AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EUREKA CA 330 AM PDT SUN APR 22 2007 .SYNOPSIS...AN UPPER LEVEL TROUGH WILL MOVE EAST ACROSS NORTHWEST CALIFORNIA TODAY THUS SHOWER ACTIVITY IS EXPECTED TO DECREASE THIS AFTERNOON. AN UPPER LEVEL RIDGE WILL BUILD OVER THE REGION TONIGHT WITH WARMER AND DRIER CONDITIONS EXPECTED FOR EARLY NEXT WEEK. && .DISCUSSION... 06Z NAM AND RUC MODEL DATA INDICATES RAPID DRYING LATER THIS AFTERNOON ALONG THE COAST THUS EXPECTING CURRENT SHOWER ACTIVITY TO TAPER OFF DRAMATICALLY LATE THIS MORNING OR EARLY THIS AFTERNOON. THE FRONTAL BOUNDARY THAT BROUGHT RAIN AND SNOW TO THE REGION YESTERDAY AND THIS MORNING MAY BE THE CABOOSE OF THIS WINTER/SPRING`S RAIN TRAIN...AS LONG TERM FORECAST MODELS DEPICT A MUCH WARMER AND DRIER PATTERN SHAPING AS WE HEAD INTO MAY. HIGH PRESSURE IS FORECAST TO BUILD OVER THE WEST BEGINNING ON MONDAY. A WEAK SHORTWAVE IS PROGGED TO MOVE ACROSS THE PACNW LATE TUESDAY AND WEDNESDAY...BUT IS EXPECTED TO ONLY BRING SOME LIGHT RAIN TO THE ORCA BORDER OR POSSIBLE DRIZZLE TO THE NORTH COAST. HIGH PRESSURE IS THEN FORECAST TO BUILD IN OVER THE WEST ONCE AGAIN LATE IN THE WORK WEEK WITH 583 DM 500 MB HEIGHTS FORECAST OVER THE EASTERN PACIFIC BY NEXT SATURDAY. && .AVIATION...SCT SHRA WILL DIMINISH IN COVERAGE ALONG THE COAST THIS AFTERNOON...ALTHOUGH INLAND AREAS WILL SEE SHOWERS CONTINUING THROUGH MUCH OF THE DAY. FLIGHT CONDITIONS WILL REMAIN PRIMARILY VFR ALTHOUGH OCCASIONAL MVFR CEILINGS/VISIBILITIES MAY OCCUR EARLY THIS MORNING AND IN HEAVIER SHOWERS. VFR CONDITIONS WITH CLEARING SKIES CAN BE ANTICIPATED TONIGHT. MAB && .MARINE...SEAS AND WINDS CONTINUE THEIR DOWNWARD TREND THIS MORNING...AND WILL CONTINUE TO DO SO FOR THE NEXT 12-24 HOURS. THUS THE GOING PACKAGE WILL REFLECT RELATIVELY SUBDUED CONDITIONS WITH NO ADVISORIES. LONGER PERIOD W SWELL WILL ARRIVE LATE TONIGHT/EARLY MONDAY WITH GRADUALLY BUILDING SEAS POSSIBLY WARRANTING SMALL CRAFT CRITERIA BY MONDAY. MAB NOTE...CDIP BUOY 46212 REMAINS OUT OF COMMISSION WITH NO ESTIMATED DATE OF REDEPLOYMENT. MAB && .EKA WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US AT WWW.WEATHER.GOV/EUREKA ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 958 AM EDT SUN APR 22 2007 .UPDATE...WATER VAPOR IMAGERY AND RUC GUIDANCE SHOW RIDGING OVER THE REGION WITH DRY AIR ALOFT. A STRONG SHORTWAVE WAS NOTED OVER THE CENTRAL PLAINS / UPPER MS VALLEY LIFTING NEWD. AT SFC...HIGH PRES HAS SHIFTED SE WITH A WEAKER PRES GRADIENT OVER THE S HALF OF ZONES SO WEAKER BOUNDARY LAYER WINDS ARE EXPECTED TODAY MAINLY OUT OF THE E AND SE. JAX SOUNDING SHOWS PWATS HAVE DROPPED SLIGHTLY SINCE YESTERDAY AND A STRONGER SUBSIDENCE INVERSION AND LITTLE LOWER AROUND 850 MB. STILL SUFFICIENT MOISTURE BELOW THE INVERSION TO GENERATE A HEALTHY CU FIELD LATER IN THE DAY. AS FAR AS THE WILD FIRE IN WARE COUNTY...SMOKE PLUME THIS MORNING IS ORIENTED SW-NE PER VIS IMAGERY PRESUMABLY DUE TO BACKED FLOW OVERNIGHT AS COASTAL TROUGH DEVELOPED. DEEPER ELY FLOW TODAY AS NOTED IN SOUNDING AND SLOW VEERING OF WINDS WILL ADVECT THE SMOKE TO THE W AND THEN NW. MINOR TWEAKS TO THE GRIDS FOR THIS AND WINDS. OTHERWISE...NO MAJOR CHANGES TO THE FORECAST WITH HIGHS FROM MID 70S COAST TO LOWER 80S INLAND. && .AVIATION...NO SIGNIFICANT ISSUES WITH BENIGN WX PATTERN AND SCT CU MAINLY AT NE FL TAF SITES. BRIEF CIGS POSSIBLE DUE SHOULD BE VFR ALL DAY. && .MARINE...BASED ON BUOY REPORTS AND GUIDANCE WILL LET THE ADVISORY EXPIRE AT OR BEFORE 11 AM. SEAS FROM 41012 ARE AROUND 5 FT AND 3-4 FT IN OUR SE GA WATERS. MAY BE ABLE TO TAKE DOWN SCEC IN NEAR SHORE WATERS AND GO WITH 3-5 FT. && .FIRE WEATHER...A CHALLENGING FIRE WX FORECAST AGAIN WITH MARGINAL RED FLAG FOR FL ZONES. BASED ON RECOMPUTED RH VALUES...RED FLAG WARNING IN OUR FL ZONES COULD BE EXPANDED BUT AM HESITANT TO DO THIS BASED ON YESTERDAY`S EVENT WHERE DEWPOINTS DID NOT DROP AS PREVIOUSLY THOUGHT. MORE SIGNIFICANT DROP IN DEWPOINTS IS LIKELY OVER SE GA. BASED ON COMBINATION OF LOW LEVEL MIXING AND MOS GUIDANCE SEEMS VERY POSSIBLE TO GET 4 HOURS LOW RH DURATION IN A FEW SE GA COUNTIES THIS AFTERNOON...SIMILAR TO SATURDAY. THEREFORE WILL LIKELY ISSUE A RED FLAG WARNING BEFORE NOON. && .PRELIMINARY POINT TEMPS/POPS... AMG 81 49 83 52 / 0 0 0 10 SSI 73 60 75 61 / 0 0 0 0 JAX 77 52 81 54 / 0 0 0 10 SGJ 75 57 78 59 / 0 0 0 0 GNV 81 50 84 54 / 0 0 0 10 OCF 82 50 83 53 / 0 0 0 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...RED FLAG WARNING FROM 1 PM TO 6 PM EDT THIS AFTERNOON FOR COLUMBIA-GILCHRIST-HAMILTON-SUWANNEE. FIRE WEATHER WATCH MONDAY AFTERNOON FOR ALACHUA-BAKER-BRADFORD- COLUMBIA-GILCHRIST-HAMILTON-MARION-SUWANNEE-UNION. GA...RED FLAG WARNING FROM 1 PM TO 6 PM EDT THIS AFTERNOON FOR APPLING-BACON-COFFEE-JEFF DAVIS. AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM EDT THIS MORNING FOR FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE. && $$ SHASHY/MCALLISTER fl AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER TOPEKA KS 1008 AM CDT SUN APR 22 2007 .DISCUSSION... CHANGED THE TIMING OF THE WIND ADVISORY FOR THIS MORNING. CLOUDS HAVE CLEARED ACROSS THE WESTERN CWA AT MID MORNING. WINDS HAVE INCREASED RAPIDLY IN THIS AREA AND HAVE ALSO EXPANDED THE WIND ADVISORY WEST TO ABILENE AND NORTHEAST TO HOLTON FOR TODAY. THE UPPER LOW WAS NEAR KHLC WITH DRY SLOT WORKING ACROSS CENTRAL KANSAS. THE SURFACE LOW WAS NEAR HAYS THIS MORNING AND NEW RUC MOVES THE LOW INTO SOUTH CENTRAL NEBRASKA BY EARLY AFTERNOON. DRY LINE WILL BE PUSHING THROUGH THE CWA THROUGH THE AFTERNOON HOURS WITH BEST CONVECTIVE THREAT BETWEEN 18Z AND 22Z AS UPPER LOW MOVE NORTHEAST AND ERODES MID LEVEL CAP. MAIN CONCERN WILL BE ALONG THE NEBRASKA BORDER WHERE BEST LOW LEVEL SHEAR WILL BE THIS AFTERNOON. WE WILL BE LAUNCHING AN 18Z RAOB BALLOON TODAY. && .PREVIOUS DISCUSSION... THE 09Z WATER VAPOR SATELLITE IMAGERY SHOWED AN UPPER LEVEL LOW CENTERED OVER SOUTHEAST CO. A DRY INTRUSION AT 850-600MB WAS PUNCHING NORTHEAST INTO SOUTHWEST KS. A BROAD AREA OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUED TO WEAKEN AS THE SLOWLY ADVANCE NORTHEAST ACROSS CENTRAL KS. BOTH THE NAM AND THE GFS LIFT THE UPPER LOW NORTHEAST INTO EASTERN NE AND WESTERN IA BY EARLY THIS EVENING. THE BAND OF SHOWERS AND ISOLATED THUNDERSTORMS MAY HOLD TOGETHER AS THEY MOVE NORTHEAST ACROSS THE WESTERN AND CENTRAL COUNTIES THIS AFTERNOON. WE MAY SEE THE CLOUD COVER BREAK UP A BIT LATE THIS MORNING AND EARLY THIS AFTERNOON AS THE MID-LEVEL DRY SLOT MOVES NORTHEAST ACROSS EASTERN KS THIS AFTERNOON. IF WE GET SOME INSOLATION THIS AFTERNOON...SURFACE HEATING WILL CAUSE THE INSTABILITY TO INCREASE WITH MLCAPE APPROACHING 1000J/KG ACROSS THE CENTRAL AND EASTERN COUNTIES OF THE CWA. NAM FORECAST SOUNDINGS SHOW NO CAP THUS CONVERGENCE ALONG THE PACIFIC COLD FRONT...WHICH WILL BE MOVING EAST ACROSS THE CENTRAL AND EASTERN COUNTIES OF THE CWA THIS AFTERNOON WILL CAUSE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP. INSTABILITY AND VERTICAL WINDSHEAR PROFILES WILL BE SUFFICIENT FOR THESE STORMS TO ROTATE. THE PRIMARY THREAT FROM ANY SUPERCELL THUNDERSTORMS WILL BE DAMAGING OUTFLOW WINDS AND LARGE HAIL. THE LOW-LEVEL WINDS FIELDS ARE FORECASTED TO REMAIN SOUTH TO SOUTHEASTERLY ACROSS NORTHEAST KS THIS AFTERNOON. THE ENHANCED LOW-LEVEL VERTICAL WINDSHEAR MAY CAUSE SUPERCELL THUNDERSTORMS THAT DEVELOP ACROSS THE NORTHEAST COUNTIES TO PRODUCE ISOLATED TORNADOES THIS AFTERNOON. AGAIN THE SEVERITY OF THESE STORMS WILL BE DEPENDENT ON THE AMOUNT OF SURFACE HEATING AHEAD OF THE PACIFIC COLD FRONT. IF WE HOLD ON TO THE CLOUD COVER THE INSTABILITY WILL BE REDUCED WHICH COULD KEEP MANY STORMS BELOW SEVERE LEVELS. HIGH TEMPERATES SHOULD WARM INTO THE LOWER TO MID 70S...ESPECIALLY IF WE SEE AFTERNOON SUNSHINE. 850MB WINDS ACROSS THE EASTERN COUNTIES ARE FORECASTED TO BE 40 TO 45 KTS FROM THE SOUTH AND SOUTHWEST. IF SKIES CLEAR THE BOUNDARY LAYER WILL MIX TO 850MB AND THE HIGHER MOMENTUM AIR PARCEL WILL MIX DOWN TOWARDS THE SURFACE. THIS WILL CAUSE SOUTHERLY SURFACE WINDS ACROSS EAST CENTRAL AND NORTHEAST KANSAS TO INCREASE AT OR ABOVE 30 MPH WITH GUSTS AS HIGH AS 45 MPH THIS AFTERNOON. THEREFORE I HAVE ISSUED A WIND ADVISORY FOR AREAS ALONG AND SOUTH OF A HERINGTON TO ALMA TO TOPEKA TO OSKALOOSA LINE. THIS EVENING THE PACIFIC COLD FRONT WILL MOVE EAST OF THE CWA...BRINGING AN END TO ANY THUNDERSTORM CHANCES. I KEPT 20 POPS ACROSS THE EXTREME EASTERN COUNTIES UNTIL 02Z. SKIES SHOULD CLEAR THROUGH THE NIGHT AS THE SURFACE WINDS VEER AROUND TO THE WEST AND DECREASE IN SPEED BELOW 15 MPH AFTER MIDNIGHT. LOWS WILL ONLY DROP INTO THE 50S. WE`LL BE BETWEEN UPPER LEVEL TROUGHS ON MONDAY AS SLIGHTLY DRIER AIR ADVECTS SOUTHEAST ACROSS THE CWA. HIGHS WILL BE IN THE LOWER TO MID 70S WITH MOSTLY SUNNY SKIES. THE NEXT 5H TROUGH LOOKS VERY INTENSE OFF THE OR AND CA COAST. THIS 5H TROUGH WILL DIG SOUTHEAST ACROSS THE DESERT SOUTHWEST ON MONDAY. A LEE SURFACE LOW WILL DEEPEN MONDAY NIGHT IN RESPONSE TO THE STRONGER SOUTHWEST FLOW ALOFT OVER THE ROCKY MOUNTAINS. DEEPER GULF MOISTURE WILL BE TRANSPORTED NORTH ACROSS WESTERN OK INTO WESTERN KS. WAA/ISENTROPIC LIFT ON THE EAST SIDE OF THE DEVELOPING MOIST AXIS WILL CAUSE SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS CENTRAL KS DURING THE EVENING HOURS OF MONDAY. THESE THUNDERSTORMS WILL MOVE NORTHEAST ACROSS THE CWA LATE MONDAY NIGHT. ON TUESDAY THE INTENSE 5H TROUGH WILL LIFT NORTHEAST INTO THE SOUTHERN HIGH PLAINS. THERE MAY BE A SEVERE THUNDERSTORM OUTBREAK TUESDAY AFTERNOON ACROSS SOUTHWEST AND CENTRAL KS...SOUTHWARD INTO NORTH TEXAS. DEEP GULF MOISTURE WILL BE IN PLACE WITH INCREASING VERTICAL WINDSHEAR IN THE WARM SECTOR AHEAD OF THE PACIFIC FRONT/DRYLINE. SUPERCELL THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON HOURS ALONG THE DRYLINE AND MOVE NORTHEAST. THE SCATTERED DISCRETE SUPERCELL THUNDERSTORMS WILL CONGEAL INTO AN MCS/SQUALL LINE THROUGH THE EVENING HOURS AND MOVE NORTHEAST ACROSS THE CWA. THERE IS A CHANCE THAT THESE STORMS MAY BE SEVERE WHEN THEY MOVE ACROSS THE CWA TUESDAY NIGHT. THE MAIN THREAT WILL BE DAMAGING STRAIGHT LINE WINDS AND LARGE HAIL. ELEVATED SEVERE THUNDERSTORMS MAY DEVELOP NORTH OF THE WARM FRONT DURING THE DAY ON TUESDAY WITH LARGE HAIL BEING THE PRIMARY THREAT. THE UPPER LOW WILL SLOWLY MOVE EAST ACROSS KANSAS WEDNESDAY AND WEDNESDAY NIGHT...KEEPING RAIN AND THUNDERSTORMS CHANCES ACROSS THE CWA THROUGH EARLY THURSDAY MORNING. HIGHS ON WEDNESDAY WILL BE COOLER WITH RAIN AND THUNDERSTORMS THROUGH THE DAY...ALSO COLDER AIR WILL BEGIN TO ADVECT SOUTHEAST ACROSS THE CWA BEHIND THE PACIFIC COLD FRONT. HIGH TEMPERATURES MAY BE WARMEST IN THE MORNING WITH TEMPERATURES IN THE LOWER 60S....WITH STEADY OR SLOWLY FALLING TEMPERATURES THROUGH THE DAY. SKIES SHOULD CLEAR FROM WEST TO EAST ACROSS THE CWA ON THURSDAY...THOUGH LOW-LEVEL CAA WILL KEEP HIGH TEMPERATURES IN THE MID TO UPPER 60S. FRIDAY LOOKS WARMER AS A 5H RIDGE MOVES EAST ACROSS THE PLAINS. HIGHS ON FRIDAY WILL WARM INTO THE LOWER TO MID 70S THE EXTENDED RANGE MODELS SHOW ANOTHER 5H TROUGH MOVING EAST TOWARDS THE CENTRAL AND SOUTHERN PLAINS ON SATURDAY PROVIDING A CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE CWA. THE CURRENT EXTENDED RANGE FORECAST GRIDS LOOKED GOOD AND NO CHANGES WERE MADE. && .TOP WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY IN EFFECT THROUGH 700 PM CDT FOR AREAS ALONG AND SOUTH OF AN ABILENE TO MANHATTAN TO HOLTON LINE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 639 AM CDT SUN APR 22 2007 .AVIATION... VFR CONDITIONS CAN BE EXPECTED FOR THE NEXT 24 HOURS AT THE TERMINALS WITH CIGS GENERALLY IN THE 080 TO 100 RANGE. KHYS MAY SEE A PERIOD OF BORDERLINE MVFR CIGS DURING THE DAY TODAY, ALONG WITH A FEW SHOWERS AS THE UPPER LOW LIFTS OUT. THE MAIN STORY WILL BE THE WIND AS AN AREA OF LOW PRESSURE OVER SOUTHWEST KANSAS THIS MORNING MOVES EAST NORTHEAST ACROSS THE STATE TODAY. WINDS WILL VEER AROUND FROM SOUTHWEST TO NORTHWEST BY AFTERNOON AND WILL BE QUITE GUSTY IN THE 30 TO 40 KT RANGE. THE WINDS WILL BECOME LIGHT AND VARIABLE BY EVENING. && .PREV DISCUSSION... /ISSUED 312 AM CDT SUN APR 22 2007/ DISCUSSION... DAYS 1-2... FORECAST CHALLENGE WILL BE WHEN THE THUNDERSTORMS END ACROSS SOUTHWEST KANSAS THIS MORNING AND THEN THE CHANCE FOR THUNDERSTORMS LATE MONDAY AFTERNOON AND NIGHT. THE 00Z UPPER AIR ANALYSIS SHOWED A SIGNIFICANT UPPER LEVEL SHORTWAVE TROUGH LOCATED OVER THE CENTRAL AND SOUTHERN ROCKIES. THIS WAVE WAS LIFTING OUT ACROSS THE CENTRAL HIGH PLAINS EARLY THIS MORNING. THE MCS THAT IS LEFT OVER FROM THE SEVERE CONVECTION EARLIER IN THE EVENING HAD MOVED THROUGH MOST OF THE CWA. ANOTHER AREA OF THUNDERSTORMS HAD DEVELOPED OVER SOUTHEAST COLORADO UNDER THE UPPER SYSTEM. THIS AREA OF STORMS WAS PIVOTING OUT INTO WEST CENTRAL KANSAS. THE AREA OF THUNDERSTORMS WILL BE LIFTING OUT TO THE NORTHEAST THIS MORNING BUT THERE SHOULD BE SOME SCATTERED SHOWERS AND A FEW STORMS OVER THE NORTHWEST SECTIONS OF THE CWA FOR A TIME...SIMILAR TO WHAT IS FORECAST BY THE RUC. HAVE REORIENTED POPS IN THAT AREA BETWEEN 12 AND 18Z. AFTER THAT TIME, MODEL SOUNDINGS SHOW THE LOWER LEVELS MIXING OUT TO AROUND 700 MB WITH A SMALL POSITIVE AREA. COULD BE SOME SHOWERS REDEVELOPING THIS AFTERNOON AS A COLD POOL ALOFT MOVES OUT. DOUBT IF THERE WILL BE ANY SIGNIFICANT PRECIP WITH THESE SHOWERS SO THE SILENT POPS IN PLACE OUGHT TO HANDLE IT. ON MONDAY, THE NEXT SYSTEM WHICH IS NOW APPROACHING THE COAST OF NORTHERN CALIFORNIA WILL MOVE INTO THE SOUTHWESTERN CONUS WITH INCREASING SOUTHWESTERLY FLOW ALOFT OVER THE CENTRAL PLAINS. THE MODELS SHOW A WARM FRONT LOCATED ALONG OR JUST SOUTH OF THE KANSAS BORDER WITH A DRYLINE EXTENDING SOUTH INTO THE EASTERN TEXAS PANHANDLE MONDAY AFTERNOON. WHILE THERE IS SOME DISAGREEMENT ON EXACTLY WHERE THE SURFACE LOW WILL BE, THINK THAT THE BEST CHANCES FOR THUNDERSTORMS WILL BE OVER THE EASTERN AND NORTHERN PARTS OF THE CWA WHERE THE BETTER LOW LEVEL MOISTURE WILL BE RETURNING. HAVE REORIENTED POPS LATE MONDAY AFTERNOON AND NIGHT TO REFLECT THIS. THE GOING TEMPERATURE FORECAST LOOKED PRETTY GOOD WITH ONLY A FEW MINOR ADJUSTMENTS TO IT. DAYS 3-7... ACTIVE SPRING PATTERN WILL BE CONTINUING THROUGH THE EARLY PART OF THE UPCOMING WORK WEEK. THE NEXT IN A SERIES OF SYSTEMS TO AFFECT THE PLAINS WILL ARRIVE ON TUESDAY. BASED ON LATEST MODEL GUIDANCE FROM THE UKMET/GFS, THE SURFACE WARM FRONT SHOULD LIFT NORTH ACROSS THE CWA MONDAY NIGHT AND WILL RESIDE OVER NORTHERN KS ON TUESDAY. THE PACIFIC FRONT/DRYLINE WILL PUSH RAPIDLY EAST ACROSS WESTERN KS DURING THE DAY WITH A SMALL CHANCE OF STORMS AHEAD OF IT OVER MAINLY MY EASTERN TIER OF COUNTIES. THE BETTER RISK FOR SEVERE STORMS WILL MOST LIKELY BE EAST OF MY CWA BY TUESDAY AFTERNOON. THEN THE WRAP AROUND PRECIP ON THE COOL SIDE OF THE SYSTEM ENTERS THE WESTERN COUNTIES DURING THE AFTERNOON AND SWEEPS EAST ACROSS THE REMAINDER OF THE AREA TUESDAY NIGHT. POPS WILL BE GRADUALLY COMING TO AN END ON WEDNESDAY AS THE SYSTEM PULLS AWAY FROM WESTERN KS. DID NOT PULL POPS COMPLETELY AS THE UKMET STILL HAS THE UPPER LOW OVER NORTH CENTRAL KS ON WEDNESDAY. THE POP/WX GRIDS WERE TWEAKED TO FOLLOW ALONG WITH THE FORECAST REASONING. THE NEXT SYSTEM WILL MOVE INTO THE PLAINS TOWARD THE END OF THE WEEK BUT THE LATEST FORECASTS FROM THE UKMET/ECMWF/GFS ALL KEEP THE SYSTEM PROGRESSIVE AND NORTH OF KANSAS. OTHER THAN A FEW SHOWERS ALONG THE PACIFIC FRONT, THIS DOES NOT LOOK LIKE A BIG RAIN PRODUCER FOR MY CWA. THE SYSTEM WILL BE EAST OF US ON FRIDAY AND ALL THE NUMERICAL MODELS ARE IN AGREEMENT WITH THIS. WILL THEREFORE BACK OFF TO SILENT POPS DURING THIS PERIOD. ALSO MADE SOME TWEAKS TO THE TEMPERATURES ON TUESDAY AND WEDNESDAY. I TRENDED COOLER IN THE WEST ON TUESDAY AS THE COOL AIR ON THE BACKSIDE OF THE SYSTEM MOVES IN. ON WEDNESDAY, 850MB TEMPS SUPPORT HIGHS ONLY IN THE 50S OVER THE EAST AND 60S IN THE WEST WITH COOL SURFACE HIGH PRESSURE IN PLACE. HIGHS WERE THEREFORE LOWERED TO ACCOUNT FOR THIS. AVIATION... DISCUSSION WILL BE ISSUED FOLLOWING THE 12Z TAF ISSUANCE. && .PRELIMINARY POINT TEMPS/POPS... DDC 72 47 74 55 / 10 0 30 50 GCK 72 45 74 54 / 10 0 30 40 EHA 74 44 77 54 / 10 0 20 30 LBL 74 46 76 56 / 0 0 30 40 HYS 69 45 72 55 / 30 0 30 50 P28 74 51 76 60 / 10 0 40 50 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ FN02/27/27 ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 312 AM CDT SUN APR 22 2007 .DISCUSSION... DAYS 1-2... FORECAST CHALLENGE WILL BE WHEN THE THUNDERSTORMS END ACROSS SOUTHWEST KANSAS THIS MORNING AND THEN THE CHANCE FOR THUNDERSTORMS LATE MONDAY AFTERNOON AND NIGHT. THE 00Z UPPER AIR ANALYSIS SHOWED A SIGNIFICANT UPPER LEVEL SHORTWAVE TROUGH LOCATED OVER THE CENTRAL AND SOUTHERN ROCKIES. THIS WAVE WAS LIFTING OUT ACROSS THE CENTRAL HIGH PLAINS EARLY THIS MORNING. THE MCS THAT IS LEFT OVER FROM THE SEVERE CONVECTION EARLIER IN THE EVENING HAD MOVED THROUGH MOST OF THE CWA. ANOTHER AREA OF THUNDERSTORMS HAD DEVELOPED OVER SOUTHEAST COLORADO UNDER THE UPPER SYSTEM. THIS AREA OF STORMS WAS PIVOTING OUT INTO WEST CENTRAL KANSAS. THE AREA OF THUNDERSTORMS WILL BE LIFTING OUT TO THE NORTHEAST THIS MORNING BUT THERE SHOULD BE SOME SCATTERED SHOWERS AND A FEW STORMS OVER THE NORTHWEST SECTIONS OF THE CWA FOR A TIME...SIMILAR TO WHAT IS FORECAST BY THE RUC. HAVE REORIENTED POPS IN THAT AREA BETWEEN 12 AND 18Z. AFTER THAT TIME, MODEL SOUNDINGS SHOW THE LOWER LEVELS MIXING OUT TO AROUND 700 MB WITH A SMALL POSITIVE AREA. COULD BE SOME SHOWERS REDEVELOPING THIS AFTERNOON AS A COLD POOL ALOFT MOVES OUT. DOUBT IF THERE WILL BE ANY SIGNIFICANT PRECIP WITH THESE SHOWERS SO THE SILENT POPS IN PLACE OUGHT TO HANDLE IT. ON MONDAY, THE NEXT SYSTEM WHICH IS NOW APPROACHING THE COAST OF NORTHERN CALIFORNIA WILL MOVE INTO THE SOUTHWESTERN CONUS WITH INCREASING SOUTHWESTERLY FLOW ALOFT OVER THE CENTRAL PLAINS. THE MODELS SHOW A WARM FRONT LOCATED ALONG OR JUST SOUTH OF THE KANSAS BORDER WITH A DRYLINE EXTENDING SOUTH INTO THE EASTERN TEXAS PANHANDLE MONDAY AFTERNOON. WHILE THERE IS SOME DISAGREEMENT ON EXACTLY WHERE THE SURFACE LOW WILL BE, THINK THAT THE BEST CHANCES FOR THUNDERSTORMS WILL BE OVER THE EASTERN AND NORTHERN PARTS OF THE CWA WHERE THE BETTER LOW LEVEL MOISTURE WILL BE RETURNING. HAVE REORIENTED POPS LATE MONDAY AFTERNOON AND NIGHT TO REFLECT THIS. THE GOING TEMPERATURE FORECAST LOOKED PRETTY GOOD WITH ONLY A FEW MINOR ADJUSTMENTS TO IT. DAYS 3-7... ACTIVE SPRING PATTERN WILL BE CONTINUING THROUGH THE EARLY PART OF THE UPCOMING WORK WEEK. THE NEXT IN A SERIES OF SYSTEMS TO AFFECT THE PLAINS WILL ARRIVE ON TUESDAY. BASED ON LATEST MODEL GUIDANCE FROM THE UKMET/GFS, THE SURFACE WARM FRONT SHOULD LIFT NORTH ACROSS THE CWA MONDAY NIGHT AND WILL RESIDE OVER NORTHERN KS ON TUESDAY. THE PACIFIC FRONT/DRYLINE WILL PUSH RAPIDLY EAST ACROSS WESTERN KS DURING THE DAY WITH A SMALL CHANCE OF STORMS AHEAD OF IT OVER MAINLY MY EASTERN TIER OF COUNTIES. THE BETTER RISK FOR SEVERE STORMS WILL MOST LIKELY BE EAST OF MY CWA BY TUESDAY AFTERNOON. THEN THE WRAP AROUND PRECIP ON THE COOL SIDE OF THE SYSTEM ENTERS THE WESTERN COUNTIES DURING THE AFTERNOON AND SWEEPS EAST ACROSS THE REMAINDER OF THE AREA TUESDAY NIGHT. POPS WILL BE GRADUALLY COMING TO AN END ON WEDNESDAY AS THE SYSTEM PULLS AWAY FROM WESTERN KS. DID NOT PULL POPS COMPLETELY AS THE UKMET STILL HAS THE UPPER LOW OVER NORTH CENTRAL KS ON WEDNESDAY. THE POP/WX GRIDS WERE TWEAKED TO FOLLOW ALONG WITH THE FORECAST REASONING. THE NEXT SYSTEM WILL MOVE INTO THE PLAINS TOWARD THE END OF THE WEEK BUT THE LATEST FORECASTS FROM THE UKMET/ECMWF/GFS ALL KEEP THE SYSTEM PROGRESSIVE AND NORTH OF KANSAS. OTHER THAN A FEW SHOWERS ALONG THE PACIFIC FRONT, THIS DOES NOT LOOK LIKE A BIG RAIN PRODUCER FOR MY CWA. THE SYSTEM WILL BE EAST OF US ON FRIDAY AND ALL THE NUMERICAL MODELS ARE IN AGREEMENT WITH THIS. WILL THEREFORE BACK OFF TO SILENT POPS DURING THIS PERIOD. ALSO MADE SOME TWEAKS TO THE TEMPERATURES ON TUESDAY AND WEDNESDAY. I TRENDED COOLER IN THE WEST ON TUESDAY AS THE COOL AIR ON THE BACKSIDE OF THE SYSTEM MOVES IN. ON WEDNESDAY, 850MB TEMPS SUPPORT HIGHS ONLY IN THE 50S OVER THE EAST AND 60S IN THE WEST WITH COOL SURFACE HIGH PRESSURE IN PLACE. HIGHS WERE THEREFORE LOWERED TO ACCOUNT FOR THIS. && .AVIATION... DISCUSSION WILL BE ISSUED FOLLOWING THE 12Z TAF ISSUANCE. .PRELIMINARY POINT TEMPS/POPS... DDC 72 47 74 55 / 10 0 30 50 GCK 72 45 74 54 / 10 0 30 40 EHA 74 44 77 54 / 10 0 20 30 LBL 74 46 76 56 / 0 0 30 40 HYS 69 45 72 55 / 30 0 30 50 P28 74 51 76 60 / 10 0 40 50 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ FN02/27 ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 1059 AM CDT SUN APR 22 2007 .DISCUSSION... NARROW BAND OF SHOWERS WITH ISOLATED THUNDERSTORMS CONTINUES ALONG SFC-850MB THETA-E AXIS...AND ALONG THE TAIL END OF THE SHORTWAVE TROUGH EXTENDING FROM W AR NWD INTO MO TO THE PARENT CLOSED LOW NOW ENTERING E NE. BOTH THE NEW RUC AND 12Z NAM INITILIZED TOO FAR W WITH THESE FEATURES...THUS HAVE SPED UP POPS FOR SW AR AND REMOVED AFTERNOON MENTION. DID UP POPS TO LOW CHANCE FOR THE FAR N SW AR COUNTIES PER RADAR TRENDS...AND ASSUMPTION THAT TROUGH AXIS WILL GRADUALLY LIFT MORE NEWD THIS AFTERNOON WITH THE PARENT LOW. PLENTIFUL SFC-850MB MOISTURE NOTED ALONG THE S EXTENT OF THE THETA-E RIDGE OVER E TX/W LA...WILL BE SLOW TO LIFT WITH ADDITIONAL GULF INFLOW...BUT MAY GRADUALLY MIX OUT BY MID/LATE AFTERNOON. ALREADY NEARING LAKE WIND ADV. CRITERIA ACROSS WESTERN E TX...BUT ADDITIONAL CLOUD COVER DEVELOPING MAY LIMIT MIXING/POTENTIAL TO ONLY A SMALL AREA THROUGH THE AFTERNOON. OTHERWISE...ONLY MADE MINOR DOWNWARD TWEAKS IN FORECAST MAX TEMPS BASED ON 15Z OBS...AND INCREASED CLOUD COVER. UPDATE ALREADY OUT. 15 && .AVIATION... MIXTURE OF MVFR AND VFR CIGS LATE THIS MORNING WILL GIVE WAY TO SCT TO BKN CLOUDS AROUND 4 KFT BY 18Z. VSBYS...RESTRICTED BY HAZE IN THE 3 TO 5 MILE RANGE IN MANY AREAS WILL ALSO IMPROVE TO P6SM AS BRISK SOUTHERLY WINDS AROUND 15 KTS MIX AIR FROM ALOFT. ISOLATED TSTMS WILL BE CONFINED TO EXTREME NORTHERN AREAS IN SOUTHEAST OKLAHOMA AND SOUTHWEST ARKANSAS. ONLY TERMINALS TO HAVE ANY SHOWER OR TSTM ACTIVITY WITIN 25 MILES AFT 18Z TAF ISSUE WOULD BE TXK AND ELD... AND MAYBE SHV...BUT CHANCE TOO LOW TO MENTION. CONDITIONS SHOULD REMAIN VFR THROUGHOUT THE EVENING HOURS...BUT LOOK FOR A REPEAT OF MVFR CIGS AND VSBYS BEGINNING AROUND 23/07Z AND OCCASIONAL BRIEF IFR CIGS AND VSBYS BETWEEN 23/10Z AND 23/14Z. TERMINAL MOST LIKELY TO EXPERIENCE IFR...CIGS AND VSBYS...WILL BE LFK. SHV MAY REPEAT IFR CIGS. CONDS IMPROVING TO VFR AFT 23/16Z. SOUTHERLY WINDS THIS AFTERNOON IN THE 12 TO 16 KT SUSTAINED WITH GUSTS 20 TO 25 KTS WILL DIMINISH TO 10 KTS OR LESS BY 23/01Z. WINDS NOT AS STRONG MONDAY...WITH SOUTHERLY 10 TO 15 KTS EXPECTED. /14/ && .PRELIMINARY POINT TEMPS/POPS... SHV 82 63 84 65 / 10 10 10 20 MLU 81 61 82 64 / 0 0 10 10 DEQ 78 59 82 63 / 20 20 10 20 TXK 79 64 81 66 / 20 20 10 20 ELD 81 61 82 63 / 10 10 10 20 TYR 80 64 81 66 / 10 10 10 20 GGG 81 63 82 66 / 10 10 10 20 LFK 81 64 83 67 / 0 10 10 20 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 15/14 la AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE WAKEFIELD VA 1024 AM EDT SUN APR 22 2007 .SHORT TERM /REST OF TODAY/... FEW UPDATES TO FORECAST THIS MORNING. WITH SURFACE HI PRES IN PLACE THE FORECAST AREA WILL HAVE ANOTHER QUIET WARM SPRING DAY TODAY. MINOR TWEAKS TO TEMPS ACROSS THE AREA. NOT SO SURE DW PTS WILL DECREASE DRAMATICALLY TODAY AS YESTERDAY IN SW FLOW. KEPT DW PTS ON LOW END OF GUIDANCE THRU THIS EVENING. ZFPAKQ ALREADY OUT. && .PREV DISCUSSION... /ISSUED 329 AM EDT SUN APR 22 2007/ SHORT TERM /TODAY THROUGH MONDAY NIGHT/... SHORT TERM CHALLENGES WERE PRIMARILY IN REFINING TEMPERATURES. BROAD AREA OF HIGH PRESSURE CONTINUES TO DOMINATE OVER THE EASTERN CONUS...WITH CLOSEST RADAR ECHOES OF NOTE OVER THE PLAINS STATES. ANOTHER WARM/DRY AFTN...AS HIGH PRESSURE CONTINUES TO SLOWLY DRIFT SE...MOVING OFF CAROLINA COAST THIS AFTN. RAPIDLY RISING HEIGHTS THIS AFTN...AND WARM/DRY RETURN FLOW BY AFTERNOON...SUGGESTS L/M 80S EASILY ATTAINABLE FOR MOST OF CWA...TO AROUND 80 AT IMMEDIATE COAST AND OVER EASTERN SHORE. EXPECTING SEA BREEZE TO AGAIN PLAY A ROLE OVER COASTAL PLAIN THIS AFTN. ONCE AGAIN AGAINST IMMEDIATE COASTLINE WITH VRY LGT SYNOPTIC WNDS THIS AFTN. HV MADE SOME MINOR ADJUSTMENTS OVER THESE LOCATIONS TO REFLECT SLIGHTLY COOLER TEMPS BY MID TO LT AFTERNOON IVOF ORF/CPK/NCZ102. USED MAV/MET BLEND FOR TEMPERATURES THIS AFTN...AND TRENDED TOWARDS COOLER MAV GUIDANCE FOR TONIGHT WITH LTL/ANY DISCERNIBLE CLOUD COVER ALLOWING FOR ANOTHER GOOD RADIATING NGT. ANOTHER WARM/DRY DAY ON TAP FOR MONDAY...WITH M/U 80S LOOKING POSSIBLE FOR PIEDMONT AND CENTRAL VA (L/M 80S AT COAST) WITH ROBUST RETURN FLOW BY MONDAY AFTN. WENT CLOSER TO WARMER MAV GUIDANCE FOR HIGHS ON MONDAY. CLOUDS SLOWLY INCREASE BY MONDAY NGT/ERY TUESDAY AHEAD OF NEXT WEATHER MAKER. LONG TERM /TUESDAY THROUGH SATURDAY/... BIGGEST CHALLENGE IN EXTENDED WAS IN TIMING AND DETERMINING PCPN CHANCES FOR MID TO LATE WEEK. STILL GOOD MODEL AGREEMENT THAT FIRST FRONTAL SYSTEM WL REMAIN NORTH OF THE AREA....GENERALLY REMAINING ORIENTED FROM SOUTHERN NEW ENGLAND SOUTH INTO NORTHERN VA AND EXTENDING INTO THE OHIO VLY. 00Z/APR22 GFS DOES BRING BACKDOOR FRONTAL BNDRY A BIT FURTHER SOUTH THAN NAM. HOWEVER DO NOT SEE MUCH IN THE WAY OF FORCING THAT WOULD SUPPORT THIS SOLN ATTM. FOR NOW...WL PUSH FRONT AS FAR SOUTH AS FAR NORTHERN COUNTIES...RESULTING IN MOST OF THE AREA REMAINING DRY...AND REMAINING WITHIN WARM SECTOR. DUE TO THE PROXIMITY OF THE FRONT...WL INCREASE CLD COVER OVER THE NORTH AND KEEP SLIGHT CHANCE POPS FOR RIC-WAL AND NORTH FOR TUES NGT/WED. FUTURE SHIFTS WL BE ABLE TO ADJUST THIS AS NECESSARY. EITHER WAY...IT SHOULD BE NOTED THAT MEAGER AVAILABLE PCPN (PW VALUES REMAIN UNDERWHELMING) AND LACK OF ANY VIABLE CONVERGENCE CONTINUE TO BOLSTER BELIEF THAT ANY PCPN THAT DOES THREATEN THE AREA WL BE LGT AND VERY SMALL IN AREAL COVERAGE. FRONT DRIFTS BACK NORTH WEDNESDAY. AGREE WITH GOING FORECAST THAT A SIZABLE TEMPERATURE GRADIENT COULD EXIST BETWEEN NORTHERN AND SOUTHERN CWA...WITH LINGERING CLOUDINESS AND SCTD SHRAS HOLDING TEMPS BACK A BIT OVER NORTHERN SECTIONS. HOWEVER...KEPT TEMPS A LITTLE WARMER THAN MEX VALUES GIVEN LACK OF MODEL CONTINUITY OF LATE. NEXT...AND MORE LKLY PCPN THREAT COMES WITH A STRONGER FRONTAL PASSAGE THU NGT/FRI. LOW PRESSURE WL DEVELOP OVER THE MO VLY BY THU...TRACKING EASTWARD ALONG THE FRONTAL BOUNDARY. MODEL GUIDANCE CONTINUES TO KEEP BEST SLUG OF MOISTURE NORTH OF THE AREA. NONETHELESS...CONTINUING THE GOING CHC (30) POP FOR SHRAS/TSTMS AS H5 TROF PUSHES THROUGH ERY FRIDAY INTO FRI AFTN LKS GOOD. DRIER WX MOVES IN QUICKLY BEHIND THE FRONTAL BOUNDARY...AS WK HIGH PRESSURE PUSHES IN FROM THE SOUTHWEST. WL LEAVE FRIDAY NGT AND SATURDAY DRY FOR NOW. AVIATION /08Z-06Z/... VFR THRU PRD. WNDS BELOW 10 KTS. ONLY A FEW HIGH CLDS XPCTD. MARINE... NO FLAGS THRU MON AS HIGH PRS MOVES OFFSHORE. WNDS AOB 15 KTS. SEAS REMAIN IN THE 3-4 FT RANGE DUE TO RESIDUAL SWELL. DATA SUGGESTS OUR TYPICAL NOCTURNAL SPIKE IN SW WNDS MONDAY NIGHT INTO ERLY TUE...BUT WILL HOLD WNDS TO ARND 15 KT ATTM. BKDR FRNT NOW PROGGED TO ENTER NRN HALF OF MARINE AREA LATE TUE...TURNING WNDS INTO A E-SE DRCTN TUE NITE. FRNT THEN PROGGED TO LIFT BACK N AS A WRM FRNT WED...RESULTING IN SW WNDS ONCE AGAIN. FIRE WEATHER... LOW RH ONCE AGAIN TODAY. UTILIZED RUC/LOCAL WRF MODIFIED SOUNDING AND TRENDED RH/DEWPOINT WELL BELOW GUIDANCE...GIVEN POOR MODEL PERFORMANCE ON TD OF LATE. HOWEVER...EVEN WITH DRYING FUELS...LGT WNDS SHOULD DIMINISH ANY FIRE WEATHER CONCERNS CONSIDERABLY. EVEN STILL.. WL AGAIN MENTION DRY COND IN FWF...BUT WL HOLD OFF ON ANY STATEMENTS ATTM. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SHORT TERM...SMF md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 329 AM EDT SUN APR 22 2007 .SHORT TERM /TODAY THROUGH MONDAY NIGHT/... SHORT TERM CHALLENGES WERE PRIMARILY IN REFINING TEMPERATURES. BROAD AREA OF HIGH PRESSURE CONTINUES TO DOMINATE OVER THE EASTERN CONUS...WITH CLOSEST RADAR ECHOES OF NOTE OVER THE PLAINS STATES. ANOTHER WARM/DRY AFTN...AS HIGH PRESSURE CONTINUES TO SLOWLY DRIFT SE...MOVING OFF CAROLINA COAST THIS AFTN. RAPIDLY RISING HEIGHTS THIS AFTN...AND WARM/DRY RETURN FLOW BY AFTERNOON...SUGGESTS L/M 80S EASILY ATTAINABLE FOR MOST OF CWA...TO AROUND 80 AT IMMEDIATE COAST AND OVER EASTERN SHORE. EXPECTING SEA BREEZE TO AGAIN PLAY A ROLE OVER COASTAL PLAIN THIS AFTN. ONCE AGAIN AGAINST IMMEDIATE COASTLINE WITH VRY LGT SYNOPTIC WNDS THIS AFTN. HV MADE SOME MINOR ADJUSTMENTS OVER THESE LOCATIONS TO REFLECT SLIGHTLY COOLER TEMPS BY MID TO LT AFTERNOON IVOF ORF/CPK/NCZ102. USED MAV/MET BLEND FOR TEMPERATURES THIS AFTN...AND TRENDED TOWARDS COOLER MAV GUIDANCE FOR TONIGHT WITH LTL/ANY DISCERNIBLE CLOUD COVER ALLOWING FOR ANOTHER GOOD RADIATING NGT. ANOTHER WARM/DRY DAY ON TAP FOR MONDAY...WITH M/U 80S LOOKING POSSIBLE FOR PIEDMONT AND CENTRAL VA (L/M 80S AT COAST) WITH ROBUST RETURN FLOW BY MONDAY AFTN. WENT CLOSER TO WARMER MAV GUIDANCE FOR HIGHS ON MONDAY. CLOUDS SLOWLY INCREASE BY MONDAY NGT/ERY TUESDAY AHEAD OF NEXT WEATHER MAKER. && .LONG TERM /TUESDAY THROUGH SATURDAY/... BIGGEST CHALLENGE IN EXTENDED WAS IN TIMING AND DETERMINING PCPN CHANCES FOR MID TO LATE WEEK. STILL GOOD MODEL AGREEMENT THAT FIRST FRONTAL SYSTEM WL REMAIN NORTH OF THE AREA....GENERALLY REMAINING ORIENTED FROM SOUTHERN NEW ENGLAND SOUTH INTO NORTHERN VA AND EXTENDING INTO THE OHIO VLY. 00Z/APR22 GFS DOES BRING BACKDOOR FRONTAL BNDRY A BIT FURTHER SOUTH THAN NAM. HOWEVER DO NOT SEE MUCH IN THE WAY OF FORCING THAT WOULD SUPPORT THIS SOLN ATTM. FOR NOW...WL PUSH FRONT AS FAR SOUTH AS FAR NORTHERN COUNTIES...RESULTING IN MOST OF THE AREA REMAINING DRY...AND REMAINING WITHIN WARM SECTOR. DUE TO THE PROXIMITY OF THE FRONT...WL INCREASE CLD COVER OVER THE NORTH AND KEEP SLIGHT CHANCE POPS FOR RIC-WAL AND NORTH FOR TUES NGT/WED. FUTURE SHIFTS WL BE ABLE TO ADJUST THIS AS NECESSARY. EITHER WAY...IT SHOULD BE NOTED THAT MEAGER AVAILABLE PCPN (PW VALUES REMAIN UNDERWHELMING) AND LACK OF ANY VIABLE CONVERGENCE CONTINUE TO BOLSTER BELIEF THAT ANY PCPN THAT DOES THREATEN THE AREA WL BE LGT AND VERY SMALL IN AREAL COVERAGE. FRONT DRIFTS BACK NORTH WEDNESDAY. AGREE WITH GOING FORECAST THAT A SIZABLE TEMPERATURE GRADIENT COULD EXIST BETWEEN NORTHERN AND SOUTHERN CWA...WITH LINGERING CLOUDINESS AND SCTD SHRAS HOLDING TEMPS BACK A BIT OVER NORTHERN SECTIONS. HOWEVER...KEPT TEMPS A LITTLE WARMER THAN MEX VALUES GIVEN LACK OF MODEL CONTINUITY OF LATE. NEXT...AND MORE LKLY PCPN THREAT COMES WITH A STRONGER FRONTAL PASSAGE THU NGT/FRI. LOW PRESSURE WL DEVELOP OVER THE MO VLY BY THU...TRACKING EASTWARD ALONG THE FRONTAL BOUNDARY. MODEL GUIDANCE CONTINUES TO KEEP BEST SLUG OF MOISTURE NORTH OF THE AREA. NONETHELESS...CONTINUING THE GOING CHC (30) POP FOR SHRAS/TSTMS AS H5 TROF PUSHES THROUGH ERY FRIDAY INTO FRI AFTN LKS GOOD. DRIER WX MOVES IN QUICKLY BEHIND THE FRONTAL BOUNDARY...AS WK HIGH PRESSURE PUSHES IN FROM THE SOUTHWEST. WL LEAVE FRIDAY NGT AND SATURDAY DRY FOR NOW. && .AVIATION /08Z-06Z/... VFR THRU PRD. WNDS BELOW 10 KTS. ONLY A FEW HIGH CLDS XPCTD. && .MARINE... NO FLAGS THRU MON AS HIGH PRS MOVES OFFSHORE. WNDS AOB 15 KTS. SEAS REMAIN IN THE 3-4 FT RANGE DUE TO RESIDUAL SWELL. DATA SUGGESTS OUR TYPICAL NOCTURNAL SPIKE IN SW WNDS MONDAY NIGHT INTO ERLY TUE...BUT WILL HOLD WNDS TO ARND 15 KT ATTM. BKDR FRNT NOW PROGGED TO ENTER NRN HALF OF MARINE AREA LATE TUE...TURNING WNDS INTO A E-SE DRCTN TUE NITE. FRNT THEN PROGGED TO LIFT BACK N AS A WRM FRNT WED...RESULTING IN SW WNDS ONCE AGAIN. && .FIRE WEATHER... LOW RH ONCE AGAIN TODAY. UTILIZED RUC/LOCAL WRF MODIFIED SOUNDING AND TRENDED RH/DEWPOINT WELL BELOW GUIDANCE...GIVEN POOR MODEL PERFORMANCE ON TD OF LATE. HOWEVER...EVEN WITH DRYING FUELS...LGT WNDS SHOULD DIMINISH ANY FIRE WEATHER CONCERNS CONSIDERABLY. EVEN STILL.. WL AGAIN MENTION DRY COND IN FWF...BUT WL HOLD OFF ON ANY STATEMENTS ATTM. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SHORT TERM...MONTEFUSCO LONG TERM...MONTEFUSCO AVIATION...RUSNAK MARINE...RUSNAK FIRE WEATHER...MONTEFUSCO md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 431 PM EDT SUN APR 22 2007 .SHORT TERM (TONIGHT AND MON)... MAIN FCST ISSUES ARE COVERAGE OF SHRA/TSRA TONIGHT AND TIMING THE ENDING OF PCPN MON. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE LIFTING NE THRU THE CNTRL PLAINS...ACCOMPANIED BY SHRA/TSRA. AT THE SFC...LOW PRES WAS LOCATED OVER ERN NEBRASKA WITH A STATIONARY FRONT TRANSITIONING TO COLD FRONT EXTENDING NE TOWARD KDLH AND CYQT. WITH FORCING FROM SHORTWAVE SPREADING NE...SHRA/TSRA ARE DEVELOPING QUICKLY NE ALONG AND JUST BEHIND COLD FRONT. CLOSER TO HOME...AS EXPECTED...CRITICAL FIRE WX CONDITIONS HAVE MATERIALIZED THIS AFTN GENERALLY OVER THE W HALF OF UPPER MI. SFC DWPTS WERE SLOW TO FALL THRU EARLY AFTN...BUT ONCE MIXING BECAME SUFFICIENTLY DEEP TO TAP THE DRY AIR ALOFT INDICATED BY 12Z KGRB SOUNDING AND TAMDAR SOUNDINGS AT KSAW...DWPTS STARTED TO FALL. IN ADDITION...TEMPS HAVE RISEN SLIGHTLY HIGHER THAN ANTICIPATED. THUS...RH HAS DROPPED WELL DOWN INTO THE 20S. GUSTY WINDS ARE INCREASING THE CRITICAL FIRE WX CONDITIONS. APPROACHING SHORTWAVE WILL BEGIN TO SHEAR AND WEAKEN AS IT TRACKS INTO THE GREAT LAKES REGION TONIGHT. AT THE SAME TIME...COLD FRONT WILL BE MOVING ACROSS THE FCST AREA...REACHING THE W DURING THE EVENING AND EXITING THE E AROUND 12Z. ALTHOUGH FORCING WILL BE WEAKENING AND THERE IS ANTECEDENT DRY AIR TO OVERCOME...EXPECT FORCING TO BE SUFFICIENT TO FOCUS DECENT SHRA COVERAGE ALONG/BEHIND SHARP COLD FRONT TONIGHT. CONVERGENCE ALONG BOUNDARY IS QUITE STRONG WHICH INCREASES CONFIDENCE FOR WIDEPSREAD PCPN. AS FOR SVR THREAT... 0-3KM MUCAPE IS A FEW HUNDRED J/KG AT MOST. WHILE DEEP LAYER SHEAR IS SUFFICIENT (30-40KT) FOR ROTATING UPDRAFTS...LACK OF CAPE SUGGEST LITTLE/NO SVR THREAT. ON LAKE SUPERIOR...WILL NEED TO WATCH FOR A BRIEF PERIOD OF HIGH WINDS TO NEAR GALE FORCE AS SHARP WIND SHIFT CROSSES THE LAKE. NAM HAS 950MB WINDS INCREASING TO 40KT OVER THE E HALF OF LAKE SUPERIOR AND RUC13 SHOWS SFC WINDS JUST SHY OF GALES. ALTHOUGH PROFILE DOES NOT BECOME UNSTABLE OVER THE LAKE...LOW-LEVEL CAA IS FAIRLY IMPRESSIVE. HAVE BUMPED WINDS UP TO 30KT FOR NOW. INHERITED FCST LOOKED FINE FOR TIMING ENDING OF SHRA FROM W TO E MON MORNING INTO EARLY AFTN WITH DECREASING CLOUDS FOLLOWING. LOWERED TEMPS A BIT NEAR LAKE SUPERIOR E OF MARQUETTE AS A STIFF N TO NW WIND IS EXPECTED OVER THE E HALF OF THE LAKE. .LONG TERM (MONDAY NIGHT THROUGH SUNDAY)... FOR MONDAY NIGHT THROUGH TUESDAY NIGHT...ZONAL FLOW WILL TAKE OVER ALOFT WITH HIGH PRESSURE SINKING SOUTHEASTWARD FROM NORTHERN SASKATCHEWAN AND MANITOBA...ACROSS THE BORDER AND INTO TRI-STATE REGION. WITH THIS STRONG SURFACE HIGH OVERHEAD IT WILL REMAIN DIFFICULT FOR THE ALREADY WEAKENING SURFACE LOW ACROSS CENTRAL KANSAS BY 00Z WEDNESDAY...TO SURGE NORTHWARD AND INFLUENCE OUR ONGOING DRY WEATHER. UNLIKE OUR BRIEF GLIMPSE OF SUMMER LIKE TEMPERATURES...AFTERNOON HIGH TEMPERATURES WILL REMAIN NEAR CLIMATOLOGICAL NORMAL VALUES...IN THE LOWER 50S NORTH TO MID 50S SOUTH. AT 500MB THE 00Z CANADIAN RUN FOR THIS NEXT LOW TO CROSS THE CENTRAL PLAINS...WEDNESDAY INTO THURSDAY...LOOKS VERY SIMILAR TO THE CURRENT SYSTEM SITTING OVER SOUTHERN NEBRASKA. THIS ALSO IS A STRIKING COMPARISON TO THE 06Z RUN OF THE GFS FROM YESTERDAY. HOWEVER...WITH THE GFS HAVING GONE BACK TO A MORE SOUTHERLY TRACK AND CONSENSUS BACKING THIS UP...WILL DISCARD THE 00Z CANADIAN. THIS WILL CONTINUE TO MEAN A DRY FORECAST FOR THE ENTIRE UPPER PENINSULA. AT THIS TIME...RAIN IS EXPECTED TO STAY 50 OR SO MILES TO THE SOUTH OF MENOMINEE. AS FOR CLOSER TO THE WEEKEND...MODELS ARE HAVING A HARD TIME FIGURING OUT WHERE TO PLACE THE NEXT CUT OFF LOW OVER THE SOUTHWESTERN STATES. IT LOOKS LIKE THE LATEST RUNS HAVE PLACED IT ABOUT 500 MILES FURTHER SOUTHEAST...AND OVER THE BAJA REGION INSTEAD OF NORTHERN NEW MEXICO. THE 06Z GFS SEEMS TO BE THE SLOWEST OF THE MODELS WITH THIS FEATURE...WITH ITS 00Z RUN MORE OF A COMPROMISE BETWEEN THE MORE EASTWARD 00Z CANADIAN AND 00Z ECMWF. GENERALLY FOLLOWED HPC GUIDANCE FOR DAYS 3 THROUGH 7 (THURSDAY THROUGH SUNDAY)...WHICH WAS A COMPROMISE BETWEEN THE 00Z ECMWF AND 00Z GFS ENS MEAN. SOME MINOR CHANGES TO THE HPC GUIDANCE WAS TO LOWER POPS SLIGHTLY FOR THURSDAY NIGHT INTO FRIDAY MORNING...KEEPING OUR DRY FORECAST IN PLACE. AFTER THAT...HAVE PUT IN SLIGHT CHANCE TO LOW CHANCE POPS FOR THE WEAKENING COLD FRONT THAT WILL SLIDE OVER THE CWA FRIDAY NIGHT. HAVE ONLY A SHORT BREAK IN THE PRECIPITATION SATURDAY NIGHT BEFORE THE APPROACH OF THE NEXT FRONTAL SYSTEM...WITH THE SFC LOW CENTERED OVER NORTHERN MANITOBA BY 12Z SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING MIZ004-005-010>012 UNTIL 8 PM EDT TODAY. && $$ ROLFSON (SHORT TERM) KF (LONG TERM) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1230 PM EDT SUN APR 22 2007 .UPDATE... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE LIFTING NE INTO THE CNTRL PLAINS...ACCOMPANIED BY SHRA/TSRA. CLOSER TO HOME...DRY AIRMASS COVERS MUCH OF WI/UPPER MI PER EARLY MORNING TAMDAR SOUNDING FROM KSAW AND 12Z KGRB SOUNDING. AMOUNT OF DRY AIR AVAILABLE TO MIX DOWN RAISES FIRE WX CONCERNS AS MIXING TO 800MB ON KGRB SOUNDING WOULD BRING SFC DWPTS DOWN TO THE MID 30S. WITH HIGHS NEARING 80F...RH WOULD FALL TO NEAR 20PCT. HOWEVER...ITS TOUGH TO DETERMINE IF DWPTS WILL FALL THAT FAR AS THERE IS A FAIRLY TIGHT MOISTURE GRADIENT OVER THE UPPER MIDWEST (NOTE THE MOIST PROFILE ON 12Z KMPX SOUNDING). APPROACHING SHORTWAVE SHOULD PLAY A ROLE AS SLIGHT BACKING OF LOW/MIDLEVEL WINDS AHEAD OF IT SHOULD HELP MAINTAIN THE DRY AIR OVER ERN WI INTO MUCH OF UPPER MI THIS AFTN. WITH SUSTAINED WINDS OF 15-20MPH...TEMPS RISING TO 75-80F OVER MUCH OF THE W HALF OF UPPER AND RH DROPPING TOWARD 25PCT...IT WILL BE A CRITICAL FIRE WX DAY...ESPECIALLY BTWN L`ANSE/MARQUETTE AND IRON RIVER/MENOMINEE. ELSEWHERE...TEMPS ALONG THE LAKESHORE E OF ESCANABA MAY NOT RISE ABOVE THE LWR 50S WITH A STIFF WIND OFF LAKE MICHIGAN. OVER THE FAR W...SLACKENING PRES GRADIENT NEAR APPROACHING COLD FRONT MAY ALLOW LAKE BREEZE TO DEVELOP LATE...RESULTING IN A SHARP TEMP DROP NEAR THE LAKE LATE IN THE AFTN. AS FOR PCPN...TRIMMED BACK EWD PROGRESS OF SHRA/TSRA INTO WRN UPPER MI LATE THIS AFTN BASED ON THE DRY AIR OVER THE AREA. AS COLD FRONT OVER NE MN MOVES INTO UPPER MI TONIGHT...BOUNDARY SHOULD PROVIDE A NICE FOCUSING MECHANISM FOR FORCING FROM SHORTWAVE TO ACT UPON... RESULTING IN DECENT PCPN COVERAGE. && .PREV DISCUSSION (ISSUED AT 355 AM EDT)... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE GRT LKS BTWN LARGER SCALE TROFS OVER THE W AND IN THE WRN ATLANTIC. CWA DOMINATED BY SW FLOW BTWN HI PRES IN THE MID ATLANTIC STATES AND LO PRES TROF STRETCHING FM THE CNTRL PLAINS INTO MN ON THE ERN FLANK OF WRN TROF. ALTHOUGH 00Z GRB/MPX/APX SDNGS ARE QUITE DRY AND CAPPED...A FEW SHRA/TSRA NOTED OVER OVER THE MN ARROWHEAD AND INTO ERN LK SUP WHERE SHRTWV RUC SHOWS MOVING THRU NRN MN/ADJOINING ONTARIO IS INTERACTING WITH H85 WARM FNT ON THE NRN EDGE OF MID LVL CAPPING MARKED BY H7 TEMP ARND 2C. SKIES MOCLR TO THE S OF WARM FNT DESPITE STEEP H7-5 LAPSE RATES SHOWN ON THE 00Z MPX SDNG ABV H7 WARM NOSE/CAP. MORE WDSPRD CNVCTN HAS BROKEN OUT AS FAR E AS WRN MN ALG WARM FNT IN ADVANCE OF POTENT SHRTWV LIFTING OUT OF THE SRN ROCKIES. OTHER SHRTWVS ROTATING WITHIN WRN TROF ARE LOCATED OVER SRN SASKATCHEWAN AND JUST OFF THE CA COAST. MAIN FCST CONCERNS TDAY REVOLVE ARND DISPOSITION OF ONGOING CNVCTN FM THE MN ARROWHEAD INTO ERN LK SUP AND FIRE WX ISSUES. FOCUS FOR TNGT/MON SHIFTS TO SHRA/TSRA CHCS ASSOCIATED WITH SHRTWV NOW LIFTING OUT OF THE SRN ROCKIES. FOR EARLY THIS MRNG...RUC SHOWS SHRTWV HELPING TO INITIATE CNVCTN ALG H85 WARM FNT MOVING ENE THRU ONTARIO N OF LK SUP. MODEL SHOWS H85-5 QVECTOR CNVGC ASSOCIATED WITH DPVA AND WAD LINGERING OVER ERN LK SUP UNTIL ABOUT 09Z WHEN THE SYS IS PROGGED TO MOVE CLOSER TO JAMES BAY. ANOTHER ROUND OF DEEP LYR H85-3 QVECTOR CNVGC ASSOCIATED WITH ANOTHER SHRTWV PROGGED TO LIFT TOWARD WRN LK SUP BY 12Z. SO EXPECT CNVCTN OVER NE LK SUP TO DIMINISH BY FCST ISSUANCE...BUT WL MAINTAIN MENTION OF SCT TSRA OVER WRN LK SUP THIS MRNG. THIS NEXT SHRTWV FCST TO SLIDE NE INTO ONTARIO AS WELL BEFORE NEXT ROUND OF DEEP LYR H85-3 QVECTOR CNVGC AHEAD OF STRONGER SHRTWV FCST TO REACH IA BY 00Z MON ARRIVES LATER IN THE DAY. NAM/GFS FCST SDNGS INDICATE MID LVLS WL REMAIN SUFFICIENTLY CAPPED THRU MOST OF THE DAY TO KEEP LAND FA DRY EVEN THOUGH SCT SHRA/TSRA WL PERSIST OVER WRN LK SUP ON EDGE OF CAP AND CLOSER TO APRCHG COOL FNT ASSOCIATED WITH SHRTWV NOW IN SASKATCHEWAN. BULK OF MODELS GENERATE SOME LGT QPF OVER THE FAR WRN ZNS BY 00Z MON JUST IN ADVANCE OF THIS COLD FNT. CONSIDERING DRY NATURE OF LLVLS TO THE SW (MIXING TO H8 ON 00Z MPX SDNG WOULD YIELD SFC DWPT ARND 40...DVN SDNG IS EVEN DRIER) AS WELL AS ACYC H85 FLOW IN ADVANCE OF FNT...THINK GUIDANCE MAY BE A BIT TOO AGGRESSIVE AT SPITTING OUT PCPN EVEN OVER THE FAR W BEFORE 00Z AND COLD FROPA... ESPECIALLY SINCE BOTH MODELS PUSH SFC DWPTS INTO THE LOW 50S AT IWD BY 00Z. BUT SINCE GOING FCST HAS CHC POPS OVER THE FAR W AFT 21Z AND MODELS GENERATE SOME QPF...WL MAINTAIN LO CHC POPS FM CMX-IWD. AS FOR FIRE WX CONCERNS...MIXING TO H8-825 ON GFS/NAM FCST SDNGS WOULD SUPPORT HI TEMPS IN THE 75 TO 80 RANGE AWAY FM THE MODERATING INFLUENCE OF LK MI. LOOKING AT THE UPSTREAM MPX/DVN SDNGS...MODELS LOOK TOO AGGRESSIVE AT RETURNING LLVL MSTR AND PUSHING DWPTS AOA 50. IF DWPTS ARE 40 E TO 48 W...EXPECT RH TO DROP AS LO AS 25 TO 30 PCT AGAIN. WITH GUSTY WINDS LIKELY (NAM AND ESPECIALLY THE GFS SHOW MIXED LYR WINDS INCRSG TO 25 TO 35 KT)... FIRE WX PARAMETERS WL APRCH CRITICAL LVLS AGAIN TDAY. FOR TNGT...NAM/GFS DIVERGE ON FCST OF HANDLING OF SHRTWV IN IA AT 00Z MON...WITH GFS SHOWING SHRTWV MOVING TO JUST S OF GRB AT 12 MON WHILE NAM HOLDS SHRTWV BACK OVER NW IL. WITH SUPPORT FM THE MOST CONSISTENT 00Z UKMET (WHICH IS NCEP FVRD MODEL)...WL FOLLOW THE MORE SIMILAR GFS SCENARIO. MEANWHILE... GFS/UKMET FCST SHRTWV IN SASKATCHEWAN THIS PAST EVNG TO MOVE ACRS ONTARIO...WITH ACCOMPANYING SFC COLD FNT MOVING TO ABOUT P53-MNM BY 12Z MON. SINCE THESE SHRTWVS ARE FCST TO REMAIN OUT OF PHASE THRU THE NGT...GFS SHOWS TWO STRIPES OF HEAVIER PCPN. THE FIRST OF THESE IS OVER THE WRN ZNS DURING THE NGT DUE TO MORE SGNFT UPR DVGC IN RRQ OF UPR JET SUPPORTING ONTARIO SHRTWV AS WELL AS SHARP H85-7 FGEN BEHIND THE ASSOCIATED SFC FNT. GFS SHOWS THESE DYNAMICS TENDING TO SHIFT MORE NE DURING THE NGT...SO ITS HEAVIER QPF DOES NOT SPREAD E. THE UKMET ON THE OTHER HAND INDICATES THE SHARPER UPR DVGC/FGEN WL SPREAD FARTHER E...SO IT DRAGS HEAVIER PCPN INTO THE CNTRL ZNS BY 12Z. THE GFS ALSO FCSTS AN AXIS OF HEAVIER QPF ACRS THE SCNTRL ON THE CYC SIDE OF SHRTWV PASSAGE THRU WI AND WHERE INSTABILITY IS A BIT MORE IMPRESSIVE. CONCERNING SVR THREAT...OLD DAY 2 CONVECTIVE OUTLOOK HAD MUCH OF THE W HALF OF THE FA IN SLGT RISK. THINK BEST CHC OF SVR TSRA WOULD BE IN THE 00Z-06Z TIME FRAME ALONG AND JUST BEHIND COLD FROPA OVER THE W WHEN FCST 0-6KM BULK SHEAR NEAR 50KT WOULD BE BETTER PHASED WITH LOWER SSI FCST IN THE -2C TO -3C RANGE/STEEPER SFC-H8 LAPSE RATES THAT WOULD ALLOW MORE EFFICIENT TRANSFER OF GUSTY WINDS TO THE SFC. HOWEVER... MODIFIED GFS FCS SDNG FOR IWD AT 00Z FOR SFC T/TD 73/50 AND SOMEWHAT COOLER MID LVL TEMPS THAN EXPLICITLY FCST BY GFS YIELDS MO MORE THAN A FEW HUNDRED J/KG OF SFC BASED CAPE. ALTHOUGH WBZ FCST AT A FVRBL 9.5K FT...FCST MARGINAL LAPSE RATES WOULD HAVE A DIFFICULT TIME SUPPORTING LARGE HAIL. FCST LAPSE RATES/SHEAR PROGGED TO DIMINISH SGNFTLY AFT 06Z...SO ANY SVR THREAT SHOULD DIMINISH OVERNGT AS THE FNT PUSHES E. NOT SURPRISINGLY...THE NEW DAY1 CONVECTIVE OUTLOOK NO LONGER SHOWS THE FA IN THE SLGT RISK. SINCE NCEP INDICATES THE GFS BECOMES TOO FAST ON MON...TENDED TO FOLLOW THE UKMET FCST FOR FCST PREPARATION. AS PAIR OF SHRTWVS MOVE TO THE E...MODEL FCSTS COLD FROPA AT ERY BY 15Z...WITH LINGERING DEEP MSTR/SHARP H85-7 FGEN CLEARING THAT POINT BY 18Z. WL KEEP LINGERING HIER POPS OVER THE E HALF IN THE MRNG WITH POPS TO THE W DIMINISHING W-E AS COOLER AND DRIER AIR OVERSPREADS THE FA. SINCE UKMET IS SLOW TO LOWER H85 DWPT (SIMILAR TO OTHER MODELS)...SUSPECT THERE WL BE A GOOD AMT OF SC IN THE AFTN OVER AREAS INLAND FM THE STABILIZING INFLUENCE OF LK SUP. MUCH DRIER AIR LOOKS TO ARRIVE LATER IN THE DAY...SO EXPECT CLRG OF THE SC LATER WITH LOWERING SUN ANGLE. MON WL TURN OUT MUCH COOLER WITH UKMET SHOWING H85 TEMP LOWERING TO 2 TO 4C BY 00Z TUE. QUIET AND COOLER WX LOOKS ON TAP MON NGT THRU MOST OF THE REST OF THE WEEK AS CNDN HI PRES BLDS FM THE NW TERRITORIES INTO ONTARIO. NEXT SHRTWV NOW MOVING TOWARD CA LOOKS LIKE IT WL REMAIN WELL TO THE S AS IT MOVES E. JUST MINOR CHGS TO MESH BETTER WITH SURROUNDING OFFICES MADE TO GOING FCST. COORDINATED WITH GRB. && .MQT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING MIZ004-005-010>012 UNTIL 8 PM EDT TODAY. && $$ ROLFSON (UPDATE) KC (PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 355 AM EDT SUN APR 22 2007 .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE GRT LKS BTWN LARGER SCALE TROFS OVER THE W AND IN THE WRN ATLANTIC. CWA DOMINATED BY SW FLOW BTWN HI PRES IN THE MID ATLANTIC STATES AND LO PRES TROF STRETCHING FM THE CNTRL PLAINS INTO MN ON THE ERN FLANK OF WRN TROF. ALTHOUGH 00Z GRB/MPX/APX SDNGS ARE QUITE DRY AND CAPPED...A FEW SHRA/TSRA NOTED OVER OVER THE MN ARROWHEAD AND INTO ERN LK SUP WHERE SHRTWV RUC SHOWS MOVING THRU NRN MN/ADJOINING ONTARIO IS INTERACTING WITH H85 WARM FNT ON THE NRN EDGE OF MID LVL CAPPING MARKED BY H7 TEMP ARND 2C. SKIES MOCLR TO THE S OF WARM FNT DESPITE STEEP H7-5 LAPSE RATES SHOWN ON THE 00Z MPX SDNG ABV H7 WARM NOSE/CAP. MORE WDSPRD CNVCTN HAS BROKEN OUT AS FAR E AS WRN MN ALG WARM FNT IN ADVANCE OF POTENT SHRTWV LIFTING OUT OF THE SRN ROCKIES. OTHER SHRTWVS ROTATING WITHIN WRN TROF ARE LOCATED OVER SRN SASKATCHEWAN AND JUST OFF THE CA COAST. MAIN FCST CONCERNS TDAY REVOLVE ARND DISPOSITION OF ONGOING CNVCTN FM THE MN ARROWHEAD INTO ERN LK SUP AND FIRE WX ISSUES. FOCUS FOR TNGT/MON SHIFTS TO SHRA/TSRA CHCS ASSOCIATED WITH SHRTWV NOW LIFTING OUT OF THE SRN ROCKIES. FOR EARLY THIS MRNG...RUC SHOWS SHRTWV HELPING TO INITIATE CNVCTN ALG H85 WARM FNT MOVING ENE THRU ONTARIO N OF LK SUP. MODEL SHOWS H85-5 QVECTOR CNVGC ASSOCIATED WITH DPVA AND WAD LINGERING OVER ERN LK SUP UNTIL ABOUT 09Z WHEN THE SYS IS PROGGED TO MOVE CLOSER TO JAMES BAY. ANOTHER ROUND OF DEEP LYR H85-3 QVECTOR CNVGC ASSOCIATED WITH ANOTHER SHRTWV PROGGED TO LIFT TOWARD WRN LK SUP BY 12Z. SO EXPECT CNVCTN OVER NE LK SUP TO DIMINISH BY FCST ISSUANCE...BUT WL MAINTAIN MENTION OF SCT TSRA OVER WRN LK SUP THIS MRNG. THIS NEXT SHRTWV FCST TO SLIDE NE INTO ONTARIO AS WELL BEFORE NEXT ROUND OF DEEP LYR H85-3 QVECTOR CNVGC AHEAD OF STRONGER SHRTWV FCST TO REACH IA BY 00Z MON ARRIVES LATER IN THE DAY. NAM/GFS FCST SDNGS INDICATE MID LVLS WL REMAIN SUFFICIENTLY CAPPED THRU MOST OF THE DAY TO KEEP LAND FA DRY EVEN THOUGH SCT SHRA/TSRA WL PERSIST OVER WRN LK SUP ON EDGE OF CAP AND CLOSER TO APRCHG COOL FNT ASSOCIATED WITH SHRTWV NOW IN SASKATCHEWAN. BULK OF MODELS GENERATE SOME LGT QPF OVER THE FAR WRN ZNS BY 00Z MON JUST IN ADVANCE OF THIS COLD FNT. CONSIDERING DRY NATURE OF LLVLS TO THE SW (MIXING TO H8 ON 00Z MPX SDNG WOULD YIELD SFC DWPT ARND 40...DVN SDNG IS EVEN DRIER) AS WELL AS ACYC H85 FLOW IN ADVANCE OF FNT...THINK GUIDANCE MAY BE A BIT TOO AGGRESSIVE AT SPITTING OUT PCPN EVEN OVER THE FAR W BEFORE 00Z AND COLD FROPA... ESPECIALLY SINCE BOTH MODELS PUSH SFC DWPTS INTO THE LOW 50S AT IWD BY 00Z. BUT SINCE GOING FCST HAS CHC POPS OVER THE FAR W AFT 21Z AND MODELS GENERATE SOME QPF...WL MAINTAIN LO CHC POPS FM CMX-IWD. AS FOR FIRE WX CONCERNS...MIXING TO H8-825 ON GFS/NAM FCST SDNGS WOULD SUPPORT HI TEMPS IN THE 75 TO 80 RANGE AWAY FM THE MODERATING INFLUENCE OF LK MI. LOOKING AT THE UPSTREAM MPX/DVN SDNGS...MODELS LOOK TOO AGGRESSIVE AT RETURNING LLVL MSTR AND PUSHING DWPTS AOA 50. IF DWPTS ARE 40 E TO 48 W...EXPECT RH TO DROP AS LO AS 25 TO 30 PCT AGAIN. WITH GUSTY WINDS LIKELY (NAM AND ESPECIALLY THE GFS SHOW MIXED LYR WINDS INCRSG TO 25 TO 35 KT)... FIRE WX PARAMETERS WL APRCH CRITICAL LVLS AGAIN TDAY. FOR TNGT...NAM/GFS DIVERGE ON FCST OF HANDLING OF SHRTWV IN IA AT 00Z MON...WITH GFS SHOWING SHRTWV MOVING TO JUST S OF GRB AT 12 MON WHILE NAM HOLDS SHRTWV BACK OVER NW IL. WITH SUPPORT FM THE MOST CONSISTENT 00Z UKMET (WHICH IS NCEP FVRD MODEL)...WL FOLLOW THE MORE SIMILAR GFS SCENARIO. MEANWHILE... GFS/UKMET FCST SHRTWV IN SASKATCHEWAN THIS PAST EVNG TO MOVE ACRS ONTARIO...WITH ACCOMPANYING SFC COLD FNT MOVING TO ABOUT P53-MNM BY 12Z MON. SINCE THESE SHRTWVS ARE FCST TO REMAIN OUT OF PHASE THRU THE NGT...GFS SHOWS TWO STRIPES OF HEAVIER PCPN. THE FIRST OF THESE IS OVER THE WRN ZNS DURING THE NGT DUE TO MORE SGNFT UPR DVGC IN RRQ OF UPR JET SUPPORTING ONTARIO SHRTWV AS WELL AS SHARP H85-7 FGEN BEHIND THE ASSOCIATED SFC FNT. GFS SHOWS THESE DYNAMICS TENDING TO SHIFT MORE NE DURING THE NGT...SO ITS HEAVIER QPF DOES NOT SPREAD E. THE UKMET ON THE OTHER HAND INDICATES THE SHARPER UPR DVGC/FGEN WL SPREAD FARTHER E...SO IT DRAGS HEAVIER PCPN INTO THE CNTRL ZNS BY 12Z. THE GFS ALSO FCSTS AN AXIS OF HEAVIER QPF ACRS THE SCNTRL ON THE CYC SIDE OF SHRTWV PASSAGE THRU WI AND WHERE INSTABILITY IS A BIT MORE IMPRESSIVE. CONCERNING SVR THREAT...OLD DAY 2 CONVECTIVE OUTLOOK HAD MUCH OF THE W HALF OF THE FA IN SLGT RISK. THINK BEST CHC OF SVR TSRA WOULD BE IN THE 00Z-06Z TIME FRAME ALONG AND JUST BEHIND COLD FROPA OVER THE W WHEN FCST 0-6KM BULK SHEAR NEAR 50KT WOULD BE BETTER PHASED WITH LOWER SSI FCST IN THE -2C TO -3C RANGE/STEEPER SFC-H8 LAPSE RATES THAT WOULD ALLOW MORE EFFICIENT TRANSFER OF GUSTY WINDS TO THE SFC. HOWEVER... MODIFIED GFS FCS SDNG FOR IWD AT 00Z FOR SFC T/TD 73/50 AND SOMEWHAT COOLER MID LVL TEMPS THAN EXPLICITLY FCST BY GFS YIELDS MO MORE THAN A FEW HUNDRED J/KG OF SFC BASED CAPE. ALTHOUGH WBZ FCST AT A FVRBL 9.5K FT...FCST MARGINAL LAPSE RATES WOULD HAVE A DIFFICULT TIME SUPPORTING LARGE HAIL. FCST LAPSE RATES/SHEAR PROGGED TO DIMINISH SGNFTLY AFT 06Z...SO ANY SVR THREAT SHOULD DIMINISH OVERNGT AS THE FNT PUSHES E. NOT SURPRISINGLY...THE NEW DAY1 CONVECTIVE OUTLOOK NO LONGER SHOWS THE FA IN THE SLGT RISK. SINCE NCEP INDICATES THE GFS BECOMES TOO FAST ON MON...TENDED TO FOLLOW THE UKMET FCST FOR FCST PREPARATION. AS PAIR OF SHRTWVS MOVE TO THE E...MODEL FCSTS COLD FROPA AT ERY BY 15Z...WITH LINGERING DEEP MSTR/SHARP H85-7 FGEN CLEARING THAT POINT BY 18Z. WL KEEP LINGERING HIER POPS OVER THE E HALF IN THE MRNG WITH POPS TO THE W DIMINISHING W-E AS COOLER AND DRIER AIR OVERSPREADS THE FA. SINCE UKMET IS SLOW TO LOWER H85 DWPT (SIMILAR TO OTHER MODELS)...SUSPECT THERE WL BE A GOOD AMT OF SC IN THE AFTN OVER AREAS INLAND FM THE STABILIZING INFLUENCE OF LK SUP. MUCH DRIER AIR LOOKS TO ARRIVE LATER IN THE DAY...SO EXPECT CLRG OF THE SC LATER WITH LOWERING SUN ANGLE. MON WL TURN OUT MUCH COOLER WITH UKMET SHOWING H85 TEMP LOWERING TO 2 TO 4C BY 00Z TUE. QUIET AND COOLER WX LOOKS ON TAP MON NGT THRU MOST OF THE REST OF THE WEEK AS CNDN HI PRES BLDS FM THE NW TERRITORIES INTO ONTARIO. NEXT SHRTWV NOW MOVING TOWARD CA LOOKS LIKE IT WL REMAIN WELL TO THE S AS IT MOVES E. JUST MINOR CHGS TO MESH BETTER WITH SURROUNDING OFFICES MADE TO GOING FCST. COORDINATED WITH GRB. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 134 AM EDT SUN APR 22 2007 .AVIATION...STRONG...DRY HIGH PRESSURE TO OUR SE WILL MAINTAIN VFR CONDITIONS THRU THE NEXT 24 HOURS. THIN HIGH CIRRUS (DEBRIS FROM SHOWERS/TSTORMS OVER UPPER MICHIGAN AND NORTHERN WISCONSIN) WILL PASS ACROSS THE AREA EARLY THIS MORNING. WILL MAINTAIN THE LOW LEVEL WIND SHEAR AT ALL TAF SITES DUE TO INCREASING WIND SPEEDS JUST ABOVE THE SURFACE TONIGHT AS HIGH PRESSURE MOVES FURTHER EAST...AWAY FROM THE REGION. HOWEVER...STABLE AIR AT THE SURFACE WILL KEEP THESE WINDS FROM REACHING GROUND LEVEL UNTIL A FEW HOURS AFTER SUNRISE TODAY. A STORM SYSTEM OVER THE SW UNITED STATES CURRENTLY WILL TRACK TOWARD THE GREAT LAKES TOMORROW NIGHT. MOISTURE WILL INCREASE AHEAD OF THE SYSTEM...BUT VFR CONDITIONS ARE EXPECTED TO HOLD THROUGH THE TAF PERIOD WITH PRECIP ARRIVING AFTER 06Z TOMORROW. MPC && .UPDATE...ISSUED AT 1008 PM EDT SAT APR 21 LATEST RUC AND SURFACE ANALYSIS AND IR/WV/RADAR IMAGERY SHOW SURFACE HIGH PRESSURE MIGRATING EAST OVER THE SOUTHEASTERN GREAT LAKES WHILE THE 500MB RIDGE AXIS IS DIRECTLY OVERHEAD. TO THE WEST...A BROAD SURFACE LOW PRESSURE LIES OVER THE CENTRAL PLAINS WITH A WARM FRONT OVER CENTRAL ONTARIO EXTENDING FROM THE PARENT LOW NORTH OF LAKE WINNIPEG. DEBRIS CLOUDS FROM CONVECTION EARLIER ON TODAY ACROSS MINNESOTA AND NORTHERN WISCONSIN HAVE STARTED PUSHING INTO THE AREA WITH THE MQT RADAR JUST SHOWING A FEW SPOTTY RETURNS OVER CENTRAL LAKE SUPERIOR (EVEN A LIGHTNING STRIKE) AND ALONG THE SOUTH SHORE OF LAKE SUPERIOR RIGHT ALONG OF THE LEADING EDGE OF THE DEEPER MOISTURE AXIS. MAIN FORECAST CONCERNS FOR THE REST OF THE EVENING REVOLVE AROUND THESE SPOTTY SHOWERS...THEN LOW TEMPERATURES AND CLOUD COVER. A FEW CHANGES HAVE BEEN MADE TO THE ONGOING FORECAST. HAVE INCREASED CLOUD COVER ACROSS THE NORTHERN CWA TO ACCOUNT FOR THE CONVECTIVE DEBRIS PASSING OVERHEAD. HAVE ALSO ADDED A CHANCE OF A SPRINKLE ACROSS WHITEFISH BAY AND THE SOO DUE TO THESE SPOTTY SHOWERS...JUST FOR THE EVENING HOURS. ONE SHOWER TO THE EAST OF MQT LOOKS TO HAVE SOME BEEFIER RETURNS AT 3.5KFT THAT HAS POTENTIAL TO REACH THE GROUND DESPITE THE DRY AIR PRESENT (RUC ANALYZED 900-700MB RH 25-30 PCT). PRESSURE GRADIENT BEGINS TO TIGHTEN LATE OVERNIGHT AS THE SURFACE HIGH CONTINUES ITS SE SLIDE. SOUTHERLY RETURN FLOW ON THE WEST SIDE OF THIS HIGH WILL THEN KICK IN AND KEEP OUR TEMPERATURES FROM FALLING AS MUCH AS THE PREVIOUS NIGHTS LOWS. STILL BELIEVE THAT TEMPERATURES WITHIN THE COLD SPOTS AND AREAS ACROSS NE LOWER (WHERE THE PRESSURE GRADIENT TIGHTENS LAST) WILL DROP INTO THE LOWER 40S BUT FOR THE REMAINING AREAS...LOWS WILL FALL INTO THE MIDDLE TO UPPER 40S. ZONES OUT SHORTLY. MPC && .DISCUSSION...ISSUED AT 335 PM EDT SAT APR 21 A HUDSON BAY HIGH IS BEGINNING TO MOVE TO THE EAST SO THAT THE RETURN FLOW IS SLOWLY STARTING. THE OMEGA BLOCK AT 500 MB IS BREAKING DOWN SO THAT THE RIDGE AXIS IS OVER THE WESTERN GREAT LAKES. TO THE WEST OF THAT, THE NEXT SYSTEM WHICH IS EXPECTED TO BREAK DOWN THE RIDGE AND BRING A COLD FRONT THROUGH THE FORECAST AREA ON SUNDAY NIGHT. SO THE MAIN CONCERN IN THE SHORT TERM WILL BE TEMPERATURES AND HUMIDITY AND WIND FOR SUNDAY. TONIGHT...THE GRADIENT BEGINS TO PICK UP, BUT WITH THE SFC INVERSION THAT IS EXPECTED TO SET UP THIS EVENING, THE WINDS WILL REMAIN BELOW 10 MPH. WITH THE STRONG INVERSION AND LOWER SFC WINDS, THE HUMIDITY RECOVERY IS EXPECTED TO BE POOR WITH THE DEWPOINTS EXPECTED TO REMAIN IN THE LOWER TO MID 30S OVERNIGHT. THERE WILL ONLY BE A FEW HIGH CLOUDS SO THE RADIATIONAL COOLING WILL COOL THINGS A BIT, BUT IT WILL REMAIN WARMER THAN LAST NIGHT AS THE SOUTH WIND STAYS UP ALL NIGHT. SUNDAY...AS THE SUN PEEKS OVER THE HORIZON, THE TEMPERATURES WILL BEGIN TO ZOOM INTO THE MID TO UPPER 70S WITH SEVERAL LOWER 80S THROWN IN. THE MET AND MAV NUMBERS RANGE FROM THE UPPER 70S IN PLN AND GLR TO THE LOWER 80S IN GOV, WITH UPPER 70S NEAR THE LAKE SHORES. 950 MB WINDS ON BOTH MODELS ARE RUNNING 25 TO 30 KNOTS THROUGH THE AFTERNOON AND THE SFC WINDS ARE EXPECTED TO BE SUSTAINED AROUND 15 KNOTS AT THE AVIATION SITES. FACTORING IN THE 20FT WIND LEVEL AND THE 10 MIN AVG OF THE RAWS SITES WOULD EXPECT THAT EVEN IF 15 MPH ISN`T SUSTAINED, THERE WILL BE FREQUENT GUSTS TO 20 MPH. THIS IS DUE TO THE FACT THAT WE`RE NOT GOING TO JUST MIX THROUGH 950 OR 850 MB, BUT PROBABLY THROUGH 750 MB LIKE YESTERDAY. THIS WILL HELP KEEP THE SFC RH DOWN AS THE 850 MB RH IS EXPECT TO BE <10% ON THE NAM AND <25% ON THE GFS. WITH THE SW FLOW THE 850 MB TEMPERATURES ARE EXPECTED TO BE AROUND +14C WHICH WHEN MIXED OUT WOULD BRING IN TEMPERATURES AROUND THE LOWER TO MID 80S. SO, HOWEVER YOU CUT IT, IT LOOKS LIKE WE WILL MEET RED FLAG CRITERIA FOR THE AFTERNOON. LUTZ && SUNDAY NIGHT...SFC HIGH PRES PATTERN BEGINS TO BREAK DOWN OVER THE GREAT LAKES IN THE EVENING...AS A STORM SYSTEM OVER THE ROOKIES MOVES INTO THE CENTRAL PLAINS. EXTENDED MODELS BRING THE SYS INTO THE WRN LAKES BTW 06Z AND 12Z MONDAY. AT UPPER LVLS...THE UPPER RIDGING PATTERN ALSO BEGINS TO BREAK DOWN ACRS THE GREAT LAKES REGION...AS AN UPPER LOW ROTATES OUT OF THE CENTRAL PLAINS AND TOWARD THE UPPER LAKES. THE UPPER TROF IS FORECAST TO MOVE INTO THE WRN LAKES AROUND 12Z MONDAY. 850/500 MB RH INCREASES TO 80 PCT OVR THE LAKES BY 12Z MONDAY IN ADVANCE OF THE SFC AND UPPER LVL FEATURES. THEREFORE WILL KEEP THE MENTION OF SHOWERS IN THE FORECAST OVERNIGHT SUNDAY...WITH THE BEST CHANCES BEING OVER WRN LWR AND EAST UPPER WHERE MSTR INCREASES FIRST. WILL KEEP OVERNIGHT LOWS GENERALLY IN THE 50S...DUE TO INCREASING CLOUDS AND MODERATE SOUTHWEST FLOW. MONDAY...SURFACE FRONT MOVES OVER THE LAKES DURING THE DAY...EXITING INTO LAKE HURON AROUND 00Z TUESDAY. UPPER TROUGH QUICKLY MOVES OVER THE STATE IN THE AFTERNOON...WITH NEARLY ZONAL FLOW DEVELOPING LATE AFTN. 850/500 MB RH QUICKLY BEGINS TO DRY OUT OVER THE WRN LAKES AFT 18Z MONDAY...DROPPING FROM AROUND 80 PCT IN THE MORNING TO ARND 40 PCT BY 21Z. WILL MENTION LIKELY POPS ACRS THE FCST AREA THRU THE MORNING. IN THE AFTN...WILL DROP POPS TO CHC OVER THE WRN CWA WHILE MAINTAINING LIKELY POPS OVER THE ERN CWA INTO THE EVENING. WILL MENTION DRY CONDS MONDAY NIGHT ACRS THE ENTIRE FCST AREA...AS SFC HIGH PRESSURE BUILDS BACK ACRS THE REGION AND UPPER ZONAL FLOW PERSISTS. 850/500 MB RH SHOWING DRYING TO AROUND 30 PCT MONDAY NIGHT INTO TUESDAY. WILL MENTION AFTN HIGHS IN THE 55 TO 60 DEGREE RANGE WITH CLOUDS AND RAIN. OVERNIGHT LOWS...WITH CLEARING SKIES AND CALMING WINDS...SHOULD DROP BACK INTO THE LOWER AND MID 30S. TUESDAY...HIGH PRESSURE AND 500MB ZONAL FLOW WILL REMAIN OVER THE REGION THROUGH THE DAY. COLDER 850MB AIR WILL FILTER BACK OVER THE STATE DURING THE DAY...AS 850 MB TEMPS DROP FROM ARND 10C MONDAY TO AROUND +1C TUESDAY AFTN. WILL MENTION AFTN HIGHS IN THE 50S ACRS THE FCST AREA. OVERALL WILL MENTION DRY CONDS DUE TO SFC RIDGING AND 850/500 RH AROUND 40 PCT. HOWEVER EXPECT AFTN CU DEVELOPMENT DUE TO 850 AND 500 MB COLD POOLS ALOFT AFFECTING THE UPPER LAKES. SUBSIDENCE CONDS PERSIST TUESDAY NIGHT...THEREFORE WILL MENTION DRY CONDS INTO WEDNESDAY. WEDNESDAY THROUGH SATURDAY...SFC RIDGING AND NEARLY ZONAL FLOW ALOFT WILL REMAIN OVER THE UPPER LAKES AND UPPER MIDWEST WEDNESDAY INTO THURSDAY. WILL MENTION DRY CONDS AGAIN WEDNESDAY AND EARLY THURSDAY. WILL KEEP HIGHS IN THE 50S WEDNESDAY AS SFC AND UPPER LEVEL FEATURES WILL BE SIMILAR TO THOSE ON TUESDAY. THURSDAY THROUGH SATURDAY... MODEL BEGIN TO DIFFER WITH RESPECT TO SURFACE AND UPPER LEVEL FEATURES AFFECTING THE REGION. A STORM SYSTEM WILL BE DEVELOPING OVER THE SRN ROOKIES WED...AND WILL BEGIN PUSHING NORTH EARLY THURSDAY MOVING TOWARD IND/ILL BY 12Z THURSDAY...BEFORE MOVING OVER THE OHIO VALLEY BY THURSDAY EVENING. HOWEVER MODELS DO HANDLE THE EASTWARD MOVEMENT OF THIS SYSTEM DIFFERENTLY THURSDAY AFTERNOON INTO FRIDAY...WITH THE ECMWF PUSHES THE SFC FEATURE FASTER TOWARD THE EAST COAST. AT UPPER LVLS...MODELS ARE DISORGANIZED WITH THE 500 MB TROUGH/RIDGE PATTERN MOVING OVER THE UPPER MIDWEST THURSDAY...MOVING INTO THE ERN LAKES FRIDAY MORNING. OVERALL SEEMS LIKE A PRETTY STRONG UPPER RIDGE IS BEING BROKEN DOWN TO FAST THURSDAY...WHILE MODELS KEEP THE SFC LOW TO THE SOUTH OF THE STATE. OVERALL THOUGHT IS FORECAST WILL REMAIN DRY THURSDAY BUT WILL KEEP A MENTION OF LIGHT SHOWERS OVER THE SRN PORTIONS OF THE FORECAST AREA THURSDAY AFTN. OVERALL SURFACE AND UPPER LVL RIDGING APPEARS TO MOVE SLOWLY BACK INTO THE STATE FRIDAY...SO WILL MENTION DRY CONDS INTO FRIDAY NIGHT. HIGH TEMPS SHOULD REMAIN IN THE 50S THURSDAY AND FRIDAY. SATURDAY...WILL MENTION A CHANCE OF SHOWERS OVER THE FORECAST AREA...AS A SURFACE TROUGH LINGERS OVER THE EASTERN LAKES...WHILE AN UPPER TOUGH MOVES OVER THE UPPER MIDWEST AND PLAINS FRIDAY NIGHT...AND INTO THE WRN LAKES REGION BY SATURDAY AFTERNOON. SWR && .APX WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING...ALL OF NORTHERN LOWER...SUNDAY AFTERNOON AND EARLY EVENING. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 100 PM EDT SAT APR 21 2007 .AVIATION... HIGH PRESSURE WILL SLIDE TOWARD THE EAST COAST TONIGHT. VFR CLEAR CONDITIONS WILL BE IN PLACE TODAY THROUGH SUNDAY MORNING OUTSIDE OF A STRAY PATCH OF CIRRUS. SOUTHERLY COMPONENT TO THE WINDS THIS AFTERNOON AND TONIGHT...AND GENERALLY LESS THAN 10 KNOTS. AT DET AND DTW...WINDS WILL HAVE AN EASTERLY COMPONENT AS WELL FROM LAKE BREEZES FROM LAKE ERIE AND ST. CLAIR. BY SUNDAY MORNING...STRONGER GRADIENT BUILDS INTO LOWER MICHIGAN AND EXPECT SSW WIND TO INCREASE TO 12 TO 17 KNOTS. && .PREV DISCUSSION...ISSUED 1030 AM EDT SAT APR 21 2007 UPDATE... NOT MUCH TO UPDATE...JUST SOME MINOR GRIDS EDITS. THOSE MINOR EDITS WERE TO BRING MORE LAKE BREEZE IN THE WIND GRIDS...AND LOWER THE DEW POINTS AWAY FROM THE LAKE SHORES. RUC SURFACE WINDS WERE MUCH BETTER THAN NAM IN REGARD TO THE LAKE BREEZE. LAKE BREEZE SHOULD BE ABLE TO PUSH IN ABOUT 10 TO 15 MILES TODAY GIVE THE SURFACE HIGH OVER THE REGION AND THE LAND/LAKE TEMPERATURE DIFFERENCE. THEN THE DEW POINTS WERE RUNNING ABOUT 5 DEGREES ON EITHER SIDE OF 30 NOW THAT WE HAVE STARTED TO MIX THIS MORNING. DO NOT EXPECT THAT TO CHANGE THROUGH MUCH OF THE DAY GIVEN 12Z SOUNDING AND WEAK SURFACE WIND. TEMPS IN GENERAL RUNNING ABOUT 4 TO 7 DEGREES ABOVE YESTERDAYS. 12Z SOUNDING MIXING TO 750 MB...WHICH WE DID YESTERDAY...WOULD YIELD ABOUT 74. ALL OF THIS RIGHT IN LINE WITH CURRENT FORECAST. SHORT TERM...TODAY AND TONIGHT THE ONLY VARIATION ON THE THEME OF IDEAL WEATHER IN SE MICHIGAN TODAY AND TONIGHT WILL BE THE GRADUAL EASTWARD DRIFT OF THE SURFACE RIDGE AXIS. THIS WILL ALLOW A LIGHT SOUTHERLY GRADIENT FLOW TO DEVELOP DURING THE AFTERNOON WHICH WILL HELP HIGH TEMPERATURES RISE ABOUT A CATEGORY OVER YESTERDAY, MEANING MID 70S OVER SE LOWER AWAY FROM THE SHORELINES OF THE GREAT LAKES. AS WAS THE CASE OVER THE LAST COUPLE OF DAYS, WE WILL TAILOR HIGH TEMPERATURES COOLER IN THOSE AREAS IMPACTED BY AN EASTERLY COMPONENT OF LAKE BREEZE. THE MOST DRAMATIC ADJUSTMENT WILL BE NEAR THE LAKE HURON SHORELINE WHERE UPPER 50S WILL BE ALL THAT IS EXPECTED AFTER A CHILLY START TO THE DAY. HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT AND INCREASE THE GRADIENT OVER SE MICHIGAN AS LOW PRESSURE DEVELOPS IN THE PLAINS. HOWEVER, THIS IS NOT EXPECTED TO RESULT IN MUCH OF AN INCREASE IN WIND SPEED AS STRONG DECOUPLING WILL OCCUR THROUGH THE NIGHT. THE RESULTING SLOW RETURN IN SURFACE MOISTURE WILL KEEP DEW POINT IN THE UPPER 30S AND ALLOW ANOTHER GOOD NIGHT OF RADIATIONAL COOLING. THAT BEING SAID, EVEN A 30 DEGREE DIURNAL SWING KEEPS READINGS IN THE LOWER TO MID 40S BY SUNRISE SUNDAY MORNING. LONG TERM... THE WARMEST DAY OF THE WEEK WILL OCCUR ON SUNDAY AS THE UPPER LEVEL RIDGE AXIS SLIDES JUST EAST OF THE CWA AND 850 MB TEMPS WARM INTO THE LOWER TEENS ALONG WITH AN INCREASING SOUTHWEST GRADIENT...LEADING TO MAXES IN THE MID TO UPPER 70S THROUGHOUT SOUTHEAST MICHIGAN UNDER MOSTLY SUNNY SKIES...AND POSSIBLY EVEN 80 DEGREES TOWARD THE TRI-CITIES REGION. EVEN SO...NOT PLANNING ON ISSUING A FIRE WX WATCH DUE TO THE RH EXPECTED TO REMAIN JUST ABOVE 25 PERCENT. 00Z NAM/GFS INDICATING SURFACE DEW POINTS CLIMBING INTO THE LOWER 50S. AFTER SUBTRACTING OUT THE MOIST LOW LEVEL BIAS OF THE MODELS (UP TO 10 DEGREES AS OBSERVED YESTERDAY)...STILL THINK IT WILL BE TOUGH TO MAINTAIN DEW POINTS BELOW 40 DEGREES WHICH WILL BE NEEDED TO SUPPORT RH`S AT OR BELOW 25 PERCENT. IT LOOKS TO REAL CLOSE CALL AND WOULD NOT TOTALLY RULE OUT A RED FLAG WARNING BEING NEEDED OVER MIDLAND/BAY/SAGINAW COUNTIES HOWEVER. GOOD AGREEMENT NOW WITH THE WEAKENING UPPER WAVE OVER FAR SOUTHERN CALIFORNIA TRACKING THROUGH THE CENTRAL GREAT LAKES ON MONDAY. INSTABILITY/MID LEVEL LAPSE RATES LOOK MARGINAL AND SUPPORT JUST A CHANCE OF THUNDERSTORMS LATE SUNDAY NIGHT INTO MONDAY. COLD FRONT EXPECTED TO BE SOUTH OF THE BORDER BY MONDAY EVENING...WITH NORTHWEST CONFLUENT FLOW AND GENERAL SUBSIDENCE OVERSPREADING LOWER MICHIGAN MONDAY NIGHT INTO TUESDAY...PER 00Z EUROPEAN. NORTHERN STREAM UPPER WAVE SLIDING OVER LAKE SUPERIOR TUESDAY EVENING WILL CAUSE 850-700 MB FGEN TO INCREASE ALONG WITH SIGNIFICANT MOISTURE TRANSPORT OVER SOUTHERN LOWER MICHIGAN...JUSTIFYING AT LEAST CHANCE POPS...HIGHEST POPS NEAR THE OHIO BORDER...CLOSER TO THE SURFACE BOUNDARY WHICH LOOKS TO RESIDE OVER THE NORTHERN OHIO VALLEY. THE 00Z GFS EVEN INDICATING THE SHOWALTER INDEX GOING NEGATIVE NEAR THE BORDER...AND HAVE ADDED A CHANCE OF THUNDERSTORMS ACROSS THE FAR SOUTH AS WELL. WILL ACCOUNT FOR THE POSSIBILITY OF SOME LINGERING SHOWERS ON WEDNESDAY AND TWEAK MAX TEMPS DOWN WITH THE NORTHEAST FLOW OFF LAKE HURON. OTHERWISE...NO CHANGES MADE BEYOND WEDNESDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION...RBP SHORT TERM...BT/RBP LONG TERM....SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1032 AM EDT SAT APR 21 2007 .UPDATE... NOT MUCH TO UPDATE...JUST SOME MINOR GRIDS EDITS. THOSE MINOR EDITS WERE TO BRING MORE LAKE BREEZE IN THE WIND GRIDS...AND LOWER THE DEW POINTS AWAY FROM THE LAKE SHORES. RUC SURFACE WINDS WERE MUCH BETTER THAN NAM IN REGARD TO THE LAKE BREEZE. LAKE BREEZE SHOULD BE ABLE TO PUSH IN ABOUT 10 TO 15 MILES TODAY GIVE THE SURFACE HIGH OVER THE REGION AND THE LAND/LAKE TEMPERATURE DIFFERENCE. THEN THE DEW POINTS WERE RUNNING ABOUT 5 DEGREES ON EITHER SIDE OF 30 NOW THAT WE HAVE STARTED TO MIX THIS MORNING. DO NOT EXPECT THAT TO CHANGE THROUGH MUCH OF THE DAY GIVEN 12Z SOUNDING AND WEAK SURFACE WIND. TEMPS IN GENERAL RUNNING ABOUT 4 TO 7 DEGREES ABOVE YESTERDAYS. 12Z SOUNDING MIXING TO 750 MB...WHICH WE DID YESTERDAY...WOULD YIELD ABOUT 74. ALL OF THIS RIGHT IN LINE WITH CURRENT FORECAST. && .PREV DISCUSSION...ISSUED 647 AM EDT SAT APR 21 2007 SHORT TERM...TODAY AND TONIGHT THE ONLY VARIATION ON THE THEME OF IDEAL WEATHER IN SE MICHIGAN TODAY AND TONIGHT WILL BE THE GRADUAL EASTWARD DRIFT OF THE SURFACE RIDGE AXIS. THIS WILL ALLOW A LIGHT SOUTHERLY GRADIENT FLOW TO DEVELOP DURING THE AFTERNOON WHICH WILL HELP HIGH TEMPERATURES RISE ABOUT A CATEGORY OVER YESTERDAY, MEANING MID 70S OVER SE LOWER AWAY FROM THE SHORELINES OF THE GREAT LAKES. AS WAS THE CASE OVER THE LAST COUPLE OF DAYS, WE WILL TAILOR HIGH TEMPERATURES COOLER IN THOSE AREAS IMPACTED BY AN EASTERLY COMPONENT OF LAKE BREEZE. THE MOST DRAMATIC ADJUSTMENT WILL BE NEAR THE LAKE HURON SHORELINE WHERE UPPER 50S WILL BE ALL THAT IS EXPECTED AFTER A CHILLY START TO THE DAY. HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT AND INCREASE THE GRADIENT OVER SE MICHIGAN AS LOW PRESSURE DEVELOPS IN THE PLAINS. HOWEVER, THIS IS NOT EXPECTED TO RESULT IN MUCH OF AN INCREASE IN WIND SPEED AS STRONG DECOUPLING WILL OCCUR THROUGH THE NIGHT. THE RESULTING SLOW RETURN IN SURFACE MOISTURE WILL KEEP DEW POINT IN THE UPPER 30S AND ALLOW ANOTHER GOOD NIGHT OF RADIATIONAL COOLING. THAT BEING SAID, EVEN A 30 DEGREE DIURNAL SWING KEEPS READINGS IN THE LOWER TO MID 40S BY SUNRISE SUNDAY MORNING. LONG TERM... THE WARMEST DAY OF THE WEEK WILL OCCUR ON SUNDAY AS THE UPPER LEVEL RIDGE AXIS SLIDES JUST EAST OF THE CWA AND 850 MB TEMPS WARM INTO THE LOWER TEENS ALONG WITH AN INCREASING SOUTHWEST GRADIENT...LEADING TO MAXES IN THE MID TO UPPER 70S THROUGHOUT SOUTHEAST MICHIGAN UNDER MOSTLY SUNNY SKIES...AND POSSIBLY EVEN 80 DEGREES TOWARD THE TRI-CITIES REGION. EVEN SO...NOT PLANNING ON ISSUING A FIRE WX WATCH DUE TO THE RH EXPECTED TO REMAIN JUST ABOVE 25 PERCENT. 00Z NAM/GFS INDICATING SURFACE DEW POINTS CLIMBING INTO THE LOWER 50S. AFTER SUBTRACTING OUT THE MOIST LOW LEVEL BIAS OF THE MODELS (UP TO 10 DEGREES AS OBSERVED YESTERDAY)...STILL THINK IT WILL BE TOUGH TO MAINTAIN DEW POINTS BELOW 40 DEGREES WHICH WILL BE NEEDED TO SUPPORT RH`S AT OR BELOW 25 PERCENT. IT LOOKS TO REAL CLOSE CALL AND WOULD NOT TOTALLY RULE OUT A RED FLAG WARNING BEING NEEDED OVER MIDLAND/BAY/SAGINAW COUNTIES HOWEVER. GOOD AGREEMENT NOW WITH THE WEAKENING UPPER WAVE OVER FAR SOUTHERN CALIFORNIA TRACKING THROUGH THE CENTRAL GREAT LAKES ON MONDAY. INSTABILITY/MID LEVEL LAPSE RATES LOOK MARGINAL AND SUPPORT JUST A CHANCE OF THUNDERSTORMS LATE SUNDAY NIGHT INTO MONDAY. COLD FRONT EXPECTED TO BE SOUTH OF THE BORDER BY MONDAY EVENING...WITH NORTHWEST CONFLUENT FLOW AND GENERAL SUBSIDENCE OVERSPREADING LOWER MICHIGAN MONDAY NIGHT INTO TUESDAY...PER 00Z EUROPEAN. NORTHERN STREAM UPPER WAVE SLIDING OVER LAKE SUPERIOR TUESDAY EVENING WILL CAUSE 850-700 MB FGEN TO INCREASE ALONG WITH SIGNIFICANT MOISTURE TRANSPORT OVER SOUTHERN LOWER MICHIGAN...JUSTIFYING AT LEAST CHANCE POPS...HIGHEST POPS NEAR THE OHIO BORDER...CLOSER TO THE SURFACE BOUNDARY WHICH LOOKS TO RESIDE OVER THE NORTHERN OHIO VALLEY. THE 00Z GFS EVEN INDICATING THE SHOWALTER INDEX GOING NEGATIVE NEAR THE BORDER...AND HAVE ADDED A CHANCE OF THUNDERSTORMS ACROSS THE FAR SOUTH AS WELL. WILL ACCOUNT FOR THE POSSIBILITY OF SOME LINGERING SHOWERS ON WEDNESDAY AND TWEAK MAX TEMPS DOWN WITH THE NORTHEAST FLOW OFF LAKE HURON. OTHERWISE...NO CHANGES MADE BEYOND WEDNESDAY. .AVIATION... HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER FOR AVIATION INTERESTS TODAY BUT LOSE ITS GRIP A BIT TONIGHT WHILE SLIDING TOWARD THE EAST COAST. VFR CLEAR CONDITIONS WILL BE IN PLACE TODAY THROUGH TONIGHT OUTSIDE OF A STRAY PATCH OF CUMULUS OR PATCH OF CIRRUS. LIGHT AND VARIABLE WINDS WILL DEVELOP A SOUTHERLY COMPONENT BY AFTERNOON AND REMAIN LESS THAN 10 KNOTS TONIGHT. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION...BT SHORT TERM...BT/RBP LONG TERM....SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 350 AM EDT SAT APR 21 2007 .SYNOPSIS... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG CENTERED OVER THE GRT LKS BTWN TROFS IN THE WRN ATLANTIC AND OVER THE W. SFC HI CENTER OVER LWR MI AND DRY/STABLE AIRMASS (PWAT 0.40 INCH E TO 0.60 INCH W) SHOWN ON LOCAL 00Z RAOBS BRINGING A TRANQUIL NGT TO THE FA. CLOSEST PCPN IS SOME SHRA/ TSRA MOVING THRU WRN MN WHERE PAIR OF SHRTWVS NOTED BY RUC ANALYSIS MOVING NE THRU THE NRN PLAINS ON THE WRN FLANK OF UPR RDG INTERACTING WITH HIER H85 DWPTS/LLJ AXIS/MORE SGNFT MSTR CNVGC/AXIS OF H7-5 LAPSE RATE AOA 8C/KM. HI CLD BLOWING DOWNSTREAM FM THIS CLUSTER OF CNVCTN MOVING TOWARD WRN LK SUP. A MORE POTENT SHRTWV NOTED OVER SRN CA MOVING THRU THE BASE OF THE WRN TROF. ANOTHER SHRTWV NOTED OVER BRITISH COLUMBIA. MAIN FCST CONCERNS TDAY INTO SUN WL BE FIRE WX. FOCUS THEN SHIFTS TO PCPN CHCS ASSOCIATED WITH INTERACTION BTWN SHRTWV NOW OVER SRN CA AND THE OTHER NOW IN BRITISH COLUMBIA. FOR TDAY...NAM F0 APPEARS TO HAVE VERY GOOD HANDLE ON SHRTWV STRUCTURE/STABILITY/MSTR OVER THE NRN PLAINS/UPR LKS...SO WL FOLLOW ITS GUIDANCE. THIS MODEL SHOWS UPR RDG REMAINING PRETTY MUCH IN PLACE TDAY DOWNSTREAM OF STRONGER HGT FALLS OVER THE WRN PLAINS ASSOCIATED WITH POTENT SYS LIFTING OUT OF THE DESERT SW. SFC HI CENTER PROGGED TO DRIFT S TO NEAR CLE BY 00Z...WITH STRENGTHING SLY FLOW (H925 WINDS INCRSG TO 30KT BY 00Z SUN) BTWN THIS HI AND FALLING PRES OVER THE NRN PLAINS INTO MN. SHARP RDG FCST TO DEFLECT WEAKER SHRTWVS NOW MOVING THRU THE NRN PLAINS MORE NNE VS E...SO NAM FCST SHRA STAYING TO THE W SEEMS RSNBL. GFS ALSO IS DRY. WL HOWEVER MAINTAIN LO CHC POPS OVER WRN LK SUP CLOSER TO AXIS OF HIER RETURNING H85 DWPTS/KINX THRU MN AND WHERE SOME DEEP LYR H85-3 QVECTOR CNVGC NOTED. THERE SHOULD BE QUITE A BIT OF MID/HI CLD OVER THE W WITH MORE SUNSHINE TO THE E DEEPER INTO DRIER AIRMASS. MIXING TO H8 ON NAM FCST SDNGS YIELDS MAX TEMPS RISING TO ARND 73 OVER THE W...WITH DWPT ARND 40 (RH 30 PCT). AIRMASS WL REMAIN DRIER OVER THE E BUT TEMPS WL BE LOWER DOWNWIND OF LK MI. WL ISSUE WILDFIRE POTENTIAL STATEMENT TO STRESS NEAR CRITICAL FIRE WX PARAMETERS. TNGT...SHRTWV LIFTING OUT OF THE DESERT SW PROGGED TO REACH KS BY 12Z SUN WHILE SYS OVER BRITISH COLUMBIA FCST TO APRCH LK WINNIPEG. GUIDANCE SHOWS UPR RDG AXIS SHIFTING E A TAD...BUT GFS/NAM INDICATE ALL OF LAND FA WL REMAIN DRY WITH FCST SDNGS SHOWING A CAPPED WARM SECTOR. WL INCLUDE CHC SHRA/TSRA OVER WRN/NRN LK SUP AS SHRTWS MOVING ARND RDG AXIS PASS NW OF THE FA AND INTERACT WITH AXIS OF HIER H85 DWPT CLOSER TO EDGE OF CAP. GFS/NAM FCST H925 WINDS ARND 40KT ON WRN FLANK OF SFC HI MOVING INTO THE MID ATLANTIC...SO LOOK FOR RELATIVELY LTL DIURNAL DROP IN TEMP EVEN WHERE SKIES ARE MORE CLR OVER THE SCNTRL AND E. MIN TEMPS IN THE DOWNSLOPE AREAS FM IWD-P59-MQT-P53 WL NOT FALL BLO 50. GOING FCST LOOKS TO HAVE GOOD HANDLE ON PATTERN OF LO TEMPS...BUT BUMPED UP EXPECTED TEMPS IN DOWNSLOPE AREAS TOWARD HI END OF MOS GUIDANCE. NUMERICAL GUIDANCE IN GOOD AGREEMENT SHOWING SHRTWV LIFTING NEWD INTO THE UPR MS VALLEY BY 00Z MON AND WEAKENING AS SYS MOVES AWAY FM LARGER SCALE WRN TROF. MEANWHILE...OTHER SHRTWV MOVING ACRS SRN CAN PROGGED TO MOVE INTO NW ONTARIO LATE IN THE DAY. AS SHRTWVS CLOSE IN ON THE FA AND DEEP LYR H85-3 QVECTOR CNVGC ARRIVING IN THE AFTN... MODELS SHOW SUBSTANTIAL CAPPING OVER THE NW ERODING BTWN 18Z-24Z. GFS IS PARTICULARLY AGGRESSIVE AT MOISTENING THE ATMOSPHERE AND GENERATING QPF OVER THE W. CONSIDERING THE DRY AND CAPPED ANTECEDENT AIRMASS AND THE VERY LATE ARRIVAL OF THE MORE SGNFT DYNAMICS WITH THE SHRTWV PAIR REMAINING OUT OF PHASE...PREFER THE SLOWER NAM. THIS MODEL GENERATES ONLY A FEW HUNDREDTHS OF AN INCH AT IWD BEFORE 00Z MON. THE UKMET IS ALSO SLOWER TO SATURATE THE AIR OVER THE FAR W AS WELL. LARGE SCALE ACYC H85 FLOW FCST AHEAD OF THE SHRTWV COMPLEX... SO PCPN IS LIKELY TO HOLD OFF UNTIL THE SFC FNT ACCOMPANYING THE ONTARIO SHRTWV PASSES AND FAIRLY SHARP H85-7 FGEN ARRIVES SUN EVNG...WL KEEP THE LAND FA DRY ON SUN. FARTHER E...PCPN ON SUN IS A NON ISSUE WITH CAPPED ENVIRONMENT ALL DAY. MIXING TO H825 OR SO ON NAM FCST SDNGS IN THE WARM SECTOR SUG HI TEMPS WL APRCH 80 AWAY FM THE MODERATING INFLUENCE OF LK MI. SINCE RELATIVELY DEEP MIXING WL ALSO TAP DRIER LYR FCST ARND H85...DWPTS COULD MIX OUT INTO THE MID-UPR 30S IN THE AFTN OVER THE E AND DROP THE RH TOWARD 25 PCT IN AREAS THAT ESCAPE SGNFT COOLING DOWNWIND OF LK MI. SFC LO/LO PRES TROF ASSOCIATED WITH SHRTWV MOVING UP FM THE UPR MS VALLEY PROGGED TO REACH THE SRN ZNS BY 12Z MON WHILE SFC COLD FNT ACCOMPANYING SHRTWV MOVING ACRS ONTARIO REACHES THE CNTRL ZNS PER PREFERRED NAM/UKMET. PRETTY MUCH MAINTAINED GOING FCST OF LIKELY POPS ADVANCING W-E WITH THESE FEATURES. SINCE MODELS CONSISTENTLY SHOW PAIR OF SHRTWVS REMAINING OUT OF PHASE...SUSPECT ACCOMPANYING SHRA WL NOT BE TOO HEAVY WITH FAIRLY HEALTHY H85-7 FGEN BEHIND NRN BRANCH COLD FNT TENDING TO STAY FARTHER N. FCST SDNGS SHOW RATHER UNIMPRESSIVE LAPSE RATES...SO CALLED PCPN LIKELY -SHRA WITH JUST A CHC T. SINCE EVEN THE SLOWER NAM/UKMET BRING MUCH DRIER E INTO THE FA ON MON AFTN...CUT POPS W-E FASTER THAN PREVIOUS FCST. GFS SHOWS NEXT SHRTWV LIFTING OUT OF THE SW FARTHER N TOWARD THE UPR MIDWEST ON TUE WITH SOME LGT QPF OVER THE SRN TIER. UNTIL GUIDANCE COMES INTO BETTER AGREEMENT...FOLLOWED THE MORE CONSISTENT ECMWF/CNDN MODELS... WHICH SHOW THIS SYS/HIER RH REMAINING FARTHER S. SO NO CHGS MADE TO DRY TUE FCST. COORDINATED WITH APX/GRB. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 1119 AM CDT SUN APR 22 2007 .UPDATE... HAD TO UPDATE ONCE AGAIN TO INCREASE TEMPS EVEN HIGHER. AT 11 AM...READINGS AHEAD OF THE SFC FRONT WERE IN THE UPPER 60S AND LOWER 70S...ALREADY A FEW DEGREES ABOVE MOS/MAV GUIDANCE. IN CREASING CLOUDS IN THE NEXT FEW HOURS WILL HOLD TEMPS IN THE LOWER 70S THIS AFTERNOON. MEANWHILE...ON THE BACKSIDE OF THE FRONT 60S WILL PREVAIL. THIS INCREASED HEATING AND SLOWER PROGRESSION OF THE FRONT THIS MORNING WILL PLAY A SIGNIFICANT ROLE IN THE SEVERE WEATHER THREAT THIS AFTERNOON. CURRENTLY HAVE POOR CONFIDENCE IN MODEL CAPE/INSTABILITY VALUES THIS AFTERNOON...DUE TO WARMER SFC TEMPS THAN FCST...STALLED FRONT...AND POOR HANDLING OF YESTERDAY AND LAST NIGHTS DEVELOPMENT. SUSPECT RUC/NAM ARE UNDERESTIMATING INSTABILITY/CAPE THIS AFTERNOON. ALTHOUGH SFC DEW POINT DEPRESSIONS IN NW WIS ARE INCREASING AND RANGE 20 TO 25 DEGREE SPREADS. ELEVATED STORMS WITH LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN THREAT LATER THIS AFTERNOON AND EVENING. && .PREV DISCUSSION... /ISSUED 957 AM CDT SUN APR 22 2007/ UPDATE...ADJUSTED SKY COVER...TEMPS...AND MORNING POPS TODAY. CURRENT ASOS/RAWS OBSERVATIONS AND ANALYSIS PLACES THE SFC CYCLONE IN THE CENTRAL PLAINS...WITH A NEWRD EXTENDING FRONT POSITIONED THROUGH SW MN...NE INTO NC MN. VIS SAT IMAGERY SHOWS A LOW CLOUD DECK ALONG AND NORTH OF THE FRONT...WHILE MOSTLY SUNNY TO PARTLY CLOUDY SKIES ARE FOUND AHEAD OF IT. THE CLOUDS WILL INCREASE FROM NW TO SE AS THE FRONT PUSHES OVER THE NW HALF OF THE FA TODAY. INCREASED MAX TEMPS TODAY A FEW DEGREES IN WI ZONES WHERE THEY WILL SEE PLENTY OF SUN BEFORE THE FRONT ARRIVES THIS EVENING. TEMPS AT 9 AM IN NW WIS WERE ALREADY IN THE MID TO UPR 60S. ALTHOUGH THE SLIGHT RISK AREA DEFINED BY THE SPC WAS SHIFTED SOUTH AND OUT OF THE DLH CWA...MUCH OF THE NORTHLAND CAN STILL EXPECT TO SEE TSTMS THIS AFTERNOON AND EVENING...AND A FEW WILL HAVE THE POTENTIAL TO BECOME SEVERE. EARLY MORNING ACCUS SEEN NW OF DULUTH IMPLIES THERE IS INSTABILITY TO TAP LATER TODAY AS THE FRONT APPROACHES. ATTM...THE FAVORED TIME FRAME AND LOCATION FOR STORM DEVELOPMENT WILL BE BETWEEN 20Z AND 22Z...ALONG AND JUST AHEAD OF THE SFC FRONT. A STRONG SW MEAN WIND WILL RESULT IN NE TRACKING STORMS...ALL SHIFTING TO THE SE WITH THE FRONT. EXPECT THE TSTMS TO CONTINUE INTO THE EVENING HOURS...AND POTENTIALLY TRANSITIONING INTO HEAVY RAIN IN NW WISCONSIN LATE TONIGHT. PREV DISCUSSION... /ISSUED 348 AM CDT SUN APR 22 2007/ DISCUSSION...SHOWERS AND THUNDERSTORMS ACROSS MINNESOTA CONTINUE TO DECREASE IN COVERAGE AND INTENSITY EARLY THIS MORNING. HOWEVER THERE IS MORE RAIN APPROACHING OUR WRN ZONES FROM THE SOUTHWEST. THEREFORE WILL KEEP LIKELY POPS GOING ACROSS OUR WRN AND NRN ZONES THIS MORNING...WITH ONLY CHANCE POPS FARTHER SOUTHEAST. THE DECREASE IN PRECIPITATION MAY ALSO TRANSLATE TO A DECREASE IN CLOUD COVER THIS MORNING...ALLOWING FOR PARTIAL SUNSHINE AND IN TURN INCREASED SENSIBLE HEATING WHICH SHOULD HELP DESTABILIZE THE ATMOSPHERE BY THIS AFTERNOON. THE NAM HAS MUCAPE VALUES INCREASING TO BETWEEN 500-1000 J/KG...WHILE 0-3KM SRH VALUES WILL RANGE FROM 100 TO 200 M2/S2. THIS COMBINATION IS NOT SIGNIFICANT BY ANY MEANS...BUT IT SHOULD BE SUFFICIENT FOR THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS MUCH OF OUR FCST AREA THIS AFTERNOON AND EVENING...ALONG WITH ISOLATED SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HALF OF OUR CWA. ALL OF THIS ACTIVITY WILL BE INITIATED BY A COLD FRONT THAT IS PROGGED TO TRACK EAST ACROSS OUR CWA TODAY AND THIS EVENING. IN ADDITION...THERE WILL ALSO BE LARGE SCALE ASCENT ASSOCIATED WITH AN UPPER LEVEL TROUGH PROPAGATING EAST ACROSS THE MIDWEST. THE FRONT SHOULD QUICKLY MOVE OVER NWRN WI BY EARLY THIS EVENING...THEN EXIT EAST OF OUR CWA BY MIDNIGHT TONIGHT. WITH THE LOSS OF DAYTIME HEATING...AND COOLING FROM THE PRECIP...INSTABILITY SHOULD DECREASE FAIRLY QUICKLY TONIGHT...DECREASING THE POTENTIAL FOR THUNDERSTORMS AND SEVERE WEATHER. BY MONDAY MORNING...ONLY SCATTERED SHOWERS SHOULD LINGER ACROSS NWRN WI AS THE FORCING MOVES WELL TO THE EAST...AND HIGH PRESSURE BUILDS SOUTH FROM CANADA. THE HIGH WILL LINGER OVER THE UPPER MIDWEST THROUGH MIDWEEK...RESULTING IN MAINLY DRY CONDITIONS FOR THE NORTHLAND. && POINT TEMPS/POPS... DLH 73 41 57 36 / 60 60 10 10 INL 61 36 56 30 / 50 10 10 10 BRD 71 41 60 37 / 70 50 10 10 HYR 76 46 62 35 / 40 70 20 10 ASX 74 44 57 35 / 50 70 20 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ GRANING mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 129 AM CDT SUN APR 22 2007 .UPDATE... UPDATE FORECAST TO REMOVE SEVERE THUNDERSTORM WATCH AND REFRESH GRIDS. LITTLE CHANGE TO PREVIOUS FORECAST SHORT TERM...AS BEST SEVERE POTENTIAL APPEARS TO BE OVER. LOCALLY HEAVY RAIN ON FAR WESTERN PERIPHERY OF CWA THROUGH THE NEXT FEW HOURS. OTHERWISE TREND OF LATEST RUC 13 AND 4 KM WRF REFLECTIVITY TRENDS SHOW WEAKENING TREND AS UPPER JET TRANSLATES A BIT FARTHER NORTH AND EAST. && .PREV DISCUSSION... /ISSUED 300 PM CDT SAT APR 21 2007/ DISCUSSION... REMNANTS OF MORNING CONVECTION HAVE PRETTY MUCH LIFTED OUT OF AREA WITH ONE AREA OF REMAINING THUNDERSTORMS ACROSS E TWIN CITIES METRO INTO W WI. THESE SHOULD PRETTY MUCH BE OUT OF AREA BY 6 PM. GOOD MIXING IN S MN HAS ALLOWED FOR SOME GUSTS TO AROUND 40 MPH. WILL LEAVE WIND ADVISORY ACROSS SC MN UNTIL 8 PM THIS EVENING. MAIN FOCUS FOR THUNDERSTORMS TONIGHT WILL BE IN WC MN WHERE AXIS OF ELEVATED INSTABILITY IN PLACE. BY 06Z RATHER STRONG UPPER DIVERGENCE IN RIGHT ENTRANCE REGION OF UPPER JET COMES INTO PLAY PROVIDING A GOOD LIFTING MECHANIZM. CONTINUED TO CARRY A POPS ACROSS CENTRAL MN LATE TONIGHT DUE TO CONTINUED STRONG SOUTHERLY FLOW AND ANOTHER PUSH OF WARM ADVECTION. STREAM OF MOISTURE WILL CONTINUE TO LIFT INTO AREA INTO TOMORROW AHEAD OF STRONG UPPER TROF WITH PWATS OVER 1.25 INCH. FEEL THAT MAIN WEATHER THREAT WITH THIS SYSTEM SUNDAY WILL PROBABLY BE HEAVY RAINS WITH SOME HAIL WITH HIGH PWATS AND CONTINUED STRONG FORCING KEEPING AREA MAINLY CLOUDY. VERY MILD TEMPERATURES TONIGHT WILL CONTINUED MODERATE SOUTH FLOW AND INCREASING DEWPOINTS AHEAD OF COLD FRONT. LEFT THE CHANCE OF SHOWERS IN FOR SOUTHERN AREAS TUESDAY INTO WEDNESDAY AS NEXT SYSTEM MOVES THROUGH THE CENTRAL PLAINS...BUT CONFLUENT FLOW ACROSS CENTRAL MN SHOULD LIMIT THE NORTHWARD PROGRESS OF PRECIPITATION. MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND ADVISORY UNTIL 8 PM CDT THIS EVENING OR BLUE EARTH-BROWN-FARIBAULT-FREEBORN-MARTIN-REDWOOD- STEELE-WASECA-WATONWAN-YELLOW MEDICINE COUNTY(IES). WI...NONE. $$ && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ DWE/JPR mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 304 PM CDT SAT APR 21 2007 .DISCUSSION... SHOWERS AND THUNDERSTORMS PERSISTED TODAY ALONG A THERMAL AXIS FROM THE ARROWHEAD...TO THE TWIN PORTS...AND SOUTH ALONG THE I-35 CORRIDOR. ALTHOUGH THE TSTMS BECAME LESS WIDESPREAD IN THE AFTERNOON HOURS. A STRONG SW LL FLOW ALLOWED FOR THE STORMS TO MOVE VERY QUICKLY TO THE NNE AT 40 TO 45 KT. ALTHOUGH NO WIND DAMAGE WAS REPORTED WITH THE FAST MOVING STORMS...PLENTY OF HALF INCH HAIL ACCOMPANIED THESE CELLS. THE THERMAL RIDGE HAS DRIFTED ABOUT 30 MILES EAST FROM THIS MORNING AND IS NOW ALONG A LINE FROM BAYFIELD TO RICE LAKE...AND INTO THE ERN TWIN CITIES METRO. THE RUC ALSO SHOWS THIS REGION IS CO-LOCATED WITH A NARROW AREA OF MAX ISENTROPIC LIFT AS WELL AS BOUNDARY LAYER MASS CONVERGENCE. THESE FAST MOVING SHOWERS AND THUNDERSTORMS WITH SMALL HAIL WILL CONTINUE TO TRACK NE ALONG THE THERMAL RIDGE IN NW WIS THIS EVENING...DIMINISHING AFTER SUNSET. FORECAST FOCUS TURNING TO THUNDERSTORMS OVERNIGHT AS ON SUNDAY AS A LOW PRESSURE SYSTEM AND DEVELOPING COLD FRONT AFFECT THE REGION. SOME OF THE STORMS COULD BE SEVERE SUNDAY AFTERNOON IN NORTHERN WISCONSIN. OVERNIGHT...