Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/23/15


AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1245 AM CDT TUE JUL 21 2015 .AVIATION... LINE OF TSRA MOVING INTO CENTRAL ARKANSAS...BUT SLOWLY WEAKENING. CURRENT THINKING IS THAT THIS LINE WILL DISSIPATE WITH ANOTHER WAVE MOVING ALONG THE FRONT DURING THE AFTERNOON TUESDAY. THERE MAY BE SOME TSRA ACROSS THE NORTH AROUND SUNRISE. VFR CONDITIONS WILL PREVAIL EXCEPT NEAR TSRA. && .PREV DISCUSSION... /ISSUED 953 PM CDT MON JUL 20 2015/ UPDATE... UPDATE TO THE FORECAST TO REFLECT CURRENT RADAR TRENDS. THIS EVENING...HAVE CONTINUED TO SEE ISOLATED STORMS DEVELOP AHEAD OF THE FRONT STRETCHING FROM BATESVILLE TO WALDRON. HRRR HAS THESE THUNDERSTORMS CONTINUING TO PUSH SOUTH AND EAST THROUGH THE NIGHT AS THEY WEAKEN. WITH THE SLOW MOVING FRONT REMAINING IN THE AREA AGAIN ON TUESDAY...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON TUESDAY. PREV DISCUSSION... /ISSUED 258 PM CDT MON JUL 20 2015/ SHORT TERM...TONIGHT THROUGH THURSDAY HIGH PRESSURE OVER THE AREA WILL MOVE SLIGHTLY WESTWARD TONIGHT AND TUESDAY. THIS IS GOING TO ALLOW A COLD FRONT TO MOVE INTO ARKANSAS FROM MISSOURI. THIS FRONT WILL SLOWLY WORK SOUTH THROUGH WEDNESDAY AND STALL IN SOUTH ARKANSAS WEDNESDAY. RAIN CHANCES WILL INCREASE ALONG AND NEAR THIS FRONT THROUGH THURSDAY. SOME THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL DUE TO ABUNDANT MOISTURE AVAILABLE. THE HEAT ADVISORY WILL EXPIRE EARLY THIS EVENING. TEMPERATURES THE NEXT FEW DAYS WILL BE A FEW DEGREES COOLER DUE TO CLOUD COVER AND RAIN CHANCES...SO HEAT INDICES WILL BE LOWER. LONG TERM...FRIDAY THROUGH MONDAY AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL CONTINUE TO DOMINATE THE AREA THROUGH THE EXTENDED TERM...WITH THE RIDGE CENTERED OVER THE SOUTHERN PLAINS THROUGHOUT THE PERIOD. AS THE RIDGE SLIPS A BIT WESTWARD...IT MAY ALLOW FOR SOME ISOLATED AFTERNOON AND EVENING THUNDERSTORMS TO DEVELOP...ESPECIALLY ACROSS THE NERN ZONES. OTHERWISE IT WILL REMAIN QUITE HOT...WITH AFTERNOON TEMPERATURES TOPPING OUT IN THE UPPER 90S TO AROUND 100 ACROSS MUCH OF THE STATE. && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...58
AREA FORECAST DISCUSSION
NWS TUCSON AZ
142 PM MST TUE JUL 21 2015 .SYNOPSIS...DRIER AIR WILL KEEP ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS EAST AND SOUTH OF TUCSON THROUGH THIS EVENING. MOISTURE WILL START TO INCREASE AS EARLY AS WEDNESDAY WITH CONTINUED ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS FROM TUCSON SOUTH AND EASTWARD. EXPECT ISOLATED TO SCATTERED STORMS FOR MUCH OF SOUTHEAST ARIZONA THURSDAY AND FRIDAY BEFORE A DRYING TREND RETURNS FOR THE WEEKEND. && .DISCUSSION...LATEST VISIBLE SATELLITE IMAGERY SHOWS CLEAR TO MOSTLY CLEAR SKIES NORTH AND WEST OF TUCSON WITH PARTLY CLOUDY SKIES SOUTH AND EAST OF TUCSON. KEMX RADAR IMAGERY DEPICTS ISOLATED SHOWERS AND A FEW THUNDERSTORMS ACROSS COCHISE COUNTY BUT THESE HAVE BEEN STRUGGLING OVER THE LAST HOUR OR SO. THE BEST MOISTURE AND INSTABILITY WILL PERSIST ACROSS COCHISE AND EASTERN SANTA CRUZ COUNTIES INTO THIS EVENING...WHERE ISOLATED SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE. WE ANTICIPATE THE STORMS WILL DISSIPATE AROUND SUNSET WITH THE LOSS OF DAYTIME HEATING. WE COULD SEE A COMPLEX OF STORMS PERSIST LATER INTO THE EVENING ACROSS NORTHEAST SONORA AS HINTED AT ON THE HRRR BUT SHOULD THIS SCENARIO OCCUR...IT IS EXPECTED TO HAVE HAVE LITTLE IMPACT ON THIS FORECAST AREA. IN THE LARGER SCALE...UPPER RIDGING CONTINUES ACROSS CENTRAL TEXAS AND IS ORIENTED AS SUCH THAT THE FLOW WILL BECOME MORE SOUTHERLY ACROSS THE REGION STARTING ON WEDNESDAY TO GRADUALLY IMPORT ADDITIONAL MOISTURE TO THE REGION. WE THINK THAT THE FAVORED REGION FOR STORMS ON WEDNESDAY WILL AGAIN BE SOUTH AND EAST OF TUCSON BUT ISOLATED STORMS ARE LIKELY TO BE AS FAR NORTH AND WEST AS THE TUCSON AREA BY WEDNESDAY AFTERNOON OR WEDNESDAY EVENING. EVEN HIGHER LEVELS OF MOISTURE WILL MOVE IN THURSDAY /WITH PWAT VALUES INCREASING TO ABOUT 1.5 INCHES/ ON SOUTHERLY FLOW. THIS SHOULD RESULT IN INCREASED COVERAGE OF STORMS FOR MOST OF THE AREA EXCEPT FOR THE WESTERN DESERTS. NOTE THOUGH THAT WITH SOUTHERLY UPPER LEVEL WINDS AS WELL...STORM TOP ANVILS WILL BE BLOWING OUT AHEAD OF THE STORMS WHICH IS A NEGATIVE FOR VALLEY STORMS AND LARGELY KILLED TUCSON STORMS THIS PAST WEEKEND. ADEQUATE MOISTURE WILL STILL PERSIST FRIDAY FOR A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS MOST OF THE AREA. FOR THIS WEEKEND...DRIER AIR WILL MOVE IN AS THE UPPER LEVEL RIDGE EXPANDS WESTWARD AND THE ORIENTATION PUTS A BROAD RIDGE AXIS INTO ARIZONA. MEANWHILE...LOWER TO MID LEVEL WESTERLY FLOW WILL TRANSPORT DRIER AIR IN FROM THE WEST INTO SOUTHEAST ARIZONA RESULTING IN JUST A SLIGHT CHANCE OF STORMS MAINLY FOR SOUTHERN AND EASTERN AREAS AGAIN. THIS WILL ALSO RESULT IN WARMER TEMPERATURES FOR THE WEEKEND. BY EARLY NEXT WEEK...AS THE FLOW BECOMES MORE SOUTH TO SOUTHEASTERLY AGAIN WITH PERHAPS SOME INVERTED TROUGH INFLUENCE TO OUR SOUTH...MOISTURE WILL INCREASE AND PERHAPS REVAMP SHOWER AND THUNDERSTORM COVERAGE. && .AVIATION...VALID THRU 23/00Z. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY TO THE SOUTH AND EAST OF KTUS THRU 22/03Z. BRIEF MVFR CONDITIONS POSSIBLE WITH WIND GUSTS TO 35 KTS NEAR STRONGER STORMS FOR KDUG. OTHERWISE...EXPECT DIMINISHED STORM ACTIVITY OVERNIGHT WITH FEW-SCT CLOUDS AROUND 8-10K FT. NORMAL DIURNAL SURFACE WIND TRENDS WILL PREVAIL OUTSIDE OF STORM INFLUENCE...GENERALLY UNDER 12 KTS. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS INCREASING AFTER 22/20Z...AGAIN MAINLY SOUTH AND EAST OF KTUS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...WARM TEMPERATURES AND A SLIGHTLY DRIER AIRMASS WILL LIMIT CONVECTION TO AREAS MAINLY EAST AND SOUTH OF TUCSON THROUGH WEDNESDAY. SOME INCREASED MOISTURE WILL RETURN TO THE AREA THURSDAY AND FRIDAY. THIS WILL BRING ADDITIONAL COVERAGE OF SHOWERS AND THUNDERSTORMS. BY THIS WEEKEND...SOMEWHAT DRIER AIR MAY REDUCE THUNDERSTORM COVERAGE AGAIN. TERRAIN-DRIVEN 20-FT WINDS WILL GENERALLY BE LESS THAN 15 MPH EXCEPT FOR SOME OCCASIONAL AFTERNOON GUSTINESS DUE TO DAYTIME HEATING. A FEW OF THE STRONGER THUNDERSTORMS MAY PRODUCE WIND GUSTS TO AROUND 40 MPH. .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...GL AVIATION/FIRE WEATHER...RH VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TUCSON AZ
914 AM MST TUE JUL 21 2015 .SYNOPSIS...A DRYING TREND WILL PUSH THE BEST CHANCES OF THUNDERSTORMS EAST AND SOUTH OF TUCSON THROUGH WEDNESDAY. A SOUTHERLY TO SOUTHEASTERLY FLOW SHOULD RETURN MOISTURE TO THE AREA WEDNESDAY NIGHT INTO THURSDAY. A SLIGHT DOWN SWING IN ACTIVITY IS EXPECTED OVER THE WEEKEND...BEFORE PICKING BACK UP AGAIN EARLY NEXT WEEK. EVEN SO...SHOWERS AND STORMS SHOULD BE CONFINED TO AREAS MAINLY BETWEEN TUCSON AND THE NEW MEXICO BORDER EACH DAY. && .DISCUSSION...CLEAR SKIES ACROSS SOUTHEAST ARIZONA THIS MORNING WITH SOUTHWESTERLY FLOW ALOFT OVER THE STATE. LATEST WV IMAGERY SHOWS DRY AIR ALOFT OVER MUCH OF THE STATE WITH A WELL DEFINED DEMARCATION LINE BETWEEN THIS DRY AIR AND MORE MOIST AIR ON A LINE FROM NEAR SIERRA VISTA TO CLIFTON. MEANWHILE...PRECIPITABLE WATER VALUES FROM VARIOUS SOURCES RANGE FROM ABOUT 1 TO 1.25 INCHES ACROSS THE AREA WHICH IS A LITTLE BIT DRIER THAN 24 HOURS AGO. THE DEMARCATION LINE SEEN ON THE WV IMAGERY IS OFTEN WHERE WE SEE CONVECTION INITIATE AND THIS IS SUPPORTED WELL BY THE VARIOUS CONVECTIVE RESOLVING MODELS INCLUDING THE HRRR AND UOFA WRF MODEL GUIDANCE WHICH TARGET SANTA CRUZ AND SOUTHERN COCHISE COUNTY FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. IN ADDITION...THE BEST INSTABILITY WITH MUCAPE VALUES ABOUT 1000-2000 J/KG ARE PROGGED ACROSS THIS AREA AS WELL. THUS...THE CURRENT FORECAST OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS SOUTH AND EAST OF TUCSON LOOKS GOOD...TRAILING OFF CONSIDERABLY TO JUST BELOW 10 PERCENT IN TUCSON. ALL IN ALL...COVERAGE SHOULD BE FAIRLY SIMILAR TO WHAT WE SAW YESTERDAY. NOTE THAT THE 12Z NAM IS DEVELOPING A BIG CONVECTIVE COMPLEX JUST SOUTH OF THE INTERNATIONAL BORDER ACROSS FROM COCHISE COUNTY TONIGHT...BUT DON`T SEE ANY REAL SUPPORT FOR THIS SCENARIO SO WILL DISCOUNT IT. MADE SOME MINOR TWEAKS TO THE POP FORECAST THIS AFTERNOON...OTHERWISE FORECAST REMAINS UNCHANGED. SEE PREVIOUS DISCUSSION BELOW FOR ADDITIONAL INFORMATION. && .AVIATION...VALID THRU 22/12Z. ISOLATED TO SCATTERED TSRA/SHRA MAINLY EAST AND SOUTH OF KTUS AND ESP NEAR TERRAIN AFT 21/18Z. BRIEF MVFR CIGS/VSBYS AND GUSTS TO 35 KTS PSBL TIL 22/03Z IN AND AROUND THE STRONGER TSRA. EXPECT FEW-SCT CLOUDS AT 8-10K FT WITH MORE COVERAGE DURING THE AFTERNOON/EVENING HOURS. SFC WINDS DIURNALLY DRIVEN AND GENERALLY LESS THAN 12 KTS OUTSIDE OF ANY TSRA/SHRA. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...WARM TEMPERATURES AND A SLIGHTLY DRIER AIRMASS WILL LIMIT CONVECTION TO AREAS MAINLY EAST AND SOUTH OF TUCSON THROUGH WEDNESDAY. SOME MOISTURE WILL ATTEMPT TO RETURN TO THE AREA AS EARLY AS THURSDAY...BUT ESPECIALLY FROM FRIDAY ONWARD. THIS WILL BRING BACK AN INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE COMING WEEKEND...BUT ESPECIALLY BY EARLY NEXT WEEK. TERRAIN-DRIVEN 20-FT WINDS WILL GENERALLY BE LESS THAN 15 MPH EXCEPT FOR SOME OCCASIONAL AFTERNOON GUSTINESS DUE TO DAYTIME HEATING. A FEW OF THE STRONGER THUNDERSTORMS MAY PRODUCE WIND GUSTS TO AROUND 40 MPH. && .PREV DISCUSSION...DURING THE MIDDLE OF THE WEEK THE MODELS KEEP THE HIGH QUASI-STATIONARY OVER THE SOUTHERN PLAINS...WITH THE PACIFIC TROUGH TO OUR NORTHWEST. DISTURBANCES MOVING UP TO THE NORTH ON THE WESTERN FLANK OF THE HIGH ARE EXPECTED TO INCREASE RAIN CHANCES A BIT AS THE MOISTURE PLUME ON THE WEST SIDE OF THE HIGH IS EXPECTED TO MOVE ACROSS EASTERN PARTS OF ARIZONA AND A LARGE PART OF NEW MEXICO. MOS NUMBERS INDICATE THAT THE NAM IS THE WETTEST...WHILE THE ECMWF IS THE DRIEST. HOWEVER...THE NAM/GFS/ECMWF ALL POINT TO AN UPSWING IN ACTIVITY WEDNESDAY NIGHT INTO THURSDAY. I DID MAKE ADJUSTMENTS TO THE POP FORECAST TO ACCOUNT FOR THIS...SO FOR NOW I SHOW LOW END CHANCES FOR AREAS MAINLY FROM TUCSON TO NOGALES TO DOUGLAS TO WILLCOX...AS WELL AS CHANCE POPS OVER THE WHITES. OVER THE FAR WESTERN DESERTS ONLY `SILENT` SINGLE DIGIT POPS FOR WEDNESDAY NIGHT INTO THURSDAY. BY LATE IN THE WEEK THE MODELS INDICATE THAT THE TROUGH AXIS OVER NORTHERN CALIFORNIA WILL MOVE TO A POSITION OVER THE CENTRAL PORTION OF THE STATE. IN RESPONSE TO THIS...MOISTURE IS PROGGED TO BE SHUNTED EAST AND SOUTH OF THIS AREA FOR A SLIGHT DECREASE IN THUNDERSTORM ACTIVITY DURING THE LATTER PART OF THE WEEK AND INTO THE WEEKEND. BY EARLY NEXT WEEK A MAJOR TROUGH MAKES ITS WAY INTO THE PACIFIC NORTHWEST WITH THE RIDGE STILL OVER THE CENTRAL AND SOUTHERN PLAINS...BUT WITH MODELS ADVERTISING AN INVERTED TROUGH ROUNDING THE SOUTHERN PERIPHERY OF THE HIGH AND SLIDING WEST OR NORTHWEST ACROSS NORTHERN MEXICO. THIS SHOULD RESULT IN AN INCREASE FOR SHOWERS AND THUNDERSTORMS DURING THE EARLY PART OF NEXT WEEK. FOR TUCSON...HIGH TEMPS WILL GENERALLY BE A DEGREE OR TWO EITHER SIDE OF NORMAL TODAY THROUGH FRIDAY...THEN 3 TO 5 DEGS ABOVE NORMAL THEREAFTER. LOWS WILL BE ABOUT 3 TO 5 DEGS ABOVE NORMAL EACH MORNING...ALTHOUGH THE WARMEST MORNINGS WILL LIKELY OCCUR SUNDAY AND MONDAY. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...GL AVIATION/FIRE WEATHER...FRENCH PREV DISCUSSION...MOLLERE VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TUCSON AZ
250 AM MST TUE JUL 21 2015 .SYNOPSIS...A DRYING TREND WILL PUSH THE BEST CHANCES OF THUNDERSTORMS EAST AND SOUTH OF TUCSON THROUGH MID WEEK. A SOUTHERLY TO SOUTHEASTERLY FLOW SHOULD RETURN MOISTURE TO THE AREA WEDNESDAY NIGHT INTO THURSDAY. A SLIGHT DOWN SWING IN ACTIVITY IS EXPECTED OVER THE WEEKEND...BEFORE PICKING BACK UP AGAIN EARLY NEXT WEEK. EVEN SO...SHOWERS AND STORMS SHOULD BE CONFINED TO AREAS MAINLY BETWEEN TUCSON AND THE NEW MEXICO BORDER EACH DAY. && .DISCUSSION...WATER VAPOR IMAGERY AND 21/00Z UPPER-AIR PLOTS SHOW A RIDGE CENTERED OVER THE SOUTHERN PLAINS...WITH A TROUGH AXIS EXTENDING FROM NORTHERN UTAH ACROSS NEVADA....CENTRAL CALIFORNIA AND INTO THE PACIFIC WATERS. A LARGE SWATH OF MID TO UPPER LEVEL DRY AIR CAN BE SEEN COVERING MUCH OF THE EASTERN PACIFIC...SOUTHERN CALIFORNIA...NORTHERN BAJA AND INTO MUCH OF ARIZONA. IR SATELLITE IMAGERY SHOWS CLOUDINESS MOSTLY TO OUR EAST OVER MUCH OF NEW MEXICO...NORTHERN MEXICO AND WEST TEXAS. THE ONLY CLOUDINESS OVER ARIZONA AT THIS TIME RESIDES OVER THE EXTREME SOUTHEAST CORNER OF THE STATE...SPECIFICALLY THE SOUTHEASTERN HALF OF COCHISE COUNTY. YESTERDAY AFTERNOON THE 21/00Z KTWC SOUNDING REVEALED A PW OF 1.49 INCHES...WITH A LIFTED INDEX OF MINUS 3 AND A MU CAPE OF AROUND 800 J/KG. SINCE THAT TIME THE SWATH OF DRY AIR HAS MOVED EVEN FARTHER TO THE NORTHEAST...SPREADING INTO SRN UTAH AND THE FOUR CORNERS REGION. HOWEVER...THE INTERFACE BETWEEN THIS DRY AIR AND THE MOIST AIR TO OUR EAST LIES ALONG A LINE GENERALLY FROM AROUND NOGALES TO SAFFORD AND INTO WEST CENTRAL NEW MEXICO. THIS LINE OF DEMARCATION BETWEEN THE DRY AND MOIST AIR SERVES AS A BATTLE ZONE FOR CONVECTION TO DEVELOP. CURRENT PRECIPITABLE WATER VALUES FROM VARIOUS SOURCES INDICATE THAT VALUES (FOR TUCSON) RANGE FROM AROUND 1.0 -1.25 INCHES. MODELS SHOW PW`S CONTINUING TO DECREASE A BIT MORE THIS AFTERNOON...WITH READINGS EXPECTED TO BE RIGHT AROUND...OR SLIGHTLY ABOVE THE 1 INCH MARK...WITH READINGS WELL BELOW 1 INCH OVER THE FAR WESTERN DESERTS OF PIMA COUNTY. MODELS INDICATE THAT THESE VALUES WILL CREEP BACK UP LATE WEDNESDAY AND INTO THURSDAY...WITH READINGS RANGING FROM 1.4 - 1.8 INCHES AS SOUTHERLY FLOW TRANSPORTS MOISTURE NORTHWARD. FOR THIS AFTERNOON...HIGH RESOLUTION MODELS SUCH AS THE U OF A WRF/NAM & GFS...AND THE HRRR SHOW VERY LITTLE ACTIVITY DEVELOPING OVER MY FORECAST AREA TODAY. WHAT DOES DEVELOP SHOULD BE ALONG THE AFOREMENTIONED DRY/MOIST AIR INTERFACE...WHICH AT THE PRESENT TIME LIES OVER THE EXTREME EASTERN PART OF MY FORECAST AREA. I INHERITED ISOLATED TO LOW END SCATTERED POP FOR MAINLY SANTA CRUZ AND SOUTHERN COCHISE COUNTIES AND ALSO THE WHITE MOUNTAINS OF NORTHERN GRAHAM AND GREENLEE COUNTIES. WE CAN REEVALUATE THIS IN THE MORNING WHEN THE 12Z SOUNDING ARRIVES...BUT FOR NOW THIS LOOKS REASONABLE. DURING THE MIDDLE OF THE WEEK THE MODELS KEEP THE HIGH QUASI- STATIONARY OVER THE SOUTHERN PLAINS...WITH THE PACIFIC TROUGH TO OUR NORTHWEST. DISTURBANCES MOVING UP TO THE NORTH ON THE WESTERN FLANK OF THE HIGH ARE EXPECTED TO INCREASE RAIN CHANCES A BIT AS THE MOISTURE PLUME ON THE WEST SIDE OF THE HIGH IS EXPECTED TO MOVE ACROSS EASTERN PARTS OF ARIZONA AND A LARGE PART OF NEW MEXICO. MOS NUMBERS INDICATE THAT THE NAM IS THE WETTEST...WHILE THE ECMWF IS THE DRIEST. HOWEVER...THE NAM/GFS/ECMWF ALL POINT TO AN UPSWING IN ACTIVITY WEDNESDAY NIGHT INTO THURSDAY. I DID MAKE ADJUSTMENTS TO THE POP FORECAST TO ACCOUNT FOR THIS...SO FOR NOW I SHOW LOW END CHANCES FOR AREAS MAINLY FROM TUCSON TO NOGALES TO DOUGLAS TO WILLCOX...AS WELL AS CHANCE POPS OVER THE WHITES. OVER THE FAR WESTERN DESERTS ONLY `SILENT` SINGLE DIGIT POPS FOR WEDNESDAY NIGHT INTO THURSDAY. BY LATE IN THE WEEK THE MODELS INDICATE THAT THE TROUGH AXIS OVER NORTHERN CALIFORNIA WILL MOVE TO A POSITION OVER THE CENTRAL PORTION OF THE STATE. IN RESPONSE TO THIS...MOISTURE IS PROGGED TO BE SHUNTED EAST AND SOUTH OF THIS AREA FOR A SLIGHT DECREASE IN THUNDERSTORM ACTIVITY DURING THE LATTER PART OF THE WEEK AND INTO THE WEEKEND. BY EARLY NEXT WEEK A MAJOR TROUGH MAKES ITS WAY INTO THE PACIFIC NORTHWEST WITH THE RIDGE STILL OVER THE CENTRAL AND SOUTHERN PLAINS...BUT WITH MODELS ADVERTISING AN INVERTED TROUGH ROUNDING THE SOUTHERN PERIPHERY OF THE HIGH AND SLIDING WEST OR NORTHWEST ACROSS NORTHERN MEXICO. THIS SHOULD RESULT IN AN INCREASE FOR SHOWERS AND THUNDERSTORMS DURING THE EARLY PART OF NEXT WEEK. FOR TUCSON...HIGH TEMPS WILL GENERALLY BE A DEGREE OR TWO EITHER SIDE OF NORMAL TODAY THROUGH FRIDAY...THEN 3 TO 5 DEGS ABOVE NORMAL THEREAFTER. LOWS WILL BE ABOUT 3 TO 5 DEGS ABOVE NORMAL EACH MORNING...ALTHOUGH THE WARMEST MORNINGS WILL LIKELY OCCUR SUNDAY AND MONDAY. && .AVIATION...VALID THRU 22/12Z. ISOLATED TO SCATTERED TSRA/SHRA MAINLY EAST AND SOUTH OF KTUS AND ESP NEAR TERRAIN AFT 21/18Z. BRIEF MVFR CIGS/VSBYS AND GUSTS TO 35 KTS PSBL TIL 22/03Z IN AND AROUND THE STRONGER TSRA. EXPECT FEW-SCT CLOUDS AT 8-10K FT WITH MORE COVERAGE DURING THE AFTERNOON/EVENING HOURS. SFC WINDS DIURNALLY DRIVEN AND GENERALLY LESS THAN 12 KTS OUTSIDE OF ANY TSRA/SHRA. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...WARM TEMPERATURES AND A SLIGHTLY DRIER AIRMASS WILL LIMIT CONVECTION TO AREAS MAINLY EAST AND SOUTH OF TUCSON THROUGH WEDNESDAY. SOME MOISTURE WILL ATTEMPT TO RETURN TO THE AREA AS EARLY AS THURSDAY...BUT ESPECIALLY FROM FRIDAY ONWARD. THIS WILL BRING BACK AN INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE COMING WEEKEND...BUT ESPECIALLY BY EARLY NEXT WEEK. TERRAIN-DRIVEN 20-FT WINDS WILL GENERALLY BE LESS THAN 15 MPH EXCEPT FOR SOME OCCASIONAL AFTERNOON GUSTINESS DUE TO DAYTIME HEATING. A FEW OF THE STRONGER THUNDERSTORMS MAY PRODUCE WIND GUSTS TO AROUND 40 MPH. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MOLLERE AVIATION/FIRE WEATHER...FRENCH VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
917 AM PDT TUE JUL 21 2015 .SYNOPSIS...LINGERING MOISTURE FROM THE REMNANTS OF DOLORES WILL RESULT IN A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE SOUTHEASTERN PORTIONS OF THE REGION THROUGH THE AFTERNOON. OTHERWISE...COOLER CONDITIONS CAN BE EXPECTED THROUGH THURSDAY. DRY WEATHER CONDITIONS AND NEAR NORMAL TEMPERATURES ARE LIKELY FOR LATE WEEK AND INTO THE UPCOMING WEEKEND. && .DISCUSSION...AS OF 09:15 AM PDT TUESDAY...THE MARINE LAYER MADE A RAPID RETURN OVERNIGHT AND IS AROUND 1500 FEET DEEP THIS MORNING. AS A RESULT...THE MARINE INFLUENCE HAS TEMPERATURES DOWN 7 TO 13 DEGREES COMPARED TO 24 HOURS AGO FOR MOST LOCATIONS. DO EXPECT COASTAL CLOUDS TO BURN-OFF INLAND WITH MOSTLY SUNNY CONDITIONS THIS AFTERNOON. HAVE MADE MINOR ADJUSTMENTS TO ACCOUNT FOR A SLIGHT CHANCE OF SHOWERS OVER NAPA AND CONTRA COSTA COUNTIES AS EARLY RADAR RETURNS SUGGESTED A FEW SHOWERS OVER SOLANO COUNTY HEADING WESTWARD. THIS IS LIKELY DUE TO A WEAK MID/UPPER LEVEL DISTURBANCE INTERACTING WITH ABUNDANT MOISTURE ALOFT. WILL CONTINUE WITH THE SLIGHT CHANCE OF SHOWERS AND/OR THUNDERSTORMS OVER THE INLAND...SOUTHEASTERN PORTION OF THE REGION THIS AFTERNOON AND EVENING AS THE ATMOSPHERE BECOMES MORE UNSTABLE AND LINGERING MOISTURE REMAINS IN PLACE. OTHERWISE...MOST LOCATIONS CAN EXPECT TYPICAL MID/LATE JULY WEATHER FOR THE NEXT FEW DAYS. && .PREV DISCUSSION...AS OF 3:00 AM PDT TUESDAY...AFTER A COUPLE OF VERY WARM AND FAIRLY HUMID DAYS ACROSS OUR REGION TODAY WILL FEEL QUITE A BIT COOLER. IN FACT...24 HOUR CHANGE PRODUCT ALREADY SHOWS THE BIG CHANGE WITH ALMOST ALL SPOTS 7 TO 13 DEGREES UNDER VALUES FROM YESTERDAY ALONG WITH SLIGHTLY LOWER DEW POINTS. SYNOPTICALLY REMNANTS FROM FORMER HURRICANE DOLORES CONTINUES TO SPIN OFF TO OUR SOUTHWEST. DUE TO SOME INSTABILITY PLUS MID LEVEL MOISTURE THERE REMAINS AN OUTSIDE CHANCE OF A FEW SHOWERS OR EVEN A THUNDERSTORM FIRING UP OVER PARTS OF MONTEREY AND SAN BENITO COUNTIES. WILL KEEP POPS AROUND 20 PERCENT FOR THAT AREA. FOR THE REST OF THE CWA LOOK FOR DRY CONDITIONS WITH HIGHS 4 TO 8 DEGREES COOLER THAN YESTERDAY. MODELS REMAIN IN GOOD AGREEMENT THAT A LONGWAVE TROF WILL MOVE IN FROM THE NORTH AND STRETCH FROM NORCAL INTO CENTRAL CANADA STARTING TONIGHT. THIS FEATURE IS EXPECTED TO REMAIN NEARLY STATIONARY THROUGH AT LEAST THURSDAY WHICH WILL HELP TO DROP TEMPS TO COOLER THAN NORMAL VALUES FOR ALMOST ALL SPOTS. SPOTTY COASTAL DRIZZLE WILL ALSO BE POSSIBLE EACH NIGHT INTO THE MORNING HOURS. THE TROF WILL LIFT TO THE NORTHEAST FRIDAY AND SATURDAY AS A RIDGE OF HIGH PRESSURE BUILDS FROM THE SOUTHEAST. THIS WILL HELP TO PUSH HIGHS CLOSER TO NORMAL BY THE END OF THE WEEK GOING INTO THE START OF NEXT WEEK. && .AVIATION...AS OF 4:50 AM PDT TUESDAY... A RELATIVELY SHALLOW MARINE LAYER HAS CREPT INTO THE INLAND VALLEYS THIS MORNING... LEADING TO LIFR TO MVFR CIGS ACROSS REGIONAL TAF SITES. THE SFO TO SAC ONSHORE GRADIENT IS MORE THAN TWICE AS LARGE VERSUS 24 HOURS AGO... WHICH CONTRIBUTED TO THE INCREASED ONSHORE PUSH. LARGE SPREAD OF MODEL OUPUT IS LEADING TO A LOW TO MODERATE CONFIDENCE FORECAST FOR MORNING MIXOUT TIMES. SATELLITE IMAGERY SHOWS A DECK OF MID LEVEL CLOUDS LEFT OVER FROM YESTERDAYS SIERRA CONVECTION ADVANCING FROM THE EAST. HRRR MODEL SUGGESTING THAT A FEW ISOLATED AREAS OF -RA/DZ MAY BE POSSIBLE FROM THIS DECK... BUT EXPECT VIRGA TO BE PREDOMINATE WX COND. VICINITY OF KSFO... LOW TO MODERATE CONFIDENCE. IFR CIGS THROUGH 1630-17Z. MVFR POSSIBLE THROUGH 1730-19Z. ADVANCING MID LEVEL MOISTURE FROM THE EAST MAY LEAD TO -RA IN THE VICINITY BTWN 15-19Z. ONSHORE WINDS 15-20KT WITH GUSTS TO 25KT THIS AFTERNOON. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS... MODERATE CONFIDENCE. WIDESPREAD IFR CIGS THROUGH 18Z... WITH LOCAL IFR/MVFR CIGS LINGERING TO 20-21Z. EARLIER RETURN OF IFR CIGS TONIGHT. ONSHORE WINDS 10 TO 15KT. && .MARINE...AS OF 09:15 AM PDT TUESDAY...HIGH PRESSURE WILL REMAIN OFF THE PACIFIC NORTHWEST COAST THROUGH FRIDAY. THIS WILL KEEP MODERATE NORTHWEST WINDS ACROSS THE COASTAL WATERS WITH THE STRONGEST WINDS OVER THE NORTHERN WATERS. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 3 PM SCA...PT ARENA TO PT REYES 0-10 NM FROM 3 PM && $$ PUBLIC FORECAST: RGASS AVIATION: DRP MARINE: W PI VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
451 AM PDT TUE JUL 21 2015 .SYNOPSIS...LINGERING MOISTURE FROM THE REMNANTS OF DOLORES WILL RESULT IN A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE SOUTHEASTERN PORTIONS OF THE REGION THROUGH THE AFTERNOON. OTHERWISE...COOLER CONDITIONS CAN BE EXPECTED THROUGH THURSDAY. DRY WEATHER CONDITIONS AND NEAR NORMAL TEMPERATURES ARE LIKELY FOR LATE WEEK AND INTO THE UPCOMING WEEKEND. && .DISCUSSION...AS OF 3:00 AM PDT TUESDAY...AFTER A COUPLE OF VERY WARM AND FAIRLY HUMID DAYS ACROSS OUR REGION TODAY WILL FEEL QUITE A BIT COOLER. IN FACT...24 HOUR CHANGE PRODUCT ALREADY SHOWS THE BIG CHANGE WITH ALMOST ALL SPOTS 7 TO 13 DEGREES UNDER VALUES FROM YESTERDAY ALONG WITH SLIGHTLY LOWER DEW POINTS. SYNOPTICALLY REMNANTS FROM FORMER HURRICANE DOLORES CONTINUES TO SPIN OFF TO OUR SOUTHWEST. DUE TO SOME INSTABILITY PLUS MID LEVEL MOISTURE THERE REMAINS AN OUTSIDE CHANCE OF A FEW SHOWERS OR EVEN A THUNDERSTORM FIRING UP OVER PARTS OF MONTEREY AND SAN BENITO COUNTIES. WILL KEEP POPS AROUND 20 PERCENT FOR THAT AREA. FOR THE REST OF THE CWA LOOK FOR DRY CONDITIONS WITH HIGHS 4 TO 8 DEGREES COOLER THAN YESTERDAY. MODELS REMAIN IN GOOD AGREEMENT THAT A LONGWAVE TROF WILL MOVE IN FROM THE NORTH AND STRETCH FROM NORCAL INTO CENTRAL CANADA STARTING TONIGHT. THIS FEATURE IS EXPECTED TO REMAIN NEARLY STATIONARY THROUGH AT LEAST THURSDAY WHICH WILL HELP TO DROP TEMPS TO COOLER THAN NORMAL VALUES FOR ALMOST ALL SPOTS. SPOTTY COASTAL DRIZZLE WILL ALSO BE POSSIBLE EACH NIGHT INTO THE MORNING HOURS. THE TROF WILL LIFT TO THE NORTHEAST FRIDAY AND SATURDAY AS A RIDGE OF HIGH PRESSURE BUILDS FROM THE SOUTHEAST. THIS WILL HELP TO PUSH HIGHS CLOSER TO NORMAL BY THE END OF THE WEEK GOING INTO THE START OF NEXT WEEK. && .AVIATION...AS OF 4:50 AM PDT TUESDAY... A RELATIVELY SHALLOW MARINE LAYER HAS CREPT INTO THE INLAND VALLEYS THIS MORNING... LEADING TO LIFR TO MVFR CIGS ACROSS REGIONAL TAF SITES. THE SFO TO SAC ONSHORE GRADIENT IS MORE THAN TWICE AS LARGE VERSUS 24 HOURS AGO... WHICH CONTRIBUTED TO THE INCREASED ONSHORE PUSH. LARGE SPREAD OF MODEL OUPUT IS LEADING TO A LOW TO MODERATE CONFIDENCE FORECAST FOR MORNING MIXOUT TIMES. SATELLITE IMAGERY SHOWS A DECK OF MID LEVEL CLOUDS LEFT OVER FROM YESTERDAYS SIERRA CONVECTION ADVANCING FROM THE EAST. HRRR MODEL SUGGESTING THAT A FEW ISOLATED AREAS OF -RA/DZ MAY BE POSSIBLE FROM THIS DECK... BUT EXPECT VIRGA TO BE PREDOMINATE WX COND. VICINITY OF KSFO... LOW TO MODERATE CONFIDENCE. IFR CIGS THROUGH 1630-17Z. MVFR POSSIBLE THROUGH 1730-19Z. ADVANCING MID LEVEL MOISTURE FROM THE EAST MAY LEAD TO -RA IN THE VICINITY BTWN 15-19Z. ONSHORE WINDS 15-20KT WITH GUSTS TO 25KT THIS AFTERNOON. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS... MODERATE CONFIDENCE. WIDESPREAD IFR CIGS THROUGH 18Z... WITH LOCAL IFR/MVFR CIGS LINGERING TO 20-21Z. EARLIER RETURN OF IFR CIGS TONIGHT. ONSHORE WINDS 10 TO 15KT. && .MARINE...AS OF 04:29 AM PDT TUESDAY...NORTHWEST WINDS INCREASE ACROSS THE COASTAL WATER LATE TODAY AS A DRY TROUGH APPROACHES THE REGION. THE STRONGEST WINDS ARE EXPECTED OVER THE NORTHERN OUTER WATERS TONIGHT. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 3 PM SCA...PT ARENA TO PT REYES 0-10 NM FROM 3 PM && $$ PUBLIC FORECAST: BELL AVIATION: DRP MARINE: DRP VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1210 PM MDT TUE JUL 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM MDT TUE JUL 21 2015 ...STRONG TO SEVERE STORMS POSSIBLE ACROSS THE EASTERN MTS AND PLAINS... CURRENT WATER VAPOR IMAGERY INDICATING INCREASING SOUTH TO SOUTHWEST FLOW ALOFT ACROSS THE REGION AS A SHORT WAVE TROUGH IS TRANSLATING ACROSS THE SOUTHERN CALIFORNIA COAST AND SOUTHERN GREAT BASIN AT THIS TIME. WATER VAPOR IMAGERY IS INDICATING THE MONSOONAL MOISTURE PLUME ACROSS AT THE SOUTHERN AND CENTRAL ROCKIES WITH MUCH DRIER AIR WITHIN THE FLOW ALOFT WORKING ITS WAY ACROSS THE DESERT SW AND INTO WESTERN COLORADO AT THIS TIME. MINOR EMBEDDED DISTURBANCES ARE EVIDENT WITHIN THE SOUTH TO SOUTHERLY FLOW ACROSS THE SOUTHERN ROCKIES...WITH AN MCV AND REMNANTS OF LAST NIGHTS MCS CAN ALSO BE SEEN ACROSS THE OKLAHOMA PANHANDLE AT THIS TIME. COMPLEX FORECAST THIS MORNING WITH LATEST MODELS...EVEN THE HIGHER RES HRRR AND RUC...NOT DOING WELL AND CONTINUE TO PRINT OUT CONVECTIVE QPF BULLSEYES ACROSS THE AREA EARLY THIS MORNING. AT ANY RATE...SHOULD SEE LEE TROUGHING ACROSS THE I-25 CORRIDOR THROUGH THE MORNING AND EARLY AFTERNOON AS SOUTHWEST FLOW ALOFT CONTINUES TO INCREASE AHEAD OF SOUTHERN CALIFORNIA SHORT WAVE. THIS WILL LEAD TO INCREASING SOUTH TO SOUTHEAST LOW TO MID LEVEL UPSLOPE FLOW ACROSS THE EASTERN MTS THROUGH THE UPPER ARKANSAS RIVER VALLEY. WITH AMPLE MOISTURE AND POSSIBLE ADDED LIFT FROM THE SOUTHERN ROCKIES MINOR DISTURBANCES LIFTING NORTH ACROSS SOUTH CENTRAL COLORADO...SHOULD SEE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER AND NEAR THE HIGHER TERRAIN THROUGH THE LATE MORNING AND AFTERNOON. FURTHER EAST ACROSS THE I-25 CORRIDOR AND THE SOUTHEASTERN PLAINS...SUBSIDENCE ON THE BACKSIDE OF THE OK PANHANDLE MCV COULD KEEP CONVECTION AT BAY THROUGH THE MORNING...WITH COOL UPSLOPE FLOW ALSO POSSIBLY KEEPING CONDITIONS TOO STABLE THIS AFTERNOON...LEADING TO EASTERN MOUNTAIN STORMS WEAKENING AS THEY PUSH EAST OFF THE HIGHER TERRAIN. HOWEVER...IF ENOUGH INSTABILITY CAN BE GENERATED...THERE WILL BE ENOUGH SHEAR FOR SUPERCELL DEVELOPMENT SUPPORTING STRONG TO SEVERE STORMS PRODUCING LARGE HAIL TO AROUND AN INCH IN DIAMETER AND DAMAGING WIND GUSTS IN EXCESS OF 60 MPH. STORMS THAT DO DEVELOP WILL ALSO BE CAPABLE OF PRODUCING HEAVY RAINFALL...THOUGH WITH INCREASING FLOW ALOFT...STORMS WILL BE MOVING AT A GOOD CLIP TO LIMIT FLASH FLOODING POTENTIAL. THE ONE CAVET WILL BE THE POTENTIAL FOR TRAINING STORMS...ESPECIALLY ACROSS THE EASTERN MTS AND PALMER DVD...WITH SOUTH TO SOUTHEAST LOW AND MID LEVEL FLOW. WITH THAT SAID...CONSIDERED ISSUING A FLASH FLOOD WATCH FOR THE BURN SCARS IN EL PASO COUNTY...BUT THERE REMAINS TOO MANY QUESTION ON GENERATING ENOUGH INSTABILITY TO ISSUE AT THIS TIME. DRIER AIR ALOFT CONTINUES TO WORK INTO THE AREA TONIGHT AS SHORT WAVE TRANSLATES ACROSS THE CENTRAL ROCKIES. LEE TROUGHING LIFTS OUT ACROSS THE EASTERN PLAINS AND COULD BE A FOCUS CONVECTION THIS EVENING WITH STORMS DIMINISHING FROM WEST TO EAST THROUGH THE LATE EVENING AND OVERNIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 346 AM MDT TUE JUL 21 2015 WESTERLY MID/UPPER LEVEL FLOW ON WED ALLOWS PLUME OF RATHER DEEP DRY AIR TO SPREAD ACROSS THE STATE...LEADING TO A PRONOUNCED DOWNTURN IN CONVECTION ALL AREAS WED AFTERNOON AND EVENING. STILL SOME SHALLOW RESIDUAL MOISTURE HANGING ON OVER THE MOUNTAINS...WHICH WILL LEAD TO SOME WEAK TSRA WED AFTERNOON OVER THE HIGHER TERRAIN...THOUGH OVERALL STRENGTH/COVERAGE OF STORMS WILL BE PALTRY. MAX TEMPS WED WILL CLIMB CONSIDERABLY WITH DRY AIR AND DOWNSLOPE GRADIENT...AND 90S WILL REAPPEAR ACROSS MOST OF THE SOUTHEAST PLAINS. DRY AIR PERSISTS ON THU WITH A REPEAT OF WEAK MOUNTAIN CONVECTION IN THE AFTERNOON...WITH MAX TEMPS ADDING ANOTHER 3-5F OVER THE PLAINS...1-3F WARMER ACROSS THE HIGHER ELEVATIONS. WESTERLY FLOW ALOFT INCREASES FRI AS UPPER WAVE MOVES THROUGH THE NORTHERN ROCKIES INTO THE HIGH PLAINS BY EVENING. WEAK COLD FRONT WILL PUSH THROUGH THE PLAINS DURING THE DAY...BUT MOISTURE IS LACKING AND POST FRONTAL UPSLOPE IS INITIALLY WEAK...SO DOUBTFUL BOUNDARY WILL HAVE MUCH IMPACT ON PRECIP CHANCES...AND WILL KEEP JUST THE USUAL LOW POPS FOR ISOLATED STORMS OVER THE MOUNTAINS. UPPER RIDGE OVER TEXAS BEGINS TO SLOWLY DRIFT EASTWARD OVER THE WEEKEND...WHICH WILL ALLOW SOUTHERLY FLOW TO REDEVELOP OVER THE DESERT SW...LEADING TO A RENEWED INFLUX OF MOISTURE AND INCREASING TSRA CHANCES MOST LOCATIONS BEGINNING SAT AFTERNOON/EVENING AND CONTINUING INTO SUN. RIDGE THEN REMAINS EAST OF THE AREA NEXT WEEK...WITH FAIRLY STRONG MONSOON TAP MON PERSISTING INTO MID WEEK. MAX TEMPS WILL LIKELY PEAK ON FRI...THEN DRIFT SLOWLY DOWNWARD THROUGH THE WEEKEND INTO NEXT WEEK AS AIR MASS MOISTENS AND CONVECTIVE CLOUDINESS SHAVES A FEW DEGF OFF OF DAYTIME READINGS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1140 AM MDT TUE JUL 21 2015 PLENTY OF MOISTURE IN PLACE TO PRODUCE WIDESPREAD CONVECTION OVER AND NEAR THE HIGHER TERRAIN THIS AFTN AND EVE. STORMS THAT DEVELOP MAY PRODUCE PERIODS OF LOCALLY HEAVY RAINFALL AND MVFR TO IFR CONDITIONS AT TERMINALS. COULD ALSO SEE STRONG TO SEVERE STORMS ALONG THE I25 CORRIDOR AND PORTIONS OF THE E PLAINS THROUGH THIS EVENING. LARGE HAIL TO AROUND AN INCH IN DIAMETER AND GUSTY OUTFLOW WINDS TO AROUND 60 MPH WILL BE POSSIBLE FOR KCOS SOUTH TO KTAD...AND EAST TO KLHX. STORMS ARE EXPECTED TO DIMINISH FROM WEST TO EAST THROUGH THE EVENING HOURS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MW LONG TERM...PETERSEN AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
431 AM MDT TUE JUL 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM MDT TUE JUL 21 2015 ...STRONG TO SEVERE STORMS POSSIBLE ACROSS THE EASTERN MTS AND PLAINS... CURRENT WATER VAPOR IMAGERY INDICATING INCREASING SOUTH TO SOUTHWEST FLOW ALOFT ACROSS THE REGION AS A SHORT WAVE TROUGH IS TRANSLATING ACROSS THE SOUTHERN CALIFORNIA COAST AND SOUTHERN GREAT BASIN AT THIS TIME. WATER VAPOR IMAGERY IS INDICATING THE MONSOONAL MOISTURE PLUME ACROSS AT THE SOUTHERN AND CENTRAL ROCKIES WITH MUCH DRIER AIR WITHIN THE FLOW ALOFT WORKING ITS WAY ACROSS THE DESERT SW AND INTO WESTERN COLORADO AT THIS TIME. MINOR EMBEDDED DISTURBANCES ARE EVIDENT WITHIN THE SOUTH TO SOUTHERLY FLOW ACROSS THE SOUTHERN ROCKIES...WITH AN MCV AND REMNANTS OF LAST NIGHTS MCS CAN ALSO BE SEEN ACROSS THE OKLAHOMA PANHANDLE AT THIS TIME. COMPLEX FORECAST THIS MORNING WITH LATEST MODELS...EVEN THE HIGHER RES HRRR AND RUC...NOT DOING WELL AND CONTINUE TO PRINT OUT CONVECTIVE QPF BULLSEYES ACROSS THE AREA EARLY THIS MORNING. AT ANY RATE...SHOULD SEE LEE TROUGHING ACROSS THE I-25 CORRIDOR THROUGH THE MORNING AND EARLY AFTERNOON AS SOUTHWEST FLOW ALOFT CONTINUES TO INCREASE AHEAD OF SOUTHERN CALIFORNIA SHORT WAVE. THIS WILL LEAD TO INCREASING SOUTH TO SOUTHEAST LOW TO MID LEVEL UPSLOPE FLOW ACROSS THE EASTERN MTS THROUGH THE UPPER ARKANSAS RIVER VALLEY. WITH AMPLE MOISTURE AND POSSIBLE ADDED LIFT FROM THE SOUTHERN ROCKIES MINOR DISTURBANCES LIFTING NORTH ACROSS SOUTH CENTRAL COLORADO...SHOULD SEE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER AND NEAR THE HIGHER TERRAIN THROUGH THE LATE MORNING AND AFTERNOON. FURTHER EAST ACROSS THE I-25 CORRIDOR AND THE SOUTHEASTERN PLAINS...SUBSIDENCE ON THE BACKSIDE OF THE OK PANHANDLE MCV COULD KEEP CONVECTION AT BAY THROUGH THE MORNING...WITH COOL UPSLOPE FLOW ALSO POSSIBLY KEEPING CONDITIONS TOO STABLE THIS AFTERNOON...LEADING TO EASTERN MOUNTAIN STORMS WEAKENING AS THEY PUSH EAST OFF THE HIGHER TERRAIN. HOWEVER...IF ENOUGH INSTABILITY CAN BE GENERATED...THERE WILL BE ENOUGH SHEAR FOR SUPERCELL DEVELOPMENT SUPPORTING STRONG TO SEVERE STORMS PRODUCING LARGE HAIL TO AROUND AN INCH IN DIAMETER AND DAMAGING WIND GUSTS IN EXCESS OF 60 MPH. STORMS THAT DO DEVELOP WILL ALSO BE CAPABLE OF PRODUCING HEAVY RAINFALL...THOUGH WITH INCREASING FLOW ALOFT...STORMS WILL BE MOVING AT A GOOD CLIP TO LIMIT FLASH FLOODING POTENTIAL. THE ONE CAVET WILL BE THE POTENTIAL FOR TRAINING STORMS...ESPECIALLY ACROSS THE EASTERN MTS AND PALMER DVD...WITH SOUTH TO SOUTHEAST LOW AND MID LEVEL FLOW. WITH THAT SAID...CONSIDERED ISSUING A FLASH FLOOD WATCH FOR THE BURN SCARS IN EL PASO COUNTY...BUT THERE REMAINS TOO MANY QUESTION ON GENERATING ENOUGH INSTABILITY TO ISSUE AT THIS TIME. DRIER AIR ALOFT CONTINUES TO WORK INTO THE AREA TONIGHT AS SHORT WAVE TRANSLATES ACROSS THE CENTRAL ROCKIES. LEE TROUGHING LIFTS OUT ACROSS THE EASTERN PLAINS AND COULD BE A FOCUS CONVECTION THIS EVENING WITH STORMS DIMINISHING FROM WEST TO EAST THROUGH THE LATE EVENING AND OVERNIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 346 AM MDT TUE JUL 21 2015 WESTERLY MID/UPPER LEVEL FLOW ON WED ALLOWS PLUME OF RATHER DEEP DRY AIR TO SPREAD ACROSS THE STATE...LEADING TO A PRONOUNCED DOWNTURN IN CONVECTION ALL AREAS WED AFTERNOON AND EVENING. STILL SOME SHALLOW RESIDUAL MOISTURE HANGING ON OVER THE MOUNTAINS...WHICH WILL LEAD TO SOME WEAK TSRA WED AFTERNOON OVER THE HIGHER TERRAIN...THOUGH OVERALL STRENGTH/COVERAGE OF STORMS WILL BE PALTRY. MAX TEMPS WED WILL CLIMB CONSIDERABLY WITH DRY AIR AND DOWNSLOPE GRADIENT...AND 90S WILL REAPPEAR ACROSS MOST OF THE SOUTHEAST PLAINS. DRY AIR PERSISTS ON THU WITH A REPEAT OF WEAK MOUNTAIN CONVECTION IN THE AFTERNOON...WITH MAX TEMPS ADDING ANOTHER 3-5F OVER THE PLAINS...1-3F WARMER ACROSS THE HIGHER ELEVATIONS. WESTERLY FLOW ALOFT INCREASES FRI AS UPPER WAVE MOVES THROUGH THE NORTHERN ROCKIES INTO THE HIGH PLAINS BY EVENING. WEAK COLD FRONT WILL PUSH THROUGH THE PLAINS DURING THE DAY...BUT MOISTURE IS LACKING AND POST FRONTAL UPSLOPE IS INITIALLY WEAK...SO DOUBTFUL BOUNDARY WILL HAVE MUCH IMPACT ON PRECIP CHANCES...AND WILL KEEP JUST THE USUAL LOW POPS FOR ISOLATED STORMS OVER THE MOUNTAINS. UPPER RIDGE OVER TEXAS BEGINS TO SLOWLY DRIFT EASTWARD OVER THE WEEKEND...WHICH WILL ALLOW SOUTHERLY FLOW TO REDEVELOP OVER THE DESERT SW...LEADING TO A RENEWED INFLUX OF MOISTURE AND INCREASING TSRA CHANCES MOST LOCATIONS BEGINNING SAT AFTERNOON/EVENING AND CONTINUING INTO SUN. RIDGE THEN REMAINS EAST OF THE AREA NEXT WEEK...WITH FAIRLY STRONG MONSOON TAP MON PERSISTING INTO MID WEEK. MAX TEMPS WILL LIKELY PEAK ON FRI...THEN DRIFT SLOWLY DOWNWARD THROUGH THE WEEKEND INTO NEXT WEEK AS AIR MASS MOISTENS AND CONVECTIVE CLOUDINESS SHAVES A FEW DEGF OFF OF DAYTIME READINGS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 346 AM MDT TUE JUL 21 2015 PATCHY MVFR AND IFR LOW CLOUDS REMAIN A CONCERN AT COS AND ALS THROUGH DAYBREAK...WITH AMPLE MOISTURE IN PLACE AND DEVELOPING UPSLOPE FLOW ACROSS THE EASTERN PLAINS. WIDESPREAD PRECIP IS EXPECTED OVER AND NEAR THE HIGHER TERRAIN WITH MONSOONAL MOISTURE IN PLACE ACROSS THE AREA AND AN UPPER LEVEL SYSTEM MOVING ACROSS THE AREA THROUGH THE AFTERNOON AND EVENING. STORMS THAT DEVELOP WILL PRODUCE LOCALLY HEAVY RAINFALL AND PRODUCE MVFR AND LOCAL IFR CONDITIONS AT TERMINALS. COULD ALSO SEE STRONG TO SEVERE STORMS ACROSS THE I-25 CORRIDOR AND EASTERN PLAINS THIS AFTERNOON AND EVENING. IF THERE IS ENOUGH INSTABILITY...LARGE HAIL TO AROUND AND INCH IN DIAMETER AND GUSTY OUTFLOW WINDS TO AROUND 60 MPH WILL BE POSSIBLE...ESPECIALLY AT COS. DRIER WESTERLY FLOW WORKS INTO THE AREA LATER TONIGHT...WITH STORMS DIMINISHING FROM WEST TO EAST THROUGH THE EVENING HOURS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MW LONG TERM...PETERSEN AVIATION...MW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1123 PM MDT MON JUL 20 2015 .UPDATE... ISSUED AT 627 PM MDT MON JUL 20 2015 UPDATED TO ADJUST POPS PER LATEST RADAR AND OBS AS WELL AS HIGH RES MODEL DATA. ROSE && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 243 PM MDT MON JUL 20 2015 CURRENTLY...A HEALTHY AMOUNT OF CLOUD COVER THROUGH MUCH OF THE DAY HAS PUT A DAMPER ON MUCH OF THE POTENTIAL ACTIVITY FOR TODAY...AND CONVECTION CURRENTLY OVER THE HIGHER TERRAIN WAS SLOW TO START. NO REPORTS OF HEAVY RAINFALL AS OF YET...AS SOUNDINGS THIS MORNING CONFIRMED THAT THE GREATER AMOUNT OF MOISTURE IS AVAILABLE IN NM. TEMPS HAVE WARMED INTO THE UPPER 70S TO UPPER 80S ACROSS THE PLAINS AS OF 3 PM...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS. SFC WINDS ACROSS THE PLAINS HAVE BEEN GENERALLY OUR OF THE EAST...BUT WITHIN THE PAST COUPLE OF HOURS HAVE SHIFTED TO A MORE S-SE DIRECTION. TONIGHT...A FLAT RIDGE OF HIGH PRESSURE OVER THE SOUTHERN U.S. WILL STAY THAT WAY FOR ANOTHER DAY OR SO...AS A COUPLE OF UPPER DISTURBANCES CROSS THE GREAT BASIN AND NORTHERN ROCKIES. HI RES MODELS INCLUDING THE HRRR INDICATE THAT THE CURRENT ACTIVITY WILL CONTINUE WELL INTO THE NIGHT...WITH SOME SPILL OVER ACROSS THE I25 CORRIDOR THIS EVENING BETWEEN 22Z AND 06Z. OTHERWISE...FEEL THAT ACTIVITY WILL BE MAINLY TIED TO THE MTS. SO...NOT A LOT OF IMPRESSIVE STORMS JUST YET AND THE UPPER W-SW FLOW HAS BEEN KEEPING STORMS MOVING...CUTTING DOWN ON THE FLASH FLOOD THREAT. PRECIPITABLE WATER AMOUNTS SOUTH OF THE STATE LINE IN NM ARE WELL OVER AN INCH...BUT UP NORTH IN THE PUB CWA ARE CLOSER TO .6 TO .7 OF AN INCH. OF COURSE...THE THREAT OF FLASH FLOODING FOR AREA BURN SCARS REMAINS THIS EVE AND WILL HAVE TO BE MONITORED. TOMORROW...THE ACTIVE PATTERN CONTINUES AS A SHORTWAVE CROSSES WY...PROVIDING THE TRIGGER FOR A RAPID INCREASE IN CONVECTION OVER ALL OF THE MTS AND ADJACENT PLAINS BY 15Z. AS THIS WAVE CONTINUE EAST...THE BAND OF ENHANCED LIFT WILL CROSS THE I25 CORRIDOR AND E PLAINS THROUGH THE AFTN HRS...AND AN ATTEMPT HAS BEEN MADE IN THE POP GRIDS TO SHOW THIS. STRONG TO SEVERE STORMS WILL ALSO BE A POSSIBILITY TOMORROW AFTN AS THIS WAVE CROSSES THE AREA...AS THERE WILL BE PLENTY OF MOISTURE AND SHEAR ON TAP...AND SPC HAS PAINTED MUCH OF THE E PLAINS IN THE MARGINAL AREA. MAX TEMPS TOMORROW MAY BE A DEGREE OR TWO COOLER...BUT SHOULD STILL WARM INTO THE 70S AND 80S FOR THE PLAINS...60S AND 70S FOR THE HIGH VALLEYS. MOORE .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 243 PM MDT MON JUL 20 2015 TUESDAY NIGHT... AN AREA OF SHOWERS AND STORMS WILL LIKELY BE MOVING ACROSS THE EASTERN PLAINS AS A DISTURBANCE OVER THE REGION CONTINUES TO MOVE EAST. LOCALLY HEAVY RAIN WILL BE POSSIBLE AND STRONG TO MARGINALLY SVR STORMS WILL BE POSSIBLE GIVEN THE MODEST CAPE AND SHEAR THAT WILL BE OVER THE PLAINS. WEDNESDAY THROUGH FRIDAY... OVERALL IT WILL BE DRY AND WARM AS MONSOON TAP WILL BE DECREASED AS HEIGHTS RISE ACROSS THE REGION. MAX TEMPS OVER THE PLAINS WILL RISE BACK UP INTO THE 90S. WE WILL STILL SEE SOME ISOLD TSRA ACROSS THE REGION...BUT OVERALL COVERAGE WILL BE LESS THAN THE LAST FEW DAYS. SATURDAY INTO MONDAY.. GUIDANCE INDICATES MONSOON MOISTURE WILL ONCE AGAIN BE ON THE UPSWING AS SW FLOW CONTINUES ALOFT AND A TROUGH TO OUR WEST MOVES TOWARDS THE REGION. TEMPS WILL COOL SLIGHTLY AND SHOWERS AND STORMS SHOULD INCREASE DURING THE AFTERNOON AND EVENING TIME PERIODS. /HODANISH && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1116 PM MDT MON JUL 20 2015 MAIN CONCERNS WILL BE LOW CIG POTENTIAL OVER THE NEXT 24 HOURS...PARTICULARLY AT KCOS. WIDESPREAD PRECIP IS EXPECTED AS AN UPPER LEVEL SYSTEM MOVES THROUGH IN COINCIDENCE WITH THE MONSOONAL PATTERN OVER SE CO. COULD SEE A PERIOD OF MVFR CIGS AND POSSIBLY BRIEF IFR CONDITIONS OVER THE SERN PLAINS LATE TONIGHT THROUGH THE FIRST HALF OF TUE MORNING. PARTIAL CLEARING WILL BE POSSIBLE LATE IN THE MORNING AND EARLY AFTERNOON. THE CONCERN THEN SHIFTS TO THE POTENTIAL FOR TS ALONG WITH HEAVY RAIN...HAIL...AND GUSTY WINDS IN THE MID-LATE AFTERNOON THROUGH EARLY EVENING. SHOWERS AND STORMS WILL SLOWLY TRANSLATE EASTWARD INTO KS TUE EVENING. DEPENDING ON THE EXTENT OF PRECIP DURING THE DAY AND EVENING...COULD THEN SEE A PERIOD OF IFR CIGS AND/OR VIS TUE NIGHT INTO WED MORNING OVER THE ERN PLAINS. KALS SHOULD STAY VFR BUT COULD SEE SOME BRIEF RESTRICTIONS DUE TO ISOLD SHOWERS OR STORMS...ESPECIALLY LATE TUE MORNING THROUGH AFTERNOON. ROSE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ROSE SHORT TERM...MOORE LONG TERM...HODANISH AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS ALBANY NY
1036 PM EDT WED JUL 22 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE GREAT LAKES AND OHIO VALLEY OVERNIGHT THROUGH FRIDAY. COOLER AND LESS HUMID AIR WILL REMAIN IN PLACE FOR THE REST OF THE WEEK. AT THE SAME TIME...AN UPPER LEVEL WEATHER DISTURBANCE WILL DROP FROM QUEBEC INTO THE CANADIAN MARITIMES THURSDAY INTO FRIDAY...BRINGING SOME CLOUDS...AND ISOLATED TO SCATTERED SHOWERS...MAINLY FOR AREAS NORTH OF INTERSTATE 90. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 1036 PM...CLOUDS AND A FEW LIGHT SHOWERS LINGER ACROSS THE SOUTHERN ADIRONDACKS...LAKE GEORGE AREA AND SOUTHERN VERMONT. LATEST HRRR SHOWS THE LIGHT SHOWERS CONTINUING ALMOST THROUGH THE NIGHT BEFORE ENDING CLOSE TO SUNRISE. ADJUSTED GRIDS TO KEEP CLOUDS/POPS/WX ACROSS THAT SAME AREA AS SATELLITE LOOP SHOWS LITTLE CHANGE IN AREAL EXTENT OF CLOUD COVER. SLIGHT ADJUSTMENT TO TEMPS AS WELL BASED ON CURRENT CONDITIONS. OVERNIGHT...WITH DIMINISHING WINDS...TEMPS SHOULD COOL OFF QUITE NICELY...WITH WIDESPREAD 50S EXPECTED...ALONG WITH SOME 40S ACROSS PORTIONS OF THE SOUTHERN ADIRONDACKS AND SOUTHERN VT. PATCHY FOG WILL BE POSSIBLE WITHIN CLOSE PROXIMITY TO BODIES OF WATER TOWARD SUNRISE...AND MAY EXPAND BRIEFLY IN SOME RIVER VALLEYS...ESP ACROSS THE UPPER HUDSON VALLEY...SOUTHERN VT AND WESTERN MA. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... THU...ANOTHER NICE MID SUMMER DAY IS EXPECTED...WITH COMFORTABLE LEVELS OF HUMIDITY. UPPER LEVEL CYCLONIC FLOW AND SOME EMBEDDED UPPER LEVEL IMPULSES COULD BRING SOME CLOUDS...AND ISOLATED SHOWERS TO PORTIONS OF THE SOUTHERN ADIRONDACKS/SOUTHERN VT/UPPER HUDSON RIVER VALLEY...MAINLY IN THE AFTERNOON. MAX TEMPS SHOULD REACH THE UPPER 70S TO LOWER 80S IN VALLEYS...WARMEST ACROSS THE MID HUDSON RIVER VALLEY...WITH 60S TO LOWER/MID 70S ACROSS HIGHER ELEVATIONS. HOWEVER...THE COMBINATION OF COLD AIR ALOFT...MORE CLOUDS AND PERHAPS SOME PASSING SHOWERS MAY KEEP SOME OF THE HIGHEST PEAKS OF THE SOUTHERN ADIRONDACKS AND SOUTHERN VT ONLY IN THE UPPER 50S TO MID 60S. IT WILL BE BREEZY AT TIMES IN THE AFTERNOON...AS DEEP MIXING DEVELOPS...WITH SOME WIND GUSTS OF 25-30 MPH POSSIBLE IN THE AFTERNOON...ESPECIALLY IN CLOSE PROXIMITY TO THE MOHAWK RIVER VALLEY/CAPITAL REGION AND BERKSHIRES. THU NT...AFTER ANY ISOLATED EVENING SHOWERS ACROSS NORTHERN AREAS...ANOTHER MOSTLY CLEAR AND COOL NIGHT IS EXPECTED...WITH LOWS ONCE AGAIN IN THE 50S FOR MOST AREAS...AND SOME 40S ACROSS PORTIONS OF THE SOUTHERN ADIRONDACKS/SOUTHERN VT/NW MA. PATCHY FOG WILL BE POSSIBLE...ESP IN CLOSE PROXIMITY TO BODIES OF WATER. FRIDAY...STILL LOOKS LIKE THE BEST CHANCE FOR ISOLATED TO SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM...AS A PIECE THE UPPER LEVEL LOW CENTER ACROSS SE CANADA IS FORECAST TO DROP SOUTHWARD INTO NEW ENGLAND DURING THE DAY FRIDAY. THIS COLD CORE ALOFT IS UNSEASONABLY COLD FOR THIS TIME OF YEAR...WITH 500 MB HEIGHT ANOMALIES APPROACHING -2 TO -3 STDEV /FROM GEFS/ IN THE CORE AND 500 MB TEMPS OF -15C BRUSHING THE EASTERN HALF OF OUR AREA. ASSUMING DAYTIME HEATING CAN BUILD ENOUGH INSTABILITY...ISOLATED/SCATTERED LOW- TOPPED CONVECTION COULD DEVELOP ACROSS THE NORTHEASTERN 2/3 OF THE AREA FRIDAY AFTERNOON. THERE REMAIN SOME MODEL DIFFERENCES IN WHERE THE CORE OF THE UPPER LOW WILL TRACK...WITH MOST MODELS SUGGESTING IT TRACKS NEAR OR JUST E OF MAINE. DEPENDING ON HOW FAR WEST THIS CORE TRACKS COULD HAVE IMPLICATIONS ON COVERAGE AND INTENSITY OF CONVECTION. FOR NOW WILL MENTION ISOLATED TO SCATTERED SHOWERS WITH ISOLATED THUNDER...HIGHEST ACROSS THE NE 2/3 OF THE REGION...BUT WILL MONITOR TRENDS FOR POSSIBLE SMALL HAIL/GUSTY WINDS ESPECIALLY IF THE COLD CORE TRACKS CLOSER TO THE AREA AND STEEP LOW TO MID LEVEL LAPSE RATES DEVELOP. FRI MAX TEMPS SHOULD REACH THE MID 70S TO LOWER 80S IN VALLEYS...AND 60S TO MID 70S ACROSS HIGHER TERRAIN. FRIDAY NIGHT-SATURDAY...HIGH PRESSURE WILL BUILD ACROSS FRI NT...AND THEN MOVE OFF THE NEW ENGLAND COAST SAT. THIS SHOULD BRING FAIR WEATHER THROUGH AT LEAST EARLY SATURDAY AFTERNOON. HOWEVER...STRENGTHENING MID LEVEL WARM ADVECTION AND A DEVELOPING RETURN LOW LEVEL SOUTHERLY FLOW WILL ALLOW CLOUDS TO INCREASE SAT AFTERNOON...AND COULD ALLOW FOR SOME SHOWERS TO REACH AT LEAST THE WESTERN ADIRONDACKS BY SUNSET. WILL INDICATE SLIGHT CHC POPS FOR EXTREME NW AREAS FOR LATE SAT AFTERNOON...AND TRENDS WILL NEED TO BE WATCHED IN CASE SHOWERS EXPAND E AND S ANY QUICKER THAN CURRENT MODELS SUGGEST. FRI NT/SAT AM MINS SHOULD ONCE AGAIN FALL INTO THE 50S FOR MOST AREAS...WITH SAT MAX TEMPS REACHING THE LOWER/MID 80S IN VALLEYS...AND 75-80 ACROSS MOST HIGHER ELEVATIONS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS WE HEAD TOWARD THE END OF JULY...THE SYNOPTIC PATTERN APPEARS TO TRANSITION INTO MORE TROUGHINESS ACROSS THE NORTHEAST CORRIDOR. THE LAST HALF OF THE WEEKEND MAY BECOME A LITTLE ACTIVE AS THE PASSAGE OF THE WARM FRONT OCCURS SATURDAY NIGHT WITH THE APPROACH OF THE COLD FRONT SUNDAY. THE MAIN LOW WILL BE ACROSS HUDSON/GEORGIAN BAY WHICH WILL BE CULPRIT FOR OUR TRANSITION INTO NEXT WEEK. SO FOR THE LAST HALF OF THE WEEKEND...CHANCE FOR SHOWERS AND THUNDERSTORMS WITH WARM AND HUMID CONDITIONS AS H850 TEMPS ARE EXPECTED TO BE WELL INTO THE TEENS WHICH SHOULD ALLOW FOR SURFACE TEMPERATURES INTO THE UPPER 70S AND LOWER 80S AND LOWS IN THE 60S. MONDAY INTO TUESDAY...THE UPPER LEVEL TROUGH AXIS WILL LINGER INTO EARLY NEXT WEEK...YET THE 12Z ECMWF NOW WANTS TO EXIT THIS TROUGH RATHER QUICKLY AND REPLACE WITH RIDGE ON TUESDAY. THIS WILL ALL HAVE TO DO WITH THE TIMING DEPARTURE OF THE HUDSON/GEORGIAN BAY LOW. PER COLLABORATION WITH WPC...WE WILL FOLLOW MORE OF A FLAT SURFACE RIDGE WITH ONLY A SLIGHT CHANCE FOR CONVECTION ON MONDAY AND DRIER CONDITIONS ON TUESDAY. SEASONABLE TO ABOVE SEASONABLE TEMPERATURES ARE EXPECTED WITH MAINLY 80S FOR HIGHS AND OVERNIGHT LOWS INTO UPPER 50S AND MIDDLE 60S. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... AN UPPER LEVEL LOW WILL CONTINUE TO BE SITUATED OVER QUEBEC WITH CYCLONIC FLOW PERSISTING THIS EVENING INTO TOMORROW. WEAK DISTURBANCES WILL CONTINUE TO ROTATE AROUND THE UPPER LEVEL LOW. SFC HIGH PRESSURE WILL BE RIDGING IN FROM THE OHIO VALLEY. EXPECT VFR CONDITIONS PREDOMINATELY THE NEXT 24 HOURS AT KGFL/KALB/KPOU/KGFL. SOME SCT-BKN LOW AND MIDLEVEL CLOUDINESS WILL LINGER THIS EVENING AT KGFL DUE TO THE COLD POOL WITH THE UPPER LEVEL LOW AND WEAK DISTURBANCES ROTATING THROUGH IT. THE INSTABILITY STRATOCU/CU WILL DIMINISH TOWARDS SUNSET WITH THE LOSS OF THE DIURNAL HEATING. THE SKIES WILL BE MAINLY CLEAR TONIGHT...ESPECIALLY FROM KALB SOUTH...WITH A FEW-SCT STRATOCUMULUS/MID LEVEL CLOUDS NEAR KGFL/KPSF. THE BOUNDARY LAYER WILL BE WELL MIXED...SO THE POTENTIAL MIST/FOG THREAT LOOKS LOW. THE ONLY LOCATION WHERE A BRIEF PERIOD OF MVFR MIST WAS PLACED IN THE TAF FROM 08Z-12Z WAS AT KPSF. THERE MAY BE SOME SHALLOW RADIATIONAL MIST/FOG OVER THE NARROW BODIES OF WATER IN THE FCST AREA IF THE WINDS GO CALM. EXPECT SOME DIURNAL LOW CLOUDS TO FORM AGAIN LATE TOMORROW MORNING INTO THE AFTERNOON...BUT CONTINUED VFR CONDITIONS. W/NW WINDS WILL DIMINISH BTWN 00Z-04Z TO 5-10 KTS...AND THEN BECOME LIGHT TO CALM OVERNIGHT. EXPECT W TO NW WINDS TO INCREASE LATE TOMORROW MORNING TO 5-10 KTS WITH GUSTS TO 25KTS DURING THE AFTERNOON. OUTLOOK... THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. CHANCE OF SHRA. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. && .FIRE WEATHER... HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE GREAT LAKES AND OHIO VALLEY OVERNIGHT THROUGH FRIDAY. COOLER AND LESS HUMID AIR WILL REMAIN IN PLACE FOR THE REST OF THE WEEK. AT THE SAME TIME...AN UPPER LEVEL WEATHER DISTURBANCE WILL DROP FROM QUEBEC INTO THE CANADIAN MARITIMES THURSDAY INTO FRIDAY...BRINGING SOME CLOUDS...AND ISOLATED TO SCATTERED SHOWERS...MAINLY FOR AREAS NORTH OF INTERSTATE 90. MAXIMUM RH VALUES SHOULD RECOVER TO 85-100 PERCENT TONIGHT...WITH WIDESPREAD DEW FORMATION LIKELY. THE RH SHOULD FALL TO MIN VALUES OF 35-50 PERCENT THURSDAY AFTERNOON...THEN RECOVER TO 80-100 PERCENT FOR THU NT. WEST/NORTHWEST WINDS OF 10-20 MPH WILL DIMINISH TO LESS THAN 10 MPH OVERNIGHT...THEN INCREASE TO 10-20 MPH AGAIN LATE THURSDAY MORNING INTO THE AFTERNOON...WITH SOME GUSTS OF 25-30 MPH POSSIBLE. && .HYDROLOGY... MAINLY DRY WEATHER IS EXPECTED FROM THROUGH THURSDAY NIGHT. THE EXCEPTION WILL BE A FEW LIGHT SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS AND HIGHER TERRAIN OF VERMONT. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE ACROSS MUCH OF THE REGION ON FRIDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN TO THE REGION SATURDAY NIGHT INTO MONDAY WITH LOCALLY HEAVY RAINFALL POSSIBLE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL/JPV NEAR TERM...SND/KL SHORT TERM...KL/JPV LONG TERM...BGM AVIATION...SND FIRE WEATHER...KL/JPV HYDROLOGY...KL/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
141 PM EDT TUE JUL 21 2015 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM EDT...A STATIONARY BOUNDARY WAS DRAPED ACROSS LONG ISLAND WITH A WAVE OF LOW PRESSURE OVER CAPE COD. THIS HAS RESULTED IN CLOUD COVER ACROSS THE FAR SE PTN OF THE FA. MEANWHILE A STRONG COLD FRONT WAS MOVING SOUTHEAST FROM FAR NRN AND CNTRL NY. THE MAIN FOCUS FOR THIS AFT INTO ERLY THIS EVENG CONTS TO BE THE CHANCES FOR SHOWERS AND THUNDERSTORMS AHEAD OF THE COLD FRONT. THE HRRR COL MAX REFLECTIVITY HAS THE CURRENT LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS ANALYZED WELL. PRECIP HAS ALREADY ARRIVED ACROSS FAR NW PTN OF THE FA AND REACHES THE GREATER CAPITAL DISTRICT BTWN 3 AND 4 PM. AT THAT TIME FRONT WEAKENS SOMEWHAT AND PRECIPITATION BECOMES MORE DIFFUSE. MEANWHILE...SOME INDICATIONS OF STRONGER TSRA DEVELOPING ALONG OCCLUDED FRONT/TROUGH ACROSS SOUTHERN CWA TOWARD THIS TIME. HAVE ATTEMPTED TO TIME THE PRECIP INTO AND THROUGH THE CWA IN THE GRIDS /WITH LIKELY POPS/ RELYING ON HRRR. AS FAR AS SEVERE CHANCES GO...SPC HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS ACRS OUR CWA. THIS STILL LOOKS APPROPRIATE. FAIRLY ANEMIC THERMODYNAMIC PARAMETERS ON 12Z ALY SOUNDING. HOWEVER...BUF SOUNDING SHOWING BETTER INSTABILITY. 0-6KM SHEAR RESPECTABLE AT ALY WITH 38 KNOTS NOTED. WEAKER AT BUF. MID LEVEL LAPSE RATES NOT PARTICULARLY IMPRESSIVE EITHER. VIS SATELLITE REVEALS QUITE A BIT OF SUNSHINE NOW ACROSS MARGINAL RISK AREA. WE WILL BE KEEPING A CLOSE EYE ON MESOSCALE ANALYSIS AND THE RADAR THIS AFTERNOON. TEMPERATURES WILL STILL BE VERY WARM AHEAD OF THE FRONT...WITH MID TO UPPER 80S EXPECTED FROM THE HUDSON VALLEY EASTWARD. AREAS NEAR POUGHKEEPSIE WILL LIKELY REACH 90 DEGREES FOR THE THIRD CONSECUTIVE DAY. SHOWERS AND STORMS WILL LIKELY DECREASE IN COVERAGE AFTER DARK DUE TO LOSS OF DAYTIME HEATING AND INSTABILITY...ALTHOUGH THE COLD FRONT WILL STILL BE MOVING THROUGH AREAS SOUTH AND EAST OF ALBANY...SO WILL MAINTAIN SLIGHT TO LOW CHANCE POPS INTO THE EVENING. ANY SHOWERS WILL DISSIPATE BY MIDNIGHT...WITH DRY CONDITIONS THROUGH THE REST OF THE OVERNIGHT HOURS AS NORTHWEST FLOW DEVELOPS BEHIND THE COLD FRONT. TEMPS BY EARLY WEDNESDAY MORNING WILL BE COOLER THAN RECENT NIGHTS WITH GENERALLY 50S TO LOWER 60S ACROSS THE REGION. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... GENERALLY AGREEMENT AMONG THE MDL SUITE THROUGH THIS PERIOD AS WX PATTERN OVER E NA WILL BE DOMINATED BY A 500 HPA TROF CUT OFF OVER QB...THAT DIVES SE INTO THE MARITIMES BY FRI. INITIALLY SFC HIGH PRESSURE BUILDS FM CENTRAL CANADA INTO THE UPPER GRT PLAINS WED...AS TUES SFC LOW AND CDFNT DEPART OFFSHORE. BY WED AFTN COOLING ALOFT AS 500HPA TEMPS FALL TO -13C TO -16C AND JETS MOVING AROUND BASE OF 500HPA CUT OFF SAGGING SOUTH INTO FCA BEGIN TO IMPACT RGN WITH VARYING DEGREES OF CLOUDS AND SCT MAINLY DIURNALLY DRIVEN -SHRA N TIER AND OVER HIR TRRN. WOULDN`T RULE OUT SOME GRAUPAL IN THESE -SHRA OVER HIR TRRN. THE NAM IS MORE AGGRESSIVE WITH THIS PATTERN INTO THE FCA BY WED AFTN...THE GFS HOLDING OFF TILL THU. BUT THE TREND IS STILL THE SAME. AT THE SAME TIME IN RESPONSE TO THE DIVING 500 HPA TROF...SFC LOW PRESSURE OVER MARITIMES DEEPENS...AND WIND GRADIENT INCRG OVR RGN ESPECIALLY IN THE AFTN...RESULTING IN BREEZY CONDS AT TIMES. SO OVERALL A PERIOD OF PC TO AT TIMES MC SKIES N WITH SCT SHRA EACH DAY...DIURNALLY DRIVEN. GENERALLY MS SOUTH OF I90. TEMPS WILL BE 3-5 DEG BLO NORMALS...WITH VERY COMFORTABLE RH LEVELS AS TD FALL TO THE UPPER 40S AND 50S. FRIDAY NIGHT 500 HPA TROF FINALLY SLIDES OFFSHORE AS SFC HIGH SETTLES OVER NE USA INTO QB. && .LONG TERM /SATURDAY THROUGH MONDAY/... ECMWF/GFS/HPC PRETTY MUCH IN AGREEMENT. SATURDAY BRINGS A 500 HPA RIDGE INTO THE REGION AS SFC HIGH SLIDES OFFSHORE. FOR THE MOST PART IT SHOULD BE A DRY DAY WITH TEMPS NR TO SLIGHTLY BLO NORMAL. AFT SAT THE REST OF THE EFP WILL BE AN UNSETTLED PERIOD. AS THE 500HPA RIDGE MOVES EAST OF RGN SAT NIGHT CLOUDS INCR. AT THE SFC A WMFNT PUSHES TO ABOUT CLE- ORF...AND RESULT IS INCG CHC SHRA/TSTMS SAT NT...AND A THREAT OF SHRA/TSTMS INTO MON. BY SUN MRNG THE 500HPA RIDGE IS OFFSHORE...AND THE 500HPA FLOW HAS BCM NW. THIS LEAVES THE SFC HIGH OFFSHORE...WEAK WAA OVER FCA...AND THE WMFNT ONLY MVNG SLIGHTLY NE THROUGH MON. COMBINATION OF CONVECTIVE DEBRIS...AND SOME MID LEVEL DRYING WILL RESULT IN VRBL CLOUDS AND MAYBE SOME SUNNY PERIODS SUN AND MON. DIURNALLY DRIVEN ROUNDS OF -SHRA/TSTMS WILL AGAIN BE POSSIBLE SUN AND AGAIN MON. TEMPS WILL REMAIN NR TO SLIGHTLY BLO NORMALS...BUT TD WILL CREEP SLOWLY UP THROUGH THE 50S AND RETURN TO THE 60S BY MON. WILL POPULATE WITH HPC GUID. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... A COLD FRONT WILL MOVE ACROSS ERN NY AND WRN NEW ENGLAND THIS AFTERNOON INTO THE EARLY EVENING. AN UPPER LEVEL LOW WILL BE NORTH OF THE REGION OVERNIGHT INTO TOMORROW WITH BREEZY AND COOLER CONDITIONS AND THE BEST CHANCE OF SHOWERS NORTH OF THE MOHAWK VALLEY AND CAPITAL REGION. A COLD FRONT CONTINUES TO MAKE STEADY PROGRESS ACROSS NRN-CNTRL NY EARLY THIS AFTERNOON. VARIABLE MID AND HIGH CLOUDINESS CONTINUES TO BE MOVING INTO THE TERMINALS AHEAD OF THE COLD FRONT...AND DUE TO A WEAK SFC WAVE THAT MOVED CLOSE TO THE NEW ENGLAND COASTLINE THIS MORNING. THE BEST CHC OF SHOWERS AND ISOLD THUNDERSTORMS WILL BE BETWEEN 20Z-23Z FOR KALB/KPSF/KGFL. CONFIDENCE WAS NOT GREAT ENOUGH FOR PLACING A THUNDERSTORM IN THE FCST AT THIS POINT DUE TO THE LIMITED INSTABILITY IN PLACE. A TEMPO GROUP WAS USED FOR MVFR VSBYS/CIGS WITH THE SHOWERS. THE BEST CHC OF A THUNDERSTORM WILL BE NEAR KPOU WHERE THERE IS A BIT MORE INSTABILITY...AND THE COLD FRONT AND SFC TROUGH NEED TO CLEAR THE REGION. A BRIEF TEMPO GROUP FROM 22Z/TUE TO 00Z/WED WAS PLACED IN THE KPOU TAF. THE SKIES SHOULD QUICKLY CLEAR IN THE WAKE OF THE FRONT BTWN 23Z/TUE TO 02Z/WED DUE TO THE STRONG SUBSIDENCE. VFR CONDITIONS SHOULD BE PREVAIL MOST OF THE NIGHT...EXCEPT AT KGFL/KPSF WHERE SOME PATCHY MIST MAY FORM. FOR NOW...SOME MVFR VSBYS WERE PLACED IN BTWN 08Z-13Z/WED...BUT IF THE LOW-LEVEL SFC WINDS STAY UP...THEN MIST/FOG IS NOT LIKELY. LATER TAFS WILL ADDRESS IFR/LIFR FOG POSSIBILITIES IF CONFIDENCE IS GREATER. THE WINDS WILL BE FROM THE S/SW TO WEST AT 7-12 KTS AHEAD OF THE FRONT...AND THEN VEER TO THE W/NW AT 8-12 KTS BTWN 20Z/TUE- 00Z/WED BEHIND THE COLD FRONT. THE WINDS WILL LIGHTEN TO 7 KTS OR LESS AFTER MIDNIGHT. EXPECT W TO NW WINDS AT 5-10 KTS LATE TOMORROW MORNING INTO THE AFTERNOON. OUTLOOK... WEDNESDAY NIGHT TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... A STRONG COLD FRONT WILL CROSS THE REGION TODAY...BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90. RELATIVE HUMIDITY VALUES WILL INCREASE TO MAXIMUM VALUES OF 80 TO 100 PERCENT TONIGHT AND WEDNESDAY NIGHT. MINIMUM VALUES THIS AFTERNOON WILL BE 35 TO 65 PERCENT...AND 35 TO 55 PERCENT WEDNESDAY AFTERNOON. WINDS WILL BECOME SOUTHWEST AND INCREASE TO AROUND 10 TO 15 MPH TODAY. TONIGHT THEY WILL BECOME WEST AROUND 5 MPH AND INCREASE TO 10 TO 15 MPH WEDNESDAY. && .HYDROLOGY... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY ASSOCIATED WITH THE PASSAGE OF A COLD FRONT. LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF WATER IN URBAN AND POOR DRAINAGE LOCATIONS. MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY EXCEPT FOR A FEW LIGHT SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS AND HIGHER TERRAIN OF VERMONT EACH DAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL RETURN TO THE REGION SUNDAY INTO MONDAY WITH LOCALLY HEAVY DOWNPOURS POSSIBLE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...OKEEFE/11/JPV SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...WASULA FIRE WEATHER...SNYDER HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
1243 PM EDT TUE JUL 21 2015 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM EDT...A STATIONARY BOUNDARY WAS DRAPED ACROSS LONG ISLAND WITH A WAVE OF LOW PRESSURE OVER CAPE COD. THIS HAS RESULTED IN CLOUD COVER ACROSS THE FAR SE PTN OF THE FA. MEANWHILE A STRONG COLD FRONT WAS MOVING SOUTHEAST FROM FAR NRN AND CNTRL NY. THE MAIN FOCUS FOR THIS AFT INTO ERLY THIS EVENG CONTS TO BE THE CHANCES FOR SHOWERS AND THUNDERSTORMS AHEAD OF THE COLD FRONT. THE HRRR COL MAX REFLECTIVITY HAS THE CURRENT LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS ANALYZED WELL. PRECIP HAS ALREADY ARRIVED ACROSS FAR NW PTN OF THE FA AND REACHES THE GREATER CAPITAL DISTRICT BTWN 3 AND 4 PM. AT THAT TIME FRONT WEAKENS SOMEWHAT AND PRECIPITATION BECOMES MORE DIFFUSE. MEANWHILE...SOME INDICATIONS OF STRONGER TSRA DEVELOPING ALONG OCCLUDED FRONT/TROUGH ACROSS SOUTHERN CWA TOWARD THIS TIME. HAVE ATTEMPTED TO TIME THE PRECIP INTO AND THROUGH THE CWA IN THE GRIDS /WITH LIKELY POPS/ RELYING ON HRRR. AS FAR AS SEVERE CHANCES GO...SPC HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS ACRS OUR CWA. THIS STILL LOOKS APPROPRIATE. FAIRLY ANEMIC THERMODYNAMIC PARAMETERS ON 12Z ALY SOUNDING. HOWEVER...BUF SOUNDING SHOWING BETTER INSTABILITY. 0-6KM SHEAR RESPECTABLE AT ALY WITH 38 KNOTS NOTED. WEAKER AT BUF. MID LEVEL LAPSE RATES NOT PARTICULARLY IMPRESSIVE EITHER. VIS SATELLITE REVEALS QUITE A BIT OF SUNSHINE NOW ACROSS MARGINAL RISK AREA. WE WILL BE KEEPING A CLOSE EYE ON MESOSCALE ANALYSIS AND THE RADAR THIS AFTERNOON. TEMPERATURES WILL STILL BE VERY WARM AHEAD OF THE FRONT...WITH MID TO UPPER 80S EXPECTED FROM THE HUDSON VALLEY EASTWARD. AREAS NEAR POUGHKEEPSIE WILL LIKELY REACH 90 DEGREES FOR THE THIRD CONSECUTIVE DAY. SHOWERS AND STORMS WILL LIKELY DECREASE IN COVERAGE AFTER DARK DUE TO LOSS OF DAYTIME HEATING AND INSTABILITY...ALTHOUGH THE COLD FRONT WILL STILL BE MOVING THROUGH AREAS SOUTH AND EAST OF ALBANY...SO WILL MAINTAIN SLIGHT TO LOW CHANCE POPS INTO THE EVENING. ANY SHOWERS WILL DISSIPATE BY MIDNIGHT...WITH DRY CONDITIONS THROUGH THE REST OF THE OVERNIGHT HOURS AS NORTHWEST FLOW DEVELOPS BEHIND THE COLD FRONT. TEMPS BY EARLY WEDNESDAY MORNING WILL BE COOLER THAN RECENT NIGHTS WITH GENERALLY 50S TO LOWER 60S ACROSS THE REGION. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... GENERALLY AGREEMENT AMONG THE MDL SUITE THROUGH THIS PERIOD AS WX PATTERN OVER E NA WILL BE DOMINATED BY A 500 HPA TROF CUT OFF OVER QB...THAT DIVES SE INTO THE MARITIMES BY FRI. INITIALLY SFC HIGH PRESSURE BUILDS FM CENTRAL CANADA INTO THE UPPER GRT PLAINS WED...AS TUES SFC LOW AND CDFNT DEPART OFFSHORE. BY WED AFTN COOLING ALOFT AS 500HPA TEMPS FALL TO -13C TO -16C AND JETS MOVING AROUND BASE OF 500HPA CUT OFF SAGGING SOUTH INTO FCA BEGIN TO IMPACT RGN WITH VARYING DEGREES OF CLOUDS AND SCT MAINLY DIURNALLY DRIVEN -SHRA N TIER AND OVER HIR TRRN. WOULDN`T RULE OUT SOME GRAUPAL IN THESE -SHRA OVER HIR TRRN. THE NAM IS MORE AGGRESSIVE WITH THIS PATTERN INTO THE FCA BY WED AFTN...THE GFS HOLDING OFF TILL THU. BUT THE TREND IS STILL THE SAME. AT THE SAME TIME IN RESPONSE TO THE DIVING 500 HPA TROF...SFC LOW PRESSURE OVER MARITIMES DEEPENS...AND WIND GRADIENT INCRG OVR RGN ESPECIALLY IN THE AFTN...RESULTING IN BREEZY CONDS AT TIMES. SO OVERALL A PERIOD OF PC TO AT TIMES MC SKIES N WITH SCT SHRA EACH DAY...DIURNALLY DRIVEN. GENERALLY MS SOUTH OF I90. TEMPS WILL BE 3-5 DEG BLO NORMALS...WITH VERY COMFORTABLE RH LEVELS AS TD FALL TO THE UPPER 40S AND 50S. FRIDAY NIGHT 500 HPA TROF FINALLY SLIDES OFFSHORE AS SFC HIGH SETTLES OVER NE USA INTO QB. && .LONG TERM /SATURDAY THROUGH MONDAY/... ECMWF/GFS/HPC PRETTY MUCH IN AGREEMENT. SATURDAY BRINGS A 500 HPA RIDGE INTO THE REGION AS SFC HIGH SLIDES OFFSHORE. FOR THE MOST PART IT SHOULD BE A DRY DAY WITH TEMPS NR TO SLIGHTLY BLO NORMAL. AFT SAT THE REST OF THE EFP WILL BE AN UNSETTLED PERIOD. AS THE 500HPA RIDGE MOVES EAST OF RGN SAT NIGHT CLOUDS INCR. AT THE SFC A WMFNT PUSHES TO ABOUT CLE- ORF...AND RESULT IS INCG CHC SHRA/TSTMS SAT NT...AND A THREAT OF SHRA/TSTMS INTO MON. BY SUN MRNG THE 500HPA RIDGE IS OFFSHORE...AND THE 500HPA FLOW HAS BCM NW. THIS LEAVES THE SFC HIGH OFFSHORE...WEAK WAA OVER FCA...AND THE WMFNT ONLY MVNG SLIGHTLY NE THROUGH MON. COMBINATION OF CONVECTIVE DEBRIS...AND SOME MID LEVEL DRYING WILL RESULT IN VRBL CLOUDS AND MAYBE SOME SUNNY PERIODS SUN AND MON. DIURNALLY DRIVEN ROUNDS OF -SHRA/TSTMS WILL AGAIN BE POSSIBLE SUN AND AGAIN MON. TEMPS WILL REMAIN NR TO SLIGHTLY BLO NORMALS...BUT TD WILL CREEP SLOWLY UP THROUGH THE 50S AND RETURN TO THE 60S BY MON. WILL POPULATE WITH HPC GUID. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SCT-BKN MID AND HIGH LEVEL CLOUDS ACROSS THE REGION THIS MORNING WITH PREVAILING VFR CONDITIONS. A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL MOVE INTO THE REGION LATE IN THE DAY...TRIGGERING MAINLY SCATTERED SHRA/TSRA. WILL MENTION PROB30 FOR TSRA FROM LATE AFTERNOON INTO EARLY EVENING AT KALB/KGFL/KPSF BUT ONLY VCSH AT KPOU SINCE COVERAGE SHOULD BE ONLY ISOLATED THERE. BRIEF MVFR OR IFR WILL BE POSSIBLE WITHIN ANY SHRA/TSRA. WINDS WILL INITIALLY BE LIGHT AND VARIABLE...BECOMING SOUTH TO SOUTHWEST AROUND 5-10 KTS DURING THE DAY. WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE COLD FRONT THIS EVENING. OUTLOOK... WEDNESDAY NIGHT TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... A STRONG COLD FRONT WILL CROSS THE REGION TODAY...BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90. RELATIVE HUMIDITY VALUES WILL INCREASE TO MAXIMUM VALUES OF 80 TO 100 PERCENT TONIGHT AND WEDNESDAY NIGHT. MINIMUM VALUES THIS AFTERNOON WILL BE 35 TO 65 PERCENT...AND 35 TO 55 PERCENT WEDNESDAY AFTERNOON. WINDS WILL BECOME SOUTHWEST AND INCREASE TO AROUND 10 TO 15 MPH TODAY. TONIGHT THEY WILL BECOME WEST AROUND 5 MPH AND INCREASE TO 10 TO 15 MPH WEDNESDAY. && .HYDROLOGY... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY ASSOCIATED WITH THE PASSAGE OF A COLD FRONT. LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF WATER IN URBAN AND POOR DRAINAGE LOCATIONS. MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY EXCEPT FOR A FEW LIGHT SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS AND HIGHER TERRAIN OF VERMONT EACH DAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL RETURN TO THE REGION SUNDAY INTO MONDAY WITH LOCALLY HEAVY DOWNPOURS POSSIBLE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...OKEEFE/11/JPV SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...JPV FIRE WEATHER...SNYDER HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
