AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PUEBLO CO 550 PM MDT FRI MAY 2 2008 .UPDATE... BASED ON THE 13K RUC MODEL...IT APPEARS THE THREAT FOR WIDESPREAD DAMAGING WINDS WILL BE DIMINISHING ACROSS SOUTHEAST CO THIS EVENING. THERE STILL COULD BE A BRIEF GUST AROUND 55 MPH ACROSS THE FAR SOUTHEAST CO PLAINS...BUT WILL HANDLE THIS IN THE DIGITAL FORECAST AND HAZARDOUS WEATHER OUTLOOK. METZE && .PREV DISCUSSION... /ISSUED 418 PM MDT FRI MAY 2 2008/ UPDATE... A QUICK BOOKKEEPING UPDATE TO REMOVE THE SNOW AND BLOWING SNOW ADVISORY. 17 PREV DISCUSSION... /ISSUED 307 PM MDT FRI MAY 2 2008/ SHORT TERM... (TONIGHT AND TOMORROW) .WINDS DECREASING...COLD TONIGHT.... CURRENTLY...MAJOR LATE SEASON CYCLONE BRINGING MAINLY WIND TO OUR PLAINS AND SOME SNOWS TO THE CENTRAL MOUNTAINS. AS OF 2 PM TODAY WINDS OVER SE CO PLAINS HAVE BEEN IN THE 40 TO 50 MPH RANGE...WITH MUCH STRONGER GUSTS TO THE N AND E OF THE REGION. SNOW WAS ALSO CONTINUING IN THE C MTNS ACCORDING TO ASOS REPORTS. FOR THIS AFTERNOON...WINDS ARE FCST TO GRADUALLY DECREASE BY LATER THIS AFTERNOON AS PRES GRAD DECREASES AS SFC CYCLONE GRADUALLY MOVES TO THE EAST AWAY FROM THE REGION. SKIES WILL GENERALLY BE PARTLY TO MOSTLY CLOUDY AND WE MAY SEE SOME SHOWERS N OF HIGHWAY 50 ON THE PLAINS. RUC IS ALSO HINTING AT SOME PRECIP ON THE RATON MESA DOWN NEAR KTAD. ANY PRECIP ON THE PLAINS SHOULD BE LIGHT WITH VIS REMAINING ABOVE 3SM IN -SN. FOR TONIGHT...MAIN CONCERN IS COLD. ALL GUIDANCE IS INDICATING TEMPS BELOW FREEZING WITH THE COLDEST AIR ALONG THE I-25 CORRIDOR. THIS LOOKS QUITE REASONABLE AS WINDS SHOULD DROP DOWN PRETTY QUICKLY THIS EVENING. EXPECT TEMPS IN THE 20-28 RANGE ALONG I-25 CORRIDOR WITH 25-32 OVER FAR E PLAINS (WHERE WINDS WILL KEEP UP A BIT LONGER). TOMORROW...A QUIET DAY (FOR A CHANGE). TEMPS SHOULD RUN ABOUT 5-10F WARMER THAN TODAY AND THE WINDS WILL BE LIGHT. NO SIGNIFICANT PRECIP IS EXPECTED AS A WEAK MID LEVEL RIDGE BUILDS OVER THE REGION. /34 LONG TERM... (SATURDAY NIGHT THROUGH FRIDAY) C51ENGE IN THE LONG TERM IS WHEN UPPER LOW EJECTS FROM THE SOUTHWEST US. SATURDAY NIGHT THROUGH MONDAY...MODELS SHOW THAT UPPER RIDGE CENTERED TO OUR SOUTH WILL INFLUENCE SENSIBLE WEATHER. AFTER LOWS IN THE UPPER TEENS TO MID 30S ACROSS THE AREA...TEMPERATURES WILL RISE INTO THE 70S ACROSS MUCH OF THE PLAINS...WITH MID LEVEL TEMPERATURES REACHING VALUES AROUND 8 DEGREES CELSIUS. HIGHS WILL RANGE FROM THE 30S IN THE NORTH CENTRAL MOUNTAINS TO THE 60S IN THE SAN LUIS VALLEY. WITH LIMITED MOISTURE ONLY SLIGHT CHANCES FOR SHOWERS OR THUNDERSTORMS DURING SUNDAY AFTERNOON AND NIGHT...MAINLY ACROSS THE HIGHER TERRAIN AND FAR SOUTHEAST. NAM12 HINTS THAT THE MOISTURE ACROSS EASTERN NEW MEXICO AND THE TEXAS PANHANDLE MAY GET SHUNTED NORTH BY LOW LEVEL JET INTO BACA AND PROWERS COUNTIES LATE AFTERNOON AND THROUGH THE NIGHT. PUT HIGHEST POPS IN THAT AREA...ALONG WITH THUNDER. ON MONDAY...RIDGE WILL PROVIDE MAINLY DRY WEATHER...WITH SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. MID LEVEL TEMPERATURES A DEGREE OR TWO HIGHER THAN SUNDAY...SO HIGHS SHOULD REACH THE 70S TO AROUND 80 IN THE PLAINS...AND 40S TO LOWER 70S ACROSS THE MOUNTAINS AND HIGH VALLEYS. TUESDAY THROUGH WEDNESDAY...THE EJECTION OF UPPER LOW IN THE SOUTHWEST US IS RESOLVED DIFFERENTLY BY GFS AND EUROPEAN MODELS. EUROPEAN WANTS TO BRING IN THE LOW...ALONG WITH MOISTURE AND CHANCES FOR SHOWERS ABOUT 12 HOURS FASTER THAN THE GFS. SINCE THIS IS SEVERAL DAYS AWAY...AND THE LOW IS NOW HUNDREDS OF MILES WEST OF SAN FRANCISCO MOVING SOUTH...TIMING IS ANYTHING BUT CERTAIN. FORECAST GRIDS FOR PUB AND SURROUNDING OFFICES HAVE GENERAL BROAD BRUSH SLIGHT CHANCE TO LOW CHANCE POPS THROUGH THE PERIOD...WITH TEMPERATURES LOWERING ON WEDNESDAY WITH MORE CLOUDS AND COOLING MID LEVEL TEMPERATURES BY SOME 3 DEGREES CELSIUS. THURSDAY AND FRIDAY...NEXT UPPER WAVE ALSO IS HANDLED DIFFERENTLY BY GFS AND EUROPEAN MODELS. GFS DEVELOPS A CUTOFF LOW OVER NORTHERN ROCKIES...WHILE EUROPEAN HAS A PROGRESSIVE WAVE WHICH ARRIVES BY FRIDAY. MUCH UNCERTAINTY WITH SOLUTIONS. PUB AND SURROUNDING OFFICES ARE GOING WITH DRIER...MILDER SOLUTION OF GFS ATTM. STAY TUNED. -TLM- AVIATION...WINDS WILL DIE DOWN LATE THIS AFTERNOON AND EARLY EVENING. OTHERWISE EXPECT VFR CONDITIONS AT ALL TAF SITES. && .PUB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM MDT SATURDAY FOR COZ083>089-093>099. && $$ 17/17 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 418 PM MDT FRI MAY 2 2008 .UPDATE... A QUICK BOOKKEEPING UPDATE TO REMOVE THE SNOW AND BLOWING SNOW ADVISORY. METZE && .PREV DISCUSSION... /ISSUED 307 PM MDT FRI MAY 2 2008/ SHORT TERM... (TONIGHT AND TOMORROW) ..WINDS DECREASING...COLD TONIGHT.... CURRENTLY...MAJOR LATE SEASON CYCLONE BRINGING MAINLY WIND TO OUR PLAINS AND SOME SNOWS TO THE CENTRAL MOUNTAINS. AS OF 2 PM TODAY WINDS OVER SE CO PLAINS HAVE BEEN IN THE 40 TO 50 MPH RANGE...WITH MUCH STRONGER GUSTS TO THE N AND E OF THE REGION. SNOW WAS ALSO CONTINUING IN THE C MTNS ACCORDING TO ASOS REPORTS. FOR THIS AFTERNOON...WINDS ARE FCST TO GRADUALLY DECREASE BY LATER THIS AFTERNOON AS PRES GRAD DECREASES AS SFC CYCLONE GRADUALLY MOVES TO THE EAST AWAY FROM THE REGION. SKIES WILL GENERALLY BE PARTLY TO MOSTLY CLOUDY AND WE MAY SEE SOME SHOWERS N OF HIGHWAY 50 ON THE PLAINS. RUC IS ALSO HINTING AT SOME PRECIP ON THE RATON MESA DOWN NEAR KTAD. ANY PRECIP ON THE PLAINS SHOULD BE LIGHT WITH VIS REMAINING ABOVE 3SM IN -SN. FOR TONIGHT...MAIN CONCERN IS COLD. ALL GUIDANCE IS INDICATING TEMPS BELOW FREEZING WITH THE COLDEST AIR ALONG THE I-25 CORRIDOR. THIS LOOKS QUITE REASONABLE AS WINDS SHOULD DROP DOWN PRETTY QUICKLY THIS EVENING. EXPECT TEMPS IN THE 20-28 RANGE ALONG I-25 CORRIDOR WITH 25-32 OVER FAR E PLAINS (WHERE WINDS WILL KEEP UP A BIT LONGER). TOMORROW...A QUIET DAY (FOR A CHANGE). TEMPS SHOULD RUN ABOUT 5-10F WARMER THAN TODAY AND THE WINDS WILL BE LIGHT. NO SIGNIFICANT PRECIP IS EXPECTED AS A WEAK MID LEVEL RIDGE BUILDS OVER THE REGION. /34 LONG TERM... (SATURDAY NIGHT THROUGH FRIDAY) C51ENGE IN THE LONG TERM IS WHEN UPPER LOW EJECTS FROM THE SOUTHWEST US. SATURDAY NIGHT THROUGH MONDAY...MODELS SHOW THAT UPPER RIDGE CENTERED TO OUR SOUTH WILL INFLUENCE SENSIBLE WEATHER. AFTER LOWS IN THE UPPER TEENS TO MID 30S ACROSS THE AREA...TEMPERATURES WILL RISE INTO THE 70S ACROSS MUCH OF THE PLAINS...WITH MID LEVEL TEMPERATURES REACHING VALUES AROUND 8 DEGREES CELSIUS. HIGHS WILL RANGE FROM THE 30S IN THE NORTH CENTRAL MOUNTAINS TO THE 60S IN THE SAN LUIS VALLEY. WITH LIMITED MOISTURE ONLY SLIGHT CHANCES FOR SHOWERS OR THUNDERSTORMS DURING SUNDAY AFTERNOON AND NIGHT...MAINLY ACROSS THE HIGHER TERRAIN AND FAR SOUTHEAST. NAM12 HINTS THAT THE MOISTURE ACROSS EASTERN NEW MEXICO AND THE TEXAS PANHANDLE MAY GET SHUNTED NORTH BY LOW LEVEL JET INTO BACA AND PROWERS COUNTIES LATE AFTERNOON AND THROUGH THE NIGHT. PUT HIGHEST POPS IN THAT AREA...ALONG WITH THUNDER. ON MONDAY...RIDGE WILL PROVIDE MAINLY DRY WEATHER...WITH SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. MID LEVEL TEMPERATURES A DEGREE OR TWO HIGHER THAN SUNDAY...SO HIGHS SHOULD REACH THE 70S TO AROUND 80 IN THE PLAINS...AND 40S TO LOWER 70S ACROSS THE MOUNTAINS AND HIGH VALLEYS. TUESDAY THROUGH WEDNESDAY...THE EJECTION OF UPPER LOW IN THE SOUTHWEST US IS RESOLVED DIFFERENTLY BY GFS AND EUROPEAN MODELS. EUROPEAN WANTS TO BRING IN THE LOW...ALONG WITH MOISTURE AND CHANCES FOR SHOWERS ABOUT 12 HOURS FASTER THAN THE GFS. SINCE THIS IS SEVERAL DAYS AWAY...AND THE LOW IS NOW HUNDREDS OF MILES WEST OF SAN FRANCISCO MOVING SOUTH...TIMING IS ANYTHING BUT CERTAIN. FORECAST GRIDS FOR PUB AND SURROUNDING OFFICES HAVE GENERAL BROAD BRUSH SLIGHT CHANCE TO LOW CHANCE POPS THROUGH THE PERIOD...WITH TEMPERATURES LOWERING ON WEDNESDAY WITH MORE CLOUDS AND COOLING MID LEVEL TEMPERATURES BY SOME 3 DEGREES CELSIUS. THURSDAY AND FRIDAY...NEXT UPPER WAVE ALSO IS HANDLED DIFFERENTLY BY GFS AND EUROPEAN MODELS. GFS DEVELOPS A CUTOFF LOW OVER NORTHERN ROCKIES...WHILE EUROPEAN HAS A PROGRESSIVE WAVE WHICH ARRIVES BY FRIDAY. MUCH UNCERTAINTY WITH SOLUTIONS. PUB AND SURROUNDING OFFICES ARE GOING WITH DRIER...MILDER SOLUTION OF GFS ATTM. STAY TUNED. -TLM- AVIATION...WINDS WILL DIE DOWN LATE THIS AFTERNOON AND EARLY EVENING. OTHERWISE EXPECT VFR CONDITIONS AT ALL TAF SITES. && .PUB WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 6 PM MDT THIS AFTERNOON FOR COZ084-085- 089-093-095>098. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM MDT SATURDAY FOR COZ083>089-093>099. && $$ 17/17 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 307 PM MDT FRI MAY 2 2008 .SHORT TERM... (TONIGHT AND TOMORROW) ...WINDS DECREASING...COLD TONIGHT.... CURRENTLY...MAJOR LATE SEASON CYCLONE BRINGING MAINLY WIND TO OUR PLAINS AND SOME SNOWS TO THE CENTRAL MOUNTAINS. AS OF 2 PM TODAY WINDS OVER SE CO PLAINS HAVE BEEN IN THE 40 TO 50 MPH RANGE...WITH MUCH STRONGER GUSTS TO THE N AND E OF THE REGION. SNOW WAS ALSO CONTINUING IN THE C MTNS ACCORDING TO ASOS REPORTS. FOR THIS AFTERNOON...WINDS ARE FCST TO GRADUALLY DECREASE BY LATER THIS AFTERNOON AS PRES GRAD DECREASES AS SFC CYCLONE GRADUALLY MOVES TO THE EAST AWAY FROM THE REGION. SKIES WILL GENERALLY BE PARTLY TO MOSTLY CLOUDY AND WE MAY SEE SOME SHOWERS N OF HIGHWAY 50 ON THE PLAINS. RUC IS ALSO HINTING AT SOME PRECIP ON THE RATON MESA DOWN NEAR KTAD. ANY PRECIP ON THE PLAINS SHOULD BE LIGHT WITH VIS REMAINING ABOVE 3SM IN -SN. FOR TONIGHT...MAIN CONCERN IS COLD. ALL GUIDANCE IS INDICATING TEMPS BELOW FREEZING WITH THE COLDEST AIR ALONG THE I-25 CORRIDOR. THIS LOOKS QUITE REASONABLE AS WINDS SHOULD DROP DOWN PRETTY QUICKLY THIS EVENING. EXPECT TEMPS IN THE 20-28 RANGE ALONG I-25 CORRIDOR WITH 25-32 OVER FAR E PLAINS (WHERE WINDS WILL KEEP UP A BIT LONGER). TOMORROW...A QUIET DAY (FOR A CHANGE). TEMPS SHOULD RUN ABOUT 5-10F WARMER THAN TODAY AND THE WINDS WILL BE LIGHT. NO SIGNIFICANT PRECIP IS EXPECTED AS A WEAK MID LEVEL RIDGE BUILDS OVER THE REGION. /HODANISH .LONG TERM... (SATURDAY NIGHT THROUGH FRIDAY) CHALLENGE IN THE LONG TERM IS WHEN UPPER LOW EJECTS FROM THE SOUTHWEST US. SATURDAY NIGHT THROUGH MONDAY...MODELS SHOW THAT UPPER RIDGE CENTERED TO OUR SOUTH WILL INFLUENCE SENSIBLE WEATHER. AFTER LOWS IN THE UPPER TEENS TO MID 30S ACROSS THE AREA...TEMPERATURES WILL RISE INTO THE 70S ACROSS MUCH OF THE PLAINS...WITH MID LEVEL TEMPERATURES REACHING VALUES AROUND 8 DEGREES CELSIUS. HIGHS WILL RANGE FROM THE 30S IN THE NORTH CENTRAL MOUNTAINS TO THE 60S IN THE SAN LUIS VALLEY. WITH LIMITED MOISTURE ONLY SLIGHT CHANCES FOR SHOWERS OR THUNDERSTORMS DURING SUNDAY AFTERNOON AND NIGHT...MAINLY ACROSS THE HIGHER TERRAIN AND FAR SOUTHEAST. NAM12 HINTS THAT THE MOISTURE ACROSS EASTERN NEW MEXICO AND THE TEXAS PANHANDLE MAY GET SHUNTED NORTH BY LOW LEVEL JET INTO BACA AND PROWERS COUNTIES LATE AFTERNOON AND THROUGH THE NIGHT. PUT HIGHEST POPS IN THAT AREA...ALONG WITH THUNDER. ON MONDAY...RIDGE WILL PROVIDE MAINLY DRY WEATHER...WITH SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. MID LEVEL TEMPERATURES A DEGREE OR TWO HIGHER THAN SUNDAY...SO HIGHS SHOULD REACH THE 70S TO AROUND 80 IN THE PLAINS...AND 40S TO LOWER 70S ACROSS THE MOUNTAINS AND HIGH VALLEYS. TUESDAY THROUGH WEDNESDAY...THE EJECTION OF UPPER LOW IN THE SOUTHWEST US IS RESOLVED DIFFERENTLY BY GFS AND EUROPEAN MODELS. EUROPEAN WANTS TO BRING IN THE LOW...ALONG WITH MOISTURE AND CHANCES FOR SHOWERS ABOUT 12 HOURS FASTER THAN THE GFS. SINCE THIS IS SEVERAL DAYS AWAY...AND THE LOW IS NOW HUNDREDS OF MILES WEST OF SAN FRANCISCO MOVING SOUTH...TIMING IS ANYTHING BUT CERTAIN. FORECAST GRIDS FOR PUB AND SURROUNDING OFFICES HAVE GENERAL BROAD BRUSH SLIGHT CHANCE TO LOW CHANCE POPS THROUGH THE PERIOD...WITH TEMPERATURES LOWERING ON WEDNESDAY WITH MORE CLOUDS AND COOLING MID LEVEL TEMPERATURES BY SOME 3 DEGREES CELSIUS. THURSDAY AND FRIDAY...NEXT UPPER WAVE ALSO IS HANDLED DIFFERENTLY BY GFS AND EUROPEAN MODELS. GFS DEVELOPS A CUTOFF LOW OVER NORTHERN ROCKIES...WHILE EUROPEAN HAS A PROGRESSIVE WAVE WHICH ARRIVES BY FRIDAY. MUCH UNCERTAINTY WITH SOLUTIONS. PUB AND SURROUNDING OFFICES ARE GOING WITH DRIER...MILDER SOLUTION OF GFS ATTM. STAY TUNED. -TLM- && .AVIATION...WINDS WILL DIE DOWN LATE THIS AFTERNOON AND EARLY EVENING. OTHERWISE EXPECT VFR CONDITIONS AT ALL TAF SITES. && .PUB WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 6 PM MDT THIS AFTERNOON FOR COZ084-085- 089-093-095>098. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM MDT SATURDAY FOR COZ083>089-093>099. SNOW AND BLOWING SNOW ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR COZ058-060. && $$ 34/13 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 427 PM EDT FRI MAY 2 2008 .SYNOPSIS... A WARM FRONT WILL REMAIN S OF NEW ENGLAND INTO SAT AS A COOL ONSHORE FLOW PREVAILS ACROSS THE REGION. LOW PRES WILL PASS TO OUR S SUN INTO MON PROVIDING A BETTER CHANCE OF SHOWERS. UNSETTLED WEATHER MAY RETURN BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL MIDNIGHT TONIGHT/... FOCUS OF SHOWERS THROUGH THIS EVENING WILL BE ACROSS INTERIOR... ESPECIALLY ACROSS SW NH AND NW MA WHERE REMNANT SHOWERS ARE HEADING IN FROM EASTERN NY AND SOUTHERN VT. RUC CAPTURES THIS TREND NICELY AND WE WILL HAVE HIGHER POPS IN THESE AREAS THROUGH EARLY EVENING. OTHERWISE...PATCHY DRIZZLE AND FOG WILL PREVAIL FROM LOWER CT VALLEY INTO RI AND SE MA DUE TO PERSISTENT ONSHORE FLOW. SOUNDINGS INDICATE ENOUGH DRIER AIR WORKING IN ALOFT ACROSS EASTERN MA TO PRECLUDE DRIZZLE AND FOG THERE DESPITE LIGHT E/NE FLOW. FRONTAL BOUNDARY HAS ALREADY SAGGED S OF NEW ENGLAND AS OF MID AFTERNOON AND WILL REMAIN WELL TO OUR S TONIGHT. THIS WILL ALLOW SURFACE RIDGE TO NOSE IN FROM NH/ME LATER THIS EVENING AND PUSH FOCUS OF SHOWER ACTIVITY FARTHER W OUT OF NEW ENGLAND. && .SHORT TERM /MIDNIGHT TONIGHT THROUGH SATURDAY NIGHT/... CLOUDY SKIES EXPECTED OVERNIGHT THROUGH SAT AS CONTINUED ONSHORE FLOW MAINTAINS SUFFICIENT LOW LEVEL MOISTURE. WE PREFER 12Z GFS DEPICTION OF KEEPING MOST OF SHOWER ACTIVITY W OF NEW ENGLAND SAT...AS SURFACE RIDGE CONTINUES TO INFLUENCE OUR AREA. WE CANNOT TOTALLY RULE OUT A DRY DAY HOWEVER...ESPECIALLY NEAR CT RIVER VALLEY SO CHANCE POPS WERE LIMITED TO OUR WESTERN ZONES. POSITION OF UPPER RIDGE OVER NEW ENGLAND FAVORS KEEPING MOST IF NOT ALL OF MEASURABLE RAINFALL TO OUR W. RIDGE FINALLY MOVES E SAT NIGHT WHICH WILL ALLOW SHOWERS TO SPREAD INTO SOUTHERN NEW ENGLAND...ESPECIALLY LATER AT NIGHT AS FRONT HEADS E FROM NY STATE. STAYED CLOSE TO GMOS FOR TEMPERATURES THROUGH PERIOD GIVEN CLOUD COVER AND LIGHT ONSHORE FLOW. && .LONG TERM /SUNDAY THROUGH FRIDAY/... SUNDAY...A COLD FRONT WILL PUSH ACROSS THE FORECAST AREA WITH A WEAK SECONDARY LOW AND WARM FRONT LOCATED SOUTH OF THE REGION. THERE IS A DECENT 30-35KT SOUTHERLY LOW LEVEL JET WHICH WILL AID IN ENHANCING LOW LEVEL CONVERGENCE. IN ADDITION PRECIPITABLE WATER VALUES WILL RISE NEAR 1.4 G/KG. DECENT THETA-E ADVECTION ALSO NOTED AT THE 850 MB LEVEL WITH A SERIES OF WEAK H5 SHORT WAVES IN DEVELOPING CYCLONIC FLOW. THERE ARE SOME MINOR TIMING DIFFERENCES BETWEEN THE OPERATIONAL GFS...UKMET AND NAM...BUT OVERALL DECENT MODEL AGREEMENT ON SUNDAY. GIVEN FORCING MECHANISMS DECIDED TO BOOST POPS TO CATEGORICAL. RAIN MAY BE BRIEFLY HEAVY. INSTABILITY PARAMETERS CURRENTLY MARGINAL FOR THUNDER...BUT AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT. SUNDAY NIGHT AND MONDAY...THE COLD FRONT IS EXPECTED TO STALL JUST OFFSHORE AS THE GREAT LAKES UPPER LEVEL LOW IS FORCED TO CLIMB OVER THE UPPER LEVEL RIDGE LOCATED JUST EAST OF THE REGION. BELIEVE CLOUDS WILL LINGER ESPECIALLY ALONG THE COAST MONDAY GIVEN LACK OF SUBSIDENCE BEHIND THE FRONT...FAIRLY HIGH LOW LEVEL RELATIVE HUMIDITY AND LOW LEVEL BOUNDARY LAYER PERSISTING FLOW FROM THE NORTH NORTHEAST. SHOWERS ARE EXPECTED TO PUSH OFFSHORE SUNDAY NIGHT BUT SOME DRIZZLE COULD PERSIST THROUGH MONDAY MORNING. TUESDAY THROUGH WEDNESDAY...APPEARS THE REGION WILL BE LOCATED WITHIN A `COL" AREA. THE DURATION OF CLEARING SHOULD BE BRIEF...GIVEN VERY WEAK RIDGING ALOFT AND LIGHT WINDS. TEMPERATURES SHOULD REMAIN AT OR NEAR SEASONAL NORMS WITH DRY CONDITIONS EXPECTED. THURSDAY...NEXT LOW QUICKLY APPROACHES FROM THE GREAT LAKES...WITH A SECONDARY LOW FORMING SOUTH OF THE REGION. THE 12Z ECMWF DOES NOT DEVELOP THE SECONDARY LOW...BUT IT DOES SWING A COLD FRONT ACROSS THE FORECAST AREA. THEREFORE CONTINUED CHANCE POPS FOR THURSDAY. FRIDAY...SURFACE HIGH PRESSURE MAY BUILD BEHIND THE COLD FRONT TO BRING DRY CONDITIONS AND SEASONABLY COOL TEMPERATURES. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... 18Z TAFS FEATURE LITTLE CHANGE THROUGH PERIOD AS LOW CLOUDS REMAIN LOCKED IN THROUGH MIDDAY SAT. KBOS EXPECTED TO REMAIN ON LOWER END OF VFR /3-4KFT/ WITH PERSISTENT 09010KT WIND THROUGH PERIOD. LOW PROBABILITY OF CEILINGS TEMPORARILY LOWERING TO NEAR 1KFT 20-24Z...BUT NOT ENOUGH FOR INCLUSION INTO TAF. OTHERWISE MVFR CEILINGS WITH AREAS OF IFR WILL PERSIST INTO THIS EVENING BEFORE SOME IMPROVEMENT OCCURS AFTER MIDNIGHT...BUT CEILINGS SHOULD REMAIN MVFR MOST OF NIGHT. LOW END VFR CEILINGS EXPECTED SAT. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUNDAY...IFR CEILINGS IN SHOWERS...FOG PATCHES. RAIN COULD BE LOCALLY HEAVY. SUNDAY NIGHT...IFR CONDITIONS IN FOG PATCHES AND DRIZZLE. RAIN TAPERS OFF. SOME IMPROVEMENT POSSIBLE WESTERN TERMINALS. MONDAY...MORNING IFR CEILINGS AND VSBYS IN FOG PATCHES MAY IMPROVE EASTERN TERMINALS. IMPROVEMENT TO VFR WESTERN TERMINALS. TUESDAY AND WEDNESDAY...VFR. && .MARINE... SCA FOR SEAS BEING POSTED FOR OUTER S COASTAL WATERS THIS EVENING INTO SAT...THOUGH FOCUS OF 5 TO 6 FT SEAS WILL BE CLOSER TO E END OF LONG ISLAND AND BLOCK ISLAND AS OPPOSED TO NANTUCKET. E/NE WINDS SHOULD STAY JUST BELOW 25KT TONIGHT INTO SAT...BUT PERSISTENT FLOW WILL EASILY BE ABLE TO BUILD SEAS. WE NOTED 5 FT SEAS ALREADY BEING OBSERVED AT BUOY 44025. PERSISTENT E FLOW SAT WITH SLOWLY BUILDING SEAS. SEAS MAY REACH 5 FT SAT NIGHT ON REMAINDER OF OUTER COASTAL WATERS. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUNDAY...SCA SEAS LIKELY ACROSS THE OUTER WATERS. MONDAY THROUGH WEDNESDAY...SEAS GRADUALLY DECREASE. THURSDAY...NE WIND GUSTS TO 25 KT POSSIBLE. CONTINUED E SWELL UP TO 6 FT POSSIBLE. && .HYDROLOGY... MINOR FLOODING CONTINUES ALONG MAINSTEM CT RIVER FROM HARTFORD THROUGH MIDDLETOWN. LATEST NERFC GUIDANCE BRINGS HARTFORD BELOW FLOOD STAGE BY MIDNIGHT...BUT NOT AT MIDDLETOWN UNTIL EARLY SUN MORNING. PERIODS OF LIGHT RAIN INTO TONIGHT WILL NOT IMPACT RIVER LEVELS. REFER TO THE LATEST FLOOD STATEMENT FOR FURTHER DETAILS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 7 PM THIS EVENING TO 6 PM EDT SATURDAY FOR ANZ255. && $$ SYNOPSIS...JWD NEAR TERM...JWD SHORT TERM...JWD LONG TERM...STRAUSS AVIATION...STRAUSS/JWD MARINE...STRAUSS/JWD HYDROLOGY...JWD ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 124 PM EDT FRI MAY 2 2008 .SYNOPSIS... A WARM FRONT ACROSS SOUTHERN NEW ENGLAND WILL SLIDE JUST S OF LONG ISLAND FRI INTO THE WEEKEND WITH PERIODS OF RAIN THREATENING OUR REGION. WEAK LOW PRES LODGES IN OR NEAR NEW ENGLAND SUN NIGHT THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 4 PM THIS AFTERNOON/... OVERRUNNING SHOWERS ARE DECREASING IN COVERAGE/INTENSITY AS BEST FGEN/ISENTROPIC LIFT WEAKENS. UPDATED POPS IN THE GRIDS TO REFLECT CURRENT RADAR TRENDS WITH NAM/RUC NEAR TERM FCST. SFC BOUNDARY ACTUALLY MOVES BACK TO THE SW TODAY AS SFC RIDGING NOSES IN FROM THE NE. CLEAR SKIES NOT THAT FAR AWAY IN CENTRAL NH AND S ME BUT RH CROSS SECTIONS DO NOT BRING THIS DRIER AIR INTO OUR FA SO EXPECT MAINLY CLOUDY SKIES TO PERSIST. STILL LOTS OF MOISTURE AROUND...ESPECIALLY CENTRAL AND WEST ZONES SO LOW PROB OF SHOWERS WILL CONTINUE REST OF TODAY ALONG WITH PATCHY DRIZLLE. ANY CONVECTION THIS AFTERNOON SHOULD REMAIN SOUTH AND WEST OF SNE BASED ON CONVECTIVE INDICES. WE FOLLOWED GFS LAMP GUIDANCE FOR TEMPS WHICH SEEMS TO BE HANDLING COOL MARITIME AIRMASS. A CHILLY DAY UNDER GENERALLY OVC SKIES AND ELY MARITIME FLOW...WITH TEMPS ONLY IN THE UPPER 40S TO LOWER 50S. && .SHORT TERM /4 PM THIS AFTERNOON THROUGH 6 PM SATURDAY/... TEMPS FOR TONIGHT WERE 00Z/2 GFS MAVMOS AND SIMILAR TO THE 4PM THURSDAY FCST FOR TONIGHT. SATURDAY...INTEROFFICE CONSENSUS THAT THIS IS THE DRIEST OF THE WEEKEND DAYS DUE TO RDG ALOFT. MAINTAINED CONTINUITY WITH THE 4PM THURSDAY FCST. WHAT I DONT LIKE ABOUT THIS PATTERN INSISTING DRY IS THAT THE GFS KEEPS PACKING MOISTURE UP AGAINST THE SW PART OF OUR CWA WITH SOME INDICATION WEAK DIFFERENTIAL WAA AND POSSIBILITIES OF MID LVL SHOWERS. I CAN SEE SCT SHOWERS OCCURRING ON THE LEADING EDGE OF THE PWAT AXIS WITH 850 WINDS SWLY BENEATH NWLY MID LVL FLOW. FOR NOW...ACCEPTED LOWER POPS AND INTEROFFICE CONSENSUS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... SATURDAY NIGHT...COOL HIGH PRESSURE MOVES JUST EAST OF SOUTHERN NEW ENGLAND...POSSIBLY ALLOWING A FEW SHOWERS OVERNIGHT. THEN SUNDAY A COLD FRONT WILL MOVE ACROSS THE AREA PRODUCING SHOWERS. WHILE THERE REMAINS SOME DISCREPANCY AS TO THE TIMING OF THE COLD FRONT...ALL THE MODELS INDICATE THAT IT WILL MOVE ACROSS SOUTHERN NEW ENGLAND SOMETIME ON SUNDAY. MONDAY THROUGH TUESDAY...THE MODELS DISAGREE ON THE PROGRESSION OF THE FRONT. FOR NOW...THIS WILL HAVE LITTLE EFFECT ON THE FORECAST. THERE COULD BE PRECIP LINGERING INTO MONDAY...OR MONDAY COULD BE DRY AND THE PRECIP RETURN ON TUESDAY. WILL GO WITH LOW END CHANCE POPS FOR THESE PERIODS TO COVER UNCERTAINTY. WEDNESDAY LOOKS TO BE MOSTLY DRY AT THIS POINT NO MATTER WHICH MODEL YOU LOOK AT. THE GFS DOES MOVE PRECIP IN WEDNESDAY EVENING IN RESPONSE TO A SURFACE LOW THAT MOVES EAST ACROSS PENNSYLVANIA. THIS LOW MOVES OUT TO THE ATLANTIC SOUTH OF LONG ISLAND AND MOVES UP SOUTHEAST OF NANTUCKET AND INTO THE GULF OF MAINE THURSDAY INTO FRIDAY. IF THIS SOLUTION IS CORRECT...PRECIP WILL CONTINUE INTO THURSDAY. THE ECMWF IS ALSO PRODUCING PRECIP THURSDAY WITH A POSSIBLE COLD FRONT. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... 18Z TAFS FEATURE LITTLE CHANGE THROUGH PERIOD AS LOW CLOUDS REMAIN LOCKED IN THROUGH MIDDAY SAT. KBOS EXPECTED TO REMAIN ON LOWER END OF VFR /3-4KFT/ WITH PERSISTENT 09010KT WIND THROUGH PERIOD. LOW PROBABILITY OF CEILINGS TEMPORARILY LOWERING TO NEAR 1KFT 20-24Z...BUT NOT ENOUGH FOR INCLUSION INTO TAF. OTHERWISE MVFR CEILINGS WITH AREAS OF IFR WILL PERSIST INTO THIS EVENING BEFORE SOME IMPROVEMENT OCCURS AFTER MIDNIGHT...BUT CEILINGS SHOULD REMAIN MVFR MOST OF NIGHT. LOW END VFR CEILINGS EXPECTED SAT. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... SATURDAY NIGHT...VFR. SUNDAY...VFR DIMINISHING TO MVFR THEN IFR FROM WEST TO EAST IN SHOWERS AND LOWERING CEILINGS. SUNDAY NIGHT INTO MONDAY...MVFR/IFR CONDITIONS IMPROVING TO VFR GRADUALLY. TUESDAY AND WEDNESDAY...VFR. && .MARINE... NO HEADLINES ATTM THROUGH SATURDAY. THERE MAY BE NEED FOR AN SCA IN BID VCNTY THIS AFTN AND TONIGHT BUT CONFIDENCE IS LOW. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... SATURDAY NIGHT AND SUNDAY...SEAS CONTINUE TO INCREASE WITH SCA SEAS POSSIBLE ACROSS THE OUTER WATERS. MONDAY THROUGH WEDNESDAY...SEAS GRADUALLY DECREASE. && .HYDROLOGY... MINOR FLOODING CONTINUES ALONG MAINSTEM CT RIVER FROM HARTFORD THROUGH MIDDLETOWN. LATEST NERFC GUIDANCE BRINGS HARTFORD BELOW FLOOD STAGE BY MIDNIGHT...BUT NOT AT MIDDLETOWN UNTIL EARLY SUN MORNING. PERIODS OF LIGHT RAIN INTO TONIGHT WILL NOT IMPACT RIVER LEVELS. REFER TO THE LATEST FLOOD STATEMENT FOR FURTHER DETAILS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...KJC/DRAG SHORT TERM...DRAG LONG TERM...RLG AVIATION...JWD MARINE...DRAG/RLG HYDROLOGY...JWD/AED ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 944 PM EDT SAT MAY 3 2008 .UPDATE... WE WERE JUST ABOUT TO SEND OUR MARINE FORECAST WHEN THE 01 UTC SURFACE OBSERVATIONS CAME IN. THE WINDS AT GULF BUOY 42039 WERE SUSTAINED OUT OF THE SOUTHEAST AT 27 KNOTS...AND THEY WERE SOUTH AT 18 KNOTS AT THE C-TOWER (WHICH IS ABOUT 100 FT ASL). CURIOUSLY...ALL BUT A FEW LIGHT SHOWERS REMAIN OVER THAT AREA SO THEY ARE NOT THUNDERSTORM WIND GUSTS. THE ONLY EXPLANATION LIES ON THE MESOSCALE...AS THERE NOW APPEARS TO BE A SMALL LOW PRESSURE/HIGH PRESSURE COUPLET IN THE NORTHEAST GULF. THESE TWO OBSERVATION POINTS ARE CURRENTLY IN A SMALL BUT TIGHT GRADIENT BETWEEN THESE FEATURES...WHICH WERE PROBABLY INDUCED BY OUTFLOW FROM EARLIER STORMS. OF COURSE NONE OF THE GLOBAL MODELS SHOW THIS FEATURE...BUT THE LATEST RUC IS BEGINNING TO. WE UPDATED OUR WINDS AND SEAS BY ASSUMING THIS FEATURE WILL BE SHORT-LIVED. WE WILL MENTION CAUTION WORDING FOR NOW...AS WE THINK THIS FEATURE WILL BE VERY SHORT-LIVED (2-3 HOURS). && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR THE FOLLOWING ZONES: BAY...CALHOUN...DIXIE...FRANKLIN... GADSDEN...GULF...HOLMES...INLAND WALTON...JACKSON... JEFFERSON...LAFAYETTE...LEON...LIBERTY...MADISON...TAYLOR... WAKULLA...WASHINGTON. GM...NONE. && $$ FOURNIER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 820 AM EDT SAT MAY 03 2008 .DISCUSSION...THE LINE OF CONVECTION OUT AHEAD OF THE NEXT COLD FRONT CONTINUES TO LOOK QUITE IMPRESSIVE THIS MORNING AS IT PUSHES RAPIDLY SOUTHEASTWARD FROM MS INTO AL. HOWEVER...AS IMPRESSIVE THIS LINE APPEARS NOW...THE BAND OF STRONG STORMS HAS NOT YET ENCOUNTERED THE DEEP LAYER RIDGING WHICH IS STILL PROTECTING THE CWA THIS MORNING...AND ALL OF THE LATEST RUNS OF THE SHORT RANGE MODELS FROM THE NAM TO THE GFS TO THE RUC...ALL INDICATE A DRAMATIC WEAKENING TREND AS THESE STORMS APPROACH OUR CWA. FURTHERMORE...THE DYNAMICAL SUPPORT FOR THE COLD FRONT AT OUR LATITUDE WILL BE DECREASING AS WELL...AS THE PRIMARY UPPER LEVEL LOW HEADS QUICKLY N-NE INTO SOUTHERN CANADA. ALSO...SFC DEWPOINTS ACROSS THE CWA ARE NOT QUITE AS FAVORABLE AS THEY ARE FURTHER OFF TO THE W...AND THEY WILL NEED TO RECOVER SIGNIFICANTLY FROM THE CURRENT MID 50S TO LOWER 60S TO SUPPORT ANY STRONG STORMS OVER OUR AREA LATER TODAY. THEREFORE... HAVE LITTLE REASON TO CHANGE THE CURRENT POP DISTRIBUTION AT THIS TIME...WHICH APPEARS TO REPRESENT THE LATEST MODEL TRENDS QUITE WELL. && .AVIATION...A LINE OF SHOWERS AND TSTMS WILL SPREAD FROM WEST TO EAST ACROSS THE REGION TODAY AHEAD OF AN APPROACHING COLD FRONT. BY AFTERNOON...SOUTHERLY WINDS WILL BECOME GUSTY...ESPECIALLY NEAR THE COAST. AT 18Z...THE LINE OF SHOWERS/TSTMS SHOULD BE JUST WEST OF THE KDHN AND KPFN TERMINALS SLOWLY PUSHING EAST. SOME OF THE STORMS OVER SE AL AND THE FLORIDA PANHANDLE MAY BECOME SEVERE. AS THIS BOUNDARY PUSHES EAST TOWARD KTLH...KABY...AND KVLD DURING THE LATE AFTERNOON/EARLY EVENING A WEAKENING TREND IS EXPECTED. LEFTOVER SHOWERS WILL BE GETTING TO THE KVLD TERMINAL 00Z-06Z. && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. GM...NONE. && $$ GOULD/BARRY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1033 PM EDT SAT MAY 3 2008 .UPDATE... UPDATED TO REMOVE POPS FOR THE REST OF TONIGHT. MAIN VORTEX LOBE AND ASSOCIATED LIFT HAS SHIFTED NE...PUTTING AN END TO THE RAIN. A FEW SPRINKLES MAY BE POSSIBLE ACROSS THE FAR EAST THROUGH LATE EVENING. OTHERWISE...LOOK FOR CLEARING SKIES THE REST OF TONIGHT. HAVE ALSO UPDATED WINDS WITH THE RUC13...WHICH BETTER CAPTURES WAINING WIND SPEEDS. ALL ELSE LOOKS GOOD. && PREV DISCUSSION... /ISSUED 744 PM EDT SAT MAY 3 2008/ AVIATION.../00Z TAFS/ AREA OF DEFORMATION PRECIP QUICKLY PUSHING EAST ACROSS PORTIONS OF THE FA. EXPECT A PERIOD OF MVFR CIGS AND SHOWERS TO CONTINUE TO TRANSLATE EAST ACROSS NORTHERN PORTIONS OF THE FA THROUGH THE EVENING. UPSTREAM SFC OBS AND SAT TRENDS CLEARLY PORTRAY THE EFFECTS OF SFC RIDGING...WITH CLOUDS QUICKLY SCT AND CLEARING OVER IL. EXPECT BOTH TERMINALS TO BE AT VFR CONDITIONS BY LATE EVENING...WITH SKC BY 09Z. GUSTY WESTERLY WINDS WILL CONTINUE TO DIMINISH THROUGH THE NIGHT AS THE PRESSURE GRADIENT RELAXES. HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE REGION SUN...WITH MOSTLY CLEAR SKIES AND LIGHT WINDS EXPECTED. PREV DISCUSSION... /ISSUED 259 PM EDT SAT MAY 3 2008/ SHORT TERM...THIS AFTERNOON THROUGH SUNDAY... SFC COLD FRONT WASHING OUT AS WE SPEAK AS SFC LOW OVER ONTARIO CONTINUES TO RAPIDLY PIVOT NWD AROUND HUDSON BAY UPPER LOW. PRE-FRONTAL TROUGH EXTENDING FROM ROUGHLY ANN ARBOR TO DEFIANCE TO MUNCIE ATTM LOOKS TO BE ONLY FORCING MECHANISM STG ENOUGH TO SUPPORT ANYTHING MORE THAN VERY LIGHT RAIN SHOWERS OR SPRINKLES THIS AFTERNOON. THIS AFTERNOON... AS SFC LOWS BOLTS NWD THROUGH ONTARIO...LOW LEVEL FORCING WILL BE TOUGH TO COME BY ALONG SFC AND H85 COLD FRONTS. DECENT COLD POOL AT H5 ALSO LOOKS TO BE QUICKLY PEELING NORTH PER RUC ANALYSIS. THEREFORE...THOUGHT IT PRUDENT TO CUT POPS EVERYWHERE LEAVING JUST A SLIGHT CHANCE OF LIGHT RAIN SHOWERS OR SPRINKLES WEST OF AFOREMENTIONED PRE-FRONTAL TROUGH. SFC DEW POINTS IN THE LOW 40S ALSO SUPPORT THIS NOTION AS DRY AIR HAS BEEN ABLE TO EASILY MIX TO SFC UNDER NEARLY FULL SUN OVER MUCH OF THE CWA TODAY. EXCEPTION TO THE LOW DEWPTS IS IN EXTREME ERN CWA WHERE LL SOUTHERLY FLOW HAS MAINTAINED MID 50S TD/S AHEAD OF TROUGH. LEFT HIGHER POPS IN ALLEN AND PUTNAM COUNTIES THIS AFTERNOON AS DECENT CONVECTIVE ENVIRONMENT WILL STILL EXIST UNTIL PRE-FRONTAL TROUGH SLIDES THROUGH. TONIGHT...CLOUDS THAT MOVE IN THIS AFTERNOON WILL QUICKLY MOVE OUT BY 6Z LEAVING CHANCE OF FROST EARLY SUN MORNING AS LOWS BOTTOM OUT IN UPPER 30S. IF PLAINS SFC HIGH SLIDES IN FAST ENOUGH TO ALLOW WINDS TO DIE...SOME MID 30S WOULD EVEN BE POSSIBLE TOWARD DAYBREAK...ESPECIALLY WESTERN CWA. SUNDAY...NICE DAY IN THE CARDS WITH TEMPS NEAR NORMAL AND MOSTLY SUNNY SKIES. A FEW CU WILL BE POSSIBLE IN THE AFTERNOON IN THE SOUTH WHERE A LITTLE MORE MOISTURE WILL BE AVAILABLE. LONG TERM... SUNDAY NIGHT THROUGH SATURDAY. HIGH PRESSURE WILL CONTROL CONDITIONS INTO TUESDAY. A COLD FRONT WILL DROP SOUTH FROM THE PLAINS AND PASS THROUGH TUESDAY NIGHT WITH A CHANCE OF SHOWERS. AFTER THIS TIME FRAME THINGS BECOME MORE UNCERTAIN IN TERMS OF WHERE FRONTAL BOUNDARY WILL LAY OUT ACROSS THE REGION WITH SEVERAL WAVES STILL PROGGED TO MOVE ALONG IT WITH COLD AIR BOTTLED UP IN CANADA AND WARM...HUMID CONDITIONS DOWN IN THE GULF STATES...AT LEAST TO START WITH. ENSEMBLES IN SPIRIT BEGINNING TO COME INTO SOME AGREEMENT COMPARED TO RECENTLY BUT STILL SOME DECENT SPREADS. MEN NUMBERS COMING BACK WITH STANDARD DEVIATIONS OF 14 TO 16 INDICATIVE OF THE POTENTIAL ISSUES. SPREADS IN POPS OF 25 TO 80 PERCENT NOTED. IN ORDER TO MATCH UP BETTER WITH COLLABORATION HAVE EXPANDED CHC POPS FOR WEDS AND WEDS EVE...THEREBY GIVING AN EXTENDED PERIOD FOR A CHANCE OF SHOWERS AND STORMS. AT THIS POINT...DON`T FEEL IT WILL BE A TOTAL WASHOUT THROUGH THE PERIOD WITH A FEW LULLS...BUT IF PATTERN DOES SETUP TIMING OF WAVES WILL BE TOO DIFFICULT AT THIS POINT TO GIVE MORE DETAIL. WITH THE BOUNDARY IN THE AREA...WE COULD BE FACING LARGE TEMP GRADIENTS THROUGH MUCH OF THE EXTENDED PERIOD UNTIL THE MAIN TROUGH STARTS TO DIG IN THE WEST AND ALLOW FOR RISING HGTS. FOR NOW HAVE KEPT THINGS IN THE 60S TO LOWER 70S WITH WARMEST AT THE BEGINNING AND END OF THE PERIOD AND SLIGHTLY COOLER MIDDLE OF THE PACKAGE WITH PRECIP CHCS AND MORE POSSIBLE CLOUD COVER. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...SIMPSON LONG TERM...FISHER UPDATE/AVIATION...CHAMBERLAIN in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 846 PM EDT SAT MAY 3 2008 .UPDATE... DEFORMATION ZONE/UPPER LEVEL TROUGH AXIS ASSOCIATED WITH THE DEPARTING LOW PRESSURE SYSTEM...IS CONTINUING TO SUPPORT WIDESPREAD LIGHT RAIN OVER PORTIONS OF NORTHERN IN AND SOUTHERN MI. FARTHER WEST...SKIES ARE QUICKLY CLEARING WITH SKC NOTED OVER MUCH OF IL AND WI PER SFC RIDGING. HAVE UPDATED TO INCREASE POPS IN THE NE...PER RADAR TRENDS AND EXPECTED MOVEMENT. QPF VALUES ARE EXPECTED TO REMAIN LOW...WITH GENERALLY NO MORE THAN 5 HUNDREDTHS EXPECTED. RAIN IS EXPECTED TO BE CLEAR OF THE FA SHORTLY AFTER MIDNIGHT. CLOUDS WILL CLEAR WEST TO EAST THROUGH THE EVENING AND EARLY MORNING. PATCHY FROST MAY STILL BE POSSIBLE IN THE WEST...WHERE TEMPS IN THE MID AND UPPER 30S AND A DIMINISHING WIND FIELD UNDER CLEAR SKIES WILL SUPPORT EXCELLENT RADIATIONAL COOLING. && .PREV DISCUSSION... /ISSUED 744 PM EDT SAT MAY 3 2008/ AVIATION.../00Z TAFS/ AREA OF DEFORMATION PRECIP QUICKLY PUSHING EAST ACROSS PORTIONS OF THE FA. EXPECT A PERIOD OF MVFR CIGS AND SHOWERS TO CONTINUE TO TRANSLATE EAST ACROSS NORTHERN PORTIONS OF THE FA THROUGH THE EVENING. UPSTREAM SFC OBS AND SAT TRENDS CLEARLY PORTRAY THE EFFECTS OF SFC RIDGING...WITH CLOUDS QUICKLY SCT AND CLEARING OVER IL. EXPECT BOTH TERMINALS TO BE AT VFR CONDITIONS BY LATE EVENING...WITH SKC BY 09Z. GUSTY WESTERLY WINDS WILL CONTINUE TO DIMINISH THROUGH THE NIGHT AS THE PRESSURE GRADIENT RELAXES. HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE REGION SUN...WITH MOSTLY CLEAR SKIES AND LIGHT WINDS EXPECTED. PREV DISCUSSION... /ISSUED 259 PM EDT SAT MAY 3 2008/ SHORT TERM...THIS AFTERNOON THROUGH SUNDAY... SFC COLD FRONT WASHING OUT AS WE SPEAK AS SFC LOW OVER ONTARIO CONTINUES TO RAPIDLY PIVOT NWD AROUND HUDSON BAY UPPER LOW. PRE-FRONTAL TROUGH EXTENDING FROM ROUGHLY ANN ARBOR TO DEFIANCE TO MUNCIE ATTM LOOKS TO BE ONLY FORCING MECHANISM STG ENOUGH TO SUPPORT ANYTHING MORE THAN VERY LIGHT RAIN SHOWERS OR SPRINKLES THIS AFTERNOON. THIS AFTERNOON... AS SFC LOWS BOLTS NWD THROUGH ONTARIO...LOW LEVEL FORCING WILL BE TOUGH TO COME BY ALONG SFC AND H85 COLD FRONTS. DECENT COLD POOL AT H5 ALSO LOOKS TO BE QUICKLY PEELING NORTH PER RUC ANALYSIS. THEREFORE...THOUGHT IT PRUDENT TO CUT POPS EVERYWHERE LEAVING JUST A SLIGHT CHANCE OF LIGHT RAIN SHOWERS OR SPRINKLES WEST OF AFOREMENTIONED PRE-FRONTAL TROUGH. SFC DEW POINTS IN THE LOW 40S ALSO SUPPORT THIS NOTION AS DRY AIR HAS BEEN ABLE TO EASILY MIX TO SFC UNDER NEARLY FULL SUN OVER MUCH OF THE CWA TODAY. EXCEPTION TO THE LOW DEWPTS IS IN EXTREME ERN CWA WHERE LL SOUTHERLY FLOW HAS MAINTAINED MID 50S TD/S AHEAD OF TROUGH. LEFT HIGHER POPS IN ALLEN AND PUTNAM COUNTIES THIS AFTERNOON AS DECENT CONVECTIVE ENVIRONMENT WILL STILL EXIST UNTIL PRE-FRONTAL TROUGH SLIDES THROUGH. TONIGHT...CLOUDS THAT MOVE IN THIS AFTERNOON WILL QUICKLY MOVE OUT BY 6Z LEAVING CHANCE OF FROST EARLY SUN MORNING AS LOWS BOTTOM OUT IN UPPER 30S. IF PLAINS SFC HIGH SLIDES IN FAST ENOUGH TO ALLOW WINDS TO DIE...SOME MID 30S WOULD EVEN BE POSSIBLE TOWARD DAYBREAK...ESPECIALLY WESTERN CWA. SUNDAY...NICE DAY IN THE CARDS WITH TEMPS NEAR NORMAL AND MOSTLY SUNNY SKIES. A FEW CU WILL BE POSSIBLE IN THE AFTERNOON IN THE SOUTH WHERE A LITTLE MORE MOISTURE WILL BE AVAILABLE. LONG TERM... SUNDAY NIGHT THROUGH SATURDAY. HIGH PRESSURE WILL CONTROL CONDITIONS INTO TUESDAY. A COLD FRONT WILL DROP SOUTH FROM THE PLAINS AND PASS THROUGH TUESDAY NIGHT WITH A CHANCE OF SHOWERS. AFTER THIS TIME FRAME THINGS BECOME MORE UNCERTAIN IN TERMS OF WHERE FRONTAL BOUNDARY WILL LAY OUT ACROSS THE REGION WITH SEVERAL WAVES STILL PROGGED TO MOVE ALONG IT WITH COLD AIR BOTTLED UP IN CANADA AND WARM...HUMID CONDITIONS DOWN IN THE GULF STATES...AT LEAST TO START WITH. ENSEMBLES IN SPIRIT BEGINNING TO COME INTO SOME AGREEMENT COMPARED TO RECENTLY BUT STILL SOME DECENT SPREADS. MEN NUMBERS COMING BACK WITH STANDARD DEVIATIONS OF 14 TO 16 INDICATIVE OF THE POTENTIAL ISSUES. SPREADS IN POPS OF 25 TO 80 PERCENT NOTED. IN ORDER TO MATCH UP BETTER WITH COLLABORATION HAVE EXPANDED CHC POPS FOR WEDS AND WEDS EVE...THEREBY GIVING AN EXTENDED PERIOD FOR A CHANCE OF SHOWERS AND STORMS. AT THIS POINT...DON`T FEEL IT WILL BE A TOTAL WASHOUT THROUGH THE PERIOD WITH A FEW LULLS...BUT IF PATTERN DOES SETUP TIMING OF WAVES WILL BE TOO DIFFICULT AT THIS POINT TO GIVE MORE DETAIL. WITH THE BOUNDARY IN THE AREA...WE COULD BE FACING LARGE TEMP GRADIENTS THROUGH MUCH OF THE EXTENDED PERIOD UNTIL THE MAIN TROUGH STARTS TO DIG IN THE WEST AND ALLOW FOR RISING HGTS. FOR NOW HAVE KEPT THINGS IN THE 60S TO LOWER 70S WITH WARMEST AT THE BEGINNING AND END OF THE PERIOD AND SLIGHTLY COOLER MIDDLE OF THE PACKAGE WITH PRECIP CHCS AND MORE POSSIBLE CLOUD COVER. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LMZ043-046. && $$ SHORT TERM...SIMPSON LONG TERM...FISHER UPDATE/AVIATION...CHAMBERLAIN in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 744 PM EDT SAT MAY 3 2008 .AVIATION.../00Z TAFS/ AREA OF DEFORMATION PRECIP QUICKLY PUSHING EAST ACROSS PORTIONS OF THE FA. EXPECT A PERIOD OF MVFR CIGS AND SHOWERS TO CONTINUE TO TRANSLATE EAST ACROSS NORTHERN PORTIONS OF THE FA THROUGH THE EVENING. UPSTREAM SFC OBS AND SAT TRENDS CLEARLY PORTRAY THE EFFECTS OF SFC RIDGING...WITH CLOUDS QUICKLY SCT AND CLEARING OVER IL. EXPECT BOTH TERMINALS TO BE AT VFR CONDITIONS BY LATE EVENING...WITH SKC BY 09Z. GUSTY WESTERLY WINDS WILL CONTINUE TO DIMINISH THROUGH THE NIGHT AS THE PRESSURE GRADIENT RELAXES. HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE REGION SUN...WITH MOSTLY CLEAR SKIES AND LIGHT WINDS EXPECTED. && .PREV DISCUSSION... /ISSUED 259 PM EDT SAT MAY 3 2008/ SHORT TERM...THIS AFTERNOON THROUGH SUNDAY... SFC COLD FRONT WASHING OUT AS WE SPEAK AS SFC LOW OVER ONTARIO CONTINUES TO RAPIDLY PIVOT NWD AROUND HUDSON BAY UPPER LOW. PRE-FRONTAL TROUGH EXTENDING FROM ROUGHLY ANN ARBOR TO DEFIANCE TO MUNCIE ATTM LOOKS TO BE ONLY FORCING MECHANISM STG ENOUGH TO SUPPORT ANYTHING MORE THAN VERY LIGHT RAIN SHOWERS OR SPRINKLES THIS AFTERNOON. THIS AFTERNOON... AS SFC LOWS BOLTS NWD THROUGH ONTARIO...LOW LEVEL FORCING WILL BE TOUGH TO COME BY ALONG SFC AND H85 COLD FRONTS. DECENT COLD POOL AT H5 ALSO LOOKS TO BE QUICKLY PEELING NORTH PER RUC ANALYSIS. THEREFORE...THOUGHT IT PRUDENT TO CUT POPS EVERYWHERE LEAVING JUST A SLIGHT CHANCE OF LIGHT RAIN SHOWERS OR SPRINKLES WEST OF AFOREMENTIONED PRE-FRONTAL TROUGH. SFC DEW POINTS IN THE LOW 40S ALSO SUPPORT THIS NOTION AS DRY AIR HAS BEEN ABLE TO EASILY MIX TO SFC UNDER NEARLY FULL SUN OVER MUCH OF THE CWA TODAY. EXCEPTION TO THE LOW DEWPTS IS IN EXTREME ERN CWA WHERE LL SOUTHERLY FLOW HAS MAINTAINED MID 50S TD/S AHEAD OF TROUGH. LEFT HIGHER POPS IN ALLEN AND PUTNAM COUNTIES THIS AFTERNOON AS DECENT CONVECTIVE ENVIRONMENT WILL STILL EXIST UNTIL PRE-FRONTAL TROUGH SLIDES THROUGH. TONIGHT...CLOUDS THAT MOVE IN THIS AFTERNOON WILL QUICKLY MOVE OUT BY 6Z LEAVING CHANCE OF FROST EARLY SUN MORNING AS LOWS BOTTOM OUT IN UPPER 30S. IF PLAINS SFC HIGH SLIDES IN FAST ENOUGH TO ALLOW WINDS TO DIE...SOME MID 30S WOULD EVEN BE POSSIBLE TOWARD DAYBREAK...ESPECIALLY WESTERN CWA. SUNDAY...NICE DAY IN THE CARDS WITH TEMPS NEAR NORMAL AND MOSTLY SUNNY SKIES. A FEW CU WILL BE POSSIBLE IN THE AFTERNOON IN THE SOUTH WHERE A LITTLE MORE MOISTURE WILL BE AVAILABLE. LONG TERM... SUNDAY NIGHT THROUGH SATURDAY. HIGH PRESSURE WILL CONTROL CONDITIONS INTO TUESDAY. A COLD FRONT WILL DROP SOUTH FROM THE PLAINS AND PASS THROUGH TUESDAY NIGHT WITH A CHANCE OF SHOWERS. AFTER THIS TIME FRAME THINGS BECOME MORE UNCERTAIN IN TERMS OF WHERE FRONTAL BOUNDARY WILL LAY OUT ACROSS THE REGION WITH SEVERAL WAVES STILL PROGGED TO MOVE ALONG IT WITH COLD AIR BOTTLED UP IN CANADA AND WARM...HUMID CONDITIONS DOWN IN THE GULF STATES...AT LEAST TO START WITH. ENSEMBLES IN SPIRIT BEGINNING TO COME INTO SOME AGREEMENT COMPARED TO RECENTLY BUT STILL SOME DECENT SPREADS. MEN NUMBERS COMING BACK WITH STANDARD DEVIATIONS OF 14 TO 16 INDICATIVE OF THE POTENTIAL ISSUES. SPREADS IN POPS OF 25 TO 80 PERCENT NOTED. IN ORDER TO MATCH UP BETTER WITH COLLABORATION HAVE EXPANDED CHC POPS FOR WEDS AND WEDS EVE...THEREBY GIVING AN EXTENDED PERIOD FOR A CHANCE OF SHOWERS AND STORMS. AT THIS POINT...DON`T FEEL IT WILL BE A TOTAL WASHOUT THROUGH THE PERIOD WITH A FEW LULLS...BUT IF PATTERN DOES SETUP TIMING OF WAVES WILL BE TOO DIFFICULT AT THIS POINT TO GIVE MORE DETAIL. WITH THE BOUNDARY IN THE AREA...WE COULD BE FACING LARGE TEMP GRADIENTS THROUGH MUCH OF THE EXTENDED PERIOD UNTIL THE MAIN TROUGH STARTS TO DIG IN THE WEST AND ALLOW FOR RISING HGTS. FOR NOW HAVE KEPT THINGS IN THE 60S TO LOWER 70S WITH WARMEST AT THE BEGINNING AND END OF THE PERIOD AND SLIGHTLY COOLER MIDDLE OF THE PACKAGE WITH PRECIP CHCS AND MORE POSSIBLE CLOUD COVER. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LMZ043-046. && $$ SHORT TERM...SIMPSON LONG TERM...FISHER AVIATION...CHAMBERLAIN in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 259 PM EDT SAT MAY 3 2008 .SHORT TERM...THIS AFTERNOON THROUGH SUNDAY... SFC COLD FRONT WASHING OUT AS WE SPEAK AS SFC LOW OVER ONTARIO CONTINUES TO RAPIDLY PIVOT NWD AROUND HUDSON BAY UPPER LOW. PRE-FRONTAL TROUGH EXTENDING FROM ROUGHLY ANN ARBOR TO DEFIANCE TO MUNCIE ATTM LOOKS TO BE ONLY FORCING MECHANISM STG ENOUGH TO SUPPORT ANYTHING MORE THAN VERY LIGHT RAIN SHOWERS OR SPRINKLES THIS AFTERNOON. THIS AFTERNOON... AS SFC LOWS BOLTS NWD THROUGH ONTARIO...LOW LEVEL FORCING WILL BE TOUGH TO COME BY ALONG SFC AND H85 COLD FRONTS. DECENT COLD POOL AT H5 ALSO LOOKS TO BE QUICKLY PEELING NORTH PER RUC ANALYSIS. THEREFORE...THOUGHT IT PRUDENT TO CUT POPS EVERYWHERE LEAVING JUST A SLIGHT CHANCE OF LIGHT RAIN SHOWERS OR SPRINKLES WEST OF AFOREMENTIONED PRE-FRONTAL TROUGH. SFC DEW POINTS IN THE LOW 40S ALSO SUPPORT THIS NOTION AS DRY AIR HAS BEEN ABLE TO EASILY MIX TO SFC UNDER NEARLY FULL SUN OVER MUCH OF THE CWA TODAY. EXCEPTION TO THE LOW DEWPTS IS IN EXTREME ERN CWA WHERE LL SOUTHERLY FLOW HAS MAINTAINED MID 50S TD/S AHEAD OF TROUGH. LEFT HIGHER POPS IN ALLEN AND PUTNAM COUNTIES THIS AFTERNOON AS DECENT CONVECTIVE ENVIRONMENT WILL STILL EXIST UNTIL PRE-FRONTAL TROUGH SLIDES THROUGH. TONIGHT...CLOUDS THAT MOVE IN THIS AFTERNOON WILL QUICKLY MOVE OUT BY 6Z LEAVING CHANCE OF FROST EARLY SUN MORNING AS LOWS BOTTOM OUT IN UPPER 30S. IF PLAINS SFC HIGH SLIDES IN FAST ENOUGH TO ALLOW WINDS TO DIE...SOME MID 30S WOULD EVEN BE POSSIBLE TOWARD DAYBREAK...ESPECIALLY WESTERN CWA. SUNDAY...NICE DAY IN THE CARDS WITH TEMPS NEAR NORMAL AND MOSTLY SUNNY SKIES. A FEW CU WILL BE POSSIBLE IN THE AFTERNOON IN THE SOUTH WHERE A LITTLE MORE MOISTURE WILL BE AVAILABLE. && .LONG TERM... SUNDAY NIGHT THROUGH SATURDAY. HIGH PRESSURE WILL CONTROL CONDITIONS INTO TUESDAY. A COLD FRONT WILL DROP SOUTH FROM THE PLAINS AND PASS THROUGH TUESDAY NIGHT WITH A CHANCE OF SHOWERS. AFTER THIS TIME FRAME THINGS BECOME MORE UNCERTAIN IN TERMS OF WHERE FRONTAL BOUNDARY WILL LAY OUT ACROSS THE REGION WITH SEVERAL WAVES STILL PROGGED TO MOVE ALONG IT WITH COLD AIR BOTTLED UP IN CANADA AND WARM...HUMID CONDITIONS DOWN IN THE GULF STATES...AT LEAST TO START WITH. ENSEMBLES IN SPIRIT BEGINNING TO COME INTO SOME AGREEMENT COMPARED TO RECENTLY BUT STILL SOME DECENT SPREADS. MEN NUMBERS COMING BACK WITH STANDARD DEVIATIONS OF 14 TO 16 INDICATIVE OF THE POTENTIAL ISSUES. SPREADS IN POPS OF 25 TO 80 PERCENT NOTED. IN ORDER TO MATCH UP BETTER WITH COLLABORATION HAVE EXPANDED CHC POPS FOR WEDS AND WEDS EVE...THEREBY GIVING AN EXTENDED PERIOD FOR A CHANCE OF SHOWERS AND STORMS. AT THIS POINT...DON`T FEEL IT WILL BE A TOTAL WASHOUT THROUGH THE PERIOD WITH A FEW LULLS...BUT IF PATTERN DOES SETUP TIMING OF WAVES WILL BE TOO DIFFICULT AT THIS POINT TO GIVE MORE DETAIL. WITH THE BOUNDARY IN THE AREA...WE COULD BE FACING LARGE TEMP GRADIENTS THROUGH MUCH OF THE EXTENDED PERIOD UNTIL THE MAIN TROUGH STARTS TO DIG IN THE WEST AND ALLOW FOR RISING HGTS. FOR NOW HAVE KEPT THINGS IN THE 60S TO LOWER 70S WITH WARMEST AT THE BEGINNING AND END OF THE PERIOD AND SLIGHTLY COOLER MIDDLE OF THE PACKAGE WITH PRECIP CHCS AND MORE POSSIBLE CLOUD COVER. && .AVIATION...DISCUSSION FOR 18Z TAFS... MVFR CONDS WILL DEVELOP EWD ALONG AND JUST BEHIND COLD FRONT OVER TAF SITES LATER THIS AFTERNOON WITH CIGS DETERIORATING TO BELOW 3KFT BY 18Z AT KSBN AND BY 19-20Z AT KFWA. SKIES THEN EXPECTED TO GO SKC BETWEEN 00-06Z TONIGHT AS DRY AIR THROUGH THE COLUMN QUICKLY WORKS IN AS SFC LOW ROTATES NWD AROUND HUDSON BAY UPPER LOW. GUSTY WSW WINDS WILL EVENTUALLY DIE DOWN TONIGHT AS PLAINS SFC RIDGING BUILDS IN AND PRES GRADIENT RELAXES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LMZ043-046. && $$ SHORT TERM...SIMPSON LONG TERM...LASHLEY AVIATION...SIMPSON in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 725 AM EDT FRI MAY 2 2008 .AVIATION/UPDATE... ELEVATED MIXED LAYER FINALLY BEGINNING TO GIVE WAY WITH INCREASE AS WEAK WAVE MOVES IN FOR THIS MORNING. EFFECTS ALREADY EVIDENT AS SHOWERS AND STORMS RAPIDLY DEVELOPING ACROSS SOUTHERN PORTIONS OF THE AREA IN THE PAST HALF HOUR. ADDITIONAL SHOWERS AND STORMS WERE DEVELOPING IN CENTRAL ILLINOIS AS WELL WITH A FEW HAIL REPORTS ALREADY NEAR OR JUST AT SEVERE LEVELS COMING OUT. BASED ON TRENDS...GREATEST CONCENTRATION OF ACTIVITY WILL BE ACROSS SE HALF OF THE CWA THROUGH 14-15Z...WITH THE ACTIVITY IN CNTRL ILLINOIS HITTING THE NW HALF (POSSIBLY MORE) AFTER 14-15Z. THEN LINE OF STORMS WILL CONTINUE TO RACE EAST NORTHEAST TOWARDS THE AREA FROM WESTERN ILLINOIS. FOR THE MOST PART THIS IS STILL SHOWING A WEAKENING TREND BUT THERE AREA A FEW BANDS OF STORMS THAT APPEAR TO BE HOLDING THEIR OWN AT THIS TIME. WILL MONITOR AS WELL. AT A MINIMUM WILL HAVE TO UPDATE GRIDS/ZONES TO GO HIGH SCT POPS IF NOT NUMEROUS SHOWERS/STORMS THROUGH AT LEAST 18Z AND SEE ABOUT EXPANDING THIS AFTERNOON. IN TERMS OF AVIATION...BASES/VSBYS ARE STILL IN THE VFR RANGE AND TAFS REFLECT THIS ALONG WITH A TEMPO TO COVER THE ACTIVITY THIS MORNING. FURTHER DETAIL WILL BE ADDED BEYOND 18Z IN LATER AMENDMENTS/FORECASTS AS SITUATION EVOLVES. && .PREV DISCUSSION... /ISSUED 404 AM EDT FRI MAY 2 2008/ SHORT TERM... CONUNDRUM THIS MORNING IS WHERE/WHEN/HOW CONV EVOLVES THROUGH TDA. SVRL POSSIBILITIES EXIST YET MOST CONVINCING NR TERM IS W/SUBTLE SW LIFTING OUT OF MO. EARLIER MID LVL RTNS ACRS WRN IL FINALLY SHOWING SOME SIGNS OF LIFE W/CONVN NOW SEEN NR EFFINGHAM IL AND ON ERN EDGE OF MID LVL HGT FALLS ASSOCD/W DEEP PLAINS TROUGH SPREADING EWD AND COLLOCATED W/SECONDARY THETA-E SURGE ADVTG NEWD OUT OF THE LWR MS VALLEY. EXTRAPOLATION PUTS THIS INTO SWRN ZONES BY 12Z ASSUMING IT MAINTAINS BUT IS REFLECTED IN 06Z RUC PROGS. HWVR EXPECTATIONS AT THIS POINT TEMPERED BY SVR EML IN PLACE AND CAPTURED WELL IN 00Z RAOBS LAST EVENING AT KILX/KSGF AND WHICH WILL BE SLOW TO ERODE THIS MORNING. OTHERWISE MOST REALISTIC MODEL SOLUTION LIES W/00Z HIGH RES NMM WHICH HAS A SUPERIOR HANDLE ON INTENSE SVR SQUALL LINE STRETCHING FM NW MO INTO N TX THIS MORNING. DOUBT THIS LINE WILL DECAY ENTIRELY GIVEN MESOSCALE DVLPMNT OF LARGE BOW HEAD AND DEEP OUTFLW BNDRY ALTHOUGH SOME WEAKENING XPCD THROUGH MID MORNING AS IT APPROACHES MS RVR VALLEY. HWVR DOWNSTREAM AIRMASS AT THAT TIME LOOKS TO DESTABILIZE ENOUGH EVEN W/DIRTY WARM SECTOR TO LEAD TO A RE-INTENSIFICATION THIS AFTN W/STILL UNCERTAIN TIMING PUTTING IT INTO NW IN TWD 21Z AND WELL INTO CWA BY 00Z W/SOME RISK FOR DAMAGING WINDS/HAIL THIS EVENING. SECONDARY CONCERNS THEN TIED TO STG CDFNT WHICH ACCELERATES EWD TONIGHT AS MID LVL TROUGH OPENS AND LOOKS TO PARTIALLY PHASE W/RETROGRADING DEEP LOW OVR SW HUDSON BAY. DEEP FORCED ASCENT ALG THE CDFNT AND SIG UPSTREAM DRY INTRUSION SHLD AIDE REDVLPMNT OF ANOTHER CONV LINE AFT MIDNIGHT WHICH WILL TRANSLATE RAPIDLY EWD. DRYSLOT OVERSPREADING AREA LATE TONIGHT SHLD PROMOTE SOME HEATING SAT MORNING W/AT LEAST LIMITED INSOLATION XPCD. THIS SHLD SETUP ANOTHER POTENTIAL LINE OF LOW TOPPED STORMS BY LATE MORNING/EARLY AFTN AS COLD CORE UPR TROUGH SWINGS THROUGH AND HOLDS AT LEAST A MARGINAL HAIL RISK AS DENOTED IN DY2 OUTLOOK ALTHOUGH TIMING SUGGEST BTR CHCS CNTRL AND EAST. WILL KEEP CLOSE TO CONTINUITY FOR TEMPS THROUGHOUT YET A BIT WARMER FOR HIGHS THIS AFTN AND SAT. LONG TERM... SUNDAY THROUGH THURSDAY...THE MAIN CHALLENGES THIS COMING WEEK INCLUDE THE POSSIBILITY OF THE SHOWERS AND THUNDERSTORMS LATE IN THE FORECAST PERIOD AS AN UPPER LEVEL SYSTEM EJECTS INTO THE AREA. BUT BEFORE THIS SYSTEM ARRIVES...A LARGE UPPER LEVEL SYSTEM WILL LIFT NORTH AWAY FROM THE REGION EARLY SUNDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST. NOT MUCH COLD AIR WILL BE ABLE TO MAKE IT INTO THE AREA AS RETURN FLOW WILL BEGIN EARLY NEXT WEEK. HOWEVER...WITH CLEAR TO PARTLY CLOUDY SKIES AND LIGHT WINDS AND A RELATIVELY DRY AIRMASS SUNDAY NIGHT...HAVE LOWERED TEMPS TO BASICALLY 37F TO 39F. THE GFS MEX OVER THE LAST 3 TO 4 DAYS APPEARS TO BE ON TRACK WITH TRENDING DOWN LOWS SUNDAY NIGHT INTO THE 30S. FROST IS STILL POSSIBLE SUNDAY NIGHT...ESPECIALLY OVER NORTHEAST AREAS. AFTER THAT...TEMPERATURES SHOULD RECOVER CLOSE TO NORMAL BY WEDNESDAY AS A WEAK UPPER LEVEL RIDGE PERSISTS OVER THE REGION. TIMING OF THE SECOND SYSTEM AND THE POSSIBILITY OF SOME WEAKER SHORTWAVES REACHING THE AREA EARLIER BEFORE THE MAIN SYSTEM ARE STILL IN QUESTION...SO WAS HESITANT TO MAKE ANY CHANGES PAST MONDAY. THE NEW 00Z ECMWF BRINGS A NEGATIVELY TILTED AND POTENT SHORTWAVE INTO THE MID MISSISSIPPI VALLEY LATE IN THE PERIOD WHICH WOULD INDICATE A VERY ACTIVE WEATHER PATTERN. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY FROM NOON TODAY TO 10 PM EDT THIS EVENING FOR LMZ043-046. && $$ UPDATE...FISHER SHORT TERM/AVIATION...HOLSTEN LONG TERM...SKIP in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 404 AM EDT FRI MAY 2 2008 .SHORT TERM... CONUNDRUM THIS MORNING IS WHERE/WHEN/HOW CONV EVOLVES THROUGH TDA. SVRL POSSIBILITIES EXIST YET MOST CONVINCING NR TERM IS W/SUBTLE SW LIFTING OUT OF MO. EARLIER MID LVL RTNS ACRS WRN IL FINALLY SHOWING SOME SIGNS OF LIFE W/CONVN NOW SEEN NR EFFINGHAM IL AND ON ERN EDGE OF MID LVL HGT FALLS ASSOCD/W DEEP PLAINS TROUGH SPREADING EWD AND COLLOCATED W/SECONDARY THETA-E SURGE ADVTG NEWD OUT OF THE LWR MS VALLEY. EXTRAPOLATION PUTS THIS INTO SWRN ZONES BY 12Z ASSUMING IT MAINTAINS BUT IS REFLECTED IN 06Z RUC PROGS. HWVR EXPECTATIONS AT THIS POINT TEMPERED BY SVR EML IN PLACE AND CAPTURED WELL IN 00Z RAOBS LAST EVENING AT KILX/KSGF AND WHICH WILL BE SLOW TO ERODE THIS MORNING. OTHERWISE MOST REALISTIC MODEL SOLUTION LIES W/00Z HIGH RES NMM WHICH HAS A SUPERIOR HANDLE ON INTENSE SVR SQUALL LINE STRETCHING FM NW MO INTO N TX THIS MORNING. DOUBT THIS LINE WILL DECAY ENTIRELY GIVEN MESOSCALE DVLPMNT OF LARGE BOW HEAD AND DEEP OUTFLW BNDRY ALTHOUGH SOME WEAKENING XPCD THROUGH MID MORNING AS IT APPROACHES MS RVR VALLEY. HWVR DOWNSTREAM AIRMASS AT THAT TIME LOOKS TO DESTABILIZE ENOUGH EVEN W/DIRTY WARM SECTOR TO LEAD TO A RE-INTENSIFICATION THIS AFTN W/STILL UNCERTAIN TIMING PUTTING IT INTO NW IN TWD 21Z AND WELL INTO CWA BY 00Z W/SOME RISK FOR DAMAGING WINDS/HAIL THIS EVENING. SECONDARY CONCERNS THEN TIED TO STG CDFNT WHICH ACCELERATES EWD TONIGHT AS MID LVL TROUGH OPENS AND LOOKS TO PARTIALLY PHASE W/RETROGRADING DEEP LOW OVR SW HUDSON BAY. DEEP FORCED ASCENT ALG THE CDFNT AND SIG UPSTREAM DRY INTRUSION SHLD AIDE REDVLPMNT OF ANOTHER CONV LINE AFT MIDNIGHT WHICH WILL TRANSLATE RAPIDLY EWD. DRYSLOT OVERSPREADING AREA LATE TONIGHT SHLD PROMOTE SOME HEATING SAT MORNING W/AT LEAST LIMITED INSOLATION XPCD. THIS SHLD SETUP ANOTHER POTENTIAL LINE OF LOW TOPPED STORMS BY LATE MORNING/EARLY AFTN AS COLD CORE UPR TROUGH SWINGS THROUGH AND HOLDS AT LEAST A MARGINAL HAIL RISK AS DENOTED IN DY2 OUTLOOK ALTHOUGH TIMING SUGGEST BTR CHCS CNTRL AND EAST. WILL KEEP CLOSE TO CONTINUITY FOR TEMPS THROUGHOUT YET A BIT WARMER FOR HIGHS THIS AFTN AND SAT. && .LONG TERM... SUNDAY THROUGH THURSDAY...THE MAIN CHALLENGES THIS COMING WEEK INCLUDE THE POSSIBILITY OF THE SHOWERS AND THUNDERSTORMS LATE IN THE FORECAST PERIOD AS AN UPPER LEVEL SYSTEM EJECTS INTO THE AREA. BUT BEFORE THIS SYSTEM ARRIVES...A LARGE UPPER LEVEL SYSTEM WILL LIFT NORTH AWAY FROM THE REGION EARLY SUNDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST. NOT MUCH COLD AIR WILL BE ABLE TO MAKE IT INTO THE AREA AS RETURN FLOW WILL BEGIN EARLY NEXT WEEK. HOWEVER...WITH CLEAR TO PARTLY CLOUDY SKIES AND LIGHT WINDS AND A RELATIVELY DRY AIRMASS SUNDAY NIGHT...HAVE LOWERED TEMPS TO BASICALLY 37F TO 39F. THE GFS MEX OVER THE LAST 3 TO 4 DAYS APPEARS TO BE ON TRACK WITH TRENDING DOWN LOWS SUNDAY NIGHT INTO THE 30S. FROST IS STILL POSSIBLE SUNDAY NIGHT...ESPECIALLY OVER NORTHEAST AREAS. AFTER THAT...TEMPERATURES SHOULD RECOVER CLOSE TO NORMAL BY WEDNESDAY AS A WEAK UPPER LEVEL RIDGE PERSISTS OVER THE REGION. TIMING OF THE SECOND SYSTEM AND THE POSSIBILITY OF SOME WEAKER SHORTWAVES REACHING THE AREA EARLIER BEFORE THE MAIN SYSTEM ARE STILL IN QUESTION...SO WAS HESITANT TO MAKE ANY CHANGES PAST MONDAY. THE NEW 00Z ECMWF BRINGS A NEGATIVELY TILTED AND POTENT SHORTWAVE INTO THE MID MISSISSIPPI VALLEY LATE IN THE PERIOD WHICH WOULD INDICATE A VERY ACTIVE WEATHER PATTERN. && .AVIATION... STG WAA CONTS THIS MORNING DOWNSTREAM OF DEEP PLAINS LOW PRES. HWVR STEEP EML IN PLACE PUTTING A DISTINCT LID ON ANY CONV OVERTURNING WITHIN ELEVATED INSTABILITY PLUME AND OTHER THEN A STRAY LIGHT SHOWER/SPRINKLE NO PROBLEMS ANTICIPATED THROUGH DAYBREAK. OTHERWISE SUBTLE SW TROUGH EJECTING NEWD OUT OF MO AND ENCROACHING MID LVL HGT FALLS ASSOCD/W DEEP PLAINS TROUGH WILL LEAD TO A GRADUAL EROSION OF EML WHILE DEEPER THETA-E SURGE OCCURS AND CURRENT ARCING LINE OF MID LVL RTNS FM NR KSTL TO KPAH A MARKER FOR LEADING EDGE OF BTR MID LVL ASCENT ASSOCD/W THIS FTR. EXTRAPOLATION PUTS IT INTO AREA TWD 13Z AND FODDER FOR PSBL TEMPO CB INSERTION W/12Z ISSUANCE. FOR NOW WILL RELEGATE MENTION TO AFTN PD TIED TO PREFNTL TROUGH SPRTG INTENSE SQUALL LINE/LARGE BOW ECHO FM NW MO-NC TX AND ITS LIKELY INTACT TREK E/NE INTO THE AREA BY LT AFTN/EVENING. VFR OTHERWISE W/INCREASING GRADIENT FLW AND GUSTS ~ 25KTS BY EARLY AFTN. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...HOLSTEN LONG TERM...SKIP AVIATION...HOLSTEN in AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DES MOINES IA 1145 PM CDT THU MAY 1 2008 UPDATED AVIATION DISCUSSION .SHORT TERM...TONIGHT SURFACE LOW OVER EASTERN NEBRASKA AT 20Z WITH DRY LING PUSHING ACROSS THE MO RIVER ALONG THE WESTERN IA BORDER. PREFER GFS AND RUC SOLN THIS EVENING WITH DRY LINE MOVING INTO THE WESTERN FA AND SURFACE LOW REMAINING NW OF IA. DRY LINE SHOULD STALL AS IT REACHES CENTRAL IA SINCE UPPER LEVEL SUPPORT IS HANGING BACK TO THE WEST. NARROW AXIS OF CAPES AND CNVG EAST OF DRY LINE WITH INCREASING DEEP SHEAR AND GOOD LOW-LVL SHEAR. TSTM CHANCES INHIBITED BY STRONG MID LVL CAP. SHOULD CAP BREAK...EXPECT PSBL SVR WX IN WRN AND NW CWA THIS EVENING FM SCT TO ISOLD STORMS. MCS MAY MOVE INTO SRN IA AFTER 06Z AND WILL FORECAST HIGHER POPS THEN. SEVERE CHANCES WILL BE LESS HOWEVER. .LONG TERM...FRIDAY THROUGH WEDNESDAY SURFACE LOW EXPECTED TO MOVE NE THROUGH IA ON FRIDAY AS A VIGOROUS TROUGH ROTATES AROUND SE SIDE OF UPPER LOW. THIS SHOULD MAKE FOR RAPIDLY CHANGING WEATHER AS REMAINS OF OVERNIGHT CONVECTION LIFTS NEWD THROUGH EASTERN PORTIONS OF IA. REDEVELOPMENT OF SECOND ROUND OF CONVECTION IS EXPECTED AROUND MIDDAY...ESPECIALLY N AND E. THERE WOULD BE SOME THREAT OF SEVERE WEATHER EAST OF MARSHALLTOWN-GRINNELL WITH FAVORABLE CONDITIONS FOR LOW-TOPPED ROTATING STORMS BUT RESIDENCE TIME IN OUR FORECAST AREA WILL BE SHORT. FRIDAY NIGHT AND SATURDAY...UPPER LOW AND COLD POOL MOVE ACROSS IA. RAIN IN DEFORMATION ZONE WILL BE MOST PROLONGED NW OF FORT DODGE...AND FORECAST TEMPERATURE PROFILES EVEN INDICATE A MIX OF RAIN AND SNOW IS POSSIBLE LATE FRIDAY NIGHT EARLY SATURDAY. THIS WILL HOLD TEMPERATURES DOWN AROUND OR BELOW 50 DEGREES THROUGH SATURDAY. RAINFALL COLD BE SUFFICIENT IN THE EAST AND NORTH TO BRING RIVERS BACK UP TOWARD FLOOD STAGE. HOWEVER...AT THIS TIME MOISTURE DOES NOT LOOK NEARLY AS DEEP AS PREVIOUS SYSTEM AND STORM LOOK TO BE PROGRESSIVE. THUS...TOTAL RAINFALL SHOULD BE LESS THAN ONE INCH IN GENERAL AND AS SUCH FLASH FLOODING WOULD BE LESS OF A CONCERN. SUNDAY AND MONDAY LOOK TO BE NICE WITH A SLOW MODERATION IN TEMPERATURES. AFTER THAT...GFS MODEL WOULD LIKE TO BRING IN WARM ADVECTION AND A CHANCE FOR PRECIPITATION AS EARLY AS MONDAY NIGHT...AND HAVE IT EXIT ALREADY ON WEDENSDAY. THIS IS QUITE A BIT FASTER THAN PREVIOUS RUNS...AND ECMWF IS SLOWER AND FARTHER TO THE SOUTH WITH ITS FORCING FOR PRECIPITATION. RESULT IN FORECAST IS A CHANCE OF SHOWERS AND THUNDER CENTERED ON WEDNESDAY...WITH BEGIN AND END TIME SPREAD OUT INTO ADJOINING DAYS AND EXACT TIMING TO BE DETERMINED. && .AVIATION...02/06Z THREAT OF CONVECTION IS LEAVING CENTRAL IA TEMPORARILY. BUT...NEXT MCS IN EASTERN KS WILL BE STREAKING NORTHEAST INTO SRN IA AROUND 08-09Z. WILL BEING TS MENTION SOUTH TO NORTH AFT 09Z. AS SFC LOW MIGRATES OVR AREA AFT 12Z...WILL HAVE -SHRA/TSRA MUCH OF THE AREA UNTIL DRIER AIR MOVES IN FROM THE SW. NRN SITES WILL BE STUCK IN THE IFR/MVFR CONDITIONS LONGER WITH WRAP AROUND SHRA INTO FRI EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE && $$ SHORT TERM...JOHNSON LONG TERM...JUNGBLUTH AVIATION...MOYER ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1120 PM MDT THU MAY 1 2008 .SYNOPSIS... 141 PM MDT THU MAY 1 2008 ANALYSIS OF WATER VAPOR IMAGERY INDICATES NEGATIVELY-TILTED LONGWAVE TROUGH STRETCHING FROM THE OK/TX PANHANDLE NORTHWESTWARD INTO BRITISH COLUMBIA. SEVERAL PIECES OF ENERGY WERE MOVING THROUGH THE MEAN FLOW INCLUDING ONE OVER COLORADO CURRENTLY IMPACTING WEATHER ACROSS THE GLD CWA. FOLTZ && .DISCUSSION... 141 PM MDT THU MAY 1 2008 MAIN FORECAST CONCERNS IN THE SHORT-TERM REVOLVE AROUND PRECIP CHANCES AND TYPE THROUGH TOMORROW AS WELL AS STRONG WINDS FROM FRIDAY MORNING THROUGH FRIDAY NIGHT. MODELS ARE IN DECENT AGREEMENT ON THE EVOLUTION OF DEVELOPING SURFACE LOW OVER SOUTHWEST KANSAS. AS THIS FEATURE CONTINUES TO DEEPEN AND SLIDE NORTHEASTWARD INTO THE MIDDLE MISSOURI RIVER VALLEY BY FRIDAY MORNING...NORTHWESTERLY WINDS WILL RAPIDLY INCREASE TO AT LEAST ADVISORY CRITERIA. LOCAL WIND GUST TOOL AND AVERAGE OF GUIDANCE WOULD INDICATE HIGH WIND WARNING CRITERIA WILL BE MET OVER AT LEAST THE WESTERN HALF OF THE CWA. WIND ADVISORY CRITERIA LOOKS TO BE A CERTAINTY OVER THE ENTIRE CWA. AS A RESULT...HAVE HOISTED A HIGH WIND WATCH FROM 15Z FRIDAY THROUGH 06Z SATURDAY. WILL BRIEF EVENING SHIFT AND ALLOW THEM TO FINE TUNE THE HIGHLIGHT BASED ON LATER GUIDANCE. IN TERMS OF PRECIPITATION IN THE SHORT-TERM...COULD SEE A MIXED BAG ACROSS THE CWA WITH PORTIONS OF EASTERN COLORADO AND SOUTHWESTERN NEBRASKA RECEIVING ACCUMULATING SNOWFALL WHILE PRECIP LOOKS TO REMAIN LIQUID OVER THE SOUTHEASTERN HALF OF THE CWA. A MIX OF RAIN AND SNOW ARE POSSIBLE FROM MCCOOK THROUGH GOODLAND...ESPECIALLY FRIDAY MORNING. 12Z/01 RUC13 PUTS DOWN AS MUCH AS 4 TO 6 INCHES OVER WESTERN KIT CARSON AND MUCH OF YUMA COUNTIES THROUGH. IF THIS SOLUTION WERE TO VERIFY...BLIZZARD CONDITIONS COULD BE MET GIVEN ANTICIPATED WIND SPEEDS. NAM/GFS ARE LOWER BUT STILL ACCUMULATE A FEW INCHES BEFORE TAPERING OFF FRIDAY NIGHT. BY SATURDAY...CLOSED H5 LOW TRANSITIONS EASTWARD INTO THE WESTERN GREAT LAKES WITH WEAK RIDGING BUILDING INTO THE CWA. WITH NORTHWESTERLY FLOW CONTINUING AND H85 TEMPS OF 5-10C...MAX TEMPS WILL STRUGGLE TO GET OUT OF THE MID 50S. SHOULD SEE TEMPS MAKE A QUICK REBOUND ON SUNDAY AS RIDGE AXIS IS RIGHT ON TOP OF THE CWA. H85 TEMPS WARM TO NEAR 20C RESULTING IN SURFACE TEMPS IN THE LOW TO MID 70S. FOR THE EXTENDED PERIOD OF MONDAY THROUGH THURSDAY...ESSENTIALLY FOLLOWED A BLEND OF THE ECMWF AND THE GFS ENSEMBLE MEAN. TROUGH STARTS TO DIG SOUTHWARD OVER THE WESTERN CONUS BY MONDAY AFTERNOON WITH A LEAD SHORTWAVE TROUGH APPROACHING THE AREA. BROUGHT IN THE MENTION OF THUNDER STARTING MONDAY NIGHT GIVEN INSTABILITY AND THERMAL PROFILES. CLOSED H5 LOW PROGGED TO EJECT INTO THE CENTRAL HIGH PLAINS ON TUESDAY. HAVE CARRIED SLIGHT CHANCE POPS THROUGH WEDNESDAY AFTERNOON AS IT APPEARS SYSTEM WILL BE STRONG ENOUGH TO SEE MOISTURE WRAP AROUND THE BACK SIDE. TEMPS WILL START TO REBOUND ON THURSDAY WITH H85 TEMPS WARMING BACK TO AROUND 15C. FOLTZ && .AVIATION... 1108 PM MDT THU MAY 1 2008 FOR THE 06Z TAFS...LINE OF SHOWERS FROM KLBF TO KCBK WILL CONTINUE TO SLOWLY SLIDE EASTWARD IMPACTING KMCK BY 08Z. UPSTREAM OBS INDICATE MVFR AND LOW VFR CONDITIONS UNDER THE SHOWERS. ONCE THESE SHOWERS PASS...CONDITIONS SHOULD IMPROVE TO VFR THROUGH MOST OF THE DAY...THOUGH MORE SCATTERED SHOWERS COULD BRING BRIEF MVFR CONDITIONS. AFTER 00Z TIME HEIGHT DISPLAYS OF THE GFS INDICATE DETERIORATING CONDITIONS BACK TO MVFR. NORTHWEST WINDS WILL BE BREEZY TO VERY WINDY FOR ALL OF THE TAF PERIOD. SFJ && .GLD WATCHES/WARNINGS/ADVISORIES... KS...HIGH WIND WATCH FROM 9 AM MDT /10 AM CDT/ FRIDAY THROUGH FRIDAY EVENING FOR KSZ001>004-013>016-027>029-041-042. NE...HIGH WIND WATCH FROM 9 AM MDT /10 AM CDT/ FRIDAY THROUGH FRIDAY EVENING FOR NEZ079>081. CO...HIGH WIND WATCH FROM 9 AM MDT FRIDAY THROUGH FRIDAY EVENING FOR COZ090>092. && ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1205 AM CDT FRI MAY 2 2008 .UPDATE... .SHORT TERM... LINE OF STG-SVR TSRA ~30SM WIDE CONTINUES TO MOVE E20MPH WHILE INDIVIDUAL CELLS ARE SPRINTING NE30. AT 1145 PM CDT...THE LINE WAS ORIENTED GENERALLY ALONG & JUST E OF THE KS TURNPIKE FROM CENTRAL WABAUNSEE COUNTY IN NE KS...TO NEAR SOUTH HAVEN...TO ERN GARFIELD COUNTY IN NC OK. REPAINTED POP/WX/QPF GRIDS TO REFLECT MOST RECENT RADAR TRENDS AS WELL AS TEMPS & DEWPOINTS. .AVIATION... 06Z TAF ISSUANCE: [KRSL/KSLN/KHUT/KICT/KCNU] NO DOUBT PRIMARY FOCUS IS ON BEHAVIOR OF ABOVE-MENTIONED TSRA AS COLD FRONT PUSHES E/SE ACROSS SE KS THE REST OF THE NIGHT. AS SUCH KCNU TO BE WATCHED CLOSELY AS POTENTIAL FOR VSBYS OF 2-3SM (+TSRA) CERTAINLY EXISTS THRU ~12Z. SECOND CONCERN IS INCREASING NW WINDS THAT`LL SPREAD E ACROSS C & SC KS FROM LATE THIS MORNING THROUGH THIS EVENING. SUSTAINED SPEEDS OF 30-35KTS ARE LIKELY ACROSS THESE AREAS FROM ~15Z-03Z. && .PREV DISCUSSION... /ISSUED 323 PM CDT THU MAY 1 2008/ DISCUSSION... MAIN FORECAST CONCERN REVOLVES AROUND SEVERE CHANCES OVERNIGHT. SYNOPSIS: CURRENTLY HAVE A STRONG UPPER WAVE DIVING ACROSS SOUTHERN CO/NORTHERN NM. VIS SATELLITE SHOWING SOME CU DEVELOPING OVER FAR WESTERN KS AS THE LEADING EDGE OF COOLER MID LEVEL TEMPS START TO OVERSPREAD THE AREA. AT THE SURFACE LOOSE DRY LINE IS SITUATED ALONG A EMP TO WLD LINE WITH A SURFACE LOW OVER EASTERN NE AND ANOTHER ONE TAKING SHAPE OVER THE OK PANHANDLE WHERE SURFACE PRESSURE FALLS HAVE BEEN MAXIMIZED OVER THE LAST COUPLE OF HOURS. TONIGHT: DRYLINE IS EXPECTED TO SLOWLY WORK EAST THROUGH 00Z FRI AS STRONG SOUTHERLY WINDS CONTINUE TO INCREASE MOISTURE ACROSS SE KS. IT LOOKS LIKE THE RUC...GFS AND NAM ARE STILL OVERDOING THE SURFACE DEWPOINTS ACROSS SE KS WITH MOST SHOWING BETWEEN 65-68 DEGREES...WITH 62-64 MORE REALISTIC. AS EXPECTED THE CAP IS CURRENTLY HOLDING STRONG BUT WILL START TO ERODE QUICKLY AS THE COOLER MID LEVEL AIR OVERSPREADS THE DRYLINE. MODELS ARE STILL BACKING THE SURFACE WINDS AROUND 00Z AS PRESSURE FALLS CONTINUE TO INCREASE OVER THE HIGH PLAINS. THE IMPORTANT QUESTION FOR THE FIRST PART OF THIS PERIOD IS WHETHER THERE WILL BE ENOUGH CONVERGENCE ALONG THE FRONT/DRYLINE TO INITIATE STORMS BEFORE DARK. CURRENT THINKING IS THAT AN HOUR EITHER SIDE OF 00Z WOULD BE THE MOST LIKELY TIME FOR STORMS TO DEVELOP PRIOR TO DARK. ONE DIFFERENCE WITH THE LATEST MODEL RUNS AND WHAT IS OCCURRING...IS THAT THE SURFACE BOUNDARY IS ORIENTED MORE NE TO SW WHICH MEANS THAT IT WILL BE EASIER TO GET CONVERGENCE ALONG THE BOUNDARY SINCE BACKED WINDS WILL NOT BE NEEDED. OBVIOUSLY ANY STORMS THAT FIRE BEFORE DARK WILL QUICKLY BECOME SEVERE. MODELS CONTINUE TO BACK THE DRYLINE WEST AFTER 00Z AS THE SURFACE LOW TRACKS INTO NORTH CENTRAL OK. IF STORMS DO NOT DEVELOP BEFORE DARK...THEY WILL LIKELY DEVELOP AFTER 03Z AS THE SYNOPTIC BOUNDARY CATCHES UP WITH THE DRYLINE WHICH WILL ALSO COINCIDES WITH THE BETTER UPPER DYNAMICS GETTING INTO THE AREA. THE STORMS AFTER DARK WILL BE MORE LINEAR IN NATURE BUT WILL STILL HAVE A GOOD CHANCE AT PRODUCING LARGE HAIL AND DAMAGING WINDS. FRI-SUN: BY 18Z FRI THE UPPER LOW WILL BE LOCATED OVER SOUTH CENTRAL NE/NORTH CENTRAL NE. THIS WILL PLACE MOST OF NORTHERN KS IN A PRIME AREA FOR HIGH NW WINDS AND CURRENTLY HAVE HIGH CONFIDENCE THAT A WIND ADVISORY WILL BE NEEDED FOR OUR CENTRAL KS COUNTIES FRI AFTERNOON. HOWEVER AFTER COORDINATING WITH SURROUNDING OFFICES...FEEL IT WOULD BE CONFUSING GOING WITH AN NPW NOW...CONSIDERING DDC HAS A WIND ADVISORY OUT FOR EARLY THIS EVENING WITH ADDITIONAL HEADLINES LIKELY OVERNIGHT. THEREFORE WILL BRIEF THE MIDNIGHT SHIFT ON THE SITUATION AND LET THEM ISSUE. CONTINUED WITH SHOWERS OVER THE NORTHERN HALF OF THE FORECAST AREA FOR FRI INTO FRI NIGHT GIVEN THE PROXIMITY TO THE UPPER LOW. HOWEVER NOT EXPECTING ANYTHING TOO WIDESPREAD. THE MAIN WEATHER STORY OVER THE WEEKEND WILL CONTINUE TO BE THE UNSEASONABLY COOL MORNING TEMPERATURES WITH 30S LIKELY FOR THE NORTHERN HALF OF THE FORECAST AREA FOR BOTH SAT AND SUN MORNING AS THE UPPER WAVE PUSHES INTO THE OHIO VALLEY. MON-THU: DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST THROUGH THESE PERIODS. BOTH ECMWF AND GFS CONTINUE TO ADVERTISE ANOTHER SHORTWAVE TRACKING INTO THE DESERT SW ON MON AND INTO THE CENTRAL PLAINS FOR WED INTO THU. THIS WILL ALLOW RETURN FLOW TO SETUP ACROSS THE PLAINS FOR MON INTO TUE. THERE WILL LIKELY BE TWO MODES OF PRECIP CHANCES THROUGH THESE PERIODS...ONE WITH THE INITIAL MOISTURE SURGE AND THE OTHER WHEN THE UPPER DYNAMICS LIFT OUT. FOR NOW WILL NOT GET TOO CUTE AND WILL INCREASE POPS SLOWLY FROM MON NIGHT INTO WED. LAWSON AVIATION...18Z TAF ISSUANCE THE MAIN CONCERN WITH THIS FORECAST PACKAGE WILL BE THE POSITION OF THE FRONT THIS EVENING AND WHERE THE BEST CHANCES OF CONVECTION WILL TAKE PLACE. LATEST SURFACE ANALYSIS WAS SHOWING THE SURFACE FLOW BEGINNING TO VEER OUT ACROSS SOUTH CENTRAL AND SOUTHEAST KANSAS AS THE FRONTAL BOUNDARY BEGINS TO STALL OUT ALONG AND EAST OF THE I-35 CORRIDOR. THIS BOUNDARY MAY SERVE AS A FOCUS FOR AN ISOLATED THUNDERSTORM OR TWO LATE THIS AFTERNOON...BUT IT APPEARS LIKE THE BEST SHOT FOR THUNDERSTORMS WILL BE WHEN THE UPPER LEVEL SUPPORT MOVES THROUGH THIS EVENING AND HELPS IGNITE THE FRONT MAINLY ALONG AND EAST OF THE KANSAS TURNPIKE TONIGHT. WE ARE ALSO PLANNING ON ISSUING A WIND ADVISORY THIS AFTERNOON FOR AREAS ALONG AND EAST OF THE KANSAS TURNPIKE. COX && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 50 63 39 63 / 70 10 10 10 HUTCHINSON 46 61 38 63 / 50 20 20 0 NEWTON 49 63 38 62 / 70 10 20 10 ELDORADO 51 65 39 62 / 80 10 10 10 WINFIELD-KWLD 51 66 39 64 / 80 10 10 10 RUSSELL 40 56 35 60 / 30 40 30 10 GREAT BEND 41 56 36 63 / 30 30 20 0 SALINA 47 58 35 62 / 40 30 30 10 MCPHERSON 47 60 37 62 / 50 20 20 10 COFFEYVILLE 58 69 42 63 / 80 20 10 10 CHANUTE 56 67 41 59 / 80 20 20 10 IOLA 56 67 41 59 / 80 20 20 10 PARSONS-KPPF 57 69 42 61 / 80 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 934 PM EDT SAT MAY 3 2008 .SHORT TERM.../THE REST OF TONIGHT/...UPDATED A FEW MINOR CHANGES WERE MADE TO THE FORECAST FOR THE REST OF TONIGHT. LATEST SURFACE OBS INDICATE THAT HOURLY TEMPERATURES HAVE A BEEN JUST SLIGHTLY SLOWER TO FALL THAN PREVIOUSLY FORECAST...SO ADJUSTMENTS WERE MADE TO ACCOUNT FOR THIS WITH A GENERAL DEGREE OR TWO INCREASE IN HOURLY TEMPERATURES THROUGH 12Z. ALSO INCREASED OVERNIGHT LOW TEMPERATURES BY A DEGREE OR TWO ACROSS THE BOARD PER THE AFOREMENTIONED SURFACE OB TRENDS AND TOWARD THE 18Z SLIGHTLY WARMER MAVMOS NUMBERS. ALSO REMOVED MENTION OF PRECIPITATION FROM THE OVERNIGHT PERIOD AS CURRENT RADAR IMAGERY INDICATES THAT ANY REMAIN ISOLATED RAIN SHOWERS WILL HAVE MOVED OUT OF EASTERN KENTUCKY BY 3Z. THERE WAS ALSO A BIT OF EVENING AND OTHER OUTDATED WORDING IN THE FIRST PERIOD OF THE ZONES...SO ALL OF THAT WAS REMOVED AS WELL AND REPLACED WITH FRESH WORDING. ALSO RERAN THE WEATHER AND QPF FORECASTS TO REFLECT THE CHANGES MADE TO OVERNIGHT PRECIPITATION CHANCES. WINDS WILL STAY STRONG AND PERSISTENT ENOUGH TO KEEP FOG OUT OF THE PICTURE TONIGHT. REST OF FORECAST WAS IN GOOD SHAPE. UPDATED ZONES ALREADY OUT. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /THE REST OF TODAY/ THE OCCLUDED FRONT HAS COMPLETED IT/S TRACK THROUGH EASTERN KENTUCKY. HOWEVER...SURFACE TROUGH STILL HAS TO MAKE IT THROUGH THE AREA. THIS SFC BOUNDARY IS CURRENT SLIDING THROUGH SOUTHEASTERN INDIANA AND WEST CENTRAL KENTUCKY. A BAND OF SHOWERS...AND THUNDERSTORMS HAVE DEVELOPED AHEAD OF THIS BOUNDARY WITH THE AID OF SURFACE HEATING IN A CLEARING SLOT BETWEEN THE TWO FEATURES. UNFORTUNATELY...SHORT TERM MODELS DO NOT HAVE A VERY GOOD HANDLE ON THE WEATHER ASSOCIATED WITH THE TROUGH. SO FORECAST CHALLENGE WILL FOCUS ON THE POTENTIAL FOR WEATHER AS THE SURFACE TROUGH ENTERS EASTERN KENTUCKY LATE LATE THIS AFTERNOON AND EARLY EVENING. MORE SPECIFICALLY...WILL ONGOING SHOWER ACTIVITY CONTINUE TO DEVELOP SOUTHWARD ALONG THE TROUGH AS IT MOVES INTO EASTERN KENTUCKY. GOES SOUNDING DATA INDICATES A WEAK MID LEVEL CAP IN PLACE AHEAD OF THE LINE OF SHOWERS AND THUNDERSTORMS IN SE INDIANA...BECOMING SLIGHTLY STRONGER FURTHER SOUTH IN SOUTH CENTRAL KENTUCKY. SATELLITE LOOP SHOWS SOME PARTIAL CLEARING BEGINNING TO WORK IT/S WAY INTO EASTERN KENTUCKY AS WELL. RUC MESOANALYSIS SEEMS TO HAVE PICKED UP ON THE PARTIAL CLEARING AS IT SHOWS AN INCREASE IN SFC BASED INSTABILITY...FROM 0 TO -3 LATE THIS AFTERNOON AS WELL AS AN INCREASE IN CAPE...FROM 50 TO 400 J/KG. WHILE NOT IMPRESSIVE...THIS SHOULD BE ENOUGH TO GENERATE SOME SCATTERED SHOWERS AND POSSIBLY AN ISOLATED THUNDERSHOWER OR TWO AS THE TROUGH MOVES INTO THE AREA...DESPITE THE WEAK CAP. REGIONAL RADAR LOOP SEEMS TO CONFIRM THIS SCENARIO AS THERE IS A GRADUAL EXPANSION OF SHOWERS BUILDING TO THE SOUTH. WILL CARRY A 20 TO 40 POP FOR LATE THIS AFTERNOON...AND EARLY EVENING TO COVER ANY POSSIBLE DEVELOPMENT. HIGHER POPS WILL BE CARRIED IN THE NORTH...WHILE LOWEST POPS ARE RESTRICTED TO THE SOUTHWEST. THE THREAT OF PRECIP SHOULD END THIS EVENING WITH LOSS OF SFC HEATING. DRY WEATHER WITH SEASONABLE TEMPS WILL PERSIST THROUGH THE REMAINDER OF THE SHORT TERM PERIOD. MONDAY MORNING WILL BE CHILLY IN THE VALLEYS AND AGAIN TUESDAY MORNING IN THE EAST. MOST LIKELY NIGHT FOR A STRONG RIDGE VALLEY SPLIT WILL BE MONDAY NIGHT AS A WEAK SE GRADIENT WIND BEGINS TO DEVELOP ON THE WEST SIDE OF HIGH PRESSURE. OTHERWISE...USED A BLEND OF MOS GUIDANCE FOR HIGHS. CLOSER TO THE COOLER MET FOR MONDAY UNDER NORTHERLY FLOW...AND CLOSER TO THE WARMER MAV ON TUESDAY UNDER SOUTHERLY FLOW. .LONG TERM.../TUESDAY THROUGH SATURDAY/ THERE ARE SOME DIFFERENCES IN THE MODELS FOR THE LONG TERM PERIOD. GENERALLY SIDED CLOSER TO THE ECMWF AND HPC MANUAL PROGS THROUGH THE PERIOD. THE THE EARLY PORTION OF THE FORECAST PERIOD SHOULD BE DRY...AS HIGH PRESSURE OVER THE SOUTHEAST CONUS KEEPS US DRY. BY WEDNESDAY...A LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS...WITH ANOTHER LOW OVER THE GREAT LAKES REGION. A COLD FRONT IN BETWEEN THE LOWS WILL DROP SOUTH DURING THE DAY...INCREASING THE CHANCE FOR SHOWERS AND THUNDERSTORMS. THE FRONT SHOULD STALL OUT AND BEGIN TO MOVE BACK NORTH AS A WARM FRONT WEDNESDAY NIGHT AS THE LOW OVER THE PLAINS MOVES EAST. THIS LOW SHOULD THEN MOVE OVER KENTUCKY LATE THURSDAY AND THURSDAY NIGHT. THIS WILL KEEP THE CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE AREA. THE LOW SHOULD BE EXITING OFF TO THE EAST FRIDAY...BUT SHOULD STILL BE CLOSE ENOUGH TO KEEP A CHANCE OF SHOWERS IN THE AREA. DRY WEATHER IS EXPECTED FRIDAY NIGHT AND SATURDAY AS HIGH PRESSURE BUILDS IN OVER THE AREA. && .AVIATION.../00Z TO 24Z/ THE COLD/OCCLUDED FRONT IS FINALLY CROSSING EAST KENTUCKY AND WITH IT A FEW ISOLATED SHOWERS ARE POPPING UP...MAINLY EAST OF JKL. CIG HEIGHTS EVEN WITH THE SHOWERS ARE STILL RUNNING 6 TO 8K FEET ABOVE GROUND LEVEL. AS A RESULT...THE AVIATION CONDITIONS WILL REMAIN VFR THIS EVENING AND OVERNIGHT. THE CLOUDS ASSOCIATED WITH THE FRONT WILL CLEAR OUT LATE THIS EVENING WHILE LOWER ONES OVER SOUTHERN INDIANA PIVOT BY JUST TO THE NORTH OF THE CWA LATER TONIGHT. WITH MOSTLY CLEAR SKIES...THE INPUT OF SOME MOISTURE FROM SHOWERS THIS MORNING AND WINDS SETTLING DOWN TOWARD MIDNIGHT...LIGHT FOG COULD DEVELOP IN THE VALLEYS TOWARDS DAWN. HAVE LEFT A TEMPO GROUP IN FOR THIS AT SME AND LOZ. DURING THE DAY SUNDAY...CONDITIONS WILL REMAIN VFR WITH JUST SOME SCATTED CLOUDS AT 4-5K FEET AROUND. WINDS WILL BE STRONGEST AND GUSTIEST OVER THE NEXT FEW HOURS ALONG AND BEHIND THE FRONT...THEN THEY WILL COME AROUND TO THE NORTH OVERNIGHT SETTLING DOWN INTO THE LIGHT CATEGORY BY MIDNIGHT. THE WINDS WILL REMAIN LIGHT...GENERALLY FROM THE NORTH FOR SUNDAY. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...RAY/AR LONG TERM....WJM AVIATION...GREIF ky AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE JACKSON KY 820 PM EDT SAT MAY 3 2008 .SHORT TERM.../THE REST OF TODAY/ THE OCCLUDED FRONT HAS COMPLETED IT/S TRACK THROUGH EASTERN KENTUCKY. HOWEVER...SURFACE TROUGH STILL HAS TO MAKE IT THROUGH THE AREA. THIS SFC BOUNDARY IS CURRENT SLIDING THROUGH SOUTHEASTERN INDIANA AND WEST CENTRAL KENTUCKY. A BAND OF SHOWERS...AND THUNDERSTORMS HAVE DEVELOPED AHEAD OF THIS BOUNDARY WITH THE AID OF SURFACE HEATING IN A CLEARING SLOT BETWEEN THE TWO FEATURES. UNFORTUNATELY...SHORT TERM MODELS DO NOT HAVE A VERY GOOD HANDLE ON THE WEATHER ASSOCIATED WITH THE TROUGH. SO FORECAST CHALLENGE WILL FOCUS ON THE POTENTIAL FOR WEATHER AS THE SURFACE TROUGH ENTERS EASTERN KENTUCKY LATE LATE THIS AFTERNOON AND EARLY EVENING. MORE SPECIFICALLY...WILL ONGOING SHOWER ACTIVITY CONTINUE TO DEVELOP SOUTHWARD ALONG THE TROUGH AS IT MOVES INTO EASTERN KENTUCKY. GOES SOUNDING DATA INDICATES A WEAK MID LEVEL CAP IN PLACE AHEAD OF THE LINE OF SHOWERS AND THUNDERSTORMS IN SE INDIANA...BECOMING SLIGHTLY STRONGER FURTHER SOUTH IN SOUTH CENTRAL KENTUCKY. SATELLITE LOOP SHOWS SOME PARTIAL CLEARING BEGINNING TO WORK IT/S WAY INTO EASTERN KENTUCKY AS WELL. RUC MESOANALYSIS SEEMS TO HAVE PICKED UP ON THE PARTIAL CLEARING AS IT SHOWS AN INCREASE IN SFC BASED INSTABILITY...FROM 0 TO -3 LATE THIS AFTERNOON AS WELL AS AN INCREASE IN CAPE...FROM 50 TO 400 J/KG. WHILE NOT IMPRESSIVE...THIS SHOULD BE ENOUGH TO GENERATE SOME SCATTERED SHOWERS AND POSSIBLY AN ISOLATED THUNDERSHOWER OR TWO AS THE TROUGH MOVES INTO THE AREA...DESPITE THE WEAK CAP. REGIONAL RADAR LOOP SEEMS TO CONFIRM THIS SCENARIO AS THERE IS A GRADUAL EXPANSION OF SHOWERS BUILDING TO THE SOUTH. WILL CARRY A 20 TO 40 POP FOR LATE THIS AFTERNOON...AND EARLY EVENING TO COVER ANY POSSIBLE DEVELOPMENT. HIGHER POPS WILL BE CARRIED IN THE NORTH...WHILE LOWEST POPS ARE RESTRICTED TO THE SOUTHWEST. THE THREAT OF PRECIP SHOULD END THIS EVENING WITH LOSS OF SFC HEATING. DRY WEATHER WITH SEASONABLE TEMPS WILL PERSIST THROUGH THE REMAINDER OF THE SHORT TERM PERIOD. MONDAY MORNING WILL BE CHILLY IN THE VALLEYS AND AGAIN TUESDAY MORNING IN THE EAST. MOST LIKELY NIGHT FOR A STRONG RIDGE VALLEY SPLIT WILL BE MONDAY NIGHT AS A WEAK SE GRADIENT WIND BEGINS TO DEVELOP ON THE WEST SIDE OF HIGH PRESSURE. OTHERWISE...USED A BLEND OF MOS GUIDANCE FOR HIGHS. CLOSER TO THE COOLER MET FOR MONDAY UNDER NORTHERLY FLOW...AND CLOSER TO THE WARMER MAV ON TUESDAY UNDER SOUTHERLY FLOW. .LONG TERM.../TUESDAY THROUGH SATURDAY/ THERE ARE SOME DIFFERENCES IN THE MODELS FOR THE LONG TERM PERIOD. GENERALLY SIDED CLOSER TO THE ECMWF AND HPC MANUAL PROGS THROUGH THE PERIOD. THE THE EARLY PORTION OF THE FORECAST PERIOD SHOULD BE DRY...AS HIGH PRESSURE OVER THE SOUTHEAST CONUS KEEPS US DRY. BY WEDNESDAY...A LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS...WITH ANOTHER LOW OVER THE GREAT LAKES REGION. A COLD FRONT IN BETWEEN THE LOWS WILL DROP SOUTH DURING THE DAY...INCREASING THE CHANCE FOR SHOWERS AND THUNDERSTORMS. THE FRONT SHOULD STALL OUT AND BEGIN TO MOVE BACK NORTH AS A WARM FRONT WEDNESDAY NIGHT AS THE LOW OVER THE PLAINS MOVES EAST. THIS LOW SHOULD THEN MOVE OVER KENTUCKY LATE THURSDAY AND THURSDAY NIGHT. THIS WILL KEEP THE CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE AREA. THE LOW SHOULD BE EXITING OFF TO THE EAST FRIDAY...BUT SHOULD STILL BE CLOSE ENOUGH TO KEEP A CHANCE OF SHOWERS IN THE AREA. DRY WEATHER IS EXPECTED FRIDAY NIGHT AND SATURDAY AS HIGH PRESSURE BUILDS IN OVER THE AREA. && .AVIATION.../00Z TO 24Z/...UPDATED THE COLD/OCCLUDED FRONT IS FINALLY CROSSING EAST KENTUCKY AND WITH IT A FEW ISOLATED SHOWERS ARE POPPING UP...MAINLY EAST OF JKL. CIG HEIGHTS EVEN WITH THE SHOWERS ARE STILL RUNNING 6 TO 8K FEET ABOVE GROUND LEVEL. AS A RESULT...THE AVIATION CONDITIONS WILL REMAIN VFR THIS EVENING AND OVERNIGHT. THE CLOUDS ASSOCIATED WITH THE FRONT WILL CLEAR OUT LATE THIS EVENING WHILE LOWER ONES OVER SOUTHERN INDIANA PIVOT BY JUST TO THE NORTH OF THE CWA LATER TONIGHT. WITH MOSTLY CLEAR SKIES...THE INPUT OF SOME MOISTURE FROM SHOWERS THIS MORNING AND WINDS SETTLING DOWN TOWARD MIDNIGHT...LIGHT FOG COULD DEVELOP IN THE VALLEYS TOWARDS DAWN. HAVE LEFT A TEMPO GROUP IN FOR THIS AT SME AND LOZ. DURING THE DAY SUNDAY...CONDITIONS WILL REMAIN VFR WITH JUST SOME SCATTED CLOUDS AT 4-5K FEET AROUND. WINDS WILL BE STRONGEST AND GUSTIEST OVER THE NEXT FEW HOURS ALONG AND BEHIND THE FRONT...THEN THEY WILL COME AROUND TO THE NORTH OVERNIGHT SETTLING DOWN INTO THE LIGHT CATEGORY BY MIDNIGHT. THE WINDS WILL REMAIN LIGHT...GENERALLY FROM THE NORTH FOR SUNDAY. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...RAY LONG TERM....WJM AVIATION...GREIF ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 713 AM CDT SAT MAY 3 2008 .UPDATE...HAVE MADE A FEW ADJUSTMENTS TO POPS IN GRIDS/ZONES BASED ON CURRENT TRENDS. ZONE UPDATE ALREADY OUT. && MARCOTTE && .PREV DISCUSSION... /ISSUED 422 AM CDT SAT MAY 3 2008/ UPDATE...TORNADO WATCH NOW IN EFFECT FOR ACADIANA. UPDATED ZONES AND WCN ALREADY OUT. MARCOTTE PREV DISCUSSION... /ISSUED 338 AM CDT SAT MAY 3 2008/ DISCUSSION...COLD FRONT HAS ENTERED THE NORTHERN PORTION OF THE FORECAST AREA EARLY THIS MORNING WITH BOUNDARY EXTENDING FROM NEAR ALEXANDRIA TO THE DERIDDER AREA...AND FURTHER SOUTHWEST INTO SOUTHEAST TEXAS. RADAR SHOWING DEVELOPING ACTIVITY OVER SOUTHEAST TEXAS...BUT BULK OF CONVECTION AND STRONGER THUNDERSTORMS OVER CENTRAL LOUISIANA INCLUDING THE ALEXANDRIA AREA. FRONT WITH THUNDERSTORMS TO SETTLE SOUTHEAST ACROSS THE REGION THROUGH THE DAY. LATEST RUC SUGGESTING BOUNDARY REACHING THE ACADIANA AREA BY EARLY AFTERNOON AND EXTENDING SOUTHWEST INTO THE NEAR COASTAL WATERS JUST OFF OF COASTAL SOUTHWEST LOUISIANA AND THE UPPER TEXAS COAST. FRONT EXITS COMPLETELY INTO THE COASTAL WATERS BY LATE AFTERNOON WITH INLAND RAIN CHANCES ENDING. REMAINDER OF THE WEEKEND LOOKING DRY AS SHORTWAVE ENERGY EXITS EAST FOLLOWED BY MID LEVEL RIDGING OVER THE CENTRAL CONUS. RIDGE TO HOLD OVER THE CENTRAL CONUS THROUGH MIDWEEK MAINTAINING AN OVERALL DRY PATTERN. HAVE TO MAINTAIN SOME LOW END POPS HOWEVER AS GFS SHOWING THE POSSIBILITY OF A FEW IMPULSES EJECTING FROM DEVELOPING SOUTHWEST/OLD MEXICO CUT-OFF LOW AND TEMPORARILY BREAKING DOWN RIDGE. LOW EJECTS NORTHEAST INTO THE CENTRAL PLAINS WEDNESDAY AND ON TO THE NORTHEAST THROUGH THE REMAINDER OF THE WEEK WITH HIGH PRESSURE BECOMING REESTABLISHED OVER THE PLAINS. THUS CARRYING NO RAIN CHANCES AFTER MID-WEEK. AVIATION...MVFR CIGS EXPECTED TO PERSIST UNTIL FRONT CROSSES REGION THROUGH THE MORNING. WENT PREVAILING THUNDER AT AEX FOR ANOTHER HOUR OR SO AS LINE CROSSES THAT AREA. EXPECT SCATTERED CONVECTION TO POSSIBLY AFFECT KLFT/KARA THROUGH ABOUT 11Z. KBPT/KLCH LOOKING A LITTLE BETTER AS FAR AS THUNDER GOES FOR THE TIME BEING. VFR CONDITIONS AND DECENT NWRLY WINDS EXPECTED FOR LATER THIS MORNING AND THE AFTERNOON. 25 MARINE...A COLD FRONT WITH SHOWERS AND THUNDERSTORMS WILL ADVANCE ACROSS THE NORTHWEST GULF THIS AFTERNOON AND EVENING. A BRIEF MODERATE OFFSHORE FLOW WILL DEVELOP IN ITS WAKE && .PRELIMINARY POINT TEMPS/POPS... KLCH 83 60 83 64 / 30 0 10 10 KBPT 84 60 81 64 / 30 0 10 10 KAEX 79 55 81 58 / 10 0 10 10 KLFT 81 59 82 61 / 50 0 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...TORNADO WATCH UNTIL 11 AM SATURDAY FOR THE FOLLOWING ZONES: ACADIA...IBERIA...LAFAYETTE...LOWER ST. MARTIN...ST. LANDRY...ST. MARY...UPPER ST. MARTIN...AND VERMILION. TX...NONE. GM...NONE. && $$ la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 422 AM CDT SAT MAY 3 2008 .UPDATE...TORNADO WATCH NOW IN EFFECT FOR ACADIANA. UPDATED ZONES AND WCN ALREADY OUT. && MARCOTTE && .PREV DISCUSSION... /ISSUED 338 AM CDT SAT MAY 3 2008/ DISCUSSION...COLD FRONT HAS ENTERED THE NORTHERN PORTION OF THE FORECAST AREA EARLY THIS MORNING WITH BOUNDARY EXTENDING FROM NEAR ALEXANDRIA TO THE DERIDDER AREA...AND FURTHER SOUTHWEST INTO SOUTHEAST TEXAS. RADAR SHOWING DEVELOPING ACTIVITY OVER SOUTHEAST TEXAS...BUT BULK OF CONVECTION AND STRONGER THUNDERSTORMS OVER CENTRAL LOUISIANA INCLUDING THE ALEXANDRIA AREA. FRONT WITH THUNDERSTORMS TO SETTLE SOUTHEAST ACROSS THE REGION THROUGH THE DAY. LATEST RUC SUGGESTING BOUNDARY REACHING THE ACADIANA AREA BY EARLY AFTERNOON AND EXTENDING SOUTHWEST INTO THE NEAR COASTAL WATERS JUST OFF OF COASTAL SOUTHWEST LOUISIANA AND THE UPPER TEXAS COAST. FRONT EXITS COMPLETELY INTO THE COASTAL WATERS BY LATE AFTERNOON WITH INLAND RAIN CHANCES ENDING. REMAINDER OF THE WEEKEND LOOKING DRY AS SHORTWAVE ENERGY EXITS EAST FOLLOWED BY MID LEVEL RIDGING OVER THE CENTRAL CONUS. RIDGE TO HOLD OVER THE CENTRAL CONUS THROUGH MIDWEEK MAINTAINING AN OVERALL DRY PATTERN. HAVE TO MAINTAIN SOME LOW END POPS HOWEVER AS GFS SHOWING THE POSSIBILITY OF A FEW IMPULSES EJECTING FROM DEVELOPING SOUTHWEST/OLD MEXICO CUT-OFF LOW AND TEMPORARILY BREAKING DOWN RIDGE. LOW EJECTS NORTHEAST INTO THE CENTRAL PLAINS WEDNESDAY AND ON TO THE NORTHEAST THROUGH THE REMAINDER OF THE WEEK WITH HIGH PRESSURE BECOMING REESTABLISHED OVER THE PLAINS. THUS CARRYING NO RAIN CHANCES AFTER MID-WEEK. AVIATION...MVFR CIGS EXPECTED TO PERSIST UNTIL FRONT CROSSES REGION THROUGH THE MORNING. WENT PREVAILING THUNDER AT AEX FOR ANOTHER HOUR OR SO AS LINE CROSSES THAT AREA. EXPECT SCATTERED CONVECTION TO POSSIBLY AFFECT KLFT/KARA THROUGH ABOUT 11Z. KBPT/KLCH LOOKING A LITTLE BETTER AS FAR AS THUNDER GOES FOR THE TIME BEING. VFR CONDITIONS AND DECENT NWRLY WINDS EXPECTED FOR LATER THIS MORNING AND THE AFTERNOON. 25 MARINE...A COLD FRONT WITH SHOWERS AND THUNDERSTORMS WILL ADVANCE ACROSS THE NORTHWEST GULF THIS AFTERNOON AND EVENING. A BRIEF MODERATE OFFSHORE FLOW WILL DEVELOP IN ITS WAKE && .PRELIMINARY POINT TEMPS/POPS... KLCH 83 60 83 64 / 30 0 10 10 KBPT 84 60 81 64 / 30 0 10 10 KAEX 79 55 81 58 / 10 0 10 10 KLFT 81 59 82 61 / 50 0 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...TORNADO WATCH UNTIL 11 AM SATURDAY FOR THE FOLLOWING ZONES: ACADIA...IBERIA...LAFAYETTE...LOWER ST. MARTIN...ST. LANDRY...ST. MARY...UPPER ST. MARTIN...AND VERMILION. TX...NONE. GM...NONE. && $$ la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 338 AM CDT SAT MAY 3 2008 .DISCUSSION...COLD FRONT HAS ENTERED THE NORTHERN PORTION OF THE FORECAST AREA EARLY THIS MORNING WITH BOUNDARY EXTENDING FROM NEAR ALEXANDRIA TO THE DERIDDER AREA...AND FURTHER SOUTHWEST INTO SOUTHEAST TEXAS. RADAR SHOWING DEVELOPING ACTIVITY OVER SOUTHEAST TEXAS...BUT BULK OF CONVECTION AND STRONGER THUNDERSTORMS OVER CENTRAL LOUISIANA INCLUDING THE ALEXANDRIA AREA. FRONT WITH THUNDERSTORMS TO SETTLE SOUTHEAST ACROSS THE REGION THROUGH THE DAY. LATEST RUC SUGGESTING BOUNDARY REACHING THE ACADIANA AREA BY EARLY AFTERNOON AND EXTENDING SOUTHWEST INTO THE NEAR COASTAL WATERS JUST OFF OF COASTAL SOUTHWEST LOUISIANA AND THE UPPER TEXAS COAST. FRONT EXITS COMPLETELY INTO THE COASTAL WATERS BY LATE AFTERNOON WITH INLAND RAIN CHANCES ENDING. REMAINDER OF THE WEEKEND LOOKING DRY AS SHORTWAVE ENERGY EXITS EAST FOLLOWED BY MID LEVEL RIDGING OVER THE CENTRAL CONUS. RIDGE TO HOLD OVER THE CENTRAL CONUS THROUGH MIDWEEK MAINTAINING AN OVERALL DRY PATTERN. HAVE TO MAINTAIN SOME LOW END POPS HOWEVER AS GFS SHOWING THE POSSIBILITY OF A FEW IMPULSES EJECTING FROM DEVELOPING SOUTHWEST/OLD MEXICO CUT-OFF LOW AND TEMPORARILY BREAKING DOWN RIDGE. LOW EJECTS NORTHEAST INTO THE CENTRAL PLAINS WEDNESDAY AND ON TO THE NORTHEAST THROUGH THE REMAINDER OF THE WEEK WITH HIGH PRESSURE BECOMING REESTABLISHED OVER THE PLAINS. THUS CARRYING NO RAIN CHANCES AFTER MID-WEEK. && .AVIATION...MVFR CIGS EXPECTED TO PERSIST UNTIL FRONT CROSSES REGION THROUGH THE MORNING. WENT PREVAILING THUNDER AT AEX FOR ANOTHER HOUR OR SO AS LINE CROSSES THAT AREA. EXPECT SCATTERED CONVECTION TO POSSIBLY AFFECT KLFT/KARA THROUGH ABOUT 11Z. KBPT/KLCH LOOKING A LITTLE BETTER AS FAR AS THUNDER GOES FOR THE TIME BEING. VFR CONDITIONS AND DECENT NWRLY WINDS EXPECTED FOR LATER THIS MORNING AND THE AFTERNOON. 25 && .MARINE...A COLD FRONT WITH SHOWERS AND THUNDERSTORMS WILL ADVANCE ACROSS THE NORTHWEST GULF THIS AFTERNOON AND EVENING. A BRIEF MODERATE OFFSHORE FLOW WILL DEVELOP IN ITS WAKE && .PRELIMINARY POINT TEMPS/POPS... KLCH 83 60 83 64 / 30 0 10 10 KBPT 84 60 81 64 / 30 0 10 10 KAEX 79 55 81 58 / 10 0 10 10 KLFT 81 59 82 61 / 50 0 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 459 AM CDT FRI MAY 2 2008 .DISCUSSION... A SHARP COLD FRONT CONTINUES TO MAKE ITS WAY ACROSS CENTRAL AND EASTERN OK THIS MORNING...AND IS EXPECTED TO ENTER MCCURTAIN AND RED RIVER COUNTIES BY AROUND 9 AM. THE TIGHT PRESSURE GRADIENT ACROSS THE REGION...ASSOCIATED WITH THE LOW PRESSURE SYSTEM TO THE NORTH...CONTINUES TO KEEP SURFACE WINDS GUSTING AROUND 25 MPH...ESPECIALLY ACROSS EASTERN TEXAS. WINDS WILL PICK UP AGAIN AREAWIDE AFTER SUNRISE...AND WITH THAT HAVE DECIDED TO ISSUE A LAKE WIND ADVISORY THROUGH THE AFTERNOON. BUT THE MAIN CHALLENGE FOR LATER THIS MORNING WILL BE THE THUNDERSTORM DEVELOPMENT ALONG THE FRONT. CURRENTLY...MUCH OF THE FOUR STATE REGION IS UNDER THE INFLUENCE OF A CAPPING INVERSION...WHICH HAS PREVENTED CONVECTION FROM BEING SUSTAINED ALONG THE RED RIVER VALLEY AS INDICATED BY RADAR. HOWEVER...RUC MODEL DATA INDICATES THAT THIS CAP WILL ERODE QUICKLY DURING THE LATE MORNING...WHICH IS EXPECTED TO LEAD TO MORE WIDESPREAD CONVECTION FOR THE WESTERN HALF OF THE REGION DURING THE AFTERNOON. SATELLITE IMAGERY INDICATED LITTLE UPPER CLOUD COVER THIS MORNING TO PREVENT SURFACE HEATING...AND WITH CAPES IN EXCESS OF 2000J/KG AHEAD OF THE FRONT...EXPECT SOME THUNDERSTORMS TO BE SEVERE DURING THE AFTERNOON AND EVENING WITH LARGE HAIL AND DAMAGING WINDS...MAINLY FROM INTERSTATE 20 NORTHWARD TO THE EAST OF LONGVIEW TEXAS. /18/ && .AVIATION... MVFR CONDITIONS ARE BEING OBSERVED THIS MORNING...AS CEILINGS ARE RUNNING BETWEEN 1500 AND 2000 FT. THIS TREND WILL CONTINUE THROUGH THE REST OF THE MORNING...AS LOW LEVEL MOISTURE WILL REMAIN IN ABUNDANCE TODAY. MODELS ARE AGGRESSIVELY PROGRESSING A FRONT TOWARD THE AREA THIS MORNING...AND WITH DECENT MOISTURE...AND INSTABILITY TEMPO TSRA MAY HAVE TO BE MENTIONED IN THE FIRST 6 HRS OF MY 12Z TAFS...FOR TXK...TYR...AND POSSIBLY GGG. A STRONG CAP REMAINS IN PLACE ACROSS THE AREA...SO WE WILL DETERMINE THE TSRA THREAT ON THE DEVELOPMENT OF THE SOUTHERN EXTENT OF THE SQUALL LINE CURRENTLY MOVING ACROSS OK. AN ACTIVE AFTERNOON AND EVENING IS EXPECTED TO BE ON TAP...AS AN APPROACHING 850 MB TROUGH SHOULD HELP ERODE THE CAP. THE MODELS STALL THE FRONT ONCE IT MOVES INTO THE CWA...LEAVING THE POTENTIAL FOR TSRA THROUGH THE END OF THE 12Z TAF PERIOD. TSRA WILL REMAIN THE MAIN THREAT FOR AVIATION INTEREST TODAY...BUT MVFR TO VFR FLIGHT CONDITIONS WILL BE COMMON WITH GUSTY SOUTHERLY WINDS. /11/ && .PRELIMINARY POINT TEMPS/POPS... SHV 80 59 76 53 / 70 60 10 0 MLU 83 63 76 54 / 70 80 20 0 DEQ 77 50 71 43 / 60 10 10 0 TXK 78 55 69 49 / 50 20 10 0 ELD 80 57 73 49 / 70 60 10 0 TYR 81 56 73 52 / 40 10 10 0 GGG 80 57 74 52 / 50 30 10 0 LFK 84 64 80 56 / 40 70 20 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...LAKE WIND ADVISORY UNTIL 4 PM FRIDAY FOR THE FOLLOWING ZONES: COLUMBIA...HEMPSTEAD...HOWARD...LAFAYETTE...LITTLE RIVER...MILLER...NEVADA...SEVIER...AND UNION AR. LA...LAKE WIND ADVISORY UNTIL 4 PM FRIDAY FOR THE FOLLOWING ZONES: BIENVILLE...BOSSIER...CADDO...CALDWELL...CLAIBORNE...DE SOTO...GRANT...JACKSON...LA SALLE...LINCOLN...NATCHITOCHES...OUACHITA...RED RIVER...SABINE LA...UNION LA...WEBSTER...AND WINN. OK...LAKE WIND ADVISORY UNTIL 4 PM FRIDAY FOR THE FOLLOWING ZONES: AND MCCURTAIN. TX...LAKE WIND ADVISORY UNTIL 4 PM FRIDAY FOR THE FOLLOWING ZONES: ANGELINA...BOWIE...CAMP...CASS...CHEROKEE...FRANKLIN...GREGG...HARRISON...M RIVER...RUSK...SABINE TX...SAN AUGUSTINE...SHELBY...SMITH...TITUS...UPSHUR...AND WOOD. && $$ 18/11 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 534 AM EDT SAT MAY 3 2008 .SYNOPSIS... STRONG HIGH PRESSURE EXTENDING FROM EASTERN QUEBEC PROVINCE ACROSS THE STATE WILL SLOWLY MOVE TO THE EAST TODAY. LOW PRESSURE DEVELOPING ACROSS SOUTHERN NEW ENGLAND WILL BRING INCREASING RAIN CHANCES LATER SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... FOG AND LOW CLOUDS HAVE DEVELOPED IN NORTHERN AND EASTERN PORTION OF THE FORECAST AREA. WILL INCLUDE MOSTLY CLOUDY WITH LOCALLY DENSE FOG INTO THESE AREAS THIS MORNING BECOMING MOSTLY SUNNY LATER IN MORNING. STRONG HIGH PRESSURE EXTENDS FROM THE EASTERN PORTION OF QUEBEC PROVINCE ACROSS THE FORECAST AREA. EXPECT THIS SYSTEM TO SLOWLY MOVE TO THE EAST AS LOW PRESSURE APPROACHES FROM WEST. HAVE BEEN WATCHING LINE OF CLOUDS AND SHOWERS OVER THE EASTERN PORTION OF NEW BRUNSWICK. CONCERN EARLY WAS THAT THIS SYSTEM WOULD MOVE INTO THE EASTERN PORTION OF THE FORECAST AREA...HOWEVER OBSERVATIONS CONTINUE TO SHOW LITTLE PROGRESS TO THE WEST. PRIMARY FORECASTING ISSUE IS ARRIVAL OF CLOUDS AND PRECIPITATION FROM LOW PRESSURE APPROACHING FROM THE WEST LATE TONIGHT OR EARLY SUNDAY. OVER LAST SEVERAL RUNS THE NAM HAS BEEN MUCH SLOWER THAN THE GFS WITH THIS SYSTEM...SO HAVE USED AN 80/20 NAM12/GFS40 BLEND TO MOVE CLOUDS/POPS IN SUNDAY. FOR WIND HAVE USED GMOS. PREVIOUS TEMPERATURE AND DEW POINT FORECAST FOR LATER TODAY AND TONIGHT STILL LOOKS REASONABLE SO HAVE NOT MADE ANY CHANGES. WILL CONTINUE TO UPDATE AND MESH CURRENT OBSERVATIONS WITH FORECAST. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... HIGH PRESSURE WILL MOVE TO THE EAST SUNDAY...WHILE A FRONTAL BOUNDARY APPROACHES FROM THE WEST AND LOW PRESSURE DEVELOPS ALONG THE SOUTHERN NEW ENGLAND COAST. CLOUD COVER WILL INCREASE ACROSS THE REGION EARLY SUNDAY...WITH INCREASING CHANCES OF RAIN DURING THE AFTERNOON. THE BEST CHANCE OF RAIN SUNDAY AFTERNOON WILL BE ACROSS DOWNEAST AREAS...NEARER THE SOUTHERN NEW ENGLAND LOW. THE LOW AND FRONTAL BOUNDARY WILL BOTH SLOWLY MOVE EAST SUNDAY NIGHT...WITH THEIR MOVEMENT BEING SLOWED DUE TO BLOCKING HIGH PRESSURE TO THE EAST. THE HEAVIEST PRECIPITATION SUNDAY NIGHT WILL FALL ACROSS DOWNEAST AREAS. THE LOW AND FRONT WILL CONTINUE THEIR SLOW EASTWARD DRIFT MONDAY...KEEPING A CHANCE OF SHOWERS ACROSS THE REGION MOST NUMEROUS ACROSS DOWNEAST AREAS. HIGH PRESSURE BUILDING EAST WILL BRING DECREASING CLOUDINESS ACROSS NORTHERN AREAS MONDAY NIGHT. SHOWERS COULD LINGER DOWNEAST MONDAY EVENING...WITH PARTLY/MOSTLY CLOUDY SKIES OVERNIGHT. HIGH TEMPERATURES SUNDAY WILL RANGE THROUGH THE 50S ACROSS THE REGION. LOW TEMPERATURES SUNDAY NIGHT WILL RANGE FROM AROUND 40 NORTH TO THE LOWER 40S DOWNEAST. HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID TO UPPER 50S ACROSS THE REGION. LOW TEMPERATURES MONDAY NIGHT WILL RANGE FROM THE UPPER 30S TO AROUND 40 NORTH...TO THE LOWER 40S DOWNEAST. && .LONG TERM /TUESDAY THROUGH FRIDAY/... HIGH PRESSURE SHOULD BUILD ACROSS THE REGION TUESDAY...THEN MOVE TO THE EAST WEDNESDAY. UNCERTAINTY THEN EXISTS FOR THURSDAY/FRIDAY REGARDING THE TIMING AND LOCATION OF POSSIBLE LOW PRESSURE WHICH COULD AFFECT THE REGION. FOR NOW...HAVE INCLUDED A CHANCE OF SHOWERS THURSDAY THROUGH EARLY FRIDAY. TEMPERATURES SHOULD BE AT SLIGHTLY ABOVE NORMAL LEVELS TUESDAY/WEDNESDAY...WITH NEAR NORMAL LEVEL TEMPERATURES THURSDAY/FRIDAY. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: IFR/LIFR CONDITIONS ARE POSSIBLE IN SOME AREAS THIS MORNING...THEN VFR CONDITIONS EXPECTED MID MORNING THRU TONIGHT. SHORT TERM: VFR CONDITIONS ARE EXPECTED EARLY SUNDAY...WITH LOWERING CEILINGS/VISIBILITIES SUNDAY AFTERNOON IN DEVELOPING RAIN. REDUCED CEILINGS/VISIBILITIES WILL THEN PERSIST ACROSS THE REGION SUNDAY NIGHT THROUGH EARLY MONDAY...WITH IFR TO LIFR CONDITIONS. CONDITIONS WILL THEN BEGIN TO IMPROVE LATER MONDAY. HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE REGION TUESDAY THEN MOVE TO THE EAST WEDNESDAY. && .MARINE... NEAR TERM: FOR WINDS HAVE USED RUC13 FOR FIRST 12 HOURS THEN TRANSITION TO A 50/50 BLEND OF THE NAM12 AND GFS40. HAVE NOT MADE ANY MODIFICATIONS TO MODEL WIND GUIDANCE. FOR WAVES: HAVE INITIALIZED WITH WNA. COMBINED SEAS RUNNING AROUND 1 FOOT MOSTLY LONG PERIOD WAVE GROUP FROM OUTSIDE LOCAL WATERS. HAVE NOT MADE ANY CHANGES TO WNA. SHORT TERM: WINDS/SEAS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY. SMALL CRAFT ADVISORY LEVEL SEAS ARE THEN POSSIBLE SUNDAY NIGHT INTO MONDAY NIGHT. WINDS/SEAS ARE THEN EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS TUESDAY/WEDNESDAY. VISIBILITIES WILL BE REDUCED IN RAIN AND SHOWERS FROM SUNDAY AFTERNOON THROUGH MONDAY EVENING. && .HYDROLOGY... HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH EARLY SUNDAY...WITH INCREASING RAIN CHANCES LATER SUNDAY. THE BEST CHANCES OF RAIN LATER SUNDAY THROUGH SUNDAY NIGHT WILL BE ACROSS DOWNEAST AREAS. RIVERS AND STREAMS WILL CONTINUE TO RECEDE THROUGH MUCH OF SUNDAY...THOUGH THIS COULD BE SLOWED LATER SUNDAY THROUGH SUNDAY NIGHT DUE TO THE ADDITIONAL RAIN PARTICULARLY ACROSS DOWNEAST AREAS. PLEASE REFER TO FLOOD STATEMENTS FOR DETAILS OF FLOODING ON SPECIFIC RIVERS ACROSS NORTHERN AND CENTRAL MAINE. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...MIGNONE SHORT TERM...NORCROSS LONG TERM...NORCROSS AVIATION...MIGNONE MARINE...MIGNONE/NORCROSS HYDROLOGY...MIGNONE me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 845 PM EDT SAT MAY 3 2008 .SYNOPSIS... A COLD FRONT APPROACHES FROM THE WEST OVERNIGHT...THEN MOVES OFF THE COAST SUNDAY MORNING. HIGH PRESSURE BUILDS OVER THE REGION FOR SUNDAY NIGHT THROUGH MIDWEEK. && .NEAR TERM /THROUGH SUNDAY/... MID-EVENING ANALYSIS DEPICTS SFC COLD FRONT EXTENDING FROM THE EASTERN GRT LKS RGN SOUTH INTO THE CENTRAL GOM. FARTHER WEST...A BROAD AREA OF SFC HIGH PRESSURE WAS NOTED ACRS THE PLAINS. APART FROM MORE SUBSTANTIAL PRECIPITATION WELL TO THE NORTH ALONG THE SFC WARM FRNT BNDRY...PRECIPITATION UPSTREAM ASSOCIATED WITH THE PREFRNTAL TROF IS LOOKING RATHER SPARSE ATTM. LATEST RUC/WRF ONLY BOLSTER THOUGHT THAT INHERITED SCT SHRA WORDING WILL SUFFICE THRU MIDNIGHT OVER WESTERN HALF...EXTENDING INTO THE EASTERN HLF AFTER MIDNIGHT. LAPS SOUNDINGS NICELY DEPICTING DEARTH OF ATMOSPHERIC INSTABILITY THIS EVENING. GFS AND RUC BOTH SHOW CAPE RISING BACK INTO 300-600 J/KG RANGE AFTER MIDNIGHT ACROSS THE FAR SE CWA (WITH MARGINALLY UNSTABLE LI)...BUT SHOWS LTL IN THE WAY OF CAPE/LIFT OVER THE REST OF THE AKQ CWA. ACCORDINGLY...WL PULL THUNDER WORDING FOR MOST OF THE AREA AND STICK WITH SCT SHRA WORDING THRU LATE TONIGHT. LOWERED QPF EVEN FURTHER FOR OVERNIGHT...GENERALLY EXPECTING ON THE ORDER OF A TENTH OF AN INCH OR LESS WHERE SHRAS OCCUR. POPS DIMINISH FROM W TO E TOWARDS DAWN AS ACTUAL FRONT APPROACHES. LOWS TONIGHT U50S/L60S. SUNDAY... WL KP LO CHC POPS FOR SE VA/NE NC AS FNT SLOLY EXITS THE CST BY MIDDAY SUNDAY. DRYING FM THE W TAKES OVR DURG COURSE OF DAY...LEADING TO P/MSNY CONDS...W/ HI TEMPS FM THE MID 70S TO LWR 80S. EVEN OXB (WHR LO CLDS HV HUNG MOST OF TDA) WL HV CLRG DUE TO WNW LLVL FLO. CLDNS MAY BE STUBBORN FAR SE CRNR OF FA (XTRM SE VA/CSTL NE NC) INTO MID AFTN HRS. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... SFC HI PRES BUILDS E FM THE MS VLY...AND SETTLES OVR FA SUN NGT THROUGH TUE AFTN/EVE...PRVDG DRY/COMFY CONDS. RETURN FLO FM THE SSW TUE NGT...AND XPCTG AT LEAST SOME HIER LVL CLDNS TO SPRD INTO RGN FM THE WSW. LO TEMPS SUN NGT/MON NGT 40S INLAND/LWR 50S CST.HI TEMPS MON/TUE MNLY 70S INLAND...UPR 60S CST. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... MID WEEK FCST BECOMES A BIT UNCERTAIN AS A SERIES OF S/W`S MOVES E ACROSS THE NRN STATES WITH THE ASSCTD FRNTL BNDRY PARKING ITSELF ACROSS THE MID ATLNTC RGN. MODELS NOW INDCTG FA REMAINS ON WRM SIDE OF BNDRY WITH BERMUDA RIDGE REMAINING IN CONTROL WED. HAVE TAKEN OUT POPS FOR MOST AREAS WED...JUST LEPT A SLGHT CHC ACROSS NRN CNTYS DRNG AFTRN. S/W MOVES E ALLOWING FRNTL BNDRY TO DROP S ACROSS RGN THU...SO WILL CONT CHC POPS THEN. SCND AND MORE POTENT S/W CROSSES RGN FRI CONTG CHC POPS. WILL GO WITH HPC AND BEGIN TO CLR THINGS OUT BY FRI NITE AND SAT AS HIGH PRS BUILDS IN BEHIND DEPARTING S/W. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... WINDS HAVE DIMINISHED ACROSS THE AREA AND EXPECT MAINLY VFR CONDS OVERNIGHT EVEN WITH FRNT. SLGHT CHC (25) FOR SHRAS ACROSS NRN AND SRN PORTIONS OF AREA WITH SPLIT AREAS OF PRECIP. ONLY MENTION IN TAFS IS FOR SBY...ECG MAY SEE SOME SHRAS AFTER 07Z. MVFR CONDS IN ANY HEAVIER SHRAS IF THEY DEVELOP. OTHRWISE...VFR CONDS WILL CONTINUE SUN THRU WED...AS HI PRES BLDS INTO THE REGION THEN OFF THE CST. A BACKDOOR FRNT CUD AFFECT THE AREA WITH SOME LWR CIGS AND VSBYS ON THU. && .MARINE... WILL DROP SCA WITH 7 PM UPDATE AS GUSTY WNDS SUBSIDE BLO 20 KT. BKDR BNDRY REARED IT UGLY HEAD FOR A FEW HRS ACROSS MD CSTL WTRS AS A WND SHFT INTO E AND NE BROUGHT IN AN AREA OF FOG THAT WAS LURKING OFFSHORE. THE FOG HAS SINCE DSPTD AS BNDRY HAS DRIFTED BACK N AS A WRM FRNT. CRNT WNDS AT BUOY 44009 NOW SE. WILL STILL KEEP SCA FOR NRN CSTL WTRS LATER TONIGHT...BUT AGAIN THIS SHUD BE A MARGINAL EVENT WITH ANY 5 FOOTERS REMAINING WELL OFFSHORE (IVOF 20 NM LIMIT). CDFRNT MOVES ACROSS MARINE AREA LATE SUN SHFTG WNDS INTO A MORE NRLY DRCTN. LTST DATA SUGGESTS THAT WNDS MAY APPRCH SCA IN THE CHES BAY ON MON...BUT WILL CAP AT 15 KTS FOR NOW. LATER SHFTS CAN HOIST SCA HEADLINES ON MON IF NEEDED. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ650-652. && $$ SYNOPSIS...ALB/MAM NEAR TERM...ALB/MAM SHORT TERM...ALB LONG TERM...MPR AVIATION...TMG/BAJ MARINE...MPR md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 130 PM EDT SAT MAY 3 2008 UPDATED FOR 18Z TAF ISSUANCE .DISCUSSION... MAIN FCST CONCERNS ARE PCPN TRENDS/TYPE TODAY AND NEXT ROUND OF PCPN CHANCES SUN THROUGH MON. WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH OVER CNTRL NOAM WITH MID/UPPER LEVEL LOWS ON THE WEST SIDE OF HUDSON BAY AND OVER NE IA. A PROMINENT DRY SLOT WITH THE AXIS OF THE 250-300 MB JET EXTENDED FROM IL AND SE WI INTO CNTRL/ERN UPPER MI. AT THE SFC...A TROUGH EXTENDED FROM CNTRL LAKE SUPERIOR INTO SW IA. RADARS SHOWED A BAND OF RAIN FROM NE MN AND WRN LAKE SUPERIOR THROUGH NW WI INTO ERN MN ASSOCIATED WITH AN AREA OF 700-500 MB DEFORMATION/FGEN. PATCHY LIGHT RAIN WAS ALSO NOTED VCNTY KLNL AND BRUCE CROSSING. SO FAR...ONLY MIX WITH SNOW WAS OBSERVED AT KDLH BTWN 03Z-06Z AND AT 0730Z AT KHYR WHEN THE HEAVIER PCPN BAND MOVED THROUGH. TODAY...MDLS ARE CONSISTENT IN OPENING UP THE SW WI MID LEVEL LOW AND LIFTING IT TO THE NE AS THE NRN LOW WOBBLES INTO NW ONTARIO. ALTHOUGH THE STRONGEST 700-500 MB DEF/FGEN WAS LIFTING NNE INTO NRN ONTARIO...PER 00Z NAM/GFS...A TRAILING BAND OF DEF/FGEN WITH THE COLD CONVEYOR IS EXPECTED TO MOVE THROUGH THE WEST HALF UPPER MI THIS MORNING AND INTO THE EAST THIS AFTERNOON AS IT CONTINUES TO WEAKEN. RADAR TRENDS SUGGEST THAT THE 00Z NAM WAS A BIT TOO FAR EAST AND AGGRESSIVE WITH PCPN AMOUNTS OVER THE FAR WEST. MDL SOUNDINGS...QPF AND FCST WET-BULB ZERO HEIGHTS ALSO SUGGESTED THAT THE LOWER LEVELS WOULD COOL ENOUGH FOR THE RAIN TO CHANGE OVER TO SNOW WITH SEVERAL INCHES POSSIBLE OVER HIGHER TERRAIN. HOWEVER...SINCE THE PCPN BAND...FORCING AND ASSOCIATED DYNAMIC COOLING HAVE BEEN WEAKER...EXPECT ONLY A MIX OR OCNL CHANGE OVER TO SNOW AND LITTLE ACCUMULATION (LESS THAN AN INCH). OTHERWISE...AREA OF LIGHT RAIN ARE EXPECTED. AREAS OF FOG EARLY OVER THE EAST HALF WILL ALSO QUICKLY DISSIPATE AS WINDS VEER TO THE NW AS THE SFC TROUGH MOVES THROUGH. TONIGHT...ANY LEFTOVER PCPN OVER THE ERN PORTION OF THE CWA SHOULD END EARLY AND CLEARING WILL MOVE IN AS QVECTOR DIV AND SFC RIDING MOVE IN ALONG WITH SIGNIFICANT DRY ADVECTION. SUN AND SUN NIGHT...THE GLOBAL MODELS ALONG WITH THE NAM AGREE THAT A SHORTWAVE TROUGH WILL PIVOT AROUND THE VORTEX OVER NW ONTARIO BRINGING THE POTENTIAL FOR ANOTHER ROUND OF PCPN. MODELS TRENDS HAVE BEEN TOWARD A QUICKER MOVEMENT WITH THIS SYSTEM WITH THE BEST PCPN CHANCES INTO THE CWA SUN AFTERNOON INTO SUN EVENING. ALTHOUGH MODERATE QVECTOR CONV AND UPPER LEVEL DIV WITH THE LEFT EXIT OF AN UPPER LEVEL JET STREAK WILL BE CAPABLE OF SQUEEZING OUT PCPN WITH LITTLE ADDITIONAL INFLOW...GIVEN RECENT MODELS VARIABILITY AND UNCERTAINTY WHERE THE MAIN BAND OF PCPN WILL SET UP...THE FCST INCLUDES ONLY LOWER END POPS. MON INTO TUE...UPPER MI REMAINS NEAR THE MAIN BAROCLINIC ZONE AND FAST WRLY FLOW SOUTH OF THE PERSISTENT VORTEX NEAR THE SW END OF HUDSON BAY. SO...POTENTIAL REMAINS FOR SHORTWAVES WITH AREAS OF PCPN TO MOVE THROUGH THE REGION. CONFIDENCE IN THE TIMING AND POSITION OF THESE FEATURES REMAINS LOW GIVEN CONTINUED LARGE VARIATION BTWN MODELS AND LAKC OF RUN TO RUN CONSISTENCY. SO...ADDITIONAL PCPN CHANCES MAY BE NEEDED FOR TUE BUT WERE NOT ADDED YET. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... CONDITIONS WILL CONTINUE TO IMPROVE AS PCPN MOVES OUT WITH IFR CONDITIONS AT KCMX EARLY THIS AFTERNOON RAPIDLY GOING TO MVFR AND THEN VFR BY THIS EVENING. KSAW WILL GO FROM MVFR TO VFR THIS EVENING. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... FUNNELING NE WINDS OVER THE WESTERN THIRD OF LS WILL WEAKEN AS WINDS SHIFT AROUND THE EXITING SURFACE LOW...SHIFTING NORTH OF LS BY EARLY AFTERNOON. THIS WILL GIVE AN OPPORTUNITY FOR NEAR GALE FORCE WINDS OVER THE EASTERN THIRD OF THE LAKE. HOWEVER...WITH THE QUICKLY MOVING LOW GALE FORCE WIND GUSTS SHOULD BE TRANSIENT IN NATURE. OTHERWISE...WINDS AT OR BELOW 20KT ARE FIGURED. A LOW CONFIDENCE FORECAST IS IN STORE FOR THE END OF THE PERIOD...WITH THE NEXT SIGNIFICANT LOW PRESSURE SYSTEM MOVING IN FROM THE CENTRAL/NORTHERN PLAINS TUESDAY AND WEDNESDAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...JLB AVIATION...GM MARINE...KF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 705 AM EDT SAT MAY 3 2008 UPDATED FOR 12Z TAF ISSUANCE .DISCUSSION... MAIN FCST CONCERNS ARE PCPN TRENDS/TYPE TODAY AND NEXT ROUND OF PCPN CHANCES SUN THROUGH MON. WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH OVER CNTRL NOAM WITH MID/UPPER LEVEL LOWS ON THE WEST SIDE OF HUDSON BAY AND OVER NE IA. A PROMINENT DRY SLOT WITH THE AXIS OF THE 250-300 MB JET EXTENDED FROM IL AND SE WI INTO CNTRL/ERN UPPER MI. AT THE SFC...A TROUGH EXTENDED FROM CNTRL LAKE SUPERIOR INTO SW IA. RADARS SHOWED A BAND OF RAIN FROM NE MN AND WRN LAKE SUPERIOR THROUGH NW WI INTO ERN MN ASSOCIATED WITH AN AREA OF 700-500 MB DEFORMATION/FGEN. PATCHY LIGHT RAIN WAS ALSO NOTED VCNTY KLNL AND BRUCE CROSSING. SO FAR...ONLY MIX WITH SNOW WAS OBSERVED AT KDLH BTWN 03Z-06Z AND AT 0730Z AT KHYR WHEN THE HEAVIER PCPN BAND MOVED THROUGH. TODAY...MDLS ARE CONSISTENT IN OPENING UP THE SW WI MID LEVEL LOW AND LIFTING IT TO THE NE AS THE NRN LOW WOBBLES INTO NW ONTARIO. ALTHOUGH THE STRONGEST 700-500 MB DEF/FGEN WAS LIFTING NNE INTO NRN ONTARIO...PER 00Z NAM/GFS...A TRAILING BAND OF DEF/FGEN WITH THE COLD CONVEYOR IS EXPECTED TO MOVE THROUGH THE WEST HALF UPPER MI THIS MORNING AND INTO THE EAST THIS AFTERNOON AS IT CONTINUES TO WEAKEN. RADAR TRENDS SUGGEST THAT THE 00Z NAM WAS A BIT TOO FAR EAST AND AGGRESSIVE WITH PCPN AMOUNTS OVER THE FAR WEST. MDL SOUNDINGS...QPF AND FCST WET-BULB ZERO HEIGHTS ALSO SUGGESTED THAT THE LOWER LEVELS WOULD COOL ENOUGH FOR THE RAIN TO CHANGE OVER TO SNOW WITH SEVERAL INCHES POSSIBLE OVER HIGHER TERRAIN. HOWEVER...SINCE THE PCPN BAND...FORCING AND ASSOCIATED DYNAMIC COOLING HAVE BEEN WEAKER...EXPECT ONLY A MIX OR OCNL CHANGE OVER TO SNOW AND LITTLE ACCUMULATION (LESS THAN AN INCH). OTHERWISE...AREA OF LIGHT RAIN ARE EXPECTED. AREAS OF FOG EARLY OVER THE EAST HALF WILL ALSO QUICKLY DISSIPATE AS WINDS VEER TO THE NW AS THE SFC TROUGH MOVES THROUGH. TONIGHT...ANY LEFTOVER PCPN OVER THE ERN PORTION OF THE CWA SHOULD END EARLY AND CLEARING WILL MOVE IN AS QVECTOR DIV AND SFC RIDING MOVE IN ALONG WITH SIGNIFICANT DRY ADVECTION. SUN AND SUN NIGHT...THE GLOBAL MODELS ALONG WITH THE NAM AGREE THAT A SHORTWAVE TROUGH WILL PIVOT AROUND THE VORTEX OVER NW ONTARIO BRINGING THE POTENTIAL FOR ANOTHER ROUND OF PCPN. MODELS TRENDS HAVE BEEN TOWARD A QUICKER MOVEMENT WITH THIS SYSTEM WITH THE BEST PCPN CHANCES INTO THE CWA SUN AFTERNOON INTO SUN EVENING. ALTHOUGH MODERATE QVECTOR CONV AND UPPER LEVEL DIV WITH THE LEFT EXIT OF AN UPPER LEVEL JET STREAK WILL BE CAPABLE OF SQUEEZING OUT PCPN WITH LITTLE ADDITIONAL INFLOW...GIVEN RECENT MODELS VARIABILITY AND UNCERTAINTY WHERE THE MAIN BAND OF PCPN WILL SET UP...THE FCST INCLUDES ONLY LOWER END POPS. MON INTO TUE...UPPER MI REMAINS NEAR THE MAIN BAROCLINIC ZONE AND FAST WRLY FLOW SOUTH OF THE PERSISTENT VORTEX NEAR THE SW END OF HUDSON BAY. SO...POTENTIAL REMAINS FOR SHORTWAVES WITH AREAS OF PCPN TO MOVE THROUGH THE REGION. CONFIDENCE IN THE TIMING AND POSITION OF THESE FEATURES REMAINS LOW GIVEN CONTINUED LARGE VARIATION BTWN MODELS AND LAKC OF RUN TO RUN CONSISTENCY. SO...ADDITIONAL PCPN CHANCES MAY BE NEEDED FOR TUE BUT WERE NOT ADDED YET. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... VIS AND CEIGS ARE SLOWLY REBOUNDING...AT LEAST TEMPORARILY AS ADDITIONAL RAIN AND SNOW SHOWERS ROTATE IN FROM THE WEST...AND THE MAIN SFC LOW SHIFTS NORTH OF SAW. CEIGS AT CMX SHOULD REMAIN IN THE IFR CATEGORY WITH UPSLOPE WIND DIRECTION TODAY...AND THE POTENTIAL FOR SHRASN AFTER 14Z. DRIER AIR WILL SLIDE IN LATE IN THE PERIOD...WITH SCT CLOUDS AND LIGHTER WINDS. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... FUNNELING NE WINDS OVER THE WESTERN THIRD OF LS WILL WEAKEN AS WINDS SHIFT AROUND THE EXITING SURFACE LOW...SHIFTING NORTH OF LS BY EARLY AFTERNOON. THIS WILL GIVE AN OPPORTUNITY FOR NEAR GALE FORCE WINDS OVER THE EASTERN THIRD OF THE LAKE. HOWEVER...WITH THE QUICKLY MOVING LOW GALE FORCE WIND GUSTS SHOULD BE TRANSIENT IN NATURE. OTHERWISE...WINDS AT OR BELOW 20KT ARE FIGURED. A LOW CONFIDENCE FORECAST IS IN STORE FOR THE END OF THE PERIOD...WITH THE NEXT SIGNIFICANT LOW PRESSURE SYSTEM MOVING IN FROM THE CENTRAL/NORTHERN PLAINS TUESDAY AND WEDNESDAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...JLB AVIATION...KF MARINE...KF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 445 AM EDT SAT MAY 3 2008 .DISCUSSION... MAIN FCST CONCERNS ARE PCPN TRENDS/TYPE TODAY AND NEXT ROUND OF PCPN CHANCES SUN THROUGH MON. WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH OVER CNTRL NOAM WITH MID/UPPER LEVEL LOWS ON THE WEST SIDE OF HUDSON BAY AND OVER NE IA. A PROMINENT DRY SLOT WITH THE AXIS OF THE 250-300 MB JET EXTENDED FROM IL AND SE WI INTO CNTRL/ERN UPPER MI. AT THE SFC...A TROUGH EXTENDED FROM CNTRL LAKE SUPERIOR INTO SW IA. RADARS SHOWED A BAND OF RAIN FROM NE MN AND WRN LAKE SUPERIOR THROUGH NW WI INTO ERN MN ASSOCIATED WITH AN AREA OF 700-500 MB DEFORMATION/FGEN. PATCHY LIGHT RAIN WAS ALSO NOTED VCNTY KLNL AND BRUCE CROSSING. SO FAR...ONLY MIX WITH SNOW WAS OBSERVED AT KDLH BTWN 03Z-06Z AND AT 0730Z AT KHYR WHEN THE HEAVIER PCPN BAND MOVED THROUGH. TODAY...MDLS ARE CONSISTENT IN OPENING UP THE SW WI MID LEVEL LOW AND LIFTING IT TO THE NE AS THE NRN LOW WOBBLES INTO NW ONTARIO. ALTHOUGH THE STRONGEST 700-500 MB DEF/FGEN WAS LIFTING NNE INTO NRN ONTARIO...PER 00Z NAM/GFS...A TRAILING BAND OF DEF/FGEN WITH THE COLD CONVEYOR IS EXPECTED TO MOVE THROUGH THE WEST HALF UPPER MI THIS MORNING AND INTO THE EAST THIS AFTERNOON AS IT CONTINUES TO WEAKEN. RADAR TRENDS SUGGEST THAT THE 00Z NAM WAS A BIT TOO FAR EAST AND AGGRESSIVE WITH PCPN AMOUNTS OVER THE FAR WEST. MDL SOUNDINGS...QPF AND FCST WET-BULB ZERO HEIGHTS ALSO SUGGESTED THAT THE LOWER LEVELS WOULD COOL ENOUGH FOR THE RAIN TO CHANGE OVER TO SNOW WITH SEVERAL INCHES POSSIBLE OVER HIGHER TERRAIN. HOWEVER...SINCE THE PCPN BAND...FORCING AND ASSOCIATED DYNAMIC COOLING HAVE BEEN WEAKER...EXPECT ONLY A MIX OR OCNL CHANGE OVER TO SNOW AND LITTLE ACCUMULATION (LESS THAN AN INCH). OTHERWISE...AREA OF LIGHT RAIN ARE EXPECTED. AREAS OF FOG EARLY OVER THE EAST HALF WILL ALSO QUICKLY DISSIPATE AS WINDS VEER TO THE NW AS THE SFC TROUGH MOVES THROUGH. TONIGHT...ANY LEFTOVER PCPN OVER THE ERN PORTION OF THE CWA SHOULD END EARLY AND CLEARING WILL MOVE IN AS QVECTOR DIV AND SFC RIDING MOVE IN ALONG WITH SIGNIFICANT DRY ADVECTION. SUN AND SUN NIGHT...THE GLOBAL MODELS ALONG WITH THE NAM AGREE THAT A SHORTWAVE TROUGH WILL PIVOT AROUND THE VORTEX OVER NW ONTARIO BRINGING THE POTENTIAL FOR ANOTHER ROUND OF PCPN. MODELS TRENDS HAVE BEEN TOWARD A QUICKER MOVEMENT WITH THIS SYSTEM WITH THE BEST PCPN CHANCES INTO THE CWA SUN AFTERNOON INTO SUN EVENING. ALTHOUGH MODERATE QVECTOR CONV AND UPPER LEVEL DIV WITH THE LEFT EXIT OF AN UPPER LEVEL JET STREAK WILL BE CAPABLE OF SQUEEZING OUT PCPN WITH LITTLE ADDITIONAL INFLOW...GIVEN RECENT MODELS VARIABILITY AND UNCERTAINTY WHERE THE MAIN BAND OF PCPN WILL SET UP...THE FCST INCLUDES ONLY LOWER END POPS. MON INTO TUE...UPPER MI REMAINS NEAR THE MAIN BAROCLINIC ZONE AND FAST WRLY FLOW SOUTH OF THE PERSISTENT VORTEX NEAR THE SW END OF HUDSON BAY. SO...POTENTIAL REMAINS FOR SHORTWAVES WITH AREAS OF PCPN TO MOVE THROUGH THE REGION. CONFIDENCE IN THE TIMING AND POSITION OF THESE FEATURES REMAINS LOW GIVEN CONTINUED LARGE VARIATION BTWN MODELS AND LAKC OF RUN TO RUN CONSISTENCY. SO...ADDITIONAL PCPN CHANCES MAY BE NEEDED FOR TUE BUT WERE NOT ADDED YET. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... EXPECT PREDOMINANT IFR/LIFR CONDITIONS INTO THE EARLY MRNG HRS WITH LINGERING SHOWERS AT CMX/FOG IN MOIST SSE FLOW AHEAD OF APRCHG LO PRES FM WRN WI AND ATTENDANT WARM FNT. ONCE THE LO SHIFTS INTO LK SUP EARLY THIS MRNG AND THE WARM FNT PASSES SAW...EXPECT IMPROVING CONDITIONS THERE. BUT CMX WL BE ON THE COOL SIDE OF THE LO TRACK... SO NO IMPROVEMENT IS LIKELY THERE UNTIL SUNRISE WHEN THE INCRSG NW FLOW IN THE WAKE OF THE LO IMPROVES VSBY THERE. BUT CIGS SHOULD REMAIN IN THE IFR CATEGORY WITH UPSLOPE WIND DIRECTION. MORE SHRASN/LOWER VSBYS WL ARRIVE THIS MRNG WITH BACKWASH MSTR/COLDER AIRMASS. DOWNSLOPING NW WIND WL LIMIT THE IMPACT AT SAW WHEN THIS DEEPER MSTR MOVES IN BY EARLY AFTN. PUSH OF DRIER AIR INTO THE UPR LKS WL ALLOW CONDITIONS TO IMPROVE TO VFR LATE IN THE DAY. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... FUNNELING NE WINDS OVER THE WESTERN THIRD OF LS WILL WEAKEN AS WINDS SHIFT AROUND THE EXITING SURFACE LOW...SHIFTING NORTH OF LS BY EARLY AFTERNOON. THIS WILL GIVE AN OPPORTUNITY FOR NEAR GALE FORCE WINDS OVER THE EASTERN THIRD OF THE LAKE. HOWEVER...WITH THE QUICKLY MOVING LOW GALE FORCE WIND GUSTS SHOULD BE TRANSIENT IN NATURE. OTHERWISE...WINDS AT OR BELOW 20KT ARE FIGURED. A LOW CONFIDENCE FORECAST IS IN STORE FOR THE END OF THE PERIOD...WITH THE NEXT SIGNIFICANT LOW PRESSURE SYSTEM MOVING IN FROM THE CENTRAL/NORTHERN PLAINS TUESDAY AND WEDNESDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...FLOOD ADVY UNTIL EARLY SAT MRNG FOR MIZ002-003-009-084. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ DISCUSSION...JLB AVIATION...KC MARINE...KF mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 115 PM EDT FRI MAY 2 2008 .DISCUSSION... MAIN FCST CONCERNS ARE PCPN TRENDS/TYPE THROUGH SATURDAY. WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL LOWS OVER THE SW END OF HUDSON BAY AND OVER WRN NEB AND A RIDGE OVER THE SE CONUS LEAVING UPPER MI NEAR A CONFLUENT ZONE BTWN THESE FEATURES. AT THE SFC...LOW PRES WAS LOCATED OVER CNTRL SD WITH A WARM FRONT TO THE SE INTO NRN IL. A BAND OF TSRA FROM NW TO S CNTRL WI WITH INNSTABILITY AND ISENTROPIC LIFT JUST NORTH OF THE 850 MB WARM FRONT. FARTHER NORTH ANOTHER BAND OF PCPN FROM W UPPER MI TO NRN LOWER MI WAS SUPPORTED BY 800-600 MB FGEN/DEFORMATION. TODAY AND TONIGHT... MODELS WERE IN DECENT OVERALL AGREEMENT IN THE SHORT TERM. SO HAVE GENERALLY USED A BLEND OF THE 00Z NAM/GFS AND LCL HIGH RES WRF/ARW. EXPECT THE BAND OF 800-600 MB FGEN/DEF NORTH OF THE 850 MB WARM FRONT TO SLOWLY LIFT TO THE NORTH THIS MORNING WITH A PERIOD OF LIGHT RAIN ACROSS THE CWA WHICH SHOULD TAPER OFF BTWN 15Z-18Z. EVEN THERE MAY BE A LULL IN THE PCPN BY MIDDAY OR DURING THE AFTERNOON...WITH LINGERING 295K-300K ISENTROPIC LIFT AND THE POSSIBILITY OF ADDITIONAL PCPN DEVELOPING AHEAD OF THE NEXT MAIN PCPN BAND...LIKEL CONTINUE...AS IN THE PREVIOUS FCST. BY LATE AFTERNOON...UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 250-300 MB JET OVER NRN ONTARIO ALONG WITH AN AREA OF STRONG 700-500 QVECTOR CONV AHEAD OF THE MID LEVEL LOW MOVING FROM MN TOWARD UPPER MI WILL LEAD TO LARGE SCALE LIFT OVER THE AREA. THE COMBINATION OF LARGE SCALE LIFT...ABUNDANT MOISTURE...850 MB DEWPOINT AROUND 10C... AND ANOTHER BAND OF STRONG 800-600 FGEN/300K-305 ISENTROPIC LIFT WILL BRING ANOTHER AREA OF RAIN THROUGH THE CWA...MAINLY BTWN 21Z-03Z. THE BEST CHANCE FOR SIGNIFICANT RAINFALL AMOUNTS 0.50-1.25 INCH RANGE IS EXPECTED OVER THE WEST HALF. WHILE THE AMOUNT MAY NOT BE TOO EXCESSIVE...IT COULD PUSH SOME RIVER LEVELS BACK NEAR FLOOD STAGE. OVERNIGHT...ANY LINGERING PCPN SHOULD FOCUS OVER THE WEST THIRD...CLOSEST TO THE STRONGEST UPPER LEVEL DIV FROM THE LEFT EXIT OF THE UPPER LEVEL JET AND QVECTOR CONV NEAR THE DEFORMATION AXIS. THE DRY SLOT SHOULD BRING AND END TO MOST OF THE PCPN OVER THE EAST HALF. ALTHOUGH MUCAPE VALUES IN THE 200-400 J/KG RANGE REMAIN MAINLY SOUTH OF UPPER MI THIS AFTERNOON AND EVENING...NEG GFS 850 MB VALUES AND THE STRENGTH OF THE DYNAMICS...ISOLD TSRA STILL POSSIBLE OVER MUCH OR THE CWA. SAT...THE MID LEVEL TROUGH IS EXPECTED TO OPEN UP AND LIFT TO THE ENE AS THE VORTEX OVER CANADA PIVOTS SLOWLY WESTWARD INTO NRN MANITOBA. THE ASSOCIATED AREA OF QVECTOR CONV WILL BRING AN AREA OF LIGHT PCPN THROUGH UPPER MI. CAA BRINGS IN ENOUGH COOLING FOR MIX OR CHANGEOVER TO SNOW FROM WEST TO EAST. WET-BULB ZERO HEIGHTS AND FCST SOUNDINGS SUGGEST A CHANGE TO MAINLY SNOW OVER THE FAR WEST DURING THE MORNING. HOWEVER...QPF AMOUNTS AND THE RELATIVELY WARM GROUND SHOULD LIMIT ANY ACCUMULATIONS IN THE HIGHER TERRAIN TO AN INCH OR LESS. SUN INTO MON...THE 12Z ECMWF AND 00Z GFS SUGGEST PCPN MAY BE POSSIBLE SUN NIGHT AS A SHORTWAVE TROUGH PIVOTS AROUND THE VORTEX LINGERING OVER NRN ONTARIO. WITH ONLY LIMITED MOISTURE AVAILABLE AND UNCERTAINTY WITH TIMING/STRENGTH OF THIS FEATURE...ONLY LOWER END CHANCE POPS WERE INCLUDED. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... IFR/LIFR CONDITIONS WILL CONTINUE THROUGH THE PERIOD WITH RAIN. CONDITIONS WILL IMPROVE ON SATURDAY AS THE LOW CENTER MOVES INTO ONTARIO AND DRY AIR ADVECTS INTO THE AREA. AS THE WIND GOES WEST BY EARLY AFTERNOON AT KSAW...MVFR CONDITIONS WILL TAKE OVER WITH WRAPAROUND MOISTURE AROUND. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... AS LOW PRESSURE LIFTS INTO UPR LAKES NEXT 24 HR AS HIGH PRESSURE RIDGE OVR ONTARIO FADES AWAY. NORTHEAST WIND DIRECTION DOWN WESTERN LAKE SUPERIOR WILL CONTINUE TO SUPPORT OCCASIONAL GALE FORCE GUSTS TODAY. TIGHT PRESSURE GRADIENT ALONG WITH INCREASING WINDS JUST OFF SURFACE RESULT IN MORE FREQUENT GALE FORCE GUST TOWARD THE NEAR DULUTH END OF LAKE SUPERIOR ON TODAY. AS THE LOW PRESSURE SHIFTS AWAY FROM THE UPPER LAKES BY LATE WEEKEND...THE WINDS WILL GRADUALLY DIMINISH AS A RESULT. BEYOND THE NEXT 24 HRS WINDS EXPECTED TO REMAIN BELOW 30 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. UPPER MICHIGAN..NONE. LAKE SUPERIOR... GALE WARNING FROM 10 AM TO 10 PM EDT FRIDAY FOR LSZ162. LAKE MICHIGAN...NONE. && $$ DISCUSSION...JLB AVIATION...GM MARINE...DLG mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 1046 AM CDT SAT MAY 3 2008 .UPDATE...UPPER LOW REALLY PULLING AWAY QUICKLY THIS MORNING. PULLED POPS AND LOWERED CLOUD COVER OVER MUCH THE THE FA. THE EXCEPTION IS ALONG THE EASTERN TIER COUNTIES IN WI INCLUDING IRON AND PRICE. WEB CAM IN HURLEY CONFIRMS KIWD VSBY OF 1SM WITH WET SNOW SHOWERS CONTINUING...LIKELY THROUGH THE NEXT COUPLE HOURS. ALSO RAISED HIGH TEMPS THIS AFTERNOON 2 TO 3 DEGREES DESPITE CAA...WITH GOOD MIXING UNDERWAY AND AMPLE MAY SUNSHINE ACROSS MOST OF THE FA. && .PREV DISCUSSION... /ISSUED 341 AM CDT SAT MAY 3 2008/ DISCUSSION... SFC LOW OVER WRN UP OF MICHIGAN TRACKING NE TOWARDS 5MB/3HR ISALLOBAR OVER CTRL ONTARIO. DEFORMATION AXIS PIVOTING SLOWLY OVER ERN CWA...WHILE TRANSLATING EAST AS WELL. TYPICAL SPRINGTIME SETUP... WITH AREAS OF WET SNOW OCCURRING UNDERNEATH POCKETS OF BEST UVV AND ASSOCIATED DIABATIC COOLING. ONCE UVV WEAKENS...POPTYP REVERTS TO MAINLY LIQUID. SFC TEMPS ACTUALLY RISING NEAR TWIN PORTS JUST WEST OF BACK EDGE OF PRECIP SHIELD. REPORTS FROM COOK CO SHERIFFS OFFICE OF SEVERAL INCHES OF SLUSHY SNOW OVER THE HILL...AWAY FROM MARINE INFLUENCE NEAR LAKE.ANTICIPATE ANOTHER INCH OR SO OF WET SLUSH OVER INTERIOR COOK COUNTY BEFORE BOTH THERMAL/MOISTURE PROFILES BECOME LESS FAVORABLE. SECOND AREA OF SLUSHY ACCUMULATION POSSIBLE OVER INTERIOR NW WISC WHERE RUC13 ANIMATION OF BDRY LYR TEMPERATURES SHOWS A POCKET OF DIABATIC COOLING. SHOULD BE SHORT LIVED HOWEVER AS BETTER UVV PUSHES EAST BY 12Z. BRISK NW WINDS TODAY AS ANY MIXING TAPS INTO UNIDIRECTIONAL SFC/85H FLOW. ANOMALOUS VORTEX OVER NRN MANITOBA WILL SAG SOUTH PER MDL CONSENSUS OVER THE REMAINDER OF THE WEEKEND. SOME DIFFERENCES ON MINOR QPF/POPS...HOWEVER STILL LOOKS LIKE A FEW SHOWERS WILL SKIRT NRN HALF OF CWA SUNDAY/SUNDAY NIGHT. BEYOND THAT...SEVERAL WEAK DISTURBANCES WILL SLIDE QUICKLY ALONG WNW MID LVL FLOW THROUGH TUESDAY. LOW POPS/QPF AS DEEP LAYER MOISTURE WILL BE LACKING. EXTENDED...SLOW MODERATION IN COOL AIR OVER CWA. NO MAJOR SYSTEMS THROUGH FRIDAY AS RATHER WEAK MID LVL FLOW DOMINATES NRN CONUS. AVIATION... CEILINGS SHOULD LIFT TO VFR ALL AREAS BY AFTERNOON...WITH THE EXCEPTION OF THE KPBH AND KIWD AREAS...WHERE MVFR CONDITIONS WILL LINGER. && POINT TEMPS/POPS... DLH 49 29 55 32 / 10 10 20 20 INL 48 28 51 29 / 10 10 30 20 BRD 53 32 60 36 / 10 10 10 10 HYR 52 28 58 35 / 40 10 10 20 ASX 48 29 56 34 / 50 10 20 30 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LSZ121- LSZ146-LSZ147-LSZ148. SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ140- LSZ141-LSZ142-LSZ143-LSZ144-LSZ145. $$ LILES mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 943 AM CDT SAT MAY 3 2008 .DISCUSSION... THE GOING FORECAST LOOKS ON TRACK...WITH DRIER AIR MOVING INTO THE REGION AND THE LAST VESTIGES OF PCPN EXITED THE EAST. VISIBLE IMAGERY SHOWS CLEAR SKIES OVER MOST OF THE CWFA AT THIS TIME....WITH MOST OF THE LINGERING CLOUD COVER CONFINED TO THE WISCONSIN COUNTIES. THE LATEST RUC 925-600MB RH FIELDS HAVE A GOOD HANDLE ON THE CURRENT CLOUD SITUATION...AND THIS WOULD SUGGEST THE SIGNIFICANT CLOUDS SHOULD BE ABLE TO EXIT THE ENTIRE AREA BEFORE 18Z AND THE LINGERING PCPN OVER THE FAR EAST SHOULD BE DONE PRIOR TO THEN GIVEN THE DWINDLING MOISTURE AND DEPARTURE OF DOWNWARD MOTION MOVING IN ON THE BACKSIDE OF THE SHORTWAVE. 12Z SOUNDINGS FROM AROUND THE AREA ARE NOT VERY SUPPORTIVE FOR MUCH IN THE WAY OF DIURNAL CU...BUT WOULD EXPECT TO SEE A LITTLE BIT IN THE LINGERING CYCLONIC BOUNDARY LAYER FLOW UNTIL THE DEWPOINTS ARE ABLE TO MIX OUT. HOWEVER...DO NOT ENVISION ANYTHING MORE THAN PARTLY CLOUDY SKIES AT BEST IN THE CURRENT CLEAR AREA...WHICH LINES UP WELL WITH THE GOING FORECAST. HIGH TEMPERATURES LOOK ON TRACK AS WELL...GENERALLY RANGING FROM THE MID 40S TO MID 50S. MAY BUMP UP EASTERN ZONES SLIGHTLY GIVEN A SLIGHTLY EARLIER DEPARTURE OF THE CLOUD COVER. BREEZY CONDITIONS WILL PERSIST THROUGH THE DAY...ALTHOUGH WINDS HAVE ALREADY DROPPED BELOW ADVISORY CRITERIA...SO THE HEADLINE WAS ALLOWED TO EXPIRE. && .AVIATION.../12Z TAF ISSUANCE ISSUED 707 AM CDT SAT MAY 3 2008/ CLOUDS AND RAIN SHOWERS WILL CONTINUE TO EXIT THE TAF SITES THIS MORNING...WITH VFR CONDITIONS EXPECTED AT ALL TAF SITES BY AROUND 15Z. BRISK NORTHWEST WINDS WILL GRADUALLY DECREASE THIS MORNING...AS THE SURFACE PRESSURE GRADIENT SLACKENS WITH THE EASTWARD MOVEMENT OF THE LOW OVER LAKE SUPERIOR. CLEAR SKIES WILL PREVAIL THIS AFTERNOON AND EVENING...WITH ONLY FLEETING CIRRUS EXPECTED THROUGH THE END OF THE TAF PERIOD. WINDS WILL BACK TO THE SOUTHWEST THIS EVENING...AND DECREASE TO BELOW 10 KNOTS. && .PREV DISCUSSION... /ISSUED 323 AM CDT SAT MAY 3 2008/ UPPER LOW BEGINNING TO SHEAR OUT TOWARD THE NORTHEAST AND CLOUDS HAVE BEEN CLEARING OUT OF W MN. BY 12Z MOST OF THE REMAINING PRECIP WILL BE CONFINED TO OUR WI ZONES AND EVEN THERE RAIN SHOULD BE OVER BY 18Z. NOT SEEING MUCH IN THE WAY OF SNOW IN ANY OF THE OBS SO REMOVED FROM FORECAST. METARS SHOWING WIND ADVISORY TO BE BE MARGINAL EXCEPT IN SW/SC MN WHERE A FEW STATIONS HAVE BEEN SHOWING SUSTAINED WINDS OVER 30 MPH. WDL PROFILER ALSO JUST BEGINNING TO SHOW DECREASING TREND ON WINDS. WILL LET THE ADVISORY EXPIRE AS SCHEDULED AT 0900. INCREASED SPEED OF CLEARING A BIT FOR TODAY WITH MAINLY JUST MID CLOUDS NOW WEST OF A STC TO RWF LINE. WINDS GAIN A BIT MORE OF A WESTERLY COMPONENT BY 18Z AND EVEN MORE SO IN THE AFTERNOON WHICH SHOULD CONTINUE TO MOVE THE CLEARING ALONG. QUITE LOW SURFACE DEWPOINTS ACROSS THE DAKOTAS WHICH WILL PUSH INTO W MN AS WINDS BECOME MORE WEST. SHOULD SEE SOME HUMIDITY VALUES IN THE AFTERNOON IN WC MN IN THE MID 20% RANGE. SURFACE WINDS BECOME MORE SWLY TONIGHT AHEAD OF WEAK COLD FRONT DROPPING INTO N MN. THIS WILL HELP TO MODERATE THE OVERNITE TEMPERATURES A BIT. GFS AND NAM BOTH BRING SMALL PCPN AMOUNTS INTO CENTRAL MN AND N WI SUNDAY AFTERNOON/EVENING AS THE FRONT MOVES THROUGH PUT SOME SLIGHT CHANCE POPS IN SMALL AREA OF EC MN INTO WI FOR THE AFTN AND EVE. A STRONGER WAVE COMES DOWN IN NW FLOW FOR MONDAY SO AGAIN SOME LOW RANGE POPS MAINLY N CWA. DIDN`T MESS MUCH WITH THE POPS WE HAVE IN FOR TUESDAY. GFS SHOWING FAIRLY STRONG FORCING MOVING THRU AREA WITH NAM WEAKER AND FARTHER SOUTH. NO REAL STRONG PUSHES OF COLD AIR NEXT SEVERAL DAYS...BUT NWLY FLOW WILL KEEP TEMPERATURES A BIT BELOW NORMAL. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ TRH/LS/BAP mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 341 AM CDT SAT MAY 3 2008 .DISCUSSION... SFC LOW OVER WRN UP OF MICHIGAN TRACKING NE TOWARDS 5MB/3HR ISALLOBAR OVER CTRL ONTARIO. DEFORMATION AXIS PIVOTING SLOWLY OVER ERN CWA...WHILE TRANSLATING EAST AS WELL. TYPICAL SPRINGTIME SETUP... WITH AREAS OF WET SNOW OCCURRING UNDERNEATH POCKETS OF BEST UVV AND ASSOCIATED DIABATIC COOLING. ONCE UVV WEAKENS...POPTYP REVERTS TO MAINLY LIQUID. SFC TEMPS ACTUALLY RISING NEAR TWIN PORTS JUST WEST OF BACK EDGE OF PRECIP SHIELD. REPORTS FROM COOK CO SHERIFFS OFFICE OF SEVERAL INCHES OF SLUSHY SNOW OVER THE HILL...AWAY FROM MARINE INFLUENCE NEAR LAKE.ANTICIPATE ANOTHER INCH OR SO OF WET SLUSH OVER INTERIOR COOK COUNTY BEFORE BOTH THERMAL/MOISTURE PROFILES BECOME LESS FAVORABLE. SECOND AREA OF SLUSHY ACCUMULATION POSSIBLE OVER INTERIOR NW WISC WHERE RUC13 ANIMATION OF BDRY LYR TEMPERATURES SHOWS A POCKET OF DIABATIC COOLING. SHOULD BE SHORT LIVED HOWEVER AS BETTER UVV PUSHES EAST BY 12Z. BRISK NW WINDS TODAY AS ANY MIXING TAPS INTO UNIDIRECTIONAL SFC/85H FLOW. ANOMALOUS VORTEX OVER NRN MANITOBA WILL SAG SOUTH PER MDL CONSENSUS OVER THE REMAINDER OF THE WEEKEND. SOME DIFFERENCES ON MINOR QPF/POPS...HOWEVER STILL LOOKS LIKE A FEW SHOWERS WILL SKIRT NRN HALF OF CWA SUNDAY/SUNDAY NIGHT. BEYOND THAT...SEVERAL WEAK DISTURBANCES WILL SLIDE QUICKLY ALONG WNW MID LVL FLOW THROUGH TUESDAY. LOW POPS/QPF AS DEEP LAYER MOISTURE WILL BE LACKING. EXTENDED...SLOW MODERATION IN COOL AIR OVER CWA. NO MAJOR SYSTEMS THROUGH FRIDAY AS RATHER WEAK MID LVL FLOW DOMINATES NRN CONUS. && .AVIATION... N AREA OF RAIN AND SNOW WAS FALLING OVER FAR EASTERN MINNESOTA AND OVER NORTHWEST WISCONSIN EARLY THIS MORNING. IFR OR LOWER MVFR CONDITIONS WERE OCCURRING WITH THIS PRECIPITATION...WITH VFR CONDITIONS ELSEWHERE. THE AREA OF LOW PRESSURE RESPONSIBLE FOR THIS PRECIPITATION WILL MOVE OFF TO THE EAST THIS MORNING...BRINGING AN END TO THE PRECIPITATION FOR MOST AREAS BY AFTERNOON. CEILINGS SHOULD LIFT TO VFR ALL AREAS BY AFTERNOON...WITH THE EXCEPTION OF THE KPBH AND KIWD AREAS...WHERE MVFR CONDITIONS WILL LINGER. && POINT TEMPS/POPS... DLH 46 29 55 32 / 10 10 20 20 INL 46 28 51 29 / 10 10 30 20 BRD 50 32 60 36 / 10 10 10 10 HYR 45 28 58 35 / 40 10 10 20 ASX 44 29 56 34 / 50 10 20 30 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LSZ121- LSZ146-LSZ147-LSZ148. SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ140- LSZ141-LSZ142-LSZ143-LSZ144-LSZ145. $$ CANNON/MELDE mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 130 AM CDT SAT MAY 3 2008 .DISCUSSION... UPDATE TO OVERNIGHT PERIOD AS LATEST RUC13 AND SFC OBS/RADAR INDICATE BACK EDGE OF PRECIP SHIELD IS DIMINISHING AS DRIER AIR IS PULLED SOUTH. DECREASED POPS/QPF WEST OF TWIN PORTS AS MORE SIGNIFICANT 85/50 OMEGA HAS MOVED FARTHER EAST. EARLIER SNOW MIXING WITH RAIN WAS BEING ASSISTED BY DEEPER UVV OVER TWIN PORTS BUT NOW THAT THIS AREA HAS MOVED EAST...POPTYP REVERTING TO MORE LIQUID. WILL LEAVE RAIN/SNOW MIX BUT HAVE DECIDED TO DROP ACCUMULATIONS OVER CWA EXCEPT ARROWHEAD. POPTYP/SNOW AMNTS HAVE BEEN CHANGED TO REFLECT LATEST RUC13 SFC/925/850 THERMAL FIELDS. THIS MEANS HIGHEST PROBABILITY OF ACCUMULATING SNOW IS OVER NRN LAKE COUNTY WHERE DEEPER MSTR REMAINS LONG ENOUGH FOR THERMAL PROFILE COOLING. && POINT TEMPS/POPS... DLH 46 28 52 34 / 40 10 20 20 INL 46 28 51 30 / 20 10 30 20 BRD 50 31 60 37 / 10 10 10 10 HYR 45 29 59 37 / 50 10 10 10 ASX 46 30 54 37 / 50 10 10 30 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121- LSZ140-LSZ141-LSZ142-LSZ143-LSZ144-LSZ145-LSZ146-LSZ147- LSZ148. $$ CANNON/BERDES mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 1251 AM CDT FRI MAY 2 2008 ...UPDATE TO AVIATION... .UPDATE... 0335Z... DRY LINE BEGINNING TO MERGE WITH COLD FRONT AS IT RETROGRADES WESTWARD. RESULT OF THE MERGER HAS BEEN RAPID DEVELOPMENT OF A SQUALL LINE OVER CENTRAL KANSAS INTO NORTH CENTRAL OKLAHOMA. SQUALL LINE WILL SHIFT EASTWARD OVERNIGHT AND AFFECT THE WESTERN CWA. SQUALL LINE EXPECTED TO MAINLY PRODUCE DAMAGING STRAIGHT LINE WINDS AND LARGE HAIL...HOWEVER SHEAR VALUES STILL ENOUGH TO WARRANT MENTION OF POSSIBLE EMBEDDED TORNADOES. AHEAD OF THE SQUALL LINE....DISCRETE SUPERCELL AFFECTING BOURBON COUNTY STILL HAS THE POTENTIAL OF A TORNADO WITH GOOD LOW LEVEL SHEAR INDICATED ON RADAR, IN ADDITION TO GOLF BALL SIZE HAIL. LINDENBERG && .DISCUSSION... A DRYLINE ASSOCIATED WITH AN APPROACHING STORM SYSTEM SURGED INTO KANSAS FLINT HILLS THIS AFTERNOON. THIS FEATURE WILL BE MONITORED CLOSELY OVER THE NEXT 6-8 HOURS FOR A LOW END CHANCE OF THUNDERSTORM DEVELOPMENT. MEANWHILE...A 110 KNOT UPPER SPEED MAX STILL RESIDES OVER THE SOUTHERN AND CENTRAL ROCKIES. THIS FEATURE WILL EVENTUALLY PROVIDE LIFT FOR EXPLOSIVE THUNDERSTORM DEVELOPMENT OVER KANSAS AND OKLAHOMA TONIGHT. THIS CLUSTER OF THUNDERSTORMS WILL BE THE MAIN SHOW FOR EXTREME SOUTHEAST KANSAS AND THE MISSOURI OZARKS TOWARD FRIDAY MORNING. SHORT TERM (TONIGHT - FRIDAY)... AS PREVIOUSLY MENTIONED...THE DRYLINE AT 1945Z CUTS ACROSS THE SOUTHERN FLINT HILLS EXTENDING FROM LAWRENCE KANSAS...TO PONCA CITY OKLAHOMA. AS ANTICIPATED BY SHORT TERM MODELS...EVIDENCE OF A DEVELOPING SURFACE LOW WAS INDICATED BY OBSERVATIONS OVER CENTRAL OKLAHOMA. THIS LOW WAS OCCURRING IN RESPONSE TO INCREASING DIFFLUENT FLOW ALOFT. MOISTURE CHANNEL IMAGERY DEPICTS THIS INCREASE IN DIFFLUENCE OVER THE SOUTHERN HIGH PLAINS. THE POPULAR QUESTION FOR THIS AFTERNOON REGARDS WHETHER OR NOT DISCRETE SUPERCELLS WILL DEVELOP ALONG THE DRYLINE PRIOR TO SUNSET. MY GUESS IS NO...UNLESS IT OCCURS UP IN NW MISSOURI OR FAR NE KANSAS. THE AIRMASS OVER EASTERN KANSAS AND OKLAHOMA HAS TOO GREAT OF A DESERT INFLUENCE...CREATING A VERY STRONG CAP. AS A MATTER OF FACT...19Z RUC ANALYSIS OF MEAN LAYER INHIBITION SUGGESTS THAT VALUES OVER FLINT HILLS RANGE FROM 150 - 350 J/KG. DESPITE SOME ADDITIONAL LIFT OCCURRING AS THE SOUTHERN PLAINS DIFFLUENCE INTERSECTS THE DRYLINE LATE THIS AFTERNOON...ALONG WITH ENHANCED LOW LEVEL CONVERGENCE NEAR SEDAN/FREDONIA KS FROM A DEVELOPING SURFACE LOW OVER OKLAHOMA...I DOUBT THAT THESE LIFTING MECHANISMS WILL BECOME STRONG ENOUGH TO PENETRATE UPDRAFTS THROUGH THE CAP. BOTH THE WRF AND RUC SHOW STORM INITIATION NEAR SUDAN OR FREDONIA KANSAS BY 00Z-03Z...HOWEVER...BOTH MODELS CONTINUE TO OVERESTIMATE MOISTURE LEVELS. THIS OVERESTIMATION FALSELY WEAKENS THE CAP. THIS IS ESPECIALLY EVIDENT IN THE RUC...WHICH SUGGESTS AN AXIS OF 69-70 DEWPOINTS ALONG THE DRYLINE. MORE REALISTICALLY PER LOCAL OBS...DEW POINT MEASUREMENTS ARE ONLY AROUND 58-62 DEGREES. WHAT WILL BREAK THE CAP IS THE APPROACH OF A 110 KNOT SPEED MAX WITHIN THE JET STREAM...ALONG WITH MASS CONVERGENCE IN RESPONSE TO AN INCREASING LOW LEVEL JET OVER EASTERN OKLAHOMA. THIS ADDITIONAL FORCING WILL OCCUR AT AROUND 03-05Z TONIGHT...IGNITING A CLUSTER OR SQUALL LINE OF THUNDERSTORMS OVER NORTHERN OKLAHOMA AND EASTERN KANSAS. THESE STORMS WILL TRACK INTO EXTREME SOUTHEAST KANSAS AND WESTERN MISSOURI AFTER MIDNIGHT. AREAS ALONG AND WEST OF A LINE FROM CASSVILLE TO OSCEOLA WILL SUSTAIN THE GREATEST CHANCES OF EXPERIENCING THIS ACTIVITY PRIOR TO 6AM. DUE TO EXTREME WIND SHEAR IN TONIGHTS ENVIRONMENT...LARGE HAIL UP TO THE SIZE OF GOLF BALLS...AND DAMAGING WINDS IN EXCESS OF 70 MPH WILL OCCUR NEAR THE STRONGEST UPDRAFTS. SQUALL LINE TORNADOES CAN NOT BE RULED OUT ALONG THE LEADING EDGE OF THE SQUALL. MODELS STILL INDICATE THAT AREAS ALONG AND EAST OF HIGHWAY 65 WILL REMAIN WITHIN THE WARM SECTOR HEADING INTO FRIDAYS DAY PERIOD. THERE MAY BE A BRIEF WINDOW OF OPPORTUNITY FOR UPDRAFTS TO BECOME MORE DISCRETE IN NATURE OVER THE EASTERN OZARKS. 0-6KM SHEAR VECTORS ASSUME AN ORIENTATION THATS MORE FAVORABLE FOR DISCRETE CELLS BY 12-15Z. THIS STILL REMAINS A SHORT TERM FORECAST CHALLENGE...AND DEPENDS ON TWO VARIABLES. ONE...HOW WILL TONIGHT/FRIDAY MORNINGS CONVECTION AND CLOUD COVER DISTORT INSTABILITY LEVELS. AND TWO...WILL THE COLD FRONT BECOME PROGRESSIVE ENOUGH TO SHIFT EAST OF THE OZARKS PRIOR TO ADDITIONAL DEVELOPMENT OF POSSIBLE DIURNAL INSTABILITY. AT ANY RATE...ALL PRECIPITATION SHOULD SHIFT EAST OF THE OZARKS BY FRIDAY MID AFTERNOON...SETTING UP A COOLER BUT DRY FORECAST FOR FRIDAY EVENING AND OVERNIGHT. LONG TERM (SATURDAY - WEDNESDAY)... SEASONAL AND DRY CONDITIONS ARE STILL EXPECTED FOR THE WEEKEND AND EARLY NEXT WEEK. FLOW BECOMES NORTHWESTERLY IN THE WAKE OF TONIGHTS SYSTEM...AS HIGH PRESSURE AT THE SURFACE INCREASES. RAIN CHANCES ENTER THE FORECAST BY TUESDAY...AS MEDIUM RANGE MODELS SUGGEST THAT AN UPPER LEVEL TROUGH DIGS INTO THE WESTERN CONUS. THIS WILL CREATE A PATTERN FAVORABLE FOR MOISTURE TO RETURN. CRAMER && .AVIATION... FOR THE 06Z TAF PACKAGE...LINE OF STRONG TO SEVERE THUNDERSTORMS HAS DEVELOPED AHEAD OF A COLD FRONT IN EAST KANSAS AND CENTRAL OKLAHOMA. AT 0530Z...THUNDERSTORMS EXTEND FROM NEAR KTOP TO KUKL TO KPNC TO KCHK AND IS TRACKING EAST AROUND 30 KNOTS. THUNDERSTORMS WILL EFFECT AERODROMES AFTER 07Z WITH REDUCTION OF VISIBILITIES AND CEILINGS TO IFR POSSIBLE. SHOWERS AND THUNDERSTORMS WILL END BY 12Z AS THE FRONT MOVES EAST THROUGH THE TERMINALS AND CEILINGS GRADUALLY RAISE TO VFR. ANGLE && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 1237 AM CDT FRI MAY 2 2008 .UPDATE... CONVECTION HAS TEMPORARILY UNDERGONE A FAIRLY RAPID DOWNTURN IN INTENSITY AS OUTFLOW FROM PREVIOUS CONVECTION HAS PUSHED SOUTH AND CREATED A MESO WARM FRONT ARCING FROM RANDOLPH COUNTY TO LINN AND ANDERSON COUNTIES IN KANSAS...EFFECTIVELY UNDERCUTTING UPDRAFT COLUMNS WITH MORE STABILIZED RAIN COOLED AIR. IN ADDITION...STORMS PROPAGATING ACROSS NERN MISSOURI ARE BEGINNING TO OUTRUN THE INSTABILITY AXIS AND SUPPORTIVE SHEAR...LEADING TO MORE PULSING CONVECTION. HOWEVER...RAPID UPSCALE CONVECTIVE GROWTH NOW OCCURRING ALONG THE COLD FRONT (WHICH HAS OVERTAKEN THE DRYLINE) IN AN AREA OF EXTREME UPPER LEVEL DIFFLUENCE AND DEEP LAYER VERTICAL MOTION. MLCAPES AHEAD OF THE COLD FRONT REMAIN 1500-2000 J/KG WITH 0-6 KM SHEAR VALUES IN EXCESS OF 50 KT ADVECTING ACROSS THE BOUNDARY. WARM SECTOR IS CURRENTLY BEING REINVIGORATED BY A H8 40-50KT LLJ WITH +13C DEWPOINTS...WHICH SHOULD BEGIN TO LIFT THE MESO WARM FRONTAL BOUNDARY NWD WITH TIME. THE QUICKLY DEVELOPING LINEAR CONVECTION SHOULD SLOWLY MOVE EAST OVER THE NEXT SEVERAL HOURS IN RELATION TO THE MIDLEVEL LOW CENTER PUNCHING EWD. ELEMENTS WITHIN THE LINE WILL PROPAGATE NORTHEAST...AND ALTHOUGH LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREATS WITH THE LINE...LOW LEVEL SHEAR (0-1 KM SRH 200-300 M2/S2 AND 0-3KM SRH 300-400 M2/S2) WOULD SUPPORT EMBEDDED SUPERCELLULAR AND QLCS STRUCTURE WITH POSSIBLE BOW HEAD OR INFLOW NOTCH TORNADOES...AS ALREADY HAS BEEN OBSERVED FROM KICT RADAR. INITIAL NRN MORE ISOLATED SUPERCELL ACROSS FAR NERN KANSAS MAINLY A HAIL THREAT...WITH THE AFOREMENTIONED LINEAR FEATURE ENTERING ERN KANSAS CWA COUNTIES BETWEEN 1 AM AND 130 AM. 21 ...PREVIOUS UPDATE... /510 PM CDT FRI MAY 1 2008/ WATCHING POTENTIAL OF STORM DEVELOPMENT LATE THIS AFTERNOON IN MOISTURE AXIS THAT CURRENTLY EXTENDS FROM NORTHEAST OKLAHOMA NORTHEAST ALONG KANSAS AND MISSOURI BORDER. 21Z TOPEKA SOUNDING WHICH WAS WEST OF THIS AXIS...SHOWING CAPPING HAS GREATLY ERODED JUST WEST OF THE MOISTURE AXIS AND VISIBLE SATELLITE SHOWING TOWERING CU DEVELOPING ALONG WITH WESTERN EDGE OF THIS MOISTURE AXIS...WHERE CAP IS WEAKENING. IMPRESSIVE SURFACE HEATING HAS OCCURRED THIS AFTERNOON...WITH TEMPERATURES IN THE LOW TO MID 80S AND LOW AND MID LEVEL LAPSE RATES ARE IMPRESSIVE AS WELL...WHICH WOULD POINT TO STRONG UP DRAFTS IS STORMS CAN DEVELOP. LIMITING FACTOR REMAINS THE LOW LEVEL MOISTURE WITH SURFACE DEWPOINTS STILL STRUGGLING IN THE LOWER 60S UP INTO WESTERN AREAS. STILL GOOD ENOUGH TO SUPPORT INDIVIDUAL STORMS...AND WITH BULK SHEAR VALUES IN THE 40 KT RANGE...WOULD BE GOOD ENOUGH TO SUPPORT SUPERCELL DEVELOPMENT WITH LARGE HAIL...DAMAGING WINDS AND ISOLATED TORNADOES. FOR WARNING PURPOSES...WITH FREEZING LEVELS RUNNING IN THE 11-12K FT RANGE...WOULD EXPECT ONE INCH HAIL WITH 50 DBZ TO 30K FT AND 60 DBZ IN THE 25K FT RANGE. VILS AROUND 50 WOULD ALSO POINT TO 1 INCH HAIL. DURING THE LATE EVENING HOURS...MAY SEE DRY LINE RETREATING BACK TOWARD THE COLD FRONT AND A SURFACE LOW THAT IS CURRENTLY DEEPENING IN THE OKLAHOMA PANHANDLE...AND IS EXPECTED TO MOVE INTO SOUTH CENTRAL KANSAS BY 03Z. AS THE UPPER LOW EMERGES INTO THE PLAINS TONIGHT...ITS ADDED DYNAMICS SHOULD CONTRIBUTE TO ADDITIONAL DEVELOPMENT OF STORMS ALONG THIS FRONT...WITH MORE HEAVY RAINFALL POSSIBLE INTO THE AREA OVERNIGHT. PC && .PREV DISCUSSION... /419 PM CDT FRI MAY 1 2008/ MAIN FOCUS OF THE FORECAST CONTINUES TO BE WITH STORM DEVELOPMENT AND SEVERE POTENTIAL FROM THIS EVENING INTO FRIDAY MORNING. TEMPERATURES HAVE WARMED QUITE SUBSTANTIALLY TODAY AHEAD OF THE SURFACE LOW NOW CENTERED OVER EAST CENTRAL NEBRASKA. DEWPOINTS HAVE RECOVERED SOME TODAY...WITH SCATTERED READINGS IN THE LOWER 60S ACROSS EASTERN KANSAS AND WESTERN MISSOURI. WINDS WERE RATHER STRONG THIS AFTERNOON...WITH GUSTS INTO THE UPPER 30 MPH RANGE...BUT HAVE REMAINED BELOW ADVISORY CRITERIA. THEREFORE...HAVE CANCELLED THE WIND ADVISORY. A SUBSTANTIAL CAP HAS KEPT CONVECTION FROM INITIATING THUS FAR. MODEL INDICATIONS ARE THAT THE CAP IS WEAKENING THIS AFTERNOON...AND MAY BE BROKEN THIS EVENING MAINLY ALONG THE DRYLINE/COLD FRONT. HAVE BEEN WATCHING THE DRYLINE PUSH EAST TODAY...AND APPEARS TO HAVE REACHED RIGHT TO THE MISSOURI BORDER WITH NEBRASKA...SOUTH TO EMPORIA AND INTO NORTH CENTRAL OKLAHOMA. THE EDGE OF THE SURFACE MOIST AXIS/PSEUDO DRYLINE IS EXPECTED TO PUSH A BIT FURTHER EAST THIS EVENING. THE RUC FORECAST MODEL INDICATES THE DRYLINE MAY REACH A CLARINDA TO KANSAS CITY LINE BEFORE RETROGRADING SOME AFTER 00Z. THIS SOLUTION MAY BE REASONABLE...AS THE PUSH OF THE UPPER JET MAX WITH THE MAIN PART OF THE UPPER LOW MAY WHAT IS NEEDED LATER TONIGHT. THE NAM HAS BEEN THE FASTER OF THE SOLUTIONS TODAY WITH THE COLD FRONT/DRYLINE PROGRESSION...WHILE THE GFS HAS BEEN ON THE SLOWER END. THE SREF AND RUC HAVE BEEN MORE IN THE MIDDLE. THE LATEST 18Z NAM LOOKS MORE REASONABLE THAN ITS FASTER 12Z COUNTERPART. STILL NOT SURE THAT ANY ONE MODEL IS FAR SUPERIOR TODAY. THE SURFACE LOW PRESSURE SYSTEM OVER EAST CENTRAL NEBRASKA WILL CONTINUE TO OCCLUDE TONIGHT...WHILE A SECOND SURFACE LOW STARTS TO PROGRESS EASTWARD FROM THE PANHANDLE REGION. THE SURFACE FRONTAL BOUNDARY BETWEEN THESE TWO LOW PRESSURE CENTERS WILL PUSH SLOWLY EAST INTO THE FORECAST AREA TONIGHT...AND EVENTUALLY OVERTAKE THE DRYLINE LATER TONIGHT. AS FOR CONVECTIVE INITIATION...AM SEEING SOME SIGNS OF BETTER VERTICAL CUMULUS DEVELOPMENT NOW ACROSS THE FLINT HILLS IN SOUTHEAST KANSAS. EXPECTATIONS ARE THAT THUNDERSTORMS MAY FIRE FIRST IN THIS AREA WHERE THE CAP IS EXPECTED TO BE BROKEN BY LATE AFTERNOON. ADDITIONAL DEVELOPMENT NEAR THE DRY LINE IS EXPECTED TO BUILD NORTHEAST INTO THE FORECAST AREA...FROM EAST CENTRAL KANSAS NORTH AND EAST INTO WESTERN MISSOURI FROM MID TO LATE EVENING. SUPERCELLS WILL BE POSSIBLE THIS EVENING...WITH THUNDERSTORMS THEN EXPECTED TO EVOLVE MORE INTO A LINE OF STORMS AS THE FRONT STARTS TO MOVE ACROSS THE FORECAST AREA DURING THE OVERNIGHT TONIGHT. THE PRIMARY SEVERE THREATS WITH THE STORMS WILL BE LARGE HAIL AND DAMAGING STRAIGHT LINE WINDS...BUT THERE IS ALSO AN ISOLATED TORNADO THREAT. THE FRONT WILL PUSH RATHER SLOWLY EAST ACROSS THE FORECAST AREA TONIGHT...SO CONVECTION IS EXPECTED TO REMAIN ACROSS PORTIONS OF CENTRAL MISSOURI INTO THE MORNING HOURS TOMORROW. THERE ARE SOME CONCERNS THAT WITH THE SLOW MOVEMENT OF THE FEATURES THAT PRECIPITATION AMOUNTS COULD EXCEED ONE INCH MAINLY ACROSS CENTRAL MISSOURI...EVEN THOUGH INDIVIDUAL STORMS SHOULD MOVE QUICKLY. HEADWATER GUIDANCE IS JUST LESS THAN AN INCH AND A HALF IN THAT AREA. WILL HAVE TO KEEP ALERT IF DURATION OF PRECIPITATION LOOKS TO BE LONG ENOUGH THAT WE MIGHT HAVE FLOODING CONCERNS. NOT MANY CHANGES MADE FOR THE FRIDAY INTO SATURDAY TIME FRAME...WITH COOLER TEMPERATURES MOVING IN AND SOME LOW END PRECIPITATION CHANCES FOR PRECIPITATION WRAPPING AROUND THE BACKSIDE OF THE DEPARTING SYSTEM. STOFLET LONG RANGE (SUNDAY-THURSDAY)... EARLY PART OF EXTENDED APPEARS RATHER TRANQUIL AS WEAK UPPER LEVEL RIDGING BUILDS ACROSS CENTRAL PLAINS. RIDGING EXPECTED TO HOLD AT LEAST THROUGH MID-WEEK WITH SPLIT FLOW KEEPING SOUTHERN STREAM QUASI-CUTOFF LOW ANCHORED OVER BAJA. NAEFS PESSIMISTIC IN LIFTING LOW TOO QUICKLY WITH THE BULK OF THE MEMBERS DEPICTING UPPER LOW REMAINING OVER BAJA THROUGH WEDNESDAY...THOUGH OPERATIONAL GFS STARTS LIFTING SYSTEM INTO PLAINS BY WEDNESDAY NIGHT. 00Z EC SIMILAR IN TIMING WITH 12Z GFS...BUT THERE APPEARS TO BE ENOUGH VARIANCE IN THE ENSEMBLE MEMBERS TO QUESTION BOTH MODELS SOLUTIONS. GIVEN EXPECTED SLOWER MOVEMENT OF POTENTIAL WEATHER MAKER...BACKED OFF ON PRECIPITATION CHANCES IN THE MONDAY THROUGH TUESDAY NIGHT TIME PERIOD...BUT MAINTAINED LOW CHANCES POPS WEDNESDAY INTO THURSDAY. THE EVENTUAL SYSTEM THAT DOES EJECT INTO PLAINS WILL BE RATHER POTENT...BUT MIXED SIGNALS ON WHETHER IT WILL BRING HEAVY RAIN OR SEVERE THREAT GIVEN DIFFERENCES IN UPPER LOW TRACK. AS FAR AS TEMPERATURES...SURFACE RIDGING AND LOW LEVEL EAST TO SOUTHEAST FLOW WILL KEEP TEMPERATURES A FEW DEGREES BELOW SEASONAL NORMALS EARLY IN THE PERIOD. MAY BE A LITTLE OPTIMISTIC WITH TEMPERATURES ON MONDAY...HOWEVER STRONGER INSOLATION SHOULD HELP TO MODIFIED COOLER AIRMASS THAT LINGERS WITH SURFACE HIGH. BY TUESDAY...EXPECT TO SEE TEMPERATURES CLIMBED BACK TOWARD NORMAL BY TUESDAY AS HEIGHTS BUILD AND SURFACE FLOW BECOMES MORE SOUTHERLY...THOUGH INCREASING LOW LEVEL MOISTURE ADVECTION WILL LIMIT THE EXTEND OF WARM-UP. OVERALL..USED A BLEND OF GRIDDED MOS AND ECMWF SURFACE TEMPERATURES FOR TEMPERATURE TRENDS. DEPENDING ON MODE OF PRECIPITATION EVOLUTION ON THURSDAY...MAY NEED TO LOWER TEMPERATURES A CATEGORY. 