AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 1018 PM PDT WED APR 18 2007 .DISCUSSION... NORCAL IN BETWEEN WX SYSTEMS THIS EVENING AND SKIES HAVE CLEARED OVER MUCH OF THE AREA...AND ARE CLEARING OVER THE SIERNEV. ETA BUFKIT FORECAST SOUNDINGS INDICATE THE STRATO-CU DECK OVER THE SIERNEV WOULD ERODE AT 5000 FT THIS EVENING...BUT MID CLOUDS MAY SPREAD/DEVELOP OVER THE AREA AGAIN BY 12Z THU. THIS IS IN RESPONSE TO A STRONG VORT MAX DIGGING SEWD FROM THE GULF OF AK. CLOUDS ARE ENHANCING AHEAD OF THIS VORT MAX ALONG WARM FRONT JUST OFF THE N COAST. MODELS...INCLUDING THE RUC...ARE INDICATING INITIAL SHORT WAVE ENERGY AHEAD OF THE MAIN VORT MAX...AND MID LEVEL MOISTURE WILL BE MOVING INTO/INCREASING OVER OUR NRN ZONES BY 12Z THU. STRONG 150 KT JET ON THE BACKSIDE OF THE UPPER LOW VCNTY 45N/135W SHOULD DIG THE SYSTEM SEWD AND PARALLEL TO THE CA COAST THRU FRI. STRONGEST LARGE SCALE ASCENT OR SYNOPTIC FORCING IS FORECAST REMAIN JUST OFF THE CA COAST...WITH THE INTERIOR OF NORCAL ON THE ERN/SRN FRINGE OF THE Q-VECTOR FORCING FROM AFT 18Z THU THRU 12 FRI. MOISTURE WILL BE LACKING WITH THIS SYSTEM AS THE TPW PLUME OFF THE COAST HAS BEEN WORKED OVER. NAM INSTABILITY PROGS INDICATE BEST INSTABILITY WILL REMAIN OFF THE COAST THU AFTN...AND THEN WILL MOVE INLAND FRI AFTN BUT BE CONFINED TO AREAS JUST N AND E OF OUR FORECAST AREA. ALL FACTORS CONSIDERED...THIS SYSTEM DOES NOT LOOK LIKE IT WILL BE A SIGNIFICANT QPF EVENT FOR THE INTERIOR OF NORCAL...WITH COASTAL SECTIONS...AND POSSIBLY UPSLOPE CONDITIONS FROM THE CYCLONIC FLOW OVER THE INTERIOR AUGMENTING QPFS ON THE E SIDE OF THE COASTAL RANGE...RECEIVING THE BULK OF THE QPF. NORCAL WILL BE IN BETWEEN WX SYSTEMS AGAIN FOR THE FIRST HALF OF THE DAY ON SAT AS SHORT WAVE RIDGING OCCURS OVER NORCAL AHEAD OF THE NEXT GOA TROF. THIS SYSTEM WILL ACT AS A KICKER FOR THE AFOREMENTIONED UPPER LOW...MOVING IT INLAND OVER EXTREME SOCAL/NRN BAJA AND THEN EJECTING IT NEWD INTO THE PLAINS STATES ON SUN. THE NEXT GOA TROF IS SCHEDULED TO DIG INTO NORCAL WITH A CHANCE OF MORE SHOWERS SAT NITE/SUN. THIS SYSTEM LOOKS TO HAVE A BETTER SUPPLY OF MOISTURE AS A TPW PLUME OF 1.30 INCHES IS FORECAST TO BECOME ORIENTED PERPENDICULAR TO THE CA COAST LATE SAT...AND MAY BE A BETTER PRECIP PRODUCER THAN WHAT WE EXPECT FROM THE THU/FRI SYSTEM. IMPROVING WX EXPECTED MON AS THE WEEKEND SYSTEM DIGS AND MOVES ACROSS THE DESERT SW. DRIER WX EXPECTED THEN FOR THE REST OF NEXT WEEK. JHM && .AVIATION... VFR CONDITIONS OVER RTES AS SKIES HAVE CLEARED OVER INTERIOR NORCAL EXCEPT FOR SIERNEV CREST WHERE SOME MVFR CIGS MAY LINGER THRU 08Z. LOOK FOR INCREASING CLOUDS FROM W TO E OVER RTES OVERNITE AS WARM FRONT MOVES INLAND AHEAD OF NEXT GULF OF AK UPPER TROF AND CD FNT. THIS SYSTEM IS FORECAST TO DIG AND PARALLEL THE COAST THRU FRI...AND THE INTERIOR OF NORCAL WILL REMAIN ON THE E OR CYCLONIC SIDE OF THE UPPER LOW. VFR CONDITIONS EXPECTED TO DETERIORATE TO MVFR CIGS/-SHRA AFT 00Z FRI IN THE CENTRAL VLY...AND TO IFR CIGS AND SHRA/SHSN OVER INTERIOR MTNS AFT 00Z FRI. SHOWERS EXPECTED TO MOVE NWWD OVER RTES. && .STO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 230 PM EDT WED APR 18 2007 .SYNOPSIS... 18Z WATER VAPOR AND H4 RUC ANALYSIS SHOWS A RATHER COMPLEX UPPER LEVEL PATTERN ACROSS THE CONUS. THREE DISTINCT WEATHER MAKERS ARE SEEN ACROSS THE EAST WITH THE LARGE CLOSED UPPER LOW CONTINUING TO SPIN JUST OFF THE NORTHEAST COAST...ANOTHER WEAKER CLOSED LOW DROPPING SOUTH FROM THE GREAT LAKES INTO THE OHIO VALLEY AND YET A THIRD SHORTWAVE MOVING THROUGH THE SOUTHERN STREAM ALONG THE EASTERN GULF COAST. AMPLIFIED RIDGING IS FOUND FURTHER UPSTREAM THROUGH THE CENTRAL PART OF THE COUNTRY WITH A DEEP TROUGH EVEN FURTHER UPSTREAM ALONG THE PACIFIC COAST AND THROUGH THE INTERMOUNTAIN WEST. AT THE SURFACE...VERY WEAK LOW PRESSURE CONTINUES TO PUSH OVER AND JUST TO OUR NORTH ALTHOUGH WITH SUCH A WEAK GRADIENT IT IS DIFFICULT TO DETERMINE AN EXACT CENTER. PLENTY OF CLOUDCOVER CONTINUES ACROSS THE FORECAST AREA AT THIS TIME ALTHOUGH THERE HAVE BEEN PERIODIC BREAKS OF SUN HELPING TO BOOST TEMPERATURES INTO THE UPPER 60S TO MIDDLE 70S MOST LOCATIONS. VERY IMPRESSIVE AREA OF Q-G FORCING PER LATEST GFS HAS BEEN PRODUCING AN AREA OF MORE STEADY SHOWERS ACROSS THE WESTERN HALF OF THE CWA THROUGH THE EARLY AFTERNOON. SHOWERS ARE NOW MOVING INTO AN AREA OF MUCH DRIER LOW LEVEL AIR AND BEGINNING TO SEE A DECREASE IN COVERAGE ON REGIONAL RADARS AS A RESULT. HOWEVER...THE Q-G FORCING REALLY DOES NOT DIMINISH ALL THAT MUCH AS IT PUSHES EAST INTO THE EARLY EVENING. FOR THAT REASON IF THE LOWER LEVELS CAN MOISTEN JUST A BIT AS FORECAST SOUNDINGS CONTINUE TO SHOW...THEN A FEW SCATTERED SHOWERS OR SPRINKLES WILL STILL BE POSSIBLE FOR THE EASTERN HALF OF THE AREA AND WILL KEEP A LOW CHANCE 30 POP IN FOR MUCH OF THE BIG BEND AND SOUTH-CENTRAL GA THROUGH THE REST OF THE AFTERNOON. QPF AMOUNTS FOR THE REST OF THE DAY SHOULD BE ON THE VERY LIGHT SIDE WITH GENERALLY A FEW HUNDREDTHS OF AN INCH (IF THAT) IN MOST LOCATIONS. && .SHORT TERM (TONIGHT THROUGH SATURDAY)... UPPER LEVEL SHORTWAVE AND ASSOCIATED WEAK SURFACE LOW PULLS EAST OF THE FORECAST AREA THIS EVENING WITH A TRAILING WEAK COLD FRONT SLIDING SOUTH INTO THE COASTAL WATERS. LARGE SCALE Q-G FORCING ASSOCIATED WITH CURRENT SHOWERS ACROSS THE CWA IS PROGGED TO WEAKEN AND EXIT WITH THE SHORTWAVE BY AROUND SUNSET THIS EVENING. WILL LIKELY HOLD IN A SLIGHT CHANCE POP FOR THE FAR EASTERN BIG BEND/SOUTH-CENTRAL GA INTO THE LATE EVENING BUT WILL END ALL MENTION OF SHOWERS AFTER THAT. SKIES WILL BECOME PARTLY CLOUDY THROUGH THE REST OF THE NIGHT WITH A LIGHT NORTHERLY WIND DEVELOPING BEHIND THE WEAK FRONT. LOW TEMPERATURES WILL FALL BELOW AVERAGE WITH THE NORTHERLY FLOW REACHING THE UPPER 40S TO NEAR 50 FOR MOST LOCATIONS AWAY FROM THE SHORELINE. THURSDAY LOOKS TO BE A FAIR AND PLEASANT DAY AT THIS TIME WITH AFTERNOON HIGH TEMPERATURES RUNNING FORM THE MIDDLE 70S FAR NORTH TO AROUND 80 FOR THE SOUTH. HIGH PRESSURE TO THE NORTHWEST WILL TRY AND NOSE INTO THE AREA WITH A LIGHT NORTHWEST TO WEST WIND UNDER PARTLY TO MOSTLY SUNNY SKIES. WILL BE WATCHING A POTENT SHORTWAVE DROPPING SOUTH FROM THE TENNESSEE VALLEY TO THE CAROLINA AND GEORGIA COASTLINE DURING THE AFTERNOON AND EVENING HOURS. WEAK LOW PRESSURE ASSOCIATED WITH THIS MID-LEVEL SHORTWAVE WILL FOLLOW A SIMILAR PATH AND IS PROGGED TO EXIT THE GA/SC COASTLINE AROUND 00Z THURSDAY. AT THIS TIME DYNAMICS FOR LIFT ASSOCIATED WITH THESE FEATURES ARE EXPECTED TO STAY FAR ENOUGH NORTH AND EAST OF THE FORECAST AREA TO PREVENT ANY SHOWER ACTIVITY FROM REACHING US. WOULD EXPECT ONLY AN INCREASE IN CLOUDS ACROSS SOUTH-CENTRAL GA DURING THE AFTERNOON AND EVENING. A RE-ENFORCING COLD FRONT DROPPING SOUTH WITH THE WEAK LOW LOOKS TO CROSS THE CWA DURING THURSDAY EVENING THEN DROP INTO THE COASTAL WATERS DURING THE NIGHT. SURFACE HIGH PRESSURE CENTERED WELL TO OUR NORTH NOSES INTO THE REGION BEHIND THIS COLD FRONT FOR FRIDAY AND SHOULD REMAIN IN CONTROL OF THE AREA THROUGH THE DAY ON SATURDAY. DURING THURSDAY NIGHT AND FRIDAY THE MID-LEVEL ENERGY MENTIONED ABOVE IS EXPECTED TO PHASE WITH ANOTHER PIECE OF ENERGY ROUNDING THE BACKSIDE OF THE CLOSED LOW OFF NEW ENGLAND. THIS WILL RESULT IN A FAIRLY SIGNIFICANT TROUGH OFF THE EAST COAST DURING FRIDAY AND FRIDAY NIGHT. IT IS POSSIBLE THAT A WEAK DISTURBANCE OR TWO ROTATING AROUND THE BACKSIDE OF THIS TROUGH COULD BRING A PERIOD OR TWO OF HIGH CLOUDS TO THE EAST HALF OF THE CWA ON FRIDAY...HOWEVER THE ONLY EFFECT WOULD BE TO DIM THE SUN FROM TIME TO TIME. ALSO A MID-LEVEL COOL POCKET ASSOCIATED WITH THE UPPER TROUGH SHOULD MOVE OVERHEAD DURING FRIDAY AFTERNOON AND SHOULD HELP KEEP TEMPERATURES A BIT BELOW NORMAL. RAN TEMPERATURES A BIT CLOSER TO THE COOLER MAV GUIDANCE FOR THE REST OF THE SHORT TERM. THE TROUGH TRIES TO WEAKENS AND PULL AWAY FRIDAY NIGHT INTO SATURDAY...HOWEVER GLOBAL MODELS ARE ADVERTISING THAT A PIECE WILL HANG BACK OVER THE SOUTHEAST INTO THE FIRST HALF OF SATURDAY. CURRENT GRIDS CONTINUE THE SLIGHTLY BELOW NORMAL TEMPS FOR MUCH OF THE AREA AND DO NOT ANTICIPATE MAJOR CHANGES NEEDED FOR THE WEEKEND GRIDS. THEREAFTER LARGE SCALE RIDGING SEEN OVER THE MID SECTION OF THE COUNTY WILL BEGIN BUILDING INTO THE SOUTHEAST U.S. WITH FAIR WEATHER AND MODERATING TEMPERATURES. && .LONG TERM (SATURDAY NIGHT THROUGH TUESDAY)... RATHER BENIGN WEATHER PATTERN FOR MUCH OF THE EXTENDED ON TAP. BOTH THE 18/00Z GFS AND 18/00Z EURO AGREE THAT DEEP LAYER RIDGING WILL BUILD OVER THE REGION THROUGH MUCH OF THE WEEKEND BEFORE GRADUALLY SHIFTING OFF THE US EAST COAST. THE NET RESULT OF THIS WILL ONLY BE TO GIVE US TEMPS SLIGHTLY ABOVE CLIMO IN THE LOW TO MID 80S. BY MONDAY...THE SURFACE RIDGE AXIS SHIFTS OFF THE EAST COAST GIVING US SOUTHERLY FLOW AND ALLOWING US TO MOISTEN UP. THE UPPER RIDGE OVER THE EASTERN CONUS BEGINS TO FLATTEN OUT AS DEEP TROF ENTERS THE WEST COAST. DESPITE THE MOIST SOUTHERLY FLOW IT LOOKS TO REMAIN DRY UNTIL WEDNESDAY WHEN A FEW AFTERNOON SHOWERS WILL BE POSSIBLE. THE APPROACHING SYSTEM THAT ENTERED THE WEST COAST ON MONDAY WILL INCREASE OUR RAIN CHANCES BY THURSDAY...BUT THIS FAR OUT IT IS ANYONE`S GUESS ON HOW STRONG OR WEAK THIS SYSTEM WILL BE. NOT SURPRISINGLY...THERE ARE ALREADY RUN TO RUN CONSISTENCY ISSUES BETWEEN THE 17/18Z GFS AND 18/00Z GFS. && .MARINE... WEAK LOW PRESSURE PASSES EAST OF THE FORECAST AREA THIS EVENING WITH A WEAK TRAILING COLD FRONT SAGGING SOUTH THROUGH THE WATERS. HAVE SEEN WINDS COME UP TO CAUTION CRITERIA OVER THE OFFSHORE LEGS THIS PAST AFTERNOON...BUT GUIDANCE SHOWING THIS TO BE A SHORT TERM RISE AND SHOULD SEE THESE WINDS SETTLE BACK DOWN DURING THE EVENING. BEHIND TONIGHTS FRONT WILL SEE GENERAL NORTHWEST TO NORTH FLOW THROUGH THURSDAY EVENING AS WEAK HIGH PRESSURE NOSES IN FROM THE NORTH. A RE-ENFORCING COLD FRONT THURSDAY NIGHT WILL BRINGS WINDS UP ONCE AGAIN FROM THE NORTH BUT SHOULD STAY JUST BELOW CAUTION CRITERIA AS HIGH PRESSURE ESTABLISHES ITSELF OVER THE WATERS INTO THE WEEKEND. A TIGHTENING GRADIENT FROM THE NORTHEAST FRIDAY NIGHT AND EARLY SATURDAY MAY BRING ANOTHER ROUND OF NEAR CAUTION LEVEL CRITERIA TO THE WATERS. && .AVIATION... THE LARGE BATCH OF RAIN FROM THE UPPER LEVEL LOW CONTINUES TO HOLD TOGETHER FAIRLY WELL AS IT HEADS EASTWARD THROUGH THE REGION. PFN BRIEFLY DROPPED TO IFR VIS IN A HEAVIER SHOWER...WHILE DHN REACHED MVFR LEVELS. EXPECT THE EASTERN 3 TAF SITES TO HAVE A SHORT PERIOD OF MVFR VIS WHEN THE RAIN ARRIVES...FOLLOWED BY CLEARING THIS AFTERNOON. OVERNIGHT...TLH AND VLD MAY HAVE SOME MVFR FOG BEFORE SUNRISE...BUT DHN...ABY...AND PFN ARE EXPECTED TO REMAIN VFR THROUGH THE NIGHT. && .FIRE WEATHER... ALTHOUGH CONDITIONS ARE CLOSE...DURATIONS OF RELATIVE HUMIDITY BELOW 35 PERCENT ACROSS THE BIG BEND DO NOT LOOK TO REACH CRITICAL DURATIONS THIS AFTERNOON AND THE RED FLAG WARNING HAS BEEN CANCELLED. BEHIND A WEAK COLD FRONT TONIGHT...DRIER AIR WILL ONCE AGAIN MOVE BACK INTO THE AREA AND THE FIRE WX WATCH FOR THURSDAY AFTERNOON ACROSS THE EASTERN FLORIDA PANHANDLE AND BIG BEND HAS BEEN UPGRADED TO A RED FLAG WARNING FOR EXTENDED DURATIONS OF CRITICAL RH. CONTINUED DRY AIR BEHIND A RE-ENFORCING COLD FRONT ON FRIDAY WILL BRING POSSIBLE CRITICAL DURATIONS OF RH BELOW 35 PERCENT ONCE AGAIN TO OUR FLORIDA ZONES AND A FIRE WX WATCH HAS BEEN ISSUED FOR THE AFTERNOON AND EARLY EVENING. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 50 80 50 78 50 / 10 0 0 0 0 PANAMA CITY 54 78 54 76 55 / 05 0 0 0 0 DOTHAN 48 78 51 77 50 / 05 0 0 0 0 ALBANY 47 78 50 76 49 / 10 0 10 0 0 VALDOSTA 50 78 50 76 49 / 10 0 10 0 0 CROSS CITY 53 81 51 77 50 / 15 0 10 0 10 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING FROM 1 PM EDT /12 PM CDT/ TO 8 PM EDT /7 PM CDT/ THURSDAY FOR THE FOLLOWING ZONES: BAY...CALHOUN... DIXIE...FRANKLIN...GADSDEN...GULF...HOLMES...INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE...LEON...LIBERTY... MADISON...TAYLOR...WAKULLA...WASHINGTON. FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY 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. && $$ AVIATION/FIRE WX...GOULD LONG TERM...GODSEY PUBLIC/MARINE....MROCZKA fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 910 AM EDT WED APR 18 2007 .UPDATE... UPPER LEVEL SHORTWAVE ACROSS THE CENTRAL GULF COAST CONTINUES TO OPEN AND SHEAR OUT AS IT MOVES EAST TOWARD OUR FORECAST AREA THIS AFTERNOON. SCATTERED TO NUMEROUS ECHOES ON REGIONAL RADARS ARE ALMOST ENTIRELY ALOFT THIS MORNING ACROSS OUR AREA. 12Z KTLH SOUNDING SHOWS US WHY WITH A VERY SIGNIFICANT DRY LEVEL BELOW ABOUT 550MB. DEWPOINT DEPRESSIONS WITHIN THIS LAYER REACH 30C ENSURING THAT ANY HYDROMETEORS FALLING INTO THE LAYER FROM ABOVE HAVE VERY LITTLE CHANCE OF REACHING THE SURFACE. FURTHER TO THE WEST OVER INTO SOUTHERN AL/MS WE DO SEE A MORE ORGANIZED AREA OF RAINFALL MORE IN PROXIMITY TO THE MID-LEVEL SHORTWAVE. THE STRONGER DYNAMICS FOR LIFT IN THIS AREA HAVE ALLOWED THE LOWER LEVELS TO MOISTEN AND QPF IS REACHING THE SURFACE. WITH TIME WE DO EXPECT THE LOW LEVELS ACROSS OUR AREA WILL MOISTEN ALLOWING SOME QPF TO REACH THE SURFACE... HOWEVER ALSO EXPECT THE UPPER LEVEL DYNAMICS TO WEAKEN WITH TIME. WITH THIS IN MIND...THE AREA OF RAINFALL SHOULD BECOME LESS IMPRESSIVE INTO THE EARLY AFTERNOON AND CURRENT FORECAST POPS LOOK GENERALLY O.K. FOR THE TIME BEING. SHOWERS REACHING THE GROUND FROM THE LATE MORNING INTO THE AFTERNOON SHOULD GENERALLY BE OF THE LIGHT AND WIDELY SCATTERED VARIETY. ALSO...AS MENTIONED IN THE PREVIOUS FORECAST...A RUMBLE OF THUNDER IS POSSIBLE ACROSS THE FLORIDA PANHANDLE ZONES INTO THE EARLY AFTERNOON...HOWEVER ANY THUNDERSTORMS WILL REMAIN EXTREMELY ISOLATED. QPF AMOUNTS (IF ANY)...STILL LOOK TO BE QUITE LOW WITH GENERALLY AROUND ONE TENTH OF AN INCH OR LESS. AREAS MORE LIKELY TO SEE MEASURABLE RAINFALL WILL BE IN THE WESTERN HALF OF THE CWA WHERE LOW LEVEL DRY AIR WILL BE FASTEST TO ERODE. MID LEVEL SHORTWAVE AND ASSOCIATED WEAK SURFACE LOW PASS OVER AND EAST OF THE FORECAST AREA LATE THIS AFTERNOON INTO THE EARLY EVENING. ANY LEFTOVER SHOWERS OR SPRINKLES SHOULD ALSO EXIT TO THE SOUTH AND EAST BY AROUND SUNSET. PARTIAL CLEARING AND SURFACE HIGH PRESSURE THEN NOSES IN FROM THE WEST AND NORTHWEST FOR THE OVERNIGHT HOURS. && .MARINE... WIND RUNNING GENERALLY OUT OF THE NORTHWEST 5 TO 10 KNOTS THIS MORNING WITH 1 TO 2 FOOT SEAS. DO EXPECT WINDS TO COME AROUND TO A MORE WESTERLY DIRECTION AND INCREASE INTO THE 10 TO 15 KNOT RANGE WITH TIME TODAY AND LATEST RUC IS IN AGREEMENT. && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THE MORNING HOURS AS ANY PRECIPITATION WILL BE LIGHT AND WILL FALL FROM MID LEVEL CIGS. THIS AFTERNOON...LOWERING CIGS MAY REACH MVFR LEVELS FOR A TIME...AND VIS MAY LOWER TO MVFR IN LOCATIONS THAT RECEIVE HEAVIER RAINFALL WHICH IS DEVELOPING OFF TO THE WEST. && .FIRE WEATHER... MONITORING THE RED FLAG WARNING VERY CLOSELY ACROSS THE FLORIDA BIG BEND FOR THIS AFTERNOON. IF TEMPERATURES STRUGGLE INTO THE EARLY AFTERNOON UNTIL THE ABUNDANT CLOUD COVER THAN THE WARNING MAY NEED TO BE CANCELLED. && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR THE FOLLOWING ZONES: DIXIE...GADSDEN... JEFFERSON...LAFAYETTE...LEON...MADISON...TAYLOR...WAKULLA. FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY 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. && $$ MROCZKA/GOULD fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 749 PM EDT THU APR 19 2007 .SYNOPSIS... LOW PRESSURE WILL MOVE EASTWARD AND THROUGH THE FORECAST AREA THIS EVENING. THE LOW WILL MOVE OFF THE COAST LATE TONIGHT. THE PRESSURE RIDGE EXTENDING THROUGH THE MISSISSIPPI RIVER VALLEY TONIGHT WILL BE OVER THE FORECAST AREA SATURDAY. && .NEAR TERM /UNTIL MIDNIGHT TONIGHT/... AREA OF LOW PRESSURE WILL MOVE THROUGH THE REGION TONIGHT...SPREADING SHOWERS AND THUNDERSTORMS INTO THE AREA. && .SHORT TERM /MIDNIGHT TONIGHT THROUGH SATURDAY/... THE MAIN FORECAST PROBLEM IS THE SEVERE WEATHER THREAT LATE THIS AFTERNOON AND EVENING. THE STRONG MID-LEVEL SHORTWAVE TROUGH WITH H5 TEMPERATURES NEAR -23 SHOULD BE DROPPING SOUTHWARD AND INTO THE FORECAST AREA THIS EVENING. INSTABILITY ASSOCIATED WITH THIS FEATURE PLUS LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY IN THE SOUTH PART OF THE AREA PLUS DIFFERENCE HEATING ASSOCIATED WITH CLOUDY AND SUNNY AREAS FARTHER NORTH SUPPORTS THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AND EVENING. SHEAR DOES NOT APPEAR PARTICULARLY STRONG WITH H85 WIND NEAR 20 KNOTS. BELIEVE THE MAIN THREAT IS DAMAGING HAIL. WEB-BULB ZERO HEIGHTS AND STRONG INSTABILITY ALOFT FAVOR LARGE HAIL. THE RUC...NAM...AND GFS FORECAST OF CROSS TOTALS IN THE MID TO UPPER 20S APPEARS REASONABLE BASED ON THE COLD H5 TEMPERATURES UPSTREAM. THE THREAT SHOULD END LATE TONIGHT AS THE H5 COLD POOL SHIFTS EASTWARD AND DIURNAL COOLING OCCURS. DRY RIDGING SHOULD BE IN CONTROL FRIDAY AND SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE LATEST GFS SHOWS RIDGING CONTINUING SUNDAY THROUGH TUESDAY WITH A FRONT EXTENDING THROUGH THE REGION WEDNESDAY AND THURSDAY. THERE APPEARS TO BE LITTLE UPPER-LEVEL LIFT ASSOCIATED WITH THE FRONT AND THE GFS ENSEMBLE MEAN POPS ARE LOW. PLAN TO FORECAST JUST SLIGHT CHANCE POPS. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... UPPER LOW WILL MOVE OVER AREA TONIGHT. POSSIBILITY OF THUNDERSTORMS TONIGHT. LOW FREEZING LEVEL AND VERY COLD AIR ALOFT WILL MAKE SMALL HAIL AAND WINSD A DISTINCT POSSIBILITY WITH THE THUNDERSTORMS. THROUGH 04Z CONDITIONS GENERALLY VFR EXCEPT IN SHOWERS AND THUNDERSTORMS WHERE VSBYS AROUND 4SM WILL RESULT IN MVFR CONDITIONS. AFTER 03Z BEHIND COLD FRONT THERE WILL BE STRATUS IN THE 3000 FT AGL RANGE RESULTING IN MVFR CIGS ALL TERMINALS. AFTER 12Z ON FRIDAY THE SKYS WILL BEGIN TO BREAK AND CONDITIONS WILL RETURN TO VFR. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 126 PM EDT THU APR 19 2007 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE APPROACHING FROM THE GREAT LAKES REGION WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. HIGH PRESSURE BUILDING FROM THE NORTH WILL PROVIDE DRY CONDITIONS FRIDAY THROUGH SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... THE MAIN FORECAST PROBLEM IS THE SEVERE WEATHER THREAT LATE THIS AFTERNOON AND EVENING. THE STRONG MID-LEVEL SHORTWAVE TROUGH WITH H5 TEMPERATURES NEAR -23 SHOULD BE DROPPING SOUTHWARD AND INTO THE FORECAST AREA THIS EVENING. INSTABILITY ASSOCIATED WITH THIS FEATURE PLUS LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY IN THE SOUTH PART OF THE AREA PLUS DIFFERENCE HEATING ASSOCIATED WITH CLOUDY AND SUNNY AREAS FARTHER NORTH SUPPORTS THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AND EVENING. SHEAR DOES NOT APPEAR PARTICULARLY STRONG WITH H85 WIND NEAR 20 KNOTS. BELIEVE THE MAIN THREAT IS DAMAGING HAIL. WEB-BULB ZERO HEIGHTS AND STRONG INSTABILITY ALOFT FAVOR LARGE HAIL. THE RUC...NAM...AND GFS FORECAST OF CROSS TOTALS IN THE MID TO UPPER 20S APPEARS REASONABLE BASED ON THE COLD H5 TEMPERATURES UPSTREAM. THE THREAT SHOULD END LATE TONIGHT AND THE H5 COLD POOL SHIFTS EASTWARD AND DIURNAL COOLING OCCURS. DRY RIDGING SHOULD BE IN CONTROL FRIDAY AND SATURDAY. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... CLOUDS LINGERING OVERNIGHT AND SOME WIND ESPECIALLY BEFORE MIDNIGHT PREFER WARMER GUIDANCE MINIMUM TEMPERATURES...DECREASING CLOUDS BY MID DAY FRIDAY AS HIGH PRESSURE BUILDS IN FROM THE NORTH. WARMING TREND DEVELOPS SATURDAY AS UPPER RIDGE BUILDS EAST FROM THE PLAINS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... UPPER RIDGE BUILDING EAST OVER THE WEEKEND...SO WARMING TREND EXPECTED. DRY PERIOD EXPECTED. NO CHANGES TO PREVIOUS FORECAST. && .AVIATION /18Z THURSDAY THROUGH MONDAY/... UPPER LOW WILL MOVE OVER AREA LATE THIS AFTERNOON AND EARLY THIS EVENING. THE PROBABILITY OF THUNDERSHOWERS WITH THIS FEATURE IS AROUND 60 PERCENT AT CAE...CUB...AND OGB AND AROUND 40 PERCENT AT AGS AND DNL. THUS WILL HAVE TEMPO FOR THUNDERSTORMS AT CAE...OGB..AND CUB BETWEEN 21Z AND 01Z. LOW FREEZING LEVEL AND VERY COLD AIR ALOFT WILL MAKE HAIL A DISTINCT POSSIBILITY WITH THE THUNDERSTORMS. PROBABILITY OF SHOWERS OR THUNDERSTORMS AT AGS AND DNL WILL BE JUST BELOW 50 PERCENT SO WILL ONLY PUT VCSH IN TAF. THROUGH 04Z CONDITIONS GENERALLY VFR EXCEPT IN SHOWERS AND THUNDERSTORMS WHERE VSBYS AROUND 4SM WILL RESULT IN MVFR CONDITIONS. AFTER 04Z BEHIND COLD FRONT THERE WILL BE STRATUS IN THE 1000 FT TO 2000 FT AGL RANGE RESULTING IN MVFR CIGS ALL TERMINALS. AFTER 12Z ON FRIDAY THE SKYS WILL BEGIN TO BREAK AND CONDITIONS WILL RETURN TO VFR. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 440 AM EDT THU APR 19 2007 .DISCUSSION... MAIN FCST CONCERNS ARE CLOUDS/TEMPS ALONG WITH SHRA/TSRA CHANCES THIS WEEKEND. WV IMAGERY AND RUC ANALYSIS INDICATED AN OMEGA PATTERN ACROSS NOAM WITH A MID/UPPER LEVEL TROF FROM THE PAC NW INTO THE ROCKIES...A RDG FROM HUDSON BAY AND NRN ONTARIO THROUGH THE PLAINS....AND A LOW OVER INDIANA. THIS LEFT A WEAK ERLY FLOW ACROSS UPPER MI. AT THE SFC...WEAK NE FLOW ALSO PREVAILED SOUTH A LARGE RIDGE FROM NRN CANADA THROUGH NRN ONTARIO INTO QUEBEC. IR LOOP SHOWED CLOUDS OVER UPPER MI HAD THINNED OUT LEAVING PATCHY MID CLOUDS MAINLY OVER THE ERN CWA. TODAY...THE RUC/NAM/GFS ARE IN GOOD AGREEMENT IN PUSHING LINGERING 850-700 MB MOISTURE EASTWARD OUT OF UPPER MI TODAY. SINCE THE CLOUDS WERE ALREADY PATCHY...EXPECT PLENTY OF SUNSHINE WITH MIXING TO AROUND 850 MB (TEMPS NEAR 3C) WILL HELP TEMPS CLIMB TO AROUND 60 INLAND. WEAK ENE WINDS OFF OF LAKE SUPERIOR WILL KEEP READINGS CLOSER TO 50F NEAR THE SHORE. TONIGHT AND FRI...GOOD RADIATIONAL COOLING CONDITIONS WITH SFC RIDGE AXIS THROUGH THE AREA SHOULD ALLOW TEMPS TO FALL OFF INTO THE UPPER 20S INLAND OVER MUCH OF THE AREA. WEAK DOWNSLOPE SE FLOW OVER THE WEST WILL KEEP MIN READINGS A BIT HIGHER. A SHRTWV EMERGING FROM THE NRN PLAINS WILL HELP FLATTEN THE RDG BUT WILL REMAIN FAR ENOUGH TO THE WEST SO THAT ONLY DISSIPATING WAA CLOUDS AHEAD OF THIS FEATURE BRUSH THE WRN CWA. OTHERWISE...WEAK LOW LVL WAA AND SUNSHINE WILL PREVAIL WITH TEMPS WELL INTO THE 60S INLAND. SAT INTO SUN...ALTHOUGH THE MDLS KEEP MID LEVEL RIDGE AXIS OVER THE WRN GREAT LAKES...THE GFS SUGGESTS THAT 850-700 MB THETA-E ADVECTION AND 300K-305K ISENTROPIC ASCENT FROM THE UPPER MS VALLEY WILL SURGE INTO WRN LAKE SUPERIOR AND PORTIONS OF WEST UPPER MI ON SAT. THE CANADIAN GLOBAL ALSO SHOWS A SIMILAR SCENARIO. AS THE MAIN SHRTWV LIFTS OUT OF THE SW CONUS 800-600 MB WARMING WILL LEAVE THE AREA UNDER A STRENGTHENING CAP...PER GFS FCST SOUNDINGS. FOR NOW...ONLY SLIGHT CHANCE SHRA/TSRA POPS WERE INCLUDED OVER THE WEST SAT NIGHT INTO SUN...CLOSEST TO THE MOISTURE AXIS AND WHERE SOME ELEVATED CONVECTION COULD MOVE IN AFTER DEVELOPING OVER MN (WHERE THE CAP WOULD BE WEAKER). FCST SOUNDINGS SUGGEST THAT WITH THE WARM AIR SURGE MIXING TO 800 MB WOULD BOOST MAX READINGS TO AT LEAST 70 F. SO...TEMPS WERE RAISED SEVERAL NOTCHES TO NEAR 00Z GFS GUIDANCE VALUES...WHICH MAY BE STILL BE TOO CONSERVATIVE...GIVEN THAT READINGS WOULD BE ABOUT 20 F ABOVE CLIMATOLOGY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 435 AM EDT TUE APR 17 2007 .DISCUSSION... MAIN FCST CONCERNS ARE PCPN CHANCE/TYPE TODAY ALONG WITH CLOUDS/TEMPS. WV IMAGERY AND RUC ANALYSIS INDICATED A BLOCKY PATTERN WITH A TROF OVER THE WRN CONUS...A RDG FROM CO/NM TO NW ONTARIO...AND A DOMINANT NRN STREAM LOW OVER THE WRN ATLANTIC WITH A TROUGH WESTWARD TOWARD A SMALLER LOW OVER THE WRN GREAT LAKES. A SRN STREAM TROUGH WAS ALSO MOVING FROM THE SRN PLAINS INTO THE SE CONUS. AT THE SFC...HIGH PRES OVER NRN ONTARIO AND HUDSON BAY WAS PUSHING NE WINDS THROUGH THE UPPER GREAT LAKES. KAPX RADAR AND SFC OBS SHOWED A LARGE AREA OF LIGHT RAIN OVER NRN LOWER AND ERN UPPER MI GRADUALLY SPREADING TO THE ESE. THE PCPN WAS SUPPORTED BY MODERATE TO STRONG 500-300 MB QVECTOR CONV ON THE NRN FLANK OF THE LAKE MICHIGAN MID LEVEL LOW. TODAY...RADAR/SATELLITE TRENDS AND NAM/GFS QVECTOR AND QPF PROGS SUGGEST THAT THE AREA OF RAIN WILL GRAZE THE ERN PORTION OF THE CWA WITH MORE PERSISTENT RAIN OR GREATER COVERAGE REMAINING TO THE SOUTH AND EAST. HOWEVER...THE LOCAL LAPSWRF-ARW AN CANADIAN REG GEM SCENARIO WHICH BRING SOME LIGHT PCPN TO KMQT-KIMT BY THIS AFTERNOON ALSO REMAINS POSSIBLE GIVEN TREND TOWARD SIGNIFICANT INCREASE IN LOW AND MID LEVEL MOISTURE ALSO DEPICTED BY THE NAM/GFS. THICKER CLOUDS WILL ALSO KEEP TEMPS FROM CLIMBING MUCH. BOTH THE NAM AND GFS FCST SNDGS DROP TEMPS IN THE SFC TO 800 MB LAYER ENOUGH FOR MAINLY SNOW IN CENTRAL UPPER MI. HOWEVER...WITH TEMPS/DEWPOINTS ALREADY NEAR 40/30...LACK OF ANY SIGNIFICANT CAA...AND MDLS RECENT HISTORY OF TOO MUCH LOW LEVEL COOLING WITH LIGHT PCPN...EXPECT MAINLY JUST RAIN. TONIGHT...EVEN THOUGH THE DYNAMIC SUPPORT FOR THE PCPN WILL DEPARTS TO THE SOUTH...THE CLOUDS WITH LOW AND MID LEVEL MOISTURE REMAIN. SO...TEMPS ARE NOT EXPECTED TO FALL OFF QUITE AS FAR AS GUIDANCE VALUES. THURSDAY THROUGH FRIDAY...A QUIET PERIOD IS EXPECTED AS THE WRN GREAT LAKES ARE DOMINATED BY MID LEVEL AND SFC RIDGING IN AN OMEGA-LIKE PATTERN. THE NAM AND GFS ARE IN GOOD AGREEMENT WITH BRINGING IN DRYING/CLEARING FROM THE ENE THU. RADIATIONAL COOLING UNDER MOSTLY CLEAR SKIES SHOULD ALLOW TEMPS TO FALL INTO THE UPPER 20S INLAND TO LOWER 30S NEAR THE GREAT LAKES. PLENTIFUL SUNSHINE AND 850 TEMPS AROUND 2C SUGGEST MAX READINGS WILL CLIMB TO NEAR 60 INLAND. SOME INCREASE IN CLOUDS IS POSSIBLE OVER THE WEST AS WAA PATTERN DEVELOPS AND THE TAIL END OF A SHRTWV MOVING OUT OF THE NRN PLAINS BRUSHES THE AREA. SATURDAY INTO SUNDAY...AS IS OFTEN THE CASE WITH A SUBSTANTIAL MID LEVEL RIDGE OVER THE GREAT LAKES...THE MDLS HAVE TRENDED A BIT SLOWER IN BRINGING PCPN INTO UPPER MI. SO...ONLY SHOWER CHANCES WERE CONFINED TO WEST CWA SAT NIGHT. SUNDAY MAY ALSO END UP REMAINING DRY EXCEPT FOR THE FAR WEST CWA PER 00Z/18 ECMWF AND GFS...BUT ENOUGH UNCERTAINTY REMAINS WITH THE TIMING OF THE MAIN SHRTWV EMERGING FROM THE PLAINS AND THE PATTERN PROGRESSION TO KEEP LOWER CHANCE POPS GOING. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 230 PM MDT WED APR 18 2007 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY... FAIRLY ACTIVE SHORT TERM AS A SHARP UPPER TROUGH CONTINUES LIFTING FROM THE CENTRAL ROCKIES INTO BIG SKY COUNTRY. COMPLEX SURFACE SETUP WITH THE MAIN SURFACE LOW SITTING IN NORTHERN WYOMING AND A STATIONARY FRONTAL BOUNDARY STRETCHING FROM NEAR BILLINGS TO JUST WEST OF MALTA. EAST OF THIS FRONT A BROKEN CIRRIFORM DECK HAS BEEN COVERING MUCH OF THE CWA THUS FAR ALTHOUGH TEMPS HAVE STILL MANAGED TO WARM UP ENOUGH. IT APPEARS THE BEST LARGE SCALE ASCENT IS STARTING TO NOSE INTO OUR SOUTHERN ZONES WITH AN EXPANDING TCU FIELD NEAR BILLINGS. EXPECT THUNDERSTORMS TO DEVELOP FROM BILLINGS NORTHWARD ALONG/NEAR THE SURFACE BOUNDARY WHERE LOW LEVEL MOISTURE CONVERGENCE IS THE STRONGEST. LATEST RUC CYCLE CONTINUES TO GENERATE SURFACE-BASED CAPES AS HIGH AS 1600J/KG BY THIS EVENING BEFORE BECOMING ELEVATED. NEWEST SPC SWODY1 HAS BEEN UPGRADED TO SLIGHT RISK AND FEEL POTENTIAL FOR ROTATING UPDRAFTS IS REASONABLE GIVEN DECENT HODOGRAPH ARCING FROM 0-3KM. THE SURFACE FRONT WILL WORK EAST ACROSS THE SOUTHERN ZONES BY THURSDAY AFTERNOON ALLOWING BETTER LIFT AND PRECIPITATION TO SPREAD NORTHEASTWARD. ENOUGH DYNAMIC COOLING IN STOCK THAT RAIN/SNOW MIX THURSDAY NIGHT OVER MUCH OF THE AREA LOOKS REASONABLE. BY FRIDAY THE STORM SYSTEM WILL HAVE LIFTED INTO SASKATCHEWAN AND POPS WERE CUT BACK EVEN FURTHER GIVEN REASONABLE MODEL AGREEMENT. LACK OF COLD AIR WITH THIS SYSTEM WILL KEEP TEMPS NEAR TO ABOVE NORMAL THROUGH FRIDAY. MCZ .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY... FEW CHANGES TO THE EXTENDED FORECAST AS MODELS REMAIN IN DECENT AGREEMENT WITH FAIRLY BENIGN PATTERN THROUGH THE PERIOD. MAJOR STORM FOR THE SHORT TERM LIFTS INTO CENTRAL CANADA AT THE BEGINNING OF THE PERIOD ALTHOUGH TROF REMAINS OVER THE WEST. WITH EASING OF BLOCK IN THE EAST...MODELS INDICATE SECOND SHORTWAVE TO FOLLOW MORE CONVENTIONAL TRACK FROM THE DESERT SOUTHWEST INTO THE CENTRAL PLAINS...KEEPING MOST SIGNIFICANT PRECIPITATION TO THE SOUTH OF MONTANA. SPLIT DEVELOPS IN THE FLOW BY THE BEGINNING OF NEXT WEEK WITH ANOTHER SHORTWAVE DIVING TOWARD THE FOUR CORNERS AND CUTTING OFF AS RIDGE DEVELOPS OVER WESTERN CANADA. FORECAST OF TEMPERATURES NEAR OR SLIGHTLY ABOVE NORMAL WITH FAIRLY DRY WESTERLY FLOW SEEMS REASONABLE SO MADE ONLY MINOR ADJUSTMENTS TO GOING FORECAST. EBERT PREVIOUS LONG TERM DISCUSSION...WITH ALL THE INTEREST IN THE SHORT TERM...THE LONG TERM LOOKS QUIET AND BENIGN. NO MAJOR SYSTEMS THREATEN OUR AREA...AND THICKNESSES...500 MB HEIGHTS...850 MB TEMPS ALL INDICATE NEAR NORMAL TEMPS WITH LITTLE CHANGE THRU THE PERIOD. THE UPPER PATTERN IS IN A SPLIT FLOW PATTERN WITH ALL MODELS INDICATING ANOTHER CLOSED UPPER LOW MOVING WELL TO OUR SOUTH. LINGERING UPPER TROUGH AND SW FLOW ALOFT OVER AREA SAT MAY GENERATE ISOLATED SHOWERS...OTHERWISE NOTHING VERY CLEAR CUT FOR ANY POPS WITH NO MAJOR SYSTEMS AFFECTING OUR AREA. THE NORTHERN BRANCH OF THE SPLIT DOES HAVE A WEAK SHORTWAVES OR TWO LATE IN THE PERIOD...NOT MUCH TO LATCH ONTO FOR MODEL AGREEMENT AND TIMING THOUGH...SO WILL HAVE SUB-CLIMO POPS. NO BIG HIGH PRESSURE SYSTEMS EITHER...SO GOING MIDDLE GROUND OF LOTS OF PARTLY CLOUDY PERIODS...LOWERED MOST SKY COVER. SIMONSEN && .AVIATION... VFR WITH STRONG SOUTHEAST WINDS THROUGH THE EVENING. ISOLATED THUNDERSTORMS ARE POSSIBLE AROUND THE AREA OVERNIGHT...BRIEFLY DROPPING FLIGHT CONDITIONS TO MVFR. RAIN WITH REDUCED CEILINGS AND POSSIBLY VISIBILITIES IS EXPECTED TO BE MORE WIDESPREAD BY THURSDAY MORNING. RAE && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR FORT PECK LAKE. && $$ WEATHER.GOV/GLASGOW mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 1125 AM PDT WED APR 18 2007 .SYNOPSIS...A STRONG COLD FRONT WILL SWEEP THROUGH THE SOUTHERN GREAT BASIN AND MOJAVE DESERT TODAY USHERING IN MUCH COOLER TEMPERATURES AND STRONG WINDS. THE REGION WILL BE BETWEEN STORMS THURSDAY WITH THE NEXT SYSTEM SET TO BRING UNSETTLED WEATHER AND COOLER TEMPERATURES FRIDAY. YET ANOTHER STORM IS FORECAST TO IMPACT THE AREA SUNDAY AND MONDAY. && .UPDATE...OBSERVATIONS AT 1730Z INDICATED ADVISORY LEVEL NORTHWEST WINDS OVER CENTRAL NYE AND WESTERN LINCOLN COUNTIES BEHIND THE FRONT. THE WIND ADVISORY WAS EXPANDED TO INCLUDE LINCOLN COUNTY AND EXTENDED UNTIL 5 PM FOR ESMERALDA/CENTRAL NYE COUNTIES. THE LATEST PRESSURE GRADIENT TRENDS DO NOT APPEAR TO SUPPORT ADVISORY LEVELS OVER EXTREME SOUTHERN NEVADA AND THE WIND ADVISORY WAS ALLOWED TO EXPIRE AT 11 AM PDT. 1005 AM PDT UPDATE...NORTHWEST WINDS WERE SPREADING INTO THE NORTHWEST PART OF THE LAS VEGAS VALLEY AT 1630Z BEHIND THE FRONT SLIDING DOWN THROUGH SOUTHERN NEVADA. BOTH THE 12Z NAM AND LATEST RUC HAD A GOOD HANDLE ON THE TIMING OF THE FRONT AND BOTH SHOW WINDS DECREASING BEHIND THE FRONT AS THE SURFACE LOW OVER SRN UTAH QUICKLY SHIFTS EAST. WINDS SHOULD BRIEFLY GUST OVER 40 MPH IN SOME AREAS THEN DECREASE LATE THIS MORNING AND EARLY THIS AFTERNOON. LOOKS LIKE ADVISORIES WILL PROBABLY EXPIRE ON SCHEDULE AT 11 AM FOR ALL BUT SAN BERNARDINO AND MOHAVE COUNTIES. RELATIVE HUMIDITIES WERE RUNNING HIGH IN MOHAVE COUNTY THIS MORNING...OVER 30 PERCENT...BUT VERY DRY AIR IS EVIDENT JUST UPSTREAM WITH DEWPOINTS IN THE LOWER TEENS IN CENTRAL CLARK COUNTY AND EVEN BELOW ZERO BEHIND THE FRONT IN NORTHWEST CLARK. THIS DRY AIR SHOULD QUICKLY SPREAD INTO MOHAVE COUNTY DURING THE LATE MORNING AND EARLY AFTERNOON AND VERIFY THE RED FLAG WARNING. && .AVIATION...FOR KLAS: GUSTY WEST WINDS EXPECTED TO CONTINUE THROUGH MID AFTERNOON THEN BECOMING NORTHWEST. SUSTAINED WINDS BETWEEN 15 AND 25 KTS WITH GUSTS AS HIGH AS 35 KTS ARE EXPECTED. A FEW LOW LEVEL CLOUDS NEAR 10K FT DURING THE LATE MORNING AND AFTERNOON. THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA: GUSTY WEST TO SOUTHWEST WINDS EXPECTED TO PERSIST TODAY AT KDAG AND KEED WITH GUSTS UP TO 40 KTS POSSIBLE. NORTHWEST WINDS WILL CONTINUE AT KDRA AND KVGT WITH GUSTS UP TO 30 KTS. SCATTERED TO LOCALLY BROKEN CLOUD COVER BETWEEN 6 AND 8K FT OVER NORTHERN MOHAVE INYO/NYE/LINCOLN AND ESMERALDA COUNTIES WITH CLEAR SKIES TO THIN CIRRUS OVER SAN BERNARDINO AND SOUTHERN MOHAVE COUNTIES. && .PREV DISCUSSION...422 AM PDT WED APR 18 2007... SHORT TERM...STRONG COLD FRONT RUNNING FROM BISHOP-ELY-WENDOVER EARLY THIS MORNING WITH GUSTY NORTHWEST WINDS OCCURRING BEHIND THE FRONTAL PASSAGE. MEANWHILE...STRONG SOUTHWEST WINDS PRECEDING THE COLD FRONT CONTINUE ACROSS SOUTHERN NEVADA AND EASTERN CALIFORNIA. JETSTREAK OVER SOUTHERN NEVADA WILL HELP ENHANCE WIND GUSTS ACROSS SOUTHERN NEVADA AND NORTHWEST ARIZONA DURING THE NEXT 3-4 HOURS. ONLY SIGNIFICANT CHANGE TO HEADLINES WAS TO CANCEL HIGH WIND WARNING FOR CA ZONES 519 AND 520. WILL REPLACE WARNING WITH AN ADVISORY AS EXPECT PERIOD OF GUSTY NORTHWEST WINDS FOLLOWING COLD FRONT. AS STATED REST OF ADVISORIES LEFT ALONE. ISOLATED SHOWERS POSSIBLE ACROSS NORTHERN LINCOLN COUNTY ALONG COLD FRONT THIS MORNING WITH MORE SHOWERS DEVELOPING IN THE AFTERNOON AS COLD POOL ALOFT UNDER TROUGH MOVES ACROSS EAST CENTRAL NEVADA. SYSTEM PULLS EAST TONIGHT LEAVING AREA UNDER ZONAL FLOW AS NEXT TROUGH APPROACHES THE NORTHERN CALIFORNIA EARLY FRIDAY. TROUGH CONTINUES INLAND FRIDAY WITH SHOWERS SPREADING EAST THROUGHOUT THE DAY. SHOWERS WILL END WITH SKIES CLEARING ACROSS FAR WESTERN ZONES FRIDAY NIGHT AS TROUGH PROGRESSES EAST INTO ARIZONA. .LONG TERM....LONG TERM...AN ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGHOUT THE FORECAST PERIOD. 