Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/02/12


AREA FORECAST DISCUSSION
NWS DENVER CO
743 PM MDT WED AUG 1 2012 .UPDATE...SHOWERS AND THUNDERSTORMS CONTINUE TO MARCH EAST ACROSS NORTHEAST COLORADO AND ALSO ACROSS THE MOUNTAINS OF CENTRAL COLORADO. LOWERED POPS FOR THIS EVENING ALONG PARTS OF THE FRONT RANGE TO ISOLATED. STILL THINK A FEW SHOWERS WILL MAKE IT ACROSS THE MOUNTAINS...ESPECIALLY SOUTH WHERE THERE IS MORE ACTIVITY. OTHER CHANGES MADE WERE TO ADJUST POPS...WIND...AND SKY COVER TO REFLECT CURRENT CONDITIONS. && .AVIATION...WIND DIRECTION WILL CONTINUE TO VARIABLE THROUGH 06Z AS OUTFLOW BOUNDARIES FROM CONVECTION PUSH THROUGH THE DENVER AIRPORTS. AFTER 06Z...WINDS WILL BECOME NORMAL DRAINAGE DIRECTION. ANOTHER ROUND OF CONVECTION IS EXPECTED THURSDAY AFTERNOON WITH A LITTLE LESS COVERAGE. && .PREV DISCUSSION... /ISSUED 316 PM MDT WED AUG 1 2012/ SHORT TERM...THE UPPER LEVEL RIDGE OVER THE TEXAS PANHANDLE WILL SHIFT FURTHER SOUTH TONIGHT ALLOWING FOR A WEAK WESTERLY FLOW ALOFT OVER THE REGION ON THURSDAY. THE 16Z HRRR REPRESENTS THE ONGOING CONVECTION FAIRLY WELL AT THIS TIME. IT ALLOWS FOR THE MAIN WINDOW OF TSTMS TO MOVE ACROSS THE FOOTHILLS AND URBAN CORRIDOR THROUGH 00Z AND ACROSS THE NORTHEASTERN PLAINS THROUGH 04Z. THE AMS IS STILL QUITE MOIST WITH PW VALUES AROUND ONE INCH. WET MICROBURSTS WITH BRIEF HEAVY RAIN...0.5 TO 1 INCH IN 30 MINUTES AND WIND GUSTS TO 40 KTS. WILL FOLLOW THE TIMING OF THE HRRR SOLUTION IN THIS EVENINGS PACKAGE. THE AMS IS PROGGED TO STABILIZE FAIRLY FAST AFTER 04Z. ON THURSDAY...SUBTROPICAL MOISTURE WILL CONTINUE OVER THE CWFA...WITH SOME SLIGHT DECREASE IN PW VALUES ADVERTISED WITH THE LOWER LEVELS SLIGHTLY DRIER BELOW 600 MB. STILL ENUF HOWEVER FOR THE THREAT OF BRIEF HEAVY RAIN SHOWERS. FCST CAPES ON THE SOUNDINGS IN THE 400-700 J/KG RANGE. WITH THAT IN MIND...THE SEVERE THREAT WILL BE LOW. LONG TERM...NO BIG CHANGES IN FORECAST REASONING THIS TIME AROUND. IT STILL LOOKS LIKE INCREASING WESTERLY FLOW ACROSS THE NORTHERN HALF OF THE U.S. WILL BE GOOD ENOUGH TO CUT OFF THE FLOW OF MONSOONAL MOISTURE FROM THE DESERT SOUTHWEST. IT SEEMS LIKE FRIDAY IS GOING TO BE THE FIRST DRY DAY OF THE SHORT BREAK FROM THE MONSOON. WARM TEMPERATURES WILL CONTINUE THROUGH FRIDAY AS NO CHANGE IN THE LOW LEVEL AIRMASS IS EXPECTED UNTIL SATURDAY MORNING. THE MOSTLY SUNNY DAY ON FRIDAY WILL ALLOW TEMPERATURES TO CLIMB BACK INTO THE MID 90S AS THE WEEK DRAWS TO A CLOSE. SATURDAY MORNING WILL BRING A NICE INTRUSION OF COOLER AIR ACROSS THE FORECAST AREA AS AN UPPER DISTURBANCE CROSSES THE STATE. LOW TEMPERATURES SATURDAY MORNING MAY DROP INTO THE MID 50S ACROSS THE PLAINS. THE HUMIDITY LEVELS ASSOCIATED WITH THIS COLD FRONT LOOK QUESTIONABLE AT THIS POINT...SO I HESITATE TO MENTION TOO MUCH PRECIPITATION IN THE FOOTHILLS SATURDAY MORNING. SOME AREAS MAY SEE SOME LIGHT RAIN OR DRIZZLE. BY AFTERNOON...THE AIRMASS BEGINS DRYING OUT WHILE MODEL SOUNDINGS SHOW THAT A MID LEVEL CAP WILL BE IN PLACE TO HINDER THE DEVELOPMENT OF ANY SHOWERS. THE ONLY EXCEPTION TO THIS MIGHT BE THE CENTRAL MOUNTAINS WHERE THE HEATING OVER THE HIGHER TERRAIN MAY BE ENOUGH TO OVERCOME THE MID-LEVEL INVERSION. HIGHS ON SATURDAY WILL PROBABLY REMAIN BELOW 90 ACROSS THE PLAINS. SUNDAY MORNING WILL ALSO BE RELATIVELY CHILLY COMPARED TO THE PAST FEW WEEKS. FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK...THE MONSOON LOOKS LIKE IT WILL RE-ESTABLISH ITSELF...AND AFTERNOON THUNDERSTORMS WILL DEVELOP EACH AFTERNOON. FOR A FEW DAYS AT LEAST...HIGHS WILL AGAIN BE BACK INTO THE 90S. AVIATION...THE PEAK WINDOW FOR TSTMS IN THE DENVER AREA WILL BE UNTIL THROUGH 00Z THEN THE FOCUS SHOULD SHIFT FURTHER EAST ACROSS THE ADJACENT PLAINS. BRIEF MVFR CIG AND VSBY RESTRICTIONS POSSIBLE IF HEAVY RAIN SHOWERS DEVELOP AT THE AIRPORTS. NORTH/NORTHWEST WINDS WILL TRANSITION TO EAST/SOUTHEASTERLY 01-02Z THEN SOUTH/SOUTHWESTERLY AFTER 04Z. HYDROLOGY...THE MAIN WINDOW FOR TSTMS IN THE FOOTHILLS WILL BE THROUGH 00Z THEN THE COVERAGE WILL BECOME MORE ISOLATED. BRIEF HEAVY RAIN THE MAIN ISSUE SO FLASH FLOODING WILL BE A THREAT IN THE BURN AREAS. THE STRONGER STORMS WILL LIKELY PRODUCE AROUND 0-25-0.50 INCHES IN 30 MINUTES...WITH LESSER CHANCE OF UP TO ONE INCH. MAIN CONCERN WILL BE TRAINING CELLS SO WILL NEED TO KEEP A CLOSE EYE ON THAT. TSTMS WITH THE POTENTIAL FOR HEAVY RAINFALL WILL RETURN THURSDAY AFTERNOON...BUT THE THREAT SHOULD BE SLIGHTLY LOWER. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COOPER LONG TERM....DANKERS AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS DENVER CO
322 PM MDT TUE JUL 31 2012 .SHORT TERM...AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE TEXAS AND OKLAHOMA PANHANDLES TONIGHT THROUGH MIDDAY WEDNESDAY...THEN IT IS EXPECTED TO SHIFT TO THE SOUTH AS A WEAK UPPER LEVEL DISTURBANCE BRUSHES ACROSS NORTHERN COLORADO LATE IN THE DAY. THE FLOW ALOFT WILL BE MORE WEST/SOUTHWESTERLY TONIGHT...THEN BE MORE WEST/NORTHWESTERLY ON WEDNESDAY. ONE ROUND OF SHOWERS AND THUNDERSTORMS IS MOVING THROUGH THE DENVER METRO AREA AT THIS TIME...WITH THE STRONGER STORMS PRODUCING UP TO ONE HALF INCH OF RAINFALL...PENNY SIZE HAIL AND WIND GUSTS OF 35-40KTS. THESE TSTMS SHOULD CONTINUE TO INITIATE MORE DEEP CONVECTION AS THEY MAKE THEIR WAY EAST. THE THREAT OF A SEVERE TSTMS DEVELOPING STILL EXISTS OVER THE NORTHEAST PLAINS LATE THIS AFTN AND EVNG. WET MICROBURSTS COULD PRODUCE DAMAGING WINDS AND HAIL TO ONE INCH IN DIAMETER. THE 15Z HRRR THIS MORNING...REFLECTED THE DEVELOPING TSTMS FAIRLY WELL SO WL GO WITH ITS TREND. IT INDICATES MORE ISOLD TSTM COVERAGE FM THE URBAN CORRIDOR WESTWARD UNTIL AROUND 03Z...THEN SWINGS ANOTHER AREA OF SHOWERS AND STORMS IN THE CWFA OVERNIGHT BUT NOT AS INTENSE...SIMILAR TO WHAT OCCURRED THIS MORNING. IF IT PANS OUT THEN THE SOUTHERN PORTION OF THE CWFA SHOULD FAIR THE BEST WITH THE SECOND ROUND. ON WEDNESDAY...PW VALUES REMAIN FAIRLY HIGH BUT WITH VALUES SLIGHTLY LOWER IN THE 0.8-0.9 RANGE. STORM MOTIONS MORE NORTHWEST TO SOUTHEAST. OVERALL CAPES NOT AS IMPRESSIVE AROUND 700 J/KG WITH SOME CIN AS WELL THROUGH 21Z. A WEAK UPPER LEVEL TROUGH MAY PROVIDE THE INITIATION FOR DEEP CONVECTION LATE WEDNESDAY AFTN. WL GO WITH SCT COVERAGE IN THE HIGH COUNTRY WITH ISOLD POPS ACROSS THE URBAN CORRIDOR AND ADJACENT PLAINS. OVERALL THE THREAT OF TSTMS PRODUCING VERY HEAVY RAIN SHOULD BE LOWER THAT TODAY. .LONG TERM...CHANGES LOOK TO BE IN STORE AS WE HEAD INTO THE WEEKEND. WESTERLY FLOW OVER THE NORTHERN U.S. IS FORECAST TO DROP A LITTLE FARTHER SOUTH WHICH WILL TEMPORARILY DISRUPT THE MONSOONAL CIRCULATION OVER THE SOUTHWESTERN PART OF THE COUNTRY. THE MAIN IMPACT FROM THIS WILL NOT ARRIVE UNTIL FRIDAY OR SATURDAY SO THURSDAY MAY HAVE ONE MORE AFTERNOON OF SHOWERS OVER THE MOUNTAINS AND OUT ACROSS THE PLAINS. TEMPERATURES WILL CONTINUE CLIMBING INTO THE LOWER AND MID 90S ON THE PLAINS THROUGH FRIDAY. ON SATURDAY...A DECENT SURFACE FRONT IS FORECAST TO DROP INTO THE STATE AS AN UPPER TROUGH PASSES FROM WYOMING OUT ONTO THE NORTHERN GREAT PLAINS. MUCH COOLER TEMPERATURES WILL RESULT...WITH A PROBABLE END TO THE STREAK OF 90+ DAYS AT KDEN. THERE COULD BE SOME MORNING CLOUDS AGAINST THE FOOTHILLS SATURDAY MORNING...BUT THE REST OF THE DAY SHOULD BE FAIRLY STABLE ACROSS THE FORECAST AREA. FOR THE REST OF THE WEEKEND AND EARLY NEXT WEEK...THE UPPER RIDGE OVER THE SOUTHWESTERN U.S. WILL BEGIN TO RE-ESTABLISH A MONSOONAL CIRCULATION. THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CREEP BACK INTO THE FORECAST WITH HIGH TEMPERATURES ONCE AGAIN CLIMBING INTO THE 90S ON THE PLAINS. && .AVIATION...ISOLD TSTMS MOVING ACROSS SRN AND ERN PORTIONS OF THE METRO AREA AT THIS TIME. WL GO WITH PRIMARILY VCTS THE REST OF THE AFTN AND EVENING. A SECONDARY ROUND OF SHOWERS MAY SPREAD ACROSS THE AREA LATE THIS EVENING AND OVERNIGHT...SIMILAR TO LAST NIGHT. MUCH OF THIS MAY REMAIN MORE SOUTH OF THE DENVER AREA. OVERALL EXPECTED VFR CONDITIONS BUT COULD SEE CIGS ON 050-060 WITH ANY TSTMS THAT REDEVELOP LATER. SHOULD SEE NORTHWESTERLY WINDS THIS AFTERNOON TRANSITION MORE EASTERLY BY THIS EVENING...THEN SWITCHING TO DRAINAGE OVERNIGHT. IF DECENT CONVECTIVE SHOWERS OCCUR OVERNIGHT OVER THE PALMER DIVIDE...THEN THE SOUTHERLY DRAINAGE WINDS MAY AGAIN GET ENHANCED LATE TONIGHT AND WEDNESDAY MORNING. && .HYDROLOGY...SLGT CHC OF TSTMS EXPECTED THE REST OF THIS AFTERNOON AND EVENING. DO NOT ANTICIPATE THE STORMS TO BE AS STRONG AS THOSE THAT OCCURRED EARLIER THIS AFTERNOON...SO BELIEVE THE THREAT OF FLOODING RAINS IN THE BURN AREAS WILL BE LOW. COULD SEE SOME REDEVELOPMENT OF SHOWERS AND STORMS AFTER 04Z THIS EVENING BUT SUSPECT THIS AREAS OF SHOWERS AND STORMS WILL REMAIN ALONG AND SOUTH OF THE INTERSTATE 70 CORRIDOR. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COOPER LONG TERM....DANKERS AVIATION...COOPER
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
1151 PM MDT MON JUL 30 2012 .UPDATE... ADDED SHOWERS AND THUNDERSTORMS FOR THE FORECAST THROUGH 5 AM FOR MOST OF SOUTHERN COLORADO WITH THE HEAVIEST ACTIVITY OVER THE CENTRAL MOUNTAINS...TO THE PALMER DIVIDE...AND THE FAR EASTERN PLAINS. ANOTHER HALF AN INCH OF PRECIP IS POSSIBLE WITH LOCALLY HIGHER AMOUNTS POSSIBLE. MOZLEY && .PREV DISCUSSION... /ISSUED 1121 PM MDT MON JUL 30 2012/ AVIATION... THUNDERSTORM ACTIVITY CONTINUES TO MOVE ACROSS KCOS AND WILL DO SO THROUGH 08Z. GUSTY OUTFLOW WINDS TO NEAR 35 KTS...AND REDUCED VIS AND CIGS TO IFR ARE LIKELY AS THE THUNDERSTORMS PASS. ANOTHER ROUND OF THUNDERSTORMS ARE FORECAST TO DEVELOP OVER THE MOUNTAINS BY TUESDAY AFTERNOON AND IMPACT KCOS AND KPUB. GUSTY OUTFLOW WINDS WILL BE THE MAIN THREAT WITH THESE THUNDERSTORMS. ANY STORMS THAT PASS OVER THE TERMINALS WILL LIKELY PRODUCE REDUCED VIS AND CIGS. 88 PREV DISCUSSION... /ISSUED 323 PM MDT MON JUL 30 2012/ SHORT TERM... (TONIGHT AND TUESDAY) .MORE INTENSE THUNDERSTORMS TODAY BRINGING THREAT OF HEAVY RAIN TO PORTIONS OF SOUTH CENTRAL AND SOUTHEAST COLORADO... UPPER HIGH TO THE SOUTH CONTINUES TO NUDGE THE MAIN TAP OF THE MONSOON PLUME FARTHER WEST AND NORTH...HOWEVER...YESTERDAY`S FRONT HAS COMPENSATED SOME WITH AN INCREASE IN LOW LEVEL MOISTURE. THIS HAS RESULTED IN HIGHER CAPES TODAY ACROSS THE SOUTHEAST MTS/PLAINS...AND STORMS ON RADAR HAVE DEFINITELY BEEN STRONGER. CAPE VALUES OFF SPC MESONET SHOWING VALUES SHOWING AROUND 1000-2000 J/KG...THOUGH WITH A LITTLE MIXING...THEY MAY DROP BACK TO AROUND 1000-1500 J/KG. DEEP LAYER SHEARS ARE RUNNING AROUND 20-30KTS...SO SHOULD NOT LOOKING AT A WIDESPREAD SEVERE RISK...BUT CERTAINLY SOME STORMS COULD PULSE UP AND PRODUCE HAIL TO AROUND 1 INCH IN DIAMETER...ESPECIALLY OVER/NEAR THE HIGHER TERRAIN. HRRR BRINGS SEVERAL WAVES OF THUNDERSTORMS OFF THE SOUTHEAST MTS...PARTICULARLY ACROSS THE PIKES PEAK REGION WITH THUNDERSTORMS SPREADING OFF INTO THE SOUTHEAST PLAINS DURING THE EVENING. STORM MOTIONS OFF RADAR HAVE BEEN TO THE EAST NORTHEAST AROUND 10-15 MPH...HOWEVER WITH CONTINUAL REGENERATION...IF STORMS TRACK OVER THE SAME LOCATION...LOCALLY HEAVY RAINFALL WITH THE POTENTIAL FOR FLASH FLOODING WILL BE A CONCERN...ESPECIALLY FOR THE WALDO CANYON BURN SCAR. ONE STORM HAS ALREADY COME FAIRLY CLOSE...THOUGH JUST MISSED TO THE SOUTH. HRRR SHOWS ANOTHER LINE OF THUNDERSTORMS MOVING OFF THE PIKES PEAK REGION AND POTENTIAL AFFECTING THE BURN SCAR AROUND 22-23Z. GIVEN THAT STORMS ARE STRONGER TODAY...AND CAPABLE OF HIGHER RAINFALL RATES (UP TO 1.5 INCH PER HOUR)...FLOODING ON THE WALDO CANYON BURN SCAR IS A GREATER CONCERN. HOWEVER...STORMS WILL STILL BE HIT OR MISS...SO CLOSE MONITORING OF THE BURN SCAR WILL CONTINUE. FOR TONIGHT...MODELS IN GENERAL AGREEMENT SPREADING THUNDERSTORMS EASTWARD ACROSS THE PLAINS THROUGH THE EVENING BEFORE DIMINISHING TOWARDS MORNING. TUESDAY LOOKS LIKE A SIMILAR EVENT TO TODAY...WITH LOW LEVEL MOISTURE STILL IN PLACE...BUT MAIN MONSOON PLUME SHIFTED FARTHER WEST AND NORTH. MAIN TRACK OF ANY SHORTWAVES AROUND THE PERIPHERY OF THE UPPER RIDGE MAY BE FARTHER NORTH AS WELL...BUT WITH CONVECTIVE HEATING...MODELS BREAK OUT ANOTHER ROUND OF SCATTERED THUNDERSTORMS ACROSS THE MOUNTAINS AREAS...WITH GREATEST COVERAGE ACROSS THE SOUTHEAST MTS. CAPES WILL PROBABLY END UP BEING SIMILAR TODAY...SO SMALL HAIL AND HEAVY RAINFALL WILL BE THE PRIMARY THREATS. FLASH FLOODING ON THE WALDO CANYON BURN SCAR WILL BE A CONCERN ONCE AGAIN. LONG TERM... (TUESDAY NIGHT THROUGH NEXT MONDAY) TEMPERATURES AND POPS ARE THE PRIMARY METEOROLOGICAL ISSUES DURING THE LONGER TERM. RECENT COMPUTER MODELS SUGGEST THAT UPPER HIGH CENTERED OVER THE TEXAS PANHANDLE AT 00Z WEDNESDAY ATTEMPTS TO SLOWLY SHIFT INTO CENTRAL OKLAHOMA BY 12Z SATURDAY BEFORE PUSHING BACK INTO THE TEXAS PANHANDLE REGION BY NEXT MONDAY. FAVORABLE ATMOSPHERIC MOISTURE/HIGH PRECIPITABLE WATER VALUES/MONSOONAL PLUME ROTATING AROUND THE UPPER HIGH WILL CONTINUE TO IMPACT THE FORECAST DISTRICT AT TIMES THROUGH THE LONGER TERM. IN ADDITION...INCREASING SHORT-WAVE ACTIVITY AS WELL AS SEVERAL NORTHERLY SURGES ARE PROJECTED TO IMPACT THE FORECAST DISTRICT AT TIMES FROM TUESDAY NIGHT INTO AT LEAST THE UPCOMING WEEKEND. AS DISCUSSED DURING PREVIOUS DISCUSSIONS...ISOLATED TO SCATTERED PRIMARILY AFTERNOON AND EVENING THUNDERSTORMS(SOME CONTAINING LOCALLY HEAVY RAIN AND HAIL) ARE ANTICIPATED OVER MANY SECTIONS OF THE FORECAST DISTRICT AT TIMES DURING THE LONGER TERM. AS ALWAYS...PLEASE REMEMBER THAT THE STRONGER STORMS DURING THE LONGER TERM WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN AND FLASH FLOODING POTENTIAL(ESPECIALLY OVER BURN SCAR REGIONS SUCH AS THE WALDO CANYON BURN SCAR). WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY. FINALLY...MAXIMUM AND MINIMUM TEMPERATURES DURING THE LONGER TERM SHOULD CONTINUE TO RUN AT TO ABOVE EARLY AUGUST CLIMATOLOGICAL AVERAGES IN COMBINATION WITH GENERALLY LOW-GRADE GRADIENT WINDS. AVIATION... TSRA WILL BE MOST LIKELY TO IMPACT THE COS TAF SITE THIS EVENING...WITH HEAVY RAIN...AND ERRATIC GUSTY WINDS UP TO 45 KTS THE PRIMARY THREAT. SOME SMALL HAIL WILL ALSO BE POSSIBLE. LESS OF A CHANCE FOR -TSRA TO AFFECT THE KPUB AND KALS TAF SITE...SO WILL MAINTAIN VCTS IN TAFS THERE. WINDS SHOULD SHIFT OUT OF THE NORTH TO NORTHWEST WITH CONVECTIVE OUTFLOWS SPREADING OFF THE MOUNTAINS DURING THE 23-00Z TIME FRAME FOR KCOS AND KPUB. WINDS AND THUNDERSTORMS SHOULD DIMINISH THROUGH THE EVENING. ANOTHER ROUND OF THUNDERSTORMS WILL BE POSSIBLE AGAIN ON TUESDAY...WITH KCOS UNDER THE GREATEST RISK FOR -TSRA. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 88/40
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1121 PM MDT MON JUL 30 2012 .AVIATION... THUNDERSTORM ACTIVITY CONTINUES TO MOVE ACROSS KCOS AND WILL DO SO THROUGH 08Z. GUSTY OUTFLOW WINDS TO NEAR 35 KTS...AND REDUCED VIS AND CIGS TO IFR ARE LIKELY AS THE THUNDERSTORMS PASS. ANOTHER ROUND OF THUNDERSTORMS ARE FORECAST TO DEVELOP OVER THE MOUNTAINS BY TUESDAY AFTERNOON AND IMPACT KCOS AND KPUB. GUSTY OUTFLOW WINDS WILL BE THE MAIN THREAT WITH THESE THUNDERSTORMS. ANY STORMS THAT PASS OVER THE TERMINALS WILL LIKELY PRODUCE REDUCED VIS AND CIGS. MOZLEY && .PREV DISCUSSION... /ISSUED 323 PM MDT MON JUL 30 2012/ SHORT TERM... (TONIGHT AND TUESDAY) ..MORE INTENSE THUNDERSTORMS TODAY BRINGING THREAT OF HEAVY RAIN TO PORTIONS OF SOUTH CENTRAL AND SOUTHEAST COLORADO... UPPER HIGH TO THE SOUTH CONTINUES TO NUDGE THE MAIN TAP OF THE MONSOON PLUME FARTHER WEST AND NORTH...HOWEVER...YESTERDAY`S FRONT HAS COMPENSATED SOME WITH AN INCREASE IN LOW LEVEL MOISTURE. THIS HAS RESULTED IN HIGHER CAPES TODAY ACROSS THE SOUTHEAST MTS/PLAINS...AND STORMS ON RADAR HAVE DEFINITELY BEEN STRONGER. CAPE VALUES OFF SPC MESONET SHOWING VALUES SHOWING AROUND 1000-2000 J/KG...THOUGH WITH A LITTLE MIXING...THEY MAY DROP BACK TO AROUND 1000-1500 J/KG. DEEP LAYER SHEARS ARE RUNNING AROUND 20-30KTS...SO SHOULD NOT LOOKING AT A WIDESPREAD SEVERE RISK...BUT CERTAINLY SOME STORMS COULD PULSE UP AND PRODUCE HAIL TO AROUND 1 INCH IN DIAMETER...ESPECIALLY OVER/NEAR THE HIGHER TERRAIN. HRRR BRINGS SEVERAL WAVES OF THUNDERSTORMS OFF THE SOUTHEAST MTS...PARTICULARLY ACROSS THE PIKES PEAK REGION WITH THUNDERSTORMS SPREADING OFF INTO THE SOUTHEAST PLAINS DURING THE EVENING. STORM MOTIONS OFF RADAR HAVE BEEN TO THE EAST NORTHEAST AROUND 10-15 MPH...HOWEVER WITH CONTINUAL REGENERATION...IF STORMS TRACK OVER THE SAME LOCATION...LOCALLY HEAVY RAINFALL WITH THE POTENTIAL FOR FLASH FLOODING WILL BE A CONCERN...ESPECIALLY FOR THE WALDO CANYON BURN SCAR. ONE STORM HAS ALREADY COME FAIRLY CLOSE...THOUGH JUST MISSED TO THE SOUTH. HRRR SHOWS ANOTHER LINE OF THUNDERSTORMS MOVING OFF THE PIKES PEAK REGION AND POTENTIAL AFFECTING THE BURN SCAR AROUND 22-23Z. GIVEN THAT STORMS ARE STRONGER TODAY...AND CAPABLE OF HIGHER RAINFALL RATES (UP TO 1.5 INCH PER HOUR)...FLOODING ON THE WALDO CANYON BURN SCAR IS A GREATER CONCERN. HOWEVER...STORMS WILL STILL BE HIT OR MISS...SO CLOSE MONITORING OF THE BURN SCAR WILL CONTINUE. FOR TONIGHT...MODELS IN GENERAL AGREEMENT SPREADING THUNDERSTORMS EASTWARD ACROSS THE PLAINS THROUGH THE EVENING BEFORE DIMINISHING TOWARDS MORNING. TUESDAY LOOKS LIKE A SIMILAR EVENT TO TODAY...WITH LOW LEVEL MOISTURE STILL IN PLACE...BUT MAIN MONSOON PLUME SHIFTED FARTHER WEST AND NORTH. MAIN TRACK OF ANY SHORTWAVES AROUND THE PERIPHERY OF THE UPPER RIDGE MAY BE FARTHER NORTH AS WELL...BUT WITH CONVECTIVE HEATING...MODELS BREAK OUT ANOTHER ROUND OF SCATTERED THUNDERSTORMS ACROSS THE MOUNTAINS AREAS...WITH GREATEST COVERAGE ACROSS THE SOUTHEAST MTS. CAPES WILL PROBABLY END UP BEING SIMILAR TODAY...SO SMALL HAIL AND HEAVY RAINFALL WILL BE THE PRIMARY THREATS. FLASH FLOODING ON THE WALDO CANYON BURN SCAR WILL BE A CONCERN ONCE AGAIN. LONG TERM... (TUESDAY NIGHT THROUGH NEXT MONDAY) TEMPERATURES AND POPS ARE THE PRIMARY METEOROLOGICAL ISSUES DURING THE LONGER TERM. RECENT COMPUTER MODELS SUGGEST THAT UPPER HIGH CENTERED OVER THE TEXAS PANHANDLE AT 00Z WEDNESDAY ATTEMPTS TO SLOWLY SHIFT INTO CENTRAL OKLAHOMA BY 12Z SATURDAY BEFORE PUSHING BACK INTO THE TEXAS PANHANDLE REGION BY NEXT MONDAY. FAVORABLE ATMOSPHERIC MOISTURE/HIGH PRECIPITABLE WATER VALUES/MONSOONAL PLUME ROTATING AROUND THE UPPER HIGH WILL CONTINUE TO IMPACT THE FORECAST DISTRICT AT TIMES THROUGH THE LONGER TERM. IN ADDITION...INCREASING SHORT-WAVE ACTIVITY AS WELL AS SEVERAL NORTHERLY SURGES ARE PROJECTED TO IMPACT THE FORECAST DISTRICT AT TIMES FROM TUESDAY NIGHT INTO AT LEAST THE UPCOMING WEEKEND. AS DISCUSSED DURING PREVIOUS DISCUSSIONS...ISOLATED TO SCATTERED PRIMARILY AFTERNOON AND EVENING THUNDERSTORMS(SOME CONTAINING LOCALLY HEAVY RAIN AND HAIL) ARE ANTICIPATED OVER MANY SECTIONS OF THE FORECAST DISTRICT AT TIMES DURING THE LONGER TERM. AS ALWAYS...PLEASE REMEMBER THAT THE STRONGER STORMS DURING THE LONGER TERM WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN AND FLASH FLOODING POTENTIAL(ESPECIALLY OVER BURN SCAR REGIONS SUCH AS THE WALDO CANYON BURN SCAR). WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY. FINALLY...MAXIMUM AND MINIMUM TEMPERATURES DURING THE LONGER TERM SHOULD CONTINUE TO RUN AT TO ABOVE EARLY AUGUST CLIMATOLOGICAL AVERAGES IN COMBINATION WITH GENERALLY LOW-GRADE GRADIENT WINDS. AVIATION... TSRA WILL BE MOST LIKELY TO IMPACT THE COS TAF SITE THIS EVENING...WITH HEAVY RAIN...AND ERRATIC GUSTY WINDS UP TO 45 KTS THE PRIMARY THREAT. SOME SMALL HAIL WILL ALSO BE POSSIBLE. LESS OF A CHANCE FOR -TSRA TO AFFECT THE KPUB AND KALS TAF SITE...SO WILL MAINTAIN VCTS IN TAFS THERE. WINDS SHOULD SHIFT OUT OF THE NORTH TO NORTHWEST WITH CONVECTIVE OUTFLOWS SPREADING OFF THE MOUNTAINS DURING THE 23-00Z TIME FRAME FOR KCOS AND KPUB. WINDS AND THUNDERSTORMS SHOULD DIMINISH THROUGH THE EVENING. ANOTHER ROUND OF THUNDERSTORMS WILL BE POSSIBLE AGAIN ON TUESDAY...WITH KCOS UNDER THE GREATEST RISK FOR -TSRA. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 88/40
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
956 PM EDT WED AUG 1 2012 .UPDATE... ISOLATED STRONG TO SEVERE STORM POTENTIAL CONTINUES ACROSS THE NORTHERN TIER OF THE FORECAST AREA EARLY TONIGHT. SPC ALSO UPDATED TO INCLUDE PART OF THIS AREA IN A SLIGHT RISK...HOWEVER THE MAJORITY OF THE MORE INTENSE DEVELOPMENT HAS PASSED. SEVERAL CLUSTERS OF CONVECTION NEAR A SFC BOUNDARY HAVE BEEN TRACKING SEWD FROM SOUTHERN TN AND THE HRRR HAS THIS DEVELOPMENT PERSISTING FARTHER SOUTH UNTIL JUST NORTH OF ATLANTA BY NEAR 06Z. PER OBSERVED DEWPOINT DEPRESSIONS AHEAD OF THE STORMS AND RECENT SOUNDING DATA...THE LOW LEVELS ARE QUITE DRY AND STORM DEVELOPMENT IS LIKELY ELEVATED. LARGE HAIL AND DAMAGING WINDS HAVE BEEN THE MAIN CONCERNS...HOWEVER SOME CELLS HAVE SHOWN ROTATION ALBEIT ONLY OBSERVABLE ABOUT 6KFT AGL. ADJUSTED POPS TO LIKELY AND CHANCE IN THE NORTH BEFORE MIDNIGHT AND THEN SLIGHT TO NO CHANCE THE REST OF THE OVERNIGHT. MADE OTHER ADJUSTMENTS TO TEMP AND DEWPOINT TRENDS...BUT DID NOT AFFECT OVERNIGHT MINS. PREVIOUS DISCUSSION FOLLOWS... 03 && .PREV DISCUSSION... /ISSUED 252 PM EDT WED AUG 1 2012/ .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... CURRENT SATELLITE LOOP SHOW MOSTLY CLEAR SKIES OVER THE AREA. THERE IS SOME CU BEGINNING TO DEVELOP ACROSS WEST AND CENTRAL GA SO THIS LOOKS LIKE IT COULD BE THE BEGINNING OF SOME ISOLATED SHRA/TSRA THIS AFTERNOON/EVENING. THERE IS A WEAK STATIONARY BOUNDARY OVER N GA THAT MAY ACT AS A FOCUSING MECHANISM FOR THUNDERSTORM DEVELOPMENT. THE KEY IS GOING TO BE JUST HOW MUCH DRIER AIR HAS FILTER INTO THE AREA UNDER THE WEAK RIDGE BUILDING IN FROM THE NORTH AND HOW STRONG IS THE INSTABILITY ACROSS THE AREA. LOOKS LIKE WE WILL SEE SOME ISOLATED TO SCATTERED SHRA/TSRA DEVELOP ACROSS NORTH GA BUT IT SHOULD DISSIPATE OUT SHORTLY AFTER SUNSET. MOISTURE INCREASES SOME THURSDAY FROM THE NORTH AS THE RIDGE BREAKS DOWN A BIT MORE THROUGH THE END OF THE WEEK. TEMPS WILL STAY NEAR SEASONAL NORMS THROUGH THE SHORT TERM. 01 && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... UPPER LEVEL HIGH PRESSURE RIDGE REMAINS SITUATED OVER TEXAS INTO THE EXTENDED PERIOD...WITH NORTHWEST FLOW PREVAILING ACROSS THE TENNESSEE VALLEY AND INTO GEORGIA. THIS FLOW WILL CONTINUE TO USHER UPPER LEVEL DISTURBANCES INTO THE REGION INTO THE WEEKEND. THESE FEATURES...COMBINED WITH AMPLE DAYTIME HEATING WILL KEEP SLIGHT CHANCE TO CHANCE THUNDERSTORMS ACROSS THE AREA. INTO EARLY NEXT WEEK...HIGH PRESSURE RIDGE OVER THE ATLANTIC BECOMES MORE DOMINANT ACROSS THE SOUTHEAST AS LOW PRESSURE DEEPENS OVER SOUTH CENTRAL CANADA. THIS LOW WILL DRAG A FRONTAL BOUNDARY THROUGH THE TENNESSEE VALLEY BY MONDAY MORNING...AND PUSH INTO NORTHWEST GEORGIA BY MONDAY AFTERNOON. TIMING OF THIS SYSTEM AS IT PUSHES THROUGH DIFFERS SLIGHTLY BY MODEL...SO HAVE MADE NO MAJOR ADJUSTMENTS TO THE CURRENT FORECAST BASED ON THE UNCERTAINTY. HIGH PRESSURE BUILDS BACK INTO THE REGION BEHIND THE FRONT...AND ANTICIPATE DIURNALLY DRIVEN CONVECTION TO RETURN BY MID WEEK. PREVIOUS FORECAST CONTINUES TO APPEAR ON TRACK...AND HAVE ADDED THE PREVIOUS DISCUSSION BELOW... 31 /ISSUED 438 AM EDT WED AUG 1 2012/ LITTLE CHANGE IN THE PATTERN...HENCE THE SCATTERED AFTERNOON AND EVENING THUNDERSTORMS TO CONTINUE. UPPER LEVEL LOW REMAINS OVER TEXAS AS STORM SYSTEM RIDE OVER THE TOP THROUGH THE PLAINS AND OHIO VALLEY. THE HIGH OFF THE COAST CONTINUES TO HOLD A WARM MOIST AIR MASS OVER THE SOUTHEAST... THOUGH THE GFS MAINTAINS A HIGHER MEAN RH OVER THE AREA THAN DOES THE ECMWF. THE GFS SOLUTION PREFERRED. SUNDAY NIGHT INTO MONDAY THEY BOTH HAVE A COLD FRONT MOVING THROUGH EASTERN TENNESSEE AND INTO NORTHERN GEORGIA MONDAY MORNING. IT SETTLES INTO CENTRAL/SOUTH GEORGIA AND WEAKENS BY TUESDAY...BUT PLENTY OF MOISTURE REMAINS OVER THE AREA TO CONTINUE THE AFTERNOON AND EVENING THUNDERSTORMS. LIKEWISE...SEE NO CHANGE IN THE TEMPERATURES THROUGH THE PERIOD. 37 && .AVIATION... 00Z UPDATE... VFR CIGS EXPECTED WITH SOME MVFR VSBYS POSSIBLY EARLY THURSDAY MORNING. STORM AND SHOWER ACTIVITY HAS MOSTLY DIMINISHED THIS EVENING NEAR THE MAJORITY OF TAF SITES...HOWEVER THERE IS AN ISOLATED CHANCE OF THUNDERSTORM DEVELOPMENT BEFORE MIDNIGHT. VSBYS OF 4SM WITH BR ARE POSSIBLE IN THE EARLY MORNING THOUGH NOT EXPECTING AS LOW AS THE PREVIOUS DAY. WINDS SHOULD STAY LIGHT OUT OF THE WEST TO WNW OR VRB OVERNIGHT AND BECOME MORE SW UNDER 10KTS THURSDAY. THERE IS A LOW CHANCE FOR CONVECTION THURSDAY AFTERNOON...HOWEVER FEEL PROB30 FROM 19-23Z IS JUSTIFIABLE. //ATL CONFIDENCE...00Z UPDATE... MEDIUM CONFIDENCE IN CONVECTION THURSDAY. HIGH CONFIDENCE ALL ELSE. 03 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 71 95 72 91 / 30 20 20 40 ATLANTA 75 95 74 90 / 30 20 20 40 BLAIRSVILLE 65 88 65 86 / 60 20 20 40 CARTERSVILLE 67 94 69 92 / 50 20 20 40 COLUMBUS 74 97 74 94 / 30 20 20 40 GAINESVILLE 73 94 73 90 / 40 20 20 40 MACON 74 96 73 94 / 20 20 20 30 ROME 71 96 71 94 / 50 20 20 50 PEACHTREE CITY 70 94 71 91 / 30 20 20 40 VIDALIA 74 97 74 93 / 20 20 20 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...01/03 LONG TERM....31 AVIATION...03
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
114 AM CDT TUE JUL 31 2012 .DISCUSSION... 310 PM CDT SHORT TERM...THIS EVENING THROUGH THURSDAY... PRIMARY CONCERN IS CONVECTIVE CHANCES THIS EVENING ACROSS NORTHERN ILLINOIS. WATER VAPOR IMAGERY TODAY SHOWS STRONG MIDLEVEL RIDGING CENTERED OVER THE SOUTHERN PLAINS AND A FAIRLY STRONG SHORTWAVE TROUGH OVER ONTARIO...WITH ANOTHER TROUGH OFF THE PACIFIC NORTHWEST COAST. THE TROUGH OVER ONTARIO WILL DIG SOUTHEAST...WITH ASSOCIATED SURFACE LOW DRAGGING COOL FRONT ACROSS LAKE MICHIGAN AND ACROSS CWA THIS EVENING THROUGH TONIGHT. THIS EVENING...THOUGH THE BEST FORCING IN TERMS OF POSITIVE VORTICITY ADVECTION WILL BE FOCUSED NORTHEAST OF THE CWA CLOSER TO THE TROUGH AXIS...IT APPEARS THERE WILL BE DECENT CONVERGENCE ALONG AND AHEAD OF THE COOL FRONT...ALONG WITH 0-6 KM BULK SHEAR VALUES INCREASING TO 30 TO 35 KT AND NORTHERN ILLINOIS BEING IN THE EXIT REGION OF AN ~80 KT UPPER LEVEL JET STREAK. SO THERE IS SOME SUPPORT FOR ORGANIZED UPDRAFTS. SUSPECT THAT THE MLCAPE BEING PROGGED THIS BY THE NAM AND RAP ACROSS FAR NORTHERN IL...IN EXCESS OF 2500 J/KG IS A BIT OVERDONE BECAUSE FCST SURFACE TEMPS AND DEWPOINTS ARE LIKELY A BIT TOO HIGH...BUT THERE SHOULD STILL BE AT LEAST 1500 J/KG TO TAP INTO...WITH MINIMAL CIN. WITH TEMPERATURES ONLY SLOWLY COOLING AHEAD OF THE FRONT...LOW LEVEL LAPSE RATES ARE EXPECTED TO REMAIN FAIRLY STEEP AND DRY AIR IN THE LOWER LEVELS MAY SUPPORT DCAPE VALUES IN EXCESS OF 1000 J/KG. THUS PRIMARY THREAT WITH ANY TSRA IS EXPECTED TO BE DAMAGING WIND GUSTS...THOUGH THE GOOD DEEP LAYER SHEAR COULD ALSO ALLOW FOR AT LEAST MARGINALLY SEVERE HAIL. HAVE INCREASED POPS JUST A BIT ALONG AND NORTH OF I-80...THOUGH STILL EXPECTING SCATTERED COVERAGE AT MOST...WITH EARLY EVENING POPS CONFINED TO CLOSER TO THE WISCONSIN BORDER...SPREADING INTO THE CHICAGO AREA LATER IN THE EVENING. DIURNAL DECREASE IN INSTABILITY LATER THIS EVENING AND OVERNIGHT WILL LIKELY LEND TO DECREASE IN INTENSITY AND COVERAGE OF CONVECTION. WILL MAINTAIN LOW POPS FOR ISOLATED SHRA/TSRA AFTER MIDNIGHT AS THE FRONT PUSHES THROUGH. KEPT THE INHERITED SLIGHT POPS TUESDAY MORNING PORTIONS OF NORTHWEST INDIANA MAINLY EAST OF I-65...WITH THE FRONT EXPECTED TO ON THE DOORSTEP BY THAT TIME. THE THING TO WATCH FOR WOULD BE A SLOWER FRONTAL TIMING...WHICH MAY ALLOW SOME INSTABILITY TO REBUILD AND PRESENT SOME OPPORTUNITY FOR THE FAR SOUTHEAST CWA TO SEE TSRA LATE MORNING/EARLY AFTERNOON. FOR NOW...DO NOT THINK THIS IS A LIKELY SCENARIO AND HAVE THE WHOLE CWA DRY AFTER 15Z TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON TUESDAY...WITH NORTHERLY WINDS...THOUGH THE AIR MASS REALLY WONT BE MUCH COOLER. AREAS AWAY FROM THE LAKE SHOULD ACTUALLY REACH NEAR OR A BIT ABOVE 90 UNDER FULL SUN...WITH ONSHORE WINDS KEEPING THE LAKEFRONT IN THE MID 80S. THE MOST NOTICEABLE DIFFERENCE BEHIND THE FRONT IS EXPECTED TO BE A DRIER AIR MASS. THUS DESPITE ABOVE NORMAL TEMPERATURES...THE NORTHERLY BREEZE AND MANAGEABLE HUMIDITY LEVELS WILL MAKE IT A FAIRLY COMFORTABLE DAY...ESPECIALLY CONSIDERING ALL THE EXTREME HEAT WEVE SEEN THIS SUMMER. WEDNESDAY WILL BE SIMILARLY WARM AND SUNNY...EXCEPT WITH MUCH LIGHTER WINDS WITH HIGH PRESSURE OVERHEAD. IF WINDS ARENT ONSHORE TO START TO THE DAY ALONG THE LAKEFRONT...A LAKE BREEZE SHOULD BE ABLE TO GET GOING QUICKLY WITH SUCH LIGHT FLOW OVER THE AREA. THIS WILL AGAIN LIMIT HIGH TEMPERATURES A BIT ALONG THE LAKESHORE. THURSDAY PRESENTS A MORE INTERESTING SCENARIO IN TERMS OF THE HIGH TEMPERATURE FORECAST. THE CWA WILL NOT BE IN A FAVORED AREA WITH REGARD TO THE POSITION OF THE CENTER OF THE MIDLEVEL RIDGE...WHICH WILL STILL BE OVER THE SOUTHERN PLAINS. HOWEVER...AN 850 MB THERMAL RIDGE WILL PUSH INTO THE AREA WITH WARM ADVECTION BRINGING 850 MB TEMPS TO HIGHER THAN 20C BY THE AFTERNOON...SUCH AS ON THE WELL PERFORMING ECMWF MODEL. WITH FULL SUN AND DEEP MIXING...THIS WOULD SUPPORT HOT TEMPERATURES IN THE MID AND UPPER 90S. HOWEVER...BOTH THE NAM AND ECMWF...WHICH HAVE THE HOTTEST MAX TEMPS FCST...ALSO SUGGEST FAIRLY HIGH RH AT THE MID AND UPPER LEVELS...WHICH COULD BE IN THE FORM OF CONVECTIVE MID AND HIGH CLOUD DEBRIS. THINK CLOUDS WILL BE THE LIMITING FACTOR FOR TEMPS ON THURSDAY...BUT WITH THE VERY WARM THERMAL PROFILES...RAISED TEMPS A FEW DEGREES FROM INHERITED TO MAINLY LOW 90S. IF THERE IS LESS CLOUD COVER...CERTAINLY COULD SEE THE HOTTER TEMPS REALIZED. ALSO...WINDS ALOFT ARE EXPECTED TO BE WEAK ENOUGH TO ALLOW FOR A LATE DAY LAKE BREEZE TO PUSH INLAND...WHICH MAY BRING SOME MINOR COOLING. FORCING FOR CONVECTION LOOKS RATHER WEAK AND MAINLY THURSDAY AFTERNOON...WITH SHORT WAVE MOVING TO NORTH AND WEAK COOL FRONT STARTING TO DROP INTO AREA...BUT WILL MAINTAIN INHERITED SLIGHT POPS FOR NOW FOR SHRA/TSRA. MOST OF THE AREA WILL LIKELY REMAIN DRY. RC LONG TERM...THURSDAY EVENING THROUGH MONDAY.. SHORT WAVE MOVING THROUGH THE NORTHERN GREAT LAKES THU EVENING WITH ASSOCIATED WEAK SURFACE TROF/FRONT DROPPING INTO NORTHERN IL/NORTHWEST IN. WITH BEST FORCING FURTHER NORTH AND ONLY WEAK SURFACE CONVERGENCE...AND CONSIDERING STRENGTH OF ONGOING DROUGHT...WILL ONLY CARRY 20-30 PCT POPS. REMNANTS OF FRONT THEN HANG UP OVER THE AREA FRIDAY BUT AGAIN WITH ONLY WEAK LOW LEVEL CONVERGENCE AND NO UPPER LEVEL SUPPORT...WILL JUST MAINTAIN SLIGHT CHANCE POPS FOR FRIDAY. GFS PUSHES FRONT THROUGH AND DEVELOPS EAST WINDS OVER THE AREA FRIDAY WHILE ECMWF HAS A WEAK WISHY WASHY SURFACE PATTERN. EITHER WAY LAKE BREEZE LIKELY TO KEEP TEMPS IN LOW TO MID 80S LAKEFORNT BUT NEAR 90 SOUTH TOWARDS PONTIAC. MEANWHILE MUCH MORE POTENT TROF/UPPER LOW BARRELS INTO WESTERN CANADA COAST WED AND PLOWS THROUGH NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS THU AND FRI. THIS WILL ACT TO SHOVE UPPER RIDGE AND ASSOCIATED HEAT DOME EASTWARD INTO THE MIDWEST AND GREAT LAKES BY SATURDAY. SOUTHWEST FLOW AHEAD OF APPROACHING TROF PUSHES 850 TEMPS TO AROUND 22C SATURDAY. WITH UNCERTAINTY ON CLOUD COVER HESITANT TO RAISE TEMPS TOO MUCH. WILL GO WITH TEMPS IN LOWER 90S BUT MID TO UPPER 90S NOT OUT OF THE QUESTION IF WE GET ENOUGH SUN. BEST CHANCE OF WIDESPREAD RAIN IN A LONG TIME SAT AFTN AND EVENING AS STRONG UPPER TROF/UPPER LOW MOVES THROUGH THE GREAT LAKES AND STRONG COLD FRONT PUSHES THROUGH THE AREA. 12Z ECMWF A BITY SLOWER ON ARRIVAL OF FRONT AND THUNDERSTORMS...MORE LIKELY SAT NIGHT INTO SUN MORNING. TURNING COOLER AND DRIER SUN AND MON. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * TSRA PSBL BTWN 08 AND 10Z. * SW WINDS BECOME NW IN THE PRE DAWN HOURS...AND THEN BECOME N BY NOON. * LAKE BREEZE LIKELY IN THE MID AFTERNOON SHIFTING WINDS TO ENE OR E. JEE //DISCUSSION...UPDATED 06Z... A LINE OF THUNDERSTORMS EXTENDS FROM GRAND HAVEN MI THROUGH SOUTH CENTRAL WI. IN GENERAL THE LINE IS MOVING SE AROUND 35 KT...WITH RFD...ORD...AND DPA HAVING THE BEST CHANCE OF TSRA MOVING OVERHEAD. AS SUCH PUT TWO HOUR TEMPOS IN FOR TSRA. MAIN THREATS FROM THE TSRA WILL BE FREQUENT CLOUD TO GROUND LIGHTNING...BRIEF HEAVY DOWNPOURS...AND 30 TO 40 KT WIND GUSTS. EXPECTING TS TO WEAKEN AS THEY ENTER NORTHERN ILLINOIS THEREFORE NOT AS CONFIDENT THAT A TSRA WILL IMPACT MDW OR GYY...BUT KEPT A VCTS IN PLACE FOR BOTH LOCATIONS SINCE TSRA WILL PROBABLY BE IN THE AREA. THE COLD FRONT THAT IS SUPPORTING THESE THUNDERSTORMS WILL PASS THROUGH THE REGION CLOSELY BEHIND THE TSRA. WINDS WILL SHIFT TO NW BEHIND THE FRONT AND MID LEVEL CLOUDS WILL THIN TO SCT. WINDS WILL CONTINUE TO TURN TO THE N BY NOON WITH A LAKE BREEZE LIKELY IN THE MID AFTERNOON. CURRENTLY HAVE THE LAKE BREEZE TURNING ORD AND MDW WINDS ENE TO E AT 21Z...BUT NOT ENTIRELY CONFIDENT WITH THAT TIMING. SKIES CLEAR AND WINDS DIMINISH AS HIGH PRESSURE MOVES IN FROM THE NORTH. JEE //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN TIMING OF TSRA AT ORD...MEDIUM CONFIDENCE WITH VCTS AT MDW. * HIGH CONFIDENCE IN CIG VALUES AND TRENDS. * HIGH CONFIDENCE IN WIND TRENDS...MEDIUM CONFIDENCE WITH TIMING OF LAKE BREEZE. JEE //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY...VFR. THURSDAY THROUGH SATURDAY...VFR. CHC SHRA/TSRA W/PATCHY MVFR CIGS. SUNDAY...VFR. BEACHLER && .MARINE... 226 PM CDT LOW PRESSURE MOVING ACROSS SOUTHERN ONTARIO...WILL DRAG A COLD FRONT DOWN THE LAKE TONIGHT. SOME STRONG TO SEVERE THUNDERSTORMS COULD OCCUR ACROSS THE LAKE THIS EVENING AHEAD OF THE FRONT. ONCE THE FRONT PASSES THE WINDS WILL SWITCH OUT OF THE NORTH UP TO 25 KT. THESE STRONGER WINDS WILL CONTINUE ACROSS THE SOUTH HALF OF THE LAKE DURING THE DAY ON TUESDAY. WAVES OVER 4 FEET ARE POSSIBLE ALONG THE INDIANA NEAR SHORE WATERS. THIS COULD RESULT IN HAZARDS TO SMALL CRAFT FOR TUESDAY EVENING THROUGH WEDNESDAY MORNING. HIGH PRESSURE WILL BUILD IN ACROSS THE LAKE TUESDAY NIGHT INTO WEDNESDAY. THIS WILL RESULT IN ABATING WINDS FOR A PERIOD TUESDAY NIGHT INTO WEDNESDAY. THE WINDS LOOK TO TURN SOUTHERLY AT 10 TO 20 KT AGAIN BY THURSDAY AS THE SURFACE HIGH SHIFTS EASTWARD ACROSS THE OHIO VALLEY. ANOTHER AREA OF LOW PRESSURE MAY PUSH ANOTHER COLD FRONT ACROSS THE LAKE LATE THURSDAY AND THURSDAY NIGHT...BRINGING ANOTHER PUSH OF NORTHERLY FLOW DOWN THE LAKE. IN THE EXTENDED PERIOD IT APPEARS THAT A STRONGER STORM SYSTEM MAY MOVE ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION OVER THE WEEKEND. THIS COULD PRODUCE A PERIOD OF STRONGER WINDS ACROSS THE LAKE. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...HIGH RIP CURRENT RISK...ILZ014...10 AM TUESDAY TO 10 AM WEDNESDAY. IN...HIGH RIP CURRENT RISK...INZ001-INZ002...10 AM TUESDAY TO 10 AM WEDNESDAY. LM...SMALL CRAFT ADVISORY...LMZ742-LMZ743-LMZ744-LMZ745...4 PM TUESDAY TO 10 AM WEDNESDAY. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1222 PM CDT TUE JUL 31 2012 .AVIATION... VFR WX WILL BE SEEN THROUGH 06Z/01 AS HIGH PRESSURE BUILDS INTO THE WESTERN GREAT LAKES. AFT 06Z/01 THE POSSIBILITY EXISTS FOR MVFR CONDITIONS TO DEVELOP DUE TO LIGHT WINDS. THE 18Z TAFS REFLECT THIS TREND WITH VSBYS DROPPING TO 6SM. AFT 12Z/01 WINDS WILL EVENTUALLY BECOME SOUTHERLY BY LATE MORNING. ..08.. && .PREV DISCUSSION... /ISSUED 1104 AM CDT TUE JUL 31 2012/ UPDATE... A MINOR UPDATE TO THE FCST TO REFLECT CURRENT TRENDS HAS BEEN ISSUED. 15Z SFC OBS INDICATE THE FRONTAL BOUNDARY RUNS FROM CHICAGO TO ROUGHLY KSTJ. DEW POINTS HAVE POOLED INTO THE LOW AND MID 70S AROUND THE FRONT. RAP TRENDS SLOWLY PUSH THE BOUNDARY SOUTH OF THE CWFA DURING THE DAY SO DEW POINTS IN THE SOUTHERN PARTS OF THE CWFA SHOULD SLOWLY DROP DURING THE AFTERNOON. BASED ON THE 15Z OBS...MAX TEMPERATURES WERE ADJUSTED UPWARD SLIGHTLY. THERE IS VERY WEAK TO NEUTRAL CAA OCCURRING BEHIND THE FRONT BUT TEMPERATURES SHOULD STILL CLIMB THIS AFTERNOON. THE QUESTION THEN BECOMES WHAT IS THE POSSIBILITY OF CONVECTION THIS AFTERNOON. THERE IS A WEAK VORT MAX CURRENTLY MOVING FROM WISCONSIN INTO NORTHEAST ILLINOIS BUT NO APPARENT TRIGGER FOR LATER THIS AFTERNOON. THE CONVECTIVE TEMPERATURE ON THE 12Z SOUNDING WAS 93. HOWEVER...RAP TRENDS INDICATE CONVECTIVE TEMPERATURES CLIMBING ABOVE 100 FOR THE AFTERNOON HOURS. SO...SOME DIURNAL CLOUDS SHOULD BE SEEN ACROSS THE AREA THIS AFTERNOON BUT OVERALL DRY CONDITIONS SHOULD BE SEEN. THE ADJUSTMENT OF TEMPERATURES AND DEW POINTS FOR TODAY INDICATES THAT HEAT INDICES WILL BE IN THE 95 TO 100 DEGREE RANGE OVER ROUGHLY THE SOUTHERN 40 PERCENT OR SO OF THE CWFA. AN SPS WILL BE ISSUED TO BRING ATTENTION OF THE VERY WARM CONDITIONS EXPECTED FOR THE AFTERNOON HOURS. ..08.. PREV DISCUSSION... /ISSUED 620 AM CDT TUE JUL 31 2012/ AVIATION... A COLD FRONT EXTENDING ROUGHLY FROM CHICAGO TO MOLINE TO KANSAS CITY THIS MORNING WILL CONTINUE TO PUSH SLOWLY SOUTH ACROSS THE REGION. SURFACE AND LOW LEVEL WINDS WILL SHIFT TO THE NORTH BEHIND THE FRONT. AREAS OF MVFR FOG THAT HAVE DEVELOPED WHERE WINDS ARE CALM...MAINLY SOUTH OF HIGHWAY 34...WILL QUICKLY DISSIPATE WITHIN AN HOUR OR TWO OF SUNRISE. OTHERWISE...VFR CONDITIONS ARE EXPECTED TODAY AS SURFACE HIGH PRESSURE BUILDS INTO THE REGION. MVFR FOG WILL AGAIN BE POSSIBLE TONIGHT AS WINDS GO LIGHT AND COULD EVEN DROP INTO IFR CATEGORY IN AREAS THAT RECENTLY RECEIVED RAINFALL. /DMD/ PREV DISCUSSION... /ISSUED 309 AM CDT TUE JUL 31 2012/ SYNOPSIS... A COLD FRONT IS CROSSING THE CWFA THIS MORNING...STRETCHING FROM NEAR MILWAUKEE /KMKE/ TO SAVANNA /KSFY/ TO DES MOINES /KDSM/ AT 07Z. WITH THE SUPPORT OF AN UPPER SHORT WAVE...THE EASTERN PORTION OF THIS BOUNDARY OVER SOUTHERN WI AND NORTHERN IL HAS TRIGGERED CONVECTION. CONVECTION ALONG WESTERN PORTIONS OF THE FRONT IN OUR CWFA HAS BEEN LIMITED TO ISOLATED AND WEAK ELEVATED POST FRONTAL CELLS IN THE VICINITY OF THE 850MB FRONT. HOWEVER...DUE TO LIMITED MOISTURE SUPPORT OR CONVERGENCE THEY HAVE AMOUNTED TO VERY LITTLE AND CONTINUE TO WEAKEN AS WHAT MINIMAL UPPER SUPPORT WAS AVAILABLE QUICKLY SHIFTS EAST OUT OF THE REGION. SHORT TERM...TODAY AND TONIGHT... MAIN FORECAST FOCUS IN THE SHORT TERM IS POTENTIAL FOR LINGERING PRECIP CHANCES THIS MORNING THEN TEMPERATURES. SURFACE FRONT IS PROGGED TO DROP INTO SOUTHERN PORTIONS OF THE CWFA BY 15Z. AS MENTIONED ABOVE...WITH UPPER FORCING ALREADY RACING EAST OUT OF THE REGION...WILL KEEP LOW /ISOLATED/ POPS FOR NORTHEASTERN COUNTIES THROUGH 12Z THIS MORNING BUT NOTHING FOR TODAY. SURFACE RIDGE SETTLES INTO THE AREA THIS AFTERNOON AND OVERNIGHT. NAM AND UKMET ARE OUTLIERS...KEEPING THE SURFACE HIGH FARTHER NORTH THAN ALL OTHER MODEL SOLUTIONS. THUS HAVE BASED TEMP FORECASTS THROUGH TONIGHT ON THE FARTHER SOUTH SOLUTIONS...WITH LITTLE CHANGE IN TODAYS HIGH TEMP FORECAST FROM PREVIOUS UPDATES AND A SLIGHT LOWERING OF TONIGHTS LOW TEMP FORECAST. /DMD/ LONG TERM...WEDNESDAY THROUGH MONDAY... LOOKS LIKE AUGUST WILL START OUT JUST LIKE JULY...HOT. FORECAST FOCUS ON CONTINUED HOT TEMPERATURES REMAINDER OF THIS WEEK. THEN A VIGOROUS SYSTEM ARRIVES ON SATURDAY FOLLOWED BY A BRIEF COOL DOWN. WEDNESDAY THROUGH FRIDAY NIGHT...CONTINUED HOT THIS PERIOD WITH A SMALL CHANCE FOR THUNDERSTORMS THURSDAY INTO THURSDAY NIGHT AS A WEAK SHORT WAVE ARRIVES. MAX TEMPS WILL BE IN THE LOWER TO MID 90S WITH MIN TEMPS IN THE UPPER 60S TO MID 70S. SATURDAY AND SATURDAY NIGHT...ECM/GEM/GFS BRING A VIGOROUS TROUGH INTO THE MIDWEST THAT IS CURRENTLY LOCATED NEAR THE ALEUTIANS. STRONG MID LEVEL WINDS ARRIVING IN CONCERT WITH THE STRONG COLD FRONT MAY MAKE FOR AN ACTIVE SEVERE WEATHER DAY...IF THE TIMING IS RIGHT. THIS MAY ALSO PRODUCE A BETTER COVERAGE OF THUNDERSTORMS DUE TO THE STRENGTH OF THE SYSTEM. WILL HAVE MAX TEMPS IN THE UPPER 80S TO MID 90S BUT THIS WILL BE DETERMINED BY THE TIMING OF THE FRONT AND CLOUD TRENDS. SUNDAY AND MONDAY AND BEYOND...PASSAGE OF THE TROUGH AND COLD FRONT USHERS IN COOLER AND MUCH LESS HUMID AIR MASS...FOR SUNDAY AND MONDAY. MAX TEMPS IN THE 80S WITH LOWS IN THE 60S. HOWEVER THIS COOLER AIR IS ONLY BRIEF AS OPERATIONAL MODELS BUILD A RIDGE ALOFT BACK INTO THE MIDWEST FOR MUCH OF NEXT WEEK. 850 MB TEMPS WARM TO AT LEAST +25C FOR MUCH OF THE WEEK WHICH WOULD SUPPORT AFTERNOON TEMPS WELL INTO THE 90S TO LOWER 100`S AGAIN. THE LOCATION OF THE RIDGE BASED ON CURRENT MODEL DATA SUGGESTS THE MCS ACTIVITY WOULD BE ACROSS CENTRAL MN...NORTHERN WI AND NORTHERN LOWER MI. THIS PERSISTENT RIDGE LOOKS SIMILAR TO WHAT WE HAD DURING THE END OF JUNE AND FIRST WEEK IN JULY. HAASE && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1104 AM CDT TUE JUL 31 2012 .UPDATE... A MINOR UPDATE TO THE FCST TO REFLECT CURRENT TRENDS HAS BEEN ISSUED. 15Z SFC OBS INDICATE THE FRONTAL BOUNDARY RUNS FROM CHICAGO TO ROUGHLY KSTJ. DEW POINTS HAVE POOLED INTO THE LOW AND MID 70S AROUND THE FRONT. RAP TRENDS SLOWLY PUSH THE BOUNDARY SOUTH OF THE CWFA DURING THE DAY SO DEW POINTS IN THE SOUTHERN PARTS OF THE CWFA SHOULD SLOWLY DROP DURING THE AFTERNOON. BASED ON THE 15Z OBS...MAX TEMPERATURES WERE ADJUSTED UPWARD SLIGHTLY. THERE IS VERY WEAK TO NEUTRAL CAA OCCURRING BEHIND THE FRONT BUT TEMPERATURES SHOULD STILL CLIMB THIS AFTERNOON. THE QUESTION THEN BECOMES WHAT IS THE POSSIBILITY OF CONVECTION THIS AFTERNOON. THERE IS A WEAK VORT MAX CURRENTLY MOVING FROM WISCONSIN INTO NORTHEAST ILLINOIS BUT NO APPARENT TRIGGER FOR LATER THIS AFTERNOON. THE CONVECTIVE TEMPERATURE ON THE 12Z SOUNDING WAS 93. HOWEVER...RAP TRENDS INDICATE CONVECTIVE TEMPERATURES CLIMBING ABOVE 100 FOR THE AFTERNOON HOURS. SO...SOME DIURNAL CLOUDS SHOULD BE SEEN ACROSS THE AREA THIS AFTERNOON BUT OVERALL DRY CONDITIONS SHOULD BE SEEN. THE ADJUSTMENT OF TEMPERATURES AND DEW POINTS FOR TODAY INDICATES THAT HEAT INDICES WILL BE IN THE 95 TO 100 DEGREE RANGE OVER ROUGHLY THE SOUTHERN 40 PERCENT OR SO OF THE CWFA. AN SPS WILL BE ISSUED TO BRING ATTENTION OF THE VERY WARM CONDITIONS EXPECTED FOR THE AFTERNOON HOURS. ..08.. && .PREV DISCUSSION... /ISSUED 620 AM CDT TUE JUL 31 2012/ AVIATION... A COLD FRONT EXTENDING ROUGHLY FROM CHICAGO TO MOLINE TO KANSAS CITY THIS MORNING WILL CONTINUE TO PUSH SLOWLY SOUTH ACROSS THE REGION. SURFACE AND LOW LEVEL WINDS WILL SHIFT TO THE NORTH BEHIND THE FRONT. AREAS OF MVFR FOG THAT HAVE DEVELOPED WHERE WINDS ARE CALM...MAINLY SOUTH OF HIGHWAY 34...WILL QUICKLY DISSIPATE WITHIN AN HOUR OR TWO OF SUNRISE. OTHERWISE...VFR CONDITIONS ARE EXPECTED TODAY AS SURFACE HIGH PRESSURE BUILDS INTO THE REGION. MVFR FOG WILL AGAIN BE POSSIBLE TONIGHT AS WINDS GO LIGHT AND COULD EVEN DROP INTO IFR CATEGORY IN AREAS THAT RECENTLY RECEIVED RAINFALL. /DMD/ PREV DISCUSSION... /ISSUED 309 AM CDT TUE JUL 31 2012/ SYNOPSIS... A COLD FRONT IS CROSSING THE CWFA THIS MORNING...STRETCHING FROM NEAR MILWAUKEE /KMKE/ TO SAVANNA /KSFY/ TO DES MOINES /KDSM/ AT 07Z. WITH THE SUPPORT OF AN UPPER SHORT WAVE...THE EASTERN PORTION OF THIS BOUNDARY OVER SOUTHERN WI AND NORTHERN IL HAS TRIGGERED CONVECTION. CONVECTION ALONG WESTERN PORTIONS OF THE FRONT IN OUR CWFA HAS BEEN LIMITED TO ISOLATED AND WEAK ELEVATED POST FRONTAL CELLS IN THE VICINITY OF THE 850MB FRONT. HOWEVER...DUE TO LIMITED MOISTURE SUPPORT OR CONVERGENCE THEY HAVE AMOUNTED TO VERY LITTLE AND CONTINUE TO WEAKEN AS WHAT MINIMAL UPPER SUPPORT WAS AVAILABLE QUICKLY SHIFTS EAST OUT OF THE REGION. SHORT TERM...TODAY AND TONIGHT... MAIN FORECAST FOCUS IN THE SHORT TERM IS POTENTIAL FOR LINGERING PRECIP CHANCES THIS MORNING THEN TEMPERATURES. SURFACE FRONT IS PROGGED TO DROP INTO SOUTHERN PORTIONS OF THE CWFA BY 15Z. AS MENTIONED ABOVE...WITH UPPER FORCING ALREADY RACING EAST OUT OF THE REGION...WILL KEEP LOW /ISOLATED/ POPS FOR NORTHEASTERN COUNTIES THROUGH 12Z THIS MORNING BUT NOTHING FOR TODAY. SURFACE RIDGE SETTLES INTO THE AREA THIS AFTERNOON AND OVERNIGHT. NAM AND UKMET ARE OUTLIERS...KEEPING THE SURFACE HIGH FARTHER NORTH THAN ALL OTHER MODEL SOLUTIONS. THUS HAVE BASED TEMP FORECASTS THROUGH TONIGHT ON THE FARTHER SOUTH SOLUTIONS...WITH LITTLE CHANGE IN TODAYS HIGH TEMP FORECAST FROM PREVIOUS UPDATES AND A SLIGHT LOWERING OF TONIGHTS LOW TEMP FORECAST. /DMD/ LONG TERM...WEDNESDAY THROUGH MONDAY... LOOKS LIKE AUGUST WILL START OUT JUST LIKE JULY...HOT. FORECAST FOCUS ON CONTINUED HOT TEMPERATURES REMAINDER OF THIS WEEK. THEN A VIGOROUS SYSTEM ARRIVES ON SATURDAY FOLLOWED BY A BRIEF COOL DOWN. WEDNESDAY THROUGH FRIDAY NIGHT...CONTINUED HOT THIS PERIOD WITH A SMALL CHANCE FOR THUNDERSTORMS THURSDAY INTO THURSDAY NIGHT AS A WEAK SHORT WAVE ARRIVES. MAX TEMPS WILL BE IN THE LOWER TO MID 90S WITH MIN TEMPS IN THE UPPER 60S TO MID 70S. SATURDAY AND SATURDAY NIGHT...ECM/GEM/GFS BRING A VIGOROUS TROUGH INTO THE MIDWEST THAT IS CURRENTLY LOCATED NEAR THE ALEUTIANS. STRONG MID LEVEL WINDS ARRIVING IN CONCERT WITH THE STRONG COLD FRONT MAY MAKE FOR AN ACTIVE SEVERE WEATHER DAY...IF THE TIMING IS RIGHT. THIS MAY ALSO PRODUCE A BETTER COVERAGE OF THUNDERSTORMS DUE TO THE STRENGTH OF THE SYSTEM. WILL HAVE MAX TEMPS IN THE UPPER 80S TO MID 90S BUT THIS WILL BE DETERMINED BY THE TIMING OF THE FRONT AND CLOUD TRENDS. SUNDAY AND MONDAY AND BEYOND...PASSAGE OF THE TROUGH AND COLD FRONT USHERS IN COOLER AND MUCH LESS HUMID AIR MASS...FOR SUNDAY AND MONDAY. MAX TEMPS IN THE 80S WITH LOWS IN THE 60S. HOWEVER THIS COOLER AIR IS ONLY BRIEF AS OPERATIONAL MODELS BUILD A RIDGE ALOFT BACK INTO THE MIDWEST FOR MUCH OF NEXT WEEK. 850 MB TEMPS WARM TO AT LEAST +25C FOR MUCH OF THE WEEK WHICH WOULD SUPPORT AFTERNOON TEMPS WELL INTO THE 90S TO LOWER 100`S AGAIN. THE LOCATION OF THE RIDGE BASED ON CURRENT MODEL DATA SUGGESTS THE MCS ACTIVITY WOULD BE ACROSS CENTRAL MN...NORTHERN WI AND NORTHERN LOWER MI. THIS PERSISTENT RIDGE LOOKS SIMILAR TO WHAT WE HAD DURING THE END OF JUNE AND FIRST WEEK IN JULY. HAASE && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
809 PM MDT WED AUG 1 2012 .UPDATE... ISSUED AT 808 PM MDT WED AUG 1 2012 MODIFIED THE EVENING AND OVERNIGHT FORECAST SLIGHTLY MAINLY TO ACCOUNT FOR CURRENT CLOUD COVER AND PRECIPITATION COVERAGE AND TO BLEND INTO OVERNIGHT TRENDS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 225 PM MDT WED AUG 1 2012 THROUGH TONIGHT...CONVECTION IS ONCE AGAIN EXPECTED TO DEVELOP ACROSS THE PALMER DIVIDE REGION OF COLORADO WITH A GRADUAL SHIFT EASTWARD WITH TIME. HRRR IS ALSO DEVELOPING CONVECTION ACROSS NORTHWEST KANSAS BUT GIVEN LACK OF CU DEVELOPMENT OVER THIS AREA...CONFIDENCE IS BELOW AVERAGE IN THIS SOLUTION. HAVING SAID THAT...WILL MAINTAIN SLIGHT CHANCE POPS TO COVER THIS POTENTIAL. DID BUMP POPS UP SLIGHTLY FOR THE LATE EVENING TIME FRAME WHEN CONFIDENCE IS HIGHEST. TRENDED OVERNIGHT LOWS UP OVER THE EAST SIMILAR TO WHAT WAS OBSERVED THIS MORNING. OTHERWISE...LIGHT AND VARIABLE WINDS WITH A GRADUALLY CLEARING SKY ARE EXPECTED. THURSDAY...MAX TEMPS WILL BE SLIGHTLY COOLER AS COMPARED WITH TODAY WITH HIGHS IN MOST LOCATIONS REMAINING IN THE MID 90S TO AROUND 100 DEGREES. POTENTIAL EXISTS ONCE AGAIN FOR CONVECTION DEVELOPING DURING THE LATE AFTERNOON HOURS. GIVEN OBSERVED PWAT VALUES AROUND 135 PERCENT OF NORMAL...LOCALLY HEAVY RAINFALL WILL ONCE AGAIN BE A THREAT. GUSTY OUTFLOW WINDS ALSO APPEAR TO BE POSSIBLE BASED ON POINT SOUNDINGS FROM ACROSS THE AREA. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 225 PM MDT WED AUG 1 2012 THURSDAY NIGHT-SATURDAY...FAIRLY ACTIVE WEATHER WILL CONTINUE THROUGH THE PERIOD AS STRONG SHORT WAVE TROUGH DIVES INTO THE NORTHERN PLAINS...FORCING STRONG COLD FRONT INTO THE TRI STATE AREA FRIDAY NIGHT AND SATURDAY...BRINGING SOME RELIEF FROM THE HEAT TO THE AREA BY SATURDAY AFTERNOON. NOT REAL CONFIDENT IN PRECIPITATION CHANCES ON THURSDAY EVENING WITH MAIN STATIONARY FRONT WELL TO THE SOUTH OF THE AREA AND LOW LEVEL FLOW BEING LIGHT AND GENERALLY WESTERLY. HOWEVER...PERIOD OF LARGE SCALE ASCENT WILL MOVE JUST NORTH OF THE CWA AND IF THE MUCH WEAKER CINH PROFILE OF THE NAM VERIFIES...THAT MAY BE ENOUGH TO INITIATE AT LEAST A FEW STORMS ALONG SFC TROUGH THAT EXTENDS INTO WESTERN CWA. GIVEN ABOVE CONCERNS AND SREF DATA REALLY FOCUSING BEST CHANCES NEAR FRONT DO NOT THINK OVERALL PATTERN REALLY WARRANTS MORE THAN 15-20 PERCENT. THINK BEST CHANCES FOR PRECIPITATION WILL BE DURING THE OVERNIGHT HOURS ON FRIDAY AS STRONG COLD FRONT SWEEPS ACROSS THE AREA...WHICH WILL NOT ONLY BRING A PERIOD OF STRONG NEAR SFC ASCENT BUT A PERIOD OF DEEPER ASCENT DEEP DIRECT CIRCULATION EXPECTED TO DEVELOP BEHIND FRONT COLOCATED WITH AREA OF LARGE SCALE ASCENT AS PER Q VECTOR ANALYSIS. WHILE FORCING WILL LIKELY BE THE STRONGEST ITS BEEN OUT OF THE PAST SEVERAL DAYS...STILL A LARGE AMOUNT OF UNCERTAINTY WITH RESPECT TO HOW MUCH INSTABILITY WILL BE AHEAD AND BEHIND FRONTAL ZONE AS EVIDENCED BY LARGE DIFFERENCES BETWEEN GEFS AND SREF PROBABILISTIC OUTPUT...AND THINK FOR THE TIME BEING THINK KEEPING POPS BELOW 50 PERCENT WARRANTED ATTM. IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...WHILE 06Z ROUND OF ENSEMBLES SHOWED LITTLE SPREAD IN OVERALL PATTERN STARTING TO SEE A BIT MORE UNCERTAINTY DEVELOP WITH RESPECT TO STRENGTH OF H5 RIDGE EXPECTED TO DEVELOP OVER THE ROCKIES THROUGH THE MIDDLE OF NEXT WEEK. SOME ENSEMBLES SEEM TO BE CLUSTERING TOWARDS BOTH THE MORE AMPLIFIED GFS WITH THE OTHERS MORE IN THE ECMWF CAMP WHICH CERTAINLY LOWERS CONFIDENCE IN TRYING TO PICK ONE MODEL OVER THE OTHER. FOR THE TIME BEING...THINK CONSENSUS APPROACH THE BEST BET FOR HIGH TEMPS FOR THE TIME BEING. TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD...BUT WITH POSSIBILITY OF CWA BEING ON NORTHEAST SIDE OF A FAIRLY AMPLIFIED RIDGE POTENTIAL FOR COOLER AIR BACKING INTO THE AREA KEEPS CONFIDENCE TOO LOW TO MAKE LARGE DEVIATIONS FOR MAX TEMPS. FOR LOWS...WITH SFC HIGH SETTLING OVER THE AREA ON SAT NIGHT BEHIND STRONG COLD FRONT AND AT LEAST A FEW HOURS OF LIGHT WINDS AND MUCH DRIER AIR COULD SEE FAIRLY CHILLY LOWS ACROSS MUCH OF THE CWA WITH VALUES IN THE MID TO UPPER 50S. PRECIP CHANCES DO NOT LOOK PARTICULARLY GREAT THROUGH THE PERIOD BOTH DUE TO MORE STABLE AIR MOVING IN BEHIND THE FRONT AND THEN WITH STRONG RIDGE DEVELOPING NEAR THE AREA. LEFT A FEW AREAS SMALL CHANCES...ESPECIALLY ON SAT DUE TO FRONTAL TIMING CONCERNS AND AGAIN ON WEDNESDAY AS GEFS DATA BRINGING FAIRLY HIGH PROBABILITIES OF MEASURABLE PRECIP OVERNIGHT TUES INTO WED MORNING. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 608 PM MDT WED AUG 1 2012 VFR CONDITIONS ARE EXPECTED AGAIN THROUGH THE TAF PERIOD WITH AN AREA OF ISOLATED TO SCATTERED THUNDERSTORMS TO PASS OVER BOTH KMCK AND KGLD BETWEEN 02Z-06Z. GUSTY WIND AND CONDITIONS LOWERING TO LESS THAN VFR WILL ACCOMPANY THE STRONGER STORMS...BUT ARE NOT EXPECTED TO BE PREVAILING. ISOLATED THUNDERSTORMS ARE POSSIBLE AGAIN ACROSS THE CENTRAL HIGH PLAINS REGION AFTER 18Z ON THURSDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...LOCKHART SHORT TERM...FOLTZ LONG TERM...JRM AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS GOODLAND KS