24 && .AVIATION... FOR THE 06Z TAFS...IMMEDIATE THREAT IS TIMING OF SQUALL LINE MOVING ACROSS NORTHEAST KANSAS. LOCAL ARW WRF HANDLING CONVECTION FAIRLY WELL...WITH NORTHERN END OF LINE MOVING INTO THE KSTJ AND KMCI TAFS BETWEEN 0630-0700 UTC AND INTO THE KMKC TAF BETWEEN 07 AND 08 UTC. THE MOST INTENSE PART OF THE LINE LIKELY WILL PASS SOUTH OF KMCI AND KSTJ...WITH KMKC EXPERIENCING STRONGER PORTION OF LINE. BASED ON CIGS ACROSS NORTHEAST KANSAS...LOWERED CIGS INTO MVFR RANGE AS A RESULT OF +TSRA AND ADDED GUSTS UP TO 45KT...THOUGH WOULD NOT BE SURPRISED TO SEE GREATER THAN 50KTS. AFTER LINE CLEARS...AM A LITTLE MORE OPTIMISTIC WITH CIG RECOVERY COUNTER TO MET AND MAV GUIDANCE WHICH KEEP MVFR CIGS THROUGH AT LEAST MID-MORNING. BEYOND 15 UTC...THE ONLY FORECAST CONCERN WILL BE SOUTH TO SOUTHWEST WINDS WITH POTENTIAL GUSTS TO 30KTS. 24 && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 319 AM CDT FRI MAY 2 2008 .SYNOPSIS... AT 00Z...SFC CYCLONE WAS BEGINNING TO OCCLUDE OVER THE MISSOURI RIVER VALLEY REGION...WITH SFC LOW /AROUND 934 MB/ LOCATED JUST SOUTHEAST OF PIR BY 08Z. THIS LOW IS EXPECTED TO SHIFT SOUTH AND THEN EAST INTO EASTERN NEB THROUGH FRIDAY. THIS PROCESS WILL OCCUR IN CONJUNCTION WITH STRONG 100 KT 250 MB JET MAX EXITING TROUGH BASIN LOCATED OVER THE SOUTHERN PLAINS. DRY AIR HAS INFILTRATED THE EASTERN SIDE OF MID LVL LOW POSITIONED OVER FAR WESTERN NEB...WHICH HAS LIMITED PRECIP DEVELOPMENT ACROSS MUCH OF THE CWA. HOWEVER...AS MID LVL LOW TRANSLATES EASTWARD ACROSS NEB ON FRIDAY...MOISTURE IS EXPECTED TO WRAP WEST AND SOUTH AROUND THE MID LVL CIRCULATION...WITH A TROWAL ENTERING NORTHWEST NEB. THIS WILL FAVOR THE REDEVELOPMENT OF PRECIPITATION FRIDAY MORNING INTO THE AFTERNOON. && .DISCUSSION... GFS AND NAM SHOW SUBTLE DIFFERENCES REGARDING THE LOCATION OF THE SFC LOW LOCATED OVER SOUTH CENTRAL SD. BASED ON LATEST SFC OBS...THE NAM APPEARS SLIGHTLY TOO FAR EAST WITH THE PLACEMENT OF THIS FEATURE...WHILE THE GFS IS CLOSER TO REALITY /AND IS SUPPORTED BY LATEST RUC AND ECMWF/. THUS...WILL FAVOR THE GFS THROUGH THE NEXT 24 HRS WITH PLACEMENT OF QPF/WX. AS SFC LOW SLIDES SOUTH AND THEN EAST INTO EASTERN NEB...INCREASING SFC PRESSURE GRADIENT AND MOMENTUM TRANSFER FROM ABOVE WILL LEAD TO STRONG WINDS...WITH GUSTS UP TO 40 KT. MEANWHILE...MAIN SFC LOW OVER IA WILL BEGIN LIFTING NORTHEAST TOWARD THE GRT LAKES REGION THROUGH FRIDAY NIGHT. LARGE SCALE ASCENT AND TROWAL WILL SHIFT FROM NORTHWESTERN NEB FRIDAY AFTERNOON INTO SOUTHERN/SOUTH CENTRAL NEB FRIDAY NIGHT. HEAVIEST PRECIPITATION SHOULD OCCUR AS THESE FEATURES TRANSLATE ACROSS THE STATE. GFS INDICATES DRY AIR WILL REMAIN OVER THE EASTERN HALF OF THE CWA DURING MOST OF THE DAY FRIDAY...THUS EXPECT LOWEST POPS TO INITIALLY BE LOCATED EAST OF A VTN TO BBW LINE. GFS MAY BE SLIGHTLY TOO SLOW WITH COLD AIR SLIDING SOUTHEAST INTO THE NORTHWESTERN QUADRANT OF CWA DURING FRIDAY...GIVEN LOWER DEWPOINTS ARE SITUATED IN SOUTHWEST SD...WHICH COULD FILTER SOUTHEAST AND FAVOR LOWER WET BULB TEMPERATURES. IF THIS SCENARIO PLAYS OUT...TRANSITION TO ALL SNOW IN SHERIDAN/WESTERN CHERRY COUNTIES SHOULD TAKE PLACE BY 12Z FRIDAY /WHICH APPEARS LIKELY GIVEN THAT THE TRANSITION TO ALL SNOW HAS ALREADY TAKEN PLACE ACROSS MOST OF THE WESTERN PANHANDLE/. A 15 HR SNOWFALL EVENT OVER FAR NORTHWEST CWA APPEARS POSSIBLE...WHICH COULD YIELD UP TO 6 INCHES OF SNOW. WILL CONTINUE WITH WINTER STORM WARNING IN SHERIDAN/CHERRY COUNTIES...WITH POTENTIAL UPGRADE TO BLIZZARD WARNING NOT OUT OF THE QUESTION /WILL CONTINUE TO EVALUATE/. SNOW WILL SPREAD SOUTHEAST ACROSS THE REMAINDER OF THE CWA FRIDAY NIGHT...WITH 3 TO 6 HR DURATION EVENT FOR MOST LOCATIONS...PRODUCING 1/2 TO 1 INCH OF ACCUMULATION FOR REMAINDER OF THE FCST AREA. MODELS INDICATE THAT SKIES WILL CLEAR TOWARD SUNRISE OVER MOST OF THE CWA...WHICH STILL SEEMS TO SUPPORT COLD MAV/MET GUIDANCE /PARTICULARLY OVER THE NORTHWEST WHERE SNOW COVER APPEARS MOST LIKELY/. NEXT TROUGH APPROACHES THE SOUTHWESTERN U.S. SUNDAY NIGHT...WITH MID LVL HEIGHTS RISING OVER THE CENTRAL PLAINS. CONTINUED TO BUMP TEMPERATURES UP A FEW DEGREES GOING INTO THE FIRST HALF OF NEXT WEEK AS SOUTHERLY LOW LVL FLOW INCREASES ACROSS THE REGION IN RESPONSE TO DEVELOPING LEE TROUGH. INCREASING INSTABILITY BY MONDAY EVENING SUPPORTS THUNDERSTORMS ALONG SFC TROUGH AXIS OVER THE PANHANDLE...AND THEN SPREADING EASTWARD ACROSS THE CWA MONDAY NIGHT /HIGHEST PROBABILITY MAY RESIDE OVER SOUTHWESTERN/SOUTH CENTRAL NEB WHERE NOSE OF 30-50 KT LLJ IS FCST BY GFS TO RESIDE/. NORTHERN STREAM S/W TROUGH BEGINS TO SWEEP EAST ACROSS THE PLAINS ON TUESDAY /WHICH IS SUPPORTED BY 00Z GFS/ECMWF/. HOWEVER...UNCERTAINTY IN TIMING OF THIS FEATURE PRECLUDES ADDITIONAL CHANGES FOR DAYS 5 AND 6. && .AVIATION... FLIGHT CONDITIONS WILL WORSEN TODAY AS IFR CONDITIONS BECOME WIDESPREAD. THE LARGE SLOW-MOVING STORM WILL DRIFT EAST ACROSS NEBRASKA TODAY AND TONIGHT. TODAY... WEST OF HIGHWAY 83...GENERALLY IFR CONDITIONS...WINDS 30025-35KT G45KT AND AREAS OF 1SM SN OVC008. EAST OF HIGHWAY 83...AREAS OF IFR...WINDS 30015G25KT INCREASING TO 30025G35KT AND AREAS 3SM SHRA BR OVC012. TONIGHT... WEST OF HIGHWAY 83...CONDITIONS SHOULD IMPROVE TO VFR BY 06Z. EAST OF HIGHWAY 83...SOME IMPROVEMENT...MAINLY AFTER 06Z. && .LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS 025-026-037-038-056>059-069>071. WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR NEZ004-023- 024-094. WINTER STORM WATCH FROM 7 AM CDT THIS MORNING THROUGH SATURDAY MORNING FOR NEZ005-006-008-009-025-026. SNOW AND BLOWING SNOW ADVISORY UNTIL 1 AM CDT /MIDNIGHT MDT/ SATURDAY FOR NEZ022-035-036. && $$ GARNER/CDC ne AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ALBUQUERQUE NM 659 PM MDT FRI MAY 2 2008 .UPDATE... EXPANDED FREEZE WARNING FURTHER SOUTH AND WEST...AND EXTENDED IT UNTIL 9 AM MDT DUE TO THE STRENGTH OF THE COLD FRONT PENETRATING THE NORTHEAST PLAINS AND RECENT MODEL GUIDANCE. WE ARE SOMEWHAT SKEPTICAL THAT SOUTHERN PORTIONS OF ROOSEVELT COUNTY WILL REACH FREEZING AS WINDS MAY REMAIN SOMEWHAT BREEZY THERE UNTIL AFTER SUNRISE. ALSO DROPPED TEMPERATURES A FEW DEGREES IN THE ALBUQUERQUE AREA BASED ON RECENT MODEL GUIDANCE AND THIS MORNINGS LOW TEMPERATURE REPORTS. ANOTHER NIGHT OF FREEZING TEMPERATURES IS ON TAP FOR THE STATES LARGEST CITY...BUT A FREEZE WARNING IS NOT NEEDED IN ALBUQUERQUE BECAUSE THE AVERAGE LAST FREEZE FOR MUCH OF THE METRO AREA IS IN EARLY MAY. LASTLY...INCREASED WINDS FOR THIS EVENING IN THE NORTHEAST...AND DROPPED THE SMALL CHANCE FOR PRECIPITATION... BASED ON RECENT OBSERVATION AND RADAR TRENDS. WILL ALLOW THE RED FLAG WARNING TO EXPIRE AT 7 PM MDT. 44 && .PREV DISCUSSION... 203 PM MDT FRI MAY 2 2008...700MB FLOW ALONG WITH SURFACE PRESSURE GRADIENT HAVE RELAXED CONSIDERABLY ACROSS NM TODAY. STRONGEST WINDS RESIDE IN AREAS ALONG AND TO THE EAST OF THE CENTRAL MTN CHAIN AS WELL AS IN FAVORED NW FLOW LOCATIONS SUCH AS KABQ AND KFMN. LATEST WATER VAPOR LOOP SHOWS AN IMPRESSIVE DOUBLE BARREL UPPER CIRCULATION OVER THE CENTRAL PLAINS STATES. SURFACE ANALYSIS SHOWS A 1005MB LOW PRESSURE CENTER OVER NE NEW MEXICO WITH A SECONDARY BLAST OF COLD AIR HEADING SOUTH OUT OF EASTERN COLORADO. LATEST RUC13 ANALYSIS SHOWS A COLD FRONT WILL SURGE SOUTH ACROSS EASTERN NM THIS EVENING AS A 1030MB HIGH PRESSURE BUILDS OVER THE CENTRAL ROCKIES. FREEZING TEMPERATURES ARE A VERY GOOD BET ACROSS MUCH OF THE EASTERN PLAINS ALONG AND NORTH OF I40 SO WILL ISSUE A FREEZE WARNING ACROSS THE NE PLAINS. CONCERNED AGAIN ABOUT FREEZING TEMPS AGAIN ACROSS THE ABQ METRO AREA TONIGHT HOWEVER PRESENCE OF AN EAST WIND IN MET/MOS STATISTICAL NUMBERS BY 12Z COMPLICATES MATTER SO WILL GO WITH ANOTHER SPS. CURRENT RED FLAG WARNING VERIFYING ACROSS MUCH OF THE SANDIA/MANZANO/GALLINAS MOUNTAINS AND THE EAST CENTRAL PLAINS SO WILL LEAVE UNCHANGED THROUGH 01Z. 12Z MODEL SUITE IN EXCELLENT AGREEMENT THAT A WEAK RIDGE/QUASI- ZONAL FLOW WILL DEVELOP OVER THE SOUTHWEST CONUS CREATING DELIGHTFUL WEATHER FOR MOST OF THE STATE THIS WEEKEND. EXPECT SLIGHTLY BELOW NORMAL TEMPS SATURDAY AND SLIGHTLY ABOVE NORMAL TEMPS SUNDAY WITH LIGHT WINDS FOR MOST AND OCCASIONAL BREEZES IN THE EASTERN PLAINS SUNDAY. MODELS CONTINUE TO SHOW A 560-565DM UPPER LOW DEVELOPING OFF THE SOUTHERN CALIFORNIA COASTLINE SUNDAY. HOWEVER...THE 06Z MREF/15Z SREF/00Z SUPERENSEMBLE SHOWS CONSIDERABLE UNCERTAINTY WITH THE EVOLUTION OF THE UPPER LOW ONCE IT DEVELOPS OFF THE BAJA. THE POSITION/STRENGTH OF MID/UPPER LEVEL FLOW AHEAD OF THE UPPER LOW WILL GREATLY EFFECT THE LOCATION/STRENGTH OF THE SURFACE LEE TROUGH EXPECTED TO DEVELOP OVER THE EASTERN PLAINS MONDAY THROUGH WEDNESDAY. SINCE THIS RESULTS IN LOW CONFIDENCE WITH RESPECT TO CHANCES OF SHOWERS/STORMS OVER THE STATE...AND SUBSEQUENT SEVERE WEATHER THREAT IN THE EAST...HAVE LEFT THE EXTENDED GUIDANCE RELATIVELY UNCHANGED FOR NOW WITH WIDESPREAD ISOLD POPS. GUYER && .AVIATION... VFR CONDITIONS WILL PREVAIL ACROSS NORTHERN AND CENTRAL NEW MEXICO THROUGH THE NEXT 24 HOURS. WINDS WILL GUST BETWEEN 25 TO 35KT THIS AFTERNOON FROM THE NORTHWEST PLATEAU INTO CENTRAL AND SOUTHEASTERN AREAS OF THE STATE THROUGH EARLY EVENING. A COLD FRONT WILL CONTINUE TO PUSH SOUTH THROUGH THE EASTERN PLAINS THIS AFTERNOON THROUGH TONIGHT CAUSING NORTHERLY WINDS AROUND 20 KNOTS WITH LOCALLY GUSTY CONDITIONS FOR A BRIEF PERIOD DURING FRONTAL PASSAGE. NEXT AVIATION DISCUSSION SCHEDULED FOR 09Z. && .ABQ WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM MDT SATURDAY FOR THE FOLLOWING ZONES...NMZ006-007-013. FREEZE WARNING FROM 3 AM MDT TO 9 AM MDT SATURDAY FOR THE FOLLOWING ZONES...NMZ012-018-020-021. && $$ 44 nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 203 PM MDT FRI MAY 2 2008 .DISCUSSION... 700MB FLOW ALONG WITH SURFACE PRESSURE GRADIENT HAVE RELAXED CONSIDERABLY ACROSS NM TODAY. STRONGEST WINDS RESIDE IN AREAS ALONG AND TO THE EAST OF THE CENTRAL MTN CHAIN AS WELL AS IN FAVORED NW FLOW LOCATIONS SUCH AS KABQ AND KFMN. LATEST WATER VAPOR LOOP SHOWS AN IMPRESSIVE DOUBLE BARREL UPPER CIRCULATION OVER THE CENTRAL PLAINS STATES. SURFACE ANALYSIS SHOWS A 1005MB LOW PRESSURE CENTER OVER NE NEW MEXICO WITH A SECONDARY BLAST OF COLD AIR HEADING SOUTH OUT OF EASTERN COLORADO. LATEST RUC13 ANALYSIS SHOWS A COLD FRONT WILL SURGE SOUTH ACROSS EASTERN NM THIS EVENING AS A 1030MB HIGH PRESSURE BUILDS OVER THE CENTRAL ROCKIES. FREEZING TEMPERATURES ARE A VERY GOOD BET ACROSS MUCH OF THE EASTERN PLAINS ALONG AND NORTH OF I40 SO WILL ISSUE A FREEZE WARNING ACROSS THE NE PLAINS. CONCERNED AGAIN ABOUT FREEZING TEMPS AGAIN ACROSS THE ABQ METRO AREA TONIGHT HOWEVER PRESENCE OF AN EAST WIND IN MET/MOS STATISTICAL NUMBERS BY 12Z COMPLICATES MATTER SO WILL GO WITH ANOTHER SPS. CURRENT RED FLAG WARNING VERIFYING ACROSS MUCH OF THE SANDIA/MANZANO/GALLINAS MOUNTAINS AND THE EAST CENTRAL PLAINS SO WILL LEAVE UNCHANGED THROUGH 01Z. 12Z MODEL SUITE IN EXCELLENT AGREEMENT THAT A WEAK RIDGE/QUASI- ZONAL FLOW WILL DEVELOP OVER THE SOUTHWEST CONUS CREATING DELIGHTFUL WEATHER FOR MOST OF THE STATE THIS WEEKEND. EXPECT SLIGHTLY BELOW NORMAL TEMPS SATURDAY AND SLIGHTLY ABOVE NORMAL TEMPS SUNDAY WITH LIGHT WINDS FOR MOST AND OCCASIONAL BREEZES IN THE EASTERN PLAINS SUNDAY. MODELS CONTINUE TO SHOW A 560-565DM UPPER LOW DEVELOPING OFF THE SOUTHERN CALIFORNIA COASTLINE SUNDAY. HOWEVER...THE 06Z MREF/15Z SREF/00Z SUPERENSEMBLE SHOWS CONSIDERABLE UNCERTAINTY WITH THE EVOLUTION OF THE UPPER LOW ONCE IT DEVELOPS OFF THE BAJA. THE POSITION/STRENGTH OF MID/UPPER LEVEL FLOW AHEAD OF THE UPPER LOW WILL GREATLY EFFECT THE LOCATION/STRENGTH OF THE SURFACE LEE TROUGH EXPECTED TO DEVELOP OVER THE EASTERN PLAINS MONDAY THROUGH WEDNESDAY. SINCE THIS RESULTS IN LOW CONFIDENCE WITH RESPECT TO CHANCES OF SHOWERS/STORMS OVER THE STATE...AND SUBSEQUENT SEVERE WEATHER THREAT IN THE EAST...HAVE LEFT THE EXTENDED GUIDANCE RELATIVELY UNCHANGED FOR NOW WITH WIDESPREAD ISOLD POPS. GUYER && .AVIATION... VFR CONDITIONS WILL PREVAIL ACROSS NORTHERN AND CENTRAL NEW MEXICO THROUGH THE NEXT 24 HOURS. WINDS WILL GUST BETWEEN 25 TO 35KT THIS AFTERNOON FROM THE NORTHWEST PLATEAU INTO CENTRAL AND SOUTHEASTERN AREAS OF THE STATE THROUGH EARLY EVENING. A COLD FRONT WILL CONTINUE TO PUSH SOUTH THROUGH THE EASTERN PLAINS THIS AFTERNOON THROUGH TONIGHT CAUSING NORTHERLY WINDS AROUND 20 KNOTS WITH LOCALLY GUSTY CONDITIONS FOR A BRIEF PERIOD DURING FRONTAL PASSAGE. NEXT AVIATION DISCUSSION SCHEDULED FOR 09Z. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 26 70 35 78 / 0 0 0 0 GALLUP.......................... 19 70 28 76 / 0 0 0 0 GRANTS.......................... 19 70 27 77 / 0 0 0 0 GLENWOOD........................ 42 79 45 82 / 0 0 0 0 CHAMA........................... 15 58 23 67 / 0 0 0 5 LOS ALAMOS...................... 26 64 30 73 / 0 0 0 0 RED RIVER....................... 20 50 35 59 / 0 0 0 5 TAOS............................ 19 62 26 72 / 0 0 0 5 SANTA FE........................ 27 64 27 74 / 0 0 0 0 SANTA FE AIRPORT................ 29 67 36 76 / 0 0 0 0 ESPANOLA........................ 30 69 39 79 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 35 72 46 80 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 30 74 43 82 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 33 70 43 80 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 33 72 43 81 / 0 0 0 0 SOCORRO......................... 38 76 43 83 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 24 64 39 75 / 0 0 0 0 MORIARTY/ESTANCIA............... 28 67 40 78 / 0 0 0 0 CARRIZOZO....................... 37 71 48 80 / 0 0 0 10 RUIDOSO......................... 30 64 46 72 / 0 0 0 10 RATON........................... 23 63 30 75 / 5 0 0 5 LAS VEGAS....................... 26 63 35 74 / 0 0 0 0 ROY............................. 28 62 40 74 / 0 0 0 5 CLAYTON......................... 29 62 39 77 / 5 0 0 10 SANTA ROSA...................... 34 69 41 81 / 0 0 0 10 TUCUMCARI....................... 32 70 42 81 / 0 0 0 10 FORT SUMNER..................... 34 70 41 81 / 0 0 0 10 CLOVIS.......................... 35 69 40 78 / 0 0 0 10 PORTALES........................ 33 70 39 79 / 0 0 0 10 ROSWELL......................... 41 73 44 80 / 0 0 0 10 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ107-108. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 7 AM MDT SATURDAY FOR THE FOLLOWING ZONES...NMZ006-007-013. && $$ GUYER/01 nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 241 PM EDT FRI MAY 2 2008 .SYNOPSIS... THE COMBINED EFFECTS OF A WARM FRONT IN THE VICINITY...AND A SLOWLY APPROACHING COLD FRONT FROM THE WEST...WILL KEEP THE THREAT OF SHOWERS IN THE FORECAST THROUGH MUCH OF THE WEEKEND. A GRADUAL DRYING TREND IS EXPECTED TO BEGIN EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPDATED AS OF 11 AM... SFC WMFNT LOOKS TO BE SOMEWHERE ACRS WRN NY/PA WITH AN ADDN/L SFC BOUNDARY EXTENDING ALONG SRN SHORE OF LK ONTARIO UP INTO THE ADIRONDACKS. A FEW SHOWERS OCCURRING ACRS THE FINGER LKS/MOHAWK VALLEY IN CONJUNCTION WITH WK BNDRY WITH MORE WIDESPREAD AREA OF SHOWERS/ISOLD THUNDER OVR NE OH/NW PA. THIS IS OCCURRING IN VICINITY OF SFC WMFNT AND IN AREA OF ENHANCED H8 JET. WV IMAGERY AND RUC ANALYSIS INDICATES POSSIBLE WK S/WV ALSO EMBEDDED IN FLOW HELPING SPARK OFF THIS AREA OF SHOWERS. MODEL FCSTS INDICATE THIS WV/H8 JET WILL WEAKEN AS IT MVS EAST THIS AFTN...ALTHO LOCATIONS ACROSS THE NW CWA MAY SEE BETTER CHC FOR SHOWERS CLOSER TO DYNAMICS OF FRONTAL BOUNDARY/UL FEATURES. TEMPS ARE RISING INTO THE 50 ACROSS THE WRN ZONES AND INTO THE 60S AS CLOSE AS THE ALLEGHENY PLATEAU WHERE WMFNT IS BEGINNING TO FLEX ITS MUSCLE. STILL SOME QUESTION AS TO HOW MUCH THIS FRONT WIL MV INTO THE AREA. HV NOT TOUCHED FCST MAXES FOR THIS AFTN WITH UNCERTAINTY AND SIGNIFICANT AMNT OF CLD CVR IN PLACE. RH PROGS INDICATE POSSIBILITY OF SOME DRYING THIS AFTN ACRS THE SOUTH SO MAY SEE TEMPS EASILY INTO THE 60S TODAY. THIS MAY HELP SPARK OFF A FEW THUNDERSTORMS THIS AFTN...BUT MODEL SNDGS INDICATE MARGINAL LAPSE RATES UNTIL LATER IN THE DAY WITH SOME COOLING ALOFT. THUS...HV RMVD THUNDER CHCS UNTIL AFTR 18Z AND AT THIS POINT HV DROPPED CHCS TO SLIGHT. HV ALSO LOWERED POPS ACRS THE BOARD...WITH BEST CHCS OVR THE FINGER LAKES BUT STILL BLO 60%. WILL CONTINUE TO MONITOR TEMP TRENDS...WHICH WILL HV IMPACT ON POTENTIAL INSTABILITY FOR THIS AFTN. UPDATED GRIDS AND TEXT PRODUCTS ARE ON THE STREET. PREV DISCUSSION BELOW... SHOWERS AND ISOLATED THUNDERSTORMS ARE MOVING EASTWARD, OUT OF THE FORECAST AREA. DECENT LAYER OF INSTABILITY DEVELOPED NEAR THE WARM FRONT, AS INDICATED BY LAPSE RATES AND K-INDICES. WIDELY SCATTERED ACTIVITY IS EXPECTED THROUGH LATE MORNING. && .SHORT TERM /SATURDAY THROUGH MONDAY/... WARM FRONT WILL HANG NEAR FORECAST AREA FOR MUCH OF THIS PERIOD. CONTINUED WARM ADVECTION WILL PUSH TEMPS INTO THE 60S, ESPECIALLY ON SATURDAY. KEPT WITH THEME OF FORECASTING POPS DRIER THAN MODEL FORECASTS. THERE JUST IS NOT A WHOLE LOT OF ACTIVITY VERIFYING NEAR/WITHIN THE WARM SECTOR. HAVE ADDED A CHC FOR A THUNDERSTORM TODAY, AS LAPSE RATES CONTINUE TO INDICATE SOME POTENTIAL CONVECTION. GRANTED, LAPSE RATES DO NOT CHANGE MUCH THROUGH NEXT 36-48H, SO COULD HAVE ADDED THUNDER TO ALL PERIODS. BUT FELT THAT WOULD BE OVERKILL GIVEN THE SLIGHT CHANCE EACH 12-HOUR WINDOW. SATURDAY CONTINUES TO LOOK LIKE THE MOST INTERESTING DAY FORECAST WISE. NAM AND GFS EACH FORECAST OUR REGION TO BE ON THE CUSP OF THE WARM SECTOR, ESPECIALLY SOUTHWESTERN FA. HOWEVER OPINIONS VARY AS TO HOW MUDDY THE WARM SECTOR WILL BE. APPRECIABLE SUNSHINE COMBINED WITH +10C TO +12C 850H TEMPS WILL SUPPORT 70S WITH EASE. AM STICKING TO CLOUDIER SCENARIO FOR THIS PACKAGE, WHICH INCLUDES A SWATH OF UPPER 60S UP THE LAKE PLAIN AND LOWER 60S EAST OF I-81. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... GENERALLY USED HPC GUIDANCE THRU THE PERIOD WHICH USED BLEND OF ECMWF ENSEMBLE MEAN AND OPERATIONAL ECMWF. BLOCKING PATTERN OVER THE NORTH ATLANTIC WITH CLOSED LOW THAT DEVELOPS OFF COAST OF NOVA SCOTIA. WEAK S/W MOVING THRU UPPER FLOW MAY BRING SMALL CHC FOR SHRA ON TUESDAY INTO WEDS...BEFORE UPPER RIDGE PUSHES EAST FOR WHAT LOOKS LIKE MAINLY DRY DAYS THURS AND FRI. TEMPS THRU THIS PERIOD LOOKS TO BE NEAR NORMAL...WITH HIGHS IN THE LOW TO MID 60S AND MINS GENERALLY IN THE LOW TO MID 40S. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... CEILINGS HAVE IMPROVED TO VFR THIS AFTN, WITH EXCEPTION OF RME WHERE MVFR STILL PERSISTENT WITH LGT SHRA IN THE AREA. ELSEWHERE...COULD SEE A HIT AND MISS SHRA OR SPRINKLE AT ANY OF THE OTHER SITES, BUT WILL BE LGT AND BRIEF. MVFR CONDITIONS WILL DOMINATE TONIGHT WITH WARM FRONT IN THE VICINITY AND ANOTHER SURGE OF LOW LEVEL MOISTURE. COULD EVEN SEE SOME IFR CEILINGS OVERNIGHT, ESP AT HIGHER ELEVATION SITES. BEST CHC FOR ANY SHRA ACTIVITY ACROSS THE NORTH AT SYR AND RME. STILL PLENTY OF MOISTURE AROUND IN THE MORNING, SO CONTINUED WITH MVFR. SE WINDS THIS AFTN AT 10 KTS OR LESS...CONTINUE TONIGHT AND INTO SATURDAY. OUTLOOK... .SATURDAY NGT...APPROACHING COLD FRONT WILL BRING BEST CHC FOR SHOWERS AND VISBY/CEILING RESTRICTIONS SATURDAY EVENING AND INTO THE OVERNIGHT. .SUNDAY THROUGH TUESDAY...IMPROVEMENT TO VFR DURING THE AFTERNOON SUNDAY AS FRONTAL BOUNDARY MOVES EAST OF THE FA. HIGH PRESSURE BRINGS FAIR WEATHER THROUGH TUESDAY. .WEDNESDAY...NEXT FRONT APPROACHES WITH CHC FOR SHRA, POSSIBLE RESTRICTIONS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJP NEAR TERM...PVB SHORT TERM...DJP LONG TERM...JML AVIATION...JML ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 1005 PM EDT SAT MAY 3 2008 .SYNOPSIS... A COLD FRONT ALONG THE OHIO AND PENNSYLVANIA BORDER WILL MOVE TO THE EAST COAST BY MORNING. HIGH PRESSURE OVER THE SOUTHERN PLAIN WILL BEGIN BUILDING INTO THE AREA ON SUNDAY AND THEN MOVE EAST ACROSS THE REGION ON MONDAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA TUESDAY NIGHT. A COLD FRONT WILL THEN SWEEP EAST ACROSS THE FORECAST AREA ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... COLD FRONT APPEARS TO BE ALONG THE OH/PA BORDER AND SHOULD BE EAST OF FORECAST AREA BY MIDNIGHT. A FEW LINGERING SHOWERS REMAIN OVER NW PA ZONES AND THESE ALSO SHOULD BE GONE NEXT COUPLE OF HOURS. OTHER SHOWERS CURRENTLY OVER SOUTHERN LOWER MI BUT LATEST RUC KEEPS THESE N OF LAKE ERIE OVERNIGHT. STILL COULD BE SOME MORE LIGHT SHOWERS OR SPRINKLES E OF KCLE OVERNIGHT AS COLDER AIR ARRIVES ALOFT. WILL PUT LOW POPS IN FOR NE OH AND NW PA OVERNIGHT. CLEARING CURRENTLY MOVING ACROSS LAKE MICHIGAN. EXTRAPOLATION OF THIS CLEARING PUTS IT AT KTOL AROUND 07Z. WILL ADD BECOMING PARTLY CLOUDY TO WESTERN GROUPS FOR LATE TONIGHT. ONLY OTHER CHANGE WILL BE TO NUDGE TEMPS DOWN A TAD IN THE WEST. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/... HIGH PRESSURE BEGIN BUILDING IN ON SUNDAY AND WILL REMAIN OVER THE AREA INTO MONDAY. PARTLY TO MOSTLY SUNNY SKIES TOMORROW AFTERNOON. LITTLE COOLER THAN NORMAL WITH HIGHS IN THE LOW TO MID 50S FAR EAST TO NEAR 60 IN THE WEST. WEAK COLD FRONT DROP SOUTH INTO THE AREA MONDAY NIGHT LIFTING BACK NORTH AS WARM FRONT TUESDAY WITH A COLD FRONT THEN APPROACHING LATE TUESDAY NIGHT. COULD BE SOME SHOWERS WITH THE FRONT MONDAY NIGHT AND TUESDAY BUT WITH THE FRONT BEING RATHER WEAK AND RIDGING ACROSS IT KEPT POPS AT 20 PCT OR LESS. AFTER BELOW NORMAL TEMPERATURES SUNDAY AND SUNDAY NIGHT...A SLIGHT WARM UP WILL PUSH TEMPERATURES BACK TO NEAR NORMAL. HIGHS IN THE 60S ON MONDAY...UPPER 60S AND AROUND 70 ON TUESDAY.&& .LONG TERM /WEDNESDAY THROUGH SATURDAY/... LOW PRESSURE AND ASSOCIATED COLD FRONT EXPECTED TO BE SOMEWHERE NEAR THE AREA ON WED SO WILL CONTINUE CHANCE OF SHRA WHILE BUMPING UP THE POP A BIT MORE. ANOTHER MORE STRONGER LOW SHOULD THEN MOVE UP THE OHIO VALLEY THU THROUGH FRI MAINTAINING REASONING FOR SHRA CHC TO STAY IN FORECAST. GFS LOOKS A LITTLE SLOW IN MOVING LOW OFF EAST COAST SO WILL SHOOT FOR DRY WEATHER LATE FRIDAY NIGHT THROUGH SAT. TEMPS THROUGH THE PERIOD WILL TEND TO RUN A LITTLE BELOW NORMAL. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... LOW PRESSURE AND ASSOCIATED COLD FRONT EXPECTED TO BE SOMEWHERE NEAR THE AREA ON WED SO WILL CONTINUE CHANCE OF SHRA WHILE BUMPING UP THE POP A BIT MORE. ANOTHER MORE STRONGER LOW SHOULD THEN MOVE UP THE OHIO VALLEY THU THROUGH FRI MAINTAINING REASONING FOR SHRA CHC TO STAY IN FORECAST. GFS LOOKS A LITTLE SLOW IN MOVING LOW OFF EAST COAST SO WILL SHOOT FOR DRY WEATHER LATE FRIDAY NIGHT THROUGH SAT. TEMPS THROUGH THE PERIOD WILL TEND TO RUN A LITTLE BELOW NORMAL. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... COLD FRONT CROSSING NE OHIO WITH ONE LAST BATCH OF MVFR SHOWERS AND ISOLATED THUNDER AND A FEW WIND GUSTS TO 30 KTS. WRAP AROUND MOISTURE WILL CROSS THE AREA TONIGHT AND SUNDAY MORN. NW OHIO MAY SEE A FEW LIGHT SHOWERS/SPRINKLES OTHERWISE CEILINGS WILL LIKELY COME DOWN TO MVFR FOR A 4-6 HOUR PERIOD. STRATOCUMULUS WILL LIFT TO VFR (AROUND 4K) SUNDAY MORNING AND CLEARING SHOULD PROCEED FROM NW TO SE AND CU/STRATOCU WILL GRADUALLY DRY UP. OUTLOOK...WEAK COLD FRONT MAY BRUSH THE AREA ON MONDAY OTHERWISE VFR CONDITIONS EXPECTED UNTIL NEXT SIGNIFICANT FRONT WHICH IS EXPECTED ON WEDNESDAY. FRONT MAY BECOME STATIONARY JUST SOUTH OF THE AREA THE SECOND HALF OF THE WEEK AND MVFR OR PERHAPS IFR CONDITIONS MAY OCCUR IF FRONT IS CLOSE ENOUGH AND SHOWERS PERSIST. && .MARINE... SMALL CRAFT CONDITIONS WITH WINDS OF 15 TO 25 KNOTS EXPECTED TONIGHT THEN DECREASE IN WINDS SUNDAY AS HIGH PRESSURE MOVES IN. SOUTH FLOW WILL DEVELOP MONDAY AND GENERALLY CONTINUE THROUGH TUE NIGHT BEFORE VEERING WITH PASSAGE OF COLD FRONT WEDNESDAY. BUT MODELS DIFFER ON LOCATION OF LOW DRAGGING THE COLD FRONT ALONG. WILL OPT FOR A SCENARIO WHERE THE LOW STAYS JUST NORTH OF LAKE ERIE. HIGH PRESSURE MAY RIDGE IN FROM THE NORTH WEDNESDAY NIGHT AND THU FOR A NORTH WIND THAT VEERS TO EAST OR NE THU AS ANOTHER LOW IS EXPECTED TO BE MOVING UP THE OHIO VALLEY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT SUNDAY FOR LEZ142>149. && $$ SYNOPSIS...KUBINA NEAR TERM...KUBINA SHORT TERM...RANDEL LONG TERM...ADAMS AVIATION...KOSARIK MARINE...ADAMS oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 156 AM EDT SAT MAY 3 2008 .SYNOPSIS... A COLD FRONT WILL PUSH ACROSS THE GREAT LAKES AND OHIO VALLEY REGION LATE TONIGHT AND EARLY SATURDAY...BRINGING SHOWERS AND THUNDERSTORMS TO THE REGION. HIGH PRESSURE WILL BUILD OVER THE MIDWEST ON SATURDAY AND WORK INTO THE OHIO VALLEY ON SUNDAY. THE NEXT LOW PRESSURE SYSTEM WITH UNSETTLED WEATHER WILL PASS OVER THE REGION ON WEDNESDAY. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... A DEFINITIVE BACK EDGE OF THE SHOWERS IN ERN CWA WILL HELP THE SCT SHOWERS TO TURN OFF BY MIDNIGHT OVER THE SOUTHEAST. A LULL IN THE ACTIVITY WILL OCCUR AS STRONG STORMS SPARK ALONG THE COLD FRONT IN ILLINOIS AND INDIANA AND SLOWLY MOVE EAST. ANOTHER SWATH OF SHOWERS AND THUNDERSTORMS IS FOUND SOUTH SOUTHWEST OF THE OHVLY IN WRN TN AND KY WHERE THE UPPER LEVEL TROUGH IS NEG TILTING TO PROVIDE A STRONGER BIT OF DYNAMICS TO THIS REGION. NAM IS SHOWING THE LINE OF CONVECTION TO THE WEST DYING OUT AS IT RUNS INTO AN AIRMASS THAT HAS ALREADY BEEN WORKED OVER THIS AFTERNOON. THESE STORMS ARE ALSO GOING TO BE ROBBED OF THE BEST MOISTURE PLUME THAT WILL GET WRUNG OUT SOUTH OF THE AREA. LINE OF CONVECTION WILL FIRE SOUTHWEST OF THE CWA AROUND THE LOUISVILLE AREA LATER THIS EVENING. IT WILL BE THE BEGINNING OF WIDESPREAD CONVECTION THAT NOSES ALONG THE IN/KY BORDER INTO SW OH...SPREADING E AS THE STORMS TRACK FURTHER NE ALONG THE I-71 CORRIDOR. HIGHEST INSTABILITY IS NOTED TO THE WEST WITH BETTER FORCING COMBINING WITH INSTABILITY TO THE SOUTH. ANY STORMS PUSHING THROUGH THE REGION TONIGHT WILL HAVE THE POTENTIAL FOR SEVERE WINDS AS THE STORMS THEMSELVES ARE IN THE MEAN FLOW OF ABOUT 50 MPH ONLY A FEW THOUSAND FEET OFF THE GROUND. COMBINATION OF FORCING AND INSTABILITY COULD RESULT IN INDIVIDUAL SUPERCELLS BUT THIS SCENARIO WEAKENS WITH EACH PASSING HOUR. BACK EDGE OF STORMS SHOULD BE E OF THE I-75 CORRIDOR AT DAYBREAK AND CONTINUE TO MOVE QUICKLY E. && .SHORT TERM /7 AM THIS MORNING THROUGH 6 PM SUNDAY/... GIVEN THE CONVECTIVE NATURE OF PCPN EXPECTED THROUGH THE SHORT TERM PERIOD...HAVE LEANED MORE ON THE OPERATIONAL NAM-WRF...RUC AND SREF MEANS. A COLD FRONT EXTENDED FROM SE MN...SW WISCONSIN...FAR WRN ILLINOIS...THEN TO THE LOWER MS RIVER VLY THIS EVENING. THIS FRONT IS EXPECTED TO REACH A CENTRAL MICHIGAN TO CENTRAL INDIANA POSITION BY 12Z SATURDAY...AND THEN SLOWLY TRAVERSE THE REGION THROUGH SATURDAY EVENING. MODELS CONTINUE TO INDICATE 925 MB-850 MB LOW LVL CONVERGENCE OUT AHEAD OF THE SFC FRONT FOR LATE TONIGHT INTO SATURDAY MORNING. ALSO...THIS CONVERGENCE IS EXPECTED TO BE SUPPLEMENTED BY UPR DIVERGENCE ROTATING NORTHWARD ACRS THE WESTERN GREAT LAKES IN ASSOCIATION WITH AN UPR LVL LOW. LATEST RUC AND NAM-WRF MODELS INDICATE THAT PERHAPS THE BEST LOW LVL FORCING WILL OCCUR OVER THE SW FCST AREA LATE TONIGHT WITH WEAKER FORCING EXPECTED ACRS THE NW CWFA. ATTM...HAVE MAINTAINED 80 POPS ACRS THE ENTIRE WEST CWFA ONIGHT...BUT EVENING FORECAST SHIFT MAY HAVE TO TRIM POPS BACK FOR THE NW IF MODEL TRENDS CONTINUE TO INDICATE WEAKER FORCING THERE. SPC CONTINUES TO KEEP THE WRN HALF OF OUR FCST AREA IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR LATE TONIGHT. THE CHC/S FOR SEVERE WILL DEPENDENT ON HOW MUCH INSTABILITY CAN HOLD TOGETHER AS LINE OF CONVECTION REACHES OUR FCST AREA. IF LINE ARRIVES EARLY ENOUGH...THEN SOME DAMAGING WINDS MAY BE POSSIBLE. OTHERWISE...CONVECTION MAY COME THROUGH THE REGION WITHOUT ANY PROBLEMS. WILL CONTINUE TO MONITOR MESOSCALE AND MODEL TRENDS. OTHERWISE...AM EXPECTING BULK OF PCPN TO MOVE OFF TO THE EAST BY SATURDAY AFTERNOON. THEN...ATTENTION TURNS TOWARD THE COLD FRONT. IF THE ATMOSPHERE CAN DESTABILIZE ENOUGH AFTER BEING WORKED OVER FROM MORNING CONVECTION...THEN SOME SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP. HAVE CONTINUED A 30 TO 40 POP DURING THE AFTERNOON HOURS FOR THIS POSSIBILITY. BY SATURDAY EVENING...WITH THE LOSS OF DAYTIME HEATING...ANY CONVECTIVE ACTIVITY WILL DIMINISH AND/OR MOVE OFF TO THE EAST ALONG THE COLD FRONT. ENTIRE FCST AREA IS EXPECTED TO BE DRY BY MIDNIGHT. SFC HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE REGION AFTER MIDNIGHT. AS FOR TEMPERATURES...THEY WILL BE A LITTLE TRICKY ON SATURDAY DUE CLOUDS AND ANY POSSIBLE INSOLATION BETWEEN CONVECTIVE EVENTS. HAVE RANGED TEMPERATURES FROM THE MID 60S NW TO THE LOWER 70S SE. MUCH COOLER TEMPERATURES ARE EXPECTED BY SUNDAY MORNING WITH LOWS RANGING FROM THE LOWER TO MID 40S. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... MODEL CONSENSUS FAVORING A WEAKER AND CONSEQUENTLY MORE PROGRESSIVE UPR TROF AXIS CROSSING THE ERN GRT LKS SUN MRNG. AT THE SFC...HI PRES EXPANDING INTO THE REGION A LITTLE FASTER THRU THE DAY SUNDAY. GFS/NAM BOTH CONTINUE TO INDICATE A LO LVL THERMAL TROF LAGGING ACRS FCST AREA SUNDAY IN CAA REGIME...BUT GENERALLY WEAKER WITH THIS FEATURE THAN PREV RUNS HAD INDICATED. HAVE THEREFORE CUT BACK ON CU FIELD A BIT FOR SUNDAY AND ALLOWED FOR A BIT MORE SUNSHINE AND SLIGHTLY WARMER TEMPS THAN PREV FCST. APPEARS IDEAL RADIATIONAL COOLING SETUP SUN NIGHT WITH CLR SKIES AND LGT WINDS UNDER CENTER OF HI PRES. TEMPS LIKELY TO BOTTOM OUT IN THE U30S/L40S ON MON MRNG. FIRST HALF OF THE WORKWEEK WILL BE HIGHLIGHTED BY SFC HI PRES AND MEAN NORTHWEST FLO ALOFT AS DEEP UPR LO SPINS ACRS JAMES BAY REGION OF CANADA. SVRL WEAK MID LVL DISTURBANCES WILL RIDE AROUND THE BASE OF THE MEAN TROF AND PASS THRU THE GRT LKS AND INTO NEW ENGLAND. ONE OF THESE DISTURBANCES WILL DROP ACRS THIS AREA LATE MON NIGHT AND TUES REFLECTED BY A WEAK COLD FRONT AT THE SFC. BOTH 12Z GFS/NAM SOLNS ARE MORE AMPLIFIED AND FURTHER SOUTH WITH AFOREMENTIONED UPR LO AND CONSEQUENTLY STRONGER WITH COLD FRONT AS IT DROP INTO THE ERN GRT LKS. HAVE TRENDED TOWARDS WEAKER 00Z ECMWF/HPC SOLN WHICH FAVORS A WEAKER COLD FRONT WASHING OUT JUST NORTHEAST OF REGION TUES AS IT RUNS INTO RELATIVELY DRY AIRMASS WITH LITTLE IN WAY OF AVAIL FORCING. HAVE ALSO LEANED HEAVILY TOWARDS 00Z ECMWF/HPC SOLN FOR REMAINDER OF EXTENDED WRT ENERGY BEING EJECTED NORTHEAST INTO CNTRL PLAINS FROM DEEP WRN CONUS UPR TROF BY MIDWEEK. SFC LO WILL DVLP IN THE SRN PLAINS WED AFTN AND LIFT NORTHEAST INTO THE GRT LKS BY FRI. WILL INTRODUCE CHANCE POPS LATE WED NIGHT AND PARTICULARLY INTO THURS AS WARM FRONT RISE NORTH INTO THE OH VLY. THE POSSIBILITY FOR SHRA/TSTMS WILL PERSIST INTO FRI AS REGION MOVES INTO WARM SECTOR AHEAD OF TRAILING COLD FRONT. HAVE BUMPED TEMPS UP A FEW DEG FROM PREV FCST FOR MON-WED AS APPEARS EXPANSION OF MID LVL RIDGE WILL ALLOW FOR A FASTER RECOVERY OF TEMPS TO AROUND 70 OR HIGHER FROM TUES FORWARD. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS ARE EXPANDING IN COVERAGE ACROSS KENTUCKY AND INDIANA AHEAD OF AN ADVANCING COLD FRONT. LARGE AREA OF RAIN MOVING INTO SW OHIO WILL CONTINUE PUSHING TOWARD KILN AND POSSIBLY CENTRAL OHIO WITHIN A FEW HOURS. MAIN CONCERN IS THE THUNDERSTORM ACTIVITY DEVELOPING BEHIND THIS PRECIP...CURRENTLY ACROSS CENTRAL AND SOUTHERN INDIANA. NAM AND GFS BOTH INCREASE THIS PRECIP IN COVERAGE AS INTENSIFYING LOW LEVEL CONVERGENCE PUSHES INTO OHIO AROUND 09Z. BIG QUESTION IS HOW MUCH INSTBY WILL BE IN PLACE WHEN THIS ACTIVITY COMES THROUGH. WITH STRONG LOW AND MIDLEVEL SHEAR...JUST A FEW HUNDRED JOULES OF CAPE COULD RESULT IN SOME STRONG STORMS LATE TONIGHT...HOWEVER IF INSTBY IS LESS THAN THIS...PROBABLY WONT SEE MUCH IN THE WAY OF THUNDER AT ALL. WILL STILL HOLD OFF ON INTRODUCING PREVAILING OR TEMPO THUNDER TO THE TAFS SINCE INSTBY IS SUCH AN UNKNOWN...BUT CONVECTIVE TRENDS WILL BE MONITORED CLOSELY OVERNIGHT. FOLLOWED PRETTY CLOSELY TO THE NAM FOR TIMING THIS LINE...COMING THROUGH KCVG AROUND 09Z AND KCMH AROUND 12Z. AFTER FRONT PASSES...SHOULD SEE SOME QUICK CLEARING BEFORE MIDLEVEL IMPULSE BRINGS ANOTHER CHANCE FOR AFTERNOON SHOWERS AND A BKN MIDLEVEL DECK. WINDS WILL BE GUSTY FROM THE SOUTHWEST DURING THE AFTERNOON...THEN WILL DIE DOWN AFTER SUNSET. MOISTURE CLEARS FROM WEST TO EAST AFTER 00Z. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED THROUGH WEDNESDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...FRANKS NEAR TERM...FRANKS SHORT TERM...HICKMAN LONG TERM...RYAN AVIATION...HAWBLITZEL oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 151 PM EDT FRI MAY 2 2008 .SYNOPSIS... WARM SOUTHWEST FLOW CONTINUES FOR ONE MORE DAY. A COLD FRONT CROSSES THE AREA WITH SHOWERS AND THUNDER SATURDAY...FOLLOWED BY COOLER WEATHER SUNDAY. HIGH PRESSURE IN CHARGE SUNDAY NIGHT THROUGH TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... FORECAST ON TRACK SAVE TO UP WIND GUSTS THROUGH SAT BASED ON RUC ALGORITHM PER GOOD MIXING. ALSO ADJUSTED CLOUDS AND DEW POINTS /MOSTLY A LITTLE LOWER ON BOTH/ FOR THIS AFTERNOON. REST SAME AS HIGHS TODAY LOOK GOOD... THOUGH GFS SEEMS A BIT BULLISH ON MID LEVEL MOISTURE...MODELS ARE IN PRETTY GOOD AGREEMENT EVEN ON DETAILS TODAY THROUGH TONIGHT...WITH CWA REMAINING IN WARM SECTOR WELL OUT AHEAD OF APPROACHING COLD FRONT. WARM SOUTHWEST FLOW CONTINUES FOR ONE MORE DAY...WITH INCREMENTALLY HIGHER DEW POINTS YET ALSO TEMPERATURES. THOUGH MIXING LOOKS TO OCCUR ABOUT AS WELL AS THURSDAY...850MB WINDS WILL NOT HAVE QUITE AS MUCH ZING /ABOUT 20 TO 25 KTS AT 850MB TODAY VERSUS 30 TO 35 KTS YESTERDAY/. THAT BEING SAID...STILL A GENERALLY BREEZY DAY DURING PEAK MIXING...AND AS WITH THURSDAY...MARGINAL FIRE WEATHER CONCERN EXISTS /SEE FIRE WEATHER SECTION OF AFD/. WEAK VORTS MOVING THROUGH SOUTHWEST FLOW...THE MOST OBVIOUS OF WHICH REACHES FAR WESTERN ZONES AROUND 00Z-03Z THIS EVENING...COULD TOUCH OFF A FEW THUNDERSTORMS IN OUR NE KY AND SE OH ZONES. HOWEVER...WITH DEW POINTS STILL ONLY IN THE 40S UNTIL LATE TONIGHT /DRIER MAV GUIDANCE PREFERRED/...COVERAGE OF CONVECTION LOOKS MEAGER EVEN IN THE FAR WESTERN ZONES...AND THUS I AM LOOKING FOR DRY WEATHER TO LAST UNTIL AT LEAST SATURDAY MORNING FOR VAST MAJORITY OF THE AREA. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... MODELS IN VERY GOOD AGREEMENT ON THE TIMING OF THE COLD FRONT SATURDAY AFTERNOON AND EVENING ACROSS OUR AREA. FRONT REACHES OUR WESTERN BORDER AROUND MID AFTERNOON SATURDAY...AND EXITS OUR AREA AROUND MIDNIGHT. THE MAIN SHORT WAVE SUPPORTING THE COLD FRONT ACTUALLY LIFTS NORTH AND WEST OF THE AREA SATURDAY MORNING...SO THAT INITIAL BAND OF CONVECTION PRECEDING THE COLD FRONT WASHES OUT FOR THE MOST PART AS IT CROSSES THE OHIO RIVER DURING SATURDAY MORNING. THE BIG QUESTION THEN IS HOW MUCH REGENERATION ALONG THE COLD FRONT SATURDAY AFTERNOON. WITH UPPER SUPPORT DIMINISHING...MUCH DEPENDS ON HOW MUCH SUNSHINE AND HEATING WE GET AHEAD OF THE FRONT. WHILE UNCERTAIN AS TO HOW MUCH CLOUD DEBRIS LINGERS...GOOD LOW LEVEL CONVERGENCE...GOOD MOISTURE FEED AND TIME OF DAY STRONGLY SUGGESTS A LINE OF CONVECTION ALONG THE FRONT AS IT CROSSES OUR AREA SATURDAY AFTERNOON AND EVENING. THUS...HAVE GONE ON THE HIGH SIDE OF GUIDANCE WITH LIKELY POPS. ALSO GOING ON THE WARMER SIDE OF GUIDANCE SATURDAY. WITH HIGH PRESSURE BUILDING IN RAPIDLY LATER SATURDAY NIGHT AND SUNDAY...HAVE ENDED POST FRONTAL SHOWERS MORE QUICKLY THAN MODELS SUGGEST...WITH ANY LINGERING SHOWERS IN THE MOUNTAINS ENDING SUNDAY MORNING. TEMPS FALL BACK TO NEAR SEASONAL VALUES SUNDAY. NO FROST/FREEZE SEEN WITH AIR MASS FOLLOWING THE COLD FRONT. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE DOMINATES MONDAY WITH PLENTY OF SUNSHINE AND A WARMING TREND. WEAK COLD FRONT TRIES TO DIP DOWN FROM THE NORTH TUESDAY...BUT THE UPPER FLOW BEGINS TO BACK TO A MORE WESTERLY FLOW AHEAD OF THE NEXT WEATHER SYSTEM. IN ANY CASE...LITTLE MOISTURE RETURN AND UPPER SUPPORT FOR THE FRONT EVEN IF IT DOES MAKE IT INTO OUR NORTHERN AREAS LATER TUESDAY BEFORE WASHING OUT. THUS...NO POPS. MAIN MODEL DISCREPANCIES ARE FOR THE NEXT MAIN SYSTEM AFFECTING US MID TO LATER WEEK. THE GFS IS FASTEST AS IT LIFTS UPPER LOW OUT OF THE SOUTHWESTERN U.S. MUCH MORE QUICKLY THAN THE ECMWF. GIVEN THE GFS BIAS OF BEING FAST ON THESE SYSTEMS...HAVE TRENDED WITH HPC TOWARD THE SLOWER SOLUTION. THIS BRINGS A CHANCE OF SHOWERS MAINLY THURSDAY NIGHT AND FRIDAY. LOOK FOR ABOVE NORMAL TEMPS THIS PERIOD. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... WE REMAIN IN THE WARM SECTOR OF SYSTEM...WELL OUT AHEAD OF APPROACHING COLD FRONT THAT WILL NOT ARRIVE UNTIL DURING THE DAY SATURDAY. UPPER LEVEL DISTURBANCES WILL BRING PATCHY ALTOCU THROUGH THE AREA...BUT NOTHING MORE THAN A FEW THUNDERSTORMS IN SOUTHEAST OHIO THIS AFTERNOON AND EVENING...WELL AWAY FROM THE OHIO RIVER. FR WILL PREVAIL THROUGH 12Z SATURDAY...THOUGH CIGS WILL BEGIN TO LOWER SATURDAY MORNING. SHOWERS AND A FEW THUNDERSTORMS WILL ARRIVE FROM THE W...GETTING TO CENTRAL TERMINALS /CKB AND CRW/ NEAR THE END OF THE PERIOD /18Z/. CONDITIONS WILL LOWER TO MVFR AND EVEN IFR IN HEAVIER RAINFALL AS THIS HAPPENS. AVIATION OUTLOOK /AFTER 18Z SATURDAY/...COLD FRONT WITH RAIN AND THUNDER...AND POSSIBLE IFR...INTO SATURDAY NIGHT. && .FIRE WEATHER... FORECAST AS OF LATE MORNING REMAINS ON TRACK. FWS ISSUED FOR MIDDLE MTN SOUTH. REST SAME... THOUGH DEW POINTS WILL BE SEVERAL DEGREES HIGHER TODAY COMPARED TO THURSDAY...TEMPERATURES WILL ALSO BE HIGHER WITH OUR CONTINUED SOUTHWEST FLOW...AND THUS MINIMUM RELATIVE HUMIDITY WILL STILL DIP INTO THE MID TO UPPER 20S FOR A GOOD CHUNK OF THE AREA /DRIEST IN SOUTHERN WV AND SOUTHWEST VA/. MID LEVEL CLOUDS WILL HELP KEEP THINGS IN CHECK HOWEVER...ESPECIALLY NORTHWESTERN ZONES /OHIO/. AS FOR WINDS...THOUGH GOOD MIXING WILL OCCUR AGAIN THIS AFTERNOON...MID LEVEL WINDS WILL NOT BE QUITE AS STRONG AS THURSDAY. SUSTAINED WINDS OF 10-14 MPH WITH GUSTS OF 20-25 MPH ARE EXPECTED DURING PEAK MIXING THIS AFTERNOON. SO OVERALL...RED FLAG CRITERIA WILL AGAIN BE APPROACHED IN PARTS OF THE AREA BUT NOT BREACHED. HOWEVER...WE WILL HAVE TO MONITOR THE SITUATION CLOSELY...ESPECIALLY WITH 10 HOUR FUEL MOISTURE LEVELS NOW DROPPING INTO THE SINGLE DIGITS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...MDP/JMV NEAR TERM...MDP/TRM SHORT TERM...JMV LONG TERM...JMV AVIATION...TRM FIRE WEATHER...MDP/TRM oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1119 AM EDT FRI MAY 2 2008 .SYNOPSIS... WARM SOUTHWEST FLOW CONTINUES FOR ONE MORE DAY. A COLD FRONT CROSSES THE AREA WITH SHOWERS AND THUNDER SATURDAY...FOLLOWED BY COOLER WEATHER SUNDAY. HIGH PRESSURE IN CHARGE SUNDAY NIGHT THROUGH TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... FORECAST ON TRACK SAVE TO UP WIND GUSTS THROUGH SAT BASED ON RUC ALGORITHM PER GOOD MIXING. ALSO ADJUSTED CLOUDS AND DEW POINTS /MOSTLY A LITTLE LOWER ON BOTH/ FOR THIS AFTERNOON. REST SAME AS HIGHS TODAY LOOK GOOD... THOUGH GFS SEEMS A BIT BULLISH ON MID LEVEL MOISTURE...MODELS ARE IN PRETTY GOOD AGREEMENT EVEN ON DETAILS TODAY THROUGH TONIGHT...WITH CWA REMAINING IN WARM SECTOR WELL OUT AHEAD OF APPROACHING COLD FRONT. WARM SOUTHWEST FLOW CONTINUES FOR ONE MORE DAY...WITH INCREMENTALLY HIGHER DEW POINTS YET ALSO TEMPERATURES. THOUGH MIXING LOOKS TO OCCUR ABOUT AS WELL AS THURSDAY...850MB WINDS WILL NOT HAVE QUITE AS MUCH ZING /ABOUT 20 TO 25 KTS AT 850MB TODAY VERSUS 30 TO 35 KTS YESTERDAY/. THAT BEING SAID...STILL A GENERALLY BREEZY DAY DURING PEAK MIXING...AND AS WITH THURSDAY...MARGINAL FIRE WEATHER CONCERN EXISTS /SEE FIRE WEATHER SECTION OF AFD/. WEAK VORTS MOVING THROUGH SOUTHWEST FLOW...THE MOST OBVIOUS OF WHICH REACHES FAR WESTERN ZONES AROUND 00Z-03Z THIS EVENING...COULD TOUCH OFF A FEW THUNDERSTORMS IN OUR NE KY AND SE OH ZONES. HOWEVER...WITH DEW POINTS STILL ONLY IN THE 40S UNTIL LATE TONIGHT /DRIER MAV GUIDANCE PREFERRED/...COVERAGE OF CONVECTION LOOKS MEAGER EVEN IN THE FAR WESTERN ZONES...AND THUS I AM LOOKING FOR DRY WEATHER TO LAST UNTIL AT LEAST SATURDAY MORNING FOR VAST MAJORITY OF THE AREA. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... MODELS IN VERY GOOD AGREEMENT ON THE TIMING OF THE COLD FRONT SATURDAY AFTERNOON AND EVENING ACROSS OUR AREA. FRONT REACHES OUR WESTERN BORDER AROUND MID AFTERNOON SATURDAY...AND EXITS OUR AREA AROUND MIDNIGHT. THE MAIN SHORT WAVE SUPPORTING THE COLD FRONT ACTUALLY LIFTS NORTH AND WEST OF THE AREA SATURDAY MORNING...SO THAT INITIAL BAND OF CONVECTION PRECEDING THE COLD FRONT WASHES OUT FOR THE MOST PART AS IT CROSSES THE OHIO RIVER DURING SATURDAY MORNING. THE BIG QUESTION THEN IS HOW MUCH REGENERATION ALONG THE COLD FRONT SATURDAY AFTERNOON. WITH UPPER SUPPORT DIMINISHING...MUCH DEPENDS ON HOW MUCH SUNSHINE AND HEATING WE GET AHEAD OF THE FRONT. WHILE UNCERTAIN AS TO HOW MUCH CLOUD DEBRIS LINGERS...GOOD LOW LEVEL CONVERGENCE...GOOD MOISTURE FEED AND TIME OF DAY STRONGLY SUGGESTS A LINE OF CONVECTION ALONG THE FRONT AS IT CROSSES OUR AREA SATURDAY AFTERNOON AND EVENING. THUS...HAVE GONE ON THE HIGH SIDE OF GUIDANCE WITH LIKELY POPS. ALSO GOING ON THE WARMER SIDE OF GUIDANCE SATURDAY. WITH HIGH PRESSURE BUILDING IN RAPIDLY LATER SATURDAY NIGHT AND SUNDAY...HAVE ENDED POST FRONTAL SHOWERS MORE QUICKLY THAN MODELS SUGGEST...WITH ANY LINGERING SHOWERS IN THE MOUNTAINS ENDING SUNDAY MORNING. TEMPS FALL BACK TO NEAR SEASONAL VALUES SUNDAY. NO FROST/FREEZE SEEN WITH AIR MASS FOLLOWING THE COLD FRONT. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... HIGH PRESSURE DOMINATES MONDAY WITH PLENTY OF SUNSHINE AND A WARMING TREND. WEAK COLD FRONT TRIES TO DIP DOWN FROM THE NORTH TUESDAY...BUT THE UPPER FLOW BEGINS TO BACK TO A MORE WESTERLY FLOW AHEAD OF THE NEXT WEATHER SYSTEM. IN ANY CASE...LITTLE MOISTURE RETURN AND UPPER SUPPORT FOR THE FRONT EVEN IF IT DOES MAKE IT INTO OUR NORTHERN AREAS LATER TUESDAY BEFORE WASHING OUT. THUS...NO POPS. MAIN MODEL DISCREPANCIES ARE FOR THE NEXT MAIN SYSTEM AFFECTING US MID TO LATER WEEK. THE GFS IS FASTEST AS IT LIFTS UPPER LOW OUT OF THE SOUTHWESTERN U.S. MUCH MORE QUICKLY THAN THE ECMWF. GIVEN THE GFS BIAS OF BEING FAST ON THESE SYSTEMS...HAVE TRENDED WITH HPC TOWARD THE SLOWER SOLUTION. THIS BRINGS A CHANCE OF SHOWERS MAINLY THURSDAY NIGHT AND FRIDAY. LOOK FOR ABOVE NORMAL TEMPS THIS PERIOD. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... WE REMAIN IN THE WARM SECTOR OF SYSTEM...WELL OUT AHEAD OF APPROACHING COLD FRONT THAT WILL NOT ARRIVE UNTIL DURING THE DAY SATURDAY. UPPER LEVEL DISTURBANCES COULD CAUSE A FEW THUNDERSTORMS THIS AFTERNOON AND EVENING...BUT COVERAGE WILL BE ISOLATED AND IT SHOULD BE LIMITED TO WEST OF THE KHTS AND KPKB TERMINALS. WITH ONLY MID TO HIGH CLOUDS AT TIMES...VFR WILL PREVAIL THROUGH 12Z SATURDAY...THOUGH CIGS WILL BEGIN TO LOWER SATURDAY MORNING. AVIATION OUTLOOK /AFTER 12Z SATURDAY/...COLD FRONT WITH RAIN AND THUNDER...AND POSSIBLE IFR...SATURDAY AND SATURDAY NIGHT. && .FIRE WEATHER... FORECAST AS OF LATE MORNING REMAINS ON TRACK. FWS ISSUED FOR MIDDLE MTN SOUTH. REST SAME... THOUGH DEW POINTS WILL BE SEVERAL DEGREES HIGHER TODAY COMPARED TO THURSDAY...TEMPERATURES WILL ALSO BE HIGHER WITH OUR CONTINUED SOUTHWEST FLOW...AND THUS MINIMUM RELATIVE HUMIDITY WILL STILL DIP INTO THE MID TO UPPER 20S FOR A GOOD CHUNK OF THE AREA /DRIEST IN SOUTHERN WV AND SOUTHWEST VA/. MID LEVEL CLOUDS WILL HELP KEEP THINGS IN CHECK HOWEVER...ESPECIALLY NORTHWESTERN ZONES /OHIO/. AS FOR WINDS...THOUGH GOOD MIXING WILL OCCUR AGAIN THIS AFTERNOON...MID LEVEL WINDS WILL NOT BE QUITE AS STRONG AS THURSDAY. SUSTAINED WINDS OF 10-14 MPH WITH GUSTS OF 20-25 MPH ARE EXPECTED DURING PEAK MIXING THIS AFTERNOON. SO OVERALL...RED FLAG CRITERIA WILL AGAIN BE APPROACHED IN PARTS OF THE AREA BUT NOT BREACHED. HOWEVER...WE WILL HAVE TO MONITOR THE SITUATION CLOSELY...ESPECIALLY WITH 10 HOUR FUEL MOISTURE LEVELS NOW DROPPING INTO THE SINGLE DIGITS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...MDP/JMV NEAR TERM...MDP/TRM SHORT TERM...JMV LONG TERM...JMV AVIATION...MDP FIRE WEATHER...MDP/TRM oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 521 PM CDT FRI MAY 2 2008 .UPDATE...SURFACE OBSERVATIONS AND TRENDS IN THE SHORT RANGE MODELS...INCLUDING THE RUC...SUPPORT A WIND ADVISORY FOR A LARGE PART OF NORTHERN AND WESTERN OKLAHOMA THIS EVENING. THE BACK SIDE OF THE LARGE UPPER TROUGH AFFECTING THE CENTRAL UNITED STATES...WILL SWING THROUGH OKLAHOMA AND NORTH TEXAS OVERNIGHT. HEIGHT FALLS BENEATH THIS FEATURE WILL BE SUPPORTED BY A SECOND COLD FRONT...THIS TIME PULLING IN MUCH COOLER AIR FROM THE NORTH RATHER THAN THE WEST. WITH SEVERAL HOURS OF DEEP MIXING STILL POSSIBLE...AND STRONG DOWNWARD MOTION ASSOCIATED WITH COLD ADVECTION...WOULD EXPECT THE 45 TO 50 MPH GUSTS IN NORTHWEST OKLAHOMA LATE THIS AFTERNOON TO SPREAD SOUTH AND EAST DURING THE EVENING. MEANWHILE...HUMIDITY WILL GRADUALLY RECOVER IN THE RED FLAG WARNING COUNTIES. WILL KEEP THE WARNING GOING BASED ON EXCESSIVE WINDS AND AVAILABLE FUELS...BUT WILL ALLOW IT TO EXPIRE NATURALLY AT 7 PM. && BURKE/11 && .PREV DISCUSSION... /ISSUED 246 PM CDT FRI MAY 2 2008/ DISCUSSION... UPPER STORM SYSTEM IS MOVING THROUGH NEBRASKA TODAY WITH THE SURFACE LOW MOVING INTO IOWA. SOME OF THE MID LEVEL CLOUDS THAT DEVELOPED THIS AFTERNOON IN THE NORTHWEST MAY CONTINUE TO AFFECT NORTHERN OKLAHOMA THIS EVENING...BUT OTHERWISE MOSTLY CLEAR SKIES ARE ANTICIPATED. TEMPERATURES WILL FALL TO THE MID 30S IN SOME OF THE TYPICAL COOL SPOTS AROUND THE AREA. A MILD AND DRY WEEKEND IS EXPECTED. THE NEXT STORM SYSTEM BEGINS TO TAKE SHAPE IN THE SOUTHWESTERN UNITED STATES. RETURNING MOISTURE AHEAD OF THIS SYSTEM STARTS SPREADING NORTH INTO THE AREA ON MONDAY AND ISENTROPIC LIFT IS PROGGED TO BE SUFFICIENT FOR SOME PRECIPITATION. THE CHANCE FOR SHOWERS/STORMS CONTINUE THROUGH WEDNESDAY NIGHT AS THE SOUTHWESTERN STORM SYSTEM APPROACHES AND MOVES THROUGH THE AREA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 42 68 41 76 / 10 0 0 0 HOBART OK 40 68 42 77 / 10 0 0 0 WICHITA FALLS TX 43 71 45 78 / 10 0 0 0 GAGE OK 34 67 37 78 / 0 0 0 0 PONCA CITY OK 41 63 38 74 / 10 0 0 0 DURANT OK 49 71 48 77 / 10 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...WIND ADVISORY UNTIL 1 AM CDT SATURDAY FOR OKZ016>018-021>024-034- 035. RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR OKZ004-005-009- 010. WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR OKZ004>007- 009>012-014-015. TX...NONE. && $$ ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 1028 AM CDT SAT MAY 3 2008 .UPDATE... CURRENT FCST IS IN GOOD SHAPE...WITH HIGH PRESSURE PROVIDING CLEAR SKIES. ERN PART OF CWA STILL SEEING SOME BRISK WINDS...BUT THOSE SHOULD SLOWLY DIMINISH AS SFC GRADIENT RELAXES. FCST 925MB AND 850MB TEMPS MIX DOWN TO CURRENT FCST HIGHS...SO THOSE ALSO LOOK IN GOOD SHAPE. NO NEED TO RESEND WORDED ZONE FCST PACKAGE ATTM. && .PREV DISCUSSION... .SHORT TERM...TODAY THROUGH MONDAY FORECAST CHALLENGES INCLUDE TEMPERATURES AND DEW POINT TEMPERATURES. CURRENTLY...HIGH PRESSURE AT THE SURFACE IS BUILDING INTO THE FORECAST AREA. WINDS ARE SUBSIDING AND SKIES HAVE CLEARED. ONE NOTE OF INTEREST IS THE EXTREMELY DRY BOUNDARY LAYER AIR WORKING INTO THE DAKOTAS AT THIS TIME. THE MODELS /INCLUDING THE RUC/ DO NOT APPEAR TO BE HANDLING THE DEGREE OF DRYNESS OVER THE AREA RIGHT NOW...WHICH LEADS ONE TO CALL INTO QUESTION THEIR ABILITY TO ACCURATELY FORECAST THE DEGREE OF DRYNESS DURING THE DAY TODAY. THEREFORE...DID RATCHET DOWN MAV GUIDANCE DEW POINTS FOR TODAY. THE PRESSURE GRADIENT REALLY RELAXES TODAY...ALLOWING NORTH WINDS TO TURN MORE WESTERLY BY THIS AFTERNOON AND DECREASING TO 5 TO 15 MPH OVER MOST OF THE FORECAST AREA. PERHAPS A LITTLE BIT STRONGER OUT EAST WHERE THE PRESSURE GRADIENT WILL HANG ON THE LONGEST TODAY. WITH HUDSON BAY CLOSED UPPER LOW SITTING AND SPINNING IN PLACE OVER CANADA FOR THE NEXT COUPLE OF DAYS...JET-LEVEL WINDS ALOFT WILL TAKE ON PREDOMINANTLY NWRLY FLOW...STEERING A COUPLE OF WEAK AND RATHER MOISTURE STARVED UPPER WAVES THROUGH THE NORTHERN PLAINS BETWEEN TONIGHT AND MONDAY. THESE WAVES WILL LIKELY ALSO UNDERGO SOME SHEARING/WEAKENING AS THEY WORK THROUGH THE REGION. AS SUCH...CONTINUING WITH A DRY FORECAST FOR TODAY THROUGH MONDAY. 850HPA TEMPERATURES BETWEEN TODAY AND MONDAY WILL WARM FROM APPX +5C TO +11C. THIS TRANSLATES INTO A 10 TO 20 DEGREE WARMING OF HIGH TEMPERATURES OVER THE NEXT THREE DAYS. THE TEMPERATURE WILD CARD RIGHT NOW IS THE TUG OF WAR THAT WILL EXIST THROUGHOUT THE FORECAST AREA BETWEEN BOUNDARY LAYER EVAPOTRANSPIRED MOISTURE /WHICH WOULD WORK TO KEEP TEMPERATURES FROM SKY-ROCKETING/ AS THE REGION IS BEGINNING TO GREEN UP SOME...AND THE MARKEDLY DRY AIR THAT HAS BEEN LEFT OVER THE REGION IN THE WAKE OF YESTERDAY`S IMPRESSIVE SPRING STORM SYSTEM /WHICH WOULD WORK TO HELP WARM THE AIRMASS NOW IN PLACE QUITE EFFICIENTLY/. SNOW COVER WILL NOT PLAY ALL THAT MUCH OF A ROLE AS SATELLITE IMAGERY REVEALS ALL THE SNOW PACK IS WELL WEST OF THIS FORECAST AREA OVER WESTERN SOUTH DAKOTA. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY THE MODELS AND GFS ENSEMBLES SHOW GREAT AGREEMENT EARLY ON IN THE PERIOD WITH THE WEATHER FEATURES AFFECTING THE REGION FOR MONDAY NIGHT THROUGH WEDNESDAY NIGHT AND THEN DIVERGE TOWARDS THE END OF THE PERIOD. FIRST OFF...A SHORT WAVE TROUGH AND ITS ASSOCIATED SURFACE LOW PRESSURE AREA AND TRAILING COLD FRONT WILL DROP ACROSS THE REGION MONDAY NIGHT AND EARLY TUESDAY. MODELS DONT INDICATE MUCH MOISTURE AVAILABLE WITH THIS SYSTEM WITH DEWPOINTS MAINLY IN THE MID 40S ALONG WITH LITTLE CAPE ALONG WITH DRY AIR IN THE LOW AND INTO THE MID LEVELS. WHEN THIS SURFACE LOW AND COLD FRONT MOVES THROUGH...IT SHOULD BE AT A MORE UNFAVORABLE TIME FOR CONVECTION TO DEVELOP AT NIGHT IN THE EARLY MORNING. THUS...JUST HAVE IN A 20 POP FOR LIGHT SHOWERS ON TUESDAY. OTHERWISE...THE MODELS THEN SHOW ANOTHER MUCH MORE SIGNIFICANT UPPER LOW/TROUGH AND SURFACE LOW PRESSURE AREA MOVING ACROSS THE CENTRAL PLAINS ON WEDNESDAY AND THURSDAY. THEY INDICATE NO PRECIPITATION FOR OUR AREA WITH THIS SYSTEM AS IT TREKS ACROSS TO THE SOUTH. THUS...REMOVED POPS FOR WEDNESDAY AND WEDNESDAY NIGHT FOR OUR CWA. AFTER THIS...THE GFS AND EC DIVERGE WITH THE NEXT TROUGH MOVING IN FROM THE WEST. THE GFS WAS MUCH STRONGER WITH A TROUGH MOVING INTO AND AFFECTING THE REGION BY FRIDAY WHILE THE EC WAS FARTHER NORTH...FASTER AND WEAKER WITH THIS TROUGH. LEFT THE FORECAST AS IS AT THIS POINT TO SEE WHAT LATER MODELS RUNS HAVE TO BRING TO MAYBE TAKE POPS OUT OF THE FORECAST. && .AVIATION... VFR SKIES ARE EXPECTED THROUGH 12Z SUNDAY WITH UNRESTRICTED VISIBILITIES AND NO SIGNIFICANT WEATHER EXPECTED. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...HINTZ SHORT TERM...DORN LONG TERM...MOHR AVIATION...MOHR WEATHER.GOV/ABERDEEN sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 415 AM CDT SAT MAY 3 2008 .SHORT TERM...TODAY THROUGH MONDAY FORECAST CHALLENGES INCLUDE TEMPERATURES AND DEW POINT TEMPERATURES. CURRENTLY...HIGH PRESSURE AT THE SURFACE IS BUILDING INTO THE FORECAST AREA. WINDS ARE SUBSIDING AND SKIES HAVE CLEARED. ONE NOTE OF INTEREST IS THE EXTREMELY DRY BOUNDARY LAYER AIR WORKING INTO THE DAKOTAS AT THIS TIME. THE MODELS /INCLUDING THE RUC/ DO NOT APPEAR TO BE HANDLING THE DEGREE OF DRYNESS OVER THE AREA RIGHT NOW...WHICH LEADS ONE TO CALL INTO QUESTION THEIR ABILITY TO ACCURATELY FORECAST THE DEGREE OF DRYNESS DURING THE DAY TODAY. THEREFORE...DID RATCHET DOWN MAV GUIDANCE DEW POINTS FOR TODAY. THE PRESSURE GRADIENT REALLY RELAXES TODAY...ALLOWING NORTH WINDS TO TURN MORE WESTERLY BY THIS AFTERNOON AND DECREASING TO 5 TO 15 MPH OVER MOST OF THE FORECAST AREA. PERHAPS A LITTLE BIT STRONGER OUT EAST WHERE THE PRESSURE GRADIENT WILL HANG ON THE LONGEST TODAY. WITH HUDSON BAY CLOSED UPPER LOW SITTING AND SPINNING IN PLACE OVER CANADA FOR THE NEXT COUPLE OF DAYS...JET-LEVEL WINDS ALOFT WILL TAKE ON PREDOMINANTLY NWRLY FLOW...STEERING A COUPLE OF WEAK AND RATHER MOISTURE STARVED UPPER WAVES THROUGH THE NORTHERN PLAINS BETWEEN TONIGHT AND MONDAY. THESE WAVES WILL LIKELY ALSO UNDERGO SOME SHEARING/WEAKENING AS THEY WORK THROUGH THE REGION. AS SUCH...CONTINUING WITH A DRY FORECAST FOR TODAY THROUGH MONDAY. 850HPA TEMPERATURES BETWEEN TODAY AND MONDAY WILL WARM FROM APPX +5C TO +11C. THIS TRANSLATES INTO A 10 TO 20 DEGREE WARMING OF HIGH TEMPERATURES OVER THE NEXT THREE DAYS. THE TEMPERATURE WILD CARD RIGHT NOW IS THE TUG OF WAR THAT WILL EXIST THROUGHOUT THE FORECAST AREA BETWEEN BOUNDARY LAYER EVAPOTRANSPIRED MOISTURE /WHICH WOULD WORK TO KEEP TEMPERATURES FROM SKY-ROCKETING/ AS THE REGION IS BEGINNING TO GREEN UP SOME...AND THE MARKEDLY DRY AIR THAT HAS BEEN LEFT OVER THE REGION IN THE WAKE OF YESTERDAY`S IMPRESSIVE SPRING STORM SYSTEM /WHICH WOULD WORK TO HELP WARM THE AIRMASS NOW IN PLACE QUITE EFFICIENTLY/. SNOW COVER WILL NOT PLAY ALL THAT MUCH OF A ROLE AS SATELLITE IMAGERY REVEALS ALL THE SNOW PACK IS WELL WEST OF THIS FORECAST AREA OVER WESTERN SOUTH DAKOTA. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY THE MODELS AND GFS ENSEMBLES SHOW GREAT AGREEMENT EARLY ON IN THE PERIOD WITH THE WEATHER FEATURES AFFECTING THE REGION FOR MONDAY NIGHT THROUGH WEDNESDAY NIGHT AND THEN DIVERGE TOWARDS THE END OF THE PERIOD. FIRST OFF...A SHORT WAVE TROUGH AND ITS ASSOCIATED SURFACE LOW PRESSURE AREA AND TRAILING COLD FRONT WILL DROP ACROSS THE REGION MONDAY NIGHT AND EARLY TUESDAY. MODELS DONT INDICATE MUCH MOISTURE AVAILABLE WITH THIS SYSTEM WITH DEWPOINTS MAINLY IN THE MID 40S ALONG WITH LITTLE CAPE ALONG WITH DRY AIR IN THE LOW AND INTO THE MID LEVELS. WHEN THIS SURFACE LOW AND COLD FRONT MOVES THROUGH...IT SHOULD BE AT A MORE UNFAVORABLE TIME FOR CONVECTION TO DEVELOP AT NIGHT IN THE EARLY MORNING. THUS...JUST HAVE IN A 20 POP FOR LIGHT SHOWERS ON TUESDAY. OTHERWISE...THE MODELS THEN SHOW ANOTHER MUCH MORE SIGNIFICANT UPPER LOW/TROUGH AND SURFACE LOW PRESSURE AREA MOVING ACROSS THE CENTRAL PLAINS ON WEDNESDAY AND THURSDAY. THEY INDICATE NO PRECIPITATION FOR OUR AREA WITH THIS SYSTEM AS IT TREKS ACROSS TO THE SOUTH. THUS...REMOVED POPS FOR WEDNESDAY AND WEDNESDAY NIGHT FOR OUR CWA. AFTER THIS...THE GFS AND EC DIVERGE WITH THE NEXT TROUGH MOVING IN FROM THE WEST. THE GFS WAS MUCH STRONGER WITH A TROUGH MOVING INTO AND AFFECTING THE REGION BY FRIDAY WHILE THE EC WAS FARTHER NORTH...FASTER AND WEAKER WITH THIS TROUGH. LEFT THE FORECAST AS IS AT THIS POINT TO SEE WHAT LATER MODELS RUNS HAVE TO BRING TO MAYBE TAKE POPS OUT OF THE FORECAST. && .AVIATION... VFR SKIES ARE EXPECTED THROUGH 12Z SUNDAY WITH UNRESTRICTED VISIBILITIES AND NO SIGNIFICANT WEATHER EXPECTED. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...DORN LONG TERM...MOHR AVIATION...MOHR WEATHER.GOV/ABERDEEN sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1040 AM CDT FRI MAY 2 2008 .DISCUSSION... HAVE REFINED GRIDDED FCSTS FOR CURRNT INCRS AND ADVNCE OF RAIN FROM THE S/SE AND MADE MINOR ADJUSTMNTS TO TEMPS. OTRW CURNT WET FCST LOOKS GOOD WITH WDSPRD PCPN AFFECTING ALL OF FGCST AREA THIS AFTN INTO ERY EVE. NEW NAM IS A LTL FASTER ON PCPN EXIT LATR TNGT THAN WE HAVCE BEEN CARRYING BUT WILL LEAVE ALONE FOR NOW AND EVALUATE THE CONTG INFLOWING GUIDNCE. ZONE FCSTS ACTUALLY LOOK PRETTY GOOD BUT WILL UPDATE FOR ELIMINATION AND ADJUSTMNT OF MRNG WORDING AS WELL AS ABV MENTND MINOR CHANGES. && .PREV DISCUSSION... CLOSED UPPER LOW STILL POSITIONED TO THE SOUTHWEST OF OUR FA OVER CENTRAL NEBRASKA PER WATER VAPOR AND REGIONAL RADAR LOOPS. MODELS HANDLE UPPER LOW SIMILARLY THROUGH THE NEXT 24 HOURS...MOVING SLOWLY EAST INTO WESTERN IOWA BY EARLY EVENING...THEN LIFTING NORTHEAST AND OPENING INTO ELONGATED TROUGH OVER WI BY DAYBREAK SATURDAY. MAIN CHALLENGE FOR TODAY WILL BE PRECIP EVOLUTION AS THE LOW MOVES TO OUR SOUTH. MODELS CONTINUE TO SHOW TROWAL AXIS WELL TO THE NORTH OF OUR FA...COLLAPSING SLIGHTLY SOUTHWARD BY MIDDAY...THEN MORE STRONGLY PIVOTING SOUTHEAST INTO SERN SD BY EVENING AS THE LOW MOVES EAST. THINK THIS...COMBINED WITH LIMITED RESIDUAL MOISTURE EAST OF THE UPPER LOW AS VERY STRONG BOW ECHO MOVES THROUGH NORTHERN MISSOURI EARLY THIS MORNING...WILL LEAVE OUR FA LARGELY FREE OF WIDEPSREAD RAIN THROUGH THE MORNING HOURS. EXCEPTION WILL BE FAR EASTERN AREAS WHERE BATCH OF SHOWERS CURRENTLY SOUTH OF KSUX WILL LIFT NORTHEAST THROUGH THE MORNING. NAM AND RUC...AND TO SOME EXTENT GFS...SHOW MID LEVEL MOISTURE INCREASE OVER MOST OF THE FA BY LATE MORNING...WITH BAND OF HEAVIER QPF INDICATED ON NAM AND RUC DEVELOPING THROUGH THE MISSOURI VALLEY BY LATE MORNING AS ANOTHER WAVE ROTATES INTO THE AREA AROUND THE UPPER LOW. CONCERN I HAVE WITH THIS SOLUTION IS WHAT EFFECT THE MISSOURI BOW ECHO WILL HAVE ON AVAILABLE MOISTURE FOR THIS WAVE TO WORK WITH. THUS HAVE STARTED MOST OF THE WESTERN AND CENTRAL FA OUT WITH ONLY SLIGHT CHANCE POPS AND EVEN DRIZZLE FROM LOW STRATUS DECK EARLY THIS MORNING...BRINGING POPS UP INTO THE MID-SCATTERED RANGE TO ACKNOWLEDGE THE WAVE SWINGING NORTH. BULK OF OUR PRECIP CHANCES WILL LIKELY WAIT UNTIL TROWAL PIVOTS SOUTHEAST INTO OUR FA DURING THE LATE AFTERNOON/EVENING. HAVE STUCK WITH HIGH CATEGORICAL POPS ALONG/NORTHWEST OF THE TROWAL AXIS... SLOWLY DECREASING MAX POPS AFTER 06Z AS THE SYSTEM SHIFTS EAST AND TROWAL WEAKENS THROUGH THE OVERNIGHT HOURS. STILL POTENTIAL FOR A HEAVIER BAND OF RAIN DURING THE LATE AFTERNOON/EVENING FROM LAKE ANDES/MITCHELL NORTHEAST TOWARD MARSHALL MN IF TROWAL CAN MAINTAIN ITS STRENGTH AND INTENSE LIFT AS IT MOVES SOUTHEAST. HOWEVER...EVEN IF TROWAL EFFECTS WEAKEN MORE QUICKLY THAN EXPECTED...OR IF MISSOURI BOW ECHO FROM THIS MORNING DISRUPTS MOISTURE STREAM INTO THE TROWAL TOO MUCH...WOULD STILL EXPECT A DECENT CHANCE FOR LIGHT RAIN TO ROTATE INTO THE AREA FROM THE NORTHWEST...SO HIGH POPS WARRANTED EVEN IF QPF ENDS UP MUCH LOWER. FORECAST SOUNDINGS SHOW COOLS ENOUGH TO MAINTAIN SNOW ABOVE 900MB...SO QUESTION FOR THE OVERNIGHT IS WHETHER ABOVE FREEZING NEAR SURFACE LAYER WILL BE DEEP ENOUGH TO MELT THE ICE CRYSTALS OR SHALLOW ENOUGH TO MAINTAIN SNOW TO THE GROUND. HAVE PREDOMINENTLY KEPT RAIN OR SNOW WORDING MOST AREAS... AS IT APPEARS COLDEST NEAR SURFACE AIR WILL HOLD OFF UNTIL PRECIP STARTS TO WIND DOWN. THINK ACCUMULATION WILL THEREFORE BE LARGELY ELEVATION DEPENDENT...AND HAVE TRIED TO PROTRAY THIS IN GRIDS WITH AMOUNTS GREATER THAN AN INCH CONFINED TO HIGHER AREAS OF GREGORY COUNTY...AND ALSO FROM THE BUFFALO RIDGE WESTWARD INTO HIGHER AREAS OF EAST CENTRAL SD. STRONG PUSH OF DRY AIR PLOWS INTO THE WESTERN FA BEFORE DAYBREAK SATURDAY...THEN CONTINUES QUICKLY EAST THROUGH THE MORNING...WITH ABUNDANT SUNSHINE LIKELY BY LATE MORNING IN MOST AREAS. WILL LINGER A SLIGHT CHANCE OF RAIN OR SNOW IN FAR EASTERN AREAS EARLY IN THE MORNING...BUT MORE LIKELY ANY PRECIP WILL HAVE EXITED OUR EASTERN COUNTIES BEFORE 03/12Z. SUNSHINE SHOULD HELP TEMPERATURES REBOUND INTO THE 50S SATURDAY...WITH GRADUAL WARMUP TO NEAR NORMAL EARLY MAY TEMPS FOR SUNDAY THROUGH THE FIRST HALF OF THE WEEK. DRY WEATHER SHOULD PREVAIL THROUGH TUESDAY. LITTLE AGREEMENT SEEN IN UPPER LEVEL PATTERN SOLUTIONS ON GFS/ECMWF FOR MIDDLE OF NEXT WEEK...SO HAVE MADE NO CHANGES TO GOING PRECIP CHANCES FOR TUESDAY NIGHT/WEDNESDAY AT THIS TIME. && .AVIATION... MAIN STORY EARLY THIS MORNING WILL BE THE IFR CIGS AND MVFR VSBYS DUE TO FOG. THE ONLY THING PREVENTING THE FOG FROM BECOMING DENSE OR MORE WIDESPREAD WILL BE THE WINDS AROUND THE AREA. EXPECT THE WINDS TO BE STRONG ENOUGH TO PREVENT ANYTHING LOWER THEN MVFR VSBYS. PRECIP CHANCES WILL BE MINIMAL THIS MORNING EXCEPT KSUX AND POSSIBLY KFSD MAY GET BRUSHED BY CURRENT SOUTHERN ACTIVITY MOVING NORTH/NORTHEAST. BEST CHANCE OF RAIN WILL BE WITH WRAP AROUND AND HAVE WORDED TAF ACCORDINGLY. PRECIP WILL BE OFF TO EAST BY 12Z SAT AS THE LOW MOVES EWD. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ WILLIAMS sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 500 AM CDT FRI MAY 2 2008 .DISCUSSION... CLOSED UPPER LOW STILL POSITIONED TO THE SOUTHWEST OF OUR FA OVER CENTRAL NEBRASKA PER WATER VAPOR AND REGIONAL RADAR LOOPS. MODELS HANDLE UPPER LOW SIMILARLY THROUGH THE NEXT 24 HOURS...MOVING SLOWLY EAST INTO WESTERN IOWA BY EARLY EVENING...THEN LIFTING NORTHEAST AND OPENING INTO ELONGATED TROUGH OVER WI BY DAYBREAK SATURDAY. MAIN CHALLENGE FOR TODAY WILL BE PRECIP EVOLUTION AS THE LOW MOVES TO OUR SOUTH. MODELS CONTINUE TO SHOW TROWAL AXIS WELL TO THE NORTH OF OUR FA...COLLAPSING SLIGHTLY SOUTHWARD BY MIDDAY...THEN MORE STRONGLY PIVOTING SOUTHEAST INTO SERN SD BY EVENING AS THE LOW MOVES EAST. THINK THIS...COMBINED WITH LIMITED RESIDUAL MOISTURE EAST OF THE UPPER LOW AS VERY STRONG BOW ECHO MOVES THROUGH NORTHERN MISSOURI EARLY THIS MORNING...WILL LEAVE OUR FA LARGELY FREE OF WIDEPSREAD RAIN THROUGH THE MORNING HOURS. EXCEPTION WILL BE FAR EASTERN AREAS WHERE BATCH OF SHOWERS CURRENTLY SOUTH OF KSUX WILL LIFT NORTHEAST THROUGH THE MORNING. NAM AND RUC...AND TO SOME EXTENT GFS...SHOW MID LEVEL MOISTURE INCREASE OVER MOST OF THE FA BY LATE MORNING...WITH BAND OF HEAVIER QPF INDICATED ON NAM AND RUC DEVELOPING THROUGH THE MISSOURI VALLEY BY LATE MORNING AS ANOTHER WAVE ROTATES INTO THE AREA AROUND THE UPPER LOW. CONCERN I HAVE WITH THIS SOLUTION IS WHAT EFFECT THE MISSOURI BOW ECHO WILL HAVE ON AVAILABLE MOISTURE FOR THIS WAVE TO WORK WITH. THUS HAVE STARTED MOST OF THE WESTERN AND CENTRAL FA OUT WITH ONLY SLIGHT CHANCE POPS AND EVEN DRIZZLE FROM LOW STRATUS DECK EARLY THIS MORNING...BRINGING POPS UP INTO THE MID-SCATTERED RANGE TO ACKNOWLEDGE THE WAVE SWINGING NORTH. BULK OF OUR PRECIP CHANCES WILL LIKELY WAIT UNTIL TROWAL PIVOTS SOUTHEAST INTO OUR FA DURING THE LATE AFTERNOON/EVENING. HAVE STUCK WITH HIGH CATEGORICAL POPS ALONG/NORTHWEST OF THE TROWAL AXIS... SLOWLY DECREASING MAX POPS AFTER 06Z AS THE SYSTEM SHIFTS EAST AND TROWAL WEAKENS THROUGH THE OVERNIGHT HOURS. STILL POTENTIAL FOR A HEAVIER BAND OF RAIN DURING THE LATE AFTERNOON/EVENING FROM LAKE ANDES/MITCHELL NORTHEAST TOWARD MARSHALL MN IF TROWAL CAN MAINTAIN ITS STRENGTH AND INTENSE LIFT AS IT MOVES SOUTHEAST. HOWEVER...EVEN IF TROWAL EFFECTS WEAKEN MORE QUICKLY THAN EXPECTED...OR IF MISSOURI BOW ECHO FROM THIS MORNING DISRUPTS MOISTURE STREAM INTO THE TROWAL TOO MUCH...WOULD STILL EXPECT A DECENT CHANCE FOR LIGHT RAIN TO ROTATE INTO THE AREA FROM THE NORTHWEST...SO HIGH POPS WARRANTED EVEN IF QPF ENDS UP MUCH LOWER. FORECAST SOUNDINGS SHOW COOLS ENOUGH TO MAINTAIN SNOW ABOVE 900MB...SO QUESTION FOR THE OVERNIGHT IS WHETHER ABOVE FREEZING NEAR SURFACE LAYER WILL BE DEEP ENOUGH TO MELT THE ICE CRYSTALS OR SHALLOW ENOUGH TO MAINTAIN SNOW TO THE GROUND. HAVE PREDOMINENTLY KEPT RAIN OR SNOW WORDING MOST AREAS... AS IT APPEARS COLDEST NEAR SURFACE AIR WILL HOLD OFF UNTIL PRECIP STARTS TO WIND DOWN. THINK ACCUMULATION WILL THEREFORE BE LARGELY ELEVATION DEPENDENT...AND HAVE TRIED TO PROTRAY THIS IN GRIDS WITH AMOUNTS GREATER THAN AN INCH CONFINED TO HIGHER AREAS OF GREGORY COUNTY...AND ALSO FROM THE BUFFALO RIDGE WESTWARD INTO HIGHER AREAS OF EAST CENTRAL SD. STRONG PUSH OF DRY AIR PLOWS INTO THE WESTERN FA BEFORE DAYBREAK SATURDAY...THEN CONTINUES QUICKLY EAST THROUGH THE MORNING...WITH ABUNDANT SUNSHINE LIKELY BY LATE MORNING IN MOST AREAS. WILL LINGER A SLIGHT CHANCE OF RAIN OR SNOW IN FAR EASTERN AREAS EARLY IN THE MORNING...BUT MORE LIKELY ANY PRECIP WILL HAVE EXITED OUR EASTERN COUNTIES BEFORE 03/12Z. SUNSHINE SHOULD HELP TEMPERATURES REBOUND INTO THE 50S SATURDAY...WITH GRADUAL WARMUP TO NEAR NORMAL EARLY MAY TEMPS FOR SUNDAY THROUGH THE FIRST HALF OF THE WEEK. DRY WEATHER SHOULD PREVAIL THROUGH TUESDAY. LITTLE AGREEMENT SEEN IN UPPER LEVEL PATTERN SOLUTIONS ON GFS/ECMWF FOR MIDDLE OF NEXT WEEK...SO HAVE MADE NO CHANGES TO GOING PRECIP CHANCES FOR TUESDAY NIGHT/WEDNESDAY AT THIS TIME. && .AVIATION... MAIN STORY EARLY THIS MORNING WILL BE THE IFR CIGS AND MVFR VSBYS DUE TO FOG. THE ONLY THING PREVENTING THE FOG FROM BECOMING DENSE OR MORE WIDESPREAD WILL BE THE WINDS AROUND THE AREA. EXPECT THE WINDS TO BE STRONG ENOUGH TO PREVENT ANYTHING LOWER THEN MVFR VSBYS. PRECIP CHANCES WILL BE MINIMAL THIS MORNING EXCEPT KSUX AND POSSIBLY KFSD MAY GET BRUSHED BY CURRENT SOUTHERN ACTIVITY MOVING NORTH/NORTHEAST. BEST CHANCE OF RAIN WILL BE WITH WRAP AROUND AND HAVE WORDED TAF ACCORDINGLY. PRECIP WILL BE OFF TO EAST BY 12Z SAT AS THE LOW MOVES EWD. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ JH/HEITKAMP sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 338 PM CDT FRI MAY 2 2008 .SHORT TERM... A STRONG UPPER LOW OVER THE NEBRASKA/IOWA BORDER CONTINUES TO MOVE OFF TO THE EAST. WATER VAPOR AND UPPER LEVEL EPV SHOWS ONE LAST PIECE OF JET ENERGY TRANSLATING AROUND THE BASE OF THE TROUGH THIS EVENING. AS THE TROUGH MOVES OFF A STRONG COLD FRONT WILL PASS THROUGH THE AREA OVERNIGHT TONIGHT. MODELS CONTINUE TO SHOW GOOD AGREEMENT ON THE TIMING OF THE FRONT WITH THE LATEST RUC MODEL RUNS SHOWING A SLIGHTLY FASTER FRONT. HAVE GONE WITH A SLIGHTLY FASTER SOLUTION DUE TO THE PROGGED HIGH PRESSURE RISES BEHIND THE FRONT. THE FRONT SHOULD ALSO BRING IN SOME SHALLOW LOW LEVEL MOISTURE. HOWEVER...MOISTURE LEVELS WILL LIKELY NOT BE SUFFICIENT FOR A STRATUS DECK. UPPER LEVEL FLOW WILL BECOME MORE ZONAL IN THE WAKE OF THE UPPER LEVEL TROUGH. LOW TEMPERATURES TONIGHT WILL BE COOL DESPITE GUSTY WINDS BEHIND THE COLD FRONTAL PASSAGE. FOR THIS REASON...UNCERTAINTY REMAINS HOW LOW THE TEMPERATURES WILL BE ACROSS THE SOUTHWESTERN PANHANDLE. MODELS INDICATE PRESSURE RISES THROUGH THE NIGHTTIME HOURS AND THROUGH SUNRISE TOMORROW. THEREFORE...WINDS MAY NOT COMPLETELY DECOUPLE BY DAYBREAK TOMORROW. DESPITE THIS...IT WILL STILL BE POSSIBLE THAT TEMPERATURES COULD BRIEFLY DROP BELOW FREEZING IN THE AFOREMENTIONED AREAS. JDV .LONG TERM... SOUTHEAST LOW LEVEL FLOW WILL GRADUALLY MODIFY THE COOL AIRMASS SATURDAY NIGHT AND EARLY SUNDAY. SINCE FRONT IS EXPECTED DEEP INTO SOUTH TEXAS...MOISTURE RETURN INITIALLY WILL BE LOW AND MAY BE INSUFFICIENT FOR MUCH OF A CHANCE OF THUNDER AS EARLY AS LATE SUNDAY GIVEN WEAK DYNAMIC SUPPORT AT THAT TIME. HAVE TRIMMED MENTION OF THUNDER SATURDAY EVENING A BIT FURTHER WEST INTO SOUTHWESTERN ZONES. MOISTURE SHOULD SURGE NORTHWARD MORE FREELY SUNDAY NIGHT AND MONDAY AS DEEPER SOUTHERLY FLOW DEVELOPS. UPPER RIDGE AXIS SHARPENING AND EDGING JUST INTO EASTERN ZONES SHOULD CREATE A FAVORABLE ENVIRONMENT FOR CHANCE OF THUNDER MORE AREAS. DIFFICULT TO ANTICIPATE DRY LINE MOVEMENT AND HAVE RETAINED BLANKET CHANCE COVERAGE INTO MONDAY NIGHT. PATTERN AT LEAST SUGGESTS SOME POTENTIAL FOR SEVERE STORMS AND WILL CONTINUE MENTION IN THE HAZARDOUS WEATHER OUTLOOK. DIVERGENCE OF MODEL SOLUTIONS FACTORS IN BY TUESDAY AS ECMWF REMAINS MORE PROGRESSIVE WITH LOW APPROACHING THROUGH THE SOUTHWEST WHILE GFS CAMP IS STILL CUTOFF BACK TO THE WEST. THE GFS AT LEAST HAS TRENDED A BIT MORE TO THE WEST SUGGESTING FURTHER CORRECTION TOWARDS PROGRESSIVE SOLUTION MAY OCCUR IN LATER RUNS. WE HAVE THUS RETAINED THE EARLIER LOW PRECIPITATION COVERAGE INDICATED BY THE OVERNIGHT SHIFT IN THIS REGARDS FOR TUESDAY. UNCLEAR STILL WHEN LOW WILL FINALLY PASS...QUICKER ECMWF WOULD SUGGEST A DRY WEDNESDAY WHILE SLOWER GFS STILL PAINTS THUNDER CHANCES WEDNESDAY. A COMPROMISE SOLUTION IS FAVORED WEDNESDAY...ONCE AGAIN RETAINING LOW THUNDER CHANCES. DRIER FLOW TO FOLLOW...BUT UPPER FLOW MAY BACK QUICKLY AGAIN BY LATE WEEK AS AN ACTIVE PATTERN MOVES WAVES OFF THE PACIFIC COAST INTO THE SOUTHWEST. TIMING OF WAVES THAT FAR OUT DIFFICULT TO ANTICIPATE AND THUNDER CHANCES NOT MENTIONED AT THIS TIME. MCQUEEN && .PRELIMINARY POINT TEMPS/POPS... FRIONA 32 67 40 79 54 / 0 0 0 0 20 TULIA 34 66 40 75 54 / 0 0 0 0 20 PLAINVIEW 34 67 42 75 56 / 0 0 0 0 20 LEVELLAND 36 70 46 78 58 / 0 0 0 0 20 LUBBOCK 38 70 48 77 60 / 0 0 0 0 20 DENVER CITY 33 71 47 80 60 / 0 0 0 0 20 BROWNFIELD 39 70 46 78 61 / 0 0 0 0 20 CHILDRESS 42 71 44 78 62 / 0 0 0 0 10 SPUR 40 70 47 77 62 / 0 0 0 0 20 ASPERMONT 43 72 47 79 63 / 0 0 0 0 20 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01/05 tx AREA FORECAST DISCUSSION...UPDATED AVIATION DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 505 AM PDT SAT MAY 3 2008 .SYNOPSIS... A WEAKENING WEATHER SYSTEM WILL CROSS THE INLAND NORTHWEST TODAY AND TONIGHT...BUT WILL GENERALLY PRODUCE LITTLE MORE THAN CONSIDERABLE CLOUDINESS. CLEARING SKIES AND WARMING TEMPERATURES WILL ACCENTUATE THE LATTER HALF OF THE WEEKEND. FAIR WEATHER WILL CONTINUE THROUGH EARLY NEXT WEEK BEFORE MUCH COOLER WEATHER ARRIVES BY MID-WEEK. && .DISCUSSION... TODAY AND TONIGHT...SATELLITE PICTURES THIS MORNING STILL DEPICTING SLOW MOVING AND RATHER ELONGATED UPPER LEVEL TROF EXTENDING FROM NORTHERN BC SOUTH TO NORCAL. NOT MUCH ACTIVITY OR PRECIPITATION GOING ON WITHIN THE VICINITY OF THIS TROF...OTHER THAN A SMALL BATCH OF ELEVATED PRECIP IN THE SOUTH WA CASCADES. THERE WAS ALSO A SMALL AREA OF LIGHT RAIN ASSOCIATED WITH WEAK SURFACE FRONT EXTENDING FROM SOUTHERN VANCOUVER ISLAND TO AROUND 44/128. THE LATTER FEATURE WILL GENERALLY BE A NON-PLAYER FOR OUR AREA TODAY...AS THE UPPER LEVEL TROF IS EXPECTED TO SHEAR APART EVEN FURTHER WITH STRONG UPPER LEVEL RIDGING EXPECTED TO ENSUE BETWEEN 130-140W. THIS WILL SLOW THE EASTWARD PUSH OF THE FRONT TO A VIRTUAL CRAWL...NOT TO MENTION...IT IS LIKELY TO SHALLOW TO MAKE IT OVER THE CASCADES ANYWAY. OF MORE CONCERN IS THE BATCH OF PRECIP OVER THE SOUTHERN WA CASCADES. NONE OF THE SHORT RANGE MODELS ARE HANDLING THIS VERY WELL...HOWEVER IT DOES LOOSELY CORRELATE WITH AN AREA OF MODERATE UPPER LEVEL DIFLUENCE AHEAD OF A ELONGATING VORT MAX CENTERED NEAR MT ST. HELENS. WATER VAPOR LOOPS SUGGEST THIS FEATURE IS TRACKING