00Z MODELS IN GOOD AGREEMENT OVERALL AS THE NEXT PACIFIC SYSTEM BEGINS TO AFFECT THE CWA ON FRIDAY MORNING...WITH THE H500 LOW CENTER LOCATED JUST OFFSHORE CENTRAL CALIFORNIA. THE SYSTEM WILL THEN QUICKLY SLIDE SOUTHEAST...WITH THE LOW CENTER QUICKLY PASSING OVER SOUTHERN NEVADA ON FRIDAY NIGHT. HAVE KEPT IN CHANCE POPS FOR MOST OF THE CWA DURING THIS STORM WITH GOOD MOISTURE AND DYNAMICS BULLSEYED RIGHT ACROSS THE CWA. STRONG WINDS OUT OF THE SOUTHWEST CAN BE EXPECTED AS THE SYSTEM APPROACHES ON FRIDAY AFTERNOON. WEAK RIDGING IN BETWEEN SYSTEMS WILL HELP LIMIT CLOUD COVER ON SATURDAY AND EARLY SUNDAY UNTIL A TRAILING SYSTEM MOVES OVER THE AREA SUNDAY AFTERNOON. RIGHT NOW THIS SYSTEM APPEARS TO HOLD A LITTLE MORE MOISTURE WITH PW VALUES CLOSE TO 0.7 INCHES PROGGED ACROSS THE CWA. THINGS WILL THEN CLEAR UP AGAIN LATE MONDAY AS RIDGING BUILDS IN OVER THE AREA. && .FIRE WEATHER...GUSTY SOUTHWEST WINDS WILL OCCUR ACROSS NORTHWEST ARIZONA TODAY. RELATIVE HUMIDITIES WILL DROP OR LOWER TO BELOW THE CRITICAL 15 PERCENT VALUE WITH HIGH FIRE DANGER ACROSS NORTHWEST ARIZONA. A RED FLAG WARNING WILL BE ISSUED FROM 9 AM UNTIL 7 PM MST FOR ARIZONA ZONE 102. LAND MANAGEMENT AGENCIES SHOULD CLOSELY MONITOR THE SITUATION AS ERRATIC FIRE BEHAVIOR WILL LIKELY OCCUR ON ANY FIRE STARTS. && .VEF WATCHES/WARNINGS/ADVISORIES... .NV...WIND ADVISORY UNTIL 5 PM ZONES 14 AND 15. .AZ...WIND ADVISORY UNTIL 7 PM ZONES 1 AND 3. RED FLAG WARNING FROM 9 AM UNTIL 7 PM AZ FIRE WX ZONE 102. .CA...WIND ADVISORY UNTIL 5 PM WEDNESDAY ZONES 523-526. && $$ ADAIR/SALMEN/PIERCE/KENNEDY HTTP://WEATHER.GOV/LASVEGAS nv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 730 PM EDT THU APR 19 2007 .AVIATION /00Z-24Z/... SOME SCT CLDS THIS EVE OTRW MAINLY CLR SKIES OVRNGT AND INTO FRI. STRONG DRY AIR ADVECTING INTO THE REGION SHD PRECLUDE FOG FORMATION OVR NGT. GNRLY WINDS WILL BE LGT AND HAVE LTL EFFECT ON OPS. && .PREV DISCUSSION... /ISSUED 209 PM EDT THU APR 19 2007/ SHORT TERM /TONIGHT THROUGH SUNDAY/... GLOBAL MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH SUNDAY TAKING THE OMEGA BLOCK THAT IS OVER THE CENTRAL PORTION OF THE NORTH AMERICAN CONTINENT AND PUSHING IT EASTWARD. AT THE SAME TIME...THE RIDGE ASSOCIATED WITH THIS BLOCK WILL FLATTEN. WE WILL REMAIN EAST OF THE MID LEVEL/SURFACE RIDGE AXIS THROUGH SATURDAY NIGHT...WITH DRY NORTHERLY FLOW OVER THE CWA. MINOR AMOUNTS OF CLOUD COVER THROUGH THE PERIOD WILL BE GOVERNED BY SOME WEAK MID LEVEL IMPULSES THAT WILL ROTATE THROUGH THE AREA. WITH THE SFC RIDGE NEARING THE AREA BY THE END OF THE WEEKEND...EXPECT TEMPS TO MOVE WELL /10F/ ABOVE SEASONAL NORMS BY THE SATURDAY-SUNDAY TIMEFRAME. THIS EVENING...THE RUC AND NAM PROFILES SUGGEST THE ARRIVAL OF ONE LAST WEAK SHORTWAVE FROM THE EAST AROUND OR JUST AFTER 00Z TONIGHT. NAM/RUC RH PROGS SHOW A LITTLE BIT IN THE WAY OF MID LEVEL MOISTURE ASSOCIATED WITH THIS WAVE...MOSTLY IMPACTING OUR SOUTHEASTERN ZONES. WITH 500 HEIGHTS BUILDING THROUGH THE EVENING...CAN`T SEE THIS WAVE DOING ANYTHING MORE THAN DELAYING THE TRANSITION FROM PCLOUDY TO MCLEAR OVER THE SOUTHERN ZONES THIS EVENING. AFTER THIS WAVE DEPARTS...EXPECT A PROLONGED PERIOD OF DRY WEATHER WITH TEMPERATURES CONTINUING TO CLIMB. MODELS BRING A PRETTY STRONG SHORT WAVE RIDGE THROUGH THE AREA ON FRIDAY...ALLOWING FOR A WONDERFUL DAY. BUFKIT PROFILES ARE QUITE DRY WITH A STRONG SUBSIDENCE INVERSION. GOOD MIXING TO 850 WILL TAP ANY WINDS IN THE LOWER LEVELS AND BRING THEM TO THE SURFACE...BUT THE GRADIENT WON`T BE PARTICULARLY IMPRESSIVE...SO NOTHING MORE THAN 20-25MPH GUSTS ARE EXPECTED. T850 RANGES FROM +4-6C IN THE GUIDANCE...WHICH WOULD GIVE HIGHS IN THE L/MID 60S...AND WE`LL LEAN TOWARDS THE WARMER END BASED ON HOW THE MODELS HAVE BEEN PLAYING CATCH UP WITH THE TEMPS OVER THE PAST FEW DAYS. IT APPEARS WE WILL FINALLY GET A CHANCE TO DRY OUT SOME WITH DEW POINTS REMAINING IN THE U20S/L30S THROUGHOUT THE DAY. TONIGHT...MODELS DROP THE DEWPOINTS RAPIDLY WITH OVER-LAND NORTHEASTERLY FLOW. UPSTREAM OBS FROM OUR CANADIAN NEIGHBORS AND EVEN THOSE OVER NEW ENGLAND INDICATE DEWPOINTS DROPPING INTO THE TEENS. THINK THIS STRONG LLEVEL DRYING WILL HOLD OFF UNTIL OVERNIGHT TONIGHT. THIS SHOULD ALLOW TEMPS TO FALL NICELY TONIGHT...PROBABLY COOLER THAN OVER THE PAST FEW NIGHTS. WILL GENERALLY FOLLOW MET GUIDANCE. THESE DRY READINGS...ALONG WITH A LITTLE BIT OF WIND SHOULD KEEP FOG FROM BEING A PROBLEM. THE DRY WEATHER CONTINUES INTO SATURDAY WITH LITTLE CHANGE. RH PROGS SHOW A LITTLE BIT IN THE WAY OF UPPER LEVEL MOISTENING IN THE AFTERNOON AS A WEAK SHORT WAVE ROTATES TOWARDS THE AREA IN THE NORTHWEST FLOW ALOFT. HOWEVER...THE DAY SHOULD BE SUNNY/MSUNNY AND WITH T850 BETWEEN 5-6C HIGHS AROUND U60S TO AROUND 70 LOOK GOOD. ALTHOUGH DEEP MIXING IS AGAIN EXPECTED...WEAKER GRADIENTS WILL LESSEN THE WINDS EVEN MORE...15MPH OR LESS EVEN IN GUSTS. LLEVEL RHS WILL LIKELY BE A LITTLE HIGHER THAN ON FRIDAY AS BOUNDARY LAYER WIND TRAJECTORIES TAKE MORE OF A TRACK OVER THE LAKES. THIS INCREASED LLEVEL MOISTURE SHOULD HELP KEEP LOWS SATURDAY NIGHT A LITTLE WARMER THAN ON FRIDAY NIGHT...PROBABLY JUST ABOVE FREEZING RATHER THAN AT/JUST BELOW. A LOW PRESSURE SYSTEM WILL MOVE EAST SOUTH OF HUDSON BAY ON SUNDAY AS THE EAST COAST RIDGE BEGINS TO FLATTEN. ALTHOUGH WELL NORTH OF THE CWA...SOME UPPER LEVEL CLOUDINESS MAY FILTER IN FROM THE NORTH. HOWEVER...THE DAY WILL STILL TURN OUT MSUNNY. WITH T850 REACHING 6-7C...U60S/L70S ARE LIKELY FOR HIGHS ACROSS THE CWA. WINDS WILL REMAIN QUITE LIGHT AS THE CREST OF THE SURFACE RIDGE MOVES OVER THE AREA. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... NEXT WEEK WILL START OFF WITH A CONTINUATION OF DRY MILD WEATHER. BY TUESDAY...A COLD FRONT IS EXPECTED TO MOVE ACROSS FROM THE NORTHWEST...ACCOMPANIED BY SOME SHOWERS. AT THIS POINT...THE FRONT LOOKS AS THOUGH IT WILL BE PROGRESSIVE ENOUGH...SO THAT DRIER AND SOMEWHAT COOLER WEATHER SHOULD RETURN FOR WEDNESDAY AND THURSDAY. HYDROLOGY... BAINBRIDGE AND CONKLIN STILL THE PRIMARY SITES OF CONCERN WITH CONKLIN JUST ABOVE FS AND BAINBRIDGE VERY NEAR IT. RIVERS CONTINUE TO BE FED BY SNOWMELT...BUT THIS WILL COME TO AN END SOON. WAVERLY ALSO FORECAST TO COME CLOSE TO FS TOMORROW. HAVE KEPT WARNINGS AS THE ARE ATTM...BUT EXPECT RIVERS TO BEGIN TO FALL ESPECIALLY AS WE MOVE INTO TOMORROW AS THE REMAINING SNOWPACK IS LOST AND WE SEE AN EXTENDED DRY PERIOD. AGAIN...ONLY VERY MINOR FLOODING IS EXPECTED. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...NONE. PA...NONE. && $$ AVIATION...DGM ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 209 PM EDT THU APR 19 2007 .SHORT TERM /TONIGHT THROUGH SUNDAY/... GLOBAL MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH SUNDAY TAKING THE OMEGA BLOCK THAT IS OVER THE CENTRAL PORTION OF THE NORTH AMERICAN CONTINENT AND PUSHING IT EASTWARD. AT THE SAME TIME...THE RIDGE ASSOCIATED WITH THIS BLOCK WILL FLATTEN. WE WILL REMAIN EAST OF THE MID LEVEL/SURFACE RIDGE AXIS THROUGH SATURDAY NIGHT...WITH DRY NORTHERLY FLOW OVER THE CWA. MINOR AMOUNTS OF CLOUD COVER THROUGH THE PERIOD WILL BE GOVERNED BY SOME WEAK MID LEVEL IMPULSES THAT WILL ROTATE THROUGH THE AREA. WITH THE SFC RIDGE NEARING THE AREA BY THE END OF THE WEEKEND...EXPECT TEMPS TO MOVE WELL /10F/ ABOVE SEASONAL NORMS BY THE SATURDAY-SUNDAY TIMEFRAME. THIS EVENING...THE RUC AND NAM PROFILES SUGGEST THE ARRIVAL OF ONE LAST WEAK SHORTWAVE FROM THE EAST AROUND OR JUST AFTER 00Z TONIGHT. NAM/RUC RH PROGS SHOW A LITTLE BIT IN THE WAY OF MID LEVEL MOISTURE ASSOCIATED WITH THIS WAVE...MOSTLY IMPACTING OUR SOUTHEASTERN ZONES. WITH 500 HEIGHTS BUILDING THROUGH THE EVENING...CAN`T SEE THIS WAVE DOING ANYTHING MORE THAN DELAYING THE TRANSITION FROM PCLOUDY TO MCLEAR OVER THE SOUTHERN ZONES THIS EVENING. AFTER THIS WAVE DEPARTS...EXPECT A PROLONGED PERIOD OF DRY WEATHER WITH TEMPERATURES CONTINUING TO CLIMB. MODELS BRING A PRETTY STRONG SHORT WAVE RIDGE THROUGH THE AREA ON FRIDAY...ALLOWING FOR A WONDERFUL DAY. BUFKIT PROFILES ARE QUITE DRY WITH A STRONG SUBSIDENCE INVERSION. GOOD MIXING TO 850 WILL TAP ANY WINDS IN THE LOWER LEVELS AND BRING THEM TO THE SURFACE...BUT THE GRADIENT WON`T BE PARTICULARLY IMPRESSIVE...SO NOTHING MORE THAN 20-25MPH GUSTS ARE EXPECTED. T850 RANGES FROM +4-6C IN THE GUIDANCE...WHICH WOULD GIVE HIGHS IN THE L/MID 60S...AND WE`LL LEAN TOWARDS THE WARMER END BASED ON HOW THE MODELS HAVE BEEN PLAYING CATCH UP WITH THE TEMPS OVER THE PAST FEW DAYS. IT APPEARS WE WILL FINALLY GET A CHANCE TO DRY OUT SOME WITH DEW POINTS REMAINING IN THE U20S/L30S THROUGHOUT THE DAY. TONIGHT...MODELS DROP THE DEWPOINTS RAPIDLY WITH OVER-LAND NORTHEASTERLY FLOW. UPSTREAM OBS FROM OUR CANADIAN NEIGHBORS AND EVEN THOSE OVER NEW ENGLAND INDICATE DEWPOINTS DROPPING INTO THE TEENS. THINK THIS STRONG LLEVEL DRYING WILL HOLD OFF UNTIL OVERNIGHT TONIGHT. THIS SHOULD ALLOW TEMPS TO FALL NICELY TONIGHT...PROBABLY COOLER THAN OVER THE PAST FEW NIGHTS. WILL GENERALLY FOLLOW MET GUIDANCE. THESE DRY READINGS...ALONG WITH A LITTLE BIT OF WIND SHOULD KEEP FOG FROM BEING A PROBLEM. THE DRY WEATHER CONTINUES INTO SATURDAY WITH LITTLE CHANGE. RH PROGS SHOW A LITTLE BIT IN THE WAY OF UPPER LEVEL MOISTENING IN THE AFTERNOON AS A WEAK SHORT WAVE ROTATES TOWARDS THE AREA IN THE NORTHWEST FLOW ALOFT. HOWEVER...THE DAY SHOULD BE SUNNY/MSUNNY AND WITH T850 BETWEEN 5-6C HIGHS AROUND U60S TO AROUND 70 LOOK GOOD. ALTHOUGH DEEP MIXING IS AGAIN EXPECTED...WEAKER GRADIENTS WILL LESSEN THE WINDS EVEN MORE...15MPH OR LESS EVEN IN GUSTS. LLEVEL RHS WILL LIKELY BE A LITTLE HIGHER THAN ON FRIDAY AS BOUNDARY LAYER WIND TRAJECTORIES TAKE MORE OF A TRACK OVER THE LAKES. THIS INCREASED LLEVEL MOISTURE SHOULD HELP KEEP LOWS SATURDAY NIGHT A LITTLE WARMER THAN ON FRIDAY NIGHT...PROBABLY JUST ABOVE FREEZING RATHER THAN AT/JUST BELOW. A LOW PRESSURE SYSTEM WILL MOVE EAST SOUTH OF HUDSON BAY ON SUNDAY AS THE EAST COAST RIDGE BEGINS TO FLATTEN. ALTHOUGH WELL NORTH OF THE CWA...SOME UPPER LEVEL CLOUDINESS MAY FILTER IN FROM THE NORTH. HOWEVER...THE DAY WILL STILL TURN OUT MSUNNY. WITH T850 REACHING 6-7C...U60S/L70S ARE LIKELY FOR HIGHS ACROSS THE CWA. WINDS WILL REMAIN QUITE LIGHT AS THE CREST OF THE SURFACE RIDGE MOVES OVER THE AREA. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... NEXT WEEK WILL START OFF WITH A CONTINUATION OF DRY MILD WEATHER. BY TUESDAY...A COLD FRONT IS EXPECTED TO MOVE ACROSS FROM THE NORTHWEST...ACCOMPANIED BY SOME SHOWERS. AT THIS POINT...THE FRONT LOOKS AS THOUGH IT WILL BE PROGRESSIVE ENOUGH...SO THAT DRIER AND SOMEWHAT COOLER WEATHER SHOULD RETURN FOR WEDNESDAY AND THURSDAY. && .AVIATION /191800Z-201800Z/... VFR WILL PREVAIL AREA-WIDE...AS DRIER AIR MOVES IN LATER THIS AFTERNOON...LEADING TO GENERALLY CLEAR SKIES FOR THE REST OF THE PERIOD. NORTH WINDS AROUND 10 KT THIS AFTERNOON...WILL BECOME LIGHT OVERNIGHT...THEN INCREASE AGAIN TO ABOUT 10 KT BY LATE THURSDAY MORNING. && .HYDROLOGY... BAINBRIDGE AND CONKLIN STILL THE PRIMARY SITES OF CONCERN WITH CONKLIN JUST ABOVE FS AND BAINBRIDGE VERY NEAR IT. RIVERS CONTINUE TO BE FED BY SNOWMELT...BUT THIS WILL COME TO AN END SOON. WAVERLY ALSO FORECAST TO COME CLOSE TO FS TOMORROW. HAVE KEPT WARNINGS AS THE ARE ATTM...BUT EXPECT RIVERS TO BEGIN TO FALL ESPECIALLY AS WE MOVE INTO TOMORROW AS THE REMAINING SNOWPACK IS LOST AND WE SEE AN EXTENDED DRY PERIOD. AGAIN...ONLY VERY MINOR FLOODING IS EXPECTED. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...NONE. PA...NONE. && $$ SHORT TERM...JMA LONG TERM...MLJ AVIATION...MLJ HYDROLOGY...JMA ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 124 PM EDT THU APR 19 2007 .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... NEXT WEEK WILL START OFF WITH A CONTINUATION OF DRY MILD WEATHER. BY TUESDAY...A COLD FRONT IS EXPECTED TO MOVE ACROSS FROM THE NORTHWEST...ACCOMPANIED BY SOME SHOWERS. AT THIS POINT...THE FRONT LOOKS AS THOUGH IT WILL BE PROGRESSIVE ENOUGH...SO THAT DRIER AND SOMEWHAT COOLER WEATHER SHOULD RETURN FOR WEDNESDAY AND THURSDAY. -MJ && .AVIATION /18Z-18Z/... VFR WILL PREVAIL AREA-WIDE...AS DRIER AIR MOVES IN LATER THIS AFTERNOON...LEADING TO GENERALLY CLEAR SKIES FOR THE REST OF THE PERIOD. NORTH WINDS AROUND 10 KT THIS AFTERNOON...WILL BECOME LIGHT OVERNIGHT...THEN INCREASE AGAIN TO ABOUT 10 KT BY LATE THURSDAY MORNING. -MJ && .PREV DISCUSSION... /ISSUED 1007 AM EDT THU APR 19 2007/ UPDATE... WILL UPDATE TO BOOST TEMPS JUST A TAD AS PRETTY MUCH FULL MIXING IS EXPECTED OVER NORTHERN AREAS THROUGH THE DAY. MORNING VIS IMAGERY AND AREA WEBCAMS SHOW PRETTY GOOD CLEARING THIS MORNING. T925 AT 12Z WAS ABOUT 3C...BUT SHORT TERM RUC/NAM FORECASTS SHOW 925 WARMING TOWARDS 6-7C TODAY..WHICH WOULD GIVE U50S UNDER FULL MIXING. WILL USE U50S IN THE NORTH...BUT MORE LIKE M50S OVER CENTRAL AND SOUTHERN AREAS WHERE CLOUDS WILL HOLD ON LONGER. CLEARING WILL CONTINUE TO PUSH IN FROM THE NORTH AND EAST AS WE HEAD INTO THE AFTERNOON. -JMA HYDROLOGY... WARNINGS CONTINUE AT CONKLIN/BAINBRIDGE WITH CONKLIN JUST ABOVE FS AND BAINBRIDGE RIGHT AT FS. WILL SEE HOW THESE POINTS RESPOND TO SNOWMELT TODAY TO DETERMINE HOW LONG THE MINOR FLOODING WILL CONTINUE. WILL ALSO HAVE TO WATCH WAVERLY TODAY AS WELL...AS NEW FORECASTS BRING THIS POINT CLOSE...BUT NOT QUITE TO FLOOD STAGE TOMORROW AFTERNOON. GRIDS/ZONES ARE OUT. -JMA PREV DISCUSSION... /ISSUED 636 AM EDT THU APR 19 2007/ AVIATION /12Z-12Z/... WEAKENING SHORT WAVE IS ROTATING THROUGH EASTERN NY STATE, HELPING SPUR A FEW SPRINKLES OVER THE REGION. A BROKEN VFR DECK IS EXPECTED FOR MUCH OF THE DAY, WITH THE POTENTIAL FOR SOME PATCHY FOG AT KITH THROUGH 15Z. CLEARING WILL SLOWLY WORK FROM NORTH TO SOUTH THIS AFTERNOON. EXPECT SKIES TO SCATTER OUT AT KSYR AND KRME AROUND 16Z. IT WILL LIKELY TAKE UNTIL 19Z-21Z FOR THE REMAINING TERMINALS TO SCATTER OUT. CLEAR SKIES AND LIGHT WINDS ARE FORECAST TONIGHT. DJP PREV DISCUSSION... /ISSUED 223 AM EDT THU APR 19 2007/ SHORT TERM... THE EASTERN CYCLONE IS FINALLY EXITING THE ATLANTIC COAST LINE, ALLOWING DRIER AIR AND MUCH WARMER CONDITIONS TO RUSH IN FROM THE SOUTHWEST. WE WERE QUITE A BIT WARMER THAN ANTICIPATED ON WEDNESDAY AS CLOUDS BROKE UP DURING THE MID MORNING HOURS. THE POWER OF THE MID APRIL SUN WAS ON DISPLAY. JUST A BIT OF HEATING THREW TEMPERATURES SEVERAL DEGREES ABOVE FORECAST. WE HAVE TO ANTICIPATE A SIMILAR SCENARIO THIS AFTERNOON. A SHORT WAVE ROTATING THROUGH UPSTATE NY IS PROVIDING THE REGION WITH CLOUDS AND SPRINKLES EARLY THIS MORNING. IT WILL BE SOUTH OF BGM BY MID MORNING, PUTTING THE FORECAST AREA IN NVA. WITH DRYING ALREADY EXPECTED, THURSDAY SHOULD END UP WITH BRIGHTER SKIES THAN DID WEDNESDAY. WE HAVE TRENDED ABOVE GUIDANCE THIS PACKAGE WITH MAXES ANTICIPATED IN THE 50S. THERE IS SOME UPSIDE RISK, ESPECIALLY OVER THE NORTHERN MOST COUNTIES. WEAK NORTHERLY FLOW THIS MORNING WILL PROVIDE ADDITIONAL DRYING THROUGH DOWN SLOPING WINDS, AND THEY WILL ALSO BE THE FIRST TO ENTER THE NVA REGION. WOULD NOT BE SHOCKED TO SEE AN UPGRADE OF TEMPS NEEDED FROM SYR OVER TO RME...PERHAPS 60? IF NOT TODAY, THEN CERTAINLY FRIDAY. THE RIDGE BUILDS EASTWARD FOR FRIDAY AND SATURDAY. THE RESULT WILL BE PLEASANT SPRING WEATHER, WITH TEMPERATURES ABOVE NORMAL FOR THE FIRST TIME IN A LONG TIME. GIVEN UPSTREAM MAXES AND AMPLE SUNSHINE, THINK MID 60S WILL BE EASY TO ATTAIN. IT IS ALWAYS DIFFICULT TO FORECAST THAT FIRST STRETCH OF 70+ TEMPS, AND MOS SEEMS TO STRUGGLE WITH IT MIGHTILY. IT IS A DISTINCT POSSIBILITY WE COULD GET THERE BY SATURDAY OR SUNDAY. DJP LONG TERM... FROM THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...QUIET WEATHER IS EXPECTED TO CONTINUE...WITH WARMING TEMPERATURES AND GENERALLY RAIN-FREE CONDITIONS. A COLD FRONT IS PROGGED TO APPROACH THE AREA MONDAY NIGHT OR TUESDAY...BRINGING OUR NEXT CHANCE OF SHOWERS. ONCE THIS FRONT ARRIVES...EARLY INDICATIONS ARE THAT IT WILL SLOW DOWN OR EVEN STALL SOMEWHERE NEAR THE FORECAST AREA. AS A RESULT...WE`LL MAINTAIN THE CHANCE OF SHOWERS THROUGH WEDNESDAY. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...NONE. PA...NONE. && $$ ny AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BINGHAMTON NY 1007 AM EDT THU APR 19 2007 .UPDATE... WILL UPDATE TO BOOST TEMPS JUST A TAD AS PRETTY MUCH FULL MIXING IS EXPECTED OVER NORTHERN AREAS THROUGH THE DAY. MORNING VIS IMAGERY AND AREA WEBCAMS SHOW PRETTY GOOD CLEARING THIS MORNING. T925 AT 12Z WAS ABOUT 3C...BUT SHORT TERM RUC/NAM FORECASTS SHOW 925 WARMING TOWARDS 6-7C TODAY..WHICH WOULD GIVE U50S UNDER FULL MIXING. WILL USE U50S IN THE NORTH...BUT MORE LIKE M50S OVER CENTRAL AND SOUTHERN AREAS WHERE CLOUDS WILL HOLD ON LONGER. CLEARING WILL CONTINUE TO PUSH IN FROM THE NORTH AND EAST AS WE HEAD INTO THE AFTERNOON. -JMA && .HYDROLOGY... WARNINGS CONTINUE AT CONKLIN/BAINBRIDGE WITH CONKLIN JUST ABOVE FS AND BAINBRIDGE RIGHT AT FS. WILL SEE HOW THESE POINTS RESPOND TO SNOWMELT TODAY TO DETERMINE HOW LONG THE MINOR FLOODING WILL CONTINUE. WILL ALSO HAVE TO WATCH WAVERLY TODAY AS WELL...AS NEW FORECASTS BRING THIS POINT CLOSE...BUT NOT QUITE TO FLOOD STAGE TOMORROW AFTERNOON. GRIDS/ZONES ARE OUT. -JMA && .PREV DISCUSSION... /ISSUED 636 AM EDT THU APR 19 2007/ AVIATION /12Z-12Z/... WEAKENING SHORT WAVE IS ROTATING THROUGH EASTERN NY STATE, HELPING SPUR A FEW SPRINKLES OVER THE REGION. A BROKEN VFR DECK IS EXPECTED FOR MUCH OF THE DAY, WITH THE POTENTIAL FOR SOME PATCHY FOG AT KITH THROUGH 15Z. CLEARING WILL SLOWLY WORK FROM NORTH TO SOUTH THIS AFTERNOON. EXPECT SKIES TO SCATTER OUT AT KSYR AND KRME AROUND 16Z. IT WILL LIKELY TAKE UNTIL 19Z-21Z FOR THE REMAINING TERMINALS TO SCATTER OUT. CLEAR SKIES AND LIGHT WINDS ARE FORECAST TONIGHT. DJP PREV DISCUSSION... /ISSUED 223 AM EDT THU APR 19 2007/ SHORT TERM... THE EASTERN CYCLONE IS FINALLY EXITING THE ATLANTIC COAST LINE, ALLOWING DRIER AIR AND MUCH WARMER CONDITIONS TO RUSH IN FROM THE SOUTHWEST. WE WERE QUITE A BIT WARMER THAN ANTICIPATED ON WEDNESDAY AS CLOUDS BROKE UP DURING THE MID MORNING HOURS. THE POWER OF THE MID APRIL SUN WAS ON DISPLAY. JUST A BIT OF HEATING THREW TEMPERATURES SEVERAL DEGREES ABOVE FORECAST. WE HAVE TO ANTICIPATE A SIMILAR SCENARIO THIS AFTERNOON. A SHORT WAVE ROTATING THROUGH UPSTATE NY IS PROVIDING THE REGION WITH CLOUDS AND SPRINKLES EARLY THIS MORNING. IT WILL BE SOUTH OF BGM BY MID MORNING, PUTTING THE FORECAST AREA IN NVA. WITH DRYING ALREADY EXPECTED, THURSDAY SHOULD END UP WITH BRIGHTER SKIES THAN DID WEDNESDAY. WE HAVE TRENDED ABOVE GUIDANCE THIS PACKAGE WITH MAXES ANTICIPATED IN THE 50S. THERE IS SOME UPSIDE RISK, ESPECIALLY OVER THE NORTHERN MOST COUNTIES. WEAK NORTHERLY FLOW THIS MORNING WILL PROVIDE ADDITIONAL DRYING THROUGH DOWN SLOPING WINDS, AND THEY WILL ALSO BE THE FIRST TO ENTER THE NVA REGION. WOULD NOT BE SHOCKED TO SEE AN UPGRADE OF TEMPS NEEDED FROM SYR OVER TO RME...PERHAPS 60? IF NOT TODAY, THEN CERTAINLY FRIDAY. THE RIDGE BUILDS EASTWARD FOR FRIDAY AND SATURDAY. THE RESULT WILL BE PLEASANT SPRING WEATHER, WITH TEMPERATURES ABOVE NORMAL FOR THE FIRST TIME IN A LONG TIME. GIVEN UPSTREAM MAXES AND AMPLE SUNSHINE, THINK MID 60S WILL BE EASY TO ATTAIN. IT IS ALWAYS DIFFICULT TO FORECAST THAT FIRST STRETCH OF 70+ TEMPS, AND MOS SEEMS TO STRUGGLE WITH IT MIGHTILY. IT IS A DISTINCT POSSIBILITY WE COULD GET THERE BY SATURDAY OR SUNDAY. DJP LONG TERM... FROM THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...QUIET WEATHER IS EXPECTED TO CONTINUE...WITH WARMING TEMPERATURES AND GENERALLY RAIN-FREE CONDITIONS. A COLD FRONT IS PROGGED TO APPROACH THE AREA MONDAY NIGHT OR TUESDAY...BRINGING OUR NEXT CHANCE OF SHOWERS. ONCE THIS FRONT ARRIVES...EARLY INDICATIONS ARE THAT IT WILL SLOW DOWN OR EVEN STALL SOMEWHERE NEAR THE FORECAST AREA. AS A RESULT...WE`LL MAINTAIN THE CHANCE OF SHOWERS THROUGH WEDNESDAY. && .BGM WATCHES/WARNINGS/ADVISORIES... NY....NONE. PA...NONE. && $$ ny AREA FORECAST DISCUSSION...CORRECTED TIMES IN AVIATION SECTION NATIONAL WEATHER SERVICE BINGHAMTON NY 124 PM EDT WED APR 18 2007 .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... FROM THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...QUIET WEATHER IS EXPECTED TO CONTINUE...WITH WARMING TEMPERATURES AND GENERALLY RAIN-FREE CONDITIONS. A COLD FRONT IS PROGGED TO APPROACH THE AREA MONDAY NIGHT OR TUESDAY...BRINGING OUR NEXT CHANCE OF SHOWERS. ONCE THIS FRONT ARRIVES...EARLY INDICATIONS ARE THAT IT WILL SLOW DOWN OR EVEN STALL SOMEWHERE NEAR THE FORECAST AREA. AS A RESULT...WE`LL MAINTAIN THE CHANCE OF SHOWERS THROUGH WEDNESDAY. -MJ && .AVIATION /18Z-18Z/... MAINLY VFR CONDITIONS WILL PERSIST INTO THIS EVENING. BRIEF PERIODS OF MVFR CEILINGS ARE POSSIBLE THIS AFTERNOON AT KELM...KITH...AND KBGM. LATE TONIGHT INTO EARLY THURSDAY...SOME DETERIORATION IS ANTICIPATED...MAINLY AT KBGM...KELM...KITH...AND KAVP. MVFR CEILINGS ARE EXPECTED TO PREVAIL THIS PERIOD AT THESE TERMINALS. BY MIDDAY THURSDAY...IMPROVEMENT TO VFR IS EXPECTED AREA-WIDE...AS DRIER AIR COMES BACK INTO THE REGION. -MJ && .PREV DISCUSSION... /ISSUED 1116 AM EDT WED APR 18 2007/ UPDATE... WILL ISSUE A LATE MORNING UPDATE TO BUMP THE TEMPS UP ONE MORE TIME. THE RUC NICELY SHOWS AN AREA OF NVA ROTATING TOWARDS OUR CWA ATTM WHICH SHOULD ALLOW FOR THE PARTIAL SUNSHINE TO CONTINUE INTO THE AFTERNOON. THIS SHOULD ALLOW MIXING TO 925 WHICH...GIVEN CURRENT TEMPS AT THAT LEVEL WILL ALLOW HIGHS TO REACH THE 45-50 RANGE. STILL FEEL THE DAY WILL END UP MCLOUDY...BUT HAVE LOWERED SKY COVERAGE A BIT TO REFLECT MORE IN THE WAY OF FILTERED SUNSHINE. ZONES/GRIDS ARE OUT. -JMA PREV DISCUSSION... /ISSUED 950 AM EDT WED APR 18 2007/ UPDATE... UPDATE THIS MORNING TO UP TEMPS AND DROP POPS FOR THE DAYTIME HOURS TODAY. A HOLE IN THE CLOUDINESS FROM SYR TO RME HAS ALLOWED TEMPS TO MOVE WELL AHEAD OF THE PREVIOUS FORECAST...AND WILL LIKELY TOP OUT IN THE M40S. T925 WOULD SUPPORT U40S IF WE COULD GET MIXING TO THAT LEVEL...BUT DON`T EXPECT ANY PLACE TO END THE DAY BETTER THAN MOSTLY CLOUDY...SO WILL UNDERCUT THIS VALUE JUST A TAD. THIS ALSO GIVES SOME CREDENCE TO THE SNOWPACK. HAVE LOWERED POPS TO NIL THIS MORNING...OUTSIDE OF A POSSIBLE SPRINKLE. THIS AFTERNOON...WITH CONTINUED COOL TEMPS ALOFT AND MOISTURE CONTINUING TO STREAM WEST AROUND THE NORTHWEST ATLANTIC VORTEX...COULD SEE SOME SHRA POP UP. MOST OF THE AREA WILL BE UNDER WEAK NVA HOWEVER. SO...HAVE USED ISO WORDING EXCEPT OVER OUR FAR EASTERN ZONES WHERE PROXIMITY TO BETTER MOISTURE...AND THE APPROACH OF A WEAK SHORTWAVE BY LATE AFTERNOON MAY PROVIDE FOR A LITTLE BETTER COVERAGE. HYDROLOGY... STILL WATCHING CONKLIN THIS MORNING WITH AN EXPECTED CREST VERY CLOSE TO FLOOD STAGE THIS EVENING. NOTHING MORE THAN VERY MINOR FLOODING WOULD BE EXPECTED HERE. OUTSIDE OF THIS...RIVERS ARE HIGH BUT SHOULD REMAIN WITHIN THEIR BANKS. UPDATED GRIDS/ZONES ARE OUT. -JMA PREV DISCUSSION... /ISSUED 625 AM EDT WED APR 18 2007/ AVIATION /12Z-12Z/... WIDESPREAD OVERCAST CONDITIONS EXPECTED THIS MORNING AS MOISTURE OVER REGION REMAINS FIXED IN LOWER ATMOSPHERE. WILL FORECAST MAINLY MVFR CIGS WITH SOME TEMPO IFR ON THE HIGH ELEVATIONS. WINDS WILL BE NORTHERLY AT 7-10 KTS. EXPECT CIGS TO IMPROVE TO 3500-4500 FEET THIS AFTERNOON. DJP PREV DISCUSSION... /ISSUED 251 AM EDT WED APR 18 2007/ SHORT TERM /TODAY THROUGH FRIDAY/... PERSISTENT CYCLONIC FLOW OFF THE ATLANTIC SEABOARD WILL CONTINUE TO CIRCULATE MOISTURE, POLAR AIR, AND WEAK IMPULSES OVER OUR REGION. THIS WILL KEEP TEMPERATURES MUCH BELOW NORMAL THROUGH TODAY, WITH SCATTERED SHOWERS THROUGH AT LEAST EARLY THURSDAY. A SHORT WAVE MOVING SOUTH THROUGH THE FLOW WILL GENERATE A FEW MORE SHOWERS TONIGHT. WE ARE FORECASTING MAINLY RW- AS LIFT IS WEAK, AND TEMPERATURES WILL BE SIMILAR TO THIS MORNING. SOME DRYING TAKES PLACE ON THURSDAY, BUT NOT ENOUGH TO COMPLETELY ELIMINATE CHC POPS OVER EASTERN FORECAST AREA. HOWEVER GIVEN LIKELIHOOD FOR DRY CONDITIONS, AND A RISING CEILING, WE SHOULD BE ABLE TO RECOVER SEVERAL DEGREES WELL INTO THE 40S. THE PATTERN FINALLY BREAKS LATE THURSDAY WHEN CYCLONE PULLS EAST AND CENTRAL PLAINS RIDGE BUILDS INTO LOWER MI AND OH. THE COMBINATION OF RAPIDLY CLEARING SKIES AND RISING THICKNESS SHOULD LEAD TO A RATHER DRAMATIC RISE IN TEMPERATURES. FIRST GUESS IS A MAX RANGE OF 57-62 ACROSS THE REGION. THE RISK IS TO THE UPSIDE IF THE RIDGE AXIS MAKES IT INTO WESTERN NY BY LATE AFTERNOON. DJP LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LEFTOVER CYCLONIC FLOW AND ASSOCIATED MOISTURE WILL PINWHEEL SOUTH OF OUR FORECAST AREA AS CUTOFF OVER THE NORTHWESTERN ATLANTIC BEGINS TO PULL EAST AS AN OMEGA BLOCK DEVELOPS OVER THE NORTH AMERICAN CONTINENT. AS WE MOVE TOWARDS THE WEEKEND...THIS PATTERN SHIFTS EAST WITH BUILDING HEIGHTS AND MODERATING TEMPERATURES. THE MODERATING WILL BE RELATIVELY SLOW UNTIL THE CREST OF THE SFC RIDGE ASSOCIATED WITH THE OMEGA BLOCK MOVES EAST OF THE AREA. THIS DOESN`T APPEAR TO HAPPEN UNTIL THE MIDDLE OF THE WEEKEND. AFTER THIS POINT...TEMPERATURES MAY ACTUALLY MOVE ABOVE SEASONAL NORMS. THE RIDGE BEGINS TO FLATTEN AS WE HEAD INTO EARLY NEXT WEEK ALLOWING BROAD SOUTHWESTERLY FLOW TO DEVELOP OVER THE FCST AREA...LIKELY BRINGING US OUR NEXT WEATHER MAKER. MOST OF THE PERIOD APPEARS TO BE PCP FREE. THERE COULD BE A RESIDUAL SHOWER ON FRIDAY MORNING...BUT AFTER THAT POINT...THE NEXT CHC FOR PCP WILL HOLD OFF UNTIL MONDAY...AND MORE LIKELY TUESDAY. AT THIS POINT...THE PCP FOR EARLY NEXT WEEK DOES NOT APPEAR TO BE HEAVY. IT WILL ALSO TAKE THE FORM OF RAIN. HYDROLOGY... CONKLIN MAY APRCH FS THIS AFTN, OTRW NO PRBLMS ARE XPCTD IN THE SHORT TERM. PTRN OF GRADUALLY RISING TEMPS WILL FAVOR A NICE, SLOW RELEASE OF THE SNOWPACK CRNTLY OVER THE FCST AREA. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...NONE. PA...NONE. && $$ ny AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BINGHAMTON NY 1116 AM EDT WED APR 18 2007 .UPDATE... WILL ISSUE A LATE MORNING UPDATE TO BUMP THE TEMPS UP ONE MORE TIME. THE RUC NICELY SHOWS AN AREA OF NVA ROTATING TOWARDS OUR CWA ATTM WHICH SHOULD ALLOW FOR THE PARTIAL SUNSHINE TO CONTINUE INTO THE AFTERNOON. THIS SHOULD ALLOW MIXING TO 925 WHICH...GIVEN CURRENT TEMPS AT THAT LEVEL WILL ALLOW HIGHS TO REACH THE 45-50 RANGE. STILL FEEL THE DAY WILL END UP MCLOUDY...BUT HAVE LOWERED SKY COVERAGE A BIT TO REFLECT MORE IN THE WAY OF FILTERED SUNSHINE. ZONES/GRIDS ARE OUT. -JMA && .PREV DISCUSSION... /ISSUED 950 AM EDT WED APR 18 2007/ UPDATE... UPDATE THIS MORNING TO UP TEMPS AND DROP POPS FOR THE DAYTIME HOURS TODAY. A HOLE IN THE CLOUDINESS FROM SYR TO RME HAS ALLOWED TEMPS TO MOVE WELL AHEAD OF THE PREVIOUS FORECAST...AND WILL LIKELY TOP OUT IN THE M40S. T925 WOULD SUPPORT U40S IF WE COULD GET MIXING TO THAT LEVEL...BUT DON`T EXPECT ANY PLACE TO END THE DAY BETTER THAN MOSTLY CLOUDY...SO WILL UNDERCUT THIS VALUE JUST A TAD. THIS ALSO GIVES SOME CREDENCE TO THE SNOWPACK. HAVE LOWERED POPS TO NIL THIS MORNING...OUTSIDE OF A POSSIBLE SPRINKLE. THIS AFTERNOON...WITH CONTINUED COOL TEMPS ALOFT AND MOISTURE CONTINUING TO STREAM WEST AROUND THE NORTHWEST ATLANTIC VORTEX...COULD SEE SOME SHRA POP UP. MOST OF THE AREA WILL BE UNDER WEAK NVA HOWEVER. SO...HAVE USED ISO WORDING EXCEPT OVER OUR FAR EASTERN ZONES WHERE PROXIMITY TO BETTER MOISTURE...AND THE APPROACH OF A WEAK SHORTWAVE BY LATE AFTERNOON MAY PROVIDE FOR A LITTLE BETTER COVERAGE. HYDROLOGY... STILL WATCHING CONKLIN THIS MORNING WITH AN EXPECTED CREST VERY CLOSE TO FLOOD STAGE THIS EVENING. NOTHING MORE THAN VERY MINOR FLOODING WOULD BE EXPECTED HERE. OUTSIDE OF THIS...RIVERS ARE HIGH BUT SHOULD REMAIN WITHIN THEIR BANKS. UPDATED GRIDS/ZONES ARE OUT. -JMA PREV DISCUSSION... /ISSUED 625 AM EDT WED APR 18 2007/ AVIATION /12Z-12Z/... WIDESPREAD OVERCAST CONDITIONS EXPECTED THIS MORNING AS MOISTURE OVER REGION REMAINS FIXED IN LOWER ATMOSPHERE. WILL FORECAST MAINLY MVFR CIGS WITH SOME TEMPO IFR ON THE HIGH ELEVATIONS. WINDS WILL BE NORTHERLY AT 7-10 KTS. EXPECT CIGS TO IMPROVE TO 3500-4500 FEET THIS AFTERNOON. DJP PREV DISCUSSION... /ISSUED 251 AM EDT WED APR 18 2007/ SHORT TERM /TODAY THROUGH FRIDAY/... PERSISTENT CYCLONIC FLOW OFF THE ATLANTIC SEABOARD WILL CONTINUE TO CIRCULATE MOISTURE, POLAR AIR, AND WEAK IMPULSES OVER OUR REGION. THIS WILL KEEP TEMPERATURES MUCH BELOW NORMAL THROUGH TODAY, WITH SCATTERED SHOWERS THROUGH AT LEAST EARLY THURSDAY. A SHORT WAVE MOVING SOUTH THROUGH THE FLOW WILL GENERATE A FEW MORE SHOWERS TONIGHT. WE ARE FORECASTING MAINLY RW- AS LIFT IS WEAK, AND TEMPERATURES WILL BE SIMILAR TO THIS MORNING. SOME DRYING TAKES PLACE ON THURSDAY, BUT NOT ENOUGH TO COMPLETELY ELIMINATE CHC POPS OVER EASTERN FORECAST AREA. HOWEVER GIVEN LIKELIHOOD FOR DRY CONDITIONS, AND A RISING CEILING, WE SHOULD BE ABLE TO RECOVER SEVERAL DEGREES WELL INTO THE 40S. THE PATTERN FINALLY BREAKS LATE THURSDAY WHEN CYCLONE PULLS EAST AND CENTRAL PLAINS RIDGE BUILDS INTO LOWER MI AND OH. THE COMBINATION OF RAPIDLY CLEARING SKIES AND RISING THICKNESS SHOULD LEAD TO A RATHER DRAMATIC RISE IN TEMPERATURES. FIRST GUESS IS A MAX RANGE OF 57-62 ACROSS THE REGION. THE RISK IS TO THE UPSIDE IF THE RIDGE AXIS MAKES IT INTO WESTERN NY BY LATE AFTERNOON. DJP LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LEFTOVER CYCLONIC FLOW AND ASSOCIATED MOISTURE WILL PINWHEEL SOUTH OF OUR FORECAST AREA AS CUTOFF OVER THE NORTHWESTERN ATLANTIC BEGINS TO PULL EAST AS AN OMEGA BLOCK DEVELOPS OVER THE NORTH AMERICAN CONTINENT. AS WE MOVE TOWARDS THE WEEKEND...THIS PATTERN SHIFTS EAST WITH BUILDING HEIGHTS AND MODERATING TEMPERATURES. THE MODERATING WILL BE RELATIVELY SLOW UNTIL THE CREST OF THE SFC RIDGE ASSOCIATED WITH THE OMEGA BLOCK MOVES EAST OF THE AREA. THIS DOESN`T APPEAR TO HAPPEN UNTIL THE MIDDLE OF THE WEEKEND. AFTER THIS POINT...TEMPERATURES MAY ACTUALLY MOVE ABOVE SEASONAL NORMS. THE RIDGE BEGINS TO FLATTEN AS WE HEAD INTO EARLY NEXT WEEK ALLOWING BROAD SOUTHWESTERLY FLOW TO DEVELOP OVER THE FCST AREA...LIKELY BRINGING US OUR NEXT WEATHER MAKER. MOST OF THE PERIOD APPEARS TO BE PCP FREE. THERE COULD BE A RESIDUAL SHOWER ON FRIDAY MORNING...BUT AFTER THAT POINT...THE NEXT CHC FOR PCP WILL HOLD OFF UNTIL MONDAY...AND MORE LIKELY TUESDAY. AT THIS POINT...THE PCP FOR EARLY NEXT WEEK DOES NOT APPEAR TO BE HEAVY. IT WILL ALSO TAKE THE FORM OF RAIN. HYDROLOGY... CONKLIN MAY APRCH FS THIS AFTN, OTRW NO PRBLMS ARE XPCTD IN THE SHORT TERM. PTRN OF GRADUALLY RISING TEMPS WILL FAVOR A NICE, SLOW RELEASE OF THE SNOWPACK CRNTLY OVER THE FCST AREA. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...NONE. PA...NONE. && $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 1108 AM EDT WED APR 18 2007 .SYNOPSIS... WATER VAPOR SATELLITE AND UPPER AIR DATA ANALYSIS INDICATE A WEAKENING MID AND UPPER LEVEL LOW PUSHING ESE THROUGH THE MID SOUTH AND SOUTHERN TN VALLEY LATE MORNING. THE WEAK SURFACE REFLECTION WAS LOCATED OVER CENTRAL GA (1006 MB). A SURFACE HIGH (1022 MB) WAS LOCATED OVER THE UPPER MIDWEST AT 12Z. THE RIDGING EXTENDED EAST THROUGH NY STATE... THEN SOUTH DOWN THE EASTERN SEABOARD INTO NC. THE WEAKENING MID LEVEL SYSTEM IS FORECAST TO CONTINUE ADVANCING ESE ACROSS GA TODAY AND OFFSHORE OF THE SC COAST TONIGHT. ANOTHER STRONGER UPPER AIR SYSTEM... SEEN NEAR CHICAGO AT 12Z... IS EXPECTED TO DIVE SE TOWARD THE SOUTHERN APPALACHIANS TONIGHT AND THURSDAY. && .SHORT TERM /REST OF TODAY/... THE WEAKENING SOUTHERN BRANCH SYSTEM OVER THE GULF COAST STATES WILL PASS JUST SOUTH OF OUR REGION THIS AFTERNOON AND EVENING. VISIBLE SATELLITE INDICATED MID AND HIGH LEVEL CLOUDS HAD SPREAD EASTWARD ACROSS WESTERN AND CENTRAL NC AS OF 1100 AM. ONLY THE AREAS FROM HALIFAX AND TARBORO WERE STILL CLEAR. RADAR INDICATED SOME PATCHY MID LEVEL RETURNS OVER WESTERN NC... WITH ONLY A FEW SPRINKLES OBSERVED AT THE SURFACE OVER THE FOOTHILLS AND MOUNTAINS. LATE MORNING TEMPERATURES RANGED FROM THE MID 50S NE (ROANOKE RAPIDS) INTO THE MID 60S SOUTHWEST (WADESBORO AND ROCKINGHAM). DEW POINTS RANGED IN THE MID 30S TO LOWER 40S. SURFACE WINDS WERE LIGHT FROM THE NORTH... EXCEPT FOR SOME GUSTS TO NEAR 15 MPH OVER THE COASTAL PLAIN. LATEST SATELLITE DATA SUGGESTS THAT MOSTLY CLOUDY SKIES WILL PREVAIL THIS AFTERNOON. THIS IS SUPPORTED BY THE REGIONAL 12Z RAOBS AND LATEST NAM/RUC SHORT TERM FORECASTS. THERE MAY BE A FEW SPRINKLES... ESPECIALLY OVER THE WESTERN PIEDMONT BUT WILL CONTINUE WITH NON MEASURABLE EVENT FOR TODAY. THE TEMPERATURES WILL BE HELD BACK A BIT DUE TO THE THICKNESS OF THE HIGH CLOUDS EXPECTED TO BE OVER OUR REGION. THE LATE APRIL SUN IS VERY STRONG... SO ANY THIN SPOTS WILL ALLOW TEMPS TO JUMP A FEW DEGREES. THE PREVIOUS TREND OF GOING ON THE WARM SIDE OF GUIDANCE LOOKS GOOD. I WILL CONTINUE THAT TREND AND RAISE THEM A FEW MORE DEGREES BASED ON CURRENT OBSERVATIONS AND THE FACT THAT GUIDANCE HAS BEEN VERIFYING 4-6 DEGREES TOO COOL RECENTLY. EXPECT TO SEE HIGHS IN THE MID 60S OVER THE WESTERN PIEDMONT AND NORTHERN COASTAL PLAIN... RANGING INTO LOWER 70S SOUTH CENTRAL. THE NEXT UPPER AIR SYSTEM NEAR CHICAGO THIS MORNING IS FORECAST TO DIVE SE TOWARD THE APPALACHIANS LATER TONIGHT. LATEST GUIDANCE TRENDS HAVE REDUCED THE POP AND QPF FOR THIS EVENT... WHICH DID NOT LOOK LIKE MUCH TO BEGIN WITH. WE WILL PROBABLY HAVE TO LOWER POP AND REDUCE CURRENT QPF IF LATEST GUIDANCE SUPPORTS THE CURRENT TRENDS. MORE ON THIS LATER. NO OTHER CHANGES NEEDED AT THIS TIME. -BADGETT && .PREV DISCUSSION... /ISSUED 307 AM EDT WED APR 18 2007/ SHORT TERM /TODAY THROUGH FRIDAY NIGHT/... BEGINNING TO SEE AN INCREASE IN HIGH LEVEL CLOUDINESS ACROSS CENTRAL NC, SOME OF IT OROGRAPHICALLY INDUCED. UPPER LEVEL LOW IN VICINITY OF LOWER MS VALLEY EARLY THIS MORNING STILL PROGGED TO WEAKEN/SHEAR APART AS IT TRAVERSES E-SE ACROSS THE DEEP SOUTH AND SE U.S. LATER TODAY/TONIGHT. MAIN AFFECT FROM THIS SYSTEM ON CENTRAL NC WILL BE EXTENSIVE HIGH CLOUDINESS TODAY AS AIRMASS BELOW 700MB TOO DRY TO ALLOW PRECIP TO REACH THE GROUND PLUS DYNAMICS TO GENERATE PRECIP WEAKENING AS SYSTEM MOVES EWD. OPAQUENESS OF CLOUDS WILL PLAY SOME ROLE IN MAX TEMPS TODAY. CONSIDERING THAT WE ARE AVERAGING A COUPLE OF DEGREES WARMER THAN PROGGED AND POTENTIAL FOR AT LEAST PARTIAL SUNSHINE TODAY WILL GO WITH FULL SUN VALUES FROM LOW LEVEL THICKNESSES. THIS GIVES MAX TEMPS RANGING FROM THE LOW/MID 60S NE TO THE UPPER 60S WEST AND SOUTH (NEAR OR SLIGHTLY WARMER THAN MOS). UPPER LEVEL SYSTEM ROTATING AROUND DEEP VORTEX OFF NEW ENGLAND COAST WILL MOVE SEWD TODAY AND TONIGHT AND SHOULD APPROACH WESTERN NC LATE TONIGHT/THU. SHORT TERM MODELS HAVE COME INTO BETTER CONSENSUS WITH THIS SYSTEM AND TEND TO KEEP BEST LIFT/DEEPEST MOISTURE ON THE WESTERN PERIPHERY OF CENTRAL NC. MODELS HAVE BEEN TRENDING WESTWARD WITH TRACK AND THIS TREND PERSIST IN THE LATEST RUN. DUE TO THIS TREND, HAVE LOWERED POPS IN THE NORTHERN COASTAL PLAIN AND FAR NE PIEDMONT. IF WESTWARD SHIFTS CONTINUES AND VERIFIES, LOW LIKELY POPS FOR THE WESTERN AND SOUTHERN PIEDMONT MAY BE TOO HIGH. STILL DECENT MID LEVEL LAPSE RATES ASSOCIATED WITH SYSTEM AS COOL POOL OF -22 TO -25 DEGREES C AT H5 SETTLES OVER REGION THU. HOWEVER LOWEST 5-10K FT OF ATMOSPHERE VERY STABLE. THUS NOT OVERLY IMPRESSED WITH T-STORM POTENTIAL. TEMPTED TO YANK MENTION OF THUNDER FROM FORECAST BUT SINCE SYSTEM IN VICINITY WHEN HEATING OF AIRMASS AT ITS PRIME, WILL LEAVE IN. THICKER CLOUD COVERAGE AND A STEADY N-NE SURFACE FLOW WILL RESULT IN MAX TEMPS 10-15 DEGREES BELOW NORMAL. SYSTEM CONTINUES TO MOVE SEWD THU NIGHT. BY 00Z FRI...APPEARS BEST SHOT AT CONVECTION WILL BE OVER THE FAR SOUTHERN COUNTIES WITH THREAT GREATLY DIMINISHED BY 06Z. CLOUDS GRADUALLY DEPART FRI AS SUBSIDENCE IN THE MID/UPPER LEVELS WILL MIX DRIER AIR TOWARD THE SURFACE. THUS EXPECT DECENT DISPLAY OF SUN FRI AFTERNOON. DEEP NLY FLOW WILL KEEP TEMPS STILL RATHER COOL FOR MID APRIL. (LOW-MID 60S). LONG TERM /SATURDAY THROUGH TUESDAY/... MODERATING TREND TO BEGIN SATURDAY AND CONTINUE INTO EARLY NEXT WEEK. MID/UPPER LEVEL RIDGE BUILDS INTO REGION FROM THE S-SW AS DEEP VORTEX OFF NEW ENGLAND COAST FINALLY LIFTS E-NE. NO RAIN ANTICIPATED THROUGH TUESDAY AS COLD FRONT ASSOCIATED WITH NORTHERN STREAM S/W STALLS TO OUR N-NW MON-TUE AVIATION /06Z-06Z/... AN OCCLUDED MID AND UPPER SYSTEM OVER THE LOWER MISS VALLEY AND GULF COAST STATES WILL CONTINUE TO WEAKEN AS IT MOVES EAST INTO THE SHORTWAVE RIDGE OVER THE SE CONUS. THE ASSOCIATED SHEARED VORT. ENERGY WILL RESULT IN AN INCREASE IN MID AND HIGH CLOUDS THIS MORNING...WITH BROKEN TO OVERCAST CEILINGS AT AROUND 15KFT BY THE AFTERNOON. A MORE ROBUST MID AND UPPER CYCLONE...CURRENTLY OVER THE GREAT LAKES REGION...WILL DIVE SOUTH TOWARDS THE REGION THIS EVENING. CEILINGS WILL BEGIN TO LOWER TO NEAR MVFR CONDITIONS LATE IN THE EVENING AND OVERNIGHT AS UPPER WAVE RE-ESTABLISHES LOW-LEVEL NE MARITIME FEED. WINDS WILL BE LIGHT THROUGH THE FORECAST PERIOD AS WEAK SFC RIDGE FROM THE NORTH EXTENDS OVER CENTRAL NC AS A WEAK SFC LOW PASSES SW OF THE AREA. WINDS WILL VEER TO THE NE LATE IN THE DAY AND IN THE EVENING. AS THE UPPER LEVEL DISTURBANCE PASSES ACROSS THE AREA ON THURSDAY... BULK OF STRONGER DYNAMICS WILL STAY SW OF THE AREA. AS A RESULT... EXPECT MVFR CONDITIONS ON THURSDAY SHOULD BE SHORT-LIVED AND ASSOCIATED WITH PASSING RAIN SHOWERS...MAINLY ACROSS WESTERN TAF SITES. OTHERWISE...EXPECT PREDOMINATELY VFR CONDITIONS THROUGH THE WEEKEND AS SHORTWAVE RIDGE ALOFT BUILDS SLOWLY EAST ACROSS THE AREA. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS... SHORT TERM...BADGETT nc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 1002 AM CDT THU APR 19 2007 .UPDATE...FORECAST PRETTY MUCH ON TRACK BUT WILL NEED TO TWEAK POP/WX AND WIND GRIDS A BIT. 12Z NAM/RUC SHOWING NO PRCIP INTO THE FA UNTIL AFTER 00Z. CONSIDERING RIDGE TO THE EAST AND EXPECTED NORTH PROPAGATION OF UPPER LOW TO THE WEST...THIS MAKES SENSE. WILL REMOVE 30 POPS FOR THIS AFTERNOON ACROSS THE W FA. CURRENT FORECASTED WIND SPEEDS REASONABLE ACROSS MOST OF THE FA...BUT WILL INCREASE GUSTS A BIT. MODEL SOUNDINGS SHOWING ADIABATIC LAYER TO 850MB WITH WINDS IN THIS LAYER INCREASING TO 20-30KTS FROM THE VALLEY EAST. WEST OF THE VALLEY...850MB WINDS INCREASE TO 35KTS. ADJUSTED WIND GUST GRID ACCORDINGLY. STILL THINKING NO WIND ADVISORY WILL BE NEEDED ACROSS THE W FA...BUT WILL MONITOR. && .PREV DISCUSSION... /ISSUED 430 AM CDT THU APR 19 2007/ SHORT TERM... LONGWAVE TROUGH AND RIDGE WAS OVER THE WESTERN AND CENTRAL US RESPECTIVELY. TWO SHORT WAVES FORECAST TO MOVE THROUGH LONGWAVE TROUGH AND INTO THE NORTHERN PLAINS THROUGH THE PERIOD. OMEGA BLOCK OVER ONTARIO WILL BREAK DOWN WITH HIGH SHIFTING SOUTH OVER THE NEXT COUPLE DAYS THEN EAST AFTER SUN. DRY AIR FORM OMEGA BLOCK WILL SHIFT NORTH TONIGHT AS MOISTURE MOVES IN FROM BOTH THE SOUTHEAST AND SOUTHWEST THIS AFTERNOON AND TONIGHT. GFS CROSS SECTION SHOWING BAND OF COLD ADVECTION FROM 850 TO 500 HPA MOVING ACROSS THE AREA LATE TODAY AND TONIGHT. UPPER AIR CHART SHOWING COLD AIR ON WEST SIDE OF UPPER TROUGH OVER THE INTERMOUNTAIN WEST. 60 TO 90 METER HEIGHT FALLS NOTED ON THE EAST SIDE OF TROUGH AT 700 HPA. THETA-E RIDGE EXTENDED FROM THE SOUTHERN PLAINS INTO THE WESTERN DAKOTAS AND THE HIGH PLAINS. UPPER LEVEL TROUGH OVER UT WILL ROTATE NORTHEAST OVER EASTERN MT TODAY AND INTO SOUTHERN CANADA TONIGHT. UPPER TROUGH AXIS WILL ROTATE THROUGH THE RED RIVER VALLEY THIS EVENING WITH JET DIVING EAST ON THE BACK SIDE OF THE TROUGH. WATER VAPOR LOOP SHOWS UPPER LEVEL TROUGH OVER UT ROTATING NORTHEAST. MESOSCALE ANALYSIS SHOWS SURFACE MIXING RATIOS INCREASING FROM THE SOUTHEAST WITH WI...IL AND IA CLOUD DECK. OTHERWISE HIGHER SURFACE MIXING RATIOS WERE ALONG THETA-E RIDGE OVER THE HIGH PLAINS. BRIEF RESPITE FRI WITH UPPER RIDGE TO TROUGH PATTERN OVER THE AREA. LOW LEVEL MOISTURE RETURNS NORTH FRI NIGHT AND SAT. LONG TERM... TEMPS TWEAKED. AVIATION... FOG LOOP SHOWS LOW CLOUDS OVER WI IL AND EASTERN IA MOVING WEST AND NORTHWEST. MODEL TRAJECTORY BRINGS THE MOISTURE INTO EASTERN ZONES THIS AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ TG nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 413 PM EDT WED APR 18 2007 .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... COMPLEX UPPER AIR FLOW PATTERN WITH NORTHERN STREAM UPPER LEVEL LOW TO DEVELOP SOUTH THRU INDIANA TONIGHT AND THEN SLIDE ESE INTO CENTRAL KY BY THURSDAY AFTERNOON. AXIS OF FAVORABLE 925MB CONVERGENCE TO DEVELOP ACRS THE SW PORTION OF THE FA THIS EVENING. INSTABILITY IS THE LIMITING FACTOR WITH ELEVATED CAPES AOB 300 J/KG. EXPECTING RAIN SHOWERS TO INCREASE THIS EVENING AS FAVORABLE LOW LEVEL FORCING DEVELOPS. HAVE HIGH CHC POPS ACRS THE SOUTHWEST TONIGHT WITH LIMITED SLIGHT CHC OF TSTMS THIS EVENING ACRS NE KY AND EXTREME SW OHIO. NORTHWESTERLY FLOW ALOFT TO PREVAIL THU/THU NIGHT IN THE WAKE OF THIS UPPER LOW. HAVE LINGERED A CHC OF SHOWERS ACRS THE SOUTH MAINLY IN THE MORNING. EXPECT DECREASING SKIES THU NIGHT WITH SFC HIGH PRESSURE BUILDING INTO THE GREAT LAKES. FROST MAY BE PSBL BY FRI MORNING MAINLY ACRS THE FAR NW WHERE WINDS WL BE THE LIGHTEST AND LOWS IN THE UPPER 30S ARE EXPECTED. FOR NOW CONFIDENCE WAS NOT HIGH ENOUGH FOR A HEADLINE. UPPER LEVEL RIDGE TO BUILD INTO THE GREAT LAKES/OHIO VALLEY FRIDAY INTO THE WEEKEND. EXPECT A WARMING TREND WITH MOSTLY SUNNY SKY CONDITIONS FRIDAY. TEMP WISE...HAVE DEVIATED LITTLE FROM MAV GUID THRU THE PERIOD... GENERALLY GOING AT OR SLIGHTLY BLOW THE GUID THRU THE PERIOD. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL PROVIDE DRY WEATHER SATURDAY AND SUNDAY. LOW PRESSURE MOVING THROUGH THE GREAT LAKES WILL DRAG A COLD FRONT ACROSS THE OHIO VALLEY ON MONDAY...BRINGING A CHANCE FOR THUNDERSTORMS. WITH THE FRONT BECOMING NEARLY STATIONARY ALONG A ZONAL UPPER FLOW...THE CHANCE FOR THUNDERSTORMS WILL PERSIST ON TUESDAY AND WEDNESDAY. TEMPERATURES WILL BE NEAR TO ABOVE AVERAGE THROUGH THE PERIOD. WENT ABOVE MEX GUIDANCE CLOSE TO HPC VALUES. && .PREV DISCUSSION... /ISSUED 220 PM EDT WED APR 18 2007/ AVIATION /18Z-18Z/... LOW LEVEL FORCING HELPING TO INITIATE/MAINTAIN WEAK CONVECTION THAT EXTENDS INTO THE SW PART OF THE ILN FORECAST AREA AS INDICATED BY LATEST 88D IMAGERY. RUC/NAM MODELS SHOWING LOW LEVEL CONVERGENCE PERSISTING ACROSS OUR SW SECTIONS INTO EARLY THURSDAY MORNING. THE BEST CHANCE FOR PRECIP WILL BE ACROSS THE SW TAF SITES AS THIS LOW-LEVEL FORCING COMBINES WITH MID-LEVEL FORCING IN ASSOCIATION WITH THE CLOSED 50H LOW DROPPING SOUTH ACROSS IN. INSTABILITY EXPECTED TO BE WEAK AND LIMITED TO THE EXTREME SW PART OF OUR FORECAST AREA. AT THIS POINT...ONLY CB HAS BEEN INSERTED IN BOTH THE KCVG AND KLUK TAFS FOR 21Z TO 01Z. OTHER THAN THE PRECIP...THE POTENTIAL FOR LOW CIGS WILL BE A PROBLEM BEGINNING LATER TONIGHT. THERE AREA SOME INDICATIONS THAT LOW LEVEL MOISTURE WILL DEVELOP AS THE COOLER AIR BEGINS TO FILTER INTO THE AREA AS WEAK LOW PRESSURE MOVES TO OUR SE THURSDAY MORNING. AT THIS POINT HAVE NOT FORECAST LOWER THAN MVFR RESTRICTIONS BEGINNING LATER TONIGHT. THERE ARE SOME INDICATIONS THAT IFR OR POSSIBLY LIFR CONDITIONS COULD BE OBSERVED. THIS WILL NEED TO BE MONITORED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 220 PM EDT WED APR 18 2007 .AVIATION /18Z-18Z/... LOW LEVEL FORCING HELPING TO INITIATE/MAINTAIN WEAK CONVECTION THAT EXTENDS INTO THE SW PART OF THE ILN FORECAST AREA AS INDICATED BY LATEST 88D IMAGERY. RUC/NAM MODELS SHOWING LOW LEVEL CONVERGENCE PERSISTING ACROSS OUR SW SECTIONS INTO EARLY THURSDAY MORNING. THE BEST CHANCE FOR PRECIP WILL BE ACROSS THE SW TAF SITES AS THIS LOW-LEVEL FORCING COMBINES WITH MID-LEVEL FORCING IN ASSOCIATION WITH THE CLOSED 50H LOW DROPPING SOUTH ACROSS IN. INSTABILITY EXPECTED TO BE WEAK AND LIMITED TO THE EXTREME SW PART OF OUR FORECAST AREA. AT THIS POINT...ONLY CB HAS BEEN INSERTED IN BOTH THE KCVG AND KLUK TAFS FOR 21Z TO 01Z. OTHER THAN THE PRECIP...THE POTENTIAL FOR LOW CIGS WILL BE A PROBLEM BEGINNING LATER TONIGHT. THERE AREA SOME INDICATIONS THAT LOW LEVEL MOISTURE WILL DEVELOP AS THE COOLER AIR BEGINS TO FILTER INTO THE AREA AS WEAK LOW PRESSURE MOVES TO OUR SE THURSDAY MORNING. AT THIS POINT HAVE NOT FORECAST LOWER THAN MVFR RESTRICTIONS BEGINNING LATER TONIGHT. THERE ARE SOME INDICATIONS THAT IFR OR POSSIBLY LIFR CONDITIONS COULD BE OBSERVED. THIS WILL NEED TO BE MONITORED. && .PREV DISCUSSION... /ISSUED 1208 PM EDT WED APR 18 2007/ SHORT TERM /REST OF TODAY/... LATEST ILN 88D IMAGERY SHOWING VERY WEAK ECHO RETURNS ACROSS THE SOUTHERN PART OF THE FORECAST AREA...WITH A WEAKENING TREND. APPEARS THAT AN W-E AXIS OF WEAK 70H CONVERGENCE HELPING TO TRIGGER THIS CONVECTION. AT BEST...THIS CONVECTION INITIATING ONLY SPRINKLES. HAVE LOWERED POPS ACROSS ENTIRE CWA GIVEN THE CURRENT TRENDS. BEST CHC FOR PRECIP TODAY WILL BE MID TO LATE AFTERNOON ACROSS THE SW PART OF THE FORECAST AREA...AS LOW-LEVEL CONVERGENCE ALONG WITH AFFECTS OF MID-LEVEL FORCING BECOME MORE EVIDENT. ISOLATED T-STORMS ALSO POSSIBLE ACROSS SW PARTS OF THE FA AS BOUNDARY LAYER INSTABILITY INCREASES TO ABOUT 300 J/KG...AND MAINLY RESTRICTED TO SOUTH OF THE OH RIVER. SKY CONDITIONS ALSO UPDATED AS DEEPER DVV AIDING IN SUPPRESSING CLOUDS ACROSS CENTRAL PART OF FORECAST AREA. PREV DISCUSSION... /ISSUED 734 AM EDT WED APR 18 2007/ AVIATION /12Z-12Z/... CURRENT RADAR LOOP SHOWS BAND OF RAIN OVER SOUTHERN KENTUCKY MOVING TO THE EAST. THIS AREA OF PRECIPITATION WILL MOVE E AND WEAKEN OVER THE NEXT 6 HOURS. WATER VAPOR DEPICTS A WELL DEFINE MID-LEVEL CYCLONE DROPPING SOUTH SOUTHEAST WITH CENTER OVER NORTHEAST ILLINOIS THIS MORNING. THIS LOW WILL MOVE SOUTHEAST AND SLOW AS IT MOVES INTO SOUTHERN INDIANA. THIS LOW WILL INCREASE LIGHT PRECIPITATION OVER THE OVER THE TERMINALS LATE THIS AFTERNOON AND TONIGHT. BEST CHANCE FOR LIGHT RAIN AND SHOWERS WILL BE OVER THE KCVG AND KLUK TERMINALS EARLY TONIGHT AND OVER KDAY AND KILN TONIGHT. ONLY ISOLATED SHOWERS EXPECTED VICINITY KCMH AND KLUK LATE TONIGHT. CONDITIONS WILL BE FAVORABLE FOR MVFR CEILINGS TO DEVELOP ACROSS THE AREA TONIGHT AND LOWER TO IFR KDAY AND KILN TOWARDS THE END OF THE FORECAST PERIOD. WHILE IFR CONDITIONS COULD ALSO DEVELOP OVER KCVG AND KLUK FOR THE SAME