Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/20/14


AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
1004 PM PDT TUE JUN 17 2014 .UPDATE... FRONTAL BOUNDARY CONTINUES TO PUSH THROUGH WESTERN NEVADA THIS EVENING. IT KICKED UP QUITE A BIT OF DUST IN CHURCHILL AND MINERAL COUNTY THIS EVENING WITH VISIBILITY DROPPING TO AS LOW AS ONE MILE AT TIMES AROUND HIGHWAY 95 ALONG WALKER LAKE AND AROUND THE HAWTHORNE AREA. GUSTY WINDS WILL CONTINUE THROUGH MIDNIGHT, ALONG WITH THE AREAS OF BLOWING DUST IN MINERAL COUNTY. HOON && .PREVIOUS DISCUSSION... /ISSUED 433 PM PDT TUE JUN 17 2014/ UPDATE... QUICK UPDATE THIS AFTERNOON TO EXTEND THE SHOWERS AND THUNDERSTORM CHANCES SOUTH OF RENO INTO CARSON CITY AND LAKE TAHOE AS THE SHORTWAVE PUSHES INTO NORTHERN NEVADA. THERE IS CONVECTIVE DEVELOPMENT OVER THE CARSON RANGE WEST OF RENO-CARSON AND COULD POTENTIALLY PRODUCE LIGHT RAIN, GUSTY WINDS AND POSSIBLY OCCASIONAL LIGHTNING. SHOWERS NORTH OF INTERSTATE 80 CONTINUE TO PUSH SOUTHWARD INTO THE PYRAMID LAKE AND LOVELOCK AREAS THIS AFTERNOON, BUT HAVE SO FAR REMAINED JUST SHOWERS WITH NO LIGHTNING STRIKES DETECTED. GUSTY OUTFLOW WINDS FROM THESE SHOWERS ARE ALSO POSSIBLE AND COULD CREATE SOME LOCALIZED BLOWING DUST NEAR DRY LAKE BEDS. PREVIOUS DISCUSSION... /ISSUED 224 PM PDT TUE JUN 17 2014/ SYNOPSIS... A COLD LOW PRESSURE SYSTEM WILL EXIT THE REGION AND RESULT IN DRIER CONDITIONS AND MUCH WARMER TEMPERATURES BEGINNING WEDNESDAY AFTERNOON AND PERSISTING THROUGH THE WEEKEND. A FEW COLDER SIERRA VALLEYS WILL DROP NEAR OR SLIGHTLY BELOW FREEZING TONIGHT WITH A FEW 30S IN OUTLYING COLDER VALLEYS IN WESTERN NEVADA. SHORT TERM... SHORTWAVE THAT BROUGHT SHOWERS AND MEASURABLE RAINFALL TO PARTS OF NORTHEAST CA AND NORTHWEST NV HAS EXITED WITH SUBSIDENCE AND DRIER AIR ALOFT HELPING TO ERODE CUMULUS FIELD ALONG THE EASTERN SIERRA AND WESTERN NV. SATELLITE IMAGERY SHOWS ANOTHER SHORTWAVE DROPPING SOUTHEASTWARD TOWARD THE AREA WHICH WILL TRACK MAINLY ACROSS NORTHWEST INTO CENTRAL NV ON BACK SIDE OF UPPER LOW WHERE INSTABILITY WILL BE MORE FAVORABLE THROUGH EARLY THIS EVENING FOR A FEW SHOWERS. THE NAM CONTINUES TO HOLD A NARROW BAND OF SHOWERS TOGETHER ON THE FAR WESTERN EDGE AS IT APPROACHES RENO 00Z-03Z. OTHER MODELS INCLUDING THE HRRR DO NOT SHOW THIS EXTENSION. CONFIDENCE IS LOW BUT WILL INCLUDE IT FOR AREAS JUST NORTH OF RENO INCLUDING PYRAMID LAKE. BEST FORCING/CONVERGENCE IS ACROSS NORTH CENTRAL-NORTHEAST NV WITH A THUNDERSTORM OR TWO POSSIBLE ACROSS THE BASIN AND RANGE. TEMPERATURES WILL BE QUITE COLD TONIGHT AS SKIES CLEAR AND WINDS DECREASE. THE AIRMASS IS NOT PARTICULARLY DRY AND THUS TEMPERATURES MAY NOT GET AS LOW AS SOME OF THE COLDEST MOS GUIDANCE. HOWEVER, COLDER SIERRA VALLEYS WILL LIKELY SEE A LIGHT FREEZE WITH EVEN SOME OF THE OUTLYING COLDER WESTERN NV VALLEYS DROPPING INTO THE 30S BY WEDNESDAY MORNING. IF YOUR LOW IS FORECAST TO DROP BELOW 40 DEGREES, YOU MAY WANT TO CONSIDER TAKING SOME GENERAL PRECAUTIONS TO PROTECT SENSITIVE PLANTS. HEIGHTS BEGIN TO RISE WEDNESDAY AFTERNOON INTO THURSDAY FOR A FAST WARMUP. TEMPERATURES IN COLDER SIERRA VALLEYS WILL NOT BE AS COLD THURSDAY MORNING ALTHOUGH THEY COULD STILL GET DOWN TO NEAR OR JUST ABOVE FREEZING FOR ONE MORE NIGHT. DAYTIME HIGHS WILL REMAIN JUST SHY OF NORMAL FOR WEDNESDAY BUT REBOUND TO ABOVE NORMAL FOR THURSDAY WITH 70S SIERRA VALLEYS AND 80S WESTERN NV. HOHMANN LONG TERM...FRIDAY THROUGH TUESDAY... THE LONG TERM FORECAST REMAINS UNCHANGED. THE REGION WILL REMAIN ANCHORED BETWEEN A NORTHEAST PACIFIC TROUGH AND ROCKIES/NORTHERN PLAINS RIDGE THROUGH THE LONG TERM FORECAST, WITH A FEW MINOR DISTURBANCES PERIODICALLY MOVING OVERHEAD. THE GFS REMAINS THE STRONGEST WITH THE FRIDAY DISTURBANCE ALTHOUGH EVEN IT IS SHIFTING NORTH WITH THE BEST LOW-MID LEVEL INSTABILITY AND FORCING OVER EXTREME NORTHEAST CALIFORNIA, NORTHWESTERN NEVADA AND OREGON. MEANWHILE, THE ECMWF/GEM LOOK VERY WEAK AND FLAT WITH FRIDAY`S DISTURBANCE WITH LITTLE INDICATION OF THUNDERSTORMS. THE OTHER THING OF SOME CONCERN FRIDAY WILL BE WINDS FOR NORTHEAST CALIFORNIA AND GENERALLY NORTH OF HIGHWAY 50 INTO FAR WESTERN NEVADA (SIERRA FRONT). GRADIENTS INCREASE WITH THE MOS HIGH TEMPERATURE BETWEEN THE SIERRA (TRUCKEE) AND WEST-CENTRAL NEVADA (LOVELOCK) IMPLYING INCREASED WINDS WITH GUSTS TO AROUND 30 MPH POSSIBLE FOR THE SIERRA FRONT. SATURDAY THROUGH TUESDAY, EASTERN CALIFORNIA AND WESTERN NEVADA WILL REMAIN IN FLAT SOUTHWEST-WEST FLOW ALOFT. THIS WILL BRING THE TYPICAL DAILY ZEPHYR BREEZES FOR THE EASTERN SIERRA AND OUT INTO WESTERN NEVADA. DEPENDING ON THE SMALL-SCALE, LOW CONFIDENCE DETAILS OF ANY WEAK UPPER DISTURBANCES MOVING OVERHEAD THE ZEPHYR MAY BE PERIODICALLY ENHANCED WITH AN INCREASED FIRE CONCERN. SNYDER AVIATION... AN UPPER DISTURBANCE, CURRENTLY LOCATED NEAR KAAT, IS MOVING AROUND THE LARGE UPPER TROUGH CENTERED OVER THE NORTHERN ROCKIES. THE DISTURBANCE IS EXPECTED TO KICK OFF A FEW LIGHT SHOWERS NORTH AND EAST OF KRNO, WITH A FEW THUNDERSTORMS POSSIBLE EAST AND NORTH OF A GERLACH TO PYRAMID LAKE TO KNFL LINE THROUGH SUNSET. BRIEF HIGHER TERRAIN OBSCURATION, SMALL HAIL (LESS THAN HALF-INCH) AND WIND GUSTS TO AROUND 30 KTS COULD ACCOMPANY ANY THUNDERSTORMS. LATE TONIGHT, THE MARTIS VALLEY NEAR KTRK COULD SEE PATCHY FOG. OTHERWISE, VFR CONDITIONS WITH MAINLY LIGHT WINDS (LESS THAN 8 KTS) WILL RETURN OVERNIGHT AND FOR WEDNESDAY AS HIGH PRESSURE BUILDS INTO CALIFORNIA. SNYDER && .REV WATCHES/WARNINGS/ADVISORIES... NV...NONE. CA...NONE. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1149 AM MDT WED JUN 18 2014 .UPDATE... ISSUED AT 1141 AM MDT WED JUN 18 2014 THE FRONTAL PASSAGE WHICH STALLED OVERNIGHT OVER NORTHWESTERN COLORADO FINALLY HAS GAINED FORWARD MOMENTUM AND IS TREKKING EAST. BANDS OF SHOWERS ARE POPPING UP ALONG THIS BOUNDARY AND WILL MOVE THROUGH SOUTHEASTERN UTAH AND WESTERN COLORADO THROUGH THE AFTERNOON. EXPECTING BEST CHANCE OF SHOWERS AND THUNDERSTORMS TO STILL BE OVER THE DIVIDE MOUNTAINS WHERE INSTABILITY AND MOISTURE IS BEST. THE WINTER WEATHER ADVISORY FOR THE EASTERN UINTA MOUNTAIN WAS CANCELLED AS SNOW HAS MOVED EAST OUT OF THE AREA. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 324 AM MDT WED JUN 18 2014 DEEP UPPER LEVEL LOW OVER NORTHEAST IDAHO WILL LIFT NORTHEAST ACROSS MONTANA TODAY. THIS WILL HELP SWING SHRTWV ENERGY THROUGH THE FORECAST AREA LATER THIS MORNING AND THIS AFTERNOON. LIMITED MOISTURE FIELD WILL STILL BE ENOUGH TO SPARK SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON...MAINLY ACROSS WESTERN COLORADO AS CONDITIONS DESTABILIZE WITH COOLING ALOFT. IN THE MEANTIME...SNOW SHOWERS ACROSS THE EASTERN UINTA MOUNTAINS AND HIGHER PEAKS IN EXTREME NORTHWEST COLORADO WILL CONTINUE THROUGH THIS MORNING...BEFORE TAPERING OFF AROUND 18Z PER LATEST HRRR GUIDANCE. WILL KEEP CURRENT WINTER WEATHER ADVISORY HIGHLIGHTS IN PLACE...WITH NO EXPANSION ANTICIPATED AS DEEPER POOL OF COLD AIR SHIFTS NORTHEAST INTO WYOMING...LEAVING THE NORTHERN MOUNTAINS IN WESTERN COLORADO WITH SNOW LEVELS OVER 12K. ELEVATED FIRE CONCERNS REMAIN IN PLAY ACROSS THE SOUTHWEST VALLEYS FROM CORTEZ EAST TO PAGOSA SPRINGS...AS THE COLD FRONT STALLS NEAR THE SAN JUANS. SO WILL KEEP RED FLAG WARNINGS IN PLACE. GUSTY WINDS SHOULD DIMINISH BY SUNSET...AND A FEW DAYTIME SHOWERS MAY LINGER INTO THE EVENING. A FINAL PV LOBE SWINGS ACROSS THE NORTH TOWARD MIDNIGHT BUT WITH INCREASING STABILITY AND SHRINKING MOISTURE...ONLY SOME CLOUDS ARE EXPECTED OVERNIGHT. WITH ENOUGH CLEARING...RADIATIONAL COOLING COULD ALLOW TEMPS TO DIP TO AROUND FREEZING IN THE CRAIG/MEEKER AREAS TONIGHT...WHERE A FREEZE WATCH REMAINS IN EFFECT. WEAKLY CYCLONIC FLOW CONTINUES ON THU WITH THE UPPER LOW OVER THE SASKATCHEWAN/MONTANA BORDER. AIR REMAINS DRY FOR LITTLE OTHER THAN SOME HIGH CLOUDS ACROSS THE NORTH. TEMPERATURES BEGIN TO MODERATE THU. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 324 AM MDT WED JUN 18 2014 DRY AIR REMAINS THE MAJOR PLAYER FOR ERN UT/WRN CO THU NIGHT AND FRI. GFS/ECMWF SHOW SOME 500-300 MB PAC MOISTURE REACHING OUR AREA IN THE FORM OF HIGH CLOUDS FRI AFTERNOON IN WESTERLY FLOW. TEMPS CONTINUE TO REBOUND FROM THE MIDWEEK COOLDOWN. FAIRLY QUIET PERIOD CONTINUES THROUGH TUESDAY WITH TEMPERATURES CLIMBING TO THE PLUS SIDE OF NORMAL AS WE MOVE THROUGH THE WEEKEND. CONDITIONS LOOK DRY UNDER A RIDGE OF HIGH PRESSURE...BUT CANNOT RULE OUT AN ISOLATED STORM OVER THE HIGH COUNTRY MONDAY AND TUESDAY AS A SMIDGEN OF MOISTURE WORKS IN UNDER THE RIDGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1141 AM MDT WED JUN 18 2014 GUSTY CONDITIONS WILL OCCUR WITH THE PASSING OF A SECONDARY COLD FRONT WHICH IS NOW MOVING EASTWARD ACROSS WESTERN COLORADO AND VERY SOUTHEASTERN UTAH. WINDS AT VALLEY SITES ARE NOT EXPECTED TO GUST HIGHER THAN 20-25 MPH...BUT WILL LIKELY BE HIGHER AT MOUNTAIN TAF SITES NEAR VIRGA AND THUNDERSTORMS. EXPECT A MAJOR DOWNTURN IN SHOWER ACTIVITY IN EASTERN UTAH AFTER 21Z THIS AFTERNOON AND AFTER 00Z IN WESTERN COLORADO THIS EVENING. && .FIRE WEATHER... ISSUED AT 324 AM MDT WED JUN 18 2014 A RED FLAG WARNING REMAINS IN EFFECT FOR FIRE WEATHER ZONE 207 BELOW 9500 FEET BETWEEN NOON AND 700 PM MDT TODAY FOR CONTINUED GUSTY WEST TO SOUTHWEST WINDS AND LOW HUMIDITY. THE COLD FRONT WILL CLEAR THE AREA THIS EVENING...AND WINDS ARE EXPECTED TO DECREASE BEHIND THIS FRONTAL PASSAGE. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR COZ207. FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR COZ002. UT...NONE. && $$ UPDATE...JAM SHORT TERM...JDC/JAD LONG TERM...JAD/JDC AVIATION...JAM FIRE WEATHER...JDC
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
325 AM MDT WED JUN 18 2014 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 324 AM MDT WED JUN 18 2014 DEEP UPPER LEVEL LOW OVER NORTHEAST IDAHO WILL LIFT NORTHEAST ACROSS MONTANA TODAY. THIS WILL HELP SWING SHRTWV ENERGY THROUGH THE FORECAST AREA LATER THIS MORNING AND THIS AFTERNOON. LIMITED MOISTURE FIELD WILL STILL BE ENOUGH TO SPARK SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON...MAINLY ACROSS WESTERN COLORADO AS CONDITIONS DESTABILIZE WITH COOLING ALOFT. IN THE MEANTIME...SNOW SHOWERS ACROSS THE EASTERN UINTA MOUNTAINS AND HIGHER PEAKS IN EXTREME NORTHWEST COLORADO WILL CONTINUE THROUGH THIS MORNING...BEFORE TAPERING OFF AROUND 18Z PER LATEST HRRR GUIDANCE. WILL KEEP CURRENT WINTER WEATHER ADVISORY HIGHLIGHTS IN PLACE...WITH NO EXPANSION ANTICIPATED AS DEEPER POOL OF COLD AIR SHIFTS NORTHEAST INTO WYOMING...LEAVING THE NORTHERN MOUNTAINS IN WESTERN COLORADO WITH SNOW LEVELS OVER 12K. ELEVATED FIRE CONCERNS REMAIN IN PLAY ACROSS THE SOUTHWEST VALLEYS FROM CORTEZ EAST TO PAGOSA SPRINGS...AS THE COLD FRONT STALLS NEAR THE SAN JUANS. SO WILL KEEP RED FLAG WARNINGS IN PLACE. GUSTY WINDS SHOULD DIMINISH BY SUNSET...AND A FEW DAYTIME SHOWERS MAY LINGER INTO THE EVENING. A FINAL PV LOBE SWINGS ACROSS THE NORTH TOWARD MIDNIGHT BUT WITH INCREASING STABILITY AND SHRINKING MOISTURE...ONLY SOME CLOUDS ARE EXPECTED OVERNIGHT. WITH ENOUGH CLEARING...RADIATIONAL COOLING COULD ALLOW TEMPS TO DIP TO AROUND FREEZING IN THE CRAIG/MEEKER AREAS TONIGHT...WHERE A FREEZE WATCH REMAINS IN EFFECT. WEAKLY CYCLONIC FLOW CONTINUES ON THU WITH THE UPPER LOW OVER THE SASKATCHEWAN/MONTANA BORDER. AIR REMAINS DRY FOR LITTLE OTHER THAN SOME HIGH CLOUDS ACROSS THE NORTH. TEMPERATURES BEGIN TO MODERATE THU. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 324 AM MDT WED JUN 18 2014 DRY AIR REMAINS THE MAJOR PLAYER FOR ERN UT/WRN CO THU NIGHT AND FRI. GFS/ECMWF SHOW SOME 500-300 MB PAC MOISTURE REACHING OUR AREA IN THE FORM OF HIGH CLOUDS FRI AFTERNOON IN WESTERLY FLOW. TEMPS CONTINUE TO REBOUND FROM THE MIDWEEK COOLDOWN. FAIRLY QUIET PERIOD CONTINUES THROUGH TUESDAY WITH TEMPERATURES CLIMBING TO THE PLUS SIDE OF NORMAL AS WE MOVE THROUGH THE WEEKEND. CONDITIONS LOOK DRY UNDER A RIDGE OF HIGH PRESSURE...BUT CANNOT RULE OUT AN ISOLATED STORM OVER THE HIGH COUNTRY MONDAY AND TUESDAY AS A SMIDGEN OF MOISTURE WORKS IN UNDER THE RIDGE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 324 AM MDT WED JUN 18 2014 BREEZY TO WINDY CONDITIONS WILL REMAIN IN PLACE ACROSS EASTERN UTAH AND WESTERN COLORADO AS A COLD FRONT CONTINUES TO MARCH EAST AND SOUTH. THE FRONT IS EXPECTED TO STALL NEAR THE SAN JUAN MOUNTAINS THIS MORNING BEFORE MAKING A FINAL PUSH ACROSS THE REGION AFTER 20Z THIS AFTERNOON. UPPER LEVEL ENERGY BRINGS SCATTERED SHOWERS AND THUNDERSTORMS TO NORTHEAST UTAH AND WESTERN COLORADO. SHOWERS END AFTER 03Z WITH CLEARING SKIES AND LIGHT WINDS EXPECTED FOR THE REMAINDER OF THE NIGHT. VFR CONDS EXPECTED TO HOLD AT ALL TERMINAL SITES THROUGH THE PERIOD. && .FIRE WEATHER... ISSUED AT 324 AM MDT WED JUN 18 2014 A RED FLAG WARNING REMAINS IN EFFECT FOR FIRE WEATHER ZONE 207 BELOW 9500 FEET BETWEEN NOON AND 700 PM MDT TODAY FOR CONTINUED GUSTY WEST TO SOUTHWEST WINDS AND LOW HUMIDITY. THE COLD FRONT WILL CLEAR THE AREA THIS EVENING...AND WINDS ARE EXPECTED TO DECREASE BEHIND THIS FRONTAL PASSAGE. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING FROM NOON TODAY TO 7 PM MDT THIS EVENING FOR COZ207. FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR COZ002. UT...WINTER WEATHER ADVISORY UNTIL NOON MDT TODAY FOR UTZ023. && $$ SHORT TERM...JDC/JAD LONG TERM...JAD/JDC AVIATION...JDC FIRE WEATHER...JDC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
255 AM MDT WED JUN 18 2014 .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 255 AM MDT WED JUN 18 2014 AN UPPER LEVEL STORM SYSTEM WILL MOVE SLOWLY ACROSS THE NRN ROCKIES AS A DISTURBANCE MOVES EASTWARD ACROSS NRN CO THIS AFTN INTO THE EARLY EVENING HOURS. MEANWHILE AT THE SFC A COOL FNT WAS ALREADY MOVING ACROSS NERN CO EARLY THIS MORNING. THIS FNT WILL EVENTUALLY STALL OUT OVER THE PALMER DIVIDE AND THEN BEGIN TO LIFT NORTH AS A WRM FNT THIS AFTN AS SFC LOW PRES DEVELOPS NEAR DENVER. OVERALL SHOULD SEE SCT HIGH BASED SHOWERS AND STORMS DEVELOP OVER THE MTNS BY MIDDAY AND THEN SPREAD QUICKLY EASTWARD ACROSS THE PLAINS FM LATE AFTN THRU THE EARLY EVENING HOURS WITH THE BEST COVERAGE FM DENVER TO AKRON NORTHWARD. SOME DEEPER LOW LVL MOISTURE MAY MOVE INTO THE FAR NERN CORNER BY EARLY EVENING WHICH MAY LEAD TO A CHC OF A FEW SVR STORMS OVER THE FAR NERN PLAINS. CLOSER TO THE FRONT RANGE THE AIRMASS WILL BE DRIER HOWEVER WITH INCREASING MID LVL FLOW THE STORMS WILL PRODUCE GUSTY OUTFLOW WINDS. AS FOR HIGHS TODAY WILL KEEP READINGS IN THE LOWER TO MID 80S ACROSS NERN CO HOWEVER SOUTH OF THE WRM FNT READINGS COULD GET CLOSE TO 90 AS LOW LVL WINDS BECOME SWLY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 255 AM MDT WED JUN 18 2014 MODELS SHOW AN UPPER TROUGH AXIS PUSHING EASTWARD ACROSS THE CWA THURSDAY. THURSDAY NIGHT THROUGH FRIDAY SHOWS ZONAL FLOW ALOFT FOR THE FORECAST AREA. DOWNWARD SYNOPTIC SCALE ENERGY IS PROGGED OVER THE CWA THURSDAY AND THURSDAY EVENING...THEN BENIGN ENERGY IS PROGGED INTO THE WEEKEND. LOW LEVEL WIND AND PRESSURE FIELDS HAVE EAST TO SOUTHEASTERLY BOUNDARY LAYER FLOW FOR THE CWA THURSDAY AND THURSDAY EVENING. ON FRIDAY AND FRIDAY EVENING...EAST- NORTHEASTERLY WINDS ARE INDICATED. CONCERNING MOISTURE...THERE IS LITTLE THURSDAY..BUT A BIT OVER THE EASTERN HALF BY AFTERNOON INTO THE EVENING. THE REST OF THE THURSDAY NIGHT AND FRIDAY ARE FAIRLY DRY TOO. THERE IS SOME UPPER LEVEL MOISTURE FRIDAY NIGHT. BOUNDARY LAYER DEW POINTS OVER THE PLAINS ARE IN THE 40S TO MID 50S F OVER THE PLAINS THROUGH THE PERIODS. THERE IS MINOR CAPE OVER THE FAR EAST LATE DAY THURSDAY...WITH HIGHER VALUES OVER MORE OF THE PLAINS FOR LATE DAY FRIDAY. VALUES OVER THE EASTERN BORDER ARE ABOUT 2000 J/KG AT 00Z FRIDAY AFTERNOON. THE QPF FIELDS HAVE A TAD OF MEASURABLE PRECIPITATION OVER THE PLAINS...MAINLY DURING THE LATE IN THE DAY PERIODS. WILL LEAVE POPS OUT FOR NOW THROUGH FRIDAY NIGHT. FOR TEMPERATURES...THURSDAY`S HIGHS ARE CLOSE TO TODAY`S. FRIDAY`S WARM UP ABOUT 2 C. FOR THE LATER DAYS...SATURDAY THROUGH TUESDAY...MODELS KEEP WEAK WEST TO SOUTHWESTERLY FLOW ALOFT FOR THE CWA WITH WEAK UPPER RIDGING AROUND. THERE IS SOME MOISTURE AROUND...ESPECIALLY SUNDAY THROUGH TUESDAY. THE AIRMASS IS COOLER MONDAY AND TUESDAY. && .AVIATION...(FOR THE TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 255 AM MDT WED JUN 18 2014 WK FNT HAS MOVED INTO THE AREA EARLY THIS MORNING AND IS FCST TO STAY NRLY STATIONARY OR SLOWLY LIFT BACK TO THE NORTH BY EARLY AFTN. THE RAP AND HRRR DVLP A SFC LOW ALONG THIS BNDRY NR DENVER AND KEEP WINDS AT DIA BASCIALLY ESE THRU THE EARLY AFTN. BY 21Z THR RAP MOVES THE SFC LOW NORTH OF DENVER WITH WINDS BECOMING MORE WLY AND THEN NWLY BY 00Z. MEANWHILE THERE WILL BE SOME WDLY SCT HIGHER BASED STORMS BY 21Z WHICH MAY LINGER THRU 00Z BEFORE MOVING EAST OF THE AREA BY EARLY EVENING. WITH INCREASING MID LVL FLOW GUSTY OUTFLOW WINDS UP TO 50 MPH COULD OCCUR WITH THE CONVECTION. BY EARLY EVENING A COLD FNT WILL MOVE ACROSS THE AREA WITH WINDS BECOMING NNE FOR A FEW HOURS. BY 06Z WINDS SHOULD TREND TOWARD DRAINAGE AND CONTINUE THROUGH 12Z THU. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RPK LONG TERM...RJK AVIATION...RPK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1145 PM MDT TUE JUN 17 2014 .UPDATE... ISSUED AT 1117 PM MDT TUE JUN 17 2014 LOADED LATEST SURFACE OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. NO OTHER CHANGES TO FORECAST AT THIS TIME. LW UPDATE ISSUED AT 855 PM MDT TUE JUN 17 2014 RED FLAG WARNING ALLOWED TO EXPIRE FOR TONIGHT. CONDITIONS HAVE SUBSIDED BELOW CRITICAL FIRE WEATHER LEVELS. ALSO...LOADED IN LATEST OBSERVATIONS. LW UPDATE ISSUED AT 651 PM MDT TUE JUN 17 2014 LOADED IN LATEST OBSERVATIONS. NO OTHER CHANGES TO FORECAST AT THIS TIME. LW && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 247 PM MDT TUE JUN 17 2014 .SHORT TERM...(TONIGHT AND TOMORROW) CURRENTLY...THE UPPER LOW WAS LOCATED OVER IDAHO THIS AFTN...PRODUCING STRONG SW FLOW ALOFT ACROSS THE 4 CORNERS AND COLORADO. THERE IS SLIGHTLY MORE MOISTURE AVAILABLE AS EVIDENCED BY A BIT MORE CU OVER THE MTS...BUT FOR THE MOST PART TODAY WAS VERY SIMILAR TO YESTERDAY WITH STRONG W-SW WINDS WITH GUSTS OF 35-45 MPH...SINGLE DIGIT RH READINGS AND MAX TEMPS IN THE UPPER 80S TO MID 90S FOR THE PLAINS...AND AROUND 80 F FOR THE HIGH VALLEYS. TONIGHT AND TOMORROW...THE UPPER SYSTEM IS FORECAST TO TRACK EAST ACROSS THE NORTHERN ROCKIES OVER THE NEXT 24 HRS...WITH A TIGHTENING OF THE PRES GRADIENT AND MOISTURE EDIFICATION EXPECTED LATE TONIGHT THROUGH WED. MODELS HAD INITIALLY HINTED AT SOME ISOLATED CONVECTION OVER THE SOUTHERN MES THIS EVE...BUT LATEST RADAR AND SATELLITE TRENDS AS WELL AS THE LATEST HRRR RUN POINTS TO A DRY NIGHT. THEREFORE...PULLED POPS TONIGHT. ONGOING FORKS HIGHLIGHTS FOR TONIGHT LOOK GOOD...AND WILL SHUT DOWN AT 9 PM. AS FOR TOMORROW...DECIDED TO UPGRADE THE WATCH TO A RED FLAG WARNING FOR EL PASO AND FREMONT COUNTIES SINCE THOSE ARE THE ONLY AREAS THAT REPORT RECEPTIVE FUELS. ANOTHER WINDY...HOT AND DRY DAY IS EXPECTED...BUT ISOLATED CONVECTION IS FORECAST TO START DEVELOPING OVER THE HIGHER TERRAIN BY LATE MORNING...AND OVER THE FAR EASTERN PLAINS TOMORROW AFN. ONE OR TWO OF THE STORMS OVER THE FAR SE CORNER WILL HAVE FAVORABLE SHEAR AND ENOUGH LLVL MOISTURE ON TAP TO BECOME STRONG. LOOK FOR MAX TEMPS ONCE AGAIN TO BE IN THE 90S FOR THE E PLAINS...AND MID TO UPPER 70S FOR THE HIGH VALLEYS. MOOR .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 247 PM MDT TUE JUN 17 2014 ...WETTER CONDITIONS POSSIBLE LATE WEEKEND INTO EARLY NEXT WEEK... ...ISOLD SVR THREAT POSSIBLE EARLY TOMORROW EVENING OVER FAR SE CO... STRONG SOUTHWEST FLOW ALOFT AT THE BEGINNING OF THIS PERIOD WILL GRADUALLY TRANSITION TO LIGHT WESTERLY FLOW AND THEN A VERY WEAK FLOW PATTERN BY EARLY NEXT WEEK. THIS PATTERN WILL SHOULD ALLOW FOR A WETTER PATTERN FOR THE REGION...ESPECIALLY LATE WEEKEND INTO EARLY NEXT WEEK. WED NITE... THERE IS A SLIGHT CHANCE THAT WE MAY SEE A STRONG STORM OVER THE FAR SE PLAINS ON THIS DAY AS THE DRYLINE WILL BE OVER THE REGION. MAIN CONCERN WILL BE STRONG GUSTY WINDS AND LIGHTNING WHICH WILL HAVE THE POTENTIAL TO CAUSE A GRASS FIRE DUE TO THE GUSTY SYNOPTIC S-SW WINDS. HOWEVER...I SHOULD NOTE...THAT THE LATEST 18Z NAM HINTS AT THE DRYLINE RETROGRADING BACK WEST OVER FAR SE CO. SFC WINDS SHIFT TO SOUTHEAST AND EHI AND STP RAPIDLY INCREASE ALONG THE CO/KS BORDER. THIS AREA WILL HAVE TO BE WATCHED CAREFULLY. LATE WED EVENING...A COOL FRONT WILL COME DOWN THE PLAINS. BEST CHANCE OF ANY POPS WITH THIS BOUNDARY WILL BE OVER THE E PLAINS...WHILE THE REST OF THE REGION SHOULD REMAIN DRY. THURSDAY... COOLER UPSLOPE FLOW WILL BE OVER THE REGION. HOWEVER...LLVL ATMOS WILL BE ON THE DRY SIDE SO NOT EXPECTING MUCH IN THE WAY OF ANY SIGNIFICANT CONVECTION. ANY CONVECTION THAT DEVELOPS WILL LIKELY BE LATE IN THE DAY OVER THE RATON MESA REGION AND MAYBE THE E SLOPES OF THE S MTNS. MAX TEMPS THU SHOULD BE ABOUT 4-8F COOLER ON THE PLAINS AS COMPARED TO WED MAXES. FRIDAY... WEAK DISTURBANCES ALOFT WILL MOVE OVER THE REGION AS THE FLOW ALOFT CONTINUES TO WEAKEN. OVERALL EXPECT IT TO REMAIN DRY...WITH ONLY ISOLD POPS OVER THE S MTNS AND POSSIBLY FAR E PLAINS. TEMPS WILL WARM BACK UP INTO THE U80S/L90S PLAINS. SATURDAY... LLVL MOISTURE WILL GRADUALLY INCREASE OVER THE PLAINS ON THIS DAY. EC IS MORE ROBUST WITH THIS MOISTURE THAN GFS...AND BREAKS OUT CONVECTION ALL AREAS...ESPECIALLY PALMER DVD REGION. MAX TEMPS SHOULD BE ABOUT A DEGREE OR TWO WARMER THAN FRI OVER THE PLAINS. SUNDAY... MOISTURE CONTINUES TO INCREASE OVER THE PLAINS AS CANADIAN HIGH PRESSURE BUILD SWD AND SEVERAL UPPER LVL DISTURBANCES MOVER OVER THE REGION IN THE WEAK ZONAL FLOW. MOISTURE MAY WORK A BIT FARTHER WEST INTO THE MTNS...ESPECIALLY C /MTNS AREA. ALL GUIDANCE HAS SOME HEALTHY QPF CONVECTIVE BULLSEYES OVER THE PLAINS...ESPECIALLY OVER THE PALMER DVD REGION. LIKEWISE...EXPECT A BETTER CHANCE OF SHOWERS AND STORMS OVER THE PLAINS ON THIS DAY WITH A BIT COOLER AFTERNOON TEMPS. WITH THE INCREASING MSTR AND WEAKER FLOW ALOFT...THE FLASH FLOOD THREAT OVER THE BURN SCARS WILL BE INCREASING. MONDAY AND TUESDAY... NOT MUCH CHANGE IN THE PATTERN AS FLOW ALOFT WILL BE FROM THE NW AND GENERALLY WEAK. SEVERAL DISTURBANCES WILL MOVE THROUGH THIS FLOW AND AFTERNOON AND EVENING ROUNDS OF CONVECTION ARE LIKELY OVER THE MTNS ADJ TO THE PLAINS...WITH THE CONVECTION MOVING INTO THE FAR E PLAINS DURING THE EVENING HOURS. TEMPS WILL BE ON THE COOL SIDE WITH THE CLOUDS AND MSTR OVER THE REGION. PERIODS OF HEAVY RAIN WILL BE POSSIBLE AND THE FLASH FLOOD CONCERNS WILL CONTINUE INTO EARLY NEXT WEEK OVER THE SCARS. OVERALL...THE INTERIOR MTNS WILL LIKELY REMAIN ON THE DRY SIDE DURING THIS PERIOD...WITH GRADUALLY INCREASING MSTR LATER IN THE PERIOD. THIS WILL ALLOW FOR THE INTERIOR MTNS TO CONTINUE TO DRY OUT WITH TIME. /HODANISH && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1117 PM MDT TUE JUN 17 2014 DRY SOUTHWEST FLOW WILL RESULT IN GENERALLY VFR THROUGH ABOUT 18Z WEDNESDAY. THEN...AN UPPER LEVEL DISTURBANCE WILL TRACK FROM WEST TO EAST ACROSS THE FORECAST AREA 18Z-06Z...TRIGGERING ISOLATED SHOWERS AND THUNDERSTORMS. MOISTURE WILL PRIMARILY BE HIGH BASED SO MAIN STORM THREATS WILL BE LIGHTNING AND GUSTY WINDS. HOWEVER...A FEW STORMS ACROSS THE FAR SOUTHEAST COLORADO PLAINS COULD BE STRONG OR SEVERE DUE TO BETTER MOISTURE. THESE STORMS COULD PRODUCE LARGE HAIL...WIND GUSTS OVER 60 MPH...LIGHTNING AND HEAVY RAIN. FORECAST MODELS GENERALLY AGREE THAT KCOS...KPUB AND KALS WILL GENERALLY BE VFR NEXT 24 HOURS. HOWEVER...THE PAST COUPLE RUNS OF THE NAM12 SUGGEST A BETTER CHANCE OF STORMS AT THESE SITES THAN THE OTHER MODELS. CONSEQUENTLY...CURRENT TAFS MAY NEED TO BE AMMENDED PENDING 12Z SOUNDING DATA AND MORNING MODEL RUNS. OTHER CONCERN TOMORROW WILL BE THE RETURN OF GUSTY SOUTHWEST WINDS 15 TO 30 MPH ACROSS THE AREA AFTER 16Z...WITH LOCALLY STRONGER GUSTS POSSIBLE...ESPECIALLY NEAR ANY CONVECTIVE ACTIVITY. LW && .FIRE WEATHER... ISSUED AT 855 PM MDT TUE JUN 17 2014 RED FLAG WARNING ALLOWED TO EXPIRE FOR TONIGHT. CONDITIONS HAVE SUBSIDED BELOW CRITICAL FIRE WEATHER LEVELS. && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON TO 8 PM MDT WEDNESDAY FOR COZ222-226- 227. && $$ UPDATE...LW SHORT TERM...MOORE LONG TERM...HODANISH AVIATION...LW FIRE WEATHER...LW
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1114 PM MDT TUE JUN 17 2014 .UPDATE... ISSUED AT 712 PM MDT TUE JUN 17 2014 WITH THE FRONT HAVING MOVED INTO THE UINTA BASIN...UPDATED THE FORECAST FOR NORTHEAST UTAH. TEMPS IN EXTREME SW WYOMING HAS FALLEN INTO THE 30S WITH SNOW AT EVANSTON. REMOTE SENSORS IN DAGGETT COUNTY SHOWING TEMPS HAVE DROPPED INTO THE 30S. APPEARS TO BE A WET ROAD ON HWY 191 PER UDOT WEB CAM...BUT IF CURRENT TREND HOLDS...THEN SNOW IS ABOUT TO BEGIN AND UPDATED THE WSW TO REFLECT THIS. ELSEWHERE...THE RAP MODEL SHOWS THE BAROCLINIC ZONE WEAKENING AS THE FRONT MOVES ACROSS MOFFAT COUNTY IN NW COLORADO. THE SNOW OVER THE UINTA MOUNTAINS MAY NOT MAKE IT TO THE ELKHEADS OR PARK RANGE. CURRENT FORECAST TRENDS APPEAR ON TRACK AND NO OTHER UPDATES NEEDED. && .SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT) ISSUED AT 400 PM MDT TUE JUN 17 2014 STRONG SOUTHWEST WINDS OBSERVED ACROSS THE FORECAST AREA TODAY AHEAD OF COLD FRONT OVER NORTHEAST UTAH STRETCHING FROM EAST OF KRKS-KMLF AT 21Z. MAGNITUDE OF WINDS FROM 20 TO 30 MPH ACROSS MOST VALLEY LOCATIONS WITH GUSTS FROM 45 TO 50 MPH. SO FAR...NO CONVECTIVE ACTIVITY OUT AHEAD OF THE FRONT AS MOISTURE RELATIVELY LIMITED IN ADVANCE OF THE SYSTEM. NOCTURNAL COOLING WILL ALLOW WINDS TO DECOUPLE OVER THE VALLEYS LATER THIS EVENING BUT WILL CONTINUE TO BLOW PRETTY HARD UNTIL THEN SO WILL HOLD ONTO WIND ADVISORY THROUGH 9 PM. LATEST SHORT-RANGE MODELS INDICATED THE FRONT WILL PASS THROUGH KVEL AND INTO EXTREME NORTHWEST COLORADO BY 6 PM. EXPECT SHOWERS AND ISOLATED THUNDERSTORMS WILL BE CONFINED TO AREAS ALONG AND BEHIND THE FRONT SO CUT BACK POPS SOUTHEAST OF THE BOUNDARY THIS EVENING. SNOW LEVEL LOWERS RAPIDLY OVER THE EASTERN UINTAS BEHIND THE STRONG FRONT SO RAIN LOWER TO AROUND 8000 FEET STILL LOOKS REASONABLE. FRONT PROGGED TO CONTINUE SLOWLY SOUTHEAST THROUGH THE NIGHT REACHING ROUGHLY A KEGE TO KPGA LINE BY MORNING. AGAIN... PRECIPITATION CONFINED TO AREAS BEHIND THE FRONT WITH NORTHEAST UTAH AND THE NORTHWEST CORNER OF COLORADO FAVORED. LATEST NAM12 CONTINUED TO GENERATE DECENT ACCUMULATIONS OVER THE EASTERN UINTA MOUNTAINS FOR MID JUNE SO WILL CONTINUE WINTER WEATHER ADVISORY THROUGH MIDDAY WEDNESDAY. SHORTWAVE ROTATING THROUGH THE BASE OF THE TROUGH WILL DRIVE THE FRONT ACROSS THE REMAINDER OF THE FORECAST AREA WEDNESDAY AFTERNOON. PASSAGE OF THE WAVE CORRESPONDS WITH PEAK HEATING SO EXPECT GOOD SHOWER AND THUNDERSTORM COVERAGE OVER THE MOUNTAINS AND ADJACENT VALLEYS. COLDEST AIR STAYS NORTH SO SNOW LEVELS AT OR ABOVE 10K FEET AND LITTLE IMPACT ON HIGH PASSES EXPECTED. EMBEDDED THUNDERSTORMS COULD BRING DOWN STRONG WINDS ALOFT...BUT OTHERWISE LESS WINDY THAN TODAY. MUCH COOLER BEHIND THE FRONT WITH HIGHS DROPPING BY 10 TO 15 DEGREES FOR MOST AREAS. PRECIPITATION ENDS PRETTY ABRUPTLY WEDNESDAY EVENING AS SUBSIDENCE ...COOLING...AND DRYING WORK ACROSS THE AREA. CLEARING SKIES WILL LEAD TO SOME COLD OVERNIGHT LOWS. THUS FAR APPEARS ONLY PORTIONS OF NORTHWEST COLORADO UNDER THE THREAT OF LATE SEASON FREEZE WHICH COULD IMPACT SENSITIVE VEGETATION. THEREFORE...HOISTED A FREEZE WATCH FOR THE AREA FROM MIDNIGHT TO 9 AM THURSDAY MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 400 PM MDT TUE JUN 17 2014 A COOL THURSDAY MORNING WITH NEAR OR BELOW FREEZING TEMPERATURES IN SOME MOUNTAIN AREAS WILL EVOLVE INTO AN UNSEASONABLY COOL AFTERNOON... WITH HIGH TEMPERATURES IN THE VALLEYS STRUGGLING TO GET TO 80 DEGREES. HOWEVER...THROUGHOUT THE DAY WARMER AIR ALOFT WILL ADVECT INTO THE REGION AS THE UPPER LEVEL TROUGH EXITS AND RIDGING MOVES OVER EASTERN UTAH AND WESTERN COLORADO. HIGH PRESSURE WILL REMAIN OVERHEAD THROUGH EARLY NEXT WEEK ALLOWING TEMPERATURES TO REBOUND BACK TO AND ABOVE NORMAL. MOISTURE ALONG THE FRONT RANGE WILL REGRESS WEST TOWARD THE DIVIDE ON SUNDAY EVENING...BRINGING THE POSSIBILITY OF DIURNALLY DRIVEN MOUNTAIN CONVECTION ALONG THE CENTRAL MOUNTAINS SUNDAY THROUGH TUESDAY. ELSEWHERE WILL STAY DRY WITH LIGHT DIURNALLY DRIVEN WINDS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1111 PM MDT TUE JUN 17 2014 COLD FRONT WILL CONTINUE PUSHING ACROSS WESTERN COLORADO THROUGH EARLY WEDNESDAY MORNING...CROSSING THE DIVIDE BY 12Z. LOCAL SURFACE WIND OF G25-30KTS WILL CONTINUE THROGUH WEDNESDAY AFTERNOON. TURBULENCE WILL BE LESS...BUT STILL EXPECT SOME MODERATE CHOP. NE UTAH AND WRN COLORADO...SCT -SHRA/ISOLD -TSRA OVER NE UTAH WITH SNOW LEVEL LOWERING TO 8K FEET WILL SPREAD INTO NW COLORADO THIS MORNING. MOUNTAINS MAY BECOME OBSCURED AS THE FRONT CROSSES THE REGION. SCT -SHRA/ISOLD -TSRA WILL SPREAD ACROSS THE HIGHER TERRAIN OF WRN COLORADO BY 18Z WEDNESDAY. SHOWERS END WEDNESDAY EVENING WITH CLEARING SKIES. && .FIRE WEATHER... ISSUED AT 922 PM MDT TUE JUN 17 2014 THE RED FLAG WARNING FOR TODAY WAS ALLOWED TO EXPIRE AT 900 PM...THOUGH LOCALIZED POCKETS OF CRITICAL WIND/HUMIDITY MAY PERSIST FOR ANOTHER HOUR OR SO IN ZONES 203...290...292...207 AHEAD OF A COLD FRONT. HOWEVER...A RED FLAG WARNING REMAINS IN EFFECT FOR FIRE WEATHER ZONE 207 BELOW 9500 FEET ON WEDNESDAY BETWEEN NOON AND 700 PM FOR CONTINUE GUSTY WEST TO SOUTHWEST WINDS AND LOW HUMIDITY. THE COLD FRONT SHOULD EVENTUALLY CLEAR THE AREA WEDNESDAY EVENING...AND WINDS ARE EXPECTED TO DECREASE BEHIND THIS FRONTAL PASSAGE. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING FROM NOON TO 7 PM MDT WEDNESDAY FOR COZ207. FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING FOR COZ002. UT...WINTER WEATHER ADVISORY UNTIL NOON MDT WEDNESDAY FOR UTZ023. && $$ UPDATE...PF SHORT TERM...NL LONG TERM...JAM AVIATION...JDC FIRE WEATHER...JAD
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
230 PM EDT WED JUN 18 2014 .SHORT TERM...TONIGHT THRU FRIDAY NIGHT... AXIS OF ATLC HIGH PRESSURE RIDGE SITS OFF THE GEORGIA COAST THIS AFTN WITH VERY WEAK ONSHORE/EASTERLY FLOW IN PLACE. WITH THE RIDGE AXIS IN PLACE THERE WILL BE LIMITED CONVECTION OVER SE GA WITH A MUCH DRIER AIRMASS IN PLACE. ACROSS NE FLORIDA THE SEABREEZE HAS KICKED IN. THE BEST MOISTURE (1.4" PW) AND SCATTERED CONVECTION IS FORECAST TO BE SOUTH OF A LINE FROM GREEN COVE SPRINGS TO SUWANNEE SPINGS WITH 12Z JAX SOUNDING AT A MEAGER 1.25" PW. THE ACTIVITY WILL LIKELY INCREASE IN AREAL COVERAGE AS IT PUSHES WESTWARD THROUGH THE AFTERNOON INTO THE VERY EARLY EVENING AND SHIFT TOWARD THE I-75 CORRIDOR IN THE LATE IN THE DAY WHERE HIGHER TSTM CHANCES SHIFT ALONG THE SEA BREEZE. DIURNAL INFLUENCES SHOULD KICK IN THIS EVENING WITH TSTMS/DAYTIME HEATING WANING AND SKIES CLEARING. WITH NEAR SFC MOISTURE IN PLACE IN CONCERT WITH DRY MID LEVELS...PATCHY FOG MAY BE POSSIBLE...BUT CONFIDENCE IS LOW WITH 10Z RAP DEPICTION SHOWING VERY LITTLE IN THE WAY OF FOG...BUT MORE CONFINED TOWARDS SW FLORIDA. ON THURSDAY...MOISTURE ASSOCIATED WITH AN UPPER LEVEL TROUGH/LOW PRESSURE AREA/ASSOCIATED VORT LOBE OVER THE SOUTHERN HALF OF FLORIDA PUSHES NORTHWARD. SUBSEQUENTLY RAIN CHANCES ACROSS SOUTHERN AREAS OF NORTHEAST FLORIDA WITH PWS RISING BETWEEN 1.60 TO ABOUT 1.80 INCHES BY LATE THURSDAY ACROSS THE SOUTHERN TIER OF THE CWA. HENCE...HAVE STRATIFIED POPS GRADIENT WITH 50% CHANCES ACROSS NORTH CENTRAL FLORIDA AND 20-30 POPS ACROSS THE ST. MARY`S RIVER TO TEEN CHANCES ACROSS THE ALTAMAHA. RIDGE OF HIGH PRESSURE REMAINS OVER THE AREA FRIDAY AND FRIDAY NIGHT...WITH SEA BREEZES LEADING TO WIDELY SCATTERED AFTERNOON/EVENING SHOWERS/T-STORMS...WITH SLIGHTLY GREATER COVERAGE EXPECTED SOUTH OVER N-CTRL FL WHERE GREATER MOISTURE WILL BE. ANOTHER HOT DAY FRI WITH LOW-MID 90S INTERIOR PORTION...AROUND 90 COASTAL COUNTIES EXCEPT UPPER 80S IMMEDIATE COAST. .LONG TERM...SATURDAY THRU TUESDAY... CHANCE OF AFTERNOON/EVENING SHOWERS/T-STORMS SAT/SUN WITH SEA BREEZES AND WEAK SURFACE TROF OVER SRN GA. HOT WEEKEND TEMPS WITH HI TEMPS LOW-MID 90S INLAND...AROUND 90 COAST...WITH LOW TEMPS IN LOW-MID 70S. WEAK ZONAL FLOW PATTERN OVER THE AREA EARLY NEXT WEEK WITH SCATTERED AFTERNOON/EVENING SHOWERS/T-STORMS EACH DAY PARTICULARLY ALONG SEA BREEZES AND OUTFLOW BOUNDARIES CREATED BY INITIAL STORMS THAT DEVELOP. LITTLE CHANGE IN TEMPERATURES WITH HIGHS AROUND 90 COAST...LOW-MID 90S INLAND AND LOWS IN THE LOW-MID 70S. && .AVIATION... TERMINALS EAST OF I-95 WILL HAVE VFR CONDITIONS THRU 18Z...WITH KGNV HAVING A POSSIBLE VCNTY TSTM BETWEEN 20-01Z THIS AFTN/EVE. PATCHY FOG IS EXPECTED AT KVQQ DURING THE PREDAWN HOURS AND VERY EARLY DAYLIGHT HOURS FOG INTERMITTENTLY REDUCING VSBYS TO MVFR. TOMORROW BEST CONVECTION WILL BE CONFINED TO THE SOUTHERN TIER OF JAX CWA WITH KGNV POSSIBLY HAVING TEMPO BKN CIG BASES OF 015-020 AGL THU AFTN BETWEEN 20-24Z. THURSDAY...TEMPORARY MVFR RESTRICTIONS WL BE POSSIBLE AT KGVN WITH SCT TSRA PERHAPS BRIEFLY FURNISHING IFR CONDS AND GUSTY WINDS FROM 20Z TO 01Z. && .MARINE...BENIGN CONDITIONS WILL PERSIST THROUGH FRIDAY WITH WEAK HIGH PRESSURE OVER THE AREA...RESULTING IN WIND SPEEDS GENERALLY 10 KTS OR LESS AND SEAS 2-3FT. THE HIGH WILL MOVE FARTHER OFFSHORE FRIDAY NIGHT THROUGH THE WEEKEND WHILE LOW PRESSURE DEVELOPS OVER THE MID ATLANTIC REGION...LEADING TO SOMEWHAT STRONGER SOUTHERLY FLOW OVER THE WATERS...BUT REMAINING BELOW ADVISORY CRITERIA. RIP CURRENTS: LOW RISK IS EXPECTED THROUGH FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 92 69 93 70 / 10 10 10 10 SSI 85 74 86 75 / 10 10 10 10 JAX 89 70 89 70 / 10 10 20 10 SGJ 84 72 85 74 / 20 20 30 10 GNV 89 69 90 69 / 40 20 50 30 OCF 89 69 90 70 / 40 20 50 40 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ WOLF/CORDERO
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
410 AM EDT WED JUN 18 2014 .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW THE NORTHERN STREAM FLOW DIVING FAR TO THE SOUTH ACROSS THE INTER-MOUNTAIN WEST AROUND A WELL-DEFINED UPPER LOW SPINNING JUST TO THE NORTH OF THE GREAT BASIN. THIS FLOW THEN FLATTENS TO A MORE ZONAL CONFIGURATION DOWNSTREAM ACROSS THE UPPER MIDWEST/GREAT LAKES AND NORTHEAST. THE SYNOPTIC PATTERN ALOFT CLOSER TO HOME HAS NOT CHANGED MUCH IN THE PAST 24 HOURS AS THE FORECAST AREA REMAINS BETWEEN AN AREA OF UPPER RIDGING TO OUR NORTH AND NORTHWEST...AND A CLOSE LOW/TUTT FEATURE NEAR THE FLORIDA EAST COAST/BAHAMAS. THIS INITIAL IMPULSE IS FORECAST BY NWP TO RETROGRADE ACROSS THE PENINSULA TODAY FOLLOWED BY A SECOND IMPULSE MOVING INTO SOUTH FLORIDA ON THURSDAY. NEITHER OF THESE FEATURE WILL ADD MUCH IN THE WAY OF SYNOPTIC SUPPORT FOR LIFT...HOWEVER WHAT WILL BE ARRIVING IS A MUCH MORE MOIST COLUMN COMPARED TO WHAT WAS SEEN ON TUESDAY. WE DID SEE A SCATTERING OF STORMS TUESDAY...BUT THE DRY AIR EVENTUALLY WON THE OVERALL BATTLE AND KEPT COVERAGE DOWN. WE ARE UNLIKELY TO HAVE THIS PROBLEM LATER TODAY AS THE MOISTURE SURGES BACK IN FROM THE EAST AND SOUTHEAST AHEAD OF THE UPPER IMPULSE. AT THE SURFACE...SUBTROPICAL RIDGE AXIS REMAIN ALIGNED JUST TO THE NORTH OF THE I-10 CORRIDOR...SUPPLYING OUR ZONES WITH A SYNOPTIC EAST TO SOUTHEAST LOW LEVEL FLOW. REGIONAL RADARS SHOW THE FL PENINSULA ITSELF ON THE DRY SIDE EARLY THIS MORNING. ANY SHOWERS AND STORMS ARE WELL OFFSHORE INTO THE GULF ALONG THE STILL WESTWARD MOVING EAST COAST SEA-BREEZE/CONVECTIVE OUTFLOW FROM OUR STORMS THIS PAST EVENING. && .SHORT TERM (TODAY AND TONIGHT)... THE FORECAST WILL CALL FOR A QUIET MORNING GIVING WAY TO AN ACTIVE THUNDERSTORM REGIME BY THE SECOND HALF OF THE AFTERNOON/EVENING. SIMILAR TO TUESDAY...STRONGER EASTERLY FLOW JUST ABOVE THE SURFACE THIS AFTERNOON IS SHOWN BY ALL THE HIGH RESOLUTION GUIDANCE MEMBERS TO ESSENTIALLY PIN THE SEA-BREEZE AT OR NEAR THE COAST. THEREFORE STORM INITIATION FOR EACH AREA SHOULD BE MAINLY DEPENDENT ON THE ARRIVAL TIMING OF THE EAST COAST SEA-BREEZE BOUNDARY ALONG THE WEST COAST. GENERALLY SPEAKING THIS INTERACTION WILL OCCUR FIRST DOWN OVER OUR SOUTHERN ZONES...SO THE GREATEST COVERAGE OF STORMS WILL GET GOING SOUTH OF HILLSBOROUGH/POLK COUNTIES EARLY TO MID AFTERNOON...AND THEN EXPAND NORTHWARD FOR THE LATE AFTERNOON AND EARLY EVENING HOURS. THE E-SE FLOW REGIME IS A FAVORED REGIME FOR NUMEROUS STORMS ALONG THE I-75 CORRIDOR...AS LONG AS THERE ARE NOT ANY SIGNIFICANT NEGATIVE FACTORS IN THE COLUMN. DO NOT SEE MUCH TODAY IN TERMS OF NEGATIVES. MID-LEVEL THETAE VALUES WILL RETURN TO NEAR OR EVEN A BIT ABOVE CLIMO BY THE PEAK CONVECTION HOURS...SO THERE SHOULD NOT BE MUCH IN THE WAY OF ADVERSE DRY AIR ENTRAINMENT INTO THE UPDRAFT COLUMNS. THE MOISTURE PROFILES WILL BE MOST CONDUCIVE TO SUPPORT DEEP CONVECTION FROM TAMPA BAY SOUTHWARD. THE REALLY MOIST CONDITIONS WILL SIMPLY TAKE A BIT LONGER TO REACH PORTIONS OF THE NATURE COAST. THEREFORE RAIN CHANCES WILL SHOW NEAR CLIMO FOR EASTERLY FLOW OVER THE NATURE COAST...30-50%...INCREASING TO AROUND 60% THROUGH THE TAMPA BAY AREA...AND THEN CLOSER TO 70% DOWN ALONG THE I-75 CORRIDOR OF THE THE SUN COAST. FURTHER INLAND TO THE SOUTH OF THE I-4 CORRIDOR (THROUGH EASTERN POLK/HIGHLANDS COUNTIES) WILL ALSO TAPER POPS DOWN A BIT AS WE GET AWAY FROM THE GREATEST CONVERGENCE/FOCUS ASSOCIATED WITH THE COLLIDING SEA-BREEZES. OVERALL SETUP IS NOT ALL THAT FAVORABLE FOR WET MICROBURST PRODUCTION. ANY LOCALIZED WIND THREATS LATER TODAY WILL BE ASSOCIATED WITH PRECIPITATION LOADING OF CONVECTIVE COLUMNS...AND THIS TYPE OF PHENOMENA TENDS TO ONLY OCCUR WITH THE VERY STRONGEST STORMS...AS OPPOSED TO TRUE WET MICROBURSTS WHICH ARE MORE ENVIRONMENTALLY DRIVEN. STORM TOP DIVERGENCE ASSOCIATED WITH THE STRONGER CELLS WILL BE A BIG CLUE AS TO WHICH ONES MIGHT POSE A WIND THREAT UPON COLLAPSE. WHILE WE DO HAVE SOME DECENT FLOW IN THE COLUMN BELOW 10,000 FEET TODAY...ABOVE THIS LEVEL THE FLOW IS QUITE LIGHT...AND ALMOST VARIABLE IN NATURE. THIS TENDS TO SUGGEST THAT THE STORMS TODAY WILL BE SLOW MOVERS...CAPABLE OF SOME LOCALLY VERY HEAVY RAINFALL AMOUNTS. OK...ENOUGH ABOUT THE DIURNAL STORMS. LETS TALK ABOUT TEMPERATURES. THEY WILL BE SEASONABLE...WITHIN A COUPLE DEGREES OF 90 FOR HIGHS. BACK TO CONVECTION AGAIN. SLOW MOVING STORMS WEAKEN AND MIGRATE OFFSHORE DURING THE EVENING HOURS ONCE AGAIN SETTING UP A MAINLY DRY OVERNIGHT PERIOD. THE WEAK UPPER LEVEL SUPPORT OF THE PASSING TROUGH SHOULD BE ENOUGH TO KEEP SCT CONVECTION GOING ACROSS THE COASTAL WATERS THROUGH THE OVERNIGHT PERIOD. LIKELY THESE STORMS WILL STAY AWAY FROM THE BEACHES AS THE FOCUS PUSHES INTO THE GULF WITH THE SYNOPTIC EASTERLY FLOW/LAND BREEZE. HAVE A SPLENDID WEDNESDAY EVERYONE! && .MID TERM (THURSDAY AND FRIDAY)... UPPER LEVEL RIDGING SPRAWLS ACROSS THE GULF COASTAL AND SOUTHEASTERN STATES WHILE AN INVERTED TROUGH LINGERS ALOFT ROUGHLY THE SOUTHERN HALF OF FL. ATLANTIC HIGH PRESSURE RIDGING INITIALLY ALONG LATITUDE 30 WESTWARD TO THE CENTRAL GULF COAST SAGS DOWN ACROSS CENTRAL FL. OF THE LATEST GFS AND ECMWF...18/00Z...THE GFS SEEMS THE MORE AGGRESSIVE. THE GFS UPPER TROUGH IS MORE ROBUST THAN THE ECMWF. BOTH MODELS HAVE A SURFACE TROUGH/LOW OVER FL OR THE EAST GULF BUT THE GFS IS THE MORE PRONOUNCED WHILE THE ECMWF HAS A MORE TRANSITORY FEATURE. FOR THIS FORECAST HAVE FAVORED THE ECMWF. EXPECT ISOLATED TO SCATTERED STORMS WITH THE MOST COVERAGE INLAND IN THE AFTERNOONS AND EARLY EVENINGS...THEN SLIDING OUT OVER THE GULF. THE LOW LEVEL FLOW WILL BE LIGHT AS IT SHIFTS FROM EASTERLY TO SOUTHEASTERLY...EXCEPT FOR ONSHORE FLOW NEAR THE COAST IN AFTERNOON SEA BREEZES. .LONG TERM (SATURDAY THROUGH NEXT TUESDAY)... THE UPPER LEVEL TROUGHINESS WEAKENS OVER THE AREA THROUGH THE WEEK- END THEN GIVES WAY TO RIDGING BUILDING IN FROM THE ATLANTIC MON AND TUE. THE SURFACE RIDGE ACROSS CENTRAL FL DROPS DOWN TO BETWEEN THE KEYS AND CUBA LATE IN THE WEEKEND THEN SLOWLY LIFTS BACK NORTH...REACHING CENTRAL FL AGAIN BY LATE TUE. ADEQUATE MOISTURE WILL CONTINUE WITH ISOLATED TO SCATTERED (30-40 POPS) STORMS. LOW LEVEL FLOW BECOMES SOUTHWEST AND WESTERLY (AS THE SURFACE RIDGE MOVES SOUTH) FOR MUCH OF THE PERIOD WITH THE HIGHEST STORM COVERAGE IN THE EARLY TO MID AFTERNOONS AND INLAND. && .AVIATION... VFR CONDITIONS PREVAIL ACROSS THE REGION EARLY THIS MORNING AND ARE EXPECTED TO PREVAIL THROUGH THE MAJORITY OF THE TAF PERIOD. SCATTERED TO NUMEROUS THUNDERSTORMS IS EXPECTED TO DEVELOP DURING THE AFTERNOON AND EVENING HOURS. STORMS WILL LIKELY INITIATE EARLY/MID AFTERNOON DOWN TOWARD KFMY/KRSW AND THEN DEVELOP NORTHWARD THE REMAINDER OF THE AFTERNOON/EARLY EVENING. SOME OF THE STORMS ARE LIKELY TO BE STRONG...ESPECIALLY LATE IN THE DAY AND THEN THE ACTIVITY IS EXPECTED TO MIGRATE OFFSHORE AFTER 01-02Z. STORMS TODAY AS LIKELY TO BE SLOW MOVERS RESULTING IN LONGER THAN TYPICAL THUNDERSTORM ASSOCIATED RESTRICTION. && .MARINE... THE SUBTROPICAL RIDGE AXIS WILL REMAIN IN POSITION TO THE NORTH OF THE FORECAST WATERS THROUGH THE NEXT COUPLE OF DAYS. THIS POSITION WILL RESULT IN A GENERAL EAST TO SOUTHEAST FLOW ACROSS THE COASTAL WATERS. THE SEA BREEZE IS EXPECTED TO DEVELOP NEAR THE COAST EACH AFTERNOON AND TURN WINDS LOCALLY ONSHORE. WINDS BECOME MORE VARIABLE LATE IN THE WEEK AS THE POTENTIAL EXIST FOR A WEAK LOW OR TROUGH TO DEVELOP OVER THE EASTERN GULF. THE EASTERLY FLOW TODAY WILL PROMOTE THE POTENTIAL FOR RAPID THUNDERSTORM DEVELOPMENT LATE IN THE AFTERNOON AND EARLY EVENING ALONG THE COAST. MARINERS SHOULD REMAIN WEATHER AWARE...KEEPING AN EYE TOWARD THE EASTERN SKY FOR DEVELOPING STORMS. && .FIRE WEATHER... HIGH PRESSURE WILL REMAIN CENTERED TO THE NORTH OF THE FORECAST AREA THROUGH THE NEXT SEVERAL DAYS. A GENERAL EAST TO SOUTHEAST FLOW WILL KEEP ATLANTIC MOISTURE STREAMING INTO THE REGION AND PREVENT ANY CRITICAL LEVELS OF RELATIVE HUMIDITY. IN ADDITION...INCREASING MOISTURE ALOFT WILL COMBINE WITH THE EASTERLY FLOW TO RESULT IN AN ACTIVE THUNDERSTORM PATTERN THE NEXT SEVERAL AFTERNOON. THE ACTIVITY TODAY AND THURSDAY SHOULD BE MOST CONCENTRATED ALONG THE I-75 CORRIDOR DURING THE MIDDLE AFTERNOON HOUR AND INTO THE EVENING. THE SEA BREEZE IS EXPECTED TO BE PINNED CLOSE TO THE COAST THE NEXT COUPLE OF DAYS WITH LITTLE INLAND PROGRESSION. FOG POTENTIAL...A FEW POCKETS OF SHALLOW GROUND FOG ARE POSSIBLE EARLY THURSDAY MORNING...BUT NO SIGNIFICANT OCCURRENCES OF FOG ARE ANTICIPATED. && && .PRELIMINARY POINT TEMPS/POPS... TPA 90 75 89 74 / 60 40 30 20 FMY 90 73 89 72 / 70 20 40 30 GIF 91 72 88 72 / 50 20 40 20 SRQ 91 73 88 73 / 60 40 30 20 BKV 93 70 91 69 / 40 40 30 10 SPG 90 77 89 76 / 60 40 30 20 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA MID TERM/LONG TERM...RUDE
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
147 AM EDT WED JUN 18 2014 .UPDATE... AN UPPER LEVEL LOW WILL CONTINUE OVER THE WESTERN ATLANTIC WATERS TODAY ALLOWING FOR TROPICAL MOISTURE TO CONTINUE TO WORK INTO SOUTH FLORIDA. SO WILL CONTINUE THE VCSH FOR THE EAST COAST TAF SITES THROUGH THE EARLY MORNING HOURS...BEFORE INTRODUCING VCTS FOR THE EAST COAST TAF SITES FOR THE DAY HOURS TODAY. THE WINDS WILL ALSO BE EASTERLY TODAY WITH SPEEDS AROUND 5 KNOTS THIS MORNING INCREASING TO 5 TO 10 KNOTS DURING THE DAY HOURS. FOR KAPF TAF SITE...THE WINDS WILL BE EASTERLY TODAY WITH SPEEDS AROUND 5 KNOTS THIS MORNING INCREASING TO 5 TO 10 KNOTS THIS AFTERNOON. THE KAPF TAF SITE WILL REMAIN DRY THROUGH THE EARLY MORNING HOURS BEFORE INTRODUCING VCSH FOR THE MORNING HOURS. VCTS WILL THEN BE ADDED FOR THE AFTERNOON HOURS AT KAPF TAF SITE. THE CEILING AND VIS WILL REMAIN IN VFR CONDITIONS TODAY FOR ALL OF THE TAF SITES ACROSS SOUTH FLORIDA...AS THE TIMING OF THE SHOWERS AND THUNDERSTORMS IS NOT KNOWN AT THIS TIME. LATER ON....A TEMPO WILL BE ADDED TO THE TAF SITES ACROSS SOUTH FLORIDA WHEN WE KNOW BETTER TIMING OF THE SHOWER AND THUNDERSTORM ACTIVITY. && .UPDATE...54/BNB .PREV DISCUSSION... /ISSUED 831 PM EDT TUE JUN 17 2014/ UPDATE... LATEST HIGH RESOLUTION MODELS ARE NOT INITIALIZING THE LARGE PRECIPITATION SHIELD ACROSS THE OFFSHORE ATLANTIC WATERS VERY WELL. LATEST RADAR TRENDS SHOW THIS SHIELD MOVING TO THE WEST- NORTHWEST VERY SLOWLY. MODERATE RAIN BANDS EMANATING OUT AHEAD ARE MOVING INTO EXTREME SOUTHERN MIAMI-DADE COUNTY. UPDATED POPS TO ACCOUNT FOR THE LATEST TRENDS. BELIEVE MOST OF THIS PRECIPITATION MAY LINGER THROUGH MUCH OF THE NIGHT BEING FED BY DEEP MOISTURE AND AN UPPER TROUGH DRAPED ACROSS THE AREA. && .PREV DISCUSSION... /ISSUED 754 PM EDT TUE JUN 17 2014/ AVIATION... LEFTOVER CONVECTION REMAINS ACROSS THE ATLANTIC WATERS EARLY THIS EVENING IN ASSOCIATION WITH AN UPPER LOW ACROSS THE AREA. THIS ACTIVITY IS SLOWLY PUSHING WEST-NORTHWEST BUT TENDS TO BE WEAKENING AS IT NEARS THE FLORIDA MAINLAND. HOWEVER...THERE IS STILL CONCERN THAT KMIA AND KTMB MAY BE AFFECTED OVER THE NEXT FEW HOURS. KEPT PRECIP MENTION OUT OF TAFS FOR NOW BUT WILL AMEND AS NECESSARY. && PREV DISCUSSION... /ISSUED 221 PM EDT TUE JUN 17 2014/ DISCUSSION... INTERESTING WEATHER PATTERN TODAY. THE UPPER LEVEL TROUGH HAS BROUGHT THE INSTABILITY EXPECTED. HOWEVER, THUNDERSTORMS THIS MORNING CAUSED AN OUTFLOW BOUNDARY THAT MOVED ACROSS SOUTH FLORIDA. AS IT DID, IT CAUSED THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN THE WESTERN HALF OF THE CWA. THIS FORMED A DONUT HOLE SHAPE OF PRECIPITATION THAT HAS KEPT MOST OF THE SHOWERS OUT OF THE MIAMI DADE AREA. LOOKING AT CURRENT RADAR IMAGERY, THE CONVECTION OVER THE ATLANTIC IS BEGINNING TO DISSIPATE AND THE LINE OVER THE GULF SIDE IS BEGINNING TO BE ENHANCED. HOWEVER, GIVEN THE CLOUD COVER AND CONDITIONS, EXPECT THE SHOWERS AND GENERAL THUNDERSTORMS TO BE THE RULE TODAY, WITH ONLY SLIGHT CHANCES OF STRONG THUNDERSTORMS DEVELOPING, AND THOSE SHOULD BE ON THE GULF SIDE. THIS PATTERN IS SHOWN FAIRLY WELL BY THE HRRR 15Z RUN. SEE NO REASON TO DISAGREE WITH THE MODELS SOLUTION FOR THIS AFTERNOON. HAVE HIGHER POPS ALONG THE GULF COAST AND STILL MAINTAINING LOW END CHANCE POPS FOR THE ATLANTIC COAST, EXCEPT FOR PALM BEACH, WHERE HIGH END CHANCE AS SHOWERS ARE STILL IN THAT AREA. ACTIVE WEATHER WILL CONTINUE THROUGH THE REMAINDER OF THE WEEK AS AN UPPER LEVEL LOW HANGS AROUND OVER THE FLORIDA PENINSULA. A SURFACE HIGH, TO THE NORTHEAST, WILL SLOWLY STRENGTHEN THIS WEEK AND CAUSE THE SFC WINDS TO FLUCTUATE BETWEEN SOUTHERLY AND EASTERLY. THIS WILL KEEP MUCH OF THE CONVECTION IN THE INTERIOR AND GULF COAST THIS WEEK, WITH SOME NOCTURNAL AND EARLY TO MID MORNING ACTIVITY ALONG THE ATLANTIC COAST EACH DAY. LONG TERM... THE HIGH OVER NORTHERN FLORIDA WILL START TO MOVE SOUTHWARD THIS WEEKEND...AS A TROUGH OF LOW PRESSURE DEVELOPS OVER THE EASTERN UNTIED STATES. THIS WILL ALLOW FOR THE STEERING FLOW TO BECOME MORE SOUTHERLY OVER SOUTH FLORIDA THIS WEEKEND FOCUSING THE HIGHEST POPS OVER THE LAKE OKEECHOBEE REGION. THE HIGH WILL CONTINUE TO MOVE SOUTH INTO THE FLORIDA STRAITS EARLY NEXT WEEK...AS THE TROUGH OF LOW PRESSURE CONTINUES TO BUILD INTO THE EASTERN UNITED STATES. THIS WILL ALLOW FOR THE STEERING FLOW TO BECOME MORE SOUTHWEST OVER SOUTH FLORIDA EARLY NEXT WEEK FOCUSING THE HIGHEST POPS OVER THE EASTERN AREAS OF SOUTH FLORIDA. MARINE... AN UPPER LEVEL LOW WILL KEEP CONVECTIVE ACTIVITY OVER ALL SOUTH FLORIDA WATERS THROUGH THE WEEK. A SURFACE HIGH TO THE NORTHEAST WILL KEEP AN EAST TO SOUTH SOUTHEAST FLOW ACROSS THE WATER FOR THE TIME BEING. SEA SHOULD BE 1 TO 3 FEET THROUGH THE WEEK FOR THE ATLANTIC WATERS, WITH THE GULF SEEING SEA OF 1 TO 2 FEET. CONDITIONS UNDER CONVECTIVE SHOWERS OR THUNDERSTORMS COULD BECOME ROUGH AT TIMES. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 75 84 74 89 / 30 50 20 40 FORT LAUDERDALE 76 84 75 89 / 30 50 20 30 MIAMI 76 85 75 90 / 30 50 20 40 NAPLES 73 86 73 89 / 50 50 20 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...30/KOB LONG TERM....13/SI
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
606 AM EDT WED JUN 18 2014 .SYNOPSIS... HIGH PRESSURE WILL BE CENTERED SOUTH AND EAST OF THE FORECAST AREA THROUGH THE WEEKEND. A WEAK TROUGH IN THE FORECAST AREA WILL BECOME MORE PRONOUNCED OVER THE WEEKEND. HIGH PRESSURE ALOFT WILL BEGIN TO WEAKEN FRIDAY. THE PATTERN SUPPORTS ABOVE NORMAL TEMPERATURES. ISOLATED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL OCCUR TODAY AND THURSDAY. SOMEWHAT GREATER THUNDERSTORM COVERAGE WILL OCCUR OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... THE SURFACE RIDGE WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. ALOFT...THE PRESSURE RIDGE WILL CONTINUE. CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH AND ALONG THE SEA-BREEZE FRONT...A WEAK SHORTWAVE TROUGH CAUGHT IN THE H5 RIDGE...PLUS STRONG HEATING MAY HELP SUPPORT THUNDERSTORMS. HOWEVER...EXPECT JUST ISOLATED COVERAGE BECAUSE OF SHALLOW MOISTURE AND GENERAL UPPER RIDGING. THE 07Z HRRR DISPLAYS JUST ISOLATED COVERAGE THIS AFTERNOON IN THE EXTREME NORTHWEST PART OF THE FORECAST AREA. THE GFS AND NAM MOS POPS ARE MAINLY 10 PERCENT OR LESS. THE TEMPERATURE GUIDANCE WAS CLOSE BUT MAY BE A LITTLE TOO COOL... ESPECIALLY WITH THE LOW TEMPERATURES. THE GUIDANCE HAS TRENDED WITH A COOL BIAS...BUT HAS BEEN CLOSER THE PAST COUPLE OF DAYS. HAVE GENERALLY USED THE HIGH TEMPERATURE GUIDANCE AND WENT A FEW DEGREES ABOVE THE LOW TEMPERATURE GUIDANCE. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... SURFACE HIGH PRESSURE WILL CONTINUE SOUTH AND EAST OF THE FORECAST AREA. THE UPPER RIDGING WILL CONTINUE. STRONG HEATING AND CONVERGENCE INTO A LEE-SIDE TROUGH AND ALONG THE SEA-BREEZE FRONT MAY HELP SUPPORT THUNDERSTORMS BUT EXPECT LITTLE COVERAGE BECAUSE OF SHALLOW MOISTURE AND THE UPPER RIDGING. THE NAM AND GFS MOS ARE CONSISTENT WITH VERY LOW POPS. USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF THE RECENT COOL BIAS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... THE GFS AND ECMWF DISPLAY THE UPPER RIDGE WEAKENING FRIDAY AND SATURDAY. A SURFACE TROUGH IN THE FORECAST AREA APPEARS TO BECOME MORE DOMINATE. THE PATTERN SUPPORTS ABOVE NORMAL TEMPERATURES AND SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. THE GFS ENSEMBLE MEAN SUPPORTS A POP AROUND 20 PERCENT FRIDAY...AND 30 PERCENT DURING THE REST OF THE MEDIUM-RANGE PERIOD. THE GFS...ECMWF...AND EKD MOS ALSO GENERALLY SUPPORTED THESE POPS. MOST OF MOS HAS TEMPERATURES REMAINING ABOVE CLIMATOLOGY DURING THE PERIOD. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... LITTLE CHANGE IN THE OVERALL WEATHER PATTERN EXPECTED THROUGH THE TAF PERIOD...SO WILL CONTINUE WITH PERSISTENCE. UPPER RIDGE IN THE VICINITY...WITH SURFACE RIDGE AXIS TO OUR SOUTH AND TROUGH TO OUR NORTH. MVFR/BRIEF IFR FOG POSSIBLE AT AGS AND OGB UNTIL AROUND 13Z THIS MORNING. BETTER MOISTURE TO THE NORTH WILL PROVIDE BETTER DIURNAL CONVECTIVE COVERAGE MAINLY NORTH OF THE TERMINALS LATER THIS AFTERNOON AND EVENING...SO CHANCE OF TSRA AFFECTING TERMINALS TOO LOW TO INCLUDE IN THE TAFS AT THIS TIME. EXTENDED AVIATION OUTLOOK...LITTLE CHANGE THURSDAY. EARLY MORNING FOG POSSIBLE...MAINLY AT FOG PRONE SITES AGS/OGB...WITH ISOLATED AFTERNOON THUNDERSTORMS MAINLY NORTH OF THE TERMINALS. BETTER CHANCE OF DIURNAL THUNDERSTORMS FRIDAY THROUGH SUNDAY AS UPPER RIDGE GIVES WAY TO UPPER TROUGH...AND SURFACE TROUGH WITH BETTER MOISTURE SLIPS SOUTH INTO THE REGION. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
705 PM CDT THU JUN 19 2014 .MESOSCALE DISCUSSION... 506 PM CDT ORGANIZED QLCS IS APPROACHING THE MISSISSIPPI RIVER AT THIS TIME WITH SOME MESOSCALE ORGANIZATION EVIDENT WITH MCV AT THE NORTHERN FLANK OF THE LINE. KDVN WSR-88D VWP SHOWS SLIGHT STRONGER FLOW ALOFT THAN RAP SUGGESTS AND RAP DOESNT SEEM TO HAVE A GOOD HANDLE ON THE ONGOING SITUATION...WHICH RESULTS IN SOMEWHAT LOWER THAN AVERAGE CONFIDENCE IN HOW THINGS WILL PLAY OUT THIS EVENING. THERE HAS BEEN EVIDENCE OF OUTFLOW BEGINNING TO SURGE OUT AHEAD OF THE LINE...BUT WITH AMPLE INSTABILITY PRESENT AHEAD OF THE LINE AND SOME MESOSCALE ORGANIZATION NOT THINKING THAT ANY WEAKENING OF THE LINE WITH BE MORE GRADUAL THE NEXT HOUR OR TWO. CURRENT RADAR/OBSERVATIONAL TRENDS ARE SOMEWHAT CONCERNING REGARDING THE SHORT TERM (0-6 HOUR) FLASH FLOOD THREAT. LEFT OVER SURFACE BOUNDARY EXTENDING FROM INDIANAPOLIS NORTHWEST TO NEAR DUBUQUE IS BEGINNING TO LIGHT UP ACROSS ILLINOIS WEST OF THE NW INDIANA CONVECTION. KILX VWP SHOWS ABOUT 15 INCREASING TO 20KT SSW FLOW AROUND 850MB WHICH RIDING OVER THE BOUNDARY SEEMS TO BE SUPPORTING THE RECENT UPTICK IN CONVECTIVE ACTIVITY ALONG THIS BOUNDARY EXTENDED SOUTHEAST FROM THE MS RIVER QLCS. SHORT TERM CONVECTIVE TRENDS WOULD SEEM TO SUPPORT A CONTINUED FILLING IN OF THE LINE FROM WHITESIDE COUNTY EAST SOUTHEAST TO BENTON COUNTY...WITH THIS ENTIRE AXIS MOVING GRADUALLY NORTHEAST THE NEXT COUPLE OF HOURS. WARM CLOUD DEPTH IN EXCESS OF 3500M AND PWATS NEARING 2 INCHES...WHICH IS ROUGHLY THE 99TH PERCENTILE FOR THIS TIME OF YEAR...WILL CONTINUE TO SUPPORT VERY EFFICIENT RAINFALL PRODUCING CONVECTION. THE COMBINATION OF THE WAA WING OF DEVELOPING THUNDERSTORMS IN CONJUNCTION WITH THE EASTWARD MOVING QLCS COULD EASILY SUPPORT ISOLATED RAINFALL TOTALS OVER 3 INCHES IN LESS THAN 2 HOURS WHICH IS WELL ABOVE FLASH FLOOD GUIDANCE...PARTICULARLY IN AREAS WHICH SAW HEAVY RAIN WEDNESDAY EVENING. CURRENT FLASH FLOOD WATCH ACCURATELY DEPICTS THE HIGHEST THREAT AREA FOR FLASH FLOODING HEADING INTO THE EARLY EVENING...HOWEVER WILL CONTINUE TO MONITOR CONVECTIVE TRENDS THE NEXT COUPLE HOURS FOR POSSIBLE NEED FOR AN EASTWARD EXPANSION OF THE CURRENT WATCH. IZZI && .DISCUSSION... 302 PM CDT SYNOPSIS...ANOTHER ROUND OF STORMS IS EXPECTED THIS AFTERNOON AND TONIGHT...FOLLOWED BY A QUIETER DAY TOMORROW. HOWEVER THE PATTERN REMAINS BUSY NEXT WEEK. TEMPERATURES WILL BE AT OR ABOVE NORMAL AWAY FROM THE LAKE THROUGH AT LEAST EARLY NEXT WEEK. WILL CONTINUE TO CARRY A FLASH FLOOD WATCH FOR LEE...OGLE...AND WINNEBAGO COUNTIES THROUGH TONIGHT. REST OF TODAY THROUGH FRIDAY NIGHT... WE ARE UNDER AN UPPER LEVEL RIDGE BUT AN UPPER LEVEL SHORTWAVE IS MOVING NORTHEAST AND IS CURRENTLY OVER MISSOURI. AT THE SURFACE HIGH PRESSURE IS OVER JAMES BAY AND THE EASTERN GREAT LAKES WHILE A BROAD LOW IS OVER THE NORTHERN PLAINS. A STATIONARY BOUNDARY IS ACROSS THE SOUTHERN CWA ROUGHLY FROM MOLINE THROUGH CENTRAL IL AND THEN BACK THROUGH THE CENTRAL APPALACHIANS. WE HAVE RECOVERED NICELY THIS AFTERNOON WITH AMDAR SOUNDINGS SHOWING ELEVATED CAPE. SHEAR IS WEAK AT BEST AS IS GENERAL STORM FLOW. SHOWERS AND STORMS HAVE FORMED ALONG THE BOUNDARY AND OVER SOUTHERN LAKE MI. IN GENERAL THE STORMS ARE SLOW MOVERS AROUND 15 MPH. WITH PWAT VALUES STILL HIGH IN EXCESS OF 1.5 INCHES...ANY GIVEN STORM WILL PRODUCE A HEAVY DOWNPOUR. COMBINE THAT WITH THEIR SLUGGISH MOVEMENT AND WE WILL PROBABLY HAVE ANOTHER ROUND OF WATER PROBLEMS TO DEAL WITH. MAY ALSO SEE GUSTY WINDS AND SMALL HAIL FROM THE STRONGEST STORMS BUT ONLY EXPECTING A FEW TO PULSE UP HIGH ENOUGH TO WARRANT A SPS OR WARNING. ORGANIZED STORMS ARE NOT ANTICIPATED DUE TO THE WEAK WIND SHEAR. ISOLATED TO SCATTERED SHOWERS WILL FIRE ALONG THE BOUNDARY THIS AFTERNOON AND THEN DIMINISH THIS EVENING. THE LINE OF STORMS CURRENTLY OVER IOWA WILL SHIFT EAST ACROSS THE AREA TONIGHT BRINGING ANOTHER ROUND OF HEAVY RAIN. AS MENTIONED ABOVE WILL KEEP THE FLASH FLOOD WATCH GOING FOR LEE...OGLE...AND WINNEBAGO COUNTIES. GUIDANCE INDICATES STORM MOTION WILL WEAKEN EVEN FURTHER TONIGHT LEADING TO EVEN SLOWER MOVING STORMS. ON THE OTHER HAND...GUIDANCE HINTS AT THE LINE DISSIPATING AS IT MOVES THROUGH THE REGION. THOUGHT ABOUT EXPANDING THE FLASH FLOOD WATCH EAST TO BOONE AND DEKALB COUNTIES BUT GIVEN MY UNCERTAINTY IN HOW FAR EAST THE HEAVY RAIN WILL GET...DID NOT EXPAND WITH THIS ISSUANCE. THE LINE CONTINUES TO THE EAST TOMORROW WITH CLEARING CONDITIONS BEHIND IT. ONCE THE SHOWERS AND STORMS SHIFT EAST...TOMORROW LOOKS LIKE A NICE DAY. HIGHS WILL BE IN THE MID 80S AWAY FROM THE LAKE. A LAKE BREEZE WILL KEEP AREAS NEAR THE LAKE IN THE 70S. FRIDAY NIGHT MAY COMPLETELY DRY...BUT GUIDANCE SUGGESTS LAKE EFFECT SHOWERS MAY FORM AND PUSH INLAND OVERNIGHT. HAVE LOW CONFIDENCE IN THESE LAKE EFFECT SHOWERS. SATURDAY THROUGH MONDAY... WEAK HIGH PRESSURE SETS UP OVER THE REGION SATURDAY BUT IT IS QUICKLY PUSHED EAST BY A LOW THAT PASSES WELL TO THE NORTH SUNDAY AND MONDAY. SATURDAY MAY BE DRY AND SIMILAR TO TODAY...A STATIONARY BOUNDARY MAY BE OVER THE CWA SATURDAY SO HAVE A SLIGHT CHANCE OF SHOWERS AND STORMS. OVERALL THINKING IT WILL BE MOSTLY DRY. HIGHS ON SATURDAY WILL BE IN THE MID TO UPPER 80S AWAY FROM THE LAKE WITH ON SHORE FLOW KEEPING AREAS ALONG THE LAKE IN THE 70S. PRECIP CHANCES INCREASE OVER THE WEEKEND AS A LOW PRESSURE TROUGH ASSOCIATED WITH A LOW THAT PASSES WELL TO OUR NORTH MOVES THROUGH THE REGION. THE BEST CHANCE FOR SHOWERS AND STORMS WILL BE ALONG THE TROUGH/COLD FRONT MONDAY/MONDAY NIGHT. COULD SEE ANOTHER ROUND OF HEAVY RAIN AS GUIDANCE FEATURES PWATS AROUND 1.8 INCHES. TEMPS WILL BE VERY SIMILAR SUNDAY AND MONDAY WITH HIGHS IN THE MID 80S AND LITTLE TO NO LAKE COOLING. TUESDAY AND WEDNESDAY... AN UPPER LEVEL TROUGH MOVES OVER THE REGION TUESDAY AND WEDNESDAY. GUIDANCE DIFFERS ON HOW COOL IT WILL GET UNDER THE TROUGH. RIGHT NOW HAVE HIGHS IN THE LOWER 80S TO UPPER 70S WHICH WOULD BE A NICE BREAK FROM THE HEAT. KEPT CHANCES OF SHOWERS AND STORMS IN THE FORECAST AS THE TROUGH MOVES THROUGH WITH MULTIPLE VORTICITY STREAMERS. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * TSRA THIS EVENING...WITH ERRATIC/WESTERLY WINDS FROM OUTFLOWS. * BRIEF IFR/MVFR CIGS/VIS WITH TSRA. * ADDITIONAL SHRA/TSRA OVERNIGHT/FRIDAY MORNING. * POSSIBLE IFR/LOW MVFR CIGS FRIDAY MORNING. * FOG/HAZE TONIGHT/FRIDAY MORNING. * LAKE BREEZE FRIDAY AFTERNOON. CMS //DISCUSSION...UPDATED 00Z... LINE OF TSRA HAS FILLED IN FROM IKK TO RPJ TO RFD. THIS ENTIRE LINE WILL MOVE NORTHEAST ACROSS THE TERMINALS OVER THE NEXT SEVERAL HOURS AND CARRIED PREVAILING TSRA FOR 2-3 HOURS AND WILL TWEAK AS TRENDS EMERGE. POSSIBLE INITIAL TSRA MAY TREND TO MORE SHRA WITH EMBEDDED TSRA SO CURRENT END TIMES OF 430Z MAY BE TOO LONG. HEAVIEST TSRA WILL PRODUCE IFR CIGS/VIS WITH VIS POSSIBLY UNDER 1SM FOR A SHORT TIME. TSRA ALSO PUSHING WEAK OUTFLOWS OF 15-20KTS FROM THE WEST OR SOUTHWEST SO BRIEF WIND SHIFTS AND ERRATIC WINDS ARE EXPECTED WITH THESE STORMS. AFTER THIS WAVE OF ACTIVITY MOVES THROUGH...MODELS SUGGEST ANOTHER LINE OF SHRA/TSRA WILL DEVELOP OVERNIGHT AND CONTINUE INTO FRIDAY MORNING. CONFIDENCE REGARDING THIS DEVELOPMENT AND TIMING IS LOW BUT TRENDS ARE CONSISTENT ENOUGH TO INCLUDE MENTION IN THIS FORECAST. PREVAILING EASTERLY WINDS THIS EVENING WILL TURN MORE SOUTHEAST OVERNIGHT...SOUTHERLY BY MORNING THEN WESTERLY MID/LATE FRIDAY MORNING. WITH THE GRADIENT DIMINISHING SOME IN THE AFTERNOON...A LAKE BREEZE IS EXPECTED BY MID/LATE AFTERNOON SHIFTING WINDS TO THE NORTHEAST. WITH LOW LEVELS BECOMING SATURATED OVERNIGHT...THERE IS SOME POTENTIAL FOR LOWER CIGS...POSSIBLY IFR BUT NOT EXPECTING THEM TO BE AS WIDESPREAD AS THIS MORNING AND FOR NOW ONLY HAVE SCATTERED PREVAILING MENTION. CMS //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH FOR TSRA THIS EVENING. * LOW FOR ADDITIONAL SHRA/TSRA OVERNIGHT/FRIDAY MORNING. * MEDIUM FOR FOG/HAZE OVERNIGHT/FRIDAY MORNING. * LOW FOR IFR/MVFR CIGS FRIDAY MORNING. * MEDIUM FOR WINDS THROUGH FRIDAY AFTERNOON. * HIGH FOR A LAKE BREEZE FRIDAY AFTERNOON/MEDIUM FOR TIMING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... * SATURDAY THROUGH WEDNESDAY...CHANCE OF TSRA. && .MARINE... 210 PM CDT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED ACROSS THE LAKE TONIGHT AS A MID LEVEL DISTURBANCE MOVES ACROSS THE AREA INTO FRIDAY. A WEAK SURFACE LOW...AND FRONTAL ZONE WILL SHIFT ACROSS THE SOUTHERN END OF THE LAKE ON FRIDAY. THIS WILL RESULT IN AN EAST SOUTHEASTERLY WIND OVER THE LAKE INTO FRIDAY...FOLLOWED BY A PERIOD OF NORTHERLY WINDS ON THE SOUTH END OF THE LAKE FRIDAY NIGHT INTO SATURDAY. ADDITIONAL PERIODS OF FOG ARE POSSIBLE DURING THE PERIOD AS HIGH DEWPOINT AIR REMAINS OVER THE LAKE. WE WILL...HOWEVER...LET THE CURRENT FOG ADVISORY EXPIRE AS AREA OBSERVATIONS AND WEB CAMS INDICATE THAT VISIBILITIES HAVE IMPROVED. THE WEATHER PATTERN IN THE EXTEND PERIOD LOOKS REMAIN SOMEWHAT ACTIVE AT TIMES...ESPECIALLY EARLY NEXT WEEK. DURING THIS TIME IT APPEARS ANOTHER WEATHER SYSTEM COULD PRODUCE MORE THUNDERSTORM ACTIVITY OVER THE LAKES REGION. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ008-ILZ010 UNTIL 7 AM FRIDAY. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
131 PM CDT WED JUN 18 2014 .DISCUSSION... 944 AM CDT A LINE OF SHOWERS AND STORMS IS MOVING TROUGH NORTH CENTRAL ILLINOIS THIS MORNING. ON IR SATELLITE...IN GENERAL THE SYSTEM IS WARMING ALOFT BUT ISOLATED STORMS ARE SHOWING PERIODIC STRENGTHENING. LAPSE RATES ALOFT WILL CONTINUE TO SUPPORT THUNDERSTORMS BUT IN GENERAL THINKING THE ATMOSPHERE IS TOO STABLE FOR SEVERE STORMS. MAY SEE AN ADDITIONAL STORM OR TWO PULSE UP AND PRODUCE SPECIAL WEATHER STATEMENT WORTHY GUSTS...BUT IN GENERAL EXPECTING THE LINE TO GRADUALLY DECLINE AS IT MOVES THROUGH NORTHERN IL AND NW INDIANA. WITH THE EXTENSIVE CLOUD COVER OVERHEAD...HAVE VERY LOW CONFIDENCE IN THE FORECAST FOR THIS AFTERNOON. NO GUIDANCE MEMBER HAS PICKED UP THIS MORNING/S LINE OF STORMS. IF THE CLOUDS STICK AROUND...IT WILL BE VERY DIFFICULT TO DESTABILIZE AND COULD SEE A COOLER AND DRIER DAY THAN EXPECTED. BUT IF CLOUDS THIN OUT BEHIND THE STORMS...HOT CONDITIONS AND SCATTERED STORM DEVELOPMENT IS MORE LIKELY. THE CLOUDS ARE THINNING OVER IOWA THIS MORNING SO FOR NOW DECIDED TO KEEP A CHANCE OF THUNDER GOING IN THE FORECAST. GIVEN THE STATIONARY BOUNDARY TO OUR NORTH...KEPT THE GREATEST CHANCE ALONG THE IL/WI STATE LINE. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * WIND DIRECTION AND SPEED TRENDS THROUGH THIS EVENING...WITH NORTHEAST WINDS AROUND 10 KT LIKELY RETURNING LATE AFTN/EARLY EVE. * ADDITIONAL SHRA/TSRA POTENTIAL THIS EVENING/TONIGHT AND ON THURSDAY. * CHANCE FOR LOWER CIGS TONIGHT. * EAST-NORTHEAST WINDS ON THURSDAY. RC //DISCUSSION...UPDATED 18Z... LARGE TSRA COMPLEX HAS PUSHED SOUTH OF THE TERMINALS...LEAVING A VERY CHAOTIC WIND FIELD IN ITS WAKE. THIS COMPLEX HAS ALSO STABILIZED THE AIR MASS OVER THE AREA AND THROWN INTO DOUBT CONVECTIVE TRENDS THE REMAINDER OF THE DAY INTO TONIGHT. IF THE ATMOSPHERE CAN CLEAR AND RECOVER ENOUGH...ANOTHER SHORTWAVE MAY TOUCH OFF TSRA EARLY THIS EVENING. HAVE MAINTAINED TEMPO GROUP IN TAFS FOR NOW...BUT ITS CONCEIVABLE THAT CHANCES FOR ADDITIONAL TSRA HAVE BEEN GREATLY REDUCED BY THE STORMS THAT HAVE ALREADY MOVED THROUGH. WINDS ARE GENERALLY SOUTHEAST OUT TOWARD RFD...BUT HAVE VERY LOW CONFIDENCE IN WIND TRENDS INTO THE LATE AFTERNOON FOR THE EASTERN TERMINALS. THERE IS A GOOD DEAL OF VARIABILITY IN OBSERVED WINDS IN NE IL...NW IN AND SRN WI...BUT OVERALL SPEEDS HAVE COME DOWN AND SHOULD BE FAIRLY LIGHT. A SHIFT TO STRONGER NORTHEAST WINDS AROUND 10 KT IS STILL EXPECTED LATE THIS AFTERNOON INTO THE EARLY EVENING FOR THE EASTERN TAF SITES. SOME GUIDANCE INDICATES POTENTIAL FOR LOWER CIGS TONIGHT...BUT HAVE NOT INCLUDED ANY MVFR OR IFR IN THE TAF. ON THURSDAY...WINDS ARE EXPECTED TO BE EAST AND NORTHEAST CLOSER TO LAKE MICHIGAN AND SOUTHEAST IN NORTH CENTRAL IL. COULD SEE SPEEDS AROUND OR OVER 10 KT AT TIMES AT ORD/MDW/GYY. THE AIR MASS OVER THE AREA WILL REMAIN UNSTABLE ESPECIALLY ALOFT...SO AN UPPER LEVEL DISTURBANCE MAY BE ABLE TO TOUCH OFF ANOTHER ROUND OF SHRA/TSRA. HAVE INCLUDED A PROB30 GROUP IN THE TAF...WITH FAIRLY LOW CONFIDENCE IN TIMING AND COVERAGE. BETTER TSRA CHANCES COULD END UP MAINLY AWAY FROM LAKE MI...INCLUDING RFD AREA...DUE TO MARINE INFLUENCE EXPECTED CLOSER TO THE LAKE. RC //ORD AND MDW CONFIDENCE...UPDATED 18Z... * LOW IN WIND DIRECTION TRENDS THROUGH MID AFTERNOON...MEDIUM IN SHIFT TO NORTHEAST WINDS AROUND 10 KT LATE THIS AFTERNOON. * LOW IN TSRA TRENDS THE REMAINDER OF THE PERIOD. * HIGH IN EAST-NORTHEAST WINDS ON THURSDAY...MEDIUM IN SPEEDS. RC //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR WITH PERIODIC CHANCES FOR THUNDERSTORMS. BMD && .MARINE... 247 AM CDT A FRONTAL BOUNDARY WILL LINGER IN THE VICINITY OF LAKE MICHIGAN THROUGH THE REMAINDER OF THE WEEK. IN GENERAL...SOUTH WINDS ARE EXPECTED SOUTH OF THE BOUNDARY WITH NORTHEAST WINDS NORTH OF THE BOUNDARY. THE FRONT IS EXPECTED TO SAG SOUTH ACROSS LAKE MICHIGAN TODAY...THEN LIFT BACK NORTH AGAIN THURSDAY INTO FRIDAY. HIGH PRESSURE WILL BUILD JUST EAST OF LAKE MICHIGAN LATE IN THE WEEK INTO THE WEEKEND AND SHOULD RESULT IN RELATIVELY MODEST WINDS ACROSS THE LAKE THIS WEEKEND INTO EARLY NEXT WEEK. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 108 PM CDT Wed Jun 18 2014 .DISCUSSION... ISSUED 1045 AM CDT Wed Jun 18 2014 A line of storms has reached Knox county and will be moving into an unstable airmass with decreasing CIN and CAPE values approaching 3000 J/kg. Expect the line to move primarily east as individual storms drift southeast. Based on HRRR 3km and NCEP 4km output, it appears the southern extent of the line as it progresses east should generally remain north of a line from Rushville to Lincoln to Champaign. We kept daytime chance PoPs confined to that general area. That line it projected to remain sub-severe for the most part during the day. Severe potential looks higher tonight as a complex of storms develops to our north along the stationary front and rides over the upper level ridge into N IL this evening. That complex is projected to curve to the ESE tonight and dissipate as it reaches Lincoln to Champaign shortly after midnight. Varying solutions high resolution models lead to lower confidence on any one solution, but that appears to be closer to the consensus at this point. Temperatures today will climb into the lower 90s in most areas. The current line of storms will produce a cold pool that will spread across the northern third of counties, but some sun later this afternoon should boost even those areas back toward the low 90s. Dewpoints will reside in the low 70s all day as well, making for very humid conditions. Heat index readings will approach 100 degrees in areas that remain sunny through the day, mainly south of Lincoln. Updates this morning were mainly to the weather and PoP grids, with minor adjustments to temps. Updated info will be available shortly. Shimon && .AVIATION... ISSUED 100 PM CDT Wed Jun 18 2014 Line of storms will affect PIA between 18z and 19z, mainly with heavy rains of 0.75" in less than an hour. BMI should also be affected between 19z and 20z with similar conditions. Visibility in the heavy rain could drop to less than a mile for a short time. A 1sm +TSRA was included in a tempo for the heavy rain potential. Ceiling heights should generally stay MVFR even during thunderstorms. CMI, SPI and DEC will have a better chance of remaining dry through the afternoon. Another complex of storms is projected to develop in N IL later this afternoon and evening and move south across our terminal sites overnight. Timing and coverage of that complex is not handled well in any of the short term models, so VCTS was included for now until closer to this evening. Rain chances will exist all night at the terminals as a frontal boundary slowly sags south into C IL. Thursday morning should see a decrease in coverage, especially after sunrise. Winds will remain southwest at 12g20kt until evening then shift south and diminish below 10kt. SSW winds will increase again to around 10kt after sunrise Thursday. Shimon && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1125 AM CDT WED JUN 18 2014 .DISCUSSION... 944 AM CDT A LINE OF SHOWERS AND STORMS IS MOVING TROUGH NORTH CENTRAL ILLINOIS THIS MORNING. ON IR SATELLITE...IN GENERAL THE SYSTEM IS WARMING ALOFT BUT ISOLATED STORMS ARE SHOWING PERIODIC STRENGTHENING. LAPSE RATES ALOFT WILL CONTINUE TO SUPPORT THUNDERSTORMS BUT IN GENERAL THINKING THE ATMOSPHERE IS TOO STABLE FOR SEVERE STORMS. MAY SEE AN ADDITIONAL STORM OR TWO PULSE UP AND PRODUCE SPECIAL WEATHER STATEMENT WORTHY GUSTS...BUT IN GENERAL EXPECTING THE LINE TO GRADUALLY DECLINE AS IT MOVES THROUGH NORTHERN IL AND NW INDIANA. WITH THE EXTENSIVE CLOUD COVER OVERHEAD...HAVE VERY LOW CONFIDENCE IN THE FORECAST FOR THIS AFTERNOON. NO GUIDANCE MEMBER HAS PICKED UP THIS MORNING/S LINE OF STORMS. IF THE CLOUDS STICK AROUND...IT WILL BE VERY DIFFICULT TO DESTABILIZE AND COULD SEE A COOLER AND DRIER DAY THAN EXPECTED. BUT IF CLOUDS THIN OUT BEHIND THE STORMS...HOT CONDITIONS AND SCATTERED STORM DEVELOPMENT IS MORE LIKELY. THE CLOUDS ARE THINNING OVER IOWA THIS MORNING SO FOR NOW DECIDED TO KEEP A CHANCE OF THUNDER GOING IN THE FORECAST. GIVEN THE STATIONARY BOUNDARY TO OUR NORTH...KEPT THE GREATEST CHANCE ALONG THE IL/WI STATE LINE. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * LINE OF TSRA MOVING THROUGH TERMINALS. * ADDITIONAL TSRA POTENTIAL LATER THIS AFTERNOON INTO THIS EVENING. * WIND TRENDS THROUGH THE REMAINDER OF THE DAY. RC //DISCUSSION...UPDATED 16Z... TSRA COMPLEX CURRENTLY MOVING THROUGH THE TERMINALS WITH DROP TO IFR/LOWER MVFR VSBY AND STRONG NORTH-NORTHWEST GUSTS APPROACHING 30 KT ON LEADING EDGE. LOW CONFIDENCE IN WIND TRENDS BEHIND THE COMPLEX...WITH SITES ACROSS NORTH CENTRAL ILLINOIS HAVING SHIFTED TO EAST-NORTHEAST. WINDS MAY EVENTUALLY TURN VARIABLE AFTER A FEW HOURS DUE TO DISRUPTION OF WIND FIELD. THE CURRENT CONVECTION ALSO THROWS DOUBT INTO HOW CONVECTION WILL EVOLVE THE REMAINDER OF THE DAY...WITH IT LIKELY TAKING LONGER FOR THE ATMOSPHERE TO DESTABILIZE AGAIN. HAVE MAINTAINED TEMPO TSRA GROUP FROM 00Z TO 04Z FOR NOW. RC FROM 12Z... ANOTHER DAY OF PRIMARILY VFR CONDITIONS ON TAP WITH A GREAT DEAL OF UNCERTAINTY SURROUNDING THUNDERSTORMS CHANCES. THIS MORNING...A FRONTAL BOUNDARY IS DRAPED NEAR THE IL/WI STATE LINES WITH OVERNIGHT CONVECTION OCCURRING NORTH OF THE FRONT. FARTHER WEST...AN AREA OF MORE ROBUST THUNDERSTORMS IS PUSHING EAST ACROSS NORTHERN IOWA THOUGH HAS SHOWN SOME SIGNS OF WEAKENING AND EXPECT THIS TREND TO CONTINUE THROUGH THE MORNING. THUNDERSTORMS ARE CURRENTLY NOT EXPECTED TO MAKE IT INTO RFD BUT REMNANT SHOWERS MAY PERSIST PUSHING THROUGH STARTING IN THE 14-15Z HOUR. MODERATE TO STRONG INSTABILITY IS ONCE AGAIN PROGGED TO DEVELOP ACROSS THE REGION TODAY AND WILL BE CAPPED EARLY IN THE DAY THOUGH THE CAP STARTS TO ERODE MID AFTERNOON. THERE IS LITTLE IN THE WAY OF UPPER LEVEL SUPPORT WITH EVEN WEAK MID LEVEL HEIGHT RISES BUILDING OVER THE AREA THIS AFTERNOON THAT MIGHT HELP SUPPRESS NEW GROWTH. CHANCES FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON ARE NOT ZERO BUT LOW ENOUGH TO PRECLUDE ANY REFERENCE IN THE TAFS. THE BEST CHANCES APPEAR TO BE LATE AFTERNOON INTO THE EVENING AS THE FRONT SAGS SOUTH INTO THE AREA...THOUGH MAY COME THROUGH QUICKER IN FAR NORTHEAST ILLINOIS AS AN ENHANCED LAKE BREEZE. WITH THE CAP FAIRLY WEAK AT THIS POINT...THIS MAY SERVE THE FOCUS FOR MORE WIDESPREAD THUNDERSTORM DEVELOPMENT. WINDS SHOULD GRADUALLY VEER BACK AROUND TO THE SOUTHEAST LATE TONIGHT INTO EARLY THURSDAY AS THE WARM FRONT LIFTS BACK TO THE NORTH. BMD //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH IN CURRENT LINE OF TSRA CLEARING ORD SHORTLY AND MDW BY 17-1730Z. * LOW CONFIDENCE IN WIND TRENDS THE REMAINDER OF THE DAY. * LOW CONFIDENCE IN TSRA TRENDS THIS AFTERNOON INTO THIS EVENING. RC //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR WITH PERIODIC CHANCES FOR THUNDERSTORMS. BMD && .MARINE... 247 AM CDT A FRONTAL BOUNDARY WILL LINGER IN THE VICINITY OF LAKE MICHIGAN THROUGH THE REMAINDER OF THE WEEK. IN GENERAL...SOUTH WINDS ARE EXPECTED SOUTH OF THE BOUNDARY WITH NORTHEAST WINDS NORTH OF THE BOUNDARY. THE FRONT IS EXPECTED TO SAG SOUTH ACROSS LAKE MICHIGAN TODAY...THEN LIFT BACK NORTH AGAIN THURSDAY INTO FRIDAY. HIGH PRESSURE WILL BUILD JUST EAST OF LAKE MICHIGAN LATE IN THE WEEK INTO THE WEEKEND AND SHOULD RESULT IN RELATIVELY MODEST WINDS ACROSS THE LAKE THIS WEEKEND INTO EARLY NEXT WEEK. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1055 AM CDT Wed Jun 18 2014 .DISCUSSION... ISSUED 1045 AM CDT Wed Jun 18 2014 A line of storms has reached Knox county and will be moving into an unstable airmass with decreasing CIN and CAPE values approaching 3000 J/kg. Expect the line to move primarily east as individual storms drift southeast. Based on HRRR 3km and NCEP 4km output, it appears the southern extent of the line as it progresses east should generally remain north of a line from Rushville to Lincoln to Champaign. We kept daytime chance PoPs confined to that general area. That line it projected to remain sub-severe for the most part during the day. Severe potential looks higher tonight as a complex of storms develops to our north along the stationary front and rides over the upper level ridge into N IL this evening. That complex is projected to curve to the ESE tonight and dissipate as it reaches Lincoln to Champaign shortly after midnight. Varying solutions high resolution models lead to lower confidence on any one solution, but that appears to be closer to the consensus at this point. Temperatures today will climb into the lower 90s in most areas. The current line of storms will produce a cold pool that will spread across the northern third of counties, but some sun later this afternoon should boost even those areas back toward the low 90s. Dewpoints will reside in the low 70s all day as well, making for very humid conditions. Heat index readings will approach 100 degrees in areas that remain sunny through the day, mainly south of Lincoln. Updates this morning were mainly to the weather and PoP grids, with minor adjustments to temps. Updated info will be available shortly. Shimon && .AVIATION... ISSUED 637 AM CDT Wed Jun 18 2014 A very challenging forecast, as convection will be dictated by various residual outflow boundaries plus a surface front across northern Illinois that may drift south a bit tonight. With the various synoptic and high-resolution models showing a wide variety of solutions, confidence on thunder elements of the TAF set is lower than usual. Have generally gone with VCTS mentions with a PROB30 group this evening to try and highlight a more likely time frame of any temporary MVFR conditions, based on the output of the ARW and NMM models. Kept KSPI/KDEC dry into early evening, but isolated showers/storms may occur earlier as well. Geelhart && .PREV DISCUSSION... ISSUED 330 AM CDT Wed Jun 18 2014 SHORT TERM...Today through Friday night Will issue another special weather statement to address the heat and humidity today and Thursday with highs around 90F and heat indices peaking from 95 to 100F similar to what we experienced yesterday. Strong upper level ridge (592 dm 500 mb high pressure over the southeast states) has been keeping much of central and southeast IL dry with the heat and humidity. MCS`s bringing more strong to severe thunderstorms with heavy rains north of IL over MN/WI and northern IA early this morning. These MCS`s forming on nose of low level jet interacting with frontal boundary draped over southern Great Lakes and upper MS river valley and extends to 999 mb low pressure in NE CO. Strong 558 dm 500 mb low was along the ID/MT border with series of MCS east of it from SD into the southern Great Lakes. Upper level low near ID/MT border to lift NE into southern Saskatchewan by sunset Thu while short waves to weaken top of upper level ridge and increase chances of convection over central IL from north to south from this afternoon through next few days as frontal boundary sags back south toward central IL by Friday. Most areas will still be dry this morning with isolated convection developing in the tropical air mass this afternoon especially northern areas. RAP and HRRR models also show some qpf in far SE IL from Lawrenceville SE this afternoon. SPC has shifted slight risk of severe storms further south tonight to included most of central IL with just southern six counties not in slight risk. Highest risk of severe storms still appears north of Peoria where 30% risk of large hail and damaging wind gusts where best bulk shear in combination with moderate to strong instability. Highest convection chances of 50-60% over northern counties from tonight through Thu night shift further south during Friday with frontal boundary. SPC keeps slight risk NW of CWA Thu afternoon & Thu night especially over IA. LONG TERM...Saturday through Tuesday night Central IL gets into a WNW upper level flow during the weekend into early next week with disturbances tracking ESE over top of ridge across the Midwest and interacting with a humid air mass to trigger daily chances of showers and thunderstorms. An upper level trof digging into the Midwest Monday afternoon and Monday night to drive a cold front SE into IL Monday night and increase chances of showers and thunderstorms then with gradually cooler air by Tue. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
638 AM CDT WED JUN 18 2014 .DISCUSSION... 543 AM CDT COMPLEX OF SHOWERS AND THUNDERSTORMS CONTINUES TO MOVE EAST- SOUTHEAST ACROSS NORTH CENTRAL AND NORTHEAST IOWA. INTENSITY HAS WANED SOMEWHAT THOUGH THERE HAS BEEN SOME NEW DEVELOPMENT AT TIMES. COLD POOL STILL SEEMS TO BE MAINTAINING ITSELF WITH OUTFLOW TURNING WINDS NORTHWESTERLY THEN EASTERLY WINDS FILLING IN BEHIND. STILL SOME QUESTION ON HOW LONG THIS WILL BE MAINTAINED BUT TRAJECTORY HAS BEEN STEADY AND TAKES THE SOUTHERN PORTION OF THE COMPLEX ACROSS THE NORTHERN TIER OR TWO OF COUNTIES BASED ON ITS CURRENT FORM...OR PRIMARILY ALONG AND NORTH OF I-88/I-290. THE COMPLEX HAS SPED UP A BUT AND ARRIVAL IN THE FAR NORTHWEST CORNER OF THE AREA LOOKS TO BE DURING THE 13Z HOUR. SOME GUSTINESS LOOKS TO ACCOMPANY THE ARRIVAL IN THE NORTHWEST BUT THE PRIMARY CONCERN WILL BE HEAVY DOWNPOURS. HAVE ADDED SOME DETAIL TO POPS THROUGH THE MORNING. EXPECT THAT AN OUTFLOW BOUNDARY WILL BE LEFT BEHIND WHEN THE COMPLEX EXITS OR DECAYS WHICH COULD END UP BEING THE FOCUS FOR NEW DEVELOPMENT LATER TODAY. WILL LEAVE TEMPS AS-IS FOR THE REST OF THE DAY BUT THEY MAY BE AFFECTED DEPENDING ON THE ABILITY TO DESTABILIZE THIS AFTERNOON. MDB //PREV DISCUSSION... 307 AM CDT CONVECTIVE CHANCES REMAIN THE FOCUS THROUGH THE FORECAST PERIOD AS THE LARGE SCALE UPPER TROUGH PARKED OVER THE WESTERN U.S. SLOWLY EVOLVES THROUGH THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY SHOWS THIS LARGE UPPER LOW SPINNING OVER IDAHO WITH RIDGING JUST TO ITS EAST ACROSS THE MID MISSISSIPPI RIVER VALLEY INTO CENTRAL CANADA. NUMEROUS WAVES CONTINUE TO TRAVERSE THE LOWER AMPLITUDE PORTION OF THE RIDGE ACROSS THE PLAINS/MID AND UPPER MISSISSIPPI RIVER VALLEY SERVING TO FOCUS AREAS OF CONVECTION. ALSO OF NOTE IS A TROUGH THAT IS MOVING SOUTHWARD ACROSS ONTARIO AND QUEBEC. AT THE SURFACE...LOW PRESSURE IS IS PARKED OVER EASTERN COLORADO WITH A WARM FRONTAL BOUNDARY STRETCHING EASTWARD ACROSS SOUTHERN MINNESOTA AND CENTRAL WISCONSIN. IT THEN ARCS DOWN LAKE MICHIGAN AND EASTWARD TO ANOTHER SURFACE LOW OVER NORTHERN NEW YORK. TODAY AND TONIGHT...ANOTHER TOUGH FORECAST FOR TODAY WITH ONGOING CONVECTION AFFECTING HOW THINGS EVOLVE THROUGH THE DAY/EVENING. WARM FRONTAL BOUNDARY HAS LIFTED NORTH OF THE CWA EARLY THIS MORNING WITH MAIN CORRIDOR OF CONVECTION ALONG AND NORTH OF THE FRONT. THUNDERSTORM COMPLEX OVER NORTH CENTRAL IOWA HAS BECOME BETTER ORGANIZED AND HAS ACCELERATED EASTWARD. THE LOW LEVEL JET IS FOCUSED INTO NORTH CENTRAL IOWA BUT MOIST LOW/MID LEVEL FLOW TURNS MORE SOUTHWESTERLY TO THE EAST. 850-300 MB THICKNESS FIELDS DO SHOW A SOUTHEASTERLY COMPONENT WITH THE INSTABILITY GRADIENT ALSO ORIENTED A BIT NW-SE. PROGRESSION OF THIS COMPLEX WILL NEED TO BE WATCHED THE NEXT FEW HOURS AS A TURN TO THE SOUTHEAST IS SUGGESTED BY THE ABOVE ALONG WITH A TURNING OF FORWARD PROPAGATING CORFIDI VECTORS AFTER DAYBREAK. SHOULD THIS COMPLEX MAINTAIN ITSELF AND TURN MORE SOUTHEASTERLY THEN AT LEAST NORTHERN AREAS OF THE CWA WILL BE AFFECTED DURING THE MID/LATE MORNING HOURS. WOULD EXPECT THAT THE COMPLEX WOULD BE IN A DECAYING STATE AT THAT TIME BUT A STRONG COLD POOL SEEMS TO BE DEVELOPING AND UNSTABLE AIR WILL BE IN PLACE LOCALLY SO MAINTENANCE IS POSSIBLE. WILL GO AHEAD AND INDICATE HIGHER CHANCE POPS FOR THE NORTHERN THIRD TO HALF OF THE AREA LATE MORNING INTO MIDDAY BUT THESE WILL NEED TO BE TWEAKED BASED ON EVOLUTION OF THE COMPLEX THROUGH DAYBREAK. LOOKING TOWARDS THE AFTERNOON...WITH CONVECTION AFFECTING MUCH OF THE NEAR TERM GUIDANCE WILL CONTINUE TO APPROACH THE FORECAST FROM A LARGER SCALE PERSPECTIVE. THE UPPER TROUGH MOVING SOUTHWARD ACROSS CENTRAL ONTARIO LOOKS TO BECOME A KEY PLAYER IN OUR CONVECTIVE CHANCES LATER TODAY AND TONIGHT AS IT WILL BE DROPPING ACROSS THE LOWER GREAT LAKES WITH A STRONG SURFACE HIGH SPREADING SOUTHWARD AS WELL. THIS WILL PUSH THE STATIONARY BOUNDARY SOUTHWARD TO THE EAST WHILE THE UPPER TROUGH TO THE WEST PROGRESSES NORTHEAST ACROSS MONTANA PUSHING SOMEWHAT DISORGANIZED SURFACE LOW PRESSURE NORTHWARD. THIS WILL CAUSE THE BOUNDARY TO BECOME ORIENTED FROM NW TO SE INTO THE EVENING. THE SHIFTING OF THESE TROUGHS WILL ALLOW FOR THE UPPER RIDGE TO SHARPEN OVER THE MID-UPPER MISSISSIPPI RIVER VALLEY BUT IT IS WEAKER CLOSER TO THE LOCAL AREA SO SHORTWAVES MAY CONTINUE TO EMANATE THROUGH IT. WITH THE FRONTAL ZONE RE-ORIENTING THE LOCAL AREA LOOKS TO BE MORE SQUARELY PLACED WITHIN IT SUGGESTING THAT OUR CONVECTIVE CHANCES WILL INCREASE. MORNING CONVECTION WILL LIKELY DETERMINE HOW THINGS PLAY OUT THIS AFTERNOON AND PROBABLY LOWER EARLY AFTERNOON CHANCES ASSUMING THINGS STABILIZE FROM OUTFLOW OF THE COMPLEX TO THE NORTH OF IN THE WAKE OF CONVECTION CROSSING THE CWA...BUT THIS REMAINS TO BE SEEN. SEE BETTER LARGER SCALE POTENTIAL THIS EVENING AND OVERNIGHT AS THE FRONT SHIFTS SO WILL CARRY HIGHEST POPS DURING THAT TIME. IF CONVECTION STAYS NORTH THEN THERE SHOULD BE NO PROBLEM HAVING HIGH TEMPS REACH THE UPPER 80S AND LOWER 90S THIS AFTERNOON. MORNING/MIDDAY CONVECTION WOULD LIKELY RESULT IN LOWER TEMPS...THOUGH A LATE DAY RALLY IS POSSIBLE. LAKE BREEZE PROCESSES MAY COMBINE WITH THE SHIFTING FRONT TO BRING NORTHEAST WINDS TO LAKESHORE AREAS LATE THIS AFTERNOON BUT THIS MAY BE AFFECTED BY MORNING CONVECTION AS WELL. WILL HAVE EARLY HIGHS ALONG THE LAKE WITH A COOLING TREND DURING THE AFTERNOON. THURSDAY AND FRIDAY...THE UPPER LOW WILL MEANDER NORTH AND EAST INTO SOUTHERN ALBERTA WHILE THE UPPER TROUGH THAT IS OVER ONTARIO THIS MORNING CONTINUES SOUTHWARD INTO NEW ENGLAND. SURFACE HIGH PRESSURE WILL BE SETTLING INTO EASTERN ONTARIO AND WESTERN QUEBEC. POTENTIAL ONGOING CONVECTION WILL BE A DRIVER OF THINGS BUT SYNOPTICALLY SPEAKING THE WARM FRONT SHOULD BE ORIENTED MORE NORTHWEST TO SOUTHEAST. CONVECTIVE CHANCES WILL CONTINUE WITH THE BOUNDARY LIKELY TO BE IN THE AREA AS WELL AS A LIKELIHOOD OF WEAK UPPER IMPULSES TO MOVE THROUGH THE RIDGED FLOW OVERHEAD. WARM AND HUMID CONDITIONS WILL PERSIST SO ASSUMING CONVECTION IS NOT LIMITING TEMPS...UPPER 80S ARE EXPECTED...THOUGH A SOUTHEASTERLY WIND WILL COOL THE ILLINOIS LAKESHORE AREAS. BY FRIDAY...THE UPPER LOW WILL START TO MOVE TO THE EAST WITH A COOL FRONTAL BOUNDARY NOW STRETCHING SOUTHWARD FROM THE ASSOCIATED SURFACE LOW OVER THE FAR NORTHERN PLAINS/SOUTHERN CANADIAN PRAIRIES. THIS FRONT WILL PUSH EAST ACROSS THE AREA FRIDAY PERHAPS BRINGING A BETTER FOCUS FOR STORMS...THOUGH IT MAY CROSS EARLY IN THE DAY LIMITING THE POTENTIAL FOR NEW DEVELOPMENT. NOT EXPECTING MUCH CHANGE IN TEMPS/HUMIDITY BEHIND THE FRONT SO MID AND UPPER 80S WILL PROBABLY CONTINUE. SATURDAY AND BEYOND...THE UPPER LOW WILL DE-AMPLIFY OVER SOUTHERN MANITOBA INTO SATURDAY. THIS WILL LEAD TO A MORE ZONAL FLOW ACROSS MUCH OF THE CONUS. THIS WILL BE SUPPORTIVE OF WEAK SHORTWAVES MOVING THROUGH THE FLOW WHICH WILL LEAD TO MORE CHANCES FOR CONVECTION SATURDAY AND SUNDAY. ANOTHER UPPER TROUGH WILL MOVE SOUTHWARD INTO EASTERN CANADA LATER SUNDAY WHICH GUIDANCE CONTINUES TO PHASE WITH THE WEAKENED UPPER TROUGH ACROSS SOUTHERN CANADA. THE DEGREE OF PHASING CONTINUES TO VARY AMONG RUNS WHICH IS NOT SURPRISING GIVEN THE TIME RANGE AND WHAT NEEDS TO OCCUR PRIOR TO THAT TIME. WITH THIS TROUGH PASSING OVER OR TO THE NORTHEAST OF THE AREA MID LEVEL TEMPS WILL COOL EARLY NEXT WEEK...WITH COOLER AIR AND REDUCED HUMIDITY THANKS TO A NORTHEASTERLY LOW LEVEL FLOW. MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * PERIODIC CHANCES FOR THUNDERSTORMS DURING THE TAF PERIOD. * SSW WINDS TODAY TURNING TO THE NORTHEAST THIS AFTERNOON/EVENING. BMD //DISCUSSION...UPDATED 12Z... ANOTHER DAY OF PRIMARILY VFR CONDITIONS ON TAP WITH A GREAT DEAL OF UNCERTAINTY SURROUNDING THUNDERSTORMS CHANCES. THIS MORNING...A FRONTAL BOUNDARY IS DRAPED NEAR THE IL/WI STATE LINES WITH OVERNIGHT CONVECTION OCCURRING NORTH OF THE FRONT. FARTHER WEST...AN AREA OF MORE ROBUST THUNDERSTORMS IS PUSHING EAST ACROSS NORTHERN IOWA THOUGH HAS SHOWN SOME SIGNS OF WEAKENING AND EXPECT THIS TREND TO CONTINUE THROUGH THE MORNING. THUNDERSTORMS ARE CURRENTLY NOT EXPECTED TO MAKE IT INTO RFD BUT REMNANT SHOWERS MAY PERSIST PUSHING THROUGH STARTING IN THE 14-15Z HOUR. MODERATE TO STRONG INSTABILITY IS ONCE AGAIN PROGGED TO DEVELOP ACROSS THE REGION TODAY AND WILL BE CAPPED EARLY IN THE DAY THOUGH THE CAP STARTS TO ERODE MID AFTERNOON. THERE IS LITTLE IN THE WAY OF UPPER LEVEL SUPPORT WITH EVEN WEAK MID LEVEL HEIGHT RISES BUILDING OVER THE AREA THIS AFTERNOON THAT MIGHT HELP SUPPRESS NEW GROWTH. CHANCES FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON ARE NOT ZERO BUT LOW ENOUGH TO PRECLUDE ANY REFERENCE IN THE TAFS. THE BEST CHANCES APPEAR TO BE LATE AFTERNOON INTO THE EVENING AS THE FRONT SAGS SOUTH INTO THE AREA...THOUGH MAY COME THROUGH QUICKER IN FAR NORTHEAST ILLINOIS AS AN ENHANCED LAKE BREEZE. WITH THE CAP FAIRLY WEAK AT THIS POINT...THIS MAY SERVE THE FOCUS FOR MORE WIDESPREAD THUNDERSTORM DEVELOPMENT. WINDS SHOULD GRADUALLY VEER BACK AROUND TO THE SOUTHEAST LATE TONIGHT INTO EARLY THURSDAY AS THE WARM FRONT LIFTS BACK TO THE NORTH. BMD //ORD AND MDW CONFIDENCE...UPDATED 12Z... * LOW CONFIDENCE IN TSRA THIS MORNING OR AFTERNOON...LOW-MEDIUM CONFIDENCE THIS EVENING/TONIGHT. * MEDIUM CONFIDENCE IN WIND SHIFT TO NE AND TIMING WITHIN AN HOUR OR TWO. * HIGH CONFIDENCE IN PREVAILING VFR CONDITIONS OUTSIDE INFLUENCE OF TSRA. BMD //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR WITH PERIODIC CHANCES FOR THUNDERSTORMS. BMD && .MARINE... 247 AM CDT A FRONTAL BOUNDARY WILL LINGER IN THE VICINITY OF LAKE MICHIGAN THROUGH THE REMAINDER OF THE WEEK. IN GENERAL...SOUTH WINDS ARE EXPECTED SOUTH OF THE BOUNDARY WITH NORTHEAST WINDS NORTH OF THE BOUNDARY. THE FRONT IS EXPECTED TO SAG SOUTH ACROSS LAKE MICHIGAN TODAY...THEN LIFT BACK NORTH AGAIN THURSDAY INTO FRIDAY. HIGH PRESSURE WILL BUILD JUST EAST OF LAKE MICHIGAN LATE IN THE WEEK INTO THE WEEKEND AND SHOULD RESULT IN RELATIVELY MODEST WINDS ACROSS THE LAKE THIS WEEKEND INTO EARLY NEXT WEEK. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 638 AM CDT Wed Jun 18 2014 .DISCUSSION... ISSUED 330 AM CDT Wed Jun 18 2014 SHORT TERM...Today through Friday night Will issue another special weather statement to address the heat and humidity today and Thursday with highs around 90F and heat indices peaking from 95 to 100F similar to what we experienced yesterday. Strong upper level ridge (592 dm 500 mb high pressure over the southeast states) has been keeping much of central and southeast IL dry with the heat and humidity. MCS`s bringing more strong to severe thunderstorms with heavy rains north of IL over MN/WI and northern IA early this morning. These MCS`s forming on nose of low level jet interacting with frontal boundary draped over southern Great Lakes and upper MS river valley and extends to 999 mb low pressure in NE CO. Strong 558 dm 500 mb low was along the ID/MT border with series of MCS east of it from SD into the southern Great Lakes. Upper level low near ID/MT border to lift NE into southern Saskatchewan by sunset Thu while short waves to weaken top of upper level ridge and increase chances of convection over central IL from north to south from this afternoon through next few days as frontal boundary sags back south toward central IL by Friday. Most areas will still be dry this morning with isolated convection developing in the tropical air mass this afternoon especially northern areas. RAP and HRRR models also show some qpf in far SE IL from Lawrenceville SE this afternoon. SPC has shifted slight risk of severe storms further south tonight to included most of central IL with just southern six counties not in slight risk. Highest risk of severe storms still appears north of Peoria where 30% risk of large hail and damaging wind gusts where best bulk shear in combination with moderate to strong instability. Highest convection chances of 50-60% over northern counties from tonight through Thu night shift further south during Friday with frontal boundary. SPC keeps slight risk NW of CWA Thu afternoon & Thu night especially over IA. LONG TERM...Saturday through Tuesday night Central IL gets into a WNW upper level flow during the weekend into early next week with disturbances tracking ESE over top of ridge across the Midwest and interacting with a humid air mass to trigger daily chances of showers and thunderstorms. An upper level trof digging into the Midwest Monday afternoon and Monday night to drive a cold front SE into IL Monday night and increase chances of showers and thunderstorms then with gradually cooler air by Tue. 07 && .AVIATION... ISSUED 637 AM CDT Wed Jun 18 2014 A very challenging forecast, as convection will be dictated by various residual outflow boundaries plus a surface front across northern Illinois that may drift south a bit tonight. With the various synoptic and high-resolution models showing a wide variety of solutions, confidence on thunder elements of the TAF set is lower than usual. Have generally gone with VCTS mentions with a PROB30 group this evening to try and highlight a more likely time frame of any temporary MVFR conditions, based on the output of the ARW and NMM models. Kept KSPI/KDEC dry into early evening, but isolated showers/storms may occur earlier as well. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