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AS A 50 KT SW LLJ ENTERS THE ERN HALF OF THE CWA. THE FOCUS FOR ACTIVITY OVERNIGHT AND SUNDAY MORNING WILL BE ALONG A STRONG THERMAL BOUNDARY AHEAD OF COLD FRONT IN WRN AND NRN MN. MINOR CHANGES TO POPS OVERNIGHT. ALTHOUGH NAM/GFS ARE IN SIMILAR AGREEMENT WITH THE PLACEMENT OF THE FRONT AND THE MAX QPF OVERNIGHT...THE GFS IS STRONGER AND DEEPENS THE SFC FRONT INTO A 998 LOW IN NC MN BY SUNDAY MORNING. DUE TO THE POOR HANDLING OF THE LINE OF STORMS TODAY...SIGNIFICANT FURTHER SE THAN MODELS DEPICTED...DECREASED CONFIDENCE IN THE MODELS PLACEMENT OF THE QPF OVERNIGHT. TOMORROW...THE COLD FRONT WILL PUSH SE ACROSS NW MN SUNDAY MORNING...DECREASING THE CHANCE FOR ADDITIONAL TSTMS BEHIND IT. MUCH DRIER AIR AND CAA WILL FILTER INTO NW MN BY SUNDAY AFTERNOON. THE EXTEND OF THE DRY AIR IS STILL SOMEWHAT UNCERTAIN...BUT THE GFS AND NAM ARE BRINING IT FURTHER SE INTO THE CWA BY SUNDAY AFTERNOON. THIS DRY AIR WILL DECREASE THE CHANCE FOR THE NW THIRD OF THE CWA TO SEE ANY STORMS SUNDAY AFTERNOON AND EVENING. THE MODELS ARE ALSO TRENDING WITH A FASTER FROPA SUNDAY AND SUNDAY NIGHT. ADJUSTED POPS TO REFLECT THEES TRENDS. STORMS ARE LIKELY TO FIRE SUNDAY AFTERNOON AND EVENING...GENERALLY ALONG AND SOUTH OF A LINE FROM CASS LAKE...TO HIBBING...AND INTO THE MN ARROWHEAD. THE STRONGER STORMS ARE EXPECTED ACROSS ALL OF WI AND INTO SW MN...WHERE THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS. MUCAPE VALUES SUNDAY AFTN/EVEN ARE EXPECTED TO MAX OUT BETWEEN 1000 AND 1500 J/KG...WHILE 0-3KM SRH VALUES ARE PROGGED TO RANGE FROM 100-200 J/KG...WHICH SHOULD BE SUFFICIENT FOR THE DEVELOPMENT FOR ISOLATED SEVERE THUNDERSTORMS. REFER TO THE THE DAY TWO SPC OUTLOOK FOR FURTHER DETAILS. THE FRONT WILL MOVE EAST OF OUR FA SUNDAY NIGHT...ALTHOUGH SOME SHOWER ACTIVITY SHOULD LINGER ACROSS OUR ERN ZONES THROUGH MONDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE UPPER MIDWEST MONDAY AND MONDAY NIGHT...RESULTING IN A DRYING TREND. TEMPERATURES WILL REMAIN ABOVE NORMAL THIS WEEKEND...WITH COOLER TEMPS THEN EXPECTED FOR NEXT WEEK ASSOCIATED WITH THE AFOREMENTIONED HIGH PRESSURE SYSTEM FROM CANADA. && POINT TEMPS/POPS... DLH 47 64 41 57 / 30 70 70 10 INL 49 62 37 49 / 70 60 10 10 BRD 55 65 43 62 / 40 70 70 10 HYR 55 71 44 60 / 10 60 80 10 ASX 53 70 42 57 / 10 70 70 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ GRANING mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 915 AM CDT SAT APR 21 2007 .UPDATE... A LINE OF SHOWERS AND THUNDERSTORMS HAS SHIFTED EAST WHILE THE STORM TRACK TO THE NNE. THE LINE OF STRUMS EXTENDS FROM ELY...SOUTH THROUGH THE TWIN PORTS...AND ALONG THE I-35 CORRIDOR INTO THE TWIN CITES. RUC 925MB WINDS ALONG AND AHEAD OF THE LINE ARE UPWARDS OF 30KT FROM THE SOUTH...WITH A NOSE OF MAX H850 TEMPS AND WAA FEEDING INTO THE LINE OF STORMS. AT 9 AM...SMALL HAIL OF 1/4 INCH WAS REPORTED IN HINCKLEY. INCREASED THE LIKELY TSTM POPS FURTHER EAST THIS MORNING. && .PREV DISCUSSION... /ISSUED 327 AM CDT SAT APR 21 2007/ DISCUSSION...A LINE OF SHOWERS AND THUNDERSTORMS...REMNANTS OF STRONGER THUNDERSTORMS OVER THE DAKOTAS...HAS FINALLY BEGUN TO AFFECT OUR WRN COUNTIES EARLY THIS MORNING. SOME GUSTY WINDS HAVE BEEN ASSOCIATED WITH STRONGER STORMS...BUT THESE GUSTS HAVE BEEN FAIRLY MODEST. WE EXPECT THESE LINE OF STORMS TO SLOWLY SPREAD TO THE EAST...HOWEVER IT IS MOST LIKELY THEY WILL NOT REACH THE TWIN PORTS DUE TO DRIER AIR BEING ADVECTED IN FROM THE EAST. WE WILL MENTION LIKELY POPS FOR TODAY ACROSS OUR WRN COUNTIES AND THE NORTHERN HALF OF SAINT LOUIS COUNTY AS BOTH THE GFS AND NAM FORECAST PRECIP IN THESE AREAS...WHICH IS ASSOCIATED WITH A FEW WEAK UPPER LEVEL VORTICITY MAXIMA LIFTING ACROSS THE NRN PLAINS. FOR TONIGHT...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AND CONTINUE TO AFFECT WRN AND NRN MINNESOTA WHERE LIFT ASSOCIATED WITH A DEVELOPING COLD FRONT WILL BE FOCUSED. THIS FRONT ALONG WITH A STRONGER UPPER LEVEL SHORTWAVE WILL BE THE MAIN FORECAST CONCERN THROUGH SUNDAY NIGHT AS THEY TRACK EASTWARD ACROSS OUR CWA...ESPECIALLY SUNDAY AFTERNOON AND SUNDAY EVENING WHEN THERE WILL BE A SLIGHT RISK FOR SEVERE THUNDERSTORMS. MUCAPE VALUES DURING THIS TIME FRAME ARE EXPECTED TO MAX OUT BETWEEN 1000 AND 1500 J/KG...WHILE 0-3KM SRH VALUES ARE PROGGED TO RANGE FROM 100-200 J/KG...WHICH SHOULD BE SUFFICIENT FOR THE DEVELOPMENT FOR ISOLATED SEVERE THUNDERSTORMS. THE FRONT WILL MOVE EAST OF OUR FCST AFTER MIDNIGHT SUNDAY NIGHT...ALTHOUGH SOME SHOWER ACTIVITY SHOULD LINGER ACROSS OUR ERN ZONES THROUGH MONDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE UPPER MIDWEST MONDAY AND MONDAY NIGHT...RESULTING IN A DRYING TREND. TEMPERATURES WILL REMAIN ABOVE NORMAL THIS WEEKEND...WITH COOLER TEMPS THEN EXPECTED FOR NEXT WEEK ASSOCIATED WITH THE AFOREMENTIONED HIGH PRESSURE SYSTEM FROM CANADA. && POINT TEMPS/POPS... DLH 63 49 63 41 / 60 30 70 70 INL 67 50 62 37 / 60 60 70 70 BRD 73 54 65 43 / 60 40 70 50 HYR 74 54 71 44 / 10 10 40 70 ASX 73 53 70 42 / 10 10 40 70 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ GRANING mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 430 AM CDT SUN APR 22 2007 .SHORT TERM...TODAY THROUGH MONDAY...ANOTHER WARM AND MOSTLY SUNNY DAY IS ON TAP TODAY AS HIGH PRESSURE AT THE SURFACE AND ALOFT CONTINUES TO DOMINATE OVER THE ARKLAMISS. LATEST SFC ANALYSIS HAS HIGH PRESSURE CENTERED OVER THE CAROLINAS. THE HIGH WILL DRIFT SOUTHEAST TODAY AND OFF THE GA/SC COAST MONDAY WHILE RIDGING WEST ACROSS THE GULF COAST STATES. THIS WILL MAINTAIN OUR SE TO S LOW LEVEL FLOW AND SERVE TO GRADUALLY INCREASE LOW LEVEL MOISTURE OVER OUR REGION. SATELLITE IMAGERY/RUC ANALYSIS EARLY THIS MORNING HAS THE LARGE UPPER RIDGE OVER THE EASTERN CONUS WITH THE RIDGE AXIS JUST EAST OF OUR CWA. ALSO NOTED WAS A NEARLY STACKED LOW MOVING OVER SW KANSAS. THIS LOW WILL BE DEFLECTED TO THE NE AS THE UPPER RIDGE SLOWLY SHIFTS EAST TODAY. SOME MID AND HIGH LEVEL CLOUDS WERE SEEN STREAMING EAST TOWARD OUR DELTA REGION FROM THE CONVECTION ASSOCIATED WITH THE LOW. THESE CLOUDS SHOULD THIN AS THEY MOVE INTO OUR AREA AND WILL DO LITTLE TO HOLD TEMPERATURES FROM PEAKING OUT NEAR 80 DEGREES AGAIN THIS AFTERNOON. AS THE LOW PRESSURE SYSTEM MOVES OFF TOWARD THE GREAT LAKES REGION TONIGHT THE TRAILING COLD FRONT WILL STALL WELL NORTHWEST OF OUR AREA NEAR THE OZARKS. ALTHOUGH NO PRECIPITATION ASSOCIATED WITH THE FRONT IS EXPECTED IN OUR AREA...MODELS CONTINUE THE SURGE OF MOISTURE NORTHWARD AHEAD OF THE FRONT. THIS WILL RESULT IN SOME STRATUS DEVELOPING OVER THE WESTERN HALF OF OUR CWA TOWARD MONDAY MORNING A POSSIBLY A FEW AFTERNOON SHOWERS IN THE WEST. PREVIOUS FORECASTS HAVE TRIMMED THIS SLIGHT CHANCE POPS BUT THE UKMET/GFS/NAM/NGM ALL GENERATE SOME LIGHT QPF IN OUR WESTERN ZONES MONDAY AND WL NOT IGNORE. BY MONDAY AFTERNOON SURFACE DEW POINTS ARE EXPECTED TO BE BACK INTO THE LOW TO MID 60S WITH PWS AROUND 1.3 INCHES. ALTHOUGH RIDGING ALOFT WL ACTUALLY BE STRENGTHENING SOME FROM THE WESTERN GULF AHEAD OF THE THE NEXT UPPER LOW THAT WILL BE NEARING THE FOUR CORNERS REGION...MODEL SOUNDINGS INDICATE THAT DAYTIME HEATING WL WEAKEN THE EXISTING CAP AND RESULT IN ENOUGH INSTABILITY TO PRODUCE A FEW SHOWERS BY LATE AFTERNOON. THIS SLIGHT CHANCE OF SHOWERS WILL OCCUR ALONG AND WEST OF THE MS RIVER. WITH THE ANTICIPATED CLOUD COVER MONDAY HAVE CUT A FEW DEGREES OFF MAX TEMPS IN THE WEST AND CENTRAL. LATEST MAV GUIDANCE MAX TEMPS WERE AMONG THE HIGHEST ENSEMBLE MEMBERS AS WELL. IT WILL STILL BE WARM WITH MOST SITES TOPPING OUT AROUND 80 DEGREES AGAIN. /22/ .LONG TERM...(MONDAY NIGHT THROUGH NEXT SUNDAY)... FORECAST IS A LITTLE TRICKIER FOR THE PERIOD FROM MONDAY NIGHT UP UNTIL WEDNESDAY WITH THIS FORECAST PACKAGE. PAST FEW FORECASTS WERE CONFIDENT WITH ENTIRELY DRY WEATHER OVER THIS PERIOD WHILE WE WAIT FOR AN ORGANIZED SYSTEM TO BRING THE REGION SHOWER AND THUNDERSTORM CHANCES BY WEDNESDAY. NOW MODELS SUGGEST THAT MOISTURE RETURN AND LOW LEVEL CONVERGENCE ALONG THE NORTHWEST EDGE OF THE ARKLAMISS COULD SPARK SOME SHOWERS (AND MAYBE A STORM OR TWO) TUESDAY AND TUESDAY NIGHT. MAV/MEX POPS STILL CUT SOME FOR THESE PERIODS OWING TO PROBABLE THERMAL CAPPING ISSUES...BUT A LITTLE PRECIP CANNOT BE RULED OUT BEFORE WEDNESDAY MORNING IN NORTHWEST MS...SOUTHEAST AR AND NORTHEAST LA. OTHERWISE...EXPECT MONDAY NIGHT THROUGH TUESDAY NIGHT TO BE FRAUGHT WITH BOUTS OF NIGHT TIME LOWER CLOUDS AND DAYTIME CUMULUS...BUT PARTLY CLOUDY OVERALL. TEMPERATURES WILL TREND MUCH WARMER WITH LOWS PRIMARILY RANGING FROM 60 TO 65 WITH HIGHS 80 TO 85. GFS GUIDANCE TEMPS LOOK DECENT IN THAT REGARD. BY WEDNESDAY A RATHER POTENT UPPER LEVEL DISTURBANCE WILL HEAD TOWARD THE MID AND LOWER MS VALLEYS WITH AN ASSOCIATED SURFACE FRONT MOVING INTO THE ARKLATEX. DEEP SOUTHERLY FLOW WILL TRANSPORT MOISTURE NORTH INTO THE REGION FROM THE GULF OF MEXICO...ALTHOUGH THE "QUALITY" OF MOISTURE RETURN IS NOT TOO IMPRESSIVE. SHOULD STILL BE ENOUGH JUICE AROUND TO TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS (MOST CONCENTRATED WEST) BY AFTERNOON AS ATMOSPHERIC FORCING INCREASES. PROGGED VALUES OF WIND SHEAR MEET THRESHOLDS FOR ORGANIZING STORMS INTO SEVERE MODES...BUT THE POSITIONING OF THE SURFACE LOW WILL NOT BE OPTIMUM FOR THE GENERATION OF SEVERE WEATHER. TAME LAPSE RATES WILL EQUATE TO MODEST INSTABILITY AT BEST (1000 TO 1500 JOULES) AND SHEAR COULD BE A LITTLE MUCH FOR STRUGGLING UPDRAFTS TO "KEEP UP WITH". THESE "CONS" FOR WIDESPREAD SEVERE WEATHER ARE ENOUGH FOR ME TO KEEP THE HWO CLEAR FOR NOW...BUT THERE STILL ARE SOME POSSIBILITIES OF INTENSE CONVECTION BEING AROUND WEDNESDAY AFTERNOON INTO THE WEDNESDAY EVENING IN THE AREA...SO STAY TUNED TO LATER FORECASTS. AS FOR POPS...GUIDANCE CAME IN WITH MAINLY 30 TO 50 PERCENT FOR WEDNESDAY AND WEDNESDAY NIGHT AND I FOUND ENOUGH EVIDENCE TO INCREASE 10 TO 15 POINTS IN NORTHWEST ZONES WEDNESDAY AND 10 POINTS NEARLY AREAWIDE WEDNESDAY NIGHT. EXPECT HIGHS WEDNESDAY IN THE UPPER 70S TO LOWER 80S (WHICH IS SEVERAL DEGREES WARMER THAN GUIDANCE) WITH LOWS MAINLY IN THE LOWER 60S...WHICH IS AGAIN WARMER THAN GUIDANCE. ANNOYING MODEL DISCREPANCIES CONTINUE AFTER WEDNESDAY NIGHT. LATEST GFS RUN HAS TRENDED COMPLETELY TO THE PREVIOUS EURO IDEA OF A STRONG FRONTAL PUSH THROUGH THE REGION THURSDAY WHILE THE EURO MODEL HAS BACKED OFF FROM THIS IDEA SOME. THE TREND OF THE EUROPEAN MODEL HAS BEEN MORE CONSISTENT THAN THE ERRATIC GFS...SO I HEDGED OUR FORECAST TOWARD THE FORMER MODEL. THAT HEDGING BASICALLY ENTAILS GOING WARMER THAN MEX GUIDANCE THURSDAY THROUGH FRIDAY NIGHT SINCE THE FRONT WILL LIKELY HANG UP NEAR THE SOUTHERN EDGES OF THE CWA. EXPECT LOWS TO DIP DOWN INTO THE 50S AGAIN FOR MOST LOCALES THURSDAY NIGHT...BUT THEN TREND SLOWLY BACK UPWARDS THROUGH SATURDAY AS THE FRONT MEANDERS BACK NORTH. HIGHS SHOULD DIP DOWN INTO THE 70S NORTHERN AREA THURSDAY AND FRIDAY FOLLOWED BY A RETURN TO WIDESPREAD 80S THEREAFTER. MODELS ARE REALLY ALL OVER THE PLACE WITH REGARDS TO ANOTHER...WEAKER...DISTURBANCE THAT MAY SLOWLY HEAD IN OUR DIRECTION NEXT WEEKEND. CONFIDENCE IS LOW AT THIS POINT THAT THIS FEATURE WILL BRING MUCH IN THE WAY OF PRECIP AND EVEN GFS GUIDANCE HAS COME DOWN SOME WITH THIS RUN IN TERMS OF POPS. WILL KEEP MENTION OF PRECIP OUT OF NEXT WEEKEND`S FORECAST FOR NOW. /BB/ && .AVIATION...MVFR CONDITIONS DUE TO VISIBILITY RESTRICTIONS 3-5SM WILL OCCUR OVER THE SOUTHERN HALF OF THE AREA THROUGH 14Z THIS MORNING. WINDS WILL PROVIDE ENOUGH MIXING TO HAMPER FOG DEVELOPMENT IN THE NORTH THIS MORNING. ALTHOUGH WIND GUSTS TO 15-20KTS ARE EXPECTED IN THE DELTA TODAY...VFR CONDITIONS EXPECTED TO PREVAIL AFTER 15Z ACROSS ALL TAF SITES TODAY. IFR TO LIFR CEILINGS ARE EXPECTED TO DEVELOP FROM THE SW TONIGHT REACHING MOST OF THE WESTERN HALF OF THE AREA BY 12Z. CEILINGS ARE EXPECTED TO BE AT OR BELOW 500FT AT ALL TAF SITES EXCEPT MEI AND GTR WHERE CEILINGS AROUND 1KFT CAN BE EXPECTED. /22/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 81 60 79 63 / 0 5 7 6 MERIDIAN 80 57 80 60 / 0 5 6 6 VICKSBURG 81 62 79 63 / 0 7 15 8 HATTIESBURG 80 59 81 63 / 0 4 8 4 NATCHEZ 80 62 79 65 / 0 5 15 7 GREENVILLE 81 62 79 65 / 0 12 15 12 GREENWOOD 80 61 79 64 / 0 8 15 12 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ SHORT TERM:22 LONG TERM: 50 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 430 AM CDT SAT APR 21 2007 .SHORT TERM...TODAY THROUGH SUNDAY...CONTINUED WARM AND DRY THIS WEEKEND AS HIGH PRESSURE SFC AND ALOFT DOMINATE OVER OUR REGION. WATER VAPOR IMAGERY/RUC ANALYSIS THIS MORNING SHOWS A FAIRLY AMPLIFIED PATTERN OVER THE CONUS WITH A WELL DEFINED LOW SPINNING OVER SOUTHERN CALIFORNIA AND A RATHER LARGE RIDGE OVER THE MS VALLEY. THE MID/UPPER RIDGE WILL SHIFT SLOWLY EAST ACROSS OUR CWA THIS WEEKEND AND DEFLECT THE LOW OVER SOUTHERN CALIFORNIA TO THE NORTHEAST OVER THE CENTRAL PLAINS. AT THE SFC...HIGH PRESSURE CENTERED OVER THE OHIO VALLEY THIS MORNING WILL MOVE SOUTHEAST OVER THE CENTRAL APPALACHIANS TODAY AND TO THE CAROLINA COAST BY SUNDAY AFTERNOON. THIS WILL RESULT IN OUR LOW LEVEL FLOW GRADUALLY VEERING FROM EASTERLY THIS MORNING TO SOUTHEASTERLY THIS AFTERNOON AND SOUTHERLY SUNDAY. LOW LEVEL MOISTURE WILL SLOWLY INCREASE AS A RESULT. PLENTY OF INSOLATION IS EXPECTED TODAY WITH LITTLE CLOUD COVER. THERE WILL BE A FEW MORE MID TO HIGH LEVEL CLOUDS AROUND SUNDAY FROM THE CONVECTION GENERATED TO OUR WEST ASSOCIATED WITH THE UPPER LOW. THIS WILL DO LITTLE TO PREVENT US FROM REACHING AFTERNOON MAX TEMPS A FEW DEGREES ABOVE NORMAL. AFTERNOON MAXIMUM TEMPERATURES WILL BE AROUND 80 DEGREES THIS AFTERNOON AND AGAIN SUNDAY. WITH CLEAR SKIES AND LIGHT WINDS EXPECTED AGAIN TONIGHT...SUNDAY MORNING LOWS WILL AGAIN BE A FEW DEGREES BELOW NORMAL...IN THE LOWER 50S AT MOST SITES. /22/ .LONG TERM...(SUNDAY NIGHT THROUGH NEXT SATURDAY)... GENERALLY UNEVENTFUL WEATHER SHOULD CONTINUE DURING THE SUNDAY NIGHT THROUGH TUESDAY PERIODS AS UPPER LEVEL RIDGING REMAINS THE PREDOMINANT INFLUENCE OVER THE ARKLAMISS. A DISTURBANCE PASSING OFF TO THE NORTH OF THE REGION LATE SUNDAY WILL LIKELY GENERATE SOME THUNDERSTORMS SUNDAY NIGHT NORTHWEST OF MY BORDERS...AND THEN DRAG A WEAK BOUNDARY SOMEWHAT CLOSE TO THE NORTHERN BORDERS OF THE FORECAST AREA THROUGH EARLY MONDAY. NOT ANTICIPATING ANY PRECIP TO GET INTO THE REGION WITH THIS SYSTEM...BUT RENEWED SOUTHERLY FLOW IN WESTERN ZONES WILL BRING A LITTLE MOISTURE NORTH FROM THE GULF. AFTER THIS SYSTEM...ALL THOSE LOOKING FOR RAIN WILL HAVE TO WAIT A FEW MORE DAYS FOR A MORE PROMISING DISTURBANCE SET TO SWING THROUGH LATE WEDNESDAY THROUGH THURSDAY. OPERATIONAL GFS MODEL HAS BEEN TRENDING WEAKER WITH THIS SYSTEM...TRYING TO DAMPEN IT SIGNIFICANTLY AS IT CROSSES OUR LONGITUDE. MEANWHILE...THE LATEST EUROPEAN MODEL RUN KEEPS THE SYSTEM MORE ROBUST THROUGH THE AXIS OF THE MID AND LOWER MISSISSIPPI VALLEYS. THE LATTER SOLUTION WOULD RESULT IN MORE PRECIPITATION A BETTER CHANCE OF STRONG CONVECTION. RIGHT NOW I`M LEANING ON THE EUROPEAN SOLUTION SINCE THAT MODEL HAS BEEN MORE CONSISTENT WITH THE HANDLING OF THIS SYSTEM AND HAS GENERALLY HAD MORE SKILL IN THE LONG-RANGE PORTION OF THE FORECAST LATELY. THOSE LOOKING TO AVOID DROUGHT SHOULD WISH FOR A GOOD SOAKING WITH THIS SYSTEM AND HOPEFULLY WE CAN AVOID SEVERE WEATHER. I AM STILL GOING TO LEAVE THE HWO CLEAR WITH REGARDS TO THE THIS SYSTEM FOR THE PRESENT TIME CONSIDERING QUESTION MARKS RELATING TO MOISTURE RETURN (AND ASSOCIATED INSTABILITY) AND OVERALL STRENGTH OF SYSTEM. THOSE UNCERTAINTIES SHOULD BE RESOLVED IN THE NEXT FEW DAYS. MODELS (SPECIFICALLY THE OPERATIONAL GFS AND OPERATIONAL EUROPEAN) DEVIATE EVEN MORE TOWARD THE END OF THE LONG TERM PERIOD. THE GFS SUGGESTS ANOTHER RATHER STRONG DISTURBANCE WILL MARCH ACROSS THE REGION AROUND SATURDAY...ACTIVATING THE BAROCLINIC ZONES LEFT IN THE WAKE OF WEDNESDAY/THURSDAY`S SYSTEM. THE END RESULT WOULD BE ANOTHER GOOD SHOT AT RAIN FOLLOWED BY A COOL SHOT. AT THE OTHER END OF THE SPECTRUM...THE EUROPEAN MODEL DOES NOT PHASE THIS DISTURBANCE LIKE THE GFS...INSTEAD LEAVING IT ABANDONED IN THE MIDDLE OF THE NATION. THAT SCENARIO WOULD LEAVE US WARM AND GENERALLY DRY THROUGH NEXT SATURDAY...ALTHOUGH SOME ISOLATED SHOWERS STILL COULD NOT BE RULED OUT GIVEN THE EXPECTATION OF A MEANDERING BOUNDARY IN THE VICINITY. BOTH MODELS HAVE BEEN CONSISTENT WITH THEIR RESPECTIVE SOLUTIONS THE PAST FEW DAYS AND VARIOUS OTHER MODELS AND ENSEMBLES ARE NOT HELPING TO RESOLVE DIFFERENCES MUCH. STILL HAVE TO HEDGE TOWARD THE EURO RIGHT NOW THOUGH...MAINLY BECAUSE ITS RECENT PERFORMANCE IN THE LONG RANGE HAS BEEN SUPERIOR. SO...AFTER A COOLER THAN AVERAGE APRIL THUS FAR WE CAN ANTICIPATE TEMPERATURES TO BE GENERALLY ABOVE AVERAGE THROUGH MOST OF THE REST OF THE MONTH. THAT EQUATES TO LOWS RANGING FROM THE UPPER 50S TO LOWER 60S WITH HIGHS RANGING MAINLY FROM 80 TO 85 DEGREES. THAT SAID...THE EURO MODEL DOES SUGGEST A BIT OF COOLING BEHIND THE COMING FRONT NEXT THURSDAY...BUT ANY SUB-80 DEGREE WEATHER WILL PROBABLY NOT LAST TOO LONG. GIVEN MY MENTIONED DISAGREEMENTS WITH THE OPERATIONAL GFS MODEL...IT IS NOT SURPRISING THAT I DEVIATED FROM GFS POP AND TEMP GUIDANCE A BIT THROUGH THE LONG TERM. FOR TEMPS...I GENERALLY WENT 1 TO 2 DEGREE WARMER THAN GUIDANCE FOR HIGHS (ESPECIALLY EAST) MONDAY THROUGH WEDNESDAY. FOR LOW TEMPS I CUT GUIDANCE A TOUCH SUNDAY AND MONDAY NIGHTS DUE TO DRY AIR IN PLACE...AND THEN AGAIN THURSDAY AND FRIDAY NIGHT SINCE I FEEL A LITTLE COOL AIR MAY WORK SOUTH INTO THE ARKLAMISS IN THE WAKE OF THE FRONTAL PASSAGE. AS FOR POPS...GFS GUIDANCE GENERATES SOME SPURIOUS LOOKING POPS MONDAY NIGHT THROUGH TUESDAY NIGHT WITH VERY MINOR IMPULSES EJECTING OUT OF THE APPROACHING LARGER DISTURBANCE. FEELING IS THAT GENERALLY STABLE AND CAPPED AIRMASS IN OUR AREA WILL NOT SUPPORT PRECIP DEVELOPMENT WITH THIS FORCING. DID LEAVE SOME SLIGHT POPS IN NORTHWEST ZONES TUESDAY NIGHT SINCE MOISTURE COULD GET SOMEWHAT DEEPER BY THAT TIME THERE. WENT WITH GFS POPS FOR WEDNESDAY...BUT UPPED THEM SOME 10 TO 15 POINT WEDNESDAY NIGHT WHEN MAIN IMPACT FROM THE SYSTEM LOOKS TO ARRIVE. PAST WEDNESDAY NIGHT I TRIMMED BACK POPS SOME THURSDAY THROUGH SATURDAY WITH RESPECT TO THE HEDGING TOWARD THE EURO MODEL THAT I MENTIONED ABOVE. /BB/ && .AVIATION...LIFR CONDITIONS DUE TO VISIBILITY RESTRICTIONS WAS BEING REPORTED AT KTVR THIS MORNING...BUT ONLY A BRIEF PERIOD OF MVFR CONDITIONS AROUND 12Z IS EXPECTED ELSEWHERE. VFR CONDITIONS WILL RESUME AREAWIDE BY 15Z AND PREVAIL THROUGH 06Z SUN. SOME SPOTTY MVFR CONDITIONS DUE TO VISIBILITY RESTRICTIONS WILL BE POSSIBLE 10-13Z SUNDAY. /22/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 80 53 80 57 / 0 0 0 2 MERIDIAN 78 50 80 51 / 0 0 0 0 VICKSBURG 81 53 82 59 / 0 0 0 6 HATTIESBURG 82 53 81 54 / 0 0 0 0 NATCHEZ 79 55 79 59 / 0 0 0 3 GREENVILLE 80 55 80 60 / 0 0 0 9 GREENWOOD 80 54 80 57 / 0 0 0 8 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ SHORT TERM:22 LONG TERM: 50 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 315 PM CDT SAT APR 21 2007 .DISCUSSION... STRONG SOUTHERLY SFC WINDS CONTINUE THIS AFTERNOON WITH A HANDFUL OF AWOS/ASOS STATIONS MEETING ADVISORY CRITERIA AS OF PUBLISHING TIME BUT EXPECT MORE SITES TO REACH CRITERIA LATE THIS AFTERNOON/EARLY THIS EVENING. EXPIRATION TIME ON WIND ADVISORY AT 7 PM MAY BE A FEW HOURS TOO EARLY...HOWEVER WILL JUST KEEP IT AS IS AND IF OBS ARE EXCEEDING CRITERIA AT THIS TIME...NEXT SHIFT CAN TAKE ANOTHER LOOK AT THE HEADLINE. FOCUS OVER NEXT 24 HOURS WILL BE COLD CORE UPPER LOW CURRENTLY OVER FOUR CORNERS REGION THAT WILL MOVE NEWD OVERNIGHT AND SLIDE OVER THE TOP OF THE FORECAST AREA SUN AFTERNOON. LATEST SUBJECTIVE SFC ANALYSIS SHOWS DEEPENING LOW PRES CENTERED OVR SERN CO WITH STRONG DRYLINE EXTENDING SWWD AND QUASI-STATIONARY FRONTAL BOUNDARY EXTENDING NEWD FM THE SFC LOW THRU FAR SWRN NEB AND INTO NCTNRL NEB AND CNTRL SD. MID TO UPPER 50S SFC DEWPOINTS COVER MUCH OF THE AIRMASS AHEAD OF THIS BOUNDARY...AS FAR EAST AS WRN IA. CONVECTION IS EXPECTED TO FIRE ALONG DRY LINE LATE THIS AFTERNOON/EARLY EVENING AND ALSO ALONG THE NEWD EXTENDING BOUNDARY...ONCE STRONG CAP EVIDENT ON LBF 18Z SOUNDING WEAKENS. A SERIES OF WEAK WAVES ARE FORECAST TO MOVE ALONG THIS BOUNDARY OVERNIGHT TO KEEP CONVECTION ONGOING AS IT SLOWLY MOVES EWD. QUESTION REMAINS AT HOW FAR EAST THE CONVECTION WILL REACH IF IT INDEED BOWS OUT AS FORECAST. SREF SPAGHETTI PLOTS AND 4KM NMM WRF SHOW THIS ACTIVITY WEAKENING SIGNIFICANTLY AS IT SPREADS INTO ERN NEB LATE TONIGHT. NOT EXPECTING ANY SVR TSTMS OVERNIGHT...BUT LIKELY SOME REMNANT SHOWERS AND ISOLATED TSTMS PASSING ON THROUGH. BY 12Z SUN...SHOWERS AND ISOLATED TSTMS WILL LIKELY BE ONGOING ALONG THE FRONTAL BOUNDARY AT THIS TIME ACROSS MUCH OF NWRN SECTIONS OF THE FORECAST AREA. APPROACHING SYSTEM SHOULD BE FAIRLY VERTICALLY STACKED AS SFC LOW MOVES ACROSS NWRN KS WITH 500MB COLD CORE LOW LAGGING SLIGHTLY BEHIND. 12Z RUC SEEMS TO HAVE A GOOD HANDLE ON CONCEPTUAL MODEL AND HAVE FOLLOWED MORE CLOSELY TO IT. SEVERE WEATHER POSSIBILITY EXISTS FROM BASICALLY LATE SUNDAY MORNING THRU THE AFTERNOON HOURS AS MUCAPE VALUES APPROACH 1000 J/KG BY THE LATE MORNING HOURS...MID LEVEL LAPSE RATES STEEPEN AS UPPER LOW APPROACHES AND BULK SHEER VALUES FORECAST AROUND 40-50KTS. ALSO...WITH -20C 500MB LOW CORE SLIDING DIRECTLY OVERHEAD EARLY AFTERNOON...CANNOT RULE OUT MINI SUPERCELL EVENT FOR THE LATE MORNING/EARLY AFTERNOON HOURS. ACTIVITY SHOULD SUBSIDE BY LATE AFTERNOON/EARLY EVENING AS SYSTEM MOVES INTO NRN IA BY 03Z. MONDAY LOOKS FAIRLY QUIET EARLY IN THE DAY WITH SHORTWAVE RIDGING AND SFC HIGH PRESSURE SLIDING OVER THE AREA. UPSTREAM...LEE CYCLONE DEVELOPS ACROSS CO AHEAD OF NEXT UPPER LOW DIGGING ACROSS THE DESERT SOUTHWEST. THIS PUSHES A WARM FRONT NORTH ACROSS KANSAS AND INTO SRN NEB LATE IN THE EVENING. MODERATE INSTABILITY AND A STRENGTHENING LOW LEVEL JET SHOULD HELP FEED ELEVATED CONVECTION ACROSS KANSAS AND SPREAD IT NWD AS 850MB FRONT SLIDES NWD INTO NEB OVERNIGHT. VERTICALLY STACKED LOW WL MOVE INTO WRN KS LATE MONDAY NIGHT AND ACROSS KANSAS THROUGHOUT THE DAY TUESDAY LEAVING 850MB FRONTAL BOUNDARY TO BISECT THE AREA THRU TUESDAY. SFC FNT ALSO NUDGES INTO FAR SERN CORNER OF NEB ON TUESDAY. EXPECT CONVECTION TO CONTINUE THROUGHOUT MUCH OF THE DAY ACROSS THE FORECAST AREA. BY LATE TUESDAY NIGHT...FORECAST AREA IS ON THE NORTH SIDE OF THE LOW AND SO HAVE TRANSITIONED OVER TO JUST RAIN SHOWERS AS REGION LIES IN DEFORMATION AREA. COULD SEE SOME HEAVY RAINFALL AMOUNTS. LONG RANGE ENSEMBLES COMING TO A CLOSER AGREEMENT THAT THERE WILL BE A MID LEVEL TROF ACROSS THE CENTRAL US BY LATE NEXT FRIDAY OR SATURDAY. HAVE ADDED A CHANCE POP IN FOR THIS. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ011-012-015>018- 030>034-042>045-050>053-065>068-078-088>090. IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ043-055-056-069. && $$ GRIFFIS ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 322 AM CDT SAT APR 21 2007 .DISCUSSION... EASTERN EDGE OF THE CONVECTION LIFTING NWD ACROSS NORTHERN NEBRASKA HAD WEAKENED AS IT MOVED ACROSS NWRN CWA EARLY THIS MORNING WITH THE ACTIVITY EXPECTED TO BE N OF THE CWA BY 12Z. THUS WILL RUN A DRY FORECAST FOR TODAY. LOW LEVEL JET FEEDING ACTIVITY AT 07Z WAS 60 KTS PLUS ON AVAILABLE NEBRASKA PROFILERS...ALTHOUGH WINDS FORECAST TO SUBSIDE THROUGH MIDDAY BEFORE INCREASING AGAIN BY THIS EVENING. SINCE 850 MB WINDS ARE FORECAST TO BE A BIT STRONGER THAN YDA...WHICH SAW A FEW LOCATIONS TOUCH WIND ADVSRY CRITERIA...STRONG MIXING AGAIN TODAY SHOULD BRING EVEN STRONGER WINDS. THUS...ISSUED A WIND ADVSRY FOR THIS AFTERNOON ALL BUT FAR SERN ZONES WHERE WINDS WERE JUST A BIT LIGHTER TILL 00Z. WITH LOW LVL JET CRANKING UP AGAIN TNGT...ADVSRY MAY NEED EXTENDING A BIT INTO THE EVENING IF SFC DOESN/T COOL ENOUGH PROVIDING A WEAK INVERSION. ALSO RAISED MOST TEMPS A FEW DEGREES DUE TO MILD START AND BASED HOW WARM IT GOT YDA. EXPECT CONVECTION TO AGAIN FIRE THIS AFTN NEAR DRY-LINE WRN NEBRASKA WITH ACTIVITY EXPECTED TO SHIFT FARTHER EAST BY SUNDAY MORNING. THUS SPREAD LIKELYS OVER WRN 2/3RDS IN 06Z-12Z PD. ALTHOUGH SURFACE BASED OR MIXED LAYER CAPE MODEST/WEAK BY 12Z SUN...LOW LEVEL JET WILL BE STRONG AND UPPER DYNAMICS DECENT AS UPPER LOW SHOULD BE MOVING ACROSS WRN KS BY THEN. THUS SOME SEVERE THREAT WILL LIKELY CONTINUE INTO SUNDAY MORNING WRN ZONES...AND POSSIBLY FARTHER EAST SUNDAY MORNING. WATER VAPOR IMAGERY SHOWED UPPER LOW STARTING TO TURN EWD NEAR NRN BAJA CALIFORNIA AS OF 08Z...PERHAPS A BIT SLOWER THAN 00Z GFS BASED ON LATEST RUC INITIALIZATION. HOW FAST UPPER LOW LIFTS OUT STILL SOMEWHAT IN QUESTION WITH UKMET/ECMWF AND CANADIAN A BIT SLOWER THAN AMERICAN MODELS. WILL CONTINUE TO LEAN TOWARD A SLIGHTLY SLOWER SOLUTION...WHICH COULD ALLOW READINGS SUNDAY TO REACH OR EXCEED 70 AS FAR NW A LNK TO OMA LINE WITH STRONG TO SEVERE CONVECTION REDEVELOPING...IF IT EVEN SUBSIDES...IN THE AFTN NEAR AND EAST OF THE MO RIVER. ACTIVITY SHOULD QUICKLY MOVE EWD THOUGH BY EARLY EVENING WITH A DRY FORECAST THEN THROUGH MON AFTN. DID INCREASE POPS MONDAY NIGHT INTO THE TUESDAY NIGHT PERIOD AS DECENT AGREEMENT AMONG MODELS WITH NEXT UPPER LOW LIFTING A WARM FRONT TOWARD AND POSSIBLY INTO SRN ZONES. NOTICED 00Z ECMWF AND GFS WERE MORE PROGRESSIVE WITH THIS NEXT UPPER LOW/TROUGH AND IF THIS TREND WOULD CONTINUE...POPS MAY NEED LOWERING/DROPPED IN WED NGT/THU PD IN FUTURE FORECASTS. MADE LITTLE/NO TEMP CHANGES TO MONDAY AND BEYOND. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR NEZ011-012-015>018-030>034-042>045-050>053-065>068-078- 088>090. IA...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR IAZ043-055-056-069. && $$ CHERMOK ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 232 PM MDT SAT APR 21 2007 .DISCUSSION... CURRENT FORECAST PACKAGE PRETTY MUCH GOING AS EXPECTED WITH SURFACE OBSERVATIONS AND SATELLITE IMAGERY SHOWING MAIN UPPER LEVEL LOW CORE ENTERING CWFA. MUCH OF THE ACTIVITY THROUGH THE REST OF THE AFTERNOON INTO THE EVENING WILL BE A COMBINATION OF SYNOPTICALLY AND CONVECTIVELY DRIVEN. LOOK FOR A LOT OF THE ACTIVITY TO DIE DOWN TOWARDS SUNSET ACROSS MOST OF THE FORECAST AREA WITH SOME RESIDUAL DYNAMICS ACROSS THE NORTH CENTRAL MOUNTAINS AND PERHAPS FAR NORTHEAST PLAINS DEPENDING ON DRY LINE ACTION. WILL HOLD SERVE ON THE WIND ADVISORY AND LET IT GO THROUGH 8 PM. SIERRA BLANCA AND AN OBSERVER HAS ALREADY VERIFIED THE HIGH WIND WARNING IN LINCOLN COUNTY HOWEVER WINDS HAVE ABATED SOMEWHAT THERE. SUSPECT ANOTHER BURST WITH THE BL/700MB WIND FRONTAL PASSAGE SO WILL LET THAT CONTINUE ALTHOUGH WILL BE LIMITED. A COUPLE OF OTHER OBSERVATION SITES TO THE LEE OF THE CENTRAL MOUNTAINS COULD ALSO HIT HIGH WIND WITH THE FROPA BUT NOT AS MUCH CONFIDENCE. CONVECTIVE SHOWER ACTIVITY WILL TEND TO MUDDLE UP ADVISORY AND HIGH WIND WARNING SPEEDS. PRETTY MUCH CONTINUED WITH INHERITED POP PACKAGE FOR TONIGHT WITH MOST OF THE ACTIVITY DYING DOWN BETWEEN 6 TO 8 PM. ALL ACTIVITY DISSIPATED AFTER MIDNIGHT. LESS CONFIDENCE FOR FOG DEVELOPMENT AFTER THE DEPARTING LOW ACROSS THE NC MOUNTAINS SO WILL LEAVE IT OUT. EVENING SHIFT CAN RELOOK AT THAT...DEPENDING ON HOW MUCH PRECIPITATION ENDS UP FALLING. LASTLY...SEVERE WEATHER MOST PROBABLE ACROSS UNION COUNTY AS DRY LINE MIXES EASTWARD. IT APPEARS THAT THE NAM/RUC HAVE A BETTER HANDLE ON THE MSLP SURFACE LOW THAN THE GFS BUT THREAT WILL BE QUICK TO END EITHER LATE THIS AFTERNOON OR EARLY EVENING AS THE UPPER LOW TRUCKS NORTHEASTWARD. WATCH WILL BE POSSIBLE THIS AFTERNOON ACROSS THE FAR NORTHEAST. SUNDAY WILL BE AN IN BETWEEN DAY BEFORE ANOTHER SYSTEM APPROACHES THE AREA LATER SUNDAY INTO THE OVERNIGHT HOURS. LOOK FOR HIGHER CLOUDS TO ADVECT IN ACROSS THE NORTHWEST AS WELL AS SOUTHEAST AREAS LATER SUNDAY AND SUNDAY NIGHT. ADJUSTED TEMPS BOTH PERIODS ACCORDINGLY. ESPECIALLY OVERNIGHT LOWS WHERE TEMPS WILL BE ARTIFICIALLY HIGH DUE TO CLOUD COVER AND INCREASING WINDS ALOFT. BOTH NAM AND GFS PRETTY MUCH IN AGREEMENT WITH TIMING AND SYSTEM TRACK FOR MONDAY AND TUESDAY. BUMPED UP WINDS ACROSS SOUTHERN AND EASTERN AREAS ON MONDAY. DIDNT REALLY ADJUST THE POP OR WX FIELD ALL THAT MUCH AS INHERITED PACKAGE LOOKED GOOD. CERTAINLY SOME DRY SLOT CONSIDERATIONS ACROSS THE SOUTH WITH LOW LEVEL HUMIDITIES A PROBLEM FOR HIGHER QPF AMOUNTS BOTH DAYS. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 30 69 44 60 / 0 0 5 30 GALLUP.......................... 23 66 38 59 / 0 0 0 30 GRANTS.......................... 25 68 36 63 / 0 0 0 20 GLENWOOD........................ 37 78 45 73 / 0 0 0 5 CHAMA........................... 16 56 33 50 / 20 0 5 30 LOS ALAMOS...................... 24 67 34 63 / 0 0 0 20 RED RIVER....................... 22 52 34 49 / 20 0 0 20 TAOS............................ 23 65 35 62 / 10 0 0 20 SANTA FE........................ 26 68 35 65 / 5 0 0 10 SANTA FE AIRPORT................ 32 70 41 67 / 0 0 0 10 ESPANOLA........................ 32 73 43 70 / 0 0 0 20 ALBUQUERQUE HEIGHTS............. 39 73 50 72 / 5 0 0 10 ALBUQUERQUE VALLEY.............. 40 75 50 73 / 5 0 0 10 ALBUQUERQUE FOOTHILLS........... 36 72 47 70 / 5 0 0 10 ALBUQUERQUE WEST MESA........... 39 74 49 71 / 5 0 0 10 SOCORRO......................... 41 76 51 76 / 0 0 0 10 SANDIA PARK/CEDAR CREST......... 32 68 44 68 / 5 0 0 10 MORIARTY/ESTANCIA............... 34 69 48 69 / 0 0 0 10 CARRIZOZO....................... 38 71 53 73 / 0 0 0 5 RUIDOSO......................... 39 63 50 63 / 0 0 0 5 RATON........................... 30 71 37 70 / 10 0 0 10 LAS VEGAS....................... 33 69 41 66 / 0 0 0 5 ROY............................. 39 72 50 72 / 5 0 0 5 CLAYTON......................... 40 74 47 77 / 20 0 0 5 SANTA ROSA...................... 43 77 52 79 / 5 0 0 5 TUCUMCARI....................... 42 78 49 82 / 10 0 0 5 FORT SUMNER..................... 43 79 49 82 / 5 0 0 5 CLOVIS.......................... 43 78 53 80 / 5 0 0 5 PORTALES........................ 41 79 52 82 / 5 0 0 5 ROSWELL......................... 44 81 53 84 / 5 0 0 5 && .ABQ WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 8 PM MDT THIS EVENING FOR THE FOLLOWING ZONES... NMZ004>007-009>013-015-018>021-026. HIGH WIND WARNING UNTIL 8 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ016-017. && $$ 50 nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 935 AM EDT SUN APR 22 2007 .SYNOPSIS... 12Z SFC ANALYSIS SHOWS 1026 MB HIGH PRESSURE CENTERED OVER UPSTATE SC AND WESTERN NC. TEMPS ACROSS THE AREA WERE IN THE MID 50S TO LOWER 60S AND DEWPOINTS WERE IN THE LOWER/MID 40S. THE 12Z GSO SOUNDING WAS VERY DRY WITH A PWAT OF 0.33 INCHES AND DEWPOINTS OF 25-30F AS LOW AS 925-950 MB. && .SHORT TERM /REST OF TODAY/... FORECAST ON TRACK THIS AFTERNOON WITH CLEAR SKIES AND HIGH TEMPS IN THE LOWER 80S AS H5 RIDGE CONTINUES TO BUILD OVER THE MID-ATLANTIC AND SFC HIGH PRESSURE PASSES OVERHEAD AND TO THE S/SE BY EVENING. GIVEN THE AMOUNT OF DRY AIR IN THE 12Z GSO SOUNDING THIS MORNING AND WHAT HAPPENED YESTERDAY AFTERNOON WITH DEWPOINTS PLUNGING INTO THE MID 20S TO LOWER 30S BETWEEN 15-17Z OR SO...FEEL CONFIDENT IN SHOWING A SIMILAR TREND THIS AFTERNOON OF DEWPOINTS FALLING INTO THE LOWER 30S. THIS WILL YIELD MINIMUM RH VALUES AROUND 20% DURING THE AFTERNOON. LIGHT SOUTHWEST WINDS OF 7-12 MPH AT THE SFC AND ALOFT WILL PREVENT CRITICAL FIRE WEATHER CONDITIONS FROM BEING ATTAINED THIS AFTERNOON...HOWEVER...VERY DRY RH VALUES COMBINED WITH MIXING HEIGHTS OF UP TO 8000 FT WILL LIKELY CREATE ADVERSE CONDITIONS DURING PEAK DIURNAL HEATING/MIXING. -VINCENT && .PREV DISCUSSION... /ISSUED 640 AM EDT SUN APR 22 2007/ SHORT TERM /REST OF TODAY THROUGH MONDAY/... BASED ON TRENDS EVIDENT IN THE NEW 06Z NAM/GFS OF A STOUT AND GUSTY SOUTHWEST BREEZE MONDAY SUSTAINED AROUND 10 TO 20 MPH AND GUSTING TO AT LEAST 30 MPH... HAVE UPDATED GRAPHICAL AND TEXT PRODUCTS TO REFLECT THESE STRONGER WINDS TOMORROW. SEE FIRE WEATHER CONCERNS BELOW. -GIH AVIATION /12Z-12Z/... CONDITIONS WILL BE VFR. GFS MODEL SOUNDINGS SUGGEST SLIGHTLY COOLER TEMPERATURES BETWEEN 800MB AND 500MB CENTRAL AND EAST THIS AFTERNOON...WHICH WITH DIURNAL MIXING COULD RESULT IN A FEW CU IF THE SOUNDINGS NEAR KRDU AND KRWI VERIFY VERY CLOSE TO THE FORECAST. THE GFS SOUNDING APPEARS TO BE A LITTLE HIGH ON ITS SURFACE DEW POINT AND IF DEW POINTS ARE MUCH LOWER THERE WOULD BE COMPLETE BLUE AGAIN TODAY. FEW CU AT MOST WITH SURFACE WINDS 10KT OR LESS... VEERING TO THE WEST EARLY TODAY AND RETURNING TO SOUTH-TO-SOUTHWEST LATE...CONTINUING THIS EVENING. -DJF FIRE WEATHER... BASED ON THESE STRONG/GUSTY WINDS AND LOW RELATIVE HUMIDITY... THE STORM PREDICTION CENTER HAS OUTLOOKED THE REGION FOR NEAR-CRITICAL FIRE WEATHER CONDITIONS ON MONDAY. RH IS FORECAST TO BOTTOM OUT AT 30-35% MONDAY AFTERNOON. A FIRE DANGER STATEMENT OR FIRE WEATHER WATCH MAY BE NEEDED LATER TODAY FOR MONDAY... ESPECIALLY IF RH FORECASTS BEGIN TO TREND LOWER. SEE DISCUSSION BELOW FOR TODAY`S FIRE WEATHER ISSUES. -GIH PREV DISCUSSION... /ISSUED 325 AM EDT SUN APR 22 2007/ SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... TODAY/TONIGHT: CONTINUED QUIET... GENERALLY CLOUD-FREE... DRY AND WARM WITH SURFACE HIGH PRESSURE AND HIGHLY AMPLIFIED MID LEVEL RIDGING OVERHEAD. APART FROM THE VERY WARM TEMPERATURES PEAKING IN THE 80-84 RANGE TODAY... OF NOTE WILL BE THE LOW RELATIVE HUMIDITY VALUES WITH EXPECTATIONS OF DEWPOINTS DROPPING WELL DOWN THROUGH THE 30S THIS AFTERNOON... AND POSSIBLE LOWER. SEE FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS. LOWS TONIGHT GENERALLY 46-51... BUT OUTLYING RURAL AREAS MAY SEE COOLER READINGS. MONDAY THROUGH TUESDAY NIGHT: THE SURFACE HIGH SHIFTS SLOWLY SOUTHEAST AND OFFSHORE STARTING THIS AFTERNOON... INTRODUCING STEADIER SOUTHWEST WINDS AND SLOWLY INCREASING THICKNESSES AND MOISTURE OVER CENTRAL NC. THIS MORNING`S MID LEVEL TROUGH AND SURFACE LOW OVER THE PLAINS WILL DAMPEN AS IT HEADS NORTHEAST THROUGH THE GREAT LAKES AND NEW ENGLAND THROUGH EARLY TUESDAY. THIS TROUGH HELPS TAMP DOWN THE MID LEVEL RIDGE OVER THE GULF OF MEXICO AND SOUTHEAST STATES... A BIT MORE PROFOUND ON THE NAM THAN THE GFS. AN 850 MB THETA-E RIDGE TO OUR WSW NOSES TOWARD WESTERN NC... AND MODELS SHOW A 40-50 KT LOW LEVEL JET ZIPPING ACROSS VA MONDAY NIGHT... HOWEVER THE WESTERLY-SHIFTING 850 MB WINDS SHOULD LIMIT MOISTURE EAST OF THE MOUNTAINS AND MOST OF THE LIFT IS TO OUR NORTH... SO WILL STAY DRY THROUGH MONDAY NIGHT BUT EXPECT INCREASING CLOUDS NW TO SE. HIGHS 80-84 MONDAY... FOLLOWED BY LOWS 53-56. THEN ON TUESDAY... THE FRONT BECOMES W-E ORIENTED TO OUR NORTH WITH MODELS DEVELOPING A SURFACE LOW OVER SOUTH CENTRAL VA LATE IN THE DAY. PRECIPITABLE WATER VALUES REMAIN HIGH ENOUGH... ABOUT 150% OF NORMAL... AND INCREASING INSTABILITY WITH CAPES RISING OVER 500 J/KG FAVORS AT LEAST A LOW CHANCE OF CONVECTION TUESDAY AFTERNOON/EVENING DESPITE A WARM POCKET IN THE MID LEVELS. HIGHS 80-83... WITH LOWS TUESDAY NIGHT 55-60 UNDER PARTLY TO MOSTLY CLOUDY SKIES. -GIH LONG TERM /WEDNESDAY THROUGH SATURDAY/... LITTLE CHANGE NEEDED. HAVE KEPT A SLIGHT CHANCE OF AN AFTERNOON OR EVENING STORM ACROSS THE NORTH WEDNESDAY GIVEN THE SURFACE LOW THAT THE GFS/ECMWF ZIP ACROSS NORTHERN VA LATE IN THE DAY AND THE TAIL END OF ITS WEAK SURFACE TROUGH THAT DRAGS ALONG THE NC/VA BORDER. HOWEVER WITH THE MID LEVEL SHORTWAVE RIDGING AHEAD OF THE SOUTHERN PLAINS TROUGH... ANY ACTIVITY SHOULD BE QUITE ISOLATED. THIS WAVE DAMPENS AS IT HEADS UP THROUGH THE OHIO VALLEY AND INTO THE NORTHEAST THROUGH FRIDAY. THE TRAILING COLD FRONT MOVES INTO THE NC MOUNTAINS LATE THURSDAY AND REALLY LOSES DEFINITION THROUGH FRIDAY... SO MUCH THAT LOW LEVEL THICKNESSES... WHICH REMAIN ABOVE NORMAL THROUGH THIS PERIOD... SHOW NO RESPONSE THROUGH FRIDAY. LARGE SCALE FORCING FOR LIFT WANES CONSIDERABLY... SO QPF MAY BE SORELY LIMITED IN OUR NECK OF THE WOODS... BUT HAVE KEPT CHANCE POPS THURSDAY AFTERNOON THROUGH FRIDAY MORNING. DRY THEREAFTER WITH THE CONSISTENT GFS SHOWING A DRY COLUMN AND STABILIZING MID LEVELS THROUGH SATURDAY. HIGHS IN THE MID 80S WEDNESDAY AND IN THE UPPER 70S TO AROUND 80 THURSDAY-SATURDAY WITH AN INCREASE IN CLOUD COVER. LOWS MOSTLY IN THE MID 50S TO LOWER 60S EACH MORNING. -GIH AVIATION /06Z-06Z/... DURING THE OVERNIGHT HOURS OF FRIDAY...RAPID EVENING COOLING OVER CENTRAL NORTH CAROLINA...COMBINED WITH SLIGHTLY HIGHER DEW POINTS AT THE TIME...RESULTED IN A BRIEF PERIOD OF MVFR-TO-IFR FOG AT KFAY AND KRWI. EARLY THIS MORNING...THE TEMPERATURE/DEW POINT SPREAD IS HIGHER...AND IN A FEW LOCATIONS THERE HAS BEEN JUST ENOUGH MIXING TO RESULT IN A LIGHT...BUT OBSERVED...WIND FROM THE SOUTHWEST. AROUND 06Z...SURFACE TEMPERATURES ACTUALLY ROSE AT KRWI. DEW POINTS ARE HIGHEST TOWARD THE EAST AND HAVE PROVIDED FOR A BRIEF PERIOD OF MVFR...LIGHT FOG AT KRWI...BUT ELSEWHERE ANTICIPATE VFR CONDITIONS. GFS MODEL SOUNDINGS SUGGEST SLIGHTLY COOLER TEMPERATURES BETWEEN 800MB AND 500MB CENTRAL AND EAST THIS AFTERNOON...WHICH WITH DIURNAL MIXING COULD RESULT IN A FEW CU IF THE SOUNDINGS NEAR KRDU AND KRWI VERIFY VERY CLOSE TO THE FORECAST. THE GFS SOUNDING APPEARS TO BE A LITTLE HIGH ON ITS SURFACE DEW POINT AND IF DEW POINTS ARE MUCH LOWER THERE WOULD BE COMPLETE BLUE AGAIN TODAY. FEW CU AT MOST WITH SURFACE WINDS 10KT OR LESS...VEERING TO THE WEST EARLY AND RETURNING TO SOUTH-TO-SOUTHWEST LATE. -DJF FIRE WEATHER... VISIBLE SATELLITE IMAGERY FROM YESTERDAY REVEALED FIRES BURNING IN HARNETT... CUMBERLAND... AND HOKE COUNTIES... AS RELATIVE HUMIDITY VALUES PLUMMETED TO 16-20% DURING THE AFTERNOON... MUCH LOWER THAN MOS GUIDANCE VALUES INDICATED. WHILE A LIGHT SOUTHWEST BREEZE MAY KEEP DEWPOINTS FROM CRASHING QUITE AS MUCH AS THEY DID YESTERDAY WHEN THE WINDS WERE LIGHTER AND VARIABLE... WITH NO CHANGE IN AIR MASS... ANOTHER STEEP DROP IN RELATIVE HUMIDITY VALUES IS EXPECTED TODAY. FORECAST DEWPOINTS WILL BE ABOUT 10 DEGREES BELOW MOS GUIDANCE VALUES... CLOSE TO THE NUMBERS ONE GETS WHEN THE LOWEST 100 MB ON THE MORNING RUC SOUNDING IS MIXED. THE LOWEST HUMIDITY SHOULD BE IN THE NORTHEAST CWA. THERE SHOULD BE A RAPID RECOVERY INTO THE 30-40% RANGE TOWARD SUNSET. WHILE WIND WILL NOT BE A MAJOR FIRE CONCERN WITH W TO SW SURFACE WINDS GENERALLY 5 TO 10 MPH AND FAIRLY LIGHT ALOFT... GIVEN THE FINE FUEL MOISTURE LEVELS THAT ARE DOWN TO ABOUT 3-5%... THESE DRY RH VALUES WILL NOT HELP THIS SITUATION. EXPECT MIXING HEIGHTS TODAY UP TO 8000 FT. -GIH/DJF && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT SHORT TERM...VINCENT nc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`S FIRE WEATHER ISSUES. -GIH && .PREV DISCUSSION... /ISSUED 325 AM EDT SUN APR 22 2007/ SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... TODAY/TONIGHT: CONTINUED QUIET... GENERALLY CLOUD-FREE... DRY AND WARM WITH SURFACE HIGH PRESSURE AND HIGHLY AMPLIFIED MID LEVEL RIDGING OVERHEAD. APART FROM THE VERY WARM TEMPERATURES PEAKING IN THE 80-84 RANGE TODAY... OF NOTE WILL BE THE LOW RELATIVE HUMIDITY VALUES WITH EXPECTATIONS OF DEWPOINTS DROPPING WELL DOWN THROUGH THE 30S THIS AFTERNOON... AND POSSIBLE LOWER. SEE FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS. LOWS TONIGHT GENERALLY 46-51... BUT OUTLYING RURAL AREAS MAY SEE COOLER READINGS. MONDAY THROUGH TUESDAY NIGHT: THE SURFACE HIGH SHIFTS SLOWLY SOUTHEAST AND OFFSHORE STARTING THIS AFTERNOON... INTRODUCING STEADIER SOUTHWEST WINDS AND SLOWLY INCREASING THICKNESSES AND MOISTURE OVER CENTRAL NC. THIS MORNING`S MID LEVEL TROUGH AND SURFACE LOW OVER THE PLAINS WILL DAMPEN AS IT HEADS NORTHEAST THROUGH THE GREAT LAKES AND NEW ENGLAND THROUGH EARLY TUESDAY. THIS TROUGH HELPS TAMP DOWN THE MID LEVEL RIDGE OVER THE GULF OF MEXICO AND SOUTHEAST STATES... A BIT MORE PROFOUND ON THE NAM THAN THE GFS. AN 850 MB THETA-E RIDGE TO OUR WSW NOSES TOWARD WESTERN NC... AND MODELS SHOW A 40-50 KT LOW LEVEL JET ZIPPING ACROSS VA MONDAY NIGHT... HOWEVER THE WESTERLY-SHIFTING 850 MB WINDS SHOULD LIMIT MOISTURE EAST OF THE MOUNTAINS AND MOST OF THE LIFT IS TO OUR NORTH... SO WILL STAY DRY THROUGH MONDAY NIGHT BUT EXPECT INCREASING CLOUDS NW TO SE. HIGHS 80-84 MONDAY... FOLLOWED BY LOWS 53-56. THEN ON TUESDAY... THE FRONT BECOMES W-E ORIENTED TO OUR NORTH WITH MODELS DEVELOPING A SURFACE LOW OVER SOUTH CENTRAL VA LATE IN THE DAY. PRECIPITABLE WATER VALUES REMAIN HIGH ENOUGH... ABOUT 150% OF NORMAL... AND INCREASING INSTABILITY WITH CAPES RISING OVER 500 J/KG FAVORS AT LEAST A LOW CHANCE OF CONVECTION TUESDAY AFTERNOON/EVENING DESPITE A WARM POCKET IN THE MID LEVELS. HIGHS 80-83... WITH LOWS TUESDAY NIGHT 55-60 UNDER PARTLY TO MOSTLY CLOUDY SKIES. -GIH LONG TERM /WEDNESDAY THROUGH SATURDAY/... LITTLE CHANGE NEEDED. HAVE KEPT A SLIGHT CHANCE OF AN AFTERNOON OR EVENING STORM ACROSS THE NORTH WEDNESDAY GIVEN THE SURFACE LOW THAT THE GFS/ECMWF ZIP ACROSS NORTHERN VA LATE IN THE DAY AND THE TAIL END OF ITS WEAK SURFACE TROUGH THAT DRAGS ALONG THE NC/VA BORDER. HOWEVER WITH THE MID LEVEL SHORTWAVE RIDGING AHEAD OF THE SOUTHERN PLAINS TROUGH... ANY ACTIVITY SHOULD BE QUITE ISOLATED. THIS WAVE DAMPENS AS IT HEADS UP THROUGH THE OHIO VALLEY AND INTO THE NORTHEAST THROUGH FRIDAY. THE TRAILING COLD FRONT MOVES INTO THE NC MOUNTAINS LATE THURSDAY AND REALLY LOSES DEFINITION THROUGH FRIDAY... SO MUCH THAT LOW LEVEL THICKNESSES... WHICH REMAIN ABOVE NORMAL THROUGH THIS PERIOD... SHOW NO RESPONSE THROUGH FRIDAY. LARGE SCALE FORCING FOR LIFT WANES CONSIDERABLY... SO QPF MAY BE SORELY LIMITED IN OUR NECK OF THE WOODS... BUT HAVE KEPT CHANCE POPS THURSDAY AFTERNOON THROUGH FRIDAY MORNING. DRY THEREAFTER WITH THE CONSISTENT GFS SHOWING A DRY COLUMN AND STABILIZING MID LEVELS THROUGH SATURDAY. HIGHS IN THE MID 80S WEDNESDAY AND IN THE UPPER 70S TO AROUND 80 THURSDAY-SATURDAY WITH AN INCREASE IN CLOUD COVER. LOWS MOSTLY IN THE MID 50S TO LOWER 60S EACH MORNING. -GIH AVIATION /06Z-06Z/... DURING THE OVERNIGHT HOURS OF FRIDAY...RAPID EVENING COOLING OVER CENTRAL NORTH CAROLINA...COMBINED WITH SLIGHTLY HIGHER DEW POINTS AT THE TIME...RESULTED IN A BRIEF PERIOD OF MVFR-TO-IFR FOG AT KFAY AND KRWI. EARLY THIS MORNING...THE TEMPERATURE/DEW POINT SPREAD IS HIGHER...AND IN A FEW LOCATIONS THERE HAS BEEN JUST ENOUGH MIXING TO RESULT IN A LIGHT...BUT OBSERVED...WIND FROM THE SOUTHWEST. AROUND 06Z...SURFACE TEMPERATURES ACTUALLY ROSE AT KRWI. DEW POINTS ARE HIGHEST TOWARD THE EAST AND HAVE PROVIDED FOR A BRIEF PERIOD OF MVFR...LIGHT FOG AT KRWI...BUT ELSEWHERE ANTICIPATE VFR CONDITIONS. GFS MODEL SOUNDINGS SUGGEST SLIGHTLY COOLER TEMPERATURES BETWEEN 800MB AND 500MB CENTRAL AND EAST THIS AFTERNOON...WHICH WITH DIURNAL MIXING COULD RESULT IN A FEW CU IF THE SOUNDINGS NEAR KRDU AND KRWI VERIFY VERY CLOSE TO THE FORECAST. THE GFS SOUNDING APPEARS TO BE A LITTLE HIGH ON ITS SURFACE DEW POINT AND IF DEW POINTS ARE MUCH LOWER THERE WOULD BE COMPLETE BLUE AGAIN TODAY. FEW CU AT MOST WITH SURFACE WINDS 10KT OR LESS...VEERING TO THE WEST EARLY AND RETURNING TO SOUTH-TO-SOUTHWEST LATE. -DJF FIRE WEATHER... VISIBLE SATELLITE IMAGERY FROM YESTERDAY REVEALED FIRES BURNING IN HARNETT... CUMBERLAND... AND HOKE COUNTIES... AS RELATIVE HUMIDITY VALUES PLUMMETED TO 16-20% DURING THE AFTERNOON... MUCH LOWER THAN MOS GUIDANCE VALUES INDICATED. WHILE A LIGHT SOUTHWEST BREEZE MAY KEEP DEWPOINTS FROM CRASHING QUITE AS MUCH AS THEY DID YESTERDAY WHEN THE WINDS WERE LIGHTER AND VARIABLE... WITH NO CHANGE IN AIR MASS... ANOTHER STEEP DROP IN RELATIVE HUMIDITY VALUES IS EXPECTED TODAY. FORECAST DEWPOINTS WILL BE ABOUT 10 DEGREES BELOW MOS GUIDANCE VALUES... CLOSE TO THE NUMBERS ONE GETS WHEN THE LOWEST 100 MB ON THE MORNING RUC SOUNDING IS MIXED. THE LOWEST HUMIDITY SHOULD BE IN THE NORTHEAST CWA. THERE SHOULD BE A RAPID RECOVERY INTO THE 30-40% RANGE TOWARD SUNSET. WHILE WIND WILL NOT BE A MAJOR FIRE CONCERN WITH W TO SW SURFACE WINDS GENERALLY 5 TO 10 MPH AND FAIRLY LIGHT ALOFT... GIVEN THE FINE FUEL MOISTURE LEVELS THAT ARE DOWN TO ABOUT 3-5%... THESE DRY RH VALUES WILL NOT HELP THIS SITUATION. EXPECT MIXING HEIGHTS TODAY UP TO 8000 FT. -GIH/DJF && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HARTFIELD AVIATION...DJF FIRE WEATHER...HARTFIELD nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 325 AM EDT SUN APR 22 2007 .SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... TODAY/TONIGHT: CONTINUED QUIET... GENERALLY CLOUD-FREE... DRY AND WARM WITH SURFACE HIGH PRESSURE AND HIGHLY AMPLIFIED MID LEVEL RIDGING OVERHEAD. APART FROM THE VERY WARM TEMPERATURES PEAKING IN THE 80-84 RANGE TODAY... OF NOTE WILL BE THE LOW RELATIVE HUMIDITY VALUES WITH EXPECTATIONS OF DEWPOINTS DROPPING WELL DOWN THROUGH THE 30S THIS AFTERNOON... AND POSSIBLE LOWER. SEE FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS. LOWS TONIGHT GENERALLY 46-51... BUT OUTLYING RURAL AREAS MAY SEE COOLER READINGS. MONDAY THROUGH TUESDAY NIGHT: THE SURFACE HIGH SHIFTS SLOWLY SOUTHEAST AND OFFSHORE STARTING THIS AFTERNOON... INTRODUCING STEADIER SOUTHWEST WINDS AND SLOWLY INCREASING THICKNESSES AND MOISTURE OVER CENTRAL NC. THIS MORNING`S MID LEVEL TROUGH AND SURFACE LOW OVER THE PLAINS WILL DAMPEN AS IT HEADS NORTHEAST THROUGH THE GREAT LAKES AND NEW ENGLAND THROUGH EARLY TUESDAY. THIS TROUGH HELPS TAMP DOWN THE MID LEVEL RIDGE OVER THE GULF OF MEXICO AND SOUTHEAST STATES... A BIT MORE PROFOUND ON THE NAM THAN THE GFS. AN 850 MB THETA-E RIDGE TO OUR WSW NOSES TOWARD WESTERN NC... AND MODELS SHOW A 40-50 KT LOW LEVEL JET ZIPPING ACROSS VA MONDAY NIGHT... HOWEVER THE WESTERLY-SHIFTING 850 MB WINDS SHOULD LIMIT MOISTURE EAST OF THE MOUNTAINS AND MOST OF THE LIFT IS TO OUR NORTH... SO WILL STAY DRY THROUGH MONDAY NIGHT BUT EXPECT INCREASING CLOUDS NW TO SE. HIGHS 80-84 MONDAY... FOLLOWED BY LOWS 53-56. THEN ON TUESDAY... THE FRONT BECOMES W-E ORIENTED TO OUR NORTH WITH MODELS DEVELOPING A SURFACE LOW OVER SOUTH CENTRAL VA LATE IN THE DAY. PRECIPITABLE WATER VALUES REMAIN HIGH ENOUGH... ABOUT 150% OF NORMAL... AND INCREASING INSTABILITY WITH CAPES RISING OVER 500 J/KG FAVORS AT LEAST A LOW CHANCE OF CONVECTION TUESDAY AFTERNOON/EVENING DESPITE A WARM POCKET IN THE MID LEVELS. HIGHS 80-83... WITH LOWS TUESDAY NIGHT 55-60 UNDER PARTLY TO MOSTLY CLOUDY SKIES. -GIH && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... LITTLE CHANGE NEEDED. HAVE KEPT A SLIGHT CHANCE OF AN AFTERNOON OR EVENING STORM ACROSS THE NORTH WEDNESDAY GIVEN THE SURFACE LOW THAT THE GFS/ECMWF ZIP ACROSS NORTHERN VA LATE IN THE DAY AND THE TAIL END OF ITS WEAK SURFACE TROUGH THAT DRAGS ALONG THE NC/VA BORDER. HOWEVER WITH THE MID LEVEL SHORTWAVE RIDGING AHEAD OF THE SOUTHERN PLAINS TROUGH... ANY ACTIVITY SHOULD BE QUITE ISOLATED. THIS WAVE DAMPENS AS IT HEADS UP THROUGH THE OHIO VALLEY AND INTO THE NORTHEAST THROUGH FRIDAY. THE TRAILING COLD FRONT MOVES INTO THE NC MOUNTAINS LATE THURSDAY AND REALLY LOSES DEFINITION THROUGH FRIDAY... SO MUCH THAT LOW LEVEL THICKNESS... WHICH REMAIN ABOVE NORMAL THROUGH THIS PERIOD... SHOW NO RESPONSE THROUGH FRIDAY. LARGE SCALE FORCING FOR LIFT WANES CONSIDERABLY... SO QPF MAY BE SORELY LIMITED IN OUR NECK OF THE WOODS... BUT HAVE KEPT CHANCE POPS THURSDAY AFTERNOON THROUGH FRIDAY MORNING. DRY THEREAFTER WITH THE CONSISTENT GFS SHOWING A DRY COLUMN AND STABILIZING MID LEVELS THROUGH SATURDAY. HIGHS IN THE MID 80S WEDNESDAY AND IN THE UPPER 70S TO AROUND 80 THURSDAY-SATURDAY WITH AN INCREASE IN CLOUD COVER. LOWS MOSTLY IN THE MID 50S TO LOWER 60S EACH MORNING. -GIH && .AVIATION /06Z-06Z/... DURING THE OVERNIGHT HOURS OF FRIDAY...RAPID EVENING COOLING OVER CENTRAL NORTH CAROLINA...COMBINED WITH SLIGHTLY HIGHER DEW POINTS AT THE TIME...RESULTED IN A BRIEF PERIOD OF MVFR-TO-IFR FOG AT KFAY AND KRWI. EARLY THIS MORNING...THE TEMPERATURE/DEW POINT SPREAD IS HIGHER...AND IN A FEW LOCATIONS THERE HAS BEEN JUST ENOUGH MIXING TO RESULT IN A LIGHT...BUT OBSERVED...WIND FROM THE SOUTHWEST. AROUND 06Z...SURFACE TEMPERATURES ACTUALLY ROSE AT KRWI. DEW POINTS ARE HIGHEST TOWARD THE EAST AND HAVE PROVIDED FOR A BRIEF PERIOD OF MVFR...LIGHT FOG AT KRWI...BUT ELSEWHERE ANTICIPATE VFR CONDITIONS. GFS MODEL SOUNDINGS SUGGEST SLIGHTLY COOLER TEMPERATURES BETWEEN 800MB AND 500MB CENTRAL AND EAST THIS AFTERNOON...WHICH WITH DIURNAL MIXING COULD RESULT IN A FEW CU IF THE SOUNDINGS NEAR KRDU AND KRWI VERIFY VERY CLOSE TO THE FORECAST. THE GFS SOUNDING APPEARS TO BE A LITTLE HIGH ON ITS SURFACE DEW POINT AND IF DEW POINTS ARE MUCH LOWER THERE WOULD BE COMPLETE BLUE AGAIN TODAY. FEW CU AT MOST WITH SURFACE WINDS 10KT OR LESS...VEERING TO THE WEST EARLY AND RETURNING TO SOUTH-TO-SOUTHWEST LATE. && .FIRE WEATHER... VISIBLE SATELLITE IMAGERY FROM YESTERDAY REVEALED FIRES BURNING IN HARNETT... CUMBERLAND... AND HOKE COUNTIES... AS RELATIVE HUMIDITY VALUES PLUMMETED TO 16-20% DURING THE AFTERNOON... MUCH LOWER THAN MOS GUIDANCE VALUES INDICATED. WHILE A LIGHT SOUTHWEST BREEZE MAY KEEP DEWPOINTS FROM CRASHING QUITE AS MUCH AS THEY DID YESTERDAY WHEN THE WINDS WERE LIGHTER AND VARIABLE... WITH NO CHANGE IN AIR MASS... ANOTHER STEEP DROP IN RELATIVE HUMIDITY VALUES IS EXPECTED TODAY. FORECAST DEWPOINTS WILL BE ABOUT 10 DEGREES BELOW MOS GUIDANCE VALUES... CLOSE TO THE NUMBERS ONE GETS WHEN THE LOWEST 100 MB ON THE MORNING RUC SOUNDING IS MIXED. THE LOWEST HUMIDITY SHOULD BE IN THE NORTHEAST CWA. THERE SHOULD BE A RAPID RECOVERY INTO THE 30-40% RANGE TOWARD SUNSET. WHILE WIND WILL NOT BE A MAJOR FIRE CONCERN WITH W TO SW SURFACE WINDS GENERALLY 5 TO 10 MPH AND FAIRLY LIGHT ALOFT... GIVEN THE FINE FUEL MOISTURE LEVELS THAT ARE DOWN TO ABOUT 3-5%... THESE DRY RH VALUES WILL NOT HELP THIS SITUATION. EXPECT MIXING HEIGHTS TODAY UP TO 8000 FT. -GIH/DJF && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...DJF FIRE WEATHER... nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 253 PM CDT SUN APR 22 2007 .DISCUSSION... 