TO A ENE SIMILAR TO WHAT THE 06Z NAM WAS FORECASTING...BUT HANDLED EVEN BETTER BY THE RUC. THE GFS SEEMED TO BE UNDERDONE AS OF 06Z WITH THE FEATURE AS DID THE ECMWF. GIVEN THE TRACK OF THE VORT LOBE AND ASSOCIATED UPPER LEVEL DIFLUENCE...WE WILL KEEP POPS FOR THIS MORNING LOCKED NEAR THE CASCADES. THIS IS NOT DUE TO OROGRAPHICS HOWEVER AS THE MEAN FLOW BELOW 700 MBS IS EXCEEDINGLY LIGHT AND RATHER VARIABLE. QPF VALUES SHOULD BE RATHER LIGHT AS FORCING AND POTENTIAL INSTABILITY ARE VERY WEAK. ALSO SURFACE DEWPOINT DEPRESSIONS ALONG THE CASCADES ARE RATHER HIGH. IF THE NAM IS CORRECT THIS FEATURE WILL GENERALLY WEAKEN OR DISSOLVE AS THE MAIN UPPER LEVEL TROF...CURRENTLY OFF THE COAST APPROACHES THE CASCADE CREST AROUND 00Z. NOT TERRIBLY EXCITED OR CONFIDENT MEASURABLE PRECIP WILL DEVELOP ANYWHERE ACROSS THE CWA TODAY...AS TIME HEIGHT SECTIONS GENERALLY SHOW ALL MOISTURE AHEAD OF THE TROF WILL BE RESTRICTED ABOVE 700 MBS. SUSPECT THAT IF PRECIP DOES FALL...MUCH OF IT WILL BE IN THE FORM OF SPRINKLES. FOR TONIGHT THE MODELS CONTINUE TO HAVE TROUBLES IN REGARD TO THE INCOMING TROF AXIS. THE NAM TAKES THE TROF ACROSS OUR CWA AS A WEAK OPEN WAVE AND THEN DIGS IT SOUTH INTO EASTERN OREGON OVERNIGHT. MEANWHILE THE GFS AND ECMWF CLOSE OFF THE TROF AND DROP A SIGNIFICANT CLOSED LOW DUE SOUTH THROUGH WESTERN OREGON WHILE BUILDING THE AFOREMENTIONED UPPER LEVEL RIDGE INTO THE NW CORNER OF OUR CWA. THE SREF ALSO EXHIBITS VAST DIFFERENCES WITH VERY LARGE HEIGHT SPREADS FOR SUCH A CLOSE TIME PERIOD...BUT EVEN ITS MEAN TENDS TO FAVOR THE GFS/ECMWF SOLUTION. THIS SUGGESTS EVEN TONIGHT SHOULD BE A RELATIVELY DRY PERIOD OVER MUCH OF THE CWA AS MOST OF THE MEASURABLE PRECIP WILL REMAIN SOUTH OF OUR CWA. BEST CHANCES IN THE OVERNIGHT PERIOD WILL LIKELY OCCUR ACROSS THE SE CORNER OF THE CWA IN A REGION OF WEAK TO MODERATE ISENTROPIC ASCENT AND GOOD MOISTURE AVAILABILITY ON THE 290K SURFACE. EVEN SO...CROSS SECTIONAL ANALYSIS SHOWS OVER WEAK SYNOPTIC SCALE LIFT...SO POPS WILL ONLY BE IN THE LOW CHANCE CATEGORY. FX SUNDAY THROUGH MONDAY NIGHT...MODELS ARE IN GOOD AGREEMENT WITH DROPPING A WEAK LOW SOUTH TO CALIFORNIA AND BRINGING A FLAT RIDGE OVER THE REGION ON SUNDAY. AS THE UPPER LEVEL LOW SINKS SOUTH THE FORECAST AREA TRANSITIONS TO NORTH THEN WESTERLY FLOW ALOFT. A MUCH DRIER AIRMASS MOVES OVERHEAD AND 850MB TEMPERATURES WARM TO +11C. GOOD MIXING POTENTIAL WILL RESULT IN MAX TEMPERATURES IN THE UPPER 60S TO MID 70S ACROSS THE REGION ON SUNDAY. WESTERLY FLOW CONTINUES ON MONDAY WITH A WEAK SHORTWAVE CLIPPING OUR NORTHERN ZONES. WITH THE BEST FORCING REMAINING TO OUR NORTH...SHOWERS WILL BE CONFINED TO THE IDAHO PANHANDLE MOUNTAINS AND MAINLY IN THE AFTERNOON. INCREASED CLOUD COVER ACROSS THE NORTH WILL KEEP TEMPERATURES SLIGHTLY COOLER THERE ON MONDAY WHILE THE REMAINDER OF THE FORECAST AREA WILL SEE HIGHS CLOSE TO SUNDAYS READINGS. HEIGHTS WILL RISE A BIT MONDAY NIGHT AS THE NEXT WEAK SHORTWAVE APPROACHES THE COAST. TUESDAY THROUGH FRIDAY...A WEAK WAVE ROLLS THROUGH THE INLAND NORTHWEST TUESDAY BRINGING SOME CLOUDS BUT LITTLE IN THE WAY OF PRECIPITATION. MODEL AGREEMENT CONTINUES TO BE FAIRLY GOOD THAT A STRONGER LOW PRESSURE SYSTEM WILL AFFECT THE AREA STARTING TUESDAY NIGHT AS A CLOSED LOW DROPS DOWN FROM BRITISH COLUMBIA AND HANGS OUT OVER THE REGION THROUGH FRIDAY. THERE ARE SOME DIFFERENCES IN THE DETAILS OF THE CLOSED LOW SO ONLY MINOR CHANGES MADE TO THE EXTENDED PORTION OF THE FORECAST. EXPECT BREEZY CONDITIONS ON WEDNESDAY AS THE SURFACE PRESSURE GRADIENT TIGHTENS AND COLD AIR ADVECTION PUSHES IN FROM THE WEST. INCREASED CLOUD COVER AND PRECIPITATION WILL SEND TEMPERATURES ON A COOLING TREND WITH HIGHS DIPPING SEVERAL DEGREES BELOW SEASONAL NORMALS THROUGH THE END OF THE WORK WEEK. /KELCH && .AVIATION... VFR OVERCAST SKIES WILL LIKELY CONTINUE AT ALL TAF SITES THROUGH 12Z SUN AHEAD OF ELONGATING AND FAIRLY WEAK UPPER LEVEL TROF. THIS TROF WILL LIKELY PRODUCE PRECIP WITH THE BEST CHANCES OCCURRING NEAR THE CASCADES TODAY AND ACROSS THE BLUES AND CLEARWATERS OVERNIGHT. CIGS COULD BRIEFLY LOWER TO MVFR AT KPUW OVERNIGHT...SPCLY AFT 05Z...IN RESPONSE TO THE PRECIP...BUT CHANCE WAS TOO SMALL TO INCLUDE IN TAF. FX && .PRELIMINARY POINT TEMPS/POPS... SPOKANE 61 40 68 44 69 43 / 10 10 10 10 10 0 COEUR D`ALENE 61 38 68 41 68 41 / 10 10 10 10 20 10 PULLMAN 61 40 66 45 69 45 / 10 20 10 10 10 0 LEWISTON 68 44 72 48 74 48 / 10 10 10 0 0 0 COLVILLE 65 38 71 40 70 40 / 10 10 10 10 10 10 SANDPOINT 61 36 66 37 66 37 / 0 0 10 10 20 10 KELLOGG 60 39 66 40 65 39 / 10 20 10 20 20 10 MOSES LAKE 67 42 75 44 76 43 / 10 10 0 0 0 0 WENATCHEE 66 47 73 49 73 49 / 10 10 0 0 0 0 OMAK 66 40 72 42 74 40 / 10 10 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...NONE. WA...NONE. && $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 937 PM CDT FRI MAY 2 2008 .UPDATED... MADE SEVERAL TWEAKS TO THE FORECAST FROM THIS EVENING INTO SATURDAY MORNING. STACKED LOW CURRENTLY LOCATED NEAR KMCW/KAEL/KAUM AREA AT 02Z. SATELLITE IMAGERY SHOWS SHORT WAVE ROTATING NORTH AND THEN NORTHWEST AROUND THE MAIN LOW THIS EVENING...IN FUJIWHARA FASHION. THIS HAS CAUSED THE MAIN CIRCULATION TO SLOW AND RETROGRADE A BIT THE LAST FEW HOURS. BUT ONCE THIS SECONDARY WAVE GETS ON THE WEST AND SOUTHWEST SIDE...THE ENTIRE THING SHOULD TRANSLATE EAST. DRY SLOT HAS SURGED ALL THE WAY TO NORTHEAST WI...WHILE DEFORMATION AXIS IS SET UP FROM WESTERN IA UP THROUGH NORTHEAST MN. EXPECTING THE DEFORMATION PRECIPITATION SHIELD TO SHIFT INTO THE FORECAST AREA OVERNIGHT...AND MOVE EAST OF THE AREA BY SATURDAY AFTERNOON. PREVIOUS MODEL SOLUTIONS AND EVEN THE NEW 00Z NAM STILL SUGGESTING WE COULD SEE COLD ENOUGH AIR FOR SNOW ON THE BACK EDGE. HOWEVER... THERE REMAINS A NARROW WEDGE OF WARMER AIR NEAR THE SURFACE TO LIMIT EXTENT OF SNOW. ALSO...MODELS MAY BE A BIT COOL GIVEN CURRENT TEMPERATURE/DEWPOINT PROFILE UNDER THE DEFORMATION AREA. HAVE DECIDED TO GO WITH A SLIGHTLY WARMER SCENARIO THAN WHAT WE HAD GOING IN THE PREVIOUS FORECAST. THUS...LIMITING THE SNOW MENTION TO A FEW HOURS LATE TONIGHT INTO EARLY SATURDAY MORNING...AND ALSO LIMITING THE EXTENT OF THIS COVERAGE. UPDATED FORECAST WAS SENT AT 928 PM. MW && .PREV DISCUSSION... .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT SEVERE WEATHER POSSIBILITY LATE THIS AFTERNOON AND EARLY EVENING... AND SNOW POSSIBILITIES LATE TONIGHT AND SATURDAY MORNING ARE THE PRIMARY CONCERNS WITH THIS PART OF THE FORECAST. AT 3 PM...A STRONG LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTH CENTRAL MINNESOTA. A WARM/OCCLUDED FRONT EXTENDED FROM SHEBOYGAN WISCONSIN TO AUSTIN MINNESOTA. NORTH OF THIS FRONT...THE TEMPERATURES RANGED FROM THE MID 40S TO MID 50S. MEANWHILE TEMPERATURES WERE IN THE 60S AND 70S SOUTH OF THIS FRONT. RESIDUAL CLOUDS FROM THIS MORNINGS SHOWERS AND THUNDERSTORMS HAS LIMITED THE RECOVERY OF INSTABILITY IN THE WARM SECTOR OF THIS SYSTEM. AS OF 02.19Z...THERE WAS A NARROW BAND OF SURFACE BASED CAPES IN THE EXCESS OF 500 J/KG FROM DUBUQUE TO MASON CITY. THE EFFECTIVE SHEAR IS RUNNING AROUND 30 KNOTS. THERE WAS A FEW FUNNEL CLOUD REPORTS ACROSS NORTHEAST IOWA EARLIER IN THE AFTERNOON. IN ADDITION...A 52 KNOT WIND GUST WAS REPORT AT A SCHOOL NET IN MASON CITY AT 308 PM. THE 02.18Z RUC IS CONTINUING TO SHOW THAT A NARROW RIBBON OF MOST UNSTABLE CAPES BETWEEN 500 TO 800 J/KG WILL MOVE ACROSS NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND SOUTHWEST...WEST CENTRAL...AND CENTRAL WISCONSIN LATE THIS AFTERNOON AND EVENING. BOTH THE 0-3 KM AND 0-6 KM SHEAR ARE RUNNING AROUND 30 KNOTS. WITH QUITE A BIT OF CLOUD COVER...IT LOOKS LIKE WE WILL HAVE A VERY LIMITED TIME PERIOD FOR ANY SEVERE WEATHER. WE WILL HAVE TO WATCH THIS CLOSELY THIS EVENING...BUT AT THIS TIME IT LOOKS LIKE IT WILL NOT BE A WIDESPREAD EVENT. IT CONTINUES TO LOOK LIKE THE THREAT FOR ANY THUNDERSTORMS SHOULD BE OVER BY 8 PM THIS EVENING. BEHIND THIS SYSTEM...NORTHWEST WINDS WILL GUST INTO THE 20 TO 30 MPH RANGE...AND THERE WILL BE STRONG COLD AIR ADVECTION. WITH THE MODELS CONTINUING TO SHOW THAT THE 850 MB TEMPERATURES WILL FALL INTO THE -2C TO 0C RANGE LATE TONIGHT AND SATURDAY MORNING. AS THE DEFORMATION BAND MOVES EAST ACROSS THE AREA. THE RAIN WILL OCCASIONALLY CHANGE OVER SNOW AT TIMES. WITH TEMPERATURES ABOVE FREEZING...I AM NOT EXPECTING ANY ACCUMULATIONS. HOWEVER IF THE RATES ARE HIGH ENOUGH...YOU MAY SEE A BRIEF ACCUMULATION...BUT IT WILL THEN MELT QUICKLY. IT CONTINUES TO LOOK LIKE THE FRONTOGENETIC FORCING WILL QUICKLY WEAKEN ON SATURDAY AFTERNOON. AS A THIS OCCUR...THE DEFORMATION BAND OF PRECIPITATION WILL QUICKLY DISSIPATE. .LONG TERM...MONDAY THROUGH FRIDAY THE MEDIUM RANGE MODELS CONTINUE TO STRUGGLE WITH THE TIMING AND LOCATIONS OF A SERIES OF TROUGHS MOVING EASTWARD ACROSS THE UNITED STATES DURING THIS TIME PERIOD. THE RUN TO RUN CONSISTENCY HAS NOT BEEN THAT GREAT DURING THE PAST SEVERAL DAYS. AS A RESULT...THERE IS VERY LITTLE CONFIDENCE IN THIS PART OF THE FORECAST. ONE OF THE FEW THINGS THAT HAS BEEN CONSISTENTLY SHOWING UP IN THE MODELS IS A CHANCE OF SHOWERS ON MONDAY ACROSS NORTH CENTRAL AND CENTRAL WISCONSIN AS A COLD FRONT MOVES THROUGH THE REGION. SINCE THIS HAS BEEN A CONSISTENT SIGNAL...I HAVE ADDED A SMALL CHANCE OF PRECIPITATION FOR THIS TIME PERIOD. ONE THING THAT IS INTERESTING IS THAT THE 02.12Z GFS AND ECMWF ARE NOW IN AGREEMENT THAT A TROUGH WILL MOVE THROUGH THE REGION ON TUESDAY AND TUESDAY NIGHT. I CURRENTLY HAVE A 20 TO 30 PERCENT CHANCE OF SHOWERS DURING THIS TIME PERIOD. IF THIS TREND CONTINUES... WE WILL HAVE TO RAISE THESE PROBABILITIES A BIT HIGHER OVER THE WEEKEND. && .AVIATION...LATE THIS AFTERNOON THROUGH SATURDAY MORNING STRONG AREA OF LOW PRESSURE WILL MOVE FROM WESTERN IA INTO WEST CENTRAL WI BY EARLY THIS EVENING. THIS WILL SWING A COLD FRONT NORTHEAST INTO THE AREA THIS AFTERNOON WITH A BROKEN LINE OF SHRA/TS. A FEW OF THESE STORMS MAY BECOME SEVERE WITH DAMAGING WINDS AND HAIL. INCLUDED 2SM +TSRA WITH GUSTS TO 40 MPH AT THE KRST/KLSE TAF SITES IN THE 20-22Z TIME FRAME. THE COLD FRONT AND ANY LINGERING SHRA ACTIVITY WILL EXIT NORTHEAST OF THE AREA BY 03Z THIS EVENING. BEHIND THE COLD FRONT AND SHRA ACTIVITY...CONDITIONS ARE EXPECTED TO IMPROVE INTO VFR/MVFR CATEGORY. AS THE LOW MOVES INTO NORTHERN WI/UPPER MICHIGAN TOWARD MORNING...WINDS WILL SHIFT AND BECOME GUSTY FROM THE NORTHWEST. COLDER AIR FILTERING INTO THE AREA ON NORTHWEST WINDS WILL PRODUCE A MIXTURE OF -SHRASN AFTER 08Z...WITH CIGS LOWERING INTO MVFR RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ 01/01/01 wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 351 PM CDT FRI MAY 2 2008 .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT SEVERE WEATHER POSSIBILITY LATE THIS AFTERNOON AND EARLY EVENING... AND SNOW POSSIBILITIES LATE TONIGHT AND SATURDAY MORNING ARE THE PRIMARY CONCERNS WITH THIS PART OF THE FORECAST. AT 3 PM...A STRONG LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTH CENTRAL MINNESOTA. A WARM/OCCLUDED FRONT EXTENDED FROM SHEBOYGAN WISCONSIN TO AUSTIN MINNESOTA. NORTH OF THIS FRONT...THE TEMPERATURES RANGED FROM THE MID 40S TO MID 50S. MEANWHILE TEMPERATURES WERE IN THE 60S AND 70S SOUTH OF THIS FRONT. RESIDUAL CLOUDS FROM THIS MORNINGS SHOWERS AND THUNDERSTORMS HAS LIMITED THE RECOVERY OF INSTABILITY IN THE WARM SECTOR OF THIS SYSTEM. AS OF 02.19Z...THERE WAS A NARROW BAND OF SURFACE BASED CAPES IN THE EXCESS OF 500 J/KG FROM DUBUQUE TO MASON CITY. THE EFFECTIVE SHEAR IS RUNNING AROUND 30 KNOTS. THERE WAS A FEW FUNNEL CLOUD REPORTS ACROSS NORTHEAST IOWA EARLIER IN THE AFTERNOON. IN ADDITION...A 52 KNOT WIND GUST WAS REPORT AT A SCHOOL NET IN MASON CITY AT 308 PM. THE 02.18Z RUC IS CONTINUING TO SHOW THAT A NARROW RIBBON OF MOST UNSTABLE CAPES BETWEEN 500 TO 800 J/KG WILL MOVE ACROSS NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND SOUTHWEST...WEST CENTRAL...AND CENTRAL WISCONSIN LATE THIS AFTERNOON AND EVENING. BOTH THE 0-3 KM AND 0-6 KM SHEAR ARE RUNNING AROUND 30 KNOTS. WITH QUITE A BIT OF CLOUD COVER...IT LOOKS LIKE WE WILL HAVE A VERY LIMITED TIME PERIOD FOR ANY SEVERE WEATHER. WE WILL HAVE TO WATCH THIS CLOSELY THIS EVENING...BUT AT THIS TIME IT LOOKS LIKE IT WILL NOT BE A WIDESPREAD EVENT. IT CONTINUES TO LOOK LIKE THE THREAT FOR ANY THUNDERSTORMS SHOULD BE OVER BY 8 PM THIS EVENING. BEHIND THIS SYSTEM...NORTHWEST WINDS WILL GUST INTO THE 20 TO 30 MPH RANGE...AND THERE WILL BE STRONG COLD AIR ADVECTION. WITH THE MODELS CONTINUING TO SHOW THAT THE 850 MB TEMPERATURES WILL FALL INTO THE -2C TO 0C RANGE LATE TONIGHT AND SATURDAY MORNING. AS THE DEFORMATION BAND MOVES EAST ACROSS THE AREA. THE RAIN WILL OCCASIONALLY CHANGE OVER SNOW AT TIMES. WITH TEMPERATURES ABOVE FREEZING...I AM NOT EXPECTING ANY ACCUMULATIONS. HOWEVER IF THE RATES ARE HIGH ENOUGH...YOU MAY SEE A BRIEF ACCUMULATION...BUT IT WILL THEN MELT QUICKLY. IT CONTINUES TO LOOK LIKE THE FRONTOGENETIC FORCING WILL QUICKLY WEAKEN ON SATURDAY AFTERNOON. AS A THIS OCCUR...THE DEFORMATION BAND OF PRECIPITATION WILL QUICKLY DISSIPATE. .LONG TERM...MONDAY THROUGH FRIDAY THE MEDIUM RANGE MODELS CONTINUE TO STRUGGLE WITH THE TIMING AND LOCATIONS OF A SERIES OF TROUGHS MOVING EASTWARD ACROSS THE UNITED STATES DURING THIS TIME PERIOD. THE RUN TO RUN CONSISTENCY HAS NOT BEEN THAT GREAT DURING THE PAST SEVERAL DAYS. AS A RESULT...THERE IS VERY LITTLE CONFIDENCE IN THIS PART OF THE FORECAST. ONE OF THE FEW THINGS THAT HAS BEEN CONSISTENTLY SHOWING UP IN THE MODELS IS A CHANCE OF SHOWERS ON MONDAY ACROSS NORTH CENTRAL AND CENTRAL WISCONSIN AS A COLD FRONT MOVES THROUGH THE REGION. SINCE THIS HAS BEEN A CONSISTENT SIGNAL...I HAVE ADDED A SMALL CHANCE OF PRECIPITATION FOR THIS TIME PERIOD. ONE THING THAT IS INTERESTING IS THAT THE 02.12Z GFS AND ECMWF ARE NOW IN AGREEMENT THAT A TROUGH WILL MOVE THROUGH THE REGION ON TUESDAY AND TUESDAY NIGHT. I CURRENTLY HAVE A 20 TO 30 PERCENT CHANCE OF SHOWERS DURING THIS TIME PERIOD. IF THIS TREND CONTINUES... WE WILL HAVE TO RAISE THESE PROBABILITIES A BIT HIGHER OVER THE WEEKEND. && .AVIATION...LATE THIS AFTERNOON THROUGH SATURDAY MORNING STRONG AREA OF LOW PRESSURE WILL MOVE FROM WESTERN IA INTO WEST CENTRAL WI BY EARLY THIS EVENING. THIS WILL SWING A COLD FRONT NORTHEAST INTO THE AREA THIS AFTERNOON WITH A BROKEN LINE OF SHRA/TS. A FEW OF THESE STORMS MAY BECOME SEVERE WITH DAMAGING WINDS AND HAIL. INCLUDED 2SM +TSRA WITH GUSTS TO 40 MPH AT THE KRST/KLSE TAF SITES IN THE 20-22Z TIME FRAME. THE COLD FRONT AND ANY LINGERING SHRA ACTIVITY WILL EXIT NORTHEAST OF THE AREA BY 03Z THIS EVENING. BEHIND THE COLD FRONT AND SHRA ACTIVITY...CONDITIONS ARE EXPECTED TO IMPROVE INTO VFR/MVFR CATEGORY. AS THE LOW MOVES INTO NORTHERN WI/UPPER MICHIGAN TOWARD MORNING...WINDS WILL SHIFT AND BECOME GUSTY FROM THE NORTHWEST. COLDER AIR FILTERING INTO THE AREA ON NORTHWEST WINDS WILL PRODUCE A MIXTURE OF -SHRASN AFTER 08Z...WITH CIGS LOWERING INTO MVFR RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ 01/01/01 wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 212 PM CDT FRI MAY 2 2008 .SHORT TERM... THE WINDOW FOR SEVERE THREAT IS BEGINNING. THERE IS STILL A SMALL CHANCE OF SEVERE STORMS...ALONG WITH ISOLATED TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING. GOOD UPPER DIFLUENCE AS 95 KT UPPER JET PUSHES INTO THE LAKE MICHIGAN AREA THIS EVENING. VISIBLE SATELLITE IMAGERY SHOWING CLOUDS THINNING BEHIND EARLY AFTERNOON BAND OF THUNDERSTORMS ACROSS FAR SOUTHERN WI AND NORTHERN IL. LI`S HAVE RISEN TO -3. EXPECT MAIN THREAT JUST AHEAD OF DRY PUNCH THAT WILL MOVE INTO THE FORECAST AREA LATE THIS AFTERNOON AND EARLY THIS EVENING. WATER VAPOR LOOP SHOWS DRYING JUST NOW PUSHING INTO THE EXTREME SOUTHWEST. FORECAST SOUNDINGS OFF 12Z NAM AND 17Z RUC HAVE MARGINAL CAPE...BUT THIS MAY BE UNDERDONE WITH A LITTLE HEATING. ALSO A BRIEF TORNADO POTENTIAL WITH HELICITY RAISING TO AROUND 230. EHI VALUES ARE NEAR 1...BUT WITH A LITTLE MORE CAPE THOSE WOULD BE HIGHER. HOWEVER RUC IS SHOWING THAT DRY PUNCH PUSHES IN FAIRLY RAPIDLY. IF THIS HAPPENS LIMITED INSTABILITY MAY NOT BE ENOUGH FOR DEEP CONVECTION. AT LEAST THE SOUTHERN HALF OF THE FORECAST AREA COULD BE IN THE WARM SECTOR...BEFORE OCCLUDED FRONT PUSHES IN FROM THE SOUTHWEST...AND DRY AIR PUSHES INTO THE MID LEVELS AROUND THE MATURE CLOSED UPPER LOW. THEN DRY AIR WILL SHUT OFF THUNDERSTORM...AND SHOWER POTENTIAL THIS EVENING. WINDS SHIFTED TO SOUTHWEST WITH GUSTS TO 33 KNOTS WITH OCCLUSION. WRAP AROUND PRECIP EXPECTED ON SATURDAY AS UPPER LOW OPENS AND RESULTANT TROUGH MOVES ACROSS WISCONSIN AND NORTHERN ILLINOIS. SHORTWAVE ON GFS FOR SUNDAY NIGHT IS NOT AS PRONOUNCED AS YESTERDAY AND IS IN FAIR AGREEMENT WITH ECMWF. BOTH 12Z GFS AND 12Z ECMWF HAVE A WEAK SURFACE TROUGH MOVING THROUGH MONDAY. BOTH NAM AND GFS HAVE STEEP LAPSE RATES...CAPES NEAR 700 OFF THE GFS. THEREFORE WILL GO WITH A SMALL CHANCE OF SHOWERS. .LONG TERM... NEW ECMWF IS NOW TRENDING TOWARD THE GFS IN THE MID/LATE PERIODS. THEREFORE WILL TREND WETTER FOR TUESDAY/TUESDAY NIGHT. && .AVIATION...MAIN ISSUE FOR TAFS THROUGH 00Z SUNDAY IS EXPECTED CONVECTION LATE THIS AFTERNOON AND TONIGHT. THUNDERSTORMS AND ASSOCIATED MVFR/IFR CEILINGS AND VISIBILITIES ASSOCIATED WITH LOW LEVEL JET NOSE PUSHING NORTHEAST OF THE AREA. NEXT ROUND OF THUNDERSTORMS EXPECTED BETWEEN 20Z FRIDAY AND 02Z SATURDAY...AS COLD FRONT PUSHES ACROSS SOUTHERN WISCONSIN. EXPECT PREVAILING MVFR CEILINGS AND VISIBILITIES WITH THUNDERSTORMS...WITH SOME IFR VISIBILITIES AND CEILINGS POSSIBLE IN STRONGEST STORMS. WINDS GRADUALLY INCREASE IN MAGNITUDE AND SHIFT TO THE SOUTHWEST AND WEST ON SATURDAY. MVFR CEILINGS AND SCATTERED RAIN SHOWERS ARE EXPECTED AS UPPER LOW SHIFTS ACROSS THE AREA. && .MARINE...STABLE MARINE LAYER EXPECTED TO PREVENT MIXING OF WINDS ALOFT DOWN TO THE SURFACE TONIGHT AND SATURDAY. THIS SHOULD KEEP WINDS BELOW SMALL CRAFT ADVISORY CRITERIA...DESPITE AN INCREASING SURFACE PRESSURE GRADIENT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ SHORT/LONG TERM...HENTZ AVIATION/MARINE...WOOD wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 124 AM EDT SUN MAY 4 2008 .SHORT TERM.../THE REST OF TONIGHT/ A FEW MINOR CHANGES WERE MADE TO THE FORECAST FOR THE REST OF TONIGHT. LATEST SURFACE OBS INDICATE THAT HOURLY TEMPERATURES HAVE A BEEN JUST SLIGHTLY SLOWER TO FALL THAN PREVIOUSLY FORECAST...SO ADJUSTMENTS WERE MADE TO ACCOUNT FOR THIS WITH A GENERAL DEGREE OR TWO INCREASE IN HOURLY TEMPERATURES THROUGH 12Z. ALSO INCREASED OVERNIGHT LOW TEMPERATURES BY A DEGREE OR TWO ACROSS THE BOARD PER THE AFOREMENTIONED SURFACE OB TRENDS AND TOWARD THE 18Z SLIGHTLY WARMER MAVMOS NUMBERS. ALSO REMOVED MENTION OF PRECIPITATION FROM THE OVERNIGHT PERIOD AS CURRENT RADAR IMAGERY INDICATES THAT ANY REMAIN ISOLATED RAIN SHOWERS WILL HAVE MOVED OUT OF EASTERN KENTUCKY BY 3Z. THERE WAS ALSO A BIT OF EVENING AND OTHER OUTDATED WORDING IN THE FIRST PERIOD OF THE ZONES...SO ALL OF THAT WAS REMOVED AS WELL AND REPLACED WITH FRESH WORDING. ALSO RERAN THE WEATHER AND QPF FORECASTS TO REFLECT THE CHANGES MADE TO OVERNIGHT PRECIPITATION CHANCES. WINDS WILL STAY STRONG AND PERSISTENT ENOUGH TO KEEP FOG OUT OF THE PICTURE TONIGHT. REST OF FORECAST WAS IN GOOD SHAPE. UPDATED ZONES ALREADY OUT. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /TONIGHT THROUGH MONDAY NIGHT/ THE OCCLUDED FRONT HAS COMPLETED IT/S TRACK THROUGH EASTERN KENTUCKY. HOWEVER...SURFACE TROUGH STILL HAS TO MAKE IT THROUGH THE AREA. THIS SFC BOUNDARY IS CURRENT SLIDING THROUGH SOUTHEASTERN INDIANA AND WEST CENTRAL KENTUCKY. A BAND OF SHOWERS...AND THUNDERSTORMS HAVE DEVELOPED AHEAD OF THIS BOUNDARY WITH THE AID OF SURFACE HEATING IN A CLEARING SLOT BETWEEN THE TWO FEATURES. UNFORTUNATELY...SHORT TERM MODELS DO NOT HAVE A VERY GOOD HANDLE ON THE WEATHER ASSOCIATED WITH THE TROUGH. SO FORECAST CHALLENGE WILL FOCUS ON THE POTENTIAL FOR WEATHER AS THE SURFACE TROUGH ENTERS EASTERN KENTUCKY LATE LATE THIS AFTERNOON AND EARLY EVENING. MORE SPECIFICALLY...WILL ONGOING SHOWER ACTIVITY CONTINUE TO DEVELOP SOUTHWARD ALONG THE TROUGH AS IT MOVES INTO EASTERN KENTUCKY. GOES SOUNDING DATA INDICATES A WEAK MID LEVEL CAP IN PLACE AHEAD OF THE LINE OF SHOWERS AND THUNDERSTORMS IN SE INDIANA...BECOMING SLIGHTLY STRONGER FURTHER SOUTH IN SOUTH CENTRAL KENTUCKY. SATELLITE LOOP SHOWS SOME PARTIAL CLEARING BEGINNING TO WORK IT/S WAY INTO EASTERN KENTUCKY AS WELL. RUC MESOANALYSIS SEEMS TO HAVE PICKED UP ON THE PARTIAL CLEARING AS IT SHOWS AN INCREASE IN SFC BASED INSTABILITY...FROM 0 TO -3 LATE THIS AFTERNOON AS WELL AS AN INCREASE IN CAPE...FROM 50 TO 400 J/KG. WHILE NOT IMPRESSIVE...THIS SHOULD BE ENOUGH TO GENERATE SOME SCATTERED SHOWERS AND POSSIBLY AN ISOLATED THUNDERSHOWER OR TWO AS THE TROUGH MOVES INTO THE AREA...DESPITE THE WEAK CAP. REGIONAL RADAR LOOP SEEMS TO CONFIRM THIS SCENARIO AS THERE IS A GRADUAL EXPANSION OF SHOWERS BUILDING TO THE SOUTH. WILL CARRY A 20 TO 40 POP FOR LATE THIS AFTERNOON...AND EARLY EVENING TO COVER ANY POSSIBLE DEVELOPMENT. HIGHER POPS WILL BE CARRIED IN THE NORTH...WHILE LOWEST POPS ARE RESTRICTED TO THE SOUTHWEST. THE THREAT OF PRECIP SHOULD END THIS EVENING WITH LOSS OF SFC HEATING. DRY WEATHER WITH SEASONABLE TEMPS WILL PERSIST THROUGH THE REMAINDER OF THE SHORT TERM PERIOD. MONDAY MORNING WILL BE CHILLY IN THE VALLEYS AND AGAIN TUESDAY MORNING IN THE EAST. MOST LIKELY NIGHT FOR A STRONG RIDGE VALLEY SPLIT WILL BE MONDAY NIGHT AS A WEAK SE GRADIENT WIND BEGINS TO DEVELOP ON THE WEST SIDE OF HIGH PRESSURE. OTHERWISE...USED A BLEND OF MOS GUIDANCE FOR HIGHS. CLOSER TO THE COOLER MET FOR MONDAY UNDER NORTHERLY FLOW...AND CLOSER TO THE WARMER MAV ON TUESDAY UNDER SOUTHERLY FLOW. .LONG TERM.../TUESDAY THROUGH SATURDAY/ THERE ARE SOME DIFFERENCES IN THE MODELS FOR THE LONG TERM PERIOD. GENERALLY SIDED CLOSER TO THE ECMWF AND HPC MANUAL PROGS THROUGH THE PERIOD. THE THE EARLY PORTION OF THE FORECAST PERIOD SHOULD BE DRY...AS HIGH PRESSURE OVER THE SOUTHEAST CONUS KEEPS US DRY. BY WEDNESDAY...A LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS...WITH ANOTHER LOW OVER THE GREAT LAKES REGION. A COLD FRONT IN BETWEEN THE LOWS WILL DROP SOUTH DURING THE DAY...INCREASING THE CHANCE FOR SHOWERS AND THUNDERSTORMS. THE FRONT SHOULD STALL OUT AND BEGIN TO MOVE BACK NORTH AS A WARM FRONT WEDNESDAY NIGHT AS THE LOW OVER THE PLAINS MOVES EAST. THIS LOW SHOULD THEN MOVE OVER KENTUCKY LATE THURSDAY AND THURSDAY NIGHT. THIS WILL KEEP THE CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE AREA. THE LOW SHOULD BE EXITING OFF TO THE EAST FRIDAY...BUT SHOULD STILL BE CLOSE ENOUGH TO KEEP A CHANCE OF SHOWERS IN THE AREA. DRY WEATHER IS EXPECTED FRIDAY NIGHT AND SATURDAY AS HIGH PRESSURE BUILDS IN OVER THE AREA. && .AVIATION.../06Z TO 06Z/...UPDATED FRONTAL BOUNDARY IS NOW WELL TO OUR EAST WITH HIGH PRESSURE BUILDING INTO THE REGION FROM THE WEST. ONE BAND OF STRATOCU WILL SHIFT FROM WEST TO EAST ACROSS THE AREA OVER THE NEXT COUPLE OF HOURS AND THIS WILL BRINGS CIGS THAT TEETER AROUND THE 3K FT LEVEL. ONCE THIS PUSHES EAST... VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH LIGHT AND VARIABLE SURFACE WINDS. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...RAY/AR LONG TERM...WJM AVIATION...ABE ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 502 AM EDT SUN MAY 4 2008 .SYNOPSIS... HIGH PRESSURE LOCATED NORTHEAST OF THE STATE WILL CONTINUE TO WEAKEN AND MOVE TO THE EAST. LOW PRESSURE APPROACHING FROM THE WEST WILL BRING RAIN TO THE STATE TODAY AND TONIGHT. ANY LINGERING SHOWERS WILL THEN MOVE TO THE EAST EARLY MONDAY...WHILE HIGH PRESSURE BUILDS TOWARD THE REGION. && .NEAR TERM /THROUGH TONIGHT/... HIGH PRESSURE OVER THE MARITIMES IS CURRENTLY WEAKENING AND MOVING TO THE EAST. AT THE SAME TIME LOW PRESSURE IS APPROACHING FROM THE WEST ALONG WITH AN UPPER LEVEL TROF. INITIALLY SOME OF THE PRECIPITATION IS DRYING UP AS IT MOVES INTO THE RIDGE BUT EXPECT LOW LEVELS TO BECOME MORE SATURATED WITH TIME. SKY/POP...QPF GRIDS FROM PREVIOUS SHIFT FOR TODAY STILL LOOK REASONABLE AND HAVE NOT MADE ANY MAJOR CHANGES. HAVE ADJUSTED SKY COVER IN NORTH TO BETTER FIT OBSERVATIONS. FOR TEMPERATURE...DEW POINT AND WIND HAVE USED GMOS. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... LOW PRESSURE WILL MOVE EAST OF NOVA SCOTIA MONDAY...WHILE A FRONTAL BOUNDARY ALSO MOVES EAST OF THE REGION. SHOWERS COULD LINGER EARLY MONDAY...WITH SHOWER CHANCES THEN DIMINISHING FROM WEST TO EAST WHILE HIGH PRESSURE BUILDS ACROSS THE REGION. HIGH PRESSURE WILL THEN RIDGE ACROSS THE REGION MONDAY NIGHT THROUGH TUESDAY NIGHT. A WEAK COLD FRONT CROSSING THE REGION TUESDAY COULD BRING A FEW SHOWERS...PARTICULARLY ACROSS THE NORTH/MOUNTAINS. OTHERWISE...GENERALLY EXPECT PARTLY CLOUDY TO MOSTLY CLEAR SKIES ACROSS THE FORECAST AREA MONDAY NIGHT THROUGH TUESDAY NIGHT. TEMPERATURES WILL BE AT NEAR NORMAL TO SLIGHTLY ABOVE NORMAL LEVELS MONDAY/TUESDAY. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... HIGH PRESSURE WILL MOVE TO THE EAST EARLY WEDNESDAY...WITH LOW PRESSURE APPROACHING FROM THE WEST LATER WEDNESDAY. CLOUD COVER WILL INCREASE WEDNESDAY...WITH A CHANCE OF SHOWERS DURING THE AFTERNOON. THE LOW SHOULD TRACK ACROSS...OR JUST NORTH OF...THE FORECAST AREA WEDNESDAY NIGHT BRINGING A STEADIER RAIN. THE UPPER LOW WILL THEN CROSS THE REGION THURSDAY KEEPING A CHANCE OF SHOWERS ACROSS THE REGION. UPPER LEVEL TROFFING THEN PERSISTS FRIDAY INTO SATURDAY WHICH COULD HELP KEEP UNSETTLED CONDITIONS ACROSS THE REGION WITH A CHANCE OF SHOWERS...PARTICULARLY ACROSS THE NORTH/MOUNTAINS. TEMPERATURES WILL BE AT SLIGHTLY ABOVE NORMAL LEVELS WEDNESDAY...WITH NEAR NORMAL LEVEL TEMPERATURES THURSDAY THROUGH SATURDAY. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... NEAR TERM: CONDITIONS ARE EXPECTED TO LOWER TO IFR LEVELS ACROSS THE ENTIRE REGION TODAY...THEN PERSIST EARLY TONIGHT...WHILE LOW PRESSURE MOVES ACROSS THE STATE AND A SOUTHEAST FLOW BRINGS MOIST AIR INTO THE REGION. CONDITIONS SHOULD IMPROVE TO MVFR LEVELS LATER TONIGHT. SHORT TERM: MVFR CONDITIONS AND SHOWERS COULD OCCUR AT TIMES EARLY MONDAY. OTHERWISE...GENERALLY VFR CONDITIONS ARE EXPECTED LATER MONDAY THROUGH EARLY WEDNESDAY. CEILINGS/VISIBILITIES WILL THEN BEGIN TO LOWER WEDNESDAY AFTERNOON WITH DEVELOPING RAIN AND SHOWERS...WITH REDUCED CEILINGS/VISIBILITIES PERSISTING INTO THURSDAY PARTICULARLY ACROSS THE NORTH AND MOUNTAINS. && .MARINE... NEAR TERM: HAVE INITIALIZED WIND GRIDS WITH RUC13 OUT TO 12 HOURS THEN TRANSITION TO 50/50 BLEND OF THE NAM12 AND THE GFS40. ALSO HAVE LOWERED ALL MODEL WINDS FEW KNOTS SINCE A HIGH BIAS IS EXPECTED IN THE SOUTHEAST FLOW. FOR WAVES: SYSTEM TO THE SOUTHEAST OF NEW ENGLAND IS PRODUCING SOUTHEAST SWELL. BASED ON MODEL GRAPHICS EXPECT MOST OF THIS TO BE CONFINED TO MARINE ZONE ANZ051 ONLY AND WILL ISSUE AN SCA FOR SEAS FOR THIS AREA. MAXIMUM SWELL EXPECTED TO STAY SOUTH OF ANZ050 AND WILL NOT GET INTO INTRA-COASTAL ZONE. ALSO SEEMS TO BE 1 FOOT LOW BIAS IN WNA WAVE GUIDANCE SO HAVE ADJUSTED ACCORDINGLY. SHORT TERM: SMALL CRAFT ADVISORY LEVEL SEAS ARE POSSIBLE MONDAY. WINDS/SEAS ARE THEN EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS MONDAY NIGHT THROUGH EARLY WEDNESDAY. SMALL CRAFT ADVISORY LEVEL SEAS ARE THEN EXPECTED LATER WEDNESDAY THROUGH THURSDAY. VISIBILITIES COULD BE REDUCED IN SHOWERS MONDAY MORNING. VISIBILITIES WILL THEN BE REDUCED IN RAIN AND SHOWERS WEDNESDAY AFTERNOON THROUGH THURSDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 8 AM THIS MORNING TO 6 AM EDT MONDAY FOR ANZ051. && $$ NEAR TERM...MIGNONE SHORT TERM...NORCROSS LONG TERM...NORCROSS AVIATION...MIGNONE MARINE...MIGNONE/NORCROSS me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 345 AM EDT SUN MAY 4 2008 .SYNOPSIS... HIGH PRESSURE WILL BE IN CONTROL THROUGH TUESDAY. THE WEATHER PATTERN TURNS UNSETTLED FOR THE WEDNESDAY THROUGH FRIDAY TIME PERIOD...AS A FRONTAL BOUNDARY MEANDERS IN OUR VICINITY. && .NEAR TERM /THROUGH MONDAY/... THE COLD FRONT CLEARED THE AREA OVERNIGHT. BACK EDGE OF THE POST FRONTAL COLD AIR ADVECTION STRATUS DECK AT 4 AM STRETCHES FROM OUR NORTHEAST KENTUCKY ZONES...THROUGH CENTRAL OHIO. THIS DECK CORRESPONDS WELL TO THE 900MB RELATIVE HUMIDITY PATTERN OF THE RUC13 MODEL...AND I USED THE FORECAST OF THIS PARAMETER TO DEPICT THE QUICK WEST-TO-EAST BREAK UP OF CLOUDS THROUGH MIDDAY. DECENT MIXING WINDS LASTED THROUGH MOST OF THE NIGHT...BUT HIGH PRESSURE IS CHARGING QUICKLY IN FROM WESTERN KENTUCKY /AS OF 4 AM...LEXINGTON WAS ALREADY CALM/. I PUT A LITTLE EXTRA ON THE WINDS FOR THIS MORNING...BEFORE LETTING THEM DIMINISH THIS AFTERNOON. WITH WELL MIXED ATMOSPHERE...AND COLD AIR ADVECTION BRINGING IN 850MB TEMPS OF ONLY A COUPLE OR SO DEGREES ABOVE ZERO CELSIUS...ABILITY FOR DIURNAL WARMING SHOULD BE QUITE A BIT MUTED. I THUS LEANED STRONGLY TOWARDS THE COOLER MET GUIDANCE VERSUS THE MAV...ESPECIALLY IN THE EASTERN ZONES WHERE THE HIGHER MIXING WINDS /AND CLOUDS/ WILL LAST THE LONGEST. SURFACE HIGH PASSES DIRECTLY OVERHEAD TONIGHT...COMPLETE WITH STRONG SUBSIDENCE INVERSION AND VERY DRY MID LEVELS. THIS IS PERFECT FOR RADIATIONAL COOLING TO LEAD TO COOLER-THAN-GUIDANCE LOWS...AND SO MY FORECAST MINIMUM TEMPERATURES ARE GENERALLY EITHER AT OR A COUPLE DEGREES LOWER THAN COLDEST AVAILABLE GUIDANCE. WHILE FREEZING TEMPERATURES ARE NOT FORECAST...A TOUCH OF FROST IS NOT OUT OF THE QUESTION FOR THE USUAL SHELTERED COLD SPOTS IN OUR SOUTHEAST OH AND NORTHERN WV ZONES. HIGH PRESSURE AND FULL SUN WITH LIGHT WINDS MONDAY...AND THIS TIME PREFERRED THE WARMER MAV GUIDANCE FOR HIGH TEMPERATURES. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... A QUIET PERIOD AS HIGH PRESSURE DOMINATES. ONLY FEATURE WILL BE A DISSIPATING COOL FRONT DROPPING SOUTHEAST FROM THE GREAT LAKES TUESDAY...BUT WILL NOT MAKE IT INTO OUR AREA. THUS...ABOVE NORMAL TEMPERATURES AND DRY WEATHER IS EXPECTED. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... A 500HPA TROUGH WILL KICK OUT OF THE SOUTH PLAINS REGION MID WEEK AND BRING A WARM FRONT TOWARDS THE OHIO RIVER VALLEY...WHILE SIMULTANEOUSLY...A COLD FRONT RIPS THROUGH THE GREAT LAKES. SOUTHWARD EXTENT OF THIS BOUNDARY WILL BE THE QUESTION INTO MID WEEK AS IT LOOKS TO STALL JUST NORTH OF THE CWA. WILL SEE AN INFLUX OF MOISTURE...BRINGING CLOUD COVER...AND ULTIMATELY...AN INCREASE IN RAIN CHANCES. LOOKS LIKE AN EERILY FAMILIAR SCENARIO WHERE RAIN SETS UP ALONG THE SOUTHEAST OHIO COUNTIES AS THIS FRONTAL BOUNDARY TRACKS ALONG ITSELF WHILE THE SURFACE LOW TO THE NORTHEAST DEPARTS INTO SOUTHERN QUEBEC AND THE SECONDARY SURFACE LOW APPROACHES THE CONFLUENCE OF THE OHIO AND MISSISSIPPI RIVERS. THIS WILL TRANSLATE INTO AN EXTENDED PERIOD OF GRAY SKIES AND DAMP CONDITIONS FOR MOST OF THE CWA...AND WILL EXPECT THE PARENT 500HPA TROUGH TO MOVE INTO THE FORECAST AREA FRIDAY. AN UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE MAY MAKE ITS WAY IN JUST IN TIME FOR THE UPCOMING WEEKEND AND DRY THINGS OUT. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... A COLD FRONT CLEARED THE AREA JUST PRIOR TO 06Z...AND HIGH PRESSURE IS QUICKLY BUILDING IN. COLD AIR ADVECTION WILL YIELD A POST FRONTAL STRATUS DECK THAT COULD DIP INTO MVFR CATEGORY FOR THE MOUNTAIN TERMINALS FOR A FEW HOURS THIS MORNING...ESPECIALLY KBKW. OTHER THAN THAT EXCEPTION...VFR EXPECTED THROUGH THE TAF PERIOD FOR ALL TERMINALS. AVIATION OUTLOOK /AFTER 06Z MONDAY/...STRONG SURFACE HIGH PASSING DIRECTLY OVERHEAD...COULD LEAD TO FOG WITH A FEW HOURS OF IFR VIS AT KEKN BETWEEN 06Z-12Z MONDAY AT KEKN AND PERHAPS MVFR IN OTHER VALLEY TERMINALS. BEYOND THAT...NO SIG WX ANTICIPATED UNTIL THE NEXT FRONT COMES DURING THE WEDNESDAY-THURSDAY TIME PERIOD. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...MDP/JMV NEAR TERM...MDP SHORT TERM...JMV LONG TERM...JMV AVIATION...MDP oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 127 AM EDT SUN MAY 4 2008 .SYNOPSIS... HIGH PRESSURE WILL BE IN CONTROL SUNDAY TO WEDNESDAY. UNSETTLED WEATHER AND THE NEXT CHANCES FOR RAIN COMMENCE FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... UPDATED FORECAST AROUND MIDNIGHT TO CLEAR ALL POPS EXCEPT EXTREME EASTERN ZONES /ONLY LASTING ANOTHER HOUR OR SO THERE/. SKY FORECAST UPDATED USING 900MB RH LEVELS FROM THE RUC13 MODEL. && .SHORT TERM /7 AM THIS MORNING THROUGH TUESDAY/... LOW LEVEL MOISTURE IN WEAK NORTHWESTERLY FLOW TRIES TO HANG ON AS LONG AS POSSIBLE INTO THE SHORT TERM PORTION OF THE FORECAST. AT THIS POINT...SUSPECT IT WILL NOT DO MUCH IN THE WAY OF CLOUD COVER SUNDAY NIGHT...AND SHOULD SEE GENERALLY CLEAR CONDITIONS BY MORNING...BUT ENOUGH MOISTURE SHOULD HANG AROUND FOR THE HEATING PERIOD OF MONDAY AND GIVE SOME FLAT LOW TOPPED FAIR WEATHER CUMULUS. 500HPA TROUGH FINALLY SPINS AWAY INTO EASTERN CANADA...AND ZONAL FLOW RETURNS AS SURFACE HIGH PRESSURE NUDGES ITS WAY IN. IN ADDITION...WILL BE WATCHING A SHORT WAVE TROUGH DEVELOP IN THE ZONAL FLOW AND PASS THROUGH THE CENTRAL APPALACHIANS INTO THE PIEDMONT AREA MONDAY...AND WILL BE A FAST MOVER. SHOULD NOT SEE ANY PRECIP WITH THIS...BUT COULD PLAY HAVOC WITH THE SKY IN ADDITION TO THE AFOREMENTIONED FAIR WEATHER CUMULUS MONDAY AFTERNOON. ALL IN ALL...STILL SHOULD SEE A MIX OF THE SUN AND CLOUDS MONDAY GIVEN INFLUENCES OF SURFACE HIGH PRESSURE. A SLOW RECOVERY IN THE TEMPERATURES WILL CONTINUE THROUGH TUESDAY. THE CENTRAL AREA OF HIGH PRESSURE WILL TAKE ITS TIME MOVING EASTWARD...BRINGING THE RETURN FLOW ACCOMPANIED BY THE INFLUENCES OF THE NEXT SYSTEM OFF TO THE WEST. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A 500HPA TROUGH WILL KICK OUT OF THE SOUTH PLAINS REGION MID WEEK AND BRING A WARM FRONT TOWARDS THE OHIO RIVER VALLEY...WHILE SIMULTANEOUSLY...A COLD FRONT RIPS THROUGH THE GREAT LAKES. SOUTHWARD EXTENT OF THIS BOUNDARY WILL BE THE QUESTION INTO MID WEEK AS IT LOOKS TO STALL JUST NORTH OF THE CWA. WILL SEE AN INFLUX OF MOISTURE...BRINGING CLOUD COVER...AND ULTIMATELY...AN INCREASE IN RAIN CHANCES. LOOKS LIKE AN EERILY FAMILIAR SCENARIO WHERE RAIN SETS UP ALONG THE SOUTHEAST OHIO COUNTIES AS THIS FRONTAL BOUNDARY TRACKS ALONG ITSELF WHILE THE SURFACE LOW TO THE NORTHEAST DEPARTS INTO SOUTHERN QUEBEC AND THE SECONDARY SURFACE LOW APPROACHES THE CONFLUENCE OF THE OHIO AND MISSISSIPPI RIVERS. THIS WILL TRANSLATE INTO AN EXTENDED PERIOD OF GRAY SKIES AND DAMP CONDITIONS FOR MOST OF THE CWA...AND WILL EXPECT THE PARENT 500HPA TROUGH TO MOVE INTO THE FORECAST AREA FRIDAY. AN UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE MAY MAKE ITS WAY IN JUST IN TIME FOR THE UPCOMING WEEKEND AND DRY THINGS OUT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... A COLD FRONT CLEARED THE AREA JUST PRIOR TO 06Z...AND HIGH PRESSURE IS QUICKLY BUILDING IN. COLD AIR ADVECTION WILL YIELD A POST FRONTAL STRATUS DECK THAT COULD DIP INTO MVFR CATEGORY FOR THE MOUNTAIN TERMINALS FOR A FEW HOURS THIS MORNING...ESPECIALLY KBKW. OTHER THAN THAT EXCEPTION...VFR EXPECTED THROUGH THE TAF PERIOD FOR ALL TERMINALS. AVIATION OUTLOOK /AFTER 06Z MONDAY/...STRONG SURFACE HIGH PASSING DIRECTLY OVERHEAD...COULD LEAD TO FOG WITH A FEW HOURS OF IFR VIS AT KEKN BETWEEN 06Z-12Z MONDAY AT KEKN AND PERHAPS MVFR IN OTHER VALLEY TERMINALS. BEYOND THAT...NO SIG WX ANTICIPATED UNTIL THE NEXT FRONT COMES DURING THE WEDNESDAY-THURSDAY TIME PERIOD. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...26/ARJ NEAR TERM...MDP SHORT TERM...26 LONG TERM...26 AVIATION...MDP oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 915 AM PDT SUN MAY 4 2008 .DISCUSSION... TWO LOW PRESSURE AREA ARE EVIDENT THIS MORNING IN THE WATER VAPOR IMAGE. ONE OFF THE THE SOUTHERN CALIFORNIA COAST AND ANOTHER ONE MOVING INTO NORTHWEST CALIFORNIA THIS MORNING. THIS SECOND LOW WILL CONTINUE TO DROP SOUTHWARD DURING THE DAY. MODELS ARE INDICATING INCREASED INSTABILITY OVER THE MOUNTAINS. NAM AND RUC MODEL INDICATE THE BEST CHANCES ALONG THE CREST FROM SOUTH OF PLUMAS COUNTY THIS AFTERNOON AND EVENING...WITH THE GFS INDICATING CHANCES EXTENDING UP INTO SHASTA COUNTY. HAVE INCREASED PRECIPITATION CHANCES FOR TODAY AS A RESULT. HAVE ALSO INCLUDED SOME SLIGHT CHANCES FOR LATE THIS AFTERNOON AND EARLY EVENING FOR THE MOTHERLODE. EASTERLY FLOW OVER THE SIERRA NEVADA THIS AFTERNOON LOOKS STRONG ENOUGH TO CARRY THE ACTIVITY SOUTHWARD INTO THE FOOTHILLS THUNDERSTORMS OVER THE HIGHER ELEVATIONS LOOK LIKE THEY SHOULD CONTAIN A FAIR AMOUNT OF PRECIPITATION WITH THEM...BUT AS YOU MOVE AWAY FROM THE CREST THE AMOUNT OF PRECIPITATION ASSOCIATED WITH THE THUNDERSTORMS LOOK LIMITED. THE ACTIVITY WILL DIE DOWN THIS EVENING AS THE SUN GOES DOWN AND THE ATMOSPHERE STABILIZES. && .AVIATION... PREDOMINATELY VFR CONDITIONS ARE EXPECTED ACROSS INTERIOR NORTHERN CALIFORNIA THROUGH TOMORROW EXCEPT CUMULUS BUILDING OVER THE HIGHER TERRAIN THIS AFTERNOON AND EVENING (UNTIL 03Z) POSSIBLY BRINGING ISOLATED SHOWERS AND THUNDERSTORMS WITH ISOLD MVFR CONDITIONS. THE WAVE MOVING THROUGH TODAY WILL COMBINE WITH THE LOW TO THE SOUTH AND REMAIN OFF THE SOUTHERN CALIFORNIA COAST TOMORROW WHILE A WEAK RIDGE BUILDS IN OVER NORTHERN CALIFORNIA. THE RIDGE WILL CONTINUE THE VFR CONDITIONS WITH SOME AFTERNOON AND EVENING CUMULUS PROBABLY REDEVELOPING AGAIN TOMORROW AFTERNOON...MAINLY OVER THE SIERRA. && .STO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ca EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 951 AM EDT SUN MAY 4 2008 .DISCUSSION... THIS AFTERNOON...HAVE BEEN AWAITING THE LATEST SOUNDING AT XMR WHICH NOW SHOWS SOME ADT`L MOISTENING OF THE ATMOSPHERE SINCE SATURDAY (UP TO 1.45 INCHES OF PWAT). TEMPS HAVE ALSO COOLED BY AROUND 4C @ H7 DURING THE PAST 20 HOURS. SW-W WIND PROFILE AT STEERING LEVEL FAVORS THE CENTRAL TO EASTERN SIDE OF PENINSULA FOR DEVELOPMENT OF DIURNALLY BASED SHOWERS AND PERHAPS A STORM OR TWO BY LATE AFTERNOON. THE LOCALLY GENERATED 8KM WRF RUN FROM 09Z IS INDICATING A LARGE SCALE BOUNDARY MERGER OVER THE INTERIOR LATE THIS AFTERNOON AND THIS IS SUPPORTED AS WELL BY THE 12Z 13KM RUC. A RATHER LIGHT ENVIRONMENTAL SFC WIND THIS MORNING WL LEAD TO THE DEVELOPMENT OF LOCALIZED BOUNDARIES AND WOULD EXPECT DEVELOPMENT OF SOME PRECIPITATION DURING THE HEAT OF THE AFTERNOON...ESP AFTER THE LARGER SCALE BREEZE MERGER AFTER 20Z AS THE EAST COAST BREEZE INTERACTS OVER THE INTERIOR. WV IMAGERY INDICATED A WEAK IMPULSE ALOFT WHICH WL ADD TO CONVECTIVE POTENTIAL THIS AFTERNOON. WL UPDATE FCST TO REFINE THUNDER POTENTIAL AS WELL AS A FEW OTHER WORDING ADJUSTMENTS. && .AVIATION... PRIMARILY VFR THROUGH 19Z WITH ISOLD THUNDER PSBL LATE AFTERNOON. LOCALIZED MVFR/IFR PSBL AFT 20Z NEAR SHOWERS AND STORMS WITH COVERAGE AROUND 20 PERCENT. && .MARINE...NO SIG CHANGES PLANNED. PRIMARILY WIND WAVE WITH WINDS AND SEAS LOCALLY HIGHER LATE THIS AFTERNOON NEAR A FEW SHOWERS OR STORMS. && .FIRE WEATHER... MIN RH VALUES LOOK TO FALL INTO THE LOW TO MID 30S OVER THE PORTIONS OF THE INTERIOR ON MONDAY. WE WILL EVALUATE A POSSIBLE HEADLINE FOR MONDAY BY THE AFTERNOON ISSUANCE. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ JP/DWS fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 1221 PM EDT SUN MAY 4 2008 .SYNOPSIS... HIGH PRESSURE OVER THE SOUTHERN PLAINS WILL BUILD INTO THE AREA TODAY AND THEN MOVE EAST ACROSS THE REGION ON MONDAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA TUESDAY NIGHT. A COLD FRONT WILL THEN SWEEP EAST ACROSS THE FORECAST AREA ON WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... QUICK UPDATE. MINOR ADJUSTMENTS FOR WINDS. ALSO CHANGED SKY CONDITION FROM PC TO MOSTLY SUNNY ACROSS THE WEST HALF OF THE AREA. BOTH THE RUC AND THE NAM SHOW 850MB LEVELS MOISTENING THIS AFTERNOON IN THE WEST HOWEVER BUFKIT FORECAST SOUNDINGS SHOW THAT LEVELS ABOVE AND BELOW ARE VERY DRY. WHILE WE COULD GET CUMULUS QUICKLY DEVELOPING IN THE AFTERNOON BELIEVE WITHIN AN HOUR OR TWO THAT SIGNIFICANT DRY AIR ENTRAINMENT WL KEEP CLOUDS SCATTERED. GIVEN THIS WILL HIGHLIGHT THE SUN ASPECT VS THE CLOUDS. FURTHER EAST WITH LAKE 850MB TEMPS CLOSER TO 10 OR 11C WILL KEEP PC. NO OTHER CHANGES. PREVIOUS...CLOUDS ARE QUICKLY MOVING EAST AND OUT OF THE AREA SETTING UP FOR A DAY OF LOTS OF SUNSHINE TODAY. ONLY FLY IN THE OINTMENT IS THE CUMULUS RULE SHOWS SCATTERED TO BROKEN CLOUDS OVER THE AREA TODAY THANKS TO RESIDUAL MOISTURE IN THE SOIL LEFTOVER FROM ALL THE PREVIOUS RAIN. LATEST RADAR SHOWS A FEW SPRINKLES HEADING EAST FROM THE CANADIAN SHORE TOWARD ERIE PENNSYLVANIA. THIS ACTIVITY SHOULD BE INTO AND THROUGH ERIE BY 7 AM IN THE MORNING SO WILL JUST HANDLE IT WITH NOWCASTS. TEMPERATURES EXPECTED TO BE ON THE COOL SIDE COMPARED TO LAST COUPLE DAYS AS COLD AIR ADVECTION TAKES PLACE. EARLY MAY SUN WILL HELP BRING TEMPERATURES UP TO AROUND 60 IN MOST AREAS. AREAS CLOSE TO THE COLD LAKE ERIE SHORE LINE WILL STRUGGLE TO GET OUT OF THE 50S TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... FAIR WEATHER CONTINUES TONIGHT AND AS HIGH PRESSURE SETTLES IN OVER THE AREA AND WINDS WILL DIMINISH. THIS WILL HELP TEMPERATURES DROP OVER THE EASTERN PORTIONS OF THE FORECAST AREA SETTING UP FOR SOME POSSIBLE PATCHY FROST AWAY FROM THE LAKE. WESTERN AREAS WILL SEE SOME WEAK WARM AIR ADVECTION AHEAD OF THE TRUE WARM FRONT AND THIS SHOULD HELP KEEP TEMPERATURES FROM BOTTOMING OUT NEAR FREEZING. SHORTWAVE TROUGH ALOFT MOVES QUICKLY THROUGH THE AREA WITH VERY LIMITED MOISTURE ON TUESDAY AND THIS FEATURE COULD KICK OFF A FEW SPRINKLES OR VERY LIGHT RAIN SHOWERS DURING THE DAY. WARM FRONT MOVES INTO THE REGION TUESDAY NIGHT AND MOISTURE ASSOCIATED WITH THE FRONT WILL BE LIMITED ONCE AGAIN. HOWEVER...INSTABILITY INCREASES ALONG THE FRONTAL BOUNDARY AND IN THE WARM AIR ADVECTION THAT IT WARRANTS AT LEAST A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY NIGHT. COLD FRONT MOVES THROUGH THE AREA WEDNESDAY AND WILL CONTINUE THE THREAT OF SHOWERS AND THUNDERSTORMS. POTENTIAL...WITH INSTABILITY...THAT SOME OF THE THUNDERSTORMS COULD REACH SEVERE LIMITS DEPENDING ON TIMING OF THE FRONT. WEDNESDAY NIGHT COLD AIR ADVECTION TAKES PLACE WITH RESIDUAL SCATTERED SHOWERS IN THE STABLE AIR NORTH OF THE WAVE OF LOW PRESSURE PROGGED TO MOVE EAST ACROSS THE OHIO VALLEY. PROBLEM WITH THE FORECAST GOING INTO THE EXTENDED PERIODS IS THE COLD FRONT BECOMES NEARLY STATIONARY JUST SOUTH OF THE FORECAST AREA. && .LONG TERM /THURSDAY THROUGH SATURDAY/... BOUNDARY OVER EXTREME SOUTHERN OHIO AND NORTHERN KENTUCKY THURSDAY WITH LOW MOVING ALONG IT. WITH SOME RIDGING EXTREME NORTH ESPECIALLY BY THE GFS THE QUESTION IS HOW FAR NORTH WILL THE PRECIPITATION BE...WITH SOME QUESTIONS KEPT THE THREAT OVER THE ENTIRE AREA THROUGH THURSDAY NIGHT. THE 00Z ECMWF AGREES WITH THE GFS ON THIS. FOR FRIDAY THE GFS REALLY DRIES THINGS OUT WHILE THE ECMWF DOESN`T ON THIS RUN...IT IS SLOWER IN BUILDING IN THE HIGH...NOT SURE WHY THIS IS THE CASE. AT THE MOMENT WILL STILL GO WITH THE GFS IN BUILDING THE HIGH IN. THE ECMWF ON SATURDAY STILL HAS SOME SHOWERS AROUND WHILE THE GFS IS DRY WITH THE HIGH IN PLACE. AGAIN GOING DRY. DID A MIX OF MEX...GRIDDED MOS AND LOCAL SCHEME FOR TEMPERATURES. QUESTION WITH THE SKY COVER WHAT THE TEMPERATURES WILL DO. && .AVIATION /18Z SUNDAY THROUGH THURSDAY/... HIGH PRESSURE SLIDING ACROSS THE AREA TODAY AND MOVING JUST OFF TO THE SOUTH AND SOUTHEAST ON MONDAY WILL KEEP VFR WEATHER GOING THROUGH THE TAF FORECAST PERIOD...18Z MONDAY. ONLY EXPECTING SCT VFR CLOUDS THIS AFTERNOON. OUTLOOK...THE MAIN THREAT FOR SOME NON VFR CONDITIONS IN PRECIPITATION WILL BE TUESDAY THROUGH THURSDAY. A SHORT WAVE WILL MOVE ACROSS THE REGION TUESDAY WITH SOME SPOTTY SHOWERS. THE BETTER CHANCE FOR SOME NON VFR CONDITIONS IN PRECIPITATION WILL BE TUESDAY NIGHT AND WEDNESDAY AS A COLD FRONT MOVES ACROSS THE AREA. HOW FAR NORTH THE PRECIPITATION WILL BE THURSDAY IS A TOUGH CALL WITH THE FRONT OVER SOUTHERN OHIO AND LOW PRESSURE MOVING EAST ALONG THE FRONT FROM MISSOURI. && .MARINE... HIGH PRESSURE WILL BUILD RAPIDLY OVER THE LAKE TODAY. THE WINDS WILL DECREASE AND SWITCH TO THE NORTHWEST. THE SMALL CRAFT ADVISORY THROUGH 10 AM LOOKS GOOD. UNSETTLED WEATHER ACROSS THE AREA WITH A FRONT MOVING THROUGH WEDNESDAY AND THEN BECOMING STATIONARY ACROSS SOUTHERN OHIO THURSDAY WITH A LOW MOVING ALONG THE FRONT. HIGH PRESSURE WILL BUILD IN FRIDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED SOME TIME IN THE WEDNESDAY THROUGH THURSDAY PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ147>149. && $$ SYNOPSIS...LOMBARDY NEAR TERM...TK/LOMBARDY SHORT TERM...LOMBARDY LONG TERM...KIELTYKA AVIATION...RANDEL MARINE...KIELTYKA oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1026 AM CDT SUN MAY 4 2008 AFTER A QUICK SPIKE IN DEWPOINTS AFTER SUNRISE THIS MORNING... DEWPOINTS HAVE STARTED A DOWNWARD TREND IN MOST AREAS. 12Z RAOBS AND CLOSE PROXIMITY OF A LOWER/MID LEVEL ANTICYCLONE SUGGEST A LOWERING OF DEWPOINTS OR AT BEST A LEVELING OF DEWPOINTS IS LIKELY FOR THE AFTERNOON WHICH IS IN CONTRAST TO OUR GOING FORECAST. HAVE THEREFORE USED A BLEND OF THE DRIER RUC AND THE MORE MODEST NAM ALONG WITH LAPS TRENDS TO JUSTIFY CHANGES TO THE AFTERNOON DEWPOINT GRIDS. ALONG WITH CHANGES TO THE DEWPOINTS...THE PRESSURE GRADIENT AND MORE RAPID DEVELOPMENT OF A DEEPER MIXED PBL HAVE RESULTED IN SLIGHTLY STRONGER WINDS ACROSS NORTHWEST OKLAHOMA THAN PREVIOUSLY EXPECTED. SO AN INCREASE IN WINDS IS ALSO INTRODUCED INTO THE AFTERNOON GRIDS. THE PRIMARY RESULT OF THESE CHANGES IS INCREASES WILDFIRE POTENTIAL ACROSS NORTHWEST OKLAHOMA WHERE DORMANT VEGETATION CONTINUES. SPREAD INDICES ARE NOW FORECAST TO REACH 60 TO 65 WHICH IS JUST BELOW WHAT WOULD NORMALLY BE USED TO SUPPORT A RED FLAG WARNING. HOWEVER...WE WILL UPDATE OUR FIRE WEATHER FORECASTS TO EXPLAIN THE INCREASE IN THE WILDFIRE POTENTIAL. BEYOND THIS AFTERNOON...THE PRIMARY EMPHASIS CONTINUES TO BE THE SEVERE WEATHER POTENTIAL FOR MONDAY INTO MONDAY NIGHT AND AGAIN ON WEDNESDAY. MONDAY`S OUTLOOK REMAINS HIGHLY CONDITIONAL AS WEAK LIFTING OF MODERATELY UNSTABLE AIR MAY RESULT IN SCATTERED CONVECTION NEAR A LEE ROCKIES SURFACE LOW IN SOUTHWEST KANSAS AND PERHAPS FARTHER SOUTH ALONG THE TROUGH AXIS INTO WESTERN TEXAS. HIGH CLOUD BASES SUPPORT A GOOD PROBABILITY OF SIGNIFICANT COLD POOL DEVELOPMENT POTENTIAL WITH ANY STORMS THAT DEVELOP WITH SHEAR PROFILES AND MID/UPPER LEVEL ANTICYCLONIC FLOW SUPPORTIVE OF UPSCALE GROWTH INTO CLUSTERS MONDAY EVENING AND MONDAY NIGHT. AT THIS TIME...THIS SCENARIO APPEARS MOST LIKELY ACROSS KANSAS WITH A CHANCE OF SOME INFLUENCE ACROSS NORTHERN OKLAHOMA. WEDNESDAY`S SEVERE WEATHER POTENTIAL IS MORE LIKELY AS THE REGION RECEIVES STRONG INFLUENCE FROM AN APPROACHING UPPER LOW WITH STORMS POSSIBLY INITIATING BY MIDDAY NEAR A SURGING DRYLINE JUST WEST OF INTERSTATE 35. JAMES ------------------------- 405 AM CDT SUN MAY 4 2008 .DISCUSSION...UNSEASONABLY COOL MORNING ACROSS THE FA WITH TEMPS IN THE 30S IN NRN OK. TEMPS SHOULD RETURN CLOSER TO SEASONAL NORMS TODAY AS SFC RIDGE SLIDES EWD AND SOUTHERLY WINDS RETURN. LOW LEVEL RIDGE EXTENDING INTO THE GULF WILL KEEP INITIAL MOISTURE RETURN MAINLY SOUTH AND WEST OF THE FA THROUGH TODAY BUT BETTER MOISTURE SHOULD BEGIN TO SPREAD BACK INTO THE AREA TONIGHT AND MONDAY. BEST THUNDERSTORM CHANCES ON MONDAY WILL BE IN WESTERN AND SOUTHERN SECS WITH RETREATING FRONTAL BOUNDARY AND INCREASING MOISTURE INTERACTING WITH WEAK IMPULSES MOVE THROUGH. BEST INSTABILITY BY MONDAY AFTN EXPECTED FROM TX PANHANDLE INTO NW OK AS TEMPS HEAT WELL INTO THE 80S. STRONG/SEVERE STORMS WHICH INITIATE ON THE DRYLINE WEST OF THE AREA COULD MOVE INTO WESTERN PARTS OF OK DURING THE EVENING/OVERNIGHT. TUESDAY FORECAST IS A BIT TRICKY WITH SW UPPER SYSTEM STILL WELL TO THE WEST. MOIST AIRMASS WILL STILL BE IN PLACE BUT CAP WILL BE INCREASING. WILL GO ALONG WITH GFS TREND OF PUSHING MOST OF THE PRECIP OFF TO THE NORTHEAST OF THE AREA. MODELS HAVE BEEN FAIRLY CONSISTENT WITH EJECTING UPPER LOW FROM SRN ROCKIES INTO THE SOUTHERN PLAINS ON WEDNESDAY. THREAT AS THIS OCCURS SURFACE LOW EXPECTED TO MOVE FROM TX PANHANDLE INTO WRN/CNTRL OK BY WEDNESDAY AFTERNOON WITH DRYLINE EXTENDING SOUTHWARD INTO NORTH TEXAS AND COLD FRONT ADVANCING INTO NORTHWEST OKLAHOMA. MOISTURE WILL REMAIN IN PLACE AHEAD OF THESE FEATURES AND WITH STRENGTHENING WIND FIELDS THREAT OF STRONG/SEVERE STORMS WILL INCREASE. STORMS WILL MOVE OFF TO THE EAST OF THE AREA BY THURSDAY MORNING WITH A COUPLE OF DRY DAYS EXPECTED AS FRONT PUSHES SOUTH THROUGH TEXAS UPPER RIDGE REBUILDS OVER THE AREA. WILL RETURN POPS TO THE FORECAST FOR LATE IN THE PD WITH SWLY UPPER FLOW DEVELOPING AND FRONTAL BOUNDARY DRIFTING BACK NWD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 74 52 76 64 / 0 0 30 50 HOBART OK 78 54 75 63 / 0 10 30 40 WICHITA FALLS TXV 78 57 75 65 / 0 10 50 60 GAGE OK 81 53 82 63 / 0 10 20 20 PONCA CITY OK 72 48 76 65 / 0 0 10 30 DURANT OK 77 56 74 64 / 0 0 40 60 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR OKZ007-008-013- 020. TX...NONE. && $$ 30/02 ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 1033 AM CDT SUN MAY 4 2008 .UPDATE... MADE A FEW CHANGES TO THE GRIDS THIS MORNING...MOSTLY TO DECREASE WINDS. THE STRONGER WINDS ARE OVER NORTHWESTERN NORTH DAKOTA...WHICH ARE ON THE BACKSIDE OF A SURFACE LOW PRESSURE. THE LATEST RUC MODEL RUN SHOWS THIS LOW SLOWLY MOVING ESE TODAY...WITH WINDS OUT OF A MORE WESTERLY DIRECTION. HAVE ALSO INCREASE TEMPS A DEGREE IN THE NE CWA. REST OF THE FORECAST LOOKS GOOD. && .PREV DISCUSSION... .SHORT TERM...TODAY THROUGH TUESDAY FORECAST CHALLENGES INCLUDE TEMPERATURES AND PRECIPITATION CHANCES LATE MONDAY NIGHT AND DURING THE DAY ON TUESDAY. CURRENTLY...HIGH PRESSURE AT THE SURFACE RESIDES ACROSS THE FORECAST AREA. A SUBTLE LITTLE RATHER SLOW-MOVING COLD FRONTAL BOUNDARY IS TRYING TO BACK DOOR ITS WAY INTO THE FAR NORTHEASTERN FORECAST ZONES THIS MORNING. WEAK UPPER LEVEL S/WS WILL CONTINUE TO SHEAR APART AS THEY WORK THROUGH THE NORTHERN PLAINS IN NW FLOW ALOFT TODAY AND MONDAY. THIS SUBTLE LITTLE BOUNDARY IS EXPECTED TO REMAIN NEARLY STATIONARY TODAY BEFORE SAGGING SOUTHWARD INTO THE NORTHEASTERN HALF OF THE CWA TONIGHT. WITH BOUNDARY ORIENTED PARALLEL TO THE UPPER FLOW PATTERN...NOT EXPECTING DRAMATIC FLUCTUATIONS IN FRONTAL POSITION OVER THE NEXT 24 TO 36 HOURS. BY MONDAY AFTERNOON...THE BOUNDARY IS EXPECTED TO BEGIN RETREATING NORTHWARD IN RESPONSE TO THE SOMEWHAT STRONGER UPPER WAVE STILL EXPECTED TO WORK THROUGH THE DAKOTAS LATE MONDAY NIGHT AND TUESDAY. SO...REALLY NO CHANGES MADE TO GOING WX/POP FORECAST FOR MONDAY NIGHT AND TUESDAY. ALTHOUGH...LATEST RUNS OF THE EC AND GFS OPERATIONAL MODELS SUGGEST THAT THE MAJORITY OF PRECIPITATION POTENTIAL WILL SET UP EITHER NORTH OR EAST OF THIS AREA BY TUESDAY AFTERNOON. NEVERTHELESS...CONTINUED WITH THE SMALLISH CHANCES OF SHOWERS OR POSSIBLY EVEN A THUNDERSTORM IN ELEVATED INSTABILITY LAYER. TEMPERATURES WILL BE TRICKY TO NAIL DOWN AND HIGHLY DEPENDENT ON WHERE THIS FRONTAL BOUNDARY IS LOCATED EACH OF THE NEXT COUPLE OF DAYS COME PEAK-HEATING TIME. SOUTH AND WEST OF THE BOUNDARY...STILL EXPECTING QUITE A WARMUP /BACK TO AROUND NORMAL TO AS MUCH AS 10 DEGREES ABOVE NORMAL/ BY MONDAY AFTERNOON. NORTH AND EAST OF THE BOUNDARY IN LIGHT EAST OR NORTHEAST WINDS...TEMPERATURES MAY STRUGGLE TO RETURN TO CLIMO NORMALS TODAY AND MONDAY. LASTLY...EC AND GFS MODEL OUTPUT SEEMS TO SUGGEST THAT THE COLD PUSH BEHIND THE TUESDAY SYSTEM MAY HOLD OFF LONG ENOUGH ON TUESDAY TO ALLOW FOR SOME DECENT HEATING TO OCCUR...BEFORE CAA TAKES OVER TUESDAY AFTERNOON AND EVENING. THEREFORE...DID NUDGE MAX T VALUES UP A FEW DEGREES ACROSS MUCH OF THE CWA ON TUESDAY. .LONG TERM...TUESDAY NIGHT THROUGH SATURDAY MODELS AND GFS ENSEMBLES SHOW DECENT AGREEMENT AND CONSISTENCY WITH THE LONG TERM AS THE STRONG UPPER LEVEL LOW IN THE SOUTHWEST US BEGINS THE PERIOD AND TRAVELS TO THE SOUTH OF OUR REGION FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT KEEPING OUR AREA DRY. THE MODELS AND ENSEMBLES CONTINUE TO SHOW UPPER LEVEL TROUGHING DEVELOPING INTO THE PACIFIC NORTHWEST EARLY ON. SHORT WAVES COMING OFF OF THIS TROUGH WILL BRING MAINLY SLIGHT CHANCES OF SHRAS/TSRAS FOR WEDNESDAY NIGHT THROUGH FRIDAY TO MUCH OF THE CWA. A MORE SIGNIFICANT WAVE WILL BRING A BETTER CHANCE OF PRECIPITATION FOR FRIDAY NIGHT INTO SATURDAY AS SHOWN MAINLY BY THE GFS. MAY HAVE TO INCREASE POPS HERE EVEN MORE IN LATER FORECASTS. OTHERWISE...WITH THIS PACIFIC FLOW...TEMPERATURES SHOULD BE NEAR NORMAL FOR THIS TIME OF YEAR WITH HIGHS IN THE 60S AND LOWS IN THE 40S. MADE ONLY SMALL ADJUSTMENTS TO THE PREVIOUS FORECAST. && .AVIATION... VFR SKIES ARE EXPECTED THROUGH 12Z MONDAY WITH NO VISIBILITY RESTRICTIONS OR SIGNIFICANT WEATHER EXPECTED. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...SD SHORT TERM...DORN LONG TERM...MOHR AVIATION...HINTZ WEATHER.GOV/ABERDEEN sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 146 PM EDT SUN MAY 4 2008 .SHORT TERM...MSAS ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE OVER THE EASTERN CAROLINAS WITH A NORTHEAST TO SOUTHWEST ORIENTED TROUGH EXTENDING THROUGH THE PANHANDLE OF FLORIDA. NORTHERLY PUSH OF DRIER SURFACE AIR STILL RESIDES WELL WEST OF THE AREA OVER THE LOWER MISSISSIPPI VALLEY WITH MOISTURE POOLING AHEAD OF THIS FEATURE THROUGH THE ALABAMA AND GEORGIA BORDER. HOWEVER...AFTER EXAMINATION OF LATEST WATER VAPOR IMAGERY AND RUC UPPER LEVEL CHARTS...IT IS APPARENT THAT MOST ALL OF THE UPPER LEVEL SUPPORT HAS EXITED STAGE RIGHT. THIS IS STILL PRODUCING SOME SHOWER ACTIVITY OVER THE OUTER MOST COASTAL ZONES...BUT EVEN THIS SHOULD BE ON THE WANE THROUGH SUNSET. FOR THE REMAINDER OF THIS EVENING...WEST COAST SEABREEZE WILL REMAIN DOMINANT IN WESTERLY SYNOPTIC ENVIRONMENT ALLOWING FOR A LATE COLLISION ALONG THE FLORIDA ATLANTIC ZONES. GIVEN DEGREE OF DRY AIR ALOFT AN SUBSIDENCE...FEEL DEVELOPMENT WILL BE VERY UNLIKELY AND IF ANYTHING CAN FORM AT ALL...SHOULD BE ISOLATED AND IN THE FORM OF SHOWERS. THROUGH MON...AREA OF LOW PRESSURE REMAINS OVER THE AREA BUT BULK OF THE MOISTURE WILL BE ON THE EASTERN SIDE...AWAY FROM THE MAINLAND. WILL THEREFORE CARRY NIL POPS AND WITH A LATE DEVELOPING SEABREEZE...TEMPS WILL BE ALLOWED TO REACH THE MID TO UPPER 80S UNDER FULL SUN. LOW PUSHES EAST OF THE ARE BY TUE WITH WEAK HIGH PRESSURE BUILDING IN WEST OF THE AREA. DRY NORTHWEST FLOW ALOFT AND LIMITED SURFACE MOISTURE AS WELL WILL KEEP NIL POPS OVER THE AREA. A QUICKER DEVELOPING SEABREEZE IN SYNOPTIC NORTHEAST FLOW WILL RESULT IN COOLER MAX TEMPS ALONG THE COAST. SOME SLIGHT MODEL DISCREPANCIES CROP UP FOR WED AFTERNOON AS NAM12 IS MORE AGGRESSIVE IN BRINGING LOW LEVEL MOISTURE INTO THE AREA ON THE RETURN FLOW SIDE OF ATLANTIC HIGH PRESSURE. NAM12 IS OFTEN OVERDONE IN THESE LIMITED CONVERGENCE YET LIMITED MOISTURE SITUATIONS AND WILL SIDE WITH THE DRIER GFS FOR THIS CYCLE. .LONG TERM...NEXT SYSTEM AND ASSOCIATED UPPER LEVEL SUPPORT LOOKS TO REMAIN WELL NORTH OF THE REGION THROUGH WEEKS END WITH VERY LIMITED RAIN CHANCES IN STORE. CURRENT GRID SET HAS A VERY GOOD HANDLE ON THIS SCENARIO AND NO CHANGES ARE PLANNED. && .AVIATION...VFR CONDITIONS ARE FORECAST. THERE SHOULD BE ENOUGH BOUNDARY LAYER WINDS BEHIND SLOW MOVING FRONTAL BOUNDARY TONIGHT TO PRECLUDE FOG DEVELOPMENT. && .MARINE...NO HEADLINES UNTIL POSSIBLY LATE NEXT WEEK. A WEAK COLD FRONT WILL SLOWLY MOVE ACROSS THE AREA TONIGHT WITH HIGH PRESSURE SETTLING IN EARLY NEXT WEEK. THIS HIGH WILL DRIFT EAST LATE NEXT WEEK AND COUPLED WITH APPROACH OF NEXT FRONTAL SYSTEM WILL INCREASE WINDS ACROSS THE LOCAL WATERS...WITH POSSIBILITY OF SCEC/SCA HEADLINES. && .FIRE WEATHER...DRIER AIR WILL FILTER INTO THE AREA BEHIND THE FRONT WITH BASICALLY A DRY FORECAST THROUGH AT LEAST MID-WEEK. MONDAY... HAVE EXPANDED RED FLAG WARNING TO INCLUDE MOST NORTHEAST FLORIDA COUNTIES. TUESDAY...A FIRE WEATHER WATCH CONTINUES FOR LARGE PORTION OF INTERIOR NORTHEAST FLORIDA. && .PRELIMINARY POINT TEMPS/POPS... AMG 57 85 55 85 / 0 0 0 0 SSI 64 82 63 78 / 10 10 0 0 JAX 62 86 59 82 / 10 10 0 0 SGJ 64 84 63 80 / 10 0 0 0 GNV 59 88 56 87 / 0 0 0 0 OCF 60 87 55 87 / 0 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR ALACHUA-BAKER-BRADFORD-COLUMBIA-GILCHRIST-HAMILTON- MARION-SUWANNEE-UNION. FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR ALACHUA-BAKER-BRADFORD-COLUMBIA-GILCHRIST- HAMILTON-MARION-SUWANNEE-UNION. GA...NONE. AM...NONE. && $$ DEESE/ZAPPE/KEEGAN fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 346 PM EDT SUN MAY 4 2008 .DISCUSSION...LATEST RUC/UPPER AIR/SATELLITE ANALYSIS THIS AFTERNOON REVEALS UPPER LEVEL LOW CENTERED OVER NORTHWEST ONTARIO WITH A SHORTWAVE ROTATING AROUND THIS FEATURE INTO THE WESTERN GREAT LAKES. WITH MID LEVEL LAPSE RATES AROUND 6.5C/KM...CERTAINLY SOME VIGOROUS AC SEEN ON SATELLITE ACROSS NORTHERN WISCONSIN/WESTERN UP. THERE HAS BEEN AN ABUNDANCE OF REFLECTIVITIES ON KMQT AND KGRB RADARS THIS AFTERNOON ASSOCIATED WITH THIS MID CLOUD. NOT CERTAIN ANY PRECIPITATION IS REACHING THE GROUND...BUT IT CERTAINLY HAS THE APPEARANCE THAT THERE MAY BE SOME LIQUID REACHING THE GROUND. FORECAST CONCERNS FOR THIS EVENING AND TONIGHT REVOLVE AROUND PRECIPITATION CHANCES WITH THE PASSAGE OF THE SHORTWAVE/COLD FRONT TONIGHT...AND DETERMINING THE SOUTHWARD EXTENT OF THE MID LEVEL CLOUDS TONIGHT IMPACTING TEMPERATURES. TONIGHT...SHORTWAVE WILL CONTINUE ITS TRACK ACROSS THE NORTHERN GREAT LAKES. MOST OF THE MOISTURE ASSOCIATED WITH THIS SYSTEM IS IN THE MID LEVELS AS EVIDENT WITH CLOUD HEIGHTS AROUND 8-10 KFT. WITH THIS IN MIND...EXPECTING MAINLY LIGHT RAIN SHOWERS...BORDERING ON SPRINKLES FOR THE AREA IMPACTED TONIGHT. THE MAIN SHORTWAVE ENERGY WILL SWING THROUGH AREAS NORTH OF M-68 IN NORTHERN LOWER TONIGHT...SO WILL ONLY CARRY POPS IN THE FAR NORTH...TRIMMING POPS OUT OF AREAS SOUTH OF M-68. THE RAIN SHOWERS/SPRINKLES WILL ARRIVE SHORTLY AFTER 8 PM THIS EVENING...AND SHOULD EXIT THE AREA BY LATE TONIGHT. PREVIOUS SHIFTS HAD LIKELY POPS IN THE NORTH AND SEE NO REASON TO DOWNGRADE AT THIS POINT. IT WILL LIKELY BE A HIGH POP/LOW QPF EVENT THIS EVENING. CERTAINLY CANNOT RULE OUT A STRAY RUMBLE OF THUNDER TONIGHT WITH MID LEVEL LAPSE RATES AROUND 6.5C/KM...BUT GIVEN THERE HAS BEEN NO LIGHTNING DETECTED UPSTREAM...WE WILL BE HARD PRESSED TO SEE ANYTHING TONIGHT EITHER. FURTHER SOUTH...EXPECT PARTLY TO MOSTLY CLEAR SKIES TO REMAIN THROUGH MUCH OF THE NIGHT...PRODUCING ANOTHER CHILLY NIGHT WITH LOWS FALLING INTO THE 30S. LOWS WILL BE A BIT WARMER IN THE NORTH WITH THE CLOUD COVER TONIGHT. KAS LONG TERM...MONDAY...COLD FRONT WILL BE EXITING SOUTHEAST ZONES DURING THE MORNING HOURS AND GET HUNG UP ACROSS SOUTHERN LOWER MI. LOW LEVEL COLD ADVECTION INTO NORTHERN PORTIONS OF THE FORECAST AREA SETS UP A DECENT THERMAL GRADIENT FROM NORTH TO SOUTH DURING THE AFTERNOON...WITH DEEP MIXING EXPECTED ALONG/SOUTH OF M-55 WHICH SHOULD RESULT IN A MORE EXTENSIVE HIGH BASED CU FIELD. WOULDN`T BE SURPRISED TO SEE A FEW SHOWERS TRY TO POP ALONG THE OLD BOUNDARY TO THE SOUTH DURING THE AFTERNOON. OTHERWISE SOME MORNING CLOUDS WILL GIVE WAY TO MORE SUN BY AFTERNOON...WITH TEMPERATURES LIKELY STRUGGLING TO BREAK 50 ACROSS EASTERN UPPER...WHILE WARMING INTO THE 60S CLOSER TO SAGINAW BAY AND POINT SOUTH. LOW LEVEL WARM ADVECTION AND FRONTOGENETIC FORCING RAMP UP ACROSS NORTHERN WI/SOUTHWEST UPPER DURING THE AFTERNOON...BENEATH STEEPER MID LEVEL LAPSE RATES (6.5C/KM 700-500MB LAYER) ALONG WITH INCREASING MOISTURE CONVERGENCE ALONG NOSE OF 30KT LOW LEVEL JET. GUIDANCE HAS TRENDED A BIT FARTHER SOUTH WITH PRECIPITATION GENESIS REGION...AND THUS THE RESULTANT QPF WHICH ADVANCES INTO NORTHERN LOWER OVERNIGHT. WILL BUMP POPS UP A BIT ACROSS NORTHERN LOWER GIVEN THIS TREND. TUESDAY...MAY BE SOME LINGERING PRECIPITATION EARLY TUESDAY...BUT FOR THE MOST PART EXPECTING A DRYING TREND THROUGH THE DAY. SET UP FOR TUESDAY NIGHT IS PRETTY SIMILAR TO MONDAY NIGHT AS WARM ADVECTION CONTINUES OVER SURFACE BOUNDARY ACROSS MN/WI...WILL CARRY CHANCE POPS MOST AREAS EXCEPT FAR SOUTHEAST FOR NOW AND LET THE DETAILS (LOCATION/TIMING) WORK THEMSELVES OUT. EXTENDED FORECAST (WEDNESDAY THROUGH SUNDAY)...MIDWEEK PERIOD WILL START WITH A CONTINUED CHANCE FOR RAIN WEDNESDAY AS ACTIVITY THAT DEVELOPS TUESDAY NIGHT ADVANCES ACROSS THE AREA. WILL THEN LOOK AHEAD TO SHORT WAVE ENERGY CROSSING THE SOUTHERN PLAINS IN THE THURSDAY TIME FRAME. GUIDANCE HAS BEEN CONSISTENT IN SHOWING SOME WEAK SURFACE RIDGING POKING INTO THE STATE FROM THE NORTHWEST ON THURSDAY...SO SHOULD BE ABLE TO CONTINUE WITH A DRY FORECAST. SUBSEQUENT TRACK OF THIS WAVE ACROSS THE OHIO VALLEY STILL LOOKS TO BE FAR ENOUGH SOUTH TO AVOID IMPACTING NORTHERN MI. IF THIS SCENARIO HOLDS COULD BE LOOKING AT A COUPLE OF CHILLY NIGHTS DURING THE LATTER HALF OF THE WEEK. WILL SPLIT THE RAIN CHANCES FOR NEXT WEEKEND...KEEPING SATURDAY DRY AND CARRYING A CHANCE FOR SHOWERS SUNDAY. TEMPERATURES WILL LIKELY AVERAGE BELOW NORMAL THROUGH THE COMING WEEK AS A WHOLE. JPB && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ341-342- 344-345. LH...NONE. LS...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 402 PM CDT SUN MAY 4 2008 .DISCUSSION... WIND SHIFT WILL MOVE ACROSS THE AREA THIS EVE. IT IS MORE PROGRESSIVE THAN ANY MODEL BUT THE RUC...BUT WILL EVENTUALLY HANG UP IN SE NEB AND THEN REVERSE. LIGHT AND VBL WINDS TONIGHT WILL ALLOW DECENT COOLING. WARM ADVECTION RESUMES MONDAY WITH HIGHS APPROACHING 80. MID CLOUDS MAY INCREASE ENOUGH TO HOLD TEMPS BACK A FEW DEG. RICH LOW LEVEL MOISTURE IN RIO GRANDE VALLEY WILL RETURN THROUGH CENTRAL KS...AND MAY BE ENOUGH TO TRIGGER A FEW TSTMS IN SW COUNTIES BY LATE AFTN. THERE WILL BE A CHANCE MAINLY IN THE SOUTH MON NGT. SPC SEES A RISK OF SVR...AND WOULD NOT RULE OUT SOME ELEVATED HAIL PRODUCERS. HOWEVER...LOW LVL JET IS WEAK THIS FAR NORTH...AND UPPER DYNAMICS ARE VERY LIMITED. WENT SLGT CHC OF TSTMS ALL BUT FAR SOUTH. CONDITIONS FOR THUNDER NOT A LOT BETTER TUE. WEAK UPPER RIDGING CONTINUES. WARM MOIST AIR WILL BE PRESENT...BUT BOUNDARIES ARE LACKING. REDUCED DAYTIME POPS SOMEWHAT. PRECIP CHC INCREASES TUE NIGHT INTO WED. SOME STORMS DURING THIS PD COULD BE STRONG AND/OR PRODUCE HEAVY RAIN ESPECIALLY IN THE SOUTH. DURING THIS PD AN UPPER LOW...INITIALLY STRONG...KICKS NORTHEAST INTO KS. ACCEPTED HPC DISUCSSION DISCOUNTING NAM STRONGER NRN BRANCH SHORT WAVE AND SOMEWHAT FASTER FRONT. THIS LEAVES A FRONTAL BOUNDARY TO INTERACT WITH MOIST AIR TUE NIGHT IN THE NORTH...AND ALL DAY WED IN THE SOUTH. CUT GRAPHICAL HPC QPF THAT FOCUSES ON WED AFTN IN THE SOUTH DUE TO DRIER FORECASTS BY ALL NEIGHBORS. HOWEVER BELIEVE SOUTH HAS HEAVY RAIN POTENTIAL AS SFC BOUNDARY INTERACTS WITH UPPER SYSTEM AND MENTIONED THIS POSSIBILITY IN THE FCST. UPPER SYSTEM SHOULD PULL AWAY FROM THE AREA BY THU...LEAVING US A COUPLE OF DRY DAYS WITH MODERATE TEMPS. MODELS ARE NOT COHERENT ENOUGH TO SAY WHEN THE NEXT SGFNT CHC OF PRECIP WILL BE...BUT NEXT WEEKEND APPEARS TO BE BEST ESTIMATE. FOCUSED BEST POPS ON SAT NIGHT...BUT COULD WELL END UP BEING A DIFFERENT PD DUE TO HIGH UNCERTAINTY SO FAR OUT. WAVES APPEAR TO BE WEAKER IN QUASI ZONAL FLOW. THIS WOULD PREVENT MOISTURE FROM BEING PUSHED AS FAR SOUTH AS IT HAS SO FAR THIS SPRING... BUT ALSO MAKES TIMING MORE DIFFICULT. && .AVIATION... FOR TAF SITES KOMA...KLNK AND KOFK. VFR CONDITIONS THROUGH THE PERIOD WITH INCREASING LOW LEVEL MOISTURE APPROACHING FROM THE SOUTH AFT 12Z/05. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ POLLACK/FOBERT ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 335 PM CDT SUN MAY 4 2008 .SHORT TERM...THROUGH WEDNESDAY NIGHT SHORT TERM FORECAST HASN/T BECOME ANY MORE CLEAR SINCE YESTERDAY...IN FACT...IN MANY FACETS...CONFIDENCE HAS DIMINISHED WITH REGARDS TO MON-WED RAIN CHANCES THANKS TO SOME TRENDS IN THE NEW 04.12Z DATASETS. SPENT BULK OF THE TIME ON THE RAIN CHANCES MON AFTN/EVENING...AND TUES EVENING INTO WEDNESDAY. CURRENTLY...COMPACT PV ANOMALY /PER RUC 1.5 PV SURFACE TO 525MB/ NEAR LAKE OF THE WOODS /MN/ WITH ELONGATED SFC LOW/FRONTAL ZONE OUT AHEAD FROM ERN ND INTO THE UP OF MI. LOW LEVEL CONVERGENCE ZONE ON ERN PORTION OF THIS PRESSURE TROUGH CAUSING CUMULUS/ACCAS FIELD TO LOOK A LITTLE AGITATED...WITH KDLH 88-D HAVING PLENTY OF ELEVATED ECHO OVER NRN WISCONSIN. DRY SUBCLOUD LAYER ALLOWING MAINLY VIRGA...THOUGH A FEW SPRINKLES HAVE BEEN NOTED NORTH OF LOCAL FORECAST AREA. OTHERWISE...FLAT CUMULUS BASED AROUND 7KFT WITH DWPTS AROUND 30 MUCH OF FORECAST AREA AND BREEZY SWLY FLOW AHEAD OF AFOREMENTIONED TROUGH. LOW DEWPOINTS ALL THE WAY TO SRN TX WITH 04.12Z CNTL CONUS RAOBS NOT SHOWING CLIMATOLOGICALLY NORMAL PWATS UNTIL ONE GETS ALL THE WAY TO CORPUS CHRISTI /TX/. HENCE CLOUDS AT A MINIMUM MUCH OF CNTL CONUS. TONIGHT...EXPECT NRN MN PV ANOMALY TO SHIFT RAPIDLY SOUTHEAST...CIRCUMNAVIGATING THE PERSISTENT NEGATIVE ANOMALY OVER CNTL CANADA. SURFACE FRONT WILL BEGIN TO SLOW/WASH OUT AS IT BECOMES DETACHED FROM THE PARENT HEIGHT FALLS TURNING EAST. EXPECT EVENING SPRINKLES/SHOWERS TO MAINLY STAY NORTH/EAST OF FORECAST AREA. PLENTY OF CLEAR SKIES TONIGHT. MONDAY...YET ANOTHER WAVE...STRONGER IN THE 04.12Z DATA AND FURTHER SOUTH...SWINGS AROUND CANADA VORTEX. VERY SIMILAR SETUP TO TONIGHT...THOUGH FURTHER SOUTH TRACK AND INCREMENTALLY MORE BOUNDARY LAYER MOISTURE SHOULD ALLOW A LITTLE LARGER AREA OF -SHRA INTO NRN WISCONSIN WHICH MAY MAKE IT AS FAR SOUTH AS I-94 CORRIDOR. HAVE SEEN SIGNALS FOR OTHER MORE ISOLD SHRA OVER SWRN WISCONSIN WHERE LOCALLY STEEP LOW LEVEL LAPSE RATES WILL WORK WITH RELATIVELY HIGHER BOUNDARY LAYER THETA-E FOR A FEW UPDRAFTS. KEPT MONDAY POPS INTACT...AND REINTRODUCED EVENING POPS NORTH/EAST FOR PROGRESSION OF SHRA QUICKLY THROUGH THE NORTHWEST FLOW. SHOULD AGAIN SEE PLENTY OF HIGH BASED AFTERNOON CUMULUS GIVEN THE STEEP LAPSE RATES. SREF CHANCES FOR MEASURABLE HAVE BEEN STEADY IN THEIR DEPICTION OF THIS LIGHT/SCATTERED QPF. TUESDAY...MOST NOTABLE TREND IN 04.12Z DATASETS WAS TO SLOW EWRD FRONTAL PASSAGE FROM EVENING/PEAK INSTABILITY BACK TO VERY LATE TUES NIGHT OR EVEN WEDNESDAY MORNING. THIS IN RESPONSE TO LESS NRN STREAM /CANADIAN VORTEX/ INFLUENCE AND MORE RIDGING INTO CNTL CONUS DOWNSTREAM OF BAJA CUTOFF LOW. THUS...HAVE DOUBTS ABOUT SEVERE POTENTIAL ON TUES AFTN/EVE /PER CURRENT SWODY3/. RIGHT NOW...NOT SEEING ANY REAL FOCUS TO DRIVE CONVECTION. SEEMS BOUNDARY LAYER MOISTURE IN MODELS IS OVERDONE /PER CURRENT CNTL CONUS COMPARISONS/ AND THUS CAPE IS BEING MISREPRESENTED A BIT. MAY BE A WEAK WARM FRONTAL STRUCTURE ACROSS IOWA LIFTING NORTH BUT FLOW/CONVERGENCE INTO THIS BOUNDARY IS NOT ALL TOO IMPRESSIVE. 04.12Z WRF STILL SPOTTING QPF ALL OVER ON TUES AFTN/EVE BUT QUICKLY KILLING IT OFF SUGGESTING THIS MORE A FUNCTION OF STEEP LAPSE RATES/OVERDONE DEWPTS AND NOT FORCING FROM APPROACHING PLAINS SHORTWAVE ENERGY. WILL NEED TO BE WATCHED FURTHER...AND DID NOT TOUCH POPS GIVEN SIGNAL THAT BETTER CHANCES MAY RESIDE LATER IN THE NIGHT WHEN Q/G FORCING AND FRONTAL ZONE MOVE NEAR/THROUGH. IF CONVECTION CAN DEVELOP TUES AFTN/EVE...SEEMS SOUTH/WEST AREAS STAND BEST CHANCE OF SEEING THIS PCPN. WEDNESDAY...OTHER TREND IN 04.12Z DATA WAS /GIVEN MORE RIDGING INTO CNTL CONUS AND LESS NRN STREAM INFLUENCE/ A SHIFT NORTH WITH SFC CYCLONE AND HEAVY RAIN SHIELD ON WED/WED NIGHT IN THE CNTL CONUS. 04.12Z GFS NOT SUPPORTED IN ANY WAY AND LOOKS VERY RIDDLED WITH CONVECTIVE FEEDBACK...SO IGNORING IT/S SWATH OF 2-3 INCH RAINS ACROSS THE FORECAST AREA. SEEMS 04.12Z ECMWF/NAM ARE GOOD WAYS TO GO RIGHT NOW...WITH POST FRONTAL /ISENTROPIC LIFT/ INDUCED RAIN SHIELD TO HAVE BETTER CHANCES OF MOVING BACK INTO FORECAST AREA ON WED THAN PREVIOUSLY THOUGHT. SHIFTED POPS THIS WAY...BUT NOT IN EARNEST YET GIVEN NEW DEVELOPMENT HERE. STILL SEEMS PER 04.15Z SREF THAT MAIN HEAVY RAIN THREATS REMAIN ACROSS SRN IA/NRN MO/WRN IL...BUT THIS NWRD TREND NEEDS TO BE WATCHED GIVEN OUR HYDRO STATUS AND RIVERS RUNNING HIGH. .LONG TERM...THURSDAY THROUGH SUNDAY CONFIDENCE DECREASES RAPIDLY THROUGH THE EXTENDED PORTION OF THE FORECAST WITH DETAILS REGARDING PCPN POTENTIAL. SEEMS A PRETTY CLEAR SIGNAL...AND HAS FOR SEVERAL DAYS...THAT BELOW NORMAL TEMPERATURES /60S/ WILL CONTINUE TO DOMINATE AS BLOCKING ACROSS HIGHER LATITUDES MAINTAINS BELOW CLIMATOLOGY HEIGHTS/THICKNESSES OVER THE NRN CONUS. MID-WEEK CNTL PLAINS/MS VALLEY SYSTEM WILL BE PULLING EAST ON THURSDAY WITH LIKELY A COUPLE DRY DAYS IN SUBSIDENCE IN ITS WAKE. GETS A LITTLE MORE NEBULOUS INTO SAT/SUN AS DISAGREEMENT EXISTS ON HOW NWRN CONUS ENERGY WILL TRAVERSE THE NRN LATITUDES. MOST LONGER RANGE MODELS AGREE IN THESE HEIGHT FALLS...OR A PART OF THEM EJECTING ACROSS THE PLAINS/NRN CONUS FRI NIGHT/SAT DRIVING A FRONTAL ZONE EAST INTO AREA WITH RAIN CHANCES. THUS...MAINTAINED RAIN CHANCES FROM FRI NIGHT THROUGH SUN TO ACCOUNT FOR VARIED TIMING/ENERGY SEEN IN THE DETERMINISTIC GEM/ECMWF/GFS DATASETS. GENERALLY ADOPTED HPC IDEAS /MID RANGE RAIN CHANCES/ OVER THE WEEKEND UNTIL A STRONGER SIGNAL PRESENTS ITSELF. WENT DRY THURS AND FRI. && .AVIATION... THE WEAK 500 MB SHORT WAVE...THAT BROUGHT A BROKEN DECK OF HIGH CLOUDS TO THE FORECAST AREA EALIER TODAY...HAS MOVED SOUTHEAST INTO EASTERN WISCONSIN AND NORTHERN ILLINOIS. SUBSIDENCE BEHIND THIS SYSTEM HAS ALLOWED SOME CLEARING OF THE HIGH CLOUDS. THIS ALLOWED ENOUGH DIURNAL HEATING FOR A SCATTERED DECK OF HIGH BASE CUMULUS CLOUDS /6000-7000 FEET/. THESE CLOUDS SHOULD DISSIPATE WITH THE LOSS OF DIURNAL HEATING EARLY THIS EVENING. ANOTHER SERIES OF 500 MB SHORT WAVE TROUGHS WILL MOVE ACROSS NORTHERN MINNESOTA AND NORTHERN WISCONSIN LATE THIS AFTERNOON...EARLY MONDAY MORNING...AND LATE MONDAY AFTERNOON AND EVENING. MUCH OF THE FORCING WILL REMAIN NORTH AND EAST OF THE TAF SITES...SO WE SHOULD CONTINUE TO SEE VFR CONDITIONS THROUGH MONDAY. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT/LONG TERM...BINAU AVIATION...BOYNE wi