404 AM CDT WED JUN 18 2014 .DISCUSSION... 307 AM CDT CONVECTIVE CHANCES REMAIN THE FOCUS THROUGH THE FORECAST PERIOD AS THE LARGE SCALE UPPER TROUGH PARKED OVER THE WESTERN U.S. SLOWLY EVOLVES THROUGH THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY SHOWS THIS LARGE UPPER LOW SPINNING OVER IDAHO WITH RIDGING JUST TO ITS EAST ACROSS THE MID MISSISSIPPI RIVER VALLEY INTO CENTRAL CANADA. NUMEROUS WAVES CONTINUE TO TRAVERSE THE LOWER AMPLITUDE PORTION OF THE RIDGE ACROSS THE PLAINS/MID AND UPPER MISSISSIPPI RIVER VALLEY SERVING TO FOCUS AREAS OF CONVECTION. ALSO OF NOTE IS A TROUGH THAT IS MOVING SOUTHWARD ACROSS ONTARIO AND QUEBEC. AT THE SURFACE...LOW PRESSURE IS IS PARKED OVER EASTERN COLORADO WITH A WARM FRONTAL BOUNDARY STRETCHING EASTWARD ACROSS SOUTHERN MINNESOTA AND CENTRAL WISCONSIN. IT THEN ARCS DOWN LAKE MICHIGAN AND EASTWARD TO ANOTHER SURFACE LOW OVER NORTHERN NEW YORK. TODAY AND TONIGHT...ANOTHER TOUGH FORECAST FOR TODAY WITH ONGOING CONVECTION AFFECTING HOW THINGS EVOLVE THROUGH THE DAY/EVENING. WARM FRONTAL BOUNDARY HAS LIFTED NORTH OF THE CWA EARLY THIS MORNING WITH MAIN CORRIDOR OF CONVECTION ALONG AND NORTH OF THE FRONT. THUNDERSTORM COMPLEX OVER NORTH CENTRAL IOWA HAS BECOME BETTER ORGANIZED AND HAS ACCELERATED EASTWARD. THE LOW LEVEL JET IS FOCUSED INTO NORTH CENTRAL IOWA BUT MOIST LOW/MID LEVEL FLOW TURNS MORE SOUTHWESTERLY TO THE EAST. 850-300 MB THICKNESS FIELDS DO SHOW A SOUTHEASTERLY COMPONENT WITH THE INSTABILITY GRADIENT ALSO ORIENTED A BIT NW-SE. PROGRESSION OF THIS COMPLEX WILL NEED TO BE WATCHED THE NEXT FEW HOURS AS A TURN TO THE SOUTHEAST IS SUGGESTED BY THE ABOVE ALONG WITH A TURNING OF FORWARD PROPAGATING CORFIDI VECTORS AFTER DAYBREAK. SHOULD THIS COMPLEX MAINTAIN ITSELF AND TURN MORE SOUTHEASTERLY THEN AT LEAST NORTHERN AREAS OF THE CWA WILL BE AFFECTED DURING THE MID/LATE MORNING HOURS. WOULD EXPECT THAT THE COMPLEX WOULD BE IN A DECAYING STATE AT THAT TIME BUT A STRONG COLD POOL SEEMS TO BE DEVELOPING AND UNSTABLE AIR WILL BE IN PLACE LOCALLY SO MAINTENANCE IS POSSIBLE. WILL GO AHEAD AND INDICATE HIGHER CHANCE POPS FOR THE NORTHERN THIRD TO HALF OF THE AREA LATE MORNING INTO MIDDAY BUT THESE WILL NEED TO BE TWEAKED BASED ON EVOLUTION OF THE COMPLEX THROUGH DAYBREAK. LOOKING TOWARDS THE AFTERNOON...WITH CONVECTION AFFECTING MUCH OF THE NEAR TERM GUIDANCE WILL CONTINUE TO APPROACH THE FORECAST FROM A LARGER SCALE PERSPECTIVE. THE UPPER TROUGH MOVING SOUTHWARD ACROSS CENTRAL ONTARIO LOOKS TO BECOME A KEY PLAYER IN OUR CONVECTIVE CHANCES LATER TODAY AND TONIGHT AS IT WILL BE DROPPING ACROSS THE LOWER GREAT LAKES WITH A STRONG SURFACE HIGH SPREADING SOUTHWARD AS WELL. THIS WILL PUSH THE STATIONARY BOUNDARY SOUTHWARD TO THE EAST WHILE THE UPPER TROUGH TO THE WEST PROGRESSES NORTHEAST ACROSS MONTANA PUSHING SOMEWHAT DISORGANIZED SURFACE LOW PRESSURE NORTHWARD. THIS WILL CAUSE THE BOUNDARY TO BECOME ORIENTED FROM NW TO SE INTO THE EVENING. THE SHIFTING OF THESE TROUGHS WILL ALLOW FOR THE UPPER RIDGE TO SHARPEN OVER THE MID-UPPER MISSISSIPPI RIVER VALLEY BUT IT IS WEAKER CLOSER TO THE LOCAL AREA SO SHORTWAVES MAY CONTINUE TO EMANATE THROUGH IT. WITH THE FRONTAL ZONE RE-ORIENTING THE LOCAL AREA LOOKS TO BE MORE SQUARELY PLACED WITHIN IT SUGGESTING THAT OUR CONVECTIVE CHANCES WILL INCREASE. MORNING CONVECTION WILL LIKELY DETERMINE HOW THINGS PLAY OUT THIS AFTERNOON AND PROBABLY LOWER EARLY AFTERNOON CHANCES ASSUMING THINGS STABILIZE FROM OUTFLOW OF THE COMPLEX TO THE NORTH OF IN THE WAKE OF CONVECTION CROSSING THE CWA...BUT THIS REMAINS TO BE SEEN. SEE BETTER LARGER SCALE POTENTIAL THIS EVENING AND OVERNIGHT AS THE FRONT SHIFTS SO WILL CARRY HIGHEST POPS DURING THAT TIME. IF CONVECTION STAYS NORTH THEN THERE SHOULD BE NO PROBLEM HAVING HIGH TEMPS REACH THE UPPER 80S AND LOWER 90S THIS AFTERNOON. MORNING/MIDDAY CONVECTION WOULD LIKELY RESULT IN LOWER TEMPS...THOUGH A LATE DAY RALLY IS POSSIBLE. LAKE BREEZE PROCESSES MAY COMBINE WITH THE SHIFTING FRONT TO BRING NORTHEAST WINDS TO LAKESHORE AREAS LATE THIS AFTERNOON BUT THIS MAY BE AFFECTED BY MORNING CONVECTION AS WELL. WILL HAVE EARLY HIGHS ALONG THE LAKE WITH A COOLING TREND DURING THE AFTERNOON. THURSDAY AND FRIDAY...THE UPPER LOW WILL MEANDER NORTH AND EAST INTO SOUTHERN ALBERTA WHILE THE UPPER TROUGH THAT IS OVER ONTARIO THIS MORNING CONTINUES SOUTHWARD INTO NEW ENGLAND. SURFACE HIGH PRESSURE WILL BE SETTLING INTO EASTERN ONTARIO AND WESTERN QUEBEC. POTENTIAL ONGOING CONVECTION WILL BE A DRIVER OF THINGS BUT SYNOPTICALLY SPEAKING THE WARM FRONT SHOULD BE ORIENTED MORE NORTHWEST TO SOUTHEAST. CONVECTIVE CHANCES WILL CONTINUE WITH THE BOUNDARY LIKELY TO BE IN THE AREA AS WELL AS A LIKELIHOOD OF WEAK UPPER IMPULSES TO MOVE THROUGH THE RIDGED FLOW OVERHEAD. WARM AND HUMID CONDITIONS WILL PERSIST SO ASSUMING CONVECTION IS NOT LIMITING TEMPS...UPPER 80S ARE EXPECTED...THOUGH A SOUTHEASTERLY WIND WILL COOL THE ILLINOIS LAKESHORE AREAS. BY FRIDAY...THE UPPER LOW WILL START TO MOVE TO THE EAST WITH A COOL FRONTAL BOUNDARY NOW STRETCHING SOUTHWARD FROM THE ASSOCIATED SURFACE LOW OVER THE FAR NORTHERN PLAINS/SOUTHERN CANADIAN PRAIRIES. THIS FRONT WILL PUSH EAST ACROSS THE AREA FRIDAY PERHAPS BRINGING A BETTER FOCUS FOR STORMS...THOUGH IT MAY CROSS EARLY IN THE DAY LIMITING THE POTENTIAL FOR NEW DEVELOPMENT. NOT EXPECTING MUCH CHANGE IN TEMPS/HUMIDITY BEHIND THE FRONT SO MID AND UPPER 80S WILL PROBABLY CONTINUE. SATURDAY AND BEYOND...THE UPPER LOW WILL DE-AMPLIFY OVER SOUTHERN MANITOBA INTO SATURDAY. THIS WILL LEAD TO A MORE ZONAL FLOW ACROSS MUCH OF THE CONUS. THIS WILL BE SUPPORTIVE OF WEAK SHORTWAVES MOVING THROUGH THE FLOW WHICH WILL LEAD TO MORE CHANCES FOR CONVECTION SATURDAY AND SUNDAY. ANOTHER UPPER TROUGH WILL MOVE SOUTHWARD INTO EASTERN CANADA LATER SUNDAY WHICH GUIDANCE CONTINUES TO PHASE WITH THE WEAKENED UPPER TROUGH ACROSS SOUTHERN CANADA. THE DEGREE OF PHASING CONTINUES TO VARY AMONG RUNS WHICH IS NOT SURPRISING GIVEN THE TIME RANGE AND WHAT NEEDS TO OCCUR PRIOR TO THAT TIME. WITH THIS TROUGH PASSING OVER OR TO THE NORTHEAST OF THE AREA MID LEVEL TEMPS WILL COOL EARLY NEXT WEEK...WITH COOLER AIR AND REDUCED HUMIDITY THANKS TO A NORTHEASTERLY LOW LEVEL FLOW. MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * PERIODIC CHANCES FOR THUNDERSTORMS THROUGH THE TAF PERIOD...BEST CHANCES SEEM TO BE WED MORNING...AND AGAIN MID/LATE WED AFTERNOON. BMD //DISCUSSION...UPDATED 06Z... A WARM FRONT LIES SOMEWHERE ACROSS CENTRAL WISCONSIN AND EXTENDS WEST ALONG THE IA/MN STATELINE. CONVECTION IS INCREASING IN COVERAGE ACROSS THE MID MISSOURI VALLEY AS LOW LEVEL JET RAMPS UP. WHILE THERE IS STRONG INSTABILITY IN PLACE LOCALLY...THERE IS STILL A CAP IN PLACE ACROSS ALL BUT FAR NORTHERN ILLINOIS WHERE A COUPLE THUNDERSTORMS HAVE DEVELOPED. OPTED TO REMOVE THUNDERSTORMS FOR THE OVERNIGHT HOURS AS IT SEEMS UNLIKELY THAT THE CONVECTION OVER IL/WI STATE LINE WILL INCREASE IN COVERAGE. THE AREA OVER IA/MN THOUGH MAY GROW UPSTREAM INTO A LINEAR COMPLEX AND WORK TOWARDS THE NORTHERN IL TERMINALS WEDNESDAY MORNING. CERTAINTY IN THIS HAPPENING IS LESS THAN 50% SO WILL NOT INCLUDE IN TAF AND WILL MONITOR TRENDS UPSTREAM OVERNIGHT. HOW CONVECTION WILL EVOLVE TOMORROW ALSO REMAINS UNCERTAIN. MODELS DO SUGGEST THAT THE CAP WILL ERODE MID AFTERNOON WITH THUNDERSTORMS POSSIBLE. WHERE EXACTLY WILL DEPEND ON HOW TONIGHT EVOLVES AND WHERE BOUNDARIES SET UP. WILL MAINTAIN A PROB30 FOR TSRA TOMORROW AFTERNOON FOR NOW. OUTSIDE OF THE INFLUENCE OF THUNDERSTORMS...VFR CONDITIONS AND SSW WINDS WILL PREVAIL UNTIL THE FRONT SAGS BACK SOUTH ACROSS THE AREA WEDNESDAY EVENING/NIGHT TURNING WINDS TO A MORE EASTERLY DIRECTION. BMD //ORD AND MDW CONFIDENCE...UPDATED 09Z... * LOW CONFIDENCE IN TSRA TIMING/PLACEMENT. * HIGH CONFIDENCE IN VFR CONDITIONS OUTSIDE OF THE INFLUENCE OF TSRA. BMD //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... THURSDAY THROUGH MONDAY...GENERALLY VFR CONDITIONS WITH PERIODIC CHANCES FOR THUNDERSTORMS. KREIN && .MARINE... 247 AM CDT A FRONTAL BOUNDARY WILL LINGER IN THE VICINITY OF LAKE MICHIGAN THROUGH THE REMAINDER OF THE WEEK. IN GENERAL...SOUTH WINDS ARE EXPECTED SOUTH OF THE BOUNDARY WITH NORTHEAST WINDS NORTH OF THE BOUNDARY. THE FRONT IS EXPECTED TO SAG SOUTH ACROSS LAKE MICHIGAN TODAY...THEN LIFT BACK NORTH AGAIN THURSDAY INTO FRIDAY. HIGH PRESSURE WILL BUILD JUST EAST OF LAKE MICHIGAN LATE IN THE WEEK INTO THE WEEKEND AND SHOULD RESULT IN RELATIVELY MODEST WINDS ACROSS THE LAKE THIS WEEKEND INTO EARLY NEXT WEEK. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 331 AM CDT Wed Jun 18 2014 .DISCUSSION... ISSUED 330 AM CDT Wed Jun 18 2014 SHORT TERM...Today through Friday night Will issue another special weather statement to address the heat and humidity today and Thursday with highs around 90F and heat indices peaking from 95 to 100F similar to what we experienced yesterday. Strong upper level ridge (592 dm 500 mb high pressure over the southeast states) has been keeping much of central and southeast IL dry with the heat and humidity. MCS`s bringing more strong to severe thunderstorms with heavy rains north of IL over MN/WI and northern IA early this morning. These MCS`s forming on nose of low level jet interacting with frontal boundary drapped over southern great lakes and upper MS river valley and extends to 999 mb low pressure in NE CO. Strong 558 dm 500 mb low was along the ID/MT border with series of MCS east of it from SD into the southern great lakes. Upper level low near ID/MT border to lift ne into southern Sasketchewan by sunset Thu while short waves to weaken top of upper level ridge and increase chances of convection over central IL from north to south from this afternoon through next few days as frontal boundary sags back south toward central IL by Friday. Most areas will still be dry this morning with isolated convection developing in the tropical air mass this afternoon especially northern areas. RAP and HRRR models also show some qpf in far se IL from Lawrenceville se this afternoon. SPC has shifted slight risk of severe storms further south tonight to included most of central IL with just southern six counties not in slight risk. Highest risk of severe storms still appears north of Peoria where 30% risk of large hail and damaging wind gusts where best bulk shear in combination with moderate to strong instability. Highest convection chances of 50-60% over northern counties from tonight through Thu night shift further south during Friday with frontal boundary. SPC keeps slight risk nw of CWA Thu afternoon & Thu night especially over IA. LONG TERM...Saturday through Tuesday night Central IL gets into a wnw upper level flow during the weekend into early next week with disturbances tracking ese over top of ridge across the Midwest and interacting with a humid air mass to trigger daily chances of showers and thunderstorms. An upper level trof digging into the Midwest Monday afternoon and Monday night to drive a cold front se into IL Monday night and increase chances of showers and thunderstorms then with gradually cooler air by Tue. 07 && .AVIATION... ISSUED 1136 PM CDT Tue Jun 17 2014 VFR throughout, keeping some high clouds in the east this evening. Cu trend continues tomorrow, developing midday and SW winds 10-12kts, gusting to 20-25kts. Early morning convection across the nrn tier of the state progged to dip down into ILX, affecting the nrn terminals in the morning. Solutions are beginning to diverge even more, with more scattered activity. With coverage and timing all over the place, keeping the mention to VCTS tomorrow afternoon. LLWS is something to keep an eye on...from a speed shear perspective... but GFS, NAM, as well as the RAPP/RUC keeps winds under 35kts in the lowest 2kft. HJS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
141 PM EDT WED JUN 18 2014 .SYNOPSIS... ISSUED AT 422 AM EDT WED JUN 18 2014 PERIODS OF SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH THE NEXT SEVERAL DAYS AS A WEAK FRONTAL BOUNDARY SETS UP OVER THE SOUTHERN GREAT LAKES. THUNDERSTORMS ARE BEING AIDED BY VERY WARM AND HUMID AIRMASS CURRENTLY IN PLACE ACROSS THE REGION. HIGHS TODAY WILL BE IN THE UPPER 80S TO LOWER 90S WITH OVERNIGHT LOWS AROUND 70. && .UPDATE... ISSUED AT 1010 AM EDT WED JUN 18 2014 INTERESTING BUT COMPLICATED NR TERM THIS MORNING AS POTENT UPSTREAM MCV PIVOTS OUT OF SE MN. ATTENDANT BKN LINE OF CONVN FM SRN WI SWWD INTO ERN SHOWING SIGNS NOW OF FWD PROPAGATION INTO RAPIDLY GROWING INSTABILITY AXIS POSITIONED W-E ACRS THE SRN LAKES INVOF DECAYING CIRRUS SHIELD...AND NO DOUBT AUGMENTED W/POTENT 50KT MID LVL SPEED MAX. HWVR COMPLICATING FCTR IS OUTFLW BNDRY EXTENDING FM FAR NE IL ESE INTO NW OH THAT MAY WITH TIME INITIATE ADDNL CONVN AHD OF THE BOWING LINE MVG OUT OF SE WI. AT EITHER RATE IT WOULD APPEAR A MORE CONSIDERABLE RISK FOR SEVERE STORMS IS SHAPING UP FOR THIS AFTN. ZONE UPDATES WILL BE FORTHCOMING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 422 AM EDT WED JUN 18 2014 ACTIVE WEATHER PATTERN CONTINUES FOR THE SOUTHERN GREAT LAKES AS SEVERAL CONVECTIVELY ENHANCED SHORTWAVES EJECT OUT OF WESTERN CONUS UPPER LOW AND TRAVEL ALONG QUASI-STATIONARY E-W FRONTAL BOUNDARY DRAPED THROUGH THE REGION. STRONG LLJ AHEAD OF THE MAIN TROUGH IS STILL MAINTAINING A CONTINUAL FEED OF VERY HIGH THETA-E AIR INTO THE MIDWEST AND OHIO VALLEY...SUPPORTING UNSTABLE CONDITIONS. SIMILAR TO THE PREVIOUS NIGHT...CONVECTION HAS FIRED UPSTREAM ON THE NOSE OF THE LLJ/MOISTURE CONVERGENCE AND HAS SLOWLY DRIFTED EASTWARD. THE DIFFERENCE IS THAT STORM CLUSTERS HAVE BEEN A LITTLE MORE DISCREET AND DISORGANIZED THUS FAR. UPSCALE GROWTH/ORGANIZATION LIKELY INHIBITED BY VERY STRONG CAPPING INVERSION NOTED ON 00Z KILX AND KDVN SOUNDINGS AS WELL AS A LACK OF ANY CLEAR SYNOPTIC SCALE SHORTWAVE/LINEAR FORCING. STORM CLUSTERS TO OUR NORTH AND NORTHWEST HAVE GRADUALLY FILLED IN/CONGLOMERATED DURING THE PAST FEW HOURS THOUGH...THANKS TO NOCTURNAL STRENGTHENING OF LLJ AND ASSOCIATED INCREASE IN LOW LEVEL MOISTURE AVAILABLE UPSTREAM. QUESTION IS HOW WILL THIS ACTIVITY EVOLVE THROUGH THE MORNING AND INTO THE AFTERNOON. LATEST SURFACE OBS ACTUALLY SHOW A FAIRLY PRONOUNCED TEMP AND MOISTURE GRADIENT JUST NORTH OF OUR CWA. ISENTROPIC ASCENT ALONG AND NORTH OF THIS SURFACE BOUNDARY IS DRIVING MUCH OF THE CURRENT CONVECTION WHILE ATMOSPHERE REMAINS CAPPED TO THE SOUTH. NOTHING TO FORCE THIS FRONT SOUTHWARD THROUGH THE MORNING WITH CONTINUAL SOUTHWEST FLOW/WAA AND NO ORGANIZED COLD POOLS/OUTFLOW BOUNDARIES AS OF YET. THEREFORE EXPECT OUR CWA WILL REMAIN LARGELY DRY DURING THIS PERIOD. SITUATION MAY CHANGE BY THE AFTERNOON AND EVENING. 00Z MODELS SUGGEST THAT A SUBTLE WAVE ASSOCIATED WITH CONVECTION CURRENTLY OVER FAR NW IA AND SOUTHERN MN WILL PUSH ESE BY LATER TODAY. SIMULTANEOUS SOUTHWARD PUSH OF CANADIAN ANTICYCLONE MAY FORCE THE FRONTAL BOUNDARY SOUTHWARD A BIT...WITH THE HELP OF COLD LAKES AND OUTFLOW FROM MORNING THUNDERSTORMS. MODELS INDICATE THIS WILL LIKELY BE ENOUGH TO WEAKEN THE STRONG CAP IN PLACE ACROSS OUR CWA AND ALLOW STORMS TO DEVELOP AND/OR PROPAGATE INTO OUR AREA BY THE AFTERNOON AND EVENING. LATEST HRRR AND HI-RES WRF-NMM ARE GENERALLY IN LINE WITH THIS IDEA. IF THE CAP DOES BREAK AS EXPECTED THEN SEVERE WEATHER WILL BE QUITE POSSIBLE. MODIFIED FORECAST SOUNDINGS INDICATE AROUND 3000 J/KG OF SBCAPE ACROSS THE AREA BY THE AFTERNOON. 0-6KM BULK SHEAR IS NOT AS HIGH SOUTH OF I-80 BUT SUFFICIENT FOR ORGANIZED LINE SEGMENTS/BOWS GIVEN LARGELY UNIDIRECTIONAL WIND FIELDS. LARGE HAIL AND STRONG WINDS WOULD BE THE PRIMARY THREATS WITH ANY STORMS THAT DO DEVELOP. THREAT FOR TORNADOES IS MUCH LOWER GIVEN LIMITED LOW LEVEL DIRECTIONAL SHEAR BUT CAN`T RULE IT OUT ENTIRELY. ALL OF THIS IS OF COURSE CONDITIONAL ON MORNING CONVECTIVE TRENDS AND GETTING ENOUGH SYNOPTIC SCALE ASCENT/COOLING TO ERODE THE STOUT 850-750MB INVERSION. CONFIDENCE IN THIS SCENARIO IS NOT HIGH ENOUGH TO SUPPORT LIKELY POPS JUST YET AND WILL HOLD WITH HIGH END CHANCES. THESE CHANCES WILL CONTINUE INTO THE OVERNIGHT PERIOD AS LLJ STRENGTHENS ONCE AGAIN AND POSSIBLY SUPPORTS PERSISTENT CONVECTION FOR OUR CWA IF SOUTHWARD PUSH OF FRONTAL BOUNDARY MATERIALIZES. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 422 AM EDT WED JUN 18 2014 LITTLE SUBSTANTIVE CHANGE TO LONG TERM PERIOD. EXPECT PRODIGIOUS CONVECTION SPAWNING ALONG/DOWNSTREAM OF INTENSE INTERMOUNTAIN MID TROPOSPHERIC VORTEX TO CONTINUE INTO THIS WEEKEND. ACTIVE PATTERN WITH CONTINUATION OF CONVECTIVE INDUCED MESOVORTICIES AFFORDING TO INITIATE/RENEW TSRA ALONG/NORTH OF SURFACE FRONTAL BOUNDARY THAT PRESENTLY EXTENDS FROM NORTHERN NE TO CENTRAL WI THEN SOUTHEASTWARD THROUGH THE SOUTHERN GREAT LAKES REGION. WHILE STRONGEST INSTABILITY AND MORE SIGNIFICANT FOCUS FOR INITIATION REMAINS UPSTREAM OF CWA ON THU...HAVE CONTD CHC POP MENTION/HIGHEST IN SOUTHWEST CWA AS NORTHERN ONTARIO ANTICYCLONE SHIFTS SEWD AND ASSERTS RIDGING SOUTHWARD THROUGH LAKE HURON INTO NWRN OH...SHUNTING CONVECTIVE MAINTENANCE FARTHER SOUTH AS IT PROGRESSES DOWNSTREAM. FRIDAY PRESENTS EVEN HIGHER POTENTIAL FOR MORE WIDESPREAD CONVECTION AS LOBE OF SIGNIFICANT 30-50M/12 HR MID LEVEL HEIGHT FALLS PEELS THROUGH WESTERN GREAT LAKES AS PRIMARY UPSTREAM VORTEX BIFURCATES DOWNSTREAM RIDGE TO BECOME REXED ACROSS SOUTHERN MANITOBA. MID 80S/NEAR 70 SURFACE CONDITIONS YIELD MODERATE INSTABILITY 2500-3500 J/KG SBCAPE AND MODEST DEEP LAYER SHEAR. DIFFERENTIATED FRIDAY WITH LIKELY POPS SANS TIMING GIVEN BETTER SIGNALS AMID RICH THETA-E REGIME FIRMLY IN PLACE. THEREAFTER INCREASING MODEL DIVERGENCE NOTED WITH DEVOLUTION OF REXED SYSTEM WITH ECMWF/GEM MAINTAINING ORPHANED TROFFING ACROSS NORTHERN GREAT LAKES INTO NORTHERN PLAINS INTO NEXT WEEK AND GFS ESPECIALLY BTWN ECMWF AND GEM VS GFS RELEASE DOWNSTREAM THROUGH THE LOWER GREAT LAKES DYS5/6. POSSIBLE LULL SATURDAY THOUGH HIGHLY CONTINGENT ON FRIDAY CONVECTION LEADING TO SUBSTANTIAL OVERTURNING AND FAR SOUTHWARD BOUNDARY SHUNT. AT THIS TIME LOW CHANCE MENTION REMAINS GIVEN HIGH CONDITIONALITY. TREND DRY MONDAY NIGHT/TUESDAY AS DEEPER NORTH/NORTHEAST FLOW PER NORTHERN GREAT && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 140 PM EDT WED JUN 18 2014 SHALLOW/BRIEF MVFR CIGS ASSOCD/W TAIL END OF DECAYING CONV REMNANTS ACRS NW IN WILL MIX OUT QUICKLY INTO THIS AFTN. LTL SIGN YET OF WHERE/WHEN RENEWED CONV DVLPMNT WILL OCCUR AND AS SUCH WILL SIT TIGHT W/IMPLIED DRY TAF FCST THROUGH THE OVERNIGHT. MOST LIKELY SCENARIO IS FOR NEW CONVN TO INITIATE FM ERN IA EWD THROUGH NRN IL THIS EVENING AS LLJ KICKS UP AND THEN GROW UPSCALE INTO A FWD PROPAGATING MCS AS IT SPREADS EWD THROUGH THE SRN LAKES OVERNIGHT. OTRWS GUSTY SWRLY GRADIENT WINDS WILL SUBSIDE BY SUNSET. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...T SYNOPSIS...AGD SHORT TERM...AGD LONG TERM...MURPHY AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1011 AM EDT WED JUN 18 2014 .SYNOPSIS... ISSUED AT 422 AM EDT WED JUN 18 2014 PERIODS OF SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH THE NEXT SEVERAL DAYS AS A WEAK FRONTAL BOUNDARY SETS UP OVER THE SOUTHERN GREAT LAKES. THUNDERSTORMS ARE BEING AIDED BY VERY WARM AND HUMID AIRMASS CURRENTLY IN PLACE ACROSS THE REGION. HIGHS TODAY WILL BE IN THE UPPER 80S TO LOWER 90S WITH OVERNIGHT LOWS AROUND 70. && .UPDATE... ISSUED AT 1010 AM EDT WED JUN 18 2014 INTERESTING BUT COMPLICATED NR TERM THIS MORNING AS POTENT UPSTREAM MCV PIVOTS OUT OF SE MN. ATTENDANT BKN LINE OF CONVN FM SRN WI SWWD INTO ERN SHOWING SIGNS NOW OF FWD PROPAGATION INTO RAPIDLY GROWING INSTABILITY AXIS POSITIONED W-E ACRS THE SRN LAKES INVOF DECAYING CIRRUS SHIELD...AND NO DOUBT AUGMENTED W/POTENT 50KT MID LVL SPEED MAX. HWVR COMPLICATING FCTR IS OUTFLW BNDRY EXTENDING FM FAR NE IL ESE INTO NW OH THAT MAY WITH TIME INITIATE ADDNL CONVN AHD OF THE BOWING LINE MVG OUT OF SE WI. AT EITHER RATE IT WOULD APPEAR A MORE CONSIDERABLE RISK FOR SEVERE STORMS IS SHAPING UP FOR THIS AFTN. ZONE UPDATES WILL BE FORTHCOMING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 422 AM EDT WED JUN 18 2014 ACTIVE WEATHER PATTERN CONTINUES FOR THE SOUTHERN GREAT LAKES AS SEVERAL CONVECTIVELY ENHANCED SHORTWAVES EJECT OUT OF WESTERN CONUS UPPER LOW AND TRAVEL ALONG QUASI-STATIONARY E-W FRONTAL BOUNDARY DRAPED THROUGH THE REGION. STRONG LLJ AHEAD OF THE MAIN TROUGH IS STILL MAINTAINING A CONTINUAL FEED OF VERY HIGH THETA-E AIR INTO THE MIDWEST AND OHIO VALLEY...SUPPORTING UNSTABLE CONDITIONS. SIMILAR TO THE PREVIOUS NIGHT...CONVECTION HAS FIRED UPSTREAM ON THE NOSE OF THE LLJ/MOISTURE CONVERGENCE AND HAS SLOWLY DRIFTED EASTWARD. THE DIFFERENCE IS THAT STORM CLUSTERS HAVE BEEN A LITTLE MORE DISCREET AND DISORGANIZED THUS FAR. UPSCALE GROWTH/ORGANIZATION LIKELY INHIBITED BY VERY STRONG CAPPING INVERSION NOTED ON 00Z KILX AND KDVN SOUNDINGS AS WELL AS A LACK OF ANY CLEAR SYNOPTIC SCALE SHORTWAVE/LINEAR FORCING. STORM CLUSTERS TO OUR NORTH AND NORTHWEST HAVE GRADUALLY FILLED IN/CONGLOMERATED DURING THE PAST FEW HOURS THOUGH...THANKS TO NOCTURNAL STRENGTHENING OF LLJ AND ASSOCIATED INCREASE IN LOW LEVEL MOISTURE AVAILABLE UPSTREAM. QUESTION IS HOW WILL THIS ACTIVITY EVOLVE THROUGH THE MORNING AND INTO THE AFTERNOON. LATEST SURFACE OBS ACTUALLY SHOW A FAIRLY PRONOUNCED TEMP AND MOISTURE GRADIENT JUST NORTH OF OUR CWA. ISENTROPIC ASCENT ALONG AND NORTH OF THIS SURFACE BOUNDARY IS DRIVING MUCH OF THE CURRENT CONVECTION WHILE ATMOSPHERE REMAINS CAPPED TO THE SOUTH. NOTHING TO FORCE THIS FRONT SOUTHWARD THROUGH THE MORNING WITH CONTINUAL SOUTHWEST FLOW/WAA AND NO ORGANIZED COLD POOLS/OUTFLOW BOUNDARIES AS OF YET. THEREFORE EXPECT OUR CWA WILL REMAIN LARGELY DRY DURING THIS PERIOD. SITUATION MAY CHANGE BY THE AFTERNOON AND EVENING. 00Z MODELS SUGGEST THAT A SUBTLE WAVE ASSOCIATED WITH CONVECTION CURRENTLY OVER FAR NW IA AND SOUTHERN MN WILL PUSH ESE BY LATER TODAY. SIMULTANEOUS SOUTHWARD PUSH OF CANADIAN ANTICYCLONE MAY FORCE THE FRONTAL BOUNDARY SOUTHWARD A BIT...WITH THE HELP OF COLD LAKES AND OUTFLOW FROM MORNING THUNDERSTORMS. MODELS INDICATE THIS WILL LIKELY BE ENOUGH TO WEAKEN THE STRONG CAP IN PLACE ACROSS OUR CWA AND ALLOW STORMS TO DEVELOP AND/OR PROPAGATE INTO OUR AREA BY THE AFTERNOON AND EVENING. LATEST HRRR AND HI-RES WRF-NMM ARE GENERALLY IN LINE WITH THIS IDEA. IF THE CAP DOES BREAK AS EXPECTED THEN SEVERE WEATHER WILL BE QUITE POSSIBLE. MODIFIED FORECAST SOUNDINGS INDICATE AROUND 3000 J/KG OF SBCAPE ACROSS THE AREA BY THE AFTERNOON. 0-6KM BULK SHEAR IS NOT AS HIGH SOUTH OF I-80 BUT SUFFICIENT FOR ORGANIZED LINE SEGMENTS/BOWS GIVEN LARGELY UNIDIRECTIONAL WIND FIELDS. LARGE HAIL AND STRONG WINDS WOULD BE THE PRIMARY THREATS WITH ANY STORMS THAT DO DEVELOP. THREAT FOR TORNADOES IS MUCH LOWER GIVEN LIMITED LOW LEVEL DIRECTIONAL SHEAR BUT CAN`T RULE IT OUT ENTIRELY. ALL OF THIS IS OF COURSE CONDITIONAL ON MORNING CONVECTIVE TRENDS AND GETTING ENOUGH SYNOPTIC SCALE ASCENT/COOLING TO ERODE THE STOUT 850-750MB INVERSION. CONFIDENCE IN THIS SCENARIO IS NOT HIGH ENOUGH TO SUPPORT LIKELY POPS JUST YET AND WILL HOLD WITH HIGH END CHANCES. THESE CHANCES WILL CONTINUE INTO THE OVERNIGHT PERIOD AS LLJ STRENGTHENS ONCE AGAIN AND POSSIBLY SUPPORTS PERSISTENT CONVECTION FOR OUR CWA IF SOUTHWARD PUSH OF FRONTAL BOUNDARY MATERIALIZES. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 422 AM EDT WED JUN 18 2014 LITTLE SUBSTANTIVE CHANGE TO LONG TERM PERIOD. EXPECT PRODIGIOUS CONVECTION SPAWNING ALONG/DOWNSTREAM OF INTENSE INTERMOUNTAIN MID TROPOSPHERIC VORTEX TO CONTINUE INTO THIS WEEKEND. ACTIVE PATTERN WITH CONTINUATION OF CONVECTIVE INDUCED MESOVORTICIES AFFORDING TO INITIATE/RENEW TSRA ALONG/NORTH OF SURFACE FRONTAL BOUNDARY THAT PRESENTLY EXTENDS FROM NORTHERN NE TO CENTRAL WI THEN SOUTHEASTWARD THROUGH THE SOUTHERN GREAT LAKES REGION. WHILE STRONGEST INSTABILITY AND MORE SIGNIFICANT FOCUS FOR INITIATION REMAINS UPSTREAM OF CWA ON THU...HAVE CONTD CHC POP MENTION/HIGHEST IN SOUTHWEST CWA AS NORTHERN ONTARIO ANTICYCLONE SHIFTS SEWD AND ASSERTS RIDGING SOUTHWARD THROUGH LAKE HURON INTO NWRN OH...SHUNTING CONVECTIVE MAINTENANCE FARTHER SOUTH AS IT PROGRESSES DOWNSTREAM. FRIDAY PRESENTS EVEN HIGHER POTENTIAL FOR MORE WIDESPREAD CONVECTION AS LOBE OF SIGNIFICANT 30-50M/12 HR MID LEVEL HEIGHT FALLS PEELS THROUGH WESTERN GREAT LAKES AS PRIMARY UPSTREAM VORTEX BIFURCATES DOWNSTREAM RIDGE TO BECOME REXED ACROSS SOUTHERN MANITOBA. MID 80S/NEAR 70 SURFACE CONDITIONS YIELD MODERATE INSTABILITY 2500-3500 J/KG SBCAPE AND MODEST DEEP LAYER SHEAR. DIFFERENTIATED FRIDAY WITH LIKELY POPS SANS TIMING GIVEN BETTER SIGNALS AMID RICH THETA-E REGIME FIRMLY IN PLACE. THEREAFTER INCREASING MODEL DIVERGENCE NOTED WITH DEVOLUTION OF REXED SYSTEM WITH ECMWF/GEM MAINTAINING ORPHANED TROFFING ACROSS NORTHERN GREAT LAKES INTO NORTHERN PLAINS INTO NEXT WEEK AND GFS ESPECIALLY BTWN ECMWF AND GEM VS GFS RELEASE DOWNSTREAM THROUGH THE LOWER GREAT LAKES DYS5/6. POSSIBLE LULL SATURDAY THOUGH HIGHLY CONTINGENT ON FRIDAY CONVECTION LEADING TO SUBSTANTIAL OVERTURNING AND FAR SOUTHWARD BOUNDARY SHUNT. AT THIS TIME LOW CHANCE MENTION REMAINS GIVEN HIGH CONDITIONALITY. TREND DRY MONDAY NIGHT/TUESDAY AS DEEPER NORTH/NORTHEAST FLOW PER NORTHERN GREAT && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 558 AM EDT WED JUN 18 2014 WIDESPREAD THUNDERSTORMS HAVE DEVELOPED ALONG AND NORTH OF A WARM FRONT CURRENTLY STRETCHED FROM SOUTHERN MICHIGAN THROUGH NORTHERN IOWA WITH DRY AND CAPPED CONDITIONS SOUTH OF THAT FRONT IN OUR AREA. FRONT EXPECTED TO RETREAT SOUTHWARD LATER TODAY THOUGH AS SHORTWAVE TROUGH PASSES THROUGH THE REGION. THIS WILL LIKELY WEAKEN THE CAP AND ALLOW THUNDERSTORMS TO DEVELOP AND/OR PROPAGATE INTO NORTHERN INDIANA. SEVERAL HI-RES MODELS SUPPORT THIS SCENARIO BUT DISAGREE ON EXACT TIMING. FOR NOW THINK THE BEST CHANCE WILL BE AFTER 16Z AT KSBN AND AFTER 18Z AT KFWA. SCATTERED CONVECTION WILL LIKELY LINGER THROUGH THE OVERNIGHT PERIOD AS LLJ RAMPS UP ONCE AGAIN. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...T SYNOPSIS...AGD SHORT TERM...AGD LONG TERM...MURPHY AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
559 AM EDT WED JUN 18 2014 .SYNOPSIS... ISSUED AT 422 AM EDT WED JUN 18 2014 PERIODS OF SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH THE NEXT SEVERAL DAYS AS A WEAK FRONTAL BOUNDARY SETS UP OVER THE SOUTHERN GREAT LAKES. THUNDERSTORMS ARE BEING AIDED BY VERY WARM AND HUMID AIRMASS CURRENTLY IN PLACE ACROSS THE REGION. HIGHS TODAY WILL BE IN THE UPPER 80S TO LOWER 90S WITH OVERNIGHT LOWS AROUND 70. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 422 AM EDT WED JUN 18 2014 ACTIVE WEATHER PATTERN CONTINUES FOR THE SOUTHERN GREAT LAKES AS SEVERAL CONVECTIVELY ENHANCED SHORTWAVES EJECT OUT OF WESTERN CONUS UPPER LOW AND TRAVEL ALONG QUASI-STATIONARY E-W FRONTAL BOUNDARY DRAPED THROUGH THE REGION. STRONG LLJ AHEAD OF THE MAIN TROUGH IS STILL MAINTAINING A CONTINUAL FEED OF VERY HIGH THETA-E AIR INTO THE MIDWEST AND OHIO VALLEY...SUPPORTING UNSTABLE CONDITIONS. SIMILAR TO THE PREVIOUS NIGHT...CONVECTION HAS FIRED UPSTREAM ON THE NOSE OF THE LLJ/MOISTURE CONVERGENCE AND HAS SLOWLY DRIFTED EASTWARD. THE DIFFERENCE IS THAT STORM CLUSTERS HAVE BEEN A LITTLE MORE DISCREET AND DISORGANIZED THUS FAR. UPSCALE GROWTH/ORGANIZATION LIKELY INHIBITED BY VERY STRONG CAPPING INVERSION NOTED ON 00Z KILX AND KDVN SOUNDINGS AS WELL AS A LACK OF ANY CLEAR SYNOPTIC SCALE SHORTWAVE/LINEAR FORCING. STORM CLUSTERS TO OUR NORTH AND NORTHWEST HAVE GRADUALLY FILLED IN/CONGLOMERATED DURING THE PAST FEW HOURS THOUGH...THANKS TO NOCTURNAL STRENGTHENING OF LLJ AND ASSOCIATED INCREASE IN LOW LEVEL MOISTURE AVAILABLE UPSTREAM. QUESTION IS HOW WILL THIS ACTIVITY EVOLVE THROUGH THE MORNING AND INTO THE AFTERNOON. LATEST SURFACE OBS ACTUALLY SHOW A FAIRLY PRONOUNCED TEMP AND MOISTURE GRADIENT JUST NORTH OF OUR CWA. ISENTROPIC ASCENT ALONG AND NORTH OF THIS SURFACE BOUNDARY IS DRIVING MUCH OF THE CURRENT CONVECTION WHILE ATMOSPHERE REMAINS CAPPED TO THE SOUTH. NOTHING TO FORCE THIS FRONT SOUTHWARD THROUGH THE MORNING WITH CONTINUAL SOUTHWEST FLOW/WAA AND NO ORGANIZED COLD POOLS/OUTFLOW BOUNDARIES AS OF YET. THEREFORE EXPECT OUR CWA WILL REMAIN LARGELY DRY DURING THIS PERIOD. SITUATION MAY CHANGE BY THE AFTERNOON AND EVENING. 00Z MODELS SUGGEST THAT A SUBTLE WAVE ASSOCIATED WITH CONVECTION CURRENTLY OVER FAR NW IA AND SOUTHERN MN WILL PUSH ESE BY LATER TODAY. SIMULTANEOUS SOUTHWARD PUSH OF CANADIAN ANTICYCLONE MAY FORCE THE FRONTAL BOUNDARY SOUTHWARD A BIT...WITH THE HELP OF COLD LAKES AND OUTFLOW FROM MORNING THUNDERSTORMS. MODELS INDICATE THIS WILL LIKELY BE ENOUGH TO WEAKEN THE STRONG CAP IN PLACE ACROSS OUR CWA AND ALLOW STORMS TO DEVELOP AND/OR PROPAGATE INTO OUR AREA BY THE AFTERNOON AND EVENING. LATEST HRRR AND HI-RES WRF-NMM ARE GENERALLY IN LINE WITH THIS IDEA. IF THE CAP DOES BREAK AS EXPECTED THEN SEVERE WEATHER WILL BE QUITE POSSIBLE. MODIFIED FORECAST SOUNDINGS INDICATE AROUND 3000 J/KG OF SBCAPE ACROSS THE AREA BY THE AFTERNOON. 0-6KM BULK SHEAR IS NOT AS HIGH SOUTH OF I-80 BUT SUFFICIENT FOR ORGANIZED LINE SEGMENTS/BOWS GIVEN LARGELY UNIDIRECTIONAL WIND FIELDS. LARGE HAIL AND STRONG WINDS WOULD BE THE PRIMARY THREATS WITH ANY STORMS THAT DO DEVELOP. THREAT FOR TORNADOES IS MUCH LOWER GIVEN LIMITED LOW LEVEL DIRECTIONAL SHEAR BUT CAN`T RULE IT OUT ENTIRELY. ALL OF THIS IS OF COURSE CONDITIONAL ON MORNING CONVECTIVE TRENDS AND GETTING ENOUGH SYNOPTIC SCALE ASCENT/COOLING TO ERODE THE STOUT 850-750MB INVERSION. CONFIDENCE IN THIS SCENARIO IS NOT HIGH ENOUGH TO SUPPORT LIKELY POPS JUST YET AND WILL HOLD WITH HIGH END CHANCES. THESE CHANCES WILL CONTINUE INTO THE OVERNIGHT PERIOD AS LLJ STRENGTHENS ONCE AGAIN AND POSSIBLY SUPPORTS PERSISTENT CONVECTION FOR OUR CWA IF SOUTHWARD PUSH OF FRONTAL BOUNDARY MATERIALIZES. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 422 AM EDT WED JUN 18 2014 LITTLE SUBSTANTIVE CHANGE TO LONG TERM PERIOD. EXPECT PRODIGIOUS CONVECTION SPAWNING ALONG/DOWNSTREAM OF INTENSE INTERMOUNTAIN MID TROPOSPHERIC VORTEX TO CONTINUE INTO THIS WEEKEND. ACTIVE PATTERN WITH CONTINUATION OF CONVECTIVE INDUCED MESOVORTICIES AFFORDING TO INITIATE/RENEW TSRA ALONG/NORTH OF SURFACE FRONTAL BOUNDARY THAT PRESENTLY EXTENDS FROM NORTHERN NE TO CENTRAL WI THEN SOUTHEASTWARD THROUGH THE SOUTHERN GREAT LAKES REGION. WHILE STRONGEST INSTABILITY AND MORE SIGNIFICANT FOCUS FOR INITIATION REMAINS UPSTREAM OF CWA ON THU...HAVE CONTD CHC POP MENTION/HIGHEST IN SOUTHWEST CWA AS NORTHERN ONTARIO ANTICYCLONE SHIFTS SEWD AND ASSERTS RIDGING SOUTHWARD THROUGH LAKE HURON INTO NWRN OH...SHUNTING CONVECTIVE MAINTENANCE FARTHER SOUTH AS IT PROGRESSES DOWNSTREAM. FRIDAY PRESENTS EVEN HIGHER POTENTIAL FOR MORE WIDESPREAD CONVECTION AS LOBE OF SIGNIFICANT 30-50M/12 HR MID LEVEL HEIGHT FALLS PEELS THROUGH WESTERN GREAT LAKES AS PRIMARY UPSTREAM VORTEX BIFURCATES DOWNSTREAM RIDGE TO BECOME REXED ACROSS SOUTHERN MANITOBA. MID 80S/NEAR 70 SURFACE CONDITIONS YIELD MODERATE INSTABILITY 2500-3500 J/KG SBCAPE AND MODEST DEEP LAYER SHEAR. DIFFERENTIATED FRIDAY WITH LIKELY POPS SANS TIMING GIVEN BETTER SIGNALS AMID RICH THETA-E REGIME FIRMLY IN PLACE. THEREAFTER INCREASING MODEL DIVERGENCE NOTED WITH DEVOLUTION OF REXED SYSTEM WITH ECMWF/GEM MAINTAINING ORPHANED TROFFING ACROSS NORTHERN GREAT LAKES INTO NORTHERN PLAINS INTO NEXT WEEK AND GFS ESPECIALLY BTWN ECMWF AND GEM VS GFS RELEASE DOWNSTREAM THROUGH THE LOWER GREAT LAKES DYS5/6. POSSIBLE LULL SATURDAY THOUGH HIGHLY CONTINGENT ON FRIDAY CONVECTION LEADING TO SUBSTANTIAL OVERTURNING AND FAR SOUTHWARD BOUNDARY SHUNT. AT THIS TIME LOW CHANCE MENTION REMAINS GIVEN HIGH CONDITIONALITY. TREND DRY MONDAY NIGHT/TUESDAY AS DEEPER NORTH/NORTHEAST FLOW PER NORTHERN GREAT && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 558 AM EDT WED JUN 18 2014 WIDESPREAD THUNDERSTORMS HAVE DEVELOPED ALONG AND NORTH OF A WARM FRONT CURRENTLY STRETCHED FROM SOUTHERN MICHIGAN THROUGH NORTHERN IOWA WITH DRY AND CAPPED CONDITIONS SOUTH OF THAT FRONT IN OUR AREA. FRONT EXPECTED TO RETREAT SOUTHWARD LATER TODAY THOUGH AS SHORTWAVE TROUGH PASSES THROUGH THE REGION. THIS WILL LIKELY WEAKEN THE CAP AND ALLOW THUNDERSTORMS TO DEVELOP AND/OR PROPAGATE INTO NORTHERN INDIANA. SEVERAL HI-RES MODELS SUPPORT THIS SCENARIO BUT DISAGREE ON EXACT TIMING. FOR NOW THINK THE BEST CHANCE WILL BE AFTER 16Z AT KSBN AND AFTER 18Z AT KFWA. SCATTERED CONVECTION WILL LIKELY LINGER THROUGH THE OVERNIGHT PERIOD AS LLJ RAMPS UP ONCE AGAIN. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...AGD SHORT TERM...AGD LONG TERM...MURPHY AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
422 AM EDT WED JUN 18 2014 .SYNOPSIS... ISSUED AT 422 AM EDT WED JUN 18 2014 PERIODS OF SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH THE NEXT SEVERAL DAYS AS A WEAK FRONTAL BOUNDARY SETS UP OVER THE SOUTHERN GREAT LAKES. THUNDERSTORMS ARE BEING AIDED BY VERY WARM AND HUMID AIRMASS CURRENTLY IN PLACE ACROSS THE REGION. HIGHS TODAY WILL BE IN THE UPPER 80S TO LOWER 90S WITH OVERNIGHT LOWS AROUND 70. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 422 AM EDT WED JUN 18 2014 ACTIVE WEATHER PATTERN CONTINUES FOR THE SOUTHERN GREAT LAKES AS SEVERAL CONVECTIVELY ENHANCED SHORTWAVES EJECT OUT OF WESTERN CONUS UPPER LOW AND TRAVEL ALONG QUASI-STATIONARY E-W FRONTAL BOUNDARY DRAPED THROUGH THE REGION. STRONG LLJ AHEAD OF THE MAIN TROUGH IS STILL MAINTAINING A CONTINUAL FEED OF VERY HIGH THETA-E AIR INTO THE MIDWEST AND OHIO VALLEY...SUPPORTING UNSTABLE CONDITIONS. SIMILAR TO THE PREVIOUS NIGHT...CONVECTION HAS FIRED UPSTREAM ON THE NOSE OF THE LLJ/MOISTURE CONVERGENCE AND HAS SLOWLY DRIFTED EASTWARD. THE DIFFERENCE IS THAT STORM CLUSTERS HAVE BEEN A LITTLE MORE DISCREET AND DISORGANIZED THUS FAR. UPSCALE GROWTH/ORGANIZATION LIKELY INHIBITED BY VERY STRONG CAPPING INVERSION NOTED ON 00Z KILX AND KDVN SOUNDINGS AS WELL AS A LACK OF ANY CLEAR SYNOPTIC SCALE SHORTWAVE/LINEAR FORCING. STORM CLUSTERS TO OUR NORTH AND NORTHWEST HAVE GRADUALLY FILLED IN/CONGLOMERATED DURING THE PAST FEW HOURS THOUGH...THANKS TO NOCTURNAL STRENGTHENING OF LLJ AND ASSOCIATED INCREASE IN LOW LEVEL MOISTURE AVAILABLE UPSTREAM. QUESTION IS HOW WILL THIS ACTIVITY EVOLVE THROUGH THE MORNING AND INTO THE AFTERNOON. LATEST SURFACE OBS ACTUALLY SHOW A FAIRLY PRONOUNCED TEMP AND MOISTURE GRADIENT JUST NORTH OF OUR CWA. ISENTROPIC ASCENT ALONG AND NORTH OF THIS SURFACE BOUNDARY IS DRIVING MUCH OF THE CURRENT CONVECTION WHILE ATMOSPHERE REMAINS CAPPED TO THE SOUTH. NOTHING TO FORCE THIS FRONT SOUTHWARD THROUGH THE MORNING WITH CONTINUAL SOUTHWEST FLOW/WAA AND NO ORGANIZED COLD POOLS/OUTFLOW BOUNDARIES AS OF YET. THEREFORE EXPECT OUR CWA WILL REMAIN LARGELY DRY DURING THIS PERIOD. SITUATION MAY CHANGE BY THE AFTERNOON AND EVENING. 00Z MODELS SUGGEST THAT A SUBTLE WAVE ASSOCIATED WITH CONVECTION CURRENTLY OVER FAR NW IA AND SOUTHERN MN WILL PUSH ESE BY LATER TODAY. SIMULTANEOUS SOUTHWARD PUSH OF CANADIAN ANTICYCLONE MAY FORCE THE FRONTAL BOUNDARY SOUTHWARD A BIT...WITH THE HELP OF COLD LAKES AND OUTFLOW FROM MORNING THUNDERSTORMS. MODELS INDICATE THIS WILL LIKELY BE ENOUGH TO WEAKEN THE STRONG CAP IN PLACE ACROSS OUR CWA AND ALLOW STORMS TO DEVELOP AND/OR PROPAGATE INTO OUR AREA BY THE AFTERNOON AND EVENING. LATEST HRRR AND HI-RES WRF-NMM ARE GENERALLY IN LINE WITH THIS IDEA. IF THE CAP DOES BREAK AS EXPECTED THEN SEVERE WEATHER WILL BE QUITE POSSIBLE. MODIFIED FORECAST SOUNDINGS INDICATE AROUND 3000 J/KG OF SBCAPE ACROSS THE AREA BY THE AFTERNOON. 0-6KM BULK SHEAR IS NOT AS HIGH SOUTH OF I-80 BUT SUFFICIENT FOR ORGANIZED LINE SEGMENTS/BOWS GIVEN LARGELY UNIDIRECTIONAL WIND FIELDS. LARGE HAIL AND STRONG WINDS WOULD BE THE PRIMARY THREATS WITH ANY STORMS THAT DO DEVELOP. THREAT FOR TORNADOES IS MUCH LOWER GIVEN LIMITED LOW LEVEL DIRECTIONAL SHEAR BUT CAN`T RULE IT OUT ENTIRELY. ALL OF THIS IS OF COURSE CONDITIONAL ON MORNING CONVECTIVE TRENDS AND GETTING ENOUGH SYNOPTIC SCALE ASCENT/COOLING TO ERODE THE STOUT 850-750MB INVERSION. CONFIDENCE IN THIS SCENARIO IS NOT HIGH ENOUGH TO SUPPORT LIKELY POPS JUST YET AND WILL HOLD WITH HIGH END CHANCES. THESE CHANCES WILL CONTINUE INTO THE OVERNIGHT PERIOD AS LLJ STRENGTHENS ONCE AGAIN AND POSSIBLY SUPPORTS PERSISTENT CONVECTION FOR OUR CWA IF SOUTHWARD PUSH OF FRONTAL BOUNDARY MATERIALIZES. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 422 AM EDT WED JUN 18 2014 LITTLE SUBSTANTIVE CHANGE TO LONG TERM PERIOD. EXPECT PRODIGIOUS CONVECTION SPAWNING ALONG/DOWNSTREAM OF INTENSE INTERMOUNTAIN MID TROPOSPHERIC VORTEX TO CONTINUE INTO THIS WEEKEND. ACTIVE PATTERN WITH CONTINUATION OF CONVECTIVE INDUCED MESOVORTICIES AFFORDING TO INITIATE/RENEW TSRA ALONG/NORTH OF SURFACE FRONTAL BOUNDARY THAT PRESENTLY EXTENDS FROM NORTHERN NE TO CENTRAL WI THEN SOUTHEASTWARD THROUGH THE SOUTHERN GREAT LAKES REGION. WHILE STRONGEST INSTABILITY AND MORE SIGNIFICANT FOCUS FOR INITIATION REMAINS UPSTREAM OF CWA ON THU...HAVE CONTD CHC POP MENTION/HIGHEST IN SOUTHWEST CWA AS NORTHERN ONTARIO ANTICYCLONE SHIFTS SEWD AND ASSERTS RIDGING SOUTHWARD THROUGH LAKE HURON INTO NWRN OH...SHUNTING CONVECTIVE MAINTENANCE FARTHER SOUTH AS IT PROGRESSES DOWNSTREAM. FRIDAY PRESENTS EVEN HIGHER POTENTIAL FOR MORE WIDESPREAD CONVECTION AS LOBE OF SIGNIFICANT 30-50M/12 HR MID LEVEL HEIGHT FALLS PEELS THROUGH WESTERN GREAT LAKES AS PRIMARY UPSTREAM VORTEX BIFURCATES DOWNSTREAM RIDGE TO BECOME REXED ACROSS SOUTHERN MANITOBA. MID 80S/NEAR 70 SURFACE CONDITIONS YIELD MODERATE INSTABILITY 2500-3500 J/KG SBCAPE AND MODEST DEEP LAYER SHEAR. DIFFERENTIATED FRIDAY WITH LIKELY POPS SANS TIMING GIVEN BETTER SIGNALS AMID RICH THETA-E REGIME FIRMLY IN PLACE. THEREAFTER INCREASING MODEL DIVERGENCE NOTED WITH DEVOLUTION OF REXED SYSTEM WITH ECMWF/GEM MAINTAINING ORPHANED TROFFING ACROSS NORTHERN GREAT LAKES INTO NORTHERN PLAINS INTO NEXT WEEK AND GFS ESPECIALLY BTWN ECMWF AND GEM VS GFS RELEASE DOWNSTREAM THROUGH THE LOWER GREAT LAKES DYS5/6. POSSIBLE LULL SATURDAY THOUGH HIGHLY CONTINGENT ON FRIDAY CONVECTION LEADING TO SUBSTANTIAL OVERTURNING AND FAR SOUTHWARD BOUNDARY SHUNT. AT THIS TIME LOW CHANCE MENTION REMAINS GIVEN HIGH CONDITIONALITY. TREND DRY MONDAY NIGHT/TUESDAY AS DEEPER NORTH/NORTHEAST FLOW PER NORTHERN GREAT LAKES SURFACE RIDGING SHOULD FINALLY AFFORD DRIER/SUBSIDENT REGIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 138 AM EDT WED JUN 18 2014 CONVECTION CURRENTLY DEVELOPING ALONG AND NORTH OF STATIONARY FRONT OVER SOUTHERN WISCONSIN AND LAKE MICHIGAN AS LLJ INCREASES AND ADVECTS BETTER MOISTURE INTO THE REGION. STRONG CAPPING INVERSION HAS LIMITED UPSCALE GROWTH SO FAR THIS EVENING BUT EXPECT THUNDERSTORMS TO EXPAND ALONG THE FRONT BY LATER TONIGHT. THIS FRONT LOOKS TO REMAIN NORTH OF THE TERMINALS THOUGH AND HI- RES MODELS KEEP BULK OF THE CONVECTION NORTH OF THE AREA THROUGH LATE MORNING. HAVE THEREFORE KEPT THE TAFS DRY/VFR THROUGH THE THIS PERIOD. AFTERNOON MAY BE A DIFFERENT STORY AS MODELS SUGGEST WEAK SHORTWAVE WILL ENTER THE REGION AND CAPITALIZE ON HIGHLY UNSTABLE ENVIRONMENT. CHANCES FOR THUNDERSTORMS WILL INCREASE BEGINNING AROUND 18Z BUT CONFIDENCE IN TIMING AND LOCATION IS TOO LOW FOR INCLUSION IN THE TAFS AT THIS TIME. WILL FINISH COMBING THROUGH THE 00Z DATA AND ATTEMPT TO NAIL DOWN DETAILS WITH THE 12Z ISSUANCE. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...AGD SHORT TERM...AGD LONG TERM...MURPHY AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
355 PM CDT Wed Jun 18 2014 ...Updated for long term discussion... .SHORT TERM...(This evening through Thursday) ISSUED AT 251 PM CDT WED JUN 18 2014 A minor upper level trough is currently moving through western Kansas, with the stronger dynamics centered off to the north of our CWA. There is a cold front in the vicinity from Hays to north of Syracuse in Hamilton County as of 20z. A dry-line has formed and was from approximately Liberal to Garden City to Hill City at 20z. There was a lower level wave which moved up from the Texas Panhandle earlier this afternoon, which shoved the dry-line northeastward into the cold front, causing the cold front to bow northward in the Ness City/Hays area. This dry-line intrusion into the cold front also slowed the progress of the front to the southeast. A fairly good amount of mid to high level clouds covered most of the CWA at 20z, and a single storm formed near Scott City between 19Z and 20Z. The short term models of the RUC, HRRR and ARW all backed off on a solid line of storms forming along the dry-line this afternoon, but rather a patchy line of storms. There will still probably be a few isolated severe storms with quarter size hail, but do not think the severe storms will be widespread or very big hail (quarters). Will monitor SPC for a Watch. Overnight, the precipitation band from this afternoon should move east, with another surface low moving up from Oklahoma into the P28 area. The aforementioned front will progress southeast through our CWA and be near a Pratt to Coldwater line by 12Z in the morning. Therefore, with greater moisture available in the southeast zones, will increase Pops there toward 12Z, and then spread the Pops back to the northwest during the day Thursday. SPC`s Day2 outlook has about our southeast 1/3rd of the CWA in a slight risk. We will be cooler in the afternoon, with the cold front south of us. Have to agree with SPC`s assessment though, with the NAM model showing 3700 J/Kg of MuCape in our eastern zones, and 24 to 27Kts of bulk shear in that same zone Tuesday at 21Z. There will likely be some more severe storms, again with Quarters to a little larger hail. The TOR threat looks minimal, but some 60kt winds could easily mix down. As for Max/Min temperatures, I did not change anything. Lows tonight will be elevated in the 60F (NW) to 72F (SE) range. On Thursday, it will be cooler with maximum temperatures ranging from the mid 80s north of I-70 and upper 80s down south along the Oklahoma border. .LONG TERM...(Thursday night through Wednesday) ISSUED AT 346 PM CDT WED JUN 18 2014 The mid to upper level flow will become zonal by later this week and into the weekend. This will allow for lee troughing and a dryline situated across far western Kansas. Afternoon and early nighttime thunderstorms cannot be ruled out. But in the absence of upslope flow this far south, and with the lack of low level baroclinicity and a well defined upper level jet, organized thunderstorm activity will probably stay farther north through Saturday. High temperatures will be in the lower 90s through Saturday with lows mainly in the 60s. Thunderstorm chances are higher by late Sunday as a weak shortwave trough embedded in zonal flow traverses western Kansas. Organized thunderstorm activity is possible into Monday with this feature, along with cooler temperatures by Monday. Thunderstorm chances may diminish by late Monday and Tuesday as weak surface high pressure builds into western Kansas. However, by late Tuesday and into mid to late next week, there will be more opportunities for thunderstorms as westerly to northwesterly mid to high level flow persists, along with weak capping and plentiful low level moisture. High temperatures will be held down by cloud cover and convective debris. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 1159 AM CDT WED JUN 18 2014 basically, conditions will be VFR through this evening and into the overnight hours. A line of strong storms is expected to develop around 21-22z from west of KHYS south to near KDDC to just east of KLBL and points southward. Cigs will be elevated, at approximately bkn050cb, and vsbys should remain good. If a thunderstorm develops right over a TAF site, such as KDDC, vsby could go down for a short period. The main hazard with these storms this afternoon and evening will be hail to the size of quarters. There is also a chance for storms overnight, mainly in the KHYS and KDDC TAF sites. && .PRELIMINARY POINT TEMPS/POPS... DDC 67 87 63 91 / 20 30 30 20 GCK 65 86 62 92 / 20 10 10 20 EHA 63 87 63 91 / 20 10 10 20 LBL 67 89 64 92 / 20 20 20 20 HYS 68 86 62 91 / 20 20 30 20 P28 72 89 67 91 / 30 50 60 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Burke LONG TERM...Finch AVIATION...Burke
AREA FORECAST DISCUSSION
NWS WICHITA KS
319 PM CDT WED JUN 18 2014 .SYNOPSIS... ISSUED AT 317 PM CDT WED JUN 18 2014 UPPER LEVEL DATA ANALYSIS ENDING AT 19Z SHOWS A CLOSED LOW AT 500 MB OVER SOUTHWEST MONTANA. SOUTHWESTERLY FLOW CONTINUES ACROSS THE REGION AS A RESULT OF THIS LOW. THIS LOW CONTINUES TO MOVE SLOWLY NORTHEASTWARD. SATELLITE DATA LOOP ENDING AT 1915Z SHOWS AN AREA OF ACCAS THAT HAS EXTENDED FROM THE TEXAS PANHANDLE INTO CENTRAL KANSAS. THIS HAS BEEN PRESENT FOR SEVERAL HOURS AND OUTLINES THE AREA OF FAVORED CONVECTIVE INITIATION THIS AFTERNOON. AT THE SURFACE...LOW PRESSURE WAS CENTERED OVER SOUTHCENTAL SOUTH DAKOTA. A COLD FRONT EXTENDS FROM THIS LOW DOWN TO NEAR KODX-KTQK-KLIC. A DRYLINE EXTENDS FROM JUST WEST OF KGCK...SOUTH TO JUST WEST OF KLBL INTO THE OKLAHOMA AND TEXAS PANHANDLE. CONVECTIVE DEVELOPMENT HAS INITIATED ACROSS WEST TEXAS ALONG THE AFOREMENTIONED FAVORED AREA. THIS IS PRETTY CLOSE TO WHERE THE 17Z HRRR RUN HAS SHOWN IT. MAIN FORECAST CHALLENGE REMAINS CONVECTION. COOK && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 317 PM CDT WED JUN 18 2014 THE TREND OF THE HRRR RUNS FOR CONVECTION THIS EVENING CONTINUES TO SHOW MORE RAINFALL FOR A GOOD PORTION OF THE FORECAST AREA. THIS IS A DIVERGENCE TO THE OTHER NWP...BUT GIVEN ITS ACCURACY AND PERFORMANCE...WILL MAKE ADJUSTMENTS TO THE FORECAST FOR TONIGHT. AS FAR AS SEVERE GOES...SHEAR/BUOYANCY COMBINATIONS SUGGEST POTENTIAL FOR ORGANIZED CONVECTION ACROSS WESTERN KANSAS. AS ONE MOVES EAST...DEEP LAYER SHEAR FALLS BELOW 20 KNOTS BEFORE YOU REACH INTERSTATE 135. THIS SHOULD PRECLUDE SEVERE CONVECTION EAST OF INTERSTATE 135. THE AFOREMENTIONED COLD FRONT WILL MOVE SOUTH INTO THE FORECAST AREA THURSDAY. THIS WILL BE THE FOCUS FOR CONVECTION THURSDAY AFTERNOON. SHEAR/BUOYANCY COMBINATIONS AGAIN LOOK FAVORABLE...THOUGH ON THE LOWER END OF THAT FAVORABILITY FOR ORGANIZED CONVECTION FOR SEVERE WEATHER. THIS FAVORABILITY WILL REMAIN IN THE VICINITY OF THE FRONT. IF STORMS STRAY FROM OR ORGANIZE AND MOVE AWAY FROM THE FRONT AND OUTRUN THE FAVORABLE DEEP LAYER SHEAR...THEY SHOULD WEAKEN. COOK .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 317 PM CDT WED JUN 18 2014 INTO THE WEEKEND...THE QUASISTATIONARY FRONT REMAINS AROUND THE REGION. NWP IS IN SOME DISARRAY WITH THE POSITION OF THE BOUNDARY...AFFECTED BY OUTFLOWS AND COLD POOLS. CONFIDENCE IN CONVECTION LOCATION IS QUITE LOW. THAT SAID...CONFIDENCE IS HIGH THAT THE FRONT REMAINS IN CLOSE ENOUGH PROXIMITY TO THE FORECAST AREA INTO THE MIDDLE OF NEXT WEEK...WITH FAVORABLE CONDITIONS FOR LATE AFTERNOON AND NOCTURNAL CONVECTION. SEVERE CONDITIONS WILL BE FAVORABLE NEAR THE STALLED FRONT...WHICH SHEAR/BUOYANCY COMBINATIONS ARE MOST FAVORABLE. COOK && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1217 PM CDT WED JUN 18 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. VISIBLE SATELLITE DETECTING SOME MID-LEVEL MOISTURE ADVECTING INTO SOUTH CENTRAL KANSAS...WITH BASES IN THE 120-150K RANGE. DIURNAL MIXING ALSO PRODUCING SOME CUMULUS WITH BASES 2-3K. OVERALL...MOISTURE IS LIMITED. SURFACE FRONTAL BOUNDARY REMAINS DRAPED ACROSS NORTHWEST KANSAS. CONVERGENCE ALONG THE FRONTAL BOUNDARY ONLY MODEST...WHICH COMBINED WITH LIMITED MOISTURE PUTS INTO QUESTION CONVECTIVE INITIATION LOCATION AND TIMING. WEAK DISTURBANCE MOVING NORTHEAST OUT OF NEW MEXICO COULD HELP INCREASE CONVERGENCE AND LIFT ALONG THE THE FRONT AND COOL MID-LEVEL TEMPERATURES JUST ENOUGH TO ALLOW ISOLATED STORMS TO FIRE. WILL FOLLOW PREVIOUS FORECAST TREND OF ONLY INCLUDING VCTS AT KRSL...BUT DECIDED TO BACK-OFF INITIATION TIME UNTIL AFTER 00 UTC. PASSAGE OF UPPER WAVE WILL DECREASE CHANCES OF STORMS AFTER 06 UTC. SOME SIGNAL THAT SCATTERED LOW VFR OR HIGH-END MVFR CIGS COULD ADVECT INTO SOUTH CENTRAL AND SOUTHEAST KANSAS BETWEEN 11-12 UTC...BUT NOT CONFIDENT ENOUGH TO INTRODUCE CEILINGS BASED ON DIFFERENCE IN OPERATIONAL MODELS AND CORROBORATION WITH SREF/NARRE-TL. SF && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 73 90 70 90 / 20 50 70 30 HUTCHINSON 73 90 69 91 / 30 50 70 20 NEWTON 72 88 69 90 / 20 50 70 20 ELDORADO 72 86 68 88 / 20 60 70 30 WINFIELD-KWLD 73 88 70 90 / 20 50 60 30 RUSSELL 70 89 66 92 / 50 40 40 20 GREAT BEND 70 89 67 92 / 50 40 50 20 SALINA 73 90 68 92 / 40 50 60 20 MCPHERSON 72 89 68 91 / 30 50 70 20 COFFEYVILLE 74 85 70 88 / 20 50 50 30 CHANUTE 73 85 69 88 / 30 50 50 30 IOLA 73 85 69 88 / 30 50 50 30 PARSONS-KPPF 73 85 70 88 / 30 50 50 30 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
255 PM CDT Wed Jun 18 2014 ...Updated for the short term discussion... .SHORT TERM...(This evening through Thursday) ISSUED AT 251 PM CDT WED JUN 18 2014 A minor upper level trough is currently moving through western Kansas, with the stronger dynamics centered off to the north of our CWA. There is a cold front in the vicinity from Hays to north of Syracuse in Hamilton County as of 20z. A dry-line has formed and was from approximately Liberal to Garden City to Hill City at 20z. There was a lower level wave which moved up from the Texas Panhandle earlier this afternoon, which shoved the dry-line northeastward into the cold front, causing the cold front to bow northward in the Ness City/Hays area. This dry-line intrusion into the cold front also slowed the progress of the front to the southeast. A fairly good amount of mid to high level clouds covered most of the CWA at 20z, and a single storm formed near Scott City between 19Z and 20Z. The short term models of the RUC, HRRR and ARW all backed off on a solid line of storms forming along the dry-line this afternoon, but rather a patchy line of storms. There will still probably be a few isolated severe storms with quarter size hail, but do not think the severe storms will be widespread or very big hail (quarters). Will monitor SPC for a Watch. Overnight, the precipitation band from this afternoon should move east, with another surface low moving up from Oklahoma into the P28 area. The aforementioned front will progress southeast through our CWA and be near a Pratt to Coldwater line by 12Z in the morning. Therefore, with greater moisture available in the southeast zones, will increase Pops there toward 12Z, and then spread the Pops back to the northwest during the day Thursday. SPC`s Day2 outlook has about our southeast 1/3rd of the CWA in a slight risk. We will be cooler in the afternoon, with the cold front south of us. Have to agree with SPC`s assessment though, with the NAM model showing 3700 J/Kg of MuCape in our eastern zones, and 24 to 27Kts of bulk shear in that same zone Tuesday at 21Z. There will likely be some more severe storms, again with Quarters to a little larger hail. The TOR threat looks minimal, but some 60kt winds could easily mix down. As for Max/Min temperatures, I did not change anything. Lows tonight will be elevated in the 60F (NW) to 72F (SE) range. On Thursday, it will be cooler with maximum temperatures ranging from the mid 80s north of I-70 and upper 80s down south along the Oklahoma border. .LONG TERM...(Thursday through Tuesday) ISSUED AT 228 AM CDT WED JUN 18 2014 Medium range models indicate a negatively tilted upper level trough of low pressure lifting northeast across the Northern Plains Thursday setting up precip chances from the Upper Midwest southwest into eastern and portions of central Kansas along an attendant frontal boundary. By Thursday afternoon, the GFS/ECMWF show a narrow +70kt upper level jet lifting northeast across central and western Kansas while deep low/mid level moisture pools across south central Kansas ahead of the near stationary frontal boundary. As lapse rates steepen and capping weakens through late Thursday afternoon, thunderstorms are very likely to develop in the vicinity of the frontal boundary, affecting central and possibly eastern portions of southwest Kansas. The focus for thunderstorms will shift northward overnight as the frontal boundary, and an associated surface low in southwest Kansas, begins to lift back to the north as a warm front. The potential for severe storms exists with favorable vertical shear profiles, CAPE values in excess of 3000 J/KG, and very steep lapse rates along and south of the frontal boundary. Large hail and damaging winds will be the primary threat with an isolated tornado not out of the question. The flow aloft is then expected to become weaker while becoming more westerly across the Western High Plains through the weekend. Even with ample low/mid level moisture present, this will limit the chances for more significant rainfall through the weekend. Slightly cooler temperatures are expected Thursday as a cold front pushes through western Kansas before stalling out in the vicinity of south central Kansas near the Oklahoma border. Cooler air will filter southward into west central and portions of southwest Kansas limiting highs only up into the 80s(F) Thursday afternoon. Near 90F is still a possibility in south central Kansas depending where the frontal boundary eventually stalls out. Highs back up into the 90s(F) are then likely Friday through the weekend as a low level southerly flow redevelops across western Kansas and persists through at least Sunday. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 1159 AM CDT WED JUN 18 2014 basically, conditions will be VFR through this evening and into the overnight hours. A line of strong storms is expected to develop around 21-22z from west of KHYS south to near KDDC to just east of KLBL and points southward. Cigs will be elevated, at approximately bkn050cb, and vsbys should remain good. If a thunderstorm develops right over a TAF site, such as KDDC, vsby could go down for a short period. The main hazard with these storms this afternoon and evening will be hail to the size of quarters. There is also a chance for storms overnight, mainly in the KHYS and KDDC TAF sites. && .PRELIMINARY POINT TEMPS/POPS... DDC 67 87 63 91 / 20 30 30 20 GCK 65 86 62 92 / 20 10 10 20 EHA 63 87 63 91 / 20 10 10 20 LBL 67 89 64 92 / 20 20 20 20 HYS 68 86 62 91 / 30 20 30 20 P28 72 89 67 91 / 30 50 60 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Burke LONG TERM...JJohnson AVIATION...Burke
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1058 PM MDT TUE JUN 17 2014 .UPDATE... ISSUED AT 948 PM MDT TUE JUN 17 2014 NO MAJOR CHANGES MADE FOR THIS EVENING ALTHOUGH DID ADJUST DEWPOINTS UP CONSIDERABLY IN THE FAR EAST AS DRYLINE BEGINS TO REGRESS SLOWLY WESTWARD. LATEST NAM AND PREVIOUS GFS SHOW A MID-LEVEL SHORT WAVE TROUGH WILL LIFT OUT OF THE MAIN WESTERN U.S. UPPER LOW OVERNIGHT WITH AN ATTENDANT SURFACE LOW MOVING FROM COLORADO INTO NEBRASKA. THIS WILL TEND TO CHANGE SURFACE WINDS BACK TO THE SOUTHWEST BY LATER TONIGHT AND HALT THE WESTWARD PROGRESSION OF HIGHER DEWPOINTS. STILL A BIT OF UNCERTAINTY FOR TOMORROW AS TO WHERE DRYLINE WILL EVENTUALLY END UP WEDNESDAY AFTERNOON. NAM CONTINUES TO INDICATE POSSIBLE STORM DEVELOPMENT ON THE DRYLINE IN OUR EASTERN COUNTIES DURING THE AFTERNOON AND THEN ANOTHER SHOT AT STORMS MOVING EAST OUT OF COLORADO ASSOCIATED WITH THE UPPER TROUGH DURING THE EVENING. FORECAST CAPE DOESNT LOOK ALL THAT IMPRESSIVE RIGHT NOW FOR MAJOR SEVERE WITH THE EVENING STORMS. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 135 PM MDT TUE JUN 17 2014 LATEST WV IMAGERY AND RAP ANALYSIS SHOW SW FLOW CONTINUING ACROSS THE PLAINS WITH A LARGE CLOSED UPPER LOW OVER IDAHO. VERY DRY AIR CONTINUES TO ADVECT NORTHEAST WITHIN THE FLOW ALOFT INTO THE PLAINS WITH MONSOONAL SHOWERS/THUNDERSTORMS OVER THE HIGHER TERRAIN IN THE SOUTHERN ROCKIES. SURFACE LOW PRESSURE IS CURRENTLY IN PLACE OVER OUR CWA WITH THE STRONGEST PRESSURE GRADIENT WELL EAST OF OUR AREA. A DRY LINE IS ALSO EXTENDS FROM JUST EAST OF OBERLIN KANSAS AND OVER SOUTHWEST KANSAS. FOR THIS AFTERNOON AND EVENING...WHILE SHORT RANGE GUIDANCE IS SHOWING ISOLATED THUNDERSTORM ACTIVITY DEVELOP OVER THE NE PANHANDLE...A VERY DEEP/DRY AIR MASS IN PLACE OVER OUR CWA AND A TREND TOWARDS LOW TD VALUES MIXING NORTH SHOULD PRECLUDE ANY THUNDERSTORM CHANCES. IT STILL LOOKS LIKE WE COULD HAVE A PERIOD OF GUSTY WINDS THIS AFTERNOON BASED ON SHORT RANGE GUIDANCE...THIS DOESNT LOOK LIKE IT WILL BE WIDESPREAD AND SURFACE PATTERN/GRADIENT IS FAIRLY WEAK OVER OUR CWA. RH VALUES HAVE DECREASED SIGNIFICANTLY HOWEVER WITH FUELS STILL QUESTIONABLE AND WINDS MARGINAL NO RED FLAG WARNING IS PLANNED THIS AFTERNOON. WEDNESDAY...WHILE STILL ABOVE NORMAL HIGH TEMPERATURES SHOULD BE COOLER THAN THE LAST FEW DAYS AS THE AIR MASS ALOFT BEGINS TO CHANGE WITH APPROACHING UPPER TROUGH AND APPROACHING COLD FRONT. WE COULD START TO SEE ISOLATED TO WIDELY SCATTERED THUNDERSTORMS DEVELOPING ALONG A CONVERGENCE ZONE IN OUR EASTERN CWA BY LATE AFTERNOON WITH BETTER COVERAGE AFTER 00Z (7PM CDT). SEVERE THREAT WILL BE LIMITED WED AFTERNOON DUE TO QUESTIONABLE THUNDERSTORM COVERAGE AND LIMITED SHEER. HOWEVER...DEPENDING ON THE LOCATION OF TROUGH AXIS WE COULD SEE MODERATE INSTABILITY AND STEEP LAPSE RATES IN PLACE OVER THE EASTERN CWA THAT COULD SUPPORT AN ISOLATED HAIL/DAMAGING WIND THREAT THROUGH WED AFTERNOON. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 247 PM MDT TUE JUN 17 2014 WEDNESDAY EVENING AN UPPER LEVEL SHORT WAVE TROUGH WILL MOVE OVER THE TRI-STATE AREA AHEAD OF THE MAIN TROUGH WHICH WILL MOVE THROUGH DURING THE EVENING/OVERNIGHT HOURS. AS THE MAIN TROUGH MOVES THROUGH...700-300MB FRONTOGENESIS INCREASES OVER THE NORTHERN HALF OF THE AREA. LOW LEVEL MIXING RATIOS...SPECIFICALLY THOSE AT 750MB...INCREASE AHEAD OF THE MAIN TROUGH AS THE TROUGH MOVES THROUGH. AT THE SURFACE THE DRY LINE OVER NORTON AND GRAHAM COUNTIES WILL MOVE BACK WEST ONE OR TWO TIERS OF COUNTIES AS THE SURFACE LOW OVER EASTERN COLORADO DEEPENS. LOW LEVEL MOISTURE WILL ALSO INCREASE OVER THE EASTERN PART OF THE AREA EAST OF RETREATING DRY LINE. IN ADDITION A COLD FRONT WILL BEGIN TO ADVANCE SOUTHEAST ACROSS THE AREA AS THE SURFACE LOW DEEPENS. AS IT MOVES SOUTHEAST RAPID PRESSURE RISES WILL ACCOMPANY THE FRONT AND THE LOW LEVEL JET WILL STRENGTHEN TO NEAR 50 KTS JUST BEHIND THE FRONTAL BOUNDARY. WINDS WILL LIKELY GUST TO 45 MPH BEHIND THE FRONT. DURING THE OVERNIGHT HOURS THE ISALLOBARIC TREND DECLINES SO WINDS SHOULD NOT BE AS STRONG AS THE FRONT CONTINUES TO MOVE THROUGH...EXITING THE AREA AROUND SUNRISE. MEANWHILE THE MAIN UPPER LEVEL TROUGH WILL DEEPEN OVER THE AREA AROUND MIDNIGHT. AHEAD OF IT TEMPERATURE LAPSE RATES ABOVE 850 TO 750 MB OR SO STEEPEN. THE ADDED EFFECT OF INCREASED LOW LEVEL MIXING RATIOS WILL CREATE ELEVATED CAPE OF 1000-2500 J/KG...WITH THE HIGHEST CAPE OVER FAR EASTERN NORTON AND GRAHAM COUNTIES. 0-6KM BULK SHEAR IS AROUND 50KTS SO SEVERE THUNDERSTORMS WILL BE LIKELY. TRIED TO HIGHLIGHT THE MOST LIKELY TIME/LOCATION OF THE SEVERE STORMS IN THE FORECAST. THIS SETUP IS SIMILAR TO SATURDAY EVENING AS FAR AS A SEVERE WIND POTENTIAL WITH STORMS FORMING UPSTREAM OF A COLD FRONT WITH STRONG ISALLOBARIC TRENDS. WOULD NOT BE SURPRISED IF STORMS MERGE INTO A SQUALL LINE BEHIND THE FRONT AND IF HIGH WINDS DEVELOP BEHIND THE STORMS SIMILAR TO SATURDAY NIGHT. TOWARD SUNRISE THE UPPER LEVEL TROUGH MOVES NORTHEAST OF THE AREA WITH DRIER MORE STABLE AIR FOLLOWING THE COLD FRONT IN FROM THE WEST. THURSDAY WILL BE COOLER AND DRY DUE TO A CAPPED ENVIRONMENT. THURSDAY LATE AFTERNOON/EVENING A WEAKER 500MB SHORT WAVE TROUGH DEVELOPS OVER THE COLORADO BORDER. THE DRY LINE/COLD FRONT WILL RETREAT BACK INTO THE FAR SOUTHEAST PART OF THE AREA AS THE LEE TROUGH OVER SOUTHEAST COLORADO DEEPENS. THIS WILL ALLOW LOW LEVEL MIXING RATIOS TO INCREASE EAST OF THE SURFACE BOUNDARY AND ALLOW ELEVATED CAPE TO DEVELOP AHEAD OF THE 500MB TROUGH. AS A RESULT WILL HAVE SOME LOW RAINFALL CHANCES FOR STORMS AHEAD OF THE TROUGH. AS THE NIGHT PROGRESSES THE SURFACE BOUNDARY WILL MOVE NORTH FOLLOWING THE RETREATING UPPER LEVEL TROUGH. DUE TO SOUNDINGS NOT LOOKING VERY SUITABLE FOR MORE WIDESPREAD STORM COVERAGE...WILL KEEP PRECIP. CHANCES FAIRLY LOW DESPITE ELEVATED CAPE OF 1000-2000J/KG. FRIDAY THROUGH TUESDAY WILL CONTINUE TO BE ACTIVE AS THE CLOSED LOW OVER THE NORTHERN CONUS SLOWLY PLODS EAST WITH NUMEROUS SMALLER TROUGHS SOUTH OF IT MOVING OVER THE TRI-STATE AREA. THE BEST CHANCE FOR RAINFALL WILL BE SUNDAY NIGHT INTO MONDAY WHEN A DEEPER UPPER LEVEL TROUGH MOVES OVER THE AREA. GEFS MEMBERS HAVE HIGH CHANCES FOR RAINFALL FOR THAT NIGHT WHICH ADDS CONFIDENCE THAT THE AREA WILL RECEIVE RAINFALL. FAIRLY GOOD CHANCES FOR RAINFALL CONTINUE THROUGH MONDAY NIGHT AS SHORT WAVE TROUGHS CONTINUE TO MOVE OVER THE AREA. SINCE THESE SMALLER SCALE TROUGHS ARE TIED TO THE EASTWARD PROGRESS OF THE CLOSED LOW OVER THE NORTHERN CONUS...WOULD NOT BE SURPRISED IF MODELS PUSH THE HIGHER RAINFALL CHANCES AHEAD A DAY OR TWO BY THE TIME NEXT WEEK ARRIVES SINCE MODELS TEND TO MOVE CLOSED LOWS TOO FAST. TEMPERATURES THROUGH THE PERIOD WILL BE AROUND 10 DEGREES ABOVE NORMAL FRIDAY THEN COOL TO NEAR NORMAL SUNDAY THROUGH TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1055 PM MDT TUE JUN 17 2014 VFR AT BOTH TERMINALS THROUGH THE TAF PERIOD. SURFACE LOW OVER COLORADO WILL MOVE TO NEBRASKA OVERNIGHT GRADUALLY SHIFTING WINDS TO SOUTHWEST. A WEAK COLD FRONT WILL MOVE THROUGH TERMINALS WEDNESDAY MORNING TEMPORARILY CHANGING WIND DIRECTION TO NORTHWEST UNTIL LATE AFTERNOON. THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER COLORADO AND MOVE INTO VCNTY KGLD/KMCK BY EARLY EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...DLF SHORT TERM...DR LONG TERM...JTL AVIATION...DLF
AREA FORECAST DISCUSSION
NWS JACKSON KY
255 PM EDT WED JUN 18 2014 .UPDATE... ISSUED AT 145 PM EDT WED JUN 18 2014 A FEW STRONGER STORMS DEVELOPED QUICKLY OVER THE FAR EASTERN PART OF KENTUCKY EARLIER IN THE AFTERNOON. THESE ARE NOW WANING WITH MORE ISOLATED SHOWERS AND STRAY STORMS...BUILT ON THE ORIGINAL STORMS/S OUTFLOW BOUNDARIES...FOUND ACROSS THE REST OF THE CWA AND INTO CENTRAL KENTUCKY. HAVE UPDATED THE GRIDS TO REFLECT THIS... HITTING THE FAR EAST WITH THE HIGHEST POPS AND SKY COVER. OTHERWISE...MADE SOME TWEAKS TO TEMPS TO REFLECT THE LATEST OBS AND TRENDS...CAPTURING THE...OH SO TEMPORARY...COOLING EFFECT OF THE CONVECTION IN THE EAST. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. UPDATE ISSUED AT 1035 AM EDT WED JUN 18 2014 14Z SFC ANALYSIS SHOWS HIGH PRESSURE OFF TO THE SOUTHEAST OF KENTUCKY WITH A PERSISTENT AND BROAD AREA OF LOW PRESSURE OVER THE PLAINS. FROM THIS LOW...A QUASI-STATIONARY BOUNDARY EXISTS ACROSS THE SOUTHERN TIER OF THE GREAT LAKES SERVING AS A GUIDE PATH FOR PERIODIC CLUSTERS OF SEMI-ORGANIZED STORMS. THAT SHOULD BE THE CASE TODAY...AS WELL. CLOSER TO HOME...THE HIGH PRESSURE SOUTH OF THE FRONT IS FAIRLY WEAK...ALONG WITH THE RIDGE ALOFT. THIS HAS HAD PROBLEMS KEEPING THE AREA BLEMISH FREE THROUGH PEAK HEATING THE PAST COUPLE OF DAYS AND TODAY SHOULD BE NO DIFFERENT. IN FACT...DUE TO THE CONTINUED FLOW OF WARM...MOIST...AND UNSTABLE AIR INTO THIS PART OF THE STATE DO EXPECT TO SEE A LITTLE BIT MORE COVERAGE OF ANY ACTIVITY LATE THIS AFTERNOON. THE HRRR SUPPORTS THIS...ALBEIT A BIT GUNG-HO WHEN COMPARED TO PERSISTENCE AND THE NAM12...AND AS OTHER COARSER RESOLUTION MODELS. NEVERTHELESS...THE CONDITIONS APPEAR TO WARRANT THE INTRODUCTION OF ISOLATED POPS FOR THE LATTER PART OF THE AFTERNOON. HAVE ADDED THESE TO THE GRIDS AND UPDATED THE ZONES/HWO TO CONVEY THE CONCERN. ALSO FINE TUNED TEMPERATURES...DEWPOINTS...AND SKY COVER THROUGH THE NEXT SEVERAL HOURS PER THE LATEST OBS... TRENDS...AND GUIDANCE. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 229 AM EDT WED JUN 18 2014 ANOTHER HOT AND HUMID DAY IS IN STORE FOR EASTERN KENTUCKY. THE HIGH PRESSURE REMAINS FIRMLY IN CONTROL. THE QUASI-STATIONARY FRONT DRAPED ACROSS THE GREAT LAKES WILL BEGIN TO MOVE A LITTLE TO THE SOUTH. THIS WILL MOVE THE CONVECTION TO THE SOUTH AS WELL. THE BIG QUESTION IS THE TIMING OF THIS FRONT AND WHEN THE PRECIPITATION WILL FINALLY BE ABLE TO MOVE INTO EASTERN KENTUCKY. THE MODELS HAVE CONSISTENTLY BEEN TOO QUICK TO BREAK DOWN THE RIDGING AND ALLOW THE SYSTEM TO MOVE SOUTH. THIS BEING SAID...THE LEADING EDGE MAY BE MOVING INTO THE NORTHERN PORTION OF THE AREA TONIGHT WITH SOME ISOLATED TO SCATTERED THUNDERSTORMS AND THEN ACROSS ALL OF EASTERN KENTUCKY ON THURSDAY. STILL HAVE SOME CONCERN THAT ANY THUNDERSTORMS THAT DEVELOP COULD BE STRONG DUE TO THE INSTABILITY AND THE POTENTIAL ENERGY CREATED BY A COMBINATION OF THE INSTABILITY AND MOISTURE. THE LIFTED INDEX THIS EVENING IS FORECAST TO BE AROUND -6 WITH 3000 TO 4000 JOULES OF CONVECTIVE AVAILABLE POTENTIAL ENERGY (CAPE). TONIGHT...THERE WILL BE A WEAK SHORT WAVE MOVING ACROSS THE AREA. THIS MAY PROVIDE THE NECESSARY TRIGGER TO GET THE CONVECTION GOING. ON THURSDAY...THE MODELS ARE SHOWING A LOT MORE MOISTURE ALOFT MOVING INTO THE AREA WITH PRECIPITABLE WATER VALUES AROUND 1.6 INCHES. THIS COULD ALLOW FOR SOME SOAKERS...ESPECIALLY FOR ANY CELLS THAT TRAIN. THE O-6 KM WINDS ARE ONLY FORECAST TO BE AROUND 11 MPH. WITH THE SLOW MOVING CELLS...THE STORMS WILL BE ABLE TO DUMP MORE WATER AND THIS COULD CAUSE SOME OF THE DITCHES AND LOW WATER CROSSING TO BE RUNNING FULL. EXPECT ANOTHER UNCOMFORTABLE DAY WITH NEAR RECORD TEMPERATURES. THE REPEATED HOT DAYS AND FAIRLY WARM EVENINGS...COULD START TO STRESS THE ELDERLY AND THE INFIRM AS WELL AS LIVESTOCK AND PETS. SOME EXTRA CARE SHOULD BE TAKEN TO PROVIDE ADEQUATE HYDRATION AND COOLING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 255 PM EDT WED JUN 18 2014 THE UPPER LEVEL RIDGING WHICH HAS BROUGHT US THE RECENT HOT WEATHER WILL BE SHIFTING OFF TO THE SOUTHWEST DURING THE LONG TERM PERIOD OF THE FORECAST. DESPITE THIS EXPECT TEMPERATURES TO REMAIN ABOVE NORMAL. HOWEVER THE CHANCES FOR PRECIPITATION WILL BE GREATER THAN THEY HAVE BEEN RECENTLY AS WEAK DISTURBANCES MOVE ACROSS THE REGION FROM THE NORTHWEST. A WEAK COLD FRONT WILL PASS THROUGH THE AREA EARLY SATURDAY WITH THE BEST CHANCE OF RAIN FRIDAY INTO EARLY SATURDAY. BOTH THE GFS AND NAM FORECAST PRECIPITABLE WATER 1.80 TO OVER 1.95 INCHES AT 00Z ON SATURDAY...OR AROUND OR POSSIBLY GREATER THAN THE 99TH PERCENTILE. THIS...COMBINED WITH STORM MOTION FORECAST TO BE 5 TO 15 KNOTS COULD LEAD TO LOCALLY HEAVY RAIN FRIDAY INTO FRIDAY NIGHT...AND ISOLATED FLOODING. HAVE MENTIONED THIS POSSIBILITY IN THE LATEST HAZARDOUS WEATHER OUTLOOK. THE FRONT SHOULD GET FAR ENOUGH SOUTH THAT RAIN CHANCES WILL DECREASE OVER THE WEEKEND BUT STILL NEED TO BE MENTIONED IN THE FORECAST. WHILE THERE IS DECENT MODEL AGREEMENT TO START THE LONG TERM PERIOD THERE ARE CONSIDERABLE DIFFERENCES NEXT WEEK...BUT NOT ANY THAT CHANGE THE OVERALL FORECAST OF DAILY SHOWER AND THUNDERSTORM CHANCES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 210 PM EDT WED JUN 18 2014 STILL SOME UNCERTAINTY WITH THE EVOLUTION OF STORMS THROUGH THE REST OF THE AFTERNOON AND INTO THE EVENING...THOUGH THEY SHOULD BE FAR FLUNG ENOUGH TO LIMIT MENTION TO JUST VCTS IN THE TAFS. LATER TONIGHT...A BETTER THREAT OF CONVECTION LIKELY DEVELOPS OVER THE NORTHERN PARTS OF THE CWA...POTENTIALLY IMPACTING THE SOUTH WITH TIME INTO THURSDAY MORNING. HAVE GONE WITH A VCTS RENEWAL TOWARDS 12Z AT ALL SITES CONTINUING THROUGH THE MORNING THURSDAY. FOR THE JKL AND SJS LOCATIONS DID GO WITH A TEMPO STRADDLING 12Z FOR BETTER CHANCES OF THUNDERSTORMS AND AVN WX IMPACTS...PREDOMINANTLY IN THE MVFR RANGE. OUTSIDE OF ANY THUNDERSTORMS WINDS WILL BE LIGHT AND VARIABLE AT NIGHT AND FROM THE SOUTHWEST AT 5 TO 10 KTS DURING THE DAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JJ LONG TERM...SBH AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
210 PM EDT WED JUN 18 2014 .UPDATE... ISSUED AT 145 PM EDT WED JUN 18 2014 A FEW STRONGER STORMS DEVELOPED QUICKLY OVER THE FAR EASTERN PART OF KENTUCKY EARLIER IN THE AFTERNOON. THESE ARE NOW WANING WITH MORE ISOLATED SHOWERS AND STRAY STORMS...BUILT ON THE ORIGINAL STORMS/S OUTFLOW BOUNDARIES...FOUND ACROSS THE REST OF THE CWA AND INTO CENTRAL KENTUCKY. HAVE UPDATED THE GRIDS TO REFLECT THIS... HITTING THE FAR EAST WITH THE HIGHEST POPS AND SKY COVER. OTHERWISE...MADE SOME TWEAKS TO TEMPS TO REFLECT THE LATEST OBS AND TRENDS...CAPTURING THE...OH SO TEMPORARY...COOLING EFFECT OF THE CONVECTION IN THE EAST. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. UPDATE ISSUED AT 1035 AM EDT WED JUN 18 2014 14Z SFC ANALYSIS SHOWS HIGH PRESSURE OFF TO THE SOUTHEAST OF KENTUCKY WITH A PERSISTENT AND BROAD AREA OF LOW PRESSURE OVER THE PLAINS. FROM THIS LOW...A QUASI-STATIONARY BOUNDARY EXISTS ACROSS THE SOUTHERN TIER OF THE GREAT LAKES SERVING AS A GUIDE PATH FOR PERIODIC CLUSTERS OF SEMI-ORGANIZED STORMS. THAT SHOULD BE THE CASE TODAY...AS WELL. CLOSER TO HOME...THE HIGH PRESSURE SOUTH OF THE FRONT IS FAIRLY WEAK...ALONG WITH THE RIDGE ALOFT. THIS HAS HAD PROBLEMS KEEPING THE AREA BLEMISH FREE THROUGH PEAK HEATING THE PAST COUPLE OF DAYS AND TODAY SHOULD BE NO DIFFERENT. IN FACT...DUE TO THE CONTINUED FLOW OF WARM...MOIST...AND UNSTABLE AIR INTO THIS PART OF THE STATE DO EXPECT TO SEE A LITTLE BIT MORE COVERAGE OF ANY ACTIVITY LATE THIS AFTERNOON. THE HRRR SUPPORTS THIS...ALBEIT A BIT GUNG-HO WHEN COMPARED TO PERSISTENCE AND THE NAM12...AND AS OTHER COARSER RESOLUTION MODELS. NEVERTHELESS...THE CONDITIONS APPEAR TO WARRANT THE INTRODUCTION OF ISOLATED POPS FOR THE LATTER PART OF THE AFTERNOON. HAVE ADDED THESE TO THE GRIDS AND UPDATED THE ZONES/HWO TO CONVEY THE CONCERN. ALSO FINE TUNED TEMPERATURES...DEWPOINTS...AND SKY COVER THROUGH THE NEXT SEVERAL HOURS PER THE LATEST OBS... TRENDS...AND GUIDANCE. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 229 AM EDT WED JUN 18 2014 ANOTHER HOT AND HUMID DAY IS IN STORE FOR EASTERN KENTUCKY. THE HIGH PRESSURE REMAINS FIRMLY IN CONTROL. THE QUASI-STATIONARY FRONT DRAPED ACROSS THE GREAT LAKES WILL BEGIN TO MOVE A LITTLE TO THE SOUTH. THIS WILL MOVE THE CONVECTION TO THE SOUTH AS WELL. THE BIG QUESTION IS THE TIMING OF THIS FRONT AND WHEN THE PRECIPITATION WILL FINALLY BE ABLE TO MOVE INTO EASTERN KENTUCKY. THE MODELS HAVE CONSISTENTLY BEEN TOO QUICK TO BREAK DOWN THE RIDGING AND ALLOW THE SYSTEM TO MOVE SOUTH. THIS BEING SAID...THE LEADING EDGE MAY BE MOVING INTO THE NORTHERN PORTION OF THE AREA TONIGHT WITH SOME ISOLATED TO SCATTERED THUNDERSTORMS AND THEN ACROSS ALL OF EASTERN KENTUCKY ON THURSDAY. STILL HAVE SOME CONCERN THAT ANY THUNDERSTORMS THAT DEVELOP COULD BE STRONG DUE TO THE INSTABILITY AND THE POTENTIAL ENERGY CREATED BY A COMBINATION OF THE INSTABILITY AND MOISTURE. THE LIFTED INDEX THIS EVENING IS FORECAST TO BE AROUND -6 WITH 3000 TO 4000 JOULES OF CONVECTIVE AVAILABLE POTENTIAL ENERGY (CAPE). TONIGHT...THERE WILL BE A WEAK SHORT WAVE MOVING ACROSS THE AREA. THIS MAY PROVIDE THE NECESSARY TRIGGER TO GET THE CONVECTION GOING. ON THURSDAY...THE MODELS ARE SHOWING A LOT MORE MOISTURE ALOFT MOVING INTO THE AREA WITH PRECIPITABLE WATER VALUES AROUND 1.6 INCHES. THIS COULD ALLOW FOR SOME SOAKERS...ESPECIALLY FOR ANY CELLS THAT TRAIN. THE O-6 KM WINDS ARE ONLY FORECAST TO BE AROUND 11 MPH. WITH THE SLOW MOVING CELLS...THE STORMS WILL BE ABLE TO DUMP MORE WATER AND THIS COULD CAUSE SOME OF THE DITCHES AND LOW WATER CROSSING TO BE RUNNING FULL. EXPECT ANOTHER UNCOMFORTABLE DAY WITH NEAR RECORD TEMPERATURES. THE REPEATED HOT DAYS AND FAIRLY WARM EVENINGS...COULD START TO STRESS THE ELDERLY AND THE INFIRM AS WELL AS LIVESTOCK AND PETS. SOME EXTRA CARE SHOULD BE TAKEN TO PROVIDE ADEQUATE HYDRATION AND COOLING. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 302 AM EDT WED JUN 18 2014 MORE OF THE SAME IN THE EXTENDED THIS GO ROUND. THE MODELS ARE STILL HAVING A VERY DIFFICULT TIME CONVERGING ON A COMMON SOLUTION AS FAR AS THE OVERALL LARGE SCALE WEATHER PATTERN AND THE TIMING OF WEATHER SYSTEM PASSAGE ACROSS THE CONUS FROM THURSDAY NIGHT ONWARD. WITH THAT BEING SAID...WENT WITH A SLIGHTLY MODIFIED VERSION OF THE STANDARD LONG TERM GRID POPULATION PROCEDURE...WITH THE DATA BEING BLENDED WITH WHAT I FELT WAS THE MORE REASONABLE GFS MODEL GUIDANCE. THERE WILL BE A CHANCE OF SHOWERS EACH DAY IN THE EXTENDED...WITH THE HIGHER RAIN CHANCES GENERALLY OCCURRING DURING THE AFTERNOON AND EVENING HOURS DURING PEAK HEATING. THIRTY TO FIFTY PERCENT PRECIPITATION PROBABILITIES WERE USED ACROSS THE BOARD TO REFLECT THIS. A COUPLE OF FRONTAL BOUNDARIES...AND FRONTAL WAVES MOVING ALONG THEM...WILL BE THE TRIGGERING MECHANISMS FOR SHOWERS AND STORMS. THE EXTENDED PERIOD WILL STILL BE QUITE WARM...WITH ABOVE NORMAL TEMPERATURES...BUT NOT NEARLY AS WARM AS IT HAS BEEN THE PAST COUPLE OF DAYS ACROSS EASTERN KENTUCKY. LOOK FOR HIGHS MOSTLY IN THE MID 80S...WITH SLIGHTLY COOLER VALUES TOWARD THE END OF THE PERIOD AS SHOWERS AND STORMS BECOME MORE WIDESPREAD AS A FRONTAL BOUNDARY MEANDERS ABOUT THE REGION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 210 PM EDT WED JUN 18 2014 STILL SOME UNCERTAINTY WITH THE EVOLUTION OF STORMS THROUGH THE REST OF THE AFTERNOON AND INTO THE EVENING...THOUGH THEY SHOULD BE FAR FLUNG ENOUGH TO LIMIT MENTION TO JUST VCTS IN THE TAFS. LATER TONIGHT...A BETTER THREAT OF CONVECTION LIKELY DEVELOPS OVER THE NORTHERN PARTS OF THE CWA...POTENTIALLY IMPACTING THE SOUTH WITH TIME INTO THURSDAY MORNING. HAVE GONE WITH A VCTS RENEWAL TOWARDS 12Z AT ALL SITES CONTINUING THROUGH THE MORNING THURSDAY. FOR THE JKL AND SJS LOCATIONS DID GO WITH A TEMPO STRADDLING 12Z FOR BETTER CHANCES OF THUNDERSTORMS AND AVN WX IMPACTS...PREDOMINANTLY IN THE MVFR RANGE. OUTSIDE OF ANY THUNDERSTORMS WINDS WILL BE LIGHT AND VARIABLE AT NIGHT AND FROM THE SOUTHWEST AT 5 TO 10 KTS DURING THE DAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JJ LONG TERM...AR AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1035 AM EDT WED JUN 18 2014 .UPDATE... ISSUED AT 1035 AM EDT WED JUN 18 2014 14Z SFC ANALYSIS SHOWS HIGH PRESSURE OFF TO THE SOUTHEAST OF KENTUCKY WITH A PERSISTENT AND BROAD AREA OF LOW PRESSURE OVER THE PLAINS. FROM THIS LOW...A QUASI-STATIONARY BOUNDARY EXISTS ACROSS THE SOUTHERN TIER OF THE GREAT LAKES SERVING AS A GUIDE PATH FOR PERIODIC CLUSTERS OF SEMI-ORGANIZED STORMS. THAT SHOULD BE THE CASE TODAY...AS WELL. CLOSER TO HOME...THE HIGH PRESSURE SOUTH OF THE FRONT IS FAIRLY WEAK...ALONG WITH THE RIDGE ALOFT. THIS HAS HAD PROBLEMS KEEPING THE AREA BLEMISH FREE THROUGH PEAK HEATING THE PAST COUPLE OF DAYS AND TODAY SHOULD BE NO DIFFERENT. IN FACT...DUE TO THE CONTINUED FLOW OF WARM...MOIST...AND UNSTABLE AIR INTO THIS PART OF THE STATE DO EXPECT TO SEE A LITTLE BIT MORE COVERAGE OF ANY ACTIVITY LATE THIS AFTERNOON. THE HRRR SUPPORTS THIS...ALBEIT A BIT GUNG-HO WHEN COMPARED TO PERSISTENCE AND THE NAM12...AND AS OTHER COARSER RESOLUTION MODELS. NEVERTHELESS...THE CONDITIONS APPEAR TO WARRANT THE INTRODUCTION OF ISOLATED POPS FOR THE LATTER PART OF THE AFTERNOON. HAVE ADDED THESE TO THE GRIDS AND UPDATED THE ZONES/HWO TO CONVEY THE CONCERN. ALSO FINE TUNED TEMPERATURES...DEWPOINTS...AND SKY COVER THROUGH THE NEXT SEVERAL HOURS PER THE LATEST OBS... TRENDS...AND GUIDANCE. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 229 AM EDT WED JUN 18 2014 ANOTHER HOT AND HUMID DAY IS IN STORE FOR EASTERN KENTUCKY. THE HIGH PRESSURE REMAINS FIRMLY IN CONTROL. THE QUASI-STATIONARY FRONT DRAPED ACROSS THE GREAT LAKES WILL BEGIN TO MOVE A LITTLE TO THE SOUTH. THIS WILL MOVE THE CONVECTION TO THE SOUTH AS WELL. THE BIG QUESTION IS THE TIMING OF THIS FRONT AND WHEN THE PRECIPITATION WILL FINALLY BE ABLE TO MOVE INTO EASTERN KENTUCKY. THE MODELS HAVE CONSISTENTLY BEEN TOO QUICK TO BREAK DOWN THE RIDGING AND ALLOW THE SYSTEM TO MOVE SOUTH. THIS BEING SAID...THE LEADING EDGE MAY BE MOVING INTO THE NORTHERN PORTION OF THE AREA TONIGHT WITH SOME ISOLATED TO SCATTERED THUNDERSTORMS AND THEN ACROSS ALL OF EASTERN KENTUCKY ON THURSDAY. STILL HAVE SOME CONCERN THAT ANY THUNDERSTORMS THAT DEVELOP COULD BE STRONG DUE TO THE INSTABILITY AND THE POTENTIAL ENERGY CREATED BY A COMBINATION OF THE INSTABILITY AND MOISTURE. THE LIFTED INDEX THIS EVENING IS FORECAST TO BE AROUND -6 WITH 3000 TO 4000 JOULES OF CONVECTIVE AVAILABLE POTENTIAL ENERGY (CAPE). TONIGHT...THERE WILL BE A WEAK SHORT WAVE MOVING ACROSS THE AREA. THIS MAY PROVIDE THE NECESSARY TRIGGER TO GET THE CONVECTION GOING. ON THURSDAY...THE MODELS ARE SHOWING A LOT MORE MOISTURE ALOFT MOVING INTO THE AREA WITH PRECIPITABLE WATER VALUES AROUND 1.6 INCHES. THIS COULD ALLOW FOR SOME SOAKERS...ESPECIALLY FOR ANY CELLS THAT TRAIN. THE O-6 KM WINDS ARE ONLY FORECAST TO BE AROUND 11 MPH. WITH THE SLOW MOVING CELLS...THE STORMS WILL BE ABLE TO DUMP MORE WATER AND THIS COULD CAUSE SOME OF THE DITCHES AND LOW WATER CROSSING TO BE RUNNING FULL. EXPECT ANOTHER UNCOMFORTABLE DAY WITH NEAR RECORD TEMPERATURES. THE REPEATED HOT DAYS AND FAIRLY WARM EVENINGS...COULD START TO STRESS THE ELDERLY AND THE INFIRM AS WELL AS LIVESTOCK AND PETS. SOME EXTRA CARE SHOULD BE TAKEN TO PROVIDE ADEQUATE HYDRATION AND COOLING. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 302 AM EDT WED JUN 18 2014 MORE OF THE SAME IN THE EXTENDED THIS GO ROUND. THE MODELS ARE STILL HAVING A VERY DIFFICULT TIME CONVERGING ON A COMMON SOLUTION AS FAR AS THE OVERALL LARGE SCALE WEATHER PATTERN AND THE TIMING OF WEATHER SYSTEM PASSAGE ACROSS THE CONUS FROM THURSDAY NIGHT ONWARD. WITH THAT BEING SAID...WENT WITH A SLIGHTLY MODIFIED VERSION OF THE STANDARD LONG TERM GRID POPULATION PROCEDURE...WITH THE DATA BEING BLENDED WITH WHAT I FELT WAS THE MORE REASONABLE GFS MODEL GUIDANCE. THERE WILL BE A CHANCE OF SHOWERS EACH DAY IN THE EXTENDED...WITH THE HIGHER RAIN CHANCES GENERALLY OCCURRING DURING THE AFTERNOON AND EVENING HOURS DURING PEAK HEATING. THIRTY TO FIFTY PERCENT PRECIPITATION PROBABILITIES WERE USED ACROSS THE BOARD TO REFLECT THIS. A COUPLE OF FRONTAL BOUNDARIES...AND FRONTAL WAVES MOVING ALONG THEM...WILL BE THE TRIGGERING MECHANISMS FOR SHOWERS AND STORMS. THE EXTENDED PERIOD WILL STILL BE QUITE WARM...WITH ABOVE NORMAL TEMPERATURES...BUT NOT NEARLY AS WARM AS IT HAS BEEN THE PAST COUPLE OF DAYS ACROSS EASTERN KENTUCKY. LOOK FOR HIGHS MOSTLY IN THE MID 80S...WITH SLIGHTLY COOLER VALUES TOWARD THE END OF THE PERIOD AS SHOWERS AND STORMS BECOME MORE WIDESPREAD AS A FRONTAL BOUNDARY MEANDERS ABOUT THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 749 AM EDT WED JUN 18 2014 THE PATCHY VALLEY FOG WILL BURN OFF BY 13Z AND THEN FORM AGAIN NEAR DAWN TOMORROW. THE MIST MAY MAKE IT UP TO THE TAF STATIONS AROUND 11Z. SOME ISOLATED CONVECTION IS POSSIBLE TONIGHT...HOWEVER THE EXTENT AND TIMING IS TOO UNSURE TO PUT ANYTHING INTO THE TAF AT THIS TIME. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JJ LONG TERM...AR AVIATION...JJ
AREA FORECAST DISCUSSION
NWS GRAY ME
517 PM EDT WED JUN 18 2014 .SYNOPSIS... A WEAK SECONDARY COLD FRONT WILL MOVE THROUGH TONIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST THURSDAY INTO THE UPCOMING WEEKEND. A COLD FRONT WILL BRING AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... UPDATE... HAVE UPDATED THE GRIDS TO ACCOUNT FOR LINE OF SHOWERS MOVING THROUGH THE WESTERN MOUNTAINS OF MAINE EARLY THIS EVENING...AS WELL AS NORTHERN NH. THERE COULD BE AN ISOLATED THUNDERSTORM IN THIS AREAS OF CONVECTION AS WELL. AS THE SHOWERS HEAD SOUTHEAST...DOWNSLOPING WILL CAUSE THE MOISTURE TO DISSIPATE WITH TIME. THIS HAS BEEN HANDLED WELL BY LATEST HRRR PRODUCTS. ONLY A FEW TWEAKS TO THE REMAINDER OF THE GRIDDED PACKAGE EARLY THIS EVENING. PREV DISC... A WEAK SECONDARY COLD FRONT WILL MOVE THRU THE REGION THIS EVENING WITH HARDLY A NOTICE..OTHER THAN SOME CLDS AND MAYBE A SHWR IN THE MTNS. OTHER DOWNSLOPING AREAS WILL BECOME MOSTLY CLEAR TONIGHT AND THE GUSTY WINDS WILL QUICKLY SUBSIDE AROUND SS. USED THE SUPERBLEND GUID FOR TONIGHT. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... THE NWLY FLOW ALOFT WILL CONTINUE ALLOWING A VERY DRY AND PLEASANT NWLY FLOW TO CONTINUE THURS AND THURS NIGHT. WINDS WILL NOT BE AS GUSTY DURING THE DAY BUT STILL A STEADY NWLY BREEZE AS CANADIAN SFC HIGH PRES SLOWLY BUILDS SEWD INTO THE REGION. ON THURS NIGHT HIGH PRES WILL SETTLE OVER THE AREA WITH CONTINUED PLEASANT CONDS. USED THE SUPERBLEND FOR TEMPS FCST. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... 500 MB BLOCKING TO OUR E WILL KEEP CLOSED LOW MEANDERING AROUND THE MARITIMES FRIDAY THRU THE WEEKEND. THIS WILL KEEP THE CWA MAINLY IN NW FLOW...WHICH SHOULD PROVIDE MAINLY SUNNY SKIES...AND TEMPERATURES RUNNING NEAR NORMAL ON HIGHS...BUT SLIGHTLY COOLER AT NIGHT. SO...ALL IN ALL...A PLEASANT WEEKEND. FRIDAY COULD SEE A BREEZY NW FLOW...WITH GUSTS OF 20-25 MPH...BUT WINDS SHOULD DIMINISH FOR SAT/SUN. THE FLOW ALOFT BECOMES A BIT MORE ZONAL BY MONDAY...WITH PERHAPS A HINT OF RIDGING...WHICH SHOULD WARM THINGS UP A BIT ON MONDAY. MODELS THEN SHOWING A 500 WAVE CROSSES JUST TO OUR N...WHICH COULD BRING A FRONT THROUGH THE REGION TUE OR WED...DEPENDING ON WHICH MODEL YOU LOOK AT...WHICH WILL BE OUR NEXT CHC OF SHRA/TSRA. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... SHORT TERM /THROUGH THURSDAY/...VFR CONDS. LONG TERM...SOME NW WIND GUSTS OF 20-25 KT POSSIBLE ON FRI...OTHERWISE VFR FRI THRU MON. && .MARINE... SHORT TERM...SCA WINDS CONTINUE ATTM SO WILL CONTINUE THE SCA UNTIL 00Z. AFTER SS WINDS WILL QUICKLY BECOME LIGHT FROM THE NW. THE NW WINDS ON THU WILL ONCE INCREASE SOME BUT SHOULD STAY WELL BELOW SCA CRIT. WINDS WILL BECOME LIGHT ONCE AGAIN THU NIGHT. LONG TERM...THE WATERS WILL REMAIN BLO SCA LVLS FRIDAY THRU MONDAY...ALTHOUGH SOME NW GUSTS TO 20 KT WILL BE POSSIBLE ON FRI. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ150- 152-154. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ150- 152-154. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
329 PM EDT WED JUN 18 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN ACROSS THE SOUTHEASTERN STATES THROUGH TONIGHT. A WEAK COLD FRONT WILL MOVE INTO THE REGION FROM THE NORTHWEST ON THURSDAY AND WILL STALL JUST SOUTH OF THE AREA FRIDAY INTO THE WEEKEND. ANOTHER WEAK COLD FRONT APPROACHES THE REGION NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... AS OF 18Z...BOUNDARY OVER THE DC AREA IS FROM OVERNIGHT/MORNING ACTIVITY OVER PA. DEWPOINTS ARE AROUND 70F ALONG THIS BOUNDARY WITH UPR 60S BOTH NORTH (BALTIMORE) AND SOUTH (CHARLOTTESVILLE). WITH TEMPERATURES GENERALLY LOW TO MID 90S...THE HIGHEST HEAT INDICES ARE AROUND 100 DEGREES IN DC...WITH MID TO UPR 90S ELSEWHERE. ISOLATED SHOWER/THUNDERSTORM ACTIVITY WILL CONTINUE ALONG THIS FRONT AS INDICATED FROM THE LATEST FORECAST UPDATE. LACK OF SHEAR WILL MAKE FOR PULSE ACTIVITY. WILL NEED TO CONTINUE WATCHING THE MCS OVER IL/MI WHICH HAS A WEAKER RADAR MOSAIC APPEARANCE...BUT IS STILL PRODUCING COPIOUS LIGHTNING. THERE IS A SEGMENT OVER SRN WV THAT WILL CONTINUE TRACKING EAST TO OUR SWRN ZONES AND OTHER ACTIVITY COULD FORM OVER THE TERRAIN. 15Z HRRR IS SIMILAR TO OTHER RECENT RUNS WITH ORGANIZED ACTIVITY FROM THE MIDWEST DELAYED FOR THE LWX CWA UNTIL LATE TONIGHT/THURSDAY MORNING. TEMPS A FEW LESS DEGREES THURSDAY WITH 18C 850MB TEMPS COMPARED TO 20C TODAY. FURTHERMORE...SHOULD PRECIP BE GOING ON DURING THE DAY...OR CLOUD COVER THICK ENOUGH...MAX TEMPERATURES COULD BE SEVERAL DEGREES LESS (PERHAPS UPR 80S). && .SHORT TERM /THURSDAY NIGHT/... COLD FRONT/BOUNDARY STALLS SOUTH OF THE AREA THURSDAY NIGHT THROUGH FRIDAY WITH A QUIET PERIOD IN AN OTHERWISE ACTIVE SPELL. BRIEF COOL DOWN THAT CONTINUES INTO THE WEEKEND (AS LONG AS THE BOUNDARY STAYS SOUTH). WILL NEED TO LOOK OUT FOR SHORTWAVES RIDING THE BOUNDARY...SUCH AS THE 12Z ECMWF SOLUTION WITH A FRIDAY NIGHT/SATURDAY MORNING WAVE CROSSING THE AREA. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... COMBINED MOIST WARM AIRMASS ALONG WITH A QUASI-STATIONARY BOUNDARY AND WEAK PVA CONTINUES TO SUPPORT A CHANCE OF SHOWERS AND AFTERNOON THUNDERSTORMS THROUGH THE PERIOD. SURFACE LOW PRESSURE CENTER TRACKING EAST ALONG THE BOUNDARY WILL SUPPORT THE ENHANCED DEVELOPMENT OF SHOWERS AND THUNDERSTORMS WEDNESDAY. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... VFR INTO THIS EVENING OUTSIDE OF ISOLATED TSRA MAINLY ALONG A EAST-WEST BOUNDARY ACROSS THE DCA AREA AND FROM THE TERRAIN WEST OF DC METROS. CU FIELD BASED AROUND 5 KFT. ORGANIZED THUNDERSTORM COMPLEX COULD APPROACH THE TERMINALS LATE TONIGHT OR THURSDAY MORNING. FRONTAL BOUNDARY SOUTH OF THE TERMINALS THURSDAY NIGHT AND FRIDAY BEFORE DRIFTING NORTH THIS WEEKEND. && .MARINE... WLY/NWLY FLOW AROUND 10 KT WITH ISOLATED SHOWERS AND THUNDERSTORMS FROM DC TO CENTRAL MD. ORGANIZED THUNDERSTORM SYSTEM POSSIBLE REACHES THE BAY LATE TONIGHT OR THURSDAY MORNING. FRONTAL BOUNDARY SOUTH OF THE WATERS THURSDAY NIGHT INTO THE WEEKEND. NO SCA IN THE OUTLOOK PERIOD. && .CLIMATE... A RECORD HIGH TEMPERATURE WAS REPORTED AT REAGAN NATIONAL AIRPORT YESTERDAY. THE HIGH WAS 97 DEGREES AND THIS SURPASSES THE OLD RECORD OF 95 DEGREES SET IN 1991...1957...AND 1945. MORE RECORD HIGHS ARE POSSIBLE TODAY AT BWI AND DCA. THE LIST BELOW IS THE RECORD HIGHS FOR THE THREE MAJOR AIRPORTS. KBWI: RECORD HIGH: 97 IN 1957. KDCA: RECORD HIGH: 97 IN 1944. KIAD: RECORD HIGH: 94 IN 2007. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ530- 531-538-539. && $$ SYNOPSIS...BAJ NEAR TERM...BAJ SHORT TERM...BAJ LONG TERM...CEM AVIATION...BAJ MARINE...BAJ CLIMATE...BAJ