613 PM MDT WED AUG 1 2012 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 225 PM MDT WED AUG 1 2012 THROUGH TONIGHT...CONVECTION IS ONCE AGAIN EXPECTED TO DEVELOP ACROSS THE PALMER DIVIDE REGION OF COLORADO WITH A GRADUAL SHIFT EASTWARD WITH TIME. HRRR IS ALSO DEVELOPING CONVECTION ACROSS NORTHWEST KANSAS BUT GIVEN LACK OF CU DEVELOPMENT OVER THIS AREA...CONFIDENCE IS BELOW AVERAGE IN THIS SOLUTION. HAVING SAID THAT...WILL MAINTAIN SLIGHT CHANCE POPS TO COVER THIS POTENTIAL. DID BUMP POPS UP SLIGHTLY FOR THE LATE EVENING TIME FRAME WHEN CONFIDENCE IS HIGHEST. TRENDED OVERNIGHT LOWS UP OVER THE EAST SIMILAR TO WHAT WAS OBSERVED THIS MORNING. OTHERWISE...LIGHT AND VARIABLE WINDS WITH A GRADUALLY CLEARING SKY ARE EXPECTED. THURSDAY...MAX TEMPS WILL BE SLIGHTLY COOLER AS COMPARED WITH TODAY WITH HIGHS IN MOST LOCATIONS REMAINING IN THE MID 90S TO AROUND 100 DEGREES. POTENTIAL EXISTS ONCE AGAIN FOR CONVECTION DEVELOPING DURING THE LATE AFTERNOON HOURS. GIVEN OBSERVED PWAT VALUES AROUND 135 PERCENT OF NORMAL...LOCALLY HEAVY RAINFALL WILL ONCE AGAIN BE A THREAT. GUSTY OUTFLOW WINDS ALSO APPEAR TO BE POSSIBLE BASED ON POINT SOUNDINGS FROM ACROSS THE AREA. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 225 PM MDT WED AUG 1 2012 THURSDAY NIGHT-SATURDAY...FAIRLY ACTIVE WEATHER WILL CONTINUE THROUGH THE PERIOD AS STRONG SHORT WAVE TROUGH DIVES INTO THE NORTHERN PLAINS...FORCING STRONG COLD FRONT INTO THE TRI STATE AREA FRIDAY NIGHT AND SATURDAY...BRINGING SOME RELIEF FROM THE HEAT TO THE AREA BY SATURDAY AFTERNOON. NOT REAL CONFIDENT IN PRECIPITATION CHANCES ON THURSDAY EVENING WITH MAIN STATIONARY FRONT WELL TO THE SOUTH OF THE AREA AND LOW LEVEL FLOW BEING LIGHT AND GENERALLY WESTERLY. HOWEVER...PERIOD OF LARGE SCALE ASCENT WILL MOVE JUST NORTH OF THE CWA AND IF THE MUCH WEAKER CINH PROFILE OF THE NAM VERIFIES...THAT MAY BE ENOUGH TO INITIATE AT LEAST A FEW STORMS ALONG SFC TROUGH THAT EXTENDS INTO WESTERN CWA. GIVEN ABOVE CONCERNS AND SREF DATA REALLY FOCUSING BEST CHANCES NEAR FRONT DO NOT THINK OVERALL PATTERN REALLY WARRANTS MORE THAN 15-20 PERCENT. THINK BEST CHANCES FOR PRECIPITATION WILL BE DURING THE OVERNIGHT HOURS ON FRIDAY AS STRONG COLD FRONT SWEEPS ACROSS THE AREA...WHICH WILL NOT ONLY BRING A PERIOD OF STRONG NEAR SFC ASCENT BUT A PERIOD OF DEEPER ASCENT DEEP DIRECT CIRCULATION EXPECTED TO DEVELOP BEHIND FRONT COLOCATED WITH AREA OF LARGE SCALE ASCENT AS PER Q VECTOR ANALYSIS. WHILE FORCING WILL LIKELY BE THE STRONGEST ITS BEEN OUT OF THE PAST SEVERAL DAYS...STILL A LARGE AMOUNT OF UNCERTAINTY WITH RESPECT TO HOW MUCH INSTABILITY WILL BE AHEAD AND BEHIND FRONTAL ZONE AS EVIDENCED BY LARGE DIFFERENCES BETWEEN GEFS AND SREF PROBABILISTIC OUTPUT...AND THINK FOR THE TIME BEING THINK KEEPING POPS BELOW 50 PERCENT WARRANTED ATTM. IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...WHILE 06Z ROUND OF ENSEMBLES SHOWED LITTLE SPREAD IN OVERALL PATTERN STARTING TO SEE A BIT MORE UNCERTAINTY DEVELOP WITH RESPECT TO STRENGTH OF H5 RIDGE EXPECTED TO DEVELOP OVER THE ROCKIES THROUGH THE MIDDLE OF NEXT WEEK. SOME ENSEMBLES SEEM TO BE CLUSTERING TOWARDS BOTH THE MORE AMPLIFIED GFS WITH THE OTHERS MORE IN THE ECMWF CAMP WHICH CERTAINLY LOWERS CONFIDENCE IN TRYING TO PICK ONE MODEL OVER THE OTHER. FOR THE TIME BEING...THINK CONSENSUS APPROACH THE BEST BET FOR HIGH TEMPS FOR THE TIME BEING. TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD...BUT WITH POSSIBILITY OF CWA BEING ON NORTHEAST SIDE OF A FAIRLY AMPLIFIED RIDGE POTENTIAL FOR COOLER AIR BACKING INTO THE AREA KEEPS CONFIDENCE TOO LOW TO MAKE LARGE DEVIATIONS FOR MAX TEMPS. FOR LOWS...WITH SFC HIGH SETTLING OVER THE AREA ON SAT NIGHT BEHIND STRONG COLD FRONT AND AT LEAST A FEW HOURS OF LIGHT WINDS AND MUCH DRIER AIR COULD SEE FAIRLY CHILLY LOWS ACROSS MUCH OF THE CWA WITH VALUES IN THE MID TO UPPER 50S. PRECIP CHANCES DO NOT LOOK PARTICULARLY GREAT THROUGH THE PERIOD BOTH DUE TO MORE STABLE AIR MOVING IN BEHIND THE FRONT AND THEN WITH STRONG RIDGE DEVELOPING NEAR THE AREA. LEFT A FEW AREAS SMALL CHANCES...ESPECIALLY ON SAT DUE TO FRONTAL TIMING CONCERNS AND AGAIN ON WEDNESDAY AS GEFS DATA BRINGING FAIRLY HIGH PROBABILITIES OF MEASURABLE PRECIP OVERNIGHT TUES INTO WED MORNING. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 608 PM MDT WED AUG 1 2012 VFR CONDITIONS ARE EXPECTED AGAIN THROUGH THE TAF PERIOD WITH AN AREA OF ISOLATED TO SCATTERED THUNDERSTORMS TO PASS OVER BOTH KMCK AND KGLD BETWEEN 02Z-06Z. GUSTY WIND AND CONDITIONS LOWERING TO LESS THAN VFR WILL ACCOMPANY THE STRONGER STORMS...BUT ARE NOT EXPECTED TO BE PREVAILING. ISOLATED THUNDERSTORMS ARE POSSIBLE AGAIN ACROSS THE CENTRAL HIGH PLAINS REGION AFTER 18Z ON THURSDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...FOLTZ LONG TERM...JRM AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS GOODLAND KS
226 PM MDT TUE JUL 31 2012 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 226 PM MDT TUE JUL 31 2012 15Z WATER VAPOR IMAGERY AND RAP ANALYSIS INDICATED LARGE ANTICYCLONIC CIRCULATION ALOFT IN PLACE ACROSS THE SOUTHERN PLAINS WITH CWA ON NORTHERN PERIPHERY OF CIRCULATION...WITH ANOTHER SHORT WAVE TROUGH NOTED UPSTREAM ALONG THE UTAH AND COLORADO BORDER. 12Z RAOBS INDICATED LITTLE CHANGE OVER THE PAST 24 HOURS ASIDE FROM SOME LOW LEVEL DRYING AT LBF...WITH STEEP LAPSE RATES STILL OBSERVED MAINLY BETWEEN H7 AND H6 AT BOTH DDC AND DNR. MAIN SHORT TERM ISSUE WILL BE PRECIPITATION CHANCES LATE THIS AFTERNOON AND EVENING. TONIGHT...OVERALL PATTERN HAS CHANGED LITTLE FROM YESTERDAY WITH LARGE SCALE RIDGE REMAINING TO THE SOUTH OF THE AREA AND SHORT WAVE TROUGH MOVING OVER THE TOP OF THE RIDGE TONIGHT. OVERALL INSTABILITY AND PW PROFILES SIMILAR AS WELL...WITH ONLY LOW LEVEL SHEAR BEING NOTICEABLY WEAKER THAN YESTERDAY. WITH CU FIELDS DEVELOPING OVER THE HIGHER TERRAIN AND NEAR MESOLOW NOTED OVER YUMA COUNTY...FAIRLY LARGE LCLS IN PLACE FAVORING STRONG COLD POOLS AND MCS VECTORS FAVORING EASTWARD MOTION INTO STRONGER INSTABILITY ACROSS THE CWA THINK CHANCES FOR ANOTHER ROUND OF PRECIPITATION FAIRLY GOOD ACROSS MUCH OF THE CWA...BUT UNTIL SOME ECHOES BEGIN TO DEVELOP DOWNSTREAM AM HESITANT TO GO MUCH ABOVE THE 40-50% RANGE FOR POPS ATTM. BEST TIMING FOR PRECIP LOOKS TO BE IN THE 00-04Z RANGE...BUT WITH LINGERING WAA THROUGH THE NIGHT THINK AT LEAST A FEW WEAK SHOWERS WILL CONTINUE THROUGH THE EARLY MORNING HOURS. TEMPERATURES SHOULD BE FAIRLY SIMILAR TO WHAT OCCURRED LAST NIGHT WITH WET BULB TEMPS WITH THUNDERSTORMS LIKELY BRINGING TEMPS DOWN INTO THE 60S AS STORMS PASS RESULTING IN AT LEAST FEW LOCATIONS SEEING LOW TEMPS OCCURRING EARLIER THAN NORMAL. WITH HIGH PRECIPITABLE WATERS AND DEEP WARM CLOUD LAYER/FREEZING LEVEL AROUND 17 KFT MSL...HEAVY RAIN WILL BE A THREAT BUT THINK OVERALL MCS MOTION WILL BE FAST ENOUGH TO LIMIT ANY WIDESPREAD FLASH FLOOD THREAT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 226 PM MDT TUE JUL 31 2012 H5 RIDGE WILL BEGIN TO FLATTEN WITH WESTERLY ZONAL FLOW DEVELOPING OVER THE NORTHERN PLAINS. THIS WILL ALLOW FOR A SERIES OF STRONGER SHORTWAVE TROUGHS TO MOVE THROUGH THE NORTHERN PLAINS...AND ASSOCIATED COLD FRONTS TO DROP SOUTH TOWARDS THE CWA. THE FIRST OF THESE FRONT WILL ARRIVE LATE WEDNESDAY EVENING. INSTABILITY AND MOISTURE WILL REMAIN IN PLACE THROUGH THE DAY WEDNESDAY...WITH INITIATION DURING THE AFTERNOON FOLLOWING SIMILAR PATTERN AS THE LAST FEW NIGHTS IN THE WEST/NORTHWEST. ISOLATED ACTIVITY SHOULD INCREASE IN COVERAGE DURING THE EVENING HOURS AS THUNDERSTORMS BECOME MORE ORGANIZED UNDER WEAK FLOW. DIFFERENCE WILL BE WITH LARGE SCALE ASSOCIATED WITH COLD FRONT IN THE EVENING HOURS...WHICH COULD HELP WITH COVERAGE/STRENGTH OF THUNDERSTORMS. SOUNDINGS APPEAR TO BE DRIER THAN THE LAST FEW DAYS...HOWEVER PWAT VALUES OVER 1 INCH ARE STILL BEING ADVERTISED. DEPENDING ON THE TIMING OF THE FRONT POSITION OF THE BEST THUNDERSTORM COVERAGE COULD BE PUSHED TO THE SOUTH AND EAST QUICKER THAN CURRENTLY ADVERTISED...SO I WAS NOT CONFIDENT ENOUGH TO GO HIGHER THAN 40 POPS DURING THE EVENING. WEAK SHORTWAVE TROUGHS WILL CONTINUE TO MOVE NORTH OF THE CWA ON THURSDAY...HOWEVER WITH POST FRONTAL AIRMASS IN PLACE I HAVE QUESTIONS TO HOW MUCH SURFACE BASE AND MIXED LAYER CAPE WILL BE AROUND TO INITIATE THUNDERSTORMS. FOR NOW I HAVE KEPT POPS LIMITED TO 20 RANGE THU/THU NIGHT. BETTER CHANCES RETURN FRIDAY NIGHT WHEN A STRONGER TROUGH MOVES THROUGH THE NORTHERN PLAINS AND ANOTHER COLD FRONT DROPS SOUTH ACROSS THE CWA. HAVE INCREASED POPS TO CHANCE CATEGORY. GUIDANCE CONTINUES TO SHOW CHANCES LINGERING THROUGH SATURDAY NIGHT AS ADDITIONAL WEAKER SHORTWAVES MOVE THROUGH THE AREA ON NORTHERN EXTENT OF RIDGE. CONFIDENCE IS LOWER ON THIS ACTIVITY...SO I LIMITED IT TO SLIGHT CHANCE. TEMPERATURES ON WEDNESDAY AND THURSDAY SHOULD BE AROUND OR ABOVE 100F WITH GOOD WAA AHEAD OF APPROACHING COLD FRONTS. BEHIND THE FRONT ON THURSDAY AFTERNOON TEMPS WILL BE IN THE MID TO UPPER 90S...WITH NEAR NORMAL TEMPERATURES ON SATURDAY IN THE UPPER 80S/LOW 90S. THE H5 RIDGE WILL BEGIN TO BUILD NORTH AGAIN AND STRENGTHEN SUNDAY INTO EARLY NEXT WEEK AND BRING US BACK TO 100 DEGREE TEMPERATURES AND A DRIER PATTERN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1144 AM MDT TUE JUL 31 2012 MAIN CONCERN WILL ONCE AGAIN BE THUNDERSTORM CHANCES AS OVERALL SIMILAR PATTERN REMAINS ACROSS THE TRI STATE AREA AS YESTERDAY. GIVEN EXPECTED VERTICAL PROFILES...A PERIOD OF REDUCED VISIBILITY IN HEAVY RAIN AND STRONG WIND GUSTS WILL ACCOMPANY ANY STORM THAT FORMS. FOR THE TIME BEING...THINK TIMING WILL BE SIMILAR TO LAST NIGHT WITH GLD BEING THE MOST LIKELY SITE TO BE IMPACTED...ALTHOUGH CHANCES WILL BE A BIT HIGHER THAN YESTERDAY AT MCK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...DR AVIATION...JRM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1247 AM CDT TUE JUL 31 2012 ...UPDATED FOR AVIATION SECTION... .SYNOPSIS... ISSUED AT 1158 AM CDT MON JUL 30 2012 AN UPPER LEVEL HIGH CONTINUED TO GRIP THE CENTRAL AND SOUTHERN GREAT PLAINS. THE CENTER OF THE HIGH AT 500MB WAS LOCATED ACROSS THE SOUTHERN TEXAS PANHANDLE PER RAOB AND RAP ANALYSIS AS OF 30.12Z. AN ARC OF MID LEVEL MOISTURE COULD BE SEEN ON WATER VAPOR LOOP AND RAOB ANALYSIS FROM WESTERN/CENTRAL ARIZONA THROUGH UTAH AND NORTHEAST TO SOUTHEASTERN WYOMING AND WESTERN NEBRASKA. ALL ALONG THIS MOISTURE ARC...THERE WERE MINOR MID LEVEL PERTURBATIONS IN THE FLOW PATTERN DUE TO LATENT HEAT RELEASE FROM VARIOUS THUNDERSTORM CLUSTERS. A MESOSCALE CONVECTIVE SYSTEM MOVED ACROSS SOUTHERN NEBRASKA/NORTHERN KANSAS DURING THE OVERNIGHT HOURS WITH THE MID LEVEL POTENTIAL VORTICITY ANOMALY TIED TO THIS MCS MOVING INTO EASTERN KS/WESTERN MO. ADDITIONAL MID LEVEL VORTICITY COULD BE SEEN IN THE RAP ANALYSIS MOVING INTO NORTHERN COLORADO WITH A 30-40 KNOT 400MB SPEED MAX ROTATING NORTH-NORTHEASTWARD INTO THE COLORADO ROCKIES. IN THE LOWER TROPOSPHERE...A STATIONARY FRONT EXTENDED FROM ROUGHLY BEAVER, OK TO BUCKLIN, KS TO NEAR PRATT, KS AT 16Z. OKLAHOMA MESONET OBSERVATIONS AT 1650Z REVEALED AN AXIS OF 102 TO 104F TEMPERATURES ACROSS WEST-CENTRAL OKLAHOMA ON WEST-SOUTHWEST SURFACE WINDS SOUTH OF THIS BOUNDARY. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 244 PM CDT MON JUL 30 2012 WITH THE AFTERNOON FORECAST UPDATE...WILL LOWER THE POPS DOWN TO 10-14 PERCENT FOR AREAS ALONG THE STATIONARY FRONT AS CONVERGENCE ALONG THE FRONT IS QUITE WEAK AND THERE HAS BEEN A LACK OF CUMULUS DEVELOPMENT THROUGH 1930Z. IF ANYTHING DOES DEVELOP...THE COVERAGE WILL BE VERY ISOLATED AND ANY INDIVIDUAL STORM WILL BE SMALL. WILL BE TURNING THE ATTENTION TO THE WEST LATER ON THIS EVENING AND DURING THE OVERNIGHT HOURS AS AN MCS MAY DEVELOP IN THE POST-FRONTAL LIGHT UPSLOPE WINDS WITH DEWPOINTS IN THE MID TO UPPER 50S ACROSS EAST-CENTRAL COLORADO AND WEST-CENTRAL/SOUTHWEST KANSAS ALONG AND NORTH OF THE FRONT. VARIOUS HIGH-RESOLUTION CONVECTION-ALLOWING MODELS SUGGEST HIGHER TERRAIN STORMS WILL MANAGE TO HOLD TOGETHER TO THE KANSAS STATE BORDER...SO WILL HAVE 30 POPS GOING ACROSS THE WESTERN COUNTIES AND 20 POPS AS FAR EAST AS ROUGHLY HIGHWAY 83. LATE TONIGHT INTO TOMORROW...THE CONVECTIVE OUTFLOW FROM WHATEVER REMAINS OF THE MCS TONIGHT WILL PUSH THE STATIONARY FRONT FARTHER SOUTH THAN WHERE IT IS NOW WITH A WEAK WAVE DEVELOPING ALONG THE FRONT ACROSS SOUTH-CENTRAL KS BY DAYBREAK TUESDAY. WEST OF THE WAVE...WINDS AT THE SURFACE WILL LIKELY BE MORE NORTHERLY ACROSS MUCH OF THE DDC FORECAST AREA. TOMORROW`S FORECAST HIGH TEMPERATURE HAS BEEN LOWERED TO MID-UPPER 90S FROM HAYS TO CIMARRON TO HUGOTON AND POINTS WEST TO THE COLORADO BORDER. EVEN THE AREAS ACROSS SOUTH CENTRAL KANSAS WILL BE SLIGHTLY NORTH OF THE FRONT MORE THAN LIKELY AND HAVE LOWERED THE HIGHS IN MEDICINE LODGE AREA DOWN TO ABOUT 103-104F (WHICH MAY STILL BE A BIT TOO WARM IF THE FRONT ENDS UP BEING JUST SOUTH OF THERE). AS FAR AS THUNDERSTORM POTENTIAL GOES TOMORROW...IT WILL BE VERY SIMILAR TO TODAY...WITH THE GENERAL THINKING BEING THAT ANYTHING THAT WOULD DEVELOP ALONG THE FRONT WOULD BE VERY ISOLATED IN NATURE WITH THE MOST COHERENT CONVECTION FORMING ONCE AGAIN OVER EASTERN COLORADO. WILL BE KEEPING POPS BELOW 15 EXCEPT NEAR THE COLORADO BORDER FOR LATE IN THE AFTERNOON TUESDAY AS A RESULT. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 336 PM CDT MON JUL 30 2012 AN UPPER LEVEL RIDGE WILL REMAIN ACROSS THE SOUTHERN PLAINS WEDNESDAY AND THURSDAY, WITH WESTERN KANSAS LOCATED ALONG THE SOUTHERN EDGE OF THE WESTERLIES NEAR A QUASI-STATIONARY SURFACE FRONT. ORDINARILY THIS KIND OF PATTERN COULD RESULT IN ISOLATED THUNDERSTORMS. BUT THIS YEAR THE LOW-LEVEL MOISTURE IS JUST VERY LIMITED. NEVERTHELESS, ISOLATED THUNDERSTORMS CANNOT BE RULED OUT EITHER DAY. TEMPERATURES WILL CONTINUE TO BE HOT, ESPECIALLY SOUTH OF THE FRONT OVER SOUTH CENTRAL AND PARTS OF SOUTHWEST KANSAS TO THE SOUTH OF THE FRONT. ALTHOUGH THERE ARE SLIGHT DIFFERENCES IN MODEL TIMING, A STRONG SHORTWAVE TROUGH IS ADVERTISED TO DIG INTO THE NORTHERN ROCKIES FRIDAY AND THEN PASS ACROSS THE NORTHERN PLAINS BY SATURDAY. AN OLD FRONT WILL STILL BE STALLED OUT ACROSS SOUTHWEST KANSAS, AND A REINFORCING COLD FRONT WILL APPROACH KANSAS WITH THE NORTHERN STREAM SYSTEM BY SATURDAY OR SATURDAY NIGHT. THERE WILL BE ADDITIONAL SMALL CHANCES FOR THUNDERSTORMS EACH DAY, WITH THE EXACT LOCATION DEPENDING ON WHERE THE FRONTAL BOUNDARIES ARE. IT WILL STILL BE HOT, ESPECIALLY SOUTH OF THE FRONTS OVER SOUTH CENTRAL KANSAS, WITH HIGHS ABOVE 105F FOR BOTH FRIDAY AND SATURDAY. SLIGHTLY COOLER TEMPERATURES CAN BE EXPECTED IN WEST CENTRAL KANSAS. SLIGHTLY COOLER TEMPERATURES ARE EXPECTED BY SUNDAY AND MONDAY ACROSS MOST OF SOUTHWEST KANSAS AFTER THE AFOREMENTIONED SHORTWAVE TROUGH PUSHES A COLD FRONT THROUGH KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1239 AM CDT TUE JUL 31 2012 A DYING CONVECTIVE SYSTEM MOVING OUT OF NORTHWEST KANSAS WAS MOVING EAST AND SHOULD STAY NORTH OF THE FORECAST AREA FOR THE EARLY MORNING HOURS. HOWEVER THERE WERE ADDITIONAL SHOWERS AND DEVELOPING THUNDERSTORMS IN SOUTHEAST COLORADO. THERE IS SOME HINT THAT THIS ACTIVITY COULD SNEAK INTO OUR WESTERN COUNTIES. BUT IT DOES NOT APPEAR LIKELY THAT CONVECTION WOULD REACH THE AVIATION TERMINAL LOCATIONS. THE WIND SHIFT ASSOCIATED WITH THE NORTHWEST KANSAS ACTIVITY WILL MOVE ACROSS THE AREA BUT ONLY WILL PRODUCE A FEW WIND GUSTS TO 22 KT AT THE GREATEST. && .PRELIMINARY POINT TEMPS/POPS... DDC 75 104 76 106 / 20 10 20 10 GCK 73 103 73 104 / 20 20 20 10 EHA 73 103 74 104 / 20 20 20 10 LBL 74 104 74 105 / 20 10 20 10 HYS 75 103 76 102 / 20 10 20 20 P28 78 108 78 109 / 10 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...UMSCHEID SHORT TERM...UMSCHEID LONG TERM...FINCH AVIATION...HUTTON
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
152 PM EDT TUE JUL 31 2012 .UPDATE... ISSUED AT 150 PM EDT TUE JUL 31 2012 A FEW ISOLATED SHOWERS AND EVEN A THUNDERSTORM IN FLOYD COUNTY HAVE DEVELOPED OVER THE PAST HOUR OR SO. SFC BASED CAPE IS HIGHEST IN THE BIG SANDY REGION PER SPC MESOANALYSIS WITH LOW LEVEL LAPSE RATES RATHER STEEP NO REAL INHIBITION. HOWEVER TRIGGERS ARE A BIT SUBTLE. THIS SAME ANALYSIS DOES INDICATE SOME COOLING OCCURRING NEAR 500 MB FROM A WEAK SHORTWAVE. MID LEVEL LAPSE RATES ARE GREATER TO THE NW OF CURRENT CONVECTION CLOSER TO COLD POCKET ALOFT. THE OUTFLOW BOUNDARY FROM CONVECTION EARLIER THIS AM LIES NW OF THE BLUEGRASS COUNTIES. AS WE APPROACH PEAK HEATING...EXPECTED ISOLATES SHRA/TSRA TO DEVELOP...WITH INSTABILITY PARAMETERS FAVORING THE SE COUNTIES OVER THE NEXT COUPLE OF HOURS. THE OUTFLOW NW OF THE REGION MAY EITHER REACH THE BLUEGRASS COUNTIES BY LATE IN THE AFTERNOON OR POSSIBLY LEAD TO CONVECTIVE DEVELOPMENT THERE THAT COULD SENDS OUTFLOWS OUR WAY. THE MOST RECENT HRRR SEEMS REASONABLE AND GENERALLY POINTS TOWARD THE AFTERNOON ACTIVITY GENERALLY IN THE SE WITH THIS TENDING TO DIE OFF IN THE EVENING WITH CONVECTION THEN POSSIBLE IN THE BLUEGRASS. THIS SCENARIO IS GENERALLY IN LINE WITH THE PREVIOUS GRIDS...SO ONLY SOME MINOR POP AND HOURLY GRIDS WERE TRENDED BASED ON RECENT OBS. UPDATE ISSUED AT 1018 AM EDT TUE JUL 31 2012 THE UPPER LEVEL DISTURBANCE THAT BROUGHT CONVECTION TO MAINLY THE SW CWA CONTINUES TO DEPART FROM THE REGION WITH PERHAPS A FEW SPRINKLES OR VERY LIGHT SHOWERS LEFT BEHIND IN THE SOUTHEAST. MEANWHILE...ANOTHER UPPER LEVEL DISTURBANCE MOVING THROUGH THE GREAT LAKES WILL GENERALLY PASS NORTH OF THE REGION TODAY...BUT WILL SEND A COLD FRONT TOWARD THE REGION BY THE EVENING. MEANWHILE A RATHER WELL DEFINED OUTFLOW BOUNDARY FROM SW INDIANA TO NEAR A CVG TO ILN TO CMH LINE IS EVIDENT ON VIS SAT AND RADAR IMAGERY. ALTHOUGH CONVECTION HAS NOT RECENTLY DEVELOPED ALONG THIS...THE 12Z NAM AND 6Z MODEL RUN DID NOT HANDLE CONVECTION OVER EAST CENTRAL IL AND WEST CENTRAL IN ALL THAT WELL. THIS LEADS TO UNCERTAINTY IN CONVECTIVE DEVELOPMENT THIS AFTERNOON...BUT LEFTOVER BOUNDARIES...ARES OF DIFFERENTIAL HEATING BETWEEN CLOUDY AND LESS CLOUDY AREAS THIS MORNING THROUGH EARLY THIS AFTERNOON AS WELL AS THE APPROACHING OUTFLOW FROM THE NW MAY BE A FOCUS FOR CONVECTIVE DEVELOPMENT IN THE AFTERNOON...GENERALLY FROM 18Z ON DURING PEAK HEATING. SKY COVER AND POPS WERE ADJUSTED A BIT IN THE NW AND THE SE TO ACCOUNT FOR THE APPROACHING OUTFLOW BOUNDARY AND RADAR TRENDS IN THE SE CWA. HOURLY TEMP AND DEWPOINT GRIDS WERE ALSO FRESHENED UP BASED ON RECENT OBS. UPDATE ISSUED AT 745 AM EDT TUE JUL 31 2012 DID A QUICK UPDATE FOR CURRENT CONDITIONS AND TRENDS. THE MAIN CHANGE ENTAILS A FINE TUNING OF THE NEAR TERM POPS...SKY AND WX TO ACCOUNT FOR THE ONGOING ISOLATED CONVECTION IN THE FAR SOUTH. UPDATES HAVE BEEN SENT. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 315 AM EDT TUE JUL 31 2012 06Z SFC ANALYSIS SHOWS A DIFFUSE SURFACE PATTERN THROUGH EAST KENTUCKY WITH SLIGHTLY LOWER PRESSURE FOUND TO THE SOUTHWEST WHERE A BATCH OF SHOWERS AND OCCASIONAL THUNDERSTORMS ARE DROPPING INTO THE TENNESSEE VALLEY. THESE ARE ASSOCIATED WITH THE LATEST SHORTWAVE TO MOVE THROUGH THE REGION IN THE NORTHWEST FLOW ON THE EASTERN EDGE OF THE SOUTHWEST RIDGE. IN ADDITION...OF NOTE...A BAND OF THUNDERSTORMS ARE CURRENTLY CROSSING THE GREAT LAKES ALSO IN CONJUNCTION WITH A SHORTWAVE...THOUGH A STRONGER ONE. THE CONVECTION AND ITS CLOUDS WILL CONTINUE TO AFFECT THE SOUTHWEST PORTION OF THE AREA THROUGH THE REMAINDER OF THE MORNING. TO THE NORTHEAST...MORE CLEAR SKIES ARE FOUND AND THIS HAS BEEN PROMOTING DECENT RADIATIONAL COOLING WITH A RIDGE TO VALLEY TEMPERATURE SPLIT ON THE ORDER OF 10 DEGREES UNDER WAY. WITH LOW DEWPOINT DEPRESSIONS IN THE VALLEYS...DO ANTICIPATE SOME FOG FORMING THERE TOWARDS DAWN. THE MODELS ARE IN DECENT AGREEMENT ALOFT REPRESENTING THE EVOLUTION OF THE MID LEVEL PATTERN THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL HAVE THE PERSISTENT RIDGE CENTERED OVER NORTHERN TEXAS AND TROUGHING THROUGH THE NORTHEAST UNITED STATES. THIS WILL MAINTAIN NORTHWEST FLOW OVER KENTUCKY ALONG WITH A STEADY STREAM OF...MOSTLY WEAK...SHORTWAVES PASSING THROUGH THE OHIO VALLEY AND SOUTHERN APPALACHIANS. THE MAIN WAVE...WITHIN THE BROADER TROUGH... WILL SLOWLY DROP THROUGH THE GREAT LAKES EARLY THIS MORNING...MOVE THROUGH THE OHIO VALLEY TODAY...AND PASS OVER THE SPINE OF THE APPALACHIANS LATER TONIGHT WITH HEIGHTS SLIGHTLY RISING IN ITS WAKE...ON WEDNESDAY. THE NAM IS MOST ROBUST WITH THIS FEATURE WHILE THE OTHER MODELS ARE IN BETTER AGREEMENT ON A MORE SUBTLE PASSAGE. EITHER WAY...THIS WAVE/TROUGH AXIS IS THE MOST SIGNIFICANT UPPER LEVEL FEATURE IMPACTING EAST KENTUCKY THROUGH THE SHORT TERM. HAVE FOLLOWED A BLEND OF THE MODEL GUIDANCE WITH A LEAN TOWARD A MODIFIED VERSION...PRIMARILY WEAKER AND MORE BROAD BRUSHED...NAM12 GIVEN THE NATURE OF THE MESOSCALE TO DOMINATE IN THIS TYPE OF SUMMER PATTERN. SENSIBLE WEATHER WILL FEATURE THE CURRENT AREA OF CONVECTION GRADUALLY DEPARTING TO THE SOUTH THIS MORNING...BUT LIKELY LEAVING BEHIND SOME BOUNDARIES THAT THE DAILY INSTABILITY MAY BE ABLE TO TAKE ADVANTAGE OF FOR ADDITIONAL CONVECTION LATER IN THE DAY. ATTENTION WILL THEN TURN TO THE REMNANTS OF THE FRONT CURRENTLY CROSSING THE GREAT LAKES AND ITS ARRIVAL INTO OUR VICINITY TOWARD EVENING. THIS WILL HAVE THE POTENTIAL FOR ANOTHER BATCH OF CONVECTION WITH IT AS IT PASSES TONIGHT...BUT IT WILL NOT BE CROSSING AT THE BEST TIMES FOR GOOD INSTABILITY SO UNCERTAINTY OVER THE ACTUAL MAGNITUDE AND PLACEMENT OF ANY RE/DEVELOPMENT TONIGHT REMAINS HIGH. THE TROUGHING TO THE EAST WILL CONTINUE A BETTER RISK FOR CONVECTION INTO THE DAY WEDNESDAY IN THE EASTERN PARTS OF THE CWA...WHILE SOMEWHAT DRIER... BUT NOT COOLER...AIR MOVES INTO OUR WESTERN ZONES. FOR THE MOST PART THE AREA WILL BE RATHER HUMID AND VERY WARM AGAIN TODAY AND WEDNESDAY WITH THE COOLING EFFECT OF ANY CONVECTION...MCS OR OTHERWISE...RATHER LIMITED. FOR TEMPERATURES...FOLLOWED A BLEND OF PERSISTENCE...THE EXISTING GRIDS AND THE MET MOS THROUGH THE SHORT TERM WITH ADJUSTMENTS FOR TERRAIN EFFECTS TONIGHT. AS FOR POPS...ENDED UP MOST SIMILAR TO THE MET NUMBERS THROUGH THE PERIOD. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 310 AM EDT TUE JUL 31 2012 MODELS CONTINUE TO COME INTO RELATIVELY GOOD ALIGNMENT WITH THE EVOLUTION OF THE PATTERN THROUGH THE LONG TERM. THE PERIOD LOOKS TO BEGIN WITH A SLOWLY DEPARTING TROF OVER THE NERN CONUS WHILE SFC HIGH PRESSURE AND RIDGING ALOFT REMAIN THE DOMINANT FEATURES OVER THE PLAINS. THIS SETUP WILL LEAVE ERN KY UNDER A NW FLOW THROUGH MUCH OF THE WORK WEEK HOWEVER...GIVEN THE LIMITED MOISTURE BEING ADVERTISED IN THE MODELS...WILL CONTINUE TO KEEP THE FCST DRY THROUGH THURSDAY NIGHT. BY FRIDAY...RETURN FLOW LOOKS TO COMMENCE AS HIGH PRESSURE STRENGTHENS OVER THE WRN ATLANTIC AND AN AREA OF LOW PRESSURE BEGINS WINDING UP OVER THE PLAINS. THE MID AND UPPER LEVELS ARE EXPECTED TO BE TRANSITIONING INTO MORE OF A ZONAL FLOW OVER THE NRN HALF OF THE CONUS LEAVING THE OHIO VALLEY STILL REPLETE WITH SHORT WAVE ENERGY SKIRTING THE AREA ON FRIDAY AND SATURDAY...THUS RETURNING ERN KY TO OUR REGULARLY SCHEDULED AFTERNOON/EVENING CHANCES FOR SHOWERS AND THUNDERSTORMS. ABOUT THIS TIME...ANOTHER ALBERTA CLIPPER LOOKS TO BEGIN RACING ACROSS THE U.S./CANADIAN BORDER...USHERING A SFC SYSTEM THROUGH THE GREAT LAKES OVER THE WEEKEND. THE ASSOCIATED COLD FRONT LOOKS TO BEGIN APPROACHING OUR NECK OF THE WOODS AROUND THE TAIL END OF THE PERIOD AND WITH A GOOD CONSENSUS EVEN THIS FAR OUT...WILL CONTINUE WITH GOOD CHANCE POPS TO ROUND OUT THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 150 PM EDT TUE JUL 31 2012 INSTABILITY AS WELL AS A WEAK SHORTWAVE OR SHORTWAVES PASSING BY IN THE FLOW AND AN APPROACHING COLD FRONT WILL MAKE ISOLATED CONVECTION POSSIBLE THROUGHOUT SOUTHEAST KENTUCKY THROUGH INTO THE AFTERNOON BEFORE DIMINISHING AROUND 22Z. LATER TONIGHT...AN APPROACHING COLD FRONT FROM THE NORTH MAY KICK OFF A FEW STORMS AFTER OZ ACROSS THE FORECAST AREA...ESPECIALLY NORTHERN AND EASTERN SECTIONS. WINDS THROUGH THE PERIOD WILL BE LIGHT AND VARIABLE. GIVEN LOW CHANCES OF CONVECTION...NO CB OR TSRA ARE FORECAST AT THE TAF SITES ATTM. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM....MB AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
240 AM EDT TUE JUL 31 2012 .UPDATE... ISSUED AT 215 AM EDT TUE JUL 31 2012 UPDATED THE GRIDS TO REFLECT THE CONVECTION ONGOING OVER THE WESTERN PARTS OF THE CUMBERLAND VALLEY. ALSO MATCHED THE OBS AND TRENDS TO THE SKY...T AND TD GRIDS. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 1015 PM EDT MON JUL 30 2012 CONVECTION ASSOCIATED WITH OUTFLOW BOUNDARIES OVER OUR EASTERN MOST COUNTIES HAS DIED OUT WITH SUNSET. BUT STORMS CONTINUE TO DEVELOP FURTHER TO THE EAST. SO COULD NOT RULE OUT A RENEGADE SHOWER OR THUNDERSTORM SHOULD ANOTHER OUTFLOW SHOOT WESTWARD. FOR NOW WENT OPTIMISTIC AND LEFT ANY MENTION OF POPS OUT OF THE FAR EAST AS CONVECTION HAS A VERY SLOW BUT DEFINITE NORTHEAST TREND IN ITS MOVEMENT. SHORT WAVE ENERGY IS CURRENTLY DROPPING INTO THE LOWER AND MID OHIO VALLEY REGION. THE RUC APPEARS TO HAVE A VERY GOOD HANDLE ON THE SITUATION WITH CONVECTION FIRING IN SOUTHERN IL/IN ATTM. EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP OVER OUR SOUTHWESTERN ZONES AFTER MIDNIGHT AND GENERALLY SOUTH OF A MOUNT VERNON TO WHITESBURG LINE. UPDATED THE FORECAST PACKAGE FOR SOME MINOR TWEAKS...MAINLY TO TEMPS AND DEW POINTS AS TEMPERATURES HAVE DROPPED A LITTLE FASTER THAN ANTICIPATED IN SEVERAL OF OUR VALLEY AREAS. ALSO FRESHENED UP WORDING IN THE ZONE PACKAGE. UPDATE ISSUED AT 721 PM EDT MON JUL 30 2012 OUTFLOW BOUNDARIES GENERATED FROM THUNDERSTORMS OVER WV HAVE BECOME THE FOCUS FOR SOME ISOLD SHOWER ACTIVITY ACROSS PIKE AND LETCHER COUNTIES. UPDATED THE FORECAST PACKAGE FOR THIS ACTIVITY THOUGH EXPECT THINGS TO DIE DOWN QUICKLY AFTER SUNSET. REST OF THE FORECAST IS ON TRACK. ONLY MINOR TWEAKS TO SKY AND POPS. OTHERWISE BROUGHT HOURLY GRIDS IN LINE WITH MOST RECENT OBS. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 330 PM EDT MON JUL 30 2012 AN UPPER LEVEL RIDGE REMAINS CENTERED NEAR THE TX PANHANDLE REGION WITH A TROUGH BETWEEN THIS RIDGE AND ANOTHER OVER THE ATLANTIC. AS A RESULT THE REGION CONTINUES IN NW FLOW ALOFT. AT THE SFC...HIGH PRESSURE HAVE MOVED ON OFF TO OUR N AND E WITH A SFC LOW CENTERED OVER SE MS AND A WARM FRONT EXTENDING SE FROM THE LOW INTO THE TN VALLEY REGION. CONVECTION HAS BEEN PRESENT NEAR THIS BOUNDARY TODAY AS WELL AS OVER SOME OF THE HIGHER TERRAIN OF THE CENTRAL AND SOUTHERN APPALACHIANS. THERE MAY HAVE BEEN A FEW SPRINKLES IN FAR SOUTHERN PIKE COUNTY NEAR THE VA LINE OVER THE PAST HOUR. OTHER THAN A BIT DEEPER CU IN THAT VICINITY...JUST FAIR WEATHER CU HAS BEEN THE DOMINANT FEATURE WITH TEMPS THUS FAR NEAR WHAT WOULD BE EXPECTED IN LATE JULY. A COUPLE OF UPPER LEVEL DISTURBANCES IN THE NW FLOW ALOFT MAY IMPACT THE REGION DURING THE PERIOD. THE FIRST MOVING FROM THE MO VALLEY TOWARD THE MID MS VALLEY REGION IS GENERALLY PROGGED TO TRACK TO THE SW OF THE REGION AND INTERACT WITH THE BOUNDARY SW OF THE REGION. AT THE SFC...THE RELATIVELY WEAK SFC LOW MAY TRACK TOWARD THE MIDDLE TN REGION BY DAWN ON TUE...AND GENERALLY BECOMING DIFFUSE...WHILE A COLD FRONT ASSOCIATED WITH A SHORTWAVE TO MOVE TROUGH THE GREAT LAKES REGION LATE TONIGHT INTO TUE NIGHT APPROACHING THE REGION ON TUE. THIS BOUNDARY SHOULD CROSS THE REGION ON TUE EVENING. SINCE THE FIRST SHORTWAVE IS EXPECTED TO TRACK TO OUR SW AND THE SECOND TO OUR NORTH...THE BEST DYNAMICS AND FORCING WILL NOT BE DIRECTLY OVER THE REGION WITH EITHER ONE. WITH THIS IN MIND...POPS OF NO MORE THAN CHANCE WERE USED. THE NE TWO THIRDS OF THE REGION SHOULD BE FAR ENOUGH NORTHEAST TO REMAIN DRY TONIGHT WITH CONVECTION CHANCES BETTER OVER THE CUMBERLAND VALLEY REGION. CONVECTION ON TUE SHOULD BE DIURNALLY INFLUENCED...WITH THE THREAT LINGERING INTO THE EVENING AS THE BOUNDARY SHOULD NOT CROSS THE AREA UNTIL THE OVERNIGHT. OVER THE NE CWA TONIGHT...PATCHY VALLEY FOG IS AGAIN EXPECTED. AS FOR TEMPS...THERE SHOULD BE A WINDOW ON TUE DURING THE MORNING THROUGH EARLY AFTERNOON WHERE CLOUDS SHOULD THIN. MODEL GUIDANCE POINTED TOWARD A BIT HIGHER MAX T ON TUE THAN THE PREVIOUS FORECAST... NEAR 90 CWA-WIDE. MIN T THROUGH THE PERIOD WILL BE NEAR TO SLIGHTLY ABOVE NORMAL...ESPECIALLY ON TUE NIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 330 PM EDT MON JUL 30 2012 MODELS CONTINUE TO AGREE WITH OVERALL PATTERN EVOLUTION THROUGH THE UPCOMING WEEK. TROF IN THE EASTERN UNITED STATES AND MEAN RIDGE IN THE PLAINS WILL FLATTEN WITH FLOW BECOMING MORE ZONAL ACROSS THE NORTHERN U.S. A SIGNIFICANT SHORT WAVE TROF IS PROGGED TO MOVE EAST IN THE FAST FLOW ACROSS THE FAR NORTHERN PART OF THE COUNTRY DURING THE LATTER PART OF THE WEEK AND DURING THE UPCOMING WEEKEND. MODELS HAVE BEEN TRENDING DRIER FOR THE BEGINNING PART OF THE LONG TERM FORECAST. WILL CARRY ONLY HAVE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE EXTREME EAST ON WEDNESDAY...BASICALLY PIKE COUNTY ONLY...WITH A DRY FORECAST ELSEWHERE. WILL THEN GO WITH A DRY FORECAST FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. AS DEEPER MOISTURE RETURNS IN LOW LEVEL SOUTHWESTERLY FLOW AND WAA PATTERN SETS UP IN ADVANCE OF LOW PRESSURE IN PLAINS WILL SEE A CHANCE OF THUNDERSTORMS RETURN IN THE WEST PART OF FORECAST AREA ON FRIDAY WITH A SLIGHT CHANCE IN THE EAST. AS LOW PRESSURE MOVES EAST ACROSS SOUTHERN CANADA THIS WEEKEND A COLD FRONT WILL APPROACH THE AREA. IT APPEARS THE FRONT WILL NOT MOVE SOUTH OF KY UNTIL MONDAY...THUS KEEPING SHOWER AND THUNDERSTORM CHANCES IN THE FORECAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THE EXTENDED INITIALIZATION PROCEDURE HANDLED THIS WELL WITH RAIN CHANCES CONTINUING INTO MONDAY. MAXIMUM TEMPERATURES SHOULD CONTINUE TO AVERAGE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD...WITH WARMER THAN NORMAL MINIMUM TEMPERATURES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 240 AM EDT TUE JUL 31 2012 A SHORTWAVE INTERACTING WITH A WARM FRONT TO OUR SW IS PRODUCE SOME SHOWER AND THUNDERSTORM ACTIVITY ACROSS SOUTHERN KY...GENERALLY IN THE WESTERN PORTION OF THE CUMBERLAND VALLEY. VFR CIGS WILL BE A POSSIBILITY ACROSS OUR SOUTH AND SOUTHWEST AVN SITES THROUGH THE REMAINDER OF THE NIGHT AND INTO THE FIRST PART OF TUESDAY. MEANWHILE...CLOUD COVER TO THE NE AND IN PARTICULAR JKL...AND PORTIONS OF THE KY...LICKING RIVER BASINS WILL BE THINNER OR NONEXISTENT LEADING TO RIVER VALLEY FOG THROUGH ROUGHLY 14Z POSSIBLY AFFECTING THE K22...PBX...CPF...AND I35 SITES. WINDS THROUGH THE PERIOD WILL BE LIGHT AND VARIABLE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JP LONG TERM....SBH AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1101 AM CDT TUE JUL 31 2012 .DISCUSSION... MOSTLY SUNNY AND WARM...BUT JUST A TAD COOLER THAN YESTERDAY/S PACE MAINLY DUE TO A LITTLE MORE WIND. EVEN SOME GUSTS IN A SPOT OR TWO OVER OUR TEXAS COUNTIES FROM THE SOUTHWEST. NO CHANGE TO EXPECTED HIGHS FOR THE AFTERNOON AND ONLY MINOR CHANGES TO SKY. RAP MODEL HAS PRECIP TO OUR EAST LATER TODAY SO WILL STICK WITH NO POP AT THIS TIME. HOWEVER...WILL KEEP AN EYE FOR ANY SORT OF OUTFLOW TO EMERGE OUT OF SE AR LATER THIS AFTERNOON. WE WILL UPDATE SOME PRODUCTS AT NOON TO REDUCE SOME OF THE WORDING ASSOCIATED WITH THE HEAT PRODUCTS. && .AVIATION... VERY LITTLE CHANGE TO COME IN THE 18Z PACKAGE...AS VFR CONDITIONS ARE EXPECTED TO PERSIST. ISOLATED CONVECTION MAY DEVELOP MID TO LATE AFTERNOON ACROSS SOUTH CENTRAL ARKANSAS INTO NORTH CENTRAL LOUISIANA...BUT POPS ARE TOO SMALL TO MENTION WX IN KELD OR KMLU TERMINAL FORECAST. ANY CONVECTION THAT DOES DEVELOPS SHOULD DIMINISH DURING THE EARLY EVENING. SOUTH TO SOUTHWEST 5 TO 10 KTS WILL BE COMMON ACROSS THE AREA...WITH NO VSBY CONCERNS EXPECTED. /11/ && .PREV DISCUSSION... /ISSUED 352 AM CDT TUE JUL 31 2012/ DISCUSSION... VERY LITTLE CHANGE TO THE OVERALL FCST THIS PKG...AS THE UPPER RIDGE CONTINUES TO CHURN OVER N TX. EXPECTING HEAT INDEX READINGS OF 105+ FOR TODAY AND WEDNESDAY AREAWIDE...WITH SOME AREAS OF N CENTRAL LA REACHING 110 TODAY. HEAT ADVISORY/EXCESSIVE HEAT WARNING WILL CONTINUE AS IS FOR TODAY...AND HAVE EXTENDED THE HEAT ADVISORY THROUGH WED. FOR TEMPS...HAVE STUCK CLOSE TO PERSISTENCE FOR THE SHORT TERM...WHICH APPEARS TO BE RUNNING JUST ABOVE GUIDANCE. THE UPPER RIDGE IS FCST TO INCH WWD ENOUGH TOWARDS THE END OF THE WORK WEEK TO ALLOW FOR WEAK DISTURBANCES TO RIDE ALONG THE ERN PERIPHERY...BRINGING RAIN CHANCES TO N LA/SRN AR FOR THU/FRI... AND TO THE REMAINDER OF THE REGION FOR THE WEEKEND/EARLY PART OF NEXT WORK WEEK. THIS SHOULD ALSO PROVIDE SOME RELIEF FROM THE HEAT...ALBEIT BY ONLY A FEW DEGREES OR SO. /12/ AVIATION... VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE NEXT 24 HOURS. ISOLATED CONVECTION MAY DEVELOP MID TO LATE AFTERNOON ACROSS SOUTH CENTRAL ARKANSAS INTO NORTH CENTRAL LOUISIANA...BUT COVERAGE TOO SMALL TO MENTION IN KELD OR KMLU TERMINAL FORECAST. ANY CONVECTION THAT DOES DEVELOPS SHOULD DIMINISH DURING THE EARLY EVENING. SURFACE WIND ACROSS THE REGION MOSTLY SOUTH TO SOUTHWEST 5 TO 10 KTS. /14/ && .PRELIMINARY POINT TEMPS/POPS... SHV 101 78 101 77 100 / 10 10 10 10 10 MLU 101 77 102 76 99 / 10 10 20 10 30 DEQ 102 73 103 73 103 / 10 10 10 10 10 TXK 102 78 103 76 103 / 10 10 10 10 10 ELD 101 75 102 76 100 / 10 10 20 10 20 TYR 101 79 101 78 101 / 10 10 10 10 10 GGG 101 77 101 78 101 / 10 10 10 10 10 LFK 99 77 99 77 98 / 10 10 10 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR THE FOLLOWING ZONES: ARZ050-051-059>061-070>073. LA...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR THE FOLLOWING ZONES: LAZ001>006-010>012-017. EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: LAZ013-014-018>022. HEAT ADVISORY UNTIL NOON CDT TODAY FOR THE FOLLOWING ZONES: LAZ013-014-018>022. HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT WEDNESDAY FOR THE FOLLOWING ZONES: LAZ013-014-018>022. OK...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR THE FOLLOWING ZONES: OKZ077. TX...HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR THE FOLLOWING ZONES: TXZ096-097-108>112-124>126-136>138-149>153-165>167. && $$ 24/11
AREA FORECAST DISCUSSION
NWS GRAY ME
323 PM EDT TUE JUL 31 2012 .SYNOPSIS... MID ATLANTIC LOW PRESSURE WILL MOVE ALONG THE NEW ENGLAND COAST TONIGHT AND INTO THE CANADIAN MARITIMES WEDNESDAY. A WEAK COLD FRONT WILL MOVE INTO THE REGION FROM THE WEST ON FRIDAY AND BECOME STATIONARY THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... CUMULUS FIELD AND ISOLATED SHOWERS HAVE NOW DEVELOPED OVER COOS COUNTY. THE HRRR MODEL INDICATES A FEW SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE OVER THE HIGHER TERRAIN FOR THE REMAINDER OF THE AFTERNOON. NORTHERN NEW ENGLAND IS CAUGHT IN BETWEEN TWO SYSTEMS...ONE LOCATED TO OUR WEST AND THE OTHER TO OUR SOUTH. A COASTAL LOW PRESSURE SYSTEM WAS DEEPENING NEAR LONG ISLAND THIS AFTERNOON AND WILL MOVE ALONG THE NEW ENGLAND COASTLINE OVERNIGHT. MODELS ARE IN BETTER AGREEMENT THAT COASTAL AREAS AND AREAS AS FAR INLAND AS THE FOOTHILLS WILL SEE PRECIPITATION OVERNIGHT. THE MIDCOAST AREA AS WELL AS THE ISLANDS LOOK TO RECEIVE THE HIGHEST QPF AMOUNTS. CURRENTLY DO NOT EXPECT THUNDERSTORMS...BUT THERE COULD BE A FEW STRIKES OFFSHORE CLOSER TO THE CORE OF THE SYSTEM. WIDESPREAD FOG AND CLOUDY CONDITIONS WILL KEEP TEMPERATURES ON THE WARM SIDE OVERNIGHT. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... THE COASTAL LOW WILL BE JUST OFFSHORE TOMORROW MORNING AND WILL MOVE INTO THE CANADIAN MARITIMES BY EARLY AFTERNOON. AS SHOWERS END OVER THE MIDCOAST REGION (ASSOCIATED WITH THE COASTAL LOW) THEY WILL BEGIN TO CREEP INTO NEW HAMPSHIRE AND WESTERN MAINE AHEAD OF THE COLD FRONT. PW VALUES INCREASE TO NEAR 1.75 INCHES INDICATING POOLING MOISTURE AHEAD OF THE APPROACHING COLD FRONT TO OUR WEST. FORECAST SKEW T PROFILES SHOW SKINNY CAPE...WARM CLOUD LAYERS...AND VERY LIGHT WINDS. THIS ALL POINTS TOWARDS POSSIBLE FLASH FLOODING PROBLEMS. INSTABILITY WILL BE HIGH ENOUGH FOR SCATTERED THUNDERSTORMS. HIGH TEMPERATURES SHOULD REACH THE UPPER 70S/LOWER 80S TOMORROW WITH LOW TEMPERATURES IN THE UPPER 50S TO MID 60S. && .LONG TERM /THURSDAY THROUGH TUESDAY/... COLD FRONT STALLS IN THE NORTHWESTERN PART OF THE AREA ON THURSDAY... A SECOND AREA OF LOW PRESSURE PASSES OFFSHORE OF CAPE COD DURING THE DAY. MOST OF THE RAIN WITH THIS LOW WILL STAY OFFSHORE... BUT INSTABILITY AND LIFT ASSOCIATED WITH THE DISSIPATING COLD FRONT AND A PASSING UPPER LEVEL SHORTWAVE TROUGH MAY LEAD TO A FEW SHOWERS OR THUNDERSTORMS IN INLAND AREAS. AS THE UPPER LEVEL TROUGH PUSHES EAST... A COLD FRONT WILL PUSH SOUTHWARD INTO NORTHERN NEW ENGLAND ON FRIDAY... WITH SHOWERS AND THUNDERSTORMS POSSIBLE ALONG AND AHEAD OF IT. THE FRONT STALLS AS IT GETS CLOSER TO THE COAST ON SATURDAY AND WEAKENS. LARGER TROUGH ALOFT PUSHES EASTWARD OUT OF THE GREAT LAKES SUNDAY INTO MONDAY... WITH LIFT AHEAD OF THIS SYSTEM PROVIDING INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS. THUNDERSTORMS WILL BE MOST LIKELY ON MONDAY AHEAD OF A MORE PRONOUNCED COLD FRONT. TEMPERATURES THROUGH THE PERIOD WILL REMAIN ABOVE NORMAL AS THE JET STREAM STAYS NORTH AND WARM... MOIST AIR CONTINUES TO FLOW INTO NEW ENGLAND. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SHORT TERM...GUSTY SOUTHERLY WINDS THIS AFTERNOON WITH VFR CONDITIONS CONTINUING. LOWERING CEILINGS AND VISIBILITIES WILL ARRIVE AS LOW PRESSURE MOVES ALONG THE NEW ENGLAND COASTLINE TONIGHT. LIFR/IFR CONDITIONS LIKELY AT ALL TERMINALS JUST PRIOR TO MIDNIGHT WITH SHOWERS EVERYWHERE EXCEPT KHIE...KLEB...AND KCON. LONG TERM...GENERALLY VFR EXPECTED... BUT WITH INCREASING MOISTURE LEVELS INTO THE WEEKEND... NOCTURNAL FOG WILL BECOME MORE AND MORE LIKELY ESPECIALLY IN TRADITIONALLY FAVORED AREAS LIKE WHITEFIELD AND LEBANON. && .MARINE... SHORT TERM...WINDS AND SEAS WILL FALL JUST SHORT OF SMALL CRAFT THRESHOLDS LATE TONIGHT INTO WEDNESDAY AS LOW PRESSURE CROSSES THE GULF OF MAINE. LONG TERM...LOW PRESSURE PASSES EAST OF CAPE COD AND INTO NOVA SCOTIA AGAIN ON THURSDAY. BUT WINDS SHOULD STAY BELOW 20 KT. HIGH PRESSURE OVER THE ATLANTIC BRINGS A LIGHT SOUTHERLY FLOW THROUGH THE WEEKEND. && .EQUIPMENT... THE DUAL POLARIZATION RADAR INSTALLATION AT THE NATIONAL WEATHER SERVICE SITE IN GRAY MAINE IS IN PROGRESS. GRAY MAINE /KGYX/ RADAR DATA WILL NOT BE AVAILABLE FOR ANOTHER DAY OR TWO DURING THE INSTALLATION AND FOLLOW UP TESTING OF THIS NEW EQUIPMENT. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ HANES/KIMBLE
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
913 AM EDT TUE JUL 31 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER NORTHERN NEW ENGLAND THROUGH TODAY. LOW PRESSURE WILL APPROACH FROM THE WEST TODAY THROUGH WEDNESDAY. AT THE SAME TIME...MID ATLANTIC LOW PRESSURE WILL MOVE INTO THE CANADIAN MARITIMES. UNSETTLED CONDITIONS IN THE ATMOSPHERE WILL LINGER INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .UPDATE...MINOR CHANGES WERE MADE BASED ON CURRENT OBSERVATIONAL TRENDS. ALSO EXTENDED THE AREA OF SHOWERS FARTHER SOUTH INTO THE FOOTHILLS FOR THIS AFTERNOON BASED ON HRRR GUIDANCE. && PREVIOUS DISCUSSION...EXPECT ANY REMAINING VALLEY FOG TO QUICKLY LIFT AFTER SUNRISE. OTHERWISE TODAY WILL BE MOSTLY QUIET...WITH A GENERAL INCREASE IN CLOUDS FROM THE S. THE EXCEPTION MAY BE ON THE PERIPHERY OF UPPER LEVEL RIDGING...WHERE DIURNAL HEATING MAY BE ENOUGH TO SPARK A SHOWER OR THUNDERSTORM OVER THE HIGH TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... LOW PRESSURE WILL MEANDER NEWD UP THE COAST TONIGHT...PASSING THOUGH THE GULF OF MAINE IN THE PROCESS. THERE REMAIN TWO CAMPS AMONG MODEL GUIDANCE. THE NAM/GFS FAVOR A TRACK CLOSER TO THE COAST...AND SUBSEQUENTLY MORE RAINFALL FOR COASTAL AREAS OVERNIGHT. CONVERSELY...THE ECMWF...UKMET...AND GEM ALL MERELY BRUSH THE COAST WITH SHOWERS. HAVE FAVORED AROUND A 1/3 BLEND OF THE NORTH AMERICAN MODELS...WHICH PLACES LIKELY POP OFFSHORE TONIGHT. THIS REPRESENTS A SLIGHT INCREASE IN POP FOR THE COAST AND INTERIOR...WITH HIGH CHC POP AT TIMES TONIGHT. LOW PRESSURE WILL DEPART TO OUR NE...WHILE A COLD FRONT APPROACHES FROM THE W. THIS WILL LEAVE A SMALL BREAK IN THE ACTION...BEFORE SHOWERS/THUNDERSTORMS ENTER THE WRN ZONES OF THE CWA. WITH LOW PRESSURE OFF TO THE E...THE COLD FRONT WILL BE SLOW MOVING. ATTM...EXPECTING THAT MUCH OF WED WILL SEE RAINFALL CONFINED TO THE WRN HALF OF THE CWA. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... THE EXTENDED FORECAST WILL BE DOMINATED BY MAINLY DRY CONDITIONS...WITH DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS THROUGHOUT MUCH OF THE PERIOD. AS COASTAL LOW PASSES TO OUR EAST WEDNESDAY MORNING...EXPECT DRYING CONDS WITH OFFSHORE NORTHWESTERLY WINDS MUCH OF THE DAY. THIS SUNSHINE WILL ALLOW FOR SUFFICIENT HEATING TO PRODUCE LATE DAY SCATTERED SHOWERS/THUNDERSTORMS BUILDING FROM WEST TO EAST AS A TROUGH APPROACHES FROM UPSTATE NEW YORK. WEAK TROUGH IN THE UPPER ATMOSPHERE WILL ALLOW FOR MORE MAINLY DIURNALLY DRIVEN SCATTERED -SHOWERS/THUNDERSTORMS ON THURSDAY AND ALSO ON FRIDAY AS THE ATMOSPHERE BECOMES UNSTABLE DURING THE MIDDLE PART OF THE AFTN EACH DAY. THE PASSAGE OF A WEAK SURFACE BOUNDARY MAY ALLOW FOR SLIGHTLY HIGHER POPS BY FRIDAY AFTERNOON. A MORE DYNAMICALLY DRIVEN SYSTEM MOVES OVER THE GREAT LAKES AND THROUGH SOUTHERN CANADA OVER THE WEEKEND...BRINGING MORE SCATTERED SHOWERS AND STORMS TO THE REGION. ONCE AGAIN...MUCH OF THE EXTENDED FORECAST WILL BE DRY...WITH ANY GIVEN SHOWERS OR STORMS LIKELY TO BE BRIEF AND SCATTERED ACROSS THE REGION. YET MORE UNSETTLED WEATHER WILL BEGIN THE START OF NEXT WEEK AS WELL. USED A BLEND OF MEX AND GMOS NUMBERS FOR OVERNIGHT LOWS DURING MUCH OF THE LONG RANGE. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/... SHORT TERM...GENERALLY VFR CONDS EXPECTED TO PREVAIL. WILL SEE PATCHY VALLEY FOG TONIGHT...THAT COULD REACH MVFR OR LOWER VSBYS AND POSSIBLY CIGS. LOW PRESSURE DRIFTING UP THE COAST MAY SPREAD MVFR CONDS INTO COASTAL TERMINALS LATE TONIGHT INTO WED MORNING. LONG TERM... MAINLY VFR EXPECTED THROUGH THE PERIOD WEDNESDAY THROUGH SATURDAY. HOWEVER...A FEW BRIEF PERIODS OF MVFR TO IFR POSSIBLE ESPECIALLY LATE AT NIGHT IN FOG/STRATUS...AS WELL AS AFTERNOON SHOWERS AND THUNDERSTORMS. && .MARINE... SHORT TERM...WINDS AND SEAS WILL APPROACH SCA THRESHOLDS LATE TONIGHT INTO WED AS LOW PRESSURE CROSSES THE GULF OF MAINE. LONG TERM...NO FLAGS EXPECTED THROUGH THE WEEKEND. && .EQUIPMENT... SPECIAL NOTE: COMMUNICATIONS CIRCUIT MAY HAVE BEEN FIXED AT KRKD AND KLEW. OBSERVATIONS HAVE BEGUN FLOWING AGAIN THROUGH NORMAL CHANNELS... AND IF THIS CONTINUES THE ISSUE MAY HAVE BEEN MORE PERMANENTLY FIXED. TAF FOR KRKD WILL NO LONGER INCLUDE "AMD NOT SKED" AND WILL RETURN TO THE NORMAL REMARKS OF "AMD LTD TO CLD VIS AND WIND" UNLESS THE COMMUNICATIONS PROBLEM RETURNS. GRAY MAINE /KGYX/ RADAR DATA WILL NOT BE AVAILABLE FOR SEVERAL DAYS. THE DUAL POLARIZATION RADAR INSTALLATION AT THE NATIONAL WEATHER SERVICE SITE IN GRAY MAINE IS IN PROGRESS. DURING THE INSTALLATION AND FOLLOW UP TESTING OF THIS NEW EQUIPMENT... RADAR DATA WILL BE UNAVAILABLE FROM THIS SITE. THIS COULD TAKE A FEW MORE DAYS TO COMPLETE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ UPDATE...HANES
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
353 PM EDT TUE JUL 31 2012 .SYNOPSIS... AN UPPER LEVEL TROUGH WILL REMAIN OVER THE MID ATLANTIC STATES THROUGH WEDNESDAY...RESULTING IN DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. THE TROUGH WILL LIFT OFF TO THE NORTHEAST THURSDAY AND FRIDAY...BRINGING SLIGHTLY HOTTER CONDITIONS AND LOWER CHANCES FOR PRECIPITATION. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS CONTINUES TO FEATURE WEAK AND RATHER DIFFUSE COASTAL FRONT/SFC TROUGH DRAPED ACROSS NE NC COASTAL PLAIN. ALOFT, UPPER LEVEL TROUGH REMAINS IN PLACE OVER SE CANADA, EXTENDING SOUTH ACROSS THE EASTERN SEABOARD, WITH NUMEROUS WEAK DISTURBANCES EMBEDDED WITHIN NW FLOW ALOFT. S/W RESULTING IN COMPLEX OF TSTMS ACROSS THE SOUTHEAST POISED TO TRACK E THROUGH THE CAROLINAS/GA OVER THE COURSE OF THE AFTN. ALREADY SEEING SHRAS FORMING ALONG AXIS OF BEST OMEGA OVER THE WESTERN CWA. RAP SEEMS TO HAVE A PRETTY GOOD HANDLE ON THIS ACTIVITY THUS FAR, PUSHING THIS ACTIVITY TO THE SOUTH-SOUTHWEST THROUGH 00Z. MAIN HAZARD THROUGH EARLY EVENING WILL BE WITH LCL HEAVY RAINFALL WITH SLOW MOVING STORMS, AND WILL NOTE THIS IN HWO. AS WITH THE PAST FEW DAYS, MUCH OF SHRA ACTIVITY SHOULD DIMINISH AFTER SUNSET, WITH PARTIAL CLEARING THROUGH MIDNIGHT. DEPENDING ON AMOUNT OF CLEARING, SOME PATCHY FOG IS POSSIBLE LATE, ESPECIALLY INLAND. OTHERWISE, WARM AND MUGGY TONIGHT WITH EARLY MORNING LOWS GENERALLY IN THE L70S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... WEDNESDAY... UPPER TROUGH DIGS/SHARPENS OVER THE REGION FOR WED, WITH ANOTHER SHORTWAVE DROPPING SE FROM THE OHIO VLY AND PUSHING ACROSS THE REGION WED AFTN. MEANWHILE, LLVL WINDS VEER AROUND TO THE S-SE. GOOD MODEL AGREEMENT IN SPINNING UP A WEAK AREA LOW PRES ALONG THE PERSISTENT COASTAL TROUGH OVER E GA/S SC EARLY WED...WITH THIS FEATURE EXPECTED TO MOVE NE ALONG THE CAROLINA COAST THROUGH WED AFTN/NIGHT. AT MINIMUM THIS WILL LIKELY RESULT IN A SIGNIFICANTLY MORE CLOUDY DAY THAN PRESENT FORECAST WOULD SUGGEST, AND HAVE ACCORDINGLY NUDGED TEMPS DOWNWARD ACROSS SE VA/NE NC COAST. DOWNSLOPE FLOW ALOFT AND COMPRESSIONAL HEATING/SUBSIDENCE AHEAD OF APPROACHING COLD FRONT TO THE NORTH WILL MAKE FOR A WARMER DAY INLAND, WITH HIGHS ~90. WILL CARRY AT LEAST 30% POPS ONCE AGAIN FOR MAINLY AFTN/EVENING TSTMS INLAND. HIGHS IN LOW-MID 80S EAST TO UPR 80S TO LWR 90S WELL INLAND. THURSDAY/FRIDAY... UPPER TROUGH PIVOTS OFFSHORE FOR THURSDAY. IN ITS WAKE, FLOW BECOMES QUASI-ZONAL ALOFT W/S-SW FLOW IN LOW LEVELS. GIVEN ANOTHER WEAK SHORTWAVE TROUGH CROSSING THE AREA THU AFTN ALONG WITH MODERATELY UNSTABLE MLCAPE VALUES AND INSTABILITY PARAMETERS, WILL CARRY 20-30% POP FOR THU...WITH HIGHS INTO THE 90S WELL INLAND AND UPR 80S NEAR THE COAST. HEAT RIDGE OVER THE PLAINS TRANSLATES A BIT FARTHER EAST ON FRIDAY AS UPPER FLOW FLATTENS OUT A BIT MORE OVER THE LOCAL AREA. STRONGER RETURN FLOW WILL BRING ANOTHER VERY WARM DAY TO THE REGION. ONCE AGAIN EXPECT MAINLY DIURNALLY DRIVEN LATE AFTN/EVENING TSRA ALONG ANOTHER DEVELOPING NUMERICAL GUIDANCE HAS BEEN RUNNING A BIT COOL IN THE DAY 3-4 PERIOD AND HV ACCORDINGLY GONE JUST ABOVE WARMEST GUIDANCE, WHICH IS IN LINE WITH LCL THICKNESS TOOL OUTPUT. EXPECT HIGHS INTO THE MID 90S INLAND/AROUND 90 COASTAL ZONES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... TYPICAL SUMMER TIME CONDITIONS EXPECTED FOR THE AREA. NEXT FRONT APPROACHES THE AREA MONDAY AND TUESDAY. THIS FRONT LIKELY TO DISSIPATE ACROSS THE AREA. MODELS FAIRLY SIMILAR WITH FRONTAL BOUNDARY ON MONDAY AND TUESDAY AND THIS WILL BE THE BEST CHANCES FOR THUNDERSTORMS. MAINLY WEAK FLOW FROM THE SOUTH EARLIER AND THIS WILL GIVE A CHANCE OF MAINLY AFTERNOON THUNDERSTORMS. TEMPERATURES WILL AGAIN BE MAINLY IN THE 90S FOR HIGHS AND 70S FOR LOWS THROUGH THE PERIOD. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... SYNOPTIC SCALE TROUGH REMAINS IN PLACE OVER THE EASTERN SEABOARD THIS AFTERNOON THROUGH THE DAY ON WEDNESDAY. WITH THAT TROUGH WILL SEE SEVERAL PIECES OF SHORTWAVE ENERGY THAT WILL ROTATE THROUGH THE TROUGH AND COULD PRODUCE SOME BANDS OF SHOWERS AND THUNDERSTORMS. FOR THIS AFTERNOON...A WEAK SURFACE LOW IS LIFTING NE ALONG THE COAST AND IS HELPING TO PRODUCE SOME NE FLOW ALONG THE DELMARVA AND A LIGHT EASTERLY FLOW MAINLY EAST OF I-95. THIS HAS LEFT A WEAK SFC BOUNDARY FROM JUST SOUTH OF ORF TO AKQ TO PTB AND THEN NW TOWARD CHO. ALONG THIS BOUNDARY...SOME LOW LEVEL CONVERGENCE IS PRODUCING SOME SCATTERED CONVECTION WHICH SHOULD BUILD THROUGH THE AFTERNOON. THIS COULD PUSH SHOWERS INTO RIC/ORF LATER THIS AFTERNOON. AT THIS TIME HAVE JUST HINTED AT THE SHOWERS WITH VCTS. MORE CONVECTION IS DEVELOPING OVER THE DELMARVA AND CONTINUES TO BUILDS...SO HAVE ADDED A MVFR TEMPO GROUP EXPECTING THESE SHOWERS TO MOVE EAST. AFTER 00Z...COULD SEE THE CONVECTION OVER THE MOUNTAINS TO ROLL EAST...BUT EXPECT THAT IT WILL BE SCATTERED TO ISOLATED AND WEAKENING SO HAVE NOT SHOWN THIS IN THE FORECAST. MAINLY EXPECT TO SEE JUST SOME BROKEN MID TO HIGH LEVEL CLOUDS IN RESPONSE TO THE DYING CONVECTION. ON WEDNESDAY...SHOULD SEE A LIGHT SOUTHERLY FLOW DEVELOP AS A DYING COOL FRONT MOVES ACROSS THE AREA AND REINFORCES THE SFC FRONT JUST TO THE EAST OF THE AREA. THIS WILL HELP TO ENHANCE A SFC LOW MOVING NE ALONG THE FRONT...WHICH WILL PRODUCE SHOWERS AND TSTMS ACROSS NE NC AND THE TIDEWATER SO ORF AND ECG COULD SEE SOME RESTRICTIONS DUE TO THE SHOWERS. OUTLOOK...THE UPPER TOUGH SLIDES OFF THE COAST WED NIGHT INTO THURSDAY MORNING AND WITH IT EXPECT VFR CONDITIONS TO PREVAIL INTO SUNDAY. && .MARINE... NO HEADLINES IN THE SHORT TERM TNGT THRU THU. WEAK LO PRES MOVNG AWAY OFF THE NJ CST TNGT...WITH ESE WNDS LESS THAN 15 KT TURNING TO THE S 10 KT OR LESS OVRNGT INTO WED MORNG. ANOTHER WEAK LO PRES AREA WILL MOVE UP OFF THE MID ATLC CST LATE WED NGT THRU THU MORNG...TURNING WNDS 15 KT OR LESS TO THE NE...N THEN NW. OTHRWISE...EXPECT MAINLY S OR SW WNDS LESS THAN 15 KT FOR MUCH OF THE FCST PERIOD TNGT THRU SUN. WAVES 1 TO 3 FT AND SEAS 2 TO 4 FT. && .CLIMATE... PRELIMINARY DATA FOR JULY SHOWING THAT ALL 3 MAIN CLIMATE SITES (RIC/ORF/SBY) WILL EASILY RANK IN THE TOP 10 WARMEST ON RECORD. RICHMOND LIKELY TO BE 2ND WARMEST...NORFOLK LIKELY TO BE 5TH WARMEST...AND SBY LIKELY TO BE THE WARMEST ON RECORD. WHEN CLIMATE DATA IS AVAILABLE LATER THIS EVENING A PNS WILL BE ISSUED. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...ALB LONG TERM...JAB AVIATION...ESS MARINE...TMG CLIMATE...AKQ EQUIPMENT...AKQ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
332 PM EDT TUE JUL 31 2012 .SYNOPSIS... INCREASING HUMIDITY AND A SLOW SOUTHEASTBOUND LOW PRESSURE SYSTEM WILL FUEL SCATTERED SHOWERS AND THUNDERSTORMS INTO WEDNESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... PER RECENT SURFACE AND RADAR DATA, HAVE MENTION OF THUNDERSTORMS ACROSS THE APPALACHIAN MOUNTAINS, WITH GUSTY WIND, HAIL, FREQUENT LIGHTNING, AND HEAVY RAIN. FARTHER WEST, HAVE MAINTAINED A FORECAST OF INCREASING COVERAGE OF THUNDERSTORMS THROUGH EARLY EVENING. HAVE ALSO ADDED MENTION OF GUSTY WIND, HAIL, FREQUENT LIGHTNING, AND HEAVY RAIN. RECENT SATELLITE DATA SHOWS CUMULONIMBUS DEVELOPING WITHIN THE BAND OF ALTOCUMULUS, ASSOCIATED WITH LIFT FROM LOW PRESSURE TROUGH CONTINUING TO MOVE SLOWLY SOUTHEASTWARD ACROSS NORTHWEST PENNSYLVANIA AND THE STATE OF OHIO. THIS SHOULD BE FOCUS OF THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AS SHOWN BY 00Z WRF-NMM AND RECENT HRRR MODEL OUTPUT. REGARDING HEAVY RAINFALL POTENTIAL, PRECIPITABLE WATER IS NOW UP TO 1.4 INCHES. RECENT FLASH FLOOD GUIDANCE SUGGESTS 2 INCHES OF RAIN IN LESS THAN 3 HOURS NEEDED FOR FLOODING PROBLEMS TO DEVELOP. EXPECT THUNDERSTORM CHANCES TO DECREASE OVERNIGHT DUE TO THE EVENTUAL OVERNIGHT PASSAGE OF THE LOW PRESSURE TROUGH AND THE STABILIZING EFFECTS OF NIGHTTIME SURFACE LAYER COOLING. WITH EXPECTED ADDED RAINFALL, HAVE ADDED LATE NIGHT PATCHY FOG, MORE WIDESPREAD ACROSS THE WV-MD MOUNTAINS AND PA LAUREL HIGHLANDS. MADE MINIMAL TEMPERATURE ADJUSTMENTS BASED ON RECENT GFS LAMP AND MOS OUTPUT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... HAVE MAINTAINED A CHANCE OF THUNDERSTORMS DAYTIME WEDNESDAY, MORE SO DUE TO LATENT INSTABILITY ASSOCIATED WITH THE LINGERING HUMID SURFACE LAYER CONDITIONS. HIGH PRESSURE SUBSIDENCE SHOULD PROVIDE MORE STABILIZATION THURSDAY AND FRIDAY, AND THUS DRY CONDITIONS, DESPITE SURFACE DEW POINTS SHOWING SLIGHTLY MORE HUMID THAN NORMAL CONDITIONS. FORECASTED WARMER AFTERNOON HIGHS THURSDAY AND FRIDAY THAN WEDNESDAY. IN FACT, GFS AND ECMWF MOS SHOW HIGHS OF 90 CAN OCCUR ACROSS LOWER ELEVATIONS, PARTICULARLY FRIDAY. EARLY MORNING LOWS WILL BE SLIGHTLY WARMER THAN NORMAL. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... CONTINUED HUMID AND VERY WARM CONDITIONS WILL EVOLVE INTO UNSETTLED CONDITIONS THIS PERIOD. CONSENSUS OF MODELS SHOW A STRONG UPPER LEVEL TROUGH AND CLOSED SURFACE LOW TRACKING, EAST ALONG THE CANADIAN BORDER THIS WEEKEND THAT WILL PASS EASTWARD THROUGH THE EASTERN GREAT LAKES MONDAY. INSTABILITY WILL BE INCREASED AS ALREADY HUMID CONDITIONS WILL BE FURTHER AUGMENTED BY LOW LEVEL SOUTHERLY WINDS PROVIDING AN ADDITIONAL INFLUX OF GULF MOISTURE. SO EXPECT A DECENT CHANCE OF THUNDERSTORMS ACROSS THE UPPER OHIO VALLEY THIS WEEKEND INTO MONDAY. SURFACE HIGH PRESSURE IS PROGGED TO PROVIDE DRY, STABLE CONDITIONS TUESDAY. FORECASTED TEMPERATURES TO CONTINUE AT LEAST SLIGHTLY WARMER THAN NORMAL BASED ON BLEND OF RECENT GFS AND ECMWF MOS AND NAEFS MEDIAN VALUES. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/.. EXPECT INCREASE IN COVERAGE OF THUNDERSTORMS AND POTENTIAL OF MAINLY MVFR RESTRICTIONS ACROSS THE UPPER OHIO VALLEY THROUGH EARLY EVENING. SCATTERED THUNDERSTORMS NEAR THE MOUNTAINS WILL BE JOINED BY A DEVELOPING BAND OF THUNDERSTORMS SHOWN BY RECENT HRRR MODEL OUTPUT. SO TAFS CONTINUED TO HAVE MENTION OF TEMPO MVFR RESTRICTIONS IN THUNDERSTORMS FOR ALL TAFS THROUGH 02Z. HAVE LIKEWISE MAINTAINED MENTION OF A SECOND ROUND OF MAINLY MVFR RESTRICTIONS DUE TO LATE NIGHT FOG. THUNDERSTORMS WITH POTENTIAL RESTRICTIONS ARE STILL POSSIBLE ON WEDNESDAY, UNTIL AN UPPER LEVEL TROUGH EXITS EAST OF THE MOUNTAINS. OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY... EXPECT VFR AND GENERALLY DRY CONDITIONS FOR THURSDAY AND FRIDAY. RESTRICTIONS WILL BE POSSIBLE AGAIN WITH THUNDERSTORMS SATURDAY AND SUNDAY, AS ANOTHER LOW PRESSURE SYSTEM MOVES INTO THE GREAT LAKES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