18Z WATER VAPOR SHOWS AN UPPER LEVEL LOW OVER ERN NE. SFC BOUNDARY ASSOCIATED WITH THIS SYSTEM EXTENDS FROM OVER LAKE SUPERIOR...THROUGH SE MINNESOTA...AND INTO ERN NE... WITH PRECIPITATION EXTENDING ALONG THIS BOUNDARY ON MN SIDE OF CWA. && .SHORT TERM (SUN NIGHT-WED) FORECAST FOCUS TONIGHT ON PRECIPITATION ENDING IN ERN HALF OF CWA. 12Z NAM SHOWING BACK EDGE OF PRECIPITATION BAND MOVING OUT OF SOUTHEASTERN CORNER OF CWA BETWEEN 00Z AND 03Z...WHILE RUC80 HOLDING ON UNTIL THE 03Z TO 06Z TIME FRAME. TENDING TOWARDS RUC SOLUTION AND KEEPING PRECIP IN UNTIL 06Z...WITH GENERALLY AROUND ONE TENTH OF AN INCH QPF...HOWEVER EXTREME SE CORNER COULD SEE AROUND ONE THIRD OF AN INCH THROUGH MIDNIGHT. NEXT FOCUS ON A WEAK WAVE CLIPPING THE NORTHWEST CORNER OF THE CWA ON TUESDAY. MODELS IN FAIRLY DECENT AGREEMENT WITH WEAK...MID LEVEL DISTURBANCE PASSING THROUGH SOUTHWESTERN MANITOBA TUE MORNING...AND WEAKENING AS IT ENTERS THE NW CORNER OF THE CWA ON TUE AFTERNOON. MODELS DO BRING WEAK QPFS INTO NORTHEASTERN NORTH DAKOTA...HOWEVER A SFC RIDGE IS PRGOGGED TO EXTEND DOWN FROM NRN MANITOBA ...AND NORTHEAST FLOW SHOULD KEEP THE LOWER LAYERS DRY. BUFKIT SOUNDINGS SHOWING A DRY LAYER BELOW 6000 FEET. EXPECT MID LEVEL CLOUDS WITH POSSIBLE VIRGA SHOWERS AT MOST AT THIS TIME. && .LONG TERM (THU-SUN)...SPLIT FLOW PATTERN TO TRANSITION TOWARDS WEAK ZONAL. MODELS AGREE PRETTY WELL ON A WEAK SYSTEM PASSING THROUGH ON THU WITH LIGHT HIT AND MISS PRECIP...OTHERWISE DRY AT LEAST TIL LATE SAT. LATE SAT INTO SUNDAY IS A BIGGER QUESTION AS 12Z GFS AND ECMWF DISAGREE WIDELY OVER AMPLIFYING ANOTHER 500 MB TROUGH...AGAIN INTO MB AND LOW POPS ARE APPLICABLE FARTHER SOUTH. NEAR OR SLIGHTLY ABOVE SEASONAL TEMPERATURES TO PERSIST THIS WEEK AS FLOW IS NOT EXPECTED TO AMPLIFY. && .AVIATION... VFR CONDITIONS EXPECTED THROUGH MON. HIGH SOIL MOISTURE AT FAR/BJI WILL BE OFF SET BY DRY ADVECTION AND A CONTINUING VERY LIGHT NORTH BREEZE. SO NO LOW CLOUDS/FOG EXPECTED TONIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SPEICHER/GV nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 230 AM CDT SUN APR 22 2007 FORECAST CHALLENGE CONCERNS ADDITIONAL RAINFALL/FLOOD HEADLINES AND TEMPERATURES. MODELS IN REASONABLE AGREEMENT THROUGH PERIOD SO WILL USE BLEND FOR FORECAST. CURRENT WEAKENING CONVECTIVE COMPLEX CONTINUES TO AFFECT SE HALF OF FA SOUTHWARD INTO EASTERN SD. RUC AND GFS WEAKEN AND SHIFT LOW LEVEL JET FLOW MORE WESTERLY AND WARM ADVECTION ALSO SHIFTS EAST SO DO NOT EXPECT ANY WEST/NORTHWARD EXPANSION OF CURRENT PCPN BAND. WILL MONITOR FOR T TRENDS AND LIKELY MAINTAIN HIGH POPS OVER FAR EAST DURING AM. WITH THREE HOUR FLASH FLOOD GUIDANCE UNDER CONVECTION AT > 2.5 INCHES...CONVECTION WEAKENING UPSTREAM AND ABOVE TRENDS FEEL POTENTIAL FOR ADDITIONAL HEAVY RAIN PRODUCING FLASH FLOODING WILL DIMINISH ENOUGH TO CANCEL ONGOING WATCH. FOR REMAINDER OF FA COLUMN DRIES TODAY REFLECTED BY CLEARING OVER CENTRAL WESTERN ND. THERE IS AN AREA OF VFR CIGS OVER SASK HOWEVER TIMING WOULD NOT BRING IT IN UNTIL LATE AFTERNOON. MODEST COLD ADVECTION WILL OFFSET SOLAR SOMEWHAT BUT WILL TREND TEMPERATURES TOWARDS WARMER NAM/NGM NUMERICAL GUIDANCE AS GFS SHOWING MORE CLOUD COVER THAN EXPECTED. FARTHER EAST MORE CLOUD COVER EXPECTED SO COOLER GUIDANCE ACCEPTED. SHORT WAVE RIDGE SHIFTS EAST MONDAY AS REGION COMES UNDER INCREASINGLY SPLIT MID LEVEL FLOW. COLD ADVECTION SHUTS DOWN MONDAY HOWEVER WITH COOLER COLUMN AND INTEGRATED RH FIELDS INDICATING SOME POTENTIAL FOR CLOUDS WILL STICK PRETTY CLOSE TO NUMERICAL GUIDANCE. SURFACE LOW PRESSURE ORGANIZED OVER CENTRAL PLAINS AS SOUTHERN STREAM UPPER LOW CLOSES OFF. WILL MAINTAIN LOW POPS OVER FAR SOUTH CLOSER TO DEEPER MOISTURE SOURCE AND WEAK NORTHERN STREAM MID LEVEL TROUGH PASSAGE. NEXT WAVE OF INTEREST LATE IN WORK WEEK AND WILL MAINTAIN POP MENTION FOR THUR NIGHT/FRIDAY. UNTIL THEN WARMING COLUMN SHOULD BRING TEMPERATURES AT OR ABOVE AVERAGE. && AVIATION...MVFR/ISOLD IFR CIGS WITHIN CONVECTION THIS MORNING FROM FAR SE ND INTO WESTERN MN SHOULD GRADUALLY IMPROVE AS PCPN BAND SHIFTS EAST. REMAINDER OF FA SHOULD BE VFR TODAY WITH SOME ISOLD MORNING BR ON BACK EDGE OF CURRENT PCPN SHIELD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ VOELKER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 1007 AM CDT SAT APR 21 2007 .UPDATE...SHOWERS/THUNDERSTORMS HAVE DECREASED SIGNIFICANTLY ACROSS THE AREA. EVEN THE AREA OF STORMS ON CENTRAL ND/SD BORDER WHICH SHOWS AN MCV IS QUICKLY SHRINKING IN SIZE AND WEAKENING MORE THAN ONE WOULD EXPECT. HAVE DECREASED PROBABILITY OF STORMS TO CHANCE CATEGORY THROUGHOUT REGION UNTIL NOON AND MOST OF EAST PORTION TIL 3PM. TWO SHORTWAVES OF CONCERN: ONE CURRENTLY AT SOUTHWEST CORNER OF ND WHICH IS KEEPING THE REMAINING SHOWERS GOING AHEAD OF IT...AND ANOTHER NEAR CO/NE/KS STATE JUNCTION. THE FIRST WILL TARGET NORTHEAST ND AND THE LATTER FARTHER SOUTH AND EAST (INTO RED RIVER VALLEY). AN EARLY EXTRAPOLATIVE APPROACH PLACES THE SHORTWAVES INTO THE CWA MUCH LATER THAN RUC INDICATES BUT IS MORE IN LINE WITH CURRENT PROGRESSION OF THE SHOWERS THEMSELVES. BUT AM NOT SURE OF THE TIMING OF THE LOW LEVEL THERMAL FIELD TO DESTABILIZE ENOUGH TO INITIATE STORMS ANYWAY. OTHERWISE NO CHANGES TO GRIDS OR ZONES AND WILL BE KEEPING WATCH FOR SIGNATURES IN SATELLITE AND OBS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FLASH FLOOD WATCH FROM 6 PM CDT THIS EVENING THROUGH SUNDAY MORNING FOR NDZ039-049-052-053. MN...FLASH FLOOD WATCH FROM 6 PM CDT THIS EVENING THROUGH SUNDAY MORNING FOR MNZ003-029. && $$ GV nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 415 PM PDT SUN APR 22 2007 .SYNOPSIS...HIGH PRESSURE WILL BUILD INTO THE PACIFIC NORTHWEST ON MONDAY BRINGING AN END TO THE COOL AND SHOWERY WEATHER. THE QUIET WEATHER WILL BE SHORT LIVED AS A COLD FRONT MOVES INTO THE REGION ON TUESDAY BRINGING ANOTHER CHANCE FOR RAIN SHOWERS. && .DISCUSSION... TONIGHT AND TOMORROW...A MESOSCALE LOW LEVEL CIRCULATION IS APPARENT IN THE VISIBLE SATELLITE IMAGERY OVER EASTERN WASHINGTON. COMPARING 21Z VAD WIND PROFILER DATA IN THE 850-700MB LAYER FROM KOTX AND KPDT ALSO SHOWS THIS SMALL SCALE FEATURE THAT HAS HELPED PRODUCE THE RAIN SHOWERS OVER THE EASTERN THIRD OF WASHINGTON TODAY. THIS SUBTLE FEATURE IS NOT STRONG DYNAMICALLY...BUT WITH A VERY MOIST ATMOSPHERE AND LAPSE RATES NEAR MOIST ADIABATIC...LITTLE LIFT IS NEEDED TO PRODUCE PRECIPITATION. THE RUC AND GFS SUGGEST THAT THIS SHALLOW FEATURE EXISTS...BUT DOESN`T EXACTLY HAVE THE SMALL SCALE RESOLUTION PEGGED. BOTH MODELS GRADUALLY MINOR THIS CIRCULATION OUT BETWEEN 00Z AND 06Z...SO A GRADUAL DECREASE IN SHOWERS CAN BE EXPECTED THIS EVENING...AND PERHAPS A SHIFT OF THE PRECIPITATION AXIS SOUTHWARD AS THE CIRCULATION IS ABSORBED BE THE LARGER UPPER LOW DIGGING INTO THE GREAT BASIN. THE MOISTURE LEFT BEHIND WILL NOT BE SCOURED OUT VERY EFFICIENTLY SINCE THE LOW LEVEL WIND FIELD WILL BE QUITE LIGHT TONIGHT. AS HIGH LEVEL MOISTURE MOVES EAST WITH THE BIGGER UPPER TROUGH...REDEVELOPMENT OF BROKEN STRATUS IS PROBABLE IN THE SPOKANE...PULLMAN...AND LEWISTON AREAS. LINGERING LOW CLOUDS WILL HAVE THE POTENTIAL TO HINDER OUR WARM UP OVER THE PANHANDLE AND FAR EASTERN WASHINGTON. LOW TO MID 60S ARE WHAT WE EXPECT FOR THE SPOKANE AND PULLMAN AREAS TOMORROW...BUT HIGHS COULD BE A BIT WARMER OR A BIT COOLER DEPENDING ON THE NATURE OF THE STRATUS TOMORROW. TUESDAY...THE NAM AND GFS HAVE BEEN FAIRLY CONSISTENT FORECASTING THE TIMING OF THE ARRIVAL OF THE UPPER LOW THAT IS MOVING OUT OF THE GULF OF ALASKA. PRECIPITABLE WATER VALUES ARE CURRENTLY IMPRESSIVE WITH VALUES EXCEEDING 1.25 INCHES...BUT THE COLD FRONT ASSOCIATED WITH THE APPROACHING TROUGH IS FORECAST TO UNDERGO SIGNIFICANT STRETCHING. BY THE TIME THE FRONT REACHES CENTRAL AND EASTERN WASHINGTON...THE LOWLANDS MAY BE HARD PRESSED TO GET MUCH MEASURABLE PRECIPITATION WITH THIS SYSTEM. SLIGHT CHANCES ALONG THE EAST SLOPES AND INTO THE COLUMBIA BASIN...WITH LOW CHANCES (30-40 PERCENT) FOR THE SPOKANE...PULLMAN...AND LEWISTON AREAS TUESDAY EVENING. /GKOCH WEDNESDAY THROUGH SUNDAY...MODELS TODAY ARE ONCE AGAIN IN RELATIVELY GOOD AGREEMENT...BUT AGAIN HAVING INITIALIZATION PROBLEMS OVER THE GULF OF ALASKA THAT MAY HAVE A BEARING ON THE EVENTUAL FORECAST EVOLUTION THROUGH THE NEXT WEEK. BOTH THE 12Z GFS AND ECMWF INITIALIZED THE SPRAWLING 500 MB LOW THERE MUCH MORE ACCURATELY THAN THE BULK OF THE GEFS MEMBERS AND THE GEFS MEAN...SO FORECAST WILL TREND HEAVILY TOWARD THE OPERATIONAL 12Z GFS AND ECMWF. HOWEVER...THE GENERAL PATTERN SUGGESTED THE LAST SEVERAL DAYS BY GUIDANCE SHOULD HOLD TRUE...THOUGH A FEW TIMING DIFFERENCES COME ABOUT FROM PREVIOUS RUNS...ESPECIALLY WITH THE GFS AND ECMWF WHICH TEND TO BE THE BETTER PERFORMING MEDIUM RANGE MODELS. THE BASIC PATTERN SUGGESTS THAT A BROAD UPPER TROUGH SHOULD BE NEARLY OVERHEAD BY WEDNESDAY. WITH 500 MB TEMPERATURES DROPPING TO AROUND -26C AND THETA-E LAPSE RATES BELOW 700 MB AT OR BELOW ZERO...WESTERLY FLOW OF AROUND 10 TO 15KTS INDICATED BY GFS AND NAM SHOULD HAVE A FAIRLY EAST TIME INTERACTING WITH TOPOGRAPHY TO CAUSE UPSLOPE OROGRAPHIC SHOWERS THROUGH THE DAY WEDNESDAY. GFS AND NAM SEEM TO PICK UP ON THIS VERY WELL IN THEIR QPF FIELDS WITH PRECIPITATION ALONG THE CASCADE RIDGES AND OVER THE NORTHEAST MOUNTAINS AND MOUNTAINS OF THE IDAHO PANHANDLE. HAVE ALSO ADDED SLIGHT CHANCE POPS ALONG THE WEST PLAINS AND PALOUSE GIVEN THE MORE GENTLE UPSLOPE FROM LOWER COLUMBIA BASIN WITH GENERAL FLOW WHICH MAY BE ENOUGH TO ALLOW A FEW SHOWERS TO POP WITH THE LOW LEVEL INSTABILITY NOTED ON THE MODELS. CONDITIONS QUICKLY QUIET DOWN WEDNESDAY NIGHT AS A RATHER SUBDUED RIDGE BEGINS TO BUILD INTO OUR AREA. TEMPERATURES LOOK TO START TO REBOUND SOME...BUT THE WINDOW WITH DECENT WARM ADVECTION IS NOT VERY SIGNIFICANT WITH THE 12Z RUNS TODAY. BY FRIDAY MORNING...THE NEXT SYSTEM LOOKS TO BE PUSHING MOISTURE TOWARD THE CASCADES WITH GOOD Q-CONVERGENCE BELOW 500 MB CROSSING THE NORTHERN 3/4THS OF THE CWA AND GFS INDICATING PRETTY GOOD ISENTROPIC OMEGAS IN THE 295 TO 305K LAYER WITH CONDENSATION PRESSURE DEFICITS FALLING DRASTICALLY AND QUICKLY BELOW 10 MB ON STRONG SOUTHWESTERLY MOISTURE TRANSPORT AT 300K. MODELS FAIL TO HAVE WARM FRONT TRAVERSE AREA ENOUGH WITH THE 12Z RUN TODAY TO GET US FULLY INTO THE WARM SECTOR...AND AS A RESULT BELIEVE THUNDER CHANCES ARE BASICALLY NIL WITH THIS SYSTEM...IN FACT THE FORECAST WILL BASICALLY JUST MENTION STRATIFORM PRECIPITATION ON MAINLY ISENTROPIC ASCENT. WITH A BRIEF INTERLUDE OF SOME COLDER MID-LEVEL AIR SKIRTING JUST NORTH OF THE AREA FRIDAY NIGHT...AND UPSLOPE FLOW PERSISTING BEHIND THE SYSTEM FROM FRIDAY...HAVE ADDED THE CHANCE OF SHOWERY POPS THROUGH FRIDAY NIGHT AS WELL GIVEN STRONG LAPSE RATES AND WIND FLOW. BY LATE SATURDAY AFTERNOON INTO THE BEGINNING OF NEXT WEEK...MODELS OTHER THAN THE DGEX REALLY START TO CRANK HEIGHTS UP OVER THE CWA. THE DGEX SOLUTION DOES INDICATE RIDGING BUILDING IN AS WELL...BUT IN A MUCH MORE SUBDUED FASHION THAN THE GFS AND ECMWF. UNFORTUNATELY THE OPERATIONAL CANADIAN GLOBAL ONLY GOES OUT 144 HRS...BUT CANADIAN GEM ENSEMBLES DO HINT AT A FAIR AMOUNT OF RIDGING BUILDING ALONG THE WEST COAST. HOWEVER...THE CANADIAN SEF ENSEMBLES ARE ALL OVER THE PLACE WITH THEIR SOLUTIONS. FOR THE MOMENT DUE TO CONTINUITY WITH PREVIOUS RUNS OF THE GFS AND ECMWF...THE WARMER SOLUTIONS SEEM MORE PLAUSIBLE. THE MODELS HAVE SLOWED DOWN ABOUT ONE DAY FROM THE 12Z RUNS YESTERDAY...BUT IT SEEMS BY SUNDAY AND DEFINITELY MONDAY NEXT WEEK...WE SHOULD BE IN FOR A STRONG WARMING TREND. /FRIES && .AVIATION... DOWNSLOPE FLOW OFF THE CASCADES IS QUICKLY ERODING THE WESTERN EDGE OF BOTH THE LOW CLOUD FIELD AND PRECIPITATION FIELD. WITH CLEARING COMING IN A BIT EARLIER THAN EXPECTED DUE TO THIS EFFECT...EFFICIENT RADIATION WILL PROBABLY CAUSE INVERSIONS QUICKLY OVERNIGHT AND WITH RAINFALL TODAY...LOW STRATUS AND VALLEY FOG SEEM TO BE A BIT MORE LIKELY UNDER THE INVERSION THAN EARLIER THOUGHT. HAVE THEREFORE CONTINUED WITH THEM IN THE TAFS. HOWEVER...SKIES SCATTER OUT QUICKLY TOMORROW AND VFR CONDITIONS ARE EXPECTED AFTER 18Z EVERYWHERE. /FRIES && .PRELIMINARY POINT TEMPS/POPS... SPOKANE 40 63 42 65 41 55 / 30 10 0 20 40 20 COEUR D`ALENE 40 63 42 65 41 56 / 20 10 10 20 50 20 PULLMAN 38 60 43 64 41 55 / 40 10 10 20 50 20 LEWISTON 46 65 44 70 47 59 / 40 10 10 10 40 10 COLVILLE 38 67 42 65 37 54 / 20 10 0 40 30 20 SANDPOINT 39 65 40 64 43 54 / 20 20 10 20 50 20 KELLOGG 39 61 40 63 41 54 / 30 20 10 20 50 30 MOSES LAKE 42 70 44 67 42 62 / 20 0 10 20 10 10 WENATCHEE 45 70 46 66 44 61 / 10 0 10 20 10 10 OMAK 39 70 42 65 37 60 / 10 0 10 30 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...NONE. WA...NONE. && $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 410 AM MDT MON APR 23 2007 .SHORT TERM (TODAY THROUGH TUESDAY NIGHT)... TROUGH OVER THE WESTERN U.S. IS A BIT COMPLICATED AS SATELLITE AND RUC SHOW MULTIPLE CIRCULATION CENTERS AND VORT MAXES ROTATING AROUND THE MAIN LOW IN SOUTHERN NV. ONE VORT MAX WILL MOVE INTO NW CO AND NE UTAH EARLY THIS MORNING...WITH A SHORT DRIER SLOT OVER CENTRAL AND SW CO AND SE UTAH. THEN THE NEXT VORT MAX WILL MOVE FROM NW AZ/SW UT INTO THE FORECAST AREA THIS AFTERNOON. THE MAIN LOW IS PROJECTED TO MOVE OVER THE FOUR CORNERS AND SOUTHERN CO TONIGHT. CONTEMPLATED A SNOW ADVISORY FOR THE SAN JUAN MT ALONG WITH WFO PUB...BUT WE DECIDED AGAINST IT AT THIS TIME. TEMPS ARE RELATIVELY WARM TONIGHT...-1 TO -4 AT THE COOLEST AT 700 MB. ALSO AM NOT SURE ENOUGH ABOUT THE MOISTURE AVAILABLE NORTH OF THE LOW CENTER. DAY SHIFT WILL BE BETTER ABLE TO ASSESS WHERE THE BEST CONDITIONS WILL BE AFTER SEEING WHERE IT ALL MOVES THIS MORNING. CONDITIONS SHOULD BEGIN IMPROVING TUE AND TUE NIGHT AS LOW MOVES EAST OF THE AREA...THOUGH MAY HAVE AN EXTENDED PERIOD OF WRAP AROUND PRECIPITATION OVER THE NORTHWEST AND PORTIONS OF THE CENTRAL MOUNTAINS. .LONG TERM (WEDNESDAY THROUGH SUNDAY)... THIS PERSISTENT PROGRESSIVE PATTERN IS SHOWING SIGNS OF BREAKING DOWN IN THESE PERIODS...FOR A DRYING AND WARMING TREND...ESPECIALLY BY NEXT WEEKEND. SYNOPTIC TIMING IS SIMILAR TO PREVIOUS RUNS. THE NEXT WAVE SPLITS WITH THE NORTHERN BRANCH BRUSHING THE NORTHERN EDGE OF THE FORECAST AREA ON THU. SOME ENERGY IN THE SOUTHERN PORTION GETS TRAPPED SOMEWHERE IN THE BAJA REGION...THEN WEAKENS STILL FURTHER AS IT EJECTS EASTWARD LATE IN THE PERIOD. MODELS HAVE BEEN TRENDING WEAKER WITH THE NORTHERN BRANCH AND HAVE SIGNIFICANTLY BACKED OFF THE WINDS AS COMPARED TO YESTERDAYS RUNS. AFTER THIS WAVE PASSES... RIDGING TAKES OVER FOR A SPELL. MODEL CONSISTENCY DECREASES BY THE WEEKEND IN THE HANDLING OF THE LINGERING SOUTHERN ENERGY. FOR THAT REASON...HAVE KEPT THE CURRENT TEMPERATURE FORECAST BELOW GUIDANCE FOR FRIDAY AND BEYOND...BUT TEMPS MAY NEED TO BE RAISED IF THIS BENIGN WX TREND CONTINUES. && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. $$ CJC/JOE/EH co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 409 AM EDT MON APR 23 2007 .SYNOPSIS... THE 03 UTC REGIONAL SURFACE ANALYSIS SHOWS A HIGH PRESSURE RIDGE FROM THE WESTERN ATLANTIC TO THE GULF COAST OF LA. VAPOR IMAGERY AND UPPER AIR PROFILER DATA SHOW RIDGING OVER THE SOUTHEAST AS A SHORT WAVE TROUGH MOVES QUICKLY NORTHEASTWARD OVER THE GREAT LAKES REGION...AND A CLOSED LOW MOVES SLOWLY EASTWARD OVER NV. SO FAR THERE HAVE BEEN NO REPORTS OF SMOKE AT OUR OBSERVING STATIONS IN SOUTH CENTRAL GA...AND THE LATEST NUMERICAL GUIDANCE KEEPS SURFACE SMOKE JUST EAST OF OUR FORECAST AREA TODAY AS THE BOUNDARY LAYER FLOW BECOMES SOUTHERLY. && .SHORT TERM... (TODAY-WEDNESDAY) THE 00 UTC NUMERICAL GUIDANCE IS IN GOOD AGREEMENT IN FORECASTING NEAR AVERAGE TEMPERATURES THROUGH THE PERIOD WITH DEEP LAYER RIDGING OVER THE SOUTHEAST. THERE WILL BE SLIGHT POPS (20 PERCENT) FOR OUR GA AND AL COUNTIES TUESDAY AS A WEAK UPPER LEVEL DISTURBANCE (ACCOMPANIED BY AN AREA OF DEEP LAYER MOISTURE) MOVES QUICKLY EAST OVER THIS AREA. 20-40 PERCENT POPS ARE FORECAST FOR WEDNESDAY AS A COLD FRONT SLOWLY APPROACHES FROM THE WEST AND DEEP LAYER MOISTURE INCREASES. .LONG TERM... (THURSDAY-MONDAY) THE ECMWF AND GFS FORECAST THE WEAK COLD FRONT TO MOVE SLOWLY THROUGH OUR AREA FRIDAY. OUR RAIN CHANCES WILL BE IN THE 30-50 PERCENT RANGE THURSDAY AND FRIDAY. THE SYSTEM LOOKS IMPRESSIVE TO OUR WEST...BUT THE GUIDANCE SHOWS IT IN A WEAKENING TREND BY THE TIME IT MOVES THROUGH ON FRIDAY. THE WEEKEND LOOKS WARM AND DRY WITH NEAR AVERAGE TEMPERATURES. && .AVIATION... HIGH PRESSURE RIDGE OVER THE AREA WILL MAINTAIN VFR CONDITIONS THROUGHOUT THE FORECAST. WITH THE SURFACE WINDS VEERING AROUND TOWARD THE SOUTH...THE SMOKE PLUME FROM WARE COUNTY WILL REMAIN WELL EAST OF THE TERMINALS. THE VERTICAL WIND PROFILE FROM THE MOODY RADAR INDICATES 20 TO 30 KNOT WINDS OUT OF THE SOUTH UP TO 6 TO 8 KFT. EXPECT THESE WIND CONDITIONS TO CONTINUE THROUGH THE MAJORITY OF THE PERIOD. THEREFORE...BACKED-OFF FROM THE PREVIOUS IFR VSBY FORECAST TO MVFR FOR THE KVLD SITE. && .MARINE... WINDS AND SEAS HAVE NOT INCREASED LIKE WE THOUGHT THEY WOULD...BUT THE RUC MAINTAINS THEY WILL SHORTLY...AND WE USUALLY DO GET A NOCTURNAL SURGE TOWARD DAYBREAK. WE NOW THINK WINDS AND SEAS WILL REMAIN JUST BELOW CAUTION LEVELS THIS MORNING. && .FIRE WEATHER... THE MOS HAVE HAD A TENDENCY TO BE TOO MOIST IN THEIR DEWPOINT FORECASTS THIS SEASON...AND THIS HAPPENED AGAIN SUNDAY AFTERNOON. THE NAM FORECAST SOUNDINGS AND LOCAL WRF SHOW VERY DRY AIR ALOFT (SIMILAR TO SUNDAY)...AND WE EXPECT TO ONCE AGAIN MIX INTO THIS AIR. THUS WE UNDERCUT THE GUIDANCE DEWPOINTS BY ABOUT 5-8 DEGREES...AND EXPANDED OUR RED FLAG WARNING FOR TODAY TO INCLUDE OUR GA ZONES. IT WILL BE MARGINAL IN GA...BUT HAVE FOUND THAT IT IS USUALLY BEST TO GO WITH WARNINGS IN THESE CASES. WE ALSO UNDERCUT THE DEWPOINTS FOR TUESDAY...BUT LEFT THE WATCH ALONE FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 52 83 56 84 63 / 0 10 10 10 20 PANAMA CITY 60 79 64 80 66 / 10 10 10 20 30 DOTHAN 56 83 61 83 64 / 10 20 10 20 40 ALBANY 56 82 58 84 63 / 10 20 10 10 30 VALDOSTA 52 83 57 83 63 / 0 10 10 10 20 CROSS CITY 52 84 56 84 61 / 0 10 10 10 20 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR ALL ZONES. FL...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 8 PM EDT THIS EVENING FOR THE FOLLOWING ZONES: DIXIE...GADSDEN... JEFFERSON...LAFAYETTE...LEON...LIBERTY...MADISON...TAYLOR... WAKULLA. FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR THE FOLLOWING ZONES: DIXIE...GADSDEN... JEFFERSON...LAFAYETTE...LEON...LIBERTY...MADISON...TAYLOR... WAKULLA. GMZ750...NONE. GMZ755...NONE. GMZ770...NONE. GMZ775...NONE. && $$ AVIATION...GIBBS REST OF DISCUSSION...FOURNIER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 345 AM EDT MON APR 23 2007 .DISCUSSION...TODAY/TONIGHT...DLM LARGE RIDGE AXIS BUILDING OFF THE SE/MID ATLC COAST WILL GENERATE A STEADY E/SELY FLOW ACROSS THE FL PENINSULA THRU DAYBREAK TUE. THE 00Z SOUNDINGS ALL MEASURED A MASSIVE SUBSIDENCE INVERSION IN THE H90-H60 LYR...WHILE LATEST RUC ANALYSIS SHOWS THE UPSTREAM AIRMASS OVER WRN ATLC TO BE FAR TOO DRY TO SUPPORT A SCT STRATOCU DECK...MUCH LESS ANY RAINFALL. THE STEADY EASTERLY FLOW WILL KEEP MAX TEMPS BLO CLIMO ALONG TEH COASTAL COUNTIES AND NEAR CLIMO INLAND...MIN TEMPS WILL BE ABV CLIMO COASTAL AND NEAR CLIMO INLAND. TUE-THU...ANTICYCLONE WILL REMAIN INTACT ALOFT THROUGH MID WEEK THEN WILL SHIFT OFFSHORE THU AS DEEPENING TROUGH REACHES THE MS RIVER VALLEY. MEANWHILE...SURFACE RIDGE NORTH OF THE REGION TUE SETTLES TO CENTRAL PENINSULA WED AND TO NEAR LAKE OKEECHOBEE LATITUDE THU...RESULTING IN LIGHT ONSHORE/EAST WINDS INITIALLY...VEERING TO SOUTHERLY COMPONENT. AIRMASS WILL REMAIN DRY TUE/WED THEN WILL BEGIN TO MOISTEN THU AS WINDS VEER AND TAP HIGHER MOISTURE SOURCE. WITH LIMITED LIFT HOWEVER...WILL STAY WITH DRY FORECAST. TEMPS WILL BE NEAR TO SLIGHTLY BELOW CLIMO TUE...THEN WILL RISE SEVERAL DEGREES ABOVE CLIMO MOST AREAS WED-THU AS LOW LEVEL WINDS ACQUIRE MORE SOUTHERLY COMPONENT. FRI-SUN...UPPER TROUGH AXIS PASSES BY TO THE NORTH FRIDAY FOLLOWED BY BRIEF PERIOD OF FLATTENED MID LEVEL FLOW BEFORE NEXT WEAKER TROUGH AXIS APPROACHES OVER THE WEEKEND. ASSOCIATED SURFACE FRONT REACHES THE PANHANDLE FRI THEN LIKELY SLOWS/STALLS/WEAKENS OVER NORTHERN PENINSULA SAT. INCREASED MOISTURE DEPTH COMBINED WITH WEAK SYNOPTIC SCALE LIFT WARRANTS SMALL SHOWER/STORM CHANCES FRI-SAT PERIOD. WILL CONTINUE TO REMAIN BELOW 30-40 PERCENT GFS POP GUIDANCE GIVEN UNCERTAINTY OF SUPPORT REACHING CWA. HIGH PRESSURE REBUILDS EASTWARD TOWARD FLORIDA FROM THE GULF COAST SUNDAY. TEMPS AVERAGING SEVERAL DEGREES ABOVE CLIMO THROUGH THE PERIOD. && .AVIATION...VFR ALL SITES THRU 24/00Z...OCNL SFC WND G22KTS ALONG THE COAST S OF KMLB FM 16Z THRU 22Z. && .MARINE...RIDGE AXIS BUILDING SE INTO THE WRN ATLC WILL GENERATE A STEADY ERLY FLOW ACROSS THE LCL WATERS. WINDS WILL BE LIGHTER OVER THE NRN LEG GIVEN THEIR CLOSER PROXIMITY TO THE RIDGE AXIS...WHILE STRONGER WINDS OVR THE SRN LEG WILL WORK WITH AN ERLY SWELL TO PUSH COMBINED SEAS INTO THE CAUTIONARY RANGE. WAVEWATCH MODEL INITIALIZES THE SWELL A BIT TOO AGGRESSIVELY WITH SEAS IN THE 5-7FT RANGE THROUGH MOST OF THE DAY...ESPECIALLY GIVEN THE CURRENT READINGS FROM BUOY009 AND THE FT. PIERCE SCRIPPS BUOY. WILL CAP WINDS/SEAS OVER THE SRN LEG IN THE CAUTIONARY RANGE THRU 12Z TUE. ONSHORE FLOW GENERALLY AOB 15KT THROUGH MIDWEEK AS HIGH PRESSURE RIDGE REMAINS TO THE NORTH. RIDGE WILL SETTLE SOUTHWARD TO CENTRAL/SOUTH PENINSULA BY LATE IN THE WEEK...CAUSING WINDS TO VEER TO SOUTHERLY COMPONENT THU-FRI AHEAD OF FRONTAL BOUNDARY. BRIEF PERIOD OF STRONGER WINDS....15-20 KT...POSSIBLE ACROSS OFFSHORE WATERS THU. SEAS WILL REMAIN ELEVATED TUE...THEN WILL FALL AOB 4 FT WED-FRI. HAVE UNDERCUT WAVEWATCH SLIGHTLY EARLY IN THE PERIOD. && .FIRE WEATHER...SPLIT DECISION TODAY WRT UPGRADING THE FIRE WATCH TO A RED FLAG WARNING. GIVEN THE LOCATION OF THE SFC RIDGE AXIS OVER THE PANHANDLE/NRN PENINSULA...SFC WINDS WILL BE LIGHTER OVER THE NRN INTERIOR BUT SUPPRESSION WILL BE STRONGER...CONDITIONS THAT WOULD FAVOR A DURATION RFW. ON THE OTHER HAND...THE TIGHTER PGRAD OVER THE SRN HALF OF THE PENINSULA IS STRONG ENOUGH TO PRODUCE A 15KT EASTERLY FLOW ALONG THE COAST...WHICH WILL ADVECT MARINE MODIFIED AIR WELL INLAND THIS AFTN AND SHOULD PREVENT RH DURATIONS. HOWEVER...THE STRONGER WINDS OVER THE S WOULD BE VULNERABLE TO THE INSTANTANEOUS RFW CONDITION OF 15 MPH/35% RH. THE SITUATION IS MARGINAL...BUT GIVEN THE LATEST KBDI INDEXES ARE WELL OVER 500... WILL ERR ON THE SIDE OF CAUTION AND UPGRADE THE WATCH TO AN RFW FOR ALL INTERIOR COUNTIES FROM 12 NOON THRU 800 PM. MIN RH LIKELY TO REACH 40-45 PERCENT EACH AFTERNOON THROUGH MID-WEEK ACROSS THE INTERIOR AS LIGHT EASTERLY FLOW PREVAILS AND DIURNAL MIXING TAKES PLACE DURING TIME OF MAX HEATING. GIVEN HIGH KBDI VALUES ACROSS AREA...HEIGHTENED FIRE WX THREAT WILL CONTINUE... ALTHOUGH CRITERIA NOT EXPECTED TO REACH RED FLAG THRESHOLDS. && .PRELIMINARY POINT TEMPS/POPS... DAB 79 60 80 65 / 0 0 0 10 MCO 83 60 84 64 / 0 0 0 10 MLB 80 62 81 67 / 0 0 0 10 VRB 80 64 81 67 / 0 0 0 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...RED FLAG WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR INLAND VOLUSIA-NORTHERN LAKE-OKEECHOBEE-ORANGE-OSCEOLA- SEMINOLE-SOUTHERN LAKE. AM...NONE. && $$ SHORT TERM/AVIATION...BRAGAW LONG TERM....SPRATT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 337 AM EDT MON APR 23 2007 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE TIMING OF ENDING OF PRECIPITATION TODAY. WATER VAPOR IMAGERY AND RUC SHOWING A LOW MOVING OVER NORTHERN WISCONSIN....A RIDGE OVER THE NORTHERN PLAINS...AND A LOW DEEPENING OVER THE GREAT BASIN. A WEAK SHORTWAVE ACCOMPANYING THE WISCONSIN LOW IS ROTATING AROUND THE BASE OF THE LOW AND IS MOVING THROUGH THE FORECAST AREA. SURFACE ANALYSIS DEPICTS A COLD FRONT LINKING A LOW OVER NORTHERN WISCONSIN WITH A LOW OVER EAST CENTRAL ONTARIO. ANOTHER COLD FRONT DRAPES SOUTH OF THE WISCONSIN LOW THROUGH THE MIDDLE MISSISSIPPI RIVER VALLEY. A PAIR OF LOW CENTERS ARE DEVELOPING OVER THE ROCKIES AND HIGH PLAINS. ONE IS OVER EASTERN COLORADO AND THE OTHER IS OVER THE GREAT SALT LAKE. A HIGH PRESSURE CENTER IS BUILDING OVER CENTRAL CANADA. THE WISCONSIN LOW WILL WEAKEN AS IT SWEEPS ACROSS THE U.P. TODAY REACHING EAST CENTRAL ONTARIO BY LATE AFTERNOON. MEANWHILE...THE ACCOMPANYING SURFACE LOW WILL RACE TO WEST CENTRAL QUEBEC DRAGGING A THE COLD FRONT THROUGH MICHIGAN AND INTO THE LOWER GREAT LAKES REGION. THE CANADIAN HIGH WILL PUSH INTO CENTRAL MANITOBA AND BEGIN TO SPREAD INTO THE NORTHERN PLAINS. ANTI-CYCLONIC FLOW AHEAD OF THIS HIGH WILL DRAW COOLER DRY AIR INTO THE FORECAST AREA AGAIN. TRACKING THE SPEED AND MOVEMENT OF MID LEVEL LOW SHOWS THAT IT WILL BE OVER THE CENTRAL U.P. BY 12Z THIS MORNING. SATELLITE SHOWING THE WRAP AROUND MOISTURE IS ABOUT 3 HOURS BEHIND THE MID LEVEL CENTER. THUS BY 15Z DRIER AIR SHOULD REACH THE WESTERN U.P. AND BY 20Z MOST OF THE MOISTURE WILL BE OUT OF THE FORECAST AREA. CURRENT TIMING IN THE GRIDS LOOK REASONABLE. GFS/RUC/NAM AGREES WITH THIS TIMING. MODELS SHOWING STRONG DIVERGENCE SPREADING OVER THE AREA BY NOON. SHOWALTER INDEX CONTINUES TO SHOW <2 OVER SOUTH CENTRAL AND EASTERN U.P. EARLY THIS MORNING. ACCORDING TO THE SHOWALTER INDEX ONLY THE EASTERN U.P. WILL HAVE A POTENTIAL FOR THUNDERSTORMS BY 15Z. WEAK MUCAPE VALUES REMAIN ONLY OVER NORTHERN LAKE MICHIGAN. LI`S ALSO WILL BE WELL 4 AROUND 12Z. THIS WILL RAPIDLY INCREASE TO >10 BY 15Z. A COUPLE OF THUNDERSTORMS ARE OCCURRING OVER SOUTHERN WISCONSIN AT THIS TIME WHICH ALSO SUPPORTS THE POSSIBILITY OF A THUNDERSTORM OR TWO. A WEAK POTENTIAL REMAINS MAINLY OVER THE SOUTHERN AND EASTERN U.P. AFTER SUNRISE TODAY. MODELS ARE IN A FAIRLY GOOD AGREEMENT THROUGH WEDNESDAY. VARIATION ARE SHOWING UP ON THURSDAY TO THE WEST OF THE FORECAST AREA. I AGREE WITH HPC THAT THE NAM SHOWS THE BEST CONTINUITY AT 500MB WITH THE NEXT SYSTEM MOVING THROUGH THE GREAT LAKES SO WILL FAVOR THE NAM/CANADIAN ALOFT AND THE GFS/NAM/CANADIAN CONSENSUS AT THE SURFACE THROUGH 84 HOURS. THE SHORTWAVE OVER EASTERN ONTARIO WILL SHIFT EAST INTO QUEBEC TONIGHT. THE GREAT BASIN LOW WILL MIGRATE INTO MIDDLE HIGH PLAINS. THE SURFACE LOWS OVER THE ROCKIES WILL MERGE INTO A LOW OVER WESTERN KANSAS. THE CANADIAN HIGH WILL REMAIN OVER MANITOBA AND EXPAND INTO THE UPPER GREAT LAKES REGION BRINGING COOLER DRIER MORE SEASONAL AIR TO THE REGION. FORECAST SOUNDINGS SUGGEST SOME CIRRUS CLOUDS WILL BLANKET THE REGION TONIGHT OTHERWISE DRY BELOW 500MB. THE HIGH PLAINS CLOSED LOW WILL SHIFT