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1044 AM EDT WED JUN 18 2014 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL REMAIN ACROSS THE WESTERN ATLANTIC AND SOUTHEAST STATES THROUGH TONIGHT. A WEAK COLD FRONT WILL MOVE INTO THE REGION FROM THE NORTHWEST ON THURSDAY AND WILL STALL OVER THE SOUTHERN MID-ATLANTIC FRIDAY INTO THE WEEKEND. ANOTHER WEAK COLD FRONT APPROACHES EARLY NEXT WEEK...CONTINUING AN ACTIVE PATTERN. && .NEAR TERM /THROUGH THURSDAY/... PATTERN THIS MORNING REMAINS A TROUGH OVER NEW ENGLAND...CLOSED LOW OVER THE NRN ROCKIES..AND AN HIGH CENTERED OVER FL WITH A PLUME OF GULF MOISTURE INTO THE UPPER MIDWEST. ONGOING MCS NEAR MILWAUKEE WILL NEED TO BE MONITORED. RECENT HRRR RUNS HAVE SENT THIS ACTIVITY INTO THE NRN MID-ATLANTIC...WHICH MAKES SENSE GIVEN THE POSITION OF THE SFC HIGH OVER GA WITH MAINLY ZONAL FLOW OVER THE ERN CONUS. ONGOING ACTIVITY OVER WRN PA IS DRIFTING SOUTH...AND MAY BE A BOUNDARY CONTRIBUTOR THIS AFTERNOON/EVENING. CURRENT MCS THREAT TIMEFRAME IS OVERNIGHT AND/OR THURSDAY MORNING. EXPECT ISOLATED/WIDELY SCATTERED AIRMASS STORMS THIS AFTERNOON INTO THE EVENING. WLY/SWLY DOWNSLOPING FLOW WILL KEEP DEWPOINTS IN THE MID 60S AND ALLOW TEMPERATURES TO BE EVEN HIGHER THAN YESTERDAY. SEE CLIMATE SECTION BELOW. PREVIOUS... CONFIDENCE INCREASES TONIGHT AS A FRONTAL BOUNDARY THAT HAS BEEN DRAPED ACROSS THE GREAT LAKES EARLIER THIS WEEK MOVES SOUTH. MULTIPLE DISTURBANCES WILL ALSO CROSS THE REGION AND A MCS OR TWO WILL LIKELY MOVE ACROSS THE REGION LATE TONIGHT AND INTO THURSDAY. HIGH AMTS OF INSTABILITY WILL STILL BE IN PLACE AND SHEAR PROFILES WILL INCREASE. DMG WINDS AND LARGE HAIL WILL BE POSSIBLE IN LINE SEGMENTS AND BOW ECHOES. ACTIVITY WILL BE ONGOING THURSDAY MORNING AS THE FRONTAL BOUNDARY MOVES INTO SRN VA. SHOWERS AND THUNDERSTORMS ARE POSSIBLE THURSDAY AND ACTIVITY WILL BE CAPABLE OF GUSTY WINDS AND HEAVY RAIN. THE SEVERITY LEVEL IS IN QUESTION THURSDAY MORNING AND AFTERNOON SINCE ACTIVITY WEDNESDAY NIGHT MAY REDUCE INSTABILITY AMTS. HEAVY RAIN MAY CAUSE SOME LOCALIZED FLOODING ISSUES ESPECIALLY IN AREAS THAT HAVE SEEN HEAVY RAIN FROM THUNDERSTORMS IN THE PAST WEEK. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/... FRONTAL BOUNDARY WILL BE ORIENTED ACROSS THE CWA ROUGHLY FROM WEST TO EAST THURSDAY NIGHT...THEN RE-ORIENTS ITSELF FROM NORTHWEST TO SOUTHEAST DURING THE DAYTIME FRIDAY. CONVECTION IS LIKELY TO BE ONGOING THURSDAY EVENING GIVEN FRONT AND ALSO A SHORTWAVE TRAVELING IN NORTHWEST MID-LEVEL FLOW. SHOULD SEE A DOWNTREND IN CONVECTION OVERNIGHT THURSDAY....BUT WILL CONTINUE LOW POPS ACROSS THE SOUTHWEST CWA AS ANOTHER SHORTWAVE COULD KEEP SOME ACTIVITY GOING INTO THE NIGHT. HIGHEST POPS ON FRIDAY LOOK TO BE ALONG/SOUTHWEST OF THE FRONT WHICH WOULD ALSO COINCIDE WITH THE TRAJECTORY OF UPSTREAM SHORTWAVES. MORE CLOUDS WILL ALSO LIKELY TEMPER TEMPERATURES ON FRIDAY...MOST NOTABLY NORTHEAST OF THE FRONT INTO NORTH CENTRAL MARYLAND. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... FRONT WILL REMAIN STALLED OVER THE MID-ATLANTIC OVER THE WEEKEND WITH MINOR OSCILLATING MOVEMENTS. SHORTWAVES MOVING THROUGH IN NORTHWEST FLOW WILL ALSO CONTINUE TO BRING A CHANCE OF SHOWERS AND THUNDERSTORMS. ONE SHORTWAVE OF INTEREST MAY BE STRONG ENOUGH TO GENERATE A SURFACE LOW REFLECTION. IT/S UNCERTAIN WHETHER THIS WOULD BE FRIDAY NIGHT OR SATURDAY THEREFORE HAVE KEPT POPS IN THE CHANCE CATEGORY BOTH PERIODS FOR NOW BUT AN ENHANCED CHANCE OF CONVECTION MAY OCCUR DURING THIS TIME. IF THE SHORTWAVE IS STRONG ENOUGH THIS COULD PUSH THE FRONT FURTHER SOUTH OF THE CWA. BUT EVEN IF THIS HAPPENS...EXPECT A CONTINUATION OF CHANCE POPS GIVEN PERSISTENT NORTHWEST FLOW ALOFT. IN ADDITION...THAT BOUNDARY WILL EVENTUALLY LIFT BACK NORTH AS A WARM FRONT MAKING IT TOUGH TO RULE OUT CONVECTION ANY DAY IN THE LONG TERM. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS EXPECTED TODAY. WESTERLY WINDS WITH A FEW GUSTS TO 18 KTS POSSIBLE AT IAD-BWI-MTN-DCA-MRB. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY ACROSS THE TERMINALS. ACTIVITY WILL INCREASE IN COVERAGE TONIGHT AND INTO THURSDAY AS A FRONTAL BOUNDARY MOVES ACROSS THE REGION TONIGHT. MVFR/IFR CONDITIONS WILL BE POSSIBLE IN THUNDERSTORMS. OUTLOOK...COLD FRONT STALLS OVER THE AREA THROUGH THE WEEKEND...PROMOTING A CHANCE OF SHOWERS AND THUNDERSTORMS DURING THIS TIME. && .MARINE... SCA FOR WLY GUSTS UP TO 20 KT FOR NRN BAY AS WELL FORECAST TUESDAY EVENING SHIFT. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING. MORE WIDESPREAD COVERAGE IS EXPECTED LATE TONIGHT AND INTO THURSDAY. SOME STORMS WILL PRODUCE GUSTY WINDS LIKELY RESULTING IN SMW ISSUANCE. STALLED BOUNDARY REMAINS THROUGH THE WEEKEND. NO SCA EXPECTED DURING THAT TIME. STRONG GUSTY WINDS WILL BE POSSIBLE IN SCATTERED THUNDERSTORMS THROUGH THE WEEKEND. && .CLIMATE... A RECORD HIGH TEMPERATURE WAS REPORTED AT REAGAN NATIONAL AIRPORT YESTERDAY. THE HIGH WAS 97 DEGREES AND THIS SURPASSES THE OLD RECORD OF 95 DEGREES SET IN 1991...1957...AND 1945. MORE RECORD HIGHS ARE EXPECTED TODAY AT DCA...AND POSSIBLE AT BWI AND IAD. THE LIST BELOW ARE THE RECORD HIGHS FOR THE THREE MAJOR AIRPORTS...KBWI...KDCA...AND KIAD. KBWI: RECORD HIGH: 97 IN 1957. KDCA: RECORD HIGH: 97 IN 1944. KIAD: RECORD HIGH: 94 IN 2007. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ530- 531-538-539. && $$ SYNOPSIS...BAJ/BPP/HAS NEAR TERM...BAJ/HAS SHORT TERM...BPP LONG TERM...BPP AVIATION...BAJ/BPP/HAS MARINE...BAJ/BPP/HAS CLIMATE...BAJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
332 PM EDT WED JUN 18 2014 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/MARINE .SYNOPSIS... ISSUED AT 330 PM EDT WED JUN 18 2014 OCCASIONAL THUNDERSTORMS WILL CONTINUE OVERNIGHT BUT THERE SHOULD BE A BREAK ON THURSDAY INTO THURSDAY NIGHT BEFORE THE STORMS RETURN ON FRIDAY AND OVER THE WEEKEND. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 330 PM EDT WED JUN 18 2014 LINE OF STORMS DEPARTING THE EASTERN FORECAST AREA LATE THIS AFTERNOON WITH A LULL EXPECTED INTO EARLY THIS EVENING. AIRMASS SHOULD GET A CHANCE TO DESTABILIZE BEFORE SUNSET...WHICH ALLOWS NEW STORMS TO FIRE UP AS AN MCV TRACKS ACROSS THE SOUTHERN FORECAST AREA. THIS HAS BEEN INDICATED BY THE HRRR AS WELL AS THE 12Z GFS AND ECMWF. POPS AND QPF SHADED HIGHER ACROSS THE SOUTH. STORMS DIMINISH THURSDAY UNDER SHORT WAVE RIDGING AND PICK UP AGAIN FRIDAY. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 330 PM EDT WED JUN 18 2014 QUASI ZONAL FLOW WILL RESULT IN WEAK UPPER IMPULSES MOVING ACROSS THE UPPER MIDWEST DURING THE PERIOD. ONE OF THOSE WAVES WILL PUSH A WEAK COLD FRONT EAST THROUGH THE GREAT LAKES SUNDAY. THIS FRONTAL BOUNDARY WILL LINGER ACROSS THE CWA FOR SEVERAL DAYS AS LOW PRESSURE IN THE CENTRAL PLAINS SLOWLY MOVES ENE. WE/LL HAVE CHC POPS BEGINNING SUNDAY AND CARRY THAT THROUGH MUCH OF THE REST OF THE PERIOD. GFS AND ECMWF ARE IN REASONABLE AGREEMENT MOVING THE LOW TO ILLINOIS BY WEDNESDAY. THE ECMWF HAS HIGHER QPF VS THE GFS BUT BOTH SHOW SHOWERS. WE/LL LIKELY HAVE TO INCREASE POPS FOR THE MIDDLE OF NEXT WEEK IF THE TREND CONTINUES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 155 PM EDT WED JUN 18 2014 TSRA WILL IMPACT KLAN/KJXN/KBTL/KAZO FOR A COUPLE OF HOURS THIS AFTERNOON. THEN A FEW HOUR BREAK BEFORE MORE STORMS DEVELOP AND AFFECT ALL TAF SITES LATE THIS AFTERNOON AND EARLY EVENING. OVERNIGHT...WINDS WILL BE LIGHT AND CIGS/VSBYS WILL FALL DUE TO ABUNDANT LOW LEVEL MOISTURE. MVFR/IFR EXPECTED AFTER 05Z. && .MARINE... ISSUED AT 317 PM EDT WED JUN 18 2014 SHOWERS AND THUNDERSTORMS...ALONG WITH AREAS OF FOG...WILL PERSIST OVERNIGHT. WINDS AND WAVES WILL BE LOCALLY HIGHER IN AND NEAR THUNDERSTORMS...BUT OTHERWISE REMAIN BLO SMALL CRAFT ADVISORY THE NEXT COUPLE DAYS. && .HYDROLOGY... ISSUED AT 100 PM EDT WED JUN 18 2014 RIVERS ARE RUNNING WELL WITHIN THEIR BANKS AND NEAR NORMAL LEVELS FOR THIS TIME OF YEAR. HOWEVER... THE GRAND AND MUSKEGON RIVERS ARE BEGINNING TO SLOWLY RISE DUE TO THE RAIN FROM TUESDAY AND TODAY. ONLY THE ROGUE RIVER AT ROCKFORD LOOKS LIKE IT MAY RISE TO NEAR BANKFULL... AND THAT WOULD BE TOMORROW. ADDITIONAL RAIN THIS AFTERNOON SHOULD ADD LITTLE ADDITIONAL RISE TO THE RIVERS. THURSDAY MIGHT BE A DRY DAY... BUT ADDITIONAL RAINFALL THURSDAY NIGHT AND FRIDAY COULD BRING MORE POINTS UP TO NEAR BANKFULL. RIVER FLOODING IS NOT EXPECTED. MINOR AREAL FLOODING IS A POSSIBILITY DUE TO THE HEAVY RAIN IN THE THUNDERSTORMS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR MIZ043>045- 050>052-056>059-064>067-071>074. LM...NONE. && $$ SYNOPSIS...OSTUNO SHORT TERM...OSTUNO LONG TERM...93 AVIATION...93 HYDROLOGY...63 MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 AM EDT WED JUN 18 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 345 PM EDT TUE JUN 17 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATE THAT THE SHORTWAVE RESPONSIBLE FOR LAST NIGHT/S AND THIS MORNING/S CONVECTION HAS PASSED EAST. BEHIND THE SHORTWAVE...RISING 5H RIDGE HGTS AND ASSOC INCREASED SUBSIDENCE AND Q-VECT DIVERGENCE FROM THE WEST LED TO CLEARING SKIES OVER THE WEST HALF OF THE CWA THIS MORNING AND OVER MUCH OF THE EAST HALF THIS AFTERNOON. MIXING 850 MB TEMPS OF 16-17C TO THE SFC YIELDED INLAND HIGH TEMPS IN THE LOWER TO MID 80S OVER THE INTERIOR WEST HALF OF UPPER MI THIS AFTERNOON. LAKE BREEZES HAVE KEPT TEMPS COOLER NEAR THE SHORELINES...GENERALLY IN THE 60S. MODIFIED RUC SNDGS OVER SCNTRL UPPER MI FOR 86/59 YIELD AROUND 800 J/KG. GIVEN THE INSTABILITY PERHAPS SOME CONVECTION COULD BE INITIATED ALONG DEVELOPING LAKE BREEZE BOUNDARIES OVER SCNTRL WI SO WILL CONTINUE TO CARRY SLIGHT CHC POPS INTO THE EVENING HRS. ANOTHER SHORTWAVE OVER ERN NE IS EXPECTED TO MOVE THROUGH SRN/CNTRL WI TONIGHT ALONG AND NORTH OF WARM FRONT. THIS SHORTWAVE WORKING ON AN ENVIRONMENT OF 1500-2500 J/KG WILL TRIGGER ANOTHER AROUND OF CONVECTION ACROSS WI INTO LOWER MI TONIGHT. MODELS INDICATE THAT THE NRN FRINGE OF THIS CONVECTION MAY BRUSH SCNTRL UPR MI MAINLY SRN MNM COUNTY WITH SOME SHRA/TSRA WHERE THERE REMAINS A FEW HUNDRED J/KG OF INSTABILITY. WILL CONTINUE TO CARRY SLIGHT CHC POPS TONIGHT FOR THIS POSSIBILITY BUT BEST CONVECTION SHOULD STAY WELL SOUTH CLOSER TO WARM FRONT AND BETTER INSTABILITY. INCREASINGLY CONFLUENT FLOW ALOFT AHEAD OF THE NRN PLAINS RIDGE INTO THE UPPER GREAT LAKES LATE TONIGHT INTO WEDNESDAY WILL CONTINUE TO ALLOW SFC RDGG FM HUDSON BAY HIGH TO WORK INTO THE UPPER GREAT LAKES. THIS SHOULD ENSURE MOSTLY DRY CONDITIONS ACROSS THE AREA ON WEDNESDAY. EXPECT SLIGHTLY COOLER HIGHS FROM UPPER 70S TO AROUND 80 INLAND WITH COOLER 60S TO LOWER 70S READINGS NEAR THE GREAT LAKES SHORELINES. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 329 PM EDT TUE JUN 17 2014 TWO UPPER TROUGHS WILL BE SURROUNDING THE UPPER GREAT LAKES REGION (ONE OVER THE NORTHERN ROCKIES AND THE OTHER FAR NORTHERN QUEBEC) TO START THE PERIOD...WITH ASSOCIATED SURFACE LOWS TO THE SOUTHEAST OF THE UPPER TROUGHS. OVER THE UPPER GREAT LAKES REGION...AN UPPER RIDGE AXIS WILL BE CENTERED OVER THE AREA...STRETCHING FROM THE OHIO RIVER VALLEY TO JUST WEST OF HUDSON BAY. A HUDSON BAY HIGH WILL BE ASSOCIATED WITH THIS RIDGE AND STRETCHING A SURFACE RIDGE SOUTH OVER EASTERN LAKE SUPERIOR AND LAKE HURON. THIS UPPER AND SURFACE RIDGE WILL GRADUALLY SHIFT EAST WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...ALLOWING THE SHOWERS AND THUNDERSTORMS TO THE WEST OF THE AREA TO SHIFT FROM WEST TO EAST ACROSS THE CWA DURING THAT TIME. WILL KEEP THE SLIGHT CHANCE POPS THAT ARE RIGHT ALONG THE WISCONSIN BORDER WEDNESDAY NIGHT INTO THURSDAY MORNING...JUST IN CASE CONVECTION THAT FIRES CLOSER TO THE BETTER WARM AIR ADVECTION IN MINNESOTA BRUSHES THAT AREA AS IT MOVES SOUTHEAST. OTHERWISE...THE REST OF THE AREA WILL BE DRY WEDNESDAY NIGHT. WITH THE HUDSON BAY HIGH IN PLACE OVER THE EASTERN HALF OF THE CWA ON THURSDAY...EXPECT THE DRY EASTERLY FLOW TO TRY AND HOLD OFF ANY CONVECTION DEVELOPMENT OVER THE AREA FOR THURSDAY. THE BEST OPPORTUNITY WILL COME OVER THE FAR WEST TOWARDS THE LATER PART OF THE AFTERNOON...AS THE NEXT ROUND OF CONVECTION DEVELOPS IN MINNESOTA ON THURSDAY. WITH PROPAGATION VECTORS POINTING TO THE EAST-SOUTHEAST FROM CENTRAL/NORTHERN MINNESOTA...WOULD EXPECT ANY CONVECTION IN THAT AREA TO MOVE OVER WESTERN UPPER MICHIGAN THURSDAY EVENING. THOSE SHOWERS AND THUNDERSTORMS WOULD CONTINUE TO THE EAST THROUGH THE NIGHT...AIDED BY THE BROAD WARM AIR ADVECTION MOVING EASTWARD IN RESPONSE TO THE UPPER TROUGH LIFTING INTO THE NORTHERN PLAINS AND NORTHWEST MINNESOTA. THIS WILL SUPPORT SCATTERED SHOWERS AND SOME WEAK THUNDERSTORMS (MARGINAL INSTABILITY DUE TO WEAKENING MID LEVEL LAPSE RATES) OVER THE AREA ON FRIDAY (ESPECIALLY WEST/CENTRAL IN THE MORNING). WITH THE BROAD/WEAKENING WAA CONTINUING EAST LATER FRIDAY AFTERNOON INTO FRIDAY NIGHT...EXPECT A PERIOD OF NO PRECIP OVER PORTIONS OF THE AREA AS THE UPPER TROUGH TO THE WEST MERGES WITH THE EASTERN UPPER TROUGH. THIS MERGING OF THE UPPER TROUGHS WILL PULL THE LEFT OVER UPPER WAVE AND WEAK SURFACE LOW SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION THIS WEEKEND. THERE CONTINUES TO BE SOME DIFFERENCES ON THE MERGING OF THE TROUGHS AND HOW QUICKLY IT SWEEPS THROUGH... BUT IT DOES APPEAR THAT THERE WILL BE A PERIOD OF STEADIER RAIN MOVING THROUGH THE AREA AT SOME POINT THIS WEEKEND. THE UPPER TROUGH WILL SLIDE SOUTHEAST ON SUNDAY NIGHT AND ALLOW AN UPPER RIDGE FROM THE NORTHERN PLAINS AND CENTRAL CANADA TO MOVE SOUTHEAST INTO THE AREA AND PRODUCE CLEARING SKIES AND SEASONABLE TEMPERATURES. ALSO NEED TO POINT OUT THAT THE DRY EASTERLY FLOW ON THURSDAY AND A MOSTLY SUNNY SKY WILL ALLOW FOR DEEP MIXING AND RH VALUES FALLING TOWARDS 20-25 PERCENT OVER THE EASTERN THIRD OF THE CWA. LIGHT RAINS IN THAT AREA DURING THE LAST 2 DAYS HAS IMPROVED FFMC VALUES...BUT DRY CONDITIONS TODAY AND WEDNESDAY SHOULD ALLOW THE FINE FUELS TO DRY BACK OUT BY THURSDAY. FORTUNATELY...WIND GUSTS SHOULD ONLY BE IN THE 10-20MPH RANGE ON THURSDAY AND LIMIT THE WILDFIRE CONCERNS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1203 AM EDT WED JUN 18 2014 VFR CONDITIONS SHOULD PREVAIL AT KIWD/KCMX/KSAW THROUGH THIS FCST PERIOD AS LOW-LEVELS REMAIN RELATIVELY DRY UNDER DOMINANT HIGH PRESSURE. SOME SHRA/TSRA MAY DEVELOP OVER SOUTHERN AND POSSIBLY INTO CENTRAL UPPER MICHIGAN LATE TONIGHT. HOWEVER...SINCE THE GREATER INSTABILITY TO SUPPORT PCPN REMAINS TO THE SOUTH OVER WI...CONFIDENCE WAS TOO LOW TO INCLUDE MENTION IN THE TAF. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 355 AM EDT WED JUN 18 2014 FOG IS STILL BEING REPORTED EARLY THIS MORNING...MAINLY OVER N LAKE MI AND FAR E LAKE SUPERIOR. EXPECT THIS FOG TO CONTINUE TO SLOWLY DIMINISH THIS MORNING INTO THE EARLY AFTERNOON HOURS. DRIER HIGH PRESSURE OVER S HUDSON BAY WILL REMAIN NEARLY STATIONARY THROUGH THE UPCOMING WEEKEND. A RIDGE EXTENDING FROM THE HIGH TOWARD LAKE SUPERIOR WILL STRENGTHEN AS IT BUILDS TOWARD THE LOWER GREAT LAKES THROUGH THURSDAY NIGHT /BRINGING WITH IT DRIER AIR/. LOOK FOR FUNNELING NE WINDS OVER THE W THIRD OF LAKE SUPERIOR...WITH GUSTS ON THE ORDER OF 20-25KTS. THE RIDGE WILL THEN WEAKEN AND DRIFT E FRIDAY AND SATURDAY AS LOW PRESSURE OVER SE SASKATCHEWAN MOVES TOWARD N MINNESOTA. THE LOW WILL DRIFT SE INTO THE UPPER GREAT LAKES SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR LSZ248>251-265>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...JLB MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1222 PM CDT WED JUN 18 2014 .UPDATE... FOR 18Z AVIATION DISCUSSION BELOW && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 311 AM CDT WED JUN 18 2014 YET ANOTHER STORMY SHORT TERM PERIOD IS ON TAP WITH THIS PERIOD LOOKING TO CONTINUE THE TREAT FOR SEVERE WEATHER AND FLASH FLOODING. AT 4 AM...THE WARM FRONT WAS SPLAYED OUT FROM NEAR YANKTON ENE TO JUST NORTH OF I-90 IN SRN MN. YET ANOTHER ENHANCEMENT OF THE LLJ HAS PROVIDED ENOUGH ISENTROPIC LIFT TO OVERCOME THE CAP THE MOVED IN YESTERDAY TO ALLOW THUNDERSTORMS TO BLOSSOM ACROSS THE MN/IA BORDER REGION. STORMS IN THE MPX CWA HAVE REMAINED MAINLY ELEVATED...THOUGH STORMS ACROSS NRN IA HAVE BEEN ABLE TO BASICALLY MAINTAIN THEIR SFC CONNECTION...HENCE THE TORNADO THAT HAPPENED IN THE SPENCER AREA AFTER 1 AM. THOUGH NOT ROOTED AT THE SFC...PWATS NEAR 1.75" COMBINED WITH FREEZING LEVELS OVER 14K FEET HAS RESULTED IN RAINFALL RATES IN EXCESS OF 2 IN/HR OVERNIGHT. EXPECT THIS ACTIVITY TO SLOWLY DRIFT EAST WHILE WEAKENING OVER THE NEXT FEW HOURS AS THE LLJ BEGINS TO VEER OVER TO THE EAST AND WEAKEN THE REST OF THE MORNING. BASED ON THE HRRR AND RAP H85 MOISTURE TRANSPORT FORECAST...EXPECT THIS ACTIVITY TO HANG AROUND THROUGH ABOUT 15Z BEFORE WE GET INTO ANOTHER PRECIP BREAK THAT LOOKS TO LAST MOST OF THE AFTERNOON. MAIN QUESTION FOR THIS AFTERNOON IS WHERE WILL THE WARM FRONT SETUP. ACTIVITY RIGHT NOW WILL AGAIN FORCE THE WARM FRONT SOUTH INTO IA...LIKELY DOWN TO NEAR THE I-80 CORRIDOR. IN ADDITION TO THAT...IN THE WAKE OF THIS MORNINGS CONVECTION...THE RAP SHOWS THE 12C ISOTHERM AT H7 WORKING BACK UP INTO CENTRAL MN...WHICH WILL PUT A LID ON THINGS THROUGH THE AFTERNOON...MUCH LIKE WE JUST SAW YESTERDAY. LOOKING AT LLJ EVOLUTION...DURING THE AFTERNOON...IT WILL BACK TOWARD THE NORTHWEST AND STRENGTHEN ACROSS THE ERN DAKOTAS...WHICH WILL SHIFT THE FOCUS FOR THUNDERSTORMS FROM THE MS VALLEY BACK INTO THE DAKOTAS BY THE AFTERNOON. AS A RESULT...DELAYED ANY RAMP UP IN POPS TO LIKELIES UNTIL AFTER 00Z...TRYING ORIENT THINGS TOWARD THE NSSL/NMM/ARW WRFS...WHICH SHOW STORMS BLOSSOMING ONCE AGAIN AFTER 3Z. THIS IS IN CONJUNCTION WITH THE ARRIVAL OF THE WARM FRONT...WHICH LOOKS TO SURGE NORTH OUT OF IA THIS EVENING IN RESPONSE TO THE SFC LOW CURRENTLY OVER NE COLORADO WORKING OVER TO NEAR ABERDEEN TONIGHT. WHAT DOES THIS MEAN FOR THE SEVERE THREAT? WELL...ONE THING THAT IS FOR SURE IS INSTABILITY WILL NOT BE ISSUE...AS WE SHOULD SEE MLCAPES IN THE WARM SECTOR AGAIN PUSH 5000 J/KG. FOR A TORNADO THREAT...WE WOULD HAVE TO BANK ON ACTIVITY FORMING ALONG THE WARM FRONT AS IT MOVES NORTH. INSTEAD...FEEL OUR MAIN SEVERE THREAT WILL EXIST MAINLY OVERNIGHT WITH ANY SORT OF SYSTEM THAT COMES OUT OF THE DAKOTAS DURING THE AFTERNOON ALONG WITH STORMS THAT DEVELOP NORTH OF THE WARM FRONT AS IT WORKS INTO MN OVERNIGHT. DEEP LAYER SHEAR LOOKS TO BE MARGINALLY WEAKER WEDNESDAY GIVEN THE PRESENCE OF AN UPPER RIDGE...BUT THE STRONG INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE MORE THAN ENOUGH TO KEEP A WIND/HAIL TREAT GOING THROUGH MUCH OF THE NIGHT. THERE WILL ALSO BE A CONTINUED FLASH FLOOD THREAT WITH THIS ACTIVITY AS WELL. DECIDED ON NOT ISSUING A FLASH FLOOD WATCH AT THIS TIME AS THERE IS ENOUGH UNCERTAINTY AS TO WHERE THIS ROUND OF HEAVY RAIN WILL SET UP THAT IT WAS TO DIFFICULT TO NARROW DOWN A CORRIDOR FOR WHERE ONE WOULD BE NEEDED. WITH THE 00Z CAMS...THERE IS A FAVORED CORRIDOR FOR HEAVY PRECIP FROM SE MN BACK NW TOWARD THE MN/ND/SD BORDER. HOWEVER...THIS WILL LIKELY CHANGE ONCE IT IS BETTER KNOWN WHERE THAT WARM FRONT SETS UP THIS EVENING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 311 AM CDT WED JUN 18 2014 CONVECTION SHOULD BE ONGOING THURSDAY MORNING WITH A MODEST LLJ AND 925-850MB MOISTURE TRANSPORT ACROSS THE ENTIRE FORECAST AREA. A NW-SE ORIENTATED WARM FRONT SHOULD EXTEND ROUGHLY FROM FARGO...TO DAVENPORT...TO CHICAGO BY 12Z THURSDAY MORNING. THIS WILL BE THE FOCUS FOR SCATTERED TO NUMEROUS THUNDERSTORMS. PWATS SHOULD STILL BE RUNNING HIGH WITH 1.50-1.90" ACROSS THE FORECAST AREA AND THE MEAN STEERING WINDS INDICATE A SLOWER STORM MOTION...THEREFORE FLASH FLOODING WILL CONTINUE TO BE A THREAT. THE OVERALL RISK FOR SEVERE APPEARS FAIRLY LOW...BUT THERE IS ENOUGH DEEP LAYER SHEAR AND MODEST STABILITY TO PROVIDE A MINOR WIND AND HAIL THREAT. THE COLD FRONT AND GRADUALLY FILLING SURFACE LOW WILL EXTEND BACK TOWARD THE WEST IN THE CENTRAL AND NORTHERN PLAINS. THE FRONTAL BOUNDARIES WILL LOSE SOME OF THEIR DEFINITION AS THEY MOVE EAST...BUT A SLIGHTLY DRIER AIR MASS ENTERS WESTERN MN BY THURSDAY AFTERNOON AND EVENING. FRIDAY COULD ACTUALLY BE A DRY DAY ACROSS MOST OF MN WITH THE BOUNDARIES HAVING SHIFTED EAST INTO CENTRAL AND EASTERN WI AND THE LOW LEVEL FLOW BECOMING MUCH WEAKER. A WARM AND MAINLY ZONAL PATTERN SETS UP FOR THE WEEKEND...BUT THERE IS STILL A WEAK SURFACE TROUGH HANGING AROUND THE FORECAST AREA...SO WE CAN SIMPLY NOT GO WITH A DRY FORECAST. THE GOOD NEWS LOCALLY /BAD NEWS FOR SOGGY IA/ IS THAT THE NOCTURNAL LLJ FOCUSES SOUTH OF THE AREA FRI/SAT/SUN. THIS SUGGESTS A LOWER THREAT FOR HEAVY RAIN AND FLASH FLOODING. TEMPERATURES LOOK TO REMAIN NEAR OR ABOVE NORMAL THROUGH EARLY NEXT WEEK. THE 18.00Z ECMWF BRINGS A PSEUDO BACK DOOR COLD FRONT ACROSS THE AREA ON TUE-WED...BUT THE PAST COUPLE RUNS OF THE GFS DOES NOT SHOW IT AT THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1222 PM CDT WED JUN 18 2014 EXPECTING WARM TEMPERATURES AT THE MID LEVELS OF THE ATMOSPHERE TO CAP OFF THUNDERSTORM DEVELOPMENT THIS AFTERNOON...SO WILL LIKELY BE UNTIL AFTER DARK UNTIL MOST SITES SEE ANY SHRA/TS ACTIVITY. EXPECT STORMS TO DEVELOP AGAIN TO THE WEST/SOUTH AND LIFT INTO THE AREA THIS EVE/OVERNIGHT. HAVE INCLUDED TEMPOS FOR SAID EXPECTATION...ALONG WITH CIG/VSBY REDUCTIONS TO MVFR. WILL QUITE POSSIBLY SEE SHRA LINGER ON THURSDAY AND PROLONGED MVFR CONDITIONS WITH THE WARM FRONT BISECTING THE AREA...WITH MORE WIDESPREAD THUNDERSTORMS EXPECTED LATE THURSDAY AFTERNOON/EVE AS THE COLD FRONT FINALLY BEGINS TO MAKE ITS WAY EASTWARD ACROSS THE AREA. KMSP... BKN MVFR LEVEL DECK SHOULD CONTINUE SCOURING OUT THIS AFTERNOON WITH VFR CONDITIONS THEN EXPECTED UNTIL AFTER DARK WHEN SHRA/TS CHANCES INCREASE. EXPECT THE HIGHEST LIKELIHOOD OF ORGANIZED ACTIVITY TO OCCUR BETWEEN 04Z AND 09Z...WITH HIT OR MISS SHOWERS AFTER THAT. DO EXPECT A BKN MVFR LEVEL DECK TO STICK AROUND THURSDAY...WITH MORE ORGANIZED TS ACTIVITY ARRIVING AFTER 20Z AS THE COLD FRONT APPROACHES. /OUTLOOK FOR KMSP/ FRI...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS SW 10 KTS. SAT...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS W 10 KTS. SUN...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS WNW 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
725 AM CDT WED JUN 18 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 311 AM CDT WED JUN 18 2014 YET ANOTHER STORMY SHORT TERM PERIOD IS ON TAP WITH THIS PERIOD LOOKING TO CONTINUE THE TREAT FOR SEVERE WEATHER AND FLASH FLOODING. AT 4 AM...THE WARM FRONT WAS SPLAYED OUT FROM NEAR YANKTON ENE TO JUST NORTH OF I-90 IN SRN MN. YET ANOTHER ENHANCEMENT OF THE LLJ HAS PROVIDED ENOUGH ISENTROPIC LIFT TO OVERCOME THE CAP THE MOVED IN YESTERDAY TO ALLOW THUNDERSTORMS TO BLOSSOM ACROSS THE MN/IA BORDER REGION. STORMS IN THE MPX CWA HAVE REMAINED MAINLY ELEVATED...THOUGH STORMS ACROSS NRN IA HAVE BEEN ABLE TO BASICALLY MAINTAIN THEIR SFC CONNECTION...HENCE THE TORNADO THAT HAPPENED IN THE SPENCER AREA AFTER 1 AM. THOUGH NOT ROOTED AT THE SFC...PWATS NEAR 1.75" COMBINED WITH FREEZING LEVELS OVER 14K FEET HAS RESULTED IN RAINFALL RATES IN EXCESS OF 2 IN/HR OVERNIGHT. EXPECT THIS ACTIVITY TO SLOWLY DRIFT EAST WHILE WEAKENING OVER THE NEXT FEW HOURS AS THE LLJ BEGINS TO VEER OVER TO THE EAST AND WEAKEN THE REST OF THE MORNING. BASED ON THE HRRR AND RAP H85 MOISTURE TRANSPORT FORECAST...EXPECT THIS ACTIVITY TO HANG AROUND THROUGH ABOUT 15Z BEFORE WE GET INTO ANOTHER PRECIP BREAK THAT LOOKS TO LAST MOST OF THE AFTERNOON. MAIN QUESTION FOR THIS AFTERNOON IS WHERE WILL THE WARM FRONT SETUP. ACTIVITY RIGHT NOW WILL AGAIN FORCE THE WARM FRONT SOUTH INTO IA...LIKELY DOWN TO NEAR THE I-80 CORRIDOR. IN ADDITION TO THAT...IN THE WAKE OF THIS MORNINGS CONVECTION...THE RAP SHOWS THE 12C ISOTHERM AT H7 WORKING BACK UP INTO CENTRAL MN...WHICH WILL PUT A LID ON THINGS THROUGH THE AFTERNOON...MUCH LIKE WE JUST SAW YESTERDAY. LOOKING AT LLJ EVOLUTION...DURING THE AFTERNOON...IT WILL BACK TOWARD THE NORTHWEST AND STRENGTHEN ACROSS THE ERN DAKOTAS...WHICH WILL SHIFT THE FOCUS FOR THUNDERSTORMS FROM THE MS VALLEY BACK INTO THE DAKOTAS BY THE AFTERNOON. AS A RESULT...DELAYED ANY RAMP UP IN POPS TO LIKELIES UNTIL AFTER 00Z...TRYING ORIENT THINGS TOWARD THE NSSL/NMM/ARW WRFS...WHICH SHOW STORMS BLOSSOMING ONCE AGAIN AFTER 3Z. THIS IS IN CONJUNCTION WITH THE ARRIVAL OF THE WARM FRONT...WHICH LOOKS TO SURGE NORTH OUT OF IA THIS EVENING IN RESPONSE TO THE SFC LOW CURRENTLY OVER NE COLORADO WORKING OVER TO NEAR ABERDEEN TONIGHT. WHAT DOES THIS MEAN FOR THE SEVERE THREAT? WELL...ONE THING THAT IS FOR SURE IS INSTABILITY WILL NOT BE ISSUE...AS WE SHOULD SEE MLCAPES IN THE WARM SECTOR AGAIN PUSH 5000 J/KG. FOR A TORNADO THREAT...WE WOULD HAVE TO BANK ON ACTIVITY FORMING ALONG THE WARM FRONT AS IT MOVES NORTH. INSTEAD...FEEL OUR MAIN SEVERE THREAT WILL EXIST MAINLY OVERNIGHT WITH ANY SORT OF SYSTEM THAT COMES OUT OF THE DAKOTAS DURING THE AFTERNOON ALONG WITH STORMS THAT DEVELOP NORTH OF THE WARM FRONT AS IT WORKS INTO MN OVERNIGHT. DEEP LAYER SHEAR LOOKS TO BE MARGINALLY WEAKER WEDNESDAY GIVEN THE PRESENCE OF AN UPPER RIDGE...BUT THE STRONG INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE MORE THAN ENOUGH TO KEEP A WIND/HAIL TREAT GOING THROUGH MUCH OF THE NIGHT. THERE WILL ALSO BE A CONTINUED FLASH FLOOD THREAT WITH THIS ACTIVITY AS WELL. DECIDED ON NOT ISSUING A FLASH FLOOD WATCH AT THIS TIME AS THERE IS ENOUGH UNCERTAINTY AS TO WHERE THIS ROUND OF HEAVY RAIN WILL SET UP THAT IT WAS TO DIFFICULT TO NARROW DOWN A CORRIDOR FOR WHERE ONE WOULD BE NEEDED. WITH THE 00Z CAMS...THERE IS A FAVORED CORRIDOR FOR HEAVY PRECIP FROM SE MN BACK NW TOWARD THE MN/ND/SD BORDER. HOWEVER...THIS WILL LIKELY CHANGE ONCE IT IS BETTER KNOWN WHERE THAT WARM FRONT SETS UP THIS EVENING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 311 AM CDT WED JUN 18 2014 CONVECTION SHOULD BE ONGOING THURSDAY MORNING WITH A MODEST LLJ AND 925-850MB MOISTURE TRANSPORT ACROSS THE ENTIRE FORECAST AREA. A NW-SE ORIENTATED WARM FRONT SHOULD EXTEND ROUGHLY FROM FARGO...TO DAVENPORT...TO CHICAGO BY 12Z THURSDAY MORNING. THIS WILL BE THE FOCUS FOR SCATTERED TO NUMEROUS THUNDERSTORMS. PWATS SHOULD STILL BE RUNNING HIGH WITH 1.50-1.90" ACROSS THE FORECAST AREA AND THE MEAN STEERING WINDS INDICATE A SLOWER STORM MOTION...THEREFORE FLASH FLOODING WILL CONTINUE TO BE A THREAT. THE OVERALL RISK FOR SEVERE APPEARS FAIRLY LOW...BUT THERE IS ENOUGH DEEP LAYER SHEAR AND MODEST STABILITY TO PROVIDE A MINOR WIND AND HAIL THREAT. THE COLD FRONT AND GRADUALLY FILLING SURFACE LOW WILL EXTEND BACK TOWARD THE WEST IN THE CENTRAL AND NORTHERN PLAINS. THE FRONTAL BOUNDARIES WILL LOSE SOME OF THEIR DEFINITION AS THEY MOVE EAST...BUT A SLIGHTLY DRIER AIR MASS ENTERS WESTERN MN BY THURSDAY AFTERNOON AND EVENING. FRIDAY COULD ACTUALLY BE A DRY DAY ACROSS MOST OF MN WITH THE BOUNDARIES HAVING SHIFTED EAST INTO CENTRAL AND EASTERN WI AND THE LOW LEVEL FLOW BECOMING MUCH WEAKER. A WARM AND MAINLY ZONAL PATTERN SETS UP FOR THE WEEKEND...BUT THERE IS STILL A WEAK SURFACE TROUGH HANGING AROUND THE FORECAST AREA...SO WE CAN SIMPLY NOT GO WITH A DRY FORECAST. THE GOOD NEWS LOCALLY /BAD NEWS FOR SOGGY IA/ IS THAT THE NOCTURNAL LLJ FOCUSES SOUTH OF THE AREA FRI/SAT/SUN. THIS SUGGESTS A LOWER THREAT FOR HEAVY RAIN AND FLASH FLOODING. TEMPERATURES LOOK TO REMAIN NEAR OR ABOVE NORMAL THROUGH EARLY NEXT WEEK. THE 18.00Z ECMWF BRINGS A PSEUDO BACK DOOR COLD FRONT ACROSS THE AREA ON TUE-WED...BUT THE PAST COUPLE RUNS OF THE GFS DOES NOT SHOW IT AT THIS TIME. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 647 AM CDT WED JUN 18 2014 WITH WIDESPREAD VFR CONDITIONS AND RAIN CLEARING THE WEST CENTRAL WI TAF SITES...LOOK FOR A FAIRLY QUIET AVIATION WEATHER DAY IN MN AND WESTERN WI. THE NEXT CHALLENGE IS DETERMINING PRECISELY WHERE...WHEN AND HOW INTENSE THE NEXT ROUND OF THUNDERSTORMS WILL BE THIS EVENING AND TONIGHT. IT LOOKS LIKE STORM INITIATION WILL OCCUR ALONG A LINE FROM WEST CENTRAL MN TO SOUTHEAST MN AND THEN SLOWLY MOVE NORTHEAST WITH TIME. THERE WILL ALSO BE STORMS DEVELOPING IN SD THAT WILL TRY AND HEAD EAST WITH TIME. KMSP... VFR EXPECTED THROUGH ROUGHLY 00Z. WE EXPECT ANOTHER LINE OF SCATTERED TO NUMEROUS SHOWERS AND STORMS THIS EVENING...MOST OF THE ACTIVITY SHOULD FORM SOUTH OF THE AIRPORT...BUT THE MOVEMENT COULD TAKE THESE STORMS NEAR THE AIRPORT FOR THE TAIL END OF THE EVENING COMMUTE. /OUTLOOK FOR KMSP/ FRI...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS SW 10 KTS. SAT...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS W 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...CLF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
408 AM CDT WED JUN 18 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 311 AM CDT WED JUN 18 2014 YET ANOTHER STORMY SHORT TERM PERIOD IS ON TAP WITH THIS PERIOD LOOKING TO CONTINUE THE TREAT FOR SEVERE WEATHER AND FLASH FLOODING. AT 4 AM...THE WARM FRONT WAS SPLAYED OUT FROM NEAR YANKTON ENE TO JUST NORTH OF I-90 IN SRN MN. YET ANOTHER ENHANCEMENT OF THE LLJ HAS PROVIDED ENOUGH ISENTROPIC LIFT TO OVERCOME THE CAP THE MOVED IN YESTERDAY TO ALLOW THUNDERSTORMS TO BLOSSOM ACROSS THE MN/IA BORDER REGION. STORMS IN THE MPX CWA HAVE REMAINED MAINLY ELEVATED...THOUGH STORMS ACROSS NRN IA HAVE BEEN ABLE TO BASICALLY MAINTAIN THEIR SFC CONNECTION...HENCE THE TORNADO THAT HAPPENED IN THE SPENCER AREA AFTER 1 AM. THOUGH NOT ROOTED AT THE SFC...PWATS NEAR 1.75" COMBINED WITH FREEZING LEVELS OVER 14K FEET HAS RESULTED IN RAINFALL RATES IN EXCESS OF 2 IN/HR OVERNIGHT. EXPECT THIS ACTIVITY TO SLOWLY DRIFT EAST WHILE WEAKENING OVER THE NEXT FEW HOURS AS THE LLJ BEGINS TO VEER OVER TO THE EAST AND WEAKEN THE REST OF THE MORNING. BASED ON THE HRRR AND RAP H85 MOISTURE TRANSPORT FORECAST...EXPECT THIS ACTIVITY TO HANG AROUND THROUGH ABOUT 15Z BEFORE WE GET INTO ANOTHER PRECIP BREAK THAT LOOKS TO LAST MOST OF THE AFTERNOON. MAIN QUESTION FOR THIS AFTERNOON IS WHERE WILL THE WARM FRONT SETUP. ACTIVITY RIGHT NOW WILL AGAIN FORCE THE WARM FRONT SOUTH INTO IA...LIKELY DOWN TO NEAR THE I-80 CORRIDOR. IN ADDITION TO THAT...IN THE WAKE OF THIS MORNINGS CONVECTION...THE RAP SHOWS THE 12C ISOTHERM AT H7 WORKING BACK UP INTO CENTRAL MN...WHICH WILL PUT A LID ON THINGS THROUGH THE AFTERNOON...MUCH LIKE WE JUST SAW YESTERDAY. LOOKING AT LLJ EVOLUTION...DURING THE AFTERNOON...IT WILL BACK TOWARD THE NORTHWEST AND STRENGTHEN ACROSS THE ERN DAKOTAS...WHICH WILL SHIFT THE FOCUS FOR THUNDERSTORMS FROM THE MS VALLEY BACK INTO THE DAKOTAS BY THE AFTERNOON. AS A RESULT...DELAYED ANY RAMP UP IN POPS TO LIKELIES UNTIL AFTER 00Z...TRYING ORIENT THINGS TOWARD THE NSSL/NMM/ARW WRFS...WHICH SHOW STORMS BLOSSOMING ONCE AGAIN AFTER 3Z. THIS IS IN CONJUNCTION WITH THE ARRIVAL OF THE WARM FRONT...WHICH LOOKS TO SURGE NORTH OUT OF IA THIS EVENING IN RESPONSE TO THE SFC LOW CURRENTLY OVER NE COLORADO WORKING OVER TO NEAR ABERDEEN TONIGHT. WHAT DOES THIS MEAN FOR THE SEVERE THREAT? WELL...ONE THING THAT IS FOR SURE IS INSTABILITY WILL NOT BE ISSUE...AS WE SHOULD SEE MLCAPES IN THE WARM SECTOR AGAIN PUSH 5000 J/KG. FOR A TORNADO THREAT...WE WOULD HAVE TO BANK ON ACTIVITY FORMING ALONG THE WARM FRONT AS IT MOVES NORTH. INSTEAD...FEEL OUR MAIN SEVERE THREAT WILL EXIST MAINLY OVERNIGHT WITH ANY SORT OF SYSTEM THAT COMES OUT OF THE DAKOTAS DURING THE AFTERNOON ALONG WITH STORMS THAT DEVELOP NORTH OF THE WARM FRONT AS IT WORKS INTO MN OVERNIGHT. DEEP LAYER SHEAR LOOKS TO BE MARGINALLY WEAKER WEDNESDAY GIVEN THE PRESENCE OF AN UPPER RIDGE...BUT THE STRONG INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE MORE THAN ENOUGH TO KEEP A WIND/HAIL TREAT GOING THROUGH MUCH OF THE NIGHT. THERE WILL ALSO BE A CONTINUED FLASH FLOOD THREAT WITH THIS ACTIVITY AS WELL. DECIDED ON NOT ISSUING A FLASH FLOOD WATCH AT THIS TIME AS THERE IS ENOUGH UNCERTAINTY AS TO WHERE THIS ROUND OF HEAVY RAIN WILL SET UP THAT IT WAS TO DIFFICULT TO NARROW DOWN A CORRIDOR FOR WHERE ONE WOULD BE NEEDED. WITH THE 00Z CAMS...THERE IS A FAVORED CORRIDOR FOR HEAVY PRECIP FROM SE MN BACK NW TOWARD THE MN/ND/SD BORDER. HOWEVER...THIS WILL LIKELY CHANGE ONCE IT IS BETTER KNOWN WHERE THAT WARM FRONT SETS UP THIS EVENING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 311 AM CDT WED JUN 18 2014 CONVECTION SHOULD BE ONGOING THURSDAY MORNING WITH A MODEST LLJ AND 925-850MB MOISTURE TRANSPORT ACROSS THE ENTIRE FORECAST AREA. A NW-SE ORIENTATED WARM FRONT SHOULD EXTEND ROUGHLY FROM FARGO...TO DAVENPORT...TO CHICAGO BY 12Z THURSDAY MORNING. THIS WILL BE THE FOCUS FOR SCATTERED TO NUMEROUS THUNDERSTORMS. PWATS SHOULD STILL BE RUNNING HIGH WITH 1.50-1.90" ACROSS THE FORECAST AREA AND THE MEAN STEERING WINDS INDICATE A SLOWER STORM MOTION...THEREFORE FLASH FLOODING WILL CONTINUE TO BE A THREAT. THE OVERALL RISK FOR SEVERE APPEARS FAIRLY LOW...BUT THERE IS ENOUGH DEEP LAYER SHEAR AND MODEST STABILITY TO PROVIDE A MINOR WIND AND HAIL THREAT. THE COLD FRONT AND GRADUALLY FILLING SURFACE LOW WILL EXTEND BACK TOWARD THE WEST IN THE CENTRAL AND NORTHERN PLAINS. THE FRONTAL BOUNDARIES WILL LOSE SOME OF THEIR DEFINITION AS THEY MOVE EAST...BUT A SLIGHTLY DRIER AIR MASS ENTERS WESTERN MN BY THURSDAY AFTERNOON AND EVENING. FRIDAY COULD ACTUALLY BE A DRY DAY ACROSS MOST OF MN WITH THE BOUNDARIES HAVING SHIFTED EAST INTO CENTRAL AND EASTERN WI AND THE LOW LEVEL FLOW BECOMING MUCH WEAKER. A WARM AND MAINLY ZONAL PATTERN SETS UP FOR THE WEEKEND...BUT THERE IS STILL A WEAK SURFACE TROUGH HANGING AROUND THE FORECAST AREA...SO WE CAN SIMPLY NOT GO WITH A DRY FORECAST. THE GOOD NEWS LOCALLY /BAD NEWS FOR SOGGY IA/ IS THAT THE NOCTURNAL LLJ FOCUSES SOUTH OF THE AREA FRI/SAT/SUN. THIS SUGGESTS A LOWER THREAT FOR HEAVY RAIN AND FLASH FLOODING. TEMPERATURES LOOK TO REMAIN NEAR OR ABOVE NORMAL THROUGH EARLY NEXT WEEK. THE 18.00Z ECMWF BRINGS A PSEUDO BACK DOOR COLD FRONT ACROSS THE AREA ON TUE-WED...BUT THE PAST COUPLE RUNS OF THE GFS DOES NOT SHOW IT AT THIS TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1241 AM CDT WED JUN 18 2014 SCATTERED TO NUMEROUS THUNDERSTORMS WILL AFFECT SOUTHERN MN AND PORTIONS OF WEST CENTRAL WI THROUGH THE EARLY MORNING. MOST OF THIS ACTIVITY WILL REMAIN SOUTH OF THE TAF SITES...BUT KEAU AND KRWF WILL CONTINUE TO SEE THUNDER. AT THE OTHER TAF SITES...THE THUNDER THREAT IS TOO UNCERTAIN THIS MORNING TO INCLUDE AT THIS POINT. THERE IS THE CHANCE...HOWEVER...OF MVFR STRATUS THIS MORNING. KMSP... WE THINK THERE WILL BE WIDESPREAD THUNDERSTORMS SOUTH OF THE AIRPORT FOR MOST OF THE EARLY MORNING HOURS...PERHAPS LINGERING PAST SUNRISE. AT THE AIRPORT ITSELF...THE UNCERTAINTY IN STORM COVERAGE THIS FAR NORTH KEEPS US FROM INCLUDING IN THE TAF EARLY THIS MORNING. WE WILL MONITOR CLOSE AND UPDATE BASED ON CURRENT RADAR TRENDS AS WE APPROACH THE MORNING COMMUTE. /OUTLOOK FOR KMSP/ THU...MVFR/IFR WITH SHRA/TSRA LIKELY. WINDS SE 10-15 KTS. FRI...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS SW 10 KTS. SAT...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS W 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR MNZ082>085- 091>093. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...CLF HYDROLOGY...CLF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1004 AM CDT WED JUN 18 2014 .UPDATE... MINOR ADJUSTMENTS TO POPS FOR THIS AFTERNOON/EVENING. && .SHORT TERM... GENERALLY BENIGN EARLY SUMMER WEATHER PATTERN CONTINUES ACROSS THE REGION TODAY. AS EXPECTED...BETTER INFLUX OF LOW LEVEL MOISTURE HAS CONTINUED TO SHIFT MORE TO THE WEST OVER TX/LA AS DEEP ANTICYCLONE BUILDS IN FROM THE EAST. THIS HAS MEANT THAT VERY LITTLE MORNING STRATUS/FOG TODAY. 12Z SOUNDINGS SHOW PRECIPITABLE WATER VALUES AOB 1.5 INCHES WHICH GENERALLY ONLY SUPPORTS SPARSE DIURNAL CONVECTION AT THIS TIME OF YEAR WITHOUT SOME SORT OF SYNOPTIC FORCING. MODELS CONTINUE TO SHOW THAT A WEAK WAVE MOVING SW AROUND MID/UPPER LEVEL HIGH SHOULD PROVIDE ENOUGH ENERGY TO ALLOW FOR DEVELOPMENT OF SOME ISOLATED SHRA/TSRA OVER EASTERN SECTIONS OF AREA THIS AFTERNOON/EVENING. LATEST HRRR AND LOCAL WRF SHOW THIS DEVELOPMENT POTENTIALLY GETTING A BIT FARTHER WEST INTO THE I-55 CORRIDOR THAN PREVIOUSLY INDICATED...SO HAVE ADJUSTED POPS TO ALLOW FOR ISOLATED TSRA A BIT FARTHER WEST. OTHERWISE FORECAST LOOKS ON TRACK AND NO OTHER CHANGES MADE. /AEG/ && .AVIATION...VFR CONDITIONS WILL PREVAIL TODAY THROUGH TONIGHT. ISOLATED SHOWER/TSTM ACTIVITY WILL BE PRESENT ESPECIALLY IN THE EAST BUT TOO SPARSE TO INCLUDE IN THE TAFS AT THIS TIME. ANOTHER ROUND OF MVFR TO IFR CONDITIONS WILL BE POSSIBLE BEFORE SUNRISE THURSDAY MORNING. /28/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 92 71 93 71 / 11 9 20 10 MERIDIAN 93 68 93 69 / 20 10 26 15 VICKSBURG 91 70 92 70 / 7 6 15 10 HATTIESBURG 93 71 93 71 / 21 10 25 14 NATCHEZ 91 71 90 69 / 8 8 17 10 GREENVILLE 92 71 93 71 / 7 4 11 5 GREENWOOD 92 70 93 71 / 8 6 14 10 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ AEG/28
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
111 PM CDT WED JUN 18 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 400 AM CDT WED JUN 18 2014 FORECAST CONCERNS THROUGH THE SHORT TERM WILL CONTINUE TO BE TRYING TO PIN DOWN THUNDERSTORM/SEVERE WEATHER CHANCES ALONG WITH THE HEAT ON WEDNESDAY. AN ISOLATED TORNADIC THUNDERSTORM INDEED DEVELOPED NEAR THE SOUTH DAKOTA BORDER THIS EVENING AND LASTED FOR SEVERAL HOURS OVER CEDAR COUNTY. THE 00Z OAX SOUNDING WAS IMPRESSIVE WITH CAPE OF NEARLY 6400 J/KG AND LITTLE CIN. ALSO OF NOTE WERE THE VERY STEEP LAPSE RATES AND H85 MOISTURE OF 17 DEG. C. A RARE 06Z SOUNDING WAS REQUESTED AND SHOWED AN UNSTABLE ATMOSPHERE WITH NEARLY 5000 J/KG OF CAPE AND 1.64 PWAT. EARLY THIS MORNING...THE MAIN CONVECTIVE COMPLEX IS OVER SOUTHERN MINNESOTA AND NORTHERN IOWA...CLOSER TO THE SURFACE AND H85 WARM FRONT. THE LOW LEVEL JET IS FORECAST TO REMAIN STRONG...40-50KTS OVER KANSAS AND MISSOURI THROUGH 15Z AND THERE IS AN APPROACHING H5 SPEED MAX. IT IS UNCERTAIN IF THIS LOW LEVEL JET CAN GET SOMETHING ELEVATED GOING OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. MOST OF THE OPERATIONAL MODELS ARE DRY THROUGH 21Z. THE EAX 4KM WRF HINTS AT SOMETHING IN THE MORNING ALONG WITH THE SREF. WILL LEAVE MOST OF THE FORECAST AREA DRY...HOWEVER WILL KEEP A SMALL POP IN FOR SOUTHWEST IOWA SHOULD SOMETHING ELEVATED MANAGE TO DEVELOP. THIS WILL NEED TO BE MONITORED THIS A.M. THIS AFTERNOON...THE HEAT BUILDS INTO THE FORECAST AREA WITH HIGHS AGAIN IN THE 90S. MEANWHILE...THE COLD FRONT IS FORECAST TO MOVE INTO CENTRAL NEBRASKA AND THE UPPER LEVEL SUPPORT MOVES INTO THE ROCKIES. THERE ARE A COUPLE OF LOCATIONS FOR CONVECTION...THE PRIMARY FOCUS APPEARS TO BE CLOSER TO THE HEIGHT FALLS...THE COLD FRONT AND THE DEEPENING SURFACE LOW. A SECOND AREA OF CONVECTION MAY DEVELOP IN IOWA AND BUILD BACK INTO THE FORECAST AREA. THE RAP SHOWS A CAP THIS MORNING WITH ELEVATED INSTABILITY AND DESTABILIZATION THIS AFTERNOON WITH THE EROSION OF THE CAP AFTER 20Z AND VERY STEEP LAPSE RATES WITH CAPE AROUND 3000 J/KG. THE NAM/GFS ARE MORE AGGRESSIVE WITH INSTABILITY WITH CAPE OF 4000-6000 J/KG. THE NAM HAS STRONGER DEEP LAYER SHEAR NEAR THE MISSOURI RIVER INTO WESTERN IOWA...WHILE THE GFS HOLDS THE STRONGER SHEAR TO THE WEST OF THE FORECAST AREA UNTIL AFTER MIDNIGHT. WITH HIGH INSTABILITY IN PLACE...SEVERE WEATHER WILL BE POSSIBLE WHERE STORMS DEVELOP. THE STORM PREDICTION CENTER HAS THE ENTIRE FORECAST AREA IN THE SLIGHT RISK AREA. WILL BEGIN TO INCREASE THUNDERSTORM CHANCES LATER THIS AFTERNOON AND CONTINUE TONIGHT AND THURSDAY AS THE UPPER LEVEL STORM SYSTEM MOVES INTO THE PLAINS AND DRIVES THE COLD FRONT THROUGH. WITH THE HIGH INSTABILITY AND FRONTAL BOUNDARIES THERE WILL BE A TORNADO THREAT. THE RAP HAS MORE OF A PRONOUNCED DRYLINE WORKING INTO CENTRAL AND NORTHEAST NEBRASKA. THE NAM HAS A DOUBLE WARMFRONT STRUCTURE WITH NORTHEAST NEBRASKA AND PARTS OF WEST IOWA ALONG WITH AREAS IN SD/MN WITH BACKED FLOW...WHILE THE GFS/EC IS FARTHER NORTH. PLACEMENT OF THESE FEATURES WILL BE KEY TO WHERE THE HIGHER TORNADO POTENTIAL IS. HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THE CONVECTIVE COMPLEXES THAT DEVELOP TONIGHT AND THURSDAY. DEEP MOISTURE WITH PWATS OF 1.5 TO 2 INCHES RETURN AND LOCALLY HEAVY RAINFALL IS POSSIBLE...ESPECIALLY WHERE CONVERGENCE IS INCREASED IN THE VICINITY OF THE FRONTS. HIGH TEMPERATURES SHOULD TOP OUT IN THE 90S WITH HEAT INDEX VALUES AGAIN AROUND 100. THURSDAY/S HIGHS SHOULD BE IN THE 80S. THERE IS A BREAK IN THE RAIN CHANCES THURSDAY NIGHT...HOWEVER THE PUSH OF THE SHORTWAVE WEAKEN AND RETURN FLOW INCREASES WITH THE CHANCE FOR RAIN. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 400 AM CDT WED JUN 18 2014 THE EXTENDED REMAINS UNSETTLED WITH AT OR BELOW NORMAL HIGHS IN THE 80S. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 101 PM CDT WED JUN 18 2014 AT 18Z...TAF SITES WERE BETWEEN WARM FRONT ACROSS NORTHEAST NEBRASKA INTO NORTHWEST IOWA AND COLD FRONT OVER CENTRAL NEBRASKA. EXPECT MAINLY VFR CONDITIONS OUTSIDE OF THUNDERSTORMS THROUGH THE PERIOD. AN INCREASING CHANCE OF STORMS AFTER 06Z AS SURFACE LOW PRESSURE LOCATED OVER NORTH CENTRAL NEBRASKA AT 18Z TRACKS NORTHEAST INTO SOUTHEAST SOUTH DAKOTA AND COLD FRONT PUSHES INTO EASTERN NEBRASKA. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
630 AM CDT WED JUN 18 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 400 AM CDT WED JUN 18 2014 FORECAST CONCERNS THROUGH THE SHORT TERM WILL CONTINUE TO BE TRYING TO PIN DOWN THUNDERSTORM/SEVERE WEATHER CHANCES ALONG WITH THE HEAT ON WEDNESDAY. AN ISOLATED TORNADIC THUNDERSTORM INDEED DEVELOPED NEAR THE SOUTH DAKOTA BORDER THIS EVENING AND LASTED FOR SEVERAL HOURS OVER CEDAR COUNTY. THE 00Z OAX SOUNDING WAS IMPRESSIVE WITH CAPE OF NEARLY 6400 J/KG AND LITTLE CIN. ALSO OF NOTE WERE THE VERY STEEP LAPSE RATES AND H85 MOISTURE OF 17 DEG. C. A RARE 06Z SOUNDING WAS REQUESTED AND SHOWED AN UNSTABLE ATMOSPHERE WITH NEARLY 5000 J/KG OF CAPE AND 1.64 PWAT. EARLY THIS MORNING...THE MAIN CONVECTIVE COMPLEX IS OVER SOUTHERN MINNESOTA AND NORTHERN IOWA...CLOSER TO THE SURFACE AND H85 WARM FRONT. THE LOW LEVEL JET IS FORECAST TO REMAIN STRONG...40-50KTS OVER KANSAS AND MISSOURI THROUGH 15Z AND THERE IS AN APPROACHING H5 SPEED MAX. IT IS UNCERTAIN IF THIS LOW LEVEL JET CAN GET SOMETHING ELEVATED GOING OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. MOST OF THE OPERATIONAL MODELS ARE DRY THROUGH 21Z. THE EAX 4KM WRF HINTS AT SOMETHING IN THE MORNING ALONG WITH THE SREF. WILL LEAVE MOST OF THE FORECAST AREA DRY...HOWEVER WILL KEEP A SMALL POP IN FOR SOUTHWEST IOWA SHOULD SOMETHING ELEVATED MANAGE TO DEVELOP. THIS WILL NEED TO BE MONITORED THIS A.M. THIS AFTERNOON...THE HEAT BUILDS INTO THE FORECAST AREA WITH HIGHS AGAIN IN THE 90S. MEANWHILE...THE COLD FRONT IS FORECAST TO MOVE INTO CENTRAL NEBRASKA AND THE UPPER LEVEL SUPPORT MOVES INTO THE ROCKIES. THERE ARE A COUPLE OF LOCATIONS FOR CONVECTION...THE PRIMARY FOCUS APPEARS TO BE CLOSER TO THE HEIGHT FALLS...THE COLD FRONT AND THE DEEPENING SURFACE LOW. A SECOND AREA OF CONVECTION MAY DEVELOP IN IOWA AND BUILD BACK INTO THE FORECAST AREA. THE RAP SHOWS A CAP THIS MORNING WITH ELEVATED INSTABILITY AND DESTABILIZATION THIS AFTERNOON WITH THE EROSION OF THE CAP AFTER 20Z AND VERY STEEP LAPSE RATES WITH CAPE AROUND 3000 J/KG. THE NAM/GFS ARE MORE AGGRESSIVE WITH INSTABILITY WITH CAPE OF 4000-6000 J/KG. THE NAM HAS STRONGER DEEP LAYER SHEAR NEAR THE MISSOURI RIVER INTO WESTERN IOWA...WHILE THE GFS HOLDS THE STRONGER SHEAR TO THE WEST OF THE FORECAST AREA UNTIL AFTER MIDNIGHT. WITH HIGH INSTABILITY IN PLACE...SEVERE WEATHER WILL BE POSSIBLE WHERE STORMS DEVELOP. THE STORM PREDICTION CENTER HAS THE ENTIRE FORECAST AREA IN THE SLIGHT RISK AREA. WILL BEGIN TO INCREASE THUNDERSTORM CHANCES LATER THIS AFTERNOON AND CONTINUE TONIGHT AND THURSDAY AS THE UPPER LEVEL STORM SYSTEM MOVES INTO THE PLAINS AND DRIVES THE COLD FRONT THROUGH. WITH THE HIGH INSTABILITY AND FRONTAL BOUNDARIES THERE WILL BE A TORNADO THREAT. THE RAP HAS MORE OF A PRONOUNCED DRYLINE WORKING INTO CENTRAL AND NORTHEAST NEBRASKA. THE NAM HAS A DOUBLE WARMFRONT STRUCTURE WITH NORTHEAST NEBRASKA AND PARTS OF WEST IOWA ALONG WITH AREAS IN SD/MN WITH BACKED FLOW...WHILE THE GFS/EC IS FARTHER NORTH. PLACEMENT OF THESE FEATURES WILL BE KEY TO WHERE THE HIGHER TORNADO POTENTIAL IS. HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THE CONVECTIVE COMPLEXES THAT DEVELOP TONIGHT AND THURSDAY. DEEP MOISTURE WITH PWATS OF 1.5 TO 2 INCHES RETURN AND LOCALLY HEAVY RAINFALL IS POSSIBLE...ESPECIALLY WHERE CONVERGENCE IS INCREASED IN THE VICINITY OF THE FRONTS. HIGH TEMPERATURES SHOULD TOP OUT IN THE 90S WITH HEAT INDEX VALUES AGAIN AROUND 100. THURSDAY/S HIGHS SHOULD BE IN THE 80S. THERE IS A BREAK IN THE RAIN CHANCES THURSDAY NIGHT...HOWEVER THE PUSH OF THE SHORTWAVE WEAKEN AND RETURN FLOW INCREASES WITH THE CHANCE FOR RAIN. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 400 AM CDT WED JUN 18 2014 THE EXTENDED REMAINS UNSETTLED WITH AT OR BELOW NORMAL HIGHS IN THE 80S. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 624 AM CDT WED JUN 18 2014 VFR CONDITIONS ARE FORECAST MUCH OF THE TAF PERIOD...WITH SCATTERED THUNDERSTORMS AND ATTENDANT MVFR/IFR CIGS/VSBYS POSSIBLE AFTER ABOUT 03Z. SOUTH WINDS WILL INCREASE INTO THE 15 TO 25KT RANGE BY MID MORNING AND CONTINUE THROUGH 00Z. A FRONTAL BOUNDARY MOVING INTO CENTRAL NEBRASKA LATE IN THE DAY WILL SPARK THUNDERSTORMS...WHICH WILL LIKELY MOVE INTO THE KOFK AREA BETWEEN 03Z AND 06Z...THEN TO KLNK AND KOMA AFTER 06Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
416 AM CDT WED JUN 18 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 400 AM CDT WED JUN 18 2014 FORECAST CONCERNS THROUGH THE SHORT TERM WILL CONTINUE TO BE TRYING TO PIN DOWN THUNDERSTORM/SEVERE WEATHER CHANCES ALONG WITH THE HEAT ON WEDNESDAY. AN ISOLATED TORNADIC THUNDERSTORM INDEED DEVELOPED NEAR THE SOUTH DAKOTA BORDER THIS EVENING AND LASTED FOR SEVERAL HOURS OVER CEDAR COUNTY. THE 00Z OAX SOUNDING WAS IMPRESSIVE WITH CAPE OF NEARLY 6400 J/KG AND LITTLE CIN. ALSO OF NOTE WERE THE VERY STEEP LAPSE RATES AND H85 MOISTURE OF 17 DEG. C. A RARE 06Z SOUNDING WAS REQUESTED AND SHOWED AN UNSTABLE ATMOSPHERE WITH NEARLY 5000 J/KG OF CAPE AND 1.64 PWAT. EARLY THIS MORNING...THE MAIN CONVECTIVE COMPLEX IS OVER SOUTHERN MINNESOTA AND NORTHERN IOWA...CLOSER TO THE SURFACE AND H85 WARM FRONT. THE LOW LEVEL JET IS FORECAST TO REMAIN STRONG...40-50KTS OVER KANSAS AND MISSOURI THROUGH 15Z AND THERE IS AN APPROACHING H5 SPEED MAX. IT IS UNCERTAIN IF THIS LOW LEVEL JET CAN GET SOMETHING ELEVATED GOING OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. MOST OF THE OPERATIONAL MODELS ARE DRY THROUGH 21Z. THE EAX 4KM WRF HINTS AT SOMETHING IN THE MORNING ALONG WITH THE SREF. WILL LEAVE MOST OF THE FORECAST AREA DRY...HOWEVER WILL KEEP A SMALL POP IN FOR SOUTHWEST IOWA SHOULD SOMETHING ELEVATED MANAGE TO DEVELOP. THIS WILL NEED TO BE MONITORED THIS A.M. THIS AFTERNOON...THE HEAT BUILDS INTO THE FORECAST AREA WITH HIGHS AGAIN IN THE 90S. MEANWHILE...THE COLD FRONT IS FORECAST TO MOVE INTO CENTRAL NEBRASKA AND THE UPPER LEVEL SUPPORT MOVES INTO THE ROCKIES. THERE ARE A COUPLE OF LOCATIONS FOR CONVECTION...THE PRIMARY FOCUS APPEARS TO BE CLOSER TO THE HEIGHT FALLS...THE COLD FRONT AND THE DEEPENING SURFACE LOW. A SECOND AREA OF CONVECTION MAY DEVELOP IN IOWA AND BUILD BACK INTO THE FORECAST AREA. THE RAP SHOWS A CAP THIS MORNING WITH ELEVATED INSTABILITY AND DESTABILIZATION THIS AFTERNOON WITH THE EROSION OF THE CAP AFTER 20Z AND VERY STEEP LAPSE RATES WITH CAPE AROUND 3000 J/KG. THE NAM/GFS ARE MORE AGGRESSIVE WITH INSTABILITY WITH CAPE OF 4000-6000 J/KG. THE NAM HAS STRONGER DEEP LAYER SHEAR NEAR THE MISSOURI RIVER INTO WESTERN IOWA...WHILE THE GFS HOLDS THE STRONGER SHEAR TO THE WEST OF THE FORECAST AREA UNTIL AFTER MIDNIGHT. WITH HIGH INSTABILITY IN PLACE...SEVERE WEATHER WILL BE POSSIBLE WHERE STORMS DEVELOP. THE STORM PREDICTION CENTER HAS THE ENTIRE FORECAST AREA IN THE SLIGHT RISK AREA. WILL BEGIN TO INCREASE THUNDERSTORM CHANCES LATER THIS AFTERNOON AND CONTINUE TONIGHT AND THURSDAY AS THE UPPER LEVEL STORM SYSTEM MOVES INTO THE PLAINS AND DRIVES THE COLD FRONT THROUGH. WITH THE HIGH INSTABILITY AND FRONTAL BOUNDARIES THERE WILL BE A TORNADO THREAT. THE RAP HAS MORE OF A PRONOUNCED DRYLINE WORKING INTO CENTRAL AND NORTHEAST NEBRASKA. THE NAM HAS A DOUBLE WARMFRONT STRUCTURE WITH NORTHEAST NEBRASKA AND PARTS OF WEST IOWA ALONG WITH AREAS IN SD/MN WITH BACKED FLOW...WHILE THE GFS/EC IS FARTHER NORTH. PLACEMENT OF THESE FEATURES WILL BE KEY TO WHERE THE HIGHER TORNADO POTENTIAL IS. HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THE CONVECTIVE COMPLEXES THAT DEVELOP TONIGHT AND THURSDAY. DEEP MOISTURE WITH PWATS OF 1.5 TO 2 INCHES RETURN AND LOCALLY HEAVY RAINFALL IS POSSIBLE...ESPECIALLY WHERE CONVERGENCE IS INCREASED IN THE VICINITY OF THE FRONTS. HIGH TEMPERATURES SHOULD TOP OUT IN THE 90S WITH HEAT INDEX VALUES AGAIN AROUND 100. THURSDAY/S HIGHS SHOULD BE IN THE 80S. THERE IS A BREAK IN THE RAIN CHANCES THURSDAY NIGHT...HOWEVER THE PUSH OF THE SHORTWAVE WEAKEN AND RETURN FLOW INCREASES WITHE THE CHANCE FOR RAIN. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 400 AM CDT WED JUN 18 2014 THE EXTENDED REMAINS UNSETTLED WITH AT OR BELOW NORMAL HIGHS IN THE 80S. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1126 PM CDT TUE JUN 17 2014 VFR CONDITIONS ARE INDICATED THROUGH THE TAF CYCLE. WINDS WILL REMAIN 10-15KT OVERNIGHT...THEN INCREASING AND BECOMING MORE SOUTHERLY TO SOUTHWESTERLY DIURNALLY. SHOULD SEE INCREASING MID- LEVEL CLOUDS IN THE LATE AFTERNOON THROUGH EVENING AS CONVECTION DEVELOPS IN THE AREA. FOR NOW...INCLUDED VCSH IN KOMA/KLNK AFTER 00Z. SHRA/TSRA COULD APPROACH OR PASS OVER TAF SITES IN THAT TIME FRAME...BUT WILL HOLD OFF MENTION TO GAIN MORE CONFIDENCE ON PLACEMENT AND TIMING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1236 AM CDT WED JUN 18 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 315 PM CDT TUE JUN 17 2014 MAP ANALYSIS INDICATES A CLOSED UPPER TROPOSPHERIC LOW OVER THE NORTHWESTERN CONUS...AND A RIDGE OVER THE EAST. ENHANCED UPPER TROPOSPHERIC FLOW EXTENDS FROM THE SOUTHWESTERN CONUS...NORTHEAST INTO THE CENTRAL AND NORTHERN PLAINS...AND THEN FARTHER NORTHEAST INTO THE GREAT LAKES REGION AND SOUTHEASTERN CANADA. UPPER TROPOSPHERIC FLOW OVER OUR AREA MAXES OUT AT AROUND 55KTS NEAR 37000FT AGL PER 12Z SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY INDICATES ENHANCED UPPER TROPOSPHERIC MOISTURE EXTENDS FROM THE SOUTHERN PLAINS INTO THE GREAT LAKES REGION...AS WELL AS OVER PORTIONS OF THE ROCKY MOUNTAIN RANGE. AT THE SURFACE A STATIONARY BOUNDARY IS NOTED EXTENDING FROM NORTH CENTRAL NEBRASKA INTO SOUTHWESTERN NEBRASKA AND THE CENTRAL HIGH PLAINS. IN ADDITION...A DRY LINE IS NOTED EXTENDING ACROSS PORTIONS OF WESTERN KANSAS. GUIDANCE SUGGESTS THE UPPER TROPOSPHERIC LOW OVER THE NORTHWESTERN CONUS WILL SLOWLY DRIFT NORTHEAST THROUGH THE NEXT 24 HOURS...LIKELY POSITIONING ITSELF OVER NORTHERN MONTANA BY 00Z THURSDAY. AN UPPER TROPOSPHERIC SHORT WAVE IS ALSO EXPECTED TO SWING TO THE SOUTH OF THE LOW AND BEGIN MOVING INTO THE CENTRAL HIGH PLAINS BY 00Z THURSDAY. AT THE SURFACE...THE STATIONARY BOUNDARY MAY BEGIN TO MEANDER SLIGHTLY SOUTHEAST OR NORTHWEST AS AN AREA OF LOW BAROMETRIC PRESSURE ORGANIZES OVER THE CENTRAL HIGH PLAINS...WHICH MAY RESULT IN PERIODIC NORTHWESTERLY LOWER TROPOSPHERIC FLOW OVER WEST/NORTHWESTERN PORTIONS OF OUR CWA DURING THE DAY WEDNESDAY...BUT FOR THE MOST PART LOWER TROPOSPHERIC FLOW IS EXPECTED TO REMAIN FROM THE SOUTH ACROSS MUCH OF OUR CWA THROUGH THE NEXT 24 HOURS. AN OVERALL LACK IN OMEGA SHOULD PROMOTE DRY CONDITIONS ACROSS OUR AREA THIS AFTERNOON AND EVENING. THE HRRR DOES INDICATE SOME VERY ISOLATED CONVECTION OVER WESTERN NEBRASKA LATE THIS AFTERNOON INTO THIS EVENING AS THE CONVECTIVE TEMPERATURE IS REACHED...AND THE 4KM WRF-NMM INDICATES ISOLATED TO SCATTERED CONVECTION OVER SOUTHEASTERN NEBRASKA AND NORTHEASTERN KANSAS FOR THE SAME REASON. SO ALTHOUGH ISOLATED CONVECTIVE ACTIVITY CERTAINLY CANNOT BE RULED ACROSS THE REGION THIS AFTERNOON AND EVENING...THE PROBABILITY OF ANY ONE LOCATION ACTUALLY OBSERVING THIS ACTIVITY IS TOO LOW FOR INSERTION INTO THE FORECAST AND AS A RESULT...WILL MAINTAIN THE DRY FORECAST FOR OUR CWA FOR THIS AFTERNOON AND EVENING. IN THE OFF CHANCE A THUNDERSTORM CAN GET GOING...IT WOULD HAVE 2000-3000J/KG 0-1KM MLCAPE AND ~35KTS DEEP LAYER BULK SHEAR TO WORK WITH...SO CERTAINLY LARGE HAIL AND STRONG THUNDERSTORM WIND GUSTS COULD RESULT...BUT AGAIN THE PROBABILITY OF SUCH ACTIVITY BEING REALIZED TO TOO LOW FOR INSERTION INTO THE FORECAST AND HWO AT THIS TIME. DURING THE OVERNIGHT HOURS TONIGHT...A 60-70KT LOW LEVEL JET AXIS JUST ABOVE THE BOUNDARY LAYER IS EXPECTED TO DEVELOP FROM CENTRAL KANSAS INTO SOUTHEASTERN NEBRASKA. ALTHOUGH THE NORTHWESTERN PERIPHERY OF THIS JET AXIS WILL LIKELY CLIP OUR CWA...IT APPEARS THE BULK OF ANY MOISTURE CONVERGENCE WILL REMAIN TO OUR EAST...AND THE PRIMARY AXIS OF THERMAL ADVECTION WILL REMAIN TO OUR SOUTHEAST. GIVEN ALL THIS...OPTED TO KEEP OUR FORECAST DRY TONIGHT THROUGH THE MORNING HOURS ON WEDNESDAY AS WELL. HEADING INTO WEDNESDAY AFTERNOON...SYNOPTIC-SCALE OMEGA SHOULD INCREASE SOMEWHAT ACROSS THE REGION AS THE UPPER TROPOSPHERIC SHORT WAVE MOVES INTO THE CENTRAL HIGH PLAINS. THIS INCREASING OMEGA...WORKING IN CONCERT WITH LOWER TROPOSPHERIC CONVERGENCE AND FORCING ALONG THE MEANDERING BAROCLINIC ZONE...AS WELL AS NEAR- ZERO CIN ACROSS MUCH OF THE REGION BY LATE AFTERNOON...SHOULD BE SUFFICIENT FOR AT LEAST SOME ISOLATED CONVECTION BY LATE AFTERNOON AND EARLY EVENING. ONE MIGHT THINK LOCATIONS IN THE VICINITY OF THE LOWER TROPOSPHERIC BAROCLINIC ZONE WILL HAVE A BETTER CHANCE AT OBSERVING CONVECTION...BUT QPF FIELDS FROM VARIOUS MODELS SUGGEST OUR SOUTHERN CWA STANDS A BETTER CHANCE AT OBSERVING CONVECTION DUE TO LOWER CIN VALUES. REALLY HARD TO SAY ONE LOCATION HAS A BETTER CHANCE OVER ANOTHER...SO WENT AHEAD AND BLANKETED THE ENTIRE CWA WITH ~20% POPS BETWEEN 21Z WEDNESDAY AND 00Z THURSDAY. SHOULD DEEP CONVECTION BE REALIZED ACROSS THE AREA WEDNESDAY AFTERNOON AND EVENING...0-1KM MLCAPE VALUES OF 2000-3000J/KG ARE EXPECTED TO ACCOMPANY DEEP LAYER BULK SHEAR VALUES OF 20-30KTS. GIVEN ALL THIS...WILL GO AHEAD AND CONTINUE TO OUTLOOK THE AREA FOR ISOLATED SEVERE WEATHER STARTING LATE WEDNESDAY AFTERNOON. LITTLE CHANGE IN THE LOWER TROPOSPHERIC AIR MASS WILL PROMOTE SIMILAR TEMPERATURE READINGS TONIGHT WHEN COMPARED TO EARLY THIS MORNING...WITH OVERNIGHT LOWS IN THE 60S TO NEAR 70 CURRENTLY FORECAST ACROSS THE CWA. SIMILAR TEMPERATURE READINGS ARE ALSO EXPECTED WEDNESDAY WHEN COMPARED TO TODAY...WITH WEDNESDAY AFTERNOON HIGHS IN THE 90S CURRENTLY EXPECTED. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 315 PM CDT TUE JUN 17 2014 MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MUCH OF THE PERIOD AND TEMPERATURES THROUGH THE PERIOD. A COLD FRONT IS EXPECTED TO MOVE MOST OF THE WAY THROUGH THE FORECAST AREA WEDNESDAY NIGHT. THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP ALONG THE FRONT DURING THE EVENING WITH MORE THUNDERSTORMS MOVING THROUGH THE AREA DURING THE NIGHT AS THE UPPER LEVEL WAVE MOVES INTO THE AREA. THE BEST MUCAPE DURING THIS PERIOD WILL BE DURING THE EVENING HOURS...THEN DIMINISHING LATE WEDNESDAY NIGHT...SO EXPECT ANY SEVERE WEATHER TO BE MAINLY DURING THE EVENING HOURS. THE FRONT LINGERS JUST TO THE EAST THURSDAY MORNING AND PRECIPITATION COULD LINGER INTO THE MORNING HOURS IN THE EAST...BUT THEN AS ANOTHER UPPER LEVEL WAVE MOVES INTO THE AREA DURING THE AFTERNOON THUNDERSTORMS COULD DEVELOP ALONG THE FRONT AND SOME OF THEM COULD BE IN THE EASTERN PART OF THE FORECAST AREA. MOST OF THE AREA WILL BE DRY MOST OF THE DAY. THERE IS GENERALLY NORTHWEST FLOW ACROSS THE AREA DURING THE PERIOD...WITH SEVERAL UPPER LEVEL WAVES THAT MOVE THROUGH. EACH OF THE WAVES BRING THE CHANCE FOR SOME THUNDERSTORMS TO THE AREA. IT CERTAINLY WILL NOT BE RAINING ALL OF THE TIME OVER ALL OF THE AREA...BUT THERE IS A CHANCE. MOST OF THESE ARE PRETTY SMALL CHANCES SINCE THE MODELS HAVE SLIGHT DIFFERENCE IN THE TIMING OF EACH OF THE WAVES. THE BEST CHANCES FOR THUNDERSTORMS WILL BE SATURDAY NIGHT AND SUNDAY NIGHT WHEN THE STRONGEST OF THE UPPER LEVEL WAVES WILL BE MOVING THROUGH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1227 AM CDT WED JUN 18 2014 VFR CONDITIONS REMAIN IN THE FORECAST THROUGH THIS TAF PERIOD. MODELS/GUIDANCE IN GOOD AGREEMENT KEEPING THE MAJORITY OF THE PERIOD WITH S/SWRLY WINDS...WHICH WILL AGAIN HAVE THE POTENTIAL TO BE ON THE GUSTY SIDE DURING THE DAYTIME HOURS. EXPECTING SKIES TO REMAIN MOSTLY CLEAR TONIGHT...WITH INCREASING CLOUDS THROUGH THE REST OF THE PERIOD EXPECTED TO BE IN MID/UPPER LEVELS. SOME MODELS HINT AT THE CHANCE FOR SOME THUNDERSTORM ACTIVITY TO DEVELOP LATE IN THE PERIOD...AND HAVE INSERTED A VC MENTION. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...BRYANT LONG TERM...JCB AVIATION...ADO
AREA FORECAST DISCUSSION
NWS BUFFALO NY
558 PM EDT WED JUN 18 2014 .SYNOPSIS... A FEW SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS FAR SOUTHWESTERN NEW YORK LATER THIS EVENING AS A STORM SYSTEM OVER THE GREAT LAKES DIVES TO OUR SOUTH. OTHERWISE IT WILL BE A DRY NIGHT FOLLOWED BY INCREASING SUNSHINE AND COOLER TEMPERATURES ON THURSDAY AS HIGH PRESSURE BUILDS ACROSS THE REGION FROM CANADA. FAIR WEATHER AND SEASONABLE TEMPERATURES WILL THEN PERSIST THROUGH THE END OF THE WEEK AND INTO THE COMING WEEKEND AS HIGH PRESSURE DRIFTS OVERHEAD. && .NEAR TERM /THROUGH THURSDAY/... THE DOMINANT FEATURE ON REGIONAL RADAR IMAGERY LATE THIS AFTERNOON IS A RATHER OMINOUS LOOKING MCS CURRENTLY TRACKING ACROSS LOWER MICHIGAN. MESOANALYSIS SHOWS THAT MOST OF WESTERN NEW YORK IS UNDER A STABLE AIRMASS WITH A SURFACE FRONTAL BOUNDARY TO OUR SOUTH OVER PA. HOWEVER...EXTRAPOLATED RADAR TRENDS WHICH ARE SUPPORTED BY THE HRRR HAVE THE REMNANTS OF THIS MCS CLIPPING THE SOUTHERN TIER NEAR THE NY/PA BORDER WHERE THERE IS MODEST CAPES OF 500 TO 1000 J/KG. IT STILL APPEARS THE HEAVIEST RAIN WILL STAY TO THE SOUTH OF OUR CWA...BUT THERE PROBABLY WILL BE AT LEAST MEASURABLE PRECIPITATION SOUTH OF A DKK-ELZ LINE. THE NORTHERN PORTION OF THIS COMPLEX WILL WEAKEN AS IT MOVES EAST...BUT MAY BRING A SHOWER OR SPRINKLE FROM THE NIAGARA FRONTIER TO GENESEE VALLEY LATE THIS EVENING. OTHERWISE...SOME SHOWERS HAVE ALSO POPPED UP ALONG THE ST LAWRENCE ALONG THE CONVERGENCE OF A LARGE SCALE NW FLOW AND A SW LAKE BREEZE. THESE INSTABILITY SHOWERS WILL TAPER OFF THIS EVENING. LATER TONIGHT THE FRONTAL BOUNDARY WILL SAG SOUTH AND SET UP A NORTH- NORTHWESTERLY FLOW ADVECTING COOLER AND MUCH DRIER AIR WILL BEGIN TO TAKE HOLD ACROSS THE REGION AS SURFACE HIGH PRESSURE BUILDS SOUTH OUT OF CANADA. TEMPERATURES WILL COOL INTO THE MID TO UPPER 50S OVERNIGHT...COOLEST ACROSS THE NORTH COUNTRY...WITH COOLING INHIBITED SOMEWHAT BY THE ABUNDANT CLOUD COVER ASSOCIATED THE TROUGH. LOOK FOR WIDESPREAD SUNSHINE AND FAIR WEATHER ON THURSDAY AS A MUCH COOLER AND DRIER AIRMASS WILL DISPLACE THE LINGERING MOISTURE IN PLACE OVER THE REGION. THIS SHOULD YIELD A FINE DAY ACROSS THE FORECAST AREA WITH HIGHS TOPPING OUT IN THE MID 70S...WITH 60S ALONG THE LAKE ONTARIO SHERLINE. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... SURFACE HIGH PRESSURE CENTERED OVER JAMES BAY WILL CONTINUE TO BUILD SOUTH THURSDAY NIGHT WITH A DRY NORTHERLY FLOW PUSHING THE AXIS OF SURFACE MOISTURE SOUTH OF THE NEW YORK BORDER. CLEAR SKIES AND LIGHT SURFACE WINDS COMBINED WITH THE DROPPING DEWPOINTS WILL PROVIDE GOOD RADIATIONAL COOLING OVERNIGHT WITH TEMPS FALLING INTO UPPER TO MID 40S EXCEPT RIGHT ALONG THE LAKE SHORES AND IN URBAN AREAS WHICH WILL BOTTOM OUT IN THE LOW 50S. ALSO EXPECT AT LEAST SOME PATCHY RIVER VALLEY FOG ACROSS THE SOUTHERN TIER. COOLER AND DRIER CONDITIONS WILL LINGER THROUGH FRIDAY WITH HIGH PRESSURE REMAINING RIDGED ACROSS NEW YORK. EXPECTING LOTS OF SUNSHINE TO START THEN SOME CLOUDS WILL INCREASE FROM THE WEST AHEAD OF A MID-LEVEL SHORTWAVE DROPPING SOUTH ACROSS THE CENTRAL GREAT LAKES. SURFACE TEMPS WILL RISE INTO A RANGE OF UPPER 70S ACROSS THE SOUTHERN TIER TO AROUND 70 EAST OF LAKE ONTARIO WHERE 850MB TEMPS WILL FALL TO AROUND 8C. FRIDAY NIGHT THROUGH SATURDAY THE MID-LEVEL SHORTWAVE TROUGH MENTIONED ABOVE WILL CROSS LAKE ERIE BRINGING A CHANCE OF SHOWERS ACROSS THE WESTERN SOUTHERN TIER CLEARING TO THE SOUTH BY SATURDAY NIGHT. THE INSTABILITY AXIS WILL REMAIN WELL TO THE SOUTH SO NOT EXPECTING ANY THUNDER. OUTSIDE OF THE SOUTHERN TIER COUNTIES...EXPECT DRY CONDITIONS. TEMPS WILL REACH INTO THE MID 70S SATURDAY AND FALL INTO THE 50S BOTH FRIDAY AND SATURDAY NIGHTS. METEOROLOGICAL SUMMER BEGINS AT 621AM SATURDAY. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... SURFACE HIGH PRESSURE AND WEAK RIDGING ALOFT WILL BRING A GREAT DAY ON SUNDAY WITH A MIX OF SUN AND CLOUDS AND TEMPS CLIMBING INTO THE 70S. SUNDAY NIGHT AND MONDAY THE SURFACE HIGH LOOKS TO SHIFT EAST OFF THE NEW ENGLAND COAST WHICH WILL BRING A RETURN OF WARM AND MOIST SOUTHERLY FLOW. A GENERAL MODEL SOLUTION SHOWS LOW PRESSURE SHIFTING EAST ACROSS SOUTHERN CANADA WITH A COLD FRONT SLOWLY DROPPING SOUTH ACROSS THE GREAT LAKES THROUGH EARLY TO MID NEXT WEEK. INSTABILITY BEGINS INCREASING MONDAY WITH A CHANCE FOR SOME DIURNALLY TRIGGERED AFTERNOON STORMS THEN TUESDAY AND WEDNESDAY THE APPROACHING FRONT WILL PROVIDE FORCING FOR PERIODS OF SHOWERS AND THUNDERSTORMS. WENT WITH BROADBRUSH CHANCE POPS MON-WED TO COVER FOR THE CONVECTION BUT TIMING AND LOCATION WILL NEED TO BE FINE TUNED OVER THE NEXT FEW DAYS. TEMPS WILL RUN WITHIN A FEW DEGREES OF AVERAGE FOR LATE JUNE. && .AVIATION /22Z WEDNESDAY THROUGH MONDAY/... EXPECT MAINLY VFR CONDITIONS THIS EVENING. THE ONLY AREA OF CONCERN IS JHW...WHERE SHOWERS AND POSSIBLY A THUNDERSTORMS WILL PROBABLY MOVE THROUGH LATE THIS EVENING. MID-LEVEL CLOUD COVER WILL LINGER THROUGHOUT MUCH OF THE NIGHT AS AN UPPER LEVEL TROUGH CROSSES THE REGION. ANY REMNANT CONVECTION FROM THE MCS CURRENTLY OVER THE CENTRAL GREAT LAKES SHOULD SLIDE SOUTH OF THE NY/PA BORDER WITH THE ONLY OTHER AFFECTS BEING SOME MVFR CIGS OVER THE HIGHER TERRAIN OF THE SOUTHERN TIER AFTER 06Z. OTHERWISE...EXPECT CONDITIONS TO IMPROVE TO VFR FROM NORTH TO SOUTH ACROSS THE AREA FROM LATE TONIGHT THROUGH THURSDAY AS HIGH PRESSURE AND MUCH DRIER AIR BUILD INTO THE REGION. OUTLOOK... THURSDAY NIGHT THROUGH FRIDAY SATURDAY...VFR WITH A CHANCE OF SHOWERS IN THE SOUTHERN TIER. SUNDAY...VFR. MONDAY...MAINLY VFR WITH A CHANCE OF SHOWERS. && .MARINE... THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS TOWARDS THE PA BORDER THIS EVENING AS THE AREA MAY GET CLIPPED BY A THUNDERSTORM COMPLEX DROPPING SOUTHEAST OUT OF THE CENTRAL GREAT LAKES. OTHERWISE...LARGELY TRANQUIL CONDITIONS SHOULD PERSIST ON THE LAKES FROM LATE TONIGHT THROUGH THE WEEKEND AS HIGH PRESSURE DRIFTS ACROSS THE REGION FROM CANADA. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...WOOD NEAR TERM...APFFEL/WOOD SHORT TERM...SMITH LONG TERM...SMITH AVIATION...WOOD/APFFEL MARINE...WOOD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 PM EDT WED JUN 18 2014 .SYNOPSIS...A STRONG HIGH PRESSURE SYSTEM ALOFT WILL MAINTAIN HOT CONDITIONS ACROSS THE CAROLINAS AND SOUTHERN VIRGINIA THROUGH THURSDAY. A SURFACE FRONT WILL SLIDE SOUTH INTO THE AREA THURSDAY NIGHT AND WILL STALL ACROSS THE REGION THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1025 AM WEDNESDAY... THE LATEST SURFACE ANALYSIS SHOWED SLIGHTLY WEAKER SURFACE RIDGING OVER CENTRAL NORTH CAROLINA...AND THE WATER VAPOR IMAGERY AS WELL AS THE 12Z UPPER-AIR ANALYSIS INDICATED A WEAK SHEAR AXIS OVER THE AREA...BETWEEN LOWER PRESSURE OFF OF THE SOUTHEAST COAST AND A WEAK MID-LEVEL RIDGE AXIS NEAR THE MOUNTAINS. OTHERWISE...CONDITIONS ARE SIMILAR TO MONDAY...WITH WEAK EFFECTIVE SHEAR...MIXED-LAYER CAPE THAT SHOULD RISE AT LEAST INTO THE 1000 TO 2000J/KG RANGE...AND DOWNDRAFT CAPE ON THE ORDER OF 1000J/KG. LIMITING FACTORS FOR DEEP CONVECTION WILL BE THE CONTINUED LACK OF GOOD LOW-LEVEL FORCING AND A SLIGHT INCREASE IN TEMPERATURES AROUND 500MB AS SHOWN BY THE RAP SOUNDINGS FOR THE AFTERNOON. MOST UNSTABLE ON THE RAP SOUNDINGS AND ITS INSTABILITY ANALYSES IS TOWARD KFAY...WHERE LIFTED INDICES ARE FORECAST TO -5C OR SO...AND ALSO WHERE THE RAP FORECASTS THE BETTER 850MB THETA-E. THE LATEST SPC MESOANALYSIS SHOWS THE HIGHER K INDICES THERE AS WELL AS OF MID MORNING. THE LATEST HRRR WRF WOULD...SIMILAR TO YESTERDAY...SHOW THE BETTER CHANCES OF DEEP CONVECTION RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA MOSTLY SOUTH OF U.S. 64 AND CLOSER TO THE YADKIN RIVER...WITH LESSER CHANCES TO THE NORTHEAST WHERE STABILITY APPEARS GREATER AND MOISTURE SOMEWHAT LESS. STILL...AS WAS THE CASE MONDAY AFTERNOON...EVEN WHERE THE AIR MASS IS A LITTLE DRIER AN ISOLATED THUNDERSTORM CAN OCCUR...POSSIBLY WITH ENOUGH LIFT COURTESY OF THE PIEDMONT TROUGH AND MID-LEVEL SUPPORT FROM THE SHEAR AXIS. SLOW- MOVING CELLS COULD PRODUCE VERY LOCALLY HEAVY RAIN...AND IN THIS TYPE OF AIR MASS A BRIEF STRONG-TO-SEVERE WIND GUST FROM THE STRONGEST CELL IS POSSIBLE AS HAS BEEN THE CASE LATELY EACH AFTERNOON FROM A CELL OR TWO. 1000-850MB THICKNESSES SUPPORT HIGHS AT OR POSSIBLY SLIGHTLY ABOVE THE WARMER GUIDANCE...FOR HIGHS IN THE MID TO UPPER 90S...CLOSE TO THE RECORD AT KRDU. HEAT INDICES SHOULD BE HIGHEST TOWARD KGSB...KMEB...KFAY AND KCTZ WHERE THERE SHOULD BE A PERIOD WHERE THOSE VALUES CREEP JUST ABOVE 100. ANY LINGERING CONVECTION THIS EVENING WILL DIMINISH WITHIN AN HOUR OR TWO AFTER SUNSET. IN THEIR WAKE...EXPECT MOSTLY CLEAR-PARTLY CLOUDY SKIES. MIN TEMPS NEAR 70- LOWER 70S. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 315 AM WEDNESDAY... SUBTLE DIFFERENCES BEGIN TO APPEAR THIS PERIOD...NAMELY A GRADUAL WEAKENING OF THE MID-UPPER LEVEL RIDGE. OVERALL...THURSDAY WILL BE SIMILAR TO THE PAST FEW DAYS WITH HOT TEMPERATURES AND A SLIGHT CHANCE OF AN AFTERNOON THUNDERSTORM. LOW LEVEL THICKNESSES STILL SUGGEST MAX TEMPS IN THE MID AND POSSIBLY UPPER 90S. THE LOWERING UPPER LEVEL HEIGHTS WILL ALLOW A CONVECTIVE COMPLEX OVER THE OH VALLEY AND NORTHERN MID ATLANTIC TO DRIFT SOUTHWARD WITH TIME. OUTFLOWS FROM STORMS ASSOCIATED WITH THIS SYSTEM MAY TRIGGER SCATTERED THUNDERSTORMS THURSDAY NIGHT ACROSS ROUGHLY THE NE QUARTER OF CENTRAL NC. THIS IDEA BEING SHARED BY MOST OF THE MODEL GUIDANCE SO WILL INCREASE POPS TO 30-40 PERCENT ACROSS SECTIONS OF THE NE PIEDMONT AND NORTHERN COASTAL PLAIN...TRENDING TO LESS THAN 20 PERCENT ACROSS THE SOUTH. MIN TEMPS MAINLY IN THE LOWER 70S EXPECT NEAR 70 WHERE SKIES REMAIN MOSTLY CLEAR-PARTLY CLOUDY THROUGH THE OVERNIGHT. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY... MEDIUM RANGE MODELS CONTINUE TO SUGGEST A TRANSITION FROM MID LEVEL RIDGING EXTENDING INTO THE AREA TO A BROAD MID LEVEL TROUGH LATE WEEK INTO THE WEEKEND... WITH NORTHWESTERLY TO WEST-NORTHWESTERLY MID LEVEL FLOW ALLOWING FOR HARD TO TRACK (AT THIS FAR OUT) S/W DISTURBANCES... HELPING TO ENHANCE CONVECTION. AT THE SURFACE... A WEAKENING SURFACE FRONT IS EXPECTED TO APPROACH THE REGION DURING THIS TIME FROM THE NORTH. DO NOT EXPECT THIS FRONT TO BE ABLE TO PUSH THROUGH THE AREA WITH ANY TRUE AIRMASS CHANGE GIVEN THE TIME OF YEAR. INSTEAD... THINK WE WILL SEE A SURFACE TROUGH SHARPEN SOME WITH THE ARRIVAL OF THE CYCLONIC FLOW AND POSSIBLY SLOWLY PUSH EASTWARD AND OR SOUTHWARD THROUGH THE AREA. TRYING TO PICK OUT WHEN THE BEST CHANCE FOR POPS WILL BE IS STILL DIFFICULT AT THIS TIME GIVEN THE TIMING OF HARD TO TRACK DISTURBANCE. HOWEVER... WILL CONTINUE TO TREND THE FORECAST LATE WEEK INTO THE WEEKEND TO 30-40 PERCENT CHANCE OF SHOWERS AND STORMS. THE BEST DEEP LAYER SHEAR WILL REMAIN TO THE NORTH... BUT COULD BE ENHANCED BY A PASSING DISTURBANCE. THUS... CANNOT RULE OUT SOME SEVERE STORMS EACH DAY...WITH THE MAIN THREAT OF DAMAGING WINDS ALONG WITH HEAVY RAIN. HIGH TEMPS WILL GO THROUGH A TRANSITION PERIOD AS WELL... LOW 90S NORTH TO UPPER 90S SOUTH ON FRIDAY... WITH MORE LOWER TO MID 90S DURING THE WEEKEND... WITH POSSIBLY SOME UPPER 80S NORTH. LOWS ARE EXPECTED TO GENERALLY BE AROUND 70/LOWER 70S. MEDIUM RANGE GUIDANCE BEGINS TO DIVERGE A BIT IN HOW THEY HANDEL THE NORTHEAST U.S. TROUGH. HOWEVER... AT THIS TIME THINK WE SHOULD AT LEAST SEE DIURNAL CHANCE FOR SHOWERS AND STORMS EITHER WAY. THUS... WILL CONTINUE CHANCE POPS FOR EACH AFTERNOON AND EVENING... WITH HIGH TEMPS GENERALLY IN THE LOWER 90S WITH MAYBE SOME MID 90S SOUTH. LOWS WILL REMAIN AROUND 70/LOWER 70S. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 130 PM WEDNESDAY... ISOLATED TO WIDELY SCATTERED STORMS THIS AFTERNOON SHOULD LARGELY BE CONFINED TO THE SOUTHERN AND WESTERN PORTIONS OF THE FORECAST AREA...IN THE VICINITY OF A WEAK UPPER LEVEL DISTURBANCE OVER THE SOUTH...AND ALONG DIFFERENTIAL HEATING IN THE HIGHER TERRAIN. OUTSIDE OF AFTERNOON CONVECTION AN AREA OF HIGH PRESSURE ALOFT WILL MAINTAIN PREDOMINATELY VFR CONDITIONS THROUGH THURSDAY. SURFACE WINDS WILL REMAIN LIGHT...LESS THAN 10KTS...FROM THE WEST-SOUTHWEST. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO ACCOMPANY A BACK-DOOR COLD FRONT INTO THE AREA THURSDAY NIGHT/EARLY FRIDAY. THE FRONT IS THEN EXPECTED TO STALL OVER THE REGION...SUPPORTING BETTER CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOON AND EVENING. IN ADDITION...AN INCREASING SOUTHERLY LOW LEVEL FLOW WILL INCREASE THE PROBABILITY OF LATE NIGHT AND EARLY MORNING FOG AND STRATUS...AND ASSOCIATED MVFR-IFR CONDITIONS...EACH MORNING STARTING FRIDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CBL NEAR TERM...DJF/WSS SHORT TERM...WSS LONG TERM...BSD AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1025 AM EDT WED JUN 18 2014 .SYNOPSIS...A STRONG HIGH PRESSURE SYSTEM ALOFT WILL MAINTAIN HOT CONDITIONS ACROSS THE CAROLINAS AND SOUTHERN VIRGINIA THROUGH THURSDAY. IT WILL NOT BE AS HOT FRIDAY AND THE WEEKEND AS THE HIGH PRESSURE SYSTEM IS FORECAST TO WEAKEN. THIS WILL ALSO INCREASE THE CHANCE FOR SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1025 AM WEDNESDAY... THE LATEST SURFACE ANALYSIS SHOWED SLIGHTLY WEAKER SURFACE RIDGING OVER CENTRAL NORTH CAROLINA...AND THE WATER VAPOR IMAGERY AS WELL AS THE 12Z UPPER-AIR ANALYSIS INDICATED A WEAK SHEAR AXIS OVER THE AREA...BETWEEN LOWER PRESSURE OFF OF THE SOUTHEAST COAST AND A WEAK MID-LEVEL RIDGE AXIS NEAR THE MOUNTAINS. OTHERWISE...CONDITIONS ARE SIMILAR TO MONDAY...WITH WEAK EFFECTIVE SHEAR...MIXED-LAYER CAPE THAT SHOULD RISE AT LEAST INTO THE 1000 TO 2000J/KG RANGE...AND DOWNDRAFT CAPE ON THE ORDER OF 1000J/KG. LIMITING FACTORS FOR DEEP CONVECTION WILL BE THE CONTINUED LACK OF GOOD LOW-LEVEL FORCING AND A SLIGHT INCREASE IN TEMPERATURES AROUND 500MB AS SHOWN BY THE RAP SOUNDINGS FOR THE AFTERNOON. MOST UNSTABLE ON THE RAP SOUNDINGS AND ITS INSTABILITY ANALYSES IS TOWARD KFAY...WHERE LIFTED INDICES ARE FORECAST TO -5C OR SO...AND ALSO WHERE THE RAP FORECASTS THE BETTER 850MB THETA-E. THE LATEST SPC MESOANALYSIS SHOWS THE HIGHER K INDICES THERE AS WELL AS OF MID MORNING. THE LATEST HRRR WRF WOULD...SIMILAR TO YESTERDAY...SHOW THE BETTER CHANCES OF DEEP CONVECTION RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA MOSTLY SOUTH OF U.S. 64 AND CLOSER TO THE YADKIN RIVER...WITH LESSER CHANCES TO THE NORTHEAST WHERE STABILITY APPEARS GREATER AND MOISTURE SOMEWHAT LESS. STILL...AS WAS THE CASE MONDAY AFTERNOON...EVEN WHERE THE AIR MASS IS A LITTLE DRIER AN ISOLATED THUNDERSTORM CAN OCCUR...POSSIBLY WITH ENOUGH LIFT COURTESY OF THE PIEDMONT TROUGH AND MID-LEVEL SUPPORT FROM THE SHEAR AXIS. SLOW- MOVING CELLS COULD PRODUCE VERY LOCALLY HEAVY RAIN...AND IN THIS TYPE OF AIR MASS A BRIEF STRONG-TO-SEVERE WIND GUST FROM THE STRONGEST CELL IS POSSIBLE AS HAS BEEN THE CASE LATELY EACH AFTERNOON FROM A CELL OR TWO. 1000-850MB THICKNESSES SUPPORT HIGHS AT OR POSSIBLY SLIGHTLY ABOVE THE WARMER GUIDANCE...FOR HIGHS IN THE MID TO UPPER 90S...CLOSE TO THE RECORD AT KRDU. HEAT INDICES SHOULD BE HIGHEST TOWARD KGSB...KMEB...KFAY AND KCTZ WHERE THERE SHOULD BE A PERIOD WHERE THOSE VALUES CREEP JUST ABOVE 100. ANY LINGERING CONVECTION THIS EVENING WILL DIMINISH WITHIN AN HOUR OR TWO AFTER SUNSET. IN THEIR WAKE...EXPECT MOSTLY CLEAR-PARTLY CLOUDY SKIES. MIN TEMPS NEAR 70- LOWER 70S. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 315 AM WEDNESDAY... SUBTLE DIFFERENCES BEGIN TO APPEAR THIS PERIOD...NAMELY A GRADUAL WEAKENING OF THE MID-UPPER LEVEL RIDGE. OVERALL...THURSDAY WILL BE SIMILAR TO THE PAST FEW DAYS WITH HOT TEMPERATURES AND A SLIGHT CHANCE OF AN AFTERNOON THUNDERSTORM. LOW LEVEL THICKNESSES STILL SUGGEST MAX TEMPS IN THE MID AND POSSIBLY UPPER 90S. THE LOWERING UPPER LEVEL HEIGHTS WILL ALLOW A CONVECTIVE COMPLEX OVER THE OH VALLEY AND NORTHERN MID ATLANTIC TO DRIFT SOUTHWARD WITH TIME. OUTFLOWS FROM STORMS ASSOCIATED WITH THIS SYSTEM MAY TRIGGER SCATTERED THUNDERSTORMS THURSDAY NIGHT ACROSS ROUGHLY THE NE QUARTER OF CENTRAL NC. THIS IDEA BEING SHARED BY MOST OF THE MODEL GUIDANCE SO WILL INCREASE POPS TO 30-40 PERCENT ACROSS SECTIONS OF THE NE PIEDMONT AND NORTHERN COASTAL PLAIN...TRENDING TO LESS THAN 20 PERCENT ACROSS THE SOUTH. MIN TEMPS MAINLY IN THE LOWER 70S EXPECT NEAR 70 WHERE SKIES REMAIN MOSTLY CLEAR-PARTLY CLOUDY THROUGH THE OVERNIGHT. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY... MEDIUM RANGE MODELS CONTINUE TO SUGGEST A TRANSITION FROM MID LEVEL RIDGING EXTENDING INTO THE AREA TO A BROAD MID LEVEL TROUGH LATE WEEK INTO THE WEEKEND... WITH NORTHWESTERLY TO WEST-NORTHWESTERLY MID LEVEL FLOW ALLOWING FOR HARD TO TRACK (AT THIS FAR OUT) S/W DISTURBANCES... HELPING TO ENHANCE CONVECTION. AT THE SURFACE... A WEAKENING SURFACE FRONT IS EXPECTED TO APPROACH THE REGION DURING THIS TIME FROM THE NORTH. DO NOT EXPECT THIS FRONT TO BE ABLE TO PUSH THROUGH THE AREA WITH ANY TRUE AIRMASS CHANGE GIVEN THE TIME OF YEAR. INSTEAD... THINK WE WILL SEE A SURFACE TROUGH SHARPEN SOME WITH THE ARRIVAL OF THE CYCLONIC FLOW AND POSSIBLY SLOWLY PUSH EASTWARD AND OR SOUTHWARD THROUGH THE AREA. TRYING TO PICK OUT WHEN THE BEST CHANCE FOR POPS WILL BE IS STILL DIFFICULT AT THIS TIME GIVEN THE TIMING OF HARD TO TRACK DISTURBANCE. HOWEVER... WILL CONTINUE TO TREND THE FORECAST LATE WEEK INTO THE WEEKEND TO 30-40 PERCENT CHANCE OF SHOWERS AND STORMS. THE BEST DEEP LAYER SHEAR WILL REMAIN TO THE NORTH... BUT COULD BE ENHANCED BY A PASSING DISTURBANCE. THUS... CANNOT RULE OUT SOME SEVERE STORMS EACH DAY...WITH THE MAIN THREAT OF DAMAGING WINDS ALONG WITH HEAVY RAIN. HIGH TEMPS WILL GO THROUGH A TRANSITION PERIOD AS WELL... LOW 90S NORTH TO UPPER 90S SOUTH ON FRIDAY... WITH MORE LOWER TO MID 90S DURING THE WEEKEND... WITH POSSIBLY SOME UPPER 80S NORTH. LOWS ARE EXPECTED TO GENERALLY BE AROUND 70/LOWER 70S. MEDIUM RANGE GUIDANCE BEGINS TO DIVERGE A BIT IN HOW THEY HANDEL THE NORTHEAST U.S. TROUGH. HOWEVER... AT THIS TIME THINK WE SHOULD AT LEAST SEE DIURNAL CHANCE FOR SHOWERS AND STORMS EITHER WAY. THUS... WILL CONTINUE CHANCE POPS FOR EACH AFTERNOON AND EVENING... WITH HIGH TEMPS GENERALLY IN THE LOWER 90S WITH MAYBE SOME MID 90S SOUTH. LOWS WILL REMAIN AROUND 70/LOWER 70S. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... AS OF 1025 AM WEDNESDAY... AN AREA OF HIGH PRESSURE ALOFT WILL MAINTAIN VFR CONDITIONS ACROSS CENTRAL NC THROUGH THURSDAY. SURFACE WINDS WILL BE LIGHT...LESS THAN 10KTS...FROM THE WEST-SOUTHWEST. DURING THE HEAT OF THE DAY...A FEW THUNDERSTORMS WILL OCCUR. HOWEVER...DUE TO EXPECTED LIMITED COVERAGE...CHANCES OF A STORM AFFECTING ANY PARTICULAR TERMINAL ARE TOO LOW TO MENTION IN THE FORECAST AT THIS TIME. CURRENTLY... RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA...THE BETTER CHANCE OF ANY STORM WOULD BE TOWARD THE TRIAD AND KFAY...LEAST TOWARD KRWI. FOR FRIDAY AND INTO THE WEEKEND...THE AREA OF HIGH PRESSURE IS FORECAST TO WEAKEN. THIS WILL ALLOW DISTURBANCES IN THE FLOW ALOFT TO BRING A BETTER CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOON AND EVENING. IN ADDITION...AN INCREASING SOUTHERLY LOW LEVEL FLOW WILL INCREASE THE PROBABILITY OF LATE NIGHT AND EARLY MORNING FOG AND STRATUS...AND ASSOCIATED MVFR-IFR CONDITIONS...EACH MORNING STARTING FRIDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...DJF/WSS SHORT TERM...WSS LONG TERM...BSD AVIATION...DJF/WSS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
707 PM CDT THU JUN 19 2014 .UPDATE... ISSUED AT 707 PM CDT THU JUN 19 2014 CONVECTION IS BECOMING PRETTY SCATTERED NOW AND IS DIMINISHING IN INTENSITY AS WELL. THERE ARE STILL A COUPLE OF LIGHTNING STRIKES BUT PCPN IS NOW MOSTLY SHOWERS. DO NOT EXPECT ANY MORE HEAVY RAIN IN THE SHOWERS LEFT THIS EVENING. ANY MORE SHOWERS SHOULD REMAIN ALONG AND NORTH OF THE HIGHWAY 2 CORRIDOR THROUGH MID EVENING BUT WILL HAVE TO WATCH A COUPLE OTHER AREAS. ONE IS DOWN NEAR KABR AND ANOTHER IS WEST OF KBIS. IF THESE HOLD TOGETHER THEY WOULD AFFECT THE FA BY MID TO LATE EVENING OR LATER. SAW SOME GUSTY WINDS AROUND THE SFC LOW EARLY THIS EVENING...WHICH IS NOW LOCATED NEAR KGFK. THINK SPEEDS WILL DIMINISH NOW AND SKIES ARE CLEARING IN SOME AREAS. WITH ALL THE MOISTURE THAT HAS FALLEN OVER THE FA WILL HAVE TO WATCH FOR FOG FORMATION. WILL ADD PATCHY FOG ACROSS THE SOUTH AND EAST FOR NOW AS THE RAP DEVELOPS FOG THERE. MUCH OF THIS WILL DEPEND ON THE DEGREE OF CLEARING AND WINDS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 250 PM CDT THU JUN 19 2014 MODELS ARE IN GOOD OVERALL AGREEMENT TODAY WITH NO REAL PREFERENCE. FOR TONIGHT...EXPECT SOME LINGERING SHOWERS AND STORMS MAINLY IN THE NORTHERN AND NORTHEAST AREAS. SOME STORMS WILL CONTAIN LOCALLY HEAVY RAIN WITH PWATS STILL OVER 1.5 INCHES THROUGH 3Z. MOST AREAS WILL BE DRY AFTER 6Z...AS SUBSIDENCE BEHIND SHORTWAVE MOVES IN. ON FRIDAY...SPC HAS INTRODUCED A SLIGHT RISK FOR SEVERE STORMS ALONG AND EAST OF THE VALLEY DURING THE AFTERNOON. THERE WILL BE INCREASING DEEP LAYERED SHEAR AND SFC BASED CAPES TO AROUND 2000 J/KG ALONG A SFC TROUGH WITH DEEP CYCLONIC FLOW. IT SHOULD BE WARMER THAN TODAY WITH MORE INSOLATION EXPECTED. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 250 PM CDT THU JUN 19 2014 ON SATURDAY...EXPECT A CHANCE OF MAINLY AFTERNOON SHOWERS AND STORMS WITH A WARM/HUMID DAY EXPECTED. THERE WILL ONCE AGAIN BE THE THREAT FOR SOME AFTERNOON SHOWERS AND STORMS...GIVEN MLCAPES AROUND 1500 J/KG AND INCREASING DEEP LAYERED SHEAR ALONG WITH A SHORTWAVE INTO THE VALLEY. A FEW STORMS COULD BE SEVERE GIVEN THE STRONG DEEP LAYERED SHEAR AND AMPLE INSTABILITY/MOISTURE. TEMPS SHOULD WARM ABOVE NORMAL AND IT WILL BE HUMID WITH DEWPOINTS WELL INTO THE 60S. FOR SUNDAY...THERE WILL BE AN OVERALL DRYING TREND WITH SOME COOL ADVECTION. THERE WILL STILL A CHANCE FOR A FEW SHOWERS/STORMS MAINLY IN THE EAST. TEMPS SHOULD BE SLIGHTLY COOLER THAN SATURDAY...BUT STILL SLIGHTLY ABOVE NORMAL. FOR SUN NIGHT THROUGH WED...THE LONG TERM MODELS ARE IN DECENT AGREEMENT WITH LOWER CHANCES FOR PRECIP BY MID NEXT WEEK AS AN UPPER RIDGE SETS UP OVER ERN MT/WRN ND TUE INTO TUE NIGHT. GFS DOES CLOSE OFF DEPARTING LOW AND KEEP SOME LINGERING SHOWERS ESPECIALLY IN THE EAST...RESULTING IN CONSALL HAVING LOW POPS FOR MUCH OF THE PERIOD. WILL LOWER ANY CHANCE POPS ON WED TO 20S BUT KEEP HIGHER POPS IN FOR THU AS ECMWF BRINGS A SW UP BACK SIDE OF THE RIDGE WHILE GFS IS MORE OF A BLOCKING RIDGE THAT COULD BRING A WELL NEEDED LONGER PERIOD OF DRY WEATHER. DAY SIX AND SEVEN A BIT MORE AMBIGUOUS AS THE MODELS DIFFER ON THIS RIDGES DEPARTURE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 707 PM CDT THU JUN 19 2014 NOT SURE HOW FAR EAST THE CLEARING WILL GO TONIGHT. NAM12 SHOWS IT MOVING THRU THE ENTIRE FA. IF IT DOES MANAGE TO CLEAR AT THE TAF SITES AND WINDS BECOME LIGHT WILL HAVE TO WATCH FOR FOG FORMATION. DID NOT ADD ANY FOR THIS SET OF TAFS BUT WILL ADD FOR THE 06Z SET IF HIGH RESOLUTION MODELS STILL SHOW A GOOD POTENTIAL. THREW IN A VCTS MENTION BY AROUND THE NOON HOUR ON FRIDAY AS A LITTLE HEATING MAY SPAWN SOME MORE CONVECTION. && .HYDROLOGY... RECENT HEAVY RAINS OVER THE RED RIVER BASIN IS CAUSING RISES ON THE MAINSTEM RED RIVER AND MINNESOTA TRIBUTARIES. RAINFALL AMOUNTS RANGED FROM 2.5 INCHES AROUND THE WAHPETON/BRECKENRIDGE AREA TO AROUND A QUARTER INCH IN BELTRAMI AND LAKE OF THE WOODS COUNTIES. WITH THE RAINFALL...NEW RIVER POINT WARNINGS HAVE BEEN ISSUED RAISING ABERCROMBIE...FARGO AND OSLO TO MODERATE FLOOD STAGE. AN AREAL FLOOD WARNING HAS BEEN ISSUED UNTIL NOON SUNDAY FOR EAST CENTRAL BELTRAMI COUNTY. BELTRAMI COUNTY EMERGENCY MANAGEMENT RELAYED THAT THE TAMARAC RIVER NEAR WASKISH IS WELL OUT OF ITS BANKS. WATER IS SURROUNDING NUMEROUS HOUSES WITH A FEW ROADS WASHED OUT...AND NUMEROUS AGRICULTURAL FIELDS ARE UNDER WATER. WATER IS ALSO BEGINNING TO APPROACH THE BOTTOMS OF BRIDGES ALONG THE TAMARAC RIVER. MORE WATER IS EXPECTED TO FLOW INTO THE TAMARAC RIVER...AND THE SITUATION CONTINUES TO BE MONITORED. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...GODON SHORT TERM...DK LONG TERM...DK/SPEICHER AVIATION...GODON HYDROLOGY...BH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1229 AM EDT WED JUN 18 2014 .SYNOPSIS... CENTRAL PA WILL REMAIN ON THE NORTHERN PERIPHERY OF A SUBTROPICAL RIDGE CENTERED OVER THE SOUTHEAST STATES THROUGH AT LEAST WEDNESDAY. SLIGHTLY COOLER AND DRIER AIR IS EXPECTED TO WORK INTO THE AREA FOR THE LATTER PART OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... SEVERE THUNDERSTORM WATCH 314 HAS EXPIRED...AND WE`RE DEALING WITH A DISSIPATING LINE OF STORMS NUDGING INTO A MID-LEVEL CAP ACROSS THE SOUTHERN HALF OF PA WILL SLOWLY SAG SOUTH/WEAKEN OVERNIGHT ALLOWING THE TSRA TO MAKE IT AS FAR SOUTH /ALBEIT IN A SLIGHTLY WEAKENED STATE/ AS THE INTERSTATE 80 CORRIDOR AFTER 06Z. A FEW ISOLATED TSRA SHOULD LINGER ACROSS THE NW 2/3RDS OF THE CWA OVERNIGHT...WHILE THE FAR SE ZONES SEE CLEAR TO PARTLY CLOUDY SKIES. IT WILL BE ANOTHER VERY MUGGY OVERNIGHT. LOWS WELL UP IN THE 60S WILL BE SOME 10-15 DEG ABOVE NORMAL. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/... LOW LEVEL NW FLOW ON WEDNESDAY WILL INITIALLY BRING SLIGHTLY DRIER AIR INTO THE REGION...BUT A RETURN SOUTHERLY FLOW IS MADE TO RAPIDLY REDEVELOP BY AFTERNOON OVER OVER WESTERN AREAS. SHORT RANGE MODEL SURFACE PRESSURE PROGS SUGGEST WE WILL BE BASICALLY IN A COL BETWEEN LOW PRESSURE EAST AND WEST OF US...AND HIGH PRESSURE NORTH AND SOUTH. MODELS ONCE AGAIN GENERATE A RESPECTABLE AMOUNT OF INSTABILITY SO MORE DIURNALLY FAVORED CONVECTION SHOULD BE IN STORE. THE IMPLIED PRESENCE OF A LOW LEVEL BOUNDARY OVER SWRN PA SUGGESTS THAT THE BEST CHANCE OF SHOWERS WILL WEST...WITH LESSER CHANCES FURTHER EAST. TEMPERATURES MAY BE A DEGREE OR TWO COOLER THAN TODAY...NOT SIGNIFICANTLY DIFFERENT. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... UPPER RIDGE CURRENTLY OVER THE EASTERN U.S. IS FORECAST TO BE SQUASHED BY AN UPPER LOW FORECAST TO DEEPEN OVER EASTERN QUEBEC MIDWEEEK AND DIG INTO THE CANADIAN MARITIMES BY THE WEEKEND. THIS UPPER LOW WILL PUSH A COLD FRONT SOUTHWARD INTO THE AREA DURING THE LATTER HALF OF THE WEEK...BRINGING AN END TO THE SULTRY TEMPS. THE FRONT IS FCST TO STALL JUST SOUTH OF PA AND SERVE AS A POSSIBLE FOCUS FOR CONVECTION. SEVERAL SHORTWAVES TRAVELING THROUGH THE UPPER FLOW WILL PRODUCE A SERIES OF SFC WAVES ALONG THE FRONT AS IT LIFTS NORTH AS A WARM FRONT AT SOME POINT OVER THE WEEKEND INTO EARLY NEXT WEEK. THIS LOOKS TO SUPPORT AN UNSETTLED PATTERN...THOUGH CERTAINTY OF PCPN ON ANY GIVEN DAY REMAINS IN THE CHANCE CATEGORY GIVEN THE TIME FRAME AND UNCERTAINTY IN THE OVERALL PATTERN. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... BROKEN LINE OF STRONG TO SEVERE TSRA AT 02Z TRACKING ESE FROM NWRN PENN...WILL IMPACT KBFD THROUGH 04Z BEFORE PUSHING EASTWARD AND SOUTHWARD TOWARD KELM-KDUJ. THOUGH MID-LEVEL CAP INCREASES AS ONE HEADS SOUTHWARD...THIS LINE WILL CONTINUE TO SAG SLOWLY SOUTHWARD AFTER MIDNIGHT...ALLOWING THE TSRA TO APPROACH KFIG-KUNV-KIPT AFTER 06Z. THE LINE WILL CONTINUE TO WEAKEN FURTHER AFTER THAT...WITH POTENTIAL FOR SCT SHOWERS FROM KJST-KAOO AND POSS A TSTM AROUND 08-10Z IN VICINITY OFF KMDT-KLNS IF THE MESOSCALE HRRR MODEL HOLDS TRUE /BUT DIDNT MENTION THAT IN TAFS JUST YET WITH FAIR AMOUNT OF UNCERTAINTY IN BOTH STRENGTH AND LOCATION 6+ HRS OUT/. OTHERWISE OVERNIGHT...WARM AND HUMID CONDITIONS CONTINUE. BEHIND THE LINE OF STORMS MAINLY ACROSS THE NW MTNS...SHOULD SEE A LOWER DECK OF MVFR STRATOCU DEVELOP. OTHERWISE NO WIDESPREAD REDUCTIONS ARE EXPECTED. WEDNESDAY SHOULD REMAIN FAIRLY QUIET THROUGH THE FIRST HALF...BUT WARM AND HUMID AIRMASS WILL AGAIN PROVIDE ENOUGH INSTABILITY TO KICK OFF MAINLY AFTERNOON CONVECTION THAT WILL LINGER INTO THE EVENING HOURS. MOST NUMEROUS SHOWERS/TSTMS WILL BE IN THE SW...WITH SCATTERED CONVECTION DEVELOPING ELSEWHERE...ALL PROVIDING LOCAL REDUCTIONS. OUTLOOK... THU...VFR WITH AREAS OF MVFR AND SCT SHOWERS/TSTMS. FRI...NO SIG WX. SAT-SUN...VFR WITH AREAS OF MVFR AND SCT SHOWERS/TSTMS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...DEVOIR/LAMBERT SHORT TERM...LA CORTE LONG TERM...GARTNER/MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1026 PM EDT THU JUN 19 2014 .SYNOPSIS... HIGH PRESSURE WILL WEAKEN AS AN UPPER RIDGE GRADUALLY BREAKS DOWN TONIGHT AND FRIDAY. THIS SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE AREA OVER THE WEEKEND. TYPICAL SUMMERTIME WEATHER CONTINUES ACROSS THE REGION NEXT WEEK. && .NEAR TERM /THROUGH FRIDAY/... EVENING UPDATE...SHOWERS ARE LEAVING THE FCST AREA TO THE SOUTH WHILE ANOTHER LINE OF WEAK CONVECTION APPROACHES THE NRN MTNS. DON/T ANTICIPATE MUCH EFFECT FROM THESE STORMS AS THEY APPROACH AND WEAKEN ON THE TN UPSLOPE SIDE. CAM MODELS ARE OVERDONE WITH THE UPPER ENERGY SUPPORT...EXCEPT FOR THE HRRR WHICH INDICATES A WEAKENING TREND...ALBEIT IN THE WRONG LOCATION. ANYWAY...CURRENT POPS HAVE THIS FEATURE IN HAND. THERE WILL BE ANOTHER AREA OF ACTIVITY APPROACHING THE NC MTNS THROUGH THE OVERNIGHT AS UPPER HEIGHTS FALL...BUT A STRONG MCS TYPE STORM IS UNLIKELY THIS FAR SOUTH. MIN TEMPS LOOK GOOD AND THERE COULD BE AREAS OF DENSE VALLEY FG OVERNIGHT. 730 PM EDT UPDATE...IMPROVING CONDS OVER THE NEXT COUPLE HRS CWFA/WIDE. A COUPLE SHORT LIVED -SHRA ARE DEVELOPING ALONG EXISTING OUTFLOW BOUNDARIES...HOWEVER DRIER AIR IS WORKING IN ALOFT AND WILL HELP DISSIPATE DEBRIS CLOUDINESS AND ANY DEEP CONV POTENTIAL THIS EVENING. MADE SOME TWEAKS TO THE T/TDS GRIDS BASED ON PREVIOUS PRECIPITATION AND LOWERED POPS TO LESS THAN SLIGHT ACROSS THE NRN ZONES. 430 PM EDT UPDATE...ONGOING CONVECTION HAS BECOME QUITE STRONG TO SEVERE WITH A FEW STORMS ACROSS THE NC MTNS AND FTHILLS. UPPER BROAD S/W IS ENHANCING DEEP CONVECTION AND ALLOWING THE STORMS ACROSS THE FTHILLS TO TAP INTO VERY HIGH VALUES OF DCAPE. THE CLT TDWR INDICATED A WIDE AREA OF VELOCITIES WITH ONE STORM ON THE ORDER OF 50+ KTS...NO DOUBT KNOCKING DOWN SEVERAL TREES AND PWR LINES. THUS...A WIND THREAT SEEMS MORE PROBABLE AS THE STORMS MOVE INTO THE PIEDMONT OF THE CAROLINAS THIS AFTERNOON. QUARTER SIZE HAIL HAS BEEN PRETTY MUCH THE LARGEST REPORTED SO FAR...EVEN WITH VERY TALL AND ROBUST STORMS. MAKES SENSE WITH THE RELATIVELY WARM MLVLS AND HIGH FREEZING LEVELS. WILL EXPECT THE BEST COVERAGE OF TSTMS OVER THE I/77 CORRIDOR THROUGH 23Z WITH STORMS ALSO DEVELOPING SOUTH OVER NE GA AND ACROSS NRN UPSTATE. AS OF 215 PM EDT...ISOLD DEEP CONVECTION HAS KICKED OFF OVER THE HIGHER MTNS...WITH CELLS LINED UP UPSTREAM ACRS THE GREAT TENN VALLEY AS WELL...UNDER A WEAK SHORTWAVE ROUNDING THE RIDGE OVER THE SERN STATES. ACTIVITY ALONG THE OLD OUTFLOW BDY ACRS FAR ERN KY AND SRN WV STILL SAGGING SOUTH. LATEST MESO MODELS SHOW BOTH OF THESE LINEAR FEATURES MOVING TOWARD OUR CWFA THRU THE REST OF THE AFTN. INFLOW WINDS ARE WEAK...BUT INSTABILITY AHEAD OF THE LINES IS STRONG AS ONE MIGHT EXPECT. IT LOOKS LIKE THE MESO GUIDANCE IS SUGGESTING MORE OF A PROPAGATION INTO OUR AREA AND SUBSEQUENT REDEVELOPMENT ALONG REMNANT BOUNDARIES. NONETHELESS...HIGHEST POPS REMAIN OVER THE MTNS WITH A LATER INCREASE IN POPS OVER THE PIEDMONT AS ROUNDS OF STORMS FORM ACRS THE AREA. TONIGHT...MOST OF THE ENERGY WITH THE AFOREMENTIONED SHORTWAVE MOVES OFF THE MID-ATLANTIC COAST BUT SOME WEAK DPVA MAY TRAIL IT...MOVING SEWD ACRS THE CWFA THIS EVENING. A MINOR LLVL BOUNDARY IS SHOWN TO MOVE SWD IN THE WAKE OF THE WAVE AS HIGH PRESSURE BUILDS SLIGHTLY S AND E OUT OF THE GREAT LAKES AREA. SOME LINGERING MUCAPE IS SHOWN THOUGH IT DIMINISHES AND IS INHIBITED AND WELL ELEVATED ANYWAY. IT APPEARS MOST LIKELY THAT ANY REMAINING CONVECTION ALONG BOUNDARIES IN OR INVOF THE FA WILL DIMINISH EXCEPT PERHAPS IN THE MTNS. LOWS WILL BE NEAR NORMAL. FRIDAY...FLOW ACRS THE SRN CONUS GENERALLY BECOMES MORE ZONAL. NORTHERLY FLOW PERSISTS WITH LOW PRS OFF THE ATLANTIC COAST AND SOME SEMBLANCE OF THE BOUNDARY REMAINING IN THE AREA...THOUGH ONLY PROVIDING VERY WEAK CONVERGENCE. OVERALL...THE FA REMAINS UNDER WEAKLY SHEARED BUT SEASONABLY HOT AND UNSTABLE CONDITIONS. LAPSE RATES ARE SHOWN TO BE A LITTLE WEAKER THAN THOSE SEEN TODAY...WITH LOWER CAPE VALUES DURING PEAK HEATING. VALUES HOWEVER REMAIN HIGH ENOUGH TO EXPECT A SMALL SEVERE THREAT...FROM DOWNBURST WIND AND HAIL. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... AS OF 145 PM THURSDAY...CHANGES TO THE OVERALL PATTERN WILL BE TYPICALLY SUBTLE DURING THE SHORT TERM PERIOD...AND ARE UNLIKELY TO HAVE A GREAT DEAL OF IMPACT ON THE SENSIBLE WEATHER. THE UPPER RIDGE IS FORECAST TO SLOWLY RETROGRADE TOWARD THE SOUTH CENTRAL CONUS AND WEAKEN DURING THE PERIOD...PLACING THE SOUTHEAST AND MID-ATLANTIC ALONG THE SOUTHERN PERIPHERY OF THE WESTERLIES...WITH A DEEP NW FLOW ANTICIPATED ACROSS OUR AREA. WHILE THIS WILL THEORETICALLY RENDER THE AREA MORE SUSCEPTIBLE TO ORGANIZED CONVECTION MOVING OUT OF THE OHIO VALLEY REGION...BASED UPON WIND PROFILES...IT IS DOUBTFUL THAT ANYTHING TOO ORGANIZED AND SELF-SUSTAINING WILL BE ABLE TO DEVELOP UPSTREAM...AS ONE MAY NEED TO TRAVEL AS FAR NORTH AS THE CANADIAN BORDER TO FIND ROBUST SHEAR. NEVERTHELESS...WITH A WEAK COLD FRONT APPROACHING THE REGION...AND HALFWAY DECENT STEERING CURRENTS (MEAN CLOUD BEARING WINDS ON THE ORDER OF 15-20 KTS...ABOVE CLIMO POPS (GENERALLY 30-40 PERCENT DURING THE AFTERNOON/EVENING...20/30 PERCENT DURING THE EARLY MORNING HOURS) APPEAR WARRANTED THROUGH THE PERIOD. THE WEAK COLD FRONT MAY BACK DOOR ITS WAY THROUGH THE AREA BY THE END OF THE WEEKEND...POSSIBLY KNOCKING TEMPS DOWN TO NEAR...OR SLIGHTLY BELOW CLIMO ACROSS THE NC PIEDMONT...IN ADDITION TO PROVIDING A FOCUS FOR INITIATION OF AFTERNOON/EVENING SHOWERS AND STORMS. OVERALL...TYPICAL EARLY SUMMER WEATHER APPEARS IN STORE THIS WEEKEND...WITH PERHAPS SLIGHTLY HIGHER COVERAGE OF CONVECTION THAN IS TYPICAL. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 1245 PM THURSDAY...NO BIG CHANGES WERE MADE TO THE FCST IN THE MEDIUM RANGE. THE UPPER PATTERN WILL BE PROGRESSIVE...WITH RELATIVELY FLAT FLOW ACRS THE ERN CONUS. THE WESTERLIES/POLAR JET WILL STAY WELL NORTH OF THE CWFA. SO EXPECT PRIMARILY DIURNALLY-DRIVEN CONVECTION EVERY DAY THRU LATE NEXT WEEK. THE OPERATIONAL GFS AND ECWMF DIVERGE QUITE A BIT BY MIDWEEK...WITH THE GFS EARLIER AND DEEPER WITH A LONGWAVE TROF ACRS THE MIDWEST TO THE GREAT LAKES. THE ECMWF KEEPS STRONGER RIDGING ALONG THE EAST COAST. THE GFE/ECMWF ENSEMBLE MEANS WERE A COMPROMISE AND PREFERRED BY WPC. THIS KEEPS ANY SIGNIFICANT/SYNOPTIC FRONTAL BOUNDARIES TO OUR NORTH AND WEST THRU THURSDAY. I BLENDED THE WPC/CONS/BCCONSALL WITH OFFICIAL...WHICH RESULTS IN ONLY SMALL CHANGES. BEST COVERAGE OF CONVECTION WILL BE ACRS THE MTNS EACH DAY. TEMPS WILL CONTINUE TO BE SLIGHTLY ABOVE NORMAL THRU THE MEDIUM RANGE. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... AT KCLT...EXPECT DEBRIS CLOUDINESS TO WANE THROUGH THE OVERNIGHT WITH NO THREAT OF LOW STCU OR FG DEVELOPMENT AROUND DAYBREAK. A S/W WILL CROSS THE AREA IN THE AFTERNOON AND BACK THE PREVAILING N/LY WINDS WNW/LY AFT 21Z. THERE WILL BE ANOTHER CHANCE OF CONVECTION AND TEMPO GUSTS WITH LOW CIGS/VSBY NEAR THE TERMINAL AFT 21Z WHICH WILL BE COVERED BY A PROB30 TSTM THROUGH 00Z. ELSEWHERE...EXPECT IMPROVING SKY CONDITIONS OVERNIGHT AS DRY AIR WORKS IN AND DISSIPATES THE DEBRIS CLOUDINESS. KAVL AND KHKY BOTH RECEIVED A GOOD AMOUNT OF RAINFALL TODAY AND WILL ANTICIPATE SOME MVFR VSBY AROUND DAYBREAK FOR A FEW HRS AT THESE SITE. SCT TSTMS WILL BE POSSIBLE ONCE AGAIN AT EACH TERMINAL DURING THE LATER AFTERNOON WITH AN ULVL S/W CROSSING OVERHEAD...SO PROB30 TSTMS WILL BEGIN AROUND 21Z AT ALL LOCALES. OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED INTO THE WEEKEND...WITH THE GREATEST COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF RECENT RAINFALL. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-02Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 91% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...ARK NEAR TERM...SBK/WIMBERLEY SHORT TERM...JDL LONG TERM...ARK AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