203 PM EDT TUE JUL 31 2012 .SYNOPSIS... INCREASING HUMIDITY AND A SLOW SOUTHEASTBOUND LOW PRESSURE SYSTEM WILL FUEL SCATTERED SHOWERS AND THUNDERSTORMS INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... PER RECENT SURFACE AND RADAR DATA, HAVE ACCELERATED INCREASE COVERAGE OF THUNDERSTORMS ACROSS THE APPALACHIAN MOUNTAINS, AND HAVE ALSO ADDED MENTION OF GUSTY WIND, HAIL, FREQUENT LIGHTNING, AND HEAVY RAIN. ELSEWHERE, HAVE SLOWED INCREASE IN COVERAGE OF THUNDERSTORMS, ALTHOUGH MAINTAINED MENTION OF LIKELY THUNDERSTORMS THIS EVENING AREA WIDE. RECENT SATELLITE DATA SHOWS ALTOCUMULUS, ASSOCIATED WITH LIFT FROM LOW PRESSURE TROUGH CONTINUING TO MOVE SLOWLY SOUTHEASTWARD ACROSS LAKE ERIE AND THE STATE OF OHIO. THIS SHOULD BE FOCUS OF THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AS SHOWN BY 00Z WRF-NMM AND RECENT HRRR MODEL OUTPUT. SPC CONTINUES TO PROJECT RESTRICTED POTENTIAL OF SEVERE DEVELOPMENT, MORE SO FROM WIND THAN HAIL. REGARDING HEAVY RAINFALL POTENTIAL, PRECIPITABLE WATER IS NOW UP TO 1.4 INCHES. RECENT FLASH FLOOD GUIDANCE SUGGESTS 2 INCHES OF RAIN IN LESS THAN 3 HOURS NEEDED FOR FLOODING PROBLEMS TO DEVELOP. EXPECT THUNDERSTORM CHANCES TO DECREASE OVERNIGHT DUE TO THE EVENTUAL OVERNIGHT PASSAGE OF THE LOW PRESSURE TROUGH AND THE STABILIZING EFFECTS OF NIGHTTIME SURFACE LAYER COOLING. MADE MINIMAL TEMPERATURE ADJUSTMENTS BASED ON RECENT GFS LAMP AND MOS OUTPUT. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... HAVE MAINTAINED A CHANCE OF THUNDERSTORMS DAYTIME WEDNESDAY, MORE SO DUE TO LATENT INSTABILITY ASSOCIATED WITH THE LINGERING HUMID SURFACE LAYER CONDITIONS. HIGH PRESSURE SUBSIDENCE SHOULD PROVIDE MORE STABILIZATION THURSDAY AND FRIDAY, AND THUS DRY CONDITIONS, DESPITE SURFACE DEW POINTS SHOWING SLIGHTLY MORE HUMID THAN NORMAL CONDITIONS. FORECASTED WARMER AFTERNOON HIGHS THURSDAY AND FRIDAY THAN WEDNESDAY. IN FACT, GFS AND ECMWF MOS SHOW HIGHS OF 90 CAN OCCUR ACROSS LOWER ELEVATIONS, PARTICULARLY FRIDAY. EARLY MORNING LOWS WILL BE SLIGHTLY WARMER THAN NORMAL. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... SLIGHTLY UNSETTLED PATTERN FOR THE LONG TERM PORTION OF THE FORECAST. TRENDED AWAY FROM THE ECMWF...WHICH SEEMED TO HANG A FRONT OVER THE REGION MUCH LONGER THAN OTHER DETERMINISTIC/ENSEMBLE MODELS. BEST CHANCE FOR RAIN APPEARS TO BE SUNDAY INTO SUNDAY NIGHT...WITH SOME TIMING CONSENSUS FOR FRONT FROM GFS/CMC/GEFS. TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL BEFORE THE FRONTAL PASSAGE...RETURNING TO NORMAL BY SUNDAY AND MONDAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... HAVE INCLUDED A TEMPO GROUP FOR MAINLY MVFR RESTRICTIONS IN THUNDERSTORMS STARTING AROUND 19Z IN THE NORTH AND 23Z IN THE SOUTH AS RECENT MODEL OUTPUT CONTINUES TO SHOW A BAND OF THUNDERSTORMS MOVING SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY. HAVE INCLUDED MENTION OF A SECOND ROUND OF MAINLY MVFR RESTRICTIONS DUE TO LATE NIGHT FOG. OUTLOOK...WEDNESDAY THROUGH SATURDAY... SCATTERED SHOWERS/STORMS WITH POSSIBLE RESTRICTIONS CAN OCCUR WEDNESDAY. THEN EXPECT VFR AND GENERALLY DRY CONDITIONS FOR THURSDAY AND FRIDAY. RESTRICTIONS WILL BE POSSIBLE AGAIN IN SCATTERED SHOWERS/STORMS SATURDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
936 PM EDT WED AUG 1 2012 .UPDATE... ISSUED AT 934 PM EDT WED AUG 1 2012 CONVECTIVE TRENDS MAIN ISSUE FOR THE LATE EVENING AND OVERNIGHT. LOW PRESSURE OVR NORTH END OF LK SUPERIOR WHILE COLD FRONT IS CLOSING IN ON FAR WESTERN UPR MICHIGAN. THERE ARE TWO MAIN SHORTWAVE TROUGHS OVR THE REGION. FIRST WAVE IS PUSHING ACROSS EASTERN LK SUPERIOR AND COMBINED WITH H85 THETA-E ADVECTION HAS DRIVEN SHRA/TSRA THAT HAVE BEEN ROAMING OVER EASTERN LK SUPERIOR AND FAR EASTERN CWA THIS EVENING. SECOND WAVE IS PUSHING INTO WESTERN MINNESOTA AND HAS KICKED OFF COMPLEX OF STRONG TSRA OVER SW MINNESOTA. ANOTHER WAVE IS UPSTREAM OVR SOUTHERN MANITOBA AND MAY HAVE AFFECT ON WX LATER TONIGHT. CONVECTION OVR WEST HALF OF UPR MICHIGAN PRETTY MUCH NIL THIS EVENING DESPITE HIGHER INSTABILITY /MLCAPES UPWARDS OF 2000 J/KG AND APPROACHING COLD FRONT. MAIN REASON FOR MINIMAL CONVECTION IS PROBABLY LARGE AREA OF MINIMUM H7 DWPNT...WHICH IS LIKELY EXTENDING LOWER INTO THE LOWER LAYERS OF THE ATMOSPHERE. RUC INDICATES INCREASE OF H7 MOISTURE AFT MIDNIGHT AS THE COLD FRONT PUSHES INTO CNTRL UPR MICHIGAN. THE INCREASED MOISTURE H85-H7 MOISTURE ADVECTION INTO THE FRONT IN PRESENSE OF THE UPSTREAM SHORTWAVE OVR MANITOBA COULD BE ENOUGH TO TRIGGER SHRA/TSRA OVERNIGHT MAINLY OVER THE SOUTH INTO THE EASTERN CWA. STILL A RISK OF ISOLD STRONGER STORMS AS INSTIBILITY AND SHEAR REMAIN MORE THAN SUFFICIENT. AFTER LATE TONIGHT...GOING FLAVOR OF PREVIOUS FCST STILL THERE WITH COLD FRONT STALLING OUT OVR SOUTH CENTRAL CWA ON THURSDAY. POPS REMAIN SLIGHT CHANCE FOR NOW FOR THIS...BUT MAY NEED INCREASING LATER TONIGHT ONCE NEXT UPSTREAM WAVE IS SORTED OUT. ONLY CHANGE OF NOTE FOR FCST WAS TO RESTRUCTURE POPS THROUGH THE OVERNIGHT BASED ON LATEST MESOANALYSIS/RADAR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 327 PM EDT WED AUG 1 2012 A 1002MB SFC LOW IS CENTERED JUST NW OF LAKE SUPERIOR WITH AN ASSOCIATED MID/UPPER LEVEL SHORTWAVE OVERHEAD. A SFC COLD FRONT IS CURRENTLY STRETCHED FROM THE SFC LOW SW TO FAR NRN MN. ANOTHER SHORTWAVE RIDING OVER THE UPPER RIDGE OVER THE WRN CONUS WAS LOCATED JUST N OF LAKE SUPERIOR AT 14Z TODAY...CAUSING THUNDERSTORMS TO MOVE N OF LAKE SUPERIOR. ANOTHER CLUSTER OF THUNDERSTORMS WAS OVER ERN MN LATE THIS MORNING...WHERE MORE MOISTURE WAS PRESENT. BY AROUND 17Z TODAY...THE STORMS MADE THEIR WAY INTO FAR WRN UPPER MI NEAR IWD...AND ARE NOW /19Z/ LOCATED OVER WRN IRON/SRN HOUGHTON COUNTIES. A COUPLE OF THE STORMS WERE STRONGER NEAR IWD...AND A COUPLE WERE SEVERE JUST S OF GOGEBIC COUNTY. CLEARING BEHIND THESE STORMS...ALONG WITH ALREADY HIGH SFC DEW PTS...MAY LEAD TO INCREASED INSTABILITY OVER FAR WRN UPPER MI LATE THIS AFTERNOON. THERE IS A RISK FOR SOME STRONGER THUNDERSTORMS OVER THE FAR W INTO THIS EVENING. DRY AIR OVER THE AREA HAS LEAD TO LARGE DCAPES...SO STRONG WINDS WOULD BE A THREAT WITH ANY SIGNIFICANT CONVECTION. MLCAPES UP TO 2000J/KG WILL BE POSSIBLE WITH 0-6KM SHEAR OF 30-40KTS...ALSO LEADING TO A HAIL THREAT. MODEL QPF VARIES WIDELY FROM MODEL TO MODEL...FURTHER LIMITING CONFIDENCE IN COVERAGE THIS EVENING THROUGH TONIGHT. OVERALL...BEST CHANCES FOR CONVECTION WILL BE THIS AFTERNOON INTO THIS EVENING ALONG THE WI BORDER OVER THE W. 850MB TEMPS TODAY WERE AROUND 20C...BUT NW WINDS BEHIND THE COLD FRONT TOMORROW WILL KEEP 850MB TEMPS AROUND 15C S TO 11C N...SO TEMPS WILL QUITE A BIT COOLER /ESPECIALLY NEAR LAKE SUPERIOR/. THIS WILL LEAD TO HIGHS IN THE 70S N TO 80S S. SINCE THE COLD FRONT LOOKS TO BE S OF THE CWA BY 12Z THU...WILL CUT BACK POPS FROM PREVIOUS SHIFT. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 327 PM EDT WED AUG 1 2012 HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES...BEHIND THE COLD FRONT WHICH WILL BE MOVING ACROSS THE LOWER GREAT LAKES AND NEW ENGLAND STATES. WHILE THE CENTER OF THE SFC LOW WILL REMAIN TO OUR NE...LIGHT WINDS WILL PREVAIL...WITH SOME RETURN FLOW OVER THE W HALF CLOSER TO THE NEARING SFC LOW OVER THE PLAINS STATES THROUGH MANITOBA. NORTHWEST FLOW WILL CONTINUE ALOFT THURSDAY NIGHT...WITH THE MAIN 500MB LOW STILL SPINNING OVER NE HUDSON BAY/N QUEBEC...AND THE NEXT LOW PUSHING ACROSS THE PACIFIC NW/SW CANADA. SLIGHT RIDGING TO ZONAL FLOW FRIDAY...OUT AS THE WESTERN 500MB LOW DIGS ACROSS THE DAKOTAS. THE LOW WILL CONTINUE TO DEEPEN AS IT SHIFTS ACROSS N MN/W ONTARIO BY 18Z SATURDAY. THE GFS/CANADIAN ARE MORE PROGRESSIVE WITH THE 500MB LOW /NEAR JAMES BAY/...WHILE THE ECMWF IS STILL OVER N LS AND CENTRAL ONTARIO. WINDS JUST ABOVE THE SFC FRIDAY NIGHT COULD BE QUITE STRONG...WITH NEARLY UNIDIRECTIONAL SW WINDS OF 30-40KTS AT AND ABOVE 925MB. SOME DRY AIR AT THE SFC INITIALLY SHOULD PRECLUDE STRONG TS DEVELOPMENT...BUT COULD DEPEND ON THE LOCATION OF THE WARM FRONT. MLCAPE VALUES JUMP TO 500-1100J/KG OVER THE W LAND AWAY FROM THE KEWEENAW PENINUSLA BY 12Z SATURDAY...WITH 45-55KT LLJ OVER THE ENTIRE W HALF. THIS STRONG WAA SHOULD KEEP TEMPS FROM FALLING MUCH BELOW 65F...PARTICULARLY OVER THE W HALF DOWNSLOPE LOCATIONS NEAR LS. 850MB TEMPS JUMP TO AROUND 18C SATURDAY AFTERNOON CWA WIDE UNTIL THE PASSAGE OF THE COLD FRONT BY MID/LATE AFTERNOON W. NO MATTER WHICH SOLUTION PANS OUT ALOFT...NW FLOW WILL RETURN BY SUNDAY NIGHT THROUGH MID DAY TUESDAY. LINGERING CLOUDS ON FAVORABLE NW WINDS AND 850MB TEMPS OF 7-8C SHOULD KEEP A FEW CLOUDS SET UP N CENTRAL AND E SUNDAY MORNING. A FEW DIFFICULT TO PREDICT SHORTWAVES LOOK TO SWING THROUGH OR TO OUR N IN THE FAST NW FLOW. THE LARGE SCALE TROUGH SET UP FROM CENTRAL CANADA THROUGH THE MID ATLANTIC WILL BRING MORE ZONAL FLOW TO THE UPPER GREAT LAKES ON WEDNESDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 808 PM EDT WED AUG 1 2012 A LOW PRESSURE SYSTEM MOVING JUST NORTH OF LAKE SUPERIOR WILL PROPEL A COLD FRONT THROUGH IWD AND CMX BY MIDNIGHT AND AT SAW OVERNIGHT. DRY AIR ALOFT HAS LIMITED SHRA/TSRA THUS FAR...BUT THERE IS A RISK OVERNIGHT AT IWD AND SAW AS THE FRONT PUSHES THROUGH AND MOISTURE INCREASES ALOFT. ATTN LATER TONIGHT AND INTO THURSDAYS TURNS TO POST-FRONTAL LOWER CLOUDS. CIGS UPSTREAM IN MANITOBA AND ONTARIO MVFR AND EVEN IFR. KEPT PREVIOUS FCST THEME OF BKN LOWER MVFR CIGS BASED ON FCST SOUNDINGS. EXPECT SKIES TO SCT OUT BY MID AFTN AS DRIER AIR ARRIVES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 327 PM EDT WED AUG 1 2012 A LOW PRESSURE SYSTEM MOVING THROUGH SOUTHERN CANADA TODAY AND TONIGHT WILL SWEEP A COLD FRONT ACROSS LAKE SUPERIOR. EXPECT SW WINDS AHEAD OF THIS FRONT TO GUST TO 20KTS BEFORE SHIFTING TO THE NW TO 20KTS OVERNIGHT. A HIGH PRESSURE RIDGE WILL THEN SETTLE BACK OVER LAKE SUPERIOR THURS INTO FRI. A STRONGER LOW PRESSURE SYSTEM DEVELOPING NEAR LAKE WINNIPEG ON FRIDAY WILL SHIFT ENE TO JAMES BAY BY SUNDAY MORNING AND SWEEP A COLD FRONT ACROSS LAKE SUPERIOR ON SATURDAY. WINDS COULD GUST TO 25KTS THIS WEEKEND AS THE SYSTEM MOVES THROUGH. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...TITUS LONG TERM...KF AVIATION...JLA MARINE...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
128 AM EDT TUE JUL 31 2012 .SYNOPSIS... ISSUED AT 345 PM EDT MON JUL 30 2012 A COLD FRONT WILL SWEEP SOUTHEAST THROUGH MICHIGAN TONIGHT... BRINGING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. SOME OF THE STORMS MAY BE STRONG TO SEVERE WEST OF HIGHWAY 131. RAIN WILL END TUESDAY MORNING AS THE FRONT DEPARTS... WITH DECREASING CLOUDS FOLLOWING. STRONG NORTH WINDS BEHIND THE FRONT WILL CREATE HAZARDOUS SWIMMING AND BOATING CONDITIONS ON LAKE MICHIGAN FOR TUESDAY AFTERNOON AND EVENING. HIGH PRESSURE WILL PROVIDE DRY AND PLEASANT WEATHER ON WEDNESDAY... THEN ANOTHER COLD FRONT WILL BRING A THREAT OF SHOWERS AND THUNDERSTORMS ON THURSDAY. && .UPDATE... ISSUED AT 953 PM EDT MON JUL 30 2012 RADAR IS CURRENTLY LIT UP FROM THE BRIDGE SOUTHWEST TO NEAR MANITOWOC. NEW ECHOS WERE FORMING SW OF MANITOWOC ACROSS CENTRAL WISCONSIN AHEAD OF A COLD FRONT. LATEST HRRR BRINGS A BROKEN LINE OF STORMS ACROSS THE CWA LATE TONIGHT. SHEAR VALUES ARE CONSIDERABLY LESS ACROSS LOWER MI THAN ACROSS WISCONSIN. THINKING THAT CHCS OF SVR STORMS ARE DIMINISHING BASED ON TIME OF DAY AND MODEL PROGS OF SHEAR BUT A STRONG STORM OR TWO IS CERTAINLY POSSIBLE. TWEAKED POPS TO REFLECT A BIT SLOWER TIMING THROUGH THE CWA. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 345 PM EDT MON JUL 30 2012 THE MID LEVEL SHORTWAVE TROUGH NOW OVER THE LAKE SUPERIOR REGION WILL DIG SEWD TONIGHT. HEIGHT FALLS ASSOCIATED WITH THIS AMPLIFYING WAVE AND LOW LEVEL CONVERGENCE ASSOCIATED WITH THE SFC COLD FRONT WILL SET OFF A SCT-BKN LINE OF CONVECTION TO OUR NW OVER WI LATE THIS AFTERNOON. THIS ACTIVITY IS EXPECTED TO EASILY SURVIVE THE TREK ACROSS LAKE MI THIS EVENING AS AXIS OF INSTABILITY WITH MUCAPES AROUND 2000 J/KG LEANS INTO WRN LWR MI AHEAD OF THE FRONT. LAKE MI ACTUALLY MAY ALSO PROVIDE SOME BOOST GIVEN THE VERY WARM WATER TEMPS AND ADDED SOURCE OF MOISTURE. HAVE RAISED POPS TO LIKELY OVER MUCH OF THE CWFA TONIGHT. SOME WIND DAMAGE MAY OCCUR WITH ANY ORGANIZED/BOWING LINES OF CONVECTION TONIGHT. ALL THE JUICY DETAILS RELATED TO SEVERE WX POTENTIAL CAN BE FOUND IN THE SPC DAY1 OTLK AS WELL AS ANY MESOSCALE DISCUSSIONS FOR OUR AREA. BELIEVE MOST OF THE CONVECTION WILL EXIT TO THE SOUTHEAST ON TUESDAY MORNING. HOWEVER IT IS POSSIBLE SOME ENHANCEMENT AND/OR NEW DEVELOPMENT WILL TAKE PLACE NEAR JXN IN THE LATE MORNING PRIOR TO THE FRONT FULLY EXITING TO THE SE. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 345 PM EDT MON JUL 30 2012 THE FOCUS OF THE LONG TERM WILL BE ON TWO SYSTEMS THAT WILL BE MOVING THROUGH THE AREA. NO MAJOR CHANGES ARE NEEDED TO THE FCST AS THE MODELS HAVE BEEN FAIRLY CONSISTENT WITH DECENT RUN TO RUN CONTINUITY. UPPER NW FLOW EXPECTED TO BE ALOFT MOST OF THIS WEEK WILL HOLD ON FOR ONE MORE DAY ON THU/THU NIGHT AS A SOMEWHAT DISORGANIZED SHORT WAVE MOVES THROUGH JUST NORTH OF THE AREA. THIS WAVE WILL HELP TO PUSH A COLD FRONT SOUTH THROUGH THE AREA. MOST OF THE DYNAMICS WILL REMAIN JUST NORTH OF THE AREA WITH THIS WAVE. THE FRONT WILL BE WEAKENING AS IT PUSHES SOUTH THROUGH THE AREA. H850 TEMPS AROUND 20C WILL HELP TEMPS WARM TO AROUND 90 THU AFTERNOON. THE NW UPPER FLOW IS EXPECTED TO BEGIN FLATTENING OUT SOME THEN ON FRI. THIS OCCURS AS THE STRONG WAVE THAT COMES FROM ITS CURRENT POSITION ACROSS THE NRN PACIFIC TRANSLATES INTO THE AREA FOR NEXT WEEKEND. MODELS ARE STARTING TO INDICATE THAT A WAVE MAY RIDE ALONG THE STALLING OUT FRONT TO OUR SOUTH ON FRI. IF IT STALLS OUT A LITTLE FURTHER NORTH...FRI MAY END UP A BIT MORE WET THAN CURRENTLY INDICATED. MODELS HAVE BEEN INDICATING THAT SAT AND SAT NIGHT COULD BE A SOMEWHAT WET PERIOD AND POTENTIALLY ACTIVE AS THE STRONG WAVE/LOW WILL BEGIN MOVING INTO THE AREA. STRONG FORCING AHEAD OF IT...ALONG WITH A MOISTURE FEED FROM THE GULF WILL HELP TO BRING A GOOD CHC OF PCPN TO THE AREA. THE NEW 12Z EURO JUST COMING IN IS NOW SLOWING THE SYSTEM UP A BIT...SO WE WILL NEED TO WATCH THAT TREND. WE SHOULD CLEAR OUT RATHER WELL AND COOL OFF A BIT BEHIND THE SAT/SAT NIGHT SYSTEM AS A NICE CANADIAN AIR MASS ADVECTS IN. THIS WILL DOMINATE THE WEATHER FOR THE FIRST PART OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 121 AM EDT TUE JUL 31 2012 A LINE OF THUNDERSTORMS EXTENDING FROM MKG TO GRR AT 06Z WILL CONTINUE SOUTH AND EAST...AND SHOULD REACH JXN BY 09Z. SOME AREAS OF MVFR CAN BE EXPECTED ALONG AND BEHIND THIS LINE OF STORMS BUT VFR SHOULD RETURN BY 12Z AND CONTINUE THROUGH TUESDAY. && .MARINE... ISSUED AT 345 PM EDT MON JUL 30 2012 WILL ISSUE A SMALL CRAFT ADVISORY FOR TUESDAY AFTERNOON AND EVENING. INCREASING NORTH FLOW AND COLD ADVECTION OVER VERY WARM LAKE WATERS IS BOUND TO KICK UP THE LAKE TO ADVISORY LEVELS. && .HYDROLOGY... ISSUED AT 345 PM EDT MON JUL 30 2012 RAIN AMOUNTS WITH THE FRONT TONIGHT SHOULD BE GENERALLY ONE QUARTER TO ONE HALF INCH. HOWEVER SOME LOCALLY HIGHER AMOUNTS NEAR ONE INCH ARE CERTAINLY POSSIBLE. WHILE LOCALIZED NUISANCE FLOODING IS POSSIBLE IN URBAN AREAS IF/WHERE HEAVY DOWNPOURS OCCUR... WE REALLY NEED THIS RAIN FOR DROUGHT RELIEF. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM NOON EDT TODAY THROUGH LATE TONIGHT FOR MIZ037-043-050-056-064-071. LM...SMALL CRAFT ADVISORY FROM NOON TODAY TO 5 AM EDT WEDNESDAY FOR LMZ844>849. && $$ UPDATE...93 SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...NJJ AVIATION...OSTUNO HYDROLOGY...MEADE MARINE...MEADE
AREA FORECAST DISCUSSION
NWS DULUTH MN
740 PM CDT WED AUG 1 2012 .SHORT TERM... CURRENTLY...NO THUNDERSTORMS WERE OCCURRING OVER THE CWA. WE HAD A BRIEF STORM DEVELOP OVER SOUTHERN PINE COUNTY AROUND 2330Z IN AN AREA OF ENHANCED CU THAT HAS BEEN MOVING EAST OVER THE PAST COUPLE HOURS. STABILITY IS IMPRESSIVE THIS EVENING...WITH MUCAPE AROUND 3000J/KG OVER NORTHWEST WISCONSIN...TO A 1000 J/KG OVER THE INTERNATIONAL BORDER REGION. HOWEVER...LIFT IS QUITE MARGINAL WITH MID LEVEL ENERGY FURTHER NORTH AND WEST PASSING THROUGH SOUTHERN MANITOBA...AND STRONGER LOW LEVEL FGEN FORCING FURTHER SOUTH OVER SOUTHERN MINNESOTA INTO SOUTH DAKOTA. THERE IS SOME WEAK LOW LEVEL CONVERGENCE...SEEN IN THE SURFACE OBS...WITH W-NW FLOW AT KRZN/KDLH/K04W AND LIGHT SW FLOW AT KPBH AND KASX. THE RAP SHOWS LITTLE 925MB CONVERGENCE. WE CAN`T RULE OUT A THUNDERSTORM OVER THE NEXT FEW HOURS OVER NORTHWEST WISCONSIN AS THE WEAK LOW LEVEL CONVERGENCE MOVES THROUGH. WE ALSO COULD GET BRUSHED WITH THE COMPLEX OF STORMS THAT WERE AFFECTING SOUTHERN/CENTRAL MN AND SOUTH DAKOTA AS IT CONTINUES E-SE. HOWEVER...CHANCES OF THAT ARE LOW. FURTHER NORTH...A SHORTWAVE SEEN ON SATELLITE AND IN THE RAP`S 1.5 PV SURFACE...WILL AFFECT FAR NORTHERN MINNESOTA AND COULD BRING A FEW SHOWER OR STORMS TO THAT AREA LATER THIS EVENING. WE MAY HAVE TO EXTEND AND EVEN INCREASE POPS A BIT AFTER 03Z IN THE FAR NORTH. .PREV DISCUSSION... /ISSUED 626 PM CDT WED AUG 1 2012/ AVIATION.../0Z TAF ISSUANCE/ COLD FRONT HAS MOVED THROUGH THE TERMINALS WITH NORTHWESTERLY WINDS. MAIN AREA OF SHOWER AND THUNDERSTORM ACTIVITY WILL STAY TO OUR SOUTH. HAVE INCLUDED SOME TEMPO GROUPS TO ACCOUNT FOR THE DEVELOPMENT OF PATCHY FOG BEFORE DAWN. VISIBILITIES MAY FALL TO 1SM AT HIB...DLH...AND HYR. WINDS WILL STAY LIGHT NORTHWESTERLY THROUGH THE TAF FORECAST PERIOD. PREV DISCUSSION... /ISSUED ISSUED BY NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN/ DISCUSSION... PRIMARY FORECAST CONCERNS ARE CHANCES FOR TSRA THIS LATE THIS AFTERNOON INTO THIS EVENING AS THE COLD FRONT MOVES THROUGH THE REMAINDER OF THE AREA... THEN CHANCES FOR MORE WIDESPREAD SHRA/TSRA FRIDAY NIGHT INTO SATURDAY MORNING AS THE NEXT SHORTWAVE AND COLD FRONT MOVE THROUGH THE AREA. LATEST WATER VAPOR IMAGERY SHOWS THE SAME BASIC UPPER AIR PATTERN WE/VE SEEN FOR MUCH OF THE SUMMER... WITH A BROAD UPPER RIDGE ENCOMPASSING MOST OF THE CENTRAL CONUS. THE SHORTWAVE CURRENTLY RIDING ALONG THE US/CANADIAN BORDER NEAR THE MONTANA/NORTH DAKOTA BORDER WILL CONTINUE TO DRIVE EAST TONIGHT... HELPING TO FINALLY PUSH THE COLD FRONT CURRENTLY OVER MINNESOTA EAST THROUGH THE REMAINDER OF THE AREA. SPC MESOANALYSIS SHOWS GOOD INSTABILITY ALONG AHEAD OF THE FRONT... WITH MLCAPE AOA 2500 J/KG. SOME INSTABILITY LAGS THE SURFACE BOUNDARY AS WELL... WHICH IS HELPING TO KEEP ACTIVITY GOING TO THE WEST... AND NECESSITATES LEAVING POPS IN THE FORECAST ACROSS THE AREA THROUGH AT LEAST EARLY EVENING AS THE UPPER WAVE MOVES TOWARD THE FORECAST AREA. WE SHOULD MANAGE TO CLEAR THE PCPN OUT OF ALL BUT PERHAPS THE SOUTHEAST PORTION OF THE AREA OVERNIGHT AS THE FRONT CONTINUES EAST AND A WEAK SURFACE RIDGE TRIES TO WORK INTO THE AREA. THERE COULD BE SOME AREAS OF FOG LATE TONIGHT WITH WINDS DYING AND CLOUD COVER DECREASING... BUT THAT WILL LIKELY DEPEND ON ANY RE-WETTING OF THE GROUND WHICH CAN OCCUR WITH PCPN THROUGH EARLY THIS EVENING... SO OPTED TO LEAVE IT OUT OF THE FORECAST FOR NOW. IT SHOULD BE PARTLY CLOUDY AND DRY OVER MOST OF THE AREA ON THURSDAY AS THE SURFACE HIGH DRIFTS ACROSS THE AREA. HOWEVER... THE ARROWHEAD COULD SEE SOME AFTERNOON PCPN DEVELOP GIVEN BETTER PROXIMITY TO THE MID-LEVEL COLD POOL MOVING NORTH AND NORTHEAST OF THE AREA DURING THE DAY. AFTER TOMORROW ATTENTION WILL TURN TOWARD THE SHORTWAVE CURRENTLY DROPPING THROUGH BRITISH COLUMBIA. THIS WAVE IS EXPECTED TO CONTINUE EAST-SOUTHEAST THROUGH THE NEXT FEW DAYS... WORKING INTO THE HIGH PLAINS BY FRIDAY... THEN CONTINUING EAST ACROSS THE FORECAST AREA SATURDAY INTO SUNDAY. DECENT RETURN FLOW AND WARM ADVECTION IS EXPECTED AHEAD OF THIS FEATURE... AND THE NAM... GFS... AND ECMWF ARE ARE IN REASONABLY AGREEMENT ON THE DEGREE OF INSTABILITY AND FORCING ASSOCIATED WITH ITS PASSAGE. THERE ARE STILL SOME TIMING DIFFERENCES... WHICH RESULT IN HAVING A LONGER PERIOD BLANKETED WITH POPS THAN WILL LIKELY OCCUR... BUT AS THINGS GET CLOSER IN TIME THOSE WILL BE REFINED AND LIKELY INCREASED FOR THE FROPA AND SHORTWAVE ARRIVAL WHICH CURRENTLY LOOKS TO OCCUR FRIDAY NIGHT INTO SATURDAY MORNING. INCLUDED CHANCE-LIKELY POPS WITH THIS SYSTEM FRIDAY NIGHT INTO SATURDAY... THEN TAPERED THING BACK SATURDAY NIGHT AS THE FRONT MOVES WELL TO THE EAST BUT CYCLONIC BOUNDARY LAYER FLOW AND AND MID-UPPER COLD POOL LINGER OVER THE AREA. IMPRESSIVE RIDGING LOOKS TO ARRIVE AND KEEP THINGS BENIGN SUNDAY THROUGH MONDAY... WITH A SMALL CHANCE FOR SOME PCPN MONDAY NIGHT AS A WEAK FRONTAL BOUNDARY DROPS SOUTH THROUGH THE AREA. THE MAIN CHANCES LOOK TO BE OVER THE SOUTHERN PORTION OF THE AREA WITH THAT FEATURE... SINCE IT APPEARS IT WILL TAKE A WHILE FOR THINGS TO SATURATE IF THEY DO AT ALL GIVEN THE DRYNESS OF THE ANTECEDENT AIRMASS. PCPN CHANCES SHOULD RETURN BY THE MIDDLE OF THE WEEK AS WE GET ONTO THE BACKSIDE OF THE SURFACE HIGH AND A FEW SHORTWAVES DROP SOUTHEAST INTO THE AREA ON THE PREVAILING NORTHWEST FLOW. && .POINT TEMPS/POPS... DLH 64 79 60 78 / 30 10 10 30 INL 60 79 60 78 / 20 10 20 50 BRD 63 84 62 84 / 20 10 10 50 HYR 64 82 60 82 / 40 10 10 20 ASX 66 77 61 78 / 30 10 0 20 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1244 AM CDT TUE JUL 31 2012 .UPDATE... ISSUED AT 1236 AM CDT TUE JUL 31 2012 CLEARING SKIES...LIGHT WIND...AND DEWPOINTS IN THE LOWER 70S HAS LED TO SOME PATCHY FOG DEVELOPMENT. MANY STATIONS ACROSS THE AREA ALREADY REPORTING 4-6SM. HAVE UPDATED THE SHORT TERM FORECAST TO INCLUDE PATCHY FOG THROUGH DAYBREAK. CVKING && .SHORT TERM... ISSUED AT 344 PM CDT MON JUL 30 2012 (TONIGHT) EXTENSIVE AREA OF MID AND HIGH CLOUDS HAVE HELPED HOLD TEMPERATURES BACK OVER MOST OF THE REGION TODAY. SURFACE REPORTS FROM THE LARGE AREA OF RETURNS ON RADAR ARE MAINLY SPRINKLES. THIS IS BEING GENERATED BY A VORT MAX THAT WILL MOVE SOUTH INTO THE SOUTHERN CWA BY 00Z. THERE IS LITTLE LOW LEVEL FORCING ASSOCIATED WITH IT ACCORDING TO THE RAP UNTIL AFTER 00Z...AND EVEN THEN IT IS QUITE WEAK. THINK GOING SLIGHT CHANCES FOR SHOWERS/THUNDERSTORMS STILL LOOKS OKAY GIVEN SLIGHTLY BETTER LOW LEVEL FORCING AND MORE INSTABILITY. OTHERWISE CHANCES SHOULD DECREASE WITH TIME AS THE LOW MOVES FARTHER SOUTH. BRITT && .LONG TERM... ISSUED AT 344 PM CDT MON JUL 30 2012 (TUESDAY THROUGH NEXT MONDAY) MAIN CONCERN ONCE AGAIN IS HEAT. HAVE ISSUED A HEAT ADVISORY JUST FOR THE ST. LOUIS METRO AREA ON TUESDAY AFTERNOON AS IT CURRENTLY LOOKS LIKE HEAT INDEX READINGS WILL CLIMB TO AROUND 105 DURING THE AFTERNOON. GFS/NAM ARE IN RELATIVELY GOOD AGREEMENT THAT A WEAK COLD FRONT WILL BE MOVING SOUTH OUT OF THE UPPER MIDWEST INTO NORTHERN MISSOURI AND CENTRAL ILLINOIS AROUND MIDDAY TOMORROW. DO NOT EXPECT MUCH CLOUDS AND ANY RAIN CHANCES WITH THIS FRONT AS WE WILL LIE UNDER SUBSIDENCE BETWEEN A SHORTWAVE TROUGH MOVING THROUGH THE GREAT LAKES AND A VORT MAX MOVING ACROSS SOUTHWEST MISSOURI. NAM FORECAST SOUNDINGS SHOWING DEEP MIXING TO 700MB AHEAD OF THE FRONT WHICH SUPPORTS GOING HIGHS WHICH ARE CLOSE TO THE NAM MOS TEMPERATURES WHICH HAVE VERIFIED BETTER THIS SUMMER. DEWPOINTS SHOULD FALL INTO THE UPPER 50S TO LOWER 60S WITH THE MIXING...WHICH COMBINED WITH HIGHS RISING TO AROUND 104 RESULT IN HEAT INDEX HIGHS BRIEFLY REACHING 105 TOMORROW AFTERNOON. TEMPERATURES ON WEDNESDAY LOOK TO BE NOT AS WARM BEHIND THE FRONT...SO HEAT INDEX READINGS ARE EXPECTED TO STAY BELOW 100 DEGREES. ANOTHER FRONT MOVES INTO NORTHERN MISSOURI LATE THURSDAY/THURSDAY NIGHT...WITH THE GFS BRINGING IT THROUGH THE AREA AND THE ECMWF KEEPING IT STALLED TO THE NORTH AS THE UPPER FLOW BECOMES ZONAL. HAVE GONE WITH JUST A SLIGHT CHANCE FOR SHOWERS/STORMS ON THURSDAY AND TEMPERATURES IN THE UPPER 90S WHICH SHOULD RESULT IN HEAT INDEX READINGS BETWEEN 98-103. GENERALLY STAYED WITH THE ECMWF OVER THE WEEKEND. SHOULD BE SOME INCREASE IN LOW LEVEL FORCING AHEAD OF A COLD FRONT THAT WILL MOVE ACROSS THE AREA ON SUNDAY...SO HAVE KEPT A CHANCE OF SHOWERS AND THUNDERSTORMS GOING AHEAD OF IT. WITH 850MB TEMPS STAYING ABOVE 20C...HIGH TEMPERATURES SHOULD REMAIN ABOVE 90 THROUGH THE PERIOD. BRITT && .AVIATION... ISSUED AT 1021 PM CDT MON JUL 30 2012 MID LEVEL CLOUDINESS OVER SRN AND W CNTRL MO WILL CONTINUE TO DROP SWD LATE TGT...LIKELY ONLY IMPACTING COU TIL 06-07Z TUE...AND REMAINING S-SW OF THE OTHER TAF SITES. SFC WINDS WILL BE LIGHT TGT AS WEAK SFC RIDGE CENTERED OVER NERN MO SHIFTS SEWD. DUE TO THE CLEARING SKY THIS EVNG ALONG WITH HIGH SFC DEWPOINTS AND LIGHT WINDS THERE SHOULD BE SOME LIGHT PATCHY FOG LATE TGT AND EARLY TUE MRNG WITH VSBYS DROPPING DOWN TO AROUND 3-5 MILES. A WEAK COLD FRONT NOW OVER THE GREAT LAKES AND NRN PLAINS REGIONS WILL DROP SEWD THROUGH OUR AREA ON TUE. ONLY ISOLATED SHOWERS/STORMS EXPECTED ALONG THIS FRONT IN OUR AREA SO WILL LEAVE THE TAFS DRY FOR NOW...PLUS LITTLE CLOUD COVER EXPECTED ON TUE. NWLY SFC WINDS WILL INCREASE TUE AFTN AFTER FROPA...THEN BECOME N-NELY TUE EVNG AS A SFC RIDGE BUILDS SEWD INTO THE GREAT LAKES REGION BEHIND THE COLD FRONT. SPECIFICS FOR KSTL...THE MID LEVEL CLOUD DECK HAS RECENTLY SHIFTED S OF STL THIS EVNG AND SHOULD REMAIN S-SW THE REMAINDER OF THE NIGHT WITH LITTLE CLOUD COVER EXPECTED FOR THE REST OF THE TAF PERIOD. LIGHT SFC WINDS LATE TGT AND TUE MRNG COULD LEAD TO LIGHT FOG OR HAZE LATE TGT AND EARLY TUE MRNG OF AROUND 5SM. THE SFC WIND WILL INCREASE TO AROUND 10 KTS TUE AFTN FROM A NWLY DIRECTION AFTER PASSAGE OF A WEAK COLD FRONT. COULD BE ISOLATED SHOWERS/STORMS ALONG THIS FRONT IN THE ST LOUIS METRO AREA...BUT WILL LEAVE STL TAF DRY FOR NOW AS CONVERGENCE ALONG FRONT SHOULD BE WEAK AND ANY SIGNIFICANT MOISTURE SHOULD BE THIN OR SHALLOW. THE SFC WIND SHOULD WEAKEN TUE NGT AND BECOME MORE NELY. GKS && .LSX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR JEFFERSON MO-ST. CHARLES MO-ST. LOUIS CITY MO-ST. LOUIS MO. IL...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR MADISON IL-MONROE IL-ST. CLAIR IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
931 PM MDT WED AUG 1 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY... EVENING UPDATE... UPDATE FOR THIS EVENING WAS BASED AROUND BRINGING WINDS UP TO SPEED WITH THE HRRR MODEL WHICH APPEARS TO BE THE BEST AT BEST AT CATCHING THE LOCAL SURFACE TROUGH SETTING OVER THE REGION. HAVE ALSO ADAPTED THE OVERNIGHT LOWS TO THE NAMBC AND SREFBC WHICH SEEM TO CATCH LARGE SCALE SOUTHWEST TO ZONAL FLOW CHANGE THE BEST OVERNIGHT. GAH PREVIOUS SHORT TERM DISCUSSION... A CLASH OF AIRMASSES ARE OCCURRING ACROSS THE NORTHERN ZONES THIS AFTERNOON WITH A WARM/DRY AIRMASS MOVING IN FROM THE SOUTH WHILE A NW PUSH HAS MOVED INTO THE NW ZONES. COOLER/MORE HUMID AIRMASS HAVE BEEN OVER THE EASTERN ZONES TODAY. A SEVERE THUNDERSTORM DEVELOPED ON THE TRIPLE POINT IN SOUTHERN SASK NEAR SWIFT CURRENT ABOUT NOON AND IS MOVING SOUTHEAST...POISED TO POSSIBLY BRING SEVERE WEATHER OVER THE NE ZONES FOR THE REMAINDER OF THE AFTERNOON. THE WARM AND DRY AIRMASS WILL BE BEST ESTABLISHED OVER THE SW ZONES BUT LIGHT WINDS AND HIGHER HUMIDITY WILL BE IN PLACE OVER THE EASTERN ZONES. SURFACE LOW PRESSURE OVER S SASK WILL DRAG A COLD FRONT EAST ACROSS THE AREA AND FIRE UP AFTERNOON THUNDERSTORMS NEAR THE NORTH DAKOTA BORDER. THEN THE NEXT BIG SYSTEM WILL BE DROPPING IN FROM THE NORTHWEST. CLOUDS OVERSPREAD THE AREA THURSDAY NIGHT WITH RAINSHOWERS TO ARRIVE FRIDAY. TEMPS WILL BE SIGNIFICANTLY COOLER WITH HIGHS ABOUT 15 DEGREES BELOW NORMAL. JAMBA .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY... JUST FEW SLIGHT CHANGES TO THE EXTENDED FORECAST BY SLIGHTLY ADJUSTING THE POPS FOR SATURDAY AND THEN AGAIN ON MONDAY NIGHT AND TUESDAY. THERE IS STILL NOT MUCH IN THE WAY OF MODEL AGREEMENT SO THE EXTENDED MODELS SEEM TO BE DIFFERING ON SOLUTIONS FROM THE 12Z TO THE OOZ RUN. THE ECMWF IS TRYING TO SHOW SOME KIND OF BLOCKING PATTERN FROM MONDAY THROUGH WEDNESDAY WHILE THE GFS SHOWS A LARGE RIDGE OVER THE NORTHERN ROCKIES. RSMITH PREVIOUS DISCUSSION...SYNOPTIC SET UP... A LARGE TROUGH OF COOLER AIR HAS FORMED AS A SPUR OFF THE HUDSON BAY LOW AND COMBINED A WITH A SHORTWAVE MEANDERING DOWN FROM CENTRAL ALBERTA. THIS SHOULD SPILL COOL AIR AND SHOWERS INTO SOUTHERN SASKATCHEWAN AND NORTHEAST MONTANA THEN SLOWLY EXIT TOWARD THE DAKOTAS. TO THE SOUTH A SUPPRESSED DOME OF HOT HIGH PRESSURE SETS OVER THE DESERT SOUTHWEST AND REACHES UP TO ABOUT CENTRAL WYOMING. A LARGE RIDGE EXTENDS UP FROM THIS DOME THROUGH THE PACIFIC NORTHWEST... BRITISH COLUMBIA... AND INTO THE NORTHWEST TERRITORIES. FRIDAY NIGHT... THE TROUGH OF COOLER AIR WILL BEGIN EXITING THE AREA AS SOME WRAP AROUND PRECIP DROPS DOWN BRIEFLY ACROSS THE NORTHERN SECTIONS OF THE CWA. NOT ANTICIPATING VERY MUCH RAIN AND RAIN SHOULD ALSO BE HIT OR MISS FOR AREAS THAT DO EXPERIENCE IT. THE HEAT DOME WILL BEGIN TO BUILD INTO THE PACIFIC NORTHWEST AS THE TROUGH EXITS TO THE EAST. SATURDAY THROUGH MONDAY... ANTICIPATED NORTHWEST FLOW PATTERN TO SLOWLY TRANSITION TO A RIDGE AS IT ARRIVES. CONDITIONS SHOULD REMAIN DRY THROUGH THIS SET OF PERIODS. WITH A SLOW WARMING PATTERN THAT SHOULD SPIKE SUNDAY NIGHT OR MONDAY MIDDAY. MONDAY NIGHT ONWARD... MODELS CONFIDENCE BREAKS DOWN AT THIS POINT. 12Z EC WANTS TO PLACE US IN SOUTHWEST FLOW AS A HEAT DOME BREAKS DOWN ACROSS THE FAR WESTERN PART OF THE CONTINENT AND A COLD PUSH ARRIVES FROM THE CANADIAN PLAINS AGAIN. HOWEVER THE 12Z EC APPEARS TO GIVE NO REASONING FOR THE HEAT DOME BREAKDOWN ACROSS THE FAR WEST. THEREFORE I`M MORE INCLINED TO AGREE WITH THE 00Z GFS WHICH MAINTAINS THIS DOME AND PLACES NEMONT BACK IN DRIER NORTHWESTERN FLOW. NEWER 00Z EC ALSO APPEARS TO HAVE PULLED INTO THIS LINE OF LOGIC AS WELL. THE STRENGTH OF THE COLD CANADIAN PLAINS PUSH IS ALSO UNKNOWN AND THEREFORE COULD BE WARMER DRIER AND LESS WINDY... OR COOLER MORE UNSTABLE AND WINDY DEPENDING ON THE TRUE ORIGIN OF THE AIRMASS. HAVE SPLIT THE DIFFERENCE FOR NOW THROUGH TUESDAY NIGHT. WEDNESDAY TOWARD THE END WILL VERY LIKELY TRANSITION BACK TO A RIDGE IF THE HEAT DOME TO THE WEST REMAINS UP. GAH && .AVIATION... VFR. WINDS TONIGHT WILL BE LIGHT AND VARIABLE. A DRY COLD FRONT WILL PUSH THROUGH THURSDAY AFTERNOON. SOUTH TO WEST WINDS WILL INCREASE DURING THE LATE MORNING AND AFTERNOON...WITH WINDS GOING NORTHWESTERLY AT 15 TO 25 KTS BEHIND THE FRONT BY THE LATE AFTERNOON AND OVERNIGHT THURSDAY NIGHT. WEAK CONVECTION MAY POP UP THURSDAY AFTERNOON...WITH GUSTY ERRATIC WINDS POSSIBLE NEAR ANY STORMS THAT DEVELOP. CLEAR SKIES WILL BE PRESENT OVERNIGHT TONIGHT...WITH SOME MIDLEVEL CUMULUS DEVELOPING THURSDAY AFTERNOON. GILCHRIST && .GLASGOW WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON THURSDAY TO 6 AM MDT FRIDAY FOR MTZ136-137. FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT FOR MTZ120-122-134-135. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
930 PM MDT WED AUG 1 2012 .SHORT TERM...VALID FOR THU AND FRI... UPDATE TO FORECAST TO REMOVE POPS FROM THE E AND NW THIS EVENING. CONVECTION HAS BEEN CONFINED TO THE SW MOUNTAINS THIS EVENING PER RADAR IMAGERY. A WEAK BACKDOOR COLD FRONT WAS PUSHING S THROUGH NE MT AS EVIDENCED BY A REFLECTIVITY BOUNDARY ON RADAR. BOTH THE WRF AND RAP SHOWED THE BOUNDARY HANGING UP JUST TO THE N OF THE FORECAST AREA EARLY THU MORNING AS IT ENCOUNTERS FLOW FROM A SURFACE LOW OVER N CENTRAL WY. NEITHER MODEL SHOWED CONVECTION DEVELOPING ALONG THE BOUNDARY INTO THU MORNING. THE CONVECTION OVER THE SW MOUNTAINS WILL DISSIPATE WITH LOSS OF HEATING LATER THIS EVENING. THE NEXT CHANCE OF CONVECTION WILL BE ALONG A CONVERGENCE ZONE N OF THE WY LOW THU AFTERNOON OVER SE MT. NO CHANGES NEEDED TO REMAINDER OF FORECAST. ARTHUR .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... UPPER-LEVEL RIDGING WILL PREVAIL THIS WEEKEND. EXPECT DRY CONDITIONS AND A WARMING TREND. LIFT/MOISTURE WILL INCREASE BY THE START OF THE WORK WEEK. BROAD-BRUSHED LOW POPS MONDAY NIGHT THROUGH EARLY THURSDAY. TEMPERATURES WILL COOL DOWN TO SEASONAL VALUES DURING THE WEEK. BLENDED POP FORECASTS WITH ALLBLEND GUIDANCE. BLENDED MAX/MIN TEMPERATURE FORECASTS WITH THE BEST- PERFORMING 12Z GUIDANCE...BCALLBLEND / BCCONSMOS RESPECTIVELY. BRS && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD. ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP ALONG THE MONTANA/DAKOTA BORDER DURING THU AFTERNOON/EVENING. SOME OF THESE STORMS COULD BECOME SEVERE WITH BRIEF LOCAL IFR CONDITIONS. BT && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 063/093 061/076 050/084 059/094 063/094 064/092 063/088 11/U 14/T 11/U 11/U 11/B 22/T 22/T LVM 052/089 051/075 042/085 051/092 054/092 054/090 053/086 11/N 13/T 11/U 11/U 11/B 22/T 22/T HDN 059/096 059/078 047/085 054/095 059/096 059/094 059/090 11/U 14/T 11/U 11/U 11/B 22/T 22/T MLS 065/093 065/079 052/083 059/095 066/096 066/093 065/089 11/B 25/T 11/U 01/U 11/U 22/T 32/T 4BQ 062/096 062/079 049/082 056/094 062/096 062/094 062/089 11/U 14/T 11/U 01/U 11/U 22/T 22/T BHK 061/093 062/077 048/079 055/092 061/093 062/091 062/086 12/T 25/T 21/B 01/U 11/U 22/T 22/T SHR 058/095 060/077 046/082 053/092 058/094 059/091 058/088 11/N 13/T 11/U 01/U 11/B 22/T 22/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...RED FLAG WARNING IN EFFECT FROM 2 PM THURSDAY TO MIDNIGHT MDT THURSDAY NIGHT FOR ZONE 117. RED FLAG WARNING IN EFFECT FROM 2 PM THURSDAY TO 8 PM MDT FRIDAY FOR ZONES 123>132. FIRE WEATHER WATCH IN EFFECT FROM THURSDAY EVENING THROUGH FRIDAY EVENING FOR ZONE 133. WY...RED FLAG WARNING IN EFFECT FROM 2 PM THURSDAY TO 8 PM MDT FRIDAY FOR ZONES 274-284. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1004 PM CDT WED AUG 1 2012 .UPDATE... DID AN EVENING UPDATE A LITTLE EARLIER TO ACCOUNT FOR HIGHER POPS IN THE NORTHEAST AND CONTINUED SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FARTHER SOUTHEAST OVERNIGHT. && .DISCUSSION... THE EVENING OAX SOUNDING WAS ON THE DRY SIDE WITH LESS THAN ONE INCH PRECIP WATER...LBF HOWEVER HAD A MUCH MORE FAVORABLE SOUNDING WITH AROUND 3200 J/KG FOR CAPE AND LITTLE CINH AND 1.34 FOR PRECIP WATER. THE MOISTURE TRANSPORT VECTORS CONTINUE TO BRING THE MOISTURE EASTWARD AND SOUTHWARD...SO SCATTERED POPS STILL SEEM ON TRACK. GUSTY WINDS ARE POSSIBLE WITH DOWNDRAFT CAPE OF 1800 J/KG. SO FAR HAVE HAD REPORTS OF 40 TO 50 MPH NEAR NELIGH. THE NEW NAM TRIES TO HOLD ON TO THE PRECIPITATION THURSDAY MORNING FARTHER NORTH SO THIS WILL NEED TO BE ASSESSED. && .PREV DISCUSSION... /ISSUED 715 PM CDT WED AUG 1 2012/ AVIATION... AVIATION... 00Z TAFS FOR KOMA...KLNK...AND KOFK. SHRA/TSRA AND WINDS ASSOCIATED WITH THIS PRECIPITATION WILL BE THE PRIMARY CONCERN OVERNIGHT. TSRA HAVE BEEN MOVING THROUGH WESTERN AND WEST CENTRAL NEBRASKA. STRONG WINDS OF 50 TO 60 MPH HAVE BEEN OCCURRING WITH SOME OF THE STORMS AND SOME DIME-SIZED HAIL. INCLUDED A FEW HOURS OF SHRA AT EACH SITE BETWEEN 06Z AND 11Z ALONG WITH SOME GUSTY WINDS OF 25-35KTS. WILL NEED TO MONITOR SPEED/MOVEMENT AND HOW THEY HOLD TOGETHER TO ADD IN TSRA AND STRONGER WINDS AS NECESSARY. THERE HAS ALREADY BEEN AN INCREASE IN SPEED OF THE LINE AND STORMS MAY MAKE IT TO KOFK EARLIER. VFR CONDITIONS WILL PREVAIL HOWEVER SOME MVFR CIGS/VSBYS ARE POSSIBLE STORMS. PREV DISCUSSION... /ISSUED 501 PM CDT WED AUG 1 2012/ DISCUSSION... IT APPEARS THAT A SHORT REPRIEVE FROM THE OPPRESSIVE DRY CONDITIONS THAT HAVE PLAGUED US AS OF LATE IS ON THE HORIZON AS A COUPLE OF COLD FRONTS APPROACH THE PLAINS. RADAR LOOP WAS SHOWING PCPN ACTIVITY OVER WESTERN NEBRASKA AND PARTS OF SOUTH DAKOTA WHILE LATEST OBS WERE DEPICTING A BNDRY EXTENDING ALONG THE ND/SD BORDER WITH CAA SLOWLY SPREADING SWD OVER NRN SD. THE BIG QUESTION IS WILL THIS RESULT IN PCPN OVER THE CWA LATER TONIGHT. IT SEEMS THE MODELS ARE TRYING TO STALL THE FRONT IN THE VICINITY OF THE NRN CWA...BUT GOOD CHUNK OF DPVA DOES CROSS THE CWA...AND WITH STOUT 315K UPGLIDE NOT UNREASONABLE AT THIS POINT TO EXPECT SOME HIGH BASED ACTIVITY DEVELOPING. LATEST HRRR SEEMS TO HAVE A DECENT HANDLE ON THINGS... WHICH SUGGEST ACTIVITY COULD GET INTO EASTERN NEBRASKA BEFORE MIDNIGHT. CHANCES FOR ANOTHER ROUND PCPN ARE ON TAP HEADING INTO THE WEEKEND. MODELS ARE IN VERY GOOD AGREEMENT THAT UPSTREAM SHORTWAVE TROF OVER BRITISH COLUMBIA WILL SLIGHTLY BREAK DOWN THE CONUS UPPER RIDGE AS IT DROPS INTO THE LOWER 48. THE THERMAL GRADIENT WITH THE ATTENDANT COLD FRONT WILL BE MORE STOUT IN NATURE. WITH DECENT ENVIRONMENTAL MOISTURE ON HAND... PRECIP WATER VALUES AROUND 2"/KI OF 40...IS REASONABLE TO MAINTAIN POPS FRIDAY NIGHT. POSSIBLE LINGERING ACTIVITY THEN SATURDAY MORNING OVER THE SRN CWA. RELATIVELY COOLER AFTN HIGHS IN THE MID 80S THEN SUNDAY AFTERNOON. HEADING INTO NEXT WEEK...THE SITUATION LOOKS RATHER BLEAK WITH DRY CONDITIONS AND HIGH TEMPS PUSHING BACK TO THE MID/UPPER 90S AS AN UPPER RIDGE RETURNS OVER THE CONUS. DEE/BCM && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
715 PM CDT WED AUG 1 2012 .AVIATION... AVIATION... 00Z TAFS FOR KOMA...KLNK...AND KOFK. SHRA/TSRA AND WINDS ASSOCIATED WITH THIS PRECIPITATION WILL BE THE PRIMARY CONCERN OVERNIGHT. TSRA HAVE BEEN MOVING THROUGH WESTERN AND WEST CENTRAL NEBRASKA. STRONG WINDS OF 50 TO 60 MPH HAVE BEEN OCCURRING WITH SOME OF THE STORMS AND SOME DIME-SIZED HAIL. INCLUDED A FEW HOURS OF SHRA AT EACH SITE BETWEEN 06Z AND 11Z ALONG WITH SOME GUSTY WINDS OF 25-35KTS. WILL NEED TO MONITOR SPEED/MOVEMENT AND HOW THEY HOLD TOGETHER TO ADD IN TSRA AND STRONGER WINDS AS NECESSARY. THERE HAS ALREADY BEEN AN INCREASE IN SPEED OF THE LINE AND STORMS MAY MAKE IT TO KOFK EARLIER. VFR CONDITIONS WILL PREVAIL HOWEVER SOME MVFR CIGS/VSBYS ARE POSSIBLE STORMS. && .PREV DISCUSSION... /ISSUED 501 PM CDT WED AUG 1 2012/ DISCUSSION... IT APPEARS THAT A SHORT REPRIEVE FROM THE OPPRESSIVE DRY CONDITIONS THAT HAVE PLAGUED US AS OF LATE IS ON THE HORIZON AS A COUPLE OF COLD FRONTS APPROACH THE PLAINS. RADAR LOOP WAS SHOWING PCPN ACTIVITY OVER WESTERN NEBRASKA AND PARTS OF SOUTH DAKOTA WHILE LATEST OBS WERE DEPICTING A BNDRY EXTENDING ALONG THE ND/SD BORDER WITH CAA SLOWLY SPREADING SWD OVER NRN SD. THE BIG QUESTION IS WILL THIS RESULT IN PCPN OVER THE CWA LATER TONIGHT. IT SEEMS THE MODELS ARE TRYING TO STALL THE FRONT IN THE VICINITY OF THE NRN CWA...BUT GOOD CHUNK OF DPVA DOES CROSS THE CWA...AND WITH STOUT 315K UPGLIDE NOT UNREASONABLE AT THIS POINT TO EXPECT SOME HIGH BASED ACTIVITY DEVELOPING. LATEST HRRR SEEMS TO HAVE A DECENT HANDLE ON THINGS... WHICH SUGGEST ACTIVITY COULD GET INTO EASTERN NEBRASKA BEFORE MIDNIGHT. CHANCES FOR ANOTHER ROUND PCPN ARE ON TAP HEADING INTO THE WEEKEND. MODELS ARE IN VERY GOOD AGREEMENT THAT UPSTREAM SHORTWAVE TROF OVER BRITISH COLUMBIA WILL SLIGHTLY BREAK DOWN THE CONUS UPPER RIDGE AS IT DROPS INTO THE LOWER 48. THE THERMAL GRADIENT WITH THE ATTENDANT COLD FRONT WILL BE MORE STOUT IN NATURE. WITH DECENT ENVIRONMENTAL MOISTURE ON HAND... PRECIP WATER VALUES AROUND 2"/KI OF 40...IS REASONABLE TO MAINTAIN POPS FRIDAY NIGHT. POSSIBLE LINGERING ACTIVITY THEN SATURDAY MORNING OVER THE SRN CWA. RELATIVELY COOLER AFTN HIGHS IN THE MID 80S THEN SUNDAY AFTERNOON. HEADING INTO NEXT WEEK...THE SITUATION LOOKS RATHER BLEAK WITH DRY CONDITIONS AND HIGH TEMPS PUSHING BACK TO THE MID/UPPER 90S AS AN UPPER RIDGE RETURNS OVER THE CONUS. DEE/BCM && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1234 AM CDT TUE JUL 31 2012 .AVIATION... THE THUNDERSTORM SYSTEM THAT DEVELOPED IN EASTERN COLORADO REMAINED OVER EXTREME SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. SHORT RANGE PROJECTIONS INDICATE THAT SHOWERS AND THUNDERSTORMS MAY DEVELOP OVER NORTHWEST NEBRASKA NORTH AND WEST OF A VTN-MHN-AIA LINE. THE PROBABILITY OF ANY AT VTN OR MHN IS VERY LOW. IN THE LAST PART OF THE FORECAST PERIOD...18-21Z...THUNDERSTORMS MAY DEVELOP SOUTH AND WEST OF AIA-TIF-LBF. AGAIN...THE PROBABILITY IS TOO LOW TO WARRANT INCLUSION IN THE TERMINAL FORECASTS FOR VTN AND LBF. && .PREV DISCUSSION... /ISSUED 643 PM CDT MON JUL 30 2012/ AVIATION... A FEW THUNDERSTORMS CAN BE EXPECTED THIS EVENING OVER THE NEBRASKA PANHANDLE AND NORTHWEST NEBRASKA...NORTH AND WEST OF AN ONL-IML LINE WITH THE HIGHEST PROBABILITY NORTH AND WEST OF AN ANW-OGA LINE. THE THUNDERSTORM PROBABILITY IS LESS THAN 30 PERCENT OVER EITHER AREA AND...FOR THE TIME BEING...WILL NOT BE INCLUDED IN THE TERMINAL FORECASTS FOR VTN AND LBF. OTHERWISE...SOME HIGH-BASED CUMULUS CLOUDS ARE EXPECTED ALONG WITH CIRROSTRATUS AND NO OTHER FLIGHT RESTRICTIONS ARE EXPECTED. && .PREV DISCUSSION... /ISSUED 333 PM CDT MON JUL 30 2012/ DISCUSSION... MOISTURE AS INDICATED ON SFC OBS SHOWING DEW PTS IN THE 60S AND SATELLITE TPW PRECIPITABLE WATER ESTIMATES NEAR 1.3 INCHES OR HIGHER ACROSS SWRN NEB WOULD SUGGEST A REASONABLE CHANCE OF TSTMS GIVEN THE WEAK DISTURBANCE MOVING THROUGH NRN COLO THIS AFTN. HOWEVER THE HRRR AND THE RAP MODELS ARE VERY QUIET GENERATING LIMITED CONVECTIVE ACTIVITY ACROSS THE HIGH PLAINS. THIS COULD BE THE RESULT OF WEAK UPSLOPE ADVECTION...A MID LEVEL SUBSIDENCE/CAP AND WEAK STEERING CURRENTS. MEANWHILE THE KLNX VWP INDICATES A VERY DEEP BUT WEAK EAST WINDS EXTENDING ALL THE WAY TO 12 KFT ASL. THE FCST THIS EVENING CALLS FOR ISOLATED STORMS GENERALLY ALONG AND WEST OF HIGHWAY 61. WE WILL CONTINUE TO CLOSELY MONITOR THE CONVECTION DEVELOPING IN COLO AND OBVIOUS DEEP MOISTURE PLUME ACROSS SWRN NEB. UPSLOPE FLOW MAY INCREASE LATE THIS AFTN AND EARLY THIS EVENING ENHANCING CONVERGENCE. THE MODERATE CU FORMING SOUTH OF THE WEATHER OFFICE AND CIGS NEAR 5 KFT AT HOLYOKE SUGGEST ATLEAST SOME POTENTIAL FOR ORGANIZED STORM DEVELOPMENT IF THE DISTURBANCE ACROSS COLO CAN REACH SWRN NEB BY EARLY EVENING. ON TUESDAY...LOW PRESSURE WILL BEGIN TRACKING THROUGH THE NRN PLAINS WHILE HIGH PRESSURE CONTINUES ACROSS ERN NEB. THIS SHOULD PRODUCE COOLER TEMPS SOUTH AND EAST IN THE SOUTH-SOUTHEAST WIND AREA AND VERY WARM TEMPS ACROSS THE NW ZONES WHERE DOWN SLOPING SOUTHWEST WINDS MAY DEVELOP. THE MOISTURE PLUME BECOMES DIFFUSE AND LESS FOCUSED AS IT IS DRAWN NORTH IN ALL MODELS EXCEPT THE GFS WHICH EXPLODES WEDNESDAY EVENING OVER SRN SD/NCNTL NEB AS A COLD FRONT APPROACHES THE FCST AREA. THE FATE OF THIS MOISTURE PLUME THE POTENTIAL FOR DESPERATELY NEEDED RAINFALL MIGHT BEST BE HANDLED INSIDE 12 HRS. THE OTHER MODELS ARE NOT GENERATING MUCH QPF...POSSIBLY THE RESULT OF WARM MIDLEVEL LAPSE RATES. A WEAK AREA OF COOLER HIGH PRESSURE WILL BUILD BEHIND THE FRONT THURSDAY AND TEMPS SHOULD SETTLE BACK IN TO THE 90S AFTER HIGHS AROUND 100 WEDNESDAY. ALL MODELS ARE IN GOOD AGREEMENT THAT A DEEP DISTURBANCE WILL MOVE THROUGH NRN HIGH PLAINS FRIDAY. THIS SYSTEM SHOULD PRODUCE STRONG SOUTHWEST WINDS WITH TEMPERATURES RISING TO OR ABOVE 100F IN MANY AREAS. A POWERFUL COLD FRONT WILL SWEEP THROUGH FRIDAY NIGHT AND COOL TEMPS BACK INTO THE 80S FOR SATURDAY. THE ECM HOLDS COOL HIGH PRESSURE INPLACE SUNDAY WHILE THE GFS IS OFF TO THE RACES DEEPENING LOW PRESSURE ACROSS THE NRN HIGH PLAINS. THE ECM IS PREFERRED FOR HIGHS IN THE LOWER 90S. BOTH MODELS ARE SHOWING A STRONG THERMAL RIDGE ACROSS THE HIGH PLAINS MONDAY. THIS SHOULD EASILY PRODUCE HIGHS IN THE UPPER 90S. THE UPPER LEVEL RIDGE AND ASSOCIATED SFC HEAT LOW SHOULD REMAIN ACROSS THE SRN HIGH PLAINS AND MID SOUTH DURING THE NEXT 7 DAYS. THE ECM IS TRYING TO AMPLIFY THE RIDGE INTO THE CENTRAL PLAINS BY NEXT MONDAY. RAIN CHANCES ARE GENERALLY CONFINED TO THE NORTH AND EAST LATE FRIDAY WITH THE APPROACHING COLD FRONT. A WEAK DISTURBANCE CROSSING ERN WY AND THE BLACK HILLS THURSDAY MAY BE THE CATALYST FOR ISOLATED STORMS LATE IN THE DAY OR AT NIGHT ACROSS MUCH OF THE FCST AREA. THE REST OF THE FCST...SATURDAY THROUGH MONDAY...IS DRY. BE AWARE THAT THE ONLY REAL HOPE FOR RAINFALL DURING THE NEXT 4 DAYS LIES IN THE FATE OF THE MOISTURE PLUME ACROSS SRN NEB THIS AFTERNOON. THERE REMAINS A VAST AREA OF VERY DRY AIR AT THE SURFACE AND LOWER LEVELS OF THE ATM. IN FACT THE WATER VAPOR PAIRED WITH THE TPW PRODUCT SHOW A TREMENDOUS SURGE OF DRY AIR FEEDING IN OFF THE PACIFIC THROUGH NEVADA...ID AND MT. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/EXTENDED...WFO LBF AVIATION...SPRINGER
AREA FORECAST DISCUSSION UPDATE
NWS LAS VEGAS NV
827 PM PDT WED AUG 1 2012 .SYNOPSIS...A DISTURBANCE IN THE ATMOSPHERE COMBINED WITH ABUNDANT MOISTURE AND INSTABILITY WILL RESULT IN SHOWERS AND THUNDERSTORMS AROUND AT TIMES THROUGH THIS WEEKEND. ALTHOUGH HEAVY RAIN WILL BE THE PRIMARY THREAT WITH HEAVIER STORMS...GUSTY WINDS AND HAIL MAY ALSO OCCUR. BY EARLY NEXT WEEK DRIER AIR LOOKS TO SLOWLY SPREAD EAST ACROSS THE AREA WHICH SHOULD DECREASE THE CHANCES FOR THUNDERSTORMS AND ALSO RESULT IN A WARMING TREND. && .UPDATE... ALTHOUGH WIDESPREAD CONVECTION ACROSS THE FORECAST AREA HAS DIMINISHED EARLY THIS EVENING...A LINE OF THUNDERSTORMS CURRENTLY JUST CROSSING THE NORTHERN CLARK COUNTY LINE HAS HELD TOGETHER SINCE INITIATING AT APPROXIMATELY 400 PM EARLIER TODAY AND IS EXPECTED TO CONTINUE TO HOLD TOGETHER AS THEY CONTINUE TO MOVE INTO UNSTABLE AIR. LATEST ANALYSIS SHOWS PLENTY OF INSTABILITY WITH LIS BETWEEN -3 AND -5...AND CAPE VALUES BETWEEN 1000 TO 2000 J/KG ACROSS SOUTHERN NEVADA...EASTERN SAN BERNARDINO...AND WESTERN MOHAVE COUNTIES. THESE THUNDERSTORMS ARE EXPECTED TO START TO MOVE OVER THE NORTHERN PART OF THE LAS VEGAS VALLEY BY 1000 PM...AND BE LARGELY THROUGH THE VALLEY BY 1130 PM BASED ON LATEST STORM MOTION. LIGHT SHOWERS WILL LIKELY LINGER BEHIND THE STORMS PAST MIDNIGHT. THE PRIMARY THREAT WILL BE FLASH FLOODING...AS THESE STORMS WILL BE EFFICIENT RAIN PRODUCERS...BUT SMALL HAIL AND STRONG NORTHWESTERLY IN EXCESS OF 45 MPH WILL ALSO BE POSSIBLE. RADAR ALSO INDICATES A WEAK BOUNDARY DRAPED ROUGHLY FROM THE SHEEP RANGE AND SOUTHWEST TO DUMONT DUNES...AND WILL NEED TO KEEP AN EYE ON THIS ALSO AS WE COULD SEE CONVECTION FOCUS ALONG THIS LINE AS THE STORMS MOVES SOUTHWEST. GRIDS HAVE BEEN UPDATED TO REFLECT THE HIGHER LIKELIHOOD OF PRECIPITATION OVERNIGHT...AND THE FLASH FLOOD WATCH HAS BEEN UPDATED. -KENNEDY- && .AVIATION...FOR MCCARRAN...A LINE OF THUNDERSTORMS CURRENTLY JUST CROSSING THE NORTHERN CLARK COUNTY IS EXPECTED TO CONTINUE TO HOLD TOGETHER AS THEY MOVE SOUTH TOWARDS THE LAS VEGAS VALLEY. BASED ON LATEST STORM MOTION...THESE STORMS LOOK MOST LIKELY TO BE OVER KLAS BY 0530Z. THE INITIAL IMPACT WILL BE A WIND SHIFT TO THE NORTHEAST...WITH GUSTS UP TO 40 MPH AS THE STORM APPROACHES KLAS. BRIEF HEAVY RAIN...FREQUENT LIGHTNING...AND CIGS DROPPING AS LOW AS 5KFT CAN BE EXPECTED AS THE STORMS PASS OVER. THE THREAT OF THUNDERSTORMS WILL BE GONE BY 0630Z...BUT LIGHT SHOWERS WILL LIKELY PERSIST FOR SEVERAL HOURS AFTER OVER OR IN THE VICINITY OF KLAS. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...ALTHOUGH WIDESPREAD CONVECTION ACROSS THE FORECAST AREA HAS DIMINISHED EARLY THIS EVENING...A CHANCES FOR SHRA/TSRA WILL CONTINUE ACROSS WESTERN MOHAVE...LINCOLN...CLARK...AND EASTERN SAN BERNARDINO COUNTIES. GUSTY AND ERRATIC WINDS AND REDUCED CIGS/VSBY NEAR ANY SHRA/TSRA. OTHERWISE WINDS FAVORING DIURNAL TRENDS WITH BKN CIGS AOA 10K-14K FEET. NO CONVECTION IS EXPECTED AT KBIH. -KENNEDY- && .PREV DISCUSSION... 331 PM PDT WED AUG 1 2012 .SHORT TERM...SO FAR THINGS HAVE NOT BEEN AS ACTIVE THIS AFTERNOON AS THEY WERE AT THIS POINT YESTERDAY DESPITE AN EXTREMELY MOIST ATMOSPHERE...PLENTY OF INSTABILITY AND MUCH MORE SUNSHINE. WATER VAPOR IMAGERY SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW WAS OVER SOUTHERN CLARK COUNTY AND MOVING SLOWLY NORTHEASTWARD. RADAR SHOWS AT THE PRESENT MOST OF THE ACTIVITY WAS ABOUT 100 MILES AWAY FROM THE CENTER OF THE LOW. THE ATMOSPHERE REMAINS EXCEPTIONALLY MOIST WITH THE 12Z SOUNDING THIS MORNING FROM OUR OFFICE HAVING A PWAT OF 1.82 INCHES. THIS TIED FOR THE SECOND HIGHEST PWAT EVER RECORDED IN THE SOUNDING CLIMATOLOGY FOR SOUTHERN NEVADA WITH A VALUE BACK IN AUGUST OF 1984 (THE HIGHEST EVER WAS 1.86 INCHES IN JULY 1966). WITH SO MUCH MOISTURE PRESENT ANY SHOWER OR THUNDERSTORM THAT GETS GOING WILL HAVE THE POTENTIAL TO PRODUCE EXTREMELY HEAVY RAIN IN A SHORT PERIOD OF TIME. THUS THE FLASH FLOOD WATCH OUT WILL REMAIN IN EFFECT. THE MAIN CHALLENGE FOR THIS EVENING AND THE REST OF TONIGHT WILL BE JUST HOW ACTIVE THINGS WILL GET. WITH THE MID/UPPER LEVEL LOW PROGGED TO BE AROUND THROUGH TONIGHT IT WILL BE HARD TO COMPLETELY SHUT DOWN ALL CONVECTION EXCEPT IN ANY AREAS WHERE THE AIR MASS GETS WORKED OVER ENOUGH THAT IT BECOMES MUCH MORE STABLE. IF YOU BELIEVE THE WRF...GFS AND ECMWF CONVECTION SHOULD WIND DOWN AROUND 03Z OR SO THIS EVENING. ON THE OTHER HAND...THE LOCAL ARW AND NMM MODELS AS WELL AS THE HRRR MODEL SHOW THE REVERSE WITH THINGS BECOMING MUCH MORE ACTIVE LATER THIS EVENING. 700 MB STEERING FLOW IS FROM THE NORTHEAST AND RADAR PRESENTLY SHOWS SHOWERS AND THUNDERSTORMS IN AN ARCH FROM AROUND ELY TO KANAB. TYPICALLY THIS PATTERN WOULD FAVOR THIS CONVECTION EVENTUALLY WORKING IN DURING THE LATE EVENING INTO CLARK COUNTY. IN THE PAST STORMS IN LAS VEGAS ORIGINATING FROM A NORTHEAST FLOW HAVE USUALLY BEEN RATHER POTENT. THUS...BASED ON A BLEND OF MODELS WE HAVE KEPT POPS IN THROUGH THE NIGHT FOR MUCH OF LINCOLN...CLARK...MOHAVE....EASTERN SAN BERNARDINO AND SOUTHERN NYE COUNTIES. ALTHOUGH FLASH FLOODING REMAINS A THREAT...WE CANNOT RULE OUT GUSTY WINDS OR HAIL WITH SOME STORMS ESPECIALLY IF THINGS DRY OUT A LITTLE. VERY LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED FOR THURSDAY AND FRIDAY. THE MID/UPPER LEVEL LOW IS FORECAST TO GET TRAPPED NEAR THE TRIPLE POINT OF CALIFORNIA...NEVADA AND ARIZONA AND EVENTUALLY WEAKEN TO A MORE ILL-DEFINED VORTICITY FEATURE. MEANWHILE HIGH PRESSURE IN THE MID AND UPPER LEVELS IS FORECAST TO BECOME CENTERED OVER CENTRAL NEVADA. THIS HIGH WILL KEEP AN EASTERLY MID-LEVEL FLOW OVER OUR AREA WHICH BY FRIDAY WILL HELP TO PUSH THE VORTICITY FEATURE TO THE SOUTHWEST AND BY FRIDAY NIGHT PUSH IT OFFSHORE OF SOCAL. OVER THE NEXT 2 DAYS THE FARTHER NORTHWEST ONE GOES IN THE CWFA THE LESS OF CHANCE FOR CONVECTION AS THE HIGH ALOFT WILL KEEP THE ATMOSPHERE MUCH MORE STABLE. FURTHER SOUTH THE COMBINATION OF THE VORTICITY FEATURE...INSTABILITY AND SUFFICIENT MOISTURE WILL KEEP THE POTENTIAL FOR THUNDERSTORMS AROUND. WHILE PWATS ARE FORECAST TO REMAIN OVER AN INCH OVER THE MOJAVE DESERT WHICH WILL SUPPORT HEAVY RAIN PRODUCING STORMS...WE WILL NOT ISSUE ANY FLASH FLOOD WATCHES FOR THURSDAY OR FRIDAY AT THIS TIME DUE TO UNCERTAINTIES IN JUST HOW ACTIVE IT WILL GET. TEMPS SHOULD BE A FEW DEGREES ABOVE NORMAL BUT MUCH WARMER THAN WHAT WE HAVE SEEN THE PAST FEW DAYS OVER THE MOJAVE DESERT. WELL ABOVE NORMAL TEMPS WILL CONTINUE OVER INYO AND ESMERALDA COUNTY. .LONG TERM...THE OLD VORTICITY FEATURE OFF OF SOCAL GETS CAUGHT UP IN A BROAD MID/UPPER LEVEL TROUGH OFF THE WEST COAST ON SATURDAY. IT APPEARS ENOUGH MOISTURE AND INSTABILITY REMAIN AROUND ON SATURDAY THAT THE POTENTIAL FOR THUNDERSTORMS WILL CONTINUE ESPECIALLY ACROSS THE NORTHERN HALF OF THE CWFA WHERE THE BEST INSTABILITY LOOKS TO SET UP. BY SATURDAY NIGHT INTO SUNDAY DRIER AND MORE STABLE AIR IS SHOWN TO WORK IN FROM THE SOUTH AS THE OFFSHORE TROUGH EDGES CLOSER TO THE COAST AND MOST OF THE EMBEDDED ENERGY WITHIN THE TROUGH STARTS TO LIFT ON NORTH. THUS SUNDAY MAY NOT BE QUITE AS ACTIVE FOR CONVECTION AND POPS SHOW A SLIGHT TREND DOWN THEN. BY MONDAY INTO NEXT WEDNESDAY THE TROUGH OFFSHORE STILL EXISTS AND RIDGING ALOFT SITS OVER THE FOUR CORNERS. THIS WOULD FAVOR A SOUTHWEST FLOW ALOFT ACROSS OUR AREA WHICH WOULD SPREAD DRIER AND STABLE AIR FURTHER EAST WITH TIME. I DID LOWER POPS AND DEWPOINTS IN THE WESTERN HALF OF THE AREA TO ACCOUNT FOR THIS HOWEVER MOIST AND UNSTABLE AIR IS SHOWN TO LINGER OVER MOHAVE COUNTY AND THIS PART OF THE AREA MAY NEVER REALLY DRY OUT. TEMPS SHOULD RISE BACK CLOSER TO NORMAL IN MOST AREAS AND MAY EVEN BE A FEW DEGREES ABOVE NORMAL ON MONDAY AND TUESDAY AS THINGS REALLY DRY OUT. I LEANED CLOSELY TO THE ECMWF MOS AND BIAS CORRECTED NUMBERS FOR HIGHS. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...FLASH FLOOD WATCH UNTIL 11 PM PDT THIS EVENING FOR NVZ016>022. AZ...FLASH FLOOD WATCH UNTIL 11 PM MST THIS EVENING FOR AZZ001>003- 036. CA...FLASH FLOOD WATCH UNTIL 11 PM PDT THIS EVENING FOR CAZ524>527. && $$ STACHELSKI HTTP://WEATHER.GOV/LASVEGAS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
851 PM CDT WED AUG 1 2012 .DISCUSSION... EVENING UPDATE MAINLY FOCUSED ON HIGHLIGHTING TSTM ACTIVITY ALONG CANADIAN BORDER AND REMOVING POPS ELSEWHERE. VORT MAX JUST SOUTH OF WINNIPEG HELPING MOVE A LINE OF TSTMS ACROSS SOUTHEAST MB AND INTO WRN ONTARIO. SOUTHERN STORMS NOW TRICKLING INTO NORTHERN COUNTIES...THUS WILL INCREASE TO SCATTERED STORMS FOR FAR NORTH AND REMOVE POPS ELSEWHERE. WILL ADJUST TEMPS AFTER VIEWING 9 PM OBS AND FURTHER ANALYZING NAM HOURLIES. && .AVIATION... VFR CONDS EXPECTED OVER NEXT 24 HOURS. TSTM ACTIVITY SHOULD REMAIN NORTH OF TVF TONIGHT. WINDS WILL BECOME LIGHT AND VARIABLE AND SHOULD REMAIN LIGHT THROUGH THE DAY THURSDAY. && .PREV DISCUSSION... /ISSUED 318 PM CDT WED AUG 1 2012/ SHORT TERM...TONIGHT THROUGH SATURDAY PRIMARY FORECAST CHALLENGE IS SHORT-TERM PRECIPITATION CHANCES... FOLLOWED BY FRIDAY/S SYSTEM. GFS/NAM/ECMWF/GEM ARE IN REASONABLE AGREEMENT...BUT HAVE HANDLED TODAY/S SHOWERS AND STORMS POORLY. LATEST HRRR BEST REFLECTS CURRENT SITUATION AND WILL FOLLOW ITS SOLUTION FOR THE NEXT 6-12 HOURS. 20 UTC RADAR LOOP SHOWS TWO AREAS OF PRECIPITATION. THE FIRST IS A LINE OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS FROM GLENDIVE MT TO NEAR DEVILS LAKE...MOVING EAST AROUND 35 KTS. THE SECOND IS A LINE OF SHOWERS AND THUNDERSTORMS FROM WALL SD TO ORTONVILLE MN...ALSO MOVING TO THE EAST AROUND 35 KTS. BOTH BANDS ARE ASSOCIATED WITH AN UPPER LEVEL SHORT-WAVE CROSSING INTO WESTERN ND...BUT WEAK INSTABILITY ACROSS MUCH OF ND IS LIMITING THUNDERSTORM ACTIVITY. MAJORITY OF THUNDERSTORMS SHOULD REMAIN SOUTH OF THE ND/SD STATE LINE ALONG 2000 TO 3000 J/KG MLCAPE INSTABILITY AXIS. LATEST HRRR BRINGS SHOWERS AND ISOLATED THUNDERSTORMS ACROSS CENTRAL ND MAINLY INTO THE CENTRAL/NORTHERN VALLEY AND THEN PORTIONS OF NORTHWEST MN LATE THIS AFTERNOON AND EVENING. EXPANDED 20 POPS INTO THESE AREAS THROUGH 03 UTC. WITH NO OTHER MODEL ACCURATELY REFLECTING THIS SCENARIO...UNCERTAIN HOW LONG SHOWERS WILL HOLD TOGETHER AND WILL KEEP FORECAST DRY ACROSS THE NORTH AFTER 03 UTC. DID ADD AN AREA OF 20 POPS ACROSS THE FAR SOUTH AS WELL THROUGH 06 UTC TO CATCH ANY STRAY ACTIVITY FROM SD CROSSING THE BORDER THIS EVENING. NO SEVERE WEATHER IS EXPECTED AT THIS TIME. SURFACE HIGH PRESSURE BUILDS ACROSS THE CWA BY 12 UTC THURSDAY... SO SHOULD SEE DECREASING CLOUDS AND LIGHT WIND ALLOWING MORNING LOWS TO DROP INTO THE UPPER 50S TO LOWER 60S. THE REST OF THE DAY WILL BE DRY WITH A MIX OF SUN AND CLOUDS AND TEMPERATURES SIMILAR TO TODAY. ATTENTION THEN TURNS TO THURSDAY NIGHT THROUGH SATURDAY AS A STRONG CANADIAN CLOSED LOW MOVES ACROSS THE NORTHERN PLAINS. PRIMARY CHANGE TO PREVIOUS FORECAST WAS TO SLOW EASTWARD PROGRESSION OF POPS. GFS/ECMWF IN GOOD AGREEMENT...SUGGESTING BEST FORCING WILL BE ALONG MID-LEVEL TROUGH WITH ADDITIONAL SUPPORT FROM A 50 TO 80 KT 300 HPA JET ROUNDING THE BASE OF THE UPPER LOW. SPREAD 60 TO 70 POPS FROM WEST TO EAST THURSDAY NIGHT THROUGH EARLY SATURDAY MORNING WITH THE BEST CHANCE FOR ACCUMULATING RAINFALL ALONG THE VALLEY FRIDAY AFTERNOON. STILL TO EARLY TO PINPOINT MOST FAVORED AREA FOR SEVERE CONVECTION...BUT LATEST GFS/ECMWF DO DEVELOP SOME KIND OF MCS ACROSS SOUTHEAST ND FRIDAY AFTERNOON. SPC DAY 3 CONVECTIVE OUTLOOK PAINTS A SLIGHT RISK ACROSS THE ENTIRE CWA EXCEPT THE FAR WESTERN DEVILS LAKE BASIN. SOMETHING TO WATCH CLOSELY OVER THE NEXT SEVERAL MODEL RUNS. COLD FRONT WILL MOVE WELL EAST OF THE AREA FOR SATURDAY...USHERING IN A CHANGE OF AIR MASS. HIGHS SATURDAY ONLY EXPECTED TO REACH THE UPPER 60S TO LOWER 70S WITH PERIODS OF SCATTERED WRAP AROUND RAIN SHOWERS. WINDS WILL ALSO BE BREEZY FROM THE NORTHWEST WITH OCCASIONAL GUSTS TO 30 MPH. LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY LONG RANGE MODELS AGREEABLE THROUGH MONDAY...THEN DIVERGE. NORTHWEST FLOW ALOFT APPEARS LIKELY THROUGH THE PERIOD AS UPPER RIDGE TO THE WEST GRADUALLY PROPAGATES TO THE EAST. MODELS INDICATE A CANADIAN UPPER LOW SENDING A COLD FRONT THROUGH THE REGION ON MONDAY...BUT DRY AIRMASS SHOULD LIMIT PRECIP. MONDAY HAS THE POTENTIAL TO BE THE WARMEST DAY...DEPENDING ON THE FROPA TIMING. THE ECMWF IS WEAKER WITH THE UPPER RIDGE AND DOES ALLOW FOR SOME WAVES TO ROUND THIS FEATURE BY LATER IN THE PERIOD. WILL CONTINUE WITH DRY FORECAST WITH SFC RIDGING AND DRY AIRMASS EXPECTED. AVIATION... VFR CIGS THROUGH THE PERIOD. ISOLATED SHOWERS POSSIBLE INTO THE EVENING...BUT WILL BE VERY LIGHT. WINDS WILL BECOME LIGHT THIS EVENING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
328 PM CDT TUE JUL 31 2012 .SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT... CRITICAL FIRE WEATHER CONDITIONS IN SOUTHWESTERN NORTH DAKOTA WITH A RED FLAG WARNING IN EFFECT THROUGH EARLY EVENING. SEE FIRE WEATHER SECTION BELOW. THE NEXT AREA OF CONCERN IS ANTICIPATED THUNDERSTORM DEVELOPMENT THIS AFTERNOON/EVENING. CURRENTLY...A SURFACE FRONT/TROUGH EXTENDED FROM A LOW AT THE SOUTHERN SASKATCHEWAN/MANITOBA BORDER TO BETWEEN WILLISTON/MINOT TO JUST EAST OF DICKINSON...TO NEAR HETTINGER. SURFACE TEMPERATURES WERE MAINLY IN THE UPPER 90S SOUTHWEST TO UPPER 80S IN THE JAMESTOWN AREA. THE MID-LEVEL ATMOSPHERIC CAP WAS STRONG AND INHIBITING ANY THUNDERSTORM DEVELOPMENT. THE BEST CHANCE FOR THUNDERSTORM DEVELOPMENT IS ALONG THE SURFACE FRONT/TROUGH. LATEST MODELS WERE IN DISAGREEMENT ON SURFACE WIND PATTERN...TROUGH PLACEMENT...AND UPPER LEVEL IMPULSE TRACK/PLACEMENT - AND ULTIMATELY DISAGREED ON THUNDERSTORM DEVELOPMENT. LATEST THINKING IS THAT ANY UPPER LEVEL IMPULSE FOR THIS AFTERNOON IS NOW IN NORTHERN MINNESOTA AND WILL LIKELY NOT AFFECT NORTH DAKOTA. THINKING THAT THE BEST MODEL TO FOLLOW IS THE LATEST 18Z HRRR WHICH DEVELOPS THUNDERSTORMS ALONG THE SURFACE TROUGH THIS EVENING BEFORE/NEAR SUNSET. THIS SCENARIO APPEARS TO BE THE MOST PLAUSIBLE AS THERE DOES NOT APPEAR TO BE ANY UPPER LEVEL KICKER TO DISTURB THE MID LEVEL THERMAL CAP. WITH THIS IN MIND...HAVE KEPT THE BEST CHANCES OF EVENING THUNDERSTORMS ALONG AND EAST OF A LINE FROM BOTTINEAU TO BISMARCK/MANDAN TO WESTERN GRANT/SIOUX COUNTIES. AFTER MIDNIGHT CHANCES ARE MAINLY CONFINED TO THE JAMES RIVER BASIN. A SLIGHTLY COOLER DAY ON WEDNESDAY WITH MAINLY NORTH/NORTHWEST WINDS WITH HIGHS FROM THE MID 80S NORTH TO LOWER 90S SOUTH. KEPT A SLIGHT CHANCE OF THUNDERSTORMS...MAINLY ACROSS THE NORTH...WITH AN UPPER LEVEL IMPULSE MOVING EAST ALONG THE CANADIAN BORDER. ANOTHER SLIGHT CHANCE OF THUNDERSTORMS WEDNESDAY NIGHT ACROSS THE FORECAST AREA...WITH A WESTERLY ZONAL FLOW ALOFT AND WEAK SHORTWAVES MOVING THROUGH THE REGION. .LONG TERM...WEDNESDAY THROUGH MONDAY... THE HIGHLIGHTS OF THE EXTENDED FORECAST ARE A BRIEF REPRIEVE FROM THE HEAT FRIDAY AND SATURDAY WITH AN INCREASING TEMPERATURE TREND THEREAFTER. THE 31/12 UTC GUIDANCE CONSENSUS HAS SLOWED SLIGHTLY WITH THE PROPAGATION OF THE GULF OF ALASKA ENERGY INTO THE NORTHERN PLAINS LATE THURSDAY INTO SATURDAY. LEADING IMPULSES AHEAD OF THE MAIN WAVE ARE EXPECTED TO PROVIDE THE LARGE SCALE SUPPORT FOR SCATTERED THUNDERSTORMS THURSDAY EVENING ACROSS MUCH OF THE AREA...WITH INSTABILITY AND SHEAR PROFILES ARE SUPPORTIVE OF THE POTENTIAL FOR A FEW STRONG TO SEVERE STORMS. HIGH TEMPERATURES ON FRIDAY ARE EXPECTED EXPECTED TO RANGE FROM THE LOWER 70S NORTHWEST TO THE MID 80S ACROSS THE JAMES RIVER VALLEY...WITH 70S AREA WIDE ON SATURDAY. IN REGARDS TO PRECIPITATION...THE BEST CHANCES ON FRIDAY ARE EXPECTED TO BE FOCUSED ACROSS THE SOUTH CENTRAL THROUGH THE JAMES RIVER VALLEY ALONG THE COLD FRONT...WITH COVERAGE DECREASING NORTHWEST WHERE PRECIPITATION WILL LIKELY BE MORE CELLULAR AND DIURNALLY DRIVEN WITH THE COLD CORE ALOFT. A DRY SLOT IS FORECAST TO OVERTAKE THE CWA FRIDAY NIGHT WITH WRAP AROUND PRECIPITATION ASSOCIATED WITH THE TROWAL AT THIS TIME EXPECTED TO REMAIN NORTH OF I-94 ON SATURDAY. THEREAFTER...MODEL UNCERTAINTY DOES INCREASE IN REGARDS TO THE RE-AMPLIFICATION OF THE SUB TROPICAL HIGH...HOWEVER...A WARMING TREND BACK TO AT LEAST NORMAL TEMPERATURES ARE EXPECTED BY EARLY NEXT WEEK. && .AVIATION... THE MAIN AVIATION HAZARD WILL BE THE POTENTIAL FOR THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AND INTO THE EVENING ALONG A WARM FRONT ACROSS CENTRAL NORTH DAKOTA. THE BEST TIMEFRAME FOR THUNDERSTORM DEVELOPMENT WILL BE 22-00 UTC...POSSIBLY IN THE VICINITY OF KBIS AND KMOT. HOWEVER...UNCERTAINTY DOES EXIST IN THE OVERALL COVERAGE OF STORMS. STORMS WILL PUSH EAST INTO THE EVENING TOWARDS THE KJMS TERMINAL. DUE TO UNCERTAINTY IN IMPACTS...WILL CODE AS VCTS FOR NOW. HOWEVER...A FEW OF THESE STORMS MAY BE STRONG TO SEVERE WITH LARGE HAIL...DAMAGING WINDS AND IFR CONDITIONS POSSIBLE. && .FIRE WEATHER... WINDS WERE SOUTHWESTERLY BEHIND THE SURFACE FRONT/TROUGH MENTIONED ABOVE IN THE SHORT TERM SECTION. WINDS HAD BECOME WEST AT 10 TO 20 MPH IN THE FAR WESTERN COUNTIES OF NORTH DAKOTA...INCLUDING BEACH...BOWMAN...AND HETTINGER. TEMPERATURES WERE IN THE 90S WITH RELATIVE HUMIDITY VALUES AROUND 25 PERCENT...AND TEMPERATURES ARE EXPECTED TO REMAIN IN THE 90S AND/OR CLIMB TO NEAR 100. DEWPOINTS WERE IN THE LOW TO MID 50S IN FAR WESTERN NORTH DAKOTA...BUT THINK THEY WILL DROP INTO THE 40S - AS SITES IN EASTERN MONTANA HAVE ALREADY. THUS EXPECT RELATIVE HUMIDITY EXPECTED TO DROP INTO THE TEENS LATE THIS AFTERNOON/EARLY EVENING. IT IS STILL POSSIBLE FOR THUNDERSTORM DEVELOPMENT...BUT THIS IS MORE LIKELY ALONG THE FRONT/TROUGH WHICH HAS BEGUN TO MOVE EAST OF THE RED FLAG AREA. ANY THUNDERSTORM THAT DEVELOPS WILL BE CAPABLE OF PRODUCING VERY STRONG AND ERRATIC WINDS IN EXCESS OF 60 MPH. THUS CRITICAL WEATHER BEHAVIOR REMAINS THE CONCERN FOR THE AFTERNOON AND EARLY EVENING HOURS FOR SOUTHWEST NORTH DAKOTA AND A RED FLAG WILL REMAIN IN EFFECT. && .BIS WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NDZ031-032-040- 043. && $$ SHORT TERM/FIRE WEATHER...JV LONG TERM/AVIATION...AYD
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
611 PM EDT TUE JUL 31 2012 .SYNOPSIS... UPPER LEVEL DISTURBANCE THIS AFTERNOON INTO TONIGHT. COLD FRONT MOVES THROUGH WEDNESDAY. HIGH PRESSURE WEDNESDAY NIGHT THROUGH FRIDAY. COLD FRONT ARRIVES LATER SUNDAY AND SUNDAY NIGHT. && .NEAR TERM /THROUGH WEDNESDAY/... 600 PM UPDATE...RAMPED UP POPS ACROSS EASTERN HIGH TERRAIN AND POINTS NORTHWEST OF THERE...ROUGHLY ALONG AND EAST OF INTERSTATE 79. MUCH LIKE LAST EVENING...PROPAGATION OF STORMS BEING DRIVEN BY OUTFLOW/COLD POOL INTERACTION WHICH HAS BEEN PUSHING NW OUT OF THE HIGHER TERRAIN TOWARDS THE I-79 CORRIDOR. ALSO LOWERED POPS A BIT ACROSS SE OHIO ZONES. EXPECT THE STRONGEST STORMS TO BEGIN WINDING DOWN OVER THE NEXT HOUR OR TWO. PREVIOUS DISCUSSION... NUMEROUS SHOWERS AND THUNDERSTORMS CURRENTLY DEPICTED BY RADAR OVER NORTHERN WV MOUNTAINS...WITH MORE ISOLATED ACTIVITY SOUTHWARD OVER THE MOUNTAINS. RAP SHOWS A VORT MAX ASSOCIATED WITH THIS ACTIVITY...WHICH PUSHES OFF TO THE EAST THROUGH THE AFTERNOON...WITH A SECOND VORT MAX MOVING IN FROM THE WEST. STILL WAITING FOR SIGNS OF THE SECOND WAVE TO SHOW...AS AN OUTFLOW BOUNDARY FROM EARLIER CONVECTION IN NORTHERN INDIANA ALSO MOVES IN. VISIBLE SAT SHOWED SOME BUILDING CUMULUS CLOUDS IN PERRY COUNTY...UP TOWARDS PBZ...ALONG THIS BOUNDARY BUT IT HAS BEEN FAIRLY SLOW TO CONTINUE DEVELOPMENT. EXPECTING MORE DEVELOPMENT AS THIS BOUNDARY PUSHES INTO CWA...WHERE THERE HAS BEEN A GOOD AMOUNT OF HEATING SO FAR TODAY. INTERESTINGLY...THE WRFNMM SHOWS AN OUTFLOW BOUNDARY COMING WEST OUT OF THE ACTIVITY NEAR EKN...MEETING THE BOUNDARY APPROACHING FROM THE NORTHEAST...DEVELOPING PRETTY ROBUST CONVECTION ALONG I-79. WILL HAVE TO WAIT AND SEE JUST HOW THIS GOES...BUT AT ANY RATE...EXPECT ISOLATED TO SCATTERED SHOWERS AND STORMS THIS AFTERNOON. ISOLATED SHOWERS AND STORMS MAY LINGER OVERNIGHT...WITH SCATTERED STORMS AGAIN WEDNESDAY AS ANOTHER UPPER LEVEL SHORTWAVE TROUGH PASSES THROUGH. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... MODELS SHOW A BRIEF LULL IN THE ACTIVE THUNDERSTORM PATTERN AS AN UPPER LEVEL DISTURBANCE IN NORTHWEST FLOW ALOFT EXITS TO THE SOUTHEAST AND ALLOWS WEAK HIGH PRESSURE TO BUILD IN FOR WEDNESDAY NIGHT AND THURSDAY. THIS WILL ALLOW DRIER AIR TO OVERSPREAD THE AREA...THOUGH TEMPERATURES THURSDAY WILL BE SIMILAR TO WEDNESDAY. HOWEVER...WITH THE DRIER AIR...WEDNESDAY NIGHT WILL BE SOMEWHAT COOLER THAN PREVIOUS NIGHTS. LOOK FOR TEMPERATURES TO REACH AROUND 90 DEGREES MANY LOW LAND LOCATIONS AGAIN THURSDAY...BUT LESS HUMIDITY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... HEIGHTS ONCE AGAIN BUILD IN FROM THE WEST BY FRIDAY WITH THE BERMUDA HIGH STRENGTHENING...ALLOWING THE HEAT AND HUMIDITY TO MOVE BACK IN FROM THE SOUTHWEST. CHANCES FOR STORMS INCREASE LATER FRIDAY AND SATURDAY ON MORE OF A DIURNAL BASIS WITH THE INCREASING INSTABILITY. THIS WILL ALSO BRING MORE HEAT BACK...WITH HIGH TEMPERATURES FRIDAY AND SATURDAY REACHING INTO THE 90S AGAIN. ANOTHER STRONGER NORTHWEST FLOW SYSTEM AND ATTENDING COLD FRONT DROP SOUTHEASTWARD TOWARD THE AREA SUNDAY AND SUNDAY NIGHT. THIS WILL INCREASE CHANCES FOR STORMS SUNDAY AND SUNDAY NIGHT AHEAD OF THE FRONT. MODELS ARE SOMEWHAT DIFFERENT IN TIMING OF THE SYSTEM...BUT SUING THE SLOWER EURO AND GFS MODELS IN THIS HIGH SUMMER PATTERN LOOKS REASONABLE. THIS WILL PUSH THE FRONT THROUGH MONDAY MORNING WITH SHOWERS DECREASING FROM NORTHWEST TO SOUTHEAST ON MONDAY...FOLLOWED BY SLIGHTLY COOLER TEMPS. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... CONVECTION CURRENTLY ONGOING ACROSS THE WV MOUNTAINS...ESPECIALLY THE NORTHERN MOUNTAINS NEAR KEKN. EXPECT DROPS INTO MVFR AND EVEN IFR IN THE HEAVIEST SHOWERS THROUGH THIS AFTERNOON...WHICH WILL NEED TO BE ADDRESSED BY TEMPOS IF STORMS APPROACH TAF SITES. EXPECT MORE ISOLATED TO SCATTERED CONVECTION ACROSS THE LOWLANDS...SO WILL KEEP VCTS IN THE TAFS. EXPECT VERY WEAK WINDS TONIGHT...AND WITH CLOUDS BECOMING SCATTERED...FOG SHOULD DEVELOP. HOWEVER WITH MORE CLOUDS AROUND...MAY NOT SEE AS DENSE OF FOG AS LAST NIGHT AT MANY LOCATIONS. INCLUDED MVFR VISIBILITIES AT KCRW...KHTS...KPKB...WITH DENSE LIFR FOG AT KEKN...AND IN OTHER PRONE VALLEY LOCATIONS. WILL AGAIN SEE SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY...ESPECIALLY FROM CRW-CKB AND WESTWARD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING OF THUNDERSTORMS COULD VARY THROUGH THE PERIOD. TIMING AND DENSITY OF FOG DISSIPATION COULD VARY TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H L L L PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 00Z THURSDAY... BRIEF IFR POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY AFTERNOON. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/MZ NEAR TERM...MZ/50 SHORT TERM...JMV LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
417 PM EDT TUE JUL 31 2012 .SYNOPSIS... A WEAK COLD FRONT MAY BRING A FEW THUNDERSTORMS THIS EVENING. HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS WEDNESDAY AND THURSDAY. SHORT WAVE ENERGY ABOVE AN UNSTABLE AIRMASS WILL PROVIDE A CHANCE OF THUNDERSTORMS ON FRIDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A TROUGH IN THE UPPER ATMOSPHERE IS EVIDENT ON WATER VAPOR IMAGERY AND ON MODELS. SURFACE MAP HAS A WEAK TROUGH OVER NORTHWEST OHIO WITH HIGHER DEW POINTS AND GREATER INSTABILITY BEHIND THE TROUGH. ISOLATED THUNDERSTORMS HAVE DEVELOPED ALONG AND BEHIND THE TROUGH AXIS...ESPECIALLY OVER WESTERN INDIANA AND EASTERN ILLINOIS WHERE A SEVERE THUNDERSTORM WATCH IS IN EFFECT. AS THE SURFACE TROUGH MOVES EAST THIS EVENING...INSTABILITY WILL INCREASE AND SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP. WITH WITH DELTA THETA E VALUES OF ~30K...STRONG DOWNDRAFT POTENTIAL EXISTS SO SOME THUNDERSTORMS MAY BE SEVERE...ESPECIALLY OVER SOUTHWEST COUNTIES WHERE SHEAR AND INSTABILITY WILL BE SLIGHTLY MORE FAVORABLE. THUNDERSTORMS SHOULD WIND DOWN OVERNIGHT WITH LOSS OF DAYTIME HEATING. UNDER MOSTLY CLEAR SKIES BY DAYBREAK...TEMPERATURES WILL FALL TO THE MID AND UPPER 60S. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... TROUGH AXIS WILL BE MOVING EAST OF THE AREA AND DRIER AND MORE STABLE AIR WILL BE MOVING IN WITH HIGH PRESSURE. THE AREA SHOULD BE FREE FROM PRECIPITATION SINCE CONVECTION ASSOCIATED WITH THE TROUGH WILL PROBABLY NOT FIRE UP UNTIL THE TROUGH EXITS IN THE AFTERNOON. CLEAR SKIES ARE EXPECTED WEDNESDAY NIGHT WITH HIGH PRESSURE CENTERED OVER NORTHERN OHIO. TEMPERATURES WILL BE CLOSE TO NORMAL AND A BIT COOLER WITH HIGHS IN THE MID AND UPPER 80S. && .LONG TERM /THURSDAY THROUGH TUESDAY/... HIGH PRESSURE ON THURSDAY WILL BE FOUND WITH ZONAL FLOW ALOFT. THERE WAS SOME EARLIER NOTES OF VORT MAXES AND/OR WEAK SHORTWAVES IN THIS FLOW WHICH MAY INSTIGATE SOME SHOWER ACTIVITY ON FRIDAY...BUT KEPT LOWERING CHANCES SIGNIFICANTLY FROM PREVIOUS FORECAST. RETURN FLOW AT THE SURFACE WILL ALLOW TEMPERATURES TO INCREASE AND MOISTURE TO STREAM IN FROM THE SOUTH FOR FRIDAY. LOW PRESSURE WELL TO THE NORTHWEST COULD PUSH ENOUGH MOISTURE AND INSTABILITY INTO THE OHIO VALLEY IN THE WARM SECTOR THAT SCATTERED POPUP SHOWERS ARE POSSIBLE ON SATURDAY TRIGGERED BY DAYTIME HEATING. THE COLD FRONT IS PROGGED TO CROSS THE OHIO VALLEY ON SUNDAY AND THIS IS THE DAY WHERE SHOWERS AND THUNDERSTORMS WILL BE AT THEIR PROBABILISTIC PEAK. BEING 5 DAYS OUT I WAS HESITANT TO GO WITH LIKELY WORDING AS THERE WILL BE TIMING ISSUES TO WORK OUT. AFTER THE FRONT CROSSES...ANY LINGERING SHOWERS SUNDAY NIGHT SHOULD END FROM NORTHWEST TO SOUTHEAST AND HIGH PRESSURE WILL HELP PUSH IN DRIER AND COOLER AIR IN ITS WAKE FOR EARLY NEXT WEEK. TEMPERATURES WILL MODERATE QUICKLY AS AN APPARENT LACK OF CLOUD COVER WILL PROBABLY ALLOW ABUNDANT SUNSHINE TO WARM THE REGION BACK UP. EVEN WITH THE WARMER TEMPERATURES EXPECTED TO RETURN...DRIER AIR SHOULD LET NIGHTTIME LOWS DROP NICELY. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... EXPECT VFR CONDITIONS TO CONTINUE TODAY. REMNANTS OF EARLY MORNING MCS HAS LEFT A CAP OVER ILN/S CWA...EVIDENT IN LATEST RAP DATA AND CU FREE VISIBLE IMAGERY. HAVE MOVED BACK MENTION OF THUNDER TIMING AND LIMITED THIS MENTION TO VCTS TO BETWEEN 21Z AND 02Z. FORCING IS RATHER WEAK SO UNCERTAINTY IN LOCATION AND TIMING CONTINUES TO BE LOW. CLOUD BASES WILL BE HIGH BASED AND VFR IN ANY STORMS THAT DUE OCCUR AT THE TAF SITES. AS SKIES CLEAR AND WINDS BECOME LIGHT OVERNIGHT...EXPECT VISIBILITY RESTRICTIONS TO DEVELOP IN MIST/FOG. .OUTLOOK...MVFR VISIBILITIES POSSIBLE WEDNESDAY NIGHT INTO EARLY THURSDAY. THUNDERSTORMS POSSIBLE FRIDAY INTO SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...CONIGLIO NEAR TERM...CONIGLIO SHORT TERM...CONIGLIO LONG TERM...FRANKS AVIATION...AR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
246 PM EDT TUE JUL 31 2012 .SYNOPSIS... UPPER LEVEL DISTURBANCE THIS AFTERNOON INTO TONIGHT. COLD FRONT MOVES THROUGH WEDNESDAY. HIGH PRESSURE WEDNESDAY NIGHT THROUGH FRIDAY. COLD FRONT ARRIVES LATER SUNDAY AND SUNDAY NIGHT. && .NEAR TERM /THROUGH WEDNESDAY/... NUMEROUS SHOWERS AND THUNDERSTORMS CURRENTLY DEPICTED BY RADAR OVER NORTHERN WV MOUNTAINS...WITH MORE ISOLATED ACTIVITY SOUTHWARD OVER THE MOUNTAINS. RAP SHOWS A VORT MAX ASSOCIATED WITH THIS ACTIVITY...WHICH PUSHES OFF TO THE EAST THROUGH THE AFTERNOON...WITH A SECOND VORT MAX MOVING IN FROM THE WEST. STILL WAITING FOR SIGNS OF THE SECOND WAVE TO SHOW...AS AN OUTFLOW BOUNDARY FROM EARLIER CONVECTION IN NORTHERN INDIANA ALSO MOVES IN. VISIBLE SAT SHOWED SOME BUILDING CUMULUS CLOUDS IN PERRY COUNTY...UP TOWARDS PBZ...ALONG THIS BOUNDARY BUT IT HAS BEEN FAIRLY SLOW TO CONTINUE DEVELOPMENT. EXPECTING MORE DEVELOPMENT AS THIS BOUNDARY PUSHES INTO CWA...WHERE THERE HAS BEEN A GOOD AMOUNT OF HEATING SO FAR TODAY. INTERESTINGLY...THE WRFNMM SHOWS AN OUTFLOW BOUNDARY COMING WEST OUT OF THE ACTIVITY NEAR EKN...MEETING THE BOUNDARY APPROACHING FROM THE NORTHEAST...DEVELOPING PRETTY ROBUST CONVECTION ALONG I-79. WILL HAVE TO WAIT AND SEE JUST HOW THIS GOES...BUT AT ANY RATE...EXPECT ISOLATED TO SCATTERED SHOWERS AND STORMS THIS AFTERNOON. ISOLATED SHOWERS AND STORMS MAY LINGER OVERNIGHT...WITH SCATTERED STORMS AGAIN WEDNESDAY AS ANOTHER UPPER LEVEL SHORTWAVE TROUGH PASSES THROUGH. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... MODELS SHOW A BRIEF LULL IN THE ACTIVE THUNDERSTORM PATTERN AS AN UPPER LEVEL DISTURBANCE IN NORTHWEST FLOW ALOFT EXITS TO THE SOUTHEAST AND ALLOWS WEAK HIGH PRESSURE TO BUILD IN FOR WEDNESDAY NIGHT AND THURSDAY. THIS WILL ALLOW DRIER AIR TO OVERSPREAD THE AREA...THOUGH TEMPERATURES THURSDAY WILL BE SIMILAR TO WEDNESDAY. HOWEVER...WITH THE DRIER AIR...WEDNESDAY NIGHT WILL BE SOMEWHAT COOLER THAN PREVIOUS NIGHTS. LOOK FOR TEMPERATURES TO REACH AROUND 90 DEGREES MANY LOW LAND LOCATIONS AGAIN THURSDAY...BUT LESS HUMIDITY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... HEIGHTS ONCE AGAIN BUILD IN FROM THE WEST BY FRIDAY WITH THE BERMUDA HIGH STRENGTHENING...ALLOWING THE HEAT AND HUMIDITY TO MOVE BACK IN FROM THE SOUTHWEST. CHANCES FOR STORMS INCREASE LATER FRIDAY AND SATURDAY ON MORE OF A DIURNAL BASIS WITH THE INCREASING INSTABILITY. THIS WILL ALSO BRING MORE HEAT BACK...WITH HIGH TEMPERATURES FRIDAY AND SATURDAY REACHING INTO THE 90S AGAIN. ANOTHER STRONGER NORTHWEST FLOW SYSTEM AND ATTENDING COLD FRONT DROP SOUTHEASTWARD TOWARD THE AREA SUNDAY AND SUNDAY NIGHT. THIS WILL INCREASE CHANCES FOR STORMS SUNDAY AND SUNDAY NIGHT AHEAD OF THE FRONT. MODELS ARE SOMEWHAT DIFFERENT IN TIMING OF THE SYSTEM...BUT SUING THE SLOWER EURO AND GFS MODELS IN THIS HIGH SUMMER PATTERN LOOKS REASONABLE. THIS WILL PUSH THE FRONT THROUGH MONDAY MORNING WITH SHOWERS DECREASING FROM NORTHWEST TO SOUTHEAST ON MONDAY...FOLLOWED BY SLIGHTLY COOLER TEMPS. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... CONVECTION CURRENTLY ONGOING ACROSS THE WV MOUNTAINS...ESPECIALLY THE NORTHERN MOUNTAINS NEAR KEKN. EXPECT DROPS INTO MVFR AND EVEN IFR IN THE HEAVIEST SHOWERS THROUGH THIS AFTERNOON...WHICH WILL NEED TO BE ADDRESSED BY TEMPOS IF STORMS APPROACH TAF SITES. EXPECT MORE ISOLATED TO SCATTERED CONVECTION ACROSS THE LOWLANDS...SO WILL KEEP VCTS IN THE TAFS. EXPECT VERY WEAK WINDS TONIGHT...AND WITH CLOUDS BECOMING SCATTERED...FOG SHOULD DEVELOP. HOWEVER WITH MORE CLOUDS AROUND...MAY NOT SEE AS DENSE OF FOG AS LAST NIGHT AT MANY LOCATIONS. INCLUDED MVFR VISIBILITIES AT KCRW...KHTS...KPKB...WITH DENSE LIFR FOG AT KEKN...AND IN OTHER PRONE VALLEY LOCATIONS. WILL AGAIN SEE SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY...ESPECIALLY FROM CRW-CKB AND WESTWARD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING OF THUNDERSTORMS COULD VARY THROUGH THE PERIOD. TIMING AND DENSITY OF FOG DISSIPATION COULD VARY TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H L PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z WEDNESDAY... BRIEF IFR POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY AFTERNOON. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/MZ NEAR TERM...MZ SHORT TERM...JMV LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
230 PM EDT TUE JUL 31 2012 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA TODAY AS A COLD FRONT APPROACHES AND MOVES THROUGH THE REGION. HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS WEDNESDAY AND THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY MORNING MCS WHICH DROPPED SE ACRS NRN IN AND INTO NW OHIO HAS WEAKENED...LEAVING AN OUTFLOW BOUNDARY WHICH IS DROPPING INTO SRN IN AND SRN OHIO. MID LEVEL S/W TO TRACK THRU THE EASTERN GREAT LAKES TODAY WITH A TAIL OF VORTICITY DROPPING THRU SRN OHIO EARLY THIS EVENING. ASSOCIATED SLOW MOVING COLD FRONT TO SLIP INTO OHIO OVERNIGHT. WITH SFC HEATING AND SOME ADVECTION OF LOW LEVEL MOISTURE FROM THE W WILL RESULT IN MODERATE INSTABILITY. THUNDERSTORM DEVELOPMENT WILL BE LKLY AHD THE OUTFLOW BOUNDARY...AS WELL AS IN ADVANCE OF THE COLD FRONT BY MID AFTERNOON ALONG THESE BOUNDARIES. A FEW STORMS COULD PRODUCE DAMAGING WINDS AND MARGINALLY SEVERE HAIL THIS AFTERNOON INTO EARLY EVENING ACRS SE INDIANA/SW OH AND NRN KY. WILL HIGHLIGHT THIS POTENTIAL IN THE HWO PRODUCT. HAVE CONTD PREV FCST THINKING GOING ON THE WARM SIDE OF TEMP GUIDANCE FOR HIGH TEMPERATURES TODAY. HEAT INDEX VALUES WILL BE IN THE MIDDLE TO UPPER 90S ACRS THE SW AND WILL CONTINUE TO HIGHLIGHT THESE VALUES IN THE HWO FOR TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... SHOWER AND THUNDERSTORM ACTIVITY WILL BEGIN TO TAPER OFF ACROSS THE FA THIS EVENING AND DRY CONDITIONS WILL RETURN TO THE FA BY AROUND MIDNIGHT TONIGHT. HIGH PRESSURE WILL WORK INTO THE FA FOR WEDNESDAY AND THURSDAY ALLOWING FOR DRY CONDITIONS ACROSS THE REGION. THE MODELS CONTINUE TO DISAGREE ON THE AMOUNT OF MOISTURE WORKING NORTH INTO THE AREA ON FRIDAY INTO FRIDAY NIGHT. DUE TO RUN TO RUN INCONSISTENCIES AND MODEL DIFFERENCES DECIDED TO GO WITH A BLEND FOR FRIDAY AND FRIDAY NIGHT. IN ADDITION...DUE TO UNCERTAINTIES IN THE PLACEMENT AND TIMING OF THE PRECIPITATION HAVE DECIDED TO LIMIT PRECIPITATION CHANCES TO THE CHANCE CATEGORY AT THIS TIME. WENT CLOSE TO GUIDANCE FOR TEMPERATURES DURING THE SHORT TERM TIME FRAME. && .LONG TERM /SATURDAY THROUGH MONDAY/... HAVE TAKEN A BLEND OF NCEP/HPC AND THE 00Z ECMWF/12Z GFS FOR THE EXTENDED FORECAST. UPR LVL FLOW WILL TRANSITION TO A MORE ZONAL PATTERN ON SATURDAY...AND WITH RETURN SFC FLOW/MOISTURE AND EMBEDDED DISTURBANCES RIPPLING WEST TO EAST ALOFT...HAVE KEPT CHANCES FOR SHOWERS/STORMS DURING THIS PERIOD. IT MUST BE NOTED THAT THE ECMWF CONTINUES TO SHOW A MORE DEEPER MOISTURE TRANSPORT INTO THE REGION ON SATURDAY WHILE THE GFS AND CMC SHOW A MORE DISJOINTED MOISTURE RETURN FLOW. THE RESULT IS HIGHER CHANCES FOR PCPN ON THE ECMWF AND MUCH LOWER CHANCES ON THE GFS AND CMC. THIS HAS YET TO BE RESOLVED AND HAVE THUS KEPT CHANCE POPS. A STRONGER S/WV AND COLD FRONT IS POISED TO AFFECT THE REGION SUNDAY AND SUNDAY NIGHT...OFFERING AN ENHANCED CHANCE OF SHOWERS AND STORMS. THE COLD FRONT IS PROGGED TO SLIDE SE OF THE AREA ON MONDAY...GRADUALLY BRINGING AN END TO THE PCPN AND ALLOWING DRIER AIR TO BUILD BACK INTO THE AREA ONCE AGAIN. TEMPERATURES ON A WHOLE SHOULD AVERAGE ABOVE NORMAL THROUGH THE PERIOD. HOW FAR ABOVE NORMAL WILL DEPEND ON CLOUD COVER AND PRECIPITATION COVERAGE. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... EXPECT VFR CONDITIONS TO CONTINUE TODAY. REMNANTS OF EARLY MORNING MCS HAS LEFT A CAP OVER ILN/S CWA...EVIDENT IN LATEST RAP DATA AND CU FREE VISIBLE IMAGERY. HAVE MOVED BACK MENTION OF THUNDER TIMING AND LIMITED THIS MENTION TO VCTS TO BETWEEN 21Z AND 02Z. FORCING IS RATHER WEAK SO UNCERTAINTY IN LOCATION AND TIMING CONTINUES TO BE LOW. CLOUD BASES WILL BE HIGH BASED AND VFR IN ANY STORMS THAT DUE OCCUR AT THE TAF SITES. AS SKIES CLEAR AND WINDS BECOME LIGHT OVERNIGHT...EXPECT VISIBILITY RESTRICTIONS TO DEVELOP IN MIST/FOG. .OUTLOOK...MVFR VISIBILITIES POSSIBLE WEDNESDAY NIGHT INTO EARLY THURSDAY. THUNDERSTORMS POSSIBLE FRIDAY INTO SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...NOVAK NEAR TERM...AR SHORT TERM...NOVAK LONG TERM...HICKMAN AVIATION...AR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
130 PM EDT TUE JUL 31 2012 .SYNOPSIS... UPPER LEVEL DISTURBANCE THIS AFTERNOON INTO TONIGHT. COLD FRONT MOVES THROUGH WEDNESDAY. HIGH PRESSURE WEDNESDAY NIGHT THROUGH FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY/... NUMEROUS SHOWERS AND THUNDERSTORMS CURRENTLY DEPICTED BY RADAR OVER NORTHERN WV MOUNTAINS...WITH MORE ISOLATED ACTIVITY SOUTHWARD OVER THE MOUNTAINS. RAP SHOWS A VORT MAX ASSOCIATED WITH THIS ACTIVITY...WHICH PUSHES OFF TO THE EAST THROUGH THE AFTERNOON...WITH A SECOND VORT MAX MOVING IN FROM THE WEST. STILL WAITING FOR SIGNS OF THE SECOND WAVE TO SHOW...AS AN OUTFLOW BOUNDARY FROM EARLIER CONVECTION IN NORTHERN INDIANA ALSO MOVES IN. VISIBLE SAT SHOWED SOME BUILDING CUMULUS CLOUDS IN PERRY COUNTY...UP TOWARDS PBZ...ALONG THIS BOUNDARY BUT IT HAS BEEN FAIRLY SLOW TO CONTINUE DEVELOPMENT. EXPECTING MORE DEVELOPMENT AS THIS BOUNDARY PUSHES INTO CWA...WHERE THERE HAS BEEN A GOOD AMOUNT OF HEATING SO FAR TODAY. INTERESTINGLY...THE WRFNMM SHOWS AN OUTFLOW BOUNDARY COMING WEST OUT OF THE ACTIVITY NEAR EKN...MEETING THE BOUNDARY APPROACHING FROM THE NORTHEAST...DEVELOPING PRETTY ROBUST CONVECTION ALONG I-79. WILL HAVE TO WAIT AND SEE JUST HOW THIS GOES...BUT AT ANY RATE...EXPECT ISOLATED TO SCATTERED SHOWERS AND STORMS THIS AFTERNOON. ISOLATED SHOWERS AND STORMS MAY LINGER OVERNIGHT...WITH SCATTERED STORMS AGAIN WEDNESDAY AS ANOTHER UPPER LEVEL SHORTWAVE TROUGH PASSES THROUGH. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AREA WILL CONT TO BE UNDER THE INFLUENCE OF UPR TROF WITH NW FLOW IN THE MID AND UPR LEVELS. LAGGING SFC FRONT TAKES ALL OF WED TO ATTEMPT TO CROSS CWA MORE LKLY WASHING OUT OVER UPR OH VALLEY LEAVING BEHIND AREA OF WEAK LLVL CONVERGENCE/TROF NEARBY. KEPT POPS LOW WITH THIS AS OVERALL MOISTURE DEPTH IS LACKING. HAVING SAID THAT STILL EXPECT A FEW SHRA/TSRA WITH THE BOUNDARY. SFC HIGH BUILDS IN FOR THU WITH ONLY SLIGHTLY LOWER HUMIDITY BUT REMAINING RATHER WARM. AN UPR LVL DISTURBANCE MAY DROP DOWN WITHIN UPR TROF FRIDAY WITH SOME STORMS TO ACCOMPANY IT. && .LONG TERM /SATURDAY THROUGH MONDAY/... HEIGHTS ONCE AGAIN BUILD IN FROM THE WEST FRIDAY WITH THE BERMUDA HIGH STRENGTHENING...ALLOWING THE HEAT AND HUMIDITY TO MOVE BACK IN FROM THE SOUTHWEST. CHANCES FOR STORMS INCREASE BY THE WEEKEND AS ANOTHER NORTHWEST FLOW SYSTEM AND ATTENDING COLD FRONT DROP SOUTHEASTWARD TOWARD THE AREA. TEMPS WILL ALSO WARM BACK INTO THE 90S AHEAD OF THE FRONT. && .AVIATION /17Z TUESDAY THROUGH SATURDAY/... CONVECTION CURRENTLY ONGOING ACROSS THE WV MOUNTAINS...ESPECIALLY THE NORTHERN MOUNTAINS NEAR KEKN. EXPECT DROPS INTO MVFR AND EVEN IFR IN THE HEAVIEST SHOWERS THROUGH THIS AFTERNOON...WHICH WILL NEED TO BE ADDRESSED BY TEMPOS IF STORMS APPROACH TAF SITES. EXPECT MORE ISOLATED TO SCATTERED CONVECTION ACROSS THE LOWLANDS...SO WILL KEEP VCTS IN THE TAFS. EXPECT VERY WEAK WINDS TONIGHT...AND WITH CLOUDS BECOMING SCATTERED...FOG SHOULD DEVELOP. HOWEVER WITH MORE CLOUDS AROUND...MAY NOT SEE AS DENSE OF FOG AS LAST NIGHT AT MANY LOCATIONS. INCLUDED MVFR VISIBILITIES AT KCRW...KHTS...KPKB...WITH DENSE LIFR FOG AT KEKN...AND IN OTHER PRONE VALLEY LOCATIONS. WILL AGAIN SEE SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY...ESPECIALLY FROM CRW-CKB AND WESTWARD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING OF THUNDERSTORMS COULD VARY THROUGH THE PERIOD. TIMING AND DENSITY OF FOG DISSIPATION COULD VARY TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z WEDNESDAY... BRIEF IFR POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY AFTERNOON. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/MZ NEAR TERM...MZ SHORT TERM...30 LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS PORTLAND OR
625 AM PDT TUE JUL 31 2012 .SYNOPSIS...THERE WILL BE LITTLE CHANGE IN WEATHER THE NEXT FEW DAYS WITH MARINE CLOUDS PUSHING INLAND OVERNIGHT AND CLEARING IN THE AFTERNOONS. HIGH PRESSURE AND WARMER TEMPERATURES ARE EXPECTED AT THE END OF THE WEEK. && .UPDATE...UPDATED AVIATION DISCUSSION. .SHORT TERM...CLOUDS HAVE A LITTLE SLOWER TO DEVELOP AND PUSH INLAND THIS MORNING...ESP IN THE S...BUT STILL A DECENT ONSHORE FLOW COUPLED WITH THE LEFT OVER MARINE AIR MASS SHOULD FAVOR CLOUDS MOSTLY FILLING IN THE INLAND VALLEYS THIS MORNING. SHORTWAVE SEEN IN WATER VAPOR PICTURES NEAR 130 W WILL HAVE JUST SHALLOW MOISTURE TO WORK WITH...SO A MENTION OF DRIZZLE NEAR THE COAST THIS MORNING LOOKS ADEQUATE. A NEAR PERSISTENCE FORECAST APPEARS TO APPLY OTHERWISE TODAY AND WED AS WSW FLOW CONTINUES ALOFT WITH A LOW LEVEL ONSHORE FLOW. THE SHORTWAVE TODAY POTENTIALLY HELPS TO REINFORCE THE MARINE LAYER AGAIN TONIGHT. A TROUGH DIGGING DOWN THROUGH BC INTO SOUTHERN ALBERTA WED NIGHT AND THU MARKS A LITTLE DIFFERENT TWIST TO THE FORECAST PATTERN. BOTH GFS AND ECMWF PROMISE A LITTLE DEEPER LOW LEVEL MOISTURE WITH THE TAIL END OF A COLD FRONT LATE WED NIGHT AND EARLY THU. LITTLE IN THE WAY OF LIFT AVAILABLE WITH THIS MOISTURE HOWEVER...BUT WILL ADD A MENTION OF SOME LIGHT RAIN OR DRIZZLE TO THE NW PART OF THE FORECAST AREA ALONG WITH MORE CLOUDS FOR THE N PART OF THE AREA THU. .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. THE UPPER LEVEL TROUGH WILL MOVE INTO NORTHEAST BC LATE THU INTO FRI WHILE SURFACE HIGH PRESSURE SETS UP OVER EASTERN OREGON. THIS SCENARIO WILL ALLOW BRIEF OFFSHORE FLOW TO DEVELOP FRI AND FRI NIGHT. PERSISTENT ONSHORE FLOW RETURNS FOR THE WEEKEND AS AN UPPER LEVEL RIDGE MOVES OVER THE AREA...MAINTAINING THE NIGHT/MORNING MARINE CLOUDS PATTERN ALONG THE COAST AND LOCALLY INLAND. EXPECT TEMPERATURES TO REMAIN SLIGHTLY ABOVE NORMAL THROUGH NEXT WEEKEND AND EARLY NEXT WEEK WITH INLAND HIGHS IN THE MID TO UPPER 80S AND IN THE MID 60S ALONG THE COAST. MONSOONAL MOISTURE DRIFTS NORTH SUN AFTERNOON...BRINGING A THREAT OF WEAK CONVECTION OVER THE CREST OF THE LANE COUNTY CASCADES. HELD OFF ON PUTTING ANY MEASURABLE PRECIP IN THE FORECAST RIGHT NOW...BUT WILL NEED TO KEEP AN EYE ON THE OVERALL PATTERN. 27 && .AVIATION...STRATUS OFFSHORE IS WORKING ITS WAY BACK INLAND...WITH THE INLAND STRATUS STARTING TO EXPAND EARLY THIS MORNING. LOCATIONS WITH CLOUDS ARE VFR IN THE 3500-4000 FT RANGE...THOUGH SEEING SIGNS OF LOWERING AT THE COAST AND A POCKET ALONG THE COLUMBIA RIVER REPORTED AT KELSO (KKLS) AND OCCASIONALLY AROUND KTTD. EXPECT STRATUS TO CONTINUE TO EXPAND FOR A LITTLE WHILE LONGER. ANOTHER WEAK UPPER LEVEL DISTURBANCE WILL BE WEAKENING AS IT MOVES THROUGH THE REGION EARLY TODAY...SO EXPECT LOW VFR/POSSIBLY MVFR CIGS WILL AGAIN LINGER THROUGH LATE MORNING. VFR CONDITIONS SHOULD THEN RETURN INLAND DURING THE EARLY AFTERNOON...AND MID TO LATE AFTERNOON AT THE COAST. KPDX AND APPROACHES...LATEST GFS/NAM MOS GUIDANCE STILL SUGGESTS THE POSSIBILITY OF AN MVFR DECK...THOUGH SHORT TERM RAP AND LAMP GUIDANCE SUPPORT OBSERVATIONS THAT THE TERMINAL SHOULD GENERALLY REMAIN VFR WITH A DECK AROUND 3500 FT THIS MORNING...AND THAT THE LOWER CLOUDS SHOULD MOSTLY REMAIN SCATTERED. CURRENT TAF HAS REMOVED THE BROKEN MVFR CEILING AS CONFIDENCE IS LOWER NOW THAT SUNRISE IS UPON US...BUT IT STILL POSSIBLE THE DECK WILL LOWER ENOUGH FOR A SHORT TIME THIS MORNING. KMD && .MARINE...HIGH PRESSURE REMAINS OVER THE THE WATERS WITH WEAK LOW PRESSURE INLAND. AS THERMAL LOW PRESSURE OVER NORTHERN CALIFORNIA STRENGTHENS...BRIEF BOUTS OF STRONGER NORTHERLY WINDS MAY DEVELOP IN THE AFTERNOONS AND EVENINGS OVER THE NEXT FEW DAYS. EXPECT WIND GUSTS NEARING 25 KT FROM TIME TO TIME LATER TODAY...MAINLY SOUTH OF KONP...AND WILL CONTINUE THE MARGINAL SMALL CRAFT ADVISORY ALREADY ISSUED. SEAS REMAIN VERY LOW THROUGH EARLY TOMORROW BUT AS NW WINDS INCREASE TOMORROW AND WEDNESDAY AFTERNOON/EVENING...EXPECT WIND WAVES TO ALSO INCREASE A BIT. LONG PERIOD SWELL FROM THE SOUTHWEST WILL CONTINUE FOR THE NEXT FEW DAYS. KMD/JFP && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 2 PM THIS AFTERNOON TO 11 PM PDT THIS EVENING FOR COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM-WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM. && MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
725 PM EDT WED AUG 1 2012 .SYNOPSIS... A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION TONIGHT...THEN WEAK HIGH PRESSURE WILL BUILD OVER THE AREA THURSDAY THROUGH SATURDAY. THE HIGH PRESSURE WILL START TO BREAK DOWN FROM THE NORTHWEST ON SUNDAY...WITH A SURFACE COLD FRONT APPROACHING THE REGION MONDAY...AND LINGERING IN THE VICINITY THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 2330 UTC UPDATE...POPS HAVE BEEN REDUCED EARLY ON EVERYWHERE BASED ON RADAR TRENDS IN EAST TN. POPS HAVE BEEN REDUCED EAST OF THE MOUNTAINS LATER THE IS EVENING AS THE SURVIVAL OF CONVECTION CROSSING THE MOUNTAINS AS HEATING BATES IS IN QUESTION. SKY COVER HAS BEEN UPDATED FROM SATELLITE IMAGERY. WINDS WERE UPDATED FROM A BLEND OF THE 18Z NAM AND THE 12Z ADJMAV. AS OF 220 PM EDT...THE RAP CURRENTLY SHOWS A WEAK H5 SHORT WAVE OVER THE NC MTNS. A STRONGER WAVE IS UPSTREAM OF THE REGION OVER NRN KY. AN ENHANCED CU FIELD IS BEGINNING TO DEVELOP OVER NRN TN...SE KY AND SW VA AHEAD OF THIS SHORT WAVE. THE 0-6KM EFFECTIVE SHEAR IS ON THE ORDER OF 30 KTS WITH THIS FEATURE...AND I/D EXPECT THAT CONVECTION WILL MAKE IT INTO THE MTNS BY EARLY EVENING. MORE ISOLATED CONVECTION MAY ALSO DEVELOP OVER THE NEXT COUPLE HOURS ACROSS THE HIGH TERRAIN...BUT THE MORE ORGANIZED CONVECTIVE ACTIVITY SHOULD BEGIN TO AFFECT THE WRN CAROLINAS AROUND 6 PM. CONFIDENCE IN AN ORGANIZED MCS AFFECTING A LARGE AREA ISN/T THAT HIGH...THOUGH IT/S NOT OUT OF THE QUESTION. HOWEVER...BEEFIER HIGH CHANCE POPS SEEM REASONABLE OVER THE MOUNTAINS...AND STORMS COULD LAST A WAYS INTO THE OVERNIGHT PERIOD OVER THE FOOTHILLS AND PIEDMONT AS WELL. A FEW OF THE STORMS WILL PRODUCE DAMAGING WINDS AS THE DCAPE VALUES RANGE FROM 1000-1200 ACROSS THE REGION. THIS WILL BE ADDED TO THE HWO. H5 HEIGHTS RISE A LITTLE TOMORROW AS THE SRN PLAINS RIDGE WILL BRIEFLY PUSH TO THE EAST. HOWEVER...A WEAK SFC FRONT WILL SET UP OVER THE FOOTHILLS. THE NAM GENERATES GOOD CONVERGENCE OVER THE FOOTHILLS AND PIEDMONT IN THE AFTN. THE MASS AND MOISTURE CONVERGENCE RESULTS IS CONSIDERABLE CONVECTIVE COVERAGE ON THAT MODEL EAST OF THE MTNS LATE IN THE DAY. EVEN THE SREF IS SHOWING SOME FAIRLY HIGH 3-HLY POPS. THEREFORE I/VE RAISED POPS INTO THE LOW CHANCE RANGE OVER PARTS OF THE I-85 URBAN CORRIDOR FOR TMRW. IT WILL ALSO BE A HOT DAY WITH MANY FOOTHILL AND PIEDMONT LOCATIONS WARMING INTO THE MID 90S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... AS OF 230 PM EDT WED...THE OVERALL PATTERN THROUGH THE SHORT RANGE CONTINUES TO SHOW A WEAKNESS ALONG THE EAST COAST BETWEEN TWO RIDGES TO OUR EAST AND WEST. EXPECT ISOLATED CONVECTION TO DIMINISH THURSDAY EVENING WITH THE LOSS OF HEATING. FRIDAY LOOKS MORE FAVORABLE FOR A LARGER NUMBER OF STORMS. THE MODELS SHOW SOME SORT OF SHORT WAVE MOVING ACROSS THE TN VALLEY AND CUMBERLAND PLATEAU IN THE AFTERNOON...WHICH SHOULD HELP TO ORGANIZE STORMS OVER THE MTNS. ONCE FORMED...THE STORMS SHOULD SPREAD OUT ACROSS THE FOOTHILLS AND PIEDMONT LATE IN THE DAY IN THE USUAL MANNER. TEMPS WERE NUDGED TOWARD A GUIDANCE BLEND...WHICH WAS A FEW DEGREES COOLER THAN THE PREVIOUS FCST. THE WAVE DAMPENS OUT ON SATURDAY BUT MOISTURE IS DEEPER WITH A MORE SW FLOW AT LOW LEVELS. WE SHOULD SEE AN INCREASE IN UPPER DIVERGENCE LATE IN THE DAY. THIS SHOULD LEAD TO COVERAGE A BIT BETTER YET THAN FRIDAY...SO POP WAS RAISED WELL INTO THE CHANCE RANGE. TEMPS WERE KEPT NEAR THE OLD FCST. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 200 PM EDT WED...THE LATEST MEDIUM RANGE MODELS CONTINUE TO INDICATE THAT A DEEP MOIST SW FLOW REMAINS IN PLACE OVER THE REGION THROUGH THE WEEKEND AS WEAK RIDGE OF HIGH PRESSURE PERSISTS OVER THE SOUTHEASTERN STATES. THE HEIGHTS WILL GRADUALLY FALL SUN INTO MON AS A STRONG NORTHERN STREAM UPPER LOW PRESSURE MOVES THROUGH THE GREAT LAKES REGION. A COLD FRONT WILL APPROACH FROM THE NW ON LATE SUNDAY AND LIKELY STALL IN OR JUST NORTH OF THE AREA THROUGH WEDNESDAY. HAVE MENTIONED HEALTHY DIURNAL SCATTERED POPS EACH AFTN/EVENING AS MODEL SOUNDINGS SHOW HIGH PW VALUES (OVER 2 INCHES) AND MODERATE INSTABILITY ACROSS OUR CWA. TEMPERATURES WILL REMAIN NEAR...OR A COUPLE DEGREES BELOW SEASONAL AVERAGES THROUGH THE PERIOD. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AT KCLT...LESS CONFIDENCE EXISTS FOR EVENING CONVECTION BASED ON RADAR TREND...AND THE TAF WILL REFLECT THIS. MODEL GUIDANCE GENERALLY FAVORS MVFR VSBY IN FOG AT DAYBREAK...BUT NOT A CIG RESTRICTION. MORE CONVECTION IS EXPECTED ON THURSDAY AS THE REMAINS OF A FRONT ARRIVE FROM THE NORTH...BUT AT THIS TIME CONFIDENCE IS NOT HIGH ENOUGH TO SUPPORT. WINDS WILL BACK FROM WSW TO MORE OF A SOUTHERLY COMPONENT. ELSEWHERE...CONVECTIVE CHANCES WILL BE GREATEST IN THE MOUNTAINS THIS EVENING...BUT BASED ON TRENDS...NOT HIGH ENOUGH TO MENTION. GUIDANCE IS SUPPORTIVE OF MVFR FOG AT DAYBREAK...EXCEPT LIFR TO VLIFR IN MOUNTAIN VALLEYS. CIG RESTRICTIONS WERE NOT FAVORED BY GUIDANCE...BUT WILL BE CARRIED AT KAVL PER TRENDS LAST NIGHT. ANOTHER ROUND OF CONVECTION IS EXPECTED THURSDAY AFTERNOON WITH THE REMAINS OF A COLD FRONT DROPPING SOUTH...BUT CONFIDENCE IS NOT HIGH ENOUGH TO SUPPORT A PROB30 FOR THUNDER. WINDS WILL BACK FROM A WESTERLY COMPONENT TO A SOUTHERLY ONE. OUTLOOK...SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG. AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)... WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JOH NEAR TERM...JAT/MCAVOY SHORT TERM...PM LONG TERM...JOH AVIATION...JAT
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1220 AM CDT TUE JUL 31 2012 .DISCUSSION.../ISSUED AT 951 PM CDT/ FORECAST IN PRETTY GOOD SHAPE THIS EVENING...ALTHOUGH SEEING TEMPS DROP OFF MORE QUICKLY THAN EXPECTED IN A FEW PLACES. HAVE TWEAKED HOURLY GRIDS ACCORDINGLY...WITH MINOR UPDATES TO LOW TEMPERATURES. WITH THE COOLING...LIGHT WINDS...AND RECENT RAINS ACROSS THE EAST... HAVE ADDED SOME PATCHY FOG INTO SOME OF OUR MN/IA COUNTIES AGAIN FOR LATE TONIGHT..AND UPDATED GRIDS/ZFP/PFM HAVE BEEN SENT FOR THAT. && .AVIATION.../FOR THE 06Z TAF ISSUANCE/ VFR CONDITIONS WILL PREVAIL THROUGH 06Z WEDNESDAY...WITH LIGHT SOUTH SOUTHEAST WINDS EXPECTED DURING THE DAY TUESDAY. && .PREV DISCUSSION.../ISSUED AT 315 PM CDT/ SURFACE FRONT MOVING THROUGH NORTHWEST IOWA AS OF 19Z WITH MAIN PUSH OF COOLER AIR APPROACHING I90. THE COOLER AIR SHOULD SPREAD SOUTH ACROSS THE CWA OVERNIGHT WITH LOWS EXPECTED TO BE IN THE LOWER TO MID 60S. WILL KEEP A VERY SMALL CHANCE OF STORMS ACROSS FAR SOUTHEAST CWA THROUGH EARLY EVENING AS LATEST SATELLITE SHOWING SOME ACCAS TRYING TO FORM FROM SOUTH OF SPW TO NEAR SUX AND WITH TEMPERATURES GETTING CLOSE TO BREAKING CAP THERE CAN NOT RULE A FEW STORMS YET LATE THIS AFTERNOON AND EARLY EVENING AS WEAK WAVE DROPS SOUTHEAST INTO SOUTHWEST MINNESOTA WHICH ALSO SHOWS UP WELL ON SATELLITE. LATEST HRRR MODELS CONTINUES TO CONFIRM THIS POSSIBILITY. OTHERWISE...EXPECT MOSTLY CLEAR SKIES OVERNIGHT. SOMEWHAT ACTIVE WEATHER PATTERN EXPECTED INTO THE END OF THE WEEK AS THE PATTERN TRANSITIONS FROM A SHARP HIGH PLAINS RIDGE INTO A MORE ZONAL PATTERN BY LATE WEEK. IN THE SHORT RANGE...EXPECT A FEW FAIRLY WEAK WAVES TO DROP SOUTHEAST FROM SOUTHERN CANADA INTO THE NORTHERN PLAINS. AS IS TYPICAL FOR THESE WEAK WAVE SCENARIOS...MODELS NOT SHOWING MUCH CONSISTENCY IN THE TIMING AND TRACK OF THESE WAVES DURING THE MID WEEK. GIVEN THE MEAGER MOISTURE...CONDITIONAL INSTABILITY AND MODEL UNCERTAINTY...IT IS HARD TO PINPOINT ANY ONE TIME FRAME AS THE "BETTER" POTENTIAL FOR SHOWER OR THUNDERSTORM ACTIVITY. WITH THIS IN MIND...WILL KEEP ISOLATED POPS IN THE FORECAST JUST ABOUT EVERY PERIOD FROM TUESDAY NIGHT THROUGH THURSDAY. ANY ACTIVITY THAT MANAGES TO DEVELOP SHOULD BE HIGH BASED AND NOT A HEAVY RAIN PRODUCER. HIGHS WILL BE QUITE WARM ON WEDNESDAY WITH THE 90S TO NEAR 100 EXPECTED...AND WILL BE AROUND 5 DEGREES COOLER ON THURSDAY. LATE IN THE WEEK MARKS THE APPROACH OF A CUT OFF UPPER LOW WHICH DIGS ALONG THE CANADIAN BORDER WITH MONTANA ON FRIDAY THEN HEADS INTO THE NORTHERN GREAT LAKES BY SATURDAY NIGHT. THERE ARE SOME FAIRLY SIGNIFICANT MODEL DIFFERENCES WITH THIS SYSTEM. THE LATEST ECMWF...ONCE THE FASTEST SOLUTION...IS NOW 6 TO 12 HOURS SLOWER AND IS THE WEAKEST SOLUTION. THE GEM TAKES THE LOW FARTHER SOUTH INTO THE NORTHERN PLAINS WHILE THE GFS IS SLIGHTLY STRONGER AND THE MOST NORTHERN TRACK. ALL OF THESE SOLUTIONS DO SEND A FAIRLY STRONG FRONT THROUGH THE FORECAST AREA FRIDAY NIGHT OR SATURDAY WHICH APPEARS TO BE THE BEST POTENTIAL FOR SOME WET WEATHER IN THE NEXT SEVEN DAYS. WILL CONTINUE CARRYING LIKELY POPS FRIDAY NIGHT IN OUR NORTHERN HALF WITH CHANCES ELSEWHERE. WITH THE INCREASED CLOUD COVERAGE AND RAINFALL CHANCES FRIDAY AND SATURDAY...AS WELL AS COOLER NORTHWEST FLOW WORKING INTO THE AREA SATURDAY AND SUNDAY...TEMPERATURES WILL BE MUCH CLOSER TO NORMALS INTO THE WEEKEND. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
631 PM CDT WED AUG 1 2012 .UPDATE... UPDATE TO ADJUST POPS FOR OVERNIGHT AND REFOCUS SEVERE WEATHER POTENTIAL TO THE NORTHWEST. && .DISCUSSION... A NEW CLUSTER OF STRONG TO SEVERE THUNDERSTORMS HAS DEVELOPED OVER SOUTHERN MISSOURI INTO NORTH CENTRAL ARKANSAS. THIS CONVECTION IS LIKELY BEING FORCED BY AN MCV (MESOSCALE CONVECTIVE VORTEX)/SHORTWAVE OVER SOUTHWEST MISSOURI. THIS FEATURE WILL CONTINUE TO DROP SOUTHEAST THIS EVENING AND LIKELY WILL SUPPORT SCATTERED THUNDERSTORMS OVER WESTERN SECTIONS OF THE FORECAST AREA THIS EVENING AND OVERNIGHT. PLAN TO ADD POTENTIAL FOR SEVERE STORMS OVER THESE LOCATIONS IN AN UPDATED HAZARDOUS WEATHER OUTLOOK. THINK THE PRIMARY TIMING OF SEVERE WEATHER POTENTIAL WILL BE THIS EVENING...ALTHOUGH MAY LINGER LATER INTO THE NIGHT IF A STRONG COLD POOL IN GENERATED BY ONGOING CONVECTION. THE ATMOSPHERE OVER WESTERN AREAS HAS RECOVERED FROM MORNING CONVECTION AND LATEST MESOANALYSIS INDICATES THAT GREATER THAN 2500 J/KG OF MLCAPE EXISTS. IN ADDITION...MID LEVEL COOLING/MODEST HEIGHT FALLS ASSOCIATED WITH THE DISTURBANCE MAY FURTHER SUPPORT LONGEVITY THROUGH THE EVENING OF STORMS. UPDATED ZONES AND GRIDS HAVE BEEN SENT WITH HWO UPDATED SHORTLY. THE REMAINDER OF SEVERE THUNDERSTORM WATCH 547 HAS BEEN CANCELLED OVER NORTHEAST MISSISSIPPI AS STORMS HAVE PUSHED SOUTHEAST. JLH && .PREV DISCUSSION... /ISSUED 411 PM CDT WED AUG 1 2012/ DISCUSSION... A CLUSTER OF SEVERE STORMS HAS DEVELOPED THIS AFTERNOON OVER PORTIONS OF WEST TENNESSEE INTO NORTHEAST MISSISSIPPI. THESE STORMS HAVE FORMED ALONG AN OLD CONVECTIVE OUTFLOW BOUNDARY FROM LAST NIGHTS STORMS THAT OCCURRED WEST OF THE MISSISSIPPI RIVER. THESE STORMS CONTINUE TO WORK ON A STRONGLY UNSTABLE AIRMASS REPRESENTED BY MLCAPE VALUES IN EXCESS OF 3000 J/KG. THE SEVERE WEATHER THREAT SHOULD MOVE SOUTHEAST OF OUR FORECAST AREA LATER THIS EVENING. ATTENTION WILL THEN TURN UPSTREAM TOWARDS NORTHEAST ARKANSAS FOR LATE TONIGHT AS ADDITIONAL CONVECTION MAY DEVELOP OVER MISSOURI AFTER MIDNIGHT. THE MID SOUTH WILL REMAIN POSITIONED ALONG THE EASTERN PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTHERN PLAINS. A SERIES OF MID LEVEL SHORTWAVE DISTURBANCES WILL TRAVERSE ACROSS THE REGION THROUGH THE REMAINDER OF THE WEEK INTO NEXT WEEKEND. THE FIRST OF SUCH SHORTWAVES IS CURRENTLY EVIDENT ACROSS WESTERN MISSOURI ALONG WITH AN ASSOCIATED MCV (MESOSCALE CONVECTIVE VORTEX). MODELS CONTINUE TO INDICATE THAT A LOW LEVEL JET WILL STRENGTHEN LATER TONIGHT OVER THE SOUTHERN PLAINS AND NOSE INTO A STALLED SURFACE BOUNDARY STRETCHED ACROSS SOUTHERN MISSOURI INTO SOUTHERN KENTUCKY. NEW THUNDERSTORM DEVELOPMENT CAN BE EXPECTED LATER THIS EVENING OVER SOUTHERN MISSOURI WHICH SHOULD DROP SOUTHEAST INTO NORTHWEST PORTIONS OF THE MID SOUTH AFTER MIDNIGHT IN NORTHWEST FLOW ALOFT. THIS CLUSTER WILL DIMINISH ACROSS WESTERN AREAS DURING THURSDAY MORNING BUT NEW CONVECTION MAY INITIATE DURING PEAK HEATING AGAIN OVER PORTIONS OF THE REGION ALONG CONVECTIVE OUTFLOWS. HOT AND HUMID WEATHER WILL CONTINUE WITH HEAT INDEX VALUES AGAIN REACHING OR EXCEEDING 105 DEGREES IN MOST AREAS. THE HEAT ADVISORY HAS BEEN EXTENDED THROUGH 7 PM THURSDAY. ANOTHER MORE SIGNIFICANT SHORTWAVE ROUNDS THE TOP OF THE RIDGE ON THURSDAY NIGHT INTO FRIDAY. THIS SHOULD AGAIN GENERATE ADDITIONAL SHOWERS AND THUNDERSTORMS. THE ATMOSPHERE SHOULD REMAIN UNSTABLE SO A FEW SEVERE STORMS CANNOT BE RULED OUT. THE THIRD MOST SIGNIFICANT WAVE SHOULD APPROACH ON SUNDAY AND FORCE A COLD FRONT INTO THE REGION. ONCE AGAIN...SCATTERED CONVECTIVE COVERAGE WITH A SEVERE POTENTIAL CAN BE EXPECTED. THE FRONT SHOULD DROP INTO SOUTHERN PORTIONS OF THE AREA BY EARLY NEXT WEEK AS THE UPPER RIDGE REBUILDS BACK INTO THE AREA FROM THE WEST. THIS WILL BRING AN END TO THE CONVECTIVE CHANCES AND ALLOW TEMPERATURES TO AGAIN HEAT UP FOR THE END OF THE EXTENDED FORECAST PERIOD. JLH && .AVIATION... 18Z TAF SET SHRAS CONTINUE TO DRIFT SOUTHEASTWARD ACROSS THE CWA. THE SHRAS ARE ASSOCIATED WITH A DISTURBANCE. BOTH THE HRRR AND NAM SHOW THAT ACTIVITY MAY BLOSSOM OVER THE NEXT COUPLE OF HOURS AS THE DISTURBANCE INTERACTS WITH DAYTIME HEATING. AN ANOTHER DISTURBANCE CURRENTLY OVER EASTERN KANSAS MAY ALSO MOVE INTO THE AREA LATER TONIGHT FOLLOWED BY ANOTHER ONE BY 12Z. THIS GIVES AT LEAST KJBR AND POSSIBLY KMEM MULTIPLE CHANCES OF SEEING A SHRA/TSRA. PINPOINTING TIMING TOO HARD AT THIS POINT. WILL HAVE TEMPO GOING AT ONSET OF TAFS FOR WHAT IS CURRENTLY GOING ON THEREAFTER WILL JUST USE VICINITY WORDING. SOME PATCHY FOG MAY ALSO DEVELOP AT KMKL OVERNIGHT. KRM && .PRELIMINARY POINT TEMPS/POPS... MEM 78 96 77 96 / 30 30 30 40 MKL 74 97 75 93 / 20 20 30 50 JBR 74 95 74 96 / 40 30 40 40 TUP 73 98 74 94 / 20 20 20 40 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS- MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN- TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1257 PM EDT TUE JUL 31 2012 .SYNOPSIS... AN UPPER LEVEL TROUGH WILL KEEP THE AREA IN A FAVORED PATTERN FOR SCATTERED SHOWERS AND STORMS INTO WEDNESDAY. A FRONT WILL APPROACH THE AREA WEDNESDAY BEFORE DISSIPATING. FOR LATE WEEK...THE HEAT RIDGE STARTS TO BE MORE OF INFLUENCE INTO OUR AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 925 AM EDT TUESDAY... ALREADY SEEING SHRA/TSRA DEVELOP OVER THE FAR WEST IN THE WEAK CONVERGENCE ZONE/85H THETA-E RIDGE NORTH OF THE MCS PASSING ACROSS THE SE STATES. EXPECT WITH CONTINUED HEATING WILL SEE CONVECTION ORGANIZE MORE OVER THE SW AND GRADUALLY UNZIP TO THE NE ESPCLY OVER THE MOUNTAINS AS THE NEXT PIECE OF UPPER TROFFINESS SLIDES EAST. JUST HOW MUCH INTERACTION BETWEEN THE TWO OCCURS WILL DETERMINE COVERAGE/STRENGTH OF STORMS GIVEN LOWER WET BULBS BUT SLIGHTLY BETTER FLOW ALOFT THIS AFTERNOON. THINK NEXT SHORTWAVE AND ASSOCIATED OUTFLOW TO THE NW PER VIS PICS SHOULD KEEP MOST OF THAT COVERAGE TO THE WEST UNTIL LATE SO MAINLY LOOKING AT SCATTERED MULTICELLULAR ACTION MAINLY MOUNTAINS WITH RENEWED COVERAGE DRIVEN BY OUTFLOW. CURRENT FOG/STABILITY OUT EAST WILL LIKELY LIMIT DEVELOPMENT EAST OF THE BLUE RIDGE AS COVERAGE THERE LOOKS TO COME FROM CELLS HEATING OFF THE BLUE RIDGE LATER ON. LATEST HRRR LOOKS TO SUPPORT THIS SCENARIO SO UPPED POPS TO LOW LIKELYS IN A STRIP OUT EAST AND TRENDED DOWN TO JUST LOW CHANCE SE PIEDMONT. STRONGER CELLS SHOULD AGAIN BE ABLE TO TAP SOME DRY AIR ALOFT AND WITH COOLER AIR ALOFT UNDER THE TROF AXIS LIKELY MORE OF A HAIL THREAT AS WELL SO KEEPING HWO MENTION. KEPT HIGHS CLOSER TO THE COOLER MET MOS GIVEN CLOUDS/SHRA WEST IN SPOTS AND WIDESPREAD STRATUS/FOG EAST TO INIT BUT STILL EXPECTING MOST IN THE 80S BY LATE IN THE DAY. AS OF 725 AM EDT TUESDAY... TWO SHORTWAVES THIS MORNING CAUSING SHOWERS/TSRA OUTSIDE OUR FORECAST AREA. MAIN ONE IS SOUTHWEST OF US IN THE TN VALLEY CREATING SHRA/TSRA A COUPLE OF COUNTIES SOUTH OF WATAUGA...WITH ANOTHER WEAK WAVE INDUCING SHOWERS IN WEBSTER COUNTY WV. THE THREAT OF SHOWERS/STORMS INCREASES AROUND LATE MORNING...WITH BEST THREAT IN THE MTNS...WITH ISOLATED COVERAGE IN THE PIEDMONT. PREVIOUS DISCUSSION... VERY LITTLE ON RADAR THIS MORNING WITH ONE LONE SHOWER UP NORTH OF CHARLOTTESVILLE VA...WITH GENERALLY PC SKIES ACROSS THE FORECAST AREA. MAIN AXIS OF PRECIP AND UPPER LEVEL ENERGY RESIDES ACROSS SRN KY INTO TN THIS MORNING AND THIS SHORTWAVE IS ANTICIPATED TO SLIDE SOUTHEAST TOWARD GA/SC LATER THIS MORNING. MODELS SHOWING SOME AGREEMENT IN KEEPING THE BEST THREAT OF PRECIP ACROSS THE MTNS TODAY...WITH BEST SUPPORT IN THE NC MTNS. HAVE GONE WITH 40/50 POPS IN THE MTNS WITH 30 OUT EAST...BUT LOOKING AT LATEST LOCAL WRF TRENDS AND WV LOOP LEADS ME TO THINK THAT COVERAGE ESPECIALLY EAST OF THE BLUE RIDGE TODAY MAY BE ISOLATED. WENT A LITTLE CLOUDIER TODAY IN THE MTNS...AND LEANED TOWARD THE COOLER MET/LOCAL MOS NUMBERS HERE WITH LOWER-MID 80S FOR HIGHS AND EVEN 70S ACROSS THE NC MTNS PER BETTER CONVECTION THREAT. THE EAST SHOULD REACH THE UPPER 80S. TONIGHT...THE CONVECTION SHOULD WANE ACROSS THE AREA WITH DEPARTING SHORTWAVE BUT WILL HAVE TO KEEP AN EYE ON THE CURRENT MCS AND ASSOCIATED VORT/COLD FRONT MOVING ACROSS MICHIGAN AND SRN WISCONSIN THIS MORNING. THE ECMWF/NAM TRACK THIS SYSTEM SOUTHEAST INTO THE WV MTNS AFTER MIDNIGHT TONIGHT BUT THEN DISSIPATE IT. I AM INCLINED TO HAVE AT LEAST CHANCE POPS IN THE WEST VIRGINIA/VA HIGHLANDS AREA WITH SLIGHT CHANCE TO THE SOUTHEAST OF THIS AREA OVERNIGHT...THEN TAPER IT OFF AROUND DAWN WED. KEPT LOWS IN THE 60S AREAWIDE SIMILAR TO MOS NUMBERS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 255 AM EDT TUESDAY... WEDNESDAY INTO WEDNESDAY NIGHT...A GENERAL PATTERN OF TROUGHINESS IN THE EAST CONTINUES...WHILE AN UPPER RIDGE REMAINS PARKED OVER MUCH OF THE TEXAS AND FOUR CORNERS REGION. A COLD FRONT ASSOCIATED WITH THE EAST COAST TROUGH WILL SWING THROUGH THE AREA ON WEDNESDAY BRINGING SCATTERED SHOWERS AND STORMS. THE LATEST DAY 2 CONVECTIVE OUTLOOK FROM THE STORM PREDICTION CENTER SUGGESTS LAPSE RATES MAY BE STEEP ENOUGH FOR SOME LOCALIZED ENHANCED CONVECTION THAT YIELDS SEVERE WINDS AND HAIL. TEMPERATURES WILL TREND A BIT WARMER AS COMPARED TO TUESDAY IN ADVANCE OF THE APPROACHING COLD FRONT. DAYTIME CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH ISOLATED SHOWERS AND STORMS CONTINUING ACROSS SOUTHERN AND EASTERN PARTS OF THE AREA NEAREST THE EXITING COLD FRONT. ANTICIPATE PRECIPITATION TO END BY MIDNIGHT WITH DECREASING CLOUD COVER. FOG DEVELOPMENT WILL BE LIKELY DURING THE EARLY MORNING HOURS OF THURSDAY...ESPECIALLY ACROSS THE MOUNTAINS VALLEYS AND THE RIVER VALLEYS OF THE PIEDMONT. THURSDAY INTO FRIDAY...THE EAST COAST TROUGH WILL FLATTEN A BIT AS THE UPPER RIDGE SHIFTS EAST INTO THE LOWER MISSISSIPPI VALLEY. ANTICIPATE A TREND TOWARD HOTTER TEMPERATURES. OTHER THAN SOME ISOLATED SHOWERS AND STORMS IN THE NORTHERN MOUNTAINS OF NORTH CAROLINA...DRY CONDITIONS ARE EXPECTED ON THURSDAY. BY FRIDAY...A RETURN FLOW IS EXPECTED AS THE CENTER OF SURFACE HIGH PRESSURE SHIFTS EAST A SHORTWAVE TROUGH MOVES EASTWARD WITHIN A ZONAL FLOW THROUGH THE OHIO VALLEY. LOOK FOR THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND STORMS ONCE AGAIN. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 230 PM EDT MONDAY... WITH MORE PERSISTENT SOUTHERLY FLOW DEVELOPING INTO THE WEEKEND...DEWPOINTS WILL BE ON THE RISE AND SO WILL INSTABILITY AS RH INCREASES AT H7 AND H5. SHOWERS AND STORMS WILL BE MORE NUMEROUS ON SUNDAY IN COMPARISON TO SATURDAY. ALTHOUGH H85 TEMPS MAY RISE A FEW MORE DEGREES...MAX T WILL BE STUNTED BY MORE CLOUDS AND THUNDERSTORMS. A COLD FRONT DROPS OUT OF THE GREAT LAKES EARLY NEXT WEEK...SUCH THAT SHOWERS AND STORMS WILL BE MOST LIKELY ON MONDAY AND MONDAY NIGHT. HIGH TEMPS SHOULD BE IN THE MIDDLE 80S TO LOWER 90S THROUGH THE PERIOD. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 1235 PM EDT TUESDAY... LOW CIGS CONTINUE TO SLOWLY IMPROVE TO VFR ESPCLY ALONG AND EAST OF THE BLUE RIDGE WHERE FOG/STRATUS HAVE BEEN STUCK FOR MUCH OF THE MORNING. EXPECT THIS TREND TO PREVAIL INTO THE AFTERNOON WITH MAINLY 4-6K FT CU FIELDS FOR MOST SPOTS UNTIL LOSS OF HEATING. THE MAIN THREAT OF SLOW MOVING MULTICELLULAR STORMS CONTINUES IN THE WESTERN LOCATIONS ALONG AND SOUTH OF A LINE FROM KLWB-KBCB THIS AFTERNOON. OVERALL...COVERAGE WILL BE SCATTERED ELSEWHERE BUT CONFIDENCE IS HIGH THAT SHOWERS AND STORMS WILL BE IN THE VICINITY OF ALL MOST TAF SITES IN THE AFTN SO KEPT IT IN. SHOULD SEE A QUICK WEAKENING TREND TO CONVECTION THIS EVENING AS THE SHORTWAVE PASSES. HOWEVER...ANOTHER SHORTWAVE UPSTREAM MAY BRING SHOWERS INTO THE KLWB/KBLF AREA THROUGH LATE THIS EVENING. CIGS MAY DROP AGAIN LATE TUE NIGHT AS WELL AS VSBYS DEPENDING ON EXTENT OF RAINFALL...AND CLEARING SKIES SO LOWERED CIGS/VSBYS TO IFR/MVFR MOST SPOTS EXCLUDING KROA BUT NOT AS LOW AS LAST NIGHT. THE DAILY AFTERNOON AND EVENING THREAT OF SHOWERS AND THUNDERSTORMS CONTINUES THROUGH THE WEEK BUT SHOULD BECOME MORE WIDELY SCATTERED WEDNESDAY...AND ISOLATED THURSDAY INTO FRIDAY AS WEAK HIGH PRESSURE SETTLES IN FROM THE WEST. MOISTURE WILL BEGIN TO RETURN OVER THE WEEKEND WITH DIURNAL BOUTS OF SHOWERS AND STORMS LIKELY WITH MOSTLY AFTERNOON/EVENING MVFR CONDITIONS POSSIBLE AT TIMES SATURDAY AND SUNDAY. OUTSIDE OF THIS MAINLY DIURNALLY DRIVEN CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE FROM OVERNIGHT VALLEY FOG. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...JH/WP SHORT TERM...JC LONG TERM...KM AVIATION...AMS/JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
950 AM EDT TUE JUL 31 2012 .SYNOPSIS... AN UPPER LEVEL TROUGH WILL KEEP THE AREA IN A FAVORED PATTERN FOR SCATTERED SHOWERS AND STORMS INTO WEDNESDAY. A FRONT WILL APPROACH THE AREA WEDNESDAY BEFORE DISSIPATING. FOR LATE WEEK...THE HEAT RIDGE STARTS TO BE MORE OF INFLUENCE INTO OUR AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 925 AM EDT TUESDAY... ALREADY SEEING SHRA/TSRA DEVELOP OVER THE FAR WEST IN THE WEAK CONVERGENCE ZONE/85H THETA-E RIDGE NORTH OF THE MCS PASSING ACROSS THE SE STATES. EXPECT WITH CONTINUED HEATING WILL SEE CONVECTION ORGANIZE MORE OVER THE SW AND GRADUALLY UNZIP TO THE NE ESPCLY OVER THE MOUNTAINS AS THE NEXT PIECE OF UPPER TROFFINESS SLIDES EAST. JUST HOW MUCH INTERACTION BETWEEN THE TWO OCCURS WILL DETERMINE COVERAGE/STRENGTH OF STORMS GIVEN LOWER WET BULBS BUT SLIGHTLY BETTER FLOW ALOFT THIS AFTERNOON. THINK NEXT SHORTWAVE AND ASSOCIATED OUTFLOW TO THE NW PER VIS PICS SHOULD KEEP MOST OF THAT COVERAGE TO THE WEST UNTIL LATE SO MAINLY LOOKING AT SCATTERED MULTICELLULAR ACTION MAINLY MOUNTAINS WITH RENEWED COVERAGE DRIVEN BY OUTFLOW. CURRENT FOG/STABILITY OUT EAST WILL LIKELY LIMIT DEVELOPMENT EAST OF THE BLUE RIDGE AS COVERAGE THERE LOOKS TO COME FROM CELLS HEATING OFF THE BLUE RIDGE LATER ON. LATEST HRRR LOOKS TO SUPPORT THIS SCENARIO SO UPPED POPS TO LOW LIKELYS IN A STRIP OUT EAST AND TRENDED DOWN TO JUST LOW CHANCE SE PIEDMONT. STRONGER CELLS SHOULD AGAIN BE ABLE TO TAP SOME DRY AIR ALOFT AND WITH COOLER AIR ALOFT UNDER THE TROF AXIS LIKELY MORE OF A HAIL THREAT AS WELL SO KEEPING HWO MENTION. KEPT HIGHS CLOSER TO THE COOLER MET MOS GIVEN CLOUDS/SHRA WEST IN SPOTS AND WIDESPREAD STRATUS/FOG EAST TO INIT BUT STILL EXPECTING MOST IN THE 80S BY LATE IN THE DAY. AS OF 725 AM EDT TUESDAY... TWO SHORTWAVES THIS MORNING CAUSING SHOWERS/TSRA OUTSIDE OUR FORECAST AREA. MAIN ONE IS SOUTHWEST OF US IN THE TN VALLEY CREATING SHRA/TSRA A COUPLE OF COUNTIES SOUTH OF WATAUGA...WITH ANOTHER WEAK WAVE INDUCING SHOWERS IN WEBSTER COUNTY WV. THE THREAT OF SHOWERS/STORMS INCREASES AROUND LATE MORNING...WITH BEST THREAT IN THE MTNS...WITH ISOLATED COVERAGE IN THE PIEDMONT. PREVIOUS DISCUSSION... VERY LITTLE ON RADAR THIS MORNING WITH ONE LONE SHOWER UP NORTH OF CHARLOTTESVILLE VA...WITH GENERALLY PC SKIES ACROSS THE FORECAST AREA. MAIN AXIS OF PRECIP AND UPPER LEVEL ENERGY RESIDES ACROSS SRN KY INTO TN THIS MORNING AND THIS SHORTWAVE IS ANTICIPATED TO SLIDE SOUTHEAST TOWARD GA/SC LATER THIS MORNING. MODELS SHOWING SOME AGREEMENT IN KEEPING THE BEST THREAT OF PRECIP ACROSS THE MTNS TODAY...WITH BEST SUPPORT IN THE NC MTNS. HAVE GONE WITH 40/50 POPS IN THE MTNS WITH 30 OUT EAST...BUT LOOKING AT LATEST LOCAL WRF TRENDS AND WV LOOP LEADS ME TO THINK THAT COVERAGE ESPECIALLY EAST OF THE BLUE RIDGE TODAY MAY BE ISOLATED. WENT A LITTLE CLOUDIER TODAY IN THE MTNS...AND LEANED TOWARD THE COOLER MET/LOCAL MOS NUMBERS HERE WITH LOWER-MID 80S FOR HIGHS AND EVEN 70S ACROSS THE NC MTNS PER BETTER CONVECTION THREAT. THE EAST SHOULD REACH THE UPPER 80S. TONIGHT...THE CONVECTION SHOULD WANE ACROSS THE AREA WITH DEPARTING SHORTWAVE BUT WILL HAVE TO KEEP AN EYE ON THE CURRENT MCS AND ASSOCIATED VORT/COLD FRONT MOVING ACROSS MICHIGAN AND SRN WISCONSIN THIS MORNING. THE ECMWF/NAM TRACK THIS SYSTEM SOUTHEAST INTO THE WV MTNS AFTER MIDNIGHT TONIGHT BUT THEN DISSIPATE IT. I AM INCLINED TO HAVE AT LEAST CHANCE POPS IN THE WEST VIRGINIA/VA HIGHLANDS AREA WITH SLIGHT CHANCE TO THE SOUTHEAST OF THIS AREA OVERNIGHT...THEN TAPER IT OFF AROUND DAWN WED. KEPT LOWS IN THE 60S AREAWIDE SIMILAR TO MOS NUMBERS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 255 AM EDT TUESDAY... WEDNESDAY INTO WEDNESDAY NIGHT...A GENERAL PATTERN OF TROUGHINESS IN THE EAST CONTINUES...WHILE AN UPPER RIDGE REMAINS PARKED OVER MUCH OF THE TEXAS AND FOUR CORNERS REGION. A COLD FRONT ASSOCIATED WITH THE EAST COAST TROUGH WILL SWING THROUGH THE AREA ON WEDNESDAY BRINGING SCATTERED SHOWERS AND STORMS. THE LATEST DAY 2 CONVECTIVE OUTLOOK FROM THE STORM PREDICTION CENTER SUGGESTS LAPSE RATES MAY BE STEEP ENOUGH FOR SOME LOCALIZED ENHANCED CONVECTION THAT YIELDS SEVERE WINDS AND HAIL. TEMPERATURES WILL TREND A BIT WARMER AS COMPARED TO TUESDAY IN ADVANCE OF THE APPROACHING COLD FRONT. DAYTIME CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH ISOLATED SHOWERS AND STORMS CONTINUING ACROSS SOUTHERN AND EASTERN PARTS OF THE AREA NEAREST THE EXITING COLD FRONT. ANTICIPATE PRECIPITATION TO END BY MIDNIGHT WITH DECREASING CLOUD COVER. FOG DEVELOPMENT WILL BE LIKELY DURING THE EARLY MORNING HOURS OF THURSDAY...ESPECIALLY ACROSS THE MOUNTAINS VALLEYS AND THE RIVER VALLEYS OF THE PIEDMONT. THURSDAY INTO FRIDAY...THE EAST COAST TROUGH WILL FLATTEN A BIT AS THE UPPER RIDGE SHIFTS EAST INTO THE LOWER MISSISSIPPI VALLEY. ANTICIPATE A TREND TOWARD HOTTER TEMPERATURES. OTHER THAN SOME ISOLATED SHOWERS AND STORMS IN THE NORTHERN MOUNTAINS OF NORTH CAROLINA...DRY CONDITIONS ARE EXPECTED ON THURSDAY. BY FRIDAY...A RETURN FLOW IS EXPECTED AS THE CENTER OF SURFACE HIGH PRESSURE SHIFTS EAST A SHORTWAVE TROUGH MOVES EASTWARD WITHIN A ZONAL FLOW THROUGH THE OHIO VALLEY. LOOK FOR THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND STORMS ONCE AGAIN. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 230 PM EDT MONDAY... WITH MORE PERSISTENT SOUTHERLY FLOW DEVELOPING INTO THE WEEKEND...DEWPOINTS WILL BE ON THE RISE AND SO WILL INSTABILITY AS RH INCREASES AT H7 AND H5. SHOWERS AND STORMS WILL BE MORE NUMEROUS ON SUNDAY IN COMPARISON TO SATURDAY. ALTHOUGH H85 TEMPS MAY RISE A FEW MORE DEGREES...MAX T WILL BE STUNTED BY MORE CLOUDS AND THUNDERSTORMS. A COLD FRONT DROPS OUT OF THE GREAT LAKES EARLY NEXT WEEK...SUCH THAT SHOWERS AND STORMS WILL BE MOST LIKELY ON MONDAY AND MONDAY NIGHT. HIGH TEMPS SHOULD BE IN THE MIDDLE 80S TO LOWER 90S THROUGH THE PERIOD. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... AS OF 730 AM EDT TUESDAY... FOG/LOW CLOUDS THIS MORNING SHOULD DISSIPATE IN THE 12-14Z TIME FRAME. VFR CONDITIONS EXPECTED ONCE THIS OCCURS AT ALL SITES. THE MAIN THREAT OF STORMS WILL BE IN THE SOUTHWESTERN CWA ALONG AND SOUTH OF A LINE FROM BLF-BCB. OVERALL...COVERAGE WILL BE SCATTERED ELSEWHERE BUT CONFIDENCE IS HIGH THAT SHOWERS AND STORMS WILL BE IN THE VICINITY OF ALL MOST TAF SITES IN THE AFTN SO KEPT IT IN. SHOULD SEE WEAKENING TREND TO CONVECTION THIS EVENING AS SHORTWAVE PASSES. HOWEVER...ANOTHER SHORTWAVE UPSTREAM MAY BRING SHOWERS INTO THE LWB/BLF AREA AFTER 06Z WED. CIGS MAY DROP AGAIN LATE TUE NIGHT AS WELL AS VSBYS DEPENDING ON EXTENT OF RAINFALL...AND CLEARING SKIES. THE DAILY AFTERNOON AND EVENING THREAT OF SHOWERS AND THUNDERSTORMS CONTINUES THROUGH THE WEEK BUT SHOULD BECOME MORE ISOLATED WEDNESDAY AND THURSDAY. WEAK HIGH PRESSURE SETTLES IN FROM THE WEST BY SATURDAY. OUTSIDE OF THIS MAINLY DIURNALLY DRIVEN CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE FROM OVERNIGHT MVFR VALLEY FOG. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...JH/WP SHORT TERM...JC LONG TERM...KM AVIATION...AMS/JH/WP
AREA FORECAST DISCUSSION
NWS SPOKANE WA
242 PM PDT Tue Jul 31 2012 .SYNOPSIS... An upper level low currently over the gulf of Alaska will drop southwest over the next couple days resulting in only a small chance of thunderstorms near the Canadian border. Drier northwest flow will spill into the region Thursday evening and continue through Saturday resulting in dry but locally breezy weather. Warmer and increasingly unsettled conditions could return to the region by Sunday and continuing into early next week. && .DISCUSSION... Tonight...Weak upper level shortwave trough continues to cross Washington this evening and should move into north Idaho around sunset. The big question is will this disturbance be able to trigger a thunderstorm or two. The latest instability numbers from the RUC and LAPS are not terribly impressive...however small pockets of CAPEs around 500 j/kg are located near the Canadian border. The convective caps have been weakening...however up through now...only small cumulus fields have been forming over the higher terrain near the US/Canadian border. We will keep a slight chance of thunder mentioned through early evening near the international border but the remainder of the forecast area will be left dry for the night. fx Wednesday through Friday: Following a quiet, seasonal weather day on Wednesday, our focus will switch gears toward an upper- level trough swinging across southern BC...northeastern WA...and northern ID for Thursday/Thursday night. The midlevel wave will usher a strong cold front through the region resulting in a passing shield of clouds, chance for light showers across the northeastern zones, breezy northerly winds, and a slight chance for post-frontal convection and perhaps an isolated thunderstorm. Dry, northerly flow behind Thursday`s shortwave will promote another day of mostly clear skies and seasonal temperatures. Overall, models are in general agreement through the period and confidence is near to above normal. The center of the upper-low driving the cold front will track S/SE down the BC/Alberta. The tail, or southwestern flank of the strongest synoptic forcing will cross NE WA and N ID Thursday afternoon. There is a modest moisture fetch that becomes entrained into the system with precipitable waters of an inch or higher along the coast...decreasing near 0.80" over N Idaho. Forcing along the cold front in conjunction with large-scale ascent associated with differential PVA will lead to a layer saturation and band of thick clouds passing with the initial 700-500mb cold front. Light showers will be possible within this band but the threat for thunderstorms will be low. As the 500mb cold pool slides over the northeastern zones in the post-frontal air mass Thursday afternoon... there is a chance for convection to fire with forecast soundings via the GFS even supporting a few thunderstorms. The NAM on the other hand, is much quicker to bring a midlevel dry slot into the northeastern zones quickly shutting down any chance for afternoon convection. Given the better agreement amongst the GFS/ECMWF we have trend the forecast toward the later keeping a slight chance for thunderstorms...but confidence is generally below normal related to the thunder threat. The pattern would also favor breezy to gusty winds for the Okanogan Valley given the north to south pressure gradient and cold advection. Consequently, we have increased winds above model guidance to sustained speeds of 10-18 mph with gusts in the 20-30 mph range. While these winds are well below any highlight-able thresholds...it will present an elevated threat for wildfire growth in grass, brush, and other fine fuels given the combination of relative humidities in the 20`s. /sb Friday night through Tuesday: Trough continues to exit to the east along the US/Canadian boarder. A ridge builds in. The thermal trough that has been suppressed to the south for the last several days will once again set up across the intermountain west. Daytime temperatures will warm to slightly above average temps by Saturday. Sunday will be the warmest day with temps 5-9 degrees above average. Monday and Tuesday we will remain above average as well. There are still some model discrepancies of what do do with a low that develops off the northern CA coast. The 12z ECMWF is not as bullish in bringing the low across the entire Pac NW as a weaker open wave. It does show a very weak wave and associated moisture moving up from the desert southwest. It also shows a strong closed low moving south out of Canada and has it moving across northern WA and ID starting early Tuesday. The GFS on the other hand brings some energy and moisture from the desert southwest into our southeastern WA and central ID areas. The possible low from Canada stays way to the north and has no real weather impact on us. Given both models do show the possible monsoonal moisture streaming up with a disturbance, have decided to keep the mention of thunderstorms across the Blue Mountains and the Camas Prairie for Sunday and have increased cloud cover a bit. /Nisbet && .AVIATION... 18Z TAFS...A weak upper level disturbance will track through E WA and N ID through 03z. This will result in a slight chance of -tsra near the Canadian border...but little chance at the TAF sites. Forecast will be clear with VFR conditions. fx && .PRELIMINARY POINT TEMPS/POPS... Spokane 56 84 58 83 55 84 / 0 0 0 10 10 10 Coeur d`Alene 55 84 57 80 53 84 / 0 0 0 10 10 10 Pullman 49 82 51 80 49 82 / 0 0 0 10 0 0 Lewiston 60 90 62 90 61 90 / 0 0 0 0 0 0 Colville 52 88 56 85 51 89 / 0 0 10 20 10 10 Sandpoint 49 84 52 80 49 84 / 0 0 10 20 20 10 Kellogg 53 84 53 79 51 81 / 10 0 0 10 10 10 Moses Lake 56 89 60 88 57 89 / 0 0 0 0 0 0 Wenatchee 61 88 63 88 62 91 / 0 0 0 0 0 0 Omak 60 89 59 86 55 90 / 0 0 10 10 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
615 PM CDT WED AUG 1 2012 .SHORT TERM...TONIGHT 615 PM CDT WED AUG 1 2012 WATCHING EVOLUTION OF THUNDERSTORMS ASSOCIATED WITH ELEVATED INSTABILITY AND SFC FRONT/ELEVATED FRONTOGENETIC FORCING ACROSS SOUTHWEST MN. THIS WEST-EAST RUNNING BOUNDARY WILL HOVER ACROSS SOUTHEAST MN-WESTERN WI OVERNIGHT...STAYING A FOCUS FOR SHOWER/STORM DEVELOPMENT. MAIN CONCERN THOUGH IS THE SEVERE POTENTIAL THIS EVENING. STRONG INSTABILITY WITH MLCAPES NEAR 4K J/KG OVER SOUTHERN MN PER RAP ANALYSIS AT 22Z. SHEAR ISN/T TOO IMPRESSIVE...BUT ABOUT 20-25 KTS EFFECTIVE SHEAR. THE INSTABILITY WOULD SUPPORT STRONG UPDRAFTS AND A LARGE HAIL THREAT. PERHAPS MORE SIGNIFICANTLY IS THE DEEP DRY SUB CLOUD LAYER. BUFKIT SOUNDINGS CONTINUE TO INDICATE THIS...WITH DCAPES OVER 1500 J/KG PROGGED FOR THE FORECAST AREA THIS EVENING. THIS ENHANCES THE DAMAGING WIND THREAT. ANY STRONG STORM WOULD BE CAPABLE OF PRODUCING 40 MPH GUSTS...OBVIOUSLY MORE WITH A SEVERE STORM. SEVERE THUNDERSTORM WATCH BUTTING UP AGAINST THE WESTERN FORECAST AREA...AND IF STORMS CONTINUE TO EVOLVE...WOULD EXPECT ANOTHER WATCH FOR SOUTHEAST MN INTO WESTERN WISCONSIN BY MID EVENING. .LONG TERM...SUNDAY THROUGH WEDNESDAY 309 PM CDT WED AUG 1 2012 MEDIUM RANGE MODEL RUNS OF 01.00Z IN RATHER GOOD AGREEMENT WITH THE TROUGH MOVING EAST OF THE REGION AND WEAK SHORTWAVE RIDGING BUILDING INTO THE UPPER MIDWEST. MODELS STAY IN PRETTY GOOD AGREEMENT MON-WED AS THE SHORTWAVE RIDGING QUICKLY MOVES EAST OF THE AREA MON AND THE NEXT AND THE NEXT STRONGER TROUGH MOVES ACROSS SOUTHERN CAN/NORTHERN CONUS...INTO THE UPPER MIDWEST TUE/WED. SOME DIFFERENCE OF TIMING/ STRENGTH DETAILS OF SHORTWAVES IN THE FLOW BY TUE/WED BUT THIS TO BE EXPECTED. BETWEEN MODEL CONSISTENCY GOOD BUT RUN-TO-RUN CONSISTENCY LESS THAN DESIRABLE...ESPECIALLY BY TUE/WED. LONG-TERM FCST CONFIDENCE GOOD SUN THEN AVERAGE MON-WED UNTIL THE DETAIL CONSENSUS IMPROVES. WITH THE TROUGH/LOW EXITING EAST...DRIER/COOLER CAN HIGH PRESSURE SETTLES ACROSS THE REGION FOR SUN/MON. TEMPS LOOKING TO BE BELOW NORMAL SUN...THEN ALREADY MODERATE ON MON AS THE CENTER OF THE HIGH MOVES EAST AND SOUTHERLY FLOW RETURNS. MID LEVEL TROUGH MOVING EAST ALONG THE US/CAN BORDER TUE/WED DRAGS A SFC TROUGH/FRONT INTO/ ACROSS THE AREA TUE. AGAIN TIMING/DETAIL DIFFERENCES ON MOISTURE/ INSTABILITY AND FORCING/LIFT BY TUE. BOUNDARY LOOKS TO STALL IN THE REGION WED WITH STRENGTHENING LOW PRESSURE IN THE CENTRAL/NORTHERN PLAINS AS MORE SHORTWAVE ENERGY COMES THRU THE ROCKIES OR DROPS INTO THE NORTHERN PLAINS. SMALL SHRA/TSRA CHANCES TUE/WED LOOK REASONABLE AT THIS POINT. WITH CONTINUED SOUTHERLY/INCREASING MOISTURE...TEMPS CLIMB BACK TO ABOVE NORMAL FOR TUE/WED. MODEL CONSENSUS DATA SET IN FCST GRIDS FOR DAYS 4-7 HAVE THIS WELL TRENDED. && .AVIATION... 615 PM CDT WED AUG 1 2012 SAGGING WEST-EAST RUNNING FRONTAL BOUNDARY WILL SERVE AS THE FOCUS FOR SHRA/TS DEVELOPMENT THIS EVENING...THROUGH THE OVERNIGHT HOURS. THE ACTIVITY WILL SPARK TO THE WEST...MIGRATING EASTWARD ALONG THE BOUNDARY AS THE NIGHT WEARS ON. TIMING ON ENCROACHMENT AT KRST/KLSE IS UNCERTAIN...AND MESO MODELS AREN/T ALL THAT ENLIGHTENING. HOWEVER...TRENDS DO FAVOR A BIT LATER THAN PREVIOUS FORECASTS...AND WILL ADJUST TAFS THIS WAY. DRY NEAR SFC/SUB CLOUD WILL ENHANCE DOWNDRAFTS WITH ANY STRONG STORM...AND GUSTS UPWARDS OF 40-50 KTS WOULD BE POSSIBLE. WITH THE FRONT HANGING AROUND OVERNIGHT...A PROLONGED PERIOD OF -SHRA LOOKS LIKELY. SEVERAL HOURS OF RAIN COULD ALSO RESULT IN THE LOWERING OF CLOUD BASES...BUT WILL STAY VFR FOR NOW. RAIN CHANCES WILL LINGER THROUGH PARTS OF THU MORNING...BUT SHOULD EXIT EAST BY THE AFTERNOON. SHOULD BREAK OUT OF BKN MID LEVEL CIGS BY MID/LATE AFTERNOON. FOR WINDS...ASIDE FROM THE ENHANCED GUST POTENTIAL THIS EVENING...DIRECTION COULD BE HIGHLY VARIABLE AND RELATIVELY LIGHT AS THE FRONT LAYS ACROSS KRST/KLSE. THIS MAKES PINNING DOWN A PREVAILING DIRECTION A BIT DIFFICULT UNTIL THE FRONT SAGS SOUTH. && .ARX WATCHES/WARNINGS/ADVISORIES... 309 PM CDT WED AUG 1 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RIECK LONG TERM....RRS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
344 AM CDT TUE JUL 31 2012 .SHORT TERM...TODAY THROUGH THURSDAY 343 AM CDT TUE JUL 31 2012 AT 3 AM...A COLD FRONT EXTENDED FROM ANN ARBOR MICHIGAN TO FREEPORT ILLINOIS TO SLATER IOWA. AN EXTENSIVE AREA OF SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FROM NORTHERN ILLINOIS EAST NORTHEAST INTO SOUTHERN LOWER MICHIGAN. THESE THUNDERSTORMS ARE EXCEEDING 50K FEET AND AS RESULT...WE CAN STILL SEE THE IN-CLOUD LIGHTNING FROM STORMS WHICH ARE AT LEAST 130 MILES FROM OUR OFFICE. IN THE WAKE OF THIS FRONT...A CANADIAN HIGH PRESSURE SYSTEM IS BUILDING INTO THE REGION. THIS HIGH WILL PROVIDE CLEAR SKIES ACROSS THE UPPER MISSISSIPPI RIVER VALLEY TODAY AND MUCH OF THE TONIGHT. BUFKIT SOUNDINGS SUGGEST THAT THE AREA WILL MIX UP TO 825 MB THIS AFTERNOON. THIS WILL ALLOW TEMPERATURES TO CLIMB INTO THE 78 TO 83 DEGREE RANGE IN MOST AREAS. THE DRY SAND IN THE RIVER VALLEYS WILL ALLOW THESE AREAS TO WARM UP EVEN MORE. TEMPERATURES IN THE MISSISSIPPI AND WISCONSIN RIVER VALLEYS WILL LIKELY CLIMB INTO THE UPPER 80S. WITH VERY DRY AIR ALOFT...DEW POINTS WILL LIKELY INTO THE 50S AND LOWER 60S THIS AFTERNOON. THIS IS SLIGHTLY LOWER THAN THE MOS GUIDANCE. FOR TONIGHT...THE MAIN QUESTION IS WHETHER VALLEY FOG WILL DEVELOP. WITH TEMPERATURES FALLING INTO THE 50S AND LOWER 60S AND RIVER TEMPERATURES AROUND 80...IT WOULD NORMALLY CONDUCIVE FOR THE DEVELOPMENT OF VALLEY FOG...BUT IN THIS SITUATION THERE IS CONCERN THAT THE DEW POINTS WILL NOT RECOVER FAST ENOUGH FOR THIS TO OCCUR. THE ONE EXCEPTION LOOKS TO BE IN THE WISCONSIN RIVER VALLEY WHERE THE STEEPER VALLEY MAY ENHANCE THE COLD AIR DRAINAGE LEADING TO THE GREATER POTENTIAL OF FOG DEVELOPMENT AFTER MIDNIGHT. ON WEDNESDAY AFTERNOON AND NIGHT...ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST INTO THE REGION. SOUNDINGS SHOW THAT THERE IS STRONG CAP FOR MUCH OF THE DAY AHEAD OF THIS FRONT AND THIS WILL ALLOW TEMPERATURES TO WARM INTO THE LOWER AND MID 90S. AS THE FRONT APPROACHES...THE CAP WILL SLOWLY ERODE. THERE IS PLENTY OF DRY AIR BELOW 10K FEET...SO ANY SHOWERS AND THUNDERSTORMS THAT DO DEVELOP WILL BE HIGH BASED. THE DRY AIR BELOW THE CLOUD BASE WILL ENHANCE THE POTENTIAL OF DAMAGING WINDS WITH ANY OF THE STORMS THAT DO HAPPEN DEVELOP. HOWEVER THE CONVERGENCE IS NOT THAT GREAT ALONG THIS FRONT...MOISTURE TRANSPORT IS WEAK...AND THE INSTABILITY IS NOT THAT IMPRESSIVE...SO THERE IS PLENTY OF QUESTION WHETHER ANY THUNDERSTORMS WILL EVEN DEVELOP. ON THURSDAY...THE MODELS CONTINUE TO SUGGEST THAT A WEAK FRONT WILL BE DRAPED ACROSS THE AREA. ML CAPES CLIMB TO AROUND 1000 J/KG. HOWEVER THE ML CINS ARE STILL AROUND 100 J/KG AND THE SURFACE AND ELEVATED CONVERGENCE ALONG THIS FRONT IS VERY WEAK. AS A RESULT... NOT TOO EXCITED ABOUT THE THE SHOWER AND THUNDERSTORM PROBABILITIES...SO LEFT THEM AROUND 20 PERCENT. .LONG TERM...THURSDAY NIGHT THROUGH MONDAY 343 AM CDT TUE JUL 31 2012 ON FRIDAY AND FRIDAY NIGHT...SOUTHERLY WINDS AHEAD OF A STRONG SHORT WAVE TROUGH WILL BRING VERY WARM AIR INTO THE REGION. THE ALL BLEND TEMPERATURES LOOK TOO LOW CONSIDERING THE WARM AIR MOVING IN ALOFT. AS A RESULT...TRENDED THEM UPWARD BY MIXING IT WITH THE ECMWF WHICH IS MUCH WARMER AND PROBABLY MORE REALISTIC. ON SATURDAY AND SATURDAY NIGHT...A DYNAMIC SYSTEM WILL BE MOVING THROUGH THE REGION. BY FAR...THE GEM IS MORE DYNAMIC /NEGATIVELY TILTED/ THAN EITHER THE ECMWF AND GFS. THIS SYSTEM HAS THE POTENTIAL OF PRODUCING SEVERE WEATHER...BUT THE TIMING OF THE WAVE DOES NOT LOOK THAT GOOD FOR OUR AREA. && .AVIATION...THROUGH 06Z WEDNESDAY 1149 PM CDT MON JUL 30 2012 HIGH PRESSURE WILL DOMINATE THE PATTERN THROUGH THE TAF PERIOD. CLEAR SKIES ARE EXPECTED WITH WINDS LESS THAN 10 KNOTS. BOTH THE 31.02Z RAP AND 31.00Z NAM SHOWS WINDS ABOVE 10 KNOTS JUST ABOVE THE SURFACE OVERNIGHT TONIGHT AND THIS SHOULD PRECLUDE ANY FOG FORMATION. && .ARX WATCHES/WARNINGS/ADVISORIES... 251 AM CDT TUE JUL 31 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT MON JUL 30 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY 247 PM CDT MON JUL 30 2012 MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES THIS EVENING. FOCUS THEN TURNS TO VALLEY FOG POTENTIAL TONIGHT AND AGAIN WEDNESDAY NIGHT AND SHOWER/THUNDERSTORM CHANCES WEDNESDAY NIGHT INTO THURSDAY. LATEST SURFACE OBSERVATIONS SHOWED A COLD FRONT EXTENDING FROM IRONWOOD MICHIGAN...TO NEAR RICE LAKE WISCONSIN...TO NEAR ST. JAMES MINNESOTA...DRIFTING SOUTHEAST. MESOSCALE FORECAST MODELS CONTINUE TO SUGGEST THAT SHOWERS AND THUNDERSTORMS WILL FIRE ALONG THIS FRONT IN THE 4 TO 6 PM TIME FRAME. THIS WOULD PUT THE FRONT OVER CENTRAL WISCONSIN...EXTENDING SOUTHWEST INTO NORTHEAST IOWA. LATEST VISIBLE SATELLITE IMAGERY SHOWED A WELL DEFINED CUMULUS FIELD AHEAD OF THE FRONT. NO PRECIPITATION RETURNS ON RADAR YET ALONG THIS FIELD. THINKING THE FRONT WILL FINALLY GENERATE CONVECTION AS IT MOVES INTO CENTRAL AND FAR SOUTHWEST WISCONSIN...EXTENDING INTO NORTHEAST IOWA. DRY LOW LEVELS WILL LEAD TO THE POTENTIAL FOR DAMAGING WINDS WITH ANY STORMS THAT DEVELOP. LATEST RAP ANALYSIS INDICATES NEARLY 1400-1600 DOWNDRAFT CAPE AHEAD OF THE COLD FRONT. 0-6 KM SHEAR IS RATHER WEAK...GENERALLY LESS THAN 30 KTS...SO STORMS MAY STRUGGLE TO BECOME ORGANIZED ONCE THEY DEVELOP. SURFACE BASED CAPE VALUES OF NEARLY 4000 J/KG WILL LEAD TO STRONG UPDRAFTS...WITH MARGINALLY SEVERE HAIL POSSIBLE. THE COLD FRONT WILL PUSH EAST OF THE FORECAST AREA LATE THIS EVENING WITH HIGH PRESSURE BUILDING INTO THE REGION. FORECAST SOUNDINGS ARE SHOWING THE POTENTIAL FOR SOME VALLEY FOG DEVELOPMENT ALONG THE MISSISSIPPI RIVER. THE AIR MASS LOOKS A BIT ON THE DRY SIDE FOR THIS TO OCCUR. TEMPERATURE AND DEW POINT SPREADS AT KLSE APPROACH TWO DEGREES BUT THIS OCCURS LATE IN THE NIGHT/EARLY MORNING...AROUND 11Z. WINDS ARE MORE FAVORABLE...WITH LIGHT WIND FROM THE SURFACE THROUGH 2 KFT. THINKING A BRIEF PERIOD OF PATCHY VALLEY FOG IS POSSIBLE TONIGHT...ESPECIALLY IF ANY PRECIPITATION FALLS THIS EVENING. ANOTHER FACTOR POSSIBLY WORKING AGAINST VALLEY FOG IS A LOW CLOUD DECK APPROACHING THE FORECAST AREA BEHIND THE COLD FRONT. THESE CLOUDS LOOK TO PASS JUST EAST OF THE MISSISSIPPI SO WILL HAVE TO KEEP A CLOSE WATCH ON THESE. OTHERWISE...PLAN ON SKIES RANGING FROM MOSTLY CLEAR TO PARTLY CLOUD DURING THE OVERNIGHT HORUS. LOOK FOR LOW TEMPERATURES WILL RANG FROM LOWER 60S ACROSS NORTHERN WISCONSIN TO THE UPPER 60 OVER NORTHEAST IOWA. SLIGHTLY COOLER AIR WILL MOVE INTO THE REGION BEHIND THE FRONT LATE TONIGHT INTO TUESDAY. 850 MB TEMPERATURES WILL FALL FROM 22C MONDAY AFTERNOON INTO THE 14 TO 16 C RANGE BY EARLY TUESDAY MORNING. HIGH PRESSURE WILL BE IN CONTROL THROUGH THE DAY ON TUESDAY PROVIDING MOSTLY SUNNY SKIES. PLAN ON HIGHS RANGING FROM THE LOWER 80S ACROSS NORTHERN WISCONSIN TO THE UPPER 80S OVER NORTHEAST IOWA. HIGH PRESSURE IS EXPECTED TO SLIDE EAST OF THE FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY MORNING AS ANOTHER COLD FRONT APPROACHES FROM WESTERN MINNESOTA AND EAST SOUTH DAKOTA. FORECAST SOUNDINGS AGAIN SHOW THE POTENTIAL FOR SOME VALLEY FOG. HIGH PRESSURE WILL BE SETTLED OVER THE AREA DURING THE OVERNIGHT HOURS PROVIDING LIGHT AND VARIABLE WINDS. TEMPERATURE/DEW POINT SPREADS APPROACH TWO DEGREES BY 09Z. WILL HAVE TO KEEP A CLOSE WATCH ON SOME HIGH CLOUDS TRYING TO STREAM IN FROM THE WEST. CURRENT THINKING IS THAT AREAS OF FOG WILL DEVELOP ALONG THE MISSISSIPPI AND WISCONSIN RIVER VALLEY. FORECAST MODELS ARE SHOWING VERY DRY AIR ADVECTING INTO THE AREA AHEAD OF THE APPROACHING FRONT. WINDS WILL SHIFT TO THE SOUTHWEST BY WEDNESDAY AFTERNOON AS THE FRONT APPROACHES. DEW POINTS PLUMMET AS THIS OCCURS...ESPECIALLY ACROSS NORTHEAST IOWA...PORTIONS OF SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN. COULD SEE DEW POINTS FALL INTO THE MID 40S BY THE MID AFTERNOON HOURS. THE COLD FRONT IS EXPECTED TO MOVE INTO THE AREA LATE WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AS A SHORTWAVE TROUGH MOVES OVER THE UPPER MISSISSIPPI RIVER VALLEY. THE FRONT AND SHORTWAVE WILL NOT HAVE MUCH MOISTURE TO WORK WITH AS THE DRY AIR ADVECTS IN FROM THE SOUTHWEST...WITH A FAIRLY DEEP ELEVATED MIXED LAYER IN PLACE. EXPECT TO SEE SOME SHOWERS AND ISOLATED THUNDERSTORMS AS THIS FEATURE MOVES THROUGH. RATHER HIGH BASED ACTIVITY WITH CLOUD BASES IN THE 8 TO 10KFT RANGE. GUSTY WINDS WOULD BE A CONCERN WITH ANY SHOWER/STORM ACTIVITY THAT DEVELOPS. ANOTHER SHORTWAVE IS EXPECTED TO MOVE OVER THE REGION DURING THE DAY ON THURSDAY. AGAIN THE ELEVATED MIXED LAYER AND CAPPING WILL BE A FACTOR. 0-3KM MUCAPE WILL CLIMB TO AROUND 2000 J/KG THURSDAY AFTERNOON BUT QUICKLY WANES DURING THE AFTERNOON AS WEAK SURFACE HIGH PRESSURE ATTEMPTS TO BUILD IN FROM THE EAST. WILL MAINTAIN A CHANCE OF SHOWERS AND THUNDERSTORMS ON THURSDAY GIVEN THE SHORTWAVE MOVING THROUGH. .LONG TERM...FRIDAY THROUGH MONDAY 247 PM CDT MON JUL 30 2012 30.12 MEDIUM RANGE MODELS IN AGREEMENT FRIDAY INTO SATURDAY...SHOWING A POTENT UPPER LEVEL TROUGH MOVING ACROSS THE DAKOTAS AND PUSHING INTO THE UPPER MISSISSIPPI RIVER VALLEY. THE TROUGH IS EXPECTED TO CLOSE INTO AN UPPER LOW OVER EASTERN NORTH DAKOTA/NORTHERN MINNESOTA DURING THE DAY ON SATURDAY...PUSHING A COLD FRONT ACROSS THE AREA. GIVEN THE STRONG DYNAMICS OF THIS SYSTEM AND STRONG MOISTURE RETURN AHEAD OF IT...FOCUSED INTO THE FORECAST AREA...A SEVERE WEATHER EVENT LOOKS POSSIBLE. TIMING OF THE FRONT AND ANY MCS ACTIVITY AHEAD OF IT WILL HAVE AN IMPACT ON CONVECTION OVER THE FORECAST AREA. EXACT DETAILS ARE UNCLEAR AT THIS TIME BUT WILL HAVE TO KEEP A VERY CLOSE WATCH ON THE NEXT FEW FORECAST MODEL RUNS. CURRENT THINKING IS THAT THE AREA COULD SEE AN MCS MOVE THROUGH SATURDAY MORNING...WITH STORMS REDEVELOPING ALONG THE COLD FRONT SATURDAY AFTERNOON. PLAN ON HIGHS ON FRIDAY RANGING FORM THE LOWER 80S OVER NORTHERN WISCONSIN TO THE MID 80S ACROSS NORTHEAST IOWA. LOOK FOR OVERNIGHT LOWS IN THE 60S. SLIGHTLY COOLER AIR WILL MOVE IN BEHIND THE FRONT ON SUNDAY WITH HIGHS FALLING INTO THE 70S TO LOWER 80S. && .AVIATION...THROUGH 06Z WEDNESDAY 1149 PM CDT MON JUL 30 2012 HIGH PRESSURE WILL DOMINATE THE PATTERN THROUGH THE TAF PERIOD. CLEAR SKIES ARE EXPECTED WITH WINDS LESS THAN 10 KNOTS. BOTH THE 31.02Z RAP AND 31.00Z NAM SHOWS WINDS ABOVE 10 KNOTS JUST ABOVE THE SURFACE OVERNIGHT TONIGHT AND THIS SHOULD PRECLUDE ANY FOG FORMATION. && .ARX WATCHES/WARNINGS/ADVISORIES... 247 PM CDT MON JUL 30 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...RABERDING
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
545 AM EDT THU AUG 2 2012 .SYNOPSIS... A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY AND SUNDAY INCREASING THE CHANCES FOR RAINFALL. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .THIS MORNING...A SMALL AREA OF SHOWERS AND THUNDERSTORMS WERE AFFECTING THE CSRA. INCLUDED A 30-40 PERCENT CHANCE FOR 3-4 HOURS` THIS MORNING. THIS ACTIVITY IS ASSOCIATED WITH A WEAK SHORT WAVE WHICH ACCORDING TO THE RUC13 MODEL SHOULD HAVE MOVED TO THE EAST BY 13Z. ELSEWHERE LESS THAN 10 PERCENT. WILL CONTINUE TO MENTION PATCHY FOG SOUTHEAST PART OF CWA WHERE SURFACE DEWPOINTS ARE A BIT HIGHER. .TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44 PERCENT. SO WENT 20 PERCENT. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20 PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S. FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE 90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY. THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S. OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... MOSTLY CLEAR SKIES AND LIGHT WINDS AT THE MOMENT. TEMPS AND VSBYS HAVE BEEN SLOW TO FALL SO FAR THIS MORNING. LOW LEVELS NOT AS MOIST AS 24 HOURS AGO...AS DRIER AIR WORKED IN WEDNESDAY. GFS LAMP GUIDANCE HAS BEEN PERFORMING WELL RECENTLY...AND MOST RECENT RUN SUGGESTS NO SIGNIFICANT RESTRICTIONS AT MOST TERMINALS...WITH IFR AT OGB. STRONG UPPER SHORT WAVE IS COMING THROUGH THIS MORNING AND WILL PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION POSSIBLE EARLY THIS MORNING. LATEST RADAR INDICATES A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OVER EAST CENTRAL GA MOVING SE TOWARDS THE CSRA. WILL MONITOR FOR POSSIBLE INCLUSION IN THE DNL/AGS TAFS. IT APPEARS THAT MOST CONVECTIVE COVERAGE THIS AFTERNOON WILL BE CONFINED TO THE SE FA AND COASTAL PLAIN. CONFIDENCE/COVERAGE OF TS NOT SUFFICIENT TO INCLUDE IN THE TAFS AT THIS TIME. CONVECTIVE ANALYSIS INDICATES STRONG INSTABILITIES FOR THIS AFTERNOON...SO ANYTHING THAT DOES DEVELOP THIS AFTN/EVE WILL HAVE THE POTENTIAL TO BE STRONG TO SEVERE. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
445 AM EDT THU AUG 2 2012 .SYNOPSIS... A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY AND SUNDAY INCREASING THE CHANCES FOR RAINFALL. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .THIS MORNING...SOME WEAKENING SHOWERS AND THUNDERSTORMS MAY AFFECT THE EXTREME NORTHEAST PORTION...LANCASTER AND CHESTERFIELD COUNTIES EARLY BEFORE SUNRISE. THIS ACTIVITY IS ASSOCIATED WITH A WEAK SHORT WAVE WHICH ACCORDING TO THE RUC13 MODEL SHOULD HAVE MOVED TO THE EAST BY 12Z. WILL RUN A 20 PERCENT IN MENTIONED COUNTIES UNTIL 10Z...THEN LESS THAN 10 PERCENT. WILL CONTINUE TO MENTION PATCHY FOG SOUTHEAST PART OF CWA WHERE SURFACE DEWPOINTS ARE A BIT HIGHER. .TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44 PERCENT. SO WENT 20 PERCENT. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20 PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S. FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE 90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY. THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S. OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... MOSTLY CLEAR SKIES AND LIGHT WINDS AT THE MOMENT. TEMPS AND VSBYS HAVE BEEN SLOW TO FALL SO FAR THIS MORNING. LOW LEVELS NOT AS MOIST AS 24 HOURS AGO...AS DRIER AIR WORKED IN WEDNESDAY. GFS LAMP GUIDANCE HAS BEEN PERFORMING WELL RECENTLY...AND MOST RECENT RUN SUGGESTS NO SIGNIFICANT RESTRICTIONS AT MOST TERMINALS...WITH IFR AT OGB. STRONG UPPER SHORT WAVE IS COMING THROUGH THIS MORNING AND WILL PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION POSSIBLE EARLY THIS MORNING. LATEST RADAR INDICATES A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OVER EAST CENTRAL GA MOVING SE TOWARDS THE CSRA. WILL MONITOR FOR POSSIBLE INCLUSION IN THE DNL/AGS TAFS. IT APPEARS THAT MOST CONVECTIVE COVERAGE THIS AFTERNOON WILL BE CONFINED TO THE SE FA AND COASTAL PLAIN. CONFIDENCE/COVERAGE OF TS NOT SUFFICIENT TO INCLUDE IN THE TAFS AT THIS TIME. CONVECTIVE ANALYSIS INDICATES STRONG INSTABILITIES FOR THIS AFTERNOON...SO ANYTHING THAT DOES DEVELOP THIS AFTN/EVE WILL HAVE THE POTENTIAL TO BE STRONG TO SEVERE. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
323 AM EDT THU AUG 2 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THE WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THROUGH SUNRISE...EARLY MORNING SURFACE ANALYSIS SHOWED A WEAK SURFACE TROUGH EXTENDING ACROSS CENTRAL GEORGIA INTO THE NORTHERN MIDLANDS. THE LATEST RUNS OF THE RAP AND NSSL WRF MODELS SHOW ISOLATED CONVECTION FIRING ALONG THE TROUGH OVER THE NEXT FEW HOURS AS SHORTWAVE ENERGY MOVING THROUGH EASTERN KENTUCKY MOVES CLOSER. ALREADY SEEING A FEW CLUSTERS OF TSTMS FIRING ACROSS THE NORTH CAROLINA FOOTHILLS...SO IT IS CERTAINLY CONCEIVABLE THAT A TSTMS OR TWO COULD POP ACROSS THE MIDLANDS AND DRIFT INTO THE WESTERN ZONES PRIOR TO SUNRISE. ATTM IT APPEARS THE CHANCES FOR MEASURABLE RAINFALL WILL REMAIN LESS THAN 20 PERCENT SO WILL KEEP MENTIONABLE POPS OUT OF FORECAST FOR NOW AND MONITOR TRENDS CAREFULLY. MORNING LOWS FROM THE LOWER 70S WELL INLAND TO AROUND 80 AT THE BEACHES LOOK ON TRACK. TODAY...THE EVOLUTION OF AFTERNOON CONVECTION WILL MIRROR A TYPICAL MID-LATE SUMMER CONVECTIVE PATTERN TODAY WHERE OUTFLOW BOUNDARIES GENERATED BY ISOLATED SEA BREEZE TSTMS EVENTUALLY INTERSECT OUTFLOWS GENERATED BY UPSTREAM CONVECTION TO SPARK SCATTERED CONVECTIVE CLUSTERS ACROSS INLAND AREAS. THE NAM/S SOLUTION SHOWING SOME SHORT OF MESOSCALE CONVECTIVE SYSTEM /MCS/ PLOWING THROUGH SOUTHEAST GEORGIA LOOKS SOMEWHAT SPURIOUS AND IS NOT SUPPORTED BY ANY OF THE OTHER VARIOUS MESOSCALE OR GLOBAL MODELS ATTM. WILL MAINTAIN A 20-30 PERCENT POPS REGIME WITH THE HIGHEST GRIDDED POPS CENTERED ROUGHLY ALONG AND WEST OF THE I-95 CORRIDOR. HIGHER SHORT-TERM POPS MAY EVENTUALLY BE NEEDED LATER TODAY...ESPECIALLY IF MESOSCALE PROCESSES TAKE HOLD...BUT THIS IS NEARLY IMPOSSIBLE TO PIN DOWN THIS FAR OUT. HIGHS WILL RANGE FROM THE MID 90S INLAND TO THE MID 80S AT THE BEACHES. MODIFIED RAP BUFR SOUNDINGS SHOW DCAPES RISING TO NEAR 1300 J/KG BY EARLY AFTERNOON WITH TOTAL TOTALS NEARING 55 UNITS AND SHOWALTER INDICES DROPPING TO NEAR -3C. THIS COUPLED WITH DELTA EPT/S APPROACHING +30C SUGGEST THERE WILL BE A SLIGHTLY HIGHER RISK FOR DAMAGING WINDS WITH THE STRONGER TSTMS TODAY. THE RISK FOR PULSE SEVERE TSTMS WILL BE HIGHEST NEAR MESOSCALE BOUNDARY INTERACTIONS WITHIN A WEAK 0-6KM BULK SHEAR REGIME. A MENTION FOR ISOLATED SEVERE TSTMS WILL BE PLACED IN THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... ANY LINGERING CONVECTION WILL DIMINISH BY MID-EVENING AS INSOLATION WANES AND THE SEA BREEZE CLEARS THE WESTERN ZONES. EXPECT A DRY NIGHT TO PREVAIL...ALTHOUGH AN ISOLATED SHOWER/TSTM COULD POPS JUST ABOUT ANYWHERE WITH RESIDUAL OUTFLOWS LIKELY LURKING ABOUT. DEBRIS CLOUDINESS WILL THIN WITH MOSTLY CLEAR SKIES DOMINATING FOR MUCH OF THE OVERNIGHT PERIOD. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO AROUND 80 AT THE BEACHES. THE FORECAST AREA WILL BECOME POSITIONED BETWEEN A SURFACE HIGH PRESSURE TO THE WEST AND A SUBTROPICAL HIGH PRESSURE TO THE EAST. HEIGHTS WILL CONTINUE TO INCREASE THROUGH THE WEEKEND WITH MODEST UPPER LEVEL RIDGING BUILDING ALONG THE EAST COAST. A PERSISTENT SOUTHERLY FLOW WILL ALLOW PLENTY OF DEEP MOISTURE TO CONTINUOUSLY ADVECT OVER THE AREA. MODEL SOUNDINGS VERIFY THIS DEEP MOISTURE WITH PWATS REMAINING STEADY AROUND 2 INCHES THROUGH THE WEEKEND. THUS...EXPECT ISOLATED TO SCATTERED CONVECTION TO DEVELOP FAIRLY EASILY EACH AFTERNOON AS THE SEA BREEZE PROPAGATES INLAND AND CONVECTIVE TEMPERATURES ARE REACHED. WITH HIGH TEMPERATURES EXPECTED TO REACH THE LOW TO MID 90S EACH AFTERNOON...CONVECTIVE TEMPS IN THE UPPER 80S WILL NOT BE DIFFICULT TO EXCEED. STILL...INSTABILITY PARAMETERS ARE LESS THAN IMPRESSIVE WITH SHOWALTER INDICES GENERALLY POSITIVE AND LAPSE RATES BETWEEN 5 AND 6 C/KM. THEREFORE...THE SEVERE POTENTIAL APPEARS LOW...BUT CAN NOT RULE OUT ONE OR TWO ISOLATED STRONG TO SEVERE STORMS. ANY STRONG STORMS WILL LIKELY DEMONSTRATE TRADITIONAL SUMMERTIME PULSE CHARACTERISTICS. ANY LINGERING CONVECTION WILL QUICKLY DIMINISH AFTER SUNSET...WITH OVERNIGHT LOWS EXPECTED TO REMAIN QUITE MILD IN THE MID TO LOW 70S INLAND AND UPPER 70S ALONG THE BEACHES. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... MODELS SHOW SUBTLE HIGH FALLS AT THE BEGINNING OF THE PERIOD AS A LOW PRESSURE SYSTEM MOVES EASTWARD ACROSS THE NEW ENGLAND AREA. ITS ASSOCIATED COLD FRONT WILL LIKELY STALL OUT WELL NORTH OF THE AREA SOMETIME AROUND MID WEEK. MEANWHILE...THE UPPER RIDGE ACROSS CENTRAL UNITED STATES WILL CONTINUE TO STRENGTHEN THROUGH THE PERIOD. AT THE SURFACE...THE FORECAST AREA WILL REMAIN SANDWICHED BETWEEN THE SURFACE HIGH PRESSURE OVER THE MIDDLE OF THE UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. THIS PATTERN COULD ALLOW FOR AN INCREASE IN CONVECTION...ESPECIALLY AS CONVECTION DEVELOPS ALONG THE STALLED FRONT AND INTERACTS WITH OTHER BOUNDARIES...LIKE THE SEA BREEZE. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS WITH LOW TO MID 90S EXPECTED DURING THE AFTERNOON AND DIPPING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. COULD SEE SOME GROUND FOG DEVELOP AT EITHER KCHS/KSAV GIVEN MOIST LOW-LEVEL PROFILES UNDER A LIGHT WIND REGIME. ANY REDUCTIONS WILL GENERALLY BE CONFINED TO AN HOUR OR TWO PRIOR TO SUNRISE. LOW PROBABILITIES FOR TSTMS THIS AFTERNOON AT BOTH TERMINALS. CHANCES TO LOW TO JUSTIFY ANY MENTION THIS FAR OUT. EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS POSSIBLE THURSDAY AFTERNOON/EVENING WITH SHOWERS/THUNDERSTORMS. && .MARINE... A BROAD SOUTHERLY FLOW REGIME WILL REMAIN IN TACT ACROSS THE WATERS THROUGH TONIGHT. WINDS WILL REMAIN 10-15 KT WITH SEAS 2-4 FT. ATLANTIC HIGH PRESSURE WILL PREVAIL ACROSS THE MARINE AREA THROUGH EARLY NEXT WEEK. THIS PATTERN WILL CONTINUE TO RESULT IN CONDITIONS BELOW SMALL CRAFT CRITERIA. IN GENERAL...SOUTH/SOUTHWEST WINDS BETWEEN 10 TO 15 KNOTS WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE WITH BRIEF INCREASES OF 15 TO 20 KNOTS...MAINLY DURING NOCTURNAL SURGING. SEAS WILL ALSO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH THE PERIOD...BUT EXPECT BRIEF INCREASES DURING TIMES OF STRONGER WINDS. GENERALLY...SEAS WILL REMAIN 2 TO 3 FEET WITHIN 20 NM AND NO MORE THAN 5 FEET FURTHER OUT. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
204 AM EDT THU AUG 2 2012 .PREV DISCUSSION... UPDATE... /ISSUED 956 PM EDT WED AUG 1 2012/ ISOLATED STRONG TO SEVERE STORM POTENTIAL CONTINUES ACROSS THE NORTHERN TIER OF THE FORECAST AREA EARLY TONIGHT. SPC ALSO UPDATED TO INCLUDE PART OF THIS AREA IN A SLIGHT RISK...HOWEVER THE MAJORITY OF THE MORE INTENSE DEVELOPMENT HAS PASSED. SEVERAL CLUSTERS OF CONVECTION NEAR A SFC BOUNDARY HAVE BEEN TRACKING SEWD FROM SOUTHERN TN AND THE HRRR HAS THIS DEVELOPMENT PERSISTING FARTHER SOUTH UNTIL JUST NORTH OF ATLANTA BY NEAR 06Z. PER OBSERVED DEWPOINT DEPRESSIONS AHEAD OF THE STORMS AND RECENT SOUNDING DATA...THE LOW LEVELS ARE QUITE DRY AND STORM DEVELOPMENT IS LIKELY ELEVATED. LARGE HAIL AND DAMAGING WINDS HAVE BEEN THE MAIN CONCERNS...HOWEVER SOME CELLS HAVE SHOWN ROTATION ALBEIT ONLY OBSERVABLE ABOUT 6KFT AGL. ADJUSTED POPS TO LIKELY AND CHANCE IN THE NORTH BEFORE MIDNIGHT AND THEN SLIGHT TO NO CHANCE THE REST OF THE OVERNIGHT. MADE OTHER ADJUSTMENTS TO TEMP AND DEWPOINT TRENDS...BUT DID NOT AFFECT OVERNIGHT MINS. PREVIOUS DISCUSSION FOLLOWS... 03 PREV DISCUSSION... SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... /ISSUED 252 PM EDT WED AUG 1 2012/ CURRENT SATELLITE LOOP SHOW MOSTLY CLEAR SKIES OVER THE AREA. THERE IS SOME CU BEGINNING TO DEVELOP ACROSS WEST AND CENTRAL GA SO THIS LOOKS LIKE IT COULD BE THE BEGINNING OF SOME ISOLATED SHRA/TSRA THIS AFTERNOON/EVENING. THERE IS A WEAK STATIONARY BOUNDARY OVER N GA THAT MAY ACT AS A FOCUSING MECHANISM FOR THUNDERSTORM DEVELOPMENT. THE KEY IS GOING TO BE JUST HOW MUCH DRIER AIR HAS FILTER INTO THE AREA UNDER THE WEAK RIDGE BUILDING IN FROM THE NORTH AND HOW STRONG IS THE INSTABILITY ACROSS THE AREA. LOOKS LIKE WE WILL SEE SOME ISOLATED TO SCATTERED SHRA/TSRA DEVELOP ACROSS NORTH GA BUT IT SHOULD DISSIPATE OUT SHORTLY AFTER SUNSET. MOISTURE INCREASES SOME THURSDAY FROM THE NORTH AS THE RIDGE BREAKS DOWN A BIT MORE THROUGH THE END OF THE WEEK. TEMPS WILL STAY NEAR SEASONAL NORMS THROUGH THE SHORT TERM. 01 LONG TERM /FRIDAY THROUGH WEDNESDAY/... /ISSUED 252 PM EDT WED AUG 1 2012/ UPPER LEVEL HIGH PRESSURE RIDGE REMAINS SITUATED OVER TEXAS INTO THE EXTENDED PERIOD...WITH NORTHWEST FLOW PREVAILING ACROSS THE TENNESSEE VALLEY AND INTO GEORGIA. THIS FLOW WILL CONTINUE TO USHER UPPER LEVEL DISTURBANCES INTO THE REGION INTO THE WEEKEND. THESE FEATURES...COMBINED WITH AMPLE DAYTIME HEATING WILL KEEP SLIGHT CHANCE TO CHANCE THUNDERSTORMS ACROSS THE AREA. INTO EARLY NEXT WEEK...HIGH PRESSURE RIDGE OVER THE ATLANTIC BECOMES MORE DOMINANT ACROSS THE SOUTHEAST AS LOW PRESSURE DEEPENS OVER SOUTH CENTRAL CANADA. THIS LOW WILL DRAG A FRONTAL BOUNDARY THROUGH THE TENNESSEE VALLEY BY MONDAY MORNING...AND PUSH INTO NORTHWEST GEORGIA BY MONDAY AFTERNOON. TIMING OF THIS SYSTEM AS IT PUSHES THROUGH DIFFERS SLIGHTLY BY MODEL...SO HAVE MADE NO MAJOR ADJUSTMENTS TO THE CURRENT FORECAST BASED ON THE UNCERTAINTY. HIGH PRESSURE BUILDS BACK INTO THE REGION BEHIND THE FRONT...AND ANTICIPATE DIURNALLY DRIVEN CONVECTION TO RETURN BY MID WEEK. PREVIOUS FORECAST CONTINUES TO APPEAR ON TRACK...AND HAVE ADDED THE PREVIOUS DISCUSSION BELOW... 31 /ISSUED 438 AM EDT WED AUG 1 2012/ LITTLE CHANGE IN THE PATTERN...HENCE THE SCATTERED AFTERNOON AND EVENING THUNDERSTORMS TO CONTINUE. UPPER LEVEL LOW REMAINS OVER TEXAS AS STORM SYSTEM RIDE OVER THE TOP THROUGH THE PLAINS AND OHIO VALLEY. THE HIGH OFF THE COAST CONTINUES TO HOLD A WARM MOIST AIR MASS OVER THE SOUTHEAST... THOUGH THE GFS MAINTAINS A HIGHER MEAN RH OVER THE AREA THAN DOES THE ECMWF. THE GFS SOLUTION PREFERRED. SUNDAY NIGHT INTO MONDAY THEY BOTH HAVE A COLD FRONT MOVING THROUGH EASTERN TENNESSEE AND INTO NORTHERN GEORGIA MONDAY MORNING. IT SETTLES INTO CENTRAL/SOUTH GEORGIA AND WEAKENS BY TUESDAY...BUT PLENTY OF MOISTURE REMAINS OVER THE AREA TO CONTINUE THE AFTERNOON AND EVENING THUNDERSTORMS. LIKEWISE...SEE NO CHANGE IN THE TEMPERATURES THROUGH THE PERIOD. 37 && .AVIATION... 06Z UPDATE... VFR THROUGH THE PERIOD...EXCEPT FOR MVFR MORNING HAZE/FOG POSSIBLE AT SOME SITES. SOUTHWESTERLY WINDS STRUGGLING TO REACH 10 KTS...WITH LIGHT VARIABILITY AT NIGHT FOR MOST SITES. CONVECTION MENTIONABLE IN THE AFTERNOON AT ALL SITES. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE FOR CONVECTION THURSDAY... HIGH CONFIDENCE ON ALL OTHER ELEMENTS. PREFERRED GFS SLIGHTLY OVER THE NAM. RAG && .PRELIMINARY POINT TEMPS/POPS... ATHENS 94 73 94 71 / 40 20 20 30 ATLANTA 95 75 91 73 / 30 20 30 30 BLAIRSVILLE 88 67 85 67 / 20 20 30 50 CARTERSVILLE 96 72 92 70 / 30 20 30 40 COLUMBUS 97 76 93 73 / 30 20 20 20 GAINESVILLE 93 75 92 71 / 40 20 30 40 MACON 97 73 93 71 / 30 20 20 20 ROME 96 72 94 71 / 20 20 40 40 PEACHTREE CITY 94 71 90 69 / 30 20 20 20 VIDALIA 97 76 95 73 / 30 20 20 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RAG LONG TERM....37 AVIATION...RAG
AREA FORECAST DISCUSSION
NWS TOPEKA KS
343 AM CDT THU AUG 2 2012 .DISCUSSION... ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH. THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY. NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT AN ADVISORY. FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST. MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY. FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS. WOLTERS && .AVIATION... MAIN CONCERN FOR THE TAFS WILL BE THE TIMING AND AREAL COVERAGE OF CONVECTION AS IT MOVES ACROSS NORTHEAST KANSAS. CIGS EXPECTED TO BE VFR THROUGH THE PERIOD BUT MVFR VSBYS ARE POSSIBLE WITH TSRA. CONVECTION SHOULD MOVE EAST OF THE TERMINALS BY 16Z. HAVE MAINTAINED A MENTION OF VCTS ATTM. 53 && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
333 AM CDT THU AUG 2 2012 .DISCUSSION... TODAY-TONIGHT: ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400. CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH IT. FRI-FRI NIGHT: HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW... COULD BE EVEN WARMER THAN FORECAST. SAT-SUN: GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD. LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT... WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN SECTIONS. MON-WED: CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH. INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED. WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD. -HOWERTON && .AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 107 78 104 78 / 20 20 10 10 HUTCHINSON 104 76 103 76 / 20 20 10 10 NEWTON 103 77 102 77 / 20 20 10 10 ELDORADO 104 77 104 77 / 20 20 10 10 WINFIELD-KWLD 111 80 106 80 / 20 20 10 10 RUSSELL 99 73 101 73 / 20 30 10 20 GREAT BEND 101 74 102 74 / 20 20 10 20 SALINA 99 76 102 75 / 20 30 10 20 MCPHERSON 102 75 103 75 / 20 30 10 20 COFFEYVILLE 110 79 106 79 / 20 20 10 10 CHANUTE 105 76 103 78 / 20 20 10 10 IOLA 103 77 102 77 / 20 20 10 10 PARSONS-KPPF 107 77 104 79 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING FOR KSZ069-082-083-091>094-098>100. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1155 PM MDT WED AUG 1 2012 .UPDATE... ISSUED AT 808 PM MDT WED AUG 1 2012 MODIFIED THE EVENING AND OVERNIGHT FORECAST SLIGHTLY MAINLY TO ACCOUNT FOR CURRENT CLOUD COVER AND PRECIPITATION COVERAGE AND TO BLEND INTO OVERNIGHT TRENDS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 225 PM MDT WED AUG 1 2012 THROUGH TONIGHT...CONVECTION IS ONCE AGAIN EXPECTED TO DEVELOP ACROSS THE PALMER DIVIDE REGION OF COLORADO WITH A GRADUAL SHIFT EASTWARD WITH TIME. HRRR IS ALSO DEVELOPING CONVECTION ACROSS NORTHWEST KANSAS BUT GIVEN LACK OF CU DEVELOPMENT OVER THIS AREA...CONFIDENCE IS BELOW AVERAGE IN THIS SOLUTION. HAVING SAID THAT...WILL MAINTAIN SLIGHT CHANCE POPS TO COVER THIS POTENTIAL. DID BUMP POPS UP SLIGHTLY FOR THE LATE EVENING TIME FRAME WHEN CONFIDENCE IS HIGHEST. TRENDED OVERNIGHT LOWS UP OVER THE EAST SIMILAR TO WHAT WAS OBSERVED THIS MORNING. OTHERWISE...LIGHT AND VARIABLE WINDS WITH A GRADUALLY CLEARING SKY ARE EXPECTED. THURSDAY...MAX TEMPS WILL BE SLIGHTLY COOLER AS COMPARED WITH TODAY WITH HIGHS IN MOST LOCATIONS REMAINING IN THE MID 90S TO AROUND 100 DEGREES. POTENTIAL EXISTS ONCE AGAIN FOR CONVECTION DEVELOPING DURING THE LATE AFTERNOON HOURS. GIVEN OBSERVED PWAT VALUES AROUND 135 PERCENT OF NORMAL...LOCALLY HEAVY RAINFALL WILL ONCE AGAIN BE A THREAT. GUSTY OUTFLOW WINDS ALSO APPEAR TO BE POSSIBLE BASED ON POINT SOUNDINGS FROM ACROSS THE AREA. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 225 PM MDT WED AUG 1 2012 THURSDAY NIGHT-SATURDAY...FAIRLY ACTIVE WEATHER WILL CONTINUE THROUGH THE PERIOD AS STRONG SHORT WAVE TROUGH DIVES INTO THE NORTHERN PLAINS...FORCING STRONG COLD FRONT INTO THE TRI STATE AREA FRIDAY NIGHT AND SATURDAY...BRINGING SOME RELIEF FROM THE HEAT TO THE AREA BY SATURDAY AFTERNOON. NOT REAL CONFIDENT IN PRECIPITATION CHANCES ON THURSDAY EVENING WITH MAIN STATIONARY FRONT WELL TO THE SOUTH OF THE AREA AND LOW LEVEL FLOW BEING LIGHT AND GENERALLY WESTERLY. HOWEVER...PERIOD OF LARGE SCALE ASCENT WILL MOVE JUST NORTH OF THE CWA AND IF THE MUCH WEAKER CINH PROFILE OF THE NAM VERIFIES...THAT MAY BE ENOUGH TO INITIATE AT LEAST A FEW STORMS ALONG SFC TROUGH THAT EXTENDS INTO WESTERN CWA. GIVEN ABOVE CONCERNS AND SREF DATA REALLY FOCUSING BEST CHANCES NEAR FRONT DO NOT THINK OVERALL PATTERN REALLY WARRANTS MORE THAN 15-20 PERCENT. THINK BEST CHANCES FOR PRECIPITATION WILL BE DURING THE OVERNIGHT HOURS ON FRIDAY AS STRONG COLD FRONT SWEEPS ACROSS THE AREA...WHICH WILL NOT ONLY BRING A PERIOD OF STRONG NEAR SFC ASCENT BUT A PERIOD OF DEEPER ASCENT DEEP DIRECT CIRCULATION EXPECTED TO DEVELOP BEHIND FRONT COLOCATED WITH AREA OF LARGE SCALE ASCENT AS PER Q VECTOR ANALYSIS. WHILE FORCING WILL LIKELY BE THE STRONGEST ITS BEEN OUT OF THE PAST SEVERAL DAYS...STILL A LARGE AMOUNT OF UNCERTAINTY WITH RESPECT TO HOW MUCH INSTABILITY WILL BE AHEAD AND BEHIND FRONTAL ZONE AS EVIDENCED BY LARGE DIFFERENCES BETWEEN GEFS AND SREF PROBABILISTIC OUTPUT...AND THINK FOR THE TIME BEING THINK KEEPING POPS BELOW 50 PERCENT WARRANTED ATTM. IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...WHILE 06Z ROUND OF ENSEMBLES SHOWED LITTLE SPREAD IN OVERALL PATTERN STARTING TO SEE A BIT MORE UNCERTAINTY DEVELOP WITH RESPECT TO STRENGTH OF H5 RIDGE EXPECTED TO DEVELOP OVER THE ROCKIES THROUGH THE MIDDLE OF NEXT WEEK. SOME ENSEMBLES SEEM TO BE CLUSTERING TOWARDS BOTH THE MORE AMPLIFIED GFS WITH THE OTHERS MORE IN THE ECMWF CAMP WHICH CERTAINLY LOWERS CONFIDENCE IN TRYING TO PICK ONE MODEL OVER THE OTHER. FOR THE TIME BEING...THINK CONSENSUS APPROACH THE BEST BET FOR HIGH TEMPS FOR THE TIME BEING. TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD...BUT WITH POSSIBILITY OF CWA BEING ON NORTHEAST SIDE OF A FAIRLY AMPLIFIED RIDGE POTENTIAL FOR COOLER AIR BACKING INTO THE AREA KEEPS CONFIDENCE TOO LOW TO MAKE LARGE DEVIATIONS FOR MAX TEMPS. FOR LOWS...WITH SFC HIGH SETTLING OVER THE AREA ON SAT NIGHT BEHIND STRONG COLD FRONT AND AT LEAST A FEW HOURS OF LIGHT WINDS AND MUCH DRIER AIR COULD SEE FAIRLY CHILLY LOWS ACROSS MUCH OF THE CWA WITH VALUES IN THE MID TO UPPER 50S. PRECIP CHANCES DO NOT LOOK PARTICULARLY GREAT THROUGH THE PERIOD BOTH DUE TO MORE STABLE AIR MOVING IN BEHIND THE FRONT AND THEN WITH STRONG RIDGE DEVELOPING NEAR THE AREA. LEFT A FEW AREAS SMALL CHANCES...ESPECIALLY ON SAT DUE TO FRONTAL TIMING CONCERNS AND AGAIN ON WEDNESDAY AS GEFS DATA BRINGING FAIRLY HIGH PROBABILITIES OF MEASURABLE PRECIP OVERNIGHT TUES INTO WED MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1144 PM MDT WED AUG 1 2012 SCATTERED THUNDERSTORMS ARE MOVING EAST...DECREASING IN COVERAGE...AND BECOMING ISOLATED RAIN SHOWERS ACROSS THE CENTRAL HIGH PLAINS REGION. THISE ISOLATED SHOWERS WILL BE DIMINISHING BY ABOUT 08Z. VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AT BOTH KMCK AND KGLD WITH ANOTHER ROUND OF ISOLATED SHOWERS ACROSS THE REGION AFTER ABOUT 22Z THURSDAY AFTERNOON AND EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...LOCKHART SHORT TERM...FOLTZ LONG TERM...JRM AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS WICHITA KS
1155 PM CDT WED AUG 1 2012 .AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && ARL .PREV DISCUSSION... /ISSUED 928 PM CDT WED AUG 1 2012/ UPDATE... TRIMMED BACK POPS FOR CENTRAL KANSAS A LITTLE BEFORE 06Z AS THE ACTIVITY HAS BARELY ENTERED EXTREME NORTHWEST KANSAS AT THIS HOUR. AREAL COVERAGE OF POPS THOUGH LOOKS GOOD FROM 9Z ON SO LEFT THAT AS IS. GUSTY DOWNBURST WINDS ARE STILL POSSIBLE WITH STORMS THAT DO MAKE IT INTO THE AREA AS DCAPE VALUES EXTEND AS HIGH AT 2000 J/KG. ARL PREV DISCUSSION... /ISSUED 643 PM CDT WED AUG 1 2012/ AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU NOT MUCH CHANGE TO PREVIOUS FORECAST AS VFR CONDITIONS SHOULD DOMINATE MOST OF THE PERIOD FOR ALL SITES DUE TO 500MB RIDGE CENTERED OVER THE SOUTHERN HIGH PLAINS. MOISTURE FLOWING NORTHWARD AROUND THE WESTERN PERIPHERY OF THIS RIDGE IS CAUSING DIURNAL CONVECTION TO FORM OVER THE HIGH PLAINS AND BEGINNING TO SLOWLY DRIFT EAST/SOUTHEAST. WITH ELEVATED INSTABILITY IN NORTH CENTRAL KANSAS OVERNIGHT THE BEST SHOT AT SHOWERS STILL APPEARS TO BE AT RSL AND SLN AROUND 6 TO 12Z. WASN`T CONFIDENT ENOUGH TO ENTER VCTS AT HUT...ICT OR CNU...BUT WILL HAVE TO REEVALUATE FOR THE 12Z CYCLE. OVERNIGHT MCS COULD PROPAGATE AROUND TO THE SOUTHEAST ALONG A 850MB BAROCLINIC ZONE TOWARDS CNU BY 12Z...BUT DECIDED TO LEAVE THE VCTS OUT FOR THE MOMENT. WIND FORECAST IS ALSO TRICKY DUE TO POSSIBLE OUTFLOW FROM THE MCS AND THE SURFACE TROUGH THAT NOSES INTO SOUTH CENTRAL KANSAS...BUT THE GENERAL THEME IS THAT WINDS SHOULD MOSTLY BE OUT OF THE SOUTHEAST. LAUGEMAN PREV DISCUSSION... /ISSUED 325 PM CDT WED AUG 1 2012/ DISCUSSION... MESO HIGH FROM LAST NIGHTS/THIS MORNINGS CONVECTION HAS RESULTED IN A MUCH COOLER DAY THAN PREVIOUSLY ANTICIPATED OVER PORTIONS OF CENTRAL/EASTERN KS. ASSOCIATED OUTFLOW BOUNDARY EXTENDS EAST/WEST ACROSS NORTHERN OK...SO ANY ISOLATED CONVECTIVE DEVELOPMENT THIS AFTERNOON/EVENING WILL REMAIN SOUTH OF THE KS/OK BORDER. HOWEVER SIMILAR TO LAST NIGHT...WEAK MONSOONAL ENERGY ROUNDING TOP OF RIDGE COULD PROVIDE ANOTHER ROUND OF SHOWERS/THUNDERSTORMS OVER PORTIONS OF CENTRAL/EAST-CENTRAL KS AFTER MIDNIGHT...ALONG NORTHERN FRINGE OF STOUT 850-700MB THERMAL RIDGE. THINKING HIGHEST PROBABILITIES WILL REMAIN NORTH OF WICHITA. LIKE TODAY...ANY POTENTIAL CONVECTIVE OUTFLOW COULD THROW A WRENCH INTO THURSDAY MAX TEMPERATURES...WITH A WIDE RANGE OF TEMPERATURES LIKELY ACROSS THE BOUNDARY. DUE TO GOOD MIXING AND 30-34C 850MB TEMPERATURES...HIGHS SOUTH OF THE BOUNDARY SHOULD SOAR ABOVE 110 DEGREES...HIGHEST PROBABILITIES OVER SOUTHERN/SOUTHEAST KS. HOWEVER...DUE TO CONVECTIVE OUTFLOW UNCERTAINTIES...WILL PUNT HEAT HEADLINES DECISION TO THE NIGHT SHIFT. DUE TO THE VERY HOT TEMPERATURES AND BOUNDARY IN VICINITY...COULD SEE A FEW HIT-AND-MISS LATE AFTERNOON/EVENING THUNDERSTORMS OVER SOUTHERN KS THURSDAY...WITH ANOTHER ROUND OF SHOWERS/THUNDERSTORMS POSSIBLE THURSDAY NIGHT-EARLY FRIDAY OVER MAINLY CENTRAL KS...AS MORE WEAK MONSOONAL ENERGY TOPS RIDGE. ANOTHER VERY HOT FRIDAY IS ANTICIPATED...WITH AFTERNOON HIGHS LIKELY SOARING ABOVE 105 DEGREES FOR MANY AREAS. LIKE THURSDAY...CANNOT RULE OUT A FEW HIT-AND-MISS AFTERNOON/EVENING THUNDERSTORMS DUE TO WEAK BOUNDARY IN VICINITY. SHORT-MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST A COLD FRONT WILL PASS SOUTHEAST ACROSS THE REGION SATURDAY...ASSOCIATED WITH AN AMPLIFIED SHORTWAVE TROUGH OVER THE UPPER MISSISSIPPI VALLEY. AFTER ANOTHER HOT DAY OVER SOUTHERN/CENTRAL KS SATURDAY AHEAD OF THE FRONT...READINGS BY SUNDAY SHOULD DROP INTO THE 90S FOR MOST LOCATIONS BEHIND THE FRONT...WHICH WILL BE NEAR SEASONAL NORMALS. ADDITIONALLY...AT LEAST ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE ALONG THE FRONT LATE FRIDAY NIGHT...AND ESPECIALLY SATURDAY AFTERNOON/EVENING. HOWEVER...OTHER THAN ISOLATED RELIEF...WIDESPREAD APPRECIABLE RAINS APPEAR UNLIKELY. FOR MONDAY AND BEYOND...UNCERTAINTY EXISTS IN THE MODELS WHETHER THE ABNORMALLY WARM SUMMER TEMPERATURES WILL RETURN. ECMWF SUGGESTS RIDGE WILL BUILD BACK IN...RESULTING IN HOT AND DRY WEATHER RETURNING. HOWEVER...GFS AND ASSOCIATED ENSEMBLES KEEP THE RIDGE CENTERED WEST OF THE REGION...WHICH WOULD RESULT IN READINGS CLOSER TO SEASONAL NORMALS...ALONG WITH PERIODIC CHANCES FOR PRECIPITATION. WILL HOPE THAT THE GFS AND ASSOCIATED ENSEMBLES VERIFY. KLEINSASSER AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD. AN IMPRESSIVE CONVECTIVE OUTFLOW BOUNDARY AND THE EAST TO NORTHEAST WIND FLOW BEHIND IT WILL GRADUALLY WEAKEN THROUGH THE AFTERNOON ACROSS THE AREA. HOWEVER ANOTHER COMPLEX OF STORMS IS LIKELY TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING...WHICH COULD IMPACT CENTRAL KANSAS AGAIN EARLY THURSDAY MORNING. FOR NOW CONFIDENCE WAS ONLY HIGH ENOUGH TO INSERT VCTS AT KRSL AND KSLN. KED && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 106 77 106 77 / 10 10 10 20 HUTCHINSON 104 77 104 77 / 10 20 10 20 NEWTON 103 76 103 76 / 10 20 20 20 ELDORADO 103 77 104 77 / 10 20 20 20 WINFIELD-KWLD 108 78 109 78 / 10 10 10 20 RUSSELL 100 75 101 75 / 10 40 20 20 GREAT BEND 102 76 102 76 / 10 30 10 20 SALINA 100 75 101 75 / 10 40 20 20 MCPHERSON 102 76 102 76 / 10 30 20 20 COFFEYVILLE 108 78 108 78 / 10 10 20 20 CHANUTE 103 76 102 76 / 10 30 30 20 IOLA 102 75 101 75 / 10 30 30 20 PARSONS-KPPF 105 78 105 78 / 10 20 20 20 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAY ME
1211 AM EDT THU AUG 2 2012 .SYNOPSIS... LOW PRESSURE WILL TRACK EAST THROUGH THE SAINT LAWRENCE VALLEY TONIGHT... WITH A WEAK FRONT EXTENDING SOUTHWARD THROUGH NORTHERN NEW ENGLAND. ANOTHER LOW WILL TRACK THROUGH QUEBEC ON THURSDAY WITH A COLD FRONT PUSHING INTO THE AREA THURSDAY NIGHT AND FRIDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TODAY/... UPDATE... MINOR ADJUSTMENTS TO POPS AND QPF OVER THE NEXT FEW HRS. ONE CELL OVER N-CNTRL GRAFTON CO CONTS TO MOV E. THIS WILL SLOWLY DISSIPATE WITH TIME. OTRW...PATCHY FOG WILL CONT TO FORM OVERNIGHT AS DEW POINT VALUES REMAIN HIGH. REST OF FCST WILL REMAIN UNCHANGED AT THIS TIME. LATEST HRRR MODEL RUN HAS CONVECTION FIRING OVER THE NRN MTNS TODAY. TIMING APPEARS TO BE AROUND 1 PM AND THEREAFTER. PREVIOUS DISCUSSION... MAINE AND NEW HAMPSHIRE ARE CAUGHT BETWEEN TWO LOW PRESSURE SYSTEMS. THE FIRST MOVED THROUGH THE GULF OF MAINE AND INTO NOVA SCOTIA THIS MORNING... WHILE THE OTHER SPUN THROUGH THE SAINT LAWRENCE VALLEY. A WEAK TROUGH / COLD FRONT EXTENDS SOUTHWARD FROM THIS LOW ACROSS NEW HAMPSHIRE THIS AFTERNOON. THE COMBINATION OF LIFT FROM THE SHORTWAVE TROUGH ALOFT... WEAK CONVERGENCE AT THE SURFACE... AND MOIST AIR IN PLACE GENERATING WEAK INSTABILITY THIS AFTERNOON WILL LEAD TO A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS THROUGH EARLY EVENING. THESE SHOULD DISSIPATE IN LARGE PART AFTER SUNSET... BUT FURTHER NORTH CLOSER TO THE SURFACE LOW AND COLD CORE ALOFT... SHOWERS MAY CONTINUE INTO THE NIGHT. WITH A LOT OF MOISTURE AROUND... DEW POINTS IN THE MID 60S... FOG IS POSSIBLE TONIGHT. HOWEVER... EXPECT A LOT OF CLOUD COVER OVERNIGHT AFTER CONVECTION DEVELOPS AND IN ASSOCIATION WITH LIFT FROM THE SHORTWAVE TROUGH. THIS MAY LIMIT THE FOG POTENTIAL SOMEWHAT OVERNIGHT. TEMPERATURES STAY IN THE 60S OVERNIGHT DUE TO ALL THE MOISTURE IN PLACE. && .SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/... INITIAL SHORTWAVE TROUGH AXIS STILL LINGERS ACROSS THE AREA THROUGH THURSDAY. LIFT AHEAD OF THIS FEATURE WILL EXIST ESPECIALLY ACROSS MUCH OF MAINE AND COASTAL AREAS. THIS... IN COMBINATION WITH LOW LEVEL MOISTURE AND INSTABILITY... MAY LEAD TO SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE COASTAL PLAIN BY LATE MORNING. SURFACE BASED CAPE INDICATED BY THE NAM MODEL EXCEEDS 1200 AND WOULD BE ENOUGH FOR THUNDERSTORMS. SUBSIDENCE BEHIND THE SHORTWAVE TROUGH AXIS OVER NEW HAMPSHIRE SHOULD LIMIT SHOWER AND THUNDERSTORM COVERAGE HERE. FOR NOW HAVE INDICATED A CHANCE OF SHOWERS AND THUNDERSTORMS IN THIS AREA... WITH HIGHS IN THE 80S. ANOTHER SHORTWAVE TROUGH CROSSES THROUGH SOUTHERN CANADA... WITH A COLD FRONT PUSHING SOUTH TOWARD THE INTERNATIONAL BORDER THURSDAY NIGHT. COULD BE MORE SHOWER ACTIVITY PUSHING SOUTHWARD WITH THIS BY EARLY FRIDAY MORNING. MAY BE A BETTER POTENTIAL FOR FOG THURSDAY NIGHT AS MOISTURE LEVELS REMAIN HIGH AND SKY WILL BE MORE CLEAR AS DAYTIME SHOWERS DISSIPATE. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A WEAK COLD FRONT WILL SLOWLY PUSH ACROSS THE AREA ON FRIDAY...BUT FORCING IS QUITE WEAK...SO ONLY EXPECTING A FEW ISOLATED SHOWERS AND THUNDERSTORMS AS IT MEANDERS TO THE SOUTHEAST. A WEAK HIGH PRESSURE WILL BUILD IN BEHIND THE FOR THE WEEKEND...BUT A MUCH STRONGER COLD FRONT WILL MOVE IN FROM THE GREAT LAKES LATE SUNDAY. THERE IS SOME TIMING DIFFERENCES BETWEEN THE EURO AND GFS...WITH THE GFS DRAGGING THE FRONT ACROSS SUNDAY NIGHT INTO MONDAY MORNING...WHILE THE EURO BRINGS IT THROUGH EARLY MONDAY AFTERNOON. THE EUROS PASSAGE WILL MIRROR PEAK HEATING ON MONDAY. THIS SCENARIO...WITH A DECENT THERMODYNAMIC ENVIRONMENT...WILL GIVE US A GOOD CHANCE FOR THUNDERSTORM DEVELOPMENT BY MIDDAY MONDAY. WITH THE CURRENT UNCERTAINTY...STILL JUST LEAVING THINGS AS A CHANCE OF THUNDERSTORMS. AFTER THE FRONT PASSES...HIGH PRESSURE WILL BUILD IN AND KEEP THINGS QUIET THROUGH WEDNESDAY. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... SHORT TERM...EXPECTING MOSTLY VFR CONDITIONS AND LIGHT SOUTH TO SOUTHWESTERLY WINDS... BUT MVFR IN SHOWERS THIS EVENING IS POSSIBLE. BEST CHANCE OF THUNDER WILL BE OVER NEW HAMPSHIRE... AND IN PARTICULAR NORTHERN NEW HAMPSHIRE CLOSER TO THE SHORTWAVE TROUGH ALOFT. THERE IS THE POTENTIAL FOR NOCTURNAL FOG OVERNIGHT AS LOW LEVEL MOISTURE IS HIGH. HOWEVER... CLOUD COVER MAY BE TOO EXTENSIVE FOR FOG FORMATION AND CONFIDENCE IN FOG CAUSING REDUCED VISIBILITIES TONIGHT IS DECREASING. ON THURSDAY THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL PLAIN... WITH A BETTER CHANCE OF FOG THURSDAY NIGHT. LONG TERM... FRONTAL BOUNDARY COMING THROUGH ON MONDAY COULD DROP CIGS/VIS TO IFR/MVFR. && .MARINE... SHORT TERM...LIGHT SOUTH TO SOUTHWEST FLOW EXPECTED OVER THE WATERS TONIGHT AND TOMORROW. SEAS WILL SLOWLY SUBSIDE. LONG TERM... SCA CRITERIA MAY BE MET LATE SUNDAY INTO MONDAY AS A FRONTAL BOUNDARY APPROACHES THE AREA. && .EQUIPMENT... DUAL POLARIZATION UPGRADE OF THE GYX RADAR HAS BEEN COMPLETED. RADAR DATA IS NOW FLOWING THROUGH NORMAL CHANNELS. COMMUNICATIONS WITH KRKD SEEM TO HAVE BEEN RESTORED AGAIN. ISSUE MAY NOT BE PERMANENTLY RESOLVED. AS OBSERVATIONS CONTINUE TO COME IN THROUGH NORMAL CHANNELS THE TAF WILL BE PRODUCED AS NORMAL. HOWEVER... IF OBSERVATIONS DROP OUT AGAIN THEN THE "AMD NOT SKED" REMARK MAY HAVE TO BE ADDED AGAIN. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ JC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 AM EDT THU AUG 2 2012 .UPDATE... ISSUED AT 934 PM EDT WED AUG 1 2012 CONVECTIVE TRENDS MAIN ISSUE FOR THE LATE EVENING AND OVERNIGHT. LOW PRESSURE OVR NORTH END OF LK SUPERIOR WHILE COLD FRONT IS CLOSING IN ON FAR WESTERN UPR MICHIGAN. THERE ARE TWO MAIN SHORTWAVE TROUGHS OVR THE REGION. FIRST WAVE IS PUSHING ACROSS EASTERN LK SUPERIOR AND COMBINED WITH H85 THETA-E ADVECTION HAS DRIVEN SHRA/TSRA THAT HAVE BEEN ROAMING OVER EASTERN LK SUPERIOR AND FAR EASTERN CWA THIS EVENING. SECOND WAVE IS PUSHING INTO WESTERN MINNESOTA AND HAS KICKED OFF COMPLEX OF STRONG TSRA OVER SW MINNESOTA. ANOTHER WAVE IS UPSTREAM OVR SOUTHERN MANITOBA AND MAY HAVE AFFECT ON WX LATER TONIGHT. CONVECTION OVR WEST HALF OF UPR MICHIGAN PRETTY MUCH NIL THIS EVENING DESPITE HIGHER INSTABILITY /MLCAPES UPWARDS OF 2000 J/KG AND APPROACHING COLD FRONT. MAIN REASON FOR MINIMAL CONVECTION IS PROBABLY LARGE AREA OF MINIMUM H7 DWPNT...WHICH IS LIKELY EXTENDING LOWER INTO THE LOWER LAYERS OF THE ATMOSPHERE. RUC INDICATES INCREASE OF H7 MOISTURE AFT MIDNIGHT AS THE COLD FRONT PUSHES INTO CNTRL UPR MICHIGAN. THE INCREASED MOISTURE H85-H7 MOISTURE ADVECTION INTO THE FRONT IN PRESENSE OF THE UPSTREAM SHORTWAVE OVR MANITOBA COULD BE ENOUGH TO TRIGGER SHRA/TSRA OVERNIGHT MAINLY OVER THE SOUTH INTO THE EASTERN CWA. STILL A RISK OF ISOLD STRONGER STORMS AS INSTIBILITY AND SHEAR REMAIN MORE THAN SUFFICIENT. AFTER LATE TONIGHT...GOING FLAVOR OF PREVIOUS FCST STILL THERE WITH COLD FRONT STALLING OUT OVR SOUTH CENTRAL CWA ON THURSDAY. POPS REMAIN SLIGHT CHANCE FOR NOW FOR THIS...BUT MAY NEED INCREASING LATER TONIGHT ONCE NEXT UPSTREAM WAVE IS SORTED OUT. ONLY CHANGE OF NOTE FOR FCST WAS TO RESTRUCTURE POPS THROUGH THE OVERNIGHT BASED ON LATEST MESOANALYSIS/RADAR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 327 PM EDT WED AUG 1 2012 A 1002MB SFC LOW IS CENTERED JUST NW OF LAKE SUPERIOR WITH AN ASSOCIATED MID/UPPER LEVEL SHORTWAVE OVERHEAD. A SFC COLD FRONT IS CURRENTLY STRETCHED FROM THE SFC LOW SW TO FAR NRN MN. ANOTHER SHORTWAVE RIDING OVER THE UPPER RIDGE OVER THE WRN CONUS WAS LOCATED JUST N OF LAKE SUPERIOR AT 14Z TODAY...CAUSING THUNDERSTORMS TO MOVE N OF LAKE SUPERIOR. ANOTHER CLUSTER OF THUNDERSTORMS WAS OVER ERN MN LATE THIS MORNING...WHERE MORE MOISTURE WAS PRESENT. BY AROUND 17Z TODAY...THE STORMS MADE THEIR WAY INTO FAR WRN UPPER MI NEAR IWD...AND ARE NOW /19Z/ LOCATED OVER WRN IRON/SRN HOUGHTON COUNTIES. A COUPLE OF THE STORMS WERE STRONGER NEAR IWD...AND A COUPLE WERE SEVERE JUST S OF GOGEBIC COUNTY. CLEARING BEHIND THESE STORMS...ALONG WITH ALREADY HIGH SFC DEW PTS...MAY LEAD TO INCREASED INSTABILITY OVER FAR WRN UPPER MI LATE THIS AFTERNOON. THERE IS A RISK FOR SOME STRONGER THUNDERSTORMS OVER THE FAR W INTO THIS EVENING. DRY AIR OVER THE AREA HAS LEAD TO LARGE DCAPES...SO STRONG WINDS WOULD BE A THREAT WITH ANY SIGNIFICANT CONVECTION. MLCAPES UP TO 2000J/KG WILL BE POSSIBLE WITH 0-6KM SHEAR OF 30-40KTS...ALSO LEADING TO A HAIL THREAT. MODEL QPF VARIES WIDELY FROM MODEL TO MODEL...FURTHER LIMITING CONFIDENCE IN COVERAGE THIS EVENING THROUGH TONIGHT. OVERALL...BEST CHANCES FOR CONVECTION WILL BE THIS AFTERNOON INTO THIS EVENING ALONG THE WI BORDER OVER THE W. 850MB TEMPS TODAY WERE AROUND 20C...BUT NW WINDS BEHIND THE COLD FRONT TOMORROW WILL KEEP 850MB TEMPS AROUND 15C S TO 11C N...SO TEMPS WILL QUITE A BIT COOLER /ESPECIALLY NEAR LAKE SUPERIOR/. THIS WILL LEAD TO HIGHS IN THE 70S N TO 80S S. SINCE THE COLD FRONT LOOKS TO BE S OF THE CWA BY 12Z THU...WILL CUT BACK POPS FROM PREVIOUS SHIFT. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 327 PM EDT WED AUG 1 2012 HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES...BEHIND THE COLD FRONT WHICH WILL BE MOVING ACROSS THE LOWER GREAT LAKES AND NEW ENGLAND STATES. WHILE THE CENTER OF THE SFC LOW WILL REMAIN TO OUR NE...LIGHT WINDS WILL PREVAIL...WITH SOME RETURN FLOW OVER THE W HALF CLOSER TO THE NEARING SFC LOW OVER THE PLAINS STATES THROUGH MANITOBA. NORTHWEST FLOW WILL CONTINUE ALOFT THURSDAY NIGHT...WITH THE MAIN 500MB LOW STILL SPINNING OVER NE HUDSON BAY/N QUEBEC...AND THE NEXT LOW PUSHING ACROSS THE PACIFIC NW/SW CANADA. SLIGHT RIDGING TO ZONAL FLOW FRIDAY...OUT AS THE WESTERN 500MB LOW DIGS ACROSS THE DAKOTAS. THE LOW WILL CONTINUE TO DEEPEN AS IT SHIFTS ACROSS N MN/W ONTARIO BY 18Z SATURDAY. THE GFS/CANADIAN ARE MORE PROGRESSIVE WITH THE 500MB LOW /NEAR JAMES BAY/...WHILE THE ECMWF IS STILL OVER N LS AND CENTRAL ONTARIO. WINDS JUST ABOVE THE SFC FRIDAY NIGHT COULD BE QUITE STRONG...WITH NEARLY UNIDIRECTIONAL SW WINDS OF 30-40KTS AT AND ABOVE 925MB. SOME DRY AIR AT THE SFC INITIALLY SHOULD PRECLUDE STRONG TS DEVELOPMENT...BUT COULD DEPEND ON THE LOCATION OF THE WARM FRONT. MLCAPE VALUES JUMP TO 500-1100J/KG OVER THE W LAND AWAY FROM THE KEWEENAW PENINUSLA BY 12Z SATURDAY...WITH 45-55KT LLJ OVER THE ENTIRE W HALF. THIS STRONG WAA SHOULD KEEP TEMPS FROM FALLING MUCH BELOW 65F...PARTICULARLY OVER THE W HALF DOWNSLOPE LOCATIONS NEAR LS. 850MB TEMPS JUMP TO AROUND 18C SATURDAY AFTERNOON CWA WIDE UNTIL THE PASSAGE OF THE COLD FRONT BY MID/LATE AFTERNOON W. NO MATTER WHICH SOLUTION PANS OUT ALOFT...NW FLOW WILL RETURN BY SUNDAY NIGHT THROUGH MID DAY TUESDAY. LINGERING CLOUDS ON FAVORABLE NW WINDS AND 850MB TEMPS OF 7-8C SHOULD KEEP A FEW CLOUDS SET UP N CENTRAL AND E SUNDAY MORNING. A FEW DIFFICULT TO PREDICT SHORTWAVES LOOK TO SWING THROUGH OR TO OUR N IN THE FAST NW FLOW. THE LARGE SCALE TROUGH SET UP FROM CENTRAL CANADA THROUGH THE MID ATLANTIC WILL BRING MORE ZONAL FLOW TO THE UPPER GREAT LAKES ON WEDNESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 134 AM EDT THU AUG 2 2012 A LOW PRESSURE SYSTEM CROSSING NORTHERN PORTIONS OF LAKE SUPERIOR WILL PUSH A COLD FRONT ACROSS UPR MICHIGAN BY DAYBREAK THIS MORNING. STILL SOME CONCERN THAT ISOLD SHRA/TSRA COULD AFFECT TAF SITES EARLY THIS MORNING. AT THIS POINT...BEST CHANCE WOULD PROBABLY BE AT SAW BEFORE SUNRISE AS COLD FRONT APPROACHES AND ADDITIONAL SUPPORT IS PROVIDED BY UPPER LEVEL DISTURBANCE. ANY RISK OF SHRA/TSRA WILL BE OUT OF THE TAF SITES BY MID MORNING AT THE LATEST. ATTN REST OF THE DAY WILL BE ON POST-FRONTAL LOWER CLOUDS. BASED ON UPSTREAM CIGS IN MANITOBA AND ONTARIO LAST EVENING AND EARLY THIS MORNING...SCT-BKN STRATOCU CLOUDS ARE EXPECTED...ESPECIALLY GIVEN DEVELOPING NORTHERLY WINDS OFF LK SUPERIOR. AFTER A PERIOD OF LOWER CIGS IN THE MVFR RANGE...EXPECT SKIES TO SCATTER OUT MID-LATE AFTERNOON AS HIGH PRESSURE BUILDS INTO THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 327 PM EDT WED AUG 1 2012 A LOW PRESSURE SYSTEM MOVING THROUGH SOUTHERN CANADA TODAY AND TONIGHT WILL SWEEP A COLD FRONT ACROSS LAKE SUPERIOR. EXPECT SW WINDS AHEAD OF THIS FRONT TO GUST TO 20KTS BEFORE SHIFTING TO THE NW TO 20KTS OVERNIGHT. A HIGH PRESSURE RIDGE WILL THEN SETTLE BACK OVER LAKE SUPERIOR THURS INTO FRI. A STRONGER LOW PRESSURE SYSTEM DEVELOPING NEAR LAKE WINNIPEG ON FRIDAY WILL SHIFT ENE TO JAMES BAY BY SUNDAY MORNING AND SWEEP A COLD FRONT ACROSS LAKE SUPERIOR ON SATURDAY. WINDS COULD GUST TO 25KTS THIS WEEKEND AS THE SYSTEM MOVES THROUGH. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...TITUS LONG TERM...KF AVIATION...JLA MARINE...TITUS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1222 AM CDT THU AUG 2 2012 .AVIATION.../06Z TAF ISSUANCE/ SHOWERS OVER THE SOUTHERN TERMINALS WILL MOVE OUT OF BRD BY 07Z AND 09Z AT HYR. SHOWERS NORTH OF INL WILL MOVE AWAY BY 07Z. SKIES WILL PARTIALLY CLEAR BY DAYBREAK WHICH MAY LEAD TO A FEW FOG PATCHES. HAVE TEMPO GROUPS FOR VISIBILITIES BETWEEN 3SM AND 5SM TO ACCOUNT FOR THIS. VFR CONDITIONS WILL PREVAIL THROUGH THE DAYLIGHT HOURS ON WEDNESDAY WITH NORTHWESTERLY WINDS UNDER 10 KNOTS. && .PREV DISCUSSION... /ISSUED 740 PM CDT WED AUG 1 2012/ SHORT TERM... CURRENTLY...NO THUNDERSTORMS WERE OCCURRING OVER THE CWA. WE HAD A BRIEF STORM DEVELOP OVER SOUTHERN PINE COUNTY AROUND 2330Z IN AN AREA OF ENHANCED CU THAT HAS BEEN MOVING EAST OVER THE PAST COUPLE HOURS. STABILITY IS IMPRESSIVE THIS EVENING...WITH MUCAPE AROUND 3000J/KG OVER NORTHWEST WISCONSIN...TO A 1000 J/KG OVER THE INTERNATIONAL BORDER REGION. HOWEVER...LIFT IS QUITE MARGINAL WITH MID LEVEL ENERGY FURTHER NORTH AND WEST PASSING THROUGH SOUTHERN MANITOBA...AND STRONGER LOW LEVEL FGEN FORCING FURTHER SOUTH OVER SOUTHERN MINNESOTA INTO SOUTH DAKOTA. THERE IS SOME WEAK LOW LEVEL CONVERGENCE...SEEN IN THE SURFACE OBS...WITH W-NW FLOW AT KRZN/KDLH/K04W AND LIGHT SW FLOW AT KPBH AND KASX. THE RAP SHOWS LITTLE 925MB CONVERGENCE. WE CAN`T RULE OUT A THUNDERSTORM OVER THE NEXT FEW HOURS OVER NORTHWEST WISCONSIN AS THE WEAK LOW LEVEL CONVERGENCE MOVES THROUGH. WE ALSO COULD GET BRUSHED WITH THE COMPLEX OF STORMS THAT WERE AFFECTING SOUTHERN/CENTRAL MN AND SOUTH DAKOTA AS IT CONTINUES E-SE. HOWEVER...CHANCES OF THAT ARE LOW. FURTHER NORTH...A SHORTWAVE SEEN ON SATELLITE AND IN THE RAP`S 1.5 PV SURFACE...WILL AFFECT FAR NORTHERN MINNESOTA AND COULD BRING A FEW SHOWER OR STORMS TO THAT AREA LATER THIS EVENING. WE MAY HAVE TO EXTEND AND EVEN INCREASE POPS A BIT AFTER 03Z IN THE FAR NORTH. PREV DISCUSSION... /ISSUED 626 PM CDT WED AUG 1 2012/ AVIATION.../0Z TAF ISSUANCE/ COLD FRONT HAS MOVED THROUGH THE TERMINALS WITH NORTHWESTERLY WINDS. MAIN AREA OF SHOWER AND THUNDERSTORM ACTIVITY WILL STAY TO OUR SOUTH. HAVE INCLUDED SOME TEMPO GROUPS TO ACCOUNT FOR THE DEVELOPMENT OF PATCHY FOG BEFORE DAWN. VISIBILITIES MAY FALL TO 1SM AT HIB...DLH...AND HYR. WINDS WILL STAY LIGHT NORTHWESTERLY THROUGH THE TAF FORECAST PERIOD. PREV DISCUSSION... /ISSUED ISSUED BY NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN/ DISCUSSION... PRIMARY FORECAST CONCERNS ARE CHANCES FOR TSRA THIS LATE THIS AFTERNOON INTO THIS EVENING AS THE COLD FRONT MOVES THROUGH THE REMAINDER OF THE AREA... THEN CHANCES FOR MORE WIDESPREAD SHRA/TSRA FRIDAY NIGHT INTO SATURDAY MORNING AS THE NEXT SHORTWAVE AND COLD FRONT MOVE THROUGH THE AREA. LATEST WATER VAPOR IMAGERY SHOWS THE SAME BASIC UPPER AIR PATTERN WE/VE SEEN FOR MUCH OF THE SUMMER... WITH A BROAD UPPER RIDGE ENCOMPASSING MOST OF THE CENTRAL CONUS. THE SHORTWAVE CURRENTLY RIDING ALONG THE US/CANADIAN BORDER NEAR THE MONTANA/NORTH DAKOTA BORDER WILL CONTINUE TO DRIVE EAST TONIGHT... HELPING TO FINALLY PUSH THE COLD FRONT CURRENTLY OVER MINNESOTA EAST THROUGH THE REMAINDER OF THE AREA. SPC MESOANALYSIS SHOWS GOOD INSTABILITY ALONG AHEAD OF THE FRONT... WITH MLCAPE AOA 2500 J/KG. SOME INSTABILITY LAGS THE SURFACE BOUNDARY AS WELL... WHICH IS HELPING TO KEEP ACTIVITY GOING TO THE WEST... AND NECESSITATES LEAVING POPS IN THE FORECAST ACROSS THE AREA THROUGH AT LEAST EARLY EVENING AS THE UPPER WAVE MOVES TOWARD THE FORECAST AREA. WE SHOULD MANAGE TO CLEAR THE PCPN OUT OF ALL BUT PERHAPS THE SOUTHEAST PORTION OF THE AREA OVERNIGHT AS THE FRONT CONTINUES EAST AND A WEAK SURFACE RIDGE TRIES TO WORK INTO THE AREA. THERE COULD BE SOME AREAS OF FOG LATE TONIGHT WITH WINDS DYING AND CLOUD COVER DECREASING... BUT THAT WILL LIKELY DEPEND ON ANY RE-WETTING OF THE GROUND WHICH CAN OCCUR WITH PCPN THROUGH EARLY THIS EVENING... SO OPTED TO LEAVE IT OUT OF THE FORECAST FOR NOW. IT SHOULD BE PARTLY CLOUDY AND DRY OVER MOST OF THE AREA ON THURSDAY AS THE SURFACE HIGH DRIFTS ACROSS THE AREA. HOWEVER... THE ARROWHEAD COULD SEE SOME AFTERNOON PCPN DEVELOP GIVEN BETTER PROXIMITY TO THE MID-LEVEL COLD POOL MOVING NORTH AND NORTHEAST OF THE AREA DURING THE DAY. AFTER TOMORROW ATTENTION WILL TURN TOWARD THE SHORTWAVE CURRENTLY DROPPING THROUGH BRITISH COLUMBIA. THIS WAVE IS EXPECTED TO CONTINUE EAST-SOUTHEAST THROUGH THE NEXT FEW DAYS... WORKING INTO THE HIGH PLAINS BY FRIDAY... THEN CONTINUING EAST ACROSS THE FORECAST AREA SATURDAY INTO SUNDAY. DECENT RETURN FLOW AND WARM ADVECTION IS EXPECTED AHEAD OF THIS FEATURE... AND THE NAM... GFS... AND ECMWF ARE ARE IN REASONABLY AGREEMENT ON THE DEGREE OF INSTABILITY AND FORCING ASSOCIATED WITH ITS PASSAGE. THERE ARE STILL SOME TIMING DIFFERENCES... WHICH RESULT IN HAVING A LONGER PERIOD BLANKETED WITH POPS THAN WILL LIKELY OCCUR... BUT AS THINGS GET CLOSER IN TIME THOSE WILL BE REFINED AND LIKELY INCREASED FOR THE FROPA AND SHORTWAVE ARRIVAL WHICH CURRENTLY LOOKS TO OCCUR FRIDAY NIGHT INTO SATURDAY MORNING. INCLUDED CHANCE-LIKELY POPS WITH THIS SYSTEM FRIDAY NIGHT INTO SATURDAY... THEN TAPERED THING BACK SATURDAY NIGHT AS THE FRONT MOVES WELL TO THE EAST BUT CYCLONIC BOUNDARY LAYER FLOW AND AND MID-UPPER COLD POOL LINGER OVER THE AREA. IMPRESSIVE RIDGING LOOKS TO ARRIVE AND KEEP THINGS BENIGN SUNDAY THROUGH MONDAY... WITH A SMALL CHANCE FOR SOME PCPN MONDAY NIGHT AS A WEAK FRONTAL BOUNDARY DROPS SOUTH THROUGH THE AREA. THE MAIN CHANCES LOOK TO BE OVER THE SOUTHERN PORTION OF THE AREA WITH THAT FEATURE... SINCE IT APPEARS IT WILL TAKE A WHILE FOR THINGS TO SATURATE IF THEY DO AT ALL GIVEN THE DRYNESS OF THE ANTECEDENT AIRMASS. PCPN CHANCES SHOULD RETURN BY THE MIDDLE OF THE WEEK AS WE GET ONTO THE BACKSIDE OF THE SURFACE HIGH AND A FEW SHORTWAVES DROP SOUTHEAST INTO THE AREA ON THE PREVAILING NORTHWEST FLOW. && .POINT TEMPS/POPS... DLH 64 79 60 77 / 20 10 10 30 INL 60 79 60 78 / 30 10 20 50 BRD 63 84 62 84 / 30 10 10 50 HYR 65 82 60 82 / 30 10 10 20 ASX 68 77 61 78 / 20 10 0 20 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ AVIATION...KK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
348 AM CDT THU AUG 2 2012 .DISCUSSION... SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS INTO THE UPPER 90S IF NOT LOWER 100S. A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY 00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY. SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING. CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO SATURDAY MORNING. COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE 80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE BUILDS TO OUR WEST. && .AVIATION... 06Z TAFS FOR KOMA...KLNK...AND KOFK. SHRA/TSRA CURRENTLY IN THE KOFK AREA. OUTFLOW FROM THE STORMS MAY GENERATE SOME NORTHWEST WINDS 10 TO 20KTS AS IT GETS TO KOMA AND KLNK. INCLUDED THIS IN THE TAF AS WELL AS SHRA AND ISOLATED TSRA THROUGH 11Z. CONTINUED VFR CONDITIONS...HOWEVER MVFR CONDITIONS MAY DEVELOP WITH SOME OF THE STORMS. STORMS MAY TRY TO HANG ON INTO THE MORNING HOURS...HOWEVER CONFIDENCE LOW ENOUGH NOT TO INCLUDE PAST 12Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1154 PM CDT WED AUG 1 2012 .AVIATION... 06Z TAFS FOR KOMA...KLNK...AND KOFK. SHRA/TSRA CURRENTLY IN THE KOFK AREA. OUTFLOW FROM THE STORMS MAY GENERATE SOME NORTHWEST WINDS 10 TO 20KTS AS IT GETS TO KOMA AND KLNK. INCLUDED THIS IN THE TAF AS WELL AS SHRA AND ISOLATED TSRA THROUGH 11Z. CONTINUED VFR CONDITIONS...HOWEVER MVFR CONDITIONS MAY DEVELOP WITH SOME OF THE STORMS. STORMS MAY TRY TO HANG ON INTO THE MORNING HOURS...HOWEVER CONFIDENCE LOW ENOUGH NOT TO INCLUDE PAST 12Z. && .PREV DISCUSSION... /ISSUED 1004 PM CDT WED AUG 1 2012/ UPDATE... DID AN EVENING UPDATE A LITTLE EARLIER TO ACCOUNT FOR HIGHER POPS IN THE NORTHEAST AND CONTINUED SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FARTHER SOUTHEAST OVERNIGHT. DISCUSSION... THE EVENING OAX SOUNDING WAS ON THE DRY SIDE WITH LESS THAN ONE INCH PRECIP WATER...LBF HOWEVER HAD A MUCH MORE FAVORABLE SOUNDING WITH AROUND 3200 J/KG FOR CAPE AND LITTLE CINH AND 1.34 FOR PRECIP WATER. THE MOISTURE TRANSPORT VECTORS CONTINUE TO BRING THE MOISTURE EASTWARD AND SOUTHWARD...SO SCATTERED POPS STILL SEEM ON TRACK. GUSTY WINDS ARE POSSIBLE WITH DOWNDRAFT CAPE OF 1800 J/KG. SO FAR HAVE HAD REPORTS OF 40 TO 50 MPH NEAR NELIGH. THE NEW NAM TRIES TO HOLD ON TO THE PRECIPITATION THURSDAY MORNING FARTHER NORTH SO THIS WILL NEED TO BE ASSESSED. && PREV DISCUSSION... /ISSUED 501 PM CDT WED AUG 1 2012/ DISCUSSION... IT APPEARS THAT A SHORT REPRIEVE FROM THE OPPRESSIVE DRY CONDITIONS THAT HAVE PLAGUED US AS OF LATE IS ON THE HORIZON AS A COUPLE OF COLD FRONTS APPROACH THE PLAINS. RADAR LOOP WAS SHOWING PCPN ACTIVITY OVER WESTERN NEBRASKA AND PARTS OF SOUTH DAKOTA WHILE LATEST OBS WERE DEPICTING A BNDRY EXTENDING ALONG THE ND/SD BORDER WITH CAA SLOWLY SPREADING SWD OVER NRN SD. THE BIG QUESTION IS WILL THIS RESULT IN PCPN OVER THE CWA LATER TONIGHT. IT SEEMS THE MODELS ARE TRYING TO STALL THE FRONT IN THE VICINITY OF THE NRN CWA...BUT GOOD CHUNK OF DPVA DOES CROSS THE CWA...AND WITH STOUT 315K UPGLIDE NOT UNREASONABLE AT THIS POINT TO EXPECT SOME HIGH BASED ACTIVITY DEVELOPING. LATEST HRRR SEEMS TO HAVE A DECENT HANDLE ON THINGS... WHICH SUGGEST ACTIVITY COULD GET INTO EASTERN NEBRASKA BEFORE MIDNIGHT. CHANCES FOR ANOTHER ROUND PCPN ARE ON TAP HEADING INTO THE WEEKEND. MODELS ARE IN VERY GOOD AGREEMENT THAT UPSTREAM SHORTWAVE TROF OVER BRITISH COLUMBIA WILL SLIGHTLY BREAK DOWN THE CONUS UPPER RIDGE AS IT DROPS INTO THE LOWER 48. THE THERMAL GRADIENT WITH THE ATTENDANT COLD FRONT WILL BE MORE STOUT IN NATURE. WITH DECENT ENVIRONMENTAL MOISTURE ON HAND... PRECIP WATER VALUES AROUND 2"/KI OF 40...IS REASONABLE TO MAINTAIN POPS FRIDAY NIGHT. POSSIBLE LINGERING ACTIVITY THEN SATURDAY MORNING OVER THE SRN CWA. RELATIVELY COOLER AFTN HIGHS IN THE MID 80S THEN SUNDAY AFTERNOON. HEADING INTO NEXT WEEK...THE SITUATION LOOKS RATHER BLEAK WITH DRY CONDITIONS AND HIGH TEMPS PUSHING BACK TO THE MID/UPPER 90S AS AN UPPER RIDGE RETURNS OVER THE CONUS. DEE/BCM && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY
AREA FORECAST DISCUSSION UPDATE
NWS LAS VEGAS NV
1054 PM PDT WED AUG 1 2012 .SYNOPSIS...A DISTURBANCE IN THE ATMOSPHERE COMBINED WITH ABUNDANT MOISTURE AND INSTABILITY WILL RESULT IN SHOWERS AND THUNDERSTORMS AROUND AT TIMES THROUGH THIS WEEKEND. ALTHOUGH HEAVY RAIN WILL BE THE PRIMARY THREAT WITH HEAVIER STORMS...GUSTY WINDS AND HAIL MAY ALSO OCCUR. BY EARLY NEXT WEEK DRIER AIR LOOKS TO SLOWLY SPREAD EAST ACROSS THE AREA WHICH SHOULD DECREASE THE CHANCES FOR THUNDERSTORMS AND ALSO RESULT IN A WARMING TREND. && .UPDATE... THE OUTFLOW BOUNDARY ASSOCIATED WITH THE LINE OF THUNDERSTORMS PREVIOUSLY EXPECTED TO PASS ACROSS THE LAS VEGAS VALLEY AND FURTHER SOUTH HAVE DISSIPATED AS THE OUTFLOW BOUNDARY ASSOCIATED WITH THE STORMS HAD MOVED OUT TOO FAR AHEAD OF THE LINE OF STORMS...AND CUT OFF FAVORABLE INFLOW TO STORMS DESPITE LIS BETWEEN -3 AND -5 AND CAPE VALUES FROM 1000 TO 2000 J/KG. THE FLASH FLOOD WATCH HAS BEEN CANCELLED...AND ANY MENTION OF SHOWERS OR THUNDERSTORMS HAVE BEEN REMOVED FROM THE OVERNIGHT FORECAST. STILL EXPECT SUFFICIENT MOISTURE TO BE IN PLACE FOR A CHANCE OF CONVECTION TOMORROW...BUT NEED TO FURTHER ASSESS HOW MUCH ANY EXPECTED WARMING AND DRY AIR MOVING IN ALOFT WILL MITIGATE DEVELOPMENT. -KENNEDY- && .AVIATION...FOR MCCARRAN...NO SIGNIFICANT WEATHER IS EXPECTED THE REMAINDER OF THE NIGHT. THERE WILL BE A CHANCE OF THUNDERSTORMS ONCE AGAIN ON THURSDAY...AS SUFFICIENT MOISTURE REMAINS IN PLACE FOR THUNDERSTORM DEVELOPMENT. THUNDERSTORMS WILL DEVELOP INITIALLY OVER HIGHER TERRAIN. OUTSIDE OF ANY THUNDERSTORM OUTFLOWS...WINDS WILL BE RELATIVELY LIGHT. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...NO SIGNIFICANT WEATHER IS EXPECTED THE REMAINDER OF THE NIGHT AS THUNDERSTORMS HAVE DISSIPATED ACROSS THE FORECAST AREA. THERE WILL BE A CHANCE OF THUNDERSTORMS ACROSS THE REGION AGAIN TOMORROW...AS SUFFICIENT MOISTURE REMAINS IN PLACE. THUNDERSTORMS WILL DEVELOP INITIALLY OVER HIGHER TERRAIN. OUTSIDE OF ANY THUNDERSTORM OUTFLOWS...WINDS WILL BE RELATIVELY LIGHT. -KENNEDY- && .PREV DISCUSSION... 331 PM PDT WED AUG 1 2012 .SHORT TERM...SO FAR THINGS HAVE NOT BEEN AS ACTIVE THIS AFTERNOON AS THEY WERE AT THIS POINT YESTERDAY DESPITE AN EXTREMELY MOIST ATMOSPHERE...PLENTY OF INSTABILITY AND MUCH MORE SUNSHINE. WATER VAPOR IMAGERY SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW WAS OVER SOUTHERN CLARK COUNTY AND MOVING SLOWLY NORTHEASTWARD. RADAR SHOWS AT THE PRESENT MOST OF THE ACTIVITY WAS ABOUT 100 MILES AWAY FROM THE CENTER OF THE LOW. THE ATMOSPHERE REMAINS EXCEPTIONALLY MOIST WITH THE 12Z SOUNDING THIS MORNING FROM OUR OFFICE HAVING A PWAT OF 1.82 INCHES. THIS TIED FOR THE SECOND HIGHEST PWAT EVER RECORDED IN THE SOUNDING CLIMATOLOGY FOR SOUTHERN NEVADA WITH A VALUE BACK IN AUGUST OF 1984 (THE HIGHEST EVER WAS 1.86 INCHES IN JULY 1966). WITH SO MUCH MOISTURE PRESENT ANY SHOWER OR THUNDERSTORM THAT GETS GOING WILL HAVE THE POTENTIAL TO PRODUCE EXTREMELY HEAVY RAIN IN A SHORT PERIOD OF TIME. THUS THE FLASH FLOOD WATCH OUT WILL REMAIN IN EFFECT. THE MAIN CHALLENGE FOR THIS EVENING AND THE REST OF TONIGHT WILL BE JUST HOW ACTIVE THINGS WILL GET. WITH THE MID/UPPER LEVEL LOW PROGGED TO BE AROUND THROUGH TONIGHT IT WILL BE HARD TO COMPLETELY SHUT DOWN ALL CONVECTION EXCEPT IN ANY AREAS WHERE THE AIR MASS GETS WORKED OVER ENOUGH THAT IT BECOMES MUCH MORE STABLE. IF YOU BELIEVE THE WRF...GFS AND ECMWF CONVECTION SHOULD WIND DOWN AROUND 03Z OR SO THIS EVENING. ON THE OTHER HAND...THE LOCAL ARW AND NMM MODELS AS WELL AS THE HRRR MODEL SHOW THE REVERSE WITH THINGS BECOMING MUCH MORE ACTIVE LATER THIS EVENING. 700 MB STEERING FLOW IS FROM THE NORTHEAST AND RADAR PRESENTLY SHOWS SHOWERS AND THUNDERSTORMS IN AN ARCH FROM AROUND ELY TO KANAB. TYPICALLY THIS PATTERN WOULD FAVOR THIS CONVECTION EVENTUALLY WORKING IN DURING THE LATE EVENING INTO CLARK COUNTY. IN THE PAST STORMS IN LAS VEGAS ORIGINATING FROM A NORTHEAST FLOW HAVE USUALLY BEEN RATHER POTENT. THUS...BASED ON A BLEND OF MODELS WE HAVE KEPT POPS IN THROUGH THE NIGHT FOR MUCH OF LINCOLN...CLARK...MOHAVE....EASTERN SAN BERNARDINO AND SOUTHERN NYE COUNTIES. ALTHOUGH FLASH FLOODING REMAINS A THREAT...WE CANNOT RULE OUT GUSTY WINDS OR HAIL WITH SOME STORMS ESPECIALLY IF THINGS DRY OUT A LITTLE. VERY LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED FOR THURSDAY AND FRIDAY. THE MID/UPPER LEVEL LOW IS FORECAST TO GET TRAPPED NEAR THE TRIPLE POINT OF CALIFORNIA...NEVADA AND ARIZONA AND EVENTUALLY WEAKEN TO A MORE ILL-DEFINED VORTICITY FEATURE. MEANWHILE HIGH PRESSURE IN THE MID AND UPPER LEVELS IS FORECAST TO BECOME CENTERED OVER CENTRAL NEVADA. THIS HIGH WILL KEEP AN EASTERLY MID-LEVEL FLOW OVER OUR AREA WHICH BY FRIDAY WILL HELP TO PUSH THE VORTICITY FEATURE TO THE SOUTHWEST AND BY FRIDAY NIGHT PUSH IT OFFSHORE OF SOCAL. OVER THE NEXT 2 DAYS THE FARTHER NORTHWEST ONE GOES IN THE CWFA THE LESS OF CHANCE FOR CONVECTION AS THE HIGH ALOFT WILL KEEP THE ATMOSPHERE MUCH MORE STABLE. FURTHER SOUTH THE COMBINATION OF THE VORTICITY FEATURE...INSTABILITY AND SUFFICIENT MOISTURE WILL KEEP THE POTENTIAL FOR THUNDERSTORMS AROUND. WHILE PWATS ARE FORECAST TO REMAIN OVER AN INCH OVER THE MOJAVE DESERT WHICH WILL SUPPORT HEAVY RAIN PRODUCING STORMS...WE WILL NOT ISSUE ANY FLASH FLOOD WATCHES FOR THURSDAY OR FRIDAY AT THIS TIME DUE TO UNCERTAINTIES IN JUST HOW ACTIVE IT WILL GET. TEMPS SHOULD BE A FEW DEGREES ABOVE NORMAL BUT MUCH WARMER THAN WHAT WE HAVE SEEN THE PAST FEW DAYS OVER THE MOJAVE DESERT. WELL ABOVE NORMAL TEMPS WILL CONTINUE OVER INYO AND ESMERALDA COUNTY. .LONG TERM...THE OLD VORTICITY FEATURE OFF OF SOCAL GETS CAUGHT UP IN A BROAD MID/UPPER LEVEL TROUGH OFF THE WEST COAST ON SATURDAY. IT APPEARS ENOUGH MOISTURE AND INSTABILITY REMAIN AROUND ON SATURDAY THAT THE POTENTIAL FOR THUNDERSTORMS WILL CONTINUE ESPECIALLY ACROSS THE NORTHERN HALF OF THE CWFA WHERE THE BEST INSTABILITY LOOKS TO SET UP. BY SATURDAY NIGHT INTO SUNDAY DRIER AND MORE STABLE AIR IS SHOWN TO WORK IN FROM THE SOUTH AS THE OFFSHORE TROUGH EDGES CLOSER TO THE COAST AND MOST OF THE EMBEDDED ENERGY WITHIN THE TROUGH STARTS TO LIFT ON NORTH. THUS SUNDAY MAY NOT BE QUITE AS ACTIVE FOR CONVECTION AND POPS SHOW A SLIGHT TREND DOWN THEN. BY MONDAY INTO NEXT WEDNESDAY THE TROUGH OFFSHORE STILL EXISTS AND RIDGING ALOFT SITS OVER THE FOUR CORNERS. THIS WOULD FAVOR A SOUTHWEST FLOW ALOFT ACROSS OUR AREA WHICH WOULD SPREAD DRIER AND STABLE AIR FURTHER EAST WITH TIME. I DID LOWER POPS AND DEWPOINTS IN THE WESTERN HALF OF THE AREA TO ACCOUNT FOR THIS HOWEVER MOIST AND UNSTABLE AIR IS SHOWN TO LINGER OVER MOHAVE COUNTY AND THIS PART OF THE AREA MAY NEVER REALLY DRY OUT. TEMPS SHOULD RISE BACK CLOSER TO NORMAL IN MOST AREAS AND MAY EVEN BE A FEW DEGREES ABOVE NORMAL ON MONDAY AND TUESDAY AS THINGS REALLY DRY OUT. I LEANED CLOSELY TO THE ECMWF MOS AND BIAS CORRECTED NUMBERS FOR HIGHS. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && $$ STACHELSKI HTTP://WEATHER.GOV/LASVEGAS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
345 AM EDT THU AUG 2 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THURSDAY THROUGH THE WEEKEND...ACCOMPANIED BY ISOLATED THUNDERSTORMS EACH DAY. A WEAK COLD FRONT WILL REACH THE AREA MONDAY AND MAY LINGER AS IT WEAKENS SLOWLY THROUGH MID WEEK AS HIGH PRESSURE BUILDS IN BEHIND IT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 315 AM THURSDAY...MID-LEVEL S/W TROFS OR IMPULSES ACROSS CENTRAL NC AND UPSTATE GEORGIA...WILL BOTH MAKE A BEE-LINE TO THE SE U.S. COAST THIS AFTERNOON AND NIGHT. THESE IMPULSES ARE CURRENTLY RESPONSIBLE FOR THE SMALL CLUSTER OF TSTMS AT THE MOMENT VIA LATEST AND ADJACENT 88-DS. MAY HAVE TO ADD CONVECTION FOR THIS MORNING ACROSS THE ILM NC SECTION OF THE CWA GIVEN LATEST EXTRAPOLATION AND HRRR MODEL OUTPUT. MODELS TAKE THE MID-LEVEL S/W TROF OFF THE SE NC COAST EARLY THIS EVENING...RESULTING WITH NVA AND SUBSIDENCE IN ITS WAKE FOR THE REMAINDER OF THU NIGHT. FOR THE TIME BEING WILL GO WITH 20 TO POSSIBLY 30 POPS TODAY...MAINLY IN THE VICINITY OF THE MID-LEVEL S/W TROF. FOR THE PAST SEVERAL DAYS IT HAS BEEN A TUG-OF-WAR BETWEEN NAM MOS AND GFS MOS GUIDANCE FOR THE ILM CWA. WILL LEAN TOWARD THE NAM MOS GUIDANCE FOR THE TIME BEING. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM THURSDAY...MID TO UPPER TROUGH LIFTS OFF AND WEAKENS AS IT GETS SQUEEZED OUT BY RIDGE BUILDING IN OVER THE SOUTHEAST FROM THE EAST AND WEST. HEIGHTS WILL BE RISING FROM NEAR 588 DM FRI MORNING UP TO 594 DM BY SAT EVENING WITH INCREASED SUBSIDENCE AND PLENTY OF DRYING THROUGH THE MID LEVELS OF THE ATMOSPHERE. LOOKS LIKE A VERY TYPICAL SUMMER TIME MOISTURE PROFILE WITH MOISTURE LOCKED IN BELOW H85 AND RH VALUES DROPPING OFF TO 40 PERCENT OR LESS FROM H7 UP THROUGH H3. PCP WATER VALUES WILL BE DOWN LESS THAN A HALF INCH AND WILL CREEP UP TO 1.75 BY END OF PERIOD. MORE OF A W-SW FLOW ON FRI WILL BACK AROUND TO THE S THROUGH THE LOWER LEVELS AS BERMUDA HIGH BUILDS BACK INTO AREA FROM THE EAST THROUGH SAT. THIS WILL ALLOW A DEEPER MOISTURE RETURN BY THE LATTER HALF OF THE WEEKEND. LIGHT SOUTHERLY RETURN FLOW WILL BE ENHANCED EACH AFTERNOON BY THE SEA BREEZE AS TEMPS RISE INTO THE 90S WITH PLENTY OF SUNSHINE. THIS SHOULD ALLOW FOR SOME LOW LEVEL INSTABILITY AND CONVERGENCE ENOUGH TO PRODUCE SOME CU WITH ONLY SLIGHT CHC OF CONVECTIVE DEVELOPMENT. OVERNIGHT LOWS WILL FALL INTO THE 70S. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 300 AM THURSDAY...MID TO UPPER RIDGE WILL BUILD OVER THE CENTRAL CONUS AS TROUGH PUSHES SYSTEM EAST THROUGH EARLY NEXT WEEK. A COLD FRONT WILL MAKE IT INTO THE MOUNTAINS BY SUNDAY NIGHT AND WILL GET PUSHED EAST AS H5 TROUGH DIGS DOWN THROUGH THE SOUTHEAST ON MONDAY. THEREFORE WILL SEE INCREASED COVERAGE OF SHWRS/TSTMS ON MONDAY. THIS FRONT MAY GET STALLED AND MAKE SLOW PROGRESS EAST THROUGH MID WEEK AS IT COMES UP AGAINST STRONG ATLANTIC RIDGE. IT LOOKS LIKE IT WILL WEAKEN OVER THE AREA MAKING LITTLE PROGRESS EAST AS WEAK HIGH PRESSURE BUILDS INTO THE CAROLINAS BEHIND IT. SHOULD KEEP MORE UNSETTLED WEATHER ESPECIALLY ALONG THE COAST TUES AND WED. OVERALL SUNDAY SHOULD SEE ONE LAST DAY OF WARMER TEMPS AND SUNSHINE ON SUNDAY WITH PCP CHC INCREASING SLIGHTLY BUT EXPECT MUCH MORE IN THE WAY OF CLOUDS AND PCP HEADING INTO MON AND TUES AND THEREFORE TEMPS SHOULD BE A FEW DEGREES LOWER. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 06Z...PROB OF VCSH AT FLO/LBT BY 08-10Z IS LOW BUT WILL CONT TO MENTION IN TAFS. BEST CHANCE SHOULD BE AT LBT. VFR CONDITIONS EXPECTED TO GIVE WAY TO MVFR VSBYS IN BR 08-12Z. LOW CONFIDENCE OF IFR...BUT IF IFR OCCURS IT MOST LIKELY WOULD OCCUR AT THE COASTAL TERMINALS. LGT/VRBL WINDS WILL BECOME LIGHT SW AFT SUNRISE. VCSH VCTS EXPECTED 14-19Z AT THE COASTAL TERMINALS AND AFT 18Z AT FLO/LBT. WINDS BECOME SOUTHEAST TO SOUTH BY EARLY AFTERNOON. EXPECT CONVECTION TO DIURNALLY DISSIPATE DURING THE EVENING. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM THURSDAY...BERMUDA HIGH PRESSURE SFC AND ALOFT WILL RIDGING WESTWARD TO THE SE U.S. COAST THROUGHOUT THE NEAR TERM. A COUPLE OF MID-LEVEL S/W TROFS WILL MOVE OFF THE MAINLAND THIS NEAR TERM AND RESULT IN A SOMEWHAT PINCHED SFC PG. WILL BE ADVERTISING SW WINDS AROUND 15 KT...OR JUST 10-15 KT. AS FOR SIG SEAS...A LOCALLY PRODUCED 2+ FOOT WIND WAVE COMBINED WITH A 1-2 FT ESE GROUND SWELL...WILL COMBINE TO PRODUCE SIG SEAS IN THE 2 TO 4 FT RANGE. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM THURSDAY...SOUTHERLY RETURN FLOW AROUND BERMUDA HIGH WILL CONTINUE THROUGH THE PERIOD. WINDS OVERALL WILL BE 10 KTS OR LESS BUT WILL SEE SOME GUSTINESS WITH SLIGHTLY HIGHER WINDS EACH AFTERNOON IN SEA BREEZE CLOSER TO SHORE. SEAS WILL REMAIN 2 TO 3 FT WITH A SLIGHTLY LONGER PERIOD EASTERLY SWELL MIXING IN WITH THE LOCALLY GENERATED WIND WAVE. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 300 AM THURSDAY...SOUTHERLY RETURN FLOW AROUND BERMUDA HIGH WILL INCREASE SLIGHTLY AS GRADIENT TIGHTENS LATE SUNDAY INTO MONDAY AS WEAK COLD FRONT MAKES ITS WAY INTO THE CAROLINAS. THEREFORE EXPECT WINDS TO PICK UP FROM AROUND 10 KTS ON SUNDAY TO A MORE SOLID 15 KTS THROUGH MONDAY AS FRONT NEARS THE WATERS. WNA ALSO SHOWING A LONGER PERIOD SE SWELL UP TO 12 SECONDS REACHING THE WATERS ON MONDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH SHORT TERM...RGZ LONG TERM...RGZ AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
400 AM CDT THU AUG 2 2012 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT 359 AM CDT THU AUG 2 2012 AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE 02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A 700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE. AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE NMM AND ARW ALSO SUPPORT THIS TOO. FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA. THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL PASSAGE. .LONG TERM...SUNDAY THROUGH THURSDAY 359 AM CDT THU AUG 2 2012 ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE FORECAST AREA. FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES. BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT WERE PRODUCED IN THE ALL BLEND. && .AVIATION... 1115 PM CDT WED AUG 1 2012 A WEST-EAST RUNNING FRONTAL BOUNDARY WILL CONTINUE TO SERVE AS THE FOCUS FOR SHRA/TS DEVELOPMENT OVERNIGHT...PERSISTING INTO THU MORNING. THERE IS STILL A SMALL THREAT FOR STRONG TO DAMAGING WIND GUSTS IN THE VICINITY OF ANY STORM THROUGH ABOUT 2 AM...BUT MOSTLY THIS POTENTIAL HAS LESSENED AS THE NEAR SFC STABILITY HAS INCREASED. DO EXPECT PERIODS OF SHRA/TS OVERNIGHT. THE SEVERAL HOURS OF RAIN COULD RESULT IN THE LOWERING OF CLOUD BASES...BUT WILL KEEP TAFS VFR FOR NOW. EXPECT THE RAIN TO EXIT EAST BY THE AFTERNOON. SHOULD BREAK OUT OF BKN MID LEVEL CIGS BY MID/LATE AFTERNOON. FOR WINDS... DIRECTION COULD BE HIGHLY VARIABLE AND RELATIVELY LIGHT AS THE FRONT LAYS ACROSS KRST/KLSE. THIS MAKES PINNING DOWN A PREVAILING DIRECTION A BIT DIFFICULT UNTIL THE FRONT SAGS SOUTH LATER THU AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... 359 AM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1150 PM CDT WED AUG 1 2012 .AVIATION/06Z TAFS/... OUTFLOW DRIVEN THUNDERSTORMS NORTH OF LA CROSSE EXPECTED TO WEAKEN AS THEY MOVE EAST...AND WILL REMAIN WELL NORTH OF TAF SITES OVERNIGHT. CHANCE OF THUNDER THURSDAY AFTERNOON ON NOSE OF 850 WARM AIR ADVECTION AND FRONTOGENETIC FORCING WITH WEAK COLD FRONT...BUT VERY DRY BELOW 10K FT SO CONFIDENCE LOW. WILL MENTION VCNTY FOR NOW. BOUNDARY LAYER IS STILL STIRRED SO NO FOG FORECAST BUT NEEDS TO BE WATCHED ESPECIALLY AT KENW. OTHERWISE VFR CONDITIONS EXPECTED THROUGH FORECAST PERIOD. && .PREV DISCUSSION... /ISSUED 325 PM CDT WED AUG 1 2012/ VERY SHORT TERM...TONIGHT AND THURSDAY. CURRENT ELEVATED CONVECTION ACROSS NORTHERN WISCONSIN ASSOCIATED WITH LOW LEVEL WARM AIR ADVECTION AND NOSE OF 30 KNOT PLUS WESTERLY LOW LEVEL JET. THIS CONVECTION SHOULD SHIFT SOUTHEAST TOWARD CENTRAL TO EAST CENTRAL WISCONSIN BUT WEAKEN...AS CAPPED AIRMASS LINGERS IN SOUTHERN WISCONSIN. THIS IS SUPPORTED BY 16Z RUN OF HRRR MODEL. MAY SEE SOME LEFTOVER DEBRIS CLOUDS MOVE THROUGH THE AREA LATER THIS AFTERNOON INTO THE EARLY EVENING. WILL GO DRY FOR NOW IN THE FAR NORTHERN COUNTIES THROUGH THE REST OF THE DAY. SURFACE COLD FRONT SHIFTS SOUTHEAST TOWARD THE AREA TONIGHT...THEN SLOWLY SOUTHWARD THROUGH THE AREA ON THURSDAY. WARM AIR ADVECTION CONTINUES AHEAD OF THE FRONT TONIGHT...WITH THE RIGHT REAR QUADRANT OF A 250MB JET STREAK PUSHING THROUGH LATER TONIGHT INTO THURSDAY MORNING. AREA FORECAST SOUNDINGS FROM NAM AND RAP SHOWING CAP FOR SURFACE BASED PARCELS TONIGHT AND THURSDAY...WITH MODEST ELEVATED CAPES AROUND 500 J/KG. LOW LEVELS REMAIN DRY...WITH SOME MID LEVEL MOISTURE MOVING INTO THE AREA LATER TONIGHT INTO THURSDAY. HRRR MODEL TRIES TO DEVELOP AN AREA OF CONVECTION IN SOUTHERN MINNESOTA ALONG COLD FRONT AND BRING IT TOWARD THE WESTERN COUNTIES AFTER MIDNIGHT TONIGHT. FOR NOW...WILL BRING IN CHANCE POPS FROM NORTHWEST TO SOUTHEAST TONIGHT. LINGERED CHANCE POPS THURSDAY MORNING IN THE NORTHERN COUNTIES...LOWER TO THE SOUTH...WITH LOWER END POPS DURING THE AFTERNOON. TEMPERATURES WILL BE TRICKY DEPENDING ON HOW MUCH MID LEVEL CLOUDINESS DEVELOPS/MOVES THROUGH THE AREA. WENT SOMEWHAT LOWER THAN WARM 925MB TEMPERATURES FROM NAM...UPPER 60S TONIGHT WITH UPPER 80S TO LOWER 90S THURSDAY. LAKE BREEZE IN THE AFTERNOON SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY. WEAK Q-VECTOR CONVERGENCE AND FRONTEGENETICAL FORCING MAY RESULT IN A FEW SHOWERS OR THUNDERSTORMS LINGERING INTO THURSDAY EVENING OVER THE NORTHERN AREAS. BOTH ECMWF AND NAM SHOW THIS WEAK FORCING...BUT WILL BE LIMITED BY DRYING MID LEVELS. SLIGHTLY BETTER FORCING FARTHER NORTH...SO WL ONLY GO WITH SCHC POPS FOR NOW. LOW LEVEL MIXING SHOULD PREVENT SIGNIFICANT FOG LATER THURSDAY NIGHT. SHORT WAVE RIDGING AHEAD OF NEXT WEATHER SYSTEM IS EXPECTED TO BRING A PLEASANT DAY FOR FRIDAY...WITH UNSETTLED CONDITIONS FOCUSED TO THE SOUTH AND WEST OF WI. SHORT TERM GUIDANCE IN SURPRISINGLY GOOD AGREEMENT ON MORE VIGOROUS SHORT WAVE TROF MOVING ACROSS SOUTHERN CANADA AND THE WESTERN GTLAKES FRIDAY NIGHT THROUGH SATURDAY NIGHT. ASSOCIATED LOW PRESSURE WILL DRAG A COLD FRONT ACROSS SOUTHERN WI AND LAKE MICHIGAN DURING PEAK HEATING OF THE AFTN AND EVE. WITH SFC DEWPTS LIKELY TO BE IN THE MID 60S TO LOW 70S...SFC BASED CAPE VALUES MAY CLIMB TO ABV 3000 J/KG. BULK SHEAR WILL BE STRONG ENOUGH...IN THE 25 TO 40KT RANGE. LOW LEVEL JETS REMAIN FOCUSED FARTHER SOUTH ALONG WARM FRONT AND NORTH...CLOSER TO LOW PRESSURE. HENCE WL KEEP POPS IN HIGH CHANCE CATEGORY INTO SAT NGT...AND MENTION POSSIBILITY OF SEVERE IN HAZARDOUS WEATHER OUTLOOK. LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. VIGOROUS SHORT WAVE TROUGH AND COLD FRONT PUSH EAST OF WISCONSIN SATURDAY NIGHT...USHERING COOLER AND DRY CONDITIONS INTO THE REGION FOR SUNDAY AND MONDAY. GFS ENSEMBLES IN FAIRLY GOOD AGREEMENT ON THIS SCENARIO. EXTENDED OUTLOOK TURNS MORE MURKY HEADING INTO MID-WEEK AS BOTH ECMWF AND GFS HAVE BEEN FLIP-FLOPPING ON UPPER LEVEL STEERING FLOW. LATEST SOLUTIONS HAVE TRENDED TOWARD MORE PROGRESSIVE WEST-NORTHWEST STEERING FLOW FOR THE LATER HALF OF THE PERIOD. UKMT...GFS AND ECMWF SOLUTIONS CARRY WEAK FRONTAL BOUNDARY THROUGH WI SOMETIME IN THE MON NGT/TUESDAY TIME FRAME...WITH FRONT POSSIBLY BECOMING STATIONARY ACROSS THE REGION...BUT CONFIDENCE LOW AS EXTENDED GUIDANCE HAVING ISSUES WITH TIMING AND STRENGTH OF SHORT WAVE TROFFING MOVING INTO WESTERN CONUS. AFTER COOLER...MORE SEASONAL PERIOD ON SUNDAY AND MONDAY...85H TEMPS WARM BACK TO AROUND 20C. GFS 5DAY ANOMOLIES SHOW RIDGING AND WARMER TEMPERATURES EXPANDING BACK INTO THE UPPER MIDWEST LATER NEXT WEEK AHEAD OF LONG WAVE TROUGH AMPLIFICATION IN THE EASTERN PAC/NORTHWEST CONUS. AVIATION /00Z TAFS/...VFR CONDITIONS EXPECTED THROUGH THURSDAY ACROSS TAF SITES. FEW TO SCATTERED DIURNAL CUMULUS AT EASTERN TAF SITES SHOULD DISSIPATE BY SUNSET. LIGHT SOUTH TO SOUTHWEST WINDS EXPECTED AT MADISON DURING THIS TIME...WITH LIGHT SOUTHEAST WINDS EVENTUALLY REACHING MILWAUKEE AND KENOSHA BY 22Z TO 23Z WEDNESDAY. SOME MID LEVEL CLOUDS FROM STORMS TO THE NORTH MAY SHIFT THROUGH TAF SITES LATE THIS AFTERNOON AND EARLY THIS EVENING. SCATTERED TO BROKEN MIDDLE TO HIGH CLOUDS SHOULD GRADUALLY MOVE INTO THE AREA LATER TONIGHT AND THURSDAY. COLD FRONT WILL SHIFT SOUTHEAST TOWARD TAF SITES LATE TONIGHT...THEN SLIDES SOUTHWARD THROUGH TAF SITES THURSDAY. MAY SEE SHOWERS AND STORMS APPROACH MADISON BETWEEN 06Z AND 12Z THURSDAY...AND ACROSS ALL SITES THURSDAY. HOWEVER...WILL HOLD OFF MENTION IN TAFS FOR NOW DUE TO LOW CONFIDENCE IN AREAL COVERAGE AND TIMING. LIGHT WINDS WILL SHIFT TO THE NORTHEAST/EAST IN THE WAKE OF THE COLD FRONT IN THE LATE MORNING AND EARLY AFTERNOON THURSDAY. CONFIDENCE... TONIGHT AND THURSDAY...MEDIUM THURSDAY NIGHT...LOW TO MEDIUM. FRIDAY AND FRIDAY NIGHT...MEDIUM. SATURDAY AND SATURDAY NIGHT...MEDIUM. SUNDAY AND MONDAY...MEDIUM TO HIGH. TUESDAY AND WEDNESDAY...LOW. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...REM TONIGHT/THURSDAY AND AVIATION/MARINE...WOOD THURSDAY NIGHT THROUGH WEDNESDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1115 PM CDT WED AUG 1 2012 .SHORT TERM...TONIGHT 615 PM CDT WED AUG 1 2012 WATCHING EVOLUTION OF THUNDERSTORMS ASSOCIATED WITH ELEVATED INSTABILITY AND SFC FRONT/ELEVATED FRONTOGENETIC FORCING ACROSS SOUTHWEST MN. THIS WEST-EAST RUNNING BOUNDARY WILL HOVER ACROSS SOUTHEAST MN-WESTERN WI OVERNIGHT...STAYING A FOCUS FOR SHOWER/STORM DEVELOPMENT. MAIN CONCERN THOUGH IS THE SEVERE POTENTIAL THIS EVENING. STRONG INSTABILITY WITH MLCAPES NEAR 4K J/KG OVER SOUTHERN MN PER RAP ANALYSIS AT 22Z. SHEAR ISN/T TOO IMPRESSIVE...BUT ABOUT 20-25 KTS EFFECTIVE SHEAR. THE INSTABILITY WOULD SUPPORT STRONG UPDRAFTS AND A LARGE HAIL THREAT. PERHAPS MORE SIGNIFICANTLY IS THE DEEP DRY SUB CLOUD LAYER. BUFKIT SOUNDINGS CONTINUE TO INDICATE THIS...WITH DCAPES OVER 1500 J/KG PROGGED FOR THE FORECAST AREA THIS EVENING. THIS ENHANCES THE DAMAGING WIND THREAT. ANY STRONG STORM WOULD BE CAPABLE OF PRODUCING 40 MPH GUSTS...OBVIOUSLY MORE WITH A SEVERE STORM. SEVERE THUNDERSTORM WATCH BUTTING UP AGAINST THE WESTERN FORECAST AREA...AND IF STORMS CONTINUE TO EVOLVE...WOULD EXPECT ANOTHER WATCH FOR SOUTHEAST MN INTO WESTERN WISCONSIN BY MID EVENING. .LONG TERM...SUNDAY THROUGH WEDNESDAY 309 PM CDT WED AUG 1 2012 MEDIUM RANGE MODEL RUNS OF 01.00Z IN RATHER GOOD AGREEMENT WITH THE TROUGH MOVING EAST OF THE REGION AND WEAK SHORTWAVE RIDGING BUILDING INTO THE UPPER MIDWEST. MODELS STAY IN PRETTY GOOD AGREEMENT MON-WED AS THE SHORTWAVE RIDGING QUICKLY MOVES EAST OF THE AREA MON AND THE NEXT AND THE NEXT STRONGER TROUGH MOVES ACROSS SOUTHERN CAN/NORTHERN CONUS...INTO THE UPPER MIDWEST TUE/WED. SOME DIFFERENCE OF TIMING/ STRENGTH DETAILS OF SHORTWAVES IN THE FLOW BY TUE/WED BUT THIS TO BE EXPECTED. BETWEEN MODEL CONSISTENCY GOOD BUT RUN-TO-RUN CONSISTENCY LESS THAN DESIRABLE...ESPECIALLY BY TUE/WED. LONG-TERM FCST CONFIDENCE GOOD SUN THEN AVERAGE MON-WED UNTIL THE DETAIL CONSENSUS IMPROVES. WITH THE TROUGH/LOW EXITING EAST...DRIER/COOLER CAN HIGH PRESSURE SETTLES ACROSS THE REGION FOR SUN/MON. TEMPS LOOKING TO BE BELOW NORMAL SUN...THEN ALREADY MODERATE ON MON AS THE CENTER OF THE HIGH MOVES EAST AND SOUTHERLY FLOW RETURNS. MID LEVEL TROUGH MOVING EAST ALONG THE US/CAN BORDER TUE/WED DRAGS A SFC TROUGH/FRONT INTO/ ACROSS THE AREA TUE. AGAIN TIMING/DETAIL DIFFERENCES ON MOISTURE/ INSTABILITY AND FORCING/LIFT BY TUE. BOUNDARY LOOKS TO STALL IN THE REGION WED WITH STRENGTHENING LOW PRESSURE IN THE CENTRAL/NORTHERN PLAINS AS MORE SHORTWAVE ENERGY COMES THRU THE ROCKIES OR DROPS INTO THE NORTHERN PLAINS. SMALL SHRA/TSRA CHANCES TUE/WED LOOK REASONABLE AT THIS POINT. WITH CONTINUED SOUTHERLY/INCREASING MOISTURE...TEMPS CLIMB BACK TO ABOVE NORMAL FOR TUE/WED. MODEL CONSENSUS DATA SET IN FCST GRIDS FOR DAYS 4-7 HAVE THIS WELL TRENDED. && .AVIATION... 1115 PM CDT WED AUG 1 2012 A WEST-EAST RUNNING FRONTAL BOUNDARY WILL CONTINUE TO SERVE AS THE FOCUS FOR SHRA/TS DEVELOPMENT OVERNIGHT...PERSISTING INTO THU MORNING. THERE IS STILL A SMALL THREAT FOR STRONG TO DAMAGING WIND GUSTS IN THE VICINITY OF ANY STORM THROUGH ABOUT 2 AM...BUT MOSTLY THIS POTENTIAL HAS LESSENED AS THE NEAR SFC STABILITY HAS INCREASED. DO EXPECT PERIODS OF SHRA/TS OVERNIGHT. THE SEVERAL HOURS OF RAIN COULD RESULT IN THE LOWERING OF CLOUD BASES...BUT WILL KEEP TAFS VFR FOR NOW. EXPECT THE RAIN TO EXIT EAST BY THE AFTERNOON. SHOULD BREAK OUT OF BKN MID LEVEL CIGS BY MID/LATE AFTERNOON. FOR WINDS... DIRECTION COULD BE HIGHLY VARIABLE AND RELATIVELY LIGHT AS THE FRONT LAYS ACROSS KRST/KLSE. THIS MAKES PINNING DOWN A PREVAILING DIRECTION A BIT DIFFICULT UNTIL THE FRONT SAGS SOUTH LATER THU AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... 309 PM CDT WED AUG 1 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RIECK LONG TERM....RRS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1045 AM EDT THU AUG 2 2012 .UPDATE... 14Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW THE SOUTHEASTERN CONUS AND EASTERN GULF UNDERNEATH A SUBTLE HEIGHT WEAKNESS BETWEEN A DOMINANT UPPER RIDGE OVER THE SOUTHERN PLAINS AND ANOTHER RIDGE OVER CUBA/BAHAMAS. AT THE SURFACE...SUBTROPICAL RIDGE AXIS EXTENDS ACROSS THE SOUTH-CENTRAL FLORIDA PENINSULA PROVIDING A LIGHT LOW LEVEL FLOW OUT OF THE SW TO THE MAJORITY OF THE FORECAST AREA. THE FAVORED SW FLOW FOR NOCTURNAL MARINE SHOWERS COMBINED WITH THE SYNOPTIC SUPPORT ASSOCIATED WITH THE WEAKNESS ALOFT PROVIDED THE FORCING FOR SCT-NMRS CONVECTION OVER THE NORTHERN COASTAL WATERS THIS MORNING. IN THE NEXT FEW HOURS...WILL LIKELY SEE A DECREASE IN THE COVERAGE OF CONVECTION OVER THE COASTAL WATERS AS THE SEA-BREEZE TRANSLATES THE BEST LOW LEVEL CONVERGENCE ONSHORE. ALREADY BEGINNING TO SEE THE FIRST STAGE OF SHOWERS DEVELOPING ALONG THE NATURE COAST AND SHOULD SEE THIS SCT ACTIVITY EXPAND DOWN INTO THE TAMPA BAY AREA AND SOUTHWARD BY NOON. SIMILAR TO WEDNESDAY...THE BEST CHANCES FOR SHOWERS ALONG THE COASTAL ZONES WILL BE THROUGH EARLY AFTERNOON WITH CONVECTION PUSHING FURTHER INLAND WITH THE SEA-BREEZE BY THE LATER AFTERNOON HOURS. WILL NOT COMPLETELY REMOVE POPS CLOSE TO THE COAST LATER TODAY...BUT WILL TRANSLATE WORDING FROM SCATTERED TO ISOLATED. PLENTY OF MORNING INSOLATION HAS ALLOWED TEMPERATURES TO QUICKLY REBOUND INTO THE MIDDLE AND UPPER 80S. SHOULD HAVE LITTLE TROUBLE REACHING THE LOWER 90S INLAND AND UPPER 80S TO AROUND 90 AT THE COAST FOR LOCATIONS WHICH AVOID SIGNIFICANT SHOWER ACTIVITY. CURRENT TEMPERATURE/DEWPOINT GRIDS ARE IN GOOD SHAPE AND WILL NOT BE MAKING ANY SIGNIFICANT CHANGES THROUGH THE EVENING HOURS. && .PREVIOUS (FRIDAY - SATURDAY)... PERSISTENT MID LEVEL TROUGH OVER THE EASTERN U.S EXTENDING SOUTH INTO THE NORTHERN GULF WILL WEAKEN DURING THE SHORT TERM PERIOD AS THE SUBTROPICAL RIDGE FROM THE WESTERN ATLANTIC WEST ACROSS THE SOUTHERN PENINSULA SHIFTS NORTH FRIDAY INTO THE UPCOMING WEEKEND. AS FOR TODAY MODELS DEPICT SLIGHTLY DRIER AIR MOVING INTO WEST CENTRAL AND SOUTHWEST FLORID ASSOCIATED WITH THE RIDGE. THIS DRY AIR SHOULD RESULT IN LOWER STORM COVERAGE WITH POPS IN THE 20 TO 30 PERCENT RANGE FROM THE COAST TO INTERIOR LOCATIONS WHICH IS DEPICTED WELL BY THE MAV AND NAM POP GUIDANCE. THE SURFACE RIDGE AXIS WILL LIFT NORTH TO THE CENTRAL PENINSULA ON FRIDAY. A SLOW INCREASE IN MOISTURE WILL LEAD TO HIGHER COVERAGE OF SCATTERED SHOWERS AND STORMS ALONG THE EAST AND WEST COAST SEA BREEZE BOUNDARIES WITH HIGHEST POPS (40 PERCENT) EXPECTED TO SET UP OVER INLAND LOCATIONS ALONG THE SEA BREEZE MERGER DURING THE AFTERNOON HOURS...WITH 30 PERCENT POPS ALONG THE COAST. DURING FRIDAY NIGHT INTO SATURDAY DEEPER MOISTURE (PW`S INCREASING TOWARD 2 INCHES) WILL OVERSPREAD THE REGION FROM THE SOUTHEAST AHEAD OF A TROPICAL WAVE WHICH IS FORECAST TO MOVE ACROSS THE SOUTH CENTRAL PENINSULA DURING SATURDAY AND SATURDAY NIGHT. THIS MOISTURE WILL LEAD TO EVEN HIGHER CHANCES (POPS 30 TO 50 PERCENT RANGE) FOR SHOWERS AND STORMS ALONG WITH SOME LOCALLY HEAVY RAINFALL AS THE WAVE AFFECTS THE REGION. TEMPERATURES WILL CONTINUE TO RUN A FEW DEGREES ABOVE NORMAL WITH DAYTIME HIGHS CLIMBING INTO THE LOWER AND MID 90S WITH NIGHTTIME LOWS IN THE LOWER 70S NORTH AND MID TO UPPER 70S CENTRAL AND SOUTH. && .AVIATION... SOME SMALL SHOWERS MOVING IN FROM THE GULF COULD BRING BRIEF MVFR CEILINGS AT TPA...PIE AND SRQ THROUGH 14 OR 15Z. MAIN ACTIVITY WILL BE INLAND THIS AFTERNOON WITH LAL THE MOST LIKELY TO SEE IMPACTS. && .MARINE... SURFACE HIGH PRESSURE ACROSS THE SOUTHERN PENINSULA TODAY WILL MAINTAIN A SOUTHWEST TO WEST WIND FLOW AT 10 KNOTS OR LESS ALONG WITH SEAS OF 2 FEET OR LESS. DURING FRIDAY AND INTO THE UPCOMING WEEKEND THE SURFACE RIDGE AXIS WILL SHIFT NORTH TO THE NORTH CENTRAL PENINSULA WITH WINDS BACKING TO THE SOUTHEAST AND EAST...WITH A WEAK PRESSURE PATTERN SUPPORTING AN ENHANCED ONSHORE SEA BREEZE COMPONENT DEVELOPING ALONG THE COAST EACH AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... TPA 92 76 92 78 / 30 20 30 10 FMY 94 76 93 76 / 30 20 30 10 GIF 95 76 95 76 / 30 20 40 20 SRQ 91 76 92 75 / 30 20 30 10 BKV 93 70 93 72 / 30 20 30 10 SPG 91 80 91 79 / 30 20 30 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE...MROCZKA AVIATION...JILLSON PREVIOUS DISCUSSION...MCMICHAEL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
630 AM EDT THU AUG 2 2012 .SYNOPSIS... A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY AND SUNDAY INCREASING THE CHANCES FOR RAINFALL. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .THIS MORNING...A SMALL AREA OF SHOWERS WERE AFFECTING THE CSRA. INCLUDED A 30-40 PERCENT CHANCE FOR 3-4 HOURS THIS MORNING. THIS ACTIVITY IS ASSOCIATED WITH A WEAK SHORT WAVE WHICH ACCORDING TO THE RUC13 MODEL SHOULD HAVE MOVED TO THE EAST BY 13Z. ELSEWHERE LESS THAN 10 PERCENT. WILL CONTINUE TO MENTION PATCHY FOG SOUTHEAST PART OF CWA WHERE SURFACE DEWPOINTS ARE A BIT HIGHER. .TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44 PERCENT. SO WENT 20 PERCENT. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20 PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S. FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE 90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY. THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S. OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... POTENTIAL FOR MAINLY MVFR VSBYS EARLY THIS MORNING...OTHERWISE VFR CONDITIONS EXPECTED. UPPER SHORT WAVE IS COMING THROUGH THIS MORNING AND WILL PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION POSSIBLE THIS MORNING...THEN IT APPEARS THAT MOST CONVECTIVE COVERAGE THIS AFTERNOON WILL BE CONFINED TO THE SE FA AND COASTAL PLAIN. CONFIDENCE/COVERAGE OF TS NOT SUFFICIENT TO INCLUDE IN THE TAFS AT THIS TIME. CONVECTIVE ANALYSIS INDICATES STRONG INSTABILITIES FOR THIS AFTERNOON...SO ANYTHING THAT DOES DEVELOP THIS AFTN/EVE WILL HAVE THE POTENTIAL TO BE STRONG TO SEVERE. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
607 AM EDT THU AUG 2 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THE WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE EVOLUTION OF AFTERNOON CONVECTION WILL MIRROR A TYPICAL MID- LATE SUMMER CONVECTIVE PATTERN TODAY WHERE OUTFLOW BOUNDARIES GENERATED BY ISOLATED SEA BREEZE TSTMS EVENTUALLY INTERSECT OUTFLOWS GENERATED BY UPSTREAM CONVECTION TO SPARK SCATTERED CONVECTIVE CLUSTERS ACROSS INLAND AREAS. THE NAM/S SOLUTION SHOWING SOME SHORT OF MESOSCALE CONVECTIVE SYSTEM /MCS/ PLOWING THROUGH SOUTHEAST GEORGIA LOOKS SOMEWHAT SPURIOUS AND IS NOT SUPPORTED BY ANY OF THE OTHER VARIOUS MESOSCALE OR GLOBAL MODELS ATTM. WILL MAINTAIN A 20-30 PERCENT POPS REGIME WITH THE HIGHEST GRIDDED POPS CENTERED ROUGHLY ALONG AND WEST OF THE I-95 CORRIDOR. HIGHER SHORT-TERM POPS MAY EVENTUALLY BE NEEDED LATER TODAY... ESPECIALLY IF MESOSCALE PROCESSES TAKE HOLD...BUT THIS IS NEARLY IMPOSSIBLE TO PIN DOWN THIS FAR OUT. HIGHS WILL RANGE FROM THE MID 90S INLAND TO THE MID 80S AT THE BEACHES. MODIFIED RAP BUFR SOUNDINGS SHOW DCAPES RISING TO NEAR 1300 J/KG BY EARLY AFTERNOON WITH TOTAL TOTALS NEARING 55 UNITS AND SHOWALTER INDICES DROPPING TO NEAR -3C. THIS COUPLED WITH DELTA EPT/S APPROACHING +30C SUGGEST THERE WILL BE A SLIGHTLY HIGHER RISK FOR DAMAGING WINDS WITH THE STRONGER TSTMS TODAY. THE RISK FOR PULSE SEVERE TSTMS WILL BE HIGHEST NEAR MESOSCALE BOUNDARY INTERACTIONS WITHIN A WEAK 0-6KM BULK SHEAR REGIME. A MENTION FOR ISOLATED SEVERE TSTMS WILL BE PLACED IN THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... ANY LINGERING CONVECTION WILL DIMINISH BY MID-EVENING AS INSOLATION WANES AND THE SEA BREEZE CLEARS THE WESTERN ZONES. EXPECT A DRY NIGHT TO PREVAIL...ALTHOUGH AN ISOLATED SHOWER/TSTM COULD POPS JUST ABOUT ANYWHERE WITH RESIDUAL OUTFLOWS LIKELY LURKING ABOUT. DEBRIS CLOUDINESS WILL THIN WITH MOSTLY CLEAR SKIES DOMINATING FOR MUCH OF THE OVERNIGHT PERIOD. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO AROUND 80 AT THE BEACHES. THE FORECAST AREA WILL BECOME POSITIONED BETWEEN A SURFACE HIGH PRESSURE TO THE WEST AND A SUBTROPICAL HIGH PRESSURE TO THE EAST. HEIGHTS WILL CONTINUE TO INCREASE THROUGH THE WEEKEND WITH MODEST UPPER LEVEL RIDGING BUILDING ALONG THE EAST COAST. A PERSISTENT SOUTHERLY FLOW WILL ALLOW PLENTY OF DEEP MOISTURE TO CONTINUOUSLY ADVECT OVER THE AREA. MODEL SOUNDINGS VERIFY THIS DEEP MOISTURE WITH PWATS REMAINING STEADY AROUND 2 INCHES THROUGH THE WEEKEND. THUS...EXPECT ISOLATED TO SCATTERED CONVECTION TO DEVELOP FAIRLY EASILY EACH AFTERNOON AS THE SEA BREEZE PROPAGATES INLAND AND CONVECTIVE TEMPERATURES ARE REACHED. WITH HIGH TEMPERATURES EXPECTED TO REACH THE LOW TO MID 90S EACH AFTERNOON...CONVECTIVE TEMPS IN THE UPPER 80S WILL NOT BE DIFFICULT TO EXCEED. STILL...INSTABILITY PARAMETERS ARE LESS THAN IMPRESSIVE WITH SHOWALTER INDICES GENERALLY POSITIVE AND LAPSE RATES BETWEEN 5 AND 6 C/KM. THEREFORE...THE SEVERE POTENTIAL APPEARS LOW...BUT CAN NOT RULE OUT ONE OR TWO ISOLATED STRONG TO SEVERE STORMS. ANY STRONG STORMS WILL LIKELY DEMONSTRATE TRADITIONAL SUMMERTIME PULSE CHARACTERISTICS. ANY LINGERING CONVECTION WILL QUICKLY DIMINISH AFTER SUNSET...WITH OVERNIGHT LOWS EXPECTED TO REMAIN QUITE MILD IN THE MID TO LOW 70S INLAND AND UPPER 70S ALONG THE BEACHES. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... MODELS SHOW SUBTLE HIGH FALLS AT THE BEGINNING OF THE PERIOD AS A LOW PRESSURE SYSTEM MOVES EASTWARD ACROSS THE NEW ENGLAND AREA. ITS ASSOCIATED COLD FRONT WILL LIKELY STALL OUT WELL NORTH OF THE AREA SOMETIME AROUND MID WEEK. MEANWHILE...THE UPPER RIDGE ACROSS CENTRAL UNITED STATES WILL CONTINUE TO STRENGTHEN THROUGH THE PERIOD. AT THE SURFACE...THE FORECAST AREA WILL REMAIN SANDWICHED BETWEEN THE SURFACE HIGH PRESSURE OVER THE MIDDLE OF THE UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. THIS PATTERN COULD ALLOW FOR AN INCREASE IN CONVECTION...ESPECIALLY AS CONVECTION DEVELOPS ALONG THE STALLED FRONT AND INTERACTS WITH OTHER BOUNDARIES...LIKE THE SEA BREEZE. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS WITH LOW TO MID 90S EXPECTED DURING THE AFTERNOON AND DIPPING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. LOW PROBABILITIES FOR TSTMS THIS AFTERNOON AT BOTH TERMINALS. EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS POSSIBLE THURSDAY AFTERNOON/EVENING WITH SHOWERS/THUNDERSTORMS. && .MARINE... A BROAD SOUTHERLY FLOW REGIME WILL REMAIN IN TACT ACROSS THE WATERS THROUGH TONIGHT. WINDS WILL REMAIN 10-15 KT WITH SEAS 2-4 FT. ATLANTIC HIGH PRESSURE WILL PREVAIL ACROSS THE MARINE AREA THROUGH EARLY NEXT WEEK. THIS PATTERN WILL CONTINUE TO RESULT IN CONDITIONS BELOW SMALL CRAFT CRITERIA. IN GENERAL...SOUTH/SOUTHWEST WINDS BETWEEN 10 TO 15 KNOTS WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE WITH BRIEF INCREASES OF 15 TO 20 KNOTS...MAINLY DURING NOCTURNAL SURGING. SEAS WILL ALSO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH THE PERIOD...BUT EXPECT BRIEF INCREASES DURING TIMES OF STRONGER WINDS. GENERALLY...SEAS WILL REMAIN 2 TO 3 FEET WITHIN 20 NM AND NO MORE THAN 5 FEET FURTHER OUT. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...
AREA FORECAST DISCUSSION
NWS WICHITA KS
800 AM CDT THU AUG 2 2012 .UPDATE... WITH THE -SHRA & -TSRA HAVING VACATED CNTRL & SE KS HAVE UPDATED ALL AFFECTED PRODUCTS TO REMOVE THE MORNING MENTION OF THIS ACTIVITY. && .PREV DISCUSSION... /ISSUED 653 AM CDT THU AUG 2 2012/ AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10 TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING & ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED ATTENTION WITH 00Z & 06Z TAF ISSUANCES. PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/ DISCUSSION... TODAY-TONIGHT: ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400. CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH IT. FRI-FRI NIGHT: HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW... COULD BE EVEN WARMER THAN FORECAST. SAT-SUN: GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD. LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT... WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN SECTIONS. MON-WED: CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH. INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED. WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD. -HOWERTON AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 107 78 104 78 / 20 20 10 10 HUTCHINSON 104 76 103 76 / 20 20 10 10 NEWTON 103 77 102 77 / 20 20 10 10 ELDORADO 104 77 104 77 / 20 20 10 10 WINFIELD-KWLD 111 80 106 80 / 20 20 10 10 RUSSELL 99 73 101 73 / 20 30 10 20 GREAT BEND 101 74 102 74 / 20 20 10 20 SALINA 99 76 102 75 / 20 30 10 20 MCPHERSON 102 75 103 75 / 20 30 10 20 COFFEYVILLE 110 79 106 79 / 20 20 10 10 CHANUTE 105 76 103 78 / 20 20 10 10 IOLA 103 77 102 77 / 20 20 10 10 PARSONS-KPPF 107 77 104 79 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING FOR KSZ069-082-083-091>094-098>100. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
654 AM CDT THU AUG 2 2012 ...UPDATE TO AVIATION... .DISCUSSION... ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH. THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY. NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT AN ADVISORY. FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST. MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY. FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS. WOLTERS && .AVIATION... LINGERING CONVECTION ON THE SOUTH SIDE OF MCV OVER THE NORTHERN CWA WILL KEEP BKN AREA OF CONVECTION IN THE KTOP/KFOE SITES THROUGH 13Z...THEN GRADUALLY ENDING....ALTHOUGH GUSTY NORTH WINDS WILL PERSIST UNTIL 14Z-16Z TIME FRAME. MAIN AREA OF CONVECTION SHOULD BE EAST OF THE KMHK SITE BY 12Z BUT SHOWERS LINGERING THROUGH 13Z BEFORE ENDING. MVFR/BRIEF IFR VSBYS POSSIBLE IN ANY THUNDERSTORMS UNTIL 13Z...BUT CIGS SHOULD GENERALLY BE VFR. FOLLOWING CONVECTION THIS MORNING...REMAINDER OF THE TAFS WILL BE VFR AND DRY...ALTHOUGH MORE CONVECTION CANNOT BE RULED OUT AFTER 06Z TONIGHT...BUT CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS AT THIS POINT. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
653 AM CDT THU AUG 2 2012 .AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10 TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING & ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED ATTENTION WITH 00Z & 06Z TAF ISSUANCES. && .PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/ DISCUSSION... TODAY-TONIGHT: ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400. CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH IT. FRI-FRI NIGHT: HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW... COULD BE EVEN WARMER THAN FORECAST. SAT-SUN: GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD. LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT... WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN SECTIONS. MON-WED: CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH. INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED. WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD. -HOWERTON AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 107 78 104 78 / 20 20 10 10 HUTCHINSON 104 76 103 76 / 20 20 10 10 NEWTON 103 77 102 77 / 20 20 10 10 ELDORADO 104 77 104 77 / 20 20 10 10 WINFIELD-KWLD 111 80 106 80 / 20 20 10 10 RUSSELL 99 73 101 73 / 20 30 10 20 GREAT BEND 101 74 102 74 / 20 20 10 20 SALINA 99 76 102 75 / 20 30 10 20 MCPHERSON 102 75 103 75 / 20 30 10 20 COFFEYVILLE 110 79 106 79 / 20 20 10 10 CHANUTE 105 76 103 78 / 20 20 10 10 IOLA 103 77 102 77 / 20 20 10 10 PARSONS-KPPF 107 77 104 79 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING FOR KSZ069-082-083-091>094-098>100. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 AM EDT THU AUG 2 2012 .UPDATE... ISSUED AT 1057 AM EDT THU AUG 2 2012 HAVE LOWERED CLOUD COVER FOR TODAY TO GIVE A SUNNY FORECAST OVERALL. WHAT CUMULUS THAT DO POP UP SHOULD BE LIMITED AND MAINLY IN THE FAR SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. HAVE ALSO ADDED A BIT OF THE TYPICAL LATE SUMMER VALLEY FOG FOR LATE TONIGHT. THE NAM IS ALSO ADVECTING ELEVATED INSTABILITY INTO OUR SW COUNTIES OVERNIGHT ON ISENTROPIC LIFT. ALTHOUGH IT IS NOT AS PRONOUNCED IN THE GFS...IT IS PERSISTENT NOW IN THE NAM...AND HAVE ADDED A SLIGHT CHANCE POP FOR THIS. UPDATE ISSUED AT 700 AM EDT THU AUG 2 2012 A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS. LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON. HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP THE ZONES TO REMOVE THE PRE FIRST PERIOD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 340 AM EDT THU AUG 2 2012 SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY... INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE. OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON. CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION TODAY. GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY. TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID 90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH. THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE MOMENT AND MENTION BOTH IN THE HWO. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 AM EDT THU AUG 2 2012 THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS THE SETTING SUN WILL STABALIZE THE AIR MASS AND FINALLY GIVE THE AREA A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND LOWER 90S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 700 AM EDT THU AUG 2 2012 MVFR FOG IS AFFECTING SOME OF THE TERMINALS EARLY THIS MORNING WITH SITES SUCH AS KLOZ...KEKQ...AND K1A6 LIKELY TO SEE IFR BEFORE THE FOG BEGINS TO LIFT AND MIX OUT BY 13Z. CLR SKIES THIS MORNING MAY GIVE WAY TO SCT CU THIS AFTERNOON BEFORE CIGS BEGIN TO INCREASE LATE TONIGHT AS A DISTURBANCE CURRENTLY OVER THE CENTRAL PLAINS APPROACHES THE TN VALLEY. HOWEVER...CIGS ARE EXPECTED TO REMAIN AOA 5KFT AND...ONCE THE FOG LIFTS THIS MORNING...VFR AND LIGHT WINDS SHOULD BE THE RULE THROUGH THE REMAINDER OF THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...MB LONG TERM....DUSTY AVIATION...MB
AREA FORECAST DISCUSSION
NWS JACKSON KY
700 AM EDT THU AUG 2 2012 .UPDATE... ISSUED AT 700 AM EDT THU AUG 2 2012 A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS. LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON. HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP THE ZONES TO REMOVE THE PRE FIRST PERIOD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 340 AM EDT THU AUG 2 2012 SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY... INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE. OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON. CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION TODAY. GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY. TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID 90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH. THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE MOMENT AND MENTION BOTH IN THE HWO. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 AM EDT THU AUG 2 2012 THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS THE SETTING SUN WILL STABALIZE THE AIR MASS AND FINALLY GIVE THE AREA A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND LOWER 90S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 700 AM EDT THU AUG 2 2012 MVFR FOG IS AFFECTING SOME OF THE TERMINALS EARLY THIS MORNING WITH SITES SUCH AS KLOZ...KEKQ...AND K1A6 LIKELY TO SEE IFR BEFORE THE FOG BEGINS TO LIFT AND MIX OUT BY 13Z. CLR SKIES THIS MORNING MAY GIVE WAY TO SCT CU THIS AFTERNOON BEFORE CIGS BEGIN TO INCREASE LATE TONIGHT AS A DISTURBANCE CURRENTLY OVER THE CENTRAL PLAINS APPROACHES THE TN VALLEY. HOWEVER...CIGS ARE EXPECTED TO REMAIN AOA 5KFT AND...ONCE THE FOG LIFTS THIS MORNING...VFR AND LIGHT WINDS SHOULD BE THE RULE THROUGH THE REMAINDER OF THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MB SHORT TERM...MB LONG TERM....DUSTY AVIATION...MB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
941 AM EDT THU AUG 2 2012 .SYNOPSIS... A WEAKENING COLD FRONT WILL CROSS THE REGION THIS AFTERNOON. ANOTHER COLD FRONT WILL CROSS THE AREA ON FRIDAY. HIGH PRESSURE WILL RETURN FOR SATURDAY WITH PLEASANTLY WARM BUT LESS HUMID AIR. WARMER AND MORE HUMID CONDITIONS RETURN ON SUNDAY AHEAD OF ANOTHER COLD FRONT EXPECTED TO CROSS THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE: NEEDED TO BOOST DEWPOINTS UP THROUGHOUT THE CWA BRINGING THEM INTO THE MID AND UPPER 60S BY THE AFTERNOON. LATEST SATL VISIBLE IMAGERY SHOWED STRATUS AND FOG BEGINNING TO ERODE THANKS TO DAYTIME HEATING. CLEARING ACROSS THE WEST AND NORTHWEST HAS LED TO TEMPERATURES RISING INTO THE LOWER 70S. THEREFORE, AFTERNOON HIGHS WERE RAISED AS WELL AS THIS CLEARING WILL WORK EAST ALLOWING FOR MORE SUNSHINE. DECIDED TO BRING MAXES UP TO AOA 80F ACROSS THE NORTHERN AND CENTRAL AREAS WHILE DOWNEAST AND THE COAST WILL BE COOLER THANKS IN PART TO THE ONSHORE FLOW(SSE WIND). WIDELY SCATTERED TSTMS EXPECTED THIS AFTERNOON RIGHT ALONG THE FRONT. LATEST HRRR SHOWED A LINE OF BROKEN CONVECTION SETTING UP THIS AFTERNOON BUT NOT SEVERE. IT LOOK LIKE ANY TSTMS WILL HAVE HEAVY RAIN AS WBZS ARE ABOVE 11K FT AND FORCING IN RATHER WEAK. THERE IS SOME LLVL CONVERGENCE SETTING UP AHEAD AND ALONG THE BOUNDARY AS IT MOVES THROUGH THIS AFTERNOON. THEREFORE, ADJUSTED POPS DOWN A BIT DUE TO THIS THINKING. PREVIOUS DISCUSSION... VERY WEAK FRONTAL BNDRY CURRENTLY JUST W AND NW OF THE AREA W/ A MILD AND RATHER HUMID LGT SRLY IN PLACE ACROSS OUR REGION AHEAD OF THIS SYSTEM... A FEW VRY LGT SHOWERS APPEAR TO BE LIFTING NE ACROSS THE FA PER RADAR THO NO RPTG STATIONS HAVE CARRIED ANY PRECIP LAST FEW HRS. EVEN AN ISOLD TSTM NOTED JUST W OF OUR BORDER ATTM - TO THE NW OF DAAQUAM. OTHER FEATURE OF INTEREST ERLY THIS AM IS ANOTHER LOW PRES SYSTEM WELL SW OF THEN AREA - JUST S OF THE CAPE... THE WEAK FRONTAL BNDRY WILL CONT TO SLOWLY CROSS THE AREA TDY W/ A BIT STRONGER FRONT ADVERTISED FOR FRI. LOW PRES WELL SW OF THE AREA SIMILAR TO THE SYSTEM THAT AFFECTED THE REGION YESTERDAY - THO WEAKER W/ THIS ONE EXPECTED TO TRACK A LITTLE FURTHER S AND E OF THE AREA. AS A RESULT...EXPECT PRECIP ASSOCIATED W/ THIS SYSTEM TO NOT BE A FACTOR... WILL CONT W/ PREVIOUS FCST THINKING AND WILL CARRY JUST CHC POPS TDY ACROSS THE FA AS UPPER SUPPORT W/ THIS SYSTEM APPEARS RELATIVELY WEAK. SYSTEM SUPPORTED SOME CONVECTION TO OUR W YESTERDAY AND W/ TDS IN THE 60S TDY...SFC HEATING SHOULD ALLOW FOR A THREAT OF THUNDER OUR AREA TDY AS WELL SPCLY DURING THE AFTN HRS. TEMPS EXPECTED TO WARM A FEW DEGREES OVER YESTERDAY W/ LOWS TNGT AGAIN SIMILAR TO THE LAST FEW NGTS. LATE NGT/ERLY AM LOW CIGS AND FOG A CONTG THREAT...SPCLY ACROSS THE SRN AREAS NEAR THE COAST. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... A COLD FRONT WILL MOVE ACROSS THE REGION ON FRIDAY, BRINGING THE CHANCES FOR SHOWERS AND THUNDERSTORMS TO MUCH OF THE STATE. AHEAD OF THE FRONT, SOUTH FLOW WILL KEEP MUGGY CONDITIONS AROUND AS DEWPOINTS REACH INTO THE LOWER AND MID 60S. HIGHS WILL RANGE FROM AROUND 80 IN THE SAINT JOHN VALLEY TO THE UPPER 80S ACROSS THE INTERIOR DOWNEAST. DRIER AIR WILL WORK INTO THE REGION BEHIND THE FRONT, LEADING TO A PLEASANT NIGHT FRIDAY NIGHT. HOWEVER, HUMIDITY WILL BEGIN TO MAKE ITS RETURN TO MAINE LATE SATURDAY AS THE COLD FRONT SLOWLY MOVES BACK NORTH AS A WARM FRONT. NORTHERN AREAS WILL SEE A NICE SUMMER DAY ON SATURDAY WITH HIGHS AROUND 80 AND LOW HUMIDITY. MEANWHILE, DOWNEAST MAINE WILL SEE A RETURN TO MUCH WARMER AND MUGGIER CONDITIONS; HIGHS WILL BE IN THE MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE WARM FRONT LIFTS ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY AS LOW PRESSURE MOVES EASTWARD THROUGH THE GREAT LAKES. THIS SYSTEM WILL MOVE NORTH OF THE FORECAST AREA SUNDAY NIGHT INTO MONDAY, DRAGGING ITS ATTENDANT COLD FRONT ACROSS NEW ENGLAND AS IT DOES SO. AS SUCH, THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE LATE SUNDAY, BUT ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY. THIS FRONT WILL BE FOLLOWED BY A BRIEF RIDGE OF HIGH PRESSURE, BRINGING COOLER TEMPERATURES AND DRY WEATHER FOR MONDAY NIGHT AND TUESDAY. PRECIP CHANCES THEN INCREASE AGAIN BY MID WEEK AS ANOTHER FRONT MOVES INTO NORTHERN MAINE. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... NEAR TERM: CURRENTLY KBHB AND KBGR IFR W/ OUR REMAINING TAF SITES VFR... EXPECT SOME LOWER CIGS TO ARRIVE KHUL NEXT HR OR SO BUT AM NOT CONFIDENT THAT THESE CONDS WILL REACH OUR NRN TAF SITES ERLY THIS AM. FOR NOW WILL JUST ADVERTISE SOME MVFR UP N IN BR W/ CONFIDENCE LOW ATTM. MORE OF THE SAME TNGT W/ BEST THREAT OF IFR AT OUR SRN TAF SITES W/ LESSER CHCS N. SHORT TERM: VFR GENERALLY EXPECTED INTO EARLY NEXT WEEK, BUT MVFR CONDITIONS WILL BE POSSIBLE IN MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS FRIDAY AND MONDAY. && .MARINE... NEAR TERM: LGT SE SWELL CURRENTLY RESULTING IN SEAS AROUND 4 FT... SEAS GENERALLY EXPECTED TO REMAIN IN THE 3-5 FT RANGE THRU TNGT IN CONTG LGT SE SWELL W/ MAINLY LGT (<15 KT SRLY WNDS). NO HEADLINES ANTICIPATED THRU TNGT W/ AREAS OF FOG CONTG MAINLY DURING THE ERLY EVE THRU MID AM HRS... SHORT TERM: A COLD FRONT WILL MOVE ACROSS THE WATERS LATE FRIDAY. AHEAD OF THIS FRONT, WAVES WILL APPROACH 5 FT AS SOUTH WINDS INCREASE. RIGHT NOW THINGS LOOK MARGINAL, BUT LATER SHIFTS WILL HAVE TO MONITOR TRENDS AS A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS MAY BE NECESSARY FRIDAY. WAVES WILL SUBSIDE FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT; NO HEADLINES SHOULD BE NECESSARY THROUGH THE WEEKEND. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT/KHW SHORT TERM...HASTINGS LONG TERM...HASTINGS AVIATION...HEWITT/KHW MARINE...HEWITT/KHW/HASTINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
626 AM CDT THU AUG 2 2012 .AVIATION... 12Z TAFS FOR KOFK...KLNK AND KOMA. VFR CONDITIONS ARE FORECAST THROUGH FRIDAY MORNING. THINNING MID AND HIGH CLOUDINESS CAN BE EXPECTED THROUGH THE AFTERNOON WITH GENERALLY LIGHT NORTHEAST WINDS UNDER 10KTS. DERGAN && .PREV DISCUSSION... /ISSUED 348 AM CDT THU AUG 2 2012/ DISCUSSION... SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS INTO THE UPPER 90S IF NOT LOWER 100S. A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY 00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY. SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING. CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO SATURDAY MORNING. COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE 80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE BUILDS TO OUR WEST. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
958 AM EDT THU AUG 2 2012 .SYNOPSIS... HIGH PRESSURE WILL GRADUALLY WEAKEN AS IT SHIFTS TO THE ATLANTIC COAST. A WEAK COLD FRONT WILL APPROACH THE AREA ON FRIDAY AND BECOME STATIONARY ACROSS THE LOWER GREAT LAKES. A STRONGER COLD FRONT WILL SWEEP ACROSS THE REGION BY SUNDAY EVENING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CURRENT FORECAST IS ON TRACK SO ONLY MINOR CHANGES PLANNED. 12Z SOUNDINGS SHOW RATHER WARM AIR IN LOW LEVELS WITH 850 MB TEMPERATURES IN THE RANGE OF +17 TO +19C. ADDITIONAL WARMING IS EXPECTED TODAY. SO WILL RAISE MAX TEMPERATURES A LITTLE IN THE TOL TO FDY AREA. THERE STILL IS A QUESTION OF WHETHER OR NOT SOME CONVECTION MAY DROP SOUTH FROM MICHIGAN AND ONTARIO LATE THIS AFTERNOON. THE HRRR EVEN DEVELOPS CONVECTION OVER NW PA AND SW NY BUT FOR NOW WILL KEEP THE FORECAST DRY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... PLENTY OF UNCERTAINTY FOR CONVECTIVE DEVELOPMENT FOR THE SHORT TERM PERIOD AS WE WATCH FOR OUTFLOW BOUNDARIES TO PUSH A WEAK COLD FRONT TOWARD LAKE ERIE TONIGHT INTO FRIDAY. IF THESE BOUNDARIES REMAIN NORTH OF LAKE ERIE IT WILL REMAIN HOT WITH A DECENT CAP ACROSS THE REGION EVEN AS LOW LEVEL MOISTURE INCREASES. THE UNCERTAINTY FOR THE WEEKEND WILL BE HOW MUCH CONVECTIVE DEBRIS WILL OCCUR. THIS MAY HAVE AN IMPACT ON HIGH TEMPERATURES AND THE AMOUNT OF CAPE AVAILABLE FOR THUNDERSTORMS. THE BEST CHANCES OF THUNDER WILL BE SATURDAY AFTERNOON INTO SUNDAY. SUNDAY S A BIT UNCERTAIN WITH BECAUSE OF THE TIMING OF A STRONGER COLD FRONT INTO NORTHERN OHIO. THE TIMING OF THIS FRONT WILL HAVE SIGNIFICANT IMPACTS ON SEVERE THUNDERSTORM CHANCES FOR THE COUNTY WARNING AREA. IT WILL REMAIN HOT INTO THE WEEKEND. AS STATED ABOVE CLOUD COVER WILL LIKELY BE AN ISSUE FOR HIGHS SATURDAY INTO SUNDAY AND COULD KEEP THE AREA SLIGHTLY COOLER THAN CURRENT THINKING. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... BEGINNING MONDAY A COLD FRONT WILL PUSH EAST OF THE AREA WITH HIGH PRESSURE BRINGING DRY WEATHER AND NEAR SEASONABLE TEMPERATURES TO THE AREA. GFS AND 00Z ECMWF QUIET A BIT DIFFERENT BY LATE IN THE PERIOD WITH ECMWF QUICKER IN BRINGING NEXT COLD FRONT THROUGH THE AREA ON WEDNESDAY. GFS SLOWER AND BRINGING FRONT ACROSS LATE NEXT WEEK. GIVEN RECENT CONDITIONS AND PREVIOUS FORECAST WILL LEAN TOWARD THE GFS WITH WARMING TEMPS AND THE FRONT NOT PUSHING THROUGH THE AREA UNTIL LATE WEEK. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... HIGH PRESSURE WILL ALLOW FOR VFR CONDITIONS TO CONTINUE TODAY. SOME MID AND HIGH CLOUDS WILL SPREAD ACROSS MAINLY NORTHERN SITES FROM TOL-CLE-ERI TODAY BUT EXPECTING ALL PRECIP TO REMAIN NORTH OF THE AREA. THE LIGHT GRADIENT WILL ALLOW FOR A LAKE BREEZE AT ERI AND EVEN CLE LATER IN AFTERNOON. THE WEAK COLD FRONT WILL MOVE OVER LAKE ERIE TONIGHT BUT WITH THE EXCEPTION OF ERI WHICH IT WILL BE IN PROXIMITY THE REMAINDER OF SITES SHOULD REMAIN SOUTH OF THE FRONT. MODELS TRYING AGAIN TO SHOW SOME WIDESPREAD MVFR VIS DEVELOPING LATE TONIGHT...BUT GIVEN PAST TRENDS WITH MODELS WILL HOLD OFF ON MENTIONING MVFR FOR NOW. .OUTLOOK...NON VFR PROBABLE IN SCATTERED THUNDERSTORMS MAINLY SATURDAY THROUGH SUNDAY. && .MARINE... HIGH PRESSURE WILL KEEP CONDITIONS ON THE LAKE QUIET TODAY. A COLD FRONT WILL MOVE SOUTH TOWARD THE LAKE LATE TODAY AND TONIGHT...AND THE BOUNDARY WILL BECOME STATIONARY NEAR THE LAKE THROUGH FRIDAY AND PERHAPS EVEN THROUGH SATURDAY WITH SOUTHEAST FLOW. THE FRONT WILL MOVE BACK NORTH LATER IN THE WEEKEND ALLOW FOR MAINLY SOUTH TO SOUTHWEST WINDS. LOW PRESSURE IS EXPECTED TO TRACK OVER THE NORTHERN GREAT LAKES SUNDAY NIGHT AND EARLY MONDAY...AND THE COLD FRONT WITH THE LOW WILL CROSS THE LAKE. SUNDAY NIGHT THROUGH MONDAY WILL BE THE NEXT OPPORTUNITY FOR SMALL CRAFT ADVISORY HEADLINES WITH WINDS SHIFTING NW AND INCREASING TOWARD 20 KNOTS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...MULLEN NEAR TERM...REL SHORT TERM...MULLEN LONG TERM...ABE AVIATION...ABE MARINE...ABE
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1030 AM CDT THU AUG 2 2012 .UPDATE... REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND NOON TO REMOVE MORNING WORDING. KRM && .DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/ FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S. ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR AN AFTERNOON SHOWER OR STORM. THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT. THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A FEW SEVERE STORMS. NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S. HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED. SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES. THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY SUNNIER SKIES. EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE LOW TO MID 90S. JAB && .AVIATION... 12Z TAF CYCLE (02/12Z-03/12Z) SHOWERS AND THUNDERSTORMS IN A BAND ACROSS PORTIONS OF EASTERN AR HAVE BEEN MOVING MAINLY NORTH TO SOUTH EARLIER THIS MORNING...REMAINING WEST OF KJBR. DID MENTION VCSH AT KJBR UNTIL 15Z AND WILL MONITOR FOR AMENDING TO ADD VCTS IF THE ACTIVITY DOES CREEP FURTHER EASTWARD. OTHERWISE VFR CONDITIONS ARE EXPECTED TO PREVAIL MOST OF THE PERIOD AT THE TAF SITES. CONTINUED MENTION OF VCTS AT ALL THE TAF SITES THIS AFTERNOON AND EARLY EVENING WITH DAYTIME HEATING. MODELS INDICATE A MESOSCALE CONVECTION SYSTEM MAY MOVE INTO THE REGION FROM THE NORTH LATE TONIGHT...FOR NOW INCLUDED VCTS AT KJBR AND KMKL AFTER 03/06Z AND AT KMEM AFTER 03/09Z. WINDS MAINLY S TO SW BECOMING 8-12 KTS TODAY...WINDS TONIGHT SOUTHERLY 4-8 KTS. JCL && && .PRELIMINARY POINT TEMPS/POPS... MEM 96 76 94 77 / 30 20 40 20 MKL 96 73 90 74 / 30 40 50 20 JBR 96 75 93 75 / 40 20 40 10 TUP 95 74 91 73 / 30 40 50 20 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL- MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO- TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
628 AM CDT THU AUG 2 2012 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT 359 AM CDT THU AUG 2 2012 AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE 02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A 700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE. AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE NMM AND ARW ALSO SUPPORT THIS TOO. FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA. THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL PASSAGE. .LONG TERM...SUNDAY THROUGH THURSDAY 359 AM CDT THU AUG 2 2012 ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE FORECAST AREA. FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES. BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT WERE PRODUCED IN THE ALL BLEND. && .AVIATION...TODAY AND TONIGHT 628 AM CDT THU AUG 2 2012 FORECAST CONCERNS ARE FOCUSED ON NEAR-TERM PRECIPITATION CHANCES...THEN FOG POTENTIAL OVERNIGHT. SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY LINGERING ACROSS SOUTHERN MINNESOTA INTO WESTERN WISCONSIN...WITH A SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS MOVING THROUGH. CONFIDENCE IS HIGH THAT THESE SHOWERS/STORMS WILL WEAKEN AND MOVE SOUTHEAST OF KRST/KLSE BY MID TO LATE MORNING AS FRONT FINALLY PUSHES THROUGH. BROKEN MID LEVEL CLOUDS WILL GRADUALLY ERODE BY LATE AFTERNOON AS HIGH PRESSURE BUILDS ACROSS NORTHERN MINNESOTA/WISCONSIN. NEXT CONCERN IS OVERNIGHT FOG POTENTIAL. GIVEN RECENT RAINFALL ACROSS THE AREA...COOLER AIR TEMPERATURES...AND BUILDING HIGH PRESSURE...WOULD EXPECT AT LEAST SOME PATCHY FOG TO DEVELOP. CONFIDENCE IS NOT HIGH ENOUGH HOWEVER TO INTRODUCE IFR OR LOWER CONDITIONS AS SUGGESTED BY SOME FORECAST MODEL GUIDANCE. WINDS IN THE LOWEST LEVELS COULD BE HIGH ENOUGH TO KEEP BOUNDARY LAYER MIXED SO FOR NOW HAVE INCLUDED A MVFR VISIBILITY AND LATER FORECASTS CAN EVALUATE POTENTIAL. && .ARX WATCHES/WARNINGS/ADVISORIES... 359 AM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...ZT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
328 PM MDT THU AUG 2 2012 .SHORT TERM... (TONIGHT AND FRIDAY) THE MONSOON MOISTURE PLUME REMAINS OVER THE AREA WITH SHOWERS AND THUNDERSTORMS OVER AND NEAR THE MOUNTAINS EARLY THIS AFTERNOON. THE MODELS ARE SHOWING THE CONVECTIVE ACTIVITY SPREADING ACRS THE PLAINS LATE THIS AFTERNOON THROUGH THE EVENING HOURS...IN ASSOCIATION WITH A WEAK DISTURBANCE WORKING ITS WAY EAST ACRS SOUTHERN CO. THE HRRR SHOWS A BAND OF PCPN COMING OFF THE MTS BY 00Z...MOVING EASTWARD ACRS THE PLAINS AND EXITING CO BY 04Z. THE NSSL 4KM WRF IS VERY SIMILAR. BASED ON THESE HIGH RES MODELS WL GO AHEAD AND END PCPN CHANCES IN THE FORECAST BY MIDNIGHT...HOWEVER BOTH THE NAM AND GFS KEEP CHANCES FOR PCPN OVR THE FAR SERN PLAINS THROUGH THE NIGHT AND INTO FRI MORNING. THERE IS THE POTENTIAL FOR HEAVY RAIN TODAY UNDER SOME OF THE STRONGER STORMS...WITH THE WALDO CANYON BURN SCARS BEING THE MOST VULNERABLE IF HEAVY RAIN DEVELOPS OVR THAT AREA. ON FRI THE BULK OF THE MONSOON MOISTURE WILL BE OVR SOUTHERN PORTIONS OF THE FORECAST AREA...AS AN UPR TROF OVR THE NRN ROCKIES FLATTENS THE RIDGE OVR OUR AREA. THUS THE BEST CHANCES FOR CONVECTIVE ACTIVITY SHOULD OCCUR OVR THE SRN HALF OF THE CWA. THE GFS HAS LITTLE IN THE WAY OF PCPN COVERAGE FOR FRI AFTERNOON...WHILE THE NAM HAS A LITTLE MORE COVERAGE OVER THE FAR SOUTHEAST PLAINS...THE SANGRES AND THE EASTERN SAN JUANS. HIGH TEMPS ON FRIDAY SHOULD BE A FEW DEGREES ABOVE NORMAL IN MOST LOCATIONS. .LONG TERM... (FRIDAY NIGHT THROUGH THURSDAY) LONGER TERM METEOROLOGICAL ISSUES CONTINUE TO BE POPS AND TEMPERATURES. LATEST COMPUTER SOLUTIONS INDICATE THAT STRONG UPPER RIDGE CENTERED OVER NORTHWESTERN TEXAS AT 00Z SATURDAY WILL BEGIN TO PUSH WEST INTO NEW MEXICO BY LATER SUNDAY BEFORE BECOMING CENTERED NEAR THE 4-CORNERS REGION BY NEXT TUESDAY. IN ADDITION...HEALTHY NORTHERLY SURGE IS PROJECTED TO PUSH ACROSS EASTERN SECTIONS OF THE FORECAST DISTRICT BY SATURDAY MORNING. ENOUGH ATMOSPHERIC MOISTURE IS EXPECTED TO REMAIN AVAILABLE OVER THE FORECAST DISTRICT AND COMBINE WITH OCCASIONAL UPPER WAVES AND THE DAILY HEATING CYCLE/SURFACE BOUNDARIES TO ALLOW DAILY ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER THE HIGHER TERRAIN REGIONS. SOME OF THE STRONGER THUNDERSTORMS ARE EXPECTED TO PRODUCE PERIODS OF LOCALLY HEAVY RAINFALL CAPABLE OF PRODUCING LOCALIZED FLASH FLOODING ISSUES...ESPECIALLY IF A STORM DIRECTLY IMPACTS BURN SCAR AREAS...SUCH AS THE WALDO BURN SCAR. IN ADDITION...THE STRONGER STORMS WILL ALSO BE CAPABLE OF PRODUCING HAZARDOUS LIGHTNING...HAIL AND GUSTY WINDS. FINALLY...BELOW SEASONAL MAXIMUM TEMPERATURES SHOULD BE NOTED IN THE WAKE OF THE STRONG NORTHERLY SURGE SATURDAY(ESPECIALLY EASTERN SECTIONS) WITH MAXIMUM TEMPERATURES THEN REBOUNDING TO ABOVE EARLY AUGUST SEASONAL AVERAGES NEXT WEEK. && .AVIATION... KALS...KCOS AND KPUB WILL HAVE VFR CONDITIONS MOST OF THE TIME DURING THE NEXT 24 HRS. THERE WILL BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AT OR IN THE VCNTY OF THE TAF SITES THROUGH AROUND 03Z. THUNDERSTORMS COULD BRING BRIEF MVFR CONDITIONS TO THE TAF SITES. OUTFLOW WINDS COULD ALSO BRING WIND GUSTS UP TO 45 KTS. ON FRIDAY AFTERNOON WE COULD SEE SOME THUNDERSTORMS IN THE VCNTY OF THE TAF SITES AFTER 20Z...BUT CONFIDENCE IS LOW. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
155 PM EDT THU AUG 2 2012 .SYNOPSIS... 17Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW THE SOUTHEASTERN CONUS AND EASTERN GULF UNDERNEATH A SUBTLE HEIGHT WEAKNESS BETWEEN A DOMINANT UPPER RIDGE OVER THE SOUTHERN PLAINS AND ANOTHER RIDGE OVER CUBA/BAHAMAS. AT THE SURFACE...SUBTROPICAL RIDGE AXIS EXTENDS ACROSS THE SOUTH-CENTRAL FLORIDA PENINSULA PROVIDING A LIGHT LOW LEVEL FLOW OUT OF THE SW TO THE MAJORITY OF THE FORECAST AREA. && .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)... TONIGHT...SUBTROPICAL RIDGE AXIS BEGINS TO SHIFT SLOWLY NORTHWARD OVER THE FLORIDA PENINSULA/EASTERN GULF IN RESPONSE TO THE APPROACH OF A WEAK INVERTED TROUGH/WAVE TO THE EAST OF THE BAHAMAS. MAINLY INLAND SCT CONVECTION EARLY THIS EVENING SHOULD DISSIPATE WITHIN A COUPLE HOUR OF SUNSET SETTING UP DRY CONDITIONS FOR MUCH OF THE AREA FROM LATE NIGHT INTO THE EARLY MORNING HOURS. WITH THE UPPER HEIGHT WEAKNESS STILL IN PLACE OVER THE EASTERN GULF...WOULD EXPECT TO SEE AT LEAST SOME DEGREE OF NOCTURNAL CONVECTION REDEVELOP TOWARD DAWN OVER THE COASTAL WATERS. THE RIDGE AXIS LIFTING NORTH WILL ALSO SHIFT THE FAVORED SW FLOW NORTH...SO WOULD ANTICIPATE THE MAJORITY OF THIS ACTIVITY TO DEVELOP OVER THE NORTHERN WATERS/ALONG THE NATURE COAST. FURTHER SOUTH (SOUTH OF TAMPA BAY)...A 1000-700MB FLOW MORE PARALLEL TO THE COAST (OR EVEN SOUTHEASTERLY) SHOULD GENERALLY KEEP ANY ISOLATED CELLS FROM MIGRATING BACK TO THE BEACHES. FRIDAY...TYPICAL EARLY AUGUST CONDITIONS ARE EXPECTED FOR THE FINAL DAY OF THE WORK WEEK. WILL BE CONTINUING TO WATCH THE SLOW APPROACH OF A WEAK SURFACE TROUGH TOWARD THE FLORIDA EAST COAST...HOWEVER MUCH OF THE LOW LEVEL FOCUS ASSOCIATED WITH THIS FEATURE WILL REMAIN TO OUR EAST DURING THE FAVORED DIURNAL CONVECTIVE MAX TIME-FRAME. 1000-700MB FLOW WILL INITIALLY BE QUITE LIGHT AHEAD OF THIS TROUGH ALLOWING THE WEST COAST SEA-BREEZE TO BE THE DOMINANT TRIGGER FOR ISOLATED-SCT CONVECTION NEAR THE COAST IN THE EARLY AFTERNOON. LATER IN THE DAY...AS THE TROUGH GETS A BIT CLOSER...THE FLOW WILL TRANSITION MORE EASTERLY. WITH THIS IN MIND...IT IS LIKELY THAT THE SEA-BREEZE WILL BE SIGNIFICANTLY SLOWED IN ITS INLAND PROPAGATION. THE ENHANCED LOW LEVEL CONVERGENCE MAY ALLOW FOR A FEW STRONGER UPDRAFTS/PRECIPITATION LOADING AND A RESULTING ISOLATED CONVECTIVE WIND THREAT. UNLIKE PREVIOUS DAYS...THIS PATTERN SHOULD PREVENT THE LATE AFTERNOON DROP OFF IN CONVECTIVE COVERAGE CLOSE TO THE COAST. FRIDAY NIGHT/SATURDAY... SURFACE TROUGH OVERSPREADS THE FLORIDA PENINSULA AND BECOMES ESTABLISHED OVER THE WEST COAST DURING SATURDAY AFTERNOON. THE COMBINATION OF INCREASING COLUMN MOISTURE...AND LOW LEVEL FOCUS SHOULD HELP TO PROVIDE A CONVECTIVE ACTIVE PERIOD...ESPECIALLY DURING SATURDAY AFTERNOON/EVENING. 1000-700MB FLOW IS STRAIGHT OUT OF THE EAST AND THEREFORE QUITE FAVORABLE FOR ENHANCED CONVERGENCE ALONG THE WEST-COAST SEA-BREEZE. SIMILAR TO FRIDAY...THIS PATTERN SHOULD SUPPORT A FEW STRONGER UPDRAFTS AND THE POTENTIAL FOR SOME LOCALIZED STRONGER STORMS. && .LONG TERM (SUNDAY - NEXT WEDNESDAY)... U/L RIDGE WILL PERSIST OVER THE ATLANTIC EXTENDING OVER THE SOUTHERN PLAINS SUNDAY. U/L TROUGH WILL DIG OVER THE OHIO RIVER VALLEY MONDAY AND TEMPORARILY WEAKEN THE RIDGE OVER FLORIDA. THE U/L RIDGE WILL BUILD BACK OVER FLORIDA TUESDAY AND WEDNESDAY WITH INCREASING SUBSIDENCE AND WARMER TEMPERATURES ACROSS WEST CENTRAL AND SOUTHWEST FLORIDA. AT THE SURFACE...A TROPICAL WILL WAVE MOVE ACROSS THE PENINSULA SUNDAY INCREASING DEEP LAYER MOISTURE AND INSTABILITY. EASTERLY FLOW WILL ALLOW NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP WITH LOCALLY HEAVY RAIN AND GUSTY WINDS WITH THE STRONGER STORMS BOTH SUNDAY AND MONDAY. SURFACE RIDGE WILL BUILD ACROSS THE CENTRAL PENINSULA TUESDAY AND WEDNESDAY. AS THE U/L RIDGE BUILDS BACK OVER FLORIDA AND DRIER AIR ALOFT ADVECTING OVER THE FORECAST AREA...AREAL COVERAGE OF AFTERNOON SHOWERS AND THUNDERSTORMS WILL DECREASE EACH DAY. && .AVIATION... SOME SHOWERS AND STORMS VICINITY TPA...PIE AND SRQ SHOULD MOVE EAST OF TERMINALS BY 20Z. PGD...FMY AND RSW SHOULD STAY MAINLY VFR. HIGHEST PROBABILITY OF MVFR OR EVEN IFR WOULD BE AT LAL BUT CONFIDENCE NOT HIGH ENOUGH FOR TEMPO GROUPS AT THIS TIME. && .MARINE... THE SUBTROPICAL RIDGE AXIS WILL SLOWLY SHIFT NORTH OVER THE AREA THROUGH FRIDAY AND THEN REMAIN TO THE NORTH OF THE FORECAST WATERS THROUGH THE UPCOMING WEEKEND. THIS MOVEMENT WILL SHIFT SYNOPTIC FLOW FROM THE SOUTH AND SOUTHWEST TO AN EAST AND SOUTHEAST DIRECTION. LOCAL SEA-BREEZE CIRCULATIONS WILL TURN THE FLOW ONSHORE NEAR THE COAST EACH AFTERNOON. && .FIRE WEATHER... BEST RAIN CHANCES WILL BE ACROSS THE INTERIOR NEXT COUPLE OF DAYS AS WESTERLY FLOW CONTINUES. A TROPICAL WAVE WILL BRING HIGHER RAIN CHANCES TO THE GULF COAST OVER THE WEEKEND AND INTO THE FIRST PART OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 77 92 77 91 / 20 40 20 40 FMY 76 93 75 92 / 20 40 20 60 GIF 75 94 74 94 / 30 40 20 40 SRQ 76 92 75 92 / 10 40 20 40 BKV 69 93 71 92 / 20 30 20 40 SPG 79 91 79 91 / 20 30 20 40 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA AVIATION...JILLSON LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 PM CDT THU AUG 2 2012 .DISCUSSION... 308 PM CDT THE MAIN CONCERNS DURING THE FORECAST PERIOD ARE CONVECTIVE CHANCES AND TIMING...ESPECIALLY ON SATURDAY AFTERNOON AND NIGHT...ALONG WITH THE WARM TEMPERATURES FRIDAY AND SATURDAY. A WEAK AND ILL DEFINED COOL FRONTAL BOUNDARY HAS DROPPED ACROSS SOUTHERN WISCONSIN THIS AFTERNOON. THE CONVECTIVE THREAT ACROSS FAR NORTHERN ILLINOIS LATE THIS AFTERNOON CONTINUES TO LOOK VERY LOW. THE CLOUD COVER SHOWN ON REGIONAL SATELLITE IMAGERY ACROSS NORTHERN ILLINOIS DOES NOT HAVE MUCH OF A CONVECTIVE LOOK TO IT. IN ADDITION...AN AMDAR SOUNDING OUT OF MDW INDICATES THAT INSTABILITY IS VERY WEAK. SO IT APPEARS THE AREA WILL LIKELY REMAIN DRY. TONIGHT INTO FRIDAY...THE MODEL GUIDANCE IS INDICATING THAT SEVERAL MID LEVEL SHORT WAVE PERTURBATIONS WILL BE EJECTED EASTWARD ACROSS THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS WITHIN THE STRONG WESTERLIES ACROSS THE PLAINS AND UPPER MIDWEST. THE STRONGEST OF THESE DISTURBANCES...CURRENTLY ACROSS KANSAS AND NORTHWESTERN MISSOURI...WILL MOVE EAST SOUTHEASTWARD ACROSS DOWNSTATE ILLINOIS AND ACROSS THE SOUTHERN APPELLATIONS TONIGHT INTO FRIDAY. THIS WILL LIKELY FOCUS MOST OF THE CONVECTION SOUTH OF THE AREA DURING THIS PERIOD. HOWEVER...IT APPEARS THAT A SURFACE WARM FRONT/TROUGH...ASSOCIATED WITH A WEAK SURFACE WAVE ACROSS THE PLAINS...WILL BE IN PLACE ACROSS NORTHERN ILLINOIS ON FRIDAY. MODEL BUFFER SOUNDINGS ACROSS THE REGION ON FRIDAY DO INDICATE AN INCREASE IN INSTABILITY AS BETTER BOUNDARY LAYER MOISTURE GETS TRANSPORTED NORTHWARD. OVERALL THIS DOES NOT LOOKS LIKE A GOOD SETUP FOR WIDESPREAD CONVECTION AS MOST OF THE LARGER SCALE SUPPORT WILL BE WELL TO THE SOUTH OF THE AREA. HOWEVER...I CANT RULE OUT SOME ISOLATED STORMS DEVELOPING ACROSS PORTIONS OF THE AREA DURING THE AFTERNOON...ESPECIALLY WITH A LOW LEVEL BOUNDARY/CONVERGENCE ZONE IN PLACE. MOST MODEL GUIDANCE KEEPS THE AREA DRY...BUT SOME OF THE CONVECTIVE ALLOWING MODELS DO ALLOW SOME ISOLATED ACTIVITY TO DEVELOP ACROSS PORTIONS OF THE AREA. WITH THIS IN MIND...I WILL CONTINUE TO MENTION THE SLIGHT CHANCE POPS FOR FRIDAY INTO FRIDAY NIGHT...MAINLY SOUTH OF INTERSTATE 80. FINALLY LATER SATURDAY AND SATURDAY NIGHT THE STRONG SHORT WAVE TROUGH IS EXPECTED TO MOVE ACROSS THE DAKOTAS EASTWARD ACROSS THE UPPER GREAT LAKES. AT THE SURFACE...A POTENT AREA OF LOW PRESSURE WILL LIKELY DRIVE A COLD FRONT ACROSS NORTHERN ILLINOIS SOMETIME SATURDAY EVENING AND ACROSS NORTHWESTERN INDIANA OVERNIGHT. THERE CONTINUES TO BE SOME UNCERTAINTY WITH THE TIMING OF THIS SYSTEM AS THE GFS ENSEMBLES STILL SHOW SOME DECENT SPREAD. IN SPITE OF THESE TIMING DIFFERENCES...THIS STILL PROMISES TO PRODUCE BY FAR THE BEST POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA DURING THE FORECAST PERIOD. IT CURRENTLY APPEARS THE BEST CHANCES FOR THUNDERSTORMS WILL BE SATURDAY NIGHT. THERE IS ALSO A POTENTIAL FOR A SEVERE THREAT AS WELL SATURDAY NIGHT. HOWEVER...THERE REMAINS QUESTIONS AS TO WHETHER OR NOT THE STRONGER MID LEVEL FLOW WILL COINCIDE WITH THE UNSTABLE AIRMASS...OR IF IT WILL LAG BEHIND THE FRONT. TEMPERATURES FRIDAY AND SATURDAY WILL CONTINUE TO BE IN THE 90S. I AM CONCERNED THAT WE WILL BE FLIRTING WITH HEAT ADVISORY CRITERIA ACROSS MUCH OF THE AREA ON SATURDAY. MOISTURE SHOULD INCREASE SUBSTANTIALLY ON SATURDAY AHEAD OF THE APPROACHING COLD FRONT. SURFACE DEW POINTS LOOK TO CLIMB INTO THE LOW 70S DURING THE DAY. THIS COMBINED WITH TEMPERATURES IN THE MID TO PERHAPS UPPER 90S IN A FEW AREAS...LOOKS TO PRODUCE HEAT INDICES AROUND 105 DEGREES. MUCH COOLER AND DRIER WEATHER MOVES ACROSS THE AREA FOR SUNDAY INTO NEXT WEEK. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * WIND DIRECTIONS INTO FRIDAY MORNING. TRS //DISCUSSION...UPDATED 22Z... LAKE BREEZE HAS CONTINUED TO PUSH WELL INLAND TO WRN MCHENRY...NW KANE W CNTRL DUPAGE COUNTIES DURING THE MID-LATE AFTERNOON BUT MORE SLOWLY ACROSS SE DUPAGE AND SRN COOK INTO NRN LAKE COUNTY AS 950HPA VAD WINDS AT KLOT AND TMDW SHOWING ESE AROUND 10KT WHILE TMDW AND TMKE SHOWING E TO ENE 10-15KT. 20Z AND 21Z RUC13 RUNS DEPICTING VERY SHORT TERM WINDS WELL MAINTAINING E-ENE 10-15 KT SFC WINDS AT ORD SO HAVE FOLLOWED THIS OUTPUT. TRS PREVIOUS 18Z DISCUSSION... WIND DIRECTIONS WILL REMAIN PROBLEMATIC INTO FRIDAY MORNING DUE TO A FAIRLY WEAK GRADIENT AND POTENTIAL FOR A LAKE BREEZE THIS AFTERNOON. WEAK HIGH PRESSURE WILL MOVE EAST ACROSS THE OHIO VALLEY THIS AFTERNOON AS WEAK LOW PRESSURE OVER NORTHERN MISSOURI SLOWLY DRIFTS EAST/NORTHEAST TONIGHT INTO FRIDAY MORNING. IN BETWEEN THESE TWO FEATURES...THE WINDS HAVE BECOME LIGHT AND VRB AND EVEN CALM ACROSS THE AREA. LOW LEVEL WINDS ALSO ARE FAIRLY LIGHT AND EXPECT A LAKE BREEZE TO DEVELOP. WHETHER ITS THE LAKE BREEZE ITSELF OR A COMBINATION WITH THE GRADIENT...EXPECT WINDS TO TURN SOUTHEASTERLY EARLY THIS AFTERNOON AND MORE EAST/SOUTHEAST BY MID/LATE AFTERNOON. HAVE KEPT LAKE BREEZE TIMING UNCHANGED BUT WILL NEED TO MONITOR THROUGH THE EARLY AFTERNOON. GRADIENT REMAINS LIGHT OVERNIGHT AND EXPECT PERIODS OF LIGHT AND VARIABLE WINDS THOUGH ANY PREVAILING WINDS LIKELY TO BE EAST/SOUTHEASTERLY... ESPECIALLY TOWARD MORNING. GRADIENT TIGHTENS UP ENOUGH FOR MAINLY EASTERLY WINDS UP TO 10KTS ON FRIDAY...POSSIBLY TURNING A BIT MORE NORTHEASTERLY IN THE AFTERNOON. GUIDANCE CONTINUES TO HINT AT SOME LIGHT FOG/HAZE FRIDAY MORNING. GIVEN THE RELATIVELY DRY GROUND CERTAINLY NOT EXPECTING ANYTHING TOO LOW OR WIDESPREAD BUT GIVEN THE LIGHT WINDS IF TEMPS CAN FALL OFF TO THE DEWPOINTS...COMBINED WITH THE LIGHT WINDS...THERE COULD BE SOME PATCHY/GROUND FOG. WITH THE WEAK LOW EXPECTED TO PASS SOUTH OF THE TERMINALS ON FRIDAY...EXPECT ANY PRECIP/CONVECTION TO ALSO REMAIN SOUTH OF THE TERMINALS BUT SOME ISOLATED ACTIVITY IN THE AFTERNOON IS POSSIBLE BUT CONFIDENCE AND EXPECTED COVERAGE TOO LOW TO INCLUDE IN THIS FORECAST. CMS //ORD AND MDW CONFIDENCE...UPDATED 22Z... * HIGH CONFIDENCE IN WIND TRENDS THROUGH EARLY EVENING. * HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS WITH NO SIG WX TO OCCUR. TRS //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT...VFR. SATURDAY...VFR. SLGT CHANCE TSRA/SHRA INCREASING TO CHANCE IN THE AFTERNOON. PERIODS MVFR/IFR PSBL. SUNDAY THROUGH WEDNESDAY...VFR. JEE && .MARINE... 243 PM CDT AN AREA OF LOW PRESSURE CENTERED ACROSS FAR SOUTHWEST QUEBEC CONTINUES TO WEAKEN AND DRIFT NORTHEAST...WITH A TRAILING FRONTAL BOUNDARY STRETCHING WEST/SOUTHWEST THROUGH NORTHERN MICHIGAN INTO NORTHERN WISCONSIN. THIS BOUNDARY IS EXPECTED TO DRIFT SOUTH ACROSS LAKE MICHIGAN THIS EVENING...WITH WINDS TURNING NORTH/NORTHEAST ACROSS NORTHERN LAKE MICHIGAN. MEANWHILE AN AREA OF HIGH PRESSURE OVER WESTERN ONTARIO WILL CONTINUE TO PUSH EAST ACROSS ONTARIO...AS THE FRONTAL BOUNDARY OVER LAKE MICHIGAN SLOWLY ERODES. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE WESTERN DAKOTAS FRIDAY NIGHT...THEN STRENGTHEN AS THIS LOW PRESSURE SLIDES EAST ACROSS THE UPPER MIDWEST AND LAKE SUPERIOR SATURDAY AFTERNOON. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN ALONG THIS AREA OF LOW PRESSURE SAT NIGHT FOR CENTRAL/NORTHERN LAKE MICHIGAN AND COULD BE TIGHT ENOUGH TO CREATE OCCASIONAL GALE FORCE GUSTS SUNDAY. THEN THE FRONTAL BOUNDARY PUSHES EAST OF LAKE MICHIGAN SUNDAY AND BROAD HIGH PRESSURE THEN BUILDS IN FOR EARLY NEXT WEEK...WITH SEVERAL PERIODS OF LIGHT FLOW FROM THE NORTH TO NORTHEAST. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1240 PM CDT THU AUG 2 2012 .AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU WEAK PV ANOMALY WILL CONTINUE MOVING SLOWLY EASTWARD ACROSS SOUTH CENTRAL/SOUTHEAST KS THIS AFTERNOON. THIS SHOULD ALLOW FOR ISOLATED-WIDELY SCATTERED HIGH-BASED -SHRA/-TSRA TO PERSIST THIS AFTERNOON. WILL MENTION VCSH AT HUT/ICT/SLN BASED ON LATEST RADAR TRENDS. THERE WILL BE A SMALL CHANCE OF HIGH-BASED -TSRA TONIGHT INTO FRIDAY MORNING ACROSS THE AREA...WITH HIGH PRECIPITABLE WATER AXIS REMAINING ALONG WITH WEAKNESS AT 700 MB. CHANCES APPEAR TOO LOW TO MENTION AT TAF SITES THIS FAR OUT ESPECIALLY GIVEN COVERAGE CONCERNS. GUSTY WINDS POSSIBLE NEAR ANY STORM ACTIVITY GIVEN TEMPERATURE-DEWPOINT SPREADS. OTHERWISE VFR TO PREVAIL. JMC && .PREV DISCUSSION... /ISSUED 800 AM CDT THU AUG 2 2012/ UPDATE... WITH THE -SHRA & -TSRA HAVING VACATED CNTRL & SE KS HAVE UPDATED ALL AFFECTED PRODUCTS TO REMOVE THE MORNING MENTION OF THIS ACTIVITY. PREV DISCUSSION... /ISSUED 653 AM CDT THU AUG 2 2012/ AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10 TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING & ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED ATTENTION WITH 00Z & 06Z TAF ISSUANCES. PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/ DISCUSSION... TODAY-TONIGHT: ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400. CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH IT. FRI-FRI NIGHT: HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW... COULD BE EVEN WARMER THAN FORECAST. SAT-SUN: GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD. LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT... WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN SECTIONS. MON-WED: CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH. INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED. WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD. -HOWERTON AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 107 78 104 78 / 20 20 10 10 HUTCHINSON 103 76 103 76 / 20 20 10 10 NEWTON 103 77 102 77 / 20 20 10 10 ELDORADO 104 77 104 77 / 20 20 10 10 WINFIELD-KWLD 111 80 106 80 / 20 20 10 10 RUSSELL 98 73 101 73 / 20 30 10 20 GREAT BEND 100 74 102 74 / 20 20 10 20 SALINA 98 76 102 75 / 20 30 10 20 MCPHERSON 101 75 103 75 / 20 30 10 20 COFFEYVILLE 110 79 106 79 / 20 20 10 10 CHANUTE 105 76 103 78 / 20 20 10 10 IOLA 103 77 102 77 / 20 20 10 10 PARSONS-KPPF 107 77 104 79 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ069- 082-083-091>096-098>100. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1221 PM CDT THU AUG 2 2012 ...UPDATE TO AVIATION... .DISCUSSION... ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH. THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY. NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT AN ADVISORY. FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST. MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY. FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS. WOLTERS && .AVIATION... STILL OUTSIDE CHANCE FOR A SHOWER OR STORM AT ONE OF THE TERMINALS THIS AFTERNOON THEN AGAIN OVERNIGHT...HOWEVER MOST GUIDANCE SUGGEST STORMS TO STAY SOUTH. WITH BOUNDARY TO THE SOUTH HAVE NE WINDS BLO 12KTS AND VFR CIGS...WILL WATCH FOR BR OVERNIGHT BUT THINK RAIN AMOUNTS WERE LOW ENOUGH TO NEGATE THAT THREAT. 67 && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
204 PM EDT THU AUG 2 2012 .UPDATE... ISSUED AT 204 PM EDT THU AUG 2 2012 PREVIOUS FORECAST WAS LARGELY ON TRACK...AND ONLY MINOR ADJUSTMENTS WERE MADE. UPDATE ISSUED AT 1057 AM EDT THU AUG 2 2012 HAVE LOWERED CLOUD COVER FOR TODAY TO GIVE A SUNNY FORECAST OVERALL. WHAT CUMULUS THAT DO POP UP SHOULD BE LIMITED AND MAINLY IN THE FAR SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. HAVE ALSO ADDED A BIT OF THE TYPICAL LATE SUMMER VALLEY FOG FOR LATE TONIGHT. THE NAM IS ALSO ADVECTING ELEVATED INSTABILITY INTO OUR SW COUNTIES OVERNIGHT ON ISENTROPIC LIFT. ALTHOUGH IT IS NOT AS PRONOUNCED IN THE GFS...IT IS PERSISTENT NOW IN THE NAM...AND HAVE ADDED A SLIGHT CHANCE POP FOR THIS. UPDATE ISSUED AT 700 AM EDT THU AUG 2 2012 A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS. LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON. HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP THE ZONES TO REMOVE THE PRE FIRST PERIOD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 340 AM EDT THU AUG 2 2012 SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY... INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE. OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON. CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION TODAY. GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY. TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID 90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH. THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE MOMENT AND MENTION BOTH IN THE HWO. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 AM EDT THU AUG 2 2012 THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS THE SETTING SUN WILL STABILIZE THE AIR MASS AND FINALLY GIVE THE AREA A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND LOWER 90S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 204 PM EDT THU AUG 2 2012 MOST VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. THERE WILL BE A COUPLE OF EXCEPTIONS...THOUGH. VALLEY FOG WILL BRING LOCALIZED IFR LATE TONIGHT INTO EARLY FRIDAY MORNING. THUNDERSTORMS MAY DEVELOP FROM SW TO NE OVER THE AREA OVERNIGHT AND ON FRIDAY. AT THIS POINT...THE PROBABILITY LOOKS TOO LOW TO WARRANT ANYTHING MORE THAN VCTS AT TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...MB LONG TERM....DUSTY AVIATION...HAL
AREA FORECAST DISCUSSION
NWS CARIBOU ME
157 PM EDT THU AUG 2 2012 .SYNOPSIS... A WEAKENING COLD FRONT WILL CROSS THE REGION THIS AFTERNOON. ANOTHER COLD FRONT WILL CROSS THE AREA ON FRIDAY. HIGH PRESSURE WILL RETURN FOR SATURDAY WITH PLEASANTLY WARM BUT LESS HUMID AIR. WARMER AND MORE HUMID CONDITIONS RETURN ON SUNDAY AHEAD OF ANOTHER COLD FRONT EXPECTED TO CROSS THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE: ADDED HEAVY RAIN WORDING THE WX ELEMENT AS STORM MOTION LESS THAN 10 KTS AND LATEST LAPS SOUNDINGS INDICATE K INDEX OF 35+ WEHRE STORMS ARE FIRING. STORMS ARE SLOW MOVING AND COULD DUMP UP TO 1"RAFL/HR. PREVIOUS DISCUSSION... WIDELY SCATTERED TSTMS EXPECTED THIS AFTERNOON RIGHT ALONG THE FRONT. LATEST HRRR SHOWED A LINE OF BROKEN CONVECTION SETTING UP THIS AFTERNOON BUT NOT SEVERE. IT LOOK LIKE ANY TSTMS WILL HAVE HEAVY RAIN AS WBZS ARE ABOVE 11K FT AND FORCING IN RATHER WEAK. THERE IS SOME LLVL CONVERGENCE SETTING UP AHEAD AND ALONG THE BOUNDARY AS IT MOVES THROUGH THIS AFTERNOON. THEREFORE, ADJUSTED POPS DOWN A BIT DUE TO THIS THINKING. PREVIOUS DISCUSSION... VERY WEAK FRONTAL BNDRY CURRENTLY JUST W AND NW OF THE AREA W/ A MILD AND RATHER HUMID LGT SRLY IN PLACE ACROSS OUR REGION AHEAD OF THIS SYSTEM... A FEW VRY LGT SHOWERS APPEAR TO BE LIFTING NE ACROSS THE FA PER RADAR THO NO RPTG STATIONS HAVE CARRIED ANY PRECIP LAST FEW HRS. EVEN AN ISOLD TSTM NOTED JUST W OF OUR BORDER ATTM - TO THE NW OF DAAQUAM. OTHER FEATURE OF INTEREST ERLY THIS AM IS ANOTHER LOW PRES SYSTEM WELL SW OF THEN AREA - JUST S OF THE CAPE... THE WEAK FRONTAL BNDRY WILL CONT TO SLOWLY CROSS THE AREA TDY W/ A BIT STRONGER FRONT ADVERTISED FOR FRI. LOW PRES WELL SW OF THE AREA SIMILAR TO THE SYSTEM THAT AFFECTED THE REGION YESTERDAY - THO WEAKER W/ THIS ONE EXPECTED TO TRACK A LITTLE FURTHER S AND E OF THE AREA. AS A RESULT...EXPECT PRECIP ASSOCIATED W/ THIS SYSTEM TO NOT BE A FACTOR... WILL CONT W/ PREVIOUS FCST THINKING AND WILL CARRY JUST CHC POPS TDY ACROSS THE FA AS UPPER SUPPORT W/ THIS SYSTEM APPEARS RELATIVELY WEAK. SYSTEM SUPPORTED SOME CONVECTION TO OUR W YESTERDAY AND W/ TDS IN THE 60S TDY...SFC HEATING SHOULD ALLOW FOR A THREAT OF THUNDER OUR AREA TDY AS WELL SPCLY DURING THE AFTN HRS. TEMPS EXPECTED TO WARM A FEW DEGREES OVER YESTERDAY W/ LOWS TNGT AGAIN SIMILAR TO THE LAST FEW NGTS. LATE NGT/ERLY AM LOW CIGS AND FOG A CONTG THREAT...SPCLY ACROSS THE SRN AREAS NEAR THE COAST. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... A COLD FRONT WILL MOVE ACROSS THE REGION ON FRIDAY, BRINGING THE CHANCES FOR SHOWERS AND THUNDERSTORMS TO MUCH OF THE STATE. AHEAD OF THE FRONT, SOUTH FLOW WILL KEEP MUGGY CONDITIONS AROUND AS DEWPOINTS REACH INTO THE LOWER AND MID 60S. HIGHS WILL RANGE FROM AROUND 80 IN THE SAINT JOHN VALLEY TO THE UPPER 80S ACROSS THE INTERIOR DOWNEAST. DRIER AIR WILL WORK INTO THE REGION BEHIND THE FRONT, LEADING TO A PLEASANT NIGHT FRIDAY NIGHT. HOWEVER, HUMIDITY WILL BEGIN TO MAKE ITS RETURN TO MAINE LATE SATURDAY AS THE COLD FRONT SLOWLY MOVES BACK NORTH AS A WARM FRONT. NORTHERN AREAS WILL SEE A NICE SUMMER DAY ON SATURDAY WITH HIGHS AROUND 80 AND LOW HUMIDITY. MEANWHILE, DOWNEAST MAINE WILL SEE A RETURN TO MUCH WARMER AND MUGGIER CONDITIONS; HIGHS WILL BE IN THE MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE WARM FRONT LIFTS ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY AS LOW PRESSURE MOVES EASTWARD THROUGH THE GREAT LAKES. THIS SYSTEM WILL MOVE NORTH OF THE FORECAST AREA SUNDAY NIGHT INTO MONDAY, DRAGGING ITS ATTENDANT COLD FRONT ACROSS NEW ENGLAND AS IT DOES SO. AS SUCH, THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE LATE SUNDAY, BUT ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY. THIS FRONT WILL BE FOLLOWED BY A BRIEF RIDGE OF HIGH PRESSURE, BRINGING COOLER TEMPERATURES AND DRY WEATHER FOR MONDAY NIGHT AND TUESDAY. PRECIP CHANCES THEN INCREASE AGAIN BY MID WEEK AS ANOTHER FRONT MOVES INTO NORTHERN MAINE. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... NEAR TERM: CURRENTLY KBHB AND KBGR IFR W/ OUR REMAINING TAF SITES VFR... EXPECT SOME LOWER CIGS TO ARRIVE KHUL NEXT HR OR SO BUT AM NOT CONFIDENT THAT THESE CONDS WILL REACH OUR NRN TAF SITES ERLY THIS AM. FOR NOW WILL JUST ADVERTISE SOME MVFR UP N IN BR W/ CONFIDENCE LOW ATTM. MORE OF THE SAME TNGT W/ BEST THREAT OF IFR AT OUR SRN TAF SITES W/ LESSER CHCS N. SHORT TERM: VFR GENERALLY EXPECTED INTO EARLY NEXT WEEK, BUT MVFR CONDITIONS WILL BE POSSIBLE IN MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS FRIDAY AND MONDAY. && .MARINE... NEAR TERM: LGT SE SWELL CURRENTLY RESULTING IN SEAS AROUND 4 FT... SEAS GENERALLY EXPECTED TO REMAIN IN THE 3-5 FT RANGE THRU TNGT IN CONTG LGT SE SWELL W/ MAINLY LGT (<15 KT SRLY WNDS). NO HEADLINES ANTICIPATED THRU TNGT W/ AREAS OF FOG CONTG MAINLY DURING THE ERLY EVE THRU MID AM HRS... SHORT TERM: A COLD FRONT WILL MOVE ACROSS THE WATERS LATE FRIDAY. AHEAD OF THIS FRONT, WAVES WILL APPROACH 5 FT AS SOUTH WINDS INCREASE. RIGHT NOW THINGS LOOK MARGINAL, BUT LATER SHIFTS WILL HAVE TO MONITOR TRENDS AS A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS MAY BE NECESSARY FRIDAY. WAVES WILL SUBSIDE FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT; NO HEADLINES SHOULD BE NECESSARY THROUGH THE WEEKEND. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
333 PM CDT THU AUG 2 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY AFTERNOON. CONCERN IN THE NEXT 24 HRS WILL BE SLIGHT CHANCES FOR TSTMS EARLY ON ALONG WITH HIGH TEMPERATURES FOR FRIDAY. CURRENT WATER VAPOR IMAGERY ALONG WITH UPPER AIR AND WIND PROFILER DATA SHOW UPPER RIDGE NOW ANCHORED OVER TEXAS...AN UPPER LOW DROPPING SSE AND INTO THE WESTERN PART OF ALBERTA...PUTTING THE PLAINS IN WESTERLY FLOW. ONE CAN ALSO SEE THE SUBTROPICAL MOISTURE TAP STREAMING NORTH ACROSS WESTERN MEXICO...INTO THE FOUR CORNERS REGION AND THEN SWINGING EAST AROUND THE HIGH ACROSS OUR REGION. AT THE SURFACE...PRESSURE GRADIENT VERY WEAK ACROSS NEB/KS WITH ONE WEAK SURFACE LOW OVER OKLAHOMA AND ANOTHER ONE SITUATED ACROSS EASTERN MT/WY. SURFACE DEWPOINTS REMAIN FAIRLY HIGH OVER THE CWA RANGING FROM THE MID TO UPPER 60S AT LUNCHTIME. WEAK CONVECTIVE ACTIVITY HAS NEVER QUITE FADED AWAY IN OUR KS CWA ALTHOUGH DOUBT ANYTHING IS REACHING THE GROUND. CLOUD COVER ACROSS OUR SOUTHERN CWA HAS BEEN HOLDING IN A LITTLE LONGER THAN ANTICIPATED AND WITH SOME RE-DEVELOPMENT TO THE WEST...MAY NOT SEE HIGHS QUITE AS WARM AS EXPECT. ALSO WEAK CELLS MOVING ACROSS NORTHERN NEBRASKA HAVE ALSO HUNG IN DURING THE DAY. SOME OF THE HOURLY HRRR MODEL RUNS HAVE SHOWN THIS HANGING TOGETHER AND MOVING INTO THE WESTERN PART OF THE CWA LATER THIS AFTERNOON. WILL NEED TO MONITOR THIS OVER THE NEXT FEW HOURS. BELIEVE OUR BETTER...ALTHOUGH NOT GREAT...CHANCES FOR RAIN WILL BE LATER THIS EVENING AND OVERNIGHT. CHECKING OUT THE NEEDED INGREDIENTS...WE HAVE ADEQUATE INSTABILITY...MOISTURE AND SHEAR AT PRESENT BUT SEEM TO BE LACKING A FORCING MECHANISM. BELIEVE THE SURFACE TROUGH ALONG THE FRONT RANGE MAY FIT THE BILL AND WILL MONITOR CONVECTIVE DEVELOPMENT OUT WEST LATER THIS AFTERNOON. QUESTION THEN BECOMES WILL THIS ACTIVITY MAKE IT FAR ENOUGH EAST TO AFFECT OUR CWA. EARLY LOOK AT HRRR SHOWS THIS IS POSSIBLE AND WILL CHECK OUT THE 4KM WRF WHEN IT ARRIVES. SEEMS LIKE BETTER LOW LEVEL JET REMAINS WEST OVERNIGHT. ON FRIDAY AFTERNOON...THE UPPER LOW NOTED ABOVE WILL SHOULD BE CENTERED SOMEWHERE NEAR THE MT/NDAK/CANADA BORDER. THIS IS A DECENT WAVE AND SHOULD PROVIDE GOOD HEIGHT FALLS AND COOLER TEMPS ALOFT TO THE NORTHERN PLAINS. IT WILL ALSO PUSH A COLD FRONT INTO OUR NW CWA BY LATE AFTN OR EARLY EVENING. EXPECT SOME COMPRESSIONAL HEATING AHEAD OF THE FRONT AND WITH SURFACE WINDS BECOMING SOUTH TO SSW ANOTHER HOT DAY WILL BE IN STORE. DO NOT PLAN ON ISSUING ANY HEAT HEADLINES AS APPARENT TEMPERATURE VALUES FORECAST TO BE BETWEEN 98 AND 102 DEGREES IN THE SOUTHERN CWA. NOT SURE IF CONVECTION WILL BREAK OUT LATE FRIDAY AFTERNOON OR HOLD OFF UNTIL THE EVENING AS MOST MODELS SHOWING THE BULK OF THE PRECIPITATION BEING POST FRONTAL. IF I DO PUT IN AFTERNOON POPS...IT WILL MAINLY BE IN THE NORTHWEST AND WEST PART OF THE CWA. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. CONCERNS FOR THE MID AND LONG TERM PERIOD WILL AGAIN FOCUS ON CHANCES FOR THUNDERSTORMS AS WELL AS COOLER TEMPERATURES FOR THE WEEKEND. BEGINNING THE MID TERM PERIOD...THE MODELS REMAIN IN FAIRLY CONSISTENT AGREEMENT AS THE UPPER LEVEL LOW CONTINUES TO SHIFT EASTWARD ACROSS PORTIONS OF MONTANA AND NORTH DAKOTA. AT THE SURFACE...A LARGE AREA OF LOW PRESSURE ALSO CONTINUES TO PUSH EASTWARD...WITH AN ASSOCIATED COLD FRONTAL BOUNDARY KNOCKING ON OUR DOORSTEP BY FRIDAY EVENING. THUNDERSTORM CHANCES CONTINUE INTO THE OVERNIGHT HOURS...WITH THE POSSIBILITY OF A FEW STRONG STORMS IN THE EARLY EVENING. BY LATE SATURDAY MORNING...THE FRONTAL BOUNDARY SHOULD BEGIN TO SAG SOUTHEAST OUT OF THE REGION WITH LINGERING SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS ALONG THE ELEVATED BOUNDARY. WITH FRONTAL PASSAGE OVERNIGHT FRIDAY...HIGH PRESSURE AND COOLER TEMPERATURES WILL SINK INTO THE REGION ALONG WITH NORTH WINDS. MUCH COOLER 850 TEMPERATURES ON THE ORDER OF 10 DEGREES COOLER THAN PREVIOUS DAYS WILL HELP DRASTICALLY REDUCE HIGH TEMPERATURES. A VERY NICE WEEKEND IS IN STORE WITH HIGHS IN THE MID TO UPPER 80S. BY THE BEGINNING OF THE WORKWEEK...THE UPPER LEVEL RIDGE WILL BEGIN TO BUILD BACK IN ACROSS THE ROCKIES...RESULTING IN NORTHWEST FLOW THROUGH THE EXTENDED PERIOD. A DRY FORECAST IS EXPECTED THROUGH THE BEGINNING OF THE WORKWEEK AS THE CENTRAL PLAINS REMAIN UNDER SURFACE HIGH PRESSURE. HOWEVER...TOWARDS THE END OF THE PERIOD...A FEW SHORT WAVE PERTURBATIONS ROUND THE EASTERN EDGE OF THE UPPER LEVEL RIDGE...AND COMBINED WITH A SURFACE TROUGH AXIS ALONG THE FRONT RANGE WILL HELP GENERATE SOME CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. CONTINUED SLIGHT CHANCES THROUGH THE PERIOD...MONDAY AND AGAIN TUESDAY NIGHT THROUGH WEDNESDAY. AS FOR TEMPERATURES...ALTHOUGH MUCH OF THE WARMER 850 TEMPERATURES REMAIN FARTHER WEST ACROSS THE ROCKIES...EXPECT A RISE IN TEMPERATURES THROUGH THE WORKWEEK. CONTINUED WITH HIGHS IN THE MID TO UPPER 90S. && .PREV DISCUSSION... /ISSUED 1213 PM CDT THU AUG 2 2012/ AVIATION...EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE FORECAST PERIOD. THERE IS JUST A SLIGHT CHANCE FOR THUNDERSTORMS LATER THIS AFTERNOON AND INTO THE OVERNIGHT HOURS BUT LOOKS TO BE 20 PERCENT SO WILL LEAVE OUT OF TAF. OTHERWISE WINDS WILL REMAIN LIGHT FOR MOST OF THE PERIOD ALTHOUGH THEY SHOULD BEGIN TO PICK UP OUT OF THE SOUTH A BIT BY MID MORNING FRIDAY AS THE PRESSURE GRADIENT TIGHTENS UP WITH APPROACHING COLD FRONT MOVING IN FROM THE NORTHWEST. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...EWALD LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION...UPDATED
NWS OMAHA/VALLEY NE
1228 PM CDT THU AUG 2 2012 .UPDATE... && .AVIATION... 12Z TAFS FOR KOFK...KLNK AND KOMA. VFR CONDITIONS WILL PREVAIL THRU THE 24HR FCST PD. DEE PREV DISCUSSION... /ISSUED 348 AM CDT THU AUG 2 2012/ DISCUSSION... SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS INTO THE UPPER 90S IF NOT LOWER 100S. A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY 00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY. SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING. CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO SATURDAY MORNING. COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE 80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE BUILDS TO OUR WEST. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS TULSA OK
344 PM CDT THU AUG 2 2012 .DISCUSSION... ANOTHER OUTFLOW BOUNDARY STRIKES AGAIN. CONVECTION OVER KANSAS ONCE AGAIN SENT AN OUTFLOW BOUNDARY DOWN INTO OKLAHOMA EARLY THIS MORNING...AND IT HAS HAD SOME AFFECT ON TEMPS TODAY. BECAUSE OF THIS...IT DOES NOT APPEAR THAT THE ALL-TIME TEMP RECORD WILL BE REACHED AT TULSA. THE LATEST RUNS OF THE HRRR SUGGEST SOME ISOLATED TO WIDELY SCATTERED STORMS COULD DEVELOP ALONG THE EAST- WEST ORIENTED LOW LVL TROUGH/CONVERGENT ZONE LATE THIS AFTERNOON AND THIS EVENING. OTHER ELEVATED STORMS COULD DEVELOP ON THE EDGE OF THE CAP LATE TONIGHT TO OUR EAST. NAM MODEL 850MB DATA SUGGESTS THAT FRIDAY WILL BE ANOTHER SCORCHER...WITH HIGHS NEAR 110...ALTHOUGH CONVECTIVE OUTFLOW COULD AFFECT THIS LIKE IT HAS THE PAST COUPLE OF DAYS. SATURDAY IS SHAPING UP TO BE HOTTER DUE TO SOME COMPRESSIONAL WARMING AHEAD OF AN APPROACHING FRONT. SW WINDS WILL BE STRONGER AS WELL...AND THIS WILL REALLY INCREASE FIRE WEATHER CONCERNS. THE HEAT HEADLINES WILL CONTINUE ON THROUGH FRIDAY...HOWEVER THIS MAY NEED TO BE EXTENDED INTO SATURDAY IN LATER FORECASTS. STORMS THAT FORM ALONG THE FRONT IN KANSAS SATURDAY MAY MAKE THEIR WAY DOWN INTO OKLAHOMA AND ARKANSAS LATE SATURDAY AND SATURDAY NIGHT. MUCH COOLER...RELATIVELY SPEAKING...850MB TEMPS...MORE CLOUDS...AND HIGHER HUMIDITY WILL YIELD HIGHS BELOW 100 DEGREES ON SUNDAY. TEMPS WARM BACK UP NEXT WEEK INTO THE 100S...HOWEVER IT DOES APPEAR THAT THE REBUILDING RIDGE AND RESULTING HEAT WILL NOT BE AS INTENSE THIS GO AROUND. THERE MAY BE ANOTHER WEAK BOUNDARY BY NEXT THURSDAY OR SO...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INSERT POPS JUST YET. LACY && .PRELIMINARY POINT TEMPS/POPS... TUL 85 110 86 108 / 10 20 10 20 FSM 79 105 79 102 / 20 20 10 20 MLC 79 107 81 105 / 10 10 10 10 BVO 74 108 76 108 / 20 20 20 30 FYV 76 104 77 100 / 30 20 10 20 BYV 75 101 76 101 / 30 30 20 20 MKO 80 109 80 107 / 10 20 10 20 MIO 77 104 79 104 / 30 20 20 30 F10 80 112 79 107 / 10 10 10 10 HHW 78 104 78 99 / 10 10 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR OKZ054-OKZ055- OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ063- OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071- OKZ072-OKZ073-OKZ074. HEAT ADVISORY UNTIL 7 PM FRIDAY FOR OKZ049-OKZ053-OKZ075-OKZ076. AR...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR ARZ001-ARZ010- ARZ019-ARZ029. HEAT ADVISORY UNTIL 7 PM FRIDAY FOR ARZ002-ARZ011-ARZ020. && $$ LONG TERM....30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
352 PM EDT THU AUG 2 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH FRIDAY. A SOUTHWEST FLOW OF MORE HUMID AIR WILL DEVELOP FOR THE UPCOMING WEEKEND. A COLD FRONT WILL MOVE IN LATE SUNDAY OR EARLY MONDAY. THERE WILL BE A CHANCE OF SHOWERS OR STORMS...MAINLY THE LATER PART OF SUNDAY INTO EARLY MONDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LOW CLOUDS BURNED OFF NICELY ALLOWING US TO HEAT RAPIDLY TO OUR CONVECTIVE TEMP. AT THIS HOUR WE EVEN HAVE A FEW ISOLATED STORMS POPPING OFF OVER MY SERN ZONES WHERE RAP CAPES ARE ANALYZED OVER 3000J AND DEWPOINTS REMAIN NEAR 70 DEG. THE STORMS ARE FORMING ON THE BACK EDGE OF THE DEEPEST MOISTURE AND MOVING EAST...SO NOT EXPECTED TO AFFECT MORE THAN A FEW COUNTIES WITH LOCALIZED DOWNPOUR. AFTER THE SPOTTY CONVECTION DIES WITH THE LOSS OF HEATING...THE OVERNIGHT TONIGHT WILL ONCE AGAIN BE FAIR WITH SOME PATCHY FOG FORMING AROUND OR AFTER MIDNIGHT. LOWS IN THE 50S AND 60S WILL AVERAGE SEVERAL DEG ABOVE NORMAL. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... DRY WEATHER AND GENERALLY PTLY CLOUDY SKIES WITH LIGHT WIND WILL PERSIST THROUGH MOST OR ALL OF THIS PERIOD. THE NEARLY EAST/WEST AXIS OF STEEP MID LEVEL LAPSE RATES WILL STRETCH ACROSS THE NRN MTNS OF PENN FRIDAY AFTERNOON/EVENING. WEAK LLVL CONVERGENCE/OROGRAPHIC LIFT COULD SPARK A FEW TSRA AFTER 18Z...BUT AREAL COVERAGE IS ANTICIPATED TO BE QUITE LOW. HIGHS FRIDAY WILL TOP 90 OVER A GOOD DEAL OF THE AREA. AT THIS STAGE THE DEWPOINTS ARE JUST LOW ENOUGH TO NOT ALLOW HEAT INDICES TO TOP 100...BUT IT WILL BE CLOSE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... NOT A LOT OF CHANGE FROM RECENT DAYS. MAIN THING WAS TO UP TEMPS SOME ON MANY OF THE PERIODS...EVEN WITH THE RAINFALL...MAX TEMPS LIKELY TO BE WARMER THAN FCST. GFS HAS CLOSE TO A 579 THICKNESS ACROSS SE PA SUNDAY AFT. ALSO GUIDANCE MIN TEMPS BEEN TOO COLD LATELY...BFD LAST NIGHT WAS AN EXAMPLE OF THIS. SOME CHC FOR A SHOWER OR TSRA ACROSS THE AREA FRIDAY NIGHT... AND AGAIN LATER SATURDAY NIGHT AS THE BOUNDARY TO OUR SOUTH GRADUALLY RETURNS NORTH AS A WARM FRONT...AND THE FAVORABLE LEFT EXIT REGION OF AN UPPER JET HEADS SE FROM THE GLAKES REGION. BEST CHC FOR SEVERE SUNDAY WILL BE NORTH CENTRAL PA AND THE SUSQUEHANNA VLY. NORTHERN PA WILL BE NEAR THE SOUTHERN EDGE OF THE BETTER DYANMICS. ACROSS EASTERN PA...THE LEE TROUGH WILL LIKELY TO FORM IN EASTERN PA...AIDING THE FORMATION OF STORMS SUNDAY AFTERNOON AND EVENING. I DID SLOW TIMING OF FRONT DOWN SOME...THUS A LITTLE MORE CLDS AND THREAT OF SHOWERS AND STORMS INTO MONDAY ACROSS S PA. NOT SEEING MUCH OF A COOL DOWN FOR NEXT WEEK...TEMPS NEAR OR JUST ABOVE NORMAL. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... ALL SITES HAVE IMPROVED TO VFR AND WILL REMAIN THAT WAY INTO THE OVERNIGHT. ONLY POSSIBLE COMPLICATION IS IF A STRAY STORM POPS UP NEAR OUR SERN TERMINALS FOR THE NEXT FEW HOURS. THE ACTIVITY IS VERY ISOLATED SO PROBABILITIES WILL BE LOW. OVERNIGHT WILL ONCE AGAIN FEATURE PATCHY FOG AND LOW CLOUDS WITH SOME MVFR/IFR POSSIBLE...ESPECIALLY AROUND SUNRISE. EXPECT RAPID IMPROVEMENT TO VFR BY MID MORNING FRIDAY UNDER THE STRONG SUMMER SUN. ONLY CONCERN FOR FRIDAY WILL BE THE POTENTIAL FOR MORE ISOLATED POP UP DIURNAL CONVECTION. NO REAL WEATHER FEATURE PASSING THROUGH SO IT WILL BE BASICALLY DAY TIME HEATING AS A TRIGGER. OUTLOOK... .FRI-SUN...MAINLY VFR...BUT WITH DIURNAL CONVECTION POSSIBLY CAUSING LOCALIZED REDUCED CONDITIONS...MAINLY THE LATER HALF OF SUNDAY .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
203 PM EDT THU AUG 2 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH FRIDAY. A SOUTHWEST FLOW OF MORE HUMID AIR WILL DEVELOP FOR THE UPCOMING WEEKEND. A COLD FRONT WILL MOVE IN LATE SUNDAY OR EARLY MONDAY. THERE WILL BE A CHANCE OF SHOWERS OR STORMS...MAINLY THE LATER PART OF SUNDAY INTO EARLY MONDAY. && .NEAR TERM /THROUGH TONIGHT/... LOW CLOUDS BURNED OFF NICELY ALLOWING US TO HEAT RAPIDLY TO OUR CONVECTIVE TEMP. AT THIS HOUR WE EVEN HAVE A FEW ISOLATED STORMS POPPING OFF OVER MY SERN ZONES WHERE RAP CAPES ARE ANALYZED OVER 3000J AND DEWPOINTS REMAIN NEAR 70 DEG. THE STORMS ARE FORMING ON THE BACK EDGE OF THE DEEPEST MOISTURE AND MOVING EAST...SO NOT EXPECTED TO AFFECT MORE THAN A FEW COUNTIES WITH LOCALIZED DOWNPOUR. AFTER THE SPOTTY CONVECTION DIES WITH THE LOSS OF HEATING...THE OVERNIGHT TONIGHT WILL ONCE AGAIN BE FAIR WITH SOME PATCHY FOG FORMING AROUND OR AFTER MIDNIGHT. LOWS IN THE 50S AND 60S WILL AVERAGE SEVERAL DEG ABOVE NORMAL. && .SHORT TERM /FRIDAY/... DRY WEATHER AND GENERALLY PTLY CLOUDY SKIES WITH LIGHT WIND WILL PERSIST THROUGH MOST OR ALL OF THIS PERIOD. THE NEARLY EAST/WEST AXIS OF STEEP MID LEVEL LAPSE RATES WILL STRETCH ACROSS THE NRN MTNS OF PENN FRIDAY AFTERNOON/EVENING. WEAK LLVL CONVERGENCE/OROGRAPHIC LIFT COULD SPARK A FEW TSRA AFTER 18Z...BUT AREAL COVERAGE IS ANTICIPATED TO BE QUITE LOW. HIGHS FRIDAY WILL TOP 90 OVER A GOOD DEAL OF THE AREA. AT THIS STAGE THE DEWPOINTS ARE JUST LOW ENOUGH TO NOT ALLOW HEAT INDICES TO TOP 100...BUT IT WILL BE CLOSE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... SOME CHC FOR A SHOWER OR TSRA ACROSS THE ENTIRE AREA FRIDAY NIGHT INTO SATURDAY NIGHT AS THE BOUNDARY TO OUR SOUTH GRADUALLY RETURNS NORTH AS A WARM FRONT...AND THE FAVORABLE LEFT EXIT REGION OF AN UPPER JET HEADS SE FROM THE GLAKES REGION. THERE/S A BETTER CHC FOR MORE WIDESPREAD AND STRONGER CONVECTION SATURDAY AFTERNOON AND EVENING...ESPECIALLY ACROSS THE WRN HALF OF PENN WHERE THE LATEST SREF PAINTS SFC-BASED CAPES OF 1500-1800 J/KG COINCIDING WITH A BELT OF ANOMALOUSLY STG SOUTHERLY 850 MB WINDS OF PLUS 2-3 ST DEVIATIONS. THIS SRLY LL JET PEAKS AROUND 30 KTS AT 03Z SUNDAY BEFORE LIFTING NORTH INTO NEW YORK STATE LATER SUNDAY MORNING. A SHARP INCREASE IN LLVL MOISTURE/PRECIPITABLE WATER WILL OCCUR LATE FRIDAY NIGHT THROUGH SATURDAY. PWATS WILL AVERAGE 1.5-2 INCHES ACROSS THE STATE SATURDAY AFTERNOON AND EVENING. THE ASSOCIATED 850 MB MOISTURE FLUX WILL ALSO DISPLAY A STRONG SIGNAL FOR POTENTIALLY SEVERE TSRA AS IT REACHES 2-3 ST DEVIATIONS ABOVE NORMAL ACROSS ALL OF THE FCST AREA AT 00Z SUNDAY. SUNDAY AFTERNOON AND EVENING WILL LIKELY BRING ANOTHER BOUT OF SCTD-NUMEROUS SHOWERS/TSRA...SOME POTENTIALLY SVR AS A STRONG COLD FRONT PLOWS EAST FROM THE OHIO VALLEY. THE CORE OF STRONGER AND SLIGHTLY LESS ANOMALOUS...925-850 MB WINDS SHIFTS TO OUR FAR EASTERN ZONES AND TURNS MORE TO A SWRLY DIRECTION DURING THE DAY SUNDAY . SFC TEMP/DEWPOINT SPREADS ARE PROGGED TO BE APPRECIABLY LOWER SUNDAY...POSSIBLY DUE TO SOME EARLY MORNING CONVECTION/MCS REMNANTS AND LINGERING MORNING/MIDDAY CLOUD COVER. IN ANY CASE...THE TARGET AREA FOR THE GREATEST CONCENTRATION OF TSRA WILL SHIFT TO THE CENTRAL MTNS AND SUSQ VALLEY SUNDAY AFTERNOON AND EVENING...WHERE THE 0-1KM ENERGY/HELICITY INDEX WILL CLIMB TO AROUND 2-2.5 M2/S2. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... ALL SITES HAVE IMPROVED TO VFR AND WILL REMAIN THAT WAY INTO THE OVERNIGHT. ONLY POSSIBLE COMPLICATION IS IF A STRAY STORM POPS UP NEAR OUR SERN TERMINALS FOR THE NEXT FEW HOURS. THE ACTIVITY IS VERY ISOLATED SO PROBABILITIES WILL BE LOW. OVERNIGHT WILL ONCE AGAIN FEATURE PATCHY FOG AND LOW CLOUDS WITH SOME MVFR/IFR POSSIBLE...ESPECIALLY AROUND SUNRISE. EXPECT RAPID IMPROVEMENT TO VFR BY MID MORNING FRIDAY UNDER THE STRONG SUMMER SUN. ONLY CONCERN FOR FRIDAY WILL BE THE POTENTIAL FOR MORE ISOLATED POP UP DIURNAL CONVECTION. NO REAL WEATHER FEATURE PASSING THROUGH SO IT WILL BE BASICALLY DAY TIME HEATING AS A TRIGGER. OUTLOOK... .FRI-SUN...MAINLY VFR...BUT WITH DIURNAL CONVECTION POSSIBLY CAUSING LOCALIZED REDUCED CONDITIONS...MAINLY THE LATER HALF OF SUNDAY .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
126 PM CDT THU AUG 2 2012 .DISCUSSION... UPDATED FOR 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 1136 AM CDT THU AUG 2 2012/ UPDATE... WENT AHEAD AND BUMPED UP POPS ACROSS THE NORTHEAST HALF OF CWA DUE TO THE THUNDERSTORM ACTIVITY BEGINNING TO POP UP NEAR POPLAR BLUFF MISSOURI INTO CLAY COUNTY ARKANSAS. KRM PREV DISCUSSION... /ISSUED 1030 AM CDT THU AUG 2 2012/ REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND NOON TO REMOVE MORNING WORDING. KRM DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/ FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S. ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR AN AFTERNOON SHOWER OR STORM. THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT. THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A FEW SEVERE STORMS. NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S. HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED. SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES. THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY SUNNIER SKIES. EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE LOW TO MID 90S. JAB && .AVIATION... EARLIER SHOWERS AND THUNDERSTORMS HAVE WORKED OVER THE AIRMASS ACROSS AT LEAST THE WESTERN HALF OF THE MID SOUTH. RECENT RADAR TRENDS HAVE BEEN UNIMPRESSIVE AND THE CU FIELD IS STRUGGLING TO DEVELOP. LOOKS LIKE THE BEST CHANCE FOR TSRAS THIS AFTN WILL BE AT KTUP. ELSW CHANCES ARE LOW ENOUGH TO REMOVE THE VCTS FOR THE REST OF THE AFTN. THE NEXT UPPER LEVEL DISTURBANCE...LOCATED OVER NRN MO ATTM...WILL TRIGGER ANOTHER ROUND OF TSRAS THIS AFTERNOON THAT WILL MOVE INTO THE MIDSOUTH THIS EVENING AND OVERNIGHT. ADJUSTED VCTS TIMING TO REFLECT THIS THINKING. WINDS WILL GENERALLY BE S/SW AT 8-12 KTS THIS AFTERNOON...DIMINISHING THIS EVENING. SJM && .PRELIMINARY POINT TEMPS/POPS... MEM 96 79 93 77 / 30 40 40 20 MKL 96 73 88 74 / 40 60 50 20 JBR 96 74 95 75 / 40 50 40 30 TUP 95 76 90 74 / 30 20 50 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL- MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO- TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1136 AM CDT THU AUG 2 2012 .UPDATE... WENT AHEAD AND BUMPED UP POPS ACROSS THE NORTHEAST HALF OF CWA DUE TO THE THUNDERSTORM ACTIVITY BEGINNING TO POP UP NEAR POPLAR BLUFF MISSOURI INTO CLAY COUNTY ARKANSAS. KRM && .PREV DISCUSSION... /ISSUED 1030 AM CDT THU AUG 2 2012/ REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND NOON TO REMOVE MORNING WORDING. KRM && .DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/ FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S. ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR AN AFTERNOON SHOWER OR STORM. THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT. THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A FEW SEVERE STORMS. NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S. HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED. SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES. THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY SUNNIER SKIES. EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE LOW TO MID 90S. JAB && .AVIATION... 12Z TAF CYCLE (02/12Z-03/12Z) SHOWERS AND THUNDERSTORMS IN A BAND ACROSS PORTIONS OF EASTERN AR HAVE BEEN MOVING MAINLY NORTH TO SOUTH EARLIER THIS MORNING...REMAINING WEST OF KJBR. DID MENTION VCSH AT KJBR UNTIL 15Z AND WILL MONITOR FOR AMENDING TO ADD VCTS IF THE ACTIVITY DOES CREEP FURTHER EASTWARD. OTHERWISE VFR CONDITIONS ARE EXPECTED TO PREVAIL MOST OF THE PERIOD AT THE TAF SITES. CONTINUED MENTION OF VCTS AT ALL THE TAF SITES THIS AFTERNOON AND EARLY EVENING WITH DAYTIME HEATING. MODELS INDICATE A MESOSCALE CONVECTION SYSTEM MAY MOVE INTO THE REGION FROM THE NORTH LATE TONIGHT...FOR NOW INCLUDED VCTS AT KJBR AND KMKL AFTER 03/06Z AND AT KMEM AFTER 03/09Z. WINDS MAINLY S TO SW BECOMING 8-12 KTS TODAY...WINDS TONIGHT SOUTHERLY 4-8 KTS. JCL && && .PRELIMINARY POINT TEMPS/POPS... MEM 96 76 94 77 / 30 20 40 20 MKL 96 73 90 74 / 40 40 50 20 JBR 96 75 93 75 / 40 20 40 10 TUP 95 74 91 73 / 30 40 50 20 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL- MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO- TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT THU AUG 2 2012 .SHORT TERM... 334 PM CDT THU AUG 2 2012 OVERALL NOT MANY CHANGES TO THE ONGOING FORECAST. SIGHTS ARE ON SATURDAY SYSTEM MOVING THROUGH THE REGION WITH SEVERE WEATHER THREAT STILL LOOKING LIKE EASTERN PART OF WI. 02.12Z RAOB DATA SUGGESTS THE TAIL OF TWO AIR MASSES BETWEEN KMPX AND KDVN. KDVN IS REMARKABLY DRY AND THIS IS LEADING TO THE DEW POINT CRASHES INTO THE 50S SEEN NEAR KDBQ AND SOUTH AS MIXING HAS INCREASED THIS AFTERNOON. STILL A WEAKLY CONVERGENCE FLOW IN LOW-LEVELS ALONG AN INVERTED TROUGH FROM NEAR KDLL-KOVS-KMCW. SOME CUMULUS LOOKING MORE ENHANCED...WITH MLCAPE IN THE 1500 J/KG RANGE. MORE SIGNIFICANT TROUGH EXPECTED TO AFFECT THE REGION SATURDAY IS SEEN IN GOES WATER VAPOR OVER BRITISH COLUMBIA AND ALBERTA WITH A TROPOPAUSE LEVEL DOWN TO 500 MB PER THE 02.19Z RAP ANALYSIS. CONVECTION ALREADY BECOMING ACTIVE DOWNSTREAM OVER WY/MT/ND IN THE DIFFLUENT FLOW AND HEIGHT FALL REGION. WITH SUCH WEAK CONVERGENCE AND MID-UPPER LEVEL SUPPORT THIS EVENING ACROSS NE IA AND SWRN WI...HAVE DECIDED TO KEEP IT DRY THIS EVENING ACROSS THE SOUTH. LATEST HRRR RUNS ARE SLIGHTLY LIGHTER WITH CONVECTIVE CELL DEVELOPMENT DOWN THERE...MORE TOWARD AN ENHANCED CUMULUS SOLUTION. HRRR SUGGESTS THE INVERTED TROUGH OVER ERN WI MORE VIGOROUS IN EVENING. THERE COULD BE A STORM OR TWO THAT DEVELOP BUT WE DO NOT SEE IT AS ENOUGH TO ADD IT TO THE FORECAST ACROSS OUR FORECAST AREA. EVENING FORECASTER CAN MONITOR. FRIDAY APPEARS TO BE A NICE DAY WITH THE RIDGE BUILDING IN FROM THE GREAT LAKES AND SE FLOW IN THE LOW-LEVELS. WILL NEED TO BE WATCHING THE SYSTEM TO THE SOUTH WHICH IS CUTOFF FROM THE MAIN FLOW AND HAS SOME CAPE BUILDING ACROSS IL AND MOISTURE TRANSPORT HAS SOME SIGNAL OF CONVERGENCE ACROSS NORTHERN IL. THIS MAY BRING SOME SHRA ACTIVITY NEAR SOUTHERN WI AND THE FORECAST AREA. IDEA IS THAT DEWPOINTS ARE PROBABLY OVERFORECAST IN THE GUIDANCE WITH SUCH A DRY AIR MASS IN PLACE. LARGER SCALE TROUGH MOVING EAST INTO THE NORTHERN PLAINS ON FRIDAY WILL INITIATE CONVECTION IN THE DAKOTAS THAT WILL ROLL EAST OVERNIGHT ON MOISTURE TRANSPORT AND DYNAMICS. STILL HAVE SOME LIMITED CAPE TO THE WEST OVERNIGHT TO SUGGEST A DECAYING TSRA/SHRA ACROSS MN/IA POSSIBLY AFFECTING SERN MN/WRN MN LATE FRIDAY NIGHT. HAVE INCREASED RAIN CHANCES A BIT FOR THOSE AREAS AFTER MIDNIGHT. IN THE BIG PICTURE...THE 02.12Z NAM/GEM/GFS/ECMWF ARE IN AGREEMENT ON THE TIMING OF THE LARGER SCALE TROUGH MOVING ACROSS THE GREAT LAKES SATURDAY AND SATURDAY NIGHT. THE DETAILS ARE DIFFERENT HOWEVER WITH THE 02.12Z NAM SUGGESTING A SIMILAR IDEA AS THE 02.00Z/12Z ECMWF OF A SECONDARY SURFACE LOW MOVING NE ALONG THE FRONT SATURDAY TOWARD KMKE FROM IL. THE EC SOLUTIONS ARENT QUITE AS AGGRESSIVE AS THE NAM WITH THE STRENGTH OF THE SECOND LOW...BUT THEY HAVE SIMILAR SENSIBLE WEATHER OUTCOMES BUT LESS RAINFALL. THIS LOW SHIFTING NE WOULD ELICIT A GREATER CHANCE OF RAIN EAST OF THE MISS RIVER FOR SATURDAY AND SLOW THE EASTWARD MOVING COLD FRONT AND DRYING TO ALLOW MORE RAIN SATURDAY EVENING IN CENTRAL WI. EVEN WITH THESE DIFFERENCE IN THE DEVELOPMENT OF A SECONDARY LOW...THE CONSENSUS CAPE IS MAINLY EAST OF THE FORECAST AREA FOR A SATURDAY SEVERE WEATHER THREAT. THIS AGREES WITH THE SPC DAY 3 SLIGHT RISK FOR EASTERN WI. ANALYSIS OF THE SOUNDINGS OVER THE FORECAST AREA SUGGEST THAT ELEVATED INSTABILITY IS REALLY THE ONLY TSRA THREAT WITH THE LOWEST CIN VALUES AROUND 100 J/KG LATE MORNING IN SWRN WI PER 02.12Z NAM. 02.12Z GFS A BIT SLOWER WITH FRONT ALLOWING A BIT MORE WARMING AND INSTABILITY...WITH ML CAPE IN THE 1800 J/KG AREA AND CIN NEAR 50 J/KG. SO...THE MAIN THREAT DOES APPEAR TO BE EAST. BUT...ANY SLOWING TO THE FRONT WOULD ALLOW SWRN-CENTRAL WI TO GET INTO A WIND AND HAIL THREAT. HAVE INCREASED RAIN CHANCES FOR SATURDAY A BIT MORE AND LOWERED HIGH TEMPERATURES BY 3-5F WITH MORE CLOUD. ALSO HAVE INCREASED RAIN CHANCES A BIT WESTWARD SATURDAY EVENING TO ALLOW FOR A SLOWER SECONDARY LOW DEVELOPMENT ALONG THE FRONT. THE 02.12Z ECMWF HAS TAKEN ABOUT A 4-6 HOUR STEP SLOWER THAN THE PREVIOUS RUN...SO SEVERE WEATHER FOR WESTERN WI IS STILL NOT RULED OUT. .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY 335 PM CDT THU AUG 2 2012 A DRIER PERIOD IS SEEN HERE AS THE LARGE SCALE TROUGH DEEPENS OVER HUDSONS BAY AND IMPACTS THE WESTERN GREAT LAKES WITH LOWER HEIGHTS AND NORTHWEST FLOW. 02.12Z ECMWF IS MORE AGGRESSIVE WITH THE TROUGH DEPTH OVER THE AREA SUGGESTING A BIT COOLER THAN THE 02.12Z GFS. THE 02.12Z GEM WOULD AGREE MORE ON THE GFS SIDE...HOWEVER IT MAY BE OFF IN ITS TIMING AS IT HAS A DEEPER SHORTWAVE TROUGH ROTATING SOUTHWARD ABOUT 24 HOURS AFTER THE 02.12Z ECMWF SOLUTION. IN EITHER CASE...THE SENSIBLE WEATHER IS MAINLY A COOLER FORECAST IN THE ECMWF. THUS...HAVE TAKEN A FEW DEGREES OFF A CONSENSUS FORECAST. THE 02.00Z GFS ENSEMBLE DATA DID SHOW HIGHER SIGNS OF SPREAD IN THE MID-WEEK HIGHS WITH A 78-87F RANGE...AND THE OPERATIONAL GFS MOS WAS ON THE WARM SIDE. STILL THINK THE 02.12Z GFS IS ON THE WARM SIDE AND HAVE UNDERCUT THOSE VALUES. FORECAST TEMPERATURES WILL BE PLEASANT AND NEAR NORMAL. PRECIPITATION CHANCES ARE SMALL THROUGH THE WEEK AND HARD TO TIME OUT AT THIS POINT. && .AVIATION... 600 PM CDT THU AUG 2 2012 HIGH PRESSURE OVER SOUTHEAST CANADA WILL BE THE MAIN WEATHER INFLUENCE FOR THE REGION TONIGHT...RESULTING IN MOSTLY CLEAR SKIES AND LIGHT SFC WINDS. ADD RAINS FROM LAST NIGHT/EARLY THIS MORNING AND THE SETUP WOULD SEEM CONDUCIVE TO AREAS OF FOG. HOWEVER...BUFKIT RAP/NAM12 WIND FIELDS FAVOR AROUND 10 KTS WITHIN THE FIRST COUPLE HUNDRED FEET TONIGHT...AN INHIBITOR TO WIDESPREAD FOG. AFTERNOON SUNSHINE HAS ALSO LED TO A QUICK BUMP UPWARD IN THE TEMPS...AND MIXING RESULTING IN DRYING OF THE SFC TD. LARGER T/TD SPREAD TO OVERCOME TONIGHT AS A RESULT. WILL STAY WITH 5SM BR MENTION IN TAFS FOR NOW AND MONITOR TRENDS THROUGH THE EVENING. THINK THE GREATER THREAT FOR SUB 1SM WOULD LIE IN THE RIVER VALLEYS...AND THUS AT KLSE. VFR CONDITIONS SHOULD ABOUND FOR MOST OF FRIDAY...WITH SOME INCREASING CLOUDS FROM THE WEST IN THE EVENING...AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT WILL BRING SOME SHRA/TS CHANCES...MOSTLY AFTER 12Z SAT. && .ARX WATCHES/WARNINGS/ADVISORIES... 335 PM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM....BAUMGARDT AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
354 PM CDT THU AUG 2 2012 .SHORT TERM... TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM. AREA OF RAIN SHOWERS CONTINUES TO SHIFT EAST ACROSS THE NORTHERN COUNTIES OF THE FORECAST AREA. THIS AREA AIDED BY MODEST 850MB/700MB MOISTURE POOLING/CONVERGENCE AND LOW LEVEL FRONTOGENESIS RESPONSE. THIS AREA SHOULD CONTINUE TO SHIFT EASTWARD THROUGH THE REST OF THE AFTERNOON ACROSS THE NORTHEAST COUNTIES...ALONG WITH ASSOCIATED UPWARD VERTICAL MOTION. WEAK COLD FRONT FROM WEST CENTRAL TO NORTHEAST WISCONSIN IS EXPECTED TO SAG SOUTHWARD THROUGH THE AREA THIS EVENING...THEN TO THE SOUTH LATER TONIGHT. AREA OF WEAK TO MODEST 850MB CONFLUENCE ALSO SHIFTS SOUTH INTO THE AREA AND LINGERS THROUGH THE NIGHT. AREA FORECAST SOUNDINGS SHOWING CAP MIXING OUT ACROSS SOUTHERN PORTIONS OF THE AREA WHERE CLOUDS MOVED AWAY...WITH AROUND 500 J/KG MEAN LAYER CAPE. CLOUDIER AREAS WOULD HAVE LESS CAPE AND MORE CAPPING. CAPE BECOMES MORE ELEVATED TONIGHT AND WOULD HAVE TO BE REACHED BY ELEVATED PARCELS. HRRR MODEL SHOWING WIDELY SCATTERED CELLS AT BEST DEVELOPING LATE THIS AFTERNOON INTO THE EARLY EVENING. KEPT POPS FOR LATE THIS AFTERNOON INTO TONIGHT WITH THE ABOVE FORCING MECHANISMS MOVING IN. A GOOD PORTION OF THE AREA LIKELY WILL BE DRY. SCATTERED MID LEVEL CLOUDS EXPECTED TONIGHT INTO FRIDAY. DRIER AIR WORKS INTO THE AREA FRIDAY ON EASTERLY WINDS. KEPT DRY FORECAST GOING FOR FRIDAY WITH DECENT CAP ACROSS THE AREA. LOWS TONIGHT SHOULD FALL TO THE MID TO UPPER 60S...WITH ANOTHER VERY WARM DAY IN THE UPPER 80S TO LOWER 90S AWAY FROM THE LAKE. EAST WINDS KEEPS HIGHS COOLER NEAR LAKESHORE. FRIDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM TO HIGH A FAIRLY SHARP UPPER TROUGH WILL TRACK EWD FROM THE NRN HIGH PLAINS THROUGH THE GREAT LAKES DURING THIS PERIOD WITH AN ORGANIZED LOW PRESSURE AREA MOVING ALONG THE US/CANADIAN BORDER. THETAE ADVECTION WILL BOOST PWS TO NEARLY ONE INCH FOR SAT AFTERNOON AND EVENING AHEAD OF AND ALONG THE COLD FRONT ALONG WITH MODERATE INSTABILITY AND WIND SHEAR. THUNDERSTORMS WILL LIKELY DEVELOP SAT AFTERNOON OVER WRN WI AND THEN MOVE EWD THROUGH SAT EVENING. A SLIGHT RISK OF SEVERE THUNDERSTORMS IS FORECAST BY SPC AND LOOKS GOOD. COLD AND DRY ADVECTION WILL THEN PREVAIL ON SUNDAY WITH A PLEASANT DAY FOLLOWED BY HIGH PRESSURE THROUGH MON NT. .LONG TERM... SRN WI WILL BE ON THE SRN PERIPHERY OF NW FLOW WITH ONLY A WEAK COOL FRONT TO POSSIBLY BE IN THE VICINITY OF SRN WI FROM TUE-WED. THUS ONLY SLIGHT CHANCE OF TSTORMS DURING THAT TIME. TEMPS WILL BE AT LEAST SLIGHTLY ABOVE NORMAL NEXT WEEK. && .AVIATION/00Z TAFS/... VFR CONDITIONS EXPECTED THROUGH FRIDAY ACROSS TAF SITES. CURRENT SHOWER ACTIVITY WILL CONTINUE TO REMAIN NORTH OF TAF SITES. EXPECT SCATTERED TO BROKEN MID LEVEL CLOUDS THROUGH THE LATE AFTERNOON. EAST/SOUTHEAST WINDS ARE EXPECTED TO LINGER AT MILWAUKEE AND REACH WAUKESHA BY 22Z. LIGHT WINDS ARE EXPECTED TO LINGER AT MADISON. WEAK COLD FRONT SLIDING SOUTH TOWARD THE AREA LATE THIS AFTERNOON...AND THROUGH THE AREA THIS EVENING. FRONT WOULD BRING MAINLY SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE EVENING...AND A SHOWER AFTER MIDNIGHT. HOWEVER...TOO MUCH UNCERTAINTY RIGHT NOW TO MENTION IN TAFS. LIGHT EAST TO NORTHEAST WINDS TONIGHT SHOULD REMAIN EASTERLY ON FRIDAY ACROSS TAF SITES...WITH FEW TO SCATTERED MID LEVEL CLOUDS. EASTERLY WINDS BRING DRIER AIR INTO THE AREA LATER TONIGHT AND FRIDAY...WITH QUIET WEATHER EXPECTED. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD FRIDAY NIGHT THROUGH THURSDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
335 PM CDT THU AUG 2 2012 .SHORT TERM... 334 PM CDT THU AUG 2 2012 OVERALL NOT MANY CHANGES TO THE ONGOING FORECAST. SIGHTS ARE ON SATURDAY SYSTEM MOVING THROUGH THE REGION WITH SEVERE WEATHER THREAT STILL LOOKING LIKE EASTERN PART OF WI. 02.12Z RAOB DATA SUGGESTS THE TAIL OF TWO AIR MASSES BETWEEN KMPX AND KDVN. KDVN IS REMARKABLY DRY AND THIS IS LEADING TO THE DEW POINT CRASHES INTO THE 50S SEEN NEAR KDBQ AND SOUTH AS MIXING HAS INCREASED THIS AFTERNOON. STILL A WEAKLY CONVERGENCE FLOW IN LOW- LEVELS ALONG AN INVERTED TROUGH FROM NEAR KDLL-KOVS-KMCW. SOME CUMULUS LOOKING MORE ENHANCED...WITH MLCAPE IN THE 1500 J/KG RANGE. MORE SIGNIFICANT TROUGH EXPECTED TO AFFECT THE REGION SATURDAY IS SEEN IN GOES WATER VAPOR OVER BRITISH COLUMBIA AND ALBERTA WITH A TROPOPAUSE LEVEL DOWN TO 500 MB PER THE 02.19Z RAP ANALYSIS. CONVECTION ALREADY BECOMING ACTIVE DOWNSTREAM OVER WY/MT/ND IN THE DIFFLUENT FLOW AND HEIGHT FALL REGION. WITH SUCH WEAK CONVERGENCE AND MID-UPPER LEVEL SUPPORT THIS EVENING ACROSS NE IA AND SWRN WI...HAVE DECIDED TO KEEP IT DRY THIS EVENING ACROSS THE SOUTH. LATEST HRRR RUNS ARE SLIGHTLY LIGHTER WITH CONVECTIVE CELL DEVELOPMENT DOWN THERE...MORE TOWARD AN ENHANCED CUMULUS SOLUTION. HRRR SUGGESTS THE INVERTED TROUGH OVER ERN WI MORE VIGOROUS IN EVENING. THERE COULD BE A STORM OR TWO THAT DEVELOP BUT WE DO NOT SEE IT AS ENOUGH TO ADD IT TO THE FORECAST ACROSS OUR FORECAST AREA. EVENING FORECASTER CAN MONITOR. FRIDAY APPEARS TO BE A NICE DAY WITH THE RIDGE BUILDING IN FROM THE GREAT LAKES AND SE FLOW IN THE LOW-LEVELS. WILL NEED TO BE WATCHING THE SYSTEM TO THE SOUTH WHICH IS CUTOFF FROM THE MAIN FLOW AND HAS SOME CAPE BUILDING ACROSS IL AND MOISTURE TRANSPORT HAS SOME SIGNAL OF CONVERGENCE ACROSS NORTHERN IL. THIS MAY BRING SOME SHRA ACTIVITY NEAR SOUTHERN WI AND THE FORECAST AREA. IDEA IS THAT DEWPOINTS ARE PROBABLY OVERFORECAST IN THE GUIDANCE WITH SUCH A DRY AIR MASS IN PLACE. LARGER SCALE TROUGH MOVING EAST INTO THE NORTHERN PLAINS ON FRIDAY WILL INITIATE CONVECTION IN THE DAKOTAS THAT WILL ROLL EAST OVERNIGHT ON MOISTURE TRANSPORT AND DYNAMICS. STILL HAVE SOME LIMITED CAPE TO THE WEST OVERNIGHT TO SUGGEST A DECAYING TSRA/SHRA ACROSS MN/IA POSSIBLY AFFECTING SERN MN/WRN MN LATE FRIDAY NIGHT. HAVE INCREASED RAIN CHANCES A BIT FOR THOSE AREAS AFTER MIDNIGHT. IN THE BIG PICTURE...THE 02.12Z NAM/GEM/GFS/ECMWF ARE IN AGREEMENT ON THE TIMING OF THE LARGER SCALE TROUGH MOVING ACROSS THE GREAT LAKES SATURDAY AND SATURDAY NIGHT. THE DETAILS ARE DIFFERENT HOWEVER WITH THE 02.12Z NAM SUGGESTING A SIMILAR IDEA AS THE 02.00Z/12Z ECMWF OF A SECONDARY SURFACE LOW MOVING NE ALONG THE FRONT SATURDAY TOWARD KMKE FROM IL. THE EC SOLUTIONS ARENT QUITE AS AGGRESSIVE AS THE NAM WITH THE STRENGTH OF THE SECOND LOW...BUT THEY HAVE SIMILAR SENSIBLE WEATHER OUTCOMES BUT LESS RAINFALL. THIS LOW SHIFTING NE WOULD ELICIT A GREATER CHANCE OF RAIN EAST OF THE MISS RIVER FOR SATURDAY AND SLOW THE EASTWARD MOVING COLD FRONT AND DRYING TO ALLOW MORE RAIN SATURDAY EVENING IN CENTRAL WI. EVEN WITH THESE DIFFERENCE IN THE DEVELOPMENT OF A SECONDARY LOW...THE CONSENSUS CAPE IS MAINLY EAST OF THE FORECAST AREA FOR A SATURDAY SEVERE WEATHER THREAT. THIS AGREES WITH THE SPC DAY 3 SLIGHT RISK FOR EASTERN WI. ANALYSIS OF THE SOUNDINGS OVER THE FORECAST AREA SUGGEST THAT ELEVATED INSTABILITY IS REALLY THE ONLY TSRA THREAT WITH THE LOWEST CIN VALUES AROUND 100 J/KG LATE MORNING IN SWRN WI PER 02.12Z NAM. 02.12Z GFS A BIT SLOWER WITH FRONT ALLOWING A BIT MORE WARMING AND INSTABILITY...WITH ML CAPE IN THE 1800 J/KG AREA AND CIN NEAR 50 J/KG. SO...THE MAIN THREAT DOES APPEAR TO BE EAST. BUT...ANY SLOWING TO THE FRONT WOULD ALLOW SWRN-CENTRAL WI TO GET INTO A WIND AND HAIL THREAT. HAVE INCREASED RAIN CHANCES FOR SATURDAY A BIT MORE AND LOWERED HIGH TEMPERATURES BY 3-5F WITH MORE CLOUD. ALSO HAVE INCREASED RAIN CHANCES A BIT WESTWARD SATURDAY EVENING TO ALLOW FOR A SLOWER SECONDARY LOW DEVELOPMENT ALONG THE FRONT. THE 02.12Z ECMWF HAS TAKEN ABOUT A 4-6 HOUR STEP SLOWER THAN THE PREVIOUS RUN...SO SEVERE WEATHER FOR WESTERN WI IS STILL NOT RULED OUT. .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY 335 PM CDT THU AUG 2 2012 A DRIER PERIOD IS SEEN HERE AS THE LARGE SCALE TROUGH DEEPENS OVER HUDSONS BAY AND IMPACTS THE WESTERN GREAT LAKES WITH LOWER HEIGHTS AND NORTHWEST FLOW. 02.12Z ECMWF IS MORE AGGRESSIVE WITH THE TROUGH DEPTH OVER THE AREA SUGGESTING A BIT COOLER THAN THE 02.12Z GFS. THE 02.12Z GEM WOULD AGREE MORE ON THE GFS SIDE...HOWEVER IT MAY BE OFF IN ITS TIMING AS IT HAS A DEEPER SHORTWAVE TROUGH ROTATING SOUTHWARD ABOUT 24 HOURS AFTER THE 02.12Z ECMWF SOLUTION. IN EITHER CASE...THE SENSIBLE WEATHER IS MAINLY A COOLER FORECAST IN THE ECMWF. THUS...HAVE TAKEN A FEW DEGREES OFF A CONSENSUS FORECAST. THE 02.00Z GFS ENSEMBLE DATA DID SHOW HIGHER SIGNS OF SPREAD IN THE MID-WEEK HIGHS WITH A 78-87F RANGE...AND THE OPERATIONAL GFS MOS WAS ON THE WARM SIDE. STILL THINK THE 02.12Z GFS IS ON THE WARM SIDE AND HAVE UNDERCUT THOSE VALUES. FORECAST TEMPERATURES WILL BE PLEASANT AND NEAR NORMAL. PRECIPITATION CHANCES ARE SMALL THROUGH THE WEEK AND HARD TO TIME OUT AT THIS POINT. && .AVIATION...THROUGH 18Z FRIDAY 1232 PM CDT THU AUG 2 2012 COLD FRONT WILL PUSH THROUGH THE TAF SITES BY 18Z...WITH A LIGHT NORTHWEST WIND IN ITS WAKE. EXTENSIVE LAYER OF MID LEVEL CLOUDS WILL AFFECT BOTH SITES THROUGH MUCH OF THE AFTERNOON...WITH SCATTERED TO BROKEN CONDITIONS. CLOUDS WILL CLEAR OUT THIS EVENING AND REMAIN CLEAR THROUGH 18Z FRIDAY. WITH THE OVERNIGHT RAIN...THERE IS SOME CONCERN FOR FOG TONIGHT. THE BIGGEST NEGATIVE FOR FOG FORMATION WILL BE WINDS. THE 02.12Z NAM SUGGEST WINDS WILL REMAIN IN THE 10 TO 15 KNOT RANGE LATE TONIGHT JUST ABOVE THE SURFACE. WILL HAVE TO MONITOR THIS CLOSE THROUGH THE EVENING HOURS AND IF THE WINDS LOOK TO BE LIGHTER WILL HAVE TO ADD MORE FOG TO THE TAFS. FOR THE 18Z TAFS WILL CONTINUE TO MENTION 5SM BR BETWEEN 07Z-14Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 335 PM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1232 PM CDT THU AUG 2 2012 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT 359 AM CDT THU AUG 2 2012 AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE 02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A 700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE. AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE NMM AND ARW ALSO SUPPORT THIS TOO. FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA. THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL PASSAGE. .LONG TERM...SUNDAY THROUGH THURSDAY 359 AM CDT THU AUG 2 2012 ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE FORECAST AREA. FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES. BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT WERE PRODUCED IN THE ALL BLEND. && .AVIATION...THROUGH 18Z FRIDAY 1232 PM CDT THU AUG 2 2012 COLD FRONT WILL PUSH THROUGH THE TAF SITES BY 18Z...WITH A LIGHT NORTHWEST WIND IN ITS WAKE. EXTENSIVE LAYER OF MID LEVEL CLOUDS WILL AFFECT BOTH SITES THROUGH MUCH OF THE AFTERNOON...WITH SCATTERED TO BROKEN CONDITIONS. CLOUDS WILL CLEAR OUT THIS EVENING AND REMAIN CLEAR THROUGH 18Z FRIDAY. WITH THE OVERNIGHT RAIN...THERE IS SOME CONCERN FOR FOG TONIGHT. THE BIGGEST NEGATIVE FOR FOG FORMATION WILL BE WINDS. THE 02.12Z NAM SUGGEST WINDS WILL REMAIN IN THE 10 TO 15 KNOT RANGE LATE TONIGHT JUST ABOVE THE SURFACE. WILL HAVE TO MONITOR THIS CLOSE THROUGH THE EVENING HOURS AND IF THE WINDS LOOK TO BE LIGHTER WILL HAVE TO ADD MORE FOG TO THE TAFS. FOR THE 18Z TAFS WILL CONTINUE TO MENTION 5SM BR BETWEEN 07Z-14Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 359 AM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...RABERDING