Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/22/14


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
340 PM MST SAT SEP 20 2014 .UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS. && .SYNOPSIS... LINGERING MOISTURE ACROSS THE REGION AND LOW PRESSURE APPROACHING FROM THE WEST WILL KEEP AT LEAST SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS FOR TODAY. DRIER AIR WILL GRADUALLY FILTER INTO THE REGION SUNDAY AND MONDAY FOR A DECLINE IN STORM CHANCES. SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE HIGHER MOUNTAINS OF SOUTH-CENTRAL ARIZONA DURING THE MIDDLE OF NEXT WEEK WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. AN APPROACHING PACIFIC WEATHER SYSTEM LATE NEXT WEEK WILL LEAD TO AN INCREASE IN STORM CHANCES. && .DISCUSSION... MODEL THETA-E GRADIENT ALIGNED WELL WITH THE FAVORABLE LOCATIONS OF HIGHER MOISTURE CONTENT AND GREATER INSTABILITY. THE RAP MLCAPE VALUES JUST OVER 1500 J/KG ALONG AN AXIS FROM NOGALES TO BULLHEAD CITY. WESTERN MARICOPA COUNTY...LA PAZ AND NORTHERN YUMA COUNTIES LOOK TO BE THE FAVORABLE AREAS FOR CONVECTION THIS AFTERNOON AND EVENING. CAN NOT RULE OUT ISOLATED STORMS SNEAKING IN TO NORTHERN PINAL COUNTY FROM SOUTH-CENTRAL ARIZONA...AS THE GREATER TUCSON AREA HAS BEEN INCREASING IN ACTIVITY LATE THIS MORNING. PRECIPITABLE WATER VALUES HOVERING AROUND 1.5 INCHES ACROSS THE LOWER DESERTS AND A VERY BROAD DIFLUENT MID-LAYER STRETCHING NORTH-NORTHWEST THROUGH THE GREAT BASIN ALLOWS FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON AND EVENING. MOISTURE AND DYNAMICS ARE IN PLACE AND THE POTENTIAL ENERGY IS THERE...NOW THE CHALLENGE WILL BE FOR A TRIGGER TO PUSH THE DEVELOPMENT NEEDED FOR THUNDERSTORM DEVELOPMENT. STORM CHANCES WILL BE ON THE DECLINE THROUGH MONDAY BEFORE COMING TO A QUIET HOLDING PATTERN THROUGH THE WEEK. MONSOON MOISTURE LOOKS TO HANG AROUND THIS WEEK BUT MAINLY ACROSS EASTERN ARIZONA. THE UPPER LEVEL DISTURBANCE IS PROGGED TO MOVE NORTH THROUGH THE GREAT BASIN BY MONDAY AND WILL ALLOW A WESTERLY FLOW TO SETTLE IN PLACE OVER THE SOUTHWEST DESERTS AS WELL AS A DRYING TREND. WILL KEEP SLIGHT CHANCE MENTION IN ZONE 24 FOR THE HIGHER TERRAIN LOCATIONS. TEMPERATURES WILL HAVE LITTLE DAY TO DAY CHANGE...REMAINING AT OR A FEW DEGREES ABOVE SEASONAL NORMAL WITH HIGH PRESSURE DOMINATING THE REGION THROUGH MID WEEK. THURSDAY THROUGH SATURDAY...ATTENTION THEN TURNS TO A POSSIBLE SEASONAL TRANSITION SYSTEM FOR LATE WEEK INTO NEXT WEEKEND. CONFIDENCE IS STILL NOT VERY HIGH ON THE SPECIFICS OF THE SYSTEM BUT THE 00Z OPERATIONAL MODELS HAVE COME IN CLOSER AGREEMENT THAT A DEEP PACIFIC TROUGH WILL SLIDE THROUGH CALIFORNIA ON FRIDAY AND POSSIBLY AS FAR SOUTH AS ARIZONA SOMETIME NEXT WEEKEND. WIDESPREAD SLIGHT CHANCE POPS ARE IN THE FORECAST FOR FRIDAY. EITHER WAY IT IS FAIRLY LIKELY THIS LOW WILL USER IN COOLER AND MUCH DRIER AIR...AND POTENTIALLY END OUR MONSOON SEASON. && .AVIATION... SOUTH-CENTRAL AND SOUTHWEST ARIZONA INCLUDING KPHX...KIWA...KSDL... ISOLATED TO WIDELY SCATTERED THUNDERSTORM ACTIVITY WILL PERSIST THIS AFTERNOON AND EVENING OVER SOUTH-CENTRAL AZ...A FEW STORMS COULD BRIEFLY IMPACT LOW DESERT TERMINALS WITH GUSTY OUTFLOWS UP TO 40 KT...AND REDUCED VISIBILITY DOWN TO 3SM IN BLDU. EXPECT SCT-BKN CLOUD DECKS AOA 7000FT TO PERSIST OVERNIGHT TIMES INTO SUNDAY MORNING. ONCE POTENTIAL FOR OUTFLOW BOUNDARIES DIMINISHES AFTER 04Z...WINDS WILL GENERALLY BE LIGHT...LESS THAN 10KT AND FAVOR THE EAST SOUTHEAST AT ALL TERMINALS. SOUTHEAST CALIFORNIA INCLUDING KIPL...AND KBLH... OTHER THAN A FEW CLOUDS GENERALLY AOA 10KFT...EXPECT MOSTLY CLEAR SKIES AND LIGHT WINDS OVERNIGHT THROUGH AT LEAST 18Z SUNDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... MOISTURE RETREAT DUE TO WESTERLY FLOW WILL KEEP STORM CHANCES MINIMAL THROUGH THURSDAY AND LIMITED TO THE HIGHER MOUNTAINS OF SOUTH-CENTRAL ARIZONA. MEANWHILE...TEMPERATURES NUDGE UPWARD A FEW DEGREES ABOVE NORMAL. HUMIDITIES ON THE LOWER DESERTS DROP BELOW 15 PERCENT THOUGH MAX HUMIDITIES REMAIN FAIR. NO STRONG WINDS ARE EXPECTED DURING THIS TIME FRAME. ON FRIDAY...A PACIFIC WEATHER SYSTEM WILL PULL MOISTURE NORTHWARD OVER THE REGION FOR A RETURN OF STORM CHANCES INTO NEXT WEEKEND...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY. IN ADDITION...COOLER TEMPERATURES AND BREEZY TO LOCALLY WINDY CONDITIONS CAN BE EXPECTED AS WELL. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...DEWEY AVIATION...MEYERS FIRE WEATHER...MEYERS/AJ
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
205 PM MST SAT SEP 20 2014 .SYNOPSIS... LINGERING MOISTURE ACROSS THE REGION AND LOW PRESSURE APPROACHING FROM THE WEST WILL KEEP AT LEAST SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS FOR TODAY. DRIER AIR WILL GRADUALLY FILTER INTO THE REGION SUNDAY AND MONDAY FOR A DECLINE IN STORM CHANCES. SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE HIGHER MOUNTAINS OF SOUTH-CENTRAL ARIZONA DURING THE MIDDLE OF NEXT WEEK WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. AN APPROACHING PACIFIC WEATHER SYSTEM LATE NEXT WEEK WILL LEAD TO AN INCREASE IN STORM CHANCES. && .DISCUSSION... MODEL THETA-E GRADIENT ALIGNED WELL WITH THE FAVORABLE LOCATIONS OF HIGHER MOISTURE CONTENT AND GREATER INSTABILITY. THE RAP MLCAPE VALUES JUST OVER 1500 J/KG ALONG AN AXIS FROM NOGALES TO BULLHEAD CITY. WESTERN MARICOPA COUNTY...LA PAZ AND NORTHERN YUMA COUNTIES LOOK TO BE THE FAVORABLE AREAS FOR CONVECTION THIS AFTERNOON AND EVENING. CAN NOT RULE OUT ISOLATED STORMS SNEAKING IN TO NORTHERN PINAL COUNTY FROM SOUTH-CENTRAL ARIZONA...AS THE GREATER TUCSON AREA HAS BEEN INCREASING IN ACTIVITY LATE THIS MORNING. PRECIPITABLE WATER VALUES HOVERING AROUND 1.5 INCHES ACROSS THE LOWER DESERTS AND A VERY BROAD DIFLUENT MID-LAYER STRETCHING NORTH-NORTHWEST THROUGH THE GREAT BASIN ALLOWS FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON AND EVENING. MOISTURE AND DYNAMICS ARE IN PLACE AND THE POTENTIAL ENERGY IS THERE...NOW THE CHALLENGE WILL BE FOR A TRIGGER TO PUSH THE DEVELOPMENT NEEDED FOR THUNDERSTORM DEVELOPMENT. STORM CHANCES WILL BE ON THE DECLINE THROUGH MONDAY BEFORE COMING TO A QUIET HOLDING PATTERN THROUGH THE WEEK. MONSOON MOISTURE LOOKS TO HANG AROUND THIS WEEK BUT MAINLY ACROSS EASTERN ARIZONA. THE UPPER LEVEL DISTURBANCE IS PROGGED TO MOVE NORTH THROUGH THE GREAT BASIN BY MONDAY AND WILL ALLOW A WESTERLY FLOW TO SETTLE IN PLACE OVER THE SOUTHWEST DESERTS AS WELL AS A DRYING TREND. WILL KEEP SLIGHT CHANCE MENTION IN ZONE 24 FOR THE HIGHER TERRAIN LOCATIONS. TEMPERATURES WILL HAVE LITTLE DAY TO DAY CHANGE...REMAINING AT OR A FEW DEGREES ABOVE SEASONAL NORMAL WITH HIGH PRESSURE DOMINATING THE REGION THROUGH MID WEEK. THURSDAY THROUGH SATURDAY...ATTENTION THEN TURNS TO A POSSIBLE SEASONAL TRANSITION SYSTEM FOR LATE WEEK INTO NEXT WEEKEND. CONFIDENCE IS STILL NOT VERY HIGH ON THE SPECIFICS OF THE SYSTEM BUT THE 00Z OPERATIONAL MODELS HAVE COME IN CLOSER AGREEMENT THAT A DEEP PACIFIC TROUGH WILL SLIDE THROUGH CALIFORNIA ON FRIDAY AND POSSIBLY AS FAR SOUTH AS ARIZONA SOMETIME NEXT WEEKEND. WIDESPREAD SLIGHT CHANCE POPS ARE IN THE FORECAST FOR FRIDAY. EITHER WAY IT IS FAIRLY LIKELY THIS LOW WILL USER IN COOLER AND MUCH DRIER AIR...AND POTENTIALLY END OUR MONSOON SEASON. && .AVIATION... SOUTH-CENTRAL AND SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KPHX...KIWA...KSDL...KIPL...AND KBLH... AN UPPER LOW CENTERED OFF THE COAST OF SOUTHERN CALIFORNIA WILL PULL MONSOON MOISTURE NORTHWARD TODAY FOR SCT-BKN080-100 WITH SCATTERED SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN NORTH...EAST...AND SOUTH...OF THE PHOENIX AREA AND ISOLATED ELSEWHERE. ONSET OF SHOWERS POSSIBLE BEFORE 18Z. CONFIDENCE TOO LOW AN ANY GIVEN TAF SITE TO INSERT TEMPO SHWRS/TSTMS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... MONDAY THROUGH FRIDAY... MOISTURE RETREAT DUE TO WESTERLY FLOW WILL KEEP STORM CHANCES MINIMAL THROUGH THURSDAY AND LIMITED TO THE HIGHER MOUNTAINS OF SOUTH-CENTRAL ARIZONA. MEANWHILE...TEMPERATURES NUDGE UPWARD A FEW DEGREES ABOVE NORMAL. HUMIDITIES ON THE LOWER DESERTS DROP BELOW 15 PERCENT THOUGH MAX HUMIDITIES REMAIN FAIR. NO STRONG WINDS ARE EXPECTED DURING THIS TIME FRAME. ON FRIDAY...A PACIFIC WEATHER SYSTEM WILL PULL MOISTURE NORTHWARD OVER THE REGION FOR A RETURN OF STORM CHANCES...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY. IN ADDITION...COOLER TEMPERATURES AND BREEZY TO LOCALLY WINDY CONDITIONS CAN BE EXPECTED AS WELL. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...DEWEY AVIATION...AJ FIRE WEATHER...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
802 PM PDT SUN SEP 21 2014 .UPDATE... SATELLITE IMAGERY SHOWS UPPER LOW OVER WEST CENTRAL NV LIFTING NE TOWARD THE NORTH CENTRAL PART OF THE STATE. THIS IS IN LINE WITH CURRENT MODEL GUIDANCE. CONVECTION OVER THE FAR EASTERN PARTS OF THE CWA IS DISSIPATING...BUT THIS CONVECTION DID PRODUCE SOME HEAVIER RAINS OVER ISOLATED AREAS TODAY RESULTING IN TWO REPORTS OF WATER AND DEBRIS OVER STATE HIGHWAYS IN SOUTHEAST CHURCHILL COUNTY. THE HRRR STILL SHOWS CONVECTION DEVELOPING OVER THE FAR NRN CWA LATER THIS EVENING ASSOCIATED WITH A WEAK VORTICITY LOBE ROTATING AROUND THE UPPER LOW AND A LITTLE LINGERING CONVECTION OVER THE FAR EASTERN CWA. WITH THIS IN MIND HAVE DECREASED POPS FOR THE FAR WEST AND SOUTH BUT LEFT SOME SMALL POPS IN OVER THE FAR NORTH AND EAST THROUGH LATE EVENING. AS UPPER LOW EXITS LATE TONIGHT DRIER CONDITIONS SHOULD RETURN FOR MONDAY. ATTENTION TURNS TO THE SMOKE FROM THE KING FIRE THAT HAS MOVED BACK INTO THE WESTERN PART OF NEVADA AND NORTHEAST CALIFORNIA. THE SMOKE WAS A LITTLE THICKER LATE THIS AFTERNOON. THE THINNING OF THE SMOKE IS LIKELY A RESPONSE TO LESS FIRE ACTIVITY AND LIGHTER WINDS THIS EVENING. SMOKE FORECASTING CAN BE SOMEWHAT DIFFICULT AS IT RELIES LARGELY ON THE INTENSITY OF THE FIRE. EVEN THOUGH THE SMOKE HAS THINNED WE COULD SEE A RESURGENCE LATE TONIGHT AS THE ATMOSPHERE BECOMES MORE STABLE...OR IT COULD THIN MORE. WILL LEAVE THE DENSE SMOKE ADVISORY IN PLACE AS WINDS MONDAY SHOULD BECOME MORE WESTERLY THROUGH THE DAY AND DRIVE ANY SMOKE GENERATED BACK THIS DIRECTION. IT IS POSSIBLE THAT STRONGER WINDS LATER IN THE WEEK WILL RESULT IN EVEN MORE SMOKE IN THE TAHOE BASIN AND WRN NEVADA...BUT THIS REMAINS A BIT UNCERTAIN AT THIS TIME. 20 && .PREVIOUS DISCUSSION... /ISSUED 306 PM PDT SUN SEP 21 2014/ SYNOPSIS... SOUTHWEST FLOW AND BUILDING HIGH PRESSURE WILL THEN BRING WARMER AND DRIER CONDITIONS TO THE REGION THROUGH THE MIDDLE OF THE WEEK, ALONG WITH SMOKE TO THE REGION FROM THE ONGOING KING FIRE. STRONGER LOW PRESSURE BRINGS INCREASING WINDS AND COOLER TEMPERATURES WITH POSSIBLE RAIN LATER IN THE WEEK. SHORT TERM... LIGHT RAINFALL TODAY THROUGH THE SIERRA AND UP THROUGH FAR NORTHWEST NEVADA AS THE LOW PRESSURE PIVOTED THROUGH THE AREA. THE AREA THAT RECEIVED THE HIGHEST RAINFALL WAS IN EASTERN PERSHING AND CHURCHILL COUNTIES LAST NIGHT WHERE UP TO 0.50" FELL. OTHERWISE, ONLY LIGHT RAIN WAS REPORTED FOR OTHER AREAS. A FEW ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED IN WESTERN NEVADA THIS AFTERNOON. ONE SHOWER THAT MOVED INTO FERNLEY EARLIER PRODUCED BRIEF, BUT HEAVY RAINFALL IN THE AREA. THIS GOES TO SHOW THAT THE MOISTURE CONTENT IN THE AIR IS VERY HIGH, WITH EFFICIENT PRECIPITATION. ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE EVENING HOURS, THEN TAPER OFF AS LOW PRESSURE MOVES OUT OF THE REGION. ABUNDANT CLOUD COVER HAS REMAINED OVER THE REGION ALL DAY, KEEPING TEMPERATURES A BIT COOLER AND KEEPING THE AIR FROM MIXING. THIS WAS A BIG FACTOR IN THE SMOKE IN THE TRUCKEE AREA NOT BEING ABLE TO MIX OUT DUE TO THE LACK OF HEATING. WINDS AT RIDGE LEVEL HOWEVER ARE SHIFTING TO THE SOUTHWEST AND WILL BRING ADDITIONAL SMOKE INTO TAHOE BASIN AND RENO-CARSON-MINDEN AREAS AS WELL. A DENSE SMOKE ADVISORY HAS BEEN ISSUED THROUGH MONDAY AFTERNOON IN ANTICIPATION THAT SMOKE WILL BECOME WORSE OVER THE NEXT 24 HOURS. SMOKE DENSITY WILL ALSO DEPEND HIGHLY ON FIRE ACTIVITY OVER THE NEXT FEW DAYS, SO THE DENSE SMOKE ADVISORY WILL NEED TO BE REEVALUATED EACH AFTERNOON. BUT, WITH THE SOUTHWEST FLOW EXPECTED TO CONTINUE, SMOKE WILL REMAIN IN THE FORECAST THROUGH AT LEAST WEDNESDAY. DRY AND WARM CONDITIONS WILL RETURN TO THE REGION MONDAY AND TUESDAY AS HIGH PRESSURE BUILDS OVER THE REGION AND SOUTHWEST FLOW RETURNS ALOFT. EXPECT TEMPERATURES TO INCREASE TO ABOVE NORMAL AGAIN WITH MID TO UPPER 80S IN WESTERN NEVADA AND 70S IN THE SIERRA. HOON LONG TERM...WEDNESDAY THROUGH SUNDAY... A TROUGH OVER THE EAST PACIFIC WILL PROVIDE BREEZY SOUTHWEST WINDS BY MIDWEEK AHEAD OF A COLD FRONT WHICH WILL PROVIDE COOLER CONDITIONS AND CHANCES FOR SHOWERS THE SECOND HALF OF THE WEEK. THE FORECAST CONFIDENCE IN THE EXTENDED IS GOOD FOR WEDNESDAY AND THURSDAY BEFORE DEGRADING SIGNIFICANTLY OVERNIGHT THURSDAY INTO FRIDAY DUE TO LARGE DISCREPANCIES IN TIMING THE EJECTION OF THE UPPER LOW. FOR WED-THU, AXIS OF THE UPPER TROUGH WILL REMAIN JUST OFF THE WEST COAST WITH GUSTY WINDS MAINLY CONCENTRATED NORTH OF INTERSTATE 80 AS THE UPPER LEVEL JET BEGINS TO DROP ACROSS NE CALIFORNIA. STRONGER WINDS LOOK TO BECOME MORE WIDESPREAD BY THURSDAY AHEAD OF A FRONT AS THE SURFACE PRESSURE GRADIENT INTENSIFIES AND THE CORE OF 105+ KT JET CROSSES THE SIERRA. SUSTAINED SW-W WINDS IN THE 15-25 MPH RANGE ARE POSSIBLE THURSDAY BEFORE SHIFTING NORTHWEST BEHIND THE FRONT WITH MODELS PUSHING THE FRONT THROUGH OVERNIGHT THURSDAY INTO EARLY FRIDAY. COOLER CONDITIONS ARE EXPECTED BEHIND THE FRONT WITH POSSIBLE HIGH TEMPERATURES ACROSS WESTERN NEVADA ONLY IN THE UPPER 60S TO LOWER 70S AND LOWER 60S ACROSS SIERRA VALLEYS. CONSIDERABLE UNCERTAINTY EXISTS WITH HOW QUICKLY THE LOW DEPARTS WITH THE GFS BEING MUCH QUICKER THAN THE EC WHICH LINGERS THE LOW OVER THE REGION THROUGH NEXT WEEKEND. THE EC WOULD PROVIDE US WITH A COOLER AND WETTER FORECAST THAN THE WARMER AND DRIER SOLUTION OF THE GFS. LITTLE CHANGE MADE IN THE FORECAST FOR NEXT WEEKEND AS TRENDS AND ENSEMBLE RUNS OFFER LITTLE CONFIDENCE TO MAKE MANY ADJUSTMENTS. WILL MAINTAIN SLIGHT CHANCES FOR SHOWERS AND A SLOWER WARMUP IN THE FORECAST BEYOND FRIDAY. FUENTES AVIATION... THE KING WILDFIRE ALONG THE WEST SLOPES OF THE SIERRA WILL CONTINUE TO PUSH SMOKE AND HAZE ACROSS THE TERMINALS WITH SURFACE VIS AS LOW AS 1SM POSSIBLE AT KTVL/KTRK AND LESS THAN 3SM POSSIBLE AT KCXP/KRNO. OTHERWISE, BRIEF PERIODS OF MVFR CIGS/VIS IN -SHRA ARE POSSIBLE THROUGH 06Z THIS EVENING BUT CHANCES WILL REMAIN GENERALLY BELOW 15% ACROSS ALL TERMINALS BEFORE DIMINISHING OVERNIGHT. THE MAIN STORY INTO MIDWEEK WILL BE ANOTHER APPROACHING LOW PRESSURE SYSTEM THAT WILL INCREASE SOUTHWESTERLY WINDS AND SMOKE TRANSPORT INTO KTVL/KTRK/KCXP/KRNO. MOUNTAIN OBSCURATION AND DECREASED SURFACE VIS WILL BE AN ISSUE AND WILL LIKELY CONTINUE EACH DAY THROUGH AT LEAST THURSDAY ASSUMING THE KING FIRE REMAINS ACTIVE. FUENTES && .REV WATCHES/WARNINGS/ADVISORIES... NV...DENSE SMOKE ADVISORY UNTIL 5 PM PDT MONDAY NVZ002-003. CA...DENSE SMOKE ADVISORY UNTIL 5 PM PDT MONDAY CAZ072. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
833 AM PDT Sat Sep 20 2014 .Synopsis... Lingering Sierra showers/t-storms are possible through the weekend, otherwise, dry & warmer temperatures into early next week. Cooler and wetter weather arrives middle of next week into next weekend. && .Discussion... Satellite imagery shows a cut off 578dm closed low centered just west of the Channel Islands near Oxnard. This closed circulation center is sitting directly under the apex of a ridge covering most of the western US. Water vapor imagery indicates cloud enhancement is presently occurring over the Motherlode and west slope of Sierra Nevada this morning. Due to this and other subtle discrepancies, we have decided to increase coverage and probability of precipitation throughout the next 12 hours and sent out an update. Near term model guidance is fairly consistent in bringing in showers/thunderstorms above 4000 feet in the Sierra. Unfortunately, the HRRR model, which has quickly become an office favorite for short term guidance is currently unavailable. The NAM12 model has been overforecasting convection over the last week, so we are throwing out that model as it again appears to be overforecasting the weekends convection. We will continue to keep a close watch on the development of any convection in the northeastern sector of the closed low and send out updates as necessary. DRP .Previous Discussion... A closed low is currently straddling the central CA coastline. It will linger over our region today and gradually move northeastward by tonight. On Sunday, the low will be centered over Nevada with the backside of the low still impacting the Sierra. Have kept mention of showers and thunderstorms over the Sierra this weekend. The WRF model indicates that there will be more showers on the western side of the crest Sunday. The rest of our CWA will remain dry with near to above normal temperatures through Tuesday. Daytime highs will generally be at their warmest today compared to the rest of the upcoming 7 days. For the short term forecast, max temperatures will range mid 80s to upper 90s across the valley. Smoke from the King Fire will continue to impact the Sierra and foothills into the adjacent Southern Sacramento valley. Hazy conditions surrounding the smoky area will extend from the Central Sacramento valley into the Northern San Joaquin valley. On Sunday, general wind pattern will transition to a weak onshore flow which should push smoky/hazy conditions eastward. Short wave ridging behind the closed upper low moves over NorCal Sunday into Monday for dry weather. Temperatures trend down slightly over the weekend but remain near to a little above normal into Monday. JBB .Extended Discussion (Wednesday through Saturday) Models remain in good agreement that a stronger trough will impact the region from Wednesday into the weekend. On Wednesday, max temperatures will finally dip below normal. In addition, the chance for showers will start impacting the NorCal coastline Wednesday morning. Showers should spread over the Coastal range and nudge into the Sacramento valley by Wednesday afternoon/evening. The chance of showers will continue to spread eastward and southward encompassing the majority of our CWA Thursday and Friday. Daytime highs will be well below normal Thursday into Saturday ranging 5 to 15 degrees below average. The one discrepancy to watch in the models is that the GFS is more progressive in moving the trough eastward out of our region on Saturday while the ECMWF model has the trough still lingering. Have kept mention of showers on Saturday, but started to diminish them across the valley by Saturday night. JBB && .Aviation... VFR conditions the next 24 hours all TAF sites. MVFR visibility in smoke possible in the vicinity of the King Fire. Isolated TS also possible along the higher Sierra 18z today through 06Z Sunday. North to east winds to 10 knots this morning transitioning to southerly this afternoon and tonight. && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
940 PM PDT FRI SEP 19 2014 .SYNOPSIS... A SLOW MOVING TROUGH WILL CONTINUE TO BRING COOLER WEATHER AND A DEEP MARINE LAYER THROUGH SUNDAY. PATCHY DRIZZLE IS POSSIBLE AGAIN LATE TONIGHT AND TOMORROW MORNING. A WARMING TREND AND SHALLOWER MARINE LAYER IS EXPECTED MONDAY THROUGH WEDNESDAY AS HIGH PRESSURE BUILDS ALOFT. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... THE MARINE LAYER IS A LITTLE DEEPER THAN LAST NIGHT BUT THE STRATUS COVERAGE IS NOT NEARLY AS WIDESPREAD. ONLY SCATTERED LOW CLOUDS COVER THE COASTAL WATERS THIS EVENING. STILL EXPECT THE CLOUDS INCREASE OVERNIGHT AND SPREAD INTO THE VALLEYS...BUT THE ADVANCING UPPER LOW COULD DISRUPT THE COVERAGE SO IT MAY NOT BE THE UNIFORM CLOUD DECK THAT WE SAW THIS MORNING. 00Z WRF STILL OUTPUTTING LIGHT QPF SO THERE MAY BE AREAS OF DRIZZLE AGAIN TOMORROW MORNING. WATER VAPOR IMAGE SHOWS THE UPPER TROUGH WEST OF PT CONCEPTION THIS EVENING. IT WILL MOVE EAST TONIGHT...THEN BRIEFLY STALL OVER PT CONCEPTION SATURDAY BEFORE EJECTING NORTHEAST TOWARD NEVADA SATURDAY NIGHT AND SUNDAY. THE NAM4 AND CANSAC GENERATE STILL GENERATE SMALL QPF OVER THE SBD/RIV COUNTY MTNS SATURDAY AFTERNOON WITH THE PASSAGE OF THE UPPER VORT MAX...SO WILL HOLD ONTO THE SLT CHANCE FOR SHRA/TSTMS THERE. THE WRFEMS AND HRRR MODELS ARE DRY. THE LOW MOVES ACROSS NEVADA SUNDAY WITH A SMALL INCREASE IN HTS AND A FEW DEGREES OF WARMING. GREATER WARMING AND A SHALLOWER MARINE LAYER MON-WED FROM WEAK RIDGING BUILDING OVER THE SOUTHWEST. THE GFS SHOWS SOME INCREASE IN PRECIPITABLE WATER WEDNESDAY AS LOW LEVEL WINDS SHIFT SOUTHERLY...BUT PRECIP IS NOT EXPECTED. LONG RANGE OUTLOOK LATE NEXT WEEK...THE GFS AND GEM FORECAST A DEEP TROUGH TO MOVE INTO THE WEST COAST THURSDAY THROUGH SATURDAY WHICH WOULD BRING COOLING...A DEEPER MARINE LAYER AND GUSTY MTN AND DESERT WINDS. THE OUTLIER IS THE ECMWF WHICH HOLDS ONTO WEAK RIDGING INTO THE WEEKEND. THERE IS A 100DM HEIGHT SPREAD BETWEEN THE MODELS WHICH IS SIGNIFICANT. HAVE TRENDED TOWARD ECMWF SINCE IT HAS BEEN PERFORMING BETTER THAN THE GFS LATELY...AND HAVE TEMPERED THE COOLING SOMEWHAT IN THE THU-SAT TIME FRAME. && .AVIATION... 200300Z...LOW CLOUDS WILL MOVE ASHORE THROUGH THE EVENING WITH BASES 1500-2000 FEET MSL AND SPREAD INTO INLAND VALLEYS OVERNIGHT. TOPS WILL BE AROUND 3000 FEET. LOCAL VIS 3-5SM IN FAR INLAND VALLEYS. SCATTER OUT SATURDAY BY 17-19Z. OTHERWISE...SKIES WILL BE CLEAR AND VIS UNRESTRICTED THROUGH SATURDAY. ON SATURDAY AFTERNOON IN THE MOUNTAINS THERE WILL BE SOME CUMULUS BASED AROUND 8000 FEET AND A VERY SMALL CHANCE OF THUNDERSTORMS OVER THE MOUNTAINS OF RIVERSIDE/SAN BERNARDINO COUNTIES. && .MARINE... 800 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY. && .SKYWARN... SPOTTER ACTIVATION WILL NOT BE NEEDED THIS WEEKEND. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...MOEDE AVIATION/MARINE/BEACHES...MM
AREA FORECAST DISCUSSION
NWS PUEBLO CO
912 PM MDT SUN SEP 21 2014 .UPDATE... ISSUED AT 856 PM MDT SUN SEP 21 2014 UPDATED TO ADJUST POPS BASED ON THE CURRENT RADAR AND SATELLITE TRENDS. A LARGE UPPER LEVEL LOW IS SPINNING ACROSS NORTHEAST NEVADA WITH AN UPPER DISTURBANCE IN THE FLOW LIFTING INTO THE FOUR CORNERS REGION. AN INCREASE IN THUNDERSTORM ACTIVITY IS NOTED OVER THE FOUR CORNERS WHICH WILL SPREAD EASTWARD ACROSS THE CONTINENTAL DIVIDE THROUGH MIDNIGHT. THERE HAVE BEEN SOME LIGHT ECHOES OVER THE I-25 CORRIDOR AND RATON MESA AREA...BUT NOTHING TOO ORGANIZED AT THIS TIME. MODELS ARE ALL STILL GENERATING A DECENT BAND OF SHOWERS AND THUNDERSTORMS LIFTING ACROSS THE AREA OVERNIGHT BUT FEEL THEY MAY BE OVER DOING THINGS A BIT. FOR NOW HAVE THE HIGHEST POPS AFTER MIDNIGHT ALONG THE SAN JUAN RANGE...WITH DECREASING CHANCES AS YOU HEAD EAST INTO THE PLAINS. MODELS HAVE NOT HANDLED OVERNIGHT CONVECTION WELL THE PAST COUPLE OF NIGHTS...SO WE WILL SEE HOW THINGS UNFOLD OVER THE NEXT COUPLE OF HOURS. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 322 PM MDT SUN SEP 21 2014 ...HEAVY RAIN POSSIBLE TONIGHT OVER SAN JUAN MOUNTAINS...MARGINAL SEVERE POSSIBLE ON PLAINS TOMORROW AFTERNOON... CURRENTLY... DRIER AIR NOTED OVER PLAINS AS DWPTS OVER FAR EC COLO IN THE 30S...WITH U40S/50S ALONG THE I-25 CORRIDOR. MTNS MAINLY IN THE 40S...WITH MUCH RICHER MOISTURE SW OF THE FCST AREA. AREA OF RAIN OVER THE CONTDVD EARLIER HAS DISSIPATED...ALTHOUGH CONVECTIVE SHOWERS WERE DEVELOPING OVER MOST OF THE HIGHER TRRN. A FEW ISOLD POPS WERE NOTED OVER FAR N EL PASO COUNTY. A FEW CG FLASHES WERE NOTED WITH THE DEVELOPING CONVECTION...BUT THE BRUNT OF THE INTENSE LTG ACTIVITY WAS STILL ASSOCIATED WITH THE TROUGH BACK INTO E UTAH. REST OF THIS AFTERNOON INTO TONIGHT... MAIN CONCERN THIS PERIOD WILL BE THE MOUNTAINS ALONG THE CONTDVD...ESPECIALLY THE SAN JUANS. ALL GUIDANCE IS INDICATING BEST CHANCE OF HEAVY PRECIP WILL BE OVER THE SW FACING SLOPES OF THE SAN JUANS. MOST OF THE PRGD HEAVY PRECIP WILL BE IN NWS GJT AREA OF RESPONSIBILITY...BUT SOME OF THIS PRECIP WILL LIKELY MAKE IT OVER THE DIVIDE. WILL WAIT TIL LATE THIS AFTERNOON TO DECIDE IF A FLASH FLOOD WATCH IS NEEDED. PROS FOR A WATCH IS MODEL FCST...BUT WE (NWS PUB) REALLY HAVE NOT RECEIVED HEAVY RAIN OVER THIS REGION SO SOILS ARE NOT ALL THAT SATURATED. 18Z NAM HAS BEEN SHOWING LOTS OF PRECIP OVER THE GREATER PIKES PEAK REGION BUT I AM DISCOUNTING THIS DUE TO ITS POOR PERFORMANCE THE LAST SEVERAL RUNS. RAP GUIDANCE IS QUITE A BIT DRIER. GFS ALSO A LOT DRIER PIKES PEAK REGION. OVER THE REST OF THE REGION...I DONT THINK THE PLAINS WILL SEE MUCH IN THE WAY OF PRECIP THE REST OF THIS AFTERNOON OR TONIGHT. SOME SHOWERS WILL BE POSSIBLE MAINLY WEST OF THE INTERSTATE...AND ACROSS N EL PASO COUNTY...BUT THE REST OF THE REGION SHOULD REMAIN DRY. SOME LOW CLOUDS/FOG WILL BE POSSIBLE ACROSS N EL PASO COUNTY TONIGHT GIVEN THE MOIST UPSLOPE FLOW. TOMORROW.... TROUGH ALOFT WILL MOVE ACROSS THE REGION. IT APPEARS NOW THAT THE SFC TROUGH WILL REMAIN IN COLORADO DURING PRIME HEATING AND WE WILL LIKELY HAVE A BROKEN LINE OF CONVECTION MOVE ACROSS THE PLAINS DURING THE AFTERNOON TIME PERIOD. SHEAR LOOKS GOOD BUT CAPE LOOKS MARGINAL SO SVR THREAT WILL BE MINIMAL. QUITE A FEW CLOUDS MAY BE OVER THE AREA TOMORROW AND THAT COULD LIMIT HEATING. MOUNTAINS SHOULD GRADUALLY DRY OUT TOMORROW. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 322 PM MDT SUN SEP 21 2014 MONDAY NIGHT...THE UPPER LOW WILL TRACK E ACROSS WY AND INTO THE DAKOTAS MON EVE...GRADUALLY BRINGING AN END TO PCPN FROM WEST TO EAST. CONVECTION IS FORECAST TO BECOME ISOLATED BY MIDNIGHT ACROSS THE FAR E PLAINS...THEN COME TO AN END EARLY TUE MORN ALONG THE CO/KS BORDER. TUESDAY AND WEDNESDAY...A RIDGE OF HIGH PRESSURE BUILDS OVER THE REGION...ALLOWING FOR PREDOMINANTLY DRY CONDITIONS AND MAX TEMPS IN THE 80S FOR THE PLAINS...AND 70S FOR THE HIGH VALLEYS. ISOLATED CONVECTION IS EXPECTED TO LINGER OVER THE FAR SE CORNER AS WELL AS THE SOUTHERN PORTIONS...INCLUDING THE S SANGRES. THURSDAY AND FRIDAY...THE UPPER RIDGE BEGINS TO SLIDE TO THE EAST...AS AN UPPER TROUGH OF LOW PRESSURE BEGINS TO MOVE ONSHORE ALONG THE WEST COAST. THIS WILL START TO DRAW INCREASING MOISTURE UP ACROSS THE 4 CORNERS AND INTO WESTERN CO...WHICH IN TURN INCREASES POPS FOR THE MTS AND WESTERN AREAS FROM THU AFTN ONWARD. A SLIGHT COOLING TREND IS EXPECTED FROM THU THROUGH FRI...THOUGH TEMPS WILL STILL BE AT OR SLIGHTLY ABOVE SEASONAL NORMS. SATURDAY AND SUNDAY...EXTENDED MODELS AGREE ON MOVING THE UPPER TROUGH AXIS ACROSS THE PAC NW AND GREAT BASIN ON SAT...THROUGH THE EC IS JUST A BIT SLOWER. THE TROUGH DEEPENS WITH A CLOSED LOW DEVELOPING BY SUN...WHICH THEN SLOWLY MOVES EAST TOWARD COLORADO. THE EC HAS THIS LOW OVER NV...WHILE THE GFS HAS THIS LOW EDGING INTO THE WESTERN HALF OF COLORADO...SO STILL SOME ROOM FOR NEGOTIATION THERE. END RESULT IS THAT A COOLER PERIOD WITH INCREASED CLOUDS AND PCPN COVERAGE IS FORECAST FOR THE WEEKEND...AND THE FINER POINTS AND TIMING WILL HAVE TO BE REVISITED THROUGHOUT THE UPCOMING WORK WEEK. MOORE && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 322 PM MDT SUN SEP 21 2014 KCOS...MAIN CONCERN IS MOIST UPSLOPE FLOW LATER TONIGHT WHICH WILL LIKELY BRING SOME LOW CIGS INTO THE TAF SITE. FOR TOMORROW...A LINE OF BKN CONVECTION SHOULD MOVE ACROSS THE TAF SITE EARLY TOMORROW AFTERNOON...WITH CLEARING SKIES THEREAFTER. KPUB...MAINLY VFR NEXT 24H. COULD SEE SOME LOW CIGS LATE TONIGHT/EARLY TOMORROW MORNING FOR A FEW HOURS. KALS...COULD SEE SCTD SHOWERS WHICH MAY BRING BRIEF MVFR CONDITIONS TONIGHT AND EARLY TOMORROW...OTHERWISE VFR. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY SHORT TERM...HODANISH LONG TERM...MOORE AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
234 PM MDT SAT SEP 20 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 1224 PM MDT SAT SEP 20 2014 MDLS CONTINUE TO MOISTEN UP THE AIRMASS OVERNIGHT AND SUNDAY. FOR THIS EVENING...THE LATEST HRRR APPEARS TO KEEP ANY DEVELOPING THUNDERSTORMS IN THE MOUNTAINS WEST AND SOUTHWEST OF DENVER. THE AIRMASS REMAINS TOO DRY AND STABLE ELSEWHERE TO SUPPORT ANY DEEP CONVECTION. THE UPPER RIDGE WILL REMAIN OVER EASTERN COLORADO TONIGHT...WITH LOW LEVEL ESELY SFC WINDS. THE UPPER LOW WILL BE OVER SWRN NV SUNDAY MORNING AND WILL MOVE SLOWLY INTO NERN NV BY 00X MONDAY. THE QG ASCENT THROUGH THE PERIOD WILL BE WEAK BUT PRECIPITABLE WATER VALUES WILL CLIMB BACK OVER AN INCH. WITH THE COOLER AMS IN PLACE...LIMITED HEATING COUPLED WITH WEAK FORCING ALOFT SHOULD ALLOW FOR MORE SHOWERS VS THUNDERSTORMS IN THE FORECAST. WL CONTINUE WITH SCT-LIKELY POPS ACROSS THE MOUNTAINS AND FOOTHILLS WITH MORE EMPHASIS ON SHOWERS IN THE GRIDS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 230 PM MDT SAT SEP 20 2014 NOT A LOT OF DIFFERENCE IN THE MODEL SOLUTIONS DURING THE PERIOD. THE UPPER LOW CURRENTLY WEST OF LOS ANGELES IS PREDICTED TO LIFT TO THE NORTHEAST WITH ITS ASSOCIATED TROUGH PASSING EAST OF THE STATE TUESDAY MORNING. THE RESULT OF THIS IS A QUANTITATIVELY MODEST BUT DEEP AND PROLONGED PERIOD OF QUASIGEOSTROPHIC ASCENT OVER MOST OF THE AREA BEGINNING TONIGHT AND CONTINUING THROUGH MONDAY NIGHT. THIS ASCENT SHOULD DIMINISH FROM WEST TO EAST DURING THE DAY TUESDAY AS UPPER LEVEL RIDGING OCCURS OVER THE CENTRAL ROCKIES. CONSEQUENTLY EVERYONE SHOULD HAVE A SHOT AT SOME PRECIPITATION AS THIS SYSTEM PASSES BY EARLY IN THE PERIOD WITH DRIER CONDITIONS EXPECTED AFTER TUESDAY. PRECIPITABLE WATER VALUES ARE FORECAST TO EXCEED 1.00 INCH WITH THIS SYSTEM AND WITH MODERATE CAPE VALUES AROUND AT TIMES THE THREAT OF SOME HEAVY SHOWERS CANNOT BE COMPLETELY RULED OUT IN THE SUNDAY NIGHT THROUGH TUESDAY MORNING TIME FRAME. AT PRESENT HOWEVER IT IS DIFFICULT TO SINGLE OUT ANY PARTICULAR AREA FOR ANY ENHANCED FLOODING THREAT. && .AVIATION...(FOR THE TAFS THROUGH 00Z SUNDAY LATE AFTERNOON) ISSUED AT 1224 PM MDT SAT SEP 20 2014 VFR CIGS/VSBYS THROUGH 06Z...THE AMS DOES MOISTEN UP OVERNIGHT WITH LCL LOWERING ENOUGH TO PRODUCE ILS APPROACHES WITH OCNL BKN- OVC CIGS OF 050-060 KFT AGL AFTER 06Z. ISOLD RAIN SHOWERS POSSIBLE SUNDAY MORNING...WITH BETTER POTENTIAL FOR SHOWERS ALONG THE FOOTHILLS ON SUNDAY. COOLER AMS WL KEEP THE POTENTIAL FOR TSTMS ON THE LOW SIDE...WITH A BETTER CHC FOR RAIN SHOWERS SUNDAY AFTN. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COOPER LONG TERM...ET AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1000 PM EDT SUN SEP 21 2014 .SYNOPSIS... A PERIOD OF STEADY RAIN WILL AFFECT THE FAR SOUTHEAST NEW ENGLAND COAST THIS EVENING. OTHERWISE...DRIER AND LESS HUMID WEATHER IS ON TAP FOR MONDAY AS A DRY COLD FRONT SWEEPS ACROSS THE REGION. STRONG HIGH PRESSURE WILL BRING SUNNY DAYS AND CLEAR NIGHTS TO THE REGION FROM TUESDAY THROUGH NEXT WEEKEND WITH A WARMING TREND. WE COULD APPROACH RECORD WARMTH ON SATURDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 10 PM UPDATE... A BAND OF STEADY RAIN HAS GENERALLY DIMINISHED ACROSS PORTIONS OF E MA THIS EVENING AS LOW PRES DEVELOPING OFFSHORE BEGINS TO SHIFT NE. A FEW MORE SHOWERS ARE LIKELY TO REMAIN FROM THIS BUT JUST OVER THE NEXT COUPLE OF HOURS. OTHERWISE...HAVE BEEN WATCHING A DOWNWARD TREND IN CONVECTIVE ACTIVITY IN NY ASSOCIATED WITH THE COLD FRONT...STILL A BIT OF -SHRA ACTIVITY LEFT...BUT NOT MUCH CONVECTION. LOOKS LIKE MAINLY WRN MA AND SW NH WILL BE HAVE THIS RAIN IN THE CARDS BUT GENERALLY AFTER 03Z. AFTER THAT...THE RAPID ENTRAINMENT OF DRY AIR...LONG SINCE LOSS OF DIURNAL HEATING AND SHIFT OF BEST DYNAMICS INTO NRN NEW ENGLAND SHOULD ALLOW FOR MOST OF THESE TO DISSIPATE SUCH THAT VERY LITTLE ACTIVITY...ASIDE FROM A BRIEF GUST OF WIND AND WIND SHIFT...IS SEEN ELSEWHERE WITH THIS FROPA. OTHERWISE...A POCKET OF VERY DENSE FOG HAS DEVELOPED FROM THE N SHORE OF MA INTO COASTAL MAINE. THIS WILL LIKELY CONTINUE INTO THE MORNING HOURS. HAVE ISSUED A DENSE FOG ADVISORY FOR THIS AREA. OTHERWISE...ONLY OTHER LOCATIONS REPORTING UNDER HALF A MILE ARE ORH AND TAN...BUT FEEL THESE ARE LIKELY MORE COLOCATED WITH THE AIRPORT. PREVIOUS DISCUSSION... MARGINAL INSTABILITY WITH DEEP LOW LEVEL MOISTURE HAS ALLOWED ISOLATED TO SCATTERED SHOWERS TO CONTINUED TO AFFECT SOUTHERN NEW ENGLAND. WE SHOULD SEE THIS ACTIVITY DIMINISH EARLY THIS EVENING WITH THE LOSS OF DAYTIME HEATING. THE MAIN CONCERN WILL BE THE SURFACE LOW PRESSURE SYSTEM OFF THE MID ATLANTIC COAST WHICH WILL BE TRACKING NORTHEAST AND PASSING NEAR THE BENCHMARK THIS EVENING. THE MAIN QUESTION IS HOW FAR NORTHWEST THE RAIN SHIELD WILL GET. LATEST NEAR TERM GUIDANCE HAS BEEN TRENDING FURTHER NORTHWEST. THEREFORE...EXPECT A PERIOD OF STEADY RAIN ACROSS THE CAPE/ISLANDS AND PROBABLY FURTHER NORTHWEST INTO INTERIOR SOUTHEAST MA/RHODE ISLAND FOR AT LEAST A TIME. IN FACT...LATEST HRRR SHOWING THE POTENTIAL FOR A BRIEF PERIOD OF RAIN ACROSS THE NORTHEAST MA COAST INCLUDING BOSTON. NOT SURE IF IT WILL GET THAT FAR NORTHWEST...BUT ITS CERTAINLY POSSIBLE. REGARDLESS...THE HEAVIEST RAINFALL WILL OCCUR ACROSS NANTUCKET... WHERE BETWEEN 0.50 TO PERHAPS UP TO 1 INCH OF RAIN MAY OCCUR. THE RAIN MAY PERSIST THROUGH MUCH OF THE EVENING ACROSS THE CAPE AND ISLANDS...BUT SHOULD WIND DOWN NEAR OR JUST AFTER MIDNIGHT. MEANWHILE...ONCE THE ISOLATED TO SCATTERED DIURNALLY DRIVEN SCATTERED SHOWERS WIND DOWN EARLY THIS EVENING...THE REST OF THE REGION WILL MAINLY BE DRY TONIGHT. HOWEVER...A COLD FRONT WILL BE APPROACHING OUR WESTERN ZONES TOWARD MIDNIGHT. WHILE SHEAR IS QUITE IMPRESSIVE...VERY LITTLE INSTABILITY WILL BE LEFT. SO WHILE WE MAY SEE A FEW SPOT SHOWERS AFFECT OUR WESTERN ZONES...THEY WILL BE IN THE PROCESS OF WEAKENING AND NOT EXPECTING MUCH MORE THAN THAT. LOW TEMPS WILL ONLY BOTTOM OUT IN THE UPPER 50S AND THE LOWER 60S BY DAYBREAK MONDAY. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... MONDAY... A MUCH DRIER AIRMASS WILL WORK INTO THE REGION BEHIND THE COLD FRONT ON MONDAY. WHILE PARTLY TO MOSTLY SUNNY SKIES ARE EXPECTED EARLY...MAY SEE A SCATTERED TO BROKEN DECK OF STRATO- CUMULUS CLOUDS WORK INTO AT LEAST THE INTERIOR BY AFTERNOON. HIGHS SHOULD MAINLY BE IN THE 60S ACROSS THE INTERIOR...BUT STILL WILL REACH BETWEEN 70 AND 75 ALONG HE COASTAL PLAIN. GUSTY WEST WINDS OF 20 TO 30 MPH ARE EXPECTED AS BUFKIT SOUNDINGS SHOWING VERY GOOD MIXING. HIGH SURF...GIVEN LARGE SOUTH TO SOUTHEAST SWELL FROM DEPARTING COASTAL LOW PRESSURE SYSTEM HAVE ISSUED A HIGH SURF ADVISORY FOR THE SOUTH COAST ON MONDAY. WE ISSUE HIGH SURF PRODUCTS THROUGH THE END OF SEPTEMBER IF CONDITIONS WARRANT. MONDAY NIGHT... HIGH PRESSURE WILL BE BUILDING IN FROM THE WEST. THIS WILL ALLOW FOR DIMINISHING WINDS AND SKIES TO BECOME MOSTLY CLEAR. LOOKS LIKE A PRETTY GOOD NIGHT OF RADIATIONAL COOLING...WITH LOWS BOTTOMING OUT IN THE UPPER 30S TO THE MIDDLE 40S IN MOST LOCALES. THE URBAN HEAT ISLAND OF BOSTON WILL BE THE MILD SPOT WITH THE LOW BOTTOMING OUT NEAR 50. && .LONG TERM /TUESDAY THROUGH SUNDAY/... HIGHLIGHTS... * HIGH PRESSURE AND DRY WEATHER THROUGH THE PERIOD * NEAR RECORD WARMTH POSSIBLE NEXT SATURDAY OVERVIEW... VERY GOOD AGREEMENT AMONGST MODEL GUIDANCE THE ENTIRE FORECAST PERIOD. AN UPPER LEVEL TROUGH DEPARTS THE NORTHEAST STATES ON TUESDAY. THEN...MUCH ADO ABOUT BUILDING HIGH PRESSURE...BOTH AT THE SURFACE AND ALOFT THE REMAINDER OF THE WEEK. THE UPPER RIDGE IS VERY STRONG AS IT IS PARKED FROM THE GREAT LAKES TO SOUTHERN NEW ENGLAND BY NEXT WEEKEND. DETAILS... TUESDAY WILL FEATURE MOSTLY SUNNY SKIES EXCEPT ONLY PARTLY SUNNY NW MA AND SW NH CLOSER TO SOME HIGHER 925 MB HUMIDITY. OTHERWISE...EXPECT SUNNY DAYS AND CLEAR NIGHTS THROUGH NEXT WEEKEND. HAVE GONE A FEW DEGREES LOWER THAN MODEL CONSENSUS TEMPERATURE MINIMUMS THROUGH THU DUE TO EXCELLENT RADIATIONAL COOLING EXPECTED ALONG WITH VERY DRY DEWPOINTS. AS THE CENTER OF THE UPPER HIGH APPROACHES...AM EXPECTING A DRAMATIC WARMUP FRI AND ESPECIALLY SAT. THE 12Z ECMWF RUN IS EVEN WARMER THAN THE PREVIOUS RUN WITH 925 MB TEMPERATURES WARMING FROM +12C TUE...TO +17C FRI... TO +19C OR +20C ON SAT... WITH WARM TEMPERATURES LIKELY CONTINUING INTO EARLY THE FOLLOWING WEEK. HAVE GONE SEVERAL DEGREES ABOVE MODEL CONSENSUS MAXIMUMS FOR NEXT SATURDAY...WITH HIGHS SOARING TO 80 TO 85 ACROSS INTERIOR SOUTHERN NEW ENGLAND. RECORDS FOR THAT DAY INCLUDE 85 AT WORCESTER AND 86 AT BOTH BOSTON AND PROVIDENCE. LIGHT WINDS ARE EXPECTED FOR THE PERIOD...SO ALTHOUGH IT WILL BE DRY WE ARE NOT EXPECTING FIRE WEATHER CONCERNS. LOCAL SEA BREEZES WILL OCCUR...ESPECIALLY FRI THROUGH NEXT SUNDAY. IT SHOULD BE NOTED THAT THE GFS HAS A HINT OF A POTENTIAL BACKDOOR FRONT/TROUGH OVER NORTHEAST MA ON SAT BUT THIS WAS NOT ENOUGH TO DETRACT FROM THE VERY WARM FORECAST...AS YET. AN UPPER LOW OVER VIRGINIA AND AN ASSOCIATED INVERTED TROUGH IS LIKELY TO BE CAUSING PRECIPITATION IN THE MID ATLANTIC REGION MID TO LATE IN THE WORK WEEK THAT TRIES TO WORK ITS WAY NORTHWARD. THERE IS EXCELLENT MODEL AGREEMENT THAT THIS AREA ONLY GETS AS FAR NORTHWARD AS OFF THE NJ COAST BY FRI...BEFORE RETREATING SOUTHWARD AS STRONG HIGH PRESSURE BECOMES ESTABLISHED OVER THE NORTHEAST ON THE WEEKEND. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY NIGHT/... TONIGHT...LOW TO MODERATE CONFIDENCE. IFR CONDITIONS WITH SOME LOW IFR CONDITIONS ACROSS FAR SOUTHEAST MA INCLUDING THE CAPE AND ISLANDS WITH VISIBILITIES BELOW 1/2 MILE AT TIMES IN LOCALLY DENSE FOG. MOST OF THE REST OF THE REGION WILL BE MVFR CEILINGS...WITH MANY AREAS BECOMING IFR CEILINGS BETWEEN 02Z AND 06Z. BEST CONFIDENCE FOR IFR IS FROM ABOUT A JAFFREY-WORCESTER-WILLIMANTIC LINE EASTWARD. STEADY RAIN WITH EMBEDDED SHOWERS WILL AFFECT THE FAR SOUTHEAST NEW ENGLAND COAST THIS EVENING. THE RAIN WILL LIKELY REACH INTO RHODE ISLAND/INTERIOR SOUTHEAST MA FOR A SHORT TIME AND PERHAPS EVEN INTO NORTHEAST MA. MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE IN VFR CONDITIONS. JUST A LOW RISK FOR BRIEF MVFR CIGS ACROSS THE INTERIOR ON MONDAY AS A DECK OF STRATOCUMULUS CLOUDS MOVES INTO THE REGION. OTHERWISE...GUSTY WEST TO NORTHWEST WINDS OF 20 TO 25 KNOTS EXPECTED DURING THE DAY MONDAY. KBOS TERMINAL...MODERATE CONFIDENCE TONIGHT WITH HIGH CONFIDENCE ON MONDAY. KBDL TERMINAL...MODERATE CONFIDENCE TONIGHT WITH HIGH CONFIDENCE ON MONDAY. OUTLOOK...TUESDAY THROUGH FRIDAY... HIGH CONFIDENCE. TUE...VFR. WED...VFR THU...VFR. FRI...VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... TONIGHT...MODERATE TO HIGH CONFIDENCE. LOW PRESSURE PASSING NEAR THE BENCHMARK WILL RESULT IN ENOUGH SOUTH TO SOUTHEAST SWELL FOR SCA SEAS TO DEVELOP ACROSS THE OUTER-WATERS AND WESTERN SOUNDS. SOUTHEAST WINDS SHOULD BECOME SOUTHWEST TONIGHT AT 10 TO 15 KNOTS LATER TONIGHT. AREAS OF FOG...SOME LOCALLY DENSE...WILL OCCUR ACROSS THE WATERS...ESPECIALLY SOUTH OF BOSTON HARBOR. MONDAY AND MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. SCA SEAS ON THE WESTERN SOUNDS AND OUTER-WATERS WILL CONTINUE THROUGH MONDAY NIGHT. IN ADDITION...A PERIOD OF WEST TO NORTHWEST WIND GUSTS NEAR 25 KNOTS IS POSSIBLE FOR A TIME ON MONDAY. THEREFORE...IT IS POSSIBLE WE MAY NEED TO EXPAND SCA FOR A TIME DURING THE DAY MONDAY INTO SOME OF THE NEARSHORE SOUNDS AND WATERS. CONFIDENCE NOT QUITE HIGH ENOUGH TO DO THIS RIGHT NOW... SO WILL DEFER TO THE NEXT SHIFT. OUTLOOK...TUESDAY THROUGH FRIDAY... HIGH CONFIDENCE... TUE AND WED...SEAS NEAR 5 FT MAY LINGER AT TIMES TUE AND WED OVER THE WATERS S AND E OF NANTUCKET. OTHERWISE WINDS AND SEAS SHOULD BE BELOW SMALL CRAFT ADVISORY CRITERIA. A NORTHEAST WIND GRADIENT WILL INCREASE OVER THE SOUTHERN COASTAL WATERS TUE NIGHT INTO WED AS STRONG HIGH PRESSURE PUSHES INTO NORTHERN NEW ENGLAND. BUT GUSTS ARE EXPECTED TO ONLY REACH 20 KT. WED NIGHT THROUGH FRI...QUIET BOATING WEATHER WITH HIGH PRESSURE DOMINATING THE WEATHER. WINDS AND SEAS BELOW SCA THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...HIGH SURF ADVISORY FROM 8 AM TO 5 PM EDT MONDAY FOR MAZ020>024. DENSE FOG ADVISORY UNTIL 5 AM EDT MONDAY FOR MAZ006-007-014. NH...NONE. RI...HIGH SURF ADVISORY FROM 8 AM TO 5 PM EDT MONDAY FOR RIZ006>008. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR ANZ250-254>256. SMALL CRAFT ADVISORY FROM 6 AM TO 4 PM EDT MONDAY FOR ANZ251. && $$ SYNOPSIS...FRANK/GAF NEAR TERM...FRANK/DOODY/GAF SHORT TERM...FRANK LONG TERM...GAF AVIATION...FRANK/GAF MARINE...FRANK/GAF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
707 PM EDT SUN SEP 21 2014 .SYNOPSIS... A PERIOD OF STEADY RAIN WILL AFFECT THE FAR SOUTHEAST NEW ENGLAND COAST THIS EVENING. OTHERWISE...DRIER AND LESS HUMID WEATHER IS ON TAP FOR MONDAY AS A DRY COLD FRONT SWEEPS ACROSS THE REGION. STRONG HIGH PRESSURE WILL BRING SUNNY DAYS AND CLEAR NIGHTS TO THE REGION FROM TUESDAY THROUGH NEXT WEEKEND WITH A WARMING TREND. WE COULD APPROACH RECORD WARMTH ON SATURDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... ***A PERIOD OF STEADY RAIN THIS EVENING ACROSS THE SOUTHEAST NEW ENGLAND COAST*** 7 PM UPDATE...SCATTERED DIURNAL-INDUCED SHOWERS HAVE BEGUN TO DISSIPATE OVER THE INTERIOR WITH SUNDOWN. A FEW HEAVY SHOWERS WERE STILL IN BOSTON/S SOUTH SHORE HEADING NORTH. AREA OF STEADY RAIN CONTINUES OVER THE ISLANDS. AREAS OF LOCALLY DENSE FOG HAD FORMED...AT MARSHFIELD AND FALMOUTH IN SOUTHEAST MA. WILL NEED TO KEEP A CLOSE EYE ON THIS TO SEE IF IT BECOMES MORE WIDESPREAD. IF SO...A DENSE FOG ADVISORY MAY BE NEEDED. OTHERWISE VERY MUGGY AIRMASS CONTINUES. LITTLE CHANGE TO TEMPERATURES OR POPS AT THIS UPDATE. PREVIOUS DISCUSSION... MARGINAL INSTABILITY WITH DEEP LOW LEVEL MOISTURE HAS ALLOWED ISOLATED TO SCATTERED SHOWERS TO CONTINUED TO AFFECT SOUTHERN NEW ENGLAND. WE SHOULD SEE THIS ACTIVITY DIMINISH EARLY THIS EVENING WITH THE LOSS OF DAYTIME HEATING. THE MAIN CONCERN WILL BE THE SURFACE LOW PRESSURE SYSTEM OFF THE MID ATLANTIC COAST WHICH WILL BE TRACKING NORTHEAST AND PASSING NEAR THE BENCHMARK THIS EVENING. THE MAIN QUESTION IS HOW FAR NORTHWEST THE RAIN SHIELD WILL GET. LATEST NEAR TERM GUIDANCE HAS BEEN TRENDING FURTHER NORTHWEST. THEREFORE...EXPECT A PERIOD OF STEADY RAIN ACROSS THE CAPE/ISLANDS AND PROBABLY FURTHER NORTHWEST INTO INTERIOR SOUTHEAST MA/RHODE ISLAND FOR AT LEAST A TIME. IN FACT...LATEST HRRR SHOWING THE POTENTIAL FOR A BRIEF PERIOD OF RAIN ACROSS THE NORTHEAST MA COAST INCLUDING BOSTON. NOT SURE IF IT WILL GET THAT FAR NORTHWEST...BUT ITS CERTAINLY POSSIBLE. REGARDLESS...THE HEAVIEST RAINFALL WILL OCCUR ACROSS NANTUCKET... WHERE BETWEEN 0.50 TO PERHAPS UP TO 1 INCH OF RAIN MAY OCCUR. THE RAIN MAY PERSIST THROUGH MUCH OF THE EVENING ACROSS THE CAPE AND ISLANDS...BUT SHOULD WIND DOWN NEAR OR JUST AFTER MIDNIGHT. MEANWHILE...ONCE THE ISOLATED TO SCATTERED DIURNALLY DRIVEN SCATTERED SHOWERS WIND DOWN EARLY THIS EVENING...THE REST OF THE REGION WILL MAINLY BE DRY TONIGHT. HOWEVER...A COLD FRONT WILL BE APPROACHING OUR WESTERN ZONES TOWARD MIDNIGHT. WHILE SHEAR IS QUITE IMPRESSIVE...VERY LITTLE INSTABILITY WILL BE LEFT. SO WHILE WE MAY SEE A FEW SPOT SHOWERS AFFECT OUR WESTERN ZONES...THEY WILL BE IN THE PROCESS OF WEAKENING AND NOT EXPECTING MUCH MORE THAN THAT. LOW TEMPS WILL ONLY BOTTOM OUT IN THE UPPER 50S AND THE LOWER 60S BY DAYBREAK MONDAY. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... MONDAY... A MUCH DRIER AIRMASS WILL WORK INTO THE REGION BEHIND THE COLD FRONT ON MONDAY. WHILE PARTLY TO MOSTLY SUNNY SKIES ARE EXPECTED EARLY...MAY SEE A SCATTERED TO BROKEN DECK OF STRATO- CUMULUS CLOUDS WORK INTO AT LEAST THE INTERIOR BY AFTERNOON. HIGHS SHOULD MAINLY BE IN THE 60S ACROSS THE INTERIOR...BUT STILL WILL REACH BETWEEN 70 AND 75 ALONG HE COASTAL PLAIN. GUSTY WEST WINDS OF 20 TO 30 MPH ARE EXPECTED AS BUFKIT SOUNDINGS SHOWING VERY GOOD MIXING. HIGH SURF...GIVEN LARGE SOUTH TO SOUTHEAST SWELL FROM DEPARTING COASTAL LOW PRESSURE SYSTEM HAVE ISSUED A HIGH SURF ADVISORY FOR THE SOUTH COAST ON MONDAY. WE ISSUE HIGH SURF PRODUCTS THROUGH THE END OF SEPTEMBER IF CONDITIONS WARRANT. MONDAY NIGHT... HIGH PRESSURE WILL BE BUILDING IN FROM THE WEST. THIS WILL ALLOW FOR DIMINISHING WINDS AND SKIES TO BECOME MOSTLY CLEAR. LOOKS LIKE A PRETTY GOOD NIGHT OF RADIATIONAL COOLING...WITH LOWS BOTTOMING OUT IN THE UPPER 30S TO THE MIDDLE 40S IN MOST LOCALES. THE URBAN HEAT ISLAND OF BOSTON WILL BE THE MILD SPOT WITH THE LOW BOTTOMING OUT NEAR 50. && .LONG TERM /TUESDAY THROUGH SUNDAY/... HIGHLIGHTS... * HIGH PRESSURE AND DRY WEATHER THROUGH THE PERIOD * NEAR RECORD WARMTH POSSIBLE NEXT SATURDAY OVERVIEW... VERY GOOD AGREEMENT AMONGST MODEL GUIDANCE THE ENTIRE FORECAST PERIOD. AN UPPER LEVEL TROUGH DEPARTS THE NORTHEAST STATES ON TUESDAY. THEN...MUCH ADO ABOUT BUILDING HIGH PRESSURE...BOTH AT THE SURFACE AND ALOFT THE REMAINDER OF THE WEEK. THE UPPER RIDGE IS VERY STRONG AS IT IS PARKED FROM THE GREAT LAKES TO SOUTHERN NEW ENGLAND BY NEXT WEEKEND. DETAILS... TUESDAY WILL FEATURE MOSTLY SUNNY SKIES EXCEPT ONLY PARTLY SUNNY NW MA AND SW NH CLOSER TO SOME HIGHER 925 MB HUMIDITY. OTHERWISE...EXPECT SUNNY DAYS AND CLEAR NIGHTS THROUGH NEXT WEEKEND. HAVE GONE A FEW DEGREES LOWER THAN MODEL CONSENSUS TEMPERATURE MINIMUMS THROUGH THU DUE TO EXCELLENT RADIATIONAL COOLING EXPECTED ALONG WITH VERY DRY DEWPOINTS. AS THE CENTER OF THE UPPER HIGH APPROACHES...AM EXPECTING A DRAMATIC WARMUP FRI AND ESPECIALLY SAT. THE 12Z ECMWF RUN IS EVEN WARMER THAN THE PREVIOUS RUN WITH 925 MB TEMPERATURES WARMING FROM +12C TUE...TO +17C FRI... TO +19C OR +20C ON SAT... WITH WARM TEMPERATURES LIKELY CONTINUING INTO EARLY THE FOLLOWING WEEK. HAVE GONE SEVERAL DEGREES ABOVE MODEL CONSENSUS MAXIMUMS FOR NEXT SATURDAY...WITH HIGHS SOARING TO 80 TO 85 ACROSS INTERIOR SOUTHERN NEW ENGLAND. RECORDS FOR THAT DAY INCLUDE 85 AT WORCESTER AND 86 AT BOTH BOSTON AND PROVIDENCE. LIGHT WINDS ARE EXPECTED FOR THE PERIOD...SO ALTHOUGH IT WILL BE DRY WE ARE NOT EXPECTING FIRE WEATHER CONCERNS. LOCAL SEA BREEZES WILL OCCUR...ESPECIALLY FRI THROUGH NEXT SUNDAY. IT SHOULD BE NOTED THAT THE GFS HAS A HINT OF A POTENTIAL BACKDOOR FRONT/TROUGH OVER NORTHEAST MA ON SAT BUT THIS WAS NOT ENOUGH TO DETRACT FROM THE VERY WARM FORECAST...AS YET. AN UPPER LOW OVER VIRGINIA AND AN ASSOCIATED INVERTED TROUGH IS LIKELY TO BE CAUSING PRECIPITATION IN THE MID ATLANTIC REGION MID TO LATE IN THE WORK WEEK THAT TRIES TO WORK ITS WAY NORTHWARD. THERE IS EXCELLENT MODEL AGREEMENT THAT THIS AREA ONLY GETS AS FAR NORTHWARD AS OFF THE NJ COAST BY FRI...BEFORE RETREATING SOUTHWARD AS STRONG HIGH PRESSURE BECOMES ESTABLISHED OVER THE NORTHEAST ON THE WEEKEND. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY NIGHT/... TONIGHT...LOW TO MODERATE CONFIDENCE. IFR CONDITIONS WITH SOME LOW IFR CONDITIONS ACROSS FAR SOUTHEAST MA INCLUDING THE CAPE AND ISLANDS WITH VISIBILITIES BELOW 1/2 MILE AT TIMES IN LOCALLY DENSE FOG. MOST OF THE REST OF THE REGION WILL BE MVFR CEILINGS...WITH MANY AREAS BECOMING IFR CEILINGS BETWEEN 02Z AND 06Z. BEST CONFIDENCE FOR IFR IS FROM ABOUT A JAFFREY-WORCESTER-WILLIMANTIC LINE EASTWARD. STEADY RAIN WITH EMBEDDED SHOWERS WILL AFFECT THE FAR SOUTHEAST NEW ENGLAND COAST THIS EVENING. THE RAIN WILL LIKELY REACH INTO RHODE ISLAND/INTERIOR SOUTHEAST MA FOR A SHORT TIME AND PERHAPS EVEN INTO NORTHEAST MA. MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE IN VFR CONDITIONS. JUST A LOW RISK FOR BRIEF MVFR CIGS ACROSS THE INTERIOR ON MONDAY AS A DECK OF STRATOCUMULUS CLOUDS MOVES INTO THE REGION. OTHERWISE...GUSTY WEST TO NORTHWEST WINDS OF 20 TO 25 KNOTS EXPECTED DURING THE DAY MONDAY. KBOS TERMINAL...MODERATE CONFIDENCE TONIGHT WITH HIGH CONFIDENCE ON MONDAY. KBDL TERMINAL...MODERATE CONFIDENCE TONIGHT WITH HIGH CONFIDENCE ON MONDAY. OUTLOOK...TUESDAY THROUGH FRIDAY... HIGH CONFIDENCE. TUE...VFR. WED...VFR THU...VFR. FRI...VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... TONIGHT...MODERATE TO HIGH CONFIDENCE. LOW PRESSURE PASSING NEAR THE BENCHMARK WILL RESULT IN ENOUGH SOUTH TO SOUTHEAST SWELL FOR SCA SEAS TO DEVELOP ACROSS THE OUTER-WATERS AND WESTERN SOUNDS. SOUTHEAST WINDS SHOULD BECOME SOUTHWEST TONIGHT AT 10 TO 15 KNOTS LATER TONIGHT. AREAS OF FOG...SOME LOCALLY DENSE...WILL OCCUR ACROSS THE WATERS...ESPECIALLY SOUTH OF BOSTON HARBOR. MONDAY AND MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. SCA SEAS ON THE WESTERN SOUNDS AND OUTER-WATERS WILL CONTINUE THROUGH MONDAY NIGHT. IN ADDITION...A PERIOD OF WEST TO NORTHWEST WIND GUSTS NEAR 25 KNOTS IS POSSIBLE FOR A TIME ON MONDAY. THEREFORE...IT IS POSSIBLE WE MAY NEED TO EXPAND SCA FOR A TIME DURING THE DAY MONDAY INTO SOME OF THE NEARSHORE SOUNDS AND WATERS. CONFIDENCE NOT QUITE HIGH ENOUGH TO DO THIS RIGHT NOW... SO WILL DEFER TO THE NEXT SHIFT. OUTLOOK...TUESDAY THROUGH FRIDAY... HIGH CONFIDENCE... TUE AND WED...SEAS NEAR 5 FT MAY LINGER AT TIMES TUE AND WED OVER THE WATERS S AND E OF NANTUCKET. OTHERWISE WINDS AND SEAS SHOULD BE BELOW SMALL CRAFT ADVISORY CRITERIA. A NORTHEAST WIND GRADIENT WILL INCREASE OVER THE SOUTHERN COASTAL WATERS TUE NIGHT INTO WED AS STRONG HIGH PRESSURE PUSHES INTO NORTHERN NEW ENGLAND. BUT GUSTS ARE EXPECTED TO ONLY REACH 20 KT. WED NIGHT THROUGH FRI...QUIET BOATING WEATHER WITH HIGH PRESSURE DOMINATING THE WEATHER. WINDS AND SEAS BELOW SCA THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...HIGH SURF ADVISORY FROM 8 AM TO 5 PM EDT MONDAY FOR MAZ020>024. NH...NONE. RI...HIGH SURF ADVISORY FROM 8 AM TO 5 PM EDT MONDAY FOR RIZ006>008. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR ANZ250-254>256. SMALL CRAFT ADVISORY FROM 6 AM TO 4 PM EDT MONDAY FOR ANZ251. && $$ SYNOPSIS...FRANK/FIELD NEAR TERM...FIELD/FRANK SHORT TERM...FRANK LONG TERM...FIELD AVIATION...FIELD/FRANK MARINE...FIELD/FRANK
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