434 PM EDT WED JUN 18 2014 .SYNOPSIS... DEEP HIGH PRESSURE AND AN ASSOCIATED UPPER LEVEL RIDGE WILL PERSIST THROUGHOUT THE AREA THROUGH THE END OF THE WEEK. THIS WILL KEEP A SEASONABLY WARM AIR MASS IN PLACE THROUGH THE WEEKEND. HIGH PRESSURE WILL WEAKEN AS THE RIDGE BREAKS DOWN BY FRIDAY AFTERNOON WHICH SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND STORMS ACROSS THE ENTIRE AREA OVER THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... 430 PM EDT UPDATE...SEVERE STORMS ARE BUILDING ALONG A WEAK BOUNDARY FROM THE NW NC PIEDMONT SW INTO THE ERN UPSTATE. NOT MUCH STORM MOTION WITH THESE STORMS AND SVR WINDS HAVE NOT BEEN A HUGE THREAT...HOWEVER A LOCALIZED WET DOWNBURST IS NOT OUT OF THE QUESTION AS THE STORMS NEAR AN AREA OF HIGHER DCAPE. LARGE HAIL WILL BE THE MAIN THREAT OVER THE NEXT FEW HRS. AS OF 200 PM...CONVECTION IS BLOSSOMING MORE READILY THAN YESTERDAY ACRS THE MTNS. I UPDATED THE POP TO TRY TO MATCH TRENDS. MOST OF THE HIGH TERRAIN LOOKS TO GET WORKED OVER BY THE CONVECTION BY SUNSET. HOWEVER...CONFIDENCE IS STILL LOW ON HOW MUCH WILL DEVELOP ACRS THE PIEDMONT. STORM MOTION IS VERY SLOW...AND CELLS HAVE GENERALLY WEAKENED SO FAR AS THEY TRY TO ROLL OFF THE ESCARPMENT. HOWEVER...THE VIS SAT IMAGERY SHOWS A CUMULUS FIELD GETTING MORE ROBUST...WITH A COUPLE OF ISOLD STORMS DEVELOPING EAST OF CHARLOTTE. THE 15Z-16Z HRRR RUNS ARE SHOWING A CLUSTER OF STORMS DEVELOPING SOUTH CHARLOTTE...WITH OUTFLOW FANNING OUT AND TRIGGERING NEW CELLS ACRS MUCH OF THE PIEDMONT LATE AFTN INTO EARLY EVENING. THE HRRR TENDS TO BE OVERDONE...BUT IT DOES SHOW THE POTENTIAL. SO I DID INCREASE POPS FOR PORTIONS OF THE PIEDMONT...BUT STILL GENERALLY SLGT CHC TO LOW-END CHC. AS FOR SEVERE POTENTIAL...IT LOOKS LIKE CELLS ARE TOPPING OUT JUST SHORT OF OBJECTIVE CRITERIA SO FAR. LAPS CAPE ANALYSIS SHOWS 3000-4000 J/KG ACRS MUCH OF THE PIEDMONT. SO I THINK THERE WILL BE A FEW PULSE SEVERE STORMS...WITH QUARTER-SIZE HAIL AND/OR DAMAGING WINDS. TONIGHT...CONVECTION SHUD WANE QUICKLY AROUND SUNSET. SIMILAR TO LAST COUPLE NIGHTS...CLOUDS SHUD DISSIPATE AND WINDS REMAIN CALM/LIGHT. THERE WILL BE SOME VLY FOG IN THE NC MTNS. TEMPS WILL BE ABOVE NORMAL IN THE 60S MTNS AND UPR 60S TO LWR 70S PIEDMONT. THURSDAY...A SHORTWAVE TROF WILL DIVE INTO THE GREAT LAKES...HELPING WEAKEN THE LARGE UPPER RIDGE ATOP THE CWFA. HOWEVER...GUIDANCE SHOWS ONLY SUBTLE CHANGES IN THE ENVIRONMENT FOR OUR AREA. SO EXPECT ANOTHER HOT DAY WITH SCT-NUM AFTN SHWRS/TSTMS IN THE MTNS AND ISOLD-SCT IN THE PIEDMONT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 300 PM WEDNESDAY...THE UPPER RIDGE OVER THE CAROLINAS AND GA WILL GRADUALLY BREAK DOWN FROM THE EAST FROM THURSDAY NIGHT THROUGH SATURDAY...AS A LOW AMPLITUDE UPPER TROUGH SETS UP OFF THE EAST COAST. THIS WILL ALLOW A COLD FRONT TO MOVE SOUTH INTO NORTH CAROLINAS ON THURSDAY NIGHT AND FRIDAY. THE GFS STALLS THE FRONT NEAR THE SC BORDER ON FRIDAY NIGHT...WHILE THE NAM IS SLIGHT FARTHER NORTH. IN ANY EVENT AN INCREASE IN CONVECTIVE ACTIVITY IS EXPECTED WITH THE ARRIVAL OF THIS BOUNDARY. MODEL SOUNDING SHOW A BIT MORE SHEAR BY THIS TIME...ALTHOUGH INSTABILITY IS MODEST. ALTHOUGH STEERING FLOW IS BETTER THAN IN PREVIOUS DAYS...MOVING CELLS ALONG...SOME CONCERN EXISTS FOR REPEAT CELLS TRAINING EAST ALONG THE BOUNDARY RESULTING IN HEAVY RAINFALL. TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL...BUT NOT AS MUCH SO ALONG INTERSTATE 40 WHERE CLOUD COVER WILL BE BEST ALONG THE BOUNDARY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 115 PM EDT WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SUNDAY WITH PERSISTENT UPPER RIDGING TO OUR WEST AND BROAD UPPER TROFFING TO OUR NE. THE PATTERN IS EXPECTED TO FLATTEN OUT EARLY IN THE PERIOD BEFORE ANOTHER...DEEPER UPPER TROF DIGS DOWN OVER THE GREAT LAKES WITH THE TROF AXIS TO OUR NORTH BY THE END OF THE MEDIUM RANGE. THE LONG RANGE MODELS DIFFER A FAIR AMOUNT WRT THE EVOLUTION OF THE UPPER TROF WITH THE ECMWF DEVELOPING A MORE AMPLIFIED AND COHERENT SYSTEM COMPARED TO THE GFS. THE GFS TRIES TO DEVELOP THE TROF 1 TO 2 DAYS EARLIER AND KEEPS IT FARTHER NORTH AS IT PROGRESSES EASTWARD. DIURNAL POPS WERE INCREASED A BIT ON BOTH MON AND TUES NEXT WEEK TO REFLECT GENERALLY MORE MOIST GUIDANCE. OTHER THAN THAT...NO MAJOR CHANGES WERE MADE TO THE SENSIBLE FCST. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... AT KCLT...THE ATMOSPHERE APPEARS A BIT MORE UNSTABLE THAN THE EARLIER GUIDANCE LED ON...BASED ON CURRENT TRENDS. NUMEROUS SHRA/TSRA HAVE DEVELOPED ACRS THE SOUTHERN APPALACHIANS...AND THE VIS SAT IMAGERY SHOWS CUMULUS CONGESTUS INCREASING ACRS THE CAROLINA PIEDMONT. THE LATEST HRRR ALLOWS SEVERAL CELLS TO DEVELOP WHERE THIS CONGESTUS IS...SO I THINK THERE WILL BE A FEW STORMS AROUND KCLT THIS AFTN. ENUF TO WARRANT A TEMPO FOR TS. WINDS WILL BE LIGHT AND FAVOR A SW DIRECTION...EXCEPT NEAR TS...WHERE OUTFLOWS WILL BE VARIABLE. CONVECTION SHUD WANE QUICKLY THIS EVENING...WITH LIGHT WINDS AND CLEARING SKIES OVERNIGHT. NOT EXPECTING MUCH FOG POTENTIAL THURSDAY MORNING. ANOTHER ROUND OF DIURNAL SHRA/TSRA EXPECTING SIMILAR TO LAST FEW DAYS...BUT BEYOND THE 18Z TAF PERIOD FOR KCLT. ELSEWHERE...AS MENTIONED ABOVE...CONVECTION WILL BE MAIN CONCERN THIS AFTN. HAVE VCTS AND TEMPO GROUPS FOR TS AT ALL SITES...GIVEN THE SCATTERED NATURE OF STORMS. CHCS ARE STILL ONLY 20-30% FOR DIRECT IMPACT AT MOST SITES...WITH BEST CHC AT KAVL. CONVECTION WANES QUICKLY AFTER SUNSET. GUIDANCE SHOWING SOME FOG POTENTIAL AT KAVL...BUT OTHERWISE...NOT ENUF CONFIDENCE TO MENTION IN THE TAFS. WINDS WILL BE LIGHT...EXCEPT NEAR TSTMS. OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED THROUGH THE WEEK...WITH THE GREATEST COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF RECENT RAINFALL. CONFIDENCE TABLE... 20-02Z 02-08Z 08-14Z 14-20Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 91% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 95% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...STAARMANN NEAR TERM...ARK/SBK SHORT TERM...JAT LONG TERM...JPT AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
226 PM EDT WED JUN 18 2014 .SYNOPSIS... DEEP HIGH PRESSURE AND AN ASSOCIATED UPPER LEVEL RIDGE WILL PERSIST THROUGHOUT THE AREA THROUGH THE END OF THE WEEK. THIS WILL KEEP A SEASONABLY WARM AIR MASS IN PLACE THROUGH THE WEEKEND. HIGH PRESSURE WILL WEAKEN AS THE RIDGE BREAKS DOWN BY FRIDAY AFTERNOON WHICH SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND STORMS ACROSS THE ENTIRE AREA OVER THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... AS OF 200 PM...CONVECTION IS BLOSSOMING MORE READILY THAN YESTERDAY ACRS THE MTNS. I UPDATED THE POP TO TRY TO MATCH TRENDS. MOST OF THE HIGH TERRAIN LOOKS TO GET WORKED OVER BY THE CONVECTION BY SUNSET. HOWEVER...CONFIDENCE IS STILL LOW ON HOW MUCH WILL DEVELOP ACRS THE PIEDMONT. STORM MOTION IS VERY SLOW...AND CELLS HAVE GENERALLY WEAKENED SO FAR AS THEY TRY TO ROLL OFF THE ESCARPMENT. HOWEVER...THE VIS SAT IMAGERY SHOWS A CUMULUS FIELD GETTING MORE ROBUST...WITH A COUPLE OF ISOLD STORMS DEVELOPING EAST OF CHARLOTTE. THE 15Z-16Z HRRR RUNS ARE SHOWING A CLUSTER OF STORMS DEVELOPING SOUTH CHARLOTTE...WITH OUTFLOW FANNING OUT AND TRIGGERING NEW CELLS ACRS MUCH OF THE PIEDMONT LATE AFTN INTO EARLY EVENING. THE HRRR TENDS TO BE OVERDONE...BUT IT DOES SHOW THE POTENTIAL. SO I DID INCREASE POPS FOR PORTIONS OF THE PIEDMONT...BUT STILL GENERALLY SLGT CHC TO LOW-END CHC. AS FOR SEVERE POTENTIAL...IT LOOKS LIKE CELLS ARE TOPPING OUT JUST SHORT OF OBJECTIVE CRITERIA SO FAR. LAPS CAPE ANALYSIS SHOWS 3000-4000 J/KG ACRS MUCH OF THE PIEDMONT. SO I THINK THERE WILL BE A FEW PULSE SEVERE STORMS...WITH QUARTER-SIZE HAIL AND/OR DAMAGING WINDS. TONIGHT...CONVECTION SHUD WANE QUICKLY AROUND SUNSET. SIMILAR TO LAST COUPLE NIGHTS...CLOUDS SHUD DISSIPATE AND WINDS REMAIN CALM/LIGHT. THERE WILL BE SOME VLY FOG IN THE NC MTNS. TEMPS WILL BE ABOVE NORMAL IN THE 60S MTNS AND UPR 60S TO LWR 70S PIEDMONT. THURSDAY...A SHORTWAVE TROF WILL DIVE INTO THE GREAT LAKES...HELPING WEAKEN THE LARGE UPPER RIDGE ATOP THE CWFA. HOWEVER...GUIDANCE SHOWS ONLY SUBTLE CHANGES IN THE ENVIRONMENT FOR OUR AREA. SO EXPECT ANOTHER HOT DAY WITH SCT-NUM AFTN SHWRS/TSTMS IN THE MTNS AND ISOLD-SCT IN THE PIEDMONT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 300 PM WEDNESDAY...THE UPPER RIDGE OVER THE CAROLINAS AND GA WILL GRADUALLY BREAK DOWN FROM THE EAST FROM THURSDAY NIGHT THROUGH SATURDAY...AS A LOW AMPLITUDE UPPER TROUGH SETS UP OFF THE EAST COAST. THIS WILL ALLOW A COLD FRONT TO MOVE SOUTH INTO NORTH CAROLINAS ON THURSDAY NIGHT AND FRIDAY. THE GFS STALLS THE FRONT NEAR THE SC BORDER ON FRIDAY NIGHT...WHILE THE NAM IS SLIGHT FARTHER NORTH. IN ANY EVENT AN INCREASE IN CONVECTIVE ACTIVITY IS EXPECTED WITH THE ARRIVAL OF THIS BOUNDARY. MODEL SOUNDING SHOW A BIT MORE SHEAR BY THIS TIME...ALTHOUGH INSTABILITY IS MODEST. ALTHOUGH STEERING FLOW IS BETTER THAN IN PREVIOUS DAYS...MOVING CELLS ALONG...SOME CONCERN EXISTS FOR REPEAT CELLS TRAINING EAST ALONG THE BOUNDARY RESULTING IN HEAVY RAINFALL. TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL...BUT NOT AS MUCH SO ALONG INTERSTATE 40 WHERE CLOUD COVER WILL BE BEST ALONG THE BOUNDARY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 115 PM EDT WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SUNDAY WITH PERSISTENT UPPER RIDGING TO OUR WEST AND BROAD UPPER TROFFING TO OUR NE. THE PATTERN IS EXPECTED TO FLATTEN OUT EARLY IN THE PERIOD BEFORE ANOTHER...DEEPER UPPER TROF DIGS DOWN OVER THE GREAT LAKES WITH THE TROF AXIS TO OUR NORTH BY THE END OF THE MEDIUM RANGE. THE LONG RANGE MODELS DIFFER A FAIR AMOUNT WRT THE EVOLUTION OF THE UPPER TROF WITH THE ECMWF DEVELOPING A MORE AMPLIFIED AND COHERENT SYSTEM COMPARED TO THE GFS. THE GFS TRIES TO DEVELOP THE TROF 1 TO 2 DAYS EARLIER AND KEEPS IT FARTHER NORTH AS IT PROGRESSES EASTWARD. DIURNAL POPS WERE INCREASED A BIT ON BOTH MON AND TUES NEXT WEEK TO REFLECT GENERALLY MORE MOIST GUIDANCE. OTHER THAN THAT...NO MAJOR CHANGES WERE MADE TO THE SENSIBLE FCST. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... AT KCLT...THE ATMOSPHERE APPEARS A BIT MORE UNSTABLE THAN THE EARLIER GUIDANCE LED ON...BASED ON CURRENT TRENDS. NUMEROUS SHRA/TSRA HAVE DEVELOPED ACRS THE SOUTHERN APPALACHIANS...AND THE VIS SAT IMAGERY SHOWS CUMULUS CONGESTUS INCREASING ACRS THE CAROLINA PIEDMONT. THE LATEST HRRR ALLOWS SEVERAL CELLS TO DEVELOP WHERE THIS CONGESTUS IS...SO I THINK THERE WILL BE A FEW STORMS AROUND KCLT THIS AFTN. ENUF TO WARRANT A TEMPO FOR TS. WINDS WILL BE LIGHT AND FAVOR A SW DIRECTION...EXCEPT NEAR TS...WHERE OUTFLOWS WILL BE VARIABLE. CONVECTION SHUD WANE QUICKLY THIS EVENING...WITH LIGHT WINDS AND CLEARING SKIES OVERNIGHT. NOT EXPECTING MUCH FOG POTENTIAL THURSDAY MORNING. ANOTHER ROUND OF DIURNAL SHRA/TSRA EXPECTING SIMILAR TO LAST FEW DAYS...BUT BEYOND THE 18Z TAF PERIOD FOR KCLT. ELSEWHERE...AS MENTIONED ABOVE...CONVECTION WILL BE MAIN CONCERN THIS AFTN. HAVE VCTS AND TEMPO GROUPS FOR TS AT ALL SITES...GIVEN THE SCATTERED NATURE OF STORMS. CHCS ARE STILL ONLY 20-30% FOR DIRECT IMPACT AT MOST SITES...WITH BEST CHC AT KAVL. CONVECTION WANES QUICKLY AFTER SUNSET. GUIDANCE SHOWING SOME FOG POTENTIAL AT KAVL...BUT OTHERWISE...NOT ENUF CONFIDENCE TO MENTION IN THE TAFS. WINDS WILL BE LIGHT...EXCEPT NEAR TSTMS. OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED THROUGH THE WEEK...WITH THE GREATEST COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF RECENT RAINFALL. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 91% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 97% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...STAARMANN NEAR TERM...ARK SHORT TERM...JAT LONG TERM...JPT AVIATION...ARK
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
648 PM CDT THU JUN 19 2014 .UPDATE... ADJUSTED POPS FOR THIS EVENING TO TRY TO TRIM BACK AREAL COVERAGE. THERE ARE A COUPLE OF ISOLATED STRONG STORMS AND SHOWERS AROUND THE REGION BUT MOST OF THE CWA IS DRY AND SUNNY. EXPECT ACTIVITY TO TAPER OFF AFTER SUNSET. SEE UPDATED AVIATION DISCUSSION BELOW. && .PREVIOUS DISCUSSION... .SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT TIGHT VORTICITY MAXIMA ROTATING OVER WESTERN SD AT THIS TIME HAS PRODUCED THUNDERSTORMS...WHICH WAS WHAT THE HRRR MODEL WAS INDICATING MOST OF THE DAY. SOME OF THESE STORMS HAVE BECOME SEVERE WITH HAIL AND EVEN REPORTS OF FUNNEL CLOUDS/LANDSPOUTS. NOT SURPRISING GIVEN COOLER TEMPS ALOFT AND TIGHT ROTATION OF VORT SPINNING ACROSS. MLCAPE VALUES GENERALLY RANGE FROM 500 TO 1000 J/KG WITH DEEP LAYER SHEAR 20 TO 30 KNOTS OVER WESTERN SD. ALTHOUGH...BETTER SHEAR VALUES EXIST OVER CENTRAL SD. HI RES MODELS SHOW SOME OF THIS ACTIVITY SPREADING ACROSS THE CWA AS LONG AS THE SUN IS UP. HAVE INCLUDED POPS THIS EVENING TO ACCOUNT FOR THIS. CONDITIONS QUIET DOWN LATE TONIGHT THROUGH FRIDAY NIGHT AS UPPER LEVEL FLOW BECOMES ZONAL. GIVEN 850 MB TEMPS ON FRIDAY...EXPECT HIGHS TO BE RATHER WARM WITH READINGS IN THE 80S. MORE ACTIVE WEATHER RETURNS TO THE AREA SATURDAY AND SATURDAY NIGHT. INSTABILITY INCREASES TO 2000 TO 3000 J/KG WITH 40 TO 50 KNOTS OF DEEP LAYER SHEAR. LOW LEVEL SHEAR NOT ALL TOO IMPRESSIVE. COULD BE SEEING SOME SEVERE STORMS ACROSS THE AREA SATURDAY INTO SATURDAY EVENING. .LONG TERM...SUNDAY THROUGH THURSDAY THE PERIOD STARTS OFF WITH FAIRLY FAST MOVING UPPER LEVEL FLOW WITH A SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE CENTRAL PLAINS EARLY IN THE PERIOD...PUTTING THE CWA IN A POTENTIAL SPOT FOR SHOWER AND THUNDERSTORM ACTIVITY SUNDAY THROUGH EARLY TUESDAY. HIGH PRESSURE DROPPING OVER THE NORTHERN PLAINS WILL KEEP THINGS DRY TUESDAY NIGHT AND WEDNESDAY...THEN MAY SEE ANOTHER CHANCE OF PRECIPITATION WEDNESDAY NIGHT AND THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES THE REGION. NEAR NORMAL TEMPERATURES WILL BE THE RULE THROUGH THE PERIOD...WITH HIGHS IN THE MID 70S TO LOWER 80S AND OVERNIGHT LOWS IN THE MID TO UPPER 50S. && .AVIATION... 00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE TAF PERIOD. A FEW ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA THIS EVENING...BUT DUE TO UNCERTAINTY OF DEVELOPMENT AND LOCATION...HAVE NOT MENTIONED ANY STORMS IN THE TAFS AT THIS TIME. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...WISE SHORT TERM...TMT LONG TERM...PARKIN AVIATION...WISE WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
621 PM CDT THU JUN 19 2014 .AVIATION... /00Z TAFS/ Messy forecast across the West Central Texas terminals over the next 24 hours, with a great deal of uncertainty. Weak system pushing northward up the Rio Grande may allow storms to redevelop and become more widespread across much of the area by around might and continue into the early morning hours. But not certain they will develop at all. To the west, a complex of storms will likely develop across the Panhandle and South Plains and push east this evening. But whether they reach Abilene, KABI, remains a huge question as well. For right now, will base the forecast on persistence from the last 24 to 48 hours, and add a VCTS mention to the forecast for the southernmost sites of Sonora/Junction/Brady where the storms seem most likely overnight. && .PREV DISCUSSION... /ISSUED 409 PM CDT THU JUN 19 2014/ SHORT TERM... (Tonight and Friday) Have a developing concern for heavy rainfall potential across our southern and possibly some central counties tonight. This is in association with a compact MCV, which appears on satellite imagery near Eagle Pass along the Rio Grande. This feature will move north-northwest and should enter our far southern counties (Sutton or Crockett Counties) toward Midnight. Low-level jet developing tonight will aid in low-level moisture transport. The Satellite Precipitation Estimates product from the NESDIS Satellite Analysis Branch has more details on the potential for locally heavy rain with this feature. Have increased PoPs across much of the southern half of our area, with a mention of locally heavy rainfall. The HRRR and TTU WRF both show development of convection across our soutern and some of our central counties tonight. PoPs may need to be raised further as radar trends become more apparent. To the northwest of our area, a gravity wave entering northwestern Texas ahead of a cold front could initiate thunderstorms late this afternoon and evening. The HRRR and TTU WRF models show a band of convection approaching our northwestern counties after 9 PM. With uncertainty in how much shower/thunderstorm coverage will occur away from the MCV, carrying lower PoPs across the rest of our area tonight. For Friday, carring low PoPs across West Central Texas. Models show a mid/upper level shear axis over our area, with precipitable water values between 1 and 1.6 inches. Little change in the temperature regime is expected. LONG TERM... (Friday night through next Thursday) Our area will remain under a weak mid/upper level shear axis through Saturday, as upper ridge begins to build over northwest Mexico into the Desert Southwest, and the upper high weakens over the lower Mississippi Valley. Have a slight chance PoP lingering across our western counties on Saturday. During the first half of next week, the upper high is progged to build over northwestern Mexico and the southwestern U.S., and weak northwest flow aloft will develop over our area. The forecast 850 mb temperatures indicate a gradual warming trend with daytime temperatures for our area. Weak surface cold front is progged to sag south of the Red River and stall Tuesday evening, The 12Z GFS suggests potential for convective complext to approach our area from the northwest Tuesday night. Did not make changes to our PoPs next week, but will monitor model trends. && .PRELIMINARY POINT TEMPS/POPS... Abilene 73 90 72 91 72 / 20 20 5 10 10 San Angelo 73 91 72 92 72 / 30 20 10 10 10 Junction 73 90 71 91 71 / 40 20 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
308 PM CDT WED JUN 18 2014 .DISCUSSION... GOOD SHOWER/THUNDERSTORM COVERAGE ACROSS PARTS OF SOUTHEAST SO FAR TODAY (MAINLY FROM THE HOUSTON AREA AND OFF TO THE NORTH AND NORTHEAST) HAS BEEN A LOT MORE THAN ANTICIPATED. RAIN GAUGE DATA HAS INDICATED RAINFALL TOTALS IN SOME SPOTS HAVE BEEN BETWEEN 1 AND 2 INCHES...MAINLY ASSOCIATED WITH THE STRONGER ACTIVITY AND WHERE NORTH-SOUTH TRAINING HAS SET UP. THE DISTURBANCE TO OUR SOUTHWEST THAT HAS HELPED GENERATE TODAY`S STORMS WILL BE FIGHTING WITH SOME DRIER AIR (CURRENTLY LOCATED ACROSS THE CENTRAL GULF OF MEXICO) THAT WILL BE SLOWLY EDGING WESTWARD TOWARD THE TEXAS COAST OVER THE NEXT COUPLE OF DAYS. MOST MODELS HAVE THE DRIER AIR WINNING OUT FOR THE REMAINDER OF THE WEEK...BUT THE SAME MODELS DID NOT GET TODAY RIGHT FOR OUR AREA. DECIDED TO KEEP LOW RAIN CHANCES IN THE FORECAST FOR THE REMAINDER OF THE WEEK WITH THE GENERAL IDEA OF POSSIBLE SHOWER DEVELOPMENT DURING THE LATE NIGHT THROUGH EARLY MORNING HOURS NEAR THE COAST...THEN POSSIBLE SHOWER/THUNDERSTORM DEVELOPMENT FURTHER INLAND AS THE DAY PROGRESSES. OVER THE WEEKEND...MID/UPPER LEVEL RIDGING THAT BUILDS ACROSS SOUTHEAST TEXAS MIGHT NOT END UP BEING STRONG ENOUGH TO TOTALLY SHUT DOWN OUR RAINS...AND WE MIGHT END UP NEEDING TO ADD LOW POPS FOR MAINLY DAYTIME DEVELOPMENT. WILL HAVE RAIN COME BACK INTO THE FORECAST FOR THE START OF NEXT WEEK AS RIDGING BREAKS DOWN. 42 && .MARINE... A SMALL CRAFT EXERCISE CAUTION WILL AGAIN BE IN EFFECT THIS EVENING UNTIL 4 AM TOMORROW MORNING. HIGH PRESSURE BEGINS TO MOVE CLOSER TO THE AREA TOMORROW THOUGH WHICH WILL ALLOW THE PRESSURE GRADIENT TO RELAX ALONG WITH THE SURFACE WINDS. LIGHT TO OCCASIONALLY MODERATE WINDS WITH 2 TO 4 FOOT SEAS WILL CONTINUE THROUGH THE WEEKEND. 23 && .PREV DISCUSSION... /ISSUED 1142 AM CDT WED JUN 18 2014/ DISCUSSION... SEE AVIATION FOR 18Z TAF ISSUANCE. AVIATION... SHOWERS AND THUNDERSTORMS HAVE CONTINUED TO INCREASE IN COVERAGE THIS AFTERNOON THANKS TO AMPLE MOISTURE AND LIFT FROM A SHORTWAVE WEST OF THE AREA. FORECAST SOUNDINGS ALSO SUPPORT RAIN THIS AFTERNOON AS PWATS ARE FORECASTED TO BE AROUND 1.70". THE HRRR... TEXAS TECH WRF... AND RAP ALSO INDICATE THE CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. ANOTHER NIGHT OF MVFR CIGS LOOKS POSSIBLE TOMORROW MORNING THANKS TO LINGERING MOISTURE. FOR THURSDAY THE CHANCE OF RAIN LOOKS TO DIMINISH AS MUCH DRIER 850/500 AIR WORKS INTO THE AREA. THERE MIGHT BE A CHANCE OF SOME SHOWERS IN THE MORNING BEFORE THE DRIER AIR ARRIVES BUT CHANCES LOOK LOW. PWATS ARE FORECASTED TO DROP NEAR 1.20" BY TOMORROW EVENING ACROSS THE AREA (AVERAGE VALUES IS ~1.60" FOR THIS TIME OF YEAR). 23 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 74 92 74 93 74 / 30 20 10 20 10 HOUSTON (IAH) 76 91 75 92 75 / 30 20 10 20 10 GALVESTON (GLS) 80 88 80 89 80 / 20 20 20 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM... WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...42 AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1142 AM CDT WED JUN 18 2014 .DISCUSSION... SEE AVIATION FOR 18Z TAF ISSUANCE. && .AVIATION... SHOWERS AND THUNDERSTORMS HAVE CONTINUED TO INCREASE IN COVERAGE THIS AFTERNOON THANKS TO AMPLE MOISTURE AND LIFT FROM A SHORTWAVE WEST OF THE AREA. FORECAST SOUNDINGS ALSO SUPPORT RAIN THIS AFTERNOON AS PWATS ARE FORECASTED TO BE AROUND 1.70". THE HRRR... TEXAS TECH WRF... AND RAP ALSO INDICATE THE CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. ANOTHER NIGHT OF MVFR CIGS LOOKS POSSIBLE TOMORROW MORNING THANKS TO LINGERING MOISTURE. FOR THURSDAY THE CHANCE OF RAIN LOOKS TO DIMINISH AS MUCH DRIER 850/500 AIR WORKS INTO THE AREA. THERE MIGHT BE A CHANCE OF SOME SHOWERS IN THE MORNING BEFORE THE DRIER AIR ARRIVES BUT CHANCES LOOK LOW. PWATS ARE FORECASTED TO DROP NEAR 1.20" BY TOMORROW EVENING ACROSS THE AREA (AVERAGE VALUES IS ~1.60" FOR THIS TIME OF YEAR). 23 && .PREV DISCUSSION... /ISSUED 1019 AM CDT WED JUN 18 2014/ DISCUSSION... FOR THE MORNING UPDATE...WENT AHEAD AND RAISED TODAY`S RAIN CHANCES A LITTLE BIT TO ACCOUNT FOR CURRENT ACTIVITY SHOWING UP ON RADAR AND HIGH PRECIPITABLE WATER VALUES IN THE AREA. WITH DAYTIME HEATING ANTICIPATE MORE SHOWER/THUNDERSTORM DEVELOPMENT THAT WILL WORK ITS WAY NORTHWARD ACROSS OUR AREA. FORECAST UPDATE IS ALREADY OUT. 42 PREV DISCUSSION... /ISSUED 658 AM CDT WED JUN 18 2014/ DISCUSSION... 12Z TAF DISCUSSION IN AVIATION SECTION. AVIATION... MAINLY VFR CIGS ACROSS SE TX TERMINALS WITH THE EXCEPTION BEGIN CLL. IFR/MVFR CIGS AT CLL SHOULD BE SHORT LIVED. CEILINGS SHOULD LIFT NEXT HOUR OR TWO WITH HEATING. RADAR SHOWS A FEW ISO SHOWERS BUT DO NOT EXPECT ACTIVITY TO DEVELOP OR BECOME MORE WIDESPREAD. CARRY VFR CIGS IN THE AFTERNOON AND THEN REPEAT CONDITIONS FOR TONIGHT. WINDS MAY NOT BE AS STRONG GOING INTO THURSDAY. 39 PREV DISCUSSION... /ISSUED 411 AM CDT WED JUN 18 2014/ DISCUSSION... A MID AND UPPER LEVEL WEAK HIGH PRESSURE RIDGE WAS LOCATED OVER THE UPPER TEXAS COASTAL AREAS EARLY THIS MORNING. ONSHORE FLOW WAS PERSISTENT OVER THE LOWER LEVELS AND SURFACE. A WEAK VORTICITY MAXIMUM WAS MOVING ACROSS SOUTH TEXAS. THE MODELS PICKED UP ON THIS SYSTEM AND MOVE IT INTO THE WESTERN COUNTIES OF THE FORECAST AREA LATER THIS AFTERNOON. THE HIGH RESOLUTION MODELS ARE FAIRLY CONSISTENT IN KEEPING ONLY ISOLATED COVERAGE OVER SE TX TODAY. THE COVERAGE ACTUALLY LOOKS TO BE SIMILAR TO YESTERDAY...WITH ISOLATED CHANCES OVER THE SOUTH THIS MORNING AND WITH THE COVERAGE MAINLY OVER THE NORTHERN COUNTIES THIS AFTERNOON. THE MODEL FORECAST SOUNDINGS BEAR THIS REASONING OUT WITH BEST PW/S AT OR ABOVE 1.8 INCHES AT KCLL DURING THE LATE AFTERNOON. THE MID LEVEL RIDGE THEN BUILDS OVER THE AREA TOMORROW THROUGH THE END OF THE WEEK. THE AIRMASS DRIES OUT AS WELL AS CAN BE SEEN IN THE PW FIELDS AND IN THE 700 MB DEWPOINT FORECASTS ON THE GFS AND ECMWF MODELS. THIS WILL LEAD TO LOW RAIN CHANCES BEGINNING ON THURSDAY...AND A SLIGHT INCREASE IN DAILY TEMPERATURES BY SATURDAY. EARLY NEXT WEEK THE GFS AND ECMWF DEVELOP A WEAKNESS IN THE RIDGE OVER THE AREA. THE AREA OF MOISTURE OVER THE EASTERN AND CENTRAL GULF TRIES TO WORK ITS WAY TO THE WEST...BUT THE 00Z MODEL RUNS KEEP IT MAINLY OFF THE TEXAS COAST. FOR NOW...SLIGHTLY COOLER TEMPERATURES ARE POSSIBLE EARLY NEXT WEEK WHILE RAIN CHANCES WILL PROBABLY HOLD OFF UNTIL THE MID WEEK PERIOD. MARINE... SMALL CRAFT EXERCISE CAUTION SHOULD PERSIST INTO THE MORNING HOURS FOR THE OFFSHORE WATERS AND BAYS OF THE UPPER TX COAST. PRESSURE GRADIENT DOES LOOK TO RELAX SOME THE NEXT COUPLE OF DAYS SO THE NOCTURNAL INCREASE IN WINDS MAY NOT BE AS MUCH TONIGHT INTO THURSDAY. POSSIBLE TO HAVE ONE MORE NIGHT OF SCEC CONDITIONS BUT LIKELY SEE WINDS REMAIN CLOSER TO 10-15KTS WITH SLIGHTLY LOWER SEAS. WINDS AND SEAS SHOULD DECREASE FURTHER FOR THE WEEKEND AS PRESSURE GRADIENT LESSENS FURTHER. OVERALL TYPICAL SUMMER TIME PATTERN WILL CONTINUE. 39 AVIATION... SO FAR LOOKING AT VFR CIGS THIS MORNING WITH PERHAPS SOME ISOLATED AREAS OF MVFR. RADAR STARTING TO SHOW SOME SHOWERS DEVELOPING BUT LESS THAN YESTERDAY. TAFS SHOULD BE ON TRACK AND LOOK FOR SIMILAR CONDITIONS THE NEXT 24 HRS. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 74 92 73 93 73 / 10 10 10 10 10 HOUSTON (IAH) 76 91 75 92 74 / 10 10 10 10 10 GALVESTON (GLS) 80 88 79 89 80 / 10 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM 5 PM CDT THIS AFTERNOON THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...23 AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
148 PM EDT WED JUN 18 2014 .SYNOPSIS... HIGH PRESSURE COVERED MUCH OF THE SOUTHEAST UNITED STATES TODAY. A COLD EXTENDED FROM NEW YORK INTO WISCONSIN. THIS FRONT WILL MOVE SOUTH THROUGH THE OHIO VALLEY AND MID ATLANTIC REGION ON THURSDAY...THEN STALL OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1200 PM EDT WEDNESDAY... INCREASED THE POPS SLIGHTLY ACROSS THE SOUTHWEST AS ISOLATED THUNDERSTORMS ARE BEGINNING TO POP UP ACROSS RUSSELL COUNTY AND FURTHER BACK ACROSS PIKE COUNTY. HRRR 12Z RUN CONTINUES TO FAVOR SOME DEVELOPMENT ACROSS THE SOUTHWEST AND EAST OF THE BLUE RIDGE ACROSS SOUTHSIDE AND THE PIEDMONT LATER THIS AFTERNOON AND EVENING. WITH SURFACE TEMPS IN THE LOW 90S THIS AFTERNOON AND MU CAPES AROUND 2000 J/KG THE POSSIBILITY WILL EXIST FOR SOME ISOLATED SEVERE STORMS ONCE AGAIN TODAY. LARGE HAIL WOULD BE THE PRIMARY THREAT. STORM MOTION OF 10 KTS IS ONLY SLIGHTLY FASTER THAN YESTERDAY...SO SLOW MOVING STORMS WILL HAVE TO BE WATCHED FOR POSSIBLE FLOODING ESPECIALLY IF ANY STORM CROSSES AN AREA THAT RECEIVED DECENT RAINFALL YESTERDAY. AS OF 840 AM EDT WEDNESDAY... REMOVED FOG FROM THE GRIDS AS DAYTIME HEATING HAS QUICKLY ERODED THE PATCHY FOG THAT WAS STILL HANGING AROUND. ALSO TWEAKED THE NEAR TERM TEMPS AND DEWPTS. ALL OTHER PREVIOUS FORECAST DETAILS REMAIN ON TRACK. AS OF 400 AM EDT WEDNESDAY... TEMPERATURES WERE UNSEASONABLY WARM FROM THE SURFACE THROUGH MID LEVELS OF THE ATMOSPHERE. 00Z/850MB TEMPERATURES WERE +20C AT BLACKSBURG TUESDAY EVENING AND ARE EXPECTED TO BE AT LEAST THAT WARM AGAIN TODAY. 700MB TEMPERATURES WILL REMAIN IN THE +8 TO +10 RANGE. WITH THAT POCKET OF MID LEVEL WARM AIR ACROSS THE OHIO VALLEY INTO NORTHERN VIRGINIA...THE BETTER PROBABILITY OF THUNDERSTORMS WILL AGAIN BE IN THE SOUTHERN PART OF THE FORECAST AREA THIS AFTERNOON AND EVENING. OVERALL SYNOPTIC PATTERN HAS FORECAST AREA UNDER A 591DM RIDGE WITH NO TRIGGERS FOR SHOWERS AND THUNDERSTORMS. THIS MEANS WEAK LEE SURFACE TROF AND OROGRAPHICS WILL AGAIN BE THE DOMINANT FORCING FOR SHOWERS AND THUNDERSTORMS AGAIN THIS AFTERNOON AND EVENING. EXPECTING BEST COVERAGE OF STORMS TO BE SIMILAR TO TUESDAY. BUFKIT SHOWED THE CAP BREAKING AND SOUNDINGS REACHING CONVECTIVE TEMPERATURE AROUND 18Z/2PM THIS AFTERNOON. CAPES WILL REACH ABOUT 2000 TO 2500 J/KG. USED WARMER MET GUIDANCE AS BASIS FOR MAXIMUM TEMPERATURES TODAY AND MINIMUM TEMPERATURES TONIGHT. THIS IS THE BEST CHANCE WE HAVE SEEN SO FAR THIS SEASON FOR A LEMONADE DAY IN BLUEFIELD WV. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 330 AM EDT WEDNESDAY... AN UPPER LEVEL TROUGH MOVES EAST INTO NEW ENGLAND THURSDAY AND PUSHES INTO THE ATLANTIC OCEAN BY FRIDAY NIGHT. THE UPPER ANTICYCLONE RETROGRADES WESTWARD AND THIS WILL ALLOW A WAVY BACKDOOR COLD FRONT TO MAKE A RUN AT OUR AREA. OVERALL...EXPECT GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS DURING THIS TIME FRAME. THE ADDED CONCERNS ARE WHETHER ANY REMNANT MCV TRACK EAST SOUTHEAST TOWARD OUR FORECAST AREA. MOISTURE WILL BE INCREASING WITH PW VALUES RISING FROM 1.16 INCHES ON 00Z/17TH RNK RAOB TO AROUND 1.75 INCHES. WITH SOME HEATING...WE COULD GENERATE SOME BETTER INSTABILITY. THE RESULT SHOULD BE SLOW-MOVING WET STORM CLUSTERS CAPABLE OF PRODUCING HAIL AND VERY HEAVY RAINFALL. TEMPERATURES WILL REMAIN ABOVE NORMAL FOR THIS PERIOD WITH HIGHS FROM THE LOWER 80S IN THE MOUNTAINS TO THE MID 90S IN THE PIEDMONT. LOW TEMPERATURES WILL GENERAL BE IN THE 60S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 245 PM EDT TUESDAY... FOR SAT THROUGH SUN NIGHT: WE STAY IN A GENTLY CYCLONIC BUT LIGHT NORTHWESTERLY MID LEVEL FLOW... ON THE SOUTHWEST SIDE OF THE LARGE VORTEX WOBBLING OVER THE CANADIAN MARITIMES. THE COMPACT MID LEVEL LOW EXPECTED TO TRACK ROUGHLY EASTWARD NEAR THE CENTRAL US/CANADA BORDER LATE IN THE WORK WEEK WILL WEAKEN AND GRADUALLY SHEAR AS IT CROSSES THE UPPER MIDWEST OVER THE WEEKEND (WITH VARYING SPEEDS AMONG THE MODELS SOLUTIONS). PROPELLED BY ENERGY ROTATING AROUND THE SOUTH SIDE OF THE EASTERN CANADA VORTEX... THE SURFACE BACKDOOR FRONTAL ZONE IS EXPECTED TO DIP A BIT FURTHER SOUTHWEST TOWARD THE CWA OVER THE WEEKEND... HOLDING TO OUR NE BUT CLOSE ENOUGH TO PROVIDE A PATH FOR MID LEVEL PERTURBATIONS TO TRAVERSE THE REGION... SPAWNING GOOD COVERAGE OF SHOWERS AND STORMS... WITH GREATEST COVERAGE FOCUSED DURING (BUT NOT LIMITED TO) THE TYPICAL DIURNAL TIME WINDOWS. THE GFS AND ECMWF INDICATE THAT THE HIGHEST SHOWERS/STORM CHANCES WILL BE SAT MIDDAY THROUGH AFTERNOON. THICKNESSES REMAIN 5-15 M ABOVE NORMAL... SO WILL HOLD ONTO HIGHS IN THE 80S TO LOWER 90S... WITH CONFIDENCE REDUCED BY POTENTIAL EARLY- DAY CONVECTION LIMITING HEATING ESPECIALLY ON SAT. FOR MON/TUE: MORE OF THE SAME... WITH A SLOW WNW FLOW PATTERN WITH WEAK IMPULSES TRACKING ROUGHLY EASTWARD ACROSS THE CWA (BETWEEN THE MARITIME VORTEX RETREATING NORTHWARD AND THE BUILDING RIDGE OVER AND JUST OFF THE SOUTHEAST COAST)... SOUTH OF AN INCREASINGLY DIFFUSE FRONTAL ZONE JUST NORTH OF THE OH VALLEY. EXPECT A CONTINUED THREAT OF SCATTERED SLOW-MOVING SHOWERS AND STORMS... AGAIN PRIMARILY (BUT NOT ONLY) OCCURRING DURING THE AFTERNOON INTO EARLY EVENING. THE GFS REMAINS THE STRONGEST WITH THE UPPER-MIDWEST WAVE AS IT CROSSES MI... PLACING THE CWA IN A BIT STRONGER MID LEVEL FLOW WITH GREATER MOISTURE POOLING SOUTH OF THE FRONTAL ZONE AND THUS MUCH GREATER COVERAGE OF SHOWERS/STORMS. LEANED POPS TOWARDS GFS FOR TUESDAY WITH MENTION OF LIKELY. THIS PATTERN FAVORS TEMPERATURES CONTINUING SLIGHTLY ABOVE NORMAL. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 140 PM EDT WEDNESDAY... ISOLATED CONVECTION EXPECTED AGAIN THIS AFTERNOON...WITH MOST FAVORED LOCATIONS BEING SRN WV/SW VA INTO SOUTHSIDE VA. FOR TAFS...HAVE VCTS IN AT BLF/BCB/ROA AND DAN. THINK CONVECTION WANES EARLY EVENING. MAINLY LOOKING AT VFR SCT TO BKN CU/TCU WITH SOME CBS. TONIGHT...SYSTEM UPSTREAM OVER NRN IL/INDIANA MAY SPILL MORE CLOUDS TOWARD THE MTNS BY DAWN WHICH COULD PRECLUDE ANY FOG FORMATION...THEREFORE LEFT FOG OUT OF LWB. THINK BCB WILL SEE A PERIOD OF MVFR VSBYS AROUND 09-12Z...BEFORE CLOUDS MOVE IN. THURSDAY MORNING...THINK SHRA/TSRA WILL BE CLOSING IN ON SE WV SO ADDED VCTS BACK IN AT LWB/BLF AROUND 15Z. EXTENDED AVIATION DISCUSSION... A BACKDOOR FRONT DIPS SOUTH TOWARD THE AREA FROM THE MASON-DIXON LINE THURSDAY AFTERNOON WHICH WILL INCREASE THE RANGE OF STORMS INTO MORE SCATTERED AND MULTICELLULAR AS OPPOSED TO PULSE. THE FRONT IS EXPECTED TO PRODUCE BETTER COVERAGE THROUGH THU NIGHT AND POTENTIALLY INTO FRIDAY. A WEAK FLOW PATTERN HOLDING OVER THE WEEKEND WILL KEEP THE STORM CHANCES EACH AFTERNOON THROUGH EARLY EVENING SAT/SUN. AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING... PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE AFTERNOON CONVECTION REDEVELOPS. && .CLIMATE... AS OF 420 AM EDT TUESDAY... LOCATIONS RECORD HIGHS TODAY (6/18) ROANOKE 97/1925 LYNCHBURG 96/1944 DANVILLE 96/2007 BLACKSBURG 88/2007 BLUEFIELD 90/2007 LEWISBURG 88/2007 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/CF SHORT TERM...KK LONG TERM...KK AVIATION...AMS/PM/WP CLIMATE...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1219 PM EDT WED JUN 18 2014 .SYNOPSIS... HIGH PRESSURE COVERED MUCH OF THE SOUTHEAST UNITED STATES TODAY. A COLD EXTENDED FROM NEW YORK INTO WISCONSIN. THIS FRONT WILL MOVE SOUTH THROUGH THE OHIO VALLEY AND MID ATLANTIC REGION ON THURSDAY...THEN STALL OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1200 PM EDT WEDNESDAY... INCREASED THE POPS SLIGHTLY ACROSS THE SOUTHWEST AS ISOLATED THUNDERSTORMS ARE BEGINNING TO POP UP ACROSS RUSSELL COUNTY AND FURTHER BACK ACROSS PIKE COUNTY. HRRR 12Z RUN CONTINUES TO FAVOR SOME DEVELOPMENT ACROSS THE SOUTHWEST AND EAST OF THE BLUE RIDGE ACROSS SOUTHSIDE AND THE PIEDMONT LATER THIS AFTERNOON AND EVENING. WITH SURFACE TEMPS IN THE LOW 90S THIS AFTERNOON AND MU CAPES AROUND 2000 J/KG THE POSSIBILITY WILL EXIST FOR SOME ISOLATED SEVERE STORMS ONCE AGAIN TODAY. LARGE HAIL WOULD BE THE PRIMARY THREAT. STORM MOTION OF 10 KTS IS ONLY SLIGHTLY FASTER THAN YESTERDAY...SO SLOW MOVING STORMS WILL HAVE TO BE WATCHED FOR POSSIBLE FLOODING ESPECIALLY IF ANY STORM CROSSES AN AREA THAT RECEIVED DECENT RAINFALL YESTERDAY. AS OF 840 AM EDT WEDNESDAY... REMOVED FOG FROM THE GRIDS AS DAYTIME HEATING HAS QUICKLY ERODED THE PATCHY FOG THAT WAS STILL HANGING AROUND. ALSO TWEAKED THE NEAR TERM TEMPS AND DEWPTS. ALL OTHER PREVIOUS FORECAST DETAILS REMAIN ON TRACK. AS OF 400 AM EDT WEDNESDAY... TEMPERATURES WERE UNSEASONABLY WARM FROM THE SURFACE THROUGH MID LEVELS OF THE ATMOSPHERE. 00Z/850MB TEMPERATURES WERE +20C AT BLACKSBURG TUESDAY EVENING AND ARE EXPECTED TO BE AT LEAST THAT WARM AGAIN TODAY. 700MB TEMPERATURES WILL REMAIN IN THE +8 TO +10 RANGE. WITH THAT POCKET OF MID LEVEL WARM AIR ACROSS THE OHIO VALLEY INTO NORTHERN VIRGINIA...THE BETTER PROBABILITY OF THUNDERSTORMS WILL AGAIN BE IN THE SOUTHERN PART OF THE FORECAST AREA THIS AFTERNOON AND EVENING. OVERALL SYNOPTIC PATTERN HAS FORECAST AREA UNDER A 591DM RIDGE WITH NO TRIGGERS FOR SHOWERS AND THUNDERSTORMS. THIS MEANS WEAK LEE SURFACE TROF AND OROGRAPHICS WILL AGAIN BE THE DOMINANT FORCING FOR SHOWERS AND THUNDERSTORMS AGAIN THIS AFTERNOON AND EVENING. EXPECTING BEST COVERAGE OF STORMS TO BE SIMILAR TO TUESDAY. BUFKIT SHOWED THE CAP BREAKING AND SOUNDINGS REACHING CONVECTIVE TEMPERATURE AROUND 18Z/2PM THIS AFTERNOON. CAPES WILL REACH ABOUT 2000 TO 2500 J/KG. USED WARMER MET GUIDANCE AS BASIS FOR MAXIMUM TEMPERATURES TODAY AND MINIMUM TEMPERATURES TONIGHT. THIS IS THE BEST CHANCE WE HAVE SEEN SO FAR THIS SEASON FOR A LEMONADE DAY IN BLUEFIELD WV. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 330 AM EDT WEDNESDAY... AN UPPER LEVEL TROUGH MOVES EAST INTO NEW ENGLAND THURSDAY AND PUSHES INTO THE ATLANTIC OCEAN BY FRIDAY NIGHT. THE UPPER ANTICYCLONE RETROGRADES WESTWARD AND THIS WILL ALLOW A WAVY BACKDOOR COLD FRONT TO MAKE A RUN AT OUR AREA. OVERALL...EXPECT GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS DURING THIS TIME FRAME. THE ADDED CONCERNS ARE WHETHER ANY REMNANT MCV TRACK EAST SOUTHEAST TOWARD OUR FORECAST AREA. MOISTURE WILL BE INCREASING WITH PW VALUES RISING FROM 1.16 INCHES ON 00Z/17TH RNK RAOB TO AROUND 1.75 INCHES. WITH SOME HEATING...WE COULD GENERATE SOME BETTER INSTABILITY. THE RESULT SHOULD BE SLOW-MOVING WET STORM CLUSTERS CAPABLE OF PRODUCING HAIL AND VERY HEAVY RAINFALL. TEMPERATURES WILL REMAIN ABOVE NORMAL FOR THIS PERIOD WITH HIGHS FROM THE LOWER 80S IN THE MOUNTAINS TO THE MID 90S IN THE PIEDMONT. LOW TEMPERATURES WILL GENERAL BE IN THE 60S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 245 PM EDT TUESDAY... FOR SAT THROUGH SUN NIGHT: WE STAY IN A GENTLY CYCLONIC BUT LIGHT NORTHWESTERLY MID LEVEL FLOW... ON THE SOUTHWEST SIDE OF THE LARGE VORTEX WOBBLING OVER THE CANADIAN MARITIMES. THE COMPACT MID LEVEL LOW EXPECTED TO TRACK ROUGHLY EASTWARD NEAR THE CENTRAL US/CANADA BORDER LATE IN THE WORK WEEK WILL WEAKEN AND GRADUALLY SHEAR AS IT CROSSES THE UPPER MIDWEST OVER THE WEEKEND (WITH VARYING SPEEDS AMONG THE MODELS SOLUTIONS). PROPELLED BY ENERGY ROTATING AROUND THE SOUTH SIDE OF THE EASTERN CANADA VORTEX... THE SURFACE BACKDOOR FRONTAL ZONE IS EXPECTED TO DIP A BIT FURTHER SOUTHWEST TOWARD THE CWA OVER THE WEEKEND... HOLDING TO OUR NE BUT CLOSE ENOUGH TO PROVIDE A PATH FOR MID LEVEL PERTURBATIONS TO TRAVERSE THE REGION... SPAWNING GOOD COVERAGE OF SHOWERS AND STORMS... WITH GREATEST COVERAGE FOCUSED DURING (BUT NOT LIMITED TO) THE TYPICAL DIURNAL TIME WINDOWS. THE GFS AND ECMWF INDICATE THAT THE HIGHEST SHOWERS/STORM CHANCES WILL BE SAT MIDDAY THROUGH AFTERNOON. THICKNESSES REMAIN 5-15 M ABOVE NORMAL... SO WILL HOLD ONTO HIGHS IN THE 80S TO LOWER 90S... WITH CONFIDENCE REDUCED BY POTENTIAL EARLY- DAY CONVECTION LIMITING HEATING ESPECIALLY ON SAT. FOR MON/TUE: MORE OF THE SAME... WITH A SLOW WNW FLOW PATTERN WITH WEAK IMPULSES TRACKING ROUGHLY EASTWARD ACROSS THE CWA (BETWEEN THE MARITIME VORTEX RETREATING NORTHWARD AND THE BUILDING RIDGE OVER AND JUST OFF THE SOUTHEAST COAST)... SOUTH OF AN INCREASINGLY DIFFUSE FRONTAL ZONE JUST NORTH OF THE OH VALLEY. EXPECT A CONTINUED THREAT OF SCATTERED SLOW-MOVING SHOWERS AND STORMS... AGAIN PRIMARILY (BUT NOT ONLY) OCCURRING DURING THE AFTERNOON INTO EARLY EVENING. THE GFS REMAINS THE STRONGEST WITH THE UPPER-MIDWEST WAVE AS IT CROSSES MI... PLACING THE CWA IN A BIT STRONGER MID LEVEL FLOW WITH GREATER MOISTURE POOLING SOUTH OF THE FRONTAL ZONE AND THUS MUCH GREATER COVERAGE OF SHOWERS/STORMS. LEANED POPS TOWARDS GFS FOR TUESDAY WITH MENTION OF LIKELY. THIS PATTERN FAVORS TEMPERATURES CONTINUING SLIGHTLY ABOVE NORMAL. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... AS OF 730 AM EDT WEDNESDAY... SATELLITE PICTURES SHOWED PATCHY FOG ALONG THE GREENBRIER RIVER THIS MORNING. THE VFR FOG AT KLWB WILL ERODE SHORTLY AFTER THE BEGINNING OF THE 12Z TAF PERIOD. EXPECT STORMS WILL DEVELOP ALONG BLUE RIDGE AND IN ADJACENT FOOTHILLS SOUTH OF ROANOKE THIS AFTERNOON. HARD TO PLACE EXACT TRACK OF THE ISOLATED STORMS SO WILL STICK WITH VCTS MENTIONS DURING THE MID TO LATE AFTERNOON. LOCALIZED IFR CONDITIONS WILL BE IN/NEAR STORMS AFTER 19Z/3PM WEDNESDAY. LOW CONFIDENCE FOR FOG DEVELOPMENT AGAIN TONIGHT. HAVE LEFT FOG OUT OF THE TAFS FOR NOW UNTIL WE KNOW WHICH AIRPORTS GET RAIN THIS AFTERNOON. EXTENDED AVIATION DISCUSSION... A TYPICAL SUMMER PATTERN IS ANTICIPATED THROUGH THE UPCOMING WEEKEND... WITH THE GREATEST AVIATION THREATS BEING THE SCATTERED DAYTIME CONVECTION AND THE ATTENDANT STRONG VARIABLE/GUSTY WINDS AND POSSIBLE HAIL. A BACKDOOR FRONT DIPS SOUTH TOWARD THE AREA FROM THE MASON-DIXON LINE. THE FRONT IS EXPECTED TO PRODUCE BETTER COVERAGE OF STORMS THURSDAY AFTERNOON LASTING THROUGH THU NIGHT AND POTENTIALLY INTO FRIDAY. A WEAK FLOW PATTERN HOLDING OVER THE WEEKEND WILL KEEP THE STORM CHANCES EACH AFTERNOON THROUGH EARLY EVENING SAT/SUN. AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING... PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE AFTERNOON CONVECTION REDEVELOPS. && .CLIMATE... AS OF 420 AM EDT TUESDAY... LOCATIONS RECORD HIGHS TODAY (6/18) ROANOKE 97/1925 LYNCHBURG 96/1944 DANVILLE 96/2007 BLACKSBURG 88/2007 BLUEFIELD 90/2007 LEWISBURG 88/2007 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/CF SHORT TERM...KK LONG TERM...KK AVIATION...AMS/PM CLIMATE...AMS/JH Area Forecast Discussion National Weather Service Spokane WA 848 PM PDT THU JUN 19 2014 .SYNOPSIS... Warmer...drier and more summer-like conditions will return to the entire Inland NORTHWEST for the rest of the week, the weekend and into the very early part of next week. Expect breezy winds and a chance of showers and afternoon mountain thunderstorms Friday and again next week. && .DISCUSSION... The forecast has been updated to add a slight chance of thunderstorms for the Camas Prairie and southeast Shoshone County Friday morning, as well as increase sky cover. Also given current relative humidities and expected increase in mid/high level clouds tonight...patchy fog is no longer expected and was removed. Water Vapor and Infrared Satellite imagery as of 830 pm showed a well defined front stretching from NW Washington down to just off the Oregon coast. Rain has been falling along this front...but models are in good agreement that as the low near the north tip of Vancouver Island lifts north and weakens tonight...that the front will rapidly weaken as it crosses the Cascades. This combined with downslope westerly winds as the front crosses should leave areas outside of the Cascade crest generally dry with passing mid/high clouds with one exception. The past couple NAM model runs as well as the HRRR show elevated convection developing over the Camas Prairie near 12z (5 am Friday) as a band of elevated lift and instability moved up into the area ahead of the front. With the 00z NAM model showing 0-6km Most Unstable CAPE values of 200 J/KG with the CAPE layer extending from 700mb up to near 300mb...its possible isolated lightning strikes could fall out of this. If storms develop they would be high based and fast moving...with light rainfall amounts. The GFS is not as excited about this...but typically these elevated convection cases ahead of a front have shown the NAM have the edge over the GFS. JW && .AVIATION... 00Z TAFS: A weak front will result in mainly mid and high clouds spreading into the region from west to east tonight and Friday. Main impact from this front will be increased west-southwest winds on Friday with gusts 15-25 kts common with the strongest gusts expected at KEAT, KGEG. Late tonight a band of elevated moisture/instabilty may produce some mid level cumulus clouds around KLWS/KPUW. The NAM model suggests a small chance of these developing into storms but most model data suggests better chances will be south of KLWS so left this TAF free of TS. Friday afternoon isolated thunderstorms are possible over the Idaho Panhandle (mainly east of KCOE) and far NE Washington (north of KGEG) so these TAF sites were also left dry. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 52 76 50 75 48 82 / 0 10 0 0 0 0 Coeur d`Alene 49 76 48 75 48 82 / 0 10 10 0 0 0 Pullman 49 74 46 74 43 79 / 10 10 10 0 0 0 Lewiston 56 83 52 82 50 88 / 10 10 10 0 0 0 Colville 50 78 47 79 48 82 / 10 10 10 0 0 0 Sandpoint 46 75 46 75 44 83 / 10 20 10 0 0 0 Kellogg 48 73 48 74 46 79 / 0 20 20 10 10 10 Moses Lake 57 80 51 79 53 85 / 0 0 0 0 0 0 Wenatchee 61 79 51 80 54 87 / 0 0 0 0 0 0 Omak 54 81 48 80 47 85 / 10 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
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Area Forecast Discussion National Weather Service Spokane WA 438 AM PDT WED JUN 18 2014 .SYNOPSIS... Light rain will continue over the Idaho Panhandle and extreme eastern Washington through this morning. A drying trend will begin this afternoon with only a few lingering showers over the Panhandle tonight. Warmer...drier and more summer-like conditions will envelop the region for the rest of the week with a small chance of afternoon thunderstorms mainly over the mountains through the weekend. && .DISCUSSION... Wednesday: A deep low pressure system currently spinning over southwestern Montana will begin to track east this afternoon. The steady stream of moisture and vort max`s wrapping around its backside will finally get pulled east of the ID/MT border and rain will come to an end today following almost 24-30 hours of straight rainfall. This will be a rather slow drying trend with steady rain likely to linger through much of the morning before giving way to scattered light showers during the afternoon hours. 2AM radar and satellite confirms two last vorticity maximums will pass through the Inland NW before the storm system drifts east. One is driving moderate rains across SE WA while a second is making its way into Nrn ID from NW Montana. Timing utilizing the HRRR and satellite extrapolation suggest steady rain will end in the north (NE WA/Nrn ID) around 8AM and south (Palouse, Blues, L-C Valley, Camas Prairie) roughly 11AM. Confidence is not as high for the Central Panhandle Mtns of ID, especially along the immediate MT border which looks be clipped by one last wave of moisture during the afternoon hours. As the steady precipitation ends, sunbreaks will help destabilize the atmosphere promoting a renewed threat for showers. 500mb warming suggest any convection will be shallow but given the saturated boundary layer now in place, it even shallow convection could yield another tenth of an inch. May even get a stray thunderstorm across the northeastern mountains. Weak high pressure will begin building into the region Wednesday night and continue on Thursday. There is a good possibility that fog forms in the northeastern valleys of WA and Nrn ID after these soaking rains but coverage is still somewhat uncertain due to a light push of w/sw winds behind today`s storm system and possibility for lingering cloud cover. Spring will return to the Inland NW on Thursday under the shortwave ridging. There should be a good deal of sunshine in the morning giving way to fair afternoon cumulus and temperatures will return to seasonal normals. /sb Thursday night through Sunday...Model agreement is decent and consistent in placing the forecast area in a sustained southwest flow regime under the southeast flank of a stationary Gulf of Alaska closed low. This pattern typically argues for generally dry conditions in the basin with a small chance of afternoon and evening thunderstorms over the mountains north and east of the basin. There do not appear to be any significant waves or disturbances forecast as of yet that would bring a chance of more widespread thunderstorms during this period. Confidence is high that a warming trend will occur during this period...but not too warm since the southwest flow has a significant westerly component to shunt the hot air mass to the south of the region off to the east rather than pumping it northward into the forecast area. All in all a rather benign early summer weather regime is expected from Thursday through Sunday with a small chance of mountain thunderstorms especially in the Blues and Idaho Panhandle. /Fugazzi Sunday night through Tuesday night: Region remains in southwesterly flow throughout the period allowing for increased moisture to make it into the region. Along with the moisture, warm air will also accompany the flow bringing temps well above normal throughout the early part of the week. Weak waves of energy will pass through from SW to NE, but with limited forcing from any significant features mountain showers and isolated t-storms look to remain the extent of precip chances. The most notable feature comes through Tuesday, but even this currently is tough to get excited about as it is lacking overall dynamics. Even with models showing precipitable water values near an inch, without the trigger for showers the forecast currently looks pretty dry for most. For valley locations, the most likely changes noticed from the passing waves will be increased mid and high level clouds with maybe a stray shower. The most significant feature from the SW flow will be the warm temperatures. Monday currently looks to be the warmest with valley highs in the mid 80s to lower 90s. Even with a slight cool down on Tuesday, highs still remain 5 or so degrees above normal. /Fliehman && .AVIATION... 12z TAFS: Steady rain will remain over Ern WA and Nrn ID through 16z then gradual taper off from north to south. Light southwesterly flow will enhance mixing and allow IFR/MVFR cigs to raise and gradually scatter aft 20z. Surface heating will provide enough shallow instability to renew the threat for light showers with the highest PoPs over the higher terrain north of KGEG- KCOE. VFR conditions will return to all terminals by Wednesday afternoon/evening and persist through 12z. Fog expected to develop across the northeastern valleys and could come vcnty KSFF but confidence too low to include in TAF. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 65 49 76 52 79 54 / 60 10 0 0 0 10 Coeur d`Alene 62 47 74 49 78 51 / 60 20 0 0 0 10 Pullman 65 45 74 47 78 49 / 100 10 0 0 0 10 Lewiston 71 52 83 55 87 57 / 100 10 0 0 10 10 Colville 69 49 78 49 80 49 / 40 20 0 0 10 0 Sandpoint 60 45 73 45 77 48 / 50 30 10 0 10 0 Kellogg 59 46 72 48 76 52 / 100 30 10 0 10 20 Moses Lake 79 53 84 56 86 55 / 10 0 0 0 0 10 Wenatchee 81 57 84 60 86 57 / 10 0 0 0 0 10 Omak 81 52 86 54 84 52 / 10 0 0 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
240 AM PDT WED JUN 18 2014 .SYNOPSIS...AN UPPER LEVEL CLOSED LOW WAS CENTERED OVER IDAHO EARLY THIS MORNING AND WILL CONTINUE MOVING EAST TODAY. A BRIEF UPPER LEVEL RIDGE WILL MOVE INTO THE PACIFIC NORTHWEST TODAY FOR DRIER AND WARMER WEATHER THAT WILL GENERALLY LAST INTO THURSDAY. THE NEXT FRONT WILL APPROACH THE SOUTH WASHINGTON AND NORTH OREGON COAST LATER THURSDAY THEN INLAND THURSDAY NIGHT AND INTO FRIDAY FOR INCREASING ONSHORE FLOW AND ANOTHER CHANCE OF LIGHT SHOWERS. THEN EXPECT A TYPICAL ONSHORE FLOW PATTERN NEXT WEEKEND INTO EARLY NEXT WEEK WITH A LARGE SCALE TROUGH OVER THE NORTHEAST PACIFIC THAT WILL PRODUCE SOUTHWEST FLOW ALOFT OVER THE PACIFIC NORTHWEST... MAINTAINING ONSHORE FLOW FOR RATHER PERSISTENT LOW CLOUDS ALONG THE COAST AND AN OVERNIGHT AND MORNING MARINE STRATUS REGIME INLAND. && .SHORT TERM...THE UPPER LOW THAT BROUGHT UNSETTLED AND COOL WEATHER TO SOUTHWEST WASHINGTON AND NORTHWEST OREGON THE LAST FEW DAYS WAS CENTERED IN IDAHO EARLY THIS MORNING AND WILL CONTINUE TO MOVE EAST AND AWAY FROM OUR FORECAST AREA TODAY. THE RESIDUAL ONSHORE FLOW HAS A COMPLICATED LOW CLOUD PATTERN OVER THE FORECAST AREA THIS MORNING...WITH STRATOCUMULUS BANKED UP AGAINST THE CASCADES AND FOOTHILLS AND INTO THE EASTERN PART OF THE VALLEYS. THERE IS ANOTHER AREA OF LOW CLOUDS ALONG THE NORTH COAST WITH A BIT LOWER CIGS. IT NOW APPEARS THE GAP BETWEEN THESE TWO BANKS OF CLOUDS WILL FILL IN QUITE A BIT THIS MORNING...EXCEPT PERHAPS ALONG THE CENTRAL COAST WHERE ONLY PATCHY LOW CLOUDS OR FOG ARE EXPECTED. THE MODELS STILL PAINT A TOUCH OF QPF THIS MORNING MAINLY ALONG THE CASCADES AND THE NORTH COAST...AND CANNOT RULE IT OUT BUT ANYTHING THAT FALLS SHOULD BE RATHER MINOR. WITH A SHORT WAVE UPPER RIDGE MOVING IN TODAY THE CLOUDS SHOULD CLEAR AS WE GET A WAYS INTO THE AFTERNOON...EXCEPT PERHAPS ON THE NORTH COAST. TEMPS WILL HAVE A CHANCE TO REACH 70 TODAY INLAND. THE MODELS ARE FORECASTING A LONG WAVE TROUGH TO SET UP OFF THE COAST OVER THE NORTHEAST PACIFIC TONIGHT AND THURSDAY THAT WILL PERSIST INTO NEXT WEEK. THIS WILL PRODUCE A SOUTHWEST FLOW ALOFT THAT IS USUALLY PRETTY GOOD AT MAINTAINING A RATHER PERSISTENT MARINE LAYER ALONG THE COAST THAT SPREADS INLAND IN THE NIGHT AND MORNING HOURS. THE FIRST LITTLE DISTURBANCE ROTATING AROUND AND OUT OF THE LONG WAVE TROUGH MAY BRUSH THE SOUTH WASHINGTON COAST TO NEAR ASTORIA WILL A LITTLE DRIZZLE LATE TONIGHT AND THURSDAY. INLAND AREAS WILL SEE SOME MORNING LOW CLOUDS THURSDAY OTHERWISE MORE SUNSHINE AND WARMER TEMPS INTO THE MID 70S. THE NEXT SYSTEM IS A WEAKENING FRONT THAT CONTINUES TO BE FORECAST TO MOVE ONSHORE THURSDAY NIGHT AND ACROSS THE FORECAST AREA EARLY FRIDAY. THIS SHOULD BRING MORE PERSISTENT CLOUDY CONDITIONS TO THE AREA...WITH A FEW LIGHTER SHOWERS AS WELL. TOLLESON .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... FRIDAY NIGHT THROUGH MONDAY...EXPECT LITTLE VARIATION IN THE WEATHER OVER THE EXTENDED PORTION OF THE FORECAST. THE UPCOMING WEEKEND AND FIRST HALF OF NEXT WEEK WILL DOMINATED BY A LONG WAVE UPPER LEVEL TROUGH OVER THE NORTHEAST PACIFIC. PERIODIC SHORT WAVES ROTATING AROUND THE LOW WILL BRING REINFORCING SHOTS OF MARINE AIR...BUT AT THIS POINT LITTLE OR NO PRECIPITATION IS EXPECTED. EXPECT A TYPICAL ONSHORE FLOW PATTERN OF OVERNIGHT AND MORNING MARINE STRATUS PUSHES FOLLOWED BY PARTIAL AFTERNOON CLEARING. TEMPS WILL LIKELY REMAIN NEAR SEASONAL NORMALS. PYLE && .AVIATION...TWO LAYERS OF CLOUDS AFFECTING THE AREA THIS MORNING. ONE BANKING UP AGAINST THE CASCADES AND BACK FILLING OVER PARTS OF THE INTERIOR LOWLANDS IS AROUND 4000 FT. ANOTHER LAYER IS PUSHING INLAND FROM THE COASTAL WATERS WITH CIGS AROUND 3000 FT. MAY SEE SOME OF THE MVFR CIGS AFFECT LOWER COLUMBIA TO THE KPDX ARE FOR A FEW HOURS...14Z TO 17Z WED. GENERAL TREND IS FOR CLOUDS TO DISSIPATE AFTER MIDDAY. MUCH OF THE SOUTH COAST AND SOUTH INTERIOR TO NEAR KEUG REMAIN CLR-SCT AND WILL LIKELY REMAIN SO TODAY. ONSHORE FLOW CONTINUES TONIGHT AND LOOKS LIKE THE MARINE STRATUS WILL FILL IN ON THE COAST WITH CIGS IN THE 1500-2500 FT RANGE AND WILL HAVE LIMITED INLAND INTRUSION. KPDX AND APPROACHES...VFR CONDITIONS PREVAILING TODAY AND TONIGHT. HOWEVER...THERE IS CERTAINLY A DECENT CHANCE AN MVFR DECK AROUND 2500 FT BETWEEN 13Z AND 17Z WED. && .MARINE...VERY FEW CHANGES THROUGH THE WEEKEND AS RELATIVELY BENIGN WINDS AND SEAS DOMINATE. HIGH PRES DOMINATES THE NE PACIFIC THROUGH THERE ARE WEAK FRONTS WEAKENING THE HIGH PRES OVER THE WATERS TODAY. A STRONGER FRONT PUSHES INTO THE WATERS LATER THU AFTERNOON AND EVENING. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND 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 National Weather Service Spokane WA 217 AM PDT WED JUN 18 2014 .SYNOPSIS... Light rain will continue over the Idaho Panhandle and extreme eastern Washington through this morning. A drying trend will begin this afternoon with only a few lingering showers over the Panhandle tonight. Warmer...drier and more summer-like conditions will envelop the region for the rest of the week with a small chance of afternoon thunderstorms mainly over the mountains through the weekend. && .DISCUSSION... Wednesday: A deep low pressure system currently spinning over southwestern Montana will begin to track east this afternoon. The steady stream of moisture and vort max`s wrapping around its backside will finally get pulled east of the ID/MT border and rain will come to an end today following almost 24-30 hours of straight rainfall. This will be a rather slow drying trend with steady rain likely to linger through much of the morning before giving way to scattered light showers during the afternoon hours. 2AM radar and satellite confirms two last vorticity maximums will pass through the Inland NW before the storm system drifts east. One is driving moderate rains across SE WA while a second is making its way into Nrn ID from NW Montana. Timing utilizing the HRRR and satellite extrapolation suggest steady rain will end in the north (NE WA/Nrn ID) around 8AM and south (Palouse, Blues, L-C Valley, Camas Prairie) roughly 11AM. Confidence is not as high for the Central Panhandle Mtns of ID, especially along the immediate MT border which looks be clipped by one last wave of moisture during the afternoon hours. As the steady precipitation ends, sunbreaks will help destabilize the atmosphere promoting a renewed threat for showers. 500mb warming suggest any convection will be shallow but given the saturated boundary layer now in place, it even shallow convection could yield another tenth of an inch. May even get a stray thunderstorm across the northeastern mountains. Weak high pressure will begin building into the region Wednesday night and continue on Thursday. There is a good possibility that fog forms in the northeastern valleys of WA and Nrn ID after these soaking rains but coverage is still somewhat uncertain due to a light push of w/sw winds behind today`s storm system and possibility for lingering cloud cover. Spring will return to the Inland NW on Thursday under the shortwave ridging. There should be a good deal of sunshine in the morning giving way to fair afternoon cumulus and temperatures will return to seasonal normals. /sb Thursday night through Sunday...Model agreement is decent and consistent in placing the forecast area in a sustained southwest flow regime under the southeast flank of a stationary Gulf of Alaska closed low. This pattern typically argues for generally dry conditions in the basin with a small chance of afternoon and evening thunderstorms over the mountains north and east of the basin. There do not appear to be any significant waves or disturbances forecast as of yet that would bring a chance of more widespread thunderstorms during this period. Confidence is high that a warming trend will occur during this period...but not too warm since the southwest flow has a significant westerly component to shunt the hot air mass to the south of the region off to the east rather than pumping it northward into the forecast area. All in all a rather benign early summer weather regime is expected from Thursday through Sunday with a small chance of mountain thunderstorms especially in the Blues and Idaho Panhandle. /Fugazzi Sunday night through Tuesday night: Region remains in southwesterly flow throughout the period allowing for increased moisture to make it into the region. Along with the moisture, warm air will also accompany the flow bringing temps well above normal throughout the early part of the week. Weak waves of energy will pass through from SW to NE, but with limited forcing from any significant features mountain showers and isolated t-storms look to remain the extent of precip chances. The most notable feature comes through Tuesday, but even this currently is tough to get excited about as it is lacking overall dynamics. Even with models showing precipitable water values near an inch, without the trigger for showers the forecast currently looks pretty dry for most. For valley locations, the most likely changes noticed from the passing waves will be increased mid and high level clouds with maybe a stray shower. The most significant feature from the SW flow will be the warm temperatures. Monday currently looks to be the warmest with valley highs in the mid 80s to lower 90s. Even with a slight cool down on Tuesday, highs still remain 5 or so degrees above normal. /Fliehman && .AVIATION... 06z TAFS: Wrap moisture moisture will continue to move into the eastern third of WA and N Idaho on the back side of a low pressure system. This will keep a continuation of light to moderate rain at KGEG/KSFF/KCOE/KPUW/KLWS...decreasing between 12-18z Wednesday as the low begins to pull away from the region. A very moist boundary layer along with light low level upslope flow into the higher terrain of the Palouse, Spokane/Coeur D`Alene area should result in lowering CIGS overnight with IFR conditions expected. However areas of heavier rainfall will result in brief improvement to VFR CIGS. Then as precip decreases Wednesday morning and drier air invades from the west...CIGS will respond with VFR conditions expected Wed afternoon. KMWH and KEAT will be much less affected with VFR conditions likely to persist through 00z Thursday. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 65 49 76 52 79 54 / 60 10 0 0 0 10 Coeur d`Alene 62 47 74 49 78 51 / 60 20 0 0 0 10 Pullman 65 45 74 47 78 49 / 100 10 0 0 0 10 Lewiston 71 52 83 55 87 57 / 100 10 0 0 10 10 Colville 69 49 78 49 80 49 / 40 20 0 0 10 0 Sandpoint 60 45 73 45 77 48 / 50 30 10 0 10 0 Kellogg 59 46 72 48 76 52 / 100 30 10 0 10 20 Moses Lake 79 53 84 56 86 55 / 10 0 0 0 0 10 Wenatchee 81 57 84 60 86 57 / 10 0 0 0 0 10 Omak 81 52 86 54 84 52 / 10 0 0 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1039 PM CDT THU JUN 19 2014 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 232 PM CDT THU JUN 19 2014 ANOTHER ROUND OF WIDESPREAD RAIN EXPECTED TONIGHT INTO TOMORROW. THE UPR FLOW ACRS THE CONUS WL DEAMPLIFY SOME DURING THE FIRST HALF OF THE FCST PERIOD...LEAVING A SEASONABLY STG BAND OF ZONAL WESTERLIES ACRS ABOUT THE NRN 1/3 OF THE CONUS FOR THE WEEKEND. MEANWHILE...THE FLOW ACRS CANADA WL REMAIN FAIRLY BLOCKY. THE LARGE SCALE EVOLUTION NEXT WEEK AND BEYOND IS SOMEWHAT MUDDLED. AN UPR RIDGE SEEMS LIKELY TO CONSOLIDATE OVER THE CANADIAN ROCKIES...BUT THERE ARE QUESTIONS CONCERNING TO WHAT EXTENT THE DOWNSTREAM TROFFING WL EXTEND SWD INTO THE GREAT LAKES RGN. THERE WL BE NUMEROUS OPPORTUNITIES FOR PCPN DURING THE PERIOD. THE MOST SIGNIFICANT IS LIKELY TO OCCUR TNGT/FRI...WITH ANOTHER POSSIBLE EARLY NEXT WK. EVEN BETWEEN THOSE TIMES...IT WL BE TOUGH TO RULE OUT RAIN COMPLETELY...THOUGH SHOWERS SHOULD BE MORE SCT AND AMNTS LIGHTER BTWN THE MAIN EVENTS. PCPN AMNTS ARE LIKELY TO END UP WELL ABV NORMAL FOR THE PERIOD. TEMPS WL PROBABLY END UP CLOSE TO SEASONAL NORMALS...WITH THE DAYS WITH THE SIG PCPN RUNNING A LITTLE COOLER. && .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 232 PM CDT THU JUN 19 2014 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW UPPER LEVEL LOW PRESSURE SPINNING OVER NORTHERN MONTANA WITH SEVERAL SHORTWAVES MOVING AROUND THE PERIPHERY OVER THE NORTHERN PLAINS. FARTHER DOWN LOW...AN 850MB WARM FRONT IS SLOWLY LIFTING NE INTO NW TO SOUTH-CENTRAL WISCONSIN WHILE THE COLD FRONT EXTENDS SOUTHWARD OVER WESTERN MINNESOTA AND NORTHWEST IOWA. VARIOUS BANDS OF CONVECTION CONTINUE TO DEVELOP THIS AFTERNOON UPSTREAM. ONE BAND IS INTENSIFYING OVER EASTERN IOWA AND BEGINNING TO MOVE INTO FAR SW WISCONSIN. ANOTHER BAND IS ALSO INTENSIFYING OVER WESTERN IOWA. THESE AREAS OF CONVECTION ARE DEVELOPING WITHIN A TROPICAL MOISTURE FEED WHERE PWATS ARE OVER 1.75 INCHES. AS THIS CONVECTION MOVES NORTHEAST TONIGHT...TIMING AND IMPACTS FROM THESE SHOWERS AND STORMS ARE THE MAIN FORECAST CONCERNS. TONIGHT...A POTENT SHORTWAVE TROUGH WILL SWING NORTHEAST ACROSS THE NORTHERN PLAINS. AHEAD OF THIS TROUGH...AN 850MB WARM FRONT WILL LIFT NORTHEAST ACROSS NORTHERN WISCONSIN THIS EVENING AND USHER A TROPICAL AIRMASS INTO THE REGION. UPPER DIVERGENCE INCREASES LATE THIS EVENING AND OVERNIGHT AND WILL BE ACCOMPANIED BY WEAK SHORTWAVE TROUGHING AND MID-LEVEL CONVERGENCE. ALTHOUGH ELEVATED CAPES WILL NOT BE PARTICULARLY HIGH (300-500 J/KG)...HIGH FREEZING LEVELS AND PWATS UPWARDS OF 1.75 INCHES WILL PROMOTE EFFICIENT RAIN PRODUCTION. BANDS OF SHOWERS AND THUNDERSTORMS SHOULD BE MOVING TO THE EAST AT A MODERATE PACE...BUT THE LOW FLASH FLOOD GUIDANCE FOR THE SOUTHERN TIER OF COUNTIES FROM WOOD TO MANITOWOC COUNTY HAS ME WORRIED ABOUT FLOODING POTENTIAL. AFTER COORD WITH SURROUNDING OFFICES...WILL PUT WOOD/PORTAGE/WAUSHARA INTO A FLASH FLOOD WATCH. LESS CONCERNED ABOUT SEVERE POTENTIAL DUE TO THE MARGINAL CAPES AND EFFECTIVE SHEARS. AS FAR AS TIMING GOES...STORMS SHOULD LIFT NE INTO CENTRAL WISCONSIN EARLY THIS EVENING AND INTO NE WISCONSIN LATE IN THE EVENING OR AFTER MIDNIGHT. LOWS IN THE MIDDLE 50S NORTH TO MIDDLE 60S SOUTH. FRIDAY...MODERATE TO HEAVY RAIN WILL CONTINUE TO MARCH NORTHEAST ACROSS THE FORECAST AREA THOUGH SHOULD BE EXITING CENTRAL WISCONSIN EARLY IN THE MORNING. NOT SURE HOW MUCH SUN THIS AREA WILL GET IN THE AFTERNOON AFTER ALL THE RAINFALL SO KEPT HIGH TEMPS CONSERVATIVE IN THE UPPER 70S. SHOWERS AND STORMS WILL LIKELY CONTINUE OVER NORTHEAST WISCONSIN THROUGH EARLY TO MIDDLE AFTERNOON WHERE HIGHS WILL STRUGGLE TO GET OUT OF THE 60S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 232 PM CDT THU JUN 19 2014 THOUGH THE MAIN RAIN AREA WL SHIFT OFF TO THE E BY EARLY TOMORROW EVENING...SCT LGT PCPN COULD LINGER FRI NGT. CARRIED LOW POPS TO ACCOUNT FOR THIS. ALSO ADDED A MENTION OF FG AFTER MIDNIGHT AS WINDS WL BE LIGHT AND THE BOUNDARY LAYER SHOULD BE MOIST AFTER ALL THE RAIN. NO STG FORCING FOR PCPN SAT/SAT NGT EITHER. EXPECT THE BEST CHC OF RAIN TO BE TO OUR S DURING THOSE TIMES...CLOSER TO THE CENTER OF THE VERY MOIST AIR MASS...BUT NEED TO CARRY CHC POPS AS FCST SOUNDINGS SHOWED LITTLE CONVECTIVE INHIBITION. ADDED A DIURNAL TREND TO THE POPS...BUT KEPT THEM PRETTY LOW OVERALL. SHRTWV RIDGING WL BE PASSING TO OUR E SUN. THAT WL ALLOW THE SFC BOUNDARY TO BEGIN SHIFTG NWD INTO THE AREA. WENT WITH AN INCREASE IN POPS FM EARLIER PERIODS...BUT NOTHING BEYOND CHC YET. BUILT MAX/MIN TEMP GRIDS FM A BLEND OF THE TOP PERFORMING GUIDANCE PRODUCTS...WITH SOME MANUAL ADJUSTMENT TO MAINTAIN CONSISTENCY BTWN WIND DIRECTION AND THE TEMPS LAKESIDE. GIVEN THE UNCERTAINTY CONCERNING THE EVOLUTION OF THE LARGE SCALE PATTERN NEXT WEEK...PRETTY MUCH STUCK WITH THE STANDARD BROAD- BASED INITIALIZATION GRIDS FOR THE EXTENDED PART OF THE FORECAST. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1038 PM CDT THU JUN 19 2014 CONDITIONS WILL BECOME MVFR AND THEN IFR FROM SOUTHWEST TO NORTHEAST TONIGHT AS A LARGE AREA OF SHOWERS AND THUNDERSTORMS APPROACH AHEAD OF A FRONTAL SYSTEM. THE PRECIPITATION WILL DIMINISH FRIDAY MORNING BUT LOW CLOUDS MAY LINGER THROUGH THE AFTERNOON AND EVENING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
905 PM CDT THU JUN 19 2014 .UPDATE... THE ATMOSPHERE IS VERY MOIST WITH PRECIPITABLE WATER VALUES PUSHING 2 INCHES ACROSS THE WRN CWA. THE PROBLEM IS WE/VE LOST ALL THE INSTABILITY...BOTH SURFACE AND MUCAPES. SHEAR IS OF NO CONSEQUENCE. SO...NOT SURPRISING TO SEE ALL THE THUNDERSTORMS DIMINISH TO MOSTLY A LARGE AREA OF LIGHT TO MODERATE RAIN WITH SOME EMBEDDED THUNDER. AND...THIS AREA IS SHRINKING. THE SURFACE TROF IS STILL OUT ACROSS SW MN AND WRN IOWA...BUT THIS IS ONE WEAK TROF. IT WON/T SWING THROUGH HERE UNTIL TOMORROW MORNING...SO THE THREAT FOR SHOWERS OR AN ISOLATED TRW WILL CONTINUE UNTIL IT MOVES THROUGH. THE FLASH FLOOD THREAT HAS ENDED SO WILL DROP THAT WITH THIS UPDATE. && .AVIATION/06Z TAFS/... VERY MOIST CONDITIONS WITH THE LARGE AREA OF DIMINISHING SHOWERS AND EMBEDDED THUNDER WILL COMBINE WITH LIGHT WINDS UNDER A WEAK PRESSURE PATTERN OVERNIGHT...RESULTING IN LOWER CIGS DEVELOPING BY THE NEXT TAF ISSUANCE AT 06Z. IT SHOULD BE A MIX OF IFR/MVFR CONDITIONS...WITH THE LOWER CONDITIONS EXPECTED ACROSS THE SOUTHEAST. FOG MAY BECOME AN ISSUE CLOSE TO THE LAKE AGAIN AS THE ONSHORE FLOW WILL CONTINUE...BUT IT WILL BE LIGHT. SO...PLENTY OF UNCERTAINTY UNDER THESE CONDITIONS. A SURFACE TROF WILL MOVE THROUGH THE AREA DURING THE MID TO LATE MORNING HOURS...EVENTUALLY BRINGING A DRIER AIRMASS AND IMPROVING CIGS/VSBYS. && .PREV DISCUSSION... /ISSUED 310 PM CDT THU JUN 19 2014/ SHORT TERM... TONIGHT AND FRIDAY - CONFIDENCE...MEDIUM MAIN FOCUS IS HANDLING CONVECTIVE TRENDS. MID LEVEL RIDGE AXIS SHIFTING EAST ALLOWING FOR SOUTHWEST UPPER FLOW TO TAKE SHAPE. THERE WILL BE SHORTWAVE ACTIVITY RIDING NORTHEAST IN THIS REGIME. STRONG 850 LOW LEVEL JET WILL BE LACKING. HOWEVER THERE WILL BE AN INCREASE IN MOISTURE FROM THE SOUTH INTO SC WI AS THE LOW PRESSURE TROUGH APPROACHES FROM THE DAKOTAS. BUFKIT SOUNDINGS SHOW SOME DECENT FACTORS FOR HEAVIER RAIN TOTALS. THE MOISTURE PROFILE SHOWS TALL SKINNY CAPE WITH ABUNDANT MOISTURE WITHIN THE COLUMN. AXIS OF PRECIPITABLE WATER VALUES UP TO 2 INCHES ACROSS ERN IA EXTENDING INTO SW WI. IN ADDITION MBE/CORFIDI VECTORS SHOWING LESS THAN 10 KNOTS FROM ERN IA INTO SC WI. SHORTWAVE HAS NEGATIVE TILT TO IT AND BISECTS CWA TOWARDS MIDNIGHT. LOW LEVEL CONVERGENCE WILL BE ENHANCED BY THE APPROACHING SURFACE/850 TROUGH AXES. HAVE THUS HOISTED A FLASH FLOOD WATCH FOR SC WI FOR TONIGHT. THE GFS FAVORS A SOUTHERN SOLUTION TO THE QPF MAX...THE NAM AND ECMWF DO HAVE A SECONDARY NORTHERN MAX WHICH MAKES SENSE GIVEN THE NORTHERN POSITION OF THE SHORTWAVE SUPPORT AND UPSTREAM ONGOING CONVECTION ACRS ERN IA NUDGING INTO SW WI. THE HRRR AND 4KM WRF SHOW SOME OF THIS CONVECTION SHIFTING SOUTH INTO IL THOUGH MOTION OF THIS AREA NOT REALLY SUPPORTIVE OF THAT. PREFER THE LOOK OF THE NAM/ECMWF ON TRENDS ATTM. LOW LEVEL TROUGH SHIFTS EAST ON FRIDAY SO HIGHEST POPS IN THE EAST AND DURING THE MORNING HOURS. FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM. THE MID/UPPER LEVEL FLOW BECOMES MORE ZONAL WITH A 75 KNOT UPPER LEVEL SPEED MAX MOVES ACROSS NORTHERN WISCONSIN WITH WEAK UPPER LEVEL DIVERGENCE MAINLY FRIDAY ACROSS SOUTHERN WISCONSIN AS WE GET INTO THE RIGHT ENTRANCE REGION. A BROAD 850/700 MB THERMAL RIDGE EXTENDS ACROSS THE REGION. 850 MB WARM AIR ADVECTION BRINGS 850 MB TEMPERATURES TO 19 CELSIUS BY SATURDAY. WEAK 700 MB UPWARD MOTION BEGINS AGAIN SATURDAY. NAM FORECAST SOUNDINGS SHOW A FAIRLY STRONG INVERSION FROM 950 TO 850 MB WITH DRY AIR. THE INVERSION WEAKENS AND IS GONE DURING THE AFTERNOON. NAM MIXED LAYER CAPES AGAIN RISE TO 2000 JOULES/KG AND SEVERE PARAMETERS RISE. WARM AND HUMID CONDITIONS ARE EXPECTED INLAND...WITH COOLER VALUES ONCE AGAIN NEAR THE LAKE WITH ONSHORE WINDS. THERE WILL BE A CHANCE OF THUNDERSTORMS...BUT NO STRONG LIFTING SOURCE IS SEEN FOR HIGH POPS. SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM. ONE SHORTWAVE EXITS SATURDAY NIGHT WITH A SHORTWAVE NORTH OF LAKE SUPERIOR. THE WEAKER 50 KNOT 250 MB AX MOVES ACROSS THE LAKE SUPERIOR AND NORTHERN WISCONSIN AREA. UPPER DIVERGENCE IS WEAK UNTIL SUNDAY AFTERNOON WHEN THE NAM HAS WHAT APPEARS IS A CONVECTIVELY INDUCED AREA OF RATHER STRONG UPPER DIVERGENCE AND AN INCREASE IN 700 MB UPWARD MOTION AHEAD OF A 30 KNOT 700 MB SPEED MAX THAT MOVES INTO THE UPPER MISSISSIPPI VALLEY ALONG WITH A WEAK COLD FRONT. NAM DEWPOINTS ARE IN THE MID 60S TO AROUND 70. NAM ALSO BRINGS ION SOME MODERATE TO HEAVY PRECIPITATION INTO MAINLY SOUTH CENTRAL WISCONSIN. SEVERE WEATHER PARAMETERS ARE MARGINAL WITH ZERO TO 1 KM MIXED LAYER CAPE RISING TO AROUND 1300 JOULES/KG. LONG TERM...MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM. A SHORTWAVE TROUGH MOVES ACROSS THE UPPER MISSISSIPPI VALLEY MONDAY AND ACROSS WISCONSIN MONDAY NIGHT. THE MAIN TROUGH DOES NOT MOVE INTO WISCONSIN UNTIL TUESDAY NIGHT. THE ECMWF IS FASTER WHILE THE GFS CLOSES A LOW OVER THE UPPER GREAT LAKES WEDNESDAY NIGHT. A SURFACE TROUGH MOVES ACROSS WISCONSIN MONDAY...WITH MODERATE RAINFALL INDICATED IN THE MODELS. STILL SOME LIGHT SHOWERS TUESDAY. HIGH PRESSURE BUILDS INTO WISCONSIN ON THE ECMWF BUT WITH THE SLOWER MOVING TROUGH THE GFS STILL HAS SOME PRECIPITATION. PREFER THE ECMWF ATTM. THURSDAY...FORECAST CONFIDENCE IS MEDIUM. BY THURSDAY THE ECMWF HAS A RIDGE ACROSS WISCONSIN...WHILE THE GFS STILL HAS THE UPPER LOW NEAR LAKE HURON. BOTH THE GFS AND ECMWF HAVE HIGH PRESSURE AFFECTING SOUTHERN WISCONSIN. AVIATION/00Z TAFS/... CIGS HAVE LIFTED TO MVFR LEVELS. MAIN FOCUS WILL BE ON INCOMING CONVECTION AS STALLED FRONT STARTS TO LIFT NORTH. WILL GRADUALLY SPREAD THE SLOW MOVING STORMS FROM IOWA ACROSS SRN WI THIS EVENING AND LINGER INTO AT LEAST FRIDAY MORNING AS LOW LEVEL TROUGH AXIS MOVES THROUGH. MAIN THREAT TONIGHT APPEARS TO BE HEAVY RAINS. SO EXPECT SOME LOCALIZED LOWER CIGS/VSBYS IN SOME OF THE HEAVIER STORMS. LOWER CIGS AND VSBYS APPEAR POSSIBLE DURING THE MRNG ON FRIDAY UNTIL SURFACE/850 TROUGHS MOVE TO THE EAST. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DAVIS TONIGHT/FRIDAY AND AVIATION/MARINE...COLLAR FRIDAY NIGHT THROUGH THURSDAY...HENTZ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
702 PM CDT THU JUN 19 2014 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 232 PM CDT THU JUN 19 2014 ANOTHER ROUND OF WIDESPREAD RAIN EXPECTED TONIGHT INTO TOMORROW. THE UPR FLOW ACRS THE CONUS WL DEAMPLIFY SOME DURING THE FIRST HALF OF THE FCST PERIOD...LEAVING A SEASONABLY STG BAND OF ZONAL WESTERLIES ACRS ABOUT THE NRN 1/3 OF THE CONUS FOR THE WEEKEND. MEANWHILE...THE FLOW ACRS CANADA WL REMAIN FAIRLY BLOCKY. THE LARGE SCALE EVOLUTION NEXT WEEK AND BEYOND IS SOMEWHAT MUDDLED. AN UPR RIDGE SEEMS LIKELY TO CONSOLIDATE OVER THE CANADIAN ROCKIES...BUT THERE ARE QUESTIONS CONCERNING TO WHAT EXTENT THE DOWNSTREAM TROFFING WL EXTEND SWD INTO THE GREAT LAKES RGN. THERE WL BE NUMEROUS OPPORTUNITIES FOR PCPN DURING THE PERIOD. THE MOST SIGNIFICANT IS LIKELY TO OCCUR TNGT/FRI...WITH ANOTHER POSSIBLE EARLY NEXT WK. EVEN BETWEEN THOSE TIMES...IT WL BE TOUGH TO RULE OUT RAIN COMPLETELY...THOUGH SHOWERS SHOULD BE MORE SCT AND AMNTS LIGHTER BTWN THE MAIN EVENTS. PCPN AMNTS ARE LIKELY TO END UP WELL ABV NORMAL FOR THE PERIOD. TEMPS WL PROBABLY END UP CLOSE TO SEASONAL NORMALS...WITH THE DAYS WITH THE SIG PCPN RUNNING A LITTLE COOLER. && .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 232 PM CDT THU JUN 19 2014 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW UPPER LEVEL LOW PRESSURE SPINNING OVER NORTHERN MONTANA WITH SEVERAL SHORTWAVES MOVING AROUND THE PERIPHERY OVER THE NORTHERN PLAINS. FARTHER DOWN LOW...AN 850MB WARM FRONT IS SLOWLY LIFTING NE INTO NW TO SOUTH-CENTRAL WISCONSIN WHILE THE COLD FRONT EXTENDS SOUTHWARD OVER WESTERN MINNESOTA AND NORTHWEST IOWA. VARIOUS BANDS OF CONVECTION CONTINUE TO DEVELOP THIS AFTERNOON UPSTREAM. ONE BAND IS INTENSIFYING OVER EASTERN IOWA AND BEGINNING TO MOVE INTO FAR SW WISCONSIN. ANOTHER BAND IS ALSO INTENSIFYING OVER WESTERN IOWA. THESE AREAS OF CONVECTION ARE DEVELOPING WITHIN A TROPICAL MOISTURE FEED WHERE PWATS ARE OVER 1.75 INCHES. AS THIS CONVECTION MOVES NORTHEAST TONIGHT...TIMING AND IMPACTS FROM THESE SHOWERS AND STORMS ARE THE MAIN FORECAST CONCERNS. TONIGHT...A POTENT SHORTWAVE TROUGH WILL SWING NORTHEAST ACROSS THE NORTHERN PLAINS. AHEAD OF THIS TROUGH...AN 850MB WARM FRONT WILL LIFT NORTHEAST ACROSS NORTHERN WISCONSIN THIS EVENING AND USHER A TROPICAL AIRMASS INTO THE REGION. UPPER DIVERGENCE INCREASES LATE THIS EVENING AND OVERNIGHT AND WILL BE ACCOMPANIED BY WEAK SHORTWAVE TROUGHING AND MID-LEVEL CONVERGENCE. ALTHOUGH ELEVATED CAPES WILL NOT BE PARTICULARLY HIGH (300-500 J/KG)...HIGH FREEZING LEVELS AND PWATS UPWARDS OF 1.75 INCHES WILL PROMOTE EFFICIENT RAIN PRODUCTION. BANDS OF SHOWERS AND THUNDERSTORMS SHOULD BE MOVING TO THE EAST AT A MODERATE PACE...BUT THE LOW FLASH FLOOD GUIDANCE FOR THE SOUTHERN TIER OF COUNTIES FROM WOOD TO MANITOWOC COUNTY HAS ME WORRIED ABOUT FLOODING POTENTIAL. AFTER COORD WITH SURROUNDING OFFICES...WILL PUT WOOD/PORTAGE/WAUSHARA INTO A FLASH FLOOD WATCH. LESS CONCERNED ABOUT SEVERE POTENTIAL DUE TO THE MARGINAL CAPES AND EFFECTIVE SHEARS. AS FAR AS TIMING GOES...STORMS SHOULD LIFT NE INTO CENTRAL WISCONSIN EARLY THIS EVENING AND INTO NE WISCONSIN LATE IN THE EVENING OR AFTER MIDNIGHT. LOWS IN THE MIDDLE 50S NORTH TO MIDDLE 60S SOUTH. FRIDAY...MODERATE TO HEAVY RAIN WILL CONTINUE TO MARCH NORTHEAST ACROSS THE FORECAST AREA THOUGH SHOULD BE EXITING CENTRAL WISCONSIN EARLY IN THE MORNING. NOT SURE HOW MUCH SUN THIS AREA WILL GET IN THE AFTERNOON AFTER ALL THE RAINFALL SO KEPT HIGH TEMPS CONSERVATIVE IN THE UPPER 70S. SHOWERS AND STORMS WILL LIKELY CONTINUE OVER NORTHEAST WISCONSIN THROUGH EARLY TO MIDDLE AFTERNOON WHERE HIGHS WILL STRUGGLE TO GET OUT OF THE 60S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 232 PM CDT THU JUN 19 2014 THOUGH THE MAIN RAIN AREA WL SHIFT OFF TO THE E BY EARLY TOMORROW EVENING...SCT LGT PCPN COULD LINGER FRI NGT. CARRIED LOW POPS TO ACCOUNT FOR THIS. ALSO ADDED A MENTION OF FG AFTER MIDNIGHT AS WINDS WL BE LIGHT AND THE BOUNDARY LAYER SHOULD BE MOIST AFTER ALL THE RAIN. NO STG FORCING FOR PCPN SAT/SAT NGT EITHER. EXPECT THE BEST CHC OF RAIN TO BE TO OUR S DURING THOSE TIMES...CLOSER TO THE CENTER OF THE VERY MOIST AIR MASS...BUT NEED TO CARRY CHC POPS AS FCST SOUNDINGS SHOWED LITTLE CONVECTIVE INHIBITION. ADDED A DIURNAL TREND TO THE POPS...BUT KEPT THEM PRETTY LOW OVERALL. SHRTWV RIDGING WL BE PASSING TO OUR E SUN. THAT WL ALLOW THE SFC BOUNDARY TO BEGIN SHIFTG NWD INTO THE AREA. WENT WITH AN INCREASE IN POPS FM EARLIER PERIODS...BUT NOTHING BEYOND CHC YET. BUILT MAX/MIN TEMP GRIDS FM A BLEND OF THE TOP PERFORMING GUIDANCE PRODUCTS...WITH SOME MANUAL ADJUSTMENT TO MAINTAIN CONSISTENCY BTWN WIND DIRECTION AND THE TEMPS LAKESIDE. GIVEN THE UNCERTAINTY CONCERNING THE EVOLUTION OF THE LARGE SCALE PATTERN NEXT WEEK...PRETTY MUCH STUCK WITH THE STANDARD BROAD- BASED INITIALIZATION GRIDS FOR THE EXTENDED PART OF THE FORECAST. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 702 PM CDT THU JUN 19 2014 VFR CONDITIONS WILL TURN TO MVFR AND THEN IFR FROM WEST TO EAST TONIGHT AS A LARGE AREA OF SHOWERS AND THUNDERSTORMS APPROACH AHEAD OF A WARM FRONT. THE PRECIPITATION WILL END BY MIDDAY FRIDAY WITH VFR CONDITIONS EXPECTED FRIDAY AFTERNOON. && .GRB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 AM CDT FRIDAY FOR WIZ035-036-045. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......RDM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SYNOPSIS... ISSUED AT 232 PM CDT THU JUN 19 2014 ANOTHER ROUND OF WIDESPREAD RAIN EXPECTED TONIGHT INTO TOMORROW. THE UPR FLOW ACRS THE CONUS WL DEAMPLIFY SOME DURING THE FIRST HALF OF THE FCST PERIOD...LEAVING A SEASONABLY STG BAND OF ZONAL WESTERLIES ACRS ABOUT THE NRN 1/3 OF THE CONUS FOR THE WEEKEND. MEANWHILE...THE FLOW ACRS CANADA WL REMAIN FAIRLY BLOCKY. THE LARGE SCALE EVOLUTION NEXT WEEK AND BEYOND IS SOMEWHAT MUDDLED. AN UPR RIDGE SEEMS LIKELY TO CONSOLIDATE OVER THE CANADIAN ROCKIES...BUT THERE ARE QUESTIONS CONCERNING TO WHAT EXTENT THE DOWNSTREAM TROFFING WL EXTEND SWD INTO THE GREAT LAKES RGN. THERE WL BE NUMEROUS OPPORTUNITIES FOR PCPN DURING THE PERIOD. THE MOST SIGNIFICANT IS LIKELY TO OCCUR TNGT/FRI...WITH ANOTHER POSSIBLE EARLY NEXT WK. EVEN BETWEEN THOSE TIMES...IT WL BE TOUGH TO RULE OUT RAIN COMPLETELY...THOUGH SHOWERS SHOULD BE MORE SCT AND AMNTS LIGHTER BTWN THE MAIN EVENTS. PCPN AMNTS ARE LIKELY TO END UP WELL ABV NORMAL FOR THE PERIOD. TEMPS WL PROBABLY END UP CLOSE TO SEASONAL NORMALS...WITH THE DAYS WITH THE SIG PCPN RUNNING A LITTLE COOLER. && .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 232 PM CDT THU JUN 19 2014 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW UPPER LEVEL LOW PRESSURE SPINNING OVER NORTHERN MONTANA WITH SEVERAL SHORTWAVES MOVING AROUND THE PERIPHERY OVER THE NORTHERN PLAINS. FARTHER DOWN LOW...AN 850MB WARM FRONT IS SLOWLY LIFTING NE INTO NW TO SOUTH-CENTRAL WISCONSIN WHILE THE COLD FRONT EXTENDS SOUTHWARD OVER WESTERN MINNESOTA AND NORTHWEST IOWA. VARIOUS BANDS OF CONVECTION CONTINUE TO DEVELOP THIS AFTERNOON UPSTREAM. ONE BAND IS INTENSIFYING OVER EASTERN IOWA AND BEGINNING TO MOVE INTO FAR SW WISCONSIN. ANOTHER BAND IS ALSO INTENSIFYING OVER WESTERN IOWA. THESE AREAS OF CONVECTION ARE DEVELOPING WITHIN A TROPICAL MOISTURE FEED WHERE PWATS ARE OVER 1.75 INCHES. AS THIS CONVECTION MOVES NORTHEAST TONIGHT...TIMING AND IMPACTS FROM THESE SHOWERS AND STORMS ARE THE MAIN FORECAST CONCERNS. TONIGHT...A POTENT SHORTWAVE TROUGH WILL SWING NORTHEAST ACROSS THE NORTHERN PLAINS. AHEAD OF THIS TROUGH...AN 850MB WARM FRONT WILL LIFT NORTHEAST ACROSS NORTHERN WISCONSIN THIS EVENING AND USHER A TROPICAL AIRMASS INTO THE REGION. UPPER DIVERGENCE INCREASES LATE THIS EVENING AND OVERNIGHT AND WILL BE ACCOMPANIED BY WEAK SHORTWAVE TROUGHING AND MID-LEVEL CONVERGENCE. ALTHOUGH ELEVATED CAPES WILL NOT BE PARTICULARLY HIGH (300-500 J/KG)...HIGH FREEZING LEVELS AND PWATS UPWARDS OF 1.75 INCHES WILL PROMOTE EFFICIENT RAIN PRODUCTION. BANDS OF SHOWERS AND THUNDERSTORMS SHOULD BE MOVING TO THE EAST AT A MODERATE PACE...BUT THE LOW FLASH FLOOD GUIDANCE FOR THE SOUTHERN TIER OF COUNTIES FROM WOOD TO MANITOWOC COUNTY HAS ME WORRIED ABOUT FLOODING POTENTIAL. AFTER COORD WITH SURROUNDING OFFICES...WILL PUT WOOD/PORTAGE/WAUSHARA INTO A FLASH FLOOD WATCH. LESS CONCERNED ABOUT SEVERE POTENTIAL DUE TO THE MARGINAL CAPES AND EFFECTIVE SHEARS. AS FAR AS TIMING GOES...STORMS SHOULD LIFT NE INTO CENTRAL WISCONSIN EARLY THIS EVENING AND INTO NE WISCONSIN LATE IN THE EVENING OR AFTER MIDNIGHT. LOWS IN THE MIDDLE 50S NORTH TO MIDDLE 60S SOUTH. FRIDAY...MODERATE TO HEAVY RAIN WILL CONTINUE TO MARCH NORTHEAST ACROSS THE FORECAST AREA THOUGH SHOULD BE EXITING CENTRAL WISCONSIN EARLY IN THE MORNING. NOT SURE HOW MUCH SUN THIS AREA WILL GET IN THE AFTERNOON AFTER ALL THE RAINFALL SO KEPT HIGH TEMPS CONSERVATIVE IN THE UPPER 70S. SHOWERS AND STORMS WILL LIKELY CONTINUE OVER NORTHEAST WISCONSIN THROUGH EARLY TO MIDDLE AFTERNOON WHERE HIGHS WILL STRUGGLE TO GET OUT OF THE 60S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 232 PM CDT THU JUN 19 2014 THOUGH THE MAIN RAIN AREA WL SHIFT OFF TO THE E BY EARLY TOMORROW EVENING...SCT LGT PCPN COULD LINGER FRI NGT. CARRIED LOW POPS TO ACCOUNT FOR THIS. ALSO ADDED A MENTION OF FG AFTER MIDNIGHT AS WINDS WL BE LIGHT AND THE BOUNDARY LAYER SHOULD BE MOIST AFTER ALL THE RAIN. NO STG FORCING FOR PCPN SAT/SAT NGT EITHER. EXPECT THE BEST CHC OF RAIN TO BE TO OUR S DURING THOSE TIMES...CLOSER TO THE CENTER OF THE VERY MOIST AIR MASS...BUT NEED TO CARRY CHC POPS AS FCST SOUNDINGS SHOWED LITTLE CONVECTIVE INHIBITION. ADDED A DIURNAL TREND TO THE POPS...BUT KEPT THEM PRETTY LOW OVERALL. SHRTWV RIDGING WL BE PASSING TO OUR E SUN. THAT WL ALLOW THE SFC BOUNDARY TO BEGIN SHIFTG NWD INTO THE AREA. WENT WITH AN INCREASE IN POPS FM EARLIER PERIODS...BUT NOTHING BEYOND CHC YET. BUILT MAX/MIN TEMP GRIDS FM A BLEND OF THE TOP PERFORMING GUIDANCE PRODUCTS...WITH SOME MANUAL ADJUSTMENT TO MAINTAIN CONSISTENCY BTWN WIND DIRECTION AND THE TEMPS LAKESIDE. GIVEN THE UNCERTAINTY CONCERNING THE EVOLUTION OF THE LARGE SCALE PATTERN NEXT WEEK...PRETTY MUCH STUCK WITH THE STANDARD BROAD- BASED INITIALIZATION GRIDS FOR THE EXTENDED PART OF THE FORECAST. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1206 PM CDT THU JUN 19 2014 A COOL FRONT WILL BE SLOWLY MOVING ACROSS THE AREA LATE TONIGHT INTO FRIDAY MORNING. AHEAD OF THE FRONT...ANTICIPATE MVFR CIGS LIFTING AND BECOMING SCATTERED OVER CENTRAL AND NORTH-CENTRAL WISCONSIN THIS AFTERNOON. THEN AS THE FRONT APPROACHES...CIGS WILL BE FALLING THIS EVENING. THE FRONT WILL BRING WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE ENTIRE REGION OVERNIGHT THROUGH FRIDAY MORNING. IFR VSBYS/CIGS CAN BE EXPECTED WITHIN THE THUNDERSTORMS. THE SLOW MOVING NATURE OF THE FRONT WILL LEAD TO ONLY GRADUAL IMPROVEMENT OF CIGS ONCE THE SHOWERS/STORMS PASS ON TO THE EAST ON FRIDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH FRIDAY MORNING FOR WIZ035-036-045. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
326 PM CDT WED JUN 18 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 325 PM CDT WED JUN 18 2014 MAIN FORECAST CONCERNS IS HEAVY RAIN POTENTIAL TONIGHT INTO THURSDAY MORNING. LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL LOW OVER THE NORTHERN ROCKY MOUNTAINS AND WEAK SHORTWAVE TROUGHS EMBEDDED IN THE SOUTHWESTERLY FLOW ALOFT OVER THE CENTRAL UNITED STATES. LATEST 19Z SURFACE ANALYSIS INDICATES WARM FRONT/RESIDUAL OUTFLOW BOUNDARY EXTENDING FROM SOUTHEAST SOUTH DAKOTA INTO SOUTHERN IOWA. TONIGHT INTO THURSDAY...THE LATEST 18.12Z GFS/NAM INDICATE MOISTURE TRANSPORT AND CONVERGENCE TO INCREASE AFTER 00Z THURSDAY WEST OF THE FORECAST AREA AND SHIFT THE NOSE OF THE MOISTURE TRANSPORT AND CONVERGENCE INTO FORECAST AREA BY 06Z THURSDAY. WITH SUBTLE WEAK SHORTWAVE TROUGHS EJECTING OUT OF THE HIGH PLAINS INTO THE UPPER MIDWEST...EXPECT ANOTHER MCS TO FORM AND MOVE CLOSE TO THE FORECAST AREA AFTER 03-06Z THURSDAY TIMEFRAME. HOWEVER...THE EXACT LOCATION OF WHERE THE MCS WILL FORM IS STILL UNCERTAIN AND WILL HAVE AN IMPACT WHERE HEAVY RAIN WILL FALL OVER FORECAST AREA. THE 18.12Z GFS/NAM AND 15Z RAP CONTINUE TO SHOW PRECIPITABLE WATER VALUES OF 1.5-2 INCHES ACROSS FORECAST AREA AND WARM CLOUD DEPTH EXTENDING UP TO 4KM PER BUFKIT SOUNDINGS ACROSS FORECAST AREA. ANY SHOWERS/THUNDERSTORM DEVELOPMENT OVER FORECAST AREA WILL BE EFFICIENT RAIN PRODUCERS AND PRODUCE LOCAL HEAVY RAIN. THE 18.12Z GFS/NAM SUGGEST WEAK SURFACE COLD FRONT TO MOVE ACROSS THE FORECAST AREA LATE THURSDAY AFTERNOON. THE MODELS INDICATE ENOUGH MOISTURE CONVERGENCE ALONG THE FRONT TO PRODUCE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS AND TRACK ACROSS FORECAST AREA THURSDAY AFTERNOON AND EVENING. NEXT CONCERN TONIGHT INTO THURSDAY IS SEVERE POTENTIAL...THE 18.12Z GFS/NAM INDICATE MAINLY ELEVATED INSTABILITY PER BUFKIT SOUNDINGS AND 0-3KM SHEAR IN THE 25 TO 30 KNOTS RANGE ACROSS FORECAST AREA. THE MODELS SUGGEST ALL SHEAR IN THE 0-3KM LAYER...AS THE 0-6KM SHEAR SHOWS ABOUT 30 TO 35 KNOTS. AT THIS TIME...LOOKING AT DAMAGING WINDS...LARGE HAIL AND FLASH FLOODING FROM HEAVY RAINFALL THE MAIN THREATS MAINLY SOUTH OF INTERSTATE 94. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 325 PM CDT WED JUN 18 2014 WEST TO EAST ZONAL FLOW DEVELOPS ACROSS THE NORTHERN TIER STATES FRIDAY AND SATURDAY. THE 18.12Z GFS/NAM SHOW WEAK IMPULSES EMBEDDED IN THE FLOW WITH ENOUGH MOISTURE CONVERGENCE AND LIFT IN ASSOCIATION WITH EACH IMPULSE...SHOULD ALLOW THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS ACROSS FORECAST AREA. SATURDAY NIGHT THROUGH WEDNESDAY...MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THROUGH THE PERIOD. THE 18.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN DIGGING UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION EARLY NEXT WEEK. SIGNIFICANT DIFFERENCES ARE INDICATED BETWEEN THE MODELS WITH TIMING OF SHORTWAVE TROUGHS EMBEDDED IN THE WEST TO EAST ZONAL FLOW SATURDAY NIGHT INTO SUNDAY AND THE STRENGTH OF THE UPPER LEVEL TROUGH DIGGING OVER THE GREAT LAKES REGION EARLY NEXT WEEK. THIS WILL HAVE IMPACTS ON TIMING OF MOISTURE RETURN/PRECIPITATION CHANCES INTO THE FORECAST AREA SUNDAY INTO MONDAY. NEXT CONCERN ARE TEMPERATURES FOR MIDDLE OF NEXT WEEK. WITH THE 18.12Z GFS/ECMWF DIFFERING SLIGHTLY ON STRENGTH OF UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION...THE 18.12Z GFS/ECMWF DIFFER ON HOW COOL AIRMASS WILL BE OVER THE FORECAST AREA...WITH THE 18.12Z ECMWF ADVECTING IN SLIGHTLY COOLER TEMPERATURES THAN THE 18.12Z GFS. THE 18.12Z ECMWF SHOWING 850MB TEMPERATURES PLUS 10 TO PLUS 12 DEGREES CELSIUS OVER FORECAST AREA...COMPARED TO PLUS 12 TO PLUS 14 DEGREES CELSIUS 850MB TEMPERATURES BY THE 18.12Z GFS. TEMPERATURES OVER FORECAST AREA BY MIDDLE OF NEXT WEEK LOOK TO BE UNSEASONABLY COOL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1240 PM CDT WED JUN 18 2014 GENERALLY VFR CONDITIONS TO PREVAIL OUTSIDE OF CONVECTIVE SYSTEMS...WHICH REMAIN SOMEWHAT TROUBLE TO NAIL DOWN. IN WAKE OF OVERNIGHT SYSTEM...EXPECT QUIET PERIOD THROUGH MUCH OF TODAY BUT WITH WARM FRONT BOUNDARY STILL IN AREA AND LOW LEVEL JET SETTING UP AGAIN TONIGHT...COULD SEE REPEAT PERFORMANCE WITH MAINLY LATE NIGHT STORMS AGAIN. BETTER FORCING AND MOISTURE TRANSPORT SEEMS FURTHER WEST AND SOUTH TONIGHT SO UNSURE OF INTENSITY BUT LEANED ON LATE NIGHT CONVECTION AND TRIED TO NARROW DOWN A SMALL TIME WINDOW FOR BRUNT OF STORMS/LOWEST AVIATION CATEGORIES. CONVECTION SHOULD CLEAR OUT THURSDAY MORNING SO RETURN TO VFR. && .HYDROLOGY... ISSUED AT 325 PM CDT WED JUN 18 2014 THE FORECAST AREA REMAINS IN A VERY MOIST AND UNSTABLE AIRMASS THROUGH THURSDAY EVENING WITH PRECIPITABLE WATER VALUES IN THE 1.5 TO 2 INCH RANGE AND WARM CLOUD DEPTHS UP TO 4 KM. THE COMBINATION OF ANOTHER ROUND OF CONVECTION TO IMPACT THE FORECAST AREA TONIGHT AND RECENT HEAVY RAINFALL THE LAST COUPLE OF DAYS...WILL CONTINUE WITH THE FLASH FLOOD WATCH FOR SOUTHEAST MINNESOTA...NORTHEAST IOWA...SOUTHWEST AND CENTRAL WISCONSIN THROUGH THURSDAY MORNING. ALSO...DUE TO THE RECENT HEAVY RAINFALL...THE CEDAR...TREMPEALEAU AND BLACK RIVERS HAVE RISEN OR ARE FORECASTED TO RISE ABOVE FLOOD STAGE AND FLOOD WARNINGS ARE IN EFFECT PORTIONS OF THESE RIVERS. SEE THE LATEST FLOOD STATEMENTS FOR EXACT FORECAST DETAILS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR WIZ032>034- 041>044-053>055-061. MN...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR MNZ079-086>088- 094>096. IA...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR IAZ008>011-018- 019-029-030. && $$ SHORT TERM...DTJ LONG TERM...DTJ AVIATION...TJS HYDROLOGY...DTJ
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 234 PM CDT WED JUN 18 2014 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE REMNANTS OF AN MCV MOVING EAST ACROSS NORTHEAST WISCONSIN EARLY THIS AFTERNOON. MOST OF THE RAIN HAS EXITED THE REGION EXCEPT FOR A FEW SPOTTY SHOWERS OVER EAST-CENTRAL WISCONSIN. CONVECTIVE OUTFLOW BOUNDARY HAS SHIFTED SOUTH INTO CENTRAL ILLINOIS AND CENTRAL IOWA...BUT A BAND OF CLOUDS FROM SOUTHERN WISCONSIN TO CENTRAL MINNESOTA MARKS WHERE THE 850MB FRONT IS LOCATED. AREAS IN PROXIMITY OF THESE BOUNDARIES ARE MOSTLY DRY DUE TO STRONG CAPPING OVERHEAD. FORECAST CONCERNS REVOLVE AROUND THE POSSIBILITY OF RENEWED STORM DEVELOPMENT TONIGHT AND TOMORROW. TONIGHT...MCV OVER EASTERN WISCONSIN WILL BE EXITING TO THE EAST EARLY IN THE EVENING. REMNANT 850MB BOUNDARY WILL HANG BACK HOWEVER...FROM EAST-CENTRAL OR SOUTHEAST WISCONSIN TO CENTRAL MINNESOTA BUT WILL PIVOT A BIT AS THE WESTERN END BENDS NORTHWARD. WILL HAVE WEAK LIFT ALONG THE FRONT THROUGH THE EVENING IN THE FORM OF ISENTROPIC ASCENT AND MID-LEVEL FGEN. MODELS ARE QUITE DRY THIS EVENING OVER CENTRAL WISCONSIN WHICH IS THE PART OF THE FORECAST AREA THAT WILL BE CLOSEST TO THE BOUNDARY. BUT THE CLOSE PROXIMITY OF THE FRONT TO CENTRAL WISCONSIN WILL KEEP A LOW CHANCE OF SHOWERS AND STORMS IN THE FORECAST FOR THE EVENING. AS HEIGHT FALLS ACROSS THE NORTHERN PLAINS CAUSE THE WESTERN PART OF THE FRONT TO LIFT NORTHWARD...CHANCES OF SHOWERS AND STORMS WILL SPREAD NORTHEAST A BIT OVERNIGHT. BUT UNLIKE THE LAST COUPLE NIGHTS...WILL NOT HAVE ANY UPPER LEVEL SUPPORT AND CANNOT FIND HARDLY ANY INSTABILITY. SO AM NOT THINKING A REPEAT OF LAST NIGHTS WIDESPREAD HEAVY RAIN WILL OCCUR...BUT MORE IN THE WAY OF ISOLD TO SCT SHOWERS AND STORMS. NORTHEAST WISCONSIN MAY REMAIN DRY THROUGH THE NIGHT WHERE NORTHEAST WINDS WILL BE FUNNELING STABLE AIR INTO THIS PART OF THE STATE. LOWS RANGING FROM THE MIDDLE 50S NORTHEAST TO THE MIDDLE 60S SOUTHWEST. THURSDAY...A LARGE CLOSED UPPER LOW WILL SHIFT EAST ACROSS THE NORTHWEST GREAT PLAINS...WHICH WILL HELP PUSH THE 850MB FRONT INTO NORTHEAST WISCONSIN. WILL CONTINUE TO HAVE WEAK FORCING ALONG THE FRONT ALONG WITH PWATS UPWARDS OF 1.75 INCHES. WITH SUFFICIENT DAYTIME HEATING...A 79/65 PARCEL WILL YIELD NEARLY 1000 J/KG OF ML CAPE NEAR WISCONSIN RAPIDS. 0-6KM BULK SHEARS ARE ONLY AROUND 25 KTS...AND WITH QUESTION MARKS ABOUT THE AMOUNT OF HEATING AND DEGREE OF FORCING...THINK A SEVERE THREAT IS RATHER MARGINAL. SPC KEEPS THE SLIGHT RISK OF SEVERE WEATHER OVER FAR SW WISCONSIN TOMORROW...AND THIS LOOKS GOOD. BEING NEAR THE MID-LEVEL RIDGE AXIS...ANY STORMS WILL BE SLOW MOVING AND COULD DROP QUICK HALF INCH TO INCH OF RAINFALL. BUT AM ANTICIPATING COVERAGE TO BE ONLY SCT IN NATURE DUE TO THE WEAK FORCING. WILL HAVE THE HIGHEST CHANCES OF PRECIP OVER CENTRAL WISCONSIN DURING THE AFTERNOON. HIGH TEMPS RANGING FROM THE MIDDLE 70S TO LOW 80S. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 234 PM CDT WED JUN 18 2014 OVERALL UPPER-LEVEL FLOW OVER THE WESTERN GREAT LAKES WILL BECOME BRIEFLY MORE ZONAL LATE IN THE WORK WEEK AS UPPER-LOW NEAR LAKE WINNEPEG HEADS EAST ACROSS SOUTHERN CANADA AND UNDERCUTS RIDGE. UNFORTUNATELY...WEAK IMPULSES EMBEDDED WITHIN THE ZONAL FLOW WILL CONTINUE TO PROVIDE OPPORTUNITIES FOR BOUTS OF PRECIPITATION INTO THE WEEKEND. UNLIKELY MODEL GUIDANCE WILL HAVE A VERY GOOD HANDLE ON THESE WEAK IMPULSES THUS FORECAST CONFIDENCE HEADING INTO THE WEEKEND IS LOW. EVENTUALLY PATTERN AMPLIFIES AGAIN OVER THE NORTHERN CONUS AS UPPER-LEVEL RIDGE AXIS TRIES TO BECOME RE- ESTABLISHED FURTHER WEST OVER CENTRAL CANADA WITH DOWNSTREAM TROUGH DIGGING SOUTHWARD OVER THE WESTERN GREAT LAKES DURING THE FIRST HALF OF NEXT WEEK. LATEST GUIDANCE ALSO SUGGESTS SOME POTENTIAL FOR WEAK DISTURBANCES TO UNDERCUT CANADIAN RIDGE AS THEY MOVE ACROSS THE NORTHERN PLAINS TOWARD THE WESTERN GREAT LAKES. BOTTOM LINE IS THAT UNSETTLED WEATTHER PATTERN WILL LIKELY PERSIST INTO THE MIDDLE OF NEXT WEEK WITH ABOVE NORMAL PRECIPTATION. THURSDAY NIGHT INTO FRIDAY APPEARS TO BE THE MOST ACTIVE PERIOD IN THE EXTENDED PORTION OF THE FORECAST AS FAIRLY ROBUST SHORTWAVE TROUGH WEST OF LAKE WINNEPEG EJECTS DISTURBANCES EASTWARD TOWARD THE AREA. THESE IMPULSES WILL PROVIDE MORE ORGANIZED LARGE- SCALE ASCENT THAT WILL ACT IN CONCERT WITH A FRONTAL BOUNDARY THAT WILL REMAIN JUST SOUTHWEST OF THE FORECAST AREA. RATHER POTENT DISTURBANCE IS FORECAST TO SWING NORTHEAST TOWARD THE UPPER MISSISSIPPI VALLEY THURSDAY EVENING. STILL MUCH UNCERTAINTY AS TO HOW CONVECTION WILL EVOLVE THURSDAY NIGHT ALONG THE MISSISSIPPI RIVER VALLEY. CONSENSUS OF MODEL GUIDANCE SEEMS TO SUGGEST TWO AREAS OF FOCUS FOR CONVECTION EARLY THURSDAY EVENING...ONE ALONG THE WARM FRONT AND GREATER INSTABILITY OVER NORTHEAST IOWA AND SOUTHWEST WISCONSIN...AND THE OTHER CLOSER TO THE STRONGER UPPER- LEVEL DYNAMICS OVER CENTRAL MINNESOTA. ALL MODELS SUGGEST CONVECTIVE ACTIVITY WILL LIKELY CONSOLIDATE OVER THE FORECAST AREA OVERNIGHT THURSDAY THEN PUSH EAST ACROSS THE AREA FRIDAY MORNING. STILL COPIOUS MOISTURE IN PLACE OVER THE FORECAST AREA...THUS ANOTHER BOUT OF FAIRLY SUBSTANTIAL RAINFALL SEEMS TO BE A GOOD BET. HOWEVER...DEEP LAYER SHEAR DOES NOT APPEAR TO BE VERY SUPPORTIVE OF WIDESPREAD SEVERE CONVECTION OVER THE FORECAST AREA THURSDAY NIGHT WITH SHEAR MORE FAVORABLE UPSTREAM OVER IOWA AND SOUTHERN MINNESOTA AND PERHAPS INTO SOUTHWEST WISCONSIN. ALTHOUGH THERE COULD BE A BREAK IN THE PRECIPITATION FRIDAY AFTERNOON...BULK OF MODEL GUIDANCE SUGGESTS ANOTHER IMPULSE TO EJECT EASTWARD ACROSS THE WESTERN GREAT LAKES SOMETIME FRIDAY NIGHT INTO SATURDAY. HOWEVER WAY TOO MUCH DISCREPANCY IN THE GUIDANCE TO TRY AND NAIL DOWN LOCATION AND TIMING...SO WILL BE FORCED TO MAINTAIN BROAD BRUSH CHANCE POPS OVER THE ENTIRE AREA FRIDAY NIGHT RIGHT ON THROUGH THE WEEKEND. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1210 PM CDT WED JUN 18 2014 SHOWERS AND THUNDERSTORMS ARE DEPARTING CENTRAL AND EASTERN WISCONSIN EARLY THIS AFTERNOON. AS THE RAIN DEPARTS SHOULD SEE CIGS GRADUALLY IMPROVE THROUGH THE REST OF THE AFTERNOON. THEN WILL SEE A WARM FRONT RETURN NORTHEAST LATE TONIGHT INTO THURSDAY MORNING WHICH HAS POTENTIAL TO BRING MVFR/IFR CIGS A CHANCE OF SHOWERS AND STORMS. THE CHANCE OF STORMS SHOULD MAINLY BE CONFINED TO CENTRAL AND NORTH-CENTRAL WISCONSIN THROUGH THE END OF THE TAF PERIOD. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......ESB AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1111 PM CDT TUE JUN 17 2014 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND WEDNESDAY ISSUED AT 238 PM CDT TUE JUN 17 2014 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE ASSOCIATED WITH LAST NITES CONVECTION MOVING EAST ACROSS LAKE HURON. A CONVECTIVE OUTFLOW BOUNDARY EXTENDS FROM THIS SURFACE LOW ACROSS NORTHERN ILLINOIS AND CENTRAL IOWA WHERE CUMULUS CLOUDS LOOK AGITATED. INSTABILITY HAS BEEN BUILDING THROUGH THE DAY OVER SOUTHWEST MINNESOTA AND SOUTHERN IOWA BUT CONSIDERABLE CONVECTIVE INHIBITION IS PREVENTING THE NEXT THUNDERSTORM COMPLEX FROM DEVELOPING SO FAR. FARTHER WEST...A SHORTWAVE TROUGH IS MOVING NORTHEAST OVER NEBRASKA WHERE WEAK LOW PRESSURE RESIDES. ACROSS NORTHERN WISCONSIN...CU IS BUILDING OVER NE WISCONSIN WHERE LOW LEVEL CONVERGENCE IS OCCURRING BUT PLENTY OF INHIBITION IS PRESENT THERE AS WELL. WITH THE NEXT THUNDERSTORM COMPLEX ANTICIPATED TO DEVELOP OVER THE NORTHERN MISSISSIPPI VALLEY THIS EVENING...THE THREAT OF SEVERE STORMS REMAINS THE MAIN FORECAST CONCERN. TONIGHT...A SHORTWAVE TROUGH OVER THE CENTRAL PLAINS WILL LIFT NORTHEAST TOWARDS THE NORTHERN MISSISSIPPI VALLEY THIS EVENING AND INTO THE WESTERN GREAT LAKES OVERNIGHT. THE APPROACH OF THE SHORTWAVE COMBINED WITH LIFT ON THE NOSE OF THE LLJ AND DESTABILIZATION OF THE MID-LEVELS SHOULD LEAD TO A THUNDERSTORM COMPLEX DEVELOPING OVER SOUTHERN MINNESOTA AND NORTHERN IOWA LATER THIS AFTERNOON OR EARLY THIS EVENING. THE LATEST NUMERICAL GUIDANCE SHOWS A VARIETY OF TRACKS OF THIS COMPLEX WITH THE NAM/ECMWF TRACKING IT TOWARDS NORTHERN ILLINOIS...WHILE THE MESOMODELS EXPANDING IT TOWARDS MILWAUKEE. SINCE THE LLJ AND ELEVATED INSTABILITY WILL BE DIRECTED TOWARDS SOUTHERN WISCONSIN AND NORTHERN ILLINOIS...A SOUTHEAST TRACK SEEMS MORE PROBABLE. HOWEVER...SOME THUNDERSTORMS MAY STILL MOVE INTO CENTRAL AND EAST-CENTRAL WISCONSIN LATE THIS EVENING AND OVERNIGHT WITH THE APPROACH OF THE SHORTWAVE TROUGH. ELEVATED INSTABILITY WILL BE AROUND 1K-1.5K J/KG WHILE EFFECTIVE BULK SHEARS WILL BE APPROX. 30 KTS. SO APPEARS THAT A LOW END SEVERE THREAT IS STILL POSSIBLE...IF THE MAIN COMPLEX DOES NOT CUT OFF MOISTURE INFLOW FROM THE SOUTH. HEAVY RAIN WILL BE ALSO POSSIBLE SOUTH OF ROUTE 29 WHERE PWATS WILL BE UPWARDS OF 1.5 INCHES. LOWS IN THE UPPER 50S NORTH TO MIDDLE 60S SOUTH. WEDNESDAY...THE SHORTWAVE TROUGH WILL BE EXITING EASTERN WISCONSIN DURING THE MORNING WHICH WILL KEEP THE CHANCE OF SHOWERS AND STORMS GOING THROUGH THE AM HOURS OVER CENTRAL AND NORTHEAST WISCONSIN. THINK PRECIP WILL BE EXITING BY LATE IN THE MORNING AND THEN WINDS WILL SHIFT TO THE NORTHEAST WHICH WILL BRING IN COOLER AIR OFF THE GREAT LAKES. EVEN THOUGH THE 850MB BOUNDARY WILL STALL OUT OVER SOUTHERN WISCONSIN....AM THINKING THAT THE COOLER AND MORE STABLE AIR WILL KEEP PRECIP CHANCES SMALLER THAN THE CURRENT FORECAST SHOWS. HIGHS RANGING FROM THE MID 70S EAST TO LOW 80S WEST...COOLER LAKE SIDE. .LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY ISSUED AT 238 PM CDT TUE JUN 17 2014 CONVECTIVE POTENTIAL WEDNESDAY NIGHT INTO THE WEEKEND CONTINUES TO BE THE MAIN CONCERN. EARLY IN PERIOD MODELS ALL TRENDING TOWARD PUSHING PCPN OFF TO THE WEST...WITH EAST WINDS OUT OF SURFACE HIGH OVER HUDSON BAY FILTERING IN DRIER AIR OVER THE REGION. PCPN CHANCES INCREASE AGAIN THU NIGHT/FRI AS LOW AND SURFACE TROF SHIFT EAST. NOT OVERLY IMPRESSED WITH CHANCES FOR SEVERE AT THIS TIME WITH WEAK LLVL JET AND SHEAR. PLENTY OF MOISTURE REMAINS OVER REGION WITH MAIN ISSUE AGAIN CHANCE FOR HEAVY RAIN. TEMPERATURES TO REMAIN AT OR ABOVE NORMAL. WEAKENING UPPER LOW WILL MOVE INTO THE WESTERN GREAT LAKES REGION OVER THE WEEKEND...LINGERING INTO EARLY NEXT WEEK. PCPN CHANCES TO CONTINUE. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1111 PM CDT TUE JUN 17 2014 THUNDERSTORMS ARE LIKELY ACROSS MUCH OF CENTRAL AND NORTHERN WISCONSIN OVERNIGHT WITH MVFR AND LOCAL IFR CONDITIONS. WHATEVER ACTIVITY IS LEFT EARLY WEDNESDAY SHOULD EXIT BY MIDDAY WITH MVFR OR VFR CONDITIONS WEDNESDAY AFTERNOON. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......TE AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1113 PM MDT THU JUN 19 2014 .UPDATE... ISSUED AT 1052 PM MDT THU JUN 19 2014 LATEST HIGH RES MODELS (HRRR...NSSL 4KM WRF...RAP13) SUGGEST THUNDERSTORMS MAY DEVELOP ALONG THE NOSE OF THE LOW LEVEL JET ACROSS THE FAR SOUTHEAST PLAINS. HRRR IS TARGETING KIOWA COUNTY...WHILE NSSL 4KM WRF HAS THIS OCCURRING JUST NORTH IN CHEYENNE COUNTY. CAPE INCREASES TO AROUND 1500 J/KG BETWEEN 06Z AND 09Z IF THE LOW LEVEL JET CAN BREAK THROUGH THE CAP...THEN AN ISOLATED STRONG THUNDERSTORM MIGHT BE POSSIBLY INTO EARLY FRIDAY MORNING. THERE DOES APPEAR TO BE A SUBTLE SHORTWAVE EMBEDDED IN THE FLOW ACROSS WESTERN CO WHICH WILL BE MOVING THROUGH EASTERN CO OVERNIGHT...THOUGH FORCING LOOKS PRETTY WEAK. HAVE ADDED SOME ISOLATED POPS ACROSS THE FAR EASTERN PLAINS THROUGH THE OVERNIGHT HOURS TO ACCOUNT FOR THIS POTENTIAL. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 323 PM MDT THU JUN 19 2014 CURRENTLY... MOSTLY CLEAR SKIES PREVAILED ACROSS THE REGION AT 2 PM...BEST MOISTURE WAS DOWN ALONG THE CO/NM BORDER REGION WITH DWPTS IN THE U40S AND L50S. TEMPS WERE QUITE A BIT COOLER THAN YDAY WITH LESS WIND....WITH TEMPS IN THE U70S/L80S PLAINS. REST OF TODAY... BEST CHANCE OF ANY PRECIP TODAY WILL BE ALONG THE RATON MESA REGION. WE COULD SEE SOME GUSTY WINDS AND SMALL HAIL AS PER LATEST SPC PROBABILITIES. ANY CONVECTION WILL BE ISOLD. TONIGHT... OVERALL...MOSTLY CLEAR SKIES ANTICIPATED. T/TD SPREADS ALONG THE BORDER ARE PRETTY LOW BUT THIS MSTR IS ONLY SKIN DEEP...SO DO NOT EXPECT ANY SIGNIF LOW CLOUDS. FOG NOT LIKELY AS LLVL JET WILL BE CRANKING TONIGHT OVER THE FAR E PLAINS. TOMORROW... BEST FORCING DURING THE AFTERNOON WILL BE ASSOCIATED WITH A TROUGH LYING NE-SW ACROSS THE FAR SE PLAINS ROUGHLY FROM KLAA TO KIM. MODELS ARE PERSISTENT AT BREAKING OUT SOME TSRA THIS AREA BY LATE IN THE AFTERNOON OVER THIS REGION. SHEAR PRETTY WEAK SO ORGANIZED CONVECTION NOT LIKELY...BUT STRONG WINDS AND SOME SMALL HAIL NOT OUT OF THE QUESTION. OVER THE REMAINDER OF THE REGION IT WILL BE PREDOMINANTLY DRY. IT WILL BE DRY TOMORROW WITH MAX TEMPS IN THE MID 90S ALONG THE LOWER ARK RVR VALLEY WITH U80S/L90S THE REST OF THE PLAINS...70S AND 80S VALLEYS AND MTNS. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 323 PM MDT THU JUN 19 2014 FRIDAY NIGHT AND SATURDAY...GENERAL W-SW FLOW ACROSS THE REGION WILL KEEP HOT CONDITIONS IN PLACE...WITH DIURNAL ISOLATED CONVECTION FOR THE MTS AND E PLAINS EACH EVE. FOR FRI EVE...CONVECTION IS FORECAST TO REMAIN OVER THE SE CORNER...BUT THEN BECOME MORE WIDESPREAD FOR SAT. LOOK FOR MAX TEMPS BOTHDAYS IN THE 90S FOR THE PLAINS AND 80S FOR THE HIGH VALLEYS...WITH MILD READINGS OVERNIGHT. SUNDAY THROUGH WEDNESDAY...A LOW PRES SYSTEM SLOWLY CROSSING CANADA IS EXPECTED TO PUSH COLD AIR DOWN INTO THE ROCKY MT REGION BEGINNING LATE SAT NIGHT. THIS PUSH OF COOL AND MORE MOIST AIR...IN ADDITION TO THE UPPER FLOW SHIFTING TO A MORE W-NW DIRECTION...IS EXPECTED TO BRING UPSLOPE CONDITIONS TO THE FORECAST AREA BEGINNING SUN AFTN/EVE. THIS WILL MEAN SLIGHTLY COOLER TEMPS AND A FAIRLY GOOD SHOT AT SOME PCPN FOR THE MTS AND E PLAINS LATE SUN THROUGH WED...BEFORE THE UPPER PATTERN SHIFTS AGAIN. MAX TEMPS EACH DAY ARE FORECAST TO BE IN THE 80S ACROSS THE PLAINS AND HIGH VALLEYS. THURSDAY...LONG RANGE MODELS INDICATE THAT HIGH PRESSURE WILL START TO STRENGTHEN OVER OLD MEXICO AND THE DESERT SW LATE WED...AND BE FIRMLY IN PLACE FOR THE CWA ON THU. MAINLY DRY CONDITIONS ARE FORECAST...ALONG WITH MAX TEMPS IN THE 90S FOR THE PLAINS AND IN THE LOWER 80S FOR THE HIGH VALLEYS. MOORE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1052 PM MDT THU JUN 19 2014 VFR CONDITIONS EXPECTED AT THE TAF SITES THROUGH THE NEXT 24 HOURS. WINDS WILL GRADUALLY SHIFT OUT OF THE NORTH FOR KCOS AND KPUB OVERNIGHT AT 5-10 KTS. WHILE NORTHWEST WINDS AROUND 10 KTS AT KALS WINDS WILL GRADUALLY DECREASE OVERNIGHT. SOUTH TO SOUTHEAST WINDS WILL INCREASE AGAIN ON FRIDAY AT 10-20 KTS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE TO THE EAST OF KCOS AND KPUB DURING THE AFTERNOON. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KT SHORT TERM...HODANISH LONG TERM...MOORE AVIATION...KT
AREA FORECAST DISCUSSION
NWS MIAMI FL
348 AM EDT FRI JUN 20 2014 .DISCUSSION...A WEAK LOW IS CENTERED OFF THE COAST AT CAPE CANAVERAL. THIS IS LEADING TO A LIGHT MEAN WESTERLY STEERING FLOW ACROSS SOUTH FLORIDA. ANOTHER ACTIVE DAY OF TSTORMS IS EXPECTED INTERIOR TO THE EAST COAST METRO AREAS AS A DEVELOPING ATLANTIC SEA BREEZE THIS AFTERNOON BUMPS UP AGAINST THE OPPOSING MEAN WESTERLY WIND FLOW. MOISTURE AND INSTABILITY LOOKS MORE THAN SUFFICIENT TO GET THINGS GOING SO THREW OUT THE LOW GFS MOS POP NUMBERS WHICH LOOK WAY TOO LOW. SIDED WITH NAM MOS AND HRRR WHICH SHOWS ACTIVE CONVECTION FOCUSED EAST COAST METRO. LATEST HRRR REALLY FOCUSES ACTIVITY ACROSS THE FORT LAUDERDALE AND MIAMI METRO AREAS LATE THIS AFTERNOON...WITH LESS ACTIVITY AT THE PALM BEACHES. NAM12 THOUGH FOCUSES CONVECTION FROM THE LAKE TO THE PALM BEACHES. ALTHOUGH I`M CONFIDENT TSTORMS WILL FOCUS EAST COAST METRO, THE EXACT PLACEMENT OF CONVECTION IS UNCERTAIN, SO DID NOT GET FANCY AND PLACED LIKELY POPS UP AND DOWN THE SE FLORIDA COAST THIS AFTERNOON. MAIN CONCERN WILL BE LOCALLY HEAVY RAINFALL AND STRONG WIND GUSTS. LOCALIZED URBAN FLOODING WILL BE POSSIBLE WHERE THE STRONGEST STORMS HIT...ESPECIALLY IF THEY HIT ACROSS AREAS WHICH SAW HEAVY RAINFALL YESTERDAY. WILL HIGHLIGHT THESE POTENTIAL HAZARDS IN THE MORNING HAZARDOUS WEATHER OUTLOOK. A TYPICAL SUMMERTIME PATTERN IS EXPECTED OVER THE UPCOMING WEEKEND AND NEXT WEEK WITH SCATTERED AFTERNOON TSTORMS EXPECTED TO DEVELOP EACH DAY. NO MAJOR SYNOPTIC SCALE FEATURES OF NOTE. THE FOCUS OF STORMS THIS WEEKEND STILL LOOKS TO FAVOR THE EASTERN HALF OF THE AREA...THEN FAVORING INTERIOR AREAS MOST OF NEXT WEEK AS THE RIDGE BUILDS IN AND WE GET INTO MORE OF A SE WIND FLOW PATTERN. GFS AND ECMWF CONTINUE TO DIFFER WITH RESPECT TO MOISTURE NEXT WEEK WITH ECMWF DRYING THINGS OUT MORE SO THAN THE GFS. GFS DOES SEEM TOO STRONG WITH AN INVERTED TROUGH MOVING OUT OF THE CARIB. IT`S HAD A STRONG BIAS ALL SEASON...SO NOT BUYING THIS. HAVE GONE WITH CHANCE POPS MOST LOCALES EACH DAY THROUGH NEXT WEEK...AS SEE NO REASON TO DEVIATE FROM THIS. /GREGORIA && .MARINE...LIGHT WINDS WILL PREVAIL LEADING TO A CONTINUATION OF LOW SEAS. MAIN HAZARD WILL BE LIGHTNING AND LOCALLY GUSTY WINDS IN AND NEAR TSTORMS. /GREGORIA && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 73 89 76 / 70 40 50 20 FORT LAUDERDALE 87 75 88 78 / 70 40 50 20 MIAMI 88 74 91 76 / 70 40 50 20 NAPLES 88 73 88 74 / 20 20 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
433 AM EDT FRI JUN 20 2014 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 359 AM EDT FRI JUN 20 2014 THE REGION REMAINS IN THE WARM SECTOR SOUTH OF A FRONTAL ZONE EXTENDING FROM THE CAROLINAS NORTHWEST TOWARD LOW PRESSURE OVER THE NORTHERN PLAINS AND UPPER MS VALLEY REGION. THE OVERALL FLOW ACROSS THE CONUS ATTM IS RATHER ZONAL IN NATURE WITH MID LEVEL RIDGING CENTERED OVER THE LOWER MS RIVER VALLEY...WITH LOW AMPLITUDE RIDGING NORTH TOWARD THE OH RIVER VALLEY. WELL TO THE NORTHEAST OF EAST KY... A MID LEVEL LOW AND ASSOCIATED SFC LOW THAT HAS HELPED TO PUSH THE BOUNDARY SOUTH ALONG THE EASTERN SEABOARD TO THE CAROLINAS REMAINS PLACE WHILE A CLOSED LOW IS WORKING ACROSS THE NORTHERN ROCKIES TOWARD THE NORTHERN PLAINS REGION ALONG US/CANADIAN BORDER. MEANWHILE...A SHORTWAVE TROUGH IS SLOWLY WORKING FROM THE PLAINS INTO THE MID MS AND LOWER OH VALLEY REGION. THE SHORTWAVE TROUGH WILL WORK INTO THE LOWER OH VALLEY REGION OVER THE NEXT FEW HOURS AND IS POISED TO MOVE ACROSS EASTERN KY AND INTO THE APPALACHIAN REGION LATE THIS AFTERNOON AND INTO THIS EVENING. AS THIS SHORTWAVE APPROACHES A SFC WAVE SHOULD DEVELOP AND WORK EAST SOUTHEAST ALONG THIS NEARLY STATIONARY BOUNDARY AND CROSS THE APPALACHIANS TONIGHT. THIS LOW SHOULD REACH THE EASTERN SEABOARD ON SATURDAY WITH THE TAILING COLD FRONT GRADUALLY SAGGING INTO EASTERN KY AND CROSSING MUCH OF THE AREA BY THE END OF THE PERIOD. THROUGH SHORTLY AFTER DAWN...PATCHY RIVER VALLEY FOG SHOULD REMAIN IN PLACE...WITH THIS FOG GRADUALLY BEGINNING TO LIFT AND POSSIBLY AFFECTING A FEW RIDGETOP LOCATIONS NEAR LOCATIONS THAT EXPERIENCED THE HEAVIER RAINFALL ON THU AND THU EVENING. THIS FOG SHOULD LIFT AND DISSIPATE SHORTLY AFTER DAWN. ALSO...THE NEAR TERM MODELS SUCH AS RECENT HRRR RUNS AND RECENT RAP RUNS HAVE SOME CONVECTION DEVELOPING NEAR SUNRISE BETWEEN JKL AND LOZ OR FROM ESTILL COUNTY SOUTH TO BELL COUNTY AND THEN MOVING EAST TO NEAR THE KY 15 CORRIDOR FROM JKL SOUTH TO THE VA BORDER AND THEN INTO FAR SOUTHEAST KY BEFORE NOON. THE 6Z NAM ALSO HAS SOME CONVECTION...BUT IS FURTHER EAST NEAR TO THE VA BORDER ACROSS THE BIG SANDY REGION. HOWEVER...EVEN IF THERE IS SOME MORNING CONVECTION...JUST A FEW HOURS OF THE STRONG JUNE SUNSHINE SHOULD BRING MID TO UPPER 80S SFC TEMPS WITH SFC DEWPOINTS IN THE MID 60S TO NEAR 70 DEGREE RANGE TO YIELD CAPE OF 2000 J/KG OR MORE BY MID TO LATE AFTERNOON. LAPSE RATES IN THE MID LEVELS WILL NOT BE PARTICULARLY STRONG AND RATHER WEAK SHEAR SHOULD LIMIT STORM ORGANIZATION. HOWEVER... A FEW CELLS...POSSIBLY SECOND AND THIRD GENERATION CELLS THAT DEVELOP NEAR OUTFLOW INTERSECTIONS COULD BECOME STRONG TO LOCALLY SEVERE AND PRODUCE STRONG TO LOCALLY DAMAGING WIND GUSTS. SPC HAS PLACED THE REGION IN A SEE TEXT AREA WITH 5 PERCENT PROBABILITIES FOR SEVERE THUNDERSTORM CRITERIA WINDS AND THIS APPEARS REASONABLE. THE MAIN THREAT FROM STORMS LATER TODAY AND TONIGHT MAY END UP BEING LOCALLY HEAVY RAINFALL RATES AS PW IS EXPECTED TO BE AT OR ABOVE THE 75TH PERCENTILE. THE PRESENCE OF THE SAGGING BOUNDARY AND THE POTENTIAL FOR CONVECTION TO TRAIN IN SOME AREAS AS THE STEERING FLOW MAY BECOME NEARLY PARALLEL TO THE SAGGING BOUNDARY OR OUTFLOWS COULD LEAD TO A LOCALIZED THREAT OF FLOODING. UNCERTAINTY REMAINS IN THE DETAILS AS FAR AS TIMING AND LOCATION. IN GENERAL...IT APPEARS THAT AS THE SHORTWAVE WORKS INTO EASTERN KY AND THE APPALACHIANS...CONVECTION SHOULD BE MOST WIDESPREAD DURING THE LATE AFTERNOON INTO LATE EVENING. THE HWO HAS BEEN ADJUSTED ACCORDINGLY FOR ALL OF THESE THREATS. THE THREAT OF SOME CONVECTION WILL LINGER EVEN INTO THE DAY ON SATURDAY AND WILL PROBABLY FEATURE A DIURNAL UPTICK IN CONVERGE. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 406 AM EDT FRI JUN 20 2014 THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A TYPICAL SUMMER PATTERN IN PLACE. A NEAR ZONAL UPPER LEVEL FLOW CONTINUES BUT WITH THE USUAL MID LEVEL RIDGE IN THE SOUTHEAST NOW SHIFTED TOWARDS THE WESTERN GULF OF MEXICO. BRIEF RIDGING WILL KEEP PRECIP MAINLY DIURNALLY DRIVEN AS THE BULK OF THE SUPPORT EXITS EASTERN KENTUCKY SATURDAY NIGHT...LEAVING ONLY SLIGHT CHANCE PRECIP INTO THE DAY ON SUNDAY WITH THE MAX HEATING. BY MONDAY...A SIGNIFICANT SHORTWAVE MOVES ACROSS THE PLAINS AND INTO THE OH VALLEY. THIS WAVE WILL BE THE FOCUS OF ACTIVE WEATHER THROUGH THE MID PORTION OF THE EXTENDED. THE MENTIONED WAVE PUSHES THROUGH ON MONDAY NIGHT AND TUESDAY PUSHING A SURFACE COLD FRONT THROUGH. THIS FORCING AND THE WAVE MOVING THROUGH WILL PROVIDE THE BEST CHANCE OF PRECIP ON TUESDAY AND INTO TUESDAY NIGHT. THE EURO HINTS AT THE FRONT STALLING AND BECOMING AN EAST WEST STATIONARY BOUNDARY ALONG SOUTHERN KY BY THE WED AND THU TIME FRAME. THIS BECOMES AN POINT OF DEVELOPING CONVECTION THROUGH THE LAST COUPLE DAYS OF THE EXTENDED. THE CHANCES WITH THIS SET UP BECOME DIURNALLY DRIVEN WITH THE HEATING OF THE DAY. THE LACK OF CONTINUITY OF GUIDANCE AND NEED TO STAY CONSISTENT WITH THE NEIGHBORING OFFICES...LEAD TO KEEPING VALUES CLOSER TO THE ALL MODEL BLEND SOLUTION. THE MONDAY THROUGH TUESDAY NIGHT PERIOD REMAINS A PERIOD TO WATCH WITH THE STRONG WAVE MOVING THROUGH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 200 AM EDT FRI JUN 20 2014 OUTSIDE OF LOCATIONS WITH VALLEY FOG CONDITIONS ACROSS THE REGION WERE MOSTLY VFR. VALLEY FOG WILL CONTINUE TO DEVELOP THOUGH CURRENT DEWPOINT DEPRESSIONS ARE RELATIVELY HIGH AT SME AND LOZ TAF SITES. VALLEY FOG SHOULD LIFT TOWARD DAWN AT THE JKL AND SJS TAF SITES FROM NEARBY VALLEYS. OTHERWISE...THE THICKEST VALLEY FOG SHOULD OCCUR BEING IN AREAS WHERE RAIN FELL. ANY FOG SHOULD DISSIPATE BY 13Z. SOME ADDITIONAL SHRA/TSRA CANNOT BE RULED OUT AFTER ABOUT 8Z OR 9Z...BUT THE PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS UNTIL CLOSER TO 15Z TO 16Z. HOWEVER...TIMING IS UNCERTAIN...AND ONLY VCTS HAS BEEN USED IN TAFS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JP LONG TERM...SHALLENBERGER AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
231 AM EDT FRI JUN 20 2014 .UPDATE... ISSUED AT 200 AM EDT FRI JUN 20 2014 HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT SATELLITE AND RADAR TRENDS. THE RECENT HRRR AND RAP RUNS HAVE ALSO BEEN FACTORED IN. CONVECTION HAS DWINDLED OVERNIGHT AND THIS TREND SHOULD CONTINUE OVER THE NEXT COUPLE OF HOURS. HOWEVER...SOME OF THE GUIDANCE POINTS TOWARD SOME REDEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS JUST PRIOR TO DAWN. OTHERWISE...SOME VALLEY LOCATIONS SUCH AS I35 ARE EXPERIENCING DENSE FOG AND OTHER VALLEY LOCATIONS WILL LIKELY FOLLOW AS LONG AS THE CLOUD COVER CONTINUES TO THIN. UPDATE ISSUED AT 1051 PM EDT THU JUN 19 2014 EARLIER CONVECTION HAS LEFT ONLY A BIT OF LIGHT RAIN AS A REMNANT... AND THIS WAS ON THE DECLINE. THE HRRR...RUC...AND NAM FROM THIS EVENING ALL STILL SUGGEST SOME LIMITED REDEVELOPMENT OF CONVECTION OVERNIGHT IN THE WARM AIR ADVECTION REGIME. THERE ARE SOME CELLS WHICH HAVE POPPED UP OVER SOUTH CENTRAL KY. WILL LEAVE LOW POPS IN PLACE OVERNIGHT. UPDATE ISSUED AT 853 PM EDT THU JUN 19 2014 CONVECTIVE DEVELOPMENT TRENDS HAVE BEEN DIFFICULT TO PIN DOWN THIS AFTERNOON AND EVENING. THE LATEST AREA OF ORGANIZED STORMS TO DEVELOP HAVE BEEN JUST NORTH OF THE MOUNTAIN PARKWAY NEAR/AHEAD OF THE REMNANT OUTFLOW BOUNDARY FROM EARLIER CONVECTION FURTHER NORTH...WHICH IS ALSO THE EFFECTIVE FRONTAL BOUNDARY. HAVE SET AN AREA OF LIKELY POPS FOR THIS FOR A COUPLE OF HOURS AS THE CONVECTION DRIFTS/DEVELOPS SOUTHWARD. STILL THINK THAT ACTIVITY WILL BE ON AN OVERALL DECLINE THIS EVENING WITH LOSS OF HEATING. MODELS TRY TO SHOW SOME REDEVELOPMENT OVERNIGHT IN A WEAK WARM AIR ADVECTION REGIME SENDING THE FRONT BACK NE. CONFIDENCE FOR PRECIP OVERNIGHT IS LOW...AND THE EXISTING LOW POPS FOR THE OVERNIGHT HOURS SEEM REASONABLE. UPDATE ISSUED AT 602 PM EDT THU JUN 19 2014 CONVECTION HAS BEEN ON THE INCREASE OVER THE NORTHEAST PART OF THE JKL FORECAST AREA...WHERE A NUMBER OF OUTFLOW BOUNDARIES ARE CONVERGING. HAVE RAISED POPS TO 50 PERCENT FOR THE NEXT OUR OR TWO FOR THAT AREA. IN ADDITION...A LINE OF CONVECTION HAS BEEN SLOWLY SINKING SW IN INDIANA AND OHIO THIS AFTERNOON. HOWEVER...ALONG THE PORTION NEAR THE OHIO RIVER...THE OUTFLOW APPEARS TO BE MOVING FURTHER OUT AHEAD OF THE STORMS...AND THE CONVECTIVE LINE IS LOOKING MORE BROKEN AND LESS INTENSE THAN EARLIER. WITH THESE TRENDS...IT IS QUESTIONABLE HOW INTACT IT WILL BE IF IT MAKES IT TO THE JKL FORECAST AREA. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 435 PM EDT THU JUN 19 2014 ISOLD TO SCATTERED CONVECTION CONTINUES TO FIRE ACROSS PORTIONS OF THE FORECAST AREA THIS AFTERNOON. A COUPLE STORMS HAVE BEEN SHOWING SOME FAIRLY STRONG SIGNATURES...BUT HAVE NOT SEEN MUCH IN THE WAY OF WINDS AND NO REPORTS OF HAIL. BUT THE NATURE OF THE COVERAGE MAY BE LIMITING REPORTS. STRONGEST CONVECTION ATTM IS LOCATED IN OUR NORTHEASTERN COUNTIES...ALONG ONE OF THE PREDOMINANT BOUNDARIES. SOME CONVECTION HAS BEEN TRIGGERED IN THE WEST AS WELL...ALONG AN OUTFLOW THAT IS PUSHING TO THE EAST. THESE OUTFLOWS HAVE BEEN STABILIZING THE BOUNDARY LAYER AS THEY PASS THROUGH ANY GIVEN AREA...AND IT HAS BEEN TAKING TIME FOR THE SUN TO HEAT THINGS UP ENOUGH TO GET ADDITIONAL INSTABILITY FOR REDEVELOPMENT. WITH SUNSET APPROACHING AND A THICKER CIRRUS SHIELD MOVING UP FROM THE SOUTH... EXPECT CONVECTION WILL BECOME MORE LIMITED WITH TIME THROUGH THE REMAINDER OF THE LATE AFTERNOON AND EARLY EVENING HOURS. SHOWERS AND THUNDERSTORMS WILL REDEVELOP TOMORROW AS A FRONTAL SYSTEM APPROACHES FROM THE WEST. ANY THUNDERSTORMS THAT DO DEVELOP COULD DISPLAY SOME STRONG CHARACTERISTICS AND CAN NOT RULE OUT A SEVERE STORM OR TWO. WE COULD ALSO SEE SOME HEAVY RAINERS...ESPECIALLY AS WE GET INTO FRIDAY AND FRIDAY EVENING. PWATS ARE HIGH CLIMATOLOGICALLY SPEAKING AND STORM MOTION ARE RELATIVELY LOW...5-10KTS. FREEZING LEVELS REMAIN HIGH BETWEEN 14-15K AS WELL. SO WARM WATER PROCESSES COULD BE A FACTOR AS WELL. ALSO...THREAT WOULD BE HIGHER WHERE ANY BOUNDARIES SET UP...SHOULD THAT LEAD TO TRAINING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 316 PM EDT THU JUN 19 2014 EASTERN KY WILL FIND ITSELF ON THE BACK EDGE OF A DEAMPLIFIED RIDGING PATTERN AT THE BEGINNING OF THE PERIOD /12Z SATURDAY/...WITH A SHORTWAVE PASSING THROUGH THE REGION AND A SURFACE BOUNDARY IN THE FORM OF A BACKDOOR COLD FRONT CAUSING SHOWERS AND THUNDERSTORMS TO LINGER...ESPECIALLY ACROSS THE SE PORTION OF THE CWA. THE NAM IS THE ONLY MODEL AT THIS POINT WHICH DOES NOT PUT PRECIP COVERAGE ACROSS MUCH OF THE CWA...SO HAVE SLIGHTLY LOWER CONFIDENCE DURING THIS TIME PERIOD FOR THE MODEL. EXPECT BEST COVERAGE TO BE IN THE MORNING...THEN TAPERING OFF AS THE SURFACE LOW SLOWLY PUSHES SOUTHWARD. CHANCES WILL LINGER LONGEST OVER THE SE PORTION OF THE STATE WITH LINGERING LOW LEVEL MOISTURE AND UPSLOPE FLOW. THE UPPER LEVEL SHORTWAVE WILL CONTINUE TO SLOWLY SLIDE EASTWARD SATURDAY NIGHT AND SUNDAY...AS THE OVERALL UPPER FLOW BECOMES SLIGHTLY MORE ZONAL. THIS WILL ELIMINATE THE BEST PRECIP CHANCES OVERNIGHT SATURDAY...THOUGH LINGERING MOISTURE AND DAYTIME INSTABILITY COULD POP UP SOME MORE DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS DURING THE DAY SUNDAY. A MORE NORTHERLY FLOW BOTH SATURDAY AND SUNDAY WILL KEEP DAYTIME TEMPERATURES SLIGHTLY COOLER THAN PREVIOUS DAYS...IN THE LOW TO MID 80S ACROSS MUCH OF THE CWA. DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS COULD BE POSSIBLE INTO THE DAY MONDAY AS WELL...WHILE WEAK UPPER LEVEL RIDGING REMAINS OVERHEAD. HOWEVER...BOTH THE GEM AND ECMWF ARE ONLY SHOWING DEVELOPMENT ACROSS THE FAR SE COUNTIES...WHILE THE GFS IS SHOWING A VAST AMOUNT OF PRECIP ACROSS MUCH OF KENTUCKY. GIVEN THE SYNOPTIC SET UP...WOULD CHOSE TO SIDE CLOSER TO THE ECMWF...WITH THE GFS PULLING IN AN UNREALISTIC AMOUNT OF MOISTURE ACROSS THE REGION. BY LATE MONDAY...AN UPPER LEVEL LOW IN SOUTH CENTRAL CANADA WILL BEGIN TO DEEPEN...PULLING A DEEPENING TROUGH INTO THE MISSISSIPPI RIVER VALLEY OVERNIGHT MONDAY NIGHT. AS THIS LOW SHIFTS EASTWARD... EXPECT A SURFACE LOW AND BOUNDARY TO IMPACT THE REGION DURING THE DAY TUESDAY. MODELS AT THIS POINT ARE CONTINUING TO DISAGREE IN THEIR SOLUTIONS...SO WILL STICK CLOSE TO A BLEND OF SOLUTIONS FROM THIS POINT FORWARD. AS THIS SYSTEM APPROACHES...SOUTHERLY FLOW WILL REESTABLISH ITSELF...BRINGING IN A WARMER AND MORE HUMID/UNSTABLE AIR MASS. SHOWERS AND THUNDERSTORMS COULD BE POSSIBLE FROM TUESDAY WELL INTO THE DAY WEDNESDAY AS THE SURFACE FRONT BECOMES MORE WEST TO EAST ORIENTED ACROSS KENTUCKY. A BRIEF BREAK MIGHT BE FELT SOMETIME EARLY THURSDAY...HOWEVER ANOTHER SHORTWAVE WILL BE FAST TO BRING YET ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS TO FINISH OUT THE 7 DAY FORECAST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 200 AM EDT FRI JUN 20 2014 OUTSIDE OF LOCATIONS WITH VALLEY FOG CONDITIONS ACROSS THE REGION WERE MOSTLY VFR. VALLEY FOG WILL CONTINUE TO DEVELOP THOUGH CURRENT DEWPOINT DEPRESSIONS ARE RELATIVELY HIGH AT SME AND LOZ TAF SITES. VALLEY FOG SHOULD LIFT TOWARD DAWN AT THE JKL AND SJS TAF SITES FROM NEARBY VALLEYS. OTHERWISE...THE THICKEST VALLEY FOG SHOULD OCCUR BEING IN AREAS WHERE RAIN FELL. ANY FOG SHOULD DISSIPATE BY 13Z. SOME ADDITIONAL SHRA/TSRA CANNOT BE RULED OUT AFTER ABOUT 8Z OR 9Z...BUT THE PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS UNTIL CLOSER TO 15Z TO 16Z. HOWEVER...TIMING IS UNCERTAIN...AND ONLY VCTS HAS BEEN USED IN TAFS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...RAY LONG TERM...JMW AVIATION...JP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
437 AM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT FRI JUN 20 2014 FIRST CONCERNS IS DENSE FOG ADV ACROSS MPX CWA. SECONDARY CONCERN IS ISOLD/SCT CONVECTION ALONG AN INSTABILITY AXIS MOVING ACROSS MN THIS AFTN. PLENTY OF RAINFALL OVER THE LAST 24 HRS FOR BOUNDARY LAYER TO SATURATE. HOWEVER...BOUNDARY LAYER WINDS INCREASED SLIGHTLY AFT MIDNIGHT ALLOWING FOR MAINLY LOW STRATUS AND PATCHY DENSE FOG ACROSS SC MN...BUT THE MAJORITY OF MPX CWA HAD PATCHY FOG WITH LOCALIZED DENSE FOG WHERE CIGS DROPPED TO 100-200`. BASED ON CURRENT VIS/FOG SATELLITE IMAGERY AND BOUNDARY LAYER WINDS ARND 5-10 KTS ANTICIPATE THAT THE DENSE FOG ADV WILL BE CANCELLED EARLY...PROBABLY BEFORE SUNRISE. WILL MONITOR FOR ANY NEW DEVELOPMENT ACROSS SC/EC MN FOR CIGS/VSBYS DROPPING LOWER...BUT THIS IS NOT EXPECTED TO CAUSE WIDESPREAD DENSE FOG...ONLY PATCHY DENSE FOG. A COUPLE OF ITEMS TO NOTE EARLY THIS MORNING FOR THE POTENTIAL OF CONVECTION THIS AFTN. FIRST...A WEAK SHRTWV ROTATING ARND THE SOUTHERN PART OF THE MAIN UPPER LOW ACROSS SOUTH CENTRAL CANADA WILL LIKELY PROVIDE SOME LIFT LATER THIS AFTN ACROSS MN. RUC DOES SHOW 85/92H WINDS BECOMING MORE SSW/SW THIS AFTN ACROSS NE/SD WHICH WILL PULL RESIDUAL MOISTURE ACROSS KS/CO NE INTO SW MN DURING THE AFTN. MLCAPES AND MLCIN REFLECT THE CHC/S THIS AFTN IN A THIN BAND FROM SW TO CENTRAL MN. DUE TO WEAK SFC CONVERGENCE AND GREATER SHRTWV STRENGTH ACROSS NORTHERN MN...ONLY ISOLD/SCT SHRA/TSRA WILL BE POSSIBLE. 20-30% SEEMS REASONABLE AT THIS TIME. LATER SHIFTS WILL NEED TO MONITOR FOR HIGHER MOISTURE ADVECTING NE ACROSS S MN. THE SAME SW WINDS IN THE FIRST 5K ACROSS SD AND INTO WC MN THIS AFTN MAY CAUSE ENOUGH MIXING TO HAVE TEMPS RISE INTO THE LOWER 90S. BUT BASED ON THE WET SOIL CONDS AND DEW PTS IN THE 50S/60S...AM LEANING TOWARD MID TO UPPER 80S AT THIS TIME. TONIGHT WILL LIKELY SEE THE CONVECTION DECREASING RAPIDLY AFT SUNSET WITH MOST OF THE ACTION SOUTH OF THE MN AS THE LLJ DEVELOPS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 347 AM CDT FRI JUN 20 2014 THERE COULD BE AN ONGOING MCS IN NORTHEAST NE OR NORTHERN IA COME 12Z SATURDAY MORNING WITH THE AFOREMENTIONED INCREASING LLJ...BUT THE 850-300MB WINDS AND THICKNESS PATTERN SUGGEST ANY ORGANIZED /OR UNORGANIZED CONVECTION FOR THAT MATTER/ SHOULD TRACK E-SE WITH TIME AND REMAIN SOUTH OF THE FORECAST AREA THROUGH THE MORNING HOURS. EVEN MOST OF THE CLOUD DEBRIS SHOULD BE CARRIED DOWNSTREAM TO THE EAST. THE NAM/GFS/ECMWF ALL SEEM TO BE DEPICTING A WEAK TROUGH IN WESTERN WI AND LIGHT QPF. THE SOUNDINGS ARE FAIRLY DRY ON SATURDAY AND THERE ISN`T A CLEAR TRIGGER OUTSIDE OF PERHAPS A WEAK MID LEVEL WAVE IN IA. THERE IS MODEST ELEVATED INSTABILITY AND EVEN THE ECMWF DOES HINT AT CONVECTIVE INITIATION...BUT THE SHOWER/THUNDER CHANCES LOOK BETTER SOUTH AND EAST OF THE FORECAST AREA. SUNDAY IS PERHAPS A LITTLE MORE INTERESTING AND SUGGESTS A NEED FOR SLIGHTLY HIGHER POPS AS AN ADVANCING SURFACE BOUNDARY TRIES TO MAKE IT ACROSS MINNESOTA DURING THE DAY WITH A SHORTWAVE APPROACHING FROM THE CENTRAL PLAINS. ALTHOUGH PERHAPS A LITTLE OVERDONE WITH SURFACE DEWPOINTS...BOTH THE NAM-GFS HAVE LARGE MUCAPE VALUES OF 3000-5000 J/KG IN SOUTHERN MINNESOTA. THE SHEAR PROFILE IS WEAK...WHICH WILL SUPPRESS THE THREAT FOR SEVERE WEATHER. THERE IS ALSO UNCERTAINTY AS TO HOW MUCH CONVECTION THERE WILL BE...BUT GIVEN THE LARGE AMOUNT OF INSTABILITY...PULSE STORMS AND SMALL MULTICELL CLUSTERS COULD STILL POSE A MARGINAL SEVERE THREAT IF EVERYTHING PANS OUT. THE BEST CHANCE FOR MORE WIDESPREAD RAIN IN THE AVAILABLE MODEL GUIDANCE IS MONDAY AFTERNOON INTO EARLY TUESDAY MORNING WITH A DEVELOPING SURFACE CYCLONE TRACKING OUT OF THE SOUTHERN PLAINS AND DEEPENING WITH TIME AS IT HEADS TOWARD IA/WI. THERE IS A BIT MORE CONFIDENCE IN PRECIP AT LEAST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA BECAUSE THE GFS/ECMWF SOLUTIONS HAVE SETTLED DOWN OVER THE PAST 3-4 MODEL CYCLES. PREVIOUS RUNS THIS WEEK WERE ALL OVER THE PLACE WITH PLACEMENT AND TIMING. OTHERWISE WE`LL REMAIN IN A FAIRLY INNOCUOUS /AT LEAST COMPARED TO THE HEAVY RAIN PATTERN WE`VE BEEN IN RECENTLY/ WESTERLY FLOW THROUGH NEXT WEEK WITH NO BIG SYSTEMS...SEVERE WEATHER OUTBREAKS...BIG TEMPERATURES SWINGS...ETC. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1211 AM CDT FRI JUN 20 2014 LIFR CONDITIONS DUE TO CIGS HAVE BEGUN TO DEVELOP OVER PORTIONS OF CENTRAL MN...WITH OTHER AREAS STILL WELL ABOVE VFR THRESHOLDS. AS MID LEVEL CLOUDS CLEAR ACROSS EASTERN MINNESOTA AND FAR WESTERN WISCONSIN...THINK STRATUS AND/OR DENSE FOG WILL FORM WITH NEARLY ALL TAF SITES IFR OR LOWER BY MORNING. RAPID IMPROVEMENT WILL TAKE PLACE MID MORNING AS TEMPERATURES WARM INTO THE 70S. THEREAFTER... VFR CONDITIONS EXPECTED. KMSP...TOUGH CALL FOR MSP AS USUAL FOR FOG DEVELOPMENT AND HOW LOW VISIBILITIES WILL EVENTUALLY GET. CURRENT TAF CALLS FOR MVFR VIS WITH TEMPORARY REDUCTIONS OF IFR LEVELS...BUT CONFIDENCE IS NOT ALL THAT HIGH. AMENDMENTS WILL BE ISSUED OVERNIGHT AS NEEDED. /OUTLOOK FOR KMSP/ SAT...VFR. MVFR ISO SHRA/TSRA POSSIBLE. WINDS SW 5-10 KTS. SUN...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS ESE 5 KTS BECMG WNW 5-10KTS. MON...VFR. WINDS NW 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR MNZ074>077- 082>085-091>093. WI...NONE. && $$ SHORT TERM...JLT LONG TERM...CLF AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
347 AM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT FRI JUN 20 2014 THE NAM AND RAP SHOW AN AREA OF MIDLEVEL CLOUDS ACROSS ERN COLO THIS MORNING BECOMING CONVECTIVELY ACTIVE 09Z-12Z THIS MORNING. THE DISTURBANCE SHOULD MOVE EAST THRU SRN NEB THIS AM PRODUCING A CLUSTER OF ELEVATED TSTMS. THE RAP INDICATES 750MB CAPE OF AROUND 1000 J/KG SUGGESTING THE POTENTIAL FOR SOME HAIL. THIS ACTIVITY DISSIPATES LATE THIS MORNING TO BE FOLLOWED BY A SECOND AREA OF TSTM DEVELOPMENT FROM ROUGHLY KIML NORTHEAST THROUGH KONL THIS AFTN WITH THE BETTER RAIN CHANCES FROM HAYES CENTER NORTHEAST THROUGH KONL. BUFKIT SUGGESTS A WEAK MULTICELL ENVIRONMENT GIVEN THE WEAK SHEAR AROUND 25 KT. MLCAPE THOUGH AROUND 3000 J/KG IN THE RAP MODEL SUGGESTS SOME STRONG UPDRAFTS DEVELOPING THIS AFTN NEAR OR SOUTH OF KOGA AND KLBF. SO SEVERE WEATHER CHANCES CONTINUE ALTHOUGH THE POTENTIAL FOR LONGER LIVED STORMS WOULD APPEAR LOW. STORMS WILL LIKELY FIRE FROM SOUTHWEST NEB TO NCNTL NEB THIS AFTERNOON AND THIS EVENING AND COALESCE INTO CLUSTERS WHICH MOVE OFF EAST OF THE FCST AREA AROUND 06Z. POPS ARE LIMITED TO 40 PERCENT GIVEN THE WEAKNESS IN THE WINDS ALOFT AND LOW QPF GENERATED BY THE MODELS. HIGHS TODAY RISE INTO THE 80S AND LOWS TONIGHT FALL INTO THE 50S TO LOWER 60S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 325 AM CDT FRI JUN 20 2014 MOIST...WARM AND UNSTABLE CONDITIONS WILL CONTINUE ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA SATURDAY. MODELS ALL AGREE THAT A WARM FRONT WILL BE LOCATED IN AN EAST TO WEST FASHION...BUT DISAGREE ON THE LOCATION. REGARDLESS...IT APPEARS THAT SCATTERED TSTMS WILL INITIATE ACROSS THE HIGH PLAINS IN MOIST UPSLOPE REGIME. THESE WILL LIKELY BEGIN AS SUPERCELLS WITH BULK SHEAR NEAR 40 KTS. BUFKIT DATA FROM VARIOUS LOCATIONS ACROSS THE PLAINS SUGGESTS RIGHT TURNING SUPERCELLS THE DOMINATE STORM MODE AT FIRST...THEN CONGEAL INTO ONE OR MORE CLUSTERS SATURDAY NIGHT AS SOUTHERLY LOW LEVEL JET INCREASES. THE WARM FRONT LOCATION WILL HAVE TO BE MONITORED...AS WINDS WILL BE BACKED MORE TO THE EAST ON THE NORTH SIDE OF THE BOUNDARY...WHICH WILL ENHANCE LOW LEVEL SHEAR AND POSSIBLE TORNADO DEVELOPMENT. SUNDAY A SHORTWAVE DISTURBANCE WILL TRACK ACROSS THE NORTHERN ROCKIES AND TOWARD THE NORTHERN PLAINS. A SURFACE LOW WILL DEEPEN ACROSS EASTERN COLORADO IN RESPONSE...WITH MOIST EAST TO NORTHEAST WINDS ACROSS MOST OF WESTERN AND NORTH CENTRAL NEBRASKA TO THE NORTH OF THE LOW. STORM DEVELOPMENT WILL BE AIDED BY THE SHORTWAVE DISTURBANCE ACROSS THE PANHANDLE SUNDAY AFTERNOON...WITH STORMS LIKELY MERGING INTO AN MCS AS THEY TRACK EAST SOUTHEAST ACROSS NEBRASKA SUNDAY EVENING. LOCALLY HEAVY RAIN COULD MATERIALIZE AND POTENTIAL WILL HAVE TO BE MONITORED. MONDAY INTO TUESDAY...SOMEWHAT COOLER AND DRIER BEHIND THE SHORTWAVE DISTURBANCE. BY MIDWEEK...RICH GULF MOISTURE RETURNS. MODELS INDICATING DEW POINTS IN THE UPPER 60S TO NEAR 70 FOR MUCH OF THE FORECAST AREA BY WEEKS END. THATS WHEN TSTM CHANCES MAY INCREASE ONCE AGAIN...AS UPPER LEVEL TROUGHING DEVELOPS INTO THE PACIFIC NORTHWEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1227 AM CDT FRI JUN 20 2014 THE RAP AND NAM MODELS SHOW A CLUSTER OF TSTMS DEVELOPING ACROSS SWRN NEB AROUND 10Z. THESE STORMS SHOULD MOVE OFF TO THE EAST 12Z- 15Z AND REMAIN SOUTH OF INTERSTATE 80. WITH CLEAR SKY AND RESIDUAL MOISTURE FROM THE HEAVY RAINS LAST NIGHT...LOCALIZED FOG IS A FORECAST CONCERN FOR CENTRAL AND SOUTHWEST NEBRASKA INCLUDING BBW...LBF AND OGA. CURRENT WIND IN THE PLATTE RIVER VALLEY IS 140-160 AT 4-6KT WHICH COULD SUPPORT A FORECAST FOR FOG AT LBF IF IT DECREASES TO 4KT OR LOWER AND ALSO NORTHWEST AND SOUTHEAST OF LBF. SURFACE DEWPOINTS UPWIND OF LBF ARE IN THE UPPER 50S. HOWEVER...THE DEPTH OF THE MOISTURE JUST OFF THE SURFACE IS LIKELY TO BE INSUFFICIENT FOR CREATING A SATURATED LAYER IN THE LOWEST 1000 FEET ABOVE THE SURFACE AND WIDESPREAD FG/BR. STILL...IN A FAIRLY NARROW BBW-LBF-OGA SWATH...VERY HEAVY RAIN FROM STORMS LAST NIGHT MAY HAVE LEFT ENOUGH STANDING SURFACE WATER TO SATURATE THE COOL NEAR-SURFACE LAYER IN PLACES AND MAY PRODUCE SPOTTY MIST OR FOG. WHEREVER MIST/FOG MAY DEVELOP...THE VISIBILITY MAY BE REDUCED TO 1SM OR LOWER. CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE BR/FG IN THE TERMINAL FORECAST FOR LBF. IN THE REST OF THE AREA...CEILING AND VISIBILITY IS LIKELY TO BE UNLIMITED. THUNDERSTORMS ARE POSSIBLE FRIDAY AFTERNOON AND EVENING SOUTH AND EAST OF AN ONL-OGA LINE. THAT LINE MARKS A CONTRAST BETWEEN MOIST UNSTABLE AIR IN THE SOUTH AND DRY AIR TO THE NORTH. HOWEVER...THE THUNDERSTORM COVERAGE IS LIKELY TO BE LIMITED TO 30 PERCENT OR LESS. THAT RESULTS IN A LOW PROBABILITY OF A THUNDERSTORM AT ANY PARTICULAR SITE. WIND ON FRIDAY IS EXPECTED TO BE 260-290 AT 12-14G21-22KT IN NORTHERN NEBRASKA BY 17Z. AIRPORTS THAT ARE LIKELY TO BE AFFECTED INCLUDE ONL...ANW...VTN...TIF AND MHN. WIND IN THE REST OF THE AREA WILL BE 170-210 AT LESS THAN 12KT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1229 AM CDT FRI JUN 20 2014 .SYNOPSIS... ISSUED AT 350 PM CDT THU JUN 19 2014 UPPER CLOSED LOW OVER MONTANA SHEARING INTO SOUTHERN CANADA THIS AFTERNOON. UPPER RIDGE THROUGH HUDSON BAY. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 350 PM CDT THU JUN 19 2014 PRIMARY CONCERN FOR THIS PORTION OF THE FORECAST IS ON LOW TEMPERATURES TONIGHT AND SHOWER AND THUNDERSTORM CHANCES ON FRIDAY. AT 19Z WATER VAPOR IMAGERY SHOWED THE UPPER LEVEL LOW CENTERED OVER SOUTHWEST SASKATCHEWAN WITH A STRONG SHORTWAVE TROUGH MOVING NORTHEAST ACROSS WESTERN SOUTH DAKOTA. THERE WAS A GOOD FETCH OF DRY AIR PULLING UP INTO THE SYSTEM...WHICH WAS SEEN OVER NEBRASKA. THIS DRY AIR WAS SEEN ON VISIBLE SATELLITE...WHERE SUNNY SKIES WERE OBSERVED OVER MUCH OF THE STATE. SURFACE ANALYSIS SHOWED THE COLD FRONT FROM CENTRAL NORTH DAKOTA THROUGH WESTERN IOWA...ACROSS SOUTHEAST NEBRASKA AND INTO CENTRAL KANSAS. HIGH PRESSURE WAS CENTERED OVER SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. THE AIRMASS DIFFERENCES WERE QUITE APPARENT WITH DEWPOINTS AHEAD OF THE FRONT IN THE UPPER 60S AND 70S...WITH DEWPOINTS BEHIND THE FRONT MOSTLY IN THE 30S-50S. TEMPERATURES WERE COOLER AS WELL...WITH TEMPERATURES AT MID AFTERNOON IN THE 70S AND LOW 80S. THE UPPER LEVEL LOW WILL MIGRATE EAST ALONG THE CANADA BORDER THROUGH THE DAY FRIDAY...WITH THE MODELS IN DECENT AGREEMENT WITH IT LIFTING SLIGHTLY NORTH BY THE END OF THE DAY...CENTERED OVER SOUTHERN MANITOBA. WITH PLENTIFUL DRY AIR IN PLACE TONIGHT...CLEAR SKIES WILL BE SEEN ACROSS THE REGION. WINDS WILL DROP OFF AND WITH THE COOLER AIRMASS IN PLACE LOOKING FOR LOWS FROM THE LOW 50S TO THE LOW 60S. FOR FRIDAY THE 12Z AND 18Z MODEL RUNS ARE NOW INDICATING A VERY SUBTLE SHORTWAVE WILL MOVE ACROSS SOUTHERN NEBRASKA AND KANSAS DURING THE DAY FRIDAY. WARM AIR ADVECTION WILL OCCUR DURING THE DAY ALONG WITH MOISTURE RETURN IN THE LOW LEVELS AS A SURFACE LOW DEVELOPS OVER EASTERN COLORADO. IT APPEARS THAT THERE WILL BE AN INVERTED TROUGH FROM THAT SURFACE LOW THROUGH NORTH CENTRAL NEBRASKA. THIS ADDED MOISTURE SHOULD HELP CONVECTION DEVELOP ALONG AND EAST OF THE BOUNDARY IN THE AFTERNOON AS THE SHORTWAVE ENERGY PASSES. GOOD INSTABILITY IS BEING INDICATED BY THE MODELS IN THESE AREAS...WITH SB CAPE UP TO 3500 J/KG IN SOME AREAS AT THE TIME OF PEAK HEATING. DEEP LAYER WIND SHEAR ISN/T OVERLY STRONG...BUT 30 TO 35KTS WITH THE AMOUNT OF INSTABILITY INDICATED SHOULD BE SUFFICIENT FOR AT LEAST A FEW STRONG STORMS. THE BEST CHANCES FOR STORMS LOOKS TO BE EAST OF A LINE FROM OGALLALA TO AINSWORTH. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 350 PM CDT THU JUN 19 2014 CLOSED LOW OVER SOUTHWEST CANADA WILL CONTINUE TO AFFECT WEATHER OVER NORTHERN PLAINS THE NEXT SEVERAL DAYS. MODELS IN FAIR AGREEMENT. UPPER LOW WILL MOVE JUST NORTH OF NORTH DAKOTA FRIDAY WITH MAINLY ZONAL UPPER PATTERN OVER THE NORTHERN PLAINS. SURFACE TROUGH ALONG THE FRONT RANGE WILL MOVE INTO WESTERN NEBRASKA FRIDAY NIGHT AND WILL BE THE FOCUS FOR ONGOING THUNDERSTORMS THROUGH THE EARLY EVENING MAINLY EAST OF HIGHWAY 83. MID LEVEL WAVE MOVING THROUGH MEAN FLOW AND LOW LEVEL JET WILL KEEP THUNDERSTORMS MOVING EAST OVER NIGHT. HAVE LEFT FORECAST DRY SATURDAY MORNING WITH INCREASING CHANCES SATURDAY AFTERNOON ALONG THE SURFACE TROUGH AND THEN WITH THE COOL FRONTAL PASSAGE OVER NIGHT WITH CHANCE POPS RETAINED. GULF OPEN SATURDAY NIGHT INTO SUNDAY AS COOLER AIR MOVES IN FROM THE NORTHWEST. VERY STRONG MID LEVEL WAVE TO MOVE ACROSS WESTERN NEBRASKA SUNDAY NIGHT AS UPPER LOW OVER SOUTH CENTRAL CANADA PUSHES SLOWLY SOUTH ACROSS THE NORTHERN PLAINS. HAVE UPPED TO LIKELY`S SUNDAY NIGHT AND INCREASED QPF. COOLER TEMPERATURES THROUGH THE FIRST PART OF THE WEEK. UPPER TROUGH WILL CONTINUE TO MOVE TO THE SOUTHEAST ACROSS THE NORTHERN PLAINS INTO IOWA AND BRING COOLER TEMPERATURES TO THE FORECAST AREA AND ON AND OFF AGAIN SHOWERS AND THUNDERSTORMS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1227 AM CDT FRI JUN 20 2014 THE RAP AND NAM MODELS SHOW A CLUSTER OF TSTMS DEVELOPING ACROSS SWRN NEB AROUND 10Z. THESE STORMS SHOULD MOVE OFF TO THE EAST 12Z- 15Z AND REMAIN SOUTH OF INTERSTATE 80. WITH CLEAR SKY AND RESIDUAL MOISTURE FROM THE HEAVY RAINS LAST NIGHT...LOCALIZED FOG IS A FORECAST CONCERN FOR CENTRAL AND SOUTHWEST NEBRASKA INCLUDING BBW...LBF AND OGA. CURRENT WIND IN THE PLATTE RIVER VALLEY IS 140-160 AT 4-6KT WHICH COULD SUPPORT A FORECAST FOR FOG AT LBF IF IT DECREASES TO 4KT OR LOWER AND ALSO NORTHWEST AND SOUTHEAST OF LBF. SURFACE DEWPOINTS UPWIND OF LBF ARE IN THE UPPER 50S. HOWEVER...THE DEPTH OF THE MOISTURE JUST OFF THE SURFACE IS LIKELY TO BE INSUFFICIENT FOR CREATING A SATURATED LAYER IN THE LOWEST 1000 FEET ABOVE THE SURFACE AND WIDESPREAD FG/BR. STILL...IN A FAIRLY NARROW BBW-LBF-OGA SWATH...VERY HEAVY RAIN FROM STORMS LAST NIGHT MAY HAVE LEFT ENOUGH STANDING SURFACE WATER TO SATURATE THE COOL NEAR-SURFACE LAYER IN PLACES AND MAY PRODUCE SPOTTY MIST OR FOG. WHEREVER MIST/FOG MAY DEVELOP...THE VISIBILITY MAY BE REDUCED TO 1SM OR LOWER. CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE BR/FG IN THE TERMINAL FORECAST FOR LBF. IN THE REST OF THE AREA...CEILING AND VISIBILITY IS LIKELY TO BE UNLIMITED. THUNDERSTORMS ARE POSSIBLE FRIDAY AFTERNOON AND EVENING SOUTH AND EAST OF AN ONL-OGA LINE. THAT LINE MARKS A CONTRAST BETWEEN MOIST UNSTABLE AIR IN THE SOUTH AND DRY AIR TO THE NORTH. HOWEVER...THE THUNDERSTORM COVERAGE IS LIKELY TO BE LIMITED TO 30 PERCENT OR LESS. THAT RESULTS IN A LOW PROBABILITY OF A THUNDERSTORM AT ANY PARTICULAR SITE. WIND ON FRIDAY IS EXPECTED TO BE 260-290 AT 12-14G21-22KT IN NORTHERN NEBRASKA BY 17Z. AIRPORTS THAT ARE LIKELY TO BE AFFECTED INCLUDE ONL...ANW...VTN...TIF AND MHN. WIND IN THE REST OF THE AREA WILL BE 170-210 AT LESS THAN 12KT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...POWER SHORT TERM...BROOKS LONG TERM...POWER AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
335 AM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 335 AM CDT FRI JUN 20 2014 PRECIP CHANCES AND STRENGTH WILL BE THE MAIN FORECAST ISSUE FOR THE SHORT TERM. UPPER LOW CURRENTLY CENTERED ALONG THE MT/CANADIAN BORDER...AND MODELS ARE IN PRETTY GOOD AGREEMENT ON TRACKING THE UPPER LOW SLOWLY EASTWARD TODAY. THERE WILL BE A STRONG VORT MAX/JET STREAK COMING INTO THE CWA BY THIS AFTERNOON. WITH THE STRONG UPPER LEVEL SYSTEM COMING THROUGH...BULK SHEAR VALUES WILL BE VERY STRONG...UP IN THE 50 TO 60 KT RANGE ACROSS PORTIONS OF THE SOUTHERN CWA. MORE IN QUESTION WILL BE THE INSTABILITY. THE NAM BRINGS CAPE VALUES OF 1500-2000 J/KG INTO OUR SOUTHEASTERN COUNTIES...AND THE RUC IS SIMILAR BUT MORE IN THE 1000-1500 RANGE. STRATUS OVER THE EAST HAS BEEN CLEARING OUT AND FOG HAS BEEN NOT VERY WIDESPREAD...SO THERE SHOULD BE AT LEAST A LITTLE BIT OF HEATING THIS AFTERNOON. HOWEVER...CLOUDS HAVE BEEN INCREASING OVER THE WESTERN COUNTIES AND REGIONAL RADAR SHOWS QUITE A BIT OF ACTIVITY OVER WESTERN ND WITH THE JET STREAK COMING OUT. THE UPPER SUPPORT MAY BE INTO THE ARE BEFORE WE CAN DESTABILIZE ENOUGH. FOR THAT REASON...BUMPED UP POPS AND WILL MENTION CHANCE OF SEVERE IN THE HWO...BUT WILL KEEP A SEVERE MENTION OUT OF THE GRIDS FOR THE TIME BEING. TONIGHT...THE MAIN UPPER LOW WILL LIFT NORTHEASTWARD INTO CANADA. A FEW SHOWERS MAY BE HANGING AROUND THE NORTHEASTERN COUNTIES EARLY ON BUT THINK THERE WILL BE A BREAK IN PRECIP FOR MUCH OF THE NIGHT. CONTINUED TO KEEP TEMPS OVERNIGHT IN THE UPPER 50S TO LOW 60S. SUNSHINE AND SOUTH TO SOUTHWESTERLY SFC WINDS SHOULD HELP HIGHS ON SATURDAY REACH THE 80S IN MANY AREAS. BY SATURDAY AFTERNOON...A WEAK SHORTWAVE PUSHING IN FROM THE WEST WILL HELP BRING A SFC TROUGH AXIS INTO CENTRAL ND AND THERE SHOULD BE SOME CONVECTIVE ACTIVITY ALONG WITH IT. BULK SHEAR VALUES ARE QUITE A BIT LOWER BUT THERE SHOULD BE DECENT INSTABILITY. WILL CONTINUE TO KEEP CHANCE POPS GOING. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM CDT FRI JUN 20 2014 SATURDAY NIGHT THROUGH SUNDAY NIGHT...MORE SHORTWAVES MOVE THROUGH AS THE ACTIVE PATTERN CONTINUES UNDER WEST TO SOUTHWESTERLY FLOW ALOFT. THE MAIN SFC TROUGH WILL MOVE OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY...WITH SOME WEAK COLD AIR ADVECTION BEHIND IT. THINK THAT BEST CHANCES FOR PRECIP WILL BE LATE SATURDAY NIGHT INTO SUNDAY AS THIS FEATURE MOVES THROUGH. KEPT 20-40 POPS GOING BEFORE TAPERING THEM OFF SUNDAY NIGHT. TEMPS ON SUNDAY WILL BE A BIT LOWER THAN SATURDAY...MAINLY IN THE 70S. MONDAY THROUGH THURSDAY...THIS PERIOD WILL BE CATEGORIZED BY MEAN ZONAL FLOW...THE UPPER LOW HAVING DEPARTED TO THE EAST. SEVERAL SHORT WAVE RIPPLES LIKELY TO MOVE THROUGH THIS FLOW...OFFERING PCPN CHANCES PERHAPS TUESDAY AND AGAIN ON THURSDAY. BELIEVE THE BEST BET FOR TOTALLY DRY WILL COME MIDWEEK...AS BOTH 00Z GFS/ECMWF DEPICT A BUBBLE OF CANADIAN HIGH PRESSURE FOR WEDNESDAY. LOOKS LIKE WARMEST DAY WILL BE MONDAY WITH COOLER READINGS UNDER MORE CLOUD COVER TUESDAY...RECOVERING TO NEAR AVERAGE FOR LATE JUNE BY WED/THUR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1146 PM CDT THU JUN 19 2014 DID NOT MENTION ANY FOG SO LATER SHIFTS WILL HAVE TO ADD IF IT APPEARS MORE LIKELY. LOOKS LIKE MID CLOUDS AND MORE SHOWERS WILL DRIFT INTO THE WESTERN FA IN THE EARLY MORNING...DRIFTING ACROSS THE NORTH THROUGH THE MID TO LATE MORNING. MAY BE MORE CONVECTION DEVELOPING BY AFTERNOON THEN CLEARING BY EVENING. && .HYDROLOGY... ISSUED AT 252 PM CDT THU JUN 19 2014 RECENT HEAVY RAINS OVER THE RED RIVER BASIN IS CAUSING RISES ON THE MAINSTEM RED RIVER AND MINNESOTA TRIBUTARIES. RAINFALL AMOUNTS RANGED FROM 2.5 INCHES AROUND THE WAHPETON/BRECKENRIDGE AREA TO AROUND A QUARTER INCH IN BELTRAMI AND LAKE OF THE WOODS COUNTIES. WITH THE RAINFALL...NEW RIVER POINT WARNINGS HAVE BEEN ISSUED RAISING ABERCROMBIE...FARGO AND OSLO TO MODERATE FLOOD STAGE. AN AREAL FLOOD WARNING HAS BEEN ISSUED UNTIL NOON SUNDAY FOR EAST CENTRAL BELTRAMI COUNTY. BELTRAMI COUNTY EMERGENCY MANAGEMENT RELAYED THAT THE TAMARAC RIVER NEAR WASKISH IS WELL OUT OF ITS BANKS. WATER IS SURROUNDING NUMEROUS HOUSES WITH A FEW ROADS WASHED OUT...AND NUMEROUS AGRICULTURAL FIELDS ARE UNDER WATER. WATER IS ALSO BEGINNING TO APPROACH THE BOTTOMS OF BRIDGES ALONG THE TAMARAC RIVER. MORE WATER IS EXPECTED TO FLOW INTO THE TAMARAC RIVER...AND THE SITUATION CONTINUES TO BE MONITORED. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...JR LONG TERM...WJB AVIATION...GODON HYDROLOGY...HOPKINS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
325 AM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 325 AM CDT FRI JUN 20 2014 PRECIP CHANCES AND STRENGTH WILL BE THE MAIN FORECAST ISSUE FOR THE SHORT TERM. UPPER LOW CURRENTLY CENTERED ALONG THE MT/CANADIAN BORDER...AND MODELS ARE IN PRETTY GOOD AGREEMENT ON TRACKING THE UPPER LOW SLOWLY EASTWARD TODAY. THERE WILL BE A STRONG VORT MAX/JET STREAK COMING INTO THE CWA BY THIS AFTERNOON. WITH THE STRONG UPPER LEVEL SYSTEM COMING THROUGH...BULK SHEAR VALUES WILL BE VERY STRONG...UP IN THE 50 TO 60 KT RANGE ACROSS PORTIONS OF THE SOUTHERN CWA. MORE IN QUESTION WILL BE THE INSTABILITY. THE NAM BRINGS CAPE VALUES OF 1500-2000 J/KG INTO OUR SOUTHEASTERN COUNTIES...AND THE RUC IS SIMILAR BUT MORE IN THE 1000-1500 RANGE. STRATUS OVER THE EAST HAS BEEN CLEARING OUT AND FOG HAS BEEN NOT VERY WIDESPREAD...SO THERE SHOULD BE AT LEAST A LITTLE BIT OF HEATING THIS AFTERNOON. HOWEVER...CLOUDS HAVE BEEN INCREASING OVER THE WESTERN COUNTIES AND REGIONAL RADAR SHOWS QUITE A BIT OF ACTIVITY OVER WESTERN ND WITH THE JET STREAK COMING OUT. THE UPPER SUPPORT MAY BE INTO THE ARE BEFORE WE CAN DESTABILIZE ENOUGH. FOR THAT REASON...BUMPED UP POPS AND WILL MENTION CHANCE OF SEVERE IN THE HWO...BUT WILL KEEP A SEVERE MENTION OUT OF THE GRIDS FOR THE TIME BEING. TONIGHT...THE MAIN UPPER LOW WILL LIFT NORTHEASTWARD INTO CANADA. A FEW SHOWERS MAY BE HANGING AROUND THE NORTHEASTERN COUNTIES EARLY ON BUT THINK THERE WILL BE A BREAK IN PRECIP FOR MUCH OF THE NIGHT. CONTINUED TO KEEP TEMPS OVERNIGHT IN THE UPPER 50S TO LOW 60S. SUNSHINE AND SOUTH TO SOUTHWESTERLY SFC WINDS SHOULD HELP HIGHS ON SATURDAY REACH THE 80S IN MANY AREAS. BY SATURDAY AFTERNOON...A WEAK SHORTWAVE PUSHING IN FROM THE WEST WILL HELP BRING A SFC TROUGH AXIS INTO CENTRAL ND AND THERE SHOULD BE SOME CONVECTIVE ACTIVITY ALONG WITH IT. BULK SHEAR VALUES ARE QUITE A BIT LOWER BUT THERE SHOULD BE DECENT INSTABILITY. WILL CONTINUE TO KEEP CHANCE POPS GOING. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM CDT FRI JUN 20 2014 SATURDAY NIGHT THROUGH SUNDAY NIGHT...MORE SHORTWAVES MOVE THROUGH AS THE ACTIVE PATTERN CONTINUES UNDER WEST TO SOUTHWESTERLY FLOW ALOFT. THE MAIN SFC TROUGH WILL MOVE OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY...WITH SOME WEAK COLD AIR ADVECTION BEHIND IT. THINK THAT BEST CHANCES FOR PRECIP WILL BE LATE SATURDAY NIGHT INTO SUNDAY AS THIS FEATURE MOVES THROUGH. KEPT 20-40 POPS GOING BEFORE TAPERING THEM OFF SUNDAY NIGHT. TEMPS ON SUNDAY WILL BE A BIT LOWER THAN SATURDAY...MAINLY IN THE 70S. MONDAY THROUGH THURSDAY...THIS PERIOD WILL BE CATEGORIZED BY MEAN ZONAL FLOW...THE UPPER LOW HAVING DEPARTED TO THE EAST. SEVERAL SHORT WAVE RIPPLES LIKELY TO MOVE THROUGH THIS FLOW...OFFERING PCPN CHANCES PERHAPS TUESDAY AND AGAIN ON THURSDAY. BELIEVE THE BEST BET FOR TOTALLY DRY WILL COME MIDWEEK...AS BOTH 00Z GFS/ECMWF DEPICT A BUBBLE OF CANADIAN HIGH PRESSURE FOR WEDNESDAY. LOOKS LIKE WARMEST DAY WILL BE MONDAY WITH COOLER READINGS UNDER MORE CLOUD COVER TUESDAY...RECOVERING TO NEAR AVERAGE FOR LATE JUNE BY WED/THUR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1146 PM CDT THU JUN 19 2014 DID NOT MENTION ANY FOG SO LATER SHIFTS WILL HAVE TO ADD IF IT APPEARS MORE LIKELY. LOOKS LIKE MID CLOUDS AND MORE SHOWERS WILL DRIFT INTO THE WESTERN FA IN THE EARLY MORNING...DRIFTING ACROSS THE NORTH THROUGH THE MID TO LATE MORNING. MAY BE MORE CONVECTION DEVELOPING BY AFTERNOON THEN CLEARING BY EVENING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...JR LONG TERM...JR/WJB AVIATION...GODON
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
145 AM EDT FRI JUN 20 2014 .SYNOPSIS... HIGH PRESSURE WILL WEAKEN AS AN UPPER RIDGE GRADUALLY BREAKS DOWN TODAY. THIS SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA OVER THE WEEKEND. TYPICAL SUMMERTIME WEATHER CONTINUES ACROSS THE REGION NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 145 AM EDT FRIDAY...SCATTERED TO BROKEN MID/HIGH DEBRIS CLOUDS FROM DECAYING UPSTREAM CONVECTION ACROSS NORTHEAST TN CONTINUE TO STREAM IN ALOFT ACROSS THE REGION. LIKEWISE...A MOIST PBL HAS ALLOWED FOR DEVELOPMENT OF LOW STRATUS IN AND AROUND THE MOUNTAINS VALLEYS...ALONG WITH AREAS OF PATCHY FOG. STILL EXPECTING THIS TO CONTINUE THROUGH THE OVERNIGHT BEFORE SUNRISE...THEN ERODE SHORTLY THEREAFTER. THUS...NO CHANGES MADE/NEEDED TO THE EXTREME NEAR TERM PORTION OF THE FORECAST. PREVIOUS DISCUSSION... EVENING UPDATE...SHOWERS ARE LEAVING THE FCST AREA TO THE SOUTH WHILE ANOTHER LINE OF WEAK CONVECTION APPROACHES THE NRN MTNS. DON/T ANTICIPATE MUCH EFFECT FROM THESE STORMS AS THEY APPROACH AND WEAKEN ON THE TN UPSLOPE SIDE. CAM MODELS ARE OVERDONE WITH THE UPPER ENERGY SUPPORT...EXCEPT FOR THE HRRR WHICH INDICATES A WEAKENING TREND...ALBEIT IN THE WRONG LOCATION. ANYWAY...CURRENT POPS HAVE THIS FEATURE IN HAND. THERE WILL BE ANOTHER AREA OF ACTIVITY APPROACHING THE NC MTNS THROUGH THE OVERNIGHT AS UPPER HEIGHTS FALL...BUT A STRONG MCS TYPE STORM IS UNLIKELY THIS FAR SOUTH. MIN TEMPS LOOK GOOD AND THERE COULD BE AREAS OF DENSE VALLEY FG OVERNIGHT. 730 PM EDT UPDATE...IMPROVING CONDS OVER THE NEXT COUPLE HRS CWFA/WIDE. A COUPLE SHORT LIVED -SHRA ARE DEVELOPING ALONG EXISTING OUTFLOW BOUNDARIES...HOWEVER DRIER AIR IS WORKING IN ALOFT AND WILL HELP DISSIPATE DEBRIS CLOUDINESS AND ANY DEEP CONV POTENTIAL THIS EVENING. MADE SOME TWEAKS TO THE T/TDS GRIDS BASED ON PREVIOUS PRECIPITATION AND LOWERED POPS TO LESS THAN SLIGHT ACROSS THE NRN ZONES. 430 PM EDT UPDATE...ONGOING CONVECTION HAS BECOME QUITE STRONG TO SEVERE WITH A FEW STORMS ACROSS THE NC MTNS AND FTHILLS. UPPER BROAD S/W IS ENHANCING DEEP CONVECTION AND ALLOWING THE STORMS ACROSS THE FTHILLS TO TAP INTO VERY HIGH VALUES OF DCAPE. THE CLT TDWR INDICATED A WIDE AREA OF VELOCITIES WITH ONE STORM ON THE ORDER OF 50+ KTS...NO DOUBT KNOCKING DOWN SEVERAL TREES AND PWR LINES. THUS...A WIND THREAT SEEMS MORE PROBABLE AS THE STORMS MOVE INTO THE PIEDMONT OF THE CAROLINAS THIS AFTERNOON. QUARTER SIZE HAIL HAS BEEN PRETTY MUCH THE LARGEST REPORTED SO FAR...EVEN WITH VERY TALL AND ROBUST STORMS. MAKES SENSE WITH THE RELATIVELY WARM MLVLS AND HIGH FREEZING LEVELS. WILL EXPECT THE BEST COVERAGE OF TSTMS OVER THE I/77 CORRIDOR THROUGH 23Z WITH STORMS ALSO DEVELOPING SOUTH OVER NE GA AND ACROSS NRN UPSTATE. AS OF 215 PM EDT...ISOLD DEEP CONVECTION HAS KICKED OFF OVER THE HIGHER MTNS...WITH CELLS LINED UP UPSTREAM ACRS THE GREAT TENN VALLEY AS WELL...UNDER A WEAK SHORTWAVE ROUNDING THE RIDGE OVER THE SERN STATES. ACTIVITY ALONG THE OLD OUTFLOW BDY ACRS FAR ERN KY AND SRN WV STILL SAGGING SOUTH. LATEST MESO MODELS SHOW BOTH OF THESE LINEAR FEATURES MOVING TOWARD OUR CWFA THRU THE REST OF THE AFTN. INFLOW WINDS ARE WEAK...BUT INSTABILITY AHEAD OF THE LINES IS STRONG AS ONE MIGHT EXPECT. IT LOOKS LIKE THE MESO GUIDANCE IS SUGGESTING MORE OF A PROPAGATION INTO OUR AREA AND SUBSEQUENT REDEVELOPMENT ALONG REMNANT BOUNDARIES. NONETHELESS...HIGHEST POPS REMAIN OVER THE MTNS WITH A LATER INCREASE IN POPS OVER THE PIEDMONT AS ROUNDS OF STORMS FORM ACRS THE AREA. TONIGHT...MOST OF THE ENERGY WITH THE AFOREMENTIONED SHORTWAVE MOVES OFF THE MID-ATLANTIC COAST BUT SOME WEAK DPVA MAY TRAIL IT...MOVING SEWD ACRS THE CWFA THIS EVENING. A MINOR LLVL BOUNDARY IS SHOWN TO MOVE SWD IN THE WAKE OF THE WAVE AS HIGH PRESSURE BUILDS SLIGHTLY S AND E OUT OF THE GREAT LAKES AREA. SOME LINGERING MUCAPE IS SHOWN THOUGH IT DIMINISHES AND IS INHIBITED AND WELL ELEVATED ANYWAY. IT APPEARS MOST LIKELY THAT ANY REMAINING CONVECTION ALONG BOUNDARIES IN OR INVOF THE FA WILL DIMINISH EXCEPT PERHAPS IN THE MTNS. LOWS WILL BE NEAR NORMAL. FRIDAY...FLOW ACRS THE SRN CONUS GENERALLY BECOMES MORE ZONAL. NORTHERLY FLOW PERSISTS WITH LOW PRS OFF THE ATLANTIC COAST AND SOME SEMBLANCE OF THE BOUNDARY REMAINING IN THE AREA...THOUGH ONLY PROVIDING VERY WEAK CONVERGENCE. OVERALL...THE FA REMAINS UNDER WEAKLY SHEARED BUT SEASONABLY HOT AND UNSTABLE CONDITIONS. LAPSE RATES ARE SHOWN TO BE A LITTLE WEAKER THAN THOSE SEEN TODAY...WITH LOWER CAPE VALUES DURING PEAK HEATING. VALUES HOWEVER REMAIN HIGH ENOUGH TO EXPECT A SMALL SEVERE THREAT...FROM DOWNBURST WIND AND HAIL. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... AS OF 145 PM THURSDAY...CHANGES TO THE OVERALL PATTERN WILL BE TYPICALLY SUBTLE DURING THE SHORT TERM PERIOD...AND ARE UNLIKELY TO HAVE A GREAT DEAL OF IMPACT ON THE SENSIBLE WEATHER. THE UPPER RIDGE IS FORECAST TO SLOWLY RETROGRADE TOWARD THE SOUTH CENTRAL CONUS AND WEAKEN DURING THE PERIOD...PLACING THE SOUTHEAST AND MID-ATLANTIC ALONG THE SOUTHERN PERIPHERY OF THE WESTERLIES...WITH A DEEP NW FLOW ANTICIPATED ACROSS OUR AREA. WHILE THIS WILL THEORETICALLY RENDER THE AREA MORE SUSCEPTIBLE TO ORGANIZED CONVECTION MOVING OUT OF THE OHIO VALLEY REGION...BASED UPON WIND PROFILES...IT IS DOUBTFUL THAT ANYTHING TOO ORGANIZED AND SELF-SUSTAINING WILL BE ABLE TO DEVELOP UPSTREAM...AS ONE MAY NEED TO TRAVEL AS FAR NORTH AS THE CANADIAN BORDER TO FIND ROBUST SHEAR. NEVERTHELESS...WITH A WEAK COLD FRONT APPROACHING THE REGION...AND HALFWAY DECENT STEERING CURRENTS (MEAN CLOUD BEARING WINDS ON THE ORDER OF 15-20 KTS...ABOVE CLIMO POPS (GENERALLY 30-40 PERCENT DURING THE AFTERNOON/EVENING...20/30 PERCENT DURING THE EARLY MORNING HOURS) APPEAR WARRANTED THROUGH THE PERIOD. THE WEAK COLD FRONT MAY BACK DOOR ITS WAY THROUGH THE AREA BY THE END OF THE WEEKEND...POSSIBLY KNOCKING TEMPS DOWN TO NEAR...OR SLIGHTLY BELOW CLIMO ACROSS THE NC PIEDMONT...IN ADDITION TO PROVIDING A FOCUS FOR INITIATION OF AFTERNOON/EVENING SHOWERS AND STORMS. OVERALL...TYPICAL EARLY SUMMER WEATHER APPEARS IN STORE THIS WEEKEND...WITH PERHAPS SLIGHTLY HIGHER COVERAGE OF CONVECTION THAN IS TYPICAL. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 1245 PM THURSDAY...NO BIG CHANGES WERE MADE TO THE FCST IN THE MEDIUM RANGE. THE UPPER PATTERN WILL BE PROGRESSIVE...WITH RELATIVELY FLAT FLOW ACRS THE ERN CONUS. THE WESTERLIES/POLAR JET WILL STAY WELL NORTH OF THE CWFA. SO EXPECT PRIMARILY DIURNALLY-DRIVEN CONVECTION EVERY DAY THRU LATE NEXT WEEK. THE OPERATIONAL GFS AND ECWMF DIVERGE QUITE A BIT BY MIDWEEK...WITH THE GFS EARLIER AND DEEPER WITH A LONGWAVE TROF ACRS THE MIDWEST TO THE GREAT LAKES. THE ECMWF KEEPS STRONGER RIDGING ALONG THE EAST COAST. THE GFE/ECMWF ENSEMBLE MEANS WERE A COMPROMISE AND PREFERRED BY WPC. THIS KEEPS ANY SIGNIFICANT/SYNOPTIC FRONTAL BOUNDARIES TO OUR NORTH AND WEST THRU THURSDAY. I BLENDED THE WPC/CONS/BCCONSALL WITH OFFICIAL...WHICH RESULTS IN ONLY SMALL CHANGES. BEST COVERAGE OF CONVECTION WILL BE ACRS THE MTNS EACH DAY. TEMPS WILL CONTINUE TO BE SLIGHTLY ABOVE NORMAL THRU THE MEDIUM RANGE. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH THE EXCEPTION OF MVFR VISB RESTRICITONS DUE TO POSSIBLE AFTERNOON TSRA. SCT/BKN HIGH LEVEL DEBRIS CLOUDS WILL PERSIST THROUGH THE OVERNIGHT BEFORE GIVING WAY TO SCT LOW VFR CU BY LATE MORNING AS HEATING BUILDS AND LAPSE RATES STEEPEN IN THE PBL. EXPECTING A BKN CU FIELD TO DEVELOP ACROSS THE PIEDMONT IN THE AFTERNOON HOURS OF PEAK HEATING...ALONG WITH INCREASING INSTABILITY AND TSRA POTENTIAL. KEPT PREVIOUS PROB30 GROUP FOR MVFR 4SM TSRA FROM 20-24Z TO ACCOUNT. WINDS THROUGH THE PERIOD WILL REMAIN WEST NORTHWESTERLY AND IN THE 5-8KTS RANGE BEFORE CALMING THIS EVENING. ELSEWHERE...VFR CONDITIONS WILL PREVAIL THROUGH THE OVERNIGHT AT ALL SITES WITH THE EXCEPTION OF KAVL AND KHKY WHERE FOG RESTRICITIONS ARE LIKELY. ALREADY SEEN IFR CONDITIONS AT KAVL WITH SOME RECOVERY AT THE PRESENT TIME. EXPECTING CONDITIONS TO DETERIORATE ONCE AGAIN AS THE MOIST PBL DECOUPLES. ALSO EXPECTING RESTRICTIONS AT KHKY THUS INCLUDED TEMPO FOR MVFR FOG...AND PREVAILED MVFR FOG WITH AN IFR TEMPO DUE TO VISB/CIGS AT KAVL. OTHERWISE...MID/HIGH DEBRIS CLOUDS WILL PREVAIL INTO MID MORNING BEFORE ALL SITES EXPERIENCE DEVELOPING CU THROUGH THE HEATING OF THE DAY. KEPT PREVIOUS PROB30 MENTIONS AT ALL SITES FOR POSSIBLE AFTERNOON TSRA AND MVFR RESTRICTIONS. WINDS THROUGH THE PERIOD WILL REMAIN WEST NORTHWESTERLY AND IN THE 5-8KTS RANGE THROUGH THE AFTERNOON MIXING HOURS. OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED INTO THE WEEKEND...WITH THE GREATEST COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF RECENT RAINFALL. CONFIDENCE TABLE... 05-11Z 11-17Z 17-23Z 23-05Z KCLT HIGH 100% HIGH 100% HIGH 100% LOW 45% KGSP HIGH 100% HIGH 100% HIGH 100% LOW 45% KAVL HIGH 98% HIGH 98% HIGH 100% LOW 45% KHKY HIGH 100% HIGH 95% HIGH 100% LOW 45% KGMU HIGH 100% HIGH 100% HIGH 100% LOW 45% KAND HIGH 100% HIGH 91% HIGH 100% LOW 45% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...ARK NEAR TERM...CDG/SBK/WIMBERLEY SHORT TERM...JDL LONG TERM...ARK AVIATION...CDG
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1258 AM CDT FRI JUN 20 2014 .UPDATE... 06Z UPDATED AVIATION DISCUSSION BELOW. && .SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT TIGHT VORTICITY MAXIMA ROTATING OVER WESTERN SD AT THIS TIME HAS PRODUCED THUNDERSTORMS...WHICH WAS WHAT THE HRRR MODEL WAS INDICATING MOST OF THE DAY. SOME OF THESE STORMS HAVE BECOME SEVERE WITH HAIL AND EVEN REPORTS OF FUNNEL CLOUDS/LANDSPOUTS. NOT SURPRISING GIVEN COOLER TEMPS ALOFT AND TIGHT ROTATION OF VORT SPINNING ACROSS. MLCAPE VALUES GENERALLY RANGE FROM 500 TO 1000 J/KG WITH DEEP LAYER SHEAR 20 TO 30 KNOTS OVER WESTERN SD. ALTHOUGH...BETTER SHEAR VALUES EXIST OVER CENTRAL SD. HI RES MODELS SHOW SOME OF THIS ACTIVITY SPREADING ACROSS THE CWA AS LONG AS THE SUN IS UP. HAVE INCLUDED POPS THIS EVENING TO ACCOUNT FOR THIS. CONDITIONS QUIET DOWN LATE TONIGHT THROUGH FRIDAY NIGHT AS UPPER LEVEL FLOW BECOMES ZONAL. GIVEN 850 MB TEMPS ON FRIDAY...EXPECT HIGHS TO BE RATHER WARM WITH READINGS IN THE 80S. MORE ACTIVE WEATHER RETURNS TO THE AREA SATURDAY AND SATURDAY NIGHT. INSTABILITY INCREASES TO 2000 TO 3000 J/KG WITH 40 TO 50 KNOTS OF DEEP LAYER SHEAR. LOW LEVEL SHEAR NOT ALL TOO IMPRESSIVE. COULD BE SEEING SOME SEVERE STORMS ACROSS THE AREA SATURDAY INTO SATURDAY EVENING. .LONG TERM...SUNDAY THROUGH THURSDAY THE PERIOD STARTS OFF WITH FAIRLY FAST MOVING UPPER LEVEL FLOW WITH A SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE CENTRAL PLAINS EARLY IN THE PERIOD...PUTTING THE CWA IN A POTENTIAL SPOT FOR SHOWER AND THUNDERSTORM ACTIVITY SUNDAY THROUGH EARLY TUESDAY. HIGH PRESSURE DROPPING OVER THE NORTHERN PLAINS WILL KEEP THINGS DRY TUESDAY NIGHT AND WEDNESDAY...THEN MAY SEE ANOTHER CHANCE OF PRECIPITATION WEDNESDAY NIGHT AND THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES THE REGION. NEAR NORMAL TEMPERATURES WILL BE THE RULE THROUGH THE PERIOD...WITH HIGHS IN THE MID 70S TO LOWER 80S AND OVERNIGHT LOWS IN THE MID TO UPPER 50S. && .AVIATION... 06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS MAINLY VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY EVENING FOR ALL TERMINAL LOCATIONS. WITH LIGHT WINDS AND MOSTLY CLEAR SKIES AND LOW DEW POINT SPREADS...EXPECT SOME FOG TO FORM TONIGHT AT ABR AND ATY AND POSSIBLY AT MBG AND PIR. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...MOHR SHORT TERM...TMT LONG TERM...PARKIN AVIATION...MOHR WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
330 AM CDT FRI JUN 20 2014 .SHORT TERM... (Today and tonight) Showers, and a few thunderstorms, continue to drift to the north and northwest across the southern half of the CWA early this morning. This convection is the result of the enhanced lift associated with an MCV that has developed near Del Rio and persistent warm, moist inflow from a 30 kt low-level jet. The latest runs of the HRRR and the TTU WRF have caught on and continue this precipitation across the southwest quadrant of the CWA well into the morning hours before diminishing in areal coverage by midday. Rainfall totals have generally remain on the light side, but a few areas have seen amounts approaching 1". The RAWS station 10 miles south of Barnhart measured 0.91" in the past 2 hours. Additional showers and thunderstorms will be possible this afternoon, generally south of a Sterling City to San Saba line, however, coverage should be limited. The NAM and RAP point soundings indicate an uncapped environment and any residual outflow boundaries from this morning`s activity may help initiate diurnal storms. That said, we`ve had a very weak cap (at best) the past several days and diurnal convection has been . Thus, only isolated thunderstorms were mentioned for this afternoon. The increase in cloud cover and precipitation in the area will result in max temps a few degrees cooler than what we saw yesterday. Highs this afternoon should range from the mid 80s in the southwest to the lower 90s in the Big Country. We may again see nocturnal convection across the southwest portion of the CWA. The slight chance for precipitation was expanded slightly north and east to account for this potential. Overnight low temperatures will be near 70 degrees. Johnson .LONG TERM... (Saturday through Thursday) This weekend an upper high over southeastern Texas will begin to weaken as an upper ridge builds into the area from the west. The forecast area will thus continue to be under a weak mid/upper level shear axis through Saturday with a chance of isolated thunderstorms developing over the western CWA during the day on Saturday and over the southern CWA Saturday night. As the western ridge continues to build over the area on Sunday the forecast area will come under a northwest flow aloft. Afternoon temperatures will warm from the upper 80s and lower 90s on Saturday to the lower to mid 90s on Sunday and a still little warmer on Monday. As an upper short wave moves east through the Central Plains on Tuesday it will push a weak cold into the northern Big Country by Tuesday morning. The frontal boundary will then stall but will provide a focus for the development of showers and thunderstorms over the Big Country beginning Monday night and through Tuesday night as periodic disturbances move southeast in the upper flow aloft. As the upper ridge continues to build over the western CONUS through midweek and eventually over the central CONUS by the end of the week, our forecast will be dry with afternoon highs generally in the mid to upper 90s and morning lows in the lower 70s. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 89 71 90 71 93 / 10 10 10 10 10 San Angelo 88 70 91 71 94 / 20 20 20 10 10 Junction 86 69 90 70 92 / 30 20 10 20 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
312 AM CDT FRI JUN 20 2014 .DISCUSSION... UPPER LOW HAS MOVED TO SOUTHEASTERN MANITOBA...AND SHOULD START PINWHEELING NORTH DURING THE DAY. RIDGE IS CENTERED OVER SOUTHERN MISSISSIPPI VALLEY AND WILL SLOWLY SLIDE SOUTHWEST OVER NEXT COUPLE OF DAYS. PWATS ARE ON THE WAY DOWN...FROM NEAR 2 INCHES YESTERDAY TO ABOUT AN INCH AND A HALF TODAY. GUIDANCE IS STRUGGLING WITH THE FEATURES THAT WILL DEFINE TODAY/S WEATHER...FROM THE CURRENT CONVECTION IN SOUTHERN OKLAHOMA TO SEA BREEZE TYPE SHOWERS MOVING IN FROM THE COAST. AS I WRITE THIS...THE OKLAHOMA CONVECTION IS WEAKENING AND MAY BE GONE BY 7 AM...BUT WILL KEEP A SMALL AREA OF ISOLATED THUNDER NEAR THE RED RIVER THIS MORNING. HAVE ALSO ADDED ISOLATED THUNDER FOR THIS AFTERNOON IN SOUTH AND SOUTHEAST ZONES AS HRRR AND WRF ARW BOTH HINT AT SOME SEA BREEZE CONVECTION MAKING IT THAT FAR NORTH. ATMOSPHERE WILL CONTINUE TO DRY AND HAVE LEFT SATURDAY AND SUNDAY PRECIP FREE AS THE HIGH BUILDS CLOSER TO NORTH TX. BY MONDAY...WITH HIGH LOCATED IN MEXICO...A SERIES OF TROUGHS WILL MOVE ACROSS THE SOUTHERN PLAINS AND HAVE THUS CONTINUED WITH THE LOW POP CHANCES IN THE NORTH MONDAY AND TUESDAY...AND AREA WIDE WEDNESDAY THROUGH SATURDAY MORNING. OF INTEREST IN THE EXTENDED...BY WEDNESDAY THE ECMWF BUILDS AN UPPER TROUGH ORIENTED NORTH/SOUTH ACROSS TEXAS AND KEEPS IT IN PLACE THROUGH 240 HOURS. IF THIS STATIONARY TROUGH WOULD MATERIALIZE (THE GFS BUILDS IN A RIDGE WEST AND PUSHES THE TROUGH EAST) IT WOULD GIVE US PERIODS OF MUCH NEEDED PRECIP OVER A NUMBER OF DAYS. ECMWF PUSHES PWATS ABOVE 2 INCHES AT DFW WEDNESDAY AFTERNOON...BUT THE GFS LOOKS MUCH DRIER. ONE ANALOG THAT COMES TO MIND WOULD BE THE WIDESPREAD RAIN/FLOODING THAT OCCURRED IN JUNE 2007 WITH A SIMILAR TROUGH. AGAIN...THERE IS NO CONSENSUS ON THIS OCCURRING SO WE CAN ONLY LOOK FOR MORE AGREEMENT IN FUTURE GUIDANCE 84. && .AVIATION... /ISSUED 1142 PM CDT THU JUN 19 2014/ /6Z TAFS/ VFR CONDITIONS PREVAIL AREA WIDE LATE THIS EVENING WITH SOME SCT/BKN HIGH CLOUD SPREADING IN ACROSS THE REGION. SCATTERED SHOWERS AND THUNDERSTORMS ARE ONGOING ACROSS PARTS OF SOUTH CENTRAL OKLAHOMA AND ARE MOVING TOWARD THE RED RIVER. REGIONAL RADAR IMAGERY SHOWS A SUBSTANTIAL OUTFLOW BOUNDARY ALREADY PUSHING OUT AHEAD OF THESE STORMS...SO THINKING IS THEY WILL CONTINUE TO WEAKEN AS THEY MOVE INTO NORTH TEXAS. FOR NOW...WILL LEAVE ANY PRECIP OUT OF THE METROPLEX TAFS. OTHERWISE...SOME SCT LOW CLOUDS MAY MOVE INTO THE AREA EARLY FRIDAY MORNING WITH TEMPO MVFR CIGS AT WACO. DUNN && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 94 75 94 75 93 / 10 10 10 5 10 WACO, TX 91 72 93 73 92 / 10 5 10 5 10 PARIS, TX 92 72 92 72 91 / 10 10 10 5 10 DENTON, TX 93 73 93 74 93 / 10 10 10 5 10 MCKINNEY, TX 93 73 94 73 92 / 10 10 10 5 10 DALLAS, TX 93 76 94 75 93 / 10 5 10 5 10 TERRELL, TX 95 73 96 73 92 / 10 5 10 5 10 CORSICANA, TX 91 73 92 73 91 / 10 5 10 5 10 TEMPLE, TX 90 72 92 72 91 / 10 5 10 5 10 MINERAL WELLS, TX 91 72 92 73 92 / 10 5 10 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1140 PM CDT Thu Jun 19 2014 .AVIATION... /06Z TAFS/ Scattered showers are developing northward into the northern Edwards Plateau late this evening, approaching the southern terminals of Sonora, Junction, and Brady (KSOA/KJCT/KBBD). Its still pretty spotty and light so far, with the bulk of the more concentrated heavier rainfall likely to remain south of the area. To the north, additional storms are moving across the South Plains and may approach Abilene (KABI), but the majority looks to remain north. Which means for the most part, we are dealing with the arrival the same MVFR cigs we have seen the last few nights and their departure around mid to late morning. Convection will effect timing, but exactly how is a question. Will start with roughly the same timing as have been using and see how it works. && .PREV DISCUSSION... /ISSUED 1106 PM CDT THU JUN 19 2014/ UPDATE... Increased rainfall chances across southwest sections overnight. DISCUSSION... Shower activity is beginning to increase in coverage south of I-10 across Val Verde and Edwards counties, with a few showers also developing in southern Sutton county. A persistent area of very heavy rainfall has been ongoing this evening southeast of Del Rio. This activity is in association with a remnant MCV that is drifting slowly northwest. Latest model data, including the HRRR and Texas Tech WRF expand convection northwest across the North Edwards Plateau overnight in conjunction with the northwest propagating MCV and a strengthening 850 mb low level jet. Precipitable waters are running around 1.7 inches and will contribute to heavy rainfall potential across the said area. Ramped up POPs to likely across Crockett, Sutton and southwest Schleicher county overnight and will continue to mention locally heavy rainfall across this area. Current thinking is that the best Flash Flood threat will be farther south across the Edwards Plateau where current convective complex will be very slow moving overnight. Will continue to monitor convective trends through the night. Another area of convection is moving east/southeast across the Texas South Plains east of Lubbock. This activity will make a run at northwest counties after midnight but outflow is currently outrunning the convection and will likely result in some weakening as it continues southeast. Have increases POPs to 30 percent across the northwestern Big Country to account for this uncertainty. Also tweaked temperatures and dewpoints to account for trends. PREV DISCUSSION... /ISSUED 621 PM CDT THU JUN 19 2014/ AVIATION... /00Z TAFS/ Messy forecast across the West Central Texas terminals over the next 24 hours, with a great deal of uncertainty. Weak system pushing northward up the Rio Grande may allow storms to redevelop and become more widespread across much of the area by around might and continue into the early morning hours. But not certain they will develop at all. To the west, a complex of storms will likely develop across the Panhandle and South Plains and push east this evening. But whether they reach Abilene, KABI, remains a huge question as well. For right now, will base the forecast on persistence from the last 24 to 48 hours, and add a VCTS mention to the forecast for the southernmost sites of Sonora/Junction/Brady where the storms seem most likely overnight. PREV DISCUSSION... /ISSUED 409 PM CDT THU JUN 19 2014/ SHORT TERM... (Tonight and Friday) Have a developing concern for heavy rainfall potential across our southern and possibly some central counties tonight. This is in association with a compact MCV, which appears on satellite imagery near Eagle Pass along the Rio Grande. This feature will move north-northwest and should enter our far southern counties (Sutton or Crockett Counties) toward Midnight. Low-level jet developing tonight will aid in low-level moisture transport. The Satellite Precipitation Estimates product from the NESDIS Satellite Analysis Branch has more details on the potential for locally heavy rain with this feature. Have increased PoPs across much of the southern half of our area, with a mention of locally heavy rainfall. The HRRR and TTU WRF both show development of convection across our soutern and some of our central counties tonight. PoPs may need to be raised further as radar trends become more apparent. To the northwest of our area, a gravity wave entering northwestern Texas ahead of a cold front could initiate thunderstorms late this afternoon and evening. The HRRR and TTU WRF models show a band of convection approaching our northwestern counties after 9 PM. With uncertainty in how much shower/thunderstorm coverage will occur away from the MCV, carrying lower PoPs across the rest of our area tonight. For Friday, carring low PoPs across West Central Texas. Models show a mid/upper level shear axis over our area, with precipitable water values between 1 and 1.6 inches. Little change in the temperature regime is expected. LONG TERM... (Friday night through next Thursday) Our area will remain under a weak mid/upper level shear axis through Saturday, as upper ridge begins to build over northwest Mexico into the Desert Southwest, and the upper high weakens over the lower Mississippi Valley. Have a slight chance PoP lingering across our western counties on Saturday. During the first half of next week, the upper high is progged to build over northwestern Mexico and the southwestern U.S., and weak northwest flow aloft will develop over our area. The forecast 850 mb temperatures indicate a gradual warming trend with daytime temperatures for our area. Weak surface cold front is progged to sag south of the Red River and stall Tuesday evening, The 12Z GFS suggests potential for convective complext to approach our area from the northwest Tuesday night. Did not make changes to our PoPs next week, but will monitor model trends. && .PRELIMINARY POINT TEMPS/POPS... Abilene 71 90 72 91 72 / 20 20 5 10 10 San Angelo 71 91 72 92 72 / 30 20 10 10 10 Junction 72 90 71 91 71 / 40 20 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1106 PM CDT THU JUN 19 2014 .UPDATE... Increased rainfall chances across southwest sections overnight. && .DISCUSSION... Shower activity is beginning to increase in coverage south of I-10 across Val Verde and Edwards counties, with a few showers also developing in southern Sutton county. A persistent area of very heavy rainfall has been ongoing this evening southeast of Del Rio. This activity is in association with a remnant MCV that is drifting slowly northwest. Latest model data, including the HRRR and Texas Tech WRF expand convection northwest across the North Edwards Plateau overnight in conjunction with the northwest propagating MCV and a strengthening 850 mb low level jet. Precipitable waters are running around 1.7 inches and will contribute to heavy rainfall potential across the said area. Ramped up POPs to likely across Crockett, Sutton and southwest Schleicher county overnight and will continue to mention locally heavy rainfall across this area. Current thinking is that the best Flash Flood threat will be farther south across the Edwards Plateau where current convective complex will be very slow moving overnight. Will continue to monitor convective trends through the night. Another area of convection is moving east/southeast across the Texas South Plains east of Lubbock. This activity will make a run at northwest counties after midnight but outflow is currently outrunning the convection and will likely result in some weakening as it continues southeast. Have increases POPs to 30 percent across the northwestern Big Country to account for this uncertainty. Also tweaked temperatures and dewpoints to account for trends. && .PREV DISCUSSION... /ISSUED 621 PM CDT THU JUN 19 2014/ AVIATION... /00Z TAFS/ Messy forecast across the West Central Texas terminals over the next 24 hours, with a great deal of uncertainty. Weak system pushing northward up the Rio Grande may allow storms to redevelop and become more widespread across much of the area by around might and continue into the early morning hours. But not certain they will develop at all. To the west, a complex of storms will likely develop across the Panhandle and South Plains and push east this evening. But whether they reach Abilene, KABI, remains a huge question as well. For right now, will base the forecast on persistence from the last 24 to 48 hours, and add a VCTS mention to the forecast for the southernmost sites of Sonora/Junction/Brady where the storms seem most likely overnight. PREV DISCUSSION... /ISSUED 409 PM CDT THU JUN 19 2014/ SHORT TERM... (Tonight and Friday) Have a developing concern for heavy rainfall potential across our southern and possibly some central counties tonight. This is in association with a compact MCV, which appears on satellite imagery near Eagle Pass along the Rio Grande. This feature will move north-northwest and should enter our far southern counties (Sutton or Crockett Counties) toward Midnight. Low-level jet developing tonight will aid in low-level moisture transport. The Satellite Precipitation Estimates product from the NESDIS Satellite Analysis Branch has more details on the potential for locally heavy rain with this feature. Have increased PoPs across much of the southern half of our area, with a mention of locally heavy rainfall. The HRRR and TTU WRF both show development of convection across our soutern and some of our central counties tonight. PoPs may need to be raised further as radar trends become more apparent. To the northwest of our area, a gravity wave entering northwestern Texas ahead of a cold front could initiate thunderstorms late this afternoon and evening. The HRRR and TTU WRF models show a band of convection approaching our northwestern counties after 9 PM. With uncertainty in how much shower/thunderstorm coverage will occur away from the MCV, carrying lower PoPs across the rest of our area tonight. For Friday, carring low PoPs across West Central Texas. Models show a mid/upper level shear axis over our area, with precipitable water values between 1 and 1.6 inches. Little change in the temperature regime is expected. LONG TERM... (Friday night through next Thursday) Our area will remain under a weak mid/upper level shear axis through Saturday, as upper ridge begins to build over northwest Mexico into the Desert Southwest, and the upper high weakens over the lower Mississippi Valley. Have a slight chance PoP lingering across our western counties on Saturday. During the first half of next week, the upper high is progged to build over northwestern Mexico and the southwestern U.S., and weak northwest flow aloft will develop over our area. The forecast 850 mb temperatures indicate a gradual warming trend with daytime temperatures for our area. Weak surface cold front is progged to sag south of the Red River and stall Tuesday evening, The 12Z GFS suggests potential for convective complext to approach our area from the northwest Tuesday night. Did not make changes to our PoPs next week, but will monitor model trends. && .PRELIMINARY POINT TEMPS/POPS... Abilene 71 90 72 91 72 / 20 20 5 10 10 San Angelo 71 91 72 92 72 / 30 20 10 10 10 Junction 72 90 71 91 71 / 40 20 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 24