EAST REACHING INTO THE MIDDLE MISSISSIPPI RIVER VALLEY ON THURSDAY. THE KANSAS SURFACE LOW WILL SLOWLY WORK ITS WAY EAST REACHING INTO THE SOUTHERN OHIO RIVER VALLEY ON THURSDAY. THE SURFACE RIDGE OVER CANADA WILL SETTLE OVER THE UPPER UPPER GREAT LAKES AND REMAIN THROUGH THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 156 AM EDT MON APR 23 2007 .AVIATION...WINDS HAVE INCREASED TO 55KTS AT 3KFT ABOVE THE SURFACE THIS EVENING ACCORDING TO THE RADAR JUSTIFYING THE LLWS OVERNIGHT FOR ALL TAF SITES. OTHERWISE...A PREFRONTAL BAND OF LIGHT RAIN SHOWERS ACROSS LAKE MICHIGAN HAS BEEN TIMED TO ENTER NW LOWER MICHIGAN AFTER MIDNIGHT. THIS BAND HAS BEEN SLOWLY DIMINISHING AS IT RUNS INTO VERY DRY AIR ACROSS THE LAKES...AND BELIEVE THESE SHOWERS WILL RUN OUT OF STEAM PRIOR TO REACHING TVC/PLN. SHOWERS AND ISOLATED TSTORMS (WITH MVFR VSBYS) WILL ARRIVE LATE TONIGHT AS A COLD FRONT APPROACHES THE AREA...BUT THE BULK OF THE RAIN WILL OCCUR BETWEEN DAYBREAK AND NOON (MVFR CIGS...MVFR TO HIGH-END IFR VSBYS). STRONG DRYING BEHIND THE SYSTEM WILL RESULT IN A RETURN TO VFR CONDITIONS BY EARLY AFTERNOON WHICH WILL LAST THROUGH THE EVENING. MPC && .UPDATE...ISSUED AT 1035 PM EDT SUN APR 22 LATEST RUC/SURFACE ANALYSIS AND IR/WV/RADAR IMAGERY SHOW A PLETHORA OF SURFACE LOWS...ONE OVER FAR WESTERN IOWA...ANOTHER OVER NORTHERN WISCONSIN...AND A LAST ONE OVER QUEBEC...ALL LOCATED ALONG A COLD FRONT BEING PUSHED SLOWLY EAST BY A POTENT SHORTWAVE WHICH LIES OVER NW IOWA. A BAND OF SHOWERS AND A FEW THUNDERSTORMS HAVE BEEN PROGRESSING STEADILY NW ALONG AN UPPER LEVEL FRONT ROUGHLY PLACED AT AROUND 700MB AS SHOWN ON THE 00Z DVN SOUNDING. A SLOW WEAKENING TREND HAS BEEN NOTED WITH THE SHOWERS AS THEY RUN INTO THE VERY DRY AIR MASS OVER THE GREAT LAKES (13C/18C DEWPOINT DEPRESSIONS AT 700MB FROM 00Z GRB/APX SOUNDINGS). SURFACE TEMPS HAVE SLOWLY COOLED INTO THE UPPER 60S TO LOW 70S THIS EVENING...AND HAVE ALLOWED THE RED FLAG WARNING TO EXPIRE AT ITS DESIGNATED TIME. MAIN FORECAST CONCERNS REVOLVE AROUND SHOWER AND THUNDERSTORM POTENTIAL THIS EVENING. COMPLEX SCENARIO SHAPING UP FOR THE OVERNIGHT HOURS. MODELS ARE NOT CAPTURING THE SHOWERS ALONG THE UPPER LEVEL FRONT WELL AS THE NAM/GFS BOTH WANT TO KEEP THE MID-LEVELS DRY DESPITE THE UPSTREAM CONDITIONS. WILL LEAN AWAY FROM THE MODELS WITH THIS FORCING INITIALLY. LEADING BAND OF SHOWERS TIMED TO APPROACH SW LOWER MICHIGAN BY AROUND MIDNIGHT OR SO...BUT WILL THEY HOLD TOGETHER THROUGH THE DRY AIR? STEEP MID-LEVEL LAPSE RATES OF 7-7.5C/KM LIE AHEAD OF THE BAND DUE TO A WARM NOSE AT 700MB SHOWN ON GRB/APX SOUNDINGS. BUT DESPITE THIS INSTABILITY...THE DRY AIR APPEARS TO BE WINNING OUT JUDGING BY LATEST RADAR TRENDS. WILL INTRODUCE A 30 PCT CHANCE OF LIGHT RAIN SHOWERS ACROSS THE SOUTHWEST CWA TO ACCOUNT FOR THIS. OTHERWISE...STRONG SHORTWAVE LOOKS TO REACH WISCONSIN AND CENTRAL UPPER WITH THE COLD FRONT DRAPED FROM GRB TO WHITEFISH POINT BY 12Z. FORCING DUE TO INCREASING UPPER LEVEL DIVERGENCE AND -DIV Q LOOK TO SPREAD A BAND OF SHOWERS ACROSS NORTHWEST LOWER AND EASTERN UPPER BETWEEN 09Z-12Z. A CHANCE OF THUNDER STILL REMAINS POSSIBLE WITH 700-500MB LAPSE RATES BETWEEN 6-6.5C/KM. BUT BULK OF THE PRECIP LOOKS TO ARRIVE AFTER THE FRONTAL PASSAGE DURING THE MORNING. ZONES OUT SHORTLY. MPC && .PREVIOUS DISCUSSION...ISSUED AT 320 PM EDT SUN APR 22 THE MAIN 500 MB RIDGE IS BREAKING DOWN AS THE 500 MB SHORTWAVE TROUGH IS BEGINNING TO MAKE ITS MOVE TOWARD THE GREAT LAKES. THIS IS ADDING SOME UMPH TO THE COLD FRONT IN MINNESOTA THAT IS EXPECTED TO PUSH THROUGH THE REGION TONIGHT. WITH THE SFC LOWS ATTACHED TO THE FRONT AND FORMER HUDSON BAY HIGH, NOW TRANSITIONING TO A BERMUDA HIGH, ANOTHER CRITICAL FIRE WEATHER PATTERN, PROVIDING A STRONG PRESSURE GRADIENT BOOSTING WINDS DURING THE DAY. TONIGHT...THE MAIN CONCERNS FOR THE NEAR TERM PART OF THE FORECAST PACKAGE WILL THE CESSATION OF THE RED FLAG AND THE COMMENCEMENT OF THUNDERSTORMS DURING THE OVERNIGHT. LOOKING AT THE CURRENT TREND FOR THE FIRE WEATHER, WILL LET THE WARNING RIDE UNTIL 00Z. WHILE THE MAIN PART OF THE RISK LOOKS LIKE IT COULD BE DONE AROUND 22Z A FEW SITES MAY STAY A LITTLE LONGER (LIKE 00Z). THUNDER STORMS ARE THE NEXT THING TO TACKLE. WITH THE DRY AIR IN PLACE IT WILL TAKE A WHILE FOR THE MOISTURE TO MOVE INTO THE REGION. THE GFS LOOKS A LITTLE GOOFY WITH A FEW, WHAT LOOKS FEEDBACK DRIVEN, SHORTWAVE TROUGHS IN THE FLOW. IF THE GFS WOULD BE BELIEVED, THE THUNDER WOULD BE IN BY 06Z AND THE LIKELY TO CATEGORICAL POPS WOULD WORK, BUT THE NAM WITH NO EVIDENT FEEDBACK, LOOKS BETTER. SO HAVE GONE WITH CHANCE POPS IN THE WEST ZONES. TEMPERATURES WILL BE WARM, BUT SHOULD FALL A BIT AS THE WINDS DECOUPLE AND THE SKIES REMAIN CLEAR. THIS SHOULD HELP PREVENT ANY SFC BASED CONVECTION IN THE MORNING. LUTZ MONDAY...MODEL DATA SHOWING A STORM SYSTEM EAST OF HUDSON BAY... WITH AN ASSOCIATED COLD FRONT MOVING OVER THE UPPER MIDWEST SUNDAY NIGHT CONTINUING TO MOVE EAST INTO THE WRN LAKES MONDAY MORNING. THIS FEATURE WILL SWEEP OVR THE STATE MONDAY...EXITING EAST INTO LAKE HURON IN THE EVENING. 500 MB UPPER TROUGH WILL SWEEP OVER THE STATE DURING THE DAY...WITH NEARLY ZONAL FLOW DEVELOPING OVER THE STATE BEHIND THE TROF IN THE EVENING. THE SYSTEM IS WORKING ITSELF INTO A PRETTY DRY AIRMASS WHICH WILL BE OVR THE STATE INTO THE EARLY MORNING HOURS OF MONDAY...HOWEVER MODEL SOUNDINGS SHOW THE ATMOSPHERIC MSTR INCREASING SHORTLY AFTER 12Z. 850/500MB RH INCREASES TO OVR 80 PCT ACRS THE CWA BY 15Z. WILL MENTION LIKELY/CAT POPS IN THE MORNING ACROSS THE FORECAST AREA...DIMINISHING POPS TO CHC OVER THE WRN CWA BY THE AFTERNOON...AS THE SURFACE AND UPPER LEVEL FEATURES PROGRESS EAST. TUESDAY...WILL MAINTAIN DRY CONDS TUESDAY AS SURFACE RIDGING BUILDS OVER THE UPPER LAKES...WITH NEARLY ZONAL FLOW ALOFT. TUESDAY NIGHT...HIGH PRESSURE RIDGING WILL REMAIN OVER THE UPPER LAKES WHILE A STORM SYSTEM MOVES FROM THE CENTRAL PLAINS AND INTO THE NRN OHIO VALLEY TUESDAY NIGHT/EARLY WEDNESDAY MORNING. SOUNDING DATA AND 850/500 MB MSTR PROGS...SHOW RH INCREASING TO 70 PCT OVR THE SAGINAW BAY REGION...WITH THE REST OF FCST AREA REMAINING MUCH DRIER IN THE SUBSIDENCE TO THE NORTH. WILL MENTION A CHC OF PCPN FOR THE EXTREME SRN PORTIONS OF THE FORECAST AREA TUESDAY NIGHT. WEDNESDAY...HIGH PRESSURE FROM THE NORTH...DROPS SOUTH OVR THE ENTIRE FORECAST AREA IN THE MORNING...AS THE OHIO VALLEY STORM SYSTEM CONTINUES ITS SLOW PROGRESSION TOWARD THE EAST COAST. UPPER LVLS SHOW AN UPPER TROF MOVING OVER THE LAKES REGION IN THE AFTERNOON. HOWEVER SOUNDING DATA SHOWS DRY CONDS LINGERING OVER THE NRN LAKES...WITH 850/500MB RH LINGERING AROUND 40 PCT. THEREFORE WILL MENTION DRY CONDS ACRS THE CWA. WILL MAINTAIN HIGHS IN THE MID 50S...AS 850 TEMPS INDICATE A COOL POOL ALOFT WITH 850 TEMPS ARND -1C. THURSDAY THRU SUNDAY... THURSDAY...A STORM SYSTEM WILL PASS SOUTH OF THE FCST AREA THROUGH THE OHIO VALLEY. RESULTANT HIGH PRESSURE WILL BE IN PLACE OVER THE NRN LAKE REGION. 500MB PATTERN...SHOWS AN UPPER TROUGH MOVING OVER THE UPPER LAKES THURSDAY MOVING EAST OF LAKE HURON IN THE AFTERNOON. 850/700MB RH AND MODEL SOUNDINGS SHOWING DRY LOW LEVELS WITH SOME INCREASE IN MID LVL MSTR NOTED IN ADVANCE OF THE UPPER TROF. HOWEVER LOW LVLS...AROUND 30 PCT BTW 850/700...LOOK TO REMAIN TO DRY FOR PCPN MOST OF THE CWA AS THE WAVE PASSES OVERHEAD. THEREFORE WILL TRIM POP CHCS BACK. WILL MENTION HIGHS IN THE LOW TO MID 50S ACRS THE CWA...AS SOME COOLER AIR MOVES IN ALOFT IN THE UPPER TROF...850 TEMPS TO ARND 0C. WILL DROP OVERNIGHT LOWS A TAD BTW GRAYLING AND MIO IN THE JACK PINE FLATS WHERE DRY SANDY SOIL...LIGHT WINDS AND CLEAR SKIES TYPICALLY ALLOW FOR GOOD COOLING. FRIDAY...WEAK UPPER RIDGING PATTERN WILL BE PRESENT ACRS THE STATE. AT THE SFC...HIGH PRESSURE WILL BE LOCATED OVER THE STATE AND MUCH OF THE ERN THIRD OF THE COUNTY...WHILE A STORM SYSTEM MOVES EAST ACRS NRN CANADA AND INTO HUDSON BAY. SOUNDING DATA AND 850/700 MSTR PROGS (ARND 40 PCT 850/700) SHOWING DRY CONDS TO PERSIST OVR THE GREAT LAKES REGION THROUGH FRIDAY NIGHT. WILL MENTION WARMER AFTERNOON TEMPERATURES FRIDAY...DUE TO AFTN SUNSHINE...AND UPPER RIDGING BUILDS BACK INTO THE STATE WARMING 850 TEMPS WARMING TO +4C. ONCE AGAIN WILL DROP OVERNIGHT LOWS A TAD BTW GRAYLING AND MIO IN THE SANDY SOIL JACK PINE FLATS AREAS. SATURDAY/SUNDAY...MODEL DATA WITH SOME DIFFERENT SOLUTIONS IN SFC AND UPPER LVL PATTERNS THROUGH THE END OF THE PERIOD. OVERALL TREND IS FOR RIDGING TO REMAIN OVER THE ATLANTIC COAST EXTENDING BACK INTO THE OHIO VALLEY AND MIDWEST...WITH A STORM SYSTEM REMAINING ARND HUDSON BAY WITH ITS ASSOCIATED COLD FRONT TRYING TO MOVE OVER THE CENTRAL PLAINS AND UPPER MIDWEST TWD THE WRN LAKES. CURRENTLY LOOKS LIKE BEST CHC FOR PCPN WILL BE SATURDAY WHEN MSTR INCREASES A LITTLE IN ADVANCE OF AN UPPER TROUGH MOVING OVER THE STATE. THEREFORE WILL KEEP A CHC OF PCPN SATURDAY MOST ZONES. OTHERWISE SFC RIDGING AND WEAK UPPER RIDGING WILL BE THE MAIN FEATURES INTO SUNDAY...SO WILL MENTION DRY CONDS INTO THE END OF THE FORECAST PERIOD. WILL MENTION HIGHS IN THE UPPER 50S AND LOWER 60S DUE TO SOME SUN AND SOUTHERLY FLOW DEVELOPING. SWR && .APX WATCHES/WARNINGS/ADVISORIES...NONE && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 1057 AM CDT MON APR 23 2007 .DISCUSSION... DESPITE DIRTY RIDGING ATOP THE AREA LATE THIS MORNING...ISOLATED SHOWERS ARE FORMING OVER SCNTRL/NE LA...WHERE CURRENT ANALYSIS INDICATES ANOTHER SFC-850MB THETA-E RIDGE WHICH HAS DEVELOPED OVER THESE AREAS. MOISTURE REMAINS SHALLOW...ROUGHLY BELOW 9KFT...AND MODEL FORECAST SOUNDINGS SUGGEST THAT CURRENT STRONG CAPPING INVERSION NOTED ON THE 12Z KSHV RAOB WILL HOLD THROUGH THE AFTERNOON...THUS LIMITING SUSTAINED DEVELOPMENT. 15Z LAPS ANALYSIS ALSO INDICATES LOWEST CIN WHERE SHOWERS ARE ALREADY DEVELOPING...WHICH COINCIDES WELL WITH THE CU FIELD THAT IS SCATTERING OUT/TEMPS ARE HEATING UP. NOT TOO SURE IF WE WILL SEE MUCH DEVELOPMENT OVER E TX GIVEN HIGHER CIN/MORE EXTENSIVE CLOUD COVER...BUT HAVE ADDED SLIGHT CHANCE POPS FOR ALL N LA EXCEPT THE EXTREME NW SECTIONS /I.E. SHV/...AND ALSO DEEP E TX WHERE THE RUC/12Z NAM INDICATE ADDITIONAL THETA-E RIDGING THIS AFTERNOON....IN THE LATE MORNING ZONE UPDATE. ALSO ADJUSTED SKY CONDITIONS TO BEEF UP CLOUD COVER OVER E TX/SE OK...AND ALSO MADE VERY MINOR TWEAK TO THE MAX TEMPS GRIDS THIS AFTERNOON. BUT OTHERWISE...FORECAST REMAINS ON TRACK. SHORTWAVE STILL PROGGED TO LIFT NE THROUGH NE TX/SE OK/SW AR TONIGHT...WITH SCATTERED TO NUMEROUS CONVECTION DEVELOPING TUESDAY AS THE CLOSED LOW DRIFTS E INTO E CO/TX-OK PANHANDLE REGION. BUT MORE ON THIS...AND THE POTENTIAL OF SVR STORMS...IN THE AFTERNOON DISCUSSION. UPDATE ALREADY OUT. 15 && .AVIATION... SEVERAL CLOUD LAYERS ACROSS REGION AT THIS TIME. CONDITIONS IMPROVING TO VFR AFT 23/16Z. SOUTHERLY WINDS 5 TO 10 KTS INCREASING TO THE 10 TO 15 KT RANGE BY 16Z. /23/ && .PRELIMINARY POINT TEMPS/POPS... SHV 83 67 78 65 / 10 20 40 60 MLU 81 65 80 65 / 20 20 30 50 DEQ 79 65 75 64 / 10 20 60 60 TXK 80 67 76 64 / 10 20 50 60 ELD 82 65 78 64 / 20 20 40 60 TYR 80 67 76 64 / 10 20 50 60 GGG 81 67 76 64 / 10 20 50 60 LFK 82 68 78 66 / 20 20 40 60 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 15/23 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1043 AM EDT MON APR 23 2007 .UPDATE... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW WEAKENING SHORTWAVE MOVING ACROSS LAKE MI TO LWR MI WITH A SECOND SHORTWAVE TROF EXTENDING FROM JAMES BAY TOWARD ISLE ROYALE. AT THE SFC...COLD FRONT EXTENDS FROM NEAR KGRB TO NEAR SAULT STE MARIE. EVEN THOUGH FRONT HAS CLEARED THE FCST AREA...-SHRA/-RA LINGER OVER CNTRL/ERN UPPER MI...BUT THE PCPN IS QUICKLY MOVING E. UPSTREAM...SKIES HAVE ALREADY CLEARED OVER WRN LAKE SUPERIOR...BUT THERE IS ANOTHER BATCH OF MOISTURE/CLOUDS JUST NW OF LAKE SUPERIOR HEADING SE. AREA OF -SHRA/-RA OVER CNTRL/ERN UPPER MI LINES UP WELL WITH 850-700MB FRONTOGENESIS LOCATED JUST BEHIND SFC FRONTAL BOUNDARY. AS SHORTWAVE CONTINUES TO HEAD E...FORCING WILL ALSO EXIT THE AREA. BASED ON LINEAR EXTRAPOLATION OF RADAR IMAGERY OVER THE LAST COUPLE OF HRS...THE LAST OF THE -SHRA/-RA SHOULD EXIT THE FAR ERN FCST AREA AROUND 17Z. INHERITED FCST HAD A GOOD HANDLE ON THAT. AS FOR CLOUDS...ANY BREAKS IN THE CLOUD COVER THRU EARLY AFTN WILL LEAD TO ADDITIONAL STRATOCU DEVELOPMENT UNTIL LOW-LEVEL MOISTURE CAN BE SCOURED OUT. IN ADDITION...BATCH OF MOISTURE/STRATOCU NW OF LAKE SUPERIOR SUGGESTS SKIES PROBABLY WON`T CLEAR OUT COMPLETELY THIS AFTN. ONLY EXCEPTION SHOULD BE OVER THE FAR W AS MESOHIGH PRES DEVELOPS OVER THE LAKE OWING TO INCREASING LAKE/LAND TEMP DIFFERENCE. RESULTING SUBSIDENCE/DIVERGENT FLOW WILL ALLOW FOR SKIES TO CLEAR NEAR THE SHORE AS THE AFTN PROGRESSES. OTHERWISE...THERE SHOULD BE A VERY GRADUAL DECREASE IN OVERALL CLOUD COVER FROM W TO E THRU THE AFTN WITH ANY LINGERING STRATOCU DISSIPATING EARLY THIS EVENING. TEMPS TODAY WILL BE CONSIDERABLY COOLER THAN YESTERDAY... ESPECIALLY NEAR LAKE SUPERIOR. STIFF NW WIND ACROSS ERN LAKE SUPERIOR SHOULD KEEP TEMPS IN THE LWR/MID 40S ALONG THE LAKE E OF MARQUETTE THRU THE AFTN. BASED ON 12Z SOUNDINGS...HIGHS SHOULD TOP OUT AROUND 60/LWR 60S OVER THE SW PORTION OF FCST AREA. OTHERWISE... 50S WILL BE THE RULE MOST AREAS TODAY. && .PREV DISCUSSION (ISSUED AT 337 AM EDT)... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE TIMING OF ENDING OF PRECIPITATION TODAY. WATER VAPOR IMAGERY AND RUC SHOWING A LOW MOVING OVER NORTHERN WISCONSIN....A RIDGE OVER THE NORTHERN PLAINS...AND A LOW DEEPENING OVER THE GREAT BASIN. A WEAK SHORTWAVE ACCOMPANYING THE WISCONSIN LOW IS ROTATING AROUND THE BASE OF THE LOW AND IS MOVING THROUGH THE FORECAST AREA. SURFACE ANALYSIS DEPICTS A COLD FRONT LINKING A LOW OVER NORTHERN WISCONSIN WITH A LOW OVER EAST CENTRAL ONTARIO. ANOTHER COLD FRONT DRAPES SOUTH OF THE WISCONSIN LOW THROUGH THE MIDDLE MISSISSIPPI RIVER VALLEY. A PAIR OF LOW CENTERS ARE DEVELOPING OVER THE ROCKIES AND HIGH PLAINS. ONE IS OVER EASTERN COLORADO AND THE OTHER IS OVER THE GREAT SALT LAKE. A HIGH PRESSURE CENTER IS BUILDING OVER CENTRAL CANADA. THE WISCONSIN LOW WILL WEAKEN AS IT SWEEPS ACROSS THE U.P. TODAY REACHING EAST CENTRAL ONTARIO BY LATE AFTERNOON. MEANWHILE...THE ACCOMPANYING SURFACE LOW WILL RACE TO WEST CENTRAL QUEBEC DRAGGING A THE COLD FRONT THROUGH MICHIGAN AND INTO THE LOWER GREAT LAKES REGION. THE CANADIAN HIGH WILL PUSH INTO CENTRAL MANITOBA AND BEGIN TO SPREAD INTO THE NORTHERN PLAINS. ANTI-CYCLONIC FLOW AHEAD OF THIS HIGH WILL DRAW COOLER DRY AIR INTO THE FORECAST AREA AGAIN. TRACKING THE SPEED AND MOVEMENT OF MID LEVEL LOW SHOWS THAT IT WILL BE OVER THE CENTRAL U.P. BY 12Z THIS MORNING. SATELLITE SHOWING THE WRAP AROUND MOISTURE IS ABOUT 3 HOURS BEHIND THE MID LEVEL CENTER. THUS BY 15Z DRIER AIR SHOULD REACH THE WESTERN U.P. AND BY 20Z MOST OF THE MOISTURE WILL BE OUT OF THE FORECAST AREA. CURRENT TIMING IN THE GRIDS LOOK REASONABLE. GFS/RUC/NAM AGREES WITH THIS TIMING. MODELS SHOWING STRONG DIVERGENCE SPREADING OVER THE AREA BY NOON. SHOWALTER INDEX CONTINUES TO SHOW <2 OVER SOUTH CENTRAL AND EASTERN U.P. EARLY THIS MORNING. ACCORDING TO THE SHOWALTER INDEX ONLY THE EASTERN U.P. WILL HAVE A POTENTIAL FOR THUNDERSTORMS BY 15Z. WEAK MUCAPE VALUES REMAIN ONLY OVER NORTHERN LAKE MICHIGAN. LI`S ALSO WILL BE WELL 4 AROUND 12Z. THIS WILL RAPIDLY INCREASE TO >10 BY 15Z. A COUPLE OF THUNDERSTORMS ARE OCCURRING OVER SOUTHERN WISCONSIN AT THIS TIME WHICH ALSO SUPPORTS THE POSSIBILITY OF A THUNDERSTORM OR TWO. A WEAK POTENTIAL REMAINS MAINLY OVER THE SOUTHERN AND EASTERN U.P. AFTER SUNRISE TODAY. MODELS ARE IN A FAIRLY GOOD AGREEMENT THROUGH WEDNESDAY. VARIATION ARE SHOWING UP ON THURSDAY TO THE WEST OF THE FORECAST AREA. I AGREE WITH HPC THAT THE NAM SHOWS THE BEST CONTINUITY AT 500MB WITH THE NEXT SYSTEM MOVING THROUGH THE GREAT LAKES SO WILL FAVOR THE NAM/CANADIAN ALOFT AND THE GFS/NAM/CANADIAN CONSENSUS AT THE SURFACE THROUGH 84 HOURS. THE SHORTWAVE OVER EASTERN ONTARIO WILL SHIFT EAST INTO QUEBEC TONIGHT. THE GREAT BASIN LOW WILL MIGRATE INTO MIDDLE HIGH PLAINS. THE SURFACE LOWS OVER THE ROCKIES WILL MERGE INTO A LOW OVER WESTERN KANSAS. THE CANADIAN HIGH WILL REMAIN OVER MANITOBA AND EXPAND INTO THE UPPER GREAT LAKES REGION BRINGING COOLER DRIER MORE SEASONAL AIR TO THE REGION. FORECAST SOUNDINGS SUGGEST SOME CIRRUS CLOUDS WILL BLANKET THE REGION TONIGHT OTHERWISE DRY BELOW 500MB. THE HIGH PLAINS CLOSED LOW WILL SHIFT EAST REACHING INTO THE MIDDLE MISSISSIPPI RIVER VALLEY ON THURSDAY. THE KANSAS SURFACE LOW WILL SLOWLY WORK ITS WAY EAST REACHING INTO THE SOUTHERN OHIO RIVER VALLEY ON THURSDAY. THE SURFACE RIDGE OVER CANADA WILL SETTLE OVER THE UPPER UPPER GREAT LAKES AND REMAIN THROUGH THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON (UPDATE) DLG (PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 1123 AM EDT MON APR 23 2007 .SHORT TERM /REST OF TODAY/... BUSY DAY WITH FIRE WEATHER ISSUES. 5 SPOT FORECASTS FOR PRESCRIBED BURNS SO FAR. RED FLAG WARNING FOR PA DUE TO LOWER WIND CRITERIA. SIMILAR CONDITIONS IN NY BUT WIND CRITERIA IS 25 MPH. UPDATE TO BUMP TEMPS UP A FEW DEGREES. TEMPS HAVE RISEN QUICKLY INTO 70S WITH LOW AND MID 80S EXPECTED. REMOVED POPS FROM THE EARLY AFTN BASED ON THE 12Z NAM AND RUC. SHOWERS AND MAYBE A TS LATE AFTN INTO TONIGHT. LIS CLOSE TO ZERO AND MID LEVEL LAPSE RATES GOOD FOR A FEW HOURS RIGHT ALONG THE FRONT. MOISTURE WITH THE FRONT IS LACKING WITH SFC DEWPOINTS RISING ONLY INTO THE U40S. && .PREV DISCUSSION... /ISSUED 635 AM EDT MON APR 23 2007/ AVIATION /12Z-12Z/... VFR CONDITIONS EXPECTED. LIGHT WINDS WILL INCREASE OUT OF THE SOUTH-SOUTHWEST AROUND NOON, WITH GUSTS TO 20-25 KTS POSSIBLE. SCATTERED SHOWERS WILL MOVE INTO THE REGION AFTER NIGHTFALL. DJP PREV DISCUSSION... /ISSUED 254 AM EDT MON APR 23 2007/ SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... WAVE MOVING THROUGH UPPER MIDWEST WITH ATTENDANT SFC CYCLONE WILL CONTINUE TO OPEN AS IT PULLS NORTHEAST NEXT 24 HOURS. AHEAD OF THE FRONT HIGH PRESSURE IS SLOWLY YIELDING CONTROL OVER THE MID ATLANTIC STATES. THE INCREASED GRADIENT BETWEEN THE COMPETING SYSTEMS WILL STRENGTHEN WINDS ACROSS OUR FORECAST AREA TODAY. WITH THE AIR STILL DRY OVER MUCH OF THE NORTHEAST, AND ONLY A MARGINAL RISE IN DEW POINTS EXPECTED THIS AFTERNOON IN SOUTHERLY FLOW, EXPECT THE WINDS WILL CAUSE A GREATER DANGER FOR FIRE. WE HAVE RAISED A RED FLAG WARNING FOR ALL OF OUR PA COUNTIES, AS IT APPEARS THE WIND CRITERIA WILL BE MET BY AFTERNOON. PLENTY OF DRY FUELS ALREADY IN PLACE, AND THERE HAVE BEEN ISOLATED BRUSH FIRES REPORTED PREVIOUS 2 DAYS. THE MAIN ENERGY WITH THE ONCOMING STORM SYSTEM WILL BE WELL NORTH OF OUR REGION, INTO CANADA. THERE IS A SLIGHT CHANCE FOR A THUNDERSTORM OVER WESTERN AREAS OF OUR AREA LATE THIS AFTERNOON, BUT BELIEVE THIS THREAT WILL BE FINISHED ONCE THE SUN SETS AND INSTABILITY SLACKENS. WITH DRY AIR PROGGED TO RETURN BEHIND THE COLD FRONT, WE WENT WITH MAINLY SUNNY SKIES ON TUESDAY AND ALSO BOOSTED TEMPS A FEW DEGREES. THE NEXT CHC FOR SUSTAINED PRECIP APPEARS TO BE WEDNESDAY WHEN A DISTURBANCE TRACKS ALONG A WARM FRONT EXPECTED TO BE OVER THE OHIO VALLEY AND NORTHEAST PA. DJP LONG TERM /WEDNESDAY THROUGH SUNDAY/... FOLLOWED HPC GUIDANCE. OVERRUNNING RAIN MOVING IN ON WEDNESDAY AND STAYING ESPECIALLY IN PA UNTIL SFC LOW MOVES TO THE COAST FRIDAY. ON SATURDAY TO SUNDAY A WEAK FRONT MOVES THROUGH ON NW FLOW WITH SHOWERS. FOR THE EXTENDED WET AND COOLER THAN NORMAL TEMPERATURES. WITH THE LONG PERIOD OF RAIN AT THE START OF THE EXTENDED MOST LOCATIONS COULD GET 1 TO 2 INCHES. NE PA COULD GET MORE AND WILL NEED TO BE WATCHED SINCE 2 INCHES STARTS GETTING AROUND FLASH FLOOD AND FLOOD GUIDANCE. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...NONE. PA...&& $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 952 AM EDT MON APR 23 2007 .SHORT TERM /REST OF TODAY/... ONLY MINOR CHANGES HAVE BEEN MADE TO THE PUBLIC FORECAST PACKAGE FOR THE REMAINDER OF TODAY. MAX TEMPERATURES ARE STILL TARGETED AT LOWER TO MID 80S. SURFACE WINDS AND WIND GUSTS HAVE BEEN INCREASED SOMEWHAT FOR THIS AFTERNOON WITH POSSIBLE GUSTS TO AROUND 30 MPH. CONTINUED DRY UNDER SUNNY SKIES. -RFG && FIRE WEATHER... A RED FLAG WARNING HAS REPLACE THE FIRE WEATHER WATCH FOR TODAY. SOUTHWESTERLY WINDS ARE OBSERVED AT 30 KNOTS JUST ABOVE THE SURFACE BASED MORNING INVERSION WITH A BURNOFF TEMPERATURE NEAR 73 THIS MORNING. SOME GUSTS MAY SURFACE TO NEAR 30 MPH ANYTIME AFTER TEMPERATURES REACH MID 70S. MIXING HEIGHTS MAX OUT AROUND 7000 FT WITH SURFACE MAX TEMPERATURES REACHING LOWER TO MID 80S THIS AFTERNOON. LATEST RUC MODEL GUIDANCE SHOWS SOME DEWPOINTS LOWERING INTO THE 30S MAINLY NORTHEAST THIS AFTERNOON...WHICH COMPUTES TO RELATIVE HUMIDITY IN THE 18-23 PERCENT RANGE. -RFG && .PREV DISCUSSION... /ISSUED 314 AM EDT MON APR 23 2007/ SYNOPSIS... HIGH PRESSURE WILL REMAIN OFF THE SOUTHEAST COAST THROUGH LATE TUESDAY.THIS SYSTEM WILL MOVE EAST WEDNESDAY AS A LOW PRESSURE AREA WITH ITS ASSOCIATED COLD FRONT WORKS ITS WAY EAST FROM TEXAS. A COLD FRONT WILL LINGER JUST NORTH OF THE STATE LATE TUESDAY THROUGH LATE WEDNESDAY. A COLD FRONT WILL THEN WORK ITS WAY ACROSS THE STATE THURSDAY THROUGH FRIDAY... WITH HIGH PRESSURE BUILDING BACK OVER THE REGION SATURDAY. SHORT TERM /TODAY THROUGH WEDNESDAY/... AS AN UPPER LEVEL RIDGE MOVES OFF SHORE AND SURFACE HIGH PRESSURE LINGERS OFF THE COAST... WINDS OVER THE AREA WILL BECOME MORE SOUTHWEST AND WEST. WITH LITTLE OR NO CLOUD COVER MAXIMUM RADIATION WILL OCCUR PUSHING THE MERCURY IN THE MID 80S OVER MOST OF THE AREA. MOISTURE WILL INCREASE OVER THE AREA TONIGHT THROUGH WEDNESDAY AS SOUTHWEST FLOW PERSISTS OVER THE REGION. AT THE PRESENT TIME IT LOOKS LIKE THE BOUNDARY ASSOCIATED WITH THE APPROACHING LOW WILL REMAIN FAR ENOUGH NORTH NOT TO THREATEN US WITH MORE THAN AN ISOLATED AFTERNOON SHOWER OR THUNDERSTORM. HIGHS IN THE LOW TO MID 80S TUESDAY AND WEDNESDAY. LOWS IN THE MID 50S TO LOWER 60S. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... MAINLY DRY CONDITIONS WILL PREVAIL THROUGH EARLY THURSDAY. AS THE COLD FRONT APPROACHES AND MOVES ACROSS THE AREA THURSDAY AFTERNOON THROUGH FRIDAY AFTERNOON... THE CHANCE FOR RAIN WILL OVER SPREAD THE REGION. A BOUNDARY WILL LINGER OVER THE EASTERN PORTION OF THE CWA FRIDAY NIGHT... THEN BE PUSHED SOUTHEAST AS HIGH PRESSURE BUILDS IN THE AREA FROM THE NORTH AND NORTHEAST SATURDAY AND SUNDAY. AVIATION /06Z-06Z/... SOUTHWEST WINDS WILL BEGIN TO INCREASE TODAY AS HIGH PRESSURE OFF THE COAST OF THE CAROLINAS REMAINS FIRMLY IN PLACE. GUSTS APPROACHING 25 MPH ARE POSSIBLE BY MID AFTERNOON. OTHERWISE CEILINGS AND VISIBILITIES UNLIMITED. .RAH WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM EDT THIS EVENING FOR NCZ007>011- 021>028-038>043-073>078-083>086-088-089. && $$ SHORT TERM...RFG FIRE WEATHER...RFG nc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PADUCAH KY 1134 AM CDT MON APR 23 2007 .UPDATE... MAIN CHANGE FOR FIRST PERIOD OF FORECAST IS CLOUD COVER AND WEATHER...WITH MODERATE ADJUSTMENTS TEMPERATURE/DEWPOINT AND WIND GUSTS. THE 40KM RUC/NAM SEEM TO HAVE THE BEST HANDLE ON LOW LEVEL QG FORCING UP TO 850 MB...ALONG AND AHEAD OF SURFACE COLD FRONT BISECTING MO FROM SW TO NEWD NEAR KSTL AT 16Z. A NARROW PLUME OF HIGH THETA-E AIR...IMPLIED THROUGH THE 925-700 MB MANDATORY LEVEL UA CHARTS AND GOES SOUNDER IMAGERY PRECIPITABLE WATER VALUES OF 1.29 INCHES...STRETCHES FROM MURRAY KY TO OWENSBORO KY THIS AM. INSTABILITY IN THIS AXIS WILL BE MARGINAL...BUT ENOUGH SURFACE BASED CAPE /400-500 J/KG IN THE 15Z RUN OF THE 40 KM RUC/ EXISTS THIS AFTERNOON OVER WRN KY AND SWRN IN TO WARRANT A CONTINUED MENTION OF A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. THERE SEEMS TO BE SOME RELAXATION OF THE FRONTAL BOUNDARY FORCING THROUGH EARLY AFTERNOON...BUT IT REGAINS ITS STRENGTH BY MID AFTEROON DURING PEAK HEATING AT THE SURFACE. IN THE GRID FORECAST...ATTEMPTED TO SHOW SOME INCREASE IN RAIN CHANCES OVER SERN IL AT THAT TIME. GOOD MIXING WILL CONTINUE DURING THE AFTERNOON THROUGH 850 MB. GIVEN THE 40KT PLUS WINDS EVIDENT AT THE 12Z UA CHARTS AND PROGGED IN THE RUC SOUNDING THIS AFTERNOON...I CANNOT RULE OUT LOCAL WIND GUSTS NEAR 30 MPH. A MANUAL EDIT IN THE TEXT FORECAST TO ACCOUNT FOR THE LOCAL WIND GUSTS THIS AFTERNOON. THE NAM/RUC OVER-COMPENSATED WITH SLIGHTLY HIGHER SURFACE DEWPOINTS THAT OBSERVED THIS MORNING. I ADJUSTED THE AFTERNOON DEWPOINTS DOWN SLIGHTLY...BUT IN LINE WITH THE NAM/RUC ORIENTATION OF THE FRONT AND AFOREMENTIONED THETA-E AXIS. && .PREV DISCUSSION... /ISSUED 355 AM CDT MON APR 23 2007/ DISCUSSION... MAIN CONCERN FOR THIS FORECAST CONTINUES TO BE POPS THROUGHOUT. AN EXAMINATION OF THE 00Z NAM AND GFS SOUNDINGS SHOWS A CONSENSUS FOR A MID-LEVEL CAP JUST ABOVE 700MB OVER THE ENTIRE AREA TODAY...BUT MOST NOTABLY IN THE NORTH. IN ADDITION THE WEAKENING FRONT WILL NOT REACH THE AREA UNTIL THIS EVENING. SO DESPITE INCREASING LOW LEVEL MOISTURE...WHICH IS OVERDONE IN THE GFS...THE LACK OF A FOCUS AND THE PRESENCE OF A CAP WILL PREVENT DEEP CONVECTION TODAY. THERE IS SOME POTENTIAL THAT SHALLOW CONVECTION MAY DEVELOP AND BE JUST DEEP ENOUGH TO GENERATE THUNDER...SO WILL KEEP JUST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AREAWIDE TODAY. HOWEVER...WOULD NOT BE SURPRISED TO SEE NO DEVELOPMENT AT ALL. FOR TONIGHT...THE WEAKENING SURFACE BOUNDARY WILL TRY TO WORK INTO NORTHERN ZONES IN THE EVENING...AND THE CAP SHOULD WEAKEN AS SHORT WAVE RIDGING PASSES EAST OF THE AREA. WITH A LOW-LEVEL FOCUS...ALBEIT WEAK...LITTLE CAP AND EVER INCREASING MOISTURE...WILL KEEP 20 POPS WEST AND 30 POPS EAST...WHERE CONVERGENCE AND MOISTURE ARE MOST LIKELY TO INTERACT. FOR TUESDAY...THE GFS CONTINUES TO GENERATE WIDESPREAD QPF OVER THE AREA MAINLY IN THE AFTERNOON...BUT THE NAM IS NOT NEARLY AS WET. HOWEVER...THE SOUNDINGS FROM BOTH MODELS SHOW THAT THE ENTIRE AREA SHOULD BE UNCAPPED...ALLOWING FOR NUMEROUS DIURNAL SHOWERS AND THUNDERSTORMS TO DEVELOP THROUGHOUT THE REGION. HOWEVER...WITH VERY WEAK WIND FIELDS...AND LONG...SKINNY CAPE...FEEL THAT ONLY SEVERE ISSUE ON TUESDAY WILL BE HEAVY RAIN...WITH PRECIPITABLE WATERS IN THE 1.25 TO 1.5 INCH RANGE. WILL HAVE 60 POPS ALL BUT THE EVV AREA...WHERE 50S SHOULD DO FINE. TUESDAY NIGHT HAS CONSIDERABLE BUST POTENTIAL. WITH THE WARM FRONT ESTABLISHED NORTH OF THE AREA IN THE NAM AND GFS...AND THE SURFACE LOW WELL WEST OF THE AREA...THERE WILL BE NO FOCUS FOR CONVECTIVE DEVELOP TUESDAY NIGHT. HOWEVER...THERE IS NO MAJOR CAP TO OVERCOME...IF SOME FORCING CAN LIFT THE LOW-LEVEL PARCELS. THE GFS IS AGRESSIVE IN PUSHING CONSIDERABLE QPF INTO AT LEAST THE WESTERN HALF OF THE AREA BY 12Z...BUT THE NAM KEEPS THE AREA MAINLY DRY. CONSENSUS POPS ARE LIKELY TO CATEGORICAL...SO THERE IS NO WAY TO AVOID LIKELY POPS...ESPECIALLY WHEN YOU ARE SURROUNDED BY HIGH POPS. WILL HAVE A 70 IN SOUTHEAST MISSOURI...A 50 NEAR KHOP AND 60S ELSEWHERE. AM VERY CONCERNED THE THE NAM WILL BE RIGHT...BUT HPC IS GOING MORE TOWARD THE WET GFS SOLUTION. WIND FIELDS WILL IMPROVE CONSIDERABLY TUESDAY NIGHT...SO ORGANIZED CONVECTION WILL BE POSSIBLE WITH HELICITY VALUES SUPPORTING THE POTENTIAL FOR SUPERCELLS. SO THE SLIGHT RISK FROM SPC SEEMS REASONABLE...IF THE CONVECTION GETS HERE. WEDNESDAY...THE WARM FRONT TO OUR NORTH WILL SAG INTO THE REGION AS THE UPPER LOW BEGINS TO TURN MORE EASTERLY RIGHT TOWARD THE AREA...WITH SURFACE LOW APPROACHING SOUTHEAST MISSOURI BY THE END OF THE DAY. THE UKMET SUPPORTS THIS SCENARIO...BUT MAYBE JUST A BIT SLOWER THAN THE GFS. WEDNESDAY WILL BE THE WETTEST DAY...SO WENT WITH CATEGORICALS IN THE NORTH AND WEST...WITH HIGH LIKELIES OVER WEST KENTUCKY. WIND FIELDS WILL CONTINUE TO BE STRONG...SO THE SLIGHT RISK OF SEVERE LOOKS FINE. HEAVY RAINFALL AND FLOODING PROBLEMS WILL ALSO BE A PROBLEM. WILL KEEP LIKELY POPS GOING FOR WEDNESDAY NIGHT...AS THE BOUNDARIES FINALLY SLIP SOUTHEAST OF THE AREA...AND THE UPPER SYSTEM APPROACHES FROM THE WEST. THURSDAY WILL HAVE 50 POPS EVERYWHERE...AND PROBABLY SHOULD HAVE LIKELIES AGAIN...AS THE UPPER SYSTEM SLOWS TO A CRAWL OVER THE AREA. LI/S AND SI/S BOTH STILL NEGATIVE OVER THE ENTIRE AREA WEDNESDAY NIGHT AND THURSDAY...SO KEPT FULL THUNDER MENTION BOTH PERIODS. KEPT THE SLIGHT CHANCE FOR SHOWERS IN THE EAST ON THURSDAY NIGHT AS THE SYSTEM FINALLY PUSHES EAST OF THE AREA. THE 00Z GFS DOES NOT SUPPORT THE POPS OVER THE WEEKEND...BUT WILL LET THE DAY SHIFT SORT THAT OUT. AS FOR SHORT TERM TEMPERATURES...WENT CLOSE TO THE WARMER MET FOR HIGHS TODAY...THEN STAYED CLOSE TO THE MAV/MET CONSENSUS FOR TONIGHT AND TUESDAY. TUESDAY NIGHT AND WEDNESDAY GENERALLY WENT JUST A BIT ABOVE THE CONSENSUS. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ SMITH/PS ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 415 PM EDT MON APR 23 2007 .SHORT TERM (TONIGHT AND TUE)... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHORTWAVE THAT BROUGHT RAIN TO MUCH OF THE AREA LAST NIGHT/THIS MORNING MOVING E OVER LAKE HURON. SYSTEM IS ACCELERATING IN RESPONSE TO STRONG SHORTWAVE ROTATING SE ACROSS SRN HUDSON BAY/NRN ONTARIO. ANOTHER WEAKER SHORTWAVE EXTENDS FROM JUST S OF JAMES BAY TOWARD LAKE SUPERIOR. TO THE W...A SHORTWAVE HAS DROPPED OUT OF THE MAIN BAND OF WESTERLIES AND HAS CLOSED OFF OVER THE SW STATES. THIS WILL BE THE NEXT FEATURE TO WATCH AS IT HEADS E ACROSS THE CONUS OVER THE NEXT SEVERAL DAYS. CLOSER TO HOME...STRATOCU HAS BEEN VERY SLOWLY BREAKING UP OVER THE FCST AREA DURING THE LAST FEW HRS. MESOHIGH TRYING TO DEVELOP OVER FAR WRN LAKE SUPERIOR AND THE RESULTING SUBSIDENCE/DIFFLUENT LOW-LEVEL FLOW HAS KEPT SKIES MAINLY CLR OVER WRN LAKE SUPERIOR. ONE LAST BATCH OF MOISTURE/STRATOCU IS DROPPING ACROSS THE AREA NOW IN ASSOCIATION WITH THE SHORTWAVE EXTENDING FROM JAMES BAY TOWARD LAKE SUPERIOR. A QUIET PERIOD OF WX IS EXPECTED TONIGHT/TUE AND THRU MIDWEEK. SFC HIGH PRES RIDGE NOSING INTO THE PLAINS FROM CANADA NOW WILL DRIFT E TO THE GREAT LAKES TUE...SETTING THE STAGE FOR CLASSIC SPRING MESOHIGH DEVELOPMENT OVER LAKE SUPERIOR AND OVER NRN LAKE MICHIGAN TUE AFTN. SO...WINDS WILL DIMINISH TO LIGHT TONIGHT...AND THEN LAKE BREEZES WILL TAKE OVER ACROSS THE BOARD TUE. NAM AND ESPECIALLY RUC13 HAVE A NICE DEPICTION OF THIS SCENARIO. LINGERING STRATOCU SHOULD QUICKLY DISSIPATE EARLY THIS EVENING... LEAVING BEHIND CLR/MOSTLY CLR SKIES OVERNIGHT THRU TUE. DRYNESS OF AIRMASS SUGGESTS LITTLE IN THE WAY OF CU DEVELOPMENT TUE. SO AFTER STRATOCU DISSIPATE THIS EVENING...ONLY CLOUD COVER WILL BE SOME CI AT TIMES. AS FOR TEMPS...HAVE GONE CLOSE TO MOS GUIDANCE TONIGHT RATHER THAN UNDERCUTTING SINCE RADIATIONAL COOLING CONDITIONS WILL NOT BE IDEAL (COLUMN IS NOT ESPECIALLY DRY). DRY LOW-LEVEL AIRMASS SHOULD ALLOW FOR DEEP MIXING UPWARDS OF 800MB TUE AFTN. PER NAM/GFS FCST SOUNDINGS...THIS SHOULD YIELD HIGHS IN THE 55-60F RANGE AWAY FROM THE MODERATING INFLUENCE OF THE GREAT LAKES. && .LONG TERM...(TUESDAY NIGHT THROUGH MON) ABBREVIATED DUE TO EQUIPMENT MALFUNCTION TUE NIGHT THROUGH WED NIGHT...HIGH PRES WILL PREVAIL WITH MID/UPPER LEVEL CONFLUENT FLOW. MIN TEMPS GENERALLY AOB GUIDANCE WITH GOOD RADIATONAL COOLING CONDITIONS. THU INTO FRI...12Z GFS SHOWED A SUBSTANTIAL CHANGE FROM THE 00Z/06Z RUNS AND BRINGS SRN STREAM MID LEVLE AND SFC LOW FROM THE MID MS VALLEY FARTHER TO THE NORTH. BEST ISENTROPIC LIFT AND MID LEVEL FGEN AHEAD OF THE SYSTEM SHOULD REAMIN TO THE SOUTH THU BUT MAY BRING INCREASING CLOUDS TO THE SOUTH. EVEN THOUGH THE NORTHWARD SHIFT WAS SUPPORTED BY THE CANADIAN AND UKMET...NO PCPN WAS ADDED OVER THE SE HLF OF THE CWA YET FOR THU NIGHT BUT MAY BE NEEDED IF THE RECENT MDL TREND HOLDS UP. FRI NIGHT THROUGH MON...MDLS WERE IN GENERAL AGREEMENT WITH THE BUILDING RIDGE OVER THE ROCKIES AND PLAINS RESULTING IN WNW FLOW THROUGH THE WRN GREAT LAKES. CONFIDENCE IS LOW HOWEVER WITH TIMING/DETAILS OF ANY SHRTWVS MOVING THROUGH THE UPPER GREAT LAKES THAT MAY SUPPORT PCPN. LIMITED MDLS CONSENSUS FOR SHRTWV MOVING THROUG NRN ONTARIO AND A COLD FRONT INTO UPPER MI COULD BRING -SHRA CHANCES SUN. MOISTURE WITH THIS SYSTEM WOULD BE LIMITED WHICH WOULD BE UNFAVORABLE FOR TSRA AND WOULD RESULT IN ONLY LIGHT PCPN AMOUNTS IF ANY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON (SHORT TERM) JLB(LONG TERM) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 413 PM EDT MON APR 23 2007 .SHORT TERM...TONIGHT AND TOMORROW SUNNY SKIES WERE EXPERIENCED BY MOST THIS MORNING AS A DRY SLOT FOLLOWED THE INITIAL ACTIVITY THAT MOVED THROUGH AT DAYBREAK. THIS ALLOWED TEMPERATURES TO CLIMB INTO THE MID 70S ACROSS MOST OF THE CWA BEFORE CLOUDS AGAIN DEVELOPED OVERHEAD. THIS FAST CLIMB IN TEMPERATURES COUPLED WITH DEEP SOUTHWEST FLOW ALLOWED FOR AN OPTIMUM MIXING ENVIRONMENT ALLOWING WINDS TO GUST IN THE MID 40 TO UPPER 40S MPH. INSTABILITY EVOLVED AS EXPECTED WITH UPWARDS TO 500 JOULES/KG LAPS/SURFACE BASED AND RUC/MOST UNSTABLE CAPES ACROSS FAR SOUTHEASTERN LOWER MICHIGAN. THIS INSTABILITY RESIDED BETWEEN PREFRONTAL SURFACE TROUGH AND SUBSEQUENT COLD FRONT. MAIN SYNOPTIC COLD FRONT IS CURRENTLY SLIDING THROUGH SOUTHERN WISCONSIN AND WESTERN MICHIGAN...WITH AN OUTSTANDING FINE LINE EARLIER ON MKX 88D. CONVECTION HAS BEEN WEAK TO NULL AND IS ATTRIBUTED TO LACK OF MOISTURE/INSTABILITY AND THE WASHED OUT BOUNDARY TRYING TO PROVIDE INITIATION. THE RATHER DEVELOPED WAVE RESPONSIBLE FOR TODAY/S SENSIBLE WEATHER WAS TRACKING ACROSS NORTHERN LAKE HURON AND CONTINUES TO RAPIDLY TRACK NORTHEASTWARD. WIND ADVISORY WILL EXPIRE AT PACKAGE ISSUANCE. THE HIGHER WIND ACTIVITY WAS ASSOCIATED WITH EVAPORATIVE PROCESSES FROM THE PASSING SHOWERS. WITH THE WANE IN SHOWER ACTIVITY AS WELL AS THE EASTWARD TRANSLATION TO THE LOW LEVEL JET EXPECTING A QUICK DYING OF THE WINDS. DIRECTIONS WILL VEER AT FIRST WESTERLY AND THEN NORTHWESTERLY INTO THE OVERNIGHT. EXPECTING NO FURTHER DEVELOPMENT IN REGARDS TO PRECIPITATION TONIGHT. THERE IS A SMALL CHANCE MORE SHOWER ACTIVITY COULD DEVELOP ALONG THE SYNOPTIC COLD FRONT BUT THAT HAS LOOKED MINIMAL AT BEST THE PAST HOUR. IN ADDITION STRONG DRYING ASSOCIATED WITH SUBSIDENCE BEHIND DEPARTING SHORTWAVE IS PUSHING INTO CENTRAL LOWER MICHIGAN ATTM....FURTHER INHIBITING ANY UPDRAFT GROWTH AT THE MID LEVELS. SHORTWAVE AND SURFACE RIDGING WILL CONTROL TOMORROW BRINGING A QUIET PLEASANT DAY. A DRY ATMOSPHERE SHOULD PROVIDE FOR CLEAR SKIES ALLOWING APRIL SUN TO WARM THE AREA INTO THE LOW TO MID 60S. WINDS ARE EXPECTED TO BE LIGHT NORTHERLY. && .LONG TERM...TUESDAY NIGHT THROUGH MONDAY THROUGH THURSDAY... NORTHERN STREAM 500 MB SHORTWAVE TROUGH MOVING EAST SOUTHEAST ACROSS NORTHERN LAKES REGION TUESDAY NIGHT AND WEDNESDAY...A BIT OF SHORTWAVE RIDGING OVERHEAD WEDNESDAY NIGHT...THEN A LOW FROM THE CENTRAL PLAINS APPROACHES THURSDAY. AT THE SURFACE...MODEL CONSENSUS SHOWS RIDGE GETTING NUDGED TEMPORARILY NORTHEAST TUESDAY NIGHT INTO WEDNESDAY AS AN OVERRUNNING FRONT BECOMES WELL ESTABLISHED ACROSS THE OHIO VALLEY...WITH THE HIGH PRESSURE SOMEWHAT GAINING CONTROL AGAIN LATE WEDNESDAY/WEDNESDAY NIGHT BEFORE AGAIN RETREATING THURSDAY. 850 TO 500 MB MOISTURE ON THE INCREASE TUESDAY NIGHT BEFORE GETTING SUPPRESSED SOUTH LATE WEDNESDAY AND WEDNESDAY NIGHT AND WORKING BACK TO THE NORTH THURSDAY. 925 MB MOISTURE SHOWING SIMILAR TRENDS. AS FOR LOW TO MID LEVEL OMEGA ASCENT...MODEL CONSENSUS FAVORS INCREASING ASCENT BY LATE TUESDAY NIGHT INTO WEDNESDAY ESPECIALLY SOUTH...SOME INCREASE AGAIN THURSDAY. 850 TO 500 MB QVECTOR CONVERGENCE FAIRLY GOOD BY LATE TUESDAY NIGHT...SLIGHT SOUTH WEDNESDAY AND WEDNESDAY NIGHT. LOW LEVEL WIND CONVERGENCE OCCASIONALLY SLIGHT AT BEST UNTIL BECOMING MORE DEFINED THURSDAY...850 MB CONVERGENCE ALSO MOST PREVALENT ON THURSDAY. 290K ISENTROPIC ASCENT OF A FEW UBAR/SEC...WITH SUITABLY LOW CONDENSATION PRESSURE DEFICITS...SEEN BY BOTH NAM AND GFS LATE TUESDAY NIGHT INTO WEDNESDAY BEFORE THEN BACKING OFF UNTIL THURSDAY. STILL SEE CONSIDERABLE UNCERTAINTY AS TO NORTHERN EXTENT OF PRECIPITATION SHIELD LATE TUESDAY NIGHT AND WEDNESDAY...AS NORTHERN STREAM SHORTWAVE TROUGH COULD CONCEIVABLY SUPPRESS RAINFALL TO EVEN THE OHIO BORDER. WILL...HOWEVER...PLAY THE ODDS AND STRIATE POPS TUESDAY NIGHT/WEDNESDAY FROM SLIGHT CHANCE FAR NORTH TO LIKELY SOUTH...THEN BACK OFF COVERAGE AND POPS WEDNESDAY NIGHT AND GO CHANCE POPS THROUGHOUT AGAIN THURSDAY. AFTER THURSDAY... WEAKENING EJECTING SOUTHWESTERN 500 MB LOW/TROUGH MOVING THROUGH THE AREA THURSDAY NIGHT AS PER MODEL CONSENSUS INCLUDING GFS ENSEMBLE MEANS...WITH A NORTHERN STREAM TROUGH INTO MAINLY THE NORTHERN LAKES REGION FRIDAY. THIS TO BE FOLLOWED BY MORE IN WAY OF OCCASIONAL IMPULSES RIDING OVER THE BROAD PLAINS RIDGE INTO LAKES REGION...ESPECIALLY ABOUT SUNDAY. DGEX/GFS DIG ENERGY DOWN ACROSS THE EASTERN LAKES REGION MONDAY. AT THE SURFACE...RIDGE DRAPED ACROSS THE GREAT LAKES THURSDAY NIGHT INTO FRIDAY AS LOW PRESSURE PASSES SOUTH OF GREAT LAKES...BUT THERE EXISTS LOTS OF MODEL SOLUTION SPREAD AS TO TRACK OF THIS LOW AND THEREFORE HOW VIGOROUSLY MOISTURE AND SHOWERS WILL ADVANCE NORTH. WILL COVER BY MENTIONING CHANCE OF SHOWERS THURSDAY NIGHT AND FRIDAY. THEREAFTER...A COLD FRONT EXPECTED TO PASS THROUGH BY MONDAY AS PER MODEL CONSENSUS...SO AM CONTINUING SHOWERS/THUNDER MENTION FOR SUNDAY AND SUNDAY NIGHT. && .PREV DISCUSSION...ISSUED 206 PM EDT MON APR 23 2007 AVIATION... MAIN CONCERN FOR THE TAF PERIOD WILL BE WINDS AND PRECIPITATION CHANCES INTO THIS EVENING. WINDS HAVE BEEN GUSTING INTO THE LOWER 40S ACROSS THE ENTIRE CWA THIS EARLY AFTERNOON. GREATER MIXING OF STRONGER WINDS ALOFT HAS OCCURRED UNDER THE SHOWER/UPDRAFT ACTIVITY. ISOLATED GUSTS OF UP TO 50 MPH WILL STILL BE POSSIBLE EARLY THIS AFTERNOON. WIND DIRECTION WILL VEER MORE WESTERLY THIS AFTERNOON BEFORE COLD FRONT SWEEPS THROUGH BACKING FURTHER TO THE NORTHWEST AFTER 00UTC. THUS FAR...SHOWER ACTIVITY HAS REMAIN LIMITED WITH RAINFALL RESTRICTED TO THE NORTH IN SAGINAW AND BAD AX. DEEPER MOISTURE RESIDES CLOSER TO THE WAVE ACROSS NORTHERN LOWER PENINSULA. LATEST LAPS DATA HAS A FEW HUNDRED JOULES/KG ACROSS SOUTHEASTERN MICHIGAN. EXPECTING A QUICK END TO THE SHOWER AND SCATTERED THUNDERSTORM ACTIVITY FEEDING OFF THAT LIMITED ENERGY LATER THIS AFTERNOON. PREFRONTAL TROUGH PROVIDING THE FOCUS WILL SLIDE ON TO THE EAST. AN ADDITIONAL LIFTING MECHANISM FOR PRECIPITATION MAY BE THE COLD FRONT WHICH WILL SLIDE THROUGH LATER THIS EVENING. HOWEVER...NOT EXPECTING MUCH IN THE WAY OF RECOVERY/DEVELOPMENT WITH EVEN REDUCED INSTABILITY IN THAT AREA. IN ADDITION TO VEERING NORTHWESTERLY...WINDS WILL ALSO SLACKEN CONSIDERABLY BEHIND THE COLD FRONTAL PASSAGE. TO CARRY OUT THE REST OF THE FORECAST PERIOD..EXPECTING PREVAILING VFR CONDITIONS AS GUIDANCE DRY ADVECTS BEHIND THE DEPARTING WAVE. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...SMALL CRAFT ADVISORY...UNTIL 8 PM MONDAY. MI WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY...UNTIL 8 PM MONDAY. && $$ SHORT TERM...CB LONG TERM....DWD AVIATION...CB YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 254 PM MDT MON APR 23 2007 .DISCUSSION... 19Z SURFACE ANLAYSIS SHOWS A 1004MB LOW PRES CENTER OVER SE CO WITH A LEE TROUGH EXTENDING SW INTO THE E PLAINS. LATEST WATER VAPOR LOOP SHOWS A PLUME OF UPPER LEVEL MOISTURE EJECTING NE ACROSS TX AHEAD OF AN UPPER LOW SPINNING EAST ACROSS AZ/UT BORDER. 400-250MB AIRCRAFT WIND PLOT SHOWS A 100-120 KNOT JET ROUNDING THE BASE OF THE TROUGH THROUGH SOCA ACROSS AZ AND INTO NW CORNER OF NM. WINDS HAVE ALSO BEEN INCREASING STEADILY ACROSS NM THIS AFTERNOON. AS THE UPPER JET TRANSLATES EAST EXPECT WINDS TO CONTINUE TO INCREASE WITHIN THE WIND ADVISORY AND WARNING AREAS THROUGH THE EVENING. THE AXIS OF STRONGEST WINDS WILL LIKLEY PASS OVER THE SOUTHERN MTNS LATE THIS EVENING. 18Z RUC ANALYSIS INDICATES A SWATH OF 40-50 KNOT 700MB WINDS WITH SUPPORT FROM 70-80 KNOT 500MB JET CROSSING THE SOUTHEAST PLAINS THROUGH TUES MORNING. 12Z NAM/GFS/UKMET...15Z SREF/12Z MREF IN GOOD AGREEMENT WITH THE 500MB PATTERN THROUGH WED MORNING. 560DM H5 LOW AND ASSOCIATED -4C COLD POOL WILL BE CENTERED OVER THE FOUR CORNERS BY 06Z TUE THEN OVER NE NM BY 12Z TUE. SHOWERS AND STORMS WILL CONTINUE TO MOVE EAST AHEAD OF THE UPPER LOW WITH MODEST UPPER LEVEL DIFFLUENCE AND MID LEVEL INSTABILITY. RAIN WILL CHANGE TO SNOW IN THE HIGHER ELEVATIONS LATE THIS EVENING AS THE COLD POOL MOVES EAST THROUGH THE NORTHERN MTNS. MOIST SOUTHWEST FLOW HAS TENDED TO VEER MORE TO THE WEST AND NORTHWEST DUE TO SLIGHTLY MORE NORTHERLY TRACK WITH THE UPPER LOW THROUGH TUE MORNING...SO THINKING SNOW ACCUMS WILL AVERAGE 1-3 INCHES IN THE HIGHER TERRAIN. HPC SNOW ACCUM GRAPHICS STILL INDICATING 2-4 INCHES IN THE NORTHERN MTNS MAINLY FROM TUE MORNING THROUGH EARLY TUE AFTERNOON. WINDS WILL BE UP ONCE AGAIN TUE WITH ADVISORIES LIKELY IN THE EAST CENTRAL PLAINS ALONG AND SOUTH OF INTERSTATE 40. FIRE WEATHER WATCH WILL ACCOMPANY THE WINDY CONDITIONS AS MIN RH VALUES HOVER BTWN 10 AND 15 PERCENT. CONDITIONS WILL IMPROVE ACROSS MUCH OF THE CWA BY WEDNESDAY WITH STRONGEST WINDS CONFINED MAINLY TO THE FAR EASTERN PLAINS. TEMPS WILL BE COOL IN THE NORTHEAST WED AS A SECONDARY COLD FRONT MOVES SOUTH DOWN THE FAR E PLAINS. NORTHWEST FLOW WILL DEVELOP ACROSS THE REGION BEHIND THE EXITING UPPER LOW THROUGH THURS. A WEAK DISTURBANCE WILL ATTEMPT TO SLIDE SE OVER THE NE PLAINS FRIDAY WITH A COLD FRONT COOLING TEMPS TO NEAR NORMAL. A RIDGE OF HIGH PRESSURE WILL THEN DEVELOP OVER THE SW CONUS BY THE END OF THE WEEK ALLOWING TEMPS TO WARM 5-10F ABOVE NORMAL FOR THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 39 63 35 69 / 40 20 0 0 GALLUP.......................... 33 61 27 68 / 30 20 0 0 GRANTS.......................... 34 61 30 69 / 30 20 0 0 GLENWOOD........................ 39 71 40 78 / 10 5 0 0 CHAMA........................... 28 46 24 58 / 60 60 10 5 LOS ALAMOS...................... 34 56 32 63 / 30 30 0 0 RED RIVER....................... 26 39 24 48 / 50 60 30 5 TAOS............................ 37 52 30 61 / 40 40 10 5 SANTA FE........................ 35 56 32 64 / 30 30 0 0 SANTA FE AIRPORT................ 38 59 35 66 / 20 20 0 0 ESPANOLA........................ 41 61 37 70 / 30 30 0 0 ALBUQUERQUE HEIGHTS............. 45 65 43 71 / 10 10 0 0 ALBUQUERQUE VALLEY.............. 42 67 41 72 / 10 10 0 0 ALBUQUERQUE FOOTHILLS........... 39 62 41 70 / 20 20 0 0 ALBUQUERQUE WEST MESA........... 43 64 42 72 / 20 10 0 0 SOCORRO......................... 48 70 44 75 / 5 10 0 0 SANDIA PARK/CEDAR CREST......... 34 59 34 65 / 30 20 0 0 MORIARTY/ESTANCIA............... 40 61 37 67 / 5 10 5 0 CARRIZOZO....................... 47 68 43 70 / 0 5 0 0 RUIDOSO......................... 44 60 39 64 / 0 5 0 0 RATON........................... 37 53 35 59 / 20 40 30 20 LAS VEGAS....................... 39 59 33 63 / 10 20 10 5 ROY............................. 42 59 38 59 / 5 10 20 5 CLAYTON......................... 45 59 37 57 / 5 30 30 20 SANTA ROSA...................... 48 69 44 70 / 5 10 10 5 TUCUMCARI....................... 49 68 43 66 / 5 10 10 5 FORT SUMNER..................... 48 71 45 71 / 0 5 10 5 CLOVIS.......................... 48 70 42 69 / 5 5 10 5 PORTALES........................ 48 72 43 70 / 5 5 10 5 ROSWELL......................... 52 79 47 76 / 0 5 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ106>108. WIND ADVISORY UNTIL 10 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ005-008>012-014-015-018-019. FIRE WEATHER WATCH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES... NMZ108. HIGH WIND WARNING UNTIL 6 AM MDT TUESDAY FOR THE FOLLOWING ZONES... NMZ016-017-026. && $$ GUYER nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 204 PM EDT MON APR 23 2007 .AVIATION /18Z-18Z/... A COLD FRONT WILL CROSS THE AREA BETWEEN 00Z-06Z, BUT CONDITIONS ARE EXPECTED TO REMAIN VFR THROUGH THE PERIOD. THROUGH EARLY EVENING SCT/BKN MID/HIGH LEVEL CLOUDS WILL GRADUALLY INCREASE. SOUTHWEST WINDS WILL CONTINUE UNTIL SUNSET AT 10-15 KNOTS WITH GUSTS TO 25-30 KNOTS. WITH FRONTAL PASSAGE INCLUDED A TEMPO PERIOD BTW 23Z-04Z FOR KRME/KSYR AND BTW 01Z-04Z FOR KELM/KITH/KBGM. LEFT KAVP DRY FOR NOW AS BETTER MOISTURE ACROSS NRN AREAS. BEHIND FRONT WINDS WILL SHIFT TO THE NORTHWEST BTW 04Z-07Z WITH CIGS AROUND 4K FT. BY 13Z, CLOUDS WILL SCATTERED OUT AT 4-5K FT WITH NORTHWEST WINDS AROUND 10 KNOTS. RRM && .PREV DISCUSSION... /ISSUED 1123 AM EDT MON APR 23 2007/ SHORT TERM /REST OF TODAY/... BUSY DAY WITH FIRE WEATHER ISSUES. 5 SPOT FORECASTS FOR PRESCRIBED BURNS SO FAR. RED FLAG WARNING FOR PA DUE TO LOWER WIND CRITERIA. SIMILAR CONDITIONS IN NY BUT WIND CRITERIA IS 25 MPH. UPDATE TO BUMP TEMPS UP A FEW DEGREES. TEMPS HAVE RISEN QUICKLY INTO 70S WITH LOW AND MID 80S EXPECTED. REMOVED POPS FROM THE EARLY AFTN BASED ON THE 12Z NAM AND RUC. SHOWERS AND MAYBE A TS LATE AFTN INTO TONIGHT. LIS CLOSE TO ZERO AND MID LEVEL LAPSE RATES GOOD FOR A FEW HOURS RIGHT ALONG THE FRONT. MOISTURE WITH THE FRONT IS LACKING WITH SFC DEWPOINTS RISING ONLY INTO THE U40S. PREV DISCUSSION... /ISSUED 254 AM EDT MON APR 23 2007/ SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... WAVE MOVING THROUGH UPPER MIDWEST WITH ATTENDANT SFC CYCLONE WILL CONTINUE TO OPEN AS IT PULLS NORTHEAST NEXT 24 HOURS. AHEAD OF THE FRONT HIGH PRESSURE IS SLOWLY YIELDING CONTROL OVER THE MID ATLANTIC STATES. THE INCREASED GRADIENT BETWEEN THE COMPETING SYSTEMS WILL STRENGTHEN WINDS ACROSS OUR FORECAST AREA TODAY. WITH THE AIR STILL DRY OVER MUCH OF THE NORTHEAST, AND ONLY A MARGINAL RISE IN DEW POINTS EXPECTED THIS AFTERNOON IN SOUTHERLY FLOW, EXPECT THE WINDS WILL CAUSE A GREATER DANGER FOR FIRE. WE HAVE RAISED A RED FLAG WARNING FOR ALL OF OUR PA COUNTIES, AS IT APPEARS THE WIND CRITERIA WILL BE MET BY AFTERNOON. PLENTY OF DRY FUELS ALREADY IN PLACE, AND THERE HAVE BEEN ISOLATED BRUSH FIRES REPORTED PREVIOUS 2 DAYS. THE MAIN ENERGY WITH THE ONCOMING STORM SYSTEM WILL BE WELL NORTH OF OUR REGION, INTO CANADA. THERE IS A SLIGHT CHANCE FOR A THUNDERSTORM OVER WESTERN AREAS OF OUR AREA LATE THIS AFTERNOON, BUT BELIEVE THIS THREAT WILL BE FINISHED ONCE THE SUN SETS AND INSTABILITY SLACKENS. WITH DRY AIR PROGGED TO RETURN BEHIND THE COLD FRONT, WE WENT WITH MAINLY SUNNY SKIES ON TUESDAY AND ALSO BOOSTED TEMPS A FEW DEGREES. THE NEXT CHC FOR SUSTAINED PRECIP APPEARS TO BE WEDNESDAY WHEN A DISTURBANCE TRACKS ALONG A WARM FRONT EXPECTED TO BE OVER THE OHIO VALLEY AND NORTHEAST PA. DJP LONG TERM /WEDNESDAY THROUGH SUNDAY/... FOLLOWED HPC GUIDANCE. OVERRUNNING RAIN MOVING IN ON WEDNESDAY AND STAYING ESPECIALLY IN PA UNTIL SFC LOW MOVES TO THE COAST FRIDAY. ON SATURDAY TO SUNDAY A WEAK FRONT MOVES THROUGH ON NW FLOW WITH SHOWERS. FOR THE EXTENDED WET AND COOLER THAN NORMAL TEMPERATURES. WITH THE LONG PERIOD OF RAIN AT THE START OF THE EXTENDED MOST LOCATIONS COULD GET 1 TO 2 INCHES. NE PA COULD GET MORE AND WILL NEED TO BE WATCHED SINCE 2 INCHES STARTS GETTING AROUND FLASH FLOOD AND FLOOD GUIDANCE. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...NONE. PA...&& $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 334 PM EDT MON APR 23 2007 .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... PREFRNTL TROF AND ASSOCD -SHRA ACTIVITY HAS JUST ABOUT MOVED OUT OF SE FCST AREA ATTM. ADDL -SHRA BEGINNING TO DVLP AHEAD OF COLD FRONT SITUATED FROM CNTRL LWR MICHIGAN SW INTO NORTH CNTRL INDIANA AND SRN ILLINOIS. SKIES WERE PTLY CLDY AHEAD OF THE FRONT WITH TEMPS WELL INTO THE M/U70S. BNDRY LYR WAS WELL MIXED THIS AFTN WITH GUSTS UP ABV 30MPH FROM THE SW. 12Z MODEL GUIDANCE IN GOOD AGREEMENT IN BRINGING COLD FRONT SLOWLY SE ACRS FCST AREA THIS EVNG. SO FAR THIS AFTN...WARM DRY BULGE OF AIR ABV 800MB HAS KEPT LWR ATMOSPHERE CAPPED. LO LVL MOISTURE CONTINUES TO STREAM NE INTO REGION AHEAD OF THE FRONT WITH DEWPTS APPCH 60 DEG IN SW FCST AREA. COMBINATION OF THIN PLUME OF MOISTURE ADVECTING INTO REGION AND STEEPENING LAPSE RATES AS WEAK MID LVL S/WV PASSES ACRS LWR GRT LKS SHOULD ALLOW FOR SCT CONVECTION TO DVLP OVER NEXT FEW HOURS IMMEDIATELY AHEAD OF FRNTL BNDRY. 12Z GFS/RUC BOTH INDCG MUCAPES APPCH 1000 J/KG DURING THE EVNG HOURS. WHILE BETTER MID/UPR LVL FORCING HAS ALREADY PULLED EAST OF REGION WITH TROF...0-6KM BL SHEAR VALUES WILL HOLD BTWN 30-40KTS THIS EVNG WITH HELICITIES AT NEAR 200 M2/S2. THIS WOULD LEND ITSELF TO PROMOTING SOME STRONGER STORMS FOR LATE AFTN/EVNG HOURS ONCE CAP HAS ERODED...AND POTENTIAL FOR A FEW TO APPCH SVR LIMITS. STORMS SHOULD WEAKEN AFT MIDNIGHT AS FRNTL BNDRY SAGS SLOWLY SOUTH THRU FCST AREA. HAVE MAINTAINED 40-50 POPS FOR ENTIRE FCST AREA INTO THE OVERNIGHT. MODEL GUIDANCE HAS ALSO COME INTO FAIR AGREEMENT ON STALLING FRNTL BNDRY JUST SOUTH OF THE OHIO RIVER ON TUES MRNG AS BNDRY BECOMES PARALLEL TO MEAN UPR FLO AND RUNS INTO STRONG HI PRES RIDGE OVER SE CONUS. HAVE MAINTAINED LO CHANCE POPS ALONG AND SOUTH OF THE OHIO RIVER ON TUES DUE TO CLOSE PROXIMITY OF FRNTL BNDRY. OVERALL FORCING THOUGH IS FAIRLY WEAK. DEEP UPR LO AND ASSOCD SFC LO WILL EJECT INTO WESTERN PLAINS BY TUES EVNG. FRNTL BNDRY WILL BEGIN TO LIFT BACK NORTH INTO FCST AREA TUES NIGHT IN RESPONSE TO MOVEMENT OF PLAINS SYSTEM. THIS WILL SIGNAL THE ONSET OF AN EXTENDED PERIOD OF UNSETTLED WX FOR THE REGION AS THE AFOREMENTIONED FRNTL BNDRY HANGS IN THE OH VLY. SFC WAVE DVLPS ALONG FRNTL BNDRY OVER ILLINOIS AND INDIANA LATE TUES NIGHT AS IT LIFTS NORTH ACRS FCST AREA. ISENT LIFT INCREASES AFT MIDNIGHT AND STRONG LO LVL FORCING ENHANCES ACRS REGION. RAIN SHOULD INCREASE IN COVERAGE AND INTENSITY THRU THE NIGHT WITH POTENTIAL FOR A FEW TSTMS. COULD SEE SOME LOCALLY HEAVY RAIN LATE TUES NIGHT AND PARTICULARLY INTO WED AS SFC WAVE MOVES ACRS THE OH VLY AND PWATS CLIMB TO NEAR 1.5 INCHES. AXIS OF HEAVIEST RAINFALL REMAINS SOMEWHAT UNCERTAIN AT THIS POINT DUE TO THE CONTINUED MOVEMENT OF THE FRNTL BNDRY LOCATION PER EACH SUCCESSIVE RUN OF MODEL DATA. HAVE PLAYED HIGHEST POPS AND CONSEQUENTLY HEAVIEST PCPN ACRS NRN 1/2 FCST AREA AS FEEL FRNTL BNDRY WILL PROGRESS TO NEAR I-70 CORRIDOR PER GFS/ECMWF/SREF SOLNS. SOUTH OF FRNTL BNDRY...PCPN LIKELY TO BE MORE SCATTERED. HAVE CAT POPS NORTH/CENTRAL AND LKLY POPS SOUTH THRU WED AFTN. WILL HIGHLIGHT HVY RAIN POTENTIAL WITH HWOILN. LO LVL FORCING WEAKENS BY LATE WED AFTN AS AFOREMENTIONED SFC WAVE PULLS AWAY TO THE EAST. MAY SEE A BIT OF A DECREASE IN PCPN COVERAGE AS FRNTL BNDRY DROPS BACK TO SOUTH WED NIGHT. MAIN SFC LO ASSOCD WITH PLAINS SYSTEM WILL LIFT INTO MID MISSISSIPPI VLY LATE WED NIGHT. 12Z MODEL GUIDANCE HAS LARGELY SHIFTED TOWARDS A SLOWER AND MORE NORTHERLY TRACK TO THIS LOW AS IT APPCHS FOR THURS. EXPECT PCPN COVERAGE WILL FILL BACK IN ACRS REGION TOWARDS DAYBREAK THURS AS FRNTL BNDRY MEANDERS ACRS FCST AREA. TEMPS...TRENDED CLOSER TO WARMER END OF GUID TEMPS FOR TONIGHT AND TUES WITH FRNTL BNDRY NOT EXPECTED TO DROP TOO FAR SOUTH OF FCST AREA. TEMPS FROM TUES NIGHT ON BECOME HIGHLY DEPENDENT ON LOCATION OF FRNTL BNDRY. TRENDED TEMPS MUCH CLOSER TO MAV AS GFS SOLN BRINGING BNDRY FURTHER NORTH ON WED/WED NIGHT. COULD VERY EASILY BE A 15-20 DEG TEMP SPREAD ACRS FCST AREA HOWEVER ON WED. RYAN && .LONG TERM /THURSDAY THROUGH MONDAY/... SURFACE LOW WILL BE MOVING OUT OF THE CENTRAL PLAINS ON THURSDAY MORNING...BUT MODELS ARE SHOWING A LOT OF DISCONTINUITY WITH ITS EVENTUAL TRACK INTO THE OHIO VALLEY. 00Z GFSENS MEAN AND 06Z GFS TOOK SURFACE LOW SOUTH OF THE OH RIVER...WHILE 12Z GFS AND NAM HAVE SHIFTED FURTHER NORTH WITH THE LOW TRACKING INTO NORTHERN OHIO. FORMER SCENARIO KEEPS STATIONARY FRONTAL BOUNDARY NEAR THE OHIO RIVER ON THURSDAY...WHILE THE LATTER BRINGS IT AT LEAST INTO OUR CENTRAL CWA IF NOT INTO NORTHERN OHIO. ECMWF SUPPORTS A SOLUTION THAT LEANS TOWARD TODAYS 12Z MODELS...SO FORECAST AT THE BEGINNING OF THE EXTENDED IS BASED ON A BLEND OF 12Z NAM...12Z GFS AND PREVIOUS FORECAST PACKAGE FOR CONTINUITY. THIS BRINGS THE WARM FRONT INTO OUR CENTRAL CWA ON THURS AND SLOWS DOWN THE LOW BY ABOUT 6-12 HOURS. THUS...INCREASED TEMPS ACROSS OUR SOUTHERN HALF ON THURSDAY...AND LINGERED POPS LONGER THURS NIGHT INTO EARLY FRIDAY TO ACCOUNT FOR THE SLOWER TREND OF THE MODELS. FLOW ALOFT BECOMES NORTHWESTERLY OVER THE WEEKEND WITH HIGH PRESSURE BUILDING IN OVER THE CENTRAL US. NEXT CHANCE FOR PRECIPITATION WILL BE WITH A COLD FRONT ON MONDAY. HAWBLITZEL && .AVIATION /18Z-18Z/... SCT-BKN FAIR WX CU IS FOUND BETWEEN THE INITIAL BATCH OF SHOWERS IN THE PRE-FRONTAL UPPER TROF AND THE ACTUAL COLD FRONT LOCATED OVER WRN ILL. ONCE WINDS UPSTREAM SWITCH TO THE W AFTER THE FRONT...IT IS NOTED THAT THERE IS A SIGNIFICANT AREA OF MVFR AND SOME IFR CIGS IN THE COLD POOL BEHIND IT. BELIEVE THAT UNTIL THE FRONT IS OVERTOP OF TAF SITES THE RAIN AND ISOLD THUNDERSTORMS WILL HOLD OFF. TRIED TO MITIGATE THE PRECIP THIS EVENING TO A 3 OR 4 HOUR PERIOD AND THEN LOWERED CIGS SIGNIFICANTLY IN THE POST FRONTAL AIRMASS. MODELS ARE DIFFERING ON THE TIMING OF THE WIND SHIFTS...I SPED UP THE TURN TO A NORTHEAST DIRECTION LATE TONIGHT AND EARLY TOMORROW VERSUS THE MODELS HOLDING IT OFF UNTIL DAYTIME TOMORROW. FRONT IS LACKING ANY SIGNIFICANT ACTIVITY THIS AFTERNOON...BUT THERE SHOULD BE ENOUGH ENERGY BUILT UP AHEAD OF IT TODAY TO SPARK AN EARLY ROUND OF CONVECTION THIS EVENING. FRANKS && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh