AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 333 PM MDT MON MAY 19 2008 .SHORT TERM... (TONIGHT AND TUESDAY) WARM AND DRY ACROSS MUCH OF THE FORECAST AREA UNDER NORTHWEST FLOW. UPPER RIDGE BUILDING TO OUR WEST. RIVERS RESPONDING TO SNOW MELT INCREASE WITH RIO GRANDE AT DEL NORTE UP ABOUT 6 INCHES BUT STILL WELL BELOW ANY ACTION STAGE. TONIGHT...WEAK DISTURBANCE MOVING THROUGH THE FLOW SHOWING UP ON WV IMAGERY. FEATURE TRAVELING SOUTHEAST WITH THE FLOW AND SHOULD CROSS SOUTHERN COLORADO THIS EVENING. RUC PICKING UP ON THIS FEATURE WITH SMALL AREA OF PRECIPITATION OVER PIKES PEAK REGION. NAM ALSO SEEING THIS BUT HAS LESS PRECIP. CURRENT GRIDS HAVE ISOLATED -TSRA MENTIONED WHICH LOOKS REASONABLE. DEW POINTS ARE IN THE 20S MOST AREAS AND LOOKS LIKE MOISTURE IS AT MID LEVELS. MODEL SOUNDINGS ARE INVERTED V SO EXPECT WORST CASE TO BE VIRGA AND PERHAPS ISOLATED WIND GUSTS. FEATURE TRAVELS TO KS BORDER BY 06S. EXPECT SNOWMELT TO CONTINUE WITH TEMPS REMAINING MILD OVERNIGHT. TUESDAY...WARM AGAIN WITH FORECASTED TEMPS SOME 5 DEGREES ABOVE GUIDANCE NUMBERS. MODELS HAVE BEEN UNDER PLAYING THE TEMPS PAST FEW DAYS SO LOOKS REASONABLE CONSIDERING WARM AIR ADVECTION PATTERN. WINDS SHOULD NOT BE A PROBLEM TUESDAY BUT FUELS REMAIN VERY DRY BELOW 9000 FEET. SURFACE WINDS SHOULD FAVOR DIURNAL PATTERN. WARM TEMPS WILL ACCELERATE SNOW MELT SO LOOK FOR FLOW TO INCREASE ESPECIALLY SMALL CREEKS AND STREAMS FEEDING THE RIO GRANDE AND UPPER ARKANSAS. -FORTUNE- .LONG TERM... (TUESDAY NIGHT THROUGH NEXT MONDAY) LEFT THE ISOLATED POPS IN PLACE FOR TUESDAY EVENING AS MODELS TRY TO HOLD ONTO SOME VERY MODEST LOW LEVEL MOISTURE OVER THE PLAINS. WEDNESDAY STILL APPEARS TO BE A CRITICAL FIRE WEATHER DAY OVER MOST OF THE AREA...AS UPPER LOW CLOSES OFF OVER THE GREAT BASIN AND DRYLINE SHARPENS UP OVER THE PLAINS. NAM AND ECMWF KEEP THE DRYLINE WELL WEST OF THE KS BORDER THROUGH THE DAY...WITH GFS TRENDING WESTWARD AS WELL. FOR NOW...KEPT THE FIRE WEATHER WATCH IN PLACE FOR ALL OF THE PLAINS...BUT MAY NEED TO TRIM THE EASTERN TIER OF COUNTIES OFF IF SUBSEQUENT MODEL RUNS KEEP CONTINUE TO KEEP DEWPOINTS UP. TSRA CHANCES ALONG THE DRYLINE LOOK FAIRLY LOW...AS MOISTURE IS VERY SHALLOW AND CONVERGENCE WEAK. 700 MB TEMPS OF 14-16C AND FORECAST SOUNDINGS SUGGEST A FAIRLY STOUT CAP AS WELL. WILL HOLD ON TO ISOLATED POPS IN PLACE OVER THE FAR EAST...BUT KEEP I-25 CORRIDOR AND MOST EASTERN MOUNTAINS DRY WITH DEWPOINTS TANKING AND DOWNSLOPE DOMINATING. KEPT THE CHANCE OF TSRA OVER THE CONTINENTAL DIVIDE...CLOSER TO THE UPPER LOW...THROUGH WED. NOT SURE WHY GUIDANCE HAS COOLED WED MAX TEMPS BACK INTO THE 80S ON THE PLAINS...STILL LOOKS LIKE LOW TO MID 90S GIVEN 700MB TEMPS NEAR 16C. FORECAST FOR THU AND BEYOND HIGHLY DEPENDENT ON DRYLINE POSITION AND ANY EASTWARD WOBBLES OF THE WESTERN U.S. UPPER LOW. 12Z NAM/GFS SHOVE THE DRYLINE WELL EAST INTO KANSAS THU AFTERNOON...WHILE ECMWF IS FARTHER WEST. STILL LIKE THE EC SOLUTION BEST...BUT EVEN IT WOULD SUGGEST MAIN CHANCE OF TSRA WOULD BE ONLY ACROSS THE FAR EASTERN PLAINS INTO NORTHEAST COLORADO. CERTAINLY PLENTY OF SHEAR FOR SEVERE STORMS IF WE CAN HOLD ON TO THE MOISTURE...WITH 0-6KM VALUES RUNNING OVER 70 KNOTS. DRY DOWNSLOPE FLOW AGAIN OVER THE EASTERN MOUNTAINS AND ADJACENT PLAINS...THUS REMOVED POPS FROM MOST EASTERN MOUNTAINS AND THE SOUTHERN I-25 CORRIDOR. WILL LIKELY NEED ANOTHER FIRE WEATHER HIGHLIGHT THESE AREAS THURSDAY AFTERNOON. NAM A LITTLE MORE OPTIMISTIC SPREADING PRECIP EASTWARD OVER THE CONTINENTAL DIVIDE...WITH GFS MUCH DRIER...WILL KEEP JUST SCATTERED POPS IN PLACE FOR NOW. MODEL 700MB TEMPS COOL SLIGHTLY...SO TRIMMED BACK MAX TEMP GRIDS JUST A TOUCH. FORECAST FOR FRIDAY INTO THE HOLIDAY WEEKEND STILL UNSETTLED...WITH DRYLINE LURKING ON THE PLAINS THROUGH THE PERIOD AND VARIOUS PIECES OF ENERGY ROTATING AROUND THE WESTERN U.S. CUT- OFF. IN GENERAL...12Z MODELS LOOKING MUCH DRIER THAN 24 HOURS AGO...LIFTING UPPER ENERGY TOO FAR NORTHWEST OF THE AREA TO HELP MUCH WITH PRECIP GENERATION. IN FACT...12Z GFS KEEPS DRY SLOT OVER THE AREA THROUGH MONDAY...WITH ALMOST NO PRECIP OVER SOUTHERN COLORADO EXCEPT OVER THE FAR EAST AND EXTREME WEST. SUPPOSE THIS WILL CHANGE TOMORROW...SO WILL KEEP THE LOW POPS AND SLIGHTLY COOLER TEMPS IN PLACE UNTIL THE DUST CLEARS. --PETERSEN && .AVIATION... VCTS IN COS TAF BASED ON SHORT WAVE EMBEDDED IN NORTHWEST FLOW. FAIRLY DRY AT LOW LEVELS SO EXPECT MOSTLY VIRGA WITH ISOLATED WIND GUSTS. ACTIVITY SHOULD CONTINUE TO MOVE SOUTHEAST. OTHERWISE VFR CONDITIONS THROUGH TUESDAY. && .PUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR COZ221-222-224>237. && $$ 21/10 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 158 AM EDT SUN MAY 18 2008 .SYNOPSIS... AN OCCLUDED FRONT WILL CROSS THE AREA OVERNIGHT. ANOTHER DISTURBANCE WILL MOVE ACROSS THE REGION SUNDAY RESULTING IN RAIN DURING THE AFTERNOON AND EVENING HOURS. AN UPPER LEVEL DISTURBANCE WILL RESULT IN COOL WEATHER WITH SCATTERED SHOWERS FOR THE START OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AT 02Z...AN OCCLUDED BOUNDARY CONTINUES TO MOVES ACROSS ERN NY AND INTO NEW ENGLAND. THE H500 SHORTWAVE TIED THE BOUNDARY IS MOVING THROUGH EXTREME SOUTHEASTERN ONTARIO...AND NORTH OF LAKE ONTARIO BASED ON THE THE LATEST RUC13. THE LATEST RADAR/LTG OVERLAY SHOWS ALL THE SHOWERS AND ISOLD TSRAS WEAKENING WITH THE LOSS OF THE DAYTIME HEATING. WE PLACES ISOLD/SCT SHRAS PRIOR TO MIDNIGHT...AND THEN WENT DRY THEREAFTER. WE HAVE NOTICED A DEEP DRY LAYER IN THE 0000 UTC ALY SOUNDING...WHICH HAS RESULTED IN THE ECHOES ON THE RADAR BEING TOO HIGH IN THE HUDSON VALLEY /VIRGA EFFECT COUPLED WITH ATTENUATION/. WE DID KEEP PATCHY FOG IN THE VALLEY LOCATIONS BELOW 500 FT WHERE THE BOUNDARY LAYER SHOULD DECOUPLE. A BREEZE SHOULD CONTINUE OVER THE HIGHER TERRAIN FROM THE SOUTHWEST TO SOUTH AT 5-10 KTS. TEMPS/DEWPTS WERE ADJUSTED BASED ON THE HOURLY TRENDS. THE CURRENT HOURLY TRENDS WERE A LITTLE TOO WARM. NO OTHER CHANGES AT THIS TIME. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... LONGWAVE TROUGH GETS REINFORCED OVER REGION KEEPING WEATHER COOL AND UNSETTLED. MORE ENERGY WILL DIVE OUT OF CENTRAL CANADA INTO TROUGH TONIGHT. A WEAK SURFACE LOW WILL DEVELOP IN RESPONSE OVER PA AND MOVE E-NE INTO SOUTHERN NEW ENGLAND ON SUNDAY. ALOFT...THE UPPER LEVEL LOW AND ASSOCIATED COLD POOL WILL SHIFT SOUTH AND EAST AS THE SHORT WAVE MOVES THROUGH THE BASE OF THE TROUGH. LOOKING AT A WIDESPREAD RAINFALL MAINLY DURING THE AFTERNOON AND EVENING HOURS SUNDAY. THE UPPER LOW AND COLD POOL WILL MOVE DIRECTLY OVERHEAD MONDAY WITH 500 MB TEMPS OF 27-29 CELSIUS. EVEN THOUGH IT WILL BE COOL INSTABILITY SHOWERS WILL OCCUR SINCE IT IS SO COLD ALOFT. YET ANOTHER PIECE OF SHORT WAVE ENERGY WILL DIVE SOUTHEAST OUT OF CENTRAL CANADA MONDAY NIGHT INTO TUESDAY REINFORCING THE TROUGH. THIS ENERGY WILL MOVE FARTHER TO OUR SOUTH THAN THE PREVIOUS ENERGY WITH A WEAK SURFACE LOW MOVING OFF THE COAST JUST SOUTH OF DELMARVA. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... APPEARS LONG WAVE TROUGH WILL REMAIN OVER THE NORTHEAST UNITED STATES INTO LATE IN THE WEEK KEEPING REGION COOLER THAN NORMAL...ABOUT 10 DEGREES FOR HIGHS. NORMAL FOR THIS TIME OF YEAR FOR ALBANY...HIGHS IN THE LOWER 70S AND LOWS IN THE UPPER 40S. AMPLIFIED RIDGE IS EXPECTED TO START BUILDING IN FROM WEST FRIDAY INTO SATURDAY IN TIME FOR THE HOLIDAY WEEKEND. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... THE BACK EDGE OF FIRST CLOUD SHIELD WILL REACH HUDSON VALLEY IN NEXT COUPLE OF HOURS IN WAKE OF TROUGH PRESENTLY MOVING THROUGH REGION. FOG NOT EXPECTED TO BE A PROBLEM EXCEPT AT KGFL WHERE MEASURABLE RAIN FELL AND WHERE BOUNDARY LAYER WILL DECOUPLE AGAIN IN ANOTHER COUPLE OF HOURS. THUS HAVE MVFR TEMPO IFR CONDITIONS AT KGFL BTWN 08Z AND 11Z WITH VARIABLE WINDS AT/OR LESS THAN 3 KTS. THE NEXT SYSTEM WILL LIFT NE FROM SW PA THIS MORNING INTO SOUTHERN NEW ENGLAND THIS EVENING AND THEN INTO THE GULF OF MAINE LATE TONIGHT. RAIN WILL MOVE INTO TAF SITES FROM SW TO NE BEGINNING AT KPOU AROUND 17Z...KALB AROUND 18Z AND KGFL AROUND 19Z WITH A STEADY RAIN CONTINUING INTO THIS EVENING AND THEN DISSIPATING LATER TONIGHT. CIGS/VSBYS WILL LOWER TO MVFR OR CLOSE TO MVFR LEVELS BTWN 1700 UTC AND 2100 UTC. WINDS WILL GENERALLY BE SOUTH TO SOUTHWEST AT 6-10 KTS TODAY SHIFTING TO SOUTHWEST TO WEST AT 4-6 KTS THIS EVENING. OUTLOOK... MONDAY...VFR/MVFR CIGS...BRISK WINDS...SCT -SHRA KALB NORTH. TUESDAY-THURSDAY...VFR/MVFR WITH A CHANCE OF -SHRAS ESPECIALLY LATE TUESDAY AFTERNOON THRU THURSDAY MORNING. && .FIRE WEATHER... UNSETTLED AND COOL WEATHER INTO MID WEEK AS REGION REMAINS UNDER THE INFLUENCE OF AN UPPER LEVEL LOW. RELATIVE HUMIDITY VALUES WILL RECOVER TO 95 TO 100 PERCENT TONIGHT AND DROP TO MINIMUMS OF 45 TO 55 PERCENT MONDAY AFTERNOON. RELATIVE HUMIDITY VALUES WILL RECOVER TO 90 TO 100 PERCENT MONDAY NIGHT AND DROP TO MINIMUMS OF 45 TO 60 PERCENT TUESDAY AFTERNOON EXCEPT FOR 35 TO 45 PERCENT ACROSS THE MID HUDSON VALLEY INTO THE LITCHFIELD HILLS. WINDS WILL BE WESTERLY AROUND 10 MPH THIS EVENING...INCREASING TO 15 TO 20 MPH MONDAY MORNING AND BECOMING GUSTY WITH GUSTY UP TO 35 MPH. THE WINDS WILL DIMINISH MONDAY NIGHT TO 5 TO 10 MPH AND BE 10 TO 15 MPH ON TUESDAY. && .HYDROLOGY... RAINFALL AMOUNTS FROM FRIDAY/S SYSTEM GENERALLY RANGED FROM 0.50-0.75 ACROSS THE EASTERN CATSKILLS INTO THE MID HUDSON VALLEY...SOUTHERN BERKS...AND NW CT...ALTHOUGH ISOLATED HIGHER AMOUNTS OF 1 TO 1.25 INCHES DID OCCUR. FURTHER N/W...RAINFALL AMOUNTS SHARPLY DECLINED...WITH GENERALLY UNDER ONE TENTH OF AN INCH N/W OF THE CAPITAL REGION...AND ONE TENTH TO ONE QUARTER OF AN INCH IMMEDIATELY TO THE S/E OF THE CAPITAL REGION. THE AMOUNTS WERE FAR LESS THAN INDICATED IN STORM TOTAL ESTIMATES FROM THE KENX RADAR...AS SIGNIFICANT BRIGHT BANDING OCCURRED DUE TO A RELATIVELY LOW FREEZING LEVEL DURING THIS RAIN EVENT. SMALLER STREAMS/CREEKS ACROSS PORTIONS OF THE CATSKILLS AND SCHOHARIE BASIN EXPERIENCED MINOR RISES OF 1 FOOT OR LESS THUS FAR FROM THE RAINFALL. SLIGHT ADDITIONAL RISES ARE POSSIBLE THROUGH EARLY TODAY...BEFORE LEVELING OFF LATER TODAY AND TONIGHT. ADDITIONAL RAINFALL AMOUNTS OF ONE TENTH OF AN INCH...TO UP TO ONE QUARTER OF AN INCH ARE POSSIBLE WITHIN SHOWERS/TSTMS LATER TODAY...WITH ANOTHER ONE QUARTER TO ONE HALF OF AN INCH POSSIBLE SUNDAY AND SUNDAY NIGHT. THESE AMOUNTS COULD LEAD TO ADDITIONAL...MINOR RISES ON SMALLER STREAMS AND CREEKS THROUGH MONDAY...WITH LARGER STEM RIVERS ALSO POTENTIALLY WITNESSING MINOR RISES AS WELL EARLY NEXT WEEK. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ AVIATION...11 ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 938 AM EDT MON MAY 19 2008 .DISCUSSION...REST OF TODAY...LATEST RUC ANALYSIS SHOWS 1000-850 MB CONFLUENT ZONE ALIGNED ALONG A CLOUD BAND THAT EXTENDED FROM THE GULF INTO CENTRAL FLORIDA. THE MODELS SHOW THIS CONFLUENT ZONE WEAKENING BUT THE REMNANT MOISTURE WILL LINGER ACROSS THE AREA. SHOWERS AND A FEW STORMS HAVE BEEN MOVING QUICKLY EAST NORTHEAST WITHIN THIS BAND AS DEEP LAYER FLOW IS ANOMALOUSLY STRONG FOR THIS TIME OF YEAR...SO EXPECT THERE WILL BE A CONTINUING CHANCE OF CONVECTION. THE POSITION OF THE JET TO OUR NORTH WILL CONTINUE TO RESULT IN WEAK DIVERGENCE ALOFT BUT ALSO THERE WILL BE CONSIDERABLE DEBRIS CLOUDS OVERSPREADING THE AREA. THEREFORE HEATING SHOULD BE MORE LIMITED AND DO NOT EXPECT THE JUMP TO THE MID 90S THAT OCCURRED YESTERDAY AS THE DEBRIS CLOUDS DISSIPATED. WITH MORE LIMITED HEATING TODAY THE ATMOSPHERE WILL STRUGGLE TO DESTABILIZE SO THE CHANCE FOR STORMS WILL CONTINUE TO BE LOW AND MENTION OF ISOLATED STORMS IN THE CURRENT FORECAST SHOULD SUFFICE. QUICK MOVEMENT OF THE CONVECTION SHOULD LIMIT RAINFALL AMOUNTS... EXCEPT WHERE REPEATED CELLS MOVE ACROSS THE SAME AREA. A FEW SPOTS THAT ARE LUCKY MAY GET A HALF TO ONE INCH. THE CURRENT POP DISTRIBUTION...WHICH HAS 40 PERCENT WITHIN THE BAND OF MOISTURE AND 20 PERCENT ON THE NORTHERN FRINGE...LOOKS LIKE IT SHOULD COVER THE SITUATION. && .AVIATION...BRIEF MVFR CONDITIONS WITH FAST MOVING SHOWERS ARE EXPECTED THROUGH EARLY EVENING...MAINLY FROM ORLANDO-CANAVERAL AND SOUTHWARD. A FEW CELLS MAY ALSO PRODUCE OCCASIONAL LIGHTNING STRIKES AND GUSTY WINDS. DEBRIS CLOUDS ARE FORECAST TO DIMINISH TONIGHT SO LOW STRATUS MAY BE MORE WIDESPREAD. && .MARINE...NO WIND/SEA CONCERNS THE REST OF THE DAY AS OFFSHORE FLOW WILL BE NO MORE THAN 10-15 KNOTS WITH SEAS LESS THAN 2 FEET NEAR SHORE AND 3-4 FEET AT 60 NM OFFSHORE. BOATERS WILL HAVE TO BE AWARE OF SHOWERS MOVING OFFSHORE FROM THE CAPE SOUTHWARD WHERE BRIEF WIND/SEA INCREASES OCCUR ALONG WITH SOME LIGHTNING. && .FIRE WEATHER (PREVIOUS DISCUSSION)...WITH WEST WIND AND DEW POINTS IN THE MID TO UPPER 60S AFTERNOON RH VALUES SHOULD DROP TO THE UPPER 40 AND LOW 50S MOST AREAS THROUGH MID WEEK. ISOLATED LIGHTNING STORMS TODAY...WITH DECREASING THREAT OF AFTERNOON RAIN TUESDAY THROUGH THURSDAY. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ LASCODY/WIMMER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 310 AM EDT SUN MAY 18 2008 .SYNOPSIS... 07Z WATER VAPOR AND H4 RUC ANALYSIS CHARACTERIZED BY LONG WAVE TROUGHING OVER EASTERN CANADA DOWN INTO THE GREAT LAKES AND NORTHEASTERN STATES AND ANCHORED BY AN UNUSUALLY DEEP UPPER LOW OVER SOUTHEAST ONTARIO. ADDITIONAL TROUGHING EXTENDS SOUTHWEST FROM THE MAIN FEATURE AND CONTINUES TO SLIDE EAST ACROSS THE SOUTHERN PLAINS TOWARD THE WESTERN AND CENTRAL GULF COASTS. FURTHER UPSTREAM WE FIND AMPLIFIED RIDGING COVERING THE U.S PACIFIC COAST/INTERMOUNTAIN WEST NORTHWARD INTO SOUTHWEST CANADA. OVERHEAD OF OUR FORECAST AREA WE STILL FIND NEAR ZONAL FLOW FOR THE REST OF THE OVERNIGHT...HOWEVER THE FLOW WILL BE AMPLIFYING AS THE TROUGHING TO OUR WEST CONTINUES EAST THROUGH THE DAY. DEEP SOUTHERN STREAM MOISTURE RIDING NORTH AND EAST AHEAD OF THIS ENERGY IS SPREADING HIGH LEVEL CIRRUS ACROSS OUR SKIES. AT THE SURFACE...GENERAL WESTERLY FLOW IS FOUND ALONG THE GULF COAST WITH TEMPERATURES IN THE 60S. SHORTWAVE ENERGY EMBEDDED WITHIN THE MAIN TROUGH TO OUR NORTH IS DROPPING INTO THE MIDWESTERN STATES AND HELPING TO PUSH A WEAK COLD FRONT SOUTH INTO THE TENNESSEE VALLEY. && .SHORT TERM...(TODAY THROUGH TUESDAY) SHORTWAVE ENERGY FROM EASTERN TEXAS INTO THE LOWER MS VALLEY WILL CONTINUE EAST THROUGH TODAY WHILE MERGING/ABSORBING INTO THE AMPLIFYING EAST COAST TROUGH. MODEL GUIDANCE HAS BEEN REALLY "ALL OVER THE PLACE" IN REGARDS TO THE POTENTIAL FOR SHOWERS ACROSS OUR FORECAST AREA ASSOCIATED WITH THE ACCOMPANIED SYNOPTIC SCALE FORCING. LATEST GUIDANCE PACKAGES FROM THE NAM/GFS/CANADIAN HAVE ALL TRENDED DRIER AND FURTHER SOUTHEAST WITH THEIR QPF (SIGNIFICANTLY DRIER IN TERMS OF THE GFS...18Z MAV POP AT KTLH WAS 76% AND THE 00Z POP IS 27%) BUT ALL STILL DO PRODUCE SOME LIGHT QPF AMOUNTS OVER MAINLY THE SOUTHEASTERN HALF OF THE FORECAST AREA. LOOKING AT THE FORCING MECHANISMS...BROAD AREA OF MODEST DEEP LAYER Q-VECTOR CONVERGENCE IS UNANIMOUSLY PROGGED TO SPREAD EAST ALONG THE CENTRAL AND EASTERN GULF COAST THROUGH THIS AFTERNOON AHEAD OF THE SHORTWAVE AXIS. ALSO WILL BE LOOKING AT A STRENGTHENING 300-250MB JET STREAK FROM THE NORTHEAST GULF OF MEXICO TO THE MID-ATLANTIC COAST. CAN EXPECT SOME ADDITIONAL FORCED ASSENT IN ASSOCIATED WITH RRQ DIVERGENCE TO COMPLETE THE OVERALL DYNAMICS. THE FORCING WILL BE MAXIMIZED OVER THE SOUTHEAST HALF OF THE FORECAST AREA SO NO SURPRISE THAT THIS WILL WHERE THE GUIDANCE IS GENERATING ITS LIGHT QPF. THE DOWNFALL TO THE WHOLE SYSTEM IS THAT THE OVERALL AVAILABLE MOISTURE IS NOT IMPRESSIVE. TO SUM IT ALL UP...WILL BE KEEPING SLIGHT TO CHANCE POPS IN THE FORECAST MAINLY OVER THE AREAS DESCRIBED ABOVE BUT CERTAINLY DO NOT WANT TO IMPLY A WASHOUT OF A DAY. SHOWER ACTIVITY THAT DOES GET GOING SHOULD BE NUISANCE WDLY SCT TO SCT IN NATURE...BE ON THE LIGHT SIDE AND LIKELY NOT AMOUNT TO MUCH IN THE WAY OF QPF. MOST OF THE DAY WILL BE DRY FOR ALL. EVEN WITHOUT THE SHOWERS WILL BE GOING WITH A PARTLY TO MOSTLY CLOUDY DAY REGIONWIDE WITH THE MOST WIDESPREAD CLOUDS OVER SOUTHERN AND EASTERN PART OF THE AREA. MORE IN THE WAY OF PARTIAL CLEARING WILL BE POSSIBLE OVER WESTERN PORTIONS OF THE AREA AS THE BEST MID/UPPER LEVEL DYNAMICS SHIFT EAST THROUGH THE AFTERNOON. HIGH TEMPERATURES THIS AFTERNOON GENERALLY IN THE LOWER TO MIDDLE 80S. REMAINDER OF THE SHORT TERM AFTER TODAY LOOKS FAIRLY QUIET IN TERMS OF SENSIBLE WEATHER WITH MODERATING TEMPERATURES AND PARTLY CLOUDY SKIES. GENERAL LONG WAVE TROUGHING WILL REMAIN IN PLACE ACROSS THE EASTERN THIRD OF THE NATION WITH OUR AREA FINDING ITSELF ON THE VERY SOUTHERN PERIPHERY OF THE CIRCULATION. WEAK COLD FRONT SLIPS SOUTH OUT OF THE TENNESSEE VALLEY TONIGHT AND THEN TENDS TO WASH OUT DURING THE SECOND HALF OF THE NIGHT BEFORE BOTHERING OUR AREA. ALL GUIDANCE SHOWS BAND OF SHOWERS ALONG THIS FRONT EARLIER IN THE NIGHT DISSIPATING LONG BEFORE IT REACHES OUR NORTHERN ZONES. SEASONABLE LOWS TONIGHT WITH LOWER AND MIDDLE 60S INLAND AND MIDDLE 60S TO NEAR 70 ALONG THE COAST. MONDAY THROUGH TUESDAY WILL FIND THE SUBTROPICAL SURFACE RIDGE BECOMING ESTABLISHED TO OUR SOUTH WITH ITS AXIS RUNNING ACROSS THE SOUTHERN PART OF THE FL PENINSULA INTO THE SOUTHEASTERN GULF OF MEXICO. THIS WILL KEEP AN INCREASINGLY MOIST SOUTHWESTERLY FLOW GOING INTO OUR ZONES. AIRMASS CONTINUES TO WARM THROUGH THE PERIOD WITH 850MB TEMPS REACHING BETWEEN 14 AND 16C MONDAY AND 16 TO 18C BY TUESDAY. THIS MEANS A RETURN TO NEAR CLIMO OR SLIGHT ABOVE CLIMO TEMPS WITH MONDAY AFTERNOON TOPPING OUT IN THE MIDDLE TO UPPER 80S AND TUESDAY REACHING THE UPPER 80S TO LOWER 90. DUE TO THE ONSHORE SW FLOW CAN EXPECT COASTAL AREAS TO BE JUST A FEW DEGREES COOLER. && .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)... EASTERN CONUS TROUGH WILL STILL BE IN PLACE TUESDAY NIGHT INTO WEDNESDAY. NORTHERN STREAM SHORTWAVE MOVING INTO THE BASE OF THE TROUGH WILL PUSH A WEAK FRONT INTO CENTRAL GEORGIA BY WEDNESDAY AFTERNOON. FRONT EXPECTED TO STALL AS SHORTWAVE PUSHES TO THE EAST...BUT MAY BE ENOUGH MOISTURE TO TRIGGER SOME SHOWERS AND STORMS OVER GEORGIA ZONES. BY THURSDAY...DEEP UPPER LOWS OVER NEW ENGLAND AND THE DESERT SOUTHWEST FLANK A STRENGTHENING RIDGE EXTENDING NORTHWEST FROM THE WESTERN ATLANTIC. EURO AND GFS DISAGREE ON STRENGTH OF A SHORTWAVE MOVING INTO THE RIDGE THURSDAY INTO FRIDAY...WITH EURO MOVING STRONGER SHORTWAVE INTO WEAKER RIDGE. WILL PLAY MIDDLE OF ROAD FOR NOW AND KEEP SOME LOW CHANCE POPS IN FOR THURSDAY AND FRIDAY. MODELS DO AGREE THAT THIS SHORTWAVE WILL HELP DEEPEN THE EASTERN UPPER LOW BY SATURDAY...WITH SOLID HIGH PRESSURE WEDGING DOWN THE EASTERN SEABOARD. BACKDOOR FRONT ASSOCIATED WITH THE DEEPENING EAST COAST TROUGH WILL LIKELY KICK OFF SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY BEFORE MUCH DRIER AIRMASS MOVES INTO THE AREA SUNDAY. .FIRE WX...MODEST INCREASE IN LOW LEVEL MOISTURE ASSOCIATED WITH APPROACHING MID TO UPPER LEVEL SYSTEM WILL KEEP RH VALUES ABOVE CRITICAL LEVELS THIS AFTERNOON. SOUTHWEST LOW LEVEL FLOW WILL REMAIN IN PLACE FOR MONDAY...KEEPING RH VALUES ABOVE CRITICAL LEVELS ONCE AGAIN. NO FIRE WX HEADLINES WILL BE NEEDED. && .AVIATION... VFR CONDITIONS TO PREVAIL THROUGH THE TAF PERIOD. UPPER LEVEL DISTURBANCE WILL CROSS THE AREA SUNDAY ALONG WITH AN INCREASE IN MID AND HIGH CLOUDINESS. THERE REMAINS A CHANCE FOR SOME LIGHT SHOWERS...BUT PROBABILITY IS LOWER THAN PREVIOUSLY THOUGHT SO HAVE GONE BACK TO PROB30S FOR THE SOUTHERN TERMINALS. THESE SAME TERMINALS MAY SEE BRIEF MVFR CONDITIONS WITH THESE SHOWERS. FOR THE MOST PART...CIGS WILL REMAIN ABOVE BKN040. ALONG WITH INCREASED CLOUDINESS...WILL ALSO SEE INCREASED WESTERLY WINDS WITH SOME GUSTS OVER 20KT. && .MARINE... WESTERLY TO SOUTHWESTERLY FLOW CONTINUES ACROSS THE MARINE AREA THROUGH TONIGHT BETWEEN HIGH PRESSURE FAR TO OUR SOUTH AND A WEAK COLD FRONT TO OUR NORTH. WINDS ARE FORECAST TO APPROACH CAUTIONARY LEVELS LATER THIS AFTERNOON INTO TONIGHT. THE FLOW WILL THEN BECOME PREDOMINANTLY FROM THE SOUTHWEST MONDAY INTO THE MIDDLE PART OF THE WEEK WITH WINDS GENERALLY JUST BELOW CAUTIONARY CRITERIA. && .FIRE WEATHER... MODEST INCREASE IN LOW LEVEL MOISTURE ASSOCIATED WITH APPROACHING MID TO UPPER LEVEL SYSTEM WILL KEEP RH VALUES ABOVE CRITICAL LEVELS THIS AFTERNOON. MONDAY AFTERNOON WILL BE A TOUCH DRIER WITH A DEEP MIXING LAYER. DISPERSIONS AND RH VALUES WILL BE VERY CLOSE TO RED FLAG CRITERIA. HOWEVER...GIVEN THE UNCERTAINTY ASSOCIATED WITH DISPERSIONS...WILL HOLD OFF ON WATCH FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 83 63 90 66 91 / 20 10 05 0 05 PANAMA CITY 81 68 85 69 85 / 20 10 05 0 05 DOTHAN 84 64 87 67 90 / 10 05 05 0 05 ALBANY 84 63 89 66 90 / 10 05 05 0 05 VALDOSTA 83 63 88 64 90 / 20 10 05 0 05 CROSS CITY 84 66 89 66 89 / 30 20 05 0 05 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. GM...NONE. && $$ AVIATION/LONG TERM/FIRE WX...CAMP PUBLIC/MARINE...MROCZKA fl AREA FORECAST DISCUSSION...UPDATE FOR AVIATION NATIONAL WEATHER SERVICE DES MOINES IA 534 PM CDT SUN MAY 18 2008 .SHORT TERM...TONIGHT NORTH WINDS WILL DROP OFF VERY RAPIDLY AFTER 5-6 PM THIS EVENING... BECOMING LIGHT SELY AFTER MIDNIGHT. THIS IS IN RESPONSE TO HIGH PRESSURE RIDGE MOVING EWD AND A SURFACE LOW THAT WILL MOVE SEWD FROM THE WRN DAKOTAS IN THE FAST NWLY FLOW. LOW-LEVEL DEWPOINTS ARE VERY LOW DUE TO DEEP MIXING OF DRY AIR DOWN FROM ABOVE...SO IT WILL TAKE AWHILE FOR DYNAMICS TO PRODUCE SIGNIFICANT CLOUDS NORTH OF THE LOW PRESSURE SYSTEM. MODELS HAVE A VARYING IDEA OF HOW THINGS WILL EVOLVE...BUT IT APPEARS THAT BY 09Z...ISENTROPIC LIFT SHOULD SATURATE ENOUGH TO GET SOME LIGHT SHOWER ACTIVITY ACROSS THE NORTHERN HALF OF THE STATE. BETTER CHANCES A LITTLE FARTHER SOUTH ACROSS THE HIGHWAY 20-30 CORRIDOR AND THEN SEWD TOWARD DAYBREAK AS THE MAIN SHORTWAVE COMES THROUGH. CONDITIONAL INSTABILITY MAY ALLOW FOR A FEW RUMBLES OF THUNDER AS THE SHOWERS TRACK RAPIDLY EWD...ENDING ALMOST TO I-35 BY 12Z OR SO AND MUCH OF THE EASTERN FORECAST AREA BY MID MORNING. RAINFALL AMOUNTS SHOULD BE BRIEF AND LIGHT. .LONG TERM...MONDAY THROUGH SUNDAY SHOWERS AND ISOLATED STORMS WILL CONTINUE MONDAY MORNING BEFORE FORCING QUICKLY HEADS SOUTHEAST BY LATE MORNING. BY EARLY MONDAY EVENING...A 100+KT JET STREAK IS PROGGED TO DROP SOUTH INTO IOWA WITH ENHANCED LF QUAD UVM. A MID LEVEL SHORT WAVE TROUGH IS ALSO FORECAST TO DIP ACROSS NORTHEAST IOWA. DEEP LAYER...MAINLY DIRECTIONAL SHEAR SHOULD ALSO BE SUFFICIENT FOR STORM ORGANIZATION...DESPITE ONLY MODEST MU CAPES AROUND 500 J/KG. FORECAST SOUNDINGS INDICATED PLENTY OF DRY BOUNDARY LAYER AIR AND DCAPE FOR ISOLD DAMAGING WIND GUSTS. THE MEAN NW FLOW IS 40+ KTS AND THE IMPACT FOR THE FORECAST AREA WILL LIKELY BE IN THE NEIGHBORHOOD OF 7 TO 11 PM. WILL UPDATE HWO FOR ISOLD SEVERE THREAT...MAINLY ACROSS THE NORTHEAST HALF OF THE FORECAST AREA. COOLER AIR WILL SPREAD INTO THE REGION BEHIND THE SYSTEM TUESDAY WITH CONTINUED NW FLOW. ACTIVE WEATHER RESUMES WEDNESDAY WILL GENERAL MODEL CONSENSUS ON OVERRUNNING SCENARIO...IMPACTING MAINLY THE SOUTHWEST HALF OF THE FORECAST AREA WEDNESDAY AFTERNOON THROUGH THURSDAY. MODEL CONSENSUS REMAINS ELUSIVE IN THE LATER PERIODS. FOR SEVERAL RUNS IN A ROW...THE ECMWF HAS MAINTAINED A STRONG UPPER LEVEL RIDGE AND CAPPING...SHUTTING OFF PRECIP OVER THE CWA FRIDAY THROUGH THE WEEKEND. THAT IS...UNTIL TODAY/S 12Z RUN...WHICH NOW BREAKS DOWN THE RIDGE AND BRINGS IOWA UNDER THE INFLUENCE OF SW FLOW SHORT WAVE TROUGHS SATURDAY AND SUNDAY. THE OPERATIONAL GFS IS STARTING TO TREND TOWARDS A SLOWER...MORE AMPLIFIED SOLUTION...AND DRIER CONDITIONS FOR THE CWA. FOR NOW...WILL STAY WITH THE MORE AMPLIFIED SCENARIO AND HAVE TRIMMED POPS FRI-SUN BACK TO SLIGHT CHC CATEGORY MAINLY W/SW SECTIONS. && .AVIATION...19/00Z VFR CONDITIONS CAN BE EXPECTED OVER THE NEXT 6-12 HOURS ACROSS CENTRAL IOWA TERMINALS AS A HIGH PRESSURE SURFCAE RIDGE CONTINUES TO ENTER THE AREA. GUSTY NORTHWEST WINDS SHOULD GIVE WAY TO STRONGER DECOUPLING BETWEEN 01 AND 02 PER CURRENT RUC SOUNDING FORECASTS SHOWING STRONGER INVERSION...SO WILL HPOLD ONTO GUSTINESS IN TERMINALS UNTIL 02 UTC. BOTH GFS AND NAM/WRF INDICATING SHOWERS MOVING THROUGH CENTRAL IOWA EARLY MONDAY MORNING SO WILL PLACE A -SHRA/SHRA PERIODS IN TERMINALS FROM AROUND 12 TO 16 UTC. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/AVIATION...JUNGBLUTH/71 LONG TERM...KINNEY ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 219 PM CDT MON MAY 19 2008 .DISCUSSION... MOST OF PAH FA NOW IN WARM SECTOR...AWAITING ARRIVAL OF SURFACE LOW ANALYZED AT 19Z NR/JUST SOUTH OF LSX. ATTENDANT COLD FRONT SHOULD BE ENTERING NW REACHES OF FA BY 00Z AS LOW DIVES SSE...HOWEVER NOSE OF SURFACE TDS IS ONLY IN THE 50S AND IN FACT TDS ARE FALLING IN PAH FA THIS PM. SO DESPITE MOISTURE STARVING AT THE SURFACE/LOWEST LAYERS...BLOW OFF MID/HIGH CLOUDS AIDING CAPPING ENVIRO OVER MUCH OF NRN FA...WITH ONLY WAA -SHRA SO FAR. STILL IN SEE TEXT FOR DIFFERENTIAL HEATING ZONE NEAR LOW CENTER...MAINLY SEMO/SWKY...IF CAP CAN BREAK. WILL CONTINUE CARRYING SMALL CHC POPS TIL FROPA TONIGHT...WITH DRYING SOUNDINGS BEGINNING TO SHOW UP FROM WEST AFT 06Z. NAM/GFS BOTH SUPPORT TUE PM INSTABILITY CHC -SHRA AS PVA MAX ROTATES THRU BASE OF MEAN LONG WAVE TROF OVER MID-UPR OH VALLEY...SO INSERTED 20 POP THERE TO CARRY. OTHERWISE ANTICIPATE MAINLY DRIER/COOLER NWLYS PREVAILING THRU THU...WHEN NEXT STROBE OF ENERGY INSERTS SMALL POPS FROM THE WEST...STILL CAUGHT UP IN NWLYS. AFTERWARDS THE CHC SHRIVELS A BOTH GFS/ECMWF ARC HIGH PRESSURE ALOFT TO OUR WEST...WHICH ALLOWS SURFACE HIGH OVER GREAT LAKES TO PROVIDE WINDS FAVORABLE TO DRY THE PROFILE. THEREFORE ANTICIPATE MAINLY DRY END OF WEEK THRU WEEKEND...F0LLOWING HPC LEAD...WHICH GIVES A RETURN FLOW SMALL CHC POP BY DAY 7 OR 8. TEMPS BUT PARTICULARLY TDS WERE TOUGH AS MODELLING OF COOLER SURFACE TDS NOSING INTO FA IS FALLING SHORT. MAYBE NAM MET MOS/RUC HAS A BETTER HANDLE THAN OTHERS WHICH YIELDS A SLIGHTLY COOLER/DRIER APPROACH AKIN TO THE FLOW PATTERN. SO WE USED THAT APPROACH BUT BLENDED WITH THE GOING FORECAST/COLLAB PIC FOR FINAL NEAR TERM SOLUTION...WITH MEDIUM TO LONG RANGE NOS A GENERAL HPC/MEX MOS ACCEPTANCE. && .AVIATION... GIVEN THE NUMERICAL MODEL UNCERTAINTIES...LEANED STRONGLY TOWARD VFR CEILINGS AND VISIBILITIES THROUGH AT LEAST 06Z TUESDAY FOR ALL TAF SITES IN THE WFO PAH FORECAST AREA...WITH ONLY LIMITED MENTION OF SHOWERS. FOR THE KCGI/KPAH TAF SITES...DROPPED MENTION OF SHOWERS SINCE PROBABILITY OF OCCURRENCE THIS AFTERNOON AND EVENING HOURS WITHIN 10 STATUTE MILES OF THE AIRPORTS WILL BE LOW. IF A SHOWER DOES APPEAR TO MOVE TOWARD THESE AIRPORTS...WILL AMEND AS NEEDED. FOR THE KEVV/KOWB TAF SITES...THE VICINITY OF THE WARM FRONT THIS AFTERNOON AND TRAJECTORY OF THE SURFACE NEAR THESE LOCATIONS BETWEEN 00-06Z TUESDAY WARRANTED AN INTERMITTENT /VIA TEMPO/ OR CATEGORICAL MENTION /VIA FROM GROUP/ THROUGH AT LEAST 03Z TUESDAY. MODEL GUIDANCE SUGGESTS SOME DECENT POST FRONTAL MOISTURE AND COLD AIR ADVECTION OVER THE KEVV/KOWB SITES AFTER MIDNIGHT...SO INTRODUCED MVFR CEILINGS THROUGH AT LEAST 14Z TUESDAY...WITH VFR CEILINGS FOR THE REMAINDER OF THE FORECAST PERIOD. CONFIDENCE IS LOW WITH THE DEVELOPMENT OF THESE CEILINGS...SO LATER FORECASTS MAY REQUIRE SOME REVISION. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ HUMPHREY/SMITH ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 139 AM EDT MON MAY 19 2008 .SHORT TERM.../THE REST OF TONIGHT/ ISOLATED SHOWERS REMAIN ACROSS THE NORTHERN COUNTIES DESPITE RATHER LIMITED LOW LEVEL MOISTURE. SMALL MU CAPES NEAR 100 J/KG REMAIN ACROSS THIS AREA AS WELL AS JUXTAPOSITION OF THE STEEPEST LOW AND MID LEVEL LAPSE RATES AS A MID LEVEL SW/V IS MOVING THROUGH THE OH VALLEY. SW PARTS OF THE CWA HAVE CLEARED OUT AND HAVE BECOME MOSTLY CLEAR AND SHOULD REMAIN SO. INTERPOLATION TAKES THE LAST SHOWER NOW OVER MONTGOMERY COUNTY OUT OF THE CWA SHORTLY AFTER 4Z AND ADDITIONAL ISOLATED -SHRA COULD STILL DEVELOP OVER THE SE SINCE HIGHER DEWPOINTS REMAIN THERE. DRIER AIR IS SLOWLY ADVECTING INTO THE SOUTHERNMOST COUNTIES AND DEWPOINTS ARE NEAR 50 ATTM. HEIGHTS WILL RISE LATER TONIGHT ONCE THE SW/V PASSES AND WEAK SFC HIGH PRESSURE WILL BUILD IN AS WELL. SKIES SHOULD BECOME CLEAR IN ALL AREAS BY THE 6Z TO 9Z TIMEFRAME. WENT WITH ISOLATED SHOWERS ENDING IN THE ZFP. WE PLAN TO ISSUE ANOTHER UPDATE TO END ISOLATED SHOWERS NEAR 4Z. AS FOR FOG...CROSSOVER TEMPS MAY NOT BE REACHED IN SOME AREAS...WITH SEVERAL VALLEY AREAS LIKELY ONLY FALLING TO A COUPLE OF DEGREES BELOW. WET GROUND IN MANY AREAS WILL ADD TO THE FOG POTENTIAL. THE SOUTHERNMOST COUNTIES MAY BE MORE FAVORED DUE TO SMALLER INITIAL DEWPOINT DEPRESSIONS. THE PREVIOUS HWO THAT HIGHLIGHTED LOCALLY DENSE FOG HAS THE SITUATION WELL HANDLED AND DID NOT CHANGE. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /TONIGHT THROUGH TUESDAY NIGHT/ A LINE OF SHOWERS AND THUNDERSTORMS CONTINUES TO WORK SOUTHEAST ACROSS THE AREA. HAVE HAD NUMEROUS REPORTS OF PEA SIZE HAIL WITH THE STRONGER STORMS. LOW WET BULB ZERO LEVELS ARE HELPING TO PRODUCE THE HAIL. LAPS AND RUC DATA SHOW CAPES AROUND 500 TO 750 J/KG...WITH LI/S -1 TO -3. THE LINE SHOULD BE JUST ABOUT OUT OF THE AREA AROUND 4 PM. CANNOT RULE OUT AN ADDITIONAL ISOLATED SHOWER OR THUNDERSTORM REDEVELOPING ALONG A VORT MAX MOVING THROUGH THIS EVENING. MODELS HINT AT A SUBTLE FEATURE WITH SOME WEAK OMEGA THIS EVENING...SO WILL KEEP SOME ISOLATED SHOWERS OR STORMS IN THE FORECAST THIS EVENING. SKIES SHOULD BEGIN TO CLEAR OUT TOWARDS MIDNIGHT AND AFTER...AND WILL LIKELY SEE VALLEY FOG DEVELOPING. THE NEXT SYSTEM APPROACHES FOR MONDAY AFTERNOON AND MONDAY NIGHT. GOOD DYNAMICS ARE ASSOCIATED WITH THIS SYSTEM. QUITE A DIFFERENCE IN STRENGTH BETWEEN THE WRF AND GFS. SIDED CLOSE TO THE STRONGER GFS...WHICH IS ALSO IN AGREEMENT WITH THE SREF AND NGM. WILL GO WITH LIKELY POPS ACROSS MUCH OF THE AREA LATE MONDAY...AND CONTINUE THOSE INTO MONDAY NIGHT. SOME ELEVATED INSTABILITY IS ALSO NOTED...AS SHOWALTERS DROP TO -1. IF THIS INSTABILITY IS REALIZED...THE STRONG SHEAR COULD RESULT IN STRONG THUNDERSTORMS. THIS SYSTEM WILL BEGIN TO EXIT TUESDAY...AND WILL MAINTAIN HIGH CHANCE POPS IN THE MORNING. A SECONDARY SURFACE TROF DROPS SOUTHEAST ACROSS THE AREA LATE TUESDAY INTO TUESDAY NIGHT...AND WILL INCLUDE A CHANCE OF SHOWERS AS THIS FEATURE MOVES THROUGH. .LONG TERM.../WEDNESDAY THROUGH SUNDAY/ THE MODELS HAVE TRENDED TO A SLIGHTLY MORE CONSISTENT SOLUTION IN THE LONG TERM. THE LARGE SCALE PATTERN WILL FEATURE LONG WAVE TROFS OVER BOTH THE EASTERN AND WESTERN CONUS...WITH A STRENGTHENING RIDGE IN THE CENTRAL CONUS. ON WEDNESDAY...A VORT MAX SHOULD BE MOVING JUST NORTHEAST OF THE AREA. WILL KEEP THE FORECAST DRY...AS IT LOOKS LIKE THE BEST CHANCE FOR PRECIP WILL BE FURTHER TO THE NORTHEAST OF OUR CWA. BY THURSDAY...MOISTURE TRIES TO SLIDE SOUTHEAST ALONG THE NORTHERN SIDE OF A STATIONARY FRONT LOCATED FROM A SURFACE LOW OVER COLORADO...TO THE SOUTHEASTERN CONUS. WILL MENTION CHANCE POPS FOR SHOWERS THURSDAY AND THURSDAY NIGHT...TAPERING OFF TO SLIGHT CHANCE FRIDAY MORNING AS THE MOISTURE EXITS AND H5 RIDGING STRENGTHENS. WITH THE FRONT WELL TO THE SOUTH OF THE CWA AND INSTABILITY LACKING...WILL NOT MENTION THUNDER. FROM LATER FRIDAY ON THROUGH SUNDAY...WILL KEEP THE FORECAST DRY WITH GRADUALLY WARMING TEMPERATURES AS RIDGING AT H5 AND THE SURFACE BUILDS IN. THE GFS IS FURTHER EAST WITH THE H5 RIDGING...AND BUILDS WARMER AIR IN QUICKER THAN THE ECMWF. THE TREND THE PAST FEW DAYS HAS BEEN FOR A SLOWER RETURN OF WARM AIR...AND WITH THE BETTER RUN TO RUN CONSISTENCY OF THE ECMWF...WENT A LITTLE COOLER THAN GFS MOS. STARTED WITH HPC TEMPERATURE GUIDANCE AND MADE SOME ADJUSTMENTS FROM THERE AGAIN TODAY. && .AVIATION.../06Z TO 06Z/...UPDATED SHRA ACTIVITY HAS ENDED FOR ERN KY. SKIES ARE CLEARING RAPIDLY WITH JUST ISOLATED MID LEVEL AC LINGERING. EXPECTING TEMPS TO DROP OFF AND COULD GET NEAR DWPTS JUST BEFORE DAWN ALTHOUGH AT PRESENT THERE IS A 6-9 DEG SPREAD. HAVE INCLUDED A TEMPO FOR MVFR FOG JUST BEFORE DAWN AND WILL MONITOR FOR POTENTIAL UPDATE. FOR NOW ENJOYING MILD TEMPS AND LIGHT WINDS. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...WJM/JP LONG TERM....WJM AVIATION...DUSTY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 1011 PM EDT SUN MAY 18 2008 .SHORT TERM.../THE REST OF TONIGHT/...UPDATED ISOLATED SHOWERS REMAIN ACROSS THE NORTHERN COUNTIES DESPITE RATHER LIMITED LOW LEVEL MOISTURE. SMALL MU CAPES NEAR 100 J/KG REMAIN ACROSS THIS AREA AS WELL AS JUXTAPOSITION OF THE STEEPEST LOW AND MID LEVEL LAPSE RATES AS A MID LEVEL SW/V IS MOVING THROUGH THE OH VALLEY. SW PARTS OF THE CWA HAVE CLEARED OUT AND HAVE BECOME MOSTLY CLEAR AND SHOULD REMAIN SO. INTERPOLATION TAKES THE LAST SHOWER NOW OVER MONTGOMERY COUNTY OUT OF THE CWA SHORTLY AFTER 4Z AND ADDITIONAL ISOLATED -SHRA COULD STILL DEVELOP OVER THE SE SINCE HIGHER DEWPOINTS REMAIN THERE. DRIER AIR IS SLOWLY ADVECTING INTO THE SOUTHERNMOST COUNTIES AND DEWPOINTS ARE NEAR 50 ATTM. HEIGHTS WILL RISE LATER TONIGHT ONCE THE SW/V PASSES AND WEAK SFC HIGH PRESSURE WILL BUILD IN AS WELL. SKIES SHOULD BECOME CLEAR IN ALL AREAS BY THE 6Z TO 9Z TIMEFRAME. WENT WITH ISOLATED SHOWERS ENDING IN THE ZFP. WE PLAN TO ISSUE ANOTHER UPDATE TO END ISOLATED SHOWERS NEAR 4Z. AS FOR FOG...CROSSOVER TEMPS MAY NOT BE REACHED IN SOME AREAS...WITH SEVERAL VALLEY AREAS LIKELY ONLY FALLING TO A COUPLE OF DEGREES BELOW. WET GROUND IN MANY AREAS WILL ADD TO THE FOG POTENTIAL. THE SOUTHERNMOST COUNTIES MAY BE MORE FAVORED DUE TO SMALLER INITIAL DEWPOINT DEPRESSIONS. THE PREVIOUS HWO THAT HIGHLIGHTED LOCALLY DENSE FOG HAS THE SITUATION WELL HANDLED AND DID NOT CHANGE. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /TONIGHT THROUGH TUESDAY NIGHT/ A LINE OF SHOWERS AND THUNDERSTORMS CONTINUES TO WORK SOUTHEAST ACROSS THE AREA. HAVE HAD NUMEROUS REPORTS OF PEA SIZE HAIL WITH THE STRONGER STORMS. LOW WET BULB ZERO LEVELS ARE HELPING TO PRODUCE THE HAIL. LAPS AND RUC DATA SHOW CAPES AROUND 500 TO 750 J/KG...WITH LI/S -1 TO -3. THE LINE SHOULD BE JUST ABOUT OUT OF THE AREA AROUND 4 PM. CANNOT RULE OUT AN ADDITIONAL ISOLATED SHOWER OR THUNDERSTORM REDEVELOPING ALONG A VORT MAX MOVING THROUGH THIS EVENING. MODELS HINT AT A SUBTLE FEATURE WITH SOME WEAK OMEGA THIS EVENING...SO WILL KEEP SOME ISOLATED SHOWERS OR STORMS IN THE FORECAST THIS EVENING. SKIES SHOULD BEGIN TO CLEAR OUT TOWARDS MIDNIGHT AND AFTER...AND WILL LIKELY SEE VALLEY FOG DEVELOPING. THE NEXT SYSTEM APPROACHES FOR MONDAY AFTERNOON AND MONDAY NIGHT. GOOD DYNAMICS ARE ASSOCIATED WITH THIS SYSTEM. QUITE A DIFFERENCE IN STRENGTH BETWEEN THE WRF AND GFS. SIDED CLOSE TO THE STRONGER GFS...WHICH IS ALSO IN AGREEMENT WITH THE SREF AND NGM. WILL GO WITH LIKELY POPS ACROSS MUCH OF THE AREA LATE MONDAY...AND CONTINUE THOSE INTO MONDAY NIGHT. SOME ELEVATED INSTABILITY IS ALSO NOTED...AS SHOWALTERS DROP TO -1. IF THIS INSTABILITY IS REALIZED...THE STRONG SHEAR COULD RESULT IN STRONG THUNDERSTORMS. THIS SYSTEM WILL BEGIN TO EXIT TUESDAY...AND WILL MAINTAIN HIGH CHANCE POPS IN THE MORNING. A SECONDARY SURFACE TROF DROPS SOUTHEAST ACROSS THE AREA LATE TUESDAY INTO TUESDAY NIGHT...AND WILL INCLUDE A CHANCE OF SHOWERS AS THIS FEATURE MOVES THROUGH. .LONG TERM.../WEDNESDAY THROUGH SUNDAY/ THE MODELS HAVE TRENDED TO A SLIGHTLY MORE CONSISTENT SOLUTION IN THE LONG TERM. THE LARGE SCALE PATTERN WILL FEATURE LONG WAVE TROFS OVER BOTH THE EASTERN AND WESTERN CONUS...WITH A STRENGTHENING RIDGE IN THE CENTRAL CONUS. ON WEDNESDAY...A VORT MAX SHOULD BE MOVING JUST NORTHEAST OF THE AREA. WILL KEEP THE FORECAST DRY...AS IT LOOKS LIKE THE BEST CHANCE FOR PRECIP WILL BE FURTHER TO THE NORTHEAST OF OUR CWA. BY THURSDAY...MOISTURE TRIES TO SLIDE SOUTHEAST ALONG THE NORTHERN SIDE OF A STATIONARY FRONT LOCATED FROM A SURFACE LOW OVER COLORADO...TO THE SOUTHEASTERN CONUS. WILL MENTION CHANCE POPS FOR SHOWERS THURSDAY AND THURSDAY NIGHT...TAPERING OFF TO SLIGHT CHANCE FRIDAY MORNING AS THE MOISTURE EXITS AND H5 RIDGING STRENGTHENS. WITH THE FRONT WELL TO THE SOUTH OF THE CWA AND INSTABILITY LACKING...WILL NOT MENTION THUNDER. FROM LATER FRIDAY ON THROUGH SUNDAY...WILL KEEP THE FORECAST DRY WITH GRADUALLY WARMING TEMPERATURES AS RIDGING AT H5 AND THE SURFACE BUILDS IN. THE GFS IS FURTHER EAST WITH THE H5 RIDGING...AND BUILDS WARMER AIR IN QUICKER THAN THE ECMWF. THE TREND THE PAST FEW DAYS HAS BEEN FOR A SLOWER RETURN OF WARM AIR...AND WITH THE BETTER RUN TO RUN CONSISTENCY OF THE ECMWF...WENT A LITTLE COOLER THAN GFS MOS. STARTED WITH HPC TEMPERATURE GUIDANCE AND MADE SOME ADJUSTMENTS FROM THERE AGAIN TODAY. && .AVIATION.../00Z TO 24Z/ ISOLATED SHOWERS REMAIN A POSSIBILITY FROM JKL NORTH FOR THE NEXT COUPLE OF HOURS BEFORE THE SUN GOES DOWN AND THE ATMOSPHERE STABILIZES. OTHERWISE... FOG IS THE MAIN PROBLEM WITH THIS ISSUANCE. DECIDED TO TREND MORE OPTIMISTIC WITH VSBYS/CIGS LATER TONIGHT AS RAINFALL WAS NOT THAT WIDESPREAD. MIXING BEHIND THE FRONT HAS ALSO ALLOWED THE LOW LEVELS TO DRY OUT QUITE WELL. WITH THAT SAID... IFR VSBYS LATER TONIGHT REMAIN LIKELY IN THE RIVER VALLEYS AND FOR LOCATIONS LIKE LOZ WHICH RECEIVED SOME GOOD RAINFALL EARLIER. NEXT SYSTEM ARRIVES LATE TOMORROW WITH A RETURN OF SHOWERS AND THUNDERSTORMS BUT COVERAGE IS QUESTIONABLE SO BELIEVE A VCTS MENTION WITH VFR CIGS/VSBYS WILL SUFFICE AT THIS TIME. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...WJM/JP LONG TERM....WJM AVIATION...ABE ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 734 PM EDT SUN MAY 18 2008 .SHORT TERM.../TONIGHT THROUGH TUESDAY NIGHT/ A LINE OF SHOWERS AND THUNDERSTORMS CONTINUES TO WORK SOUTHEAST ACROSS THE AREA. HAVE HAD NUMEROUS REPORTS OF PEA SIZE HAIL WITH THE STRONGER STORMS. LOW WET BULB ZERO LEVELS ARE HELPING TO PRODUCE THE HAIL. LAPS AND RUC DATA SHOW CAPES AROUND 500 TO 750 J/KG...WITH LI/S -1 TO -3. THE LINE SHOULD BE JUST ABOUT OUT OF THE AREA AROUND 4 PM. CANNOT RULE OUT AN ADDITIONAL ISOLATED SHOWER OR THUNDERSTORM REDEVELOPING ALONG A VORT MAX MOVING THROUGH THIS EVENING. MODELS HINT AT A SUBTLE FEATURE WITH SOME WEAK OMEGA THIS EVENING...SO WILL KEEP SOME ISOLATED SHOWERS OR STORMS IN THE FORECAST THIS EVENING. SKIES SHOULD BEGIN TO CLEAR OUT TOWARDS MIDNIGHT AND AFTER...AND WILL LIKELY SEE VALLEY FOG DEVELOPING. THE NEXT SYSTEM APPROACHES FOR MONDAY AFTERNOON AND MONDAY NIGHT. GOOD DYNAMICS ARE ASSOCIATED WITH THIS SYSTEM. QUITE A DIFFERENCE IN STRENGTH BETWEEN THE WRF AND GFS. SIDED CLOSE TO THE STRONGER GFS...WHICH IS ALSO IN AGREEMENT WITH THE SREF AND NGM. WILL GO WITH LIKELY POPS ACROSS MUCH OF THE AREA LATE MONDAY...AND CONTINUE THOSE INTO MONDAY NIGHT. SOME ELEVATED INSTABILITY IS ALSO NOTED...AS SHOWALTERS DROP TO -1. IF THIS INSTABILITY IS REALIZED...THE STRONG SHEAR COULD RESULT IN STRONG THUNDERSTORMS. THIS SYSTEM WILL BEGIN TO EXIT TUESDAY...AND WILL MAINTAIN HIGH CHANCE POPS IN THE MORNING. A SECONDARY SURFACE TROF DROPS SOUTHEAST ACROSS THE AREA LATE TUESDAY INTO TUESDAY NIGHT...AND WILL INCLUDE A CHANCE OF SHOWERS AS THIS FEATURE MOVES THROUGH. .LONG TERM.../WEDNESDAY THROUGH SUNDAY/ THE MODELS HAVE TRENDED TO A SLIGHTLY MORE CONSISTENT SOLUTION IN THE LONG TERM. THE LARGE SCALE PATTERN WILL FEATURE LONG WAVE TROFS OVER BOTH THE EASTERN AND WESTERN CONUS...WITH A STRENGTHENING RIDGE IN THE CENTRAL CONUS. ON WEDNESDAY...A VORT MAX SHOULD BE MOVING JUST NORTHEAST OF THE AREA. WILL KEEP THE FORECAST DRY...AS IT LOOKS LIKE THE BEST CHANCE FOR PRECIP WILL BE FURTHER TO THE NORTHEAST OF OUR CWA. BY THURSDAY...MOISTURE TRIES TO SLIDE SOUTHEAST ALONG THE NORTHERN SIDE OF A STATIONARY FRONT LOCATED FROM A SURFACE LOW OVER COLORADO...TO THE SOUTHEASTERN CONUS. WILL MENTION CHANCE POPS FOR SHOWERS THURSDAY AND THURSDAY NIGHT...TAPERING OFF TO SLIGHT CHANCE FRIDAY MORNING AS THE MOISTURE EXITS AND H5 RIDGING STRENGTHENS. WITH THE FRONT WELL TO THE SOUTH OF THE CWA AND INSTABILITY LACKING...WILL NOT MENTION THUNDER. FROM LATER FRIDAY ON THROUGH SUNDAY...WILL KEEP THE FORECAST DRY WITH GRADUALLY WARMING TEMPERATURES AS RIDGING AT H5 AND THE SURFACE BUILDS IN. THE GFS IS FURTHER EAST WITH THE H5 RIDGING...AND BUILDS WARMER AIR IN QUICKER THAN THE ECMWF. THE TREND THE PAST FEW DAYS HAS BEEN FOR A SLOWER RETURN OF WARM AIR...AND WITH THE BETTER RUN TO RUN CONSISTENCY OF THE ECMWF...WENT A LITTLE COOLER THAN GFS MOS. STARTED WITH HPC TEMPERATURE GUIDANCE AND MADE SOME ADJUSTMENTS FROM THERE AGAIN TODAY. && .AVIATION.../00Z TO 24Z/...UPDATED ISOLATED SHOWERS REMAIN A POSSIBILITY FROM JKL NORTH FOR THE NEXT COUPLE OF HOURS BEFORE THE SUN GOES DOWN AND THE ATMOSPHERE STABILIZES. OTHERWISE... FOG IS THE MAIN PROBLEM WITH THIS ISSUANCE. DECIDED TO TREND MORE OPTIMISTIC WITH VSBYS/CIGS LATER TONIGHT AS RAINFALL WAS NOT THAT WIDESPREAD. MIXING BEHIND THE FRONT HAS ALSO ALLOWED THE LOW LEVELS TO DRY OUT QUITE WELL. WITH THAT SAID... IFR VSBYS LATER TONIGHT REMAIN LIKELY IN THE RIVER VALLEYS AND FOR LOCATIONS LIKE LOZ WHICH RECEIVED SOME GOOD RAINFALL EARLIER. NEXT SYSTEM ARRIVES LATE TOMORROW WITH A RETURN OF SHOWERS AND THUNDERSTORMS BUT COVERAGE IS QUESTIONABLE SO BELIEVE A VCTS MENTION WITH VFR CIGS/VSBYS WILL SUFFICE AT THIS TIME. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...WJM LONG TERM....WJM AVIATION...ABE ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 254 PM EDT SUN MAY 18 2008 .SHORT TERM.../TONIGHT THROUGH TUESDAY NIGHT/...UPDATED A LINE OF SHOWERS AND THUNDERSTORMS CONTINUES TO WORK SOUTHEAST ACROSS THE AREA. HAVE HAD NUMEROUS REPORTS OF PEA SIZE HAIL WITH THE STRONGER STORMS. LOW WET BULB ZERO LEVELS ARE HELPING TO PRODUCE THE HAIL. LAPS AND RUC DATA SHOW CAPES AROUND 500 TO 750 J/KG...WITH LI/S -1 TO -3. THE LINE SHOULD BE JUST ABOUT OUT OF THE AREA AROUND 4 PM. CANNOT RULE OUT AN ADDITIONAL ISOLATED SHOWER OR THUNDERSTORM REDEVELOPING ALONG A VORT MAX MOVING THROUGH THIS EVENING. MODELS HINT AT A SUBTLE FEATURE WITH SOME WEAK OMEGA THIS EVENING...SO WILL KEEP SOME ISOLATED SHOWERS OR STORMS IN THE FORECAST THIS EVENING. SKIES SHOULD BEGIN TO CLEAR OUT TOWARDS MIDNIGHT AND AFTER...AND WILL LIKELY SEE VALLEY FOG DEVELOPING. THE NEXT SYSTEM APPROACHES FOR MONDAY AFTERNOON AND MONDAY NIGHT. GOOD DYNAMICS ARE ASSOCIATED WITH THIS SYSTEM. QUITE A DIFFERENCE IN STRENGTH BETWEEN THE WRF AND GFS. SIDED CLOSE TO THE STRONGER GFS...WHICH IS ALSO IN AGREEMENT WITH THE SREF AND NGM. WILL GO WITH LIKELY POPS ACROSS MUCH OF THE AREA LATE MONDAY...AND CONTINUE THOSE INTO MONDAY NIGHT. SOME ELEVATED INSTABILITY IS ALSO NOTED...AS SHOWALTERS DROP TO -1. IF THIS INSTABILITY IS REALIZED...THE STRONG SHEAR COULD RESULT IN STRONG THUNDERSTORMS. THIS SYSTEM WILL BEGIN TO EXIT TUESDAY...AND WILL MAINTAIN HIGH CHANCE POPS IN THE MORNING. A SECONDARY SURFACE TROF DROPS SOUTHEAST ACROSS THE AREA LATE TUESDAY INTO TUESDAY NIGHT...AND WILL INCLUDE A CHANCE OF SHOWERS AS THIS FEATURE MOVES THROUGH. .LONG TERM.../WEDNESDAY THROUGH SUNDAY/...UPDATED THE MODELS HAVE TRENDED TO A SLIGHTLY MORE CONSISTENT SOLUTION IN THE LONG TERM. THE LARGE SCALE PATTERN WILL FEATURE LONG WAVE TROFS OVER BOTH THE EASTERN AND WESTERN CONUS...WITH A STRENGTHENING RIDGE IN THE CENTRAL CONUS. ON WEDNESDAY...A VORT MAX SHOULD BE MOVING JUST NORTHEAST OF THE AREA. WILL KEEP THE FORECAST DRY...AS IT LOOKS LIKE THE BEST CHANCE FOR PRECIP WILL BE FURTHER TO THE NORTHEAST OF OUR CWA. BY THURSDAY...MOISTURE TRIES TO SLIDE SOUTHEAST ALONG THE NORTHERN SIDE OF A STATIONARY FRONT LOCATED FROM A SURFACE LOW OVER COLORADO...TO THE SOUTHEASTERN CONUS. WILL MENTION CHANCE POPS FOR SHOWERS THURSDAY AND THURSDAY NIGHT...TAPERING OFF TO SLIGHT CHANCE FRIDAY MORNING AS THE MOISTURE EXITS AND H5 RIDGING STRENGTHENS. WITH THE FRONT WELL TO THE SOUTH OF THE CWA AND INSTABILITY LACKING...WILL NOT MENTION THUNDER. FROM LATER FRIDAY ON THROUGH SUNDAY...WILL KEEP THE FORECAST DRY WITH GRADUALLY WARMING TEMPERATURES AS RIDGING AT H5 AND THE SURFACE BUILDS IN. THE GFS IS FURTHER EAST WITH THE H5 RIDGING...AND BUILDS WARMER AIR IN QUICKER THAN THE ECMWF. THE TREND THE PAST FEW DAYS HAS BEEN FOR A SLOWER RETURN OF WARM AIR...AND WITH THE BETTER RUN TO RUN CONSISTENCY OF THE ECMWF...WENT A LITTLE COOLER THAN GFS MOS. STARTED WITH HPC TEMPERATURE GUIDANCE AND MADE SOME ADJUSTMENTS FROM THERE AGAIN TODAY. && .AVIATION.../18Z TO 18Z/ THE ONLY WEATHER IN THE NEAR TERM IS A BAND OF SHOWERS AND THUNDERSTORMS THAT ARE DROPPING THROUGH FAR SOUTHEAST KENTUCKY JUST AHEAD OF THE COLD FRONT. WITH THESE CIGS WILL POTENTIALLY DROP INTO MVFR ALONG WITH THE VIS FOR A BRIEF TIME. OTHERWISE...VFR CONDITIONS WILL PREVAIL UNTIL LATER IN THE NIGHT WHEN CLEAR SKIES AND LIGHT VALLEY WINDS COMBINED WITH THE GROUND MOISTURE HELPS COALESCE WIDESPREAD VALLEY FOG...BELIEVE THE GRADIENT WINDS ON THE RIDGES WILL KEEP THEM CLEAR. THIS VALLEY FOG COULD GET DENSE FOR A TIME TOWARD DAWN. HAVE REFLECTED THIS IN THE TAFS FOR LOZ AND SME. THE FOG WILL CLEAR BY MID MORNING BEFORE A DECK OF CLOUDS AT AROUND 4K FEET DEVELOPS DURING THE AFTERNOON AHEAD OF THE NEXT QUICK HITTING SYSTEM. WINDS WILL BE GUSTY FROM THE NORTHWEST BEHIND THE FRONT FOR A TIME INTO EARLY EVENING. THESE WILL DIE OFF AND BECOME RELATIVELY LIGHT LATER TONIGHT...ESPECIALLY IN THE VALLEYS. THE WIND THEN PICKS UP AGAIN ON MONDAY TWISTING BACK TOWARD THE WEST AND EVENTUALLY SOUTHWEST BY MID AFTERNOON. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...WJM LONG TERM...WJM AVIATION...GREIF ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 1222 PM CDT SUN MAY 18 2008 .DISCUSSION... FRONTAL BOUNDARY WAS JUST SOUTH OF THE FA EARLY THIS AFTERNOON. DRIER AIR HAS FILTERED IN ON NW WINDS. DEW POINTS AND TEMPS ALL OVER THE PLACE...WITH DEEP VERTICAL MIXING WITHIN 15 TO 25 KTS OF FLOW SEEN ON LAPS AND RUC SOUNDINGS UP TO 750MB. WILL KEEP AN EYE ON CU MOVG SE ACROSS INDIANA AND ILLINOIS. A VORT PASSING JUST NE OF THE REGION ENHANCING THE CU...COULD RESULT IN WK ISOLD CONVECTION. THINK THE BETTER CHANCE IS OUT OF OUR CWFA TO OUR NE AND EAST...IF IT HAPPENS. EARLY TONIGHT...EXPECT WINDS TO GO LIGHT...WITH LINGERING AFTERNOON CU DISSIPATING. WEAK SURFACE RIDGE WILL MOVE ACROSS THE AREA TONIGHT...WITH WINDS QUICKLY RESPONDING SSE TO NEXT SYSTEM UPSTREAM TOWARD MORNING. SURFACE LOW WILL MOVE FROM NE KANSAS INTO CENTRAL MISSOURI FROM 12-18Z...WITH INCREASING MID AND UPPER LEVEL MOISTURE/CLOUDS AHEAD OF IT. WILL CONTINUE WITH OUR CHANCE POPS...ACROSS MAINLY THE NORTHERN 1/2 OF THE FA MONDAY...THEN TRANSITION POPS SOUTHWARD MONDAY NIGHT THROUGH TUESDAY AS THE SURFACE WAVE PASSES ACROSS THE REGION THEN DRAGS ANOTHER FRONT THROUGH THE AREA. EXPECT GENERALLY DRY CONDITIONS FOR MOST OF TUESDAY NIGHT AS DRIER AIR WORKS INTO THE REGION UPON WEAK SURFACE RIDGING. GFS AND SREF GUIDANCE WAS IN GOOD AGREEMENT THUS USED A BLEND OF BOTH MODELS FOR POPS/WX AND WINDS. NUMERICAL GUIDANCE WAS MOSTLY A BLEND OF MAV AND MET FOR TEMPS. FOR DAYS 4 THROUGH 7...FAVOR A BLEND OF THE 06Z GFS ALONG WITH THE 00Z ECMWF...AND HPC/S SLANT TOWARD THE NCEP ENSEMBLE MEAN. SEE THE PREEPD FOR ADDITIONAL INFO. IN A NUTSHELL...A GRADUAL LONGITUDINAL SHIFT EASTWARD IS EXPECTED WITHIN THE AMPLIFIED MID TROPOSPHERIC FLOW PATTERN. BY MID WEEK...A MID LEVEL RIDGE IS FORECAST TO SET UP ACROSS THE CENTRAL U.S. WITH A DEVELOPING TROF/LOW OVER THE WEST U.S. AND A PERSISTENT TROF OVER THE EAST. THIS PATTERN FROM WEDNESDAY THROUGH SUNDAY IS EXPECTED TO CHANGE LITTLE ONCE IT BECOMES ESTABLISHED...AS THE MODELS DIG THE WEST TROF INTO SOME ASSEMBLANCE OF A CUTOFF LOW OR ELONGATED TROF...STRENGTHENING THE CENTRAL U.S. RIDGE. AT THE SURFACE...A QUASI-STATIONARY FRONTAL BOUNDARY IS FORECAST TO REMAIN JUST SOUTH OF THE AREA. HOWEVER MID LEVEL ENERGY IS FORECAST TO TOP THE H7/H5 RIDGE AND ACT UPON SOME ELEVATED MOISTURE. THUS WE WILL LIKELY CARRY SOME POPS FOR CONVECTION WEDNESDAY NIGHT THROUGH FRIDAY. THINK HPC AND THE ECMWF SHOWING A FARTHER SOUTH AXIS OF SLIGHTLY HIGHER POPS IS MORE CORRECT THAN MOSGUIDE AND THE GFS...PLACING THE ACTIVITY ALONG AND JUST NORTH OF THE SURFACE FRONTAL BOUNDARY. SATURDAY INTO SUNDAY...THE CENTRAL RIDGE STRENGTHENS AND MOVES SLIGHTLY TO THE EAST. A LARGE DOME OF HIGH PRESSURE IS FORECAST TO COVER MUCH OF THE EAST 1/2 OF THE CONUS. THE HIGH WILL DRIVE SLIGHTLY DRIER AIR INTO THE REGION AND SUPPRESS THE FRONTAL BOUNDARY TO OUR SOUTH. WITH DRIER AIR TIED TO THE MID LEVEL RIDGE...WE EXPECT GENERALLY DRY CONDITIONS FROM FRIDAY NIGHT THROUGH SUNDAY. USED A BLEND OF EXISTING FORECAST NUMBERS AND LATEST HPC GUIDANCE FOR TEMPS. && .AVIATION... GUSTY WEST TO NORTHWEST WINDS WILL BE POSSIBLE THIS AFTERNOON...IN THE 20 TO 25 KT RANGE. THE WINDS SHOULD SUBSIDE QUICKLY WITH SUNSET...THEN TURN TO THE SSE AROUND 12Z. A FEW CU AND SOME HIGH CLOUDS CANNOT BE RULED OUT. ESSENTIALLY VFR CIGS AND VSBYS TODAY THROUGH TONIGHT. COULD BE SOME MID CLOUDS AFTER MIDNIGHT AS WELL. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 1245 PM EDT SUN MAY 18 2008 .MORNING UPDATE... UPDATED FORECAST TO REFLECT CLEARING TRENDS AND EXITING PRECIPITATION. A WEAK LINE OF SHOWERS ACROSS SOUTHERN KENTUCKY WILL EXIT INTO TENNESSEE BY LATE MORNING. SKIES HAVE CLEARED ACROSS CENTRAL AND NORTHERN KENTUCKY AND SOUTHERN INDIANA. SURFACE ANALYSIS SHOWS A COLD FRONT LOCATED ALONG THE BACK EDGE OF THE PRECIPITATION. RIGHT NOW IT IS MARKED BY A WIND SHIFT LINE SOUTHEAST OF THE OHIO RIVER. NORTHWEST WINDS WILL INCREASE TO AROUND 15 MPH THIS AFTERNOON WITH SOME HIGHER GUSTS. CLOUDS WILL BE A CHALLENGE THIS AFTERNOON. COLDER AIR AT 700MB WILL MOVE SOUTH TOWARDS THE AREA. WHILE SURFACE HEATING WILL WARM TEMPS THIS AFTERNOON...LAPSE RATES WILL STEEPEN. THE MESO-NAM REFLECTS THIS IN ITS FORECAST OF SURFACE BASED LI`S FALLING TO -2 OR -3. EXPECT AT SOME POINT THIS AFTERNOON...THAT CU WILL DEVELOP QUICKLY...ESPECIALLY ACROSS SOUTHEAST INDIANA AND THE BLUEGRASS. SCATTERED SHOWERS MAY ACTUALLY FORM...WITH THE GREATEST CONCENTRATION ACROSS THE BLUEGRASS AND SOUTHERN INDIANA. && .SHORT TERM (TODAY AND TONIGHT)... SEVERAL BANDS OF SHOWERS HAVE OR WILL BE MOVING ACROSS SOUTH CENTRAL INDIANA AND CENTRAL KENTUCKY DURING THE OVERNIGHT AND MORNING HOURS TODAY. ONE BAND WAS LOCATED OVER SOUTH CENTRAL KENTUCKY AT 0630Z WHILE THE SECOND BAND WILL MOVE ACROSS THE FA BEFORE MORNING. THIRD BAND WAS MOVING SOUTH ACROSS THE NORTHERN PARTS OF ILLINOIS AND INDIANA AND HAD LIGHT SHOWERS WITH IT...MORE SPOTTY OVER ILLINOIS, THE FORECAST PROBLEM FOR THIS MORNING IS WILL THIS NEXT BAND OF SHOWERS/CLOUDS HOLD TOGETHER AS IT DROPS SOUTH INTO THE LOWER OHIO VALLEY. NAM IS DRY WITH THIS SYSTEM AS IT HAD BEEN WITH THE TWO BANDS OF SHOWERS ARE OVER THE AREA NOW - BELIEVE NAM IS NOT PICKING UP ENOUGH ON THIS SYSTEM. RUC PICKS UP THE SECOND BAND OF PRECIPITATION BUT HAS LITTLE AFTER 12Z. GFS SHOWS THE MOST MOISTURE AND WILL LEAN TOWARD A BLEND OF GFS AND RUC FOR PRECIPITATION FORECAST. THE SCATTERED SHOWERS WITH THE SECOND BAND WILL CONTINUE UNTIL CLOSE TO 12Z...AND PAST 12Z ACROSS THE SOUTH. THE THIRD BAND IS THE DRIEST AND IS OCCURRING BEHIND THE FRONT. IT WILL HAVE SOME MID LEVEL INSTABILITY FROM COLDER AIR ALOFT BUT THE AIR IN THE LOWER LEVELS IS DRY. WILL MENTION SMALL CHANCE THROUGH THE MORNING HOURS THEN DECREASING POPS IN THE AFTERNOON OVER THE EAST. THE HIGHER POPS WILL BE OVER EAST WITH ONLY ISOLATED IN THE WEST AS THE DRIER AIR WORKS ITS WAY INTO THE LOWER OHIO VALLEY. CLOUDS WILL PERSIST THIS AFTERNOON WITH A BAND OF MID LEVEL MOISTURE MOVING THROUGH THE AREA...THEN CLOUDS WILL DECREASE OVERNIGHT. TEMPERATURES THIS AFTERNOON WILL BE SEVERAL DEGREES COOLER THAN SATURDAY WITH TEMPERATURES TONIGHT IN THE 40S TO AROUND 50. .LONG TERM (MONDAY THROUGH SATURDAY)... MONDAY-WEDNESDAY... A BROAD AND UNUSUALLY DEEP TROUGH OVER THE EASTERN UNITED STATES WILL REMAIN IN PLACE DURING THIS FORECAST PERIOD. ANOTHER IN A SERIES OF JET STREAKS WILL DROP INTO THE BASE OF THE TROUGH WHICH WILL SERVE TO SHARPEN IT UP AND BRING A SURFACE LOW OUT OF CENTRAL CANADA INTO THE LOWER OHIO VALLEY BY TUESDAY MORNING. CURRENT FORECAST IS ON TRACK BUT WE WILL UP POPS FOR THE MONDAY AFTERNOON INTO TUESDAY MORNING TIME FRAME. THE BEST INSTABILITY REMAINS ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA AND WE WILL CONTINUE TO MENTION THUNDER ACROSS THIS AREA. THE WARMEST DAY WILL BE TUESDAY EVEN WITH THE EXPECTED CLOUD COVER AND RAIN CHANCES. A BACKING WIND IN ADVANCE OF THE APPROACHING LOW WILL BRING A WARM WESTERLY FLOW INTO THE REGION. THURSDAY-SATURDAY... BY THURSDAY...THE RIDGING FINALLY REACHES THE CENTRAL PLAINS WITH A SFC LOW DEVELOPING THERE TOO. ENSEMBLES AND OPS GFS TRY TO GENERATE WARM FRONTAL PRECIP FROM THIS LOW OVER OUR AREA FROM THURSDAY INTO FRIDAY. WITH THOSE MODELS IN AGREEMENT WITH HPC...WENT AHEAD AND INCLUDED SLIGHT TO LOW CHC POPS DURING THAT TIME FRAME. HOWEVER THE EURO DOES NOT KEEP THIS PRECIP OVER THE AREA...SO SOMETHING TO WATCH THE NEXT COUPLE OF DAYS. THE WARM UP LOOKS TO BE DELAYED BECAUSE OF THE SLOW EASTWARD MOVEMENT OF THE RIDGE. SO WENT NEAR ENSEMBLE MOS VALUES FOR HIGHS AND LOWS LATE NEXT WEEK...HIGHS GENERALLY IN THE UPPER 70S WITH LOWS IN THE 50S. THINK THE MID 80 HIGHS MAY HOLD OFF UNTIL LATE NEXT WEEKEND. && .AVIATION (18Z TAFS)... COOLER AIR WILL ARRIVE THIS AFTERNOON. NORTHWEST WINDS WILL INCREASE BY 19Z TO AROUND 15 MPH...WITH GUSTS UP TO 25 MPH. EXPECT WIDESPREAD CU TO DEVELOP THIS AFTERNOON...ESPECIALLY ACROSS THE BLUEGRASS REGION. SKIES MAY BECOME BROKEN AT TIMES BETWEEN 20Z AND 00Z AT LEX. WITH STEEPENING LOW LEVEL LAPSE RATES...ISOLATED SHOWERS MAY DEVELOP SDF AND LEX AFTER 21Z AS WELL. CIGS WILL STAY VFR EXCEPT WITHIN ONE OF THESE WIDELY SCATTERED SHOWERS. SKIES WILL TREND TOWARDS CLEARING AFTER 02Z AND STAY MOSTLY CLEAR THROUGH EARLY AFTERNOON MONDAY. NORTHWEST WINDS WILL DIMINISH QUITE A BIT TOWARDS 10Z...AND MAY BECOME NEARLY CALM BY 12Z. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ SHORT TERM...JSD LONG TERM....MJ AVIATION.....JSD ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 724 AM EDT SUN MAY 18 2008 .SHORT TERM (TODAY AND TONIGHT)... SEVERAL BANDS OF SHOWERS HAVE OR WILL BE MOVING ACROSS SOUTH CENTRAL INDIANA AND CENTRAL KENTUCKY DURING THE OVERNIGHT AND MORNING HOURS TODAY. ONE BAND WAS LOCATED OVER SOUTH CENTRAL KENTUCKY AT 0630Z WHILE THE SECOND BAND WILL MOVE ACROSS THE FA BEFORE MORNING. THIRD BAND WAS MOVING SOUTH ACROSS THE NORTHERN PARTS OF ILLINOIS AND INDIANA AND HAD LIGHT SHOWERS WITH IT...MORE SPOTTY OVER ILLINOIS, THE FORECAST PROBLEM FOR THIS MORNING IS WILL THIS NEXT BAND OF SHOWERS/CLOUDS HOLD TOGETHER AS IT DROPS SOUTH INTO THE LOWER OHIO VALLEY. NAM IS DRY WITH THIS SYSTEM AS IT HAD BEEN WITH THE TWO BANDS OF SHOWERS ARE OVER THE AREA NOW - BELIEVE NAM IS NOT PICKING UP ENOUGH ON THIS SYSTEM. RUC PICKS UP THE SECOND BAND OF PRECIPITATION BUT HAS LITTLE AFTER 12Z. GFS SHOWS THE MOST MOISTURE AND WILL LEAN TOWARD A BLEND OF GFS AND RUC FOR PRECIPITATION FORECAST. THE SCATTERED SHOWERS WITH THE SECOND BAND WILL CONTINUE UNTIL CLOSE TO 12Z...AND PAST 12Z ACROSS THE SOUTH. THE THIRD BAND IS THE DRIEST AND IS OCCURRING BEHIND THE FRONT. IT WILL HAVE SOME MID LEVEL INSTABILITY FROM COLDER AIR ALOFT BUT THE AIR IN THE LOWER LEVELS IS DRY. WILL MENTION SMALL CHANCE THROUGH THE MORNING HOURS THEN DECREASING POPS IN THE AFTERNOON OVER THE EAST. THE HIGHER POPS WILL BE OVER EAST WITH ONLY ISOLATED IN THE WEST AS THE DRIER AIR WORKS ITS WAY INTO THE LOWER OHIO VALLEY. CLOUDS WILL PERSIST THIS AFTERNOON WITH A BAND OF MID LEVEL MOISTURE MOVING THROUGH THE AREA...THEN CLOUDS WILL DECREASE OVERNIGHT. TEMPERATURES THIS AFTERNOON WILL BE SEVERAL DEGREES COOLER THAN SATURDAY WITH TEMPERATURES TONIGHT IN THE 40S TO AROUND 50. .LONG TERM (MONDAY THROUGH SATURDAY)... MONDAY-WEDNESDAY... A BROAD AND UNUSUALLY DEEP TROUGH OVER THE EASTERN UNITED STATES WILL REMAIN IN PLACE DURING THIS FORECAST PERIOD. ANOTHER IN A SERIES OF JET STREAKS WILL DROP INTO THE BASE OF THE TROUGH WHICH WILL SERVE TO SHARPEN IT UP AND BRING A SURFACE LOW OUT OF CENTRAL CANADA INTO THE LOWER OHIO VALLEY BY TUESDAY MORNING. CURRENT FORECAST IS ON TRACK BUT WE WILL UP POPS FOR THE MONDAY AFTERNOON INTO TUESDAY MORNING TIME FRAME. THE BEST INSTABILITY REMAINS ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA AND WE WILL CONTINUE TO MENTION THUNDER ACROSS THIS AREA. THE WARMEST DAY WILL BE TUESDAY EVEN WITH THE EXPECTED CLOUD COVER AND RAIN CHANCES. A BACKING WIND IN ADVANCE OF THE APPROACHING LOW WILL BRING A WARM WESTERLY FLOW INTO THE REGION. THURSDAY-SATURDAY... BY THURSDAY...THE RIDGING FINALLY REACHES THE CENTRAL PLAINS WITH A SFC LOW DEVELOPING THERE TOO. ENSEMBLES AND OPS GFS TRY TO GENERATE WARM FRONTAL PRECIP FROM THIS LOW OVER OUR AREA FROM THURSDAY INTO FRIDAY. WITH THOSE MODELS IN AGREEMENT WITH HPC...WENT AHEAD AND INCLUDED SLIGHT TO LOW CHC POPS DURING THAT TIME FRAME. HOWEVER THE EURO DOES NOT KEEP THIS PRECIP OVER THE AREA...SO SOMETHING TO WATCH THE NEXT COUPLE OF DAYS. THE WARM UP LOOKS TO BE DELAYED BECAUSE OF THE SLOW EASTWARD MOVEMENT OF THE RIDGE. SO WENT NEAR ENSEMBLE MOS VALUES FOR HIGHS AND LOWS LATE NEXT WEEK...HIGHS GENERALLY IN THE UPPER 70S WITH LOWS IN THE 50S. THINK THE MID 80 HIGHS MAY HOLD OFF UNTIL LATE NEXT WEEKEND. && .AVIATION (12Z TAFS)... VFR CONDITIONS EXPECTED TO CONTINUE AT TAF SITES FOR MOST OF THE PERIOD. THE LAST IN A SERIES OF BANDS OF CLOUDS AND SHOWERS WAS DROPPING SOUTH ACROSS SOUTH CENTRAL INDIANA AND CENTRAL KENTUCKY AT 1030Z. THESE SHOWERS WERE OCCURRING ALONG AND AHEAD OF COLD FRONT THAT WILL SWEEP ACROSS THE AREA TODAY. THE SHOWERS WERE BECOMING MORE SPOTTY AND THE BAND OF SHOWERS WILL LIE SOUTH OF SDF AND LEX BY 12Z. AS COOLER AIR BEHIND THE FRONT SPREADS INTO THE LOWER OHIO VALLEY THIS AFTERNOON...EXPECT TO SEE SOME CLOUDS DEVELOP BUT THESE CLOUDS SHOULD BE ABOVE 3 THSD FT. EXCEPT IN HEAVIER SHOWERS...VSBYS WILL BE UNRESTRICTED. THE CLOUDS WILL DECREASE OVERNIGHT. WINDS WILL BECOME GUSTY TODAY AND SHIFT TO THE NORTHWEST AFTER THE FRONT MOVES TO THE SOUTH. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ SHORT TERM...SCHOLZ LONG TERM....JA AVIATION.....SCHOLZ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1110 AM EDT SUN MAY 18 2008 .SYNOPSIS... A STRONG COLD FRONT WILL PUSH THROUGH THE AREA THIS AFTERNOON AND WILL BE ACCOMPANIED BY WIDESPREAD SHOWERS AND THUNDERSTORMS. ANOTHER AREA OF LOW PRES WILL PASS SOUTH OF THE AREA ON TUESDAY WITH MORE RAIN EXPECTED. COOLER THAN NORMAL TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WORK WEEK. RIDGE OF HIGH PRESSURE WILL BUILD TOWARD NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... COLD FRONT WAS MOVING INTO WEST VIRGINIA LATE THIS MORNING. HAVE A HEALTHY COVERAGE OF SHOWERS WEST OF THE BLUE RIDGE...ALTHOUGH LIGHTNING HAS BEEN RATHER SPARSE SO FAR. LITTLE IF ANY SHOWERS HAVE BEEN OBSERVED EAST OF THE MTNS. ACCORDING TO 12Z KIAD RAOB AND NCEP MODELS...ATMOSPHERE WILL HAVE A DECENT AMOUNT OF SHEAR TODAY BUT INSTABILITY WILL BE WEAK. RUC AND NAM FORECAST THE BEST INSTABILITY DEVELOPING EAST OF THE MTNS...POSSIBLY UP TO 500 J/KG. COMBINED WITH SHEAR...THIS COULD SUPPORT STRONG TO LOCALLY SEVERE STORMS EAST OF THE MTNS. 12Z LWX WRF-ARW IMPLIES THIS IN ITS SIMULATED REFLECTIVITY FIELDS...WITH LINE SEGMENTS POSSIBLY FORMING EAST OF THE MTNS DURING THE EARLY AFTERNOON. MAIN THREAT WILL BE FOR DAMAGING WINDS ALTHOUGH IF MORE INSTABILITY CAN DEVELOP...THEN A SMALL HAIL THREAT MAY EXIST AS WELL. HAVE ALREADY UPDATED GRIDS/PRODUCTS FOR MINOR ADJUSTMENTS BASED ON RADAR/MODEL TRENDS. CHANGES WERE MINIMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... CDFNT WILL EXIT THE AREA BETWEEN 21Z-00Z WITH PARTIAL CLEARING AND GUSTY WINDS BEHIND FROPA. SOME UPSLOPE RAIN SHOWERS POSSIBLE OVR THE HIGHLANDS. OTHERWISE...COOL OVERNIGHT WITH TEMPS BOTTOMING OUT IN THE MID TO UPPER 40S. && .LONG TERM /MONDAY THROUGH SATURDAY/... 500MB NORTHERN HEMISPHERIC HEIGHT/ANOMALY FOR THE PAST 5 DAYS INDICATES A PATTERN SHIFT...WITH A DEEP CENTRAL PACIFIC TROUGH...WESTERN CONUS RIDGE...AND A DEVELOPING EASTERN CANADIAN TROUGH. WATER VAPOR LOOP SHOWS THE NEXT WAVE ROTATING SOUTHEAST OVER THE MIDWEST...AROUND AN UPPER LOW CENTERED NORTH OF THE GREAT LAKES. 03Z SURFACE MAP SHOWS A 999MB SURFACE LOW IN CENTRAL ILLINOIS...ALONG THE NEXT FRONTAL BOUNDARY. GUSTY WNW WINDS PERSIST THROUGH MONDAY BEHIND THIS AFTERNOONS COLD FRONTAL PASSAGE. NEXT OPPORTUNITY FOR PRECIPITATION IS LATE MONDAY NIGHT AND TUESDAY WITH THE NEXT WAVE ROTATING AROUND THE TROUGH. GLOBAL MODELS INDICATE ANOTHER CHANCE WEDNESDAY...BEFORE THE BAROCLINIC ZONE BEGINS TO SLIDE TO THE SOUTH THURSDAY. UPPER LEVEL RIDGE BUILDS IN GRADUALLY NEXT WEEKEND...PRESENTING A WARMING TREND AND DRY CONDITIONS. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... -SHRA AT KMRB THROUGH 18Z...THEN -SHRA/-TSRA AT REMAINING TERMINALS FROM 17Z-21Z. COLD FRONT MOVES THROUGH THEREAFTER...WITH GUSTY NW WINDS POST FROPA. GUSTY WNW WINDS EXPECTED WITH THE FRONTAL PASSAGE THROUGH MONDAY. CHANCE OF MVFR CEILINGS TUESDAY WITH RAIN AS THE NEXT WAVE PASSES THROUGH. && .MARINE... WINDS OVER THE WATERS WILL CONTINUE INCREASE THROUGH THIS AFTERNOON. SCA IN EFFECT. WILL HAVE TO WATCH FOR HIGHER WINDS /SMW CALIBER/ IN THUNDERSTORMS THIS AFTERNOON. SMALL CRAFT ADVISORY WINDS WITH THE FRONTAL PASSAGE THROUGH MONDAY EVENING. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT MONDAY FOR ANZ530>537. && $$ SYNOPSIS...BPP NEAR TERM...BPP SHORT TERM...LFR LONG TERM...SJR AVIATION...BPP/SJR MARINE...BPP/SJR md AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE MARQUETTE MI 155 PM EDT MON MAY 19 2008 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE TEMPERATURE POTENTIAL TODAY AND TONIGHT. WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OVER EASTERN CANADA. A WEAK SHORTWAVE ROTATING THROUGH THE BASE OF THIS TROUGH IS OVER WESTERN U.P. OTHER SHORTWAVES SLIDING DOWN THE LEE OF A SOUTHWEST CANADA RIDGE ARE OVER MINNESOTA AND SOUTH CENTRAL CANADA. SURFACE ANALYSIS DEPICTS A DEEP LOW OVER QUEBEC...A RIDGE OVER THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN ONTARIO. A PAIR OF LOWS ARE OVER CENTRAL PLAINS AND NORTHERN PLAINS. A COLD FRONT EXTENDS FROM THE NORTHERN LOW OVER SOUTHEAST SASKATCHEWAN NORTHWEST INTO CENTRAL ALBERTA. THE LONGWAVE TROUGH WILL REMAIN OVER QUEBEC TODAY. THE WEAK SHORTWAVE OVER THE AREA WILL SLIDE ACROSS THE U.P. THE SURFACE RIDGE WILL SLIDE INTO THE OHIO RIVER VALLEY WHILE THE NORTHERN PART REMAINS OVER THE UPPER MISSISSIPPI RIVER VALLEY. DRY AIR IN THE LOW LEVELS WILL BLANKET THE AREA. THUS EXPECTING MOSTLY SUNNY SKIES TO PREVAIL. UNDER AN INCREASE IN SUNSHINE OVER THE AREA TODAY...TEMPERATURES WILL PUSH TO AROUND 60 WEST AND MID 50S EAST AND OVER THE KEWEENAW PENINSULA WHERE A FEW LINGERING CLOUDS WILL LIMIT HEATING. A COUPLET OF LOW PRESSURE CENTERS WILL ROTATE WITHIN THE LONGWAVE TROUGH OVER EASTERN CANADA TONIGHT. WEAK SHORTWAVES ROTATING THROUGH THE BASE OF THIS TROUGH WILL SWEEP THROUGH THE FORECAST AREA. AT THE SURFACE A WEAK TROUGH ALSO SWINGING THROUGH THE BASE OF THE LOW OVER QUEBEC WILL SWEEP THROUGH THE FORECAST AREA. GUIDANCE CONTINUE TO SHOW THE DEEP MOISTURE TO THE NORTHEAST OF THE FORECAST AREA. LITTLE CHANGE IN THE WEATHER PATTERN OVER THE FORECAST AREA WILL CONTINUE THROUGH TUESDAY. SKIES WILL REMAIN MOSTLY CLEAR UNDER THE DRY CONDITIONS. WINDS WILL ALSO BE LIGHT...LIMITING LOW LEVEL MIXING. SINCE THERE WILL A LITTLE MORE SURFACE HEATING DURING THE DAY TODAY AND A LITTLE MORE CLOUD COVER TONIGHT WITH THE SHORTWAVE SWEEP THROUGH...CHANCES ARE THE OVERNIGHT TEMPERATURES WILL BE SEVERAL DEGREES WARMER THAN THIS MORNING. THERE IS STILL A POTENTIAL FOR PATCHY FROST ESPECIALLY IN LOW LYING AREAS. IT IS QUESTIONABLE WHETHER IT WILL BE WIDESPREAD ENOUGH TO WARRANT AN ADVISORY. THUS WILL HOLD OFF FOR NOW ON AN ADVISORY AND SEE REEVALUATE LATER TODAY. THE 00Z MODELS CONTINUE TO BE IN A FAIRLY GOOD AGREEMENT THROUGH DAY 3. ANOTHER SHORTWAVE TROUGH ROTATING AROUND THE NEARLY STATIONARY QUEBEC LOW WILL SWEEP THROUGH THE FORECAST AREA TUESDAY NIGHT. DEEP MOISTURE AREA WILL SLIDE INTO EASTERN AND NORTHERN ONTARIO. HOWEVER...CONDITIONS APPEAR TO REMAIN FAIRLY DRY IN THE LOW LEVELS OVER THE FORECAST AREA ESPECIALLY WITH THE APPROACH OF THE THE RIDGE OVER THE UPPER MISSISSIPPI RIVER VALLEY. ONLY AREAS OVER THE FAR EAST COULD GET A FEW SCATTERED SHOWERS. LITTLE CHANGE IN THE WEATHER PATTERN EXPECTED THROUGH WEDNESDAY. THE AREA OVER THE FAR EASTERN PART OF THE U.P. WILL CONTINUE TO BE VULNERABLE TO A SLIGHT CHANCE OF SHOWERS EVEN THROUGH WEDNESDAY. THUS WILL KEEP A SLIGHT CHANCE GOING. MEANWHILE THE MID LEVEL RIDGE WILL SHIFT INTO CENTRAL CANADA RUNNING UP AGAINST THE STATION LONGWAVE TROUGH OVER QUEBEC. ANOTHER LOW WILL DIG OVER THE PACIFIC NORTHWEST AND SOUTHERN BRITISH COLUMBIA. THE SURFACE RIDGE WILL SHIFT INTO THE WEST END OF UPPER MICHIGAN WHILE THE MID LEVEL RIDGE SHIFT ONLY INTO THE EASTERN DAKOTAS. DRY AIR WILL REMAIN IN PLACE OVER THE AREA KEEP CONDITIONS DRY THROUGH FRIDAY. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... EXPECT VFR CONDITIONS THROUGHOUT THIS TAF PACKAGE. A BKN LAYER AROUND 5-6 KFT THAT FORMED SOUTHWEST OF LAKE NIPIGON IS MOVING SOUTHEAST TOWARD THE KEWEENAW...EXPECT THIS DECK TO REACH CMX AROUND 00Z AND SAW A BIT LATER AND THEN DISSIPATE BEFORE SUNRISE. LAKE SUPERIOR LAKE BREEZE HAS MOVED INTO SAW...THIS SHOULD LAST FOR THE NEXT 4 TO 6 HOURS BEFORE WINDS BECOME NORTHWESTERLY AGAIN AND DIMINISH. WINDS WILL PICKUP TOMORROW AFTERNOON AS WEAK TROUGH PASSES OVER UPPER MICHIGAN LATE IN THE MORNING ON TUESDAY. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... OTHER THAN AN INCREASE IN WINDS TO 25 KT LATE TUE NIGHT INTO WED OVER ERN LAKE SUPERIOR IN THE WAKE OF A COLD FRONT...EXPECT HIGH PRESSURE TO DOMINATE THE UPPER GREAT LAKES REGION THROUGH MUCH OF THE WEEK. THE END RESULT WILL GENERALLY BE A WEAK PRES GRADIENT AND WINDS LESS THAN 25 KT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ DISCUSSION...DLG AVIATION...PEARSON MARINE...JV mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 110 PM EDT SUN MAY 18 2008 UPDATED FOR THE 18Z TAF ISSUANCE .UPDATE (ISSUED AT 1009 AM)... UPDATED GRIDS AND ZFP TO INCLUDE A SLIGHT CHANCE OF RAIN AND SNOW SHOWERS WHERE DENSE CLOUDS HAS SETTLED IN...MAINLY ACROSS THE WESTERN HALF OF UPPER MICHIGAN. TEMPERATURES WILL QUICKLY RISE TO ABOVE 38...WITH ONLY RAIN SHOWERS EXPECTED AFTER 1530Z. KMQT 88D RADAR REMAINS DOWN...AS TECHNICIANS AWAIT A PART THAT WILL BE ARRIVING THIS AFTERNOON. AT THIS TIME...THE RADAR IS EXPECTED TO BE BACK UP LATER TODAY. && .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST IS THE HIGH TEMPERATURE TODAY AND CHANCE OF FROST TONIGHT. WATER VAPOR IMAGERY AND RUC SHOWING A CLOSED LOW OVER EAST CENTRAL ONTARIO EMBEDDED IN A LONGWAVE TROUGH OVER CENTRAL CANADA. A LARGE RIDGE IS OVER THE CANADIAN PRAIRIES. WEAK SHORTWAVE IS SLIDING DOWN THE LEE OF THE RIDGE AND THROUGH THE FORECAST AREA. SURFACE ANALYSIS DEPICTS A COLD FRONT STRETCHING FROM A LOW OVER OHIO THROUGH THE CENTRAL PLAINS TO A LOW OVER ALBERTA. A RIDGE IS BUILDING OVER THE NORTHERN PLAINS. THE MID LEVEL RIDGE WILL MOVE INTO WESTERN MANITOBA TODAY PUSHING AGAINST THE LOW WHICH WILL REMAIN STATIONARY OVER EAST CENTRAL ONTARIO. A WEAK SHORTWAVE WILL SHIFT INTO WESTERN LAKE SUPERIOR. MEANWHILE...THE SURFACE RIDGE WILL SHIFT INTO THE MISSISSIPPI RIVER VALLEY. THE LOW OVER ALBERTA WILL SLIDE SOUTHEAST INTO SOUTHERN SASKATCHEWAN. FORECAST SOUNDINGS SUGGEST CUMULUS CLOUDS WILL DEVELOP OVER THE AREA...MAINLY OVER THE EASTERN U.P. BY NOON TODAY. A STRONG INVERSION AROUND 825MB WILL LIMIT DEVELOPMENT. IF ANY PRECIPITATION FALLS FROM THE CU...IT WILL DISSIPATE IN THE LOW LEVEL DRY AIR AS THE SOUNDINGS SHOWING A STRONG INVERTED V PATTERN EXCEPT OF THE EAST END OF THE CWA. THUS CLOUD COVER SHOULD LIMIT HEATING. TRAJECTORY FORECAST IS PULLING THE AIR MASS OVER CENTRAL ONTARIO INTO THE FORECAST AREA TODAY. THUS LOOKING FOR COOLER CONDITIONS TODAY. MOS DOES FAIRLY WELL UNDER THESE CONDITIONS SO WILL FOLLOW GUIDANCE. THE INVERTED V WOULD ALSO SUPPORT BREEZY CONDITIONS AGAIN TODAY. THE MID LEVEL LOW OVER ONTARIO WILL SHIFT INTO QUEBEC TONIGHT WHILE THE RIDGE OVER THE MISSISSIPPI RIVER VALLEY WILL START TO SHIFT INTO THE WESTERN U.P. DRY AIR WILL ALSO SHIFT INTO THE FORECAST AREA. THE LOW OVER SASKATCHEWAN WILL SHIFT INTO THE NORTHERN PLAINS WHILE EXPANDING INTO THE THE CENTRAL PLAINS. DRY AIR WILL REMAIN OVER THE AREA TONIGHT. THUS LOOKING FOR CLEARING. WINDS WILL ALSO DROP OFF. WITH THE LACK OF SURFACE HEATING TODAY DUE TO CLOUD COVER...LIGHTER WINDS UNDER THE RIDGE...AND CLEAR SKIES...CONDITIONS ARE FAVORABLE FOR SIGNIFICANT RADIATIONAL COOLING. THUS TEMPERATURE WILL DROP TO AROUND 29F OVER THE WEST AND LOW 30S EAST. A FROST ADVISORY IS IN ORDER. THE MID LEVEL RIDGE OVER MANITOBA WILL BREAKDOWN ON MONDAY WHILE THE WEST END OF THE RIDGE REMAINS OVER THE PACIFIC NORTHWEST. THE LOW OVER THE LOWER GREAT LAKES WILL SHIFT INTO QUEBEC. A SECONDARY LOW WILL DEVELOP AS A COUPLET WITH THE FIRST LOW AND WILL REACH JAMES BAY ON MONDAY. A WEAK SHORTWAVE WILL SLIDE DOWN THE LEE OF THE RIDGE AND THROUGH THE FORECAST AREA. ANOTHER WEAK SHORTWAVE WILL REACH NORTHERN MINNESOTA. SHOWERS AND A FEW THUNDERSTORMS WILL REACH JUST TO THE WEST OF THE FORECAST AREA. THE SHORTWAVE OVER MINNESOTA WILL SLIDE INTO THE WEST END OF THE FORECAST AREA MONDAY NIGHT. MODELS SHOWING MOST OF THE DEEP MOISTURE WILL SLIDE DOWN THE RIDGE AND MOVE ACROSS WISCONSIN INTO THE LOWER MICHIGAN. IN ASSOCIATION WITH THE SHORTWAVE A WEAK SURFACE LOW CENTER WILL ALSO SLIDE DOWN THE LEE OF THE RIDGE AND MOVE THROUGH WISCONSIN. THIS WILL BRING A CHANCE OF SHOWERS TO THE WEST END OF THE FORECAST AREA. A MID LEVEL RIDGE WILL BUILD OVER THE NORTHERN ROCKIES AND THE NORTHERN HIGH PLAINS...WHILE A SURFACE RIDGE BUILDS OVER CENTRAL CANADA AND PUSH INTO NORTHERN PLAINS. THE NORTHERN COUPLET THAT WAS OVER JAMES BAY WILL ROTATE INTO EAST CENTRAL ONTARIO ON TUESDAY. WEAK SHORTWAVES ROTATING AROUND THIS LOW WILL SWEEP THROUGH THE FORECAST AREA. DEEP MOISTURE ACCOMPANYING THE SHORTWAVES WILL REMAIN NORTH AND EAST OF THE FORECAST AREA. THUS PLAN TO KEEP THE HIGHER POPS OVER THE WESTERN AND SOUTHERN COUNTIES ONLY IN THE MORNING. AS DRY AIR MOVES BY LATE MORNING WILL LOW POPS FOR THE AFTERNOON. THE MID LEVEL LOW WILL SHIFT TO JUST NORTH OF GEORGIAN BAY TUESDAY NIGHT WHILE DIRECTING A WEAK SHORTWAVE THROUGH THE FORECAST AREA. THE RIDGE WILL MOVE OUT OF THE NORTHERN PLAINS TO THE UPPER MISSISSIPPI RIVER VALLEY. THE MID LEVEL RIDGE WILL SHIFT OVER THE NORTHERN PLAINS WHILE ANOTHER LOW DIGS OVER THE NORTHERN ROCKIES AND SOUTHWEST CANADA. THE MID LEVEL LOW WILL SETTLE OVER SOUTHEAST LOWER MICHIGAN ON WEDNESDAY. THE SURFACE RIDGE WILL SETTLE OVER THE FORECAST AREA. IN SPITE OF THE SHORTWAVES PASSING THROUGH THE AREA CONDITIONS WILL REMAIN DRY WITH SURFACE RIDGE REMAINING OVER THE AREA. THE SOUNDINGS CONTINUE TO SHOW DRY CONDITIONS OVER THE AREA. THE RIDGE WILL REMAIN OVER THE AREA THROUGH FRIDAY. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... PRECIPITATION HAS ALL BUT ENDED AT CMX...WITH THE POSSIBILITY REMAINING A LITTLE LONGER AT SAW UNDER BROKEN MVFR DECK. PRECIPITATION SHOULD REMAIN LIGHT AND NOT BE SNOW DUE TO TEMPS NOW ABOVE 40. EXPECT NORTH-NORTHWEST WIND GUSTS AROUND 25KTS TO DIMINISH TO AROUND 10KT OR LESS SHORTLY AFTER SUNSET...BEFORE PICKING UP AGAIN TO AROUND 20KT BY LATE MONDAY MORNING. FEW CLOUDS ANTICIPATED MONDAY...EXCEPT FOR SCT VARIETY AS SEEN UPSTREAM. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... CAA IN THE WAKE OF A FRONT WHICH MOVED THROUGH LAST NIGHT WILL CAUSE DECREASED STABILITY TODAY AS NORTHWEST WINDS WILL REACH 30 KT OVER THE CENTRAL AND EASTERN PORTIONS OF THE LAKE. A FEW GALE FORCE GUSTS ARE EVEN POSSIBLE FOR EASTERN PORTIONS. HIGH PRES WILL BUILD INTO THE AREA ON MON WITH DIMINISHING WINDS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/TONIGHT TO 8 AM EDT /7AM CDT/ MONDAY FOR MIZ001>007-009>015-084-085. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ UPDATE...KF DISCUSSION...DLG AVIATION...KF MARINE...VOSS mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1009 AM EDT SUN MAY 18 2008 .UPDATE... UPDATED GRIDS AND ZFP TO INCLUDE A SLIGHT CHANCE OF RAIN AND SNOW SHOWERS WHERE DENSE CLOUDS HAS SETTLED IN...MAINLY ACROSS THE WESTERN HALF OF UPPER MICHIGAN. TEMPERATURES WILL QUICKLY RISE TO ABOVE 38...WITH ONLY RAIN SHOWERS EXPECTED AFTER 1530Z. KMQT 88D RADAR REMAINS DOWN...AS TECHNICIANS AWAIT A PART THAT WILL BE ARRIVING THIS AFTERNOON. AT THIS TIME...THE RADAR IS EXPECTED TO BE BACK UP LATER TODAY. && .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST IS THE HIGH TEMPERATURE TODAY AND CHANCE OF FROST TONIGHT. WATER VAPOR IMAGERY AND RUC SHOWING A CLOSED LOW OVER EAST CENTRAL ONTARIO EMBEDDED IN A LONGWAVE TROUGH OVER CENTRAL CANADA. A LARGE RIDGE IS OVER THE CANADIAN PRAIRIES. WEAK SHORTWAVE IS SLIDING DOWN THE LEE OF THE RIDGE AND THROUGH THE FORECAST AREA. SURFACE ANALYSIS DEPICTS A COLD FRONT STRETCHING FROM A LOW OVER OHIO THROUGH THE CENTRAL PLAINS TO A LOW OVER ALBERTA. A RIDGE IS BUILDING OVER THE NORTHERN PLAINS. THE MID LEVEL RIDGE WILL MOVE INTO WESTERN MANITOBA TODAY PUSHING AGAINST THE LOW WHICH WILL REMAIN STATIONARY OVER EAST CENTRAL ONTARIO. A WEAK SHORTWAVE WILL SHIFT INTO WESTERN LAKE SUPERIOR. MEANWHILE...THE SURFACE RIDGE WILL SHIFT INTO THE MISSISSIPPI RIVER VALLEY. THE LOW OVER ALBERTA WILL SLIDE SOUTHEAST INTO SOUTHERN SASKATCHEWAN. FORECAST SOUNDINGS SUGGEST CUMULUS CLOUDS WILL DEVELOP OVER THE AREA...MAINLY OVER THE EASTERN U.P. BY NOON TODAY. A STRONG INVERSION AROUND 825MB WILL LIMIT DEVELOPMENT. IF ANY PRECIPITATION FALLS FROM THE CU...IT WILL DISSIPATE IN THE LOW LEVEL DRY AIR AS THE SOUNDINGS SHOWING A STRONG INVERTED V PATTERN EXCEPT OF THE EAST END OF THE CWA. THUS CLOUD COVER SHOULD LIMIT HEATING. TRAJECTORY FORECAST IS PULLING THE AIR MASS OVER CENTRAL ONTARIO INTO THE FORECAST AREA TODAY. THUS LOOKING FOR COOLER CONDITIONS TODAY. MOS DOES FAIRLY WELL UNDER THESE CONDITIONS SO WILL FOLLOW GUIDANCE. THE INVERTED V WOULD ALSO SUPPORT BREEZY CONDITIONS AGAIN TODAY. THE MID LEVEL LOW OVER ONTARIO WILL SHIFT INTO QUEBEC TONIGHT WHILE THE RIDGE OVER THE MISSISSIPPI RIVER VALLEY WILL START TO SHIFT INTO THE WESTERN U.P. DRY AIR WILL ALSO SHIFT INTO THE FORECAST AREA. THE LOW OVER SASKATCHEWAN WILL SHIFT INTO THE NORTHERN PLAINS WHILE EXPANDING INTO THE THE CENTRAL PLAINS. DRY AIR WILL REMAIN OVER THE AREA TONIGHT. THUS LOOKING FOR CLEARING. WINDS WILL ALSO DROP OFF. WITH THE LACK OF SURFACE HEATING TODAY DUE TO CLOUD COVER...LIGHTER WINDS UNDER THE RIDGE...AND CLEAR SKIES...CONDITIONS ARE FAVORABLE FOR SIGNIFICANT RADIATIONAL COOLING. THUS TEMPERATURE WILL DROP TO AROUND 29F OVER THE WEST AND LOW 30S EAST. A FROST ADVISORY IS IN ORDER. THE MID LEVEL RIDGE OVER MANITOBA WILL BREAKDOWN ON MONDAY WHILE THE WEST END OF THE RIDGE REMAINS OVER THE PACIFIC NORTHWEST. THE LOW OVER THE LOWER GREAT LAKES WILL SHIFT INTO QUEBEC. A SECONDARY LOW WILL DEVELOP AS A COUPLET WITH THE FIRST LOW AND WILL REACH JAMES BAY ON MONDAY. A WEAK SHORTWAVE WILL SLIDE DOWN THE LEE OF THE RIDGE AND THROUGH THE FORECAST AREA. ANOTHER WEAK SHORTWAVE WILL REACH NORTHERN MINNESOTA. SHOWERS AND A FEW THUNDERSTORMS WILL REACH JUST TO THE WEST OF THE FORECAST AREA. THE SHORTWAVE OVER MINNESOTA WILL SLIDE INTO THE WEST END OF THE FORECAST AREA MONDAY NIGHT. MODELS SHOWING MOST OF THE DEEP MOISTURE WILL SLIDE DOWN THE RIDGE AND MOVE ACROSS WISCONSIN INTO THE LOWER MICHIGAN. IN ASSOCIATION WITH THE SHORTWAVE A WEAK SURFACE LOW CENTER WILL ALSO SLIDE DOWN THE LEE OF THE RIDGE AND MOVE THROUGH WISCONSIN. THIS WILL BRING A CHANCE OF SHOWERS TO THE WEST END OF THE FORECAST AREA. A MID LEVEL RIDGE WILL BUILD OVER THE NORTHERN ROCKIES AND THE NORTHERN HIGH PLAINS...WHILE A SURFACE RIDGE BUILDS OVER CENTRAL CANADA AND PUSH INTO NORTHERN PLAINS. THE NORTHERN COUPLET THAT WAS OVER JAMES BAY WILL ROTATE INTO EAST CENTRAL ONTARIO ON TUESDAY. WEAK SHORTWAVES ROTATING AROUND THIS LOW WILL SWEEP THROUGH THE FORECAST AREA. DEEP MOISTURE ACCOMPANYING THE SHORTWAVES WILL REMAIN NORTH AND EAST OF THE FORECAST AREA. THUS PLAN TO KEEP THE HIGHER POPS OVER THE WESTERN AND SOUTHERN COUNTIES ONLY IN THE MORNING. AS DRY AIR MOVES BY LATE MORNING WILL LOW POPS FOR THE AFTERNOON. THE MID LEVEL LOW WILL SHIFT TO JUST NORTH OF GEORGIAN BAY TUESDAY NIGHT WHILE DIRECTING A WEAK SHORTWAVE THROUGH THE FORECAST AREA. THE RIDGE WILL MOVE OUT OF THE NORTHERN PLAINS TO THE UPPER MISSISSIPPI RIVER VALLEY. THE MID LEVEL RIDGE WILL SHIFT OVER THE NORTHERN PLAINS WHILE ANOTHER LOW DIGS OVER THE NORTHERN ROCKIES AND SOUTHWEST CANADA. THE MID LEVEL LOW WILL SETTLE OVER SOUTHEAST LOWER MICHIGAN ON WEDNESDAY. THE SURFACE RIDGE WILL SETTLE OVER THE FORECAST AREA. IN SPITE OF THE SHORTWAVES PASSING THROUGH THE AREA CONDITIONS WILL REMAIN DRY WITH SURFACE RIDGE REMAINING OVER THE AREA. THE SOUNDINGS CONTINUE TO SHOW DRY CONDITIONS OVER THE AREA. THE RIDGE WILL REMAIN OVER THE AREA THROUGH FRIDAY. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... EXPECT BROKEN MVFR DECK TO LIFT OR SCT OUT BY LATE MORNING AT BOTH TAF SITES. DIURNAL MIXING WILL ALLOW FOR NORTH-NORTHWEST WIND GUSTS AROUND 25 KTS AT BOTH PLACES. EXPECT KSAW WINDS TO BE SLIGHTLY STRONGER WITH TIGHTER GRADIENT THERE. WINDS WILL DECREASE BLO 10 KT BY SUNDAY EVENING WITH LOSS OF DIURNAL COMPONENT. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... CAA IN THE WAKE OF A FRONT WHICH MOVED THROUGH LAST NIGHT WILL CAUSE DECREASED STABILITY TODAY AS NORTHWEST WINDS WILL REACH 30 KT OVER THE CENTRAL AND EASTERN PORTIONS OF THE LAKE. A FEW GALE FORCE GUSTS ARE EVEN POSSIBLE FOR EASTERN PORTIONS. HIGH PRES WILL BUILD INTO THE AREA ON MON WITH DIMINISHING WINDS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/TONIGHT TO 8 AM EDT /7AM CDT/ MONDAY FOR MIZ001>007-009>015-084-085. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ UPDATE...KF DISCUSSION...DLG AVIATION...VOSS MARINE...VOSS mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 748 AM EDT SUN MAY 18 2008 UPDATED FOR 12Z AVIATION DISCUSSION .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST IS THE HIGH TEMPERATURE TODAY AND CHANCE OF FROST TONIGHT. WATER VAPOR IMAGERY AND RUC SHOWING A CLOSED LOW OVER EAST CENTRAL ONTARIO EMBEDDED IN A LONGWAVE TROUGH OVER CENTRAL CANADA. A LARGE RIDGE IS OVER THE CANADIAN PRAIRIES. WEAK SHORTWAVE IS SLIDING DOWN THE LEE OF THE RIDGE AND THROUGH THE FORECAST AREA. SURFACE ANALYSIS DEPICTS A COLD FRONT STRETCHING FROM A LOW OVER OHIO THROUGH THE CENTRAL PLAINS TO A LOW OVER ALBERTA. A RIDGE IS BUILDING OVER THE NORTHERN PLAINS. THE MID LEVEL RIDGE WILL MOVE INTO WESTERN MANITOBA TODAY PUSHING AGAINST THE LOW WHICH WILL REMAIN STATIONARY OVER EAST CENTRAL ONTARIO. A WEAK SHORTWAVE WILL SHIFT INTO WESTERN LAKE SUPERIOR. MEANWHILE...THE SURFACE RIDGE WILL SHIFT INTO THE MISSISSIPPI RIVER VALLEY. THE LOW OVER ALBERTA WILL SLIDE SOUTHEAST INTO SOUTHERN SASKATCHEWAN. FORECAST SOUNDINGS SUGGEST CUMULUS CLOUDS WILL DEVELOP OVER THE AREA...MAINLY OVER THE EASTERN U.P. BY NOON TODAY. A STRONG INVERSION AROUND 825MB WILL LIMIT DEVELOPMENT. IF ANY PRECIPITATION FALLS FROM THE CU...IT WILL DISSIPATE IN THE LOW LEVEL DRY AIR AS THE SOUNDINGS SHOWING A STRONG INVERTED V PATTERN EXCEPT OF THE EAST END OF THE CWA. THUS CLOUD COVER SHOULD LIMIT HEATING. TRAJECTORY FORECAST IS PULLING THE AIR MASS OVER CENTRAL ONTARIO INTO THE FORECAST AREA TODAY. THUS LOOKING FOR COOLER CONDITIONS TODAY. MOS DOES FAIRLY WELL UNDER THESE CONDITIONS SO WILL FOLLOW GUIDANCE. THE INVERTED V WOULD ALSO SUPPORT BREEZY CONDITIONS AGAIN TODAY. THE MID LEVEL LOW OVER ONTARIO WILL SHIFT INTO QUEBEC TONIGHT WHILE THE RIDGE OVER THE MISSISSIPPI RIVER VALLEY WILL START TO SHIFT INTO THE WESTERN U.P. DRY AIR WILL ALSO SHIFT INTO THE FORECAST AREA. THE LOW OVER SASKATCHEWAN WILL SHIFT INTO THE NORTHERN PLAINS WHILE EXPANDING INTO THE THE CENTRAL PLAINS. DRY AIR WILL REMAIN OVER THE AREA TONIGHT. THUS LOOKING FOR CLEARING. WINDS WILL ALSO DROP OFF. WITH THE LACK OF SURFACE HEATING TODAY DUE TO CLOUD COVER...LIGHTER WINDS UNDER THE RIDGE...AND CLEAR SKIES...CONDITIONS ARE FAVORABLE FOR SIGNIFICANT RADIATIONAL COOLING. THUS TEMPERATURE WILL DROP TO AROUND 29F OVER THE WEST AND LOW 30S EAST. A FROST ADVISORY IS IN ORDER. THE MID LEVEL RIDGE OVER MANITOBA WILL BREAKDOWN ON MONDAY WHILE THE WEST END OF THE RIDGE REMAINS OVER THE PACIFIC NORTHWEST. THE LOW OVER THE LOWER GREAT LAKES WILL SHIFT INTO QUEBEC. A SECONDARY LOW WILL DEVELOP AS A COUPLET WITH THE FIRST LOW AND WILL REACH JAMES BAY ON MONDAY. A WEAK SHORTWAVE WILL SLIDE DOWN THE LEE OF THE RIDGE AND THROUGH THE FORECAST AREA. ANOTHER WEAK SHORTWAVE WILL REACH NORTHERN MINNESOTA. SHOWERS AND A FEW THUNDERSTORMS WILL REACH JUST TO THE WEST OF THE FORECAST AREA. THE SHORTWAVE OVER MINNESOTA WILL SLIDE INTO THE WEST END OF THE FORECAST AREA MONDAY NIGHT. MODELS SHOWING MOST OF THE DEEP MOISTURE WILL SLIDE DOWN THE RIDGE AND MOVE ACROSS WISCONSIN INTO THE LOWER MICHIGAN. IN ASSOCIATION WITH THE SHORTWAVE A WEAK SURFACE LOW CENTER WILL ALSO SLIDE DOWN THE LEE OF THE RIDGE AND MOVE THROUGH WISCONSIN. THIS WILL BRING A CHANCE OF SHOWERS TO THE WEST END OF THE FORECAST AREA. A MID LEVEL RIDGE WILL BUILD OVER THE NORTHERN ROCKIES AND THE NORTHERN HIGH PLAINS...WHILE A SURFACE RIDGE BUILDS OVER CENTRAL CANADA AND PUSH INTO NORTHERN PLAINS. THE NORTHERN COUPLET THAT WAS OVER JAMES BAY WILL ROTATE INTO EAST CENTRAL ONTARIO ON TUESDAY. WEAK SHORTWAVES ROTATING AROUND THIS LOW WILL SWEEP THROUGH THE FORECAST AREA. DEEP MOISTURE ACCOMPANYING THE SHORTWAVES WILL REMAIN NORTH AND EAST OF THE FORECAST AREA. THUS PLAN TO KEEP THE HIGHER POPS OVER THE WESTERN AND SOUTHERN COUNTIES ONLY IN THE MORNING. AS DRY AIR MOVES BY LATE MORNING WILL LOW POPS FOR THE AFTERNOON. THE MID LEVEL LOW WILL SHIFT TO JUST NORTH OF GEORGIAN BAY TUESDAY NIGHT WHILE DIRECTING A WEAK SHORTWAVE THROUGH THE FORECAST AREA. THE RIDGE WILL MOVE OUT OF THE NORTHERN PLAINS TO THE UPPER MISSISSIPPI RIVER VALLEY. THE MID LEVEL RIDGE WILL SHIFT OVER THE NORTHERN PLAINS WHILE ANOTHER LOW DIGS OVER THE NORTHERN ROCKIES AND SOUTHWEST CANADA. THE MID LEVEL LOW WILL SETTLE OVER SOUTHEAST LOWER MICHIGAN ON WEDNESDAY. THE SURFACE RIDGE WILL SETTLE OVER THE FORECAST AREA. IN SPITE OF THE SHORTWAVES PASSING THROUGH THE AREA CONDITIONS WILL REMAIN DRY WITH SURFACE RIDGE REMAINING OVER THE AREA. THE SOUNDINGS CONTINUE TO SHOW DRY CONDITIONS OVER THE AREA. THE RIDGE WILL REMAIN OVER THE AREA THROUGH FRIDAY. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... EXPECT BROKEN MVFR DECK TO LIFT OR SCT OUT BY LATE MORNING AT BOTH TAF SITES. DIURNAL MIXING WILL ALLOW FOR NORTH-NORTHWEST WIND GUSTS AROUND 25 KTS AT BOTH PLACES. EXPECT KSAW WINDS TO BE SLIGHTLY STRONGER WITH TIGHTER GRADIENT THERE. WINDS WILL DECREASE BLO 10 KT BY SUNDAY EVENING WITH LOSS OF DIURNAL COMPONENT. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... CAA IN THE WAKE OF A FRONT WHICH MOVED THROUGH LAST NIGHT WILL CAUSE DECREASED STABILITY TODAY AS NORTHWEST WINDS WILL REACH 30 KT OVER THE CENTRAL AND EASTERN PORTIONS OF THE LAKE. A FEW GALE FORCE GUSTS ARE EVEN POSSIBLE FOR EASTERN PORTIONS. HIGH PRES WILL BUILD INTO THE AREA ON MON WITH DIMINISHING WINDS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/TONIGHT TO 8 AM EDT /7AM CDT/ MONDAY FOR MIZ001>007-009>015-084-085. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ DISCUSSION...DLG AVIATION...VOSS MARINE...VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 458 AM EDT SUN MAY 18 2008 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST IS THE HIGH TEMPERATURE TODAY AND CHANCE OF FROST TONIGHT. WATER VAPOR IMAGERY AND RUC SHOWING A CLOSED LOW OVER EAST CENTRAL ONTARIO EMBEDDED IN A LONGWAVE TROUGH OVER CENTRAL CANADA. A LARGE RIDGE IS OVER THE CANADIAN PRAIRIES. WEAK SHORTWAVE IS SLIDING DOWN THE LEE OF THE RIDGE AND THROUGH THE FORECAST AREA. SURFACE ANALYSIS DEPICTS A COLD FRONT STRETCHING FROM A LOW OVER OHIO THROUGH THE CENTRAL PLAINS TO A LOW OVER ALBERTA. A RIDGE IS BUILDING OVER THE NORTHERN PLAINS. THE MID LEVEL RIDGE WILL MOVE INTO WESTERN MANITOBA TODAY PUSHING AGAINST THE LOW WHICH WILL REMAIN STATIONARY OVER EAST CENTRAL ONTARIO. A WEAK SHORTWAVE WILL SHIFT INTO WESTERN LAKE SUPERIOR. MEANWHILE...THE SURFACE RIDGE WILL SHIFT INTO THE MISSISSIPPI RIVER VALLEY. THE LOW OVER ALBERTA WILL SLIDE SOUTHEAST INTO SOUTHERN SASKATCHEWAN. FORECAST SOUNDINGS SUGGEST CUMULUS CLOUDS WILL DEVELOP OVER THE AREA...MAINLY OVER THE EASTERN U.P. BY NOON TODAY. A STRONG INVERSION AROUND 825MB WILL LIMIT DEVELOPMENT. IF ANY PRECIPITATION FALLS FROM THE CU...IT WILL DISSIPATE IN THE LOW LEVEL DRY AIR AS THE SOUNDINGS SHOWING A STRONG INVERTED V PATTERN EXCEPT OF THE EAST END OF THE CWA. THUS CLOUD COVER SHOULD LIMIT HEATING. TRAJECTORY FORECAST IS PULLING THE AIR MASS OVER CENTRAL ONTARIO INTO THE FORECAST AREA TODAY. THUS LOOKING FOR COOLER CONDITIONS TODAY. MOS DOES FAIRLY WELL UNDER THESE CONDITIONS SO WILL FOLLOW GUIDANCE. THE INVERTED V WOULD ALSO SUPPORT BREEZY CONDITIONS AGAIN TODAY. THE MID LEVEL LOW OVER ONTARIO WILL SHIFT INTO QUEBEC TONIGHT WHILE THE RIDGE OVER THE MISSISSIPPI RIVER VALLEY WILL START TO SHIFT INTO THE WESTERN U.P. DRY AIR WILL ALSO SHIFT INTO THE FORECAST AREA. THE LOW OVER SASKATCHEWAN WILL SHIFT INTO THE NORTHERN PLAINS WHILE EXPANDING INTO THE THE CENTRAL PLAINS. DRY AIR WILL REMAIN OVER THE AREA TONIGHT. THUS LOOKING FOR CLEARING. WINDS WILL ALSO DROP OFF. WITH THE LACK OF SURFACE HEATING TODAY DUE TO CLOUD COVER...LIGHTER WINDS UNDER THE RIDGE...AND CLEAR SKIES...CONDITIONS ARE FAVORABLE FOR SIGNIFICANT RADIATIONAL COOLING. THUS TEMPERATURE WILL DROP TO AROUND 29F OVER THE WEST AND LOW 30S EAST. A FROST ADVISORY IS IN ORDER. THE MID LEVEL RIDGE OVER MANITOBA WILL BREAKDOWN ON MONDAY WHILE THE WEST END OF THE RIDGE REMAINS OVER THE PACIFIC NORTHWEST. THE LOW OVER THE LOWER GREAT LAKES WILL SHIFT INTO QUEBEC. A SECONDARY LOW WILL DEVELOP AS A COUPLET WITH THE FIRST LOW AND WILL REACH JAMES BAY ON MONDAY. A WEAK SHORTWAVE WILL SLIDE DOWN THE LEE OF THE RIDGE AND THROUGH THE FORECAST AREA. ANOTHER WEAK SHORTWAVE WILL REACH NORTHERN MINNESOTA. SHOWERS AND A FEW THUNDERSTORMS WILL REACH JUST TO THE WEST OF THE FORECAST AREA. THE SHORTWAVE OVER MINNESOTA WILL SLIDE INTO THE WEST END OF THE FORECAST AREA MONDAY NIGHT. MODELS SHOWING MOST OF THE DEEP MOISTURE WILL SLIDE DOWN THE RIDGE AND MOVE ACROSS WISCONSIN INTO THE LOWER MICHIGAN. IN ASSOCIATION WITH THE SHORTWAVE A WEAK SURFACE LOW CENTER WILL ALSO SLIDE DOWN THE LEE OF THE RIDGE AND MOVE THROUGH WISCONSIN. THIS WILL BRING A CHANCE OF SHOWERS TO THE WEST END OF THE FORECAST AREA. A MID LEVEL RIDGE WILL BUILD OVER THE NORTHERN ROCKIES AND THE NORTHERN HIGH PLAINS...WHILE A SURFACE RIDGE BUILDS OVER CENTRAL CANADA AND PUSH INTO NORTHERN PLAINS. THE NORTHERN COUPLET THAT WAS OVER JAMES BAY WILL ROTATE INTO EAST CENTRAL ONTARIO ON TUESDAY. WEAK SHORTWAVES ROTATING AROUND THIS LOW WILL SWEEP THROUGH THE FORECAST AREA. DEEP MOISTURE ACCOMPANYING THE SHORTWAVES WILL REMAIN NORTH AND EAST OF THE FORECAST AREA. THUS PLAN TO KEEP THE HIGHER POPS OVER THE WESTERN AND SOUTHERN COUNTIES ONLY IN THE MORNING. AS DRY AIR MOVES BY LATE MORNING WILL LOW POPS FOR THE AFTERNOON. THE MID LEVEL LOW WILL SHIFT TO JUST NORTH OF GEORGIAN BAY TUESDAY NIGHT WHILE DIRECTING A WEAK SHORTWAVE THROUGH THE FORECAST AREA. THE RIDGE WILL MOVE OUT OF THE NORTHERN PLAINS TO THE UPPER MISSISSIPPI RIVER VALLEY. THE MID LEVEL RIDGE WILL SHIFT OVER THE NORTHERN PLAINS WHILE ANOTHER LOW DIGS OVER THE NORTHERN ROCKIES AND SOUTHWEST CANADA. THE MID LEVEL LOW WILL SETTLE OVER SOUTHEAST LOWER MICHIGAN ON WEDNESDAY. THE SURFACE RIDGE WILL SETTLE OVER THE FORECAST AREA. IN SPITE OF THE SHORTWAVES PASSING THROUGH THE AREA CONDITIONS WILL REMAIN DRY WITH SURFACE RIDGE REMAINING OVER THE AREA. THE SOUNDINGS CONTINUE TO SHOW DRY CONDITIONS OVER THE AREA. THE RIDGE WILL REMAIN OVER THE AREA THROUGH FRIDAY. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... VFR CONDITIONS WILL CONTINUE THROUGH THE PERIOD AT BOTH PLACES. WIND SHEAR WILL BE AN ISSUE AT KSAW OVERNIGHT WITH STRONG NORTH WINDS OFF THE SURFACE. BOTH PLACES WILL MIX DOWN ON SUNDAY WITH SOME SUNSHINE AS CONDITIONS BECOME GUSTY IN THE MORNING. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... CAA IN THE WAKE OF A FRONT WHICH MOVED THROUGH LAST NIGHT WILL CAUSE DECREASED STABILITY TODAY AS NORTHWEST WINDS WILL REACH 30 KT OVER THE CENTRAL AND EASTERN PORTIONS OF THE LAKE. A FEW GALE FORCE GUSTS ARE EVEN POSSIBLE FOR EASTERN PORTIONS. HIGH PRES WILL BUILD INTO THE AREA ON MON WITH DIMINISHING WINDS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/TONIGHT TO 8 AM EDT /7AM CDT/ MONDAY FOR MIZ001>007-009>015-084-085. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ DISCUSSION...DLG AVIATION...GM MARINE...VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 127 AM EDT SUN MAY 18 2008 UPDATED FOR 06Z AVIATION DISCUSSION .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN ONTARIO BETWEEN LAKE SUPERIOR AND JAMES BAY LEAVING FAST CYCLONIC WNW FLOW THROUGH UPPER MI. A SHORTWAVE TROUGH THAT BROUGHT SHRA/TSRA WITH NMRS SMALL HAIL REPORTS HAD EXITED THE CWA TO NEAR THE STRAITS. ANOTHER SHORTWAVE OVER NW ONTARIO (JUST NW OF CYQT) WAS PIVOTING TOWARD THE CWA. AT THE SFC...LOW PRES WAS LOCATED S OF JAMES BAY WITH A COLD FRONT EXTENDING TO THE WEST TO NEAR KINL. EVEN WITH DRY LOW LEVELS...SFC DEWPOINTS INTO THE MID 30S OR LOWER...SUFFICIENT SFC HEATING WITH COLD MID LEVELS WITH STEEP LAPSE RATES NEAR 8 C/KM LED TO MLCAPE VALUES TO 300-500 J/KG. THE SHORTWAVE AND SFC TROUGH HAS SUPPORTED SCT/NMRS SHRA/TSRA OVER NE MN INTO WRN LAKE SUPERIOR. VERY GUSTY WINDS AOA 50 MPH HAVE BEEN OBSERVED WITH EVEN THE NON TSTM SHOWERS OVER NE MN AND AT ROAM ON ISLE ROYALE AS DEEP (INVERTED V) WELL MIXED LAYER WITH STRONG DOWNDRAFT POTENTIAL HAS ALSO PARTIALLY TAPPED 50 KT 5K FT WINDS...PER KDLH VAD WIND PRFL. .SHORT TERM...(TONIGHT AND SUNDAY) EXPECT ANOTHER PERIOD OF SCT SHRA/TSRA INTO UPPER MI AS THE SHORTWAVE AND COLD FRONT MOVES THROUGH. A BRIEF PERIOD OF STRONG WINDS WILL ALSO LIKELY ACCOMPANY THE FRONT ESPECIALLY WHERE STRONGER SHRA OR TSRA DEVELOP. AS THE TROUGH MOVES THROUGH AND HEATING SUBSIDES THE SHOWERS SHOULD DIMINISH. ISOLD LIGHT SHOWERS MAY STILL BE POSSIBLE OVERNIGHT WITH ANY WEAK TRAILING SHORTWAVES. MODELS SUGGEST THE COLD POOL AND DEEPER MOISTURE WILL SHIFT INTO THE FAR ERN CWA LEAVING DRY BUT COOL CONDITIONS OVER THE REST OF UPPER MI. && .LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)... FROST STILL LOOKS TO BE A CONCERNED SUNDAY NIGHT INTO MONDAY MORNING OVER THE WEST HALF OF UPPER MICHIGAN AND CLOUD EXIT AND COOLER AIR TAKES HOLD. ONE OF THE LAST OF THE SIGNIFICANT SHORTWAVES INFLUENCING WAVES WILL EXIT THE CWA AT THE START OF THE PERIOD. THE 17/00Z CANADIAN RUN IS TRYING TO ALLOW YET ANOTHER SHORTWAVE DIVE ACROSS UPPER MICHIGAN TUESDAY AFTERNOON. THIS IS LIKELY THE SAME WAVE THAT IS INDICATED BY THE NAM AND GFS MONDAY NIGHT OVER THE SAME AREA. WILL STAY CLOSE TO NAM AND GFS...WITH POPS MONDAY NIGHT THROUGH THE DAY TUESDAY. RIDGE IN THE WEST...AND TROUGH IN THE EAST. THIS PATTERN WILL BEGIN TO CHANGE...ESPECIALLY TUESDAY AS THE LARGE RIDGE IN THE WEST PROGRESSES EASTWARD ACROSS THE ROCKY MOUNTAIN FRONT. AT THIS TIME...WEDNESDAY LOOKS TO BE THE BEST DAY THIS WEEK WITH LINGERING CLOUDS EAST HEADING OUT. HOWEVER...WITH WINDS STILL FROM A NORTHERLY DIRECTION WE WILL LIKELY STILL REMAIN JUST AROUND NORMAL FOR HIGH TEMPERATURES. LOWERED DEW POINTS QUITE A BIT FOR WEDNESDAY. THE CURRENT TREND OF THE MODELS IS TO THEN KEEP THIS RIDGE OVER THE CWA THROUGH SATURDAY...WITH IF NOT DRY WEATHER...DRIER WEATHER THAN WHAT HAS BEEN EXPERIENCED AS OF LATE. THIS IS A SLOWER SOLUTION THAN 24 HOURS AGO...WHEN THE GFS WAS INDICATING A QUICKER BREAKDOWN OF THIS RIDGE. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... VFR CONDITIONS WILL CONTINUE THROUGH THE PERIOD AT BOTH PLACES. WIND SHEAR WILL BE AN ISSUE AT KSAW OVERNIGHT WITH STRONG NORTH WINDS OFF THE SURFACE. BOTH PLACES WILL MIX DOWN ON SUNDAY WITH SOME SUNSHINE AS CONDITIONS BECOME GUSTY IN THE MORNING. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... A TROUGH OR SECONDARY COLD FRONT WILL MOVE THROUGH LAKE SUPERIOR TONIGHT WITH VEERING WINDS AND INCREASING CAA. DECREASING STABILITY AND TIGHTENING GRADIENT BEHIND THE TROUGH WILL RESULT IN INCREASING NW TO N WINDS TO 30 KNOTS THROUGH SUNDAY. HIGH PRES WILL BUILD INTO THE AREA SUN NIGHT INTO MON WITH DIMINISHING WINDS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SHORT TERM...JLB LONG TERM...KF AVIATION...GM MARINE...JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 925 PM CDT MON MAY 19 2008 .UPDATE...MAIN FOCUS FOR TONIGHT IS FROST POTENTIAL. BATCHES OF CLOUDS CONTINUED TO MOVE THROUGH THE AREA DURING THE EVENING. ONE LARGE SCALE BATCH OF CLOUDS WAS MOVING ACROSS KOOCHICHING AND NORTHERN SAINT LOUIS COUNTIES AS OF 9 PM. THIS AREA OF CLOUDS WILL CONTINUE TO PRESS TO THE SOUTH OVERNIGHT. TEMPS HAVE DROPPED FAIRLY QUICKLY IN AREAS THAT HAVE TEMPORARILY CLEARED OUT...SUCH AS NEAR BRAINERD AND AITKIN. HAVE UPDATED TO ADD PATCHY FROST TO ALL ZONES. MAY NEED TO UPDATE AGAIN TO ADD FROST ADVISORY. THE MAIN CAVEAT FOR WIDESPREAD FROST IS THE TIGHTENING GRADIENT OVERNIGHT. THIS COULD KEEP SOME AREAS FROM RECEIVING FROST...WHILE AREAS THAT SEE WINDS DECOUPLE MAY SEE THE FROST. OTHER THAN THAT...WILL WORD ZONES WITH DECREASING CLOUDS OVERALL TONIGHT. && .PREV DISCUSSION... /ISSUED 326 PM CDT MON MAY 19 2008/ DISCUSSION... CURRENT WV IMAGERY SHOWING POTENT SHORTWAVE DROPPING SOUTHEASTWARD THROUGH MN. RATHER ROBUST H85 - H70 FGEN FORCING AND UVV BEING DEPICTED IN RUC CROSS SECTIONS ACROSS OUR SW ZONES. MOD RAIN HAS FALLEN IN A LINE FROM LONGVILLE TO AITKIN TO WEBSTER...WITH SOME SPRINKLES AS FAR NE AS CLOQUET EARLIER THIS AFTERNOON. DRY LOLVL AIR FROM THE TWIN PORTS AND POINTS NW WITH TIGHT NW TO SE GRADIENT IN THE SHOWERS WILL PREVENT THE ACTIVITY FROM MOVING ANY FARTHER NORTH AND WEST THROUGH THIS AFTERNOON. SHORT TERM... SHORTWAVE TROUGH EXITS THE AREA BY 00Z...TAKING WITH IT ANY REMAINING SHOWERS. ANOTHER SHOT OF COLD AIR PINWHEELS SOUTH AROUND MASSIVE VORTEX CENTERED OVER JAMES BAY...KEEPING TEMPS COLDER THAN NORMAL THROUGH THE SHORT TERM. MAY SEE SOME PATCHY FROST TONIGHT...THOUGH WINDS LOOK TO STAY STRONG ENOUGH TO PREVENT WIDESPREAD DEVELOPMENT. IN ADDITION...TD DEPRESSIONS LOOK TO BE ON THE ORDER OF 5+ DEGREES OVERNIGHT. EVENING SHIFT WILL HAVE TO MONITOR THIS. WINDS WILL BE GUSTY OUT OF THE NORTHWEST ON TUESDAY WITH HIGH PRESSURE OVER THE PLAINS AND LOW PRESSURE OVER JAMES BAY. A BETTER CHANCE FOR FROST EXISTS OVERNIGHT TUES...AND WED MORNING AS WINDS LOOK TO BECOME LIGHT. LONG TERM... MODELS COMING INTO BETTER AGREEMENT ON LARGE SCALE PATTERN CHANGE IN STORE FOR THE END OF THE WEEK...AS OMEGA BLOCK DEVELOPS WITH HIGHLY AMPLIFIED PATTERN. H50 RIDGE BUILDS INTO THE UPPER MIDWEST PROVIDING MAINLY CLEAR SKIES AND WARMING TEMPS...WITH MOST AREAS INTO THE 70S BY SATURDAY. LARGE TEMP GRADIENT MAY DEVELOP IN AREAS NEAR LAKE SUPERIOR HOWEVER...KEEPING TEMPS SIGNIFICANTLY COOLER HERE. NEXT CHANCE OF PRECIP ARRIVES NOT UNTIL THE SECOND HALF OF THE WEEKEND IN THE FORM OF SHOWERS AND THUNDERSTORMS. AVIATION... A WEAK LOW PRESSURE SYSTEM DROPPING SOUTHEAST THROUGH WESTERN MINNESOTA PUSH OFF TO THE SOUTH AND EAST TONIGHT. RAIN SHOWERS WILL CONTINUE THROUGH ABOUT 22-23 UTC ALONG A LINE FROM BEMIDJI AND PARK RAPIDS IN THE NORTHEAST TO NEAR JUST SOUTH AND WEST OF HAYWARD IN THE SOUTHEAST. CEILINGS AND VISIBILITIES SHOULD REMAIN VFR AT ALL SITES THROUGH THE TAF PERIOD...ALTHOUGH SOME TEMPO MVFR CEILINGS MAY BE POSSIBLE AT KBRD THROUGH 22 UTC. WINDS WILL BECOME NORTHWESTERLY ACROSS ALL LOCATIONS OVERNIGHT. WITH HIGH PRESSURE PUSHING IN FROM THE NORTH...SKIES WILL BEGIN TO CLEAR OVERNIGHT...AND MORE SO DURING THE DAY ON TUESDAY. WINDS WILL BE A BIT STRONGER ON TUESDAY WITH AN INCREASED PRESSURE GRADIENT BETWEEN THE DEPARTING LOW AND APPROACHING HIGH. && POINT TEMPS/POPS... DLH 37 59 35 57 / 10 10 10 10 INL 36 58 33 57 / 10 10 10 10 BRD 39 63 37 63 / 10 10 10 10 HYR 36 61 32 61 / 10 10 10 10 ASX 37 56 35 57 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ DAP mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 326 PM CDT MON MAY 19 2008 .DISCUSSION... CURRENT WV IMAGERY SHOWING POTENT SHORTWAVE DROPPING SOUTHEASTWARD THROUGH MN. RATHER ROBUST H85 - H70 FGEN FORCING AND UVV BEING DEPICTED IN RUC CROSS SECTIONS ACROSS OUR SW ZONES. MOD RAIN HAS FALLEN IN A LINE FROM LONGVILLE TO AITKIN TO WEBSTER...WITH SOME SPRINKLES AS FAR NE AS CLOQUET EARLIER THIS AFTERNOON. DRY LOLVL AIR FROM THE TWIN PORTS AND POINTS NW WITH TIGHT NW TO SE GRADIENT IN THE SHOWERS WILL PREVENT THE ACTIVITY FROM MOVING ANY FARTHER NORTH AND WEST THROUGH THIS AFTERNOON. .SHORT TERM... SHORTWAVE TROUGH EXITS THE AREA BY 00Z...TAKING WITH IT ANY REMAINING SHOWERS. ANOTHER SHOT OF COLD AIR PINWHEELS SOUTH AROUND MASSIVE VORTEX CENTERED OVER JAMES BAY...KEEPING TEMPS COLDER THAN NORMAL THROUGH THE SHORT TERM. MAY SEE SOME PATCHY FROST TONIGHT...THOUGH WINDS LOOK TO STAY STRONG ENOUGH TO PREVENT WIDESPREAD DEVELOPMENT. IN ADDITION...TD DEPRESSIONS LOOK TO BE ON THE ORDER OF 5+ DEGREES OVERNIGHT. EVENING SHIFT WILL HAVE TO MONITOR THIS. WINDS WILL BE GUSTY OUT OF THE NORTHWEST ON TUESDAY WITH HIGH PRESSURE OVER THE PLAINS AND LOW PRESSURE OVER JAMES BAY. A BETTER CHANCE FOR FROST EXISTS OVERNIGHT TUES...AND WED MORNING AS WINDS LOOK TO BECOME LIGHT. .LONG TERM... MODELS COMING INTO BETTER AGREEMENT ON LARGE SCALE PATTERN CHANGE IN STORE FOR THE END OF THE WEEK...AS OMEGA BLOCK DEVELOPS WITH HIGHLY AMPLIFIED PATTERN. H50 RIDGE BUILDS INTO THE UPPER MIDWEST PROVIDING MAINLY CLEAR SKIES AND WARMING TEMPS...WITH MOST AREAS INTO THE 70S BY SATURDAY. LARGE TEMP GRADIENT MAY DEVELOP IN AREAS NEAR LAKE SUPERIOR HOWEVER...KEEPING TEMPS SIGNIFICANTLY COOLER HERE. NEXT CHANCE OF PRECIP ARRIVES NOT UNTIL THE SECOND HALF OF THE WEEKEND IN THE FORM OF SHOWERS AND THUNDERSTORMS. && .AVIATION... A WEAK LOW PRESSURE SYSTEM DROPPING SOUTHEAST THROUGH WESTERN MINNESOTA PUSH OFF TO THE SOUTH AND EAST TONIGHT. RAIN SHOWERS WILL CONTINUE THROUGH ABOUT 22-23 UTC ALONG A LINE FROM BEMIDJI AND PARK RAPIDS IN THE NORTHEAST TO NEAR JUST SOUTH AND WEST OF HAYWARD IN THE SOUTHEAST. CEILINGS AND VISIBILITIES SHOULD REMAIN VFR AT ALL SITES THROUGH THE TAF PERIOD...ALTHOUGH SOME TEMPO MVFR CEILINGS MAY BE POSSIBLE AT KBRD THROUGH 22 UTC. WINDS WILL BECOME NORTHWESTERLY ACROSS ALL LOCATIONS OVERNIGHT. WITH HIGH PRESSURE PUSHING IN FROM THE NORTH...SKIES WILL BEGIN TO CLEAR OVERNIGHT...AND MORE SO DURING THE DAY ON TUESDAY. WINDS WILL BE A BIT STRONGER ON TUESDAY WITH AN INCREASED PRESSURE GRADIENT BETWEEN THE DEPARTING LOW AND APPROACHING HIGH. && POINT TEMPS/POPS... DLH 37 59 35 57 / 10 10 10 10 INL 36 58 33 57 / 10 10 10 10 BRD 39 63 37 63 / 20 10 10 10 HYR 36 61 32 61 / 10 10 10 10 ASX 37 56 35 57 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ LONKA/DONOFRIO mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 930 AM CDT MON MAY 19 2008 .UPDATE... UPGRADED TO SCATTERED WORDING IN RAIN SHOWERS THIS MORNING ACROSS OUR SOUTHWESTERN ZONES...AS RADAR TRENDS AND OBS SHOWING SHOWERS BEGINNING JUST WEST OF THE BRD AND CASS LAKES AREAS. LATEST RUC SNDGS STILL SHOWING SIG DRY AIR IN LOWER LEVELS MOST OF THE CWA THIS AFTERNOON... SO SHOWERS SHOULD REMAIN CONFINED TO JUST THE SRN AND WRN ZONES. TEMPS STILL LOOK GOOD ATTM. && .PREV DISCUSSION... /ISSUED 626 AM CDT MON MAY 19 2008/ UPDATE...CANCEL FROST ADVISORY DISCUSSION... TEMPERATURES HAVE BOTTOMED OUT AND CLOUDS CONTINUE TO INCREASE. LARGE T/TD SPREADS HAVE LIMITED FROST. PREV DISCUSSION... /ISSUED 326 AM CDT MON MAY 19 2008/ DISCUSSION... CHILLY MORNING ACROSS CWA AS TEMPS HAVE DIPPED INTO UPPER 20S ACROSS INTERIOR NORTHWEST WISCONSIN AND PARTS OF RANGE/ARROWHEAD. RADIATIONAL COOLING HAS BEEN MAXIMIZED UNDER SFC HIGH WITH LIGHT WIND AND CLEAR SKIES. CLOUDS ARE ON THE INCREASE AS APPROACHING SHORTWAVE MAKES ITS TREK FROM CTRL SASK SOUTHEASTWARD. TODAY/TONIGHT...INSPECTION OF MDL GUIDANCE HAS IMPROVED CONFIDENCE THAT A NARROW AREA OF FORCING WILL OCCUR OVER MAINLY SWRN CWA TODAY. CURRENT AREA OF MID LVL FRONTOGENESIS...ALONG WITH THE UVV SUPPLIED BY THE SHORTWAVE... NOT GENERATING MUCH PRECIP AT THIS TIME AS IT MOVES ACROSS ERN ND DUE TO RELATIVELY DRY LOW LEVELS. RUC80 FCST OF THIS FRONTOGENESIS PUSHES IT ACROSS SWRN CWA MAINLY FROM CASS COUNTY SOUTHEAST TOWARDS PINE COUNTY TODAY. NO SIGNIFICANT LL BDRY TO ACT UPON TO DEEPEN CONVERGENCE ZONE. FCST UPPER JET CORE WITH LF UVV REGION IS POISED TO AFFECT MPX CWA MORE THAN DLH SO NOT ANTICIPATING A LOT OF PRECIP WITH THIS SYSTEM. SREF PROBABILITIES OF AMNTS GREATER THAN .25" ARE LESS THAN 10 PERCENT. LL DRY AIR SHOULD DO A GOOD JOB OF ELIMINATING/REDUCING CHANCES OF RAIN FARTHER EAST. SYSTEM WILL MOVE THROUGH FAIRLY QUICKLY SO EXPECT CLEARING TO PUSH ACROSS BY 12Z TUESDAY. TOMORROW...ALTHOUGH GENERAL AGREEMENT EXISTS THAT FORCING/PRECIP WILL REMAIN SOUTH AND EAST OF CWA...SOME DIFFERENCES ON HOW QUICKLY MID LVL TROF MOVES EAST. EC IS AN OUTLIER IN KEEPING A LARGE AREA OF CLOUD COVER ACROSS ERN CWA TUESDAY AFTERNOON. FOR NOW...HAVE USED MDL CONSENSUS ON KEEPING CLOUDS MAINLY EAST. GIVEN LARGE OMEGA BLOCK DEVELOPING...THIS MAY NEED UPDATING TO SIDE MORE WITH EC. EXTENDED...WEDNESDAY THROUGH SUNDAY....GUIDANCE IS CONTINUING MDT/STRONG AGREEMENT ON PATTERN FOR THE REST OF THE WEEK. GRADUAL MODERATION IN SFC TEMPS THROUGH WEEK AND LITTLE/NO OPPORTUNITY FOR PRECIP. CWA UNDERNEATH LARGE MID LVL HIGH AS OMEGA BLOCK STRENGTHENS. CONSIDERABLE TEMP DIFFERENCES MAY DEVELOP AS LAKE BREEZE KEEPS NEARSHORE COOLER THROUGH WEEK WHILE INLAND LOCATIONS WARM. 85H TEMPS THIS WEEKEND ARE WELL ABOVE AVERAGE SO MAY SEE SOME SERIOUS WARMING. AVIATION... HIGH PRESSURE WILL SHIFT EAST OVER WESTERN LAKE SUPERIOR TODAY AS A WEAK SHORTWAVE DROPS SOUTHEAST THROUGH THE EASTERN DAKOTAS AND WESTERN MINNESOTA...BRINGING AN INCREASE IN MAINLY MID AND HIGH LEVEL CLOUDS TO THE AREA. A FEW RAIN SHOWERS WILL ALSO BE POSSIBLE ACROSS THE WEST AND SOUTH THIS AFTERNOON AND EVENING AS THIS SYSTEM PASSES. CEILINGS AND VISIBILITIES SHOULD REMAIN VFR AT ALL SITES THROUGH THE TAF PERIOD...ALTHOUGH SOME TEMPO MVFR CEILINGS MAY BE POSSIBLE IN THE SOUTHWEST...INCLUDING KBRD...FROM ROUGHLY 20Z-01Z. SUSTAINED WINDS WILL REMAIN GENERALLY 10 KTS OR LESS THROUGH TONIGHT. && POINT TEMPS/POPS... DLH 57 38 59 37 / 10 10 10 10 INL 63 37 58 33 / 10 10 10 10 BRD 56 40 62 38 / 50 20 10 10 HYR 62 36 62 35 / 20 30 20 10 ASX 59 37 57 36 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ TL/KD mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 626 AM CDT MON MAY 19 2008 .UPDATE...CANCEL FROST ADVISORY && .DISCUSSION... TEMPERATURES HAVE BOTTOMED OUT AND CLOUDS CONTINUE TO INCREASE. LARGE T/TD SPREADS HAVE LIMITED FROST. && .PREV DISCUSSION... /ISSUED 326 AM CDT MON MAY 19 2008/ DISCUSSION... CHILLY MORNING ACROSS CWA AS TEMPS HAVE DIPPED INTO UPPER 20S ACROSS INTERIOR NORTHWEST WISCONSIN AND PARTS OF RANGE/ARROWHEAD. RADIATIONAL COOLING HAS BEEN MAXIMIZED UNDER SFC HIGH WITH LIGHT WIND AND CLEAR SKIES. CLOUDS ARE ON THE INCREASE AS APPROACHING SHORTWAVE MAKES ITS TREK FROM CTRL SASK SOUTHEASTWARD. TODAY/TONIGHT...INSPECTION OF MDL GUIDANCE HAS IMPROVED CONFIDENCE THAT A NARROW AREA OF FORCING WILL OCCUR OVER MAINLY SWRN CWA TODAY. CURRENT AREA OF MID LVL FRONTOGENESIS...ALONG WITH THE UVV SUPPLIED BY THE SHORTWAVE... NOT GENERATING MUCH PRECIP AT THIS TIME AS IT MOVES ACROSS ERN ND DUE TO RELATIVELY DRY LOW LEVELS. RUC80 FCST OF THIS FRONTOGENESIS PUSHES IT ACROSS SWRN CWA MAINLY FROM CASS COUNTY SOUTHEAST TOWARDS PINE COUNTY TODAY. NO SIGNIFICANT LL BDRY TO ACT UPON TO DEEPEN CONVERGENCE ZONE. FCST UPPER JET CORE WITH LF UVV REGION IS POISED TO AFFECT MPX CWA MORE THAN DLH SO NOT ANTICIPATING A LOT OF PRECIP WITH THIS SYSTEM. SREF PROBABILITIES OF AMNTS GREATER THAN .25" ARE LESS THAN 10 PERCENT. LL DRY AIR SHOULD DO A GOOD JOB OF ELIMINATING/REDUCING CHANCES OF RAIN FARTHER EAST. SYSTEM WILL MOVE THROUGH FAIRLY QUICKLY SO EXPECT CLEARING TO PUSH ACROSS BY 12Z TUESDAY. TOMORROW...ALTHOUGH GENERAL AGREEMENT EXISTS THAT FORCING/PRECIP WILL REMAIN SOUTH AND EAST OF CWA...SOME DIFFERENCES ON HOW QUICKLY MID LVL TROF MOVES EAST. EC IS AN OUTLIER IN KEEPING A LARGE AREA OF CLOUD COVER ACROSS ERN CWA TUESDAY AFTERNOON. FOR NOW...HAVE USED MDL CONSENSUS ON KEEPING CLOUDS MAINLY EAST. GIVEN LARGE OMEGA BLOCK DEVELOPING...THIS MAY NEED UPDATING TO SIDE MORE WITH EC. EXTENDED...WEDNESDAY THROUGH SUNDAY....GUIDANCE IS CONTINUING MDT/STRONG AGREEMENT ON PATTERN FOR THE REST OF THE WEEK. GRADUAL MODERATION IN SFC TEMPS THROUGH WEEK AND LITTLE/NO OPPORTUNITY FOR PRECIP. CWA UNDERNEATH LARGE MID LVL HIGH AS OMEGA BLOCK STRENGTHENS. CONSIDERABLE TEMP DIFFERENCES MAY DEVELOP AS LAKE BREEZE KEEPS NEARSHORE COOLER THROUGH WEEK WHILE INLAND LOCATIONS WARM. 85H TEMPS THIS WEEKEND ARE WELL ABOVE AVERAGE SO MAY SEE SOME SERIOUS WARMING. AVIATION... HIGH PRESSURE WILL SHIFT EAST OVER WESTERN LAKE SUPERIOR TODAY AS A WEAK SHORTWAVE DROPS SOUTHEAST THROUGH THE EASTERN DAKOTAS AND WESTERN MINNESOTA...BRINGING AN INCREASE IN MAINLY MID AND HIGH LEVEL CLOUDS TO THE AREA. A FEW RAIN SHOWERS WILL ALSO BE POSSIBLE ACROSS THE WEST AND SOUTH THIS AFTERNOON AND EVENING AS THIS SYSTEM PASSES. CEILINGS AND VISIBILITIES SHOULD REMAIN VFR AT ALL SITES THROUGH THE TAF PERIOD...ALTHOUGH SOME TEMPO MVFR CEILINGS MAY BE POSSIBLE IN THE SOUTHWEST...INCLUDING KBRD...FROM ROUGHLY 20Z-01Z. SUSTAINED WINDS WILL REMAIN GENERALLY 10 KTS OR LESS THROUGH TONIGHT. && POINT TEMPS/POPS... DLH 57 38 59 37 / 10 10 10 10 INL 63 37 58 33 / 20 10 10 10 BRD 56 40 62 38 / 50 20 10 10 HYR 62 36 62 35 / 20 30 20 10 ASX 59 37 57 36 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ CANNON/BETTWY mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 326 AM CDT MON MAY 19 2008 .DISCUSSION... CHILLY MORNING ACROSS CWA AS TEMPS HAVE DIPPED INTO UPPER 20S ACROSS INTERIOR NORTHWEST WISCONSIN AND PARTS OF RANGE/ARROWHEAD. RADIATIONAL COOLING HAS BEEN MAXIMIZED UNDER SFC HIGH WITH LIGHT WIND AND CLEAR SKIES. CLOUDS ARE ON THE INCREASE AS APPROACHING SHORTWAVE MAKES ITS TREK FROM CTRL SASK SOUTHEASTWARD. TODAY/TONIGHT...INSPECTION OF MDL GUIDANCE HAS IMPROVED CONFIDENCE THAT A NARROW AREA OF FORCING WILL OCCUR OVER MAINLY SWRN CWA TODAY. CURRENT AREA OF MID LVL FRONTOGENESIS...ALONG WITH THE UVV SUPPLIED BY THE SHORTWAVE... NOT GENERATING MUCH PRECIP AT THIS TIME AS IT MOVES ACROSS ERN ND DUE TO RELATIVELY DRY LOW LEVELS. RUC80 FCST OF THIS FRONTOGENESIS PUSHES IT ACROSS SWRN CWA MAINLY FROM CASS COUNTY SOUTHEAST TOWARDS PINE COUNTY TODAY. NO SIGNIFICANT LL BDRY TO ACT UPON TO DEEPEN CONVERGENCE ZONE. FCST UPPER JET CORE WITH LF UVV REGION IS POISED TO AFFECT MPX CWA MORE THAN DLH SO NOT ANTICIPATING A LOT OF PRECIP WITH THIS SYSTEM. SREF PROBABILITIES OF AMNTS GREATER THAN .25" ARE LESS THAN 10 PERCENT. LL DRY AIR SHOULD DO A GOOD JOB OF ELIMINATING/REDUCING CHANCES OF RAIN FARTHER EAST. SYSTEM WILL MOVE THROUGH FAIRLY QUICKLY SO EXPECT CLEARING TO PUSH ACROSS BY 12Z TUESDAY. TOMORROW...ALTHOUGH GENERAL AGREEMENT EXISTS THAT FORCING/PRECIP WILL REMAIN SOUTH AND EAST OF CWA...SOME DIFFERENCES ON HOW QUICKLY MID LVL TROF MOVES EAST. EC IS AN OUTLIER IN KEEPING A LARGE AREA OF CLOUD COVER ACROSS ERN CWA TUESDAY AFTERNOON. FOR NOW...HAVE USED MDL CONSENSUS ON KEEPING CLOUDS MAINLY EAST. GIVEN LARGE OMEGA BLOCK DEVELOPING...THIS MAY NEED UPDATING TO SIDE MORE WITH EC. EXTENDED...WEDNESDAY THROUGH SUNDAY....GUIDANCE IS CONTINUING MDT/STRONG AGREEMENT ON PATTERN FOR THE REST OF THE WEEK. GRADUAL MODERATION IN SFC TEMPS THROUGH WEEK AND LITTLE/NO OPPORTUNITY FOR PRECIP. CWA UNDERNEATH LARGE MID LVL HIGH AS OMEGA BLOCK STRENGTHENS. CONSIDERABLE TEMP DIFFERENCES MAY DEVELOP AS LAKE BREEZE KEEPS NEARSHORE COOLER THROUGH WEEK WHILE INLAND LOCATIONS WARM. 85H TEMPS THIS WEEKEND ARE WELL ABOVE AVERAGE SO MAY SEE SOME SERIOUS WARMING. && .AVIATION... HIGH PRESSURE WILL SHIFT EAST OVER WESTERN LAKE SUPERIOR TODAY AS A WEAK SHORTWAVE DROPS SOUTHEAST THROUGH THE EASTERN DAKOTAS AND WESTERN MINNESOTA...BRINGING AN INCREASE IN MAINLY MID AND HIGH LEVEL CLOUDS TO THE AREA. A FEW RAIN SHOWERS WILL ALSO BE POSSIBLE ACROSS THE WEST AND SOUTH THIS AFTERNOON AND EVENING AS THIS SYSTEM PASSES. CEILINGS AND VISIBILITIES SHOULD REMAIN VFR AT ALL SITES THROUGH THE TAF PERIOD...ALTHOUGH SOME TEMPO MVFR CEILINGS MAY BE POSSIBLE IN THE SOUTHWEST...INCLUDING KBRD...FROM ROUGHLY 20Z-01Z. SUSTAINED WINDS WILL REMAIN GENERALLY 10 KTS OR LESS THROUGH TONIGHT. && POINT TEMPS/POPS... DLH 57 38 59 37 / 10 10 10 10 INL 63 37 58 33 / 20 10 10 10 BRD 56 40 62 38 / 50 20 10 10 HYR 62 36 62 35 / 20 30 20 10 ASX 59 37 57 36 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR CARLTON/SOUTHERN ST. LOUIS-CENTRAL ST. LOUIS-KOOCHICHING-NORTHERN AITKIN- NORTHERN COOK/NORTHERN LAKE-NORTHERN ITASCA-NORTHERN ST. LOUIS-PINE-SOUTHERN AITKIN-SOUTHERN COOK/LAKESHORE-SOUTHERN ITASCA-SOUTHERN LAKE/LAKESHORE. WI...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR ASHLAND-BAYFIELD- BURNETT-DOUGLAS-IRON-PRICE-SAWYER-WASHBURN. LS...NONE. $$ CANNON/BETTWY mn AREA FORECAST DISCUSSION...UPDATED AVIATION NATIONAL WEATHER SERVICE ST LOUIS MO 1128 PM CDT MON MAY 19 2008 .UPDATE... /904 PM CDT MON MAY 19 2008/ UPDATED FORECAST TO GO WITH HIGHER POPS OVER THE NRN CWA THROUGH 07Z BASED ON AREA OF SHRA/ISOLD TSRA CURRENTLY MOVING SEWD ACROSS SERN IA. THIS AREA CORRESPONDS WELL WITH THE RUC/NAM 925-850MB MOISTURE CONVERGENCE/THETA-E DECPICTION WHICH FADES AFTER 06Z...SO HAVE KEPT SAME LOW CHC POP CONFINED TO THE ERN CWA LATE TONIGHT. ADJUSTED SKY GRIDS TO REFLECT CURRENT TRENDS. TEMPERATURES LOOK GOOD. BRITT && .DISCUSSION... /341 PM CDT MON MAY 19 2008/ MODELS CONTINUE TO ADVERTISE NWLY FLOW AT H500 THRU THURSDAY. ONLY A COUPLE OF DISTURBANCES OF NOTE TO TRACK IN THIS FLOW...WITH THE FIRST MOVING THRU TONIGHT ON THE HEELS OF THE SYSTEM THAT IS NOW MOVING THRU THE FA NOW. THE OTHER WILL BE A SHEARED VORTICITY MAX THAT WILL LINGER OVER THE NERN FA THRU TUESDAY. AT THE SURFACE...LO PRES OVER THE SRN FA ATTM WILL TRACK EWD...AND DRAG A CDFNT ACROSS THE SRN FA EARLY THIS EVENING. TROFINESS IN THE ERN FA AND FRONTAL BOUNDARY OVER THE SRN FA WILL LINGER THRU TUESDAY. SFC HI PRES RIDGE WILL THEN MOVE IN FOR TUESDAY NIGHT THRU WEDNESDAY NIGHT...WITH ELY FLOW DEVELOPING LATE WEDNESDAY NIGHT INTO THURSDAY AS SFC RIDGE SLOWLY PULLS AWAY. FOR EARLY THIS EVENING...MID 50S DEWPOINTS NOW HAVE PUSHED JUST AHEAD OF SFC LO PRES...AND WITH DECENT CONVERGENCE NOTED...MAY BE ABLE TO POP A TSRA OR TWO OVER THE SERN FA BEFORE THIS ACTIVITY EXITS. LATER THIS EVENING AND OVERNIGHT...ATTENTION THEN TURNS TO THE APPROACHING UPPER LEVEL SYSTEM FROM THE NW...BUT FIRST SYSTEM THAT IS EXITING THE SRN FA EARLY THIS EVENING WILL SCOUR THE LOWER AMS OF MOISTURE AND THIS SECOND SYSTEM IS FAIRLY MOISTURE STARVED. ONLY HAVE LOW POPS IN FOR PRIMARILY THE NERN FA...WHERE BEST LIFT WILL BE. FOR TUESDAY...NAM CONSISTENT IN KICKING PCPN OUT FOR THE CNTRL/ERN FA...BUT I AM SKEPTICAL ON THIS. MOISTURE IS RATHER LIMITED AND MAIN LIFT...WHAT LITTLE THERE IS...WILL ONCE AGAIN BE OVER THE SERN FA. STILL...NAM CONSISTENCY IS STILL BOTHERSOME. HAVE PLACED SLIGHT CHANCES IN FOR THE ERN/SERN FA. SHOULD THEN SEE A DRY PERIOD TUESDAY NIGHT AND WEDNESDAY BEFORE GRADIENT OF MOISTURE BEGINS TO EDGE BACK INTO CNTRL/SERN MO BY WEDNESDAY NIGHT AND THURSDAY. H850 MOISTURE CONVERGENCE AND WAA ALSO INCREASES IN THIS AREA AS FRONTAL ZONE DEEPENS...AND SO HAVE THEREFORE MAINTAINED CHANCE POPS. TEMPS WILL REMAIN AOB NORMAL THRU MID WEEK AS NLY AND ELY FLOW FROM FRONTS AND BUILDING SFC RIDGES KEEP THE HEAT AWAY. FOR THE EXTENDED PERIOD (THURSDAY NIGHT - MONDAY)...MODELS REMAIN IN GOOD AGREEMENT THAT A H500 HI-AMPLITUDE RIDGE WILL DOMINATE THE FIRST HALF OF THE HOLIDAY WEEKEND...WITH A GRADUAL BREAKDOWN IN AMPLITUDE TOWARD MEMORIAL DAY. THE GFS ADVERTISES THE GREATEST BREAKDOWN IN THIS RIDGE...BUT AS WE HAVE SEEN THE PAST FEW DAYS OF MODEL RUNS...THE ECMWF HAS LEAD IN SHOWING THE RIDGE HANGING TOUGH THE LONGEST...AND THE GFS HAS FOLLOWED THIS LEAD ABOUT A DAY BEHIND. AT THE SURFACE...A STRONG HI PRES WILL LINGER TO THE E OF THE FA FOR MUCH OF THIS PERIOD...PROVIDING AN ELY FLOW...AND COUPLED WITH A FRONTAL BOUNDARY WELL TO OUR SW...WILL KEEP THE HEAT LARGELY AT BAY DESPITE RATHER HIGH H500 HEIGHTS ABOVE US. MODELS ARE NOW SHOWING THE BEGINNINGS OF THE RELEASE OF THE HEAT ON MONDAY...PUSHING IT BACK YET ANOTHER DAY. PLAN ON KEEPING THIS PERIOD DRY WITH THE FRONTAL BOUNDARY WELL TO THE SW AND AIR TOO DRY AT THE LO LEVELS FOR ANY SFC-BASED CONVECTION...IT WILL ALL HAVE TO BE ELEVATED. ONLY REAL CHANCE APPEARS TO BE VERY EARLY IN THE PERIOD ON THURSDAY NIGHT AND POSSIBLY CARRYING INTO FRIDAY WHERE ELEVATED FRONTAL ZONE FORCING MAY KICK OFF SOME CONVECTION. LINGERED SLIGHT CHANCES THERE DURING THAT PERIOD. TEMPS WILL BE AOB NORMAL UNTIL MEMORIAL DAY WHERE THEY SHOULD EDGE ABOVE NORMAL. TES && .AVIATION... /1109 PM CDT MON MAY 19 2008/ FOR THE 06Z TAFS...SCT SHRA/TSRA WILL CONT TO MOVE SEWD THRU UIN TIL ABOUT 06Z OR 07Z TUE AHD OF A NW FLOW SHRTWV TROF CNTRD OVER SERN IA ATTM. THIS ACTIVITY WAS ALSO NEAR A SFC TROF EXTDG FM A SFC LOW OVR WRN KY NW THRU N CNTRL MO. MAINLY JUST SOME CIRRUS CLOUDS AT COU..STL AND SUS ATTM...BUT MID LVL CLOUDINESS FM IRK TO UIN WILL ADVCT SEWD INTO CNTRL MO LT TGT AS SHRTWV TROF MOVES SEWD THRU PTNS OF CNTRL AND SRN IL. MAY INCLUDE VCTS OR VCSH IN STL BTWN 07Z-10Z TUE DEPENDING ON THE LATEST RADAR TRENDS...ALTHOUGH IT APRS THAT MOST OF THE SHRA/TSRA WILL PASS JUST E OF STL LT TGT. LARGE AREA OF MID LVL CLOUDS OVER SRN MN AND NRN IA WILL LIKELY MOVE SEWD INTO UIN TOWARDS THE EARLY MRNG HRS. MDL RH FCST GUIDANCE AND MOS CLOUD CEILING HGT GUIDANCE FM ETA AND GFS DEPICT LOW LVL MOISTURE AND LOW LVL CLOUDINESS AT THE TAF SITES ON TUE. WILL INCLUDE SCT LOW LVL CLOUDS IN COU TUE...AND A BKN CEILING OF LOW LVL CLOUDS IN UIN...STL AND SUS ON TUE BUT WILL LEAVE IT IN THE VFR CATAGORY. SFC WNDS WILL BE NWLY ON TUE AHD OF A SFC RDG BLDG SEWD INTO MO. THE CLOUDS SHOULD CLR OUT TUE EVNG WITH WKNG W-NWLY SFC WNDS. GKS && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX mo AREA FORECAST DISCUSSION...UPDATED AVIATION NATIONAL WEATHER SERVICE ST LOUIS MO 1103 PM CDT SUN MAY 18 2008 .UPDATE... /925 PM CDT SUN MAY 18 2008/ GOING FORECAST CONTINUES TO LOOK GOOD WITH CHANCES OF SHRA INCREASING MAINLY AFTER 3 AM OVER THE NORTHERN PART OF THE CWA. RUC CONTINUES TO SHOW DECENT 925-850MB MOISTURE CONVERGENCE AND INCREASING THETA-E ADVECTION AS ASCENT INCREASES IN ADVANCES OF WEAK SHORTWAVE TROUGH. TEMPERATURE AND SKY TRENDS ALSO LOOK GOOD. BRITT && .DISCUSSION... /348 PM CDT SUN MAY 18 2008/ NWP MODELS ALL AGREE ON NWLY MID LEVEL FLOW BEING THE RULE THRU EARLY NEXT WEEK...BUT HAVE THEIR DISAGREEMENTS ON EXACTLY WHAT THIS MEANS FOR THE MID MS VALLEY WRT PCPN CHANCES. A SERIES OF DISTURBANCES WILL MOV SEWD THRU THE AREA OVER THE NEXT FEW DAYS AND WILL INTERACT WITH...FOR THE MOST PART...MOISTURE THAT IS AOA NORMAL FOR LATE MAY. THE FIRST SYSTEM WILL BE A SHORTWAVE WITH ATTENDANT LO PRES THAT WILL APPROACH THE AREA LATE TONIGHT. DECENT LIFT THRU THE COLUMN BY 12Z OVER THE NWRN FA WHICH SHOULD RESULT IN SCT SHRA BY DAYBREAK. THE BEST LIFT/PCPN CHCS WITH THE SYSTEM WILL THEN TRACK SEWD THRU THE NERN HALF OF THE FA...WHICH WILL BE TO THE LEFT OF THE EXPECTED SFC LO TRACK. HOWEVER...FORCING OVER CNTRL MO FROM H850 JET/WAA MAY TRIGGER SOME ELEVATED CONVECTION THERE...AND AS THIS FORCING MOVES INTO SERN MO BY AFTN...IT WILL OPEN THE WAY FOR MORE SFC-BASED CONVECTION. SHEAR WILL MAKE IT POSSIBLE FOR TSRA WITH STRONG GUSTY WINDS OVER THE ERN OZARKS AND SRN IL. THIS SYSTEM WILL THEN EXIT THE FAR SRN FA BY EARLY MONDAY EVENING. LOOK FOR A TIGHT TEMP GRADIENT MONDAY AFTERNOON...WHERE LO PRES TRACK SEPARATES CLOUDS/PCPN FROM PTSUNNY SKIES WITH MORE ISOLATED PCPN. THE NEXT SYSTEM...ADVERTISED AS A CLIPPER-TYPE SYSTEM THAT WAS EXPECTED TO MAINLY GO INTO THE GRTLKS REGION...IS NOW TRACKING A BIT MORE SE AND MAY TRIGGER ANOTHER ROUND OF SHRA/TSRA FOR THE NERN FA LATER MONDAY NIGHT. EDGED POPS UP A BIT THERE TO ACCOUNT FOR THIS. WEDNESDAY COULD BE RATHER COOL...ESP IN THE NERN HALF OF THE FA... WITH COOL START...WEAK SFC FLOW...AND INCRSG CLOUDINESS. EDGED DOWN FROM PREV FCST SEVERAL DEGS...BUT NOT QUITE AS COOL AS MOS SUGGESTS WHICH SEEMED TO BE TOO COOL. FOR THE EXTENDED PERIOD (WEDNESDAY NIGHT - SUNDAY)...MODELS IN GOOD AGREEMENT ON UPPER LEVEL MASS FIELDS...WITH HI AMPLITUDE RIDGE DOMINATING THE UPCOMING HOLIDAY WEEKEND. IT WILL BEGIN TO ESTABLISH ITSELF ON THURSDAY...AND WITH A PRE-EXISTING FRONTAL ZONE ALREADY IN PLACE...THIS WILL LEAD TO A CHANCE OF SHRA/TSRA OVER MUCH OF THE AREA. BUT ONCE RIDGE GETS MORE FIRMLY ESTABLISHED WITH ITS LIGHT WIND REGIME AND NEAR MERIDIONAL FLOW...SHOULD SEE DRY WEATHER PREVAIL. AT THE SURFACE...MODELS HAVE TRENDED TOWARD A STRONGER BACKDOOR HI PRES FOR THIS PERIOD...WHICH WILL TEND TO EXPAND THE FRONTAL ZONE PCPN A BIT FURTHER SWWD INTO CNTRL AND SERN MO FOR EARLY IN THE PERIOD...BUT ALSO KEEP TEMPS COOLER AND DEWPOINTS LOWER FOR A LONGER PERIOD OF TIME WITH ITS PERSISTENT ELY FLOW. COULD BE A REAL NICE WEEKEND ON TAP... BUT IT IS STILL FAR OUT THERE. MAIN MODEL DIFFS ARE A BREAKDOWN IN THE RIDGE OVER THE NRN CONUS BY SUNDAY WHICH MAY ALLOW SOME ENERGY TO BREAKOFF FROM DEEP TROF OVER THE W...BUT ECMWF HOLDS THIS FIRM AND KEEPS RAIN CHANCES WELL TO THE W. FOR NOW HAVE LEFT SUNDAY DRY...FOLLOWING PERSISTENCE. TES && .AVIATION... /1037 PM CDT SUN MAY 18 2008/ FOR THE 06Z TAFS...LGT SFC WNDS LT THIS EVNG WILL BCM SELY BY EARLY MRNG AS A SFC LOW MOVES SEWD FM NEBRASKA INTO NERN KS AND AS A WK SFC RDG MOVES E OF THE TAF SITES. MID LVL CLOUDINESS WL DVLP AND SPREAD SEWD THRU THE CWA LT TGT WITH THE APPROACH OF A WK NW FLOW SHRTWV TROF...AND AS LOW-MID LVL WAA INCRS OVER THE CWA ON THE NOSE OF A SWLY LLJ. THE SFC LOW IS FCST TO MOVE SEWD THRU THE AREA ON MON...TRACKING JUST S OF COU AND STL. SELY SFC WNDS AT UIN WL BACK ARND TO A MORE ELY FLOW ON MON WELL N OF THE PATH OF THE SFC LOW. S-SELY SFC WNDS IN COU...STL AND SUS MON MRNG WL SHIFT TO A N-NWLY DIRECTION BHND THE SFC LOW BY LT MON AFTN OR EARLY EVNG. WILL INCLUDE A CHC OF TSRA IN UIN LT MON MRNG WHERE MDLS DEPICT THE BEST POTENTIAL OF QPF WELL LEFT OF THE TRACK OF THE SFC LOW. ALTHOUGH CLOUD CEILINGS SHOULD LOWER DURING THE DAY ON MON AT THE TAF SITES LOOKING AT THE MDL RH FCSTS...PLAN TO KEEP THE PREVAILING CEILING HGTS IN THE VFR CATAGORY THRU THE TAF FCST PD. GKS && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 1105 PM MDT SUN MAY 18 2008 .UPDATE... BAND OF ECHOES CONTINUES ON RADAR OVER LIBERTY AND NORTHEAST CHOUTEAU COUNTIES. NOT SURE HOW MUCH IS REACHING THE GROUND AS EVENING INVERTED V UPPER AIR SOUNDING FROM TFX SHOWING PLENTY OF DRY AIR SUB CLOUD. ALSO WHEN ECHOES WENT OVER ROCKY BOY RAWS NO PRECIP WAS MEASURED. CANADIAN RADARS DO SHOW MORE ECHOES OVER SOUTHERN ALBERTA...MOVING SOUTHEASTWARD...AND CAN SEE CONTINUED SHOWER THREAT OVER NE MT...POSSIBLY CLIPPING OUR NORTHEAST COUNTIES...ALONG 850 MB THERMAL GRADIENT. THINK 18Z GFS OVERDONE IN ENHANCING CLOUDS AND PRECIPITATION OVERNIGHT IN A BAND BUILDING IN FROM THE W...AS THIS DOES NOT SEEM TO BE TAKING SHAPE OR VERIFYING AT THIS POINT. MORE CONSERVATIVE NAM AND RUC LOOK MORE REALISTIC WITH JUST SPOTTY PRECIP EAST OF THE CONTINENTAL DIVIDE. REILLY && .AVIATION... UPDATED 0505Z. VFR CONDITIONS WILL GENERALLY CONTINUE ACROSS NORTH CENTRAL AND SOUTHWEST MONTANA THROUGH AT LEAST MONDAY EVENING. THE UPPER LEVEL RIDGE OVER THE WESTERN CONUS WILL CONTINUE THE MAINLY HIGH CLOUDINESS OVER THE AREA THROUGH TONIGHT WITH LIGHT WESTERLY WINDS. A SURFACE BOUNDARY WILL CONTINUE TO SWING SOUTHWEST THROUGH NORTH CENTRAL AND CENTRAL MONTANA INTO MONDAY. MID LEVEL CLOUDINESS AND THE CHANCE FOR SHOWERS WILL INCREASE OVER NORTH CENTRAL AND CENTRAL MONTANA ON MONDAY AS A SERIES OF DISTURBANCES MOVE THROUGH THE WEST-NORTHWESTERLY FLOW ALOFT. THE MAIN FOCUS FOR SHOWERS WILL BE ALONG THE SURFACE BOUNDARY (INCLUDING KHLN KGTF KLWT TERMINALS). THE AIRMASS WILL ALSO BECOME SLIGHTLY UNSTABLE NEAR THIS BOUNDARY MONDAY AFTERNOON FOR A SLIGHT CHANCE OF THUNDERSTORMS THERE. HOWEVER...AM NOT EXPECTING ENOUGH OF A CHANCE (OR RESULTANT COVERAGE) TO MENTION IN TERMINAL FORECASTS. COULSTON && .PREV DISCUSSION... /ISSUED 610 PM MDT SUN MAY 18 2008/ TONIGHT THROUGH TUESDAY...A NORTHWEST FLOW ALOFT AHEAD OF AN UPPER RIDGE OF HIGH PRESSURE WILL BE OVER THE AREA THROUGH MONDAY. FOR TONIGHT IT STILL LOOKS LIKE AT LEAST A FEW SHOWERS AND THUNDERSTORMS WILL DEVELOP TOWARDS THE CANADIAN BORDER THIS EVENING. FOR LATE TONIGHT MODELS INDICATE A BAND OF MOISTURE WILL DEVELOP FROM THE NORTHWEST ZONES TO THE CENTRAL ZONES. THERE APPEARS THERE WILL BE SOME LIFT ASSOCIATED WITH IT SO HAVE ADDED SOME SLIGHT CHANCE TO CHANCE POPS FOR THAT AREA AFTER MIDNIGHT TONIGHT INTO MONDAY. THIS BAND IS EXPECTED TO SPREAD NORTHEAST DURING THE DAY AND EVENING. ALSO EXPECT SOME WEAK INSTABILITY SO WILL MENTION THE THREAT OF THUNDERSTORMS. THE UPPER RIDGE OF HIGH PRESSURE MENTIONED ABOVE MOVES OVER THE AREA LATE MONDAY NIGHT SO EXPECT THE THREAT OF PRECIPITATION TO END. THEN ON TUESDAY THERE WILL BE A HARBINGER OF A SIGNIFICANT WEATHER CHANGE. AN UPPER TROUGH OF LOW PRESSURE WILL BE NEAR THE PACIFIC NORTHWEST COAST BY LATE IN THE DAY. THE ASSOCIATED COLD FRONT IS EXPECTED TO BE NEAR A CUT BANK TO BUTTE LINE BY LATE AFTERNOON. THERE WILL BE SOME INSTABILITY NEAR AND AHEAD OF THE FRONT. HOWEVER THE MAIN MOISTURE LAGS BEHIND THE COLD FRONT. DO EXPECT SOME THUNDERSTORMS IN THE WEST BY LATE AFTERNOON. WILL ALSO MENTION A THREAT OF GUSTY WINDS WITH THEM. IN THE FAR EAST THE AIRMASS APPEARS TOO DRY AND NOT UNSTABLE ENOUGH TO SUPPORT THUNDERSTORMS SO WILL REMOVE THEIR MENTION FROM THE FORECAST. BLANK TUESDAY NIGHT THROUGH FRIDAY NIGHT...EXPECT A RATHER UNSETTLED AND WET PERIOD OF WEATHER ACROSS THE REGION FOR THE LATER HALF OF NEXT WEEK. A PACIFIC COLD FRONT WILL HAVE MOVED THROUGH THE REGION BY TUESDAY EVENING...AS COOLER AIR GRADUALLY MOVES INTO THE AREA FROM TUESDAY NIGHT THROUGH THURSDAY. AFTERNOON TEMPERATURES WILL AVERAGE CLOSE TO 15 DEGREES BELOW NORMAL BY THURSDAY. ADDITIONALLY...THE CHANCES FOR PRECIP WILL ALSO INCREASE. SCATTERED SHOWERS ARE POSSIBLE AT TIMES TUESDAY NIGHT THROUGH WEDNESDAY...BUT A STEADY RAIN IS POSSIBLE OVER MUCH OF THE REGION ON THURSDAY. SNOW LEVELS SHOULD GENERALLY REMAIN ABOVE 6500 FEET...WITH ACCUMULATIONS POSSIBLE AT TIMES...ESPECIALLY DURING THE OVERNIGHT HOURS. ON FRIDAY...SCATTERED SHOWERS AND COOL TEMPERATURES WILL CONTINUE TO RESIDE OVER THE REGION...AS AN UPPER LEVEL TROF BEGINS TO AFFECT MUCH OF THE WESTERN PORTIONS OF THE U.S. BRUSDA SATURDAY AND SUNDAY...LATEST MODELS INDICATE A DEEP TROUGH OVER THE WESTERN STATES WHICH IS EXPECTED TO SPREAD SHOWERS OVER MUCH OF THE REGION. A NORTHERLY FLOW ALOFT WILL KEEP TEMPERATURES BE BELOW SEASONAL AVERAGES FOR MUCH OF THE NORTH CENTRAL PLAINS AND THE SOUTH WEST MOUNTAINS. SAUCIER && .PRELIMINARY POINT TEMPS/POPS... GTF 59 73 55 79 / 20 20 10 20 CTB 50 71 50 74 / 20 20 20 30 HLN 58 80 54 81 / 10 10 0 20 BZN 47 81 48 84 / 0 10 0 10 WEY 38 70 41 71 / 10 0 0 10 DLN 46 78 47 79 / 0 0 0 20 HVR 47 74 48 80 / 20 10 30 10 LWT 50 69 45 78 / 10 20 10 10 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...REILLY LONG TERM...BRUSDA/SAUCIER AVIATION...COULSTON WEATHER.GOV/GREATFALLS mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 737 PM EDT MON MAY 19 2008 .SYNOPSIS... A LARGE UPPER LOW PRESSURE SYSTEM CENTERED OVER FAR NORTHEASTERN VERMONT THIS AFTERNOON IS ASSOCIATED WITH A WRAP AROUND BAND OF RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS ACROSS MUCH OF THE NORTH COUNTRY. THESE SHOWERS WILL CONTINUE THROUGH THIS EVENING...AND BE HEAVIEST OVER NORTHERN NEW YORK AND ALONG THE WEST SLOPES OF THE GREEN MOUNTAINS IN NORTHERN VERMONT. THIS UPPER LOW PRESSURE SYSTEM WILL REMAIN ANCHORED OVER THE NORTHEASTERN UNITED STATES AND SOUTHEASTERN CANADA THROUGH THE REMAINDER OF THE WORK WEEK BRINGING CONSIDERABLE CLOUDINESS AND TEMPERATURES BELOW SEASONAL AVERAGES. PERIODIC RAIN SHOWERS ARE ALSO POSSIBLE...ESPECIALLY WEDNESDAY AND WEDNESDAY NIGHT. HOWEVER...MUCH OF THE RAINFALL IS EXPECTED TO BE ON THE LIGHT SIDE. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 246 PM EDT MONDAY...RATHER ROBUST RAIN BAND EXTENDING N-S ACROSS FAR NERN NY AND THROUGHOUT THE CHAMPLAIN VLY AT 1815Z. THIS BAND IS LOCATED ON THE BACK SIDE OF THE H5 LOW OVER FAR NERN VT. IT/S LIKELY THAT THE INVERSION EVIDENT IN GFS MODEL SOUNDINGS THIS AFTN AT KBTV IS RESULTING IN BLOCKED FLOW AND OROGRAPHIC LIFT BEING FELT UPSTREAM OF THE MTNS BY 15-20 KM ON THE VT SIDE OF THE VALLEY. 2-4KM FLOW IS WLY AT 30-40 KTS PER KCXX VAD...AND IS CONTRIBUTING TO THE OROGRAPHIC EFFECTS BEING FELT IN THE CHAMPLAIN VALLEY. AT KBTV...RAINFALL HAS ACCUMULATED 0.20"...AND ANOTHER ONE TO TWO TENTHS IS EXPECTED THROUGH 03Z THIS EVENING. UPR TROUGH IS QUITE COLD...WITH 0HR RUC 850MB TEMPS OF -1 TO -2C OVER THE NORTH COUNTRY THIS AFTN. CONSIDERABLE BRIGHT BANDING IS EVIDENT ON KCXX COMPOSITE REFLECTIVITY...AT A HGT OF 1900-2600 FT MSL. THUS...WE BELIEVE PCPN IS MIXING WITH WET SNOW ABOVE 1900 FT OR SO...AND MAY RESULT IN A MINIMUM SNOW ACCUMULATION FROM 2500 FT TO SUMMIT LVL OF UP TO 1 INCH THROUGH TONIGHT. AS MAIN 500MB VORT SHIFTS EWD TONIGHT...WRAP-AROUND BAND WILL LIKELY SHIFT EWD AS WELL WITH DIMINISHING COVERAGE OF PCPN AFTER 03Z. SKIES SHOULD REMAIN MOSTLY CLOUDY AND THIS WILL LIMIT THE RANGE OF LOW TEMPERATURES ACROSS OUR FORECAST AREA FOR TOMORROW MORNING. LOW TEMPERATURES ARE EXPECTED TO RANGE FROM 40-42F IN THE CHAMPLAIN VALLEY...TO THE MID TO UPR 30S ACROSS MUCH OF THE REMAINDER OF THE FORECAST AREA BELOW 2000 FT. ABOVE 2000 FT...LOOKING AT LOW TEMPERATURES MAINLY IN THE UPR 20S TO LOWER 30S. THE WELL-MIXED CONDITIONS SHOWN ON THE NAM MODEL SOUNDINGS DID NOT MATERIALIZE WEST OF THE GREEN MTNS TODAY OWING TO STABILIZING EFFECTS OF PCPN. WLY GRADIENT FLOW IS DECREASING ON THE SYNOPTIC-SCALE OVERNIGHT AND 10-M WINDS SHOULD GENERALLY BE SWLY AT 5-10 KTS MOST SECTIONS TONIGHT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 246 PM EDT MONDAY...THE BROAD MID-UPR LEVEL TROUGH WILL REMAIN AS OUR CONTROLLING WX FEATURE THROUGHOUT THE SHORT-TERM FORECAST PERIOD. ON TUESDAY...DEEP-LAYER RH LESSENS AND WRN PORTION OF UPR TROUGH WILL BE DIGGING ACROSS THE NRN GREAT LAKES REGION WITH JUST WEAKLY CYCLONIC FLOW ALOFT OVER THE NORTH COUNTRY. THESE FACTORS POINT TO PARTIAL CLEARING ACROSS THE REGION TOMORROW /ALSO SUPPORTED BY NAM FORECAST SOUNDINGS/...WITH ONLY A SLIGHT CHANCE OF PRECIPITATION IN MOST VALLEY LOCATIONS. WILL CONTINUE TO CHANCE POPS FOR -SHRA ACROSS MTN LOCATIONS...BUT OVERALL QPF SHOULD BE LIGHTER THAN OBSERVED TODAY. ALSO...WITH 850MB TEMPERATURES MODERATING TO NEAR +2C TOMORROW...WE SHOULD SEE HIGH TEMPERATURES REACH 60-62F IN THE KBTV AREA AND INTO THE 50S ACROSS THE 1-2 KFT ELEVATION BAND. SFC WINDS SHOULD CONTINUE LIGHT FROM THE SW AT AROUND 10KTS DURING THE LATE MORNING THROUGH AFTN HOURS. THIS WIND REGIME SHOULD ALSO HELP TO DECREASE CLOUD COVER EAST OF THE ADIRONDACKS /I.E...IN THE CHAMPLAIN VALLEY/ AND ALSO POINTS EAST OF THE GREENS IN ORANGE/WINDSOR COUNTIES. TUESDAY NIGHT INTO WEDNESDAY...HAVE FOLLOWED CLOSELY THE 12Z GFS SOLN FOR THIS PORTION OF THE FORECAST DUE TO GOOD TEMPORAL CONTINUITY OF THE MODEL. WRN PORTION OF UPR TROUGH WILL BE DIGGING AND APPROACHING FROM THE WEST WITH INCREASING DPVA INTO THE EASTERN GREAT LAKES AREA BY LATE TUESDAY NIGHT. WILL HIGHLIGHT LIKELY POPS IN THE FORECAST FOR RAIN SHOWERS DURING ESPECIALLY WEDNESDAY AFTN...WITH TIMING OF BEST SYNOPTIC SUPPORT FOR ASCENT. MOISTURE IS SOMEWHAT LIMITED WITH THIS FEATURE WITH NO SIGNIFICANT GULF OF MEXICO OR SWRN ATLANTIC OCEAN SUPPORT. THUS...HAVE KEPT QPF FOR THE PERIOD 06Z WED THROUGH 12Z THURSDAY IN THE 0.1-0.2" RANGE OVER THE NORTH COUNTRY. OTHERWISE...NOT LOOKING AT ANY SIGNIFICANT CHANGES IN THE BLW AVG TEMPERATURES DURING THE PERIOD WITH LOWS IN THE UPPER 30S TO LOW 40S AND HIGHS IN THE MID 50S TO NEAR 60F IN THE VALLEYS. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 246 PM EDT MONDAY...LATEST MEDIUM RANGE OPERATIONAL AND ENSEMBLE SOLNS REMAIN IN OVERALL GOOD AGREEMENT ADVERTISING SEASONABLY COOL AND SHOWERY REGIME THU/FRI TO TRANSITION TO DRIER/WARMER WX BY LATER NEXT WEEKEND INTO EARLY NEXT WEEK. THIS IDEA ALSO HAS BROAD SUPPORT FROM LAST NIGHT/S EURO AND CANADIAN RUNS. WILL ADVERTISE HIGHEST THREAT OF PCPN/SHRAS ON THURSDAY AS CORE OF ADDL UPPER LVL COOL POOL SAGS SOUTHWARD ACROSS AREA...AND CONTINUE THREAT OF SCT ACTIVITY AGAIN ON FRIDAY...THOUGH TO A LESSER DEGREE AS SYSTEM EASES EAST/SOUTH OF AREA. DESPITE FAIRLY DECENT BNDRY LYR MIXING...MAX TEMPS TO REMAIN ON THE COOL SIDE...AVERAGING SOME 8-12 DEG BELOW LATE MAY NORMALS. THEREAFTER...BROAD MID TO UPPER LVL RIDGING SLOWLY BUILDS EASTWARD ACROSS THE CONUS BY LATER NEXT WEEKEND INTO EARLY NEXT WEEK. THUS EXPECT AN OVERALL DRYING TREND WITH A MODERATION IN TEMPERATURES BY SATURDAY...AND ESP BY SUN/MON TIME FRAME AS MID LVL TEMPS RESPOND NICELY TO BUILDING HEIGHTS AND BROAD-SCALE SUBSIDENCE. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... THROUGH 00Z WEDNESDAY...MOSTLY VFR AND MVFR CONDITIONS OVER THE NEXT 24 HOURS AS LARGE-SCALE UPPER LOW DUMBBELLS ACROSS NRN NEW ENGLAND/SRN CANADA. CURRENTLY THERE IS A BRIEF LULL IN PCPN ACROSS THE AREA BUT AFT MIDNIGHT AN ADDL MOISTURE PLUME SEEN NICELY ON WV IMAGERY WILL DROP SOUTHWARD OVERNIGHT AND LIKELY BRING ANOTHER ROUND OF -RA AND/OR -SHRAS TO NORTHERN TAF SITES BY 6Z. CIGS WILL MOSTLY BE 030-040 THROUGH THIS PERIOD EVEN THOUGH THERE WILL BE A SMALL BREAK EARLY THIS EVENING WITH SOME SCT CLD DECKS. IT WILL BE SHORT LIVED...WITH ALL LOCALS HAVING CIGS AGAIN BY 03Z. AFT 18Z IT LOOKS LIKE THERE COULD BE A SMALL BREAK IN THE ACTION WITH ALL LOCATIONS GOING VFR. WNDS WILL BE OUT OF THE WEST WITH GUSTS TO 15 KTS...BEFORE THEY BACK MORE TO THE SOUTHWEST BY TOMORROW MORNING. 00Z WEDNESDAY THROUGH SATURDAY...THIS PERIOD WILL BE DOMINATED BY SHOWERS AS AN UPPER LEVEL TROUGH BECOMES ENTRENCHED OVER THE AREA. EXPECTED VFR CONDITIONS WITH TEMPO MVFR DURING AFTERNOON RAIN SHOWERS AS DAYTIME HEATING DESTABILIZES THE ATMOSPHERE. BEST CHANCE FOR WIDESPREAD RAIN LOOKS LIKE WEDNESDAY EVENING AND FRIDAY AFTERNOON AS A MORE POTENT UPPER LEVEL SHORTWAVES ARE PROGGED TO MOVE OVER THE AREA. CIGS WILL GENERALLY BE 020-040 AGL DURING THIS PERIOD. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS SHORT TERM...BANACOS LONG TERM...JMG AVIATION...JMG/DUMONT ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 945 PM EDT SUN MAY 18 2008 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS THE AREA TONIGHT FOLLOWED BY HIGH PRESSURE MONDAY AND EARLY TUESDAY. ANOTHER COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND NORTHEAST FOR THE END OF THE WEEK AND WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM SUNDAY...A DEEP MIXED LAYER (6000-7000 FT DEEP) HAS SUPPORTED SCATTERED SHOWERS AND THUNDERSTORMS MAINLY NORTH OF HIGHWAY 76 THIS EVENING DESPITE SURFACE DEWPOINTS IN THE 40S AND 50S. THE INVERTED-V SHAPE TO THE SOUNDINGS ARE TYPICAL OF THOSE IN THE WESTERN U.S. AND HAVE SUPPORTED WIND GUSTS IN THE 25-45 MPH RANGE NEAR THE CONVECTIVE ACTIVITY. CONVECTION SHOULD GRADUALLY DIMINISH BETWEEN MIDNIGHT AND 2 A.M. WITH THE FOCUS SHIFTING TO INCREASINGLY SURFACE-BASED INSTABILITY OUT OVER THE COASTAL WATERS. THE SURFACE COLD FRONT LIES FROM JUST NORTH OF RALEIGH TO NEAR GREENSBORO AND HICKORY AT 9 PM. RADAR COMPOSITES SHOW SOME CONVECTION HAS RECENTLY REDEVELOPED ALONG THE FRONT ITSELF. HOWEVER FORECAST SOUNDINGS FROM THE LATEST RUC AND 18Z NAM SHOW INCREASINGLY WEAK LAPSE RATES IN THE MID-LEVELS WHICH SHOULD BEGIN SUPPRESSING LAND-BASED CONVECTION AFTER MIDNIGHT. WE HAVE MADE NO SIGNIFICANT CHANGES TO FORECAST LOWS TONIGHT...UPPER 50S INLAND AND LOWER 60S AT THE COAST. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 PM SUNDAY...THE MAIN AREAS OF LIFT WILL REMAIN NORTH OF THE FORECAST AREA MONDAY WITH AN UPPER LOW ACROSS NEW ENGLAND. THIS FEATURE WILL PUSH A COLD FRONT ACROSS THE AREA TUESDAY EVENING AS ADDITIONAL IMPULSES IN THE NORTHWEST FLOW CREATE ADDITIONAL LIFT. MODERATE INSTABILITY SHOWN TO DEVELOP AHEAD OF THE COLD FRONT DURING TUESDAY...ALONG WITH DEWPOINTS POOLING INTO THE 60S...COUPLED W/ THE AFOREMENTIONED LIFT THINK THE POTENTIAL FOR A FEW STRONG TO SEVERE TSTMS WILL EXIST. AFTER THE INITIAL INHIBITION ERODES DURING TUESDAY HAVE STEPPED POPS UP TO GOOD CHANCES LATER IN THE AFTERNOON AND THE FIRST PART OF THE EVENING. DECREASED POPS THEREAFTER WITH THE FOCUS SHIFTING TO THE SOUTH AND OFFSHORE. OTHERWISE FOR TUESDAY...EXPECT WINDY CONDITIONS AS A RESULT OF MIXING WITH SHARP LOW-LEVEL LAPSE RATES EXPECTED...AND THE TIGHT PRESSURE GRADIENT. ALSO LEANED TOWARD THE WARMER MAV GUIDANCE GIVEN SOUTHWESTERLY VS FLOW OFF THE COOLER OCEAN. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 3 PM SUNDAY...STORY OF THE LONG TERM WILL BE TWO MAIN REGIMES. FIRST WILL LAST THROUGH FRI WITH COLD FRONT STALLED ALONG OR JUST S OF THE AREA. A COUPLE SFC WAVES...ASSOCIATED WITH SOME WEAK 5H WAVES...WILL MOVE ALONG THE BOUNDARY RESULTING IN SOME CONVECTION. PRECIP COVERAGE IS GOING TO BE LOCALIZED WITH LOCATION DEPENDANT ON WHERE SFC BOUNDARY IS. GUIDANCE AND HPC ALL POINT TO FRONT STALLING JUST S OF THE CWA WHICH MAY RESULT IN ILM AREA GETTING VERY LITTLE IF ANY PRECIP. DID NOT CHOSE TO MAKE ANY CHANGES TO CURRENT POP FORECAST...SLIGHT CHC ACROSS THE S THU NIGHT AND FRI. DRIER AND SOMEWHAT COOLER AIR MASS MOVES OVER THE REGION LATER FRI AND REMAINS THROUGH THE WEEKEND. DEEP UPPER TROF BUILDS S OVER OR JUST OFF THE E CONUS FRI DEPENDING ON WHICH MODEL IS CORRECT. BOTH THE GFS/ECMWF SOLUTIONS RESULT IN A DRY FORECAST WITH SFC RIDGE IN PLACE. MAIN DIFFERENCE WOULD BE TEMPS...GFS KEEPS THE TROF AXIS CLOSER TO THE COAST AND YIELDS COOLER TEMPS. FAVORED A BLEND OF THE GFS/ECMWF WHICH IS SIMILAR TO THE HPC SOLUTION. && .AVIATION /0Z MONDAY THROUGH THURSDAY/... SHOWERS SHOWING UP ON THE RADAR TO OUR NORTH AND WEST WILL REMAIN MOSTLY TO OUR NORTH TONIGHT. INLAND TERMINALS SUCH AS KFLO AND KLBT STAND THE BEST CHANCE AT SEEING SHOWERS OVER THE NEXT FEW HOURS. ANYTHING THAT FALLS WILL BE LIGHT. ALL OF THE MOISTURE IS CONFINED TO THE MID LEVELS BETWEEN 8K AND 12K WITH VERY DRY AIR DOWN TO THE SURFACE. ELSEWHERE THE STORY THIS EVENING HAS BEEN THE GUSTY WINDS OUT OF THE SOUTHWEST. THESE WINDS SHOULD PERSIST AN HOUR OR TWO AFTER SUNSET BEFORE GRADUALLY DIMINISHING. WINDS WILL SHIFT INTO THE WEST TO WEST NORTH-WEST AFTER MIDNIGHT WITH A COLD FRONTAL PASSAGE. OUTLOOK MONDAY THROUGH THURSDAY...LOWER PRESSURE TO AFFECT THE AREA FROM THE WEST TUESDAY INTO EARLY WEDNESDAY...AND COULD BRING AN EXTENDED PERIOD OF MVFR/IFR CONDITIONS FROM SHRA/TSRA. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM SUNDAY...THE STRONG GRADIENT WINDS OF EARLIER TODAY ARE BEGINNING TO DECREASE AS THE LOW LEVEL JET AXIS BEGINS TO SET UP FARTHER OFFSHORE. THE SURFACE COLD FRONT WELL INLAND ACROSS NORTH CAROLINA WILL MAKE IT TO THE COASTLINE AROUND DAYBREAK. UNTIL THEN MOST LOCATIONS WILL SEE WESTERLY WINDS AT 10-20 KNOTS. THE PRIMARY EXCEPTION TO THIS WILL BE NORTH OF CAPE FEAR THIS EVENING WHERE MASSED CONVECTIVE OUTFLOW HAS TEMPORARILY TURNED WINDS NORTHERLY. THIS OUTFLOW BOUNDARY IS EASILY VISIBLE ON RADAR IMAGERY AND COULD AFFECT LOCATIONS NORTH OF CAPE FEAR UNTIL MIDNIGHT. SEAS WILL REMAIN 6 FT OR GREATER AWAY FROM SHORE FOR THE NORTH CAROLINA COASTAL WATERS TONIGHT...BUT HAVE LIKELY ALREADY DIMINISHED BELOW 6 FT FOR THE SC WATERS. AFTER COLLABORATION WITH THE CHS OFFICE WE WILL LET THE SMALL CRAFT ADVISORY CONTINUE AS EARLIER SCHEDULED...EXPIRING AT 6 AM MONDAY. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 PM SUNDAY...WESTERLY FLOW AT THE ONSET OF THE PERIOD WILL BACK TO THE SOUTHWEST BY MONDAY NIGHT. THE FLOW WILL STRENGTHEN DURING TUESDAY AS THE PRESSURE TIGHTENS AHEAD OF THE NEXT COLD FRONT. THE STRONG SOUTHWEST WIND TUESDAY WILL VEERING TO AN OFFSHORE DIRECTION BY TUESDAY EVENING AS THE SOUTHWARD MOVING COLD FRONT MOVES INTO THE PICTURE AND STALLS. REEFCAST AND WNA OUTPUT SHOW SEAS EXCEEDING SMALL CRAFT THRESHOLDS DURING TUESDAY...PEAKING IN THE EVENING. SEAS WILL SUBSIDE DURING TUESDAY NIGHT AS THE WIND BECOMES OFFSHORE AND WEAKENS. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 3 PM SUNDAY...WEAKENING SFC BOUNDARY/REMAINS OF COLD FRONT WILL BE STALLED ACROSS OR JUST S OF THE WATERS THROUGH THE FORECAST PERIOD. PRESENCE OF BOUNDARY KEEPS GRADIENT OVER THE WATERS WEAK...BUT DOES POSE A PROBLEM WITH RESPECT TO WIND DIRECTION. ALONG AND S OF THE BOUNDARY WINDS WILL BE W TO SW WHILE ON THE N SIDE OF THE BOUNDARY WINDS WILL BE NW TO N. SPEEDS IN THE 10 TO 15 KT RANGE WILL RESULT IN 2 TO 4 FT SEAS THROUGH MUCH OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR AMZ250-252- 254-256. && $$ NEAR TERM...TRA SHORT TERM...SRP LONG TERM...III AVIATION...HEDEN nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 746 PM EDT MON MAY 19 2008 .SYNOPSIS... LOW PRESSURE MOVES ACROSS THE AREA TONIGHT AND TUESDAY. AN UPPER LEVEL LOW REMAINS OVER THE AREA THROUGH THE BALANCE OF THE WEEK KEEPING THE MENTION OF PRECIPITATION IN THE FORECAST. && .NEAR TERM /THROUGH TUESDAY/... 23Z SFC ANALYSIS ILLUSTRATES LOW PRES OVER SERN MO WITH A WARM FRONT EXTENDING E THRU ERN KY AND FAR WRN WV. LOW PRES MOVES ENE TNGT SPREADING WDSPRD RA TO THE CWA. RUC13/SREF/GEFS/NAM12 ALL AGREE ON CAT POPS OVERNIGHT THUS RAISED THEM TO 90-100%. 88D CONTS TO RUN HOT DUE TO BRIGHT BANDING...SO BE CAUTIOUS WHEN SEEING HIGHER RETURNS AND ASSOCIATED DOPPLER ESTIMATED RAIN RATES. MEAN QPF FM AREA SREF PLUMES POINT TO A HALF TO ONE INCH BASIN RNFL. THE MOST INTENSE QPF SHALL OCCUR JUST AHEAD OF FROPA WHICH IS SCHEDULED AROUND 12Z +/- 3HRS. THIS ALSO COINCIDES WITH THE STRONG H2 AGEO WIND DIV...H8 LLVL SPEED CONV...AND HIGHEST H10-H7 MSTR FLUX CONV. DID NOT RULE OUT AN ISOLD TRW...HWVR THERMODYNAMIC PROFILES ARE MARGINAL AT BEST. SHOWALTER INDEX DIPS TO 0C IN THE HEADWATERS OF THE TUG BASIN...SO ANY CHC OF THUNDER SHOULD OCCUR THERE. NW WINDS AND SATURATED LLVLS TUES MRNG OWE TO -RA AND -DZ MOST OF THE MRNG. BL DRIES OUT EVER SO SLIGHTLY TUES AFTN IN THE W ALLOWING SOME SUNSHINE. MEANWHILE...IN THE MTNS LOOK FOR CLOUDS AND DZ TO PERSIST. GENERALLY WENT ON THE WARM SIDE OF GUIDANCE FOR TEMPS WITH CLOUDS AND PRECIP ABOUND. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/... MODELS AGREE ON THE GENERAL PATTERN WITH AN UPPER LOW PROVIDING A NORTHWEST WIND FLOW WITH IMPULSES ROTATING AROUND IT. HOWEVER...MODELS DIFFER A BIT IN THE TIMING OF THESE IMPULSES. TIMING ON THESE IMPULSES ARE NOTORIOUS FOR CHANGING...THEREFORE WILL BE FAIRLY GENERIC WITH POPS. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... MODELS SHOW A HIGH PRESSURE SYSTEM BUILDING IN ON FRIDAY...AND PERSISTING THROUGH THE WEEKEND. THIS WILL PROVIDE DRY WEATHER AND WARMING CONDITIONS...AS UPPER LOW SLIDES OFF TO THE EAST. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... PCPN CONTS TO OVERSPREAD THE AREA ALONG AND S OF HTS-CRW-BKW. THIS AREA SHIFTS N AND INCS IN AREAL CVRG DURING THE OVERNIGHT. MVFR WX CAN BE EXPECTED WITH THE RA AHEAD OF THE WARM FRONT THRU 8Z OR SO. THE COLD FRONT CROSSES TUESDAY MRNG BRINGING A PERIOD OF IFR WX TO ALL TERMINALS. EKN AND ESP BKW SHALL SEE IFR WX THRU TUES MRNG BEFORE CONDS LIFT TO MVFR. RA GRADUALLY TAPERS OFF TO DZ BEFORE ENDING FM W TO E IN THE AFTN. IT IS QUITE PSBL FOR BKW TO BE EXPERIENCING DZ 24HRS FM NOW. AVIATION OUTLOOK /AFTER 0Z WED/...NO SIG WX EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...29 NEAR TERM...29/30 SHORT TERM...RPY LONG TERM...RPY AVIATION...29 oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 132 AM EDT MON MAY 19 2008 .SYNOPSIS... AN UPPER LEVEL TROUGH SWEEPS THROUGH TONIGHT. A CLIPPER SYSTEM MOVES THROUGH MONDAY NIGHT INTO TUESDAY. UNSETTLED WEATHER UNDERNEATH A LOW PRESSURE THROUGH MID WEEK. && .NEAR TERM /THROUGH TODAY/... ELONGATED AREA OF MID LVL ENERGY CONTS TO DROP S THRU THE OH VLY. TCU ARE VISIBLE OVER CNTRL KY AND SERN OH OWING TO RADAR RETURNS ON THE LATEST 88D MOSAIC. RUC13/WRFNMM/SREF/NAM12 ALL ILLUSTRATE RW BREAKING OUT IN THE MTNS BTWN 1-4Z. GIVEN RECENT RADAR TRENDS AFOREMENTIONED MDLS ARE VERIFYING RATHER WELL. UPDATED POPS TO LKLY AND CAT FOR THE NRN AND CNTRL WV MTNS THIS EVNG. FARTHER W...WITH DWPTS IN THE L-M 30S ATMS IS MORE STABLE...SO A DRY FCST HOLDS. CLOUDS COLLAPSE IN LARGE PART AFTER MIDNIGHT LEAVING A CLEAR OR PARTLY CLOUDY SKY. THINK WE MAINTAIN ENOUGH WIND AT TOP OF BOUNDARY LAYER TO PREVENT WIDESPREAD FOG...BUT INCLUDED SOME IN THE DEEPER EASTERN VALLEYS. RAN CLOSER TO MAV IN GENERAL FOR OVERNIGHT LOWS IN THE EAST...CLOSER TO COOLER MET IN THE WEST WITH EARLIER CLEARING. MONDAY WILL DAWN WITH SUNSHINE AREAWIDE WITH SURFACE HIGH PRESSURE RIDGE PAYING THE BRIEFEST OF VISITS. THE JUMPY WEATHER PATTERN CONTINUES THOUGH...AS A CLIPPER-TYPE DISTURBANCE RACES DOWN THE BACK SIDE OF THE H500 TROUGH INTO THE CENTRAL OHIO VALLEY. MODELS ACTUALLY IN DECENT AGREEMENT FOR SUCH A SYSTEM. SHOULD SEE MID-LEVEL CLOUDS INCREASE BY MID-AFTERNOON...AND THEN HAVE CHANCE POPS INTO THE SOUTHWESTERN THIRD OF CWA BEFORE 00Z TUE FOR LIGHT QPF. STAYED CLOSER TO MAV FOR HIGHS...EXCEPT WENT SOME 5-6 DEGREES ABOVE IN THE HTS VICINITY. THINK MODEL IS OVERDOING THE INFLUENCE OF CLOUDS HERE. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... MODELS REMAIN FAIRLY CONSISTENT WITH THE HANDLING OF S/W TROUGH ROTATING AROUND UPPER LEVEL LOW PRESSURE OVER QUEBEC OVERNIGHT MONDAY INTO TUESDAY. THE TRACK OF ASSOCIATED WEAK SFC LOW CONTINUES TO BE JUST SOUTH OF CWA...WITH THE FOCUS OF THE MOST ORGANIZED PRECIPITATION REMAINING IN THE SOUTHERN COAL FIELDS AND SW VA. TRIED TO TIME HIGHEST POPS WITH BEST FRONTOGENETIC FORCING...WHICH THE NAM12 SHOWS TO BE OVER SOUTHERN AREAS CENTERED AROUND 06Z TUESDAY. SREF IS IN DECENT AGREEMENT FOCUSING BEST 6HR POP DURING THAT TIME FRAME. LEFT CHC POPS FROM ABOUT CRW NORTH. SYSTEM DEPARTS DURING TUESDAY AFTERNOON...GIVING A VERY BRIEF BREAK TO THE AREA. HOWEVER...NAM AND GFS BOTH BRING YET ANOTHER S/W TROUGH/VORT MAX THROUGH DURING THE MORNING HOURS ON WEDNESDAY. FOLLOWED THE NAM12 FOR THIS FEATURE...WHICH SHOWS A SLIGHTLY WEAKER TROUGH THAN GFS...WHICH MAKES SENSE GIVEN THE FAST NW FLOW. CARRIED ONLY SCHC POPS FOR MOST OF AREA WITH NOT MUCH FORCING DEPICTED. FOR TEMPS...RAISED LOWS A FEW DEGREES TUESDAY AND WEDNESDAY AS CLOUDS AND PRECIP WILL KEEP TEMPS UP. STAYED CLOSE TO GUIDANCE FOR HIGHS. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ONE MORE WEAK LOW WILL MOVE JUST SOUTH OF AREA ON THURSDAY AFFECTING MAINLY THE SOUTHERN PORTIONS OF CWA. MAINTAINED CHC POPS FOR THIS AREA WHILE KEEPING SE OHIO COUNTIES DRY. THE UPPER LEVEL LOW WHICH HAS BEEN CONTROLLING THE WX OVER THE EAST FOR THE PAST SEVERAL DAYS WILL FINALLY SHIFT EASTWARD TO JUST OFF THE EAST COAST BY FRIDAY. GFS AND ECMWF CONTINUE TO DEVELOP AN OMEGA BLOCK OVER CONUS FOR THE WEEKEND...WITH DEEP TROUGHS ALONG BOTH WEST AND EAST COASTS. CWA WILL BE ON THE WESTERN FRINGE OF THE EAST COAST TROUGH KEEPING NW FLOW GOING...ALBEIT DRY. STRONG RIDGE WILL BUILD IN EARLY NEXT WEEK AS THE BLOCK TRIES TO BREAK DOWN WITH BOTH TROUGHS BEGINNING TO LIFT. GENERALLY FOLLOWED GMOS/PREVIOUS FCST FOR MAXT THROUGH THE EXTENDED...WITH A SLIGHT NUDGE UPWARD A DEGREE DAYS 6-7. RAISED MINT A FEW DEGREES THROUGHOUT THE EXTENDED/MAINLY SOUTH/ TO ACCOUNT FOR SOMEWHAT OF DEWPOINT GRADIENT OVER NE KY/SOUTHERN WV. THIS SEEMS REASONABLE CONSIDERING THAT THE TROUGH WILL HAVE LESS OF AN INFLUENCE ON THAT PART OF THE CWA. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... REMAINDER OF THE SHOWERS ARE MOVING THROUGH THE BKW AREA... SHOULD BE THE LAST ACTIVITY FOR THE NIGHT. WINDS WILL SUBSIDE A BIT...BUT WILL NOT GO CALM...SO FOG FORMATION SHOULD NOT OCCUR. THIS IS ALSO SUPPORTED BY PROBABILISTIC DATA. WINDS INCREASE AGAIN MONDAY WITH GUSTS TO 20KT AREA WIDE. VFR CEILINGS AND VISIBILITIES EXPECTED THROUGH THE FORECAST PERIOD. AVIATION OUTLOOK /AFTER 06Z TUESDAY/...IFR POSSIBLE IN TSRA TUES EVENING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...CL/30 NEAR TERM...CL/29 SHORT TERM...30 LONG TERM...30 AVIATION...26 oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1112 AM CDT MON MAY 19 2008 .UPDATE... WEAK FRONT/TROUGH WAS BECOMING BETTER ESTABLISHED AND HAD MOVED INTO NORTHWEST OKLAHOMA BY LATE MORNING SHIFTING THE WINDS TO THE NORTH BEHIND IT. MADE ONLY A FEW ADJUSTMENTS FOR TODAY. EXTENDED THE WARMER TEMPERATURES... CURRENTLY IN THE FAR SOUTHWEST PART OF THE CWA... INTO SOUTH CENTRAL OKLAHOMA. RUC INDICATING THE WARM NOSE AHEAD OF THE WEAK FRONT WILL NUDGE INTO THIS AREA WITH HIGHS REACHING INTO THE MID TO UPPER 90S. MEANWHILE... LOWERED SOME OF THE VERY WARM TEMPERATURES IN THE NORTHWEST DOWN A COUPLE DEGREES DUE TO PRESENCE OF NORTH TO NORTHEAST WINDS... ALTHOUGH HIGHS WILL STILL BE SOLIDLY IN THE MIDDLE 90S. && .PREV DISCUSSION... /ISSUED 355 AM CDT MON MAY 19 2008/ DISCUSSION... HOT TEMPERATURES EXPECTED TODAY AHEAD OF A WEAK COLD FRONT THAT WILL PASS SOUTHWARD THROUGH THE REGION THIS AFTERNOON AND TONIGHT. A FEW LOCATIONS MAY COME CLOSE TO RECORD HIGHS...BUT AS A WHOLE... CURRENT FORECAST PUTS MOST LOCATIONS 4 TO 8 DEGREES BELOW TODAYS RECORD HIGHS. A FEW RECORDS: OKC/97...SPS/102...GAG/102...HBR/98 AND PNC/95. SLIGHTLY COOLER TOMORROW AND WEDNESDAY BEHIND FRONT AND INTRODUCTION OF ADDITIONAL CLOUD COVER. LOW CHANCES OF SHOWERS OR VERY HIGH- BASED THUNDERSTORMS WILL REMAIN IN FORECAST TONIGHT NORTH OF MENTIONED FRONTAL BOUNDARY...AND AGAIN TUESDAY NIGHT AND WEDNESDAY AS SAID FRONTAL BOUNDARY LIFTS NORTH AS A WARM FRONT. DEVELOPMENT OF LARGE WESTERN U.S. TROUGH STILL EXPECTED TO OCCUR MID-LATE WEEK. AS THIS OCCURS...MEDIUM RANGE MODELS APPEAR TO HAVE BETTER AGREEMENT ON HANDLING OF UPPER LOW CURRENTLY OVER BAJA REGION. AS THIS FEATURE GETS KICKED EAST AND NORTHEAST...IT WILL GET CAUGHT UP IN MEAN RIDGE POSITION BETWEEN DEVELOPING WESTERN TROUGH AND LARGE EAST COAST TROUGH. THIS COULD PROVIDE LOCATIONS NEAR AND SOUTH OF OKLAHOMA A PROLONGED PERIOD OF CONCENTRATED RAINFALL. CONSENSUS AMONG MODELS IS TO KEEP MAIN IMPACTS OF THIS SYSTEM SOUTH OF OUR CWA AND WE WILL KEEP THE FORECAST WORDED THAT WAY. HOWEVER...THIS WILL NEED TO BE WATCHED CLOSELY. CONVECTION WORKING ITS WAY EASTWARD OFF OF HIGH PLAINS LATE IN THE PERIOD IS STILL UP IN THE AIR. OVERALL PATTERN SUGGESTS THAT IF ANYTHING GETS GOING...IT WILL HAVE A MUCH GREATER NORTHWARD TRAJECTORY THAT EAST GIVEN DEEP LAYER MERIDIONAL FLOW. WILL KEEP LOW POPS IN THE FORECAST FOR LATE WEEK INTO NEXT WEEKEND GIVEN UNCERTAINTIES AS TO EXACT LONGITUDE OF UPPER TROUGH AND MEAN RIDGE AXES AND INCREASING DISAGREEMENT BETWEEN GFS AND ECM. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 93 62 90 63 / 10 10 0 10 HOBART OK 98 63 89 63 / 0 0 0 10 WICHITA FALLS TX 98 63 91 65 / 0 0 0 10 GAGE OK 96 58 88 61 / 0 10 0 20 PONCA CITY OK 92 62 88 62 / 10 20 0 20 DURANT OK 93 63 89 65 / 0 10 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 32/25 ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 157 PM EDT SUN MAY 18 2008 .SYNOPSIS... A DEEP UPPER LEVEL LOW OVER EASTERN CANADA AND THE NORTHEAST U.S. WILL KEEP IT COOL AND UNSETTLED THROUGH MID WEEK. ONE STORM TODAY WILL MAKE RAIN...THEN ANOTHER ON TUESDAY WILL MAKE MORE RAIN. BUT MONDAY WILL BE VERY COLD FOR MID-MAY...AND SOME SNOW ACCUMULATION IS POSSIBLE IN THE NORTH ON MONDAY AS THE COLDEST OF THE AIR MOVES OVERHEAD. TEMPERATURES SHOULD MODERATE TOWARD NORMAL THURSDAY AND FRIDAY AS THE DEEP TROUGH FINALLY SLIDES TO OUR EAST. && .NEAR TERM /UNTIL 5 PM THIS AFTERNOON/... STRATIFORM RAIN AREA HAS CLEARED ALL BUT MY FAR SOUTHEAST COUNTIES AT PRESENT WITH COLD CORE UPPER LOW CROSSING THE EASTERN LAKES AND SPAWNING A FEW LINES OF LOW TOPPED SHOWERS WITH ISOLATED THUNDER AND SEVERAL PEA SIZED HAIL REPORTS ACCORDING TO CLE. NOT EXTREMELY CONCERNED FOR SEVERE HAIL...BUT EXPECT PLENTY OF PEA SIZED HAIL REPORTS ACROSS OUR NORTHWEST THIS AFTERNOON WITH WET BULB ZEROES IN THE 6-7K RANGE. ACTIVITY SHOULD EVENTUALLY SWING INTO THE LAURELS... THE CENTRAL AND NORTH CENTRAL MOUNTAINS AS WELL. HAVE ISSUED A QUICK UPDATE FOR THIS EVOLUTION AND INCREASED POTENTIAL FOR SMALL HAIL AND SOME GUSTY WINDS TO ACCOMPANY ANY SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON. && .SHORT TERM /5 PM THIS AFTERNOON THROUGH TUESDAY/... BRIEF DRYING SHOULD OCCUR AGAIN TONIGHT...AND ONLY WEAK SHORTWAVES WILL PASS OVER NORTHERN PA DURING THE DAY ON MONDAY. THIS IS A MORE-TYPICAL NORTHWEST FLOW...AND HAVE CONFINED HIGHEST POPS TO THE NORTHWEST. SOME LAKE ENHANCEMENT IS LIKELY AS THE TEMPS - BOTH AT THE SFC AND ALOFT WILL BE REALLY COLD FOR MID-MAY. WILL ALSO MENTION SOME SNOW IN THE NORTHERN MOUNTAINS...AND IT COULD EVEN BRIEFLY ACCUMULATE ON THE COLDER/GRASSY SURFACES AGAIN DURING MONDAY MORNING IN THE NW. QUITE A MAY. /OR IS IT MARCH?/ THE TEMPS WILL BE COLDEST ON MONDAY WITH HIGHS ONLY IN THE 40S IN THE NORTH...TO NEAR 60 IN THE SE WHERE DOWNSLOPE AND MORE SUNSHINE WILL HELP THEM ATTAIN THOSE LOFTY NUMBERS. NW WINDS WILL BE QUITE GUSTY ON MONDAY. MONDAY NIGHT LOOKS MAINLY DRY...BUT ANOTHER STORM SHOULD MOVE IN FROM THE SOUTHWEST DURING THE LATE NIGHT OR EARLY TUES MORNING. SO TUESDAY LOOKS WET AT THIS POINT...BUT TIMING THESE LITTLE RIPPLES IN THE FLOW IS STILL NOT AN EASY THING AT DAY3. WILL MAKE A MOVE UP TO LIKELIES FROM CHC POPS AT THIS POINT. TUESDAY ALSO LOOKS JUST A LITTLE BIT MILDER THAN MONDAY BUT STILL ~15 DEGS COOLER THAN NORMAL FOR THIS TIME OF THE YEAR. HIGHS WILL BE MAINLY IN THE 50S/L60S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS HAVE CONTINUED THE TREND OF LAST NIGHT AND HAVE PRETTY MUCH GIVEN UP ON ANY UPPER LEVEL RIDGING FOR THE EASTERN U.S. BEFORE THE END OF THE WEEKEND. OUR ANOMALOUSLY DEEP UPPER LOW IS MOST LIKELY GOING TO STAY PARKED OVER EASTERN CANADA AND NEW ENGLAND FOR THE BULK OF THE FORECAST PERIOD. A HOPE FOR IMPROVEMENT IN TEMPS AND LESS RAIN WILL COME MAINLY FROM A MODIFICATION OF OUR CURRENT AIRMASS AND LESS DIRECT INTRUSIONS OF COLD AIR FROM CENT/NRN CANADA. THIS WOULD HELP OUR TEMPS MODERATE...AND A PERSISTENT NW FLOW WOULD BE A MORE-DRY FLOW PATTERN THAN THE FLOW WE ARE IN NOW...WHICH KEEPS TRANSPORTING SHOTS OF MOISTURE FROM THE GOMEX EVERY 24-36 HRS. THE LONG RANGE GUIDANCE IS POINTING TOWARD AN AMPLIFICATION OF THE CURRENT FLOW -- WITH THE UPPER LOW OPENING UP TO A LONGWAVE TROF OVER THE WESTERN ATLANTIC AND A RIDGE OVER CENTRAL NOAM. THE NORTHERLY FLOW ALOFT WOULD HELP USHER A SFC HIGH DOWN FROM CENTRAL CANADA INTO THE GREAT LAKES AT THE END OF THE WEEK. THIS - AGAIN - SHOULD BE TAKEN WITH A GRAIN OF SALT. BUT IT IS ENOUGH TO KEEP THE LATTER HALF OF THE FORECAST PERIOD /WED NIGHT-SAT/ DRY AT THIS POINT. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... PRECIP ROLLING INTO CENTRAL PA ATTM. EXPECT CIGS/VSBYS TO FREQUENTLY GO BTWN MVFR/IFR WITH PRECIP AND ABUNDANT LLVL MOISTURE. FIRST SLUG OF PRECIP WILL ARRIVE AT MOST TAF SITES PRIOR TO 15Z...WITH A BREAK IN PRECIP ON BACKSIDE BEFORE SECOND SLUG ARRIVES LATE MORNING THRU EARLY AFTN. IR IMAGERY INDICATED A CLEAR LINE OF CLOUDS PUNCHING INTO CENTRAL OH...CONFIDENCE IN THIS ARRIVING IS MINIMAL TO CENTRAL PA AIRFIELDS. RUC IS PROGGING STEADY SHRA TO ARRIVE ARND 16-21Z AT KBFD NORTH OF A WEAK SFC LOW TRACK. THIS SOLUTION ALSO FAVORS WRAPPING DRY AIR INTO KAOO/KUNV/KJST/KMDT MID/LATE AFTN FROM DRY WEDGE PRESENTLY LOCATED IN CENTRAL OH. MVFR CONDS EXPECTED AT MOST AIRFIELDS IN CENTRAL PA UNTIL ARND 21-23Z WHEN PRECIP SHUD SLIDE EAST INTO THE SUSQ- VALLEY. AN ISO TSRA CANNOT BE RULED OUT FOR FAR SE PA THIS AFTN. UPR LVL LOW SLIDES ACROSS SW QUEBEC...PROVIDING A CHILLY/MOIST NW FLOW INTO THE MID- ATLANTI REGION LATE TONIGHT INTO MON MORNING. HIGHER TERRAIN AIRFIELDS IN NW PA EARLY MON COULD SEE LGT SHSN AS COLD AIR WRAPS IN BEHIND UPR LVL LOW. MON AFTN THRU EARLY TUE SHUD REMAIN QUIET AND DRY WITH VFR CONDS. A WEAK SFC LOW DIVES SE TOWARDS KY/TN TUE MORNING...MAY PRODUCE SOME CIRRUS ACROSS SW PA. WEAK SFC RIDGE TRIES TO POKE INTO SOUTHERN GRT LKS WED...BUT MAY STAY WEST OF MID-ATLANTIC REGION ENUF TO KEEP WEAK NW FLOW FOR CENTRAL PA INTO WED/THUR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO/DEVOIR SHORT TERM...DANGELO LONG TERM...DANGELO AVIATION...BEACHLER pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 201 AM EDT SUN MAY 18 2008 .SYNOPSIS... A DEEP UPPER-LEVEL TROUGH WILL DOMINATE THE WEATHER OVER OUR REGION FOR MOST OF THE NEXT 4-6 DAYS. AS THE DEEP TROUGH MOVES OVER THE REGION A SURFACE STORM WILL DEVELOP AND PRODUCE SOME RAIN SUNDAY AND IT WILL DRAG SOME UNSEASONABLY COLD AIR OVER PENNSYLVANIA LATE SUNDAY AND INTO MONDAY. MONDAY WILL BE VERY COLD FOR MID-MAY. THE COLD AIR SHOULD DOMINATE OUR WEATHER UNTIL WEDNESDAY OR THURSDAY. TEMPERATURES SHOULD MODERATE TOWARD NORMAL THURSDAY AND FRIDAY AS THE DEEP TROUGH FINALLY SLIDES TO OUR EAST. && .NEAR TERM /THROUGH TODAY/... A LINE OF SHOWERS WITH A FEW THUNDERSTORMS WILL WORK ITS WAY THROUGH THE LOWER SUSQUEHANNA VALLEY BETWEEN 930 PM AND 11 PM THIS EVENING. A SECOND...SMALLER LINE OF THUNDERSTORMS WILL MOVE ACROSS CENTRAL AREAS BETWEEN 930 AND 11 PM TOO. THE SECOND LINE HAS MORE INTENSE CORES. THE LOCAL MODELS SUGGEST MOST OF THE SHOWER ACTIVITY SHOULD WEAKEN AFTER 11 PM AND MOST OF THE SHOWERS SHOULD END BEFORE 2 AM. THE HIGH RESOLUTION MODELS SUGGEST A SURGE OF WARMER AIR COULD SURGE INTO THE REGION FROM THE SOUTHWEST AHEAD OF THE STRONGER AND MORE SIGNIFICANT FRONTAL SYSTEM WHICH WILL BRING MORE RAIN TO THE REGION SUNDAY MORNING. && .SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/... THE SREF SUGGEST RAIN SUNDAY MORNING LINGERING TO ABOUT MID DAY. THE LOCAL WRF SHOWS A SURGE OF SLIGHTLY WARMER AIR AHEAD OF THIS STRONG FRONTAL SYSTEM AND SHORT-WAVE. ANY WARM AIR WILL BE SHORT-LIVED. THE SIMULATED RADAR FROM THE WORKSTATION WRF SHOWS RAIN IN WESTERN AREAS FROM JOHNSTOWN TO WARREN AROUND 6 AM. THIS AREA OF RAIN BLOSSOMS AND SHOULD BE OVER CENTRAL AREAS BETWEEN 8 AND 10 AM. IT BECOMES FRAGMENTED AND SHOWERY AS THE AREA MOVES EASTWARD WITH ONLY SCATTERED SHOWERS AFTER ABOUT NOON SUNDAY. THE SREF AND LOCAL WRF SUGGEST 0.25 TO 0.75 INCHES OF RAIN FOR MOST AREAS. SOME ISOLATED AREAS OF 0.75 TO 1.00 INCHES ARE POSSIBLE. THOUGH THE RAIN SHOULD END AROUND NOON...IT WILL BE MOSTLY CLOUDY IN THE AFTERNOON. SHOWERS WILL DEVELOP IN THE COOLER AIR. THE BEST CHANCE OF SHOWERS WILL BE OVER THE HIGHER TERRAIN OF WESTERN AND NORTHERN PA. IT WILL BE AN UNSEASONABLY COLD AFTERNOON WITH TEMPERATURES MAINLY IN THE 40S AND 50S. SOME AREAS IN THE NW MIGHT NOT REACH 50 SUNDAY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE TEMPS CONTINUE TO GO DOWNHILL FOR MONDAY...AS -2 TO -4C 8H AIR MOVES IN TO THE NW HALF OF THE CWA...AND NUMS CLOSE TO ZERO REACH ALL THE WAY TO KMDT. THIS TRANSLATES TO MAXES ONLY IN THE UPPER 40S AND 50S. THAT WOULD BE 15 TO 20 DEGS BELOW NORMAL. NORTHWEST FLOW WILL HOLD FOR MANY DAYS AS THE UPPER LOW OVER EASTERN CANADA IS FORECAST TO REMAIN IN PLACE FOR MUCH OF THE LONG TERM PERIOD. THIS WILL CONTINUE THE UNSETTLED/SHOWERY PATTERN FOR AT LEAST THE FIRST HALF OF THIS COMING WEEK...WITH BELOW NORMAL TEMPS PROGGED INTO NEXT WEEKEND. AN UPPER RIDGE IS FCST TO BUILD OVER THE CENTRAL OR EASTERN U.S. LATER IN THE WEEK IN RESPONSE TO A BIG UPPER TROF DEVELOPING OVER THE ROCKIES. THIS COULD LEAD TO A MODERATING TREND BY NEXT WEEKEND...BUT THE DEEP CYCLONE OVER ERN CANADA AND NEW ENGLAND WILL HAVE SOMETHING TO SAY ABOUT HOW WARM IT GETS HERE. SEVERAL WEAK SHORTWAVES ARE FORECAST TO MOVE ALONG THE PA/NY BORDER SUNDAY NIGHT/MONDAY MORNING IN THE WAKE OF A MORE ORGANIZED WAVE SUNDAY MORNING. THIS WILL CONTINUE THE THREAT OF SCT SHOWERS INTO EARLY MONDAY. HPC AND GMOS MINIMUM TEMPS MONDAY MORNING ARE IN THE VICINITY OF FREEZING. THUS HAVE INTRODUCED THE POSSIBILITY OF SNOW SHOWERS MIXING WITH THE RAIN SHOWERS ACROSS THE NORTH CENTRAL MTNS FOR SEVERAL HOURS MONDAY MORNING THE 19TH OF MAY! CURRENT GUIDANCE IS GENERALLY SIMILAR IN ZIPPING ANOTHER SFC LOW THROUGH VA MON NIGHT/TUES. IT MAY BE FAR ENOUGH SOUTH TO KEEP ANY MENTION OF RAIN FROM THE REGION...BUT CHC POPS STILL LOOK GOOD - ESP FOR OUR SOUTHERN TIER. WED MAY BE DRY...BUT WILL HOLD THOSE POPS AT LOW CHCS...AND ALLOW NEWER HPC GUIDANCE TO HELP WITH THESE LATER PERIODS. MODELS HAVE TRENDED SLOWER AND FARTHER WEST WITH AXIS OF THE UPPER RIDGE FCST TO DEVELOP IN THE LATER HALF OF THE PD. WHICH MEANS THAT ANY WARM UP FOR THU INTO FRI WOULD BE LESS THAN EXPECTED AS OUR AIRMASS MODIFIES SLOWLY OR IT COULD JUST BE DELAYED A FEW DAYS. WHILE THE RIDGE POSITION MAY BE FARTHER WEST...IT APPEARS AS THOUGH ITS DEVELOPMENT MAY BE ENOUGH TO PUSH THE UPPER LOW AWAY FROM PA SUFFICIENTLY TO ALLOW A DECREASE IN THE SHOWERY WEATHER. REMOVED ANY MENTION OF SHOWERS AFTER THURSDAY NIGHT...BUT THEY MAY VERY WELL RETURN DEPENDING HOW THE EVOLVING UPPER PATTERN IS RESOLVED BY THE LONG TERM GUIDANCE. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... BREAK IN CLOUDS AND PRECIP PRIOR TO NEXT WAVE ARRIVING LATER THIS MORNING. IN WAKE OF SAT EVE PRECIP SHARP EROSION IN CLOUDS FROM A WEAKLY DIFFLUENT LOW/MID LVL ATMS COUPLED WITH DECOUPLED WINDS HAS RESULTED IN DECENT RADIATIONAL FOG DEVELOPMENT...AND IFR/LIFR FOR A FEW AIRFIELDS IN CENTRAL PA. EXPECT THIS TO PERSIST UNTIL 12Z WHEN BETTER MIXING WILL OCCUR. IR IMAGERY INDICATED LEADING EDGE OF CLOUDS ALREADY ENTERING EXTREME NW PA. RUC IS PROGGING PRECIP TO ARRIVE AT KBFD SHORTLY AFT SUNRISE WITH MVFR CONDS THRU MUCH OF THE DAY. SFC LOW WILL TRACK ALONG MASON-DIXON LINE THIS AFTN...WITH MVFR CONDS EXPECTED AT MOST AIRFIELDS IN CENTRAL PA UNTIL ARND 21-23Z WHEN PRECIP SHUD SLIDE EAST INTO THE SUSQ-VALLEY. AN ISO TSRA CANNOT BE RULED OUT FOR FAR SE PA THIS AFTN. UPR LVL LOW SLIDES ACROSS SW QUEBEC...PROVIDING A CHILLY/MOIST NW FLOW INTO THE MID- ATLANTI REGION LATE TONIGHT INTO MON MORNING. HIGHER TERRAIN AIRFIELDS IN NW PA EARLY MON COULD SEE LGT SHSN AS COLD AIR WRAPS IN BEHIND UPR LVL LOW. MON AFTN THRU EARLY TUE SHUD REMAIN QUIET AND DRY WITH VFR CONDS. A WEAK SFC LOW DIVES SE TOWARDS KY/TN TUE MORNING...MAY PRODUCE SOME CIRRUS ACROSS SW PA. WEAK SFC RIDGE TRIES TO POKE INTO SOUTHERN GRT LKS WED...BUT MAY STAY WEST OF MID-ATLANTIC REGION ENUF TO KEEP WEAK NW FLOW FOR CENTRAL PA INTO WED/THUR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM NEAR TERM...GRUMM SHORT TERM...GRUMM LONG TERM...GRUMM/GARTNER/EVANEGO AVIATION...BEACHLER pa AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 909 PM MDT SUN MAY 18 2008 .DISCUSSION...03Z SURFACE ANALYSIS HAD LOW OVER WESTERN ND WITH TROUGH TO CENTRAL NE. WELL-DEFINED SHORTWAVE OVER MT ACTIVATING UP TO 500J/KG MLCAPE PER LATEST RUC FORECAST. SUSPECT ACTIVITY WILL BE DIURNAL IN NATURE PRIMARILY...SO LOSS OF SOLAR INSOLATION WILL ALLOW ACTIVITY TO DYE AROUND 06Z. WIND GUST POTENTIAL BEHIND INITIAL BLAST WILL BECOME INCREASINGLY LIMITED AS BOUNDARY LAYER DECOUPLES. WILL TWEAK CURRENT FORECAST FOR THESE THOUGHTS. && .AVIATION...VFR CONDITIONS EXPECTED TONIGHT. ISOLATED -SHRA/-TSRA WILL AFFECT PORTIONS OF NORTHWEST SD UNTIL 06Z. && .PREV DISCUSSION... /ISSUED 656 PM MDT SUN MAY 18 2008/ DISCUSSION...00Z SURFACE ANALYSIS HAD LOW OVER WEST CENTRAL ND WITH TROUGH INTO WESTERN SD. CONVECTION FIRING AHEAD OF SHORTWAVE IN MT PER WATER VAPOUR LOOP...IN CONCERT WITH PEAK HEATING AND UP TO 500J/KG MLCAPE. WILL UP POPS IN NORTHWEST SD GIVEN REGIONAL RADAR LOOP. GUSTY WINDS MAIN CONCERN WITH STORMS. 46KTS AT K2WX AT 0031Z. AVIATION...VFR CONDITIONS EXPECTED TONIGHT. ISOLATED -TSRA MAY PASS THROUGH/NEAR KRAP THIS EVENING. PREV DISCUSSION... /ISSUED 207 PM MDT SUN MAY 18 2008/ DISCUSSION...CURRENT WATER VAPOR IMAGERY SHOWS SHORTWAVE OVER EASTERN MONTANA MOVING INTO NORTHEAST WYOMING. THUNDERSTORMS HAVE DEVELOPED OVER PORTIONS OF EAST CENTRAL MONTANA. EXPECT A FEW THUNDERSTORMS TO DEVELOP ACROSS PORTIONS OF NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA LATE THIS AFTERNOON INTO THIS EVENING. GIVEN RUC FORECAST SOUNDING CAPE VALUES AROUND 300 J/KG AND MARGINAL SHEAR OVER THE NORTHERN BLACK HILLS AND RAP...DO NOT EXPECT ANY OF THE STORMS TO BECOME SEVERE. IF ANY STORMS DEVELOP THEY SHOULD QUICKLY DIMINISH IN COVERAGE AFTER SUNSET. ANOTHER WEAK SHORTWAVE WILL MOVE OVER THE CWA TOMORROW BRINGING A SLIGHT CHANCE OF THUNDERSTORMS TO NORTHEAST WYOMING...THE BLACK HILLS...AND FAR WESTERN SOUTH DAKOTA. RIDGE OFF THE WEST COAST AND UPPER LOW OVER THE GREAT LAKES IS KEEPING NORTHWEST FLOW ACROSS THE CWA TONIGHT THROUGH TUESDAY. RIDGE WILL MOVE OVER THE ROCKIES ON TUESDAY AND INTO THE NORTHERN HIGH PLAINS TUESDAY NIGHT AS A TROUGH DIGS INTO THE PACIFIC NORTHWEST. SOUTHWEST FLOW ALOFT WILL SET UP OVER THE AREA TUESDAY NIGHT AS A SURFACE LOW DEVELOPS OVER EAST CENTRAL WYOMING. GOOD MOISTURE RETURN WILL BEGAN DEVELOPING TUESDAY NIGHT AHEAD OF THE DEVELOPING SYSTEM...BRINGING SOME GULF MOISTURE INTO THE NORTHERN HIGH PLAINS. EXTENDED...MODELS CONTINUE TO SHOW AN UPPER LEVEL TROUGH MOVING INTO THE PACIFIC NORTHWEST BY MIDWEEK...THEN CUTTING OFF ACROSS THE GREAT BASIN REGION LATE IN THE WEEK. THIS WILL SIGNIFICANTLY SLOW DOWN THE UPPER LEVEL PATTERN AS AN OMEGA HIGH SETS UP ACROSS THE MISSISSIPPI VALLEY LATE IN THE WORK WEEK. SOUTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE HIGH PLAINS REGION FOR MUCH OF THE EXTENDED PERIOD. NUMEROUS DISTURBANCES IN THIS FLOW SHOULD BRING OCCASIONAL CHANCES FOR SHOWERS AND STORMS. TIMING THESE DISTURBANCES IS NEAR IMPOSSIBLE AT THIS POINT...BUT MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT WITH THIS PATTERN SETTING UP...SO WILL KEEP THE DAILY CHANCES FOR PCPN IN THE FORECAST FROM WEDNESDAY THROUGH SUNDAY. TEMPERATURES WILL FLUCTUATE SOME OVER THE PERIOD...BUT GENERALLY REMAIN NEAR AVERAGE AFTER MAIN COLD FRONT PASSAGE ON WEDNESDAY. AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. AN ISOLATED SHOWER OR STORM IS POSSIBLE LATE THIS AFTERNOON AND EVENING...PRIMARILY ACROSS NORTHERN PARTS OF THE AREA. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ HELGESON sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 656 PM MDT SUN MAY 18 2008 .DISCUSSION...00Z SURFACE ANALYSIS HAD LOW OVER WEST CENTRAL ND WITH TROUGH INTO WESTERN SD. CONVECTION FIRING AHEAD OF SHORTWAVE IN MT PER WATER VAPOUR LOOP...IN CONCERT WITH PEAK HEATING AND UP TO 500J/KG MLCAPE. WILL UP POPS IN NORTHWEST SD GIVEN REGIONAL RADAR LOOP. GUSTY WINDS MAIN CONCERN WITH STORMS. 46KTS AT K2WX AT 0031Z. && .AVIATION...VFR CONDITIONS EXPECTED TONIGHT. ISOLATED -TSRA MAY PASS THROUGH/NEAR KRAP THIS EVENING. && .PREV DISCUSSION... /ISSUED 207 PM MDT SUN MAY 18 2008/ DISCUSSION...CURRENT WATER VAPOR IMAGERY SHOWS SHORTWAVE OVER EASTERN MONTANA MOVING INTO NORTHEAST WYOMING. THUNDERSTORMS HAVE DEVELOPED OVER PORTIONS OF EAST CENTRAL MONTANA. EXPECT A FEW THUNDERSTORMS TO DEVELOP ACROSS PORTIONS OF NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA LATE THIS AFTERNOON INTO THIS EVENING. GIVEN RUC FORECAST SOUNDING CAPE VALUES AROUND 300 J/KG AND MARGINAL SHEAR OVER THE NORTHERN BLACK HILLS AND RAP...DO NOT EXPECT ANY OF THE STORMS TO BECOME SEVERE. IF ANY STORMS DEVELOP THEY SHOULD QUICKLY DIMINISH IN COVERAGE AFTER SUNSET. ANOTHER WEAK SHORTWAVE WILL MOVE OVER THE CWA TOMORROW BRINGING A SLIGHT CHANCE OF THUNDERSTORMS TO NORTHEAST WYOMING...THE BLACK HILLS...AND FAR WESTERN SOUTH DAKOTA. RIDGE OFF THE WEST COAST AND UPPER LOW OVER THE GREAT LAKES IS KEEPING NORTHWEST FLOW ACROSS THE CWA TONIGHT THROUGH TUESDAY. RIDGE WILL MOVE OVER THE ROCKIES ON TUESDAY AND INTO THE NORTHERN HIGH PLAINS TUESDAY NIGHT AS A TROUGH DIGS INTO THE PACIFIC NORTHWEST. SOUTHWEST FLOW ALOFT WILL SET UP OVER THE AREA TUESDAY NIGHT AS A SURFACE LOW DEVELOPS OVER EAST CENTRAL WYOMING. GOOD MOISTURE RETURN WILL BEGAN DEVELOPING TUESDAY NIGHT AHEAD OF THE DEVELOPING SYSTEM...BRINGING SOME GULF MOISTURE INTO THE NORTHERN HIGH PLAINS. EXTENDED...MODELS CONTINUE TO SHOW AN UPPER LEVEL TROUGH MOVING INTO THE PACIFIC NORTHWEST BY MIDWEEK...THEN CUTTING OFF ACROSS THE GREAT BASIN REGION LATE IN THE WEEK. THIS WILL SIGNIFICANTLY SLOW DOWN THE UPPER LEVEL PATTERN AS AN OMEGA HIGH SETS UP ACROSS THE MISSISSIPPI VALLEY LATE IN THE WORK WEEK. SOUTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE HIGH PLAINS REGION FOR MUCH OF THE EXTENDED PERIOD. NUMEROUS DISTURBANCES IN THIS FLOW SHOULD BRING OCCASIONAL CHANCES FOR SHOWERS AND STORMS. TIMING THESE DISTURBANCES IS NEAR IMPOSSIBLE AT THIS POINT...BUT MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT WITH THIS PATTERN SETTING UP...SO WILL KEEP THE DAILY CHANCES FOR PCPN IN THE FORECAST FROM WEDNESDAY THROUGH SUNDAY. TEMPERATURES WILL FLUCTUATE SOME OVER THE PERIOD...BUT GENERALLY REMAIN NEAR AVERAGE AFTER MAIN COLD FRONT PASSAGE ON WEDNESDAY. AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. AN ISOLATED SHOWER OR STORM IS POSSIBLE LATE THIS AFTERNOON AND EVENING...PRIMARILY ACROSS NORTHERN PARTS OF THE AREA. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ HELGESON sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 207 PM MDT SUN MAY 18 2008 .DISCUSSION...CURRENT WATER VAPOR IMAGERY SHOWS SHORTWAVE OVER EASTERN MONTANA MOVING INTO NORTHEAST WYOMING. THUNDERSTORMS HAVE DEVELOPED OVER PORTIONS OF EAST CENTRAL MONTANA. EXPECT A FEW THUNDERSTORMS TO DEVELOP ACROSS PORTIONS OF NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA LATE THIS AFTERNOON INTO THIS EVENING. GIVEN RUC FORECAST SOUNDING CAPE VALUES AROUND 300 J/KG AND MARGINAL SHEAR OVER THE NORTHERN BLACK HILLS AND RAP...DO NOT EXPECT ANY OF THE STORMS TO BECOME SEVERE. IF ANY STORMS DEVELOP THEY SHOULD QUICKLY DIMINISH IN COVERAGE AFTER SUNSET. ANOTHER WEAK SHORTWAVE WILL MOVE OVER THE CWA TOMORROW BRINGING A SLIGHT CHANCE OF THUNDERSTORMS TO NORTHEAST WYOMING...THE BLACK HILLS...AND FAR WESTERN SOUTH DAKOTA. RIDGE OFF THE WEST COAST AND UPPER LOW OVER THE GREAT LAKES IS KEEPING NORTHWEST FLOW ACROSS THE CWA TONIGHT THROUGH TUESDAY. RIDGE WILL MOVE OVER THE ROCKIES ON TUESDAY AND INTO THE NORTHERN HIGH PLAINS TUESDAY NIGHT AS A TROUGH DIGS INTO THE PACIFIC NORTHWEST. SOUTHWEST FLOW ALOFT WILL SET UP OVER THE AREA TUESDAY NIGHT AS A SURFACE LOW DEVELOPS OVER EAST CENTRAL WYOMING. GOOD MOISTURE RETURN WILL BEGAN DEVELOPING TUESDAY NIGHT AHEAD OF THE DEVELOPING SYSTEM...BRINGING SOME GULF MOISTURE INTO THE NORTHERN HIGH PLAINS. EXTENDED...MODELS CONTINUE TO SHOW AN UPPER LEVEL TROUGH MOVING INTO THE PACIFIC NORTHWEST BY MIDWEEK...THEN CUTTING OFF ACROSS THE GREAT BASIN REGION LATE IN THE WEEK. THIS WILL SIGNIFICANTLY SLOW DOWN THE UPPER LEVEL PATTERN AS AN OMEGA HIGH SETS UP ACROSS THE MISSISSIPPI VALLEY LATE IN THE WORK WEEK. SOUTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE HIGH PLAINS REGION FOR MUCH OF THE EXTENDED PERIOD. NUMEROUS DISTURBANCES IN THIS FLOW SHOULD BRING OCCASIONAL CHANCES FOR SHOWERS AND STORMS. TIMING THESE DISTURBANCES IS NEAR IMPOSSIBLE AT THIS POINT...BUT MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT WITH THIS PATTERN SETTING UP...SO WILL KEEP THE DAILY CHANCES FOR PCPN IN THE FORECAST FROM WEDNESDAY THROUGH SUNDAY. TEMPERATURES WILL FLUCTUATE SOME OVER THE PERIOD...BUT GENERALLY REMAIN NEAR AVERAGE AFTER MAIN COLD FRONT PASSAGE ON WEDNESDAY. && .AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. AN ISOLATED SHOWER OR STORM IS POSSIBLE LATE THIS AFTERNOON AND EVENING...PRIMARILY ACROSS NORTHERN PARTS OF THE AREA. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 854 PM CDT MON MAY 19 2008 .UPDATE... FORECAST IS IN GOOD SHAPE AND WILL ONLY MAKE MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND SKY COVER. && .DISCUSSION... APPEARS MOST...IF NOT ALL...OF THE MIDSOUTH WILL REMAIN DRY TONIGHT AS A WEAK COLD FRONT MOVES THROUGH. MONITORING FOR POSSIBLE ISOLATED THUNDERSTORM DEVELOPMENT NORTH OF A JONESBORO AR TO JACKSON TN LINE. AT 845 PM CDT ACROSS THE MIDSOUTH...DRY CONDITIONS PREVAILED UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES. TEMPERATURES WERE MAINLY IN THE 70S. A SURFACE LOW WAS OVER THE SOUTHERN TIP OF ILLINOIS WHILE A WEAK COLD FRONT STRETCHED SOUTHWEST FROM THE LOW ACROSS SOUTHEAST MISSOURI INTO FAR NORTHWEST ARKANSAS. THE CLOSEST RAIN WAS OVER WESTERN KENTUCKY NEAR OWENSBORO. REST OF TONIGHT...ISOLATED THUNDERSTORM DEVELOPMENT NEAR THE APPROACHING WEAK COLD FRONT REMAINS THE BIGGEST QUESTION...BUT AT THIS TIME...NOT SURE IF ANYTHING WILL DEVELOP. LOCAL 00Z SOUNDINGS INDICATED WARM DRY AIR IN THE LOWEST 700 MB...ESPECIALLY LZK...THAT WOULD CAP SURFACE BASED CONVECTION. PERHAPS...ELEVATED CONVECTION...WITH PARCELS AT OR ABOVE 700 MB...COULD OCCUR ALONG THE FRONT AS IT APPROACHES...PARTICULARLY OVER NORTHWEST TENNESSEE WHERE LOWER/MID LEVEL TEMPERATURES BETWEEN 700 AND 850 MB WILL BE A BIT COOLER. THE LATEST LOCAL RUC MODEL SUGGEST AT THIS POSSIBLE DEVELOPMENT. IF ANY THUNDERSTORM DEVELOPS...AREAS NORTHWEST OF A UNION CITY TN TO LEXINGTON TN LINE WOULD HAVE THE BEST CHANCE OF BEING AFFECTED...BETWEEN 10 PM AND 3 AM CDT. SMALL HAIL AND GUSTY WINDS WOULD BE POSSIBLE. AT THIS TIME...THINK THUNDERSTORM DEVELOPMENT REMAINS UNLIKELY AND WILL NOT CHANGE MUCH FROM THE PREVIOUS FORECAST. FORECAST LOW TEMPERATURES MAY BE A BIT WARM...BUT DO NOT PLAN ON MESSING WITH THEM AT THIS TIME AS VARIABLE CLOUDS AND WINDS MAY KEEP THEM UP TONIGHT. UPDATE WILL BE OUT SHORTLY. && .PREV DISCUSSION... /ISSUED 328 PM CDT MON MAY 19 2008/ DISCUSSION... CURRENTLY...A 997 MB SURFACE LOW IS LOCATED OVER CENTRAL MISSOURI WITH WEAK HIGH PRESSURE ALONG THE GULF COAST. A STRONG PRESSURE GRADIENT ACROSS THE MID SOUTH IS PRODUCING GUSTY SOUTHWEST WINDS...ESPECIALLY ACROSS NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL WHERE WINDS ARE GUSTING OVER 40 MPH AT TIMES. SOME HIGH CLOUDINESS IS WORKING SOUTHWARD FROM THE MIDDLE MISSISSIPPI VALLEY INTO NORTHERN SECTION OF THE MID SOUTH OTRW SUNNY SKIES PREVAIL. TEMPS HAVE WARMED WELL INTO THE 80S ACROSS THE ENTIRE MID SOUTH. TONIGHT AND TUESDAY...LOW PRESSURE WILL TRACK ACROSS SOUTHEAST MISSOURI THIS EVENING AND ACROSS KENTUCKY LATER TONIGHT AND CLOUDINESS WILL INCREASE. A FEW SHOWERS OR THUNDERSTORMS MAY SNEAK INTO NORTHERN SECTIONS OF THE MID SOUTH OVERNIGHT THOUGH MOST PLACES WILL REMAIN DRY. A WEAK SURFACE TROUGH WILL PUSH SOUTH THROUGH THE REGION ON MONDAY AND WEAKEN. AREAS ALONG THE TENNESSEE/MISSISSIPPI BORDER SOUTHWARD MAY BECOME UNSTABLE ENOUGH FOR A FEW SHOWERS AND THUNDERSTORMS THOUGH LIFT AND MOISTURE ARE VERY MARGINAL AND AGAIN MOST PLACES WILL REMAIN DRY. CLOUDINESS WILL DECREASE THROUGHOUT THE DAY AND TEMPS WILL BE NOT QUITE AS WARM BUT STILL IN 80 TO 85 DEGREE RANGE. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...SURFACE TROUGH MOVES TO NEAR THE GULF COAST AND WEAK SURFACE HIGH PRESSURE WILL SETTLE OVER THE AREA WITH DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. THURSDAY THROUGH FRIDAY...SURFACE HIGH PRESSURE WILL SLIP EAST ON THURSDAY ALLOWING THE SURFACE BOUNDARY ALONG THE GULF COAST TO MOVE NORTH INTO THE MID SOUTH ALONG WITH SOME MOISTURE AND INSTABILITY. SHOWERS AND THUNDERSTORMS COULD DEVELOP ALONG THIS BOUNDARY THURSDAY AND THURSDAY NIGHT. BY FRIDAY A STRONG UPPER LEVEL RIDGE REALLY BEGINS TO DOMINATE THE PATTERN AND SURFACE HIGH PRESSURE OVER THE GREAT LAKES BEGINS TO SETTLE INTO THE OHIO AND TENNESSEE VALLEYS. THIS WILL HELP PUSH THE BOUNDARY AND THE MORE HUMID AIRMASS...ALONG WITH ANY RAIN CHANCES...TO THE SOUTH AND WEST OF THE REGION. SATURDAY AND SUNDAY...SHARP UPPER LEVEL RIDGE REMAINS ACROSS THE AREA WITH DRY SURFACE HIGH PRESSURE FEEDING IN FROM THE NORTHEAST. TEMPS WILL BE ABOVE NORMAL THOUGH HUMIDITY LEVELS WILL BE COMFORTABLE. && .PRELIMINARY POINT TEMPS/POPS... MEM 67 86 60 81 / 10 20 10 10 MKL 62 82 51 79 / 20 10 10 10 JBR 64 83 56 79 / 20 10 10 10 TUP 65 85 57 82 / 10 20 10 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$ MBS/SJM tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 751 PM CDT MON MAY 19 2008 .DISCUSSION... THE MODEL SHOWING THE BEST CHANCE FOR PRECIP OVERNIGHT IS CLEARLY THE NGM. A CLOSER LOOK HOWEVER...REVEALS THAT THE NGM 6 HR QPF ENDING AT 00Z IS USELESS. THUS...THAT MODEL CAN BE TOSSED. LATEST 18Z RUC IS PRECIP FREE OVERNIGHT AND THE 18Z MESO SHOWS ONLY LIMITED AMOUNTS ACROSS THE NORTH AND CUMBERLAND PLATEAU THROUGH 12Z. IT IS ALSO IMPORTANT TO NOTE THAT OVERALL...DEW POINTS ARE A FEW DEGREES LOWER THAN BOTH THE GRAPHIC AND NUMERIC PROGS. I AM THEREFORE GOING TO REDUCE POPS BY 20 PERCENT ACROSS THE BOARD. WE WILL STILL SEE A SLIGHT INCREASE IN MOISTURE THROUGH 12Z. ALSO...SOME UPPER DIVERGENCE WILL BE IN PLACE AROUND AND AFTER 06Z. THEREFORE...I WILL NOT TOTALLY REMOVE POPS AT THIS TIME. WILL CHANGE WORDING AND REMOVE AREAL COVERAGE DESCRIPTIONS IN TERMS OF WX. FOR THE REMAINDER OF THE FCST...TEMPS AND WINDS NEED NO CHANGING. 10 TO 15 MPH WIND SPEEDS ARE OK GIVEN THE APPROACHING COLD FRONT. UPDATE OUT SHORTLY. && .OHX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 21 tn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE AMARILLO TX 1157 PM CDT SAT MAY 17 2008 .AVIATION... VRB WINDS TNGT WILL BECOME WLY BY MRNG AS SFC TROF AXIS DVLPS ACRS HIGH PLAINS. GENLY MID TO HIGH CLOUDS ONLY. TROF DPNS SUN EVE WITH SWLY TO SLY WINDS EXPECTED THRU SUN NGT. KRAMAR && .PREV DISCUSSION... /ISSUED 926 PM CDT SAT MAY 17 2008/ UPDATE... ALL PRECIP HAS MOVED OUT OF FCST AREA AND HAVE REMOVED POPS FROM SWRN ZONES REST OF TONIGHT. UPDATED ZONES ALREADY SENT. ANDRADE PREV DISCUSSION... /ISSUED 643 PM CDT SAT MAY 17 2008/ AVIATION... GUSTY NLY WINDS WILL DECR AFTER SUNSET...WITH FORMING SFC TROF AXIS POSITION ACRS HIGH PLAINS TO AID IN DEVLPG WLY WINDS BY LATE TNGT. DECRG CLOUDS AS UPR TROF DEPARTS. KRAMAR PREV DISCUSSION... /ISSUED 330 PM CDT SAT MAY 17 2008/ DISCUSSION... MAIN FOCUS IN SHORT TERM IS CLOSED UPPER LOW CENTERED IN CENTRAL TX. HAVE SEEN WIDELY SCT TSRA DEVELOP THIS AFTERNOON LIKELY ASSOCIATED WITH S/WV DROPPING SOUTH AHEAD OF UPPER LOW. MAIN QUESTION FOR THIS EVENING WILL BE HOW LONG PRECIP HANGS AROUND THE PANHANDLES. SPC RUC MESOSCALE ANALYSIS INDICATES SOME INSTABILITY WITH SBCAPES AROUND 1000 J/KG AND MID LEVEL LAPSE RATES AROUND 7 DEG C/KM. WEAK LIFT IN ADVANCE OF UPPER LOW AND GIVEN THE ABOVE INSTABILITY PARAMETERS...WILL CONTINUE WITH MENTION OF ISOLD TSRA ACROSS THE FAR SOUTHWEST PORTION OF THE TX PANHANDLE THIS EVENING. EXPECT PRECIP TO DIMINISH SHORTLY AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING. OTHERWISE SKIES WILL GRADUALLY CLEAR LATER TONIGHT WITH LOW/MID LEVEL DRYING AND SATELLITE IMAGERY DOES INDICATE CLEARING FURTHER UPSTRAM IN KS. LOW TEMSP TONIGHT WILL MAINLY BE IN THE 50S EXCEPT UPPER 40S IN TYPICAL COOLER SPOTS. UPPER LOW WILL PUSH EAST OF THE CWA SUN AND WITH HIGHLY AMPLIFIED MID/UPPER RIDGE BUILDING OVER THE WRN CONUS...FLOW ALOFT REMAINS OUT OF THE NORTHWEST THE NEXT COUPLE OF DAYS. THIS SETUP WILL PROMOTE SIGNIFICANT DRYING ACROSS THE PANHANDLES AND COUPLED WITH SUBSIDENCE ASSOCIATED WITH RIDGE...PRECIP CHANCES WILL BE NIL THROUGH MUCH OF THE WEEK. TEMPS WILL WARM UP SIGNIFICANTLY ESPECIALLY MON WITH 850 HPA TEMPS CLIMBING TO NEAR 30 DEG C AND DOWNSLOPE FLOW. SURFACE TROUGH AND FAIRLY STRONG VORT MAX WILL DIVE SOUTHEAST INTO THE CENTRAL PLAINS MON AND WILL DRAG A WEAK COLD FRONT/WIND SHIFT LINE THROUGH THE AREA TUE. UPSLOPE FLOW WILL DEVELOP IN RESPONSE TO THIS WIND SHIFT WHICH WILL RESULT IN SLIGHTLY COOLER TEMPS TUE. THIS WILL BE SHORT LIVED HOWEVER AS TEMPS REBOUND BACK WELL INTO THE 90S WED. THE 12Z RUN OF THE GFS HAS COME MORE IN LINE WITH THE ECMWF IN THE EXTENDED AS LARGE TROUGH SET TO PUSH SOUTH OUT OF THE PACIFIC NORTHWEST AND DIGS INTO THE WESTERN CONUS. GIVEN THIS SYSTEM WILL REMAIN WELL WEST OF THE AREA AND CONTINUED SRLY FLOW AT THE SFC... RAISED TEMPS A LITTLE THU. GFS AND ECMWF START TO SUGGEST PRECIP CHANCES INCREASING NEXT WEEKEND BUT WILL CONTINUE WITH DRY FORECAST FOR NOW. CLK FIRE WEATHER... FIRE WEATHER CONCERNS WILL REMAIN MINIMAL FOR SOME TIME AS WINDS ARE EXPECTED TO BE LIGHT ALTHOUGH MID/UPPER LEVEL RIDGE WILL RESULT IN HOT TEMPS AND DRYING CONDITIONS ACROSS THE CWA. ELEVATED FIRE WEATHER CONDITIONS STILL LOOK POSSIBLE WED AS WIND SPEEDS INCREASE. CLK && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 828 PM CDT MON MAY 19 2008 .UPDATE...LATEST RADAR TRENDS INDICATED A DECREASE IN AREAL COVERAGE OF SHOWERS ACROSS THE FORECAST AREA THIS EVENING. THIS WAS IN ASSOCIATION WITH SUBSIDENCE BEGINNING TO WORK INTO THE AREA AS INDICATED BY LATEST RUC. ARXRUCWRF ALSO INDICATED DECREASING TREND IN SHOWERS SHOULD CONTINUE THIS EVENING AS UPPER LEVEL AND SURFACE WAVE EXIT FURTHER SOUTHEASTWARD. IN ADDITION PER LATEST RUC...STABLE ATMOSPHERE SHOULD PRECLUDE ANY THUNDER POTENTIAL. UPDATED DATA BASE WITH LATEST TRENDS AND ZONE FORECAST UPDATE WAS ISSUED AT 0120Z. THOMPSON && .PREV DISCUSSION... /ISSUED 345 PM CDT MON MAY 19 2008/ SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT RAIN CHANCES TONIGHT AND TUESDAY...AND FROST POTENTIAL ON TUESDAY NIGHT AND WEDNESDAY NIGHT ARE THE MAIN CONCERNS WITH PART OF THE FORECAST. AT 3 PM...A SHORT WAVE TROUGH WAS MOVE SOUTHEAST THROUGH CENTRAL MINNESOTA AND NORTHERN WISCONSIN. THIS SYSTEM WAS GENERATING AN AREA OF RAIN ACROSS NORTHEAST WISCONSIN AND CENTRAL MINNESOTA. THE 19.12Z MODELS CONTINUE TO SHOW THAT THIS SYSTEM WILL PRODUCE MODERATE TO STRONG 900 TO 700 MB FRONTOGENETIC FORCING AS IT MOVES ACROSS OUR AREA THIS EVENING. AS A RESULT...I RAISED THE PRECIPITATION PROBABILITIES INTO THE CATEGORICAL RANGE. RAINFALL TOTALS WILL LIKELY BE GENERALLY LESS THAN A TENTH OF AN INCH. ON TUESDAY...THE MODELS CONTINUE TO SHOW SOME INSTABILITY WILL DEVELOP ACROSS THE AREA DURING THE AFTERNOON. HOWEVER NEITHER THE 19.12Z GFS OR NAM/WRF SHOW ANY PRECIPITATION DEVELOPING. MEANWHILE SEVERAL OF THE MESOSCALE MODELS WERE GENERATING PRECIPITATION. HOWEVER THEY APPEAR TO HAVE TOO MUCH LOW LEVEL MOISTURE. AS A RESULT...I TRENDED WITH THE SURROUNDING WFOS TO GO DRY. WITH LIGHT WINDS AND MOSTLY CLEAR SKIES ON TUESDAY NIGHT AND WEDNESDAY NIGHT...WE SHOULD ONCE AGAIN SEE A GOOD NIGHTS OF RADIATIONAL COOLING. THIS COULD POTENTIALLY LEAD TO THE DEVELOPMENT OF FROST. THE GREATEST PROBABILITY OF THIS OCCURRING LOOKS TO BE IN NORTH CENTRAL AND CENTRAL WISCONSIN. LONG TERM...THURSDAY THROUGH MEMORIAL DAY STRONG TROPICAL FORCING ACROSS THE EASTERN ATLANTIC IS HELPING TO HOLD THE BLOCKING RIDGE ACROSS THE NORTH ATLANTIC IN PLACE. THIS ONLY MOVING A FEW DEGREES LONGITUDE A DAY. AS A RESULT...THE UPPER LEVEL LOW ACROSS THE NORTHEAST UNITED STATES AND EASTERN CANADA WILL LIKELY BE VERY SLUGGISH TO MOVE EAST. MEANWHILE THERE ARE TWO OTHER STRONG TROPICAL FORCING ACROSS BOTH THE EASTERN AND WESTERN EQUATORIAL PACIFIC. BOTH OF THESE WILL ALLOW THE DEVELOPMENT OF A HIGHLY AMPLIFIED RIDGE ACROSS THE EASTERN PACIFIC. IN ADDITION... THERE IS A MADDEN JULIAN OSCILLATION APPROACHING THE CENTRAL PACIFIC. THIS SYSTEM IS LIKELY AFFECTING THE WEATHER ACROSS THE UNITED STATES CURRENTLY. ALL OF THIS STRONG TROPICAL FORCING CONTINUES TO PLAY HAVOC ON OUR MEDIUM RANGE MODELS. THEY JUST WERE NOT DESIGNED TO HANDLE THIS. JUST LOOKING AT THE TROPICAL FORCING ALONE...WE SHOULD SEE DEVELOPMENT AN OMEGA BLOCK DEVELOP ACROSS THE UNITED STATES. OUR AREA SHOULD BE LOCATED IN THE RIDGE. THE MAIN QUESTION IS WHETHER WE WILL BE WEST OF THE RIDGE AXIS. IF THIS DOES OCCUR...WE WOULD SEE A MUCH MORE ACTIVE WEATHER PATTERN DEVELOP DURING THE LATTER HALF OF THE HOLIDAY WEEKEND. IF WE REMAIN OF THE EAST SIDE...WE WOULD STAY DRY. AT THIS TIME...IT REALLY IS UNCLEAR WHAT IS GOING TO TAKE PLACE. EVEN THOUGH I HAVE A DRY FORECAST THROUGH SUNDAY...I WOULD NOT BE TOO SURPRISED THAT WE MAY EVENTUALLY HAVE TO ADD PRECIPITATION PROBABILITIES TO MORE OF THE UPCOMING WEEKEND. WE WILL JUST HAVE TO MONITOR THINGS THROUGH THE WEEK. && AVIATION...TONIGHT AND TUESDAY CONVERGENCE AND LIFT WILL CONTINUE INCREASE ACROSS THE AREA LATE THIS AFTERNOON AND INTO THIS EVENING AS A SHORTWAVE IN THE NORTHWEST FLOW ALOFT DROPS ACROSS THE AREA. THE BULK OF THE FORCING...LIFT AND MOISTURE WILL BE ABOVE 850MB...WITH MOISTURE REMAINING LIMITED BELOW THIS LEVEL. THIS IS EXPECTED TO KEEP MVFR CIG/VSBY RESTRICTIONS TO A MINIMUM AS THIS SYSTEM PASSES. SCT -SHRA ARE STILL EXPECTED AS THE SYSTEM PASSES MAINLY IN THE 21Z-03Z TIME FRAME WITH VSBYS GENERALLY AT OR ABOVE P6SM AND CIGS AT OR ABOVE 5K FT. ISOLD TSRA STILL APPEAR POSSIBLE WITH THE LIFT AND SOME WEAK INSTABILITY ALOFT. SYSTEM PASSES SOUTHEAST OF THE TAF SITES LATE THIS EVENING...WITH GOOD VFR CONDITIONS EXPECTED AFTER 06Z THRU TUE MORNING IN SUBSIDENCE BEHIND THE SHORTWAVE. YET ANOTHER WEAK WAVE IN THE FLOW MAY SPREAD ISOLD -SHRA AND SOME BKN050 CIGS ACROSS THE AREA INTO TUE AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT AND LONG TERM - BOYNE AVIATION - RRS wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 319 AM EDT TUE MAY 20 2008 .SYNOPSIS... LOW PRESSURE, MOVING QUICKLY EAST FROM THE OHIO VALLEY, WILL BRING RAIN SHOWERS THIS MORNING INTO THE EVENING, BEFORE MOVING OFFSHORE. THE LOW WILL BE OVER THE NEW ENGLAND WATERS BUT A COOL NORTHWEST FLOW WILL MAINTAIN CLOUDS AND A COUPLE LIGHT SHOWERS FROM TIME TO TIME OVERNIGHT. A SECOND MUCH WEAKER SYSTEM WILL MOVE ACROSS THE REGION ON THURSDAY ACCOMPANIED BY LIGHT SHOWERS AND MAINTAINING A COOL TEMPERATURE REGIME. A RIDGE OF HIGH PRESSURE WILL BUILD DOWN ACROSS THE FORECAST AREA BEGINNING FRIDAY INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... STATUS QUO AS SHE GOES THIS MORNING. UPPER CYCLONE WILL PIVOT NORTHEAST NEAR JAMES BAY AND ALLOW A SHORT WAVE TO RAPIDLY SNEAK IN UNDER THE FLOW. THIS WILL TRIGGER A LOW PRESSURE OVER THE OHIO RIVER THIS MORNING AND PUSH IT RAPIDLY ALONG TO THE DELMARVA BY LATE AFTERNOON. SHOWERS WILL BE ON OUR DOORSTEP AROUND 8 AM AND CONTINUE INTO THE EVENING HOURS. NORTHERN PART OF CWA WILL SEE MUCH LESS PRECIPITATION(MAYBE .25)WHILE SRN AREAS WILL HAVE A QPF STRIP OF .75 TO 1.00 INCHES. THIS WOULD BE IN A BAND FROM OUR MARYLAND ZONES INTO CENTRAL DE AND SNJ BEFORE MOVING OFFSHORE. TEMPERATURES THIS MORNING IN NRN ZONES IN THE MID TO UPPER 30S AND THE 80H JET IS CLIPPING ALONG AT 45 TO 50 KTS JUST SOUTH OF THE LOW. MAY BE SOME SPOTTY CONVECTION WITH A NOSE OF 30 TO 32 K-VALUE AND POCKET OF -2 LI ACROSS MD/DE. FOR THIS REASON WILL INCLUDE A TSTM JUST SLIGHTLY SOUTH OF THE TRACK OF THE LOW FROM SRN MD ZONES- SNJ DE AND SNJ ZONES. AND...INCLUDE A GUSTY ONE AT THAT. IF WE DON`T REACH OUR HIGH IN PHL OF 60 IT`LL BE THE SECOND TIME THAT HAPPENED THIS MONTH. WE REACHED 51 ON MAY 12TH. NORTHERN AREAS WILL STRUGGLE TO GET OUT OF THE 40S! THE WINDS WILL BE LIGHT TODAY AND FULL CYCLE AS THE LOW TRACKS ACROSS US. MAX WINDS EXCEPT IN ANY THUNDERSTORMS WILL BE UNDER 10 KT. THIS SYSTEM HAS THE EAR-MARKS OF AN ALBERTA CLIPPER ABSENT THE SNOW. IT`LL MOVE FAST AND ZIP OFFSHORE BY DAYS END. CLOUD TOPS ARE COOLING TO THE -62C RANGE AND THIS IS INDICATIVE OF TSTMS. ONCE OFFSHORE TONIGHT...THE PRECIPITATION WILL TAPER OFF AND COLD AIR ADVECTION WILL KEEP INSTABILITY SHOWERS AROUND BUT WIDELY SCATTERED AND TEMPERATURES ON THE COOL SIDE WITH A +2C AT 80H IN THE CENTER OF THE CWA. LOWS TONIGHT WILL DROP TO THE MID 30S TO NEAR 50 AT THE SHORE. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... WHILE WE DO LOSE THE SURFACE FEATURE, THE UPPER AIR STILL CONTROLLED BY THE ROTATING CYCLONE JUST NORTH OF THE EASTERN GREAT LAKES. THE LOW DROPS SLIGHTLY SOUTH AND PULLS IN ANOTHER CORE OF COLDER TEMPERATURES AND ROTATE SOUTH AND INTO NORTHERN PENNSYLVANIA BY LATE WEDNESDAY. BY MORNING INSTABILITY SHOWERS WILL BE ON OUR DOORSTEP AGAIN. HIGH ON WEDNESDAY WILL RANGE FROM 53 TO 68 AND THAT CONTINUES TO BE ABOUT 8 DEGREES BELOW THE NORMAL. AND THE LOW WEDNESDAY NIGHT 33 TO 49. THE SHOWERS WILL MOVE EAST AND WE STILL REMAIN PTCLDY TO MCLDY. TEMPERATURES TO REMAIN BELOW NORMAL THROUGH THE SHORT TERM PERIOD. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... HIGHS FOR THURSDAY FROM THE LOWER 50S TO UPPER 60S. WE`RE STARTING TO SEE A BREAK IN THE STRANGLEHOLD OF THE UPPER LOW BY LATE FRIDAY. THE LOW TRACKS TO NOVA SCOTIA BUT HANGS A TROUGH BACK INTO PENNSYLVANIA FRIDAY AFTERNOON. THIS LAST ATTEMPT AT BRINGING SOME LIGHT SHOWERS TO THE REGION MAY JUST HAPPEN AS THE TROUGHINESS EXTENDS DOWN TO NJ BEFORE DEPARTING THE COAST FRIDAY EVENING. THE NORTHERLY WINDS ARE THE CULPRIT AS THEY TRY TO PULL A POCKET OF COOL AIR RIGHT DOWN THE BEACH BEFORE THE ENTIRE SYSTEMS PULLS EAST. FOR NOW I`M GOING TO MENTION A CHANCE OF SHOWERS FRIDAY AFTERNOON INTO THE EVENING. NOW...THE GOOD NEWS...WHAT LOOKS LIKE A VERY GOOD MEMORIAL DAY WEEKEND HOLIDAY IS SHAPING UP. A STRONG UPPER RIDGE FROM HUDSONS BAY INTO THE SOUTHEASTERN PLAINS STATES CLEARS THINGS OUT QUITE NICELY. THE RIDGE WILL BUILD EAST SLOWLY NUDGING THE LAST OF THE INFLUENCE FROM THE UPPER LOW AND THE AIR BEGINS TO DRY OUT BY SATURDAY MORNING INTO SUNDAY AND EVEN MONDAY. NOW...WE HAVE SEEN THE WEATHER FOR MEMORIAL DAY TURN IN A HURRY AND BECOME CLOUDY AND DRIZZLY, BUT THIS HIGH PRESSURE RIDGE LOOKS QUITE STRONG AND COVER THE ENTIRE FORECAST REGION. THE LAST TWO DAYS OF THE HOLIDAY WEEKEND COULD SEE TEMPERATURES IN THE UPPER 60S TO LOWER 70S IN THE POCONOS...LOW TO UPPER 70S IN NORTHWEST NEW JERSEY...AND 70S TO LOWER 80S IN OUR FAR SOUTHERN ZONES. WITH THAT...IT MAY BE OK TO GET THE BEER...SODA AND PRETZELS! && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... CURRENT SATELLITE IMAGERY SHOWS THE LEADING EDGE OF HIGH CLOUDS MOVING STEADILY ACROSS PA AND INTO NJ EARLY THIS MORNING. EXPECT CLOUDS TO THICKEN AND LOWER THROUGH THE MORNING HOURS AS AN AREA OF LOW PRESSURE APPROACHES THE REGION FROM THE OHIO VALLEY. THIS LOW IS EXPECTED TO MOVE SOUTH OF THE REGION AND OFF THE VA COAST. THERE ARE STILL SOME DISCREPANCIES IN THE MODELS, MAINLY WITH RESPECT TO THE NWD EXTENT OF THE PRECIP AND THE STARTING TIME. THE GFS IS FASTER (GENERALLY STARTING PRECIP BY 12Z OVER SRN AND WRN PORTIONS) AND SPREADS THE PRECIP FURTHER N DURING THE DAY. THE NAM/WRF IS SLOWER BRINGING THE PRECIP IN, AND DOESN`T BRING IT AS FAR N. THE RUC IS MUCH MORE SUPPORTIVE OF THE NAM/WRF WHILE THE ECMWF IS SOMEWHERE IN THE MIDDLE WITH TIMING, BUT SUPPORTS THE GFS WITH RESPECT TO THE FURTHER N EXTENT. CONDITIONS WILL START OFF VFR, BUT WILL DROP TO MVFR AFTER SUNRISE. AS THE STEADIER AND HEAVIER RAIN MOVES IN, IFR AND EVEN SOME LIFR CONDITIONS ARE POSSIBLE, ESPECIALLY FOR THE SOUTHERN TAF SITES. THE NAM IS ALSO FASTER ENDING THE PRECIP THAN THE GFS. BUT EVEN THE GFS SOLN HAS IMPROVING CONDITIONS THIS EVENING AS THE SHOWERS WOULD BECOME MORE SCATTERED, IF THEY LINGER IN THE FIRST PLACE. BY THE END OF THE TAF PERIOD, ALL MODELS INDICATE A RETURN TO VFR. OUTLOOK... A WEAK LOW WILL MOVE FROM NEAR THE GRTLKS TO NEW ENG ON WEDNESDAY AND ITS ASSOCD CDFNT WILL CROSS THE REGION WEDNESDAY AFTERNOON OR EVENING AND THIS MAY BRING A FEW SHOWERS, MAINLY TO NRN SECTIONS. HIGH PRESSURE WILL THAN TAKE OVER AND DOMINATE OUR WEATHER THROUGH THE WEEKEND. && .MARINE... WINDS AND SEAS HAVE DECREASED DURING THE OVERNIGHT HOURS. HOWEVER, AS THE AREA OF LOW PRESSURE MOVES EWD, WINDS AND SEAS WILL PICK UP LATER THIS AFTERNOON AND TONIGHT. ATTM, IT APPEARS THAT THE LOW WILL BE MOVING FAST ENOUGH THAT PROLONGED SCA CONDITIONS WILL NOT BE MET. HOWEVER, A BRIEF GUST TO 25 KT OR SEAS BRIEFLY REACHING 5 FT CAN NOT BE RULED OUT. LOW PRESSURE TO OUR NORTH WILL BRING A CDFNT THRU ON WEDNESDAY OR WEDNESDAY NIGHT. WHILE THIS FRONT MAY TRIGGER SOME SHOWERS, WINDS AND SEAS ARE EXPECTED TO REMAIN BLO SCA CRITERIA. HIGH PRESSURE WILL THEN BUILD IN FOR THE WEEKEND, BRINGING RATHER TRANQUIL CONDITIONS FOR THE AREA WATERS IN TIME FOR THE HOLIDAY WEEKEND. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...EBERWINE NEAR TERM...EBERWINE SHORT TERM...EBERWINE LONG TERM...EBERWINE AVIATION...NIERENBERG MARINE...NIERENBERG de AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 230 AM MDT TUE MAY 20 2008 .DISCUSSION...LOTS OF FORECAST CONCERNS OVER THE NEXT FEW DAYS INCLUDING THUNDERSTORM CHANCES/WINDS AND FIRE WEATHER. TODAY-WEDNESDAY...UPPER LEVEL LOW AND ASSOCIATED TROUGH WILL PUSH ASHORE ACROSS THE PACIFIC NORTHWEST TODAY DIGGING SOUTHEAST TOWARD THE INTERMOUNTAIN WEST BY 00Z THURSDAY. AS LEE TROUGH DEVELOPS LATE THIS AFTERNOON WINDS BECOME SOUTH/SOUTHEASTERLY AND GRADUALLY INCREASE IN SPEED AS THE PRESSURE GRADIENT BETWEEN THE APPROACHING SYSTEM TO OUR WEST AND SURFACE HIGH TO OUR EAST INCREASES. LOCAL WIND GUST PROGRAM AS WELL AS RUC AND MOS GUIDANCE WIND SPEEDS SUGGEST BREEZY CONDITIONS TONIGHT AND WINDY CONDITIONS WEDNESDAY. LOW LEVEL MOISTURE WILL INCREASE AS WELL. QUITE A DISPARITY BETWEEN 850 TEMPERATURES AND 2M/MOS GUIDANCE NUMBERS FOR HIGHS TODAY AND WEDNESDAY. MODIFIED 850 TEMPS WOULD SUGGEST MID/UPPER 80S TODAY AND LOW 90S WEDNESDAY...2M/MOS TEMPS SUGGEST 80 TODAY AND LOW 80S WEDNESDAY. WITH AN UNFAVORABLE WIND FOR STRONG WARMING AND AN INCREASE IN MID AND HIGH LEVEL CLOUDINESS I HAVE SPLIT THE TWO AND GONE WITH LOW TO MID 80S TODAY AND MID 80S TO AROUND 90 WEDNESDAY. GFS/NAM SHOW BETTER MID LEVEL MOISTURE AND SOME INSTABILITY ACROSS THE PALMER DIVIDE/CHEYENNE RIDGE/RATON RIDGE LATE THIS AFTERNOON WITH NAM PERHAPS GENERATING SOME LIGHT QPF ACROSS A FLAGLER TO YUMA LINE AND POINTS WEST. HAVE CONFINED SLIGHT CHANCE POPS TO THAT AREA LATE THIS AFTERNOON. ANY SHOWER/T-STORM THAT DEVELOPS SHOULD MOVE IN A GENERAL EAST DIRECTION TONIGHT...FEEDING INTO A DEVELOPING LOW LEVEL JET. GFS/NAM/RUC13 DO SHOW SOME MID LEVEL MOISTURE MOVING INTO THE EAST/SOUTHEAST PORTION OF THE AREA AFTER MIDNIGHT WITH SOME LIGHT QPF BEING GENERATED. CURRENT FORECAST SHOWS THIS WELL SO LITTLE ADJUSTMENT TO BE MADE. AFTER A BREAK IN THE PRECIP WEDNESDAY MORNING NAM/GFS SHOW A DISTURBANCE PER 700-500 MOISTURE MOVING INTO THE AREA FROM THE WEST/SOUTHWEST. CONVECTIVE INHIBITION SHOULD BE WEAK ALLOWING THUNDERSTORMS TO DEVELOP GENERALLY ACROSS THE WESTERN 1/3 OF THE AREA WITH A FOCUS POSSIBLY ACROSS KIT CARSON COUNTY WHERE NAM/GFS HAVE A SMALL 250 JET DIVERGENCE BULLSEYE. WEDNESDAY NIGHT-THURSDAY NIGHT...SURFACE LOW DEVELOPS IN SOUTHEAST COLORADO AS SYSTEM DIGS INTO THE UTAH AREA WITH MID LEVEL DRY SLOT PUSHING INTO THE AREA FROM THE SOUTH AFTER MIDNIGHT. THIS WILL MAKE IT RATHER DIFFICULT TO SUSTAIN ANY PRECIP THAT LINGERS FROM EARLIER EVENING CONVECTION. WILL MAINTAIN PREVIOUS POP FORECAST THROUGH MIDNIGHT THEN REMOVE IT. THERE WILL BE A RAPID INCREASE IN BOUNDARY LAYER MOISTURE AHEAD OF THE DRY SLOT AND SOME FOG/STRATUS IS POSSIBLE. WILL ADD IT ACCORDINGLY. DRYLINE PUSHES NORTH DURING THE DAY THURSDAY SHUNTING THE LOW LEVEL MOISTURE NORTH OF THE AREA BY LATE MORNING/EARLY AFTERNOON. THE VERY DRY AIR COMBINED WITH SOUTH TO SOUTHWEST WINDS OF 25 TO 35 MPH WITH HIGHER GUSTS WILL CREATE DANGEROUS FIRE WEATHER CONDITIONS ACROSS ALL BUT THE NORTHEAST TO EASTERN 1/3 TO 1/4 OF THE AREA. WILL ADDRESS THIS IN THE HWO AT PRESENT TIME BUT FIRE WEATHER WATCHES MAY BE NEEDED ONCE AGREEMENT ON TIMING AND JUST HOW LOW THE DEWPOINTS WILL BE DEVELOPS. THUNDERSTORMS WILL ALSO BE POSSIBLE WITH THE GREATEST CHANCE ACROSS THE EASTERN 1/3 OF THE AREA. ONLY CHANGE HERE WAS TO REMOVE PRECIP CHANCES ACROSS THE SOUTHWEST/WESTERN 1/3 OF THE AREA. WIND ADVISORIES MAY BE NEEDED AS WELL PER MOS GUIDANCE WINDS AND RUC 13 WINDS. UPPER LOW REMAINS ACROSS THE WEST THURSDAY NIGHT WITH A LOW OVER THE NORTHEAST AND RIDGE IN BETWEEN...MEANING LITTLE PROGRESS EXPECTED IN ANY UPPER LEVEL FEATURES. WITH VARIOUS DISTURBANCES MOVING INTO THE AREA THURSDAY NIGHT AND LOW LEVEL JET IN THE AREA CANT RULE OUT THUNDERSTORM CHANCES SO HAVE LEFT IT IN BUT FOCUSED BETTER CHANCES ACROSS THE EAST WHERE MOISTURE AVAILABILITY IS A LITTLE BETTER. DDT && .AVIATION... 12Z TAFS...VFR THROUGH THE 24 HOUR PERIOD. ONLY SOME MID AND HIGH LEVEL CLOUDINESS EXPECTED WITH ONLY ISOLATED -SHRA/-TSRA POSSIBLE TONIGHT AS A DISTURBANCE MOVES ACROSS THE AREA FROM THE WEST. LIGHT WINDS FOR MUCH OF THE PERIOD EXCEPT AT KGLD WHERE 15-20 KT SUSTAINED WINDS WITH HIGHER GUSTS EXPECTED SHORTLY AFTER DARK AS A LOW LEVEL JET DEVELOPS. DDT && .FIRE WEATHER... FIRE WEATHER HIGHLITES MAY NEEDED OVER PARTS OF FAR EASTERN COLORADO WEDNESDAY AFTERNOON AND EARLY EVENING AS RH VALUES FALL AT OR BELOW 20 PERCENT AND SOUTH TO SOUTHEAST WINDS GET INTO THE 20 TO 30 MPH RANGE. THE VERY DRY AND WINDY CONDITIONS WILL SPREAD EAST REACHING ALL BUT THE FAR NORTHEAST AND EAST THURSDAY AFTERNOON. HIGHLITES MAY AGAIN BE NEEDED. DDT && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ WFO GOODLAND ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 412 AM EDT TUE MAY 20 2008 .SYNOPSIS... A SLOW MOVING AND UNSEASONABLY STRONG UPPER LEVEL LOW PRESSURE AREA WILL KEEP COOL UNSETTLED WEATHER IN PLACE THROUGH MUCH OF THE WEEK. SOME MODERATION IN TEMPERATURES SHOULD BE SEEN BY THE HOLIDAY WEEKEND AS HIGH PRESSURE GRADUALLY NUDGES THE STORM SYSTEM OUT TO SEA AND AWAY FROM THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SFC LOW WAS ENTERING ERN KY AT THIS HOUR...WITH THE PRECIP SHIELD SO FAR SLIDING DUE EAST OUT OF THE OHIO VALLEY. ALL THE ENS GUIDANCE HAS VERY WET POPS TODAY BUT AM SOMEWHAT DISHEARTENED BY THE LACK OF PRECIP BEING OBSERVED UPSTREAM. I CHOSE A PATH BETWEEN THE VERY HI POPS IN THE GUIDANCE AND SOMETHING LOWER SUGGESTED BY THE LACK OF NORTHWARD PROGRESS TO THE RAIN SHIELD. HAVE TO PLACE A CERTAIN AMOUNT OF FAITH IN THE IDEA THAT THE PRECIP WILL FILL IN AROUND AND JUST AFTER SUNRISE AS WE SEE THE UPPER TROF AXIS ROTATE THRU AND THE BEST WARM ADVECTION TRACK ACROSS. HAVE TAPERED THINGS TO SCATTERED SHOWERS FOR THE MOST PART FOR THE SECOND PART OF THE DAY IN THE WAKE OF THE UPPER TROF. AT ANY RATE...SEEMS WE ARE LOOKING AT A HIGH PROBABILITY OF A LIGHT-MDT PRECIP EVENT WITH AMOUNTS UNDER .50" OVER MOST OF THE FCST AREA. THE HEAVIEST AMOUNTS WILL HUG THE MASON-DIXON LINE WITH AMOUNTS TAPERING OFF RAPIDLY TO THE NORTH. AN ANOMALOUS CHILL WILL ALSO BE FELT TODAY WITH HIGHS ANYWHERE FROM 15 TO 20 DEGREES BELOW NORMAL. WITH THE CHILL AND GUSTY WINDS YESTERDAY MORE REMINISCENT OF MARCH THAN LATE MAY...IT SEEMS KIND OF GROSS FOR THE TIME OF YEAR...IN THIS FORECASTER`S OPINION OF COURSE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... PERSISTENT CYCLONIC FLOW WILL NOT ALLOW FOR THE COMPLETE ELIMINATION OF THE MENTION OF SHOWERS FOR THE OVERNIGHT. SEEMS THE BEST CHANCES WILL BE OVER THE WESTERN AND NORTHERN HIGH TERRAIN...VERY MUCH AS WE ARE ACCUSTOMED TO SEEING WITH A COLD SEASON CYCLONE. OVERNIGHT LOWS WILL DROP INTO THE 30S OVER THE FAR NORTH AND PREV SHIFTS WORKED A MIX OF WET SNOW INTO THE FORECAST FOR A FEW HOURS LATE TONIGHT. FORECAST SOUNDINGS DO NOT QUITE SUPPORT THE SNOW AND I JUST CANNOT BRING MYSELF TO MENTION THE WORD IN A FORECAST THIS LATE IN THE YEAR WITH VERY GOOD CAUSE. SOME CHILLY SHOWERS IS BAD ENOUGH I SUPPOSE AS PEOPLE START TO THINK MORE ABOUT PLANTING GARDENS THAN SEEING WINTRY PRECIP THIS LATE IN THE YEAR. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... ANOMALOUS UPPER TROUGH...2-4 STD DEV BELOW NORMAL...WILL CONTINUE TO SPIN OVERHEAD THROUGH LATE WEEK...BEFORE FINALLY SLIDING OFF THE NERN COAST. WITH A SEEMING NEVER ENDING SUPPLY OF WEAK UPPER IMPULSES UNTIL THE LOW MOVES EAST...WE KEEP THE MENTION OF PRECIP IN THE FORECAST FOR MUCH OF THE WEEK ALONG WITH ANOMALOUSLY CHILLY TEMPS. THE PROMISE OF A RETURN TO NORMALCY IS SEEN IN THE EXTENDED AS THE GEFS SHUNTS THE LOW EAST AND PUSHES A HUGE RIDGE THRU THE GR LAKES AND EVENTUALLY THE NERN US. THE ECMWF SHOWS A SIMILAR SCENARIO...ALTHOUGH PERHAPS ONLY TEMPORARY AS IT WANTS TO REESTABLISH A TROF OVER SERN CANADA AND NERN US BY MID NEXT WEEK. FAR ENUF AWAY TO NOT WORRY TOO MUCH ABOUT AT THIS POINT...BUT STILL I`D LIKE TO SEE A PATTERN THAT LOOKS MORE LIKE LATE MAY THAN MARCH && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... VFR CONDS AT ALL AIRFIELDS IN CENTRAL PA THRU 10Z. RUC ANALYSIS INDICATED SFC LOW NEAR CENTRAL KY...EXPECTED TO SLIDE NE INTO NORTH CENTRAL VA BY THIS AFTN. HIGH LVL MOISTURE NOT ASSOCIATED WITH SFC FEATURE WAS PUSHING SCT/BKN DECK AT 10KFT INTO WESTERN PA AT 06Z. RADAR RETURNS INCREASING ACROSS SOUTH CENTRAL OHIO SLIDING EAST. EXPECT CONDS TO DETERIORATE SHORTLY AFT 10Z WITH VFR TEMPO MVFR CIGS AT KBFD/KIPT...WITH STEADIER SHOWERS FURTHER SOUTH RESULTING IN IFR CIGS FOR REMAINING TAF SITES. SFC LOW WILL QUICKLY SWING NE THRU DELMARVA BY TUE EVE...PULLING LOW/MID LVL MOISTURE WITH IT. SOME RESIDUAL LOW CIGS AT KJST/KAOO/KMDT/KIPT...WILL GRADUALLY RETURN TO VFR BY SUNRISE WED. UPPER LVL LOW OVER QUEBEC WILL SLIDE SE INTO NEW ENGLAND BY THUR/FRI...SENDING A SERIES OF WEAK IMPULSES ACROSS OHIO RVR VALLEY AND MID-ATLANTIC STATES. MOISTURE FROM THESE WAVES APPEARS TO BE LACKING...HOWEVER CONFIDENCE IS LOW. EXPECT THOUGH THAT VFR WILL PERSIST WED/THUR/FRI WITH JUST SCT -SHRA ALONG THE FAVORED UPSLOPE AIRFIELDS OF KBFD/KJST. THIS MAY BE ENUF TO PRODUCE TEMPO MVFR CONDS AT THESE SITES AS WELL EACH DAY. CENTRAL PLAINS HIGH PRESSURE IS PROGGED TO SLOWLY SLIDE EAST FRI/SAT...PUSHING THE UPPER LVL LOW OVER NEW ENGLAND EAST TOWARDS ATLANTIC. THAT SHOULD PROVIDE MINIMAL CLOUDS AND SOLID VFR SAT. && .CTP WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ041-042. && $$ SYNOPSIS...LACORTE NEAR TERM...LACORTE SHORT TERM...LACORTE LONG TERM...LACORTE AVIATION...BEACHLER pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 156 AM EDT TUE MAY 20 2008 .SYNOPSIS... A DEEP UPPER LEVEL LOW OVER SOUTHEASTERN CANADA AND THE NORTHEAST U.S. WILL KEEP IT COOL AND UNSETTLED THROUGH MID WEEK. AFTER A CHILLY NIGHT TONIGHT...A STRONG UPPER DISTURBANCE WILL HEAD SOUTHEAST...REACHING THE UPPER OHIO RIVER VALLEY BY DAYBREAK. THIS WEATHER FEATURE WILL SPREAD CLOUDS AND PERIODS OF RAIN ACROSS MAINLY CENTRAL AND SOUTHERN PENNSYLVANIA INTO TUESDAY AFTERNOON. MORE INTERMITTENT LIGHT RAIN OR SHOWERS WILL OCCUR TO THE NORTH OF INTERSTATE 80. COLDER THAN NORMAL TEMPERATURES AND SCATTERED SHOWERS WILL LINGER WEDNESDAY...WITH SOME WET SNOW FLAKES POSSIBLY MIXED IN ACROSS THE NORTHERN MOUNTAINS WEDNESDAY MORNING. TEMPERATURES MAY MODERATE DURING THE LATTER HALF OF THE WEEK...BUT THE UPPER LEVEL LOW WILL BE TOUGH TO DISPLACE. && .NEAR TERM /THROUGH TODAY/... SCT-BKN STRATO CU CLOUD DECK WILL CONTINUE TO DIMINISH AND MOVE OFF TO THE EAST OF THE CWA...WITH THE COLDEST 925-850 HPA AIR. CLEAR TO PARTLY CLOUDY SKIES WILL OCCUR THROUGH THE FIRST HALF OF TONIGHT FOR ALL AREAS EXCEPT THE SW QUARTER OF THE STATE WHERE BKN ALTO CU WILL OCCUR. WESTERLY WINDS OF 10 TO 15 KTS AND GUSTY THIS EVENING WILL SLACKEN TO AROUND 5 KTS AS THEY BACK TO THE SOUTH/SW...AND EVEN BECOME LIGHT AND VARIABLE LATE TONIGHT ACROSS THE NRN MTNS. TEMPS WILL DIPPING INTO THE 30S OVER THE NORTHERN THIRD OF MY FORECAST AREA. SULLIVAN AND NORTHERN LYCOMING COUNTIES WILL BE SUSCEPTIBLE TO FROST AND SINCE THEIR GROWING SEASON HAS JUST OFFICIALLY BEGUN...HAVE ISSUED A FROST ADVISORY FROM 10 PM TONIGHT THROUGH 9AM TUE. A POTENT UPPER SHORTWAVE AND ASSOCIATED 120 KT JET AT 250 HPA WILL DIVE SE FROM THE UPPER MIDWEST OVERNIGHT AND LINK UP WITH THE THERMALLY DIRECT RIGHT ENTRANCE REGION OF A SLOWLY LIFTING EAST/WEST JET MAX FROM NEPA TO THE SRN NEW ENGLAND COAST. CLOUDS WILL THICKEN UP FROM THE SOUTHWEST DURING THE EARLY TO MID MORNING HOURS TUESDAY WITH A SHIELD OF RAIN SLOWLY EDGING TO THE NE ACROSS THE CWA. 15Z SREF AND 18Z OPERATIONAL NAM AND GFS MODELS SHOW A VERY HIGH PROBABILITY FOR RAIN ACROSS THE SOUTHERN HALF OF THE STATE...TO MAINLY HIGH 60-70 POPS FOR "LIGHT" RAIN JUST TO THE NORTH OF INTERSTATE 80. STRONGEST ISENTROPIC LIFT WITHIN THE 290-300K THETA LAYER ASSOCIATED WITH THE NOSE OF A SWRLY 40-45 JET WILL OCCUR BETWEEN 11-16Z (ACROSS THE CENTRAL AND SW ZONES)...AND A FEW HRS LATER ACROSS THE CENTRAL AND LOWER SUSQ VALLEY. STORM TOTAL QPF BY TUESDAY EVENING WILL RANGE FROM SEVERAL HUNDREDTHS NEAR AND TO THE NORTH OF ROUTE 6 IN NRN PENN...TO AROUND 0.25" JUST SOUTH OF INTERSTATE 80. AROUND 0.50" OF RAINFALL IS POSSIBLE ALONG PA/MD BORDER. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... POPS WILL DECREASE TO 20-30 PERCENT ACROSS THE WRN MTNS AND LAUREL HIGHLANDS FOR MUCH OF TUESDAY NIGHT (AND LESS THAN 20 PERCENT ACROSS THE CENTRAL AND SE ZONES) AS ANOTHER COLD SURGE DROPS SOUTHEASTWARD FROM THE CENTRAL GLAKS FOR LATER TUESDAY NIGHT INTO WEDNESDAY. SCATTERED SHOWERS WILL OVERSPREAD MUCH OF THE REGION TWD DAYBREAK WEDNESDAY...AND THE AIR JUST A FEW KFT AGL WILL BECOME COLD ENOUGH AGAIN TO SUPPORT A MIX WITH WET SNOW SHOWERS ACROSS THE NRN MTNS UNTIL AROUND 14-15Z WED. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... ANOMOLOUS UPPER TROUGH /2SD BELOW NORMAL/ WILL CONTINUE TO SPIN OVERHEAD THROUGH LATE WEEK...WEAKENING A LITTLE TUE BUT RE-ESTABLISHING ITSELF BY MIDWEEK AS SECOND WAVE ROTATES THROUGH. BLOCKING RIDGE IN THE MIDDLE U.S. WILL REINFORCE THE LOW OVER THE NORTHEAST. THE RIDGE WILL GAIN A BIT OF NEGATIVE TILT AT MIDWEEK BEFORE FINALLY BROADENING AND MOVING TOWARD THE EAST COAST FOR THE WEEKEND. AT THE SURFACE...A WEAK LOW PRESSURE AREA SLIDES THROUGH SOUTHERN PORTIONS MON INTO WED BEFORE HIGH PRESSURE BUILDS IN FROM THE NW. THIS WILL RESULT IN COOLER WEATHER THROUGH THE WORKWEEK BUT THEN AN IMPROVEMENT TO SOME AT OR SLIGHTLY ABOVE NORMAL TEMPS FOR THE WEEKEND. SHOWERS WILL LINGER WED THANKS TO COLD AIR/INSTABILITY ALOFT...BUT THEN A DRY WEEKEND IN STORE. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... VFR CONDS AT ALL AIRFIELDS IN CENTRAL PA THRU 10Z. RUC ANALYSIS INDICATED SFC LOW NEAR CENTRAL KY...EXPECTED TO SLIDE NE INTO NORTH CENTRAL VA BY THIS AFTN. HIGH LVL MOISTURE NOT ASSOCIATED WITH SFC FEATURE WAS PUSHING SCT/BKN DECK AT 10KFT INTO WESTERN PA AT 06Z. RADAR RETURNS INCREASING ACROSS SOUTH CENTRAL OHIO SLIDING EAST. EXPECT CONDS TO DETERIORATE SHORTLY AFT 10Z WITH VFR TEMPO MVFR CIGS AT KBFD/KIPT...WITH STEADIER SHOWERS FURTHER SOUTH RESULTING IN IFR CIGS FOR REMAINING TAF SITES. SFC LOW WILL QUICKLY SWING NE THRU DELMARVA BY TUE EVE...PULLING LOW/MID LVL MOISTURE WITH IT. SOME RESIDUAL LOW CIGS AT KJST/KAOO/KMDT/KIPT...WILL GRADUALLY RETURN TO VFR BY SUNRISE WED. UPPER LVL LOW OVER QUEBEC WILL SLIDE SE INTO NEW ENGLAND BY THUR/FRI...SENDING A SERIES OF WEAK IMPULSES ACROSS OHIO RVR VALLEY AND MID-ATLANTIC STATES. MOISTURE FROM THESE WAVES APPEARS TO BE LACKING...HOWEVER CONFIDENCE IS LOW. EXPECT THOUGH THAT VFR WILL PERSIST WED/THUR/FRI WITH JUST SCT -SHRA ALONG THE FAVORED UPSLOPE AIRFIELDS OF KBFD/KJST. THIS MAY BE ENUF TO PRODUCE TEMPO MVFR CONDS AT THESE SITES AS WELL EACH DAY. CENTRAL PLAINS HIGH PRESSURE IS PROGGED TO SLOWLY SLIDE EAST FRI/SAT...PUSHING THE UPPER LVL LOW OVER NEW ENGLAND EAST TOWARDS ATLANTIC. THAT SHOULD PROVIDE MINIMAL CLOUDS AND SOLID VFR SAT. && .CTP WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ041-042. && $$ SYNOPSIS...LAMBERT/RXR NEAR TERM...DEVOIR/LAMBERT SHORT TERM...DEVOIR/LAMBERT LONG TERM...RXR AVIATION...BEACHLER pa AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 525 AM CDT TUE MAY 20 2008 .UPDATE... 9Z RUC 850-1000MB THICKNESS FORECAST FOR THIS AFTERNOON ACROSS THE SW SUGGEST PREVIOUS HIGH TEMP FORECAST FOR TODAY WAS TOO COOL. HAVE BUMPED UP HIGHS 2-3 DEGREES IN THE SW ZONES. && .PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAY 20 2008/ DISCUSSION... A VERY WEAK COLD FRONT IS CURRENTLY BECOMING BETTER DEFINED ACROSS NW TEXAS ON THE BACK SIDE OF YESTERDAY/S REMNANT THERMAL CYCLONE NOW LOCATED SW OF WICHITA FALLS. SOUTHWARD FRONTAL MOVEMENT WILL BE AUGMENTED BY VEERING MID LEVEL FLOW IN RESPONSE TO A WEAK SHORTWAVE MOVING INTO THE LOWER MISSISSIPPI VALLEY. THE AXIS OF WARMEST LOW LEVEL THICKNESS VALUES WILL BE SHUNTED SOUTHWARD FROM THE NW ZONES INTO THE SW ZONES DURING THE DAY. THEREFORE...HIGHS WILL BE A FEW DEGREES COOLER OVER THE NORTHERN CWA...BUT A COUPLE DEGREES WARMER OVER THE SOUTH AHEAD OF THE FRONT. WACO SHOULD BREAK THEIR RECORD HIGH OF 95 LAST SET IN 1996. AN ISOLATED SHOWER OR STORM ALONG THE FRONT WILL BE POSSIBLE THIS AFTERNOON WHEN CIN MAY BECOME NEGLIGIBLE. THE LACK OF UPPER LEVEL LIFTING SUPPORT WARRANTS NO INCLUSION OF POPS IN THE WORDED FORECAST ATTM. THE FRONT WILL GRADUALLY MOVE THROUGH THE SOUTHERN CWA THIS EVENING BEFORE WASHING OUT. EAST TO NORTHEAST WINDS WILL BRING IN SLIGHTLY COOLER AIR TO THE REGION AND THEREFORE WEDNESDAY HIGH TEMPS WILL BE A LITTLE COOLER. A DEVELOPING LARGE AND DEEP UPPER LEVEL TROUGH OVER THE WESTERN CONUS WILL CAUSE SOUTHERLY WINDS TO INCREASE LATE WEDNESDAY AND INTO THE WEEKEND. WARMER OVERNIGHT LOW TEMPERATURES AND LATE NIGHT/MORNING STRATUS WILL BE THE RESULT. HIGH TEMPERATURES SHOULD REMAIN GENERALLY IN THE LOWER 90S WITH LOWS IN THE LOW TO MID 70S THROUGH EARLY NEXT WEEK. THE CHANCES OF RAIN LOOK RATHER LOW AS THE WESTERN SYSTEM FAILS TO ADVANCE EASTWARD. UPPER LEVEL RIDGING WILL BUILD IN ACROSS THE MIDWEST AND EVENTUALLY SLIDE SOUTHWEST TO ENCOMPASS THE REGION NEXT WEEK. ALTHOUGH MOISTURE/INSTABILITY WILL BE IN PLACE FOR CONVECTION...CIN WILL BE TOUGH TO OVERCOME IN THE ABSENCE OF UPPER LEVEL LIFT. THURSDAY AND FRIDAY MAY BE THE BEST SHOT AT ISOLATED AFTERNOON OR EVENING SHOWERS AND STORMS. WILL KEEP POPS AT 20 PERCENT THURSDAY THROUGH SATURDAY BEFORE HEIGHT RISES ASSOCIATED WITH THE BUILDING UPPER LEVEL HIGH PROMOTE SUBSIDENCE THEREAFTER. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 66 92 74 92 / 10 10 5 5 20 WACO, TX 99 67 92 73 92 / 5 5 10 10 20 PARIS, TX 89 59 87 68 89 / 10 10 5 5 20 DENTON, TX 93 62 91 73 92 / 10 5 5 5 20 MCKINNEY, TX 91 61 90 72 90 / 10 10 5 5 20 DALLAS, TX 94 67 92 74 92 / 10 10 5 5 20 TERRELL, TX 92 62 90 72 91 / 10 10 5 5 20 CORSICANA, TX 94 64 91 72 91 / 10 10 10 10 20 TEMPLE, TX 97 68 92 72 92 / 5 5 10 10 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/99 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 1009 AM EDT TUE MAY 20 2008 .DISCUSSION...LATEST SURFACE ANALYSIS SHOWS A COLD FRONT NEAR THE KENTUCKY AND TENNESSEE STATE-LINE WITH TEMPERATURES IN THE 70S ACROSS THE FORECAST AREA DROPPING INTO THE 50S IN KENTUCKY. RUC MODEL SHOWS THIS BOUNDARY MOVING SLOWLY SOUTH ACROSS THE FORECAST AREA TODAY. LAPS DATA SHOWS AIR-MASS DESTABILIZING OVER THE REGION WITH CAPES APPROACHING 1000 J/KG. RUC SOUNDINGS SHOW THE FORECAST AREA BECOMING FAIRLY UNSTABLE WITH CAPES BETWEEN 1500-2000 J/KG AND LIFTED INDICES OF -4 TO -6...ESPECIALLY OVER THE SOUTHERN HALF OF THE TENNESSEE VALEY. I EXPECT SCATTERED THUNDERSTORMS TO REDEVELOP ALONG AND AHEAD OF THIS BOUNDARY TODAY AS ANOTHER WEAK SHORT-WAVE MOVES SOUTHEAST OF THE APPALACHIANS THIS AFTERNOON. THERE IS A CONCERN THAT SOME OF THESE STORMS COULD BECOME SEVERE GIVEN WET-BULB HEIGHTS OF 10500 FT AND MODERATELY STRONG BOUNDARY LAYER WINDS. ALSO...SOME MID-LEVEL DRY AIR WILL AID WITH DOWNBURST POTENTIAL. WILL UPGRADE HWO WITH THE POTENTIAL OF SEVERE WEATHER FOR AREAS GENERALLY ALONG AND SOUTH OF INTERESTATE 40. TEMPERATURE FORECAST LOOKS GOOD. && .SHORT TERM...(TODAY AND TONIGHT)...WARM AIR ADVECTION FROM 850 TO 700 MB LEVELS IS GENERATING SOME ELEVATED INSTABILITY OVER THE OHIO VALLEY INTO THE CENTRAL/SRN APPALACHIANS AT THIS TIME. THUS... ONGOING CONVECTION IS HOLDING TOGETHER AND MOVING EAST ACROSS MOST OF SWRN VA AND PARTS OF NE TN...WITH A FEW LIGHTNING STRIKES NOTED. ADJUSTED POP AND WEATHER GRIDS EARLY THIS MORNING TO REFLECT THIS CONVECTION...THEN GENERALLY LOWERED POPS ALL AREAS FOR MID MORNING ...AND THEN TRENDED CLOSE TO PREVIOUS POPS THIS AFTERNOON FOR NEW DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. THINKING THAT COVERAGE MAY STAY SCATTERED OR SO...BUT KEPT A SMALL POCKET OF LIKELY POPS FOR CONTINUITY WITH PREVIOUS GRIDS. GFS MOS MAX TEMPS RECOVERED YESTERDAY AND PERFORMED QUITE WELL. CURRENT TEMPS WERE RUNNING VERY MILD WHERE GOOD MIXING WAS NOTED...SO OPTED TO GO CLOSE TO OR JUST ABOVE THE GFS MAXES FOR TODAY. THE OTHER ITEM OF CONCERN FOR TODAY IS THE LAKE WIND AND WIND ADVISORIES IN EFFECT THROUGH 4 PM EDT. LOW LEVEL JET IS STRONGEST THIS MORNING...WITH AREA OBSERVATIONS (ESPECIALLY ELEVATIONS ABOVE 2500 FEET) SHOWING STRONG SUSTAINED SPEEDS AND HIGHER GUSTS EASILY IN AVDISORY RANGE. I EXPECT THE STRONGER SPEEDS AND GUSTS TO OCCUR THROUGH 16Z TO 18Z TODAY...THEN SHOULD SEE A DECREASE IN WINDS EXCEPT WHERE ANY CONVECTION OCCURS. I WILL LET THE LAKE WIND AND WIND ADVISORIES RUN THROUGH 4PM EDT...BUT DAY SHIFT SHOULD BE ABLE TO END THESE ADVISORIES A LITTLE BEFORE AFTERNOON PACKAGE IS ISSUED. FOR TONIGHT...MAY SEE LINGERING SHOWERS BEFORE A GRADUAL CLEARING AND THIS IS GENERALLY WHAT CURRENT GRIDS INDICATED. THUS...LITTLE CHANGES MADE FOR TONIGHT WITH A MOS BLEND GOOD FOR MINS. .LONG TERM...(WEDNESDAY THROUGH MONDAY)...THIS PERIOD STARTS WITH GREAT LAKES CYCLONE STILL HAVING EFFECTS...WITH NORTHWEST FLOW OVER AREA. WILL INTRODUCE SOME LIGHT POPS FOR WEDNESDAY FOR NORTHEAST PART OF CWA DUE TO MOIST AIR MASS AND BUSY UPPER LEVEL FLOW OVER THAT PART OF THE AREA...THINK THAT LITTLE IMPULSES PLUS DIURNAL HEATING COULD GET SOME SHOWERS GOING. FOR THURSDAY ALSO HAVE POPS SPREADING IN FROM SOUTHWEST AS STABLE LIFT OF MOIST AIR RIDES UP ISENTROPIC SURFACE. THINK ALL PRECIP THURSDAY WILL BE RAIN. BY FRIDAY...MOIST AIR ALOFT IS RICH ENOUGH TO INDUCE SOME ELEVATED AND POSSIBLY SURFACE INSTABILITY...SO HAVE ISOLATED STORMS MENTIONED WHERE FOR MUCH OF AREA. NORTHEAST AREAS LOOK TO HAVE LESS POPS THURSDAY THROUGH FRIDAY...BUT WILL NEED TO KEEP CLOSE WATCH ON FRIDAY AS FRONTAL PASSAGE LOOKS PRETTY VIGOROUS...JUST LACKING TOO MUCH MOISTURE TO INCLUDE POPS THERE FOR NOW. GOOD DRY PUSH OF SURFACE AIR AS FRONT MOVE THROUGH FRIDAY NIGHT/SATURDAY MORNING...AND UPPER RIDGE BUILDS IN FROM WEST. SHOULD WARM UP NICELY SATURDAY AND ESPECIALLY SUNDAY. FOR TEMPS WENT CLOSE TO GUIDANCE...WITH A LITTLE COOLER FOR HIGHS NEAR KCHA THURSDAY DUE TO ANTICIPATED THICK CLOUD COVER. ALSO...WENT A LITTLE COOLER FOR SATURDAY LOWS/HIGHS...JUST THINKING MODELS ARE UNDERESTIMATING COOLNESS OF THIS AIR MASS. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 82 55 76 52 78 / 40 20 10 10 40 KNOXVILLE MCGHEE TYSON AIRPORT, TN 79 52 73 49 75 / 50 20 10 10 20 OAK RIDGE, TN 77 51 74 49 74 / 50 20 10 10 20 TRI CITIES AIRPORT, TN 74 49 66 43 71 / 20 20 20 10 20 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR THE FOLLOWING ZONES: CHEROKEE...CLAY. TN...WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR THE FOLLOWING ZONES: BLOUNT SMOKY MOUNTAINS...COCKE SMOKY MOUNTAINS... EAST POLK...JOHNSON...SEVIER SMOKY MOUNTAINS...SOUTHEAST CARTER...SOUTHEAST GREENE...SOUTHEAST MONROE...UNICOI. LAKE WIND ADVISORY UNTIL 4 PM EDT /3 PM CDT/ THIS AFTERNOON FOR THE FOLLOWING ZONES: ANDERSON...BLEDSOE...BRADLEY... CAMPBELL...CLAIBORNE...GRAINGER...HAMBLEN...HAMILTON... HANCOCK...HAWKINS...JEFFERSON...KNOX...LOUDON...MARION... MCMINN...MEIGS...MORGAN...NW BLOUNT...NORTH SEVIER... NORTHWEST CARTER...NORTHWEST COCKE...NORTHWEST GREENE... NORTHWEST MONROE...RHEA...ROANE...SCOTT TN...SEQUATCHIE... SULLIVAN...UNION...WASHINGTON TN...WEST POLK. VA...WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR THE FOLLOWING ZONES: WISE. LAKE WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR THE FOLLOWING ZONES: LEE...RUSSELL...SCOTT...WASHINGTON. && $$ DH tn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 933 AM CDT TUE MAY 20 2008 .UPDATE... WEAK FRONTAL BOUNDARY IS DRAPED NEAR THE RED RIVER AT THE PRESENT TIME. 12Z OUN AND FWD SOUNDINGS INDICATED VERY SHALLOW SURFACE MOISTURE...AND A LARGE DRY SLOT UP TO AROUND 15KFT. MID LEVEL CLOUDINESS IS EVIDENT ON SATELLITE ALONG WITH WEAK ECHOES ACROSS OKLAHOMA. SURFACE OBS IN OKLAHOMA VERIFY THAT THESE MID LEVEL ECHOES ARE NOT REACHING THE GROUND PRESENTLY. THEREFORE...WILL NOT INTRODUCE ANY MENTION IN WEATHER GRIDS UNLESS TRENDS SIGNIFICANTLY CHANGE. IF WE DO MANAGE TO GET ISOLATED CONVECTION GOING BY MIDDAY...BRIEF GUSTY WINDS MAY BE POSSIBLE DUE TO OUR SOUNDING PROFILE. OTHERWISE...EXPECT ANOTHER HOT DAY WITH ABOVE NORMAL TEMPS. AFTERNOON READINGS WILL BE HIGHEST OVER OUR SOUTHERN HALF...AS 850MB TEMPS IN THE MID 20S SURGE AHEAD OF THE FRONTAL BOUNDARY. HOWEVER...READINGS WILL BE TEMPERED BY MID LEVEL CLOUDINESS... ESPECIALLY OVER OUR NORTHERN COUNTIES. OVERALL...MAX TEMPS LOOK REASONABLE AND WILL NOT MAKE ANY ADJUSTMENTS AT THIS TIME. NO MAJOR UPDATES TO FORECAST REQUIRING A ZONE UPDATE...BUT WILL CONTINUE TO MONITOR TRENDS WITH MID LEVEL ECHOES. SCHULTZ && .PREV DISCUSSION... /ISSUED 617 AM CDT TUE MAY 20 2008/ AVIATION... /12Z UPDATE/ VFR CONDS TO PREVAIL ACROSS NORTH TEXAS THROUGH THE PERIOD. A WEAK FRONTAL BOUNDARY WILL SAG SOUTH THROUGH MIDDAY ALLOWING WINDS TO BECOME NORTHEAST BY 17Z. SOME SCT HIGH LEVEL CLOUDS WILL PASS BY THROUGH THE AFTERNOON. WILL MONITOR FOR A VERY ISOLATED SHOWER/TSTM ALONG FRONT THIS AFTN BUT OTHERWISE NO SIG AVIATION CONCERNS NEXT 24 HOURS. 91/DUNN PREV DISCUSSION... /ISSUED 525 AM CDT TUE MAY 20 2008/ 9Z RUC 850-1000MB THICKNESS FORECAST FOR THIS AFTERNOON ACROSS THE SW SUGGEST PREVIOUS HIGH TEMP FORECAST FOR TODAY WAS TOO COOL. HAVE BUMPED UP HIGHS 2-3 DEGREES IN THE SW ZONES. PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAY 20 2008/ A VERY WEAK COLD FRONT IS CURRENTLY BECOMING BETTER DEFINED ACROSS NW TEXAS ON THE BACK SIDE OF YESTERDAY/S REMNANT THERMAL CYCLONE NOW LOCATED SW OF WICHITA FALLS. SOUTHWARD FRONTAL MOVEMENT WILL BE AUGMENTED BY VEERING MID LEVEL FLOW IN RESPONSE TO A WEAK SHORTWAVE MOVING INTO THE LOWER MISSISSIPPI VALLEY. THE AXIS OF WARMEST LOW LEVEL THICKNESS VALUES WILL BE SHUNTED SOUTHWARD FROM THE NW ZONES INTO THE SW ZONES DURING THE DAY. THEREFORE...HIGHS WILL BE A FEW DEGREES COOLER OVER THE NORTHERN CWA...BUT A COUPLE DEGREES WARMER OVER THE SOUTH AHEAD OF THE FRONT. WACO SHOULD BREAK THEIR RECORD HIGH OF 95 LAST SET IN 1996. AN ISOLATED SHOWER OR STORM ALONG THE FRONT WILL BE POSSIBLE THIS AFTERNOON WHEN CIN MAY BECOME NEGLIGIBLE. THE LACK OF UPPER LEVEL LIFTING SUPPORT WARRANTS NO INCLUSION OF POPS IN THE WORDED FORECAST ATTM. THE FRONT WILL GRADUALLY MOVE THROUGH THE SOUTHERN CWA THIS EVENING BEFORE WASHING OUT. EAST TO NORTHEAST WINDS WILL BRING IN SLIGHTLY COOLER AIR TO THE REGION AND THEREFORE WEDNESDAY HIGH TEMPS WILL BE A LITTLE COOLER. A DEVELOPING LARGE AND DEEP UPPER LEVEL TROUGH OVER THE WESTERN CONUS WILL CAUSE SOUTHERLY WINDS TO INCREASE LATE WEDNESDAY AND INTO THE WEEKEND. WARMER OVERNIGHT LOW TEMPERATURES AND LATE NIGHT/MORNING STRATUS WILL BE THE RESULT. HIGH TEMPERATURES SHOULD REMAIN GENERALLY IN THE LOWER 90S WITH LOWS IN THE LOW TO MID 70S THROUGH EARLY NEXT WEEK. THE CHANCES OF RAIN LOOK RATHER LOW AS THE WESTERN SYSTEM FAILS TO ADVANCE EASTWARD. UPPER LEVEL RIDGING WILL BUILD IN ACROSS THE MIDWEST AND EVENTUALLY SLIDE SOUTHWEST TO ENCOMPASS THE REGION NEXT WEEK. ALTHOUGH MOISTURE/INSTABILITY WILL BE IN PLACE FOR CONVECTION...CIN WILL BE TOUGH TO OVERCOME IN THE ABSENCE OF UPPER LEVEL LIFT. THURSDAY AND FRIDAY MAY BE THE BEST SHOT AT ISOLATED AFTERNOON OR EVENING SHOWERS AND STORMS. WILL KEEP POPS AT 20 PERCENT THURSDAY THROUGH SATURDAY BEFORE HEIGHT RISES ASSOCIATED WITH THE BUILDING UPPER LEVEL HIGH PROMOTE SUBSIDENCE THEREAFTER. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 66 92 74 92 / 10 10 5 5 20 WACO, TX 99 67 92 73 92 / 5 5 10 10 20 PARIS, TX 89 59 87 68 89 / 10 10 5 5 20 DENTON, TX 93 62 91 73 92 / 10 5 5 5 20 MCKINNEY, TX 91 61 90 72 90 / 10 10 5 5 20 DALLAS, TX 94 67 92 74 92 / 10 10 5 5 20 TERRELL, TX 92 62 90 72 91 / 10 10 5 5 20 CORSICANA, TX 94 64 91 72 91 / 10 10 10 10 20 TEMPLE, TX 97 68 92 72 92 / 5 5 10 10 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FORT WORTH TX 617 AM CDT TUE MAY 20 2008 .AVIATION... /12Z UPDATE/ VFR CONDS TO PREVAIL ACROSS NORTH TEXAS THROUGH THE PERIOD. A WEAK FRONTAL BOUNDARY WILL SAG SOUTH THROUGH MIDDAY ALLOWING WINDS TO BECOME NORTHEAST BY 17Z. SOME SCT HIGH LEVEL CLOUDS WILL PASS BY THROUGH THE AFTERNOON. WILL MONITOR FOR A VERY ISOLATED SHOWER/TSTM ALONG FRONT THIS AFTN BUT OTHERWISE NO SIG AVIATION CONCERNS NEXT 24 HOURS. 91/DUNN && .PREV DISCUSSION... /ISSUED 525 AM CDT TUE MAY 20 2008/ 9Z RUC 850-1000MB THICKNESS FORECAST FOR THIS AFTERNOON ACROSS THE SW SUGGEST PREVIOUS HIGH TEMP FORECAST FOR TODAY WAS TOO COOL. HAVE BUMPED UP HIGHS 2-3 DEGREES IN THE SW ZONES. && .PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAY 20 2008/ A VERY WEAK COLD FRONT IS CURRENTLY BECOMING BETTER DEFINED ACROSS NW TEXAS ON THE BACK SIDE OF YESTERDAY/S REMNANT THERMAL CYCLONE NOW LOCATED SW OF WICHITA FALLS. SOUTHWARD FRONTAL MOVEMENT WILL BE AUGMENTED BY VEERING MID LEVEL FLOW IN RESPONSE TO A WEAK SHORTWAVE MOVING INTO THE LOWER MISSISSIPPI VALLEY. THE AXIS OF WARMEST LOW LEVEL THICKNESS VALUES WILL BE SHUNTED SOUTHWARD FROM THE NW ZONES INTO THE SW ZONES DURING THE DAY. THEREFORE...HIGHS WILL BE A FEW DEGREES COOLER OVER THE NORTHERN CWA...BUT A COUPLE DEGREES WARMER OVER THE SOUTH AHEAD OF THE FRONT. WACO SHOULD BREAK THEIR RECORD HIGH OF 95 LAST SET IN 1996. AN ISOLATED SHOWER OR STORM ALONG THE FRONT WILL BE POSSIBLE THIS AFTERNOON WHEN CIN MAY BECOME NEGLIGIBLE. THE LACK OF UPPER LEVEL LIFTING SUPPORT WARRANTS NO INCLUSION OF POPS IN THE WORDED FORECAST ATTM. THE FRONT WILL GRADUALLY MOVE THROUGH THE SOUTHERN CWA THIS EVENING BEFORE WASHING OUT. EAST TO NORTHEAST WINDS WILL BRING IN SLIGHTLY COOLER AIR TO THE REGION AND THEREFORE WEDNESDAY HIGH TEMPS WILL BE A LITTLE COOLER. A DEVELOPING LARGE AND DEEP UPPER LEVEL TROUGH OVER THE WESTERN CONUS WILL CAUSE SOUTHERLY WINDS TO INCREASE LATE WEDNESDAY AND INTO THE WEEKEND. WARMER OVERNIGHT LOW TEMPERATURES AND LATE NIGHT/MORNING STRATUS WILL BE THE RESULT. HIGH TEMPERATURES SHOULD REMAIN GENERALLY IN THE LOWER 90S WITH LOWS IN THE LOW TO MID 70S THROUGH EARLY NEXT WEEK. THE CHANCES OF RAIN LOOK RATHER LOW AS THE WESTERN SYSTEM FAILS TO ADVANCE EASTWARD. UPPER LEVEL RIDGING WILL BUILD IN ACROSS THE MIDWEST AND EVENTUALLY SLIDE SOUTHWEST TO ENCOMPASS THE REGION NEXT WEEK. ALTHOUGH MOISTURE/INSTABILITY WILL BE IN PLACE FOR CONVECTION...CIN WILL BE TOUGH TO OVERCOME IN THE ABSENCE OF UPPER LEVEL LIFT. THURSDAY AND FRIDAY MAY BE THE BEST SHOT AT ISOLATED AFTERNOON OR EVENING SHOWERS AND STORMS. WILL KEEP POPS AT 20 PERCENT THURSDAY THROUGH SATURDAY BEFORE HEIGHT RISES ASSOCIATED WITH THE BUILDING UPPER LEVEL HIGH PROMOTE SUBSIDENCE THEREAFTER. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 66 92 74 92 / 10 10 5 5 20 WACO, TX 99 67 92 73 92 / 5 5 10 10 20 PARIS, TX 89 59 87 68 89 / 10 10 5 5 20 DENTON, TX 93 62 91 73 92 / 10 5 5 5 20 MCKINNEY, TX 91 61 90 72 90 / 10 10 5 5 20 DALLAS, TX 94 67 92 74 92 / 10 10 5 5 20 TERRELL, TX 92 62 90 72 91 / 10 10 5 5 20 CORSICANA, TX 94 64 91 72 91 / 10 10 10 10 20 TEMPLE, TX 97 68 92 72 92 / 5 5 10 10 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 92/91 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RENO NV 322 PM PDT TUE MAY 20 2008 .SHORT TERM... TROUGH MOVING ONSHORE WITH COLD FRONT DRIVING SOUTH THROUGH LASSEN AND NORTHERN WASHOE COUNTIES. NORTH-SOUTH PRESSURE GRADIENT ACROSS THE FORECAST AREA IS AT 10-12 MILLIBARS. USING THE 2PM OBSERVATIONS FROM LOVELOCK AND ALTURAS THE THERMAL GRADIENT ACROSS THE FRONT WAS NEARLY 40 DEGREES. WINDS ARE RESPONDING TO THIS WITH GUSTS NEAR 45 MPH ALONG I-80 AND US-50. FARTHER SOUTH WINDS HAVE BEEN SLOW TO RESPOND...BUT WILL INCREASE AS THE STRONG FRONT NEARS. WILL KEEP THE GUSTS TO 50 MPH GOING...BUT WINDS COULD BE SLIGHTLY HIGHER AN HOUR OR SO BEFORE THE FRONT ARRIVES. A COUPLE OF IMPRESSIVE THUNDERSTORMS DEVELOPED AHEAD OF THE FRONT IN LASSEN COUNTY. STORMS HAD EXCELLENT ROTATION AND DEVELOPED VERY QUICKLY. SHOWERS WILL BE MORE COMMON THAN THE THUNDERSTORMS ALONG THE FRONT...BUT ANY THUNDERSTORMS THAT DO DEVELOP WILL HAVE PLENTY OF SHEAR AVAILABLE TO THEM...AND ALSO MOVE VERY QUICKLY. STORM MOTION CALCULATED OFF THE RUC13 IS NEAR 40 KTS. UNCERTAINLY REMAINS IN THE POSITION OF ENERGY THAT FILLS INTO THE TROUGH AS IT REMAINS IN PLACE OVER THE INTERMOUNTAIN WEST FOR THE NEXT FEW DAYS. DOES APPEAR SHOWER ACTIVITY WILL RESPOND TO AFTERNOON HEATING AS THE COLD POOL ALOFT WILL BE IN PLACE. STILL COULD SEE SLIGHT CHANCE OF SHOWERS ON THURSDAY AND FRIDAY...THE FLOW ON WEDNESDAY LOOKS TOO DRY AND SUBSIDENT TO GET ANY SHOWERS. MODELS ARE STARTING TO PICK UP ON INSTABILITY OVER THE SIERRA ON FRIDAY...BUT DID NOT ADD THUNDER YET AS MODELS CONTINUE TO FLUCTUATE. WINDS WILL REMAIN FROM THE NORTH TO NORTHEAST AFTER THE FRONT PASSES AND SHOULD REMAIN GUSTY THROUGH FRIDAY. COULD BE ENOUGH FOR A LAKE WIND ADVISORY ON TAHOE TOMORROW AS THE SURFACE PRESSURE GRADIENT REMAINS...BUT THINKING IS WINDS WILL REMAIN JUST BELOW LAKE WIND ADVISORY CRITERIA. HIGH TEMPERATURES WILL REMAIN BELOW NORMAL THE NEXT COUPLE DAYS WITH THE COLD POOL AND CLOUD COVER LIMITING SURFACE HEATING. DID LEAVE TEMPERATURES BELOW GUIDANCE...ESPECIALLY FOR WEDNESDAY. CLOUD COVER WILL KEEP THE LOWS AT OR JUST ABOVE NORMAL...BUT IF SKIES CLEAR TEMPERATURES SHOULD DROP INTO THE MID 30S...EXCEPT THE LARGE POPULATION CENTERS. IF YOU DO HAVE PLANTS OUTSIDE...BRING THEM IN OR COVER TO PROTECT THEM FROM THE COOL TEMPERATURES THE NEXT 3 NIGHTS. BRONG .LONG TERM...SATURDAY THROUGH TUESDAY... UNSETTLED WEATHER THROUGH MOST OF THE EXTENDED PERIOD. ON SATURDAY THE DEEP UPPER LOW IS PROGGED TO STILL BE OVER THE WRN CONUS. THE GFS HAS 500 MB HEIGHTS DROPPING TO 552 DAM OVER THE NRN SIERRA BY 18Z SATURDAY. THE HIGH SUN ANGLES THIS TIME OF YEAR WILL HELP THE LWR AIR MASS TO STAY WARM WITH AFTN HIGHS ON SATURDAY IN THE UPPER 60S TO AROUND 70 IN WRN NEVADA VALLEYS...ONLY AROUND 5 DEGREES BELOW NORMAL FOR LATE MAY. HOWEVER THE COLD AIR ALOFT WILL HELP TO INCREASE LAPSE RATES AND ASSOCIATED INSTABILITY VALUES. WILL CONTINUE WITH A CHANCE OF SHRA AND TSTMS ACROSS THE ENTIRE CWFA ON SATURDAY. WITH NO SYNOPTIC FEATURE TO NUDGE THE UPPER LOW TO THE EAST CONDITIONS ON SUNDAY WILL BE SIMILAR TO THOSE ON SATURDAY. SCT SHRA AND TSTMS ARE AGAIN POSSIBLE ON SUNDAY. ON MONDAY THE GFS AND ECMWF HAVE AN UPPER LOW MOVING TOWARD BRITISH COLUMBIA. A COLD FRONT IS PROGGED TO REACH THE OREGON COAST LATE ON MONDAY. AN UPPER JET ASSOCIATED WITH THIS SYSTEM WILL HELP TO WEAKEN THE LOW OVER THE GREAT BASIN AND FINALLY MOVE IT TO THE EAST. COLD AIR WILL REMAIN ALOFT HOWEVER ON MONDAY AND...WITH CYCLONIC FLOW CONTRIBUTING PVA...WILL CONTINUE WITH MOSTLY CLOUDY SKIES AND A SLIGHT CHANCE OF SHRA AND TSTMS. BY TUESDAY THE SYNOPTIC PATTERN SHOULD SHARPLY AMPLIFY AS ANOTHER LOW DEEPENS JUST OFF THE WEST COAST. SLY FLOW AHEAD OF THE UPPER TROUGH WILL BRING WAA TO THE WRN GREAT BASIN. AFTN TEMPERATURES IN WRN NEVADA SHOULD WARM INTO THE UPPER 70S ON TUESDAY WITH DRY CONDITIONS EXPECTED BEFORE THIS NEXT SYSTEM MOVES INLAND. O`HARA && .AVIATION... VFR CONDITIONS WILL CONTINUE THROUGH WEDNESDAY. WITH COLD FRONTAL PASSAGE THIS EVENING LCL WIND GUSTS TO 40 MPH ARE POSSIBLE UNTIL 05Z. O`HARA && .FIRE WEATHER... RH VALUES HAVE REMAINED VERY LOW ACROSS CENTRAL AND SOUTHERN PORTIONS OF THE DISTRICT THIS AFTERNOON...AHEAD OF APPROACHING COLD FRONT. SINGLE DIGIT RH READINGS ARE WIDESPREAD ACROSS ZONES 453/459 PER OBS AND RTMA. AFTER FRONTAL PASSAGE TONIGHT HOWEVER...RH VALUES WILL RECOVER QUICKLY. SOME VALLEY LOCATIONS IN LASSEN-WASHOE COUNTIES MAY SEE 24HR RH INCREASES OF 50% OR MORE COMPARED TO LAST NIGHT! STRONG SW WINDS ARE EXPECTED TO CONTINUE INTO THE EVENING HOURS AHEAD OF THE FRONT...BEFORE SWITCHING TO THE NW AND DECREASING OVERNIGHT. BEHIND THE FRONT...BUFKIT SOUNDINGS SHOW WINDS REMAINING GUSTY THROUGH THURSDAY HOWEVER MIN RH VALUES ARE EXPECTED TO GENERALLY REMAIN AT OR ABOVE 20% WITHIN A COOLER/MORE MOIST AIR MASS. CS && .REV WATCHES/WARNINGS/ADVISORIES... NV...WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR NVZ001-003-004. LAKE WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR NVZ002. CA...WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR CAZ073. LAKE WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR CAZ072. && $$ HTTP://WEATHER.GOV/RENO ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 305 PM CDT TUE MAY 20 2008 .DISCUSSION... A WEAK COLD FRONT HAS EDGED INTO THE SOUTHEASTERN NEW MEXICO PLAINS AND THE NORTHERN PERMIAN BASIN THIS AFTERNOON. NOT MUCH COOLING BEHIND THIS BOUNDARY...AS TEMPERATURES ARE GENERALLY IN THE LOWER TO MID 90S WITH EASTERLY WINDS...AS OPPOSED TO READINGS NEAR OR ABOVE 100 AHEAD OF THE FRONT. SCATTERED HIGH BASED CU/ALTOCU ARE DEVELOPING MAINLY FROM THE DAVIS MOUNTAINS TO THE LOWER TRANS PECOS REGION THIS AFTERNOON. GIVEN NEGATIVE LI/S AND STEEP LAPSE RATES...AN ISOLATED HIGH-BASED THUNDERSTORM REMAINS POSSIBLE THROUGH THE REST OF THE AFTERNOON. LITTLE OR NO RAIN WOULD OCCUR...BUT OCCASIONAL DRY LIGHTNING STRIKES AND STRONG WIND GUSTS WOULD BE A POSSIBILITY IF A STORM MANAGES TO DEVELOP. AFTERNOON RUC 500 MB HEIGHT ANALYSIS SHOWS THE UPPER LEVEL RIDGE AXIS NOSING ACROSS WEST TX AND SOUTHEAST NM...WITH THE CENTER OF THE UPPER HIGH ACROSS SOUTHERN AZ. THIS MATCHES WELL WITH MODEL INITIALIZATIONS. MODELS ARE IN AGREEMENT THAT THE UPPER RIDGE WILL BREAK DOWN TONIGHT AS AN UPPER LEVEL TROUGH BEGINS TO DEEPEN ACROSS THE NORTHWESTERN CONUS. SOUTHWESTERLY FLOW ALOFT WILL BEGIN TO INCREASE ACROSS WEST TX/SOUTHEAST NM WEDNESDAY AS THE UPPER TROUGH BEGINS TO AMPLIFY/DEEPEN ACROSS NV/UT/FOUR CORNERS REGION. DRY AIR AT THE SURFACE IS STILL EXPECTED TO ADVANCE THROUGH MOST OF THE CWFA...WITH AFTERNOON DEWPOINTS IN THE 20S AND 30S. AN INCREASING PRESSURE GRADIENT ALONG THE LEE TROUGH WILL LIKELY BRING WINDY CONDITIONS TO MUCH OF THE FORECAST AREA. IN ADDITION...STRONG LOW LEVEL THERMAL RIDGING WILL RESULT IN ANOTHER HOT DAY...WITH HIGHS LIKELY EXCEEDING 100 F AGAIN OVER MANY LOCATIONS. WILL ALSO MENTION THAT ANOTHER HIGH BASED THUNDERSTORM OR TWO WILL NOT BE OUT OF THE REALM OF POSSIBILITY AS A WEAK SHORTWAVE TROUGH PUSHES ACROSS THE REGION WITH STEEP MID LEVEL LAPSE RATES. POTENTIAL IS TOO LOW TO MENTION IN GRIDS AT THIS POINT...BUT DID KEEP TRIVIAL LOW POPS. ALSO OF CONCERN TOMORROW WILL BE THE POTENTIAL FOR HIGH WINDS ACROSS THE GUADALUPE MTNS. MODELS ARE COMING MORE INTO AGREEMENT WITH STRONGER 700 MB WINDS...GENERALLY AROUND 30 KNOTS ACROSS THE GUADALUPES. VARIOUS MOS GUIDANCE SEEMS TO BE MORE IN AGREEMENT ON A MARGINAL HIGH WIND EVENT...SO HAVE ISSUED A HIGH WIND WATCH EFFECTIVE FROM 17Z TO 02Z. ANOTHER WINDY AND DRY DAY LOOKS PROBABLE FOR THURSDAY. THE SURFACE LEE TROUGH WILL HOLD STRONG ACROSS WEST TX/SOUTHEAST NM...WITH BREEZY S/SW WINDS ACROSS THE REGION. STRONG LOW LEVEL THERMAL RIDGING WILL LIKELY BRING ABOVE NORMAL TEMPERATURES AGAIN...ALBEIT SLIGHTLY COOLER THAN WEDNESDAY. DRY AIR SHOULD REMAIN IN PLACE ACROSS MUCH OF THE REGION THURSDAY NIGHT INTO FRIDAY...BUT A MORE MOIST/UNSTABLE AIRMASS SHOULD BEGIN TO RETURN BACK TO THE REGION BEGINNING LATE FRIDAY. AS THE UPPER LEVEL FLOW CONTINUES TO BACK TO A MORE S/SW DIRECTION LATE FRIDAY...AND SERIES OF SHORTWAVE TROUGHS WITHIN THE FLOW MOVE ACROSS THE REGION...SCATTERED THUNDERSTORMS STILL APPEAR REASONABLE...ESPECIALLY ACROSS THE EASTERN HALF OF THE REGION. LOW POPS WERE RETAINED THIS WEEKEND THROUGH EARLY NEXT WEEK AS SOUTHWESTERLY FLOW ALOFT PERSISTS. ONE CONCERN WILL BE A WESTWARD BUILDING UPPER LEVEL RIDGE OF HIGH PRESSURE EARLY NEXT WEEK. MEDIUM RANGE MODEL PROGS INDICATE THAT THIS RIDGE WILL PRIMARILY REMAIN TO OUR EAST...WITH MID LEVEL MOISTURE AND INSTABILITY REMAINING ACROSS PORTIONS OF OUR CWFA...SO ISOLATED STORMS WILL BE CARRIED THROUGH EARLY NEXT WEEK. && .FIRE WEATHER... FIRE WX CONCERNS CONTINUE TO ESCALATE ACRS THE AREA WITH NEAR RECORD TEMPS...INCREASING WINDS...AND SINGLE DIGIT RH. UNSEASONAL HOT SPELL HAS DEVELOPED ACRS W TX/SE NM IN RESPONSE TO PRESENCE OF MID LEVEL ANTICYCLONE AND WEAK NW FLOW ALOFT. AIR HAS BEEN STAGNANT ACRS THE HIER ELEVATIONS OF THE SWRN STATES ALLOWING IT REALLY HEAT UP AT 7H...14C AS FAR E AS MAF TDY. STILL HAVE LOW PROBABILITY CONCERNS FOR DRY LIGHTNING TDY WITH CU FIELD SHOWING SIGNS OF ENHANCEMENT IN SAC MTNS...NEAR ALPINE...AND GLASS MTNS. MID LEVEL RIDGE WILL BREAK DOWN QUICKLY WED AS SHARP MID LEVEL TROF NEARS THE 4 CORNERS REGION. AS SW MID LEVEL FLOW INCREASES E OF SAID TROF THESE INCREDIBLY WARM 7H TEMPS WILL BE ADVECTED E INTO SE NM/W TX WED WITH NAM DEPICTING 7H THERMAL RIDGE OF 16C ALONG TX/NM BORDER. THIS IS A CRITICAL FIRE WX PATTERN...BREAK DOWN OF THE MID LEVEL RIDGE. THIS WILL INDUCE IMPRESSIVE 12HR PRESSURE FALLS OF 16MB. THIS ALONG WITH TIGHTENING MSLP GRADIENT AND MIXING OF 25-30KT 85H-7H WINDS WILL BE SUFFICIENT FOR SFC WINDS OF 20-25 MPH ACRS MUCH OF THE PLAINS. THESE MID TEEN 7H TEMPS WILL TRANSLATE TO TRIPLE DIGIT HEAT AND SINGLE DIGIT RH PROVIDING A REAL TEST FOR CRITICALLY DRY FUELS. WITHIN THE SFC TROF AXIS ACRS PARTS OF THE TRANS PECOS WINDS WILL BE LIGHTER THOUGH AND WILL CONTINUE TO KEEP THOSE AREAS OUT OF THE WATCH/WARNING FOR NOW. SIMILAR OCCURRENCE THURS ALTHOUGH IT WILL BE A LITTLE COOLER AS BETTER 5H HGHT FALLS MOVE INTO AREA AND 7H TEMPS COOL. ATTP CONFIDENCE IS HIER WITH THE WED FCST. THUR...5H TROF WILL BE CLOSE ENOUGH TO INCREASE MID LEVEL LIFT (SEE 7H OMEGA) AND INHIBIT OR DELAY MIXING...AND MSLP GRADIENT WON/T BE AS GOOD. STILL 25KTS 85H-7H WILL BE SUFFICIENT TO INCREASE WINDS TO AROUND 20 MPH. TEMPS IN M90S WILL ENUF FOR MIN RH/S TO FALL BLO 10 PCT AGAIN. WINDS WILL BE STRONGER FARTHER S AND WILL ISSUE FIRE WX WATCH FOR THURSDAY THAT WILL ENCOMPASS A GREATER AREA...SOUTH TO THE RIO GRANDE. && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 67 102 69 97 / 0 10 10 10 CARLSBAD NM 62 102 66 94 / 0 0 10 0 DRYDEN TX 66 102 69 99 / 0 10 10 10 FORT STOCKTON TX 67 104 69 99 / 0 10 10 10 GUADALUPE PASS TX 61 97 60 89 / 0 0 10 0 HOBBS NM 63 103 64 93 / 0 10 10 10 MARFA TX 54 96 52 90 / 0 10 10 0 MIDLAND INTL AIRPORT TX 66 102 68 97 / 0 10 10 10 ODESSA TX 67 102 69 97 / 0 10 10 10 WINK TX 66 108 68 102 / 0 10 10 10 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...FIRE WEATHER WATCH FROM 12 PM TO 8 PM MDT THURSDAY FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS NP/LINCOLN NF/LNZ... SOUTHEAST PLAINS/BLM ROSWELL/LNZ. RED FLAG WARNING FROM 11 AM TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS NP/LINCOLN NF/LNZ... SOUTHEAST PLAINS/BLM ROSWELL/LNZ. HIGH WIND WATCH FROM 11 AM TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS OF EDDY COUNTY. TX...FIRE WEATHER WATCH FROM 1 PM CDT /12 PM MDT/ TO 9 PM CDT /8 PM MDT/ THURSDAY FOR THE FOLLOWING ZONES...ANDREWS...BIG BEND AREA...BORDEN...CRANE...DAVIS/APACHE MOUNTAINS AREA... DAWSON...ECTOR...GAINES...GLASSCOCK...GUADALUPE MOUNTAINS... HOWARD...LOVING...MARFA PLATEAU...MARTIN...MIDLAND... MITCHELL...PECOS...PRESIDIO VALLEY...REAGAN...REEVES COUNTY AND UPPER TRANS PECOS...SCURRY...TERRELL...UPTON...VAN HORN AND HIGHWAY 54 CORRIDOR...WARD...WINKLER. RED FLAG WARNING FROM 12 PM CDT /11 AM MDT/ TO 9 PM CDT /8 PM MDT/ WEDNESDAY FOR THE FOLLOWING ZONES...ANDREWS...BORDEN... CRANE...DAWSON...ECTOR...GAINES...GLASSCOCK...GUADALUPE MOUNTAINS...HOWARD...LOVING...MARTIN...MIDLAND...MITCHELL... REAGAN...REEVES COUNTY AND UPPER TRANS PECOS...SCURRY... UPTON...VAN HORN AND HIGHWAY 54 CORRIDOR...WARD...WINKLER. HIGH WIND WATCH FROM 11 AM TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS. && $$ 49/21 tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 1142 AM CDT TUE MAY 20 2008 .AVIATION... S/W IN NW FLOW ALOFT WILL CONTINUE IT PUSH SEWD ACROSS SE OK/NE-E TX THROUGH 00Z. AS IT DOES SO...CURRENT WK CD FNT DRAPED JUST W-N OF D/FW METRO SHOULD GET MOVING THROUGH THE I-20 CORRIDOR...WITH N WNDS 5-10 KTS...GOING NE 10-14 KTS...WITH A FEW GSTS TO 18-20 KTS PSBLE WITH MIXING. PATCHY ACCAS WITH SOME CC/CS CIGS WILL LINGER THROUGH THE AFTN WITH SOME ISOLD VIRGA PSBL AND AN ISOLD TS/CG STRIKE OR TWO PSBL ONCE MAX HEATING OCCURS BY 21Z. COVERAGE AND CONFIDENCE HOWEVER NOT ENOUGH FOR MENTION IN D/FW AIRPORT TAFS ATTM. VFR TO RULE...THOUGH BRIEF MVFR CIGS MAY OCCUR BRIEFLY ARND 12Z WED KACT VCNTY. && .PREV DISCUSSION... /ISSUED 1131 AM CDT TUE MAY 20 2008/ UPDATE... TEMPERATURES ON A SLOWER WARMING TREND THIS MORNING THAN THIS TIME YESTERDAY. BASED ON CURRENT TRENDS...IT APPEARS RATHER DIFFICULT FOR OUR SOUTHERN AND SOUTHWESTERN ZONES TO APPROACH 100 DEGREES. AS A RESULT...HAVE LOWERED MAX TEMPS OVER MUCH OF THE AREA. SCHULTZ PREV DISCUSSION... /ISSUED 933 AM CDT TUE MAY 20 2008/ UPDATE... WEAK FRONTAL BOUNDARY IS DRAPED NEAR THE RED RIVER AT THE PRESENT TIME. 12Z OUN AND FWD SOUNDINGS INDICATED VERY SHALLOW SURFACE MOISTURE...AND A LARGE DRY SLOT UP TO AROUND 15KFT. MID LEVEL CLOUDINESS IS EVIDENT ON SATELLITE ALONG WITH WEAK ECHOES ACROSS OKLAHOMA. SURFACE OBS IN OKLAHOMA VERIFY THAT THESE MID LEVEL ECHOES ARE NOT REACHING THE GROUND PRESENTLY. THEREFORE...WILL NOT INTRODUCE ANY MENTION IN WEATHER GRIDS UNLESS TRENDS SIGNIFICANTLY CHANGE. IF WE DO MANAGE TO GET ISOLATED CONVECTION GOING BY MIDDAY...BRIEF GUSTY WINDS MAY BE POSSIBLE DUE TO OUR SOUNDING PROFILE. OTHERWISE...EXPECT ANOTHER HOT DAY WITH ABOVE NORMAL TEMPS. AFTERNOON READINGS WILL BE HIGHEST OVER OUR SOUTHERN HALF...AS 850MB TEMPS IN THE MID 20S SURGE AHEAD OF THE FRONTAL BOUNDARY. HOWEVER...READINGS WILL BE TEMPERED BY MID LEVEL CLOUDINESS... ESPECIALLY OVER OUR NORTHERN COUNTIES. OVERALL...MAX TEMPS LOOK REASONABLE AND WILL NOT MAKE ANY ADJUSTMENTS AT THIS TIME. NO MAJOR UPDATES TO FORECAST REQUIRING A ZONE UPDATE...BUT WILL CONTINUE TO MONITOR TRENDS WITH MID LEVEL ECHOES. SCHULTZ PREV DISCUSSION... /ISSUED 617 AM CDT TUE MAY 20 2008/ AVIATION... /12Z UPDATE/ VFR CONDS TO PREVAIL ACROSS NORTH TEXAS THROUGH THE PERIOD. A WEAK FRONTAL BOUNDARY WILL SAG SOUTH THROUGH MIDDAY ALLOWING WINDS TO BECOME NORTHEAST BY 17Z. SOME SCT HIGH LEVEL CLOUDS WILL PASS BY THROUGH THE AFTERNOON. WILL MONITOR FOR A VERY ISOLATED SHOWER/TSTM ALONG FRONT THIS AFTN BUT OTHERWISE NO SIG AVIATION CONCERNS NEXT 24 HOURS. 91/DUNN PREV DISCUSSION... /ISSUED 525 AM CDT TUE MAY 20 2008/ 9Z RUC 850-1000MB THICKNESS FORECAST FOR THIS AFTERNOON ACROSS THE SW SUGGEST PREVIOUS HIGH TEMP FORECAST FOR TODAY WAS TOO COOL. HAVE BUMPED UP HIGHS 2-3 DEGREES IN THE SW ZONES. PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAY 20 2008/ A VERY WEAK COLD FRONT IS CURRENTLY BECOMING BETTER DEFINED ACROSS NW TEXAS ON THE BACK SIDE OF YESTERDAY/S REMNANT THERMAL CYCLONE NOW LOCATED SW OF WICHITA FALLS. SOUTHWARD FRONTAL MOVEMENT WILL BE AUGMENTED BY VEERING MID LEVEL FLOW IN RESPONSE TO A WEAK SHORTWAVE MOVING INTO THE LOWER MISSISSIPPI VALLEY. THE AXIS OF WARMEST LOW LEVEL THICKNESS VALUES WILL BE SHUNTED SOUTHWARD FROM THE NW ZONES INTO THE SW ZONES DURING THE DAY. THEREFORE...HIGHS WILL BE A FEW DEGREES COOLER OVER THE NORTHERN CWA...BUT A COUPLE DEGREES WARMER OVER THE SOUTH AHEAD OF THE FRONT. WACO SHOULD BREAK THEIR RECORD HIGH OF 95 LAST SET IN 1996. AN ISOLATED SHOWER OR STORM ALONG THE FRONT WILL BE POSSIBLE THIS AFTERNOON WHEN CIN MAY BECOME NEGLIGIBLE. THE LACK OF UPPER LEVEL LIFTING SUPPORT WARRANTS NO INCLUSION OF POPS IN THE WORDED FORECAST ATTM. THE FRONT WILL GRADUALLY MOVE THROUGH THE SOUTHERN CWA THIS EVENING BEFORE WASHING OUT. EAST TO NORTHEAST WINDS WILL BRING IN SLIGHTLY COOLER AIR TO THE REGION AND THEREFORE WEDNESDAY HIGH TEMPS WILL BE A LITTLE COOLER. A DEVELOPING LARGE AND DEEP UPPER LEVEL TROUGH OVER THE WESTERN CONUS WILL CAUSE SOUTHERLY WINDS TO INCREASE LATE WEDNESDAY AND INTO THE WEEKEND. WARMER OVERNIGHT LOW TEMPERATURES AND LATE NIGHT/MORNING STRATUS WILL BE THE RESULT. HIGH TEMPERATURES SHOULD REMAIN GENERALLY IN THE LOWER 90S WITH LOWS IN THE LOW TO MID 70S THROUGH EARLY NEXT WEEK. THE CHANCES OF RAIN LOOK RATHER LOW AS THE WESTERN SYSTEM FAILS TO ADVANCE EASTWARD. UPPER LEVEL RIDGING WILL BUILD IN ACROSS THE MIDWEST AND EVENTUALLY SLIDE SOUTHWEST TO ENCOMPASS THE REGION NEXT WEEK. ALTHOUGH MOISTURE/INSTABILITY WILL BE IN PLACE FOR CONVECTION...CIN WILL BE TOUGH TO OVERCOME IN THE ABSENCE OF UPPER LEVEL LIFT. THURSDAY AND FRIDAY MAY BE THE BEST SHOT AT ISOLATED AFTERNOON OR EVENING SHOWERS AND STORMS. WILL KEEP POPS AT 20 PERCENT THURSDAY THROUGH SATURDAY BEFORE HEIGHT RISES ASSOCIATED WITH THE BUILDING UPPER LEVEL HIGH PROMOTE SUBSIDENCE THEREAFTER. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 66 92 74 92 / 10 10 5 5 20 WACO, TX 95 67 92 73 92 / 5 5 10 10 20 PARIS, TX 89 59 87 68 89 / 10 10 5 5 20 DENTON, TX 93 62 91 73 92 / 10 5 5 5 20 MCKINNEY, TX 91 61 90 72 90 / 10 10 5 5 20 DALLAS, TX 93 67 92 74 92 / 10 10 5 5 20 TERRELL, TX 92 62 90 72 91 / 10 10 5 5 20 CORSICANA, TX 93 64 91 72 91 / 10 10 10 10 20 TEMPLE, TX 96 68 92 72 92 / 5 5 10 10 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21/99/05 tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 1131 AM CDT TUE MAY 20 2008 .UPDATE... TEMPERATURES ON A SLOWER WARMING TREND THIS MORNING THAN THIS TIME YESTERDAY. BASED ON CURRENT TRENDS...IT APPEARS RATHER DIFFICULT FOR OUR SOUTHERN AND SOUTHWESTERN ZONES TO APPROACH 100 DEGREES. AS A RESULT...HAVE LOWERED MAX TEMPS OVER MUCH OF THE AREA. SCHULTZ && .PREV DISCUSSION... /ISSUED 933 AM CDT TUE MAY 20 2008/ UPDATE... WEAK FRONTAL BOUNDARY IS DRAPED NEAR THE RED RIVER AT THE PRESENT TIME. 12Z OUN AND FWD SOUNDINGS INDICATED VERY SHALLOW SURFACE MOISTURE...AND A LARGE DRY SLOT UP TO AROUND 15KFT. MID LEVEL CLOUDINESS IS EVIDENT ON SATELLITE ALONG WITH WEAK ECHOES ACROSS OKLAHOMA. SURFACE OBS IN OKLAHOMA VERIFY THAT THESE MID LEVEL ECHOES ARE NOT REACHING THE GROUND PRESENTLY. THEREFORE...WILL NOT INTRODUCE ANY MENTION IN WEATHER GRIDS UNLESS TRENDS SIGNIFICANTLY CHANGE. IF WE DO MANAGE TO GET ISOLATED CONVECTION GOING BY MIDDAY...BRIEF GUSTY WINDS MAY BE POSSIBLE DUE TO OUR SOUNDING PROFILE. OTHERWISE...EXPECT ANOTHER HOT DAY WITH ABOVE NORMAL TEMPS. AFTERNOON READINGS WILL BE HIGHEST OVER OUR SOUTHERN HALF...AS 850MB TEMPS IN THE MID 20S SURGE AHEAD OF THE FRONTAL BOUNDARY. HOWEVER...READINGS WILL BE TEMPERED BY MID LEVEL CLOUDINESS... ESPECIALLY OVER OUR NORTHERN COUNTIES. OVERALL...MAX TEMPS LOOK REASONABLE AND WILL NOT MAKE ANY ADJUSTMENTS AT THIS TIME. NO MAJOR UPDATES TO FORECAST REQUIRING A ZONE UPDATE...BUT WILL CONTINUE TO MONITOR TRENDS WITH MID LEVEL ECHOES. SCHULTZ PREV DISCUSSION... /ISSUED 617 AM CDT TUE MAY 20 2008/ AVIATION... /12Z UPDATE/ VFR CONDS TO PREVAIL ACROSS NORTH TEXAS THROUGH THE PERIOD. A WEAK FRONTAL BOUNDARY WILL SAG SOUTH THROUGH MIDDAY ALLOWING WINDS TO BECOME NORTHEAST BY 17Z. SOME SCT HIGH LEVEL CLOUDS WILL PASS BY THROUGH THE AFTERNOON. WILL MONITOR FOR A VERY ISOLATED SHOWER/TSTM ALONG FRONT THIS AFTN BUT OTHERWISE NO SIG AVIATION CONCERNS NEXT 24 HOURS. 91/DUNN PREV DISCUSSION... /ISSUED 525 AM CDT TUE MAY 20 2008/ 9Z RUC 850-1000MB THICKNESS FORECAST FOR THIS AFTERNOON ACROSS THE SW SUGGEST PREVIOUS HIGH TEMP FORECAST FOR TODAY WAS TOO COOL. HAVE BUMPED UP HIGHS 2-3 DEGREES IN THE SW ZONES. PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAY 20 2008/ A VERY WEAK COLD FRONT IS CURRENTLY BECOMING BETTER DEFINED ACROSS NW TEXAS ON THE BACK SIDE OF YESTERDAY/S REMNANT THERMAL CYCLONE NOW LOCATED SW OF WICHITA FALLS. SOUTHWARD FRONTAL MOVEMENT WILL BE AUGMENTED BY VEERING MID LEVEL FLOW IN RESPONSE TO A WEAK SHORTWAVE MOVING INTO THE LOWER MISSISSIPPI VALLEY. THE AXIS OF WARMEST LOW LEVEL THICKNESS VALUES WILL BE SHUNTED SOUTHWARD FROM THE NW ZONES INTO THE SW ZONES DURING THE DAY. THEREFORE...HIGHS WILL BE A FEW DEGREES COOLER OVER THE NORTHERN CWA...BUT A COUPLE DEGREES WARMER OVER THE SOUTH AHEAD OF THE FRONT. WACO SHOULD BREAK THEIR RECORD HIGH OF 95 LAST SET IN 1996. AN ISOLATED SHOWER OR STORM ALONG THE FRONT WILL BE POSSIBLE THIS AFTERNOON WHEN CIN MAY BECOME NEGLIGIBLE. THE LACK OF UPPER LEVEL LIFTING SUPPORT WARRANTS NO INCLUSION OF POPS IN THE WORDED FORECAST ATTM. THE FRONT WILL GRADUALLY MOVE THROUGH THE SOUTHERN CWA THIS EVENING BEFORE WASHING OUT. EAST TO NORTHEAST WINDS WILL BRING IN SLIGHTLY COOLER AIR TO THE REGION AND THEREFORE WEDNESDAY HIGH TEMPS WILL BE A LITTLE COOLER. A DEVELOPING LARGE AND DEEP UPPER LEVEL TROUGH OVER THE WESTERN CONUS WILL CAUSE SOUTHERLY WINDS TO INCREASE LATE WEDNESDAY AND INTO THE WEEKEND. WARMER OVERNIGHT LOW TEMPERATURES AND LATE NIGHT/MORNING STRATUS WILL BE THE RESULT. HIGH TEMPERATURES SHOULD REMAIN GENERALLY IN THE LOWER 90S WITH LOWS IN THE LOW TO MID 70S THROUGH EARLY NEXT WEEK. THE CHANCES OF RAIN LOOK RATHER LOW AS THE WESTERN SYSTEM FAILS TO ADVANCE EASTWARD. UPPER LEVEL RIDGING WILL BUILD IN ACROSS THE MIDWEST AND EVENTUALLY SLIDE SOUTHWEST TO ENCOMPASS THE REGION NEXT WEEK. ALTHOUGH MOISTURE/INSTABILITY WILL BE IN PLACE FOR CONVECTION...CIN WILL BE TOUGH TO OVERCOME IN THE ABSENCE OF UPPER LEVEL LIFT. THURSDAY AND FRIDAY MAY BE THE BEST SHOT AT ISOLATED AFTERNOON OR EVENING SHOWERS AND STORMS. WILL KEEP POPS AT 20 PERCENT THURSDAY THROUGH SATURDAY BEFORE HEIGHT RISES ASSOCIATED WITH THE BUILDING UPPER LEVEL HIGH PROMOTE SUBSIDENCE THEREAFTER. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 66 92 74 92 / 10 10 5 5 20 WACO, TX 95 67 92 73 92 / 5 5 10 10 20 PARIS, TX 89 59 87 68 89 / 10 10 5 5 20 DENTON, TX 93 62 91 73 92 / 10 5 5 5 20 MCKINNEY, TX 91 61 90 72 90 / 10 10 5 5 20 DALLAS, TX 93 67 92 74 92 / 10 10 5 5 20 TERRELL, TX 92 62 90 72 91 / 10 10 5 5 20 CORSICANA, TX 93 64 91 72 91 / 10 10 10 10 20 TEMPLE, TX 96 68 92 72 92 / 5 5 10 10 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ tx