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
421 AM EDT FRI JUN 20 2014 .SYNOPSIS... A WARM FRONT TRAILED FROM MINNESOTA TO KENTUCKY THIS MORNING. THIS FRONT WILL LIFT NORTHEAST INTO THE AREA TODAY. LOW PRESSURE WILL MOVE ALONG THIS FRONT...THROUGH THE OHIO VALLEY TONIGHT...THEN INTO VIRGINIA ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT FRIDAY... WARM FRONT...MAINLY INDICATED AROUND 850 MB...ACROSS THE OHIO VALLEY WILL BRING SOME WARM AIR ADVECTION AND KEEP DEEPER MOISTURE IN THE AREA TODAY. AGAIN EXPECTING SCATTERED THUNDERSTORMS THIS AFTERNOON. SIMILAR TO THURSDAY...HIGH CLOUDS WILL CUT BACK ON HEATING IN THE MORNING AND THEREFORE THE AMOUNT OF INSTABILITY IN THE AFTERNOON. STILL ENOUGH CAPE...FORECAST TO BE AROUND 1500 J/KG...FOR A THREAT OF STRONGER THUNDERSTORMS BEFORE 00Z/8PM. HRRR BRINGS PRECIPITATION IN TO THE FORECAST AROUND 17Z/1PM. MODELS HAVE BEEN TRENDED COOLER WITH MAXIMUM TEMPERATURES FOR TODAY. HIGH WILL DEPEND ON HOW MUCH HIGH CLOUDS FROM THIS MORNING CAN ERODE BEFORE THUNDERSTORMS DEVELOP. SHORT WAVE OVER ILLINOIS AND INDIANA WILL MOVE SOUTHEAST...REACHING WESTERN PARTS OF THE FORECAST AREA JUST AFTER 00Z AND SLOWLY MOVING ACROSS THE COUNTY WARNING AREA OVERNIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION TONIGHT WITH HIGHEST PROBABILITY AFTER MIDNIGHT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... AS OF 320 AM EDT FRIDAY... LOW PRESSURE WILL TRACK SOUTHEAST FROM NORTHERN WEST VIRGINIA SATURDAY MORNING AND REACHES EASTERN VIRGINIA BY SATURDAY AFTERNOON. THE NAM...GFS AND ECMWF SUPPORT GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS SATURDAY AS DISTURBANCE TRACKS EASTWARD ALONG THE THETA-E BOUNDARY. INCREASED POPS FOR SATURDAY ESPECIALLY SATURDAY MORNING. SPC SWODY2 HAS PLACED THE SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL PLAINS WITH A SEE TEXT IN EASTERN CAROLINAS. WITH ADDITIONAL CLOUD COVER AND PRECIPITATION SATURDAY...LOWERED HIGH TEMPERATURES WITH READINGS FROM THE UPPER 70S IN THE MOUNTAINS TO UPPER 80S IN THE PIEDMONT. AFTER THE DISTURBANCE EXITS THE AREA SATURDAY EVENING...A SLIGHT COOLER AND DRY AIRMASS WILL TEMPORARY BUILD OVER THE REGION SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL RANGE FROM AROUND 60 DEGREES IN THE WEST TO THE MID 60S IN THE EAST. SFC HIGH PRESSURE PROGGED TO BE CENTERED EAST SOUTHEAST OF NEW ENGLAND ON SUNDAY...AND SLOWLY BUILDS SOUTHWARD. DECREASED POPS FOR SUNDAY AS A NORTHERLY FLOW AND LESS INSTABILITIES SHOULD LEAD TO LESS CONVECTION. WITH CAUTION...HELD ON TO SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE GFS WAS MORE ROBUST WITH CONVECTION COMPARED TO ECMWF AND NAM FOR SUNDAY. WENT WITH HIGH TEMPERATURES SUNDAY FROM THE UPPER 70S IN THE MOUNTAINS TO THE MID 80S IN THE PIEDMONT. SOUTHEASTERLY FLOW OVERNIGHT SUNDAY MAY KEEP A FEW SHOWERS ONGOING INTO EARLY MONDAY MORNING. THE BEST CHANCE FOR SHOWERS SUNDAY NIGHT WILL OCCUR ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS. LOWS SUNDAY NIGHT WILL GENERALLY BE IN THE 60S. LEANED TOWARDS HPCGUIDE FOR MONDAY WITH PULSE STORM AND THE PRIMARY FOCUS FOR CONVECTION ACROSS THE MOUNTAINS. TAPER OFF SCATTERED STORMS TO ISOLATED SHOWERS MONDAY NIGHT. && .LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... TUESDAY COULD BE A MIX OF CONVECTION FROM PULSE STORMS IN THE EARLY AFTERNOON TRANSITIONING TO PREFRONTAL CONVECTION IN THE EARLY EVENING THROUGH THE EARLY MORNING HOURS. ON WEDNESDAY...A COLD FRONT WILL SLIDE ACROSS THE REGION WITH THE BEST AREAL COVERAGE OF THE STRONGER STORMS BEING ACROSS THE PIEDMONT. THE COLD FRONT MAY WASHOUT OR STALL WITH THE DEW POINT FRONT HANGING BACK ACROSS THE OHIO VALLEY. UNDER HEATING...SCATTERED CONVECTION MAY FIRE AGAIN ACROSS THE AREA THURSDAY ESPECIALLY ALONG AND SOUTH OF THE VA/NC BORDER. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... AS OF 145 AM EDT FRIDAY... OBSERVATIONS ACROSS THE REGION SHOWED LITTLE TO NO IFR CLOUDS...EXCEPT FOR KBLF. LOW CONFIDENCE AS TO HOW EXTENSIVE IFR CLOUDS MAY BE BEFORE 12Z THIS MORNING. BETTER CHANCE OF LOW CLOUDS MAY BE ALONG A WEAK ZONE OF CONVERGENCE FROM SOUTHERN WEST VIRGINIA INTO SOUTHEAST VIRGINIA. HIGH CLOUDS OVER THE AREA MAY ALSO LIMIT FOG DEVELOPMENT EARLY THIS MORNING. LATEST GUIDANCE INDICATES THAT INSTABILITY MAY BE MUCH LESS INTO THIS AFTERNOON. CONVECTION LIKELY FAR WEST BUT SHOWERS AND THUNDERSTORMS MAY NOT REACH EAST OF THE BLUE RIDGE UNTIL LATE IN THE EAST. EXTENDED AVIATION DISCUSSION... A WEAK FLOW PATTERN HOLDING OVER THE WEEKEND WILL KEEP THE STORM CHANCES EACH AFTERNOON THROUGH EARLY EVENING SAT/SUN BUT COVERAGE FOR NOW LOOKS A BIT LESS EACH DAY BEHIND THE PASSING IMPULSE FROM FRIDAY NIGHT. DEEPER MOISTURE LOOKS TO RETURN NORTH BY EARLY NEXT WEEK WITH BETTER COVERAGE OF AFTERNOON/EVENING STORMS ON MONDAY. AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING... PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE AFTERNOON CONVECTION REDEVELOPS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...RCS AVIATION...AMS/PM Area Forecast Discussion National Weather Service Spokane WA 252 AM PDT FRI JUN 20 2014 .SYNOPSIS... Warmer, drier, and more summer-like conditions will develop over the entire Inland Northwest this weekend into next week. Monday and Tuesday will likely be the warmest days early next week with afternoon temperatures in the mid 80s to lower 90s. && .DISCUSSION... Today, Tonight and Saturday: The Inland NW will see some slightly unsettled weather today, followed by a return to more benign weather for the start of the weekend. As for today, satellite shows a weak cold front and upper level trough pushing through western Washington. It is expected to cross the Cascades early this morning and bring some light showers near the Cascade crest and the far northern mountains. Meanwhile, a slug of mid level moisture is advecting northeastward from Oregon, ahead of the front; it is also within an area of mid level instability. The bulk of this moisture will stay to the south and east of the our region, but the fringes will skirt by the Lewiston area, the Camas prairie and the central ID mountains. There is the potential for light sprinkles and a lightning strike this morning with this elevated moisture band. Then by afternoon, surface based instability increases especially across the far NE WA mountains and the Idaho panhandle where isolated showers and thunderstorms are possible. An upper level jet will slide through the region this afternoon. Much of the air behind the front is dry which will advect across much of eastern Washington this afternoon under gusty westerly winds. Anticipate winds of 10 to 20 mph by late afternoon and early evening from the Wenatchee area and across the Columbia Basin. These conditions coupled with humidity values about the same as yesterday, in the upper teens to lower 20 percent, may cause some fire weather concerns in the grassy areas. The winds will taper off across the Columbia Basin early this evening, while downslope conditions will keep persistent winds in the Cascade valleys through the evening. Convection will decrease during the evening hours as well. By Saturday, a dry westerly flow aloft will prevail with not much in the way of convection. There looks to be a weak ripple passing in the flow, but surface pressure gradients will be more relaxed, leaning toward lighter winds. Little change in temperatures expected as they remain seasonal. /rfox Sunday through Tuesday: The medium range models are in good agreement that a shortwave high pressure ridge will set up over the Northern Rockies early next week. The 850mb thermal ridge is progged to peak Monday afternoon with temperatures near 20C. The ECMWF suggests that a weak push of slightly cooler air will arrive on Tuesday, but the GFS is a bit slower with the Pacific trough and cooler temperatures. While there is some uncertainty about the strength of the ridge next week, our confidence is relatively high that the Inland Northwest will experience 4 or 5 days of the warmest weather we have seen so far this year. Places like Lewiston, Moses Lake, Wenatchee and Omak will have a reasonable shot at reaching 90 degrees (on Monday) for the first time in 2014. Mid 80s will be within reach Monday for Spokane, Sandpoint, Coeur D`Alene and Kellogg. Rain chances Sunday and Monday look to be minimal with a strong mid-level cap under the heart of the upper ridge axis centered over Montana. Convection may become more of a possibility Tuesday especially if the stronger ECMWF trough verifies. 20-30 percent chances of showers and thunderstorms have been retained Tuesday into Tuesday night for the mountainous zones. /GKoch Tuesday night through Thursday night: The extended part of the forecast looks to be the transition period as we go from a mainly dry forecast back to a pattern that could lead to more widespread showers. Starting Tuesday night and through Wednesday night we will remain in a rather benign pattern as we continue in mainly dry southwesterly flow from earlier in the week. Mountain showers and isolated t-storms will be the main chance for precip as in the past as well. Temperatures remain above normal with the mild SW flow. Thursday and into Thursday night is when the pattern looks to become more active. Both models indicate an incoming trough of low pressure, but where they lack consistency is in exact timing. The Euro brings the feature in much earlier with the initial front passing Thursday. The GFS is much slower and holds off almost 24hrs bringing it though Friday. Timing is something that will have to be ironed out later, but both models show the system having a good moisture fetch allowing for a better chance of widespread precipitation. The trough along with the better chance for precip will also usher in cooler air bringing temps back closer to seasonal norms for the end of the week. With the passing system winds will also be on the increase, but should not lead to any problems. Behind the trough the region will remain in an active zonal flow with enough moisture and waves of energy to continue the chance of showers through the remainder of the work week. The exact details for the extended will have to be addressed later, but given current models a more active pattern appears to be on the horizon for the later part of next week. /Fliehman && .AVIATION... 06Z TAFS: A weak front will result in mainly mid and high clouds spreading into the region from west to east tonight and Friday. Main impact from this front will be increased west-southwest winds on Friday with gusts 20-25 kts common with the strongest gusts expected at KEAT, KGEG. Late tonight a band of elevated moisture/instability will produce some mid level cumulus clouds around KLWS/KPUW. The NAM model suggests a small chance of these developing into storms but most model data suggests better chances will be south of KLWS so left this TAF free of TS. Friday afternoon isolated thunderstorms are possible over the Idaho Panhandle (mainly east of KCOE) and far NE Washington (north of KGEG) so these TAF sites were also left dry. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 76 49 74 50 81 53 / 10 0 0 0 0 0 Coeur d`Alene 76 48 74 45 80 49 / 10 10 0 0 0 0 Pullman 74 44 73 40 79 45 / 10 10 0 0 0 0 Lewiston 83 52 82 50 86 55 / 20 10 0 0 0 0 Colville 77 47 78 46 84 49 / 10 10 0 0 0 0 Sandpoint 74 45 74 39 79 44 / 20 10 0 0 0 0 Kellogg 72 47 72 45 79 50 / 20 20 10 0 0 0 Moses Lake 81 51 79 50 87 56 / 0 0 0 0 0 10 Wenatchee 79 52 80 56 86 61 / 0 0 0 0 0 10 Omak 81 49 81 50 87 53 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
Area Forecast Discussion National Weather Service Spokane WA 252 AM PDT FRI JUN 20 2014 .SYNOPSIS... Warmer, drier, and more summer-like conditions will develop over the entire Inland Northwest this weekend into next week. Monday and Tuesday will likely be the warmest days early next week with afternoon temperatures in the mid 80s to lower 90s. && .DISCUSSION... Today, Tonight and Saturday: The Inland NW will see some slightly unsettled weather today, followed by a return to more benign weather for the start of the weekend. As for today, satellite shows a weak cold front and upper level trough pushing through western Washington. It is expected to cross the Cascades early this morning and bring some light showers near the Cascade crest and the far northern mountains. Meanwhile, a slug of mid level moisture is advecting northeastward from Oregon, ahead of the front; it is also within an area of mid level instability. The bulk of this moisture will stay to the south and east of the our region, but the fringes will skirt by the Lewiston area, the Camas prairie and the central ID mountains. There is the potential for light sprinkles and a lightning strike this morning with this elevated moisture band. Then by afternoon, surface based instability increases especially across the far NE WA mountains and the Idaho panhandle where isolated showers and thunderstorms are possible. An upper level jet will slide through the region this afternoon. Much of the air behind the front is dry which will advect across much of eastern Washington this afternoon under gusty westerly winds. Anticipate winds of 10 to 20 mph by late afternoon and early evening from the Wenatchee area and across the Columbia Basin. These conditions coupled with humidity values about the same as yesterday, in the upper teens to lower 20 percent, may cause some fire weather concerns in the grassy areas. The winds will taper off across the Columbia Basin early this evening, while downslope conditions will keep persistent winds in the Cascade valleys through the evening. Convection will decrease during the evening hours as well. By Saturday, a dry westerly flow aloft will prevail with not much in the way of convection. There looks to be a weak ripple passing in the flow, but surface pressure gradients will be more relaxed, leaning toward lighter winds. Little change in temperatures expected as they remain seasonal. /rfox Sunday through Tuesday: The medium range models are in good agreement that a shortwave high pressure ridge will set up over the Northern Rockies early next week. The 850mb thermal ridge is progged to peak Monday afternoon with temperatures near 20C. The ECMWF suggests that a weak push of slightly cooler air will arrive on Tuesday, but the GFS is a bit slower with the Pacific trough and cooler temperatures. While there is some uncertainty about the strength of the ridge next week, our confidence is relatively high that the Inland Northwest will experience 4 or 5 days of the warmest weather we have seen so far this year. Places like Lewiston, Moses Lake, Wenatchee and Omak will have a reasonable shot at reaching 90 degrees (on Monday) for the first time in 2014. Mid 80s will be within reach Monday for Spokane, Sandpoint, Coeur D`Alene and Kellogg. Rain chances Sunday and Monday look to be minimal with a strong mid-level cap under the heart of the upper ridge axis centered over Montana. Convection may become more of a possibility Tuesday especially if the stronger ECMWF trough verifies. 20-30 percent chances of showers and thunderstorms have been retained Tuesday into Tuesday night for the mountainous zones. /GKoch Tuesday night through Thursday night: The extended part of the forecast looks to be the transition period as we go from a mainly dry forecast back to a pattern that could lead to more widespread showers. Starting Tuesday night and through Wednesday night we will remain in a rather benign pattern as we continue in mainly dry southwesterly flow from earlier in the week. Mountain showers and isolated t-storms will be the main chance for precip as in the past as well. Temperatures remain above normal with the mild SW flow. Thursday and into Thursday night is when the pattern looks to become more active. Both models indicate an incoming trough of low pressure, but where they lack consistency is in exact timing. The Euro brings the feature in much earlier with the initial front passing Thursday. The GFS is much slower and holds off almost 24hrs bringing it though Friday. Timing is something that will have to be ironed out later, but both models show the system having a good moisture fetch allowing for a better chance of widespread precipitation. The trough along with the better chance for precip will also usher in cooler air bringing temps back closer to seasonal norms for the end of the week. With the passing system winds will also be on the increase, but should not lead to any problems. Behind the trough the region will remain in an active zonal flow with enough moisture and waves of energy to continue the chance of showers through the remainder of the work week. The exact details for the extended will have to be addressed later, but given current models a more active pattern appears to be on the horizon for the later part of next week. /Fliehman && .AVIATION... 06Z TAFS: A weak front will result in mainly mid and high clouds spreading into the region from west to east tonight and Friday. Main impact from this front will be increased west-southwest winds on Friday with gusts 20-25 kts common with the strongest gusts expected at KEAT, KGEG. Late tonight a band of elevated moisture/instability will produce some mid level cumulus clouds around KLWS/KPUW. The NAM model suggests a small chance of these developing into storms but most model data suggests better chances will be south of KLWS so left this TAF free of TS. Friday afternoon isolated thunderstorms are possible over the Idaho Panhandle (mainly east of KCOE) and far NE Washington (north of KGEG) so these TAF sites were also left dry. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 76 49 74 50 81 53 / 10 0 0 0 0 0 Coeur d`Alene 76 48 74 45 80 49 / 10 10 0 0 0 0 Pullman 74 44 73 40 79 45 / 10 10 0 0 0 0 Lewiston 83 52 82 50 86 55 / 20 10 0 0 0 0 Colville 77 47 78 46 84 49 / 10 10 0 0 0 0 Sandpoint 74 45 74 39 79 44 / 20 10 0 0 0 0 Kellogg 72 47 72 45 79 50 / 20 20 10 0 0 0 Moses Lake 81 51 79 50 87 56 / 0 0 0 0 0 10 Wenatchee 79 52 80 56 86 61 / 0 0 0 0 0 10 Omak 81 49 81 50 87 53 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
Area Forecast Discussion National Weather Service Spokane WA 1054 PM PDT THU JUN 19 2014 .SYNOPSIS... Warmer...drier and more summer-like conditions will return to the entire Inland NORTHWEST for the rest of the week, the weekend and into the very early part of next week. Expect breezy winds and a chance of showers and afternoon mountain thunderstorms Friday and again next week. && .DISCUSSION... The forecast has been updated to add a slight chance of thunderstorms for the Camas Prairie and southeast Shoshone County Friday morning, as well as increase sky cover. Also given current relative humidities and expected increase in mid/high level clouds tonight...patchy fog is no longer expected and was removed. Water Vapor and Infrared Satellite imagery as of 830 pm showed a well defined front stretching from NW Washington down to just off the Oregon coast. Rain has been falling along this front...but models are in good agreement that as the low near the north tip of Vancouver Island lifts north and weakens tonight...that the front will rapidly weaken as it crosses the Cascades. This combined with downslope westerly winds as the front crosses should leave areas outside of the Cascade crest generally dry with passing mid/high clouds with one exception. The past couple NAM model runs as well as the HRRR show elevated convection developing over the Camas Prairie near 12z (5 am Friday) as a band of elevated lift and instability moved up into the area ahead of the front. With the 00z NAM model showing 0-6km Most Unstable CAPE values of 200 J/KG with the CAPE layer extending from 700mb up to near 300mb...its possible isolated lightning strikes could fall out of this. If storms develop they would be high based and fast moving...with light rainfall amounts. The GFS is not as excited about this...but typically these elevated convection cases ahead of a front have shown the NAM have the edge over the GFS. JW && .AVIATION... 06Z TAFS: A weak front will result in mainly mid and high clouds spreading into the region from west to east tonight and Friday. Main impact from this front will be increased west-southwest winds on Friday with gusts 20-25 kts common with the strongest gusts expected at KEAT, KGEG. Late tonight a band of elevated moisture/instabilty will produce some mid level cumulus clouds around KLWS/KPUW. The NAM model suggests a small chance of these developing into storms but most model data suggests better chances will be south of KLWS so left this TAF free of TS. Friday afternoon isolated thunderstorms are possible over the Idaho Panhandle (mainly east of KCOE) and far NE Washington (north of KGEG) so these TAF sites were also left dry. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 52 76 50 75 48 82 / 0 10 0 0 0 0 Coeur d`Alene 49 76 48 75 48 82 / 0 10 10 0 0 0 Pullman 49 74 46 74 43 79 / 10 10 10 0 0 0 Lewiston 56 83 52 82 50 88 / 10 10 10 0 0 0 Colville 50 78 47 79 48 82 / 10 10 10 0 0 0 Sandpoint 46 75 46 75 44 83 / 10 20 10 0 0 0 Kellogg 48 73 48 74 46 79 / 0 20 20 10 10 10 Moses Lake 57 80 51 79 53 85 / 0 0 0 0 0 0 Wenatchee 61 79 51 80 54 87 / 0 0 0 0 0 0 Omak 54 81 48 80 47 85 / 10 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
910 PM PDT THU JUN 19 2014 .SYNOPSIS...AFTER A CLASSIC EARLY SUMMER DAY...CHANGES ARE IN STORE FOR THE REGION. A WEAKENING FRONT WILL PUSH ACROSS THE REGION TONIGHT...BRING SPOTTY LIGHT RAIN. COOLER WITH LOTS OF CLOUDS FOR FRIDAY. THEN THE PATTERN OF MORNING CLOUDS/AFTERNOON SUNSHINE EXPECTED FOR THE WEEKEND. MILD WEATHER CONTINUES NEXT WEEK...BUT MAY HAVE A FEW SHOWERS ABOUT THE AREA...MAINLY FROM OVER THE CASCADES AND POINTS EASTWARD. && .UPDATE...FRONT IS HOLDING ITSELF TOGETHER ALONG THE SOUTH WASHINGTON AND NORTH OREGON COAST...THOUGH IT WILL BE WEAKENING AS IT SHIFTS INLAND. CURRENT RADAR ECHOES INLAND HAVE BEEN SPRINKLES OR VIRGA. NO MAJOR CHANGES IN THINKING OTHER THAN TO ADD TEMPORAL RESOLUTION OF THE POP GRID TO ACCOUNT FOR TIMING AND TO LOWER THE CHANCES OF PRECIP FARTHER SOUTH INCLUDING IN THE LANE COUNTY LOWLANDS AND MOUNTAINS AS THE PRECIP WILL BE MORE BROKEN AND SCATTERED. SOUNDINGS SUGGEST AND OBSERVATIONS AT THE COAST CONFIRM THAT DEEP MOISTURE WILL BE LACKING...THEREFORE A BRIEF PERIOD OF LIGHT RAIN OR DRIZZLE IS THE MOST LIKELY OUTCOME INLAND.LATEST GRIDS WILL BE AVAILABLE IN THE NEXT 15 MINUTES OR SO. KMD && .SHORT TERM.. GREAT DAY TODAY...WITH MILD TEMPERATURES AND ABUNDANT SUNSHINE. EVEN THE COASTAL AREAS HAD A NICE START...WITH SUNSHINE AND TEMPERATURES INTO THE 60S. HOWEVER...ONSHORE FLOW NOW INCREASING ALONG THE COAST AND INTO THE INTERIOR. LOTS OF CLOUDS JUST OFF THE COAST WILL SURGE INLAND THROUGH THE EVENING. CLOUDS WILL BE AIDED BY THE APPROACHING WEAK FRONT THAT IS FURTHER OFFSHORE. THE FRONT WILL REACH THE COASTAL THIS EVENING...AND PUSH INLAND OVERNIGHT. NOT A LOT OF LIFT WITH THE FRONT...BUT SEEMS ENOUGH TO PRODUCE AREAS OF LIGHT RAIN OVER THE COAST AND COAST MTNS... WITH AREAS OF DRIZZLE OR SPOTTY BRIEF LIGHT RAIN INLAND LATER TONIGHT INTO EARLY FRI AM. HAVE ADJUSTED FORECAST/GRIDS TO REFLECT TRANSITION INTO CLOUDS THIS EVENING. ALSO...BOOSTED POPS TO NEAR 80 PERCENT OVER GOOD PART OF THE REGION FOR OCCASIONAL RAIN OR DRIZZLE LATER TONIGHT. SEEMS THIS WILL BE A HIGH POP-LOW QPF EVENT. IN OTHER WORDS...GOOD CHANCE OF RAIN BUT NOT MUCH IN WAY OF AMOUNTS. MAIN EFFECT FROM THE FRONT WILL BE A PLETHORA OF CLOUDS THAT WILL PERSIST WELL INTO FRI AFTERNOON OVER THE INTERIOR CLOUDS WILL BREAK LATE FRI AFTERNOON AND EVENING INLAND...MAINLY SOUTH AND EAST OF SALEM. STILL HAVE ONSHORE FLOW THIS WEEKEND. BUT NOT THREAT OF RAIN. SO LOOKS THAT WILL HAVE CLASSIC JUNE PATTERN OF MORNING CLOUDS GIVING WAY TO AFTERNOON SUNSHINE. TEMPERATURES MODERATE BACK TO SEASONABLE LEVELS...WHICH MEANS LOWER TO MIDDLE 70S OVER INTERIOR LOWLANDS. ONSHORE FLOW WEAKER ON SUNDAY...SO SHOULD SEE LESS EXTENT OF LOW CLOUDS OVER INTERIOR SUNDAY AM.ROCKEY. .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. SUNDAY NIGHT THROUGH WEDNESDAY... UPPER LEVEL LOW PRESSURE WILL REMAIN OVER THE NE PAC THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THIS WILL RESULT IN PERSISTENT ONSHORE FLOW...WITH OVERNIGHT AND EARLY MORNING STRATUS PUSHES FOLLOWED BY PARTIAL CLEARING DURING THE AFTERNOON. EXPECT TEMPS TO RUN NEAR SEASONAL AVERAGES. IT APPEARS THAT THE UPPER LEVEL TROUGH MAY PUSH TOWARD THE PAC NW BY THE MIDDLE OF NEXT WEEK...WHICH WILL BRING INCREASING PRECIP CHANCES. ADDED A SLIGHT CHANCE FOR PRECIPITATION TO THE FCST FOR TUE AND WED...ESPECIALLY OVER THE HIGHER MOUNTAINOUS TERRAIN. PYLE && .AVIATION...MVFR CONDITIONS AND RAIN SHOWERS CURRENTLY APPROACHING THE COAST WILL SPREAD INLAND OVERNIGHT. HOWEVER...THIS SYSTEM WILL BE WEAKENING AS IT PROGRESSES INLAND. IN ADDITION...A SHALLOW BUT UNSTABLE POST FRONTAL ATMOSPHERE SHOULD CAUSE ANY MVFR CONDITIONS THAT DEVELOP INLAND OVERNIGHT TO DISSIPATE QUICKLY AFTER 12Z FRIDAY. IT SHOULD ALSO BE NOTED THERE MAY BE SOME BRIEF REDUCTIONS INTO HIGH END IFR ALONG THE COAST THROUGH APPROXIMATELY 09Z FRIDAY. VFR CONDITIONS ARE THEN EXPECTED THROUGH 06Z SATURDAY. KPDX AND APPROACHES...EXPECT PRIMARILY VFR CONDITIONS THROUGH 06Z SATURDAY. THERE WILL BE A COUPLE HOUR WINDOW BETWEEN PRIMARILY 07Z AND 13Z FRIDAY WHERE MVFR CONDITIONS SHOULD BRIEFLY OCCUR. /NEUMAN && .MARINE...A LOW PRESSURE SYSTEM TRACKING NORTH OF VANCOUVER ISLAND IS PUSHING A FRONTAL SYSTEM ACROSS THE WATERS THIS EVENING. WINDS HAVE GENERALLY REMAINED BELOW SMALL CRAFT ADVISORY LEVELS...BUT WILL KEEP THE ADVISORY GOING FOR A COUPLE MORE HOURS BEFORE PULLING IT EARLY. SEAS SHOULD COME UP TONIGHT INTO THE 6 TO 8 FT RANGE. MODEL GUIDANCE SUGGESTS DOMINANT PERIODS SHOULD REMAIN NEAR 10 SECONDS...BUT BUOY 89 DOES HAVE WIND WAVES CURRENTLY DOMINATING THEIR SEA STATE. AS A RESULT...A SMALL CRAFT ADVISORY FOR STEEP CHOPPY HAZARDOUS SEAS IS STILL POSSIBLE. WE WILL CONTINUE TO MONITOR TRENDS. OTHERWISE...A COUPLE WEEK FRONTAL SYSTEMS WILL TRACK ACROSS THE WATERS EARLY NEXT WEEK...BUT NO MAJOR WIND OR SEA ISSUES APPEAR IN STORE. /NEUMAN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT FRIDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. && $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND 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 National Weather Service Spokane WA 848 PM PDT THU JUN 19 2014 .SYNOPSIS... Warmer...drier and more summer-like conditions will return to the entire Inland NORTHWEST for the rest of the week, the weekend and into the very early part of next week. Expect breezy winds and a chance of showers and afternoon mountain thunderstorms Friday and again next week. && .DISCUSSION... The forecast has been updated to add a slight chance of thunderstorms for the Camas Prairie and southeast Shoshone County Friday morning, as well as increase sky cover. Also given current relative humidities and expected increase in mid/high level clouds tonight...patchy fog is no longer expected and was removed. Water Vapor and Infrared Satellite imagery as of 830 pm showed a well defined front stretching from NW Washington down to just off the Oregon coast. Rain has been falling along this front...but models are in good agreement that as the low near the north tip of Vancouver Island lifts north and weakens tonight...that the front will rapidly weaken as it crosses the Cascades. This combined with downslope westerly winds as the front crosses should leave areas outside of the Cascade crest generally dry with passing mid/high clouds with one exception. The past couple NAM model runs as well as the HRRR show elevated convection developing over the Camas Prairie near 12z (5 am Friday) as a band of elevated lift and instability moved up into the area ahead of the front. With the 00z NAM model showing 0-6km Most Unstable CAPE values of 200 J/KG with the CAPE layer extending from 700mb up to near 300mb...its possible isolated lightning strikes could fall out of this. If storms develop they would be high based and fast moving...with light rainfall amounts. The GFS is not as excited about this...but typically these elevated convection cases ahead of a front have shown the NAM have the edge over the GFS. JW && .AVIATION... 00Z TAFS: A weak front will result in mainly mid and high clouds spreading into the region from west to east tonight and Friday. Main impact from this front will be increased west-southwest winds on Friday with gusts 15-25 kts common with the strongest gusts expected at KEAT, KGEG. Late tonight a band of elevated moisture/instabilty may produce some mid level cumulus clouds around KLWS/KPUW. The NAM model suggests a small chance of these developing into storms but most model data suggests better chances will be south of KLWS so left this TAF free of TS. Friday afternoon isolated thunderstorms are possible over the Idaho Panhandle (mainly east of KCOE) and far NE Washington (north of KGEG) so these TAF sites were also left dry. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 52 76 50 75 48 82 / 0 10 0 0 0 0 Coeur d`Alene 49 76 48 75 48 82 / 0 10 10 0 0 0 Pullman 49 74 46 74 43 79 / 10 10 10 0 0 0 Lewiston 56 83 52 82 50 88 / 10 10 10 0 0 0 Colville 50 78 47 79 48 82 / 10 10 10 0 0 0 Sandpoint 46 75 46 75 44 83 / 10 20 10 0 0 0 Kellogg 48 73 48 74 46 79 / 0 20 20 10 10 10 Moses Lake 57 80 51 79 53 85 / 0 0 0 0 0 0 Wenatchee 61 79 51 80 54 87 / 0 0 0 0 0 0 Omak 54 81 48 80 47 85 / 10 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
447 AM CDT FRI JUN 20 2014 .TODAY...FORECAST CONFIDENCE IS MEDIUM. CURRENT BAND OF LIGHT SHOWERS BEING DRIVEN BY IMPULSE ROTATING AROUND EASTERN FLANK OF CLOSED 500 MB LOW WATER VAPOR IMAGERY SHOWS MOVING EAST ALONG THE U.S./CANADIAN BORDER OVER NORTHEAST MONTANA/SASKATCHEWAN. THE IMPULSE...AND THE WEAK SURFACE REFLECTION OF THIS IMPULSE...CROSS SRN WI THIS MORNING REACHING THE FAR SE CORNER OF WI/NE IL BY 18Z. CURRENT TIMING PUSHES PCPN EAST OF STATE BY 15Z AT THE LATEST...BUT SOME CONCERN ABOUT LOW LEVEL CONVERGENCE/FRONTOGENETIC RESPONSE IN THE EAST BEHIND LOW. MODEL SOUNDINGS SHOW THE COLUMN DRYING BEHIND THIS IMPULSE...NO DOUBT AIDED BY SUBSIDENCE ASSOCIATED WITH UPPER LEVEL CONVERGENCE IN RIGHT EXIT REGION OF UPPER JETLET ON SRN EDGE OF THE CLOSED UPPER LOW THAT SPREADS ACROSS SRN WI LATE THIS MORNING/AFTERNOON. HOWEVER CONCERN ABOUT THE INCREASING CAPE VALUES AND STEEP LOW- LEVEL LAPSE RATES WITH DAYTIME HEATING. WILL NOT HAVE POPS IN THE EAST PAST 20Z BUT LATEST HRRR DOES SHOW SOME SCATTERED PCPN IN CONVERGENCE FARTHER INLAND. .TONIGHT...FORECAST CONFIDENCE IS MEDIUM. MOST OF THE NIGHT IS QUIET...BUT NEAR ZONAL FLOW BRINGS A WEAK SHORT WAVE TOWARD THE REGION BY 12Z SATURDAY. WILL LIMIT SLIGHT CHANCE POPS TO THE FAR NORTHWEST WITH LOW EXPECTATION OF ANYTHING MEASURABLE AS LIMITED MOISTURE AVAILABLE MAINLY IN THE MID LEVELS. .SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. SHORT TERM MODELS GENERALLY SHOWING A MESOSCALE CONVECTIVE SYSTEM SHIFTING FROM NORTHERN IOWA TO SOUTHEAST IOWA AND NORTHERN ILLINOIS SATURDAY AND SATURDAY NIGHT. SOME VARIATION IN THE TRACK OF THIS FEATURE. MODELS ALSO TRYING TO GENERATE QPF WITHIN WEAK WARM AIR ADVECTION REGIME AND MOIST/UNSTABLE AIRMASS. WEAK LOW LEVEL FRONTOGENESIS RESPONSE ALSO SEEN IN THE AREA. NAM/GFS DIFFER ON MEAN LAYER CAPES...BUT ADJUSTING TEMPERATURE/DEW POINTS IN LOWEST 100 MB MEAN LAYER SUGGESTS 1000 TO 1500 J/KG AT LEAST. NAM CAPPED WITH GFS MOSTLY UNCAPPED SATURDAY...WITH NAM LOSING INSTABILITY SATURDAY NIGHT. DEEP LAYER SHEAR IS MODEST SATURDAY ON NAM...WEAK ON GFS. BOTH ARE WEAK WITH SHEAR SATURDAY NIGHT. FOR NOW...CONTINUED POPS FOR THIS PERIOD. NO ALL DAY RAINFALL IS EXPECTED AT THIS TIME. WARM AND HUMID CONDITIONS WILL CONTINUE AWAY FROM LAKE MICHIGAN. MODELS DIFFER MORE WITH SUNDAY AND SUNDAY NIGHT...AS NAM/ECMWF/CANADIAN MODELS ARE FAIRLY DRY WITH INFLUENCE OF HIGH PRESSURE TO THE NORTHEAST OF THE REGION. GFS CONTINUES TO HAVE WEAK WARM AIR ADVECTION AND QPF WITHIN MOIST/UNSTABLE AIRMASS...WITH NAM SHOWING MORE ELEVATED CAPE PROFILES. FOR NOW...WILL CONTINUE CHANCE POPS FOR THIS PERIOD. MAY HAVE TO RAMP DOWN POPS IN LATER FORECASTS IF DRIER LOOK CONTINUES ON NAM/ECMWF/CANADIAN MODELS. WARM AND HUMID AGAIN AWAY FROM THE LAKE ON SUNDAY. .LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS MEDIUM. ECMWF/GFS BRING LOW PRESSURE NORTHEAST THROUGH THE REGION MONDAY INTO EARLY TUESDAY...ALONG WITH A COLD FRONT AND 500 MB SHORTWAVE TROUGH. THIS SHOULD RESULT IN DECENT CHANCES FOR SHOWERS AND THUNDERSTORMS. CONTINUED HIGHER END POPS FOR MONDAY AND MONDAY NIGHT...SLIGHTLY LOWER ON TUESDAY. WARM AND HUMID CONDITIONS SHOULD CONTINUE. A BIT MORE UNCERTAINTY FURTHER OUT IN THE FORECAST...SO WILL USE CONSENSUS POPS AND TEMPERATURES FOR THIS PERIOD. IT APPEARS THAT A COOLER AND LESS HUMID AIRMASS MAY MOVE INTO THE REGION AFTER THE COLD FRONTAL PASSAGE TUESDAY...AND PERHAPS A DRY PERIOD WITH HIGH PRESSURE. SOME QPF OCCURS FROM TIME TO TIME...SO NOT SOLD ON A DRY FORECAST JUST YET. .AVIATION/12Z TAFS/...PER WESTERN OBSERVATIONS LIFR CIGS EXPECTED TO LIFT TO MVFR AFTER PASSAGE OF LAST POCKET OF SHOWERS CROSSES REGION EARLY THIS MORNING. VSBYS ARE ANOTHER QUESTION AS A BREAK IN THE LOWER CIGS HAS ALLOWED ENOUGH COOLING FOR 1/2 TO 1/4 MILE VSBYS AT KUGN AND KENW. DENSE FOG HAS FORMED WHERE SKIES CLEARED IN IOWA. WILL WATCH CLOSELY BUT EXPECT PREVAILING VSBYS TO HOLD BETWEEN 1 AND 2 MILES...THEN IMPROVE AFTER DAYBREAK AND PASSAGE OF THE LAST OF THE RAIN SHOWERS. WILL KEEP CIGS AT MVFR LEVELS UNTIL EARLY AFTERNOON THEN VFR CONDITIONS WHEN DRIER AIR MOVES IN BEHIND WEAK SURFACE LOW. LIGHT WINDS AND MOIST CONDITIONS BRING A GOOD POTENTIAL OF FOG TONIGHT. SREF PROBABILITIES FOR LESS THAN 3 MILE VSBYS JUMP UP AFTER 06Z...WITH LESS THAN 1 MILE CHANCES FOCUSED NEAR KBUU AND KENW. WILL HOLD VSBYS AT MVFR LEVELS EXCEPT AT KENW WITH IFR BETWEEN 09Z AND 12Z. .MARINE...CURRENT WEB CAMS NOT SHOWING FOG ALONG THE IMMEDIATE SHORE BUT APPEARS TO BE SOME OFFSHORE FOG. WILL KEEP MENTION OF AREAS OF FOG THROUGH THE DAY UNTIL NORTHEAST WINDS LATER THIS AFTERNOON SCOUR OUT HIGHER DEW POINT AIR OVER THE LAKE. POTENTIAL FOR FOG RETURNS WITH HIGHER DEW POINTS SATURDAY AHEAD OF NEXT WEAK SYSTEM. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SATURDAY THROUGH THURSDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
342 AM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 342 AM CDT FRI JUN 20 2014 THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TONIGHT THROUGH SUNDAY. LOCAL AND REGIONAL RADARS THIS MORNING SHOWING MOST OF THE SHOWERS THIS MORNING WERE OVER THE NORTHERN AND EASTERN SECTIONS OF WISCONSIN WITH JUST SOME WIDELY SCATTERED ACTIVITY OVER THE CENTRAL PART OF THE STATE. THESE SHOWERS WERE MOVING OFF TO THE NORTH/NORTHEAST AND THE 20.05Z HRRR SUGGESTS THESE SHOULD MOVE OUT OF THE FORECAST AREA BY 12Z. WILL MONITOR THE RADAR TRENDS BUT MAY HAVE TO START THE MORNING WITH A VERY SMALL RAIN CHANCE ACROSS THE FAR NORTHERN AND EASTERN PARTS OF THE FORECAST AREA WITH ANY REMAINING SHOWERS EXPECTED TO BE COMPLETELY OUT OF THE AREA BY MID MORNING. THE UPPER LEVEL LOW OVER SASKATCHEWAN WILL LIFT SLOWLY NORTHEAST THROUGH TONIGHT AND BECOME AN OPEN WAVE OVER SOUTHERN MANITOBA AND WESTERN ONTARIO ALLOWING THE FLOW OVER THE UPPER MIDWEST TO BECOME ZONAL. ONE SHORT WAVE TROUGH ROUNDING THE REMAINS OF THIS UPPER LEVEL LOW IS EXPECTED TO MOVE ACROSS NORTHERN MINNESOTA TONIGHT WITH ANOTHER WEAKER WAVE COMING OUT OF THE ROCKIES AND ACROSS NEBRASKA AND SOUTHERN IOWA. NOT A LOT OF PV ADVECTION WITH EITHER OF THESE WAVES...BUT ENOUGH WARM AIR ADVECTION SHOULD OCCUR TO PRODUCE 4 TO 6 UBAR/S OF UP GLIDE ON THE 305K ISENTROPIC SURFACE. THE MODELS ARE SPLIT ON HOW MUCH AND WHERE THE MOISTURE TRANSPORT WILL BE WITH THESE WAVES. THE 20.00Z NAM SUGGESTS WEAK TRANSPORT SHOULD OCCUR AHEAD OF THE NORTHERN WAVE INTO NORTHERN WISCONSIN AND MINNESOTA WHILE THE 20.00Z GFS AND ECMWF HAVE THE MOISTURE TRANSPORT AHEAD OF THE SOUTHERN WAVE INTO NEBRASKA WHERE THEY DEVELOP A CONVECTIVE COMPLEX. THE GFS THEN KEEPS THIS COMPLEX GENERALLY SOUTH OF THE AREA WHILE THE ECMWF BRINGS INTO THE THE AREA. THE 20.03Z SREF PROBABILITIES TEND TO FAVOR THE GFS SOLUTION WITH THE CONVECTIVE COMPLEX BUT ALSO HAVE SOME LOW PROBABILITIES ACROSS THE NORTH SIMILAR TO THE NAM. WITH SUCH WEAK FORCING SIGNALS AND DIFFERING MODEL SOLUTIONS...WILL JUST HAVE SOME LOW RAIN CHANCES ACROSS MOST THE AREA FOR THE OVERNIGHT HOURS. THE ZONAL FLOW CONTINUES INTO SATURDAY WITH ALL THE MODELS SHOWING ANOTHER WEAK WAVE COMING ACROSS THE NORTHERN ROCKIES INTO THE UPPER MIDWEST. THE GFS IS THE FARTHEST NORTH BRINGING THIS ACROSS MINNESOTA INTO IOWA WHILE THE NAM AND ECMWF TAKE IT ACROSS IOWA. THIS RESULTS IN BIG DIFFERENCES IN HOW MUCH AND WHERE THE RAIN COULD FALL. THE NAM AND ECMWF KEEP THE MAJORITY OF THE RAIN TO THE SOUTH OF THE AREA WHILE THE GFS WOULD INDICATE ALL OF THE FORECAST AREA WOULD HAVE A CHANCE FOR GETTING WET. AGAIN...THE SREF PROBABILITIES FAVOR THE NAM AND ECMWF SOLUTIONS SO PLAN TO SHOW 20 TO 30 PERCENT CHANCES THROUGH THE DAY WITH THESE HIGHEST ACROSS THE SOUTH. THE RAIN THAT DEVELOPS SATURDAY SHOULD CONTINUE ACROSS THE SOUTH INTO SATURDAY EVENING BEFORE STARTING TO MOVE OFF TO THE EAST SATURDAY NIGHT. A STRONGER SHORT WAVE TROUGH IS EXPECTED TO MOVE OUT OF THE ROCKIES AND START TO APPROACH THE AREA SUNDAY. THE PV ADVECTION IN THE 500-300 MB LAYER WILL STAY TO THE WEST OF THE AREA. THE ISENTROPIC UP GLIDE AHEAD OF THIS WAVE SHOULD MOVE INTO THE WESTERN SECTIONS OF IOWA AND MINNESOTA BY LATE IN THE DAY SUNDAY. IF THE MODELS REMAIN CONSISTENT WITH THESE SIGNALS...THE BEST RAIN CHANCES SHOULD BE CONFINED TO THE WESTERN SECTIONS OF THE FORECAST AREA AND THE EASTERN SECTIONS COULD BE DRY...BUT WITH THE GFS BEING QUICKER TO MOVE THIS SYSTEM IN...WILL SHOW A 30 TO 40 PERCENT CHANCE FROM EAST TO WEST. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 AM CDT FRI JUN 20 2014 THE MODEL DIFFERENCE CONTINUE INTO EARLY NEXT WEEK AS WELL. GENERAL CONSENSUS THAT THE SHORT WAVE TROUGH THAT COMES OUT SUNDAY WILL WEAKEN AS IT MOVES TOWARD MINNESOTA IN FAVOR OF ANOTHER WAVE COMING ACROSS NEBRASKA OR KANSAS. THE ECMWF THEN TAKES THIS WAVE NORTHEAST AND INTO THE GREAT LAKES REGION THROUGH MONDAY WHILE THE GFS AMPLIFIES THIS FORMING AN UPPER LEVEL LOW OVER THE UPPER MIDWEST MONDAY NIGHT WITH THE 20.00Z GEM DOING SOMETHING VERY SIMILAR. BOTH THE ECMWF AND GFS THEN SHOW WEAK RIDGING BUILDING OVER THE UPPER MIDWEST BY THE END OF PERIOD WITH THE ECMWF QUICKER TO DO THIS THAN THE GFS. BECAUSE OF THE DIFFERENCES BETWEEN THE MODELS...WILL HAVE SOME RAIN CHANCES THROUGH THE ENTIRE PERIOD WITH THE HIGHEST CHANCES MONDAY INTO MONDAY NIGHT WHEN THE FORCING FROM THE WAVE SHOULD BE THE STRONGEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1212 AM CDT FRI JUN 20 2014 IN THE WAKE OF THE EARLIER CONVECTION...IFR CLOUDS HAVE DEVELOPED ACROSS THE AREA. THE LONE EXCEPTION IS KRST. THINKING WITH THE LIGHT WINDS AND CLEARING SKIES THAT THE IFR CONDITIONS WILL SPREAD INTO THAT TAF SITE TOO. AS DRY AIR MOVES INTO THE REGION ON FRIDAY MORNING...SKIES WILL CLEAR AND REMAIN THAT WAY THROUGH FRIDAY EVENING. && .HYDROLOGY... ISSUED AT 342 AM CDT FRI JUN 20 2014 WITH ALL THE RECENT RAINS...NUMEROUS RIVERS AND STREAMS HAVE FLOODING ALONG THEM RESULTING IN AREAL AND RIVER FLOOD WARNINGS. WITH A DRY DAY TODAY...SOME OF THE WATER MAY RECEDE ENOUGH TO ALLOW THE AREAL FLOOD WARNINGS TO BE DISCONTINUED OR MADE SMALLER IN SIZE. HOWEVER...MANY OF THE RIVERS WILL REMAIN ABOVE FLOOD STAGE INTO THE WEEKEND. WHILE ADDITIONAL RAINFALL IS IN THE FORECAST THROUGH THE WEEKEND...EXPECTED AMOUNTS AT THIS TIME SHOULD NOT BE ENOUGH TO AGGRAVATE EXISTING FLOODING PROBLEMS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...BOYNE HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
338 AM CDT FRI JUN 20 2014 .TODAY...FORECAST CONFIDENCE IS MEDIUM. CURRENT BAND OF LIGHT SHOWERS BEING DRIVEN BY IMPULSE ROTATING AROUND EASTERN FLANK OF CLOSED 500 MB LOW WATER VAPOR IMAGERY SHOWS MOVING EAST ALONG THE U.S./CANADIAN BORDER OVER NORTHEAST MONTANA/SASKATCHEWAN. THE IMPULSE...AND THE WEAK SURFACE REFLECTION OF THIS IMPULSE...CROSS SRN WI THIS MORNING REACHING THE FAR SE CORNER OF WI/NE IL BY 18Z. CURRENT TIMING PUSHES PCPN EAST OF STATE BY 15Z AT THE LATEST...BUT SOME CONCERN ABOUT LOW LEVEL CONVERGENCE/FRONTOGENETIC RESPONSE IN THE EAST BEHIND LOW. MODEL SOUNDINGS SHOW THE COLUMN DRYING BEHIND THIS IMPULSE...NO DOUBT AIDED BY SUBSIDENCE ASSOCIATED WITH UPPER LEVEL CONVERGENCE IN RIGHT EXIT REGION OF UPPER JETLET ON SRN EDGE OF THE CLOSED UPPER LOW THAT SPREADS ACROSS SRN WI LATE THIS MORNING/AFTERNOON. HOWEVER CONCERN ABOUT THE INCREASING CAPE VALUES AND STEEP LOW- LEVEL LAPSE RATES WITH DAYTIME HEATING. WILL NOT HAVE POPS IN THE EAST PAST 20Z BUT LATEST HRRR DOES SHOW SOME SCATTERED PCPN IN CONVERGENCE FARTHER INLAND. .TONIGHT...FORECAST CONFIDENCE IS MEDIUM. MOST OF THE NIGHT IS QUIET...BUT NEAR ZONAL FLOW BRINGS A WEAK SHORT WAVE TOWARD THE REGION BY 12Z SATURDAY. WILL LIMIT SLIGHT CHANCE POPS TO THE FAR NORTHWEST WITH LOW EXPECTATION OF ANYTHING MEASURABLE AS LIMITED MOISTURE AVAILABLE MAINLY IN THE MID LEVELS. .SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. SHORT TERM MODELS GENERALLY SHOWING A MESOSCALE CONVECTIVE SYSTEM SHIFTING FROM NORTHERN IOWA TO SOUTHEAST IOWA AND NORTHERN ILLINOIS SATURDAY AND SATURDAY NIGHT. SOME VARIATION IN THE TRACK OF THIS FEATURE. MODELS ALSO TRYING TO GENERATE QPF WITHIN WEAK WARM AIR ADVECTION REGIME AND MOIST/UNSTABLE AIRMASS. WEAK LOW LEVEL FRONTOGENESIS RESPONSE ALSO SEEN IN THE AREA. NAM/GFS DIFFER ON MEAN LAYER CAPES...BUT ADJUSTING TEMPERATURE/DEW POINTS IN LOWEST 100 MB MEAN LAYER SUGGESTS 1000 TO 1500 J/KG AT LEAST. NAM CAPPED WITH GFS MOSTLY UNCAPPED SATURDAY...WITH NAM LOSING INSTABILITY SATURDAY NIGHT. DEEP LAYER SHEAR IS MODEST SATURDAY ON NAM...WEAK ON GFS. BOTH ARE WEAK WITH SHEAR SATURDAY NIGHT. FOR NOW...CONTINUED POPS FOR THIS PERIOD. NO ALL DAY RAINFALL IS EXPECTED AT THIS TIME. WARM AND HUMID CONDITIONS WILL CONTINUE AWAY FROM LAKE MICHIGAN. MODELS DIFFER MORE WITH SUNDAY AND SUNDAY NIGHT...AS NAM/ECMWF/CANADIAN MODELS ARE FAIRLY DRY WITH INFLUENCE OF HIGH PRESSURE TO THE NORTHEAST OF THE REGION. GFS CONTINUES TO HAVE WEAK WARM AIR ADVECTION AND QPF WITHIN MOIST/UNSTABLE AIRMASS...WITH NAM SHOWING MORE ELEVATED CAPE PROFILES. FOR NOW...WILL CONTINUE CHANCE POPS FOR THIS PERIOD. MAY HAVE TO RAMP DOWN POPS IN LATER FORECASTS IF DRIER LOOK CONTINUES ON NAM/ECMWF/CANADIAN MODELS. WARM AND HUMID AGAIN AWAY FROM THE LAKE ON SUNDAY. .LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS MEDIUM. ECMWF/GFS BRING LOW PRESSURE NORTHEAST THROUGH THE REGION MONDAY INTO EARLY TUESDAY...ALONG WITH A COLD FRONT AND 500 MB SHORTWAVE TROUGH. THIS SHOULD RESULT IN DECENT CHANCES FOR SHOWERS AND THUNDERSTORMS. CONTINUED HIGHER END POPS FOR MONDAY AND MONDAY NIGHT...SLIGHTLY LOWER ON TUESDAY. WARM AND HUMID CONDITIONS SHOULD CONTINUE. A BIT MORE UNCERTAINTY FURTHER OUT IN THE FORECAST...SO WILL USE CONSENSUS POPS AND TEMPERATURES FOR THIS PERIOD. IT APPEARS THAT A COOLER AND LESS HUMID AIRMASS MAY MOVE INTO THE REGION AFTER THE COLD FRONTAL PASSAGE TUESDAY...AND PERHAPS A DRY PERIOD WITH HIGH PRESSURE. SOME QPF OCCURS FROM TIME TO TIME...SO NOT SOLD ON A DRY FORECAST JUST YET. && .AVIATION/12Z TAFS/...COMING SOON. && .MARINE...COMING SOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SATURDAY THROUGH THURSDAY...WOOD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
428 AM MDT FRI JUN 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM MDT FRI JUN 20 2014 CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING WEAK WESTERLY FLOW ALOFT ACROSS THE REGION AS A MINOR DISTURBANCE (BEST SEEN IN PV FIELDS) EMBEDDED WITHIN THE FLOW IS TRANSLATING ACROSS THE STATE AT THIS TIME. THIS DISTURBANCE...ALONG WITH A LOW LEVEL JET AND AMPLE LOW LEVEL MOISTURE...IS HELPING TO PRODUCE A FEW SHOWERS AND THUNDERSTORMS ACROSS BENT...PROWERS AND KIOWA COUNTIES AT THIS TIME. LATEST HI RES HRRR AND RUC MODELS...WHICH PICKED UP ON THIS DEVELOPMENT LAST EVENING...MOVE THE DISTURBANCE AND STORMS EAST INTO WESTERN KANSAS THROUGH 12Z FRI. TODAY AND TONIGHT...MODELS KEEP WEAK WESTERLY FLOW ALOFT ACROSS THE REGION THROUGH TONIGHT...AND WITH NO EVIDENT DISTURBANCE PROGGED WITHIN THE FLOW...ANY STORMS TODAY LOOK TO BE INITIATED BY SOLAR HEATING. WITH THAT SAID...LATEST MODELS REMAIN CONSISTENT WITH DEVELOPING STORMS ACROSS THE FAR SE PLAINS...GENERALLY EAST OF A KIM TO HASWELL LINE...WHERE CONVECTIVE TEMPS ARE IN THE LOW 90S AND DEW PTS ARE PROGGED IN THE 40S TO LOWER 50S THIS AFTERNOON. THERE IS NOT MUCH SHEAR ACROSS THE STATE WITH THE WEAK FLOW ALOFT...THOUGH WITH CAPES BETWEEN 600-1200 J/KG...COULD SEE A FEW STRONGER STORMS PRODUCING SMALL HAIL AND GUSTY WINDS. FURTHER WEST...DRY AIR ALOFT HELPS TO MIX OUT DEW PTS IN THE 20S AND 30S ACROSS THE HIGHER TERRAIN AND IMMEDIATE ADJACENT PLAINS THROUGH THE AFTERNOON. HOWEVER...WITH STRONG SOLAR HEATING AND MID LEVEL LAPSE RATES AROUND 9C/KM...CANT RULE CU BUILDUPS AND AN ISOLATED HIGH BASED STORM ACROSS THE EASTERN MTS. TEMPS ALOFT WARM A FEW DEGREES AND SHOULD SEE HIGHS SOME 3-6F WARMER THAN YESTERDAY...MOST NOTABLE ACROSS THE EASTERN PLAINS. SHOULD SEE STORMS DIMINISHING AND CLEARING SKIES AFTER SUNSET...THOUGH WITH ANOTHER LOW LEVEL JET PROGGED ACROSS NEAR THE WESTERN KANSAS BORDER...HAVE KEPT SLIGHT POPS ACROSS THE FAR SE PLAINS THROUGH THE OVERNIGHT HOURS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 334 AM MDT FRI JUN 20 2014 .SATURDAY...A WEAK DISTURBANCE WILL PASS MOSTLY NORTH OF THE REGION DURING THE AFTERNOON AND EARLY EVENING. SURFACE LOW PRESSURE WILL DEVELOP OVER SOUTHEAST COLORADO...KEEPING MOST OF THE EASTERLY LOW LEVEL FLOW NORTH OF THE CWA. MODEL SOUNDINGS SHOW SOME MODEST CAPES DURING THE AFTERNOON AND EARLY EVENING OVER THE PLAINS AND EASTERN MOUNTAINS. SUSPECT THE BEST LOW LEVEL MOISTURE WILL STAY NORTH OF THE CWA. HAVE ISOLATED POPS OVER MUCH OF THE REGIONS SATURDAY AFTERNOON AND EVENING. SPC KEEPS SLIGHT RISK OVER NORTHEAST COLORADO ON SATURDAY. CONVECTION MAY TAP INTO BETTER LOW LEVEL MOISTURE NEAR THE KANSAS BORDER AND INCREASED POPS TO SCATTERED CATEGORY SATURDAY EVENING. .SUNDAY...NEXT DISTURBANCE PASSES TO THE NORTH OF THE REGION DURING THE DAY. BEST LOW LEVEL MOISTURE STAYS MOSTLY TO THE NORTH OF THE CWA. INCREASED POPS TO SCATTERED OVER EL PASO AND KIOWA COUNTIES AS COLD FRONT AND ASSOCIATED INCREASE IN LOW LEVEL MOISTURE COULD BE OVER THESE AREAS. AS THE TROUGH PASSES TO THE EAST OF THE REGION...PATTERN CHANGE BEGINS AS THE FLOW ALOFT BECOMES NORTHWESTERLY. SOME MODELS HINT AT A SECONDARY DISTURBANCE PASSING OVER THE REGION SUNDAY EVENING...AFTER THE COLD FRONT HAS PASSED SOUTH OF THE CWA. WITH INCREASED LOW LEVEL MOISTURE... THERE COULD BE A SECOND ROUND OF CONVECTION SUNDAY EVENING...AND INCREASED POPS NEAR THE KANSAS BORDER SUNDAY EVENING. .MONDAY THROUGH WEDNESDAY...NORTHWEST FLOW ALOFT DEVELOPS OVER THE REGION...WITH WEAK EMBEDDED DISTURBANCES. AT THE SURFACE...HIGH PRESSURE OVER THE NORTHERN PLAINS WILL KEEP LOW LEVEL EASTERLY FLOW OVER THE EASTERN HALF OF THE CWA. THIS PATTERN IS PRONE TO PERIODS OF SEVERE CONVECTIVE WEATHER...ESPECIALLY ON THE PLAINS. AMOUNT...INTENSITY AND EXACT LOCATION OF STORMS WILL DEPEND ON SUBTLE FEATURES WHICH ARE DIFFICULT TO FORECAST THIS FAR OUT. MODELS HAVE 30 TO 50 KNOTS OF BULK SHEAR EACH DAY...WHICH IS SUFFICIENT FOR SEVERE WEATHER. LOW LEVEL MOISTURE MAY MOVE AS FAR WEST AS THE EASTERN MOUNTAINS...BUT NOT FURTHER WEST. AS A RESULT...CHANCES FOR SIGNIFICANT RAINFALL OVER THE CONTINENTAL DIVIDE REGION WILL BE LOW. .THURSDAY...UPPER RIDGE STARTS TO MOVE EASTWARD WITH A GENERAL DRYING AND WARMING TREND. GRIDS HAVE SOME ISOLATED POPS OVER THE MOUNTAINS AND PORTIONS OF THE PLAINS...MOSTLY FOR SOME RESIDUAL MOISTURE OVER THE REGION. --PGW-- && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 334 AM MDT FRI JUN 20 2014 VFR CONDITIONS EXPECTED AT THE TAF SITES THROUGH THE NEXT 24 HOURS WITH A GENERALLY LIGHT DIURNAL WIND REGIME. WILL SEE SOME CU BUILDUPS ACROSS THE EASTERN MTS THIS AFTERNOON...WITH ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE EAST OF KCOS AND KPUB DURING THE AFTERNOON AND EVENING HOURS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MW LONG TERM...PGW AVIATION...MW
AREA FORECAST DISCUSSION
NWS MIAMI FL
944 AM EDT FRI JUN 20 2014 .UPDATE... WEAK MID/UPPER LEVEL TROUGH OF LOW PRESSURE ALONG WITH A WEAK SURFACE TROUGH REMAIN NEARLY STATIONARY THIS MORNING ALONG THE EASTERN PENINSULA COAST. FORECAST MODELS ALL INDICATE THESE TROUGH BOUNDARIES WILL MOVE LITTLE THROUGH THE DAY. THE 12Z MFL SOUNDING SHOWS A SIMILAR STATE TO THE ATMOSPHERE AS 24 HOURS AGO WITH A VERY MOIST AND UNSTABLE ENVIRONMENT. THE PWAT IS AT 1.9 INCHES WITH THE MOST UNSTABLE CAPE SHOWING OVER 2000 J/KG ALONG WITH A LIGHT WESTERLY STEERING FLOW. THE MID LEVEL LAPSE RATES LIKE YESTERDAY ARE NOT TERRIBLY IMPRESSIVE SO WIDESPREAD SEVERE STORMS ARE NOT EXPECTED. HOWEVER, THE SKY IS STARTING OUT THIS MORNING NEARLY CLOUD FREE SO THERE WILL AGAIN BE ABUNDANT DIURNAL HEATING WHICH WILL SET THE STAGE FOR STRONG UPDRAFTS BY LATE THIS MORNING AS SURFACE TEMPERATURES REACH THE MID AND UPPER 80S. ALL OF THIS SAID, THE FORECAST APPEARS TO BE RIGHT ON TRACK WITH THE HIGHEST CHANCES ALONG THE EAST COAST WITH STRONG THUNDERSTORMS LIKELY AND THERE IS ALWAYS THE OUTSIDE CHANCE OF AN ISOLATED SEVERE STORM WITH THE PRIMARY CONCERN BEING THE STRONG WIND GUSTS. KOB && .PREV DISCUSSION... /ISSUED 801 AM EDT FRI JUN 20 2014/ AVIATION... WEAK LOW PRESSURE OVER FLORIDA WILL CONTINUE TO BRING UNSETTLED WEATHER TO THE AREA. ALSO, HIGH PRESSURE TO THE NORTHEAST HAS WEAKENED, WHICH IS ALLOWING FOR A MORE WESTERLY FLOW TODAY. THIS WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO THE ATLANTIC TAF SITES THIS AFTERNOON, ESPECIALLY ONCE THE SEA BREEZE IS ABLE TO DEVELOP. ALONG THE GULF COAST, WITH THE WESTERLY FLOW, THE GULF BREEZE WILL BE ENHANCED, KEEPING MOST OF THE CONVECTIVE ACTIVITY EAST OF KAPF. SO, WITH UNCERTAINTY AS TO THE TIMING AND THE EXACT LOCATION OF CONVECTIVE CELLS, HAVE ONLY VCTS IN THE TAFS THIS AFTERNOON FOR THE EASTERN TAF SITES. CONDITIONS SHOULD IMPROVE AFTER 00Z. PREV DISCUSSION... /ISSUED 348 AM EDT FRI JUN 20 2014/ DISCUSSION...A WEAK LOW IS CENTERED OFF THE COAST AT CAPE CANAVERAL. THIS IS LEADING TO A LIGHT MEAN WESTERLY STEERING FLOW ACROSS SOUTH FLORIDA. ANOTHER ACTIVE DAY OF TSTORMS IS EXPECTED INTERIOR TO THE EAST COAST METRO AREAS AS A DEVELOPING ATLANTIC SEA BREEZE THIS AFTERNOON BUMPS UP AGAINST THE OPPOSING MEAN WESTERLY WIND FLOW. MOISTURE AND INSTABILITY LOOKS MORE THAN SUFFICIENT TO GET THINGS GOING SO THREW OUT THE LOW GFS MOS POP NUMBERS WHICH LOOK WAY TOO LOW. SIDED WITH NAM MOS AND HRRR WHICH SHOWS ACTIVE CONVECTION FOCUSED EAST COAST METRO. LATEST HRRR REALLY FOCUSES ACTIVITY ACROSS THE FORT LAUDERDALE AND MIAMI METRO AREAS LATE THIS AFTERNOON...WITH LESS ACTIVITY AT THE PALM BEACHES. NAM12 THOUGH FOCUSES CONVECTION FROM THE LAKE TO THE PALM BEACHES. ALTHOUGH I`M CONFIDENT TSTORMS WILL FOCUS EAST COAST METRO, THE EXACT PLACEMENT OF CONVECTION IS UNCERTAIN, SO DID NOT GET FANCY AND PLACED LIKELY POPS UP AND DOWN THE SE FLORIDA COAST THIS AFTERNOON. MAIN CONCERN WILL BE LOCALLY HEAVY RAINFALL AND STRONG WIND GUSTS. LOCALIZED URBAN FLOODING WILL BE POSSIBLE WHERE THE STRONGEST STORMS HIT...ESPECIALLY IF THEY HIT ACROSS AREAS WHICH SAW HEAVY RAINFALL YESTERDAY. WILL HIGHLIGHT THESE POTENTIAL HAZARDS IN THE MORNING HAZARDOUS WEATHER OUTLOOK. A TYPICAL SUMMERTIME PATTERN IS EXPECTED OVER THE UPCOMING WEEKEND AND NEXT WEEK WITH SCATTERED AFTERNOON TSTORMS EXPECTED TO DEVELOP EACH DAY. NO MAJOR SYNOPTIC SCALE FEATURES OF NOTE. THE FOCUS OF STORMS THIS WEEKEND STILL LOOKS TO FAVOR THE EASTERN HALF OF THE AREA...THEN FAVORING INTERIOR AREAS MOST OF NEXT WEEK AS THE RIDGE BUILDS IN AND WE GET INTO MORE OF A SE WIND FLOW PATTERN. GFS AND ECMWF CONTINUE TO DIFFER WITH RESPECT TO MOISTURE NEXT WEEK WITH ECMWF DRYING THINGS OUT MORE SO THAN THE GFS. GFS DOES SEEM TOO STRONG WITH AN INVERTED TROUGH MOVING OUT OF THE CARIB. IT`S HAD A STRONG BIAS ALL SEASON...SO NOT BUYING THIS. HAVE GONE WITH CHANCE POPS MOST LOCALES EACH DAY THROUGH NEXT WEEK...AS SEE NO REASON TO DEVIATE FROM THIS. /GREGORIA MARINE...LIGHT WINDS WILL PREVAIL LEADING TO A CONTINUATION OF LOW SEAS. MAIN HAZARD WILL BE LIGHTNING AND LOCALLY GUSTY WINDS IN AND NEAR TSTORMS. /GREGORIA && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 73 89 76 / 70 40 50 20 FORT LAUDERDALE 87 75 88 78 / 70 40 50 20 MIAMI 88 74 91 76 / 70 40 50 20 NAPLES 88 73 88 74 / 20 20 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
801 AM EDT FRI JUN 20 2014 .AVIATION... WEAK LOW PRESSURE OVER FLORIDA WILL CONTINUE TO BRING UNSETTLED WEATHER TO THE AREA. ALSO, HIGH PRESSURE TO THE NORTHEAST HAS WEAKENED, WHICH IS ALLOWING FOR A MORE WESTERLY FLOW TODAY. THIS WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO THE ATLANTIC TAF SITES THIS AFTERNOON, ESPECIALLY ONCE THE SEA BREEZE IS ABLE TO DEVELOP. ALONG THE GULF COAST, WITH THE WESTERLY FLOW, THE GULF BREEZE WILL BE ENHANCED, KEEPING MOST OF THE CONVECTIVE ACTIVITY EAST OF KAPF. SO, WITH UNCERTAINTY AS TO THE TIMING AND THE EXACT LOCATION OF CONVECTIVE CELLS, HAVE ONLY VCTS IN THE TAFS THIS AFTERNOON FOR THE EASTERN TAF SITES. CONDITIONS SHOULD IMPROVE AFTER 00Z. && .PREV DISCUSSION... /ISSUED 348 AM EDT FRI JUN 20 2014/ DISCUSSION...A WEAK LOW IS CENTERED OFF THE COAST AT CAPE CANAVERAL. THIS IS LEADING TO A LIGHT MEAN WESTERLY STEERING FLOW ACROSS SOUTH FLORIDA. ANOTHER ACTIVE DAY OF TSTORMS IS EXPECTED INTERIOR TO THE EAST COAST METRO AREAS AS A DEVELOPING ATLANTIC SEA BREEZE THIS AFTERNOON BUMPS UP AGAINST THE OPPOSING MEAN WESTERLY WIND FLOW. MOISTURE AND INSTABILITY LOOKS MORE THAN SUFFICIENT TO GET THINGS GOING SO THREW OUT THE LOW GFS MOS POP NUMBERS WHICH LOOK WAY TOO LOW. SIDED WITH NAM MOS AND HRRR WHICH SHOWS ACTIVE CONVECTION FOCUSED EAST COAST METRO. LATEST HRRR REALLY FOCUSES ACTIVITY ACROSS THE FORT LAUDERDALE AND MIAMI METRO AREAS LATE THIS AFTERNOON...WITH LESS ACTIVITY AT THE PALM BEACHES. NAM12 THOUGH FOCUSES CONVECTION FROM THE LAKE TO THE PALM BEACHES. ALTHOUGH I`M CONFIDENT TSTORMS WILL FOCUS EAST COAST METRO, THE EXACT PLACEMENT OF CONVECTION IS UNCERTAIN, SO DID NOT GET FANCY AND PLACED LIKELY POPS UP AND DOWN THE SE FLORIDA COAST THIS AFTERNOON. MAIN CONCERN WILL BE LOCALLY HEAVY RAINFALL AND STRONG WIND GUSTS. LOCALIZED URBAN FLOODING WILL BE POSSIBLE WHERE THE STRONGEST STORMS HIT...ESPECIALLY IF THEY HIT ACROSS AREAS WHICH SAW HEAVY RAINFALL YESTERDAY. WILL HIGHLIGHT THESE POTENTIAL HAZARDS IN THE MORNING HAZARDOUS WEATHER OUTLOOK. A TYPICAL SUMMERTIME PATTERN IS EXPECTED OVER THE UPCOMING WEEKEND AND NEXT WEEK WITH SCATTERED AFTERNOON TSTORMS EXPECTED TO DEVELOP EACH DAY. NO MAJOR SYNOPTIC SCALE FEATURES OF NOTE. THE FOCUS OF STORMS THIS WEEKEND STILL LOOKS TO FAVOR THE EASTERN HALF OF THE AREA...THEN FAVORING INTERIOR AREAS MOST OF NEXT WEEK AS THE RIDGE BUILDS IN AND WE GET INTO MORE OF A SE WIND FLOW PATTERN. GFS AND ECMWF CONTINUE TO DIFFER WITH RESPECT TO MOISTURE NEXT WEEK WITH ECMWF DRYING THINGS OUT MORE SO THAN THE GFS. GFS DOES SEEM TOO STRONG WITH AN INVERTED TROUGH MOVING OUT OF THE CARIB. IT`S HAD A STRONG BIAS ALL SEASON...SO NOT BUYING THIS. HAVE GONE WITH CHANCE POPS MOST LOCALES EACH DAY THROUGH NEXT WEEK...AS SEE NO REASON TO DEVIATE FROM THIS. /GREGORIA MARINE...LIGHT WINDS WILL PREVAIL LEADING TO A CONTINUATION OF LOW SEAS. MAIN HAZARD WILL BE LIGHTNING AND LOCALLY GUSTY WINDS IN AND NEAR TSTORMS. /GREGORIA && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 73 89 76 / 70 40 50 20 FORT LAUDERDALE 87 75 88 78 / 70 40 50 20 MIAMI 88 74 91 76 / 70 40 50 20 NAPLES 88 73 88 74 / 20 20 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...57/DG LONG TERM....57/DG AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1127 AM EDT FRI JUN 20 2014 .SYNOPSIS... A SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH SUNDAY AS UPPER LEVEL RIDGING SLIDES WESTWARD. ABOVE NORMAL TEMPERATURES AND THE CHANCE FOR THUNDERSTORMS WILL CONTINUE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THIS AFTERNOON...THE AIRMASS WILL BECOME MODERATELY UNSTABLE WITH LIFTED INDEX FORECAST TO BE -4C TO -6C AND CONTINUED WEAK WIND SHEAR. LINGERING OUTFLOW BOUNDARIES FROM YESTERDAY MAY HELP TO FOCUS CONVECTION THIS AFTERNOON. POSSIBLE WEAK SHORTWAVE ENERGY MOVING OUT OF THE MOUNTAINS COULD AID IN CONVECTIVE DEVELOPMENT IN THE NORTHERN HALF OF THE FORECAST AREA. PWAT VALUES WILL BE AROUND 1.7 INCHES. MAX TEMPS IN THE MID-UPPER 90S WITH 20+ DEWPOINT DEPRESSIONS...SO ANY STORMS THAT DEVELOP COULD BECOME SEVERE WITH A DAMAGING WIND THREAT. HAIL LOOKS TO BE LESS OF A THREAT WITH FREEZING LEVEL AROUND 14.2 KFT AND 500MB TEMP AROUND -8C. LOCAL MODEL ALONG WITH THE HRRR SHOWS SCATTERED CONVECTION DEVELOPING LATE IN THE AFTERNOON...LASTING WELL INTO THE EVENING. WILL GO WITH 20 TO 40 PERCENT POPS FOR THE LATE AFTERNOON AND EVENING. TONIGHT...CONVECTION WILL DIMINISH BY MIDNIGHT. HOWEVER...THE AIRMASS WILL REMAIN UNSTABLE WITH PERHAPS A WEAK SHORT WAVE. EVEN THOUGH CANNOT TOTALLY RULE OUT A SHOWER OR THUNDERSTORM OVERNIGHT...ELECTED TO GO WITH MAINLY DRY FORECAST LATE TONIGHT THROUGH EARLY MORNING. KEPT OVERNIGHT LOWS IN THE LOWER 70S...PER PERSISTENCE. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... A WEAK LOW WILL FORM IN THE MID ATLANTIC AREA ON SATURDAY...ALONG THE REMAINS OF THE FRONT AND PUSH SOUTHWARD INTO THE FORECAST AREA SATURDAY NIGHT. CYCLONIC FLOW WILL CONTINUE ALOFT...ALLOWING SHORT WAVE TO MOVE ACROSS THE COAST STATES. WITH MAX TEMPERATURES CONTINUING IN THE MID TO UPPER 90S...HIGH INSTABILITY AND PWAT VALUES RISING TO 1.8 TO 1.9 INCHES THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE. LARGE HAIL THREAT WILL BE LOW AS FREEZING AND WET BULB ZERO LEVELS WILL BE ABOVE 14 KFT AND 12 KFT RESPECTIVELY. OVERNIGHT LOWS WILL BE IN THE LOWER 70S. && .LONG TERM /SUNDAY THROUGH THURSDAY/... MODELS ARE IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME MINOR DIFFERENCES IN TIMING AND INTENSITY. WEAK LOW PRESSURE WILL SLIDE OFFSHORE OF THE MID ATLANTIC STATES ON SUNDAY WITH THE REMAINS OF THE FRONT PUSHING THROUGH THE FORECAST AREA ON SUNDAY THEN STALLING JUST SOUTH OF THE AREA SUNDAY NIGHT THROUGH EARLY TUESDAY. THE FRONT WILL MEANDER NORTHWARD ON TUESDAY AS THE NEXT LOW PRESSURE SYSTEM CROSSES THE GREAT LAKES. AS THE LOW TRACKS FURTHER EASTWARD WEDNESDAY AND THURSDAY THE COLD FRONT WILL CROSS INTO THE EASTERN US THEN STALL ACROSS THE AREA. THIS SERIES OF FEATURES WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGH THE LONG TERM. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL WITH DAYTIME HIGHS IN THE LOWER TO MIDDLE 90S AND OVERNIGHT LOWS IN THE LOWER 70S. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... GENERALLY VFR CONDITIONS EXPECTED THROUGH THE MAJORITY OF THE PERIOD. MOSTLY SUNNY SKIES WILL GIVE WAY TO AFTERNOON CUMULUS CLOUDS. WINDS WILL GENERALLY REMAIN LIGHT FROM THE WEST TO NORTHWEST LATE MORNING AROUND 5 TO 8 MPH. A THERMAL TROUGH WILL DEVELOP FROM STRONG SURFACE HEATING AND COULD PROVIDE A FOCUS FOR SOME AFTERNOON CONVECTION. CONVECTION SHOULD BE ISOLATED TO SCATTERED AND WILL NOT INCLUDE IN THE FORECAST AT THIS TIME. AFTERNOON CONVECTION MAY RESULT IN DEBRIS CLOUDS THIS EVENING WHICH COULD INHIBIT FOG DEVELOPMENT SATURDAY MORNING. EXTENDED AVIATION OUTLOOK...EARLY MORNING MVFR/IFR FOG POSSIBLE EACH DAY...MAINLY AT FOG PRONE SITES AGS/OGB. SCATTERED DIURNAL THUNDERSTORMS EXPECTED EACH AFTERNOON AND EVENING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1043 AM EDT FRI JUN 20 2014 .UPDATE... ISSUED AT 1039 AM EDT FRI JUN 20 2014 ISOLATED SHOWERS AND A FEW RUMBLES OF THUNDER CONTINUE ACROSS EASTERN KY. LIKE PREVIOUS FORECAST...EXPECT THINGS TO START FIRING UP TO MORE SCATTERED COVERAGE DURING THE AFTERNOON HOURS AS WE START TO HEAT UP. UPDATED THE SKY GRIDS FOR THE NEXT FEW HOURS TO BETTER MATCH THE CURRENT CONDITIONS...WITH COVERAGE EXPECTED TO INCREASE THROUGHOUT THE AFTERNOON. LEFT POPS AS IS...WITH ISOLATED TO SCATTERED CHANCES OVER THE NEXT FEW HOURS. ALSO INCLUDED THE LATEST OBSERVATIONAL DATA IN THE CURRENT FORECAST TO MAKE SURE THE TEMPS...DEW POINTS...AND WINDS FORECASTS ARE REFLECTING THE CURRENT DATA. UPDATE ISSUED AT 750 AM EDT FRI JUN 20 2014 HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT RADAR AND SATELLITE TRENDS. SOME SHOWERS AND THUNDERSTORMS HAVE ALREADY DEVELOPED THIS MORNING...THOUGH THEY SHOULD INCREASE IN COVERAGE AND INTENSITY BY EARLY IN THE AFTERNOON. THE THREAT FOR SHOWERS AND THUNDERSTORMS SHOULD LINGER THROUGH THE ENTIRE DAY. OUTSIDE OF SHOWERS AND THUNDERSTORMS WARM AND HUMID WEATHER IS ANTICIPATED. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 359 AM EDT FRI JUN 20 2014 THE REGION REMAINS IN THE WARM SECTOR SOUTH OF A FRONTAL ZONE EXTENDING FROM THE CAROLINAS NORTHWEST TOWARD LOW PRESSURE OVER THE NORTHERN PLAINS AND UPPER MS VALLEY REGION. THE OVERALL FLOW ACROSS THE CONUS ATTM IS RATHER ZONAL IN NATURE WITH MID LEVEL RIDGING CENTERED OVER THE LOWER MS RIVER VALLEY...WITH LOW AMPLITUDE RIDGING NORTH TOWARD THE OH RIVER VALLEY. WELL TO THE NORTHEAST OF EAST KY... A MID LEVEL LOW AND ASSOCIATED SFC LOW THAT HAS HELPED TO PUSH THE BOUNDARY SOUTH ALONG THE EASTERN SEABOARD TO THE CAROLINAS REMAINS PLACE WHILE A CLOSED LOW IS WORKING ACROSS THE NORTHERN ROCKIES TOWARD THE NORTHERN PLAINS REGION ALONG US/CANADIAN BORDER. MEANWHILE...A SHORTWAVE TROUGH IS SLOWLY WORKING FROM THE PLAINS INTO THE MID MS AND LOWER OH VALLEY REGION. THE SHORTWAVE TROUGH WILL WORK INTO THE LOWER OH VALLEY REGION OVER THE NEXT FEW HOURS AND IS POISED TO MOVE ACROSS EASTERN KY AND INTO THE APPALACHIAN REGION LATE THIS AFTERNOON AND INTO THIS EVENING. AS THIS SHORTWAVE APPROACHES A SFC WAVE SHOULD DEVELOP AND WORK EAST SOUTHEAST ALONG THIS NEARLY STATIONARY BOUNDARY AND CROSS THE APPALACHIANS TONIGHT. THIS LOW SHOULD REACH THE EASTERN SEABOARD ON SATURDAY WITH THE TAILING COLD FRONT GRADUALLY SAGGING INTO EASTERN KY AND CROSSING MUCH OF THE AREA BY THE END OF THE PERIOD. THROUGH SHORTLY AFTER DAWN...PATCHY RIVER VALLEY FOG SHOULD REMAIN IN PLACE...WITH THIS FOG GRADUALLY BEGINNING TO LIFT AND POSSIBLY AFFECTING A FEW RIDGETOP LOCATIONS NEAR LOCATIONS THAT EXPERIENCED THE HEAVIER RAINFALL ON THU AND THU EVENING. THIS FOG SHOULD LIFT AND DISSIPATE SHORTLY AFTER DAWN. ALSO...THE NEAR TERM MODELS SUCH AS RECENT HRRR RUNS AND RECENT RAP RUNS HAVE SOME CONVECTION DEVELOPING NEAR SUNRISE BETWEEN JKL AND LOZ OR FROM ESTILL COUNTY SOUTH TO BELL COUNTY AND THEN MOVING EAST TO NEAR THE KY 15 CORRIDOR FROM JKL SOUTH TO THE VA BORDER AND THEN INTO FAR SOUTHEAST KY BEFORE NOON. THE 6Z NAM ALSO HAS SOME CONVECTION...BUT IS FURTHER EAST NEAR TO THE VA BORDER ACROSS THE BIG SANDY REGION. HOWEVER...EVEN IF THERE IS SOME MORNING CONVECTION...JUST A FEW HOURS OF THE STRONG JUNE SUNSHINE SHOULD BRING MID TO UPPER 80S SFC TEMPS WITH SFC DEWPOINTS IN THE MID 60S TO NEAR 70 DEGREE RANGE TO YIELD CAPE OF 2000 J/KG OR MORE BY MID TO LATE AFTERNOON. LAPSE RATES IN THE MID LEVELS WILL NOT BE PARTICULARLY STRONG AND RATHER WEAK SHEAR SHOULD LIMIT STORM ORGANIZATION. HOWEVER... A FEW CELLS...POSSIBLY SECOND AND THIRD GENERATION CELLS THAT DEVELOP NEAR OUTFLOW INTERSECTIONS COULD BECOME STRONG TO LOCALLY SEVERE AND PRODUCE STRONG TO LOCALLY DAMAGING WIND GUSTS. SPC HAS PLACED THE REGION IN A SEE TEXT AREA WITH 5 PERCENT PROBABILITIES FOR SEVERE THUNDERSTORM CRITERIA WINDS AND THIS APPEARS REASONABLE. THE MAIN THREAT FROM STORMS LATER TODAY AND TONIGHT MAY END UP BEING LOCALLY HEAVY RAINFALL RATES AS PW IS EXPECTED TO BE AT OR ABOVE THE 75TH PERCENTILE. THE PRESENCE OF THE SAGGING BOUNDARY AND THE POTENTIAL FOR CONVECTION TO TRAIN IN SOME AREAS AS THE STEERING FLOW MAY BECOME NEARLY PARALLEL TO THE SAGGING BOUNDARY OR OUTFLOWS COULD LEAD TO A LOCALIZED THREAT OF FLOODING. UNCERTAINTY REMAINS IN THE DETAILS AS FAR AS TIMING AND LOCATION. IN GENERAL...IT APPEARS THAT AS THE SHORTWAVE WORKS INTO EASTERN KY AND THE APPALACHIANS...CONVECTION SHOULD BE MOST WIDESPREAD DURING THE LATE AFTERNOON INTO LATE EVENING. THE HWO HAS BEEN ADJUSTED ACCORDINGLY FOR ALL OF THESE THREATS. THE THREAT OF SOME CONVECTION WILL LINGER EVEN INTO THE DAY ON SATURDAY AND WILL PROBABLY FEATURE A DIURNAL UPTICK IN CONVERGE. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 406 AM EDT FRI JUN 20 2014 THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A TYPICAL SUMMER PATTERN IN PLACE. A NEAR ZONAL UPPER LEVEL FLOW CONTINUES BUT WITH THE USUAL MID LEVEL RIDGE IN THE SOUTHEAST NOW SHIFTED TOWARDS THE WESTERN GULF OF MEXICO. BRIEF RIDGING WILL KEEP PRECIP MAINLY DIURNALLY DRIVEN AS THE BULK OF THE SUPPORT EXITS EASTERN KENTUCKY SATURDAY NIGHT...LEAVING ONLY SLIGHT CHANCE PRECIP INTO THE DAY ON SUNDAY WITH THE MAX HEATING. BY MONDAY...A SIGNIFICANT SHORTWAVE MOVES ACROSS THE PLAINS AND INTO THE OH VALLEY. THIS WAVE WILL BE THE FOCUS OF ACTIVE WEATHER THROUGH THE MID PORTION OF THE EXTENDED. THE MENTIONED WAVE PUSHES THROUGH ON MONDAY NIGHT AND TUESDAY PUSHING A SURFACE COLD FRONT THROUGH. THIS FORCING AND THE WAVE MOVING THROUGH WILL PROVIDE THE BEST CHANCE OF PRECIP ON TUESDAY AND INTO TUESDAY NIGHT. THE EURO HINTS AT THE FRONT STALLING AND BECOMING AN EAST WEST STATIONARY BOUNDARY ALONG SOUTHERN KY BY THE WED AND THU TIME FRAME. THIS BECOMES AN POINT OF DEVELOPING CONVECTION THROUGH THE LAST COUPLE DAYS OF THE EXTENDED. THE CHANCES WITH THIS SET UP BECOME DIURNALLY DRIVEN WITH THE HEATING OF THE DAY. THE LACK OF CONTINUITY OF GUIDANCE AND NEED TO STAY CONSISTENT WITH THE NEIGHBORING OFFICES...LEAD TO KEEPING VALUES CLOSER TO THE ALL MODEL BLEND SOLUTION. THE MONDAY THROUGH TUESDAY NIGHT PERIOD REMAINS A PERIOD TO WATCH WITH THE STRONG WAVE MOVING THROUGH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 755 AM EDT FRI JUN 20 2014 ANY LINGERING VALLEY FOG SHOULD LIFT AND DISSIPATE BY 13Z. SOME SHRA/TSRA CANNOT BE RULED OUT AT ANY POINT...BUT CHANCES APPEAR GREATEST CLOSER TO WHEN AN UPPER LEVEL DISTURBANCE NEARS THE REGION...GENERALLY AFTER 19Z OR 20Z THROUGH ABOUT 4Z. CONFIDENCE TIMING IS UNCERTAIN...AND ONLY VCTS HAS BEEN USED IN TAFS AT THIS POINT. SOME FOG MAY FORM LATE IN THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...JP LONG TERM...SHALLENBERGER AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
808 AM EDT FRI JUN 20 2014 .UPDATE... ISSUED AT 750 AM EDT FRI JUN 20 2014 HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT RADAR AND SATELLITE TRENDS. SOME SHOWERS AND THUNDERSTORMS HAVE ALREADY DEVELOPED THIS MORNING...THOUGH THEY SHOULD INCREASE IN COVERAGE AND INTENSITY BY EARLY IN THE AFTERNOON. THE THREAT FOR SHOWERS AND THUNDERSTORMS SHOULD LINGER THROUGH THE ENTIRE DAY. OUTSIDE OF SHOWERS AND THUNDERSTORMS WARM AND HUMID WEATHER IS ANTICIPATED. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 359 AM EDT FRI JUN 20 2014 THE REGION REMAINS IN THE WARM SECTOR SOUTH OF A FRONTAL ZONE EXTENDING FROM THE CAROLINAS NORTHWEST TOWARD LOW PRESSURE OVER THE NORTHERN PLAINS AND UPPER MS VALLEY REGION. THE OVERALL FLOW ACROSS THE CONUS ATTM IS RATHER ZONAL IN NATURE WITH MID LEVEL RIDGING CENTERED OVER THE LOWER MS RIVER VALLEY...WITH LOW AMPLITUDE RIDGING NORTH TOWARD THE OH RIVER VALLEY. WELL TO THE NORTHEAST OF EAST KY... A MID LEVEL LOW AND ASSOCIATED SFC LOW THAT HAS HELPED TO PUSH THE BOUNDARY SOUTH ALONG THE EASTERN SEABOARD TO THE CAROLINAS REMAINS PLACE WHILE A CLOSED LOW IS WORKING ACROSS THE NORTHERN ROCKIES TOWARD THE NORTHERN PLAINS REGION ALONG US/CANADIAN BORDER. MEANWHILE...A SHORTWAVE TROUGH IS SLOWLY WORKING FROM THE PLAINS INTO THE MID MS AND LOWER OH VALLEY REGION. THE SHORTWAVE TROUGH WILL WORK INTO THE LOWER OH VALLEY REGION OVER THE NEXT FEW HOURS AND IS POISED TO MOVE ACROSS EASTERN KY AND INTO THE APPALACHIAN REGION LATE THIS AFTERNOON AND INTO THIS EVENING. AS THIS SHORTWAVE APPROACHES A SFC WAVE SHOULD DEVELOP AND WORK EAST SOUTHEAST ALONG THIS NEARLY STATIONARY BOUNDARY AND CROSS THE APPALACHIANS TONIGHT. THIS LOW SHOULD REACH THE EASTERN SEABOARD ON SATURDAY WITH THE TAILING COLD FRONT GRADUALLY SAGGING INTO EASTERN KY AND CROSSING MUCH OF THE AREA BY THE END OF THE PERIOD. THROUGH SHORTLY AFTER DAWN...PATCHY RIVER VALLEY FOG SHOULD REMAIN IN PLACE...WITH THIS FOG GRADUALLY BEGINNING TO LIFT AND POSSIBLY AFFECTING A FEW RIDGETOP LOCATIONS NEAR LOCATIONS THAT EXPERIENCED THE HEAVIER RAINFALL ON THU AND THU EVENING. THIS FOG SHOULD LIFT AND DISSIPATE SHORTLY AFTER DAWN. ALSO...THE NEAR TERM MODELS SUCH AS RECENT HRRR RUNS AND RECENT RAP RUNS HAVE SOME CONVECTION DEVELOPING NEAR SUNRISE BETWEEN JKL AND LOZ OR FROM ESTILL COUNTY SOUTH TO BELL COUNTY AND THEN MOVING EAST TO NEAR THE KY 15 CORRIDOR FROM JKL SOUTH TO THE VA BORDER AND THEN INTO FAR SOUTHEAST KY BEFORE NOON. THE 6Z NAM ALSO HAS SOME CONVECTION...BUT IS FURTHER EAST NEAR TO THE VA BORDER ACROSS THE BIG SANDY REGION. HOWEVER...EVEN IF THERE IS SOME MORNING CONVECTION...JUST A FEW HOURS OF THE STRONG JUNE SUNSHINE SHOULD BRING MID TO UPPER 80S SFC TEMPS WITH SFC DEWPOINTS IN THE MID 60S TO NEAR 70 DEGREE RANGE TO YIELD CAPE OF 2000 J/KG OR MORE BY MID TO LATE AFTERNOON. LAPSE RATES IN THE MID LEVELS WILL NOT BE PARTICULARLY STRONG AND RATHER WEAK SHEAR SHOULD LIMIT STORM ORGANIZATION. HOWEVER... A FEW CELLS...POSSIBLY SECOND AND THIRD GENERATION CELLS THAT DEVELOP NEAR OUTFLOW INTERSECTIONS COULD BECOME STRONG TO LOCALLY SEVERE AND PRODUCE STRONG TO LOCALLY DAMAGING WIND GUSTS. SPC HAS PLACED THE REGION IN A SEE TEXT AREA WITH 5 PERCENT PROBABILITIES FOR SEVERE THUNDERSTORM CRITERIA WINDS AND THIS APPEARS REASONABLE. THE MAIN THREAT FROM STORMS LATER TODAY AND TONIGHT MAY END UP BEING LOCALLY HEAVY RAINFALL RATES AS PW IS EXPECTED TO BE AT OR ABOVE THE 75TH PERCENTILE. THE PRESENCE OF THE SAGGING BOUNDARY AND THE POTENTIAL FOR CONVECTION TO TRAIN IN SOME AREAS AS THE STEERING FLOW MAY BECOME NEARLY PARALLEL TO THE SAGGING BOUNDARY OR OUTFLOWS COULD LEAD TO A LOCALIZED THREAT OF FLOODING. UNCERTAINTY REMAINS IN THE DETAILS AS FAR AS TIMING AND LOCATION. IN GENERAL...IT APPEARS THAT AS THE SHORTWAVE WORKS INTO EASTERN KY AND THE APPALACHIANS...CONVECTION SHOULD BE MOST WIDESPREAD DURING THE LATE AFTERNOON INTO LATE EVENING. THE HWO HAS BEEN ADJUSTED ACCORDINGLY FOR ALL OF THESE THREATS. THE THREAT OF SOME CONVECTION WILL LINGER EVEN INTO THE DAY ON SATURDAY AND WILL PROBABLY FEATURE A DIURNAL UPTICK IN CONVERGE. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 406 AM EDT FRI JUN 20 2014 THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A TYPICAL SUMMER PATTERN IN PLACE. A NEAR ZONAL UPPER LEVEL FLOW CONTINUES BUT WITH THE USUAL MID LEVEL RIDGE IN THE SOUTHEAST NOW SHIFTED TOWARDS THE WESTERN GULF OF MEXICO. BRIEF RIDGING WILL KEEP PRECIP MAINLY DIURNALLY DRIVEN AS THE BULK OF THE SUPPORT EXITS EASTERN KENTUCKY SATURDAY NIGHT...LEAVING ONLY SLIGHT CHANCE PRECIP INTO THE DAY ON SUNDAY WITH THE MAX HEATING. BY MONDAY...A SIGNIFICANT SHORTWAVE MOVES ACROSS THE PLAINS AND INTO THE OH VALLEY. THIS WAVE WILL BE THE FOCUS OF ACTIVE WEATHER THROUGH THE MID PORTION OF THE EXTENDED. THE MENTIONED WAVE PUSHES THROUGH ON MONDAY NIGHT AND TUESDAY PUSHING A SURFACE COLD FRONT THROUGH. THIS FORCING AND THE WAVE MOVING THROUGH WILL PROVIDE THE BEST CHANCE OF PRECIP ON TUESDAY AND INTO TUESDAY NIGHT. THE EURO HINTS AT THE FRONT STALLING AND BECOMING AN EAST WEST STATIONARY BOUNDARY ALONG SOUTHERN KY BY THE WED AND THU TIME FRAME. THIS BECOMES AN POINT OF DEVELOPING CONVECTION THROUGH THE LAST COUPLE DAYS OF THE EXTENDED. THE CHANCES WITH THIS SET UP BECOME DIURNALLY DRIVEN WITH THE HEATING OF THE DAY. THE LACK OF CONTINUITY OF GUIDANCE AND NEED TO STAY CONSISTENT WITH THE NEIGHBORING OFFICES...LEAD TO KEEPING VALUES CLOSER TO THE ALL MODEL BLEND SOLUTION. THE MONDAY THROUGH TUESDAY NIGHT PERIOD REMAINS A PERIOD TO WATCH WITH THE STRONG WAVE MOVING THROUGH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 755 AM EDT FRI JUN 20 2014 ANY LINGERING VALLEY FOG SHOULD LIFT AND DISSIPATE BY 13Z. SOME SHRA/TSRA CANNOT BE RULED OUT AT ANY POINT...BUT CHANCES APPEAR GREATEST CLOSER TO WHEN AN UPPER LEVEL DISTURBANCE NEARS THE REGION...GENERALLY AFTER 19Z OR 20Z THROUGH ABOUT 4Z. CONFIDENCE TIMING IS UNCERTAIN...AND ONLY VCTS HAS BEEN USED IN TAFS AT THIS POINT. SOME FOG MAY FORM LATE IN THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...JP LONG TERM...SHALLENBERGER AVIATION...JP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
556 AM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT FRI JUN 20 2014 FIRST CONCERNS IS DENSE FOG ADV ACROSS MPX CWA. SECONDARY CONCERN IS ISOLD/SCT CONVECTION ALONG AN INSTABILITY AXIS MOVING ACROSS MN THIS AFTN. PLENTY OF RAINFALL OVER THE LAST 24 HRS FOR BOUNDARY LAYER TO SATURATE. HOWEVER...BOUNDARY LAYER WINDS INCREASED SLIGHTLY AFT MIDNIGHT ALLOWING FOR MAINLY LOW STRATUS AND PATCHY DENSE FOG ACROSS SC MN...BUT THE MAJORITY OF MPX CWA HAD PATCHY FOG WITH LOCALIZED DENSE FOG WHERE CIGS DROPPED TO 100-200`. BASED ON CURRENT VIS/FOG SATELLITE IMAGERY AND BOUNDARY LAYER WINDS ARND 5-10 KTS ANTICIPATE THAT THE DENSE FOG ADV WILL BE CANCELLED EARLY...PROBABLY BEFORE SUNRISE. WILL MONITOR FOR ANY NEW DEVELOPMENT ACROSS SC/EC MN FOR CIGS/VSBYS DROPPING LOWER...BUT THIS IS NOT EXPECTED TO CAUSE WIDESPREAD DENSE FOG...ONLY PATCHY DENSE FOG. A COUPLE OF ITEMS TO NOTE EARLY THIS MORNING FOR THE POTENTIAL OF CONVECTION THIS AFTN. FIRST...A WEAK SHRTWV ROTATING ARND THE SOUTHERN PART OF THE MAIN UPPER LOW ACROSS SOUTH CENTRAL CANADA WILL LIKELY PROVIDE SOME LIFT LATER THIS AFTN ACROSS MN. RUC DOES SHOW 85/92H WINDS BECOMING MORE SSW/SW THIS AFTN ACROSS NE/SD WHICH WILL PULL RESIDUAL MOISTURE ACROSS KS/CO NE INTO SW MN DURING THE AFTN. MLCAPES AND MLCIN REFLECT THE CHC/S THIS AFTN IN A THIN BAND FROM SW TO CENTRAL MN. DUE TO WEAK SFC CONVERGENCE AND GREATER SHRTWV STRENGTH ACROSS NORTHERN MN...ONLY ISOLD/SCT SHRA/TSRA WILL BE POSSIBLE. 20-30% SEEMS REASONABLE AT THIS TIME. LATER SHIFTS WILL NEED TO MONITOR FOR HIGHER MOISTURE ADVECTING NE ACROSS S MN. THE SAME SW WINDS IN THE FIRST 5K ACROSS SD AND INTO WC MN THIS AFTN MAY CAUSE ENOUGH MIXING TO HAVE TEMPS RISE INTO THE LOWER 90S. BUT BASED ON THE WET SOIL CONDS AND DEW PTS IN THE 50S/60S...AM LEANING TOWARD MID TO UPPER 80S AT THIS TIME. TONIGHT WILL LIKELY SEE THE CONVECTION DECREASING RAPIDLY AFT SUNSET WITH MOST OF THE ACTION SOUTH OF THE MN AS THE LLJ DEVELOPS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 347 AM CDT FRI JUN 20 2014 THERE COULD BE AN ONGOING MCS IN NORTHEAST NE OR NORTHERN IA COME 12Z SATURDAY MORNING WITH THE AFOREMENTIONED INCREASING LLJ...BUT THE 850-300MB WINDS AND THICKNESS PATTERN SUGGEST ANY ORGANIZED /OR UNORGANIZED CONVECTION FOR THAT MATTER/ SHOULD TRACK E-SE WITH TIME AND REMAIN SOUTH OF THE FORECAST AREA THROUGH THE MORNING HOURS. EVEN MOST OF THE CLOUD DEBRIS SHOULD BE CARRIED DOWNSTREAM TO THE EAST. THE NAM/GFS/ECMWF ALL SEEM TO BE DEPICTING A WEAK TROUGH IN WESTERN WI AND LIGHT QPF. THE SOUNDINGS ARE FAIRLY DRY ON SATURDAY AND THERE ISN`T A CLEAR TRIGGER OUTSIDE OF PERHAPS A WEAK MID LEVEL WAVE IN IA. THERE IS MODEST ELEVATED INSTABILITY AND EVEN THE ECMWF DOES HINT AT CONVECTIVE INITIATION...BUT THE SHOWER/THUNDER CHANCES LOOK BETTER SOUTH AND EAST OF THE FORECAST AREA. SUNDAY IS PERHAPS A LITTLE MORE INTERESTING AND SUGGESTS A NEED FOR SLIGHTLY HIGHER POPS AS AN ADVANCING SURFACE BOUNDARY TRIES TO MAKE IT ACROSS MINNESOTA DURING THE DAY WITH A SHORTWAVE APPROACHING FROM THE CENTRAL PLAINS. ALTHOUGH PERHAPS A LITTLE OVERDONE WITH SURFACE DEWPOINTS...BOTH THE NAM-GFS HAVE LARGE MUCAPE VALUES OF 3000-5000 J/KG IN SOUTHERN MINNESOTA. THE SHEAR PROFILE IS WEAK...WHICH WILL SUPPRESS THE THREAT FOR SEVERE WEATHER. THERE IS ALSO UNCERTAINTY AS TO HOW MUCH CONVECTION THERE WILL BE...BUT GIVEN THE LARGE AMOUNT OF INSTABILITY...PULSE STORMS AND SMALL MULTICELL CLUSTERS COULD STILL POSE A MARGINAL SEVERE THREAT IF EVERYTHING PANS OUT. THE BEST CHANCE FOR MORE WIDESPREAD RAIN IN THE AVAILABLE MODEL GUIDANCE IS MONDAY AFTERNOON INTO EARLY TUESDAY MORNING WITH A DEVELOPING SURFACE CYCLONE TRACKING OUT OF THE SOUTHERN PLAINS AND DEEPENING WITH TIME AS IT HEADS TOWARD IA/WI. THERE IS A BIT MORE CONFIDENCE IN PRECIP AT LEAST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA BECAUSE THE GFS/ECMWF SOLUTIONS HAVE SETTLED DOWN OVER THE PAST 3-4 MODEL CYCLES. PREVIOUS RUNS THIS WEEK WERE ALL OVER THE PLACE WITH PLACEMENT AND TIMING. OTHERWISE WE`LL REMAIN IN A FAIRLY INNOCUOUS /AT LEAST COMPARED TO THE HEAVY RAIN PATTERN WE`VE BEEN IN RECENTLY/ WESTERLY FLOW THROUGH NEXT WEEK WITH NO BIG SYSTEMS...SEVERE WEATHER OUTBREAKS...BIG TEMPERATURES SWINGS...ETC. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 540 AM CDT FRI JUN 20 2014 LIFR CIGS ARE COMMOM ACROSS A LARGE AREA OF MPX CWA THIS MORNING...BUT THE MAIN CONCERN IS THE DEPTH OF THE CLDS WHICH WILL TRANSLATE TO A FAST BURN OFF...OR LINGER INTO THE LATE MORNING AS CURRENT BOUNDARY LAYER WINDS ARE WEAK. CONFIDENCE ACROSS SW/WC MN WHERE THE DEPTH IS MUCH SHALLOWER IS HIGHER...AND THE BURN OFF SHOULD BE QUICK OR WITHIN AN HR OR TWO. FURTHER TO THE EAST...CONFIDENCE IS LOW AS ANOTHER LAYER ABV THE LOW STRATUS WILL LIKELY LINGER FOR AN HR OR TWO. KRNH/KEAU WILL LIKELY SEE LIFR/IFR CIGS HOLDING UNTIL 15-17Z...WITH KSTC ARND 13-14Z. WINDS WILL REMAIN LIGHT FROM THE S/SE ARND 5 KTS...THEN BECOME MORE S/SW THIS AFTN. AM CONCERN THAT FOG/LOW CIGS WILL DEVELOP ONCE AGAIN TONIGHT. LATER SHIFTS WILL NEED TO SEE HOW CLEARING TRENDS AND WIND FIELDS REMAIN. KAXN/KSTC SEEMS TO BE THE BEST CHC OF ISOLD/SCT TSRA THIS AFTN. CONFIDENCE AND TIMING REMAIN LOW. KMSP... LIFR CIGS WILL LIKELY HOLD ACROSS THE AIRFIELD THRU 14Z...WITH CONFIDENCE INCREASING FOR MVFR/VFR CONDS BETWEEN 14-15Z. STILL BELIEVE THE DEPTH OF THE CLD DECK IS SHALLOW ARND THE TWIN CITIES AREA AND SHOULD BREAK UP FAST BY MID MORNING. WINDS WILL BE VARIABLE FROM THE S/SE THIS MORNING...THEN BY LATE MORNING/AFTN...WINDS SHOULD BECOME MORE SW/SSW ARND 8-10 KTS. TSRA CHC/S THIS AFTN ARE TOO LOW TO INTRODUCE VCTS OR CB/S. LATER SHIFTS CAN READJUST BASE ON RADAR TRENDS IN WC MN. THERE IS A POSSIBILITY OF IFR/LIFR CIGS/VSBYS REDEVELOPING LATER TONIGHT. /OUTLOOK FOR KMSP/ SAT...VFR. EARLY MORNING BR/FG POSSIBLE. MVFR ISO SHRA/TSRA POSSIBLE IN THE AFTN. WINDS SW 5-10 KTS. SUN...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS ESE 5 KTS BECMG WNW 5-10KTS. MON...VFR. WINDS NW 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR MNZ074>077- 082>085-091>093. WI...NONE. && $$ SHORT TERM...JLT LONG TERM...CLF AVIATION...JLT