TIME PERIOD...NOT CONFIDENT ENOUGH TO INTRODUCE INTO THE FORECAST AT THE CURRENT TIME. KCVG WINDS A LITTLE TRICKY THIS MORNING AS MOST GUIDANCE IS FOR A NORTHEAST WIND THROUGHOUT THE PERIOD. SINCE CURRENT WIND IS EAST TO SOUTHEAST FORECASTED WILL REFLECT THESE CONDITIONS FOR MUCH OF THE MORNING HOURS BEFORE BECOMING NORTHEAST THIS AFTERNOON. SPEED SHOULD BE BETWEEN 7 AND 12 KNOTS. PREV DISCUSSION... /ISSUED 321 AM EDT WED APR 18 2007/ SHORT TERM /TODAY THROUGH FRIDAY/... UPPER LOW IS QUITE EVIDENT ON WV IMAGERY...ROTATING SOUTHWARD ACROSS THE WESTERN GREAT LAKES AS IT BEGINS TO CLOSE OFF. AT THE SAME TIME...NUMEROUS MID AND HIGH CLOUDS ARE OVERSPREADING THE AREA IN ADVANCE OF A CLOSED UPPER LOW PROGRESSING EASTWARD ACROSS THE SOUTH CENTRAL U.S. THE LATTER SYSTEM WILL GRADUALLY FILL AND BECOME ABSORBED BY A DEEP LOW OVER THE ERN ATLANTIC...WITH ITS MAIN IMPACT TO THE ILN CWA BEING A STEADY STREAM OF HIGH CLOUDS ESPECIALLY THIS MORNING. GREAT LAKES LOW SLIGHTLY DEEPENS AS IT CONTINUES ITS SOUTHWARD PROGRESSION INTO THE OHIO VALLEY. STILL EXPECTING SCATTERED SHOWERS TO DEVELOP AHEAD OF THIS FEATURE THIS AFTERNOON...ESPECIALLY ACROSS THE WESTERN THIRD OF THE CWA IN CLOSER PROXIMITY TO STRONGEST PVA. FORECAST SOUNDINGS ACROSS SE INDIANA AND NORTHERN KY STILL SHOW WEAK INSTABILITY THIS AFTERNOON...SO MAINTAINED SLIGHT CHANCE OF THUNDER ACROSS THE FAR SOUTHWEST. INSTABILITY LOOKS TOO SHALLOW ELSEWHERE. EXPECT SCATTERED SHOWERS TO CONTINUE OVERNIGHT...ESPECIALLY ACROSS THE SOUTH AS UPPER LOW MOVES INTO ERN KY. LOWERED POPS ACROSS THE NORTH AS I EXPECT NVA TO LIMIT ANY PRECIP POTENTIAL UP THERE. SHALLOW INSTABILITY RETURNS TO OUR SOUTHERN CWA ON THURSDAY THOUGH BEST LIFT EXITS TO THE SOUTHEAST. MAINTAINED SLIGHT CHANCE POPS THROUGH THE DAY ACROSS THE SOUTH AND WENT DRY ELSEWHERE BY AFTERNOON. FRIDAY WILL MARK THE BEGINNING OF A GRADUAL WARM UP AS STRONG H5 RIDGE BUILDS ACROSS THE CENTRAL U.S. TEMPERATURE WISE...FELT MET GUIDANCE WAS TOO WARM TODAY WITH THICKER CLOUDS COMING IN...WHILE MAV SEEMED BIASED ON THE COOL SIDE WITH PRECIP-INDUCED COLD POOL OVER OHIO. WENT FOR A MAV/MET BLEND FOR HIGHS TODAY...TRENDING TOWARD THE WARMER MET LATER IN THE FORECAST PERIOD. HAWBLITZEL PREV DISCUSSION... /ISSUED 334 PM EDT TUE APR 17 2007/ LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... IT APPEARS THAT HIGH PRESSURE AND H5 RIDGING WILL BUILD AND MOVE ACROSS THE AREA FRIDAY THROUGH SUNDAY. DRY WEATHER IS EXPECTED WITH PROGRESSIVELY WARMING TEMPERATURES IN THE 60S AND 70S. THERE IS MUCH UNCERTAINTY...BUT SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE MONDAY INTO TUESDAY AS A COUPLE OF SYSTEMS DEVELOP AND MOVE ACROSS THE REGION. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL. PREV DISCUSSION... /ISSUED 311 AM EDT WED APR 17 2007/ AVIATION /06Z-06Z/... LATEST SATELLITE IMAGERY SHOWS MID CLOUDS INCREASING FROM THE NORTH AND NORTHWEST AND HIGH CLOUDS INCREASING FROM THE SOUTHWEST. LATEST RADAR LOOPS SHOW LIGHT SHOWERS OVER WESTERN AND SOUTH CENTRAL KENTUCKY MOVING SLOWLY TO THE EAST. NEWEST NUMERICAL GUIDANCE SUGGESTS BEST CHANCE FOR SHOWER WILL BE GEARED MORE TO THE AFTERNOON AND EVENING HOURS AND SHOULD NOT BE ASSOCIATED WITH ANY FOCUS LIFTING. THUS VCSH HAVE BEEN REMOVED FROM THE MORNING SECTION OF THE TAFS. ALSO CANNOT COMPLETELY RULE OUT A RISK OF THUNDER MAINLY IN THE KCVG AND KLUK TERMINALS BUT NOT CONFIDENT ENOUGH TO INCLUDE IN TAFS AT THIS TIME. CONDITIONS TO REMAIN VFR THROUGHOUT. WINDS WILL REMAIN EAST TO NORTHEAST AT 10 KNOTS OR LESS THROUGHOUT THE PERIOD. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 130 AM CDT WED APR 18 2007 .DISCUSSION...A WEAK COLD FRONT IS HANGING BACK OVER SOUTH CENTRAL TEXAS THIS MORNING...WITH LITTLE FORCING BEHIND IT. THE ASSOCIATED H5 S/W TROUGH/LOW IS OVER THE RED RIVER BETWEEN OKLAHOMA AND TEXAS AND WILL CONTINUE EAST TODAY WHILE H5 RIDGING WILL BUILD IN ACROSS THE AREA. MOSTLY CLEAR SKIES WILL PREVAIL THE NEXT COUPLE OF DAYS...WITH NEAR NORMAL TEMPERATURES FOR MUCH OF THE FORECAST. BY THURSDAY...CLOUDINESS WILL BEGIN TO INCREASE AS A MODERATE ONSHORE WIND DEVELOPS AS A RESULT OF HIGH PRESSURE OVER THE NORTHWEST GULF OF MEXICO. THE QUIET CONDITIONS WILL CONTINUE AS DEEP SOUTH TEXAS LIES UNDER H5 RIDGING LATE THIS WEEK. AN H5 S/W TROUGH WILL DIG INTO THE FOUR CORNERS REGION ON SATURDAY...AND THIS UPSTREAM INSTABILITY MAY SPARK A SHOWER OR TWO ACROSS THE SOUTH TEXAS AREA...BUT THERE WILL BE NOTHING DEFINITE FOR DEEP SOUTH TEXAS. A FRONT WILL PUSH INTO CENTRAL TEXAS FROM THE NORTH LATE IN THE WEEKEND...BUT IT WILL BE TOO WEAK TO PUSH MUCH CLOSER TO THE LOCAL AREA. SHOWERS TO THE NORTH AND WEST ARE POSSIBLE NEXT MONDAY AS THE NEXT STORM SYSTEM BREWS NEAR THE FOUR CORNERS...WITH INSTABILITY MOVING OVERHEAD. THE UPPER VALLEY HAS A SHOT AT SOME SHOWERS MOVING INTO THAT AREA FROM UPSTREAM LATE MONDAY. BY NEXT TUESDAY THE MID LEVEL FEATURE DRAWS MUCH CLOSER...NEW MEXICO...AND SHOWERS ARE AGAIN POSSIBLE UPSTREAM AS INSTABILITY INCREASES ALOFT. A FRONT FINALLY PUSHES THROUGH NEXT WEDNESDAY AS THE TROUGH AXIS EXTENDS SOUTHWEST OVER DEEP SOUTH TEXAS AND H5 RIDGING AMPLIFIES UPSTREAM. THIS FRONT HAS THE POTENTIAL TO DEVELOP SOME STRONGER STORMS WITH LOCALLY HEAVY RAIN POTENTIAL BECAUSE IT MAY HAVE SOME MID LEVEL SUPPORT AND IT WILL OF COURSE HAVE THE EVER PRESENT GULF MOISTURE TO WORK WITH AS IT APPROACHES THE COAST. && .PREV DISCUSSION...ISSUED AT 810 PM CDT TUE APR 17 2007...SURFACE OBS SHOW THE FRONT CURRENTLY WEST OF COT AND LRD. THIS PUTS THE FRONT WEST OF ITS PREDICTED LOCATION BY THE 18Z NAM/GFS MODEL DATA. HAVE DONE SOME MINOR GRID EDITING TO REFLECT THE SLOWER MOVEMENT OF THE FRONT USING 21Z RUC DATA...WHICH IS MORE IN LINE WITH THE CURRENT POSITION OF THE FRONT. THE FRONT IS EXPECTED TO REACH THE LOWER VALLEY BY AROUND MID-MORNING AND WILL BE MARKED WITH DRIER AIR ALONG WITH A WIND SHIFT TO THE NORTHWEST. DRY AND WARM WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK AS A RIDGE BUILDS OVER THE CENTRAL PORTION OF THE U.S. && .MARINE...BUOY 42019 REPORTED SOUTH WINDS NEAR 14 KNOTS GUSTING TO NEAR 16 KNOTS WITH SEAS SLIGHTLY OVER 4.5 FEET WITH A PERIOD OF 6 SECONDS AT 24 CDT/05 UTC. MODERATE WINDS AND SEAS ARE EXPECTED FOR TODAY THROUGH TONIGHT AS A WEAK COLD FRONT PASSES THROUGH THE LOWER TEXAS COAST. LIGHT WINDS AND LOW SEAS WILL PREVAIL THURSDAY THROUGH THURSDAY NIGHT AS WEAK LOW PRESSURE DEVELOPS OVER DEEP SOUTH TEXAS. MODERATE WINDS AND SEAS WILL RETURN FOR FRIDAY AND THE WEEKEND AS HIGH PRESSURE OVER THE GULF OF MEXICO INTERACTS WITH LOW PRESSURE OVER NORTHEAST MEXICO. && .AVIATION...LOW-LEVEL WIND SHEAR WILL BE THE MAIN AVIATION CONCERN THIS MORNING AS CALM SURFACE WINDS AND WINDS AROUND 30 KNOTS AT 1000 FEET ABOVE THE SURFACE PREVAIL. MODERATE SHIFTING WINDS AND CLEAR SKIES WILL THEN PREVAIL AFTER SUNRISE THROUGH TONIGHT DUE TO THE PASSAGE OF A WEAK COLD FRONT THROUGH DEEP SOUTH TEXAS. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW 83 65 81 68 83 70 / 00 00 00 00 00 00 BROWNSVILLE 85 64 82 67 84 69 / 00 00 00 00 00 00 FALFURRIAS 91 62 86 67 85 67 / 00 00 00 00 00 00 HARLINGEN 89 64 87 66 86 68 / 00 00 00 00 00 00 HEBBRONVILLE 89 62 86 66 87 65 / 00 00 00 00 00 00 MCALLEN 92 66 89 68 87 70 / 00 00 00 00 00 00 PORT ISABEL 82 66 81 69 82 70 / 00 00 00 00 00 00 RIO GRANDE CITY 94 66 90 69 90 71 / 00 00 00 00 00 00 SOUTH PADRE ISLAND 80 67 80 70 81 71 / 00 00 00 00 00 00 && .BRO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 54/66 THIS PRODUCT IS ALSO AVAILABLE ON OUR WEB SITE AT: HTTP://WWW.WEATHER.GOV/BROWNSVILLE tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 354 AM CDT THU APR 19 2007 .DISCUSSION...FCST FOCUS IS ON CLOUD TRENDS TODAY...WARMING TREND INTO WEEKEND AND THEN PCPN CHCS LATE IN WEEKEND INTO MONDAY. WATER VAPOR/RUC SHOWS IMPRESSIVE CIRCULATION CENTER ACRS SRN INDIANA. THIS PROGGD TO SHIFT SEWD FURTHER AWAY FROM CWA TODAY. MID LEVEL RDGING WILL NUDGE CLOSER TO US LATER TODAY. 11/3 ANIMATION SHOWS DECENT SLUG OF OF CLRG WORKING ACRS LAKE MI. EXPECT PC/PS SKIES TO EMERGE FOR ENTIRE CWA WITH WRN CWA LOOKING TO BE THE LAST TO GET IN ON THE SUN. THOUGHT ABOUT ADDING SOME PATCHY FOG FOR TNGT...PSBLY FRI NGT TOO. WINDS THROUGHOUT LOW 1000-850MB COLUMN STILL SHOWING SOME DOUBLE DIGITS KNOTS INTO THE POST-MIDNIGHT HOURS...BUT BECOMING LIGHTER TOWARDS MORNING. ALSO ALL MOS DATA SHOWING 4-7 DEGREE DEW POINT DEPRESSIONS AND LLVL RH PROGS UNIMPRESSIVE SO THIS LENDS TO CONFIDENCE IN HOLDING OFF OF MENTION FOR NOW. THE MAIN STORY FOR FRIDAY AND SATURDAY WILL BE THE BUILDING UPPER RIDGE AND A PRETTY GOOD WARMUP. H8 TEMPS RISE FROM 3C TODAY TO 5C FRIDAY AND THEN NEAR 12C SATURDAY AND SUNDAY. EACH DAY THROUGH SUNDAY LOOKS TO SEE PROGRESSIVELY LESS INFLUENCE OF LAKE MI ON TEMPS. CONSENSUS AND CONTINUTY OF MODELS SUPPORTS HIGHEST POPS FOR SUNDAY NIGHT SO WILL BUMP TO LIKELY CATEGORY FOR THAT TIME FRAME. MODELS ARE ALSO CONTINUING THE TREND OF A SLOWER ONSET OF PCPN SUNDAY SO PULLED BACK POPS FOR THE DAY PORTION. WILL ALSO LINGER SOME SHOWERS INTO MONDAY AS TROUGH AXIS STILL TO OUR WEST. && 10 .AVIATION...WEAK LOW LEVEL CONVERGENCE CONTINUES TO WEAKEN AND SUCCUMB TO INCREASING SUBSIDENCE AND RIDGING TODAY. LATEST 11-3.9 MICRON IMAGERY SHOWING BACK EDGE OF LOW CLOUDS PUSHING ACROSS WESTERN HALF OF LAKE MICHIGAN...HOWEVER CLEARING WL BEGIN TO SLOW AS IT PUSHES CLOSER...AT LEAST FOR A TIME. WILL IMPROVE IFR CONDITIONS AT BOTH KMSN AND KMKE TO VFR DURING THE MRNG WITH PERHAPS KMKE LAGGING SLIGHTLY. BOUNDARY LAYER WINDS WEAKEN TONIGHT AND WITH LACK OF SIGNIFICANT LOW LEVEL DRYING...LIKELY TO BE PATCHY FOG... ESPECIALLY IN EAST. TO EARLY TO TELL HOW LOW VISIBILITIES WILL BE AT THIS POINT PENDING AMOUNT OF DRYING IN LOW LEVELS. && .MKX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 408 AM CDT WED APR 18 2007 .DISCUSSION...FCST FOCUS IS ON PCPN CHCS WITH UPPER LOW DROPPING SWD THRU WRN GRT LAKES TODAY/TNGT. WATER VAPOR/RUC SHOWS UPPER LOW/28 UNIT VORT CENTER VCNTY CNTRL LAKE MI. THIS FEATURE IS PROGGD TO PIVOT SWD INTO INDIANA TODAY...WHICH STILL LEAVES CWA LOCKED IN AN UPPER CYCLONIC FLOW REGIME. WHILE COLUMN INITIALLY DRY IN THE LOW LAYERS...BUFKIT SOUNDINGS SHOW BETTER LOW LEVEL MOISTENING THIS AFTN INTO TNGT. 88D FROM GRB SHOWS SOME PCPN OVER LAKE MI AND NRN LWR MI SHIFTING SWWD WITH TIME. GFS SEEMS TO HAVE BEST HANDLE ON THIS AND SPREADS SOME LIGHT QPF INTO THE CWA TODAY. EVEN THO BEST VORTICITY SLIDES SE OF THE AREA THIS MRNG...THERE ARE SOME INDICATIONS ON THE GFS OF A SECORNDARY WAVE COMING NE TO SW ARND THE CIRCULATION CENTER. THERE IS ALSO EVIDENCE OF AN INVERTED TROF AXIS AT H8 ON BOTH THE GFS AND NAM. SFC THRU H8 FLOW TO BE BRISK FROM THE NE TODAY WHICH ALONG WITH THE CLOUD COVER WILL CERTAINLY MAKE FOR RATHER COOL CONDITIONS. LOWEST LEVELS PROGGD TO REMAIN MOIST TNGT WITH SOME WEAK LIFT...LOOKS LIKE A DRIZZLE SOUNDING OFF THE NAM BUFKIT...BUT WILL JUST GO PATCHY FOR NOW. STILL LOOKS FAIRLY MOIST IN THE LOW LAYERS ON THU MRNG THEN DRYING NOTED ON THE SOUNDINGS AND ON LOW LEVEL RH PROGS. MOS HINTING AT SOME BREAKS DURG THE AFTN. UPPER RIDGING AND SURFACE RIDGING WILL DOMINATE FRI. ON SATURDAY THE UPPER RIDGE WILL BE OVER THE AREA WHILE THE SFC AND H8 RDG SLIP TO THE EAST. WARMER H8 TEMPS WILL ADVECT INTO THE AREA ON INCREASING SRLY WINDS. STILL LOOKS LIKE BEST DYNAMICS AND SUBSEQUENT POPS ENCROACH FOR LATER SUN INTO SUN NGT. && 10 .AVIATION...EXPECT SECONDARY WEAK SHORT WAVE TROUGH ROTATING AROUND AMPLIFYING UPPER LOW TO RETURN VFR CIGS TO MOST OF SRN WI LATER THIS MORNING. INCRG LOW LEVEL COLD AIR ADVECTION AND RELATIVELY MOIST LOW LEVEL FLOW UPSTREAM...WOULD EXPECT MVFR CIGS TO EVENTUALLY DEVELOP AT KMKE THIS AFTN OR EVE AND PERSIST THROUGH TNGT. LIGHT FOG AND RAIN MAY ALSO RESULT IN SOME VSBY REDUCTIONS AT KMKE. && .MKX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 455 AM CDT FRI APR 20 2007 .DISCUSSION... SHORT TERM CONCERNS FOR TODAY ARE PRECIPITATION CHANCES THIS MORNING OVER THE NORTHERN COUNTIES...AND OVER THE FAR NORTHWEST COUNTIES THIS AFTERNOON. CONCERNS OVERNIGHT ARE AGAIN PRECIPITATION CHANCES OVER THE NORTHWEST COUNTIES. FOR THE WEEKEND...CONCERNS ARE HOW FAST THE PRECIPITATION SPREADS EASTWARD AND SEVERE POTENTIAL. BEYOND THE WEEKEND HAVE CHANCES OF PRECIPITATION AGAIN TUESDAY THROUGH THURSDAY. LATEST WATER VAPOR IMAGERY AND PROFILERS SHOWING SEVERAL LOBES OF UPPER ENERGY OVER THE WESTERN CONUS AND COMING INTO THE WEST COAST...WITH RIDGING OVER THE MID MISSISSIPPI VALLEY SLIDING SLOWLY SOUTHEAST. SURFACE PATTERN HAD LOW PRESSURE OVER THE HIGH PLAINS WITH FRONTAL BOUNDARY/DRY LINE FROM WESTERN PORTIONS OF NEBRASKA INTO SOUTHEAST COLORADO. INCREASING SOUTHERLY FLOW HAS DRAWN A CHANNEL OF 50 DEWPOINTS NORTHWARD ACROSS CENTRAL KANSAS WITH MID 50 DEWPOINTS ENTERING SOUTH CENTRAL PORTIONS OF THE STATE. SURFACE TEMPERATURES WERE IN THE LOWER TO MID 50S. IN THE CORE OF DEEPER MOISTURE AND WITH THE AID OF THE TAIL END OF SOME SHORTWAVE ENERGY ROTATING AROUND NORTHERN UPPER LOW OVER MONTANA...AND WARM ADVECTION...ISOLATED THUNDERSTORMS DEVELOP OVER PARTS OF NORTHWEST AND NORTH CENTRAL KANSAS DURING THURSDAY EVENING...MOVING TO THE NORTHEAST. ACTIVITY DIMINISHED AFTER MIDNIGHT BUT MID LEVEL CLOUD BAND LINGERS. THE EVENING RUC MODEL SHOWED SOME QPF POTENTIAL OVER THE NORTHERN COUNTIES INTO THE MORNING HOURS AND THE 00Z NAM HAD SOME SPOTTY QPF AS WELL...AND WITH THE MID CLOUDS AROUND...LEFT SOME SLIGHT CHANCE POPS NORTHCENTRAL AND FAR NORTHERN COUNTIES THIS MORNING. OTHERWISE...EXPECTING BREEZY CONDITIONS WITH HIGHS TEMPERATURES REACHING THE MID 70S MOST AREAS TODAY AND PARTLY TO MOSTLY SUNNY SKIES. WITH THE NAM SOUNDINGS SHOWING LITTLE IN THE WAY OF CAP AND IN THE VICINITY OF MOISTURE CONVERGENCE...HAVE LEFT SOME LOW CHANCE POPS OVER THE NORTH CENTRAL COUNTIES LATE THIS AFTERNOON AND CONTINUED DURING THE NIGHT TIME HOURS A COUNTY OR SO FURTHER EAST. LOWS TONIGHT IN THE MIDDLE 50S WITH WINDS AND INCREASING CLOUDS HELPING KEEP READINGS MILD. MODELS STILL SLOWING THE MOVEMENT OF THE SOUTHWEST UPPER LOW FOR THE WEEKEND WEATHER. AHEAD OF THIS FEATURE...SURFACE LOW DEEPENS OVER THE HIGH PLAINS...KEEPING IT WINDY WHILE DRAWING MOISTURE NORTH AND WESTWARD. UPPER DYNAMICS AND FOCUS FOR ACTIVITY ALONG THE DRY LINE FAVOR THE HIGH PLAINS SATURDAY AFTERNOON WITH ACTIVITY GRADUALLY MOVING EASTWARD SATURDAY NIGHT. NAM IS MUCH SLOWER IN PUSHING THE PRECIPITATION CHANCES EAST AND FOR NOW FAVORING THE BIT MORE PROGRESSIVE GFS AS SYSTEM NOW APPROACHING PACIFIC NORTHWEST ACTS AS KICKER WHEN IT DIVES SOUTH. INCREASED THE WESTERN PORTIONS OF CWA INTO THE "LIKELY" RAIN CHANCE CATEGORY SATURDAY NIGHT....THEN SPREAD THAT TO THE EAST ON SUNDAY. THUNDERSTORMS COULD BE SEVERE OVER THE WESTERN COUNTIES ESPECIALLY INTO THE EARLY NIGHTTIME HOURS SATURDAY. HIGHS SATURDAY IN THE UPPER 70S MOST AREAS...LOWS SATURDAY NIGHT AGAIN MILD...IN THE MIDDLE 50S. ON SUNDAY...UPPER WAVE EJECTS NORTHEAST ACROSS THE CWA WITH BEST PRECIPITATION CHANCES MORNING INTO MID AFTERNOON ON THE GFS...THE NAM A BIT SLOWER. AGAIN GIVEN THE SHEAR AND INSTABILITY...SOME POTENTIAL FOR SEVERE BUT WILL DEPEND ON EXTENT OF SATURDAY NIGHT CONVECTION. WITH CLOUD COVER AND PRECIPITATION...HIGHS SUNDAY IN THE LOWER TO MIDDLE 70S. HAVE COMPROMISED ON GFS/NAM MOVEMENT THUS LEFT SOME LOW CHANCE POPS FOR SUNDAY EVENING...THE GFS WOULD HAVE PRECIP EXITING THE AREA BY 00Z MON. ONLY SOME MINOR BLENDING CHANGES TO GOING FORECAST BEYOND SUNDAY NIGHT. FRONTAL BOUNDARY TO THE SOUTH GIVES SOME POTENTIAL FOR THUNDERSTORMS OVER THE SOUTHERN COUNTIES ON MONDAY. NEXT WAVE ENTERS THE AREA MONDAY AND BECOMES A SLOW MOVER IN THE SOUTHERN STREAM GIVING A PROLONGED PERIOD OF PRECIPITATION CHANCES TUESDAY INTO WEDNESDAY. HIGH TEMPERATURES MONDAY AND TUESDAY MAINLY IN THE LOWER TO MID 70S...COOLING INTO THE MID TO UPPER 60S FOR WEDNESDAY AND THURSDAY...LOWS MAINLY IN THE RANGE OF THE UPPER 40S TO LOWER 50S. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PF ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 200 AM MDT FRI APR 20 2007 .DISCUSSION...FORECAST CONCERNS REMAIN ON SEVERE THUNDERSTORM POTENTIAL TODAY AND ESPECIALLY SATURDAY AS AN OUTBREAK IS POSSIBLE. HEAVY RAIN AND THE THREAT FOR LOCALIZED FLOODING WILL INCREASE SATURDAY NIGHT. .SHORT TERM (TODAY-SUNDAY NIGHT) TODAY/TONIGHT...SOUTHEASTERLY SFC WINDS WILL INCREASE INTO THE BREEZY TO WINDY CATEGORY THIS AFTERNOON AND INTO THE OVERNIGHT HOURS AS LOW PRESSURE DEVELOPS ALONG THE LEE SIDE OF THE ROCKIES AHEAD OF AN UPPER LEVEL LOW PRESSURE AREA WHICH BY 12Z SATURDAY SHOULD BE NEAR SW ARIZONA. STRATUS WILL AGAIN BE A PROBLEM THROUGH LATE MORNING BEFORE BURNING OFF DURING THE AFTERNOON HOURS. THIS WILL INITIALLY DAMPEN THE STANDARD DIURNAL CURVE BUT SHOULDNT EFFECT OVERALL TEMPERATURES WHICH SHOULD PUSH INTO THE MID 70S. STILL LOOKS LIKE A SLIGHT CHANCE OF THUNDERSTORMS IS WARRANTED ACROSS MOST OF THE FORECAST AREA BY MID TO LATE AFTERNOON ALONG A SURFACE TROUGH. EXACT POSITION OF THE TROUGH VARIES BETWEEN THE NAM/GFS/RUC13 SO SOMEWHAT BROADBRUSHED THE SLIGHT CHANCE POPS FOR NOW. SOME STRATUS RETURNS TO THE AREA AGAIN OVERNIGHT AS BOUNDARY LAYER MOISTURE INCREASES. RUC AND NAM SUGGEST THAT ANY ACTIVITY THAT DEVELOPS DURING THE LATE AFTERNOON HOURS WILL CONTINUE OR SLIGHTLY INCREASE IN COVERAGE THROUGH MIDNIGHT AS LOW LEVEL JET DEVELOPS. AROUND OR SHORTLY AFTER MIDNIGHT ANY PRECIP THAT DEVELOPS SHOULD HAVE QUICKLY MOVED NORTHEAST OF THE AREA. SATURDAY/SATURDAY NIGHT...WILL MAINTAIN HIGHEST POPS ACROSS THOSE COUNTIES EITHER SIDE OF THE CO/KS BORDER FOR THE AFTERNOON HOURS AS UPPER LOW REACHES CENTRAL NEW MEXICO. HAVE TRENDED TOWARD THE GFS AT THIS POINT FOR PLACEMENT OF HIGHEST POPS AS USED HPC QPF. WILL CONTINUE WITH SEVERE WORDING AS WELL. FOR SATURDAY NIGHT ALL MODELS EXCEPT THE GFS ARE IN GREAT AGREEMENT BRINGING THE UPPER LOW ATOP THE AREA BY 12Z SUNDAY. THE GFS IS ABOUT 6 HOURS FASTER. WILL GO WITH THE CONSENSUS AND KEEP HIGHEST POPS GENERALLY EAST OF THE CO/KS BORDER. HEAVY RAIN AND FLOODING REMAIN A THREAT AS STORMS REMAIN PARALLEL TO THE UPPER FLOW. HIGHS SATURDAY 70-75. SUNDAY/SUNDAY NIGHT...WRAPAROUND SHOWERS WILL LIFT NORTHEAST AND OUT OF THE AREA BY MID AFTERNOON ALONG WITH THE UPPER LOW. WILL NEED TO WATCH FOR FOG FORMATION SUNDAY NIGHT AS SOUTHEASTERLY WINDS DEVELOP AND GROUND SATURATED FROM THE EXPECTED RECENT RAINS. OTHER FEATURES OF INTEREST WILL BE ANOTHER LOW PRESSURE CENTER WHICH BY 12Z MONDAY SHOULD BE NEAR SOUTHWEST UTAH...DIVING SOUTHEAST. CURRENTLY EXPECT HIGHS IN THE MID TO UPPER 60S. IF THE PRECIP MOVES OUT FASTER THEN TEMPERATURES COULD BE A BIT WARMER THEN CURRENTLY EXPECTED. IF ITS SLOWER THEN WILL NEED TO TREND DOWNWARD. .LONG TERM (MONDAY-THURSDAY) NO CHANGES MADE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ DDT ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 355 AM EDT FRI APR 20 2007 .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE HUDSON BAY HI PRES RDG SANDWICHED BTWN RDG OFF THE E COAST AND ANOTHER OVER THE PAC NW. QUIET NITE OVER THE FA WITH HI PRES RDG AXIS AND DRY STABLE AIRMASS DEPICTED ON THE 00Z GRB RAOB/01Z TAMDAR SDNG FM SAW DOMINATING. SHRTWV OVER THE NRN PLAINS IS ROTATING ALMOST DUE N ON THE ERN FLANK OF NW TROF...SO ASSOCIATED MID/HI CLD MAKING ONLY SLOW PROGRESS EWD THRU MN E TOWARD THE UPR LKS WITH SE TRAJECTORIES MAINTAINING DRY AIRMASS AT INL AS WELL. JUST A BIT HIER RH NOTED ON THE 00Z INL SDNG AT THE TOP OF THE PBL...BUT ASSOCIATED DIURNAL CU DSPTD SOON AFT SUNSET. ANOTHER MORE POTENT SHRTWV DROPPING THRU WRN TROF TOWARD THE SW CONUS. MAIN FCST CONCERNS INTO SAT ARE TEMPS/FIRE WX ISSUES WITH DRY RDG PROGGED TO REMAIN DOMINANT. AS RDG BREAKS DOWN OVER THE WEEKEND AND SHRTWV NOW MOVING TOWARD THE SW CONUS LIFTS TO THE NE...FOCUS WL SHIFT TOWARD TIMING ARRIVAL OF ANY ASSOCIATED PCPN. EXPECT ANOTHER QUIET DAY OVER THE FA TDAY UNDER SFC RDG. CENTER OF SFC HI PRES PROGGED TO SHIFT OVER THE CNTRL GRT LKS UNDER RISING UPR HGTS...SO LLVL FLOW WL SHIFT TO MORE SLY...ESPECIALLY OVER THE WRN ZNS. WITH REDUCED LK MODERATION AND H85 TEMPS PROGGED TO RISE TO 6C OVER THE W BY 00Z SAT...EXPECT HI TEMPS OVER THE WCNTRL INTERIOR TO REACH APRCH 70 PER MIXING TO H8 ON GFS/NAM FCST SDNGS. OTHER THAN SOME DIURNAL CU AND SOME HI CLD OVER THE W ASSOCIATED WITH NRN PLAINS TROF LIFTING N INTO CAN...SKIES WL BE SUNNY. MIXING TO H8 WL ALLOW SFC DWPTS TO FALL TOWARD 32 IN THE AFTN...WITH MIN RH FALLING TOWARD 25 PCT. RELATIVELY LGT WINDS WL KEEP OVERALL FIRE WX SITUATION FM BECMG TOO CRITICAL. UPR RDG FCST TO DOMINATE AGAIN TNGT...SO EXPECT A QUIET PD WITH MOCLR SKIES AGAIN. HI PRES CENTER FCST TO MOVE TO NEAR DTX BY 12Z SAT...SO RETURN SW FLOW WL HOLD MIN TEMPS HIER THAN THIS MRNG WITH H925 WINDS 15 TO 20 KT. EXPECT THE LOWEST READINGS OVER THE INTERIOR SCNTRL AND E. SHRTWV NOW MOVING INTO THE SW CONUS FCST TO BEGIN TO ROUND THE BASE OF WRN TROF AND LIFT INTO THE PLAINS ON SAT. WITH FALLING PRES IN THE PLAINS AHEAD OF THIS SYS AND SFC HI PRES RDG MOVING SLOWLY TO THE E...PRES GRADIENT/SSW FLOW FCST TO INCRS OVER THE UPR LKS DURING THE DAY. OPTED TO REMOVE PCPN OVER THE LAND FA ON SAT GIVEN STRENGTH OF RDG/ANTECEDENT DRY AIRMASS...BUT TENDED TO KEEP LO CHC POPS OVER WRN LK SUP AS GFS/UKMET/ECMWF HINT AT A FEW WEAK DISTURBANCES RIDING OVER THE TOP OF THE RDG TO THE NW AND INTERACTING WITH LLVL MSTR RETURN. MIXING TO H8 ON GFS/NAM FCST SDNGS WOULD ALLOW TEMPS TO RISE INTO THE LO 70S AWAY FM MODERATION OFF LK MI. THE NAM AND ESPECIALLY THE GFS SHOW QUITE A BIT MORE LLVL MSTR RETURNING OVER THE W...WITH MIXING TO H8 INDICATING DWPTS WOULD FALL OFF TO ONLY 40 TO 45. THE NAM IS NOT AS AGGRESSIVE WITH LLVL MSTR RETURN...AND MIXING TO H8 WOULD ALLOW THE DWPT TO FALL TO ONLY ABOUT 37 (RH CLOSE TO 25 PERCENT). TEND TO PREFER THE DRIER NAM IDEA AT THIS POINT CONSIDERING THE SLOWER EXPECTED BREAKDOWN OF THE RDG IN PRESENT HI AMPLITUDE PATTERN. COMBINATION OF INCRSG WINDS...MIXING OF FAIRLY DRY AIR...AND TEMPS REACHING AOA 70 AT A FEW PLACES WL PUSH OVERALL FIRE WX PARAMETERS TO NEAR CRITICAL LVLS. GFS/NAM SHOW H925 SW WINDS REACHING 35 TO 40 KTS SAT NGT IN A CAPPED WARM SECTOR...SO EXPECT A RELATIVELY NEGLIGIBLE DIURNAL TEMP DROP. READINGS IN THE DOWNSLOPE AREAS FM P53-MQT-P59-IWD MAY NOT DROP BLO 50. RESTRICTED POPS ON SAT TO OVER LK SUP CONSIDERING CAPPED FCST SDNGS IN WARM SECTOR. SUN WL BE A VERY WARM DAY WITH STRONG SW FLOW CONTINUING AHEAD OF SHRTWV SLOWLY LIFTING NE. CONSIDERING EXPECTED SLOWER APRCH OF SHRTWV AND MORE SUNSHINE COUPLED WITH H85 TEMPS APRCHG 15C...GOING FCST HI TEMPS IN THE MID TO UPR 70S AWAY FM LK MI MODERATION LOOK ON TRACK. PER NCEP GUIDANCE...FOLLOWED THE UKMET/NAM SOLNS MORE THAN THE GFS. THESE MODELS HINT AT MORE LLVL MSTR AND SFC DWPTS IN THE 40 TO 45 RANGE...WHICH WOULD KEEP THE RH IN THE 25 TO 30 PCT RANGE. TRENDED TOWARD THE SLOWER NAM/UKMET/CNDN MODELS ON FCST PROGRESSION OF SYS LIFTING OUT OF THE SW...SO CUT POPS SUN NGT. COORDINATED WITH APX/GRB. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 314 AM CDT FRI APR 20 2007 .DISCUSSION... THUNDERSTORM CHANCES INTO SUNDAY MAIN FORECAST CONCERN. HOW FAST UPPER LOW STILL DIGGING SOUTH ALONG THE WRN CA COAST EJECTS ACROSS THE PLAINS WILL PLAY A LARGE ROLE IN TIMING AND POSSIBLE STORM STRUCTURE. OPERATIONAL MODEL SELECTION SOMEWHAT QUESTIONABLE AS 00Z NAM LACKED CANADIAN UA DATA...ALTHOUGH PROBABLY NOT AS CRITICAL WITH PACIFIC SYSTEM...AND GFS WAS FASTER THAN OTHER OPERATIONAL MODELS PLUS ITS OWN ENSEMBLE MEAN. SHORT TERM...TODAY AND TONIGHT. STLT SHOWED LEAD UPPER LOW LIFTING INTO NERN MT/NWRN ND VCNTY WITH A SHEARED VORT LOBE EXTDG INTO NERN NEBR. POSSIBLY ASSOCD WITH LOBE...ISOLD CONVECTION HAS DEVELOPED IN CLOUD FIELD NW OF LNK/OMA SINCE 0630Z AIDED BY 850 MB THETA E ADVCTN. LATEST RUC SHIFTS THIS ADVCTN NWRD THRU 18Z AS 850 MB WINDS BACK AND STRENGTHEN SLIGHTLY. OTHER CLOUD ELEMENTS APPEARED CELLULAR IN NATURE VIA STLT OVR WRN IA AND WSW OF LNK. THUS WILL CARRY SMALL POPS MOST ZONES THIS MORNING. APPEARS CLOUDS SHOULD DISPT ENOUGH THIS AFTN TO ALLOW MIXING TO NEAR 850 MB AND GUIDANCE/PREV FORECAST LOOKED GOOD. LEFT IN SMALL AFTN POPS FAR SW. THERE MAY NOT BE ENOUGH TO FOCUS ACTIVITY THERE...BUT IT WL BE ON ERN EDGE OF INSTABILITY AXIS AS MOISTURE BEGINS RETURNING NWRD TWD SOME SORT OF BOUNDARY/DRYLINE THAT WL BE ATTEMPTING TO LIFT NWD ACRS WRN NEBRASKA. FOR TNGT...AS LOW LVL JET STRENGTHENS AND VEERS A BIT OVERNIGHT...850 MB THETA E ADVCTN DVLPS OVR FCST AREA. THUS LEFT IN SMALL POPS ALL BUT FAR SERN ZONES EVEN THOUGH NO OTHER APPARENT FOCUS. WARM AND WINDY CONDITIONS LOOK LIKELY ON SATURDAY AS UPPER LOW APPROACHES. NO BIG CHANGES TO TEMPS/WINDS. FOR SAT NGT/SUNDAY KEPT FORECAST BASED ON A SLOWER EJECTION OF TROUGH/LOW SINCE IT WAS BACKED BY 00Z CANADIAN/ECMWF/NAM AND GFS ENSEMBLE MEAN. THUS DECREASED POPS SLIGHTLY SAT NGT ERN ZONES AS SAT AFTN/EVENING CONVECTION THAT DVLPS SHOULD TEND TO MOVE MORE N THAN E. HOWEVER...PCPN CHCS WILL BE INCREASING SUNDAY AS UPPER LOW OR OPENING UPPER TROUGH LIFTS ACROSS THE CWA. ATTM APPEARS SYSTEM WILL BE COMING ACROSS JUST SLOWLY ENOUGH TO ALLOW DECENT HEATING ERN ZONES ENHANCING SEVERE THREAT BOTH NEAR TRACK OF UPPER SYSTEM AND ALONG TRAILING CDFNT. MADE LTL CHANGES TO REST OF FORECAST. MONDAY APPEARS DRY IN ADVANCE OF NEXT SYSTEM...WHICH COULD POSSIBLY LIFT A WARM FRONT INTO SRN ZONES IF LATEST ECMWF/GFS ARE RIGHT. THUS IF THAT TREND CONTINUES ON LATEST MODEL RUNS...TEMPS MAY NEED TO BE RAISED SOME AREAS ON TUESDAY. WED/THU ARE DEPENDANT ON WHETHER UPPER LOW CUTS OFF TO OUR S OR LIFTS AND STALLS OVER US. TOO MANY UNCERTAINTIES TO MAKE SIGNIFICANT CHANGES THIS MORNING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ CHERMOK ne AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BINGHAMTON NY 120 AM EDT FRI APR 20 2007 .AVIATION /200600Z-210600Z/... VFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD WITH CLEAR OR NEARLY CLEAR SKIES AT ALL SITES. FOG NOT EXPECTED TONIGHT AS DEWPOINT DEPRESSIONS ARE STILL PRETTY HEALTHY AND DEWPOINTS HAVE TRENDED DOWN A LITTLE OVER THE PAST FEW HOURS. LGT/VAR WINDS OVERNIGHT TONIGHT WILL BECOME NORTH-NORTHWESTERLY THIS MORNING AROUND 10KTS AND CONTINUE THROUGH SUNSET...WHEN THEY WILL DIMINISH TO 5KTS OR LESS ONCE AGAIN. AN EXTENDED PERIOD OF VERY GOOD FLYING WEATHER IS IN STORE. && PREV DISCUSSION... /ISSUED 209 PM EDT THU APR 19 2007/ SHORT TERM /TONIGHT THROUGH SUNDAY/... GLOBAL MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH SUNDAY TAKING THE OMEGA BLOCK THAT IS OVER THE CENTRAL PORTION OF THE NORTH AMERICAN CONTINENT AND PUSHING IT EASTWARD. AT THE SAME TIME...THE RIDGE ASSOCIATED WITH THIS BLOCK WILL FLATTEN. WE WILL REMAIN EAST OF THE MID LEVEL/SURFACE RIDGE AXIS THROUGH SATURDAY NIGHT...WITH DRY NORTHERLY FLOW OVER THE CWA. MINOR AMOUNTS OF CLOUD COVER THROUGH THE PERIOD WILL BE GOVERNED BY SOME WEAK MID LEVEL IMPULSES THAT WILL ROTATE THROUGH THE AREA. WITH THE SFC RIDGE NEARING THE AREA BY THE END OF THE WEEKEND...EXPECT TEMPS TO MOVE WELL /10F/ ABOVE SEASONAL NORMS BY THE SATURDAY-SUNDAY TIMEFRAME. THIS EVENING...THE RUC AND NAM PROFILES SUGGEST THE ARRIVAL OF ONE LAST WEAK SHORTWAVE FROM THE EAST AROUND OR JUST AFTER 00Z TONIGHT. NAM/RUC RH PROGS SHOW A LITTLE BIT IN THE WAY OF MID LEVEL MOISTURE ASSOCIATED WITH THIS WAVE...MOSTLY IMPACTING OUR SOUTHEASTERN ZONES. WITH 500 HEIGHTS BUILDING THROUGH THE EVENING...CAN`T SEE THIS WAVE DOING ANYTHING MORE THAN DELAYING THE TRANSITION FROM PCLOUDY TO MCLEAR OVER THE SOUTHERN ZONES THIS EVENING. AFTER THIS WAVE DEPARTS...EXPECT A PROLONGED PERIOD OF DRY WEATHER WITH TEMPERATURES CONTINUING TO CLIMB. MODELS BRING A PRETTY STRONG SHORT WAVE RIDGE THROUGH THE AREA ON FRIDAY...ALLOWING FOR A WONDERFUL DAY. BUFKIT PROFILES ARE QUITE DRY WITH A STRONG SUBSIDENCE INVERSION. GOOD MIXING TO 850 WILL TAP ANY WINDS IN THE LOWER LEVELS AND BRING THEM TO THE SURFACE...BUT THE GRADIENT WON`T BE PARTICULARLY IMPRESSIVE...SO NOTHING MORE THAN 20-25MPH GUSTS ARE EXPECTED. T850 RANGES FROM +4-6C IN THE GUIDANCE...WHICH WOULD GIVE HIGHS IN THE L/MID 60S...AND WE`LL LEAN TOWARDS THE WARMER END BASED ON HOW THE MODELS HAVE BEEN PLAYING CATCH UP WITH THE TEMPS OVER THE PAST FEW DAYS. IT APPEARS WE WILL FINALLY GET A CHANCE TO DRY OUT SOME WITH DEW POINTS REMAINING IN THE U20S/L30S THROUGHOUT THE DAY. TONIGHT...MODELS DROP THE DEWPOINTS RAPIDLY WITH OVER-LAND NORTHEASTERLY FLOW. UPSTREAM OBS FROM OUR CANADIAN NEIGHBORS AND EVEN THOSE OVER NEW ENGLAND INDICATE DEWPOINTS DROPPING INTO THE TEENS. THINK THIS STRONG LLEVEL DRYING WILL HOLD OFF UNTIL OVERNIGHT TONIGHT. THIS SHOULD ALLOW TEMPS TO FALL NICELY TONIGHT...PROBABLY COOLER THAN OVER THE PAST FEW NIGHTS. WILL GENERALLY FOLLOW MET GUIDANCE. THESE DRY READINGS...ALONG WITH A LITTLE BIT OF WIND SHOULD KEEP FOG FROM BEING A PROBLEM. THE DRY WEATHER CONTINUES INTO SATURDAY WITH LITTLE CHANGE. RH PROGS SHOW A LITTLE BIT IN THE WAY OF UPPER LEVEL MOISTENING IN THE AFTERNOON AS A WEAK SHORT WAVE ROTATES TOWARDS THE AREA IN THE NORTHWEST FLOW ALOFT. HOWEVER...THE DAY SHOULD BE SUNNY/MSUNNY AND WITH T850 BETWEEN 5-6C HIGHS AROUND U60S TO AROUND 70 LOOK GOOD. ALTHOUGH DEEP MIXING IS AGAIN EXPECTED...WEAKER GRADIENTS WILL LESSEN THE WINDS EVEN MORE...15MPH OR LESS EVEN IN GUSTS. LLEVEL RHS WILL LIKELY BE A LITTLE HIGHER THAN ON FRIDAY AS BOUNDARY LAYER WIND TRAJECTORIES TAKE MORE OF A TRACK OVER THE LAKES. THIS INCREASED LLEVEL MOISTURE SHOULD HELP KEEP LOWS SATURDAY NIGHT A LITTLE WARMER THAN ON FRIDAY NIGHT...PROBABLY JUST ABOVE FREEZING RATHER THAN AT/JUST BELOW. A LOW PRESSURE SYSTEM WILL MOVE EAST SOUTH OF HUDSON BAY ON SUNDAY AS THE EAST COAST RIDGE BEGINS TO FLATTEN. ALTHOUGH WELL NORTH OF THE CWA...SOME UPPER LEVEL CLOUDINESS MAY FILTER IN FROM THE NORTH. HOWEVER...THE DAY WILL STILL TURN OUT MSUNNY. WITH T850 REACHING 6-7C...U60S/L70S ARE LIKELY FOR HIGHS ACROSS THE CWA. WINDS WILL REMAIN QUITE LIGHT AS THE CREST OF THE SURFACE RIDGE MOVES OVER THE AREA. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... NEXT WEEK WILL START OFF WITH A CONTINUATION OF DRY MILD WEATHER. BY TUESDAY...A COLD FRONT IS EXPECTED TO MOVE ACROSS FROM THE NORTHWEST...ACCOMPANIED BY SOME SHOWERS. AT THIS POINT...THE FRONT LOOKS AS THOUGH IT WILL BE PROGRESSIVE ENOUGH...SO THAT DRIER AND SOMEWHAT COOLER WEATHER SHOULD RETURN FOR WEDNESDAY AND THURSDAY. HYDROLOGY... BAINBRIDGE AND CONKLIN STILL THE PRIMARY SITES OF CONCERN WITH CONKLIN JUST ABOVE FS AND BAINBRIDGE VERY NEAR IT. RIVERS CONTINUE TO BE FED BY SNOWMELT...BUT THIS WILL COME TO AN END SOON. WAVERLY ALSO FORECAST TO COME CLOSE TO FS TOMORROW. HAVE KEPT WARNINGS AS THE ARE ATTM...BUT EXPECT RIVERS TO BEGIN TO FALL ESPECIALLY AS WE MOVE INTO TOMORROW AS THE REMAINING SNOWPACK IS LOST AND WE SEE AN EXTENDED DRY PERIOD. AGAIN...ONLY VERY MINOR FLOODING IS EXPECTED. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...NONE. PA...NONE. && $$ AVIATION...JMA ny AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TOPEKA KS 556 AM CDT FRI APR 20 2007 .DISCUSSION... WITH MID CLOUDS THINNING AND RADAR SHOWING ACTIVITY OFF TO THE FAR NORTH...WILL BE DOING A FORECAST UPDATE TO TAKE OUT MENTION OF PRECIPITATION CHANCES FOR THE NORTHERN AND WESTERN COUNTIES THIS MORNING. LATEST RUC STILL SHOWING SOME QPF POTENTIAL BUT IT WOULD HAVE HAD RAIN ACROSS MUCH OF THE WESTERN PORTIONS OF THE CWA THROUGH THE NIGHT. 06Z NAM HAD SOME SPOTTY QPF FOR THE AM BUT FURTHER WEST OF CWA. LATEST WATER VAPOR NOT GIVING ANY SIGNS FOR UPPER SUPPORT OVER CWA. && PF .PREVIOUS DISCUSSION... 