128 AM EDT TUE JUL 21 2015 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE REGION TODAY...BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1025 PM...MAINLY JUST HIGH CLOUDS ACROSS THE ALBANY FORECAST AREA AT THIS TIME. SOME LOWER CLOUDS ACROSS THE EXTREME SOUTH AS COLD FRONT/DEWPOINT BOUNDARY APPEARS TO HAVE HUNG UP JUST SOUTH OF POUGHKEEPSIE. THERE WERE A FEW SHOWERS VCNTY OF POUGHKEEPSIE AN HOUR AGO...BUT RADAR SHOWS THEY HAVE DISSIPATED. SHOWERS ASSOCIATED WITH COLD FRONT TO NORTHWEST ARE STILL NORTH AND WEST OF TORONTO. LATEST HRRR HAS NOTHING BUT A FEW SPRINKLES THROUGH 12Z SO NOT EXPECTING MUCH CHANGE THROUGH THE OVERNIGHT. THIS CDFNT WILL REACH LK ERI-ST LAWRENCE VLY BY MORNING...FOLLOWED BY A 500 HPA SHORT WV...AND CROSS THE FCA DURING THE DAY TUES. TD CLOSE TO 60 AND ONLY 400-800 J/KG CAPE...BEST LI -4 TO -6 WITH FOCUS ALONG W PERIPHERY OF FCA...ONLY SCT NON SEVERE TSTMS AND -SHRA ARE EXPECTED. SPC HAS AREA IN GEN TSTMS..NO SVR THREAT. OTRW TUES WILL BE A WARM DAY WITH HIGHS IN THE 80S AND A FEW NR 90 IN THE SOUTH...AS WELL AS SCT- BKN CU AHEAD OF THE CDFNT...CLOUDS WITH ITS PASSAGE AND CLEARING IN ITS WAKE. TUES EVNG THE CDFNT WILL PUSH S OF FCA AND 500HPA TROF MOVES ACROSS NY/NEW ENG OVRNT. SCT -SHRA/TSTMS WILL END IN THE EVNG SE. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/..... GENERALLY AGREEMENT AMONG THE MDL SUITE THROUGH THIS PERIOD AS WX PATTERN OVER E NA WILL BE DOMINATED BY A 500 HPA TROF CUT OFF OVER QB...THAT DIVES SE INTO THE MARITIMES BY FRI. INITIALLY SFC HIGH PRESSURE BUILDS FM CENTRAL CANADA INTO THE UPPER GRT PLAINS WED...AS TUES SFC LOW AND CDFNT DEPART OFFSHORE. BY WED AFTN COOLING ALOFT AS 500HPA TEMPS FALL TO -13C TO -16C AND JETS MOVING AROUND BASE OF 500HPA CUT OFF SAGGING SOUTH INTO FCA BEGIN TO IMPACT RGN WITH VARYING DEGREES OF CLOUDS AND SCT MAINLY DIURNALLY DRIVEN -SHRA N TIER AND OVER HIR TRRN. WOULDN`T RULE OUT SOME GRAUPAL IN THESE -SHRA OVER HIR TRRN. THE NAM IS MORE AGGRESSIVE WITH THIS PATTERN INTO THE FCA BY WED AFTN...THE GFS HOLDING OFF TILL THU. BUT THE TREND IS STILL THE SAME. AT THE SAME TIME IN RESPONSE TO THE DIVING 500 HPA TROF...SFC LOW PRESSURE OVER MARITIMES DEEPENS...AND WIND GRADIENT INCRG OVR RGN ESPECIALLY IN THE AFTN...RESULTING IN BREEZY CONDS AT TIMES. SO OVERALL A PERIOD OF PC TO AT TIMES MC SKIES N WITH SCT SHRA EACH DAY...DIURNALLY DRIVEN. GENERALLY MS SOUTH OF I90. TEMPS WILL BE 3-5 DEG BLO NORMALS...WITH VERY COMFORTABLE RH LEVELS AS TD FALL TO THE UPPER 40S AND 50S. FRIDAY NIGHT 500 HPA TROF FINALLY SLIDES OFFSHORE AS SFC HIGH SETTLES OVER NE USA INTO QB. && .LONG TERM /SATURDAY THROUGH MONDAY/... THIS FALL-LIKE AIRMASS...SLIGHTLY BELOW TEMPERATURES AND COMFORTABLE HUMIDITY LEVELS...WILL CONTINUE INTO SATURDAY AS AN AREA OF HIGH PRESSURE RIDGES ACROSS THE REGION. SATURDAY LOOKS TO BE THE NICEST DAY OF THE LONG TERM PERIOD WITH DRY WEATHER AND PARTLY CLOUDY SKIES. DRY WEATHER LOOKS TO CONTINUE INTO SATURDAY NIGHT...WHILE AN UPPER- LEVEL SHORTWAVE TROUGH APPROACHES FROM THE GREAT LAKES REGION. LONG RANGE GUIDANCE IS HAVING SOME DIFFICULTY RESOLVING THIS SHORTWAVE WITH IT BEING SO FAR OUT IN TIME...SO HAVE GONE WITH SLIGHT CHANCE AND CHANCE POPS IN THE FORECAST FOR SUNDAY AND INTO MONDAY. HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY CONTINUE 3 TO 5 DEG BLO NORMALS. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... MAINLY VFR CONDITIONS THROUGH THE 24 HOUR TAF CYCLE WITH TWO PERIODS WHERE MVFR CONDITIONS MAY DEVELOP FOR A SHORT TIME. AFTER ABOUT 09Z TONIGHT...SOME LOWER VISIBILITIES AND SCATTERED CLOUDS BELOW 1000 FEET MAY DEVELOP AT KGFL AND KPSF AND HAVE PLACED VSBYS AT 3SM IN THEIR RESPECTIVE TAFS. LATER TUESDAY AFTERNOON... SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD OF A COLD FRONT. FOR NOW JUST VCSH IN TAFS BUT WE WILL MONITOR FOR IFR CONDITIONS AND LIGHTNING. WEST TO NORTHWEST WINDS AT AROUND 10 KTS BECOMING LIGHT AND VARIABLE TO NEAR CALM TONIGHT. WINDS WILL BECOME SOUTH TO SOUTHWEST AT 5 TO 10 KTS TUESDAY. OUTLOOK... TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...FG...TSRA. WEDNESDAY THROUGH SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... HIGH PRESSURE WILL BUILD ACROSS THE REGION THIS AFTERNOON AND SLIDE OFFSHORE TONIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION ON TUESDAY...BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CANADA INTO THE GREAT LAKES WEDNESDAY...USHERING IN A COOLER AND DRIER AIR MASS INTO THE REGION FOR MID WEEK TO LATE WEEK. RELATIVE HUMIDITY VALUES WILL INCREASE TO MAXIMUM VALUES OF 80 TO 100 PERCENT TONIGHT AND TUESDAY NIGHT. MINIMUM VALUES TUESDAY AFTERNOON WILL BE 35 TO 65 PERCENT...AND 35 TO 55 PERCENT WEDNESDAY AFTERNOON. WINDS WILL BE LIGHT TONIGHT...AND BECOME SOUTHWEST AND INCREASE TO AROUND 10 TO 15 MPH TUESDAY. TUESDAY NIGHT THEY WILL BECOME WEST AROUND 5 MPH AND INCREASE TO 10 TO 15 MPH WEDNESDAY. && .HYDROLOGY... MAINLY DRY CONDITIONS ARE EXPECTED THROUGH THE WEEK WITH THE EXCEPTION OF SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY ASSOCIATED WITH A COLD FRONT. SOME LOCALLY HEAVY RAINFALL WILL BE POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF WATER IN URBAN AND POOR DRAINAGE LOCATIONS. MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY EXCEPT FOR A FEW LIGHT SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS EACH DAY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...SND/SNYDER SHORT TERM...SNYDER LONG TERM...IRL AVIATION...SND/11 FIRE WEATHER...SNYDER HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
356 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS OUR AREA TONIGHT, THEN HIGH PRESSURE BUILDS IN DURING WEDNESDAY. THIS HIGH PRESSURE SYSTEM IS FORECAST TO REMAIN IN PLACE THROUGH FRIDAY. HOWEVER, A WEAK COLD FRONT ARRIVES FROM THE NORTH FRIDAY THEN RETURNS NORTHWARD AS A WARM FRONT LATE SATURDAY. A POTENTIALLY WEAKENING COLD FRONT IS THEN FORECAST TO MOVE THROUGH OUR REGION LATE SUNDAY INTO MONDAY AS HIGH PRESSURE RETURNS FOR TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A LATE-DAY SURFACE ANALYSIS SHOWS A WEAK SURFACE TROUGH EXTENDING ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA, FROM SOUTHERN NJ AND INTO THE DELMARVA. THIS BOUNDARY IS PROVIDING A FOCUS FOR SCATTERED SHWR/TSTORM ACTIVITY, AND WE HAVE INCREASED POPS ACCORDINGLY TO HIGH CHANCE AND LOW LIKELY FOR THESE AREAS. ANY SHWRS/TSTORMS WILL HAVE THE POTENTIAL TO PRODUCE TORRENTIAL DOWNPOURS AS THERE IS AMPLE BOUNDARY LAYER MOISTURE, WITH PWATS REMAINING AROUND 2.0 INCHES AND SURFACE DEW POINTS HOLDING IN THE LOW 70S. WHILE WIDESPREAD STRONGER TO SEVERE STORMS ARE NOT EXPECTED, DEVELOPING STORMS IN THIS ENVIRONMENT COULD BRIEFLY PULSE UP AND PRODUCE STRONG WIND GUSTS TO THE SURFACE AS THERE IS ADEQUATE INSTABILITY AND SHEAR. ELSEWHERE, A COLD FRONT WILL CONTINUE TO APPROACH OUR REGION FROM THE NORTHWEST. AS THIS FRONT EDGES INTO NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA INTO THIS EVENING, SOME SCATTERED SHWRS AND TSTORMS MAY ACCOMPANY IT, ESPECIALLY INTO THE POCONOS, THE LEHIGH VALLEY, AND NORTHWEST NJ. THE OPPORTUNITY FOR SHWR/TSTORM ACTIVITY LOOKS TO BE RELATIVELY SHORT-LIVED, THOUGH, AS MOST MODEL GUIDANCE INCLUDING THE HRRR AND NAM12 TENDS TO SOMEWHAT WEAKEN THE INCOMING CONVECTION AS IT ENTERS AND MOVES THROUGH OUR NORTHWEST ZONES. AS MENTIONED ABOVE A FEW BRIEFLY STRONGER STORMS COULD ALSO PULSE-UP IN THESE AREAS, WITH GUSTY WINDS BEING THE MAIN CONCERN. THE COLD FRONT IS EXPECTED TO CROSS OUR REGION THROUGH THE LATE EVENING HOURS AND PASS OFFSHORE AROUND MIDNIGHT. ANY REMAINING SCATTERED SHWR/TSTORM ACTIVITY WILL QUICKLY TAPER OFF WITH THE PASSAGE OF THE FRONT, AND IN ITS WAKE, A DRIER AIRMASS WILL BEGIN TO OVERSPREAD THE REGION THROUGH THE OVERNIGHT. SKIES ARE ALSO EXPECTED TO CLEAR IN THE WAKE OF THE FRONT WITH A WIND SHIFT TO THE NORTHWEST. OVERNIGHT MINIMUM TEMPERATURES WILL BE MORE COMFORTABLE THAN RECENT NIGHTS, AS LOWS RANGE FROM THE UPPER 50S IN THE NORTH TO MOSTLY THE UPPER 60S ELSEWHERE. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... WITH THE PREVIOUSLY MENTIONED COLD FRONT MOVING FARTHER OFFSHORE THROUGH THE DAYTIME WEDNESDAY, INCOMING HIGH PRESSURE CENTERED OVER THE GREAT LAKES AND MIDWEST STATES WILL GRADUALLY BE BUILDING EASTWARD TOWARD OUR REGION. A NOTICEABLY COOLER AND DRIER AIRMASS WILL CONTINUE TO OVERSPREAD THE REGION ON WEST-NORTHWEST WINDS. AMPLE SUNSHINE IS ANTICIPATED THROUGH THE DAY, WITH PERHAPS A FEW AFTERNOON CUMULUS DEVELOPING. IN ADDITION, DEW POINTS WILL BE DROPPING INTO THE 50S THROUGH THE COURSE OF THE DAY, GIVING THE AREA RELIEF FROM THE HUMIDITY. A BLEND OF MET/MAV GUIDANCE PUTS AFTERNOON HIGH TEMPERATURES MAINLY INTO THE 80S ACROSS THE REGION, WITH PERHAPS THE HIGHER TERRAIN IN THE POCONOS ONLY REACHING THE MID TO UPPER 70S. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... THE SYNOPTIC SETUP IS COMPRISED OF A STRONG UPPER-LEVEL TROUGH IN SOUTHEASTERN CANADA AND THE NORTHEAST WEDNESDAY NIGHT AND THURSDAY, WHICH THEN SHIFTS EAST SOME INTO FRIDAY. THIS FEATURE SHOULD SHIFT EAST LATER FRIDAY AS A SHORT WAVE TROUGH DIVES SOUTHEASTWARD FROM THE MIDWEST. THIS TROUGH SHOULD AMPLIFY THE MAIN UPPER-LEVEL TROUGH ONCE AGAIN ACROSS THE NORTHEAST OVER THE WEEKEND, WITH SOME RELAXATION POSSIBLE EARLY NEXT WEEK. THERE ARE SOME HINTS WITHIN THE GUIDANCE THAT A STRONG RIDGE ACROSS THE PLAINS MAY START TO EXPAND NORTHEASTWARD NEXT WEEK INTO THE MID ATLANTIC. WE USED A MODEL BLEND FOR WEDNESDAY NIGHT THROUGH FRIDAY, THEN WENT WITH THE 12Z WPC GUIDANCE. SOME ADJUSTMENTS WERE THEN MADE FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES. FOR WEDNESDAY NIGHT...AN UPPER-LEVEL TROUGH IS IN PLACE, HOWEVER SURFACE HIGH PRESSURE IS FORECAST TO BUILD OVER THE AREA. THIS SHOULD RESULT IN LESS CLOUDINESS AND A DIMINISHING WIND ALONG WITH MUCH COOLER TEMPERATURES. FOR THURSDAY AND FRIDAY...HIGH PRESSURE OVER THE AREA GRADUALLY WEAKENS DURING THIS TIME FRAME, HOWEVER AN AIRMASS CHARACTERIZED BY LOW HUMIDITY LEVELS IS ANTICIPATED TO REMAIN FOR MUCH OF THE AREA. AN UPPER-LEVEL TROUGH IS FORECAST TO AMPLIFY ACROSS THE NORTHEAST AS SHORT WAVE ENERGY DIGS INTO ITS BASE. THIS IS MOST NOTED ACROSS NEW ENGLAND WHERE THE COLD POOL ALOFT IS MORE PRONOUNCED. THE COOLING ALOFT MAY ALLOW FOR A BIT MORE CLOUDINESS ACROSS OUR NORTHERN AREAS ESPECIALLY ON FRIDAY, HOWEVER IT APPEARS THAT ANY SHOWER CHC IS RATHER LOW. A SOUTHERN TRACKING SHORT WAVE THOUGH MAY ALLOW FOR A WEAK SURFACE LOW TO DEVELOP ALONG A FRONTAL BOUNDARY TO OUR SOUTH. GIVEN THE ORIENTATION OF THE UPPER-LEVEL TROUGH AND A SEPARATE BOUNDARY ARRIVING FROM THE NORTH, THIS FEATURE SHOULD REMAIN FAR ENOUGH TO OUR SOUTH. AS A RESULT, WE CONTINUED WITH A DRY FORECAST. FOR SATURDAY AND SUNDAY...SOME UPPER-LEVEL RIDGING SHOULD MOVE ACROSS THE AREA ON SATURDAY AND A WARM FRONT MAY LIFT NORTH AS A RESULT. LOW PRESSURE IS FORECAST TO TRACK WELL TO OUR NORTH LATE SATURDAY AND SUNDAY, WITH AN ASSOCIATED COLD FRONT MOVING OUR WAY LATE SUNDAY. THE FRONT ITSELF MAY BEGIN TO WEAKEN, HOWEVER A POSSIBLE PRE-FRONTAL TROUGH MAY HELP FOCUS SOME CONVECTION AS WAA OCCURS IN CONJUCTION WITH SOME MOISTURE RETURN. THE MAIN PORTION OF THE UPPER-LEVEL TROUGH IS FORECAST TO TRACK FARTHER NORTH, THEREFORE MUCH OF THE LIFT FOR ORGANIZED CONVECTION COULD BE FARTHER NORTH AS WELL. WE FAVORED WPC GUIDANCE WHICH CARRIES CHC POPS ON SUNDAY ESPECIALLY IN THE AFTERNOON AND EVENING. FOR MONDAY AND TUESDAY...A FRONTAL BOUNDARY OR LINGERING SURFACE TROUGH IN OUR VICINITY MIGHT BE ABLE TO FORCE SOME CONVECTION MONDAY, AS OUR AREA REMAINS INFLUENCED BY AN UPPER-LEVEL TROUGH MIGRATING ACROSS THE NORTHEAST. THE UPPER-LEVEL TROUGH REMAINS ON TUESDAY, ALTHOUGH WEAK SURFACE HIGH PRESSURE IS CURRENTLY FORECAST TO BE NEARBY. FOR NOW, WE INCLUDED A SLIGHT CHC POP IN THE GRIDDED DATABASE/FORECAST. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. LATE-DAY AND THIS EVENING...MOSTLY VFR CONDITIONS ARE EXPECTED FOR THE TAF SITES OUTSIDE OF ANY ISOLATED TO SCATTERED SHWRS/TSTORMS WHICH COULD TEMPORARILY REDUCE CONDITIONS, ESPECIALLY VSBYS, TO MVFR OR POSSIBLE IFR. REGARDING THE WINDS, WESTERLY WINDS AVERAGING 5 TO 8 KNOTS AT LATE-DAY WILL BECOME NORTHWESTERLY AT 10 KNOTS OR LESS BETWEEN THE 02Z TO 04Z TIMEFRAME FOLLOWING THE PASSAGE OF A COLD FRONT THROUGH THE AREA. OVERNIGHT...VFR CONDITIONS ARE EXPECTED WITH SKIES CLEARING THROUGH THE OVERNIGHT. NORTHWEST WINDS AVERAGING 5 TO 10 KNOTS WILL CONTINUE. WEDNESDAY...VFR CONDITIONS WITH PERHAPS SOME MIDDAY TO AFTERNOON CUMULUS DEVELOPING WITH BASES 5,000 FEET. NORTHWEST WINDS CONTINUE, WITH SOME GUSTS BETWEEN 15 TO 20 KNOTS POSSIBLE INTO THE AFTERNOON. OUTLOOK... WEDNESDAY NIGHT...VFR WITH NORTHWEST WINDS DIMINISHING TO 5 KNOTS OR LESS. THURSDAY AND FRIDAY...VFR. WEST-NORTHWEST WINDS NEAR 10 KNOTS, ALTHOUGH LIGHTER EACH NIGHT. SATURDAY AND SUNDAY...VFR OVERALL, WITH SOME INCREASE IN CLOUDS ESPECIALLY SUNDAY. SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE SUNDAY ESPECIALLY IN THE AFTERNOON. && .MARINE... SUB-ADVISORY CONDITIONS ARE EXPECTED ON THE AREA WATERS TONIGHT AND THROUGH THE DAYTIME WEDNESDAY. HOWEVER, SOME SCATTERED SHWRS/TSTORMS ARE POSSIBLE THROUGH TONIGHT ASSOCIATED WITH A COLD FRONT, ESPECIALLY FOR THE SOUTHERN COASTAL WATERS, YIELDING POSSIBLE BRIEF HIGHER WINDS AND/OR SEAS. FOLLOWING THE COLD FRONT PASSAGE AROUND MIDNIGHT OR SO ACROSS THE WATERS, A WIND SHIFT TO THE NORTHWEST IS ANTICIPATED. DURING THE DAYTIME WEDNESDAY THE WEST-NORTHWEST WINDS COULD GUST AROUND 20 KNOTS AT TIMES, ESPECIALLY FOR THE COASTAL WATERS. OUTLOOK... WEDNESDAY NIGHT AND THURSDAY...THE CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CRITERIA AS HIGH PRESSURE BUILDS IN. THIS WILL RESULT IN SOME DECREASE IN THE WINDS. FRIDAY THROUGH SUNDAY...A WEAK FRONT ARRIVES FROM THE NORTH FRIDAY HOWEVER IT THEN LOOKS TO LIFT BACK NORTH AS A WARM FRONT LATER SATURDAY. A SOUTHERLY WIND SHOULD INCREASE SUNDAY AHEAD OF A COLD FRONT, HOWEVER THE CONDITIONS OVERALL SHOULD REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...GORSE NEAR TERM...KLINE SHORT TERM...KLINE LONG TERM...GORSE AVIATION...GORSE/KLINE MARINE...GORSE/KLINE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
340 AM EDT TUE JUL 21 2015 .DISCUSSION... TODAY AND TONIGHT...LTST REGIONAL ANALYSIS SHOWS NO SIG CHG IN MAP FEATURES SINCE THE WEEKEND WITH PRESENCE OF A Q/S BOUNDARY IN PLACE ALONG THE MID ATLC SEABOARD TO THE NRN GULF COAST. LTST 915 MHZ PROFILER WINDS @ XMR HAVE SHOWN A LAYERED INCREASE IN SPEEDS FROM THE SFC THROUGH THE MID LEVELS AS THE TAIL END OF SOME MID LEVEL ENERGY TRANSITS NORTH OF THE STATE. THE SETUP FOR TODAY REMAINS ANOTHER ROUND OF SCT STORMS ONCE SFC HEATING AND BOUNDARY DEVELOPMENT COMMENCES. PWAT VALUES NR 2 INCHES COUPLED WITH SW STEERING WL ONCE AGAIN FAVOR THE I-4 CORRIDOR FOR INITIAL STORM ACTIVITY WITH INCRSG COVERAGE TOWARD THE E CST AFTER INTERACTION WITH BOUNDARIES. LTST HRRR GUID SHOWS A RATHER EARLY DEVELOPMENT OF THE INITIAL ACTIVITY BEFORE NOON NEAR LAKE/VOLUSIA COS. WL KEEP A MODEST N-S GRADIENT OF POP COVERAGE WITH SCT MENTION MOST ALL AREAS. THE ONLY INHIBITING FACTOR REMAINS MID LEVEL TEMPS AROUND -6C (WHICH IS ABOUT 1-2C WARMER THAN NORMAL). STORMS WL LARGELY COME TO AN END FROM 9-10 PM WHILE SHIFTING OVER THE ATLC WATERS AND DISSIPATING. WED-SAT...DIGGING 500MB TROUGH OVER THE EASTERN PACIFIC AND U.S. WEST COAST BUILDS THE 500MB RIDGE OVER THE NATIONS CENTER FROM AROUND A 5900 METER RIDGE WED TO A 5950 METER RIDGE FRI. THE BUILDING RIDGE ALSO DEEPENS THE TROUGHING PATTERN OVER THE SOUTHEAST STATES AND FLORIDA DURING THE SAME TIME PERIOD. THE DEEPENING TROUGHING ALSO HELPS TO PUSH A FRONTAL BOUNDARY/TROUGH AND THE MOISTURE POOLING AHEAD OF IT SOUTHWARD OVER THE SOUTHEAST STATES AND COMING TO A STOP OVER THE SOUTHERN SECTION OF CENTRAL FLORIDA AND SOUTH FLORIDA BY SUN. THIS MODEL RUNS DEPICTION OF THE MOISTURE RIBBON ASSOCIATED WITH THE BOUNDARY LOOKS TO BE WIDER AND HIGHER MOISTURE VALUES TOPPING 2 INCHES OF PRECIPITABLE WATER BOTH FRI AND SAT. IF IT WERE NOT FOR LIGHT UPPER LEVEL/JET STREAM LEVEL WINDS AND WEAK DISTURBANCES MOVING THROUGH THE 500MB FLOW RAIN CHANCES WOULD MOST LIKELY BE HIGHER THAN THEIR MAS OF 50-60 PERCENT ON FRI. HIGHS MAINLY AROUND 90 AT THE COAST AND LOW 90S INTERIOR. LOWS GENERALLY IN THE MID 70S WITH UPPER 70S RIGHT AT THE COAST SOUTHERN BREVARD SOUTH. SUN-MON...SOME RELIEF FROM THE PERSISTENT SOUTHWEST TO WEST WIND PATTERN AS THE FRONT IS FORECAST TO HAVE PUSHED INTO SOUTH FLORIDA AND WEAK HIGH PRESSURE STRETCHING ALONG THE U.S. EAST COAST AND WESTERN ATLANTIC BUILDS ACROSS NORTH FLORIDA AND INTO THE NORTHEAST GULF OF MEXICO. THE RESULTING NORTHEAST TO EAST WIND FLOW BRINGS IN A MORE STABLE...YET STILL MOIST...AIR MASS TO EAST CENTRAL FLORIDA. THE WEATHER PATTERNS SHIFT TO THE MORE TYPICAL ONSHORE/EASTERLY PATTERN. MORNING SHOWERS AT THE COAST TRANSITIONING TO STORMS FOR THE INTERIOR. TEMPERATURES FALLING BACK TO THE MID AND UPPER 80S AT THE COAST AND LOW 90S INLAND DUE TO EARLIER SEA BREEZES PUSHING WEST OVER EAST CENTRAL FLORIDA. && .AVIATION... VFR CONDS THROUGH 21/15Z WITH ISOLD SHRA/TS WITH MVFR MOVING EWD FROM THE FL GULF CST AFFECTING KLEE THEN SPREADING EWD WHILE INCREASING IN CVG OVER REMAINDER OF SITES FM 21/17Z-21/22Z. && .MARINE...PRESENCE OF A LITTLE TIGHTER GRADIENT OF OFFSHORE COMPONENT WL DELAY OR ONSHORE BREEZE DEVELOPMENT. SEAS AOB 2FT NEARSHORE AND 2-3FT OFFSHORE. SCT SHRAS/TSRAS MVG OFFSHORE FROM AROUND 3 PM THROUGH SUNSET. WED-SAT...WEST TO SOUTHWEST WINDS THROUGH THE PERIOD WITH SOME INCREASE IN THE PRESSURE GRADIENT BY THU-FRI WHICH WILL DELAY SEA BREEZE FORMATION EVEN MORE...AND POSSIBLY PROHIBIT FORMATION EVEN ALONG THE TREASURE COAST. PRIMARY CONCERN FOR BOATERS WILL BE OFFSHORE MOVING STORMS PRODUCING GUSTY WINDS AND LIGHTNING AS WELL AS A FASTER STORM MOTION LATE WEEK. && .PRELIMINARY POINT TEMPS/POPS... DAB 92 76 93 76 / 50 30 40 30 MCO 92 76 93 76 / 50 20 40 20 MLB 93 76 94 76 / 40 30 30 20 VRB 93 75 94 75 / 30 30 30 20 LEE 90 78 91 78 / 60 20 50 30 SFB 93 78 92 78 / 50 20 50 30 ORL 93 78 93 77 / 50 20 50 20 FPR 94 74 94 75 / 30 30 30 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...PENDERGRAST LONG TERM....WIMMER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
802 PM EDT WED JUL 22 2015 .UPDATE... EVENING CONVECTION WILL CONTINUE FOR THE NEXT SEVERAL HOURS. UPDATED POPS EARLIER TO REFLECT THE CURRENT RADAR AND HRRR TRENDS. MAIN UPDATE IS TO REMOVE THE HEAT ADVISORY. && .PREV DISCUSSION... /ISSUED 257 PM EDT WED JUL 22 2015/ SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... SHORT TERM /TODAY THROUGH THURSDAY/... CURRENT RADAR LOOP SHOWS SHOWERS WITH SOME ISOLATED THUNDERSTORMS MOVING INTO NW GA. WEAK WEST TO NORTHWEST FLOW IS STILL EXPECTED TO BECOME A LITTLE MORE ACTIVE OVER THE NEXT 24 HOURS. EXCEPTING TO SEE MORE AREAL COVERAGE TODAY THAN YESTERDAY WITH THE PRECIPITATION BUT THURSDAY APPEARS TO BE OUR MOT ACTIVE DAY. DEEPER MOISTURE OVER TN WILL CONTINUE TO SINK SOUTH INTO GA THROUGH THU AFTERNOON BRINGING A STRONGER SHORT WAVE AND LIKELY POPS TO THE STATE. ALSO EXPECTING INCREASED INSTABILITY SO THE MARGINAL RISK AREA SPC HAS OVER ALMOST THE ENTIRE STATE FOR DAY 2 STILL LOOKS GOOD. PERSISTENCE ON TEMPS ACROSS CENTRAL GA LOOKS GOOD WITH SLIGHTLY COOLER TEMPS ACROSS NORTH GA. COOLER TEMPS CWA WIDE ON THURSDAY DUE TO ADDITIONAL CLOUDS AND PRECIP. 01 LONG TERM /FRIDAY THROUGH WEDNESDAY/... NOT MANY CHANGES TO THE PREVIOUS LONG TERM FORECAST. FOR FRIDAY...LARGE SCALE SYNOPTIC PATTERN WILL BE DOMINATED BY BROAD MID-LEVEL RIDGING OVER THE SOUTHERN PLAINS...SUPPORTING NORTHWEST FLOW ALOFT ACROSS THE SOUTHEAST US. A WEAK DISTURBANCE WITHIN THIS FLOW WILL INTERACT WITH A NEARLY STATIONARY SURFACE BOUNDARY TO PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT...PARTICULARLY ACROSS THE CENTRAL PORTION OF THE CWA DURING THE AFTERNOON. MEANWHILE...DRIER AIR WILL BEGIN TO FILTER INTO THE NORTHERN PORTION OF THE CWA. SATURDAY AND SUNDAY...RELATIVELY TRANQUIL WEATHER EXPECTED AS SURFACE HIGH PRESSURE RIDGES DOWN THE SPINE OF THE APPALACHIANS AND H5 RIDGE BEGINS TO BUILD SLIGHTLY EAST OVER THE SOUTHEAST. RELATIVELY DRIER AIR /PW VALUES 1-1.50INCHES/ SHOULD SUPPRESS WIDESPREAD CONVECTION...BUT CANNOT RULE OF A FEW DIURNALLY ENHANCED THUNDERSTORMS WITH THE CONTINUED WARM TEMPERATURES. MONDAY THROUGH WEDNESDAY...EXPECT A GRADUAL INCREASE IN MOISTURE DURING THIS PERIOD. POTENT TROUGH MOVING ACROSS NORTHERN ROCKIES WILL FLATTEN THE PERSISTENT H5 RIDGE AND GENERATE MINOR PERTURBATIONS IN THE MID LEVEL FLOW PATTERN. GFS AND ECMWF BOTH INDICATE RIDGE WILL SUPPRESS WIDESPREAD PRECIPITATION FOR THE MOST PART MONDAY AND TUESDAY...BUT DO EXPECT THESE DISTURBANCES TO AFFECT THE AREA BY MID WEEK. THEREFORE...EXPECT POPS TO INCREASE BY WEDNESDAY. WILL ALSO CONTINUE TO MONITOR THE POTENTIAL FOR A PSUEDO-TROPICAL DISTURBANCE DEVELOPING OFF THE EAST COAST OF FLORIDA AT THE END OF THE PERIOD...AS INDICATED BY THE ECMWF. KOVACIK && .AVIATION... 00Z UPDATE... EVENING CONVECTION WILL WIND DOWN IN THE NEXT HOUR OR TWO. DIURNAL CLOUDS AND SCT CONVECTION STILL EXPECTED TOMORROW AFTERNOON. WINDS WILL REMAIN ON THE WEST SIDE AND MAY GUSTS FREQUENTLY TO AROUND 15 KT. //ATL CONFIDENCE...00Z UPDATE... HIGH CONFIDENCE ALL ELEMENTS. && .PRELIMINARY POINT TEMPS/POPS... ATHENS 74 90 73 91 / 40 60 40 30 ATLANTA 75 88 73 90 / 40 60 40 30 BLAIRSVILLE 69 84 66 85 / 40 70 40 40 CARTERSVILLE 74 86 73 90 / 40 70 40 30 COLUMBUS 77 92 75 93 / 30 60 50 40 GAINESVILLE 72 89 72 88 / 40 70 40 30 MACON 75 93 75 93 / 30 60 50 40 ROME 73 88 72 91 / 50 70 40 30 PEACHTREE CITY 73 89 73 90 / 30 60 40 30 VIDALIA 77 95 76 93 / 30 50 50 50 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1240 PM CDT TUE JUL 21 2015 .UPDATE... ISSUED AT 1028 AM CDT TUE JUL 21 2015 HIGH PRESSURE BUILDING INTO THE MIDWEST BEHIND A COLD FRONT THAT PASSED THROUGH CENTRAL IL OVERNIGHT WILL BRING COOLER AND DRIER CONDITIONS TODAY...ALONG WITH LIGHT NORTHERLY BREEZES TO AROUND 10 MPH. SKIES WILL BE MOSTLY CLEAR...ALTHOUGH SOME SCATTERED AFTERNOON CLOUD COVER WILL DEVELOP. AN INVERSION AROUND 5000 FEET AGL WILL LIMIT VERTICAL DEVELOPMENT OF CLOUDS...SO NO PRECIPITATION EXPECTED. HIGHS STILL LOOK ON TRACK TO REACH AROUND 80 MOST AREAS...TO AROUND 84 IN SOUTHEASTERN PORTIONS OF THE FORECAST AREA. DEWPOINTS IN THE 60S TO AROUND 70 THIS MORNING SHOULD DECREASE TO AROUND 60-65 BY AFTERNOON WITH ADVECTION OF DRIER AIR FROM THE NORTH. NO UPDATES NEEDED THIS MORNING OTHER THAN MINOR ADJUSTMENTS TO HOURLY TEMP/DEWPOINT/WIND TRENDS. && .SHORT TERM...(TODAY) ISSUED AT 318 AM CDT TUE JUL 21 2015 FRONTAL BOUNDARY LYING ACROSS SOUTHEAST ILLINOIS THIS MORNING WITH MOST OF THE DEEP CONVECTION SOUTH OF THIS FEATURE WITH A SECONDARY BOUNDARY NOTED ON THE LATEST SURFACE ANALYSIS EXTENDING ACROSS THE ILLINOIS RIVER VALLEY. SOME BROKEN CLOUDS ASSOCIATED WITH THE SECONDARY BOUNDARY BUT HAVE NOT SEEN ANY PRECIP ASSOCIATED WITH THE BAND OF CLOUDS. SOME PATCHY FOG HAS DEVELOPED OVER PARTS OF EAST CENTRAL ILLINOIS OVER THE PAST SEVERAL HOURS AND WILL SEE THAT GRADUALLY SHIFT INTO SOUTH CENTRAL THROUGH SOUTHEAST ILLINOIS EARLY THIS MORNING AS DRIER AIR ADVECTS SOUTHEAST INTO THE FORECAST AREA. OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST THIS AFTERNOON. FORECAST SOUNDINGS OFF THE GFS SUGGEST WE SHOULD MIX DOWN FROM ABOUT 850 MB THIS AFTERNOON WHICH WOULD GIVE US HIGHS IN THE 80 TO 84 DEGREE RANGE, WHILE THE RAP SOUNDINGS WERE MUCH MORE AGGRESSIVE WITH MIXING HEIGHTS YIELDING HIGHS IN THE MID TO EVEN UPPER 80S IN OUR SOUTHEAST COUNTIES. THINK THE CURRENT RAP MAY BE UNDERPLAYING THE COOL ADVECTION FILTERING IN FROM THE NORTHWEST SO WILL SIDE WITH THE MORE CONSERVATIVE GFS SOLUTION AND TEMPERATURES FOR THIS AFTERNOON. .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 318 AM CDT TUE JUL 21 2015 HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY. FOR NOW, THE FORECAST IS DRY, BUT THE NAM IS SHOWING SIGNS OF A SLIGHTLY DIFFERENT TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS WILL REMAIN IN THE FORECAST FOR THU/THU NIGHT. AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE AXIS DRIFTING OVER THE MIDWEST, A WARMING TREND RETURNS FOR THE END OF THE WEEK AND INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION. CONCERNED ABOUT THE FORECAST THROUGH THE WEEKEND WITH REGARDS TO THE PRECIPITATION. UNDER THE EXPANSIVE RIDGE, MODELS ARE NOT HANDLING SMALL IMPULSES WITH ANY KIND OF CONTINUITY OR CONSENSUS. SLIGHTS AND LOW CHANCE POPS DOMINATE THE SUPERBLEND AS A RESULT THROUGH THE WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1240 PM CDT TUE JUL 21 2015 VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS...WITH SCATTERED CLOUD COVER AT 3.5 TO 4 KFT AGL THROUGH THE LATE AFTERNOON HOURS. ISOLD MVFR CIGS POSSIBLE WITH LOCALLY LOWERED CEILINGS...BUT COVERAGE TOO MINIMAL FOR MENTION IN 18Z TAFS. CLOUD COVER DISSIPATING AROUND SUNSET...AND RETURNING LATE MORNING WEDNESDAY. WINDS NNE 8-10 KTS DIMINISHING AFTER 00Z. WINDS BECOMING SE 4-8 KTS WEDNESDAY MORNING. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ONTON SHORT TERM...SMITH LONG TERM...HJS AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1028 AM CDT TUE JUL 21 2015 .UPDATE... ISSUED AT 1028 AM CDT TUE JUL 21 2015 HIGH PRESSURE BUILDING INTO THE MIDWEST BEHIND A COLD FRONT THAT PASSED THROUGH CENTRAL IL OVERNIGHT WILL BRING COOLER AND DRIER CONDITIONS TODAY...ALONG WITH LIGHT NORTHERLY BREEZES TO AROUND 10 MPH. SKIES WILL BE MOSTLY CLEAR...ALTHOUGH SOME SCATTERED AFTERNOON CLOUD COVER WILL DEVELOP. AN INVERSION AROUND 5000 FEET AGL WILL LIMIT VERTICAL DEVELOPMENT OF CLOUDS...SO NO PRECIPITATION EXPECTED. HIGHS STILL LOOK ON TRACK TO REACH AROUND 80 MOST AREAS...TO AROUND 84 IN SOUTHEASTERN PORTIONS OF THE FORECAST AREA. DEWPOINTS IN THE 60S TO AROUND 70 THIS MORNING SHOULD DECREASE TO AROUND 60-65 BY AFTERNOON WITH ADVECTION OF DRIER AIR FROM THE NORTH. NO UPDATES NEEDED THIS MORNING OTHER THAN MINOR ADJUSTMENTS TO HOURLY TEMP/DEWPOINT/WIND TRENDS. && .SHORT TERM...(TODAY) ISSUED AT 318 AM CDT TUE JUL 21 2015 FRONTAL BOUNDARY LYING ACROSS SOUTHEAST ILLINOIS THIS MORNING WITH MOST OF THE DEEP CONVECTION SOUTH OF THIS FEATURE WITH A SECONDARY BOUNDARY NOTED ON THE LATEST SURFACE ANALYSIS EXTENDING ACROSS THE ILLINOIS RIVER VALLEY. SOME BROKEN CLOUDS ASSOCIATED WITH THE SECONDARY BOUNDARY BUT HAVE NOT SEEN ANY PRECIP ASSOCIATED WITH THE BAND OF CLOUDS. SOME PATCHY FOG HAS DEVELOPED OVER PARTS OF EAST CENTRAL ILLINOIS OVER THE PAST SEVERAL HOURS AND WILL SEE THAT GRADUALLY SHIFT INTO SOUTH CENTRAL THROUGH SOUTHEAST ILLINOIS EARLY THIS MORNING AS DRIER AIR ADVECTS SOUTHEAST INTO THE FORECAST AREA. OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST THIS AFTERNOON. FORECAST SOUNDINGS OFF THE GFS SUGGEST WE SHOULD MIX DOWN FROM ABOUT 850 MB THIS AFTERNOON WHICH WOULD GIVE US HIGHS IN THE 80 TO 84 DEGREE RANGE, WHILE THE RAP SOUNDINGS WERE MUCH MORE AGGRESSIVE WITH MIXING HEIGHTS YIELDING HIGHS IN THE MID TO EVEN UPPER 80S IN OUR SOUTHEAST COUNTIES. THINK THE CURRENT RAP MAY BE UNDERPLAYING THE COOL ADVECTION FILTERING IN FROM THE NORTHWEST SO WILL SIDE WITH THE MORE CONSERVATIVE GFS SOLUTION AND TEMPERATURES FOR THIS AFTERNOON. .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 318 AM CDT TUE JUL 21 2015 HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY. FOR NOW, THE FORECAST IS DRY, BUT THE NAM IS SHOWING SIGNS OF A SLIGHTLY DIFFERENT TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS WILL REMAIN IN THE FORECAST FOR THU/THU NIGHT. AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE AXIS DRIFTING OVER THE MIDWEST, A WARMING TREND RETURNS FOR THE END OF THE WEEK AND INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION. CONCERNED ABOUT THE FORECAST THROUGH THE WEEKEND WITH REGARDS TO THE PRECIPITATION. UNDER THE EXPANSIVE RIDGE, MODELS ARE NOT HANDLING SMALL IMPULSES WITH ANY KIND OF CONTINUITY OR CONSENSUS. SLIGHTS AND LOW CHANCE POPS DOMINATE THE SUPERBLEND AS A RESULT THROUGH THE WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 605 AM CDT TUE JUL 21 2015 VFR CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA THRU THIS PERIOD. WE SHOULD SEE SOME SCATTERED TO OCCASIONALLY BROKE CUMULUS DEVELOP BETWEEN 14-16Z WITH BASES IN THE 2800 TO 4000 FOOT RANGE. AT THIS TIME WILL GO WTIH A SCATTERED BASE LATER THIS MORNING AROUND 3500 FEET. SURFACE WINDS WILL BE OUT OF THE NORTH AT 10 TO 15 KTS...WITH A NORTHERLY COMPONENT EXPECTED TONIGHT WITH SPEEDS OF AROUND 5 KTS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ONTON SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
608 AM CDT TUE JUL 21 2015 .SHORT TERM...(TODAY) ISSUED AT 318 AM CDT TUE JUL 21 2015 FRONTAL BOUNDARY LYING ACROSS SOUTHEAST ILLINOIS THIS MORNING WITH MOST OF THE DEEP CONVECTION SOUTH OF THIS FEATURE WITH A SECONDARY BOUNDARY NOTED ON THE LATEST SURFACE ANALYSIS EXTENDING ACROSS THE ILLINOIS RIVER VALLEY. SOME BROKEN CLOUDS ASSOCIATED WITH THE SECONDARY BOUNDARY BUT HAVE NOT SEEN ANY PRECIP ASSOCIATED WITH THE BAND OF CLOUDS. SOME PATCHY FOG HAS DEVELOPED OVER PARTS OF EAST CENTRAL ILLINOIS OVER THE PAST SEVERAL HOURS AND WILL SEE THAT GRADUALLY SHIFT INTO SOUTH CENTRAL THROUGH SOUTHEAST ILLINOIS EARLY THIS MORNING AS DRIER AIR ADVECTS SOUTHEAST INTO THE FORECAST AREA. OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST THIS AFTERNOON. FORECAST SOUNDINGS OFF THE GFS SUGGEST WE SHOULD MIX DOWN FROM ABOUT 850 MB THIS AFTERNOON WHICH WOULD GIVE US HIGHS IN THE 80 TO 84 DEGREE RANGE, WHILE THE RAP SOUNDINGS WERE MUCH MORE AGGRESSIVE WITH MIXING HEIGHTS YIELDING HIGHS IN THE MID TO EVEN UPPER 80S IN OUR SOUTHEAST COUNTIES. THINK THE CURRENT RAP MAY BE UNDERPLAYING THE COOL ADVECTION FILTERING IN FROM THE NORTHWEST SO WILL SIDE WITH THE MORE CONSERVATIVE GFS SOLUTION AND TEMPERATURES FOR THIS AFTERNOON. .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 318 AM CDT TUE JUL 21 2015 HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY. FOR NOW, THE FORECAST IS DRY, BUT THE NAM IS SHOWING SIGNS OF A SLIGHTLY DIFFERENT TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS WILL REMAIN IN THE FORECAST FOR THU/THU NIGHT. AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE AXIS DRIFTING OVER THE MIDWEST, A WARMING TREND RETURNS FOR THE END OF THE WEEK AND INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION. CONCERNED ABOUT THE FORECAST THROUGH THE WEEKEND WITH REGARDS TO THE PRECIPITATION. UNDER THE EXPANSIVE RIDGE, MODELS ARE NOT HANDLING SMALL IMPULSES WITH ANY KIND OF CONTINUITY OR CONSENSUS. SLIGHTS AND LOW CHANCE POPS DOMINATE THE SUPERBLEND AS A RESULT THROUGH THE WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 605 AM CDT TUE JUL 21 2015 VFR CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA THRU THIS PERIOD. WE SHOULD SEE SOME SCATTERED TO OCCASIONALLY BROKE CUMULUS DEVELOP BETWEEN 14-16Z WITH BASES IN THE 2800 TO 4000 FOOT RANGE. AT THIS TIME WILL GO WTIH A SCATTERED BASE LATER THIS MORNING AROUND 3500 FEET. SURFACE WINDS WILL BE OUT OF THE NORTH AT 10 TO 15 KTS...WITH A NORTHERLY COMPONENT EXPECTED TONIGHT WITH SPEEDS OF AROUND 5 KTS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
318 AM CDT TUE JUL 21 2015 .SHORT TERM...(TODAY) ISSUED AT 318 AM CDT TUE JUL 21 2015 FRONTAL BOUNDARY LYING ACROSS SOUTHEAST ILLINOIS THIS MORNING WITH MOST OF THE DEEP CONVECTION SOUTH OF THIS FEATURE WITH A SECONDARY BOUNDARY NOTED ON THE LATEST SURFACE ANALYSIS EXTENDING ACROSS THE ILLINOIS RIVER VALLEY. SOME BROKEN CLOUDS ASSOCIATED WITH THE SECONDARY BOUNDARY BUT HAVE NOT SEEN ANY PRECIP ASSOCIATED WITH THE BAND OF CLOUDS. SOME PATCHY FOG HAS DEVELOPED OVER PARTS OF EAST CENTRAL ILLINOIS OVER THE PAST SEVERAL HOURS AND WILL SEE THAT GRADUALLY SHIFT INTO SOUTH CENTRAL THROUGH SOUTHEAST ILLINOIS EARLY THIS MORNING AS DRIER AIR ADVECTS SOUTHEAST INTO THE FORECAST AREA. OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST THIS AFTERNOON. FORECAST SOUNDINGS OFF THE GFS SUGGEST WE SHOULD MIX DOWN FROM ABOUT 850 MB THIS AFTERNOON WHICH WOULD GIVE US HIGHS IN THE 80 TO 84 DEGREE RANGE, WHILE THE RAP SOUNDINGS WERE MUCH MORE AGGRESSIVE WITH MIXING HEIGHTS YIELDING HIGHS IN THE MID TO EVEN UPPER 80S IN OUR SOUTHEAST COUNTIES. THINK THE CURRENT RAP MAY BE UNDERPLAYING THE COOL ADVECTION FILTERING IN FROM THE NORTHWEST SO WILL SIDE WITH THE MORE CONSERVATIVE GFS SOLUTION AND TEMPERATURES FOR THIS AFTERNOON. && .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 318 AM CDT TUE JUL 21 2015 HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY. FOR NOW, THE FORECAST IS DRY, BUT THE NAM IS SHOWING SIGNS OF A SLIGHTLY DIFFERENT TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS WILL REMAIN IN THE FORECAST FOR THU/THU NIGHT. AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE AXIS DRIFTING OVER THE MIDWEST, A WARMING TREND RETURNS FOR THE END OF THE WEEK AND INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION. CONCERNED ABOUT THE FORECAST THROUGH THE WEEKEND WITH REGARDS TO THE PRECIPITATION. UNDER THE EXPANSIVE RIDGE, MODELS ARE NOT HANDLING SMALL IMPULSES WITH ANY KIND OF CONTINUITY OR CONSENSUS. SLIGHTS AND LOW CHANCE POPS DOMINATE THE SUPERBLEND AS A RESULT THROUGH THE WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1150 PM CDT MON JUL 20 2015 A NARROW LINE OF CLOUDS MOVING SOUTH INTO THE AREA DID HAVE SOME SHOWERS IN THEM EARLIER TONIGHT. BELIEVE THIS STILL POSSIBLE DURING THE OVERNIGHT HOURS FOR ABOUT 2-3HRS SO WILL KEEP VCSH IN TAFS TO START. BELIEVE THIS IS A REFLECTION OF A WEAK FRONT AND OBSERVATIONAL DATA SHOWS A DEFINITE WIND SHIFT ONCE FRONT GOES THROUGH. RELATIVELY DRIER AIR SHOULD MOVE INTO THE AREA BEHIND THE FRONT...BUT BELIEVE SOME LIGHT FOG STILL POSSIBLE AT ALL SITES REMAINDER OF THE NIGHT. ONCE FOG DISSIPATES IN THE MORNING SCATTERED CU WILL STILL BE POSSIBLE AT ALL SITES. ANY CU WILL BE DIURNAL AND DISSIPATE AFTER 00Z. WINDS WILL BE LIGHT AND VARIABLE EVEN AFTER WEAK FROPA IN COUPLE OF HOURS. THEN NORTHERLY WINDS ARE EXPECTED REMAINDER OF THE FORECAST PERIOD. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
249 AM CDT TUE JUL 21 2015 .SHORT TERM... 230 PM CDT THROUGH TONIGHT... A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL BE HARD TO COME BY. A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM. COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS. THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW TEMPERATURES BY DAYBREAK NEAR NORMAL. MTF && .LONG TERM... 328 PM CDT TUESDAY THROUGH MONDAY... NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER VORT MAX. TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE. GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS. THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM. RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NORTHWEST WINDS SHIFTING TO NORTH ARND 10 KT OVERNIGHT. * WINDS SHIFTING TO NELY LESS THAN 10KT BY LATE MORNING. KREIN //DISCUSSION...UPDATED 06Z... A COLD FRONT EXTENDING FROM SRN LOWER MICHIGAN ACROSS THE SRN END OF LAKE MICHIGAN INTO NRN IL WILL CONTINUE TO PUSH SOUTH THROUGH THE NIGHT. FOLLOWING THE PASSAGE OF THE FRONT...WINDS ACROSS THE REGION WILL SHIFT TO NLY...ARND 10KT INLAND AND A LITTLE STRONGER NEAR LAKE MICHIGAN. WINDS AT MDW/GYY SHOULD INCREASE TO 12-18KT FOR A SHORT TIME. AS HIGH PRESSURE BUILDS ACROSS THE REGION BEHIND THE FRONT...THE PRESSURE GRADIENT WILL WEAKEN AND WIND SPEEDS SHOULD DIMINISH. THE COMBINATION OF THE SLACK PRESSURE GRADIENT AND DIFFERENTIAL LAND- WATER HEATING SHOULD ALLOW A LAKE BREEZE TO DEVELOP. THE LATEST HIGH RES MODEL GUIDANCE SUGGESTS THAT THE LAKE BREEZE SET UP INVOF ORD/MDW BY LATE MORNING...WITH WINDS BECMG NNELY BY LATE MORNING AND THEN VEERING MORE NELY-ENELY THROUGH THE DAY. WINDS SHOULD BE LESS THAN 10 KT BEHIND THE LAKE BREEZE. THE BOUNDARY IS NOT EXPECTED TO REACH DPA/RFD AND WINDS THERE BACK NWLY THROUGH THE DAY TOMORROW. AT GYY...WINDS SHOULD REMAIN A BIT STRONGER AND NNELY THROUGH THE DAY. BY TOMORROW EVENING...THE LAKE BREEZE SHOULD WASH OUT AND WINDS SHOULD BECM LGT/VRBL AS THE CENTER OF THE HIGH PRESSURE CROSSES THE REGION. KREIN //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM CONFIDENCE IN WIND TRENDS WITH RESPECT TO LAKE BREEZE DETAILS...OTRW HIGH CONFIDENCE IN WIND TRENDS. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY...VFR. LIGHT WEST WINDS TURNING EAST WITH LAKE BREEZE IN THE AFTERNOON. THURSDAY...VFR. LIGHT SOUTH WINDS TURNING EAST-SOUTHEAST WITH LAKE INFLUENCE IN THE AFTERNOON. FRIDAY...VFR SOUTH WINDS. SATURDAY...VFR. CHANCE TSRA. SOUTHWEST WINDS. SUNDAY...VFR. WESTERLY WINDS. MDB && .MARINE... 245 AM CDT A COLD FRONT IS PUSHING SOUTH OF THE LAKE LATE TONIGHT. A SURGE OF COOLER AIR BEHIND THE FRONT WILL BRIEFLY INCREASE NLY WINDS OVER THE SRN TIP OF THE LAKE TO 15-25 KT BEFORE DIMINISHING LATER THIS MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE LAKE LATER TO DAY AND TONIGHT...REMAINING THE DOMINANT FEATURE OVER THE GREAT LAKES THROUGH LATE THIS WEEK. FOLLOWING THE BRIEF PERIOD OF BRISK WINDS THIS MORNING...CONDITIONS SHOULD BE RATHER QUIET OVER THE LAKE FOR THE REST OF THE WEEK. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1246 AM CDT TUE JUL 21 2015 .SHORT TERM... 230 PM CDT THROUGH TONIGHT... A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL BE HARD TO COME BY. A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM. COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS. THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW TEMPERATURES BY DAYBREAK NEAR NORMAL. MTF && .LONG TERM... 328 PM CDT TUESDAY THROUGH MONDAY... NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER VORT MAX. TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE. GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS. THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM. RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NORTHWEST WINDS SHIFTING TO NORTH ARND 10 KT OVERNIGHT. * WINDS SHIFTING TO NELY LESS THAN 10KT BY LATE MORNING. KREIN //DISCUSSION...UPDATED 06Z... A COLD FRONT EXTEDNING FROM SRN LOWER MICHIGAN ACROSS THE SRN END OF LAKE MICHIGAN INTO NRN IL WILL CONTINUE TO PUSH SOUTH THROUGH THE NIGHT. FOLLOWING THE PASSAGE OF THE FRONT...WINDS ACROSS THE REGION WILL SHIFT TO NLY...ARND 10KT INLAND AND A LITTLE STRONGER NEAR LAKE MICHIGAN. WINDS AT MDW/GYY SHOULD INCREASE TO 12-18KT FOR A SHORT TIME. AS HIGH PRESSURE BUILDS ACROSS THE REGION BEHIND THE FRONT...THE PRESSURE GRADIENT WILL WEAKEN AND WIND SPEEDS SHOULD DIMINISH. THE COMBINATION OF THE SLACK PRESSURE GRADIENT AND DIFFERENTIAL LAND- WATER HEATING SHOULD ALLOW A LAKE BREEZE TO DEVELOP. THE LATEST HIGH RES MODEL GUIDANCE SUGGESTS THAT THE LAKE BREEZE SET UP INVOF ORD/MDW BY LATE MORNING...WITH WINDS BECMG NNELY BY LATE MORNING AND THEN VEERING MORE NELY-ENELY THROUGH THE DAY. WINDS SHOULD BE LESS THAN 10 KT BEHIND THE LAKE BREEZE. THE BOUNDARY IS NOT EXPECTED TO REACH DPA/RFD AND WINDS THERE BACK NWLY THROUGH THE DAY TOMORROW. AT GYY...WINDS SHOULD REMAIN A BIT STRONGER AND NNELY THROUGH THE DAY. BY TOMORROW EVENING...THE LAKE BREEZE SHOULD WASH OUT AND WINDS SHOULD BECM LGT/VRBL AS THE CENTER OF THE HIGH PRESSURE CROSSES THE REGION. KREIN //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM CONFIDENCE IN WIND TRENDS WITH RESPECT TO LAKE BREEZE DETAILS...OTRW HIGH CONFIDENCE IN WIND TRENDS. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY...VFR. LIGHT WEST WINDS TURNING EAST WITH LAKE BREEZE IN THE AFTERNOON. THURSDAY...VFR. LIGHT SOUTH WINDS TURNING EAST-SOUTHEAST WITH LAKE INFLUENCE IN THE AFTERNOON. FRIDAY...VFR SOUTH WINDS. SATURDAY...VFR. CHANCE TSRA. SOUTHWEST WINDS. SUNDAY...VFR. WESTERLY WINDS. MDB && .MARINE... 230 PM CDT A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE LAKE FOR A QUIET MIDWEEK PERIOD. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
100 PM EDT TUE JUL 21 2015 .SYNOPSIS... ISSUED AT 648 AM EDT TUE JUL 21 2015 HIGH PRESSURE WILL MOVE INTO THE GREAT LAKES AND OHIO VALLEY REGION TODAY BRINGING COOLER TEMPERATURES AND LESS HUMID AIR. IT WILL BE MOSTLY SUNNY TODAY WITH HIGHS IN THE MIDDLE TO UPPER 70S. WITH MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT...LOW TEMPERATURES WILL FALL INTO THE 50S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 421 AM EDT TUE JUL 21 2015 SHORT WAVE MOVING ACROSS THE GREAT LAKES THIS MORNING WITH ASSOCIATED COLD FRONT SLOWLY WORKING SOUTH ACROSS OUR LOCAL AREA. A FEW ISOLATED SHOWERS HAD POPPED ALONG FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. HIRES HRRR AND RAP GUIDANCE HAD THIS HANDLED AND INDICATE AN ISOLATED SHRA REMAINS POSSIBLE THROUGH DAYBREAK IN THE NORTH AND NORTHEAST NEAR FRONT. A FEW OF THE HRRR RUNS TRIES TO DEVELOP WEAK SHOWERS ALONG FRONT IN THE SOUTHEAST LATER THIS MORNING. RECENT RADAR RETURNS HAVE BEGUN TO WEAKEN AND EXPECT MOST ACTIVITY WILL DIMINISH OR REMAIN VERY ISOLATED. WILL CARRY AN ISOLATED SHRA THROUGH 12Z DOWNSTREAM FROM CURRENT RADAR RETURNS BUT MOST AREAS WILL REMAIN DRY. ONCE COLD FRONT EXITS THE AREA HIGH PRESSURE WILL BUILD IN WITH SKIES BECOMING MOSTLY SUNNY. COOLER AND LESS HUMID AIR WILL FOLLOW TODAY. HIGHS IN THE 70S WITH COMFORTABLE HUMIDITY LEVELS. WITH HIGH OVER THE REGION TONIGHT SKIES WILL BE CLEAR AND WINDS LIGHT. THIS WILL ALLOW MIN TEMPS TO DROP INTO THE 50S. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 421 AM EDT TUE JUL 21 2015 A TRANQUIL PATTERN WILL PERSIST THROUGH FRIDAY AS AN UPPER LEVEL RIDGE GRADUALLY BUILDS NORTH OF THE OHIO RIVER. KEPT THE FORECAST DRY THROUGH FRIDAY NIGHT GIVEN A SEASONALLY DRY SOUNDING...SOMEWHAT OF A LOW LEVEL CAP...LARGE SCALE SUBSIDENCE AND STABLE MID LEVEL LAPSE...GENERALLY 4.0 TO 6.5 C/KM. KEPT THE GENERAL ONGOING TIMING FOR STORMS THIS WEEKEND AS SOME SHORT WAVE ENERGY FROM AN UPPER LEVEL TROF WILL BE ABLE TO TOP THE RIDGE AND DESCEND INTO THE WESTERN/UPPER GREAT LAKES REGION. BOTH THE GFS AND THE ECMWF ARE IN AGREEMENT WITH THE TIMING OF THIS SYSTEM. THESE MODELS ALSO EXPAND THE UPPER LEVEL RIDGE FARTHER NORTHEAST WITH 500 HEIGHTS BUILDING ABOVE 590 DEKAMETERS NEAR THE END OF THE PERIOD. OTHERWISE...HIGHS SHOULD BE FROM AROUND 80 TO THE MID 80S WITH LOWS AROUND 60 RISING INTO THE MID 60S AS THE UPPER LEVEL RIDGE BUILDS NORTHEAST EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 100 PM EDT TUE JUL 21 2015 VFR CONDITIONS EXPECTED THIS TAF CYCLE. SCT DIURNAL CU OVER THE AREA WILL QUICKLY DISSIPATE TOWARD SUNSET. N/NW WINDS 10-15KTS WILL ALSO DIMINISH THIS EVENING AND REMAIN LIGHT AND VARIABLE INTO WEDNESDAY AS HIGH PRESSURE CENTER WILL MOVE OVER THE AREA. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LOGSDON VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
650 AM EDT TUE JUL 21 2015 .SYNOPSIS... ISSUED AT 648 AM EDT TUE JUL 21 2015 HIGH PRESSURE WILL MOVE INTO THE GREAT LAKES AND OHIO VALLEY REGION TODAY BRINGING COOLER TEMPERATURES AND LESS HUMID AIR. IT WILL BE MOSTLY SUNNY TODAY WITH HIGHS IN THE MIDDLE TO UPPER 70S. WITH MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT...LOW TEMPERATURES WILL FALL INTO THE 50S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 421 AM EDT TUE JUL 21 2015 SHORT WAVE MOVING ACROSS THE GREAT LAKES THIS MORNING WITH ASSOCIATED COLD FRONT SLOWLY WORKING SOUTH ACROSS OUR LOCAL AREA. A FEW ISOLATED SHOWERS HAD POPPED ALONG FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. HIRES HRRR AND RAP GUIDANCE HAD THIS HANDLED AND INDICATE AN ISOLATED SHRA REMAINS POSSIBLE THROUGH DAYBREAK IN THE NORTH AND NORTHEAST NEAR FRONT. A FEW OF THE HRRR RUNS TRIES TO DEVELOP WEAK SHOWERS ALONG FRONT IN THE SOUTHEAST LATER THIS MORNING. RECENT RADAR RETURNS HAVE BEGUN TO WEAKEN AND EXPECT MOST ACTIVITY WILL DIMINISH OR REMAIN VERY ISOLATED. WILL CARRY AN ISOLATED SHRA THROUGH 12Z DOWNSTREAM FROM CURRENT RADAR RETURNS BUT MOST AREAS WILL REMAIN DRY. ONCE COLD FRONT EXITS THE AREA HIGH PRESSURE WILL BUILD IN WITH SKIES BECOMING MOSTLY SUNNY. COOLER AND LESS HUMID AIR WILL FOLLOW TODAY. HIGHS IN THE 70S WITH COMFORTABLE HUMIDITY LEVELS. WITH HIGH OVER THE REGION TONIGHT SKIES WILL BE CLEAR AND WINDS LIGHT. THIS WILL ALLOW MIN TEMPS TO DROP INTO THE 50S. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 421 AM EDT TUE JUL 21 2015 A TRANQUIL PATTERN WILL PERSIST THROUGH FRIDAY AS AN UPPER LEVEL RIDGE GRADUALLY BUILDS NORTH OF THE OHIO RIVER. KEPT THE FORECAST DRY THROUGH FRIDAY NIGHT GIVEN A SEASONALLY DRY SOUNDING...SOMEWHAT OF A LOW LEVEL CAP...LARGE SCALE SUBSIDENCE AND STABLE MID LEVEL LAPSE...GENERALLY 4.0 TO 6.5 C/KM. KEPT THE GENERAL ONGOING TIMING FOR STORMS THIS WEEKEND AS SOME SHORT WAVE ENERGY FROM AN UPPER LEVEL TROF WILL BE ABLE TO TOP THE RIDGE AND DESCEND INTO THE WESTERN/UPPER GREAT LAKES REGION. BOTH THE GFS AND THE ECMWF ARE IN AGREEMENT WITH THE TIMING OF THIS SYSTEM. THESE MODELS ALSO EXPAND THE UPPER LEVEL RIDGE FARTHER NORTHEAST WITH 500 HEIGHTS BUILDING ABOVE 590 DEKAMETERS NEAR THE END OF THE PERIOD. OTHERWISE...HIGHS SHOULD BE FROM AROUND 80 TO THE MID 80S WITH LOWS AROUND 60 RISING INTO THE MID 60S AS THE UPPER LEVEL RIDGE BUILDS NORTHEAST EARLY NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 648 AM EDT TUE JUL 21 2015 VFR CONDITIONS EXPECTED. ISOLATED SHOWERS HAVE DISSIPATED AND FRONT HAS CLEARED TAF SITES. WINDS WILL VEER TO ABOUT 340-360 DEGREES THIS MORNING AROUND 10 KNOTS THEN BACK TO 290-320 DEGREES THIS AFTERNOON. WINDS BECOME LIGHT AND VARIABLE THIS EVENING. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
422 AM EDT TUE JUL 21 2015 .SYNOPSIS... ISSUED AT 421 AM EDT TUE JUL 21 2015 HIGH PRESSURE WILL MOVE INTO THE GREAT LAKES AND OHIO VALLEY REGION TODAY BRINGING COOLER TEMPERATURES AND LESS HUMID AIR. IT WILL BE MOSTLY SUNNY TODAY WITH HIGHS IN THE MIDDLE TO UPPER 70S. WITH MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT...LOW TEMPERATURES WILL FALL INTO THE 50S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 421 AM EDT TUE JUL 21 2015 SHORT WAVE MOVING ACROSS THE GREAT LAKES THIS MORNING WITH ASSOCIATED COLD FRONT SLOWLY WORKING SOUTH ACROSS OUR LOCAL AREA. A FEW ISOLATED SHOWERS HAD POPPED ALONG FRONT ACROSS NORTHERN COUNTIES EARLY THIS MORNING. HIRES HRRR AND RAP GUIDANCE HAD THIS HANDLED AND INDICATE AN ISOLATED SHRA REMAINS POSSIBLE THROUGH DAYBREAK IN THE NORTH AND NORTHEAST NEAR FRONT. A FEW OF THE HRRR RUNS TRIES TO DEVELOP WEAK SHOWERS ALONG FRONT IN THE SOUTHEAST LATER THIS MORNING. RECENT RADAR RETURNS HAVE BEGUN TO WEAKEN AND EXPECT MOST ACTIVITY WILL DIMINISH OR REMAIN VERY ISOLATED. WILL CARRY AN ISOLATED SHRA THROUGH 12Z DOWNSTREAM FROM CURRENT RADAR RETURNS BUT MOST AREAS WILL REMAIN DRY. ONCE COLD FRONT EXITS THE AREA HIGH PRESSURE WILL BUILD IN WITH SKIES BECOMING MOSTLY SUNNY. COOLER AND LESS HUMID AIR WILL FOLLOW TODAY. HIGHS IN THE 70S WITH COMFORTABLE HUMIDITY LEVELS. WITH HIGH OVER THE REGION TONIGHT SKIES WILL BE CLEAR AND WINDS LIGHT. THIS WILL ALLOW MIN TEMPS TO DROP INTO THE 50S. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 421 AM EDT TUE JUL 21 2015 A TRANQUIL PATTERN WILL PERSIST THROUGH FRIDAY AS AN UPPER LEVEL RIDGE GRADUALLY BUILDS NORTH OF THE OHIO RIVER. KEPT THE FORECAST DRY THROUGH FRIDAY NIGHT GIVEN A SEASONALLY DRY SOUNDING...SOMEWHAT OF A LOW LEVEL CAP...LARGE SCALE SUBSIDENCE AND STABLE MID LEVEL LAPSE...GENERALLY 4.0 TO 6.5 C/KM. KEPT THE GENERAL ONGOING TIMING FOR STORMS THIS WEEKEND AS SOME SHORT WAVE ENERGY FROM AN UPPER LEVEL TROF WILL BE ABLE TO TOP THE RIDGE AND DESCEND INTO THE WESTERN/UPPER GREAT LAKES REGION. BOTH THE GFS AND THE ECMWF ARE IN AGREEMENT WITH THE TIMING OF THIS SYSTEM. THESE MODELS ALSO EXPAND THE UPPER LEVEL RIDGE FARTHER NORTHEAST WITH 500 HEIGHTS BUILDING ABOVE 590 DEKAMETERS NEAR THE END OF THE PERIOD. OTHERWISE...HIGHS SHOULD BE FROM AROUND 80 TO THE MID 80S WITH LOWS AROUND 60 RISING INTO THE MID 60S AS THE UPPER LEVEL RIDGE BUILDS NORTHEAST EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 145 AM EDT TUE JUL 21 2015 A FEW ISOLATED SHOWERS HAVE DEVELOPED NEAR THE FRONT EARLY THIS MORNING. COVERAGE IS MINIMAL SO WILL NOT INCLUDE IN TAFS GIVEN SUCH LOW PROBABILITY OF ANY RESTRICTIONS AT TERMINALS. OTHERWISE FRONT WILL CLEAR TAF SITES OVERNIGHT AND HIGH PRESSURE WILL BUILD IN. WINDS WILL BECOME NORTHERLY THIS MORNING THEN BACK TO NORTHWEST THIS AFTENROON IN THE 8 TO 12 KNOT RANGE. CLEAR SKIES AND LIGHT WINDS TONIGHT. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS JACKSON KY
1100 PM EDT WED JUL 22 2015 .UPDATE... ISSUED AT 1100 PM EDT WED JUL 22 2015 HAVE ONLY MADE VERY MINOR CHANGES ONCE AGAIN...BASED LATE EVENING OBS/TRENDS. UPDATE ISSUED AT 837 PM EDT WED JUL 22 2015 MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST BASED ON LATEST OBS AND 18Z MODEL RUNS...WITH LITTLE SUBSTANTIVE CHANGE. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 310 PM EDT WED JUL 22 2015 18Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING DEEPER INTO THE OHIO VALLEY AND NORTHERN KENTUCKY. THIS HAS BROUGHT DRIER AIR TO THE NORTHERN SECTIONS OF THE CWA WHERE SOME MID 50S ARE NOTED WHILE TO THE SOUTH MIDDLE AND UPPER 60S ARE COMMON. THE HIGH ALSO HELPED TO BREAK UP AND LIFT THE LOWER STRATUS DECK FROM THIS MORNING. ON SATELLITE AND RADAR...A PAIR OF MCVS ARE MOVING EAST INTO AND THROUGH THE TENNESSEE VALLEY. THE LEADING ONE OF THESE IS JUST ABOUT TO PUSH SOME LIGHT SHOWERS INTO THE CUMBERLAND VALLEY NEAR THE TENNESSEE BORDER. OTHERWISE...IT IS A PLEASANT ENOUGH DAY OUT THERE UNDER PARTLY SUNNY DAYS WITH TEMPERATURES RANGING FROM NEAR 80 NORTH TO THE MID 80S SOUTH ALONG WITH LIGHT NORTHWEST WINDS. THE MODELS ARE IN GOOD AGREEMENT WITH THE MAIN PATTERN ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE THAT FLAT FLOW CURRENTLY ABOVE KENTUCKY WILL BECOME MORE NORTHWESTERLY WITH TIME AS RIDGING BUILDS OVER THE SOUTHERN PLAINS INTO FRIDAY MORNING. DURING THIS TRANSITION...WEAK SHORTWAVES WILL RIDE THROUGH KENTUCKY STARTING WITH THE MCVS PASSING TO THE SOUTH THIS AFTERNOON AND TONIGHT. GIVEN THE SMALL SCALE NATURE OF THESE FEATURES WILL FAVOR THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX DETAILS. SENSIBLE WEATHER WILL FEATURE A SMALL CHANCE FOR SHOWERS OR A STRAY THUNDERSTORM ACROSS THE SOUTHERN TIER THROUGH THE EVENING AND INTO THE OVERNIGHT AS THE MINOR MID LEVEL WAVES PASS BY. THE CLOUDS ASSOCIATED WITH THESE SHOULD KEEP THE FOG A BIT MORE LIMITED THROUGH THE NIGHT AND INTO THURSDAY MORNING. THE THREAT OF CONVECTION CONTINUES FOR MUCH OF THE SOUTHERN PARTS OF THE AREA DURING THE DAY THURSDAY...BUT WITH LITTLE IN THE WAY OF SUPPORT FOR ANYTHING BECOMING ORGANIZED OR TOO STRONG. THIS LEADS TO A BETTER CHANCE FOR VALLEY FOG LATER THURSDAY NIGHT AS THE WAVES PULL OUT OF KENTUCKY. TEMPERATURES WILL BE NEAR NORMAL OR A LITTLE ON THE COOL SIDE THROUGH FRIDAY MORNING. USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WINDS INTO TONIGHT AND THEN THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS TO THE LOWS TONIGHT AND THURSDAY NIGHT BASED ON TERRAIN DIFFERENCES AND THE EXPECTATION OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE DRIER MET MOS THAN THE MAV TONIGHT AND THURSDAY WHILE WAS IN LINE WITH THE LOW POP CONSENSUS FOR THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 245 PM EDT WED JUL 22 2015 UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BE ENTRENCHED OVER TEXAS AND THE SOUTHERN PLAINS THROUGH THE PERIOD KEEPING NORTHWEST FLOW IN PLACE ACROSS THE OHIO AND TENNESSEE VALLEYS. DRY HIGH PRESSURE WILL BE IN PLACE AT THE SURFACE FRIDAY AND SATURDAY WITH A DRY AND SEASONABLY WARM AND NOT SO HUMID FORECAST THE RESULT. A SHORTWAVE WILL THEN TRAVERSE THE US/CANADIAN BORDER OVER THE WEEKEND FLATTENING THE RIDGE AND SENDING A WEAK COLD FRONT SOUTHEASTWARD TOWARD OUR REGION. THE FRONT IS EXPECTED TO REMAIN IN THE VICINITY WHILE GRADUALLY WASHING OUT EARLY NEXT WEEK. THIS WILL KEEP A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS IN OUR FORECAST SUNDAY THROUGH WEDNESDAY...WITH COVERAGE LIKELY PEAKING IN THE AFTERNOON AND EARLY EVENING HOURS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 934 PM EDT WED JUL 22 2015 CIGS WILL SPREAD NORTH OVER MOST OF THE JKL FORECAST AREA TONIGHT AND THURSDAY...BUT WILL BE LARGELY VFR. SOME AREAS OF MVFR WILL BE POSSIBLE DURING THE DAY THURSDAY...ESPECIALLY NEAR THE TN BORDER. SHOWERS WILL ALSO MAKE AN APPEARANCE...ESPECIALLY NEAR THE TN BORDER ON THURSDAY...AND THERE COULD BE A FEW THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...GREIF LONG TERM...ABE AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
934 PM EDT WED JUL 22 2015 .UPDATE... ISSUED AT 837 PM EDT WED JUL 22 2015 MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST BASED ON LATEST OBS AND 18Z MODEL RUNS...WITH LITTLE SUBSTANTIVE CHANGE. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 310 PM EDT WED JUL 22 2015 18Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING DEEPER INTO THE OHIO VALLEY AND NORTHERN KENTUCKY. THIS HAS BROUGHT DRIER AIR TO THE NORTHERN SECTIONS OF THE CWA WHERE SOME MID 50S ARE NOTED WHILE TO THE SOUTH MIDDLE AND UPPER 60S ARE COMMON. THE HIGH ALSO HELPED TO BREAK UP AND LIFT THE LOWER STRATUS DECK FROM THIS MORNING. ON SATELLITE AND RADAR...A PAIR OF MCVS ARE MOVING EAST INTO AND THROUGH THE TENNESSEE VALLEY. THE LEADING ONE OF THESE IS JUST ABOUT TO PUSH SOME LIGHT SHOWERS INTO THE CUMBERLAND VALLEY NEAR THE TENNESSEE BORDER. OTHERWISE...IT IS A PLEASANT ENOUGH DAY OUT THERE UNDER PARTLY SUNNY DAYS WITH TEMPERATURES RANGING FROM NEAR 80 NORTH TO THE MID 80S SOUTH ALONG WITH LIGHT NORTHWEST WINDS. THE MODELS ARE IN GOOD AGREEMENT WITH THE MAIN PATTERN ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE THAT FLAT FLOW CURRENTLY ABOVE KENTUCKY WILL BECOME MORE NORTHWESTERLY WITH TIME AS RIDGING BUILDS OVER THE SOUTHERN PLAINS INTO FRIDAY MORNING. DURING THIS TRANSITION...WEAK SHORTWAVES WILL RIDE THROUGH KENTUCKY STARTING WITH THE MCVS PASSING TO THE SOUTH THIS AFTERNOON AND TONIGHT. GIVEN THE SMALL SCALE NATURE OF THESE FEATURES WILL FAVOR THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX DETAILS. SENSIBLE WEATHER WILL FEATURE A SMALL CHANCE FOR SHOWERS OR A STRAY THUNDERSTORM ACROSS THE SOUTHERN TIER THROUGH THE EVENING AND INTO THE OVERNIGHT AS THE MINOR MID LEVEL WAVES PASS BY. THE CLOUDS ASSOCIATED WITH THESE SHOULD KEEP THE FOG A BIT MORE LIMITED THROUGH THE NIGHT AND INTO THURSDAY MORNING. THE THREAT OF CONVECTION CONTINUES FOR MUCH OF THE SOUTHERN PARTS OF THE AREA DURING THE DAY THURSDAY...BUT WITH LITTLE IN THE WAY OF SUPPORT FOR ANYTHING BECOMING ORGANIZED OR TOO STRONG. THIS LEADS TO A BETTER CHANCE FOR VALLEY FOG LATER THURSDAY NIGHT AS THE WAVES PULL OUT OF KENTUCKY. TEMPERATURES WILL BE NEAR NORMAL OR A LITTLE ON THE COOL SIDE THROUGH FRIDAY MORNING. USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WINDS INTO TONIGHT AND THEN THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS TO THE LOWS TONIGHT AND THURSDAY NIGHT BASED ON TERRAIN DIFFERENCES AND THE EXPECTATION OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE DRIER MET MOS THAN THE MAV TONIGHT AND THURSDAY WHILE WAS IN LINE WITH THE LOW POP CONSENSUS FOR THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 245 PM EDT WED JUL 22 2015 UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BE ENTRENCHED OVER TEXAS AND THE SOUTHERN PLAINS THROUGH THE PERIOD KEEPING NORTHWEST FLOW IN PLACE ACROSS THE OHIO AND TENNESSEE VALLEYS. DRY HIGH PRESSURE WILL BE IN PLACE AT THE SURFACE FRIDAY AND SATURDAY WITH A DRY AND SEASONABLY WARM AND NOT SO HUMID FORECAST THE RESULT. A SHORTWAVE WILL THEN TRAVERSE THE US/CANADIAN BORDER OVER THE WEEKEND FLATTENING THE RIDGE AND SENDING A WEAK COLD FRONT SOUTHEASTWARD TOWARD OUR REGION. THE FRONT IS EXPECTED TO REMAIN IN THE VICINITY WHILE GRADUALLY WASHING OUT EARLY NEXT WEEK. THIS WILL KEEP A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS IN OUR FORECAST SUNDAY THROUGH WEDNESDAY...WITH COVERAGE LIKELY PEAKING IN THE AFTERNOON AND EARLY EVENING HOURS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 934 PM EDT WED JUL 22 2015 CIGS WILL SPREAD NORTH OVER MOST OF THE JKL FORECAST AREA TONIGHT AND THURSDAY...BUT WILL BE LARGELY VFR. SOME AREAS OF MVFR WILL BE POSSIBLE DURING THE DAY THURSDAY...ESPECIALLY NEAR THE TN BORDER. SHOWERS WILL ALSO MAKE AN APPEARANCE...ESPECIALLY NEAR THE TN BORDER ON THURSDAY...AND THERE COULD BE A FEW THUNDERSTORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...GREIF LONG TERM...ABE AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
837 PM EDT WED JUL 22 2015 .UPDATE... ISSUED AT 837 PM EDT WED JUL 22 2015 MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST BASED ON LATEST OBS AND 18Z MODEL RUNS...WITH LITTLE SUBSTANTIVE CHANGE. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 310 PM EDT WED JUL 22 2015 18Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING DEEPER INTO THE OHIO VALLEY AND NORTHERN KENTUCKY. THIS HAS BROUGHT DRIER AIR TO THE NORTHERN SECTIONS OF THE CWA WHERE SOME MID 50S ARE NOTED WHILE TO THE SOUTH MIDDLE AND UPPER 60S ARE COMMON. THE HIGH ALSO HELPED TO BREAK UP AND LIFT THE LOWER STRATUS DECK FROM THIS MORNING. ON SATELLITE AND RADAR...A PAIR OF MCVS ARE MOVING EAST INTO AND THROUGH THE TENNESSEE VALLEY. THE LEADING ONE OF THESE IS JUST ABOUT TO PUSH SOME LIGHT SHOWERS INTO THE CUMBERLAND VALLEY NEAR THE TENNESSEE BORDER. OTHERWISE...IT IS A PLEASANT ENOUGH DAY OUT THERE UNDER PARTLY SUNNY DAYS WITH TEMPERATURES RANGING FROM NEAR 80 NORTH TO THE MID 80S SOUTH ALONG WITH LIGHT NORTHWEST WINDS. THE MODELS ARE IN GOOD AGREEMENT WITH THE MAIN PATTERN ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE THAT FLAT FLOW CURRENTLY ABOVE KENTUCKY WILL BECOME MORE NORTHWESTERLY WITH TIME AS RIDGING BUILDS OVER THE SOUTHERN PLAINS INTO FRIDAY MORNING. DURING THIS TRANSITION...WEAK SHORTWAVES WILL RIDE THROUGH KENTUCKY STARTING WITH THE MCVS PASSING TO THE SOUTH THIS AFTERNOON AND TONIGHT. GIVEN THE SMALL SCALE NATURE OF THESE FEATURES WILL FAVOR THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX DETAILS. SENSIBLE WEATHER WILL FEATURE A SMALL CHANCE FOR SHOWERS OR A STRAY THUNDERSTORM ACROSS THE SOUTHERN TIER THROUGH THE EVENING AND INTO THE OVERNIGHT AS THE MINOR MID LEVEL WAVES PASS BY. THE CLOUDS ASSOCIATED WITH THESE SHOULD KEEP THE FOG A BIT MORE LIMITED THROUGH THE NIGHT AND INTO THURSDAY MORNING. THE THREAT OF CONVECTION CONTINUES FOR MUCH OF THE SOUTHERN PARTS OF THE AREA DURING THE DAY THURSDAY...BUT WITH LITTLE IN THE WAY OF SUPPORT FOR ANYTHING BECOMING ORGANIZED OR TOO STRONG. THIS LEADS TO A BETTER CHANCE FOR VALLEY FOG LATER THURSDAY NIGHT AS THE WAVES PULL OUT OF KENTUCKY. TEMPERATURES WILL BE NEAR NORMAL OR A LITTLE ON THE COOL SIDE THROUGH FRIDAY MORNING. USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WINDS INTO TONIGHT AND THEN THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS TO THE LOWS TONIGHT AND THURSDAY NIGHT BASED ON TERRAIN DIFFERENCES AND THE EXPECTATION OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE DRIER MET MOS THAN THE MAV TONIGHT AND THURSDAY WHILE WAS IN LINE WITH THE LOW POP CONSENSUS FOR THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 245 PM EDT WED JUL 22 2015 UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BE ENTRENCHED OVER TEXAS AND THE SOUTHERN PLAINS THROUGH THE PERIOD KEEPING NORTHWEST FLOW IN PLACE ACROSS THE OHIO AND TENNESSEE VALLEYS. DRY HIGH PRESSURE WILL BE IN PLACE AT THE SURFACE FRIDAY AND SATURDAY WITH A DRY AND SEASONABLY WARM AND NOT SO HUMID FORECAST THE RESULT. A SHORTWAVE WILL THEN TRAVERSE THE US/CANADIAN BORDER OVER THE WEEKEND FLATTENING THE RIDGE AND SENDING A WEAK COLD FRONT SOUTHEASTWARD TOWARD OUR REGION. THE FRONT IS EXPECTED TO REMAIN IN THE VICINITY WHILE GRADUALLY WASHING OUT EARLY NEXT WEEK. THIS WILL KEEP A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS IN OUR FORECAST SUNDAY THROUGH WEDNESDAY...WITH COVERAGE LIKELY PEAKING IN THE AFTERNOON AND EARLY EVENING HOURS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 235 PM EDT WED JUL 22 2015 HIGH PRESSURE BUILDING INTO THE AREA HAS HELPED TO CLEAR THE MORNING FOG AND ALSO LIFT THE LOWER CIGS BY EARLY AFTERNOON. A SFC WAVE TRACKING TO OUR SOUTH AND AN APPROACHING MID LEVEL SHORTWAVE COULD BRING A FEW SHOWERS OR A STRAY STORM TO THE WESTERN AND SOUTHERN TAF SITES LATE TONIGHT AND INTO THE DAY ON THURSDAY. ACCORDINGLY...HAVE INCLUDED A VCTS AND CB IN THE SOUTHERN TAFS ALONG WITH LOWERING CIGS FOR THIS TIME. WINDS THROUGH THE PERIOD WILL BE MAINLY LIGHT AND VARIABLE FOR ALL SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...GREIF LONG TERM...ABE AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1257 AM EDT Tue Jul 21 2015 ...Updated Aviation Discussion... ...Forecast Update... Issued at 1200 AM EDT Tue Jul 21 2015 Complex of storms coming in from southeast PAH`s area has quite a bit of lightning with it. Line is transitioning east fairly rapidly, and right on the edge of the outflow, so have a warning out for that line. That line is moving into an area that received rain earlier, so it should become more elevated in nature overtime. Will have to watch for training though in this region. Have additional lines of storms, one near Louisville and southeast, another nearing Madison, IN, and a last one over central Indiana. The latter is decaying and it looks like the focus will be more on the storms over KY the next few hours. Updated pops in the gridded forecast to account for current radar trends and matched obs for the rest of the forecast. Issued at 825 PM EDT Mon Jul 20 2015 Made some minor tweaks to precip chances and hourly temps/dewpts overnight. Overall though the forecast was in good shape. The current line of convection stretching from central IN to southern MO is progged to push eastward through our area between roughly 9pm to 4am. A few cells have popped up in the Bluegrass region also. With decent CAPE/DCAPE values over the region and around 30 kts of bulk shear, storms will pose a damaging wind threat initially. Storms are beginning to become more clustered in nature to our west with an increasing risk for training cells and flash flooding. The best spots for svr convection look to be over south central KY and the Bluegrass where the best bubbles of instability exist. However, instability will be waning as we go through the evening hours. Of greater concern overnight may be the flash flood threat as slow moving storm clusters move through the area. .SHORT TERM (Now through Tuesday Night)... Issued at 315 PM EDT Mon Jul 20 2015 Plenty of debris cloudiness overhead as a result of convection that affected western Kentucky early this morning. Within the last hour we have seen storms develop where the old outflow boundary is interacting with the Cumberland Escarpment, but these storms are already pushing onto the Plateau as we speak. Main challenge is timing and impact of the round, or rounds of storms that could affect mainly central Kentucky through tonight. Even the hi-res models seem to really be struggling from one run to the next, so this is quite a low-confidence forecast. A couple of weak swirls were apparent in visible imagery over southern Illinois and western Kentucky, but even this juicy environment is not responding yet. Earlier HRRR runs have seemed to be the only models with any handle on initial conditions, and have hinted that one round of convection could come through in the hours just before sunset, with others keying on the actual front which would arrive around midnight. Less confident in the SPC slight risk as progged DCAPE is well out of sync with current analysis, and the effective source of lift remains unclear. Best chance is from roughly 22Z to 05Z Tue, but not likely to affect that entire time period. Even with the low-confidence forecast, any storms that do develop could be prolific rain producers due to high precipitable water and storm motion parallel to a nearly stationary boundary. Flash Flood Guidance is quite low especially across the Bluegrass, where 1-hr FFG is 1.5 inches or less in many places. Therefore will continue with the Flash Flood Watch until Tuesday morning, but no extension is planned unless convective trends show themselves more clearly. Whatever organized storms we see should clear the area around midnight or not too long after. Wind shift arrives by mid-morning, but we`ll hang on to high dewpoints and chance POPs through the day as fropa seems to occur in pieces. Mid-level WNW winds picking up to around 30 kt could support a few strong storms with gusty winds over east-central KY, but organized SVR potential is farther north and east as our precip chances will be diminishing as the afternoon progresses. Chance POPs in the middle of the day will be dropping off by mid/late afternoon, with only south central KY in a slight chance for storms for Tue night. Drier air will be filtering in, with dewpoints dropping into the lower/mid 60s and temps dropping to the upper 60s/near 70. .LONG TERM (Wednesday through Monday)... Issued at 300 PM EDT Mon Jul 20 2015 The synoptic pattern at the start of the long term period will feature generally northwest flow across the Ohio Valley, as ridging over the south-central CONUS remains in place. This ridging will actually build NNE into the region by this weekend, bringing a return to the hot and humid conditions. A weak frontal boundary will have pushed into TN at the start of the long term period. There is some discrepancy in the guidance as to how far south this boundary will get, which will be the deciding factor as to whether or not southern KY ends up dry. For now, will continue with slight chance pops across southern KY Wednesday into Thursday as impulses riding along this boundary may be enough to bring precip into the region, but suspect most will end up dry. Given the majority of the region will be on the northern side of the front, temperatures and humidity values will be rather comfortable. Look for highs in the low to mid 80s with dewpoints in the low to mid 60s, perhaps pushing into the upper 60s over southern KY. Heading into Friday and through the upcoming weekend, upper-level ridging will build back into the Ohio Valley which will bring increasing heat and humidity. The region will still be on the periphery of the mid-level westerlies/northwesterlies, so cannot completely rule out thunderstorm chances this weekend. It appears the best chance for a disturbance to impact the region may come Saturday night into Sunday, but confidence in that scenario is quite low and does not warrant any higher mention than just slight chance to chance POPs (20-30%). Otherwise, it will be hot and humid as upper-level ridging builds in and 850mb temps rise back to near 20C. Look for highs back in the upper 80s and lower 90s with heat indices from 95-100 degrees at times. && .AVIATION (06Z TAF Update)... Updated 1255 AM EDT Tue Jul 21 2015 Have showers and storms affecting the terminals over the next few hours. KSDF has the best chance to get out of it sooner, but atmosphere still too juicy to pull it altogether. Also watching to see if storms over central Indiana redevelop. For now, have pulled VCTS for SDF at 7Z, but for all sites go to MVFR conditions in the muggy airmass behind these storms. Should see some improvement as winds shift to northeasterly through the day and cigs lift. Decided to pull mention of showers for the afternoon tomorrow, as probabilities are in the 20-30 percent range for the sites. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH until 8 AM EDT /7 AM CDT/ this morning FOR KYZ029>043-045>049-054>057-065>067-077-078-081-082. IN...FLASH FLOOD WATCH until 8 AM EDT this morning FOR INZ078-079-091- 092. && $$ Updates........RJS/AMS Short Term.....RAS Long Term......KJD Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1202 AM EDT Tue Jul 21 2015 ...Forecast Update... Issued at 1200 AM EDT Tue Jul 21 2015 Complex of storms coming in from southeast PAH`s area has quite a bit of lightning with it. Line is transitioning east fairly rapidly, and right on the edge of the outflow, so have a warning out for that line. That line is moving into an area that received rain earlier, so it should become more elevated in nature overtime. Will have to watch for training though in this region. Have additional lines of storms, one near Louisville and southeast, another nearing Madison, IN, and a last one over central Indiana. The latter is decaying and it looks like the focus will be more on the storms over KY the next few hours. Updated pops in the gridded forecast to account for current radar trends and matched obs for the rest of the forecast. Issued at 825 PM EDT Mon Jul 20 2015 Made some minor tweaks to precip chances and hourly temps/dewpts overnight. Overall though the forecast was in good shape. The current line of convection stretching from central IN to southern MO is progged to push eastward through our area between roughly 9pm to 4am. A few cells have popped up in the Bluegrass region also. With decent CAPE/DCAPE values over the region and around 30 kts of bulk shear, storms will pose a damaging wind threat initially. Storms are beginning to become more clustered in nature to our west with an increasing risk for training cells and flash flooding. The best spots for svr convection look to be over south central KY and the Bluegrass where the best bubbles of instability exist. However, instability will be waning as we go through the evening hours. Of greater concern overnight may be the flash flood threat as slow moving storm clusters move through the area. .SHORT TERM (Now through Tuesday Night)... Issued at 315 PM EDT Mon Jul 20 2015 Plenty of debris cloudiness overhead as a result of convection that affected western Kentucky early this morning. Within the last hour we have seen storms develop where the old outflow boundary is interacting with the Cumberland Escarpment, but these storms are already pushing onto the Plateau as we speak. Main challenge is timing and impact of the round, or rounds of storms that could affect mainly central Kentucky through tonight. Even the hi-res models seem to really be struggling from one run to the next, so this is quite a low-confidence forecast. A couple of weak swirls were apparent in visible imagery over southern Illinois and western Kentucky, but even this juicy environment is not responding yet. Earlier HRRR runs have seemed to be the only models with any handle on initial conditions, and have hinted that one round of convection could come through in the hours just before sunset, with others keying on the actual front which would arrive around midnight. Less confident in the SPC slight risk as progged DCAPE is well out of sync with current analysis, and the effective source of lift remains unclear. Best chance is from roughly 22Z to 05Z Tue, but not likely to affect that entire time period. Even with the low-confidence forecast, any storms that do develop could be prolific rain producers due to high precipitable water and storm motion parallel to a nearly stationary boundary. Flash Flood Guidance is quite low especially across the Bluegrass, where 1-hr FFG is 1.5 inches or less in many places. Therefore will continue with the Flash Flood Watch until Tuesday morning, but no extension is planned unless convective trends show themselves more clearly. Whatever organized storms we see should clear the area around midnight or not too long after. Wind shift arrives by mid-morning, but we`ll hang on to high dewpoints and chance POPs through the day as fropa seems to occur in pieces. Mid-level WNW winds picking up to around 30 kt could support a few strong storms with gusty winds over east-central KY, but organized SVR potential is farther north and east as our precip chances will be diminishing as the afternoon progresses. Chance POPs in the middle of the day will be dropping off by mid/late afternoon, with only south central KY in a slight chance for storms for Tue night. Drier air will be filtering in, with dewpoints dropping into the lower/mid 60s and temps dropping to the upper 60s/near 70. .LONG TERM (Wednesday through Monday)... Issued at 300 PM EDT Mon Jul 20 2015 The synoptic pattern at the start of the long term period will feature generally northwest flow across the Ohio Valley, as ridging over the south-central CONUS remains in place. This ridging will actually build NNE into the region by this weekend, bringing a return to the hot and humid conditions. A weak frontal boundary will have pushed into TN at the start of the long term period. There is some discrepancy in the guidance as to how far south this boundary will get, which will be the deciding factor as to whether or not southern KY ends up dry. For now, will continue with slight chance pops across southern KY Wednesday into Thursday as impulses riding along this boundary may be enough to bring precip into the region, but suspect most will end up dry. Given the majority of the region will be on the northern side of the front, temperatures and humidity values will be rather comfortable. Look for highs in the low to mid 80s with dewpoints in the low to mid 60s, perhaps pushing into the upper 60s over southern KY. Heading into Friday and through the upcoming weekend, upper-level ridging will build back into the Ohio Valley which will bring increasing heat and humidity. The region will still be on the periphery of the mid-level westerlies/northwesterlies, so cannot completely rule out thunderstorm chances this weekend. It appears the best chance for a disturbance to impact the region may come Saturday night into Sunday, but confidence in that scenario is quite low and does not warrant any higher mention than just slight chance to chance POPs (20-30%). Otherwise, it will be hot and humid as upper-level ridging builds in and 850mb temps rise back to near 20C. Look for highs back in the upper 80s and lower 90s with heat indices from 95-100 degrees at times. && .AVIATION (00Z TAF Update)... Updated 720 PM EDT Mon Jul 20 2015 The main TAF updates with this package are delaying the timing of t-storms this evening and adding an MVFR group for tomorrow morning. A broken line of convection was firing to our west from central IN to southern MO as of 23Z. Expect this line to continue to move east through the evening hours. The latest SPC HRRR has a good handle on the line so used that model for timing. This should put the best t-storm chances at SDF/BWG between 2-7Z and at LEX between 4-9Z respectively. Since it is a broken line and strength/coverage of storms is expected to wane a bit by late evening, still went with VCTS at all TAF sites. Will need to amend with predominant t-storms and reduced flight conditions if the storms hold together. After the convection moves through tonight, we should see a period of MVFR flight conditions before a sfc front moves through between 13-15Z. The front will shift winds from WSW to NW. After the front passes, low clouds should scour out and lift. Late in the day tomorrow a second sfc boundary will approach the region bringing isolated convection. Will include a VCSH to account for this late in the TAF period. This front will shift winds from NW to N at the end of the TAF period or just beyond. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH until 8 AM EDT /7 AM CDT/ this morning FOR KYZ029>043-045>049-054>057-065>067-077-078-081-082. IN...FLASH FLOOD WATCH until 8 AM EDT this morning FOR INZ078-079-091- 092. && $$ Updates........RJS/AMS Short Term.....RAS Long Term......KJD Aviation.......AMS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
623 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TONIGHT. AN UPPER LEVEL TROUGH WILL SWING ACROSS THE REGION ON WEDNESDAY WITH ANOTHER FRONTAL BOUNDARY FOR THURSDAY. && .NEAR TERM /THROUGH WEDNESDAY/... 623 PM UPDATE...A LINE OF SHOWERS AND THUNDERSTORMS AHEAD OF A COLD FRONT WILL SWEEP EAST ACROSS NORTHERN MAINE THIS EVENING. THE MAIN THREATS ARE DANGEROUS CLOUD TO GROUND LIGHTNING AND TORRENTIAL DOWNPOURS OF RAIN. THE KCBW 88-D INDICATED RAINFALL AMOUNTS IN EXCESS OF 4 INCHES IN A SMALL AREA WEST OF ALLAGASH. THE ESTCOURT STATION GAGE REPORTED 0.73" FROM 5-6 PM AND THIS WAS NOT FAR FROM THE LEGACY RADAR ESTIMATES. THE DUAL POL ACTUALLY UNDERESTIMATED THE RAINFALL AMOUNTS. SUSPECT THERE IS AT LEAST SOME HAIL CONTAMINATION...BUT IN ANY EVENT AN INCH OR TWO OF RAIN IS POSSIBLE IN AN HOUR UNDER THE HEAVIEST OF THE THUNDERSTORMS. THE GOOD NEWS...THE STORMS ARE NOT EXPECTED TO PRODUCE LARGE HAIL OR DAMAGING WIND. AS THE ACTIVITY MOVES EAST IT IS MOVING INTO A MUCH MORE STABLE ENVIORNMENT AND THE ACTIVITY SHOULD WEAKEN THIS EVENING. ONLY MINOR UPDATES BASED ON THE LATEST RADAR TRENDS. PREVIOUS DISCUSSION... SCATTERED THUNDERSTORMS EXPECTED INTOTONIGHT W/HEAVY RAINFALL POTENTIAL AND CLOUD TO GROUND LIGHTNING. SOME STRONGER STORMS COULD CONTAIN BRIEF WIND GUSTS ESPECIALLY W/THE ARRIVAL OF THE COLD FRONT LATER THIS EVENING. SPC UPDATED THE DAY1 OUTLOOK W/A MARIGNAL RISK FOR WESTERN MAINE THROUGH THE EVENING. THE MAIN ACTION ATTM WAS ACROSS FAR WNW MAINE W/TRAINING CELLS AND VERY HEAVY RAINFALL PER THE LATEST RADAR LOOP. RADAR ESTIMATES OF UP TO 2"/HR IN THE STRONGER CELLS. CELLS MOVING ALONG THE UPPER SW FLOW ALLOWING FOR RE-GENERATION OF THE STORMS AND THEREFORE HEAVY RAINFALL POTENTIAL. PWATS IN THIS REGION UP AROUND 1.5 INCHES W/GOOD MOISTURE TRANSPORT FROM 925-850MBS PER THE LATEST MESO- ANALYSIS. THIS ACTIVITY WAS IGNITING ALONG A PRE- FRONTAL TROF WELL FORECASTED BY THE MIDNIGHT CREW. LOCALIZED FLOODING POSSIBLE IN THIS AREA. FURTHER E, ATMOSPHERE MORE STABLE THANKS TO A SSE FLOW AND CLOUD COVER LIMITING HEATING. ACTIVITY TO THE W IS FORECAST TO BREAK UP AS IT PUSHES E INTO THE EVENING. ANOTHER ORGANIZED LINE OF CONVECTION IS SHOWN BY MESOSCALE GUIDANCE INCLUDING THE NAM12 AND HRRR 3KM MODEL TO MOVING ACROSS THE NORTHERN 1/2 OF THE CWA THIS EVENING INTO EARLY TONIGHT. THIS ACTION WILL BE IN ASSOCIATION W/THE MAIN COLD FRONT. SOUNDING PROFILES NOT OVERLY IMPRESSIVE FOR STRONG CONVECTION, BUT MUCAPES OF 600+ JOULES AND COLUMN MOISTENING UP THROUGH 700MBS LATER THIS EVENING PLUS INCREASING MID LEVEL SHEAR WILL ALLOW FOR SOME DECENT SHOWERS/STORMS. AGAIN, HEAVY RAINFALL AND LIGHTNING THE MAIN THREAT. DECIDED TO GO W/BASIN QPF OF 1.25+ INCHES THROUGH WEST AND NORTHWEST MAINE THROUGH MIDNIGHT DUE TO THE TRAINING CELLS. ALL ACTION WILL WEAKEN AND PUSH TO THE ESE LATER TONIGHT W/COOLER AND DRIER AIR BEHIND THE FRONT BY WEDNESDAY MORNING. DECIDED TO ADD FOG INTO THE FORECAST TONIGHT BEFORE THE FROPA W/DEEP LLVL MOISTURE IN PLACE. DOWNEAST AND THE COAST WILL HAVE THE BEST SHOT AS SEEING THE FOG. UNSETTLED ON WEDNESDAY W/THE UPPER TROF AXIS FORECAST TO ACROSS THE REGION. BEST MOISTURE AVAILABLE LOOKS TO BE IN THE LLVLS AROUND 850MBS. SOME INSTABILITY IS THERE BUT MARGINAL AND LOW/MID LEVEL LAPSE RATES ARE WEAK. THEREFORE, DECIDED TO LEAN AWAY FROM THE MENTION OF TSTMS AND KEPT JUST SHOWERS ATTM. LATER CREWS CAN ASSESS THIS FURTHER W/THE LATEST GUIDANCE. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL FOR JULY. .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... THE REGION IS EXPECTED TO REMAIN IN A CYCLONIC FLOW ON THE BACK SIDE OF SURFACE LOW PRESSURE LOCATED TO THE EAST OF NOVA SCOTIA ALONG WITH AN UPPER LEVEL SYSTEM TO THE NORTHWEST. IN ADDITION THE UPPER LEVEL SYSTEM IS EXPECTED TO MOVE SOUTHEAST WARD AND CROSS OVER THE NORTHERN AND EASTERN PORTION OF MAINE FRIDAY. THIS IS EXPECTED TO RESULT IN SHOWERS... ESPECIALLY IN THE NORTH AND DURING DAYLIGHT HOURS. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND SKY. FOR MAXIMUM TEMPERATURE WILL USE THE CONSENSUS RAW. FOR MINIMUM TEMPERATURE HAVE USED THE CONSENSUS ALL. WILL USE THE MOSG25 FOR WINDS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN UPPER LOW WILL PULL AWAY FROM NEW ENGLAND FRIDAY NIGHT INTO SATURDAY, FOLLOWED BY A VERY BRIEF RIDGE OF HIGH PRESSURE. AS SUCH, THE FIRST PART OF THE WEEKEND WILL HAVE THE LOWEST CHANCES FOR RAIN, THOUGH A FEW SHOWERS CAN`T BE TOTALLY RULED OUT, ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE NORTHWEST. A SLOW- MOVING FRONTAL SYSTEM WILL THEN DRAG ITS ATTENDANT FRONT ACROSS THE GREAT LAKES AND THE NORTHEASTERN CONUS SUNDAY AND MONDAY, BRINGING A PROLONGED PERIOD OF SHOWERS AND POSSIBLE THUNDERSTORMS. THE UPPER LOW ASSOCIATED WITH THIS SYSTEM WILL THEN BRING MORE SCATTERED SHOWERS TO THE REGION ON TUESDAY. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... NEAR TERM: MVFR TO IFR TONIGHT W/SHOWERS AND TSTMS. THE BEST TSTM ACTIVITY WILL BE N OF KBGR AND KBHB. FOG WILL BE A THREAT FOR KBGR AND KBHB LATER TONIGHT INTO EARLY WEDNESDAY. COLD FROPA WEDNESDAY MORNING W/CONDITIONS IMPROVING TO VFR BY MIDDAY. THE CAVEAT TO THIS WILL BE ACROSS THE NORTHERN TERMINALS AS CIGS COULD DROP TO MVFR FOR A PERIOD WEDNESDAY AFTERNOON. SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THEN MVFR/VFR CONDITIONS THURSDAY THROUGH FRIDAY. && .MARINE... NEAR TERM: FOG KEEPING NAVIGATION TRICKY W/VSBYS BELOW 1 NM. KEPT FOG THROUGH MIDDAY WEDNESDAY UNTIL GOOD MIXING W/WINDS VEERING TO THE W ALLOWING FOR CLEARING. BROUGHT WINDS UP TO 10-15KT WEDNESDAY MORNING BEHIND THE FRONT. WAVE HEIGHTS TO BE NO MORE THAN 3 FT AND THIS WILL BE MAINLY OVER THE OUTER WATERS. SHORT TERM: FOR SUSTAINED WINDS HAVE USED A 50/50 BLEND OF THE NAM12 AND GFS40. FOR WAVES: WITH LIGHT WINDS EXPECTED WEDNESDAY NIGHT THROUGH FRIDAY THE PRIMARY WAVE SYSTEMS WILL BE COMPOSED OF LONG PERIOD WAVE GROUPS COMBINING TO PRODUCE 1 TO 2 FOOT SEAS. THE COMBINED SEAS COMPOSED OF SOUTHERLY 6 SECOND GROUP AND SOUTHEASTERLY 9-10 SECOND GROUP. WILL USE THE NEAR SHORE WAVE MODEL TO POPULATE WAVE HEIGHT GRIDS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...CB/HEWITT SHORT TERM...MIGNONE LONG TERM...HASTINGS AVIATION...CB/HEWITT/MIGNONE MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
418 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TONIGHT. AN UPPER LEVEL TROUGH WILL SWING ACROSS THE REGION ON WEDNESDAY WITH ANOTHER FRONTAL BOUNDARY FOR THURSDAY. && .NEAR TERM /THROUGH WEDNESDAY/... SCATTERED THUNDERSTORMS EXPECTED INTO TONIGHT W/HEAVY RAINFALL POTENTIAL AND CLOUD TO GROUND LIGHTNING. SOME STRONGER STORMS COULD CONTAIN BRIEF WIND GUSTS ESPECIALLY W/THE ARRIVAL OF THE COLD FRONT LATER THIS EVENING. SPC UPDATED THE DAY1 OUTLOOK W/A MARIGNAL RISK FOR WESTERN MAINE THROUGH THE EVENING. THE MAIN ACTION ATTM WAS ACROSS FAR WNW MAINE W/TRAINING CELLS AND VERY HEAVY RAINFALL PER THE LATEST RADAR LOOP. RADAR ESTIMATES OF UP TO 2"/HR IN THE STRONGER CELLS. CELLS MOVING ALONG THE UPPER SW FLOW ALLOWING FOR RE-GENERATION OF THE STORMS AND THEREFORE HEAVY RAINFALL POTENTIAL. PWATS IN THIS REGION UP AROUND 1.5 INCHES W/GOOD MOISTURE TRANSPORT FROM 925-850MBS PER THE LATEST MESO- ANALYSIS. THIS ACTIVITY WAS IGNITING ALONG A PRE- FRONTAL TROF WELL FORECASTED BY THE MIDNIGHT CREW. LOCALIZED FLOODING POSSIBLE IN THIS AREA. FURTHER E, ATMOSPHERE MORE STABLE THANKS TO A SSE FLOW AND CLOUD COVER LIMITING HEATING. ACTIVITY TO THE W IS FORECAST TO BREAK UP AS IT PUSHES E INTO THE EVENING. ANOTHER ORGANIZED LINE OF CONVECTION IS SHOWN BY MESOSCALE GUIDANCE INCLUDING THE NAM12 AND HRRR 3KM MODEL TO MOVING ACROSS THE NORTHERN 1/2 OF THE CWA THIS EVENING INTO EARLY TONIGHT. THIS ACTION WILL BE IN ASSOCIATION W/THE MAIN COLD FRONT. SOUNDING PROFILES NOT OVERLY IMPRESSIVE FOR STRONG CONVECTION, BUT MUCAPES OF 600+ JOULES AND COLUMN MOISTENING UP THROUGH 700MBS LATER THIS EVENING PLUS INCREASING MID LEVEL SHEAR WILL ALLOW FOR SOME DECENT SHOWERS/STORMS. AGAIN, HEAVY RAINFALL AND LIGHTNING THE MAIN THREAT. DECIDED TO GO W/BASIN QPF OF 1.25+ INCHES THROUGH WEST AND NORTHWEST MAINE THROUGH MIDNIGHT DUE TO THE TRAINING CELLS. ALL ACTION WILL WEAKEN AND PUSH TO THE ESE LATER TONIGHT W/COOLER AND DRIER AIR BEHIND THE FRONT BY WEDNESDAY MORNING. DECIDED TO ADD FOG INTO THE FORECAST TONIGHT BEFORE THE FROPA W/DEEP LLVL MOISTURE IN PLACE. DOWNEAST AND THE COAST WILL HAVE THE BEST SHOT AS SEEING THE FOG. UNSETTLED ON WEDNESDAY W/THE UPPER TROF AXIS FORECAST TO ACROSS THE REGION. BEST MOISTURE AVAILABLE LOOKS TO BE IN THE LLVLS AROUND 850MBS. SOME INSTABILITY IS THERE BUT MARGINAL AND LOW/MID LEVEL LAPSE RATES ARE WEAK. THEREFORE, DECIDED TO LEAN AWAY FROM THE MENTION OF TSTMS AND KEPT JUST SHOWERS ATTM. LATER CREWS CAN ASSESS THIS FURTHER W/THE LATEST GUIDANCE. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL FOR JULY. .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... THE REGION IS EXPECTED TO REMAIN IN A CYCLONIC FLOW ON THE BACK SIDE OF SURFACE LOW PRESSURE LOCATED TO THE EAST OF NOVA SCOTIA ALONG WITH AN UPPER LEVEL SYSTEM TO THE NORTHWEST. IN ADDITION THE UPPER LEVEL SYSTEM IS EXPECTED TO MOVE SOUTHEAST WARD AND CROSS OVER THE NORTHERN AND EASTERN PORTION OF MAINE FRIDAY. THIS IS EXPECTED TO RESULT IN SHOWERS... ESPECIALLY IN THE NORTH AND DURING DAYLIGHT HOURS. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND SKY. FOR MAXIMUM TEMPERATURE WILL USE THE CONSENSUS RAW. FOR MINIMUM TEMPERATURE HAVE USED THE CONSENSUS ALL. WILL USE THE MOSG25 FOR WINDS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN UPPER LOW WILL PULL AWAY FROM NEW ENGLAND FRIDAY NIGHT INTO SATURDAY, FOLLOWED BY A VERY BRIEF RIDGE OF HIGH PRESSURE. AS SUCH, THE FIRST PART OF THE WEEKEND WILL HAVE THE LOWEST CHANCES FOR RAIN, THOUGH A FEW SHOWERS CAN`T BE TOTALLY RULED OUT, ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE NORTHWEST. A SLOW- MOVING FRONTAL SYSTEM WILL THEN DRAG ITS ATTENDANT FRONT ACROSS THE GREAT LAKES AND THE NORTHEASTERN CONUS SUNDAY AND MONDAY, BRINGING A PROLONGED PERIOD OF SHOWERS AND POSSIBLE THUNDERSTORMS. THE UPPER LOW ASSOCIATED WITH THIS SYSTEM WILL THEN BRING MORE SCATTERED SHOWERS TO THE REGION ON TUESDAY. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... NEAR TERM: MVFR TO IFR TONIGHT W/SHOWERS AND TSTMS. THE BEST TSTM ACTIVITY WILL BE N OF KBGR AND KBHB. FOG WILL BE A THREAT FOR KBGR AND KBHB LATER TONIGHT INTO EARLY WEDNESDAY. COLD FROPA WEDNESDAY MORNING W/CONDITIONS IMPROVING TO VFR BY MIDDAY. THE CAVEAT TO THIS WILL BE ACROSS THE NORTHERN TERMINALS AS CIGS COULD DROP TO MVFR FOR A PERIOD WEDNESDAY AFTERNOON. SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THEN MVFR/VFR CONDITIONS THURSDAY THROUGH FRIDAY. && .MARINE... NEAR TERM: FOG KEEPING NAVIGATION TRICKY W/VSBYS BELOW 1 NM. KEPT FOG THROUGH MIDDAY WEDNESDAY UNTIL GOOD MIXING W/WINDS VEERING TO THE W ALLOWING FOR CLEARING. BROUGHT WINDS UP TO 10-15KT WEDNESDAY MORNING BEHIND THE FRONT. WAVE HEIGHTS TO BE NO MORE THAN 3 FT AND THIS WILL BE MAINLY OVER THE OUTER WATERS. SHORT TERM: FOR SUSTAINED WINDS HAVE USED A 50/50 BLEND OF THE NAM12 AND GFS40. FOR WAVES: WITH LIGHT WINDS EXPECTED WEDNESDAY NIGHT THROUGH FRIDAY THE PRIMARY WAVE SYSTEMS WILL BE COMPOSED OF LONG PERIOD WAVE GROUPS COMBINING TO PRODUCE 1 TO 2 FOOT SEAS. THE COMBINED SEAS COMPOSED OF SOUTHERLY 6 SECOND GROUP AND SOUTHEASTERLY 9-10 SECOND GROUP. WILL USE THE NEAR SHORE WAVE MODEL TO POPULATE WAVE HEIGHT GRIDS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT SHORT TERM...MIGNONE LONG TERM...HASTINGS AVIATION...HEWITT/MIGNONE MARINE...HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
933 AM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT WILL APPROACH THIS AFTERNOON AND CROSS THE AREA THIS EVENING. AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL REMAIN OVER THE REGION THROUGH THE END OF THE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... 920 AM UPDATE...SLOWED THE TIMING OF OF THE ORGANIZED SHOWERS AND STORMS BY 3 HRS USING THE HRRR 3KM MODEL TO INITIALIZE. VISIBLE SATELLITE IMAGERY SHOWED CLEARING BACK ACROSS WESTERN AREAS WHILE EASTERN AREAS WERE CLOUDED OVER KEEPING THINGS STABLE. PRE-FRONTAL TROF AHEAD THE COLD FRONT WILL KICK OFF SOME SCATTERED SHOWERS AND PERHAPS A FEW TSTMS BASED ON THE BEST INSTABILITY DUE TO AVAILABLE HEATING. LAPS DATA SHOWED THE FAR WESTERN AREAS ALREADY DESTABILIZING W/LIS DOWN TO -2. KEPT SOME FOG ACROSS THE DOWNEAST COAST THROUGH LATE MORNING. AS THE COLD FRONT SLIDES EAST THIS AFTN, EXPECT SHOWERS TO INCREASE IN COVERAGE WITH CONVECTION DVLPNG AS AIRMASS DESTABILIZES. MODELS INDICATING A PRE-FRONTAL TROF WL DVLP THIS AFTN ACRS THE ALLAGASH AND SLIDE THRU NRN MAINE LATE THIS AFTN AND EVNG. AIRMASS PROGGED TO DESTABILIZE AS TEMPS WARM INTO THE 70S WITH TDS IN THE 60S. H7-H5 LR EXPECTED TO BE BTWN 6.0-6.5 C/KM AFT 18Z MAINLY ACRS FAR NW ZONES. GIVEN EXTENSIVE LOW CLDS THRU THE MRNG, HTG WL BE LIMITED WITH MLCAPES CAPPED RIGHT AROUND 600 J/KG. 0-6KM BULK SHEAR VALUES DRG THE AFTN PROGGED TO BE ARND 25KTS WITH VALUES NOT INCREASING UNTIL AFT FROPA OCCURS. TIMING LOOKS TO BE OFF FOR ANY SVR THREAT WHICH GOES ALONG WITH SPC`S DAY1 OUTLOOK. WL TONE DOWN WORDING IN HWO FOR TDA AND JUST MENTION STRONG STORMS WITH POTENTIALLY HVY RAINFALL. FOR TONIGHT, FRONT MVS THRU CWA BY 12Z WED. EXPECT LINE OF STORMS TO GRADUALLY DIMINISH THRU MIDNIGHT WITH JUST LEFT-OVR SHOWERS BHND. FRONT WL TAKE AWHILE TO CLR WATERS LEAVING AREA OF FOG IN PRETTY MUCH ALL NIGHT ONCE IT SETS BACK IN AFT 04Z, WHICH HAS BEEN THE CASE THE LAST FEW NIGHTS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... A COLD FRONT WILL BE MOVING AWAY TO THE EAST ON WEDNESDAY AS A CORRIDOR OR DRY AIR MOVES ACROSS THE AREA BRINGING PARTIAL SUNSHINE. THE SUNSHINE MAY PROVIDE ENOUGH INSTABILITY FOR A STRAY SHOWER OR THUNDERSHOWER, MAINLY ACROSS THE NORTH, WEDNESDAY AFTERNOON. A COOL TROUGH OF LOW PRESSURE OVER QUEBEC WILL THEN BEGIN TO DROP INTO THE AREA LATE WEDNESDAY NIGHT INTO THURSDAY. THIS WILL BRING MOSTLY CLOUDY AND COOLER CONDITIONS WITH A GOOD CHANCE FOR SHOWERS ACROSS THE NORTH, MAINLY THURSDAY. HIGHS THURSDAY WILL AVERAGE ABOUT TEN DEGREES BELOW NORMAL ACROSS THE AREA AS THE COMBINATION OF SURFACE LOW PRESSURE TO THE EAST AND UPPER LEVEL LOW PRESSURE ALOFT PULLS COOL AIR DOWN FROM CANADA. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL MAINTAIN COOL AND CLOUDY CONDITIONS FRIDAY INTO EARLY SATURDAY. SKIES MAY BRIGHTEN LATER SATURDAY AS THE TROUGH SLIDES OFF TO THE EAST AND A RIDGE OF HIGH PRESSURE BEGINS BUILDING INTO THE REGION. THIS MAY BRING A MOSTLY CLEAR NIGHT SATURDAY NIGHT WITH PATCHY FOG LATE. A FAST MOVING TROUGH OF LOW PRESSURE WILL THEN APPROACH ON SUNDAY BRINGING CLOUDY CONDITIONS AGAIN WITH A CHANCE FOR SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS. GENERALLY COOL CONDITIONS WILL LIKELY PERSIST INTO EARLY NEXT WEEK AS AN AMPLIFIED PATTERN MAINTAINS A TROUGH OVER THE NORTHEAST. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... NEAR TERM: LOW MVFR/IFR EXPECTED THROUGH THE DAY. COLD FRONT WILL RACE THROUGH DURING THE AFTERNOON AND EVENING, POSSIBLY BRINGING STORMS WITH GUSTY/VRB WINDS. SHOWERS EXPECTED BEHIND FRONTAL BNDRY WITH IFR CIGS SETTING IN THROUGH END OF TAF VALID TIME. SHORT TERM: CONDITIONS WILL LIKELY BECOME VFR WEDNESDAY THEN MAY DROP TO MVFR WEDNESDAY NIGHT ACROSS THE NORTH. MVFR CONDITIONS ACROSS THE NORTH AND VFR CONDITIONS DOWNEAST ARE LIKELY THURSDAY INTO THURSDAY NIGHT THEN MVFR CONDITIONS ARE LIKELY THROUGHOUT THE AREA ON FRIDAY. CONDITIONS SHOULD IMPROVE TO VFR ON SATURDAY. && .MARINE... NEAR TERM: AREAS OF FOG WILL AFFECT THE WATERS THROUGH WED MORNING BEFORE A COLD FRONT PASSES. SEAS AND WINDS WILL REMAIN BELOW SMALL CRAFT CRITERIA THROUGH WED. SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA ACROSS THE AREA THIS WEEK. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
905 PM EDT WED JUL 22 2015 .SYNOPSIS... HIGH PRESSURE REMAINS OVER THE REGION THROUGH SATURDAY. A COLD FRONT MOVES IN FROM THE NORTHWEST LATER SUNDAY AND MONDAY. THE FRONT MAY STALL OUT OVER THE REGION ON TUESDAY. && .NEAR TERM /THROUGH THURSDAY NIGHT/... SFC HIGH PRESSURE BUILDING IN FROM THE WEST COMBINING WITH NEAR ZONAL FLOW ALOFT WILL LEAD TO DRY AND QUIET CONDITIONS THRU THURS MORNING. 23Z HRRR HINTING OF LIGHT PCPN OVER SOUTHERN MD 08-10Z WHILE BOTH THE HI RES ARW AND NMM SHOWS PCPN AT THE SAME TIME BUT DUE EAST OVER EASTERN MD. ABV MODELS INDICATING WEAK SFC CONVERGENCE WITH A TROUGH EXTENDING ACROSS THE REGION...WHILE LATEST WATER VAPOR SHOWS PSBL WEAK VORT MAX COULD MOVE THRU AROUND THAT TIME. THINKING AIR MASS TOO DRY AT THE SFC TO RESULT IN ANY PCPN...BUT CAN NOT RULE OUT A STRAY SHOWER. A WEAK SHORTWAVE ALONG THE UPPER FLOW KEEPING SCT- BKN SKIES NEAR THE MASON- DIXON...WITH CLEARING SKIES THRU THE REMAINDER OF THE CWA. WEAKENING PRESSURE GRADIENT AND LACK OF MIXING ALLOWING FOR LIGHT NW FLOW. CONTINUING CAA WILL DROP LOWS TONIGHT TO SLIGHTLY BELOW NORMAL. WK SFC LOPRES SHUD BE TRAVERSING THE FRNTL BNDRY THU AFTN-EVNG. GFS A BIT FURTHER N THAN NAM. STILL SHUDNT IMPACT CWFA DIRECTLY EITHER WAY...BASED ON CURRENT SOLNS. HV KEPT POPS/WX DRY...BUT THE GRADIENT LURKS JUST SE OF CWFA. IF LATER SOLNS TREND NWD...MAY NEED TO ADD POPS TO SERN CWFA. OTRW...MOSUN SKIES WL PREVAIL AS SFC-H8 RDG WL REMAIN NW OF CWFA PROVIDING SUBSIDENCE. H8 TEMPS REMAIN SIMLR THRU THE PD...AND WL DO LIKEWISE FOR MAXT AND MIN-T FCSTS. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... HIGH PRESSURE OVER THE OHIO VALLEY WILL DOMINATE CONDITIONS ON FRI WITH MOSTLY SUNNY SKIES AND NW FLOW... ALLOWING FOR TEMPS SLIGHTLY BELOW NORMAL OVER OUR REGION. COOLER- THAN-NORMAL CONDITIONS WILL CONTINUE INTO FRI NIGHT WITH NW FLOW AND LOW HUMIDITY. HIGH PRESSURE MOVES OFFSHORE SAT AND THE FLOW WILL TURN MORE SOUTHERLY... BRINGING AN INCREASE IN HUMIDITY AND TEMPS THAT ARE CLOSER TO NORMAL. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE FROM NEW ENGLAND TO THE MID ATLANTIC COAST WILL PROMOTE DRY CONDITIONS WITH SEASONABLE TEMPERATURES SATURDAY NIGHT. AN UPPER LEVEL TROUGH OF LOW PRESSURE AND ITS AFFILIATED SURFACE COOL FRONT WILL PUSH ACROSS THE MID ATLANTIC REGION SUNDAY INTO SUNDAY NIGHT...BRINGING A CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS. THE BEST CHANCE DURING THE DAY SUNDAY WILL BE IN THE POTOMAC HIGHLANDS AND THE SHENANDOAH VALLEY WITH THE CHANCE EXTENDING EASTWARD TO THE I-95 CORRIDOR AND CHESAPEAKE BAY SUNDAY NIGHT. THE COOL FRONT SHOULD STALL ACROSS SOUTHERN MARYLAND AND CENTRAL VIRGINIA MONDAY AND MONDAY NIGHT...ALLOWING FOR THE CHANCE OF SHOWERS AND THUNDERSTORMS TO LINGER. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WOULD BE MAINLY SOUTHERN MARYLAND AND CENTRAL VIRGINIA...ALTHOUGH THERE IS A SLIGHT CHANCE AS FAR NORTH AND WEST AS THE POTOMAC HIGHLANDS. WEAK HIGH PRESSURE...BOTH AT THE SURFACE AND AT THE MID LEVELS...WILL ATTEMPT TO BUILD IN FROM THE WEST TUESDAY AND TUESDAY NIGHT. WE`LL KEEP A CHANCE FOR SHOWERS AND A THUNDERSTORM OR TWO IN THE REGION AS WE COULD BE PINNED BETWEEN A DISSIPATING FRONT TO OUR SOUTH AND SOME LOW PRESSURE ENERGY MOVING ACROSS OHIO AND PENNSYLVANIA. THE HIGH DOESN`T APPEAR TO BE STRONG. THROUGH THE DAY WEDNESDAY...WEAK HIGH PRESSURE SHOULD HOLD ONTO THE REGION AND FOR THE MOST PART MOST PLACES WILL BE DRY. HOWEVER...A PERSISTENT ZONAL FLOW WITH WEAK INTERMITTENT SHORTWAVES OF ENERGY COULD SPAWN A FEW SHOWERS OR A RUMBLE OF THUNDER...MAINLY IN THE MOUNTAINS. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... VFR FOR THE TAF PERIOD. NW FLOW GENERALLY LESS THAN 10 KTS. VFR CONDITIONS CONTINUE FRI THRU THE WEEKEND. && .MARINE... SUB-SCA CONDITIONS EXPECTED THRU SAT. SMALL CRAFT ADVISORIES ARE POSSIBLE SUNDAY...MAINLY DURING THE AFTERNOON...AS WINDS COULD GUST OVER 20 KNOTS AT TIMES. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...HTS NEAR TERM...SEARS/HTS SHORT TERM...IMR LONG TERM...KLW AVIATION...SEARS MARINE...SEARS/KLW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
146 PM EDT TUE JUL 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 351 AM EDT TUE JUL 21 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT OVER THE UPR LKS BTWN CLOSED LO NEAR JAMES BAY AND UPR RDG OVER THE ROCKIES/WRN PLAINS. A DISTURBANCE DROPPING SEWD THRU NW ONTARIO IN CONCERT WITH SOME MSTR IN THE H85-7 LYR SHOWN ON THE 00Z INL/YPL RAOBS IS BRINGING SCT-BKN AC THRU MUCH OF NW ONTARIO...NRN MN AND LK SUP. FARTHER TO THE W IN MANITOBA CLOSER TO THE UPR RDG AXIS AND UNDER STRONGER DEEP LYR QVECTOR DVGC...THE 00Z THE PAS RAOB AT THE NRN END OF LK WINNIPEG SHOWS A MUCH SHARPER MID LVL INVRN. SKIES IN THIS AREA ARE MOCLR. DESPITE SOME RELATIVELY DRY LLVL AIR AND LLVL CAA...STEADY NW WINDS UNDER SHARPER PRES GRADIENT WELL E OF HI PRES CENTER IN THE NRN PLAINS HAS LIMITED THE DIURNAL TEMP DROP. RELATIVELY QUIET QUIET WX WL DOMINATE THE SHORT TERM. MAIN FCST CONCERNS FOCUS ON CLD TRENDS TODAY AND TEMPS TODAY/TNGT. TODAY...SHRTWV DIGGING SEWD THRU NW ONTARIO IS FCST TO BE OVER NE LK SUP BY 12Z AND THEN OVER SE ONTARIO BY 00Z THIS EVNG...WITH DNVA/ SHARPER DEEP LYR QVECTOR OVER THE UPR LKS IN ITS WAKE BRINGING 12HR H5 HGT RISES UP TO 50M IN ITS WAKE. EXPECT SCT-BKN CU TO DEVELOP BY LATE MRNG WITH DAYTIME HEATING UNDER H85 THERMAL TROF/LINGERING MSTR...BUT TENDENCY DURING THE AFTN SHOULD BE FOR THE CU TO SCT OUT WITH SHARPENING SUBSIDENCE INVRN/ARRIVAL OF DRIER AIR SHOWN ON THE PAS RAOB. SOME OF THE HI RES MODELS EVEN GENERATE SOME ISOLD SHOWERS OVER THE ECNTRL CWA TOWARD NOON...BUT WL MAINTAIN DRY FCST FOR NOW GIVEN RELATIVELY STABLE MID LYRS SHOWN ON THE UPSTREAM RAOBS/FCST SDNGS. WINDS MAY ALSO GET A BIT GUSTY AGAIN THIS MRNG UNDER SHARPER PRES GRADIENT/STEEPENING LLVL LAPSE RATES...BUT SFC HI PRES MOVING OVER THE CWA IN THE AFTN SHOULD RESULT IN DIMINISHING WINDS. THE MORE PERSISTENT GUSTY WINDS WL BE OVER THE E...WHERE THE TIGHTER GRADIENT WL LINGER LONGER AND LK BREEZE COMPONENT OFF LK SUP WL ACCENTUATE THIS FLOW. EXPECT THE LOWEST MAX TEMPS IN THIS AREA AS WELL WITH MORE LK SUP MODERATION. LOCATIONS NEAR THE SHORE E OF MQT WL SEE HI TEMPS HOLDING IN THE 60S. AS H85 TEMPS REBOUND TO NEAR 12Z ALONG THE WI BORDER LATER IN THE DAY...THE MERCURY SHOULD RISE WELL INTO THE 70S AND AT LEAST APRCH 80 AT A FEW LOCATIONS OVER THE SCENTRAL WITH DOWNSLOPE FLOW AND LIMITED LK BREEZE OFF LK MI. TNGT...EXPECT LINGERING CU TO DSPT EARLY AND GIVE WAY TO MOCLR SKIES UNDER LARGER SCALE SUBSIDENCE/LOSS OF DAYTIME HEATING. LO TEMPS WL BE COOLEST OVER THE W CLOSER TO SFC HI PRES RDG AXIS APRCHG WRN LK SUP/WEAKER PRES GRADIENT. THE COOL SPOTS MAY SEE THE THERMOMETER READ AS LO AS 45 BY DAYBREAK. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 350 AM EDT TUE JUL 21 2015 IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE. POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION LATE FRI INTO SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT. MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER THU AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE W...WHICH MAINLY INCREASES MID LEVEL MOISTURE ENOUGH TO ALLOW FOR WEAK CONVECTIVE POTENTIAL. MODELS ARE SLOWER WITH THE FRONT THAN THEY WERE YESTERDAY...SO WILL CONTINUE TREND OF LOWERING DEW POINTS ON WED AFTERNOON...BUT FIRE WEATHER CONCERNS WILL BE MINIMAL GIVEN LIGHT WINDS. WILL KEEP SLIGHT CHANCE POPS INTO AREAS ALONG THE WI BORDER THU. THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES BETWEEN MODELS WITH THIS SYSTEM...WITH THE 00Z/21 GFS BEING STRONGER AND FARTHER S THAN THE 12Z/20 ECMWF. WILL USE CONSENSUS GUIDANCE GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH SAT. SUN LOOKS DRY FOR NOW. DEPENDING ON TIMING AND OTHER FACTORS...COULD SEE INGREDIENTS COME TOGETHER FOR SOME STRONG TO SEVERE STORMS MAINLY S OF THE CWA. SUN LOOKS DRY AND MON MAY SEE SOME RAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 145 PM EDT TUE JUL 21 2015 SCT-BKN VFR CUMULUS AND STRATOCUMULUS CLOUDS WILL AFFECT MAINLY KIWD AND KSAW REST OF THE AFTN...WHILE CLOUDS TRY TO CLEAR OUT AT KCMX. GUSTY WINDS...PERHAPS BRIEFLY TO 20 KTS...WILL DIMINISH LATE IN THE AFTN INTO THIS EVENING AS HIGH PRESSURE OVER THE PLAINS DRAWS CLOSER. AS THE RIDGE CROSSES TONIGHT...EXPECT SKIES TO TURN MOSTLY CLEAR WITH WINDS BECOMING LIGHT. VFR CONDITIONS WILL CONTINUE INTO WEDNESDAY WITH SCT-BKN DAYTIME CUMULUS CLOUDS. WINDS SHOULD NOT BE AS GUSTY AS TODAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 351 AM EDT TUE JUL 21 2015 STEADY WNW WINDS UP TO ABOUT 20 KTS WILL DIMINISH TONIGHT WITH THE CLOSER APPROACH OF HI PRES FROM THE NORTHERN PLAINS. SINCE THE HI PRES WILL LINGER NEAR THE GREAT LAKES MUCH OF THIS WEEK...WINDS SHOULD BE UNDER 20 KTS MOST OF THE TIME. SOME STRONGER WINDS UP TO 20 KTS WILL BE POSSIBLE ON FRI/SAT AS A COLD FRONT CROSSES THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...JLA MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 AM EDT TUE JUL 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 351 AM EDT TUE JUL 21 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT OVER THE UPR LKS BTWN CLOSED LO NEAR JAMES BAY AND UPR RDG OVER THE ROCKIES/WRN PLAINS. A DISTURBANCE DROPPING SEWD THRU NW ONTARIO IN CONCERT WITH SOME MSTR IN THE H85-7 LYR SHOWN ON THE 00Z INL/YPL RAOBS IS BRINGING SCT-BKN AC THRU MUCH OF NW ONTARIO...NRN MN AND LK SUP. FARTHER TO THE W IN MANITOBA CLOSER TO THE UPR RDG AXIS AND UNDER STRONGER DEEP LYR QVECTOR DVGC...THE 00Z THE PAS RAOB AT THE NRN END OF LK WINNIPEG SHOWS A MUCH SHARPER MID LVL INVRN. SKIES IN THIS AREA ARE MOCLR. DESPITE SOME RELATIVELY DRY LLVL AIR AND LLVL CAA...STEADY NW WINDS UNDER SHARPER PRES GRADIENT WELL E OF HI PRES CENTER IN THE NRN PLAINS HAS LIMITED THE DIURNAL TEMP DROP. RELATIVELY QUIET QUIET WX WL DOMINATE THE SHORT TERM. MAIN FCST CONCERNS FOCUS ON CLD TRENDS TODAY AND TEMPS TODAY/TNGT. TODAY...SHRTWV DIGGING SEWD THRU NW ONTARIO IS FCST TO BE OVER NE LK SUP BY 12Z AND THEN OVER SE ONTARIO BY 00Z THIS EVNG...WITH DNVA/ SHARPER DEEP LYR QVECTOR OVER THE UPR LKS IN ITS WAKE BRINGING 12HR H5 HGT RISES UP TO 50M IN ITS WAKE. EXPECT SCT-BKN CU TO DEVELOP BY LATE MRNG WITH DAYTIME HEATING UNDER H85 THERMAL TROF/LINGERING MSTR...BUT TENDENCY DURING THE AFTN SHOULD BE FOR THE CU TO SCT OUT WITH SHARPENING SUBSIDENCE INVRN/ARRIVAL OF DRIER AIR SHOWN ON THE PAS RAOB. SOME OF THE HI RES MODELS EVEN GENERATE SOME ISOLD SHOWERS OVER THE ECNTRL CWA TOWARD NOON...BUT WL MAINTAIN DRY FCST FOR NOW GIVEN RELATIVELY STABLE MID LYRS SHOWN ON THE UPSTREAM RAOBS/FCST SDNGS. WINDS MAY ALSO GET A BIT GUSTY AGAIN THIS MRNG UNDER SHARPER PRES GRADIENT/STEEPENING LLVL LAPSE RATES...BUT SFC HI PRES MOVING OVER THE CWA IN THE AFTN SHOULD RESULT IN DIMINISHING WINDS. THE MORE PERSISTENT GUSTY WINDS WL BE OVER THE E...WHERE THE TIGHTER GRADIENT WL LINGER LONGER AND LK BREEZE COMPONENT OFF LK SUP WL ACCENTUATE THIS FLOW. EXPECT THE LOWEST MAX TEMPS IN THIS AREA AS WELL WITH MORE LK SUP MODERATION. LOCATIONS NEAR THE SHORE E OF MQT WL SEE HI TEMPS HOLDING IN THE 60S. AS H85 TEMPS REBOUND TO NEAR 12Z ALONG THE WI BORDER LATER IN THE DAY...THE MERCURY SHOULD RISE WELL INTO THE 70S AND AT LEAST APRCH 80 AT A FEW LOCATIONS OVER THE SCENTRAL WITH DOWNSLOPE FLOW AND LIMITED LK BREEZE OFF LK MI. TNGT...EXPECT LINGERING CU TO DSPT EARLY AND GIVE WAY TO MOCLR SKIES UNDER LARGER SCALE SUBSIDENCE/LOSS OF DAYTIME HEATING. LO TEMPS WL BE COOLEST OVER THE W CLOSER TO SFC HI PRES RDG AXIS APRCHG WRN LK SUP/WEAKER PRES GRADIENT. THE COOL SPOTS MAY SEE THE THERMOMETER READ AS LO AS 45 BY DAYBREAK. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 350 AM EDT TUE JUL 21 2015 IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE. POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION LATE FRI INTO SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT. MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER THU AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE W...WHICH MAINLY INCREASES MID LEVEL MOISTURE ENOUGH TO ALLOW FOR WEAK CONVECTIVE POTENTIAL. MODELS ARE SLOWER WITH THE FRONT THAN THEY WERE YESTERDAY...SO WILL CONTINUE TREND OF LOWERING DEW POINTS ON WED AFTERNOON...BUT FIRE WEATHER CONCERNS WILL BE MINIMAL GIVEN LIGHT WINDS. WILL KEEP SLIGHT CHANCE POPS INTO AREAS ALONG THE WI BORDER THU. THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES BETWEEN MODELS WITH THIS SYSTEM...WITH THE 00Z/21 GFS BEING STRONGER AND FARTHER S THAN THE 12Z/20 ECMWF. WILL USE CONSENSUS GUIDANCE GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH SAT. SUN LOOKS DRY FOR NOW. DEPENDING ON TIMING AND OTHER FACTORS...COULD SEE INGREDIENTS COME TOGETHER FOR SOME STRONG TO SEVERE STORMS MAINLY S OF THE CWA. SUN LOOKS DRY AND MON MAY SEE SOME RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 720 AM EDT TUE JUL 21 2015 ALTHOUGH SOME DIURNAL CU/SC WL DVLP TODAY WITH DAYTIME HEATING IN COOL NW FLOW E OF HI PRES APRCHG FM THE NRN PLAINS...RELATIVELY DRY LLVL AIR INDICATES CIGS WL BE VFR. GUSTY WINDS WL ALSO DEVELOP WITH THE DAYTIME HEATING/MIXING. AS THE HI PRES EDGES CLOSER LATER TDAY/THIS EVNG...SKIES WL TURN MOCLR AND WINDS WL DIMINISH. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 351 AM EDT TUE JUL 21 2015 STEADY WNW WINDS UP TO ABOUT 20 KTS WILL DIMINISH TONIGHT WITH THE CLOSER APPROACH OF HI PRES FROM THE NORTHERN PLAINS. SINCE THE HI PRES WILL LINGER NEAR THE GREAT LAKES MUCH OF THIS WEEK...WINDS SHOULD BE UNDER 20 KTS MOST OF THE TIME. SOME STRONGER WINDS UP TO 20 KTS WILL BE POSSIBLE ON FRI/SAT AS A COLD FRONT CROSSES THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 AM EDT TUE JUL 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 351 AM EDT TUE JUL 21 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT OVER THE UPR LKS BTWN CLOSED LO NEAR JAMES BAY AND UPR RDG OVER THE ROCKIES/WRN PLAINS. A DISTURBANCE DROPPING SEWD THRU NW ONTARIO IN CONCERT WITH SOME MSTR IN THE H85-7 LYR SHOWN ON THE 00Z INL/YPL RAOBS IS BRINGING SCT-BKN AC THRU MUCH OF NW ONTARIO...NRN MN AND LK SUP. FARTHER TO THE W IN MANITOBA CLOSER TO THE UPR RDG AXIS AND UNDER STRONGER DEEP LYR QVECTOR DVGC...THE 00Z THE PAS RAOB AT THE NRN END OF LK WINNIPEG SHOWS A MUCH SHARPER MID LVL INVRN. SKIES IN THIS AREA ARE MOCLR. DESPITE SOME RELATIVELY DRY LLVL AIR AND LLVL CAA...STEADY NW WINDS UNDER SHARPER PRES GRADIENT WELL E OF HI PRES CENTER IN THE NRN PLAINS HAS LIMITED THE DIURNAL TEMP DROP. RELATIVELY QUIET QUIET WX WL DOMINATE THE SHORT TERM. MAIN FCST CONCERNS FOCUS ON CLD TRENDS TODAY AND TEMPS TODAY/TNGT. TODAY...SHRTWV DIGGING SEWD THRU NW ONTARIO IS FCST TO BE OVER NE LK SUP BY 12Z AND THEN OVER SE ONTARIO BY 00Z THIS EVNG...WITH DNVA/ SHARPER DEEP LYR QVECTOR OVER THE UPR LKS IN ITS WAKE BRINGING 12HR H5 HGT RISES UP TO 50M IN ITS WAKE. EXPECT SCT-BKN CU TO DEVELOP BY LATE MRNG WITH DAYTIME HEATING UNDER H85 THERMAL TROF/LINGERING MSTR...BUT TENDENCY DURING THE AFTN SHOULD BE FOR THE CU TO SCT OUT WITH SHARPENING SUBSIDENCE INVRN/ARRIVAL OF DRIER AIR SHOWN ON THE PAS RAOB. SOME OF THE HI RES MODELS EVEN GENERATE SOME ISOLD SHOWERS OVER THE ECNTRL CWA TOWARD NOON...BUT WL MAINTAIN DRY FCST FOR NOW GIVEN RELATIVELY STABLE MID LYRS SHOWN ON THE UPSTREAM RAOBS/FCST SDNGS. WINDS MAY ALSO GET A BIT GUSTY AGAIN THIS MRNG UNDER SHARPER PRES GRADIENT/STEEPENING LLVL LAPSE RATES...BUT SFC HI PRES MOVING OVER THE CWA IN THE AFTN SHOULD RESULT IN DIMINISHING WINDS. THE MORE PERSISTENT GUSTY WINDS WL BE OVER THE E...WHERE THE TIGHTER GRADIENT WL LINGER LONGER AND LK BREEZE COMPONENT OFF LK SUP WL ACCENTUATE THIS FLOW. EXPECT THE LOWEST MAX TEMPS IN THIS AREA AS WELL WITH MORE LK SUP MODERATION. LOCATIONS NEAR THE SHORE E OF MQT WL SEE HI TEMPS HOLDING IN THE 60S. AS H85 TEMPS REBOUND TO NEAR 12Z ALONG THE WI BORDER LATER IN THE DAY...THE MERCURY SHOULD RISE WELL INTO THE 70S AND AT LEAST APRCH 80 AT A FEW LOCATIONS OVER THE SCENTRAL WITH DOWNSLOPE FLOW AND LIMITED LK BREEZE OFF LK MI. TNGT...EXPECT LINGERING CU TO DSPT EARLY AND GIVE WAY TO MOCLR SKIES UNDER LARGER SCALE SUBSIDENCE/LOSS OF DAYTIME HEATING. LO TEMPS WL BE COOLEST OVER THE W CLOSER TO SFC HI PRES RDG AXIS APRCHG WRN LK SUP/WEAKER PRES GRADIENT. THE COOL SPOTS MAY SEE THE THERMOMETER READ AS LO AS 45 BY DAYBREAK. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 350 AM EDT TUE JUL 21 2015 IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE. POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION LATE FRI INTO SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT. MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER THU AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE W...WHICH MAINLY INCREASES MID LEVEL MOISTURE ENOUGH TO ALLOW FOR WEAK CONVECTIVE POTENTIAL. MODELS ARE SLOWER WITH THE FRONT THAN THEY WERE YESTERDAY...SO WILL CONTINUE TREND OF LOWERING DEW POINTS ON WED AFTERNOON...BUT FIRE WEATHER CONCERNS WILL BE MINIMAL GIVEN LIGHT WINDS. WILL KEEP SLIGHT CHANCE POPS INTO AREAS ALONG THE WI BORDER THU. THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES BETWEEN MODELS WITH THIS SYSTEM...WITH THE 00Z/21 GFS BEING STRONGER AND FARTHER S THAN THE 12Z/20 ECMWF. WILL USE CONSENSUS GUIDANCE GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH SAT. SUN LOOKS DRY FOR NOW. DEPENDING ON TIMING AND OTHER FACTORS...COULD SEE INGREDIENTS COME TOGETHER FOR SOME STRONG TO SEVERE STORMS MAINLY S OF THE CWA. SUN LOOKS DRY AND MON MAY SEE SOME RAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 121 AM EDT TUE JUL 21 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE FCST PERIOD ALTHOUGH MORE VFR CU/SC ARE EXPECTED ON TUESDAY. WINDS COULD BE GUSTY AGAIN WITH GUSTS TO AROUND 20 KNOTS AT CMX/SAW IN THE AFTERNOON. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 351 AM EDT TUE JUL 21 2015 STEADY WNW WINDS UP TO ABOUT 20 KTS WILL DIMINISH TONIGHT WITH THE CLOSER APPROACH OF HI PRES FROM THE NORTHERN PLAINS. SINCE THE HI PRES WILL LINGER NEAR THE GREAT LAKES MUCH OF THIS WEEK...WINDS SHOULD BE UNDER 20 KTS MOST OF THE TIME. SOME STRONGER WINDS UP TO 20 KTS WILL BE POSSIBLE ON FRI/SAT AS A COLD FRONT CROSSES THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...JLB MARINE...KC
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1058 PM CDT Wed Jul 22 2015 ...Mesoscale Discussion for Locally Heavy Rainfall Potential... .MESOSCALE DISCUSSION... Issued at 1042 PM CDT WED JUL 22 2015 There appears to be a growing number of signals for localized heavy rainfall/flooding potential from late tonight into Thursday morning. A surface frontal boundary will remain draped across southern Missouri and will move very little through at least early Thursday morning. Meanwhile, a developing low level jet stream will induce increased isentropic upglide overnight from part of eastern Kansas across southwestern Missouri into northern Arkansas. This is also in line with a slug of stronger 850 mb theta-e advection and moisture transport. This should result in scattered to possibly numerous showers and thunderstorms developing as we get into later tonight and early Thursday morning. What is somewhat concerning is the high moisture content of the atmosphere. The 00Z KSGF sounding indicated about 2.00" of precipitable water content. This along with high freezing levels will result in very efficient rainfall rates. Additionally, there appears to be potential for training bands of convection as mean wind fields are fairly aligned with a low level theta-e and overall CAPE gradient. Recent trends in models such as the 00Z NAM and GFS as well as recent HRRR runs seem to back the potential for locally heavy rainfall. We updated the Hazardous Weather Outlook to cover these concerns a bit earlier this evening. One other final note was the addition of fog to the forecast. While we are not looking at widespread dense fog, any areas that experience appreciable breaks in cloud cover should see at least patchy fog. This will especially be true along and north of that front. && .SHORT TERM...(This Evening through Thursday) Issued at 328 PM CDT WED JUL 22 2015 Scattered showers and few storms will continue to occur mainly south of Highway 60 into this evening as weak upper level disturbance tracks east across Kansas and a front remains stalled near the Missouri Arkansas border. Instability has increased across southern Missouri with the heating of the day, but with weak deep layer shear and not very steep low level steep rates the will keep the severe risk very low with this activity. These storms will weaken with the loss of day time heating later this evening. Tonight another upper level shortwave will move out of the central Plains and across the region and could generate additional scattered showers and storms overnight. Deep layer shear will increase with the shortwave, but with the loss of day time heating and being north of the stalled front instability will be limited and not expected much in the way of severe weather overnight. Thursday looks mainly dry as the area will be behind the upper level disturbance. The front will begin to lift to the north on Thursday resulting in temperatures ranging from the middle 80s across central Missouri to around the 90 degree mark across southeastern Kansas Thursday afternoon. .LONG TERM...(Thursday Night through Wednesday) Issued at 328 PM CDT WED JUL 22 2015 The warm front will continue to lift northeast through the region Thursday night into early Friday. Scattered storms will be possible along and north of the front Thursday night, mainly across the eastern Ozarks. An upper level ridge will begin to slide east into the area on Friday and then over the area on Saturday. Highs in the lower to middle 90s are expected west of Highway 65 on Friday afternoon and then across the entire area on Saturday. Heat Index values of 100 to 108 are expected Friday and Saturday afternoons. An upper level disturbance will push the ridge back slightly to the west Saturday night and Sunday. Shower and thunderstorms will be possible across the eastern Ozarks as a result but the better chances should remain north and east of the area as the ridge does not appear to retreat to far to the west. The ridge will build right back over the region next Monday and Tuesday with highs in the lower to middle 90s occurring each afternoon. Medium range models indicate the ridge will flatten allow a front to approach from the north during the middle of next week, bringing chances for showers and thunderstorms to the region. && .AVIATION...(For the 00Z TAFS through 00Z Thursday Evening) Issued at 658 PM CDT WED JUL 22 2015 Scattered showers and an isolated thunderstorm will impact terminals across the Ozarks region this evening with diminishing convection chances overnight. Fog may impact area terminals around 10z prior to sunrise with visibilities falling to MVFR. Visibilities will improve after sunrise, 14z, with high cloud cover remaining through the remainder of the day. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ MESOSCALE...Schaumann SHORT TERM...Wise LONG TERM...Wise AVIATION...Hatch
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
927 PM MDT WED JUL 22 2015 .UPDATE... GUSTY WINDS ACCOMPANIED THUNDERSTORMS AND OUTFLOW BOUNDARIES THIS EVENING WITH MANY AREAS REPORTING GUSTS INTO THE 40S. THE HIGHEST GUSTS OF 54 MPH OCCURRED AT KBIL THIS AFTERNOON...AND THIS EVENING AT KMLS. LATEST RADAR SHOWED A LINE OF STORMS DEVELOPING FROM ROSEBUD INTO SHERIDAN COUNTIES. OTHERWISE THERE WERE A FEW SHOWERS OVER THE AREA. THIS PRECIPITATION WAS DUE TO A SHORTWAVE TRACKING E THROUGH THE REGION AND SEEN ON WATER VAPOR IMAGERY. ANOTHER STRONGER WAVE WAS SEEN MOVING THROUGH ID AND WAS ACCOMPANIED BY NUMEROUS THUNDERSTORMS. THIS WAVE WILL PUSH INTO THE FORECAST AREA OVERNIGHT. WRF AND HRRR WERE HANDLING PRECIPITATION BETTER THAN OTHER MODELS THIS EVENING...BUT WRF WAS DRIER THAN HRRR BY 12Z THU. GIVEN THE STRONG WAVE APPROACHING AND A COLD FRONT CROSSING THE AREA...THE HRRR LOOKED LIKE THE MORE REASONABLE SOLUTION SO HAVE TRENDED POPS TOWARD IT/S QPF TONIGHT. WHILE INSTABILITY WILL INCREASE SOMEWHAT AS THE WAVE MOVES IN...WILL LEAVE THE ISOLATED THUNDER WORDING IN AFTER 06Z GIVEN THE LACK OF DIURNAL HEATING. HAVE SPREAD POPS ACROSS THE ENTIRE AREA OVERNIGHT WITH HIGHEST POPS W OF KBIL. MODELS SHOWED SOME QPF ALONG THE EASTWARD MOVING FRONT AS IT CROSSES THE AREA. REMOVED EVENING GUSTY WIND WORDING WITH THE LOSS OF INSOLATION AND THE CLOSING TEMPERATURE/DEWPOINT SPREADS. UPPER TROUGH SLIDES SLOWLY E OVER THE AREA ON THU. SUPPORT FROM JET COUPLING AND TROUGH...AS WELL AS PRECIPITABLE WATERS OVER AN INCH WILL SUPPORT SHOWERS AND THUNDERSTORMS. SREF SHOWED MORE SHEAR FOR THU BUT NOT VERY HIGH CAPES...AND RISK OF STRONG STORMS WILL DEPEND UPON AMOUNT OF CLOUD COVER THAT REMAINS FROM OVERNIGHT AND MORNING CONVECTION. ARTHUR && .SHORT TERM...VALID FOR THU AND FRI... ANOTHER DAY...ANOTHER ROUND OF THUNDERSTORMS ACROSS OUR REGION. THE WIND FIELDS ARE INCREASING ACROSS OUR WESTERN ZONES THOUGH TODAY WITH THE APPROACH OF AN UPPER TROUGH FROM THE WEST. SO CONDITIONS WILL BE A LITTLE MORE FAVORABLE FOR THUNDERSTORMS TO PRODUCE STRONG WINDS AND SMALL HAIL. WE HAVE THIS MENTIONED IN OUR FORECAST FOR THE WESTERN ZONES WHERE SHEAR IS BY FAR THE BEST ...BUT I DID PULL THIS AREA EASTWARD INTO YELLOWSTONE COUNTY BASED ON SOME HELICITY PROGGS. I BELIEVE THERE IS A SLIGHT CHANCE OF SEEING A STORM STRONG ENOUGH FOR SOME LARGER HAIL...BUT WE SHOULD NOT SEE ANY SORTA BIG SEVERE BREAKOUT GIVEN MODEST SHEAR FOR MOST OF THE AREA AND JUST AVERAGE INSTABILITY. MODELS CONSISTENT IN BRINGING ANOTHER VORTICITY SURGE UP INTO OUR WESTERN ZONES LATER TONIGHT AS WINDS FURTHER BACK AHEAD OF THE UPPER TROUGH. THIS SEEMS TO BRING A GOOD TAP OF MOISTURE FROM THE SOUTH AS WELL. THUS WE RAISED POPS FOR THE ABSAROKA/BEARTOOTH MOUNTAINS AND NORTHWARD LATER TONIGHT AND INTO THURSDAY. THERE APPEARS TO BE A GOOD DEAL OF DYNAMIC FORCING ACROSS THE WESTERN AND CENTRAL ZONES THURSDAY. WE HAVE JET MAXIMUM MOVING THROUGH THE ROCKIES ASSOCIATED WITH THE UPPER TROUGH AS WELL. SO POCKETS OF HEAVY RAIN ARE POSSIBLE WITH PRECIP WATER VALUES ABOUT TWO STANDARD ANOMALIES ABOVE AVERAGE IN OUR CENTRAL AND WEST. I AM HESITANT TO MENTION ANYTHING MORE THAN SOME SMALLER HAIL AND WIND WITH THUNDERSTORMS TOMORROW AS OUR INSTABILITY WILL BE AVERAGE AGAIN DUE TO CLOUD COVER...AND TIMING OF THE BEST FORCING MAY NOT OCCUR DURING THE BEST TIME OF DAY. SO COOLER AND RAINY CONDITIONS ARE EXPECTED BUT NOT ANY WIDESPREAD LARGE HAIL OR DAMAGING WIND ISSUES. .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... FOR THE WEEKEND THE MODELS REMAIN FAIRLY CONFIDENT WITH THE GENERALLY RIDGY PATTERN FOR THE WEEKEND. THIS CONTINUES TO KEEP THE AREA GENERALLY DRY AND WARM. WITH THE GENERALLY WESTERLY TO SOUTHWESTERLY SURFACE WINDS...EXPECTING TEMPERATURES TO REMAIN SLIGHTLY ABOVE NORMAL AND HIGHS IN THE LOWER 90S. GOING INTO THE FIRST PART OF THE WEEK...MODELS ARE LESS CERTAIN...BUT MODELS HAVE BEEN TRENDING TOWARDS A MORE NORTHERLY TRACK WITH THE TROUGH. THIS SOLUTION TAKES MOST OF THE ENERGY NORTH OF THE AREA ALONG WITH MOST OF THE PRECIP. WINDS WILL INCREASE BEHIND THE FRONT OUT OF THE NORTHWEST AT 15 TO 20 MPH. GIVEN THAT CONDITIONS ARE LOOKING DRIER...THIS COULD INCREASE FIRE WEATHER CONCERNS. THE ONE CAVEAT TO THIS IS THAT THE 12Z ECMWF IS LESS NORTHERLY WITH THE TRACK OF THE TROUGH. THIS TAKES THE ENERGY MORE ACROSS THE AREA AND IS A LITTLE MORE AGGRESSIVE WITH GENERATING PRECIP ACROSS THE AREA. REIMER && .AVIATION... LOCAL SUB-VFR CONDITIONS AND MOUNTAIN OBSCURATIONS COULD ACCOMPANY SHOWERS AND THUNDERSTORMS ACROSS THE AREA TONIGHT AND THURSDAY. WE EXPECT THIS ACTIVITY TO BE MOST NUMEROUS OVER WESTERN SECTIONS OF SOUTH CENTRAL MT /AROUND KLVM/ BETWEEN 06 AND 18 UTC...BUT THERE/S AT LEAST A CHANCE OF A SHOWER OR STORM IN MOST LOCATIONS THROUGH THURSDAY EVENING. VFR CONDITIONS WILL OTHERWISE PREVAIL. SCHULTZ && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 063/082 059/087 060/090 061/093 061/082 055/083 057/087 44/T 42/T 11/B 12/T 23/T 31/B 11/U LVM 056/075 052/084 052/086 053/088 052/078 047/082 051/085 77/T 62/T 11/B 22/T 22/T 21/U 11/U HDN 061/085 058/090 057/092 060/096 059/086 054/085 056/089 33/T 32/T 11/B 12/T 22/T 21/B 11/U MLS 065/089 061/090 061/094 064/098 063/086 056/085 058/089 33/T 32/W 11/B 12/T 22/T 21/B 11/U 4BQ 063/091 060/089 061/092 063/097 063/087 056/084 057/088 33/T 22/T 12/T 11/U 12/T 21/B 11/U BHK 062/090 058/087 059/091 060/095 061/085 055/082 054/086 33/T 22/W 12/T 12/T 22/T 21/B 11/U SHR 058/085 055/086 055/088 056/093 056/084 051/081 052/085 25/T 32/T 21/B 11/B 22/T 21/B 11/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1226 PM CDT TUE JUL 21 2015 .DISCUSSION... /ISSUED 308 AM CDT TUE JUL 21 2015/ CURRENTLY A SNAKING LINE OF CONVECTION EXTENDING FROM THE TEXAS PANHANDLE TO EASTERN KENTUCKY CONTINUES TO FIZZLE MIDWAY ACROSS THE MIDSOUTH THIS MORNING...LEAVING ONLY A FEW SHOWERS IN EASTERN ARKANSAS AND A BLANKET OF MID AND HIGH LEVEL MOISTURE. CLOUD COVER WAS KEEPING TEMPERATURES A DEGREE OR TWO WARMER THAN THIS TIME LAST NIGHT FROM I-40 SOUTH...WHILE EVENING RAIN EARLIER AND A WEAK OUTFLOW BOUNDARY IS PROVIDING COOLER TEMPERATURES FARTHER NORTH. THE HRRR SHOWS NEW CONVECTION FORMING ACROSS THE NORTH BY 4 AM...BUT RADAR TRENDS AND MESOANALYSIS IS SUGGESTING MORE STABILITY IN THIS REGION. FOR TODAY THROUGH THURSDAY...THE MIDSOUTH WILL TAKE A SHORT BREAK FROM THE HEAT THIS PERIOD...WITH THE ONLY EXCEPTION BEING THE SOUTHERN TWO TIER OF COUNTIES TODAY....WHERE A HEAT ADVISORY IS IN EFFECT STARTING LATER THIS MORNING. THE UPPER RIDGE IS EXPECTED TO SAG FAR ENOUGH SOUTH TO ALLOW THE PREVAILING WESTERLIES...AND ASSOCIATED DISTURBANCES TO PASS OVER A STALLED SURFACE FRONT. EACH FEATURE ALLOWING THE CHANCE FOR SHOWERS AND STORMS TO FORM...WITH A NEAR EQUAL THREAT BOTH DAY AND NIGHT. TOMORROW APPEARS THE COOLEST BY THE MODELS WITH PLENTY OF HIGHS IN THE 80S AND WIDESPREAD HEAT INDICES FINALLY DIPPING BELOW 100F. THE BIGGER QUESTION IS WILL THERE BE A THREAT FOR SEVERE WEATHER OR FLASH FLOODING. MU CAPE VALUES BY THE MID AFTERNOON HOURS WILL RANGE FROM 2000 TO 3500 J/KG AND THE POSSIBILITY OF STORMS TRAINING SEEMS VERY PLAUSIBLE. FEEL PULSE TYPE STORMS WILL DEVELOP TODAY AND TOMORROW WITH THE GREATER POTENTIAL FOR SOMETHING MORE ORGANIZED HAPPENING TOMORROW NIGHT AND THURSDAY WHEN A 25KT LLJ AT 850MB INTERSECTS THE REGION. WILL KEEP THE SAME MENTION IN THIS MORNINGS HWO WITH THE ADDITION OF A LOCALIZED FLASH FLOODING THREAT. FRIDAY THROUGH MONDAY...THE GFS AND EURO ARE IN GOOD AGREEMENT THAT THE RIDGE WILL BUILD BACK NORTH...BUT THERE ARE SLIGHT DIFFERENCES ON JUST HOW FAR EAST. THE FARTHER WEST EURO SOLUTION WOULD KEEP THE MIDSOUTH IN THE CROSSHAIRS FOR MORE MCS CONVECTION/NORTHWESTERLY FLOW...WHILE THE GFS IS A BIT HOTTER AND DRIER AS THE RIDGE MOVES INTO THE TENNESSEE RIVER VALLEY. THIS WOULD LEAD TO PERHAPS ISOLATED DIURNAL CONVECTION AT BEST. FOR NOW HAVE LEANED MORE TOWARDS THE GFS...AS IT IS HANDLING THE CURRENT SITUATION BETTER. HIGHS WOULD CLIMB BACK INTO THE MID AND UPPER 90S...AND THE NEED FOR ADDITIONAL HEAT PRODUCTS LIKELY. JAB && .AVIATION... 18Z TAF SET VFR CONDITIONS GENERALLY EXPECTED OVER THE NEXT 24 HOURS. DIURNAL SHRAS/TSRAS EXPECTED TO DEVELOP BETWEEN 19-21Z ACROSS THE AREA. THE STORMS SHOULD DISSIPATE BY 3Z. IF A TSRA WOULD HIT A TAF LOCATION...CONDITIONS COULD DETERIORATE TO MVFR OR LOWER. NOT ENOUGH CONFIDENT TO PUT ANY TEMPO GROUP IN AT THIS POINT. IN ADDITION...A MCS MAY DEVELOP OVERNIGHT AND APPROACH KJBR AROUND 9Z AND POSSIBLY KMEM AROUND 12Z. FOR NOW JUST MENTIONED VCTS OR VCSH WORDING. WINDS WILL GENERALLY BE LIGHT AND VARIABLE. KRM && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR PHILLIPS. MO...NONE. MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CALHOUN-CHICKASAW- COAHOMA-ITAWAMBA-LAFAYETTE-LEE MS-MONROE-PANOLA-PONTOTOC- QUITMAN-TALLAHATCHIE-UNION-YALOBUSHA. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
605 AM CDT TUE JUL 21 2015 .UPDATE... UPDATED TO INCLUDE THE 12Z AVIATION DISCUSSION BELOW. JCL && .DISCUSSION... /ISSUED 308 AM CDT TUE JUL 21 2015/ CURRENTLY A SNAKING LINE OF CONVECTION EXTENDING FROM THE TEXAS PANHANDLE TO EASTERN KENTUCKY CONTINUES TO FIZZLE MIDWAY ACROSS THE MIDSOUTH THIS MORNING...LEAVING ONLY A FEW SHOWERS IN EASTERN ARKANSAS AND A BLANKET OF MID AND HIGH LEVEL MOISTURE. CLOUD COVER WAS KEEPING TEMPERATURES A DEGREE OR TWO WARMER THAN THIS TIME LAST NIGHT FROM I-40 SOUTH...WHILE EVENING RAIN EARLIER AND A WEAK OUTFLOW BOUNDARY IS PROVIDING COOLER TEMPERATURES FARTHER NORTH. THE HRRR SHOWS NEW CONVECTION FORMING ACROSS THE NORTH BY 4 AM...BUT RADAR TRENDS AND MESOANALYSIS IS SUGGESTING MORE STABILITY IN THIS REGION. FOR TODAY THROUGH THURSDAY...THE MIDSOUTH WILL TAKE A SHORT BREAK FROM THE HEAT THIS PERIOD...WITH THE ONLY EXCEPTION BEING THE SOUTHERN TWO TIER OF COUNTIES TODAY....WHERE A HEAT ADVISORY IS IN EFFECT STARTING LATER THIS MORNING. THE UPPER RIDGE IS EXPECTED TO SAG FAR ENOUGH SOUTH TO ALLOW THE PREVAILING WESTERLIES...AND ASSOCIATED DISTURBANCES TO PASS OVER A STALLED SURFACE FRONT. EACH FEATURE ALLOWING THE CHANCE FOR SHOWERS AND STORMS TO FORM...WITH A NEAR EQUAL THREAT BOTH DAY AND NIGHT. TOMORROW APPEARS THE COOLEST BY THE MODELS WITH PLENTY OF HIGHS IN THE 80S AND WIDESPREAD HEAT INDICES FINALLY DIPPING BELOW 100F. THE BIGGER QUESTION IS WILL THERE BE A THREAT FOR SEVERE WEATHER OR FLASH FLOODING. MU CAPE VALUES BY THE MID AFTERNOON HOURS WILL RANGE FROM 2000 TO 3500 J/KG AND THE POSSIBILITY OF STORMS TRAINING SEEMS VERY PLAUSIBLE. FEEL PULSE TYPE STORMS WILL DEVELOP TODAY AND TOMORROW WITH THE GREATER POTENTIAL FOR SOMETHING MORE ORGANIZED HAPPENING TOMORROW NIGHT AND THURSDAY WHEN A 25KT LLJ AT 850MB INTERSECTS THE REGION. WILL KEEP THE SAME MENTION IN THIS MORNINGS HWO WITH THE ADDITION OF A LOCALIZED FLASH FLOODING THREAT. FRIDAY THROUGH MONDAY...THE GFS AND EURO ARE IN GOOD AGREEMENT THAT THE RIDGE WILL BUILD BACK NORTH...BUT THERE ARE SLIGHT DIFFERENCES ON JUST HOW FAR EAST. THE FARTHER WEST EURO SOLUTION WOULD KEEP THE MIDSOUTH IN THE CROSSHAIRS FOR MORE MCS CONVECTION/NORTHWESTERLY FLOW...WHILE THE GFS IS A BIT HOTTER AND DRIER AS THE RIDGE MOVES INTO THE TENNESSEE RIVER VALLEY. THIS WOULD LEAD TO PERHAPS ISOLATED DIURNAL CONVECTION AT BEST. FOR NOW HAVE LEANED MORE TOWARDS THE GFS...AS IT IS HANDLING THE CURRENT SITUATION BETTER. HIGHS WOULD CLIMB BACK INTO THE MID AND UPPER 90S...AND THE NEED FOR ADDITIONAL HEAT PRODUCTS LIKELY. JAB && .AVIATION... 12Z TAF CYCLE (21/12Z-22/12Z) VFR CONDITIONS WILL PREVAIL DURING THE PERIOD. HOWEVER...CONDITIONS OCCASIONALLY LOWERING IN SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING MAINLY LATE THIS MORNING AND AFTERNOON...CONTINUING INTO TONIGHT. UNTIL CAN PINPOINT BETTER...WENT VCTS / VCSH AT THE TAF SITES. WINDS TODAY W-NW 5-8 KTS TURNING TO THE NE AT KJBR BY AFTERNOON. WINDS TONIGHT LIGHT. JCL && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING FOR PHILLIPS. MO...NONE. MS...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING FOR CALHOUN-CHICKASAW-COAHOMA-ITAWAMBA-LAFAYETTE-LEE MS- MONROE-PANOLA-PONTOTOC-QUITMAN-TALLAHATCHIE-UNION-YALOBUSHA. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
308 AM CDT TUE JUL 21 2015 .DISCUSSION... CURRENTLY A SNAKING LINE OF CONVECTION EXTENDING FROM THE TEXAS PANHANDLE TO EASTERN KENTUCKY CONTINUES TO FIZZLE MIDWAY ACROSS THE MIDSOUTH THIS MORNING...LEAVING ONLY A FEW SHOWERS IN EASTERN ARKANSAS AND A BLANKET OF MID AND HIGH LEVEL MOISTURE. CLOUD COVER WAS KEEPING TEMPERATURES A DEGREE OR TWO WARMER THAN THIS TIME LAST NIGHT FROM I-40 SOUTH...WHILE EVENING RAIN EARLIER AND A WEAK OUTFLOW BOUNDARY IS PROVIDING COOLER TEMPERATURES FARTHER NORTH. THE HRRR SHOWS NEW CONVECTION FORMING ACROSS THE NORTH BY 4 AM...BUT RADAR TRENDS AND MESOANALYSIS IS SUGGESTING MORE STABILITY IN THIS REGION. FOR TODAY THROUGH THURSDAY...THE MIDSOUTH WILL TAKE A SHORT BREAK FROM THE HEAT THIS PERIOD...WITH THE ONLY EXCEPTION BEING THE SOUTHERN TWO TIER OF COUNTIES TODAY....WHERE A HEAT ADVISORY IS IN EFFECT STARTING LATER THIS MORNING. THE UPPER RIDGE IS EXPECTED TO SAG FAR ENOUGH SOUTH TO ALLOW THE PREVAILING WESTERLIES...AND ASSOCIATED DISTURBANCES TO PASS OVER A STALLED SURFACE FRONT. EACH FEATURE ALLOWING THE CHANCE FOR SHOWERS AND STORMS TO FORM...WITH A NEAR EQUAL THREAT BOTH DAY AND NIGHT. TOMORROW APPEARS THE COOLEST BY THE MODELS WITH PLENTY OF HIGHS IN THE 80S AND WIDESPREAD HEAT INDICES FINALLY DIPPING BELOW 100F. THE BIGGER QUESTION IS WILL THERE BE A THREAT FOR SEVERE WEATHER OR FLASH FLOODING. MU CAPE VALUES BY THE MID AFTERNOON HOURS WILL RANGE FROM 2000 TO 3500 J/KG AND THE POSSIBILITY OF STORMS TRAINING SEEMS VERY PLAUSIBLE. FEEL PULSE TYPE STORMS WILL DEVELOP TODAY AND TOMORROW WITH THE GREATER POTENTIAL FOR SOMETHING MORE ORGANIZED HAPPENING TOMORROW NIGHT AND THURSDAY WHEN A 25KT LLJ AT 850MB INTERSECTS THE REGION. WILL KEEP THE SAME MENTION IN THIS MORNINGS HWO WITH THE ADDITION OF A LOCALIZED FLASH FLOODING THREAT. FRIDAY THROUGH MONDAY...THE GFS AND EURO ARE IN GOOD AGREEMENT THAT THE RIDGE WILL BUILD BACK NORTH...BUT THERE ARE SLIGHT DIFFERENCES ON JUST HOW FAR EAST. THE FARTHER WEST EURO SOLUTION WOULD KEEP THE MIDSOUTH IN THE CROSSHAIRS FOR MORE MCS CONVECTION/NORTHWESTERLY FLOW...WHILE THE GFS IS A BIT HOTTER AND DRIER AS THE RIDGE MOVES INTO THE TENNESSEE RIVER VALLEY. THIS WOULD LEAD TO PERHAPS ISOLATED DIURNAL CONVECTION AT BEST. FOR NOW HAVE LEANED MORE TOWARDS THE GFS...AS IT IS HANDLING THE CURRENT SITUATION BETTER. HIGHS WOULD CLIMB BACK INTO THE MID AND UPPER 90S...AND THE NEED FOR ADDITIONAL HEAT PRODUCTS LIKELY. JAB && .AVIATION... FOR 06Z TAFS VFR CONDITIONS WITH NORTHERLY WINDS. SOME SCATTERED SHOWERS IN THE NORTH...HOWEVER...NOT EXPECTING TO REACH ANY OF THE TAF SITES EARLY THIS MORNING. HOWEVER...AFTERNOON SHOWERS/THUNDERSTORMS ARE POSSIBLE ON TUESDAY SO HAVE VICINITY THUNDERSTORMS AT ALL SITES. TLSJR && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING FOR PHILLIPS. MO...NONE. MS...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING FOR CALHOUN-CHICKASAW-COAHOMA-ITAWAMBA-LAFAYETTE-LEE MS- MONROE-PANOLA-PONTOTOC-QUITMAN-TALLAHATCHIE-UNION-YALOBUSHA. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
432 PM CDT TUE JUL 21 2015 .DISCUSSION... PRIMARY FOCUS CONTINUES TO BE POTENTIAL FOR ADDITIONAL FLOODING TONIGHT AS MANY LOCATIONS ARE SATURATED FROM LAST NIGHT. 12Z SOUNDING SHOWS SIGNIFICANT CONVECTIVE OVERTURNING WITH VERY SHALLOW LOW LEVEL MOISTURE AND A MARKED DECREASE IN MOISTURE JUST ABOVE THAT THROUGHOUT THE LOW LEVELS. MID-HIGH LEVEL CLOUDS KEPT THE AREA FROM DESTABILIZATION AS SIGNIFICANTLY AS YESTERDAY AND ABSENCE OF ANY WELL DEFINED SURFACE BOUNDARIES HAS YIELDED A FAIRLY UNIFORM CUMULUS FIELD PER VISIBLE SATELLITE THIS AFTERNOON. SOME TERRAIN INDUCED CONVECTION IN NEW MEXICO HAS FORMED BUT OVERALL EXPANSIVENESS IS FAR LESS THAN YESTERDAY AT THIS TIME. WATER VAPOR LOOP AND RAP PV ANALYSIS SHOW ONE WAVE TRAVERSING THE PANHANDLES NOW WITH SUBSIDENCE FOLLOWING THIS FEATURE ALREADY OVERSPREADING THE WESTERN PORTION OF THE AREA. HAVE SIGNIFICANTLY LOWERED PRECIPITATION PROBABILITIES TONIGHT GIVEN TRENDS. MID LEVEL HEIGHTS RISE AS RIDGE ONCE AGAIN AMPLIFIES. THIS SHOULD LIMIT COVERAGE OF CONVECTION FOR MUCH OF THE WEEK. ISOLATED THUNDERSTORMS MAY OCCUR MAINLY OVER THE FAR NORTHWEST PORTION OF THE AREA. THE RIDGE WEAKENS AGAIN SUFFICIENTLY FOR AN INCREASE IN PRECIPITATION PROBABILITIES ESPECIALLY ACROSS THE NORTHERN PORTION OF THE AREA SATURDAY AND SUNDAY. BRB && .PRELIMINARY POINT TEMPS/POPS... AMARILLO TX 66 89 69 93 71 / 30 10 20 10 10 BEAVER OK 66 90 69 98 72 / 40 10 10 10 10 BOISE CITY OK 63 91 66 94 67 / 30 20 20 20 20 BORGER TX 69 93 72 96 73 / 30 10 10 10 10 BOYS RANCH TX 67 94 70 96 71 / 30 20 20 10 10 CANYON TX 66 91 68 94 70 / 30 10 20 10 10 CLARENDON TX 68 92 71 95 72 / 30 10 10 5 5 DALHART TX 65 94 67 96 68 / 30 20 20 20 10 GUYMON OK 66 93 68 97 70 / 40 10 10 10 20 HEREFORD TX 66 92 68 94 69 / 30 20 20 10 10 LIPSCOMB TX 68 91 71 98 73 / 40 10 10 10 10 PAMPA TX 66 89 69 94 70 / 30 10 10 10 10 SHAMROCK TX 69 93 71 97 72 / 30 5 5 5 5 WELLINGTON TX 70 95 72 98 73 / 30 5 5 5 5 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 01/17
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
315 PM CDT TUE JUL 21 2015 .SHORT TERM... MORE RAIN IS EXPECTED AGAIN LATER THIS AFTERNOON AND EVENING FOR WEST TEXAS...THIS TIME WITH A BIT MORE COVERAGE THAN LAST NIGHT IF THE FORECAST PANS OUT AS EXPECTED. MODELS PRE-12Z WERE VERY SKEPTICAL AND DIFFERED GREATLY ON WHERE AND WHEN CONVECTION WOULD OCCUR LATER TODAY. WHILE SOME QUESTIONS STILL REMAIN...MOST MODELS MINUS THE HRRR HAVE COME INTO AGREEMENT THAT CONVECTION SHOULD SPREAD FARTHER SOUTH AND EAST THAN YESTERDAY AFTERNOON. THE 12Z NAM SEEMED TO HAVE AT FIRST GLANCE THE BEST HANDLE ON THE FORECAST AS IT PICKED UP ON AN AREA OF LIFT OVER SOUTH-CENTRAL NM WHICH STARTED TO SHOW UP ON WV JUST AFTER 13Z. THE AREA OF LIFT HAS SINCE ENHANCED FURTHER AND HAS AIDED IN THE DEVELOPMENT OF EASTWARD PROPAGATING THUNDERSTORMS JUST EAST OF RUIDOSO NM. THESE STORMS SHOULD GRADUALLY MAKE THEIR WAY TOWARDS THE TX/NM STATE LINE BY THE LATE AFTERNOON/EARLY EVENING. ANOTHER AREA OF INTEREST FOR SHOWER AND THUNDERSTORM DEVELOPMENT IS A WESTWARD PROPAGATING SURFACE BOUNDARY ACROSS THE WESTERN THIRD OF THE FA. HIGHER RES MODELS...EVEN THE HRRR TO AN EXTENT...HAVE HINTED AT CONVECTIVE DEVELOPMENT ALONG THIS BOUNDARY WITHIN THE NEXT FEW HOURS AS MLCAPE INCREASES TO AROUND 1500 J/KG. THE AMOUNT OF CAPE THAT WILL BECOME AVAILABLE WILL DEPEND ON HOW MUCH ADDITIONS SURFACE HEATING CAN BE ACHIEVED AS TEMPS ARE COOLER THAN EXPECTED THIS AFTERNOON DUE TO CLOUD COVER THAT LINGERED INTO MID DAY. THE MAIN THREAT...AS IS USUALLY OUT HERE IN THESE PARTS...FROM CONVECTION WOULD BE STRONG TO POSSIBLY MARGINALLY SEVERE WINDS ASSOCIATED WITH DOWNBURSTS. HEAVY RAIN WILL ALSO BE A VALID THREAT AS WAS SEEN YESTERDAY EVENING. RAIN CHANCES WILL DIMINISH OVERNIGHT AS THE ATMOSPHERE COOLS AND STABILIZES. THE RIDGE WILL SLOWLY PUSH BACK INTO THE REGION MAKING WAY FOR HEIGHT RISES TOMORROW WHICH WILL GREATLY DECREASE STORM CHANCES ACROSS THE FA TOMORROW AFTERNOON. THE BEST CHANCES WILL BE IN OUR WESTERN ZONES WHICH WILL BE LOCATED NEAR THE WESTERN EDGE OF THE RIDGE. HIGH TEMPS TOMORROW WILL BE DEPENDENT UPON CONVECTIVE COVERAGE TONIGHT WHICH COULD COOL TEMPS BY SEVERAL DEGREES. FOR NOW MID 90S ON THE CAPROCK/UPPER 90S ACROSS THE ROLLING PLAINS WILL BE MAINTAINED. ALDRICH .LONG TERM... CHANCES OF PRECIPITATION WILL BE FLEETING BY THURSDAY AFTERNOON ON THE WESTERN EDGE OF AN UPPER LEVEL RIDGE MOVING OVERHEAD. HEIGHT RISES WILL LIKELY SQUASH ANY CONVECTION LOCALLY. AFTERNOON/EVENING STORMS ARE STILL LIKELY ACROSS NEW MEXICO WITHIN SURFACE TROUGHING WELL WEST OF THE REGION. THERE IS SOME CHANCE BUT VERY LITTLE OF ANY STORMS BEING ABLE TO CROSS STATE LINES THROUGH EARLY NEXT WEEK. LATEST MOS GUIDANCE HAS CONTINUED ITS WARM BIAS ON MAX TEMPERATURES AND WILL CONTINUE TO FORECAST BELOW MOS...CLOSER TO BIAS CORRECTED GUIDANCE. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 90 67 94 / 40 20 20 20 TULIA 66 92 69 95 / 40 10 20 10 PLAINVIEW 68 91 70 94 / 40 10 20 0 LEVELLAND 68 93 71 95 / 30 20 20 10 LUBBOCK 72 94 72 97 / 30 20 10 0 DENVER CITY 69 94 70 95 / 30 20 20 20 BROWNFIELD 69 94 71 96 / 30 20 20 0 CHILDRESS 73 98 75 101 / 40 10 10 0 SPUR 70 94 73 96 / 30 10 10 0 ASPERMONT 73 98 76 101 / 20 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 51/01
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1228 PM CDT TUE JUL 21 2015 .AVIATION... THE UPPER LEVEL RIDGE LINGERING OVER THE REGION FOR THE PAST SEVERAL DAYS WILL WEAKEN SLIGHTLY AND SHIFT A LITTLE TO THE SOUTH THROUGH WEDNESDAY. AT THE SURFACE...A WEAK FRONT HAS WORKED SOUTHWARD THE PAST 24 HOURS AND WAS NOW STATIONARY ALONG A MIDLAND TO WICHITA FALLS TO PINE BLUFF LINE. AREAS ALONG AND NORTH OF THIS FRONT WILL REMAIN CONVECTIVELY ACTIVE WITH STRONG TO SEVERE STORMS DURING THIS TAF FORECAST. NORTH/CENTRAL TEXAS TERMINALS WILL REMAIN VFR WITH SOME HIGH CLOUDS AND LIGHT SOUTHERLY WINDS DURING THIS FORECAST CYCLE. GROUND OPERATIONS WILL EXPERIENCE AFTERNOON HEAT INDICES IN THE 100 TO 103 DEGREE RANGE TODAY AND AGAIN ON WEDNESDAY. LOOKING AHEAD...NO SIGNIFICANT CHANGES ARE FORESEEN THE REST OF THE WEEK. 75 && .PREV DISCUSSION... /ISSUED 328 AM CDT TUE JUL 21 2015/ THE UPPER LEVEL RIDGE THAT HAS DOMINATED THE WEATHER ACROSS THE REGION FOR THE LAST WEEK IS SHOWING SOME SIGNS OF A SLIGHT WEAKENING AS A SHORT WAVE MOVES ACROSS ITS NORTHERN PERIPHERY. THIS HAS ALLOWED A COLD FRONT TO MOVE DOWN INTO NORTHERN OKLAHOMA AND WEST TEXAS. THIS FRONT WILL STALL OUT ACROSS CENTRAL OKLAHOMA INTO WEST TEXAS THIS AFTERNOON OR EVENING BEFORE LIFTING BACK TO THE NORTH BY WEDNESDAY MORNING. SOME OF THE HIGH CLOUDS ASSOCIATED WITH CONVECTION ACROSS OKLAHOMA AND THE TEXAS PANHANDLE WILL ATTEMPT TO MOVE INTO NORTH TODAY BUT THESE CLOUDS SHOULD THIN. THE MAIN AREA OF DENSER CLOUDS WILL MOVE EAST ACROSS OKLAHOMA. TEMPERATURES TODAY SHOULD BE A DEGREE OR TWO COOLER VERSUS YESTERDAY THANKS TO THE WEAKENING RIDGE. EXPECT HIGHS IN THE MID 90S TO NEAR 100 DEGREES ACROSS THE REGION. THE HRRR INDICATES THAT SOME ISOLATED SHOWERS/THUNDERSTORMS WILL TRY TO FORM THIS AFTERNOON FROM GRANBURY THROUGH THE METROPLEX NORTHEAST TOWARD PARIS. THE SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL PROBABLY BE TOO STRONG FOR THIS TO OCCUR SO HAVE JUST PLACED 10 PERCENT POPS WITH NO WEATHER MENTIONED FOR THIS AFTERNOON AND EVENING ALONG AND NORTH OF A COMANCHE TO EMORY LINE. THE UPPER RIDGE WILL SHIFT WEST INTO WEST TEXAS AND RE-STRENGTHEN LATE WEEK. THIS WILL ALLOW TEMPERATURES TO INCREASE BY A FEW DEGREES LATE WEEK THROUGH THE WEEKEND. WE MAY BE REACH HEAT ADVISORY CRITERIA ACROSS THE EASTERN THIRD TO HALF SUNDAY/MONDAY. THE ECMWF AND GFS INDICATE THAT THE RIDGE WILL SHIFT A LITTLE TO THE NORTH EARLY TO MID NEXT WEEK...WHICH MAY ALLOW FOR SOME LOW RAIN CHANCES ACROSS THE SOUTHEASTERN AND SOUTHERN ZONES BY THE MIDDLE OF NEXT WEEK. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 98 79 98 79 99 / 10 5 5 0 0 WACO, TX 97 75 97 75 98 / 0 0 0 0 0 PARIS, TX 97 76 96 75 96 / 10 10 10 0 0 DENTON, TX 98 77 98 78 99 / 10 10 10 0 0 MCKINNEY, TX 96 77 97 78 98 / 10 5 10 0 0 DALLAS, TX 99 80 99 81 100 / 10 5 5 0 0 TERRELL, TX 97 76 96 76 99 / 10 5 5 0 0 CORSICANA, TX 98 76 97 76 99 / 0 0 5 0 0 TEMPLE, TX 97 74 96 75 97 / 0 0 0 0 0 MINERAL WELLS, TX 96 75 96 75 98 / 10 5 5 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 75
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1213 PM CDT Tue Jul 21 2015 .AVIATION... /18Z TAFS/ Look for VFR conditions to continue for the next 24 hours. All available short-term model data indicate stratus return tonight not likely. Thus, persistence forecast looks good. && .PREV DISCUSSION... /ISSUED 642 AM CDT Tue Jul 21 2015/ AVIATION... /12Z TAFS/ The low clouds over the Hill Country dissipated this morning before reaching KJCT. This will spell VFR conditions across the forecast area through the TAF period. Expect south winds around 10 kts this afternoon with a high based cu field (8,000-10,000 ft) developing by midday. A few of the hi-res models continue to indicate isolated convection this afternoon, mainly west of a KSWW-KSJT line. However, any cells that develop should remain to the north and west of the forecast terminals. Johnson PREV DISCUSSION... /ISSUED 411 AM CDT Tue Jul 21 2015/ SHORT TERM... (Today and tonight) One shortwave trough is lifting northeast across NM this morning, providing large scale forcing for ascent across the Panhandle and portions of west TX. At the surface, a cold front was located from the south plains, extending northeast into central OK. Outflow from evening convection is forcing the effective front to the southeast, from near Vernon, to Jayton, to Midland as of 3 AM. This boundary will likely move into the Big Country and western Concho Valley this morning but is expected to erode by midday, given the shallow nature of the "cool" airmass. This should have only a slight effect on temperatures this afternoon, mainly over the northwest quadrant of the CWA. Expect highs ranging from the upper 90s to near 102 degrees this afternoon, with similar heat indices. A second shortwave trough is progged to lift northeast across NM this afternoon and evening, providing another round of convection to our north and west. The HRRR and ARW both indicate isolated convection along the western periphery of the CWA this afternoon, but the NAM, GFS, and ECMWF are largely dry. While a rogue shower/storm can`t be ruled out this afternoon, coverage should be significantly limited given the warm temps aloft, weak cap, and depth of the boundary layer (increasing dry air entrainment into potential updrafts). Thus, no PoPs will be carried in the forecast. Expect partly cloudy conditions overnight with overnight lows in the mid 70s. Johnson LONG TERM... (Wednesday through next Monday) By Wednesday, the frontal zone currently currently extending from the TX panhandle into Oklahoma will be lifting northward into the central plains. On Thursday, the upper level ridge will re-center and strengthen directly over west Texas. With the ridge in place across the southern plains through early next week, persistent southwesterly flow across the Rocky Mountains will result in lee troughing, and continue warm, southerly flow for our area through the extended period. Due to this ridging and persistent southerly flow, 850mb temperatures will warm a degree or two Celsius by Monday. This will result in persistent hot and dry weather for our area with highs in the upper 90s to around 100 degrees, lows in the mid to upper 70s, and no chance for rainfall. && .PRELIMINARY POINT TEMPS/POPS... Abilene 76 98 76 98 77 / 5 0 0 0 0 San Angelo 75 100 76 99 76 / 0 0 0 0 0 Junction 74 98 74 97 75 / 0 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1150 AM CDT TUE JUL 21 2015 .AVIATION... WHILE VFR CONDITIONS ARE EXPECTED TO PREVAIL OVER THE NEXT 24 HOURS SOME QUESTIONS EXIST OVER THE CHANCE FOR CONVECTION AT ALL THREE TERMINALS LATER THIS AFTERNOON AND EVENING. CONFIDENCE IS INCREASING OVER THE CHANCE OF TSRA MAINLY AT PVW AND LBB THIS AFTERNOON...HOWEVER THERE ARE ENOUGH FACTORS THAT MAY INHIBIT CONVECTION FROM REACHING THE TERMINALS THAT MENTION OF TSRA IN THE TAF WILL BE LEFT OUT. IF CONFIDENCE CONTINUES TO INCREASE AS MORE DATA BECOMES AVAILABLE THEN THE TAFS WILL BE AMENDED ACCORDINGLY. THE BIGGEST THREAT FROM ANY CONVECTION THAT FORMS WILL BE STRONG WINDS OVER 40 MPH. && .PREV DISCUSSION... /ISSUED 400 AM CDT TUE JUL 21 2015/ SHORT TERM... AS WAS EXPECTED...A FAIRLY LARGE MCS DEVELOPED ALONG AND BEHIND A WEAK COLD FRONT RESULTING IN CONSIDERABLE AMOUNTS OF PRECIPITATION ACROSS SOME AREAS IN THE NORTHERN PART OF OUR FORECAST AREA. THE MCS DEVELOPED A STRONG OUTFLOW BOUNDARY WHICH SURGED THROUGH THE LUBBOCK AREA BEFORE MIDNIGHT AND WAS LOCATED ALONG A SEMINOLE... POST...TO KNOX CITY LINE AT 3 AM. THIS LEAVES ONLY STONEWALL COUNTY TO THE SOUTHEAST OF THE OUTFLOW BOUNDARY. ALOFT...THE 00Z UPPER-AIR ANALYSIS SHOWS THE CENTER OF THE HIGH PRESSURE RIDGE HAS SHIFTED A BIT FURTHER SOUTH OVER SOUTH CENTRAL TEXAS WITH A GOOD MONSOON MOISTURE PLUME LOCATED ACROSS NEW MEXICO CURVING BACK OVER THE TEXAS PANHANDLE. IT WAS TOUGH TO PICK OUT ANY FORM OF SHORTWAVE ACTIVITY IN THE UPPER-AIR ANALYSIS AND THE MCS HAS PUMPED CONSIDERABLE MOISTURE INTO THE ATMOSPHERE AS SHOWN IN THE WATER VAPOR LOOP...ALSO MASKING ANY SHORTWAVES THAT MAY BE SEEN OVER THE TEXAS PANHANDLE. IT DOES HOWEVER SHOW A WEAK SWIRL OVER WESTERN NEW MEXICO THAT WILL BE MOVING TOWARDS THE TEXAS PANHANDLE THROUGH THE DAY WHICH MAY COME INTO PLAY LATER ON. MODELS DID A POOR JOB INITIALIZING WITH THE CONVECTION AT 00Z WHICH COMPLICATES THE FORECAST. THE ONLY MODEL THAT SEEMINGLY HAS A DECENT START IS THE TTU-WRF AND LEANED HEAVILY TOWARDS THIS MODEL FOR THE FORECAST THIS MORNING. THE MCS HAS ALREADY PUSHED EAST OUT OF THE TEXAS PANHANDLE WITH OTHER LIGHTER SHOWER AND ISOLATED THUNDERSTORMS DEVELOPING ACROSS THE WESTERN SOUTH PLAINS GENERALLY ALONG AND WEST OF A TULIA TO BROWNFIELD LINE. TTU-WRF AND TO SOME EXTENT THE NAM...HRRR...AND GFS DECREASE COVERAGE OF ACTIVITY THROUGH THIS MORNING WITH A LULL IN PRECIPITATION BY MID-DAY. EVENTUALLY...THE TTU-WRF REDEVELOPS SCATTERED CONVECTION ACROSS THE WESTERN SOUTH PLAINS BY 21Z AND PUSHES THIS TO THE EAST TOWARDS THE CAPROCK. THIS SOLUTION SEEMS REASONABLE AS CLOUD COVER WILL TAKE A BIT TO DISSIPATE THROUGH THE MORNING AND THEN ALLOW SOME SURFACE- BASED INSTABILITY TO DEVELOP BY THE AFTERNOON. THE WEAK WAVE SEEN IN THE WATER VAPOR LOOP MAY MOVE CLOSE ENOUGH TO PROVIDE SOME WEAK LIFT BUT ALL TOGETHER CONDITIONS REMAIN MARGINAL FOR WIDESPREAD STORMS. FORECAST SOUNDINGS ACROSS THE AREA SHOW QUITE THE RANGE OF SBCAPE VALUES RANGING FROM SUB 500 J/KG IN THE NAM AND TTU-WRF TO ALMOST 2500 J/KG IN THE HRRR AND RAP. IF STORMS DO DEVELOP...COULD ONCE AGAIN SEE A MARGINAL SEVERE WEATHER THREAT MAINLY IN THE FORM OF DOWNBURSTS. ALL THIS PUT TOGETHER MEANS THAT HIGH TEMPERATURES WERE UNDERCUT ACROSS THE NORTHERN SOUTH PLAINS WHERE THE HEAVIEST RAINFALL FELL LAST NIGHT/EARLY THIS MORNING AS SURFACE MOISTURE AND REMNANT CLOUD COVER SHOULD HELP TO MODERATE TEMPERATURES SOME. THE REST OF THE AREA SHOULD SEE TEMPERATURES A FEW DEGREES COOLER THAN YESTERDAY BUT STILL IN THE MID TO UPPER 90S. CHANCE FOR PRECIP WILL INITIALLY BE HIGHEST THIS MORNING...A LULL IN THE LATE MORNING EARLY AFTERNOON... THEN PICKING UP AGAIN LATE THIS AFTERNOON FOR THE SOUTH PLAINS. THE ROLLING PLAINS LOOKS TO BE TOO FAR TO THE EAST TO SEE MUCH IN THE WAY OF PRECIP AS THE FRONT/OUTFLOW BOUNDARY IS HARD TO FIND AND ALL MODELS KEEP THE EASTERN ONE THIRD OF THE FORECAST AREA DRY. ONLY UNCERTAINTY IS HOW LONG POPS WILL GO PAST MIDNIGHT AS THE TTU-WRF TRIES TO DEVELOP ANOTHER WEAK MESOSCALE CONVECTIVE COMPLEX AROUND SUNSET BUT THEN DISSIPATES IT BY MIDNIGHT LOCAL TIME BEFORE IT MAKES IT TO THE EDGE OF THE CAPROCK. A DECENT LOW-LEVEL JET IS FORECAST TO DEVELOP OVERNIGHT WHICH MAY HELP TO KEEP CONVECTION GOING BUT IT WILL VEER BETWEEN 06 AND 12Z FROM SOUTH TO SOUTHWEST...NOT GOOD FOR MAINTENANCE OF ANY CONVECTION THAT DEVELOPS. JORDAN LONG TERM... SEMI-ACTIVE PATTERN AT PRESENT LOOKS TO PERSIST AT LEAST ONE MORE DAY BEFORE A SUBTROPICAL HIGH RE-EXERTS ITSELF SQUARELY ATOP THE ROLLING PLAINS FROM THURSDAY AND LASTING THROUGH EARLY NEXT WEEK. UNTIL THAT MONOTONOUS PATTERN IS REALIZED...A RESIDUAL LAYER OF MOISTURE AND SLIGHTLY COOLER TEMPS ALOFT WILL PERSIST PARTICULARLY ACROSS EASTERN NM AND OUR WESTERN ZONES ON WEDNESDAY. BROAD SURFACE TROUGHING JUST WEST OF THE STATE LINE ALONG WITH WEAK UPSLOPE FLOW SHOULD HELP TRIGGER SOME AFTN/EVNG STORMS...BUT POPS ELSEWHERE ON WEDNESDAY WERE TRIMMED BELOW MENTION AS HEIGHT FIELDS ARE PROGGED TO RISE ABOUT 20 METERS THROUGHOUT THE DAY WHICH IMPLIES TOO MUCH SUBSIDENCE FOR PRECIP IN THIS OTHERWISE WEAKLY FORCED PATTERN. BY THURSDAY...LARGE SCALE SUBSIDENCE WILL TAKE GRASP AREA WIDE WITH ONLY A FEW MORSELS OF PRECIP POSSIBLE ALONG THE WESTERN PERIPHERY OF THE HIGH - BUT EVEN THESE ARE NOW SHAPING UP MORE CONDITIONAL THAN EARLIER MODELS INDICATED SO WE HAVE REMOVED MEASURABLE PRECIP MENTION ON THURSDAY ACROSS OUR WESTERN COUNTIES. THEREAFTER...JUST MINOR DAILY OSCILLATIONS OF THE HIGH/S CENTER ARE THE ONLY CHANGES EXPECTED WITH NEGLIGIBLE IMPACTS ON HIGH TEMPS. CONSIDERING MODELS KEEP 500 MB MAX HEIGHTS AOB 596 DAM... HIGHS SHOULD NOT PUSH TOO FAR ABOVE CLIMO DESPITE THE OBVIOUS WARM BIAS STILL PLAGUING MOS. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 91 66 92 / 30 20 20 10 TULIA 66 92 69 93 / 30 10 10 10 PLAINVIEW 68 91 70 92 / 30 10 10 0 LEVELLAND 68 93 71 93 / 30 20 20 10 LUBBOCK 72 94 72 95 / 30 20 10 0 DENVER CITY 69 94 70 93 / 30 20 20 10 BROWNFIELD 69 94 71 94 / 30 20 20 0 CHILDRESS 72 98 73 99 / 30 10 10 0 SPUR 70 94 73 94 / 20 10 10 0 ASPERMONT 72 98 75 99 / 10 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 51/01/
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
644 AM CDT TUE JUL 21 2015 .AVIATION... VFR CONDITIONS IN PLACE AT ALL TERMINALS. THERE IS A POSSIBILITY OF ANOTHER ROUND OF STORMS IMPACTING KLBB AND KPVW THIS AFTERNOON AND A PROB30 HAS BEEN INTRODUCED TO TAKE THIS INTO ACCOUNT. KCDS SHOULD BE FAR ENOUGH EAST THAT THE THREAT OF STORMS IS FAIRLY SMALL. CONFIDENCE IN TIMING IS NOT VERY HIGH SO EXPECT TO SEE ADJUSTMENTS IN TIMING FOR STORMS THROUGH THE DAY. VFR CONDITIONS EXPECTED OVERNIGHT TONIGHT INTO WEDNESDAY MORNING AS WELL. JORDAN && .PREV DISCUSSION... /ISSUED 400 AM CDT TUE JUL 21 2015/ SHORT TERM... AS WAS EXPECTED...A FAIRLY LARGE MCS DEVELOPED ALONG AND BEHIND A WEAK COLD FRONT RESULTING IN CONSIDERABLE AMOUNTS OF PRECIPITATION ACROSS SOME AREAS IN THE NORTHERN PART OF OUR FORECAST AREA. THE MCS DEVELOPED A STRONG OUTFLOW BOUNDARY WHICH SURGED THROUGH THE LUBBOCK AREA BEFORE MIDNIGHT AND WAS LOCATED ALONG A SEMINOLE... POST...TO KNOX CITY LINE AT 3 AM. THIS LEAVES ONLY STONEWALL COUNTY TO THE SOUTHEAST OF THE OUTFLOW BOUNDARY. ALOFT...THE 00Z UPPER-AIR ANALYSIS SHOWS THE CENTER OF THE HIGH PRESSURE RIDGE HAS SHIFTED A BIT FURTHER SOUTH OVER SOUTH CENTRAL TEXAS WITH A GOOD MONSOON MOISTURE PLUME LOCATED ACROSS NEW MEXICO CURVING BACK OVER THE TEXAS PANHANDLE. IT WAS TOUGH TO PICK OUT ANY FORM OF SHORTWAVE ACTIVITY IN THE UPPER-AIR ANALYSIS AND THE MCS HAS PUMPED CONSIDERABLE MOISTURE INTO THE ATMOSPHERE AS SHOWN IN THE WATER VAPOR LOOP...ALSO MASKING ANY SHORTWAVES THAT MAY BE SEEN OVER THE TEXAS PANHANDLE. IT DOES HOWEVER SHOW A WEAK SWIRL OVER WESTERN NEW MEXICO THAT WILL BE MOVING TOWARDS THE TEXAS PANHANDLE THROUGH THE DAY WHICH MAY COME INTO PLAY LATER ON. MODELS DID A POOR JOB INITIALIZING WITH THE CONVECTION AT 00Z WHICH COMPLICATES THE FORECAST. THE ONLY MODEL THAT SEEMINGLY HAS A DECENT START IS THE TTU-WRF AND LEANED HEAVILY TOWARDS THIS MODEL FOR THE FORECAST THIS MORNING. THE MCS HAS ALREADY PUSHED EAST OUT OF THE TEXAS PANHANDLE WITH OTHER LIGHTER SHOWER AND ISOLATED THUNDERSTORMS DEVELOPING ACROSS THE WESTERN SOUTH PLAINS GENERALLY ALONG AND WEST OF A TULIA TO BROWNFIELD LINE. TTU-WRF AND TO SOME EXTENT THE NAM...HRRR...AND GFS DECREASE COVERAGE OF ACTIVITY THROUGH THIS MORNING WITH A LULL IN PRECIPITATION BY MID-DAY. EVENTUALLY...THE TTU-WRF REDEVELOPS SCATTERED CONVECTION ACROSS THE WESTERN SOUTH PLAINS BY 21Z AND PUSHES THIS TO THE EAST TOWARDS THE CAPROCK. THIS SOLUTION SEEMS REASONABLE AS CLOUD COVER WILL TAKE A BIT TO DISSIPATE THROUGH THE MORNING AND THEN ALLOW SOME SURFACE- BASED INSTABILITY TO DEVELOP BY THE AFTERNOON. THE WEAK WAVE SEEN IN THE WATER VAPOR LOOP MAY MOVE CLOSE ENOUGH TO PROVIDE SOME WEAK LIFT BUT ALL TOGETHER CONDITIONS REMAIN MARGINAL FOR WIDESPREAD STORMS. FORECAST SOUNDINGS ACROSS THE AREA SHOW QUITE THE RANGE OF SBCAPE VALUES RANGING FROM SUB 500 J/KG IN THE NAM AND TTU-WRF TO ALMOST 2500 J/KG IN THE HRRR AND RAP. IF STORMS DO DEVELOP...COULD ONCE AGAIN SEE A MARGINAL SEVERE WEATHER THREAT MAINLY IN THE FORM OF DOWNBURSTS. ALL THIS PUT TOGETHER MEANS THAT HIGH TEMPERATURES WERE UNDERCUT ACROSS THE NORTHERN SOUTH PLAINS WHERE THE HEAVIEST RAINFALL FELL LAST NIGHT/EARLY THIS MORNING AS SURFACE MOISTURE AND REMNANT CLOUD COVER SHOULD HELP TO MODERATE TEMPERATURES SOME. THE REST OF THE AREA SHOULD SEE TEMPERATURES A FEW DEGREES COOLER THAN YESTERDAY BUT STILL IN THE MID TO UPPER 90S. CHANCE FOR PRECIP WILL INITIALLY BE HIGHEST THIS MORNING...A LULL IN THE LATE MORNING EARLY AFTERNOON... THEN PICKING UP AGAIN LATE THIS AFTERNOON FOR THE SOUTH PLAINS. THE ROLLING PLAINS LOOKS TO BE TOO FAR TO THE EAST TO SEE MUCH IN THE WAY OF PRECIP AS THE FRONT/OUTFLOW BOUNDARY IS HARD TO FIND AND ALL MODELS KEEP THE EASTERN ONE THIRD OF THE FORECAST AREA DRY. ONLY UNCERTAINTY IS HOW LONG POPS WILL GO PAST MIDNIGHT AS THE TTU-WRF TRIES TO DEVELOP ANOTHER WEAK MESOSCALE CONVECTIVE COMPLEX AROUND SUNSET BUT THEN DISSIPATES IT BY MIDNIGHT LOCAL TIME BEFORE IT MAKES IT TO THE EDGE OF THE CAPROCK. A DECENT LOW-LEVEL JET IS FORECAST TO DEVELOP OVERNIGHT WHICH MAY HELP TO KEEP CONVECTION GOING BUT IT WILL VEER BETWEEN 06 AND 12Z FROM SOUTH TO SOUTHWEST...NOT GOOD FOR MAINTENANCE OF ANY CONVECTION THAT DEVELOPS. JORDAN LONG TERM... SEMI-ACTIVE PATTERN AT PRESENT LOOKS TO PERSIST AT LEAST ONE MORE DAY BEFORE A SUBTROPICAL HIGH RE-EXERTS ITSELF SQUARELY ATOP THE ROLLING PLAINS FROM THURSDAY AND LASTING THROUGH EARLY NEXT WEEK. UNTIL THAT MONOTONOUS PATTERN IS REALIZED...A RESIDUAL LAYER OF MOISTURE AND SLIGHTLY COOLER TEMPS ALOFT WILL PERSIST PARTICULARLY ACROSS EASTERN NM AND OUR WESTERN ZONES ON WEDNESDAY. BROAD SURFACE TROUGHING JUST WEST OF THE STATE LINE ALONG WITH WEAK UPSLOPE FLOW SHOULD HELP TRIGGER SOME AFTN/EVNG STORMS...BUT POPS ELSEWHERE ON WEDNESDAY WERE TRIMMED BELOW MENTION AS HEIGHT FIELDS ARE PROGGED TO RISE ABOUT 20 METERS THROUGHOUT THE DAY WHICH IMPLIES TOO MUCH SUBSIDENCE FOR PRECIP IN THIS OTHERWISE WEAKLY FORCED PATTERN. BY THURSDAY...LARGE SCALE SUBSIDENCE WILL TAKE GRASP AREA WIDE WITH ONLY A FEW MORSELS OF PRECIP POSSIBLE ALONG THE WESTERN PERIPHERY OF THE HIGH - BUT EVEN THESE ARE NOW SHAPING UP MORE CONDITIONAL THAN EARLIER MODELS INDICATED SO WE HAVE REMOVED MEASURABLE PRECIP MENTION ON THURSDAY ACROSS OUR WESTERN COUNTIES. THEREAFTER...JUST MINOR DAILY OSCILLATIONS OF THE HIGH/S CENTER ARE THE ONLY CHANGES EXPECTED WITH NEGLIGIBLE IMPACTS ON HIGH TEMPS. CONSIDERING MODELS KEEP 500 MB MAX HEIGHTS AOB 596 DAM... HIGHS SHOULD NOT PUSH TOO FAR ABOVE CLIMO DESPITE THE OBVIOUS WARM BIAS STILL PLAGUING MOS. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 85 64 91 66 / 40 30 20 20 TULIA 86 66 92 69 / 40 30 10 10 PLAINVIEW 89 68 91 70 / 40 30 10 10 LEVELLAND 92 68 93 71 / 40 30 20 20 LUBBOCK 92 72 94 72 / 30 30 20 10 DENVER CITY 93 69 94 70 / 40 30 20 20 BROWNFIELD 93 69 94 71 / 30 30 20 20 CHILDRESS 96 72 98 73 / 30 30 10 10 SPUR 94 70 94 73 / 10 20 10 10 ASPERMONT 98 72 98 75 / 10 10 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 14/93/14
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
642 AM CDT Tue Jul 21 2015 .AVIATION... /12Z TAFS/ The low clouds over the Hill Country dissipated this morning before reaching KJCT. This will spell VFR conditions across the forecast area through the TAF period. Expect south winds around 10 kts this afternoon with a high based cu field (8,000-10,000 ft) developing by midday. A few of the hi-res models continue to indicate isolated convection this afternoon, mainly west of a KSWW-KSJT line. However, any cells that develop should remain to the north and west of the forecast terminals. Johnson && .PREV DISCUSSION... /ISSUED 411 AM CDT Tue Jul 21 2015/ SHORT TERM... (Today and tonight) One shortwave trough is lifting northeast across NM this morning, providing large scale forcing for ascent across the Panhandle and portions of west TX. At the surface, a cold front was located from the south plains, extending northeast into central OK. Outflow from evening convection is forcing the effective front to the southeast, from near Vernon, to Jayton, to Midland as of 3 AM. This boundary will likely move into the Big Country and western Concho Valley this morning but is expected to erode by midday, given the shallow nature of the "cool" airmass. This should have only a slight effect on temperatures this afternoon, mainly over the northwest quadrant of the CWA. Expect highs ranging from the upper 90s to near 102 degrees this afternoon, with similar heat indices. A second shortwave trough is progged to lift northeast across NM this afternoon and evening, providing another round of convection to our north and west. The HRRR and ARW both indicate isolated convection along the western periphery of the CWA this afternoon, but the NAM, GFS, and ECMWF are largely dry. While a rogue shower/storm can`t be ruled out this afternoon, coverage should be significantly limited given the warm temps aloft, weak cap, and depth of the boundary layer (increasing dry air entrainment into potential updrafts). Thus, no PoPs will be carried in the forecast. Expect partly cloudy conditions overnight with overnight lows in the mid 70s. Johnson LONG TERM... (Wednesday through next Monday) By Wednesday, the frontal zone currently currently extending from the TX panhandle into Oklahoma will be lifting northward into the central plains. On Thursday, the upper level ridge will re-center and strengthen directly over west Texas. With the ridge in place across the southern plains through early next week, persistent southwesterly flow across the Rocky Mountains will result in lee troughing, and continue warm, southerly flow for our area through the extended period. Due to this ridging and persistent southerly flow, 850mb temperatures will warm a degree or two Celsius by Monday. This will result in persistent hot and dry weather for our area with highs in the upper 90s to around 100 degrees, lows in the mid to upper 70s, and no chance for rainfall. && .PRELIMINARY POINT TEMPS/POPS... Abilene 98 76 98 76 98 / 5 5 0 0 0 San Angelo 102 75 100 76 99 / 0 0 0 0 0 Junction 100 74 98 74 97 / 0 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 25
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
639 AM CDT TUE JUL 21 2015 .AVIATION... /12Z TAFS/ CONCERNS...NONE. VFR WILL PREVAIL. VFR CONDITIONS WILL PREVAIL WITH GENERALLY SOUTH WINDS AOB 12 KTS. THERE WILL BE SOME VARIANCE IN THE WIND DIRECTION BETWEEN SOUTH-SOUTHWEST TO SOUTH-SOUTHEAST...BUT FOR MOST OF THE PERIOD THE WINDS WILL PREVAIL FROM THE SOUTH. HIGH CLOUDS THIS MORNING FROM RAIN IN OKLAHOMA WILL RESULT IN SCT-BKN SKIES THIS MORNING. AN ISOLATED SHOWER MAY DEVELOP ALONG AN OUTFLOW BOUNDARY MOVING ACROSS NORTHWEST TEXAS TOWARDS DFW BUT THE UPPER LEVEL RIDGE WILL LIKELY SUPPRESS ANY CONVECTION ALONG THIS BOUNDARY. JLDUNN && .PREV DISCUSSION... /ISSUED 328 AM CDT TUE JUL 21 2015/ THE UPPER LEVEL RIDGE THAT HAS DOMINATED THE WEATHER ACROSS THE REGION FOR THE LAST WEEK IS SHOWING SOME SIGNS OF A SLIGHT WEAKENING AS A SHORT WAVE MOVES ACROSS ITS NORTHERN PERIPHERY. THIS HAS ALLOWED A COLD FRONT TO MOVE DOWN INTO NORTHERN OKLAHOMA AND WEST TEXAS. THIS FRONT WILL STALL OUT ACROSS CENTRAL OKLAHOMA INTO WEST TEXAS THIS AFTERNOON OR EVENING BEFORE LIFTING BACK TO THE NORTH BY WEDNESDAY MORNING. SOME OF THE HIGH CLOUDS ASSOCIATED WITH CONVECTION ACROSS OKLAHOMA AND THE TEXAS PANHANDLE WILL ATTEMPT TO MOVE INTO NORTH TODAY BUT THESE CLOUDS SHOULD THIN. THE MAIN AREA OF DENSER CLOUDS WILL MOVE EAST ACROSS OKLAHOMA. TEMPERATURES TODAY SHOULD BE A DEGREE OR TWO COOLER VERSUS YESTERDAY THANKS TO THE WEAKENING RIDGE. EXPECT HIGHS IN THE MID 90S TO NEAR 100 DEGREES ACROSS THE REGION. THE HRRR INDICATES THAT SOME ISOLATED SHOWERS/THUNDERSTORMS WILL TRY TO FORM THIS AFTERNOON FROM GRANBURY THROUGH THE METROPLEX NORTHEAST TOWARD PARIS. THE SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL PROBABLY BE TOO STRONG FOR THIS TO OCCUR SO HAVE JUST PLACED 10 PERCENT POPS WITH NO WEATHER MENTIONED FOR THIS AFTERNOON AND EVENING ALONG AND NORTH OF A COMANCHE TO EMORY LINE. THE UPPER RIDGE WILL SHIFT WEST INTO WEST TEXAS AND RE-STRENGTHEN LATE WEEK. THIS WILL ALLOW TEMPERATURES TO INCREASE BY A FEW DEGREES LATE WEEK THROUGH THE WEEKEND. WE MAY BE REACH HEAT ADVISORY CRITERIA ACROSS THE EASTERN THIRD TO HALF SUNDAY/MONDAY. THE ECMWF AND GFS INDICATE THAT THE RIDGE WILL SHIFT A LITTLE TO THE NORTH EARLY TO MID NEXT WEEK...WHICH MAY ALLOW FOR SOME LOW RAIN CHANCES ACROSS THE SOUTHEASTERN AND SOUTHERN ZONES BY THE MIDDLE OF NEXT WEEK. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 98 79 98 79 99 / 10 5 5 0 0 WACO, TX 97 75 97 75 98 / 0 0 0 0 0 PARIS, TX 97 76 96 75 96 / 10 10 10 0 0 DENTON, TX 98 77 98 78 99 / 10 10 10 0 0 MCKINNEY, TX 96 77 97 78 98 / 10 5 10 0 0 DALLAS, TX 99 80 99 81 100 / 10 5 5 0 0 TERRELL, TX 97 76 96 76 99 / 10 5 5 0 0 CORSICANA, TX 98 76 97 76 99 / 0 0 5 0 0 TEMPLE, TX 97 74 96 75 97 / 0 0 0 0 0 MINERAL WELLS, TX 96 75 96 75 98 / 10 5 5 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 82/58
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
411 AM CDT Tue Jul 21 2015 .SHORT TERM... (Today and tonight) One shortwave trough is lifting northeast across NM this morning, providing large scale forcing for ascent across the Panhandle and portions of west TX. At the surface, a cold front was located from the south plains, extending northeast into central OK. Outflow from evening convection is forcing the effective front to the southeast, from near Vernon, to Jayton, to Midland as of 3 AM. This boundary will likely move into the Big Country and western Concho Valley this morning but is expected to erode by midday, given the shallow nature of the "cool" airmass. This should have only a slight effect on temperatures this afternoon, mainly over the northwest quadrant of the CWA. Expect highs ranging from the upper 90s to near 102 degrees this afternoon, with similar heat indices. A second shortwave trough is progged to lift northeast across NM this afternoon and evening, providing another round of convection to our north and west. The HRRR and ARW both indicate isolated convection along the western periphery of the CWA this afternoon, but the NAM, GFS, and ECMWF are largely dry. While a rogue shower/storm can`t be ruled out this afternoon, coverage should be significantly limited given the warm temps aloft, weak cap, and depth of the boundary layer (increasing dry air entrainment into potential updrafts). Thus, no PoPs will be carried in the forecast. Expect partly cloudy conditions overnight with overnight lows in the mid 70s. Johnson .LONG TERM... (Wednesday through next Monday) By Wednesday, the frontal zone currently currently extending from the TX panhandle into Oklahoma will be lifting northward into the central plains. On Thursday, the upper level ridge will re-center and strengthen directly over west Texas. With the ridge in place across the southern plains through early next week, persistent southwesterly flow across the Rocky Mountains will result in lee troughing, and continue warm, southerly flow for our area through the extended period. Due to this ridging and persistent southerly flow, 850mb temperatures will warm a degree or two Celsius by Monday. This will result in persistent hot and dry weather for our area with highs in the upper 90s to around 100 degrees, lows in the mid to upper 70s, and no chance for rainfall. && .PRELIMINARY POINT TEMPS/POPS... Abilene 98 76 98 76 98 / 5 5 0 0 0 San Angelo 102 75 100 76 99 / 0 0 0 0 0 Junction 100 74 98 74 97 / 0 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
400 AM CDT TUE JUL 21 2015 .SHORT TERM... AS WAS EXPECTED...A FAIRLY LARGE MCS DEVELOPED ALONG AND BEHIND A WEAK COLD FRONT RESULTING IN CONSIDERABLE AMOUNTS OF PRECIPITATION ACROSS SOME AREAS IN THE NORTHERN PART OF OUR FORECAST AREA. THE MCS DEVELOPED A STRONG OUTFLOW BOUNDARY WHICH SURGED THROUGH THE LUBBOCK AREA BEFORE MIDNIGHT AND WAS LOCATED ALONG A SEMINOLE... POST...TO KNOX CITY LINE AT 3 AM. THIS LEAVES ONLY STONEWALL COUNTY TO THE SOUTHEAST OF THE OUTFLOW BOUNDARY. ALOFT...THE 00Z UPPER-AIR ANALYSIS SHOWS THE CENTER OF THE HIGH PRESSURE RIDGE HAS SHIFTED A BIT FURTHER SOUTH OVER SOUTH CENTRAL TEXAS WITH A GOOD MONSOON MOISTURE PLUME LOCATED ACROSS NEW MEXICO CURVING BACK OVER THE TEXAS PANHANDLE. IT WAS TOUGH TO PICK OUT ANY FORM OF SHORTWAVE ACTIVITY IN THE UPPER-AIR ANALYSIS AND THE MCS HAS PUMPED CONSIDERABLE MOISTURE INTO THE ATMOSPHERE AS SHOWN IN THE WATER VAPOR LOOP...ALSO MASKING ANY SHORTWAVES THAT MAY BE SEEN OVER THE TEXAS PANHANDLE. IT DOES HOWEVER SHOW A WEAK SWIRL OVER WESTERN NEW MEXICO THAT WILL BE MOVING TOWARDS THE TEXAS PANHANDLE THROUGH THE DAY WHICH MAY COME INTO PLAY LATER ON. MODELS DID A POOR JOB INITIALIZING WITH THE CONVECTION AT 00Z WHICH COMPLICATES THE FORECAST. THE ONLY MODEL THAT SEEMINGLY HAS A DECENT START IS THE TTU-WRF AND LEANED HEAVILY TOWARDS THIS MODEL FOR THE FORECAST THIS MORNING. THE MCS HAS ALREADY PUSHED EAST OUT OF THE TEXAS PANHANDLE WITH OTHER LIGHTER SHOWER AND ISOLATED THUNDERSTORMS DEVELOPING ACROSS THE WESTERN SOUTH PLAINS GENERALLY ALONG AND WEST OF A TULIA TO BROWNFIELD LINE. TTU-WRF AND TO SOME EXTENT THE NAM...HRRR...AND GFS DECREASE COVERAGE OF ACTIVITY THROUGH THIS MORNING WITH A LULL IN PRECIPITATION BY MID-DAY. EVENTUALLY...THE TTU-WRF REDEVELOPS SCATTERED CONVECTION ACROSS THE WESTERN SOUTH PLAINS BY 21Z AND PUSHES THIS TO THE EAST TOWARDS THE CAPROCK. THIS SOLUTION SEEMS REASONABLE AS CLOUD COVER WILL TAKE A BIT TO DISSIPATE THROUGH THE MORNING AND THEN ALLOW SOME SURFACE- BASED INSTABILITY TO DEVELOP BY THE AFTERNOON. THE WEAK WAVE SEEN IN THE WATER VAPOR LOOP MAY MOVE CLOSE ENOUGH TO PROVIDE SOME WEAK LIFT BUT ALL TOGETHER CONDITIONS REMAIN MARGINAL FOR WIDESPREAD STORMS. FORECAST SOUNDINGS ACROSS THE AREA SHOW QUITE THE RANGE OF SBCAPE VALUES RANGING FROM SUB 500 J/KG IN THE NAM AND TTU-WRF TO ALMOST 2500 J/KG IN THE HRRR AND RAP. IF STORMS DO DEVELOP...COULD ONCE AGAIN SEE A MARGINAL SEVERE WEATHER THREAT MAINLY IN THE FORM OF DOWNBURSTS. ALL THIS PUT TOGETHER MEANS THAT HIGH TEMPERATURES WERE UNDERCUT ACROSS THE NORTHERN SOUTH PLAINS WHERE THE HEAVIEST RAINFALL FELL LAST NIGHT/EARLY THIS MORNING AS SURFACE MOISTURE AND REMNANT CLOUD COVER SHOULD HELP TO MODERATE TEMPERATURES SOME. THE REST OF THE AREA SHOULD SEE TEMPERATURES A FEW DEGREES COOLER THAN YESTERDAY BUT STILL IN THE MID TO UPPER 90S. CHANCE FOR PRECIP WILL INITIALLY BE HIGHEST THIS MORNING...A LULL IN THE LATE MORNING EARLY AFTERNOON... THEN PICKING UP AGAIN LATE THIS AFTERNOON FOR THE SOUTH PLAINS. THE ROLLING PLAINS LOOKS TO BE TOO FAR TO THE EAST TO SEE MUCH IN THE WAY OF PRECIP AS THE FRONT/OUTFLOW BOUNDARY IS HARD TO FIND AND ALL MODELS KEEP THE EASTERN ONE THIRD OF THE FORECAST AREA DRY. ONLY UNCERTAINTY IS HOW LONG POPS WILL GO PAST MIDNIGHT AS THE TTU-WRF TRIES TO DEVELOP ANOTHER WEAK MESOSCALE CONVECTIVE COMPLEX AROUND SUNSET BUT THEN DISSIPATES IT BY MIDNIGHT LOCAL TIME BEFORE IT MAKES IT TO THE EDGE OF THE CAPROCK. A DECENT LOW-LEVEL JET IS FORECAST TO DEVELOP OVERNIGHT WHICH MAY HELP TO KEEP CONVECTION GOING BUT IT WILL VEER BETWEEN 06 AND 12Z FROM SOUTH TO SOUTHWEST...NOT GOOD FOR MAINTENANCE OF ANY CONVECTION THAT DEVELOPS. JORDAN .LONG TERM... SEMI-ACTIVE PATTERN AT PRESENT LOOKS TO PERSIST AT LEAST ONE MORE DAY BEFORE A SUBTROPICAL HIGH RE-EXERTS ITSELF SQUARELY ATOP THE ROLLING PLAINS FROM THURSDAY AND LASTING THROUGH EARLY NEXT WEEK. UNTIL THAT MONOTONOUS PATTERN IS REALIZED...A RESIDUAL LAYER OF MOISTURE AND SLIGHTLY COOLER TEMPS ALOFT WILL PERSIST PARTICULARLY ACROSS EASTERN NM AND OUR WESTERN ZONES ON WEDNESDAY. BROAD SURFACE TROUGHING JUST WEST OF THE STATE LINE ALONG WITH WEAK UPSLOPE FLOW SHOULD HELP TRIGGER SOME AFTN/EVNG STORMS...BUT POPS ELSEWHERE ON WEDNESDAY WERE TRIMMED BELOW MENTION AS HEIGHT FIELDS ARE PROGGED TO RISE ABOUT 20 METERS THROUGHOUT THE DAY WHICH IMPLIES TOO MUCH SUBSIDENCE FOR PRECIP IN THIS OTHERWISE WEAKLY FORCED PATTERN. BY THURSDAY...LARGE SCALE SUBSIDENCE WILL TAKE GRASP AREA WIDE WITH ONLY A FEW MORSELS OF PRECIP POSSIBLE ALONG THE WESTERN PERIPHERY OF THE HIGH - BUT EVEN THESE ARE NOW SHAPING UP MORE CONDITIONAL THAN EARLIER MODELS INDICATED SO WE HAVE REMOVED MEASURABLE PRECIP MENTION ON THURSDAY ACROSS OUR WESTERN COUNTIES. THEREAFTER...JUST MINOR DAILY OSCILLATIONS OF THE HIGH/S CENTER ARE THE ONLY CHANGES EXPECTED WITH NEGLIGIBLE IMPACTS ON HIGH TEMPS. CONSIDERING MODELS KEEP 500 MB MAX HEIGHTS AOB 596 DAM... HIGHS SHOULD NOT PUSH TOO FAR ABOVE CLIMO DESPITE THE OBVIOUS WARM BIAS STILL PLAGUING MOS. && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 14/93
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
328 AM CDT TUE JUL 21 2015 .DISCUSSION... THE UPPER LEVEL RIDGE THAT HAS DOMINATED THE WEATHER ACROSS THE REGION FOR THE LAST WEEK IS SHOWING SOME SIGNS OF A SLIGHT WEAKENING AS A SHORT WAVE MOVES ACROSS ITS NORTHERN PERIPHERY. THIS HAS ALLOWED A COLD FRONT TO MOVE DOWN INTO NORTHERN OKLAHOMA AND WEST TEXAS. THIS FRONT WILL STALL OUT ACROSS CENTRAL OKLAHOMA INTO WEST TEXAS THIS AFTERNOON OR EVENING BEFORE LIFTING BACK TO THE NORTH BY WEDNESDAY MORNING. SOME OF THE HIGH CLOUDS ASSOCIATED WITH CONVECTION ACROSS OKLAHOMA AND THE TEXAS PANHANDLE WILL ATTEMPT TO MOVE INTO NORTH TODAY BUT THESE CLOUDS SHOULD THIN. THE MAIN AREA OF DENSER CLOUDS WILL MOVE EAST ACROSS OKLAHOMA. TEMPERATURES TODAY SHOULD BE A DEGREE OR TWO COOLER VERSUS YESTERDAY THANKS TO THE WEAKENING RIDGE. EXPECT HIGHS IN THE MID 90S TO NEAR 100 DEGREES ACROSS THE REGION. THE HRRR INDICATES THAT SOME ISOLATED SHOWERS/THUNDERSTORMS WILL TRY TO FORM THIS AFTERNOON FROM GRANBURY THROUGH THE METROPLEX NORTHEAST TOWARD PARIS. THE SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL PROBABLY BE TOO STRONG FOR THIS TO OCCUR SO HAVE JUST PLACED 10 PERCENT POPS WITH NO WEATHER MENTIONED FOR THIS AFTERNOON AND EVENING ALONG AND NORTH OF A COMANCHE TO EMORY LINE. THE UPPER RIDGE WILL SHIFT WEST INTO WEST TEXAS AND RE-STRENGTHEN LATE WEEK. THIS WILL ALLOW TEMPERATURES TO INCREASE BY A FEW DEGREES LATE WEEK THROUGH THE WEEKEND. WE MAY BE REACH HEAT ADVISORY CRITERIA ACROSS THE EASTERN THIRD TO HALF SUNDAY/MONDAY. THE ECMWF AND GFS INDICATE THAT THE RIDGE WILL SHIFT A LITTLE TO THE NORTH EARLY TO MID NEXT WEEK...WHICH MAY ALLOW FOR SOME LOW RAIN CHANCES ACROSS THE SOUTHEASTERN AND SOUTHERN ZONES BY THE MIDDLE OF NEXT WEEK. 58 && .AVIATION... /ISSUED 1151 PM CDT MON JUL 20 2015/ NO CHANGE FOR THIS FORECAST. CONTINUED VFR WITH SOUTHERLY WINDS 8-12 KNOTS AND SOME AFTERNOON GUSTS. 75 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 98 79 98 79 99 / 10 5 5 0 0 WACO, TX 97 75 97 75 97 / 0 0 0 0 0 PARIS, TX 97 76 96 75 96 / 10 10 10 0 0 DENTON, TX 98 77 98 78 99 / 10 10 10 0 0 MCKINNEY, TX 96 77 97 78 98 / 10 5 10 0 0 DALLAS, TX 99 80 99 81 100 / 10 5 5 0 0 TERRELL, TX 97 76 96 76 99 / 10 5 5 0 0 CORSICANA, TX 98 76 97 76 99 / 0 0 5 0 0 TEMPLE, TX 97 74 96 75 97 / 0 0 0 0 0 MINERAL WELLS, TX 96 75 96 75 98 / 10 5 5 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 82/58
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1231 AM CDT TUE JUL 21 2015 .AVIATION... 06Z TAFS...VFR CONDITIONS WILL CONTINUE OUTSIDE OF THE INFLUENCE OF PERIODS OF HEAVIER RAIN FROM SCATTERED SHOWERS AND THUNDERSTORMS. THESE STORMS SHOULD CONTINUE TO TAPER OFF FROM WEST TO EAST OVER THE NEXT SEVERAL HOURS...AND WINDS SHOULD RETURN TO MAINLY AN EASTERLY DIRECTION. EXPECT WINDS TO TURN MORE SOUTHEASTERLY ACROSS THE PANHANDLES IN THE AFTERNOON...AND CONVECTION IS AGAIN EXPECTED DURING THE LATE AFTERNOON AND EVENING HOURS. CONFIDENCE IS LOW IN THE TIMING OF SAID CONVECTION AT THE TERMINALS TO GO PREVAILING AT THIS POINT...SO HAVE OPTED FOR PROB30 TO COVER THE MOST LIKELY TIME PERIODS WITH FURTHER REFINEMENT EXPECTED. ELSENHEIMER && .PREV DISCUSSION... /ISSUED 242 PM CDT MON JUL 20 2015/ DISCUSSION... LATEST WATER VAPOR CHANNEL LOOP AND GOES DERIVED TPW SHOWS ANOMALOUS MOISTURE FLOWING NORTHWARD ACROSS EASTERN NEW MEXICO ON THE WESTERN EDGE OF UPPER RIDGE. 12Z SOUNDINGS CONFIRM THIS WITH A SIGNIFICANT INCREASE IN PWAT FROM 00Z LAST NIGHT (1.47 VS 0.82 INCHES). THIS IS APPROACHING 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY. DOWNSTREAM...A SHORTWAVE AND EXTENSIVE CONVECTION CONTINUES TO MOVE EASTWARD OUT OF THE CENTRAL PLAINS TOWARD THE MIDDLE MISSISSIPPI VALLEY WITH WEAK SUBSIDENCE EVIDENT BEHIND IT. VISIBLE SATELLITE REVEALS SOME MID-HIGH LEVEL CLOUDS LEFT IN THE WAKE OF OVERNIGHT CONVECTION AND THIS COULD POTENTIALLY LIMIT DIABATIC HEATING SOME THIS AFTERNOON WITH A TREND TOWARD PARTIAL CLEARING IN THE FAR SOUTH TEXAS PANHANDLE. SUBJECTIVE SURFACE ANALYSIS AT 18Z SHOWS A WEAK COLD FRONT/COMPOSITE OUTFLOW ORIENTED NORTHEAST TO SOUTHWEST FROM NEAR WHEELER TO JUST SOUTH OF CANYON. STORMS HAVE ALREADY FORMED NEAR CLOVIS AND CU/TCU HAS RECENTLY FORMED NEAR THIS BOUNDARY FURTHER EAST ACROSS THE FAR SOUTHERN PORTION OF OUR AREA. THIS SHOULD BE THE INITIAL FOCUS WITH MORE WIDESPREAD CONVECTION OCCURRING LATER THIS EVENING. THE TENDENCY OF MID LEVEL HEIGHTS WILL BE TO FALL SLIGHTLY AS UPPER RIDGE DEAMPLIFIES AND THIS SHOULD SUPPORT GREATER COVERAGE OF CONVECTION THAN HAS BEEN SEEN IN PREVIOUS DAYS. PRESENCE OF ANOMALOUS MOISTURE COMBINED WITH SLOW STORM MOTIONS RAISES CONCERN FOR FLASH FLOODING. FLASH FLOOD GUIDANCE IS AT OR ABOVE CURRENT QPF OUTPUT FROM MOST GUIDANCE. IN THE ABSENCE OF A WELL DEFINED SHORTWAVE TO FOCUS DEVELOPMENT BELIEVE THAT THE IMPACTS WOULD BE LOCALIZED. SOME OF THE SHORT RANGE HI-RES GUIDANCE AMOUNTS ARE MORE AGGRESSIVE BUT THERE IS SOME QUESTION ABOUT HOW MUCH OF THIS IS INFLUENCED BY THE BAD AWOS OBSERVATION AT PLAINVIEW/KPVW. THIS IS GETTING INTO THE RAP AND HAS CONSISTENTLY RESULTED IN A SPURIOUS 7000+ CAPE BULLSEYE IN THE SOUTH TEXAS PANHANDLE THE LAST SEVERAL DAYS. CAM GUIDANCE NESTED WITHIN THE RAP SUCH AS THE HRRR MAY BE EXAGGERATED WITH CONVECTIVE COVERAGE AND QPF AS A RESULT. SEVERE THUNDERSTORMS ARE A SECONDARY CONCERN TODAY ALTHOUGH DEEP LAYER SHEAR SHOULD BE TOO WEAK TO SUPPORT SUSTAINED UPDRAFTS. SEVERE EPISODES SHOULD BE BRIEF AND MARGINAL. MID LEVEL LAPSE RATES ARE NOT PARTICULARLY STEEP WHICH IS TYPICAL FOR THIS MONSOON PATTERN BUT ARE STEEP ENOUGH TO SUPPORT AROUND 1000 J/KG CAPE IN THE HAIL GROWTH ZONE. ISOLATED OCCURRENCES OF MARGINALLY SEVERE HAIL ARE POSSIBLE BUT MODERATE INSTABILITY AND WEAK SHEAR SUPPORTING FAIRLY INTENSE BUT VERTICAL UPDRAFTS WITH WATER LOADING BENEATH STEEPENING LOW LEVEL LAPSE RATES SHOULD SUPPORT PRIMARILY A WIND THREAT FROM BRIEF DOWNBURSTS LATE THIS AFTERNOON THROUGH AT LEAST MID EVENING. OVERNIGHT...WEAK ASCENT IS DEPICTED BY THE MODELS ON THE 315K SURFACE WHICH IS FAIRLY MOIST AND THIS SHOULD BE ENOUGH TO SUSTAIN CHANCES FOR CONVECTION INTO THE NIGHT AND IN A WEAKENED STATE PROBABLY EVEN INTO THE MORNING HOURS ESPECIALLY ACROSS THE EAST. SIMILAR CHALLENGES TO TODAY ARE EXPECTED TOMORROW WITH OVERNIGHT CONVECTION AND MESOSCALE BOUNDARIES/RESIDUAL CLOUDS MAKING SPATIAL AND TEMPORAL DETAILS UNCLEAR AT THIS POINT. FORECAST CONFIDENCE SHOULD INCREASE LATER TONIGHT AND BY MORNING AS WE MONITOR HOW EVENING/OVERNIGHT CONVECTION EVOLVES. STARTING WEDNESDAY MID LEVEL HEIGHTS RISE AS UPPER HIGH BUILDS NORTH/NORTHWESTWARD ONCE AGAIN RESULTING IN DRY WEATHER AND WARMER TEMPERATURES THROUGH AT LEAST THE END OF THE WEEK. TOWARD SATURDAY MEDIUM RANGE GUIDANCE CONSENSUS IS FOR RIDGE FLATTENS AGAIN AND MEAN WEST-NORTHWESTERLY FLOW MAY BE ENOUGH FOR CONVECTION TO MOVE INTO AT LEAST WESTERN AND NORTHERN SECTIONS. BRB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 18/11
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
145 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1255 PM EDT TUESDAY... THERE HAS BEEN A SMALL UPSWING IN THE AMOUNT OF CONVECTION FIRING ACROSS THE REGION. THERE IS NOW A GREATER CONCENTRATION OF SHOWERS ACROSS THE WESTERN PORTION OF THE REGION. MOST OF THE ACTIVITY IS VERY SMALL IN SIZE...AND NO LIGHTNING HAS OCCURRED YET. FAR EASTERN PARTS OF THE AREA REMAIN THE REGION TO WATCH FOR DEEPER CONVECTION ONCE IT BEGINS...GIVEN THIS REGION WAS NOT IMPACTED BY THIS RAIN SHIELD FROM THIS MORNING...AND MOST OF THE DAY HAS HAD AT LEAST SOME SUNSHINE REACHING THE GROUND. AM EXPECTING THE BEST COVERAGE...AND STRONGEST ACTIVITY TO BE IN THIS EASTERN AREA BY THE MID TO LATE AFTERNOON. ONCE WE REACH THIS EVENING...COVERAGE WILL BE CONFINED TO MAINLY THE SOUTHEAST PART OF THE REGION...WITH AN INCREASE IN THE NORTHWEST AS THE COLD FRONT MOVES INTO THE AREA. NO MAJOR CHANGE TO THE FORECAST HIGH TEMPERATURES AS MOST ARE ON TRACK TO BE WITHIN A DEGREE OR TWO OF CURRENTLY FORECAST NUMBERS. AS OF 1010 AM EDT TUESDAY... CONVECTIVE CLUSTER FROM THIS MORNING HAS DISSIPATED INTO A PATCHY AREA OF LIGHT RAIN...AND HAS EXITED THE NORTHEAST PART OF THE FORECAST AREA. HEADING INTO THIS AFTERNOON...MUCH OF THE REGION WILL BE RELATIVELY STABLE...BEING TEMPORARILY CAPPED FROM THE EARLIER CONVECTION AND SLOW TO HEAT AT THE SURFACE TO DO PLENTY OF REMAINING DEBRIS CLOUD COVER. LATER THIS AFTERNOON WITH THE APPROACH AND ARRIVAL OF A COLD FRONT IS WHEN THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD REVAMP ITS COVERAGE. HOWEVER...THE LATEST VERSION OF THE FORECAST WILL BE DOWNPLAYING THE CHANCE OF PRECIPITATION A BIT AS COMPARED TO THE EARLIER NUMBERS THANKS TO THE AFOREMENTIONED NEGATIVE INFLUENCES TO CONVECTION. AS OF 400 AM EDT TUESDAY... A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY CROSS THE BLUE RIDGE. A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT... SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF. WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY MORNING. STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY ADVISORY. AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER 50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE WATER VALUES DROPPING BELOW ONE HALF INCH. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EDT TUESDAY... BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION. DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER 70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE PIEDMONT. AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70 DEGREES IN THE PIEDMONT. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 350 PM EDT MONDAY... THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST. 500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST. CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT. TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 140 PM EDT TUESDAY... ONLY LIGHT REFLECTIVITY ON THE SCOPE EARLY THIS AFTERNOON. PIEDMONT TAF SITES...INCLUDING KROA...CURRENTLY SITTING AT VFR WHILE KBCB/KBLF/KLWB REMAIN IN MVFR CATEGORY DUE TO LOW CIG. EXPECT AT WORST MVFR CONDITIONS OVER THE NEXT FEW HOURS AS LIGHT PRECIPITATION CONTINUES TO PUSH THROUGH THE WESTERN PORTIONS OF OUR FORECAST AREA AHEAD OF THE COLD FRONT. MAIN SOURCE OF UNCERTAINTY LIES AROUND THE TIMING AND STRENGTH OF THE FRONTAL PASSAGE. DUE TO REMNANT CLOUDCOVER FROM A DECAYING MCS THAT PUSHED INTO THE FORECAST AREA EARLIER THIS MORNING...ISOLATED TO SCATTERED SHOWERS ARE EXPECTED FOR OUR WESTERN MOST TAF LOCATIONS. THUNDERSTORMS ARE STILL POSSIBLE IN THE EAST WHERE INSTABILITY WILL BE GREATEST. NO PREVAILING SHOWERS OR STORMS ARE IN THE FORECAST FOR ANY OF THE TAF SITES...HOWEVER...THIS MAY NEED AMENDING LATER THIS AFTERNOON BASED ON FUTURE RADAR/SATELLITE DATA. THE GFS IS ONE OF THE FASTER MODEL SOLUTIONS...BRINGING THE FRONT THROUGH THE AREA THIS EVENING...ALMOST CLEARING PRECIP BY 00Z. WENT A LITTLE SLOWER WITH THE TIMING OF PRECIP CONCLUSION AND WIND SHIFT FROM OUT OF THE NNW. HIGHER CONFIDENCE OF MORE IFR TO MVFR CIGS ON THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT...BEFORE CLEARING OUT AN UPPER-DECK BY 14Z TOMORROW. LOW CONFIDENCE ON THE FOG FORMATION TOMORROW MORNING...AS ONCE AGAIN IT WILL BE HIGHLY DEPENDENT ON PRECIP...CLOUDCOVER...AND ARRIVAL OF DRY AIR. INCLUDING BR/FG AT LWB...WITH ONLY BR FORMATION AT BLF/BCB. THIS MAY NEED AMENDING BY THE 00Z/06Z FCST TIME. EXTENDED AVIATION DISCUSSION... THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG WEDNESDAY AND THURSDAY MORNING IN THE BCB/BLF/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS...OVERALL...NOT SEEING MUCH QPF OVER THE NEXT 7-10 DAYS...WHICH SHOULD HELP TO KEEP VFR LEVELS PREVALENT THROUGH THE PERIOD. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...KK LONG TERM...RAB AVIATION...DS/JM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1259 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1255 PM EDT TUESDAY... THERE HAS BEEN A SMALL UPSWING IN THE AMOUNT OF CONVECTION FIRING ACROSS THE REGION. THERE IS NOW A GREATER CONCENTRATION OF SHOWERS ACROSS THE WESTERN PORTION OF THE REGION. MOST OF THE ACTIVITY IS VERY SMALL IN SIZE...AND NO LIGHTNING HAS OCCURRED YET. FAR EASTERN PARTS OF THE AREA REMAIN THE REGION TO WATCH FOR DEEPER CONVECTION ONCE IT BEGINS...GIVEN THIS REGION WAS NOT IMPACTED BY THIS RAIN SHIELD FROM THIS MORNING...AND MOST OF THE DAY HAS HAD AT LEAST SOME SUNSHINE REACHING THE GROUND. AM EXPECTING THE BEST COVERAGE...AND STRONGEST ACTIVITY TO BE IN THIS EASTERN AREA BY THE MID TO LATE AFTERNOON. ONCE WE REACH THIS EVENING...COVERAGE WILL BE CONFINED TO MAINLY THE SOUTHEAST PART OF THE REGION...WITH AN INCREASE IN THE NORTHWEST AS THE COLD FRONT MOVES INTO THE AREA. NO MAJOR CHANGE TO THE FORECAST HIGH TEMPERATURES AS MOST ARE ON TRACK TO BE WITHIN A DEGREE OR TWO OF CURRENTLY FORECAST NUMBERS. AS OF 1010 AM EDT TUESDAY... CONVECTIVE CLUSTER FROM THIS MORNING HAS DISSIPATED INTO A PATCHY AREA OF LIGHT RAIN...AND HAS EXITED THE NORTHEAST PART OF THE FORECAST AREA. HEADING INTO THIS AFTERNOON...MUCH OF THE REGION WILL BE RELATIVELY STABLE...BEING TEMPORARILY CAPPED FROM THE EARLIER CONVECTION AND SLOW TO HEAT AT THE SURFACE TO DO PLENTY OF REMAINING DEBRIS CLOUD COVER. LATER THIS AFTERNOON WITH THE APPROACH AND ARRIVAL OF A COLD FRONT IS WHEN THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD REVAMP ITS COVERAGE. HOWEVER...THE LATEST VERSION OF THE FORECAST WILL BE DOWNPLAYING THE CHANCE OF PRECIPITATION A BIT AS COMPARED TO THE EARLIER NUMBERS THANKS TO THE AFOREMENTIONED NEGATIVE INFLUENCES TO CONVECTION. AS OF 400 AM EDT TUESDAY... A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY CROSS THE BLUE RIDGE. A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT... SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF. WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY MORNING. STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY ADVISORY. AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER 50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE WATER VALUES DROPPING BELOW ONE HALF INCH. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EDT TUESDAY... BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION. DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER 70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE PIEDMONT. AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70 DEGREES IN THE PIEDMONT. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 350 PM EDT MONDAY... THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST. 500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST. CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT. TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 740 AM EDT TUESDAY... CLUSTER OF LIGHT TO MODERATE SHOWERS OVER KLWB WILL BE EAST OF THE AIRPORT BY THE START OF THE 12Z TAF FORECAST PERIOD. IFR TO MVFR CEILINGS IN THE MOUNTAINS WILL BE SLOWER TO IMPROVE BUT MEDIUMCONFIDENCE CONDITIONS WILL BE VFR BY 14Z. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM THIS AFTERNOON ALONG A COLD FRONT. A FEW OF THESE STORMS WILL BECOME STRONG AND MAY PRODUCE GUSTY WINDS. USING THE TIMING OF THE GFS AND BRINING THE FRONT THROUGH THE AREA THIS EVENING WHICH WILL TURN SURFACE TO THE NORTHWEST. HIGH CONFIDENCE OF MORE IFR TO MVFR CLOUDS ON THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT. EXTENDED AVIATION DISCUSSION... THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG WEDNESDAY AND THURSDAY MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...KK LONG TERM...RAB AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1022 AM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1010 AM EDT TUESDAY... CONVECTIVE CLUSTER FROM THIS MORNING HAS DISSIPATED INTO A PATCHY AREA OF LIGHT RAIN...AND HAS EXITED THE NORTHEAST PART OF THE FORECAST AREA. HEADING INTO THIS AFTERNOON...MUCH OF THE REGION WILL BE RELATIVELY STABLE...BEING TEMPORARILY CAPPED FROM THE EARLIER CONVECTION AND SLOW TO HEAT AT THE SURFACE TO DO PLENTY OF REMAINING DEBRIS CLOUD COVER. LATER THIS AFTERNOON WITH THE APPROACH AND ARRIVAL OF A COLD FRONT IS WHEN THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD REVAMP ITS COVERAGE. HOWEVER...THE LATEST VERSION OF THE FORECAST WILL BE DOWNPLAYING THE CHANCE OF PRECIPITATION A BIT AS COMPARED TO THE EARLIER NUMBERS THANKS TO THE AFOREMENTIONED NEGATIVE INFLUENCES TO CONVECTION. AS OF 400 AM EDT TUESDAY... A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY CROSS THE BLUE RIDGE. A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT... SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF. WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY MORNING. STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY ADVISORY. AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER 50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE WATER VALUES DROPPING BELOW ONE HALF INCH. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EDT TUESDAY... BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION. DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER 70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE PIEDMONT. AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70 DEGREES IN THE PIEDMONT. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 350 PM EDT MONDAY... THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST. 500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST. CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT. TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... AS OF 740 AM EDT TUESDAY... CLUSTER OF LIGHT TO MODERATE SHOWERS OVER KLWB WILL BE EAST OF THE AIRPORT BY THE START OF THE 12Z TAF FORECAST PERIOD. IFR TO MVFR CEILINGS IN THE MOUNTAINS WILL BE SLOWER TO IMPROVE BUT MEDIUMCONFIDENCE CONDITIONS WILL BE VFR BY 14Z. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM THIS AFTERNOON ALONG A COLD FRONT. A FEW OF THESE STORMS WILL BECOME STRONG AND MAY PRODUCE GUSTY WINDS. USING THE TIMING OF THE GFS AND BRINING THE FRONT THROUGH THE AREA THIS EVENING WHICH WILL TURN SURFACE TO THE NORTHWEST. HIGH CONFIDENCE OF MORE IFR TO MVFR CLOUDS ON THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT. EXTENDED AVIATION DISCUSSION... THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG WEDNESDAY AND THURSDAY MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...KK LONG TERM...RAB AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
741 AM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT TUESDAY... A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY CROSS THE BLUE RIDGE. A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT... SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF. WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY MORNING. STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY ADVISORY. AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER 50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE WATER VALUES DROPPING BELOW ONE HALF INCH. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EDT TUESDAY... BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION. DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER 70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE PIEDMONT. AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70 DEGREES IN THE PIEDMONT. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 350 PM EDT MONDAY... THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST. 500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST. CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT. TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 740 AM EDT TUESDAY... CLUSTER OF LIGHT TO MODERATE SHOWERS OVER KLWB WILL BE EAST OF THE AIRPORT BY THE START OF THE 12Z TAF FORECAST PERIOD. IFR TO MVFR CEILINGS IN THE MOUNTAINS WILL BE SLOWER TO IMPROVE BUT MEDIUMCONFIDENCE CONDITIONS WILL BE VFR BY 14Z. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM THIS AFTERNOON ALONG A COLD FRONT. A FEW OF THESE STORMS WILL BECOME STRONG AND MAY PRODUCE GUSTY WINDS. USING THE TIMING OF THE GFS AND BRINING THE FRONT THROUGH THE AREA THIS EVENING WHICH WILL TURN SURFACE TO THE NORTHWEST. HIGH CONFIDENCE OF MORE IFR TO MVFR CLOUDS ON THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT. EXTENDED AVIATION DISCUSSION... THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG WEDNESDAY AND THURSDAY MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...RAB AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
433 AM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT TUESDAY... A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY CROSS THE BLUE RIDGE. A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT... SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF. WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY MORNING. STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY ADVISORY. AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER 50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE WATER VALUES DROPPING BELOW ONE HALF INCH. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EDT TUESDAY... BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION. DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER 70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE PIEDMONT. AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70 DEGREES IN THE PIEDMONT. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 350 PM EDT MONDAY... THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST. 500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST. CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT. TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... AS OF 140 AM EDT TUESDAY... 05Z OBSERVATIONS INDICATED IFR STRATUS WAS DEVELOPING ON THE WESTERN SLOPES OF THE APPALACHIANS. HAVE IFR CEILINGS IN AT KBLF AND KLWB UNTIL THE SHOWERS AND THUNDERSTORMS COMING OUT OF WEST VIRGINIA AND KENTUCKY ARRIVE IN THE AREA. TIMING OF THE PRECIPITATION IN THE MODELS HAS BEEN CONSISTENT. EXPECT THE SHOWERS AND THUNDERSTORMS TO REACH KBLF AND KLWB BETWEEN 09Z/5AM AND 11/7AM. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM THIS AFTERNOON OVER THE REGION AHEAD OF A COLD FRONT. A FEW OF THESE STORMS WILL BECOME STRONG AND MAY PRODUCE GUSTY WINDS. THE COLD FRONT WILL PASS ACROSS THE FORECAST AREA THIS EVENING WITH SURFACE WINDS TURNING TO THE NORTHWEST. MEDIUM CONFIDENCE OF MORE MVFR CLOUDS ON THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT. EXTENDED AVIATION DISCUSSION... THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG WEDNESDAY AND THURSDAY MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...RAB AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1043 PM CDT WED JUL 22 2015 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 242 PM CDT WED JUL 22 2015 NORTHWESTERLY FLOW CONTINUES ACROSS THE WESTERN GREAT LAKES AS A SURFACE HIGH PRESSURE RIDGE CONTINUES TO HOLD. CURRENT SURFACE ANALYSIS SHOWS A WEAKNESS IN THE RIDGE ACROSS NORTHERN WISCONSIN WITHIN THE RIDGE...WHICH APPEARS TO BE A WEAK WARM FRONT. RADAR AND VISIBLE SATELLITE TRENDS INDICATE THE HI-RES HRRR RUNS ARE FAIRLY ON POINT IN DEVELOPING SHOWERS ACROSS THIS BOUNDARY THIS AFTERNOON AS A WEAK SHORTWAVE TRACKS THROUGH THE WESTERN GREAT LAKES. THEREFORE WILL PLACE ISOLATED SHOWERS ACROSS THE CENTRAL CWA WITH THIS ACTIVITY...WHICH SHOULD WANE QUICKLY ONCE THE SUN GOES DOWN. DRY CONDITIONS ARE EXPECTED TONIGHT WITH THE LOSS OF DAYTIME HEATING AS THE CUMULUS CLOUDS DISSIPATE QUICKLY. HOWEVER ANOTHER SHORTWAVE WILL BRING SOME MID-LEVEL CLOUDINESS AT TIMES. THE SURFACE RIDGE BEGINS MOVING EAST ON THURSDAY AS WEAK LOW LEVEL WARM AIR ADVECTION CONTINUES. DESPITE MUCH IN THE WAY OF FORCING...THE NWP MODELS ARE STILL ON TRACK TO PRODUCE SOME SHOWERS AND THUNDERSTORMS ACROSS NORTHERN WISCONSIN IN THE VICINITY OF A WEAK WARM FRONT. GIVEN THE CONTINUED MODEL CONSENSUS AMONGST THE MEMBERS AND FROM RUN TO RUN WILL MAINTAIN THE LOW POPS ACROSS THIS AREA FOR THURSDAY. HIGHS ON THURSDAY SHOULD WARM A FEW MORE DEGREES GIVEN CONTINUED WARM AIR ADVECTION...WITH HIGHS GENERALLY IN THE LOWER TO MIDDLE 80S. IN ADDITION TO THE WARMER TEMPERATURES...DEW POINTS RISING TO AROUND 60 DEGREES WILL MAKE CONDITIONS FEEL A BIT MORE HUMID THAN TODAY. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 242 PM CDT WED JUL 22 2015 500 MB ZONAL FLOW WILL CONTINUE INTO EARLY NEXT WEEK...THEN WESTERN RIDGE WILL BUILD BY THE END OF NEXT WEEK. AN ISOLATED SHOWER OR STORM IS POSSIBLE EARLY THURSDAY EVENING. ATTENTION THEN TURNS TO COLD FRONT THAT WILL APPROACH WISCONSIN FRIDAY MORNING. SYSTEM IS A TAD BIT FASTER TODAY THAN YESTERDAY. MODIFIED SOUNDINGS INDICATED 1500 TO 3000 J/KG OF CAPE. WIND SHEAR VALUES OF 30 TO 40 KNOTS NOTED ON THE MODELS DURING THIS PERIOD. MAIN CONCERN IS WARM LAYER ALOFT MAY INHIBIT CONVECTION FROM DEVELOPING UNTIL LATE IN THE DAY DUE TO DAYTIME HEATING AND THE APPROACH OF THE COLD. SOME OF THE STORMS COULD BECOME STRONG OR SEVERE WITH DAMAGING WINDS...LARGE HAIL AND TORRENTIAL RAINFALL. THE GREATEST SEVERE POTENTIALS LOOKS TO BE NORTH AND WEST OF THE FOX VALLEY AT THIS POINT. HOWEVER...STRONG SHEAR ALOFT LEAVES THE POTENTIAL FOR SOME STRONG OR SEVERE STORMS ACROSS NORTHEAST AND EAST-CENTRAL WISCONSIN OVERNIGHT. ANY LINGERING SHOWER OR STORM ACTIVITY SHOULD EXIT THE REGION SATURDAY MORNING WITH DRY CONDITIONS SATURDAY AFTERNOON. THE NEXT CHANCE FOR SHOWERS AND STORMS WILL BE TUESDAY INTO WEDNESDAY MORNING WITH NEXT COLD FRONT MOVING THROUGH THE REGION. IT IS TOO EARLY TO DETERMINE IF ANY OF THESE STORMS WOULD BECOME STRONG OR SEVERE. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1043 PM CDT WED JUL 22 2015 QUIET CONDITIONS FOR THE REST OF THE NIGHT NOW THAT THE SHOWER ACTIVITY HAS DIMINISHED. GENERALLY VFR CONDITIONS ON THURSDAY WITH SW BOUNDARY LAYER WINDS OF 5 TO 10 KTS BY AFTERNOON. A SMALL CHANCE FOR SHOWERS OR PERHAPS A THUNDERSTORM EXISTS IN THE VICINITY OF THE WEAK WARM FRONT ACROSS FAR NORTHERN WISCONSIN THURSDAY AFTERNOON. THE FOX VALLEY AND EAST-CENTRAL AREAS SHOULD REMAIN DRY WITH SCT-BKN MID-LEVEL CLOUDINESS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....KURIMSKI LONG TERM......ECKBERG AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
622 PM CDT WED JUL 22 2015 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 242 PM CDT WED JUL 22 2015 NORTHWESTERLY FLOW CONTINUES ACROSS THE WESTERN GREAT LAKES AS A SURFACE HIGH PRESSURE RIDGE CONTINUES TO HOLD. CURRENT SURFACE ANALYSIS SHOWS A WEAKNESS IN THE RIDGE ACROSS NORTHERN WISCONSIN WITHIN THE RIDGE...WHICH APPEARS TO BE A WEAK WARM FRONT. RADAR AND VISIBLE SATELLITE TRENDS INDICATE THE HI-RES HRRR RUNS ARE FAIRLY ON POINT IN DEVELOPING SHOWERS ACROSS THIS BOUNDARY THIS AFTERNOON AS A WEAK SHORTWAVE TRACKS THROUGH THE WESTERN GREAT LAKES. THEREFORE WILL PLACE ISOLATED SHOWERS ACROSS THE CENTRAL CWA WITH THIS ACTIVITY...WHICH SHOULD WANE QUICKLY ONCE THE SUN GOES DOWN. DRY CONDITIONS ARE EXPECTED TONIGHT WITH THE LOSS OF DAYTIME HEATING AS THE CUMULUS CLOUDS DISSIPATE QUICKLY. HOWEVER ANOTHER SHORTWAVE WILL BRING SOME MID-LEVEL CLOUDINESS AT TIMES. THE SURFACE RIDGE BEGINS MOVING EAST ON THURSDAY AS WEAK LOW LEVEL WARM AIR ADVECTION CONTINUES. DESPITE MUCH IN THE WAY OF FORCING...THE NWP MODELS ARE STILL ON TRACK TO PRODUCE SOME SHOWERS AND THUNDERSTORMS ACROSS NORTHERN WISCONSIN IN THE VICINITY OF A WEAK WARM FRONT. GIVEN THE CONTINUED MODEL CONSENSUS AMONGST THE MEMBERS AND FROM RUN TO RUN WILL MAINTAIN THE LOW POPS ACROSS THIS AREA FOR THURSDAY. HIGHS ON THURSDAY SHOULD WARM A FEW MORE DEGREES GIVEN CONTINUED WARM AIR ADVECTION...WITH HIGHS GENERALLY IN THE LOWER TO MIDDLE 80S. IN ADDITION TO THE WARMER TEMPERATURES...DEW POINTS RISING TO AROUND 60 DEGREES WILL MAKE CONDITIONS FEEL A BIT MORE HUMID THAN TODAY. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 242 PM CDT WED JUL 22 2015 500 MB ZONAL FLOW WILL CONTINUE INTO EARLY NEXT WEEK...THEN WESTERN RIDGE WILL BUILD BY THE END OF NEXT WEEK. AN ISOLATED SHOWER OR STORM IS POSSIBLE EARLY THURSDAY EVENING. ATTENTION THEN TURNS TO COLD FRONT THAT WILL APPROACH WISCONSIN FRIDAY MORNING. SYSTEM IS A TAD BIT FASTER TODAY THAN YESTERDAY. MODIFIED SOUNDINGS INDICATED 1500 TO 3000 J/KG OF CAPE. WIND SHEAR VALUES OF 30 TO 40 KNOTS NOTED ON THE MODELS DURING THIS PERIOD. MAIN CONCERN IS WARM LAYER ALOFT MAY INHIBIT CONVECTION FROM DEVELOPING UNTIL LATE IN THE DAY DUE TO DAYTIME HEATING AND THE APPROACH OF THE COLD. SOME OF THE STORMS COULD BECOME STRONG OR SEVERE WITH DAMAGING WINDS...LARGE HAIL AND TORRENTIAL RAINFALL. THE GREATEST SEVERE POTENTIALS LOOKS TO BE NORTH AND WEST OF THE FOX VALLEY AT THIS POINT. HOWEVER...STRONG SHEAR ALOFT LEAVES THE POTENTIAL FOR SOME STRONG OR SEVERE STORMS ACROSS NORTHEAST AND EAST-CENTRAL WISCONSIN OVERNIGHT. ANY LINGERING SHOWER OR STORM ACTIVITY SHOULD EXIT THE REGION SATURDAY MORNING WITH DRY CONDITIONS SATURDAY AFTERNOON. THE NEXT CHANCE FOR SHOWERS AND STORMS WILL BE TUESDAY INTO WEDNESDAY MORNING WITH NEXT COLD FRONT MOVING THROUGH THE REGION. IT IS TOO EARLY TO DETERMINE IF ANY OF THESE STORMS WOULD BECOME STRONG OR SEVERE. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 622 PM CDT WED JUL 22 2015 SCATTERED SHOWERS ALONG A WEAK WARM FRONT WILL CONTINUE THROUGH ABOUT MID EVENING BEFORE DISSIPATING OVER CENTRAL AND EAST-CENTRAL WI. GENERALLY VFR CONDITIONS ON THURSDAY WITH SW BOUNDARY LAYER WINDS OF 5 TO 10 KTS BY AFTERNOON. A SMALL CHANCE FOR SHOWERS OR PERHAPS A THUNDERSTORM EXISTS IN THE VICINITY OF THE WEAK WARM FRONT ACROSS FAR NORTHERN WISCONSIN THURSDAY AFTERNOON. THE FOX VALLEY AND EAST-CENTRAL AREAS SHOULD REMAIN DRY WITH SCT-BKN MID-LEVEL CLOUDINESS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....KURIMSKI LONG TERM......ECKBERG AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT TUE JUL 21 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 257 PM CDT TUE JUL 21 2015 PRETTY QUIET WEATHER COMING UP OVER THE NEXT COUPLE OF DAYS. THE SURFACE RIDGE...CURRENTLY CENTERED OVER NORTHWEST IOWA AND SOUTHWEST MINNESOTA...WILL DRIFT EAST AND BECOME CENTERED OVER THE GREAT LAKES REGION WEDNESDAY. THIS HIGH WILL THEN ESSENTIALLY REMAIN STATIONARY THROUGH THURSDAY WHICH WILL CONTINUE TO PROVIDE THE REGION WITH DRY CONDITIONS. WITH THE HIGH MOVING OVER THE AREA...THERE IS SOME SMALL POTENTIAL FOR VALLEY FOG TONIGHT. HOWEVER...THE 21.12Z NAM FORECAST SOUNDINGS ARE NOT THAT FAVORABLE FOR FOG FORMATION. IT SUGGESTS IT WILL COME CLOSE TO SATURATION AT THE SURFACE BUT THEN QUICKLY DRY OUT ABOVE THAT AS THE WEST TO NORTHWEST WINDS JUST ABOVE THE SURFACE INCREASE TO AROUND 10 KNOTS. THE 21.17Z RAP IS EVEN LESS ENTHUSED AS IT SHOWS A 3C TEMP/DEW POINT SPREAD AT 11Z. PREVIOUS FORECAST HAD INTRODUCED SOME PATCHY FOG FOR LATE TONIGHT INTO WEDNESDAY MORNING AND WILL MAINTAIN THIS FOR NOW. OTHERWISE...LOOK FOR TEMPERATURES TO SLOWLY WARM WITH HIGHS IN THE LOWER TO MIDDLE 80S EXPECTED BY THURSDAY AND LOWS OF 60 TO 65 BY THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 257 PM CDT TUE JUL 21 2015 THE NEXT CHANCE FOR SOME RAIN WILL COME IN THE FRIDAY TO SATURDAY TIME FRAME. THE MODELS AGREE THAT A SHORT WAVE TROUGH WILL COME OUT OF THE WESTERN CONUS LONG WAVE TROUGH AND MOVE EAST INTO THE RIDGE AXIS. SOME DIFFERENCES BETWEEN THE 21.12Z ECMWF...GFS AND GEM ON HOW MUCH THIS WAVE WILL BE ABLE TO FLATTEN THE RIDGE. THE GFS IS THE MOST AGGRESSIVE WITH THIS SYSTEM WHICH RESULTS IN THE FLATTEST RIDGE AND THE STRONGEST WAVE COMING ACROSS THE REGION. THE WAVE THE GFS BRINGS THROUGH HAS THE LOOK OF POSSIBLY BEING FROM CONVECTIVE FEEDBACK. THE GEM IS THE WEAKEST WITH THE SYSTEM AND KEEPS MORE RIDGING OVER THE AREA WHILE THE ECMWF IS IN BETWEEN THESE TWO SOLUTIONS BUT LOOKS MORE LIKE THE GEM THAN THE GFS. THE ECMWF HAS STARTED TO BACK OFF FROM THE 21.00Z RUN ON THE AMOUNT AND COVERAGE OF RAIN FOR FRIDAY NIGHT WITH THIS SYSTEM AS THE COLD FRONT COMES THROUGH. BASED ON THIS TREND...CAPPED THE MODEL CONSENSUS GRIDS AT A 60 PERCENT CHANCE OF RAIN...WHICH MAINTAINS PRETTY GOOD CONTINUITY WITH THE PREVIOUS FORECAST. IF THE GFS IS CORRECT...THERE COULD BE SOME SEVERE POTENTIAL WITH THIS SYSTEM AS IT SHOWS AROUND 2000 J/KG OF ML CAPE FRIDAY EVENING DROPPING TO AROUND 1000 J/KG OVERNIGHT. THE 0-6KM SHEAR LOOKS PRETTY WEAK IN THE EVENING BUT COULD INCREASE TO 35 TO 40 KNOTS OVERNIGHT. AFTER THIS SYSTEM...ANOTHER QUICK MOVING SHORT WAVE TROUGH COULD COME ACROSS SATURDAY NIGHT WITH SOME ADDITIONAL RAIN AND THEN THE NEXT SHORT WAVE TROUGH TO POTENTIALLY COME THROUGH RIDGE COULD BE MONDAY NIGHT INTO TUESDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 600 PM CDT TUE JUL 21 2015 A SFC HIGH WILL BE THE MAIN WEATHER FEATURE FOR THE REGION INTO THU...ALTHOUGH A FEW MID/LEVEL CLOUDS COULD SPILL ACROSS THE UPPER LEVEL RIDGE ON WED. VFR CONDITIONS SHOULD PREVAIL. THAT SAID...WITH THE HIGH OVERHEAD AND A LIGHT SFC WIND VALLEY FOG HAS TO BE CONSIDERED. KLSE BUFKIT RAP/HRRR SOUNDINGS SUGGEST A DEEP LIGHT WIND FIELD IN EXCESS OF 8 KFT...BUT KEEP A HEALTHY T/TD SPREAD. NAM12 SIMILAR BUT BRINGS SFC T/TD TOGETHER BY 12Z. EXPECT SOME RIVER VALLEY FOG...BUT HOW WIDESPREAD IN THE MISSISSIPPI IS IN QUESTION. 23Z KLSE OB HAS A +27 T/TD SPREAD WITH 9 KTS OF WIND...BOTH NOT FAVORABLE FOR FG AT KLSE...BUT NOT NECESSARILY PRECLUDING THE POTENTIAL COMPLETELY EITHER. GOING TO STICK WITH BCFG FOR NOW. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
257 PM CDT TUE JUL 21 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 257 PM CDT TUE JUL 21 2015 PRETTY QUIET WEATHER COMING UP OVER THE NEXT COUPLE OF DAYS. THE SURFACE RIDGE...CURRENTLY CENTERED OVER NORTHWEST IOWA AND SOUTHWEST MINNESOTA...WILL DRIFT EAST AND BECOME CENTERED OVER THE GREAT LAKES REGION WEDNESDAY. THIS HIGH WILL THEN ESSENTIALLY REMAIN STATIONARY THROUGH THURSDAY WHICH WILL CONTINUE TO PROVIDE THE REGION WITH DRY CONDITIONS. WITH THE HIGH MOVING OVER THE AREA...THERE IS SOME SMALL POTENTIAL FOR VALLEY FOG TONIGHT. HOWEVER...THE 21.12Z NAM FORECAST SOUNDINGS ARE NOT THAT FAVORABLE FOR FOG FORMATION. IT SUGGESTS IT WILL COME CLOSE TO SATURATION AT THE SURFACE BUT THEN QUICKLY DRY OUT ABOVE THAT AS THE WEST TO NORTHWEST WINDS JUST ABOVE THE SURFACE INCREASE TO AROUND 10 KNOTS. THE 21.17Z RAP IS EVEN LESS ENTHUSED AS IT SHOWS A 3C TEMP/DEW POINT SPREAD AT 11Z. PREVIOUS FORECAST HAD INTRODUCED SOME PATCHY FOG FOR LATE TONIGHT INTO WEDNESDAY MORNING AND WILL MAINTAIN THIS FOR NOW. OTHERWISE...LOOK FOR TEMPERATURES TO SLOWLY WARM WITH HIGHS IN THE LOWER TO MIDDLE 80S EXPECTED BY THURSDAY AND LOWS OF 60 TO 65 BY THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 257 PM CDT TUE JUL 21 2015 THE NEXT CHANCE FOR SOME RAIN WILL COME IN THE FRIDAY TO SATURDAY TIME FRAME. THE MODELS AGREE THAT A SHORT WAVE TROUGH WILL COME OUT OF THE WESTERN CONUS LONG WAVE TROUGH AND MOVE EAST INTO THE RIDGE AXIS. SOME DIFFERENCES BETWEEN THE 21.12Z ECMWF...GFS AND GEM ON HOW MUCH THIS WAVE WILL BE ABLE TO FLATTEN THE RIDGE. THE GFS IS THE MOST AGGRESSIVE WITH THIS SYSTEM WHICH RESULTS IN THE FLATTEST RIDGE AND THE STRONGEST WAVE COMING ACROSS THE REGION. THE WAVE THE GFS BRINGS THROUGH HAS THE LOOK OF POSSIBLY BEING FROM CONVECTIVE FEEDBACK. THE GEM IS THE WEAKEST WITH THE SYSTEM AND KEEPS MORE RIDGING OVER THE AREA WHILE THE ECMWF IS IN BETWEEN THESE TWO SOLUTIONS BUT LOOKS MORE LIKE THE GEM THAN THE GFS. THE ECMWF HAS STARTED TO BACK OFF FROM THE 21.00Z RUN ON THE AMOUNT AND COVERAGE OF RAIN FOR FRIDAY NIGHT WITH THIS SYSTEM AS THE COLD FRONT COMES THROUGH. BASED ON THIS TREND...CAPPED THE MODEL CONSENSUS GRIDS AT A 60 PERCENT CHANCE OF RAIN...WHICH MAINTAINS PRETTY GOOD CONTINUITY WITH THE PREVIOUS FORECAST. IF THE GFS IS CORRECT...THERE COULD BE SOME SEVERE POTENTIAL WITH THIS SYSTEM AS IT SHOWS AROUND 2000 J/KG OF ML CAPE FRIDAY EVENING DROPPING TO AROUND 1000 J/KG OVERNIGHT. THE 0-6KM SHEAR LOOKS PRETTY WEAK IN THE EVENING BUT COULD INCREASE TO 35 TO 40 KNOTS OVERNIGHT. AFTER THIS SYSTEM...ANOTHER QUICK MOVING SHORT WAVE TROUGH COULD COME ACROSS SATURDAY NIGHT WITH SOME ADDITIONAL RAIN AND THEN THE NEXT SHORT WAVE TROUGH TO POTENTIALLY COME THROUGH RIDGE COULD BE MONDAY NIGHT INTO TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 116 PM CDT TUE JUL 21 2015 VFR CONDITIONS EXPECTED THROUGH WEDNESDAY MORNING AS HIGH PRESSURE DOMINATES THE UPPER MISSISSIPPI RIVER VALLEY REGION. THERE WILL LIKELY BE SOME RIVER VALLEY FOG...BUT CONFIDENCE IS RELATIVELY LOW FOR FOG AT KLSE. INCLUDED BCFG/FEW003 FOR NOW IN THE 09-14Z TIME FRAME. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1125 PM CDT MON JUL 20 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 248 PM CDT MON JUL 20 2015 CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP TROUGH PLOWING INTO BRITISH COLUMBIA... RIDGING OVER THE NORTHERN U.S. ROCKIES INTO ALBERTA / SASKATCHEWAN...AND TROUGHING FROM NORTHERN ONTARIO INTO NORTHERN MN. A SHORTWAVE WAS ALSO EVIDENT OVER EASTERN IOWA...WHICH COMBINED WITH A SURGE OF 850MB MOISTURE TRANSPORT...MID LEVEL FRONTOGENESIS AND PRECIPITABLE WATER AROUND 1.5 INCHES HELPED BRING SHOWERS AND SOME THUNDERSTORMS TO THE SOUTHEAST HALF OF THE FORECAST AREA THIS MORNING. A SURFACE COLD FRONT WAS ALSO MARCHING THROUGH THE FORECAST AREA...NOW FROM GREEN BAY TO OELWEIN. INSTABILITY HAS BEEN BEEN LIMITED DUE TO MORNING CLOUDS/SHOWERS... BUT RAP MESOANALYSIS SUGGESTS UP TO 1000 J/KG OF MLCAPE EXISTS ALONG THE FRONT. THIS INSTABILITY HAS RESULTED IN SOME ISOLATED SHOWERS ALONG THE FRONT...WITH WEAK LOW LEVEL CONVERGENCE PREVENTING MORE DEVELOPMENT. IN THE WAKE OF THE FRONT... PRECIPITABLE WATER DROPS DOWN TO 0.75 INCHES...RESULTING IN DRYING OF THE AIR INCLUDING AT THE SURFACE. HOWEVER...A FEW SHOWERS WERE NOTED IN THE COLD POOL REGION UNDERNEATH THE TROUGH IN FAR NORTHERN MN/ONTARIO. BREEZY CONDITIONS NOTED TOO BEHIND THE FRONT WITH TIGHTER PRESSURE GRADIENT AND DAYTIME MIXING. THESE NORTHWEST WINDS WERE DRIVING IN COLDER AIR...NOTED BY 850MB TEMPS OF 16-18C AHEAD COMPARED TO 8-10C OVER NORTHERN MN. SURFACE RIDGE RESIDED WELL TO THE WEST OVER THE WESTERN DAKOTAS. ANY SHOWERS/STORMS THE DEVELOP ALONG THE COLD FRONT OVER THE SOUTHEAST THIRD OF THE FORECAST AREA SHOULD EXIT BY 23/00Z AS THE FRONT CONTINUES TO PUSH SOUTHEAST. AFTER THAT...COOLER...DRIER AIR REMAINS ON TRACK TO DROP INTO THE REGION FOR TONIGHT AND MONDAY. THE EXTENSION OF THE UPPER TROUGH IN NORTHERN MN LOOKS TO SWING ACROSS ALL OF WI TONIGHT AND INTO THE EASTERN GREAT LAKES ON TUESDAY. THIS UPPER TROUGH WILL HELP DRIVE 850MB TEMPS DOWN TO 10-11C BY 12Z TUE. ANY OF THE SHOWERS ACCOMPANYING THE COLD POOL LOOK TO STAY WELL NORTH AND DIMINISH WITH LOSS OF DAYTIME HEATING THIS EVENING. SKIES WILL CLEAR OUT QUICKLY THIS EVENING AS DRY AIR INFILTRATES AND LOSS OF DAYTIME HEATING DISSIPATES CUMULUS. IF NOT FOR A PERSISTENT NORTHWEST BREEZE WE COULD SEE A DECENT VALLEY FOG EVENT. NEVERTHELESS...THE MORE SHELTERED SMALLER VALLEYS LIKE THE WISCONSIN WILL FOG. THE TYPICAL COLD SPOTS SHOULD ALSO RADIATE NICELY AND DIP DOWN INTO THE UPPER 40S. THE REST OF THE REGION SHOULD SEE LOWS IN THE 50S. PLENTY OF SUN ON TRACK FOR TUESDAY WITH DRY AIR IN PLACE AND HIGH PRESSURE BUILDING IN. WITH 850MB TEMPS CLIMBING TO 12-14C BY 00Z WEDNESDAY THANKS TO DEEP MIXING...HIGHS IN THE 70S SHOULD BE COMMON WITH LOW 80S FOUND IN RIVER VALLEYS AND SANDY SOIL AREAS. THE DEEP MIXING ALSO SHOULD PROMOTE IN QUITE A BIT LOWER DEWPOINTS COMPARED TO TODAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 248 PM CDT MON JUL 20 2015 UPPER RIDGING SEEN OVER THE NORTHERN ROCKIES AND SASKATCHEWAN / ALBERTA IS PROGGED TO GRADUALLY MOVE EAST INTO THE REGION OVER THE NEXT FEW DAYS...MOVING OVERHEAD AROUND 12Z FRIDAY. SUBSIDENCE WITH THIS UPPER RIDGING BUILDING IN...COMBINED WITH THE FRONT TODAY PUSHING ALL THE MOISTURE SOUTH OF I-70 RESULT IN DRY CONDITIONS FOR THE MOST PART THROUGH THURSDAY NIGHT. HOWEVER...THERE IS A BAND OF MID LEVEL FRONTOGENESIS THAT LOOKS TO SET UP LATE WEDNESDAY INTO THURSDAY...SITUATED FROM CENTRAL MN INTO NORTH CENTRAL WI. THE 20.12Z NAM/ECMWF/CANADIAN HAVE BACKED OFF ON THE INTENSITY AND THUS QPF PRODUCTION TO THE POINT OF NEARLY DRY. ON THE OTHER HAND THE 20.12Z GFS STILL PRODUCES SOME QPF. BELIEVE THE GFS MIGHT BE OVERLY MOIST...A KNOWN BIAS...AND THEREFORE HAVE TRENDED DRY FOR TAYLOR/CLARK COUNTIES DURING MID- WEEK. TEMPERATURES WEDNESDAY AND THURSDAY WILL BE ON A WARMING TREND AS 850MB TEMPS EVENTUALLY CLIMB TO 14-16C BY 00Z FRI. MAY HAVE TO CONTEND WITH VALLEY FOG TUESDAY NIGHT WITH LIGHT WINDS...BUT THERE ARE HINTS OF SOME CLOUDS PASSING THROUGH. THEREFORE...HAVE KEPT MUCH FOG OUT. FOR FRIDAY THROUGH MONDAY...THE MAIN FEATURE OF INTEREST IS A PORTION OF THE DEEP TROUGH IN BRITISH COLUMBIA THAT DROPS THROUGH THE REGION LATE FRIDAY THROUGH SATURDAY EVENING. 20.12Z GFS/ECMWF/CANADIAN ALL WANT TO DEVELOP CONVECTION IN WARM ADVECTION AHEAD OF THE SHORTWAVE TROUGH...THEN ADDITIONAL CONVECTION AS THE COLD FRONT ASSOCIATED WITH THE TROUGH COMES THROUGH. SOME TIMING ISSUES THUS PRECIPITATION CHANCES ARE SPREAD OUT...THOUGH IF TRENDS CONTINUE SHOULD BE ABLE TO PULL OUT CHANCES FOR SATURDAY NIGHT AND EVEN SATURDAY AFTERNOON. IF THE GFS PANS OUT WE MIGHT HAVE TO DEAL WITH SOME SEVERE STORMS...PARTICULARLY FRIDAY NIGHT...BUT THE ECMWF WOULD KEEP ITS SEVERE THREAT FARTHER TO THE SOUTHWEST. SOMETHING TO WATCH. DRIER WEATHER THEN FOLLOWS FOR SUNDAY AS UPPER AND SURFACE RIDGING BEGINS BUILDING BACK IN. PERHAPS ANOTHER INTERESTING PERIOD COULD SETUP SUNDAY NIGHT AND MONDAY...PARTICULARLY IN THE ECMWF...AS A SHORTWAVE COMES DOWN THE RIDGE BUILDING IN. FOR NOW JUST HAVE SOME LOW CHANCES ON MONDAY PER CONSENSUS BUT THESE MAY NEED ADJUSTMENT. OVERALL TEMPERATURES LOOK TO STAY AT OR ABOVE SEASONABLE NORMALS...AND SOME OF THE HIGHS IN THE CURRENT FORECAST ALTHOUGH NEAR CONSENSUS COULD END UP BEING A LITTLE HIGHER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1125 PM CDT MON JUL 20 2015 A PERIOD OF GOOD VFR CONDITIONS EXPECTED THE REST OF TONIGHT THRU TUE EVENING AS DRIER AND COOLER CANADIAN HIGH PRESSURE SETTLES INTO THE UPPER MIDWEST. NORTHWEST WINDS OF 5 TO 8 KTS WILL CONTINUE THRU TONIGHT...LIMITING ANY LATE NIGHT/EARLY MORNING BR POTENTIAL AT SITES LIKE KLSE. A FEW/SCT 5K-6K FT DIURNAL CUMULUS EXPECTED WITH DIURNAL WARMING/MIXING LATE TUE MORNING THRU TUE AFTERNOON...ALONG WITH SOME INCREASE OF THE NORTHWEST WINDS WITH DEEPER DIURNAL MIXING. THE SFC RIDGE AXIS WILL APPROACH/PASS TUE EVENING WITH WINDS BECOMING LIGHT/VARIABLE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
921 PM MDT WED JUL 22 2015 .UPDATE... ISSUED AT 906 PM MDT WED JUL 22 2015 THUNDERSTORM ACTIVITY HAS DECREASED SUBSTANTIALLY OVER THE LAST FEW HOURS. WILL SEE ISOLATED SHOWER ACTIVITY CONTINUE THIS EVENING BUT BY MIDNIGHT MOST ALL SHOWERS SHOULD HAVE DISSIPATED. COULD SEE A FEW SHOWERS LINGER INTO THE NW PORTIONS OF THE FORECAST AREA BUT NOT EXPECTING MORE THAN A FEW SPRINKLES. UPDATE ISSUED AT 442 PM MDT WED JUL 22 2015 UPDATED THUNDERSTORM CHANCES TO INCLUDE THE NORTHERN NEBRASKA PANHANDLE AND ALL OF EAST CENTRAL WYOMING FOR EARLY THIS EVENING. CURRENTLY A LINE OF THUNDERSTORMS IS MAKING ITS INTO THAT AREA AND WITH A VERY UNSTABLE AIRMASS AND INCREASING SURFACE BASED CAPE VALUES...STORMS SHOULD CONTINUE TO PROPAGATE ACROSS THAT AREA OVER THE NEXT SEVERAL HOURS. WITH LIMITED SHEAR SEVERE THUNDERSTORM THREAT IS ON THE LOW SIDE BUT HIGHER CAPE VALUES DO SUPPORT SOME STRONGER PULSE THUNDERSTORMS. MARGINAL SEVERE HAIL...HEAVY RAIN AND WIND GUSTS TO 60 MPH CAN NOT BE RULED OUT OVER THROUGH EARLY EVENING. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 230 PM MDT WED JUL 22 2015 LATEST WATER VAPOR DEPICTING LAST OF MONSOONAL MOISTURE ACROSS SOUTHEAST WYOMING THIS AFTERNOON. SIGNIFICANT DRYING ON WATER VAPOR OVER MOST OF COLORADO IS INCHING EVER SO SLOWLY NORTHWARD TOWARDS THE SOUTHERN WYOMING BORDER. SEEING SCATTERED SHOWERS AND THUNDERSTORMS ON AREA RADAR THIS AFTERNOON...MAINLY ALONG THE WYOMING/COLORADO BORDER AND MOUNTAIN RANGES TO OUR WEST AND NORTH. SURFACE BASED CAPE OFF THE MESOANALYST PAGE SHOWING RIGHT AROUND 500 J/KG WHERE THESE THUNDERSTORMS ARE FORMING...SO DO NOT EXPECT ANY SEVERE TSTMS FROM THESE. BETTER INSTABILITY ACROSS THE PANHANDLE WHERE CAPES ARE RUNNING 1500-2500 J/KG AT 1 PM THIS AFTERNOON. DEWPOINTS ACROSS THE PANHANDLE NEAR 60 FOR ALLIANCE...SCOTTSBLUFF AND SIDNEY. WILL NEED TO WATCH THUNDERSTORM EVOLUTION AS THE AFTERNOON PROGRESSES OUT THAT WAY. LATEST HRRR FORECAST RADAR SHOWING THE POSSIBILITY OF A FEW STRONG STORMS MAKING IT INTO THIS MORE UNSTABLE AIR IN THE PANHANDLE THIS AFTERNOON AROUND 00Z. CAN NOT RULE OUT ONE OR TWO SEVERE STORMS FOR THIS EVENING OUT THAT WAY. SHEAR OUT THAT WAY ALMOST NONEXISTENT...WITH LONG SKINNY CAPE PROFILES...SO THINK THE MORE PROMINENT HAZARD WOULD BE HEAVY RAIN. ATTENTION TURNS TO ELEVATED FIRE CONDITIONS THURSDAY AND FRIDAY. GFS FORECASTING THE LOW PRESSURE SYSTEM CURRENTLY OVER SOUTHERN BRITISH COLUMBIA...TO TRACK INTO NORTHERN MONTANA THURSDAY. THIS IS A FAVORABLE WIND PATTERN FOR SOUTHEAST WYOMING. AS A RESULT...WESTERLY WINDS BEGIN TO INCREASE OUT ACROSS CARBON AND ALBANY COUNTIES. GFS 700MB WINDS OF 30-35KTS THURSDAY AFTERNOON. LOOKS LIKE THE AREA WILL MIX UP TO AT LEAST 580MBS OUT THAT WAY. NAM WINDS UP AROUND THAT LEVEL FORECAST AT 35-40KTS...SO CARBON AND ALBANY COUNTIES COULD BE SEEING WINDS GUSTING TO 40MPH OR MORE. FORTUNATELY...FUELS ARE STILL BEING REPORTED AS NOT READY FOR MOST FIRE ZONES...SO RED FLAG WARNINGS ARE NOT EXPECTED. WINDS EASE SOME FRIDAY AS THE LOW TRACKS EAST INTO SOUTHERN ALBERTA CANADA AND EASTWARD. LESS CLOUD COVERAGE AND 700MB TEMPERATURES CLIMBING TO +16C FRIDAY AND SATURDAY SHOULD LEAD TO SOME VERY WARM TEMPERATURES. DID GO OVER GUIDANCE ON HIGHS FOR THURSDAY AND FRIDAY. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 230 PM MDT WED JUL 22 2015 UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS/HIGH PLAINS WILL MEANDER OVER THAT GENERAL AREA THROUGH THIS PERIOD. THE CWA WILL RESIDE ON THE NORTHERN PERIPHERY OF THE HIGH WITH WARM AND MAINLY DRY WEATHER EXPECTED OVERALL...WITH THE WARMEST DAYS SATURDAY THROUGH MONDAY. A COUPLE DISTURBANCES SHOULD ROTATE OVER THE HIGH AND MAY BRING SOME CONVECTION TO PARTS OF THE CWA...MAINLY SUNDAY AND WEDNESDAY. MONSOONAL MOISTURE LOOKS LIKE IT WILL REMAIN CUT OFF FOR THE MOST PART. AN UPPER LOW WILL MOVE EAST ACROSS THE SOUTHERN CANADIAN PRAIRIES MONDAY THROUGH TUESDAY AND SHOULD DRIVE A COOL FRONT ACROSS THE CWA MONDAY NIGHT WITH TEMPS LOWERING CLOSER TO SEASONAL AVERAGES FOR TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 919 PM MDT WED JUL 22 2015 VFR. SCATTERED TO BROKEN CLOUDS AT OR ABOVE 4500 FEET AGL. && .FIRE WEATHER... ISSUED AT 230 PM MDT WED JUL 22 2015 A DRIER AND MORE WINDY PERIOD AHEAD FOR THE REMAINDER OF THE WEEK AFTER SHOWERS AND THUNDERSTORMS END TODAY. MONSOONAL MOISTURE FORECAST TO BE SUPPRESSED SOUTH AND EAST BY THURSDAY. LOW PRESSURE TRACKING THROUGH NORTHERN MONTANA THURSDAY WILL AID IN INCREASING WESTERLY TO SOUTHWESTERLY WINDS...ESPECIALLY WEST OF THE LARAMIE RANGE THURSDAY AND FRIDAY. ELEVATED FIRE WEATHER CONCERNS WITH THESE WINDS AND AFTERNOON HUMIDITIES FALLING TO 15 PERCENT BOTH AFTERNOONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...SML SHORT TERM...GCC LONG TERM...RE AVIATION...RUBIN FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
911 PM MDT WED JUL 22 2015 .UPDATE... ISSUED AT 906 PM MDT WED JUL 22 2015 THUNDERSTORM ACTIVITY HAS DECREASED SUBSTANTIALLY OVER THE LAST FEW HOURS. WILL SEE ISOLATED SHOWER ACTIVITY CONTINUE THIS EVENING BUT BY MIDNIGHT MOST ALL SHOWERS SHOULD HAVE DISSIPATED. COULD SEE A FEW SHOWERS LINGER INTO THE NW PORTIONS OF THE FORECAST AREA BUT NOT EXPECTING MORE THAN A FEW SPRINKLES. UPDATE ISSUED AT 442 PM MDT WED JUL 22 2015 UPDATED THUNDERSTORM CHANCES TO INCLUDE THE NORTHERN NEBRASKA PANHANDLE AND ALL OF EAST CENTRAL WYOMING FOR EARLY THIS EVENING. CURRENTLY A LINE OF THUNDERSTORMS IS MAKING ITS INTO THAT AREA AND WITH A VERY UNSTABLE AIRMASS AND INCREASING SURFACE BASED CAPE VALUES...STORMS SHOULD CONTINUE TO PROPAGATE ACROSS THAT AREA OVER THE NEXT SEVERAL HOURS. WITH LIMITED SHEAR SEVERE THUNDERSTORM THREAT IS ON THE LOW SIDE BUT HIGHER CAPE VALUES DO SUPPORT SOME STRONGER PULSE THUNDERSTORMS. MARGINAL SEVERE HAIL...HEAVY RAIN AND WIND GUSTS TO 60 MPH CAN NOT BE RULED OUT OVER THROUGH EARLY EVENING. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 230 PM MDT WED JUL 22 2015 LATEST WATER VAPOR DEPICTING LAST OF MONSOONAL MOISTURE ACROSS SOUTHEAST WYOMING THIS AFTERNOON. SIGNIFICANT DRYING ON WATER VAPOR OVER MOST OF COLORADO IS INCHING EVER SO SLOWLY NORTHWARD TOWARDS THE SOUTHERN WYOMING BORDER. SEEING SCATTERED SHOWERS AND THUNDERSTORMS ON AREA RADAR THIS AFTERNOON...MAINLY ALONG THE WYOMING/COLORADO BORDER AND MOUNTAIN RANGES TO OUR WEST AND NORTH. SURFACE BASED CAPE OFF THE MESOANALYST PAGE SHOWING RIGHT AROUND 500 J/KG WHERE THESE THUNDERSTORMS ARE FORMING...SO DO NOT EXPECT ANY SEVERE TSTMS FROM THESE. BETTER INSTABILITY ACROSS THE PANHANDLE WHERE CAPES ARE RUNNING 1500-2500 J/KG AT 1 PM THIS AFTERNOON. DEWPOINTS ACROSS THE PANHANDLE NEAR 60 FOR ALLIANCE...SCOTTSBLUFF AND SIDNEY. WILL NEED TO WATCH THUNDERSTORM EVOLUTION AS THE AFTERNOON PROGRESSES OUT THAT WAY. LATEST HRRR FORECAST RADAR SHOWING THE POSSIBILITY OF A FEW STRONG STORMS MAKING IT INTO THIS MORE UNSTABLE AIR IN THE PANHANDLE THIS AFTERNOON AROUND 00Z. CAN NOT RULE OUT ONE OR TWO SEVERE STORMS FOR THIS EVENING OUT THAT WAY. SHEAR OUT THAT WAY ALMOST NONEXISTENT...WITH LONG SKINNY CAPE PROFILES...SO THINK THE MORE PROMINENT HAZARD WOULD BE HEAVY RAIN. ATTENTION TURNS TO ELEVATED FIRE CONDITIONS THURSDAY AND FRIDAY. GFS FORECASTING THE LOW PRESSURE SYSTEM CURRENTLY OVER SOUTHERN BRITISH COLUMBIA...TO TRACK INTO NORTHERN MONTANA THURSDAY. THIS IS A FAVORABLE WIND PATTERN FOR SOUTHEAST WYOMING. AS A RESULT...WESTERLY WINDS BEGIN TO INCREASE OUT ACROSS CARBON AND ALBANY COUNTIES. GFS 700MB WINDS OF 30-35KTS THURSDAY AFTERNOON. LOOKS LIKE THE AREA WILL MIX UP TO AT LEAST 580MBS OUT THAT WAY. NAM WINDS UP AROUND THAT LEVEL FORECAST AT 35-40KTS...SO CARBON AND ALBANY COUNTIES COULD BE SEEING WINDS GUSTING TO 40MPH OR MORE. FORTUNATELY...FUELS ARE STILL BEING REPORTED AS NOT READY FOR MOST FIRE ZONES...SO RED FLAG WARNINGS ARE NOT EXPECTED. WINDS EASE SOME FRIDAY AS THE LOW TRACKS EAST INTO SOUTHERN ALBERTA CANADA AND EASTWARD. LESS CLOUD COVERAGE AND 700MB TEMPERATURES CLIMBING TO +16C FRIDAY AND SATURDAY SHOULD LEAD TO SOME VERY WARM TEMPERATURES. DID GO OVER GUIDANCE ON HIGHS FOR THURSDAY AND FRIDAY. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 230 PM MDT WED JUL 22 2015 UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS/HIGH PLAINS WILL MEANDER OVER THAT GENERAL AREA THROUGH THIS PERIOD. THE CWA WILL RESIDE ON THE NORTHERN PERIPHERY OF THE HIGH WITH WARM AND MAINLY DRY WEATHER EXPECTED OVERALL...WITH THE WARMEST DAYS SATURDAY THROUGH MONDAY. A COUPLE DISTURBANCES SHOULD ROTATE OVER THE HIGH AND MAY BRING SOME CONVECTION TO PARTS OF THE CWA...MAINLY SUNDAY AND WEDNESDAY. MONSOONAL MOISTURE LOOKS LIKE IT WILL REMAIN CUT OFF FOR THE MOST PART. AN UPPER LOW WILL MOVE EAST ACROSS THE SOUTHERN CANADIAN PRAIRIES MONDAY THROUGH TUESDAY AND SHOULD DRIVE A COOL FRONT ACROSS THE CWA MONDAY NIGHT WITH TEMPS LOWERING CLOSER TO SEASONAL AVERAGES FOR TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 608 PM MDT WED JUL 22 2015 ISOLATED THUNDERSTORMS PRODUCING WIND GUSTS TO 35 KNOTS THROUGH 02Z...THEN DECREASING CLOUDS. VFR...WITH LOCALIZED MVFR NEAR THUNDERSTORMS. LATE THURSDAY MORNING AND AFTERNOON...WEST WIND GUSTING 25 TO 35 KNOTS. && .FIRE WEATHER... ISSUED AT 230 PM MDT WED JUL 22 2015 A DRIER AND MORE WINDY PERIOD AHEAD FOR THE REMAINDER OF THE WEEK AFTER SHOWERS AND THUNDERSTORMS END TODAY. MONSOONAL MOISTURE FORECAST TO BE SUPPRESSED SOUTH AND EAST BY THURSDAY. LOW PRESSURE TRACKING THROUGH NORTHERN MONTANA THURSDAY WILL AID IN INCREASING WESTERLY TO SOUTHWESTERLY WINDS...ESPECIALLY WEST OF THE LARAMIE RANGE THURSDAY AND FRIDAY. ELEVATED FIRE WEATHER CONCERNS WITH THESE WINDS AND AFTERNOON HUMIDITIES FALLING TO 15 PERCENT BOTH AFTERNOONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...SML SHORT TERM...GCC LONG TERM...RE AVIATION...RUBIN FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
611 PM MDT WED JUL 22 2015 .UPDATE... ISSUED AT 442 PM MDT WED JUL 22 2015 UPDATED THUNDERSTORM CHANCES TO INCLUDE THE NORTHERN NEBRASKA PANHANDLE AND ALL OF EAST CENTRAL WYOMING FOR EARLY THIS EVENING. CURRENTLY A LINE OF THUNDERSTORMS IS MAKING ITS INTO THAT AREA AND WITH A VERY UNSTABLE AIRMASS AND INCREASING SURFACE BASED CAPE VALUES...STORMS SHOULD CONTINUE TO PROPAGATE ACROSS THAT AREA OVER THE NEXT SEVERAL HOURS. WITH LIMITED SHEAR SEVERE THUNDERSTORM THREAT IS ON THE LOW SIDE BUT HIGHER CAPE VALUES DO SUPPORT SOME STRONGER PULSE THUNDERSTORMS. MARGINAL SEVERE HAIL...HEAVY RAIN AND WIND GUSTS TO 60 MPH CAN NOT BE RULED OUT OVER THROUGH EARLY EVENING. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 230 PM MDT WED JUL 22 2015 LATEST WATER VAPOR DEPICTING LAST OF MONSOONAL MOISTURE ACROSS SOUTHEAST WYOMING THIS AFTERNOON. SIGNIFICANT DRYING ON WATER VAPOR OVER MOST OF COLORADO IS INCHING EVER SO SLOWLY NORTHWARD TOWARDS THE SOUTHERN WYOMING BORDER. SEEING SCATTERED SHOWERS AND THUNDERSTORMS ON AREA RADAR THIS AFTERNOON...MAINLY ALONG THE WYOMING/COLORADO BORDER AND MOUNTAIN RANGES TO OUR WEST AND NORTH. SURFACE BASED CAPE OFF THE MESOANALYST PAGE SHOWING RIGHT AROUND 500 J/KG WHERE THESE THUNDERSTORMS ARE FORMING...SO DO NOT EXPECT ANY SEVERE TSTMS FROM THESE. BETTER INSTABILITY ACROSS THE PANHANDLE WHERE CAPES ARE RUNNING 1500-2500 J/KG AT 1 PM THIS AFTERNOON. DEWPOINTS ACROSS THE PANHANDLE NEAR 60 FOR ALLIANCE...SCOTTSBLUFF AND SIDNEY. WILL NEED TO WATCH THUNDERSTORM EVOLUTION AS THE AFTERNOON PROGRESSES OUT THAT WAY. LATEST HRRR FORECAST RADAR SHOWING THE POSSIBILITY OF A FEW STRONG STORMS MAKING IT INTO THIS MORE UNSTABLE AIR IN THE PANHANDLE THIS AFTERNOON AROUND 00Z. CAN NOT RULE OUT ONE OR TWO SEVERE STORMS FOR THIS EVENING OUT THAT WAY. SHEAR OUT THAT WAY ALMOST NONEXISTENT...WITH LONG SKINNY CAPE PROFILES...SO THINK THE MORE PROMINENT HAZARD WOULD BE HEAVY RAIN. ATTENTION TURNS TO ELEVATED FIRE CONDITIONS THURSDAY AND FRIDAY. GFS FORECASTING THE LOW PRESSURE SYSTEM CURRENTLY OVER SOUTHERN BRITISH COLUMBIA...TO TRACK INTO NORTHERN MONTANA THURSDAY. THIS IS A FAVORABLE WIND PATTERN FOR SOUTHEAST WYOMING. AS A RESULT...WESTERLY WINDS BEGIN TO INCREASE OUT ACROSS CARBON AND ALBANY COUNTIES. GFS 700MB WINDS OF 30-35KTS THURSDAY AFTERNOON. LOOKS LIKE THE AREA WILL MIX UP TO AT LEAST 580MBS OUT THAT WAY. NAM WINDS UP AROUND THAT LEVEL FORECAST AT 35-40KTS...SO CARBON AND ALBANY COUNTIES COULD BE SEEING WINDS GUSTING TO 40MPH OR MORE. FORTUNATELY...FUELS ARE STILL BEING REPORTED AS NOT READY FOR MOST FIRE ZONES...SO RED FLAG WARNINGS ARE NOT EXPECTED. WINDS EASE SOME FRIDAY AS THE LOW TRACKS EAST INTO SOUTHERN ALBERTA CANADA AND EASTWARD. LESS CLOUD COVERAGE AND 700MB TEMPERATURES CLIMBING TO +16C FRIDAY AND SATURDAY SHOULD LEAD TO SOME VERY WARM TEMPERATURES. DID GO OVER GUIDANCE ON HIGHS FOR THURSDAY AND FRIDAY. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 230 PM MDT WED JUL 22 2015 UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS/HIGH PLAINS WILL MEANDER OVER THAT GENERAL AREA THROUGH THIS PERIOD. THE CWA WILL RESIDE ON THE NORTHERN PERIPHERY OF THE HIGH WITH WARM AND MAINLY DRY WEATHER EXPECTED OVERALL...WITH THE WARMEST DAYS SATURDAY THROUGH MONDAY. A COUPLE DISTURBANCES SHOULD ROTATE OVER THE HIGH AND MAY BRING SOME CONVECTION TO PARTS OF THE CWA...MAINLY SUNDAY AND WEDNESDAY. MONSOONAL MOISTURE LOOKS LIKE IT WILL REMAIN CUT OFF FOR THE MOST PART. AN UPPER LOW WILL MOVE EAST ACROSS THE SOUTHERN CANADIAN PRAIRIES MONDAY THROUGH TUESDAY AND SHOULD DRIVE A COOL FRONT ACROSS THE CWA MONDAY NIGHT WITH TEMPS LOWERING CLOSER TO SEASONAL AVERAGES FOR TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 608 PM MDT WED JUL 22 2015 ISOLATED THUNDERSTORMS PRODUCING WIND GUSTS TO 35 KNOTS THROUGH 02Z...THEN DECREASING CLOUDS. VFR...WITH LOCALIZED MVFR NEAR THUNDERSTORMS. LATE THURSDAY MORNING AND AFTERNOON...WEST WIND GUSTING 25 TO 35 KNOTS. && .FIRE WEATHER... ISSUED AT 230 PM MDT WED JUL 22 2015 A DRIER AND MORE WINDY PERIOD AHEAD FOR THE REMAINDER OF THE WEEK AFTER SHOWERS AND THUNDERSTORMS END TODAY. MONSOONAL MOISTURE FORECAST TO BE SUPPRESSED SOUTH AND EAST BY THURSDAY. LOW PRESSURE TRACKING THROUGH NORTHERN MONTANA THURSDAY WILL AID IN INCREASING WESTERLY TO SOUTHWESTERLY WINDS...ESPECIALLY WEST OF THE LARAMIE RANGE THURSDAY AND FRIDAY. ELEVATED FIRE WEATHER CONCERNS WITH THESE WINDS AND AFTERNOON HUMIDITIES FALLING TO 15 PERCENT BOTH AFTERNOONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...SML SHORT TERM...GCC LONG TERM...RE AVIATION...RUBIN FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
502 PM MDT WED JUL 22 2015 .UPDATE... ISSUED AT 442 PM MDT WED JUL 22 2015 UPDATED THUNDERSTORM CHANCES TO INCLUDE THE NORTHERN NEBRASKA PANHANDLE AND ALL OF EAST CENTRAL WYOMING FOR EARLY THIS EVENING. CURRENTLY A LINE OF THUNDERSTORMS IS MAKING ITS INTO THAT AREA AND WITH A VERY UNSTABLE AIRMASS AND INCREASING SURFACE BASED CAPE VALUES...STORMS SHOULD CONTINUE TO PROPAGATE ACROSS THAT AREA OVER THE NEXT SEVERAL HOURS. WITH LIMITED SHEAR SEVERE THUNDERSTORM THREAT IS ON THE LOW SIDE BUT HIGHER CAPE VALUES DO SUPPORT SOME STRONGER PULSE THUNDERSTORMS. MARGINAL SEVERE HAIL...HEAVY RAIN AND WIND GUSTS TO 60 MPH CAN NOT BE RULED OUT OVER THROUGH EARLY EVENING. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 230 PM MDT WED JUL 22 2015 LATEST WATER VAPOR DEPICTING LAST OF MONSOONAL MOISTURE ACROSS SOUTHEAST WYOMING THIS AFTERNOON. SIGNIFICANT DRYING ON WATER VAPOR OVER MOST OF COLORADO IS INCHING EVER SO SLOWLY NORTHWARD TOWARDS THE SOUTHERN WYOMING BORDER. SEEING SCATTERED SHOWERS AND THUNDERSTORMS ON AREA RADAR THIS AFTERNOON...MAINLY ALONG THE WYOMING/COLORADO BORDER AND MOUNTAIN RANGES TO OUR WEST AND NORTH. SURFACE BASED CAPE OFF THE MESOANALYST PAGE SHOWING RIGHT AROUND 500 J/KG WHERE THESE THUNDERSTORMS ARE FORMING...SO DO NOT EXPECT ANY SEVERE TSTMS FROM THESE. BETTER INSTABILITY ACROSS THE PANHANDLE WHERE CAPES ARE RUNNING 1500-2500 J/KG AT 1 PM THIS AFTERNOON. DEWPOINTS ACROSS THE PANHANDLE NEAR 60 FOR ALLIANCE...SCOTTSBLUFF AND SIDNEY. WILL NEED TO WATCH THUNDERSTORM EVOLUTION AS THE AFTERNOON PROGRESSES OUT THAT WAY. LATEST HRRR FORECAST RADAR SHOWING THE POSSIBILITY OF A FEW STRONG STORMS MAKING IT INTO THIS MORE UNSTABLE AIR IN THE PANHANDLE THIS AFTERNOON AROUND 00Z. CAN NOT RULE OUT ONE OR TWO SEVERE STORMS FOR THIS EVENING OUT THAT WAY. SHEAR OUT THAT WAY ALMOST NONEXISTENT...WITH LONG SKINNY CAPE PROFILES...SO THINK THE MORE PROMINENT HAZARD WOULD BE HEAVY RAIN. ATTENTION TURNS TO ELEVATED FIRE CONDITIONS THURSDAY AND FRIDAY. GFS FORECASTING THE LOW PRESSURE SYSTEM CURRENTLY OVER SOUTHERN BRITISH COLUMBIA...TO TRACK INTO NORTHERN MONTANA THURSDAY. THIS IS A FAVORABLE WIND PATTERN FOR SOUTHEAST WYOMING. AS A RESULT...WESTERLY WINDS BEGIN TO INCREASE OUT ACROSS CARBON AND ALBANY COUNTIES. GFS 700MB WINDS OF 30-35KTS THURSDAY AFTERNOON. LOOKS LIKE THE AREA WILL MIX UP TO AT LEAST 580MBS OUT THAT WAY. NAM WINDS UP AROUND THAT LEVEL FORECAST AT 35-40KTS...SO CARBON AND ALBANY COUNTIES COULD BE SEEING WINDS GUSTING TO 40MPH OR MORE. FORTUNATELY...FUELS ARE STILL BEING REPORTED AS NOT READY FOR MOST FIRE ZONES...SO RED FLAG WARNINGS ARE NOT EXPECTED. WINDS EASE SOME FRIDAY AS THE LOW TRACKS EAST INTO SOUTHERN ALBERTA CANADA AND EASTWARD. LESS CLOUD COVERAGE AND 700MB TEMPERATURES CLIMBING TO +16C FRIDAY AND SATURDAY SHOULD LEAD TO SOME VERY WARM TEMPERATURES. DID GO OVER GUIDANCE ON HIGHS FOR THURSDAY AND FRIDAY. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 230 PM MDT WED JUL 22 2015 UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS/HIGH PLAINS WILL MEANDER OVER THAT GENERAL AREA THROUGH THIS PERIOD. THE CWA WILL RESIDE ON THE NORTHERN PERIPHERY OF THE HIGH WITH WARM AND MAINLY DRY WEATHER EXPECTED OVERALL...WITH THE WARMEST DAYS SATURDAY THROUGH MONDAY. A COUPLE DISTURBANCES SHOULD ROTATE OVER THE HIGH AND MAY BRING SOME CONVECTION TO PARTS OF THE CWA...MAINLY SUNDAY AND WEDNESDAY. MONSOONAL MOISTURE LOOKS LIKE IT WILL REMAIN CUT OFF FOR THE MOST PART. AN UPPER LOW WILL MOVE EAST ACROSS THE SOUTHERN CANADIAN PRAIRIES MONDAY THROUGH TUESDAY AND SHOULD DRIVE A COOL FRONT ACROSS THE CWA MONDAY NIGHT WITH TEMPS LOWERING CLOSER TO SEASONAL AVERAGES FOR TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1125 AM MDT WED JUL 22 2015 VFR EXPECTED OVERALL OVER THE TERMINALS THROUGH THE PERIOD. THERE WILL BE WDLY SCTD SHOWERS AND TSTRMS DEVELOPING OVER THE SE WY MTNS THIS AFTERNOON AND MOVING EAST OVER PARTS OF THE PLAINS INTO THIS EVENING BEFORE ENDING. BRIEF PDS OF GUSTY WINDS AND MVFR VSBYS IN STRONGER ACTIVITY. && .FIRE WEATHER... ISSUED AT 230 PM MDT WED JUL 22 2015 A DRIER AND MORE WINDY PERIOD AHEAD FOR THE REMAINDER OF THE WEEK AFTER SHOWERS AND THUNDERSTORMS END TODAY. MONSOONAL MOISTURE FORECAST TO BE SUPPRESSED SOUTH AND EAST BY THURSDAY. LOW PRESSURE TRACKING THROUGH NORTHERN MONTANA THURSDAY WILL AID IN INCREASING WESTERLY TO SOUTHWESTERLY WINDS...ESPECIALLY WEST OF THE LARAMIE RANGE THURSDAY AND FRIDAY. ELEVATED FIRE WEATHER CONCERNS WITH THESE WINDS AND AFTERNOON HUMIDITIES FALLING TO 15 PERCENT BOTH AFTERNOONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...SML SHORT TERM...GCC LONG TERM...RE AVIATION...RE FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
102 PM MDT TUE JUL 21 2015 .UPDATE... ISSUED AT 1005 AM MDT TUE JUL 21 2015 LIGHT SHOWERS CONTINUE ACROSS MUCH OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE THIS MORNING. CLOUD COVER AND SHOWER ACTIVITY WILL LIKELY DECREASE THE AFTERNOON THUNDERSTORM COVERAGE AND STRENGTH OF THUNDERSTORMS. WATERVAPOR IMAGERY IS SHOWING A POCKET OF DRIER AIR ASSOCIATED WITH A SHORTWAVE JUST SOUTH OF THE WYOMING BORDER. THIS WAVE WILL LIFT NORTHEAST INTO SOUTHEAST WYOMING THIS AFTERNOON AND WILL BE THE MAIN FOCUS AREA FOR THUNDERSTORMS. AT THIS POINT NOT DO NOT SEE ANY CHANCES FOR SEVERE THUNDERSTORMS TODAY...IN FACT THUNDERSTORMS WILL GENERALLY BE WEAK TODAY. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 330 AM MDT TUE JUL 21 2015 500 MB ANALYSIS SHOWS A WEAK SHORTWAVE ACROSS SOUTHWESTERN WYOMING WITH WIDESPREAD MID LEVEL CLOUDS AND SCATTERED SHOWERS TO THE EAST OF THE LARAMIE RANGE. THE WEAK UPPER LEVEL DISTURBANCE IS PROGGED TO PASS OVERHEAD THROUGH THE DAY. THE HRRR AND GFS/NAM SHOW SHOWERS INCREASING IN COVERAGE ACROSS THE PLAINS THROUGH THE MORNING...AND ESPECIALLY ACROSS THE NEBRASKA PANHANDLE. INSTABILITY INCREASES BY AROUND 18Z WITH CAPE VALUES OF 750 TO 1250 J/KG THROUGH THE AFTN. WILL KEEP THE HIGH POPS (40 TO 60 PERCENT) GOING THROUGH THE LATE AFTN ACROSS THE PLAINS AS THE SHORTWAVE INTERACTS WITH PLENTIFUL SUBTROPICAL MOISTURE ALONG WITH DECENT LOW LEVEL MOISTURE. MAIN CONCERN WITH THE CONVECTION WILL BE HEAVY RAIN WITH PW VALUES ABOVE NORMAL (ABOVE 1 INCH). MAY ALSO BE SOME SMALL HAIL WITH BULK SHEAR AROUND 30 KT...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN FCST. TEMPS WILL BE COOLER TODAY WITH THE WIDESPREAD CLOUD COVER. THE RAIN WILL TAPER OFF BY THE LATE EVENING AS SUBSIDENCE KICKS IN BEHIND THE SHORTWAVE. CHANCES FOR STORMS WILL BE LESS ON WEDNESDAY AS HEIGHTS ALOFT BEGIN TO RISE. HOWEVER...700 TO 500 MB FLOW IS STILL SOUTHWESTERLY WITH MODEST SUBTROPICAL MOISTURE STREAMING INTO WYOMING AND PW VALUES OF 0.75 TO 1 INCH. COULD SEE SCATTERED AFTN STORMS DEVELOP OVER MUCH OF SOUTHEAST WYOMING WITH THE MAIN THREAT BEING BRIEF HEAVY RAIN. INSTABILITY IS QUITE A BIT LESS THAN TODAY SO SMALL HAIL IS NOT MUCH OF A THREAT. HIGH TEMPS WILL RISE 5 TO 10 DEGREES. MUCH MORE DRYING IS STILL PROGGED FOR THURSDAY AS THE SUBTROPICAL MOISTURE PLUME SHIFTS OUT OF SOUTHERN WYOMING. SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE AS A SFC TROUGH DEVELOPS OVER WESTERN SOUTH DAKOTA. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 330 AM MDT TUE JUL 21 2015 THE 00Z MEDIUM RANGE MODELS ARE IN AGREEMENT DEPICTING A LARGE SCALE UPPER RIDGE OVER THE NATION`S MIDSECTION...WITH THE MORE ACTIVE WESTERLIES CONFINED ACROSS THE NORTHERN TIER THROUGH THE WEEKEND. THE FLOW ALOFT WILL BE WEST TO SOUTHWEST...WITH MOST OF THE SUBTROPICAL MOISTURE TO THE SOUTH AND WEST OF THE REGION. THE ECMWF...AND TO A LESSER EXTENT THE GFS...HINT AT SOME MOISTURE TRYING TO SNEAK NORTHWARD ACROSS THE HIGH PLAINS SATURDAY AND SUNDAY FOR ISOLATED AFTERNOON/EVENING CONVECTION. IT WILL BE WARM FRIDAY THROUGH SUNDAY WITH HIGHS FROM THE MID 80S TO LOW 90S. A SURFACE TROUGH MOVES INTO THE HIGH PLAINS MONDAY...WITH A WEAK SHORTWAVE PASSING OVERHEAD. THE ECMWF QPF LOOKS OVERDONE COMPARED TO THE GFS...WITH LOW POPS FOR THE SOUTHEAST WYOMING MOUNTAINS. HIGH TEMPERATURES MONDAY WILL BE A FEW DEGREES COOLER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1255 PM MDT TUE JUL 21 2015 RADAR DATA FROM KCYS SHOWS A BROAD AREA OF MODERATE RAIN FALLING ACROSS THE CENTRAL AND SOUTHERN NEBRASKA PANHANDLE...EXTENDING SOUTHWEST TOWARDS CYS. EXPECT THIS TREND TO CONTINUE THRU THE EARLY EVENING HOURS AS A DISTURBANCES LIFTS ACROSS THE REGION. EXPECT CONDITIONS IN GENERAL TO REMAIN VFR...THOUGH WILL SEE PERIODIC BOUTS WITH MVFR CONDITIONS IN BOTH CIGS/VSBYS. HAVE INCLUDED TEMPO GROUPS AT CYS AND ALL NEBRASKA PANHANDLE LOCATIONS AS COVERAGE WILL BE SUFFICIENT. THIS CONVECTIVE ACTIVITY WILL DISSIPATE 03-06Z. MAY SEE SOME PATCHY FOG DEVELOP IN THE VICINITY OF THE NORTH PLATTE RIVER VALLEY...WHICH WOULD MAINLY IMPACT BFF 10-14Z. && .FIRE WEATHER... ISSUED AT 330 AM MDT TUE JUL 21 2015 MINIMAL FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY FOR AREAS TO THE EAST OF THE LARAMIE RANGE. A DRIER AIR MASS WILL MOVE INTO THE REGION WEDNESDAY AND ESPECIALLY THURSDAY. THURSDAY AFTERNOON...MINIMUM HUMIDITY VALUES WILL DROP TO 15 TO 25 PERCENT OVER LOWER ELEVATIONS AND SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...SML SHORT TERM...ZF LONG TERM...MAJ AVIATION...CAH FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1011 AM MDT TUE JUL 21 2015 .UPDATE... ISSUED AT 1005 AM MDT TUE JUL 21 2015 LIGHT SHOWERS CONTINUE ACROSS MUCH OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE THIS MORNING. CLOUD COVER AND SHOWER ACTIVITY WILL LIKELY DECREASE THE AFTERNOON THUNDERSTORM COVERAGE AND STRENGTH OF THUNDERSTORMS. WATERVAPOR IMAGERY IS SHOWING A POCKET OF DRIER AIR ASSOCIATED WITH A SHORTWAVE JUST SOUTH OF THE WYOMING BORDER. THIS WAVE WILL LIFT NORTHEAST INTO SOUTHEAST WYOMING THIS AFTERNOON AND WILL BE THE MAIN FOCUS AREA FOR THUNDERSTORMS. AT THIS POINT NOT DO NOT SEE ANY CHANCES FOR SEVERE THUNDERSTORMS TODAY...IN FACT THUNDERSTORMS WILL GENERALLY BE WEAK TODAY. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 330 AM MDT TUE JUL 21 2015 500 MB ANALYSIS SHOWS A WEAK SHORTWAVE ACROSS SOUTHWESTERN WYOMING WITH WIDESPREAD MID LEVEL CLOUDS AND SCATTERED SHOWERS TO THE EAST OF THE LARAMIE RANGE. THE WEAK UPPER LEVEL DISTURBANCE IS PROGGED TO PASS OVERHEAD THROUGH THE DAY. THE HRRR AND GFS/NAM SHOW SHOWERS INCREASING IN COVERAGE ACROSS THE PLAINS THROUGH THE MORNING...AND ESPECIALLY ACROSS THE NEBRASKA PANHANDLE. INSTABILITY INCREASES BY AROUND 18Z WITH CAPE VALUES OF 750 TO 1250 J/KG THROUGH THE AFTN. WILL KEEP THE HIGH POPS (40 TO 60 PERCENT) GOING THROUGH THE LATE AFTN ACROSS THE PLAINS AS THE SHORTWAVE INTERACTS WITH PLENTIFUL SUBTROPICAL MOISTURE ALONG WITH DECENT LOW LEVEL MOISTURE. MAIN CONCERN WITH THE CONVECTION WILL BE HEAVY RAIN WITH PW VALUES ABOVE NORMAL (ABOVE 1 INCH). MAY ALSO BE SOME SMALL HAIL WITH BULK SHEAR AROUND 30 KT...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN FCST. TEMPS WILL BE COOLER TODAY WITH THE WIDESPREAD CLOUD COVER. THE RAIN WILL TAPER OFF BY THE LATE EVENING AS SUBSIDENCE KICKS IN BEHIND THE SHORTWAVE. CHANCES FOR STORMS WILL BE LESS ON WEDNESDAY AS HEIGHTS ALOFT BEGIN TO RISE. HOWEVER...700 TO 500 MB FLOW IS STILL SOUTHWESTERLY WITH MODEST SUBTROPICAL MOISTURE STREAMING INTO WYOMING AND PW VALUES OF 0.75 TO 1 INCH. COULD SEE SCATTERED AFTN STORMS DEVELOP OVER MUCH OF SOUTHEAST WYOMING WITH THE MAIN THREAT BEING BRIEF HEAVY RAIN. INSTABILITY IS QUITE A BIT LESS THAN TODAY SO SMALL HAIL IS NOT MUCH OF A THREAT. HIGH TEMPS WILL RISE 5 TO 10 DEGREES. MUCH MORE DRYING IS STILL PROGGED FOR THURSDAY AS THE SUBTROPICAL MOISTURE PLUME SHIFTS OUT OF SOUTHERN WYOMING. SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE AS A SFC TROUGH DEVELOPS OVER WESTERN SOUTH DAKOTA. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 330 AM MDT TUE JUL 21 2015 THE 00Z MEDIUM RANGE MODELS ARE IN AGREEMENT DEPICTING A LARGE SCALE UPPER RIDGE OVER THE NATION`S MIDSECTION...WITH THE MORE ACTIVE WESTERLIES CONFINED ACROSS THE NORTHERN TIER THROUGH THE WEEKEND. THE FLOW ALOFT WILL BE WEST TO SOUTHWEST...WITH MOST OF THE SUBTROPICAL MOISTURE TO THE SOUTH AND WEST OF THE REGION. THE ECMWF...AND TO A LESSER EXTENT THE GFS...HINT AT SOME MOISTURE TRYING TO SNEAK NORTHWARD ACROSS THE HIGH PLAINS SATURDAY AND SUNDAY FOR ISOLATED AFTERNOON/EVENING CONVECTION. IT WILL BE WARM FRIDAY THROUGH SUNDAY WITH HIGHS FROM THE MID 80S TO LOW 90S. A SURFACE TROUGH MOVES INTO THE HIGH PLAINS MONDAY...WITH A WEAK SHORTWAVE PASSING OVERHEAD. THE ECMWF QPF LOOKS OVERDONE COMPARED TO THE GFS...WITH LOW POPS FOR THE SOUTHEAST WYOMING MOUNTAINS. HIGH TEMPERATURES MONDAY WILL BE A FEW DEGREES COOLER. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 330 AM MDT TUE JUL 21 2015 VFR CEILINGS WILL PREVAIL FOR THE MOST PART THROUGH TONIGHT. THERE WILL BE BRIEF PERIODS OF MVFR CEILINGS AND VISIBILITY WITH SHRA AND TSRA AS WELL AS GUSTY WINDS...ESPECIALLY THIS AFTERNOON AND EARLY EVENING. THE LATEST NAM/SREF MODELS ARE INDICATING MVFR TO IFR CEILINGS DEVELOPING ACROSS MUCH OF WESTERN NEBRASKA LATE TONIGHT...AND WILL BE TRENDING THAT DIRECTION WITH THIS TAF PACKAGE. && .FIRE WEATHER... ISSUED AT 330 AM MDT TUE JUL 21 2015 MINIMAL FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY FOR AREAS TO THE EAST OF THE LARAMIE RANGE. A DRIER AIR MASS WILL MOVE INTO THE REGION WEDNESDAY AND ESPECIALLY THURSDAY. THURSDAY AFTERNOON...MINIMUM HUMIDITY VALUES WILL DROP TO 15 TO 25 PERCENT OVER LOWER ELEVATIONS AND SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...SML SHORT TERM...ZF LONG TERM...MAJ AVIATION...MAJ FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
338 AM MDT TUE JUL 21 2015 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 330 AM MDT TUE JUL 21 2015 500 MB ANALYSIS SHOWS A WEAK SHORTWAVE ACROSS SOUTHWESTERN WYOMING WITH WIDESPREAD MID LEVEL CLOUDS AND SCATTERED SHOWERS TO THE EAST OF THE LARAMIE RANGE. THE WEAK UPPER LEVEL DISTURBANCE IS PROGGED TO PASS OVERHEAD THROUGH THE DAY. THE HRRR AND GFS/NAM SHOW SHOWERS INCREASING IN COVERAGE ACROSS THE PLAINS THROUGH THE MORNING...AND ESPECIALLY ACROSS THE NEBRASKA PANHANDLE. INSTABILITY INCREASES BY AROUND 18Z WITH CAPE VALUES OF 750 TO 1250 J/KG THROUGH THE AFTN. WILL KEEP THE HIGH POPS (40 TO 60 PERCENT) GOING THROUGH THE LATE AFTN ACROSS THE PLAINS AS THE SHORTWAVE INTERACTS WITH PLENTIFUL SUBTROPICAL MOISTURE ALONG WITH DECENT LOW LEVEL MOISTURE. MAIN CONCERN WITH THE CONVECTION WILL BE HEAVY RAIN WITH PW VALUES ABOVE NORMAL (ABOVE 1 INCH). MAY ALSO BE SOME SMALL HAIL WITH BULK SHEAR AROUND 30 KT...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN FCST. TEMPS WILL BE COOLER TODAY WITH THE WIDESPREAD CLOUD COVER. THE RAIN WILL TAPER OFF BY THE LATE EVENING AS SUBSIDENCE KICKS IN BEHIND THE SHORTWAVE. CHANCES FOR STORMS WILL BE LESS ON WEDNESDAY AS HEIGHTS ALOFT BEGIN TO RISE. HOWEVER...700 TO 500 MB FLOW IS STILL SOUTHWESTERLY WITH MODEST SUBTROPICAL MOISTURE STREAMING INTO WYOMING AND PW VALUES OF 0.75 TO 1 INCH. COULD SEE SCATTERED AFTN STORMS DEVELOP OVER MUCH OF SOUTHEAST WYOMING WITH THE MAIN THREAT BEING BRIEF HEAVY RAIN. INSTABILITY IS QUITE A BIT LESS THAN TODAY SO SMALL HAIL IS NOT MUCH OF A THREAT. HIGH TEMPS WILL RISE 5 TO 10 DEGREES. MUCH MORE DRYING IS STILL PROGGED FOR THURSDAY AS THE SUBTROPICAL MOISTURE PLUME SHIFTS OUT OF SOUTHERN WYOMING. SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE AS A SFC TROUGH DEVELOPS OVER WESTERN SOUTH DAKOTA. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 330 AM MDT TUE JUL 21 2015 THE 00Z MEDIUM RANGE MODELS ARE IN AGREEMENT DEPICTING A LARGE SCALE UPPER RIDGE OVER THE NATION`S MIDSECTION...WITH THE MORE ACTIVE WESTERLIES CONFINED ACROSS THE NORTHERN TIER THROUGH THE WEEKEND. THE FLOW ALOFT WILL BE WEST TO SOUTHWEST...WITH MOST OF THE SUBTROPICAL MOISTURE TO THE SOUTH AND WEST OF THE REGION. THE ECMWF...AND TO A LESSER EXTENT THE GFS...HINT AT SOME MOISTURE TRYING TO SNEAK NORTHWARD ACROSS THE HIGH PLAINS SATURDAY AND SUNDAY FOR ISOLATED AFTERNOON/EVENING CONVECTION. IT WILL BE WARM FRIDAY THROUGH SUNDAY WITH HIGHS FROM THE MID 80S TO LOW 90S. A SURFACE TROUGH MOVES INTO THE HIGH PLAINS MONDAY...WITH A WEAK SHORTWAVE PASSING OVERHEAD. THE ECMWF QPF LOOKS OVERDONE COMPARED TO THE GFS...WITH LOW POPS FOR THE SOUTHEAST WYOMING MOUNTAINS. HIGH TEMPERATURES MONDAY WILL BE A FEW DEGREES COOLER. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 330 AM MDT TUE JUL 21 2015 VFR CEILINGS WILL PREVAIL FOR THE MOST PART THROUGH TONIGHT. THERE WILL BE BRIEF PERIODS OF MVFR CEILINGS AND VISIBILITY WITH SHRA AND TSRA AS WELL AS GUSTY WINDS...ESPECIALLY THIS AFTERNOON AND EARLY EVENING. THE LATEST NAM/SREF MODELS ARE INDICATING MVFR TO IFR CEILINGS DEVELOPING ACROSS MUCH OF WESTERN NEBRASKA LATE TONIGHT...AND WILL BE TRENDING THAT DIRECTION WITH THIS TAF PACKAGE. && .FIRE WEATHER... ISSUED AT 330 AM MDT TUE JUL 21 2015 MINIMAL FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY FOR AREAS TO THE EAST OF THE LARAMIE RANGE. A DRIER AIR MASS WILL MOVE INTO THE REGION WEDNESDAY AND ESPECIALLY THURSDAY. THURSDAY AFTERNOON...MINIMUM HUMIDITY VALUES WILL DROP TO 15 TO 25 PERCENT OVER LOWER ELEVATIONS AND SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...ZF LONG TERM...MAJ AVIATION...MAJ FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
122 AM EDT THU JUL 23 2015 .PREV DISCUSSION... /ISSUED 802 PM EDT WED JUL 22 2015/ UPDATE... EVENING CONVECTION WILL CONTINUE FOR THE NEXT SEVERAL HOURS. UPDATED POPS EARLIER TO REFLECT THE CURRENT RADAR AND HRRR TRENDS. MAIN UPDATE IS TO REMOVE THE HEAT ADVISORY. PREV DISCUSSION... /ISSUED 257 PM EDT WED JUL 22 2015/ SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... SHORT TERM /TODAY THROUGH THURSDAY/... CURRENT RADAR LOOP SHOWS SHOWERS WITH SOME ISOLATED THUNDERSTORMS MOVING INTO NW GA. WEAK WEST TO NORTHWEST FLOW IS STILL EXPECTED TO BECOME A LITTLE MORE ACTIVE OVER THE NEXT 24 HOURS. EXCEPTING TO SEE MORE AREAL COVERAGE TODAY THAN YESTERDAY WITH THE PRECIPITATION BUT THURSDAY APPEARS TO BE OUR MOT ACTIVE DAY. DEEPER MOISTURE OVER TN WILL CONTINUE TO SINK SOUTH INTO GA THROUGH THU AFTERNOON BRINGING A STRONGER SHORT WAVE AND LIKELY POPS TO THE STATE. ALSO EXPECTING INCREASED INSTABILITY SO THE MARGINAL RISK AREA SPC HAS OVER ALMOST THE ENTIRE STATE FOR DAY 2 STILL LOOKS GOOD. PERSISTENCE ON TEMPS ACROSS CENTRAL GA LOOKS GOOD WITH SLIGHTLY COOLER TEMPS ACROSS NORTH GA. COOLER TEMPS CWA WIDE ON THURSDAY DUE TO ADDITIONAL CLOUDS AND PRECIP. 01 LONG TERM /FRIDAY THROUGH WEDNESDAY/... NOT MANY CHANGES TO THE PREVIOUS LONG TERM FORECAST. FOR FRIDAY...LARGE SCALE SYNOPTIC PATTERN WILL BE DOMINATED BY BROAD MID-LEVEL RIDGING OVER THE SOUTHERN PLAINS...SUPPORTING NORTHWEST FLOW ALOFT ACROSS THE SOUTHEAST US. A WEAK DISTURBANCE WITHIN THIS FLOW WILL INTERACT WITH A NEARLY STATIONARY SURFACE BOUNDARY TO PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT...PARTICULARLY ACROSS THE CENTRAL PORTION OF THE CWA DURING THE AFTERNOON. MEANWHILE...DRIER AIR WILL BEGIN TO FILTER INTO THE NORTHERN PORTION OF THE CWA. SATURDAY AND SUNDAY...RELATIVELY TRANQUIL WEATHER EXPECTED AS SURFACE HIGH PRESSURE RIDGES DOWN THE SPINE OF THE APPALACHIANS AND H5 RIDGE BEGINS TO BUILD SLIGHTLY EAST OVER THE SOUTHEAST. RELATIVELY DRIER AIR /PW VALUES 1-1.50INCHES/ SHOULD SUPPRESS WIDESPREAD CONVECTION...BUT CANNOT RULE OF A FEW DIURNALLY ENHANCED THUNDERSTORMS WITH THE CONTINUED WARM TEMPERATURES. MONDAY THROUGH WEDNESDAY...EXPECT A GRADUAL INCREASE IN MOISTURE DURING THIS PERIOD. POTENT TROUGH MOVING ACROSS NORTHERN ROCKIES WILL FLATTEN THE PERSISTENT H5 RIDGE AND GENERATE MINOR PERTURBATIONS IN THE MID LEVEL FLOW PATTERN. GFS AND ECMWF BOTH INDICATE RIDGE WILL SUPPRESS WIDESPREAD PRECIPITATION FOR THE MOST PART MONDAY AND TUESDAY...BUT DO EXPECT THESE DISTURBANCES TO AFFECT THE AREA BY MID WEEK. THEREFORE...EXPECT POPS TO INCREASE BY WEDNESDAY. WILL ALSO CONTINUE TO MONITOR THE POTENTIAL FOR A PSUEDO-TROPICAL DISTURBANCE DEVELOPING OFF THE EAST COAST OF FLORIDA AT THE END OF THE PERIOD...AS INDICATED BY THE ECMWF. KOVACIK && .AVIATION... 06Z UPDATE... VFR CONDITIONS WILL REMAIN THROUGH THE FORECAST. THE EXCEPTION WILL BE EARLY THIS MORNING IN AHN/MCN WHERE LIGHT FOG COULD REDUCE VSBYS TO 3-5SM. A FEW SHOWERS REMAIN POSSIBLE OVER THE FORECAST AREA EARLY THIS MORNING BUT COVERAGE SHOULD INCREASE THIS MORNING WITH WIDESPREAD SHRA/TSRA THIS AFTERNOON. COVERAGE SHOULD DISSIPATE SOMEWHAT TONIGHT. WINDS WILL REMAIN WESTERLY...INCREASE TO NEAR 10KTS BY AFTERNOON WITH A FEW GUSTS...HOWEVER GUSTS IN TSRA COULD REACH 30 TO 35 KTS. //ATL CONFIDENCE...06Z UPDATE... MEDIUM ON TIMING OF TSRA HIGH ON REMAINING ELEMENTS. 17 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 90 73 91 73 / 70 60 40 30 ATLANTA 88 73 90 75 / 70 60 30 20 BLAIRSVILLE 84 66 85 67 / 70 60 30 20 CARTERSVILLE 86 73 90 73 / 70 60 30 20 COLUMBUS 92 75 93 77 / 60 60 40 30 GAINESVILLE 89 72 88 72 / 70 60 30 20 MACON 93 75 93 75 / 60 60 40 40 ROME 88 72 91 72 / 70 60 30 20 PEACHTREE CITY 89 73 90 73 / 70 60 30 30 VIDALIA 95 76 93 75 / 60 60 50 50 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...17 LONG TERM....BDL AVIATION...17
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
255 AM EDT THU JUL 23 2015 .UPDATE... ISSUED AT 225 AM EDT THU JUL 23 2015 ADJUSTMENTS HAVE BEEN MADE TO HOURLY TEMPERATURE AND DEWPOINT TRENDS BASED ON RECENT OBSERVATIONS. POPS WERE ADJUSTED UP SLIGHTLY TOWARD DAWN IN THE SW PART OF THE CWA AHEAD OF AN APPROACHING DISTURBANCE. OTHERWISE...NO CHANGES. UPDATE ISSUED AT 1100 PM EDT WED JUL 22 2015 HAVE ONLY MADE VERY MINOR CHANGES ONCE AGAIN...BASED LATE EVENING OBS/TRENDS. UPDATE ISSUED AT 837 PM EDT WED JUL 22 2015 MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST BASED ON LATEST OBS AND 18Z MODEL RUNS...WITH LITTLE SUBSTANTIVE CHANGE. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 310 PM EDT WED JUL 22 2015 18Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING DEEPER INTO THE OHIO VALLEY AND NORTHERN KENTUCKY. THIS HAS BROUGHT DRIER AIR TO THE NORTHERN SECTIONS OF THE CWA WHERE SOME MID 50S ARE NOTED WHILE TO THE SOUTH MIDDLE AND UPPER 60S ARE COMMON. THE HIGH ALSO HELPED TO BREAK UP AND LIFT THE LOWER STRATUS DECK FROM THIS MORNING. ON SATELLITE AND RADAR...A PAIR OF MCVS ARE MOVING EAST INTO AND THROUGH THE TENNESSEE VALLEY. THE LEADING ONE OF THESE IS JUST ABOUT TO PUSH SOME LIGHT SHOWERS INTO THE CUMBERLAND VALLEY NEAR THE TENNESSEE BORDER. OTHERWISE...IT IS A PLEASANT ENOUGH DAY OUT THERE UNDER PARTLY SUNNY DAYS WITH TEMPERATURES RANGING FROM NEAR 80 NORTH TO THE MID 80S SOUTH ALONG WITH LIGHT NORTHWEST WINDS. THE MODELS ARE IN GOOD AGREEMENT WITH THE MAIN PATTERN ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE THAT FLAT FLOW CURRENTLY ABOVE KENTUCKY WILL BECOME MORE NORTHWESTERLY WITH TIME AS RIDGING BUILDS OVER THE SOUTHERN PLAINS INTO FRIDAY MORNING. DURING THIS TRANSITION...WEAK SHORTWAVES WILL RIDE THROUGH KENTUCKY STARTING WITH THE MCVS PASSING TO THE SOUTH THIS AFTERNOON AND TONIGHT. GIVEN THE SMALL SCALE NATURE OF THESE FEATURES WILL FAVOR THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX DETAILS. SENSIBLE WEATHER WILL FEATURE A SMALL CHANCE FOR SHOWERS OR A STRAY THUNDERSTORM ACROSS THE SOUTHERN TIER THROUGH THE EVENING AND INTO THE OVERNIGHT AS THE MINOR MID LEVEL WAVES PASS BY. THE CLOUDS ASSOCIATED WITH THESE SHOULD KEEP THE FOG A BIT MORE LIMITED THROUGH THE NIGHT AND INTO THURSDAY MORNING. THE THREAT OF CONVECTION CONTINUES FOR MUCH OF THE SOUTHERN PARTS OF THE AREA DURING THE DAY THURSDAY...BUT WITH LITTLE IN THE WAY OF SUPPORT FOR ANYTHING BECOMING ORGANIZED OR TOO STRONG. THIS LEADS TO A BETTER CHANCE FOR VALLEY FOG LATER THURSDAY NIGHT AS THE WAVES PULL OUT OF KENTUCKY. TEMPERATURES WILL BE NEAR NORMAL OR A LITTLE ON THE COOL SIDE THROUGH FRIDAY MORNING. USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WINDS INTO TONIGHT AND THEN THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS TO THE LOWS TONIGHT AND THURSDAY NIGHT BASED ON TERRAIN DIFFERENCES AND THE EXPECTATION OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE DRIER MET MOS THAN THE MAV TONIGHT AND THURSDAY WHILE WAS IN LINE WITH THE LOW POP CONSENSUS FOR THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 245 PM EDT WED JUL 22 2015 UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BE ENTRENCHED OVER TEXAS AND THE SOUTHERN PLAINS THROUGH THE PERIOD KEEPING NORTHWEST FLOW IN PLACE ACROSS THE OHIO AND TENNESSEE VALLEYS. DRY HIGH PRESSURE WILL BE IN PLACE AT THE SURFACE FRIDAY AND SATURDAY WITH A DRY AND SEASONABLY WARM AND NOT SO HUMID FORECAST THE RESULT. A SHORTWAVE WILL THEN TRAVERSE THE US/CANADIAN BORDER OVER THE WEEKEND FLATTENING THE RIDGE AND SENDING A WEAK COLD FRONT SOUTHEASTWARD TOWARD OUR REGION. THE FRONT IS EXPECTED TO REMAIN IN THE VICINITY WHILE GRADUALLY WASHING OUT EARLY NEXT WEEK. THIS WILL KEEP A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS IN OUR FORECAST SUNDAY THROUGH WEDNESDAY...WITH COVERAGE LIKELY PEAKING IN THE AFTERNOON AND EARLY EVENING HOURS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 235 AM EDT THU JUL 23 2015 A PASSING MID LEVEL DISTURBANCE AND SFC WAVE OF LOW PRESSURE PASSING SOUTH OF THE AREA WILL BRING INCREASING MOISTURE AND THE THREAT FOR SHRA AND POSSIBLY EVEN TSRA ACROSS THE SOUTH. GENERALLY VFR CIGS AND VIS ARE EXPECTED WITH THIS ALTHOUGH LOCATIONS SOUTH OF THE TAF SITES NEAR THE VA AND TN BORDERS MAY EXPERIENCE SOME VFR BETWEEN 12Z AND 0Z MAINLY IN ANY HEAVIER SHOWERS OR TSRA. WINDS WILL BE LIGHT THROUGH THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...ABE AVIATION...JP
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1140 PM CDT WED JUL 22 2015 .UPDATE... ISSUED AT 1140 PM CDT WED JUL 22 2015 UPDATED AVIATION SECTION FOR 06Z TAF PACKAGE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 231 PM CDT WED JUL 22 2015 MINOR DISTURBANCE SEEN OVER SW MO HEADING EAST WITH SOME UPTICK IN CONVECTION NOTED. HRRR HAS A REASONABLE HANDLE ON THIS ACTIVITY THROUGH 00Z-03Z...MOVING THE ACTIVITY EAST. LIGHTNING PROGS OFF THE REFRESH MODEL NOT IMPRESSIVE...AND AS PREVIOUSLY DISCUSSED... MID LEVEL MARGINAL LAPSE RATES AND WEAK ML CAPES MEANS WE WILL KEEP THUNDER MENTION AT ISOLATED. BETTER POPS WILL BE ACROSS SE MO INTO WRN KY AND SRN TIP OF IL INITIALLY. SHOULD REMAIN DRY EARLY TONIGHT UP ALONG THE I-64 CORRIDOR. SUPPOSE A SPRINKLE CANNOT BE RULED OUT THERE. OVERNIGHT...THE CHANCE OF CONVECTION WILL CONTINUE...WITH BEST POPS SRN 1/2 OF THE AREA. A SLIGHT NORTHWARD EXPANSION IS FORECAST ESPECIALLY BY THE NAM EVEN UP TOWARD THE KEVV TRI-STATE AS MOISTURE INCREASES THAT DIRECTION. WILL GUIDE POPS INTO THAT AREA. THURSDAY...BEST POPS WILL SHIFT SE WITH TIME COINCIDENT WITH THE DEPARTURE OF MID LEVEL ENERGY AND BEST MOISTURE...AND AS THE MID TROP FLOW VEERS MORE TO THE NW. THE VEERING WILL CONTINUE WITH DRYING INCREASING EAST OF THE MISSISSIPPI INTO THURSDAY NIGHT. WE DO CONTINUE WITH A CHANCE OF CONVECTION OVER SE MO WHERE MOISTURE AND INSTABILITY ARE FORECAST TO EXIST. THAT CHANCE WILL CONTINUE INTO AT LEAST THE FIRST 1/2 OF FRIDAY BEFORE HEADING SSE. FRIDAY NIGHT DRY FOR NOW...BUT THIS IS NOT A GIVEN. WE COULD SEE AN EASTWARD EXPANSION OF THE MOISTURE OUT OF MISSOURI WHICH COULD LEAD TO SOME LATE NIGHT CONVECTION. THERE IS CONSIDERABLE MODEL DISAGREEMENT WITH RESPECT TO THIS. WILL WAIT FOR A MORE CONSISTENT SIGNAL. TEMPERATURES ARE ESSENTIALLY A BLEND OF MOS. TRENDED AWAY FROM GFS MOS WHEN IT WAS AT ITS WARMEST ESPECIALLY FRIDAY. IT HAS NOT PERFORMED WELL AS OF LATE...ESPECIALLY DURING THE RECENT HEAT EVENT (OPPRESSIVE EVAPOTRANSPIRATION EFFECTS/HIGH DEW POINT AIR) IN WHICH AMBIENT TEMPS SEEMED TO REACH A LIMIT...JUST BELOW WHAT GUIDANCE WOULD PROJECT FOR HIGHS. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 231 PM CDT WED JUL 22 2015 THOUGH THE FINER DETAILS ARE MORE DIFFICULT TO PIN DOWN...THE GENERAL SCENARIO IN THE EXTENDED TIME FRAME WILL BE THE PAH FORECAST AREA WILL BE ON THE PERIPHERY OF A MID/UPPER LEVEL RIDGE OVER MOST OF THE SRN STATES. TWO MAIN NRN STREAM SHRTWVS ARE PROGGED BY THE MED RANGE MODELS TO MOVE BY TO THE NORTH...ONE DURING THE WEEKEND... AND ONE IN THE MIDDLE OF NEXT WEEK. EACH SHOULD ENHANCE SOMEWHAT THE LIKELIHOOD OF SHOWER AND TSTM DEVELOPMENT ACROSS PARTS OF OUR REGION. EARLY IN THE PERIOD...A NORTH-SOUTH FRONTAL BOUNDARY IS EXPECTED TO BE IN PLACE IN FAR WRN SECTIONS OF THE PAH FORECAST AREA. MEANWHILE...A LINGERING WEDGE OF RELATIVELY DRIER AIR WILL BE IN PLACE OVER THE REST OF THE REGION. LOW LEVEL WINDS SHOULD EVENTUALLY TURN AROUND TO THE SOUTH OVER THE WEEKEND...ENCOURAGING MORE MOISTURE ADVECTION INTO THE AREA. WITH THIS SETUP...AFTERNOON TEMPS AND DEWPOINTS SHOULD BE SEVERAL DEGREES HIGHER IN THE WEST VS. THE EAST ESPECIALLY SAT. THUS...HEAT INDICES COULD SPIKE TO HEAT ADVISORY CRITERIA IN THE WEST OVER THE WEEKEND. HEAT INDICES BETWEEN 100 AND 105 SHOULD BE MORE COMMON ACROSS THE ENTIRE REGION AFTERWARDS. THE MED RANGE MODELS GENERALLY DEPICT THE PRESENCE OF NRN STREAM SHRTWV ENERGY ALOFT IN THE AREA BY EARLY SUNDAY. THE DESTABILIZING EFFECT OF THIS FEATURE WILL COMBINE WITH THE INCREASINGLY UNSTABLE AIRMASS TO GENERATE SCATTERED SHOWER AND TSTM ACTIVITY PRIMARILY SUNDAY/SUNDAY NIGHT...WITH THE PENNYRILE REGION OF WRN KY HAVING THE LEAST POP. IF A SEWD-MOVING SFC BOUNDARY MAKES IT INTO OUR AREA BY SUNDAY NIGHT...IT MAY BECOME UNRECOGNIZABLE. THE MODEL BLEND SHOWS A PERSISTENT SRLY COMPONENT TO THE SFC WINDS THROUGH SUNDAY NIGHT AND BEYOND. IT APPEARS A SIMILAR PATTERN WILL SET UP EARLY NEXT WEEK...AS ANOTHER SFC BOUNDARY MAY SET UP IN THE FAR WEST...WITH ANOTHER (POSSIBLY STRONGER) SEWD-MOVING SFC BOUNDARY APPROACHING. THIS SHOULD MEAN SOMEWHAT DIMINISHED CHANCES OF SHOWERS/TSTMS POPPING UP UNTIL WED...WHEN THE PARENT SHRTWV WILL BE CLOSER TO THE REGION. SCATTERED ACTIVITY IS EXPECTED AGAIN BY THEN. RATHER WEAK FLOW ALOFT WILL NOT NECESSARILY BE CONDUCIVE TO SEVERE WEATHER IN OUR REGION. TEMPS/DEWPOINTS IN ANY ONE AREA ARE NOT EXPECTED TO CHANGE MUCH DURING THE EXTENDED PERIOD...OUTSIDE OF TSTM ACTIVITY. LOWER TO MIDDLE 90S WILL PREVAIL...WITH DEWPOINTS IN THE LOWER 70S FOR ALMOST THE ENTIRE TIME...YIELDING THE AFOREMENTIONED HEAT INDICES. && .AVIATION... ISSUED AT 1140 PM CDT WED JUL 22 2015 ISOLATED SHOWERS ARE POSSIBLE AT MAINLY AT KCGI/KPAH THROUGH 13Z. MVFR VSBYS ARE POSSIBLE MAINLY AT KCGI/KPAH BETWEEN 09Z-13Z. VFR CIGS EXPECTED OVERALL AT ALL TAF SITES. WINDS OVERNIGHT WILL BE LIGHT FROM THE NORTHEAST TO EAST, INCREASING TO AROUND 5 KTS AFTER 13Z. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...CN LONG TERM...DB AVIATION...RST
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1236 AM CDT Thu Jul 23 2015 .MESOSCALE DISCUSSION... Issued at 1042 PM CDT WED JUL 22 2015 There appears to be a growing number of signals for localized heavy rainfall/flooding potential from late tonight into Thursday morning. A surface frontal boundary will remain draped across southern Missouri and will move very little through at least early Thursday morning. Meanwhile, a developing low level jet stream will induce increased isentropic upglide overnight from part of eastern Kansas across southwestern Missouri into northern Arkansas. This is also in line with a slug of stronger 850 mb theta-e advection and moisture transport. This should result in scattered to possibly numerous showers and thunderstorms developing as we get into later tonight and early Thursday morning. What is somewhat concerning is the high moisture content of the atmosphere. The 00Z KSGF sounding indicated about 2.00" of precipitable water content. This along with high freezing levels will result in very efficient rainfall rates. Additionally, there appears to be potential for training bands of convection as mean wind fields are fairly aligned with a low level theta-e and overall CAPE gradient. Recent trends in models such as the 00Z NAM and GFS as well as recent HRRR runs seem to back the potential for locally heavy rainfall. We updated the Hazardous Weather Outlook to cover these concerns a bit earlier this evening. One other final note was the addition of fog to the forecast. While we are not looking at widespread dense fog, any areas that experience appreciable breaks in cloud cover should see at least patchy fog. This will especially be true along and north of that front. && .SHORT TERM...(This Evening through Thursday) Issued at 328 PM CDT WED JUL 22 2015 Scattered showers and few storms will continue to occur mainly south of Highway 60 into this evening as weak upper level disturbance tracks east across Kansas and a front remains stalled near the Missouri Arkansas border. Instability has increased across southern Missouri with the heating of the day, but with weak deep layer shear and not very steep low level steep rates the will keep the severe risk very low with this activity. These storms will weaken with the loss of day time heating later this evening. Tonight another upper level shortwave will move out of the central Plains and across the region and could generate additional scattered showers and storms overnight. Deep layer shear will increase with the shortwave, but with the loss of day time heating and being north of the stalled front instability will be limited and not expected much in the way of severe weather overnight. Thursday looks mainly dry as the area will be behind the upper level disturbance. The front will begin to lift to the north on Thursday resulting in temperatures ranging from the middle 80s across central Missouri to around the 90 degree mark across southeastern Kansas Thursday afternoon. .LONG TERM...(Thursday Night through Wednesday) Issued at 328 PM CDT WED JUL 22 2015 The warm front will continue to lift northeast through the region Thursday night into early Friday. Scattered storms will be possible along and north of the front Thursday night, mainly across the eastern Ozarks. An upper level ridge will begin to slide east into the area on Friday and then over the area on Saturday. Highs in the lower to middle 90s are expected west of Highway 65 on Friday afternoon and then across the entire area on Saturday. Heat Index values of 100 to 108 are expected Friday and Saturday afternoons. An upper level disturbance will push the ridge back slightly to the west Saturday night and Sunday. Shower and thunderstorms will be possible across the eastern Ozarks as a result but the better chances should remain north and east of the area as the ridge does not appear to retreat to far to the west. The ridge will build right back over the region next Monday and Tuesday with highs in the lower to middle 90s occurring each afternoon. Medium range models indicate the ridge will flatten allow a front to approach from the north during the middle of next week, bringing chances for showers and thunderstorms to the region. && .AVIATION...(For the 06Z TAFS through 06Z Thursday Night) Issued at 1222 AM CDT THU JUL 23 2015 Scattered showers and thunderstorms will develop near a frontal boundary across southern Missouri through Thursday morning. MVFR and local IFR conditions can be expected with this activity. Additionally, patchy areas of IFR fog will also develop. LIFR visibilities will continue at times around KBBG. Conditions will then improve by Thursday afternoon with VFR conditions then expected into Thursday evening. Winds will remain light through the period. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ MESOSCALE...Schaumann SHORT TERM...Wise LONG TERM...Wise AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS HASTINGS NE
438 AM CDT THU JUL 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 417 AM CDT THU JUL 23 2015 ALOFT: THE PATTERN THAT HAS BEEN IN PLACE SINCE THE BEGINNING OF THE MONTH REMAINS LOCKED IN. SUBTROPICAL HIGH PRES WAS OVER TX WITH TROFS OVER THE ERN AND WRN USA. THERE WILL BE NO CHANGE THRU TONIGHT. SYNOPTIC FORCING WILL BE NIL. SURFACE: HIGH PRES WAS OVER THE MIDWEST AND OH VALLEY AND WILL REMAIN PARKED THERE THRU TONIGHT. LOW PRES WAS ADVANCING THRU CNTRL CANADA THIS MORNING. ITS COOL FRONT EXTENDED SW INTO THE NRN ROCKIES...BISECTING MT/ID. THIS FRONT WILL MOVE INTO THE NRN PLAINS TODAY...WITH ITS TAIL END ENTERING NRN/WRN NEB TONIGHT. A WEAK/SUBTLE SHORTWAVE TROF /BEST SEEN AT 700 MB/ APPEARS TO BE RESPONSIBLE FOR THE FEW SHWRS/TSTMS THAT HAVE BEEN ON-GOING THRU THE NIGHT ALONG THE SD/NEB BORDER. AN ISOLATED CELL OR TWO HAS TRIED TO DEVELOP AT TIMES N-NW OF ODX. VARIOUS MODELS AND THE HI- RES RAP ENSEMBLE SUGGEST THESE SHWRS/TSTMS COULD INCREASE IN COVERAGE AND BUILD DOWN INTO AREAS E OF HWY 281. IR SATELLITE DOES SHOW A N-S ORIENTED BAND OF CLOUDS HAS DEVELOPED AND BVN/AUH/JYR ALL NOW HAVE CIGS AROUND 6-7K FT. TODAY: COULD SEE AN ISOLATED SHWR/TSTM EARLY N AND E OF THE TRI- CITIES. OTHERWISE...SUNNY. NEAR NORMAL TEMPS. ISOLATED TSTMS SHOULD DEVELOP FROM THE SAND HILLS SW TO NEAR IML IN THE 4-6 PM TIME FRAME. THESE COULD EVENTUALLY THREATEN AREAS FROM ODX-LXN. TONIGHT: P-M/CLOUDY AS CLOUD DEBRIS FROM TSTMS OVERTAKES THE AREA. INDICATIONS FROM THE 03Z SREF AND VARIOUS MODELS ARE THAT SOME OF THE TSTM ACTIVITY THAT DEVELOPS LATE THIS AFTERNOON COULD LINGER INTO THE NIGHT...SUSTAINED BY A 30 KT LOW-LVL JET. THE 06Z NAM WAS NOT NEARLY AS AGGRESSIVE WITH ITS QPF AS THE 00Z RUN. STORMS THAT DEVELOP LATE THIS AFTERNOON WILL BE FAIRLY SLOW MOVERS...E AROUND 20 KTS. CAN`T RULE OUT SEVERE WX. MLCAPE WILL BE SUBSTANTIAL (3000-4000 J/KG) WITH TEMPS AROUND 90F...DWPTS IN THE LOW 70S AND MID-LVL LAPSE RATES OF 7 DEG C/KM. THE OVERALL LACK OF FORCING WILL KEEP STORMS FEW AND FAR BETWEEN...BUT WHATEVER DOES DEVELOP COULD BE SEVERE FOR A TIME PROBABLY PRIOR TO 10 PM. DEEP LAYER SHEAR 40-45 KTS. SUPERCELL STORM STRUCTURES WILL BE POSSIBLE. SUPERCELL STORM MOTION COULD EVEN BE SLOWER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 437 AM CDT THU JUL 23 2015 FRIDAY WILL BE THE HOTTEST DAY OF THE WEEK AND WE WILL BE FLIRTING WITH HEAT ADVISORY CRITERIA FOR MOST LOCATIONS SOUTH AND EAST OF THE TRI-CITIES. THE WEEKEND WILL REMAIN HOT WITH HIGHS A FEW DEGREES ABOVE NORMAL RIGHT INTO MONDAY. WE COULD COOL BACK A COUPLE DEGREES TO AROUND NORMAL TEMPERATURES BY TUESDAY AND WEDNESDAY. THERE WILL BE SEVERAL CHANCES FOR THUNDERSTORMS IN THE WEEK AHEAD WITH ONE OF THE BETTER CHANCES BEING FRIDAY NIGHT. FRIDAY...A LARGE UPPER LEVEL RIDGE WILL BE CENTERED OVER NORTH TEXAS AND A WEAK VORT MAX WILL BE SLIDING EAST ACROSS NEBRASKA ALONG THE NORTHERN PERIPHERY OF THIS UPPER HIGH BY LATE IN THE DAY. THERE WILL BE A WEAK SFC LOW/TROUGH AXIS LOCATED FROM SOUTHWEST TO NORTHEAST ACROSS OUR FORECAST AREA BY AFTERNOON/EARLY EVENING. EXPECT A LIGHT NORTHEAST WIND ACROSS OUR NORTHERN ZONES NORTH OF THIS BOUNDARY AND A SOUTHERLY WIND OVER OUR KANSAS COUNTIES AND FAR SOUTHEASTERN NEBRASKA COUNTIES SOUTH OF THIS SFC TROUGH. THERE WILL BE A LOT OF LOW LEVEL MOISTURE POOLING ALONG THE SFC BOUNDARY...ESPECIALLY GIVEN THE TIME OF YEAR WITH A SIGNIFICANT AMOUNT OF CORN EVAPOTRANSPIRATION. SFC DEWPOINTS WILL LIKELY BE IN THE MID TO UPPER 70S WITH A FEW SITES POSSIBLY EVEN SEEING AN 80F DEWPOINT. THIS WILL RESULT IN VERY HIGH INSTABILITY. WIND SHEAR IS RATHER MARGINAL...ESPECIALLY AS YOU HEAD SOUTH INTO KANSAS CLOSER TO THE UPPER HIGH. HOWEVER...THERE IS A PRETTY GOOD UPPER LEVEL JET FOR THIS TIME OF YEAR AT 50 TO 55 KTS OVER SOME OF OUR NEBRASKA COUNTIES. EXPECT THUNDERSTORMS WILL FORM ALONG THE SFC TROUGH LATE IN THE AFTERNOON WITH MAX HEATING. THE LOW LEVEL JET WILL STRENGTHEN AFTER SUNSET WITH THE NOSE OF THE LOW LEVEL JET SUPPORTING STRONG THUNDERSTORMS WELL INTO THE EVENING ACROSS PORTIONS OF OUR FORECAST AREA. SEVERE WIND AND HAIL WILL BE POSSIBLE LATE FRIDAY AFTERNOON INTO THE EVENING HOURS. GIVEN THE HIGH DEWPOINTS AND HIGH TEMPERATURES...HEAT INDEX VALUES STAND A DECENT CHANCE OF REACHING OUR 105F ADVISORY THRESHOLD RIGHT ALONG AND SOUTH OF THE TROUGH AXIS FRIDAY AFTERNOON. A HEAT ADVISORY WILL LIKELY BE NEEDED ACROSS PORTIONS OF OUR FORECAST AREA IF THIS TREND CONTINUES. SATURDAY AND SUNDAY...EXPECT OLD OUTFLOW BOUNDARIES ACROSS THE FORECAST AREA FROM FRIDAY NIGHT AND SATURDAY NIGHT THUNDERSTORMS WILL BE A FOCUSING MECHANISM FOR NEW AFTERNOON/EVENING THUNDERSTORMS BOTH DAYS THIS WEEKEND. THE LOW LEVEL JET WILL AGAIN BE WELL POSITIONED FOR DEVELOPING/MAINTAINING THUNDERSTORMS DURING THE EVENING AND OVERNIGHT HOURS BOTH FRIDAY NIGHT AND SATURDAY NIGHT. THEREFORE...EXPECT AT LEAST SEVERAL THUNDERSTORMS IN THE AREA PRIMARILY DURING THE LATE AFTERNOON/EVENING/OVERNIGHT HOURS. THUNDERSTORM CHANCES WILL BE HIGHEST ON SATURDAY...BUT MAY NEED TO INCREASE CHANCES FOR THE SUNDAY EVENING TIME FRAME BASED ON THE LATEST 00Z RUN OF THE ECMWF. TEMPERATURES WILL REMAIN HOT ESPECIALLY AS YOU HEAD SOUTH INTO KANSAS AND NEARER THAT BIG UPPER RIDGE THAT WILL CONTINUE TO BE PARKED OUT OVER TEXAS. MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE WHEN IT COMES TO RAIN CHANCES IS FAIRLY LOW. FORECAST MODELS ARE ALL OVER THE PLACE ON IF WE WILL OR WILL NOT SEE SOME RAIN DURING THIS OUTER PERIOD. GENERAL FEELING IS THAT WE WILL CONTINUE TO SEE RAIN CHANCES ACROSS OUR FORECAST AREA AS UPPER TROUGHS SWING THROUGH RIDING JUST NORTH OF THE SOUTHERN PLAINS UPPER RIDGE...WHICH SHOULD PLACE THUNDERSTORMS IN OUR GENERAL AREA. HIGH TEMPERATURES THROUGH THE PERIOD REFLECT THE SUPERBLEND OF FORECAST MODELS...WHICH WOULD BE RIGHT AROUND NORMAL TO A FEW DEGREES ABOVE NORMAL ON MONDAY AND THEN NEAR NORMAL TO A FEW DEGREES BELOW NORMAL BY TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THU NIGHT) ISSUED AT 1227 AM CDT THU JUL 23 2015 SIGNIFICANT AVIATION WX: NONE REST OF TONIGHT: VFR AND ESSENTIALLY SKC. SE WINDS 10 KTS OR LESS. CONFIDENCE: HIGH THU: VFR WITH JUST A FEW PATCHES OF ALTOCU AROUND 13K FT DRIFTING THRU. SE-S WINDS 10-15 KTS. CAN`T RULE OUT A GUST OR TWO CLOSE TO 20 KTS. CONFIDENCE: HIGH THU THRU 06Z: VFR WITH MULTI-LAYERED CLOUDS INVADING...BLOW-OFF FROM UPSTREAM TSTMS. THERE IS A CHANCE TSTMS COULD MOVE THRU THE TERMINALS AFTER 06Z. SE WINDS UNDER 10 KTS. CONFIDENCE: MEDIUM && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...HALBLAUB LONG TERM...WESELY AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
417 AM CDT THU JUL 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 417 AM CDT THU JUL 23 2015 ALOFT: THE PATTERN THAT HAS BEEN IN PLACE SINCE THE BEGINNING OF THE MONTH REMAINS LOCKED IN. SUBTROPICAL HIGH PRES WAS OVER TX WITH TROFS OVER THE ERN AND WRN USA. THERE WILL BE NO CHANGE THRU TONIGHT. SYNOPTIC FORCING WILL BE NIL. SURFACE: HIGH PRES WAS OVER THE MIDWEST AND OH VALLEY AND WILL REMAIN PARKED THERE THRU TONIGHT. LOW PRES WAS ADVANCING THRU CNTRL CANADA THIS MORNING. ITS COOL FRONT EXTENDED SW INTO THE NRN ROCKIES...BISECTING MT/ID. THIS FRONT WILL MOVE INTO THE NRN PLAINS TODAY...WITH ITS TAIL END ENTERING NRN/WRN NEB TONIGHT. A WEAK/SUBTLE SHORTWAVE TROF /BEST SEEN AT 700 MB/ APPEARS TO BE RESPONSIBLE FOR THE FEW SHWRS/TSTMS THAT HAVE BEEN ON-GOING THRU THE NIGHT ALONG THE SD/NEB BORDER. AN ISOLATED CELL OR TWO HAS TRIED TO DEVELOP AT TIMES N-NW OF ODX. VARIOUS MODELS AND THE HI- RES RAP ENSEMBLE SUGGEST THESE SHWRS/TSTMS COULD INCREASE IN COVERAGE AND BUILD DOWN INTO AREAS E OF HWY 281. IR SATELLITE DOES SHOW A N-S ORIENTED BAND OF CLOUDS HAS DEVELOPED AND BVN/AUH/JYR ALL NOW HAVE CIGS AROUND 6-7K FT. TODAY: COULD SEE AN ISOLATED SHWR/TSTM EARLY N AND E OF THE TRI- CITIES. OTHERWISE...SUNNY. NEAR NORMAL TEMPS. ISOLATED TSTMS SHOULD DEVELOP FROM THE SAND HILLS SW TO NEAR IML IN THE 4-6 PM TIME FRAME. THESE COULD EVENTUALLY THREATEN AREAS FROM ODX-LXN. TONIGHT: P-M/CLOUDY AS CLOUD DEBRIS FROM TSTMS OVERTAKES THE AREA. INDICATIONS FROM THE 03Z SREF AND VARIOUS MODELS ARE THAT SOME OF THE TSTM ACTIVITY THAT DEVELOPS LATE THIS AFTERNOON COULD LINGER INTO THE NIGHT...SUSTAINED BY A 30 KT LOW-LVL JET. THE 06Z NAM WAS NOT NEARLY AS AGGRESSIVE WITH ITS QPF AS THE 00Z RUN. STORMS THAT DEVELOP LATE THIS AFTERNOON WILL BE FAIRLY SLOW MOVERS...E AROUND 20 KTS. CAN`T RULE OUT SEVERE WX. MLCAPE WILL BE SUBSTANTIAL (3000-4000 J/KG) WITH TEMPS AROUND 90F...DWPTS IN THE LOW 70S AND MID-LVL LAPSE RATES OF 7 DEG C/KM. THE OVERALL LACK OF FORCING WILL KEEP STORMS FEW AND FAR BETWEEN...BUT WHATEVER DOES DEVELOP COULD BE SEVERE FOR A TIME PROBABLY PRIOR TO 10 PM. DEEP LAYER SHEAR 40-45 KTS. SUPERCELL STORM STRUCTURES WILL BE POSSIBLE. SUPERCELL STORM MOTION COULD EVEN BE SLOWER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 417 AM CDT THU JUL 23 2015 THIS SECTION WILL UPDATE SHORTLY. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THU NIGHT) ISSUED AT 1227 AM CDT THU JUL 23 2015 SIGNIFICANT AVIATION WX: NONE REST OF TONIGHT: VFR AND ESSENTIALLY SKC. SE WINDS 10 KTS OR LESS. CONFIDENCE: HIGH THU: VFR WITH JUST A FEW PATCHES OF ALTOCU AROUND 13K FT DRIFTING THRU. SE-S WINDS 10-15 KTS. CAN`T RULE OUT A GUST OR TWO CLOSE TO 20 KTS. CONFIDENCE: HIGH THU THRU 06Z: VFR WITH MULTI-LAYERED CLOUDS INVADING...BLOW-OFF FROM UPSTREAM TSTMS. THERE IS A CHANCE TSTMS COULD MOVE THRU THE TERMINALS AFTER 06Z. SE WINDS UNDER 10 KTS. CONFIDENCE: MEDIUM && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...HALBLAUB LONG TERM...WESELY AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
338 AM EDT THU JUL 23 2015 .SYNOPSIS... LOW PRESSURE OVER NORTHERN SOUTH CAROLINA WILL MOVE EAST ALONG A STALLED FRONT TODAY AND OFF THE COAST TONIGHT. THIS LOW WILL PUSH THE FRONT INTO GEORGIA FOR THIS WEEKEND. HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH...WITH A DRYING TREND EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM THURSDAY...LOW PRESSURE CENTERED OVER THE SC SANDHILLS WILL MOVE EASTWARD ALONG A STATIONARY FRONT TODAY...EXITING INTO THE ATLANTIC OCEAN TONIGHT. MODELS ARE ALMOST UNANIMOUS IN THEIR DEPICTION OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING WITHIN A REGION OF LOW-LEVEL CONVERGENCE AND LARGE INSTABILITY OVER SOUTHERN NORTH CAROLINA JUST NORTH OF THE STATIONARY FRONT LATE THIS MORNING. SURFACE CAPE IS PREDICTED TO GROW AS LARGE AS 3000 J/KG WITH LIFTED INDICES TO -6. 700 MB WINDS INCREASING TO 25 KT SHOULD INCREASE BULK SHEAR VALUES JUST ENOUGH TO PRODUCE ORGANIZED MULTICELLULAR STORMS TODAY...WITH COLD POOL EFFECTS LIKELY PUSHING THE CLUSTER SOUTHEASTWARD ACROSS THE CAPE FEAR AREA EARLY THIS AFTERNOON AND INTO NORTHEASTERLY SOUTH CAROLINA BY MID TO LATE AFTERNOON. IMPACTS FROM THESE STORMS COULD BE CONSIDERABLE. COMPUTED EQUILIBRIUM PARCEL HEIGHTS NEAR 50000 FT AND LOTS OF INSTABILITY ABOVE THE -20C LEVEL INDICATES THESE STORMS COULD BE ENORMOUS LIGHTNING PRODUCERS WITH PLENTY OF ICE/GRAUPEL GENERATION ALOFT. ALTHOUGH NO DRY LAYERS ARE EVIDENT IN FORECAST SOUNDINGS PRECIPITATION LOADING RESULTING FROM SUCH VIGOROUS CONVECTION SHOULD PRODUCE GUSTY WINDS...PARTICULARLY AS THE STORMS ARE SHOWN IN THE HIGH RESOLUTION WRF-NMM...WRF-ARW...AND HRRR MODELS TO FORM A LARGE MASSED OUTFLOW PUSHING SOUTHEASTWARD TO THE COAST. WITH THE SYNOPTIC FRONT STALLED ACROSS THE AREA AND ANTICIPATED BOUNDARY COLLISIONS THE STORMS SHOULD ALSO BE HEAVY RAIN MAKERS WITH LOCALIZED FLOODING POSSIBLE. FORECAST RAIN CHANCES HAVE BEEN INCREASED TO 80 PERCENT ACROSS SE NORTH CAROLINA...FOCUSED ON THE NOON-4 PM TIMEFRAME. CONVECTION SHOULD TAKE SEVERAL ADDITIONAL HOURS TO PROPAGATE SOUTHWARD AND AFFECT NE SOUTH CAROLINA WHICH WILL BE LOCATED SOUTH OF THE STATIONARY FRONT. THIS MEANS SEVERAL ADDITIONAL HOURS OF HOT SUNSHINE...AND TEMPERATURES HERE WILL RISE INTO THE MID TO UPPER 90S. FORECAST HEAT INDICES ARE JUST BELOW 105-DEGREE HEAT ADVISORY CRITERIA ACROSS GEORGETOWN...WILLIAMSBURG AND SOUTHERN FLORENCE COUNTIES. AN UPPER LEVEL DISTURBANCE CURRENTLY PRODUCING THUNDERSTORMS OVER CENTRAL TENNESSEE WILL REACH THE EASTERN CAROLINAS THIS EVENING. THIS COULD HELP CONVECTIVE ACTIVITY TO PERSIST INTO THE EVENING HOURS EVEN AFTER THE ATMOSPHERE PRETTY MUCH OVERTURNS DURING THE AFTERNOON. THE LOW WILL SCOOT EASTWARD ALONG THE FRONT OFFSHORE AFTER MIDNIGHT WITH SURFACE WINDS TURNING NORTHWESTERLY...QUITE AN ODD DIRECTION FOR THE CAROLINAS IN THE MIDDLE OF SUMMER. THIS IS THE THIRD COLD FRONTAL PASSAGE OF JULY! && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LATEST MODELS SHOW LOW JUST OFF THE CAPE FEAR COAST FRI MORNING. EXPECT BEST CONVECTION OVER THE COASTAL WATERS WITH MOST AREAS SEEING A DEEP FLOW OF DRIER AIR ADVECTING IN FROM THE NORTH. MID TO UPPER TROUGH WILL PUSH LOW PRESSURE ALONG LINGERING BOUNDARY SOUTH AND EAST OF AREA THROUGH THE DAY...BUT PLENTY OF RESIDUAL LOW LEVEL MOISTURE FROM PREVIOUS DAYS CONVECTION WILL SLOW CLEARING AND COMBINE WITH CONVERGENCE ASSOCIATED WITH LOW AND OTHER LOCALIZED BOUNDARIES SUCH AS THE SEA BREEZE TO PRODUCE SOME SHWRS/TSTMS. LOOKS LIKE BEST CHC WILL MOVE SOUTH THROUGH THE DAY AS HIGH PRESSURE BEGINS TO BUILD DOWN FROM THE NORTH BUT MAY NOT BE FAST ENOUGH TO ELIMINATE POPS FROM FORECAST. NAM SHOWS MAIN FOCUS OF CONVECTION ALONG COASTAL SOUTH CAROLINA WHERE BEST CONVERGENCE SHOULD BE AS WE DEVELOP A N-NE FLOW. MAY SEE ENOUGH SUBSIDENCE AND DRY AIR THROUGH THE MID TO UPPER LEVELS BY LATE FRI TO ALLOW FOR ONLY A DECENT STRATOCU FIELD OVER NC. PCP WATER VALUES OVER 2 INCHES EARLY FRI MORNING WILL DROP DOWN CLOSE TO AN INCH BY SAT MORNING. LINGERING CLOUDS AND PCP WILL KEEP TEMPS IN THE 80S MOST OF THE DAY BUT PLACES THAT SEE SOME SUN MAKE AN APPEARANCE WILL REACH CLOSE TO 90. BY LATE FRI INTO FRI NIGHT...PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID TO UPPER LEVELS WILL REACH DOWN OVER THE FORECAST AREA AS DRY HIGH PRESSURE AT THE SFC NOSES DOWN FROM THE NORTH. WILL SHOW CLEARING AT THIS TIME AND WILL KEEP PCP OUT OF FORECAST THROUGH THE REMAINDER OF THE WEEKEND. PLENTY OF BRIGHT JULY SUNSHINE WILL DRIVE TEMPS UP NEAR NORMAL...CLOSE TO 90 BUT SFC DEWPOINT TEMPS WILL BE RUNNING IN THE LOW TO MID 60S MOST PLACES WHICH WILL MAKE FOR A MUCH MORE REFRESHING DAY THAN PREVIOUS ONES. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM THURSDAY...CENTER OF HIGH PRESSURE NOSING DOWN FROM THE NORTH WILL SHIFT OFF THE MID ATLANTIC COAST ALLOWING WINDS TO COME AROUND TO A MORE ON SHORE NE TO E FLOW. WEAK HIGH PRESSURE WILL CONTINUE TO REACH DOWN INTO THE CAROLINAS THROUGH MID WEEK AS LEE SIDE TROUGH BECOMES MORE PRONOUNCED. RIDGING IN THE MID TO UPPER LEVELS OVER THE MID WEST WILL BUILD EASTWARD OVER THE WEEKEND...BUT AS IT BECOMES MORE AMPLIFIES UP THROUGH THE UPPER MIDWEST BY TUES...A DEEPER NW FLOW ALOFT WILL ALLOW SOME CLOUDS AND SHORTWAVE ENERGY TO SNEAK INTO AREA BUT RIDGE WILL BUILD BACK EAST AND UP THE EAST COAST THROUGH MID WEEK AND THEREFORE MAY INTRODUCE INCREASED CLOUDS AND SHWRS FOR TUES/WED TIME FRAME BUT OVERALL SHWR ACTIVITY SHOULD REMAIN MORE ISOLATED HEADING INTO MID WEEK AS RIDGE BUILDS BACK IN. THE ON SHORE FLOW DEVELOPING THROUGH THE PERIOD WILL AID IN BRINGING DEWPOINT TEMPS BACK UP CLOSER TO 70 OR SO...HELPING TO INCREASE AFTN CU AND CHC OF SOME CONVECTIVE DEVELOPMENT. TEMPS WILL BASICALLY REMAIN AROUND CLIMO. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 06Z...LOOKS LIKE THERE WILL BE LITTLE BEFORE SUNRISE. THE WEAK MCS WEST OF THE AREA DID NOT MAKE IT. WITH LITTLE IN CONVECTIVE DEBRIS...TEMPO MVFR FOG IS A GOOD BET AFTER 08Z. THE FRONT WAVES BACK TO THE NORTH AROUND DAYBREAK WITH MOISTURE INCREASING LATER IN THE MORNING. TIMING OF THE CONVECTION WILL BE AN ISSUE...BUT IT IS SAFE TO SAY THAT SHOWERS AND STORMS WILL BE AROUND TODAY...POSSIBLY NUMEROUS AS DEEP MOISTURE MOVES BACK OVER THE REGION. LOW PRESSURE FORMING ALONG THE FRONT SHOULD ENHANCE PRECIPITATION. THERE SHOULD BE MINIMAL CONVECTIVE INHIBITION...A CHANGE FROM THE PREVIOUS WEEK...WITH CONVECTION EXPECTED TO BEGIN WITH ONLY MINIMAL HEATING...BY MIDDAY. SOME BRIEF IFR CONDITIONS ARE LIKELY IN THE HEAVIEST ACTIVITY. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM ISOLATED CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM THURSDAY...LOW PRESSURE CENTERED OVER THE SOUTH CAROLINA SANDHILLS WILL MOVE EASTWARD TODAY ALONG A WEAK STATIONARY FRONT. THIS FRONT CURRENTLY SITS JUST NORTH OF CAPE FEAR AND IS OUTLINED BY A SHIFT IN WIND DIRECTIONS FROM SOUTHERLY ALONG THE SC COAST TO SOUTHEASTERLY FROM WRIGHTSVILLE BEACH AND SURF CITY TO THE OUTER BANKS. AS INLAND AREAS HEAT UP QUICKLY THIS MORNING ATMOSPHERIC CONDITIONS ARE STRONGLY SUPPORTIVE OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING ACROSS SOUTHERN NORTH CAROLINA...DROPPING SOUTHEASTWARD AND AFFECTING THE COASTAL WATERS DURING THE AFTERNOON. THESE STORMS WILL LIKELY CONTAIN LARGE AMOUNTS OF LIGHTNING AND SUBSTANTIAL VISIBILITY RESTRICTIONS IN HEAVY RAIN. SEVERAL OF THE HIGH- RESOLUTION MODELS INDICATE THE POTENTIAL FOR A STRONG GUST FRONT AT THE LEADING EDGE OF THE STORMS WHICH MAY PROMPT SPECIAL MARINE WARNINGS THIS AFTERNOON. MARINERS IN THE CAPE FEAR AREA SHOULD EXPECT THE LARGEST IMPACT FROM THESE STORMS BETWEEN 1-3 PM...WITH THE GRAND STAND AND GEORGETOWN AREAS A COUPLE HOURS LATER. LATE TONIGHT AS THE LOW SHIFTS EASTWARD ALONG THE FRONT AND ENTERS THE ATLANTIC OCEAN SURFACE WINDS WILL SHIFT NORTHWESTERLY AND MAY INCREASE TO 10-15 KT LATE. OUTSIDE OF THUNDERSTORMS SEAS SHOULD AVERAGE 2 FEET TODAY...AND 2-3 FEET TONIGHT. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LOW PRESSURE ALONG LINGERING BOUNDARY WILL SLIP FARTHER SOUTH THROUGH THE DAY ON FRIDAY. NORTHEAST FLOW WILL DEVELOP BEHIND THIS BOUNDARY AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH THROUGH THE WEEKEND. EXPECT WINDS TO REMAIN BELOW 15 KTS ACROSS MOST OF THE WATERS...BUT THERE SHOULD BE SOME PERIODS OF HIGHER WAVES...UP CLOSER TO 20 KTS. THE WINDS WILL BEGIN TO VEER AROUND FROM THE NE TO E. THE PERSISTENT STRONGER NE TO E ON SHORE FLOW WILL PRODUCE SEAS UP TO 3 TO 5 FT...ESPECIALLY THROUGH SAT NIGHT. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 330 AM...HIGH PRESSURE EXTENDING DOWN INTO THE CAROLINAS FROM THE NORTHEAST WILL MOVE FARTHER EAST THROUGH THE PERIOD...ALLOWING WINDS TO LIGHTEN AND VEER TO THE EAST. THE WINDS SHOULD DECREASE TO 10 KTS OR LESS MOST OF THE TIME...BUT SEA BREEZE EACH AFTN WILL ACT TO ENHANCE OVERALL ON SHORE FLOW. EXPECT SEAS TO BE COMING DOWN AS WINDS LIGHTEN HEADING THROUGH LATE SUNDAY INTO MONDAY. THEREFORE SEAS UP TO 3 TO 5 FT EARLY SUNDAY SHOULD DROP TO 2 TO 4 FT SUN NIGHT. AS SHORTER PERIOD WINDWAVE DIMINISHES THROUGH MONDAY AND WNA CONTINUES TO SHOW A LONGER PERIOD UP TO 11 SEC WAVE MIXING IN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...RGZ LONG TERM...RGZ AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1135 PM CDT WED JUL 22 2015 .UPDATE... ISSUED AT 1135 PM CDT WED JUL 22 2015 A COUPLE OF CELLS HAVE FORMED UP AROUND KBDE BUT HAVE JUST ABOUT MOVED OUT OF THE AREA. LATEST RAP HINTS AT SOME ACTIVITY UP IN THIS AREA OVERNIGHT...BUT NOT CONVINCED MUCH WILL HAPPEN AT THIS POINT. THEREFORE WILL MAINTAIN A DRY FORECAST FOR NOW. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 350 PM CDT WED JUL 22 2015 UPPER LEVEL RIDGE EXTENDED FROM THE HIGH PLAINS OF WY TO NORTHERN MAN. UPPER LEVEL RIDGE WILL BUILD AND SHIFT EAST TONIGHT AND THU. WATER VAPOR LOOP INDICATED A WEAK SHORT WAVE OVER WESTERN ND AND WAS MOVING EAST ABOUT 30 KNOTS. MD LEVEL LAPSE RATES WERE MODEST OVER ALL BUT THE NORTHEAST ZONES THIS AFTERNOON. LOW THREAT FOR PRECIP OVER AREA WITH MODEST LAPSE RATES. MODEST LAPSE RATE AREA TO SHIFT NORTHEAST OVERNIGHT AND WILL KEEP LOW POPS THERE. CAPES FORECAST AROUND 2000-2500 J/KG AND CIN WERE UNDER 50 J/KG FOR THU AFTERNOON/EVENING. CONVECTIVE TEMPS WERE RATHER HIGH WITH A WEAK INVERSION AROUND 750 HPA. WARM 700 HPA TEMPS EXPECTED TO CAP ATMOSPHERE PRE-FRONTALLY. SURFACE TROUGH TO MOVE INTO THE AREA LATE AFTERNOON/EVENING THU SHOULD TRIGGER THUNDERSTORMS. NEXT CHANCE FOR DIURNALLY DRIVEN THUNDERSTORMS WOULD BE SAT AFTERNOON AND EVENING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 350 PM CDT WED JUL 22 2015 (SUNDAY-WEDNESDAY)...THERE IS A RATHER CONSISTENT SIGNAL IN ALL EXTENDED GUIDANCE INDICATING A STRONG SYSTEM ACROSS SOUTHERN CANADA THAT WILL SEND A COLD FRONT THROUGH THE REGION ON MONDAY. ALTHOUGH CONFIDENCE IN DETAILS WILL REMAIN LOW...THERE DOES APPEAR A HIGHER LIKELIHOOD FOR SEVERE THUNDERSTORMS WITH THIS FROPA. ABOVE NORMAL TEMPERATURES TO BEGIN THE PERIOD WILL TRANSITION TO NEAR NORMAL VALUES BY MID-WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1135 PM CDT WED JUL 22 2015 ALL TAF SITES ARE SEEING STEADY SSE WINDS NOW WITH GENERALLY CLEAR SKIES. WARM MID LEVEL TEMPS BUILD INTO THE AREA DURING THE DAY THU SO NOT EXPECTING MUCH OTHER THAN A BIT OF CIRRUS. COLD FRONT EXPECTED TO MOVE INTO THE KDVL REGION AROUND 00Z FRI...WHICH WILL START SOME TSTMS MOVING EASTWARD. THREW IN A MENTION AT KGFK/KFAR AROUND 05Z FRI...BUT THIS IS JUST A BALLPARK TIME AT THIS POINT. COULD BE A LITTLE SOONER OR LATER. NOT EXPECTING ANY TSTMS AT KTVF/KBJI UNTIL AFTER THIS TAF PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...GODON SHORT TERM...HOPPES LONG TERM...TG AVIATION...GODON
AREA FORECAST DISCUSSION
NWS NORMAN OK
435 AM CDT THU JUL 23 2015 .DISCUSSION... THE STORMS THIS MORNING SHOULD BE ONE LAST HOORAH FOR CONVECTION FOR A FEW DAYS. STORMS WILL AT LEAST PERSIST ACROSS NORTH CENTRAL OKLAHOMA WHILE THE HRRR AND RAP SHOW THE CHANCE OF STORMS DEVELOPING FARTHER SOUTH AS WELL. DID EXPAND THE SLIGHT CHANCE POPS FARTHER SOUTH GIVEN THE HRRR AND RAP SIGNAL. EXPECT STORMS TO HAVE MOVED EAST OF THE AREA AND/OR DISSIPATED BY EARLY THIS AFTERNOON. FOCUS REMAINS ON HEAT OVER THE NEXT FEW DAYS. GFS INITIALIZED DEWPOINTS WAY TOO LOW THIS MORNING OVER THE AREA SO BLENDED WENT WELL ABOVE BLENDED INITIALIZATION FOR DEWPOINTS. TEMPERATURES WILL BE HIGH THIS AFTERNOON ALTHOUGH NOT CRAZY HIGH... BUT DEWPOINTS EXPECTED TO REMAIN IN THE LOW TO MID 70S WILL BRING HEAT INDEX VALUES OVER 110 IN SOME AREAS. HAVE ISSUED A HEAT ADVISORY FOR THE NORTH CENTRAL... CENTRAL AND SOUTHEAST FOR THIS AFTERNOON. HEAT WILL CONTINUE TO BE THE PRIMARY WEATHER STORY OVER THE NEXT FEW DAYS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 96 75 98 75 / 20 0 0 0 HOBART OK 100 76 102 75 / 10 10 0 0 WICHITA FALLS TX 99 77 100 77 / 10 10 0 0 GAGE OK 99 73 100 73 / 10 10 10 10 PONCA CITY OK 95 77 99 77 / 40 10 0 0 DURANT OK 98 77 99 76 / 10 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR OKZ006>008-011>013-017>020-024>026-029>032-042-043-047- 048-051-052. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
324 AM CDT Thu Jul 23 2015 .SHORT TERM... (Today and tonight) The development of mid-level cumuliform clouds from Midland, to Haskell, to Albany over the past few hours implies a region of ascent moving across West TX. The TTU WRF and HRRR are hinting at the potential for a few showers early this morning, but anything that develops should remain west of Sweetwater. Farther south, low stratus over the Hill County is increasing in coverage and advecting north. This cloud cover will likely affect the southeast portion of the CWA through around 9 AM. Otherwise, expect hot and dry conditions across West Central TX with afternoon highs in the upper 90s to around 101 degrees. Skies will be mostly clear tonight, although a few low clouds will be possible along the I-10 corridor after 3 AM. Winds will remain under 10 mph with overnight lows in the mid 70s. Johnson .LONG TERM... (Friday through Wednesday) No relief in sight from the heat in the extended forecast. Temperatures may even get a degree or two hotter this weekend as the center of upper level high pressure moves back over West Texas, with highs in the 99 to 102 range. && .PRELIMINARY POINT TEMPS/POPS... Abilene 99 77 98 77 99 / 0 0 0 5 5 San Angelo 101 76 101 76 102 / 0 0 0 5 5 Junction 99 75 97 75 99 / 0 0 0 5 5 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1157 PM MDT WED JUL 22 2015 .UPDATE... ISSUED AT 906 PM MDT WED JUL 22 2015 THUNDERSTORM ACTIVITY HAS DECREASED SUBSTANTIALLY OVER THE LAST FEW HOURS. WILL SEE ISOLATED SHOWER ACTIVITY CONTINUE THIS EVENING BUT BY MIDNIGHT MOST ALL SHOWERS SHOULD HAVE DISSIPATED. COULD SEE A FEW SHOWERS LINGER INTO THE NW PORTIONS OF THE FORECAST AREA BUT NOT EXPECTING MORE THAN A FEW SPRINKLES. UPDATE ISSUED AT 442 PM MDT WED JUL 22 2015 UPDATED THUNDERSTORM CHANCES TO INCLUDE THE NORTHERN NEBRASKA PANHANDLE AND ALL OF EAST CENTRAL WYOMING FOR EARLY THIS EVENING. CURRENTLY A LINE OF THUNDERSTORMS IS MAKING ITS INTO THAT AREA AND WITH A VERY UNSTABLE AIRMASS AND INCREASING SURFACE BASED CAPE VALUES...STORMS SHOULD CONTINUE TO PROPAGATE ACROSS THAT AREA OVER THE NEXT SEVERAL HOURS. WITH LIMITED SHEAR SEVERE THUNDERSTORM THREAT IS ON THE LOW SIDE BUT HIGHER CAPE VALUES DO SUPPORT SOME STRONGER PULSE THUNDERSTORMS. MARGINAL SEVERE HAIL...HEAVY RAIN AND WIND GUSTS TO 60 MPH CAN NOT BE RULED OUT OVER THROUGH EARLY EVENING. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 230 PM MDT WED JUL 22 2015 LATEST WATER VAPOR DEPICTING LAST OF MONSOONAL MOISTURE ACROSS SOUTHEAST WYOMING THIS AFTERNOON. SIGNIFICANT DRYING ON WATER VAPOR OVER MOST OF COLORADO IS INCHING EVER SO SLOWLY NORTHWARD TOWARDS THE SOUTHERN WYOMING BORDER. SEEING SCATTERED SHOWERS AND THUNDERSTORMS ON AREA RADAR THIS AFTERNOON...MAINLY ALONG THE WYOMING/COLORADO BORDER AND MOUNTAIN RANGES TO OUR WEST AND NORTH. SURFACE BASED CAPE OFF THE MESOANALYST PAGE SHOWING RIGHT AROUND 500 J/KG WHERE THESE THUNDERSTORMS ARE FORMING...SO DO NOT EXPECT ANY SEVERE TSTMS FROM THESE. BETTER INSTABILITY ACROSS THE PANHANDLE WHERE CAPES ARE RUNNING 1500-2500 J/KG AT 1 PM THIS AFTERNOON. DEWPOINTS ACROSS THE PANHANDLE NEAR 60 FOR ALLIANCE...SCOTTSBLUFF AND SIDNEY. WILL NEED TO WATCH THUNDERSTORM EVOLUTION AS THE AFTERNOON PROGRESSES OUT THAT WAY. LATEST HRRR FORECAST RADAR SHOWING THE POSSIBILITY OF A FEW STRONG STORMS MAKING IT INTO THIS MORE UNSTABLE AIR IN THE PANHANDLE THIS AFTERNOON AROUND 00Z. CAN NOT RULE OUT ONE OR TWO SEVERE STORMS FOR THIS EVENING OUT THAT WAY. SHEAR OUT THAT WAY ALMOST NONEXISTENT...WITH LONG SKINNY CAPE PROFILES...SO THINK THE MORE PROMINENT HAZARD WOULD BE HEAVY RAIN. ATTENTION TURNS TO ELEVATED FIRE CONDITIONS THURSDAY AND FRIDAY. GFS FORECASTING THE LOW PRESSURE SYSTEM CURRENTLY OVER SOUTHERN BRITISH COLUMBIA...TO TRACK INTO NORTHERN MONTANA THURSDAY. THIS IS A FAVORABLE WIND PATTERN FOR SOUTHEAST WYOMING. AS A RESULT...WESTERLY WINDS BEGIN TO INCREASE OUT ACROSS CARBON AND ALBANY COUNTIES. GFS 700MB WINDS OF 30-35KTS THURSDAY AFTERNOON. LOOKS LIKE THE AREA WILL MIX UP TO AT LEAST 580MBS OUT THAT WAY. NAM WINDS UP AROUND THAT LEVEL FORECAST AT 35-40KTS...SO CARBON AND ALBANY COUNTIES COULD BE SEEING WINDS GUSTING TO 40MPH OR MORE. FORTUNATELY...FUELS ARE STILL BEING REPORTED AS NOT READY FOR MOST FIRE ZONES...SO RED FLAG WARNINGS ARE NOT EXPECTED. WINDS EASE SOME FRIDAY AS THE LOW TRACKS EAST INTO SOUTHERN ALBERTA CANADA AND EASTWARD. LESS CLOUD COVERAGE AND 700MB TEMPERATURES CLIMBING TO +16C FRIDAY AND SATURDAY SHOULD LEAD TO SOME VERY WARM TEMPERATURES. DID GO OVER GUIDANCE ON HIGHS FOR THURSDAY AND FRIDAY. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 230 PM MDT WED JUL 22 2015 UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS/HIGH PLAINS WILL MEANDER OVER THAT GENERAL AREA THROUGH THIS PERIOD. THE CWA WILL RESIDE ON THE NORTHERN PERIPHERY OF THE HIGH WITH WARM AND MAINLY DRY WEATHER EXPECTED OVERALL...WITH THE WARMEST DAYS SATURDAY THROUGH MONDAY. A COUPLE DISTURBANCES SHOULD ROTATE OVER THE HIGH AND MAY BRING SOME CONVECTION TO PARTS OF THE CWA...MAINLY SUNDAY AND WEDNESDAY. MONSOONAL MOISTURE LOOKS LIKE IT WILL REMAIN CUT OFF FOR THE MOST PART. AN UPPER LOW WILL MOVE EAST ACROSS THE SOUTHERN CANADIAN PRAIRIES MONDAY THROUGH TUESDAY AND SHOULD DRIVE A COOL FRONT ACROSS THE CWA MONDAY NIGHT WITH TEMPS LOWERING CLOSER TO SEASONAL AVERAGES FOR TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1153 PM MDT WED JUL 22 2015 NO AVIATION CONCERNS TONIGHT WITH LIGHT WINDS AND CLEAR SKIES FOR MOST OF THE FORECAST AREA. A FEW SHOWERS WILL BE POSSIBLE INTO CENTRAL PORTIONS OF WYOMING BUT WILL HAVE MINIMAL TO NO IMPACT ON AVIATION. WEST TO SOUTHWEST WINDS WILL BECOME GUSTY ACROSS SOUTHEAST WYOMING THURSDAY AFTERNOON. GUSTS AROUND 25 MPH INTO THE PLAINS WITH GUSTS UP TO 35 MPH INTO SOUTH CENTRAL WYOMING. && .FIRE WEATHER... ISSUED AT 230 PM MDT WED JUL 22 2015 A DRIER AND MORE WINDY PERIOD AHEAD FOR THE REMAINDER OF THE WEEK AFTER SHOWERS AND THUNDERSTORMS END TODAY. MONSOONAL MOISTURE FORECAST TO BE SUPPRESSED SOUTH AND EAST BY THURSDAY. LOW PRESSURE TRACKING THROUGH NORTHERN MONTANA THURSDAY WILL AID IN INCREASING WESTERLY TO SOUTHWESTERLY WINDS...ESPECIALLY WEST OF THE LARAMIE RANGE THURSDAY AND FRIDAY. ELEVATED FIRE WEATHER CONCERNS WITH THESE WINDS AND AFTERNOON HUMIDITIES FALLING TO 15 PERCENT BOTH AFTERNOONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...SML SHORT TERM...GCC LONG TERM...RE AVIATION...SML FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
933 AM MDT THU JUL 23 2015 .UPDATE... ISSUED AT 927 AM MDT THU JUL 23 2015 SATELLITE IMAGERY CONTINUES TO SHOW CLEARING OVER LINCOLN COUNTY AS THE REGION IS UNDER A DRIER WEATHER PATTERN. WITH DECREASED MOISTURE AND CLEARING SKIES HAVE INCREASED TEMPERATURES OVER THE FRONT RANGE A FEW DEGREES BUT OVERALL ON TRACK TO REACH THE MID 90S TODAY. LATEST HRRR GUIDANCE SHOWING SOME DEVELOPMENT OVER THE SOUTHERN MOST PORTIONS OF THE REGION SOUTH OF I-70 ALONG THE FOOTHILLS AS WELL AS DOUGLAS AND LINCOLN COUNTIES LATER THIS AFTERNOON. THIS COINCIDES WITH SOME MOISTURE THAT WILL MAKE ITS WAY INTO THE AREA LATER THIS AFTERNOON BUT NOT VENTURE ANY FURTHER NORTH THAN I-70. DO NOT EXPECT MUCH OUT OF THESE STORMS BUT SOME LIGHT TO MODERATE RAIN. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 419 AM MDT THU JUL 23 2015 A LITTLE BIT OF WARMING ALOFT SHOULD LIMIT CONVECTION TODAY...THOUGH THERE IS STILL ENOUGH MOISTURE AROUND FOR SOME CLOUD DEVELOPMENT AND ISOLATED STORMS. MOISTURE WILL BE BETTER IN THE SOUTHERN PART OF THE AREA. PREVIOUS FORECAST LIMITED THE MENTION OF POPS TO THE MOUNTAINS SOUTH OF INTERSTATE 70...AND THEN AREAS NEAR THE FOOTHILLS FROM DENVER SOUTHWARD DURING THE EVENING. WILL STICK WITH THIS IDEA...JUST ENDING THE THREAT BY MID EVENING. TEMPERATURES SHOULD BE A FEW DEGREES WARMER...WHICH MEANS MOSTLY MID 90S ON THE PLAINS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 419 AM MDT THU JUL 23 2015 AMPLIFIED WAVE PATTERN OVER THE WESTERN CONUS FIRST HALF OF THE PERIOD WITH UPPER RIDGE OVER THE LOWER GREAT PLAINS AND TROUGH OVER THE PACIFIC NORTHWEST FLATTENS OUT WITH FLOW ALOFT BECOME NEARLY ZONAL LATE IN THE PERIOD. MODELS IN REASONABLY GOOD AGREEMENT THOUGH THE GFS CONTINUES TO BE THE WETTER OF THE MEDIUM RANGE MODELS AS IT IS RELUCTANT TO SEVER THE TIE TO THE SOUTHWEST MONSOON. ON FRIDAY...COLORADO REMAINS SANDWICHED BETWEEN A STRONG UPPER RIDGE AND BERMUDA SFC HIGH OVER THE SOUTHERN GREAT PLAINS AND AN UPPER TROUGH WHICH MODELS SHOW SLIPPING SOUTH DOWN THE PACIFIC NORTHWEST COAST. THE TWO SYSTEMS KEEP THE FORECAST AREA UNDER SWLY FLOW ALOFT. AGAIN GFS APPEARS WETTER AS IT SHOWS A COLUMN OF MID/HIGH LEVEL MOISTURE SPREADING OVER THE STATE DURING THE DAY. WHEREAS THE EUROPEAN AND CANADIAN MODELS SHOW A DRIER AND SLIGHTLY MORE WESTERLY FLOW ALOFT. AT ANY RATE...INTEGRATED PRECIPITABLE WATER VALUES START THE DAY ON THE LOW SIDE...E.G. AROUND A HALF INCH ALONG THE FRONT RANGE...AND THEN STEADILY RISE THROUGH THE DAY TO AROUND AN INCH WITH THE BNDRY LAYER FLOW TURNING E-NELY. AND YET..THE PLAINS AIRMASS APPEARS TO REMAIN STRONGLY CAPPED WITH WARMING ALOFT. CAPE AND STEEP LAPSE RATES REMAIN LARGELY CONFINED TO HIGHER DEWPOINT AIR ALONG THE EASTERN- SOUTHEASTERN FRINGE OF THE FCST AREA. FOR THAT REASON WILL ASSIGN LOW POPS IN THIS AREA...AND INCLUDE LOW POPS IN THE FOOTHILLS AND SOUTH PARK AREAS. TEMPS ON FRIDAY REMAIN ABOVE AVERAGE WITH LOW/MID 90S AT LOWER ELEVATIONS AND MOSTLY 70S IN THE HIGH COUNTRY. OVER THE WEEKEND...THE SRN PLAINS RIDGE APPEARS TO WEAKEN SLIGHTLY AND SLIP A BIT FARTHER SOUTHEAST. THIS ALLOWS FOR MORE MONSOONAL MOISTURE TO MAKES IT WAY UP INTO COLORADO ON SWLY FLOW. GFS CONTINUES TO RUN WETTER THAN THE OTHER MODELS ALTHOUGH THE EUROPEAN AND CANADIAN ALSO LOOK WETTER AT LEAST AT MID-LEVELS. PW VALUES ON THE PLAINS START THE DAY ON A HIGH NOTE AROUND AN INCH...BUT THEN DROP OFF DURING THE DAY WITH THE SFC-700MB FLOW BNDRY BECOMING W- SWLY/DOWNSLOPE. HOWEVER SELY BNDRY LAYER FARTHER OUT ON THE PLAINS KEEPS PW VALUES UP AROUND AND INCH PRODUCING 0-3KM CAPES IN THE 500- 1000 J/KG SUFFICIENT TO KEEP A LOW CHANCE OF AFTERNOON/EVENING T- STORMS OUT THERE AS WELL AS OVER THE SRN FOOTHILLS AND SOUTH PARK. ELSEWHERE SHOULD REMAIN STORM FREE. TEMPS ON SATURDAY 1-3DEG F COOLER THAN FRIDAY DUE IN PART TO GREATER CLOUD COVER. ON SUNDAY...FLOW ALOFT TURNS MORE WESTERLY LEADING TO LOWER HUMIDITY...LESS CLOUD COVER AND SLIGHTLY HIGHER TEMPS. MONDAY-WEDNESDAY...THE PACIFIC NORTHWEST TROUGH IS PROGGED TO MIGRATE EASTWARD ALONG THE U.S/CANADIAN BORDER FLATTENING OUT THE FLOW ALOFT. HOWEVER AS THE UPPER TROUGH PASSES TO OUR NORTH ON TUESDAY...MODELS SHOW A WEAK COLD FRONT PUSHING UP AGAINST THE FRONT RANGE AND WITH A MOIST UP SLOPE FLOW...SHOULD SEE RAIN CHANCES CREEP UP. TEMPS ON THE PLAINS TUESDAY AS MUCH AS 4-6 DEG F COOLER. ZONAL FLOW ON WEDNESDAY WILL DRY THINGS OUT AND LARGELY CONFINE ANY PRECIP/T-STORMS TO THE HIGHER TERRAIN. LOOK FOR TEMPS ON WEDNESDAY TO BE A DEG OR TWO WARMER. && .AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING) ISSUED AT 927 AM MDT THU JUL 23 2015 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD FOR ALL AIRPORTS. SOME MID TO HIGH LEVEL SCATTERED DECK WILL PERSIST ON AND OFF THROUGH THE AFTERNOON WITH LIGHT TO VARIABLE WINDS FROM THE SW. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BOWEN SHORT TERM...GIMMESTAD LONG TERM...BAKER AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1029 AM EDT THU JUL 23 2015 .SYNOPSIS... LOW PRESSURE OVER NORTHERN SOUTH CAROLINA WILL MOVE EAST ALONG A STALLED FRONT TODAY AND OFF THE COAST TONIGHT. THIS LOW WILL PUSH THE FRONT INTO GEORGIA FOR THIS WEEKEND. HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH...WITH A DRYING TREND EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM THURSDAY...ANALYSIS OF MORNING SOUNDINGS AND LATEST GUIDANCE CONFIRM EARLIER FORECAST OF AN ACTIVE WEATHER DAY...ESPECIALLY THIS AFTERNOON AND EVENING...WITH THE PRIMARY THREATS BEING HEAVY RAIN AND UNUSUALLY FREQUENT LIGHTNING. DAMAGING WIND GUSTS ARE ALSO A POSSIBILITY. NO CHANGES NEEDED YET TO THE FORECAST. PREVIOUS DISCUSSION FOLLOWS: LOW PRESSURE CENTERED OVER THE SC SANDHILLS WILL MOVE EASTWARD ALONG A STATIONARY FRONT TODAY...EXITING INTO THE ATLANTIC OCEAN TONIGHT. MODELS ARE ALMOST UNANIMOUS IN THEIR DEPICTION OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING WITHIN A REGION OF LOW-LEVEL CONVERGENCE AND LARGE INSTABILITY OVER SOUTHERN NORTH CAROLINA JUST NORTH OF THE STATIONARY FRONT LATE THIS MORNING. SURFACE CAPE IS PREDICTED TO GROW AS LARGE AS 3000 J/KG WITH LIFTED INDICES TO -6. 700 MB WINDS INCREASING TO 25 KT SHOULD INCREASE BULK SHEAR VALUES JUST ENOUGH TO PRODUCE ORGANIZED MULTICELLULAR STORMS TODAY...WITH COLD POOL EFFECTS LIKELY PUSHING THE CLUSTER SOUTHEASTWARD ACROSS THE CAPE FEAR AREA EARLY THIS AFTERNOON AND INTO NORTHEASTERLY SOUTH CAROLINA BY MID TO LATE AFTERNOON. IMPACTS FROM THESE STORMS COULD BE CONSIDERABLE. COMPUTED EQUILIBRIUM PARCEL HEIGHTS NEAR 50000 FT AND LOTS OF INSTABILITY ABOVE THE -20C LEVEL INDICATES THESE STORMS COULD BE ENORMOUS LIGHTNING PRODUCERS WITH PLENTY OF ICE/GRAUPEL GENERATION ALOFT. ALTHOUGH NO DRY LAYERS ARE EVIDENT IN FORECAST SOUNDINGS PRECIPITATION LOADING RESULTING FROM SUCH VIGOROUS CONVECTION SHOULD PRODUCE GUSTY WINDS...PARTICULARLY AS THE STORMS ARE SHOWN IN THE HIGH RESOLUTION WRF-NMM...WRF-ARW...AND HRRR MODELS TO FORM A LARGE MASSED OUTFLOW PUSHING SOUTHEASTWARD TO THE COAST. WITH THE SYNOPTIC FRONT STALLED ACROSS THE AREA AND ANTICIPATED BOUNDARY COLLISIONS THE STORMS SHOULD ALSO BE HEAVY RAIN MAKERS WITH LOCALIZED FLOODING POSSIBLE. FORECAST RAIN CHANCES HAVE BEEN INCREASED TO 80 PERCENT ACROSS SE NORTH CAROLINA...FOCUSED ON THE NOON-4 PM TIMEFRAME. CONVECTION SHOULD TAKE SEVERAL ADDITIONAL HOURS TO PROPAGATE SOUTHWARD AND AFFECT NE SOUTH CAROLINA WHICH WILL BE LOCATED SOUTH OF THE STATIONARY FRONT. THIS MEANS SEVERAL ADDITIONAL HOURS OF HOT SUNSHINE...AND TEMPERATURES HERE WILL RISE INTO THE MID TO UPPER 90S. FORECAST HEAT INDICES ARE JUST BELOW 105-DEGREE HEAT ADVISORY CRITERIA ACROSS GEORGETOWN...WILLIAMSBURG AND SOUTHERN FLORENCE COUNTIES. AN UPPER LEVEL DISTURBANCE CURRENTLY PRODUCING THUNDERSTORMS OVER CENTRAL TENNESSEE WILL REACH THE EASTERN CAROLINAS THIS EVENING. THIS COULD HELP CONVECTIVE ACTIVITY TO PERSIST INTO THE EVENING HOURS EVEN AFTER THE ATMOSPHERE PRETTY MUCH OVERTURNS DURING THE AFTERNOON. THE LOW WILL SCOOT EASTWARD ALONG THE FRONT OFFSHORE AFTER MIDNIGHT WITH SURFACE WINDS TURNING NORTHWESTERLY...QUITE AN ODD DIRECTION FOR THE CAROLINAS IN THE MIDDLE OF SUMMER. THIS IS THE THIRD COLD FRONTAL PASSAGE OF JULY! && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LATEST MODELS SHOW LOW JUST OFF THE CAPE FEAR COAST FRI MORNING. EXPECT BEST CONVECTION OVER THE COASTAL WATERS WITH MOST AREAS SEEING A DEEP FLOW OF DRIER AIR ADVECTING IN FROM THE NORTH. MID TO UPPER TROUGH WILL PUSH LOW PRESSURE ALONG LINGERING BOUNDARY SOUTH AND EAST OF AREA THROUGH THE DAY...BUT PLENTY OF RESIDUAL LOW LEVEL MOISTURE FROM PREVIOUS DAYS CONVECTION WILL SLOW CLEARING AND COMBINE WITH CONVERGENCE ASSOCIATED WITH LOW AND OTHER LOCALIZED BOUNDARIES SUCH AS THE SEA BREEZE TO PRODUCE SOME SHWRS/TSTMS. LOOKS LIKE BEST CHC WILL MOVE SOUTH THROUGH THE DAY AS HIGH PRESSURE BEGINS TO BUILD DOWN FROM THE NORTH BUT MAY NOT BE FAST ENOUGH TO ELIMINATE POPS FROM FORECAST. NAM SHOWS MAIN FOCUS OF CONVECTION ALONG COASTAL SOUTH CAROLINA WHERE BEST CONVERGENCE SHOULD BE AS WE DEVELOP A N-NE FLOW. MAY SEE ENOUGH SUBSIDENCE AND DRY AIR THROUGH THE MID TO UPPER LEVELS BY LATE FRI TO ALLOW FOR ONLY A DECENT STRATOCU FIELD OVER NC. PCP WATER VALUES OVER 2 INCHES EARLY FRI MORNING WILL DROP DOWN CLOSE TO AN INCH BY SAT MORNING. LINGERING CLOUDS AND PCP WILL KEEP TEMPS IN THE 80S MOST OF THE DAY BUT PLACES THAT SEE SOME SUN MAKE AN APPEARANCE WILL REACH CLOSE TO 90. BY LATE FRI INTO FRI NIGHT...PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID TO UPPER LEVELS WILL REACH DOWN OVER THE FORECAST AREA AS DRY HIGH PRESSURE AT THE SFC NOSES DOWN FROM THE NORTH. WILL SHOW CLEARING AT THIS TIME AND WILL KEEP PCP OUT OF FORECAST THROUGH THE REMAINDER OF THE WEEKEND. PLENTY OF BRIGHT JULY SUNSHINE WILL DRIVE TEMPS UP NEAR NORMAL...CLOSE TO 90 BUT SFC DEWPOINT TEMPS WILL BE RUNNING IN THE LOW TO MID 60S MOST PLACES WHICH WILL MAKE FOR A MUCH MORE REFRESHING DAY THAN PREVIOUS ONES. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM THURSDAY...CENTER OF HIGH PRESSURE NOSING DOWN FROM THE NORTH WILL SHIFT OFF THE MID ATLANTIC COAST ALLOWING WINDS TO COME AROUND TO A MORE ON SHORE NE TO E FLOW. WEAK HIGH PRESSURE WILL CONTINUE TO REACH DOWN INTO THE CAROLINAS THROUGH MID WEEK AS LEE SIDE TROUGH BECOMES MORE PRONOUNCED. RIDGING IN THE MID TO UPPER LEVELS OVER THE MID WEST WILL BUILD EASTWARD OVER THE WEEKEND...BUT AS IT BECOMES MORE AMPLIFIES UP THROUGH THE UPPER MIDWEST BY TUES...A DEEPER NW FLOW ALOFT WILL ALLOW SOME CLOUDS AND SHORTWAVE ENERGY TO SNEAK INTO AREA BUT RIDGE WILL BUILD BACK EAST AND UP THE EAST COAST THROUGH MID WEEK AND THEREFORE MAY INTRODUCE INCREASED CLOUDS AND SHWRS FOR TUES/WED TIME FRAME BUT OVERALL SHWR ACTIVITY SHOULD REMAIN MORE ISOLATED HEADING INTO MID WEEK AS RIDGE BUILDS BACK IN. THE ON SHORE FLOW DEVELOPING THROUGH THE PERIOD WILL AID IN BRINGING DEWPOINT TEMPS BACK UP CLOSER TO 70 OR SO...HELPING TO INCREASE AFTN CU AND CHC OF SOME CONVECTIVE DEVELOPMENT. TEMPS WILL BASICALLY REMAIN AROUND CLIMO. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... AS OF 12Z...TERMINALS ARE CURRENTLY VFR ALTHOUGH SOME MVFR VSBYS IN BR COULD OCCUR MAINLY AT KLBT UNTIL 13Z. A WEAK FRONT IS LOCATED FROM NEAR KFLO TO KMYR. WINDS THIS MORNING WILL BE ESE-SE AT KILM/KLBT WITH S-SW WINDS ELSEWHERE. THUNDERSTORMS ARE A SURE BET TODAY AND WILL EVENTUALLY AFFECT EVERY TERMINAL. CONFIDENCE IN EXACT TIMING IS LOW BUT KLBT SHOULD BE INITIALLY AFFECTED BY LATE MORNING THEN KILM/KFLO TOWARDS EARLY AFTERNOON. KCRE/KMYR SHOULD BE AFFECTED MOSTLY IN THE AFTERNOON. TEMPO IFR WITH WIND GUSTS TO 35 KT POSSIBLE WITH THE STORMS. THUNDERSTORMS SHOULD END IN THE 21-00Z TIME FRAME WITH VFR LIKELY... BUT SHOWERS WILL POTENTIAL PERSIST INTO THE EVENING HOURS. WINDS BECOME LIGHT AND VARIABLE OR LIGHT NW LATE AFTERNOON AND EVENING. THERE IS A FOG POTENTIAL MAINLY KFLO/KLBT OVERNIGHT WITH LOW TO MODERATE POTENTIAL FOR IFR. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM ISOLATED CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM THURSDAY...LATEST OBS SHOW 2 FT SEAS WITH SSE WINDS OF 10 TO 15 KTS. FORECAST ON TRACK WITH NO CHANGES NEEDED. PREVIOUS DISCUSSION FOLLOWS: LOW PRESSURE CENTERED OVER THE SOUTH CAROLINA SANDHILLS WILL MOVE EASTWARD TODAY ALONG A WEAK STATIONARY FRONT. THIS FRONT CURRENTLY SITS JUST NORTH OF CAPE FEAR AND IS OUTLINED BY A SHIFT IN WIND DIRECTIONS FROM SOUTHERLY ALONG THE SC COAST TO SOUTHEASTERLY FROM WRIGHTSVILLE BEACH AND SURF CITY TO THE OUTER BANKS. AS INLAND AREAS HEAT UP QUICKLY THIS MORNING ATMOSPHERIC CONDITIONS ARE STRONGLY SUPPORTIVE OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING ACROSS SOUTHERN NORTH CAROLINA...DROPPING SOUTHEASTWARD AND AFFECTING THE COASTAL WATERS DURING THE AFTERNOON. THESE STORMS WILL LIKELY CONTAIN LARGE AMOUNTS OF LIGHTNING AND SUBSTANTIAL VISIBILITY RESTRICTIONS IN HEAVY RAIN. SEVERAL OF THE HIGH- RESOLUTION MODELS INDICATE THE POTENTIAL FOR A STRONG GUST FRONT AT THE LEADING EDGE OF THE STORMS WHICH MAY PROMPT SPECIAL MARINE WARNINGS THIS AFTERNOON. MARINERS IN THE CAPE FEAR AREA SHOULD EXPECT THE LARGEST IMPACT FROM THESE STORMS BETWEEN 1-3 PM...WITH THE GRAND STAND AND GEORGETOWN AREAS A COUPLE HOURS LATER. LATE TONIGHT AS THE LOW SHIFTS EASTWARD ALONG THE FRONT AND ENTERS THE ATLANTIC OCEAN SURFACE WINDS WILL SHIFT NORTHWESTERLY AND MAY INCREASE TO 10-15 KT LATE. OUTSIDE OF THUNDERSTORMS SEAS SHOULD AVERAGE 2 FEET TODAY...AND 2-3 FEET TONIGHT. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LOW PRESSURE ALONG LINGERING BOUNDARY WILL SLIP FARTHER SOUTH THROUGH THE DAY ON FRIDAY. NORTHEAST FLOW WILL DEVELOP BEHIND THIS BOUNDARY AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH THROUGH THE WEEKEND. EXPECT WINDS TO REMAIN BELOW 15 KTS ACROSS MOST OF THE WATERS...BUT THERE SHOULD BE SOME PERIODS OF HIGHER WAVES...UP CLOSER TO 20 KTS. THE WINDS WILL BEGIN TO VEER AROUND FROM THE NE TO E. THE PERSISTENT STRONGER NE TO E ON SHORE FLOW WILL PRODUCE SEAS UP TO 3 TO 5 FT...ESPECIALLY THROUGH SAT NIGHT. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 330 AM...HIGH PRESSURE EXTENDING DOWN INTO THE CAROLINAS FROM THE NORTHEAST WILL MOVE FARTHER EAST THROUGH THE PERIOD...ALLOWING WINDS TO LIGHTEN AND VEER TO THE EAST. THE WINDS SHOULD DECREASE TO 10 KTS OR LESS MOST OF THE TIME...BUT SEA BREEZE EACH AFTN WILL ACT TO ENHANCE OVERALL ON SHORE FLOW. EXPECT SEAS TO BE COMING DOWN AS WINDS LIGHTEN HEADING THROUGH LATE SUNDAY INTO MONDAY. THEREFORE SEAS UP TO 3 TO 5 FT EARLY SUNDAY SHOULD DROP TO 2 TO 4 FT SUN NIGHT. AS SHORTER PERIOD WINDWAVE DIMINISHES THROUGH MONDAY AND WNA CONTINUES TO SHOW A LONGER PERIOD UP TO 11 SEC WAVE MIXING IN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...REK/TRA SHORT TERM...RGZ LONG TERM...RGZ AVIATION...MRR MARINE...REK/TRA/RGZ
AREA FORECAST DISCUSSION
NWS RALEIGH NC
930 AM EDT THU JUL 23 2015 .SYNOPSIS...A WAVE OF LOW PRESSURE DEVELOPING ALONG A STALLED FRONTAL ZONE IN UPSTATE SOUTH CAROLINA WILL TRACK SLOWLY EAST TOWARD THE CAROLINA COAST THIS AFTERNOON INTO TONIGHT...THEN STALL OFFSHORE THE SOUTHEAST COAST OVER THE WEEKEND AS WEAK HIGH PRESSURE EXTENDS INTO THE REGION FROM THE NORTH. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 930 AM THURSDAY... FORECAST LARGELY ON TRACK WITH SMALL SPATIAL/TEMPORAL MODIFICATIONS. SEVERAL CLUSTERS OF SHOWERS/STORMS ARE PROGRESSING ESE OVER THE FAR NRN AND NE CWA... WITHIN A BAND OF ENHANCE LOW LEVEL MOISTURE CONVERGENCE ALONG A TIGHT THETA-E GRADIENT. PW VALUES OVER CENTRAL NC HAVE SURGED WELL BACK UP ABOVE NORMAL IN THE LAST 12 HRS... FACILITATING A VOLATILE ATMOSPHERE WITH SCATTERED TO NUMEROUS SHOWERS AND STORMS FUELED BY WEAK TO MODERATE INSTABILITY... IMPROVING DYNAMIC FORCING FOR ASCENT AS A MID LEVEL WAVE TRACKS FROM TN ACROSS THE CAROLINAS TODAY... AND IMPROVING KINEMATICS AS WELL- DEFINED SURFACE LOW PRESSURE PERSISTS ALONG THE FRONTAL ZONE OVER NRN SC. THE LATEST HRRR RUNS AND THE NSSL WRF HAVE DONE A GOOD JOB WITH CONVECTION SO FAR THIS MORNING... AND BOTH SHIFT THE GREATER STORM COVERAGE (50-60%) FROM THE NE CWA TO THE SOUTHEAST THIS AFTERNOON... WHERE LOW LEVEL MASS CONVERGENCE ENE OF THE LOW WILL BE HIGHEST WITH THE BETTER POTENTIAL FOR INSTABILITY. WILL RETAIN A TREND TO LIKELY POPS IN THIS AREA. EFFECTIVE DEEP LAYER SHEAR REMAINS MARGINAL AT 20-30 KTS BUT STILL ENOUGH FOR A THREAT OF ISOLATED STRONG TO DAMAGING WIND GUSTS WITH ANY CELLS. MODELS THEN REDEVELOP SHOWERS AND ISOLATED STORMS BACK OVER THE SW CWA THIS EVENING... AS THE MID LEVEL WAVE MOVES IN... IN CONJUNCTION WITH FORMATION OF A NEW LEE LOW OVER UPSTATE SC. WILL KEEP THE TREND BACK TOWARD HIGH POPS THIS EVENING IN OUR SW... SPREADING EAST OVERNIGHT... ALTHOUGH WILL RE-EVALUATE POTENTIAL COVERAGE THIS AFTERNOON. THE CLOUDS/PRECIP AND LIGHT NE FLOW ARE BOUND TO HOLD TEMPS DOWN BELOW NORMAL TODAY IN THE NE. EXPECT HIGHS FROM THE LOW 80S N TO NEAR 90 SOUTH... PREDICATED ON GETTING AT LEAST SOME ISOLATION NORTH THIS AFTERNOON BEHIND THE ONGOING CONVECTION. -GIH PREVIOUS DISCUSSION FROM 400 AM... OVERVIEW: DIFFICULT FORECAST. 06Z SPC MESOANALYSIS AND REMOTE SENSING DATA INDICATED NUMEROUS SMALL AMPLITUDE WAVES TRACKING EAST/ESE ALONG THE SOUTHERN FRINGE OF THE WESTERLIES THROUGH THE TN VALLEY THIS MORNING...DOWNSTREAM OF A PRONOUNCED UPPER LEVEL RIDGE ANCHORED OVER THE LOWER MIDWEST. IN RESPONSE TO DPVA ATTENDANT AN APPROACHING DISTURBANCE...A WEAK SURFACE LOW IS DEVELOPING ALONG A STALLED FRONTAL ZONE SITUATED ACROSS UPSTATE SC/SOUTHWEST NC (NEAR SHELBY NC) AND WEAK WARM ADVECTION HAS COMMENCED OVER CENTRAL NC AS 925-850 MB FLOW BACKS IN ADVANCE OF THE WAVE. WITH ADDITIONAL SMALL AMPLITUDE WAVES PRESENT UPSTREAM AND A WIDE VARIETY OF MECHANISMS (CONVECTION /LATENT HEAT RELEASE/ IN PARTICULAR) THAT CAN AFFECT THE EVOLUTION OF LOW-LEVEL HEIGHT/WIND/MOISTURE FIELDS...CONFIDENCE REMAINS LOW WITH REGARD TO CONVECTIVE COVERAGE/TIMING TODAY INTO TONIGHT. QUALITATIVELY...GIVEN THE PATTERN ONE WOULD EXPECT INCREASED CLOUD COVER...CHANCES FOR CONVECTION...AND AT OR BELOW NORMAL TEMPERATURES. CONVECTION: IN RESPONSE TO WEAK LOW-LEVEL CONVERGENCE...WARM ADVECTION... APPROACHING DPVA... AND NOCTURNAL DESTABILIZATION (DRIVEN BY LOW-LEVEL MOISTURE ADVECTION)...ISOLATED ELEVATED CONVECTION HAS ALREADY DEVELOPED IN VICINITY OF HWY 64. THE LATEST RAP GUIDANCE SUGGESTS ELEVATED CONVECTION WILL INCREASE IN COVERAGE AND INTENSITY ALONG/NORTH OF HWY 64 THROUGH 15Z AS THE EASTERN-MOST UPPER LEVEL DISTURBANCE APPROACHES...LOW-LEVEL CONVERGENCE STRENGTHENS /FLOW BACKS/...AND MOISTURE ADVECTION AIDS IN FURTHER DESTABILIZATION. AS THE LEAD DISTURBANCE PROGRESSES EAST ACROSS CENTRAL NC BY EARLY AFTERNOON...THE DEVELOPING SFC-H925 LOW IS EXPECTED TO WEAKEN/BROADEN OVER WESTERN NC...WITH AN ATTENDANT WEAKENING OF WARM ADVECTION AS LOW-LEVEL FLOW VEERS TO THE SOUTH AND WEAKENS ACROSS CENTRAL NC. HOWEVER...WEAK LOW-LEVEL CONVERGENCE AND DIURNAL DESTABILIZATION WITHIN THE WARM SECTOR SHOULD BE SUFFICIENT FOR ANY ONGOING CONVECTION TO PERSIST DURING THE EARLY/MID AFTERNOON...MOST LIKELY IN THE FORM OF SFC-BASED CONVECTION PROPAGATING SOUTHEAST (ALONG OUTFLOW) THROUGH THE COASTAL PLAIN INTO EASTERN/COASTAL NC DURING THE AFTERNOON. SEVERE: THOUGH SFC-BASED CONVECTION WILL BECOME INCREASINGLY LIKELY ALONG/SOUTH OF HWY 64 AS THE WARM SECTOR SLOWLY ADVANCES FROM CAPE FEAR INTO THE SANDHILLS 08-12Z...CONVECTION SHOULD REMAIN ELEVATED IN NATURE NORTH OF THE I-85 CORRIDOR. BY OR SHORTLY AFTER SUNRISE... MARGINAL TO MODERATE INSTABILITY AND DEEP LAYER SHEAR ~30 KT WILL CONTRIBUTE TO SUPERCELL COMPOSITE PARAMETER VALUES AS HIGH AS 1-3 (PRIMARILY SOUTH AND EAST OF THE TRIANGLE)...INDICATING THAT THE ENVIRONMENT WILL BE BASICALLY SUPPORTIVE OF SEVERE WEATHER DURING THE MORNING...PRIMARILY IN THE FORM OF WET DOWNBURSTS VIA A COMBINATION OF MOMENTUM TRANSPORT (20-25 KT MID-LEVEL FLOW) AND PRECIP LOADING...PARTICULARLY WITH PWAT VALUES AS HIGH AS 2.00- 2.25". WEAK LOW-LEVEL SPEED SHEAR ON THE EASTERN PERIPHERY OF THE SFC LOW SHOULD EFFECTIVELY LIMIT 0-1 KM SRH VALUES TO NO HIGHER THAN 50-100 M2/S2 IN CENTRAL NC THIS MORNING...THOUGH VALUES AS HIGH AS 150-200 M2/S2 WILL BE POSSIBLE THIS AFTERNOON IN COASTAL NC... PERHAPS INCLUDING PORTIONS OF THE SE COASTAL PLAIN. WITH THIS IN MIND...AN ISOLATED TOR (BRIEF/LOW-END VARIETY)...CANNOT BE RULED OUT WITH VIGOROUS UPDRAFTS (IF ANY) THIS AFTERNOON...PRIMARILY FAR SE COASTAL PLAIN (I.E. SAMPSON/WAYNE/CUMBERLAND). -VINCENT && .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... AS OF 311 AM THURSDAY... THE WEAK MID/UPPER LOW WILL SLOWLY DRIFT DEEP INTO THE SE STATES FRIDAY. MOST IF NOT ALL THE SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN OUR SE COUNTIES EARLY IN THE DAY... BEFORE SHIFTING ON SOUTHWARD AND REDEVELOPING WITH DIURNAL HEATING AGAIN FRIDAY AFTERNOON. OTHERWISE... PARTLY SUNNY WITH HIGHS IN THE MID TO UPPER 80S. PARTLY CLOUDY TO MOSTLY CLEAR SKIES EXPECTED FRIDAY NIGHT WITH LOWS IN THE MID TO UPPER 60S. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 1255 AM THURSDAY... DRY WEATHER IS STILL ANTICIPATED GIVEN THE FLOW PATTERN OVER THE REGION SATURDAY AND SUNDAY. IT APPEARS THAT THERE WILL BE A SLOWLY INCREASING CHANCE OF MAINLY DIURNAL SHOWERS AND THUNDERSTORMS MONDAY THROUGH WEDNESDAY. HOWEVER... THERE CONTINUES TO BE SOME MODEL SPREAD IN WHEN THE MOISTURE/INSTABILITY WILL INCREASE ENOUGH FOR THIS TO OCCUR. WE WILL CONTINUE THE CURRENT LOW CHANCE POP FOR PM THUNDERSTORMS MONDAY THROUGH WEDNESDAY. TEMPERATURES SHOULD BE NEAR THE 30 YEAR AVERAGES FOR LATE JULY THIS WEEKEND... AND ONLY SLOWLY RISE TO ABOVE NORMAL BY TUE-WED. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 730 AM THURSDAY... ADVERSE AVIATION CONDITIONS ARE EXPECTED THIS MORNING IN THE FORM OF LIFR/IFR CEILINGS AT FAY/RDU/RWI...WITH IMPROVEMENT TO VFR EXPECTED BY NOON. EPISODIC CONVECTION IS EXPECTED THROUGH TONIGHT...LIKELY AFFECTING ALL TERMINALS...AS A WEAK SFC LOW TRACKS EAST FROM UPSTATE SOUTH CAROLINA TOWARD THE CAROLINA COAST. CONFIDENCE IN SPECIFIC DETAILS (I.E. PRECISE TIMING/COVERAGE) REMAINS BELOW NORMAL. AS A RESULT...EVEN THOUGH THUNDERSTORMS ARE LIKELY TO AFFECT ALL TERMINALS AT SOME POINT DURING THE TAF PERIOD...EXPLICIT MENTION OF THUNDER WILL NOT BE MENTIONED WITH THE 12Z TAF ISSUANCE. EXPECT WINDS TO BE LIGHT/VARIABLE OR SE/ESE AT 5-10 KT THROUGH THE TAF PERIOD. LONG TERM: ASIDE FROM A POTENTIAL FOR LINGERING LOW CEILINGS EARLY FRIDAY MORNING...VFR CONDITIONS WILL PREVAIL THROUGH THE WEEKEND AS THE AFOREMENTIONED LOW PRESSURE SYSTEM MOVES OFFSHORE AND STALLS OFF THE SE COAST. A POTENTIAL FOR ADVERSE AVIATION CONDITIONS WILL RETURN EARLY NEXT WEEK AS THE CENTRAL CONUS RIDGE SHIFTS EASTWARD AND A MORE AGGRESSIVE /ACTIVE/ NW FLOW ALOFT DEVELOPS OVER THE CAROLINAS AND MID-ATLANTIC. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD/VINCENT SHORT TERM...PWB LONG TERM...PWB AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
736 AM EDT THU JUL 23 2015 .SYNOPSIS... LOW PRESSURE OVER NORTHERN SOUTH CAROLINA WILL MOVE EAST ALONG A STALLED FRONT TODAY AND OFF THE COAST TONIGHT. THIS LOW WILL PUSH THE FRONT INTO GEORGIA FOR THIS WEEKEND. HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH...WITH A DRYING TREND EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 650 AM THURSDAY...LOW PRESSURE CENTERED OVER THE SC SANDHILLS WILL MOVE EASTWARD ALONG A STATIONARY FRONT TODAY...EXITING INTO THE ATLANTIC OCEAN TONIGHT. MODELS ARE ALMOST UNANIMOUS IN THEIR DEPICTION OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING WITHIN A REGION OF LOW-LEVEL CONVERGENCE AND LARGE INSTABILITY OVER SOUTHERN NORTH CAROLINA JUST NORTH OF THE STATIONARY FRONT LATE THIS MORNING. SURFACE CAPE IS PREDICTED TO GROW AS LARGE AS 3000 J/KG WITH LIFTED INDICES TO -6. 700 MB WINDS INCREASING TO 25 KT SHOULD INCREASE BULK SHEAR VALUES JUST ENOUGH TO PRODUCE ORGANIZED MULTICELLULAR STORMS TODAY...WITH COLD POOL EFFECTS LIKELY PUSHING THE CLUSTER SOUTHEASTWARD ACROSS THE CAPE FEAR AREA EARLY THIS AFTERNOON AND INTO NORTHEASTERLY SOUTH CAROLINA BY MID TO LATE AFTERNOON. IMPACTS FROM THESE STORMS COULD BE CONSIDERABLE. COMPUTED EQUILIBRIUM PARCEL HEIGHTS NEAR 50000 FT AND LOTS OF INSTABILITY ABOVE THE -20C LEVEL INDICATES THESE STORMS COULD BE ENORMOUS LIGHTNING PRODUCERS WITH PLENTY OF ICE/GRAUPEL GENERATION ALOFT. ALTHOUGH NO DRY LAYERS ARE EVIDENT IN FORECAST SOUNDINGS PRECIPITATION LOADING RESULTING FROM SUCH VIGOROUS CONVECTION SHOULD PRODUCE GUSTY WINDS...PARTICULARLY AS THE STORMS ARE SHOWN IN THE HIGH RESOLUTION WRF-NMM...WRF-ARW...AND HRRR MODELS TO FORM A LARGE MASSED OUTFLOW PUSHING SOUTHEASTWARD TO THE COAST. WITH THE SYNOPTIC FRONT STALLED ACROSS THE AREA AND ANTICIPATED BOUNDARY COLLISIONS THE STORMS SHOULD ALSO BE HEAVY RAIN MAKERS WITH LOCALIZED FLOODING POSSIBLE. FORECAST RAIN CHANCES HAVE BEEN INCREASED TO 80 PERCENT ACROSS SE NORTH CAROLINA...FOCUSED ON THE NOON-4 PM TIMEFRAME. CONVECTION SHOULD TAKE SEVERAL ADDITIONAL HOURS TO PROPAGATE SOUTHWARD AND AFFECT NE SOUTH CAROLINA WHICH WILL BE LOCATED SOUTH OF THE STATIONARY FRONT. THIS MEANS SEVERAL ADDITIONAL HOURS OF HOT SUNSHINE...AND TEMPERATURES HERE WILL RISE INTO THE MID TO UPPER 90S. FORECAST HEAT INDICES ARE JUST BELOW 105-DEGREE HEAT ADVISORY CRITERIA ACROSS GEORGETOWN...WILLIAMSBURG AND SOUTHERN FLORENCE COUNTIES. AN UPPER LEVEL DISTURBANCE CURRENTLY PRODUCING THUNDERSTORMS OVER CENTRAL TENNESSEE WILL REACH THE EASTERN CAROLINAS THIS EVENING. THIS COULD HELP CONVECTIVE ACTIVITY TO PERSIST INTO THE EVENING HOURS EVEN AFTER THE ATMOSPHERE PRETTY MUCH OVERTURNS DURING THE AFTERNOON. THE LOW WILL SCOOT EASTWARD ALONG THE FRONT OFFSHORE AFTER MIDNIGHT WITH SURFACE WINDS TURNING NORTHWESTERLY...QUITE AN ODD DIRECTION FOR THE CAROLINAS IN THE MIDDLE OF SUMMER. THIS IS THE THIRD COLD FRONTAL PASSAGE OF JULY! && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LATEST MODELS SHOW LOW JUST OFF THE CAPE FEAR COAST FRI MORNING. EXPECT BEST CONVECTION OVER THE COASTAL WATERS WITH MOST AREAS SEEING A DEEP FLOW OF DRIER AIR ADVECTING IN FROM THE NORTH. MID TO UPPER TROUGH WILL PUSH LOW PRESSURE ALONG LINGERING BOUNDARY SOUTH AND EAST OF AREA THROUGH THE DAY...BUT PLENTY OF RESIDUAL LOW LEVEL MOISTURE FROM PREVIOUS DAYS CONVECTION WILL SLOW CLEARING AND COMBINE WITH CONVERGENCE ASSOCIATED WITH LOW AND OTHER LOCALIZED BOUNDARIES SUCH AS THE SEA BREEZE TO PRODUCE SOME SHWRS/TSTMS. LOOKS LIKE BEST CHC WILL MOVE SOUTH THROUGH THE DAY AS HIGH PRESSURE BEGINS TO BUILD DOWN FROM THE NORTH BUT MAY NOT BE FAST ENOUGH TO ELIMINATE POPS FROM FORECAST. NAM SHOWS MAIN FOCUS OF CONVECTION ALONG COASTAL SOUTH CAROLINA WHERE BEST CONVERGENCE SHOULD BE AS WE DEVELOP A N-NE FLOW. MAY SEE ENOUGH SUBSIDENCE AND DRY AIR THROUGH THE MID TO UPPER LEVELS BY LATE FRI TO ALLOW FOR ONLY A DECENT STRATOCU FIELD OVER NC. PCP WATER VALUES OVER 2 INCHES EARLY FRI MORNING WILL DROP DOWN CLOSE TO AN INCH BY SAT MORNING. LINGERING CLOUDS AND PCP WILL KEEP TEMPS IN THE 80S MOST OF THE DAY BUT PLACES THAT SEE SOME SUN MAKE AN APPEARANCE WILL REACH CLOSE TO 90. BY LATE FRI INTO FRI NIGHT...PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID TO UPPER LEVELS WILL REACH DOWN OVER THE FORECAST AREA AS DRY HIGH PRESSURE AT THE SFC NOSES DOWN FROM THE NORTH. WILL SHOW CLEARING AT THIS TIME AND WILL KEEP PCP OUT OF FORECAST THROUGH THE REMAINDER OF THE WEEKEND. PLENTY OF BRIGHT JULY SUNSHINE WILL DRIVE TEMPS UP NEAR NORMAL...CLOSE TO 90 BUT SFC DEWPOINT TEMPS WILL BE RUNNING IN THE LOW TO MID 60S MOST PLACES WHICH WILL MAKE FOR A MUCH MORE REFRESHING DAY THAN PREVIOUS ONES. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM THURSDAY...CENTER OF HIGH PRESSURE NOSING DOWN FROM THE NORTH WILL SHIFT OFF THE MID ATLANTIC COAST ALLOWING WINDS TO COME AROUND TO A MORE ON SHORE NE TO E FLOW. WEAK HIGH PRESSURE WILL CONTINUE TO REACH DOWN INTO THE CAROLINAS THROUGH MID WEEK AS LEE SIDE TROUGH BECOMES MORE PRONOUNCED. RIDGING IN THE MID TO UPPER LEVELS OVER THE MID WEST WILL BUILD EASTWARD OVER THE WEEKEND...BUT AS IT BECOMES MORE AMPLIFIES UP THROUGH THE UPPER MIDWEST BY TUES...A DEEPER NW FLOW ALOFT WILL ALLOW SOME CLOUDS AND SHORTWAVE ENERGY TO SNEAK INTO AREA BUT RIDGE WILL BUILD BACK EAST AND UP THE EAST COAST THROUGH MID WEEK AND THEREFORE MAY INTRODUCE INCREASED CLOUDS AND SHWRS FOR TUES/WED TIME FRAME BUT OVERALL SHWR ACTIVITY SHOULD REMAIN MORE ISOLATED HEADING INTO MID WEEK AS RIDGE BUILDS BACK IN. THE ON SHORE FLOW DEVELOPING THROUGH THE PERIOD WILL AID IN BRINGING DEWPOINT TEMPS BACK UP CLOSER TO 70 OR SO...HELPING TO INCREASE AFTN CU AND CHC OF SOME CONVECTIVE DEVELOPMENT. TEMPS WILL BASICALLY REMAIN AROUND CLIMO. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 12Z...TERMINALS ARE CURRENTLY VFR ALTHOUGH SOME MVFR VSBYS IN BR COULD OCCUR MAINLY AT KLBT UNTIL 13Z. A WEAK FRONT IS LOCATED FROM NEAR KFLO TO KMYR. WINDS THIS MORNING WILL BE ESE-SE AT KILM/KLBT WITH S-SW WINDS ELSEWHERE. THUNDERSTORMS ARE A SURE BET TODAY AND WILL EVENTUALLY AFFECT EVERY TERMINAL. CONFIDENCE IN EXACT TIMING IS LOW BUT KLBT SHOULD BE INITIALLY AFFECTED BY LATE MORNING THEN KILM/KFLO TOWARDS EARLY AFTERNOON. KCRE/KMYR SHOULD BE AFFECTED MOSTLY IN THE AFTERNOON. TEMPO IFR WITH WIND GUSTS TO 35 KT POSSIBLE WITH THE STORMS. THUNDERSTORMS SHOULD END IN THE 21-00Z TIME FRAME WITH VFR LIKELY... BUT SHOWERS WILL POTENTIAL PERSIST INTO THE EVENING HOURS. WINDS BECOME LIGHT AND VARIABLE OR LIGHT NW LATE AFTERNOON AND EVENING. THERE IS A FOG POTENTIAL MAINLY KFLO/KLBT OVERNIGHT WITH LOW TO MODERATE POTENTIAL FOR IFR. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM ISOLATED CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 650 AM THURSDAY...LOW PRESSURE CENTERED OVER THE SOUTH CAROLINA SANDHILLS WILL MOVE EASTWARD TODAY ALONG A WEAK STATIONARY FRONT. THIS FRONT CURRENTLY SITS JUST NORTH OF CAPE FEAR AND IS OUTLINED BY A SHIFT IN WIND DIRECTIONS FROM SOUTHERLY ALONG THE SC COAST TO SOUTHEASTERLY FROM WRIGHTSVILLE BEACH AND SURF CITY TO THE OUTER BANKS. AS INLAND AREAS HEAT UP QUICKLY THIS MORNING ATMOSPHERIC CONDITIONS ARE STRONGLY SUPPORTIVE OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING ACROSS SOUTHERN NORTH CAROLINA...DROPPING SOUTHEASTWARD AND AFFECTING THE COASTAL WATERS DURING THE AFTERNOON. THESE STORMS WILL LIKELY CONTAIN LARGE AMOUNTS OF LIGHTNING AND SUBSTANTIAL VISIBILITY RESTRICTIONS IN HEAVY RAIN. SEVERAL OF THE HIGH- RESOLUTION MODELS INDICATE THE POTENTIAL FOR A STRONG GUST FRONT AT THE LEADING EDGE OF THE STORMS WHICH MAY PROMPT SPECIAL MARINE WARNINGS THIS AFTERNOON. MARINERS IN THE CAPE FEAR AREA SHOULD EXPECT THE LARGEST IMPACT FROM THESE STORMS BETWEEN 1-3 PM...WITH THE GRAND STAND AND GEORGETOWN AREAS A COUPLE HOURS LATER. LATE TONIGHT AS THE LOW SHIFTS EASTWARD ALONG THE FRONT AND ENTERS THE ATLANTIC OCEAN SURFACE WINDS WILL SHIFT NORTHWESTERLY AND MAY INCREASE TO 10-15 KT LATE. OUTSIDE OF THUNDERSTORMS SEAS SHOULD AVERAGE 2 FEET TODAY...AND 2-3 FEET TONIGHT. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LOW PRESSURE ALONG LINGERING BOUNDARY WILL SLIP FARTHER SOUTH THROUGH THE DAY ON FRIDAY. NORTHEAST FLOW WILL DEVELOP BEHIND THIS BOUNDARY AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH THROUGH THE WEEKEND. EXPECT WINDS TO REMAIN BELOW 15 KTS ACROSS MOST OF THE WATERS...BUT THERE SHOULD BE SOME PERIODS OF HIGHER WAVES...UP CLOSER TO 20 KTS. THE WINDS WILL BEGIN TO VEER AROUND FROM THE NE TO E. THE PERSISTENT STRONGER NE TO E ON SHORE FLOW WILL PRODUCE SEAS UP TO 3 TO 5 FT...ESPECIALLY THROUGH SAT NIGHT. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 330 AM...HIGH PRESSURE EXTENDING DOWN INTO THE CAROLINAS FROM THE NORTHEAST WILL MOVE FARTHER EAST THROUGH THE PERIOD...ALLOWING WINDS TO LIGHTEN AND VEER TO THE EAST. THE WINDS SHOULD DECREASE TO 10 KTS OR LESS MOST OF THE TIME...BUT SEA BREEZE EACH AFTN WILL ACT TO ENHANCE OVERALL ON SHORE FLOW. EXPECT SEAS TO BE COMING DOWN AS WINDS LIGHTEN HEADING THROUGH LATE SUNDAY INTO MONDAY. THEREFORE SEAS UP TO 3 TO 5 FT EARLY SUNDAY SHOULD DROP TO 2 TO 4 FT SUN NIGHT. AS SHORTER PERIOD WINDWAVE DIMINISHES THROUGH MONDAY AND WNA CONTINUES TO SHOW A LONGER PERIOD UP TO 11 SEC WAVE MIXING IN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...RGZ LONG TERM...RGZ AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
648 AM EDT THU JUL 23 2015 .SYNOPSIS... LOW PRESSURE OVER NORTHERN SOUTH CAROLINA WILL MOVE EAST ALONG A STALLED FRONT TODAY AND OFF THE COAST TONIGHT. THIS LOW WILL PUSH THE FRONT INTO GEORGIA FOR THIS WEEKEND. HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH...WITH A DRYING TREND EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 650 AM THURSDAY...LOW PRESSURE CENTERED OVER THE SC SANDHILLS WILL MOVE EASTWARD ALONG A STATIONARY FRONT TODAY...EXITING INTO THE ATLANTIC OCEAN TONIGHT. MODELS ARE ALMOST UNANIMOUS IN THEIR DEPICTION OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING WITHIN A REGION OF LOW-LEVEL CONVERGENCE AND LARGE INSTABILITY OVER SOUTHERN NORTH CAROLINA JUST NORTH OF THE STATIONARY FRONT LATE THIS MORNING. SURFACE CAPE IS PREDICTED TO GROW AS LARGE AS 3000 J/KG WITH LIFTED INDICES TO -6. 700 MB WINDS INCREASING TO 25 KT SHOULD INCREASE BULK SHEAR VALUES JUST ENOUGH TO PRODUCE ORGANIZED MULTICELLULAR STORMS TODAY...WITH COLD POOL EFFECTS LIKELY PUSHING THE CLUSTER SOUTHEASTWARD ACROSS THE CAPE FEAR AREA EARLY THIS AFTERNOON AND INTO NORTHEASTERLY SOUTH CAROLINA BY MID TO LATE AFTERNOON. IMPACTS FROM THESE STORMS COULD BE CONSIDERABLE. COMPUTED EQUILIBRIUM PARCEL HEIGHTS NEAR 50000 FT AND LOTS OF INSTABILITY ABOVE THE -20C LEVEL INDICATES THESE STORMS COULD BE ENORMOUS LIGHTNING PRODUCERS WITH PLENTY OF ICE/GRAUPEL GENERATION ALOFT. ALTHOUGH NO DRY LAYERS ARE EVIDENT IN FORECAST SOUNDINGS PRECIPITATION LOADING RESULTING FROM SUCH VIGOROUS CONVECTION SHOULD PRODUCE GUSTY WINDS...PARTICULARLY AS THE STORMS ARE SHOWN IN THE HIGH RESOLUTION WRF-NMM...WRF-ARW...AND HRRR MODELS TO FORM A LARGE MASSED OUTFLOW PUSHING SOUTHEASTWARD TO THE COAST. WITH THE SYNOPTIC FRONT STALLED ACROSS THE AREA AND ANTICIPATED BOUNDARY COLLISIONS THE STORMS SHOULD ALSO BE HEAVY RAIN MAKERS WITH LOCALIZED FLOODING POSSIBLE. FORECAST RAIN CHANCES HAVE BEEN INCREASED TO 80 PERCENT ACROSS SE NORTH CAROLINA...FOCUSED ON THE NOON-4 PM TIMEFRAME. CONVECTION SHOULD TAKE SEVERAL ADDITIONAL HOURS TO PROPAGATE SOUTHWARD AND AFFECT NE SOUTH CAROLINA WHICH WILL BE LOCATED SOUTH OF THE STATIONARY FRONT. THIS MEANS SEVERAL ADDITIONAL HOURS OF HOT SUNSHINE...AND TEMPERATURES HERE WILL RISE INTO THE MID TO UPPER 90S. FORECAST HEAT INDICES ARE JUST BELOW 105-DEGREE HEAT ADVISORY CRITERIA ACROSS GEORGETOWN...WILLIAMSBURG AND SOUTHERN FLORENCE COUNTIES. AN UPPER LEVEL DISTURBANCE CURRENTLY PRODUCING THUNDERSTORMS OVER CENTRAL TENNESSEE WILL REACH THE EASTERN CAROLINAS THIS EVENING. THIS COULD HELP CONVECTIVE ACTIVITY TO PERSIST INTO THE EVENING HOURS EVEN AFTER THE ATMOSPHERE PRETTY MUCH OVERTURNS DURING THE AFTERNOON. THE LOW WILL SCOOT EASTWARD ALONG THE FRONT OFFSHORE AFTER MIDNIGHT WITH SURFACE WINDS TURNING NORTHWESTERLY...QUITE AN ODD DIRECTION FOR THE CAROLINAS IN THE MIDDLE OF SUMMER. THIS IS THE THIRD COLD FRONTAL PASSAGE OF JULY! && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LATEST MODELS SHOW LOW JUST OFF THE CAPE FEAR COAST FRI MORNING. EXPECT BEST CONVECTION OVER THE COASTAL WATERS WITH MOST AREAS SEEING A DEEP FLOW OF DRIER AIR ADVECTING IN FROM THE NORTH. MID TO UPPER TROUGH WILL PUSH LOW PRESSURE ALONG LINGERING BOUNDARY SOUTH AND EAST OF AREA THROUGH THE DAY...BUT PLENTY OF RESIDUAL LOW LEVEL MOISTURE FROM PREVIOUS DAYS CONVECTION WILL SLOW CLEARING AND COMBINE WITH CONVERGENCE ASSOCIATED WITH LOW AND OTHER LOCALIZED BOUNDARIES SUCH AS THE SEA BREEZE TO PRODUCE SOME SHWRS/TSTMS. LOOKS LIKE BEST CHC WILL MOVE SOUTH THROUGH THE DAY AS HIGH PRESSURE BEGINS TO BUILD DOWN FROM THE NORTH BUT MAY NOT BE FAST ENOUGH TO ELIMINATE POPS FROM FORECAST. NAM SHOWS MAIN FOCUS OF CONVECTION ALONG COASTAL SOUTH CAROLINA WHERE BEST CONVERGENCE SHOULD BE AS WE DEVELOP A N-NE FLOW. MAY SEE ENOUGH SUBSIDENCE AND DRY AIR THROUGH THE MID TO UPPER LEVELS BY LATE FRI TO ALLOW FOR ONLY A DECENT STRATOCU FIELD OVER NC. PCP WATER VALUES OVER 2 INCHES EARLY FRI MORNING WILL DROP DOWN CLOSE TO AN INCH BY SAT MORNING. LINGERING CLOUDS AND PCP WILL KEEP TEMPS IN THE 80S MOST OF THE DAY BUT PLACES THAT SEE SOME SUN MAKE AN APPEARANCE WILL REACH CLOSE TO 90. BY LATE FRI INTO FRI NIGHT...PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID TO UPPER LEVELS WILL REACH DOWN OVER THE FORECAST AREA AS DRY HIGH PRESSURE AT THE SFC NOSES DOWN FROM THE NORTH. WILL SHOW CLEARING AT THIS TIME AND WILL KEEP PCP OUT OF FORECAST THROUGH THE REMAINDER OF THE WEEKEND. PLENTY OF BRIGHT JULY SUNSHINE WILL DRIVE TEMPS UP NEAR NORMAL...CLOSE TO 90 BUT SFC DEWPOINT TEMPS WILL BE RUNNING IN THE LOW TO MID 60S MOST PLACES WHICH WILL MAKE FOR A MUCH MORE REFRESHING DAY THAN PREVIOUS ONES. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM THURSDAY...CENTER OF HIGH PRESSURE NOSING DOWN FROM THE NORTH WILL SHIFT OFF THE MID ATLANTIC COAST ALLOWING WINDS TO COME AROUND TO A MORE ON SHORE NE TO E FLOW. WEAK HIGH PRESSURE WILL CONTINUE TO REACH DOWN INTO THE CAROLINAS THROUGH MID WEEK AS LEE SIDE TROUGH BECOMES MORE PRONOUNCED. RIDGING IN THE MID TO UPPER LEVELS OVER THE MID WEST WILL BUILD EASTWARD OVER THE WEEKEND...BUT AS IT BECOMES MORE AMPLIFIES UP THROUGH THE UPPER MIDWEST BY TUES...A DEEPER NW FLOW ALOFT WILL ALLOW SOME CLOUDS AND SHORTWAVE ENERGY TO SNEAK INTO AREA BUT RIDGE WILL BUILD BACK EAST AND UP THE EAST COAST THROUGH MID WEEK AND THEREFORE MAY INTRODUCE INCREASED CLOUDS AND SHWRS FOR TUES/WED TIME FRAME BUT OVERALL SHWR ACTIVITY SHOULD REMAIN MORE ISOLATED HEADING INTO MID WEEK AS RIDGE BUILDS BACK IN. THE ON SHORE FLOW DEVELOPING THROUGH THE PERIOD WILL AID IN BRINGING DEWPOINT TEMPS BACK UP CLOSER TO 70 OR SO...HELPING TO INCREASE AFTN CU AND CHC OF SOME CONVECTIVE DEVELOPMENT. TEMPS WILL BASICALLY REMAIN AROUND CLIMO. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 06Z...LOOKS LIKE THERE WILL BE LITTLE BEFORE SUNRISE. THE WEAK MCS WEST OF THE AREA DID NOT MAKE IT. WITH LITTLE IN CONVECTIVE DEBRIS...TEMPO MVFR FOG IS A GOOD BET AFTER 08Z. THE FRONT WAVES BACK TO THE NORTH AROUND DAYBREAK WITH MOISTURE INCREASING LATER IN THE MORNING. TIMING OF THE CONVECTION WILL BE AN ISSUE...BUT IT IS SAFE TO SAY THAT SHOWERS AND STORMS WILL BE AROUND TODAY...POSSIBLY NUMEROUS AS DEEP MOISTURE MOVES BACK OVER THE REGION. LOW PRESSURE FORMING ALONG THE FRONT SHOULD ENHANCE PRECIPITATION. THERE SHOULD BE MINIMAL CONVECTIVE INHIBITION...A CHANGE FROM THE PREVIOUS WEEK...WITH CONVECTION EXPECTED TO BEGIN WITH ONLY MINIMAL HEATING...BY MIDDAY. SOME BRIEF IFR CONDITIONS ARE LIKELY IN THE HEAVIEST ACTIVITY. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM ISOLATED CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 650 AM THURSDAY...LOW PRESSURE CENTERED OVER THE SOUTH CAROLINA SANDHILLS WILL MOVE EASTWARD TODAY ALONG A WEAK STATIONARY FRONT. THIS FRONT CURRENTLY SITS JUST NORTH OF CAPE FEAR AND IS OUTLINED BY A SHIFT IN WIND DIRECTIONS FROM SOUTHERLY ALONG THE SC COAST TO SOUTHEASTERLY FROM WRIGHTSVILLE BEACH AND SURF CITY TO THE OUTER BANKS. AS INLAND AREAS HEAT UP QUICKLY THIS MORNING ATMOSPHERIC CONDITIONS ARE STRONGLY SUPPORTIVE OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING ACROSS SOUTHERN NORTH CAROLINA...DROPPING SOUTHEASTWARD AND AFFECTING THE COASTAL WATERS DURING THE AFTERNOON. THESE STORMS WILL LIKELY CONTAIN LARGE AMOUNTS OF LIGHTNING AND SUBSTANTIAL VISIBILITY RESTRICTIONS IN HEAVY RAIN. SEVERAL OF THE HIGH- RESOLUTION MODELS INDICATE THE POTENTIAL FOR A STRONG GUST FRONT AT THE LEADING EDGE OF THE STORMS WHICH MAY PROMPT SPECIAL MARINE WARNINGS THIS AFTERNOON. MARINERS IN THE CAPE FEAR AREA SHOULD EXPECT THE LARGEST IMPACT FROM THESE STORMS BETWEEN 1-3 PM...WITH THE GRAND STAND AND GEORGETOWN AREAS A COUPLE HOURS LATER. LATE TONIGHT AS THE LOW SHIFTS EASTWARD ALONG THE FRONT AND ENTERS THE ATLANTIC OCEAN SURFACE WINDS WILL SHIFT NORTHWESTERLY AND MAY INCREASE TO 10-15 KT LATE. OUTSIDE OF THUNDERSTORMS SEAS SHOULD AVERAGE 2 FEET TODAY...AND 2-3 FEET TONIGHT. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LOW PRESSURE ALONG LINGERING BOUNDARY WILL SLIP FARTHER SOUTH THROUGH THE DAY ON FRIDAY. NORTHEAST FLOW WILL DEVELOP BEHIND THIS BOUNDARY AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH THROUGH THE WEEKEND. EXPECT WINDS TO REMAIN BELOW 15 KTS ACROSS MOST OF THE WATERS...BUT THERE SHOULD BE SOME PERIODS OF HIGHER WAVES...UP CLOSER TO 20 KTS. THE WINDS WILL BEGIN TO VEER AROUND FROM THE NE TO E. THE PERSISTENT STRONGER NE TO E ON SHORE FLOW WILL PRODUCE SEAS UP TO 3 TO 5 FT...ESPECIALLY THROUGH SAT NIGHT. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 330 AM...HIGH PRESSURE EXTENDING DOWN INTO THE CAROLINAS FROM THE NORTHEAST WILL MOVE FARTHER EAST THROUGH THE PERIOD...ALLOWING WINDS TO LIGHTEN AND VEER TO THE EAST. THE WINDS SHOULD DECREASE TO 10 KTS OR LESS MOST OF THE TIME...BUT SEA BREEZE EACH AFTN WILL ACT TO ENHANCE OVERALL ON SHORE FLOW. EXPECT SEAS TO BE COMING DOWN AS WINDS LIGHTEN HEADING THROUGH LATE SUNDAY INTO MONDAY. THEREFORE SEAS UP TO 3 TO 5 FT EARLY SUNDAY SHOULD DROP TO 2 TO 4 FT SUN NIGHT. AS SHORTER PERIOD WINDWAVE DIMINISHES THROUGH MONDAY AND WNA CONTINUES TO SHOW A LONGER PERIOD UP TO 11 SEC WAVE MIXING IN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...RGZ LONG TERM...RGZ AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
612 AM CDT Thu Jul 23 2015 .AVIATION... /12Z TAFS/ Patchy MVFR stratus will persist across the northwest Hill Country this morning, potentially affecting the KJCT terminal. This stratus will erode by mid-morning with a high based cu field anticipated this afternoon. A few showers will occur to the west and northwest of KSWW, but will amount to little. Otherwise, dry weather is expected across the area through the next 24 hours with south winds around 10 kts. 25 && .PREV DISCUSSION... /ISSUED 324 AM CDT Thu Jul 23 2015/ SHORT TERM... (Today and tonight) The development of mid-level cumuliform clouds from Midland, to Haskell, to Albany over the past few hours implies a region of ascent moving across West TX. The TTU WRF and HRRR are hinting at the potential for a few showers early this morning, but anything that develops should remain west of Sweetwater. Farther south, low stratus over the Hill County is increasing in coverage and advecting north. This cloud cover will likely affect the southeast portion of the CWA through around 9 AM. Otherwise, expect hot and dry conditions across West Central TX with afternoon highs in the upper 90s to around 101 degrees. Skies will be mostly clear tonight, although a few low clouds will be possible along the I-10 corridor after 3 AM. Winds will remain under 10 mph with overnight lows in the mid 70s. Johnson LONG TERM... (Friday through Wednesday) No relief in sight from the heat in the extended forecast. Temperatures may even get a degree or two hotter this weekend as the center of upper level high pressure moves back over West Texas, with highs in the 99 to 102 range. && .PRELIMINARY POINT TEMPS/POPS... Abilene 99 77 98 77 99 / 0 0 0 5 5 San Angelo 101 76 101 76 102 / 0 0 0 5 5 Junction 99 75 97 75 99 / 0 0 0 5 5 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 25
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1002 AM EDT THU JUL 23 2015 .SYNOPSIS... A STALLED FRONT WILL REMAIN SOUTH OF THE REGION FRIDAY. WEAK WAVES OF LOW PRESSURE WILL TRACK ALONG THE FRONT TODAY AND TONIGHT...WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST ON FRIDAY. HIGH PRESSURE WILL STRENGTHEN FRIDAY THROUGH THE WEEKEND OVER THE MID ATLANTIC REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1055 AM EDT THURSDAY... MORNING UPDATE WILL REFLECT A MORE DISTINCT SEPARATION IN PRECIPITATION COVERAGE ACROSS THE REGION. CURRENTLY RAIN SHOWERS ARE EXITING THE SOUTHEAST PART OF THE REGION TO THE EAST...WITH NO OTHER PRECIPITATION IN THE AREA. THEREFORE..HAVE REMOVED THE PRECIPITATION CHANCES IN THE SOUTHWEST PARTS OF THE AREA UNTIL IT HAS A CHANCE TO MOVE INTO REGION THIS AFTERNOON FROM THE WEST. HAVE ALSO ADJUSTED HOURLY TEMPERATURE...DEW POINT AND SKY COVER GRIDS THROUGH THE NEXT FEW HOURS BASED UPON THE CURRENT OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY AFTERNOON. AS OF 650 AM EDT THURSDAY... SHORT WAVE WAS OVER THE MID MISSISSIPPI VALLEY EARLY THIS MORNING ND WILL TRACK INTO THE CAROLINA BY FRIDAY MORNING. THE ASSOCIATED PRECIPITATION WAS OVER TENNESSEE AND KENTUCKY AT 08Z. MODELS BRING THE PRECIPITATION EAST ALONG THE 850 MB FRONT. LITTLE MOVEMENT OF THE SURFACE FRONT IS EXPECTED TODAY AND INTO THIS EVENING. SURFACE WINDS WILL BE LIGHT AND VARIABLE UNTIL THE SHORT WAVE MOVES TO THE EAST...THEN PREVAILING FLOW WILL BE OUT OF THE NORTHEAST. UNTIL THEN COUNTY WARNING AREA IS IN BETWEEN THE FRONT OVER THE CAROLINAS AND HIGH PRESSURE OVER THE OHIO VALLEY. HAVE RAISED PROBABILITY OF PRECIPITATION TO ACCOUNT BASED ON RADAR TRENDS. HRRR AND LOCAL WRF BRING NEXT BATCH OF PRECIPITATION IN AFTER 15Z/10AM. MODELS SIMILAR WITH NORTHERN EXTENT OF THE BEST PROBABILITY OF PRECIPITATION. HIGHER CONVECTIVE AVAILABLE POTENTIAL ENERGY AND LOWER LIFTED INDEX VALUES WILL BE ALONG AND SOUTH OF ROUTE 460. WILL KEEP HIGHEST PROBABILITY OF PRECIPITATION IN THE SOUTHERN HALF OF THE FORECAST AREA THIS AFTERNOON AND EVENING. THIS ALSO LINES UP WITH PRECIPITABLE WATER VALUES OF 1.5 TO 2.0 INCHES. THIS DEEPER MOISTURE BEGINS TO EXIT SOUTHEAST OUT OF THE FORECAST AREA LATE TONIGHT. HOWEVER...NORTHEAST WINDS AND LOW LEVEL MOISTURE WILL KEEP LOW CLOUDS AND FOG IN THE REGION...ESPECIALLY IN THE EASTERN UPSLOPE AREA OF THE APPALACHIANS. DRIER AIR COMING IN THE NORTH ERN COUNTY WARNING AREA AND LESS CLOUD COVER COMPARED TO MORE CLOUDS IN THE CENTRAL AND SOUTHERN COUNTY WARNING AREA WILL RESULT IN A LARGE SPREAD OF MINIMUM TEMPERATURES. DO NOT EXPECT AS MUCH OF A DROP I N HE SOUTH...WHILE NORTHERN COUNTIES MAY LOWER INTO THE 50S. LOCAL WRF GUIDANCE LOOKED REASONABLE FOR LOWS TONIGHT. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM EDT THURSDAY... LOW PRESSURE JUST OFF THE NORTH CAROLINA COAST FRIDAY MORNING WILL MOVE EAST INTO THE ATLANTIC OCEAN THROUGH THE PERIOD. MEANWHILE HIGH PRESSURE TO OUR NORTHWEST WILL BUILD SOUTH ON FRIDAY AND MOVE ACROSS THE MID ATLANTIC REGION INTO SATURDAY NIGHT. THE COMBINATION OF HEATING...DESTABILIZATION...MOISTURE SFC FLOW OVER HIGHER TERRAIN SUPPORTS THE MENTION OF ISOLATED TO WIDELY SCATTERED CONVECTION CROSS THE SOUTHWEST. HIGH TEMPERATURES FRIDAY WILL CLIMB TO NEAR 80 DEGREES IN THE WEST TO THE UPPER 80S IN THE EAST. TAPER OFF ISOLATED SHOWERS FRIDAY NIGHT BY MIDNIGHT AND ADDED SOME PATCHY FOG FRIDAY NIGHT INTO SATURDAY MORNING. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 50S IN THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT. EXPECT A NICE SATURDAY WITH ONLY AN ISOLATED CHANCE OF SHOWERS ACROSS THE MOUNTAINS. HIGH TEMPERATURES SATURDAY WILL MODERATE INTO THE LOWER 80S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. YOU CAN ANTICIPATE DRY WEATHER FOR SATURDAY NIGHT WITH LOW TEMPERATURES FROM THE LOWER 60S IN THE WEST TO THE MID 60S IN THE EAST. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 240 PM EDT WEDNESDAY... GOING TO UPPER RIDGE START TO LEAN WEST TO EAST ACROSS THE SOUTHERN PLAINS TO THE APPALACHIANS THIS PERIOD WITH GRADUALLY BUILDING HEIGHTS. OUR REGION WILL STAY IN A NW FLOW ALOFT THIS SUNDAY THEN MORE NORTHERLY BY TUESDAY-WEDNESDAY. MEAN SOLUTION OF MODELS SUGGEST NOT BIG THREAT OF CONVECTION THIS PERIOD...THOUGH BEST SHOT WILL BE PERHAPS MONDAY AS SHORTWAVE MOVES FROM OHIO TO THE MID ATLANTIC SETTING UP SOME HEIGHT FALLS OVER VIRGINIA...AND WEAK FRONTAL BOUNDARY PASSING ACROSS. AT THIS TIME WILL MAINTAIN IN THE CHANCE RANGE FOR POPS. WILL START TO SEE HUMIDITY ELEVATE ONCE AGAIN WITH BUILDING HEIGHTS AND LIGHT SOUTHEAST TO SOUTHWEST WINDS IN THE SFC TO LOW LVLS. HIGHS AND LOWS WILL BE CLOSE TO NORMAL FOR LATE JULY WITH MID 60S MOUNTAINS TO AROUND 70 PIEDMONT FOR LOWS...AND HIGHS IN THE LOWER TO MID 80S MOUNTAINS TO AROUND 90 PIEDMONT...INCLUDING ROANOKE CITY. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... AS OF 735 AM EDT THURSDAY... BASED ON THE LATEST RADAR TRENDS AND WATER VAPOR SATELLITE LOOP...SCATTERED SHOWERS WILL MOVE ACROSS NORTHERN NORTH CAROLINA AND EXTREME SOUTHERN VIRGINIA THIS MORNING. HOWEVER...VISIBILITIES WILL REMAIN VFR....EVEN WITH THE RAIN...AT KLYH AND KDAN. A SHORT WAVE OVER MISSOURI EARLY THIS MORNING WILL TRACK INTO THE CAROLINAS BY FRIDAY MORNING. THE ASSOCIATED SHOWERS AND THUNDERSTORMS OVER KENTUCKY AND TENNESSEE WILL MOVE EAST BRINGING MORE PRECIPITATION TO SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA BY EARLY THIS AFTERNOON. MODELS IN DECENT AGREEMENT THAT NORTHERN EDGE OF THE PRECIPITATION CHANCE WILL STAY JUST SOUTH OF KBLF/KROA/KLYH. KDAN HAS THE BEST CHANCE OF SHOWERS TODAY...WHICH MAY RESULT IN BRIEF MVFR CONDITIONS. OTHERWISE CEILINGS AND VISIBILITIES WILL BE VFR. THE FRONT AND DEEP MOISTURE PUSH SOUTH OUT OF THE AREA TONIGHT. SURFACE AND LOW LEVEL WINDS BECOME EAST TO NORTHEAST TONIGHT. THIS WILL BRING MOISTURE UP AGAINST THE EAST SLOPES OF THE APPALACHIANS. HAVE ADDED MVFR FOG AND CLOUDS IN FOR KROA/KDAN AND KLYH AFTER MIDNIGHT. MEDIUM CONFIDENCE ON THESE CEILING HEIGHTS...MAY END UP BEING MUCH LOWER. EXTENDED AVIATION FORECAST... FRIDAY THROUGH EARLY NEXT WEEK...HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE ACROSS THE REGION. MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT FOR THE POTENTIAL OF LATE NIGHT AND EARLY MORNING MOUNTAIN VALLEY FOG. ISOLATED SHOWERS AND STORMS CANNOT BE RULED OUT...ESPECIALLY OVER THE MOUNTAINS ON SUNDAY AFTERNOON. A WEAK BACKDOOR FRONT MAY ENTER THE REGION LATE SUNDAY NIGHT INTO MONDAY. THIS WOULD EXPAND SHOWER AND THUNDERSTORMS COVERAGE MONDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...KK LONG TERM...WP AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
737 AM EDT THU JUL 23 2015 .SYNOPSIS... A STALLED FRONT WILL REMAIN SOUTH OF THE REGION FRIDAY. WEAK WAVES OF LOW PRESSURE WILL TRACK ALONG THE FRONT TODAY AND TONIGHT...WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST ON FRIDAY. HIGH PRESSURE WILL STRENGTHEN FRIDAY THROUGH THE WEEKEND OVER THE MID ATLANTIC REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 650 AM EDT THURSDAY... SHORT WAVE WAS OVER THE MID MISSISSIPPI VALLEY EARLY THIS MORNING ND WILL TRACK INTO THE CAROLINA BY FRIDAY MORNING. THE ASSOCIATED PRECIPITATION WAS OVER TENNESSEE AND KENTUCKY AT 08Z. MODELS BRING THE PRECIPITATION EAST ALONG THE 850 MB FRONT. LITTLE MOVEMENT OF THE SURFACE FRONT IS EXPECTED TODAY AND INTO THIS EVENING. SURFACE WINDS WILL BE LIGHT AND VARIABLE UNTIL THE SHORT WAVE MOVES TO THE EAST...THEN PREVAILING FLOW WILL BE OUT OF THE NORTHEAST. UNTIL THEN COUNTY WARNING AREA IS IN BETWEEN THE FRONT OVER THE CAROLINAS AND HIGH PRESSURE OVER THE OHIO VALLEY. HAVE RAISED PROBABILITY OF PRECIPITATION TO ACCOUNT BASED ON RADAR TRENDS. HRRR AND LOCAL WRF BRING NEXT BATCH OF PRECIPITATION IN AFTER 15Z/10AM. MODELS SIMILAR WITH NORTHERN EXTENT OF THE BEST PROBABILITY OF PRECIPITATION. HIGHER CONVECTIVE AVAILABLE POTENTIAL ENERGY AND LOWER LIFTED INDEX VALUES WILL BE ALONG AND SOUTH OF ROUTE 460. WILL KEEP HIGHEST PROBABILITY OF PRECIPITATION IN THE SOUTHERN HALF OF THE FORECAST AREA THIS AFTERNOON AND EVENING. THIS ALSO LINES UP WITH PRECIPITABLE WATER VALUES OF 1.5 TO 2.0 INCHES. THIS DEEPER MOISTURE BEGINS TO EXIT SOUTHEAST OUT OF THE FORECAST AREA LATE TONIGHT. HOWEVER...NORTHEAST WINDS AND LOW LEVEL MOISTURE WILL KEEP LOW CLOUDS AND FOG IN THE REGION...ESPECIALLY IN THE EASTERN UPSLOPE AREA OF THE APPALACHIANS. DRIER AIR COMING IN THE NORTH ERN COUNTY WARNING AREA AND LESS CLOUD COVER COMPARED TO MORE CLOUDS IN THE CENTRAL AND SOUTHERN COUNTY WARNING AREA WILL RESULT IN A LARGE SPREAD OF MINIMUM TEMPERATURES. DO NOT EXPECT AS MUCH OF A DROP I N HE SOUTH...WHILE NORTHERN COUNTIES MAY LOWER INTO THE 50S. LOCAL WRF GUIDANCE LOOKED REASONABLE FOR LOWS TONIGHT. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM EDT THURSDAY... LOW PRESSURE JUST OFF THE NORTH CAROLINA COAST FRIDAY MORNING WILL MOVE EAST INTO THE ATLANTIC OCEAN THROUGH THE PERIOD. MEANWHILE HIGH PRESSURE TO OUR NORTHWEST WILL BUILD SOUTH ON FRIDAY AND MOVE ACROSS THE MID ATLANTIC REGION INTO SATURDAY NIGHT. THE COMBINATION OF HEATING...DESTABILIZATION...MOISTURE SFC FLOW OVER HIGHER TERRAIN SUPPORTS THE MENTION OF ISOLATED TO WIDELY SCATTERED CONVECTION CROSS THE SOUTHWEST. HIGH TEMPERATURES FRIDAY WILL CLIMB TO NEAR 80 DEGREES IN THE WEST TO THE UPPER 80S IN THE EAST. TAPER OFF ISOLATED SHOWERS FRIDAY NIGHT BY MIDNIGHT AND ADDED SOME PATCHY FOG FRIDAY NIGHT INTO SATURDAY MORNING. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 50S IN THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT. EXPECT A NICE SATURDAY WITH ONLY AN ISOLATED CHANCE OF SHOWERS ACROSS THE MOUNTAINS. HIGH TEMPERATURES SATURDAY WILL MODERATE INTO THE LOWER 80S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. YOU CAN ANTICIPATE DRY WEATHER FOR SATURDAY NIGHT WITH LOW TEMPERATURES FROM THE LOWER 60S IN THE WEST TO THE MID 60S IN THE EAST. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 240 PM EDT WEDNESDAY... GOING TO UPPER RIDGE START TO LEAN WEST TO EAST ACROSS THE SOUTHERN PLAINS TO THE APPALACHIANS THIS PERIOD WITH GRADUALLY BUILDING HEIGHTS. OUR REGION WILL STAY IN A NW FLOW ALOFT THIS SUNDAY THEN MORE NORTHERLY BY TUESDAY-WEDNESDAY. MEAN SOLUTION OF MODELS SUGGEST NOT BIG THREAT OF CONVECTION THIS PERIOD...THOUGH BEST SHOT WILL BE PERHAPS MONDAY AS SHORTWAVE MOVES FROM OHIO TO THE MID ATLANTIC SETTING UP SOME HEIGHT FALLS OVER VIRGINIA...AND WEAK FRONTAL BOUNDARY PASSING ACROSS. AT THIS TIME WILL MAINTAIN IN THE CHANCE RANGE FOR POPS. WILL START TO SEE HUMIDITY ELEVATE ONCE AGAIN WITH BUILDING HEIGHTS AND LIGHT SOUTHEAST TO SOUTHWEST WINDS IN THE SFC TO LOW LVLS. HIGHS AND LOWS WILL BE CLOSE TO NORMAL FOR LATE JULY WITH MID 60S MOUNTAINS TO AROUND 70 PIEDMONT FOR LOWS...AND HIGHS IN THE LOWER TO MID 80S MOUNTAINS TO AROUND 90 PIEDMONT...INCLUDING ROANOKE CITY. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 735 AM EDT THURSDAY... BASED ON THE LATEST RADAR TRENDS AND WATER VAPOR SATELLITE LOOP...SCATTERED SHOWERS WILL MOVE ACROSS NORTHERN NORTH CAROLINA AND EXTREME SOUTHERN VIRGINIA THIS MORNING. HOWEVER...VISIBILITIES WILL REMAIN VFR....EVEN WITH THE RAIN...AT KLYH AND KDAN. A SHORT WAVE OVER MISSOURI EARLY THIS MORNING WILL TRACK INTO THE CAROLINAS BY FRIDAY MORNING. THE ASSOCIATED SHOWERS AND THUNDERSTORMS OVER KENTUCKY AND TENNESSEE WILL MOVE EAST BRINGING MORE PRECIPITATION TO SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA BY EARLY THIS AFTERNOON. MODELS IN DECENT AGREEMENT THAT NORTHERN EDGE OF THE PRECIPITATION CHANCE WILL STAY JUST SOUTH OF KBLF/KROA/KLYH. KDAN HAS THE BEST CHANCE OF SHOWERS TODAY...WHICH MAY RESULT IN BRIEF MVFR CONDITIONS. OTHERWISE CEILINGS AND VISIBILITIES WILL BE VFR. THE FRONT AND DEEP MOISTURE PUSH SOUTH OUT OF THE AREA TONIGHT. SURFACE AND LOW LEVEL WINDS BECOME EAST TO NORTHEAST TONIGHT. THIS WILL BRING MOISTURE UP AGAINST THE EAST SLOPES OF THE APPALACHIANS. HAVE ADDED MVFR FOG AND CLOUDS IN FOR KROA/KDAN AND KLYH AFTER MIDNIGHT. MEDIUM CONFIDENCE ON THESE CEILING HEIGHTS...MAY END UP BEING MUCH LOWER. EXTENDED AVIATION FORECAST... FRIDAY THROUGH EARLY NEXT WEEK...HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE ACROSS THE REGION. MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT FOR THE POTENTIAL OF LATE NIGHT AND EARLY MORNING MOUNTAIN VALLEY FOG. ISOLATED SHOWERS AND STORMS CANNOT BE RULED OUT...ESPECIALLY OVER THE MOUNTAINS ON SUNDAY AFTERNOON. A WEAK BACKDOOR FRONT MAY ENTER THE REGION LATE SUNDAY NIGHT INTO MONDAY. THIS WOULD EXPAND SHOWER AND THUNDERSTORMS COVERAGE MONDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...WP AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
650 AM EDT THU JUL 23 2015 .SYNOPSIS... A STALLED FRONT WILL REMAIN SOUTH OF THE REGION FRIDAY. WEAK WAVES OF LOW PRESSURE WILL TRACK ALONG THE FRONT TODAY AND TONIGHT...WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST ON FRIDAY. HIGH PRESSURE WILL STRENGTHEN FRIDAY THROUGH THE WEEKEND OVER THE MID ATLANTIC REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 650 AM EDT THURSDAY... SHORT WAVE WAS OVER THE MID MISSISSIPPI VALLEY EARLY THIS MORNING ND WILL TRACK INTO THE CAROLINA BY FRIDAY MORNING. THE ASSOCIATED PRECIPITATION WAS OVER TENNESSEE AND KENTUCKY AT 08Z. MODELS BRING THE PRECIPITATION EAST ALONG THE 850 MB FRONT. LITTLE MOVEMENT OF THE SURFACE FRONT IS EXPECTED TODAY AND INTO THIS EVENING. SURFACE WINDS WILL BE LIGHT AND VARIABLE UNTIL THE SHORT WAVE MOVES TO THE EAST...THEN PREVAILING FLOW WILL BE OUT OF THE NORTHEAST. UNTIL THEN COUNTY WARNING AREA IS IN BETWEEN THE FRONT OVER THE CAROLINAS AND HIGH PRESSURE OVER THE OHIO VALLEY. HAVE RAISED PROBABILITY OF PRECIPITATION TO ACCOUNT BASED ON RADAR TRENDS. HRRR AND LOCAL WRF BRING NEXT BATCH OF PRECIPITATION IN AFTER 15Z/10AM. MODELS SIMILAR WITH NORTHERN EXTENT OF THE BEST PROBABILITY OF PRECIPITATION. HIGHER CONVECTIVE AVAILABLE POTENTIAL ENERGY AND LOWER LIFTED INDEX VALUES WILL BE ALONG AND SOUTH OF ROUTE 460. WILL KEEP HIGHEST PROBABILITY OF PRECIPITATION IN THE SOUTHERN HALF OF THE FORECAST AREA THIS AFTERNOON AND EVENING. THIS ALSO LINES UP WITH PRECIPITABLE WATER VALUES OF 1.5 TO 2.0 INCHES. THIS DEEPER MOISTURE BEGINS TO EXIT SOUTHEAST OUT OF THE FORECAST AREA LATE TONIGHT. HOWEVER...NORTHEAST WINDS AND LOW LEVEL MOISTURE WILL KEEP LOW CLOUDS AND FOG IN THE REGION...ESPECIALLY IN THE EASTERN UPSLOPE AREA OF THE APPALACHIANS. DRIER AIR COMING IN THE NORTH ERN COUNTY WARNING AREA AND LESS CLOUD COVER COMPARED TO MORE CLOUDS IN THE CENTRAL AND SOUTHERN COUNTY WARNING AREA WILL RESULT IN A LARGE SPREAD OF MINIMUM TEMPERATURES. DO NOT EXPECT AS MUCH OF A DROP I N HE SOUTH...WHILE NORTHERN COUNTIES MAY LOWER INTO THE 50S. LOCAL WRF GUIDANCE LOOKED REASONABLE FOR LOWS TONIGHT. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM EDT THURSDAY... LOW PRESSURE JUST OFF THE NORTH CAROLINA COAST FRIDAY MORNING WILL MOVE EAST INTO THE ATLANTIC OCEAN THROUGH THE PERIOD. MEANWHILE HIGH PRESSURE TO OUR NORTHWEST WILL BUILD SOUTH ON FRIDAY AND MOVE ACROSS THE MID ATLANTIC REGION INTO SATURDAY NIGHT. THE COMBINATION OF HEATING...DESTABILIZATION...MOISTURE SFC FLOW OVER HIGHER TERRAIN SUPPORTS THE MENTION OF ISOLATED TO WIDELY SCATTERED CONVECTION CROSS THE SOUTHWEST. HIGH TEMPERATURES FRIDAY WILL CLIMB TO NEAR 80 DEGREES IN THE WEST TO THE UPPER 80S IN THE EAST. TAPER OFF ISOLATED SHOWERS FRIDAY NIGHT BY MIDNIGHT AND ADDED SOME PATCHY FOG FRIDAY NIGHT INTO SATURDAY MORNING. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 50S IN THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT. EXPECT A NICE SATURDAY WITH ONLY AN ISOLATED CHANCE OF SHOWERS ACROSS THE MOUNTAINS. HIGH TEMPERATURES SATURDAY WILL MODERATE INTO THE LOWER 80S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. YOU CAN ANTICIPATE DRY WEATHER FOR SATURDAY NIGHT WITH LOW TEMPERATURES FROM THE LOWER 60S IN THE WEST TO THE MID 60S IN THE EAST. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 240 PM EDT WEDNESDAY... GOING TO UPPER RIDGE START TO LEAN WEST TO EAST ACROSS THE SOUTHERN PLAINS TO THE APPALACHIANS THIS PERIOD WITH GRADUALLY BUILDING HEIGHTS. OUR REGION WILL STAY IN A NW FLOW ALOFT THIS SUNDAY THEN MORE NORTHERLY BY TUESDAY-WEDNESDAY. MEAN SOLUTION OF MODELS SUGGEST NOT BIG THREAT OF CONVECTION THIS PERIOD...THOUGH BEST SHOT WILL BE PERHAPS MONDAY AS SHORTWAVE MOVES FROM OHIO TO THE MID ATLANTIC SETTING UP SOME HEIGHT FALLS OVER VIRGINIA...AND WEAK FRONTAL BOUNDARY PASSING ACROSS. AT THIS TIME WILL MAINTAIN IN THE CHANCE RANGE FOR POPS. WILL START TO SEE HUMIDITY ELEVATE ONCE AGAIN WITH BUILDING HEIGHTS AND LIGHT SOUTHEAST TO SOUTHWEST WINDS IN THE SFC TO LOW LVLS. HIGHS AND LOWS WILL BE CLOSE TO NORMAL FOR LATE JULY WITH MID 60S MOUNTAINS TO AROUND 70 PIEDMONT FOR LOWS...AND HIGHS IN THE LOWER TO MID 80S MOUNTAINS TO AROUND 90 PIEDMONT...INCLUDING ROANOKE CITY. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 135 AM EDT THURSDAY... EXPECTING INCREASING MID AND HIGH CLOUDS OVER THE MID ATLANTIC REGION THIS MORNING. UNTIL THE CLOUDS MOVE IN...IFR TO LIFR VISIBILITIES MAY DEVELOP DUE TO THE FORMATION OF GROUND FOG IN THE VALLEYS...INCLUDING AT KLWB. A SHORT WAVE OVER MISSOURI EARLY THIS MORNING WILL TRACK INTO THE CAROLINAS BY FRIDAY MORNING. THE ASSOCIATED SHOWERS AND THUNDERSTORMS OVER KENTUCKY AND TENNESSEE WILL MOVE EAST AND REACH SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA BY EARLY THIS AFTERNOON. MODELS IN DECENT AGREEMENT THAT NORTHERN EDGE OF THE PRECIPITATION CHANCE WILL STAY JUST SOUTH OF KBLF/KROA/KLYH. KDAN HAS THE BEST CHANCE OF SHOWERS TODAY...WHICH MAY RESULT IN BRIEF MVFR CONDITIONS. OTHERWISE CEILINGS AND VISIBILITIES WILL BE VFR. THE FRONT AND DEEP MOISTURE PUSH SOUTH OUT OF THE AREA TONIGHT. LOW CONFIDENCE IN THE WINDS THIS FORECAST PACKAGE. WITH SURFACE FRONT WAVERING CLOSE TO THE AREA...FORECAST OF WIND DIRECTION WAS CHALLENGING. EXTENDED AVIATION FORECAST... AS HIGH PRESSURE BUILDS IN THURSDAY NIGHT...LOOK FOR EAST TO NORTHEAST WINDS WHICH WILL POOL LOW LEVEL MOISTURE INTO THE EASTERN SLOPES OF THE APPALACHIANS WITH IFR/MVFR STRATUS AND FOG. FRIDAY THROUGH EARLY NEXT WEEK...HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE ACROSS THE REGION. MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT FOR THE POTENTIAL OF LATE NIGHT AND EARLY MORNING MOUNTAIN VALLEY FOG. ISOLATED SHOWERS AND STORMS CANNOT BE RULED OUT...ESPECIALLY OVER THE MOUNTAINS ON SUNDAY AFTERNOON. A WEAK BACKDOOR FRONT MAY ENTER THE REGION LATE SUNDAY NIGHT INTO MONDAY. THIS WOULD EXPAND SHOWER AND THUNDERSTORMS COVERAGE MONDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...WP AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1257 PM MST THU JUL 23 2015 .SYNOPSIS... ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS EASTERN ARIZONA TODAY AND TOMORROW...WHILE THE REST OF THE REGION SHOULD REMAIN DRY. SHOWERS SHOULD REMAIN CONFINED TO THE MOUNTAINS EAST OF PHOENIX THIS WEEKEND ALTHOUGH STORM CHANCES SHOULD INCREASE AREA-WIDE NEXT WEEK. AS FOR TEMPERATURES...EXPECT A GRADUAL RISE THROUGH THE WEEKEND WITH DESERT HIGHS APPROACHING THE 110 DEGREE MARK IN SPOTS. && .DISCUSSION... EARLY AFTERNOON SATELLITE AND RADAR IMAGERY REVEALS A PERSISTENT AREA OF SHOWERS ACROSS EASTERN ARIZONA. WHILE THE SMALL COMPLEX THAT WAS ONGOING EARLIER THIS MORNING HAS SINCE DISSIPATED...NEW CONVECTION HAS STARTED TO FORM ACROSS SOUTHEAST ARIZONA. THIS IS WITHIN AN AREA OF 1.7-1.8 INCH PWATS THAT CREPT NORTHWARD OVERNIGHT COURTESY OF A DECAYING SONORAN MCS. SOME MOISTURE ALSO MANAGED TO CREEP UP THE GULF OF CALIFORNIA ALTHOUGH SOUNDINGS OUT OF YUMA INDICATE THE LAYER WAS QUITE SHALLOW AND PWATS ARE ONLY AROUND 0.9 INCHES /NOT SURPRISING GIVEN A QUICK GLANCE AT WV IMAGERY/. ACROSS THE CENTRAL AZ DESERTS...SKIES REMAINED PARTLY TO MOSTLY SUNNY WITH TEMPS RIGHT AROUND 100 DEGREES AS OF 19Z. MODELS HAVE BEEN STRUGGLING A BIT TODAY AND DID NOT INITIALIZE THIS MORNING`S CONVECTION WELL. THUS QUITE A FEW HI-RES MODELS INDICATE A VERY ACTIVE DAY ACROSS PARTS OF THE AREA WHEREAS IN REALITY...EXTENSIVE CLOUD COVER WILL LIKELY KEEP STORMS IN CHECK AND LIMIT DAYTIME HEATING. THE PAST FEW RUNS OF THE HRRR SEEM TO HAVE CAUGHT ONTO REALITY AND INDICATE A FEW SHOWERS TRYING TO MAKE THEIR WAY INTO FAR SW MARICOPA...PARTS OF PINAL...AND SOUTHERN GILA COUNTIES BEFORE FALLING APART. THE ATMOSPHERE WEST OF TUCSON APPEARS TO BE FAVORABLE FOR STORM DEVELOPMENT /AT LEAST ACCORDING TO THE HRRR/ AND AS THOSE CONDITIONS WILL BE ADVECTED NORTHWARD THIS AFTERNOON...I WANT TO MAKE AT LEAST A SLIGHT MENTION /10 PERCENT/ OF SHOWERS AND STORMS IN THE PHOENIX AREA THIS AFTERNOON. HRRR WOULD LEAD ONE TO BELIEVE NOTHING WILL SURVIVE INTO THE LOWER DESERTS BUT WITH A WEAK REMNANT CIRCULATION ROTATING THROUGH EASTERN ARIZONA...DON`T WANT TO DISCOUNT STORM CHANCES ENTIRELY. AS FOR BLOWING DUST AS A THREAT THIS AFTERNOON...STILL A POSSIBILITY SOUTH AND EAST OF PHOENIX BUT EVEN THE HRRR ISN`T TOO ENTHUSED WITH THE IDEA OF GUSTY OUTFLOW WINDS /LIKELY DUE TO INCREASE BL MOISTURE VS. AN INVERTED-V PROFILE/. LOOKING AHEAD TO FRIDAY...SIMILAR CONDITIONS WILL RESIDE ACROSS THE AREA AND ONCE AGAIN IT MAY DEPEND ON THE PRESENCE OF ANY UPSTREAM MCVS TO KICK ANYTHING OFF ACROSS THE AREA. INHERITED POPS INDICATED 10-20 PERCENT CHANCES FROM PHOENIX EASTWARD AND THIS STILL SEEMS REASONABLE. NEARLY ALL HI-RES ENSEMBLES INDICATE TOMORROW WILL BE A DOWN DAY...BUT GLOBAL GUIDANCE STILL SUGGESTS THE POSSIBILITY OF A WEAK INVERTED TROUGH MOVING THROUGH EASTERN ARIZONA FRIDAY AFTERNOON. WOULD PREFER TO MAINTAIN SOMETHING ALONG THE LINES OF CLIMO IN PLACE VS. DROPPING BACK INHERITED VALUES. GFS/NAM/EC AND ASSOCIATED ENSEMBLES INDICATE A SUBTLE DRYING TREND THIS WEEKEND...CONSEQUENTLY TEMPERATURES WILL CLIMB SLIGHTLY AND APPROACH THE 110 DEGREE MARK IN THE NORMALLY WARMER LOCATIONS. POPS WERE ALREADY ORIENTED WELL NORTH/EAST OF PHOENIX THIS WEEKEND AND THIS STILL SEEMS MORE THAN REASONABLE WITH SSW FLOW ALOFT. ONLY MINOR CHANGES MADE TO THE FORECAST FOR THIS WEEKEND. MONDAY THROUGH WEDNESDAY... MODELS ARE ALSO SHOWING A PROGRESSIVE EASTERLY FLOW ACROSS MEXICO WITH SOME EMBEDDED WAVES THAT SPILL INTO THE PACIFIC. THIS ACTIVITY MIGHT BRING A MORE PROMISING INCREASE OF LOW LEVEL MOISTURE INTO THE DESERT SOUTHWEST...BUT IT WILL BE DEPENDENT ON THE HOW FAR WEST THE RIDGE OF HIGH PRESSURE EXPANDS. RIGHT NOW...MODELS SHOW THE BEST LOW LEVEL MOISTURE ARRIVING LATE SUNDAY/MONDAY. OVERALL...A GRADUAL UPTICK IS EXPECTED IN SHOWER AND THUNDERSTORM ACTIVITY AS WE GO INTO EARLY NEXT WEEK... ESPECIALLY OVER EASTERN ARIZONA AND THE RIM COUNTY. STILL...LOW GRADE MONSOON CONDITIONS ARE EXPECTED INTO EARLY NEXT WEEK WITH MOST OF THE THUNDERSTORMS LIKELY TO BE CONFINED TO HIGHER TERRAIN AREAS EAST AND SOUTHEAST OF CENTRAL PHOENIX. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SOLID SCT-BKN CIG SHIELD WILL REMAIN ACROSS THE FAR EASTERN PHX METRO AND EASTERN AZ HIGHER TERRAIN THROUGH THE AFTERNOON. IT WILL ALSO BECOME REINFORCED BY ADDITIONAL THUNDERSTORM BLOW OFF FROM SOUTHEAST AZ. MAINLY CLEAR SKIES TO REMAIN ACROSS MUCH OF THE PHX METRO AND WESTERN DESERTS THROUGH THE AFTN TRAFFIC PUSH. VARIABLE SURFACE WINDS WILL EVENTUALLY TAKE UP WESTERLY HEADINGS WITH ISOLATED GUSTINESS NEAR 20KTS. HI-RES MODELS INDICATE POTENTIAL FOR STORM POP-UPS NEAR THE PINAL-MARICOPA-PIMA COUNTY BORDER ALONG I-8 WHICH MAY SEND S-SW OUTFLOW AND GUSTS IN FOR KPHX AND PSBLY KIWA BY THE EARLY EVENING. WILL HOLD OFF FROM PLACING THOSE CHANGE GROUPS IN THE TAFS UNTIL PSBL STORMS BECOME ESTABLISHED IN THAT AREA ON THE RADAR. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... MOSTLY CLEAR SKIES AND PERSIST SE-S WINDS TO HOLD THROUGH THE AFTN FOR THE TERMINALS. WEST SUNDOWNER WINDS TO DEVELOP INTO KIPL UP TO 12KTS OVERNIGHT BEFORE BECOMING SOUTHEASTERLY AGAIN TOWARDS FRIDAY AM. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH THURSDAY... LOW-GRADE MONSOON PATTERN EXPECTED INTO THE WEEKEND THROUGH NEXT WEEK AS STORM CHANCES APPEAR TO BE FOCUSED IN THE MOUNTAINS NORTH/EAST OF PHOENIX. THERE MAY BE AN INTRUSION OF DEEPER MOISTURE BY THE MIDDLE OF THE WEEK WHICH WOULD RESULT IN SUBSTANTIALLY HIGHER HUMIDITIES AND ELEVATED RAINFALL CHANCES ACROSS THE ENTIRE AREA...BUT THIS IS STILL UP FOR DEBATE IN THE ENSEMBLES. FOR NOW I MAINTAINED CLIMO-LIKE POPS NEXT WEEK. AS FOR HUMIDITIES...EXPECT SINGLE DIGIT AFTERNOON READINGS ACROSS THE REGION WITH GOOD OVERNIGHT RECOVERIES. HUMIDITIES WILL GRADUALLY CREEP UPWARD THROUGH THE WEEK. WINDS SHOULD BE LIGHT AND MAINTAIN TYPICAL DIURNAL UPSLOPE/DOWNVALLEY PATTERNS. && .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION NOT EXPECTED THURSDAY BUT MAY BE POSSIBLE ON FRIDAY. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...LEINS AVIATION...NOLTE FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
310 PM EDT THU JUL 23 2015 .SYNOPSIS... ISSUED AT 436 AM EDT THU JUL 23 2015 A RIDGE OF HIGH PRESSURE WILL CONTINUE TO PROVIDE TRANQUIL WEATHER TO THE REGION THROUGH FRIDAY. CHANCES OF SHOWERS AND THUNDERSTORMS WILL INCREASE FOR SATURDAY AND SUNDAY AS AN UPPER LEVEL DISTURBANCE SKIRTING ACROSS THE NORTHERN TIER OF THE UNITED STATES DRAGS A FRONTAL BOUNDARY INTO THE REGION. HIGH TEMPERATURES THIS AFTERNOON WILL REACH INTO THE LOWER 80S WITH LOW TEMPERATURES TONIGHT DROPPING BACK INTO THE LOWER 60S. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 309 PM EDT THU JUL 23 2015 SURFACE ANALYSIS DEPICTS HIGH PRESSURE CENTERED OVER THE SOUTHERN GREAT LAKES/MIDWEST REGION. WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWING WEAK DISTURBANCE MOVING DOWN INTO GREAT LAKES REGION IN NW FLOW AND VIS SAT SHOWING EXTENSIVE DIURNAL CU FIELD OVER MUCH OF THE FORECAST AREA THIS AFTERNOON. SURFACE HIGH PRESSURE WILL CONTINUE TO DOMINATE THE REGION RESULTING IN PLEASANT SEASONABLE WEATHER IN THE SHORT TERM. HIGH PRESSURE CENTER WILL DRIFT SLOWLY EASTWARD ON FRIDAY AND UPPER LEVEL RIDGING WILL ALSO PUSH INTO THE REGION WHICH WILL TREND OUR AREA TOWARD WARMER AND MORE HUMID CONDITIONS. EXPECT TEMPS TO BE NEAR NORMAL FOR LOWS TONIGHT AND GOING SLIGHTLY ABOVE NORMAL FOR HIGHS ON FRIDAY. && .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 309 PM EDT THU JUL 23 2015 COLD FRONT...TIED TO SHORTWAVE ENERGY FLATTENING A SOUTH-CENTRAL US RIDGE INTO THE GREAT LAKES REGION...WILL WEAKEN SSE INTO THE LOCAL AREA ON SATURDAY. BETTER MID/UPPER LEVEL FORCING LIKELY PASSES NORTH AND WANES BY PEAK HEATING...THOUGH FOLD OVER OF LOW LEVEL THETA-E RIDGE AND NEAR 70F SFC DEWPOINTS SUGGEST POTENTIAL FOR MODERATE BOUNDARY LAYER DESTABILIZATION ALONG THE MAIN FRONT OR LEADING CONVECTIVE OUTFLOW BY MID AFTN-EARLY EVE. AS A RESULT THE POTENTIAL DOES EXIST FOR ISOLATED TO SCATTERED THUNDERSTORMS ALONG THIS FRONTAL ZONE...WITH AN ISOLATED STRONG STORM POSSIBLE GIVEN EXPECTATIONS FOR 25-35 KNOTS OF 0-6 KM SHEAR ON SOUTHERN FRINGE OF MID LEVEL JET WORKING THROUGH THE CENTRAL GREAT LAKES. LEFTOVER BAROCLINIC ZONE/INSTABILITY GRADIENT LOOKS TO STALL JUST SSW OF THE FORECAST AREA BY LATER SATURDAY NIGHT THROUGH MONDAY. SEVERAL LOW AMPLITUDE/CONVECTIVELY AIDED SHORTWAVES EMBEDDED IN WEAK WNW FLOW WILL HELP FOCUS SEVERAL CONVECTIVE CLUSTERS IN THE VICINITY OF THIS FEATURE. THIS PLACES AREAS MAINLY ALONG/SOUTHWEST OF THE US 30 CORRIDOR IN INDIANA FOR BETTER SHOWER/STORM CHANCES INTO EARLY NEXT WEEK. MEDIUM RANGE MODELS REMAINED IN GOOD AGREEMENT IN UPPER RIDGE BUILDING NE INTO THE REGION LATER MONDAY THROUGH EARLY WEDNESDAY IN ADVANCE OF RENEWED WESTERN CONUS TROUGHING. THIS SHOULD ALLOW HIGHER HUMIDITY/WARMER TEMPS TO BUILD IN BEFORE ANOTHER STRONGER COLD FRONT DRIVES THROUGH BY LATER WEDNESDAY OR THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 100 PM EDT THU JUL 23 2015 VFR THRU THIS TAF CYCLE AS HIGH PRESSURE CONTINUES TO DOMINATE. SAVE FOR A FEW DIURNAL CU WEST OF KSBN ALONG LAKE BREEZE AND STRAY ALTOCU IN VICINITY OF KFWA EXPECT CLEAR SKIES TO PREVAIL. WILL BEGIN KSBN WITH LIGHT NW WIND ON LAKE BREEZE...OTHERWISE LIGHT AND VARIABLE AT BOTH SITES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...MARSILI SHORT TERM...LOGSDON LONG TERM...STEINWEDEL AVIATION...LOGSDON VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
254 PM CDT THU JUL 23 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 230 PM CDT THU JUL 23 2015 QUIET AFTERNOON AND EVENING IN STORE FOR THE AREA. THE CUMULUS FIELD WILL LIKELY DISSIPATE LATER THIS EVENING AND WINDS REMAIN OUT OF THE EAST SOUTHEAST. CURRENT OBSERVATIONS SHOW A BOUNDARY ACROSS WESTERN NE WITH TOWERING CUMULUS ALREADY DEVELOPING. SOME OF THE MODELS ARE HINTING AT ISOLATED TO SCATTERED STORMS FORMING ALONG THIS BOUNDARY AS IT GRADUALLY MOVES EASTWARD. THESE STORMS MAY ONLY REACH NORTH CENTRAL KS AND SOUTH CENTRAL NE BEFORE WEAKENING. ONLY THE MOST RECENT RUNS OF THE HRRR KEEP THIS ACTIVITY GOING INTO CENTRAL KS. THERE IS A LOW LEVEL JET FORECAST TO STRENGTHEN TONIGHT OVER CENTRAL KS THAT VEERS THROUGH OUT THE MORNING HOURS. ISENTROPIC LIFT LOOKS TO DEVELOP OVER PORTIONS OF EASTERN KS ALTHOUGH THE SOUNDINGS SHOW RATHER DRY AIR WHERE THE LIFT IS MAXIMIZED. THE BETTER MOISTURE AND ISENTROPIC LIFT APPEARS TO BE FAR SOUTHEAST KS. THIS GIVES ME LOW CONFIDENCE IN ANY SHOWERS OR STORMS FORMING TONIGHT. HAVE GONE WITH SLIGHT POPS FOR NOW TO ACCOUNT FOR WESTERN NE CONVECTION REACHING THE AREA AND OR ELEVATED PRECIP FORMING DURING THE EARLY MORNING HOURS. THE ELEVATED WARM LAYER WILL STRENGTHEN AS WELL AS 850 MB TEMPS REACH 25-30 C BY TOMORROW AFTERNOON. SURFACE WINDS GRADUALLY VEER AS THE FRONT APPROACHES FROM THE NORTHWEST. DEW POINTS STAY IN THE MID TO UPPER 70S WITH THE HIGHEST VALUES IN FAR EASTERN KS. THE ONLY CONCERN IS THAT SOME OF THE MODELS SHOW DEEPER MIXING IN CENTRAL KS THAT NOSES INTO THE WESTERN FORECAST AREA. THIS COULD CAUSE THE DEW POINTS TO DECREASE DURING PEAK HEATING BUT WILL KEEP THE TEMPERATURES ABOVE 100. REGARDLESS IT APPEARS THE MOST OF THE AREA WILL SEE HEAT INDICES RANGE FROM 106-111, WHICH HAS PROMPTED A HEAT ADVISORY FOR TOMORROW. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 230 PM CDT THU JUL 23 2015 SATURDAY AND SUNDAY...ONLY MADE SMALL ADJUSTMENTS TO PREVIOUS PRECIP FORECAST. CONVECTION ROLLING OFF THE HIGH PLAINS SATURDAY NIGHT MOVES EASTWARD ALONG THE FRONTAL BOUNDARY TRAILING ACROSS THE NORTHERN PART OF THE STATE THANKS TO THE SHORTWAVE MOVING INTO THE GREAT LAKES. LLJ FOCUSES A LITTLE BETTER TO THE WEST BEFORE VEERING WITH TIME AND CONVERGING ACROSS THE NORTHERN COUNTIES. WILL HAVE TO BATTLE AGAINST PERSISTENT CAP AT 700MB. WITH THIS PATTERN WOULD ANTICIPATE STORMS TO MOVE ALONG THE PERIPHERY AND WILL DRAW UP RAIN CHANCES AS SUCH. NAM AND GFS BRING A SECONDARY SHORTWAVE OUT OF THE WEST LATER IN THE DAY SATURDAY...WITH A LITTLE STRONGER LLJ INTO THE OVERNIGHT HOURS. WOULD LIKELY SEE A BREAK IN PRECIP IN THE MID TO LATE DAY BEFORE STORMS COME IN FROM THE WEST INTO THE OVERNIGHT HOURS...ONCE AGAIN FOCUSING BETTER TO THE NORTH. AS THIS WAVE PASSES TO THE EAST...THE RIDGE ALOFT AMPLIFIES IN ITS WAKE...AND WILL MOST LIKELY BRING AN END TO RAIN CHANCES LATER IN THE DAY ON SUNDAY. HAVE DROPPED TO JUST A SLIGHT CHANCE ON SUNDAY. CHANCES FOR RAIN AND ASSOCIATED CLOUD COVER AND COOLER OUTFLOWS WILL HAVE PERIODIC IMPACTS ON THE HEAT...HOWEVER FOR SATURDAY BETWEEN SYSTEMS THINK ITS A GOOD BET THAT HEAT INDICIES WILL RISE BACK TO ADVISORY LEVELS OVER THE SOUTHERN PARTS OF THE CWA...BUT THE NORTHERN COUNTIES COULD CATCH MORE OF A BREAK. NOT EXTENDING THE ADVISORY PRODUCT AT THIS TIME, BUT WILL LIKELY NEED TO BE FOR AT LEAST PART OF THE AREA FOR THE DAY ON SATURDAY. THINK SUNDAY WILL HAVE MORE IMPACT FROM CONVECTION NEAR THE AREA...AND DON`T CURRENTLY HAVE ADVISORY INDICES IN THE FORECAST. MONDAY-THURSDAY...UPPER LONGWAVE TROF MOVING INTO THE NORTHERN ROCKIES LATE MONDAY HELPS STRENGTHEN THE RIDGE ACROSS THE PLAINS BRINGING ANOTHER FEW HOT DAYS FOR MONDAY AND TUESDAY. NEXT FRONT ASSOCIATED WITH THAT UPPER TROF MOVES INTO THE CENTRAL PLAINS ON WEDNESDAY...BRINGING A SLIGHTLY BETTER CHANCE FOR RAIN FOLLOWED BY POTENTIALLY A NICE COOL DOWN BY LATE WEDNESDAY INTO THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1232 PM CDT THU JUL 23 2015 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. THERE IS A SLIGHT CHANCE FOR AN ISOLATED SHOWER AROUND SUNRISE TOMORROW. && .TOP WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM NOON TO 8 PM CDT FRIDAY FOR KSZ008>012- 020>024-026-034>040-054>056-058-059. && $$ SHORT TERM...SANDERS LONG TERM...67 AVIATION...SANDERS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
229 PM CDT THU JUL 23 2015 ...UPDATED LONG TERM DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 1259 PM CDT THU JUL 23 2015 AN UPPER LEVEL DISTURBANCE WILL CROSS NORTHERN KANSAS EARLY THIS EVENING AS A SURFACE WARM FRONT LIFTS NORTH ACROSS WESTERN KANSAS. NORTH OF THIS BOUNDARY SURFACE DEWPOINTS THIS MORNING WERE IN THE UPPER 60S TO LOWER 70S. BASED ON THE EXPECTED LOCATION OF THIS BOUNDARY EARLY THIS EVENING ALONG WITH WHERE THE BETTER MOISTURE AND INSTABILITY WILL BE AROUND 00Z FRIDAY AHEAD OF THE UPPER LEVEL DISTURBANCE WILL CONTINUE TO FAVOR KEEPING SOME ISOLATED TO WIDELY SCATTERED THUNDERSTORMS LATE TODAY AND EARLY THIS EVENING NORTH OF ROUGHLY HIGHWAY 96. SIMILAR TO LAST NIGHT THE BETTER CHANCES FOR CONVECTION WILL BE AFTER SUNSET AS WARM AIR ADVECTION IMPROVES AND BETTER 700MB TO 500MB LAPSE RATES DEVELOP AS THE UPPER LEVEL DISTURBANCE CROSSES WESTERN KANSAS. HEAVY RAINFALL AND GUSTY WINDS WILL BE THE MAIN HAZARD FROM ANY STORM THAT DOES CROSS NORTHERN KANSAS EARLY TONIGHT. 850MB TEMPERATURES WARM ROUGHLY 2-3C BETWEEN 00Z FRIDAY AND 00Z SATURDAY. BASED ON THIS WARMING TREND AND THE EXPECTED HIGHS LATER TODAY THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH TEMPERATURES CLIMBING TO AROUND 100 DEGREES FRIDAY AFTERNOON. THIS COMBINED WITH AFTERNOON DEWPOINTS IN THE LOW TO MID 60S WILL YIELD HEAT INDEX VALUES OF 100 TO AROUND 105. THE HIGHER VALUES FRIDAY AFTERNOON WILL ROUGHLY BE ALONG AND EAST OF HIGHWAY 183. BASED ON WHERE THESE HIGHER HEAT INDEX READINGS ARE EXPECTED WILL BE ISSUING A HEAT ADVISORY FOR PORTIONS OF NORTH CENTRAL AND SOUTH CENTRAL KANSAS FRIDAY AFTERNOON. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 227 PM CDT THU JUL 23 2015 A COLD FRONT/SURFACE BOUNDARY WILL DROP SOUTH ACROSS WESTERN KANSAS LATE FRIDAY NIGHT AS ANOTHER UPPER LEVEL TROUGH CROSSES THE CENTRAL HIGH PLAINS. GIVEN THE LOCATION OF THIS FRONTAL BOUNDARY FRIDAY NIGHT AND THE MID LEVEL INSTABILITY AHEAD OF THIS NEXT UPPER LEVEL SYSTEM WILL KEEP THE BETTER CHANCES FOR OVERNIGHT CONVECTION ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS. OVER THE WEEKEND PERIOD THE BETTER CHANCE FOR THUNDERSTORMS STILL APPEAR TO BE LATE SATURDAY THROUGH EARLY SUNDAY AS ANOTHER, STRONGER UPPER LEVEL TROUGH CROSSES THE CENTRAL PLAINS. AT THIS TIME CONFIDENCE IS NOT HIGH ON TIMING OF THIS LATE SATURDAY UPPER LEVEL FEATURE SO AM LEANING TOWARDS STAYING CLOSE TO THE PREVIOUS FORECAST ON TIMING OF PRECIPITATION. DESPITE A COLD FRONT MOVING INTO SOUTHWEST KANSAS OVER THE WEEKEND TEMPERATURES WILL STAY ON THE WARM SIDE. HIGHS BOTH SATURDAY AND SUNDAY WILL BE IN THE MID TO UPPER 90S. EARLY NEXT WEEK THE UPPER HIGH LOCATED OVER THE SOUTHERN PLAINS WILL BEGIN TO MOVE EAST/NORTHEAST, AND AN UPPER TROUGH WILL MOVE ACROSS THE WESTERN UNITED STATES. SOME TROPICAL MOISTURE WILL BE RETURNING TO THE CENTRAL HIGH PLAINS EARLY NEXT WEEK AS A SOUTHWESTERLY FLOW IMPROVES. GIVEN THIS ALONG WITH ANY SUBTLE WAVE EMBEDDED IN THE SOUTHWEST FLOW THERE WILL BE A CHANCE/SLIGHT CHANCE FOR LATE DAY OR OVERNIGHT THUNDERSTORMS EARLY NEXT WEEK. THE BETTER OPPORTUNITY WILL BE TOWARDS MID WEEK BASED ON TIMING OF THE NEXT COLD FRONT RETURNING TO WESTERN KANSAS AND THE TRACK OF THE UPPER LEVEL TROUGH AS IT CROSSES THE ROCKIES AND MOVES OUT INTO THE NORTHERN AND CENTRAL PLAINS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1210 PM CDT THU JUL 23 2015 A WARM FRONT WILL LIFT NORTH ACROSS SOUTHWEST KANSAS TODAY AND NORTH CENTRAL KANSAS LATE TONIGHT. AS THIS SURFACE BOUNDARY PASSES A SOUTHEAST WIND AT 10 TO NEAR 15 KNOTS WILL SHIFT TO THE SOUTH SOUTHWEST. BUFR SOUNDINGS AND HRRR BOTH INDICATED VFR CONDITIONS THIS AFTERNOON AND TONIGHT. AREAS OF IFR CONDITIONS FROM STRATUS AND MVFR VISIBILITIES FROM EARLY MORNING FOG WILL BE POSSIBLE NORTH OF THE WARM FRONT. AT THIS TIME GIVEN WHERE THIS SURFACE BOUNDARY IS FORECAST TO BE LOCATED AROUND 12Z FRIDAY BY SEVERAL MODELS WILL TREND TOWARDS LOWER CEILINGS AND VISIBILITIES IN THE HYS AREA FOR SEVERAL HOURS AROUND DAYBREAK. && .PRELIMINARY POINT TEMPS/POPS... DDC 73 101 73 100 / 10 10 20 40 GCK 72 101 71 98 / 10 10 20 40 EHA 70 99 70 99 / 10 20 20 30 LBL 72 100 72 100 / 10 10 10 30 HYS 74 102 74 96 / 20 20 30 40 P28 76 102 76 101 / 10 10 10 30 && .DDC WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM NOON TO 8 PM CDT FRIDAY FOR KSZ031-046-065- 066-081-090. && $$ SHORT TERM...BURGERT LONG TERM...BURGERT AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
101 PM CDT THU JUL 23 2015 ...UPDATED SHORT TERM DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 1259 PM CDT THU JUL 23 2015 AN UPPER LEVEL DISTURBANCE WILL CROSS NORTHERN KANSAS EARLY THIS EVENING AS A SURFACE WARM FRONT LIFTS NORTH ACROSS WESTERN KANSAS. NORTH OF THIS BOUNDARY SURFACE DEWPOINTS THIS MORNING WERE IN THE UPPER 60S TO LOWER 70S. BASED ON THE EXPECTED LOCATION OF THIS BOUNDARY EARLY THIS EVENING ALONG WITH WHERE THE BETTER MOISTURE AND INSTABILITY WILL BE AROUND 00Z FRIDAY AHEAD OF THE UPPER LEVEL DISTURBANCE WILL CONTINUE TO FAVOR KEEPING SOME ISOLATED TO WIDELY SCATTERED THUNDERSTORMS LATE TODAY AND EARLY THIS EVENING NORTH OF ROUGHLY HIGHWAY 96. SIMILAR TO LAST NIGHT THE BETTER CHANCES FOR CONVECTION WILL BE AFTER SUNSET AS WARM AIR ADVECTION IMPROVES AND BETTER 700MB TO 500MB LAPSE RATES DEVELOP AS THE UPPER LEVEL DISTURBANCE CROSSES WESTERN KANSAS. HEAVY RAINFALL AND GUSTY WINDS WILL BE THE MAIN HAZARD FROM ANY STORM THAT DOES CROSS NORTHERN KANSAS EARLY TONIGHT. 850MB TEMPERATURES WARM ROUGHLY 2-3C BETWEEN 00Z FRIDAY AND 00Z SATURDAY. BASED ON THIS WARMING TREND AND THE EXPECTED HIGHS LATER TODAY THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH TEMPERATURES CLIMBING TO AROUND 100 DEGREES FRIDAY AFTERNOON. THIS COMBINED WITH AFTERNOON DEWPOINTS IN THE LOW TO MID 60S WILL YIELD HEAT INDEX VALUES OF 100 TO AROUND 105. THE HIGHER VALUES FRIDAY AFTERNOON WILL ROUGHLY BE ALONG AND EAST OF HIGHWAY 183. BASED ON WHERE THESE HIGHER HEAT INDEX READINGS ARE EXPECTED WILL BE ISSUING A HEAT ADVISORY FOR PORTIONS OF NORTH CENTRAL AND SOUTH CENTRAL KANSAS FRIDAY AFTERNOON. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 248 AM CDT THU JUL 23 2015 THE UPPER LEVEL HIGH WILL CONTINUE TO SIT OVER THE SOUTHERN PLAINS FRIDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH UPPER LEVEL SHORTWAVES MOVING UP AND OVER THIS FEATURE. THIS WILL BRING PERIODIC BURSTS OF ENHANCED LIFT ACROSS WESTERN KANSAS. THE FIRST SHORTWAVE PASSES OVER NEBRASKA FRIDAY NIGHT WITH CHANCES OF THUNDERSTORMS ACROSS NORTHERN AND NORTH CENTRAL KANSAS. THE SECOND PASSES FARTHER SOUTH ACROSS KANSAS AND NEBRASKA SATURDAY AFTERNOON INTO SATURDAY NIGHT. THIS WILL BRING A BETTER CHANCE OF THUNDERSTORMS ACROSS ALL OF WESTERN KANSAS. SKIES LOOK TO BE PARTLY CLOUDY EACH DAY WITH THE EXCEPTION OF WHEN STORMS ARE PRESENT. WINDS WILL GENERALLY BE FROM A SOUTHERLY DIRECTION FRIDAY THROUGH SATURDAY NIGHT AS A TROUGH OF LOW PRESSURE CONTINUES AROUND THE KS/CO BORDER. THUNDERSTORM CHANCES CONTINUE SUNDAY THOUGH THE FIRST PART OF NEXT WEEK AS ADDITIONAL SHORTWAVES MOVE THROUGH OR NORTH OF THE FORECAST AREA. SOUTHERLY WINDS CONTINUE THROUGH MONDAY THEN COULD SHIFT TO MORE OF A NORTHERLY DIRECTION MONDAY NIGHT INTO TUESDAY AS A COLD FRONT PASSES THROUGH THE AREA. SKIES THROUGH THIS PERIOD ARE EXPECTED TO BE PARTLY CLOUDY WITH THE EXCEPTION OF ABOVE AND AROUND THUNDERSTORM ACTIVITY. AS FOR TEMPERATURES, HIGHS WILL REMAIN ABOVE NORMAL WITH HIGHS IN THE 100-105 RANGE FRIDAY WITH UPPER 90S EXPECTED SATURDAY THROUGH MONDAY. TEMPERATURES COOL SLIGHTLY TUESDAY INTO WEDNESDAY BEHIND THE AFOREMENTIONED COLD FRONT. HIGH DEWPOINTS WILL ALSO REMAIN ACROSS THE AREA FRIDAY AND A HEAD ADVISORY MAY BE NEED TO BE ISSUED ACROSS CENTRAL AND SOUTH CENTRAL KANSAS FRIDAY AFTERNOON AS HEAT INDICES LOOK TO REACH ABOVE 105 DEGREES. LOWS WILL ALSO REMAIN ABOVE NORMAL WITH OVERNIGHT TEMPERATURES RANGING FROM THE UPPER 60S ACROSS WEST CENTRAL KANSAS TO MID 70S ACROSS SOUTH CENTRAL KANSAS FRIDAY NIGHT THROUGH MONDAY NIGHT. LOWS THEN DECREASE A FEW DEGREES AS WE HEAD INTO THE MID PART OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1210 PM CDT THU JUL 23 2015 A WARM FRONT WILL LIFT NORTH ACROSS SOUTHWEST KANSAS TODAY AND NORTH CENTRAL KANSAS LATE TONIGHT. AS THIS SURFACE BOUNDARY PASSES A SOUTHEAST WIND AT 10 TO NEAR 15 KNOTS WILL SHIFT TO THE SOUTH SOUTHWEST. BUFR SOUNDINGS AND HRRR BOTH INDICATED VFR CONDITIONS THIS AFTERNOON AND TONIGHT. AREAS OF IFR CONDITIONS FROM STRATUS AND MVFR VISIBILITIES FROM EARLY MORNING FOG WILL BE POSSIBLE NORTH OF THE WARM FRONT. AT THIS TIME GIVEN WHERE THIS SURFACE BOUNDARY IS FORECAST TO BE LOCATED AROUND 12Z FRIDAY BY SEVERAL MODELS WILL TREND TOWARDS LOWER CEILINGS AND VISIBILITIES IN THE HYS AREA FOR SEVERAL HOURS AROUND DAYBREAK. && .PRELIMINARY POINT TEMPS/POPS... DDC 98 73 101 73 / 20 10 10 20 GCK 99 72 101 71 / 10 10 10 20 EHA 98 70 99 70 / 10 10 20 20 LBL 100 72 100 72 / 10 10 10 10 HYS 96 74 102 74 / 20 20 20 30 P28 98 76 102 76 / 50 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM 1 PM TO 8 PM CDT FRIDAY FOR KSZ031-046-065- 066-081-090. && $$ SHORT TERM...BURGERT LONG TERM...HOVORKA_42 AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1212 PM CDT THU JUL 23 2015 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1210 PM CDT THU JUL 23 2015 AT 12Z THURSDAY AN UPPER LEVEL TROUGH EXTENDED FROM THE PACIFIC NORTHWEST TO JUST OFF THE CENTRAL CALIFORNIA COAST. AN UPPER LEVEL 250MB JET EXTENDED FROM THE BASE OF THIS UPPER TROUGH TO NORTHERN UTAH. FURTHER EAST AN UPPER LEVEL RIDGE AXIS WAS LOCATED OVER THE CENTRAL AND NORTHERN PLAINS. ACROSS THE SOUTHWEST UNITED STATES SEVERAL UPPER LEVEL DISTURBANCES WERE EVIDENT EMBEDDED IN THE SOUTH TO SOUTHWESTERLY FLOW. ONE OF THESE UPPER WAVES AT 12Z THURSDAY WERE LOCATED OVER EASTERN COLORADO. A 700MB BAROCLINIC ZONE WAS LOCATED ACROSS KANSAS AND NEBRASKA THIS MORNING. TEMPERATURES VARIED FROM +9C AT OMAHA TO +12C AT DODGE CITY AND +13C WAS REPORTED AT NORTH PLATTE. A SURFACE WARM FRONT EXTENDED FROM SOUTHEAST COLORADO TO WESTERN OKLAHOMA. JUST NORTH OF THIS FRONT EARLIER THIS MORNING A SOUTHEASTERLY FLOW WAS OBSERVED ACROSS SOUTHWESTERN KANSAS WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 248 AM CDT THU JUL 23 2015 ABOVE NORMAL TEMPERATURES AND DEWPOINTS WILL CONTINUE TODAY THROUGH TONIGHT AS MID LEVEL TEMPERATURES REMAIN WARM. A LARGE UPPER LEVEL HIGH SITS ABOVE THE SOUTHERN PLAINS WITH SHORTWAVES MOVING AROUND ITS PERIPHERY. MOSTLY CLEAR SKIES ARE ANTICIPATED THIS MORNING WITH A FEW CUMULUS CLOUDS FORMING IN THE AFTERNOON. WINDS WILL GENERALLY BE FROM A SOUTHERLY DIRECTION TODAY AS A TROUGH OF LOW PRESSURE CONTINUES ACROSS EASTERN COLORADO. HIGHS IN THE UPPER 90S TO AROUND 100 DEGREES ARE ANTICIPATED BY MID AFTERNOON WITH DEWPOINTS RANGING FROM THE UPPER 60S ACROSS WESTERN PORTIONS OF THE CWA TO LOWER 70S ACROSS THE EASTERN PORTIONS OF THE CWA. THE WARM TEMPERATURES IN COMBINATION OF THE HIGH DEWPOINTS WILL CAUSE HEAT INDICES TO SHOOT AROUND OR ABOVE 100 DEGREES, ESPECIALLY ACROSS SOUTH CENTRAL KANSAS. HEAT INDICES APPROACH HEAT ADVISORY CRITERIA ACROSS SOUTH CENTRAL KANSAS THIS AFTERNOON BUT WILL REFRAIN FROM ISSUING AS THE HIGHEST APPARENT TEMPERATURE VALUE DISPLAYED IS 104 DEGREES. AS FOR TONIGHT, A FEW THUNDERSTORMS MAY BE POSSIBLE ACROSS NORTH AND NORTH CENTRAL KANSAS, HOWEVER, I BELIEVE THAT THIS ACTIVITY SHOULD STAY OUT OF THE FORECAST AREA. LOWS OVERNIGHT LOOK TO RANGE FROM THE UPPER 60S ACROSS WEST CENTRAL KANSAS TO MID 70S ACROSS SOUTH CENTRAL KANSAS. SOUTHERLY WINDS CONTINUE OVERNIGHT AS THE PERSISTENT TROUGH OF LOW PRESSURE SITS AROUND THE KS/CO BORDER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 248 AM CDT THU JUL 23 2015 THE UPPER LEVEL HIGH WILL CONTINUE TO SIT OVER THE SOUTHERN PLAINS FRIDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH UPPER LEVEL SHORTWAVES MOVING UP AND OVER THIS FEATURE. THIS WILL BRING PERIODIC BURSTS OF ENHANCED LIFT ACROSS WESTERN KANSAS. THE FIRST SHORTWAVE PASSES OVER NEBRASKA FRIDAY NIGHT WITH CHANCES OF THUNDERSTORMS ACROSS NORTHERN AND NORTH CENTRAL KANSAS. THE SECOND PASSES FARTHER SOUTH ACROSS KANSAS AND NEBRASKA SATURDAY AFTERNOON INTO SATURDAY NIGHT. THIS WILL BRING A BETTER CHANCE OF THUNDERSTORMS ACROSS ALL OF WESTERN KANSAS. SKIES LOOK TO BE PARTLY CLOUDY EACH DAY WITH THE EXCEPTION OF WHEN STORMS ARE PRESENT. WINDS WILL GENERALLY BE FROM A SOUTHERLY DIRECTION FRIDAY THROUGH SATURDAY NIGHT AS A TROUGH OF LOW PRESSURE CONTINUES AROUND THE KS/CO BORDER. THUNDERSTORM CHANCES CONTINUE SUNDAY THOUGH THE FIRST PART OF NEXT WEEK AS ADDITIONAL SHORTWAVES MOVE THROUGH OR NORTH OF THE FORECAST AREA. SOUTHERLY WINDS CONTINUE THROUGH MONDAY THEN COULD SHIFT TO MORE OF A NORTHERLY DIRECTION MONDAY NIGHT INTO TUESDAY AS A COLD FRONT PASSES THROUGH THE AREA. SKIES THROUGH THIS PERIOD ARE EXPECTED TO BE PARTLY CLOUDY WITH THE EXCEPTION OF ABOVE AND AROUND THUNDERSTORM ACTIVITY. AS FOR TEMPERATURES, HIGHS WILL REMAIN ABOVE NORMAL WITH HIGHS IN THE 100-105 RANGE FRIDAY WITH UPPER 90S EXPECTED SATURDAY THROUGH MONDAY. TEMPERATURES COOL SLIGHTLY TUESDAY INTO WEDNESDAY BEHIND THE AFOREMENTIONED COLD FRONT. HIGH DEWPOINTS WILL ALSO REMAIN ACROSS THE AREA FRIDAY AND A HEAD ADVISORY MAY BE NEED TO BE ISSUED ACROSS CENTRAL AND SOUTH CENTRAL KANSAS FRIDAY AFTERNOON AS HEAT INDICES LOOK TO REACH ABOVE 105 DEGREES. LOWS WILL ALSO REMAIN ABOVE NORMAL WITH OVERNIGHT TEMPERATURES RANGING FROM THE UPPER 60S ACROSS WEST CENTRAL KANSAS TO MID 70S ACROSS SOUTH CENTRAL KANSAS FRIDAY NIGHT THROUGH MONDAY NIGHT. LOWS THEN DECREASE A FEW DEGREES AS WE HEAD INTO THE MID PART OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1210 PM CDT THU JUL 23 2015 A WARM FRONT WILL LIFT NORTH ACROSS SOUTHWEST KANSAS TODAY AND NORTH CENTRAL KANSAS LATE TONIGHT. AS THIS SURFACE BOUNDARY PASSES A SOUTHEAST WIND AT 10 TO NEAR 15 KNOTS WILL SHIFT TO THE SOUTH SOUTHWEST. BUFR SOUNDINGS AND HRRR BOTH INDICATED VFR CONDITIONS THIS AFTERNOON AND TONIGHT. AREAS OF IFR CONDITIONS FROM STRATUS AND MVFR VISIBILITIES FROM EARLY MORNING FOG WILL BE POSSIBLE NORTH OF THE WARM FRONT. AT THIS TIME GIVEN WHERE THIS SURFACE BOUNDARY IS FORECAST TO BE LOCATED AROUND 12Z FRIDAY BY SEVERAL MODELS WILL TREND TOWARDS LOWER CEILINGS AND VISIBILITIES IN THE HYS AREA FOR SEVERAL HOURS AROUND DAYBREAK. && .PRELIMINARY POINT TEMPS/POPS... DDC 98 73 101 73 / 20 10 20 20 GCK 99 72 101 71 / 10 10 30 30 EHA 98 70 99 70 / 10 10 20 20 LBL 100 72 100 72 / 10 10 20 20 HYS 96 74 102 74 / 20 20 30 30 P28 98 76 102 76 / 50 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...HOVORKA_42 LONG TERM...HOVORKA_42 AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
400 PM CDT THU JUL 23 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 354 PM CDT THU JUL 23 2015 THERE STILL MAY BE AN ISOLATED SHOWER OR THUNDERSTORM EARLY THIS EVENING OVER THE FAR SOUTHERN PART OF THE CWA EARLY THIS EVENING WHERE THERE ARE CURRENTLY A FEW STORMS DEVELOPING IN CLOSE TO THE STATIONARY FRONT WITH MLCAPES NEAR 1000 J/KG. ONCE WE GET PAST DAYTIME HEATING, THINK IT WILL BE A DRY NIGHT AS A SHORTWAVE RIDGE AXIS MOVES IN FROM KANSAS SUPPLYING SOME SUBSIDENCE. LATEST RUNS OF THE WRF AND RAP AREA NOT SHOWING MUCH IN THE WAY OF LOW LEVEL FORCING OR INSTABILITY THAT WOULD SUPPORT ADDITIONAL THUNDERSTORM DEVELOPMENT FROM MID EVENING ONWARD. MOS TEMPERATURES LOOK GOOD FOR THE LOW TEMPERATURES. BRITT .LONG TERM: (FRIDAY THROUGH NEXT THURSDAY) ISSUED AT 354 PM CDT THU JUL 23 2015 PINNING DOWN THUNDERSTORM THREAT...AND INCREASING HEAT AND HUMIDITY... ARE THE PRIMARY FORECAST CONCERNS HEADING INTO THE WEEKEND AND THE START OF NEXT WEEK. UPPER LEVEL RIDGE IS FORECAST TO INTENSIFY A BIT ACROSS THE REGION DURING THE DAY ON FRIDAY, WITH REMANTS OF WEAK LOW LEVEL BOUNDARY EXPECTED TO REMAIN LOCKED BENEATH THE INCREASING HIGH PRESSURE ALOFT. SCENARIO ISN`T ONE THAT FAVORS A LOT IN THE WAY OF CONVECTION, BUT WILL MAINTAIN SOME LOW POPS OVER THE OZARKS DURING THE AFTERNOON HOURS WHERE LOW LEVEL CONVERGENCE/OROGRAPHIC LIFT COULD BE JUST ENOUGH TO KICK OFF A FEW ISOLATED CELLS. CONCERN FOR CONVECTION INCREASES HEADING INTO THE WEEKEND; FIRST AS SEVERAL WEAK DISTURBANCES BEGIN TO MIGRATE OVER THE TOP OF THE RIDGE AND INTO THE GREAT LAKES. THIS SUGGESTS A RING OF FIRE PATTERN FROM THE NORTHERN PLAINS INTO THE MID AND UPPER MISSISSIPPI VALLEY, AND PRIMARY QUESTION IS HOW FAR SOUTH THIS CONVECTION WILL GET INTO OUR FORECAST AREA. FIRST RIPPLE IN THE FLOW AND ASSOCIATED WAA IS PROGGED TO COMMENCE LATE FRIDAY NIGHT, AND ALL MODELS BEGIN TO HINT AT SOME PRECIP IN OUR AREA BY 12Z SATURDAY, ALTHOUGH NAM AND ECMWF ARE MUCH FURTHER SOUTH THAN THE GFS QPF. NAM AND ECMWF CONTINUE CONVECTION ACROSS MUCH OF THE AREA DURING THE DAY ON SATURDAY WITH SEVERAL MORE ROUNDS SATURDAY NIGHT AND SUNDAY, WHILE GFS IS SLOWER WITH PRECIP PUSHING INTO OUR AREA, AND FOCUSES IT SOUTHWARD SURGE OF QPF IN THE SATURDAY NIGHT/SUNDAY TIME FRAME. OBVIOUSLY...THERE IS CONSIDERABLE UNCERTAINTY IN SPECIFIC POP TRENDS OVER THE WEEKEND, WITH A MYRIAD OF ILL-DEFINED FEATURES (EXTREMELY WEAK UPPER LEVEL DYNAMICS, SEVERAL BOUTS OF WEAK NOCTURNAL JET FORCING, AN INCREASINGLY MOIST AND UNSTABLE AIRMASS, OUTFLOW BOUNDARIES, AND WHAT APPEARS TO BE WEAK SYNOPTIC FRONT TO OUR NORTH THAT WILL BE BEAT SOUTH BY SEVERAL CONVECTIVE COMPLEXES) THAT COULD PRODUCE QUITE A BIT OF ACTIVE WEATHER ACROSS THE FA. AS NOTED BY WFO EAX EARLIER TODAY...THIS UPCOMING PATTERN IS VERY SIMILAR TO THAT THE CENTRAL CONUS EXPERIENCED ABOUT A WEEK AGO. GIVEN THIS UNCERTAINTY...HAVE PRETTY MUCH MAINTAINED GOING FORECAST TRENDS WHICH INDICATE THUNDERSTORM CHANCES RAMPING UP INTO THE CHANCE CATEGORY OVER MUCH OF THE AREA LATE FRIDAY NIGHT AND SATURDAY. IN TRUTH, THERE WILL PROBABLY BE PERIODS OF MUCH HIGHER AND MUCH LOWER POPS, BUT THOSE ADJUSTMENTS WILL HAVE TO BE MADE WHEN SHORT-TERM TRENDS BECOME A BIT MORE CLEAR. OTHER CONCERN IS INCREASING LEVELS OF HEAT AND HUMIDITY AS GRADUAL INCREASE IN SOUTHERLY LOW LEVEL FLOW ALLOWS DEWPOINTS TO REBOUND INTO THE MIDDLE AND UPPER 70S. ALTHOUGH THIS INCREASE WILL BE FELT WEST OF THE MISSISSIPPI RIVER TOMORROW, PRIMARY CONCERN WILL BE IN THE SATURDAY-SUNDAY TIME FRAME WHEN AFTERNOON DEWPOINTS ARE EXPECTED TO BE IN THE MID TO UPPER 70S AND TEMPERATURES SHOULD BE WELL IN THE 90S. TEMPERATURES WILL BE THE KEY TO HOW OPPRESSIVE IT WILL BECOME, AND THIS WILL BE TIED TO AMOUNT OF CONVECTION AND CLOUDINESS THE AREA EXPERIENCES. IF CLOUDS AND CONVECTION ARE AT A MINIMUM, HEAT INDICIES OF 105 WILL BE LIKELY OVER PARTS OF MID MISSOURI. AGAIN, CONSIDERABLE UNCERTAINTY AT THIS POINT WITH THE ABOVE PARAMETERS, SO WILL LET MID SHIFT TAKE ANOTHER LOOK BEFORE HOISTING ANY HEADLINES. SEASONABLY WARM TEMPS...ALONG WITH LOW THUNDERSTORM CHANCES... REMAIN IN THE FORECAST THROUGH WEDNESDAY AS SOME REMNANTS OF LOW LEVEL BOUNDARY AND UNSTABLE AIRMASS REMAINS LOCKED OVER THE REGION. POPS SHOULD BE A BIT HIGHER BY MIDWEEK AS SHORTWAVE BREAKS DOWN THE UPPER LEVEL RIDGE AND ALLOWS A FRONTAL BOUNDARY TO PUSH INTO THE AREA. TRUETT && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1226 PM CDT THU JUL 23 2015 EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH THE PERIOD. ONLY EXCEPTION IS THERE MAY BE SOME PATCHY MVFR FOG IN LOW LYING AREAS INCLUDING KSUS AND KCPS LATE TONIGHT, HOWEVER UNCERTAINTY IS TOO HIGH AT THIS POINT TO INCLUDE IN THE TAFS. WINDS WILL REMAINS LIGHT EAST TO SOUTHEASTERLY. SPECIFICS FOR KSTL: EXPECT DRY AND VFR CONDITIONS THROUGH THE PERIOD. BRITT && .PRELIMINARY POINT TEMPS/POPS: SAINT LOUIS 72 90 74 93 / 5 5 10 40 QUINCY 66 87 72 89 / 5 5 40 40 COLUMBIA 70 90 74 93 / 10 20 10 30 JEFFERSON CITY 71 91 76 93 / 10 20 10 30 SALEM 65 87 69 89 / 5 5 10 20 FARMINGTON 67 87 69 88 / 10 10 10 20 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ELKO NV
312 PM PDT THU JUL 23 2015 .SYNOPSIS...TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY BELOW NORMAL FOR THE THIRD WEEK OF JULY. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND INTO THE EVENING. DRIER WEATHER EXPECTED THIS WEEKEND. && .SHORT TERM...TODAY THROUGH SATURDAY. KLRX CONTINUES TO BE CONVECTIVE OVER THE EASTERN PORTION OF THE CWA. THE HRRR HAS BEEN A TAD BIT TOO EAGER WITH THE DEVELOPMENT OF TSRA OVER THE CWA...BUT SEEMS TO HAVE FEWER CONVECTIVE FEEDBACK ISSUES THAN BOTH THE GFS AND THE NAM...MAKING IT THE MODEL OF CHOICE FOR TODAY. AS TIME ELAPSES...NCEP GUIDANCE DRIES MUCH OF THE CWA...WITH ONE CAVEAT...NORTHERN ELKO COUNTY. MORE BELOW NORMAL TEMPS ANTICIPATED THIS FORECAST PERIOD. FOR ELKO...THE MEAN MAX TEMP FOR JULY 24TH AND 25TH IS 92F...WENT FOR A HIGH OF 85F ON THE 24TH AND 88F ON THE 25TH. FOR WINNEMUCCA...THE MEAN MAX TEMP IS 95F FOR BOTH THE 24TH AND 25TH OF JULY...PROGGED A HIGH OF 86F AND 88F RESPECTIVELY. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY. TEMPS WILL BE BELOW AVERAGE DURING THE FIRST PART OF THE WEEK...BEFORE RETURNING TO ABOVE/NEAR AVERAGE. SUNDAY AND MONDAY WILL FEATURE A TROUGH CLIPPING NORTHERN NEVADA. THE MODELS HAVE TRENDED DEEPER WITH THIS SYSTEM...WHICH COULD BRING AN UNSEASONABLY STRONG COLD FRONT TO NORTHERN NEVADA. THIS WOULD DROP DAYTIME HIGHS TO WELL BELOW AVERAGE FOR MONDAY AND TUESDAY. MANY LOCATIONS WILL SEE HIGHS IN THE 70S/80S. SOME OF THE HIGHER VALLEYS ACROSS THE NORTH...COULD DIP INTO THE 60S. OVERNIGHT LOWS WILL BE QUITE COOL AS WELL. PLACES LIKE CHARLESTON AND WILD HORSE COULD SEE LOWER 30S FOR LOWS ON MON/TUE. BY THE MIDDLE TO END OF NEXT WEEK...HEIGHTS WILL BEGIN TO RISE. THIS WILL RESULT IN WARMING TEMPS AND DRIER CONDITIONS. MODELS STILL HINT AT SOME MONSOON MOISTURE SNEAKING INTO SOUTHERN NEVADA...BUT CONFIDENCE REMAINS FAIR AT BEST. && .AVIATION...ALREADY HAD -TSRA AT KEKO TODAY. EXPECT ADDITIONAL -SHRA/VCTS THROUGH THE REST OF THE AFTERNOON AND INTO THE EARLY EVENING. KELY/KWMC/KTPH WILL STAY DRY. && .FIRE WEATHER...MOST OF THE LIGHTNING TODAY HAS OCCURRED IN THE NORTHERN HALF OF 469...ALTHOUGH ISOLATED CELLS HAVE POPPED UP AS FAR WEST AS 454. EXPECTING THE DYNAMICS TO GRADUALLY SHIFT NORTH AND EAST. EXPECT THE SHOWERS AND THUNDERSTORMS TO TAPER OFF FRIDAY. SATURDAY AND SUNDAY EXPECTING DRY CONDITIONS. NEXT WEEK...EXPECTING UPPER LEVEL HEIGHTS TO RISE AS RIDING MOVES INTO THE EASTPAC...HOWEVER...THE GFS DOES NOT EVEN HINT AT H5 POSITIVE ANOMALIES UNTIL DAY 8...AND THAT IS ONLY FOR WESTERN NV. SUFFICE TO SAY...CLIMATE-WISE...DEFINITELY NOT A TYPICAL MONTH OF JULY. && .LKN WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 97/94/94/97
AREA FORECAST DISCUSSION
NWS RALEIGH NC
235 PM EDT THU JUL 23 2015 .SYNOPSIS...A WAVE OF LOW PRESSURE DEVELOPING ALONG A STALLED FRONTAL ZONE IN UPSTATE SOUTH CAROLINA WILL TRACK SLOWLY EAST TOWARD THE CAROLINA COAST THIS AFTERNOON INTO TONIGHT...THEN STALL OFFSHORE THE SOUTHEAST COAST OVER THE WEEKEND AS WEAK HIGH PRESSURE EXTENDS INTO THE REGION FROM THE NORTH. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 930 AM THURSDAY... FORECAST LARGELY ON TRACK WITH SMALL SPATIAL/TEMPORAL MODIFICATIONS. SEVERAL CLUSTERS OF SHOWERS/STORMS ARE PROGRESSING ESE OVER THE FAR NRN AND NE CWA... WITHIN A BAND OF ENHANCE LOW LEVEL MOISTURE CONVERGENCE ALONG A TIGHT THETA-E GRADIENT. PW VALUES OVER CENTRAL NC HAVE SURGED WELL BACK UP ABOVE NORMAL IN THE LAST 12 HRS... FACILITATING A VOLATILE ATMOSPHERE WITH SCATTERED TO NUMEROUS SHOWERS AND STORMS FUELED BY WEAK TO MODERATE INSTABILITY... IMPROVING DYNAMIC FORCING FOR ASCENT AS A MID LEVEL WAVE TRACKS FROM TN ACROSS THE CAROLINAS TODAY... AND IMPROVING KINEMATICS AS WELL- DEFINED SURFACE LOW PRESSURE PERSISTS ALONG THE FRONTAL ZONE OVER NRN SC. THE LATEST HRRR RUNS AND THE NSSL WRF HAVE DONE A GOOD JOB WITH CONVECTION SO FAR THIS MORNING... AND BOTH SHIFT THE GREATER STORM COVERAGE (50-60%) FROM THE NE CWA TO THE SOUTHEAST THIS AFTERNOON... WHERE LOW LEVEL MASS CONVERGENCE ENE OF THE LOW WILL BE HIGHEST WITH THE BETTER POTENTIAL FOR INSTABILITY. WILL RETAIN A TREND TO LIKELY POPS IN THIS AREA. EFFECTIVE DEEP LAYER SHEAR REMAINS MARGINAL AT 20-30 KTS BUT STILL ENOUGH FOR A THREAT OF ISOLATED STRONG TO DAMAGING WIND GUSTS WITH ANY CELLS. MODELS THEN REDEVELOP SHOWERS AND ISOLATED STORMS BACK OVER THE SW CWA THIS EVENING... AS THE MID LEVEL WAVE MOVES IN... IN CONJUNCTION WITH FORMATION OF A NEW LEE LOW OVER UPSTATE SC. WILL KEEP THE TREND BACK TOWARD HIGH POPS THIS EVENING IN OUR SW... SPREADING EAST OVERNIGHT... ALTHOUGH WILL RE-EVALUATE POTENTIAL COVERAGE THIS AFTERNOON. THE CLOUDS/PRECIP AND LIGHT NE FLOW ARE BOUND TO HOLD TEMPS DOWN BELOW NORMAL TODAY IN THE NE. EXPECT HIGHS FROM THE LOW 80S N TO NEAR 90 SOUTH... PREDICATED ON GETTING AT LEAST SOME ISOLATION NORTH THIS AFTERNOON BEHIND THE ONGOING CONVECTION. -GIH PREVIOUS DISCUSSION FROM 400 AM... OVERVIEW: DIFFICULT FORECAST. 06Z SPC MESOANALYSIS AND REMOTE SENSING DATA INDICATED NUMEROUS SMALL AMPLITUDE WAVES TRACKING EAST/ESE ALONG THE SOUTHERN FRINGE OF THE WESTERLIES THROUGH THE TN VALLEY THIS MORNING...DOWNSTREAM OF A PRONOUNCED UPPER LEVEL RIDGE ANCHORED OVER THE LOWER MIDWEST. IN RESPONSE TO DPVA ATTENDANT AN APPROACHING DISTURBANCE...A WEAK SURFACE LOW IS DEVELOPING ALONG A STALLED FRONTAL ZONE SITUATED ACROSS UPSTATE SC/SOUTHWEST NC (NEAR SHELBY NC) AND WEAK WARM ADVECTION HAS COMMENCED OVER CENTRAL NC AS 925-850 MB FLOW BACKS IN ADVANCE OF THE WAVE. WITH ADDITIONAL SMALL AMPLITUDE WAVES PRESENT UPSTREAM AND A WIDE VARIETY OF MECHANISMS (CONVECTION /LATENT HEAT RELEASE/ IN PARTICULAR) THAT CAN AFFECT THE EVOLUTION OF LOW-LEVEL HEIGHT/WIND/MOISTURE FIELDS...CONFIDENCE REMAINS LOW WITH REGARD TO CONVECTIVE COVERAGE/TIMING TODAY INTO TONIGHT. QUALITATIVELY...GIVEN THE PATTERN ONE WOULD EXPECT INCREASED CLOUD COVER...CHANCES FOR CONVECTION...AND AT OR BELOW NORMAL TEMPERATURES. CONVECTION: IN RESPONSE TO WEAK LOW-LEVEL CONVERGENCE...WARM ADVECTION... APPROACHING DPVA... AND NOCTURNAL DESTABILIZATION (DRIVEN BY LOW-LEVEL MOISTURE ADVECTION)...ISOLATED ELEVATED CONVECTION HAS ALREADY DEVELOPED IN VICINITY OF HWY 64. THE LATEST RAP GUIDANCE SUGGESTS ELEVATED CONVECTION WILL INCREASE IN COVERAGE AND INTENSITY ALONG/NORTH OF HWY 64 THROUGH 15Z AS THE EASTERN-MOST UPPER LEVEL DISTURBANCE APPROACHES...LOW-LEVEL CONVERGENCE STRENGTHENS /FLOW BACKS/...AND MOISTURE ADVECTION AIDS IN FURTHER DESTABILIZATION. AS THE LEAD DISTURBANCE PROGRESSES EAST ACROSS CENTRAL NC BY EARLY AFTERNOON...THE DEVELOPING SFC-H925 LOW IS EXPECTED TO WEAKEN/BROADEN OVER WESTERN NC...WITH AN ATTENDANT WEAKENING OF WARM ADVECTION AS LOW-LEVEL FLOW VEERS TO THE SOUTH AND WEAKENS ACROSS CENTRAL NC. HOWEVER...WEAK LOW-LEVEL CONVERGENCE AND DIURNAL DESTABILIZATION WITHIN THE WARM SECTOR SHOULD BE SUFFICIENT FOR ANY ONGOING CONVECTION TO PERSIST DURING THE EARLY/MID AFTERNOON...MOST LIKELY IN THE FORM OF SFC-BASED CONVECTION PROPAGATING SOUTHEAST (ALONG OUTFLOW) THROUGH THE COASTAL PLAIN INTO EASTERN/COASTAL NC DURING THE AFTERNOON. SEVERE: THOUGH SFC-BASED CONVECTION WILL BECOME INCREASINGLY LIKELY ALONG/SOUTH OF HWY 64 AS THE WARM SECTOR SLOWLY ADVANCES FROM CAPE FEAR INTO THE SANDHILLS 08-12Z...CONVECTION SHOULD REMAIN ELEVATED IN NATURE NORTH OF THE I-85 CORRIDOR. BY OR SHORTLY AFTER SUNRISE... MARGINAL TO MODERATE INSTABILITY AND DEEP LAYER SHEAR ~30 KT WILL CONTRIBUTE TO SUPERCELL COMPOSITE PARAMETER VALUES AS HIGH AS 1-3 (PRIMARILY SOUTH AND EAST OF THE TRIANGLE)...INDICATING THAT THE ENVIRONMENT WILL BE BASICALLY SUPPORTIVE OF SEVERE WEATHER DURING THE MORNING...PRIMARILY IN THE FORM OF WET DOWNBURSTS VIA A COMBINATION OF MOMENTUM TRANSPORT (20-25 KT MID-LEVEL FLOW) AND PRECIP LOADING...PARTICULARLY WITH PWAT VALUES AS HIGH AS 2.00- 2.25". WEAK LOW-LEVEL SPEED SHEAR ON THE EASTERN PERIPHERY OF THE SFC LOW SHOULD EFFECTIVELY LIMIT 0-1 KM SRH VALUES TO NO HIGHER THAN 50-100 M2/S2 IN CENTRAL NC THIS MORNING...THOUGH VALUES AS HIGH AS 150-200 M2/S2 WILL BE POSSIBLE THIS AFTERNOON IN COASTAL NC... PERHAPS INCLUDING PORTIONS OF THE SE COASTAL PLAIN. WITH THIS IN MIND...AN ISOLATED TOR (BRIEF/LOW-END VARIETY)...CANNOT BE RULED OUT WITH VIGOROUS UPDRAFTS (IF ANY) THIS AFTERNOON...PRIMARILY FAR SE COASTAL PLAIN (I.E. SAMPSON/WAYNE/CUMBERLAND). -VINCENT && .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... AS OF 311 AM THURSDAY... THE WEAK MID/UPPER LOW WILL SLOWLY DRIFT DEEP INTO THE SE STATES FRIDAY. MOST IF NOT ALL THE SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN OUR SE COUNTIES EARLY IN THE DAY... BEFORE SHIFTING ON SOUTHWARD AND REDEVELOPING WITH DIURNAL HEATING AGAIN FRIDAY AFTERNOON. OTHERWISE... PARTLY SUNNY WITH HIGHS IN THE MID TO UPPER 80S. PARTLY CLOUDY TO MOSTLY CLEAR SKIES EXPECTED FRIDAY NIGHT WITH LOWS IN THE MID TO UPPER 60S. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 230 PM THURSDAY... HIGH PRESSURE WILL BUILD DOWN THE APPALACHIANS...SUPPRESSING A SURFACE BOUNDARY ALL THE WAY DOWN TO NEAR THE GULF COAST. THIS PATTERN WILL PERSIST THROUGH AT LEAST THE END OF THE WEEKEND... LEADING TO MOSTLY DRY CONDITIONS. BY EARLY NEXT WEEK THE HIGH WILL BEGIN TO SHIFT OFFSHORE...BUT EXACTLY HOW QUICKLY IS STILL UNCERTAIN. REGARDLESS...MOISTURE AND INSTABILITY WILL GRADUALLY INCREASE...LEADING TO AN INCREASE IN PRECIP CHANCES. IN ADDITION... THE PERSISTENT MID/UPPER LEVEL RIDGE THAT HAS BEEN ANCHORED NEAR TEXAS...IS PROGGED TO AMPLIFY INTO THE MID MISSISSIPPI RIVER VALLEY WHICH WILL PLACE OUR REGION UNDER DEEP NORTHWESTERLY FLOW. THEREFORE MUCH OF OUR CONVECTIVE COVERAGE WILL LIKELY BE DICTATED BY UPSTREAM MCS/MCVS WHICH ARE IMPOSSIBLE TO TIME THIS FAR OUT. ALTHOUGH... MODELS ARE KEYING IN ON A SYSTEM LATE MONDAY...BUT THIS TIMING IS LIKELY TO CHANGE. THUS...WILL JUST SHOW NEAR NORMAL POPS (LOW END CHANCE) FOR ALL OF NEXT WEEK. TEMPS WILL BE NEAR NORMAL FOR MUCH OF THE PERIOD BEFORE TRENDING TO SLIGHTLY ABOVE NORMAL BY THE MIDDLE OF NEXT WEEK. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 1235 PM THURSDAY... OF MOST IMMEDIATE AVIATION CONCERN IS THE HIGH PROBABILITY OF BRIEFLY VERY POOR (LIFR) CONDITIONS (LOW CIGS AND VSBYS WITH TORRENTIAL RAIN AND GUSTY WINDS WITH ISOLATED WET MICROBURSTS POSSIBLE) IN AND NEAR STORMS IN THE NEXT HOUR OR TWO... MOST LIKELY TO AFFECT RWI/FAY THROUGH THIS AFTERNOON. SUCH CONDITIONS RECENTLY IMPACTED RDU... HOWEVER RDU SHOULD SEE A RELATIVE LULL IN STORMS THROUGH THE AFTERNOON... WITH PERHAPS SOME SHOWERS AFTER NIGHTFALL. OTHERWISE... MVFR TO IFR CIGS OVER MUCH OF CENTRAL NC (ALL BUT FAY) WILL SLOWLY LIFT BUT ARE LIKELY TO REMAIN SUB-VFR AT INT/GSO/RDU THROUGH MID AFTERNOON... THEN INCHING UP INTO LOW-END VFR CIGS AFTER 20Z... ALTHOUGH SCT-BKN MVFR CLOUDS MAY LINGER AT RDU AND PERHAPS GSO. FAY IS LIKELY TO BE ADVERSELY IMPACTED BY CLUSTERS OF SUB-VFR SHOWERS AND STORMS FOR THE MAJORITY OF THE 18Z-02Z PERIOD. AFTER 02Z... IFR STRATUS/FOG IS LIKELY AT RDU/FAY/RWI THROUGH THE OVERNIGHT... WITH A MUCH LOWER CHANCE AT INT/GSO. SCATTERED SHOWERS MAY AFFECT INTO/GSO/FAY OVERNIGHT... WITH A MUCH LOWER CHANCE AT RDU/RWI. AFTER 14Z... ANY SUB-VFR CONDITIONS ARE EXPECTED TO IMPROVE TO VFR AREAWIDE... AS HIGH PRESSURE NOSES IN FROM THE NORTH. LOOKING BEYOND 18Z FRI... VFR CONDITIONS SHOULD DOMINATE AT ALL CENTRAL NC TERMINALS AS HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTH AND NE THROUGH THE WEEKEND. STORM CHANCES RETURN LATE MON AND ESPECIALLY MON NIGHT INTO TUE AS A DISTURBANCE DROPS IN FROM THE NORTHWEST. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD/VINCENT SHORT TERM...PWB LONG TERM...KRD AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
109 PM EDT THU JUL 23 2015 .SYNOPSIS... LOW PRESSURE OVER NORTHERN SOUTH CAROLINA WILL MOVE EAST ALONG A STALLED FRONT TODAY AND OFF THE COAST TONIGHT. THIS LOW WILL PUSH THE FRONT INTO GEORGIA FOR THIS WEEKEND. HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH...WITH A DRYING TREND EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 110 PM THURSDAY...UPDATED FORECAST WITH ISSUANCE OF A SEVERE THUNDERSTORM WATCH FOR THE ENTIRE AREA...GOOD UNTIL 8 PM. PREVIOUS DISCUSSIONS FOLLOW: ANALYSIS OF MORNING SOUNDINGS AND LATEST GUIDANCE CONFIRM EARLIER FORECAST OF AN ACTIVE WEATHER DAY...ESPECIALLY THIS AFTERNOON AND EVENING...WITH THE PRIMARY THREATS BEING HEAVY RAIN AND UNUSUALLY FREQUENT LIGHTNING. DAMAGING WIND GUSTS ARE ALSO A POSSIBILITY. NO CHANGES NEEDED YET TO THE FORECAST. PREVIOUS DISCUSSION FOLLOWS: LOW PRESSURE CENTERED OVER THE SC SANDHILLS WILL MOVE EASTWARD ALONG A STATIONARY FRONT TODAY...EXITING INTO THE ATLANTIC OCEAN TONIGHT. MODELS ARE ALMOST UNANIMOUS IN THEIR DEPICTION OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING WITHIN A REGION OF LOW-LEVEL CONVERGENCE AND LARGE INSTABILITY OVER SOUTHERN NORTH CAROLINA JUST NORTH OF THE STATIONARY FRONT LATE THIS MORNING. SURFACE CAPE IS PREDICTED TO GROW AS LARGE AS 3000 J/KG WITH LIFTED INDICES TO -6. 700 MB WINDS INCREASING TO 25 KT SHOULD INCREASE BULK SHEAR VALUES JUST ENOUGH TO PRODUCE ORGANIZED MULTICELLULAR STORMS TODAY...WITH COLD POOL EFFECTS LIKELY PUSHING THE CLUSTER SOUTHEASTWARD ACROSS THE CAPE FEAR AREA EARLY THIS AFTERNOON AND INTO NORTHEASTERLY SOUTH CAROLINA BY MID TO LATE AFTERNOON. IMPACTS FROM THESE STORMS COULD BE CONSIDERABLE. COMPUTED EQUILIBRIUM PARCEL HEIGHTS NEAR 50000 FT AND LOTS OF INSTABILITY ABOVE THE -20C LEVEL INDICATES THESE STORMS COULD BE ENORMOUS LIGHTNING PRODUCERS WITH PLENTY OF ICE/GRAUPEL GENERATION ALOFT. ALTHOUGH NO DRY LAYERS ARE EVIDENT IN FORECAST SOUNDINGS PRECIPITATION LOADING RESULTING FROM SUCH VIGOROUS CONVECTION SHOULD PRODUCE GUSTY WINDS...PARTICULARLY AS THE STORMS ARE SHOWN IN THE HIGH RESOLUTION WRF-NMM...WRF-ARW...AND HRRR MODELS TO FORM A LARGE MASSED OUTFLOW PUSHING SOUTHEASTWARD TO THE COAST. WITH THE SYNOPTIC FRONT STALLED ACROSS THE AREA AND ANTICIPATED BOUNDARY COLLISIONS THE STORMS SHOULD ALSO BE HEAVY RAIN MAKERS WITH LOCALIZED FLOODING POSSIBLE. FORECAST RAIN CHANCES HAVE BEEN INCREASED TO 80 PERCENT ACROSS SE NORTH CAROLINA...FOCUSED ON THE NOON-4 PM TIMEFRAME. CONVECTION SHOULD TAKE SEVERAL ADDITIONAL HOURS TO PROPAGATE SOUTHWARD AND AFFECT NE SOUTH CAROLINA WHICH WILL BE LOCATED SOUTH OF THE STATIONARY FRONT. THIS MEANS SEVERAL ADDITIONAL HOURS OF HOT SUNSHINE...AND TEMPERATURES HERE WILL RISE INTO THE MID TO UPPER 90S. FORECAST HEAT INDICES ARE JUST BELOW 105-DEGREE HEAT ADVISORY CRITERIA ACROSS GEORGETOWN...WILLIAMSBURG AND SOUTHERN FLORENCE COUNTIES. AN UPPER LEVEL DISTURBANCE CURRENTLY PRODUCING THUNDERSTORMS OVER CENTRAL TENNESSEE WILL REACH THE EASTERN CAROLINAS THIS EVENING. THIS COULD HELP CONVECTIVE ACTIVITY TO PERSIST INTO THE EVENING HOURS EVEN AFTER THE ATMOSPHERE PRETTY MUCH OVERTURNS DURING THE AFTERNOON. THE LOW WILL SCOOT EASTWARD ALONG THE FRONT OFFSHORE AFTER MIDNIGHT WITH SURFACE WINDS TURNING NORTHWESTERLY...QUITE AN ODD DIRECTION FOR THE CAROLINAS IN THE MIDDLE OF SUMMER. THIS IS THE THIRD COLD FRONTAL PASSAGE OF JULY! && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LATEST MODELS SHOW LOW JUST OFF THE CAPE FEAR COAST FRI MORNING. EXPECT BEST CONVECTION OVER THE COASTAL WATERS WITH MOST AREAS SEEING A DEEP FLOW OF DRIER AIR ADVECTING IN FROM THE NORTH. MID TO UPPER TROUGH WILL PUSH LOW PRESSURE ALONG LINGERING BOUNDARY SOUTH AND EAST OF AREA THROUGH THE DAY...BUT PLENTY OF RESIDUAL LOW LEVEL MOISTURE FROM PREVIOUS DAYS CONVECTION WILL SLOW CLEARING AND COMBINE WITH CONVERGENCE ASSOCIATED WITH LOW AND OTHER LOCALIZED BOUNDARIES SUCH AS THE SEA BREEZE TO PRODUCE SOME SHWRS/TSTMS. LOOKS LIKE BEST CHC WILL MOVE SOUTH THROUGH THE DAY AS HIGH PRESSURE BEGINS TO BUILD DOWN FROM THE NORTH BUT MAY NOT BE FAST ENOUGH TO ELIMINATE POPS FROM FORECAST. NAM SHOWS MAIN FOCUS OF CONVECTION ALONG COASTAL SOUTH CAROLINA WHERE BEST CONVERGENCE SHOULD BE AS WE DEVELOP A N-NE FLOW. MAY SEE ENOUGH SUBSIDENCE AND DRY AIR THROUGH THE MID TO UPPER LEVELS BY LATE FRI TO ALLOW FOR ONLY A DECENT STRATOCU FIELD OVER NC. PCP WATER VALUES OVER 2 INCHES EARLY FRI MORNING WILL DROP DOWN CLOSE TO AN INCH BY SAT MORNING. LINGERING CLOUDS AND PCP WILL KEEP TEMPS IN THE 80S MOST OF THE DAY BUT PLACES THAT SEE SOME SUN MAKE AN APPEARANCE WILL REACH CLOSE TO 90. BY LATE FRI INTO FRI NIGHT...PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID TO UPPER LEVELS WILL REACH DOWN OVER THE FORECAST AREA AS DRY HIGH PRESSURE AT THE SFC NOSES DOWN FROM THE NORTH. WILL SHOW CLEARING AT THIS TIME AND WILL KEEP PCP OUT OF FORECAST THROUGH THE REMAINDER OF THE WEEKEND. PLENTY OF BRIGHT JULY SUNSHINE WILL DRIVE TEMPS UP NEAR NORMAL...CLOSE TO 90 BUT SFC DEWPOINT TEMPS WILL BE RUNNING IN THE LOW TO MID 60S MOST PLACES WHICH WILL MAKE FOR A MUCH MORE REFRESHING DAY THAN PREVIOUS ONES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 330 AM THURSDAY...CENTER OF HIGH PRESSURE NOSING DOWN FROM THE NORTH WILL SHIFT OFF THE MID ATLANTIC COAST ALLOWING WINDS TO COME AROUND TO A MORE ON SHORE NE TO E FLOW. WEAK HIGH PRESSURE WILL CONTINUE TO REACH DOWN INTO THE CAROLINAS THROUGH MID WEEK AS LEE SIDE TROUGH BECOMES MORE PRONOUNCED. RIDGING IN THE MID TO UPPER LEVELS OVER THE MID WEST WILL BUILD EASTWARD OVER THE WEEKEND...BUT AS IT BECOMES MORE AMPLIFIES UP THROUGH THE UPPER MIDWEST BY TUES...A DEEPER NW FLOW ALOFT WILL ALLOW SOME CLOUDS AND SHORTWAVE ENERGY TO SNEAK INTO AREA BUT RIDGE WILL BUILD BACK EAST AND UP THE EAST COAST THROUGH MID WEEK AND THEREFORE MAY INTRODUCE INCREASED CLOUDS AND SHWRS FOR TUES/WED TIME FRAME BUT OVERALL SHWR ACTIVITY SHOULD REMAIN MORE ISOLATED HEADING INTO MID WEEK AS RIDGE BUILDS BACK IN. THE ON SHORE FLOW DEVELOPING THROUGH THE PERIOD WILL AID IN BRINGING DEWPOINT TEMPS BACK UP CLOSER TO 70 OR SO...HELPING TO INCREASE AFTN CU AND CHC OF SOME CONVECTIVE DEVELOPMENT. TEMPS WILL BASICALLY REMAIN AROUND CLIMO. && .AVIATION /17Z THURSDAY THROUGH MONDAY/... AS OF 18Z...TERMINALS ARE CURRENTLY VFR. CONVECTION HAS SO FAR STAYED TO THE NORTH. A WEAK FRONT IS LOCATED FROM NEAR KLBT TO KILM. THUNDERSTORMS ARE A SURE BET THIS AFTERNOON ALONG AND EAST OF THE FRONT WITH HIGHEST CONFIDENCE OF OCCURRENCE AT KILM AND TO A LESSER EFFECT KLBT. STORMS SHOULD PRODUCE SUFFICIENT OUTFLOWS TO ALLOW DEVELOPMENT TO THE S-SW TOWARDS KFLO AND MORE LIKELY KCRE/KMYR AS THE AFTERNOON PROGRESSES. SHOWER POTENTIAL WILL PERSIST INTO THE EVENING HOURS. WINDS BECOME LIGHT AND VARIABLE OR LIGHT NW LATE AFTERNOON AND EVENING. THERE IS A FOG POTENTIAL MAINLY KFLO/KLBT OVERNIGHT WITH LOW TO MODERATE POTENTIAL FOR IFR. VFR SHORTLY AFTER SUNRISE WITH N WINDS. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM ISOLATED CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 110 PM THURSDAY...UPDATED FORECAST WITH ISSUANCE OF A SEVERE THUNDERSTORM WATCH FOR THE ENTIRE AREA...GOOD UNTIL 8 PM. PREVIOUS DISCUSSIONS FOLLOW: LATEST OBS SHOW 2 FT SEAS WITH SSE WINDS OF 10 TO 15 KTS. FORECAST ON TRACK WITH NO CHANGES NEEDED. PREVIOUS DISCUSSION FOLLOWS: LOW PRESSURE CENTERED OVER THE SOUTH CAROLINA SANDHILLS WILL MOVE EASTWARD TODAY ALONG A WEAK STATIONARY FRONT. THIS FRONT CURRENTLY SITS JUST NORTH OF CAPE FEAR AND IS OUTLINED BY A SHIFT IN WIND DIRECTIONS FROM SOUTHERLY ALONG THE SC COAST TO SOUTHEASTERLY FROM WRIGHTSVILLE BEACH AND SURF CITY TO THE OUTER BANKS. AS INLAND AREAS HEAT UP QUICKLY THIS MORNING ATMOSPHERIC CONDITIONS ARE STRONGLY SUPPORTIVE OF A LARGE CLUSTER OF THUNDERSTORMS DEVELOPING ACROSS SOUTHERN NORTH CAROLINA...DROPPING SOUTHEASTWARD AND AFFECTING THE COASTAL WATERS DURING THE AFTERNOON. THESE STORMS WILL LIKELY CONTAIN LARGE AMOUNTS OF LIGHTNING AND SUBSTANTIAL VISIBILITY RESTRICTIONS IN HEAVY RAIN. SEVERAL OF THE HIGH- RESOLUTION MODELS INDICATE THE POTENTIAL FOR A STRONG GUST FRONT AT THE LEADING EDGE OF THE STORMS WHICH MAY PROMPT SPECIAL MARINE WARNINGS THIS AFTERNOON. MARINERS IN THE CAPE FEAR AREA SHOULD EXPECT THE LARGEST IMPACT FROM THESE STORMS BETWEEN 1-3 PM...WITH THE GRAND STAND AND GEORGETOWN AREAS A COUPLE HOURS LATER. LATE TONIGHT AS THE LOW SHIFTS EASTWARD ALONG THE FRONT AND ENTERS THE ATLANTIC OCEAN SURFACE WINDS WILL SHIFT NORTHWESTERLY AND MAY INCREASE TO 10-15 KT LATE. OUTSIDE OF THUNDERSTORMS SEAS SHOULD AVERAGE 2 FEET TODAY...AND 2-3 FEET TONIGHT. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 330 AM THURSDAY...LOW PRESSURE ALONG LINGERING BOUNDARY WILL SLIP FARTHER SOUTH THROUGH THE DAY ON FRIDAY. NORTHEAST FLOW WILL DEVELOP BEHIND THIS BOUNDARY AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH THROUGH THE WEEKEND. EXPECT WINDS TO REMAIN BELOW 15 KTS ACROSS MOST OF THE WATERS...BUT THERE SHOULD BE SOME PERIODS OF HIGHER WAVES...UP CLOSER TO 20 KTS. THE WINDS WILL BEGIN TO VEER AROUND FROM THE NE TO E. THE PERSISTENT STRONGER NE TO E ON SHORE FLOW WILL PRODUCE SEAS UP TO 3 TO 5 FT...ESPECIALLY THROUGH SAT NIGHT. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 330 AM...HIGH PRESSURE EXTENDING DOWN INTO THE CAROLINAS FROM THE NORTHEAST WILL MOVE FARTHER EAST THROUGH THE PERIOD...ALLOWING WINDS TO LIGHTEN AND VEER TO THE EAST. THE WINDS SHOULD DECREASE TO 10 KTS OR LESS MOST OF THE TIME...BUT SEA BREEZE EACH AFTN WILL ACT TO ENHANCE OVERALL ON SHORE FLOW. EXPECT SEAS TO BE COMING DOWN AS WINDS LIGHTEN HEADING THROUGH LATE SUNDAY INTO MONDAY. THEREFORE SEAS UP TO 3 TO 5 FT EARLY SUNDAY SHOULD DROP TO 2 TO 4 FT SUN NIGHT. AS SHORTER PERIOD WINDWAVE DIMINISHES THROUGH MONDAY AND WNA CONTINUES TO SHOW A LONGER PERIOD UP TO 11 SEC WAVE MIXING IN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...REK/TRA SHORT TERM...RGZ LONG TERM...RGZ AVIATION...MRR MARINE...REK/TRA/RGZ
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1235 PM EDT THU JUL 23 2015 .SYNOPSIS...A WAVE OF LOW PRESSURE DEVELOPING ALONG A STALLED FRONTAL ZONE IN UPSTATE SOUTH CAROLINA WILL TRACK SLOWLY EAST TOWARD THE CAROLINA COAST THIS AFTERNOON INTO TONIGHT...THEN STALL OFFSHORE THE SOUTHEAST COAST OVER THE WEEKEND AS WEAK HIGH PRESSURE EXTENDS INTO THE REGION FROM THE NORTH. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 930 AM THURSDAY... FORECAST LARGELY ON TRACK WITH SMALL SPATIAL/TEMPORAL MODIFICATIONS. SEVERAL CLUSTERS OF SHOWERS/STORMS ARE PROGRESSING ESE OVER THE FAR NRN AND NE CWA... WITHIN A BAND OF ENHANCE LOW LEVEL MOISTURE CONVERGENCE ALONG A TIGHT THETA-E GRADIENT. PW VALUES OVER CENTRAL NC HAVE SURGED WELL BACK UP ABOVE NORMAL IN THE LAST 12 HRS... FACILITATING A VOLATILE ATMOSPHERE WITH SCATTERED TO NUMEROUS SHOWERS AND STORMS FUELED BY WEAK TO MODERATE INSTABILITY... IMPROVING DYNAMIC FORCING FOR ASCENT AS A MID LEVEL WAVE TRACKS FROM TN ACROSS THE CAROLINAS TODAY... AND IMPROVING KINEMATICS AS WELL- DEFINED SURFACE LOW PRESSURE PERSISTS ALONG THE FRONTAL ZONE OVER NRN SC. THE LATEST HRRR RUNS AND THE NSSL WRF HAVE DONE A GOOD JOB WITH CONVECTION SO FAR THIS MORNING... AND BOTH SHIFT THE GREATER STORM COVERAGE (50-60%) FROM THE NE CWA TO THE SOUTHEAST THIS AFTERNOON... WHERE LOW LEVEL MASS CONVERGENCE ENE OF THE LOW WILL BE HIGHEST WITH THE BETTER POTENTIAL FOR INSTABILITY. WILL RETAIN A TREND TO LIKELY POPS IN THIS AREA. EFFECTIVE DEEP LAYER SHEAR REMAINS MARGINAL AT 20-30 KTS BUT STILL ENOUGH FOR A THREAT OF ISOLATED STRONG TO DAMAGING WIND GUSTS WITH ANY CELLS. MODELS THEN REDEVELOP SHOWERS AND ISOLATED STORMS BACK OVER THE SW CWA THIS EVENING... AS THE MID LEVEL WAVE MOVES IN... IN CONJUNCTION WITH FORMATION OF A NEW LEE LOW OVER UPSTATE SC. WILL KEEP THE TREND BACK TOWARD HIGH POPS THIS EVENING IN OUR SW... SPREADING EAST OVERNIGHT... ALTHOUGH WILL RE-EVALUATE POTENTIAL COVERAGE THIS AFTERNOON. THE CLOUDS/PRECIP AND LIGHT NE FLOW ARE BOUND TO HOLD TEMPS DOWN BELOW NORMAL TODAY IN THE NE. EXPECT HIGHS FROM THE LOW 80S N TO NEAR 90 SOUTH... PREDICATED ON GETTING AT LEAST SOME ISOLATION NORTH THIS AFTERNOON BEHIND THE ONGOING CONVECTION. -GIH PREVIOUS DISCUSSION FROM 400 AM... OVERVIEW: DIFFICULT FORECAST. 06Z SPC MESOANALYSIS AND REMOTE SENSING DATA INDICATED NUMEROUS SMALL AMPLITUDE WAVES TRACKING EAST/ESE ALONG THE SOUTHERN FRINGE OF THE WESTERLIES THROUGH THE TN VALLEY THIS MORNING...DOWNSTREAM OF A PRONOUNCED UPPER LEVEL RIDGE ANCHORED OVER THE LOWER MIDWEST. IN RESPONSE TO DPVA ATTENDANT AN APPROACHING DISTURBANCE...A WEAK SURFACE LOW IS DEVELOPING ALONG A STALLED FRONTAL ZONE SITUATED ACROSS UPSTATE SC/SOUTHWEST NC (NEAR SHELBY NC) AND WEAK WARM ADVECTION HAS COMMENCED OVER CENTRAL NC AS 925-850 MB FLOW BACKS IN ADVANCE OF THE WAVE. WITH ADDITIONAL SMALL AMPLITUDE WAVES PRESENT UPSTREAM AND A WIDE VARIETY OF MECHANISMS (CONVECTION /LATENT HEAT RELEASE/ IN PARTICULAR) THAT CAN AFFECT THE EVOLUTION OF LOW-LEVEL HEIGHT/WIND/MOISTURE FIELDS...CONFIDENCE REMAINS LOW WITH REGARD TO CONVECTIVE COVERAGE/TIMING TODAY INTO TONIGHT. QUALITATIVELY...GIVEN THE PATTERN ONE WOULD EXPECT INCREASED CLOUD COVER...CHANCES FOR CONVECTION...AND AT OR BELOW NORMAL TEMPERATURES. CONVECTION: IN RESPONSE TO WEAK LOW-LEVEL CONVERGENCE...WARM ADVECTION... APPROACHING DPVA... AND NOCTURNAL DESTABILIZATION (DRIVEN BY LOW-LEVEL MOISTURE ADVECTION)...ISOLATED ELEVATED CONVECTION HAS ALREADY DEVELOPED IN VICINITY OF HWY 64. THE LATEST RAP GUIDANCE SUGGESTS ELEVATED CONVECTION WILL INCREASE IN COVERAGE AND INTENSITY ALONG/NORTH OF HWY 64 THROUGH 15Z AS THE EASTERN-MOST UPPER LEVEL DISTURBANCE APPROACHES...LOW-LEVEL CONVERGENCE STRENGTHENS /FLOW BACKS/...AND MOISTURE ADVECTION AIDS IN FURTHER DESTABILIZATION. AS THE LEAD DISTURBANCE PROGRESSES EAST ACROSS CENTRAL NC BY EARLY AFTERNOON...THE DEVELOPING SFC-H925 LOW IS EXPECTED TO WEAKEN/BROADEN OVER WESTERN NC...WITH AN ATTENDANT WEAKENING OF WARM ADVECTION AS LOW-LEVEL FLOW VEERS TO THE SOUTH AND WEAKENS ACROSS CENTRAL NC. HOWEVER...WEAK LOW-LEVEL CONVERGENCE AND DIURNAL DESTABILIZATION WITHIN THE WARM SECTOR SHOULD BE SUFFICIENT FOR ANY ONGOING CONVECTION TO PERSIST DURING THE EARLY/MID AFTERNOON...MOST LIKELY IN THE FORM OF SFC-BASED CONVECTION PROPAGATING SOUTHEAST (ALONG OUTFLOW) THROUGH THE COASTAL PLAIN INTO EASTERN/COASTAL NC DURING THE AFTERNOON. SEVERE: THOUGH SFC-BASED CONVECTION WILL BECOME INCREASINGLY LIKELY ALONG/SOUTH OF HWY 64 AS THE WARM SECTOR SLOWLY ADVANCES FROM CAPE FEAR INTO THE SANDHILLS 08-12Z...CONVECTION SHOULD REMAIN ELEVATED IN NATURE NORTH OF THE I-85 CORRIDOR. BY OR SHORTLY AFTER SUNRISE... MARGINAL TO MODERATE INSTABILITY AND DEEP LAYER SHEAR ~30 KT WILL CONTRIBUTE TO SUPERCELL COMPOSITE PARAMETER VALUES AS HIGH AS 1-3 (PRIMARILY SOUTH AND EAST OF THE TRIANGLE)...INDICATING THAT THE ENVIRONMENT WILL BE BASICALLY SUPPORTIVE OF SEVERE WEATHER DURING THE MORNING...PRIMARILY IN THE FORM OF WET DOWNBURSTS VIA A COMBINATION OF MOMENTUM TRANSPORT (20-25 KT MID-LEVEL FLOW) AND PRECIP LOADING...PARTICULARLY WITH PWAT VALUES AS HIGH AS 2.00- 2.25". WEAK LOW-LEVEL SPEED SHEAR ON THE EASTERN PERIPHERY OF THE SFC LOW SHOULD EFFECTIVELY LIMIT 0-1 KM SRH VALUES TO NO HIGHER THAN 50-100 M2/S2 IN CENTRAL NC THIS MORNING...THOUGH VALUES AS HIGH AS 150-200 M2/S2 WILL BE POSSIBLE THIS AFTERNOON IN COASTAL NC... PERHAPS INCLUDING PORTIONS OF THE SE COASTAL PLAIN. WITH THIS IN MIND...AN ISOLATED TOR (BRIEF/LOW-END VARIETY)...CANNOT BE RULED OUT WITH VIGOROUS UPDRAFTS (IF ANY) THIS AFTERNOON...PRIMARILY FAR SE COASTAL PLAIN (I.E. SAMPSON/WAYNE/CUMBERLAND). -VINCENT && .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... AS OF 311 AM THURSDAY... THE WEAK MID/UPPER LOW WILL SLOWLY DRIFT DEEP INTO THE SE STATES FRIDAY. MOST IF NOT ALL THE SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN OUR SE COUNTIES EARLY IN THE DAY... BEFORE SHIFTING ON SOUTHWARD AND REDEVELOPING WITH DIURNAL HEATING AGAIN FRIDAY AFTERNOON. OTHERWISE... PARTLY SUNNY WITH HIGHS IN THE MID TO UPPER 80S. PARTLY CLOUDY TO MOSTLY CLEAR SKIES EXPECTED FRIDAY NIGHT WITH LOWS IN THE MID TO UPPER 60S. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 1255 AM THURSDAY... DRY WEATHER IS STILL ANTICIPATED GIVEN THE FLOW PATTERN OVER THE REGION SATURDAY AND SUNDAY. IT APPEARS THAT THERE WILL BE A SLOWLY INCREASING CHANCE OF MAINLY DIURNAL SHOWERS AND THUNDERSTORMS MONDAY THROUGH WEDNESDAY. HOWEVER... THERE CONTINUES TO BE SOME MODEL SPREAD IN WHEN THE MOISTURE/INSTABILITY WILL INCREASE ENOUGH FOR THIS TO OCCUR. WE WILL CONTINUE THE CURRENT LOW CHANCE POP FOR PM THUNDERSTORMS MONDAY THROUGH WEDNESDAY. TEMPERATURES SHOULD BE NEAR THE 30 YEAR AVERAGES FOR LATE JULY THIS WEEKEND... AND ONLY SLOWLY RISE TO ABOVE NORMAL BY TUE-WED. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 1235 PM THURSDAY... OF MOST IMMEDIATE AVIATION CONCERN IS THE HIGH PROBABILITY OF BRIEFLY VERY POOR (LIFR) CONDITIONS (LOW CIGS AND VSBYS WITH TORRENTIAL RAIN AND GUSTY WINDS WITH ISOLATED WET MICROBURSTS POSSIBLE) IN AND NEAR STORMS IN THE NEXT HOUR OR TWO... MOST LIKELY TO AFFECT RWI/FAY THROUGH THIS AFTERNOON. SUCH CONDITIONS RECENTLY IMPACTED RDU... HOWEVER RDU SHOULD SEE A RELATIVE LULL IN STORMS THROUGH THE AFTERNOON... WITH PERHAPS SOME SHOWERS AFTER NIGHTFALL. OTHERWISE... MVFR TO IFR CIGS OVER MUCH OF CENTRAL NC (ALL BUT FAY) WILL SLOWLY LIFT BUT ARE LIKELY TO REMAIN SUB-VFR AT INT/GSO/RDU THROUGH MID AFTERNOON... THEN INCHING UP INTO LOW-END VFR CIGS AFTER 20Z... ALTHOUGH SCT-BKN MVFR CLOUDS MAY LINGER AT RDU AND PERHAPS GSO. FAY IS LIKELY TO BE ADVERSELY IMPACTED BY CLUSTERS OF SUB-VFR SHOWERS AND STORMS FOR THE MAJORITY OF THE 18Z-02Z PERIOD. AFTER 02Z... IFR STRATUS/FOG IS LIKELY AT RDU/FAY/RWI THROUGH THE OVERNIGHT... WITH A MUCH LOWER CHANCE AT INT/GSO. SCATTERED SHOWERS MAY AFFECT INTO/GSO/FAY OVERNIGHT... WITH A MUCH LOWER CHANCE AT RDU/RWI. AFTER 14Z... ANY SUB-VFR CONDITIONS ARE EXPECTED TO IMPROVE TO VFR AREAWIDE... AS HIGH PRESSURE NOSES IN FROM THE NORTH. LOOKING BEYOND 18Z FRI... VFR CONDITIONS SHOULD DOMINATE AT ALL CENTRAL NC TERMINALS AS HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTH AND NE THROUGH THE WEEKEND. STORM CHANCES RETURN LATE MON AND ESPECIALLY MON NIGHT INTO TUE AS A DISTURBANCE DROPS IN FROM THE NORTHWEST. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD/VINCENT SHORT TERM...PWB LONG TERM...PWB AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
300 PM CDT THU JUL 23 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 300 PM CDT THU JUL 23 2015 THIS EVENING AND TONIGHT SEVERE POTENTIAL...FRONT IS CURRENTLY (20Z) LOCATED FROM NORTH OF WINNIPEG INTO NORTH CENTRAL NORTH DAKOTA TO NEAR DICKINSON. THUNDERSTORMS HAVE ALREADY INITIATED ALONG THIS FEATURE IN CANADA (WHERE THE MID- LEVEL CAP IS WEAKER)...AND WOULD EXPECT THAT THE FORCING ALONG THIS FEATURE IN NORTH DAKOTA COMBINED WITH A WEAKENING CAP WILL BE ABLE TO INITIATE STORMS BY MID-LATE AFTERNOON ACROSS CENTRAL NORTH DAKOTA. MLCAPE 2000-4000 J/KG EXISTS AHEAD OF THIS FEATURE (AT LEAST ALONG AND WEST OF THE RED RIVER VALLEY). ANTICIPATE ACTIVITY THAT DEVELOPS WEST OF THE REGION WILL ORGANIZE INTO SOME SORT OF EASTWARD MOVING COMPLEX...CONSIDERING THAT GUIDANCE INDICATES INCREASING DEEP LAYER SHEAR (40 KNOT 500MB JET) AND A DEVELOPING 40 KNOT 850MB JET. IN FACT...HRRR HAS BEEN CONSISTENT RUN TO RUN SHOWING A QLCS EVENT WITH AREAS OF SEVERE WIND GUSTS ACROSS E ND AND ADJACENT PORTIONS OF MN. SPC IN ON BOARD WITH THIS ASSESSMENT INDICATING AN ENHANCED RISK OF SEVERE STORMS FOR DAMAGING WINDS. QLCS TORNADO ALSO POSSIBLE...ESPECIALLY SE ND WHERE 0-3KM SHEAR WILL BE WEST 30-40 KNOTS. BRIEF HEAVY RAIN LIKELY...BUT THE SYSTEM APPEARS IT WILL BE MORE PROGRESSIVE TO PREVENT WIDESPREAD FLASH FLOOD POTENTIAL. USED THE LATEST HRRR FOR TIMING OF POPS. FRIDAY-FRIDAY NIGHT...ZONAL FLOW DEVELOPS AND ALTHOUGH THUNDERSTORMS MAY BE POSSIBLE WITH ANY WEAK FAST MOVING WAVE...MOST GUIDANCE INDICATES INSTABILITY (LOW LEVEL MOIST AXIS) WILL BE EAST OF THE REGION BY 18Z FRIDAY. KEPT WITH A MOSTLY DRY FORECAST AND COOLER (NEAR NORMAL) TEMPERATURES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 300 PM CDT THU JUL 23 2015 SATURDAY-SUNDAY...ZONAL FLOW CONTINUES...WITH NO STRONG SIGNAL FOR PRECIPITATION AMONG THE MODELS. THERE ARE SOME MODEL DIFFERENCES SATURDAY/SATURDAY NIGHT WITH LOW LEVEL MOISTURE RETURN AND UPPER LEVEL ENERGY. KEPT A CHANCE FOR THUNDER ACROSS THE SOUTHERN FA...BUT CONFIDENCE NOT HIGH. TEMPERATURES AGAIN CLIMB TO ABOVE NORMAL VALUES. SUNDAY NIGHT-THURSDAY...UPPER RIDGING AND PERSISTENT LOW-LEVEL SOUTHERLY FLOW WILL STILL KEEP WARM AND HUMID AIR IN PLACE FOR THE FIRST DAY OF THE EXTENDED PERIOD...WITH HIGHS WELL UP IN THE 80S. STRONG UPPER WAVE LIFTING FROM PAC NW TO SOUTHERN CANADA WILL CLOSE OFF...WITH AN ANOMALOUSLY DEEP SURFACE LOW INDICATED NORTHERN HIGH PLAINS BY MON NIGHT INTO TUESDAY. STACKED LOW WILL BE NEARLY STATIONARY WEST OF THE FORECAST AREA WHILE SEVERAL BOUNDARIES MOVE TO THE EAST OVER NORTHERN PLAINS AND INTO MINNESOTA TUE/WED WITH CHC POPS PREVAILING. THE COMPLEX IS LIKELY TO MOVE THROUGH THE REGION WED NIGHT INTO THURS ACCOMPANIED BY A GUSTY WIND SHIFT TO NW AND A DRIER REGIME TO END THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1255 PM CDT THU JUL 23 2015 GUSTY SSE WINDS TO DIMINISH ARD SUNSET AS A LINE OF THUNDERSTORMS PROGRESSES FROM WEST TO EAST TOWARD DEVILS LK BASIN. TEMPO FOR TSRA INCLUDED FROM MID EVENING THROUGH OVERNIGHT FROM KDVL THROUGH VALLEY SITES. WIND SHIFT TO NW WILL OCCUR BEHIND BOUNDARY FROM LATE NIGHT INTO EARLY FRI MORNING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...TG LONG TERM...WJB/TG AVIATION...WJB
AREA FORECAST DISCUSSION
NWS NORMAN OK
328 PM CDT THU JUL 23 2015 .DISCUSSION... WITH AN UPPER LEVEL RIDGE FIRMLY IN PLACE...THIS FORECAST DISCUSSION WILL BE LEFT FAIRLY DRY. ONLY CHALLENGE AT THE MOMENT WILL BE THE CHANCE OF A FEW SHOWERS OR THUNDERSTORMS CLIPPING FAR NORTH CENTRAL OK LATER THIS EVENING/OVERNIGHT AS A WEAK COMPLEX OF STORMS MAY MAINTAIN AND SLIDE S/SE ACROSS CENTRAL KS. CONFIDENCE IS LOW AT THE MOMENT GIVEN AS THE VAST MAJORITY OF SHORT RANGE GUIDANCE IS NOT TOO KEEN ON DEVELOPING PRECIP. THE HRRR IS THE OUTLIER... BUT GIVEN ITS OVER CONVECTIVE NATURE WITH OUR WEAK FORCING REGIME... DO NOT FEEL CONFIDENT AT THE MOMENT TO PLACE ANY MENTION IN THE FORECAST. HEAT IS THE BIG STORY GOING INTO THE WEEKEND AS TEMPERATURES NEAR 100 DEGREES AND HEAT INDICES NEAR 105 DEGREES. A HEAT ADVISORY IS IN EFFECT FOR EASTERN PARTS OF THE CWA FOR FRIDAY...AND FUTURE HEAT ADVISORIES MAY BE NEEDED THROUGH THE WEEKEND. BY MID WEEK NEXT WEEK...A TROUGH TRIES TO MOVE THROUGH...WEAKENING THE RIDGE JUST ENOUGH TO BRING IN SLIGHT CHANCE POPS AND COOL TEMPERATURES BY A FEW DEGREES. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 76 98 75 98 / 0 0 0 0 HOBART OK 77 102 75 101 / 0 0 0 0 WICHITA FALLS TX 78 100 77 100 / 0 0 0 0 GAGE OK 74 101 73 100 / 0 10 10 10 PONCA CITY OK 77 100 77 100 / 0 0 0 0 DURANT OK 77 99 76 100 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR OKZ006>008-011>013- 017>020-024>026-029>032-042-043-047-048-051-052. HEAT ADVISORY FROM 1 PM TO 8 PM CDT FRIDAY FOR OKZ005>008- 011>013-017>020-024>026-029>032-042-043-047-048-051-052. TX...NONE. && $$ MAD/JTK
AREA FORECAST DISCUSSION
NWS NORMAN OK
1244 PM CDT THU JUL 23 2015 .DISCUSSION... THE 18Z TAF DISCUSSION IS BELOW. && .AVIATION... ISOLATED STORMS WILL CONTINUE TO AFFECT KPNC THROUGH ABOUT 19Z. OTHERWISE...A RIDGE ALOFT WILL KEEP CLOUDS MINIMAL THROUGH THE TAF PERIOD. WINDS WILL FOLLOW A NORMAL DIURNAL PATTERN. MAHALE && .PREV DISCUSSION... /ISSUED 435 AM CDT THU JUL 23 2015/ DISCUSSION... THE STORMS THIS MORNING SHOULD BE ONE LAST HOORAH FOR CONVECTION FOR A FEW DAYS. STORMS WILL AT LEAST PERSIST ACROSS NORTH CENTRAL OKLAHOMA WHILE THE HRRR AND RAP SHOW THE CHANCE OF STORMS DEVELOPING FARTHER SOUTH AS WELL. DID EXPAND THE SLIGHT CHANCE POPS FARTHER SOUTH GIVEN THE HRRR AND RAP SIGNAL. EXPECT STORMS TO HAVE MOVED EAST OF THE AREA AND/OR DISSIPATED BY EARLY THIS AFTERNOON. FOCUS REMAINS ON HEAT OVER THE NEXT FEW DAYS. GFS INITIALIZED DEWPOINTS WAY TOO LOW THIS MORNING OVER THE AREA SO BLENDED WENT WELL ABOVE BLENDED INITIALIZATION FOR DEWPOINTS. TEMPERATURES WILL BE HIGH THIS AFTERNOON ALTHOUGH NOT CRAZY HIGH... BUT DEWPOINTS EXPECTED TO REMAIN IN THE LOW TO MID 70S WILL BRING HEAT INDEX VALUES OVER 110 IN SOME AREAS. HAVE ISSUED A HEAT ADVISORY FOR THE NORTH CENTRAL... CENTRAL AND SOUTHEAST FOR THIS AFTERNOON. HEAT WILL CONTINUE TO BE THE PRIMARY WEATHER STORY OVER THE NEXT FEW DAYS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 96 75 98 75 / 20 0 0 0 HOBART OK 100 76 102 75 / 10 10 0 0 WICHITA FALLS TX 99 77 100 77 / 10 10 0 0 GAGE OK 99 73 100 73 / 10 10 10 10 PONCA CITY OK 95 77 99 77 / 40 10 0 0 DURANT OK 98 77 99 76 / 10 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR OKZ006>008-011>013- 017>020-024>026-029>032-042-043-047-048-051-052. TX...NONE. && $$ 23/04/10
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
229 PM MDT THU JUL 23 2015 .SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT ISSUED AT 227 PM MDT THU JUL 23 2015 UPPER LEVEL ANALYSIS HAS A BROAD AREA OF HIGH PRESSURE OVER THE SOUTHERN PLAINS WITH A SHORTWAVE TROF OVER THE PACIFIC NORTHWEST. WATER VAPOR IMAGERY SHOWS A SHORTWAVE PUSHING INTO SOUTHERN MONTANA WITH SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. AT THE SURFACE...THERE IS AN AREA OF LOW PRESSURE OVER THE WESTERN DAKOTA WITH A WEAK COLD FRONT EXTENDING THROUGH FAR NORTHWESTERN SOUTH DAKOTA AND NORTHERN WYOMING. AHEAD OF THE COLD FRONT A TROF/DRY LINE EXTENDS THROUGH SOUTH CENTRAL SOUTH DAKOTA INTO CENTRAL NEBRASKA. TEMPERATURES AT 2 PM RANGED FROM THE MID 80S OVER THE BLACK HILLS TO THE UPPER 90S IN SOUTH CENTRAL SOUTH DAKOTA. THE DRY LINE IN SOUTH CENTRAL SOUTH DAKOTA WILL BE THE FOCUS FOR STORMS THIS AFTERNOON INTO EARLY EVENING. AS THE DRY LINE SHIFTS EAST...ANY STORMS THAT FORM SHOULD QUICKLY PUSH OUT OF THE FORECAST AREA. THE WESTERN TROF WILL BEGIN TO LIFT NORTH TONIGHT AS THE COLD FRONT SLOWLY PUSHES THOUGH WESTERN SOUTH DAKOTA. SHEAR IS WEAK...VALUES OF 15KTS OR LESS AND CAPE IS MINIMAL. SHORT RANGE MODELS VARY WITH RESPECT TO POPS TONIGHT WITH RAP SHOWING DRY CONDITIONS...HRRR SHOWING SOME ISOLATED TO SCATTERED CONVECTION OVER NORTHEASTERN WYOMING AND NORTHWESTERN SOUTH DAKOTA AND SDSMT WRF INDICATING ISOLATED CONVECTION JUST NORTH OF THE HILLS. DUE TO THE MODEL DIFFERENCES...HAVE DECIDED TO KEEP LOW POPS IN THE FORECAST TONIGHT. TEMPERATURES OVERNIGHT WILL FALL INTO THE UPPER 50S BEHIND THE FRONT...WITH 60S TO LOWER 70S AHEAD OF THE FRONT IN SOUTH CENTRAL SOUTH DAKOTA. ON FRIDAY...BROAD RIDGE REMAINS ANCHORED ACROSS THE SOUTHERN PLAINS WITH WESTERLY UPPER FLOW ALOFT OVER THE NORTHERN PLAINS. SURFACE HIGH PRESSURE WILL MOVE EASTERLY ACROSS THE DAKOTAS EARLY IN THE DAY...WITH SOUTHERLY RETURN FLOW BY LATE AFTERNOON. A WEAK UPPER LEVEL SHORTWAVE WILL CROSS THE AREA DURING THE AFTERNOON AND EVENING...BRINGING A CHANCE FOR SOME SHOWERS AND THUNDERSTORMS. HIGH TEMPERATURES WILL BE SLIGHTLY COOLER THAN TODAY...IN THE 80S TO LOWER 90S. LOW TEMPERATURES FRIDAY NIGHT WILL BE IN THE MID 50S TO UPPER 60S. .LONG TERM...SATURDAY THROUGH THURSDAY ISSUED AT 227 PM MDT THU JUL 23 2015 ZONAL FLOW IS EXPECTED THROUGH THE END OF THE WEEKEND...WITH SUBTLE WAVES BRINGING DAILY ISOLATED STORMS TO DIFFERING PORTIONS OF THE AREA. UPPER TROUGH IS PROGGED TO DEVELOP ACROSS THE NW PAC COAST SUNDAY...THEN MOVE ACROSS THE NRN PLAINS/SRN CANADA MONDAY INTO TUESDAY. GOOD AGREEMENT BETWEEN GFS/ECM SHOWING STORMS DEVELOPING ALONG A COLD FRONT SOUTH OF THE SURFACE LOW. COOLER AND DRIER AIR WILL PUSH IN BEHIND THE FRONT AND REMAIN FOR THE REST OF THE LONG TERM. TEMPS WILL STILL BE NEAR TO SLIGHTLY BELOW AVERAGE. && .AVIATION...FOR THE 18Z TAFS THROUGH 18Z FRIDAY ISSUED AT 227 PM MDT THU JUL 23 2015 A FEW STORMS COULD INITIATE ALONG A COLD FRONT IN FAR NORTHWESTERN SD AND NORTHEASTERN WY THIS AFTERNOON. OTHERWISE, VFR CONDITIONS SHOULD PERSIST. WINDS WILL SHIFT FROM SOUTHWEST TO NORTHWEST AND BE GUSTY AT TIMES PRIOR TO SUNSET. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...MLS LONG TERM...13 AVIATION...WARD
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1249 PM CDT THU JUL 23 2015 .DISCUSSION... UPDATED FOR 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 1114 AM CDT THU JUL 23 2015/ UPDATE... STALLED FRONT REMAINS DRAPED ACROSS THE AREA FROM NEAR JONESBORO TO NEAR SAVANNAH. SHOWERS AND THUNDERSTORMS WILL REDEVELOP ALONG THE BOUNDARY THIS AFTERNOON. LATEST HRRR SHOWS MOST OF THE REDEVELOPMENT MAY OCCUR ALONG AND SOUTH OF A JONESBORO TO SAVANNAH LINE MAINLY DURING THE 3 PM-7 PM CDT TIME FRAME. MEANWHILE...ONGOING CONVECTION ACROSS NE ARKANSAS WILL PUSH EAST INTO THE MO BOOTHEEL AND NORTHWEST TENNESSEE DURING THE EARLY AFTERNOON HOURS WHILE CONVECTION NEAR THE TENNESSEE RIVER WILL PUSH EAST INTO MIDDLE TENNESSEE OVER THE NEXT 1-2 HOURS. WILL MAKE MINOR TWEAKS TO POPS...OTHERWISE REST OF FORECAST LOOKS GOOD. KRM DISCUSSION... /ISSUED 319 AM CDT THU JUL 23 2015/ CURRENTLY THE MIDSOUTH WAS CLOUDY TO MOSTLY CLOUDY. SCATTERED SHOWERS AND STORMS WERE DOTTED MAINLY NORTH OF INTERSTATE FORTY AS OF 3 AM. TEMPERATURES WERE VERY SIMILAR TO THIS TIME LAST NIGHT WITH WIDESPREAD LOW TO MID 70S. WINDS WERE GENERALLY CALM OVER THE EASTERN COUNTIES...WITH SOUTH WINDS OF 3 TO 8 KTS ALONG AND WEST OF THE MISSISSIPPI RIVER. FOR TODAY AND TONIGHT...NOT MUCH CHANGE TAKING PLACE IN THE ATMOSPHERE THE NEXT 24 HOURS...AND NOT MUCH CHANGE IN THE MODEL OUTPUTS SINCE YESTERDAY. THE STORM TRACK WILL CONTINUE TO RIDE ALONG A STALLED FRONTAL BOUNDARY WITH CURRENT WATER VAPOR IMAGERY AND RADAR SHOWING DISTURBANCES LINED UP BACK INTO THE CENTRAL PLAINS. THE UPPER RIDGE IS BUILDING OVER THE FRONT RANGE WHICH THE MODELS HAVE SHOWN...AND AS A RESULT 500MB WINDS HAVE VEERED NORTHWESTERLY ACROSS NORTHERN OKLAHOMA. ON THE SURFACE CURRENT WEAK FRONT HAS PUSHED A LITTLE NORTH DURING THE PAST 24 HOURS...NOW RIDING ALONG THE KY/TN BORDER. MUCH OF THE MIDSOUTH WILL SEE SCATTERED SHOWERS AND STORMS TODAY...WITH SOME HAVING THE POTENTIAL TO BE STRONG OR SEVERE. PLAN ON A MARGINAL RISK MENTION IN THIS MORNINGS HWO. ACTIVITY IS EXPECTED TO BEGIN DECREASING TONIGHT OVER THE NORTH AS THE DEVELOPING NORTHWEST GIVES THE FRONT A PUSH TO THE SOUTH. HAVE EXTENDED THE FFA OVER NORTHEAST ARKANSAS AND THE BOOTHEEL OF MISSOURI THROUGH EARLY THIS EVENING TO CAPTURE THIS PASSAGE. HIGHS WILL RANGE FROM THE UPPER 80S...TO LOW 90S. TOMORROW...THE ENTIRE REGION WILL BE BACK IN NORTHWEST FLOW ALOFT WITH THE WEAK FRONT STALLING ACROSS THE FAR SOUTHWEST COUNTIES. IT APPEARS THAT JUST ENOUGH STABLE AIR FROM THE OHIO VALLEY MAY WORKS ITS WAY INTO THE FAR NORTHEAST COUNTIES...TAKING RAIN CHANCES TO BELOW 15 PERCENT. DEWPOINTS IN THIS REGION WILL ALSO FALL INTO 60S. ELSEWHERE THE HUMIDITY WILL STILL REMAIN HIGH FRO ISOLATED CONVECTION...AND THE SOUTHWEST COUNTIES MAY FLIRT WITH HEAT ADVISORY CONDITIONS. SATURDAY THROUGH MONDAY...THE RETURN TO HIGHER HEAT IS STILL WELL ON TRACK...WITH MINIMAL RAIN CHANCES. HIGH PRESSURE THROUGHOUT THE COLUMN WILL YIELD LIGHT WINDS AND STRONG SUBSIDENCE. WIDESPREAD MID AND UPPER 90 TEMPERATURES ARE ANTICIPATED WITH HEAT ADVISORIES LIKELY. TUESDAY AND WEDNESDAY...A STRONG SHORTWAVE WILL ENTER THE NORTHERN ROCKIES NEXT WEEK BEFORE TRACKING INTO THE UPPER MIDWEST. THE RIDGE WILL FLATTEN SOME OVER THE MIDSOUTH...BUT MODELS ARE NOT REALLY SIGNALING A CHANGE IN TEMPERATURES. AN ISOLATED SHOWER DURING THE PERIOD MAY COOL A FEW OFF OTHERWISE CONFIDENCE IS HIGH THAT HEAT INDICES ABOVE 105F WILL CONTINUE. JAB && .AVIATION... 18Z TAF CYCLE A WEAK FRONT REMAINS ACROSS THE AREA. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP INVOF THIS BOUNDARY INTO THIS EVENING. IN THE SHORT TERM...KMEM STANDS THE BEST CHANCE OF TSRAS ON STATION OVER THE NEXT 1-2 HOURS. ELSW WILL CONTINUE A MENTION OF VCTS THROUGH ABOUT 24/01Z AREAWIDE. OUTSIDE OF SHRAS/TSRAS EXPECT VFR CONDS. AREAS OF FOG DEVELOPING AFTER 24/06Z WITH MVFR CONDITIONS POSSIBLE AT KMEM...KJBR AND KTUP...IFR CONDITIONS POSSIBLE AT KMKL. WINDS WEST THIS AFTERNOON 6-8 KTS AND LIGHT TONIGHT INTO FRIDAY MORNING. SJM && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH-ST. FRANCIS. MO...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN- PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1114 AM CDT THU JUL 23 2015 .UPDATE... STALLED FRONT REMAINS DRAPED ACROSS THE AREA FROM NEAR JONESBORO TO NEAR SAVANNAH. SHOWERS AND THUNDERSTORMS WILL REDEVELOP ALONG THE BOUNDARY THIS AFTERNOON. LATEST HRRR SHOWS MOST OF THE REDEVELOPMENT MAY OCCUR ALONG AND SOUTH OF A JONESBORO TO SAVANNAH LINE MAINLY DURING THE 3 PM-7 PM CDT TIME FRAME. MEANWHILE...ONGOING CONVECTION ACROSS NE ARKANSAS WILL PUSH EAST INTO THE MO BOOTHEEL AND NORTHWEST TENNESSEE DURING THE EARLY AFTERNOON HOURS WHILE CONVECTION NEAR THE TENNESSEE RIVER WILL PUSH EAST INTO MIDDLE TENNESSEE OVER THE NEXT 1-2 HOURS. WILL MAKE MINOR TWEAKS TO POPS...OTHERWISE REST OF FORECAST LOOKS GOOD. KRM && .DISCUSSION... /ISSUED 319 AM CDT THU JUL 23 2015/ CURRENTLY THE MIDSOUTH WAS CLOUDY TO MOSTLY CLOUDY. SCATTERED SHOWERS AND STORMS WERE DOTTED MAINLY NORTH OF INTERSTATE FORTY AS OF 3 AM. TEMPERATURES WERE VERY SIMILAR TO THIS TIME LAST NIGHT WITH WIDESPREAD LOW TO MID 70S. WINDS WERE GENERALLY CALM OVER THE EASTERN COUNTIES...WITH SOUTH WINDS OF 3 TO 8 KTS ALONG AND WEST OF THE MISSISSIPPI RIVER. FOR TODAY AND TONIGHT...NOT MUCH CHANGE TAKING PLACE IN THE ATMOSPHERE THE NEXT 24 HOURS...AND NOT MUCH CHANGE IN THE MODEL OUTPUTS SINCE YESTERDAY. THE STORM TRACK WILL CONTINUE TO RIDE ALONG A STALLED FRONTAL BOUNDARY WITH CURRENT WATER VAPOR IMAGERY AND RADAR SHOWING DISTURBANCES LINED UP BACK INTO THE CENTRAL PLAINS. THE UPPER RIDGE IS BUILDING OVER THE FRONT RANGE WHICH THE MODELS HAVE SHOWN...AND AS A RESULT 500MB WINDS HAVE VEERED NORTHWESTERLY ACROSS NORTHERN OKLAHOMA. ON THE SURFACE CURRENT WEAK FRONT HAS PUSHED A LITTLE NORTH DURING THE PAST 24 HOURS...NOW RIDING ALONG THE KY/TN BORDER. MUCH OF THE MIDSOUTH WILL SEE SCATTERED SHOWERS AND STORMS TODAY...WITH SOME HAVING THE POTENTIAL TO BE STRONG OR SEVERE. PLAN ON A MARGINAL RISK MENTION IN THIS MORNINGS HWO. ACTIVITY IS EXPECTED TO BEGIN DECREASING TONIGHT OVER THE NORTH AS THE DEVELOPING NORTHWEST GIVES THE FRONT A PUSH TO THE SOUTH. HAVE EXTENDED THE FFA OVER NORTHEAST ARKANSAS AND THE BOOTHEEL OF MISSOURI THROUGH EARLY THIS EVENING TO CAPTURE THIS PASSAGE. HIGHS WILL RANGE FROM THE UPPER 80S...TO LOW 90S. TOMORROW...THE ENTIRE REGION WILL BE BACK IN NORTHWEST FLOW ALOFT WITH THE WEAK FRONT STALLING ACROSS THE FAR SOUTHWEST COUNTIES. IT APPEARS THAT JUST ENOUGH STABLE AIR FROM THE OHIO VALLEY MAY WORKS ITS WAY INTO THE FAR NORTHEAST COUNTIES...TAKING RAIN CHANCES TO BELOW 15 PERCENT. DEWPOINTS IN THIS REGION WILL ALSO FALL INTO 60S. ELSEWHERE THE HUMIDITY WILL STILL REMAIN HIGH FRO ISOLATED CONVECTION...AND THE SOUTHWEST COUNTIES MAY FLIRT WITH HEAT ADVISORY CONDITIONS. SATURDAY THROUGH MONDAY...THE RETURN TO HIGHER HEAT IS STILL WELL ON TRACK...WITH MINIMAL RAIN CHANCES. HIGH PRESSURE THROUGHOUT THE COLUMN WILL YIELD LIGHT WINDS AND STRONG SUBSIDENCE. WIDESPREAD MID AND UPPER 90 TEMPERATURES ARE ANTICIPATED WITH HEAT ADVISORIES LIKELY. TUESDAY AND WEDNESDAY...A STRONG SHORTWAVE WILL ENTER THE NORTHERN ROCKIES NEXT WEEK BEFORE TRACKING INTO THE UPPER MIDWEST. THE RIDGE WILL FLATTEN SOME OVER THE MIDSOUTH...BUT MODELS ARE NOT REALLY SIGNALING A CHANGE IN TEMPERATURES. AN ISOLATED SHOWER DURING THE PERIOD MAY COOL A FEW OFF OTHERWISE CONFIDENCE IS HIGH THAT HEAT INDICES ABOVE 105F WILL CONTINUE. JAB && .AVIATION... 12Z TAF CYCLE (23/12Z-24/12Z) SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS THE MIDSOUTH TODAY INTO THIS EVENING AS WEAK UPPER LEVEL DISTURBANCES INTERACT WITH A MOIST AND UNSTABLE ATMOSPHERE. TIMING AND PLACEMENT OF THE CONVECTION IS DIFFICULT BEYOND A FEW HOURS. VFR CONDITIONS WILL PREVAIL OUTSIDE SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE PERIOD. AREAS OF FOG DEVELOPING AFTER 24/06Z WITH MVFR CONDITIONS POSSIBLE AT KMEM AND KJBR...IFR CONDITIONS POSSIBLE AT KMKL. WINDS BECOMING WESTERLY TODAY 8-9 KTS. WINDS LIGHT TONIGHT. JCL && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH-ST. FRANCIS. MO...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN- PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1202 PM CDT Thu Jul 23 2015 .AVIATION... /18Z TAFS/ All terminals should have VFR conditions through the next 24 hours. Stratus that degraded the southern terminals to MVFR this morning should remain south of the southern terminals tomorrow morning. Winds will remain southerly at 5 to 15 knots at all terminals. && .PREV DISCUSSION... /ISSUED 612 AM CDT Thu Jul 23 2015/ AVIATION... /12Z TAFS/ Patchy MVFR stratus will persist across the northwest Hill Country this morning, potentially affecting the KJCT terminal. This stratus will erode by mid-morning with a high based cu field anticipated this afternoon. A few showers will occur to the west and northwest of KSWW, but will amount to little. Otherwise, dry weather is expected across the area through the next 24 hours with south winds around 10 kts. 25 PREV DISCUSSION... /ISSUED 324 AM CDT Thu Jul 23 2015/ SHORT TERM... (Today and tonight) The development of mid-level cumuliform clouds from Midland, to Haskell, to Albany over the past few hours implies a region of ascent moving across West TX. The TTU WRF and HRRR are hinting at the potential for a few showers early this morning, but anything that develops should remain west of Sweetwater. Farther south, low stratus over the Hill County is increasing in coverage and advecting north. This cloud cover will likely affect the southeast portion of the CWA through around 9 AM. Otherwise, expect hot and dry conditions across West Central TX with afternoon highs in the upper 90s to around 101 degrees. Skies will be mostly clear tonight, although a few low clouds will be possible along the I-10 corridor after 3 AM. Winds will remain under 10 mph with overnight lows in the mid 70s. Johnson LONG TERM... (Friday through Wednesday) No relief in sight from the heat in the extended forecast. Temperatures may even get a degree or two hotter this weekend as the center of upper level high pressure moves back over West Texas, with highs in the 99 to 102 range. && .PRELIMINARY POINT TEMPS/POPS... Abilene 77 98 77 99 77 / 0 0 5 5 5 San Angelo 76 101 76 102 76 / 0 0 5 5 5 Junction 75 97 75 99 75 / 0 0 5 5 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/99/99
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
143 PM EDT THU JUL 23 2015 .SYNOPSIS... A STALLED FRONT WILL REMAIN SOUTH OF THE REGION FRIDAY. WEAK WAVES OF LOW PRESSURE WILL TRACK ALONG THE FRONT TODAY AND TONIGHT...WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST ON FRIDAY. HIGH PRESSURE WILL STRENGTHEN FRIDAY THROUGH THE WEEKEND OVER THE MID ATLANTIC REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1255 PM EDT THURSDAY... THE FIRST WAVE OF SHOWERS HAS EXITED THE SOUTHEAST PORTION OF THE FORECAST AREA. THE LEADING EDGE OF THE NEXT REGION OF SHOWER ACTIVITY WILL ENTER THE SOUTHWEST PART OF THE REGION AROUND 400 PM. HOWEVER...ISOLATED CONVECTION IS POSSIBLE AHEAD OF THIS MAIN AREA ACROSS THE SOUTHERN THIRD OF THE REGION. THE BEST CHANCE OF ANY THUNDERSTORMS WILL BE LATER THIS AFTERNOON IN AREAS NEAR AND SOUTH OF THE NC/VA STATE LINE. HAVE MADE SOME MINOR ADJUSTMENTS DOWNWARD OF THE FORECAST HIGH TEMPERATURES TODAY...MAINLY IN AREAS ALONG AND NEAR THE NC/VA BORDER EAST OF I-77. RAIN FROM EARLIER TODAY AND RESIDUAL CLOUD COVER IS PREVENTING AS QUICK OF A CLIMB OF TEMPERATURES THAN EARLIER FORECAST. AS OF 955 AM EDT THURSDAY... MORNING UPDATE WILL REFLECT A MORE DISTINCT SEPARATION IN PRECIPITATION COVERAGE ACROSS THE REGION. CURRENTLY RAIN SHOWERS ARE EXITING THE SOUTHEAST PART OF THE REGION TO THE EAST...WITH NO OTHER PRECIPITATION IN THE AREA. THEREFORE..HAVE REMOVED THE PRECIPITATION CHANCES IN THE SOUTHWEST PARTS OF THE AREA UNTIL IT HAS A CHANCE TO MOVE INTO REGION THIS AFTERNOON FROM THE WEST. HAVE ALSO ADJUSTED HOURLY TEMPERATURE...DEW POINT AND SKY COVER GRIDS THROUGH THE NEXT FEW HOURS BASED UPON THE CURRENT OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY AFTERNOON. AS OF 650 AM EDT THURSDAY... SHORT WAVE WAS OVER THE MID MISSISSIPPI VALLEY EARLY THIS MORNING ND WILL TRACK INTO THE CAROLINA BY FRIDAY MORNING. THE ASSOCIATED PRECIPITATION WAS OVER TENNESSEE AND KENTUCKY AT 08Z. MODELS BRING THE PRECIPITATION EAST ALONG THE 850 MB FRONT. LITTLE MOVEMENT OF THE SURFACE FRONT IS EXPECTED TODAY AND INTO THIS EVENING. SURFACE WINDS WILL BE LIGHT AND VARIABLE UNTIL THE SHORT WAVE MOVES TO THE EAST...THEN PREVAILING FLOW WILL BE OUT OF THE NORTHEAST. UNTIL THEN COUNTY WARNING AREA IS IN BETWEEN THE FRONT OVER THE CAROLINAS AND HIGH PRESSURE OVER THE OHIO VALLEY. HAVE RAISED PROBABILITY OF PRECIPITATION TO ACCOUNT BASED ON RADAR TRENDS. HRRR AND LOCAL WRF BRING NEXT BATCH OF PRECIPITATION IN AFTER 15Z/10AM. MODELS SIMILAR WITH NORTHERN EXTENT OF THE BEST PROBABILITY OF PRECIPITATION. HIGHER CONVECTIVE AVAILABLE POTENTIAL ENERGY AND LOWER LIFTED INDEX VALUES WILL BE ALONG AND SOUTH OF ROUTE 460. WILL KEEP HIGHEST PROBABILITY OF PRECIPITATION IN THE SOUTHERN HALF OF THE FORECAST AREA THIS AFTERNOON AND EVENING. THIS ALSO LINES UP WITH PRECIPITABLE WATER VALUES OF 1.5 TO 2.0 INCHES. THIS DEEPER MOISTURE BEGINS TO EXIT SOUTHEAST OUT OF THE FORECAST AREA LATE TONIGHT. HOWEVER...NORTHEAST WINDS AND LOW LEVEL MOISTURE WILL KEEP LOW CLOUDS AND FOG IN THE REGION...ESPECIALLY IN THE EASTERN UPSLOPE AREA OF THE APPALACHIANS. DRIER AIR COMING IN THE NORTH ERN COUNTY WARNING AREA AND LESS CLOUD COVER COMPARED TO MORE CLOUDS IN THE CENTRAL AND SOUTHERN COUNTY WARNING AREA WILL RESULT IN A LARGE SPREAD OF MINIMUM TEMPERATURES. DO NOT EXPECT AS MUCH OF A DROP I N HE SOUTH...WHILE NORTHERN COUNTIES MAY LOWER INTO THE 50S. LOCAL WRF GUIDANCE LOOKED REASONABLE FOR LOWS TONIGHT. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM EDT THURSDAY... LOW PRESSURE JUST OFF THE NORTH CAROLINA COAST FRIDAY MORNING WILL MOVE EAST INTO THE ATLANTIC OCEAN THROUGH THE PERIOD. MEANWHILE HIGH PRESSURE TO OUR NORTHWEST WILL BUILD SOUTH ON FRIDAY AND MOVE ACROSS THE MID ATLANTIC REGION INTO SATURDAY NIGHT. THE COMBINATION OF HEATING...DESTABILIZATION...MOISTURE SFC FLOW OVER HIGHER TERRAIN SUPPORTS THE MENTION OF ISOLATED TO WIDELY SCATTERED CONVECTION CROSS THE SOUTHWEST. HIGH TEMPERATURES FRIDAY WILL CLIMB TO NEAR 80 DEGREES IN THE WEST TO THE UPPER 80S IN THE EAST. TAPER OFF ISOLATED SHOWERS FRIDAY NIGHT BY MIDNIGHT AND ADDED SOME PATCHY FOG FRIDAY NIGHT INTO SATURDAY MORNING. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 50S IN THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT. EXPECT A NICE SATURDAY WITH ONLY AN ISOLATED CHANCE OF SHOWERS ACROSS THE MOUNTAINS. HIGH TEMPERATURES SATURDAY WILL MODERATE INTO THE LOWER 80S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. YOU CAN ANTICIPATE DRY WEATHER FOR SATURDAY NIGHT WITH LOW TEMPERATURES FROM THE LOWER 60S IN THE WEST TO THE MID 60S IN THE EAST. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 240 PM EDT WEDNESDAY... GOING TO UPPER RIDGE START TO LEAN WEST TO EAST ACROSS THE SOUTHERN PLAINS TO THE APPALACHIANS THIS PERIOD WITH GRADUALLY BUILDING HEIGHTS. OUR REGION WILL STAY IN A NW FLOW ALOFT THIS SUNDAY THEN MORE NORTHERLY BY TUESDAY-WEDNESDAY. MEAN SOLUTION OF MODELS SUGGEST NOT BIG THREAT OF CONVECTION THIS PERIOD...THOUGH BEST SHOT WILL BE PERHAPS MONDAY AS SHORTWAVE MOVES FROM OHIO TO THE MID ATLANTIC SETTING UP SOME HEIGHT FALLS OVER VIRGINIA...AND WEAK FRONTAL BOUNDARY PASSING ACROSS. AT THIS TIME WILL MAINTAIN IN THE CHANCE RANGE FOR POPS. WILL START TO SEE HUMIDITY ELEVATE ONCE AGAIN WITH BUILDING HEIGHTS AND LIGHT SOUTHEAST TO SOUTHWEST WINDS IN THE SFC TO LOW LVLS. HIGHS AND LOWS WILL BE CLOSE TO NORMAL FOR LATE JULY WITH MID 60S MOUNTAINS TO AROUND 70 PIEDMONT FOR LOWS...AND HIGHS IN THE LOWER TO MID 80S MOUNTAINS TO AROUND 90 PIEDMONT...INCLUDING ROANOKE CITY. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 135 PM EDT THURSDAY... POCKETS OF MVFR CIGS EXIST OVER PORTIONS OF NORTHWEST NORTH CAROLINA AND NEIGHBORING SECTIONS OF SOUTHWEST VIRGINIA...AS WELL AS...SOME ISOLATED SHOWERS. ELSEWHERE ACROSS THE REGION...VFR SKIES PREVAILED WITH NO PRECIPITATION. THIS SCENARIO WILL BE CHANGING. AN UPPER LEVEL DISTURBANCE IS CURRENTLY PROGRESSING EASTWARD THROUGH KY/TN ALONG A STALLED FRONTAL BOUNDARY. TRAJECTORIES OF THIS SYSTEM TAKE THE BULK OF THE ASSOCIATED PRECIPITATION ACROSS THE SOUTHWEST PORTION OF THE FORECAST AREA THIS AFTERNOON INTO THE EVENING HOURS. ISOLATED COVERAGE REACHES NORTH CLOSE TO A KBLF-KBCB-KROA LINE BY LATE THIS AFTERNOON. ISOLATED TO SCATTERED THUNDERSTORMS WILL ALSO BE POSSIBLE...ESPECIALLY ACROSS THE SOUTHWEST AND SOUTHERN PARTS OF THE REGION. THIS SYSTEM WILL BE ALONG THE COAST LATE THIS EVENING...AND ALLOW FOR OUR LOW LEVEL WINDS TO TAKE ON MORE OF A NORTHEAST TO EAST TRAJECTORY. THE REGION WILL END UP WITH A NOSE OF MOISTURE WITH ATLANTIC ORIGINS OVERSPREAD BY MUCH DRIER AIR ALOFT. THIS LOW LEVEL MOISTURE INVERSION WILL YIELD IFR/MVFR CIGS/VSBYS OVER MUCH OF THE REGION DURING THE OVERNIGHT HOURS...ESPECIALLY IN AREAS ALONG AND EAST OF THE CREST OF THE BLUE RIDGE. THE INVERSION IS EXPECTED TO BREAK BY THE MID TO LATE MORNING ON FRIDAY AND YIELD VFR CONDITIONS TO THE ENTIRE REGION. EXTENDED AVIATION FORECAST... FRIDAY THROUGH EARLY NEXT WEEK...HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE ACROSS THE REGION. MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT FOR THE POTENTIAL OF LATE NIGHT AND EARLY MORNING MOUNTAIN VALLEY FOG. ISOLATED SHOWERS AND STORMS CANNOT BE RULED OUT...BUT WILL CERTAINLY BE THE EXCEPTION TO THE RULE A WEAK BACKDOOR FRONT MAY ENTER THE REGION LATE SUNDAY NIGHT INTO MONDAY. THIS WOULD EXPAND SHOWER AND THUNDERSTORMS COVERAGE MONDAY INTO TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...KK LONG TERM...WP AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
101 PM EDT THU JUL 23 2015 .SYNOPSIS... A STALLED FRONT WILL REMAIN SOUTH OF THE REGION FRIDAY. WEAK WAVES OF LOW PRESSURE WILL TRACK ALONG THE FRONT TODAY AND TONIGHT...WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST ON FRIDAY. HIGH PRESSURE WILL STRENGTHEN FRIDAY THROUGH THE WEEKEND OVER THE MID ATLANTIC REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1255 PM EDT THURSDAY... THE FIRST WAVE OF SHOWERS HAS EXITED THE SOUTHEAST PORTION OF THE FORECAST AREA. THE LEADING EDGE OF THE NEXT REGION OF SHOWER ACTIVITY WILL ENTER THE SOUTHWEST PART OF THE REGION AROUND 400 PM. HOWEVER...ISOLATED CONVECTION IS POSSIBLE AHEAD OF THIS MAIN AREA ACROSS THE SOUTHERN THIRD OF THE REGION. THE BEST CHANCE OF ANY THUNDERSTORMS WILL BE LATER THIS AFTERNOON IN AREAS NEAR AND SOUTH OF THE NC/VA STATE LINE. HAVE MADE SOME MINOR ADJUSTMENTS DOWNWARD OF THE FORECAST HIGH TEMPERATURES TODAY...MAINLY IN AREAS ALONG AND NEAR THE NC/VA BORDER EAST OF I-77. RAIN FROM EARLIER TODAY AND RESIDUAL CLOUD COVER IS PREVENTING AS QUICK OF A CLIMB OF TEMPERATURES THAN EARLIER FORECAST. AS OF 955 AM EDT THURSDAY... MORNING UPDATE WILL REFLECT A MORE DISTINCT SEPARATION IN PRECIPITATION COVERAGE ACROSS THE REGION. CURRENTLY RAIN SHOWERS ARE EXITING THE SOUTHEAST PART OF THE REGION TO THE EAST...WITH NO OTHER PRECIPITATION IN THE AREA. THEREFORE..HAVE REMOVED THE PRECIPITATION CHANCES IN THE SOUTHWEST PARTS OF THE AREA UNTIL IT HAS A CHANCE TO MOVE INTO REGION THIS AFTERNOON FROM THE WEST. HAVE ALSO ADJUSTED HOURLY TEMPERATURE...DEW POINT AND SKY COVER GRIDS THROUGH THE NEXT FEW HOURS BASED UPON THE CURRENT OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY AFTERNOON. AS OF 650 AM EDT THURSDAY... SHORT WAVE WAS OVER THE MID MISSISSIPPI VALLEY EARLY THIS MORNING ND WILL TRACK INTO THE CAROLINA BY FRIDAY MORNING. THE ASSOCIATED PRECIPITATION WAS OVER TENNESSEE AND KENTUCKY AT 08Z. MODELS BRING THE PRECIPITATION EAST ALONG THE 850 MB FRONT. LITTLE MOVEMENT OF THE SURFACE FRONT IS EXPECTED TODAY AND INTO THIS EVENING. SURFACE WINDS WILL BE LIGHT AND VARIABLE UNTIL THE SHORT WAVE MOVES TO THE EAST...THEN PREVAILING FLOW WILL BE OUT OF THE NORTHEAST. UNTIL THEN COUNTY WARNING AREA IS IN BETWEEN THE FRONT OVER THE CAROLINAS AND HIGH PRESSURE OVER THE OHIO VALLEY. HAVE RAISED PROBABILITY OF PRECIPITATION TO ACCOUNT BASED ON RADAR TRENDS. HRRR AND LOCAL WRF BRING NEXT BATCH OF PRECIPITATION IN AFTER 15Z/10AM. MODELS SIMILAR WITH NORTHERN EXTENT OF THE BEST PROBABILITY OF PRECIPITATION. HIGHER CONVECTIVE AVAILABLE POTENTIAL ENERGY AND LOWER LIFTED INDEX VALUES WILL BE ALONG AND SOUTH OF ROUTE 460. WILL KEEP HIGHEST PROBABILITY OF PRECIPITATION IN THE SOUTHERN HALF OF THE FORECAST AREA THIS AFTERNOON AND EVENING. THIS ALSO LINES UP WITH PRECIPITABLE WATER VALUES OF 1.5 TO 2.0 INCHES. THIS DEEPER MOISTURE BEGINS TO EXIT SOUTHEAST OUT OF THE FORECAST AREA LATE TONIGHT. HOWEVER...NORTHEAST WINDS AND LOW LEVEL MOISTURE WILL KEEP LOW CLOUDS AND FOG IN THE REGION...ESPECIALLY IN THE EASTERN UPSLOPE AREA OF THE APPALACHIANS. DRIER AIR COMING IN THE NORTH ERN COUNTY WARNING AREA AND LESS CLOUD COVER COMPARED TO MORE CLOUDS IN THE CENTRAL AND SOUTHERN COUNTY WARNING AREA WILL RESULT IN A LARGE SPREAD OF MINIMUM TEMPERATURES. DO NOT EXPECT AS MUCH OF A DROP I N HE SOUTH...WHILE NORTHERN COUNTIES MAY LOWER INTO THE 50S. LOCAL WRF GUIDANCE LOOKED REASONABLE FOR LOWS TONIGHT. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM EDT THURSDAY... LOW PRESSURE JUST OFF THE NORTH CAROLINA COAST FRIDAY MORNING WILL MOVE EAST INTO THE ATLANTIC OCEAN THROUGH THE PERIOD. MEANWHILE HIGH PRESSURE TO OUR NORTHWEST WILL BUILD SOUTH ON FRIDAY AND MOVE ACROSS THE MID ATLANTIC REGION INTO SATURDAY NIGHT. THE COMBINATION OF HEATING...DESTABILIZATION...MOISTURE SFC FLOW OVER HIGHER TERRAIN SUPPORTS THE MENTION OF ISOLATED TO WIDELY SCATTERED CONVECTION CROSS THE SOUTHWEST. HIGH TEMPERATURES FRIDAY WILL CLIMB TO NEAR 80 DEGREES IN THE WEST TO THE UPPER 80S IN THE EAST. TAPER OFF ISOLATED SHOWERS FRIDAY NIGHT BY MIDNIGHT AND ADDED SOME PATCHY FOG FRIDAY NIGHT INTO SATURDAY MORNING. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 50S IN THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT. EXPECT A NICE SATURDAY WITH ONLY AN ISOLATED CHANCE OF SHOWERS ACROSS THE MOUNTAINS. HIGH TEMPERATURES SATURDAY WILL MODERATE INTO THE LOWER 80S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. YOU CAN ANTICIPATE DRY WEATHER FOR SATURDAY NIGHT WITH LOW TEMPERATURES FROM THE LOWER 60S IN THE WEST TO THE MID 60S IN THE EAST. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 240 PM EDT WEDNESDAY... GOING TO UPPER RIDGE START TO LEAN WEST TO EAST ACROSS THE SOUTHERN PLAINS TO THE APPALACHIANS THIS PERIOD WITH GRADUALLY BUILDING HEIGHTS. OUR REGION WILL STAY IN A NW FLOW ALOFT THIS SUNDAY THEN MORE NORTHERLY BY TUESDAY-WEDNESDAY. MEAN SOLUTION OF MODELS SUGGEST NOT BIG THREAT OF CONVECTION THIS PERIOD...THOUGH BEST SHOT WILL BE PERHAPS MONDAY AS SHORTWAVE MOVES FROM OHIO TO THE MID ATLANTIC SETTING UP SOME HEIGHT FALLS OVER VIRGINIA...AND WEAK FRONTAL BOUNDARY PASSING ACROSS. AT THIS TIME WILL MAINTAIN IN THE CHANCE RANGE FOR POPS. WILL START TO SEE HUMIDITY ELEVATE ONCE AGAIN WITH BUILDING HEIGHTS AND LIGHT SOUTHEAST TO SOUTHWEST WINDS IN THE SFC TO LOW LVLS. HIGHS AND LOWS WILL BE CLOSE TO NORMAL FOR LATE JULY WITH MID 60S MOUNTAINS TO AROUND 70 PIEDMONT FOR LOWS...AND HIGHS IN THE LOWER TO MID 80S MOUNTAINS TO AROUND 90 PIEDMONT...INCLUDING ROANOKE CITY. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 735 AM EDT THURSDAY... BASED ON THE LATEST RADAR TRENDS AND WATER VAPOR SATELLITE LOOP...SCATTERED SHOWERS WILL MOVE ACROSS NORTHERN NORTH CAROLINA AND EXTREME SOUTHERN VIRGINIA THIS MORNING. HOWEVER...VISIBILITIES WILL REMAIN VFR....EVEN WITH THE RAIN...AT KLYH AND KDAN. A SHORT WAVE OVER MISSOURI EARLY THIS MORNING WILL TRACK INTO THE CAROLINAS BY FRIDAY MORNING. THE ASSOCIATED SHOWERS AND THUNDERSTORMS OVER KENTUCKY AND TENNESSEE WILL MOVE EAST BRINGING MORE PRECIPITATION TO SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA BY EARLY THIS AFTERNOON. MODELS IN DECENT AGREEMENT THAT NORTHERN EDGE OF THE PRECIPITATION CHANCE WILL STAY JUST SOUTH OF KBLF/KROA/KLYH. KDAN HAS THE BEST CHANCE OF SHOWERS TODAY...WHICH MAY RESULT IN BRIEF MVFR CONDITIONS. OTHERWISE CEILINGS AND VISIBILITIES WILL BE VFR. THE FRONT AND DEEP MOISTURE PUSH SOUTH OUT OF THE AREA TONIGHT. SURFACE AND LOW LEVEL WINDS BECOME EAST TO NORTHEAST TONIGHT. THIS WILL BRING MOISTURE UP AGAINST THE EAST SLOPES OF THE APPALACHIANS. HAVE ADDED MVFR FOG AND CLOUDS IN FOR KROA/KDAN AND KLYH AFTER MIDNIGHT. MEDIUM CONFIDENCE ON THESE CEILING HEIGHTS...MAY END UP BEING MUCH LOWER. EXTENDED AVIATION FORECAST... FRIDAY THROUGH EARLY NEXT WEEK...HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE ACROSS THE REGION. MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT FOR THE POTENTIAL OF LATE NIGHT AND EARLY MORNING MOUNTAIN VALLEY FOG. ISOLATED SHOWERS AND STORMS CANNOT BE RULED OUT...ESPECIALLY OVER THE MOUNTAINS ON SUNDAY AFTERNOON. A WEAK BACKDOOR FRONT MAY ENTER THE REGION LATE SUNDAY NIGHT INTO MONDAY. THIS WOULD EXPAND SHOWER AND THUNDERSTORMS COVERAGE MONDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...KK LONG TERM...WP AVIATION...AMS/JH