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 AM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT FRI JUN 20 2014 THE NAM AND RAP SHOW AN AREA OF MIDLEVEL CLOUDS ACROSS ERN COLO THIS MORNING BECOMING CONVECTIVELY ACTIVE 09Z-12Z THIS MORNING. THE DISTURBANCE SHOULD MOVE EAST THRU SRN NEB THIS AM PRODUCING A CLUSTER OF ELEVATED TSTMS. THE RAP INDICATES 750MB CAPE OF AROUND 1000 J/KG SUGGESTING THE POTENTIAL FOR SOME HAIL. THIS ACTIVITY DISSIPATES LATE THIS MORNING TO BE FOLLOWED BY A SECOND AREA OF TSTM DEVELOPMENT FROM ROUGHLY KIML NORTHEAST THROUGH KONL THIS AFTN WITH THE BETTER RAIN CHANCES FROM HAYES CENTER NORTHEAST THROUGH KONL. BUFKIT SUGGESTS A WEAK MULTICELL ENVIRONMENT GIVEN THE WEAK SHEAR AROUND 25 KT. MLCAPE THOUGH AROUND 3000 J/KG IN THE RAP MODEL SUGGESTS SOME STRONG UPDRAFTS DEVELOPING THIS AFTN NEAR OR SOUTH OF KOGA AND KLBF. SO SEVERE WEATHER CHANCES CONTINUE ALTHOUGH THE POTENTIAL FOR LONGER LIVED STORMS WOULD APPEAR LOW. STORMS WILL LIKELY FIRE FROM SOUTHWEST NEB TO NCNTL NEB THIS AFTERNOON AND THIS EVENING AND COALESCE INTO CLUSTERS WHICH MOVE OFF EAST OF THE FCST AREA AROUND 06Z. POPS ARE LIMITED TO 40 PERCENT GIVEN THE WEAKNESS IN THE WINDS ALOFT AND LOW QPF GENERATED BY THE MODELS. HIGHS TODAY RISE INTO THE 80S AND LOWS TONIGHT FALL INTO THE 50S TO LOWER 60S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 325 AM CDT FRI JUN 20 2014 MOIST...WARM AND UNSTABLE CONDITIONS WILL CONTINUE ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA SATURDAY. MODELS ALL AGREE THAT A WARM FRONT WILL BE LOCATED IN AN EAST TO WEST FASHION...BUT DISAGREE ON THE LOCATION. REGARDLESS...IT APPEARS THAT SCATTERED TSTMS WILL INITIATE ACROSS THE HIGH PLAINS IN MOIST UPSLOPE REGIME. THESE WILL LIKELY BEGIN AS SUPERCELLS WITH BULK SHEAR NEAR 40 KTS. BUFKIT DATA FROM VARIOUS LOCATIONS ACROSS THE PLAINS SUGGESTS RIGHT TURNING SUPERCELLS THE DOMINATE STORM MODE AT FIRST...THEN CONGEAL INTO ONE OR MORE CLUSTERS SATURDAY NIGHT AS SOUTHERLY LOW LEVEL JET INCREASES. THE WARM FRONT LOCATION WILL HAVE TO BE MONITORED...AS WINDS WILL BE BACKED MORE TO THE EAST ON THE NORTH SIDE OF THE BOUNDARY...WHICH WILL ENHANCE LOW LEVEL SHEAR AND POSSIBLE TORNADO DEVELOPMENT. SUNDAY A SHORTWAVE DISTURBANCE WILL TRACK ACROSS THE NORTHERN ROCKIES AND TOWARD THE NORTHERN PLAINS. A SURFACE LOW WILL DEEPEN ACROSS EASTERN COLORADO IN RESPONSE...WITH MOIST EAST TO NORTHEAST WINDS ACROSS MOST OF WESTERN AND NORTH CENTRAL NEBRASKA TO THE NORTH OF THE LOW. STORM DEVELOPMENT WILL BE AIDED BY THE SHORTWAVE DISTURBANCE ACROSS THE PANHANDLE SUNDAY AFTERNOON...WITH STORMS LIKELY MERGING INTO AN MCS AS THEY TRACK EAST SOUTHEAST ACROSS NEBRASKA SUNDAY EVENING. LOCALLY HEAVY RAIN COULD MATERIALIZE AND POTENTIAL WILL HAVE TO BE MONITORED. MONDAY INTO TUESDAY...SOMEWHAT COOLER AND DRIER BEHIND THE SHORTWAVE DISTURBANCE. BY MIDWEEK...RICH GULF MOISTURE RETURNS. MODELS INDICATING DEW POINTS IN THE UPPER 60S TO NEAR 70 FOR MUCH OF THE FORECAST AREA BY WEEKS END. THATS WHEN TSTM CHANCES MAY INCREASE ONCE AGAIN...AS UPPER LEVEL TROUGHING DEVELOPS INTO THE PACIFIC NORTHWEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 616 AM CDT FRI JUN 20 2014 ISOLATED STORMS ACROSS SWRN NEB THIS MORNING COULD AFFECT KLBF IF THEY CONTINUE MOVING NORTHEAST AS RADAR AND THE RAP MODEL INDICATE. SCATTERED TSRA ARE EXPECTED THIS AFTN FROM KIML-KTIF- KONL AND AREAS EAST. VFR IS EXPECTED ELSEWHERE. THESE STORMS SHOULD EXIT THE FCST AREA TO EAST AROUND 06Z TONIGHT. VFR IS EXPECTED ALL AREAS THEREAFTER. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1045 AM EDT FRI JUN 20 2014 .SYNOPSIS...A SERIES OF UPPER LEVEL DISTURBANCES WILL TRACK SOUTHEAST ACROSS THE MID ATLANTIC AND CAROLINAS TODAY AND SATURDAY... PROPELLING A BACK DOOR COLD FRONT SOUTHWARD THROUGH CENTRAL NORTH CAROLINA BY SATURDAY NIGHT. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 1045 AM FRIDAY... JUST MINOR ADJUSTMENTS MADE TO THE CURRENT FORECAST FOR THE REST OF TODAY. A BATCH OF CONVECTION NOW PUSHING INTO NW NC IS EXPECTED TO CONTINUE PROPAGATING TOWARD THE SE FOR THE NEXT SEVERAL HOURS... FOLLOWING THE WEAK STEERING FLOW NOTED ON 12Z UPPER AIR ANALYSES... ALTHOUGH CONVECTIVE GROWTH AND PROPAGATION TODAY WILL BE LARGELY DRIVEN BY COLD POOL MOTION. THE COLUMN HAS YET TO FULLY DESTABILIZE THIS MORNING DESPITE BRIGHT SUNSHINE (OVER ALL BUT THE FAR NE)... AS MILD MID LEVEL TEMPS ARE THUS FAR HOLDING MLCAPE TO 500 J/KG OR LOWER WITH REMAINING CINH. THE WARMTH ALOFT WILL MAKE FOR WEAK MID LEVEL LAPSE RATES... AND WITH DEEP LAYER SHEAR REMAINING QUITE WEAK... ORGANIZED CONVECTION WILL BE TOUCH TO ACHIEVE. LATEST SURFACE ANALYSIS SHOWS A WEAK FRONTAL ZONE ACROSS NE NC... AND IT IS ALONG AND NE OF THIS ZONE THAT LOW CLOUDS MAY HINDER HEATING AND CURB INSTABILITY TO LIMIT SHOWER/STORM COVERAGE... AND WILL MAINTAIN THE LOWEST POPS HERE... WITH BETTER COVERAGE OVER THE NW PIEDMONT BY EARLY/MID AFTERNOON SPREADING OVER THE SOUTHERN THIRD OF CENTRAL NC DURING THE LATE AFTERNOON INTO EARLY EVENING. THIS SCENARIO IS REPRESENTED WELL BY THE LATEST HIGH-RES WRF-ARW AND WRF-NMM RUNS. THE NAM/GFS DEPICT MODERATE INSTABILITY ONLY IN THE SE CWA THIS AFTERNOON... REASONABLE GIVEN THE OVERALL LOW MID LEVEL LAPSE RATES... AND WITH ANY CONVECTION LIKELY TO BE PULSE IN NATURE... THE RISK OF SEVERE STORMS WILL BE SMALLER THAN IN RECENT DAYS. DOWNDRAFT CAPE IS CURRENTLY VERY LOW BUT THE RAP PREDICTS IT TO RISE RAPIDLY TO OVER 1000 J/KG BY 20Z... SO WE CAN`T RULE OUT A DAMAGING DOWNBURST GUST WITH ANY STORMS. STORM COVERAGE IS STILL EXPECTED TO RISE BY EVENING WITH THE APPROACH OF A MID LEVEL PERTURBATION FROM THE NNW... THAT WILL TRACK SOUTHWARD THROUGH THE AREA... AND WILL HOLD ONTO GOOD CHANCE POPS STARTING THIS EVENING MAINLY IN THE NORTH. EARLIER FORECAST HIGHS FROM 88 (NE) TO 95 (SW) LOOK GOOD AND ARE IN LINE WITH LATEST TRENDS. -GIH PREVIOUS 255 AM DISCUSSION FOR TONIGHT: MODEL GUIDANCE INDICATES RELATIVELY ROBUST SHORTWAVE ENERGY WILL TRACK SOUTHEAST INTO THE MID- ATLANTIC AND CAROLINAS LATE THIS EVENING AND TONIGHT (03-12Z SAT). DURING THIS TIME...LOW-LEVEL FLOW WILL BACK/STRENGTHEN TO 10-15 KT IN RESPONSE TO DPVA AND 20-30 METER 12-HR H5 HEIGHT FALLS...RESULTING IN WEAK LOW-LEVEL WARM ADVECTION BETWEEN 06-12Z AND 500-1000 J/KG OF MUCAPE IN ASSOC/W AN INCREASINGLY WARM/MOIST LOW-LEVEL AIRMASS AND ~6 C/KM MID-LEVEL LAPSE RATES. WITH THE ABOVE IN MIND...WILL INDICATE A 20-30% CHANCE OF CONVECTION ACROSS THE AREA THIS AFTERNOON...WITH INCREASING CHANCES (30-50%) OVERNIGHT. -VINCENT && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 120 AM FRIDAY... SATURDAY IS EXPECTED TO BE CONVECTIVELY ACTIVE AGAIN AS THE FINAL SHOT OF UPPER LEVEL ENERGY IS EXPECTED TO CLIP THE REGION AS THE MAIN LOW LEVEL FOCUS (THE COLD FRONT) SAGS SOUTHWARD THROUGH THE REGION. THE COMBINATION OF THE PIEDMONT TROUGH AND THE SOUTHWARD MOVING COLD FRONT SHOULD INDUCE GOOD CONVERGENCE. STRONG SURFACE HEATING SHOULD ADD PLENTY OF ENERGY FOR LIFT. THEREFORE... ISOLATED SEVERE STORMS WILL BE POSSIBLE WITH THE MAIN THREAT OF DAMAGING WIND. WE WILL BUMP THE POP UPWARD INTO THE LIKELY CATEGORY DURING THE AFTERNOON AND EVENING... TAPERING FROM THE NORTH DURING SATURDAY EVENING. LOCALLY HEAVY RAIN AND FREQUENT LIGHTNING WILL POSE WEATHER HAZARDS. HIGHS GENERALLY 85-90 EXCEPT LOWER 90S OVER THE SANDHILLS BEFORE THE CONVECTION OCCURS. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 105 AM FRIDAY... THE EXTENDED FORECAST GENERALLY REMAINS THE SAME AS IN PREVIOUS DISCUSSIONS. THE MAIN COLD FRONT SHOULD STALL SOUTH OF THE REGION... DEEP INTO SC/GA SUNDAY AND MONDAY. THIS WOULD HAVE SOME IMPACTS ON SENSIBLE WEATHER INCLUDING LOWER POP SUNDAY AND MONDAY... BEFORE RAMPING UP AGAIN MIDWEEK. IN ADDITION... THE TEMPERATURES WILL BE COOLER THAN IN THE RECENT EARLY HEAT SPELL SUNDAY AND MONDAY AS THE WINDS BECOME NE-E. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 645 AM FRIDAY... 24-HR TAF PERIOD: ASIDE FROM A POTENTIAL FOR ISOLD CONVECTION AT ANY TERMINAL THIS AFTERNOON (18-00Z)...VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL THROUGH 00Z THIS EVENING. SIGNIFICANT UNCERTAINTY PERSISTS WITH REGARD TO THE TIMING AND COVERAGE OF CONVECTION TODAY...PRECLUDING EXPLICIT MENTION OF CONVECTION THIS AFTERNOON IN THE 12Z TAF ISSUANCE. THE LATEST MODEL GUIDANCE SUGGESTS THE BEST POTENTIAL FOR (AND COVERAGE OF) CONVECTION WILL BE THIS EVENING THROUGH TONIGHT (00-12Z SAT) WHEN MORE ROBUST UPPER LEVEL DISTURBANCES ARE PROGGED TO TRACK INTO THE REGION FROM THE NORTHWEST. AS A RESULT...WILL INTRODUCE VCSH AT ALL TERMINALS BEGINNING AT 00Z FOR AN INCREASED POTENTIAL OF SHOWERS/STORMS LATER THIS EVENING THROUGH TONIGHT. LOOKING AHEAD: SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED ON SATURDAY IN ASSOC/W UPPER LEVEL DISTURBANCES IN NW FLOW ALOFT...ESP AT THE RDU/RWI/FAY TERMINALS WHERE ISOLD SVR CONVECTION WILL BE POSSIBLE DURING THE AFT/EVE HOURS. ASIDE FROM A POTENTIAL FOR ISOLD TO SCT CONVECTION DURING THE AFT/EVE AND A POTENTIAL FOR A BRIEF PERIOD OF PRE-DAWN FOG OR STRATUS...VFR CONDITIONS WILL PREVAIL SUN-WED. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD/VINCENT SHORT TERM...32 LONG TERM...32 AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1000 AM CDT FRI JUN 20 2014 .UPDATE... ISSUED AT 955 AM CDT FRI JUN 20 2014 NO MAJOR CHANGES TO THIS UPDATE. HAVE ADDED SOME THUNDER INTO THE FAR SOUTHWEST THIS AFTERNOON...AND EXTENDED THUNDER CHANCES IN ALL AREAS THROUGH 00Z. A STRONG SHORTWAVE...UPPER SPEED MAX AND INSTABILITY SHOULD MEAN SCATTERED STORMS THIS AFTERNOON. THE DEEP LAYERED SHEAR IS STRONG...AROUND 50-60KT...SO IF SFC DEWPOINTS CAN RISE INTO THE MID 60S...CAPES AROUND 1500 J/KG WOULD OCCUR. THIS WOULD BE ENOUGH FOR SOME SEVERE STORMS...WITH THE MAIN THREATS LARGE HAIL AND DAMAGING WINDS. IT APPEARS THAT STORM INITIATION SHOULD OCCUR NEAR THE VALLEY...WITH THE BEST SEVERE THREAT EAST OF THE VALLEY. THIS IS IN LINE WITH THE LATEST SPC SLIGHT RISK AREA MAINLY IN MN. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 335 AM CDT FRI JUN 20 2014 PRECIP CHANCES AND STRENGTH WILL BE THE MAIN FORECAST ISSUE FOR THE SHORT TERM. UPPER LOW CURRENTLY CENTERED ALONG THE MT/CANADIAN BORDER...AND MODELS ARE IN PRETTY GOOD AGREEMENT ON TRACKING THE UPPER LOW SLOWLY EASTWARD TODAY. THERE WILL BE A STRONG VORT MAX/JET STREAK COMING INTO THE CWA BY THIS AFTERNOON. WITH THE STRONG UPPER LEVEL SYSTEM COMING THROUGH...BULK SHEAR VALUES WILL BE VERY STRONG...UP IN THE 50 TO 60 KT RANGE ACROSS PORTIONS OF THE SOUTHERN CWA. MORE IN QUESTION WILL BE THE INSTABILITY. THE NAM BRINGS CAPE VALUES OF 1500-2000 J/KG INTO OUR SOUTHEASTERN COUNTIES...AND THE RUC IS SIMILAR BUT MORE IN THE 1000-1500 RANGE. STRATUS OVER THE EAST HAS BEEN CLEARING OUT AND FOG HAS BEEN NOT VERY WIDESPREAD...SO THERE SHOULD BE AT LEAST A LITTLE BIT OF HEATING THIS AFTERNOON. HOWEVER...CLOUDS HAVE BEEN INCREASING OVER THE WESTERN COUNTIES AND REGIONAL RADAR SHOWS QUITE A BIT OF ACTIVITY OVER WESTERN ND WITH THE JET STREAK COMING OUT. THE UPPER SUPPORT MAY BE INTO THE ARE BEFORE WE CAN DESTABILIZE ENOUGH. FOR THAT REASON...BUMPED UP POPS AND WILL MENTION CHANCE OF SEVERE IN THE HWO...BUT WILL KEEP A SEVERE MENTION OUT OF THE GRIDS FOR THE TIME BEING. TONIGHT...THE MAIN UPPER LOW WILL LIFT NORTHEASTWARD INTO CANADA. A FEW SHOWERS MAY BE HANGING AROUND THE NORTHEASTERN COUNTIES EARLY ON BUT THINK THERE WILL BE A BREAK IN PRECIP FOR MUCH OF THE NIGHT. CONTINUED TO KEEP TEMPS OVERNIGHT IN THE UPPER 50S TO LOW 60S. SUNSHINE AND SOUTH TO SOUTHWESTERLY SFC WINDS SHOULD HELP HIGHS ON SATURDAY REACH THE 80S IN MANY AREAS. BY SATURDAY AFTERNOON...A WEAK SHORTWAVE PUSHING IN FROM THE WEST WILL HELP BRING A SFC TROUGH AXIS INTO CENTRAL ND AND THERE SHOULD BE SOME CONVECTIVE ACTIVITY ALONG WITH IT. BULK SHEAR VALUES ARE QUITE A BIT LOWER BUT THERE SHOULD BE DECENT INSTABILITY. WILL CONTINUE TO KEEP CHANCE POPS GOING. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM CDT FRI JUN 20 2014 SATURDAY NIGHT THROUGH SUNDAY NIGHT...MORE SHORTWAVES MOVE THROUGH AS THE ACTIVE PATTERN CONTINUES UNDER WEST TO SOUTHWESTERLY FLOW ALOFT. THE MAIN SFC TROUGH WILL MOVE OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY...WITH SOME WEAK COLD AIR ADVECTION BEHIND IT. THINK THAT BEST CHANCES FOR PRECIP WILL BE LATE SATURDAY NIGHT INTO SUNDAY AS THIS FEATURE MOVES THROUGH. KEPT 20-40 POPS GOING BEFORE TAPERING THEM OFF SUNDAY NIGHT. TEMPS ON SUNDAY WILL BE A BIT LOWER THAN SATURDAY...MAINLY IN THE 70S. MONDAY THROUGH THURSDAY...THIS PERIOD WILL BE CATEGORIZED BY MEAN ZONAL FLOW...THE UPPER LOW HAVING DEPARTED TO THE EAST. SEVERAL SHORT WAVE RIPPLES LIKELY TO MOVE THROUGH THIS FLOW...OFFERING PCPN CHANCES PERHAPS TUESDAY AND AGAIN ON THURSDAY. BELIEVE THE BEST BET FOR TOTALLY DRY WILL COME MIDWEEK...AS BOTH 00Z GFS/ECMWF DEPICT A BUBBLE OF CANADIAN HIGH PRESSURE FOR WEDNESDAY. LOOKS LIKE WARMEST DAY WILL BE MONDAY WITH COOLER READINGS UNDER MORE CLOUD COVER TUESDAY...RECOVERING TO NEAR AVERAGE FOR LATE JUNE BY WED/THUR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 657 AM CDT FRI JUN 20 2014 KBJI STILL HAS SOME 1/4SM BUT WEB CAMS SHOW FOG IS SHALLOW AND PATCHY...SO HAVE IT ENDING BY 13Z. REST OF TAF SITES REMAIN VFR. MID LEVEL CLOUDS WILL INCREASE FROM THE WEST THROUGHOUT THE DAY. SOME SCATTERED SHOWERS WILL MOVE FROM THE KDVL AREA EASTWARD THROUGHOUT THE DAY. SOME CONVECTION IS POSSIBLE LATER TODAY...BUT FOR NOW MAINLY WENT WITH VCTS AS ACTIVITY WILL BE FAIRLY SCATTERED. WINDS WILL SHIFT AROUND TO THE SOUTHWEST AND THEN TO THE SOUTH BY THE END OF THE PERIOD. && .HYDROLOGY... ISSUED AT 252 PM CDT THU JUN 19 2014 RECENT HEAVY RAINS OVER THE RED RIVER BASIN IS CAUSING RISES ON THE MAINSTEM RED RIVER AND MINNESOTA TRIBUTARIES. RAINFALL AMOUNTS RANGED FROM 2.5 INCHES AROUND THE WAHPETON/BRECKENRIDGE AREA TO AROUND A QUARTER INCH IN BELTRAMI AND LAKE OF THE WOODS COUNTIES. WITH THE RAINFALL...NEW RIVER POINT WARNINGS HAVE BEEN ISSUED RAISING ABERCROMBIE...FARGO AND OSLO TO MODERATE FLOOD STAGE. AN AREAL FLOOD WARNING HAS BEEN ISSUED UNTIL NOON SUNDAY FOR EAST CENTRAL BELTRAMI COUNTY. BELTRAMI COUNTY EMERGENCY MANAGEMENT RELAYED THAT THE TAMARAC RIVER NEAR WASKISH IS WELL OUT OF ITS BANKS. WATER IS SURROUNDING NUMEROUS HOUSES WITH A FEW ROADS WASHED OUT...AND NUMEROUS AGRICULTURAL FIELDS ARE UNDER WATER. WATER IS ALSO BEGINNING TO APPROACH THE BOTTOMS OF BRIDGES ALONG THE TAMARAC RIVER. MORE WATER IS EXPECTED TO FLOW INTO THE TAMARAC RIVER...AND THE SITUATION CONTINUES TO BE MONITORED. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...JR LONG TERM...WJB AVIATION...JR HYDROLOGY...HOPKINS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
657 AM CDT FRI JUN 20 2014 .UPDATE... ISSUED AT 657 AM CDT FRI JUN 20 2014 PATCHY FOG IN THE SOUTHEAST COUNTIES HAVE BROUGHT PKD AND BJI DOWN TO 1/4SM AT TIMES THIS MORNING...BUT WEB CAMS SHOW THAT FOG IS PATCHY AND SHALLOW. WILL CONTINUE TO KEEP A MENTION OF PATCHY FOG IN THE GRIDS FOR THE NEXT FEW HOURS BUT THINK THAT THE FOG SHOULD BURN OFF FAIRLY QUICKLY UNDER THE STRONG JUNE SUN. MID LEVEL CLOUDS ARE INCREASING FROM THE EAST AND COULD STILL HAVE AN IMPACT ON DESTABILIZATION LATER THIS AFTERNOON. MADE A FEW MINOR TWEAKS TO POPS FOR SHOWERS THIS MORNING OVER OUR NORTHWESTERN COUNTIES...BUT KEPT THE SCATTERED MENTION FOR LATER THIS AFTERNOON. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 335 AM CDT FRI JUN 20 2014 PRECIP CHANCES AND STRENGTH WILL BE THE MAIN FORECAST ISSUE FOR THE SHORT TERM. UPPER LOW CURRENTLY CENTERED ALONG THE MT/CANADIAN BORDER...AND MODELS ARE IN PRETTY GOOD AGREEMENT ON TRACKING THE UPPER LOW SLOWLY EASTWARD TODAY. THERE WILL BE A STRONG VORT MAX/JET STREAK COMING INTO THE CWA BY THIS AFTERNOON. WITH THE STRONG UPPER LEVEL SYSTEM COMING THROUGH...BULK SHEAR VALUES WILL BE VERY STRONG...UP IN THE 50 TO 60 KT RANGE ACROSS PORTIONS OF THE SOUTHERN CWA. MORE IN QUESTION WILL BE THE INSTABILITY. THE NAM BRINGS CAPE VALUES OF 1500-2000 J/KG INTO OUR SOUTHEASTERN COUNTIES...AND THE RUC IS SIMILAR BUT MORE IN THE 1000-1500 RANGE. STRATUS OVER THE EAST HAS BEEN CLEARING OUT AND FOG HAS BEEN NOT VERY WIDESPREAD...SO THERE SHOULD BE AT LEAST A LITTLE BIT OF HEATING THIS AFTERNOON. HOWEVER...CLOUDS HAVE BEEN INCREASING OVER THE WESTERN COUNTIES AND REGIONAL RADAR SHOWS QUITE A BIT OF ACTIVITY OVER WESTERN ND WITH THE JET STREAK COMING OUT. THE UPPER SUPPORT MAY BE INTO THE ARE BEFORE WE CAN DESTABILIZE ENOUGH. FOR THAT REASON...BUMPED UP POPS AND WILL MENTION CHANCE OF SEVERE IN THE HWO...BUT WILL KEEP A SEVERE MENTION OUT OF THE GRIDS FOR THE TIME BEING. TONIGHT...THE MAIN UPPER LOW WILL LIFT NORTHEASTWARD INTO CANADA. A FEW SHOWERS MAY BE HANGING AROUND THE NORTHEASTERN COUNTIES EARLY ON BUT THINK THERE WILL BE A BREAK IN PRECIP FOR MUCH OF THE NIGHT. CONTINUED TO KEEP TEMPS OVERNIGHT IN THE UPPER 50S TO LOW 60S. SUNSHINE AND SOUTH TO SOUTHWESTERLY SFC WINDS SHOULD HELP HIGHS ON SATURDAY REACH THE 80S IN MANY AREAS. BY SATURDAY AFTERNOON...A WEAK SHORTWAVE PUSHING IN FROM THE WEST WILL HELP BRING A SFC TROUGH AXIS INTO CENTRAL ND AND THERE SHOULD BE SOME CONVECTIVE ACTIVITY ALONG WITH IT. BULK SHEAR VALUES ARE QUITE A BIT LOWER BUT THERE SHOULD BE DECENT INSTABILITY. WILL CONTINUE TO KEEP CHANCE POPS GOING. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM CDT FRI JUN 20 2014 SATURDAY NIGHT THROUGH SUNDAY NIGHT...MORE SHORTWAVES MOVE THROUGH AS THE ACTIVE PATTERN CONTINUES UNDER WEST TO SOUTHWESTERLY FLOW ALOFT. THE MAIN SFC TROUGH WILL MOVE OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY...WITH SOME WEAK COLD AIR ADVECTION BEHIND IT. THINK THAT BEST CHANCES FOR PRECIP WILL BE LATE SATURDAY NIGHT INTO SUNDAY AS THIS FEATURE MOVES THROUGH. KEPT 20-40 POPS GOING BEFORE TAPERING THEM OFF SUNDAY NIGHT. TEMPS ON SUNDAY WILL BE A BIT LOWER THAN SATURDAY...MAINLY IN THE 70S. MONDAY THROUGH THURSDAY...THIS PERIOD WILL BE CATEGORIZED BY MEAN ZONAL FLOW...THE UPPER LOW HAVING DEPARTED TO THE EAST. SEVERAL SHORT WAVE RIPPLES LIKELY TO MOVE THROUGH THIS FLOW...OFFERING PCPN CHANCES PERHAPS TUESDAY AND AGAIN ON THURSDAY. BELIEVE THE BEST BET FOR TOTALLY DRY WILL COME MIDWEEK...AS BOTH 00Z GFS/ECMWF DEPICT A BUBBLE OF CANADIAN HIGH PRESSURE FOR WEDNESDAY. LOOKS LIKE WARMEST DAY WILL BE MONDAY WITH COOLER READINGS UNDER MORE CLOUD COVER TUESDAY...RECOVERING TO NEAR AVERAGE FOR LATE JUNE BY WED/THUR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 657 AM CDT FRI JUN 20 2014 KBJI STILL HAS SOME 1/4SM BUT WEB CAMS SHOW FOG IS SHALLOW AND PATCHY...SO HAVE IT ENDING BY 13Z. REST OF TAF SITES REMAIN VFR. MID LEVEL CLOUDS WILL INCREASE FROM THE WEST THROUGHOUT THE DAY. SOME SCATTERED SHOWERS WILL MOVE FROM THE KDVL AREA EASTWARD THROUGHOUT THE DAY. SOME CONVECTION IS POSSIBLE LATER TODAY...BUT FOR NOW MAINLY WENT WITH VCTS AS ACTIVITY WILL BE FAIRLY SCATTERED. WINDS WILL SHIFT AROUND TO THE SOUTHWEST AND THEN TO THE SOUTH BY THE END OF THE PERIOD. && .HYDROLOGY... ISSUED AT 252 PM CDT THU JUN 19 2014 RECENT HEAVY RAINS OVER THE RED RIVER BASIN IS CAUSING RISES ON THE MAINSTEM RED RIVER AND MINNESOTA TRIBUTARIES. RAINFALL AMOUNTS RANGED FROM 2.5 INCHES AROUND THE WAHPETON/BRECKENRIDGE AREA TO AROUND A QUARTER INCH IN BELTRAMI AND LAKE OF THE WOODS COUNTIES. WITH THE RAINFALL...NEW RIVER POINT WARNINGS HAVE BEEN ISSUED RAISING ABERCROMBIE...FARGO AND OSLO TO MODERATE FLOOD STAGE. AN AREAL FLOOD WARNING HAS BEEN ISSUED UNTIL NOON SUNDAY FOR EAST CENTRAL BELTRAMI COUNTY. BELTRAMI COUNTY EMERGENCY MANAGEMENT RELAYED THAT THE TAMARAC RIVER NEAR WASKISH IS WELL OUT OF ITS BANKS. WATER IS SURROUNDING NUMEROUS HOUSES WITH A FEW ROADS WASHED OUT...AND NUMEROUS AGRICULTURAL FIELDS ARE UNDER WATER. WATER IS ALSO BEGINNING TO APPROACH THE BOTTOMS OF BRIDGES ALONG THE TAMARAC RIVER. MORE WATER IS EXPECTED TO FLOW INTO THE TAMARAC RIVER...AND THE SITUATION CONTINUES TO BE MONITORED. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...JR LONG TERM...WJB AVIATION...JR HYDROLOGY...HOPKINS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
326 AM PDT FRI JUN 20 2014 .SYNOPSIS...COOLER WITH LOTS OF CLOUDS TODAY THEN A PATTERN OF MORNING CLOUDS WITH AFTERNOON SUNSHINE EXPECTED FOR THE WEEKEND. MILD WEATHER CONTINUES NEXT WEEK...BUT MAY HAVE A FEW SHOWERS ABOUT THE AREA...MAINLY FROM OVER THE CASCADES AND POINTS EASTWARD. && .SHORT TERM...TODAY THROUGH MONDAY...FRONT HELD TOGETHER LONG ENOUGH TO BRING 0.10 TO 0.20 INCHES OF RAIN TO THE IMMEDIATE COAST WITH LESSER AMOUNTS CLOSER TO NEWPORT. IT SHEARED APART UPON CROSSING THE COAST RANGE AND IS NOT SOMEWHAT OF A DISJOINTED MESS OVER THE VALLEY AND CASCADES. HAVE SQUEEZED OUT CLOSE TO A TENTH FOR THE PORTLAND AIRPORT WHERE LOW LEVEL CONVERGENT FLOW BRIEFLY AND LOCALLY RE-ENERGIZED THE FRONT. 06Z NAM AND THE 07Z HRRR SHOW THE FRONT WILL CONTINUE TO DISSIPATE AS IT DRIFTS EASTWARD WITH LINGERING CASCADE AND FOOTHILL SHOWERS THROUGH AT LEAST THE EARLY MORNING. POST FRONTAL JET ASSISTED LIFT IS BRINGING ISOLATED SHOWER ACTIVITY OVER THE WATERS SO HAVE ADDED THE MENTION OF SUCH FOR THE MORNING. KEPT DRIZZLE IN THE FORECAST FOR THE MORNING INLAND AND WEST OF THE CASCADE FOOTHILLS AS AM HAVING A HARD TIME IGNORING THE MODESTLY DEEP MOISTURE FIELD PLUS LIFT THROUGH IT FROM THE 00Z GFS. AM HAVING STRONG SUSPICIONS, HOWEVER, WE MAY BE OVERDOING IT GIVEN THE HIGHER CLOUD BASES OF 3 TO 4 THOUSAND FEET FROM TILLAMOOK AND GENERALLY POINTS NORTHWARD ALONG THE COAST. WOULD PREFER TO SEE BASES BELOW 1500 FEET TO FEEL BETTER ABOUT DRIZZLE NOT EVAPORATING BEFORE REACHING THE SURFACE. WILL REASSESS CLOSER TO THE END OF SHIFT. NOT MUCH CHANGE FOR THE REST OF THE FORECAST HEADING INTO MONDAY AS THE REGION WILL SEE MORNING CLOUDS FOLLOWED BY AFTERNOON SUN OR AT LEAST SIGNIFICANT SUN BREAKS. THIS PATTERN WILL ALSO BRING SOME DECENTLY CONSISTENT BREEZY WEST WINDS TO THE CENTRAL GORGE AS PERSISTENT SURFACE LOW PRESSURE WILL SET UP OVER THE COLUMBIA BASIN. REGARDING TEMPERATURES...TODAY LOOKS TO BE TO COOLEST OF THE UPCOMING FEW DAYS AS CLOUDS WILL MOST LIKELY HANG ON THE LONGEST. MONDAY MAY ALSO BE A BIT TRICKY AS ANOTHER FEATURE APPROACHES THE COAST BUT ALSO SUSPECT TIMING WILL KEEP THE PRIMARY THREAT FOR RAIN UNTIL LATER IN THE EVENING. THIS SHOULD OFFSET TEMPERATURES COOLING OFF MORE THAN A COUPLE DEGREES FROM SUNDAY. /JBONK .LONG TERM...MONDAY NIGHT THROUGH THURSDAY...HAVE MADE SOME CHANGES TO REFLECT CONTINUED UNCERTAINTY IN THE EXTENDED PERIODS. HAVE SEEN NOTABLE INCONSISTENCY BETWEEN THE 12Z AND 00Z RUNS...NOT SO MUCH IN THE LARGE SCALE PATTERN BUT WITH THE DETAILS REGARDING MOISTURE AND SHORTWAVE TIMING. THE UPPER TROUGH SITTING SOMEWHAT OFF THE PACNW COAST FREQUENTLY PROVES PROBLEMATIC FOR MODELS AND KEEPING TRACK OF THE IMPORTANT FEATURES WHICH BRING THE DETAILS BETTER INTO FOCUS. MAIN CONCERN IS WHICH DAYS APPEAR TO BE MOST LIKELY FOR AFTERNOON/EVENING SHOWERS. AT THIS POINT...DO NOT HAVE OVERWHELMING CONFIDENCE TO GO WHOLE HOG EITHER WAY FOR THE MAJORITY OF THE PERIODS. AM KEEPING AN EYE OUT FOR WEDNESDAY NIGHT AND THURSDAY...HOWEVER...AS ONE SHORTWAVE MAY STRENGTHEN ENOUGH TO PUSH A NEGATIVE TILT TO THE TROUGH AS IT PASSES. THIS PATTERN OFTEN SIGNALS A THUNDERSTORM THREAT. FOR NOW...TIMING PRESENTS THE BEST DYNAMIC SUPPORT FOR THUNDERSTORMS JUST EAST OF THE CASCADE CREST BUT WILL BE WATCHING. /JBONK && .AVIATION...FAIRLY NARROW NORTH-SOUTH ORIENTED FRONT MOVING ACROSS THE INTERIOR LOWLANDS AT 10Z AND SHOULD BE IN THE CASCADES BY 12Z. AREAS OF MVFR EXPECTED WITH THE FRONT FOLLOWED BY VFR CONDITIONS AS A DRIER...MORE UNSTABLE AIR MASS MOVES INTO THE AREA. GENERALLY SHOULD SEE VFR FOR MOST AREAS BY 13Z-15Z. VFR CONDITIONS ARE THEN EXPECTED THROUGH 12Z SATURDAY. KPDX AND APPROACHES...MVFR CIGS AROUND 2500 FT IN THE AREA AS THE FRONT MOVES INTO THE CASCADES. && .MARINE...HIGH PRES RETURNS TO THE WATERS THIS MORNING BEHIND A WEAK COLD FRONT. WINDS ARE STILL A LITTLE GUSTY BUT REMAIN BELOW ADVISORY CRITERIA. FOR THE REMAINDER OF THE WEEKEND AND INTO EARLY NEXT WEEK NORTHERLY WINDS MAY OCCASIONALLY GUST TO AROUND 20 KT DURING THE AFTERNOON AND EARLY EVENING...PARTICULARLY FOR THE WATERS SOUTH OF CASCADE HEAD. SEAS SHOULD REMAIN IN THE 6 TO 8 FT RANGE TODAY THEN SETTLE TO AROUND 5 FT SAT AND INTO EARLY NEXT WEEK. OTHERWISE...A COUPLE WEEK FRONTAL SYSTEMS WILL TRACK ACROSS THE WATERS EARLY NEXT WEEK...BUT NO MAJOR WIND OR SEA ISSUES APPEAR IN STORE. /NEUMAN/MH && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND 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
1040 AM EDT FRI JUN 20 2014 .SYNOPSIS... HIGH PRESSURE WILL WEAKEN AS AN UPPER RIDGE GRADUALLY BREAKS DOWN TODAY. THIS SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA OVER THE WEEKEND. TYPICAL SUMMERTIME WEATHER CONTINUES ACROSS THE REGION NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1030 AM UPDATE...SCATTERED TSTMS CONTINUE TO BUBBLE ACRS UPPER EAST TN AND SW VA UNDERNEATH A VERY WEAK SHORTWAVE ROUNDING THE UPPER RIDGE...WITH ADDITIONAL FORCING LIKELY COMING FROM THE MEAN NWLY FLOW INTO THE HIGHER TERRAIN. SOME OF THIS ACTIVITY HAS ALREADY MOVED ACRS THE NC BORDER AND OVERALL IT SHOULD SPREAD INTO THE NRN FOOTHILLS/PIEDMONT THRU MIDDAY FOLLOWING THE WAVE. HOWEVER...DOWNSLOPING SEEMS TO BE ACTING AGAINST THE LEADING CELLS ATTM AND THIS SHOULD KEEP COVERAGE RATHER LOW. LATEST RUNS OF CONVECTION ALLOWING MODELS SHOW FAIRLY LIMITED COVERAGE AS THE DAY PROGRESSES. THE 12Z NAM FOLLOWS THE 06Z IN OVERDOING SBCAPE THIS AFTN ACRS PORTIONS OF THE AREA...HAVING 4000 OR MORE J/KG ALONG WITH DEWPOINTS IN THE UPPER 70S. CURRENT READINGS ARE MOSTLY IN THE MID 60S AND WITH MEAN NLY FLOW IT JUST DOESN/T SEEM PLAUSIBLE TO EXPECT THEM TO SKYROCKET. 12Z AREA RAOBS SHOW SOME DRIER AIR JUST OFF THE SFC AND SOME GUIDANCE...INCLUDING THE RAP...SHOW DEWPOINTS DROPPING SEVERAL DEGREES THIS AFTN. CAPE VALUES FROM THE RAP ARE ACCORDINGLY MUCH LOWER. I WILL CLOSELY MONITOR DEWPOINTS OVER THE NEXT COUPLE HRS TO SEE IF THEY INDEED MIX OUT...AND HAVE PRELIMINARILY LOWERED POPS OVER THE PIEDMONT THIS AFTN CLOSER TO CLIMO VALUES GIVEN THIS EXPECTATION. PREVIOUS DISCUSSION... AS OF 315 AM EDT FRIDAY...UPPER RIDGE NOW CENTERED OVER THE MISSISSIPPI DELTA WILL SLOWLY CONTINUE TO RETROGRADE WEST ALLOWING THE UPPER PATTERN ACROSS THE EASTERN CONUS TO FLATTEN. AT THE SURFACE...A WEAK FRONTAL BOUNDARY THAT PUSHED THROUGH THE REGION ON THURSDAY EVENING WILL REMAIN ALONG THE GA/SC COASTLINE LEADING TO PREVAILING WEST NORTHWEST FLOW ACROSS THE SOUTHERN APPS ON FRIDAY. THIS WILL YIELD SLIGHTLY LOWER DEWPOINTS ACROSS THE REGION THAN DAYS PAST...THEREBY LEADING TO LESS DIURNAL INSTABILITY. HOWEVER...IT IS STILL JUNE AND LAPSE RATES...AND MOISTURE...WILL BE SUFFICIENT FOR SHOWER AND THUNDERSTORM DEVELOPMENT IF LIFT IS PROVIDED. WITH THAT...THE LATEST 12KM NAM INDICATES A SERIES OF H5 IMPULSES EJECTING THROUGH THE MEAN UPPER NW FLOW AND INTO THE FORECAST AREA THIS AFTERNOON AND EVENING. EXPECTING CONVECTIVE INITIATION ACROSS THE NC PIEDMONT THIS AFTERNOON WHEN PEAK HEATING COMBINES WITH THE FIRST OF THE SERIES OF UPPER IMPULSES. THIS CONVECTION WILL LIKELY PROPAGATE SOUTHEAST INTO PORTIONS OF THE UPSTATE BEFORE EXITING INTO THE MIDLANDS AFTER SUNSET. MEANWHILE...EXPECTING AN MCS TO BE PUSHING TOWARDS THE SOUTHERN APPS OUT OF EASTERN KY AND MIDDLE TN. IF THE ATMOSPHERE IS NOT TOO WORKED OVER FROM PREVIOUS CONVECTION...COULD SEE THIS MCS ENTERING THE TERRAIN...POTENTIALLY PUSHING INTO THE FOOTHILLS BEFORE DECAYING BY EARLY MORNING. THUS...FORECAST WILL FAVOR INCREASING POPS TO SOLID CHANCE LEVELS ACROSS THE ENTIRE REGION FOR THE LATE AFTERNOON AND EARLY EVENING HOURS BEFORE DECREASING ACROSS THE EAST LATE IN THE EVENING. POPS WILL REMAIN ELEVATED AT CHANCE LEVELS ACROSS THE HIGH TERRAIN DUE TO POTENTIAL OF ABOVE MENTIONED MCS AND WEAK NW UPSLOPE FLOW. NOT EXPECTING ANY WIDESPREAD SEVERE THREATS WITH ANY THUNDERSTORMS THAT DO DEVELOP DUE TO HIGH LFCS AND POOR MID LEVEL LAPSE RATES. HOWEVER...CANNOT RULE OUT AN OCCASIONAL SEVERE DOWNBURST WITH ANY COLLAPSING STORMS AS INVERTED V SOUNDINGS ARE PRESENT PER LATEST NAM FORECAST PROFILES. TEMPERATURES THROUGH THE NEAR TERM PERIOD WILL REMAIN ABOVE NORMAL. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 230 AM FRIDAY...MODELS CONTINUE TO INDICATE THAT H5 HEIGHTS WILL SLOWLY FALL ACROSS THE REGION SAT/SUN AS AN UPPER H5 HIGH RETROGRADES TOWARD THE SOUTH CENTRAL STATES AND AN UPPER TROUGH ROTATES OFF THE NE COAST. A SERIES OF UPPER IMPULSES WILL TRIGGER MCS/MCC OVER THE OHIO VALLEY FRI NIGHT AND PROPAGATE TOWARD THE NORTHERN NC PIEDMONT THRU EARLY SAT. HOWEVER...WITH THE LOSS OF HEATING/CAPE OVERNIGHT...THIS SYSTEM SHOULD WEAKEN CONSIDERABLY AS IT PASSES JUST TO OUR NORTH. HENCE...HAVE INHERITED LOW END CHANCE POPS MAINLY IN THE NORTHERN ZONES SAT MORNING. FOR SAT AFTERNOON...A BACK DOOR FRONTAL BOUNDARY WILL PUSH SOUTH...WITH SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE FRONT MAINLY IN THE NC PIEDMONT ZONES. THE NAM/GFS KEEPS THE CONDITIONS RELATIVELY DRY IN THE MTN/UPSTATE SC GIVEN MUCH DRIER PROFILE IN PREDOMINANT N/NW FLOW ALOFT. WITH THE HELP OF DOWNSLOPING WINDS...TEMPERATURES WILL BE AROUND 3-5 DEGREES ABOVE NORMAL OVER THE PIEDMONT WITH NEAR NORMAL IN THE MTNS. SUN...HIGH PRESSURE CENTERED OVER THE NE WILL NOSE DOWN INTO THE REGION...WITH ANOTHER ROUND OF MCS/MCC DEVELOPING OVER IN THE VICINITY OF KY/OHIO VALLEY...PROPAGATING SOUTHWARD TOWARD THE SOUTHERN APPALACHIANS SUN AFTERNOON. THIS FEATURE WILL REACH THE TN BORDERLINE AROUND 21Z SUN PER LATEST NAM AND WEAKENS CONSIDERABLY (THE NAM TOTALLY DRIES OUT) AS IT MOVES ACROSS EAST OF THE MTNS. THIS IS DUE TO THE PREVAILING N/NW DOWNSLOPE WINDS YIELDING MUCH DRIER PROFILE/STABLE ENVIRONMENT OVER THE PIEDMONT. HENCE...POPS REMAIN IN THE SLIGHT CHANCE/LOW CHANCE RANGE ACROSS MUCH OF THE REGION...WITH BETTER CHANCE IN THE MTN ZONES. TEMPERATURES WILL COOL DOWN BY 2-3 DEGREES ON SUN. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 130 AM EDT FRIDAY...THE LATEST GLOBAL MODELS AGREE THAT WEAK UPPER RIDGING WILL BUILD ACROSS THE SE U.S. MONDAY IN RESPONSE TO AN APPROACHING UPPER TROUGH FROM THE UPPER MIDWEST. HOWEVER...MODELS CONTINUE TO DIVERGE QUIET A BIT BY TUE...WITH THE GFS EARLIER AND DEEPER WITH THE TROUGH PERSISTING ACROSS THE EASTERN STATES LATE TUE INTO FRI. MEANWHILE...THE ECMWF SUGGESTS THAT RATHER WEAK UPPER TROUGH WILL PASS NORTH OF THE REGION LATE WED...WITH AN UPPER RIDGE BUILDING BACK IN FROM THE WEST BY THU. AT THE SURFACE...HIGH PRESSURE WILL WEAKEN AND GRADUALLY SHIFT EAST MON INTO TUE AS A COLD FRONT APPROACHES FROM THE WEST. THE COMBINATION OF INCREASING ATLANTIC MOISTURE ADVECTION IN SELY FLOW...WEAKLY SHEARED ENVIRONMENT AND MODERATE DIURNAL BUOYANCY...WE WILL SEE SOLID CHANCE OF PULSE TYPE CONVECTION ACROSS MUCH OF THE REGION...FAVORING IN THE MTN ZONES. BOTH THE GFS AND ECMWF PUSH A COLD FRONT FROM WEST TO EAST THROUGH THE REGION ON WED YIELDING GREATER COVERAGE OF CONVECTION. WEAK SURFACE HIGH RETURNS ON THURSDAY WITH DIURNALLY DRIVEN CONVECTION EXPECTED. TEMPERATURES WILL REMAIN NEAR NORMAL RANGE THROUGH THE PERIOD. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH THE EXCEPTION OF MVFR VISB RESTRICITONS DUE TO POSSIBLE AFTERNOON TSRA. FEW/SCT HIGH CIRRUS WILL PERSIST THROUGH THE MID/LATE MORNING BEFORE GIVING WAY TO SCT LOW VFR CU AS HEATING BUILDS AND LAPSE RATES STEEPEN IN THE PBL. EXPECTING A BKN CU FIELD TO DEVELOP ACROSS THE PIEDMONT IN THE EARLY AFTERNOON HOURS OF PEAK HEATING...ALONG WITH INCREASING INSTABILITY AND TSRA POTENTIAL. BACKED UP BY ONE HOUR AND KEPT PREVIOUS TSRA MENTION IN THE FORM OF A TEMPO FROM 19-23Z. WINDS THROUGH THE PERIOD WILL REMAIN WEST NORTHWESTERLY AND IN THE 5-8KTS RANGE BEFORE CALMING THIS EVENING. ELSEWHERE...FEW TO SCT MID/HIGH CLOUDS WILL PREVAIL THROUGH MID MORNING BEFORE ALL SITES EXPERIENCE DEVELOPING CU THROUGH THE HEATING OF THE DAY. KEPT PREVIOUS WX MENTIONS AT ALL SITES FOR POSSIBLE AFTERNOON TSRA AND MVFR RESTRICTIONS IN THE FORM OF TEMPO OR PROB30 DEPENDING ON TIMING AND CONFIDENCE AT THE SITE. ADDED PROB30 NEAR THE END OF THE PERIOD FOR KAVL AS NORTHWEST FLOW COULD PROLONG SHOWER ACTIVITY INTO THE EARLY MORNING HOURS WITH IFR RESTRICITONS POSSIBLE. WINDS THROUGH THE PERIOD WILL REMAIN WEST NORTHWESTERLY AND IN THE 5-8KTS RANGE THROUGH THE AFTERNOON MIXING HOURS. OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED INTO THE WEEKEND...WITH THE GREATEST COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF RECENT RAINFALL. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-14Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% MED 62% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JOH NEAR TERM...CDG/WIMBERLEY SHORT TERM...JOH LONG TERM...JOH AVIATION...CDG
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1059 AM CDT Fri Jun 20 2014 .UPDATE... A persistent area of showers remains across the southwestern part of West Central Texas (mainly the Northern Edwards Plateau) this morning. A small pocket of thunderstorms with very heavy rainfall (near the MCV) is beginning to shift north into southwestern Crockett County from Val Verde County. Based on radar and satellite trends, have increased PoPs considerably for the rest of this morning across our southwestern counties, and have increased cloud cover in the sky condition grids. Updated forecast products are forthcoming. 19 && .PREV DISCUSSION... /ISSUED 638 AM CDT FRI JUN 20 2014/ AVIATION... /12Z TAFS/ Widespread rain showers will continue for another few hours along the I-10 corridor, mainly affecting only KJCT and KSOA. However, given the proximity, VCSH was retained at KSJT and BBD. There may be some brief MVFR ceilings around 2500 ft this morning, but abundant mid/high level clouds have obscured the low clouds. This, combined with the overnight precipitation, will make ceilings very difficult to forecast. If ceilings develop, they will lift above VFR criterion by late morning. Isolated showers and thunderstorms are in the forecast for this afternoon, along and south of a line from KSJT to KBBD but coverage should be limited and including thunder in the TAFs would be overkill. Have decided to leave the forecast dry with diurnal cu dissipating around sunset. Low clouds were included at the southern terminals tonight, mainly after 09z. Johnson PREV DISCUSSION... /ISSUED 330 AM CDT FRI JUN 20 2014/ SHORT TERM... (Today and tonight) Showers, and a few thunderstorms, continue to drift to the north and northwest across the southern half of the CWA early this morning. This convection is the result of the enhanced lift associated with an MCV that has developed near Del Rio and persistent warm, moist inflow from a 30 kt low-level jet. The latest runs of the HRRR and the TTU WRF have caught on and continue this precipitation across the southwest quadrant of the CWA well into the morning hours before diminishing in areal coverage by midday. Rainfall totals have generally remain on the light side, but a few areas have seen amounts approaching 1". The RAWS station 10 miles south of Barnhart measured 0.91" in the past 2 hours. Additional showers and thunderstorms will be possible this afternoon, generally south of a Sterling City to San Saba line, however, coverage should be limited. The NAM and RAP point soundings indicate an uncapped environment and any residual outflow boundaries from this morning`s activity may help initiate diurnal storms. That said, we`ve had a very weak cap (at best) the past several days and diurnal convection has been . Thus, only isolated thunderstorms were mentioned for this afternoon. The increase in cloud cover and precipitation in the area will result in max temps a few degrees cooler than what we saw yesterday. Highs this afternoon should range from the mid 80s in the southwest to the lower 90s in the Big Country. We may again see nocturnal convection across the southwest portion of the CWA. The slight chance for precipitation was expanded slightly north and east to account for this potential. Overnight low temperatures will be near 70 degrees. LONG TERM... (Saturday through Thursday) This weekend an upper high over southeastern Texas will begin to weaken as an upper ridge builds into the area from the west. The forecast area will thus continue to be under a weak mid/upper level shear axis through Saturday with a chance of isolated thunderstorms developing over the western CWA during the day on Saturday and over the southern CWA Saturday night. As the western ridge continues to build over the area on Sunday the forecast area will come under a northwest flow aloft. Afternoon temperatures will warm from the upper 80s and lower 90s on Saturday to the lower to mid 90s on Sunday and a still little warmer on Monday. As an upper short wave moves east through the Central Plains on Tuesday it will push a weak cold into the northern Big Country by Tuesday morning. The frontal boundary will then stall but will provide a focus for the development of showers and thunderstorms over the Big Country beginning Monday night and through Tuesday night as periodic disturbances move southeast in the upper flow aloft. As the upper ridge continues to build over the western CONUS through midweek and eventually over the central CONUS by the end of the week, our forecast will be dry with afternoon highs generally in the mid to upper 90s and morning lows in the lower 70s. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 89 71 90 71 93 / 10 10 10 10 10 San Angelo 88 70 91 71 94 / 20 20 20 10 10 Junction 86 69 90 70 92 / 30 20 10 20 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
712 AM CDT FRI JUN 20 2014 .AVIATION... FOR THE 12Z TAFS...VFR CONDITIONS ARE EXPECTED THROUGH THE VALID FORECAST PERIOD. PERSISTENT...FLOODING THUNDERSTORM ACTIVITY NEAR DEL RIO HAS LEFT A BLANKET OF UPPER LEVEL CLOUD COVER OVER ALL TAF SITES EARLY THIS MORNING. WHILE THIS HAS NO EFFECT ON LANDING OR TAKING OFF...THIS CLOUD LAYER PROBABLY REPRESENTS SOME TURBULENCE AT TYPICAL CRUISING ALTITUDES BECAUSE IT WAS GENERATED BY THUNDERSTORM ACTIVITY. OTHERWISE...THERE WERE SOME SCATTERED MVFR HEIGHT CLOUDS AROUND CENTRAL TEXAS EARLY THIS MORNING...BUT NOTHING AROUND THE DFW AREA AS OF 12Z. AFTER A COUPLE OF HOURS OF HEATING...A FEW TO SCATTERED MVFR HEIGHT STRATOCUMULUS CLOUDS MAY DEVELOP. COVERAGE IS EXPECTED TO REMAIN SCATTERED AT BEST...SO VFR CONDITIONS SHOULD HOLD. OTHERWISE THE ONLY REAL CONCERN FOR AVIATION WEATHER IS THUNDERSTORM CHANCES. MOST MODEL GUIDANCE ADVERTISES MID-LEVEL SUBSIDENCE OVER AREA TAF SITES TODAY...SO HAVE NO MENTION OF THUNDERSTORMS IN THE FORECAST AT THIS TIME. WILL MONITOR AMDAR SOUNDINGS THROUGHOUT THE DAY TO MAKE SURE THAT THIS IS HAPPENING AS FORECAST AS THERE SHOULD BE TELL-TALE MID-LEVEL DRYING ASSOCIATED WITH THE SUBSIDENCE BY EARLY THIS AFTERNOON. CAVANAUGH && .PREV DISCUSSION... /ISSUED 312 AM CDT FRI JUN 20 2014/ UPPER LOW HAS MOVED TO SOUTHEASTERN MANITOBA...AND SHOULD START PINWHEELING NORTH DURING THE DAY. RIDGE IS CENTERED OVER SOUTHERN MISSISSIPPI VALLEY AND WILL SLOWLY SLIDE SOUTHWEST OVER NEXT COUPLE OF DAYS. PWATS ARE ON THE WAY DOWN...FROM NEAR 2 INCHES YESTERDAY TO ABOUT AN INCH AND A HALF TODAY. GUIDANCE IS STRUGGLING WITH THE FEATURES THAT WILL DEFINE TODAY/S WEATHER...FROM THE CURRENT CONVECTION IN SOUTHERN OKLAHOMA TO SEA BREEZE TYPE SHOWERS MOVING IN FROM THE COAST. AS I WRITE THIS...THE OKLAHOMA CONVECTION IS WEAKENING AND MAY BE GONE BY 7 AM...BUT WILL KEEP A SMALL AREA OF ISOLATED THUNDER NEAR THE RED RIVER THIS MORNING. HAVE ALSO ADDED ISOLATED THUNDER FOR THIS AFTERNOON IN SOUTH AND SOUTHEAST ZONES AS HRRR AND WRF ARW BOTH HINT AT SOME SEA BREEZE CONVECTION MAKING IT THAT FAR NORTH. ATMOSPHERE WILL CONTINUE TO DRY AND HAVE LEFT SATURDAY AND SUNDAY PRECIP FREE AS THE HIGH BUILDS CLOSER TO NORTH TX. BY MONDAY...WITH HIGH LOCATED IN MEXICO...A SERIES OF TROUGHS WILL MOVE ACROSS THE SOUTHERN PLAINS AND HAVE THUS CONTINUED WITH THE LOW POP CHANCES IN THE NORTH MONDAY AND TUESDAY...AND AREA WIDE WEDNESDAY THROUGH SATURDAY MORNING. OF INTEREST IN THE EXTENDED...BY WEDNESDAY THE ECMWF BUILDS AN UPPER TROUGH ORIENTED NORTH/SOUTH ACROSS TEXAS AND KEEPS IT IN PLACE THROUGH 240 HOURS. IF THIS STATIONARY TROUGH WOULD MATERIALIZE (THE GFS BUILDS IN A RIDGE WEST AND PUSHES THE TROUGH EAST) IT WOULD GIVE US PERIODS OF MUCH NEEDED PRECIP OVER A NUMBER OF DAYS. ECMWF PUSHES PWATS ABOVE 2 INCHES AT DFW WEDNESDAY AFTERNOON...BUT THE GFS LOOKS MUCH DRIER. ONE ANALOG THAT COMES TO MIND WOULD BE THE WIDESPREAD RAIN/FLOODING THAT OCCURRED IN JUNE 2007 WITH A SIMILAR TROUGH. AGAIN...THERE IS NO CONSENSUS ON THIS OCCURRING SO WE CAN ONLY LOOK FOR MORE AGREEMENT IN FUTURE GUIDANCE 84. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 94 75 94 75 93 / 10 10 10 5 10 WACO, TX 91 72 93 73 92 / 10 5 10 5 10 PARIS, TX 92 72 92 72 91 / 10 10 10 5 10 DENTON, TX 93 73 93 74 93 / 10 10 10 5 10 MCKINNEY, TX 93 73 94 73 92 / 10 10 10 5 10 DALLAS, TX 93 76 94 75 93 / 10 5 10 5 10 TERRELL, TX 95 73 96 73 92 / 10 5 10 5 10 CORSICANA, TX 91 73 92 73 91 / 10 5 10 5 10 TEMPLE, TX 90 72 92 72 91 / 10 5 10 5 10 MINERAL WELLS, TX 91 72 92 73 92 / 10 5 10 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
638 AM CDT FRI JUN 20 2014 .AVIATION... /12Z TAFS/ Widespread rain showers will continue for another few hours along the I-10 corridor, mainly affecting only KJCT and KSOA. However, given the proximity, VCSH was retained at KSJT and BBD. There may be some brief MVFR ceilings around 2500 ft this morning, but abundant mid/high level clouds have obscured the low clouds. This, combined with the overnight precipitation, will make ceilings very difficult to forecast. If ceilings develop, they will lift above VFR criterion by late morning. Isolated showers and thunderstorms are in the forecast for this afternoon, along and south of a line from KSJT to KBBD but coverage should be limited and including thunder in the TAFs would be overkill. Have decided to leave the forecast dry with diurnal cu dissipating around sunset. Low clouds were included at the southern terminals tonight, mainly after 09z. Johnson && .PREV DISCUSSION... /ISSUED 330 AM CDT FRI JUN 20 2014/ SHORT TERM... (Today and tonight) Showers, and a few thunderstorms, continue to drift to the north and northwest across the southern half of the CWA early this morning. This convection is the result of the enhanced lift associated with an MCV that has developed near Del Rio and persistent warm, moist inflow from a 30 kt low-level jet. The latest runs of the HRRR and the TTU WRF have caught on and continue this precipitation across the southwest quadrant of the CWA well into the morning hours before diminishing in areal coverage by midday. Rainfall totals have generally remain on the light side, but a few areas have seen amounts approaching 1". The RAWS station 10 miles south of Barnhart measured 0.91" in the past 2 hours. Additional showers and thunderstorms will be possible this afternoon, generally south of a Sterling City to San Saba line, however, coverage should be limited. The NAM and RAP point soundings indicate an uncapped environment and any residual outflow boundaries from this morning`s activity may help initiate diurnal storms. That said, we`ve had a very weak cap (at best) the past several days and diurnal convection has been . Thus, only isolated thunderstorms were mentioned for this afternoon. The increase in cloud cover and precipitation in the area will result in max temps a few degrees cooler than what we saw yesterday. Highs this afternoon should range from the mid 80s in the southwest to the lower 90s in the Big Country. We may again see nocturnal convection across the southwest portion of the CWA. The slight chance for precipitation was expanded slightly north and east to account for this potential. Overnight low temperatures will be near 70 degrees. Johnson LONG TERM... (Saturday through Thursday) This weekend an upper high over southeastern Texas will begin to weaken as an upper ridge builds into the area from the west. The forecast area will thus continue to be under a weak mid/upper level shear axis through Saturday with a chance of isolated thunderstorms developing over the western CWA during the day on Saturday and over the southern CWA Saturday night. As the western ridge continues to build over the area on Sunday the forecast area will come under a northwest flow aloft. Afternoon temperatures will warm from the upper 80s and lower 90s on Saturday to the lower to mid 90s on Sunday and a still little warmer on Monday. As an upper short wave moves east through the Central Plains on Tuesday it will push a weak cold into the northern Big Country by Tuesday morning. The frontal boundary will then stall but will provide a focus for the development of showers and thunderstorms over the Big Country beginning Monday night and through Tuesday night as periodic disturbances move southeast in the upper flow aloft. As the upper ridge continues to build over the western CONUS through midweek and eventually over the central CONUS by the end of the week, our forecast will be dry with afternoon highs generally in the mid to upper 90s and morning lows in the lower 70s. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 89 71 90 71 93 / 10 10 10 10 10 San Angelo 88 70 91 71 94 / 20 20 20 10 10 Junction 86 69 90 70 92 / 30 20 10 20 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 25
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1054 AM EDT FRI JUN 20 2014 .SYNOPSIS... A WARM FRONT TRAILED FROM MINNESOTA TO KENTUCKY THIS MORNING. THIS FRONT WILL LIFT NORTHEAST INTO THE AREA TODAY. LOW PRESSURE WILL MOVE ALONG THIS FRONT...THROUGH THE OHIO VALLEY TONIGHT...THEN INTO VIRGINIA ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1040 AM EDT FRIDAY... A WARM FRONT REMAINS OVER THE FORECAST AREA THIS MORNING AND WILL TRACK SLOWLY TO THE NORTHEAST TODAY. THIS WARM FRONT IS ORIENTEDFROM NW TO SE AND IS PRODUCING SCATTERED SHOWERS FROM RICHLANDS AND ACROSS THE MOUNTAIN EMPIRE THIS MORNING. THESE STORMS WILL CONTINUE TO TRACK NW TO SE THROUGH THE AFTERNOON. AS THE WARM FRONT SHIFTS NORTH...SCATTERED SHOWER ACTIVITY WILL ALSO ADVANCE NORTH ACROSS THE AREA. MODEST CAPE VALUES ARE CURRENTLY BEING HELD DOWN WITH MORNING CLOUD COVER. THIS CLOUD COVER WILL THIN OUT THROUGH THE DAY...WHICH WILL THEN INCREASE INSTABILITIES AS HEATING IS MAXIMIZED. VERTICAL SHEAR IS MARGINAL BUT INSTABILITIES WILL BE ENOUGH TO PRODUCE A FEW STRONG TO SEVERE MULTICELLAR STORMS THIS AFTERNOON AND INTO THIS EVENING. CONVECTION WILL FADE SOME WITH LOSE OF HEATING BUT ONLY TO GIVE WAY TO A MESOSCALE SYSTEM ENTERING THE AREA FROM THE OHIO VALLEY LATER TONIGHT. AS OF 400 AM EDT FRIDAY... WARM FRONT...MAINLY INDICATED AROUND 850 MB...ACROSS THE OHIO VALLEY WILL BRING SOME WARM AIR ADVECTION AND KEEP DEEPER MOISTURE IN THE AREA TODAY. AGAIN EXPECTING SCATTERED THUNDERSTORMS THIS AFTERNOON. SIMILAR TO THURSDAY...HIGH CLOUDS WILL CUT BACK ON HEATING IN THE MORNING AND THEREFORE THE AMOUNT OF INSTABILITY IN THE AFTERNOON. STILL ENOUGH CAPE...FORECAST TO BE AROUND 1500 J/KG...FOR A THREAT OF STRONGER THUNDERSTORMS BEFORE 00Z/8PM. HRRR BRINGS PRECIPITATION IN TO THE FORECAST AROUND 17Z/1PM. MODELS HAVE BEEN TRENDED COOLER WITH MAXIMUM TEMPERATURES FOR TODAY. HIGH WILL DEPEND ON HOW MUCH HIGH CLOUDS FROM THIS MORNING CAN ERODE BEFORE THUNDERSTORMS DEVELOP. SHORT WAVE OVER ILLINOIS AND INDIANA WILL MOVE SOUTHEAST...REACHING WESTERN PARTS OF THE FORECAST AREA JUST AFTER 00Z AND SLOWLY MOVING ACROSS THE COUNTY WARNING AREA OVERNIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION TONIGHT WITH HIGHEST PROBABILITY AFTER MIDNIGHT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... AS OF 320 AM EDT FRIDAY... LOW PRESSURE WILL TRACK SOUTHEAST FROM NORTHERN WEST VIRGINIA SATURDAY MORNING AND REACHES EASTERN VIRGINIA BY SATURDAY AFTERNOON. THE NAM...GFS AND ECMWF SUPPORT GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS SATURDAY AS DISTURBANCE TRACKS EASTWARD ALONG THE THETA-E BOUNDARY. INCREASED POPS FOR SATURDAY ESPECIALLY SATURDAY MORNING. SPC SWODY2 HAS PLACED THE SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL PLAINS WITH A SEE TEXT IN EASTERN CAROLINAS. WITH ADDITIONAL CLOUD COVER AND PRECIPITATION SATURDAY...LOWERED HIGH TEMPERATURES WITH READINGS FROM THE UPPER 70S IN THE MOUNTAINS TO UPPER 80S IN THE PIEDMONT. AFTER THE DISTURBANCE EXITS THE AREA SATURDAY EVENING...A SLIGHT COOLER AND DRY AIRMASS WILL TEMPORARY BUILD OVER THE REGION SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL RANGE FROM AROUND 60 DEGREES IN THE WEST TO THE MID 60S IN THE EAST. SFC HIGH PRESSURE PROGGED TO BE CENTERED EAST SOUTHEAST OF NEW ENGLAND ON SUNDAY...AND SLOWLY BUILDS SOUTHWARD. DECREASED POPS FOR SUNDAY AS A NORTHERLY FLOW AND LESS INSTABILITIES SHOULD LEAD TO LESS CONVECTION. WITH CAUTION...HELD ON TO SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE GFS WAS MORE ROBUST WITH CONVECTION COMPARED TO ECMWF AND NAM FOR SUNDAY. WENT WITH HIGH TEMPERATURES SUNDAY FROM THE UPPER 70S IN THE MOUNTAINS TO THE MID 80S IN THE PIEDMONT. SOUTHEASTERLY FLOW OVERNIGHT SUNDAY MAY KEEP A FEW SHOWERS ONGOING INTO EARLY MONDAY MORNING. THE BEST CHANCE FOR SHOWERS SUNDAY NIGHT WILL OCCUR ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS. LOWS SUNDAY NIGHT WILL GENERALLY BE IN THE 60S. LEANED TOWARDS HPCGUIDE FOR MONDAY WITH PULSE STORM AND THE PRIMARY FOCUS FOR CONVECTION ACROSS THE MOUNTAINS. TAPER OFF SCATTERED STORMS TO ISOLATED SHOWERS MONDAY NIGHT. && .LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... TUESDAY COULD BE A MIX OF CONVECTION FROM PULSE STORMS IN THE EARLY AFTERNOON TRANSITIONING TO PREFRONTAL CONVECTION IN THE EARLY EVENING THROUGH THE EARLY MORNING HOURS. ON WEDNESDAY...A COLD FRONT WILL SLIDE ACROSS THE REGION WITH THE BEST AREAL COVERAGE OF THE STRONGER STORMS BEING ACROSS THE PIEDMONT. THE COLD FRONT MAY WASHOUT OR STALL WITH THE DEW POINT FRONT HANGING BACK ACROSS THE OHIO VALLEY. UNDER HEATING...SCATTERED CONVECTION MAY FIRE AGAIN ACROSS THE AREA THURSDAY ESPECIALLY ALONG AND SOUTH OF THE VA/NC BORDER. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... AS OF 735 AM EDT FRIDAY... PATCHES MVFR TO IFR CLOUDS WILL LIFT THIS MORNING WITH ALL TAF SITES VFR BY 14Z/10AM. ENOUGH HEATING AND DECENT INSTABILITY BY NOON/16Z FOR SHOWERS AND THUNDERSTORMS TO DEVELOP AS A WARM FRONT MOVES INTO THE AREA FROM THE OHIO VALLEY. A STRONGER SHORT WAVE WILL REACH THE FORECAST AREA TONIGHT. HAVE KEPT CEILINGS VFR AT KROA/KBCB AND KDAN WITH SHOWERS...MAINLY AFTER 02Z/10PM. MODERATE CONFIDENCE OF MVFR CEILINGS FOR KLYH/KLWB/KBLF WITH A PROLONGED PERIOD OF SHOWERS AND EMBEDDED THUNDERSTORMS OVERNIGHT. EXTENDED AVIATION DISCUSSION... A WEAK FLOW PATTERN HOLDING OVER THE WEEKEND WILL KEEP THE STORM CHANCES EACH AFTERNOON THROUGH EARLY EVENING SAT/SUN BUT COVERAGE FOR NOW LOOKS A BIT LESS EACH DAY BEHIND THE PASSING IMPULSE FROM FRIDAY NIGHT. DEEPER MOISTURE LOOKS TO RETURN NORTH BY EARLY NEXT WEEK WITH BETTER COVERAGE OF AFTERNOON/EVENING STORMS ON MONDAY. AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING... PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE AFTERNOON CONVECTION REDEVELOPS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/RCS SHORT TERM...KK LONG TERM...RCS AVIATION...AMS/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
740 AM EDT FRI JUN 20 2014 .SYNOPSIS... A WARM FRONT TRAILED FROM MINNESOTA TO KENTUCKY THIS MORNING. THIS FRONT WILL LIFT NORTHEAST INTO THE AREA TODAY. LOW PRESSURE WILL MOVE ALONG THIS FRONT...THROUGH THE OHIO VALLEY TONIGHT...THEN INTO VIRGINIA ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT FRIDAY... WARM FRONT...MAINLY INDICATED AROUND 850 MB...ACROSS THE OHIO VALLEY WILL BRING SOME WARM AIR ADVECTION AND KEEP DEEPER MOISTURE IN THE AREA TODAY. AGAIN EXPECTING SCATTERED THUNDERSTORMS THIS AFTERNOON. SIMILAR TO THURSDAY...HIGH CLOUDS WILL CUT BACK ON HEATING IN THE MORNING AND THEREFORE THE AMOUNT OF INSTABILITY IN THE AFTERNOON. STILL ENOUGH CAPE...FORECAST TO BE AROUND 1500 J/KG...FOR A THREAT OF STRONGER THUNDERSTORMS BEFORE 00Z/8PM. HRRR BRINGS PRECIPITATION IN TO THE FORECAST AROUND 17Z/1PM. MODELS HAVE BEEN TRENDED COOLER WITH MAXIMUM TEMPERATURES FOR TODAY. HIGH WILL DEPEND ON HOW MUCH HIGH CLOUDS FROM THIS MORNING CAN ERODE BEFORE THUNDERSTORMS DEVELOP. SHORT WAVE OVER ILLINOIS AND INDIANA WILL MOVE SOUTHEAST...REACHING WESTERN PARTS OF THE FORECAST AREA JUST AFTER 00Z AND SLOWLY MOVING ACROSS THE COUNTY WARNING AREA OVERNIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION TONIGHT WITH HIGHEST PROBABILITY AFTER MIDNIGHT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... AS OF 320 AM EDT FRIDAY... LOW PRESSURE WILL TRACK SOUTHEAST FROM NORTHERN WEST VIRGINIA SATURDAY MORNING AND REACHES EASTERN VIRGINIA BY SATURDAY AFTERNOON. THE NAM...GFS AND ECMWF SUPPORT GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS SATURDAY AS DISTURBANCE TRACKS EASTWARD ALONG THE THETA-E BOUNDARY. INCREASED POPS FOR SATURDAY ESPECIALLY SATURDAY MORNING. SPC SWODY2 HAS PLACED THE SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL PLAINS WITH A SEE TEXT IN EASTERN CAROLINAS. WITH ADDITIONAL CLOUD COVER AND PRECIPITATION SATURDAY...LOWERED HIGH TEMPERATURES WITH READINGS FROM THE UPPER 70S IN THE MOUNTAINS TO UPPER 80S IN THE PIEDMONT. AFTER THE DISTURBANCE EXITS THE AREA SATURDAY EVENING...A SLIGHT COOLER AND DRY AIRMASS WILL TEMPORARY BUILD OVER THE REGION SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL RANGE FROM AROUND 60 DEGREES IN THE WEST TO THE MID 60S IN THE EAST. SFC HIGH PRESSURE PROGGED TO BE CENTERED EAST SOUTHEAST OF NEW ENGLAND ON SUNDAY...AND SLOWLY BUILDS SOUTHWARD. DECREASED POPS FOR SUNDAY AS A NORTHERLY FLOW AND LESS INSTABILITIES SHOULD LEAD TO LESS CONVECTION. WITH CAUTION...HELD ON TO SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE GFS WAS MORE ROBUST WITH CONVECTION COMPARED TO ECMWF AND NAM FOR SUNDAY. WENT WITH HIGH TEMPERATURES SUNDAY FROM THE UPPER 70S IN THE MOUNTAINS TO THE MID 80S IN THE PIEDMONT. SOUTHEASTERLY FLOW OVERNIGHT SUNDAY MAY KEEP A FEW SHOWERS ONGOING INTO EARLY MONDAY MORNING. THE BEST CHANCE FOR SHOWERS SUNDAY NIGHT WILL OCCUR ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS. LOWS SUNDAY NIGHT WILL GENERALLY BE IN THE 60S. LEANED TOWARDS HPCGUIDE FOR MONDAY WITH PULSE STORM AND THE PRIMARY FOCUS FOR CONVECTION ACROSS THE MOUNTAINS. TAPER OFF SCATTERED STORMS TO ISOLATED SHOWERS MONDAY NIGHT. && .LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... TUESDAY COULD BE A MIX OF CONVECTION FROM PULSE STORMS IN THE EARLY AFTERNOON TRANSITIONING TO PREFRONTAL CONVECTION IN THE EARLY EVENING THROUGH THE EARLY MORNING HOURS. ON WEDNESDAY...A COLD FRONT WILL SLIDE ACROSS THE REGION WITH THE BEST AREAL COVERAGE OF THE STRONGER STORMS BEING ACROSS THE PIEDMONT. THE COLD FRONT MAY WASHOUT OR STALL WITH THE DEW POINT FRONT HANGING BACK ACROSS THE OHIO VALLEY. UNDER HEATING...SCATTERED CONVECTION MAY FIRE AGAIN ACROSS THE AREA THURSDAY ESPECIALLY ALONG AND SOUTH OF THE VA/NC BORDER. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 735 AM EDT FRIDAY... PATCHES MVFR TO IFR CLOUDS WILL LIFT THIS MORNING WITH ALL TAF SITES VFR BY 14Z/10AM. ENOUGH HEATING AND DECENT INSTABILITY BY NOON/16Z FOR SHOWERS AND THUNDERSTORMS TO DEVELOP AS A WARM FRONT MOVES INTO THE AREA FROM THE OHIO VALLEY. A STRONGER SHORT WAVE WILL REACH THE FORECAST AREA TONIGHT. HAVE KEPT CEILINGS VFR AT KROA/KBCB AND KDAN WITH SHOWERS...MAINLY AFTER 02Z/10PM. MODERATE CONFIDENCE OF MVFR CEILINGS FOR KLYH/KLWB/KBLF WITH A PROLONGED PERIOD OF SHOWERS AND EMBEDDED THUNDERSTORMS OVERNIGHT. EXTENDED AVIATION DISCUSSION... A WEAK FLOW PATTERN HOLDING OVER THE WEEKEND WILL KEEP THE STORM CHANCES EACH AFTERNOON THROUGH EARLY EVENING SAT/SUN BUT COVERAGE FOR NOW LOOKS A BIT LESS EACH DAY BEHIND THE PASSING IMPULSE FROM FRIDAY NIGHT. DEEPER MOISTURE LOOKS TO RETURN NORTH BY EARLY NEXT WEEK WITH BETTER COVERAGE OF AFTERNOON/EVENING STORMS ON MONDAY. AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING... PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE AFTERNOON CONVECTION REDEVELOPS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...RCS AVIATION...AMS/PM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1058 AM CDT FRI JUN 20 2014 .UPDATE... ISSUED AT 1058 AM CDT FRI JUN 20 2014 ADDED A SLIGHT CHANCE FOR SHOWERS/STORMS ACROSS NORTH CENTRAL WISCONSIN FOR THIS AFTERNOON. THE PAST FEW RUNS OF THE HRRR HAVE INITIATED SOME WEAK CONVECTION IN EASTERN TO NORTH CENTRAL WISCONSIN ALONG A BOUNDARY THAT CURRENTLY RESIDES IN THAT AREA. 20.13Z RAP SOUNDINGS FROM NECEDAH SHOWS THAT THE ATMOSPHERE REMAINS CAPPED OFF...BUT ITS SURFACE DEW POINT MAY BE A TAD DRY COMPARED TO WHAT THE HRRR HAS. REGARDLESS...SAW ENOUGH TO WARRANT SOME SMALL CHANCES FOR SHOWERS/STORMS IN THIS AREA. OTHERWISE...THE CLOUD SHIELD WILL CLEAR FROM THE WEST TODAY AND PROVIDE A FAIRLY WARM DAY WITH TEMPERATURES CLIMBED UP INTO THE 80S. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 342 AM CDT FRI JUN 20 2014 THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TONIGHT THROUGH SUNDAY. LOCAL AND REGIONAL RADARS THIS MORNING SHOWING MOST OF THE SHOWERS THIS MORNING WERE OVER THE NORTHERN AND EASTERN SECTIONS OF WISCONSIN WITH JUST SOME WIDELY SCATTERED ACTIVITY OVER THE CENTRAL PART OF THE STATE. THESE SHOWERS WERE MOVING OFF TO THE NORTH/NORTHEAST AND THE 20.05Z HRRR SUGGESTS THESE SHOULD MOVE OUT OF THE FORECAST AREA BY 12Z. WILL MONITOR THE RADAR TRENDS BUT MAY HAVE TO START THE MORNING WITH A VERY SMALL RAIN CHANCE ACROSS THE FAR NORTHERN AND EASTERN PARTS OF THE FORECAST AREA WITH ANY REMAINING SHOWERS EXPECTED TO BE COMPLETELY OUT OF THE AREA BY MID MORNING. THE UPPER LEVEL LOW OVER SASKATCHEWAN WILL LIFT SLOWLY NORTHEAST THROUGH TONIGHT AND BECOME AN OPEN WAVE OVER SOUTHERN MANITOBA AND WESTERN ONTARIO ALLOWING THE FLOW OVER THE UPPER MIDWEST TO BECOME ZONAL. ONE SHORT WAVE TROUGH ROUNDING THE REMAINS OF THIS UPPER LEVEL LOW IS EXPECTED TO MOVE ACROSS NORTHERN MINNESOTA TONIGHT WITH ANOTHER WEAKER WAVE COMING OUT OF THE ROCKIES AND ACROSS NEBRASKA AND SOUTHERN IOWA. NOT A LOT OF PV ADVECTION WITH EITHER OF THESE WAVES...BUT ENOUGH WARM AIR ADVECTION SHOULD OCCUR TO PRODUCE 4 TO 6 UBAR/S OF UP GLIDE ON THE 305K ISENTROPIC SURFACE. THE MODELS ARE SPLIT ON HOW MUCH AND WHERE THE MOISTURE TRANSPORT WILL BE WITH THESE WAVES. THE 20.00Z NAM SUGGESTS WEAK TRANSPORT SHOULD OCCUR AHEAD OF THE NORTHERN WAVE INTO NORTHERN WISCONSIN AND MINNESOTA WHILE THE 20.00Z GFS AND ECMWF HAVE THE MOISTURE TRANSPORT AHEAD OF THE SOUTHERN WAVE INTO NEBRASKA WHERE THEY DEVELOP A CONVECTIVE COMPLEX. THE GFS THEN KEEPS THIS COMPLEX GENERALLY SOUTH OF THE AREA WHILE THE ECMWF BRINGS INTO THE THE AREA. THE 20.03Z SREF PROBABILITIES TEND TO FAVOR THE GFS SOLUTION WITH THE CONVECTIVE COMPLEX BUT ALSO HAVE SOME LOW PROBABILITIES ACROSS THE NORTH SIMILAR TO THE NAM. WITH SUCH WEAK FORCING SIGNALS AND DIFFERING MODEL SOLUTIONS...WILL JUST HAVE SOME LOW RAIN CHANCES ACROSS MOST THE AREA FOR THE OVERNIGHT HOURS. THE ZONAL FLOW CONTINUES INTO SATURDAY WITH ALL THE MODELS SHOWING ANOTHER WEAK WAVE COMING ACROSS THE NORTHERN ROCKIES INTO THE UPPER MIDWEST. THE GFS IS THE FARTHEST NORTH BRINGING THIS ACROSS MINNESOTA INTO IOWA WHILE THE NAM AND ECMWF TAKE IT ACROSS IOWA. THIS RESULTS IN BIG DIFFERENCES IN HOW MUCH AND WHERE THE RAIN COULD FALL. THE NAM AND ECMWF KEEP THE MAJORITY OF THE RAIN TO THE SOUTH OF THE AREA WHILE THE GFS WOULD INDICATE ALL OF THE FORECAST AREA WOULD HAVE A CHANCE FOR GETTING WET. AGAIN...THE SREF PROBABILITIES FAVOR THE NAM AND ECMWF SOLUTIONS SO PLAN TO SHOW 20 TO 30 PERCENT CHANCES THROUGH THE DAY WITH THESE HIGHEST ACROSS THE SOUTH. THE RAIN THAT DEVELOPS SATURDAY SHOULD CONTINUE ACROSS THE SOUTH INTO SATURDAY EVENING BEFORE STARTING TO MOVE OFF TO THE EAST SATURDAY NIGHT. A STRONGER SHORT WAVE TROUGH IS EXPECTED TO MOVE OUT OF THE ROCKIES AND START TO APPROACH THE AREA SUNDAY. THE PV ADVECTION IN THE 500-300 MB LAYER WILL STAY TO THE WEST OF THE AREA. THE ISENTROPIC UP GLIDE AHEAD OF THIS WAVE SHOULD MOVE INTO THE WESTERN SECTIONS OF IOWA AND MINNESOTA BY LATE IN THE DAY SUNDAY. IF THE MODELS REMAIN CONSISTENT WITH THESE SIGNALS...THE BEST RAIN CHANCES SHOULD BE CONFINED TO THE WESTERN SECTIONS OF THE FORECAST AREA AND THE EASTERN SECTIONS COULD BE DRY...BUT WITH THE GFS BEING QUICKER TO MOVE THIS SYSTEM IN...WILL SHOW A 30 TO 40 PERCENT CHANCE FROM EAST TO WEST. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 AM CDT FRI JUN 20 2014 THE MODEL DIFFERENCE CONTINUE INTO EARLY NEXT WEEK AS WELL. GENERAL CONSENSUS THAT THE SHORT WAVE TROUGH THAT COMES OUT SUNDAY WILL WEAKEN AS IT MOVES TOWARD MINNESOTA IN FAVOR OF ANOTHER WAVE COMING ACROSS NEBRASKA OR KANSAS. THE ECMWF THEN TAKES THIS WAVE NORTHEAST AND INTO THE GREAT LAKES REGION THROUGH MONDAY WHILE THE GFS AMPLIFIES THIS FORMING AN UPPER LEVEL LOW OVER THE UPPER MIDWEST MONDAY NIGHT WITH THE 20.00Z GEM DOING SOMETHING VERY SIMILAR. BOTH THE ECMWF AND GFS THEN SHOW WEAK RIDGING BUILDING OVER THE UPPER MIDWEST BY THE END OF PERIOD WITH THE ECMWF QUICKER TO DO THIS THAN THE GFS. BECAUSE OF THE DIFFERENCES BETWEEN THE MODELS...WILL HAVE SOME RAIN CHANCES THROUGH THE ENTIRE PERIOD WITH THE HIGHEST CHANCES MONDAY INTO MONDAY NIGHT WHEN THE FORCING FROM THE WAVE SHOULD BE THE STRONGEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 656 AM CDT FRI JUN 20 2014 AREAS OF FOG AND STRATUS WILL PRODUCE LIFR CONDITIONS AT KRST THROUGH 13Z. MVFR CONDITIONS ARE EXPECTED AT KLSE THROUGH 13Z. HIGH PRESSURE WILL THEN BUILD INTO THE REGION TODAY WITH VFR CONDITIONS EXPECTED. LOOKING AT THE FORECAST SOUNDINGS...THINKING SCATTERED TO BROKEN CUMULUS WILL DEVELOP LATE THIS MORNING BUT THEN SHOULD GRADUALLY FLATTEN AND DISSIPATE DURING THE AFTERNOON HOURS AS DRIER AIR MOVES IN. A WEAK SYSTEM THEN APPROACHES FROM THE PLAINS TONIGHT WITH INCREASING CLOUDS EXPECTED. && .HYDROLOGY... ISSUED AT 342 AM CDT FRI JUN 20 2014 WITH ALL THE RECENT RAINS...NUMEROUS RIVERS AND STREAMS HAVE FLOODING ALONG THEM RESULTING IN AREAL AND RIVER FLOOD WARNINGS. WITH A DRY DAY TODAY...SOME OF THE WATER MAY RECEDE ENOUGH TO ALLOW THE AREAL FLOOD WARNINGS TO BE DISCONTINUED OR MADE SMALLER IN SIZE. HOWEVER...MANY OF THE RIVERS WILL REMAIN ABOVE FLOOD STAGE INTO THE WEEKEND. WHILE ADDITIONAL RAINFALL IS IN THE FORECAST THROUGH THE WEEKEND...EXPECTED AMOUNTS AT THIS TIME SHOULD NOT BE ENOUGH TO AGGRAVATE EXISTING FLOODING PROBLEMS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...HALBACH SHORT TERM...04 LONG TERM...04 AVIATION...WETENKAMP HYDROLOGY...04
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1011 AM CDT FRI JUN 20 2014 .UPDATE... AREA OF RAIN IS CURRENTLY EXITING THE NORTHEAST FORECAST AREA...WITH DRY WEATHER EXPECTED FOR THE REMAINDER OF THE DAY AFTER THIS RAIN MOVES OUT. THERE COULD BE SOME LATE MORNING AND AFTERNOON BREAKS IN THE CLOUDS...BUT OTHERWISE EXPECT MOSTLY CLOUDY CONDITIONS FOR MUCH OF THE DAY. OCCASIONAL FOG NEAR LAKE MICHIGAN SHOULD ALSO IMPROVE THROUGH THE DAY. HIGH TEMPERATURES IN THE EAST MAY NEED TO BE LOWERED A BIT WITH ONSHORE WINDS LIKELY PERSISTING INTO THE AFTERNOON. && .AVIATION/18Z TAFS/... CIGS ARE SHOWING SOME SIGNS OF IMPROVEMENT IN THE WEST...BUT LATEST MODEL SOUNDINGS SHOW CIGS MAY NOT GET ABOVE MVFR THROUGH THE AFTERNOON. WILL HAVE TO CONTINUE TO EVALUATE UPSTREAM CIGS AND LATEST MODEL DATA FOR THIS EVENING AND OVERNIGHT...AS THERE ARE MIXED SIGNALS WITH CLOUD COVER TONIGHT. THE NAM IS SUGGESTING SOME LOW STRATUS POSSIBLE...WHILE THE GFS BRINGS VFR CONDITIONS THROUGH THE NIGHT. OCCASIONAL FOG NEAR LAKE MICHIGAN SHOULD IMPROVE THROUGH THE DAY TODAY. AFTER THE AREA OF RAIN IN THE NORTHEAST MOVES OUT LATE THIS MORNING...COULD SEE A FEW SHOWERS TONIGHT INTO SATURDAY MORNING...WITH A CHANCE FOR SHOWERS AND STORMS IN THE AFTERNOON. OTHER THAN SOME LOWER CIGS/VSBYS WITHIN AREAS OF SHOWERS/STORMS...LOOKS LIKE MAINLY VFR CONDITIONS FOR SATURDAY. && .PREV DISCUSSION... /ISSUED 447 AM CDT FRI JUN 20 2014/ TODAY...FORECAST CONFIDENCE IS MEDIUM. CURRENT BAND OF LIGHT SHOWERS BEING DRIVEN BY IMPULSE ROTATING AROUND EASTERN FLANK OF CLOSED 500 MB LOW WATER VAPOR IMAGERY SHOWS MOVING EAST ALONG THE U.S./CANADIAN BORDER OVER NORTHEAST MONTANA/SASKATCHEWAN. THE IMPULSE...AND THE WEAK SURFACE REFLECTION OF THIS IMPULSE...CROSS SRN WI THIS MORNING REACHING THE FAR SE CORNER OF WI/NE IL BY 18Z. CURRENT TIMING PUSHES PCPN EAST OF STATE BY 15Z AT THE LATEST...BUT SOME CONCERN ABOUT LOW LEVEL CONVERGENCE/FRONTOGENETIC RESPONSE IN THE EAST BEHIND LOW. MODEL SOUNDINGS SHOW THE COLUMN DRYING BEHIND THIS IMPULSE...NO DOUBT AIDED BY SUBSIDENCE ASSOCIATED WITH UPPER LEVEL CONVERGENCE IN RIGHT EXIT REGION OF UPPER JETLET ON SRN EDGE OF THE CLOSED UPPER LOW THAT SPREADS ACROSS SRN WI LATE THIS MORNING/AFTERNOON. HOWEVER CONCERN ABOUT THE INCREASING CAPE VALUES AND STEEP LOW- LEVEL LAPSE RATES WITH DAYTIME HEATING. WILL NOT HAVE POPS IN THE EAST PAST 20Z BUT LATEST HRRR DOES SHOW SOME SCATTERED PCPN IN CONVERGENCE FARTHER INLAND. TONIGHT...FORECAST CONFIDENCE IS MEDIUM. MOST OF THE NIGHT IS QUIET...BUT NEAR ZONAL FLOW BRINGS A WEAK SHORT WAVE TOWARD THE REGION BY 12Z SATURDAY. WILL LIMIT SLIGHT CHANCE POPS TO THE FAR NORTHWEST WITH LOW EXPECTATION OF ANYTHING MEASURABLE AS LIMITED MOISTURE AVAILABLE MAINLY IN THE MID LEVELS. SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. SHORT TERM MODELS GENERALLY SHOWING A MESOSCALE CONVECTIVE SYSTEM SHIFTING FROM NORTHERN IOWA TO SOUTHEAST IOWA AND NORTHERN ILLINOIS SATURDAY AND SATURDAY NIGHT. SOME VARIATION IN THE TRACK OF THIS FEATURE. MODELS ALSO TRYING TO GENERATE QPF WITHIN WEAK WARM AIR ADVECTION REGIME AND MOIST/UNSTABLE AIRMASS. WEAK LOW LEVEL FRONTOGENESIS RESPONSE ALSO SEEN IN THE AREA. NAM/GFS DIFFER ON MEAN LAYER CAPES...BUT ADJUSTING TEMPERATURE/DEW POINTS IN LOWEST 100 MB MEAN LAYER SUGGESTS 1000 TO 1500 J/KG AT LEAST. NAM CAPPED WITH GFS MOSTLY UNCAPPED SATURDAY...WITH NAM LOSING INSTABILITY SATURDAY NIGHT. DEEP LAYER SHEAR IS MODEST SATURDAY ON NAM...WEAK ON GFS. BOTH ARE WEAK WITH SHEAR SATURDAY NIGHT. FOR NOW...CONTINUED POPS FOR THIS PERIOD. NO ALL DAY RAINFALL IS EXPECTED AT THIS TIME. WARM AND HUMID CONDITIONS WILL CONTINUE AWAY FROM LAKE MICHIGAN. MODELS DIFFER MORE WITH SUNDAY AND SUNDAY NIGHT...AS NAM/ECMWF/CANADIAN MODELS ARE FAIRLY DRY WITH INFLUENCE OF HIGH PRESSURE TO THE NORTHEAST OF THE REGION. GFS CONTINUES TO HAVE WEAK WARM AIR ADVECTION AND QPF WITHIN MOIST/UNSTABLE AIRMASS...WITH NAM SHOWING MORE ELEVATED CAPE PROFILES. FOR NOW...WILL CONTINUE CHANCE POPS FOR THIS PERIOD. MAY HAVE TO RAMP DOWN POPS IN LATER FORECASTS IF DRIER LOOK CONTINUES ON NAM/ECMWF/CANADIAN MODELS. WARM AND HUMID AGAIN AWAY FROM THE LAKE ON SUNDAY. LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS MEDIUM. ECMWF/GFS BRING LOW PRESSURE NORTHEAST THROUGH THE REGION MONDAY INTO EARLY TUESDAY...ALONG WITH A COLD FRONT AND 500 MB SHORTWAVE TROUGH. THIS SHOULD RESULT IN DECENT CHANCES FOR SHOWERS AND THUNDERSTORMS. CONTINUED HIGHER END POPS FOR MONDAY AND MONDAY NIGHT...SLIGHTLY LOWER ON TUESDAY. WARM AND HUMID CONDITIONS SHOULD CONTINUE. A BIT MORE UNCERTAINTY FURTHER OUT IN THE FORECAST...SO WILL USE CONSENSUS POPS AND TEMPERATURES FOR THIS PERIOD. IT APPEARS THAT A COOLER AND LESS HUMID AIRMASS MAY MOVE INTO THE REGION AFTER THE COLD FRONTAL PASSAGE TUESDAY...AND PERHAPS A DRY PERIOD WITH HIGH PRESSURE. SOME QPF OCCURS FROM TIME TO TIME...SO NOT SOLD ON A DRY FORECAST JUST YET. AVIATION/12Z TAFS/...PER WESTERN OBSERVATIONS LIFR CIGS EXPECTED TO LIFT TO MVFR AFTER PASSAGE OF LAST POCKET OF SHOWERS CROSSES REGION EARLY THIS MORNING. VSBYS ARE ANOTHER QUESTION AS A BREAK IN THE LOWER CIGS HAS ALLOWED ENOUGH COOLING FOR 1/2 TO 1/4 MILE VSBYS AT KUGN AND KENW. DENSE FOG HAS FORMED WHERE SKIES CLEARED IN IOWA. WILL WATCH CLOSELY BUT EXPECT PREVAILING VSBYS TO HOLD BETWEEN 1 AND 2 MILES...THEN IMPROVE AFTER DAYBREAK AND PASSAGE OF THE LAST OF THE RAIN SHOWERS. WILL KEEP CIGS AT MVFR LEVELS UNTIL EARLY AFTERNOON THEN VFR CONDITIONS WHEN DRIER AIR MOVES IN BEHIND WEAK SURFACE LOW. LIGHT WINDS AND MOIST CONDITIONS BRING A GOOD POTENTIAL OF FOG TONIGHT. SREF PROBABILITIES FOR LESS THAN 3 MILE VSBYS JUMP UP AFTER 06Z...WITH LESS THAN 1 MILE CHANCES FOCUSED NEAR KBUU AND KENW. WILL HOLD VSBYS AT MVFR LEVELS EXCEPT AT KENW WITH IFR BETWEEN 09Z AND 12Z. MARINE...CURRENT WEB CAMS NOT SHOWING FOG ALONG THE IMMEDIATE SHORE BUT APPEARS TO BE SOME OFFSHORE FOG. WILL KEEP MENTION OF AREAS OF FOG THROUGH THE DAY UNTIL NORTHEAST WINDS LATER THIS AFTERNOON SCOUR OUT HIGHER DEW POINT AIR OVER THE LAKE. POTENTIAL FOR FOG RETURNS WITH HIGHER DEW POINTS SATURDAY AHEAD OF NEXT WEAK SYSTEM. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DDV TODAY/TONIGHT AND AVIATION/MARINE...REM SATURDAY THROUGH THURSDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
656 AM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 342 AM CDT FRI JUN 20 2014 THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TONIGHT THROUGH SUNDAY. LOCAL AND REGIONAL RADARS THIS MORNING SHOWING MOST OF THE SHOWERS THIS MORNING WERE OVER THE NORTHERN AND EASTERN SECTIONS OF WISCONSIN WITH JUST SOME WIDELY SCATTERED ACTIVITY OVER THE CENTRAL PART OF THE STATE. THESE SHOWERS WERE MOVING OFF TO THE NORTH/NORTHEAST AND THE 20.05Z HRRR SUGGESTS THESE SHOULD MOVE OUT OF THE FORECAST AREA BY 12Z. WILL MONITOR THE RADAR TRENDS BUT MAY HAVE TO START THE MORNING WITH A VERY SMALL RAIN CHANCE ACROSS THE FAR NORTHERN AND EASTERN PARTS OF THE FORECAST AREA WITH ANY REMAINING SHOWERS EXPECTED TO BE COMPLETELY OUT OF THE AREA BY MID MORNING. THE UPPER LEVEL LOW OVER SASKATCHEWAN WILL LIFT SLOWLY NORTHEAST THROUGH TONIGHT AND BECOME AN OPEN WAVE OVER SOUTHERN MANITOBA AND WESTERN ONTARIO ALLOWING THE FLOW OVER THE UPPER MIDWEST TO BECOME ZONAL. ONE SHORT WAVE TROUGH ROUNDING THE REMAINS OF THIS UPPER LEVEL LOW IS EXPECTED TO MOVE ACROSS NORTHERN MINNESOTA TONIGHT WITH ANOTHER WEAKER WAVE COMING OUT OF THE ROCKIES AND ACROSS NEBRASKA AND SOUTHERN IOWA. NOT A LOT OF PV ADVECTION WITH EITHER OF THESE WAVES...BUT ENOUGH WARM AIR ADVECTION SHOULD OCCUR TO PRODUCE 4 TO 6 UBAR/S OF UP GLIDE ON THE 305K ISENTROPIC SURFACE. THE MODELS ARE SPLIT ON HOW MUCH AND WHERE THE MOISTURE TRANSPORT WILL BE WITH THESE WAVES. THE 20.00Z NAM SUGGESTS WEAK TRANSPORT SHOULD OCCUR AHEAD OF THE NORTHERN WAVE INTO NORTHERN WISCONSIN AND MINNESOTA WHILE THE 20.00Z GFS AND ECMWF HAVE THE MOISTURE TRANSPORT AHEAD OF THE SOUTHERN WAVE INTO NEBRASKA WHERE THEY DEVELOP A CONVECTIVE COMPLEX. THE GFS THEN KEEPS THIS COMPLEX GENERALLY SOUTH OF THE AREA WHILE THE ECMWF BRINGS INTO THE THE AREA. THE 20.03Z SREF PROBABILITIES TEND TO FAVOR THE GFS SOLUTION WITH THE CONVECTIVE COMPLEX BUT ALSO HAVE SOME LOW PROBABILITIES ACROSS THE NORTH SIMILAR TO THE NAM. WITH SUCH WEAK FORCING SIGNALS AND DIFFERING MODEL SOLUTIONS...WILL JUST HAVE SOME LOW RAIN CHANCES ACROSS MOST THE AREA FOR THE OVERNIGHT HOURS. THE ZONAL FLOW CONTINUES INTO SATURDAY WITH ALL THE MODELS SHOWING ANOTHER WEAK WAVE COMING ACROSS THE NORTHERN ROCKIES INTO THE UPPER MIDWEST. THE GFS IS THE FARTHEST NORTH BRINGING THIS ACROSS MINNESOTA INTO IOWA WHILE THE NAM AND ECMWF TAKE IT ACROSS IOWA. THIS RESULTS IN BIG DIFFERENCES IN HOW MUCH AND WHERE THE RAIN COULD FALL. THE NAM AND ECMWF KEEP THE MAJORITY OF THE RAIN TO THE SOUTH OF THE AREA WHILE THE GFS WOULD INDICATE ALL OF THE FORECAST AREA WOULD HAVE A CHANCE FOR GETTING WET. AGAIN...THE SREF PROBABILITIES FAVOR THE NAM AND ECMWF SOLUTIONS SO PLAN TO SHOW 20 TO 30 PERCENT CHANCES THROUGH THE DAY WITH THESE HIGHEST ACROSS THE SOUTH. THE RAIN THAT DEVELOPS SATURDAY SHOULD CONTINUE ACROSS THE SOUTH INTO SATURDAY EVENING BEFORE STARTING TO MOVE OFF TO THE EAST SATURDAY NIGHT. A STRONGER SHORT WAVE TROUGH IS EXPECTED TO MOVE OUT OF THE ROCKIES AND START TO APPROACH THE AREA SUNDAY. THE PV ADVECTION IN THE 500-300 MB LAYER WILL STAY TO THE WEST OF THE AREA. THE ISENTROPIC UP GLIDE AHEAD OF THIS WAVE SHOULD MOVE INTO THE WESTERN SECTIONS OF IOWA AND MINNESOTA BY LATE IN THE DAY SUNDAY. IF THE MODELS REMAIN CONSISTENT WITH THESE SIGNALS...THE BEST RAIN CHANCES SHOULD BE CONFINED TO THE WESTERN SECTIONS OF THE FORECAST AREA AND THE EASTERN SECTIONS COULD BE DRY...BUT WITH THE GFS BEING QUICKER TO MOVE THIS SYSTEM IN...WILL SHOW A 30 TO 40 PERCENT CHANCE FROM EAST TO WEST. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 AM CDT FRI JUN 20 2014 THE MODEL DIFFERENCE CONTINUE INTO EARLY NEXT WEEK AS WELL. GENERAL CONSENSUS THAT THE SHORT WAVE TROUGH THAT COMES OUT SUNDAY WILL WEAKEN AS IT MOVES TOWARD MINNESOTA IN FAVOR OF ANOTHER WAVE COMING ACROSS NEBRASKA OR KANSAS. THE ECMWF THEN TAKES THIS WAVE NORTHEAST AND INTO THE GREAT LAKES REGION THROUGH MONDAY WHILE THE GFS AMPLIFIES THIS FORMING AN UPPER LEVEL LOW OVER THE UPPER MIDWEST MONDAY NIGHT WITH THE 20.00Z GEM DOING SOMETHING VERY SIMILAR. BOTH THE ECMWF AND GFS THEN SHOW WEAK RIDGING BUILDING OVER THE UPPER MIDWEST BY THE END OF PERIOD WITH THE ECMWF QUICKER TO DO THIS THAN THE GFS. BECAUSE OF THE DIFFERENCES BETWEEN THE MODELS...WILL HAVE SOME RAIN CHANCES THROUGH THE ENTIRE PERIOD WITH THE HIGHEST CHANCES MONDAY INTO MONDAY NIGHT WHEN THE FORCING FROM THE WAVE SHOULD BE THE STRONGEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 656 AM CDT FRI JUN 20 2014 AREAS OF FOG AND STRATUS WILL PRODUCE LIFR CONDITIONS AT KRST THROUGH 13Z. MVFR CONDITIONS ARE EXPECTED AT KLSE THROUGH 13Z. HIGH PRESSURE WILL THEN BUILD INTO THE REGION TODAY WITH VFR CONDITIONS EXPECTED. LOOKING AT THE FORECAST SOUNDINGS...THINKING SCATTERED TO BROKEN CUMULUS WILL DEVELOP LATE THIS MORNING BUT THEN SHOULD GRADUALLY FLATTEN AND DISSIPATE DURING THE AFTERNOON HOURS AS DRIER AIR MOVES IN. A WEAK SYSTEM THEN APPROACHES FROM THE PLAINS TONIGHT WITH INCREASING CLOUDS EXPECTED. && .HYDROLOGY... ISSUED AT 342 AM CDT FRI JUN 20 2014 WITH ALL THE RECENT RAINS...NUMEROUS RIVERS AND STREAMS HAVE FLOODING ALONG THEM RESULTING IN AREAL AND RIVER FLOOD WARNINGS. WITH A DRY DAY TODAY...SOME OF THE WATER MAY RECEDE ENOUGH TO ALLOW THE AREAL FLOOD WARNINGS TO BE DISCONTINUED OR MADE SMALLER IN SIZE. HOWEVER...MANY OF THE RIVERS WILL REMAIN ABOVE FLOOD STAGE INTO THE WEEKEND. WHILE ADDITIONAL RAINFALL IS IN THE FORECAST THROUGH THE WEEKEND...EXPECTED AMOUNTS AT THIS TIME SHOULD NOT BE ENOUGH TO AGGRAVATE EXISTING FLOODING PROBLEMS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...WETENKAMP HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1118 AM MDT FRI JUN 20 2014 .UPDATE... ISSUED AT 1115 AM MDT FRI JUN 20 2014 FINE TUNED POP GRIDS OVER FAR SE PLAINS FOR THIS AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM MDT FRI JUN 20 2014 CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING WEAK WESTERLY FLOW ALOFT ACROSS THE REGION AS A MINOR DISTURBANCE (BEST SEEN IN PV FIELDS) EMBEDDED WITHIN THE FLOW IS TRANSLATING ACROSS THE STATE AT THIS TIME. THIS DISTURBANCE...ALONG WITH A LOW LEVEL JET AND AMPLE LOW LEVEL MOISTURE...IS HELPING TO PRODUCE A FEW SHOWERS AND THUNDERSTORMS ACROSS BENT...PROWERS AND KIOWA COUNTIES AT THIS TIME. LATEST HI RES HRRR AND RUC MODELS...WHICH PICKED UP ON THIS DEVELOPMENT LAST EVENING...MOVE THE DISTURBANCE AND STORMS EAST INTO WESTERN KANSAS THROUGH 12Z FRI. TODAY AND TONIGHT...MODELS KEEP WEAK WESTERLY FLOW ALOFT ACROSS THE REGION THROUGH TONIGHT...AND WITH NO EVIDENT DISTURBANCE PROGGED WITHIN THE FLOW...ANY STORMS TODAY LOOK TO BE INITIATED BY SOLAR HEATING. WITH THAT SAID...LATEST MODELS REMAIN CONSISTENT WITH DEVELOPING STORMS ACROSS THE FAR SE PLAINS...GENERALLY EAST OF A KIM TO HASWELL LINE...WHERE CONVECTIVE TEMPS ARE IN THE LOW 90S AND DEW PTS ARE PROGGED IN THE 40S TO LOWER 50S THIS AFTERNOON. THERE IS NOT MUCH SHEAR ACROSS THE STATE WITH THE WEAK FLOW ALOFT...THOUGH WITH CAPES BETWEEN 600-1200 J/KG...COULD SEE A FEW STRONGER STORMS PRODUCING SMALL HAIL AND GUSTY WINDS. FURTHER WEST...DRY AIR ALOFT HELPS TO MIX OUT DEW PTS IN THE 20S AND 30S ACROSS THE HIGHER TERRAIN AND IMMEDIATE ADJACENT PLAINS THROUGH THE AFTERNOON. HOWEVER...WITH STRONG SOLAR HEATING AND MID LEVEL LAPSE RATES AROUND 9C/KM...CANT RULE CU BUILDUPS AND AN ISOLATED HIGH BASED STORM ACROSS THE EASTERN MTS. TEMPS ALOFT WARM A FEW DEGREES AND SHOULD SEE HIGHS SOME 3-6F WARMER THAN YESTERDAY...MOST NOTABLE ACROSS THE EASTERN PLAINS. SHOULD SEE STORMS DIMINISHING AND CLEARING SKIES AFTER SUNSET...THOUGH WITH ANOTHER LOW LEVEL JET PROGGED ACROSS NEAR THE WESTERN KANSAS BORDER...HAVE KEPT SLIGHT POPS ACROSS THE FAR SE PLAINS THROUGH THE OVERNIGHT HOURS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 334 AM MDT FRI JUN 20 2014 .SATURDAY...A WEAK DISTURBANCE WILL PASS MOSTLY NORTH OF THE REGION DURING THE AFTERNOON AND EARLY EVENING. SURFACE LOW PRESSURE WILL DEVELOP OVER SOUTHEAST COLORADO...KEEPING MOST OF THE EASTERLY LOW LEVEL FLOW NORTH OF THE CWA. MODEL SOUNDINGS SHOW SOME MODEST CAPES DURING THE AFTERNOON AND EARLY EVENING OVER THE PLAINS AND EASTERN MOUNTAINS. SUSPECT THE BEST LOW LEVEL MOISTURE WILL STAY NORTH OF THE CWA. HAVE ISOLATED POPS OVER MUCH OF THE REGIONS SATURDAY AFTERNOON AND EVENING. SPC KEEPS SLIGHT RISK OVER NORTHEAST COLORADO ON SATURDAY. CONVECTION MAY TAP INTO BETTER LOW LEVEL MOISTURE NEAR THE KANSAS BORDER AND INCREASED POPS TO SCATTERED CATEGORY SATURDAY EVENING. .SUNDAY...NEXT DISTURBANCE PASSES TO THE NORTH OF THE REGION DURING THE DAY. BEST LOW LEVEL MOISTURE STAYS MOSTLY TO THE NORTH OF THE CWA. INCREASED POPS TO SCATTERED OVER EL PASO AND KIOWA COUNTIES AS COLD FRONT AND ASSOCIATED INCREASE IN LOW LEVEL MOISTURE COULD BE OVER THESE AREAS. AS THE TROUGH PASSES TO THE EAST OF THE REGION...PATTERN CHANGE BEGINS AS THE FLOW ALOFT BECOMES NORTHWESTERLY. SOME MODELS HINT AT A SECONDARY DISTURBANCE PASSING OVER THE REGION SUNDAY EVENING...AFTER THE COLD FRONT HAS PASSED SOUTH OF THE CWA. WITH INCREASED LOW LEVEL MOISTURE... THERE COULD BE A SECOND ROUND OF CONVECTION SUNDAY EVENING...AND INCREASED POPS NEAR THE KANSAS BORDER SUNDAY EVENING. .MONDAY THROUGH WEDNESDAY...NORTHWEST FLOW ALOFT DEVELOPS OVER THE REGION...WITH WEAK EMBEDDED DISTURBANCES. AT THE SURFACE...HIGH PRESSURE OVER THE NORTHERN PLAINS WILL KEEP LOW LEVEL EASTERLY FLOW OVER THE EASTERN HALF OF THE CWA. THIS PATTERN IS PRONE TO PERIODS OF SEVERE CONVECTIVE WEATHER...ESPECIALLY ON THE PLAINS. AMOUNT...INTENSITY AND EXACT LOCATION OF STORMS WILL DEPEND ON SUBTLE FEATURES WHICH ARE DIFFICULT TO FORECAST THIS FAR OUT. MODELS HAVE 30 TO 50 KNOTS OF BULK SHEAR EACH DAY...WHICH IS SUFFICIENT FOR SEVERE WEATHER. LOW LEVEL MOISTURE MAY MOVE AS FAR WEST AS THE EASTERN MOUNTAINS...BUT NOT FURTHER WEST. AS A RESULT...CHANCES FOR SIGNIFICANT RAINFALL OVER THE CONTINENTAL DIVIDE REGION WILL BE LOW. .THURSDAY...UPPER RIDGE STARTS TO MOVE EASTWARD WITH A GENERAL DRYING AND WARMING TREND. GRIDS HAVE SOME ISOLATED POPS OVER THE MOUNTAINS AND PORTIONS OF THE PLAINS...MOSTLY FOR SOME RESIDUAL MOISTURE OVER THE REGION. --PGW-- && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1115 AM MDT FRI JUN 20 2014 VFR CONDITIONS ANTICIPATED NEXT 24H AT ALL 3 TAF SITES...KPUB...KALS AND KCOS. WINDS WILL BE DIURNALLY DRIVEN AND LIGHT. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HODANISH SHORT TERM...MW LONG TERM...PGW AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS MIAMI FL
153 PM EDT FRI JUN 20 2014 .AVIATION... CONVECTION HAS INITIATED ALMOST AS PLANNED, PERHAPS SLIGHTLY EARLIER. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP ACROSS SOUTH FLORIDA THROUGH THE AFTERNOON. SOME OF THEM COULD BE STRONG, WITH HEAVY RAIN REDUCING VSBY AND LOWERING CIGS TO TEMP IFR LEVELS. ALSO, THERE IS A POTENTIAL FOR STRONG DOWNBURSTS AND NUMEROUS OUTFLOW BOUNDARIES. HAVE ADDED TEMPO GROUPS TO ALL ATLANTIC TAF SITES THROUGH 21Z, ALTHOUGH THEY MAY NEED TO BE EXTENDED A FEW HOURS. VFR CONDITIONS OVERNIGHT TONIGHT, AND A GOOD CHANCE OF ANOTHER ROUND OF AFTERNOON CONVECTION TOMORROW AFTERNOON. && .PREV DISCUSSION... /ISSUED 944 AM EDT FRI JUN 20 2014/ UPDATE... WEAK MID/UPPER LEVEL TROUGH OF LOW PRESSURE ALONG WITH A WEAK SURFACE TROUGH REMAIN NEARLY STATIONARY THIS MORNING ALONG THE EASTERN PENINSULA COAST. FORECAST MODELS ALL INDICATE THESE TROUGH BOUNDARIES WILL MOVE LITTLE THROUGH THE DAY. THE 12Z MFL SOUNDING SHOWS A SIMILAR STATE TO THE ATMOSPHERE AS 24 HOURS AGO WITH A VERY MOIST AND UNSTABLE ENVIRONMENT. THE PWAT IS AT 1.9 INCHES WITH THE MOST UNSTABLE CAPE SHOWING OVER 2000 J/KG ALONG WITH A LIGHT WESTERLY STEERING FLOW. THE MID LEVEL LAPSE RATES LIKE YESTERDAY ARE NOT TERRIBLY IMPRESSIVE SO WIDESPREAD SEVERE STORMS ARE NOT EXPECTED. HOWEVER, THE SKY IS STARTING OUT THIS MORNING NEARLY CLOUD FREE SO THERE WILL AGAIN BE ABUNDANT DIURNAL HEATING WHICH WILL SET THE STAGE FOR STRONG UPDRAFTS BY LATE THIS MORNING AS SURFACE TEMPERATURES REACH THE MID AND UPPER 80S. ALL OF THIS SAID, THE FORECAST APPEARS TO BE RIGHT ON TRACK WITH THE HIGHEST CHANCES ALONG THE EAST COAST WITH STRONG THUNDERSTORMS LIKELY AND THERE IS ALWAYS THE OUTSIDE CHANCE OF AN ISOLATED SEVERE STORM WITH THE PRIMARY CONCERN BEING THE STRONG WIND GUSTS. KOB PREV DISCUSSION... /ISSUED 348 AM EDT FRI JUN 20 2014/ DISCUSSION...A WEAK LOW IS CENTERED OFF THE COAST AT CAPE CANAVERAL. THIS IS LEADING TO A LIGHT MEAN WESTERLY STEERING FLOW ACROSS SOUTH FLORIDA. ANOTHER ACTIVE DAY OF TSTORMS IS EXPECTED INTERIOR TO THE EAST COAST METRO AREAS AS A DEVELOPING ATLANTIC SEA BREEZE THIS AFTERNOON BUMPS UP AGAINST THE OPPOSING MEAN WESTERLY WIND FLOW. MOISTURE AND INSTABILITY LOOKS MORE THAN SUFFICIENT TO GET THINGS GOING SO THREW OUT THE LOW GFS MOS POP NUMBERS WHICH LOOK WAY TOO LOW. SIDED WITH NAM MOS AND HRRR WHICH SHOWS ACTIVE CONVECTION FOCUSED EAST COAST METRO. LATEST HRRR REALLY FOCUSES ACTIVITY ACROSS THE FORT LAUDERDALE AND MIAMI METRO AREAS LATE THIS AFTERNOON...WITH LESS ACTIVITY AT THE PALM BEACHES. NAM12 THOUGH FOCUSES CONVECTION FROM THE LAKE TO THE PALM BEACHES. ALTHOUGH I`M CONFIDENT TSTORMS WILL FOCUS EAST COAST METRO, THE EXACT PLACEMENT OF CONVECTION IS UNCERTAIN, SO DID NOT GET FANCY AND PLACED LIKELY POPS UP AND DOWN THE SE FLORIDA COAST THIS AFTERNOON. MAIN CONCERN WILL BE LOCALLY HEAVY RAINFALL AND STRONG WIND GUSTS. LOCALIZED URBAN FLOODING WILL BE POSSIBLE WHERE THE STRONGEST STORMS HIT...ESPECIALLY IF THEY HIT ACROSS AREAS WHICH SAW HEAVY RAINFALL YESTERDAY. WILL HIGHLIGHT THESE POTENTIAL HAZARDS IN THE MORNING HAZARDOUS WEATHER OUTLOOK. A TYPICAL SUMMERTIME PATTERN IS EXPECTED OVER THE UPCOMING WEEKEND AND NEXT WEEK WITH SCATTERED AFTERNOON TSTORMS EXPECTED TO DEVELOP EACH DAY. NO MAJOR SYNOPTIC SCALE FEATURES OF NOTE. THE FOCUS OF STORMS THIS WEEKEND STILL LOOKS TO FAVOR THE EASTERN HALF OF THE AREA...THEN FAVORING INTERIOR AREAS MOST OF NEXT WEEK AS THE RIDGE BUILDS IN AND WE GET INTO MORE OF A SE WIND FLOW PATTERN. GFS AND ECMWF CONTINUE TO DIFFER WITH RESPECT TO MOISTURE NEXT WEEK WITH ECMWF DRYING THINGS OUT MORE SO THAN THE GFS. GFS DOES SEEM TOO STRONG WITH AN INVERTED TROUGH MOVING OUT OF THE CARIB. IT`S HAD A STRONG BIAS ALL SEASON...SO NOT BUYING THIS. HAVE GONE WITH CHANCE POPS MOST LOCALES EACH DAY THROUGH NEXT WEEK...AS SEE NO REASON TO DEVIATE FROM THIS. /GREGORIA MARINE...LIGHT WINDS WILL PREVAIL LEADING TO A CONTINUATION OF LOW SEAS. MAIN HAZARD WILL BE LIGHTNING AND LOCALLY GUSTY WINDS IN AND NEAR TSTORMS. /GREGORIA && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 73 89 76 90 / 40 50 20 20 FORT LAUDERDALE 75 88 78 90 / 40 50 20 20 MIAMI 74 91 76 90 / 40 50 20 20 NAPLES 73 88 74 89 / 20 30 20 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...30/KOB LONG TERM....57/DG AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
245 PM EDT FRI JUN 20 2014 .SYNOPSIS... A SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH SUNDAY AS UPPER LEVEL RIDGING SLIDES WESTWARD. ABOVE NORMAL TEMPERATURES AND THE CHANCE FOR THUNDERSTORMS WILL CONTINUE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THIS AFTERNOON...SHORTWAVE MOVING THROUGH THE MOUNTAINS CURRENTLY PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE FOOTHILLS. THIS SHORTWAVE AND ASSOCIATED ACTIVITY WILL CONTINUE TO MOVE EASTWARD THROUGH THE AFTERNOON AND EVENING...MOVING INTO A MODERATELY UNSTABLE AIRMASS. BEST MOISTURE FIELDS ON SATELLITE APPEAR TO BE ACROSS THE NORTHERN MIDLANDS...WITH ANOTHER ON ACROSS THE EXTREME SOUTHERN PORTIONS OF THE SAVANNAH RIVER REGION. EXPECT TO SEE ADDITIONAL THUNDERSTORM DEVELOPMENT IN BOTH OF THOSE AREAS INTO THE EVENING. AS WITH THE PREVIOUS FEW DAYS...ANY STORMS THAT DEVELOP COULD BECOME SEVERE WITH DAMAGING WIND AND HEAVY RAIN THREATS. LOCAL MODEL ALONG WITH THE LATEST HRRR SHOWING SCATTERED CONVECTION DEVELOPING LATE IN THE AFTERNOON...LASTING WELL INTO THE EVENING. THIS AGREES WITH THE SPCWRF. WILL GO WITH 20 TO 40 PERCENT POPS FOR THE LATE AFTERNOON AND EVENING. TONIGHT...CONVECTION WILL DIMINISH BY MIDNIGHT. HOWEVER...THE AIRMASS WILL REMAIN UNSTABLE WITH PERHAPS A WEAK SHORT WAVE. EVEN THOUGH CANNOT TOTALLY RULE OUT A SHOWER OR THUNDERSTORM OVERNIGHT...ELECTED TO GO WITH MAINLY DRY FORECAST LATE TONIGHT THROUGH EARLY MORNING. KEPT OVERNIGHT LOWS IN THE LOWER 70S...PER PERSISTENCE. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... REMAINS OF A FRONTAL BOUNDARY WILL BE ACROSS THE MID ATLANTIC STATES SATURDAY MORNING WITH A WEAK LOW FORMING OVER NC SATURDAY AFTERNOON. AS THE LOW FORMS THE FRONTAL BOUNDARY WILL DROP FURTHER SOUTH AND INTO THE FORECAST AREA LATE SATURDAY AFTERNOON AND EVENING. THE FRONT WILL STALL JUST SOUTH OF THE FORECAST AREA SATURDAY NIGHT AND REMAIN QUASI-STATIONARY THROUGH SUNDAY NIGHT. MODEL SOUNDINGS SHOW MODERATE INSTABILITY THROUGH THE DAY SATURDAY AND WITH THE FRONT ACTING AS A TRIGGER MECHANISM SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH THE POTENTIAL FOR LARGE HAIL WILL REMAIN LOW...FREEZING AND WET BULB ZERO AROUND 15 KFT AND 12 KFT RESPECTIVELY...WITH DRIER AIR IN THE MID LEVELS THERE WILL BE POTENTIAL FOR STRONG AND DAMAGING WINDS. THE CONVECTIVE POTENTIAL WILL BE A BIT LOWER ON SUNDAY AS THE FRONT WILL BE SOUTH OF THE AREA WITH DRIER AIR SLOWLY MOVING INTO THE MID AND UPPER LEVELS THROUGH THE DAY. TEMPERATURES WILL BE IN THE MIDDLE TO UPPER 90S ON SATURDAY WITH LOWER TO MIDDLE 90S SUNDAY...WITH OVERNIGHT LOWS IN THE UPPER 60S TO LOWER 70S EACH NIGHT. && .LONG TERM /MONDAY THROUGH FRIDAY/... MODELS REMAIN IN GOOD AGREEMENT THROUGH THE WEEKEND WITH THE GFS TAKING A MORE AGGRESSIVE APPROACH IN OPENING THE GULF NEXT WEEK. STALLED FRONTAL BOUNDARY WILL SLOWLY BEGIN RETURNING NORTHWARD ON MONDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE GREAT LAKES REGION. BY TUESDAY EVENING THE FRONT WILL BE ACROSS SOUTHERN NC WITH A WEAK PRESSURE TROUGH LINGERING OVER THE EASTERN US THROUGH THURSDAY. DURING THIS PERIOD THE GFS USHERS MOISTURE NORTHWARD FROM THE GULF WHILE THE ECMWF IS LESS AGGRESSIVE WITH THE MOISTURE. HAVE REMAINED WITH CHANCE POPS THROUGH THE LONG TERM AS THE FRONTAL BOUNDARY MEANDERING ACROSS THE REGION WILL ACT AS A TRIGGER MECHANISM...AND HAVE NOT GONE WITH THE GFS MOISTURE PLUME AS THIS IS A SIGNIFICANT CHANGE FROM THE LAST RUN. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL WITH DAYTIME HIGHS IN THE LOWER 90S AND OVERNIGHT LOWS IN THE UPPER 60S TO LOWER 70S. LONG TERM WITH SOME MINOR DIFFERENCES IN TIMING AND INTENSITY. WEAK LOW PRESSURE WILL SLIDE OFFSHORE OF THE MID ATLANTIC STATES ON SUNDAY WITH THE REMAINS OF THE FRONT PUSHING THROUGH THE FORECAST AREA ON SUNDAY THEN STALLING JUST SOUTH OF THE AREA SUNDAY NIGHT THROUGH EARLY TUESDAY. THE FRONT WILL MEANDER NORTHWARD ON TUESDAY AS THE NEXT LOW PRESSURE SYSTEM CROSSES THE GREAT LAKES. AS THE LOW TRACKS FURTHER EASTWARD WEDNESDAY AND THURSDAY THE COLD FRONT WILL CROSS INTO THE EASTERN US THEN STALL ACROSS THE AREA. THIS SERIES OF FEATURES WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGH THE LONG TERM. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL WITH DAYTIME HIGHS IN THE LOWER TO MIDDLE 90S AND OVERNIGHT LOWS IN THE LOWER 70S. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... GENERALLY VFR CONDITIONS EXPECTED THROUGH THE MAJORITY OF THE PERIOD. SKIES PARTLY CLOUDY WITH BASES AROUND 5KFT THROUGH THE AFTERNOON. WINDS WILL GENERALLY REMAIN LIGHT AND SOMEWHAT VARIABLE. STRONG SURFACE HEATING COMBINED WITH A SHORTWAVE MOVING OUT OF THE CENTRAL APPALACHIANS WILL PROVIDE A FOCUS FOR SOME AFTERNOON CONVECTION. CONVECTION SHOULD BE SCATTERED. DUE TO UNCERTAINTY IN TIMING...DEVELOPMENT...AND EVENTUAL MOVEMENT OF STORMS...WILL NOT INCLUDE IN THE FORECAST AT THIS TIME. UPDATES WILL BE REQUIRED IF CONVECTION IS ABLE TO APPROACH TERMINALS LATE IN THE AFTERNOON. DEBRIS CLOUDS THIS EVENING COULD INHIBIT FOG DEVELOPMENT SATURDAY MORNING. EXTENDED AVIATION OUTLOOK...EARLY MORNING MVFR/IFR FOG POSSIBLE EACH DAY...MAINLY AT FOG PRONE SITES AGS/OGB. SCATTERED DIURNAL THUNDERSTORMS EXPECTED EACH AFTERNOON AND EVENING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
202 PM EDT FRI JUN 20 2014 .SYNOPSIS... A SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH SUNDAY AS UPPER LEVEL RIDGING SLIDES WESTWARD. ABOVE NORMAL TEMPERATURES AND THE CHANCE FOR THUNDERSTORMS WILL CONTINUE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THIS AFTERNOON...SHORTWAVE MOVING THROUGH THE MOUNTAINS CURRENTLY PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE FOOTHILLS. THIS SHORTWAVE AND ASSOCIATED ACTIVITY WILL CONTINUE TO MOVE EASTWARD THROUGH THE AFTERNOON AND EVENING...MOVING INTO A MODERATELY UNSTABLE AIRMASS. BEST MOISTURE FIELDS ON SATELLITE APPEAR TO BE ACROSS THE NORTHERN MIDLANDS...WITH ANOTHER ON ACROSS THE EXTREME SOUTHERN PORTIONS OF THE SAVANNAH RIVER REGION. EXPECT TO SEE ADDITIONAL THUNDERSTORM DEVELOPMENT IN BOTH OF THOSE AREAS INTO THE EVENING. AS WITH THE PREVIOUS FEW DAYS...ANY STORMS THAT DEVELOP COULD BECOME SEVERE WITH DAMAGING WIND AND HEAVY RAIN THREATS. LOCAL MODEL ALONG WITH THE LATEST HRRR SHOWING SCATTERED CONVECTION DEVELOPING LATE IN THE AFTERNOON...LASTING WELL INTO THE EVENING. THIS AGREES WITH THE SPCWRF. WILL GO WITH 20 TO 40 PERCENT POPS FOR THE LATE AFTERNOON AND EVENING. TONIGHT...CONVECTION WILL DIMINISH BY MIDNIGHT. HOWEVER...THE AIRMASS WILL REMAIN UNSTABLE WITH PERHAPS A WEAK SHORT WAVE. EVEN THOUGH CANNOT TOTALLY RULE OUT A SHOWER OR THUNDERSTORM OVERNIGHT...ELECTED TO GO WITH MAINLY DRY FORECAST LATE TONIGHT THROUGH EARLY MORNING. KEPT OVERNIGHT LOWS IN THE LOWER 70S...PER PERSISTENCE. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... A WEAK LOW WILL FORM IN THE MID ATLANTIC AREA ON SATURDAY...ALONG THE REMAINS OF THE FRONT AND PUSH SOUTHWARD INTO THE FORECAST AREA SATURDAY NIGHT. CYCLONIC FLOW WILL CONTINUE ALOFT...ALLOWING SHORT WAVE TO MOVE ACROSS THE COAST STATES. WITH MAX TEMPERATURES CONTINUING IN THE MID TO UPPER 90S...HIGH INSTABILITY AND PWAT VALUES RISING TO 1.8 TO 1.9 INCHES THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE. LARGE HAIL THREAT WILL BE LOW AS FREEZING AND WET BULB ZERO LEVELS WILL BE ABOVE 14 KFT AND 12 KFT RESPECTIVELY. OVERNIGHT LOWS WILL BE IN THE LOWER 70S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... MODELS ARE IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME MINOR DIFFERENCES IN TIMING AND INTENSITY. WEAK LOW PRESSURE WILL SLIDE OFFSHORE OF THE MID ATLANTIC STATES ON SUNDAY WITH THE REMAINS OF THE FRONT PUSHING THROUGH THE FORECAST AREA ON SUNDAY THEN STALLING JUST SOUTH OF THE AREA SUNDAY NIGHT THROUGH EARLY TUESDAY. THE FRONT WILL MEANDER NORTHWARD ON TUESDAY AS THE NEXT LOW PRESSURE SYSTEM CROSSES THE GREAT LAKES. AS THE LOW TRACKS FURTHER EASTWARD WEDNESDAY AND THURSDAY THE COLD FRONT WILL CROSS INTO THE EASTERN US THEN STALL ACROSS THE AREA. THIS SERIES OF FEATURES WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGH THE LONG TERM. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL WITH DAYTIME HIGHS IN THE LOWER TO MIDDLE 90S AND OVERNIGHT LOWS IN THE LOWER 70S. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... GENERALLY VFR CONDITIONS EXPECTED THROUGH THE MAJORITY OF THE PERIOD. SKIES PARTLY CLOUDY WITH BASES AROUND 5KFT THROUGH THE AFTERNOON. WINDS WILL GENERALLY REMAIN LIGHT AND SOMEWHAT VARIABLE. STRONG SURFACE HEATING COMBINED WITH A SHORTWAVE MOVING OUT OF THE CENTRAL APPALACHIANS WILL PROVIDE A FOCUS FOR SOME AFTERNOON CONVECTION. CONVECTION SHOULD BE SCATTERED. DUE TO UNCERTAINTY IN TIMING...DEVELOPMENT...AND EVENTUAL MOVEMENT OF STORMS...WILL NOT INCLUDE IN THE FORECAST AT THIS TIME. UPDATES WILL BE REQUIRED IF CONVECTION IS ABLE TO APPROACH TERMINALS LATE IN THE AFTERNOON. DEBRIS CLOUDS THIS EVENING COULD INHIBIT FOG DEVELOPMENT SATURDAY MORNING. EXTENDED AVIATION OUTLOOK...EARLY MORNING MVFR/IFR FOG POSSIBLE EACH DAY...MAINLY AT FOG PRONE SITES AGS/OGB. SCATTERED DIURNAL THUNDERSTORMS EXPECTED EACH AFTERNOON AND EVENING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
148 PM EDT FRI JUN 20 2014 .UPDATE... ISSUED AT 1039 AM EDT FRI JUN 20 2014 ISOLATED SHOWERS AND A FEW RUMBLES OF THUNDER CONTINUE ACROSS EASTERN KY. LIKE PREVIOUS FORECAST...EXPECT THINGS TO START FIRING UP TO MORE SCATTERED COVERAGE DURING THE AFTERNOON HOURS AS WE START TO HEAT UP. UPDATED THE SKY GRIDS FOR THE NEXT FEW HOURS TO BETTER MATCH THE CURRENT CONDITIONS...WITH COVERAGE EXPECTED TO INCREASE THROUGHOUT THE AFTERNOON. LEFT POPS AS IS...WITH ISOLATED TO SCATTERED CHANCES OVER THE NEXT FEW HOURS. ALSO INCLUDED THE LATEST OBSERVATIONAL DATA IN THE CURRENT FORECAST TO MAKE SURE THE TEMPS...DEW POINTS...AND WINDS FORECASTS ARE REFLECTING THE CURRENT DATA. UPDATE ISSUED AT 750 AM EDT FRI JUN 20 2014 HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT RADAR AND SATELLITE TRENDS. SOME SHOWERS AND THUNDERSTORMS HAVE ALREADY DEVELOPED THIS MORNING...THOUGH THEY SHOULD INCREASE IN COVERAGE AND INTENSITY BY EARLY IN THE AFTERNOON. THE THREAT FOR SHOWERS AND THUNDERSTORMS SHOULD LINGER THROUGH THE ENTIRE DAY. OUTSIDE OF SHOWERS AND THUNDERSTORMS WARM AND HUMID WEATHER IS ANTICIPATED. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 359 AM EDT FRI JUN 20 2014 THE REGION REMAINS IN THE WARM SECTOR SOUTH OF A FRONTAL ZONE EXTENDING FROM THE CAROLINAS NORTHWEST TOWARD LOW PRESSURE OVER THE NORTHERN PLAINS AND UPPER MS VALLEY REGION. THE OVERALL FLOW ACROSS THE CONUS ATTM IS RATHER ZONAL IN NATURE WITH MID LEVEL RIDGING CENTERED OVER THE LOWER MS RIVER VALLEY...WITH LOW AMPLITUDE RIDGING NORTH TOWARD THE OH RIVER VALLEY. WELL TO THE NORTHEAST OF EAST KY... A MID LEVEL LOW AND ASSOCIATED SFC LOW THAT HAS HELPED TO PUSH THE BOUNDARY SOUTH ALONG THE EASTERN SEABOARD TO THE CAROLINAS REMAINS PLACE WHILE A CLOSED LOW IS WORKING ACROSS THE NORTHERN ROCKIES TOWARD THE NORTHERN PLAINS REGION ALONG US/CANADIAN BORDER. MEANWHILE...A SHORTWAVE TROUGH IS SLOWLY WORKING FROM THE PLAINS INTO THE MID MS AND LOWER OH VALLEY REGION. THE SHORTWAVE TROUGH WILL WORK INTO THE LOWER OH VALLEY REGION OVER THE NEXT FEW HOURS AND IS POISED TO MOVE ACROSS EASTERN KY AND INTO THE APPALACHIAN REGION LATE THIS AFTERNOON AND INTO THIS EVENING. AS THIS SHORTWAVE APPROACHES A SFC WAVE SHOULD DEVELOP AND WORK EAST SOUTHEAST ALONG THIS NEARLY STATIONARY BOUNDARY AND CROSS THE APPALACHIANS TONIGHT. THIS LOW SHOULD REACH THE EASTERN SEABOARD ON SATURDAY WITH THE TAILING COLD FRONT GRADUALLY SAGGING INTO EASTERN KY AND CROSSING MUCH OF THE AREA BY THE END OF THE PERIOD. THROUGH SHORTLY AFTER DAWN...PATCHY RIVER VALLEY FOG SHOULD REMAIN IN PLACE...WITH THIS FOG GRADUALLY BEGINNING TO LIFT AND POSSIBLY AFFECTING A FEW RIDGETOP LOCATIONS NEAR LOCATIONS THAT EXPERIENCED THE HEAVIER RAINFALL ON THU AND THU EVENING. THIS FOG SHOULD LIFT AND DISSIPATE SHORTLY AFTER DAWN. ALSO...THE NEAR TERM MODELS SUCH AS RECENT HRRR RUNS AND RECENT RAP RUNS HAVE SOME CONVECTION DEVELOPING NEAR SUNRISE BETWEEN JKL AND LOZ OR FROM ESTILL COUNTY SOUTH TO BELL COUNTY AND THEN MOVING EAST TO NEAR THE KY 15 CORRIDOR FROM JKL SOUTH TO THE VA BORDER AND THEN INTO FAR SOUTHEAST KY BEFORE NOON. THE 6Z NAM ALSO HAS SOME CONVECTION...BUT IS FURTHER EAST NEAR TO THE VA BORDER ACROSS THE BIG SANDY REGION. HOWEVER...EVEN IF THERE IS SOME MORNING CONVECTION...JUST A FEW HOURS OF THE STRONG JUNE SUNSHINE SHOULD BRING MID TO UPPER 80S SFC TEMPS WITH SFC DEWPOINTS IN THE MID 60S TO NEAR 70 DEGREE RANGE TO YIELD CAPE OF 2000 J/KG OR MORE BY MID TO LATE AFTERNOON. LAPSE RATES IN THE MID LEVELS WILL NOT BE PARTICULARLY STRONG AND RATHER WEAK SHEAR SHOULD LIMIT STORM ORGANIZATION. HOWEVER... A FEW CELLS...POSSIBLY SECOND AND THIRD GENERATION CELLS THAT DEVELOP NEAR OUTFLOW INTERSECTIONS COULD BECOME STRONG TO LOCALLY SEVERE AND PRODUCE STRONG TO LOCALLY DAMAGING WIND GUSTS. SPC HAS PLACED THE REGION IN A SEE TEXT AREA WITH 5 PERCENT PROBABILITIES FOR SEVERE THUNDERSTORM CRITERIA WINDS AND THIS APPEARS REASONABLE. THE MAIN THREAT FROM STORMS LATER TODAY AND TONIGHT MAY END UP BEING LOCALLY HEAVY RAINFALL RATES AS PW IS EXPECTED TO BE AT OR ABOVE THE 75TH PERCENTILE. THE PRESENCE OF THE SAGGING BOUNDARY AND THE POTENTIAL FOR CONVECTION TO TRAIN IN SOME AREAS AS THE STEERING FLOW MAY BECOME NEARLY PARALLEL TO THE SAGGING BOUNDARY OR OUTFLOWS COULD LEAD TO A LOCALIZED THREAT OF FLOODING. UNCERTAINTY REMAINS IN THE DETAILS AS FAR AS TIMING AND LOCATION. IN GENERAL...IT APPEARS THAT AS THE SHORTWAVE WORKS INTO EASTERN KY AND THE APPALACHIANS...CONVECTION SHOULD BE MOST WIDESPREAD DURING THE LATE AFTERNOON INTO LATE EVENING. THE HWO HAS BEEN ADJUSTED ACCORDINGLY FOR ALL OF THESE THREATS. THE THREAT OF SOME CONVECTION WILL LINGER EVEN INTO THE DAY ON SATURDAY AND WILL PROBABLY FEATURE A DIURNAL UPTICK IN CONVERGE. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 406 AM EDT FRI JUN 20 2014 THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A TYPICAL SUMMER PATTERN IN PLACE. A NEAR ZONAL UPPER LEVEL FLOW CONTINUES BUT WITH THE USUAL MID LEVEL RIDGE IN THE SOUTHEAST NOW SHIFTED TOWARDS THE WESTERN GULF OF MEXICO. BRIEF RIDGING WILL KEEP PRECIP MAINLY DIURNALLY DRIVEN AS THE BULK OF THE SUPPORT EXITS EASTERN KENTUCKY SATURDAY NIGHT...LEAVING ONLY SLIGHT CHANCE PRECIP INTO THE DAY ON SUNDAY WITH THE MAX HEATING. BY MONDAY...A SIGNIFICANT SHORTWAVE MOVES ACROSS THE PLAINS AND INTO THE OH VALLEY. THIS WAVE WILL BE THE FOCUS OF ACTIVE WEATHER THROUGH THE MID PORTION OF THE EXTENDED. THE MENTIONED WAVE PUSHES THROUGH ON MONDAY NIGHT AND TUESDAY PUSHING A SURFACE COLD FRONT THROUGH. THIS FORCING AND THE WAVE MOVING THROUGH WILL PROVIDE THE BEST CHANCE OF PRECIP ON TUESDAY AND INTO TUESDAY NIGHT. THE EURO HINTS AT THE FRONT STALLING AND BECOMING AN EAST WEST STATIONARY BOUNDARY ALONG SOUTHERN KY BY THE WED AND THU TIME FRAME. THIS BECOMES AN POINT OF DEVELOPING CONVECTION THROUGH THE LAST COUPLE DAYS OF THE EXTENDED. THE CHANCES WITH THIS SET UP BECOME DIURNALLY DRIVEN WITH THE HEATING OF THE DAY. THE LACK OF CONTINUITY OF GUIDANCE AND NEED TO STAY CONSISTENT WITH THE NEIGHBORING OFFICES...LEAD TO KEEPING VALUES CLOSER TO THE ALL MODEL BLEND SOLUTION. THE MONDAY THROUGH TUESDAY NIGHT PERIOD REMAINS A PERIOD TO WATCH WITH THE STRONG WAVE MOVING THROUGH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 147 PM EDT FRI JUN 20 2014 SCATTERED TSRA HAVE STARTED TO DEVELOP ACROSS EASTERN KY...POSSIBLY AFFECTING ANY OF THE TAF SITES THROUGH THE AFTERNOON AND EVENING. THESE THUNDERSTORMS ARE MOVING QUICKLY...SO SHOULD NOT LAST VERY LONG. HOWEVER...THEY COULD PRODUCE HEAVY RAIN...SMALL HAIL...FREQUENT LIGHTNING...AND HIGH TO POSSIBLY DAMAGING WINDS. SINCE TSRA WILL BE OFF AND ON...CHOSE TO USE A TEMPO GROUP WITH THE TSRA BEING THE NON PREVAILING WX TYPE. TRIED TO GIVE THE BEST OVERALL GUESS FOR VSBY...BUT EACH CELL WILL LIKELY BEHAVE DIFFERENTLY...WITH THE LEVEL OF RAINFALL INFLUENCING THE VSBY RESTRICTION. EXPECT TSRA TO BE ON A DIMINISHING TREND AT TAF SITES AFTER 4 OR 5Z...THOUGH ABUNDANT MOISTURE AND LIGHT WINDS COULD LEAD TO SOME BR RESTRICTIONS OVERNIGHT. DAYTIME HEATING IN THE MORNING WILL WORK TO BURN OFF ANY BR...BUT WILL ALSO REINTRODUCE THE CHANCES FOR MORE SHOWERS AND THUNDERSTORMS TO AFFECT TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...JP LONG TERM...SHALLENBERGER AVIATION...JMW
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1242 PM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT FRI JUN 20 2014 FIRST CONCERNS IS DENSE FOG ADV ACROSS MPX CWA. SECONDARY CONCERN IS ISOLD/SCT CONVECTION ALONG AN INSTABILITY AXIS MOVING ACROSS MN THIS AFTN. PLENTY OF RAINFALL OVER THE LAST 24 HRS FOR BOUNDARY LAYER TO SATURATE. HOWEVER...BOUNDARY LAYER WINDS INCREASED SLIGHTLY AFT MIDNIGHT ALLOWING FOR MAINLY LOW STRATUS AND PATCHY DENSE FOG ACROSS SC MN...BUT THE MAJORITY OF MPX CWA HAD PATCHY FOG WITH LOCALIZED DENSE FOG WHERE CIGS DROPPED TO 100-200`. BASED ON CURRENT VIS/FOG SATELLITE IMAGERY AND BOUNDARY LAYER WINDS ARND 5-10 KTS ANTICIPATE THAT THE DENSE FOG ADV WILL BE CANCELLED EARLY...PROBABLY BEFORE SUNRISE. WILL MONITOR FOR ANY NEW DEVELOPMENT ACROSS SC/EC MN FOR CIGS/VSBYS DROPPING LOWER...BUT THIS IS NOT EXPECTED TO CAUSE WIDESPREAD DENSE FOG...ONLY PATCHY DENSE FOG. A COUPLE OF ITEMS TO NOTE EARLY THIS MORNING FOR THE POTENTIAL OF CONVECTION THIS AFTN. FIRST...A WEAK SHRTWV ROTATING ARND THE SOUTHERN PART OF THE MAIN UPPER LOW ACROSS SOUTH CENTRAL CANADA WILL LIKELY PROVIDE SOME LIFT LATER THIS AFTN ACROSS MN. RUC DOES SHOW 85/92H WINDS BECOMING MORE SSW/SW THIS AFTN ACROSS NE/SD WHICH WILL PULL RESIDUAL MOISTURE ACROSS KS/CO NE INTO SW MN DURING THE AFTN. MLCAPES AND MLCIN REFLECT THE CHC/S THIS AFTN IN A THIN BAND FROM SW TO CENTRAL MN. DUE TO WEAK SFC CONVERGENCE AND GREATER SHRTWV STRENGTH ACROSS NORTHERN MN...ONLY ISOLD/SCT SHRA/TSRA WILL BE POSSIBLE. 20-30% SEEMS REASONABLE AT THIS TIME. LATER SHIFTS WILL NEED TO MONITOR FOR HIGHER MOISTURE ADVECTING NE ACROSS S MN. THE SAME SW WINDS IN THE FIRST 5K ACROSS SD AND INTO WC MN THIS AFTN MAY CAUSE ENOUGH MIXING TO HAVE TEMPS RISE INTO THE LOWER 90S. BUT BASED ON THE WET SOIL CONDS AND DEW PTS IN THE 50S/60S...AM LEANING TOWARD MID TO UPPER 80S AT THIS TIME. TONIGHT WILL LIKELY SEE THE CONVECTION DECREASING RAPIDLY AFT SUNSET WITH MOST OF THE ACTION SOUTH OF THE MN AS THE LLJ DEVELOPS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 347 AM CDT FRI JUN 20 2014 THERE COULD BE AN ONGOING MCS IN NORTHEAST NE OR NORTHERN IA COME 12Z SATURDAY MORNING WITH THE AFOREMENTIONED INCREASING LLJ...BUT THE 850-300MB WINDS AND THICKNESS PATTERN SUGGEST ANY ORGANIZED /OR UNORGANIZED CONVECTION FOR THAT MATTER/ SHOULD TRACK E-SE WITH TIME AND REMAIN SOUTH OF THE FORECAST AREA THROUGH THE MORNING HOURS. EVEN MOST OF THE CLOUD DEBRIS SHOULD BE CARRIED DOWNSTREAM TO THE EAST. THE NAM/GFS/ECMWF ALL SEEM TO BE DEPICTING A WEAK TROUGH IN WESTERN WI AND LIGHT QPF. THE SOUNDINGS ARE FAIRLY DRY ON SATURDAY AND THERE ISN`T A CLEAR TRIGGER OUTSIDE OF PERHAPS A WEAK MID LEVEL WAVE IN IA. THERE IS MODEST ELEVATED INSTABILITY AND EVEN THE ECMWF DOES HINT AT CONVECTIVE INITIATION...BUT THE SHOWER/THUNDER CHANCES LOOK BETTER SOUTH AND EAST OF THE FORECAST AREA. SUNDAY IS PERHAPS A LITTLE MORE INTERESTING AND SUGGESTS A NEED FOR SLIGHTLY HIGHER POPS AS AN ADVANCING SURFACE BOUNDARY TRIES TO MAKE IT ACROSS MINNESOTA DURING THE DAY WITH A SHORTWAVE APPROACHING FROM THE CENTRAL PLAINS. ALTHOUGH PERHAPS A LITTLE OVERDONE WITH SURFACE DEWPOINTS...BOTH THE NAM-GFS HAVE LARGE MUCAPE VALUES OF 3000-5000 J/KG IN SOUTHERN MINNESOTA. THE SHEAR PROFILE IS WEAK...WHICH WILL SUPPRESS THE THREAT FOR SEVERE WEATHER. THERE IS ALSO UNCERTAINTY AS TO HOW MUCH CONVECTION THERE WILL BE...BUT GIVEN THE LARGE AMOUNT OF INSTABILITY...PULSE STORMS AND SMALL MULTICELL CLUSTERS COULD STILL POSE A MARGINAL SEVERE THREAT IF EVERYTHING PANS OUT. THE BEST CHANCE FOR MORE WIDESPREAD RAIN IN THE AVAILABLE MODEL GUIDANCE IS MONDAY AFTERNOON INTO EARLY TUESDAY MORNING WITH A DEVELOPING SURFACE CYCLONE TRACKING OUT OF THE SOUTHERN PLAINS AND DEEPENING WITH TIME AS IT HEADS TOWARD IA/WI. THERE IS A BIT MORE CONFIDENCE IN PRECIP AT LEAST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA BECAUSE THE GFS/ECMWF SOLUTIONS HAVE SETTLED DOWN OVER THE PAST 3-4 MODEL CYCLES. PREVIOUS RUNS THIS WEEK WERE ALL OVER THE PLACE WITH PLACEMENT AND TIMING. OTHERWISE WE`LL REMAIN IN A FAIRLY INNOCUOUS /AT LEAST COMPARED TO THE HEAVY RAIN PATTERN WE`VE BEEN IN RECENTLY/ WESTERLY FLOW THROUGH NEXT WEEK WITH NO BIG SYSTEMS...SEVERE WEATHER OUTBREAKS...BIG TEMPERATURES SWINGS...ETC. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1242 PM CDT FRI JUN 20 2014 CEILINGS CONTINUE TO LIFT/DISSIPATE ALONG AND EAST OF THE MN/WI BORDER EARLY THIS AFTERNOON. THE CU RULE IS FORECAST TO BECOME RATHER POSITIVE AS THE AFTERNOON PROGRESSES...SO ONLY TEMPORARY MVFR CIGS AT KRNH AND KEAU EARLY. A THREAT FOR STRONG TO SEVERE STORMS REMAINS ACROSS CENTRAL MN AND ADJOINING AREAS OF WEST CENTRAL WI LATE TODAY/EARLY TONIGHT. SHORT TERM SOLUTIONS ARE IN AGREEMENT ON KEEPING THIS ACTIVITY TO THE NORTH OF KAXN...KSTC AND KRNH. SURFACE WINDS WILL BE ON THE INCREASE FROM THE SSE THIS AFTERNOON AS THE PRESSURE GRADIENT TIGHTENS. A CONCERN OVERNIGHT IS DENSE FOG. BUFKIT NAM PROFILE DATA SHOWS THE BEST THREAT AREA TO BE ACROSS FAR EASTERN MN AND WEST CENTRAL WI WHERE WINDS ARE LIGHTEST...SATURATION THE GREATEST ALONG WITH A FAVORABLE LOW LEVEL HYDROLAPSE. INDICATED 1/2SM FG FOR KEAU BEFORE DAYBREAK WITH 2SM BR FOR KRNH AND 3SM BR FOR KSTC. ONE THING THAT COULD DERAIL THE DENSE FOG OVERNIGHT IS THE CI/CS BLOW OFF FROM STORMS DEVELOPING/MOVING ACROSS NE/IA. KMSP..A VFR AFTN WITH WINDS INCREASING FROM THE SSE. STORMS EXPECTED TO STAY WELL NORTH OF THE AIRFIELD THIS EVENING. KEPT THE FOG THREAT TO A MINIMUM FOR SATURDAY MORNING WITH MID/HIGH LEVEL CLOUDINESS POSSIBLE ACROSS THE AREA WHICH WILL AID IN DIMINISHING LOW LEVEL SATURATION. /OUTLOOK FOR KMSP/ SUN...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS SE 10 KTS. MON...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS NW 10 KTS. TUE...VFR. WINDS NW 10-15 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JLT LONG TERM...CLF AVIATION...RAH
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
242 PM CDT FRI JUN 20 2014 .SHORT TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 240 PM CDT FRI JUN 20 2014 THUNDERSTORM COVERAGE/CHANCES REMAIN PRIMARY CONCERN IN SHORT TERM AS ACTIVE JUNE PATTERN GENERALLY PERSISTS INTO MONDAY. AFTERNOON SATELLITE IMAGERY SHOWED A CLOSED UPPER LOW PIVOTING ACROSS SRN SASK CANADA WITH A LOBE EXTENDING SWD ALONG ND/MN BORDER AT 19Z. THIS LOBE HAS SENT A WEAK BOUNDARY INTO NRN NEBR...PRIMARILY A DEWPOINT FRONT WITH AROUND 70 DEG SFC DWPTS FEEDING INTO IT ACROSS NWRN ZONES WITH UPPER 40S JUST TO OUR NW. ALTHOUGH EARLIER CONVECTION DISPTD...CONTINUED UPSCALE DEVELOPMENT EXPECTED THROUGH EARLY EVENING AS SPC MESO PAGE SUGGESTED LITTLE/NO CONVECTIVE INHIBITION WITH 3.5K+ J/KG MLCAPE SOUTH OF BOUNDARY. WITH 0-6KM BULK SHEAR GENERALLY ON LIGHTER SIDE...AROUND OR BELOW 30KTS...AFTER INITIAL SVR DEVELOPMENT WITH HEATING DRIVEN INSTABILITY RELEASE...FEEL BULK OF ACTIVITY COULD TRANSITION MORE TOWARD A HEAVY RAIN ISSUE AS H85 JET REMAINS FOCUSED INTO NERN ZONES. UPPED POPS AND QPF ALTHOUGH WENT CLOSER TO ECMWF QPF AS H85 JET ONLY MODEST AND MOISTURE TRANSPORT LATER TONIGHT APPEARED TO FOCUS SE OF WHERE BULK OF PRECIP MAY EXIST. MODEL INDICATIONS ARE THAT PRECIP COULD LINGER SATURDAY MORNING ACROSS MAINLY WRN IA ZONES...AND POSSIBLY EXTREME NERN NEBR...BUT BULK OF AREA MUCH OF THE DAY COULD BE DRY. CONTINUED THIS TREND FROM PRIOR FORECAST BUT RAISED MAX TEMPS...ESPECIALLY SW...AS AREA SHOULD RECOVER EARLIEST FROM ANY MORNING CLOUDS/ISOLD TSTMS. LATER IN THE DAY THE FA REMAINS ON SOUTH SIDE OF FASTER UPPER FLOW WITH FILLING SRN CANADA TROUGH PROVIDES AREA WITH SOME UPPER DIVERGENCE. HOWEVER...LESS SFC CONVERGENCE WAS NOTED ALONG A WEAKENED SFC BOUNDARY AND THUS DEVELOPMENT COULD WAIT UNTIL ANOTHER LOBE ROTATING AROUND UPPER LOW SENDS A STRONGER BOUNDARY INTO NWRN ZONES LATER SAT NIGHT. THIS BOUNDARY THEN WEAKENS OR SLOWS AS IT PUSHES INTO FORECAST SUNDAY...PROBABLY ENOUGH TO WARRANT INCREASING HIGHS SERN ZONES. MODELS REMAIN FAIRLY CONSISTENT IN SLOWLY SAGGING THE BOUNDARY ACROSS ZONES SUNDAY/SUNDAY NIGHT AS A STRONGER PIECE OF ENERGY EJECTS FROM ROCKIES...THUS MODESTLY HIGH POPS WERE MAINTAINED. THESE HIGH POPS WERE ALSO MAINTAINED FOR MONDAY PERIOD SERN ZONES DUE TO UNCERTAINTIES IN HOW FAST THIS ENERGY SHIFTS EAST OF THE FA. COULD SEE SOME REDUCTIONS IN LATER FORECASTS IF FASTER NAM WOULD VERIFY. COOL ADVECTION/CLOUDS/LINGERING PRECIP ALL INDICATE COOLER TEMPS SHOULD PREVAIL ON MONDAY. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 240 PM CDT FRI JUN 20 2014 12Z GFS/ECMWF SUPPORT A DRY FORECAST MONDAY NGT/TUESDAY MUCH OF THE FA AS NW FLOW SPREADS OVER THE AREA BEHIND DEPARTING TROUGH. HOWEVER...TRAILING ENERGY WILL HOLD UP BOUNDARY LATE TUE NIGHT AND THEN BUILDING UPPER RIDGE WILL LIKELY LIFT IT BACK NORTH. ALTHOUGH THIS BUILDING RIDGE COULD EVENTUALLY SHUT DOWN OR GREATLY REDUCE PRECIP THREAT A PERIOD OR TWO...RETURNING BOUNDARY/MOISTURE/INSTABILITY WILL BRING A RENEWED THREAT IN TUE NGT THROUGH WED NIGHT PERIODS AND NEXT TROUGH APPROACHING LATE NEXT WEEK WITH LOBES POTENTIALLY EJECTING OUT PROVIDING ADDITIONAL SUPPORT. THUS SMALL POPS WILL BLANKET EXTENDED AND WILL ALLOW LATER FORECASTS TO BETTER FINE- TUNE PARTICULAR PERIODS AS DAYS GET CLOSER. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1244 PM CDT FRI JUN 20 2014 TIMING OF CONVECTION THIS AFTERNOON AND EVENING WILL BE THE MAIN UNCERTAINTY IN THE FORECAST. EARLIER CONVECTION OVER CENTRAL NEBRASKA HAS RAPIDLY COLLAPSED SINCE 17Z AND UNSURE OF ANY SPECIFIC FORCING TO KEY ON THROUGH 00Z. HRRR INDICATES ADDITIONAL DEVELOPMENT AFTER 20Z SO HAVE FOLLOWED THIS IDEA IN LATEST FORECAST. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...CHERMOK LONG TERM...CHERMOK AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
115 PM CDT FRI JUN 20 2014 .UPDATE... ISSUED AT 114 PM CDT FRI JUN 20 2014 SHOWERS AND THUNDERSTORMS HAVE DIMINISHED TO A FEW SPRINKLES...HOWEVER THIS IS EXPECTED TO ONLY BE A SHORT TERM. STALL BOUNDARY CONTINUED TO RESIDE ACROSS THE STATE. EARLY THIS AFTERNOON EXPECT THE SUN TO COME ON WITH TEMPS TO RISE INTO THE MID AND UPPER 80S. THIS WILL CAUSE THE CAP TO WEAKEN AND SCT THUNDERSTORMS ARE EXPECTED TO DEVELOP. DEVELOPMENT IS EXPECT EAST OF A VTN TO OGA LINE. INSTABILITY INCREASES WITH CAPE VALUES OF A 2K TO 3K J/KG...AND A WEAK WAVE CROSSING THE ROCKIES THIS AFTERNOON WILL PROVIDE THE NEEDED KICK START TO GET THINGS GOING AGAIN. EXPECT STORMS TO REDEVELOP AROUND 4 PM CDT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT FRI JUN 20 2014 THE NAM AND RAP SHOW AN AREA OF MIDLEVEL CLOUDS ACROSS ERN COLO THIS MORNING BECOMING CONVECTIVELY ACTIVE 09Z-12Z THIS MORNING. THE DISTURBANCE SHOULD MOVE EAST THRU SRN NEB THIS AM PRODUCING A CLUSTER OF ELEVATED TSTMS. THE RAP INDICATES 750MB CAPE OF AROUND 1000 J/KG SUGGESTING THE POTENTIAL FOR SOME HAIL. THIS ACTIVITY DISSIPATES LATE THIS MORNING TO BE FOLLOWED BY A SECOND AREA OF TSTM DEVELOPMENT FROM ROUGHLY KIML NORTHEAST THROUGH KONL THIS AFTN WITH THE BETTER RAIN CHANCES FROM HAYES CENTER NORTHEAST THROUGH KONL. BUFKIT SUGGESTS A WEAK MULTICELL ENVIRONMENT GIVEN THE WEAK SHEAR AROUND 25 KT. MLCAPE THOUGH AROUND 3000 J/KG IN THE RAP MODEL SUGGESTS SOME STRONG UPDRAFTS DEVELOPING THIS AFTN NEAR OR SOUTH OF KOGA AND KLBF. SO SEVERE WEATHER CHANCES CONTINUE ALTHOUGH THE POTENTIAL FOR LONGER LIVED STORMS WOULD APPEAR LOW. STORMS WILL LIKELY FIRE FROM SOUTHWEST NEB TO NCNTL NEB THIS AFTERNOON AND THIS EVENING AND COALESCE INTO CLUSTERS WHICH MOVE OFF EAST OF THE FCST AREA AROUND 06Z. POPS ARE LIMITED TO 40 PERCENT GIVEN THE WEAKNESS IN THE WINDS ALOFT AND LOW QPF GENERATED BY THE MODELS. HIGHS TODAY RISE INTO THE 80S AND LOWS TONIGHT FALL INTO THE 50S TO LOWER 60S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 325 AM CDT FRI JUN 20 2014 MOIST...WARM AND UNSTABLE CONDITIONS WILL CONTINUE ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA SATURDAY. MODELS ALL AGREE THAT A WARM FRONT WILL BE LOCATED IN AN EAST TO WEST FASHION...BUT DISAGREE ON THE LOCATION. REGARDLESS...IT APPEARS THAT SCATTERED TSTMS WILL INITIATE ACROSS THE HIGH PLAINS IN MOIST UPSLOPE REGIME. THESE WILL LIKELY BEGIN AS SUPERCELLS WITH BULK SHEAR NEAR 40 KTS. BUFKIT DATA FROM VARIOUS LOCATIONS ACROSS THE PLAINS SUGGESTS RIGHT TURNING SUPERCELLS THE DOMINATE STORM MODE AT FIRST...THEN CONGEAL INTO ONE OR MORE CLUSTERS SATURDAY NIGHT AS SOUTHERLY LOW LEVEL JET INCREASES. THE WARM FRONT LOCATION WILL HAVE TO BE MONITORED...AS WINDS WILL BE BACKED MORE TO THE EAST ON THE NORTH SIDE OF THE BOUNDARY...WHICH WILL ENHANCE LOW LEVEL SHEAR AND POSSIBLE TORNADO DEVELOPMENT. SUNDAY A SHORTWAVE DISTURBANCE WILL TRACK ACROSS THE NORTHERN ROCKIES AND TOWARD THE NORTHERN PLAINS. A SURFACE LOW WILL DEEPEN ACROSS EASTERN COLORADO IN RESPONSE...WITH MOIST EAST TO NORTHEAST WINDS ACROSS MOST OF WESTERN AND NORTH CENTRAL NEBRASKA TO THE NORTH OF THE LOW. STORM DEVELOPMENT WILL BE AIDED BY THE SHORTWAVE DISTURBANCE ACROSS THE PANHANDLE SUNDAY AFTERNOON...WITH STORMS LIKELY MERGING INTO AN MCS AS THEY TRACK EAST SOUTHEAST ACROSS NEBRASKA SUNDAY EVENING. LOCALLY HEAVY RAIN COULD MATERIALIZE AND POTENTIAL WILL HAVE TO BE MONITORED. MONDAY INTO TUESDAY...SOMEWHAT COOLER AND DRIER BEHIND THE SHORTWAVE DISTURBANCE. BY MIDWEEK...RICH GULF MOISTURE RETURNS. MODELS INDICATING DEW POINTS IN THE UPPER 60S TO NEAR 70 FOR MUCH OF THE FORECAST AREA BY WEEKS END. THATS WHEN TSTM CHANCES MAY INCREASE ONCE AGAIN...AS UPPER LEVEL TROUGHING DEVELOPS INTO THE PACIFIC NORTHWEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 114 PM CDT FRI JUN 20 2014 SHOWERS WILL EXIT THE KLBF AREA OVER THE NEXT HOUR...WITH THE SUN COMING OUT. AFTER A BRIEF BREAK IN ACTIVITY...STORMS ARE EXPECTED TO REDEVELOP LATER THIS AFTERNOON INTO THE EVENING HOURS ACROSS SOUTHWEST INTO N CENTRAL NEB. ACTIVITY HAS THE CHANCE TO IMPACT KLBF...ALTHOUGH LESS CONFIDENCE IN ACTIVITY TO IMPACT KVTN. DID INCLUDE A SOME TS IN THE KLBF TAF...HOWEVER WATCH FOR AMENDMENTS AS TIMING MAY BE OFF OR NEEDED TO BE EXTEND. ACTIVITY WILL LIFT TO THE NORTHEAST OVERNIGHT WITH SKIES CLEARING FROM THE WEST. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MASEK SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1253 PM CDT FRI JUN 20 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 327 AM CDT FRI JUN 20 2014 EARLY MORNING WATER VAPOR IMAGERY INDICATES THAT THE PERSISTENT UPPER LEVEL LOW IS SLOWLY MOVING INTO SRN SASK AS A STRONG SHORTWAVE TROUGH ROTATES THROUGH THE BASE OF THE TROUGH OVER NORTHERN MN. UPSTREAM OVER THE ROCKIES ZONAL FLOW AS DEVELOPING WITH HEIGHT RISES OF 50 TO 90 M AT H5 NOTED. THE NEXT SYSTEM IDENTIFIABLE SHORTWAVE TROUGH ON THE 00Z UPPER AIR ANALYSIS WAS MOVING INTO NRN CA. THE DEVELOPING ZONAL FLOW WAS LEADING TO LEE TROUGHING OVER THE HIGH PLAINS EARLY THIS MORNING AND THE WINDS ACROSS CNTRL AND WRN NEB HAVE BECOME SOUTHEAST. AS THE HEIGHT RISES MOVE INTO THE PLAINS TODAY THE LOW- TO MID-LEVEL WAA WILL INCREASE THROUGH THE DAY ALLOWING FOR THE AREA OF +15 C H85 DEW POINTS FROM ERN KS INTO THE TX PANHANDLE TO MOVE NWD INTO CNTRL NEB. LAPSE RATES WILL BE STEEPENING ALOFT...BUT POINT FORECAST SOUNDINGS INDICATE LITTLE IN THE WAY OF AN EML OR CAPPING INVERSION DEVELOPING TODAY. THUS AS THIS MOISTURE RETURNS INTO AN UPCAPPED ATMOSPHERE CHARACTERIZED BY AROUND 1500-2000 J/KG OF MLCAPE ISO TO SCT TSRA WILL LIKELY DEVELOP BY LATE AFTERNOON OVER THE NW CWA CLOSEST TO THE AREA OF STRONGEST WAA AND A WEAK SFC TROUGH. OPERATIONAL MODELS APPEAR OVERDONE WITH QPF GIVEN THE HEIGHT RISES EXPECTED THROUGH THE DAY. NEVERTHELESS CHC POPS STILL APPEAR WARRANTED OVER THE CNTRL AND NRN CWA. SOME OF THESE WILL LIKELY CONT INTO THE OVERNIGHT HOURS BUT THE LACK OF A STRONGER LOW-LEVEL JET AND MARGINAL MOISTURE/INSTABILITY WE THINK MUCH OF THE ACTIVITY MAY TEND TO DIMINISH DURING THE LATE EVENING. MOST OF THE DAY ON SAT SHOULD BE DRY ACRS THE FA BUT MOISTURE RETURN WILL CONT...AND WITH MID-LEVEL LAPSE RATES INCREASING...GREATER INSTABILITY WILL LIKELY DEVELOP ACROSS THE FA. AT THE MOMENT IT APPEARS THAT THE MOST LIKELY SCENARIO IS FOR THUNDERSTORMS TO DEVELOP ALONG THE SURFACE TROUGH OVER SOUTHERN SD INTO WRN NEB AND ROLL EAST SAT NIGHT THRU THE CWA. THE CONFIDENCE IN THE FORECAST DECREASES BY SUNDAY WITH MODEL DISAGREEMENT INCREASING AND THE EFFECTS OF A COUPLE OF DAYS OF SCT CONVECTION UNKNOWN. THOUGH MODELS CONT TO ADVERTISE STRONGER FORCING FOR ASCENT MOVING INTO THE HIGH PLAINS BY SUN. SOME STORMS CAN`T BE RULED OUT DURING THE DAY ON SUNDAY...BUT MOST OF THE FOCUS MAY STILL BE WEST OF OUR CWA DURING THE DAY CLOSER TO THE LARGE-SCALE ASCENT. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 AM CDT FRI JUN 20 2014 WE WILL CONT WITH THE LIKELY POPS ON SUNDAY NIGHT INTO MON MORNING AS THE PREVIOUSLY MENTIONED FORCING MOVES ACROSS THE CNTRL PLAINS WITH THE PATTERN FAVORABLE FOR AN MCS TO MOVE EAST ACROSS THE AREA...ESPECIALLY IN THE SRN CWA INTO MON MORNING. THE GLOBAL MODELS ARE THEN STILL IN DECENT AGREEMENT IN THE SUN NIGHT SHORTWAVE TO CARVE OUT A PROGRESSIVE TROUGH IN THE GREAT LAKES AND ALLOW FOR NORTHWEST FLOW OVER THE CNTRL/NRN PLAINS. THIS SHOULD ALLOW THE FOCUS FOR CONVECTION TO SHIFT WEST TO THE HIGH PLAINS AND WE FEEL THAT THE PERIOD TUE-THU WILL BE DRY OVER THE FA. TEMPERATURES SHOULD GENERALLY BE SEASONABLE THROUGH THE PERIOD. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1244 PM CDT FRI JUN 20 2014 TIMING OF CONVECTION THIS AFTERNOON AND EVENING WILL BE THE MAIN UNCERTAINTY IN THE FORECAST. EARLIER CONVECTION OVER CENTRAL NEBRASKA HAS RAPIDLY COLLAPSED SINCE 17Z AND UNSURE OF ANY SPECIFIC FORCING TO KEY ON THROUGH 00Z. HRRR INDICATES ADDITIONAL DEVELOPMENT AFTER 20Z SO HAVE FOLLOWED THIS IDEA IN LATEST FORECAST. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...BOUSTEAD LONG TERM...BOUSTEAD AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT FRI JUN 20 2014 .SYNOPSIS...A SERIES OF UPPER LEVEL DISTURBANCES WILL TRACK SOUTHEAST ACROSS THE MID ATLANTIC AND CAROLINAS THIS EVENING AND SATURDAY... PROPELLING A BACK DOOR COLD FRONT SOUTHWARD THROUGH CENTRAL NORTH CAROLINA BY SATURDAY NIGHT. && .NEAR TERM /THROUGH SATURDAY NIGHT/... AS OF 1045 AM FRIDAY... JUST MINOR ADJUSTMENTS MADE TO THE CURRENT FORECAST FOR THE REST OF TODAY. A BATCH OF CONVECTION NOW PUSHING INTO NW NC IS EXPECTED TO CONTINUE PROPAGATING TOWARD THE SE FOR THE NEXT SEVERAL HOURS... FOLLOWING THE WEAK STEERING FLOW NOTED ON 12Z UPPER AIR ANALYSES... ALTHOUGH CONVECTIVE GROWTH AND PROPAGATION TODAY WILL BE LARGELY DRIVEN BY COLD POOL MOTION. THE COLUMN HAS YET TO FULLY DESTABILIZE THIS MORNING DESPITE BRIGHT SUNSHINE (OVER ALL BUT THE FAR NE)... AS MILD MID LEVEL TEMPS ARE THUS FAR HOLDING MLCAPE TO 500 J/KG OR LOWER WITH REMAINING CINH. THE WARMTH ALOFT WILL MAKE FOR WEAK MID LEVEL LAPSE RATES... AND WITH DEEP LAYER SHEAR REMAINING QUITE WEAK... ORGANIZED CONVECTION WILL BE TOUCH TO ACHIEVE. LATEST SURFACE ANALYSIS SHOWS A WEAK FRONTAL ZONE ACROSS NE NC... AND IT IS ALONG AND NE OF THIS ZONE THAT LOW CLOUDS MAY HINDER HEATING AND CURB INSTABILITY TO LIMIT SHOWER/STORM COVERAGE... AND WILL MAINTAIN THE LOWEST POPS HERE... WITH BETTER COVERAGE OVER THE NW PIEDMONT BY EARLY/MID AFTERNOON SPREADING OVER THE SOUTHERN THIRD OF CENTRAL NC DURING THE LATE AFTERNOON INTO EARLY EVENING. THIS SCENARIO IS REPRESENTED WELL BY THE LATEST HIGH-RES WRF-ARW AND WRF-NMM RUNS. THE NAM/GFS DEPICT MODERATE INSTABILITY ONLY IN THE SE CWA THIS AFTERNOON... REASONABLE GIVEN THE OVERALL LOW MID LEVEL LAPSE RATES... AND WITH ANY CONVECTION LIKELY TO BE PULSE IN NATURE... THE RISK OF SEVERE STORMS WILL BE SMALLER THAN IN RECENT DAYS. DOWNDRAFT CAPE IS CURRENTLY VERY LOW BUT THE RAP PREDICTS IT TO RISE RAPIDLY TO OVER 1000 J/KG BY 20Z... SO WE CAN`T RULE OUT A DAMAGING DOWNBURST GUST WITH ANY STORMS. STORM COVERAGE IS STILL EXPECTED TO RISE BY EVENING WITH THE APPROACH OF A MID LEVEL PERTURBATION FROM THE NNW... THAT WILL TRACK SOUTHWARD THROUGH THE AREA... AND WILL HOLD ONTO GOOD CHANCE POPS STARTING THIS EVENING MAINLY IN THE NORTH. EARLIER FORECAST HIGHS FROM 88 (NE) TO 95 (SW) LOOK GOOD AND ARE IN LINE WITH LATEST TRENDS. -GIH PREVIOUS 255 AM DISCUSSION FOR TONIGHT: MODEL GUIDANCE INDICATES RELATIVELY ROBUST SHORTWAVE ENERGY WILL TRACK SOUTHEAST INTO THE MID- ATLANTIC AND CAROLINAS LATE THIS EVENING AND TONIGHT (03-12Z SAT). DURING THIS TIME...LOW-LEVEL FLOW WILL BACK/STRENGTHEN TO 10-15 KT IN RESPONSE TO DPVA AND 20-30 METER 12-HR H5 HEIGHT FALLS...RESULTING IN WEAK LOW-LEVEL WARM ADVECTION BETWEEN 06-12Z AND 500-1000 J/KG OF MUCAPE IN ASSOC/W AN INCREASINGLY WARM/MOIST LOW-LEVEL AIRMASS AND ~6 C/KM MID-LEVEL LAPSE RATES. WITH THE ABOVE IN MIND...WILL INDICATE A 20-30% CHANCE OF CONVECTION ACROSS THE AREA THIS AFTERNOON...WITH INCREASING CHANCES (30-50%) OVERNIGHT. SATURDAY IS EXPECTED TO BE CONVECTIVELY ACTIVE AGAIN AS THE FINAL SHOT OF UPPER LEVEL ENERGY IS EXPECTED TO CLIP THE REGION AS THE MAIN LOW LEVEL FOCUS (THE COLD FRONT) SAGS SOUTHWARD THROUGH THE REGION. THE COMBINATION OF THE PIEDMONT TROUGH AND THE SOUTHWARD MOVING COLD FRONT SHOULD INDUCE GOOD CONVERGENCE. STRONG SURFACE HEATING SHOULD ADD PLENTY OF ENERGY FOR LIFT. THEREFORE... ISOLATED SEVERE STORMS WILL BE POSSIBLE WITH THE MAIN THREAT OF DAMAGING WIND. WE WILL BUMP THE POP UPWARD INTO THE LIKELY CATEGORY DURING THE AFTERNOON AND EVENING... TAPERING FROM THE NORTH DURING SATURDAY EVENING. LOCALLY HEAVY RAIN AND FREQUENT LIGHTNING WILL POSE WEATHER HAZARDS. HIGHS GENERALLY 85-90 EXCEPT LOWER 90S OVER THE SANDHILLS BEFORE THE CONVECTION OCCURS. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 230 PM FRIDAY... SURFACE LOW PRESSURE WILL BE MOVING OFFSHORE TO BEGIN THE DAY ON SUNDAY...WITH HIGH PRESSURE GRADUALLY BUILDING EAST AND DOWN THE EAST COAST THROUGH MONDAY. THIS WILL PUSH A FRONT FURTHER SOUTH OF THE FORECAST AREA...LIKELY INTO SC/GA. IN ADDITION...SHORTWAVE RIDGING WILL ALSO BUILD EAST OVER THE REGION. THEREFORE...THIS TIME FRAME OF ENTIRE FORECAST PERIOD IS WHEN PRECIP CHANCES WILL BE THE LOWEST... ALTHOUGH NON-ZERO. SUNDAY SHOULD BE THE DRIEST DAY (WITH ONLY A FEW ISOLATED STORMS EXPECTED)...THEN MAYBE SOME HIGHER CHANCES ACROSS THE WEST ON MONDAY AS THE HIGH STARTS TO PULL AWAY AND MOISTURE BEGINS TO INCREASE ON THE BACK SIDE OF THE DEPARTING HIGH. TEMPS WILL BE A SEVERAL DEGREES LOWER THAN PREVIOUS DAYS BEHIND THE FRONT...WITH HIGHS EXPECTED TO BE IN THE MID/UPPER 80S TO NEAR 90 DEGREES AND OVERNIGHT LOWS IN THE MID/UPPER 60S TO NEAR 70 DEGREES. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 230 PM FRIDAY... PRECIP CHANCES...MOSTLY DIURNAL IN NATURE...WILL BEGIN TO INCREASE ON TUESDAY AND THEN PERSIST FOR THE REMAINDER OF THE WEEK AS MOISTURE INCREASES WITHIN THE RETURN FLOW THAT SETS UP ON THE BACKSIDE OF THE DEPARTING HIGH. IN ADDITION...FLOW ALOFT WILL BECOME SOUTHWESTERLY (THUS INCREASING DEEP LAYER MOISTURE) AS LARGE SCALE TROUGHING MOVES OVER THE GREAT LAKES AND MS RIVER VALLEY. ADDITIONALLY...TEMPS WILL CLIMB A FEW DEGREES...WITH HIGHS GENERALLY IN THE UPPER 80S TO LOWER 90S AND OVERNIGHT LOWS IN THE UPPER 60S TO LOWER 70S. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 130 PM FRIDAY... LATEST SURFACE MAP SHOWS A FRONTAL ZONE EXTENDING FROM NEAR CHI ACROSS VA... WITH A SECONDARY WEAKER FRONT SOUTH OF HERE ACROSS NE NC. MVFR CIGS OVER THE NE CWA (JUST NE OF RWI) HAVE LARGELY MIXED OUT AND/OR RISEN ABOVE 3 KFT... AND CONVECTIVE CLOUDS THAT HAVE DEVELOPED THUS FAR THIS AFTERNOON ARE LIKEWISE BASED ABOVE 3 KFT AGL. HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE TO DOMINATE THROUGH THIS EVENING... WITH A BATCH OF MID CLOUDS POISED TO AFFECT INT/GSO THIS AFTERNOON... ALTHOUGH CERTAINLY SUB-VFR CONDITIONS AND GUSTY/VARIABLE WINDS ARE LIKELY IN AND NEAR SCATTERED STORMS. ANY STORMS THAT FORM ARE MOST LIKELY TO AFFECT INT 18Z-22Z... GSO 19Z- 23Z... AND RDU/RWI/FAY 22Z-03Z... BUT THE STORM RISK IS NOT RESTRICTED TO THESE WINDOWS. IN FACT... THE APPROACH OF A DISTURBANCE INTO NORTHERN NC LATE TONIGHT IS LIKELY TO BRING ANOTHER ROUND OF ISOLATED TO SCATTERED STORMS WARRANTING A VCTS MENTION OVERNIGHT. WITH LIGHT WINDS AND HIGH HUMIDITY AND POSSIBLY A WET GROUND LATE TONIGHT... THERE IS A CHANCE OF MVFR FOG AND IFR STRATUS AT RWI/FAY IN THE FEW HOURS BEFORE DAYBREAK SAT. THE AFOREMENTIONED DISTURBANCE WILL SINK INTO SRN/ERN PARTS OF NC SAT... A COULD SPAWN SHOWER/STORM DEVELOPMENT NEAR FAY PRIOR TO 18Z. LOOKING BEYOND 18Z SAT: VFR CONDITIONS AND LIGHT SURFACE WINDS WILL DOMINATE INTO THE EVENING... WITH THE EXCEPTION OF IN AND NEAR ANY SCATTERED STORMS WHERE GUSTY/VARIABLE WINDS AND SUB-VFR CONDITIONS COULD BRIEFLY OCCUR. GOOD CHANCE OF SUB-VFR CIGS LATE SAT NIGHT INTO SUN MORNING. EXPECT A RELATIVE MINIMUM IN STORM CHANCES ON SUNDAY AS THE FRONT SETTLES TO OUR SOUTH BEFORE WASHING OUT AND DISSIPATING. DAILY SHOWERS/STORMS RETURN MON-WED... MAINLY IN THE TYPICAL AFTERNOON THROUGH EARLY EVENING HOURS. SUB-VFR FOG/STRATUS POSSIBLE AT ALL SITES EARLY TUE AND EARLY WED MORNING. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD/VINCENT SHORT TERM...KRD LONG TERM...KRD AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
130 PM EDT FRI JUN 20 2014 .SYNOPSIS...A SERIES OF UPPER LEVEL DISTURBANCES WILL TRACK SOUTHEAST ACROSS THE MID ATLANTIC AND CAROLINAS THIS EVENING AND SATURDAY... PROPELLING A BACK DOOR COLD FRONT SOUTHWARD THROUGH CENTRAL NORTH CAROLINA BY SATURDAY NIGHT. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 1045 AM FRIDAY... JUST MINOR ADJUSTMENTS MADE TO THE CURRENT FORECAST FOR THE REST OF TODAY. A BATCH OF CONVECTION NOW PUSHING INTO NW NC IS EXPECTED TO CONTINUE PROPAGATING TOWARD THE SE FOR THE NEXT SEVERAL HOURS... FOLLOWING THE WEAK STEERING FLOW NOTED ON 12Z UPPER AIR ANALYSES... ALTHOUGH CONVECTIVE GROWTH AND PROPAGATION TODAY WILL BE LARGELY DRIVEN BY COLD POOL MOTION. THE COLUMN HAS YET TO FULLY DESTABILIZE THIS MORNING DESPITE BRIGHT SUNSHINE (OVER ALL BUT THE FAR NE)... AS MILD MID LEVEL TEMPS ARE THUS FAR HOLDING MLCAPE TO 500 J/KG OR LOWER WITH REMAINING CINH. THE WARMTH ALOFT WILL MAKE FOR WEAK MID LEVEL LAPSE RATES... AND WITH DEEP LAYER SHEAR REMAINING QUITE WEAK... ORGANIZED CONVECTION WILL BE TOUCH TO ACHIEVE. LATEST SURFACE ANALYSIS SHOWS A WEAK FRONTAL ZONE ACROSS NE NC... AND IT IS ALONG AND NE OF THIS ZONE THAT LOW CLOUDS MAY HINDER HEATING AND CURB INSTABILITY TO LIMIT SHOWER/STORM COVERAGE... AND WILL MAINTAIN THE LOWEST POPS HERE... WITH BETTER COVERAGE OVER THE NW PIEDMONT BY EARLY/MID AFTERNOON SPREADING OVER THE SOUTHERN THIRD OF CENTRAL NC DURING THE LATE AFTERNOON INTO EARLY EVENING. THIS SCENARIO IS REPRESENTED WELL BY THE LATEST HIGH-RES WRF-ARW AND WRF-NMM RUNS. THE NAM/GFS DEPICT MODERATE INSTABILITY ONLY IN THE SE CWA THIS AFTERNOON... REASONABLE GIVEN THE OVERALL LOW MID LEVEL LAPSE RATES... AND WITH ANY CONVECTION LIKELY TO BE PULSE IN NATURE... THE RISK OF SEVERE STORMS WILL BE SMALLER THAN IN RECENT DAYS. DOWNDRAFT CAPE IS CURRENTLY VERY LOW BUT THE RAP PREDICTS IT TO RISE RAPIDLY TO OVER 1000 J/KG BY 20Z... SO WE CAN`T RULE OUT A DAMAGING DOWNBURST GUST WITH ANY STORMS. STORM COVERAGE IS STILL EXPECTED TO RISE BY EVENING WITH THE APPROACH OF A MID LEVEL PERTURBATION FROM THE NNW... THAT WILL TRACK SOUTHWARD THROUGH THE AREA... AND WILL HOLD ONTO GOOD CHANCE POPS STARTING THIS EVENING MAINLY IN THE NORTH. EARLIER FORECAST HIGHS FROM 88 (NE) TO 95 (SW) LOOK GOOD AND ARE IN LINE WITH LATEST TRENDS. -GIH PREVIOUS 255 AM DISCUSSION FOR TONIGHT: MODEL GUIDANCE INDICATES RELATIVELY ROBUST SHORTWAVE ENERGY WILL TRACK SOUTHEAST INTO THE MID- ATLANTIC AND CAROLINAS LATE THIS EVENING AND TONIGHT (03-12Z SAT). DURING THIS TIME...LOW-LEVEL FLOW WILL BACK/STRENGTHEN TO 10-15 KT IN RESPONSE TO DPVA AND 20-30 METER 12-HR H5 HEIGHT FALLS...RESULTING IN WEAK LOW-LEVEL WARM ADVECTION BETWEEN 06-12Z AND 500-1000 J/KG OF MUCAPE IN ASSOC/W AN INCREASINGLY WARM/MOIST LOW-LEVEL AIRMASS AND ~6 C/KM MID-LEVEL LAPSE RATES. WITH THE ABOVE IN MIND...WILL INDICATE A 20-30% CHANCE OF CONVECTION ACROSS THE AREA THIS AFTERNOON...WITH INCREASING CHANCES (30-50%) OVERNIGHT. -VINCENT && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 120 AM FRIDAY... SATURDAY IS EXPECTED TO BE CONVECTIVELY ACTIVE AGAIN AS THE FINAL SHOT OF UPPER LEVEL ENERGY IS EXPECTED TO CLIP THE REGION AS THE MAIN LOW LEVEL FOCUS (THE COLD FRONT) SAGS SOUTHWARD THROUGH THE REGION. THE COMBINATION OF THE PIEDMONT TROUGH AND THE SOUTHWARD MOVING COLD FRONT SHOULD INDUCE GOOD CONVERGENCE. STRONG SURFACE HEATING SHOULD ADD PLENTY OF ENERGY FOR LIFT. THEREFORE... ISOLATED SEVERE STORMS WILL BE POSSIBLE WITH THE MAIN THREAT OF DAMAGING WIND. WE WILL BUMP THE POP UPWARD INTO THE LIKELY CATEGORY DURING THE AFTERNOON AND EVENING... TAPERING FROM THE NORTH DURING SATURDAY EVENING. LOCALLY HEAVY RAIN AND FREQUENT LIGHTNING WILL POSE WEATHER HAZARDS. HIGHS GENERALLY 85-90 EXCEPT LOWER 90S OVER THE SANDHILLS BEFORE THE CONVECTION OCCURS. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 105 AM FRIDAY... THE EXTENDED FORECAST GENERALLY REMAINS THE SAME AS IN PREVIOUS DISCUSSIONS. THE MAIN COLD FRONT SHOULD STALL SOUTH OF THE REGION... DEEP INTO SC/GA SUNDAY AND MONDAY. THIS WOULD HAVE SOME IMPACTS ON SENSIBLE WEATHER INCLUDING LOWER POP SUNDAY AND MONDAY... BEFORE RAMPING UP AGAIN MIDWEEK. IN ADDITION... THE TEMPERATURES WILL BE COOLER THAN IN THE RECENT EARLY HEAT SPELL SUNDAY AND MONDAY AS THE WINDS BECOME NE-E. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 130 PM FRIDAY... LATEST SURFACE MAP SHOWS A FRONTAL ZONE EXTENDING FROM NEAR CHI ACROSS VA... WITH A SECONDARY WEAKER FRONT SOUTH OF HERE ACROSS NE NC. MVFR CIGS OVER THE NE CWA (JUST NE OF RWI) HAVE LARGELY MIXED OUT AND/OR RISEN ABOVE 3 KFT... AND CONVECTIVE CLOUDS THAT HAVE DEVELOPED THUS FAR THIS AFTERNOON ARE LIKEWISE BASED ABOVE 3 KFT AGL. HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE TO DOMINATE THROUGH THIS EVENING... WITH A BATCH OF MID CLOUDS POISED TO AFFECT INT/GSO THIS AFTERNOON... ALTHOUGH CERTAINLY SUB-VFR CONDITIONS AND GUSTY/VARIABLE WINDS ARE LIKELY IN AND NEAR SCATTERED STORMS. ANY STORMS THAT FORM ARE MOST LIKELY TO AFFECT INT 18Z-22Z... GSO 19Z- 23Z... AND RDU/RWI/FAY 22Z-03Z... BUT THE STORM RISK IS NOT RESTRICTED TO THESE WINDOWS. IN FACT... THE APPROACH OF A DISTURBANCE INTO NORTHERN NC LATE TONIGHT IS LIKELY TO BRING ANOTHER ROUND OF ISOLATED TO SCATTERED STORMS WARRANTING A VCTS MENTION OVERNIGHT. WITH LIGHT WINDS AND HIGH HUMIDITY AND POSSIBLY A WET GROUND LATE TONIGHT... THERE IS A CHANCE OF MVFR FOG AND IFR STRATUS AT RWI/FAY IN THE FEW HOURS BEFORE DAYBREAK SAT. THE AFOREMENTIONED DISTURBANCE WILL SINK INTO SRN/ERN PARTS OF NC SAT... A COULD SPAWN SHOWER/STORM DEVELOPMENT NEAR FAY PRIOR TO 18Z. LOOKING BEYOND 18Z SAT: VFR CONDITIONS AND LIGHT SURFACE WINDS WILL DOMINATE INTO THE EVENING... WITH THE EXCEPTION OF IN AND NEAR ANY SCATTERED STORMS WHERE GUSTY/VARIABLE WINDS AND SUB-VFR CONDITIONS COULD BRIEFLY OCCUR. GOOD CHANCE OF SUB-VFR CIGS LATE SAT NIGHT INTO SUN MORNING. EXPECT A RELATIVE MINIMUM IN STORM CHANCES ON SUNDAY AS THE FRONT SETTLES TO OUR SOUTH BEFORE WASHING OUT AND DISSIPATING. DAILY SHOWERS/STORMS RETURN MON-WED... MAINLY IN THE TYPICAL AFTERNOON THROUGH EARLY EVENING HOURS. SUB-VFR FOG/STRATUS POSSIBLE AT ALL SITES EARLY TUE AND EARLY WED MORNING. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD/VINCENT SHORT TERM...32 LONG TERM...32 AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1256 PM CDT FRI JUN 20 2014 .UPDATE... ISSUED AT 1254 PM CDT FRI JUN 20 2014 NO CHANGES FROM PREVIOUS UPDATE. UPDATE ISSUED AT 955 AM CDT FRI JUN 20 2014 NO MAJOR CHANGES TO THIS UPDATE. HAVE ADDED SOME THUNDER INTO THE FAR SOUTHWEST THIS AFTERNOON...AND EXTENDED THUNDER CHANCES IN ALL AREAS THROUGH 00Z. A STRONG SHORTWAVE...UPPER SPEED MAX AND INSTABILITY SHOULD MEAN SCATTERED STORMS THIS AFTERNOON. THE DEEP LAYERED SHEAR IS STRONG...AROUND 50-60KT...SO IF SFC DEWPOINTS CAN RISE INTO THE MID 60S...CAPES AROUND 1500 J/KG WOULD OCCUR. THIS WOULD BE ENOUGH FOR SOME SEVERE STORMS...WITH THE MAIN THREATS LARGE HAIL AND DAMAGING WINDS. IT APPEARS THAT STORM INITIATION SHOULD OCCUR NEAR THE VALLEY...WITH THE BEST SEVERE THREAT EAST OF THE VALLEY. THIS IS IN LINE WITH THE LATEST SPC SLIGHT RISK AREA MAINLY IN MN. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 335 AM CDT FRI JUN 20 2014 PRECIP CHANCES AND STRENGTH WILL BE THE MAIN FORECAST ISSUE FOR THE SHORT TERM. UPPER LOW CURRENTLY CENTERED ALONG THE MT/CANADIAN BORDER...AND MODELS ARE IN PRETTY GOOD AGREEMENT ON TRACKING THE UPPER LOW SLOWLY EASTWARD TODAY. THERE WILL BE A STRONG VORT MAX/JET STREAK COMING INTO THE CWA BY THIS AFTERNOON. WITH THE STRONG UPPER LEVEL SYSTEM COMING THROUGH...BULK SHEAR VALUES WILL BE VERY STRONG...UP IN THE 50 TO 60 KT RANGE ACROSS PORTIONS OF THE SOUTHERN CWA. MORE IN QUESTION WILL BE THE INSTABILITY. THE NAM BRINGS CAPE VALUES OF 1500-2000 J/KG INTO OUR SOUTHEASTERN COUNTIES...AND THE RUC IS SIMILAR BUT MORE IN THE 1000-1500 RANGE. STRATUS OVER THE EAST HAS BEEN CLEARING OUT AND FOG HAS BEEN NOT VERY WIDESPREAD...SO THERE SHOULD BE AT LEAST A LITTLE BIT OF HEATING THIS AFTERNOON. HOWEVER...CLOUDS HAVE BEEN INCREASING OVER THE WESTERN COUNTIES AND REGIONAL RADAR SHOWS QUITE A BIT OF ACTIVITY OVER WESTERN ND WITH THE JET STREAK COMING OUT. THE UPPER SUPPORT MAY BE INTO THE ARE BEFORE WE CAN DESTABILIZE ENOUGH. FOR THAT REASON...BUMPED UP POPS AND WILL MENTION CHANCE OF SEVERE IN THE HWO...BUT WILL KEEP A SEVERE MENTION OUT OF THE GRIDS FOR THE TIME BEING. TONIGHT...THE MAIN UPPER LOW WILL LIFT NORTHEASTWARD INTO CANADA. A FEW SHOWERS MAY BE HANGING AROUND THE NORTHEASTERN COUNTIES EARLY ON BUT THINK THERE WILL BE A BREAK IN PRECIP FOR MUCH OF THE NIGHT. CONTINUED TO KEEP TEMPS OVERNIGHT IN THE UPPER 50S TO LOW 60S. SUNSHINE AND SOUTH TO SOUTHWESTERLY SFC WINDS SHOULD HELP HIGHS ON SATURDAY REACH THE 80S IN MANY AREAS. BY SATURDAY AFTERNOON...A WEAK SHORTWAVE PUSHING IN FROM THE WEST WILL HELP BRING A SFC TROUGH AXIS INTO CENTRAL ND AND THERE SHOULD BE SOME CONVECTIVE ACTIVITY ALONG WITH IT. BULK SHEAR VALUES ARE QUITE A BIT LOWER BUT THERE SHOULD BE DECENT INSTABILITY. WILL CONTINUE TO KEEP CHANCE POPS GOING. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM CDT FRI JUN 20 2014 SATURDAY NIGHT THROUGH SUNDAY NIGHT...MORE SHORTWAVES MOVE THROUGH AS THE ACTIVE PATTERN CONTINUES UNDER WEST TO SOUTHWESTERLY FLOW ALOFT. THE MAIN SFC TROUGH WILL MOVE OFF TO THE EAST SATURDAY NIGHT INTO SUNDAY...WITH SOME WEAK COLD AIR ADVECTION BEHIND IT. THINK THAT BEST CHANCES FOR PRECIP WILL BE LATE SATURDAY NIGHT INTO SUNDAY AS THIS FEATURE MOVES THROUGH. KEPT 20-40 POPS GOING BEFORE TAPERING THEM OFF SUNDAY NIGHT. TEMPS ON SUNDAY WILL BE A BIT LOWER THAN SATURDAY...MAINLY IN THE 70S. MONDAY THROUGH THURSDAY...THIS PERIOD WILL BE CATEGORIZED BY MEAN ZONAL FLOW...THE UPPER LOW HAVING DEPARTED TO THE EAST. SEVERAL SHORT WAVE RIPPLES LIKELY TO MOVE THROUGH THIS FLOW...OFFERING PCPN CHANCES PERHAPS TUESDAY AND AGAIN ON THURSDAY. BELIEVE THE BEST BET FOR TOTALLY DRY WILL COME MIDWEEK...AS BOTH 00Z GFS/ECMWF DEPICT A BUBBLE OF CANADIAN HIGH PRESSURE FOR WEDNESDAY. LOOKS LIKE WARMEST DAY WILL BE MONDAY WITH COOLER READINGS UNDER MORE CLOUD COVER TUESDAY...RECOVERING TO NEAR AVERAGE FOR LATE JUNE BY WED/THUR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1254 PM CDT FRI JUN 20 2014 EXPECT VFR CONDITIONS THRU THE FORECAST PERIOD. OTHERWISE...MID LEVEL CLOUDS WILL INCREASE ACROSS THE NORTHERN PART OF THE AREA AS AN UPPER LEVEL DISTURBANCE CROSSES JUST SOUTH OF THE INTERNATIONAL BORDER. LOOKING FOR MAINLY SHOWERS EARLY IN THE FCST PERIOD AS THE UPPER DISTURBANCE MOVES EAST. HOWEVER...A GREATER RISK EXISTS FOR SCATTERED TSTMS LATER THIS AFTERNOON...WITH A COMBINED INCREASE IN SFC HEATING AND ENERGY ALOFT. WINDS ARE EXPECTED TO REMAIN GENERALLY SOUTH TO SOUTHWEST AS SFC LOW PRESSURE CONTINUES TO AFFECT THE AREA. && .HYDROLOGY... ISSUED AT 1254 PM CDT FRI JUN 20 2014 RIVER FORECASTS ARE ON TRACK AS RISES CONTINUE AS A RESULT OF THE RECENT RAINFALL. THE WILD RICE RIVER AT ABERCROMBIE IS NEARING CREST WITHIN MODERATE FLOOD STAGE...AND FARGO AND OSLO ON THE RED RIVER ARE EXPECTED TO REACH MODERATE FLOOD STAGE. THE FLOOD WARNING ON THE BUFFALO RIVER AT HAWLEY HAS BEEN CANCELLED AS CURRENT FORECASTS INDICATE GRADUALLY FALLING STAGES. NO OTHER SIGNIFICANT CHANGES WERE MADE TO FORECAST POINTS. AN AREAL FLOOD WARNING REMAINS IN EFFECT FOR EAST CENTRAL BELTRAMI COUNTY WITH THE TAMARAC RIVER OUT OF ITS BANKS NEAR WASKISH. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...JR LONG TERM...WJB AVIATION...HOPKINS HYDROLOGY...HOPKINS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
445 PM EDT FRI JUN 20 2014 .SYNOPSIS... AN UPPER RIDGE WILL CONTINUE TO BREAK DOWN THROUGH THIS EVENING RESULTING IN WEAKENING HIGH PRESSURE CURRENTLY IN PLACE OVER THE AREA. THIS SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK. A TYPICAL WARM SUMMERLIKE PATTERN WILL CONTINUE THROUGH NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... 430 PM EDT UPDATE...LOW SFC TD/S AND A NOTABLE LOBE OF DNVA HAS KEPT CONVECTION MINIMAL AND RELATIVELY SHORT LIVED ACROSS CWFA THUS FAR THIS AFTERNOON. THE STORMS TO THE EAST HAVE BEEN ABLE TO TAP INTO HIGH VALUES OF DCAPE AND PRODUCE SEVERE WINDS...BUT THE REMAINING CELLS HAVE HAD FAIRLY NARROW AND WEAKER UPDRAFTS. THE NAM12 HAS A GOOD HANDLE ON THE UPPER VORT FIELD AND WILL FOLLOW IT/S GUIDANCE WRT TO POPS AND CONVEC INITIATION OVER THE NEXT COUPLE HRS. THE UPSTATE HAS THE LOWEST INSTABILITY COMBINED WITH NEGATIVE ULVL FORCING...SO POPS WILL BE LOWERED TO ISOL THERE...ACROSS THE SRN NC FTHILLS. THE BEST CHANCE FOR NEW DEVELOPMENT WILL BE ACROSS THE NC MTN SPINE WHERE ENHANCED CONVECTION SHOULD MOVE IN AND LIKELY WEAKEN THROUGH 8 PM. AS OF 200 PM EDT...CELLS NOW LINING UP ALONG THE BLUE RIDGE AS A WEAK RIPPLE ROUNDS THE RIDGE OVER THE LOWER MISSISSIPPI VALLEY AND MOVES SEWD ACRS THE AREA. HRRR SEEMS TO HAVE PICKED UP ON THIS ACTIVITY AND ALLOWS IT TO PROPAGATE SEWD SLIGHTLY BEFORE DISSIPATING...POSSIBLY DUE TO DOWNSLOPING BY THE NW FLOW ABOVE THE BOUNDARY LAYER. THE NCEP HIRES WINDOW /NMM/ SUGGESTS THE SAME...BUT DEVELOPS A NEW ROUND OF CONVECTION IN THE MTNS BEHIND IT WHICH FILLS IN THE SAME AREA. DEWPOINTS HAVE MIXED OUT SLIGHTLY AS EXPECTED...BUT NOT ENOUGH TO KEEP SBCAPE FROM RISING TO 2000 J OR MORE PER SPC MESOANALYSIS. NO SEVERE REPORTS HAVE YET BEEN RECEIVED BUT A FEW STORMS HAVE MET WARNING CRITERIA. I AM NO LONGER CONFIDENT IN OUR EARLIER EXPECTATIONS THAT WE WOULD NOT GET UNSTABLE ENOUGH FOR LARGE HAIL TO BE MUCH OF A CONCERN...BUT PROFILES REMAIN DRY ENOUGH FOR DCAPES OF 700-1000 J SUPPORTING A MICROBURST THREAT. CHC RANGE POPS HAVE BEEN MAINTAINED ACRS MOST OF THE AREA...BUT NOW THE GREATEST CHANCE APPEARS TO BE DOWNSTREAM OF THE CURRENT ACTIVITY. SOME MODELS INCLUDING THE NAM TRY TO DEVELOP ANOTHER ROUND OF CONVECTION AFTER SUNSET...BUT PROFILES HAVE ENOUGH CIN THAT I THINK THIS IS UNLIKELY IN THE PRESENCE OF SUCH WEAK FORCING. POPS DIMINISH EAST OF THE MTNS BY LATE EVENING. MAIN FORECAST CHALLENGE FOR THE OVERNIGHT IS WHETHER ANY ACTIVITY WILL MOVE INTO OUR AREA FROM THE WEST...AS SUGGESTED BY SOME OF THE MESO GUIDANCE AND THE 12Z NAM. THE NAM SHOWS AN MCV DEVELOPING OVER THE OHIO VALLEY LATE THIS AFTN AND PROGRESSING SEWD ACRS KY/TN...THE ORIGINAL CONVECTION DYING BUT THE MCV KICKING OFF NEW DEVELOPMENT ON THE WEST SLOPES OF THE MTNS WHICH THEN MOVES INTO NW NC AROUND DAYBREAK. SO FAR THE NAM DEPICTION OF THE ORIGINATING CONVECTION SEEMS OVERDONE...SO WILL ONLY GIVE THIS SMALL WEIGHT IN THE FCST. CLOUD COVER PROGGED BY THE MODELS APPEARS MAINLY TO BE CONVECTIVE DEBRIS AND IT IS A BIT HARDER TO HEDGE ON THAT. THE NAM SUGGESTS DEEP RH WILL BE HIGHER ON SATURDAY...PROBABLY SINCE IT EXPECTS DEBRIS TO COME IN DURING THE MORNING. GFS PROFILES REALLY DO NOT LOOK TOO MUCH DIFFERENT FROM TODAY...THOUGH SBCAPE IS STILL LOWER DUE TO SLIGHTLY WEAKER LAPSE RATES. THE DIFFERENCE IS NOT ONLY IMPORTANT FOR THE POTENTIALLY SIGNIFICANT REDUCTION IN INSTABILITY DUE TO CLOUDIER SKIES...BUT FOR A REDUCTION IN DCAPE AND MITIGATED SEVERE RISK. SPC FEATURES A 5 PCT AREA JUST TO OUR EAST WHERE WEAK SHORTWAVE /THE POTENTIAL MCV/ WILL PASS OVER DURING PEAK HEATING. IT DOES APPEAR THE BEST PRECIP CHANCES OVERALL WILL BE DURING THE MORNING IN THE NORTHERN FA AND THEN OVER THE I-77 CORRIDOR DURING THE AFTN WHERE THE BEST BUOYANCY IS SUGGESTED. TEMPS TONIGHT AND TOMORROW WILL REMAIN A CATEGORY OR SO ABOVE CLIMO. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 200 PM FRIDAY...HEIGHTS WILL GRADUALLY FALL THROUGH EARLY NEXT WEEK...AS UPPER HIGH CONTINUES TO WEAKEN AND RETROGRADE TOWARDS THE WESTERN GULF OF MEXICO. THIS WILL ALSO ALLOW WEAK FRONTAL ZONE TO BACK DOOR ITS WAY THROUGH THE AREA BY SUNDAY...POSSIBLY INTRODUCING SLIGHTLY COOLER AND DRIER AIR. THIS IS NOT EXPECTED TO ELIMINATE INSTABILITY ENOUGH TO HALT DIURNAL CONVECTION...BUT COVERAGE OF SUNDAY AFTERNOON/EVENING CONVECTION IS EXPECTED TO BE MORE TYPICAL OF WHAT ONE WOULD EXPECT THIS TIME OF YEAR (30-40 POPS MTNS...20/30 PIEDMONT). BY MONDAY... SHORT TERM MODELS DEPICT ESTABLISHMENT OF AN E/SE FLOW IN ASSOCIATION WITH A WEAK INVERTED RIDGE ALONG THE EASTERN SEABOARD. THIS UPSLOPE FLOW COULD SUPPORT A BIT MORE IN THE WAY OF DIURNAL CONVECTION BY MONDAY AFTERNOON...SO POPS RETURN TO ABOVE CLIMO BY THIS TIME. WEAK SHEAR WITH HALFWAY DECENT STEERING FLOW SHOULD PRECLUDE ANYTHING MORE THAN A TYPICAL EARLY SUMMER PULSE SEVERE THREAT OR FLASH FLOODING THREAT SUNDAY. HOWEVER...HEAVY RAINFALL MAY BECOME AN ISSUE MONDAY...AS UPPER FLOW WEAKENS ABOVE THE LOW LEVEL SOUTHEAST FLOW...POSSIBLY FAVORING ANCHORING OF CELLS ACROSS PORTIONS OF THE HIGH TERRAIN. TEMPS ARE EXPECTED TO RETURN TO NEAR CLIMO BY MONDAY IN THE RELATIVELY COOL E/SE FLOW REGIME. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 130 PM EDT FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON TUESDAY WITH WEAK UPPER RIDGING OVER THE SE CONUS AND A LOW AMPLITUDE UPPER TROF DIGGING DOWN OVER OVER THE DAKOTAS AND MINNESOTA. OVER THE NEXT FEW DAYS...THE TROF SLOWLY PROPAGATES EASTWARD...YET IT DOES NOT APPEAR TO MAKE MUCH HEADWAY SOUTHWARD. THE LONG RANGE MODELS HAVE BEEN DIFFERING A FAIR AMOUNT WRT THE AMPLIFICATION OF THIS TROF...BUT ITS LOOKING LIKE THEY ARE LEANING MORE TOWARDS STRONGER RIDGING OVER OUR FCST AREA THRU DAY 7. THIS PATTERN LEAVES OUR AREA UNDER GENERALLY WEAK WEST TO SWLY STEERING FLOW THRU THE PERIOD. AT THE SFC...THE REGION WILL BE UNDER THE INFLUENCE OF THE BERMUDA HIGH FOR MOST OF THE PERIOD WITH A COLD FRONT APPROACHING THE CAROLINAS BY EARLY WED AND WASHING OUT AS IT MOVES OVER THE CWFA. IN ITS WAKE...WEAK CANADIAN HIGH PRESSURE TRIES TO PUSH SOUTHWARD FROM NEW ENGLAND BUT ITS PROGRESS IS SUPPRESSED BY THE BERMUDA HIGH. WITH THE COMBINATION OF SLY MOIST FLOW...A WEAKLY SHEARED ENVIRONMENT AND MODERATE DIURNAL BUOYANCY...WE STILL HAVE A SOLID CHANCE OF PULSE TYPE CONVECTION ACROSS MUCH OF THE REGION EACH DAY...FAVORING IN THE MTN ZONES OVERALL. TEMPERATURES SHOULD REMAIN FAIRLY STEADY WITH VALUES NEAR NORMAL OR POSSIBLE A FEW DEGREES WARMER. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... AT KCLT...SOME QUESTION WHETHER TSRA WILL BE ABLE TO FORM EARLY THIS AFTN. CLUSTER OF CELLS NEAR THE BLUE RIDGE AT 1745Z IS SLOWLY MOVING SEWD TOWARD THE FIELD. OUTFLOW FROM THESE CELLS COULD REACH THE FIELD 20-21Z BUT MIGHT KICK NEW ACTIVITY OFF BEFOREHAND. INCLUDED A TEMPO MVFR TSRA WHEN CHANCES LOOK GREATEST OVERALL PER MESO MODELS AND THE TIMING OF A WEAK SHORTWAVE PASSING THRU. BRISK GUSTS POSSIBLE WITH ANY TSRA. SOME CONVECTIVE DEBRIS FORMING A VFR CIG MAY LINGER OVERNIGHT IF TSRA CLUSTERS FORM UPSTREAM AS SUGGESTED BY GUIDANCE. MRNG RESTRICTIONS ARE NOT OUT OF THE QUESTION IF A TSRA DOES AFFECT THE FIELD THIS AFTN...ESP IF SAID DEBRIS DOES NOT FORM AND RADIATION IS MAXIMIZED UNDER LIGHT FLOW REGIME. DIURNAL CU WILL LIKELY FORM A BIT LOWER SATURDAY BUT STILL VFR. WINDS PREVAILING NWLY INTO SAT MRNG BUT THEN WILL BACK TO A NEAR CROSSWIND AS LEE TROUGH DEVELOPS. ELSEWHERE...CONVECTIVE CHANCES THIS AFTN ARE OVERALL NOT AS HIGH AS THE PAST COUPLE OF DAYS...BUT STILL WARRANTS A MENTION AT ALL SITES EXCEPT KAND. BEST CHANCES ARE ACTUALLY EAST OF THE BLUE RIDGE IN THE VICINITY OF A SMALL SHORTWAVE THAT WILL MOVE SEWD ACRS THE PIEDMONT THIS AFTN. GUSTY WINDS OF 20-25 KT AND BRIEF MVFR VSBY COULD OCCUR WITH ANY TSRA. EXCEPT IN THE VCNTY OF TSRA...NW TO W WINDS WILL PREVAIL THOUGH SOME VARIABILITY IS LIKELY GIVEN THE WEAK FLOW. MTN VALLEY FOG LIKELY AGAIN TONIGHT AND RAINFALL THIS AFTN WILL ENHANCE THE FOG POTENTIAL AS USUAL. NW TO WNW WINDS PREVAIL SAT WITH LEE TROUGH TO THE E. OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED INTO THE WEEKEND...WITH THE GREATEST COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF RECENT RAINFALL. CONFIDENCE TABLE... 20-02Z 02-08Z 08-14Z 14-20Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 95% HIGH 100% HIGH 84% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...STAARMANN NEAR TERM...SBK/WIMBERLEY SHORT TERM...JDL LONG TERM...JPT AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
243 PM EDT FRI JUN 20 2014 .SYNOPSIS... AN UPPER RIDGE WILL CONTINUE TO BREAK DOWN THROUGH THIS EVENING RESULTING IN WEAKENING HIGH PRESSURE CURRENTLY IN PLACE OVER THE AREA. THIS SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK. A TYPICAL WARM SUMMERLIKE PATTERN WILL CONTINUE THROUGH NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 200 PM EDT...CELLS NOW LINING UP ALONG THE BLUE RIDGE AS A WEAK RIPPLE ROUNDS THE RIDGE OVER THE LOWER MISSISSIPPI VALLEY AND MOVES SEWD ACRS THE AREA. HRRR SEEMS TO HAVE PICKED UP ON THIS ACTIVITY AND ALLOWS IT TO PROPAGATE SEWD SLIGHTLY BEFORE DISSIPATING...POSSIBLY DUE TO DOWNSLOPING BY THE NW FLOW ABOVE THE BOUNDARY LAYER. THE NCEP HIRES WINDOW /NMM/ SUGGESTS THE SAME...BUT DEVELOPS A NEW ROUND OF CONVECTION IN THE MTNS BEHIND IT WHICH FILLS IN THE SAME AREA. DEWPOINTS HAVE MIXED OUT SLIGHTLY AS EXPECTED...BUT NOT ENOUGH TO KEEP SBCAPE FROM RISING TO 2000 J OR MORE PER SPC MESOANALYSIS. NO SEVERE REPORTS HAVE YET BEEN RECEIVED BUT A FEW STORMS HAVE MET WARNING CRITERIA. I AM NO LONGER CONFIDENT IN OUR EARLIER EXPECTATIONS THAT WE WOULD NOT GET UNSTABLE ENOUGH FOR LARGE HAIL TO BE MUCH OF A CONCERN...BUT PROFILES REMAIN DRY ENOUGH FOR DCAPES OF 700-1000 J SUPPORTING A MICROBURST THREAT. CHC RANGE POPS HAVE BEEN MAINTAINED ACRS MOST OF THE AREA...BUT NOW THE GREATEST CHANCE APPEARS TO BE DOWNSTREAM OF THE CURRENT ACTIVITY. SOME MODELS INCLUDING THE NAM TRY TO DEVELOP ANOTHER ROUND OF CONVECTION AFTER SUNSET...BUT PROFILES HAVE ENOUGH CIN THAT I THINK THIS IS UNLIKELY IN THE PRESENCE OF SUCH WEAK FORCING. POPS DIMINISH EAST OF THE MTNS BY LATE EVENING. MAIN FORECAST CHALLENGE FOR THE OVERNIGHT IS WHETHER ANY ACTIVITY WILL MOVE INTO OUR AREA FROM THE WEST...AS SUGGESTED BY SOME OF THE MESO GUIDANCE AND THE 12Z NAM. THE NAM SHOWS AN MCV DEVELOPING OVER THE OHIO VALLEY LATE THIS AFTN AND PROGRESSING SEWD ACRS KY/TN...THE ORIGINAL CONVECTION DYING BUT THE MCV KICKING OFF NEW DEVELOPMENT ON THE WEST SLOPES OF THE MTNS WHICH THEN MOVES INTO NW NC AROUND DAYBREAK. SO FAR THE NAM DEPICTION OF THE ORIGINATING CONVECTION SEEMS OVERDONE...SO WILL ONLY GIVE THIS SMALL WEIGHT IN THE FCST. CLOUD COVER PROGGED BY THE MODELS APPEARS MAINLY TO BE CONVECTIVE DEBRIS AND IT IS A BIT HARDER TO HEDGE ON THAT. THE NAM SUGGESTS DEEP RH WILL BE HIGHER ON SATURDAY...PROBABLY SINCE IT EXPECTS DEBRIS TO COME IN DURING THE MORNING. GFS PROFILES REALLY DO NOT LOOK TOO MUCH DIFFERENT FROM TODAY...THOUGH SBCAPE IS STILL LOWER DUE TO SLIGHTLY WEAKER LAPSE RATES. THE DIFFERENCE IS NOT ONLY IMPORTANT FOR THE POTENTIALLY SIGNIFICANT REDUCTION IN INSTABILITY DUE TO CLOUDIER SKIES...BUT FOR A REDUCTION IN DCAPE AND MITIGATED SEVERE RISK. SPC FEATURES A 5 PCT AREA JUST TO OUR EAST WHERE WEAK SHORTWAVE /THE POTENTIAL MCV/ WILL PASS OVER DURING PEAK HEATING. IT DOES APPEAR THE BEST PRECIP CHANCES OVERALL WILL BE DURING THE MORNING IN THE NORTHERN FA AND THEN OVER THE I-77 CORRIDOR DURING THE AFTN WHERE THE BEST BUOYANCY IS SUGGESTED. TEMPS TONIGHT AND TOMORROW WILL REMAIN A CATEGORY OR SO ABOVE CLIMO. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 200 PM FRIDAY...HEIGHTS WILL GRADUALLY FALL THROUGH EARLY NEXT WEEK...AS UPPER HIGH CONTINUES TO WEAKEN AND RETROGRADE TOWARDS THE WESTERN GULF OF MEXICO. THIS WILL ALSO ALLOW WEAK FRONTAL ZONE TO BACK DOOR ITS WAY THROUGH THE AREA BY SUNDAY...POSSIBLY INTRODUCING SLIGHTLY COOLER AND DRIER AIR. THIS IS NOT EXPECTED TO ELIMINATE INSTABILITY ENOUGH TO HALT DIURNAL CONVECTION...BUT COVERAGE OF SUNDAY AFTERNOON/EVENING CONVECTION IS EXPECTED TO BE MORE TYPICAL OF WHAT ONE WOULD EXPECT THIS TIME OF YEAR (30-40 POPS MTNS...20/30 PIEDMONT). BY MONDAY... SHORT TERM MODELS DEPICT ESTABLISHMENT OF AN E/SE FLOW IN ASSOCIATION WITH A WEAK INVERTED RIDGE ALONG THE EASTERN SEABOARD. THIS UPSLOPE FLOW COULD SUPPORT A BIT MORE IN THE WAY OF DIURNAL CONVECTION BY MONDAY AFTERNOON...SO POPS RETURN TO ABOVE CLIMO BY THIS TIME. WEAK SHEAR WITH HALFWAY DECENT STEERING FLOW SHOULD PRECLUDE ANYTHING MORE THAN A TYPICAL EARLY SUMMER PULSE SEVERE THREAT OR FLASH FLOODING THREAT SUNDAY. HOWEVER...HEAVY RAINFALL MAY BECOME AN ISSUE MONDAY...AS UPPER FLOW WEAKENS ABOVE THE LOW LEVEL SOUTHEAST FLOW...POSSIBLY FAVORING ANCHORING OF CELLS ACROSS PORTIONS OF THE HIGH TERRAIN. TEMPS ARE EXPECTED TO RETURN TO NEAR CLIMO BY MONDAY IN THE RELATIVELY COOL E/SE FLOW REGIME. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 130 PM EDT FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON TUESDAY WITH WEAK UPPER RIDGING OVER THE SE CONUS AND A LOW AMPLITUDE UPPER TROF DIGGING DOWN OVER OVER THE DAKOTAS AND MINNESOTA. OVER THE NEXT FEW DAYS...THE TROF SLOWLY PROPAGATES EASTWARD...YET IT DOES NOT APPEAR TO MAKE MUCH HEADWAY SOUTHWARD. THE LONG RANGE MODELS HAVE BEEN DIFFERING A FAIR AMOUNT WRT THE AMPLIFICATION OF THIS TROF...BUT ITS LOOKING LIKE THEY ARE LEANING MORE TOWARDS STRONGER RIDGING OVER OUR FCST AREA THRU DAY 7. THIS PATTERN LEAVES OUR AREA UNDER GENERALLY WEAK WEST TO SWLY STEERING FLOW THRU THE PERIOD. AT THE SFC...THE REGION WILL BE UNDER THE INFLUENCE OF THE BERMUDA HIGH FOR MOST OF THE PERIOD WITH A COLD FRONT APPROACHING THE CAROLINAS BY EARLY WED AND WASHING OUT AS IT MOVES OVER THE CWFA. IN ITS WAKE...WEAK CANADIAN HIGH PRESSURE TRIES TO PUSH SOUTHWARD FROM NEW ENGLAND BUT ITS PROGRESS IS SUPPRESSED BY THE BERMUDA HIGH. WITH THE COMBINATION OF SLY MOIST FLOW...A WEAKLY SHEARED ENVIRONMENT AND MODERATE DIURNAL BUOYANCY...WE STILL HAVE A SOLID CHANCE OF PULSE TYPE CONVECTION ACROSS MUCH OF THE REGION EACH DAY...FAVORING IN THE MTN ZONES OVERALL. TEMPERATURES SHOULD REMAIN FAIRLY STEADY WITH VALUES NEAR NORMAL OR POSSIBLE A FEW DEGREES WARMER. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... AT KCLT...SOME QUESTION WHETHER TSRA WILL BE ABLE TO FORM EARLY THIS AFTN. CLUSTER OF CELLS NEAR THE BLUE RIDGE AT 1745Z IS SLOWLY MOVING SEWD TOWARD THE FIELD. OUTFLOW FROM THESE CELLS COULD REACH THE FIELD 20-21Z BUT MIGHT KICK NEW ACTIVITY OFF BEFOREHAND. INCLUDED A TEMPO MVFR TSRA WHEN CHANCES LOOK GREATEST OVERALL PER MESO MODELS AND THE TIMING OF A WEAK SHORTWAVE PASSING THRU. BRISK GUSTS POSSIBLE WITH ANY TSRA. SOME CONVECTIVE DEBRIS FORMING A VFR CIG MAY LINGER OVERNIGHT IF TSRA CLUSTERS FORM UPSTREAM AS SUGGESTED BY GUIDANCE. MRNG RESTRICTIONS ARE NOT OUT OF THE QUESTION IF A TSRA DOES AFFECT THE FIELD THIS AFTN...ESP IF SAID DEBRIS DOES NOT FORM AND RADIATION IS MAXIMIZED UNDER LIGHT FLOW REGIME. DIURNAL CU WILL LIKELY FORM A BIT LOWER SATURDAY BUT STILL VFR. WINDS PREVAILING NWLY INTO SAT MRNG BUT THEN WILL BACK TO A NEAR CROSSWIND AS LEE TROUGH DEVELOPS. ELSEWHERE...CONVECTIVE CHANCES THIS AFTN ARE OVERALL NOT AS HIGH AS THE PAST COUPLE OF DAYS...BUT STILL WARRANTS A MENTION AT ALL SITES EXCEPT KAND. BEST CHANCES ARE ACTUALLY EAST OF THE BLUE RIDGE IN THE VICINITY OF A SMALL SHORTWAVE THAT WILL MOVE SEWD ACRS THE PIEDMONT THIS AFTN. GUSTY WINDS OF 20-25 KT AND BRIEF MVFR VSBY COULD OCCUR WITH ANY TSRA. EXCEPT IN THE VCNTY OF TSRA...NW TO W WINDS WILL PREVAIL THOUGH SOME VARIABILITY IS LIKELY GIVEN THE WEAK FLOW. MTN VALLEY FOG LIKELY AGAIN TONIGHT AND RAINFALL THIS AFTN WILL ENHANCE THE FOG POTENTIAL AS USUAL. NW TO WNW WINDS PREVAIL SAT WITH LEE TROUGH TO THE E. OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED INTO THE WEEKEND...WITH THE GREATEST COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF RECENT RAINFALL. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 88% HIGH 87% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...STAARMANN NEAR TERM...WIMBERLEY SHORT TERM...JDL LONG TERM...JPT AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
213 PM EDT FRI JUN 20 2014 .SYNOPSIS... AN UPPER RIDGE WILL CONTINUE TO BREAK DOWN THROUGH THIS EVENING RESULTING IN WEAKENING HIGH PRESSURE CURRENTLY IN PLACE OVER THE AREA. THIS SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK. A TYPICAL WARM SUMMERLIKE PATTERN WILL CONTINUE THROUGH NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 200 PM EDT...CELLS NOW LINING UP ALONG THE BLUE RIDGE AS A WEAK RIPPLE ROUNDS THE RIDGE OVER THE LOWER MISSISSIPPI VALLEY AND MOVES SEWD ACRS THE AREA. HRRR SEEMS TO HAVE PICKED UP ON THIS ACTIVITY AND ALLOWS IT TO PROPAGATE SEWD SLIGHTLY BEFORE DISSIPATING...POSSIBLY DUE TO DOWNSLOPING BY THE NW FLOW ABOVE THE BOUNDARY LAYER. THE NCEP HIRES WINDOW /NMM/ SUGGESTS THE SAME...BUT DEVELOPS A NEW ROUND OF CONVECTION IN THE MTNS BEHIND IT WHICH FILLS IN THE SAME AREA. DEWPOINTS HAVE MIXED OUT SLIGHTLY AS EXPECTED...BUT NOT ENOUGH TO KEEP SBCAPE FROM RISING TO 2000 J OR MORE PER SPC MESOANALYSIS. NO SEVERE REPORTS HAVE YET BEEN RECEIVED BUT A FEW STORMS HAVE MET WARNING CRITERIA. I AM NO LONGER CONFIDENT IN OUR EARLIER EXPECTATIONS THAT WE WOULD NOT GET UNSTABLE ENOUGH FOR LARGE HAIL TO BE MUCH OF A CONCERN...BUT PROFILES REMAIN DRY ENOUGH FOR DCAPES OF 700-1000 J SUPPORTING A MICROBURST THREAT. CHC RANGE POPS HAVE BEEN MAINTAINED ACRS MOST OF THE AREA...BUT NOW THE GREATEST CHANCE APPEARS TO BE DOWNSTREAM OF THE CURRENT ACTIVITY. SOME MODELS INCLUDING THE NAM TRY TO DEVELOP ANOTHER ROUND OF CONVECTION AFTER SUNSET...BUT PROFILES HAVE ENOUGH CIN THAT I THINK THIS IS UNLIKELY IN THE PRESENCE OF SUCH WEAK FORCING. POPS DIMINISH EAST OF THE MTNS BY LATE EVENING. MAIN FORECAST CHALLENGE FOR THE OVERNIGHT IS WHETHER ANY ACTIVITY WILL MOVE INTO OUR AREA FROM THE WEST...AS SUGGESTED BY SOME OF THE MESO GUIDANCE AND THE 12Z NAM. THE NAM SHOWS AN MCV DEVELOPING OVER THE OHIO VALLEY LATE THIS AFTN AND PROGRESSING SEWD ACRS KY/TN...THE ORIGINAL CONVECTION DYING BUT THE MCV KICKING OFF NEW DEVELOPMENT ON THE WEST SLOPES OF THE MTNS WHICH THEN MOVES INTO NW NC AROUND DAYBREAK. SO FAR THE NAM DEPICTION OF THE ORIGINATING CONVECTION SEEMS OVERDONE...SO WILL ONLY GIVE THIS SMALL WEIGHT IN THE FCST. CLOUD COVER PROGGED BY THE MODELS APPEARS MAINLY TO BE CONVECTIVE DEBRIS AND IT IS A BIT HARDER TO HEDGE ON THAT. MORE DETAILS ON THE NEAR TERM TO COME SHORTLY. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 230 AM FRIDAY...MODELS CONTINUE TO INDICATE THAT H5 HEIGHTS WILL SLOWLY FALL ACROSS THE REGION SAT/SUN AS AN UPPER H5 HIGH RETROGRADES TOWARD THE SOUTH CENTRAL STATES AND AN UPPER TROUGH ROTATES OFF THE NE COAST. A SERIES OF UPPER IMPULSES WILL TRIGGER MCS/MCC OVER THE OHIO VALLEY FRI NIGHT AND PROPAGATE TOWARD THE NORTHERN NC PIEDMONT THRU EARLY SAT. HOWEVER...WITH THE LOSS OF HEATING/CAPE OVERNIGHT...THIS SYSTEM SHOULD WEAKEN CONSIDERABLY AS IT PASSES JUST TO OUR NORTH. HENCE...HAVE INHERITED LOW END CHANCE POPS MAINLY IN THE NORTHERN ZONES SAT MORNING. FOR SAT AFTERNOON...A BACK DOOR FRONTAL BOUNDARY WILL PUSH SOUTH...WITH SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE FRONT MAINLY IN THE NC PIEDMONT ZONES. THE NAM/GFS KEEPS THE CONDITIONS RELATIVELY DRY IN THE MTN/UPSTATE SC GIVEN MUCH DRIER PROFILE IN PREDOMINANT N/NW FLOW ALOFT. WITH THE HELP OF DOWNSLOPING WINDS...TEMPERATURES WILL BE AROUND 3-5 DEGREES ABOVE NORMAL OVER THE PIEDMONT WITH NEAR NORMAL IN THE MTNS. SUN...HIGH PRESSURE CENTERED OVER THE NE WILL NOSE DOWN INTO THE REGION...WITH ANOTHER ROUND OF MCS/MCC DEVELOPING OVER IN THE VICINITY OF KY/OHIO VALLEY...PROPAGATING SOUTHWARD TOWARD THE SOUTHERN APPALACHIANS SUN AFTERNOON. THIS FEATURE WILL REACH THE TN BORDERLINE AROUND 21Z SUN PER LATEST NAM AND WEAKENS CONSIDERABLY (THE NAM TOTALLY DRIES OUT) AS IT MOVES ACROSS EAST OF THE MTNS. THIS IS DUE TO THE PREVAILING N/NW DOWNSLOPE WINDS YIELDING MUCH DRIER PROFILE/STABLE ENVIRONMENT OVER THE PIEDMONT. HENCE...POPS REMAIN IN THE SLIGHT CHANCE/LOW CHANCE RANGE ACROSS MUCH OF THE REGION...WITH BETTER CHANCE IN THE MTN ZONES. TEMPERATURES WILL COOL DOWN BY 2-3 DEGREES ON SUN. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 130 PM EDT FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON TUESDAY WITH WEAK UPPER RIDGING OVER THE SE CONUS AND A LOW AMPLITUDE UPPER TROF DIGGING DOWN OVER OVER THE DAKOTAS AND MINNESOTA. OVER THE NEXT FEW DAYS...THE TROF SLOWLY PROPAGATES EASTWARD...YET IT DOES NOT APPEAR TO MAKE MUCH HEADWAY SOUTHWARD. THE LONG RANGE MODELS HAVE BEEN DIFFERING A FAIR AMOUNT WRT THE AMPLIFICATION OF THIS TROF...BUT ITS LOOKING LIKE THEY ARE LEANING MORE TOWARDS STRONGER RIDGING OVER OUR FCST AREA THRU DAY 7. THIS PATTERN LEAVES OUR AREA UNDER GENERALLY WEAK WEST TO SWLY STEERING FLOW THRU THE PERIOD. AT THE SFC...THE REGION WILL BE UNDER THE INFLUENCE OF THE BERMUDA HIGH FOR MOST OF THE PERIOD WITH A COLD FRONT APPROACHING THE CAROLINAS BY EARLY WED AND WASHING OUT AS IT MOVES OVER THE CWFA. IN ITS WAKE...WEAK CANADIAN HIGH PRESSURE TRIES TO PUSH SOUTHWARD FROM NEW ENGLAND BUT ITS PROGRESS IS SUPPRESSED BY THE BERMUDA HIGH. WITH THE COMBINATION OF SLY MOIST FLOW...A WEAKLY SHEARED ENVIRONMENT AND MODERATE DIURNAL BUOYANCY...WE STILL HAVE A SOLID CHANCE OF PULSE TYPE CONVECTION ACROSS MUCH OF THE REGION EACH DAY...FAVORING IN THE MTN ZONES OVERALL. TEMPERATURES SHOULD REMAIN FAIRLY STEADY WITH VALUES NEAR NORMAL OR POSSIBLE A FEW DEGREES WARMER. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AT KCLT...SOME QUESTION WHETHER TSRA WILL BE ABLE TO FORM EARLY THIS AFTN. CLUSTER OF CELLS NEAR THE BLUE RIDGE AT 1745Z IS SLOWLY MOVING SEWD TOWARD THE FIELD. OUTFLOW FROM THESE CELLS COULD REACH THE FIELD 20-21Z BUT MIGHT KICK NEW ACTIVITY OFF BEFOREHAND. INCLUDED A TEMPO MVFR TSRA WHEN CHANCES LOOK GREATEST OVERALL PER MESO MODELS AND THE TIMING OF A WEAK SHORTWAVE PASSING THRU. BRISK GUSTS POSSIBLE WITH ANY TSRA. SOME CONVECTIVE DEBRIS FORMING A VFR CIG MAY LINGER OVERNIGHT IF TSRA CLUSTERS FORM UPSTREAM AS SUGGESTED BY GUIDANCE. MRNG RESTRICTIONS ARE NOT OUT OF THE QUESTION IF A TSRA DOES AFFECT THE FIELD THIS AFTN...ESP IF SAID DEBRIS DOES NOT FORM AND RADIATION IS MAXIMIZED UNDER LIGHT FLOW REGIME. DIURNAL CU WILL LIKELY FORM A BIT LOWER SATURDAY BUT STILL VFR. WINDS PREVAILING NWLY INTO SAT MRNG BUT THEN WILL BACK TO A NEAR CROSSWIND AS LEE TROUGH DEVELOPS. ELSEWHERE...CONVECTIVE CHANCES THIS AFTN ARE OVERALL NOT AS HIGH AS THE PAST COUPLE OF DAYS...BUT STILL WARRANTS A MENTION AT ALL SITES EXCEPT KAND. BEST CHANCES ARE ACTUALLY EAST OF THE BLUE RIDGE IN THE VICINITY OF A SMALL SHORTWAVE THAT WILL MOVE SEWD ACRS THE PIEDMONT THIS AFTN. GUSTY WINDS OF 20-25 KT AND BRIEF MVFR VSBY COULD OCCUR WITH ANY TSRA. EXCEPT IN THE VCNTY OF TSRA...NW TO W WINDS WILL PREVAIL THOUGH SOME VARIABILITY IS LIKELY GIVEN THE WEAK FLOW. MTN VALLEY FOG LIKELY AGAIN TONIGHT AND RAINFALL THIS AFTN WILL ENHANCE THE FOG POTENTIAL AS USUAL. NW TO WNW WINDS PREVAIL SAT WITH LEE TROUGH TO THE E. OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED INTO THE WEEKEND...WITH THE GREATEST COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF RECENT RAINFALL. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 88% HIGH 87% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...STAARMANN NEAR TERM...WIMBERLEY SHORT TERM...JOH LONG TERM...JPT AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
252 PM EDT FRI JUN 20 2014 .SHORT TERM...(TONIGHT THROUGH SUNDAY)...AIRMASS WAS VERY UNSTABLE ACROSS PLATEAU COUNTIES NE INTO ERN KY AND SW VA THIS AFTERNOON. COVERAGE AND INTENSITY OF THUNDERSTORMS CONTINUES TO INCREASE WITH MOVEMENT E OR SE AT AROUND 20 MPH. ALL OF THIS ACTIVIVTY IS POISED TO SWEEP ACROSS OUR FORECAST AREA THIS EVENING...MUCH IN LINE WITH RAP MODEL OVER THE NEXT FEW HOURS...WITH NAM SHOWING A BIT MORE COVERAGE THAN RAP OR HRR. THINK NAM MAY BE OVERDOING CONVECTION OVER SE TN AND SW NC...SO STUCK WITH 30 TO 40 PERCENT POPS FOR THOSE AREAS. STORMS COULD BRIEFLY INTENSIFY TO MARGINALLY SEVERE WITH STRONG WINDS AND LOCALLY HEAVY RAINS. GFS MOS MINS WERE CLOSE TO PERSISTENCE AND GENERALLY FOLLOWED. BETTER COVERAGE OF SHOWERS AND STORMS ON SATURDAY WILL BE EARLY... FOLLOWED BY A DECREASING TREND IN POPS FOR SATURDAY NIGHT AND SUNDAY. SHOULD BE DRY AFTER SUNSET SATURDAY THROUGH SUNDAY MORNING WITH AREAS OF FOG LIKELY AGAIN. DROPPED POPS EARLIER IN GRIDS FOR SATURDAY NIGHT AND LIMITED POPS FOR SUNDAY TO THE AFTERNOON HOURS. LOW LEVEL FLOW BECOMES LIGHT NORTHERLY SATURDAY NIGHT SO A TAD COOLER BUT STILL AROUND SEASONAL NORMS. FAVORED A BLEND OF SIMILAR MOS MAXES EACH DAY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)...ATMOSPHERE BECOMES A LITTLE MORE CONDUCIVE TO CONVECTION AROUND THE TUESDAY THROUGH THURSDAY PERIOD AS A LONG WAVE TROUGH BUILDS INTO THE EASTERN U.S. A COOL FRONTAL BOUNDARY WILL BUILD INTO THE REGION DURING THIS TIME FRAME ADDING A BIT OF A FOCUS FOR STORM DEVELOPMENT IN THE WARM AND HUMID AIRMASS WHICH WILL RESIDE OVER THE MID SOUTH. STAYED VERY CLOSE TO SUGGESTED MIN TEMP MOS WHILE ADJUSTING MAX TEMPS ABOUT A COUPLE OF DEGREES BELOW MAX TEMPERATURE GUIDANCE. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 70 91 68 92 / 30 30 20 20 KNOXVILLE MCGHEE TYSON AIRPORT, TN 68 88 66 89 / 50 30 20 20 OAK RIDGE, TN 70 88 65 89 / 50 30 20 20 TRI CITIES AIRPORT, TN 64 84 60 86 / 60 40 20 20 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TG
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1247 PM CDT FRI JUN 20 2014 .AVIATION... /18Z TAFS/ CONCERNS...A FEW ISOLATED SHOWERS OR POSSIBLY THUNDERSTORMS AROUND KACT THIS AFTERNOON. VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD WITH BROKEN CIGS MAINLY DUE TO LOW LEVEL CUMULUS BETWEEN 4-6 KFT AND/OR DENSE HIGH CLOUD COVER. SOME ADDITIONAL SCATTERED CU AROUND 2000-2500 FEET WILL OCCUR IN THE WACO AREA TOMORROW MORNING...AND COULD POSSIBLY RESULT IN BKN SKIES FOR BRIEF PERIODS. THE WINDS WILL REMAIN GENERALLY LESS THAN 10 KTS AND WILL VARY BETWEEN 150-220 DEGREES WITH SOUTHEAST WINDS MORE PREVALENT IN THE EVENING HOURS AND SOUTHWEST WINDS MORE PREVALENT IN THE MORNING HOURS. A FEW SHOWERS ARE POSSIBLE AROUND THE KACT AREA THIS AFTERNOON FROM 21-01Z. IT IS POSSIBLE THAT A THUNDERSTORM OR TWO COULD ALSO OCCUR WITHIN A 10SM RADIUS OF THE AIRPORT BUT WILL CARRY VCSH FOR NOW. 82/JLD && .PREV DISCUSSION... /ISSUED 312 AM CDT FRI JUN 20 2014/ UPPER LOW HAS MOVED TO SOUTHEASTERN MANITOBA...AND SHOULD START PINWHEELING NORTH DURING THE DAY. RIDGE IS CENTERED OVER SOUTHERN MISSISSIPPI VALLEY AND WILL SLOWLY SLIDE SOUTHWEST OVER NEXT COUPLE OF DAYS. PWATS ARE ON THE WAY DOWN...FROM NEAR 2 INCHES YESTERDAY TO ABOUT AN INCH AND A HALF TODAY. GUIDANCE IS STRUGGLING WITH THE FEATURES THAT WILL DEFINE TODAY/S WEATHER...FROM THE CURRENT CONVECTION IN SOUTHERN OKLAHOMA TO SEA BREEZE TYPE SHOWERS MOVING IN FROM THE COAST. AS I WRITE THIS...THE OKLAHOMA CONVECTION IS WEAKENING AND MAY BE GONE BY 7 AM...BUT WILL KEEP A SMALL AREA OF ISOLATED THUNDER NEAR THE RED RIVER THIS MORNING. HAVE ALSO ADDED ISOLATED THUNDER FOR THIS AFTERNOON IN SOUTH AND SOUTHEAST ZONES AS HRRR AND WRF ARW BOTH HINT AT SOME SEA BREEZE CONVECTION MAKING IT THAT FAR NORTH. ATMOSPHERE WILL CONTINUE TO DRY AND HAVE LEFT SATURDAY AND SUNDAY PRECIP FREE AS THE HIGH BUILDS CLOSER TO NORTH TX. BY MONDAY...WITH HIGH LOCATED IN MEXICO...A SERIES OF TROUGHS WILL MOVE ACROSS THE SOUTHERN PLAINS AND HAVE THUS CONTINUED WITH THE LOW POP CHANCES IN THE NORTH MONDAY AND TUESDAY...AND AREA WIDE WEDNESDAY THROUGH SATURDAY MORNING. OF INTEREST IN THE EXTENDED...BY WEDNESDAY THE ECMWF BUILDS AN UPPER TROUGH ORIENTED NORTH/SOUTH ACROSS TEXAS AND KEEPS IT IN PLACE THROUGH 240 HOURS. IF THIS STATIONARY TROUGH WOULD MATERIALIZE (THE GFS BUILDS IN A RIDGE WEST AND PUSHES THE TROUGH EAST) IT WOULD GIVE US PERIODS OF MUCH NEEDED PRECIP OVER A NUMBER OF DAYS. ECMWF PUSHES PWATS ABOVE 2 INCHES AT DFW WEDNESDAY AFTERNOON...BUT THE GFS LOOKS MUCH DRIER. ONE ANALOG THAT COMES TO MIND WOULD BE THE WIDESPREAD RAIN/FLOODING THAT OCCURRED IN JUNE 2007 WITH A SIMILAR TROUGH. AGAIN...THERE IS NO CONSENSUS ON THIS OCCURRING SO WE CAN ONLY LOOK FOR MORE AGREEMENT IN FUTURE GUIDANCE 84. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 94 75 94 75 93 / 10 10 10 5 10 WACO, TX 91 72 93 73 92 / 10 5 10 5 10 PARIS, TX 92 72 92 72 91 / 10 10 10 5 10 DENTON, TX 93 73 93 74 93 / 10 10 10 5 10 MCKINNEY, TX 93 73 94 73 92 / 10 10 10 5 10 DALLAS, TX 93 76 94 75 93 / 10 5 10 5 10 TERRELL, TX 95 73 96 73 92 / 10 5 10 5 10 CORSICANA, TX 91 73 92 73 91 / 10 5 10 5 10 TEMPLE, TX 90 72 92 72 91 / 10 5 10 5 10 MINERAL WELLS, TX 91 72 92 73 92 / 10 5 10 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 82/58
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
116 PM EDT FRI JUN 20 2014 .SYNOPSIS... A WARM FRONT TRAILED FROM THE OHIO VALLEY DOWN ACROSS THE NEW RIVER VALLEY EARLY THIS AFTERNOON. THIS FRONT WILL LIFT NORTHEAST OF THE AREA THIS AFTERNOON. LOW PRESSURE WILL MOVE ALONG THIS FRONT...THROUGH THE OHIO VALLEY TONIGHT...THEN INTO VIRGINIA ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 115 PM EDT FRIDAY... A WARM FRONT REMAINS OVER THE FORECAST AREA AND WILL TRACK SLOWLY TO THE NORTHEAST THIS AFTERNOON. THIS WARM FRONT IS ORIENTED FROM NW TO SE AND IS PRODUCING SCATTERED SHOWERS ACROSS THE MOUNTAINS EARLY THIS AFTERNOON. THESE STORMS WILL CONTINUE TO TRACK NW TO SE THROUGH THE EARLY EVENING. AS THE WARM FRONT SHIFTS NORTH...SCATTERED SHOWER ACTIVITY WILL ALSO ADVANCE NORTH ACROSS THE ENTIRE AREA. MODEST CAPE VALUES ARE CURRENTLY BEING HELD DOWN BY CLOUD COVER. THIS CLOUD COVER WILL THIN OUT THROUGH THE DAY...WHICH WILL THEN INCREASE INSTABILITIES AS HEATING IS MAXIMIZED. VERTICAL SHEAR IS MARGINAL BUT INSTABILITIES WILL BE ENOUGH TO PRODUCE A FEW STRONG TO SEVERE MULTICELLAR STORMS THIS AFTERNOON AND INTO THIS EVENING. CONVECTION WILL FADE SOME WITH LOSE OF HEATING BUT ONLY TO GIVE WAY TO A MESOSCALE SYSTEM ENTERING THE AREA FROM THE OHIO VALLEY LATER TONIGHT. SPC HAS UPGRADED THE SOUTHERN OHIO VALLEY TO A SLIGHT RISK. EXPECT THIS SLIGHT RISK TO MOVE EASTWARD AS THE MCS CONTINUES TO STRENGTHEN AND SHOWS IT TRUE PATH. AS OF 400 AM EDT FRIDAY... WARM FRONT...MAINLY INDICATED AROUND 850 MB...ACROSS THE OHIO VALLEY WILL BRING SOME WARM AIR ADVECTION AND KEEP DEEPER MOISTURE IN THE AREA TODAY. AGAIN EXPECTING SCATTERED THUNDERSTORMS THIS AFTERNOON. SIMILAR TO THURSDAY...HIGH CLOUDS WILL CUT BACK ON HEATING IN THE MORNING AND THEREFORE THE AMOUNT OF INSTABILITY IN THE AFTERNOON. STILL ENOUGH CAPE...FORECAST TO BE AROUND 1500 J/KG...FOR A THREAT OF STRONGER THUNDERSTORMS BEFORE 00Z/8PM. HRRR BRINGS PRECIPITATION IN TO THE FORECAST AROUND 17Z/1PM. MODELS HAVE BEEN TRENDED COOLER WITH MAXIMUM TEMPERATURES FOR TODAY. HIGH WILL DEPEND ON HOW MUCH HIGH CLOUDS FROM THIS MORNING CAN ERODE BEFORE THUNDERSTORMS DEVELOP. SHORT WAVE OVER ILLINOIS AND INDIANA WILL MOVE SOUTHEAST...REACHING WESTERN PARTS OF THE FORECAST AREA JUST AFTER 00Z AND SLOWLY MOVING ACROSS THE COUNTY WARNING AREA OVERNIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION TONIGHT WITH HIGHEST PROBABILITY AFTER MIDNIGHT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... AS OF 320 AM EDT FRIDAY... LOW PRESSURE WILL TRACK SOUTHEAST FROM NORTHERN WEST VIRGINIA SATURDAY MORNING AND REACHES EASTERN VIRGINIA BY SATURDAY AFTERNOON. THE NAM...GFS AND ECMWF SUPPORT GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS SATURDAY AS DISTURBANCE TRACKS EASTWARD ALONG THE THETA-E BOUNDARY. INCREASED POPS FOR SATURDAY ESPECIALLY SATURDAY MORNING. SPC SWODY2 HAS PLACED THE SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL PLAINS WITH A SEE TEXT IN EASTERN CAROLINAS. WITH ADDITIONAL CLOUD COVER AND PRECIPITATION SATURDAY...LOWERED HIGH TEMPERATURES WITH READINGS FROM THE UPPER 70S IN THE MOUNTAINS TO UPPER 80S IN THE PIEDMONT. AFTER THE DISTURBANCE EXITS THE AREA SATURDAY EVENING...A SLIGHT COOLER AND DRY AIRMASS WILL TEMPORARY BUILD OVER THE REGION SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL RANGE FROM AROUND 60 DEGREES IN THE WEST TO THE MID 60S IN THE EAST. SFC HIGH PRESSURE PROGGED TO BE CENTERED EAST SOUTHEAST OF NEW ENGLAND ON SUNDAY...AND SLOWLY BUILDS SOUTHWARD. DECREASED POPS FOR SUNDAY AS A NORTHERLY FLOW AND LESS INSTABILITIES SHOULD LEAD TO LESS CONVECTION. WITH CAUTION...HELD ON TO SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE GFS WAS MORE ROBUST WITH CONVECTION COMPARED TO ECMWF AND NAM FOR SUNDAY. WENT WITH HIGH TEMPERATURES SUNDAY FROM THE UPPER 70S IN THE MOUNTAINS TO THE MID 80S IN THE PIEDMONT. SOUTHEASTERLY FLOW OVERNIGHT SUNDAY MAY KEEP A FEW SHOWERS ONGOING INTO EARLY MONDAY MORNING. THE BEST CHANCE FOR SHOWERS SUNDAY NIGHT WILL OCCUR ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS. LOWS SUNDAY NIGHT WILL GENERALLY BE IN THE 60S. LEANED TOWARDS HPCGUIDE FOR MONDAY WITH PULSE STORM AND THE PRIMARY FOCUS FOR CONVECTION ACROSS THE MOUNTAINS. TAPER OFF SCATTERED STORMS TO ISOLATED SHOWERS MONDAY NIGHT. && .LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... TUESDAY COULD BE A MIX OF CONVECTION FROM PULSE STORMS IN THE EARLY AFTERNOON TRANSITIONING TO PREFRONTAL CONVECTION IN THE EARLY EVENING THROUGH THE EARLY MORNING HOURS. ON WEDNESDAY...A COLD FRONT WILL SLIDE ACROSS THE REGION WITH THE BEST AREAL COVERAGE OF THE STRONGER STORMS BEING ACROSS THE PIEDMONT. THE COLD FRONT MAY WASHOUT OR STALL WITH THE DEW POINT FRONT HANGING BACK ACROSS THE OHIO VALLEY. UNDER HEATING...SCATTERED CONVECTION MAY FIRE AGAIN ACROSS THE AREA THURSDAY ESPECIALLY ALONG AND SOUTH OF THE VA/NC BORDER. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... AS OF 115 PM EDT FRIDAY... PATCHES MVFR CLOUDS WILL LIFT EARLY THIS AFTERNOON AS A WARM FRONT MOVES NORTH OF THE FORECAST AREA. ENOUGH HEATING AND DECENT INSTABILITY FOR SHOWERS AND THUNDERSTORMS TO DEVELOP THROUGH THE AFTERNOON. SLOW MOVING NW TO SE TRACKING STORMS EXPECTED AT BLF/LWB BETWEEN 19Z/2P-02Z/10. HIT AND MISS THUNDERSTORMS EXPECTED ACROSS THE AREA WHILE CONFIDENCE FOR A STORM TO BE IN THE VICINITY OF KROA/KBCB/KLYH/KDAN AT A GIVEN TIME IS VERY LOW. A STRONGER SHORT WAVE WILL REACH THE FORECAST AREA TONIGHT. HAVE KEPT CEILINGS VFR AT KROA/KBCB/KLYH AND KDAN WITH SHOWERS...MAINLY AFTER 05Z/1AM SATURDAY. MODERATE CONFIDENCE OF MVFR CEILINGS FOR KLWB/KBLF WITH A PROLONGED PERIOD OF SHOWERS AND EMBEDDED THUNDERSTORMS OVERNIGHT. EXTENDED AVIATION DISCUSSION... A WEAK FLOW PATTERN HOLDING OVER THE WEEKEND WILL KEEP THE STORM CHANCES EACH AFTERNOON THROUGH EARLY EVENING SAT/SUN BUT COVERAGE FOR NOW LOOKS A BIT LESS EACH DAY BEHIND THE PASSING IMPULSE FROM SATURDAY MORNING. DEEPER MOISTURE LOOKS TO RETURN NORTH BY EARLY NEXT WEEK WITH BETTER COVERAGE OF AFTERNOON/EVENING STORMS ON MONDAY. AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING... PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE AFTERNOON CONVECTION REDEVELOPS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/RCS SHORT TERM...KK LONG TERM...RCS AVIATION...RCS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
344 PM CDT FRI JUN 20 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 344 PM CDT FRI JUN 20 2014 AT 3 PM...TWO BOUNDARIES WERE LOCATED ACROSS THE FORECAST AREA. THE FIRST OF THESE TWO EXTENDS FROM NEW RICHMOND /KRNH/ TO LA CROSSE WISCONSIN. BOTH THE RAP AND LAPS DATA SHOW 150 TO 200 J/KG OF SURFACE TO 3 KM CAPE...STRONG LAYER ENHANCED STRETCHING POTENTIAL...STEEP 0-2 KM LAPSE RATES /GREATER THAN 9 C/KM /...AND WEAK TO MODERATE SURFACE RELATIVE VORTICITY. THIS WOULD BE SUPPORTIVE OF NON-SUPERCELL TORNADOES. THESE CONDITIONS CONTINUE THROUGH 21.02Z. HOWEVER AT THIS TIME...IT LOOKS LIKE THE CONVERGENCE WILL NOT BE GREAT ENOUGH FOR THEIR DEVELOPMENT. A SECOND BOUNDARY LOOKS TO BE EITHER A DRY LINE OR A DIFFERENTIAL HEATING BOUNDARY ACROSS CENTRAL WISCONSIN. THERE WAS A BRIEF SHOWER AT WAUSAU. JUST LIKE THE PREVIOUS BOUNDARY...THE CONVERGENCE IS NOT THAT STRONG ALONG THE BOUNDARY. WITH 2 TO 3K SURFACE BASED CAPES...WILL HAVE TO MONITOR THIS AREA FOR DEVELOPMENT. FURTHER NORTHWEST...A SHORT WAVE TROUGH WAS MOVING ACROSS NORTHERN MINNESOTA. THIS SYSTEM WAS MOVING THROUGH AN AREA OF 1K SURFACE CAPES. THIS HAS RESULTED IN THE DEVELOPMENT OF SHOWERS AND STORMS. WITH THE RAP SHOWING EFFECTIVE SHEAR GREATER THAN 40 KNOTS...AREAS NORTH OF INTERSTATE 94 WILL HAVE TO BE MONITORED FOR THE POTENTIAL OF SEVERE WEATHER. THERE IS A BOUNDARY NORTH OF PHILLIPS WISCONSIN. THIS COULD AID IN THE DEVELOPMENT OF A FEW TORNADOES. MEANWHILE FURTHER SOUTH...THE THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. THIS MAY AFFECT CLARK AND TAYLOR COUNTIES LATE THIS AFTERNOON AND EVENING...BUT THIS IS HIGHLY DEPENDENT ON WHETHER STORMS CAN EVEN DEVELOP. MANY OF THE MESO MODELS SUGGEST THAT THIS WILL NOT BE THE CASE. FINALLY...AN AREA OF SHOWERS AND STORMS ARE DEVELOPING AHEAD OF A SHORT WAVE TROUGH MOVING OUT OF CENTRAL NEBRASKA. A FEW OF THESE STORMS HAVE ALREADY BECOME SEVERE. THE GFS...ECMWF...AND ARW SUGGEST THAT THESE SUPERCELLS WILL DEVELOP INTO A MESOSCALE CONVECTIVE COMPLEX WHICH WILL MOVE THROUGH OUR AREAS ALONG AND SOUTH OF INTERSTATE 90 BETWEEN 21.06Z AND 21.15Z. AT THIS TIME...IT LOOKS LIKE THE 0-3 KM AND 0-6 KM SHEAR WILL BE TOO WEAK FOR ANY SEVERE WEATHER WITH THIS COMPLEX. ONE THING THAT WILL HAVE TO WATCHED IS THAT THE HOP WRF AND HRRR SUGGEST THAT THIS COMPLEX MAY DIVE SOUTHEAST TOWARD THE BETTER INSTABILITY ACROSS MISSOURI...SO WILL HAVE TO WATCH THIS CLOSELY LATE TONIGHT. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 344 PM CDT FRI JUN 20 2014 THIS PART OF THE FORECAST IS GREATLY COMPLICATED DUE TO ZONAL FLOW ALOFT. THE EXTENDED MODELS ARE SHOWING VARYING TIMES AND STRENGTHS OF SHORT WAVES EMBEDDED IN THIS FLOW. OVERALL...THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE FROM SUNDAY NIGHT THROUGH MONDAY AS A SHORT WAVE TROUGH MOVES THROUGH THE CENTRAL PLAINS AND MID MISSISSIPPI RIVER VALLEY...AND FROM TUESDAY THROUGH WEDNESDAY AS A CANADIAN COLD FRONT DROPS INTO THE AREA. THIS FRONT WILL LIKELY INCREASE THE SHEAR ACROSS THE AREA FOR THE POTENTIAL OF SEVERE WEATHER. HOWEVER THERE ARE UNCERTAINTIES ON HOW FAR SOUTH THIS FRONT WILL GET DUE TO THE ZONAL FLOW. AS A RESULT...STAYED CLOSE TO THE MODEL CONSENSUS FOR NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1241 PM CDT FRI JUN 20 2014 AS SKIES CLEAR EARLY THIS AFTERNOON...A 3-4KFT CU DECK WILL FORM BUT SHOULD STAY FEW-SCT. WINDS WILL GENERALLY BE OUT OF THE WEST AND REMAIN LIGHT AT 10KT OR LESS. THE MAIN QUESTION IS WITH WHETHER ANY RAIN WILL BE ABLE TO DEVELOP AND TRACK THROUGH OVERNIGHT. HAVE GONE THE OPTIMISTIC ROUTE AND LEFT CONDITIONS DRY OVERNIGHT...BUT WILL HAVE TO WATCH THE LATEST TRENDS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1241 PM CDT FRI JUN 20 2014 .UPDATE... ISSUED AT 1058 AM CDT FRI JUN 20 2014 ADDED A SLIGHT CHANCE FOR SHOWERS/STORMS ACROSS NORTH CENTRAL WISCONSIN FOR THIS AFTERNOON. THE PAST FEW RUNS OF THE HRRR HAVE INITIATED SOME WEAK CONVECTION IN EASTERN TO NORTH CENTRAL WISCONSIN ALONG A BOUNDARY THAT CURRENTLY RESIDES IN THAT AREA. 20.13Z RAP SOUNDINGS FROM NECEDAH SHOWS THAT THE ATMOSPHERE REMAINS CAPPED OFF...BUT ITS SURFACE DEW POINT MAY BE A TAD DRY COMPARED TO WHAT THE HRRR HAS. REGARDLESS...SAW ENOUGH TO WARRANT SOME SMALL CHANCES FOR SHOWERS/STORMS IN THIS AREA. OTHERWISE...THE CLOUD SHIELD WILL CLEAR FROM THE WEST TODAY AND PROVIDE A FAIRLY WARM DAY WITH TEMPERATURES CLIMBED UP INTO THE 80S. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 342 AM CDT FRI JUN 20 2014 THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TONIGHT THROUGH SUNDAY. LOCAL AND REGIONAL RADARS THIS MORNING SHOWING MOST OF THE SHOWERS THIS MORNING WERE OVER THE NORTHERN AND EASTERN SECTIONS OF WISCONSIN WITH JUST SOME WIDELY SCATTERED ACTIVITY OVER THE CENTRAL PART OF THE STATE. THESE SHOWERS WERE MOVING OFF TO THE NORTH/NORTHEAST AND THE 20.05Z HRRR SUGGESTS THESE SHOULD MOVE OUT OF THE FORECAST AREA BY 12Z. WILL MONITOR THE RADAR TRENDS BUT MAY HAVE TO START THE MORNING WITH A VERY SMALL RAIN CHANCE ACROSS THE FAR NORTHERN AND EASTERN PARTS OF THE FORECAST AREA WITH ANY REMAINING SHOWERS EXPECTED TO BE COMPLETELY OUT OF THE AREA BY MID MORNING. THE UPPER LEVEL LOW OVER SASKATCHEWAN WILL LIFT SLOWLY NORTHEAST THROUGH TONIGHT AND BECOME AN OPEN WAVE OVER SOUTHERN MANITOBA AND WESTERN ONTARIO ALLOWING THE FLOW OVER THE UPPER MIDWEST TO BECOME ZONAL. ONE SHORT WAVE TROUGH ROUNDING THE REMAINS OF THIS UPPER LEVEL LOW IS EXPECTED TO MOVE ACROSS NORTHERN MINNESOTA TONIGHT WITH ANOTHER WEAKER WAVE COMING OUT OF THE ROCKIES AND ACROSS NEBRASKA AND SOUTHERN IOWA. NOT A LOT OF PV ADVECTION WITH EITHER OF THESE WAVES...BUT ENOUGH WARM AIR ADVECTION SHOULD OCCUR TO PRODUCE 4 TO 6 UBAR/S OF UP GLIDE ON THE 305K ISENTROPIC SURFACE. THE MODELS ARE SPLIT ON HOW MUCH AND WHERE THE MOISTURE TRANSPORT WILL BE WITH THESE WAVES. THE 20.00Z NAM SUGGESTS WEAK TRANSPORT SHOULD OCCUR AHEAD OF THE NORTHERN WAVE INTO NORTHERN WISCONSIN AND MINNESOTA WHILE THE 20.00Z GFS AND ECMWF HAVE THE MOISTURE TRANSPORT AHEAD OF THE SOUTHERN WAVE INTO NEBRASKA WHERE THEY DEVELOP A CONVECTIVE COMPLEX. THE GFS THEN KEEPS THIS COMPLEX GENERALLY SOUTH OF THE AREA WHILE THE ECMWF BRINGS INTO THE THE AREA. THE 20.03Z SREF PROBABILITIES TEND TO FAVOR THE GFS SOLUTION WITH THE CONVECTIVE COMPLEX BUT ALSO HAVE SOME LOW PROBABILITIES ACROSS THE NORTH SIMILAR TO THE NAM. WITH SUCH WEAK FORCING SIGNALS AND DIFFERING MODEL SOLUTIONS...WILL JUST HAVE SOME LOW RAIN CHANCES ACROSS MOST THE AREA FOR THE OVERNIGHT HOURS. THE ZONAL FLOW CONTINUES INTO SATURDAY WITH ALL THE MODELS SHOWING ANOTHER WEAK WAVE COMING ACROSS THE NORTHERN ROCKIES INTO THE UPPER MIDWEST. THE GFS IS THE FARTHEST NORTH BRINGING THIS ACROSS MINNESOTA INTO IOWA WHILE THE NAM AND ECMWF TAKE IT ACROSS IOWA. THIS RESULTS IN BIG DIFFERENCES IN HOW MUCH AND WHERE THE RAIN COULD FALL. THE NAM AND ECMWF KEEP THE MAJORITY OF THE RAIN TO THE SOUTH OF THE AREA WHILE THE GFS WOULD INDICATE ALL OF THE FORECAST AREA WOULD HAVE A CHANCE FOR GETTING WET. AGAIN...THE SREF PROBABILITIES FAVOR THE NAM AND ECMWF SOLUTIONS SO PLAN TO SHOW 20 TO 30 PERCENT CHANCES THROUGH THE DAY WITH THESE HIGHEST ACROSS THE SOUTH. THE RAIN THAT DEVELOPS SATURDAY SHOULD CONTINUE ACROSS THE SOUTH INTO SATURDAY EVENING BEFORE STARTING TO MOVE OFF TO THE EAST SATURDAY NIGHT. A STRONGER SHORT WAVE TROUGH IS EXPECTED TO MOVE OUT OF THE ROCKIES AND START TO APPROACH THE AREA SUNDAY. THE PV ADVECTION IN THE 500-300 MB LAYER WILL STAY TO THE WEST OF THE AREA. THE ISENTROPIC UP GLIDE AHEAD OF THIS WAVE SHOULD MOVE INTO THE WESTERN SECTIONS OF IOWA AND MINNESOTA BY LATE IN THE DAY SUNDAY. IF THE MODELS REMAIN CONSISTENT WITH THESE SIGNALS...THE BEST RAIN CHANCES SHOULD BE CONFINED TO THE WESTERN SECTIONS OF THE FORECAST AREA AND THE EASTERN SECTIONS COULD BE DRY...BUT WITH THE GFS BEING QUICKER TO MOVE THIS SYSTEM IN...WILL SHOW A 30 TO 40 PERCENT CHANCE FROM EAST TO WEST. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 AM CDT FRI JUN 20 2014 THE MODEL DIFFERENCE CONTINUE INTO EARLY NEXT WEEK AS WELL. GENERAL CONSENSUS THAT THE SHORT WAVE TROUGH THAT COMES OUT SUNDAY WILL WEAKEN AS IT MOVES TOWARD MINNESOTA IN FAVOR OF ANOTHER WAVE COMING ACROSS NEBRASKA OR KANSAS. THE ECMWF THEN TAKES THIS WAVE NORTHEAST AND INTO THE GREAT LAKES REGION THROUGH MONDAY WHILE THE GFS AMPLIFIES THIS FORMING AN UPPER LEVEL LOW OVER THE UPPER MIDWEST MONDAY NIGHT WITH THE 20.00Z GEM DOING SOMETHING VERY SIMILAR. BOTH THE ECMWF AND GFS THEN SHOW WEAK RIDGING BUILDING OVER THE UPPER MIDWEST BY THE END OF PERIOD WITH THE ECMWF QUICKER TO DO THIS THAN THE GFS. BECAUSE OF THE DIFFERENCES BETWEEN THE MODELS...WILL HAVE SOME RAIN CHANCES THROUGH THE ENTIRE PERIOD WITH THE HIGHEST CHANCES MONDAY INTO MONDAY NIGHT WHEN THE FORCING FROM THE WAVE SHOULD BE THE STRONGEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1241 PM CDT FRI JUN 20 2014 AS SKIES CLEAR EARLY THIS AFTERNOON...A 3-4KFT CU DECK WILL FORM BUT SHOULD STAY FEW-SCT. WINDS WILL GENERALLY BE OUT OF THE WEST AND REMAIN LIGHT AT 10KT OR LESS. THE MAIN QUESTION IS WITH WHETHER ANY RAIN WILL BE ABLE TO DEVELOP AND TRACK THROUGH OVERNIGHT. HAVE GONE THE OPTIMISTIC ROUTE AND LEFT CONDITIONS DRY OVERNIGHT...BUT WILL HAVE TO WATCH THE LATEST TRENDS. && .HYDROLOGY... ISSUED AT 342 AM CDT FRI JUN 20 2014 WITH ALL THE RECENT RAINS...NUMEROUS RIVERS AND STREAMS HAVE FLOODING ALONG THEM RESULTING IN AREAL AND RIVER FLOOD WARNINGS. WITH A DRY DAY TODAY...SOME OF THE WATER MAY RECEDE ENOUGH TO ALLOW THE AREAL FLOOD WARNINGS TO BE DISCONTINUED OR MADE SMALLER IN SIZE. HOWEVER...MANY OF THE RIVERS WILL REMAIN ABOVE FLOOD STAGE INTO THE WEEKEND. WHILE ADDITIONAL RAINFALL IS IN THE FORECAST THROUGH THE WEEKEND...EXPECTED AMOUNTS AT THIS TIME SHOULD NOT BE ENOUGH TO AGGRAVATE EXISTING FLOODING PROBLEMS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...HALBACH SHORT TERM...04 LONG TERM...04 AVIATION...HALBACH HYDROLOGY...04