914 PM EDT SUN SEP 21 2014 .SYNOPSIS... LOW PRESSURE OFF THE MID-ATLANTIC COAST WILL MOVE NORTHEASTWARD AND AWAY FROM THE REGION THROUGH TONIGHT. MEANWHILE, A COLD FRONT OVER THE OHIO VALLEY THIS AFTERNOON WILL MOVE THROUGH OUR AREA TONIGHT. A LARGE AREA OF HIGH PRESSURE BUILDS IN FROM THE MIDWEST EARLY IN THE WEEK. THE HIGH IS EXPECTED TO PARK OVER THE NORTHEAST STATES THROUGH THE REMAINDER OF THE WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... A CDFNT WAS APPROACHING FROM THE W AN A BROKEN AREA OF SHWRS WITH A FEW EMBEDDED LIGHTNING STRIKES WAS EVIDENT ON RADAR. IT APPEARS TO BE HOLDING TOGETHER AT IT MOVES EWD. THE HRRR INDICATES AT LEAST SOME PORTION OF THE PRECIP WILL SURVIVE INTO THE ERN PORTIONS OF OUR CWA. SO HAVE UPPED THE POPS INTO NJ, BUT NOT ALL THE WAY TO THE CST JUST YET. STILL THINK WITH LOSS OF DAYTIME HEATING AND NOT MUCH DYNAMICS TO WORK WITH THERE COULD BE SOME WEAKENING WITH TIME. WINDS WILL SHIFT TO WRLY/NWRLY BEHIND THE FRONT. DRIER AIR WILL OVERSPREAD THE AREA BY MORNING. LOWS WILL DIP INTO THE LOW.MID 50S NORTH/WEST TO THE UPPER 50S/LOW 60S SOUTH/EAST. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... A PLEASANT FALL-LIKE DAY IS EXPECTED ACROSS THE REGION MONDAY AS COOL AND DRIER AIR CONTINUES TO BUILD OVER THE AREA. A GUSTY W/NW WIND WILL BE IN PLACE EARLY AND CONTINUE THROUGH THE AFTERNOON. WINDS GUSTS OF 20 TO 25 MPH ARE EXPECTED. HIGH TEMPERATURES MONDAY WILL BE MOSTLY IN THE UPPER 60S/LOW 70S ACROSS THE AREA...WITH THE NRN MOST AREAS ONLY HAVING HIGHS IN THE UPPER 50S (MOUNT POCONO) TO THE MID 60S. DEW POINTS MOSTLY IN THE LOW/MID 40S. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... EXPANSIVE AREA OF HIGH PRESSURE OVER THE MIDWEST WILL BUILD EASTWARD INTO MID-ATLANTIC REGION STATES MONDAY NIGHT AND TUESDAY. MEANWHILE, A SOUTHERN PIECE OF ENERGY ASSOCIATED WITH THE UPPER LOW THAT IS CURRENTLY OVER THE GREAT LAKES REGION IS FORECAST TO LAG BEHIND THE MAIN UPPER TROUGH AND POTENTIALLY DEVELOP INTO A CLOSED LOW OVER THE SOUTHEAST STATES. A CAA REGIME WILL BECOME ESTABLISHED OVER OUR REGION DURING THIS TIME UNDER NORTHWEST FLOW. MINIMAL CLOUD COVER AND BELOW NORMAL TEMPS ARE EXPECTED. TEMPS MONDAY NIGHT MAY DIP INTO THE UPPER 30S IN THE POCONOS BUT THE NW WINDS OVERNIGHT SHOULD PRECLUDE ANY FROST FROM FORMING. WITH H8 TEMPS IN THE SINGLE DIGITS, MAX TEMPS ON TUESDAY WILL STRUGGLE TO REACH 70F. HIGH PRESSURE WILL RETREAT NORTHEASTWARD INTO NEW ENGLAND TUESDAY NIGHT AND REMAIN ANCHORED THERE THROUGH THE END OF THE WEEK. FORECAST UNCERTAINTY DECREASES DURING THE SECOND HALF OF THE WEEK AS MODELS HAVE HAD A DIFFICULT TIME COMING TO AGREEMENT REGARDING WHAT HAPPENS WITH THE ABOVE MENTIONED DISTURBANCE OVER THE SOUTHEAST STATES. OVER THE PAST FEW DAYS, THE ECMWF AND GEM CONTINUE TO ADVERTISE A STRONGER DISTURBANCE DRIFTING UP THE MID-ATLANTIC COAST LATE IN THE WEEK, WHICH WOULD BRING RAIN TO SOUTHERN PORTIONS OF THE AREA THURSDAY AND POSSIBLY INTO FRIDAY. MEANWHILE, THE OPERATIONAL GFS AND JUST ABOUT ALL OF ITS GEFS MEMBERS (INCLUDING THE LATEST 12Z RUN) HAS BEEN PERSISTENT IN SUPPRESSING THE DISTURBANCE FAR ENOUGH TO THE SOUTH AND EAST TO KEEP US DRY. THIS HAS A LOW PREDICTABILITY PATTERN WRITTEN ALL OVER IT GIVEN THE WEAK STEERING FLOW THE LOW WILL ENCOUNTER UNDERNEATH THE UPPER RIDGE. OPTED TO CLOSELY FOLLOW THE LATEST WPC GUIDANCE, WHICH PREFERRED AN IN-BETWEEN SCENARIO USING THE 00Z ECMWF ENSEMBLE MEAN. FORECAST WAS RATHER CONSERVATIVE WITH SLIGHT CHANCE POPS CONFINED TO THE DELMARVA AND SOUTHERN NJ. REGARDLESS OF WHICH SOLUTION PANS OUT, THE SETUP OF HIGH PRESSURE TO OUR NORTHEAST AND LOW PRESSURE TO OUR SOUTH WILL RESULT IN PERSISTENT FLOW OFF THE ATLANTIC OCEAN, SEASONABLY COOL TEMPS AND INCREASING CLOUD COVER. THE COASTAL DISTURBANCE IS FORECAST TO MOVE OFFSHORE BY THE WEEKEND WHILE HIGH PRESSURE BUILDS BACK INTO THE AREA. STRENGTHENING SUBSIDENCE FROM THE HIGH OVERHEAD WOULD YIELD A WARMING TREND WITH HIGHS POTENTIALLY NEAR 80F BOTH DAYS THIS WEEKEND. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDS ARE GENLY EXPECTED. HOWEVER, THERE IS A BKN LINE OF SHWRS MOVG ACRS ERN PA ATTM. THIS LINE COULD BRIEFLY DROP CIGS/VSBYS INTO THE MVFR OR EVEN IFR RANGE. STILL SOME UNCERTAINTY AS TO HOW FAR E THIS PRECIP WILL GET. HAVE ADDED SOME BRIEF SHRA/MVFR AT KPHL...KPNE AND KTTN. BEHIND THE FRONT WINDS WILL SHIFT TO WRLY/NWRLY AND SKIES WILL BECOME MOSTLY CLR. MON...VFR WITH A GUSTY WNW WIND THRU THE DAY. OUTLOOK... MONDAY NIGHT THROUGH TUESDAY NIGHT...VFR UNDER MAINLY SKC AND LIGHT NORTHWEST WINDS. WEDNESDAY AND WEDNESDAY NIGHT...ONSHORE FLOW DEVELOPS. EXPECT STRATOCU TO INCREASE AS MARINE LAYER DRAWS INLAND. SOME POTENTIAL FOR MVFR CIGS ESPECIALLY CLOSER TO THE COAST. THURSDAY AND FRIDAY...LOWER THAN NORMAL FORECAST CONFIDENCE AS LOPRES OVER THE SOUTHEAST STATES DRIFTS NORTHWARD. SUB-VFR CONDITIONS AND LIGHT RA COULD OCCUR (PARTICULARLY SOUTHERN TERMINALS) IF THE LOW TRACKS FAR ENOUGH NORTH, WHICH IS STILL UNCERTAIN ATTM. && .MARINE... WINDS ARE BEGINNING TO SWITCH AROUND TO NW BEHIND THE DEPARTING LOW OFFSHORE. THE WINDS WILL REMAIN MOSTLY AROUND 10 KTS AND THEN SWITCH MORE SWRLY THIS EVENING...BEFORE A COLD FRONT CROSSES THE WATERS OVERNIGHT. WINDS BEHIND THE FRONT WILL SHIFT WRLY...THEN NWRLY AND INCREASE TO 10 TO 20 KTS WITH SOME GUSTS AROUND 25 KTS. SEAS ON THE OCEAN WILL BUILD TO AROUND 5 FT OVERNIGHT. WE HAVE ISSUED A SCA FLAG FOR THE OCEAN WATERS AND LOWER DEL BAY TO COVER THE EXPECTED CONDITIONS. WINDS/SEAS WILL BEGIN TO SUBSIDE BY AROUND NOON MONDAY...SO WE WILL SET THE EXPIRATION TIME TO THAT FOR NOW...ITS POSSIBLE IT MAY NEED TO BE EXTENDED A FEW HOURS HOWEVER. OUTLOOK... MONDAY NIGHT...BREEZY NW FLOW CONTINUES AS HIPRES BUILDS INTO THE WATERS. CAPPED WINDS AROUND 20 KT, BUT STILL SOME POTENTIAL FOR A SCA IF THE PRESSURE GRADIENT WINDS UP BEING A TAD STRONGER THAN INDICATED BY THE LATEST GUIDANCE. TUESDAY AND TUESDAY NIGHT...NW WINDS DIMINISH TUESDAY BEFORE SHIFTING OUT OF THE NE TUESDAY NIGHT. WEDNESDAY AND WEDNESDAY NIGHT...NE WINDS STRENGTHEN TO NEAR SCA CRITERIA ON WEDNESDAY. IN RESPONSE TO THE FLOW, SEAS ARE FORECAST TO BUILD TO AROUND 5 FT BY WEDNESDAY NIGHT. THURSDAY THROUGH FRIDAY...FOUR TO SIX FT SEAS MAY CONTINUE THRU THURSDAY NIGHT OR FRIDAY DESPITE A WEAKER ONSHORE FLOW. SCA MAY BE NEEDED. && .RIP CURRENTS... A MODERATE RISK OF RIP CURRENTS IS BEING FORECAST FOR MONDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON EDT MONDAY FOR ANZ431-450>455. && $$ SYNOPSIS...KLEIN NEAR TERM...NIERENBERG/O`HARA SHORT TERM...O`HARA LONG TERM...KLEIN AVIATION...KLEIN/NIERENBERG/O`HARA MARINE...KLEIN/O`HARA
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
845 PM EDT SUN SEP 21 2014 .UPDATE... THE SHOWERS AND THUNDERSTORMS THAT BEEN OCCURRING OVER MOST OF SOUTH FLORIDA THIS AFTERNOON HAVE MOSTLY DISSIPATED THIS EVENING...EXCEPT OVER NORTHERN METRO MIAMI-DADE AND BROWARD COUNTIES. THIS ACTIVITY SHOULD CONTINUE TO DISSIPATE DURING NEXT COUPLE OF HOURS HAS THE HEATING OF THE DAY IS LOST. THEREFORE...WILL KEEP A SLIGHT CHANCE OF POPS OVER METRO BROWARD AND MIAMI-DADE COUNTIES THIS EVENING WHILE REST OF SOUTH FLORIDA REMAINS DRY. THE WEATHER SHOULD THEN BE DRY FOR THE LATE NIGHT HOURS TONIGHT OVER SOUTH FLORIDA. A STATIONARY FRONT WILL ALSO REMAIN OVER CENTRAL FLORIDA TONIGHT ALLOWING FOR A LIGHT SOUTHWEST WIND FLOW OVER SOUTH FLORIDA. THIS LIGHT SOUTHWEST WIND FLOW WILL KEEP THE TROPICAL MOISTURE IN PLACE OVER SOUTH FLORIDA TONIGHT WHICH COULD LEAD TO SOME PATCHY FOG OVER THE INTERIOR AREAS LATE. THEREFORE...PATCHY FOG HAS BEEN ADDED TO THE FORECAST FOR THE INTERIOR AREAS FOR THE LATE NIGHT HOURS TONIGHT. REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES ARE PLANNED. && .AVIATION... THE SHOWERS AND THUNDERSTORMS SHOULD COME TO AN END AROUND 1Z TONIGHT OVER THE EAST COAST TAF SITES AS THE HEATING OF THE DAY IS LOST. SO WILL KEEP VCTS IN UNTIL 1Z FOR THEN GO DRY FOR REST OF TONIGHT FOR THE EAST COAST TAF SITES. THE WINDS WILL ALSO BE LIGHT AND VARIABLE TONIGHT OVER THE EAST COAST TAF SITES. THE WINDS WILL REMAIN LIGHT AND VARIABLE UNTIL AROUND 15 TO 16Z ON MONDAY BEFORE BECOMING SOUTHEAST AROUND 5 TO 10 KNOTS...AS THE EAST COAST SEA BREEZE DEVELOPS AND PUSHES INLAND. THE WEATHER WILL ALSO REMAIN DRY UNTIL 15/16Z THEN VCTS HAS BEEN ADDED TO THE EAST COAST TAF SITES. FOR KAPF TAF SITE...THE WINDS WILL REMAIN LIGHT AND VARIABLE TONIGHT ALONG WITH DRY CONDITIONS. THE WINDS WILL THEN BECOME WESTERLY AFTER 17Z ON MONDAY...AS THE WEST COAST SEA BREEZE DEVELOPS AND PUSHES INLAND. THERE WILL ALSO BE A CHANCE OF THUNDERSTORMS AT KAPF TAF SITE AFTER 17Z AND A VCTS HAS BEEN ADDED TO KAPF TAF SITE AFTER 17Z ON MONDAY. && .UPDATE...54/BNB .AVIATION...54/BNB .PREV DISCUSSION... /ISSUED 343 PM EDT SUN SEP 21 2014/ DISCUSSION... CIRRUS CLOUDS AND SPRINKLES MOVED BACK INTO THE SOUTHERN PORTION OF THE REGION THIS AFTERNOON...AND THIS HAS LIMITED DEVELOPMENT THERE. IN ADDITION...WITH THE LOW LEVEL DRYING...DEW POINTS FELL INTO THE UPPER 60S TO LOW 70S. FURTHER NORTHER...SCATTERED SHOWERS AND STORMS WERE DEVELOPING ACROSS THE LAKE REGION SOUTH OF THE BOUNDARY AND MOVING TOWARDS THE PALM BEACH METRO AREA. A WEAK EAST COAST SEA BREEZE HAS ALSO DEVELOPED...AND THIS MAY ENHANCE ACTIVITY FOR THE EAST COAST METRO AREAS MAINLY FROM BROWARD COUNTY NORTHWARD INTO THIS EVENING. SHOWERS/STORMS WILL DISSIPATE BEFORE MIDNIGHT ALONG THE EAST COAST...WITH MAINLY QUIET CONDITIONS OVERNIGHT. AN UPPER TROUGH OVER THE GREAT LAKES THIS AFTERNOON WILL DIG DOWN INTO THE SOUTHEAST ON MONDAY AND THEN BEGIN TO LIFT OUT MONDAY NIGHT INTO TUESDAY. CONDITIONS ON MONDAY WILL BE VERY SIMILAR TO TODAY WITH DEEP SOUTHWESTERLY FLOW ALOFT AND DEEP MOISTURE. HIGH CLOUDS ARE EXPECTED ONCE AGAIN ACROSS THE REGION...AND THIS COULD LIMIT INSTABILITY. HIGH PRESSURE WILL BUILD ACROSS THE EASTERN HALF OF THE NATION...WITH EASTERLY FLOW RETURNING TO SOUTH FLORIDA ON TUESDAY. A WEAK TROPICAL WAVE WILL PASS THROUGH THE CARIBBEAN...AND THE PRESSURE GRADIENT WILL STRENGTHEN TUESDAY NIGHT ACROSS THE ATLANTIC WATERS. SOUTHERLY FLOW ALOFT WILL TAP THIS DEEP MOISTURE ACROSS THE CARIBBEAN...AND A WET PATTERN WILL CONTINUE. COASTAL CONVERGENCE COMBINED WITH THE DEEP MOISTURE WILL LEAD TO NUMEROUS SHOWERS AND SOME STORMS FOR THE EAST COAST METRO AREAS IN THE LATE OVERNIGHT HOURS THROUGH THE LATE MORNING TUESDAY AND WEDNESDAY...AND THEN SPREAD TO THE GULF COAST BY EARLY AFTERNOON. SHOWER AND THUNDERSTORM CHANCES DECREASE SLIGHTLY FOR THE LATTER HALF OF THE WEEK AS UPPER RIDGING BEGINS TO TAKE HOLD ACROSS THE WESTERN ATLANTIC. THIS WILL ALSO BRING A RETURN TO A MORE GULF BREEZE ORIENTED SETUP WITH AFTERNOON CONVECTION ACROSS THE INTERIOR AND GULF COASTAL AREAS. BOTH THE GFS AND THE ECMWF THEN AGREE WITH SLIDING THIS RIDGE FURTHER WEST AND OVER THE FLORIDA PENINSULA FRIDAY AND INTO NEXT WEEKEND. AVIATION... ALTHOUGH VFR CONDITIONS SHOULD PREVAIL WITH LIGHT WINDS THROUGH THE BULK OF 24 HR TAF PERIOD...THE LATEST HRRR MODEL RUN REMAINS CONSISTENT AND CONTINUES TO INDICATE SCATTERED SHRAS/TSTMS DEVELOPING AND TRACKING EASTWARD OVER THE EAST COAST TAF SITES THROUGH THE AFTERNOON HOURS. WILL INCLUDE VCTS EXTENDING NORTH FROM FLL AND VCSH SOUTHWARD ACROSS OPF/TMB/MIA DUE TO THE EXTENSIVE MID/UPPER CLOUD COVERAGE THAT SHOULD CONTINUE TO LIMIT INSTABILITY THROUGH THE PEAK HEATING HOURS TODAY OVER THESE SOUTHERN SITES. 85/ MARINE... AN EASTERLY FLOW REGIME WILL THEN SET UP AND PREVAIL THROUGH THE UPCOMING WEEK AS HIGH PRESSURE RETURNS ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT 3 FEET OR LESS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 73 89 75 85 / 30 60 50 70 FORT LAUDERDALE 74 88 77 86 / 30 60 50 70 MIAMI 74 89 77 86 / 30 50 50 70 NAPLES 74 86 75 87 / 20 50 30 70 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...54/BNB LONG TERM....84/AK AVIATION...54/BNB
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
443 PM EDT SAT SEP 20 2014 .UPDATE... MOST OF THE SHOWERS AND THUNDERSTORMS THAT BEEN OCCURRING OVER THE EASTERN AREAS OF SOUTH FLORIDA HAVE PUSHED INTO THE ATLANTIC WATERS LATE THIS AFTERNOON. THE ONLY AREA THAT COULD STILL SEE SOME SHOWERS AND THUNDERSTORMS IS OVER MIAMI-DADE COUNTY AS THIS AREA HAS NOT BEEN WORK OVER YET TODAY. THEREFORE...THE POPS HAVE BEEN LOWERED OVER MOST OF SOUTH FLORIDA...EXCEPT FOR THE SOUTHEAST AREAS OF SOUTH FLORIDA WHERE SCATTERED POPS WILL REMAIN IN PLACE FOR THIS AFTERNOON. FOR THE ATLANTIC WATERS...THE POPS HAVE ALSO BEEN RAISED TO NUMEROUS COVERAGE FOR THE ON GOING SHOWER AND THUNDERSTORM ACTIVITY. REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES ARE PLANNED. && .UPDATED...54/BNB .PREV DISCUSSION... /ISSUED 326 PM EDT SAT SEP 20 2014/ DISCUSSION... THE SUN CAME OUT THIS AFTERNOON ACROSS THE SOUTHEASTERN PORTION OF THE REGION...AND TEMPERATURES WERE ABLE TO GET BRIEFLY INTO THE UPPER 80S TO AROUND 90 DEGREES. SHOWERS AND STORMS WERE BEGINNING TO FILL IN ACROSS THE EAST COAST METRO AREAS...AND NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED/SCATTERED STORMS WILL CONTINUE ACROSS SOUTH FLORIDA THROUGH THE AFTERNOON HOURS. THE MAIN THREAT THIS AFTERNOON WILL BE LOCALLY HEAVY RAINFALL AND ISOLATED STREET FLOODING FOR THE EAST COAST METROS. GUSTY WINDS UP TO 50 MPH ARE ALSO POSSIBLE. TONIGHT...SHOWERS AND STORMS WILL DIMINISH SLOWLY THIS EVENING WITH LOSS OF DAYTIME HEATING...BUT REDEVELOPMENT IS POSSIBLE OVERNIGHT FOR THE GULF WATERS THROUGH THE NAPLES REGION. THE AREA OF LOW PRESSURE OFF THE EAST COAST OF NORTH FLORIDA WILL MOVE NORTHEAST OVERNIGHT...BUT THE FRONTAL BOUNDARY ACROSS CENTRAL FLORIDA WILL REMAIN STATIONARY. SUNDAY AND MONDAY...DEEP MOISTURE WILL REMAIN ACROSS SOUTH FLORIDA TO THE SOUTH OF THE BOUNDARY ACROSS CENTRAL FLORIDA...WITH PWATS AROUND 2 INCHES. WEAK UPPER TROUGHING WILL ALSO CONTINUE ACROSS THE REGION. A FEW MID LEVEL IMPULSES SLIGHTLY DETACHED FROM THE PARENT 500MB SHORTWAVE WELL TO THE NORTH ARE EXPECTED TO SLIDE TO THE NORTHEAST ACROSS THE NORTHERN INTERIOR. THIS SHOULD ENHANCE THUNDERSTORM DEVELOPMENT OVER THE AREA FOR THROUGH THE BEGINNING OF NEXT WEEK. NUMEROUS SHOWERS AND STORMS ARE EXPECTED EACH AFTERNOON. A MORE EASTERLY FLOW PATTERN RETURNS TUESDAY AND SHOULD PERSIST THROUGH THE REMAINDER OF THE WEEK AS MID LEVEL RIDGING BECOMES FIRMLY ENTRENCHED ACROSS THE WESTERN ATLANTIC. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PREVAIL EACH DAY WITH MODELS DEPICTING THE DEEP MOISTURE AXIS REMAINING ACROSS SOUTH FLORIDA. MODEL SOUNDINGS DEPICT PWAT VALUES RANGING BETWEEN 1.75-2.00 INCHES THROUGH THE REMAINDER OF THE WEEK. THE DEEP MOISTURE AND RESULTANT CLOUD COVER ALONG WITH AN OVERALL LACK OF DYNAMICS SHOULD KEEP THE STRONG TO SEVERE THUNDERSTORM POTENTIAL LIMITED. AVIATION... SCATTERED SHOWERS AND STORMS ASSOCIATED WITH A FRONTAL BOUNDARY AND UPPER TROUGH WILL CONTINUE TO DEVELOP AND INCREASE IN COVERAGE ACROSS THE AREA THROUGH THE AFTERNOON HOURS. WSW FLOW WILL FOCUS THE HEAVIEST ACTIVITY TOWARD THE EAST COAST SITES THROUGH THIS TIME TODAY. THE FLOW SHOULD PROVE TO BE TOO STRONG FOR THE EAST COAST SEA BREEZE TO SET UP...WHICH IS REFLECTED WELL IN THE LATEST HRRR RUN THAT INDICATES THE ACTIVITY PUSHING THROUGH AND OFF THE COAST THROUGH THE EARLY EVENING PERIOD. VFR CONDITIONS SHOULD RETURN THROUGH THE LATE EVENING AND OVERNIGHT HOURS WITH LIGHT WESTERLY FLOW CONTINUING. 85/AG MARINE... GENERAL SOUTHWESTERLY WINDS AT AROUND 10 KNOTS OR LESS SHOULD PREVAIL THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEPARTS TO THE NORTHEAST. A MORE EASTERLY FLOW REGIME WILL THEN SET UP THROUGH THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE RETURNS ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT AROUND 3 FEET OR LESS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 73 88 75 86 / 40 50 20 60 FORT LAUDERDALE 75 88 78 87 / 40 60 20 60 MIAMI 74 88 77 87 / 40 60 20 60 NAPLES 75 87 75 86 / 50 50 20 60 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...54/BNB LONG TERM....85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
326 PM EDT SAT SEP 20 2014 .DISCUSSION... THE SUN CAME OUT THIS AFTERNOON ACROSS THE SOUTHEASTERN PORTION OF THE REGION...AND TEMPERATURES WERE ABLE TO GET BRIEFLY INTO THE UPPER 80S TO AROUND 90 DEGREES. SHOWERS AND STORMS WERE BEGINNING TO FILL IN ACROSS THE EAST COAST METRO AREAS...AND NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED/SCATTERED STORMS WILL CONTINUE ACROSS SOUTH FLORIDA THROUGH THE AFTERNOON HOURS. THE MAIN THREAT THIS AFTERNOON WILL BE LOCALLY HEAVY RAINFALL AND ISOLATED STREET FLOODING FOR THE EAST COAST METROS. GUSTY WINDS UP TO 50 MPH ARE ALSO POSSIBLE. TONIGHT...SHOWERS AND STORMS WILL DIMINISH SLOWLY THIS EVENING WITH LOSS OF DAYTIME HEATING...BUT REDEVELOPMENT IS POSSIBLE OVERNIGHT FOR THE GULF WATERS THROUGH THE NAPLES REGION. THE AREA OF LOW PRESSURE OFF THE EAST COAST OF NORTH FLORIDA WILL MOVE NORTHEAST OVERNIGHT...BUT THE FRONTAL BOUNDARY ACROSS CENTRAL FLORIDA WILL REMAIN STATIONARY. SUNDAY AND MONDAY...DEEP MOISTURE WILL REMAIN ACROSS SOUTH FLORIDA TO THE SOUTH OF THE BOUNDARY ACROSS CENTRAL FLORIDA...WITH PWATS AROUND 2 INCHES. WEAK UPPER TROUGHING WILL ALSO CONTINUE ACROSS THE REGION. A FEW MID LEVEL IMPULSES SLIGHTLY DETACHED FROM THE PARENT 500MB SHORTWAVE WELL TO THE NORTH ARE EXPECTED TO SLIDE TO THE NORTHEAST ACROSS THE NORTHERN INTERIOR. THIS SHOULD ENHANCE THUNDERSTORM DEVELOPMENT OVER THE AREA FOR THROUGH THE BEGINNING OF NEXT WEEK. NUMEROUS SHOWERS AND STORMS ARE EXPECTED EACH AFTERNOON. A MORE EASTERLY FLOW PATTERN RETURNS TUESDAY AND SHOULD PERSIST THROUGH THE REMAINDER OF THE WEEK AS MID LEVEL RIDGING BECOMES FIRMLY ENTRENCHED ACROSS THE WESTERN ATLANTIC. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PREVAIL EACH DAY WITH MODELS DEPICTING THE DEEP MOISTURE AXIS REMAINING ACROSS SOUTH FLORIDA. MODEL SOUNDINGS DEPICT PWAT VALUES RANGING BETWEEN 1.75-2.00 INCHES THROUGH THE REMAINDER OF THE WEEK. THE DEEP MOISTURE AND RESULTANT CLOUD COVER ALONG WITH AN OVERALL LACK OF DYNAMICS SHOULD KEEP THE STRONG TO SEVERE THUNDERSTORM POTENTIAL LIMITED. && .AVIATION... SCATTERED SHOWERS AND STORMS ASSOCIATED WITH A FRONTAL BOUNDARY AND UPPER TROUGH WILL CONTINUE TO DEVELOP AND INCREASE IN COVERAGE ACROSS THE AREA THROUGH THE AFTERNOON HOURS. WSW FLOW WILL FOCUS THE HEAVIEST ACTIVITY TOWARD THE EAST COAST SITES THROUGH THIS TIME TODAY. THE FLOW SHOULD PROVE TO BE TOO STRONG FOR THE EAST COAST SEA BREEZE TO SET UP...WHICH IS REFLECTED WELL IN THE LATEST HRRR RUN THAT INDICATES THE ACTIVITY PUSHING THROUGH AND OFF THE COAST THROUGH THE EARLY EVENING PERIOD. VFR CONDITIONS SHOULD RETURN THROUGH THE LATE EVENING AND OVERNIGHT HOURS WITH LIGHT WESTERLY FLOW CONTINUING. 85/AG && .MARINE... GENERAL SOUTHWESTERLY WINDS AT AROUND 10 KNOTS OR LESS SHOULD PREVAIL THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEPARTS TO THE NORTHEAST. A MORE EASTERLY FLOW REGIME WILL THEN SET UP THROUGH THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE RETURNS ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT AROUND 3 FEET OR LESS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 73 88 75 86 / 40 50 20 60 FORT LAUDERDALE 75 88 78 87 / 40 60 20 60 MIAMI 74 88 77 87 / 40 60 20 60 NAPLES 75 87 75 86 / 50 50 20 60 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...84/AK LONG TERM....84/AK AVIATION...85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
211 PM EDT SAT SEP 20 2014 .AVIATION... SCATTERED SHOWERS AND STORMS ASSOCIATED WITH A FRONTAL BOUNDARY AND UPPER TROUGH WILL CONTINUE TO DEVELOP AND INCREASE IN COVERAGE ACROSS THE AREA THROUGH THE AFTERNOON HOURS. WSW FLOW WILL FOCUS THE HEAVIEST ACTIVITY TOWARD THE EAST COAST SITES THROUGH THIS TIME TODAY. THE FLOW SHOULD PROVE TO BE TOO STRONG FOR THE EAST COAST SEA BREEZE TO SET UP...WHICH IS REFLECTED WELL IN THE LATEST HRRR RUN THAT INDICATES THE ACTIVITY PUSHING THROUGH AND OFF THE COAST THROUGH THE EARLY EVENING PERIOD. VFR CONDITIONS SHOULD RETURN THROUGH THE LATE EVENING AND OVERNIGHT HOURS WITH LIGHT WESTERLY FLOW CONTINUING. 85/AG && .PREV DISCUSSION... /ISSUED 1015 AM EDT SAT SEP 20 2014/ UPDATE... WET CONDITIONS EXPECTED AGAIN TODAY ACROSS SOUTH FLORIDA. LIGHT SHOWERS WERE MOVING ACROSS THE GULF AND THE LAKE REGION THIS MORNING. PWATS ON THE 12Z SOUNDING WERE JUST ABOVE 2 INCHES. AN AREA OF LOW PRESSURE OFF THE EAST COAST OF CENTRAL FLORIDA WILL DEEPEN AS IT MOVES NORTHEAST TODAY...WITH DEEP TRAILING MOISTURE REMAINING ACROSS SOUTH FLORIDA. LIFT IS EXPECTED TO INCREASE ACROSS THE LAKE REGION THROUGH THE DAY AS A SHORTWAVE ROTATES AROUND THE BASE OF THE UPPER LOW LOCATED ACROSS THE GEORGIA/FLORIDA BORDER. THE MAJOR LIMITING FACTOR THIS AFTERNOON WILL BE CLOUD COVER...ESPECIALLY ACROSS THE LAKE REGION. HOWEVER...WITH THE SYNOPTIC FEATURE ENHANCING LIFT...EXPECT WIDESPREAD SHOWERS AND A FEW STORMS ACROSS THE NAPLES AREA AND LAKE REGION. THE FIRST VISIBLE IMAGES THIS MORNING SHOW BREAKS IN THE CLOUDS ACROSS THE SOUTHERN PORTION OF THE REGION...AND THE DIFFERENTIAL HEATING MAY ALLOW FOR SHOWER AND STORM DEVELOPMENT ACROSS THE EAST AND SOUTHEAST COAST IN THE AFTERNOON. THE HRRR AND LOCAL WRF MODELS ARE HINTING AT THIS POSSIBILITY. SO KEPT THE LIKELY POPS IN FOR THE REST OF THE REGION AS WELL. TEMPERATURES WILL BE BELOW NORMAL ACROSS THE REGION DUE TO THE CLOUD COVER AND RAINFALL. PREV DISCUSSION... /ISSUED 855 AM EDT SAT SEP 20 2014/ AVIATION... DESPITE THE EXTENSIVE MORNING CLOUD COVERAGE...THE LATEST VISIBLE SATELLITE IMAGERY HAS ALREADY BEGUN TO INDICATE SOME OF THIS COVERAGE THINNING OR BREAKING UP. IF THIS TREND CONTINUES...DAYTIME HEATING COMBINED WITH AN UPPER TROUGH AND WEAK FRONTAL BOUNDARY WILL SUPPORT SHRAS/TSTMS ONCE AGAIN THIS AFTERNOON...POSSIBLY LATER DUE TO THE CURRENT CLOUD COVERAGE. WITH THE WSW LOW-LEVEL FLOW IN PLACE...ANY SHRA/TSTM DEVELOP SHOULD FOCUS TOWARD THE EAST COAST TODAY. 85/ PREV DISCUSSION... /ISSUED 418 AM EDT SAT SEP 20 2014/ DISCUSSION... A WET PATTERN TO CONTINUE THROUGH THE WEEKEND AND MUCH OF NEXT WEEK ACROSS SOUTH FLORIDA. SHOWERS ASSOCIATED WITH A WEAK SURFACE TROUGH CONTINUE TO DIMINISH WHILE PULLING TO THE NORTHEAST AND AWAY FROM SOUTH FLORIDA THIS MORNING. HOWEVER...MOSTLY CLOUDY SKIES SHOULD REMAIN ACROSS THE AREA THROUGH MUCH OF THE DAY AS A RESULT. CUTOFF H5 LOW AND ASSOCIATED SURFACE LOW PRESSURE ACROSS NORTHERN FLORIDA ARE EXPECTED TO SLOWLY PUSH TO THE NORTHEAST THROUGH THE DAY. CONCURRENTLY...DEEP MOISTURE WILL CONTINUE TO SURGE INTO THE AREA WITH MID LEVEL SOUTHWEST FLOW. THIS WILL PRODUCE PWAT VALUES OF AROUND 2 INCHES ACROSS THE AREA RESULTING IN ANOTHER DAY OF SHOWERS AND A FEW THUNDERSTORMS. THE BEST COVERAGE OF SHOWERS AND STORMS LOOKS TO BE ACROSS THE LAKE OKEECHOBEE AND PALM BEACH COUNTY AREAS WITH CLOSER PROXIMITY TO THE H5 SHORTWAVE THUS ENHANCING LIFT. CLOUD COVER THROUGH THE MORNING SHOULD GREATLY LIMIT STRONG THUNDERSTORM POTENTIAL THROUGH THE AFTERNOON. VIRTUALLY ALL CONVECTIVE PARAMETERS DECREASE THROUGH THE DAY AS A RESULT. COVERAGE OF SHOWERS AND STORMS SHOULD DECREASE AGAIN AFTER DARK WITH LIMITED ACTIVITY LINGERING MAINLY ACROSS THE AREA WATERS. DEEP SOUTHWEST FLOW ALOFT SHOULD CONTINUE SUNDAY INTO MONDAY KEEPING A DEEP MOISTURE AXIS ACROSS CENTRAL AND SOUTHERN FLORIDA. THIS WILL KEEP A RATHER WET PATTERN THROUGH THE END OF THE WEEKEND AND INTO THE START OF NEXT WEEK ACROSS THE AREA. A FEW MID LEVEL IMPULSES SLIGHTLY DETACHED FROM THE PARENT H5 SHORTWAVE WELL TO THE NORTH ARE EXPECTED TO SLIDE TO THE NORTHEAST ACROSS THE NORTHERN INTERIOR. THIS SHOULD ENHANCE THUNDERSTORM DEVELOPMENT SLIGHTLY OVER THE AREA FOR THE BEGINNING OF NEXT WEEK. A MORE EASTERLY FLOW PATTERN RETURNS TUESDAY AND SHOULD PERSIST THROUGH THE REMAINDER OF THE WEEK AS MID LEVEL RIDGING BECOMES FIRMLY ENTRENCHED ACROSS THE WESTERN ATLANTIC. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PREVAIL EACH DAY WITH MODELS DEPICTING THE DEEP MOISTURE AXIS REMAINING ACROSS SOUTH FLORIDA. MODEL SOUNDINGS DEPICT PWAT VALUES RANGING BETWEEN 1.75-2.00 INCHES THROUGH THE REMAINDER OF THE WEEK. THE DEEP MOISTURE AND RESULTANT CLOUD COVER ALONG WITH AN OVERALL LACK OF DYNAMICS SHOULD KEEP THE STRONG TO SEVERE THUNDERSTORM POTENTIAL LIMITED. AVIATION... A WEAK TROUGH OF LOW PRESSURE OVER FLORIDA WILL DEVELOP INTO A LOW PRESSURE SYSTEM LATER TODAY. THIS LOW WILL KEEP SHOWERS AND SOME THUNDERSTORMS OVER SOUTH FLORIDA THROUGH THE DAY. BY THIS EVENING, THE LOW WILL BE EXITING THE AREA AND TAKE MUCH OF THE PRECIPITATION ALONG WITH IT. FOR TODAY, EXPECTING MOSTLY RAIN SHOWERS IN THE MORNING AND INTO THE AFTERNOON. IN THE AFTERNOON, THE CHANCES OF THUNDERSTORMS WILL INCREASE. HAVE PLACED THE PROB30 GROUPS LATER IN THE DAY TO REFLECT THIS FOR THE EASTERN TAF SITES. OVERALL, MAINLY VFR/MVFR CONDITIONS ACROSS SOUTH FLORIDA, WITH BRIEF IFR POSSIBLE UNDER HEAVY SHOWERS AND/OR THUNDERSTORMS. MARINE... GENERAL SOUTHWESTERLY WINDS AT AROUND 10 KNOTS OR LESS SHOULD PREVAIL THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEPARTS TO THE NORTHEAST. A MORE EASTERLY FLOW REGIME WILL THEN SET UP THROUGH THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE RETURNS ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT AROUND 3 FEET OR LESS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 73 87 74 86 / 20 60 20 60 FORT LAUDERDALE 76 88 77 87 / 20 60 20 50 MIAMI 76 88 76 87 / 20 60 20 50 NAPLES 75 85 75 86 / 20 50 30 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....10/CD AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
1015 AM EDT SAT SEP 20 2014 .UPDATE... WET CONDITIONS EXPECTED AGAIN TODAY ACROSS SOUTH FLORIDA. LIGHT SHOWERS WERE MOVING ACROSS THE GULF AND THE LAKE REGION THIS MORNING. PWATS ON THE 12Z SOUNDING WERE JUST ABOVE 2 INCHES. AN AREA OF LOW PRESSURE OFF THE EAST COAST OF CENTRAL FLORIDA WILL DEEPEN AS IT MOVES NORTHEAST TODAY...WITH DEEP TRAILING MOISTURE REMAINING ACROSS SOUTH FLORIDA. LIFT IS EXPECTED TO INCREASE ACROSS THE LAKE REGION THROUGH THE DAY AS A SHORTWAVE ROTATES AROUND THE BASE OF THE UPPER LOW LOCATED ACROSS THE GEORGIA/FLORIDA BORDER. THE MAJOR LIMITING FACTOR THIS AFTERNOON WILL BE CLOUD COVER...ESPECIALLY ACROSS THE LAKE REGION. HOWEVER...WITH THE SYNOPTIC FEATURE ENHANCING LIFT...EXPECT WIDESPREAD SHOWERS AND A FEW STORMS ACROSS THE NAPLES AREA AND LAKE REGION. THE FIRST VISIBLE IMAGES THIS MORNING SHOW BREAKS IN THE CLOUDS ACROSS THE SOUTHERN PORTION OF THE REGION...AND THE DIFFERENTIAL HEATING MAY ALLOW FOR SHOWER AND STORM DEVELOPMENT ACROSS THE EAST AND SOUTHEAST COAST IN THE AFTERNOON. THE HRRR AND LOCAL WRF MODELS ARE HINTING AT THIS POSSIBILITY. SO KEPT THE LIKELY POPS IN FOR THE REST OF THE REGION AS WELL. TEMPERATURES WILL BE BELOW NORMAL ACROSS THE REGION DUE TO THE CLOUD COVER AND RAINFALL. && .PREV DISCUSSION... /ISSUED 855 AM EDT SAT SEP 20 2014/ AVIATION... DESPITE THE EXTENSIVE MORNING CLOUD COVERAGE...THE LATEST VISIBLE SATELLITE IMAGERY HAS ALREADY BEGUN TO INDICATE SOME OF THIS COVERAGE THINNING OR BREAKING UP. IF THIS TREND CONTINUES...DAYTIME HEATING COMBINED WITH AN UPPER TROUGH AND WEAK FRONTAL BOUNDARY WILL SUPPORT SHRAS/TSTMS ONCE AGAIN THIS AFTERNOON...POSSIBLY LATER DUE TO THE CURRENT CLOUD COVERAGE. WITH THE WSW LOW-LEVEL FLOW IN PLACE...ANY SHRA/TSTM DEVELOP SHOULD FOCUS TOWARD THE EAST COAST TODAY. 85/ PREV DISCUSSION... /ISSUED 418 AM EDT SAT SEP 20 2014/ DISCUSSION... A WET PATTERN TO CONTINUE THROUGH THE WEEKEND AND MUCH OF NEXT WEEK ACROSS SOUTH FLORIDA. SHOWERS ASSOCIATED WITH A WEAK SURFACE TROUGH CONTINUE TO DIMINISH WHILE PULLING TO THE NORTHEAST AND AWAY FROM SOUTH FLORIDA THIS MORNING. HOWEVER...MOSTLY CLOUDY SKIES SHOULD REMAIN ACROSS THE AREA THROUGH MUCH OF THE DAY AS A RESULT. CUTOFF H5 LOW AND ASSOCIATED SURFACE LOW PRESSURE ACROSS NORTHERN FLORIDA ARE EXPECTED TO SLOWLY PUSH TO THE NORTHEAST THROUGH THE DAY. CONCURRENTLY...DEEP MOISTURE WILL CONTINUE TO SURGE INTO THE AREA WITH MID LEVEL SOUTHWEST FLOW. THIS WILL PRODUCE PWAT VALUES OF AROUND 2 INCHES ACROSS THE AREA RESULTING IN ANOTHER DAY OF SHOWERS AND A FEW THUNDERSTORMS. THE BEST COVERAGE OF SHOWERS AND STORMS LOOKS TO BE ACROSS THE LAKE OKEECHOBEE AND PALM BEACH COUNTY AREAS WITH CLOSER PROXIMITY TO THE H5 SHORTWAVE THUS ENHANCING LIFT. CLOUD COVER THROUGH THE MORNING SHOULD GREATLY LIMIT STRONG THUNDERSTORM POTENTIAL THROUGH THE AFTERNOON. VIRTUALLY ALL CONVECTIVE PARAMETERS DECREASE THROUGH THE DAY AS A RESULT. COVERAGE OF SHOWERS AND STORMS SHOULD DECREASE AGAIN AFTER DARK WITH LIMITED ACTIVITY LINGERING MAINLY ACROSS THE AREA WATERS. DEEP SOUTHWEST FLOW ALOFT SHOULD CONTINUE SUNDAY INTO MONDAY KEEPING A DEEP MOISTURE AXIS ACROSS CENTRAL AND SOUTHERN FLORIDA. THIS WILL KEEP A RATHER WET PATTERN THROUGH THE END OF THE WEEKEND AND INTO THE START OF NEXT WEEK ACROSS THE AREA. A FEW MID LEVEL IMPULSES SLIGHTLY DETACHED FROM THE PARENT H5 SHORTWAVE WELL TO THE NORTH ARE EXPECTED TO SLIDE TO THE NORTHEAST ACROSS THE NORTHERN INTERIOR. THIS SHOULD ENHANCE THUNDERSTORM DEVELOPMENT SLIGHTLY OVER THE AREA FOR THE BEGINNING OF NEXT WEEK. A MORE EASTERLY FLOW PATTERN RETURNS TUESDAY AND SHOULD PERSIST THROUGH THE REMAINDER OF THE WEEK AS MID LEVEL RIDGING BECOMES FIRMLY ENTRENCHED ACROSS THE WESTERN ATLANTIC. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PREVAIL EACH DAY WITH MODELS DEPICTING THE DEEP MOISTURE AXIS REMAINING ACROSS SOUTH FLORIDA. MODEL SOUNDINGS DEPICT PWAT VALUES RANGING BETWEEN 1.75-2.00 INCHES THROUGH THE REMAINDER OF THE WEEK. THE DEEP MOISTURE AND RESULTANT CLOUD COVER ALONG WITH AN OVERALL LACK OF DYNAMICS SHOULD KEEP THE STRONG TO SEVERE THUNDERSTORM POTENTIAL LIMITED. AVIATION... A WEAK TROUGH OF LOW PRESSURE OVER FLORIDA WILL DEVELOP INTO A LOW PRESSURE SYSTEM LATER TODAY. THIS LOW WILL KEEP SHOWERS AND SOME THUNDERSTORMS OVER SOUTH FLORIDA THROUGH THE DAY. BY THIS EVENING, THE LOW WILL BE EXITING THE AREA AND TAKE MUCH OF THE PRECIPITATION ALONG WITH IT. FOR TODAY, EXPECTING MOSTLY RAIN SHOWERS IN THE MORNING AND INTO THE AFTERNOON. IN THE AFTERNOON, THE CHANCES OF THUNDERSTORMS WILL INCREASE. HAVE PLACED THE PROB30 GROUPS LATER IN THE DAY TO REFLECT THIS FOR THE EASTERN TAF SITES. OVERALL, MAINLY VFR/MVFR CONDITIONS ACROSS SOUTH FLORIDA, WITH BRIEF IFR POSSIBLE UNDER HEAVY SHOWERS AND/OR THUNDERSTORMS. MARINE... GENERAL SOUTHWESTERLY WINDS AT AROUND 10 KNOTS OR LESS SHOULD PREVAIL THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEPARTS TO THE NORTHEAST. A MORE EASTERLY FLOW REGIME WILL THEN SET UP THROUGH THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE RETURNS ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT AROUND 3 FEET OR LESS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 86 73 87 74 / 80 20 60 20 FORT LAUDERDALE 87 76 88 77 / 70 20 60 20 MIAMI 86 76 88 76 / 60 20 60 20 NAPLES 83 75 85 75 / 80 20 50 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...84/AK LONG TERM....84/AK
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1008 PM EDT SUN SEP 21 2014 .UPDATE... CONVECTION CONTINUES TO SLIDE SOUTHWARD ACROSS NORTH GEORGIA AND THERE IS SOME UNCERTAINTY IN HOW THE PRECIP WILL PLAY OUT LATE TONIGHT INTO MONDAY. OVERALL HAVE CHOSEN TO SHOW IT CONTINUING TO SINK SOUTHWARD...BUT DECREASE THE COVERAGE FROM SCATTERED TO ISOLATED OVERNIGHT. HRRR EXPANDS AREA OF PRECIP BY 14Z WHILE THE LOCAL WRF ISNT QUITE THAT BOLD. CONSIDERING HRRR HAS BEEN OVERDONE THIS SUMMER OVERALL...HAVE LEANED MORE TOWARDS THE LOCAL WRF. POP GRIDS MAY STILL BE A TAD UNDERDONE THOUGH FOR LATE TONIGHT INTO MONDAY. MADE A SLIGHT INCREASE IN POPS ACROSS THE FAR SOUTHEAST PART OF THE CWA FOR MONDAY AFTERNOON AS VORT MAX MAY HELP TO INCREASE CONVECTION. && .PREV DISCUSSION... SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... /ISSUED 317 PM EDT SUN SEP 21 2014/ COLD FRONT IS PUSHING INTO THE TENNESSEE VALLEY AT AFD TIME WITH ISOLATED SHOWERS DEVELOPING ALONG AND JUST AHEAD OF IT. CAPE VALUES ARE ON THE LOW END...GENERALLY BELOW 1500 J/KG ACROSS NORTH GEORGIA...AND BEST PVA IS ACTUALLY BEHIND THE FRONT AND DOES NOT PUSH INTO GEORGIA REALLY UNTIL MONDAY SOMETIME. SO HAVE KEPT TREND OF SLIGHT TO LOW CHANCE POPS WITH WORDING LIMITED TO ONLY SLIGHT CHANCE THUNDER...ESPECIALLY SINCE WHAT CAPE MIGHT BE AROUND THIS AFTERNOON QUICKLY DECREASES OVERNIGHT. DRY AIR STARTS FILTERING INTO NORTH GEORGIA BEHIND THE FRONT BUT NEW RUNS ARE A LITTLE SLOWER WITH THIS SO LOW TEMPS TONIGHT NOT FORECAST QUITE AS COOL AS WITH EARLIER FORECASTS. CONVECTION SHOULD FIRE ACROSS CENTRAL GEORGIA MONDAY AFTERNOON AND WITH A PRETTY STRONG VORT LOBE SWINGING AROUND WITH THE SHARP TROUGH ALOFT...EXPECT TO SEE A LITTLE MORE CONVECTIVE DEVELOPMENT THEN. MUCAPES INCREASE TO BETWEEN 800-1500 J/KG ACROSS CENTRAL GEORGIA TOMORROW DEPENDING ON WHICH MODEL ONE USES /NAM IS HIGHER AS USUAL/. STILL HAVE LOW TO MID-RANGE CHANCE POPS AT BEST BUT WILL HAVE TO REEVALUATE THIS OVERNIGHT. DEEP-LAYER CAA BEHIND THE FRONT IS PRETTY IMPRESSIVE ESPECIALLY EARLY TOMORROW ACROSS NORTH GEORGIA...THOUGH THE CAA MODERATES EVER SO SLIGHTLY IN THE AFTERNOON. SHOULD SEE A MARKED DIFFERENCE IN TEMPERATURES BEHIND THE FRONT TOMORROW /5-10 DEGREES COOLER EXCEPT ACROSS SOUTHERN ZONES WHERE THE FRONT WILL NOT HAVE QUITE MADE IT THROUGH YET/ AND ESPECIALLY TOMORROW NIGHT /ANOTHER 5-10 DEGREES COOLER THAN TONIGHT AGAIN EXCEPT FOR SOUTHERN ZONES/. THE DECREASE IN HUMIDITY WILL ALSO BE VERY NOTICEABLE. ENJOY THE BEAUTIFUL FALL WEATHER! TDP LONG TERM /TUESDAY THROUGH SUNDAY/... /ISSUED 317 PM EDT SUN SEP 21 2014/ HIGH PRESSURE AND COOLER TEMPERATURES WILL DOMINATE MUCH OF THE EXTENDED FORECAST PERIOD. HIGH PRESSURE SITUATED ACROSS THE CENTRAL OHIO VALLEY ON TUESDAY WILL SLOWLY SHIFT EASTWARD THROUGH THE WEEK. PROLONGED EASTERLY FLOW OFF OF THE ATLANTIC WILL HELP INCREASE THE CLOUD COVER BY WEDNESDAY. IN ADDITION...THE OLD FRONTAL BOUNDARY ACROSS NORTH-CENTRAL FLORIDA WILL BEGIN TO PUSH NORTHWARD AS A WARM FRONT BY LATE WEDNESDAY INTO EARLY THURSDAY. ISENTROPIC LIFT WILL BEGIN TO INCREASE ACROSS THE SOUTHEAST ZONES BY THE END OF THE WEEK AND SPREAD W THROUGH THE WEEKEND. INSTABILITY LOOKS MINIMAL...BUT AN ISOLD THUNDERSTORM CANNOT BE RULED OUT. NLISTEMAA AVIATION... 00Z UPDATE... /ISSUED 737 PM EDT SUN SEP 21 2014/ MAIN FEATURE TO WATCH TONIGHT WILL BE PRECIPITATION. ALTHOUGH THERE IS A LINE OF STORMS MOVING INTO NW GEORGIA TONIGHT...EXPECT THE COVERAGE TO DIMINISH SOME BEFORE MAKING IT TO THE ATL AREA. SOME SCATTERED SHOWERS STILL POSSIBLE THOUGH AS IT MAKES IT INTO THE ATL AREA. AT THIS POINT...WILL MONITOR AND IF THE LINE HOLDS TOGETHER WILL AMEND FOR SHRA FOR A SHORT PERIOD OF TIME. //ATL CONFIDENCE...00Z UPDATE... MEDIUM CONFIDENCE ON CIGS. HIGH CONFIDENCE ON VSBYS AND WIND. 11 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 64 81 56 79 / 30 20 0 0 ATLANTA 64 80 57 79 / 30 20 0 0 BLAIRSVILLE 56 74 48 76 / 30 5 0 0 CARTERSVILLE 60 78 52 80 / 30 5 0 0 COLUMBUS 68 84 59 83 / 20 20 0 0 GAINESVILLE 63 77 55 77 / 30 5 0 0 MACON 65 85 58 83 / 20 30 0 0 ROME 60 79 50 81 / 30 0 0 0 PEACHTREE CITY 62 80 52 80 / 20 20 0 0 VIDALIA 66 88 64 83 / 5 40 30 10 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...11 LONG TERM....SNELSON AVIATION...11
AREA FORECAST DISCUSSION
NWS JACKSON KY
231 PM EDT SAT SEP 20 2014 .UPDATE... ISSUED AT 231 PM EDT SAT SEP 20 2014 BASED ON SATELLITE TRENDS...IT LOOKS LIKE THE THREAT OF SHOWERS HAS ENDED AS THE BETTER CU FIELD IS WELL OUT TO OUR WEST. THUS...PLAN TO GO DRY FOR THE REMAINDER OF THE DAY. NO OTHER CHANGES MADE AT THIS TIME. UPDATE ISSUED AT 1019 AM EDT SAT SEP 20 2014 BASED ON THE EXPANSION OF THE MID LEVEL AC HAVE OPTED TO GO AHEAD AND EXPAND THE ISOLATED SHOWERS TO MOST OF EASTERN KENTUCKY. THE MID LEVEL AC HAS A FEW VERTICAL TOWERS ALREADY SEEN FROM THE OFFICE. WITH SOME WEAK INSTABILITY COMBINED WITH THE MID LEVEL INSTABILITY...WE SHOULD SEE A FEW SHOWERS POP UP THIS AFTERNOON. EVERYTHING SHOULD REMAIN FAIRLY ISOLATED AND THUNDER DOES NOT LOOK LIKE A THREAT AS INSTABILITY IS NOT STRONG ENOUGH TO SUPPORT IT. OTHERWISE...NO OTHER CHANGES PLANNED AT THIS TIME. UPDATE ISSUED AT 740 AM EDT SAT SEP 20 2014 HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND SATELLITE TRENDS. THIS LED TO SOME MINOR ADJUSTMENTS TO HOURLY TEMPS AND DEWPOINTS TO START THE PERIOD. ANY LINGERING VALLEY FOG SHOULD BE LIFTING AND DISSIPATING SHORTLY...IF IT HAS NOT ALREADY DONE SO. WX GRIDS WERE UPDATED ACCORDINGLY AND AN UPDATED ZFP AND HWO WILL FOLLOW SHORTLY. CONFIDENCE IN THE EVOLUTION AND PLACEMENT OF ANY SHOWERS LATER TODAY REMAINS LOWER THAN AVERAGE. THE NAM HAS BEEN THE MOST INSISTENT ON ISOLATED SHOWER CHANCES FOR TODAY WHILE THE RECENT HRRR RUNS POINT TOWARD THE POTENTIAL FOR A STRAY SHOWER JUST ABOUT ANYWHERE IN THE CWA THIS MORNING INTO THE AFTERNOON...BUT ALSO HAD ACTIVITY EARLIER IN THE MODEL RUN...BETWEEN 8Z AND PRESENT WHICH DID NOT MATERIALIZE. THE CURRENT FORECAST HAS THE SLIGHT CHANCES ACROSS THE WEST OR NORTHWEST IN LINE WITH THE HIGHEST 3Z SREF POPS. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 355 AM EDT SAT SEP 20 2014 EARLY THIS MORNING...AN UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED OVER THE SOUTHERN ROCKIES TO SOUTHERN PLAINS REGION WITH RIDGING EAST INTO THE LOWER OH VALLEY WAS IN PLACE. ACROSS THE SOUTHEASTERN US... A BROAD UPPER LEVEL LOW WAS PRESENT. MEANWHILE A SERIES OF SHORTWAVES WERE IN THE NORTHERN STREAM WITH A WEAK LEAD SHORTWAVE NEAR THE MID MS VALLEY REGION WITH ANOTHER SHORTWAVE NEARING THE NORTHERN GREAT LAKES EXTENDING FROM WESTERN ONTARIO INTO THE UPPER MIDWEST AND DOWN INTO THE CENTRAL PLAINS REGION. FURTHER NORTHWEST ANOTHER SHORTWAVE IS MOVING ACROSS THE CANADIAN PLAINS. THROUGH THE SHORT TERM PERIOD...THE LEAD WEAK SHORTWAVE WILL WORK ACROSS THE AREA THROUGH EARLY TO MID AFTERNOON AS HEIGHTS BEGIN TO FALL IN THE OH VALLEY REGION WHILE THE UPPER LEVEL RIDGE BUILDING NORTH ACROSS THE ROCKIES AND INTO THE INTERIOR NORTHWESTERN US. DOWNSTREAM ACROSS THE GREAT LAKES AND EASTERN US...A TROUGH OF LOW PRESSURE WILL BEGIN TO BE CARVED OUT BY THE TWO MAIN SHORTWAVES AND SOUTHEASTERN CONUS TROUGH BEGINNING TO MERGE INTO IT. THE ASSOCIATED SFC LOW WILL TRACK WELL NORTH OF KY...BUT THE TRAILING COLD FRONT WILL WORK INTO THE LOWER OH VALLEY REGION TONIGHT AND THEN MOVE ACROSS THE COMMONWEALTH THROUGH THE END OF THE PERIOD...WHEN IT SHOULD BE CLOSE TO EXITING INTO VA. SCATTERED TO BROKEN CLOUDS IN THE 4 TO 7KFT RANGE HAVE DEVELOPED OVERNIGHT IN THE WARM SECTOR. OUTSIDE OF THESE CLOUDS VALLEY FOG IS LIKELY STILL PRESENT AND MAY BE DENSE AT LEAST IN SOME SPOTS ALONG THE RIVERS AND LARGER STREAMS AND LAKES. DEWPOINT DEPRESSIONS ARE LARGER NEARER TO THE VA BORDER WHERE A DOWNSLOPE FLOW HAS BEEN PRESENT WITH SPEEDS OF 10 MPH OR MORE ACROSS THE HIGH TERRAIN AND OBSERVATIONS SUPPORT ANY FOG BEING MUCH MORE LOCALIZED THERE. THIS FOG SHOULD GRADUALLY BEGIN TO LIFT THROUGH SUNRISE AND THEN DISSIPATE BY A COUPLE OF HOURS AFTER SUNRISE. IN ADDITION...WHERE CLOUDS FORM THIS FOG WILL TEND TO DISSIPATE AS WELL. THE MODEL GUIDANCE BRINGS THE WEAK MID LEVEL DISTURBANCE TOWARD THE AREA FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY AFTERNOON. THE 0Z NAM AND SOME OF THE NEAR TERM GUIDANCE SUCH AS THE HRRR ALSO DEVELOP SOME CONVECTION THIS MORNING THROUGH EARLY AFTERNOON MAINLY ACROSS THE WESTERN HALF OF THE CWA. MOS GUIDANCE ACROSS THESE LOCATIONS DOES NOT HAVE A SLIGHT CHANCE POPS AND MODEL CONSENSUS BLENDS GENERALLY STAYED BELOW SLIGHT AS WELL. HOWEVER...WE OPTED TO GO WITH SLIGHT CHANCE IN THESE WESTERN LOCATIONS FOR TODAY...WHICH WAS IN BETTER AGREEMENT WITH SURROUNDING WFOS. THE MAIN PRECIPITATION CHANCE DURING THE SHORT TERM PERIOD AND THE ENTIRE FORECAST PERIOD FOR THAT MATTER WILL COME AS THE TROUGH BEGINS TO TAKE SHAPE LATE TONIGHT INTO THE DAY ON SUNDAY AND THE COLD FRONT ENTERS EASTERN KY. THIS COLD FRONT AND THE APPROACHING TROUGH IS EXPECTED TO BRING A BAND OF SCATTERED OR BETTER COVERAGE OF CONVECTION AS IT WILL BE MOVING ACROSS EASTERN KY DURING THE DAYTIME. ISOLATED TO SCATTERED CONVECTION MAY REACH THE NORTHERN PART OF THE CWA TOWARD DAWN...BUT THE BEST CHANCE FOR CONVECTION WILL BE CLOSER TO THE COLD FRONT GENERALLY DURING THE AFTERNOON HOURS. THUNDERSTORMS WILL BE CAPABLE OF BRIEF HEAVY RAIN AND POSSIBLY SOME GUSTY WINDS...PENDING THE DEGREE OF INSTABILITY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 324 AM EDT SAT SEP 20 2014 A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY. MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT DID NOT MENTION FOG AT THIS TIME. AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL PREVAIL DURING THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND. MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 231 PM EDT SAT SEP 20 2014 VFR CONDITIONS WILL CONTINUE OVER THE NEXT 24 TO 36 HOURS. SOME PATCHY VALLEY FOG WILL BE POSSIBLE AGAIN TONIGHT. A COLD FRONT WILL DROP SOUTH INTO THE AREA TOMORROW MORNING WITH CLOUDS AND PRECIPITATION CHANCES ON THE INCREASE. AT THIS TIME...IT APPEARS CIGS SHOULD REMAIN AT OR ABOVE 3500 FEET. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JP LONG TERM...JMW AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1019 AM EDT SAT SEP 20 2014 .UPDATE... ISSUED AT 1019 AM EDT SAT SEP 20 2014 BASED ON THE EXPANSION OF THE MID LEVEL AC HAVE OPTED TO GO AHEAD AND EXPAND THE ISOLATED SHOWERS TO MOST OF EASTERN KENTUCKY. THE MID LEVEL AC HAS A FEW VERTICAL TOWERS ALREADY SEEN FROM THE OFFICE. WITH SOME WEAK INSTABILITY COMBINED WITH THE MID LEVEL INSTABILITY...WE SHOULD SEE A FEW SHOWERS POP UP THIS AFTERNOON. EVERYTHING SHOULD REMAIN FAIRLY ISOLATED AND THUNDER DOES NOT LOOK LIKE A THREAT AS INSTABILITY IS NOT STRONG ENOUGH TO SUPPORT IT. OTHERWISE...NO OTHER CHANGES PLANNED AT THIS TIME. UPDATE ISSUED AT 740 AM EDT SAT SEP 20 2014 HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND SATELLITE TRENDS. THIS LED TO SOME MINOR ADJUSTMENTS TO HOURLY TEMPS AND DEWPOINTS TO START THE PERIOD. ANY LINGERING VALLEY FOG SHOULD BE LIFTING AND DISSIPATING SHORTLY...IF IT HAS NOT ALREADY DONE SO. WX GRIDS WERE UPDATED ACCORDINGLY AND AN UPDATED ZFP AND HWO WILL FOLLOW SHORTLY. CONFIDENCE IN THE EVOLUTION AND PLACEMENT OF ANY SHOWERS LATER TODAY REMAINS LOWER THAN AVERAGE. THE NAM HAS BEEN THE MOST INSISTENT ON ISOLATED SHOWER CHANCES FOR TODAY WHILE THE RECENT HRRR RUNS POINT TOWARD THE POTENTIAL FOR A STRAY SHOWER JUST ABOUT ANYWHERE IN THE CWA THIS MORNING INTO THE AFTERNOON...BUT ALSO HAD ACTIVITY EARLIER IN THE MODEL RUN...BETWEEN 8Z AND PRESENT WHICH DID NOT MATERIALIZE. THE CURRENT FORECAST HAS THE SLIGHT CHANCES ACROSS THE WEST OR NORTHWEST IN LINE WITH THE HIGHEST 3Z SREF POPS. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 355 AM EDT SAT SEP 20 2014 EARLY THIS MORNING...AN UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED OVER THE SOUTHERN ROCKIES TO SOUTHERN PLAINS REGION WITH RIDGING EAST INTO THE LOWER OH VALLEY WAS IN PLACE. ACROSS THE SOUTHEASTERN US... A BROAD UPPER LEVEL LOW WAS PRESENT. MEANWHILE A SERIES OF SHORTWAVES WERE IN THE NORTHERN STREAM WITH A WEAK LEAD SHORTWAVE NEAR THE MID MS VALLEY REGION WITH ANOTHER SHORTWAVE NEARING THE NORTHERN GREAT LAKES EXTENDING FROM WESTERN ONTARIO INTO THE UPPER MIDWEST AND DOWN INTO THE CENTRAL PLAINS REGION. FURTHER NORTHWEST ANOTHER SHORTWAVE IS MOVING ACROSS THE CANADIAN PLAINS. THROUGH THE SHORT TERM PERIOD...THE LEAD WEAK SHORTWAVE WILL WORK ACROSS THE AREA THROUGH EARLY TO MID AFTERNOON AS HEIGHTS BEGIN TO FALL IN THE OH VALLEY REGION WHILE THE UPPER LEVEL RIDGE BUILDING NORTH ACROSS THE ROCKIES AND INTO THE INTERIOR NORTHWESTERN US. DOWNSTREAM ACROSS THE GREAT LAKES AND EASTERN US...A TROUGH OF LOW PRESSURE WILL BEGIN TO BE CARVED OUT BY THE TWO MAIN SHORTWAVES AND SOUTHEASTERN CONUS TROUGH BEGINNING TO MERGE INTO IT. THE ASSOCIATED SFC LOW WILL TRACK WELL NORTH OF KY...BUT THE TRAILING COLD FRONT WILL WORK INTO THE LOWER OH VALLEY REGION TONIGHT AND THEN MOVE ACROSS THE COMMONWEALTH THROUGH THE END OF THE PERIOD...WHEN IT SHOULD BE CLOSE TO EXITING INTO VA. SCATTERED TO BROKEN CLOUDS IN THE 4 TO 7KFT RANGE HAVE DEVELOPED OVERNIGHT IN THE WARM SECTOR. OUTSIDE OF THESE CLOUDS VALLEY FOG IS LIKELY STILL PRESENT AND MAY BE DENSE AT LEAST IN SOME SPOTS ALONG THE RIVERS AND LARGER STREAMS AND LAKES. DEWPOINT DEPRESSIONS ARE LARGER NEARER TO THE VA BORDER WHERE A DOWNSLOPE FLOW HAS BEEN PRESENT WITH SPEEDS OF 10 MPH OR MORE ACROSS THE HIGH TERRAIN AND OBSERVATIONS SUPPORT ANY FOG BEING MUCH MORE LOCALIZED THERE. THIS FOG SHOULD GRADUALLY BEGIN TO LIFT THROUGH SUNRISE AND THEN DISSIPATE BY A COUPLE OF HOURS AFTER SUNRISE. IN ADDITION...WHERE CLOUDS FORM THIS FOG WILL TEND TO DISSIPATE AS WELL. THE MODEL GUIDANCE BRINGS THE WEAK MID LEVEL DISTURBANCE TOWARD THE AREA FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY AFTERNOON. THE 0Z NAM AND SOME OF THE NEAR TERM GUIDANCE SUCH AS THE HRRR ALSO DEVELOP SOME CONVECTION THIS MORNING THROUGH EARLY AFTERNOON MAINLY ACROSS THE WESTERN HALF OF THE CWA. MOS GUIDANCE ACROSS THESE LOCATIONS DOES NOT HAVE A SLIGHT CHANCE POPS AND MODEL CONSENSUS BLENDS GENERALLY STAYED BELOW SLIGHT AS WELL. HOWEVER...WE OPTED TO GO WITH SLIGHT CHANCE IN THESE WESTERN LOCATIONS FOR TODAY...WHICH WAS IN BETTER AGREEMENT WITH SURROUNDING WFOS. THE MAIN PRECIPITATION CHANCE DURING THE SHORT TERM PERIOD AND THE ENTIRE FORECAST PERIOD FOR THAT MATTER WILL COME AS THE TROUGH BEGINS TO TAKE SHAPE LATE TONIGHT INTO THE DAY ON SUNDAY AND THE COLD FRONT ENTERS EASTERN KY. THIS COLD FRONT AND THE APPROACHING TROUGH IS EXPECTED TO BRING A BAND OF SCATTERED OR BETTER COVERAGE OF CONVECTION AS IT WILL BE MOVING ACROSS EASTERN KY DURING THE DAYTIME. ISOLATED TO SCATTERED CONVECTION MAY REACH THE NORTHERN PART OF THE CWA TOWARD DAWN...BUT THE BEST CHANCE FOR CONVECTION WILL BE CLOSER TO THE COLD FRONT GENERALLY DURING THE AFTERNOON HOURS. THUNDERSTORMS WILL BE CAPABLE OF BRIEF HEAVY RAIN AND POSSIBLY SOME GUSTY WINDS...PENDING THE DEGREE OF INSTABILITY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 324 AM EDT SAT SEP 20 2014 A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY. MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT DID NOT MENTION FOG AT THIS TIME. AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL PREVAIL DURING THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND. MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 748 AM EDT SAT SEP 20 2014 ASIDE FROM ANY LINGERING VALLEY FOG LIFTING AND DISSIPATING THROUGH 13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL DURING THE PERIOD. A COLD FRONT AND APPROACHING UPPER LEVEL SYSTEM WILL BRING AN INCREASE IN CLOUDS LATER IN THE PERIOD...AND ISOLATED SHOWERS OR PERHAPS A THUNDERSTORM COULD AFFECT AREAS NORTH OF A SME TO LOZ TO JKL TO SJS LINE VERY LATE IN THE PERIOD. A FEW VALLEY LOCATIONS MAY AGAIN EXPERIENCE FOG BETWEEN 3Z AND 12Z WITH VIS RESTRICTIONS DOWN TO IFR OR MVFR...BUT THIS SHOULD NOT AFFECT THE TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JP LONG TERM...JMW AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
753 AM EDT SAT SEP 20 2014 .UPDATE... ISSUED AT 740 AM EDT SAT SEP 20 2014 HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND SATELLITE TRENDS. THIS LED TO SOME MINOR ADJUSTMENTS TO HOURLY TEMPS AND DEWPOINTS TO START THE PERIOD. ANY LINGERING VALLEY FOG SHOULD BE LIFTING AND DISSIPATING SHORTLY...IF IT HAS NOT ALREADY DONE SO. WX GRIDS WERE UPDATED ACCORDINGLY AND AN UPDATED ZFP AND HWO WILL FOLLOW SHORTLY. CONFIDENCE IN THE EVOLUTION AND PLACEMENT OF ANY SHOWERS LATER TODAY REMAINS LOWER THAN AVERAGE. THE NAM HAS BEEN THE MOST INSISTENT ON ISOLATED SHOWER CHANCES FOR TODAY WHILE THE RECENT HRRR RUNS POINT TOWARD THE POTENTIAL FOR A STRAY SHOWER JUST ABOUT ANYWHERE IN THE CWA THIS MORNING INTO THE AFTERNOON...BUT ALSO HAD ACTIVITY EARLIER IN THE MODEL RUN...BETWEEN 8Z AND PRESENT WHICH DID NOT MATERIALIZE. THE CURRENT FORECAST HAS THE SLIGHT CHANCES ACROSS THE WEST OR NORTHWEST IN LINE WITH THE HIGHEST 3Z SREF POPS. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 355 AM EDT SAT SEP 20 2014 EARLY THIS MORNING...AN UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED OVER THE SOUTHERN ROCKIES TO SOUTHERN PLAINS REGION WITH RIDGING EAST INTO THE LOWER OH VALLEY WAS IN PLACE. ACROSS THE SOUTHEASTERN US... A BROAD UPPER LEVEL LOW WAS PRESENT. MEANWHILE A SERIES OF SHORTWAVES WERE IN THE NORTHERN STREAM WITH A WEAK LEAD SHORTWAVE NEAR THE MID MS VALLEY REGION WITH ANOTHER SHORTWAVE NEARING THE NORTHERN GREAT LAKES EXTENDING FROM WESTERN ONTARIO INTO THE UPPER MIDWEST AND DOWN INTO THE CENTRAL PLAINS REGION. FURTHER NORTHWEST ANOTHER SHORTWAVE IS MOVING ACROSS THE CANADIAN PLAINS. THROUGH THE SHORT TERM PERIOD...THE LEAD WEAK SHORTWAVE WILL WORK ACROSS THE AREA THROUGH EARLY TO MID AFTERNOON AS HEIGHTS BEGIN TO FALL IN THE OH VALLEY REGION WHILE THE UPPER LEVEL RIDGE BUILDING NORTH ACROSS THE ROCKIES AND INTO THE INTERIOR NORTHWESTERN US. DOWNSTREAM ACROSS THE GREAT LAKES AND EASTERN US...A TROUGH OF LOW PRESSURE WILL BEGIN TO BE CARVED OUT BY THE TWO MAIN SHORTWAVES AND SOUTHEASTERN CONUS TROUGH BEGINNING TO MERGE INTO IT. THE ASSOCIATED SFC LOW WILL TRACK WELL NORTH OF KY...BUT THE TRAILING COLD FRONT WILL WORK INTO THE LOWER OH VALLEY REGION TONIGHT AND THEN MOVE ACROSS THE COMMONWEALTH THROUGH THE END OF THE PERIOD...WHEN IT SHOULD BE CLOSE TO EXITING INTO VA. SCATTERED TO BROKEN CLOUDS IN THE 4 TO 7KFT RANGE HAVE DEVELOPED OVERNIGHT IN THE WARM SECTOR. OUTSIDE OF THESE CLOUDS VALLEY FOG IS LIKELY STILL PRESENT AND MAY BE DENSE AT LEAST IN SOME SPOTS ALONG THE RIVERS AND LARGER STREAMS AND LAKES. DEWPOINT DEPRESSIONS ARE LARGER NEARER TO THE VA BORDER WHERE A DOWNSLOPE FLOW HAS BEEN PRESENT WITH SPEEDS OF 10 MPH OR MORE ACROSS THE HIGH TERRAIN AND OBSERVATIONS SUPPORT ANY FOG BEING MUCH MORE LOCALIZED THERE. THIS FOG SHOULD GRADUALLY BEGIN TO LIFT THROUGH SUNRISE AND THEN DISSIPATE BY A COUPLE OF HOURS AFTER SUNRISE. IN ADDITION...WHERE CLOUDS FORM THIS FOG WILL TEND TO DISSIPATE AS WELL. THE MODEL GUIDANCE BRINGS THE WEAK MID LEVEL DISTURBANCE TOWARD THE AREA FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY AFTERNOON. THE 0Z NAM AND SOME OF THE NEAR TERM GUIDANCE SUCH AS THE HRRR ALSO DEVELOP SOME CONVECTION THIS MORNING THROUGH EARLY AFTERNOON MAINLY ACROSS THE WESTERN HALF OF THE CWA. MOS GUIDANCE ACROSS THESE LOCATIONS DOES NOT HAVE A SLIGHT CHANCE POPS AND MODEL CONSENSUS BLENDS GENERALLY STAYED BELOW SLIGHT AS WELL. HOWEVER...WE OPTED TO GO WITH SLIGHT CHANCE IN THESE WESTERN LOCATIONS FOR TODAY...WHICH WAS IN BETTER AGREEMENT WITH SURROUNDING WFOS. THE MAIN PRECIPITATION CHANCE DURING THE SHORT TERM PERIOD AND THE ENTIRE FORECAST PERIOD FOR THAT MATTER WILL COME AS THE TROUGH BEGINS TO TAKE SHAPE LATE TONIGHT INTO THE DAY ON SUNDAY AND THE COLD FRONT ENTERS EASTERN KY. THIS COLD FRONT AND THE APPROACHING TROUGH IS EXPECTED TO BRING A BAND OF SCATTERED OR BETTER COVERAGE OF CONVECTION AS IT WILL BE MOVING ACROSS EASTERN KY DURING THE DAYTIME. ISOLATED TO SCATTERED CONVECTION MAY REACH THE NORTHERN PART OF THE CWA TOWARD DAWN...BUT THE BEST CHANCE FOR CONVECTION WILL BE CLOSER TO THE COLD FRONT GENERALLY DURING THE AFTERNOON HOURS. THUNDERSTORMS WILL BE CAPABLE OF BRIEF HEAVY RAIN AND POSSIBLY SOME GUSTY WINDS...PENDING THE DEGREE OF INSTABILITY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 324 AM EDT SAT SEP 20 2014 A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY. MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT DID NOT MENTION FOG AT THIS TIME. AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL PREVAIL DURING THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND. MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 748 AM EDT SAT SEP 20 2014 ASIDE FROM ANY LINGERING VALLEY FOG LIFTING AND DISSIPATING THROUGH 13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL DURING THE PERIOD. A COLD FRONT AND APPROACHING UPPER LEVEL SYSTEM WILL BRING AN INCREASE IN CLOUDS LATER IN THE PERIOD...AND ISOLATED SHOWERS OR PERHAPS A THUNDERSTORM COULD AFFECT AREAS NORTH OF A SME TO LOZ TO JKL TO SJS LINE VERY LATE IN THE PERIOD. A FEW VALLEY LOCATIONS MAY AGAIN EXPERIENCE FOG BETWEEN 3Z AND 12Z WITH VIS RESTRICTIONS DOWN TO IFR OR MVFR...BUT THIS SHOULD NOT AFFECT THE TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...JP LONG TERM...JMW AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
413 AM EDT SAT SEP 20 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 355 AM EDT SAT SEP 20 2014 EARLY THIS MORNING...AN UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED OVER THE SOUTHERN ROCKIES TO SOUTHERN PLAINS REGION WITH RIDGING EAST INTO THE LOWER OH VALLEY WAS IN PLACE. ACROSS THE SOUTHEASTERN US... A BROAD UPPER LEVEL LOW WAS PRESENT. MEANWHILE A SERIES OF SHORTWAVES WERE IN THE NORTHERN STREAM WITH A WEAK LEAD SHORTWAVE NEAR THE MID MS VALLEY REGION WITH ANOTHER SHORTWAVE NEARING THE NORTHERN GREAT LAKES EXTENDING FROM WESTERN ONTARIO INTO THE UPPER MIDWEST AND DOWN INTO THE CENTRAL PLAINS REGION. FURTHER NORTHWEST ANOTHER SHORTWAVE IS MOVING ACROSS THE CANADIAN PLAINS. THROUGH THE SHORT TERM PERIOD...THE LEAD WEAK SHORTWAVE WILL WORK ACROSS THE AREA THROUGH EARLY TO MID AFTERNOON AS HEIGHTS BEGIN TO FALL IN THE OH VALLEY REGION WHILE THE UPPER LEVEL RIDGE BUILDING NORTH ACROSS THE ROCKIES AND INTO THE INTERIOR NORTHWESTERN US. DOWNSTREAM ACROSS THE GREAT LAKES AND EASTERN US...A TROUGH OF LOW PRESSURE WILL BEGIN TO BE CARVED OUT BY THE TWO MAIN SHORTWAVES AND SOUTHEASTERN CONUS TROUGH BEGINNING TO MERGE INTO IT. THE ASSOCIATED SFC LOW WILL TRACK WELL NORTH OF KY...BUT THE TRAILING COLD FRONT WILL WORK INTO THE LOWER OH VALLEY REGION TONIGHT AND THEN MOVE ACROSS THE COMMONWEALTH THROUGH THE END OF THE PERIOD...WHEN IT SHOULD BE CLOSE TO EXITING INTO VA. SCATTERED TO BROKEN CLOUDS IN THE 4 TO 7KFT RANGE HAVE DEVELOPED OVERNIGHT IN THE WARM SECTOR. OUTSIDE OF THESE CLOUDS VALLEY FOG IS LIKELY STILL PRESENT AND MAY BE DENSE AT LEAST IN SOME SPOTS ALONG THE RIVERS AND LARGER STREAMS AND LAKES. DEWPOINT DEPRESSIONS ARE LARGER NEARER TO THE VA BORDER WHERE A DOWNSLOPE FLOW HAS BEEN PRESENT WITH SPEEDS OF 10 MPH OR MORE ACROSS THE HIGH TERRAIN AND OBSERVATIONS SUPPORT ANY FOG BEING MUCH MORE LOCALIZED THERE. THIS FOG SHOULD GRADUALLY BEGIN TO LIFT THROUGH SUNRISE AND THEN DISSIPATE BY A COUPLE OF HOURS AFTER SUNRISE. IN ADDITION...WHERE CLOUDS FORM THIS FOG WILL TEND TO DISSIPATE AS WELL. THE MODEL GUIDANCE BRINGS THE WEAK MID LEVEL DISTURBANCE TOWARD THE AREA FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY AFTERNOON. THE 0Z NAM AND SOME OF THE NEAR TERM GUIDANCE SUCH AS THE HRRR ALSO DEVELOP SOME CONVECTION THIS MORNING THROUGH EARLY AFTERNOON MAINLY ACROSS THE WESTERN HALF OF THE CWA. MOS GUIDANCE ACROSS THESE LOCATIONS DOES NOT HAVE A SLIGHT CHANCE POPS AND MODEL CONSENSUS BLENDS GENERALLY STAYED BELOW SLIGHT AS WELL. HOWEVER...WE OPTED TO GO WITH SLIGHT CHANCE IN THESE WESTERN LOCATIONS FOR TODAY...WHICH WAS IN BETTER AGREEMENT WITH SURROUNDING WFOS. THE MAIN PRECIPITATION CHANCE DURING THE SHORT TERM PERIOD AND THE ENTIRE FORECAST PERIOD FOR THAT MATTER WILL COME AS THE TROUGH BEGINS TO TAKE SHAPE LATE TONIGHT INTO THE DAY ON SUNDAY AND THE COLD FRONT ENTERS EASTERN KY. THIS COLD FRONT AND THE APPROACHING TROUGH IS EXPECTED TO BRING A BAND OF SCATTERED OR BETTER COVERAGE OF CONVECTION AS IT WILL BE MOVING ACROSS EASTERN KY DURING THE DAYTIME. ISOLATED TO SCATTERED CONVECTION MAY REACH THE NORTHERN PART OF THE CWA TOWARD DAWN...BUT THE BEST CHANCE FOR CONVECTION WILL BE CLOSER TO THE COLD FRONT GENERALLY DURING THE AFTERNOON HOURS. THUNDERSTORMS WILL BE CAPABLE OF BRIEF HEAVY RAIN AND POSSIBLY SOME GUSTY WINDS...PENDING THE DEGREE OF INSTABILITY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 324 AM EDT SAT SEP 20 2014 A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY. MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT DID NOT MENTION FOG AT THIS TIME. AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL PREVAIL DURING THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND. MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 150 AM EDT SAT SEP 20 2014 ASIDE FROM VALLEY FOG DEVELOPING...AND THEN LIFTING AND DISSIPATING THROUGH 13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL DURING THE PERIOD. A COLD FRONT AND ASSOCIATED INCREASE IN CLOUDS IS EXPECTED LATE IN THE PERIOD. THE FOG IS AGAIN EXPECTED TO FOLLOW ITS TYPICAL LATE SUMMER/EARLY AUTUMN PATTERN OF DEVELOPING FIRST IN DEEP VALLEYS AND THEN GROWING IN BREADTH AND DEPTH...WITH THE POTENTIAL TO BEGIN TO REACH SOME RIDGES AND OPEN TERRAIN BY DAWN...SUCH AS MVFR AT SJS IF WINDS SLACKEN AND POSSIBLY MVFR AT SME WHERE THE CURRENT DEWPOINT DEPRESSION IS LOW BUT THERE ARE SCT CLOUDS AS WELL. THE LARGER RECENT OBSERVED DEWPOINT DEPRESSION OF 7 AT LOZ POINTS TOWARD ANY FOG THAT DEVELOPS BEING IN THE VFR RANGE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JP LONG TERM...JMW AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