455 AM CDT FRI APR 20 2007 SHORT TERM CONCERNS FOR TODAY ARE PRECIPITATION CHANCES THIS MORNING OVER THE NORTHERN COUNTIES...AND OVER THE FAR NORTHWEST COUNTIES THIS AFTERNOON. CONCERNS OVERNIGHT ARE AGAIN PRECIPITATION CHANCES OVER THE NORTHWEST COUNTIES. FOR THE WEEKEND...CONCERNS ARE HOW FAST THE PRECIPITATION SPREADS EASTWARD AND SEVERE POTENTIAL. BEYOND THE WEEKEND HAVE CHANCES OF PRECIPITATION AGAIN TUESDAY THROUGH THURSDAY. LATEST WATER VAPOR IMAGERY AND PROFILERS SHOWING SEVERAL LOBES OF UPPER ENERGY OVER THE WESTERN CONUS AND COMING INTO THE WEST COAST...WITH RIDGING OVER THE MID MISSISSIPPI VALLEY SLIDING SLOWLY SOUTHEAST. SURFACE PATTERN HAD LOW PRESSURE OVER THE HIGH PLAINS WITH FRONTAL BOUNDARY/DRY LINE FROM WESTERN PORTIONS OF NEBRASKA INTO SOUTHEAST COLORADO. INCREASING SOUTHERLY FLOW HAS DRAWN A CHANNEL OF 50 DEWPOINTS NORTHWARD ACROSS CENTRAL KANSAS WITH MID 50 DEWPOINTS ENTERING SOUTH CENTRAL PORTIONS OF THE STATE. SURFACE TEMPERATURES WERE IN THE LOWER TO MID 50S. IN THE CORE OF DEEPER MOISTURE AND WITH THE AID OF THE TAIL END OF SOME SHORTWAVE ENERGY ROTATING AROUND NORTHERN UPPER LOW OVER MONTANA...AND WARM ADVECTION...ISOLATED THUNDERSTORMS DEVELOP OVER PARTS OF NORTHWEST AND NORTH CENTRAL KANSAS DURING THURSDAY EVENING...MOVING TO THE NORTHEAST. ACTIVITY DIMINISHED AFTER MIDNIGHT BUT MID LEVEL CLOUD BAND LINGERS. THE EVENING RUC MODEL SHOWED SOME QPF POTENTIAL OVER THE NORTHERN COUNTIES INTO THE MORNING HOURS AND THE 00Z NAM HAD SOME SPOTTY QPF AS WELL...AND WITH THE MID CLOUDS AROUND...LEFT SOME SLIGHT CHANCE POPS NORTHCENTRAL AND FAR NORTHERN COUNTIES THIS MORNING. OTHERWISE...EXPECTING BREEZY CONDITIONS WITH HIGHS TEMPERATURES REACHING THE MID 70S MOST AREAS TODAY AND PARTLY TO MOSTLY SUNNY SKIES. WITH THE NAM SOUNDINGS SHOWING LITTLE IN THE WAY OF CAP AND IN THE VICINITY OF MOISTURE CONVERGENCE...HAVE LEFT SOME LOW CHANCE POPS OVER THE NORTH CENTRAL COUNTIES LATE THIS AFTERNOON AND CONTINUED DURING THE NIGHT TIME HOURS A COUNTY OR SO FURTHER EAST. LOWS TONIGHT IN THE MIDDLE 50S WITH WINDS AND INCREASING CLOUDS HELPING KEEP READINGS MILD. MODELS STILL SLOWING THE MOVEMENT OF THE SOUTHWEST UPPER LOW FOR THE WEEKEND WEATHER. AHEAD OF THIS FEATURE...SURFACE LOW DEEPENS OVER THE HIGH PLAINS...KEEPING IT WINDY WHILE DRAWING MOISTURE NORTH AND WESTWARD. UPPER DYNAMICS AND FOCUS FOR ACTIVITY ALONG THE DRY LINE FAVOR THE HIGH PLAINS SATURDAY AFTERNOON WITH ACTIVITY GRADUALLY MOVING EASTWARD SATURDAY NIGHT. NAM IS MUCH SLOWER IN PUSHING THE PRECIPITATION CHANCES EAST AND FOR NOW FAVORING THE BIT MORE PROGRESSIVE GFS AS SYSTEM NOW APPROACHING PACIFIC NORTHWEST ACTS AS KICKER WHEN IT DIVES SOUTH. INCREASED THE WESTERN PORTIONS OF CWA INTO THE "LIKELY" RAIN CHANCE CATEGORY SATURDAY NIGHT....THEN SPREAD THAT TO THE EAST ON SUNDAY. THUNDERSTORMS COULD BE SEVERE OVER THE WESTERN COUNTIES ESPECIALLY INTO THE EARLY NIGHTTIME HOURS SATURDAY. HIGHS SATURDAY IN THE UPPER 70S MOST AREAS...LOWS SATURDAY NIGHT AGAIN MILD...IN THE MIDDLE 50S. ON SUNDAY...UPPER WAVE EJECTS NORTHEAST ACROSS THE CWA WITH BEST PRECIPITATION CHANCES MORNING INTO MID AFTERNOON ON THE GFS...THE NAM A BIT SLOWER. AGAIN GIVEN THE SHEAR AND INSTABILITY...SOME POTENTIAL FOR SEVERE BUT WILL DEPEND ON EXTENT OF SATURDAY NIGHT CONVECTION. WITH CLOUD COVER AND PRECIPITATION...HIGHS SUNDAY IN THE LOWER TO MIDDLE 70S. HAVE COMPROMISED ON GFS/NAM MOVEMENT THUS LEFT SOME LOW CHANCE POPS FOR SUNDAY EVENING...THE GFS WOULD HAVE PRECIP EXITING THE AREA BY 00Z MON. ONLY SOME MINOR BLENDING CHANGES TO GOING FORECAST BEYOND SUNDAY NIGHT. FRONTAL BOUNDARY TO THE SOUTH GIVES SOME POTENTIAL FOR THUNDERSTORMS OVER THE SOUTHERN COUNTIES ON MONDAY. NEXT WAVE ENTERS THE AREA MONDAY AND BECOMES A SLOW MOVER IN THE SOUTHERN STREAM GIVING A PROLONGED PERIOD OF PRECIPITATION CHANCES TUESDAY INTO WEDNESDAY. HIGH TEMPERATURES MONDAY AND TUESDAY MAINLY IN THE LOWER TO MID 70S...COOLING INTO THE MID TO UPPER 60S FOR WEDNESDAY AND THURSDAY...LOWS MAINLY IN THE RANGE OF THE UPPER 40S TO LOWER 50S. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PF ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 248 PM MDT FRI APR 20 2007 .SHORT TERM... (TONIGHT AND SATURDAY) CURRENTLY...DRY LINE HAS MIXED EASTWARD TO THE KANSAS BORDER...WITH DEWPOINTS FALLING INTO THE TEENS AND 20S MOST AREAS EAST OF THE MOUNTAINS. DEEP MIXING BEGINNING TO CRANK UP WIND SPEEDS MANY AREAS...WITH GUSTS OVER 30 KNOTS AT 20Z. TONIGHT...LATEST 18Z NAM AND RUC BOTH KEEP THE BOUNDARY ROUGHLY STATIONARY THIS AFTERNOON...WITH A SLIGHT WESTWARD PUSH THIS EVENING. NEITHER NAM OR GFS BREAK OUT ANY PRECIP THIS EVENING OVER THE PLAINS...BUT LATEST RUC SUGGESTS CONVECTION MAY BREAK OUT OVER SOUTHWEST KANSAS AND OKLAHOMA PANHANDLE...POSSIBLE ASSOCIATED WITH SUBTLE DRY LINE BULGE AND LOCALLY ENHANCED CONVERGENCE. COUPLE MESONET OBS SOUTH OF HIGHWAY 50 IN WESTERN KS HINT AT THIS AS WELL...WITH WINDS BACKING TO THE SOUTHEAST. WILL KEEP THE LOW POPS IN PLACE ALONG THE KANSAS BORDER TO ACCOUNT FOR CONVECTIVE POTENTIAL...THOUGH IN THE END WONDER IF ANYTHING WILL HAPPEN AS UPPER LOW MAY BE TOO FAR WEST AND CONVERGENCE TOO WEAK TO OVERCOME RATHER SUBSTANTIAL INHIBITION. FARTHER WEST...COULD SEE A FEW -SHSN BREAK OUT ALONG THE CONTINENTAL DIVIDE AFTER MIDNIGHT AS INITIAL SURGE OF MID AND HIGH LEVEL MOISTURE MOVES EAST. DOUBT WE`LL SEE MUCH PRECIP INITIALLY AS VERY DRY LOW LEVELS WILL TAKE TIME TO MOISTEN. SATURDAY...UPPER LOW EJECTS ACROSS THE STATE...WITH BROAD AREA OF UPWARD MOTION MOVING OVER SOUTHERN COLORADO. DRYLINE NEVER APPEARS TO MAKE MUCH OF PUSH WESTWARD IN THE MORNING...AND BY AFTERNOON AXIS OF DEEP INSTABILITY IS ALONG THE KS BORDER ONCE AGAIN. KEPT THE CHANCE POPS IN PLACE OVER THE FAR EAST...ALONG WITH A MENTION OF SEVERE AS 0-6KM SHEAR IS 50 PLUS KNOTS AND CAPES WELL OVER 1000 J/KG. ELSEWHERE...SUSPECT MODELS ARE OVERDONE WITH PRECIP...AS LOW LEVEL AIR MASS IS FAIRLY DRY AND STRONG S-SW DOWNSLOPE FLOW DEVELOPS OVER THE EASTERN MOUNTAINS. TRIMMED BACK POPS OVER THE EASTERN MOUNTAINS AND I-25 CORRIDOR TO LOW CHANCES...WOULDN`T BE SURPRISED IF MANY AREAS ALONG I-25 STAYED DRY. ANY CONVECTION WHICH DOES FIRE HAS THE POTENTIAL TO PRODUCE SOME VERY GUSTY WINDS DUE TO STRONG WINDS ALOFT...THOUGH FORECAST SOUNDINGS LACK THE CLASSIC INVERTED-V PROFILE DUE TO THE PRESENCE OF VARIOUS MID LEVEL MOIST LAYERS. OVERALL...FORECAST WAS IN GOOD SHAPE AND NEEDED ONLY MINOR ADJUSTMENTS. --PETERSEN .LONG TERM... (SAT NITE THROUGH THURSDAY) ...SEVERE THUNDERSTORMS POSSIBLE EARLY SAT EVENING AND ESPECIALLY MONDAY... ...A WET MONDAY NITE AND TUESDAY...(HEAVY WET SNOW FOR N EL PASO COUNTY?)... CONVECTION IS THE MAIN CONCERN THIS FCST PERIOD. STRONG SHORT WAVE CURRENTLY MOVING ONSHORE S CALIF AS I WRITE WILL BE THE WEATHER MAKER EARLY MONDAY EVENING AS THIS WILL FORCE A BROKEN LINE OF ROTATING CONVECTION TO BE IN THE VICINITY OF THE CO/KS BORDER BY OOZ SUNDAY. THE QUESTION IS NOT WILL CONVECTION FORM...BUT WHERE AND HOW FAST WILL IT MOVE. IT IS POSSIBLE THAT THE CONVECTION MAY BE OUT OF CO BY 00Z SUNDAY...BUT ITS BEST TO KEEP THE MENTION OF STORMS IN THE FORECAST...AT LEAST THROUGH EARLY SAT EVENING. ALL PARAMETERS WILL BE IN PLACE TOMORROW...INCLUDIGN SUFFICIENT SHEAR AND CAPE...SO WHEN STORMS GO UP...THEY WILL ROTATE. SPC ALREADY HAS A SLIGHT RISK ACROSS THE FAR E PLAINS WITH A STRONGLY WORDED MOD RISK (AND ASSOCIATED DAY 2 HIGH PROBABILITIES) JUST EAST OF THE AREA TOMORROW AFTERNOON AND EVENING. AFTER THIS SYSTEM GOES BY...A STRONGER SYSTEM LOOMS FOR MONDAY. AT THIS TIME...IT APPEARS ALL OF THE E CO PLAINS WILL BE UNDER THE GUN AS WIDESPREAD MODERATE TO STRONG SW FLOW ALOFT WILL OVERSPREAD STRENGTHING SE FLOW AT THE SFC. MORE THAN SUFFICIENT DEEP LAYER SHEAR WILL BE IN PLACE BY MONDAY AFTERNOON. CURRENT SIMULATIONS SHOW THAT SUFFICIENT CAPE SHOULD BE IN PLACE ALONG WITH INCREASING FORCING...SO I ANTICIPATE QUITE A FEW SUPERCELLS...SOME POTENTIALLY TORNADIC...WILL DEVELOP OVER THE REGION ON MONDAY AFTERNOON. THIS SYSTEM IS FCST TO GET WOUND UP MONDAY NIGHT AND TUESDAY AS IT MOVES SLOWLY ACROSS SE CO INTO NW KS. WRAPAROUND PRECIP WILL DEVELOP BY LATE MONDAY/EARLY TUESDAY AND IT WILL GET WET ACROSS THE E PLAINS...ESPECIALLY THE PALMER DVD. WE MAY ALSO BE DEALING WITH A SNOWSTORM ACROSS THE E FACING SLOPES OF THE S MTNS. HEAVY WET SNOW WILL ALSO BE POSSIBLE ACROSS N EL PASO COUNTY. ITS STILL TOO EARLY TO KNOW IF THIS WILL HAPPEN...BUT PATTERN RECOGNITION INDICATES IT IS A POSSIBILITY. FOR THE MTNS MONDAY AND MONDAY NIGHT...THERE WILL BE A WINDOW OF OPPURTUNITY FOR A PERIOD OF HEAVY SNOW...ESPECIALLY OVER THE SW MTNS LATE MONDAY INTO MONDAY NIGHT AS MODERATE SW FLOW ALONG WITH FAVORABEL LAPSE RATES MOVE OVER THIS REGION. BY LATE TUE THE SYSTEM SHOULD BE MOVING OUT OF THE REGION. NEXT WX SYSTEM WILL MOVE IN LATE IN THE WEEK. THIS SYSTEM SHOULD BRING IN COOLER AIR AND JUST A CHANCE OF SOME LIGHTER PRECIP. /HODANISH && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 10/34 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 258 PM CDT FRI APR 20 2007 .SHORT TERM...PAST MORNING UPPER AIR DATA IN COMBINATION WITH LATEST WATER VAPOR IMAGERY REVEALS A STRONG WAVE DIGGING INTO THE SOUTHWEST CONUS WHILE A RIDGE IS SEEN STRETCHING FROM THE GREAT LAKES INTO THE LOWER MS RIVER VALLEY. THIS IS LEAVING THE CENTRAL PLAINS UNDER AN ACTIVE SOUTHWEST FLOW REGIME ALOFT ALTHOUGH SOME WEAK SHORT WAVE RIDGING IS CURRENTLY DOMINATING THE AREA. CURRENT OBJECTIVE SURFACE ANALYSIS SHOWS A DEEPENING LEE TROUGH ALONG THE FRONT RANGE REGION OF COLORADO WHILE A WEAK WARM FRONT IS SHOWN LIFTING SLOWLY NORTH INTO THE DAKOTAS WHICH HAS TRIGGERED SOME ELEVATED CONVECTION OVER THAT AREA. MAIN FEATURE OF NOTE ACROSS THE AREA IS A LARGE DECK OF STRATUS STRETCHING FROM NORTHERN OK ACROSS CENTRAL SECTION OF KANSAS AND NEBRASKA INTO SOUTH DAKOTA. THIS STRATUS HAS CREATED A DECENT DIFFERENTIAL HEATING BOUNDARY THIS AFTERNOON. MAIN QUESTION AS THE AREA HEADS INTO TONIGHT IS IF ANY CONVECTION COULD POTENTIAL FIRE ALONG THE AFOREMENTIONED DIFFERENTIAL HEATING BOUNDARY. QUICK EXAMINATION OF VIS SATELLITE IMAGERY REVEALS LITTLE SIGN OF DEEPER CONVECTION ATTEMPTING TO DEVELOP WITH RUC LOW LEVEL LAPSE RATES AND CIN VALUES STILL INDICATING A STRONG CAP. AN ISOLATED CHANCE MAY STILL EXIST NORTH OF A BEAVER CITY TO GREELEY LINE...BUT DECIDED TO REMOVE CHANCE OF THUNDERSTORMS OVER REMAINING AREA. LATE SATURDAY INTO SATURDAY NIGHT CONTINUE TO LOOK ACTIVE ACROSS THE PLAINS AS THE SOUTHWEST CONUS UPPER WAVE EJECTS NORTHEAST INTO THE CENTRAL PLAINS. THIS WAVE WILL PUSH A DRYLINE EAST INTO THE HIGH PLAINS BY MID TO LATE AFTERNOON TOMORROW WITH STRONG TO SEVERE CONVECTION DEVELOPING RAPIDLY ALONG AND EAST OF THE BOUNDARY. THIS WILL LEAVE MOST OF NORTH CENTRAL KANSAS INTO CENTRAL NEBRASKA FAR ENOUGH EAST ON SATURDAY THAT DRY CONDITIONS SHOULD PREVAIL UNTIL SATURDAY EVENING. HOWEVER...IT APPEARS AS THOUGH ANY DISCRETE CONVECTION OVER THE HIGH PLAINS DURING THE AFTERNOON TO EARLY EVENING WILL CONGEAL INTO A LINEAR MCS. WITH DEEP LAYER SHEAR IN EXCESS OF 45 KTS AND LINE SEGMENT MOTION POTENTIALLY IN EXCESS 40 KTS...CONCERNED WESTERN HALF OF CWA MIGHT SEE NASTY BOWING SEGMENTS WITH STRONG DAMAGING WINDS DURING THE EVENING. SEVERE THREAT SHOULD START TO FADE DURING THE OVERNIGHT HOURS AS THE MAIN UPPER SYSTEM AND ASSOCIATED DEFORMATION ZONE SLIDE INTO THE PLAINS. THIS MAY SET THE STAGE FOR SOME WIDESPREAD HEAVY RAIN ACROSS THE AREA. NOT CONCERNED WITH FLOODING AT THIS POINT...BUT CANNOT RULE OUT SOME NUISANCE ISSUES. .LONG TERM...12Z SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE WHEN PRECIPITATION WILL END ON SUNDAY...PRECIPITATION EXPECTED WITH ANOTHER WAVE FROM MONDAY THROUGH WEDNESDAY AND TEMPERATURES THROUGH THE PERIOD. AN UPPER LOW PRESSURE SYSTEM CONTINUES TO MOVE THROUGH THE CENTRAL PLAINS AND INTO THE GREAT LAKES ON SUNDAY. WITH THE UPPER LOW MOVING OUT OF THE AREA THUNDERSTORMS SHOULD COME TO AN END SOMETIME ON SUNDAY. EXPECT THAT THE SOUTHWEST COULD SEE AN END TO THE PRECIPITATION DURING THE MORNING AND EXPECT THAT THE PRECIPITATION WILL END FOR THE REMAINDER OF THE FORECAST AREA BY EVENING. ONCE THE LOW MOVES OUT THE MOISTURE DECREASES. IN ADDITION...A WEAK SURFACE HIGH PRESSURE SYSTEM MOVES IN TO THE REGION. DO NOT EXPECT THAT IT WILL COMPLETELY CLEAR SKIES...BUT IT SHOULD BECOME PARTLY CLOUDY. THE NEXT UPPER LEVEL LOW WILL START TO AFFECT THE REGION MONDAY. AS THE SURFACE LOW DEVELOPS IN THE LEE OF THE ROCKIES THE SOUTH WINDS WILL ALLOW MOISTURE TO STREAM INTO THE AREA. THEN AS THE FIRST WAVES START TO SLIDE INTO THE REGION...THERE IS A CHANCE OF THUNDERSTORMS MONDAY AFTERNOON IN THE SOUTHWEST AND SPREADING ACROSS THE AREA MONDAY EVENING. AS THE UPPER LOW MOVES INTO THE REGION AND THE SURFACE LOW DRIFTS TO THE EAST MOISTURE IS STREAMING INTO THE AREA. AS THE UPPER LOW MOVES ACROSS THE AREA THUNDERSTORMS WILL LIKELY DIMINISH...BUT SHOWERS ARE STILL POSSIBLE UNTIL THE LOW MOVES FAR ENOUGH EAST WEDNESDAY NIGHT. TEMPERATURES SHOULD REMAIN WARM SUNDAY AND MONDAY AHEAD OF THE SURFACE LOW PRESSURE SYSTEM. THEN TUESDAY THROUGH THURSDAY...WITH THE CLOUDS AND PRECIPITATION AROUND EXPECT IT TO BE A BIT HARDER TO WARM AS MUCH SO HAVE COOLER TEMPERATURES. BUT BY FRIDAY WITH PRECIPITATION GONE AND SOME SUN...TEMPERATURES SHOULD START TO WARM UP AGAIN. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 350 PM CDT FRI APR 20 2007 .SHORT TERM...INITIALLY SEVERE THUNDERSTORMS IN NORTHEAST SD HAS SLACKENED A BIT BUT ARE BEGINNING TO SPREAD INTO SOUTHEAST ND. THEY ARE MOVING NORTH ON THE NOSE OF 850 MB JET AND BRINGING ELEVATED INSTABILITY WITH IT AND AHEAD OF AN UPPER LEVEL SHORTWAVE. HOWEVER THE JET CORE IS ONLY 35-40 KNOTS ACCORDING TO RUC AND AREA PROFILERS AND WILL LIKELY NOT SUPPORT STRONG THUNDERSTORMS MUCH EARLY THIS EVENING. RUC SHOWS THE JET STRENGTHENING TO 50 KNOTS BY 06Z SOUTH OF WAHPETON BUT 850 MB CAPE IS NORTH OF GFK BY THEN. STILL...THIS ABR REPORTED ALMOST A HALF INCH OF RAIN IN ONE HOUR TO SHOW THE POTENTIAL OF PRECIPITATION APPROACHING THIS WEEKEND. SEVERE POTENTIAL ON SAT REMAINS THOUGH SURFACE DEW POINTS IN THE MID/UPPER 50S ON SAT AND THE LACK OF A STRONG SHORTWAVE MAY LIMIT SURFACE BASED STORMS A BIT. THREAT OF HEAVY RAIN WILL BE LOCALIZED WITH 1.25 INCH OR SO OF PRECIPITABLE WATER BUT A TRAINING LINE OF STORMS MAY PRODUCE MORE. LEANED ON HPC AND NAM QPF MOST BUT 3 DAY QPF ENDED UP BEING SIMILAR TO HPC. NAM PICKED UP ITS PROGRESSION TO MATCH GFS WHILE BACKING OFF A BIT ON QPF AMOUNTS...SO FAVORED NAM OVERALL. .LONG TERM...(TUE-FRI) A SYSTEM CURRENTLY OVER THE ERN PAC OCEAN...AROUND 48N 148W... IS PROGGED TO GENERATE A SHORT WAVE THAT WILL HIT SHORE AROUND SUNDAY IN NRN CA. THIS SYSTEM PROGGED TO DEVELOP OVER CNTRL ROCKIES AND MOVE THROUGH CENTRAL PLAINS MID NEXT WEEK. CURRENT PROGS SHOW MAIN ENERGY WELL SOUTH OF CWA. WHEREAS PREVIOUS RUNS SHOWED A BAND OF H700 FRONTOGENESIS FORCING JUST SOUTH OF THE CWA...THREAT OF PRECIP NOW LOOKS TO BE FURTHER SOUTH. THUS I REMOVED RAIN SHOWERS FROM SOUTHERN TIER COUNTIES FOR LATE MON NIGHT/EARLY TUE. NEXT EVENT OF INTEREST IS FOR THURSDAY NIGHT INTO FRIDAY...WHERE 12Z GFS IS BRINGING A SHORT WAVE ACROSS EXTREME SRN CANADA AND MT/ND. LATEST GFS RUN FASTER THAN THE ECMWF...WHICH SHOWS A SFC RIDGE OVR ERN MN...AND AN UPPER LEVEL RIDGE ALOFT...THURSDAY NIGHT. WAVE SHOWS UP BEST ON ECMWF H700-H850 RH PROG. ECMWF MOVES WAVE INTO CWA FRIDAY MORNING. HPC BLEND SHOWING 70 PERCENT ECMWF SOLUTION...THUS BRING PRECIP INTO CWA ON FRI MORNING. .AVIATION VFR CONDS EARLY IN TAF AND TWEB PERIODS. HOWEVER...AS MOIST AIR CONTINUES TO PUMP INTO CWA FROM THE SOUTH...THREAT OF CONVECTION INCREASES. WORST THREAT WILL BE SOUTH OF KFAR WHERE SPC HAS ISSUED A SEVERE WEATHER WATCH. EXPECT CIGS TO GENERALLY BE VFR OUTSIDE OF TSTMS...AND LOWERING TO 2000 TO 3000 FEET BY MIDNIGHT. NAM12 SHOWING A TIGHT DEWPOINT GRADIENT ALONG A LINE EXTENDING FROM SW OF KBIS TO NE OF KDVL...WITH SFC TROF JUST TO THE EAST OF THIS BOUNDARY. CONSEQUENTLY...TWEB ROUTE FROM KBIS TO KFAR SHOULD SEE STRONGEST CONVECTIVE ACTIVITY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ GV nd