325 AM EDT SAT SEP 20 2014 .UPDATE... ISSUED AT 140 AM EDT SAT SEP 20 2014 HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND TRENDS. THIS LED TO SLIGHTLY COLDER MIN T IN A COUPLE OF SPOTS ACROSS THE NORTH...WITH THE MAIN CHANGE BEING MORE FOG IN THE GRIDS FOR VALLEY LOCATIONS OUTSIDE OF THE HIGHEST TERRAIN WHERE THE PRESSURE GRADIENT WAS WEAKER. WE HAVE RECEIVED A SPOTTER REPORT OF DENSE FOG NEAR THE RED RIVER IN POWELL COUNTY AND 11-3.9 SAT IMAGERY SUPPORTS VALLEY FOG AT PRESENT IN PARTS OF THE LIKING...BIG SANDY...KENTUCKY AND RED RIVER VALLEYS. SOME OF THE FOG SHOULD AGAIN BE DENSE GENERALLY ALONG THE LARGER CREEKS AND STREAMS AND ESPECIALLY RIVERS AND LARGER LAKES. THE PRESSURE GRADIENT IS EXPECTED TO RELAX A BIT OVERNIGHT ACROSS THE SOUTHEAST PART OF THE CWA SO OUTSIDE OF WHERE SOME CLOUDS DEVELOP IN THE WARM SECTOR...VALLEY FOG SHOULD ALSO DEVELOP THERE TOWARD DAWN. SOME OF THE GUIDANCE INDICATES THE POTENTIAL FOR A FEW STRAY SHOWERS AS A WEAK DISTURBANCE APPROACHES...MAINLY ACROSS THE WESTERN AND NORTHWESTERN PARTS OF THE CWA LATER TONIGHT INTO EARLY ON SATURDAY. CONFIDENCE IN THIS IS NOT ALL THAT HIGH...BUT IT DOES HAVE SUPPORT FROM THE NAM...SOME OF THE RECENT HRRR RUNS AND SOME PRIOR BUT NOT THE MOST RECENT RAP RUN. WE WILL CONTINUE TO EVALUATE THIS POTENTIAL FOR THE SCHEDULED MORNING FORECAST RELEASE. UPDATE ISSUED AT 1027 PM EDT FRI SEP 19 2014 USED OBSERVED TEMPERATURES AND DEW POINTS TO ADJUST HOURLY GRIDS FOR TONIGHT...BLENDING TOWARD THE PREEXISTING FORECAST BY MORNING. NO SUBSTANTIVE CHANGES TO THE OVERALL FORECAST WERE MADE. UPDATE ISSUED AT 729 PM EDT FRI SEP 19 2014 HAVE UPDATED TO ALLOW FOR A FASTER DROP IN VALLEY TEMPS THIS EVENING. ALSO...REDUCED SKY COVER FOR MOST AREAS THIS EVENING. MESOSCALE MODELS ARE PERSISTENT IN SHOWING CLOUDS DEVELOPING NEAR OUR WESTERN BORDER LATE TONIGHT INTO SATURDAY MORNING...A WELL AS SOME SHOWERS. HAVE ACCOUNTED FOR A FEW CLOUDS...BUT KEPT THE FORECAST IN THE JKL FORECAST AREA DRY AT THIS POINT. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 307 PM EDT FRI SEP 19 2014 A LARGE DOME OF HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EAST COAST INTO THE WEEKEND...PROVIDING A DRY START TO THE WEEKEND. STILL A REMOTE CHANCE OF AN ISOLATED SHOWER ACROSS PIKE COUNTY LATER THIS EVENING...BUT CHANCES SEEM TO BE DIMINISHING WITH EVERY HOUR THAT PASSES. THE CU JUST DOES NOT LOOK ALL THAT IMPRESSIVE. REGARDLESS...UNTIL INSTABILITY WANES THIS EVENING CANNOT RULE OUT A BRIEF POP UP SHOWER. SKIES WILL CLEAR OUT AGAIN TONIGHT. WITH DEW POINTS CLIMBING HIGHER TODAY...AND CLEARING SKIES...ANOTHER NIGHT OF FOG CAN BE EXPECTED ACROSS THE AREA. SHOULD BE A FAIRLY TYPICAL FOG FOR THIS TIME OF YEAR. HIGHS WILL CLIMB TO THE HIGHEST READINGS OF THE WEEK ON SATURDAY AS TEMPERATURES CLIMB INTO THE LOW 80S DURING THE AFTERNOON. CLOUDS WILL BE ON THE INCREASE SATURDAY NIGHT AS A COLD FRONT PUSHES SOUTH INTO THE OHIO RIVER VALLEY. PRECIPITATION ASSOCIATED WITH THIS BOUNDARY COULD MAKE IT INTO AREAS NORTH OF 1-64 PRIOR TO 12Z SUNDAY...BUT IT APPEARS THE MAIN PRECIPITATION WITH THE FRONT SHOULD COME COME LATER ON SUNDAY. WITH CLOUDS AND SURFACE MOISTURE INCREASING SATURDAY NIGHT...A MILDER NIGHT IS ON TAP WITH LOWS ONLY INTO THE 60S. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 324 AM EDT SAT SEP 20 2014 A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY. MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT DID NOT MENTION FOG AT THIS TIME. AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL PREVAIL DURING THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND. MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 150 AM EDT SAT SEP 20 2014 ASIDE FROM VALLEY FOG DEVELOPING...AND THEN LIFTING AND DISSIPATING THROUGH 13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL DURING THE PERIOD. A COLD FRONT AND ASSOCIATED INCREASE IN CLOUDS IS EXPECTED LATE IN THE PERIOD. THE FOG IS AGAIN EXPECTED TO FOLLOW ITS TYPICAL LATE SUMMER/EARLY AUTUMN PATTERN OF DEVELOPING FIRST IN DEEP VALLEYS AND THEN GROWING IN BREADTH AND DEPTH...WITH THE POTENTIAL TO BEGIN TO REACH SOME RIDGES AND OPEN TERRAIN BY DAWN...SUCH AS MVFR AT SJS IF WINDS SLACKEN AND POSSIBLY MVFR AT SME WHERE THE CURRENT DEWPOINT DEPRESSION IS LOW BUT THERE ARE SCT CLOUDS AS WELL. THE LARGER RECENT OBSERVED DEWPOINT DEPRESSION OF 7 AT LOZ POINTS TOWARD ANY FOG THAT DEVELOPS BEING IN THE VFR RANGE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...KAS LONG TERM...JMW AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
155 AM EDT SAT SEP 20 2014 .UPDATE... ISSUED AT 140 AM EDT SAT SEP 20 2014 HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND TRENDS. THIS LED TO SLIGHTLY COLDER MIN T IN A COUPLE OF SPOTS ACROSS THE NORTH...WITH THE MAIN CHANGE BEING MORE FOG IN THE GRIDS FOR VALLEY LOCATIONS OUTSIDE OF THE HIGHEST TERRAIN WHERE THE PRESSURE GRADIENT WAS WEAKER. WE HAVE RECEIVED A SPOTTER REPORT OF DENSE FOG NEAR THE RED RIVER IN POWELL COUNTY AND 11-3.9 SAT IMAGERY SUPPORTS VALLEY FOG AT PRESENT IN PARTS OF THE LIKING...BIG SANDY...KENTUCKY AND RED RIVER VALLEYS. SOME OF THE FOG SHOULD AGAIN BE DENSE GENERALLY ALONG THE LARGER CREEKS AND STREAMS AND ESPECIALLY RIVERS AND LARGER LAKES. THE PRESSURE GRADIENT IS EXPECTED TO RELAX A BIT OVERNIGHT ACROSS THE SOUTHEAST PART OF THE CWA SO OUTSIDE OF WHERE SOME CLOUDS DEVELOP IN THE WARM SECTOR...VALLEY FOG SHOULD ALSO DEVELOP THERE TOWARD DAWN. SOME OF THE GUIDANCE INDICATES THE POTENTIAL FOR A FEW STRAY SHOWERS AS A WEAK DISTURBANCE APPROACHES...MAINLY ACROSS THE WESTERN AND NORTHWESTERN PARTS OF THE CWA LATER TONIGHT INTO EARLY ON SATURDAY. CONFIDENCE IN THIS IS NOT ALL THAT HIGH...BUT IT DOES HAVE SUPPORT FROM THE NAM...SOME OF THE RECENT HRRR RUNS AND SOME PRIOR BUT NOT THE MOST RECENT RAP RUN. WE WILL CONTINUE TO EVALUATE THIS POTENTIAL FOR THE SCHEDULED MORNING FORECAST RELEASE. UPDATE ISSUED AT 1027 PM EDT FRI SEP 19 2014 USED OBSERVED TEMPERATURES AND DEW POINTS TO ADJUST HOURLY GRIDS FOR TONIGHT...BLENDING TOWARD THE PREEXISTING FORECAST BY MORNING. NO SUBSTANTIVE CHANGES TO THE OVERALL FORECAST WERE MADE. UPDATE ISSUED AT 729 PM EDT FRI SEP 19 2014 HAVE UPDATED TO ALLOW FOR A FASTER DROP IN VALLEY TEMPS THIS EVENING. ALSO...REDUCED SKY COVER FOR MOST AREAS THIS EVENING. MESOSCALE MODELS ARE PERSISTENT IN SHOWING CLOUDS DEVELOPING NEAR OUR WESTERN BORDER LATE TONIGHT INTO SATURDAY MORNING...A WELL AS SOME SHOWERS. HAVE ACCOUNTED FOR A FEW CLOUDS...BUT KEPT THE FORECAST IN THE JKL FORECAST AREA DRY AT THIS POINT. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 307 PM EDT FRI SEP 19 2014 A LARGE DOME OF HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EAST COAST INTO THE WEEKEND...PROVIDING A DRY START TO THE WEEKEND. STILL A REMOTE CHANCE OF AN ISOLATED SHOWER ACROSS PIKE COUNTY LATER THIS EVENING...BUT CHANCES SEEM TO BE DIMINISHING WITH EVERY HOUR THAT PASSES. THE CU JUST DOES NOT LOOK ALL THAT IMPRESSIVE. REGARDLESS...UNTIL INSTABILITY WANES THIS EVENING CANNOT RULE OUT A BRIEF POP UP SHOWER. SKIES WILL CLEAR OUT AGAIN TONIGHT. WITH DEW POINTS CLIMBING HIGHER TODAY...AND CLEARING SKIES...ANOTHER NIGHT OF FOG CAN BE EXPECTED ACROSS THE AREA. SHOULD BE A FAIRLY TYPICAL FOG FOR THIS TIME OF YEAR. HIGHS WILL CLIMB TO THE HIGHEST READINGS OF THE WEEK ON SATURDAY AS TEMPERATURES CLIMB INTO THE LOW 80S DURING THE AFTERNOON. CLOUDS WILL BE ON THE INCREASE SATURDAY NIGHT AS A COLD FRONT PUSHES SOUTH INTO THE OHIO RIVER VALLEY. PRECIPITATION ASSOCIATED WITH THIS BOUNDARY COULD MAKE IT INTO AREAS NORTH OF 1-64 PRIOR TO 12Z SUNDAY...BUT IT APPEARS THE MAIN PRECIPITATION WITH THE FRONT SHOULD COME COME LATER ON SUNDAY. WITH CLOUDS AND SURFACE MOISTURE INCREASING SATURDAY NIGHT...A MILDER NIGHT IS ON TAP WITH LOWS ONLY INTO THE 60S. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 322 PM EDT FRI SEP 19 2014 ALL OF THE WEATHER IS AT THE FRONT END OF THIS FORECAST PERIOD AS A COLD FRONT IS SET TO SWEEP QUICKLY ACROSS THE AREA ON SUNDAY. MOISTURE RETURN IN ADVANCE OF THE FRONT IS NOT GREAT WITH PWATS ONLY CREEPING UP TO ABOUT 1.5 INCHES IN A THIN RIBBON. COUPLED WITH ONLY WEAK INSTABILITY...ANTICIPATE A NARROW BAND OF SHOWERS AND A FEW THUNDERSTORMS TO ACCOMPANY THE FRONT DURING THE DAY ON SUNDAY. THE BULK OF THIS ACTIVITY SHOULD BE TO OUR SOUTHEAST BY SUNDAY EVENING. FOLLOWING THIS FRONTAL PASSAGE...A LARGE DOME OF HIGH PRESSURE WILL SLIDE ACROSS THE OHIO VALLEY. COUPLED WITH A BUILDING RIDGE ALOFT... THIS SHOULD RESULT IN A PROLONGED PERIOD OF DRY WEATHER WITH PLEASANT TEMPERATURES NEXT WEEK. THERE IS ONE POSSIBLE FLY IN THE OINTMENT THOUGH AS FORECAST MODELS HINT THAT A WEAK UPPER LOW MAY GET TRAPPED TO THE SOUTH OF THE UPPER RIDGE. ALL SIGNS CURRENTLY ARE THAT ANY ASSOCIATED MOISTURE WITH THIS LOW WOULD STAY TO OUR SOUTH AND EAST SO WILL NOT GIVE THIS ANY PLAY IN OUR LOCAL FORECAST AT THIS TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 150 AM EDT SAT SEP 20 2014 ASIDE FROM VALLEY FOG DEVELOPING...AND THEN LIFTING AND DISSIPATING THROUGH 13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL DURING THE PERIOD. A COLD FRONT AND ASSOCIATED INCREASE IN CLOUDS IS EXPECTED LATE IN THE PERIOD. THE FOG IS AGAIN EXPECTED TO FOLLOW ITS TYPICAL LATE SUMMER/EARLY AUTUMN PATTERN OF DEVELOPING FIRST IN DEEP VALLEYS AND THEN GROWING IN BREADTH AND DEPTH...WITH THE POTENTIAL TO BEGIN TO REACH SOME RIDGES AND OPEN TERRAIN BY DAWN...SUCH AS MVFR AT SJS IF WINDS SLACKEN AND POSSIBLY MVFR AT SME WHERE THE CURRENT DEWPOINT DEPRESSION IS LOW BUT THERE ARE SCT CLOUDS AS WELL. THE LARGER RECENT OBSERVED DEWPOINT DEPRESSION OF 7 AT LOZ POINTS TOWARD ANY FOG THAT DEVELOPS BEING IN THE VFR RANGE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...KAS LONG TERM...ABE AVIATION...JP
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
314 PM EDT SAT SEP 20 2014 .SHORT TERM...THIS AFTERNOON AND TONIGHT SEVERAL OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION WELL TO THE WEST ARE TRACKING ACROSS LOWER MICHIGAN. HOWEVER...18Z DTX SOUNDING SHOWS A RATHER ROBUST CAP IN THE 875-850MB AREA...WHICH WILL LIKELY TAKE QUITE SOME TIME TO TOTALLY ERODE. MODELS...INCLUDING PRIMARY AND PARALLEL HRRR RUNS TODAY...SUGGEST CONVECTION WILL EVENTUALLY FILL IN ALONG BOTH OUTFLOW BOUNDARY SINKING SOUTH/SOUTHEAST THROUGH THE CWA AND ALSO ALONG VORTICITY SPOKE FURTHER WEST ASSOCIATED WITH LEFTOVER WEAK MCV. GIVEN CAPPING...AND THE LACK OF SIGNIFICANT INSTABILITY...EXPECT THIS ACTIVITY TO REMAIN RATHER DISORGANIZED AND SUB-SEVERE FOR THE MOST PART. WILL STILL WATCH FOR THE POTENTIAL OF A FEW SEVERE STORMS AS WIND FIELDS ARE DECENT...INCREASING FROM 25-30 KNOTS H85-H7 TO 50 KNOTS AT H5. WITH ADDITIONAL HEATING...TEMPERATURES AROUND 80F DETROIT SOUTH...OVER THE SOUTHERN CWA AND A LACK OF NOTABLE DEEP LOW LEVEL MOISTURE...INVERTED-V SOUNDINGS MAY ASSIST IN GUST POTENTIAL GIVEN THE ABOVE ATMOSPHERIC WIND SPEEDS. THIS INITIAL PUSH OF FORCING...AND WHATEVER CONVECTION COMES OF IT...WILL SHIFT EAST/SOUTHEAST OF THE AREA LATE THIS AFTERNOON/EARLY THIS EVENING. HOWEVER...HIGHER THETA-E AIR WILL CONTINUE TO SHIFT OVER THE CWA...PARTICULARLY M 59 SOUTH...WITHIN SOUTHWEST FLOW IN ADVANCE OF MAIN SHORTWAVE TROUGH AXIS. SO...ADDITIONAL SCATTERED SHOWERS/EMBEDDED STORMS WILL BUILD THROUGH AREA INTO THIS EVENING. ONCE THIS ACTIVITY EBBS LATE THIS EVENING...EXPECT RENEWED SHOWER AND STORM DEVELOPMENT LATE TONIGHT AS MAIN UPPER LEVEL SHORTWAVE DIGS FROM THE UPPER MISSISSIPPI VALLEY INTO THE CENTRAL GREAT LAKES. WITH MILD...SOUTHWEST FLOW PERSISTING THROUGH THE NIGHT...MINIMUM TEMPERATURES WILL BE RATHER MILD...HOLDING IN THE 60S IN MOST LOCATIONS...ESPECIALLY AS FURTHER CLOUDS/PRECIPITATION PROVIDE ADDITIONAL INSOLATION AND MINIMIZE RADIATIONAL COOLING FURTHER. && .LONG TERM... LATEST WATER VAPOR IMAGERY SHOWS A STRONG BUT PROGRESSIVE UPPER LEVEL SYSTEM/CIRCULATION OVER SOUTHERN MANITOBA...WITH A STRONGER EMBEDDED UPPER WAVE AT THE BASE OF THE TROUGH OVER NORTH DAKOTA. IT IS THIS UPPER WAVE/COLD POOL (-18 TO -19 C) WHICH WILL ARRIVE OVER SOUTHERN LOWER MICHIGAN SUNDAY MORNING. WITH SOME LEFTOVER LOW LEVEL MOISTURE AND MORE THAN ADEQUATE MID LEVEL LAPSE RATE (6.5+ C/KM FROM 700-500 MB)...ADDITIONAL SHOWERS AND EMBEDDED THUNDERSTORMS APPEAR LIKELY DURING SUNDAY. A SECONDARY UPPER WAVE/COLD POOL WILL FOLLOW ON THE BACKSIDE THROUGH THE WESTERN GREAT LAKES AND INTO THE OHIO VALLEY. DEEP NORTHERLY FLOW IN THIS SYSTEMS WAKE OVER THE CENTRAL GREAT LAKES WILL ALLOW FOR SOLID COLD ADVECTION TO TAKE PLACE...AS 850 MB TEMPS LOWER INTO THE LOW SINGLE NUMBERS...WITH SLIGHTLY NEGATIVE VALUES OVER LAKE HURON...PER 12Z EURO/NAM. AS SUCH...FULLY ONBOARD WITH THE 12Z NAM 925 MB RH/LOW CLOUDS AS NORTHERLY FLOW COMES OFF THE RELATIVELY WARM WATERS OF LAKE HURON SUNDAY NIGHT. HAVE SUBSEQUENTLY RAMPED UP THE CLOUDS MONDAY MORNING...WHICH WILL LIKELY TAKE MUCH OF THE DAY TO MIX OUT/ERODE...HOLDING MAXES CLOSE TO 60 DEGREES. FAVORABLE RADIATING CONDITIONS MONDAY NIGHT EXPECTED TO ALLOW MINS TO FALL INTO THE 40S. STUBBORN HIGH PRESSURE AND RELENTLESS LOW RH VALUES THROUGH THE COLUMN WILL REMAIN IN PLACE FOR THE ENTIRE EXTENDED PERIOD. FLOW WILL CONTINUE TO BE WEAK UNDER AN OMEGA BLOCKING HIGH. TEMPERATURES WILL TREND SLIGHTLY ABOVE NORMAL WITH NO THREAT OF PRECIPITATION. && .MARINE... WARMER AIRMASS AHEAD OF COLD FRONT...COUPLED WITH THE WEAKENING PRESSURE GRADIENT AS THE FRONT APPROACHES IS TRANSLATING TO WIND SPEEDS BELOW 25 KNOTS...AND WILL DROP THE SMALL CRAFT ADVISORIES. HOWEVER...SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP...AND THUNDERSTORMS WILL BE STRONG TO POSSIBLY SEVERE INTO TONIGHT. A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO ADDITIONAL SHOWERS TOMORROW AND POSSIBLE THUNDERSTORMS. BRISK NORTHERLY WINDS OF 20 TO 25 KNOTS WILL FOLLOW THIS FRONT...ALLOWING LARGE WAVE TO BUILD OVER SOUTHERN LAKE HURON SUNDAY NIGHT INTO MONDAY...WITH SMALL CRAFT ADVISORIES LIKELY NEED DURING THAT TIME FRAME. HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS DURING THE MIDDLE OF NEXT WEEK. && .AVIATION...ISSUED 1251 PM EDT SAT SEP 20 2014 //DISCUSSION... FORCING ALONG LEAD OUTFLOW BOUNDARY/WEAK MCV CENTER SHOULD BRING SCT CONVECTION TO LOWER MICHIGAN BY 17Z-19Z...WELL AHEAD OF THE SYNOPTIC TROUGH AXIS WEST OVER WISCONSIN. THIS ACTIVITY WILL ORGANIZE TO SOME DEGREE AS IT MOVES INTO TERMINALS...BUT GIVEN THE EARLIER ARRIVAL OF ACTIVITY...INSTABILITY WILL REMAIN LIMITED AS SURFACE DEW POINTS STRUGGLE TOWARDS 60F IN ADVANCE OF THIS INITIAL ACTIVITY. AFTER THIS PUSH OF SHRAS/EMBEDDED THUNDER...HIGHER THETA-E AIR WILL CONTINUE TO FUNNEL INTO AREA IN ADVANCE OF MAIN TROUGH...LEADING TO A CONTINUATION OF RATHER DISORGANIZED CONVECTION INTO THE EVENING GENERALLY SOUTH OF M 59. RENEWED ACTIVITY CAN THEN BE EXPECTED BY LATE TONIGHT/SUNDAY MORNING AS MAIN UPPER SHORTWAVE DIGS INTO THE AREA...DURING WHICH TIME CIGS WILL CONSISTENTLY DROP TO MVFR OR PERHAPS IFR AT TIMES. //DTW THRESHOLD THREATS... * LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW BEYOND 22Z THIS AFTERNOON. * LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET AFTER 22Z...WITH PROGRESSIVELY HIGHER CONFIDENCE FROM TONIGHT INTO SUNDAY MORNING. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...DG LONG TERM....SF/MM MARINE.......SF AVIATION.....DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DULUTH MN
612 PM CDT SUN SEP 21 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 301 PM CDT SUN SEP 21 2014 MOST OF THE CLOUDS HAVE DISSIPATED ACROSS THE CWA THIS AFTERNOON...WITH A RIBBON OF THICKER CLOUDS REMAINING JUST WEST OF THE NORTHLAND. THE RAP HAS BEEN CONSISTENT ON BRINGING SOME OF THESE CLOUDS BACK INTO OUR WESTERN/NORTHERN ZONES TONIGHT. THERE IS SOME EASTWARD MOVEMENT TOWARD KOOCHICHING COUNTY OVER THE LAST SEVERAL SATELLITE IMAGES. WE HAVE DO BRING AN INCREASE IN CLOUDS OVER PARTS OF THE WEST/NORTH TONIGHT. HIGH PRESSURE WILL KEEP THE CWA DRY THROUGH MONDAY WITH MORE SUN EXPECTED. LOWS TONIGHT WILL DROP INTO THE UPPER THIRTIES TO LOWER FORTIES. WE WENT ON THE LOW END OF GUIDANCE AND EVEN DROPPED TEMPS A BIT MORE OVER PARTS OF OUR FAR NORTHEAST ZONES AND FROM KHYR TO KPBH. LATER SHIFTS WILL HAVE TO MONITOR TEMPS CLOSELY AS IF THEY DROP A BIT MORE THAN EXPECTED...SOME PATCHY FROST IS POSSIBLE. FOG WILL ALSO BE POSSIBLE TONIGHT. HIGHS MONDAY WILL BE SEVERAL DEGREES ABOVE NORMAL...AND RANGE FORM THE MID SIXTIES TO AROUND SEVENTY. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 301 PM CDT SUN SEP 21 2014 DRY CONDITIONS EXPECTED EARLY IN THE WEEK WITH AN UPPER LEVEL RIDGE BUILDING EWD ACROSS THE UPPER MIDWEST/WRN GREAT LAKES AREA. AT THE SFC A 1025MB HIGH WILL TRANSLATE EWD THROUGH THE SRN GREAT LAKES. A SLY FLOW WILL DEVELOP BEHIND THE DEPARTING HIGH AND AHEAD OF THE NEXT INCOMING AREA OF LOW PRESSURE. THIS NEXT SYSTEM WILL TRACK FROM THE ROCKIES THROUGH THE CENTRAL PLAINS DURING THE DAY TUESDAY. THE MAIN FORCING WILL REMAIN ALOFT ASSOCIATED WITH THE UPPER LOW...WHICH WILL RUN INTO A BLOCKING HIGH TO THE EAST AND LIFT TO THE NE THROUGH NRN MN AND WRN LAKE SUPERIOR LATE TUE NIGHT AND THROUGH THE DAY WED. RAIN SHOWERS WILL ACCOMPANY THIS SYSTEM...AND REMAIN CONFINED TO AREAS NORTH OF MN HIGHWAY 210 AND EWD ALONG THE SOUTH SHORE IN NW WI. RAINFALL AMTS ARE EXPECTED TO BE LIGHT. A BROAD HIGH AMPLITUDE RE-ENFORCING UPPER LEVEL RIDGE IS EXPECTED TO BUILD THROUGH THE CENTRAL U.S. ON THURSDAY...AND INTO THE GREAT LAKES BY FRIDAY. THIS HIGH PRESSURE WILL KEEP CONDITIONS DRY AND WARM THROUGH FRIDAY AND INTO THE WEEKEND. TEMPERATURES THROUGH THE WEEK WILL REMAIN RELATIVELY WARM WITH HIGHS IN THE UPPER 60S AND 70S...AND OVERNIGHT LOWS IN THE 50S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 612 PM CDT SUN SEP 21 2014 BATCH OF CLOUDS MAKING ITS MOVE OVER THE TERMINALS AT THE OUTSET OF THE FORECAST. VFR CIGS ARE EXPECTED. STILL ANTICIPATING SOME BR FORMATION AND KEPT TIMING AND VSBYS FROM PREVIOUS FORECAST. SOME CU STILL FORECAST AFTER 13Z. && .PRELIMINARY POINT TEMPS/POPS... DLH 44 69 48 70 / 0 0 0 0 INL 42 71 45 74 / 0 0 0 0 BRD 44 70 47 72 / 0 0 0 0 HYR 40 67 44 73 / 0 0 0 0 ASX 44 67 47 72 / 0 0 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...MELDE LONG TERM...BJT AVIATION...GSF
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1215 PM MDT SAT SEP 20 2014 .UPDATE... QUICK UPDATE TO RAISE MAX TEMPS FOR THIS AFTERNOON IN THE NORTHEAST. && .AVIATION... 18Z TAF CYCLE STILL SOME IFR CIGS PERSISTING ROUGHLY SE OF A LINE FROM KSRR TO KTCC. KROW WILL BE IMPACTED THE MOST...THOUGH SHOULD SEE IT WAFFLE BTW SCT AND BKN OVER THE NEXT FEW HOURS. EASTERLY WINDS WILL INCREASE AS THE AFTN PROGRESSES...ESPECIALLY BELOW GAPS AT KABQ AND KSAF. MAY NEED TO ISSUE AN AWW LATER FOR KABQ FOR WIND GUSTS GREATER THAN 35KT. OTHERWISE...SOME SPOTTY SHRA AND TSRA ACROSS THE NORTH AND WEST THIS AFTN/EVE. CONFIDENCE IS ONLY HIGH ENOUGH TO INCLUDE A VC MENTION AT THIS TIME AT KFMN...KGUP AND KSAF. SHOULD SEE ANOTHER ROUND OF LIFR/IFR CIGS AND PERHAPS VSBYS AFT 06Z TONIGHT ALONG AND EAST OF THE CENTRAL MT CHAIN. MAY ALSO SEE A FEW SHOWERS DEVELOP AROUND KROW NEAR SUNRISE SUNDAY. 34 && .PREV DISCUSSION...348 AM MDT SAT SEP 20 2014... .SYNOPSIS... VERY MOIST AIR MASS TO REMAIN IN PLACE ACROSS SOUTHEAST NEW MEXICO WHERE SHOWERS AND A FEW THUNDERSTORMS ARE MOST FAVORED. DEEPER MOISTURE WILL EXPAND WESTWARD LATE TODAY AND TONIGHT...WITH SHOWER AND THUNDERSTORM ACTIVITY EXPECTED TO INCREASE AGAIN FOR PARTS OF THE EASTERN PLAINS. AN OVERALL UPTICK IN SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED FOR SUNDAY AND SUNDAY EVENING AS A DISTURBANCE ALOFT PASSES JUST NORTH OF THE STATE AND HELPS TO DRAW MOISTURE FARTHER NORTH AND WEST. DRIER AIR WILL THEN SPREAD EASTWARD INTO NORTHWEST NEW MEXICO MONDAY AND MOST AREAS TUESDAY. MEANWHILE... TEMPERATURES WILL REMAIN GENERALLY ABOVE NORMAL ACROSS THE WEST AND BELOW NORMAL ACROSS THE EAST. BY THE MIDDLE OF NEXT WEEK...A DRYING TREND WILL TAKE A STRONGER HOLD ON THE AREA...AND TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL EXCEPT FOR THE SOUTHEAST PLAINS WHERE COOLER THAN AVERAGE TEMPERATURE WILL LIKELY LINGER. && .DISCUSSION... EXTENSIVE LOW CLOUDS AND AT LEAST PATCHY DENSE FOG EAST OF THE CENTRAL MOUNTAIN CHAIN EARLY THIS MORNING. EXPECT FOG TO DEVELOP/EXPAND AND HAVE GREATEST IMPACT ALONG THE IMMEDIATE EAST SLOPES AND ALONG THE WESTERN FRINGES OF PERSISTENT STRATUS DECK. VERY MOIST AIR MASS REMAINS IN PLACE ACROSS THE SOUTHEAST PLAINS WHERE SURFACE DEW POINT TEMPS SOLIDLY IN THE MID/UPPER 60S. THUS EVEN WEAK UPSLOPE/LOW LEVEL CONVERGENCE IN THIS ENVIRON ENOUGH TO GENERATE ISOLATED ACTIVITY THIS MORNING...AND ALL INDICATIONS POINT TOWARD A GRADUAL STRENGTHENING OF THE E-SE BOUNDARY LAYER WINDS ACROSS THE PLAINS AS THE DAY PROGRESSES AND MORESO INTO THE EVENING HOURS. LATEST 13KM RAPID REFRESH /RAP/ AND HRRR MODEL RUNS CONTINUE TO SUPPORT ISO-SCT COVERAGE FOR THE EC/SE ZONES TODAY. AND GOOD AGREEMENT BETWEEN GFS/NAM SUPPORTING PREVIOUS POP/WX TRENDS INCREASING POP FOR SE 1/4 TONIGHT WITH A PREFERRED AXIS ALONG/WEST OF THE PECOS RIVER VALLEY TO EAST SLOPES OF THE SC MOUNTAINS WHERE UPSLOPE EFFECTS WILL BE MAXIMIZED. OUTSIDE THE SC MTNS AND EC/SE PLAINS...A PREDOMINATELY DRY AND UNSEASONABLY WARM FORECAST TODAY BENEATH GRADUALLY STRENGTHENING HIGH PRESSURE ALOFT THAT SHOULD CENTER NEAR OR JUST NORTH OF THE NM/CO LINE TODAY BEFORE DEFLATING AND SHIFTING EAST AND SOUTH TONIGHT- SUNDAY. THE SLIGHT AMPLIFICATION OF THE RIDGE ALOFT TODAY AND THEN TRENDS INTO SUNDAY DUE TO A CLOSED LOW FORECAST TO MOVE INTO CENTRAL CA LATE TODAY- TONIGHT THEN ACROSS THE GREAT BASIN SUNDAY. THE ONE EXCEPTION TO THE PREDOMINATELY DRY FORECAST TODAY WILL BE CATRON COUNTY/UPPER GILA REGION EXTENDING NORTH TOWARD THE ZUNI MOUNTAINS NEAR THE NM/AZ LINE WHERE MID LEVEL MOISTURE EXPECTED TO ADVECT NORTHWARD IN THE DEVELOPING S-SELY FLOW. AN EXPANSION OF ISOLATED TO SCATTERED POPS EXPECTED AREAWIDE BY SUNDAY...ESPECIALLY THE NORTH AND WEST...AS FORCING FOR LARGE- SCALE LIFT AIDS CONVECTION SUNDAY PM. SURFACE PRESSURE FALLS TO THE WEST OF THE STATE ASSOCIATED WITH THE CA LOW PRESSURE SYSTEM MOST LIKELY RESPONSIBLE FOR THE STRENGTHENING E-SELY BOUNDARY LAYER LATE TODAY AND TONIGHT. THIS WILL BRING HIGHER DEW POINT AIR WESTWARD CONTRIBUTING TO THE OVERALL IMPROVING SHRA/TSRA CHANCES. STORM MOTIONS WILL BE FAIRLY FAST BUT COULD SEE A FEW STRONG CELLS DEVELOP SUNDAY PM NW ZONES. CLOSED LOW TO OPEN UP AND PASS NORTH OF THE STATE MONDAY...WITH PROGRESSIVELY DRIER AIR MASS INTO THE FOUR CORNERS. BEST POPS FROM NE TO SW. TRANSITION TO NWLY FLOW ALOFT ON TUESDAY THAT WOULD FAVOR THE NC/NE AREAS BUT WITH RESIDUAL MOISTURE CANNOT RULE OUT ISOLATED- SCATTERED SHRA/TSRA ACROSS THE EAST AND SOUTH. DEFINITE DRYING TREND NC/NW ZONES. FOR WED AND BEYOND...ANOTHER DEEP TROUGH INDICATED INTO THE WEST COAST LATE NEXT WEEK BUT MUCH UNCERTAINTY ON HOW QUICKLY IT WILL PROGRESS EAST. FARTHER DOWNSTREAM OVER OUR REGION... POSITIVELY TILTED UPPER RIDGE MOST LIKELY TO DOMINATE WITH A DEFORMATION AXIS OF SOME SORTS STRETCHING FROM THE CENTRAL PLAINS STATES INTO FAR EASTERN NM BUT LOW CONFIDENCE. LOW GRADE POP FORECAST IN PLACE FOR NOW WITH TEMPS GENERALLY BELOW NORMAL EAST...AND NEAR TO SLIGHTLY ABOVE WEST. KJ && .FIRE WEATHER... UPPER LOW NEAR THE CENTRAL TO S CALIFORNIA COAST TO BE AN IMPORTANT DRIVER IN LOWERING SFC PRESSURE OVER OR JUST W OF W NM WHICH WILL SHIFT WINDS TO SOMEWHAT OF AN EASTERLY COMPONENT ACROSS MOST OF THE EAST TWO THIRDS OR THREE QUARTERS OF NM BY LATE AM TO EARLY PM TODAY. SOME DRYING THANKS TO A MODERATE MID LEVEL DRY INTRUSION EXPECTED MAINLY ACROSS WESTERN AREAS. THE BEST CHANCE OF WETTING RAIN TO BE FOUND ACROSS THE SE AND ALSO MUCH OF THE HIGHER TERRAIN ELSEWHERE. GAP WIND GUSTS RANGING FROM 30 TO 40 MPH WILL BE EXPECTED ALONG THE RIO GRANDE VALLEY TONIGHT INTO SUN MORNING. RESIDUAL SFC MOISTURE AND MID TO UPPER LVL FLOW SHIFTING FROM E AND NE TODAY TO MORE OF A SE TO S FLOW SUN TO SUN NIGHT PERIOD. THIS SHOULD HELP ENHANCE WETTING RAIN POTENTIAL FOR SUN...FAVORING MOST THE CENTRAL MTN CHAIN AND EAST AS WELL AS AREAS NEAR TO WEST OF THE DIVIDE. AFTN TEMPS SHOULD BE WILL COOL ROUGHLY 5 TO 10 DEGREES MOST SPOTS EXCEPT PERHAPS A BIT LESS SO ACROSS FAR E NM...BUT REMAIN NEAR NORMAL ACROSS ROUGHLY THE NE HALF OF THE STATE. SOME BREEZY LEVEL WIND AREAS EMBEDDED IN THE GENERALLY S TO SE FLOW SUN. VENTILATION RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40 CORRIDOR. MON TO AGAIN SOME WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES IN THE EAST AND TO SOME DEGREE SOUTH...LESS WETTING RAIN POTENTIAL WITH NEAR NORMAL TEMPERATURES TO THE NW. VENTILATION NOT EXPECTED TO CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS GENERALLY ALONG AND NORTH OF I40. A DRYING TREND STILL APPEARS TO BE IN THE CARDS OVER THE AREA STARTING TUE INTO AT LEAST THU...THOUGH A WEAK FRONTAL BOUNDARY IS STILL ANTICIPATED MID WEEK AND FAVOR THE EAST SLOPES OF THE CENTRAL MTNS EASTWARD. VENTILATION IS EXPECTED TO LOWER SOME, THOUGH NOT DRASTICALLY...TUE AND WED. THE NEXT UPPER TROUGH STILL LOOKS TO APPROACH FOR LATE WEEK INTO THE FOLLOWING WEEKEND. SOME FCST MODEL DIFFERENCES REMAIN IN STRENGTH AND TIMING. GFS MODEL STILL LOOKS DEEPER AND SOMEWHAT FASTER WITH THE TROUGH THUS SOME WIND IMPACTS POSSIBLE AHEAD OF IT. THIS SHOULD IMPROVE VENTILATION RATES. ECMWF STILL IS A BIT SLOWER. MODEL DIFFERENCES STILL DRIVING DOWN CONFIDENCE SOME FOR LATE WEEK INTO NEXT WEEK. 43 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1148 AM MDT SAT SEP 20 2014 .AVIATION... 18Z TAF CYCLE STILL SOME IFR CIGS PERSISTING ROUGHLY SE OF A LINE FROM KSRR TO KTCC. KROW WILL BE IMPACTED THE MOST...THOUGH SHOULD SEE IT WAFFLE BTW SCT AND BKN OVER THE NEXT FEW HOURS. EASTERLY WINDS WILL INCREASE AS THE AFTN PROGRESSES...ESPECIALLY BELOW GAPS AT KABQ AND KSAF. MAY NEED TO ISSUE AN AWW LATER FOR KABQ FOR WIND GUSTS GREATER THAN 35KT. OTHERWISE...SOME SPOTTY SHRA AND TSRA ACROSS THE NORTH AND WEST THIS AFTN/EVE. CONFIDENCE IS ONLY HIGH ENOUGH TO INCLUDE A VC MENTION AT THIS TIME AT KFMN...KGUP AND KSAF. SHOULD SEE ANOTHER ROUND OF LIFR/IFR CIGS AND PERHAPS VSBYS AFT 06Z TONIGHT ALONG AND EAST OF THE CENTRAL MT CHAIN. MAY ALSO SEE A FEW SHOWERS DEVELOP AROUND KROW NEAR SUNRISE SUNDAY. 34 && .PREV DISCUSSION...348 AM MDT SAT SEP 20 2014... .SYNOPSIS... VERY MOIST AIR MASS TO REMAIN IN PLACE ACROSS SOUTHEAST NEW MEXICO WHERE SHOWERS AND A FEW THUNDERSTORMS ARE MOST FAVORED. DEEPER MOISTURE WILL EXPAND WESTWARD LATE TODAY AND TONIGHT...WITH SHOWER AND THUNDERSTORM ACTIVITY EXPECTED TO INCREASE AGAIN FOR PARTS OF THE EASTERN PLAINS. AN OVERALL UPTICK IN SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED FOR SUNDAY AND SUNDAY EVENING AS A DISTURBANCE ALOFT PASSES JUST NORTH OF THE STATE AND HELPS TO DRAW MOISTURE FARTHER NORTH AND WEST. DRIER AIR WILL THEN SPREAD EASTWARD INTO NORTHWEST NEW MEXICO MONDAY AND MOST AREAS TUESDAY. MEANWHILE... TEMPERATURES WILL REMAIN GENERALLY ABOVE NORMAL ACROSS THE WEST AND BELOW NORMAL ACROSS THE EAST. BY THE MIDDLE OF NEXT WEEK...A DRYING TREND WILL TAKE A STRONGER HOLD ON THE AREA...AND TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL EXCEPT FOR THE SOUTHEAST PLAINS WHERE COOLER THAN AVERAGE TEMPERATURE WILL LIKELY LINGER. && .DISCUSSION... EXTENSIVE LOW CLOUDS AND AT LEAST PATCHY DENSE FOG EAST OF THE CENTRAL MOUNTAIN CHAIN EARLY THIS MORNING. EXPECT FOG TO DEVELOP/EXPAND AND HAVE GREATEST IMPACT ALONG THE IMMEDIATE EAST SLOPES AND ALONG THE WESTERN FRINGES OF PERSISTENT STRATUS DECK. VERY MOIST AIR MASS REMAINS IN PLACE ACROSS THE SOUTHEAST PLAINS WHERE SURFACE DEW POINT TEMPS SOLIDLY IN THE MID/UPPER 60S. THUS EVEN WEAK UPSLOPE/LOW LEVEL CONVERGENCE IN THIS ENVIRON ENOUGH TO GENERATE ISOLATED ACTIVITY THIS MORNING...AND ALL INDICATIONS POINT TOWARD A GRADUAL STRENGTHENING OF THE E-SE BOUNDARY LAYER WINDS ACROSS THE PLAINS AS THE DAY PROGRESSES AND MORESO INTO THE EVENING HOURS. LATEST 13KM RAPID REFRESH /RAP/ AND HRRR MODEL RUNS CONTINUE TO SUPPORT ISO-SCT COVERAGE FOR THE EC/SE ZONES TODAY. AND GOOD AGREEMENT BETWEEN GFS/NAM SUPPORTING PREVIOUS POP/WX TRENDS INCREASING POP FOR SE 1/4 TONIGHT WITH A PREFERRED AXIS ALONG/WEST OF THE PECOS RIVER VALLEY TO EAST SLOPES OF THE SC MOUNTAINS WHERE UPSLOPE EFFECTS WILL BE MAXIMIZED. OUTSIDE THE SC MTNS AND EC/SE PLAINS...A PREDOMINATELY DRY AND UNSEASONABLY WARM FORECAST TODAY BENEATH GRADUALLY STRENGTHENING HIGH PRESSURE ALOFT THAT SHOULD CENTER NEAR OR JUST NORTH OF THE NM/CO LINE TODAY BEFORE DEFLATING AND SHIFTING EAST AND SOUTH TONIGHT- SUNDAY. THE SLIGHT AMPLIFICATION OF THE RIDGE ALOFT TODAY AND THEN TRENDS INTO SUNDAY DUE TO A CLOSED LOW FORECAST TO MOVE INTO CENTRAL CA LATE TODAY- TONIGHT THEN ACROSS THE GREAT BASIN SUNDAY. THE ONE EXCEPTION TO THE PREDOMINATELY DRY FORECAST TODAY WILL BE CATRON COUNTY/UPPER GILA REGION EXTENDING NORTH TOWARD THE ZUNI MOUNTAINS NEAR THE NM/AZ LINE WHERE MID LEVEL MOISTURE EXPECTED TO ADVECT NORTHWARD IN THE DEVELOPING S-SELY FLOW. AN EXPANSION OF ISOLATED TO SCATTERED POPS EXPECTED AREAWIDE BY SUNDAY...ESPECIALLY THE NORTH AND WEST...AS FORCING FOR LARGE- SCALE LIFT AIDS CONVECTION SUNDAY PM. SURFACE PRESSURE FALLS TO THE WEST OF THE STATE ASSOCIATED WITH THE CA LOW PRESSURE SYSTEM MOST LIKELY RESPONSIBLE FOR THE STRENGTHENING E-SELY BOUNDARY LAYER LATE TODAY AND TONIGHT. THIS WILL BRING HIGHER DEW POINT AIR WESTWARD CONTRIBUTING TO THE OVERALL IMPROVING SHRA/TSRA CHANCES. STORM MOTIONS WILL BE FAIRLY FAST BUT COULD SEE A FEW STRONG CELLS DEVELOP SUNDAY PM NW ZONES. CLOSED LOW TO OPEN UP AND PASS NORTH OF THE STATE MONDAY...WITH PROGRESSIVELY DRIER AIR MASS INTO THE FOUR CORNERS. BEST POPS FROM NE TO SW. TRANSITION TO NWLY FLOW ALOFT ON TUESDAY THAT WOULD FAVOR THE NC/NE AREAS BUT WITH RESIDUAL MOISTURE CANNOT RULE OUT ISOLATED- SCATTERED SHRA/TSRA ACROSS THE EAST AND SOUTH. DEFINITE DRYING TREND NC/NW ZONES. FOR WED AND BEYOND...ANOTHER DEEP TROUGH INDICATED INTO THE WEST COAST LATE NEXT WEEK BUT MUCH UNCERTAINTY ON HOW QUICKLY IT WILL PROGRESS EAST. FARTHER DOWNSTREAM OVER OUR REGION... POSITIVELY TILTED UPPER RIDGE MOST LIKELY TO DOMINATE WITH A DEFORMATION AXIS OF SOME SORTS STRETCHING FROM THE CENTRAL PLAINS STATES INTO FAR EASTERN NM BUT LOW CONFIDENCE. LOW GRADE POP FORECAST IN PLACE FOR NOW WITH TEMPS GENERALLY BELOW NORMAL EAST...AND NEAR TO SLIGHTLY ABOVE WEST. KJ && .FIRE WEATHER... UPPER LOW NEAR THE CENTRAL TO S CALIFORNIA COAST TO BE AN IMPORTANT DRIVER IN LOWERING SFC PRESSURE OVER OR JUST W OF W NM WHICH WILL SHIFT WINDS TO SOMEWHAT OF AN EASTERLY COMPONENT ACROSS MOST OF THE EAST TWO THIRDS OR THREE QUARTERS OF NM BY LATE AM TO EARLY PM TODAY. SOME DRYING THANKS TO A MODERATE MID LEVEL DRY INTRUSION EXPECTED MAINLY ACROSS WESTERN AREAS. THE BEST CHANCE OF WETTING RAIN TO BE FOUND ACROSS THE SE AND ALSO MUCH OF THE HIGHER TERRAIN ELSEWHERE. GAP WIND GUSTS RANGING FROM 30 TO 40 MPH WILL BE EXPECTED ALONG THE RIO GRANDE VALLEY TONIGHT INTO SUN MORNING. RESIDUAL SFC MOISTURE AND MID TO UPPER LVL FLOW SHIFTING FROM E AND NE TODAY TO MORE OF A SE TO S FLOW SUN TO SUN NIGHT PERIOD. THIS SHOULD HELP ENHANCE WETTING RAIN POTENTIAL FOR SUN...FAVORING MOST THE CENTRAL MTN CHAIN AND EAST AS WELL AS AREAS NEAR TO WEST OF THE DIVIDE. AFTN TEMPS SHOULD BE WILL COOL ROUGHLY 5 TO 10 DEGREES MOST SPOTS EXCEPT PERHAPS A BIT LESS SO ACROSS FAR E NM...BUT REMAIN NEAR NORMAL ACROSS ROUGHLY THE NE HALF OF THE STATE. SOME BREEZY LEVEL WIND AREAS EMBEDDED IN THE GENERALLY S TO SE FLOW SUN. VENTILATION RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40 CORRIDOR. MON TO AGAIN SOME WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES IN THE EAST AND TO SOME DEGREE SOUTH...LESS WETTING RAIN POTENTIAL WITH NEAR NORMAL TEMPERATURES TO THE NW. VENTILATION NOT EXPECTED TO CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS GENERALLY ALONG AND NORTH OF I40. A DRYING TREND STILL APPEARS TO BE IN THE CARDS OVER THE AREA STARTING TUE INTO AT LEAST THU...THOUGH A WEAK FRONTAL BOUNDARY IS STILL ANTICIPATED MID WEEK AND FAVOR THE EAST SLOPES OF THE CENTRAL MTNS EASTWARD. VENTILATION IS EXPECTED TO LOWER SOME, THOUGH NOT DRASTICALLY...TUE AND WED. THE NEXT UPPER TROUGH STILL LOOKS TO APPROACH FOR LATE WEEK INTO THE FOLLOWING WEEKEND. SOME FCST MODEL DIFFERENCES REMAIN IN STRENGTH AND TIMING. GFS MODEL STILL LOOKS DEEPER AND SOMEWHAT FASTER WITH THE TROUGH THUS SOME WIND IMPACTS POSSIBLE AHEAD OF IT. THIS SHOULD IMPROVE VENTILATION RATES. ECMWF STILL IS A BIT SLOWER. MODEL DIFFERENCES STILL DRIVING DOWN CONFIDENCE SOME FOR LATE WEEK INTO NEXT WEEK. 43 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
616 AM MDT SAT SEP 20 2014 .AVIATION... 12Z TAF CYCLE WIDESPREAD IFR AND SPOTTY LIFR CIGS AND VSBY ACROSS GOOD PORTION OF SE PLAINS WEST AND THEN NORTH ACROSS THE EAST SLOPES OF CENTRAL MT CHAIN AND IMMEDIATELY ADJACENT HIGHLANDS TO THE EAST TIL AT LEAST 15Z OR 16Z BEFORE SOME RISE OR BREAKS IN CIGS SETS IN. EXPECT MT OBSCURATIONS AS WELL. ELSEWHERE IN EAST NM CIGS ARE A LITTLE LESS WIDESPREAD AND GENERALLY MVFR WITH SOME SPOTTY IFR MIXED IN. THIS ALSO TO IMPROVE MID TO LATE MORN. MOSTLY VFR CONDITIONS TO WEST OF CENTRAL MT CHAIN. NEAR SFC WIND FLOW TO TURN TO MORE OF AN EASTERLY COMPONENT AS THE DAY PROGRESSES TODAY. BELOW CANYONS AND PASSES OF CENTRAL MT CHAIN E TO SE WIND GUSTS WILL DEVELOP BETWEEN 21 AND 00Z. MAINLY FROM NEAR 00Z AND ABOUT 09Z OR A BIT LATER WIND GUSTS TO REACH BETWEEN 28 AND 35 KTS BELOW CANYONS...INCLUDING ABQ AND SAF WITH SUSTAINED SPEEDS BETWEEN 15 AND 26 KT. SOME SPOTTY SHRA/TSRA TO REDEVELOP MAINLY SOUTHERN AND WESTERN AREAS NEAR AND ESPECIALLY AFTER 20Z...FAVORING HIGHER TERRAIN AT FIRST...MORE ISOLATED ACTIVITY ACROSS NORTHERN MTS. SOME ACTIVITY TO CONTINUE OVERNIGHT TONIGHT. ALSO SOME MVFR AND IFR CIGS AGAIN FAIRLY LIKELY LATER TONIGHT ALONG EAST SLOPES CENTRAL MT CHAIN AS WELL AS SE AND PERHAPS E CENTRAL PLAINS. 43 && .PREV DISCUSSION...348 AM MDT SAT SEP 20 2014... .SYNOPSIS... VERY MOIST AIR MASS TO REMAIN IN PLACE ACROSS SOUTHEAST NEW MEXICO WHERE SHOWERS AND A FEW THUNDERSTORMS ARE MOST FAVORED. DEEPER MOISTURE WILL EXPAND WESTWARD LATE TODAY AND TONIGHT...WITH SHOWER AND THUNDERSTORM ACTIVITY EXPECTED TO INCREASE AGAIN FOR PARTS OF THE EASTERN PLAINS. AN OVERALL UPTICK IN SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED FOR SUNDAY AND SUNDAY EVENING AS A DISTURBANCE ALOFT PASSES JUST NORTH OF THE STATE AND HELPS TO DRAW MOISTURE FARTHER NORTH AND WEST. DRIER AIR WILL THEN SPREAD EASTWARD INTO NORTHWEST NEW MEXICO MONDAY AND MOST AREAS TUESDAY. MEANWHILE... TEMPERATURES WILL REMAIN GENERALLY ABOVE NORMAL ACROSS THE WEST AND BELOW NORMAL ACROSS THE EAST. BY THE MIDDLE OF NEXT WEEK...A DRYING TREND WILL TAKE A STRONGER HOLD ON THE AREA...AND TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL EXCEPT FOR THE SOUTHEAST PLAINS WHERE COOLER THAN AVERAGE TEMPERATURE WILL LIKELY LINGER. && .DISCUSSION... EXTENSIVE LOW CLOUDS AND AT LEAST PATCHY DENSE FOG EAST OF THE CENTRAL MOUNTAIN CHAIN EARLY THIS MORNING. EXPECT FOG TO DEVELOP/EXPAND AND HAVE GREATEST IMPACT ALONG THE IMMEDIATE EAST SLOPES AND ALONG THE WESTERN FRINGES OF PERSISTENT STRATUS DECK. VERY MOIST AIR MASS REMAINS IN PLACE ACROSS THE SOUTHEAST PLAINS WHERE SURFACE DEW POINT TEMPS SOLIDLY IN THE MID/UPPER 60S. THUS EVEN WEAK UPSLOPE/LOW LEVEL CONVERGENCE IN THIS ENVIRON ENOUGH TO GENERATE ISOLATED ACTIVITY THIS MORNING...AND ALL INDICATIONS POINT TOWARD A GRADUAL STRENGTHENING OF THE E-SE BOUNDARY LAYER WINDS ACROSS THE PLAINS AS THE DAY PROGRESSES AND MORESO INTO THE EVENING HOURS. LATEST 13KM RAPID REFRESH /RAP/ AND HRRR MODEL RUNS CONTINUE TO SUPPORT ISO-SCT COVERAGE FOR THE EC/SE ZONES TODAY. AND GOOD AGREEMENT BETWEEN GFS/NAM SUPPORTING PREVIOUS POP/WX TRENDS INCREASING POP FOR SE 1/4 TONIGHT WITH A PREFERRED AXIS ALONG/WEST OF THE PECOS RIVER VALLEY TO EAST SLOPES OF THE SC MOUNTAINS WHERE UPSLOPE EFFECTS WILL BE MAXIMIZED. OUTSIDE THE SC MTNS AND EC/SE PLAINS...A PREDOMINATELY DRY AND UNSEASONABLY WARM FORECAST TODAY BENEATH GRADUALLY STRENGTHENING HIGH PRESSURE ALOFT THAT SHOULD CENTER NEAR OR JUST NORTH OF THE NM/CO LINE TODAY BEFORE DEFLATING AND SHIFTING EAST AND SOUTH TONIGHT- SUNDAY. THE SLIGHT AMPLIFICATION OF THE RIDGE ALOFT TODAY AND THEN TRENDS INTO SUNDAY DUE TO A CLOSED LOW FORECAST TO MOVE INTO CENTRAL CA LATE TODAY- TONIGHT THEN ACROSS THE GREAT BASIN SUNDAY. THE ONE EXCEPTION TO THE PREDOMINATELY DRY FORECAST TODAY WILL BE CATRON COUNTY/UPPER GILA REGION EXTENDING NORTH TOWARD THE ZUNI MOUNTAINS NEAR THE NM/AZ LINE WHERE MID LEVEL MOISTURE EXPECTED TO ADVECT NORTHWARD IN THE DEVELOPING S-SELY FLOW. AN EXPANSION OF ISOLATED TO SCATTERED POPS EXPECTED AREAWIDE BY SUNDAY...ESPECIALLY THE NORTH AND WEST...AS FORCING FOR LARGE- SCALE LIFT AIDS CONVECTION SUNDAY PM. SURFACE PRESSURE FALLS TO THE WEST OF THE STATE ASSOCIATED WITH THE CA LOW PRESSURE SYSTEM MOST LIKELY RESPONSIBLE FOR THE STRENGTHENING E-SELY BOUNDARY LAYER LATE TODAY AND TONIGHT. THIS WILL BRING HIGHER DEW POINT AIR WESTWARD CONTRIBUTING TO THE OVERALL IMPROVING SHRA/TSRA CHANCES. STORM MOTIONS WILL BE FAIRLY FAST BUT COULD SEE A FEW STRONG CELLS DEVELOP SUNDAY PM NW ZONES. CLOSED LOW TO OPEN UP AND PASS NORTH OF THE STATE MONDAY...WITH PROGRESSIVELY DRIER AIR MASS INTO THE FOUR CORNERS. BEST POPS FROM NE TO SW. TRANSITION TO NWLY FLOW ALOFT ON TUESDAY THAT WOULD FAVOR THE NC/NE AREAS BUT WITH RESIDUAL MOISTURE CANNOT RULE OUT ISOLATED- SCATTERED SHRA/TSRA ACROSS THE EAST AND SOUTH. DEFINITE DRYING TREND NC/NW ZONES. FOR WED AND BEYOND...ANOTHER DEEP TROUGH INDICATED INTO THE WEST COAST LATE NEXT WEEK BUT MUCH UNCERTAINTY ON HOW QUICKLY IT WILL PROGRESS EAST. FARTHER DOWNSTREAM OVER OUR REGION... POSITIVELY TILTED UPPER RIDGE MOST LIKELY TO DOMINATE WITH A DEFORMATION AXIS OF SOME SORTS STRETCHING FROM THE CENTRAL PLAINS STATES INTO FAR EASTERN NM BUT LOW CONFIDENCE. LOW GRADE POP FORECAST IN PLACE FOR NOW WITH TEMPS GENERALLY BELOW NORMAL EAST...AND NEAR TO SLIGHTLY ABOVE WEST. KJ && .FIRE WEATHER... UPPER LOW NEAR THE CENTRAL TO S CALIFORNIA COAST TO BE AN IMPORTANT DRIVER IN LOWERING SFC PRESSURE OVER OR JUST W OF W NM WHICH WILL SHIFT WINDS TO SOMEWHAT OF AN EASTERLY COMPONENT ACROSS MOST OF THE EAST TWO THIRDS OR THREE QUARTERS OF NM BY LATE AM TO EARLY PM TODAY. SOME DRYING THANKS TO A MODERATE MID LEVEL DRY INTRUSION EXPECTED MAINLY ACROSS WESTERN AREAS. THE BEST CHANCE OF WETTING RAIN TO BE FOUND ACROSS THE SE AND ALSO MUCH OF THE HIGHER TERRAIN ELSEWHERE. GAP WIND GUSTS RANGING FROM 30 TO 40 MPH WILL BE EXPECTED ALONG THE RIO GRANDE VALLEY TONIGHT INTO SUN MORNING. RESIDUAL SFC MOISTURE AND MID TO UPPER LVL FLOW SHIFTING FROM E AND NE TODAY TO MORE OF A SE TO S FLOW SUN TO SUN NIGHT PERIOD. THIS SHOULD HELP ENHANCE WETTING RAIN POTENTIAL FOR SUN...FAVORING MOST THE CENTRAL MTN CHAIN AND EAST AS WELL AS AREAS NEAR TO WEST OF THE DIVIDE. AFTN TEMPS SHOULD BE WILL COOL ROUGHLY 5 TO 10 DEGREES MOST SPOTS EXCEPT PERHAPS A BIT LESS SO ACROSS FAR E NM...BUT REMAIN NEAR NORMAL ACROSS ROUGHLY THE NE HALF OF THE STATE. SOME BREEZY LEVEL WIND AREAS EMBEDDED IN THE GENERALLY S TO SE FLOW SUN. VENTILATION RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40 CORRIDOR. MON TO AGAIN SOME WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES IN THE EAST AND TO SOME DEGREE SOUTH...LESS WETTING RAIN POTENTIAL WITH NEAR NORMAL TEMPERATURES TO THE NW. VENTILATION NOT EXPECTED TO CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS GENERALLY ALONG AND NORTH OF I40. A DRYING TREND STILL APPEARS TO BE IN THE CARDS OVER THE AREA STARTING TUE INTO AT LEAST THU...THOUGH A WEAK FRONTAL BOUNDARY IS STILL ANTICIPATED MID WEEK AND FAVOR THE EAST SLOPES OF THE CENTRAL MTNS EASTWARD. VENTILATION IS EXPECTED TO LOWER SOME, THOUGH NOT DRASTICALLY...TUE AND WED. THE NEXT UPPER TROUGH STILL LOOKS TO APPROACH FOR LATE WEEK INTO THE FOLLOWING WEEKEND. SOME FCST MODEL DIFFERENCES REMAIN IN STRENGTH AND TIMING. GFS MODEL STILL LOOKS DEEPER AND SOMEWHAT FASTER WITH THE TROUGH THUS SOME WIND IMPACTS POSSIBLE AHEAD OF IT. THIS SHOULD IMPROVE VENTILATION RATES. ECMWF STILL IS A BIT SLOWER. MODEL DIFFERENCES STILL DRIVING DOWN CONFIDENCE SOME FOR LATE WEEK INTO NEXT WEEK. 43 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
348 AM MDT SAT SEP 20 2014 .SYNOPSIS... VERY MOIST AIR MASS TO REMAIN IN PLACE ACROSS SOUTHEAST NEW MEXICO WHERE SHOWERS AND A FEW THUNDERSTORMS ARE MOST FAVORED. DEEPER MOISTURE WILL EXPAND WESTWARD LATE TODAY AND TONIGHT...WITH SHOWER AND THUNDERSTORM ACTIVITY EXPECTED TO INCREASE AGAIN FOR PARTS OF THE EASTERN PLAINS. AN OVERALL UPTICK IN SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED FOR SUNDAY AND SUNDAY EVENING AS A DISTURBANCE ALOFT PASSES JUST NORTH OF THE STATE AND HELPS TO DRAW MOISTURE FARTHER NORTH AND WEST. DRIER AIR WILL THEN SPREAD EASTWARD INTO NORTHWEST NEW MEXICO MONDAY AND MOST AREAS TUESDAY. MEANWHILE... TEMPERATURES WILL REMAIN GENERALLY ABOVE NORMAL ACROSS THE WEST AND BELOW NORMAL ACROSS THE EAST. BY THE MIDDLE OF NEXT WEEK...A DRYING TREND WILL TAKE A STRONGER HOLD ON THE AREA...AND TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL EXCEPT FOR THE SOUTHEAST PLAINS WHERE COOLER THAN AVERAGE TEMPERATURE WILL LIKELY LINGER. && .DISCUSSION... EXTENSIVE LOW CLOUDS AND AT LEAST PATCHY DENSE FOG EAST OF THE CENTRAL MOUNTAIN CHAIN EARLY THIS MORNING. EXPECT FOG TO DEVELOP/EXPAND AND HAVE GREATEST IMPACT ALONG THE IMMEDIATE EAST SLOPES AND ALONG THE WESTERN FRINGES OF PERSISTENT STRATUS DECK. VERY MOIST AIR MASS REMAINS IN PLACE ACROSS THE SOUTHEAST PLAINS WHERE SURFACE DEW POINT TEMPS SOLIDLY IN THE MID/UPPER 60S. THUS EVEN WEAK UPSLOPE/LOW LEVEL CONVERGENCE IN THIS ENVIRON ENOUGH TO GENERATE ISOLATED ACTIVITY THIS MORNING...AND ALL INDICATIONS POINT TOWARD A GRADUAL STRENGTHENING OF THE E-SE BOUNDARY LAYER WINDS ACROSS THE PLAINS AS THE DAY PROGRESSES AND MORESO INTO THE EVENING HOURS. LATEST 13KM RAPID REFRESH /RAP/ AND HRRR MODEL RUNS CONTINUE TO SUPPORT ISO-SCT COVERAGE FOR THE EC/SE ZONES TODAY. AND GOOD AGREEMENT BETWEEN GFS/NAM SUPPORTING PREVIOUS POP/WX TRENDS INCREASING POP FOR SE 1/4 TONIGHT WITH A PREFERRED AXIS ALONG/WEST OF THE PECOS RIVER VALLEY TO EAST SLOPES OF THE SC MOUNTAINS WHERE UPSLOPE EFFECTS WILL BE MAXIMIZED. OUTSIDE THE SC MTNS AND EC/SE PLAINS...A PREDOMINATELY DRY AND UNSEASONABLY WARM FORECAST TODAY BENEATH GRADUALLY STRENGTHENING HIGH PRESSURE ALOFT THAT SHOULD CENTER NEAR OR JUST NORTH OF THE NM/CO LINE TODAY BEFORE DEFLATING AND SHIFTING EAST AND SOUTH TONIGHT- SUNDAY. THE SLIGHT AMPLIFICATION OF THE RIDGE ALOFT TODAY AND THEN TRENDS INTO SUNDAY DUE TO A CLOSED LOW FORECAST TO MOVE INTO CENTRAL CA LATE TODAY- TONIGHT THEN ACROSS THE GREAT BASIN SUNDAY. THE ONE EXCEPTION TO THE PREDOMINATELY DRY FORECAST TODAY WILL BE CATRON COUNTY/UPPER GILA REGION EXTENDING NORTH TOWARD THE ZUNI MOUNTAINS NEAR THE NM/AZ LINE WHERE MID LEVEL MOISTURE EXPECTED TO ADVECT NORTHWARD IN THE DEVELOPING S-SELY FLOW. AN EXPANSION OF ISOLATED TO SCATTERED POPS EXPECTED AREAWIDE BY SUNDAY...ESPECIALLY THE NORTH AND WEST...AS FORCING FOR LARGE- SCALE LIFT AIDS CONVECTION SUNDAY PM. SURFACE PRESSURE FALLS TO THE WEST OF THE STATE ASSOCIATED WITH THE CA LOW PRESSURE SYSTEM MOST LIKELY RESPONSIBLE FOR THE STRENGTHENING E-SELY BOUNDARY LAYER LATE TODAY AND TONIGHT. THIS WILL BRING HIGHER DEW POINT AIR WESTWARD CONTRIBUTING TO THE OVERALL IMPROVING SHRA/TSRA CHANCES. STORM MOTIONS WILL BE FAIRLY FAST BUT COULD SEE A FEW STRONG CELLS DEVELOP SUNDAY PM NW ZONES. CLOSED LOW TO OPEN UP AND PASS NORTH OF THE STATE MONDAY...WITH PROGRESSIVELY DRIER AIR MASS INTO THE FOUR CORNERS. BEST POPS FROM NE TO SW. TRANSITION TO NWLY FLOW ALOFT ON TUESDAY THAT WOULD FAVOR THE NC/NE AREAS BUT WITH RESIDUAL MOISTURE CANNOT RULE OUT ISOLATED- SCATTERED SHRA/TSRA ACROSS THE EAST AND SOUTH. DEFINITE DRYING TREND NC/NW ZONES. FOR WED AND BEYOND...ANOTHER DEEP TROUGH INDICATED INTO THE WEST COAST LATE NEXT WEEK BUT MUCH UNCERTAINTY ON HOW QUICKLY IT WILL PROGRESS EAST. FARTHER DOWNSTREAM OVER OUR REGION... POSITIVELY TILTED UPPER RIDGE MOST LIKELY TO DOMINATE WITH A DEFORMATION AXIS OF SOME SORTS STRETCHING FROM THE CENTRAL PLAINS STATES INTO FAR EASTERN NM BUT LOW CONFIDENCE. LOW GRADE POP FORECAST IN PLACE FOR NOW WITH TEMPS GENERALLY BELOW NORMAL EAST...AND NEAR TO SLIGHTLY ABOVE WEST. KJ && .FIRE WEATHER... UPPER LOW NEAR THE CENTRAL TO S CALIFORNIA COAST TO BE AN IMPORTANT DRIVER IN LOWERING SFC PRESSURE OVER OR JUST W OF W NM WHICH WILL SHIFT WINDS TO SOMEWHAT OF AN EASTERLY COMPONENT ACROSS MOST OF THE EAST TWO THIRDS OR THREE QUARTERS OF NM BY LATE AM TO EARLY PM TODAY. SOME DRYING THANKS TO A MODERATE MID LEVEL DRY INTRUSION EXPECTED MAINLY ACROSS WESTERN AREAS. THE BEST CHANCE OF WETTING RAIN TO BE FOUND ACROSS THE SE AND ALSO MUCH OF THE HIGHER TERRAIN ELSEWHERE. GAP WIND GUSTS RANGING FROM 30 TO 40 MPH WILL BE EXPECTED ALONG THE RIO GRANDE VALLEY TONIGHT INTO SUN MORNING. RESIDUAL SFC MOISTURE AND MID TO UPPER LVL FLOW SHIFTING FROM E AND NE TODAY TO MORE OF A SE TO S FLOW SUN TO SUN NIGHT PERIOD. THIS SHOULD HELP ENHANCE WETTING RAIN POTENTIAL FOR SUN...FAVORING MOST THE CENTRAL MTN CHAIN AND EAST AS WELL AS AREAS NEAR TO WEST OF THE DIVIDE. AFTN TEMPS SHOULD BE WILL COOL ROUGHLY 5 TO 10 DEGREES MOST SPOTS EXCEPT PERHAPS A BIT LESS SO ACROSS FAR E NM...BUT REMAIN NEAR NORMAL ACROSS ROUGHLY THE NE HALF OF THE STATE. SOME BREEZY LEVEL WIND AREAS EMBEDDED IN THE GENERALLY S TO SE FLOW SUN. VENTILATION RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40 CORRIDOR. MON TO AGAIN SOME WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES IN THE EAST AND TO SOME DEGREE SOUTH...LESS WETTING RAIN POTENTIAL WITH NEAR NORMAL TEMPERATURES TO THE NW. VENTILATION NOT EXPECTED TO CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS GENERALLY ALONG AND NORTH OF I40. A DRYING TREND STILL APPEARS TO BE IN THE CARDS OVER THE AREA STARTING TUE INTO AT LEAST THU...THOUGH A WEAK FRONTAL BOUNDARY IS STILL ANTICIPATED MID WEEK AND FAVOR THE EAST SLOPES OF THE CENTRAL MTNS EASTWARD. VENTILATION IS EXPECTED TO LOWER SOME, THOUGH NOT DRASTICALLY...TUE AND WED. THE NEXT UPPER TROUGH STILL LOOKS TO APPROACH FOR LATE WEEK INTO THE FOLLOWING WEEKEND. SOME FCST MODEL DIFFERENCES REMAIN IN STRENGTH AND TIMING. GFS MODEL STILL LOOKS DEEPER AND SOMEWHAT FASTER WITH THE TROUGH THUS SOME WIND IMPACTS POSSIBLE AHEAD OF IT. THIS SHOULD IMPROVE VENTILATION RATES. ECMWF STILL IS A BIT SLOWER. MODEL DIFFERENCES STILL DRIVING DOWN CONFIDENCE SOME FOR LATE WEEK INTO NEXT WEEK. 43 && .AVIATION... 06Z TAF CYCLE IFR CIGS WORKING INTO THE EASTERN PLAINS OVERNIGHT AND IN TAFS FOR TCC...ROW...AND LVS. RIDGE BUILDING NORTHWARD ACROSS NM IN THE WAKE OF ODILE...AS SURFACE LOW OVER NORTHERN MEXICO IMPARTS EASTERLY COMPONENTS TO SURFACE WINDS THROUGH THE DAY ON SATURDAY. GUSTS SQUIRTING THROUGH CENTRAL MT CHAIN GAPS OVER THE RIO GRANDE VALLEY REFLECTED IN G30KT WINDS AT ABQ AND SAF FROM 01Z ONWARD SAT EVENING. NEXT APPROACHING SYSTEM OVER CENTRAL CALIFORNIA WILL SUPPORT SOME ISOLATED SHOWERS DRIFTING INTO WESTERN NEW MEXICO AND IN TAFS FOR GUP AND FMN. OVERNIGHT MT OBSCURATION OVER THE NORTHERN MTS AND ACROSS THE SOUTHERN TIER LATE SAT NIGHT. SHY && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 88 60 85 56 / 5 30 30 40 DULCE........................... 87 49 80 47 / 10 30 40 50 CUBA............................ 84 51 78 51 / 10 20 40 40 GALLUP.......................... 85 51 80 48 / 10 30 40 40 EL MORRO........................ 79 50 75 49 / 10 30 40 50 GRANTS.......................... 83 54 78 52 / 10 30 40 40 QUEMADO......................... 79 53 75 52 / 20 30 50 40 GLENWOOD........................ 83 52 82 54 / 30 30 30 30 CHAMA........................... 80 43 75 42 / 10 30 40 60 LOS ALAMOS...................... 81 57 74 55 / 10 20 40 40 PECOS........................... 77 53 69 52 / 10 30 50 50 CERRO/QUESTA.................... 78 48 75 48 / 10 20 40 40 RED RIVER....................... 71 44 66 44 / 10 30 50 50 ANGEL FIRE...................... 74 38 70 41 / 10 30 50 50 TAOS............................ 81 50 73 49 / 10 20 30 40 MORA............................ 77 50 68 50 / 10 30 50 50 ESPANOLA........................ 86 55 79 55 / 10 20 30 30 SANTA FE........................ 80 55 74 55 / 10 20 40 40 SANTA FE AIRPORT................ 84 55 77 55 / 10 20 40 30 ALBUQUERQUE FOOTHILLS........... 84 61 78 61 / 10 20 40 30 ALBUQUERQUE HEIGHTS............. 85 63 80 62 / 10 20 30 30 ALBUQUERQUE VALLEY.............. 86 60 81 61 / 10 20 30 30 ALBUQUERQUE WEST MESA........... 87 61 82 61 / 10 20 30 30 LOS LUNAS....................... 86 58 81 58 / 10 20 30 30 RIO RANCHO...................... 89 61 83 61 / 10 20 30 30 SOCORRO......................... 86 62 83 62 / 10 30 40 40 SANDIA PARK/CEDAR CREST......... 82 57 78 57 / 10 30 40 40 TIJERAS......................... 83 57 78 57 / 10 30 40 40 MORIARTY/ESTANCIA............... 81 49 74 50 / 10 30 50 40 CLINES CORNERS.................. 77 54 70 54 / 10 40 60 50 GRAN QUIVIRA.................... 78 57 71 57 / 20 40 50 40 CARRIZOZO....................... 81 60 74 60 / 20 40 50 30 RUIDOSO......................... 74 54 70 54 / 20 50 60 50 CAPULIN......................... 77 53 70 52 / 10 20 30 30 RATON........................... 82 52 76 52 / 10 20 40 30 SPRINGER........................ 83 53 74 54 / 10 30 40 30 LAS VEGAS....................... 78 52 71 52 / 10 40 60 50 CLAYTON......................... 82 59 77 57 / 10 20 30 30 ROY............................. 79 56 73 56 / 10 30 40 50 CONCHAS......................... 82 62 78 62 / 20 40 40 50 SANTA ROSA...................... 80 61 74 61 / 20 50 50 50 TUCUMCARI....................... 83 63 80 62 / 20 30 40 40 CLOVIS.......................... 77 62 76 61 / 40 40 50 50 PORTALES........................ 78 62 77 62 / 40 40 50 50 FORT SUMNER..................... 81 62 75 62 / 20 50 50 50 ROSWELL......................... 80 65 78 64 / 20 50 60 50 PICACHO......................... 77 59 71 60 / 20 50 60 50 ELK............................. 73 56 68 57 / 30 50 60 60 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 41
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1128 PM MDT FRI SEP 19 2014 .AVIATION... 06Z TAF CYCLE IFR CIGS WORKING INTO THE EASTERN PLAINS OVERNIGHT AND IN TAFS FOR TCC...ROW...AND LVS. RIDGE BUILDING NORTHWARD ACROSS NM IN THE WAKE OF ODILE...AS SURFACE LOW OVER NORTHERN MEXICO IMPARTS EASTERLY COMPONENTS TO SURFACE WINDS THROUGH THE DAY ON SATURDAY. GUSTS SQUIRTING THROUGH CENTRAL MT CHAIN GAPS OVER THE RIO GRANDE VALLEY REFLECTED IN G30KT WINDS AT ABQ AND SAF FROM 01Z ONWARD SAT EVENING. NEXT APPROACHING SYSTEM OVER CENTRAL CALIFORNIA WILL SUPPORT SOME ISOLATED SHOWERS DRIFTING INTO WESTERN NEW MEXICO AND IN TAFS FOR GUP AND FMN. OVERNIGHT MT OBSCURATION OVER THE NORTHERN MTS AND ACROSS THE SOUTHERN TIER LATE SAT NIGHT. SHY && .PREV DISCUSSION...743 PM MDT FRI SEP 19 2014... .UPDATE... UPDATED FORECAST TO LOWER PRECIPITATION CHANCES OVERNIGHT. MODELS CONTINUE TO GENERATE LOTS OF QPF BUT SATELLITE AND RADAR IMAGERY INDICATING NOT MUCH MORE THAN A FEW SHOWERS AND STORMS REMAIN OVER SERN NM. INTERESTINGLY...A SMALL CLUSTER OF CONVECTION OVER THE SOUTHERN SAN JUAN MOUNTAINS IN COLORADO CONTINUES TO DRIFT SWED TOWARD THE CHAMA AREA. LEFT IN ISOLATED STORMS THROUGH THE EVENING ALONG/NEAR THE COLORADO BORDER IN NORTH-CENTRAL NM AS A RESULT. 33 && .PREV DISCUSSION...308 PM MDT FRI SEP 19 2014... .SYNOPSIS... SHOWERS AND PERHAPS A THUNDERSTORM WILL CONTINUE THIS EVENING AND OVERNIGHT ACROSS PORTIONS OF THE EASTERN PLAINS. THOUGH THE DAYTIME HOURS ON SATURDAY SHOULD BE MOSTLY QUIET...AS MOISTURE MOVES BACK INTO THE AREA FROM THE SOUTH AND EAST...SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO RAMP BACK UP AGAIN SATURDAY NIGHT AND SUNDAY. DRIER AIR WILL MOVE INTO THE STATE FROM WEST TO EAST MONDAY AND TUESDAY. MEANWHILE...TEMPERATURES WILL REMAIN GENERALLY ABOVE NORMAL ACROSS THE WEST AND BELOW NORMAL ACROSS THE EAST. BY THE MIDDLE OF NEXT WEEK...STORM COVERAGE WILL BE DWINDLING...AND TEMPERATURES WILL REBOUND WITHIN A FEW DEGREES OF NORMAL AREA WIDE. && .DISCUSSION... RADAR AND OBSERVATIONS CONTINUE TO SHOW THAT MODELS ARE STRUGGLING WITH QPF PLACEMENT AND AMOUNTS WITH THE REMNANTS OF ODILE. THIS IS MAINLY BECAUSE ODILE CONTINUES TO STAY SOUTH OF PROJECTED TRACKS. INTERESTINGLY...MOST OPERATIONAL MODELS CONTINUE TO SHOW QPF BULLS- EYES OVER PORTIONS OF THE EASTERN PLAINS THRU THE OVERNIGHT...BUT THE LATEST HRRR HAS TAKEN THE OPPOSITE TUNE...WITH ALMOST NO PRECIP PREDICTED. EXPECT REALITY TO BE CLOSER TO THE DRIER SCENARIO...THOUGH SOME SHOWERS SHOULD PERCOLATE OVERNIGHT ACROSS THE PLAINS...MUCH LIKE WHAT IS OCCURRING NOW. HAVE ALSO LEFT IN ISOLATED THUNDER...BUT NOT CONFIDENT MUCH OF THAT WILL HAPPEN. AS ODILE CONTINUES TO SHIFT EASTWARD AND LOSE ITS IDENTITY...ITS POOL OF MOISTURE WILL REMAIN OVER WEST TEXAS ON SATURDAY. MEANWHILE...THE NEXT UPPER LOW WILL TAKE SHAPE OFF THE COAST OF CALI...AND A WEAK UPPER HIGH WILL BEGIN TO BUILD OVER NM. AS A RESULT...LOW TO MID LEVEL FLOW WILL BECOME EASTERLY. THOUGH THE DAYTIME HOURS SHOULD BE RELATIVELY QUIET IN TERMS OF CONVECTION...AS THE POOL OF MOISTURE IS ADVECTED WESTWARD INTO THE PLAINS...UP SLOPE FLOW SHOULD ALLOW FOR SHOWERS AND PERHAPS SOME THUNDERSTORMS TO DEVELOP LATE IN THE AFTN AND EVENING. SHOULD ALSO SEE AN EAST CANYON WIND PICK UP IN THE RIO GRANDE VALLEY WITH BREEZY TO WINDY CONDITIONS EXPECTED. SUNDAY CONTINUES TO TREND TOWARD MORE WIDESPREAD PRECIPITATION AS THE UPPER LOW EJECTS NEWD OVER THE GREAT BASIN AND LOW/MID LEVEL MOISTURE CONTINUES TO BE ADVECTED INTO NM FROM THE S AND SE. INCREASED POPS AREA WIDE...THOUGH GENERALLY STAY A BIT CONSERVATIVE. WESTERLY FLOW WILL RETURN ON MONDAY...GENERALLY AT THE BASE OF THE TROUGH/LOW MOVING ACROSS THE CENTRAL/NORTHERN ROCKIES. DRIER AIR WILL START TO MOVE INTO THE NW BUT STILL A FAIR AMOUNT OF SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED ELSEWHERE. THE TROUGH AXIS WILL PASS MONDAY NIGHT...AND FLOW WILL BECOME MORE NORTHWESTERLY. THIS SHOULD TEMPORARILY HALT ANY MONSOONAL MOISTURE FROM MOVING NORTHWARD. A WEAK UPPER HIGH WILL DEVELOP OVER NM FOR THE MIDDLE TO LATTER HALF OF THE WORK WEEK...THOUGH ENOUGH MOISTURE SHOULD BE AROUND TO SUPPORT A FEW STORMS. THE 12Z GFS AND LAST NIGHTS ECMWF BOTH SHOW A LARGE TROUGH MOVING INTO THE WESTERN US NEXT FRIDAY THRU THE WEEKEND. THIS SCENARIO WOULD BRING UP ANOTHER BOUT OF MONSOONAL MOISTURE FOR NM NEXT WEEKEND. HOWEVER...THE 12Z ECMWF DOES NOT SHOW THE TROUGH AS FAR SOUTH...THUS NOT AS MUCH MOISTURE ADVECTION NORTHWARD. STAY TUNED. 34 && .FIRE WEATHER... REMNANTS OF ODILE WILL KEEP HIGH HUMIDITY AND SCATTERED SHOWERS WITH WETTING RAIN REST OF THE AFTERNOON INTO TONIGHT FOR AREAS EAST OF THE CENTRAL MOUNTAIN CHAIN. EASTERLY FLOW WILL RETURN ACROSS THE EASTERN PLAINS SATURDAY INCREASING LOW LEVEL RH ACROSS THE NORTHEAST HALF. DRYING VIA A MID LEVEL DRY INTRUSION EXPECTED ELSEWHERE...ESPECIALLY WESTERN AREAS. THE BEST CHANCE OF WETTING RAIN WOULD BE FOUND ACROSS THE SOUTHEAST. GAP WIND GUSTS RANGING FROM 30 TO 45 MPH WILL BE EXPECTED ALONG THE RIO GRANDE VALLEY SATURDAY EVENING INTO EARLY SUNDAY MORNING. RESIDUAL MOISTURE AND A MODERATELY STRONG UPPER LEVEL LOW TO OUR WEST WILL ENHANCE WETTING RAIN POTENTIAL AREA WIDE FOR SUNDAY. GREATEST EMPHASIS ACROSS SOUTH CENTRAL AND SOUTHEAST AREAS. TEMPERATURES WILL COOL 5 TO 10 DEGREES AREA WIDE BUT REMAIN NEAR NORMAL ACROSS THE NORTHWESTERN HALF OF THE STATE. EASTERLY WINDS WILL CONTINUE TO BE BREEZY. VENTILATION RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40 CORRIDOR. MONDAY WILL STILL SEE WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES IN THE EAST...LESS WETTING RAIN POTENTIAL WITH NEAR NORMAL TEMPERATURES TO THE WEST. VENTILATION NOT EXPECTED TO CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS ALONG AND NORTH OF I40. MODELS REMAIN CONSISTENT WITH DEVELOPING A DRYING TREND OVER THE AREA STARTING TUESDAY ALTHOUGH A WEAK FRONTAL BOUNDARY IS STILL ANTICIPATED MID WEEK AND FAVOR THE EAST SLOPES OF THE CENTRAL MTNS EASTWARD. VENTILATION IS EXPECTED TO LOWER SOME TUESDAY/WEDNESDAY BUT NOT FALL OUT OF SIGHT. MODELS COULD IMPROVE THE NUMBERS AS WE GET CLOSER TO THAT PERIOD. THE NEXT UPPER TROUGH STILL ON TAP FOR LATE WEEK INTO THE FOLLOWING WEEKEND. MODELS REMAIN A LITTLE DIFFERENT IN TERMS OF TIMING AND STRENGTH OF IMPACTS. THE GFS IS MUCH DEEPER AND MORE PROGRESSIVE WITH THE TROUGH THUS SOME WIND IMPACTS POSSIBLE AHEAD OF IT. THIS IMPACTS VENTILATION RATES. ECMWF IS A BIT SLOWER. LOWER CONFIDENCE PERIOD FOR LATE WEEK INTO NEXT WEEK AT THIS TIME. 32/50 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1009 AM EDT SAT SEP 20 2014 .SYNOPSIS... HIGH PRESSURE OFF THE COAST OF NEW ENGLAND WILL BRING MILD...DRY AND GUSTY CONDITIONS TO THE REGION TODAY. AS LOW PRESSURE APPROACHES FROM THE WEST THERE WILL BE AN INCREASING CHANCE OF SHOWERS LATER TONIGHT...WITH WIDESPREAD SHOWER DEVELOPING ON SUNDAY AS A COLD FRONT SWEEPS THROUGH THE REGION. THIS FRONT WILL CLEAR THE AREA DURING MONDAY WITH SOME LINGERING SHOWERS ACROSS THE HIGHER TERRAIN THROUGH MID-DAY...THEN IT LOOKS AS IF WE WILL BE IN FOR AN EXTENDED PERIOD OF DRY WEATHER NEXT WEEK AS A LARGE UPPER RIDGE BUILDS EAST FROM THE MIDWEST. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1008 AM EDT SATURDAY...PRIMARY CHANGES WITH THIS UPDATE WAS TO OFFER A MORE PESSIMISTIC FORECAST FOR SOUTHERN/EASTERN VT...WITH UPWARD ADJUSTMENTS TO SKY COVER FOR MUCH OF THE AFTN HOURS AND ACCORDINGLY LOWERED HIGHS IN THIS GENERAL AREA. STILL SHAPING UP TO BE A BREEZY SATURDAY WITH STRONG SOUTHERLY PRESSURE GRADIENT IN PLACE. OVERCAST SKIES THAT ADVECTED NORTHEASTWARD OVERNIGHT STILL CONTINUES TO PLAGUE MOST OF THE NORTH COUNTRY THIS MORNING PER VISIBLE IMAGERY. A NARROW AXIS OF "CLEARING"/PARTLY CLOUDY SKIES EXTENDED ACROSS THE ST. LAWRENCE VALLEY...FAR NORTHERN CHAMPLAIN VALLEY INTO THE NORTHERN GREENS. STRONG LOW- LEVEL SOUTH/SOUTHEAST FLOW HELPING TO MAINTAIN LOWER MOISTURE AND THINK THIS WILL CONTINUE TO BE THE GENERAL IDEA FOR TODAY. LATEST RAP 0-1KM RH PROGS SUGGEST OVERCAST WILL BE VERY SLOW TO LIFT ACROSS INTERIOR CENTRAL AND SOUTHERN VT TODAY. HIGHS MAY STRUGGLE TO REACH THE MID 60S. THAT CONTRASTS WITH EXPECTED CONDITIONS FOR ST. LAWRENCE AND NORTHERN CHAMPLAIN VALLEYS AS MORE BREAKS IN CLOUDS WILL ALLOW HIGHS TO RANGE FROM THE UPPER 60S TO MID 70S. && .SHORT TERM /7 PM THIS EVENING THROUGH MONDAY/... AS OF 408 AM EDT SATURDAY...DRY CONDITIONS CONTINUE INTO TONIGHT AS LOW PRESSURE OVER THE GREAT LAKES SHIFTS NORTHEASTWARD INTO CENTRAL QUEBEC BY 12Z SUNDAY. ATTENDING SURFACE COLD FRONT RUNS PARALLEL TO THE UPPER FLOW FROM THE SOUTHWEST SO THE ASSOCIATED PRECIP WILL TAKE AWHILE TO SHIFT EASTWARD INTO THE BTV CWA...LIKELY REACHING THE ST. LAWRENCE VALLEY RIGHT AROUND DAYBREAK. WITH INCREASING CLOUDS AND CONTINUED GUSTY WINDS...OVERNIGHT TEMPS WILL BE RATHER MILD WITH LOWS ONLY IN THE MID 50S TO LOWER 60S...QUITE A DIFFERENCE FROM FRIDAY MORNING! PRECIP SHIFTS INTO NORTHERN NEW YORK SUNDAY MORNING BUT NOT INTO THE CHAMPLAIN VALLEY AND EASTERN VERMONT UNTIL AFTER 18Z. SO FOR SOME...SUNDAY MORNING WILL BE GENERALLY DRY...MAINLY ACROSS VERMONT...BUT NOT SO MUCH FOR PEOPLE LIVING IN NORTHERN NEW YORK. HIGH TEMPS ARE A LITTLE TRICKY SUNDAY AND WILL LARGELY DEPEND ON TIMING OF THE FRONT AND ASSOCIATED PRECIP AND CLOUDS. HIGHS WILL PUSH A FEW DEGREES WARMER THAN THE PREVIOUS DAY ACROSS VT IN THE LOW TO MID 70S...WHILE WESTWARD IN CLOUDS AND PRECIP THEY`LL HOLD IN THE UPPER 60S. COLD FRONT AND ASSOCIATED PRECIP SHIFT EAST THROUGH THE REGION SUNDAY NIGHT BUT THE PARENT UPPER LOW LAGS BEHIND...NOT MOVING THROUGH UNTIL MONDAY AFTERNOON. WITH LINGERING LOW LEVEL MOISTURE AND LOW/MID LEVEL FLOW TURNING TO THE NORTHWEST FEEL WE`LL SEE SOME UPSLOPE ENHANCEMENT TO PRECIP ALONG THE SPINE OF THE GREENS AND NORTHERN DACKS MONDAY...WHILE DOWNSLOPE AREAS WILL LIKELY REMAIN DRY. BY LATE AFTERNOON AND INTO THE EVENING THOUGH...HIGH PRESSURE BEGINS TO SHIFT INTO THE GREAT LAKES REGION AND LOW/MID LEVELS BEGIN TO DRY OUT ACROSS THE BTV CWA SUBSEQUENTLY ENDING PRECIP. HIGHS MONDAY WILL BE BACK BELOW NORMAL POST FRONTAL PASSAGE...AND GENERALLY RUN IN THE 50S EXCEPT FOR THE LOWER CONNECTICUT RIVER VALLEY WHICH WILL BE IN THE LOW TO MID 60S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 301 AM EDT SATURDAY...A SIGNIFICANT PATTERN CHANGE IS EXPECTED DURING THE LONG-TERM PERIOD WITH A TREND TOWARD TRANQUIL WEATHER WITH TEMPERATURES ABOVE SEASONAL AVERAGES. GOOD RUN-TO-RUN CONSISTENCY CONTINUES TO BE OBSERVED IN THE 00Z OPERATIONAL GFS AND ECMWF. A LINGERING MID-LEVEL TROUGH/CYCLONIC FLOW EARLY IN THE PERIOD WILL BRING PARTLY TO MOSTLY CLOUDY CONDITIONS WITH A SLIGHT CHANCE OF A RAIN SHOWER MONDAY NIGHT INTO TUESDAY. THE HIGHEST POPS (~25%) ARE ACROSS THE NORTHERN MOUNTAINS DURING THE DAY TUESDAY...WITH DEVELOPMENT OF WEAK DAYTIME INSTABILITY. ANY PRECIPITATION WILL BE LIGHT. THEREAFTER...AN AMPLIFYING DEEP-LAYER RIDGE BUILDS EWD FROM THE MIDWEST AND GREAT LAKES PROVIDING GENERALLY CLEAR SKIES. WILL SEE HIGHS IN THE MID 60S WEDNESDAY...AND THEN INTO THE LOW- MID 70S IN THE VALLEYS ON THURSDAY AND FRIDAY AS AIR MASS MODERATES. RELATIVELY LIGHT WINDS ARE EXPECTED AS WELL. CLEAR SKIES/LIGHT WINDS WILL LEAD TO SOME LOCAL NOCTURNAL FOG IN THE FAVORED RIVER VALLEYS EACH NIGHT FROM TUESDAY NIGHT THROUGH THURSDAY NIGHT. COLDEST LOW TEMPERATURES WILL BE TUESDAY NIGHT...GENERALLY IN THE UPPER 30S TO LOWER 40S. THEREAFTER...LOWS WILL GENERALLY BE IN THE MID-UPPER 40S IN MOST SECTIONS. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... THROUGH 12Z SUNDAY...AREAS OF MVFR CEILINGS EXPECTED THIS MORNING AT SLK/RUT/MPV ASSOCIATED WITH STRATUS DECK. THESE CLOUDS WILL TEND TO LIFT TO VFR BY 15-16Z WITH BETTER LOW-LEVEL MIXING. WINDS WILL BE INCREASING FROM THE SOUTH TO SOUTHWEST...ESPECIALLY DURING THE DAYLIGHT HOURS WITH INCREASING PRESSURE GRADIENT. WILL ALSO BE DEALING WITH LOW-LEVEL WIND SHEAR AT PBG/SLK UNTIL LOW- LEVELS MIX OUT AFTER 14-15Z THIS MORNING. INCLUDED LLWS IN THE TAFS AT ABOVE MENTIONED TAF SITES NEXT FEW HRS...WITH STRONGEST SHEAR BETWEEN 1.5-2 KFT AGL. VFR THIS AFTERNOON. COULD SEE SOME ADDITIONAL STRATUS/3-5SM BR OVERNIGHT WITH PERIODS OF MVFR CONDITIONS. OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...FRONTAL SYSTEM MOVING IN FROM THE WEST WILL BRING POTENTIAL FOR WIDELY SCATTERED RAIN SHOWERS DURING THE DAY SUNDAY...WITH PERIODS OF MVFR CEILINGS AND VSBYS. UPPER TROUGH REMAINS IN PLACE WITH POTENTIAL FOR SCATTERED SHOWERS SUNDAY NIGHT INTO MONDAY. MAY SEE SOME PERIODS OF CONTINUING MVFR CEILINGS DURING SUN NIGHT AND MONDAY. GENERALLY TRENDING VFR MONDAY NIGHT ONWARD WITH DEVELOPING STRONG SURFACE AND UPPER RIDGE BY MID-WEEK ACROSS THE GREAT LAKES AND NEW ENGLAND. && .MARINE... AS OF 408 AM EDT SATURDAY...STRONG SOUTH WINDS WILL CONTINUE ACROSS LAKE CHAMPLAIN TODAY AND RIGHT INTO SUNDAY MORNING WITH HIGH PRESSURE TO OUR EAST AND LOW PRESSURE APPROACHING FROM THE WEST. SPEEDS OF 20 TO 30 KNOTS ARE EXPECTED DURING THIS TIME PERIOD WITH GUSTS AS HIGH AS 35 KNOTS AT TIMES. WAVES WILL BUILD INTO THE 2 TO 5 FOOT RANGE MAKING FOR ROUGH BOATING CONDITIONS FOR A GOOD PART OF THE WEEKEND. AS A RESULT...A LAKE WIND ADVISORY REMAINS IN EFFECT THROUGH AT LEAST SUNDAY MORNING. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...LAHIFF NEAR TERM...LAHIFF/LOCONTO SHORT TERM...LAHIFF LONG TERM...BANACOS AVIATION...BANACOS MARINE...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
303 AM EDT SAT SEP 20 2014 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BRING DRY WEATHER TO THE NORTH COUNTRY TONIGHT...BUT TEMPERATURES WILL NOT BE AS COLD AS LAST NIGHT. LOOKING FOR WARMER...WINDIER...AND WETTER CONDITIONS THIS WEEKEND. HIGHS SATURDAY AND SUNDAY WILL BE IN THE 60S TO LOWER 70S. WINDS WILL BE INCREASING DURING THE DAY ON SATURDAY WITH GUSTS IN THE 30 TO 40 MPH RANGE. EVENTUALLY RAIN WILL MOVE IN LATE SATURDAY NIGHT AND ESPECIALLY THROUGHOUT THE DAY ON SUNDAY WITH WIDESPREAD RAIN EXPECTED SUNDAY AFTERNOON AND NIGHT. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1027 PM EDT FRIDAY...MINOR ADJUSTMENTS TO HOURLY T/TD DATA AS OF THE 10 O`CLOCK HOUR TO ACCOUNT FOR CURRENT OBSERVATIONAL TRENDS. SOUTHERLY RETURN FLOW HAS COMMENCED WITH SOME AREAS...PARTICULARLY THE CHAMPLAIN AND ST LAWRENCE VALLEYS HAVING LIKELY ALREADY EXPERIENCED THEIR OVERNIGHT LOWS AS READINGS SLOWLY CLIMB OVERNIGHT. OTHER AREAS HAVE DECOUPLED SO MORE OF A TYPICAL DIURNAL TREND EXPECTED...NAMELY ERN VT AND PORTIONS OF THE ADIRONDACKS. CASE IN POINT TRUSTY SARANAC LAKE ALREADY AT THE FREEZING MARK. HAVE A GREAT NIGHT. PRIOR DISCUSSION FOLLOWS... PRIOR DISCUSSION... FORECAST REMAINS IN GOOD SHAPE AS WE PROGRESS INTO THE EVENING HOURS. CLEAR SKIES WILL GRADUALLY GIVE WAY TO SOME HIGH CLOUDS (ESPECIALLY NORTH) OVERNIGHT AS SURFACE HIGH PRESSURE SLIDES OFFSHORE AS SOUTH/SOUTHWESTERLY RETURN FLOW BEGINS IN EARNEST ALOFT...NOT AS MUCH AT THE SURFACE. NONETHELESS READINGS WILL BE MILDER TONIGHT THAN LAST NIGHT GIVEN WARM THERMAL RESPONSE THROUGH THE 925-850 MB LEVEL. STUCK CLOSE TO LATEST RAP 500 MB RH PROGS WHICH APPEARS TO BE HANDLING THICKER MID LEVEL CLOUDS OFF TO OUR NORTH...AND ITS SUBSEQUENT PROGRESSION RATHER WELL THIS EVENING. LOWS REMAIN ON TRACK...RANGING FROM THE MID TO UPPER 30S IN ERN VT...UPPER 30S TO LOWER 40S DACKS...AND SOLIDLY IN THE 40S FOR THE CHAMPLAIN AND ST LAWRENCE VALLEYS. && .SHORT TERM /8 AM THIS MORNING THROUGH MONDAY/... AS OF 336 PM EDT FRIDAY...PRESSURE GRADIENT WILL CONTINUE TO STRENGTHEN FROM THE SOUTH AND SOUTHWEST DURING THE DAY ON SATURDAY. WHILE THIS WILL PROMOTE LOW LEVEL WARM AIR ADVECTION...BREEZY TO WINDY CONDITIONS WILL DEVELOP. SO WHILE HIGHS WILL BE IN THE MID 60S TO THE LOWER 70S...THE WINDS WILL NOT ALLOW FOR IT TO FEEL THAT WARM WITH GUSTS IN THE 25 TO 35 MPH RANGE AND EVEN SOME 40 MPH GUSTS IN THE SAINT LAWRENCE VALLEY. DRY WEATHER IS EXPECTED DURING THE DAY ON SATURDAY...BUT THAT WILL CHANGE AS AN UPPER LEVEL TROUGH OF LOW PRESSURE DEVELOPS OVER THE UPPER MIDWEST. THIS FEATURE WILL BEGIN TO SHARPEN UP SATURDAY NIGHT WHICH WILL ULTIMATELY SLOW THE ONSET OF THE PRECIPITATION DOWN. CAN SEE A CHANCE OF SHOWERS LATE SATURDAY NIGHT OVER NORTHERN NEW YORK...BUT THE STEADIER AND MORE WIDESPREAD SHOWERS WILL NOT MOVE INTO THE ENTIRE AREA UNTIL LATER SUNDAY MORNING THROUGH SUNDAY NIGHT. THE CLOUDS AND GUSTY WINDS SATURDAY NIGHT WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL...SO IT WILL NOT TAKE MUCH ON SUNDAY FOR HIGHS TO GET RIGHT BACK INTO THE MID 60S TO LOWER 70S. THE UPPER TROUGH WILL BE SLOW TO MOVE EAST OF THE AREA SUNDAY NIGHT...SO SHOWERS SHOULD BE FAIRLY WIDESPREAD SUNDAY EVENING BEFORE GRADUALLY TAPERING OFF AFTER MIDNIGHT. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 301 AM EDT SATURDAY...A SIGNIFICANT PATTERN CHANGE IS EXPECTED DURING THE LONG-TERM PERIOD WITH A TREND TOWARD TRANQUIL WEATHER WITH TEMPERATURES ABOVE SEASONAL AVERAGES. GOOD RUN-TO-RUN CONSISTENCY CONTINUES TO BE OBSERVED IN THE 00Z OPERATIONAL GFS AND ECMWF. A LINGERING MID-LEVEL TROUGH/CYCLONIC FLOW EARLY IN THE PERIOD WILL BRING PARTLY TO MOSTLY CLOUDY CONDITIONS WITH A SLIGHT CHANCE OF A RAIN SHOWER MONDAY NIGHT INTO TUESDAY. THE HIGHEST POPS (~25%) ARE ACROSS THE NORTHERN MOUNTAINS DURING THE DAY TUESDAY...WITH DEVELOPMENT OF WEAK DAYTIME INSTABILITY. ANY PRECIPITATION WILL BE LIGHT. THEREAFTER...AN AMPLIFYING DEEP-LAYER RIDGE BUILDS EWD FROM THE MIDWEST AND GREAT LAKES PROVIDING GENERALLY CLEAR SKIES. WILL SEE HIGHS IN THE MID 60S WEDNESDAY...AND THEN INTO THE LOW- MID 70S IN THE VALLEYS ON THURSDAY AND FRIDAY AS AIR MASS MODERATES. RELATIVELY LIGHT WINDS ARE EXPECTED AS WELL. CLEAR SKIES/LIGHT WINDS WILL LEAD TO SOME LOCAL NOCTURNAL FOG IN THE FAVORED RIVER VALLEYS EACH NIGHT FROM TUESDAY NIGHT THROUGH THURSDAY NIGHT. COLDEST LOW TEMPERATURES WILL BE TUESDAY NIGHT...GENERALLY IN THE UPPER 30S TO LOWER 40S. THEREAFTER...LOWS WILL GENERALLY BE IN THE MID-UPPER 40S IN MOST SECTIONS. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... THROUGH 12Z SUNDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD...THOUGH THERE WILL BE AN INCREASE IN MID-UPPER LEVEL CLOUDS THROUGH THE DAYLIGHT HOURS AREAWIDE. ALSO WATCHING SOME DEVELOPING STRATUS ACROSS E-CENTRAL NY...WHICH WILL IMPACT RUT/MPV AT TIMES THIS MORNING WITH SCT-BKN040-050. NO PRECIPITATION IS EXPECTED THROUGH THE PERIOD. WINDS WILL BE INCREASING FROM THE SOUTH TO SOUTHWEST...ESPECIALLY DURING THE DAYLIGHT HOURS WITH INCREASING PRESSURE GRADIENT. AT BTV...WINDS ALREADY 10KTS AND WILL INCREASE TO 15G25KT AFTER 13-14Z. WILL ALSO BE DEALING WITH LOW-LEVEL WIND SHEAR AT PBG/MSS/SLK UNTIL LOW-LEVELS MIX OUT AFTER 12Z THIS MORNING. INCLUDED LLWS IN THE TAFS AT ABOVE MENTIONED TAF SITES THIS MORNING...WITH STRONGEST SHEAR BETWEEN 1.5-2 KFT AGL. OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...FRONTAL SYSTEM MOVING IN FROM THE WEST WILL BRING POTENTIAL FOR WIDELY SCATTERED RAIN SHOWERS DURING THE DAY SUNDAY...WITH PERIODS OF MVFR CEILINGS AND VSBYS. UPPER TROUGH REMAINS IN PLACE WITH POTENTIAL FOR SCATTERED SHOWERS SUNDAY NIGHT INTO MONDAY. MAY SEE SOME PERIODS OF CONTINUING MVFR CEILINGS DURING SUN NIGHT AND MONDAY. GENERALLY TRENDING VFR MONDAY NIGHT ONWARD WITH DEVELOPING STRONG SURFACE AND UPPER RIDGE BY MID-WEEK ACROSS THE GREAT LAKES AND NEW ENGLAND. && .MARINE... STRONG SOUTH TO SOUTHWEST WINDS WILL DEVELOP AFTER MIDNIGHT TONIGHT AND CONTINUE RIGHT INTO SUNDAY MORNING. SPEEDS WILL INCREASE INTO THE 20 TO 30 KNOT RANGE DURING THIS TIME PERIOD WITH GUSTS AS HIGH AS 35 KNOTS SATURDAY NIGHT AND SUNDAY MORNING. WAVES WILL BUILD INTO THE 2 TO 5 FOOT RANGE MAKING FOR ROUGH BOATING CONDITIONS FOR A GOOD PART OF THE WEEKEND. AS A RESULT...A LAKE WIND ADVISORY IS IN EFFECT FROM MIDNIGHT TONIGHT RIGHT THROUGH SUNDAY MORNING. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...JMG SHORT TERM...EVENSON LONG TERM...BANACOS AVIATION...BANACOS MARINE...EVENSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
137 AM EDT SAT SEP 20 2014 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BRING DRY WEATHER TO THE NORTH COUNTRY TONIGHT...BUT TEMPERATURES WILL NOT BE AS COLD AS LAST NIGHT. LOOKING FOR WARMER...WINDIER...AND WETTER CONDITIONS THIS WEEKEND. HIGHS SATURDAY AND SUNDAY WILL BE IN THE 60S TO LOWER 70S. WINDS WILL BE INCREASING DURING THE DAY ON SATURDAY WITH GUSTS IN THE 30 TO 40 MPH RANGE. EVENTUALLY RAIN WILL MOVE IN LATE SATURDAY NIGHT AND ESPECIALLY THROUGHOUT THE DAY ON SUNDAY WITH WIDESPREAD RAIN EXPECTED SUNDAY AFTERNOON AND NIGHT. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1027 PM EDT FRIDAY...MINOR ADJUSTMENTS TO HOURLY T/TD DATA AS OF THE 10 O`CLOCK HOUR TO ACCOUNT FOR CURRENT OBSERVATIONAL TRENDS. SOUTHERLY RETURN FLOW HAS COMMENCED WITH SOME AREAS...PARTICULARLY THE CHAMPLAIN AND ST LAWRENCE VALLEYS HAVING LIKELY ALREADY EXPERIENCED THEIR OVERNIGHT LOWS AS READINGS SLOWLY CLIMB OVERNIGHT. OTHER AREAS HAVE DECOUPLED SO MORE OF A TYPICAL DIURNAL TREND EXPECTED...NAMELY ERN VT AND PORTIONS OF THE ADIRONDACKS. CASE IN POINT TRUSTY SARANAC LAKE ALREADY AT THE FREEZING MARK. HAVE A GREAT NIGHT. PRIOR DISCUSSION FOLLOWS... PRIOR DISCUSSION... FORECAST REMAINS IN GOOD SHAPE AS WE PROGRESS INTO THE EVENING HOURS. CLEAR SKIES WILL GRADUALLY GIVE WAY TO SOME HIGH CLOUDS (ESPECIALLY NORTH) OVERNIGHT AS SURFACE HIGH PRESSURE SLIDES OFFSHORE AS SOUTH/SOUTHWESTERLY RETURN FLOW BEGINS IN EARNEST ALOFT...NOT AS MUCH AT THE SURFACE. NONETHELESS READINGS WILL BE MILDER TONIGHT THAN LAST NIGHT GIVEN WARM THERMAL RESPONSE THROUGH THE 925-850 MB LEVEL. STUCK CLOSE TO LATEST RAP 500 MB RH PROGS WHICH APPEARS TO BE HANDLING THICKER MID LEVEL CLOUDS OFF TO OUR NORTH...AND ITS SUBSEQUENT PROGRESSION RATHER WELL THIS EVENING. LOWS REMAIN ON TRACK...RANGING FROM THE MID TO UPPER 30S IN ERN VT...UPPER 30S TO LOWER 40S DACKS...AND SOLIDLY IN THE 40S FOR THE CHAMPLAIN AND ST LAWRENCE VALLEYS. && .SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 336 PM EDT FRIDAY...PRESSURE GRADIENT WILL CONTINUE TO STRENGTHEN FROM THE SOUTH AND SOUTHWEST DURING THE DAY ON SATURDAY. WHILE THIS WILL PROMOTE LOW LEVEL WARM AIR ADVECTION...BREEZY TO WINDY CONDITIONS WILL DEVELOP. SO WHILE HIGHS WILL BE IN THE MID 60S TO THE LOWER 70S...THE WINDS WILL NOT ALLOW FOR IT TO FEEL THAT WARM WITH GUSTS IN THE 25 TO 35 MPH RANGE AND EVEN SOME 40 MPH GUSTS IN THE SAINT LAWRENCE VALLEY. DRY WEATHER IS EXPECTED DURING THE DAY ON SATURDAY...BUT THAT WILL CHANGE AS AN UPPER LEVEL TROUGH OF LOW PRESSURE DEVELOPS OVER THE UPPER MIDWEST. THIS FEATURE WILL BEGIN TO SHARPEN UP SATURDAY NIGHT WHICH WILL ULTIMATELY SLOW THE ONSET OF THE PRECIPITATION DOWN. CAN SEE A CHANCE OF SHOWERS LATE SATURDAY NIGHT OVER NORTHERN NEW YORK...BUT THE STEADIER AND MORE WIDESPREAD SHOWERS WILL NOT MOVE INTO THE ENTIRE AREA UNTIL LATER SUNDAY MORNING THROUGH SUNDAY NIGHT. THE CLOUDS AND GUSTY WINDS SATURDAY NIGHT WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL...SO IT WILL NOT TAKE MUCH ON SUNDAY FOR HIGHS TO GET RIGHT BACK INTO THE MID 60S TO LOWER 70S. THE UPPER TROUGH WILL BE SLOW TO MOVE EAST OF THE AREA SUNDAY NIGHT...SO SHOWERS SHOULD BE FAIRLY WIDESPREAD SUNDAY EVENING BEFORE GRADUALLY TAPERING OFF AFTER MIDNIGHT. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 336 PM EDT FRIDAY...NORTHWEST FLOW ALOFT WILL EXIST OVER THE AREA MONDAY AND TUESDAY. THERE MAY BE SOME LINGERING SHOWERS MONDAY MORNING...ESPECIALLY OVER VERMONT...BUT DRIER WEATHER IS EXPECTED TO DEVELOP MONDAY AFTERNOON THROUGH TUESDAY. THE NORTHWEST FLOW ALOFT WILL RESULT IN BELOW NORMAL HIGH TEMPERATURES. LARGE UPPER LEVEL RIDGE BUILDS INTO THE REGION WEDNESDAY THROUGH FRIDAY. THIS WILL RESULT IN A WARMING TREND WITH HIGH TEMPERATURES AT OR ABOVE SEASONAL NORMALS THURSDAY AND FRIDAY. DRY WEATHER WILL ALSO EXIST WEDNESDAY THROUGH FRIDAY. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... THROUGH 12Z SUNDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD...THOUGH THERE WILL BE AN INCREASE IN MID-UPPER LEVEL CLOUDS THROUGH THE DAYLIGHT HOURS AREAWIDE. ALSO WATCHING SOME DEVELOPING STRATUS ACROSS E-CENTRAL NY...WHICH WILL IMPACT RUT/MPV AT TIMES THIS MORNING WITH SCT-BKN040-050. NO PRECIPITATION IS EXPECTED THROUGH THE PERIOD. WINDS WILL BE INCREASING FROM THE SOUTH TO SOUTHWEST...ESPECIALLY DURING THE DAYLIGHT HOURS WITH INCREASING PRESSURE GRADIENT. AT BTV...WINDS ALREADY 10KTS AND WILL INCREASE TO 15G25KT AFTER 13-14Z. WILL ALSO BE DEALING WITH LOW-LEVEL WIND SHEAR AT PBG/MSS/SLK UNTIL LOW-LEVELS MIX OUT AFTER 12Z THIS MORNING. INCLUDED LLWS IN THE TAFS AT ABOVE MENTIONED TAF SITES THIS MORNING...WITH STRONGEST SHEAR BETWEEN 1.5-2 KFT AGL. OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...FRONTAL SYSTEM MOVING IN FROM THE WEST WILL BRING POTENTIAL FOR WIDELY SCATTERED RAIN SHOWERS DURING THE DAY SUNDAY...WITH PERIODS OF MVFR CEILINGS AND VSBYS. UPPER TROUGH REMAINS IN PLACE WITH POTENTIAL FOR SCATTERED SHOWERS SUNDAY NIGHT INTO MONDAY. MAY SEE SOME PERIODS OF CONTINUING MVFR CEILINGS DURING SUN NIGHT AND MONDAY. GENERALLY TRENDING VFR MONDAY NIGHT ONWARD WITH DEVELOPING STRONG SURFACE AND UPPER RIDGE BY MID-WEEK ACROSS THE GREAT LAKES AND NEW ENGLAND. && .MARINE... STRONG SOUTH TO SOUTHWEST WINDS WILL DEVELOP AFTER MIDNIGHT TONIGHT AND CONTINUE RIGHT INTO SUNDAY MORNING. SPEEDS WILL INCREASE INTO THE 20 TO 30 KNOT RANGE DURING THIS TIME PERIOD WITH GUSTS AS HIGH AS 35 KNOTS SATURDAY NIGHT AND SUNDAY MORNING. WAVES WILL BUILD INTO THE 2 TO 5 FOOT RANGE MAKING FOR ROUGH BOATING CONDITIONS FOR A GOOD PART OF THE WEEKEND. AS A RESULT...A LAKE WIND ADVISORY IS IN EFFECT FROM MIDNIGHT TONIGHT RIGHT THROUGH SUNDAY MORNING. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...JMG SHORT TERM...EVENSON LONG TERM...EVENSON AVIATION...BANACOS MARINE...EVENSON
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
630 PM EDT SAT SEP 20 2014 .SYNOPSIS... HIGH PRESSURE BREAKS DOWN ACROSS THE AREA EARLY TONIGHT AS A LARGE AREA OF LOW PRESSURE LIFTS NORTHEAST ALONG THE SOUTHERN US COAST TONIGHT THROUGH THE DAY ON SUNDAY. A COLD FRONT WILL MOVE THROUGH MONDAY. HIGH PRESSURE BEHIND THE FRONT WILL BUILD IN BEHIND THE FRONT TO THE NORTH OF THE AREA AND REMAIN THERE THROUGH LATE WEEK. && .NEAR TERM /REST OF THE NIGHT/... AS OF 630 PM SAT...LARGE AREA OF MODERATE TO OCNL HEAVY RAIN MOVING ONSHORE ACROSS OUTER BANKS/CARTERET COUNTY EARLY THIS EVENING. THIS IN ASSOCIATION WITH ENHANCED MID LEVEL OMEGA/FGEN OBSERVED IN RUC X-SECTIONS. HAVE INC POPS A BIT MORE TO ACCOUNT FOR NEAR TERM TRENDS AND EXPECTED INC IN VORT ADVECTION ALONG THE COAST THROUGH THE NIGHT. HAVE CORRESPONDINGLY INC QPF AMOUNTS THROUGH THE NIGHT AS DUAL POL P-RATES JIVING WITH OBSERVED RATES OF 1 TO OCNL 2 INCHES PER HOUR. BOUTS OF HEAVY RAIN WILL CONTINUE TO ROTATE ONSHORE THROUGH THE NIGHT AS LOW AXIS MOVES NORTHWARD JUST OFFSHORE CONTINUING STRONG THERMAL GRADIENT AND ACTS TO GENERATE STRONG OMEGA/FGEN. LOCALIZED FLOODING WITH THE HEAVIER SHOWERS CERTAINLY WILL BE A THREAT...AND HAVE INCLUDED HEAVY RAIN WORDING IN FCST GRIDS. PREVIOUS DISCUSSION...EXPECT THE BRIEF LULL IN SHOWER ACTIVITY THIS AFTERNOON TO NOT LAST LONG AS A LARGE AREA OF SHOWERS ASSOCIATED WITH THE LOW LIFTING NORTHEAST OFF THE SOUTHEASTERN US COAST MAKES ITS WAY TOWARDS THE COAST. CARRIED CATEGORICAL 80 POPS ALONG THE IMMEDIATE COAST FOR TONIGHT FROM THE VICINITY OF LOOKOUT THROUGH CAPE HATTERAS...ASSOCIATED WITH THE LOW AND AN UPPER TROF ACROSS THE SOUTHEAST. PRECIPITABLE WATER VALUES WILL BE ABNORMALLY HIGH ACROSS THE COAST TONIGHT PERHAPS A BIT ABOVE 2.25 INCHES AS A PLUME OF TROPICAL MOISTURE STREAMS UP THE COAST. THIS IS ABOUT TWO STANDARD DEVIATIONS ABOVE NORMAL. EXPECT TO SEE PERIODS OF VERY HEAVY RAINFALL AS SHOWERS MOVE ACROSS THE COAST TONIGHT. THIS COULD RESULT IN SOME MINOR FLOODING OF LOW LYING AND POOR DRAINAGE AREAS. THE GOOD NEWS IS THE HEAVIEST PRECIPITATION SHOULD REMAIN ALONG COASTAL AREAS...NOT PENETRATING TOO FAR INLAND. WILL SEE EXTENSIVE CLOUD COVER ACROSS THE AREA OVERNIGHT. FOLLOWED A BLEND OF MOS GUIDANCE WITH LOWS IN THE MID 60S INLAND TO LOWER 70S ALONG THE COAST. && .SHORT TERM /SUNDAY/... AS OF 330 PM SAT...THE COASTAL LOW AND ASSOCIATED MOISTURE WILL BEGIN TO DEPART THE AREA ON SUNDAY WITH DECREASING POPS FROM WEST TO EAST THROUGH THE DAY. EXPECT RAIN TO BE OFF THE OUTER BANKS BY AROUND MID AFTERNOON. CLOUDS WILL DECREASE FROM WEST TO EAST AS WELL WITH CLEARING BY THE AFTERNOON MOST PLACES. AGAIN FOLLOWED A BLEND OF MOS GUIDANCE WITH HIGHS IN THE LOW TO MID 80S. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... AS OF 255 PM SATURDAY...COLD FRONT WILL APPROACH THE AREA SUNDAY NIGHT AND SHOULD PUSH OFFSHORE SOMETIME DURING THE LATE MORNING HOURS ON MONDAY. GFS/NAM12/ECMWF CONTINUE TO INDICATE A BROKEN LINE OF SHOWERS AND PERHAPS A TSTM OR TWO WILL ACCOMPANY THE FRONT. STRONG HIGH PRESSURE WILL THEN EXPAND SOUTH FROM THE GREAT LAKES MONDAY NIGHT AND TUESDAY WITH VERY COMFORTABLE FALL LIKE TEMPERATURES FOR MOST OF THE AREA...WITH MID/UPPER 50S INLAND AND LOW/MID 60S COAST. GFS AND ECMWF DIVERGE FOR THE MID WEEK PERIOD WITH THE ECMWF CUTTING OFF THE SOUTHERN PORTION OF DEEP MID-LEVEL TROUGH OVER SOUTH CAROLINA TUESDAY AFTERNOON THROUGH WEDNESDAY WHILE THE GFS KEEPS A BROAD TROUGH OVER THE EASTERN US. AS A RESULT...THE ECMWF IS MUCH WETTER SHOWING PRECIPITATION EVEN ON TUESDAY WHILE THE GFS IS DRY TUESDAY AND WEDNESDAY. HAVE TRENDED THIS PORTION OF THE FORECAST TOWARD THE GFS WHICH HAS BEEN MORE CONSISTENT...BUT CANNOT IGNORE THE ECMWF SOLUTION COMPLETELY WHICH IS CLOSE TO WPC GUIDANCE...AND THUS HAVE A SMALL POP IN THE FORECAST...MAINLY EASTERN SECTIONS WEDNESDAY. WITH INVERTED SURFACE TROUGH MOVING TOWARD THE COAST ON THURSDAY...BETTER AGREEMENT WITH AT LEAST A SMALL CHANCE OF RAIN ACROSS THE REGION. WITH A VERY WEAK UPPER LEVEL FLOW AND CONTINUED FEED OF MOISTURE FROM THE ATLANTIC ON A SOUTHEAST FLOW...WILL LIKEWISE HAVE SMALL POPS OVER MAINLY THE EASTERN TWO-THIRDS OF THE CWA FRIDAY AND SATURDAY. TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS MID/UPPER 70S WITH A FEW LOWER 80S AND NIGHTTIME LOWS MAINLY IN THE UPPER 50S TO MID 60S THROUGH THE PERIOD. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... SHORT TERM /THROUGH SUNDAY/... AS OF 630 PM SAT...LARGE AREA OF RAIN SHOWERS MOVING ONSHORE OF THE NC COAST THIS EVENING. BULK OF WIDESPREAD HEAVY RAIN WILL REMAIN EAST OF THE TERMINALS...THOUGH WILL SEE OCNL BOUTS OF HEAVIER SHOWERS POSSIBLY AFFECT ESP THE KEWN AND KOAJ TAF SITES WITH MORE SCT ACTIVITY INLAND. CIGS WILL DROP TO MVFR FROM EAST TO WEST ACROSS EASTERN NC THIS EVENING. COULD EVEN SEE SOME IFR CONDITIONS WITH BEST CONFIDENCE OF A FEW HOURS OF IFR CIGS AT KEWN WHERE DEEPER LOW LEVEL MOISTURE WILL EXIST LATE TONIGHT. CONDITIONS WILL IMPROVE RAPIDLY ON SUNDAY AS AREA OF LOW PRES MOVES AWAY FROM THE COAST AND WINDS TURN WNW BRINGING IN MUCH DRIER AIR. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 3 PM SATURDAY...COULD SEE SOME TEMPORARY REDUCTIONS TO MVFR WITH A FEW SHOWERS ALONG THE COLD FRONT DURING THE MORNING HOURS ON MONDAY. WITH DRY HIGH PRESSURE BUILDING IN FROM THE NORTH...TUESDAY SHOULD BE VFR. ANTICIPATE MOSTLY VFR ON WEDNESDAY AS WELL...AS MODEL UNCERTAINTY EXISTS BETWEEN GFS/ECMWF ON EXTENT OF MOISTURE/PRECIPITATION INTO THE AREA. A BETTER AGREEMENT BETWEEN MODELS EXISTS THURSDAY WITH SCATTERED SHOWERS AND OCCASIONAL MVFR CEILINGS AND VSBYS. A MORE MOIST BOUNDARY LAYER BY WEDNESDAY AND THURSDAY WILL ALSO LEAD TO PATCHY FOG DURING THE LATE NIGHT AND EARLY MORNING HOURS WITH MVFR AND PSBL IFR CONDITIONS. && .MARINE... SHORT TERM /THROUGH TONIGHT/ AS OF 330 PM SAT...CONTINUED ON STRONG SIDE OF MODEL GUIDANCE FOR THE REMAINDER OF THE AFTERNOON AND TONIGHT BLENDING THE HIGH RES NAM/ARW INTO THE FORECAST FOR WINDS. SCA CONDITIONS WILL PERSIST ALL COASTAL WATERS THROUGH SUNDAY. SEAS REMAIN HIGH AND HAVE JUMPED TO 7 TO 8 FEET ACROSS PORTIONS OF THE NORTHERN AND CENTRAL WATERS WITH 6 FOOT SEAS TO THE SOUTH. USED NWPS GUIDANCE AND HAD TO INCREASE SLIGHTLY FOR THE EARLY PERIOD TONIGHT TO ACCOUNT FOR HIGHER SEAS IN THE COASTAL WATERS. WILL SEE TREACHEROUS BOATING CONDITIONS ACROSS THE COASTAL WATERS THROUGH THE DAY ON SUNDAY AS SEAS BUILD TO 8 TO 9 FEET ACROSS THE WATERS AS THE AREA OF LOW PRESSURE LIFTS ACROSS THE AREA. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 305 PM SATURDAY...AN UNSETTLED EXTENDED PERIOD EXPECTED ON THE COASTAL WATERS AND SOUNDS. BASED ON LATEST OUTPUT FROM LOCAL SWAN/NWPS MODEL...HAVE OPTED TO EXTEND THE SMALL CRAFT ADVISORY NORTH OF OCRACOKE INTO MONDAY MORNING FOR SEAS. AFTER A BRIEF LULL MONDAY/MONDAY NIGHT...WINDS/SEAS BUILD AGAIN TUESDAY INTO THURSDAY WITH LONG FETCH NORTHEAST FLOW AROUND STRONG 1035 MB HIGH OVER SOUTHERN NEW ENGLAND AND WEAK INVERTED TROUGH OFFSHORE. LONGER RANGE WAVEWATCH GUIDANCE INDICATES THAT ELEVATED SEAS AND SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY TO EXTEND INTO NEXT WEEKEND. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR AMZ150-152-154. SMALL CRAFT ADVISORY UNTIL 9 PM EDT SUNDAY FOR AMZ156-158. && $$ SYNOPSIS...RSB NEAR TERM...RSB/TL SHORT TERM...RSB LONG TERM...CTC AVIATION...RSB/CTC/TL MARINE...RSB/CTC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
747 AM EDT SAT SEP 20 2014 .SYNOPSIS... HIGH PRESSURE WILL RIDGE INTO THE REGION FROM THE NORTH TODAY. LOW PRESSURE WILL MOVE NORTHEAST SUNDAY JUST OFF THE COAST. A COLD FRONT WILL MOVE THROUGH MONDAY. HIGH PRESSURE BEHIND THE FRONT WILL PASS BY TO THE NORTH TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 730 AM SAT...MINOR UPDATE TO FORECAST TO CAPTURE T/TD AND PRECIP TRENDS THIS MORNING. 1030 MB HIGH PRES CENTERED OFF THE NEW ENGLAND COAST CONTINUES TO RIDGE SWWD INTO THE REGION WHILE AN INVERTED TROUGH OVER THE OFFSHORE WATERS IS ADVANCING TOWARD THE COAST AND A 1012 MB LOW PRES IS DEVELOPING OFF THE EAST COAST OF FL. MEANWHILE A WEAK UPPER LOW RESIDES OVER THE SOUTHEAST STATES WITH A NORTHERN STREAM SHORTWAVE TROUGH MOVING INTO THE GREAT LAKES. THE UPPER TROUGH WILL CONTINUE TO DIG INTO THE MIDWEST AND GREAT LAKES THROUGH THE PERIOD AND WILL BEGIN TO ABSORB THE UPPER LOW OVER THE SOUTHEAST WHICH IN RESPONSE WILL LIFT THE SFC LOW NORTH JUST OFF THE SOUTHEAST COAST. EXPECT THE COASTAL TROUGH TO MOVE INTO EASTERN SECTIONS TODAY THEN GRADUALLY DISSIPATE WHILE THE SFC LOW LIFTS NORTH TO OFF THE SC COAST BY LATE IN THE PERIOD. A FEW SHOWERS SHOWING UP ON RADAR ACROSS THE COASTAL WATERS ASSOC WITH THE COASTAL TROUGH AND EXPECT THESE TO CONTINUE TO ADVANCE TOWARD THE COAST THROUGH THE MORNING. THE BEST CHANCE OF SHOWERS...AND POSSIBLY AN ISOLATED THUNDERSTORM...WILL OCCUR ACROSS EASTERN SECTIONS TODAY AS THE SHOWERS WILL TEND TO DISSIPATE AS THEY MOVE INTO A DRIER AIRMASS RIDGING IN FROM THE NORTH. IN ADDITION...COULD SEE SOME SHOWERS ASSOC WITH THE LOW TO THE SOUTH LIFTING TOWARD THE REGION BY LATE AFTERNOON...MAINLY AFFECTING THE CRYSTAL COAST. MOSTLY CLOUDY SKIES EXPECTED EASTERN SECTIONS WITH VARIABLY CLOUDY SKIES TO THE WEST. HIGHS TODAY WILL REACH A COUPLE DEGREES EITHER SIDE OF 80. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... AS OF 230 AM SAT...THE SFC LOW WILL CONTINUE TO LIFT NORTH ALONG THE COAST TONIGHT AND MODELS IN FAIRLY CLOSE AGREEMENT WITH THE LOW POSITIONED SE OF CAPE LOOKOUT BY 12Z SUN. SLIGHTLY IMPROVING UPPER LEVEL SUPPORT WITH A STRENGTHENING JET STREAK JUST TO THE NORTH COUPLED WITH LOW LEVEL CONVERGENCE NEAR THE COASTAL TROUGH AND SFC LOW WILL BRING A DESCENT CHANCE OF SHOWERS ACROSS EASTERN SECTIONS TONIGHT. THERE WILL LIKELY BE A SHARP GRADIENT OF PCPN ACROSS THE REGION WITH BEST CHANCES EAST OF HIGHWAY 17 WHERE FORCING WILL BE MORE FAVORABLE AND MOISTURE WILL BE GREATER. MODELS NOT IN BEST AGREEMENT WITH PRECIP AMOUNTS BUT COULD SEE AS MUCH AS 1/2 TO 1" ALONG THE IMMEDIATE COAST FROM AROUND CAPE LOOKOUT TO OREGON INLET BUT THEN TAPER OFF RATHER QUICKLY WEST OF A LINE FROM JACKSONVILLE TO NEW BERN TO COLUMBIA. LOWS EXPECTED IN THE MID 60S WELL INLAND TO LOWER 70S ALONG THE COAST. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 232 AM SAT...ACTIVE PATTERN THROUGH THE FIRST PART OF THE LONG TERM PERIOD. MODELS AGREE THAT CUT OFF UPPER LOW OVER THE FL/GA AREA WILL MOVE UP THE COAST AS IT DEEPENS. ACCOMPANYING SURFACE LOW WILL SKIRT THE COAST...AND IS EXPECTED TO BE ALONG THE NORTH CAROLINA COAST SUNDAY MORNING. UPPER LEVEL ENERGY WILL BE CENTERED OFFSHORE...THIS WILL HELP KEEP HIGH CHANCES OF PRECIPITATION CONFINED MAINLY TO COASTAL SECTIONS. INSTABILITY LIMITED BUT CANT COMPLETELY RULE OUT THUNDERSTORMS. PWS JUST BELOW 2 INCHES SUNDAY MORNING...BUT QUICKLY DROPS OFF AS SYSTEM MOVES AWAY. AS SYSTEM LIFTS NORTH OF THE AREA DURING THE DAY SUNDAY...UPPER FLOW WILL BRIEFLY BECOME ZONAL AHEAD OF NEXT APPROACHING TROUGH. THIS NEXT SYSTEM WILL PUSH A FRONT AHEAD OF IT THROUGH EASTERN NORTH CAROLINA EARLY MONDAY. NOT AN AWFUL LOT OF MOISTURE EVIDENT IN THE MODELS WITH THIS BOUNDARY...AND UPPER LEVEL ENERGY LAGS BEHIND IT...SO WILL KEEP PRECIPITATION CHANCES LOW. HIGH PRESSURE WILL QUICKLY BUILD IN BEHIND THE FRONT MONDAY NIGHT. HOWEVER MODELS DIFFER A BIT AT THIS TIME PERIOD IN THE UPPER LEVEL PATTERN WITH ECMWF DIGGING A DEEPER UPPER LEVEL TROUGH DOWN THE EAST COAST AND THE GFSENS BEING NOT AS DEEP. THIS DOESNT APPEAR TO AFFECT THE SURFACE PATTERN AS MODELS AGREE ON HIGH PRESSURE NORTH OF THE AREA THROUGH THE REMAINDER OF THE WEEK. MODELS DO HINT AT A WEAK INVERTED TROUGH ALONG THE COAST LATE IN THE WEEK. CURRENT GRIDS HAVE LOW POPS AND WILL CONTINUE THAT TREND. && .AVIATION /11Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 730 AM SAT...PRED VFR EXPECTED THROUGH THE TAF PERIOD. A COASTAL TROUGH WILL MOVE INTO EASTERN NC TODAY WITH SFC LOW PRES LIFTING NORTH ALONG THE SE COAST AND EXPECT VARIABLY CLOUDY SKIES WITH GREATEST COVERAGE EASTERN SECTIONS. COULD SEE ISOLATED SHOWERS TODAY AS THE COASTAL TROUGH MOVES INLAND BUT BETTER CHANCE OF SHOWERS WILL OCCUR TONIGHT AS THE LOW LIFTS NE JUST OFF THE COAST. COASTAL SITES WILL HAVE THE BETTER CHANCE OF RECEIVING PRECIP WHILE PGV AND ISO COULD VERY WELL REMAIN DRY. IF HEAVIER PRECIP DEVELOPS COULD SEE BRIEF REDUCTIONS IN CIGS/VSBYS TO MVFR OR POSSIBLY IFR. NE FLOW WILL CONTINUE TODAY WITH GUSTS TO AROUND 15 KT POSSIBLE THIS AFTERNOON. GUIDANCE SUGGESTING FOG/STRATUS POSSIBLE TONIGHT BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN TAFS ATTM. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 240 AM SAT...LOW PRESSURE WILL MOVE UP THE COAST THIS WEEKEND...AND BE OFF THE NORTH CAROLINA COAST BY SUNDAY MORNING. WILL HAVE SOME MVFR CIGS/VIS SUNDAY IN ASSOCIATED SHOWERS AND LOW CLOUDS. THIS SYSTEM WILL MOVE AWAY FROM THE AREA LATE SUNDAY AS ANOTHER SYSTEM APPROACHES FROM THE WEST. NOT TOO MUCH MOISTURE ASSOCIATED WITH THIS FRONTAL BOUNDARY AND UPPER LEVEL ENERGY STAYS WEST AS IT MOVES THROUGH EASTERN NORTH CAROLINA MONDAY MORNING. MAY HAVE ISOLATED MVFR CIGS/VIS IN ANY SHOWERS THAT DEVELOP. HIGH PRESSURE BUILDS IN BEHIND THE FRONT WITH MAINLY VFR CONDITIONS EXPECTED MONDAY NIGHT THROUGH WEDNESDAY...HOWEVER MAY HAVE SUB VFR CONDITIONS IN THE PREDAWN HOURS WITH NORTHEASTERLY FLOW. && .MARINE... SHORT TERM /THROUGH TONIGHT/ AS OF 530 AM SAT...EXTENDED THE SCA FOR THE PAMLICO SOUND AND WATERS SOUTH OF OCRACOKE INLET UNTIL 15Z AS OBS CONTINUE TO SHOW FREQUENT GUSTS TO 25 KT AND SEAS UP TO 6 FT ACROSS THE COASTAL WATERS. MOST MODELS STILL TOO QUICK TO BRING DOWN WINDS/SEAS EARLY THIS MORNING. BLENDED HEAVILY WITH THE RUC FOR WINDS WHICH IS MUCH STRONGER...AND PERHAPS TOO STRONG...THAN ANY OTHER MODEL BETWEEN 12-18Z...BUT SEEMS TO CAPTURE THE CURRENT CONDITIONS BETTER. IF THE RUC DOES VERIFY LATER THIS MORNING AN EXPANSION OF TIME AND AREA FOR THE SCA WILL BE NECESSARY. PREVIOUS DISCUSSION...STRONG SFC HIGH PRES CONTINUES TO RIDGE INTO THE REGION EARLY THIS MORNING BRINGING NE FLOW AROUND 10-20 KT WITH MANY AREAS SOUTH OF OREGON INLET SEEING FREQUENT GUSTS TO AROUND 25 KT. EXPECT WINDS TO GRADUALLY DIMINISH TO AROUND 10-15 KT BY THIS AFTERNOON AS A COASTAL TROUGH MOVES INTO THE REGION ALLOWING GRADIENTS TO WEAKEN SOME. GRADIENTS EXPECTED TO TIGHTEN AGAIN TONIGHT...MAINLY AFTER MIDNIGHT...AS THE SFC LOW LIFTS TO JUST OFF CAPE FEAR BY LATE TONIGHT BRINGING WINDS TO 10-20 KT AND POSSIBLY GUSTS TO AROUND 25 KT. SEAS REMAIN TRICKY AS MODELS A FOOT OR TWO UNDERDONE THIS PAST EVENING AND HAVE BEEN TOO QUICK TO DISSIPATE. SEAS CURRENTLY 4-6 FT AND ARE EXPECTED TO SUBSIDE TO BELOW SCA CRITERIA SOUTH OF OREGON INLET THIS MORNING AS GRADIENTS WEAKEN SOME...HOWEVER THE PROLONGED NE FETCH OF WINDS ARE EXPECTED TO KEEP SEAS ELEVATED UP TO 5-7 FT NORTH OF OREGON INLET THROUGH THE SHORT TERM. MODELS ALSO INDICATING SEAS REBUILD UP TO 6 FT SOUTH OF OCRACOKE INLET AFTER MIDNIGHT TONIGHT WITH GRADIENTS TIGHTENING NEAR THE LOW LIFTING TOWARD THE REGION. LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 252 AM SAT...SURFACE WIND WILL BE VARIABLE SUNDAY MORNING AS LOW PRESSURE MOVES UP THE COAST AND ACROSS THE NORTH CAROLINA COASTAL WATERS. AM EXPECTING THE LOW PRESSURE TO REMAIN JUST EAST OF THE WATERS WITH NORTH NORTH WESTERLY FLOW. SPEEDS WILL BE 20 TO 25 KNOTS . IF LOW TRACKS FURTHER WEST...SPEEDS WILL BE LIGHT AND DIRECTION WILL BE DEPENDENT ON WHERE THE LOW TRACKS. SEA HEIGHTS WILL REACH SMALL CRAFT ADVISORY CRITERIA OVER MOST OF THE WATERS WITH UP TO 8 FEET EXPECTED IN THE OUTER WATERS. AS THE LOW MOVES AWAY FROM THE AREA LATE SUNDAY...WIND SPEED AND SEAS WILL DECREASE BELOW SMALL CRAFT ADVISORY CRITERIA. DIRECTION WILL TURN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF NEXT APPROACHING SYSTEM. THIS FRONT IS EXPECTED TO PASS THROUGH THE WATERS MONDAY AFTERNOON WITH WIND BECOMING NORTH AND NORTHEASTERLY BEHIND IT AS HIGH PRESSURE BUILDS IN. GRADIENT BETWEEN THE DEPARTING LOW PRESSURE AND BUILDING HIGH PRESSURE WILL INCREASE WINDS TO 15 TO 20 KNOTS MONDAY NIGHT THROUGH WEDNESDAY. MODELS HINTING AS A TROUGH DEVELOPING ALONG THE COAST LATE WEDNESDAY...WHICH WILL HELP INCREASE WIND SPEEDS WEDNESDAY NIGHT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ135- 156-158. SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR AMZ150-152-154. && $$ SYNOPSIS...SK NEAR TERM...SK SHORT TERM...SK LONG TERM...CGG AVIATION...CGG/SK MARINE...CGG/SK
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
547 AM EDT SAT SEP 20 2014 .SYNOPSIS... HIGH PRESSURE WILL RIDGE INTO THE REGION FROM THE NORTH TODAY. LOW PRESSURE WILL MOVE NORTHEAST SUNDAY JUST OFF THE COAST. A COLD FRONT WILL MOVE THROUGH MONDAY. HIGH PRESSURE BEHIND THE FRONT WILL PASS BY TO THE NORTH TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 230 AM SAT...1030 MB HIGH PRES CENTERED OVER NEW ENGLAND CONTINUES TO RIDGE SWWD INTO THE REGION WHILE AN INVERTED TROUGH OVER THE OFFSHORE WATERS IS ADVANCING TOWARD THE COAST AND A 1014 MB LOW PRES IS DEVELOPING OFF THE EAST COAST OF FL. MEANWHILE A WEAK UPPER LOW RESIDES OVER THE SOUTHEAST STATES WITH A NORTHERN STREAM SHORTWAVE TROUGH MOVING INTO THE GREAT LAKES. THE UPPER TROUGH WILL CONTINUE TO DIG INTO THE MIDWEST AND GREAT LAKES THROUGH THE PERIOD AND WILL BEGIN TO ABSORB THE UPPER LOW OVER THE SOUTHEAST WHICH IN RESPONSE WILL LIFT THE SFC LOW NORTH JUST OFF THE SOUTHEAST COAST. EXPECT THE COASTAL TROUGH TO MOVE INTO EASTERN SECTIONS TODAY THEN GRADUALLY DISSIPATE WHILE THE SFC LOW LIFTS NORTH TO OFF THE SC COAST BY LATE IN THE PERIOD. A FEW SHOWERS SHOWING UP ON RADAR ACROSS THE COASTAL WATERS ASSOC WITH THE COASTAL TROUGH AND EXPECT THESE TO CONTINUE TO ADVANCE TOWARD THE COAST THROUGH THE MORNING. THE BEST CHANCE OF SHOWERS...AND POSSIBLY AN ISOLATED THUNDERSTORM...WILL OCCUR ACROSS EASTERN SECTIONS TODAY AS THE SHOWERS WILL TEND TO DISSIPATE AS THEY MOVE INTO A DRIER AIRMASS RIDGING IN FROM THE NORTH. IN ADDITION...COULD SEE SOME SHOWERS ASSOC WITH THE LOW TO THE SOUTH LIFTING TOWARD THE REGION BY LATE AFTERNOON...MAINLY AFFECTING THE CRYSTAL COAST. MOSTLY CLOUDY SKIES EXPECTED EASTERN SECTIONS WITH VARIABLY CLOUDY SKIES TO THE WEST. HIGHS TODAY WILL REACH A COUPLE DEGREES EITHER SIDE OF 80. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... AS OF 230 AM SAT...THE SFC LOW WILL CONTINUE TO LIFT NORTH ALONG THE COAST TONIGHT AND MODELS IN FAIRLY CLOSE AGREEMENT WITH THE LOW POSITIONED SE OF CAPE LOOKOUT BY 12Z SUN. SLIGHTLY IMPROVING UPPER LEVEL SUPPORT WITH A STRENGTHENING JET STREAK JUST TO THE NORTH COUPLED WITH LOW LEVEL CONVERGENCE NEAR THE COASTAL TROUGH AND SFC LOW WILL BRING A DESCENT CHANCE OF SHOWERS ACROSS EASTERN SECTIONS TONIGHT. THERE WILL LIKELY BE A SHARP GRADIENT OF PCPN ACROSS THE REGION WITH BEST CHANCES EAST OF HIGHWAY 17 WHERE FORCING WILL BE MORE FAVORABLE AND MOISTURE WILL BE GREATER. MODELS NOT IN BEST AGREEMENT WITH PRECIP AMOUNTS BUT COULD SEE AS MUCH AS 1/2 TO 1" ALONG THE IMMEDIATE COAST FROM AROUND CAPE LOOKOUT TO OREGON INLET BUT THEN TAPER OFF RATHER QUICKLY WEST OF A LINE FROM JACKSONVILLE TO NEW BERN TO COLUMBIA. LOWS EXPECTED IN THE MID 60S WELL INLAND TO LOWER 70S ALONG THE COAST. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 232 AM SAT...ACTIVE PATTERN THROUGH THE FIRST PART OF THE LONG TERM PERIOD. MODELS AGREE THAT CUT OFF UPPER LOW OVER THE FL/GA AREA WILL MOVE UP THE COAST AS IT DEEPENS. ACCOMPANYING SURFACE LOW WILL SKIRT THE COAST...AND IS EXPECTED TO BE ALONG THE NORTH CAROLINA COAST SUNDAY MORNING. UPPER LEVEL ENERGY WILL BE CENTERED OFFSHORE...THIS WILL HELP KEEP HIGH CHANCES OF PRECIPITATION CONFINED MAINLY TO COASTAL SECTIONS. INSTABILITY LIMITED BUT CANT COMPLETELY RULE OUT THUNDERSTORMS. PWS JUST BELOW 2 INCHES SUNDAY MORNING...BUT QUICKLY DROPS OFF AS SYSTEM MOVES AWAY. AS SYSTEM LIFTS NORTH OF THE AREA DURING THE DAY SUNDAY...UPPER FLOW WILL BRIEFLY BECOME ZONAL AHEAD OF NEXT APPROACHING TROUGH. THIS NEXT SYSTEM WILL PUSH A FRONT AHEAD OF IT THROUGH EASTERN NORTH CAROLINA EARLY MONDAY. NOT AN AWFUL LOT OF MOISTURE EVIDENT IN THE MODELS WITH THIS BOUNDARY...AND UPPER LEVEL ENERGY LAGS BEHIND IT...SO WILL KEEP PRECIPITATION CHANCES LOW. HIGH PRESSURE WILL QUICKLY BUILD IN BEHIND THE FRONT MONDAY NIGHT. HOWEVER MODELS DIFFER A BIT AT THIS TIME PERIOD IN THE UPPER LEVEL PATTERN WITH ECMWF DIGGING A DEEPER UPPER LEVEL TROUGH DOWN THE EAST COAST AND THE GFSENS BEING NOT AS DEEP. THIS DOESNT APPEAR TO AFFECT THE SURFACE PATTERN AS MODELS AGREE ON HIGH PRESSURE NORTH OF THE AREA THROUGH THE REMAINDER OF THE WEEK. MODELS DO HINT AT A WEAK INVERTED TROUGH ALONG THE COAST LATE IN THE WEEK. CURRENT GRIDS HAVE LOW POPS AND WILL CONTINUE THAT TREND. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 230 AM SAT...PRED VFR EXPECTED THROUGH THE TAF PERIOD. CLOUDS AND LIGHT MIXING PREVENTING FOG DEVELOPMENT THIS MORNING BUT CANNOT RULE OUT BRIEF PERIODS OF MVFR VSBYS AT PGV WHERE SKIES HAVE REMAINED CLEAR...DEWPOINT DEPRESSION HAVE BEEN LOW AND DECOUPLING HAS OCCURRED AT TIMES. A COASTAL TROUGH WILL MOVE INTO EASTERN NC TODAY WITH SFC LOW PRES LIFTING NORTH ALONG THE SE COAST AND EXPECT VARIABLY CLOUDY SKIES WITH GREATEST COVERAGE EASTERN SECTIONS. COULD SEE AN ISOLATED SHOWER TODAY AS THE COASTAL TROUGH MOVES INLAND BUT BETTER CHANCE OF SHOWERS WILL OCCUR TONIGHT AS THE LOW LIFTS NE JUST OFF THE COAST. COASTAL SITES WILL HAVE THE BETTER CHANCE OF RECEIVING PRECIP WHILE PGV AND ISO COULD VERY WELL REMAIN DRY. IF HEAVIER PRECIP DEVELOPS COULD SEE BRIEF REDUCTIONS IN CIGS/VSBYS TO MVFR OR POSSIBLY IFR. NE FLOW WILL CONTINUE TODAY WITH GUSTS TO AROUND 15 KT POSSIBLE THIS AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 240 AM SAT...LOW PRESSURE WILL MOVE UP THE COAST THIS WEEKEND...AND BE OFF THE NORTH CAROLINA COAST BY SUNDAY MORNING. WILL HAVE SOME MVFR CIGS/VIS SUNDAY IN ASSOCIATED SHOWERS AND LOW CLOUDS. THIS SYSTEM WILL MOVE AWAY FROM THE AREA LATE SUNDAY AS ANOTHER SYSTEM APPROACHES FROM THE WEST. NOT TOO MUCH MOISTURE ASSOCIATED WITH THIS FRONTAL BOUNDARY AND UPPER LEVEL ENERGY STAYS WEST AS IT MOVES THROUGH EASTERN NORTH CAROLINA MONDAY MORNING. MAY HAVE ISOLATED MVFR CIGS/VIS IN ANY SHOWERS THAT DEVELOP. HIGH PRESSURE BUILDS IN BEHIND THE FRONT WITH MAINLY VFR CONDITIONS EXPECTED MONDAY NIGHT THROUGH WEDNESDAY...HOWEVER MAY HAVE SUB VFR CONDITIONS IN THE PREDAWN HOURS WITH NORTHEASTERLY FLOW. && .MARINE... SHORT TERM /THROUGH TONIGHT/ AS OF 530 AM SAT...EXTENDED THE SCA FOR THE PAMLICO SOUND AND WATERS SOUTH OF OCRACOKE INLET UNTIL 15Z AS OBS CONTINUE TO SHOW FREQUENT GUSTS TO 25 KT AND SEAS UP TO 6 FT ACROSS THE COASTAL WATERS. MOST MODELS STILL TOO QUICK TO BRING DOWN WINDS/SEAS EARLY THIS MORNING. BLENDED HEAVILY WITH THE RUC FOR WINDS WHICH IS MUCH STRONGER...AND PERHAPS TOO STRONG...THAN ANY OTHER MODEL BETWEEN 12-18Z...BUT SEEMS TO CAPTURE THE CURRENT CONDITIONS BETTER. IF THE RUC DOES VERIFY LATER THIS MORNING AN EXPANSION OF TIME AND AREA FOR THE SCA WILL BE NECESSARY. PREVIOUS DISCUSSION...STRONG SFC HIGH PRES CONTINUES TO RIDGE INTO THE REGION EARLY THIS MORNING BRINGING NE FLOW AROUND 10-20 KT WITH MANY AREAS SOUTH OF OREGON INLET SEEING FREQUENT GUSTS TO AROUND 25 KT. EXPECT WINDS TO GRADUALLY DIMINISH TO AROUND 10-15 KT BY THIS AFTERNOON AS A COASTAL TROUGH MOVES INTO THE REGION ALLOWING GRADIENTS TO WEAKEN SOME. GRADIENTS EXPECTED TO TIGHTEN AGAIN TONIGHT...MAINLY AFTER MIDNIGHT...AS THE SFC LOW LIFTS TO JUST OFF CAPE FEAR BY LATE TONIGHT BRINGING WINDS TO 10-20 KT AND POSSIBLY GUSTS TO AROUND 25 KT. SEAS REMAIN TRICKY AS MODELS A FOOT OR TWO UNDERDONE THIS PAST EVENING AND HAVE BEEN TOO QUICK TO DISSIPATE. SEAS CURRENTLY 4-6 FT AND ARE EXPECTED TO SUBSIDE TO BELOW SCA CRITERIA SOUTH OF OREGON INLET THIS MORNING AS GRADIENTS WEAKEN SOME...HOWEVER THE PROLONGED NE FETCH OF WINDS ARE EXPECTED TO KEEP SEAS ELEVATED UP TO 5-7 FT NORTH OF OREGON INLET THROUGH THE SHORT TERM. MODELS ALSO INDICATING SEAS REBUILD UP TO 6 FT SOUTH OF OCRACOKE INLET AFTER MIDNIGHT TONIGHT WITH GRADIENTS TIGHTENING NEAR THE LOW LIFTING TOWARD THE REGION. LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 252 AM SAT...SURFACE WIND WILL BE VARIABLE SUNDAY MORNING AS LOW PRESSURE MOVES UP THE COAST AND ACROSS THE NORTH CAROLINA COASTAL WATERS. AM EXPECTING THE LOW PRESSURE TO REMAIN JUST EAST OF THE WATERS WITH NORTH NORTH WESTERLY FLOW. SPEEDS WILL BE 20 TO 25 KNOTS . IF LOW TRACKS FURTHER WEST...SPEEDS WILL BE LIGHT AND DIRECTION WILL BE DEPENDENT ON WHERE THE LOW TRACKS. SEA HEIGHTS WILL REACH SMALL CRAFT ADVISORY CRITERIA OVER MOST OF THE WATERS WITH UP TO 8 FEET EXPECTED IN THE OUTER WATERS. AS THE LOW MOVES AWAY FROM THE AREA LATE SUNDAY...WIND SPEED AND SEAS WILL DECREASE BELOW SMALL CRAFT ADVISORY CRITERIA. DIRECTION WILL TURN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF NEXT APPROACHING SYSTEM. THIS FRONT IS EXPECTED TO PASS THROUGH THE WATERS MONDAY AFTERNOON WITH WIND BECOMING NORTH AND NORTHEASTERLY BEHIND IT AS HIGH PRESSURE BUILDS IN. GRADIENT BETWEEN THE DEPARTING LOW PRESSURE AND BUILDING HIGH PRESSURE WILL INCREASE WINDS TO 15 TO 20 KNOTS MONDAY NIGHT THROUGH WEDNESDAY. MODELS HINTING AS A TROUGH DEVELOPING ALONG THE COAST LATE WEDNESDAY...WHICH WILL HELP INCREASE WIND SPEEDS WEDNESDAY NIGHT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ135- 156-158. SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR AMZ150. && $$ SYNOPSIS...SK NEAR TERM...SK SHORT TERM...SK LONG TERM...CGG AVIATION...CGG/SK MARINE...CGG/SK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
942 PM CDT SUN SEP 21 2014 .UPDATE... ISSUED AT 940 PM CDT SUN SEP 21 2014 WE WILL ADD SOME PATCHY FOG LATER TONIGHT IN THE EAST. CAN/T RULE OUT PATCHY FOG IN ANY AREA...BUT WITH WEAK RETURN FLOW ALONG AND WEST OF THE VALLEY LATE TONIGHT...AND THE HRRR VSBYS INDICATING BEST POTENTIAL IN THE EAST...WILL ONLY MENTION HERE FOR NOW. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 308 PM CDT SUN SEP 21 2014 TEMPERATURES WILL BE THE MAIN CHALLENGE. MODELS ARE IN GOOD AGREEMENT. SURFACE HIGH PRESSURE WILL PROPAGATE ACROSS THE REGION AS UPPER LEVEL RIDGING BUILDS. CLOUDS WILL GRADUALLY DISSIPATE FROM WEST TO EAST THIS EVENING. SATELLITE IMAGERY INDICATES THE CLOUDS EAST OF THE VALLEY ARE NOT AS CELLULAR...AND MAY NOT DISSIPATE AS QUICKLY. LIGHT WINDS AND CLEAR SKY WILL LEAD TO GOOD RADIATIONAL COOLING CONDITIONS...AND EXPECT MINIMUM TEMPS IN THE 40S. RETURN FLOW COMMENCES BY MONDAY AFTERNOON. MAX TEMPS WILL MAKE IT INTO THE 70S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 308 PM CDT SUN SEP 21 2014 TUESDAY-WEDNESDAY...THE UPPER CIRCULATION CURRENTLY ACROSS THE SOUTHWEST CONUS WILL PROPAGATE THROUGH THE REGION. THE ECMWF AND GFS HAVE COME INTO BETTER AGREEMENT REGARDING WHERE THIS FEATURE WILL TRACK. THIS FORECASTED TRACK WOULD BRING SHOWERS INTO THE SOUTHERN AND EASTERN FA (AND ADJUSTED POPS ACCORDINGLY). LIMITED POPS TO A MAXIMUM OF 30 PERCENT SINCE THIS FEATURE WILL BASICALLY BE PROPAGATING INTO AN UPPER RIDGE/DRY AIRMASS. WEDNESDAY NIGHT-SUNDAY...THE WED NIGHT THROUGH SUNDAY PERIOD WILL MAINLY BE DOMINATED BY A RIDGE OVER THE CENTRAL UNITED STATES. THIS WILL LEAD TO ABOVE NORMAL TEMPS AND BREEZY AFTERNOON SOUTH WINDS FOR THU THROUGH SAT. SOME MODELS DIFFERENCES COME INTO PLAY BY SUNDAY BUT THE GENERAL IDEA IS FOR THE RIDGE TO SHIFT A LITTLE FURTHER EAST BRINGING SOME CHANCES FOR RAIN TO AREAS WEST OF THE RED RIVER. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 650 PM CDT SUN SEP 21 2014 VFR CONDITIONS AND LIGHT WINDS TONIGHT. WINDS TURN SOUTHERLY TOMORROW AT OR UNDER 10KT. WE WILL HAVE TO MONITOR FOG POTENTIAL WITH HIGH PRESSURE OVERHEAD TONIGHT...BUT FOR NOW CONFIDENCE LOW IN POTENTIAL. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...TG LONG TERM...GODON/TG AVIATION...DK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
710 AM CDT SAT SEP 20 2014 .UPDATE... ISSUED AT 707 AM CDT SAT SEP 20 2014 NO CHANGES WERE MADE AS TIMING OF PRECIP SEEMS GOOD BASED ON LATEST RAP AND 06Z NAM. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 357 AM CDT SAT SEP 20 2014 TO START THE DAY...WILL HAVE SOME LOW CLOUDS IN PARTS OF NW MN AND PATCHY CLOUDS AND FOG IN NE ND. BIG ISSUE TODAY IS UPSTREAM VORT MAX IN EAST CENTRAL ALBERTA THAT WILL MOVE SOUTHEAST INTO WESTERN ND AT 18Z AND THEN INTO WEST CNTRL MN AT 00Z SUN. VERY STRONG MID AND UPPER LEVEL FORCING WITH A 80 KT 500 MB JET AND 130 KT 300 MB JET WITH THIS VORT...ALONG WITH STRONG UPPER LEVEL DIVERGENCE CENTERED OVER THE RED RIVER VALLEY EARLY THIS AFTN. SPC WRF AND RUC AND LOCAL WFO FGF WRF ALL INDICATE ABOUT THE SAME SCENARIO WITH A POTENTIAL SQUALL LINE ORGANIZING OVER NE ND NEAR NOON-EARLY AFTN AND MOVING EAST-SOUTHEAST INTO MINNESOTA EARLY TO MID AFTN. PEAK OF ACTIVITY VIA RADAR PROGS FROM SPC WRF WOULD INDICATE AREAS FROM ROSEAU TO DETROIT LAKES IN THE PRIME ZONE THEN LINE WILL MOVE EAST AND WEAKEN TOWARD 00Z JUST EAST OF THE FCST AREA. SPC DAY 1 HAS MUCH OF THE AREA IN SLIGHT RISK USING THE AFOREMENTIONED PARAMTERS. ONE DOWNSIDE IS THAT THE LOW LEVELS WILL BE MUCH COOLER THAN YESTERDAY AND THUS INSTABILITY PARAMETERS WILL BE PRETTY WEAK WITH BARELY BELOW 0C SHOWWALTERS WITH SYSTEM. IT IS EXPECTED MID AND UPPER LEVEL DYNAMICS WILL OVERCOME THIS. WIND SEEMS TO BE THE MAIN THREAT AS 850 MB WINDS INCREASE TO 45 KTS FOR A TIME MID AFTN JUST EAST OF THE RRV AS LINE MOVES THROUGH. THUS ANY STRONG STORM LINE COULD EASILY MIX THIS DOWN. HAIL ALSO A THREAT DUE TO COOLING AT 500 MB WITH SYSTEM AS TEMPS AT THAT LEVEL DROP TO -20C. TORNADO THREAT WOULD SEEM LOW...DUE TO LACK OF SFC LOW UNLIKE YESTERDAY. DID INCLUDE SEVERE WORDING FOR A 2-3 HOUR PERIOD ACROSS THE RRV INTO MN IN RISK AREA BASED ON TIMING FROM SPC WRF/RUC. SYSTEM CLEARS EAST TONIGHT...LINGERING CLOUDS IN LAKE OF THE WOODS BUT CLEARING ELSEWHERE. SUNDAY WILL SEE CLOUDS MOST PROMINENT IN MN FCST AREA UNDER DEPARTING 500 MB TROUGH. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 357 AM CDT SAT SEP 20 2014 SUN NIGHT INTO MONDAY WILL FEATURE GENERALLY CLEAR SKY AS HIGH PRESSURE AND DRY AIRMASS MOVES IN. FOR TUESDAY THROUGH FRIDAY... LONG WAVE RIDGE OVER WESTERN NORTH AMERICA SHIFTS TO EASTERN NORTH AMERICA BY THE END OF THE PERIOD. LONG WAVE UPPER RIDGE PRODUCES MUCH ABOVE NORMAL HEIGHTS BY THE END OF THE PERIOD. SHORT WAVE TROUGH OFF THE CA COAST IS FORECAST TO MOVE ACROSS ITO THE NORTHERN PLAINS BY LATE TUE INTO WED. THE GFS AND ECMWF ARE SIMILAR IN TIMING AT 84 HOURS THE GFS BECOMES THE FASTER SOLUTION ON THU AND FRI. WILL PREFER THE ECMWF. TWEAKED POPS UP A LITTLE ON TUE. LITTLE CHANGE TO TEMPS...INCREASE TEMPS BY A DEGREE ON THU. ESSENTIALLY NO CHANGES FROM PREVIOUS FORECAST PACKAGE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 707 AM CDT SAT SEP 20 2014 TYPICAL EARLY MORNING AREA OF LOW END MVFR/IFR CIGS ALONG WITH PATCHES OF FOG IN THE RED RIVER VALLEY INTO MINNESOTA. THE LOW CLOUDS/FOG WILL MIX OUT BUT REPLACE BY MID AND HIGH LEVEL MOISTURE FROM UPPER WAVE MOVING SOUTHEAST. TRIED TO TIME BEST RISK OF TSTMS AT TAF SITES....MOSTLY VERY LATE MORNING IN DVL AND EARLY AFTN IN GFK AND MID AFTN TVF-FAR AND LATE AFTN BJI. WINDS MAIN ISSUE WITH THESE STORMS AS A WEST-SOUTHWEST WIND TURNS NORTHWEST WITH LIKELY HIGH GUSTS FOR A TIME WITH LINE OF SHOWERS/STORMS. WINDS WILL DIMINISH THIS EVE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...RIDDLE LONG TERM...HOPPES/RIDDLE AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
105 AM CDT SAT SEP 20 2014 .UPDATE... ISSUED AT 105 AM CDT SAT SEP 20 2014 THE INHERITED FORECAST IS MAINLY ON TRACK FOR THE EARLY MORNING FORECAST UPDATE. DID MODIFY POPS FOR THE NEXT S/WV SET TO MOVE THROUGH THE NORTHERN PLAINS THIS MORNING. SCALED BACK ON PRECIPITATION CHANCES TILL 09Z...HIGHER POPS ACROSS THE NORTH DURING THE MORNING HOURS LATE TONIGHT PAST DAYBREAK SATURDAY. UPDATE ISSUED AT 952 PM CDT FRI SEP 19 2014 CONVECTION HAS ALL BUT ENDED ACROSS WESTERN AND CENTRAL NORTH DAKOTA WITH THE SETTING SUN. STILL AN ISOLATED SHOWER ALONG THE MISSOURI RIVER BORDERING MONTANA...BUT THIS ACTIVITY HAS BEEN DECREASING AND EXPECT THIS TO CONTINUE. THUS HAVE REMOVED POPS FOR THIS EVENING. MODELS SUGGEST NEXT WAVE WILL BE MOVING INTO SOUTHEAST SASKATCHEWAN LATE TONIGHT AND HAVE UTILIZED THE 01 UTC RAP AS A GUIDE FOR TIMING OF THE PRECIPITATION WITH THIS WAVE. BROUGHT SHOWERS INTO THE FAR NORTHWEST AROUND 09-10 UTC WITH SHOWERS AND ISOLATED THUNDERSTORMS GENERALLY ALONG AND NORTH OF A LINE FROM WILLISTON TO GARRISON TO JAMESTOWN ON SATURDAY...WITH PRECIPITATION ENDING IN THE SOUTHERN JAMES RIVER VALLEY BY MID TO LATE AFTERNOON. UPDATE ISSUED AT 642 PM CDT FRI SEP 19 2014 ISOLATED THUNDERSTORMS CONTINUE TO TRACK SOUTHEAST ACROSS BOTTINEAU AND MCHENRY COUNTIES IN NORTH CENTRAL NORTH DAKOTA. STRONGER CELLS HAVE REMAINED OVER NORTHEAST NORTH DAKOTA NEAR THE SURFACE LOW PRESSURE SYSTEM. GUSTY NORTHWEST WINDS BEHIND THE LOW SHOULD DIMINISH EARLY THIS EVENING ACROSS THE WEST AND CENTRAL. UPDATED SKY COVER AND POP GRIDS BASED ON LATEST RADAR AND SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT UPDATES NEEDED. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 230 PM CDT FRI SEP 19 2014 SCATTERED THUNDERSTORMS NORTH THIS AFTERNOON AND EVENING...AND WINDY CONDITIONS WITH RAIN SHOWERS SATURDAY HIGHLIGHT THE SHORT TERM FORECAST. THE 12 UTC GLOBAL SUITE AND THE 14-15 UTC HRRR ITERATIONS CONTINUE TO SUGGEST SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON THROUGH SUNSET ALONG AND NORTH OF THE US HIGHWAY 2 CORRIDOR...BEHIND A WEAK SECONDARY COLD FRONT WITH 50S SURFACE DEWPOINTS IN TRAIL. SEVERE CONVECTION IS NOT ANTICIPATED AND WILL FADE QUICKLY WITH SUNSET. FOR SATURDAY...THE SHORTWAVE CURRENTLY ACROSS WESTERN ALBERTA THIS AFTERNOON IS FORECAST TO PROPAGATE ACROSS NORTH DAKOTA DURING THE MORNING AND EARLY AFTERNOON. THE HIGHEST POPS ARE FOCUSED ACROSS THE NORTH CENTRAL AND EAST...WITH THE SOUTHWEST FORECAST TO BE PRECIPITATION FREE. DID INCLUDE AN ISOLATED THUNDER MENTION WITH WEAK INSTABILITY. SATURDAY WILL BE WINDY WITH A TIGHT PRESSURE GRADIENT BETWEEN THE SURFACE HIGH IN MONTANA AND LOW PRESSURE OVER LAKE WINNIPEG. THE 12 UTC NAM/GFS BUFR SOUNDINGS DEPICT 30-35 KTS OF FLOW AT THE TOP OF THE MIXED LAYER...WHICH EQUATES TO BRISK NORTHWEST WINDS THAT REMAIN BELOW ADVISORY CRITERIA. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 230 PM CDT FRI SEP 19 2014 THE LONG TERM BEGINS WITH THE WESTERN RIDGE OVER THE ROCKIES AND A CUTOFF LOW OVER CALIFORNIA/NEVADA...WITH NORTHWEST FLOW ALOFT OVER THE DAKOTAS. THE UPPER RIDGE MOVES EAST INTO THE PLAINS THROUGH THE WEEKEND...WITH THE CUTOFF LOW LIFTING NORTHEASTWARD SLOWLY COINCIDENT WITH THE UPPER RIDGE`S EASTWARD MOVEMENT. DURING THIS TIME...SURFACE HIGH PRESSURE WILL BRING MILD AND DRY AIR TO WESTERN AND CENTRAL NORTH DAKOTA. DRY THROUGH MONDAY NIGHT. LOW TEMPERATURES SUNDAY MORNING FROM THE UPPER 30S WEST TO 40S CENTRAL...WARMING TO LOWS IN THE 50S BY TUESDAY MORNING. HIGHS SUNDAY UPPER 60S TO LOWER 70S...AND IN THE 70S ON MONDAY. BY TUESDAY THE MEANDERING CUTOFF UPPER LEVEL LOW IS FORECAST TO BE OVER THE NORTHERN/CENTRAL PLAINS...BRINGING A CHANCE OF SHOWERS OR THUNDERSTORMS TO THE FORECAST AREA TUESDAY AND WEDNESDAY. MEANWHILE A LONGWAVE TROUGH DEVELOPS OVER THE WEST COAST...AND UPSTREAM RIDGING OCCURS OVER THE PLAINS AHEAD OF THIS SYSTEM...LEADING TO A DRY END OF THE WEEK. CONTINUED MILD WITH LOWS IN THE 50S...AND HIGHS IN THE 70S TO AROUND 80. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 105 AM CDT SAT SEP 20 2014 VFR CONDITIONS EXPECTED ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE 06Z TAF PERIOD. SCATTERED VFR CLOUDINESS THROUGH SATURDAY MORNING THROUGH EARLY AFTERNOON...BASES AROUND 7-10KFT TRACKING MAINLY FROM KMOT TO KJMS AS ANOTHER QUICK MOVING SYSTEM MOVES THROUGH. WILL MENTION A VCSH AT KISN-KMOT-KJMS SATURDAY MORNING. NORTHWEST FLOW WILL INCREASE AGAIN SATURDAY AFTERNOON WITH GUSTS TO AROUND 30-35 KTS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...AYD LONG TERM...JV AVIATION...NH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
557 PM EDT SAT SEP 20 2014 .SYNOPSIS... A STRONG COLD FRONT WILL SHIFT THROUGH THE GREAT LAKES TONIGHT AND SUNDAY WITH THE THREAT FOR SHOWERS AND THUNDERSTORMS. A MILD NIGHT IS IN STORE AHEAD OF THE FRONT TONIGHT...WITH LOWS IN THE 60S. COOLER AIR WILL DROP IN QUICKLY BEHIND THE FRONT SUNDAY AFTERNOON AND NIGHT...LEADING TO SEVERAL NIGHTS WITH LOWS IN THE 40S...WITH PERHAPS SOME UPPER 30S IN OUTLYING AREAS. MUCH OF THE WORK WEEK WILL FEATURE STRONG HIGH PRESSURE...WHICH WILL BRING MILD DAYS...COOL NIGHTS...AND LOW HUMIDITY. PLENTY OF SUN IS EXPECTED THROUGH THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... UPDATE...SPED UP ARRIVAL OF RAIN CHANCES BY AN HOUR OR TWO BASED ON TIME TRENDS FROM RADAR ON NOW WELL-DEVELOPED LINE OF CONVECTION FROM NERN IND BACK TO WCNTL IND. MOST CONCENTRATED N-S PORTION OF LINE WITH HISTORY OF WIND DAMAGE WILL PASS NORTH OF OUR AREA THROUGH EARLY EVENING. REST OF LINE SEEMS TO BE STRUGGLING TO BE SEVERE...AND WE/RE WATCHING PORTION OF THE LINE FROM LOGANSPORT BACK TO IL BORDER AS THE PORTION THAT WILL AFFECT US. GUST FRONT NOW KICKING SWRD FROM SEGMENT OF LINE FROM COLUMBIA CITY BACK TO LOGANSPORT SO THIS PORTION OF LINE LIKELY TO WEAKEN. MESOA OVER IND/OH SHOWS INSTBY DECREASING WITH EWRD EXTENT INTO ILN CWA AND WITH SUNSET APPROACHING STILL THINK OVERALL SEVERE THREAT IS MARGINAL. DID UPDATE HWO TO GIVE HEADS UP TO WCNTL OHIO/ECNTL IND COUNTIES THAT A GUSTY/WEAKENING LINE OF STORMS IS LIKELY 00Z-02Z. REF MCD#1741 THAT A NEW WATCH /IF ISSUED/ MAY GRAB A COUPLE OF OUR FAR NWRN COUNTIES. ALSO PULLED RAIN CHANCES IN NRN KY AS CUMULUS/PVS SHRA DOWN THERE HAVE LARGELY DISSIPATED. PREVIOUS DISCUSSION -> SEVERAL FOCI FOR PRECIPITATION NOW THROUGH SUNRISE ON SUNDAY MORNING. FIRST...IS IN A RELATIVELY NARROW AXIS OF HIGHER THETA-E THAT RUNS NORTHEAST ALONG THE OHIO RIVER INTO THE CVG AREA THIS AFTERNOON. BOUNDARY LAYER DWPTS HAVE WITHSTOOD MIXING TO REMAIN IN THE MID 60S YIELDING SOME MARGINAL MLCAPE FROM 200-500 J/KG. CONFLUENT FLOW/VERY WEAK CONVERGENCE HAS LED TO THIS EXTENSION OF BUOYANCY AND SOME ISOLD SHRA HAVE DEVELOPED IN THIS AXIS AND WILL CONTINUE TO DO SO THROUGH ABT 7-8 PM TIED STRONGLY TO THE BOUNDARY LAYER FLOW/INSTBY. HAVE PLACED A SMALL RAIN CHANCE IN PARTS OF OUR NRN KY COUNTIES FOR THIS EVENING TO ACCOUNT FOR THIS THREAT. LARGER CONCERN IS STRONG COLD FRONT WHICH IS SHIFTING THROUGH WI/IA/NRN IL ATTM ATTENDANT TO A COUPLE OF HEIGHT FALL CENTERS...ONE IN WI THIS AFTN AND ANOTHER VERY COMPACT ONE IN ERN ND. LOW LEVEL FORCING IS STRONG WITH THE FRONT AND ASSOCIATED PRE- FRONTAL TROUGH...AND DEEP LAYER FLOW IS INCREASING AS THE THROUGH AMPLIFIES WITH TIME TONIGHT. CONVECTION HAS RECENTLY ERUPTED AS OF 19Z JUST SOUTH OF CHICAGO AND SPC WATCH #504 ACCOMPANIES THIS INCREASE IN CONVECTION OFF TO OUR NW. ACCORDING TO 20.12Z AWR-WRF...20.09Z SREF...AND MULTIPLE WELL-AGREED UPON HRRR RUNS...A RATHER ROBUST LINE OF STORMS WILL DEVELOP ALONG/AHEAD OF THE FRONT OVER THE NEXT FEW HOURS AND PUSH EAST/NORTHEAST. ORIENTATION/MAGNITUDE /30+KTS BY TONIGHT/ OF 0-3KM SHEAR VECTOR IS FAVORABLE FOR SOME DURATION/ORGANIZATION TO LINE SEGMENTS WHICH CAN ORIENT IN MORE N-S FASHION OR SOME VARIATION OF THAT. NOT SURPRISINGLY...HRRR RUNS HAVE DEMONSTRATED SPORADIC SWATHS OF DAMAGING WIND GUSTS > 50KTS ACROSS NRN IND POTENTIALLY INVOLVING NWRN/WCNTL OH LATER THIS EVE /AFTER 10 PM OR SO/. REALLY LIKE THE 5% WIND CONTOUR INTO WCNTL OHIO BASED ON THE HRRR/ARW WRF SOLUTIONS SHOWING A WEAKENING ORGANIZED LINE COMING INTO OUR AREA AROUND 10 PM...PERHAPS WITH SOME 40-50 MPH WINDS. THIS FITS CURRENT MESOA WHICH HAS MINIMUM OF INSTBY IN WRN OH DUE TO MIXED DWPTS IN THE 50S...SO LINE SHOULD WEAKEN CONSIDERABLY AS IT CROSSES INTO OHIO...DESPITE BRINGING A MODEST INCREASE IN MOISTURE VIA ADVECTION. STRUGGLED A LOT WITH RAIN CHANCES...FEEL CONFIDENT ENOUGH FOR LIKELY RAIN CHANCES WITH DYING LINE INTO ABOUT THE NWRN 1/2 OF OUR FORECAST AREA...BUT ALL CAMS/PARAMETRIZED DATA SHOWING ACTIVITY BECOMING MORE SCT WITH TIME AS NIGHT WEARS ON. SO RAIN CHANCES OVERNIGHT RANGE FROM A LOW CONFIDENCE 20% IN FAR SOUTH/EAST UP TO A 70% CHANCE OR SO IN WCNTL OH. ALL WILL DEPEND HOW QUICKLY THE INCOMING LINE WEAKENS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... FIRST HEIGHT FALL CENTER MENTIONED ABOVE PULLS EAST OF THE AREA SUNDAY MORNING TAKING PRIMARY CONVERGENCE/PREFRONTAL TROUGH WITH IT THROUGH THE MORNING. RESIDUAL SHOWERS/STORMS TO CROSS THE AREA IN THE MORNING AND THEN SCT STORMS WILL BEGIN TO BUBBLE ALONG THIS BOUNDARY LATE MORNING/EARLY AFTERNOON AND LIKELY IN OUR FAR SOUTH/EAST OR JUST OUT OF OUR AREA. RATHER IMPRESSIVE/NARROW DRY SLOT SHOULD WRAP IN LATE MORNING/EARLY AFTERNOON WITH SOME SUNSHINE BEFORE STRONG CAA SETS IN DURING THE AFTERNOON WITH THE PASSAGE OF SECONDARY FRONT. WITH SHALLOW INSTBY DEVELOPING...COULD SEE SOME SCT SHRA DEVELOP WITH THIS FEATURE WHICH WAS ALREADY WELL HANDLED BY PVS FORECASTER. THIS MOST LIKELY ACROSS OUR NORTH CLOSER TO STRONG/COMPACT SHORTWAVE DIGGING ACROSS NRN OH. DON/T EXPECT MUCH IF ANY THUNDER AFTER ABOUT 18Z...AS INSTBY BECOMES TOO SHALLOW FOR CHARGE SEPARATION. WILL DEFINITELY A BE A CHANGEABLE /AUTUMN-LIKE DAY DESPITE MAX TEMPS IN THE 70S. WINDS WILL BECOME BREEZY/GUSTY IN THE AFTN AS THE COLD ADVECTION ARRIVES AND CHANGEABLE SKY WITH THE DRY SLOT TO LOWER CLOUDS ALONG/BEHIND THE SECONDARY SURFACE FRONT. AS THIS ACTION ALL CLEARS THE CWA SUNDAY NIGHT AND STRONG HIGH PRESSURE BUILDS IN...A VERY CHILLY NIGHT IN STORE WITH LOWS WELL INTO THE 40S IN OUR INDIANA/WRN OHIO COUNTIES AS 925MB TEMPS DROP TO +5C IN THIS AREA BY SUNRISE ON MONDAY. SHOULD SEE A SLOW DECREASE IN LOW CLOUDS THROUGH THE NIGHT AND LESSENING WINDS AS WELL...GIVEN THE DEGREE OF COLD AIR INBOUND...AM A LITTLE WORRIED I AM CLEARING THE SKIES A LITTLE TOO QUICKLY AND STRATOCUMULUS MAY BE MORE WIDESPREAD. MONDAY BRINGS 1024MB SURFACE HIGH PRESSURE SPRAWLING INTO THE GREAT LAKES AND CENTERED NEAR CHICAGO BY MONDAY EVENING. SHOULD BE PLENTY OF SUNSHINE WITH DEWPTS IN THE 40S. CONTINUED WEAK CAA SHOULD KEEP 925MB TEMPS IN THE +8 TO +10C RANGE WHICH PER CLIMO STUDY SUGGESTS MAX TEMPS IN THE LOW TO MID 60S MOST AREAS...DESPITE PLENTY OF SUN. MONDAY NIGHT WILL BE COLDEST OF THE WEEK AND WOULD NOT BE SURPRISED TO SEE COLD PRONE/OUTLYING SITES TOUCH THE MID TO UPPER 30S AGAIN LIKE DELAWARE/MARYSVILLE ETC DID LAST WEEK. MAY EVEN BE A TOUCH COLDER THIS TIME AROUND. LOW TEMPS THIS NIGHT MAY STILL BE A DEGREE OR TWO TOO WARM IN GOING FORECAST...ESPECIALLY WITH SURFACE HIGH MOVING RIGHT OVERHEAD AT 12Z AND THE VERY DRY PROFILE /PWATS RUNNING 40% OF NORMAL/. AN IDEAL RADIATIONAL COOLING SIGNAL BEING SEEN IN THE DATA. && .LONG TERM /TUESDAY THROUGH SATURDAY/... MID/UPPER LEVEL RIDGE WILL REMAIN IN PLACE ACROSS THE REGION THROUGH THE END OF THE WEEK. THIS WILL RESULT IN DRY CONDITIONS AND FAIRLY SEASONABLE TEMPERATURES THROUGH THE LONG TERM PERIOD. AS THE AIRMASS SLOWLY MODIFIES...HIGH TEMPERATURES WILL GRADUALLY WARM EACH DAY...FROM THE LOW TO MID 70S MID WEEK INTO THE UPPER 70S TO AROUND 80 DEGREES BY THE WEEKEND. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... MVFR CEILINGS PERSIST AT CVG AND LUK...OTHERWISE TAF SITES HAVE VFR. COLD FRONT WILL BE MOVING IN LATE TONIGHT/EARLY SUNDAY. THIS WILL BRING SCATTERED SHOWERS AND POSSIBLY MORE MVFR CEILINGS. KEPT THUNDER OUT FOR NOW SINCE FRONT WILL BE ARRIVING AT A DIURNALLY UNFAVORABLE TIME. WINDS WILL GUST AROUND 20 KNOTS THIS AFTERNOON OUT OF THE SOUTHWEST. GUSTS OVER 20 KNOTS ARE EXPECTED SUNDAY AS DIRECTION SHIFTS TO WEST ALONG THE FRONT. CVG SHOULD SEE CONTINUED GUSTY CONDITIONS AS WINDS BECOME NORTHWEST SUNDAY AFTERNOON BEHIND THE FRONT. OUTLOOK...MVFR CEILINGS POSSIBLE SUNDAY NIGHT. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU SHORT TERM...BINAU LONG TERM...JGL AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
352 PM EDT SAT SEP 20 2014 .SYNOPSIS... A STRONG COLD FRONT WILL SHIFT THROUGH THE GREAT LAKES TONIGHT AND SUNDAY WITH THE THREAT FOR SHOWERS AND THUNDERSTORMS. A MILD NIGHT IS IN STORE AHEAD OF THE FRONT TONIGHT...WITH LOWS IN THE 60S. COOLER AIR WILL DROP IN QUICKLY BEHIND THE FRONT SUNDAY AFTERNOON AND NIGHT...LEADING TO SEVERAL NIGHTS WITH LOWS IN THE 40S...WITH PERHAPS SOME UPPER 30S IN OUTLYING AREAS. MUCH OF THE WORK WEEK WILL FEATURE STRONG HIGH PRESSURE...WHICH WILL BRING MILD DAYS...COOL NIGHTS...AND LOW HUMIDITY. PLENTY OF SUN IS EXPECTED THROUGH THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... SEVERAL FOCI FOR PRECIPITATION NOW THROUGH SUNRISE ON SUNDAY MORNING. FIRST...IS IN A RELATIVELY NARROW AXIS OF HIGHER THETA-E THAT RUNS NORTHEAST ALONG THE OHIO RIVER INTO THE CVG AREA THIS AFTERNOON. BOUNDARY LAYER DWPTS HAVE WITHSTOOD MIXING TO REMAIN IN THE MID 60S YIELDING SOME MARGINAL MLCAPE FROM 200-500 J/KG. CONFLUENT FLOW/VERY WEAK CONVERGENCE HAS LED TO THIS EXTENSION OF BUOYANCY AND SOME ISOLD SHRA HAVE DEVELOPED IN THIS AXIS AND WILL CONTINUE TO DO SO THROUGH ABT 7-8 PM TIED STRONGLY TO THE BOUNDARY LAYER FLOW/INSTBY. HAVE PLACED A SMALL RAIN CHANCE IN PARTS OF OUR NRN KY COUNTIES FOR THIS EVENING TO ACCOUNT FOR THIS THREAT. LARGER CONCERN IS STRONG COLD FRONT WHICH IS SHIFTING THROUGH WI/IA/NRN IL ATTM ATTENDANT TO A COUPLE OF HEIGHT FALL CENTERS...ONE IN WI THIS AFTN AND ANOTHER VERY COMPACT ONE IN ERN ND. LOW LEVEL FORCING IS STRONG WITH THE FRONT AND ASSOCIATED PRE- FRONTAL TROUGH...AND DEEP LAYER FLOW IS INCREASING AS THE THROUGH AMPLIFIES WITH TIME TONIGHT. CONVECTION HAS RECENTLY ERUPTED AS OF 19Z JUST SOUTH OF CHICAGO AND SPC WATCH #504 ACCOMPANIES THIS INCREASE IN CONVECTION OFF TO OUR NW. ACCORDING TO 20.12Z AWR-WRF...20.09Z SREF...AND MULTIPLE WELL-AGREED UPON HRRR RUNS...A RATHER ROBUST LINE OF STORMS WILL DEVELOP ALONG/AHEAD OF THE FRONT OVER THE NEXT FEW HOURS AND PUSH EAST/NORTHEAST. ORIENTATION/MAGNITUDE /30+KTS BY TONIGHT/ OF 0-3KM SHEAR VECTOR IS FAVORABLE FOR SOME DURATION/ORGANIZATION TO LINE SEGMENTS WHICH CAN ORIENT IN MORE N-S FASHION OR SOME VARIATION OF THAT. NOT SURPRISINGLY...HRRR RUNS HAVE DEMONSTRATED SPORADIC SWATHS OF DAMAGING WIND GUSTS > 50KTS ACROSS NRN IND POTENTIALLY INVOLVING NWRN/WCNTL OH LATER THIS EVE /AFTER 10 PM OR SO/. REALLY LIKE THE 5% WIND CONTOUR INTO WCNTL OHIO BASED ON THE HRRR/ARW WRF SOLUTIONS SHOWING A WEAKENING ORGANIZED LINE COMING INTO OUR AREA AROUND 10 PM...PERHAPS WITH SOME 40-50 MPH WINDS. THIS FITS CURRENT MESOA WHICH HAS MINIMUM OF INSTBY IN WRN OH DUE TO MIXED DWPTS IN THE 50S...SO LINE SHOULD WEAKEN CONSIDERABLY AS IT CROSSES INTO OHIO...DESPITE BRINGING A MODEST INCREASE IN MOISTURE VIA ADVECTION. STRUGGLED A LOT WITH RAIN CHANCES...FEEL CONFIDENT ENOUGH FOR LIKELY RAIN CHANCES WITH DYING LINE INTO ABOUT THE NWRN 1/2 OF OUR FORECAST AREA...BUT ALL CAMS/PARAMETRIZED DATA SHOWING ACTIVITY BECOMING MORE SCT WITH TIME AS NIGHT WEARS ON. SO RAIN CHANCES OVERNIGHT RANGE FROM A LOW CONFIDENCE 20% IN FAR SOUTH/EAST UP TO A 70% CHANCE OR SO IN WCNTL OH. ALL WILL DEPEND HOW QUICKLY THE INCOMING LINE WEAKENS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... FIRST HEIGHT FALL CENTER MENTIONED ABOVE PULLS EAST OF THE AREA SUNDAY MORNING TAKING PRIMARY CONVERGENCE/PREFRONTAL TROUGH WITH IT THROUGH THE MORNING. RESIDUAL SHOWERS/STORMS TO CROSS THE AREA IN THE MORNING AND THEN SCT STORMS WILL BEGIN TO BUBBLE ALONG THIS BOUNDARY LATE MORNING/EARLY AFTERNOON AND LIKELY IN OUR FAR SOUTH/EAST OR JUST OUT OF OUR AREA. RATHER IMPRESSIVE/NARROW DRY SLOT SHOULD WRAP IN LATE MORNING/EARLY AFTERNOON WITH SOME SUNSHINE BEFORE STRONG CAA SETS IN DURING THE AFTERNOON WITH THE PASSAGE OF SECONDARY FRONT. WITH SHALLOW INSTBY DEVELOPING...COULD SEE SOME SCT SHRA DEVELOP WITH THIS FEATURE WHICH WAS ALREADY WELL HANDLED BY PVS FORECASTER. THIS MOST LIKELY ACROSS OUR NORTH CLOSER TO STRONG/COMPACT SHORTWAVE DIGGING ACROSS NRN OH. DON/T EXPECT MUCH IF ANY THUNDER AFTER ABOUT 18Z...AS INSTBY BECOMES TOO SHALLOW FOR CHARGE SEPARATION. WILL DEFINITELY A BE A CHANGEABLE /AUTUMN-LIKE DAY DESPITE MAX TEMPS IN THE 70S. WINDS WILL BECOME BREEZY/GUSTY IN THE AFTN AS THE COLD ADVECTION ARRIVES AND CHANGEABLE SKY WITH THE DRY SLOT TO LOWER CLOUDS ALONG/BEHIND THE SECONDARY SURFACE FRONT. AS THIS ACTION ALL CLEARS THE CWA SUNDAY NIGHT AND STRONG HIGH PRESSURE BUILDS IN...A VERY CHILLY NIGHT IN STORE WITH LOWS WELL INTO THE 40S IN OUR INDIANA/WRN OHIO COUNTIES AS 925MB TEMPS DROP TO +5C IN THIS AREA BY SUNRISE ON MONDAY. SHOULD SEE A SLOW DECREASE IN LOW CLOUDS THROUGH THE NIGHT AND LESSENING WINDS AS WELL...GIVEN THE DEGREE OF COLD AIR INBOUND...AM A LITTLE WORRIED I AM CLEARING THE SKIES A LITTLE TOO QUICKLY AND STRATOCUMULUS MAY BE MORE WIDESPREAD. MONDAY BRINGS 1024MB SURFACE HIGH PRESSURE SPRAWLING INTO THE GREAT LAKES AND CENTERED NEAR CHICAGO BY MONDAY EVENING. SHOULD BE PLENTY OF SUNSHINE WITH DEWPTS IN THE 40S. CONTINUED WEAK CAA SHOULD KEEP 925MB TEMPS IN THE +8 TO +10C RANGE WHICH PER CLIMO STUDY SUGGESTS MAX TEMPS IN THE LOW TO MID 60S MOST AREAS...DESPITE PLENTY OF SUN. MONDAY NIGHT WILL BE COLDEST OF THE WEEK AND WOULD NOT BE SURPRISED TO SEE COLD PRONE/OUTLYING SITES TOUCH THE MID TO UPPER 30S AGAIN LIKE DELAWARE/MARYSVILLE ETC DID LAST WEEK. MAY EVEN BE A TOUCH COLDER THIS TIME AROUND. LOW TEMPS THIS NIGHT MAY STILL BE A DEGREE OR TWO TOO WARM IN GOING FORECAST...ESPECIALLY WITH SURFACE HIGH MOVING RIGHT OVERHEAD AT 12Z AND THE VERY DRY PROFILE /PWATS RUNNING 40% OF NORMAL/. AN IDEAL RADIATIONAL COOLING SIGNAL BEING SEEN IN THE DATA. && .LONG TERM /TUESDAY THROUGH SATURDAY/... MID/UPPER LEVEL RIDGE WILL REMAIN IN PLACE ACROSS THE REGION THROUGH THE END OF THE WEEK. THIS WILL RESULT IN DRY CONDITIONS AND FAIRLY SEASONABLE TEMPERATURES THROUGH THE LONG TERM PERIOD. AS THE AIRMASS SLOWLY MODIFIES...HIGH TEMPERATURES WILL GRADUALLY WARM EACH DAY...FROM THE LOW TO MID 70S MID WEEK INTO THE UPPER 70S TO AROUND 80 DEGREES BY THE WEEKEND. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... MVFR CEILINGS PERSIST AT CVG AND LUK...OTHERWISE TAF SITES HAVE VFR. COLD FRONT WILL BE MOVING IN LATE TONIGHT/EARLY SUNDAY. THIS WILL BRING SCATTERED SHOWERS AND POSSIBLY MORE MVFR CEILINGS. KEPT THUNDER OUT FOR NOW SINCE FRONT WILL BE ARRIVING AT A DIURNALLY UNFAVORABLE TIME. WINDS WILL GUST AROUND 20 KNOTS THIS AFTERNOON OUT OF THE SOUTHWEST. GUSTS OVER 20 KNOTS ARE EXPECTED SUNDAY AS DIRECTION SHIFTS TO WEST ALONG THE FRONT. CVG SHOULD SEE CONTINUED GUSTY CONDITIONS AS WINDS BECOME NORTHWEST SUNDAY AFTERNOON BEHIND THE FRONT. OUTLOOK...MVFR CEILINGS POSSIBLE SUNDAY NIGHT. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU SHORT TERM...BINAU LONG TERM...JGL AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
647 AM EDT SAT SEP 20 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF TO THE EAST TODAY AS A COLD FRONT APPROACHES FROM THE NORTHWEST. THE COLD FRONT WILL MOVE ACROSS THE AREA LATE TONIGHT AND SUNDAY. HIGH PRESSURE WILL THEN BECOME REESTABLISHED FOR MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NEAR TERM MODELS...SUCH AS THE HRRR AND RAP...CONTINUE TO FORECAST THE DEVELOPMENT OF LOWER LEVEL CLOUDS...4 K FT TO 6 KT ACROSS THE SRN CWFA TOWARD MORNING. THIS DEVELOPMENT IS DUE TO WEAK ISENTROPIC LIFT OCCURRING AROUND DEPARTING HIGH PRESSURE. THERE MAY BE ENOUGH SHALLOW INSTABILITY IN THIS DECK TO WARRANT A LOW CHANCE POP ALONG AND SOUTH OF THE OHIO RIVER THROUGH THE MORNING HOURS. OTHERWISE...WE SHOULD SEE PARTLY TO MOSTLY SUNNY SKIES TODAY OUT AHEAD OF A COLD FRONT WHICH WILL MAKE IN ROADS TOWARD OUR REGION TONIGHT. INCREASING SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND THE FRONT WILL BOOST TEMPERATURES INTO THE UPPER 70S TO THE LOWER 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... HAVE AGAIN USED A BLEND OF THE ECMWF/GFS...ALONG WITH CONVECTION ALLOWING MODELS...TO HONE IN ON THE PROSPECTS OF PCPN TONIGHT INTO SUNDAY NIGHT. A SERIES OF S/WVS WILL DIG EAST/SOUTHEAST THROUGH THE GREAT LAKES TONIGHT INTO SUNDAY NIGHT...WHICH WILL EVENTUALLY ESTABLISH A LONG WAVE MID LEVEL TROUGH OVER ERN CANADA SOUTHWARD INTO THE ERN U.S. BY MONDAY MORNING. THE FIRST WAVE...ALONG WITH PREFRONTAL CONVERGENCE...IS EXPECTED TO RESULT IN SHOWERS/THUNDERSTORMS TO OUR NORTHWEST LATE THIS AFTERNOON INTO EARLY THIS EVENING. MODELS CONTINUE TO SUGGEST THAT AS THIS ACTIVITY PROPAGATES SOUTHEAST INTO OUR AREA TONIGHT OUT AHEAD OF A COLD FRONT...IT WILL UNDERGO A WEAKENING TREND. RAPIDLY DECREASING INSTABILITY...WEAKENING LOW LEVEL FORCING...ALONG WITH WEAKENING UPPER LEVEL SUPPORT ARE THE REASONS THAT THIS IS FORECAST TO OCCUR. AS A RESULT...HAVE PLACED THE HIGHEST POPS TONIGHT OVER THE FAR NW...DECREASING THE THREAT TO JUST 30 AND 40 PERCENT THROUGH THE REMAINDER OF THE REGION TOWARD SUNDAY MORNING. ON SUNDAY...ANOTHER EMBEDDED S/WV WILL APPROACH FROM THE NORTHWEST WHILE THE COLD FRONT PUSHES EAST/SOUTHEAST THROUGH THE REGION. WITH THE FASTER TIMING OF THE GFS/ECMWF...BELIEVE ANY SHOWER/THUNDERSTORM REDEVELOPMENT SHOULD OCCUR JUST EAST/SOUTHEAST OF THE AREA. IN THE WAKE OF THE FRONT...AND BEFORE THE ARRIVAL OF THE NEXT S/WV...WE SHOULD SEE A POCKET OF DRY WEATHER ALONG WITH PARTLY TO MOSTLY SUNNY SKIES. HIGHS ON SUNDAY WILL BE TRICKY AS CAA WILL BE ONGOING THROUGH THE DAY. WILL FORECAST LOWER 70S NORTHWEST TO THE UPPER 70S SOUTHERN/SOUTHEAST. FOR SUNDAY NIGHT...AFOREMENTIONED S/WV WILL PASS THROUGH THE REGION ALONG WITH A SFC TROF AXIS. THERE COULD BE ENOUGH INSTABILITY WITH THIS FEATURE TO BRING A FEW SPOTTY SHOWERS TO THE NRN ZONES SUNDAY EVENING. BUT AS TIME WEARS ON AND INSTABILITY WANES...THE THREAT SHOULD RELEGATE ITSELF TO OUR NE TOWARD CENTRAL/EASTERN LAKE ERIE. PARTLY CLOUD SKIES WILL UNDERGO A CLEARING TREND...ESPECIALLY WEST OVERNIGHT. LOWS WILL DROP INTO THE MID 40S NORTHWEST TO THE LOWER 50S SOUTHEAST. FOR MONDAY INTO MONDAY NIGHT...MID LEVEL TROUGH WILL MOVE EAST AS A MID LEVEL RIDGE BUILDS NORTHWARD INTO THE MIDDLE AND UPPER MS RIVER VALLEY. AT THE SURFACE...A SPRAWLING AREA OF HIGH PRESSURE WILL BE FOUND AS IT SETTLES RIGHT OVER THE OHIO VALLEY BY TUESDAY MORNING. CLOUDS WILL CONTINUE TO DECREASE THROUGH THE PERIOD WITH CLEAR SKIES EXPECTED BY MONDAY NIGHT. AFTER COOL TEMPERATURES RANGING FROM THE LOWER 60S NORTH TO THE UPPER 60S SOUTH...OVERNIGHT LOWS WILL DIP INTO THE UPPER 30S AND LOWER 40S BY TUESDAY MORNING. ON TUESDAY...WITH THE HIGH REMAINING IN PLACE...SKIES WILL BE SUNNY. HIGHS WILL WARM INTO THE UPPER 60S TO THE LOWER 70S. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH THE LONG TERM. TEMPERATURES WILL SLOWLY WARM THROUGH THE LONG TERM WITH HIGH TEMPERATURES BY FRIDAY EXPECTED TO BE IN THE MID TO UPPER 70S. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... ALTHOUGH THE MAJORITY OF THE FORECAST PERIOD IS EXPECTED TO BE VFR...THERE ARE A FEW ITEMS TO DISCUSS. ALTHOUGH ANY REMAINING MVFR VISIBILITY RESTRICTIONS WILL BE SHORT-LIVED...AN INCREASE IN MOISTURE FROM THE SOUTH WILL RESULT IN SCATTERED TO BROKEN CLOUDS OVER THE REGION...GENERALLY IN THE 3500-6000 FOOT RANGE. SOUTHERLY FLOW WILL SWITCH TO THE SOUTHWEST...WITH GUSTS IN THE 18-22 KNOT RANGE BY EARLY AFTERNOON. A COLD FRONT IS FORECAST TO APPROACH THE REGION FROM THE NORTHWEST TONIGHT AND INTO SUNDAY MORNING. AHEAD OF THIS FRONT...PRECIPITATION IS FORECAST TO MOVE INTO THE AREA LATE THIS EVENING AND INTO THE EARLY MORNING HOURS. HOWEVER...THE EXTENT OF PRECIPITATION WITH THIS FRONT IS NOT CERTAIN. THE PRECIPITATION (WHICH COULD INCLUDE THUNDERSTORMS) SHOULD BE ON A WEAKENING TREND AS IT MOVES THROUGH THE TAF SITES. A TEMPO -SHRA GROUP WAS INCLUDED AT KDAY...BUT THE OTHER TAF SITES ARE NOT AS CERTAIN TO RECEIVE RAIN. AS THE FRONT NEARS...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR RANGE. OUTLOOK...A FEW SHOWERS...AND POSSIBLY A THUNDERSTORM...WILL BE POSSIBLE DURING THE FIRST HALF OF SUNDAY. MVFR CEILINGS ARE ALSO POSSIBLE ON SUNDAY MORNING. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HICKMAN NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...NOVAK AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
417 AM EDT SAT SEP 20 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF TO THE EAST TODAY AS A COLD FRONT APPROACHES FROM THE NORTHWEST. THE COLD FRONT WILL MOVE ACROSS THE AREA LATE TONIGHT AND SUNDAY. HIGH PRESSURE WILL THEN BECOME REESTABLISHED FOR MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NEAR TERM MODELS...SUCH AS THE HRRR AND RAP...CONTINUE TO FORECAST THE DEVELOPMENT OF LOWER LEVEL CLOUDS...4 K FT TO 6 KT ACROSS THE SRN CWFA TOWARD MORNING. THIS DEVELOPMENT IS DUE TO WEAK ISENTROPIC LIFT OCCURRING AROUND DEPARTING HIGH PRESSURE. THERE MAY BE ENOUGH SHALLOW INSTABILITY IN THIS DECK TO WARRANT A LOW CHANCE POP ALONG AND SOUTH OF THE OHIO RIVER THROUGH THE MORNING HOURS. OTHERWISE...WE SHOULD SEE PARTLY TO MOSTLY SUNNY SKIES TODAY OUT AHEAD OF A COLD FRONT WHICH WILL MAKE IN ROADS TOWARD OUR REGION TONIGHT. INCREASING SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND THE FRONT WILL BOOST TEMPERATURES INTO THE UPPER 70S TO THE LOWER 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... HAVE AGAIN USED A BLEND OF THE ECMWF/GFS...ALONG WITH CONVECTION ALLOWING MODELS...TO HONE IN ON THE PROSPECTS OF PCPN TONIGHT INTO SUNDAY NIGHT. A SERIES OF S/WVS WILL DIG EAST/SOUTHEAST THROUGH THE GREAT LAKES TONIGHT INTO SUNDAY NIGHT...WHICH WILL EVENTUALLY ESTABLISH A LONG WAVE MID LEVEL TROUGH OVER ERN CANADA SOUTHWARD INTO THE ERN U.S. BY MONDAY MORNING. THE FIRST WAVE...ALONG WITH PREFRONTAL CONVERGENCE...IS EXPECTED TO RESULT IN SHOWERS/THUNDERSTORMS TO OUR NORTHWEST LATE THIS AFTERNOON INTO EARLY THIS EVENING. MODELS CONTINUE TO SUGGEST THAT AS THIS ACTIVITY PROPAGATES SOUTHEAST INTO OUR AREA TONIGHT OUT AHEAD OF A COLD FRONT...IT WILL UNDERGO A WEAKENING TREND. RAPIDLY DECREASING INSTABILITY...WEAKENING LOW LEVEL FORCING...ALONG WITH WEAKENING UPPER LEVEL SUPPORT ARE THE REASONS THAT THIS IS FORECAST TO OCCUR. AS A RESULT...HAVE PLACED THE HIGHEST POPS TONIGHT OVER THE FAR NW...DECREASING THE THREAT TO JUST 30 AND 40 PERCENT THROUGH THE REMAINDER OF THE REGION TOWARD SUNDAY MORNING. ON SUNDAY...ANOTHER EMBEDDED S/WV WILL APPROACH FROM THE NORTHWEST WHILE THE COLD FRONT PUSHES EAST/SOUTHEAST THROUGH THE REGION. WITH THE FASTER TIMING OF THE GFS/ECMWF...BELIEVE ANY SHOWER/THUNDERSTORM REDEVELOPMENT SHOULD OCCUR JUST EAST/SOUTHEAST OF THE AREA. IN THE WAKE OF THE FRONT...AND BEFORE THE ARRIVAL OF THE NEXT S/WV...WE SHOULD SEE A POCKET OF DRY WEATHER ALONG WITH PARTLY TO MOSTLY SUNNY SKIES. HIGHS ON SUNDAY WILL BE TRICKY AS CAA WILL BE ONGOING THROUGH THE DAY. WILL FORECAST LOWER 70S NORTHWEST TO THE UPPER 70S SOUTHERN/SOUTHEAST. FOR SUNDAY NIGHT...AFOREMENTIONED S/WV WILL PASS THROUGH THE REGION ALONG WITH A SFC TROF AXIS. THERE COULD BE ENOUGH INSTABILITY WITH THIS FEATURE TO BRING A FEW SPOTTY SHOWERS TO THE NRN ZONES SUNDAY EVENING. BUT AS TIME WEARS ON AND INSTABILITY WANES...THE THREAT SHOULD RELEGATE ITSELF TO OUR NE TOWARD CENTRAL/EASTERN LAKE ERIE. PARTLY CLOUD SKIES WILL UNDERGO A CLEARING TREND...ESPECIALLY WEST OVERNIGHT. LOWS WILL DROP INTO THE MID 40S NORTHWEST TO THE LOWER 50S SOUTHEAST. FOR MONDAY INTO MONDAY NIGHT...MID LEVEL TROUGH WILL MOVE EAST AS A MID LEVEL RIDGE BUILDS NORTHWARD INTO THE MIDDLE AND UPPER MS RIVER VALLEY. AT THE SURFACE...A SPRAWLING AREA OF HIGH PRESSURE WILL BE FOUND AS IT SETTLES RIGHT OVER THE OHIO VALLEY BY TUESDAY MORNING. CLOUDS WILL CONTINUE TO DECREASE THROUGH THE PERIOD WITH CLEAR SKIES EXPECTED BY MONDAY NIGHT. AFTER COOL TEMPERATURES RANGING FROM THE LOWER 60S NORTH TO THE UPPER 60S SOUTH...OVERNIGHT LOWS WILL DIP INTO THE UPPER 30S AND LOWER 40S BY TUESDAY MORNING. ON TUESDAY...WITH THE HIGH REMAINING IN PLACE...SKIES WILL BE SUNNY. HIGHS WILL WARM INTO THE UPPER 60S TO THE LOWER 70S. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH THE LONG TERM. TEMPERATURES WILL SLOWLY WARM THROUGH THE LONG TERM WITH HIGH TEMPERATURES BY FRIDAY EXPECTED TO BE IN THE MID TO UPPER 70S. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS ARE GENERALLY EXPECTED...BUT WITH A FEW COMPLICATIONS IN THE FORECAST TO DISCUSS. TRANQUIL CONDITIONS TO BEGIN THE OVERNIGHT PERIOD WILL GIVE WAY TO INCREASING SOUTHERLY FLOW BY MORNING...TURNING SOUTHWESTERLY AND GUSTY (UP TO 20 KNOTS) BY EARLY AFTERNOON. AN INCREASE IN CLOUDS IS EXPECTED GOING INTO THE DAY...GENERALLY IN THE 4000-6000 FOOT RANGE. MVFR FOG AT KLUK WILL LIKELY DISSIPATE OVER THE NEXT FEW HOURS...AS WINDS BEGIN TO INCREASE. A COLD FRONT WILL APPROACH THE REGION ON SATURDAY NIGHT AND INTO EARLY SUNDAY MORNING. THE EXTENT OF PRECIPITATION WITH THIS FRONT IS NOT CERTAIN...BUT IT LOOKS LIKE THE TIMING WILL BRING A CHANCE OF PRE-FRONTAL PRECIPITATION TO THE TAF SITES BY 05Z-08Z. OUTLOOK...THUNDERSTORMS ARE POSSIBLE FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HICKMAN NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...NOVAK AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1145 AM CDT SAT SEP 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 250 AM CDT SAT SEP 20 2014 MAIN CONCERNS ARE ON EXITING MORNING CONVECTION AND THE RETURN FOR MORE CONVECTION TONIGHT. CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED AN UPPER LOW JUST OFF THE CALIFORNIA COAST...RIDGING OVER THE WESTERN THIRD OF THE U.S. INTO BRITISH COLUMBIA...AND TROUGHING OVER CENTRAL CANADA INTO THE NORTHERN PLAINS/UPPER MIDWEST. A COUPLE OF SHORTWAVES TRAVERSING THROUGH THIS TROUGH IN SOUTH DAKOTA AND MN... COMBINED WITH A SURFACE TO 850MB COLD FRONT THAT STRETCHED FROM DULUTH TO SIOUX CITY IA...HAVE AIDED IN MAINTAINING A BAND OF SHOWERS AND THUNDERSTORMS. THIS BAND EXTENDS FROM WEST CENTRAL IA THROUGH THE FORECAST AREA. MUCH OF THE ACTIVITY HAS BEEN ELEVATED IN NATURE DUE TO CAPPING PRESENT OF BL PARCELS. PLENTY OF INSTABILITY FOR THE CONVECTION WITH CAPE VALUES LIFTED FROM 1 KM BETWEEN 1000- 2000 J/KG. IN THE WAKE OF THE CONVECTION...THERE HAS BEEN A NARROW AREA OF LOW STRATUS DEVELOPING...BEFORE CLOUDS CLEAR OUT OVER CENTRAL MN. AIRMASS BEHIND THE COLD FRONT WAS NOT MUCH COLDER THAN AHEAD...WITH 925MB TEMPS HOVERING BETWEEN 20-24C. HOWEVER... PRECIPITABLE WATER DROPS SIGNIFICANTLY FROM 1.5-1.75 INCHES TO 1- 1.25 INCHES. UPSTREAM A MORE SIGNIFICANT COLD FRONT EXISTS OVER NORTHERN NORTH DAKOTA AND NORTHWEST MN WHERE 925MB TEMPS DROP TO 12- 14C. THE COLLECTION OF SHORTWAVES ACROSS SOUTH DAKOTA AND MN ARE PROGGED TO CROSS THE FORECAST AREA THIS MORNING...PUSHING THE SURFACE-850MB COLD FRONT THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z. ANTICIPATING MUCH OF THE CURRENT CONVECTION AHEAD OF THESE FEATURES TO MARCH SOUTHEASTWARD OUT OF THE FORECAST AREA BY 13Z PER HIGH RESOLUTION MODEL CONSENSUS. STILL CARRIED SOME LOW PRECIPITATION CHANCES OVER THE SOUTHEAST HALF IN THE WAKE OF THE CURRENT ACTIVITY IN THE EVENT ADDITIONAL SHOWERS/STORMS FORM AS THE SHORTWAVES MOVE IN. OTHERWISE...SUBSIDENCE AND DRYING OF PRECIPITABLE WATER SHOULD ALLOW SKIES TO CLEAR AFTER A BRIEF PERIOD OF MORNING STRATUS. THE SUNSHINE COMBINED WITH 925MB TEMPS OF 18-20C FOR MUCH OF TODAY SHOULD ALLOW FOR HIGHS TO TOP OUT IN THE 70S IN MOST LOCATIONS...WITH SOME LOW 80S IN VALLEYS. SHORTLY AFTER 00Z THIS EVENING...ANOTHER LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS LOOKS LIKELY TO MOVE ACROSS THE REGION... ESPECIALLY ALONG AND NORTH OF I-90. THIS LINE OF CONVECTION WILL BE FORCED BY A POTENT SHORTWAVE OVER CENTRAL ALBERTA DROPPING THROUGH THE UPPER MIDWEST TROUGHING. THE SHORTWAVE SHOULD ALSO HAVE A NARROW CORRIDOR OF MOISTURE TO WORK WITH AS PRECIPITABLE WATER JUMPS UP TO 1-1.3 INCHES. INSTABILITY WISE...ITS FAIRLY MEAGER WITH VALUES OF 100-500 J/KG...MOSTLY IN THE EVENING DUE TO LOSS OF DAYTIME HEATING COOLING THE BOUNDARY LAYER. ANTICIPATING MORE THUNDERSTORM ACTIVITY SHOULD OCCUR TODAY UPSTREAM OVER NORTH DAKOTA INTO CENTRAL MN WHERE THE JUXTAPOSITION OF HIGHER DIURNALLY BASED INSTABILITY INTERSECTS THE SHORTWAVE. SHEAR PROFILES WOULD CERTAINLY SUPPORT BOTH A DAMAGING WIND AND LARGE HAIL THREAT WITH CONVECTION...HOWEVER...THE MEAGER INSTABILITY BY THE TIME THE CONVECTION MOVES INTO THE FORECAST AREA SHOULD HELP MITIGATE SEVERE POTENTIAL. MAY STILL SEE SOME STRONGER WIND GUSTS...THOUGH. HAVE RAISED PRECIPITATION CHANCES UP FOR THE EVENING HOURS GIVEN VERY GOOD MODEL CONSENSUS FOR THIS CONVECTION. KEPT SOME PRECIPITATION CHANCES GOING OVERNIGHT TOO ALONG AND NORTH OF I-94 WHERE A FRONTOGENESIS BAND LOOKS TO SETUP ON THE NORTH SIDE OF THE SHORTWAVE. LOOK FOR COOLER TEMPERATURES TONIGHT AS COLDER AIR RUSHES IN BEHIND THE LINE OF CONVECTION. IN FACT...925MB TEMPS COOL AS MUCH AS 10C ON A BRISK 30-40 KT 925MB NORTHWEST WIND. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 250 AM CDT SAT SEP 20 2014 MAIN CONCERNS ARE ON PRECIPITATION POTENTIAL FOR SUNDAY...FOLLOWED BY TEMPERATURES AND VALLEY FOG POTENTIAL SUNDAY NIGHT AND BEYOND. ANOTHER POTENT SHORTWAVE LOOKS TO FOLLOW QUICKLY ON THE HEELS OF THE ONE MOVING THROUGH THE FORECAST AREA TONIGHT. THIS SHORTWAVE... CURRENTLY IN NORTHERN SASKATCHEWAN...IS PROGGED TO DROP SOUTH THROUGH THE FORECAST AREA SUNDAY MORNING. THIS SHORTWAVE WILL HELP TO PULL THE FRONTOGENESIS BAND AND ASSOCIATED SURFACE COLD FRONT SOUTHWARD THROUGH THE FORECAST AREA DURING THE MORNING HOURS. APPEARS THE BULK OF THE RAIN/SHOWER ACTIVITY WITH THE BAND WILL BE CONFINED TO WISCONSIN...BUT SOME MAY EVEN CREEP ACROSS THE MS RIVER AS SUGGESTED BY THE 20.00Z ECMWF/CANADIAN. HAVE RAISED PRECIPITATION CHANCES UPWARDS AND FURTHER INCREASES MAY BE NECESSARY. OVERALL AMOUNTS LOOK TO BE FAIRLY LIGHT...THOUGH. THIS FRONTAL BOUNDARY DROPPING SOUTH...925MB TEMPS ONLY TOPPING OUT FROM 10-12C AT 00Z MONDAY...A BREEZY NORTH WIND AND A DECENT AMOUNT OF SUN NOT OCCURRING UNTIL LATE IN THE DAY WILL YIELD MUCH COOLER CONDITIONS COMPARED TO TODAY. MODELS REMAIN IN GOOD AGREEMENT IN BUILDING HIGH PRESSURE INTO THE FORECAST AREA FOR SUNDAY NIGHT THROUGH TUESDAY. THIS IS IN RESPONSE TO THE UPPER RIDGE OVER THE WESTERN THIRD OF THE U.S. MARCHING EAST INTO MN AND IA BY 12Z TUE. THE MAIN CENTER OF THE HIGH LOOKS TO TRACK JUST SOUTH OF THE AREA...BUT THE GRADIENT RELAXES ENOUGH TO ALLOW FOR DECOUPLING BOTH NIGHTS. SOME CLOUDS COULD DRIFT ACROSS BOTH NIGHTS...BUT IT APPEARS ENOUGH PERIOD OF CLEAR SKIES SHOULD EXIST FOR VALLEY FOG TO FORM...ESPECIALLY IN THE TRIBUTARIES. SUNDAY NIGHT WILL BE THE COOLER OF THE TWO NIGHTS DUE TO AIRMASS MODIFICATION TAKING PLACE ON MONDAY. THE TYPICAL COLD SPOTS IN CENTRAL WI COULD DIP INTO THE MID/UPPER 30S SUNDAY NIGHT. 925MB TEMPS OF 12-14C ON MONDAY WITH MORE SUN WILL ALLOW HIGHS TO TOP OUT IN THE 60S TO LOW 70S...WARMEST IN VALLEYS. THESE 925MB TEMPS CLIMB ANOTHER 1-2C ON TUESDAY...RESULTING IN A SIMILAR BUMP UP IN HIGHS. IN GENERAL THE WEATHER REMAINS FAIRLY QUIET FROM TUESDAY NIGHT RIGHT INTO NEXT WEEKEND...THANKS TO SIGNIFICANT UPPER RIDGING BUILDING UP OVER THE EASTERN TWO THIRDS OF THE U.S.. IN FACT...MOST LONG RANGE GUIDANCE IS SUGGESTING A 590 DAM 500MB HIGH TO FORM OVER MICHIGAN BY 00Z SATURDAY...WHICH WOULD BE ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL. THIS IS ALL A RESULT OF A VERY DEEP TROUGH DEVELOPING ALONG THE WEST COAST OF THE U.S....SOMETHING THAT HASNT BEEN SEEN FOR QUITE SOME TIME. THE ONLY REAL ISSUE TO WORRY ABOUT IS THE CURRENT UPPER LOW OFF THE CALIFORNIA COAST...WHICH MODELS TRY TO BRING THROUGH THE FORECAST AREA IN A WEAKENING STATE CENTERED AROUND WEDNESDAY. HAVE MAINTAINED SOME LOW PRECIPITATION CHANCES ASSOCIATED WITH THIS FEATURE. DESPITE THE RISING 500MB HEIGHTS...IT TAKES AWHILE FOR A SIMILAR RESPONSE TO 850MB TEMPS...PARTIALLY DUE TO THAT UPPER LOW LIFTING THROUGH. THUS...TEMPERATURES HOLD NEAR SEASONABLE NORMALS UNTIL THE END OF THE WEEK. FRIDAY...SATURDAY AND SUNDAY ALL LOOK ABOVE NORMAL WITH HIGHS POSSIBLY APPROACHING 80. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1145 AM CDT SAT SEP 20 2014 SFC FRONT SLIDING ACROSS THE REGION...WITH SATELLITE IMAGERY POINTING TO SKC SKIES POST FRONT. EXPECTING VFR CONDITIONS THROUGH THE AFTERNOON INTO THE EARLY EVENING. AN UPPER LEVEL SHORTWAVE TROUGH WILL DRIVE SOUTHEAST ACROSS THE NORTHERN PLAINS AND THEN THROUGH THE UPPER MISSISSIPPI RIVER VALLEY TONIGHT. A COLD FRONT AT THE SFC WILL ACCOMPANY THE SHORTWAVE...AND HELP FIRE A LINE OF SHOWERS/ISOLATED THUNDERSTORMS AS IT MOVES THROUGH. COULD SEE SOME HIGHER GUSTS AROUND THE STRONGER STORMS - WITH AN ISOLATED SEVERE THREAT EARLY IN THE EVENING. UPSTREAM OBS WITH THE SHORTWAVE POINT TO AN AREA OF MVFR CIGS IN THE 2-2.5 KFT RANGE. MODEL RH FIELDS AND BUFKIT SOUNDINGS FAVOR THIS TOO...ESPECIALLY ALONG AND EAST OF THE MISSISSIPPI RIVER. MOST OF THIS APPEARS POST THE APPROX 3 HOUR WINDOW WHEN A -SHRA/TS THREAT IS HIGHLIGHTED. SPEAKING OF WHICH...WITH INSTABILITY MINIMAL AT BEST...WILL KEEP MENTION TO -SHRA RATHER THAN -TSRA. DYNAMICS DO APPEAR STRONG ENOUGH FOR SOME ISOLD THUNDER...BUT NOT CONFIDENT ENOUGH TO INCLUDE IN TAFS AT THIS TIME. FRONT LIKELY LINGERS ACROSS THE REGION FOR THE BETTER PART OF SUNDAY...BEFORE HIGH PRESSURE AND SUBSIDENCE WORKS IN BY THE EVENING. KLSE COULD BE UNDER MVFR CLOUDS FOR THE BETTER PART OF THE MORNING...POTENTIALLY LINGERING THROUGH THE AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
659 AM CDT SAT SEP 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 250 AM CDT SAT SEP 20 2014 MAIN CONCERNS ARE ON EXITING MORNING CONVECTION AND THE RETURN FOR MORE CONVECTION TONIGHT. CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED AN UPPER LOW JUST OFF THE CALIFORNIA COAST...RIDGING OVER THE WESTERN THIRD OF THE U.S. INTO BRITISH COLUMBIA...AND TROUGHING OVER CENTRAL CANADA INTO THE NORTHERN PLAINS/UPPER MIDWEST. A COUPLE OF SHORTWAVES TRAVERSING THROUGH THIS TROUGH IN SOUTH DAKOTA AND MN... COMBINED WITH A SURFACE TO 850MB COLD FRONT THAT STRETCHED FROM DULUTH TO SIOUX CITY IA...HAVE AIDED IN MAINTAINING A BAND OF SHOWERS AND THUNDERSTORMS. THIS BAND EXTENDS FROM WEST CENTRAL IA THROUGH THE FORECAST AREA. MUCH OF THE ACTIVITY HAS BEEN ELEVATED IN NATURE DUE TO CAPPING PRESENT OF BL PARCELS. PLENTY OF INSTABILITY FOR THE CONVECTION WITH CAPE VALUES LIFTED FROM 1 KM BETWEEN 1000- 2000 J/KG. IN THE WAKE OF THE CONVECTION...THERE HAS BEEN A NARROW AREA OF LOW STRATUS DEVELOPING...BEFORE CLOUDS CLEAR OUT OVER CENTRAL MN. AIRMASS BEHIND THE COLD FRONT WAS NOT MUCH COLDER THAN AHEAD...WITH 925MB TEMPS HOVERING BETWEEN 20-24C. HOWEVER... PRECIPITABLE WATER DROPS SIGNIFICANTLY FROM 1.5-1.75 INCHES TO 1- 1.25 INCHES. UPSTREAM A MORE SIGNIFICANT COLD FRONT EXISTS OVER NORTHERN NORTH DAKOTA AND NORTHWEST MN WHERE 925MB TEMPS DROP TO 12- 14C. THE COLLECTION OF SHORTWAVES ACROSS SOUTH DAKOTA AND MN ARE PROGGED TO CROSS THE FORECAST AREA THIS MORNING...PUSHING THE SURFACE-850MB COLD FRONT THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z. ANTICIPATING MUCH OF THE CURRENT CONVECTION AHEAD OF THESE FEATURES TO MARCH SOUTHEASTWARD OUT OF THE FORECAST AREA BY 13Z PER HIGH RESOLUTION MODEL CONSENSUS. STILL CARRIED SOME LOW PRECIPITATION CHANCES OVER THE SOUTHEAST HALF IN THE WAKE OF THE CURRENT ACTIVITY IN THE EVENT ADDITIONAL SHOWERS/STORMS FORM AS THE SHORTWAVES MOVE IN. OTHERWISE...SUBSIDENCE AND DRYING OF PRECIPITABLE WATER SHOULD ALLOW SKIES TO CLEAR AFTER A BRIEF PERIOD OF MORNING STRATUS. THE SUNSHINE COMBINED WITH 925MB TEMPS OF 18-20C FOR MUCH OF TODAY SHOULD ALLOW FOR HIGHS TO TOP OUT IN THE 70S IN MOST LOCATIONS...WITH SOME LOW 80S IN VALLEYS. SHORTLY AFTER 00Z THIS EVENING...ANOTHER LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS LOOKS LIKELY TO MOVE ACROSS THE REGION... ESPECIALLY ALONG AND NORTH OF I-90. THIS LINE OF CONVECTION WILL BE FORCED BY A POTENT SHORTWAVE OVER CENTRAL ALBERTA DROPPING THROUGH THE UPPER MIDWEST TROUGHING. THE SHORTWAVE SHOULD ALSO HAVE A NARROW CORRIDOR OF MOISTURE TO WORK WITH AS PRECIPITABLE WATER JUMPS UP TO 1-1.3 INCHES. INSTABILITY WISE...ITS FAIRLY MEAGER WITH VALUES OF 100-500 J/KG...MOSTLY IN THE EVENING DUE TO LOSS OF DAYTIME HEATING COOLING THE BOUNDARY LAYER. ANTICIPATING MORE THUNDERSTORM ACTIVITY SHOULD OCCUR TODAY UPSTREAM OVER NORTH DAKOTA INTO CENTRAL MN WHERE THE JUXTAPOSITION OF HIGHER DIURNALLY BASED INSTABILITY INTERSECTS THE SHORTWAVE. SHEAR PROFILES WOULD CERTAINLY SUPPORT BOTH A DAMAGING WIND AND LARGE HAIL THREAT WITH CONVECTION...HOWEVER...THE MEAGER INSTABILITY BY THE TIME THE CONVECTION MOVES INTO THE FORECAST AREA SHOULD HELP MITIGATE SEVERE POTENTIAL. MAY STILL SEE SOME STRONGER WIND GUSTS...THOUGH. HAVE RAISED PRECIPITATION CHANCES UP FOR THE EVENING HOURS GIVEN VERY GOOD MODEL CONSENSUS FOR THIS CONVECTION. KEPT SOME PRECIPITATION CHANCES GOING OVERNIGHT TOO ALONG AND NORTH OF I-94 WHERE A FRONTOGENESIS BAND LOOKS TO SETUP ON THE NORTH SIDE OF THE SHORTWAVE. LOOK FOR COOLER TEMPERATURES TONIGHT AS COLDER AIR RUSHES IN BEHIND THE LINE OF CONVECTION. IN FACT...925MB TEMPS COOL AS MUCH AS 10C ON A BRISK 30-40 KT 925MB NORTHWEST WIND. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 250 AM CDT SAT SEP 20 2014 MAIN CONCERNS ARE ON PRECIPITATION POTENTIAL FOR SUNDAY...FOLLOWED BY TEMPERATURES AND VALLEY FOG POTENTIAL SUNDAY NIGHT AND BEYOND. ANOTHER POTENT SHORTWAVE LOOKS TO FOLLOW QUICKLY ON THE HEELS OF THE ONE MOVING THROUGH THE FORECAST AREA TONIGHT. THIS SHORTWAVE... CURRENTLY IN NORTHERN SASKATCHEWAN...IS PROGGED TO DROP SOUTH THROUGH THE FORECAST AREA SUNDAY MORNING. THIS SHORTWAVE WILL HELP TO PULL THE FRONTOGENESIS BAND AND ASSOCIATED SURFACE COLD FRONT SOUTHWARD THROUGH THE FORECAST AREA DURING THE MORNING HOURS. APPEARS THE BULK OF THE RAIN/SHOWER ACTIVITY WITH THE BAND WILL BE CONFINED TO WISCONSIN...BUT SOME MAY EVEN CREEP ACROSS THE MS RIVER AS SUGGESTED BY THE 20.00Z ECMWF/CANADIAN. HAVE RAISED PRECIPITATION CHANCES UPWARDS AND FURTHER INCREASES MAY BE NECESSARY. OVERALL AMOUNTS LOOK TO BE FAIRLY LIGHT...THOUGH. THIS FRONTAL BOUNDARY DROPPING SOUTH...925MB TEMPS ONLY TOPPING OUT FROM 10-12C AT 00Z MONDAY...A BREEZY NORTH WIND AND A DECENT AMOUNT OF SUN NOT OCCURRING UNTIL LATE IN THE DAY WILL YIELD MUCH COOLER CONDITIONS COMPARED TO TODAY. MODELS REMAIN IN GOOD AGREEMENT IN BUILDING HIGH PRESSURE INTO THE FORECAST AREA FOR SUNDAY NIGHT THROUGH TUESDAY. THIS IS IN RESPONSE TO THE UPPER RIDGE OVER THE WESTERN THIRD OF THE U.S. MARCHING EAST INTO MN AND IA BY 12Z TUE. THE MAIN CENTER OF THE HIGH LOOKS TO TRACK JUST SOUTH OF THE AREA...BUT THE GRADIENT RELAXES ENOUGH TO ALLOW FOR DECOUPLING BOTH NIGHTS. SOME CLOUDS COULD DRIFT ACROSS BOTH NIGHTS...BUT IT APPEARS ENOUGH PERIOD OF CLEAR SKIES SHOULD EXIST FOR VALLEY FOG TO FORM...ESPECIALLY IN THE TRIBUTARIES. SUNDAY NIGHT WILL BE THE COOLER OF THE TWO NIGHTS DUE TO AIRMASS MODIFICATION TAKING PLACE ON MONDAY. THE TYPICAL COLD SPOTS IN CENTRAL WI COULD DIP INTO THE MID/UPPER 30S SUNDAY NIGHT. 925MB TEMPS OF 12-14C ON MONDAY WITH MORE SUN WILL ALLOW HIGHS TO TOP OUT IN THE 60S TO LOW 70S...WARMEST IN VALLEYS. THESE 925MB TEMPS CLIMB ANOTHER 1-2C ON TUESDAY...RESULTING IN A SIMILAR BUMP UP IN HIGHS. IN GENERAL THE WEATHER REMAINS FAIRLY QUIET FROM TUESDAY NIGHT RIGHT INTO NEXT WEEKEND...THANKS TO SIGNIFICANT UPPER RIDGING BUILDING UP OVER THE EASTERN TWO THIRDS OF THE U.S.. IN FACT...MOST LONG RANGE GUIDANCE IS SUGGESTING A 590 DAM 500MB HIGH TO FORM OVER MICHIGAN BY 00Z SATURDAY...WHICH WOULD BE ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL. THIS IS ALL A RESULT OF A VERY DEEP TROUGH DEVELOPING ALONG THE WEST COAST OF THE U.S....SOMETHING THAT HASNT BEEN SEEN FOR QUITE SOME TIME. THE ONLY REAL ISSUE TO WORRY ABOUT IS THE CURRENT UPPER LOW OFF THE CALIFORNIA COAST...WHICH MODELS TRY TO BRING THROUGH THE FORECAST AREA IN A WEAKENING STATE CENTERED AROUND WEDNESDAY. HAVE MAINTAINED SOME LOW PRECIPITATION CHANCES ASSOCIATED WITH THIS FEATURE. DESPITE THE RISING 500MB HEIGHTS...IT TAKES AWHILE FOR A SIMILAR RESPONSE TO 850MB TEMPS...PARTIALLY DUE TO THAT UPPER LOW LIFTING THROUGH. THUS...TEMPERATURES HOLD NEAR SEASONABLE NORMALS UNTIL THE END OF THE WEEK. FRIDAY...SATURDAY AND SUNDAY ALL LOOK ABOVE NORMAL WITH HIGHS POSSIBLY APPROACHING 80. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 658 AM CDT SAT SEP 20 2014 SCATTERED SHOWERS AHEAD OF A COLD FRONT WILL AFFECT KRST THROUGH 20.16Z. THE MESO MODELS SUGGEST THAT THESE SHOWERS WILL NOT MAKE IT INTO KLSE. HOWEVER WITH WEAK 700 MB MOISTURE TRANSPORT INTO THE AREA BETWEEN 20.15Z AND 20.18Z...MAY HAVE TO RECONSIDER ADDING THEM TO THE TAF LATER THIS MORNING. AFTER THE PASSAGE OF THIS FRONT...IT WILL REMAIN DRY WITH VFR CEILINGS AND VISIBILITIES THROUGH THIS AFTERNOON. ANOTHER COLD FRONT WILL MOVE THROUGH THE TAF SITES THIS EVENING. IT WILL MOVE THROUGH KRST BETWEEN 21.01Z AND 21.03Z...AND KLSE BETWEEN 21.02Z AND 21.04Z. CEILINGS WILL DROP TO 5K FEET DURING THIS TIME PERIOD. VISIBILITIES MAY BECOME BRIEFLY MVFR IN SHOWERS. FOR LATE TONIGHT...THE MODEL SUGGEST THAT A MVFR STRATUS DECK MAY DEVELOP. HOWEVER WITH DRY AIR LOCATED ACROSS REGION...A BIT CONCERNED THAT THE MODELS MAY BE OVER DOING THIS...SO OPTED NOT PUTTING THESE CLOUDS IN THE TAFS AT THIS TIME. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
250 AM CDT SAT SEP 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 250 AM CDT SAT SEP 20 2014 MAIN CONCERNS ARE ON EXITING MORNING CONVECTION AND THE RETURN FOR MORE CONVECTION TONIGHT. CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED AN UPPER LOW JUST OFF THE CALIFORNIA COAST...RIDGING OVER THE WESTERN THIRD OF THE U.S. INTO BRITISH COLUMBIA...AND TROUGHING OVER CENTRAL CANADA INTO THE NORTHERN PLAINS/UPPER MIDWEST. A COUPLE OF SHORTWAVES TRAVERSING THROUGH THIS TROUGH IN SOUTH DAKOTA AND MN... COMBINED WITH A SURFACE TO 850MB COLD FRONT THAT STRETCHED FROM DULUTH TO SIOUX CITY IA...HAVE AIDED IN MAINTAINING A BAND OF SHOWERS AND THUNDERSTORMS. THIS BAND EXTENDS FROM WEST CENTRAL IA THROUGH THE FORECAST AREA. MUCH OF THE ACTIVITY HAS BEEN ELEVATED IN NATURE DUE TO CAPPING PRESENT OF BL PARCELS. PLENTY OF INSTABILITY FOR THE CONVECTION WITH CAPE VALUES LIFTED FROM 1 KM BETWEEN 1000- 2000 J/KG. IN THE WAKE OF THE CONVECTION...THERE HAS BEEN A NARROW AREA OF LOW STRATUS DEVELOPING...BEFORE CLOUDS CLEAR OUT OVER CENTRAL MN. AIRMASS BEHIND THE COLD FRONT WAS NOT MUCH COLDER THAN AHEAD...WITH 925MB TEMPS HOVERING BETWEEN 20-24C. HOWEVER... PRECIPITABLE WATER DROPS SIGNIFICANTLY FROM 1.5-1.75 INCHES TO 1- 1.25 INCHES. UPSTREAM A MORE SIGNIFICANT COLD FRONT EXISTS OVER NORTHERN NORTH DAKOTA AND NORTHWEST MN WHERE 925MB TEMPS DROP TO 12- 14C. THE COLLECTION OF SHORTWAVES ACROSS SOUTH DAKOTA AND MN ARE PROGGED TO CROSS THE FORECAST AREA THIS MORNING...PUSHING THE SURFACE-850MB COLD FRONT THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z. ANTICIPATING MUCH OF THE CURRENT CONVECTION AHEAD OF THESE FEATURES TO MARCH SOUTHEASTWARD OUT OF THE FORECAST AREA BY 13Z PER HIGH RESOLUTION MODEL CONSENSUS. STILL CARRIED SOME LOW PRECIPITATION CHANCES OVER THE SOUTHEAST HALF IN THE WAKE OF THE CURRENT ACTIVITY IN THE EVENT ADDITIONAL SHOWERS/STORMS FORM AS THE SHORTWAVES MOVE IN. OTHERWISE...SUBSIDENCE AND DRYING OF PRECIPITABLE WATER SHOULD ALLOW SKIES TO CLEAR AFTER A BRIEF PERIOD OF MORNING STRATUS. THE SUNSHINE COMBINED WITH 925MB TEMPS OF 18-20C FOR MUCH OF TODAY SHOULD ALLOW FOR HIGHS TO TOP OUT IN THE 70S IN MOST LOCATIONS...WITH SOME LOW 80S IN VALLEYS. SHORTLY AFTER 00Z THIS EVENING...ANOTHER LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS LOOKS LIKELY TO MOVE ACROSS THE REGION... ESPECIALLY ALONG AND NORTH OF I-90. THIS LINE OF CONVECTION WILL BE FORCED BY A POTENT SHORTWAVE OVER CENTRAL ALBERTA DROPPING THROUGH THE UPPER MIDWEST TROUGHING. THE SHORTWAVE SHOULD ALSO HAVE A NARROW CORRIDOR OF MOISTURE TO WORK WITH AS PRECIPITABLE WATER JUMPS UP TO 1-1.3 INCHES. INSTABILITY WISE...ITS FAIRLY MEAGER WITH VALUES OF 100-500 J/KG...MOSTLY IN THE EVENING DUE TO LOSS OF DAYTIME HEATING COOLING THE BOUNDARY LAYER. ANTICIPATING MORE THUNDERSTORM ACTIVITY SHOULD OCCUR TODAY UPSTREAM OVER NORTH DAKOTA INTO CENTRAL MN WHERE THE JUXTAPOSITION OF HIGHER DIURNALLY BASED INSTABILITY INTERSECTS THE SHORTWAVE. SHEAR PROFILES WOULD CERTAINLY SUPPORT BOTH A DAMAGING WIND AND LARGE HAIL THREAT WITH CONVECTION...HOWEVER...THE MEAGER INSTABILITY BY THE TIME THE CONVECTION MOVES INTO THE FORECAST AREA SHOULD HELP MITIGATE SEVERE POTENTIAL. MAY STILL SEE SOME STRONGER WIND GUSTS...THOUGH. HAVE RAISED PRECIPITATION CHANCES UP FOR THE EVENING HOURS GIVEN VERY GOOD MODEL CONSENSUS FOR THIS CONVECTION. KEPT SOME PRECIPITATION CHANCES GOING OVERNIGHT TOO ALONG AND NORTH OF I-94 WHERE A FRONTOGENESIS BAND LOOKS TO SETUP ON THE NORTH SIDE OF THE SHORTWAVE. LOOK FOR COOLER TEMPERATURES TONIGHT AS COLDER AIR RUSHES IN BEHIND THE LINE OF CONVECTION. IN FACT...925MB TEMPS COOL AS MUCH AS 10C ON A BRISK 30-40 KT 925MB NORTHWEST WIND. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 250 AM CDT SAT SEP 20 2014 MAIN CONCERNS ARE ON PRECIPITATION POTENTIAL FOR SUNDAY...FOLLOWED BY TEMPERATURES AND VALLEY FOG POTENTIAL SUNDAY NIGHT AND BEYOND. ANOTHER POTENT SHORTWAVE LOOKS TO FOLLOW QUICKLY ON THE HEELS OF THE ONE MOVING THROUGH THE FORECAST AREA TONIGHT. THIS SHORTWAVE... CURRENTLY IN NORTHERN SASKATCHEWAN...IS PROGGED TO DROP SOUTH THROUGH THE FORECAST AREA SUNDAY MORNING. THIS SHORTWAVE WILL HELP TO PULL THE FRONTOGENESIS BAND AND ASSOCIATED SURFACE COLD FRONT SOUTHWARD THROUGH THE FORECAST AREA DURING THE MORNING HOURS. APPEARS THE BULK OF THE RAIN/SHOWER ACTIVITY WITH THE BAND WILL BE CONFINED TO WISCONSIN...BUT SOME MAY EVEN CREEP ACROSS THE MS RIVER AS SUGGESTED BY THE 20.00Z ECMWF/CANADIAN. HAVE RAISED PRECIPITATION CHANCES UPWARDS AND FURTHER INCREASES MAY BE NECESSARY. OVERALL AMOUNTS LOOK TO BE FAIRLY LIGHT...THOUGH. THIS FRONTAL BOUNDARY DROPPING SOUTH...925MB TEMPS ONLY TOPPING OUT FROM 10-12C AT 00Z MONDAY...A BREEZY NORTH WIND AND A DECENT AMOUNT OF SUN NOT OCCURRING UNTIL LATE IN THE DAY WILL YIELD MUCH COOLER CONDITIONS COMPARED TO TODAY. MODELS REMAIN IN GOOD AGREEMENT IN BUILDING HIGH PRESSURE INTO THE FORECAST AREA FOR SUNDAY NIGHT THROUGH TUESDAY. THIS IS IN RESPONSE TO THE UPPER RIDGE OVER THE WESTERN THIRD OF THE U.S. MARCHING EAST INTO MN AND IA BY 12Z TUE. THE MAIN CENTER OF THE HIGH LOOKS TO TRACK JUST SOUTH OF THE AREA...BUT THE GRADIENT RELAXES ENOUGH TO ALLOW FOR DECOUPLING BOTH NIGHTS. SOME CLOUDS COULD DRIFT ACROSS BOTH NIGHTS...BUT IT APPEARS ENOUGH PERIOD OF CLEAR SKIES SHOULD EXIST FOR VALLEY FOG TO FORM...ESPECIALLY IN THE TRIBUTARIES. SUNDAY NIGHT WILL BE THE COOLER OF THE TWO NIGHTS DUE TO AIRMASS MODIFICATION TAKING PLACE ON MONDAY. THE TYPICAL COLD SPOTS IN CENTRAL WI COULD DIP INTO THE MID/UPPER 30S SUNDAY NIGHT. 925MB TEMPS OF 12-14C ON MONDAY WITH MORE SUN WILL ALLOW HIGHS TO TOP OUT IN THE 60S TO LOW 70S...WARMEST IN VALLEYS. THESE 925MB TEMPS CLIMB ANOTHER 1-2C ON TUESDAY...RESULTING IN A SIMILAR BUMP UP IN HIGHS. IN GENERAL THE WEATHER REMAINS FAIRLY QUIET FROM TUESDAY NIGHT RIGHT INTO NEXT WEEKEND...THANKS TO SIGNIFICANT UPPER RIDGING BUILDING UP OVER THE EASTERN TWO THIRDS OF THE U.S.. IN FACT...MOST LONG RANGE GUIDANCE IS SUGGESTING A 590 DAM 500MB HIGH TO FORM OVER MICHIGAN BY 00Z SATURDAY...WHICH WOULD BE ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL. THIS IS ALL A RESULT OF A VERY DEEP TROUGH DEVELOPING ALONG THE WEST COAST OF THE U.S....SOMETHING THAT HASNT BEEN SEEN FOR QUITE SOME TIME. THE ONLY REAL ISSUE TO WORRY ABOUT IS THE CURRENT UPPER LOW OFF THE CALIFORNIA COAST...WHICH MODELS TRY TO BRING THROUGH THE FORECAST AREA IN A WEAKENING STATE CENTERED AROUND WEDNESDAY. HAVE MAINTAINED SOME LOW PRECIPITATION CHANCES ASSOCIATED WITH THIS FEATURE. DESPITE THE RISING 500MB HEIGHTS...IT TAKES AWHILE FOR A SIMILAR RESPONSE TO 850MB TEMPS...PARTIALLY DUE TO THAT UPPER LOW LIFTING THROUGH. THUS...TEMPERATURES HOLD NEAR SEASONABLE NORMALS UNTIL THE END OF THE WEEK. FRIDAY...SATURDAY AND SUNDAY ALL LOOK ABOVE NORMAL WITH HIGHS POSSIBLY APPROACHING 80. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1134 PM CDT FRI SEP 19 2014 ACTIVITY HAS UPSCALED ACROSS NORTHWEST IOWA AND SOUTHERN MINNESOTA SIMILAR TO WHAT THE MESO SCALE MODELS WERE SHOWING. AS THE CURRENT ACTIVITY CONTINUES TO MOVE EAST...EXPECT THAT KRST SHOULD BE IMPACTED BY SOME STORMS THROUGH ABOUT 07Z OR SO AND KLSE THROUGH ABOUT 09Z WITH PRIMARILY MVFR CONDITIONS EXPECTED. SOME UNCERTAINTY WHETHER ANY SHOWERS WILL LINGER/DEVELOP BEHIND THE LINE OF STORMS. THE 20.02Z HRRR AND PREVIOUS RUNS HAVE BEEN SHOWING GROWTH UP INTO WESTERN AND CENTRAL WISCONSIN WITH SOME SHOWERS IMPACTING KLSE WHILE THE 20.00Z CR-NESTNAM KEEPS EVERYTHING TO THE SOUTH. GIVEN THAT THE CURRENT ACTIVITY IS FARTHER NORTH THAN THE CR-NESTNAM CURRENTLY INDICATES WILL HAVE SOME LINGERING SHOWERS SIMILAR TO THE HRRR. VFR CONDITIONS SHOULD THEN PREVAIL THROUGH SATURDAY BEHIND THE COLD FRONT WITH NORTHWEST WINDS AND ENOUGH MIXING TO PRODUCE SOME GUSTS AT KRST. THE NEXT SHORT WAVE TROUGH WILL RAPIDLY APPROACH FROM THE NORTHWEST SATURDAY EVENING WITH MODERATE PV ADVECTION IN THE 500-300 MB LAYER. THIS IS EXPECTED TO PRODUCE SOME SHOWERS AND HAVE INCLUDED A VCSH FOR THE LAST HALF OF SATURDAY EVENING FOR BOTH SITES. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1134 PM CDT FRI SEP 19 2014 .SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT) ISSUED AT 222 PM CDT FRI SEP 19 2014 CONCERN FOCUSED ON CONVECTION/SEVERE POTENTIAL TONIGHT. WATER VAPOR/RAP 500MB ANALYSIS SHOWING A FAIRLY VIGOROUS MID-LEVEL TROUGH MOVING EAST ACROSS THE DAKOTAS. AT THE SURFACE...LOW PRESSURE WAS LOCATED OVER SOUTHERN MANITOBA CANADA WITH A TRAILING TROUGH THROUGH THE EASTERN DAKOTAS INTO CENTRAL NEB. RADAR MOSAIC SHOWING SCATTERED SHOWERS/ISOLATED THUNDER ACROSS PORTIONS OF ND INTO NORTHERN MN IN RESPONSE TO CORRIDOR OF 850MB MOISTURE TRANSPORT/310K ISENTROPIC LIFT AHEAD OF THE APPROACHING TROUGH. OTHERWISE...BREEZY SOUTH WINDS IN PLACE ACROSS THE FORECAST AREA THIS AFTERNOON WITH MOSTLY SUNNY SKIES. TEMPERATURES WERE IN THE UPPER 60S TO THE MIDDLE 70S. FOR TONIGHT...LOOK FOR THAT MID-LEVEL/SURFACE TROUGH TO ROTATE SOUTHEAST ACROSS THE AREA TONIGHT. MODELS OFFERING UP VARIOUS SOLUTIONS ON CONVECTIVE SCHEMES BASED ON FAIRLY STRONG CAP IN PLACE. THINKING WITH INCREASING 850MB MOISTURE TRANSPORT/EVENTUAL STEEPENING OF MID-LEVEL LAPSE RATES AND LIFT WITH THE TROUGH PASSAGE...THIS WILL BE ENOUGH FORCING TO SEE AT LEAST A SCATTERED BAND OF THUNDERSTORMS. THINKING THIS CONVECTION WILL INITIALLY START OUT ELEVATED IN NATURE ABOVE THE CAP...BUT THEN CAP WEAKENS LATE THIS EVENING INTO THE OVERNIGHT HOURS ALLOWING FOR AN UPTICK IN THUNDERSTORM COVERAGE. STILL THINKING THERE IS A MARGINAL SEVERE THREAT. MODEL CONSENSUS SHOWING 0-3KM MUCAPE VALUES OF 1000-200J/KG ALONG WITH EFFECTIVE BULK SHEAR AROUND 30KT. THIS COULD PRODUCE A FEW VIGOROUS/ROTATING UPDRAFTS CAPABLE OF LARGER HAIL PRODUCTION AND DAMAGING WIND POTENTIAL. LINGERING SHOWERS/THUNDERSTORMS WILL BE POSSIBLE ACROSS SOUTHERN WI INTO NORTHEAST IA ON SATURDAY AS THE TROUGH CONTINUES TO ROTATE SOUTHEAST OUT OF THE AREA. FOR LATER SATURDAY AFTERNOON INTO SATURDAY EVENING...MODELS SHOWING A FAIRLY COMPACT/VIGOROUS PV- ANOMALY ROTATING SOUTHEAST OUT OF THE NORTHERN PLAINS IN OUR AREA. THE BULK OF THE FORCING WITH THIS FEATURE SEEMS TO BE FOCUSED ALONG AND NORTHEAST OF I-94. AS SUCH...WENT WITH THE LIKELIHOOD OF SHOWERS/ISOLATED THUNDER NORTHEAST OF I-94 AND TAPERED TO LOWER-END CHANCES ACROSS NORTHEAST IA/FAR SOUTHWEST WI. WITH THE WARMER START TO SATURDAY...LOOK FOR HIGHS TO PERK UP INTO THE 70S TO A FEW LOWER 80S ALONG AND SOUTH OF I-90. LOOK FOR THE SHOWERS AND ISOLATED STORMS TO TAPER OFF/MOVE EAST OF THE AREA BY MIDNIGHT SATURDAY NIGHT WITH OVERNIGHT LOWS DIPPING INTO THE 50S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 222 PM CDT FRI SEP 19 2014 COOLER CYCLONIC FLOW ALOFT ON SUNDAY WILL PRODUCE COOLER TEMPERATURES IN THE 60S ALONG WITH BREEZY NORTHWEST WINDS. ALSO LOOKS LIKE THERE WILL ALSO BE ENOUGH INSTABILITY NORTHEAST OF I-94 TO PRODUCE A FEW SHOWERS. HIGH PRESSURE BUILDS OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION SUNDAY NIGHT. CLEAR SKIES AND LIGHT/CALM WINDS WILL SET UP IDEAL RADIATIONAL COOLING FOR AREAS OF FOG...ESPECIALLY FAVORED RIVER VALLEY LOCATIONS AND THE SANDY/BOG COUNTRY OF CENTRAL WI. PLAN ON LOWS IN THE LOWER 40S OVER CENTRAL WI...AND IN THE MIDDLE/UPPER 40S ELSEWHERE ACROSS THE FORECAST AREA. AFTER A COOL/POTENTIALLY FOGGY START...HIGH PRESSURE LOOKS TO PROVIDE A DRY/QUIET/MOSTLY SUNNY MONDAY WITH HIGHS MIDDLE 60S TO NEAR 70. FOR TUESDAY THROUGH FRIDAY...A RIDGE OF HIGH PRESSURE TRIES TO ESTABLISH ITSELF OVER THE CENTRAL CONUS. HOWEVER...MODELS SHOWING A TROUGH EJECTING OUT OF THE INTERMOUNTAIN WEST INTO THE UPPER MISSISSIPPI RIVER VALLEY BY WEDNESDAY INTO THURSDAY. BELIEVE THIS MAY BE A BIT OVER DONE...BUT WILL GO WITH MODEL CONSENSUS AT THIS POINT AND INCLUDE SMALL-END SHOWER/THUNDER CHANCES IN THE TUESDAY NIGHT THROUGH THURSDAY PERIOD. AS THE TROUGH MOVES OFF TO THE EAST...THE RIDGE RE-ESTABLISHES ITSELF ON FRIDAY FOR DRIER/WARMER CONDITIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1134 PM CDT FRI SEP 19 2014 ACTIVITY HAS UPSCALED ACROSS NORTHWEST IOWA AND SOUTHERN MINNESOTA SIMILAR TO WHAT THE MESO SCALE MODELS WERE SHOWING. AS THE CURRENT ACTIVITY CONTINUES TO MOVE EAST...EXPECT THAT KRST SHOULD BE IMPACTED BY SOME STORMS THROUGH ABOUT 07Z OR SO AND KLSE THROUGH ABOUT 09Z WITH PRIMARILY MVFR CONDITIONS EXPECTED. SOME UNCERTAINTY WHETHER ANY SHOWERS WILL LINGER/DEVELOP BEHIND THE LINE OF STORMS. THE 20.02Z HRRR AND PREVIOUS RUNS HAVE BEEN SHOWING GROWTH UP INTO WESTERN AND CENTRAL WISCONSIN WITH SOME SHOWERS IMPACTING KLSE WHILE THE 20.00Z CR-NESTNAM KEEPS EVERYTHING TO THE SOUTH. GIVEN THAT THE CURRENT ACTIVITY IS FARTHER NORTH THAN THE CR-NESTNAM CURRENTLY INDICATES WILL HAVE SOME LINGERING SHOWERS SIMILAR TO THE HRRR. VFR CONDITIONS SHOULD THEN PREVAIL THROUGH SATURDAY BEHIND THE COLD FRONT WITH NORTHWEST WINDS AND ENOUGH MIXING TO PRODUCE SOME GUSTS AT KRST. THE NEXT SHORT WAVE TROUGH WILL RAPIDLY APPROACH FROM THE NORTHWEST SATURDAY EVENING WITH MODERATE PV ADVECTION IN THE 500-300 MB LAYER. THIS IS EXPECTED TO PRODUCE SOME SHOWERS AND HAVE INCLUDED A VCSH FOR THE LAST HALF OF SATURDAY EVENING FOR BOTH SITES. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1109 PM CDT FRI SEP 19 2014 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .UPDATE... ISSUED AT 854 PM CDT FRI SEP 19 2014 FORECAST FROM THE DAY SHIFT APPEARS TO BE ON TRACK. TSTMS HAVE INCREASED OVER THE PAST HOUR IN WEST CENTRAL WI...WHERE STRONG 0-1 KM MOISTURE CONVERGENCE...THE RRQ OF A 90 KT JET STREAK AND AN INSTABILITY AXIS (MUCAPE 1000-1500 J/KG) ARE ALIGNED. EXPECT PCPN TO GRADUALLY SHIFT E/SE ACROSS THE FORECAST OVERNIGHT... AS THE LLJ VEERS WEST AND THE RRQ OF THE UPPER JET PULLS THROUGH. NOT SURE ABOUT THE COVERAGE OF THE SHRA/TSRA ACTIVITY YET...SO WILL STICK WITH HIGH CHC POPS FOR NOW. WILL MONITOR OVER THE NEXT HOUR AND SEE IF POPS NEED TO BE INCREASED. STILL ANTICIPATE THE POSSIBILITY OF A FEW STRONG STORMS...AS DEEP LAYER SHEAR IS 40-50+ KTS AND MID-LEVEL LAPSE RATES ARE STEEP (7-8 C/KM). THE PRESENCE OF A 40-50 KT LLJ WILL ALSO ENHANCE THE THREAT OF STRONG TSTM WINDS...ALTHOUGH MOST OF THE INSTABILITY WILL BE ELEVATED. && .SYNOPSIS... ISSUED AT 243 PM CDT FRI SEP 19 2014 WARM AND A BIT MORE HUMID EARLY IN THE WEEKEND...THEN BRIEFLY COOLER BEFORE TURNING MILD AND MAINLY DRY NEXT WEEK. INITIALLY LOW- AMPLITUDE BAND OF WESTERLIES ACRS SRN CANADA AND THE NRN CONUS WL UNDERGO AMPLIFICATION DURING THE WEEKEND...WITH UPR RIDGE BUILDING OVER THE INTERMOUNTAIN WEST AND A TROF DEEPENING THROUGH THE GREAT LAKES RGN. A SLOW PROGRESSION OF THE LARGE SCALE FEATURES IS EXPECTED...WITH THE POSITIVE ANOMALY ASSOC WITH THE WRN RIDGE SHIFTG TO THE JAMES BAY REGION BY THE MIDDLE OF NEXT WEEK...BEFORE THE PROGRESSION SLOWS. THAT WL LEAVE HIGH UPR HEIGHTS ACRS THE ERN CONUS LATE NEXT WEEK THROUGH THE FOLLOWING WEEKEND...WITH THE MAIN WESTERLIES WELL TO THE N ACRS CANADA. TEMPS WL START OUT ABV NORMAL...BRIEFLY DROP TO BLO NORMAL LEVELS LATE IN THE WEEKEND...THEN WARM BACK TO ABV NORMAL FOR MOST OF NEXT WEEK. THE MAIN OPPORTUNITY FOR PCPN WL OCCUR EARLY IN THE FCST PERIOD. UPR RIDGING DOMINATING THE AREA THEREAFTER WL ALLOW FOR ONLY SCT LGT SHOWERS AT MOST...AND QUITE POSSIBLY TOTALLY DRY WEATHER FOR THE MIDDLE TO LATTER PART OF THE PERIOD. && .SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 243 PM CDT FRI SEP 19 2014 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW FLATTENED MID-LEVEL TROUGHING ACROSS THE NORTHERN PART OF THE COUNTRY FROM MONTANA TO LAKE SUPERIOR. WITHIN THIS TROUGHING...SEVERAL SHORTWAVES ARE MOVING TO THE EAST AND ARE CREATING AREAS OF SHOWERS AND STORMS. ONE AREA IS LOCATED OVER NORTHERN MINNESOTA WHILE ANOTHER CLUSTER IS OVER FAR NORTHERN LAKE SUPERIOR. A FEW SHOWERS EXTENDING SOUTHWARD FROM THE LATTER CLUSTER ARE PASSING OVER N-C WISCONSIN EARLY THIS AFTERNOON. FOR THE REST OF THE AFTERNOON...THE AREA TO FOCUS ON IS OVER MINNESOTA WHERE PWATS ARE GREATER THAN 1.50 INCHES BUT STILL WAITING FOR INSTABILITY TO ARRIVE. IF THIS AREA CAN DESTABILIZE LATER THIS AFTERNOON...COULD SEE SOME STRONG STORMS DEVELOP. THE SURFACE COLD FRONT TRAILS THIS AREA AND REMAINS OVER THE EASTERN DAKOTAS. AS THE UPSTREAM SHORTWAVES AND COLD FRONT MOVE THROUGH THE REGION OVER THE NEXT 24 HOURS...PRECIP TIMING AND THUNDERSTORM POTENTIAL ARE THE MAIN FORECAST CONCERNS. TONIGHT...PIECES OF SHORTWAVE ENERGY OVER NORTHERN PLAINS WILL MOVE INTO THE WESTERN GREAT LAKES REGION THIS EVENING. ALONG THE LEADING EDGE OF THIS ENERGY...MODELS SHOW A RIBBON OF DEEP MOISTURE WITH PWATS APPROACHING 1.75 INCHES ALONG WITH INCREASING FORCING IN THE FORM OF MID-LEVEL FGEN AND UPPER DIVERGENCE WILL SAG SOUTHEAST ACROSS THE NORTHWEST HALF OF WISCONSIN THIS EVENING AND NORTHEAST WISCONSIN OVERNIGHT. VARIOUS MODELS INCLUDING THE RUC/SREF/NAM ALL DEVELOP MORE WIDESPREAD COVERAGE OF SHOWERS AND STORMS LATE THIS AFTERNOON OR EARLY THIS EVENING OVER WESTERN WISCONSIN COINCIDENT WITH A RIBBON OF ELEVATED CAPES UPWARDS OF 1000 J/KG. SPC HIGHLIGHTS THIS AREA FOR A THREAT OF STRONG TO NEAR SEVERE STORMS. THE FORCING AND RIBBON OF DEEP MOISTURE LOOK TO OUTRUN THIS INSTABILITY AXIS BY LATE IN THE EVENING AND OVERNIGHT...BUT NOT OUT OF THE QUESTION THAT A FEW STRONG STORMS (IF THEY DEVELOP) COULD MAKE IT INTO CENTRAL WISCONSIN BY MID TO LATE EVENING BEFORE WEAKENING THEREAFTER. WITH THE JET OVERHEAD...STRONG GUSTY WINDS WOULD BE THE MAIN THREAT FOLLOWED BY SMALL HAIL. COVERAGE OF SHOWERS AND STORMS SHOULD DIMINISH TO SCATTERED BY THE TIME THEY REACH NE WISCONSIN OVERNIGHT. BEHIND THE STORMS...A LOW STRATUS DECK SHOULD SPREAD ACROSS THE AREA...WHICH COULD ALSO CREATE PATCHY FOG IN SPOTS. A WARM NIGHT WITH LOWS IN THE UPPER 50S TO LOWER 60S. SATURDAY...A FEW SHOWERS AND ISOLATED STORMS WILL BE EXITING EAST-CENTRAL WISCONSIN EARLY IN THE MORNING AND MAY ALSO HAVE A FEW SHOWERS OVER N-C WISCONSIN AS WELL. BUT OTHERWISE...THE DAY SHOULD START OUT RATHER CLOUDY WITH A LOW OVERCAST DECK IN PLACE. THE LOW STRATUS WILL LIKELY SLOW THE HEATING CURVE FOR A FEW HOURS IN THE MORNING...BUT SHOULD LIFT WITH MIXING BY MID TO LATE MORNING. THE TRAILING SURFACE FRONT WILL BE MOVING ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN DURING THIS TIME BUT THE CLOUD COVER SHOULD KEEP THE FRONT RELATIVELY INACTIVE. AS IT REACHES NORTHEAST AND EAST-CENTRAL WISCONSIN BY MIDDAY TO EARLY AFTERNOON...POTENTIAL WILL BE THERE FOR DAYTIME HEATING TO CREATE SURFACE BASED INSTABILITY OVER THAT PART OF THE STATE. THE NAM GENERATES CLOSE TO 1500 J/KG OF ML CAPE OVER EAST-CENTRAL WISCONSIN ASSUMING TEMPERATURES CAN REACH INTO THE MIDDLE 70S. BUT CONVERGENCE ALONG THE FRONT IS RELATIVELY WEAK AND THERE WILL LIKELY BE A CAP TO OVERCOME. SO THINK THE POTENTIAL FOR REDEVELOPMENT OF THUNDERSTORMS IS PRETTY LOW BECAUSE OF THESE FACTORS. HIGHS IN THE UPPER 60S NORTH TO MIDDLE OR UPPER 70S SOUTH. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 243 PM CDT FRI SEP 19 2014 UPR SPEED MAX AND SHARPENING SHRTWV WL DIG SE ACRS THE FCST AREA SAT NGT AS LARGE SCALE AMPLIFICATION OCCURS. THE STG DYNAMICS WL BE FAVORABLE FOR PCPN...ESP ACRS THE N. RAISED POPS TO CATEGORICAL THERE...TAPERING TO A HIGH-END CHC ACRS THE S. INSTABILITY WON/T BE GREAT...BUT WL PROBABLY BE SUFFICIENT FOR THUNDER GIVEN THE DYANMICS. TRENDED TOWARD THE HIGH QPFS OF THE MODELS WITH THE BETTER DEFINED SFC REFLECTION. BLUSTERY...CLDY...AND MUCH COOLER CONDITIONS ARE LIKELY SUN... WITH LINGERING SHRA OVER MAINLY THE N/NE/E. TRIMMED MAX TEMPS...BUT WOULD NOT BE SURPRISED IF THEY END UP EVENTUALLY NEEDING A BIT MORE PRUNING. TEMPS SUN NGT TRICKY BECAUSE THEY/LL DEPEND ON CLDS. THINK THERE WL STILL BE ENOUGH OF A NW FLOW DOWN ACRS LAKE SUPERIOR TO KEEP THINGS A LITTLE CLOUDIER THAN MUCH OF THE GUIDANCE IS INDICATING...SO DID NOT TAKE LOWS DOWN TOO FAR. A FROST/FREEZE WOULD CERTAINLY BE POSSIBLE ACRS MUCH OF THE AREA IF WE TOTALLY CLEAR OUT. UPR HEIGHTS REBOUND QUICKLY LATER SUN NGT AND MON...SO THE COOLER WX WL BE SHORT-LIVED. MODELS HINT THAT WK SHRTWVS WORKING ARND THE WRN FLANK OF THE UPR RIDGE COULD BRUSH THE AREA AT TIMES. THAT RESULTED IN SOME LOW-CHC POPS IN THE EXTENDED FCST INITIALIZATION GRIDS. THAT/S CERTAINLY HARD TO RULE OUT SO LET THOSE RIDE IN THE FCST. BUT OVERALL...FORCING WL BE WEAK AND MOISTURE LIMITED...SO EXPECTING A MAINLY DRY PERIOD WITH ABV NORMAL TEMPS. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1103 PM CDT FRI SEP 19 2014 LLWS WILL CONTINUE TONIGHT...BUT SHOULD WEAKEN AT THE WESTERN TAF SITES BY 09Z-10Z...AND AT THE EASTERN TAF SITES BY 12Z-14Z/SAT. SCT SHOWERS AND TSTMS ARE EXPECTED TO MOVE THROUGH THE FORECAST AREA OVERNIGHT. DID ADD A TEMPO GROUP FOR TSTMS AT CWA/AUW EARLY THIS MORNING (LOW-LEVEL JET AND UPPER JET STREAK)...AND A PROB30 GROUP FOR TSTMS AT GRB/ATW/MTW IN THE EARLY AFTERNOON (COLD FRONTAL PASSAGE). MVFR CONDITIONS MAY ACCOMPANY THE SHOWERS AND STORMS. STRATUS IS EXPECTED TO SPREAD ACROSS THE FORECAST AREA OVERNIGHT INTO EARLY SATURDAY. IFR CONDITIONS ARE POSSIBLE... ESPECIALLY OVER NC/C WI. EXPECT LOW CIGS TO GRADUALLY IMPROVE AS THE COLD FRONT MOVES THROUGH THE REGION ON SATURDAY. A STRONG UPPER LEVEL DISTURBANCE WILL SPREAD SHOWERS AND ISOLD THUNDERSTORMS OVER THE REGION SATURDAY EVENING. MVFR/IFR CONDITIONS ARE POSSIBLE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE.........KIECKBUSCH SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
636 PM MDT SUN SEP 21 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 330 PM MDT SUN SEP 21 2014 AFTERNOON SATELLITE IMAGES SHOW WELL-DEFINED LOW PRESSURE AREA LIFTING NORTH/NORTHEAST ACROSS THE GREAT BASIN...WITH ARM OF MOISTURE ASSOCIATED WITH WEAK SHORTWAVE EXTENDING TO ITS N AND E ADVECTING INTO THE INTERMOUNTAIN WEST. SHOWERS WERE OBSERVED AT KCAG EARLIER THIS AFTERNOON...AND KCYS/KGJX 88D RETURNS SUGGEST THIS MOISTURE HAS MADE IT INTO THE SIERRA MADRES AND ADJACENT WRN FOOTHILL LOCATIONS. 20Z SFC ANALYSIS SHOWS 1026MB ACROSS THE DAKOTAS AND NEBRASKA WITH RETURN FLOW ALONG THE FRONT RANGE AND A WELL DEFINED SFC TROF BANKED UP ALONG THE EAST SLOPES OF THE SNOWY RANGE. LLVL CONVERGENCE ALONG THIS SFC TROF HAS COMBINED WITH 250+ J/KG OF SBCAPE AS ANALYZED FROM SPC MESOANALYSIS TO SPARK A COUPLE OF POCKETS OF DEEPER CONVECTION IN THE VICINITY OF CENTENNIAL/ WOODS LANDING/ALBANY OVR THE PAST FEW HOURS. LOW CENTER WILL REACH IDAHO BY LATE TONIGHT...WITH ARM OF MOISTURE ADVECTION CONTINUING FROM SW TO NE INTO THE CWFA. HIGH CLOUDS HAVE ALREADY BEEN ON THE INCREASE ACROSS THE AREA...BUT SHOULD SEE THESE LOWER AND THICKEN OVERNIGHT. ASCENT ASSOCIATED WITH THE UPPER-LOW WILL INCREASE TONIGHT...SO WILL SEE SHOWERS AND STORMS INCREASE ESPECIALLY ALONG AND WEST OF THE LARAMIE RANGE AS WELL. HAVE ALSO ADDED SOME FOG TO THE SRN LARAMIE RANGE PER LATEST HRRR OUTPUT. LIGHTNING WAS EVIDENT ACROSS SW COLORADO LAST NIGHT...SO IT MAKES SENSE TO KEEP IT TONIGHT UP HERE TONIGHT. 12Z MODEL OUTPUT HAS TRENDED SLOWER IN SPREADING RAIN CHANCES OUT ONTO THE ERN PLAINS...WHICH WILL LIKELY NOW HOLD OFF NOW UNTIL SOMETIME MONDAY MORNING. UPPER LOW WOBBLES THRU THE COWBOY STATE ON MONDAY...WHICH WILL EFFECTIVELY SHARPEN AND ENHANCE AFTERNOON CONVECTION ALONG THE PREFRONTAL SFC TROF/PACIFIC FRONT. BEST CONVECTIVE CHANCES ON MONDAY WILL BE TIED CLOSELY TO THE LOCATION OF THIS TROF...WHICH WILL BE WEST OF THE LARAMIE RANGE IN THE MORNING BEFORE PUSHING EAST OF THE LARAMIE RANGE MONDAY. PROGD INSTABILITY PARAMETERS LOOK FAIRLY MEAGER...WITH SBCAPES TOPPING OUT AROUND 500 J/KG. HOWEVER...WITH THE PROXIMITY OF THE UPPER WAVE COMBINED WITH DAYTIME DESTABILIZATION...WOULD EXPECT PERHAPS SOME MORE ORGANIZED CONVECTION FOR LOCATIONS EAST OF THE MOUNTAINS. SHOWER AND THUNDERSTORM CHANCES WILL DECREASE SOME FROM WEST TO EAST MONDAY NIGHT. UPPER-LOW WILL DEPART DURING THE DAY ON TUESDAY...BRINGING PRECIPITATION CHANCES TO AN END FROM WEST TO EAST. OTHERWISE... TUESDAY WILL LIKELY TURN A BIT BREEZY AND WINDS TURN WEST BEHIND THE DEPARTING PREFRONTAL SFC TROF/PACIFIC FRONT. WIND GUSTS OF 20 TO 35 MPH CAN BE EXPECTED DURING THE AFTERNOON. MONDAY WILL BE THE COOLEST DAY OF THE WEEK AS CLOUD COVER PROHIBITS THE AMOUNT OF INSOLATION. EVEN SO...EXPECT HIGH TEMPERATURES IN THE 70S/LOW 80S. HIGHS WILL WARM ABOUT 5 DEGREES OR SO ON TUESDAY...YIELDING MID 70S TO MID 80S. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 330 PM MDT SUN SEP 21 2014 NOT A WHOLE LOT OF CHANGE IN THE MODEL GUIDANCE THROUGH THE FIRST HALF OF THE EXTENDED PERIOD. SUBSTANTIAL RIDGE BUILDS OVER THE INTERMOUNTAIN WEST ON WED AND THIS WILL CAUSE TEMPS TO RISE TO AROUND 10 DEGREES ABOVE NORMAL ACROSS THE CWA. WINDS WILL BE LIGHT ON WED WITH WEAK SFC GRADIENTS AND FLOW ALOFT. NOT MUCH CHANGE FOR THURS EXCEPT THAT SOUTH-TO-SOUTHEAST WINDS WILL BE BREEZY DURING THE AFTN ACROSS THE PLAINS DUE TO PRESSURE FALLS OVER MONTANA. THE MODELS CONTINUE TO EXHIBIT DIFFERENCES AS WE HEAD INTO NEXT WEEKEND. THE GFS IS YET AGAIN THE MOST PROGRESSIVE WITH THE WESTERN UPPER TROUGH...MOVING ITS AXIS TO NEAR UTAH BY SAT. WIDESPREAD PRECIP IS PROGGED BEHIND THE COLD FRONTAL PASSAGE ON SAT NIGHT...SOME OF WHICH COULD BE SNOW OVER THE MTNS. THE ECMWF SHOWS A CUTOFF OVER CALIFORNIA ON SAT WHICH WOULD SIGNIFICANTLY DELAY A COOLDOWN AND IS A MUCH DRIER SOLN. WITH SUCH BIG DIFFERENCES ALMOST A WEEK OUT DECIDED TO INCREASE CLOUD COVER ON SAT BUT KEEP ONLY SLIGHT CHANCE POPS ON SAT NIGHT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY AFTERNOON) ISSUED AT 636 PM MDT SUN SEP 21 2014 SHOWERS AND T-STORMS WILL CONTINUE OFF AND ON TONIGHT FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE AS A PACIFIC STORM SYSTEM APPROACHES FROM THE WEST. VFR CONDITIONS SHOULD PREVAIL AS THIS ACTIVITY IS EXPECTED TO REMAIN WEAK...WITH THE EXCEPTION OF KCYS AS PATCHY IFR STRATUS IS POSSIBLE OVERNIGHT IN SOUTH-SOUTHEAST UPSLOPE FLOW. IN ADDITION...WINDS AT MOST SITES WILL INCREASE OVERNIGHT...WITH SPEEDS OF 10 TO 15 KTS LIKELY THROUGH THE MORNING. GUSTS OF 20 TO 30 KTS WILL THEN BE POSSIBLE THROUGH MONDAY AFTERNOON...WITH T-STORM COVERAGE TO INCREASE ACROSS THE EASTERN PLAINS. && .FIRE WEATHER... ISSUED AT 330 PM MDT SUN SEP 21 2014 SHOWER AND THUNDERSTORM CHANCES TO INCREASE TONIGHT AND MONDAY. THIS WILL KEEP FIRE WEATHER CONCERNS MINIMAL THROUGH AT LEAST TUESDAY. AN AREA OF LOW PRESSURE WILL BRING RELATIVELY GOOD CHANCES OF WETTING RAINS TO THE DISTRICTS TONIGHT THROUGH MONDAY EVENING. DO NOT ANTICIPATE SIGNIFICANT RAINFALL TOTALS...HOWEVER A FEW TENTHS OF AN INCH WILL BE A POSSIBILITY IN THE HEAVIEST SHOWERS/STORMS. DRIER AND WARMER CONDITIONS WILL RETURN TUE-FRI. EVEN SO MINIMUM RELATIVE HUMIDITIES ARE STILL ONLY EXPECTED TO BOTTOM OUT NEAR 20 PERCENT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...HAHN LONG TERM...FINCH AVIATION...RJM FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1204 AM MDT SAT SEP 20 2014 .UPDATE... ISSUED AT 913 PM MDT FRI SEP 19 2014 A NUMBER OF OUTFLOW BOUNDARIES HAVE BEEN SITUATED ACROSS EASTERN LARAMIE COUNTY THIS EVENING...AND INTERACTED WITH WHAT APPEARS TO BE A PREFRONTAL TROUGH MOVING EAST ACROSS THE CWA TO MAINTAIN DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE I-80 CORRIDOR. A FEW SHOWERS CONTINUE TO POP UP AT THIS HOUR FROM EASTERN LARAMIE COUNTY AND POINTS TO THE EAST...BUT THINK THE MAIN SFC AND MID LEVEL FORCING HAS PUSHED SOUTH AND EAST OF THE CWA BASED ON SATELLITE IMAGERY. WILL KEEP WIDELY SCATTERED COVERAGE FOR SHOWERS WITH MENTION OF ISO-T THROUGH 06Z FOR THIS AREA...BUT THIS MAY BE OVERLY OPTIMISTIC BASED ON RADAR TRENDS ALREADY TAKING A DOWNWARD TURN. THE MAIN SFC COLD FRONT LOOKS TO BE JUST NORTH OF THE CWA AND WILL CONTINUE TO MOVE SOUTH OVERNIGHT. FOCUSED HIGHEST CLOUD COVER ALONG THE LARAMIE RANGE THROUGH THE EARLY MORNING HOURS AS MODELS HINT AT A SCT STRATUS DECK ACCOMPANYING THE FRONT ALONG WITH NORTH-NORTHEAST UPSLOPE FLOW. OTHERWISE...FORECAST IS IN GOOD SHAPE. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 350 PM MDT FRI SEP 19 2014 NEAR TERM FORECAST CONCERNS REVOLVE AROUND PCPN CHANCES FOR THE REST OF THE AFTN AND EVE. WATER VAPOR SATELLITE SHOWS A WELL PRONOUNCED UPPER-LEVEL SHORTWAVE MOVING ACROSS NORTHWEST WY AT 20Z. ASSOCIATED SFC COLD FRONT HAS MADE LITTLE FORWARD PROGRESS THIS AFTN...ANALYZED FROM SOUTHWEST TO NORTHEAST ACROSS THE STATE. THIS FEATURE COMBINED WITH MODEST LARGER SCALE SUPPORT SHOULD SERVE AS A FOCUS FOR SHOWER AND TSTM DEVELOPMENT IN THE NEXT FEW HOURS. HRRR HAS BEEN CONSISTENT WITH SHOWING ISOLATED ACTIVITY FROM SOUTHEAST WY INTO THE SOUTHERN NE PANHANDLE BETWEEN 22Z AND 02Z. LACK OF SUBSTANTIAL FORCING SHOULD KEEP THINGS ISOLATED. GFS AND NAM BUFKIT SOUNDINGS INDICATE INVERTED V LLVL PROFILES OVER MUCH OF THE CWA. DCAPES AROUND 1300 J/KG ON THE LATEST SPC MESOANALYSIS SUGGESTS GUSTY OUTFLOW WINDS COULD BE A BIT OF A PROBLEM TONIGHT. DID NOT MENTION IN THE GRIDS WITH COVERAGE NOT HIGH ENOUGH TO WARRANT. COLD FRONT IS PROGGED TO SWEEP ACROSS THE CWA BY LATE TONIGHT. DRIER AIR WILL SLOWLY WORK INTO THE AREA...ENDING CHANCES FOR PCPN FROM NW TO SE BY 06Z SAT. GFS AND NAM SHOW H7 TEMPS COOLING TO 6 TO 8 DEG C OVER THE PLAINS BY SAT AFTN...DOWN FROM AROUND TODAY`S 13 C OVER CYS PER A RECENT LAPS SOUNDING ANALYSIS. DRY COLUMN OVERHEAD FOR SAT AS HIGH-AMPLITUDE UPPER RIDGING TAKES OVER...SO LOOKING AT MOSTLY SUNNY SKIES AND A SUBSTANTIAL COOL DOWN FROM TODAY`S HIGHS. NEXT CONCERN IS A LARGE CUTOFF LOW CURRENTLY SEEN ON WATER VAPOR SATELLITE OVER WEST CENTRAL CALIFORNIA. THIS FEATURE WILL LIFT SLOWLY NORTHEAST ON SUN WITH INCREASING 700-300 MILLIBAR MOISTURE OVER CARBON COUNTY BY 12Z. MOISTURE AND QG ASCENT OVERSPREADS THE CWA THROUGH THE REMAINDER OF THE FCST PERIOD. LLVL UPSLOPE AND SOME CLOUD COVER SUGGESTS SUN AFTN SHOULD BE QUITE COOL. THE MAJORITY OF MOS GUIDANCE SUGGESTS HIGHS AT 70F OR BELOW AS A GENERAL RULE...SO TRENDED LOWER ON TEMPS. ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE FROM SW TO NE DURING THAT TIME FRAME. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 350 PM MDT FRI SEP 19 2014 MODELS ARE IN GOOD AGREEMENT AT SHOWING THE UPPER LOW OVER THE GREAT BASIN MOVING EASTWARD ON MON AND LOCATED OVER NORTHERN WY BY THE AFTN. GOOD UPPER LEVEL DIFFLUENCE WILL DEVELOP DURING THE DAY...ESPECIALLY ACROSS THE PLAINS. SCATTERED SHOWERS AND TSTMS WILL BE POSSIBLE THROUGH THE DAY. LOOKING AT SOUNDINGS AND CONVECTIVE PARAMETERS OVER THE NEBRASKA PANHANDLE...COULD SEE A FEW STRONGER STORMS WITH SMALL HAIL. MID LEVEL LOW CONTINUES EASTWARD INTO SOUTH DAKOTA ON MON NIGHT AND TUES WITH LARGE SCALE SUBSIDENCE FOLLOWING. PRECIP CHANCES COME DOWN ON TUES AS THE BEST LIFT AND MOISTURE IS WELL EAST...HOWEVER KEPT SLIGHT CHANCE POPS DURING TH AFTN WITH WEAK INSTABILITY COMBINED WITH MODEST MID LEVEL MOISTURE ON THE BACKSIDE OF THE LOW. IT WILL BE BREEZY ON TUES WITH ENHANCED NORTHWEST FLOW ALOFT AND GOOD MIXING. THE REMAINDER OF THE LONG TERM WILL FEATURE INCREASING HEIGHTS AS A RIDGE BUILDS OVER THE INTERMOUNTAIN WEST IN ADVANCE OF A LARGE SCALE TROUGH OFF THE WEST COAST. TEMPS WILL BE SLIGHTLY ABOVE SEASONAL NORMS AND WINDS WILL BE RELATIVELY WEAK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1200 AM MDT SAT SEP 20 2014 WINDS WILL SHIFT TO NORTH AND NORTHEAST WITH THE PASSAGE OF A WEAK COLD FRONT. UPSLOPE MAY LEAD TO SCATTERED LOW STRATUS ALONG THE LARAMIE RANGE BY SATURDAY MORNING. OTHERWISE...VFR WILL PREVAIL. EAST TO NORTHEAST WINDS WILL BE BREEZY AT TIMES FOR THE PLAINS SATURDAY. && .FIRE WEATHER... ISSUED AT 350 PM MDT FRI SEP 19 2014 A WEAK COLD FRONT WILL MOVE ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE TONIGHT. ISOLATED TO WIDELY SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE THROUGH THE AFTN AND EVE WITH GUSTY OUTFLOW WINDS THE PRIMARY HAZARD. COOLER AND DRIER FOR SAT IN THE POST-FRONTAL AIR MASS WITH LITTLE OR NO CHANCE FOR PCPN. THE NEXT CHANCE FOR WETTING RAINS WILL BE FROM SUN NIGHT THROUGH TUE AS A POTENT WEATHER SYSTEM MOVES SLOWLY NORTHEAST ACROSS THE REGION. CRITICAL FIRE WEATHER IS NOT EXPECTED IN THE FORESEEABLE FUTURE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...RJM SHORT TERM...HAMMER LONG TERM...FINCH AVIATION...JAMSKI FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1110 PM MDT SUN SEP 21 2014 .UPDATE... ISSUED AT 856 PM MDT SUN SEP 21 2014 UPDATED TO ADJUST POPS BASED ON THE CURRENT RADAR AND SATELLITE TRENDS. A LARGE UPPER LEVEL LOW IS SPINNING ACROSS NORTHEAST NEVADA WITH AN UPPER DISTURBANCE IN THE FLOW LIFTING INTO THE FOUR CORNERS REGION. AN INCREASE IN THUNDERSTORM ACTIVITY IS NOTED OVER THE FOUR CORNERS WHICH WILL SPREAD EASTWARD ACROSS THE CONTINENTAL DIVIDE THROUGH MIDNIGHT. THERE HAVE BEEN SOME LIGHT ECHOES OVER THE I-25 CORRIDOR AND RATON MESA AREA...BUT NOTHING TOO ORGANIZED AT THIS TIME. MODELS ARE ALL STILL GENERATING A DECENT BAND OF SHOWERS AND THUNDERSTORMS LIFTING ACROSS THE AREA OVERNIGHT BUT FEEL THEY MAY BE OVER DOING THINGS A BIT. FOR NOW HAVE THE HIGHEST POPS AFTER MIDNIGHT ALONG THE SAN JUAN RANGE...WITH DECREASING CHANCES AS YOU HEAD EAST INTO THE PLAINS. MODELS HAVE NOT HANDLED OVERNIGHT CONVECTION WELL THE PAST COUPLE OF NIGHTS...SO WE WILL SEE HOW THINGS UNFOLD OVER THE NEXT COUPLE OF HOURS. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 322 PM MDT SUN SEP 21 2014 ...HEAVY RAIN POSSIBLE TONIGHT OVER SAN JUAN MOUNTAINS...MARGINAL SEVERE POSSIBLE ON PLAINS TOMORROW AFTERNOON... CURRENTLY... DRIER AIR NOTED OVER PLAINS AS DWPTS OVER FAR EC COLO IN THE 30S...WITH U40S/50S ALONG THE I-25 CORRIDOR. MTNS MAINLY IN THE 40S...WITH MUCH RICHER MOISTURE SW OF THE FCST AREA. AREA OF RAIN OVER THE CONTDVD EARLIER HAS DISSIPATED...ALTHOUGH CONVECTIVE SHOWERS WERE DEVELOPING OVER MOST OF THE HIGHER TRRN. A FEW ISOLD POPS WERE NOTED OVER FAR N EL PASO COUNTY. A FEW CG FLASHES WERE NOTED WITH THE DEVELOPING CONVECTION...BUT THE BRUNT OF THE INTENSE LTG ACTIVITY WAS STILL ASSOCIATED WITH THE TROUGH BACK INTO E UTAH. REST OF THIS AFTERNOON INTO TONIGHT... MAIN CONCERN THIS PERIOD WILL BE THE MOUNTAINS ALONG THE CONTDVD...ESPECIALLY THE SAN JUANS. ALL GUIDANCE IS INDICATING BEST CHANCE OF HEAVY PRECIP WILL BE OVER THE SW FACING SLOPES OF THE SAN JUANS. MOST OF THE PRGD HEAVY PRECIP WILL BE IN NWS GJT AREA OF RESPONSIBILITY...BUT SOME OF THIS PRECIP WILL LIKELY MAKE IT OVER THE DIVIDE. WILL WAIT TIL LATE THIS AFTERNOON TO DECIDE IF A FLASH FLOOD WATCH IS NEEDED. PROS FOR A WATCH IS MODEL FCST...BUT WE (NWS PUB) REALLY HAVE NOT RECEIVED HEAVY RAIN OVER THIS REGION SO SOILS ARE NOT ALL THAT SATURATED. 18Z NAM HAS BEEN SHOWING LOTS OF PRECIP OVER THE GREATER PIKES PEAK REGION BUT I AM DISCOUNTING THIS DUE TO ITS POOR PERFORMANCE THE LAST SEVERAL RUNS. RAP GUIDANCE IS QUITE A BIT DRIER. GFS ALSO A LOT DRIER PIKES PEAK REGION. OVER THE REST OF THE REGION...I DONT THINK THE PLAINS WILL SEE MUCH IN THE WAY OF PRECIP THE REST OF THIS AFTERNOON OR TONIGHT. SOME SHOWERS WILL BE POSSIBLE MAINLY WEST OF THE INTERSTATE...AND ACROSS N EL PASO COUNTY...BUT THE REST OF THE REGION SHOULD REMAIN DRY. SOME LOW CLOUDS/FOG WILL BE POSSIBLE ACROSS N EL PASO COUNTY TONIGHT GIVEN THE MOIST UPSLOPE FLOW. TOMORROW.... TROUGH ALOFT WILL MOVE ACROSS THE REGION. IT APPEARS NOW THAT THE SFC TROUGH WILL REMAIN IN COLORADO DURING PRIME HEATING AND WE WILL LIKELY HAVE A BROKEN LINE OF CONVECTION MOVE ACROSS THE PLAINS DURING THE AFTERNOON TIME PERIOD. SHEAR LOOKS GOOD BUT CAPE LOOKS MARGINAL SO SVR THREAT WILL BE MINIMAL. QUITE A FEW CLOUDS MAY BE OVER THE AREA TOMORROW AND THAT COULD LIMIT HEATING. MOUNTAINS SHOULD GRADUALLY DRY OUT TOMORROW. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 322 PM MDT SUN SEP 21 2014 MONDAY NIGHT...THE UPPER LOW WILL TRACK E ACROSS WY AND INTO THE DAKOTAS MON EVE...GRADUALLY BRINGING AN END TO PCPN FROM WEST TO EAST. CONVECTION IS FORECAST TO BECOME ISOLATED BY MIDNIGHT ACROSS THE FAR E PLAINS...THEN COME TO AN END EARLY TUE MORN ALONG THE CO/KS BORDER. TUESDAY AND WEDNESDAY...A RIDGE OF HIGH PRESSURE BUILDS OVER THE REGION...ALLOWING FOR PREDOMINANTLY DRY CONDITIONS AND MAX TEMPS IN THE 80S FOR THE PLAINS...AND 70S FOR THE HIGH VALLEYS. ISOLATED CONVECTION IS EXPECTED TO LINGER OVER THE FAR SE CORNER AS WELL AS THE SOUTHERN PORTIONS...INCLUDING THE S SANGRES. THURSDAY AND FRIDAY...THE UPPER RIDGE BEGINS TO SLIDE TO THE EAST...AS AN UPPER TROUGH OF LOW PRESSURE BEGINS TO MOVE ONSHORE ALONG THE WEST COAST. THIS WILL START TO DRAW INCREASING MOISTURE UP ACROSS THE 4 CORNERS AND INTO WESTERN CO...WHICH IN TURN INCREASES POPS FOR THE MTS AND WESTERN AREAS FROM THU AFTN ONWARD. A SLIGHT COOLING TREND IS EXPECTED FROM THU THROUGH FRI...THOUGH TEMPS WILL STILL BE AT OR SLIGHTLY ABOVE SEASONAL NORMS. SATURDAY AND SUNDAY...EXTENDED MODELS AGREE ON MOVING THE UPPER TROUGH AXIS ACROSS THE PAC NW AND GREAT BASIN ON SAT...THROUGH THE EC IS JUST A BIT SLOWER. THE TROUGH DEEPENS WITH A CLOSED LOW DEVELOPING BY SUN...WHICH THEN SLOWLY MOVES EAST TOWARD COLORADO. THE EC HAS THIS LOW OVER NV...WHILE THE GFS HAS THIS LOW EDGING INTO THE WESTERN HALF OF COLORADO...SO STILL SOME ROOM FOR NEGOTIATION THERE. END RESULT IS THAT A COOLER PERIOD WITH INCREASED CLOUDS AND PCPN COVERAGE IS FORECAST FOR THE WEEKEND...AND THE FINER POINTS AND TIMING WILL HAVE TO BE REVISITED THROUGHOUT THE UPCOMING WORK WEEK. MOORE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1104 PM MDT SUN SEP 21 2014 KALS...THERE SHOULD BE AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY OVER THE SAN JUAN MOUNTAINS TONIGHT WHICH MAY MOVE INTO THE SAN LUIS VALLEY THROUGH MONDAY MORNING. IF ONE OF THESE CELLS MOVES OVER THE TERMINAL...IT COULD PRODUCE REDUCED VIS AND CIGS. DO EXPECT CIGS TO FALL BY 08Z TONIGHT WITH MVFR TO IFR CONDITIONS INTO MONDAY MORNING. IMPROVING CONDITIONS ARE FORECAST BY MONDAY AFTERNOON. KCOS AND KPUB...LIGHT EAST TO SOUTHEASTERLY FLOW WILL KEEP MOISTURE IN PLACE ACROSS THE TERMINALS TONIGHT WHICH WILL LEAD TO LOWERED CIGS...ESPECIALLY AT KCOS WHERE THEY WILL LIKELY FALL TO MVFR TO IFR TONIGHT. THERE REMAINS UNCERTAINTY ON SHOWER ACTIVITY TONIGHT...AS MODELS ARE OVER DOING IT RIGHT NOW...BUT LEFT VCSH IN THE FORECAST TO ACCOUNT FOR THIS UNCERTAINTY. THERE IS ALSO THE POSSIBILITY FOR STRONG THUNDERSTORMS AT KCOS AND KPUB MONDAY AFTERNOON. HAIL AND GUSTY OUTFLOW WINDS ARE POSSIBLE WITH STRONGER STORMS. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY SHORT TERM...HODANISH LONG TERM...MOORE AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
145 AM EDT MON SEP 22 2014 .SYNOPSIS... A PERIOD OF STEADY RAIN WILL AFFECT THE FAR SOUTHEAST NEW ENGLAND COAST THIS EVENING. OTHERWISE...DRIER AND LESS HUMID WEATHER IS ON TAP FOR MONDAY AS A DRY COLD FRONT SWEEPS ACROSS THE REGION. STRONG HIGH PRESSURE WILL BRING SUNNY DAYS AND CLEAR NIGHTS TO THE REGION FROM TUESDAY THROUGH NEXT WEEKEND WITH A WARMING TREND. WE COULD APPROACH RECORD WARMTH ON SATURDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 130 AM UPDATE... OVER THE LAST HOUR OR TWO...WINDS HAVE SHIFTED TO THE W AS ISALLOBARIC COUPLET SUPPORTS RAPID PRES RISES TO THE W AND FALLING TO THE E AS LOW PRES SLIDES TOWARD NOVA SCOTIA. THIS SHIFT HAS LEAD TO A DRYING TREND AND REDUCTION IN THE OVERALL FOG COVERAGE. WILL MAINTAIN CURRENT SPS/S AND ADVISORIES FOR THE TIME BEING THOUGH AS THE ACTUAL FRONT IS NOW ONLY JUST E OF THE CT VALLEY AND WILL TAKE 3-6 MORE HOURS TO CLEAR. OTHERWISE...FORECAST MAINLY ON TRACK AS REMNANT SHOWERS CONTINUE TO DRY AS THEY REACH THE DOWNSLOPING IN THE E SLOPES OF THE BERKSHIRES. PREVIOUS DISCUSSION... MARGINAL INSTABILITY WITH DEEP LOW LEVEL MOISTURE HAS ALLOWED ISOLATED TO SCATTERED SHOWERS TO CONTINUED TO AFFECT SOUTHERN NEW ENGLAND. WE SHOULD SEE THIS ACTIVITY DIMINISH EARLY THIS EVENING WITH THE LOSS OF DAYTIME HEATING. THE MAIN CONCERN WILL BE THE SURFACE LOW PRESSURE SYSTEM OFF THE MID ATLANTIC COAST WHICH WILL BE TRACKING NORTHEAST AND PASSING NEAR THE BENCHMARK THIS EVENING. THE MAIN QUESTION IS HOW FAR NORTHWEST THE RAIN SHIELD WILL GET. LATEST NEAR TERM GUIDANCE HAS BEEN TRENDING FURTHER NORTHWEST. THEREFORE...EXPECT A PERIOD OF STEADY RAIN ACROSS THE CAPE/ISLANDS AND PROBABLY FURTHER NORTHWEST INTO INTERIOR SOUTHEAST MA/RHODE ISLAND FOR AT LEAST A TIME. IN FACT...LATEST HRRR SHOWING THE POTENTIAL FOR A BRIEF PERIOD OF RAIN ACROSS THE NORTHEAST MA COAST INCLUDING BOSTON. NOT SURE IF IT WILL GET THAT FAR NORTHWEST...BUT ITS CERTAINLY POSSIBLE. REGARDLESS...THE HEAVIEST RAINFALL WILL OCCUR ACROSS NANTUCKET... WHERE BETWEEN 0.50 TO PERHAPS UP TO 1 INCH OF RAIN MAY OCCUR. THE RAIN MAY PERSIST THROUGH MUCH OF THE EVENING ACROSS THE CAPE AND ISLANDS...BUT SHOULD WIND DOWN NEAR OR JUST AFTER MIDNIGHT. MEANWHILE...ONCE THE ISOLATED TO SCATTERED DIURNALLY DRIVEN SCATTERED SHOWERS WIND DOWN EARLY THIS EVENING...THE REST OF THE REGION WILL MAINLY BE DRY TONIGHT. HOWEVER...A COLD FRONT WILL BE APPROACHING OUR WESTERN ZONES TOWARD MIDNIGHT. WHILE SHEAR IS QUITE IMPRESSIVE...VERY LITTLE INSTABILITY WILL BE LEFT. SO WHILE WE MAY SEE A FEW SPOT SHOWERS AFFECT OUR WESTERN ZONES...THEY WILL BE IN THE PROCESS OF WEAKENING AND NOT EXPECTING MUCH MORE THAN THAT. LOW TEMPS WILL ONLY BOTTOM OUT IN THE UPPER 50S AND THE LOWER 60S BY DAYBREAK MONDAY. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... MONDAY... A MUCH DRIER AIRMASS WILL WORK INTO THE REGION BEHIND THE COLD FRONT ON MONDAY. WHILE PARTLY TO MOSTLY SUNNY SKIES ARE EXPECTED EARLY...MAY SEE A SCATTERED TO BROKEN DECK OF STRATO- CUMULUS CLOUDS WORK INTO AT LEAST THE INTERIOR BY AFTERNOON. HIGHS SHOULD MAINLY BE IN THE 60S ACROSS THE INTERIOR...BUT STILL WILL REACH BETWEEN 70 AND 75 ALONG HE COASTAL PLAIN. GUSTY WEST WINDS OF 20 TO 30 MPH ARE EXPECTED AS BUFKIT SOUNDINGS SHOWING VERY GOOD MIXING. HIGH SURF...GIVEN LARGE SOUTH TO SOUTHEAST SWELL FROM DEPARTING COASTAL LOW PRESSURE SYSTEM HAVE ISSUED A HIGH SURF ADVISORY FOR THE SOUTH COAST ON MONDAY. WE ISSUE HIGH SURF PRODUCTS THROUGH THE END OF SEPTEMBER IF CONDITIONS WARRANT. MONDAY NIGHT... HIGH PRESSURE WILL BE BUILDING IN FROM THE WEST. THIS WILL ALLOW FOR DIMINISHING WINDS AND SKIES TO BECOME MOSTLY CLEAR. LOOKS LIKE A PRETTY GOOD NIGHT OF RADIATIONAL COOLING...WITH LOWS BOTTOMING OUT IN THE UPPER 30S TO THE MIDDLE 40S IN MOST LOCALES. THE URBAN HEAT ISLAND OF BOSTON WILL BE THE MILD SPOT WITH THE LOW BOTTOMING OUT NEAR 50. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * HIGH PRESSURE AND DRY WEATHER THROUGH THE PERIOD * NEAR RECORD WARMTH POSSIBLE NEXT SATURDAY OVERVIEW... VERY GOOD AGREEMENT AMONGST MODEL GUIDANCE THE ENTIRE FORECAST PERIOD. AN UPPER LEVEL TROUGH DEPARTS THE NORTHEAST STATES ON TUESDAY. THEN...MUCH ADO ABOUT BUILDING HIGH PRESSURE...BOTH AT THE SURFACE AND ALOFT THE REMAINDER OF THE WEEK. THE UPPER RIDGE IS VERY STRONG AS IT IS PARKED FROM THE GREAT LAKES TO SOUTHERN NEW ENGLAND BY NEXT WEEKEND. DETAILS... TUESDAY WILL FEATURE MOSTLY SUNNY SKIES EXCEPT ONLY PARTLY SUNNY NW MA AND SW NH CLOSER TO SOME HIGHER 925 MB HUMIDITY. OTHERWISE...EXPECT SUNNY DAYS AND CLEAR NIGHTS THROUGH NEXT WEEKEND. HAVE GONE A FEW DEGREES LOWER THAN MODEL CONSENSUS TEMPERATURE MINIMUMS THROUGH THU DUE TO EXCELLENT RADIATIONAL COOLING EXPECTED ALONG WITH VERY DRY DEWPOINTS. AS THE CENTER OF THE UPPER HIGH APPROACHES...AM EXPECTING A DRAMATIC WARMUP FRI AND ESPECIALLY SAT. THE 12Z ECMWF RUN IS EVEN WARMER THAN THE PREVIOUS RUN WITH 925 MB TEMPERATURES WARMING FROM +12C TUE...TO +17C FRI... TO +19C OR +20C ON SAT... WITH WARM TEMPERATURES LIKELY CONTINUING INTO EARLY THE FOLLOWING WEEK. HAVE GONE SEVERAL DEGREES ABOVE MODEL CONSENSUS MAXIMUMS FOR NEXT SATURDAY...WITH HIGHS SOARING TO 80 TO 85 ACROSS INTERIOR SOUTHERN NEW ENGLAND. RECORDS FOR THAT DAY INCLUDE 85 AT WORCESTER AND 86 AT BOTH BOSTON AND PROVIDENCE. LIGHT WINDS ARE EXPECTED FOR THE PERIOD...SO ALTHOUGH IT WILL BE DRY WE ARE NOT EXPECTING FIRE WEATHER CONCERNS. LOCAL SEA BREEZES WILL OCCUR...ESPECIALLY FRI THROUGH NEXT SUNDAY. IT SHOULD BE NOTED THAT THE GFS HAS A HINT OF A POTENTIAL BACKDOOR FRONT/TROUGH OVER NORTHEAST MA ON SAT BUT THIS WAS NOT ENOUGH TO DETRACT FROM THE VERY WARM FORECAST...AS YET. AN UPPER LOW OVER VIRGINIA AND AN ASSOCIATED INVERTED TROUGH IS LIKELY TO BE CAUSING PRECIPITATION IN THE MID ATLANTIC REGION MID TO LATE IN THE WORK WEEK THAT TRIES TO WORK ITS WAY NORTHWARD. THERE IS EXCELLENT MODEL AGREEMENT THAT THIS AREA ONLY GETS AS FAR NORTHWARD AS OFF THE NJ COAST BY FRI...BEFORE RETREATING SOUTHWARD AS STRONG HIGH PRESSURE BECOMES ESTABLISHED OVER THE NORTHEAST ON THE WEEKEND. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/... THROUGH 12Z...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN TIMING. WITH A MIX OF ALL CATEGORIES...EXPECT THE GENERAL TREND THROUGH 12Z WILL BE TOWARD VFR FROM W-E. TIMING IN TAFS MAY BE OFF BY AN HOUR OR SO...BUT ONCE WINDS PICK UP AND SHIFT MORE W-NW VFR SHOULD DOMINATE THEREAFTER. TODAY INTO TUESDAY...HIGH CONFIDENCE. VFR...ALTHOUGH MVFR/IFR CONDITIONS MAY LINGER AT ACK THROUGH MID MORNING. WINDS MAINLY WNW TODAY...GUSTING TO AROUND 25 KT AT TIMES THEN DIMINISHING OVERNIGHT. KBOS TERMINAL...HIGH CONFIDENCE FOR MAINLY VFR FROM NOW ON. KBDL TERMINAL...HIGH CONFIDENCE FOR MAINLY VFR FROM NOW ON. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... HIGH CONFIDENCE. TUE...VFR. WED...VFR THU...VFR. FRI...VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... TONIGHT...MODERATE TO HIGH CONFIDENCE. LOW PRESSURE PASSING NEAR THE BENCHMARK WILL RESULT IN ENOUGH SOUTH TO SOUTHEAST SWELL FOR SCA SEAS TO DEVELOP ACROSS THE OUTER-WATERS AND WESTERN SOUNDS. SOUTHEAST WINDS SHOULD BECOME SOUTHWEST TONIGHT AT 10 TO 15 KNOTS LATER TONIGHT. AREAS OF FOG...SOME LOCALLY DENSE...WILL OCCUR ACROSS THE WATERS...ESPECIALLY SOUTH OF BOSTON HARBOR. MONDAY AND MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. SCA SEAS ON THE WESTERN SOUNDS AND OUTER-WATERS WILL CONTINUE THROUGH MONDAY NIGHT. IN ADDITION...A PERIOD OF WEST TO NORTHWEST WIND GUSTS NEAR 25 KNOTS IS POSSIBLE FOR A TIME ON MONDAY. THEREFORE...IT IS POSSIBLE WE MAY NEED TO EXPAND SCA FOR A TIME DURING THE DAY MONDAY INTO SOME OF THE NEARSHORE SOUNDS AND WATERS. CONFIDENCE NOT QUITE HIGH ENOUGH TO DO THIS RIGHT NOW... SO WILL DEFER TO THE NEXT SHIFT. OUTLOOK...TUESDAY THROUGH FRIDAY... HIGH CONFIDENCE... TUE AND WED...SEAS NEAR 5 FT MAY LINGER AT TIMES TUE AND WED OVER THE WATERS S AND E OF NANTUCKET. OTHERWISE WINDS AND SEAS SHOULD BE BELOW SMALL CRAFT ADVISORY CRITERIA. A NORTHEAST WIND GRADIENT WILL INCREASE OVER THE SOUTHERN COASTAL WATERS TUE NIGHT INTO WED AS STRONG HIGH PRESSURE PUSHES INTO NORTHERN NEW ENGLAND. BUT GUSTS ARE EXPECTED TO ONLY REACH 20 KT. WED NIGHT THROUGH FRI...QUIET BOATING WEATHER WITH HIGH PRESSURE DOMINATING THE WEATHER. WINDS AND SEAS BELOW SCA THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...HIGH SURF ADVISORY FROM 8 AM THIS MORNING TO 5 PM EDT THIS AFTERNOON FOR MAZ020>024. DENSE FOG ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR MAZ006-007-014. NH...NONE. RI...HIGH SURF ADVISORY FROM 8 AM THIS MORNING TO 5 PM EDT THIS AFTERNOON FOR RIZ006>008. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR ANZ250-254>256. SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 4 PM EDT THIS AFTERNOON FOR ANZ251. && $$ SYNOPSIS...FRANK/GAF NEAR TERM...FRANK/DOODY/GAF SHORT TERM...FRANK LONG TERM...GAF AVIATION...DOODY/GAF MARINE...FRANK/GAF
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
138 AM EDT MON SEP 22 2014 .PREV DISCUSSION... /ISSUED 1008 PM EDT SUN SEP 21 2014/ UPDATE... CONVECTION CONTINUES TO SLIDE SOUTHWARD ACROSS NORTH GEORGIA AND THERE IS SOME UNCERTAINTY IN HOW THE PRECIP WILL PLAY OUT LATE TONIGHT INTO MONDAY. OVERALL HAVE CHOSEN TO SHOW IT CONTINUING TO SINK SOUTHWARD...BUT DECREASE THE COVERAGE FROM SCATTERED TO ISOLATED OVERNIGHT. HRRR EXPANDS AREA OF PRECIP BY 14Z WHILE THE LOCAL WRF ISNT QUITE THAT BOLD. CONSIDERING HRRR HAS BEEN OVERDONE THIS SUMMER OVERALL...HAVE LEANED MORE TOWARDS THE LOCAL WRF. POP GRIDS MAY STILL BE A TAD UNDERDONE THOUGH FOR LATE TONIGHT INTO MONDAY. MADE A SLIGHT INCREASE IN POPS ACROSS THE FAR SOUTHEAST PART OF THE CWA FOR MONDAY AFTERNOON AS VORT MAX MAY HELP TO INCREASE CONVECTION. PREV DISCUSSION... SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... /ISSUED 317 PM EDT SUN SEP 21 2014/ COLD FRONT IS PUSHING INTO THE TENNESSEE VALLEY AT AFD TIME WITH ISOLATED SHOWERS DEVELOPING ALONG AND JUST AHEAD OF IT. CAPE VALUES ARE ON THE LOW END...GENERALLY BELOW 1500 J/KG ACROSS NORTH GEORGIA...AND BEST PVA IS ACTUALLY BEHIND THE FRONT AND DOES NOT PUSH INTO GEORGIA REALLY UNTIL MONDAY SOMETIME. SO HAVE KEPT TREND OF SLIGHT TO LOW CHANCE POPS WITH WORDING LIMITED TO ONLY SLIGHT CHANCE THUNDER...ESPECIALLY SINCE WHAT CAPE MIGHT BE AROUND THIS AFTERNOON QUICKLY DECREASES OVERNIGHT. DRY AIR STARTS FILTERING INTO NORTH GEORGIA BEHIND THE FRONT BUT NEW RUNS ARE A LITTLE SLOWER WITH THIS SO LOW TEMPS TONIGHT NOT FORECAST QUITE AS COOL AS WITH EARLIER FORECASTS. CONVECTION SHOULD FIRE ACROSS CENTRAL GEORGIA MONDAY AFTERNOON AND WITH A PRETTY STRONG VORT LOBE SWINGING AROUND WITH THE SHARP TROUGH ALOFT...EXPECT TO SEE A LITTLE MORE CONVECTIVE DEVELOPMENT THEN. MUCAPES INCREASE TO BETWEEN 800-1500 J/KG ACROSS CENTRAL GEORGIA TOMORROW DEPENDING ON WHICH MODEL ONE USES /NAM IS HIGHER AS USUAL/. STILL HAVE LOW TO MID-RANGE CHANCE POPS AT BEST BUT WILL HAVE TO REEVALUATE THIS OVERNIGHT. DEEP-LAYER CAA BEHIND THE FRONT IS PRETTY IMPRESSIVE ESPECIALLY EARLY TOMORROW ACROSS NORTH GEORGIA...THOUGH THE CAA MODERATES EVER SO SLIGHTLY IN THE AFTERNOON. SHOULD SEE A MARKED DIFFERENCE IN TEMPERATURES BEHIND THE FRONT TOMORROW /5-10 DEGREES COOLER EXCEPT ACROSS SOUTHERN ZONES WHERE THE FRONT WILL NOT HAVE QUITE MADE IT THROUGH YET/ AND ESPECIALLY TOMORROW NIGHT /ANOTHER 5-10 DEGREES COOLER THAN TONIGHT AGAIN EXCEPT FOR SOUTHERN ZONES/. THE DECREASE IN HUMIDITY WILL ALSO BE VERY NOTICEABLE. ENJOY THE BEAUTIFUL FALL WEATHER! TDP LONG TERM /TUESDAY THROUGH SUNDAY/... /ISSUED 317 PM EDT SUN SEP 21 2014/ HIGH PRESSURE AND COOLER TEMPERATURES WILL DOMINATE MUCH OF THE EXTENDED FORECAST PERIOD. HIGH PRESSURE SITUATED ACROSS THE CENTRAL OHIO VALLEY ON TUESDAY WILL SLOWLY SHIFT EASTWARD THROUGH THE WEEK. PROLONGED EASTERLY FLOW OFF OF THE ATLANTIC WILL HELP INCREASE THE CLOUD COVER BY WEDNESDAY. IN ADDITION...THE OLD FRONTAL BOUNDARY ACROSS NORTH-CENTRAL FLORIDA WILL BEGIN TO PUSH NORTHWARD AS A WARM FRONT BY LATE WEDNESDAY INTO EARLY THURSDAY. ISENTROPIC LIFT WILL BEGIN TO INCREASE ACROSS THE SOUTHEAST ZONES BY THE END OF THE WEEK AND SPREAD W THROUGH THE WEEKEND. INSTABILITY LOOKS MINIMAL...BUT AN ISOLD THUNDERSTORM CANNOT BE RULED OUT. NLISTEMAA && .AVIATION... 06Z UPDATE... STILL SOME SCATTERED SHRA ALONG FRONT TO DEAL WITH FOR THE NEXT FEW HOURS SO WILL EXTEND TEMPO WITH THIS TAF SET. STRONG UPPER LEVEL SYSTEM SWINGS THROUGH THIS AFTERNOON BUT DRIER AIR SHOULD PRECLUDE ADDITIONAL SHRA DEVELOPMENT AND WILL KEEP ATL AREA TERMINALS RAIN FREE FOR THIS AFTERNOON. MCN WILL NOT BE SO LUCKY WITH NOT ONLY BETTER SHRA POTENTIAL BUT TSRA AS WELL AND WILL KEEP PROB30 FOR THEM THROUGH THE AFTERNOON HOURS. OTHERWISE...CIGS EXPECTED TO REMAIN VFR THROUGH THE PERIOD. //ATL CONFIDENCE...06Z UPDATE... MEDIUM ON SHRA POTENTIAL THIS AFTERNOON. HIGH ON REMAINING ELEMENTS. DEESE && .PRELIMINARY POINT TEMPS/POPS... ATHENS 81 56 79 55 / 20 0 0 0 ATLANTA 80 57 79 57 / 20 0 0 0 BLAIRSVILLE 74 48 76 51 / 5 0 0 0 CARTERSVILLE 78 52 80 55 / 5 0 0 0 COLUMBUS 84 59 83 61 / 20 0 0 0 GAINESVILLE 77 55 77 55 / 5 0 0 0 MACON 85 58 83 59 / 30 0 0 0 ROME 79 50 81 54 / 0 0 0 0 PEACHTREE CITY 80 52 80 55 / 20 0 0 0 VIDALIA 88 64 83 61 / 40 30 10 10 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DEESE LONG TERM....BDL AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
315 AM EDT MON SEP 22 2014 .SYNOPSIS... ISSUED AT 316 AM EDT MON SEP 22 2014 A PLEASANT START TO FALL AS HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILDS EASTWARD ACROSS THE OHIO VALLEY RESULTING IN MOSTLY CLEAR AND DRY CONDITIONS. TEMPERATURES WILL MODERATE THROUGH THE WEEK WITH HIGHS IN THE LOW 60S TODAY WARMING TO THE MID TO UPPER 70S BY FRIDAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 316 AM EDT MON SEP 22 2014 PLAINS SFC RIDGE WILL INTENSIFY EWD THROUGH THE SRN LAKES/OH VALLEY THIS PD MARKING THE START OF AN EXCEPTIONAL PD OF PLEASANT WEATHER. HWVR LL THERMAL TROUGH WILL HOLD FIRM YET TDA. COOL START AND NEUTRAL ADVTN ALOFT WITHIN CONTD NRLY SFC GRADIENT FLW WILL SUBDUE AFTN DIURNAL...ALTHOUGH THAT WILL NOT BE THE CASE ON TUE. CLR SKIES AND DECOUPLING UNDERNEATH SFC RIDGE WARRANTS CUTTING MIN TEMPS SE THIRD OVERNIGHT. && .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 316 AM EDT MON SEP 22 2014 DEEP TROUGH WILL REMAIN ANCHORED NEAR OR JUST OFF THE WEST COAST RESULTING IN A LOT OF RIDGING ACROSS THE EASTERN HALF TO TWO THIRDS OF THE CONUS. A WEAK DISTURBANCE ATTEMPTS TO PASS NEAR THE WESTERN GREAT LAKES THURSDAY BUT WILL HIT A BRICK WALL AND EITHER BE SHEARED OUT OR SHIFTED WELL NORTH OF THE AREA. THE RESULT IS A CONTINUED DRY FORECAST WITH SUNNY TO MOSTLY SUNNY DAYS AND GENERALLY CLEAR NIGHTS. ECMWF IS ADVERTISING A SLUG OF TROPICAL MSTR WORKING NORTH WITH A DISTURBANCE. EVEN IF THIS COMES TO FRUITION...NO WORRIES UNTIL MAYBE MONDAY AT THE EARLIEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 222 AM EDT MON SEP 22 2014 EVOLUTION OF WRN BOUND OF MOIST LL CYCLONIC FLW NR TERM PROBLEMATIC GIVEN LL THERMAL INVERSION IN PLACE AND AS YET STILL DEEP NRLY TRAJECTORY NOTED IN PBL. THUS EXTENSIVE MVFR STRATOCU SHIELD ACRS MI MAY CONT TO WRAP SWD AS SHOWN IN LATEST RAP MODEL GUIDANCE AS OPPOSED TO MOST OTHER 00Z BASED GUIDANCE WHICH CARRIES IT EWD OF THE TERMINALS THIS MORNING. HWVR TRIED TO KEEP SOME CONTINUITY W/PRIOR FCST BUT OF WHICH MIGHT BE TOO OPTIMISTIC. WILL MONITOR AND AMEND AS NECESSARY. OTRWS RIDGING SFC AND ALOFT BLDG THROUGH OH VALLEY AND BREAKDOWN OF LL THERMAL TROUGH PREDICATES VFR CONDS AND LIGHT WINDS FOR THE REMAINDER OF THE WEEK. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043- 046. && $$ SYNOPSIS...NG SHORT TERM...T LONG TERM...FISHER AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
223 AM EDT MON SEP 22 2014 .SYNOPSIS... ISSUED AT 740 PM EDT SUN SEP 21 2014 COOLER CONDITIONS ARE EXPECTED TONIGHT ACROSS THE REGION AS A COLD FRONT PUSHES SOUTHEAST OF THE AREA. ASIDE FROM SOME CLOUD COVER OVERNIGHT...DRY CONDITIONS AND MOSTLY CLEAR SKIES ARE EXPECTED AFTER TONIGHT THROUGH THE ENTIRE WORK WEEK. TEMPERATURES WILL GRADUALLY WARM FROM HIGHS IN THE LOW 60S MONDAY TO HIGHS IN THE MID TO UPPER 70S BY FRIDAY. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 352 PM EDT SUN SEP 21 2014 THE FORECAST CHALLENGES INCLUDE ENDING OF SHOWERS EARLY TONIGHT AND AMOUNT OF CLEARING OVERNIGHT. A SHORT WAVE TROF WAS MOVING ACROSS LOWER MICHIGAN INTO NORTHERN INDIANA THIS AFTERNOON. A SECONDARY COLD FRONT WAS ASSOCIATED WITH THIS SYSTEM FROM NORTHEAST ILLINOIS INTO SOUTHWEST LOWER MICHIGAN. VERY COLD AIR ALOFT IN ADDITION TO THE UPPER TROF AND COLD FRONT WERE SUFFICIENT TO PRODUCE SHOWERS. KEPT A MENTION OF ISOLATED THUNDER LATE THIS AFTERNOON OVER NORTHEAST GIVEN THE INSTABILITY WITH COLD AIR ALOFT. THERE WERE A FEW LIGHTNING STRIKES OVER SOUTHEAST LOWER MICHIGAN NORTH OF INTERSTATE 94 DURING THE MIDDLE OF THIS AFTERNOON. SKIES SHOULD BEGIN TO CLEAR BEHIND THE FRONT EARLY TONIGHT. SOME CONCERN FOR LAKE CLOUDS FORMING UNDER THE BASE OF A DEVELOPING INVERSION OVERNIGHT. ADDED SOME LAKE CLOUDS TONIGHT GIVEN A FAVORABLE FETCH AND INCREASING DELTA T VALUES. OTHERWISE...TEMPERATURES WILL BE CHILLY WITH LOWS AWAY FROM ANY LINGERING AREAS OF LAKE CLOUDS WELL DOWN INTO THE 40S. KEPT TEMPERATURES MUCH BELOW NORMAL MONDAY WITH HIGHS AROUND 60S MOST AREAS. && .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 352 PM EDT SUN SEP 21 2014 VERY LITTLE TO DISCUSS WITH RESPECT TO SENSIBLE WEATHER IN THE LONG TERM PERIOD. HIGH PRESSURE WILL BE ENTRENCHED OVER THE REGION THROUGH THE PERIOD. TEMPERATURES WILL SLOWLY MODERATE...TRENDING FROM BELOW NORMAL TO ABOVE NORMAL BY END OF PERIOD. IT SHOULD REMAIN DRY THROUGH THE END OF THE WEEK AND LIKELY DRY THROUGH NEXT WEEKEND. MODELS DO BEGIN TO SHOW AN INCREASE IN MOISTURE NEXT WEEKEND IN RESPONSE TO SOME TROPICAL MOISTURE WORKING TOWARD THE AREA WITH WEAK UPPER LOW UNDERCUTTING RIDGE. NO SUPPORT FOR ADDING POPS WITH LACK OF ANY STRONG UPPER AIR SUPPORT OR SFC TRIGGER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 222 AM EDT MON SEP 22 2014 EVOLUTION OF WRN BOUND OF MOIST LL CYCLONIC FLW NR TERM PROBLEMATIC GIVEN LL THERMAL INVERSION IN PLACE AND AS YET STILL DEEP NRLY TRAJECTORY NOTED IN PBL. THUS EXTENSIVE MVFR STRATOCU SHIELD ACRS MI MAY CONT TO WRAP SWD AS SHOWN IN LATEST RAP MODEL GUIDANCE AS OPPOSED TO MOST OTHER 00Z BASED GUIDANCE WHICH CARRIES IT EWD OF THE TERMINALS THIS MORNING. HWVR TRIED TO KEEP SOME CONTINUITY W/PRIOR FCST BUT OF WHICH MIGHT BE TOO OPTIMISTIC. WILL MONITOR AND AMEND AS NECESSARY. OTRWS RIDGING SFC AND ALOFT BLDG THROUGH OH VALLEY AND BREAKDOWN OF LL THERMAL TROUGH PREDICATES VFR CONDS AND LIGHT WINDS FOR THE REMAINDER OF THE WEEK. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR LMZ043- 046. && $$ SYNOPSIS...NG SHORT TERM...SKIPPER LONG TERM...LASHLEY AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1220 AM CDT MON SEP 22 2014 .UPDATE... ISSUED AT 1220 AM CDT MON SEP 22 2014 UPDATED FOR THE NEW 06Z AVIATION DISCUSSION. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 301 PM CDT SUN SEP 21 2014 MOST OF THE CLOUDS HAVE DISSIPATED ACROSS THE CWA THIS AFTERNOON...WITH A RIBBON OF THICKER CLOUDS REMAINING JUST WEST OF THE NORTHLAND. THE RAP HAS BEEN CONSISTENT ON BRINGING SOME OF THESE CLOUDS BACK INTO OUR WESTERN/NORTHERN ZONES TONIGHT. THERE IS SOME EASTWARD MOVEMENT TOWARD KOOCHICHING COUNTY OVER THE LAST SEVERAL SATELLITE IMAGES. WE HAVE DO BRING AN INCREASE IN CLOUDS OVER PARTS OF THE WEST/NORTH TONIGHT. HIGH PRESSURE WILL KEEP THE CWA DRY THROUGH MONDAY WITH MORE SUN EXPECTED. LOWS TONIGHT WILL DROP INTO THE UPPER THIRTIES TO LOWER FORTIES. WE WENT ON THE LOW END OF GUIDANCE AND EVEN DROPPED TEMPS A BIT MORE OVER PARTS OF OUR FAR NORTHEAST ZONES AND FROM KHYR TO KPBH. LATER SHIFTS WILL HAVE TO MONITOR TEMPS CLOSELY AS IF THEY DROP A BIT MORE THAN EXPECTED...SOME PATCHY FROST IS POSSIBLE. FOG WILL ALSO BE POSSIBLE TONIGHT. HIGHS MONDAY WILL BE SEVERAL DEGREES ABOVE NORMAL...AND RANGE FORM THE MID SIXTIES TO AROUND SEVENTY. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 301 PM CDT SUN SEP 21 2014 DRY CONDITIONS EXPECTED EARLY IN THE WEEK WITH AN UPPER LEVEL RIDGE BUILDING EWD ACROSS THE UPPER MIDWEST/WRN GREAT LAKES AREA. AT THE SFC A 1025MB HIGH WILL TRANSLATE EWD THROUGH THE SRN GREAT LAKES. A SLY FLOW WILL DEVELOP BEHIND THE DEPARTING HIGH AND AHEAD OF THE NEXT INCOMING AREA OF LOW PRESSURE. THIS NEXT SYSTEM WILL TRACK FROM THE ROCKIES THROUGH THE CENTRAL PLAINS DURING THE DAY TUESDAY. THE MAIN FORCING WILL REMAIN ALOFT ASSOCIATED WITH THE UPPER LOW...WHICH WILL RUN INTO A BLOCKING HIGH TO THE EAST AND LIFT TO THE NE THROUGH NRN MN AND WRN LAKE SUPERIOR LATE TUE NIGHT AND THROUGH THE DAY WED. RAIN SHOWERS WILL ACCOMPANY THIS SYSTEM...AND REMAIN CONFINED TO AREAS NORTH OF MN HIGHWAY 210 AND EWD ALONG THE SOUTH SHORE IN NW WI. RAINFALL AMTS ARE EXPECTED TO BE LIGHT. A BROAD HIGH AMPLITUDE RE-ENFORCING UPPER LEVEL RIDGE IS EXPECTED TO BUILD THROUGH THE CENTRAL U.S. ON THURSDAY...AND INTO THE GREAT LAKES BY FRIDAY. THIS HIGH PRESSURE WILL KEEP CONDITIONS DRY AND WARM THROUGH FRIDAY AND INTO THE WEEKEND. TEMPERATURES THROUGH THE WEEK WILL REMAIN RELATIVELY WARM WITH HIGHS IN THE UPPER 60S AND 70S...AND OVERNIGHT LOWS IN THE 50S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1220 AM CDT MON SEP 22 2014 VFR IS EXPECTED THROUGH MUCH OF THE FORECAST. THE EXCEPTION WILL BE WHEN BR FORMS AND VSBYS DROP INTO THE MVFR RANGE. SOME CU POSSIBLE AFTER 13Z. && .PRELIMINARY POINT TEMPS/POPS... DLH 48 70 51 68 / 0 0 10 20 INL 45 74 52 69 / 0 0 10 30 BRD 47 72 54 70 / 0 0 30 20 HYR 44 73 50 69 / 0 0 0 10 ASX 47 72 51 69 / 0 0 0 20 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...MELDE LONG TERM...BJT AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
436 AM EDT MON SEP 22 2014 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE OVER THE NORTHERN AND CENTRAL PLAINS WILL SETTLE OVER THE OHIO VALLEY TONIGHT AND TUESDAY. HIGH PRESSURE IS THEN FORECAST TO EXTEND ACROSS THE REGION THROUGH THE END OF THE WEEK. TEMPERATURES WILL START OUT COOL EARLY THIS WEEK...FOLLOWED BY A WARMING TREND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LARGE SCALE MID LEVEL TROUGH OVER THE EASTERN GREAT LAKES THIS MORNING WILL SHIFT EAST INTO NEW ENGLAND AND EASTERN CANADA THROUGH TODAY. AS THIS OCCURS...A SPRAWLING AREA OF SURFACE HIGH PRESSURE OVER THE NORTHERN AND CENTRAL PLAINS WILL MOVE/BUILD SOUTHEAST INTO OUR REGION. MAIN FORECAST DILEMMA TODAY WILL BE FIGURING OUT THE COVERAGE OF CAA STRATOCUMULUS AND HOW FAST THEY WILL EXIT THE AREA. HAVE USED THE RAP MODEL AS A GUIDE TO FIGURE THIS OUT WHICH KEEPS ROUGHLY THE EASTERN TWO THIRDS MOSTLY CLOUDY THROUGH MID MORNING FOLLOWED BY CLEARING SKIES AS SUBSIDENCE...DRYING AND ANTICYCLONIC FLOW INCREASE FROM THE WEST. TEMPERATURES WILL BE BELOW NORMAL FOR THE ARRIVAL OF AUTUMN WITH HIGHS RANGING FROM THE LOWER TO MID 60S. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... SURFACE HIGH PRESSURE WILL SETTLE OVER THE OHIO VALLEY TONIGHT. CLEAR SKIES...LIGHT TO CALM WINDS...AND A DRY AIRMASS WILL MAKE FOR FAVORABLE RADIATIONAL COOLING CONDITIONS. HAVE USED A BLEND OF THE ADJUSTED MAV GUIDANCE AND CONSENSUS RAW 2 METER TEMPERATURES TO TRY TO CAPTURE THE NORMALLY COOL SPOTS. LOWS WILL RANGE FROM THE UPPER 30S IN THOSE COOL SPOTS TO THE MID 40S AT RIDGE TOPS AND NEAR URBAN AREAS. THE HIGH WILL REMAIN IN PLACE ON TUESDAY. SUNNY SKIES AND A MODIFYING AIRMASS WILL ALLOW TEMPERATURES TO WARM INTO THE UPPER 60S TO THE LOWER 70S. A MID LEVEL RIDGE WILL BUILD INTO THE GREAT LAKES AND MIDDLE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. AT THE SAME TIME...SURFACE HIGH PRESSURE WILL EXTEND FROM NEW ENGLAND INTO THE OHIO VALLEY. LITTLE IF ANY CLOUD COVER IS EXPECTED THROUGH THE PERIOD. A WARMING TREND WILL CONTINUE DUE TO A WARMING/MODIFYING AIRMASS. DIURNAL SWINGS OF 25 TO 30 DEGREES WILL BE LIKELY GIVEN THE DRY AIRMASS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... MID/UPPER LEVEL RIDGING WILL REMAIN IN CONTROL THROUGH THE LONG TERM PERIOD. THE MODELS ARE HINTING AT SOME MOISTURE POSSIBLY TRYING TO WORK UP FROM THE SOUTH HEADING INTO THE WEEKEND...BUT WITH RIDGING OVERHEAD...WILL MAINTAIN A DRY FORECAST. TEMPERATURES WILL CONTINUE TO SLOWLY WARM AS THE AIRMASS CONTINUES TO MODIFY/WARM THROUGH THE END OF THE WEEK. TEMPERATURES THROUGH THIS PERIOD SHOULD RUN A FEW DEGREES ABOVE NORMAL. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... AN EXPANSE OF STRATOCUMULUS CLOUDS IS CURRENTLY IN PLACE OVER SOUTHERN MICHIGAN AND NORTHERN OHIO...AND THESE CLOUDS ARE GRADUALLY MAKING PROGRESS TO FILL IN AND MOVE FURTHER SOUTH. THESE CLOUDS ARE GENERALLY IN THE 2500-4000 FOOT RANGE...AND SOME PERIODS OF MVFR CEILINGS WILL BE POSSIBLE...ESPECIALLY AT THE CENTRAL OHIO TAF SITES. NNW WINDS HAVE GENERALLY SUBSIDED TO AROUND 10 KNOTS...BUT GUSTS TO 20 KNOTS WILL STILL BE POSSIBLE FOR ANOTHER FEW HOURS IN CENTRAL OHIO. THESE CLOUDS WILL GRADUALLY DISSIPATE DURING THE MORNING HOURS...AS WINDS SETTLE IN AT AROUND 10 KNOTS THROUGH THE AFTERNOON. WITH HIGH PRESSURE MOVING INTO THE AREA...CLEAR SKIES AND LIGHT WINDS WILL PERSIST INTO THE OVERNIGHT HOURS AND THROUGH TUESDAY. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HICKMAN NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...JGL/HICKMAN AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
906 PM PDT SUN SEP 21 2014 .SYNOPSIS..A DYING FRONT MAY HOLD TOGETHER ENOUGH TO BRING A FEW SHOWERS TO THE COAST MONDAY NIGHT...THEN FURTHER INLAND TUESDAY. A MORE ORGANIZED SYSTEM WILL BRING MORE WIDESPREAD RAIN MIDWEEK...WITH COOL AND SHOWERY WEATHER AFTERWARDS. AFTER A LONG HOT SUMMER...AUTUMN WEATHER WILL BE ARRIVING RIGHT ON TIME. && .EVENING UPDATE...A CLUSTER OF SHOWERS AND THUNDERSTORMS DEVELOPED OVER KLAMATH AND DESCHUTES COUNTIES THIS AFTERNOON...AND HAVE SLOWLY PROGRESSED NORTHWESTWARD INTO EASTERN LANE COUNTY THIS EVENING. IT SEEMS STORMS ARE BEGINNING TO FINALLY TREND WEAKER...BUT ADMITTEDLY...IT SEEMS JUST WHEN WE BEGIN THINKING THIS...A NEW UPDRAFT GOES UP AND TEMPORARILY INVIGORATES AN EXISTING OR NEW STORM. THE PRIMARY THREAT WITH THESE STORMS WILL BE BRIEF HEAVY RAIN AND AN OCCASIONAL CLOUD TO GROUND LIGHTNING STRIKE. THE LATTER HAS DEFINITELY BEEN TRENDING LESS OVER THE LAST HOUR. SUSPECT THESE STORMS WILL WEAKEN FURTHER AS THEY ENTER EASTERN LINN COUNTY. GLOBAL TO HIGH RESOLUTION SHORT TERM MODELS HAVE NOT BEEN PARTICULARLY HELPFUL THIS EVENING. TO VARYING DEGREES THOUGH...LOWER RESOLUTION MODELS DO PRODUCE SOME LIGHT QPF OVER THE CASCADES TONIGHT INTO WEDNESDAY MORNING. THE RAP ALSO INDICATES THE STORMS ACROSS EASTERN LANE COUNTY ARE FORMING IN A LOCALIZED REGION OF NEGATIVE 700 TO 500MB THETA LAPSE RATES. THE RAP SUGGESTS THIS REGION OF NEGATIVE THETA LAPSE RATES WILL GRADUALLY WEAKEN AS IT SHIFTS NORTHWARD ACROSS THE CASCADES TONIGHT AND EVENTUALLY EAST OF THE CREST TOWARDS MORNING. NONETHELESS...BANDS OF ALTOCUMULUS HAVE DEVELOPED OVER THE COAST AND WILLAMETTE VALLEY THIS EVENING. WITH NO DISTINCT INCOMING VORT MAX ON WATER VAPOR THIS EVENING...SUSPECT THIS ALTOCUMULUS WILL STAY RELATIVELY SHALLOW...BUT I AM STILL NERVOUS THAT SOMETHING MIGHT FIRE FURTHER WEST OVER THE FOOTHILLS OR EVEN THE WILLAMETTE VALLEY TONIGHT. WILL CONTINUE TO KEEP PRECIP/THUNDER CHANCES OVER THE CASCADES...AND LEAVE A MENTION OUT OF THE FORECAST FOR THE WILLAMETTE VALLEY...BUT WILL BE MONITORING THE SITUATION CLOSELY. NO CHANGES TO THE REST OF THE FORECAST. WEDNESDAY STILL LOOKS TO BE THE WETTEST DAY OF THE WEEK. /NEUMAN PREVIOUS DISCUSSION BELOW... .SHORT TERM...TONIGHT THROUGH WEDNESDAY...TEMPERATURES ARE GENERALLY DOWN A COUPLE DEGREES VERSUS THIS TIME SATURDAY...AS LIGHT ONSHORE FLOW HAS REPLACED THE OFFSHORE FLOW OF YESTERDAY. THE MOST DRAMATIC TEMPERATURE DROPS HAVE BEEN ALONG THE COAST...WHERE ONSHORE FLOW AND LOW CLOUDS ARE RESULTING IN TEMPS 10-15 DEGREES F COOLER THAN THIS TIME YESTERDAY. THE MARINE LAYER IS IN THE PROCESS OF DEEPENING...AND WILL LIKELY MAKE A SUBSTANTIAL INLAND PUSH OVERNIGHT TONIGHT. BY SUNRISE MONDAY IT IS LIKELY MUCH OF THE FORECAST AREA WILL BE UNDER A BLANKET OF STRATUS. THE LOW CLOUDS WILL TAKE A LITTLE WHILE TO RETREAT TO THE COAST...PROBABLY SOMETIME AROUND MIDDAY OR SHORTLY THEREAFTER. THE INCREASED CLOUD COVER COMBINED WITH 850 MB TEMPS 3-5 DEG C COOLER THAN TODAY SHOULD LEAD TO MAX TEMPS IN THE MID TO UPPER 70S MONDAY AND EVEN THAT MAY BE A LITTLE OPTIMISTIC. THIS WILL BE THE BEGINNING OF A TREND AWAY FROM THE PERSISTENT VERY WARM AND DRY WEATHER THIS SUMMER HAS BROUGHT. AFTER 21 DAYS OF TEMPS 90 DEGREES OR WARMER AT PDX...AND A RECORD 36 DAYS AT OR ABOVE 90 DEGREES IN EUGENE...IT MAY BE SOMEWHAT SAFE TO SAY WE HAVE SEEN THE LAST SUCH HEAT OF THE SEASON. AS WE NEAR THE END OF SEPTEMBER...THE DAYS ARE GETTING SHORTER...AND THE SUN IS GETTING LOWER IN THE SKY. IT BECOMES RAPIDLY MORE DIFFICULT CLIMATOLOGICALLY TO ACHIEVE 90 DEGREES AS WE MOVE TOWARD OCTOBER. AND THIS TRANSITION IS HAPPENING RIGHT ON CUE...AS THE AUTUMNAL EQUINOX IS FAST APPROACHING - 723 PM PDT ON MON SEP 22. MONDAY EVENING A LARGE UPPER LOW AND TROUGH WILL BE APPROACHING THE PAC NW COAST...LIKELY TO BRING A SIGNIFICANT AMOUNT OF RAIN TO OUR DISTRICT AS ITS ASSOCIATED FRONTAL SYSTEM SLOWLY MOVES SLOWLY ONSHORE TUE-WED. 18Z NAM CONTINUES TO SHOW SOME POTENTIAL FOR A DECENT COASTAL JET SETUP ALONG THE COAST TUE EVENING...PERHAPS BRINGING SOME SOUTH WIND GUSTS 40-50 MPH TO THE BEACHES AND HEADLANDS. THIS WOULD BE THE FIRST SUCH EVENT OF THE SEASON. CURRENT FORECAST DOES NOT REFLECT THIS JUST YET...AS THERE IS SOME POTENTIAL FOR ENERGY TO BE SPLITTING AS THE FRONT MOVES ONSHORE. LOWER PRESSURE TO THE NORTH AND LOWER PRESSURE TO THE SOUTH WOULD CUT DOWN ON THE POTENTIAL OF SOUTH TO NORTH GRADIENTS TO DRIVE SUCH WIND GUSTS. WOULD NOT BE SURPRISED TO SEE SOME LOCATIONS SEE 1-3 INCHES OF RAIN OUT OF THIS EVENT TUE THROUGH WED...PARTICULARLY COAST AND COAST RANGE. INLAND AREAS COULD SEE UPWARDS OF 0.50-1.00 INCH DEPENDING ON HOW WAVES TRACK ALONG THE FRONTAL ZONE AS IT LUMBERS ONSHORE. IF RAIN GETS HEAVY...IT COULD BE A CONCERN FOR DEBRIS FLOWS IN SOME OF OUR HARDER HIT FIRE AREAS THESE PAST FEW WEEKS. WILL CONTINUE TO MONITOR THIS POSSIBILITY AND OF COURSE PASS ALONG MORE INFORMATION AS WE LEARN THE SEVERITY OF THESE BURN SCARS. WEAGLE .LONG TERM...AFTER OUR SLOW-MOVING FRONT CLEARS THE REGION WEDNESDAY EVENING...MODELS SHOW DECENT AGREEMENT THAT AN UPPER LEVEL TROUGH WILL SETTLE OVER THE PACIFIC NORTHWEST. THIS WILL MEAN COOL AND UNSETTLED WEATHER WITH PLENTY OF SHOWERS AROUND FOR THE REST OF THE WEEK. IT MAY TAKE UNTIL NEXT WEEKEND FOR TEMPS TO REBOUND BACK TO NORMAL...THOUGH BEYOND FRIDAY MODELS HAVE ALL SORTS OF DIFFERENT IDEAS OF HOW TO HANDLE OUR PATTERN. BEST GUESS IS THAT SOME FLAT RIDGING WILL ATTEMPT TO RETURN BY THE WEEKEND...FOLLOWED BY SOME FRONTAL SYSTEMS ATTEMPTING TO CLIP THE PAC NW BY EARLY NEXT WEEK. THIS BASED MORE ON PATTERN RECOGNITION THAN ANYTHING ELSE...SO CONFIDENCE IN ANY PARTICULAR SOLUTION IS RATHER LOW STARTING NEXT WEEKEND. WEAGLE && .AVIATION...VFR CONDITIONS CONTINUE ACROSS THE INTERIOR UNDER SCT TO BKN CIRRUS AND SOME SMOKE FROM NEARBY WILDLAND FIRES FORMING A SCATTERED LAYER AROUND 5000 FT. STORMS IN EASTERN LANE COUNTY WILL NOT AFFECT EUGENE TERMINAL. A DEEPENING MARINE LAYER WILL PUSH LOW MVFR STRATUS INTO MUCH OF THE VALLEY BY AROUND 12Z MON. AT THE COAST...IFR CIGS HAVE PUSHED BACK ONSHORE AND WILL REMAIN THROUGH LATE MONDAY MORNING BEFORE RISING TO MVFR. KPDX AND APPROACHES...VFR CONDITIONS THROUGH 11Z MON THEN INCREASING CHANCES FOR MVFR CIGS AROUND 1500 FT AS MARINE LAYER DEEPENS AND PUSHES INLAND. MVFR CIGS LIKELY BY 13Z MON...LASTING THROUGH 17Z MON WITH IMPROVEMENT TO VFR CONDITIONS THEREAFTER. BOWEN/CULLEN && .MARINE...SOUTHERLY WINDS CONTINUE ACROSS THE WATERS AND HAVE WEAKENED THIS EVENING AS ANTICIPATED WITH CURRENT GUSTS AROUND 15 KT. UPDATES THIS EVENING INCLUDED SLIGHT ADJUSTMENT OF WINDS BASED ON BEGINNINGS OF THE 00Z NAM. STILL LOOKS LIKE CONDITIONS WILL REMAIN BENIGN THROUGH MONDAY WITH WINDS PICKING UP A BIT MONDAY NIGHT AS A WEAK FRONT MOVES ACROSS THE WATERS. BOTH WINDS AND SEAS INCREASE TUESDAY WITH THE APPROACH OF A STRONGER SYSTEM WITH SEAS BUILDING TO 10-15 FT AND AT LEAST SMALL CRAFT ADVISORY WINDS. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND 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 AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
339 AM CDT MON SEP 22 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 339 AM CDT MON SEP 22 2014 AT 3 AM...A 1026 MB SURFACE HIGH WAS CENTERED OVER EASTERN NEBRASKA. WHILE THE AREA IS UNDER CLEAR SKIES...WE SAW A RAPID INCREASE IN OUR RADAR RETURNS FROM NEAR LA CROSSE TO BETWEEN 22.02Z AND 22.04Z....AND THEY HAVE REMAINED OVER THOSE AREAS THROUGHOUT THE NIGHT. WHILE SOME OF THIS WAS OUR NORMAL ANOMALOUS PROPAGATION OF THE RADAR BEAM THAT WE SEE AS THE NOCTURNAL INVERSION DEVELOPS...THE 30 TO 40 DBZ RETURNS ARE MIGRATORY BIRDS THROUGH THE AREA. WE KNOW THIS BECAUSE THE CORRELATION COEFFICIENTS ARE RUNNING BETWEEN 0.65 AND 0.9. WITH NO PRECIPITATION IN THESE AREAS...THIS MEANS THAT THESE RADAR TARGETS ARE BIOLOGICAL IN NATURE. WE KNOW IT IS MIGRATORY BIRDS BECAUSE OF THE TIME OF YEAR AND THAT THE VAD WIND PROFILE IS SHOWING 30 TO 45 KNOT WINDS BETWEEN 2 AND 15K FEET. TYPICALLY IN THESE SYNOPTIC SITUATIONS WE DO NOT GET THIS MANY WIND LEVELS ALOFT WITHOUT CLOUDS. IN ADDITION THESE WIND SPEEDS ARE RUNNING ABOUT 15 TO 25 KNOTS HIGHER THAN WHAT SHOW UP IN THE SOUNDINGS. THIS ADDITIONAL SPEED IS FROM THE MIGRATORY BIRDS. THE HIGHEST CONCENTRATION OF BIRDS ARE RUNNING BETWEEN 2 AND 8K FEET. BESIDES THE BIRDS TONIGHT...BEEN WATCHING THE SLOW DEVELOPMENT OF FOG. DENSE FOG IS ALREADY REPORTED AT BOSCOBEL AND BLACK RIVER FALLS. WITH LIGHT WINDS /LESS THAN 10 KNOTS/ UP TO 2500 FEET AND OUR WEB CAM ALREADY SHOWING A LAYER OF STRATUS IN THE VALLEYS...WE EXPECT TO SEE A CONTINUAL DEVELOPMENT OF AREAS TO WIDESPREAD FOG. FOLLOWED THE 930 TO 10 AM CLIMATOLOGY WITH THE DISSIPATION OF THIS FOG. TONIGHT...LOOKS TO BE EVEN MORE FAVORABLE FOR THE DEVELOPMENT OF FOG IN THE RIVER VALLEYS AND CENTRAL WISCONSIN WITH LIGHT WINDS UP TO 25K FEET AND CLEAR SKIES. AS A RESULT...WENT WITH WIDESPREAD DENSE FOG FROM 2-3 AM THROUGH 930-10 AM. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 339 AM CDT MON SEP 22 2014 TUESDAY NIGHT...THE 22.00Z MODELS ARE IN GOOD AGREEMENT THAT WEAK 850 MB MOISTURE TRANSPORT WILL DEVELOP ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA AHEAD OF A TROUGH MOVING OUT OF THE PLAINS. BUFKIT SOUNDINGS BETWEEN 06Z AND 12Z ARE SATURATED BETWEEN 5 AND 20K FEET AND THERE IS OMEGA BETWEEN 5 AND 10K FEET. THIS RESULTS IN THE MODELS GENERATING SOME LIGHT RAIN ACROSS THIS AREA. SINCE ALL OF DETERMINISTIC MODELS WERE IN AGREEMENT...ADDED A 15 TO 24 PERCENT CHANCE OF RAIN TO THE FORECAST. FROM WEDNESDAY INTO WEDNESDAY NIGHT...SHOW THAT THE 500 MB SHORT WAVE TROUGH SHEARS APART ACROSS THE AREA. ONE PART MOVES NORTH AND IS ABSORBED BY THE POLAR JET STREAM. MEANWHILE THE SOUTHERN PIECE MOVES SOUTHWEST AND FORMS A CLOSED 500 MB LOW. WHILE THERE IS AGREEMENT THAT THIS WILL OCCUR. THERE ARE DIFFERENCES IN PRECIPITATION. BOTH THE ECMWF AND CANADIAN PRODUCE PRECIPITATION ACROSS THE FORECAST AREA. MEANWHILE THE GFS AND NAM KEEP THIS PRECIPITATION ACROSS SOUTH CENTRAL MINNESOTA AND WESTERN IOWA. SINCE ECMWF SOUNDINGS ARE NOT SHOWING MUCH LIFT CO-LOCATED WITH THE MOISTURE...KEPT THE FORECAST AREA. FOR THE REMAINDER OF THE FORECAST PERIOD /THURSDAY THROUGH SUNDAY/...IT LOOKS DRY AS HIGH PRESSURE REMAINS LOCATED ACROSS THE AREA. 850 MB TEMPERATURES ARE RUNNING 10 TO 14C WHICH IS ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL. THIS RESULT IN TEMPERATURES ABOUT 10 DEGREES WARMER THAN NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1137 PM CDT SUN SEP 21 2014 VALLEY FOG FORMATION CONTINUES TO BE THE MAIN CONCERN. THE TEMP/DEW POINT SPREAD AT 04Z WAS 5F...WHICH IS NOT QUITE OPTIMAL FOR FOG FORMATION...BUT CERTAINLY NOT OUTSIDE THE RANGE WHERE FOG CAN BE DISCOUNTED. THE WINDS AT KLSE ARE LIGHT AND WERE STARTING TO SWING AROUND TO A FAVORABLE UP VALLEY FLOW OF EAST/SOUTHEAST. NO SIGNS OF A HAZE LAYER FORMING OVER THE CITY YET...SO HAVE PUSHED BACK THE TIMING OF THE FOG A LITTLE BIT BUT WITH THE 22.00Z NAM CONTINUING TO SHOW SATURATION OCCURRING AND THE 22.03Z RAP NOW SHOWING THIS AS WELL...STILL FEEL FAIRLY CONFIDENT THAT FOG WILL DEVELOP. ONCE THIS DISSIPATES FRIDAY MORNING...VFR CONDITIONS WITH LIGHT WINDS AS THE SURFACE HIGHS DRIFTS OVER THE AREA. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1137 PM CDT SUN SEP 21 2014 .SHORT TERM...(TONIGHT) ISSUED AT 200 PM CDT SUN SEP 21 2014 THE VIGOROUS UPPER LEVEL SHORTWAVE TROUGH THAT BROUGHT THE SHOWERS/STORMS TO THE REGION LAST NIGHT WAS TRACKING ACROSS THE EASTERN GREAT LAKES EARLY THIS AFTERNOON. SFC FRONT EXTENDED WESTWARD FROM SYSTEMS/S LOW...BACK ACROSS WI. ADD IN FAVORABLE LOW LEVEL LAPSE RATES AND SPOTTY/SCATTERED SHOWERS CONTINUED ACROSS CENTRAL-EASTERN WI. THE BOUNDARY WILL SLIP SOUTH BY THE EVENING WITH HIGH PRESSURE BUILDING INTO IA/MO OVERNIGHT. A LOT OF DIURNAL ELEMENTS TO THE CURRENT CLOUD MASS ACROSS THE REGION...AND WITH THE LOSS OF DAYTIME HEATING AND SINKING AIR ASSOCIATED WITH THE HIGH...EXPECT THESE CLOUDS TO CLEAR QUICKLY THIS EVENING. COULD SEE SOME FOG IN THE RIVER VALLEYS FOR MONDAY MORNING. .LONG TERM...(MONDAY THROUGH SUNDAY) ISSUED AT 200 PM CDT SUN SEP 21 2014 GFS/ECMWF/GEM ALL IN GOOD AGREEMENT WITH BUILDING A STRONG UPPER LEVEL RIDGE ACROSS THE CENTRAL U.S. FOR MUCH OF THIS WEEK. ALL WANT TO SLIP A SHORTWAVE TROUGH FROM THE WEST COAST INTO THE CENTRAL/NORTHERN PLAINS TUE...THEN TRIES TO LIFT IT EAST/NORTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. GEM/GFS SPLIT THE UPPER LEVEL ENERGY...TAKING A PIECE NORTH OF THE AREA...AND HANGING A SOUTHERN PIECE OVER THE PLAINS. ASSOCIATED SFC FRONT ISN/T OVERLY CONVERGENT IN THE LATEST SOLUTIONS. SOME LOW LEVEL MOISTURE TRANSPORT COULD HELP FUEL SOME SHOWERS. THE GFS/GEM AND EVEN THE NAM WOULD HOLD ANY PCPN ACROSS MN...PUSHING INTO SOUTHERN CANADA. SOME SHOWER CHANCES OVER IA AND WEST INTO THE PLAINS. PREVIOUS EC RUN FAVORED KEEPING THE SHORTWAVE TOGETHER...THUS STRONGER AND MORE CONVERGENT TOWARD THE SFC WITH THE FRONT. HOWEVER...THE 12Z RUN IS NOW MORE INLINE WITH THE SPLITTING SOLUTION. WILL LEAN THIS WAY. THE BIT OF SOUTHERN ENERGY COULD RETROGRADE TO THE WEST WHILE THE UPPER RIDGE CONTINUES TO ASSERT ITSELF. A SFC HIGH SETS UP SHOP OVER THE EASTERN GREAT LAKES...PUTTING THIS REGION UNDER SOUTHERLY FLOW. TEMPS WILL WARM...WITH 850 MB TEMPS CLIMBING FROM AROUND 8 C ON MONDAY TO 16 C FRI. NAEFS 850 MB TEMP ANOMALIES POINTING TO +2 ACROSS SOUTHERN CANADA FOR THU-SAT...BUT 0-1 LOCALLY. STILL...LOOKS LIKE ABOVE NORMAL TEMPERATURES TOWARD THE END OF THE WEEK...AND COULD BE A VERY MILD OKTOBERFEST FOR THOSE IN THE LA CROSSE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1137 PM CDT SUN SEP 21 2014 VALLEY FOG FORMATION CONTINUES TO BE THE MAIN CONCERN. THE TEMP/DEW POINT SPREAD AT 04Z WAS 5F...WHICH IS NOT QUITE OPTIMAL FOR FOG FORMATION...BUT CERTAINLY NOT OUTSIDE THE RANGE WHERE FOG CAN BE DISCOUNTED. THE WINDS AT KLSE ARE LIGHT AND WERE STARTING TO SWING AROUND TO A FAVORABLE UP VALLEY FLOW OF EAST/SOUTHEAST. NO SIGNS OF A HAZE LAYER FORMING OVER THE CITY YET...SO HAVE PUSHED BACK THE TIMING OF THE FOG A LITTLE BIT BUT WITH THE 22.00Z NAM CONTINUING TO SHOW SATURATION OCCURRING AND THE 22.03Z RAP NOW SHOWING THIS AS WELL...STILL FEEL FAIRLY CONFIDENT THAT FOG WILL DEVELOP. ONCE THIS DISSIPATES FRIDAY MORNING...VFR CONDITIONS WITH LIGHT WINDS AS THE SURFACE HIGHS DRIFTS OVER THE AREA. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RIECK LONG TERM....RIECK AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1154 PM MDT SUN SEP 21 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 330 PM MDT SUN SEP 21 2014 AFTERNOON SATELLITE IMAGES SHOW WELL-DEFINED LOW PRESSURE AREA LIFTING NORTH/NORTHEAST ACROSS THE GREAT BASIN...WITH ARM OF MOISTURE ASSOCIATED WITH WEAK SHORTWAVE EXTENDING TO ITS N AND E ADVECTING INTO THE INTERMOUNTAIN WEST. SHOWERS WERE OBSERVED AT KCAG EARLIER THIS AFTERNOON...AND KCYS/KGJX 88D RETURNS SUGGEST THIS MOISTURE HAS MADE IT INTO THE SIERRA MADRES AND ADJACENT WRN FOOTHILL LOCATIONS. 20Z SFC ANALYSIS SHOWS 1026MB ACROSS THE DAKOTAS AND NEBRASKA WITH RETURN FLOW ALONG THE FRONT RANGE AND A WELL DEFINED SFC TROF BANKED UP ALONG THE EAST SLOPES OF THE SNOWY RANGE. LLVL CONVERGENCE ALONG THIS SFC TROF HAS COMBINED WITH 250+ J/KG OF SBCAPE AS ANALYZED FROM SPC MESOANALYSIS TO SPARK A COUPLE OF POCKETS OF DEEPER CONVECTION IN THE VICINITY OF CENTENNIAL/ WOODS LANDING/ALBANY OVR THE PAST FEW HOURS. LOW CENTER WILL REACH IDAHO BY LATE TONIGHT...WITH ARM OF MOISTURE ADVECTION CONTINUING FROM SW TO NE INTO THE CWFA. HIGH CLOUDS HAVE ALREADY BEEN ON THE INCREASE ACROSS THE AREA...BUT SHOULD SEE THESE LOWER AND THICKEN OVERNIGHT. ASCENT ASSOCIATED WITH THE UPPER-LOW WILL INCREASE TONIGHT...SO WILL SEE SHOWERS AND STORMS INCREASE ESPECIALLY ALONG AND WEST OF THE LARAMIE RANGE AS WELL. HAVE ALSO ADDED SOME FOG TO THE SRN LARAMIE RANGE PER LATEST HRRR OUTPUT. LIGHTNING WAS EVIDENT ACROSS SW COLORADO LAST NIGHT...SO IT MAKES SENSE TO KEEP IT TONIGHT UP HERE TONIGHT. 12Z MODEL OUTPUT HAS TRENDED SLOWER IN SPREADING RAIN CHANCES OUT ONTO THE ERN PLAINS...WHICH WILL LIKELY NOW HOLD OFF NOW UNTIL SOMETIME MONDAY MORNING. UPPER LOW WOBBLES THRU THE COWBOY STATE ON MONDAY...WHICH WILL EFFECTIVELY SHARPEN AND ENHANCE AFTERNOON CONVECTION ALONG THE PREFRONTAL SFC TROF/PACIFIC FRONT. BEST CONVECTIVE CHANCES ON MONDAY WILL BE TIED CLOSELY TO THE LOCATION OF THIS TROF...WHICH WILL BE WEST OF THE LARAMIE RANGE IN THE MORNING BEFORE PUSHING EAST OF THE LARAMIE RANGE MONDAY. PROGD INSTABILITY PARAMETERS LOOK FAIRLY MEAGER...WITH SBCAPES TOPPING OUT AROUND 500 J/KG. HOWEVER...WITH THE PROXIMITY OF THE UPPER WAVE COMBINED WITH DAYTIME DESTABILIZATION...WOULD EXPECT PERHAPS SOME MORE ORGANIZED CONVECTION FOR LOCATIONS EAST OF THE MOUNTAINS. SHOWER AND THUNDERSTORM CHANCES WILL DECREASE SOME FROM WEST TO EAST MONDAY NIGHT. UPPER-LOW WILL DEPART DURING THE DAY ON TUESDAY...BRINGING PRECIPITATION CHANCES TO AN END FROM WEST TO EAST. OTHERWISE... TUESDAY WILL LIKELY TURN A BIT BREEZY AND WINDS TURN WEST BEHIND THE DEPARTING PREFRONTAL SFC TROF/PACIFIC FRONT. WIND GUSTS OF 20 TO 35 MPH CAN BE EXPECTED DURING THE AFTERNOON. MONDAY WILL BE THE COOLEST DAY OF THE WEEK AS CLOUD COVER PROHIBITS THE AMOUNT OF INSOLATION. EVEN SO...EXPECT HIGH TEMPERATURES IN THE 70S/LOW 80S. HIGHS WILL WARM ABOUT 5 DEGREES OR SO ON TUESDAY...YIELDING MID 70S TO MID 80S. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 330 PM MDT SUN SEP 21 2014 NOT A WHOLE LOT OF CHANGE IN THE MODEL GUIDANCE THROUGH THE FIRST HALF OF THE EXTENDED PERIOD. SUBSTANTIAL RIDGE BUILDS OVER THE INTERMOUNTAIN WEST ON WED AND THIS WILL CAUSE TEMPS TO RISE TO AROUND 10 DEGREES ABOVE NORMAL ACROSS THE CWA. WINDS WILL BE LIGHT ON WED WITH WEAK SFC GRADIENTS AND FLOW ALOFT. NOT MUCH CHANGE FOR THURS EXCEPT THAT SOUTH-TO-SOUTHEAST WINDS WILL BE BREEZY DURING THE AFTN ACROSS THE PLAINS DUE TO PRESSURE FALLS OVER MONTANA. THE MODELS CONTINUE TO EXHIBIT DIFFERENCES AS WE HEAD INTO NEXT WEEKEND. THE GFS IS YET AGAIN THE MOST PROGRESSIVE WITH THE WESTERN UPPER TROUGH...MOVING ITS AXIS TO NEAR UTAH BY SAT. WIDESPREAD PRECIP IS PROGGED BEHIND THE COLD FRONTAL PASSAGE ON SAT NIGHT...SOME OF WHICH COULD BE SNOW OVER THE MTNS. THE ECMWF SHOWS A CUTOFF OVER CALIFORNIA ON SAT WHICH WOULD SIGNIFICANTLY DELAY A COOLDOWN AND IS A MUCH DRIER SOLN. WITH SUCH BIG DIFFERENCES ALMOST A WEEK OUT DECIDED TO INCREASE CLOUD COVER ON SAT BUT KEEP ONLY SLIGHT CHANCE POPS ON SAT NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING) ISSUED AT 1153 PM MDT SUN SEP 21 2014 CURRENT RADAR SHOWS SHOWERS AND T-STORMS FOCUSED MAINLY OVER THE COLORADO MOUNTAINS AT 06Z...WITH A BREAK IN THE ACTION OVER SOUTHEAST WYOMING. EXPECT THE ACTIVITY OVER COLORADO TO STEADILY MOVE TO THE NORTHEAST AND OVER THE MOUNTAINS OF SOUTHEAST WYO AFTER 08Z WITH DRY CONDITIONS EAST OF THE LARAMIE RANGE. VFR CONDITIONS SHOULD PREVAIL AS THIS ACTIVITY IS EXPECTED TO REMAIN WEAK. MODEL GUIDANCE CONTINUES TO SHOW SCT IFR STRATUS OVER KCYS AFTER 08Z IN SOUTH-SOUTHEAST UPSLOPE FLOW. IN ADDITION...WINDS AT MOST SITES WILL INCREASE OVERNIGHT...WITH SPEEDS OF 10 TO 15 KTS LIKELY THROUGH THE MORNING. GUSTS OF 20 TO 30 KTS WILL THEN BE POSSIBLE THROUGH MONDAY AFTERNOON...WITH T-STORM COVERAGE TO INCREASE ACROSS THE EASTERN PLAINS AND CONTINUING THRU THE EARLY EVENING. && .FIRE WEATHER... ISSUED AT 330 PM MDT SUN SEP 21 2014 SHOWER AND THUNDERSTORM CHANCES TO INCREASE TONIGHT AND MONDAY. THIS WILL KEEP FIRE WEATHER CONCERNS MINIMAL THROUGH AT LEAST TUESDAY. AN AREA OF LOW PRESSURE WILL BRING RELATIVELY GOOD CHANCES OF WETTING RAINS TO THE DISTRICTS TONIGHT THROUGH MONDAY EVENING. DO NOT ANTICIPATE SIGNIFICANT RAINFALL TOTALS...HOWEVER A FEW TENTHS OF AN INCH WILL BE A POSSIBILITY IN THE HEAVIEST SHOWERS/STORMS. DRIER AND WARMER CONDITIONS WILL RETURN TUE-FRI. EVEN SO MINIMUM RELATIVE HUMIDITIES ARE STILL ONLY EXPECTED TO BOTTOM OUT NEAR 20 PERCENT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...HAHN LONG TERM...FINCH AVIATION...RJM FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
851 AM MDT MON SEP 22 2014 .UPDATE... ISSUED AT 841 AM MDT MON SEP 22 2014 ONLY MINOR CHANGES NEEDED AT THIS UPDATE TIME. FIRST BATCH OF SHOWERS NOW MOVING ACROSS THE NORTHEAST PLAINS WITH GENERALLY LIGHT RAINFALL AMOUNTS AND NO LIGHTNING BEING REPORTED. SECONDARY BATCH NOW OVER NORTHWEST COLORADO WITH QUITE A BIT OF LIGHTNING ASSOCIATED WITH UPPER TROF AND 60KT JET STREAK. THIS WILL ALL PUSH ACROSS NORTHERN COLORADO THIS AFTERNOON AND EARLY EVENING END WITH STRONGER THUNDERSTORMS POSSIBLE. STORMS SHOULD DIMINISH RAPIDLY THIS EVENING AS SUBSIDENCE KICKS IN BEHIND TROF. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 452 AM MDT MON SEP 22 2014 TROUGH PASSING OVER COLORADO TODAY. MODELS ARE PRETTY GOOD WITH THE TIMING OF THE TROUGH THOUGH THERE ARE SOME DISAGREEMENTS AS TO THE PLACEMENT OF CONVECTION. NAM COMPARES WITH THE CURRENT PATTERN PRETTY MISERABLY...GFS HAS TOO LITTLE THIS MORNING AND TOO MUCH THIS EVENING. HRRR LOOKS PRETTY REASONABLE BRINGING THE UPSTREAM BATCH OF SHOWERS OVER DENVER AT MIDDAY...THEN GENERATING ISOLATED THUNDERSTORMS OVER THE MOUNTAINS AND NORTHERN PART OF THE PLAINS IN THE MID TO LATE AFTERNOON AS THERE IS SLIGHT COOLING ALOFT BEHIND THE TROUGH. WILL GENERALLY GO WITH THIS IDEA...THOUGH I HAVE SOME RESERVATIONS ABOUT MOISTURE AVAILABILITY. PLAINS REMAIN COOL AND DRY AND WHILE SOUTHERLY WINDS ARE INCREASING THERE IS NOT BETTER MOISTURE AT THE SURFACE UNTIL YOU GET TO TEXAS. SO THE MOISTURE WILL HAVE TO BE COMING WITH THE SHOWER BAND. THERE WILL BE SOME OF THIS GOING ON...BUT MODEL FORECAST MOISTURE ON THE PLAINS DURING THE DAY LOOKS OVERDONE. MOISTURE UNCERTAINTY IMPACTS THE PROSPECTS FOR STRONG STORMS. WIND PROFILE IN THE MODELS IS GOOD FOR SUPERCELLS ALONG AND BEHIND THE TROUGH AXIS ON THE PLAINS THIS AFTERNOON...NAM HAS CAPES OF 1000-1500 J/KG WHICH WOULD PRESENT A DECENT THREAT OF SEVERE WEATHER. BUT THIS IS WITH DEW POINTS IN THE MID 50S WHICH LOOKS PRETTY UNLIKELY...ESPECIALLY IN THE AIR BEHIND THE TROUGH WHERE ANY REMAINING SURFACE MOISTURE SHOULD BE MIXING OUT. THERE ALSO MAY BE MORE OF A WIND SHIFT THAN THE MODELS ARE SHOWING AS A DENVER CYCLONE BOUNDARY THAT GETS PICKED UP WITH THE TROUGH AXIS AND MOVES EAST TURNING INTO A DRYLINE SEEMS QUITE POSSIBLE. NAM/GFS MOS DEW POINTS OF 45-50 ONLY GIVE CAPES AROUND 500 J/KG...AND I THINK THIS IS MORE LIKELY. GIVEN THE WIND PROFILE AND FAST MOVING STORMS...MAYBE STILL A SMALL WIND THREAT. FOR TONIGHT THERE MAY BE SOME SHALLOW CONVECTION IN LINGERING LIFT IN THE NORTHERN PART OF THE AREA FOR A WHILE...BUT SUBSIDENCE AND CLEARING SHOULD BE COVERING THE AREA BY MORNING. COULD BE A MOUNTAIN WAVE SETUP WITH SOME WARMING ALOFT BY 12Z...THOUGH SPEEDS ARE MARGINAL SO PROBABLY JUST A BIT GUSTIER THAN WOULD OTHERWISE BE EXPECTED. WITH JUST A LITTLE COOLING ALOFT...SNOW LEVEL SHOULD STAY ABOVE TIMBERLINE. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 452 AM MDT MON SEP 22 2014 TUESDAY AND TUESDAY NIGHT...THE STORM SYSTEM WILL PASS TO THE NORTH AND EAST WITH A NORTHWESTERLY FLOW ALOFT OVER THE REGION. ENOUGH MID LEVEL INSTBY AND MOISTURE WILL BE PRESENT FOR SOME LINGERING SHOWERS/TSTMS IN THE HIGH COUNTRY AND FAR NORTHEAST PLAINS THROUGH EARLY TUESDAY EVENING. WEDNESDAY THROUGH THURSDAY...AN UPPER LEVEL RIDGE WILL BUILD OVER THE GREAT BASIN/CENTRAL ROCKIES WITH A DRY AND SUBSIDENT NORTHERLY FLOW ALOFT OVER NORTHEAST COLORADO. TEMPERATURES WILL CLIMB BACK INTO THE MID TO UPPER 80S. BY FRIDAY...THE RIDGE AXIS IS PROGGED TO SHIFT TO THE EAST WITH A WEAK SLY FLOW ALOFT OVER THE STATE. SUBTROPICAL MOISTURE WILL START TO ADVECT BACK INTO COLORADO. SOME POPS GET INTRODUCED BACK INTO THE HIGH COUNTRY BY FRIDAY AFTN...WITH A BETTER CHANCE OF SHOWERS/TSTMS FOR THE REST OF NORTHEAST AND NORTH CENTRAL COLORADO OVER THE WEEKEND AHEAD OF THE NEXT UPPER TROUGH WHICH IS EXPECTED TO MOVE ACROSS NRN PORTIONS OF && .AVIATION...(FOR THE TAFS THROUGH 18Z TUESDAY MORNING) ISSUED AT 841 AM MDT MON SEP 22 2014 AREA OF LIGHT RAIN NOW SPREADING NORTHEAST ACROSS APA/DEN SO HAVE ADJUSTED LATEST TAFS FOR THESE TRENDS. SHOWERS WILL DIMINISH BETWEEN 16-17Z WITH A BREAK IN THE PRECIP BEFORE NOON. EXPECT SCATTERED THUNDERSTORMS TO DEVELOP THIS AFTERNOON AS UPPER TROF MOVES OVER THE AREA ESPECIALLY GIVEN CURRENT THUNDERSTORMS NOW OVER WESTERN CO. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ENTREKIN SHORT TERM...GIMMESTAD LONG TERM...COOPER AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
452 AM MDT MON SEP 22 2014 .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 452 AM MDT MON SEP 22 2014 TROUGH PASSING OVER COLORADO TODAY. MODELS ARE PRETTY GOOD WITH THE TIMING OF THE TROUGH THOUGH THERE ARE SOME DISAGREEMENTS AS TO THE PLACEMENT OF CONVECTION. NAM COMPARES WITH THE CURRENT PATTERN PRETTY MISERABLY...GFS HAS TOO LITTLE THIS MORNING AND TOO MUCH THIS EVENING. HRRR LOOKS PRETTY REASONABLE BRINGING THE UPSTREAM BATCH OF SHOWERS OVER DENVER AT MIDDAY...THEN GENERATING ISOLATED THUNDERSTORMS OVER THE MOUNTAINS AND NORTHERN PART OF THE PLAINS IN THE MID TO LATE AFTERNOON AS THERE IS SLIGHT COOLING ALOFT BEHIND THE TROUGH. WILL GENERALLY GO WITH THIS IDEA...THOUGH I HAVE SOME RESERVATIONS ABOUT MOISTURE AVAILABILITY. PLAINS REMAIN COOL AND DRY AND WHILE SOUTHERLY WINDS ARE INCREASING THERE IS NOT BETTER MOISTURE AT THE SURFACE UNTIL YOU GET TO TEXAS. SO THE MOISTURE WILL HAVE TO BE COMING WITH THE SHOWER BAND. THERE WILL BE SOME OF THIS GOING ON...BUT MODEL FORECAST MOISTURE ON THE PLAINS DURING THE DAY LOOKS OVERDONE. MOISTURE UNCERTAINTY IMPACTS THE PROSPECTS FOR STRONG STORMS. WIND PROFILE IN THE MODELS IS GOOD FOR SUPERCELLS ALONG AND BEHIND THE TROUGH AXIS ON THE PLAINS THIS AFTERNOON...NAM HAS CAPES OF 1000-1500 J/KG WHICH WOULD PRESENT A DECENT THREAT OF SEVERE WEATHER. BUT THIS IS WITH DEW POINTS IN THE MID 50S WHICH LOOKS PRETTY UNLIKELY...ESPECIALLY IN THE AIR BEHIND THE TROUGH WHERE ANY REMAINING SURFACE MOISTURE SHOULD BE MIXING OUT. THERE ALSO MAY BE MORE OF A WIND SHIFT THAN THE MODELS ARE SHOWING AS A DENVER CYCLONE BOUNDARY THAT GETS PICKED UP WITH THE TROUGH AXIS AND MOVES EAST TURNING INTO A DRYLINE SEEMS QUITE POSSIBLE. NAM/GFS MOS DEW POINTS OF 45-50 ONLY GIVE CAPES AROUND 500 J/KG...AND I THINK THIS IS MORE LIKELY. GIVEN THE WIND PROFILE AND FAST MOVING STORMS...MAYBE STILL A SMALL WIND THREAT. FOR TONIGHT THERE MAY BE SOME SHALLOW CONVECTION IN LINGERING LIFT IN THE NORTHERN PART OF THE AREA FOR A WHILE...BUT SUBSIDENCE AND CLEARING SHOULD BE COVERING THE AREA BY MORNING. COULD BE A MOUNTAIN WAVE SETUP WITH SOME WARMING ALOFT BY 12Z...THOUGH SPEEDS ARE MARGINAL SO PROBABLY JUST A BIT GUSTIER THAN WOULD OTHERWISE BE EXPECTED. WITH JUST A LITTLE COOLING ALOFT...SNOW LEVEL SHOULD STAY ABOVE TIMBERLINE. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 452 AM MDT MON SEP 22 2014 TUESDAY AND TUESDAY NIGHT...THE STORM SYSTEM WLL PASS TO THE NORTH AND EAST WITH A NORTHWESTERLY FLOW ALOFT OVER THE REGION. ENOUGH MID LEVEL INSTBY AND MOISTURE WILL BE PRESENT FOR SOME LINGERING SHOWERS/TSTMS IN THE HIGH COUNTRY AND FAR NORTHEAST PLAINS THROUGH EARLY TUESDAY EVENING. WEDNESDAY THROUGH THURSDAY...AN UPPER LEVEL RIDGE WILL BUILD OVER THE GREAT BASIN/CENTRAL ROCKIES WITH A DRY AND SUBSIDENT NORTHERLY FLOW ALOFT OVER NORTHEAST COLORADO. TEMPERATURES WILL CLIMB BACK INTO THE MID TO UPPER 80S. BY FRIDAY...THE RIDGE AXIS IS PROGGED TO SHIFT TO THE EAST WITH A WEAK SLY FLOW ALOFT OVER THE STATE. SUBTROPICAL MOISTURE WILL START TO ADVECT BACK INTO COLORADO. SOME POPS GET INTRODUCED BACK INTO THE HIGH COUNTRY BY FRIDAY AFTN...WITH A BETTER CHANCE OF SHOWERS/TSTMS FOR THE REST OF NORTHEAST AND NORTH CENTRAL COLORADO OVER THE WEEKEND AHEAD OF THE NEXT UPPER TROUGH WHICH IS EXPECTED TO MOVE ACROSS NRN PORTIONS OF CA/NV BY SUNDAY. && .AVIATION...(FOR THE TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 452 AM MDT MON SEP 22 2014 VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT...THOUGH INSTRUMENT APPROACHES TO KDEN MAY BE NEEDED AT TIMES AS SHOWERS MOVE THROUGH. MOST LIKELY TIME FOR THIS IS BETWEEN 16Z AND 22Z. SOUTH WINDS THIS MORNING WILL LIKELY SHIFT TO NORTH DURING THE MIDDLE OF THE DAY AS A DENVER CYCLONE STRENGTHENS AND THEN SHIFTS EAST. THIS PATTERN COULD BE DISRUPTED WITH WIND SHIFTS DUE TO SHOWER ACTIVITY HOWEVER. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GIMMESTAD LONG TERM...COOPER AVIATION...GIMMESTAD
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
959 AM EDT MON SEP 22 2014 .UPDATE... THE WEAKENING FRONTAL BOUNDARY OVER CENTRAL FLORIDA WILL DISSIPATE AS ANOTHER COLD FRONT OVER GEORGIA AND ALABAMA DRIFTS SOUTHEAST OVER THE REGION. AMPLE MOISTURE IN PLACE WILL PROVIDE AN ENVIRONMENT CONDUCIVE FOR SCATTERED TO NUMEROUS SHOWERS AND STORMS LATER THIS MORNING AND AFTERNOON. LATEST WATER VAPOR IMAGERY SHOWS A LOT OF MOISTURE OVER CENTRAL FLORIDA AND THE 12Z SOUNDING IS INDICATING CLOSE TO 2 INCHES OF PRECIPITABLE WATER WITH A VERY MOIST COLUMN BELOW 500 MB. THERE HAS ONLY BEEN A FEW ISOLATED SHOWERS ACROSS THE COASTLINE THIS MORNING. MOST OF THE CONVECTION HAS REMAINED WELL OFF SHORE...BUT IS EXPECTED TO PUSH OVER THE COASTLINE LATER THIS MORNING INTO THE AFTERNOON. FOR THE REST OF TODAY WE WILL CONTINUE TO SEE SCATTERED TO NUMEROUS SHOWERS AND A FEW THUNDERSTORMS DEVELOP IN THE DEEPER MOISTURE AND MOVE EAST NORTHEAST AFFECTING MOST AREAS THROUGHOUT CENTRAL FLORIDA. THE LATEST HRRR COMPOSITE RADAR FORECAST HAS THE LARGEST MASS OF PRECIPITATION MOVING INLAND JUST SOUTH OF TAMPA BAY AROUND 17-18Z. THIS CONVECTION SHOULD SHIFT EASTWARD DURING THE AFTERNOON AS THE LOW LEVEL SOUTH SOUTHWEST FLOW PUSHES THEM INLAND. GRIDS LOOK ON TRACK FOR NOW. && .AVIATION... WILL KEEP VFR CONDITIONS AT ALL TAF LOCATIONS FOR TODAY. A FEW ISOLATED SHOWERS HAVE MADE THEIR WAY ONSHORE NEAR SRQ THIS MORNING BUT CONDITIONS REMAINED VFR. WILL KEEP VCSH IN THE MORNING AND VCTS DURING THE AFTERNOON HOURS. ANY MVFR TO IFR WOULD BE MOST LIKELY WITH THE TSRA LATER IN THE DAY. CALM TO LIGHT VARIABLE WINDS BECOME SOUTH TO SW LATER THIS MORNING. && .MARINE... A COLD FRONT OVER THE SOUTHEAST U.S. WILL MOVE SOUTH INTO THE NORTHERN GULF WATERS TONIGHT AND THEN STALL ACROSS THE CENTRAL/SOUTHERN WATERS TUESDAY THROUGH FRIDAY. WINDS AND SEAS WILL INCREASE SOME AS HIGH PRESSURE BUILDS IN FROM THE NORTH DURING THE WEEK WITH PERIODS OF EXERCISE CAUTION CRITERIA POSSIBLE. THE MAIN HAZARDS WILL CONTINUE TO BE HIGHER WINDS AND SEAS IN THE VICINITY OF SCATTERED TO NUMEROUS THUNDERSTORMS THROUGH THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 88 74 87 73 / 60 40 60 30 FMY 89 74 88 72 / 60 40 50 40 GIF 88 72 88 72 / 60 40 60 30 SRQ 87 73 86 73 / 60 40 60 40 BKV 88 68 88 68 / 60 40 60 30 SPG 86 75 86 75 / 60 40 60 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/AVIATION...74/WYNN MARINE...69/CLOSE DECISION SUPPORT...18/FLEMING Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1045 AM CDT Mon Sep 22 2014 .UPDATE... ISSUED AT 1045 AM CDT MON SEP 22 2014 The forecast generally looks on track today with just very minor updates to sky grids over eastern IL where few to scattered cumulus clouds from I-57 east, especially near IN/IL border per NAM and RUC curule but still mostly sunny skies. Highs in the upper 60s to around 70F with north winds 5-10 mph. 1028 mb high pressure over nw IL and northern MO late this morning to settle over central IL tonight and continue fair weather with temperatures a bit below normal. Temps currently in the upper 50s and lower 60s should climb about another 10 degrees for highs in the upper 60s to around 70F this afternoon. Coolest readings over east central IL. && .SHORT TERM...(Today) ISSUED AT 341 AM CDT MON SEP 22 2014 High pressure centered over eastern Nebraska will move east into the area today. This will bring clear skies, dry weather and light winds. Even with lots of sunshine today, highs are only expected to reach into the upper 60s to around 70 degrees. GFS MOS guidance looks several degrees too warm, while the NAM is too cool. && .LONG TERM...(Tonight through Sunday) ISSUED AT 341 AM CDT MON SEP 22 2014 An extended period of quiet weather throughout the remainder of the forecast with high pressure building into and remaining in control of the Midwest. Surface ridge dominating much of the eastern half of the CONUS and keeping the weather quiet and fair, with slowly warming temps through the work week. Weak flow under the sfc high becomes more southerly on Tuesday as the ridge axis shifts slightly eastward. Warming trend continues with the thermal ridging over the desert SW slowly advecting into the center of the country and max temps are just above normals by Thursday. A weak trof brings some precip to the Plains Wednesday, but the ridge remains in place and dry air eroding the activity before impacting Central Illinois. In the extended, the GFS pushes some minor precip into the extreme SE with an oddly evolving upper pattern beyond day 6. ECMWF remaining dry and energy aloft without significant flow seeming to retrograde somewhat under a larger scale ridge. Keeping the forecast dry for next weekend until the models become a little more cohesive with their solutions under the pattern shift. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) ISSUED AT 605 AM CDT MON SEP 22 2014 VFR conditions will continue at all sites next 24 hours. With high pressure moving into the area, skies will be clear next 24 hours with light and variable winds. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...AUTEN LONG TERM...HJS AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1026 AM CDT MON SEP 22 2014 .UPDATE... ISSUED AT 1026 AM CDT MON SEP 22 2014 UPDATE TO THE FORECAST TO ACCOUNT FOR THE BAND OF LIGHT RAIN SHOWERS CURRENTLY ACROSS NORTHEAST COLORADO...THIS BAND IS LIFTING TO THE NORTHEAST AND WILL IMPACT SOUTHWEST NEBRASKA AND THE EASTERN PANHANDLE OVER THE NEXT COUPLE HOURS. PREVIOUS FORECAST HAD THIS HANDLED WELL...JUST MINOR REVISIONS WERE IMPLEMENTED. THE 22.14Z RUC13 SEEMS TO BE HANDLING THE CURRENT SITUATION WELL AND IS BEING BLENDED WITH THE PREVIOUS FORECAST WHICH SUGGESTS A SLIGHT DELAY IN QPF OF AN HOUR OR TWO ACROSS SOUTHWEST NEBRASKA. IN ADDITION...INSTABILITY IS SOMEWHAT LACKING OVER THIS AREA...THUS SHOWERS SHOULD PREVAIL RATHER THAN STORMS THIS MORNING...BUT THE MODEL INDICATES A GRADUAL INCREASE WITH THE INSTABILITY PARAMETERS INTO THE AFTERNOON...THUNDER IS POSSIBLE THEN. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 401 AM CDT MON SEP 22 2014 TODAY AND TONIGHT...A DEEPENING SFC TROF WILL ADVANCE SOUTHEAST INTO WRN NEB TODAY AND TONIGHT. SFC WINDS ARE EXPECTED TO INCREASE TO 15 TO 25 MPH WITH GUSTS TO 35 MPH ACROSS NWRN ZONES. WINDS RELAX A BIT TONIGHT BUT REMAIN STRONG OFF THE SFC. THE LATEST MODEL CONSENSUS SUGGESTS CLUSTERS OF SHOWERS AND THUNDERSTORMS SHOULD BE UNDERWAY BY 21Z THIS AFTN AS AN UPPER LOW ACROSS IDAHO ADVANCES EAST TOWARD AND INTO WRN SD TODAY AND TONIGHT. THE SEVERE WEATHER POTENTIAL LOOKS LOW TODAY AND TONIGHT AS THE BETTER INSTABILITY REMAINS OVER ERN COLO. THE MODEL CONSENSUS SUGGESTS 1/4 TO 1/2 INCH OF RAIN TODAY AND TONIGHT ACROSS THE FCST AREA BUT THERE IS CERTAINLY THE POTENTIAL FOR MORE GIVEN PWS INCREASING TO 1.33 INCHES WHICH IS 200 PERCENT OF NORMAL. THE NAM INDICATED HIGHER VALUES. THE ONGOING CLOUD COVER ACROSS WRN NEB IS EXPECTED TO INCREASE AND EXPAND EAST TODAY. SOME CLEARING MAY DEVELOP IN THE WEST LATE TONIGHT. GIVEN THE HIGH MOISTURE AVAILABLE POPS ARE LIKELY SOUTH AND EAST TONIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 401 AM CDT MON SEP 22 2014 THE PRIMARY FORECAST CONCERN WILL BE THUNDERSTORM CHANCES TUESDAY...THEN WITH TEMPERATURES AND RAIN CHANCES WITH A RETROGRADING UPPER LEVEL SYSTEM THROUGHOUT THIS WEEK. TUESDAY...THE UPPER LEVEL LOW WILL BE PUSHING OUT OF THE ROCKY MOUNTAINS AND INTO THE NORTHERN PLAINS. THE MODELS ARE IN GOOD AGREEMENT WITH THE UPPER LOW CENTER MOVING ACROSS SOUTH DAKOTA THROUGH THE DAY...WITH VARIOUS WEAK SHORTWAVE IMPULSES MOVING AROUND THE SYSTEM. SHOWERS AND POTENTIALLY A FEW ISOLATED THUNDERSTORMS SHOULD BE EXITING THE FORECAST AREA TO THE EAST DURING THE MORNING HOURS. BY AFTERNOON...A SURFACE TROUGH WILL MAKE ITS WAY ACROSS THE PANHANDLE AND INTO WESTERN NEBRASKA. FORECAST SOUNDINGS SHOW LOCATIONS GENERALLY WEST OF HIGHWAY 83 WILL MIX OUT AND WITH STEEP LOW LEVEL AND MID LEVEL LAPSE RATES...CAPE VALUES INCREASE TO 1000-2000 J/KG BY LATE AFTERNOON AND WITH THE STRONG WARMING...SURFACE BASED CONVECTION IS LIKELY. THERE IS SOME DISCREPANCIES BETWEEN MODELS IN TERMS OF DEEP LAYER SHEAR...AS THE GFS IS MUCH STRONGER...SUGGESTING IN EXCESS OF 40KTS...WHILE THE NAM IS 20 TO 30KTS. EVEN WITH THE LOWER SHEAR...IT SHOULD BE SUFFICIENT FOR AT LEAST A FEW STRONGER STORMS LATER TUESDAY AFTERNOON. AREAS TO THE EAST WILL SEE COOLER HIGHS...IN THE UPPER 60S AND LOW 70S DUE TO THE PRECIPITATION EARLIER IN THE DAY AND ARE LOOKING TO STAY VERY CAPPED. THESE AREAS WILL STILL SEE STORMS MOVE IN DURING THE EVENING AND OVERNIGHT HOURS...BUT THEY SHOULD BECOME ELEVATED QUICKLY AND WITH A LACK OF INSTABILITY WOULD EXPECT THUNDER TO DECREASE...BUT THERE WILL BE AT LEAST A WEAK LOW LEVEL JET THAT COULD CONTINUE TO FEED THE STORMS THROUGH THE NIGHT AS THEY MOVE EAST. AT 12Z WEDNESDAY MORNING...THE MODELS HAVE MOVED THE UPPER LOW CENTER OVER SOUTHEAST SOUTH DAKOTA AND NORTHEAST NEBRASKA...AND WITH THE UPWARD FORCING SHIFTING TO THE EAST...PRECIPITATION SHOULD BE CLOSE TO...IF NOT COMPLETELY FINISHED LOCALLY. FAIRLY STRONG SUBSIDENCE BUILDS IN ACROSS THE FORECAST AREA THROUGH THE DAY WEDNESDAY BEHIND THE UPPER LEVEL SYSTEM LEADS TO A DRY FORECAST. WARMER AIR WILL BE ADVECTING INTO THE AREA DURING THE DAY AND WITH THE DRY AIR IN PLACE AND PLENTY OF SUNSHINE...STRONG WARMING IS EXPECTED WITH HIGHS IN THE 80S FOR THE WESTERN TWO-THIRDS OF THE FORECAST AREA. WITH THE UPPER LOW REMAINING OVER EASTERN NEBRASKA...THE EASTERN PARTS OF THE FORECAST AREA MAY SEE SOME RESIDUAL CLOUD COVER AND WITH COOLER TEMPERATURES ALOFT...WILL SEE COOLER TEMPERATURES WITH HIGHS LOOKING TO BE IN THE MID TO UPPER 70S. BEYOND WEDNESDAY THERE BEGINS TO BE SLIGHT DIVERGENCE IN THE MODEL SOLUTIONS IN TERMS OF THE UPPER LEVEL PATTERN. WHAT IS IN GOOD AGREEMENT IS A DEEP LONGWAVE TROUGH MOVING INTO THE WESTERN CONUS...WITH RIDGING BUILDING AHEAD OF IT INTO THE NORTHERN PLAINS. WHAT IS STARTING TO GET PROBLEMATIC IS THE CURRENT SYSTEM GETS STUCK UNDER THE LARGE RIDGE WHICH SPANS INTO THE EASTERN PART OF THE COUNTRY AND STARTS TO RETROGRADE. THE DISCREPANCIES LIE WITH HOW FAR WEST IT WILL MAKE IT. THE RIDGE TO THE WEST WILL KEEP SOUTHERLY FLOW IN THE LOWER LEVELS...KEEPING LOW LEVEL MOISTURE ACROSS THE FORECAST AREA WITH DEWPOINTS REMAINING IN THE UPPER 50S AND 60S...WHILE WEAK AND MINI SHORTWAVES MAY MOVE ACROSS THE FORECAST AREA AT TIMES LATER IN THE WEEK. THESE SMALL IMPULSES OF ENERGY AREN/T LOOKING TO GENERATE ENOUGH LIFT AT THIS POINT TO PROVIDE A NEED FOR RAIN IN THE FORECAST SO WILL KEEP A DRY FORECAST AT THIS TIME. WHAT THIS WILL MEAN IS LIKELY COOLER TEMPERATURES FOR LATE IN THE WEEK AS THE WARMER AIR WILL BE KEPT TO THE WEST AND NORTH OF THE LOCAL AREA DUE TO THE INFLUENCE OF THE UPPER LEVEL SYSTEM. THEN LOOKING INTO THE WEEKEND...OUT OF THE LONGWAVE TROUGH MOVING ONTO THE WEST COAST...A LOW WILL CLOSE OFF AND SLOWLY MIGRATE TOWARDS THE EAST. THERE IS DIFFERENCES WITH THE SPEED AS THE OPERATIONAL GFS IS FASTER THAN THE ECMWF AS WELL AS THE GFS ENSEMBLE MEAN. THE FASTER SOLUTION WOULD BRING CHANCES FOR SHOWERS AND THUNDERSTORMS BY SUNDAY AFTERNOON...WHILE THE SLOWER WOULD KEEP THINGS DRY INTO MONDAY. WILL BE KEEPING A CLOSE EYE ON THIS SYSTEM AS TIME GETS CLOSER TO GET A BETTER HANDLE ON THE FORECAST FOR THESE PERIODS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 624 AM CDT MON SEP 22 2014 AREAS OF SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS WRN NEB 18Z- 20Z AND MOVE EAST NORTHEAST THROUGH NCNTL NEB LATE THIS AFTN AND TONIGHT. THIS ACTIVITY IS EXPECTED TO EXITING THE FCST AREA TO THE EAST 06Z- 12Z TUESDAY MORNING. MVFR CIGS MAY DEVELOP ALONG AND NEAR HIGHWAY 61 06Z-09Z TUESDAY MORNING IN THE WAKE OF THE TSTMS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JACOBS SHORT TERM...CDC LONG TERM...BROOKS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
652 AM EDT MON SEP 22 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS MORNING BEFORE STALLING OFFSHORE. AN UPPER LEVEL LOW WILL BRING A CHANCE FOR SOME SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND TONIGHT. COOLER AND DRIER WEATHER IS EXPECTED ON TUESDAY. THE STALLED COLD FRONT OFFSHORE WILL WAVER BACK TOWARDS THE COAST DURING THE MIDDLE AND LATTER PART OF THE UPCOMING WEEK...BRINGING GOOD CHANCES FOR RAIN AND BELOW NORMAL TEMPERATURES. A WARMING AND DRYING TREND IS EXPECTED DURING THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 640 AM MONDAY...UPDATES THIS MORNING FOCUS ON THE CLUSTER OF SHOWERS FALLING OUT OF A MID-LEVEL CLOUD DECK ACROSS THE PEE DEE REGION OF SOUTH CAROLINA. 07Z HRRR BRINGS IT STEADILY EASTWARD OVER THE NEXT FEW HOURS WITH VERY LIGHT RAINFALL AMOUNTS EXPECTED. A NEW CLUSTER OF CONVECTION IS INDICATED TO DEVELOP IN THE SANTEE RIVER/CHARLESTON VICINITY BETWEEN 3-5 PM THIS AFTERNOON AHEAD OF THE UPPER LEVEL DISTURBANCE. THIS WILL PROBABLY BE UPRIGHT CONVECTION DEVELOPING ALONG AND JUST NORTH OF THE SURFACE FRONT...WITH UPPER LEVEL WINDS POTENTIALLY BLOWING LIGHT RAIN ANOTHER 30-50 MILES NORTH OF THE STORMS. NO SIGNIFICANT CHANGES HAVE BEEN MADE TO TEMPS OR WINDS. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... A POTENTIALLY INTERESTING FORECAST IS IN STORE FOR THE EASTERN CAROLINAS OVER THE NEXT 24 HOURS. A COLD FRONT CURRENTLY EXTENDING ALONG THE EASTERN EDGE OF THE NC PIEDMONT INTO CENTRAL SOUTH CAROLINA SHOULD PUSH OFF THE COAST BY MID MORNING WITH NORTH-NORTHEAST SURFACE WINDS ALLOWING A DRY CANADIAN AIRMASS TO BUILD SOUTHWARD. THIS IS A SHALLOW AIRMASS CHANGE...WITH WIND DIRECTIONS REMAINING WEST OR WEST-SOUTHWESTERLY AT AND ABOVE THE 850 MB LEVEL. THE FRONT WILL PUSH OUT JUST BEYOND THE GULF STREAM TONIGHT WITH STRENGTHENING LOW-LEVEL NORTHEAST FLOW DEVELOPING AS SURFACE PRESSURES RISE ACROSS THE MID-ATLANTIC REGION WITH HIGH PRESSURE BUILDING EASTWARD FROM THE MIDWEST. UP AT 500 MB AN UPPER DISTURBANCE DESCENDING INTO THE SOUTHERN APPALACHIANS THIS AFTERNOON IS EXPECTED TO CUT OFF TONIGHT OVER WESTERN SOUTH CAROLINA. THERE ARE A COUPLE CONCERNS WITH THE FORECAST WITHOUT A CLEAR ANSWER AT THIS EARLY HOUR. THE FIRST IS HOW MUCH MID-LEVEL CLOUD COVER HANGS AROUND TODAY AND WHAT IMPACT DOES IT HAVE ON TEMPERATURES? SATELLITE IMAGERY REVEALS A NARROW BAND OF THICK CLOUDS OVER CENTRAL AL/GA...MATCHING UP QUITE WELL WITH ANALYZED 700 MB RH MODEL FIELDS. BOTH THE 00Z NAM AND GFS ADVECT THIS MOISTURE ACROSS EASTERN SOUTH CAROLINA TODAY...LEADING ME TO BELIEVE THERE WILL BE TOO MUCH CLOUD COVER TO LET TEMPERATURES RISE ABOVE THE LOWER 80S. IN FACT MORE SUNSHINE UP IN THE LUMBERTON/ELIZABETHTOWN AREA WILL PROBABLY BALANCE OUT THE OVERALL COOLER AIRMASS TO PRODUCE LOWER 80S ACROSS THE ENTIRE FORECAST AREA TODAY. THE SECOND CONCERN IS WITH THE UPPER LOW CUTTING OFF TO OUR WEST TONIGHT HOW MUCH OVERRUNNING RAIN DEVELOPS? ISENTROPIC LIFT IS ANTICIPATED TO REMAIN WELL ABOVE THE FRONTAL INVERSION...PROBABLY NOT BEGINNING IN EARNEST UNTIL THE 310K THETA SURFACE WHICH WILL BE UP NEAR 600 MB. THE 00Z GFS IS THE MOST AGGRESSIVE WITH BRINGING RAIN ACROSS EASTERN SC LATE THIS AFTERNOON INTO TONIGHT. GIVEN THE RELATIVELY WEAK WIND FIELDS PROGGED TO EXIST BELOW 600 MB IT IS HARD TO BELIEVE THERE WILL BE SIGNIFICANT ADVECTION OF CONVECTIVE SHOWERS ONSHORE EITHER. MY HIGHEST POP FORECASTS ARE LIMITED TO COASTAL SOUTH CAROLINA IN THE 40-50 PERCENT RANGE...WITH 15-30 PERCENT CHANCES ELSEWHERE. CLOUDS WILL INHIBIT RADIATIONAL COOLING TONIGHT...HOWEVER INCREASING NORTHEAST WINDS WILL ADVECT IN SIGNIFICANTLY COOLER AIR LEADING TO LOWS FALLING INTO THE UPPER 50S FROM ELIZABETHTOWN THROUGH DILLON AND DARLINGTON. LOWER 60S ARE EXPECTED ALONG THE COAST...EXCEPT FOR SOME MID 60S ALONG THE COAST NEAR SOUTHPORT AND GEORGETOWN. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...THE FIRST FULL OF DAY OF FALL ON TUESDAY BEGINS WITH COLD FRONT POSITIONED JUST OFFSHORE...AS LARGE CANADIAN HIGH PRESSURE CENTERED OVER THE OH VLY RIDGES DOWN INTO THE CAROLINAS. ALTHOUGH THIS FRONT WILL BE OFFSHORE...THERE IS SOME UNCERTAINTY INTO JUST HOW FAR FROM THE COAST IT WILL GET BEFORE STALLING. THE UPPER ENERGY DRIVING THIS FRONT WILL WEAKEN AND BECOME BROAD OVERHEAD...STALLING AS A GREAT LAKES AREA RIDGE BLOSSOMS FROM THE SOUTHWEST. THIS CREATES A DIFFICULT FORECAST BECAUSE...ALTHOUGH MOST OF THE AREA WILL BE DRY TUESDAY...THE BROAD LOW OVERHEAD WILL INTERACT WITH THE SURFACE BOUNDARY TO CAUSE WIDESPREAD RAIN SHOWERS LURKING JUST OFF THE COAST...POSSIBLY ALONG THE COAST. WINDS THROUGH THE LOWEST 600MB OF THE COLUMN WILL VEER TO THE E/NE...LIKELY DRIVING THE BOUNDARY /COASTAL TROUGH/ BACK TOWARDS SHORE. THIS CREATES INCREASING SHOWER CHANCES ON WEDNESDAY...HIGHEST POP NEAR THE COAST. ATTM IT LOOKS LIKE THE HEAVIEST RAIN WILL REMAIN JUST OFFSHORE WITH ONLY LIGHT RAIN ANTICIPATED WITHIN THE CWA. HOWEVER...THIS WILL NEED TO BE MONITORED CLOSELY AS A VERY SHARP GRADIENT WILL EXIST BETWEEN HEAVY RAIN AND JUST LIGHT SHOWERS. TEMPS BOTH TUESDAY AND WEDNESDAY WILL BE BELOW NORMAL FOR LATE SEPTEMBER...WITH HIGHS IN THE MID/UPR 70S BOTH DAYS. HOWEVER...TUESDAY WILL HAVE NOTICEABLY MORE SUNSHINE THAN WEDNESDAY. LOWS TUESDAY NIGHT WILL FEATURE WIDESPREAD 50S...WITH SOME LOW 50S POSSIBLE WEST OF I-95. MINS WEDNESDAY NIGHT WILL BE SEVERAL DEGREES WARMER THANKS TO INCREASING ONSHORE FLOW. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...VERY UNSETTLED THE FIRST HALF OF THE PERIOD AS THE PATTERN TAKES ON MORE OF A WINTER-LIKE FEEL...BUT IMPROVEMENTS ARE EXPECTED FOR THE WEEKEND. DIFFUSE UPPER LOW OVERHEAD THURSDAY WILL WORK IN TANDEM WITH A COASTAL TROUGH JUST OFFSHORE TO PRODUCE WIDESPREAD CLOUDS AND RAIN THURSDAY/FRIDAY. STILL UNCERTAINTY EXISTING IN EXACTLY HOW THE PATTERN WILL EVOLVE LATE-WEEK...AS THERE WILL BE A VERY SHARP GRADIENT BETWEEN EXTREMELY HIGH PWATS LURKING JUST OFFSHORE...AND MUCH MORE TYPICAL PWATS TOWARDS I-95. THE DIFFERENCE IS DUE TO THE COASTAL TROUGH WHICH WILL BE SLOWLY ADVECTING WESTWARD ON DEEP EASTERLY FLOW...PUSHING THE BETTER RAIN CHANCES TOWARDS THE COAST. WPC GRAPHICS SHOW THIS GRADIENT WELL...WITH ABOUT 4 INCHES OF QPF CENTERED JUST OFF THE CAPE FEAR COAST...BUT LESS THAN ONE-QUARTER INCH IN THE WESTERN ZONES. THE ECMWF IS ONE OF THE MORE PESSIMISTIC MODELS...BUT IS FAVORED BY WPC...AND THE TREND HAS BEEN FOR A MORE UNSETTLED THU/FRI PERIOD. WILL BUMP POP TO MDT CHC FOR LATE WEEK AND CONTINUE WITH HIGHS BELOW CLIMO BUT LOWS SLIGHTLY ABOVE. THE COASTAL TROUGH WILL BEGIN TO ERODE SATURDAY AS RIDGING FINALLY DISPLACES THE UPPER TROUGH...BECOMING MORE PRONOUNCED AT THE END OF THE PERIOD. THIS SUGGESTS DRYING FOR THE WEEKEND...ESPECIALLY AT THE MID-LEVELS...AND RAIN CHANCES WILL TAKE A DECIDEDLY DOWNWARD TURN DURING THE WKND...ALTHOUGH IT MAY BE SLOW. IMPROVING CONDITIONS WILL ALSO ALLOW TEMPS TO RECOVER TO SEASONABLE NORMS. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 12Z...A COLD FRONT IS POISED OVER THE NORTHERN PORTION OF THE CWA. THE IS MOSTLY MID CLOUD ASSOCIATED WITH IT...HOWEVER SOME LIGHT SHOWERS WILL DEVELOP ALONG THE FRONT THIS MORNING...MAINLY AFFECTING FLO AND LBT WITH AT WORST INTERMITTENT MVFR CONDITIONS. LATER TODAY HEAVIER ACTIVITY IS EXPECTED TO DEVELOP OVER THE EXTREME SOUTHEAST PORTION OF THE CWA...POSSIBLY AFFECTING THE MYRTLES. THERE COULD BE SOME INTERMITTENT IFR CONDITIONS THERE...WITH POSSIBLE THUNDER. WINDS POST FRONTAL WILL SHIFT TO THE NORTHEAST...WITH A MID CLOUD CEILING LINGERING THROUGH THE AFTERNOON HOURS. LIGHT WINDS TONIGHT WITH LITTLE OR NO FOG EXPECTED. EXTENDED OUTLOOK...VFR THROUGH WEDNESDAY. RAIN DEVELOPING THURSDAY AFTERNOON INTO FRIDAY WITH POSSIBLE MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 640 AM MONDAY...THE FRONT IS RUNNING ABOUT TWO HOURS SLOWER THAN EARLIER MODELS INDICATED. IT HAS CROSSED INTERSTATE 95 AND SHOULD BE AT THE BEACHES AROUND 9 AM. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... A COLD FRONT CURRENTLY EXTENDING ACROSS THE INTERIOR CAROLINAS WILL MOVE EAST AND OFF THE COAST LATER THIS MORNING. WESTERLY WINDS WILL TURN NORTH-NORTHEASTERLY BEHIND THE FRONT...WITH A SUBSTANTIAL INCREASE IN WIND SPEEDS EXPECTED TONIGHT AS HIGH PRESSURE OVER THE MIDWEST MOVES INTO THE MID- ATLANTIC STATES. SEAS CURRENTLY RANGING FROM 3-5 FEET WILL DIMINISH THIS AFTERNOON IN THE LIGHTER WINDS BEHIND THE FRONT...BUT SHOULD BUILD AGAIN OVERNIGHT IN RESPONSE TO THE INCREASING NE WIND. WE COULD BE NEAR SMALL CRAFT ADVISORY THRESHOLDS BY DAYBREAK TUESDAY. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...COLD FRONT STALLED JUST OFFSHORE TUESDAY MORNING WILL REMAIN NEARLY STATIONARY THROUGH MID-WEEK AS HIGH PRESSURE RIDGES DOWN THE COAST. THIS PRODUCES A PINCHED GRADIENT OVER THE WATERS...AND PERSISTENT NE WINDS OF 15-25 KTS...WITH LITTLE FLUCTUATION...BOTH TUESDAY AND WEDNESDAY. THESE GUSTY NE WINDS WILL DRIVE WAVE HEIGHTS UP TO 4-6 FT FT TUESDAY...AND REMAIN THERE ON WEDNESDAY...WITH A NE WIND WAVE THE DOMINANT GROUP. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED DURING MUCH OF THE PERIOD...BUT HOISTING THE HEADLINE WILL WAIT UNTIL MORE CERTAINTY ABOUT THE TIMING CAN BE DETERMINED. ONCE THE SCA IS ISSUED...IT WILL LIKELY REMAIN IN EFFECT FOR QUITE SOME TIME. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...THE EXTENDED WILL BE MUCH LIKE THE SHORT TERM...AS A STAGNANT PATTERN KEEPS A COASTAL TROUGH JUST OFFSHORE AND A HIGH PRESSURE WEDGE INLAND. THIS PRODUCES A PROLONGED PERIOD OF NE WINDS DUE TO A PINCHED GRADIENT...AND WINDS OF 15-25 KTS WILL BE COMMON LATE WEEK. THIS EXTENDED PERIOD OF GUSTY NE WINDS WILL KEEP WAVE HEIGHTS AT 4-6 FT PRETTY MUCH THE ENTIRE FORECAST PERIOD...AND A SMALL CRAFT ADVISORY WHICH WILL LIKELY BE HOISTED EARLIER IN THE WEEK...WILL BE NEEDED FOR MOST...IF NOT ALL...OF THE LONG TERM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...43 MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
645 AM EDT MON SEP 22 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS MORNING BEFORE STALLING OFFSHORE. AN UPPER LEVEL LOW WILL BRING A CHANCE FOR SOME SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND TONIGHT. COOLER AND DRIER WEATHER IS EXPECTED ON TUESDAY. THE STALLED COLD FRONT OFFSHORE WILL WAVER BACK TOWARDS THE COAST DURING THE MIDDLE AND LATTER PART OF THE UPCOMING WEEK...BRINGING GOOD CHANCES FOR RAIN AND BELOW NORMAL TEMPERATURES. A WARMING AND DRYING TREND IS EXPECTED DURING THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 640 AM MONDAY...UPDATES THIS MORNING FOCUS ON THE CLUSTER OF SHOWERS FALLING OUT OF A MID-LEVEL CLOUD DECK ACROSS THE PEE DEE REGION OF SOUTH CAROLINA. 07Z HRRR BRINGS IT STEADILY EASTWARD OVER THE NEXT FEW HOURS WITH VERY LIGHT RAINFALL AMOUNTS EXPECTED. A NEW CLUSTER OF CONVECTION IS INDICATED TO DEVELOP IN THE SANTEE RIVER/CHARLESTON VICINITY BETWEEN 3-5 PM THIS AFTERNOON AHEAD OF THE UPPER LEVEL DISTURBANCE. THIS WILL PROBABLY BE UPRIGHT CONVECTION DEVELOPING ALONG AND JUST NORTH OF THE SURFACE FRONT...WITH UPPER LEVEL WINDS POTENTIALLY BLOWING LIGHT RAIN ANOTHER 30-50 MILES NORTH OF THE STORMS. NO SIGNIFICANT CHANGES HAVE BEEN MADE TO TEMPS OR WINDS. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... A POTENTIALLY INTERESTING FORECAST IS IN STORE FOR THE EASTERN CAROLINAS OVER THE NEXT 24 HOURS. A COLD FRONT CURRENTLY EXTENDING ALONG THE EASTERN EDGE OF THE NC PIEDMONT INTO CENTRAL SOUTH CAROLINA SHOULD PUSH OFF THE COAST BY MID MORNING WITH NORTH-NORTHEAST SURFACE WINDS ALLOWING A DRY CANADIAN AIRMASS TO BUILD SOUTHWARD. THIS IS A SHALLOW AIRMASS CHANGE...WITH WIND DIRECTIONS REMAINING WEST OR WEST-SOUTHWESTERLY AT AND ABOVE THE 850 MB LEVEL. THE FRONT WILL PUSH OUT JUST BEYOND THE GULF STREAM TONIGHT WITH STRENGTHENING LOW-LEVEL NORTHEAST FLOW DEVELOPING AS SURFACE PRESSURES RISE ACROSS THE MID-ATLANTIC REGION WITH HIGH PRESSURE BUILDING EASTWARD FROM THE MIDWEST. UP AT 500 MB AN UPPER DISTURBANCE DESCENDING INTO THE SOUTHERN APPALACHIANS THIS AFTERNOON IS EXPECTED TO CUT OFF TONIGHT OVER WESTERN SOUTH CAROLINA. THERE ARE A COUPLE CONCERNS WITH THE FORECAST WITHOUT A CLEAR ANSWER AT THIS EARLY HOUR. THE FIRST IS HOW MUCH MID-LEVEL CLOUD COVER HANGS AROUND TODAY AND WHAT IMPACT DOES IT HAVE ON TEMPERATURES? SATELLITE IMAGERY REVEALS A NARROW BAND OF THICK CLOUDS OVER CENTRAL AL/GA...MATCHING UP QUITE WELL WITH ANALYZED 700 MB RH MODEL FIELDS. BOTH THE 00Z NAM AND GFS ADVECT THIS MOISTURE ACROSS EASTERN SOUTH CAROLINA TODAY...LEADING ME TO BELIEVE THERE WILL BE TOO MUCH CLOUD COVER TO LET TEMPERATURES RISE ABOVE THE LOWER 80S. IN FACT MORE SUNSHINE UP IN THE LUMBERTON/ELIZABETHTOWN AREA WILL PROBABLY BALANCE OUT THE OVERALL COOLER AIRMASS TO PRODUCE LOWER 80S ACROSS THE ENTIRE FORECAST AREA TODAY. THE SECOND CONCERN IS WITH THE UPPER LOW CUTTING OFF TO OUR WEST TONIGHT HOW MUCH OVERRUNNING RAIN DEVELOPS? ISENTROPIC LIFT IS ANTICIPATED TO REMAIN WELL ABOVE THE FRONTAL INVERSION...PROBABLY NOT BEGINNING IN EARNEST UNTIL THE 310K THETA SURFACE WHICH WILL BE UP NEAR 600 MB. THE 00Z GFS IS THE MOST AGGRESSIVE WITH BRINGING RAIN ACROSS EASTERN SC LATE THIS AFTERNOON INTO TONIGHT. GIVEN THE RELATIVELY WEAK WIND FIELDS PROGGED TO EXIST BELOW 600 MB IT IS HARD TO BELIEVE THERE WILL BE SIGNIFICANT ADVECTION OF CONVECTIVE SHOWERS ONSHORE EITHER. MY HIGHEST POP FORECASTS ARE LIMITED TO COASTAL SOUTH CAROLINA IN THE 40-50 PERCENT RANGE...WITH 15-30 PERCENT CHANCES ELSEWHERE. CLOUDS WILL INHIBIT RADIATIONAL COOLING TONIGHT...HOWEVER INCREASING NORTHEAST WINDS WILL ADVECT IN SIGNIFICANTLY COOLER AIR LEADING TO LOWS FALLING INTO THE UPPER 50S FROM ELIZABETHTOWN THROUGH DILLON AND DARLINGTON. LOWER 60S ARE EXPECTED ALONG THE COAST...EXCEPT FOR SOME MID 60S ALONG THE COAST NEAR SOUTHPORT AND GEORGETOWN. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...THE FIRST FULL OF DAY OF FALL ON TUESDAY BEGINS WITH COLD FRONT POSITIONED JUST OFFSHORE...AS LARGE CANADIAN HIGH PRESSURE CENTERED OVER THE OH VLY RIDGES DOWN INTO THE CAROLINAS. ALTHOUGH THIS FRONT WILL BE OFFSHORE...THERE IS SOME UNCERTAINTY INTO JUST HOW FAR FROM THE COAST IT WILL GET BEFORE STALLING. THE UPPER ENERGY DRIVING THIS FRONT WILL WEAKEN AND BECOME BROAD OVERHEAD...STALLING AS A GREAT LAKES AREA RIDGE BLOSSOMS FROM THE SOUTHWEST. THIS CREATES A DIFFICULT FORECAST BECAUSE...ALTHOUGH MOST OF THE AREA WILL BE DRY TUESDAY...THE BROAD LOW OVERHEAD WILL INTERACT WITH THE SURFACE BOUNDARY TO CAUSE WIDESPREAD RAIN SHOWERS LURKING JUST OFF THE COAST...POSSIBLY ALONG THE COAST. WINDS THROUGH THE LOWEST 600MB OF THE COLUMN WILL VEER TO THE E/NE...LIKELY DRIVING THE BOUNDARY /COASTAL TROUGH/ BACK TOWARDS SHORE. THIS CREATES INCREASING SHOWER CHANCES ON WEDNESDAY...HIGHEST POP NEAR THE COAST. ATTM IT LOOKS LIKE THE HEAVIEST RAIN WILL REMAIN JUST OFFSHORE WITH ONLY LIGHT RAIN ANTICIPATED WITHIN THE CWA. HOWEVER...THIS WILL NEED TO BE MONITORED CLOSELY AS A VERY SHARP GRADIENT WILL EXIST BETWEEN HEAVY RAIN AND JUST LIGHT SHOWERS. TEMPS BOTH TUESDAY AND WEDNESDAY WILL BE BELOW NORMAL FOR LATE SEPTEMBER...WITH HIGHS IN THE MID/UPR 70S BOTH DAYS. HOWEVER...TUESDAY WILL HAVE NOTICEABLY MORE SUNSHINE THAN WEDNESDAY. LOWS TUESDAY NIGHT WILL FEATURE WIDESPREAD 50S...WITH SOME LOW 50S POSSIBLE WEST OF I-95. MINS WEDNESDAY NIGHT WILL BE SEVERAL DEGREES WARMER THANKS TO INCREASING ONSHORE FLOW. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...VERY UNSETTLED THE FIRST HALF OF THE PERIOD AS THE PATTERN TAKES ON MORE OF A WINTER-LIKE FEEL...BUT IMPROVEMENTS ARE EXPECTED FOR THE WEEKEND. DIFFUSE UPPER LOW OVERHEAD THURSDAY WILL WORK IN TANDEM WITH A COASTAL TROUGH JUST OFFSHORE TO PRODUCE WIDESPREAD CLOUDS AND RAIN THURSDAY/FRIDAY. STILL UNCERTAINTY EXISTING IN EXACTLY HOW THE PATTERN WILL EVOLVE LATE-WEEK...AS THERE WILL BE A VERY SHARP GRADIENT BETWEEN EXTREMELY HIGH PWATS LURKING JUST OFFSHORE...AND MUCH MORE TYPICAL PWATS TOWARDS I-95. THE DIFFERENCE IS DUE TO THE COASTAL TROUGH WHICH WILL BE SLOWLY ADVECTING WESTWARD ON DEEP EASTERLY FLOW...PUSHING THE BETTER RAIN CHANCES TOWARDS THE COAST. WPC GRAPHICS SHOW THIS GRADIENT WELL...WITH ABOUT 4 INCHES OF QPF CENTERED JUST OFF THE CAPE FEAR COAST...BUT LESS THAN ONE-QUARTER INCH IN THE WESTERN ZONES. THE ECMWF IS ONE OF THE MORE PESSIMISTIC MODELS...BUT IS FAVORED BY WPC...AND THE TREND HAS BEEN FOR A MORE UNSETTLED THU/FRI PERIOD. WILL BUMP POP TO MDT CHC FOR LATE WEEK AND CONTINUE WITH HIGHS BELOW CLIMO BUT LOWS SLIGHTLY ABOVE. THE COASTAL TROUGH WILL BEGIN TO ERODE SATURDAY AS RIDGING FINALLY DISPLACES THE UPPER TROUGH...BECOMING MORE PRONOUNCED AT THE END OF THE PERIOD. THIS SUGGESTS DRYING FOR THE WEEKEND...ESPECIALLY AT THE MID-LEVELS...AND RAIN CHANCES WILL TAKE A DECIDEDLY DOWNWARD TURN DURING THE WKND...ALTHOUGH IT MAY BE SLOW. IMPROVING CONDITIONS WILL ALSO ALLOW TEMPS TO RECOVER TO SEASONABLE NORMS. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... AS OF 06Z...HIGH CONFIDENCE OF VFR EARLY THIS MORNING AS WINDS REMAIN ELEVATED AS A COLD FRONT MOVES THROUGH. WINDS WILL SHIFT TO THE NW 06-07Z AT KFLO/KLBT AND 09-10Z AT THE COASTAL TERMINALS. CIGS SHOULD REMAIN AT OR ABOVE 4K. ISOLATED LIGHT SHOWERS POSSIBLE WITH FROPA THUS WILL CONTINUE TO MENTION VCSH. SHOWERS SHOULD DISSIPATE AFTER SUNRISE AS VFR CONTINUES. THICKNESS PATTERNS SUGGEST ACTUAL COLD AIR WILL LAG QUITE AWAYS BEHIND THE FRONT. A SLUGGISH PRESSURE PATTERN MAY CAUSE WIND DIRECTIONS TO BECOME VARIABLE AT THE COASTAL TERMINALS BY LATE MORNING OR IN THE AFTERNOON. WEAK LOW LEVEL CONVERGENCE AT THE COASTAL TERMINALS ALONG WITH INCREASING PVA MAY CAUSE MORE SIGNIFICANT SHOWER DEVELOPMENT IN THE AFTERNOON. STILL APPEARS VFR WILL CONTINUE AT THE COASTAL TERMINALS IN THE AFTERNOON. DURING THE EVENING WINDS WILL BECOME N-NE TERMINAL-WIDE AS HIGH PRESSURE BUILDS IN. EXTENDED OUTLOOK...VFR THROUGH WEDNESDAY. RAIN DEVELOPING THURSDAY AFTERNOON INTO FRIDAY WITH POSSIBLE MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 640 AM MONDAY...THE FRONT IS RUNNING ABOUT TWO HOURS SLOWER THAN EARLIER MODELS INDICATED. IT HAS CROSSED INTERSTATE 95 AND SHOULD BE AT THE BEACHES AROUND 9 AM. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... A COLD FRONT CURRENTLY EXTENDING ACROSS THE INTERIOR CAROLINAS WILL MOVE EAST AND OFF THE COAST LATER THIS MORNING. WESTERLY WINDS WILL TURN NORTH-NORTHEASTERLY BEHIND THE FRONT...WITH A SUBSTANTIAL INCREASE IN WIND SPEEDS EXPECTED TONIGHT AS HIGH PRESSURE OVER THE MIDWEST MOVES INTO THE MID- ATLANTIC STATES. SEAS CURRENTLY RANGING FROM 3-5 FEET WILL DIMINISH THIS AFTERNOON IN THE LIGHTER WINDS BEHIND THE FRONT...BUT SHOULD BUILD AGAIN OVERNIGHT IN RESPONSE TO THE INCREASING NE WIND. WE COULD BE NEAR SMALL CRAFT ADVISORY THRESHOLDS BY DAYBREAK TUESDAY. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...COLD FRONT STALLED JUST OFFSHORE TUESDAY MORNING WILL REMAIN NEARLY STATIONARY THROUGH MID-WEEK AS HIGH PRESSURE RIDGES DOWN THE COAST. THIS PRODUCES A PINCHED GRADIENT OVER THE WATERS...AND PERSISTENT NE WINDS OF 15-25 KTS...WITH LITTLE FLUCTUATION...BOTH TUESDAY AND WEDNESDAY. THESE GUSTY NE WINDS WILL DRIVE WAVE HEIGHTS UP TO 4-6 FT FT TUESDAY...AND REMAIN THERE ON WEDNESDAY...WITH A NE WIND WAVE THE DOMINANT GROUP. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED DURING MUCH OF THE PERIOD...BUT HOISTING THE HEADLINE WILL WAIT UNTIL MORE CERTAINTY ABOUT THE TIMING CAN BE DETERMINED. ONCE THE SCA IS ISSUED...IT WILL LIKELY REMAIN IN EFFECT FOR QUITE SOME TIME. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...THE EXTENDED WILL BE MUCH LIKE THE SHORT TERM...AS A STAGNANT PATTERN KEEPS A COASTAL TROUGH JUST OFFSHORE AND A HIGH PRESSURE WEDGE INLAND. THIS PRODUCES A PROLONGED PERIOD OF NE WINDS DUE TO A PINCHED GRADIENT...AND WINDS OF 15-25 KTS WILL BE COMMON LATE WEEK. THIS EXTENDED PERIOD OF GUSTY NE WINDS WILL KEEP WAVE HEIGHTS AT 4-6 FT PRETTY MUCH THE ENTIRE FORECAST PERIOD...AND A SMALL CRAFT ADVISORY WHICH WILL LIKELY BE HOISTED EARLIER IN THE WEEK...WILL BE NEEDED FOR MOST...IF NOT ALL...OF THE LONG TERM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...TRA MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
649 AM EDT MON SEP 22 2014 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE OVER THE NORTHERN AND CENTRAL PLAINS WILL SETTLE OVER THE OHIO VALLEY TONIGHT AND TUESDAY. HIGH PRESSURE IS THEN FORECAST TO EXTEND ACROSS THE REGION THROUGH THE END OF THE WEEK. TEMPERATURES WILL START OUT COOL EARLY THIS WEEK...FOLLOWED BY A WARMING TREND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LARGE SCALE MID LEVEL TROUGH OVER THE EASTERN GREAT LAKES THIS MORNING WILL SHIFT EAST INTO NEW ENGLAND AND EASTERN CANADA THROUGH TODAY. AS THIS OCCURS...A SPRAWLING AREA OF SURFACE HIGH PRESSURE OVER THE NORTHERN AND CENTRAL PLAINS WILL MOVE/BUILD SOUTHEAST INTO OUR REGION. MAIN FORECAST DILEMMA TODAY WILL BE FIGURING OUT THE COVERAGE OF CAA STRATOCUMULUS AND HOW FAST THEY WILL EXIT THE AREA. HAVE USED THE RAP MODEL AS A GUIDE TO FIGURE THIS OUT WHICH KEEPS ROUGHLY THE EASTERN TWO THIRDS MOSTLY CLOUDY THROUGH MID MORNING FOLLOWED BY CLEARING SKIES AS SUBSIDENCE...DRYING AND ANTICYCLONIC FLOW INCREASE FROM THE WEST. TEMPERATURES WILL BE BELOW NORMAL FOR THE ARRIVAL OF AUTUMN WITH HIGHS RANGING FROM THE LOWER TO MID 60S. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... SURFACE HIGH PRESSURE WILL SETTLE OVER THE OHIO VALLEY TONIGHT. CLEAR SKIES...LIGHT TO CALM WINDS...AND A DRY AIRMASS WILL MAKE FOR FAVORABLE RADIATIONAL COOLING CONDITIONS. HAVE USED A BLEND OF THE ADJUSTED MAV GUIDANCE AND CONSENSUS RAW 2 METER TEMPERATURES TO TRY TO CAPTURE THE NORMALLY COOL SPOTS. LOWS WILL RANGE FROM THE UPPER 30S IN THOSE COOL SPOTS TO THE MID 40S AT RIDGE TOPS AND NEAR URBAN AREAS. THE HIGH WILL REMAIN IN PLACE ON TUESDAY. SUNNY SKIES AND A MODIFYING AIRMASS WILL ALLOW TEMPERATURES TO WARM INTO THE UPPER 60S TO THE LOWER 70S. A MID LEVEL RIDGE WILL BUILD INTO THE GREAT LAKES AND MIDDLE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. AT THE SAME TIME...SURFACE HIGH PRESSURE WILL EXTEND FROM NEW ENGLAND INTO THE OHIO VALLEY. LITTLE IF ANY CLOUD COVER IS EXPECTED THROUGH THE PERIOD. A WARMING TREND WILL CONTINUE DUE TO A WARMING/MODIFYING AIRMASS. DIURNAL SWINGS OF 25 TO 30 DEGREES WILL BE LIKELY GIVEN THE DRY AIRMASS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... MID/UPPER LEVEL RIDGING WILL REMAIN IN CONTROL THROUGH THE LONG TERM PERIOD. THE MODELS ARE HINTING AT SOME MOISTURE POSSIBLY TRYING TO WORK UP FROM THE SOUTH HEADING INTO THE WEEKEND...BUT WITH RIDGING OVERHEAD...WILL MAINTAIN A DRY FORECAST. TEMPERATURES WILL CONTINUE TO SLOWLY WARM AS THE AIRMASS CONTINUES TO MODIFY/WARM THROUGH THE END OF THE WEEK. TEMPERATURES THROUGH THIS PERIOD SHOULD RUN A FEW DEGREES ABOVE NORMAL. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... PATCHY MVFR CLOUDS ARE PERSISTING ACROSS THE REGION THIS MORNING. OVERALL CLOUD BASES GENREALLY RANGE FROM AROUND 2000-3000 FEET...WITH A FEW AREAS OF CEILINGS AS LOW AS 1500 FEET. THESE CLOUDS ARE EXPECTED TO REMAIN IN PLACE FOR THE NEXT FEW HOURS...ESPECIALLY AFFECTING THE CENTRAL OHIO TAF SITES. CEILINGS SHOULD LIFR TO VFR BY LATE MORNING. NNW WINDS WILL GENERALLY REMAIN IN THE 6-12 KNOT RANGE TODAY...BEFORE DIMINISHING THIS EVENING. WITH HIGH PRESSURE MOVING INTO THE AREA...CLEAR SKIES AND LIGHT WINDS WILL PERSIST INTO THE OVERNIGHT HOURS AND THROUGH TUESDAY. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HICKMAN NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...JGL AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
532 AM MDT MON SEP 22 2014 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 322 AM MDT MON SEP 22 2014 A FEW SHOWERS MOVING NORTHEAST ACROSS NORTHERN COLORADO BUT HAVING SOME TROUBLE SURVIVING OFF THE MOUNTAINS SO FAR. MEANWHILE AN UPPER LOW CURRENTLY AROUND THE UTAH/IDAHO BORDER WILL MOVE NORTHWARD THIS MORNING THEN TURN MORE EASTWARD THROUGH THIS EVENING EMERGING OVER THE NORTHERN HIGH PLAINS TONIGHT. AN IMPULSE ROTATING AROUND THE UPPER LOW WILL SWING ACROSS THE CWA THIS AFTERNOON AND EVENING WITH SCTD SHOWERS AND TSTRMS ASSOCIATED WITH IT. INSTABILITY WILL BE RATHER WEAK ACROSS MUCH OF THE CWA THIS AFTERNOON BUT A TONGUE OF BETTER INSTABILITY/CAPES 500-100 J/KG/ LOOKS TO NOSE UP OUT OF COLORADO INTO MAINLY THE SOUTHERN PANHANDLE INTO THIS EVENING WHICH WITH MARGINAL SHEAR MAY ALLOW FOR A FEW STRONGER STORMS THERE. ACTIVITY WILL MOVE OUT OF THE CWA TONIGHT AS THE UPPER IMPULSE SWINGS EAST OF THE AREA AND A WEAK PACIFIC FRONT MOVES OUT ACROSS THE HIGH PLAINS. MAINLY DRY AND WARM TUESDAY THOUGH ANOTHER MODEST SHORTWAVE CLIPPING NORTHEAST PARTS OF THE CWA MAY SET OFF A FEW SHOWERS/TSTMS OVER THAT AREA TUESDAY AFTERNOON. DRY AND WARMER WEDS AS AN UPPER RIDGE AMPLIFIES AND BUILDS NORTHEAST ACROSS THE NORTHERN AND CENTRAL ROCKIES. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 322 AM MDT MON SEP 22 2014 SHARP UPPER LEVEL RIDGING BUILDS INTO THE AREA WEDNESDAY NIGHT INTO THURSDAY. 700MB TEMPERATURES RESPOND AS WELL...CLIMBING TO +14C AND EVEN +16C ACROSS PORTIONS OF SOUTHERN CARBON AND ALBANY COUNTIES THURSDAY AFTERNOON. THIS IS UP FROM +10C TO +12C WEDNESDAY AFTERNOON. AS A RESULT...TEMPERATURES SHOULD BE WARMER AND ALMOST SUMMER LIKE WITH 90S IN THE PANHANDLE AND MID 80S OUT WEST. GOING TO BE DRY THROUGH AT LEAST FRIDAY AS WELL WITH SUNNY SKIES AND LIGHT WINDS. WEATHER BEGINS TO CHANGE SOME FRIDAY NIGHT INTO SATURDAY. MODELS INITIALLY IN GOOD AGREEMENT WITH A PACIFIC LOW PRESSURE SYSTEM MOVING INTO NEVADA OVERNIGHT FRIDAY. GFS MUCH FASTER...BY ROUGHLY 12 TO 18 HOURS ON THE EASTWARD MOVEMENT OF THIS LOW. NEW ECMWF SLOWER AND HAS THE LOW NOT MOVING INTO NEVADA UNTIL SATURDAY NIGHT/SUNDAY MORNING. GFS SOLUTION WOULD HAVE FAIRLY WIDESPREAD SHOWER ACTIVITY FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE SATURDAY NIGHT INTO SUNDAY. ECMWF SOLUTION HAS SHOWERS MOVING INTO CARBON COUNTY SUNDAY NIGHT INTO MONDAY. DID A BLEND OF THE TWO MODELS FOR POPS OVER THE WEEKEND WITH LOW CHANCE POPS SATURDAY NIGHT. BEST CHANCES LOOK TO BE THROUGH THE DAY SUNDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 529 AM MDT MON SEP 22 2014 LATEST MOSAIC RADAR SHOWING AREA OF SHOWERS OVER NORTH CENTRAL COLORADO CONTINUING TO MOVE NORTHEAST. SHOULD BE INTO THE SOUTH LARAMIE RANGE HERE BY SUNRISE. FORTUNATELY...LATEST HRRR SHOWING VFR CONDITIONS WITH SOUTHWEST WINDS IN THIS AREA OF SHOWERS. SO FLIGHT OPERATIONS SHOULD NOT BE OVERLY IMPACTED. && .FIRE WEATHER... ISSUED AT 322 AM MDT MON SEP 22 2014 NO SIGNIFICANT CONCERNS EXPECTED THROUGH AT LEAST MIDWEEK WITH MIN RELATIVE HUMIDITIES EXPECTED TO REMAIN ABOVE CRITICAL LEVELS FOR THE MOST PART. GUSTY WINDS EXPECTED THIS AFTERNOON OVER WESTERN AREAS THEN LESS WIND ANTICIPATED TUESDAY AND WEDS. SCTD SHOWERS AND TSTRMS TODAY WITH ACTIVITY MOVING EAST AND OUT OF THE AREA THIS EVENING. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RE LONG TERM...CLAYCOMB AVIATION...CLAYCOMB FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
658 PM EDT MON SEP 22 2014 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE AREA TONIGHT. TUESDAY THROUGH EARLY NEXT WEEK...STRONG HIGH PRESSURE WILL EXTEND INTO THE REGION FROM THE NORTH...AND A TROUGH OF LOW PRESSURE WILL PERSIST NEAR THE COAST. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... MAJOR CHANGES HAVE BEEN MADE IN THE SHORT TERM AS TEMPERATURES HAVE COOLED SIGNIFICANTLY IN THE WAKE OF SHOWERS/TSTMS. IT APPEARS THE FRONT HAS BEEN PUSHED OFFSHORE DUE TO CONVECTIVE OUTFLOW AND A BUBBLE HIGH THAT HAS DEVELOPED OVER THE SOUTHERN MIDLANDS. HIGHEST RAIN CHANCES WILL BE CLUSTERED ALONG THE COAST OVERNIGHT AS ISENTROPIC ASSENT ATOP THE OFFSHORE FRONT INCREASES IN RESPONSE TO THE UPPER LOW CUTTING OFF OVER THE CENTRAL GEORGIA. NEAR TERM POPS HAVE BEEN INCREASED TO 100 PERCENT ALONG THE COAST WITH 60-70 PERCENT INLAND. A RISK FOR FLASH FLOODING CONTINUES FOR PORTIONS OF THE CHARLESTON TRI-COUNTY AREA...ESPECIALLY IN BERKELEY COUNTY. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... IN THE WAKE OF COLD FROPA...THE OVERALL PATTERN WILL FEATURE STRONG HIGH PRESSURE CENTERED NORTH OF THE REGION...A PERSISTENT TROUGH OF LOW PRESSURE OVER COASTAL WATERS/CLOSE TO THE COAST AND A CUT-OFF UPPER LOW MEANDERING OVER OR CLOSE TO THE REGION. THE SYNOPTIC PATTERN WILL FAVOR PLENTY OF CLOUDS...BELOW NORMAL HIGH TEMPERATURES MAINLY IN THE 70S AND SOME DEGREE OF POPS MUCH OF THE TIME...TAPERED FROM SLIGHT CHANCE/CHANCE INLAND TO CHANCE/LIKELY NEAR THE COAST. CHANGES SHOULD REMAIN SUBTLE...AND FORECAST DETAILS INCLUDING DEVIATIONS FROM THIS GENERAL SCENARIO WILL BE ADDRESSED WITHIN SUBSEQUENT FORECAST PACKAGES...ESPECIALLY WITHIN THE UPCOMING NEAR TERM PERIODS. HIGHEST PWATS AND DEEPEST MOISTURE SHOULD REMAIN JUST OFF THE COAST. HOWEVER...SOME POTENTIAL EXISTS FOR DEEP MOISTURE/AN ASSOCIATED HEAVY RAIN THREAT TO PERIODICALLY BACK INTO COASTAL COUNTIES...DEPENDING IN PART ON THE ORIENTATION/EVOLUTION OF THE UPPER LOW. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... PERHAPS ONE OF THE LONGEST HIGH PRESSURE WEDGE PATTERNS IS IN STORE FOR THE MEDIUM TO LONG RANGE PERIODS. THE EXPANSIVE SURFACE HIGH OVER THE NORTHEAST STATES LOOKS TO REMAIN IN PLACE THROUGH SATURDAY NIGHT WHILE A COASTAL TROUGH MAINTAINS CONSIDERABLE CLOUDINESS... BETTER RAIN CHANCES AND COOL TEMPS. SUNDAY INTO MONDAY THERE ARE LARGE MODEL DIFFERENCES REGARDING THE POTENTIAL FOR A DEEP LONGWAVE UPPER TROUGH MOVING INTO THE EASTERN UNITED STATES. A GULF LOW PRESSURE SYSTEM MAY LIFT NORTHEAST LATE IN THE WEEKEND OR EARLY NEXT WEEK. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... KCHS...-RA WILL PERSIST AT KCHS WITH A RISK FOR SHOWER IMMEDIATE SHOWER IMPACTS LASTING TO ABOUT 03Z. SHOWER ACTIVITY WILL BECOME MORE SCATTERED IN NATURE OVERNIGHT SO ITS HARD TO PIN DOWN EXACTLY WHEN SHOWERS WILL AFFECT THE TERMINAL AFTER 03Z. WILL NOT CARRY ANY MENTION OF SHOWERS OVERNIGHT INTO TUESDAY...ALTHOUGH THERE WILL BE A RISK. LARGE DISCREPANCIES ON HOW LOW CIGS WILL GET OVERNIGHT. THE LATEST NAM AND LAV GUIDANCE KEEPS CIGS VFR WHILE THE RUC CRASHES CIGS TO LIFR AFTER 06Z. VERY TOUGH CALL ON THIS. OPTED TO A MIDDLE OF THE ROAD APPROACH WITH PREVAILING LOW-END MVFR CIGS 05-14Z WITH VFR THEREAFTER. AMENDMENTS WILL MOST CERTAINLY BE NEEDED OVERNIGHT AS TRENDS BECOME MORE APPARENT. KSAV...SHOWER ACTIVITY HAS GENERALLY ENDED...THOUGH LOW-END SCATTERED ACTIVITY WILL LINGER WEST AND NORTH OF THE TERMINAL THROUGH 05Z. OPTED FOR A TEMPO GROUP FOR HIGH END MVFR VSBYS IN -SHRA 02-05Z TO COVER. PREVAILING MVFR CIGS THEREAFTER WITH VFR RETURNING BY 14Z. EXTENDED AVIATION OUTLOOK...THU FRI BRIEF FLIGHT RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS TUESDAY THROUGH FRIDAY. CHANCES FOR MVFR CEILINGS INCREASE THURSDAY INTO FRIDAY AS LOW PRESSURE STRENGTHENS OFF THE COAST. && .MARINE... TONIGHT...THE APPROACHING COLD FRONT WILL BEGIN TO MOVE INTO AND THROUGH THE WATERS THIS EVENING. LIGHT SOUTHWEST FLOW WILL TURN AROUND TO EVENTUALLY BECOME NORTHEASTERLY THANKS TO THE HIGH PRESSURE BUILDING IN TO THE NORTH. THE STRENGTHENING NORTHEAST GRADIENT WILL SUPPORT A NOTEWORTHY SURGE LATE TONIGHT WITH ALMOST ALL OF THE WATERS BECOMING 15-20 KT. FOR NOW IT APPEARS THAT SMALL CRAFT ADVISORY WINDS WILL BE DELAYED UNTIL TUESDAY WHEN THE GRADIENT TIGHTENS MORE. ALSO...SINCE THE STRONGEST WINDS WILL NOT ARRIVE UNTIL AFTER THE TONIGHT PERIOD...SEAS WILL GENERALLY REMAIN 2-3 FT TONIGHT WITH A FEW 4 FOOTERS PERHAPS BLEEDING INTO THE CHARLESTON COUNTY WATERS VERY LATE. THUNDERSTORMS ALONG THE FRONT COULD BE STRONG TO SEVERE THIS EVENING...WITH THE MAIN THREAT BEING WIND GUSTS OF 40 KT. HIGH PRESSURE TO THE NORTH...A COASTAL TROUGH AND SOME DEGREE OF MARINE LAYER INSTABILITY/MIXING WILL CONTRIBUTE TO A PROLONGED PERIOD OF ELEVATED NORTHEAST WINDS/ASSOCIATED ELEVATED SEAS TUESDAY THROUGH FRIDAY. TO ADDRESS THE INITIAL SURFACE OF STRONG NORTHEAST WINDS AND BUILDING SEAS...RAISED SMALL CRAFT ADVISORIES FOR ALL MARINE ZONES BEGINNING TUESDAY MORNING NORTH...INCLUDING CHARLESTON HARBOR...AND EARLY TUESDAY AFTERNOON SOUTH. PER GUIDANCE SIGNALS SUGGESTING A SUBTLE LULL IN WINDS/SEAS THURSDAY...ENDED ALL ADVISORIES AT 5 AM THURSDAY MORNING. HOWEVER...CONFIDENCE IS NOT HIGH THAT ANY LULL WILL OCCUR...AND ADJUSTMENTS TO SMALL CRAFT ADVISORY TIMES COULD BE NEEDED TOWARD MIDWEEK. RIP CURRENTS...LOCAL GUIDANCE YIELDED A MODERATE RISK FOR RIP CURRENTS ON AREA BEACHES TUESDAY...MAINLY DUE TO STRONG ONSHORE WINDS. AN ELEVATED RISK FOR RIP CURRENTS WILL CONTINUE THROUGH AT LEAST LATE THIS WEEK...AND PERHAPS EVEN INTO THE WEEKEND. && .TIDES/COASTAL FLOODING... INCREASING NORTHEAST FLOW TUESDAY THROUGH NEXT WEEKEND WILL RESULT IN MODERATE CHANCES FOR SHALLOW COASTAL/SALT WATER FLOODING AROUND THE TIMES OF HIGH TIDE ESPECIALLY ALONG THE SC COAST INCLUDING DOWNTOWN CHARLESTON. SINCE RAINFALL AMOUNTS ARE EXPECTED TO BE HIGHEST NEAR THE COAST THROUGH THE PERIOD...SOME POTENTIAL EXISTS FOR A COMBINATION OF FRESH/SALT WATER FLOODING IF HEAVY RAIN FALLS NEAR THE TIMES OF HIGH TIDE. && .EQUIPMENT... THE DOWNTOWN CHARLESTON WEATHER SENSOR AT WATERFRONT PARK /KCXM/ IS INOPERABLE. IT IS UNKNOWN AT THIS TIME WHEN THE SENSOR WILL BE RETURNED TO SERVICE. HOURLY OBSERVATIONS AND DAILY CLIMATE INFORMATION WILL NOT BE AVAILABLE UNTIL FURTHER NOTICE. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 11 AM TUESDAY TO 5 AM EDT THURSDAY FOR AMZ330-352. SMALL CRAFT ADVISORY FROM 8 AM TUESDAY TO 5 AM EDT THURSDAY FOR AMZ350. SMALL CRAFT ADVISORY FROM 2 PM TUESDAY TO 5 AM EDT THURSDAY FOR AMZ354-374. && $$ ST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
226 PM CDT MON SEP 22 2014 .DISCUSSION... 135 AM CDT SYNOPSIS...AN EXTENDED PERIOD OF QUIET AND DRY WEATHER IS EXPECTED THROUGH NEXT WEEKEND. WE WILL ALSO BE EXPERIENCING A SLOW WARMING TREND WITH HIGHS IN THE 60S TODAY AND THEN HIGHS IN THE MID TO UPPER 70S BY LATE WEEK. TODAY THROUGH TUESDAY... THE UPPER LEVEL TROUGH IS PUSHING EAST AND AN UPPER LEVEL RIDGE WILL MOVE OVER THE REGION TONIGHT AND TUESDAY. HIGH PRESSURE IS OVER THE CENTRAL PLAINS EARLY THIS MORNING AND IT WILL DRIFT EAST OVER THE CWA TODAY. THE GRADIENT WILL WEAKEN ALLOWING WINDS TO DIMINISH THIS MORNING AND BECOME WEST TO SOUTHWEST BY THIS AFTERNOON. A WEAK LAKE BREEZE IS POSSIBLE IN COOK COUNTY LATE THIS AFTN. LOOKING AT A BEAUTIFUL SUNNY FALL DAY WITH HIGHS IN THE 60S. CLEAR CONDITIONS AND LIGHT WINDS CONTINUE TONIGHT WITH LOWS IN THE 50S NEAR THE LAKE AND IN THE 40S IN THE OUTLYING AREAS. THE CENTER OF THE HIGH MOVES OVER THE UPPER OHIO RIVER VALLEY TOMORROW AND LOOKING AT ANOTHER DRY AND SUNNY DAY. HIGH TEMPS WILL BE A BIT WARMER IN THE LOW 70S. THE WEAK PRESSURE GRADIENT MAY ALLOW A LAKE BREEZE TO FORM LATE IN THE AFTERNOON SO MAY SEE TEMPS STAY AROUND 70 ALONG THE LAKE. OTHERWISE LIGHT SW WINDS WILL BECOME S TO SE IN THE AFTERNOON. JEE TUESDAY NIGHT THROUGH THURSDAY... LARGE ANTI-CYCLONIC FEATURE WILL PERSIST...WITH A CONTINUED THEME OF DRY WEATHER AND LIGHT WINDS. MINIMAL CLOUD COVER DURING THE OVERNIGHT HOURS WITH LIGHT WINDS WILL ALLOW TEMPS TO EASILY RADIATE INTO THE UPR 40S/LOW 50S. AFTN HIGHS WILL RETURN TO NEAR SEASONAL CONDS GENERALLY IN THE LOW/MID 70S. POTENTIAL FOR A LAKE BREEZE IN THE AFTN HOURS WILL BRING COOLER TEMPS TO AREAS ADJACENT TO LAKE MICHIGAN. HIGH CONFIDENCE IN THE MEDIUM TERM. FRIDAY THROUGH SUNDAY... ENSEMBLES CONTINUE THE DRY THEME INTO THE UPCOMING WEEKEND...WITH MID-LVL RIDGING PROGGED TO SLIDE OVERHEAD AND AMPLIFY SLIGHTLY FRI/SAT. THIS WILL LIKELY RESULT IN A CONTINUED MODERATION TO AFTN TEMPS...POSSIBLY GOING ABOVE CLIMO IN THE UPR 70S TO PERHAPS 80 DEGREES SOUTH OF I-80 FRI/SAT. FOR THE SECOND HALF OF THE WEEKEND ENSEMBLE SUGGEST THE MID-LVL RIDGE WILL BEGIN TO DISSOLVE AND DRIFT EAST...WITH THE LONGWAVE PATTERN TURNING MORE SOUTHWESTERLY AS THE TROUGH ACROSS THE FOUR-CORNERS REGION BEGINS TO PIVOT EAST INTO THE SOUTHERN PLAINS. AT THIS TIME THOUGH GUIDANCE SUGGESTS PRECIP WILL REMAIN WEST OF THE FORECAST AREA THRU THE WEEKEND. GIVEN THE DRY CONDS AND MINIMAL CLOUDS/LGT WINDS...EXPECT OVERNIGHT LOWS TO EASILY RADIATE INTO THE LOW/MID 50S. HIGH CONFIDENCE IN THE EXTENDED FORECAST. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * NONE. KJB //DISCUSSION...UPDATED 18Z... SURFACE HIGH PRESSURE WILL DOMINATE ACROSS THE REGION THROUGH THE PERIOD. THIS WILL RESULT IN FAIRLY QUIET WEATHER CONDITIONS OVER THE AREA. AS A RESULT...NO SIGNIFICANT AVIATION WEATHER CONCERNS ARE EXPECTED. AN AFTERNOON LAKE BREEZE WILL LIKELY DEVELOP TODAY...HOWEVER...IT APPEARS THAT IT MAY REMAIN EAST OF THE MAIN AIR FIELDS. EVEN IF IT WERE TO MAKE IT ALL THE WAY TO ORD OR MDW LATE THIS AFTERNOON...WIND SPEEDS WOULD LIKELY REMAIN BELOW THE 10 KT THRESHOLDS. OTHERWISE...EXPECT A PREDOMINATELY LIGHT WESTERLY COMPONENT TO THE WIND TODAY AND TONIGHT...THEN GRADUALLY BACKING MORE SOUTHEASTERLY BY LATE TUESDAY AFTERNOON AS THE SURFACE HIGH DEPARTS TO THE EAST. KJB //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH FOR ALL ELEMENTS. KJB //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH SUNDAY...VFR. JEE && .MARINE... 224 PM CDT HIGH PRESSURE IS CENTERED OVER THE MID/UPPER MISSISSIPPI VALLEY THIS AFTERNOON WITH RIDGING EXTENDING OVER SOUTHERN LAKE MICHIGAN WHICH HAS RESULTED IN DIMINISHING WINDS TODAY. WAVES HAVE BEEN STEADILY SUBSIDING TODAY WITH WAVES AT THE MICHIGAN CITY BUOY BELOW 4 FT... SO WILL CANCEL THE REMAINDER OF THE SMALL CRAFT ADVISORY FOR THE NEARSHORE WATERS THIS AFTERNOON. THROUGH MIDWEEK...THE HIGH WILL TRANSLATE EAST ACROSS THE OHIO VALLEY INTO NEW ENGLAND WITH WINDS GRADUALLY BACKING TO THE SOUTH BY TUESDAY EVENING WHERE THEY SHOULD GENERALLY STAY THROUGH THE END OF THE WEEK. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 PM MONDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 PM MONDAY. && $$ 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 1226 PM CDT Mon Sep 22 2014 .UPDATE... ISSUED AT 1045 AM CDT MON SEP 22 2014 The forecast generally looks on track today with just very minor updates to sky grids over eastern IL where few to scattered cumulus clouds from I-57 east, especially near IN/IL border per NAM and RUC curule but still mostly sunny skies. Highs in the upper 60s to around 70F with north winds 5-10 mph. 1028 mb high pressure over nw IL and northern MO late this morning to settle over central IL tonight and continue fair weather with temperatures a bit below normal. Temps currently in the upper 50s and lower 60s should climb about another 10 degrees for highs in the upper 60s to around 70F this afternoon. Coolest readings over east central IL. && .SHORT TERM...(Today) ISSUED AT 341 AM CDT MON SEP 22 2014 High pressure centered over eastern Nebraska will move east into the area today. This will bring clear skies, dry weather and light winds. Even with lots of sunshine today, highs are only expected to reach into the upper 60s to around 70 degrees. GFS MOS guidance looks several degrees too warm, while the NAM is too cool. && .LONG TERM...(Tonight through Sunday) ISSUED AT 341 AM CDT MON SEP 22 2014 An extended period of quiet weather throughout the remainder of the forecast with high pressure building into and remaining in control of the Midwest. Surface ridge dominating much of the eastern half of the CONUS and keeping the weather quiet and fair, with slowly warming temps through the work week. Weak flow under the sfc high becomes more southerly on Tuesday as the ridge axis shifts slightly eastward. Warming trend continues with the thermal ridging over the desert SW slowly advecting into the center of the country and max temps are just above normals by Thursday. A weak trof brings some precip to the Plains Wednesday, but the ridge remains in place and dry air eroding the activity before impacting Central Illinois. In the extended, the GFS pushes some minor precip into the extreme SE with an oddly evolving upper pattern beyond day 6. ECMWF remaining dry and energy aloft without significant flow seeming to retrograde somewhat under a larger scale ridge. Keeping the forecast dry for next weekend until the models become a little more cohesive with their solutions under the pattern shift. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) ISSUED AT 1225 PM CDT MON SEP 22 2014 VFR conditions should continue across the central IL terminal airports through Tuesday. Clear skies to generally prevail with just a few cumulus clouds around 3k ft possible from CMI east. 1027 mb high pressure near the IL/IA border and northern MO will drift east across central IL tonight and into the Ohio river valley on Tue. This will continue the fair/dry weather across central IL, with no fog expected overnight due to dry airmass. Winds to stay light out of the north near 5 kts today, then light and variable to calm at times tonight, and light se winds afer 14Z/9 am Tue. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...AUTEN LONG TERM...HJS AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT MON SEP 22 2014 .DISCUSSION... 135 AM CDT SYNOPSIS...AN EXTENDED PERIOD OF QUIET AND DRY WEATHER IS EXPECTED THROUGH NEXT WEEKEND. WE WILL ALSO BE EXPERIENCING A SLOW WARMING TREND WITH HIGHS IN THE 60S TODAY AND THEN HIGHS IN THE MID TO UPPER 70S BY LATE WEEK. TODAY THROUGH TUESDAY... THE UPPER LEVEL TROUGH IS PUSHING EAST AND AN UPPER LEVEL RIDGE WILL MOVE OVER THE REGION TONIGHT AND TUESDAY. HIGH PRESSURE IS OVER THE CENTRAL PLAINS EARLY THIS MORNING AND IT WILL DRIFT EAST OVER THE CWA TODAY. THE GRADIENT WILL WEAKEN ALLOWING WINDS TO DIMINISH THIS MORNING AND BECOME WEST TO SOUTHWEST BY THIS AFTERNOON. A WEAK LAKE BREEZE IS POSSIBLE IN COOK COUNTY LATE THIS AFTN. LOOKING AT A BEAUTIFUL SUNNY FALL DAY WITH HIGHS IN THE 60S. CLEAR CONDITIONS AND LIGHT WINDS CONTINUE TONIGHT WITH LOWS IN THE 50S NEAR THE LAKE AND IN THE 40S IN THE OUTLYING AREAS. THE CENTER OF THE HIGH MOVES OVER THE UPPER OHIO RIVER VALLEY TOMORROW AND LOOKING AT ANOTHER DRY AND SUNNY DAY. HIGH TEMPS WILL BE A BIT WARMER IN THE LOW 70S. THE WEAK PRESSURE GRADIENT MAY ALLOW A LAKE BREEZE TO FORM LATE IN THE AFTERNOON SO MAY SEE TEMPS STAY AROUND 70 ALONG THE LAKE. OTHERWISE LIGHT SW WINDS WILL BECOME S TO SE IN THE AFTERNOON. JEE TUESDAY NIGHT THROUGH THURSDAY... LARGE ANTI-CYCLONIC FEATURE WILL PERSIST...WITH A CONTINUED THEME OF DRY WEATHER AND LIGHT WINDS. MINIMAL CLOUD COVER DURING THE OVERNIGHT HOURS WITH LIGHT WINDS WILL ALLOW TEMPS TO EASILY RADIATE INTO THE UPR 40S/LOW 50S. AFTN HIGHS WILL RETURN TO NEAR SEASONAL CONDS GENERALLY IN THE LOW/MID 70S. POTENTIAL FOR A LAKE BREEZE IN THE AFTN HOURS WILL BRING COOLER TEMPS TO AREAS ADJACENT TO LAKE MICHIGAN. HIGH CONFIDENCE IN THE MEDIUM TERM. FRIDAY THROUGH SUNDAY... ENSEMBLES CONTINUE THE DRY THEME INTO THE UPCOMING WEEKEND...WITH MID-LVL RIDGING PROGGED TO SLIDE OVERHEAD AND AMPLIFY SLIGHTLY FRI/SAT. THIS WILL LIKELY RESULT IN A CONTINUED MODERATION TO AFTN TEMPS...POSSIBLY GOING ABOVE CLIMO IN THE UPR 70S TO PERHAPS 80 DEGREES SOUTH OF I-80 FRI/SAT. FOR THE SECOND HALF OF THE WEEKEND ENSEMBLE SUGGEST THE MID-LVL RIDGE WILL BEGIN TO DISSOLVE AND DRIFT EAST...WITH THE LONGWAVE PATTERN TURNING MORE SOUTHWESTERLY AS THE TROUGH ACROSS THE FOUR-CORNERS REGION BEGINS TO PIVOT EAST INTO THE SOUTHERN PLAINS. AT THIS TIME THOUGH GUIDANCE SUGGESTS PRECIP WILL REMAIN WEST OF THE FORECAST AREA THRU THE WEEKEND. GIVEN THE DRY CONDS AND MINIMAL CLOUDS/LGT WINDS...EXPECT OVERNIGHT LOWS TO EASILY RADIATE INTO THE LOW/MID 50S. HIGH CONFIDENCE IN THE EXTENDED FORECAST. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * NONE. JEE/KB //DISCUSSION...UPDATED 12Z... HIGH PRESSURE WILL BUILD OVER THE REGION TODAY LEADING TO AN EXTENDED PERIOD OF QUIET VFR CONDITIONS. NORTH TO NORTHWEST WINDS WILL SLOWLY BACK TO WEST BY EARLY TO MID AFTERNOON. WIND SPEEDS WILL REMAIN LIGHT AROUND 7 KT. A LAKE BREEZE IS POSSIBLE MID TO LATE THIS AFTN BUT EXPECTING IT TO ONLY IMPACT WINDS AT GYY. IT MAY COME CLOSE TO MDW BUT THINKING IT WILL STOP JUST EAST OF MDW. AT GYY WINDS WILL BECOME NE MID THIS AFTN AND THEN VEER TO SW THIS EVENING. COULD SEE A FEW HOURS OF LIGHT AND VARIABLE WINDS AT GYY. OTHERWISE WINDS ACROSS THE BOARD REMAIN LIGHT AND SW OVERNIGHT THROUGH TUESDAY MORNING. JEE //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN ALL FORECAST ELEMENTS. JEE/KB //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH SUNDAY...VFR. JEE && .MARINE... 135 AM CDT FOR THE SMALL CRAFT ADVISORY...EXTENDED THE ADVISORY INTO THIS AFTERNOON FOR IL AND THIS EVENING FOR IN. WINDS REMAIN HIGH WITH GUSTS ARND 25 KT AT THE CRIB AND MICHIGAN CITY BUOY. THEREFORE EXPECTING WAVES TO DIMINISH SLOWER THAN PREVIOUSLY THOUGHT. HIGH PRESSURE WILL BUILD OVER THE REGION TODAY AND NORTH WINDS WILL DIMINISH AND BACK TO W OR NW. A LAKE BREEZE IS PSBL OVER COOK COUNTY THIS AFTN. THE HIGH CONTINUES EAST AND WINDS BECOME SOUTH ON ITS BACKSIDE TUESDAY AFTERNOON AND EVENING. SOUTH WINDS PERSIST INTO THE WEEKEND ARND 10 KT OR LESS. THE SOUTHERN HALF OF THE LAKE WILL HAVE SE TO E WINDS THROUGH THE WEEKEND AS WELL. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 PM MONDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 PM MONDAY. && $$ 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 1045 AM CDT Mon Sep 22 2014 .UPDATE... ISSUED AT 1045 AM CDT MON SEP 22 2014 The forecast generally looks on track today with just very minor updates to sky grids over eastern IL where few to scattered cumulus clouds from I-57 east, especially near IN/IL border per NAM and RUC curule but still mostly sunny skies. Highs in the upper 60s to around 70F with north winds 5-10 mph. 1028 mb high pressure over nw IL and northern MO late this morning to settle over central IL tonight and continue fair weather with temperatures a bit below normal. Temps currently in the upper 50s and lower 60s should climb about another 10 degrees for highs in the upper 60s to around 70F this afternoon. Coolest readings over east central IL. && .SHORT TERM...(Today) ISSUED AT 341 AM CDT MON SEP 22 2014 High pressure centered over eastern Nebraska will move east into the area today. This will bring clear skies, dry weather and light winds. Even with lots of sunshine today, highs are only expected to reach into the upper 60s to around 70 degrees. GFS MOS guidance looks several degrees too warm, while the NAM is too cool. && .LONG TERM...(Tonight through Sunday) ISSUED AT 341 AM CDT MON SEP 22 2014 An extended period of quiet weather throughout the remainder of the forecast with high pressure building into and remaining in control of the Midwest. Surface ridge dominating much of the eastern half of the CONUS and keeping the weather quiet and fair, with slowly warming temps through the work week. Weak flow under the sfc high becomes more southerly on Tuesday as the ridge axis shifts slightly eastward. Warming trend continues with the thermal ridging over the desert SW slowly advecting into the center of the country and max temps are just above normals by Thursday. A weak trof brings some precip to the Plains Wednesday, but the ridge remains in place and dry air eroding the activity before impacting Central Illinois. In the extended, the GFS pushes some minor precip into the extreme SE with an oddly evolving upper pattern beyond day 6. ECMWF remaining dry and energy aloft without significant flow seeming to retrograde somewhat under a larger scale ridge. Keeping the forecast dry for next weekend until the models become a little more cohesive with their solutions under the pattern shift. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) ISSUED AT 605 AM CDT MON SEP 22 2014 VFR conditions will continue at all sites next 24 hours. With high pressure moving into the area, skies will be clear next 24 hours with light and variable winds. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...AUTEN LONG TERM...HJS AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
247 PM MDT MON SEP 22 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 123 PM MDT MON SEP 22 2014 18Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED STRONG SHORT WAVE TROUGH MOVING TOWARDS THE TRI STATE AREA THROUGH NORTHERN COLORADO. AT THE SFC...TROUGHING NEAR THE KS/CO STATE LINE HAD RESULTED IN STRONG SOUTHERLY WINDS ACROSS THE WESTERN HALF OF THE CWA. MAIN FORECAST CONCERN WILL BE PRECIPITATION CHANCES THROUGH THE NIGHT AS AFOREMENTIONED STRONG TROUGH SWEEPS ACROSS THE AREA. NEAR TERM MODELS GENERALLY AGREE THAT ELEVATED MOSTLY WEAK INSTABILITY WILL GRADUALLY MOVE EAST TONIGHT...BUT NUMERICAL SOLUTIONS SHOWING A HIGH DEGREE OF VARIABILITY ESPECIALLY WITH RESPECT TO CONVECTIVE ALLOWING MODELS. HAVE GENERALLY FOLLOWED A CONSENSUS APPROACH HOLDING HIGHEST POPS ALONG NORTHERN CWA WHICH IS CLOSER TO UPPER LOW CENTER. MORNING UPSTREAM SOUNDINGS DO SUGGEST ANOMALOUSLY HIGH PW VALUES AROUND 200 PERCENT OF NORMAL...BUT WITH WEAK INSTABILITY...MODEL UNCERTAINTY AND SCATTERED NATURE OF CURRENT PRECIPITATION HAVE KEPT ONLY MODEST PRECIP AMOUNTS. PRECIP THREAT WILL DIMINISH TOMORROW MORNING AS UPPER TROUGH DEPARTS AND FRONT STALLS ACROSS SOUTHERN CWA. THIS FRONT MAY PROVIDE A FOCUS FOR AFTERNOON AND EARLY EVENING STORMS SHOULD CINH BE OVERCOME. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 247 PM MDT MON SEP 22 2014 AT THE BEGINNING OF THE EXTENDED PERIOD...NUMERICAL GUIDANCE IS CONSISTENT SHOWING A WEAKENING UPPER LOW OVER SOUTH DAKOTA MOVING INTO MINNESOTA WITH A TRAILING TROUGH MOVING EAST OVER CENTRAL AND EASTERN KANSAS. AFTER THAT...MODEL SOLUTIONS DIVERGE RAPIDLY AS TO THE FATE OF THE UPPER LOW. BY THURSDAY EVENING...GUIDANCE SHOWS THE UPPER LOW ANYWHERE FROM AMARILLO TX /NAM/ TO ROCHESTER MN /EC/. THE NAM LOOKS TOO FAR WEST AND TOO FAST WITH SLOWER EC/GFS PREFERRED. BUT CONFIDENCE IS LOW IN ANY GIVEN MODEL SOLUTION THROUGH THE ENTIRE EXTENDED PERIOD. THIS FORECAST PERIOD IS BASED ON A BLEND OF GENERAL MODEL TRENDS WHICH BASICALLY HAS THE REMAINS OF THE UPPER LOW MORE OVER CENTRAL AND EASTERN KANSAS WITH OUR AREA TEMPORARILY UNDER THE INFLUENCE OF THE UPSTREAM UPPER HIGH WHICH STRETCHES FROM THE DAKOTAS TO COLORADO. SO IN THE TUESDAY NIGHT INTO WEDNESDAY TIME FRAME... PRECIPITATION CHANCES ARE TRENDED DOWNWARD WEST TO EAST WITH SOMEWHAT BETTER FORCING ALOFT BEING TO OUR EAST. BY THE END OF THE WEEK...THE APPROACH OF THE NEXT SYSTEM IS EXPECTED TO INTERACT WITH THE REMAINS OF THE UPPER LOW AND BRING IT BACK NORTH...BUT TIMING AND LOCATION IS UNCERTAIN TO SAY THE LEAST. WEDNESDAY NIGHT THROUGH SATURDAY NIGHT WERE KEPT DRY UNTIL THE APPROACH OF THE NEXT VIGOROUS UPSTREAM SYSTEM BRINGS ANOTHER SHOT AT SHRA/TSRA. TEMPERATURES WILL BE ABOVE NORMAL IN THE 80S MID TO LATE WEEK BUT AS THE NEXT SYSTEM APPROACHES NEXT WEEKEND...AFTERNOON HIGHS SHOULD RETURN CLOSER TO NORMAL IN THE 70S WITH ENHANCED POTENTIAL FOR CLOUD COVER AND SCATTERED PRECIPITATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1208 PM MDT MON SEP 22 2014 MAIN CONCERN WILL BE STRONG SOUTHERLY WINDS TODAY FOLLOWED BY SCATTERED SHOWERS THROUGH THE EVENING HOURS. DO NOT ANTICIPATE GREATLY REDUCED FLIGHT CATEGORIES DUE TO RATHER HIGH CLOUD BASES AND FOR THE MOST PART ONLY WEAK INSTABILITY. COULD SEE A PERIOD OF LOW STRATUS AROUND 12Z BUT CONFIDENCE IN LONG LIVED PERIOD OF STRATUS IS LOW. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...DLF AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
141 PM MDT MON SEP 22 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 123 PM MDT MON SEP 22 2014 18Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED STRONG SHORT WAVE TROUGH MOVING TOWARDS THE TRI STATE AREA THROUGH NORTHERN COLORADO. AT THE SFC...TROUGHING NEAR THE KS/CO STATE LINE HAD RESULTED IN STRONG SOUTHERLY WINDS ACROSS THE WESTERN HALF OF THE CWA. MAIN FORECAST CONCERN WILL BE PRECIPITATION CHANCES THROUGH THE NIGHT AS AFOREMENTIONED STRONG TROUGH SWEEPS ACROSS THE AREA. NEAR TERM MODELS GENERALLY AGREE THAT ELEVATED MOSTLY WEAK INSTABILITY WILL GRADUALLY MOVE EAST TONIGHT...BUT NUMERICAL SOLUTIONS SHOWING A HIGH DEGREE OF VARIABILITY ESPECIALLY WITH RESPECT TO CONVECTIVE ALLOWING MODELS. HAVE GENERALLY FOLLOWED A CONSENSUS APPROACH HOLDING HIGHEST POPS ALONG NORTHERN CWA WHICH IS CLOSER TO UPPER LOW CENTER. MORNING UPSTREAM SOUNDINGS DO SUGGEST ANOMALOUSLY HIGH PW VALUES AROUND 200 PERCENT OF NORMAL...BUT WITH WEAK INSTABILITY...MODEL UNCERTAINTY AND SCATTERED NATURE OF CURRENT PRECIPITATION HAVE KEPT ONLY MODEST PRECIP AMOUNTS. PRECIP THREAT WILL DIMINISH TOMORROW MORNING AS UPPER TROUGH DEPARTS AND FRONT STALLS ACROSS SOUTHERN CWA. THIS FRONT MAY PROVIDE A FOCUS FOR AFTERNOON AND EARLY EVENING STORMS SHOULD CINH BE OVERCOME. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 237 AM MDT MON SEP 22 2014 500 MB SHORTWAVE TROUGH WILL BE EAST OF THE FORECAST AREA THURSDAY...THOUGH EASTWARD PROGRESSION WILL BE SLOW. AS STRONG 500 MB TROUGH DEVELOPS OVER THE PACIFIC NORTHWEST...MID LEVEL RIDGE WILL STRENGTHEN OVER THE ROCKY MOUNTAIN STATES. ASSOCIATED SUBSIDENCE AND DOWNWARD VERTICAL MOTION WILL PRODUCE DRY CONDITIONS OVER THE TRI- STATE AREA. EXPECT 500 MB RIDGE TO AMPLIFY OVER THE DAKOTAS FRIDAY IN RESPONSE TO CONTINUED DEEPENING OF THE PACIFIC NORTHWEST SYSTEM. FURTHER EAST...A STRENGTHENING RIDGE OVER THE SOUTHEASTERN UNITED STATES WILL KEEP THE PLAINS SHORTWAVE TROUGH FROM MOVING EAST. MODELS SHOW EITHER A RETROGRESSION WITH THE LOW OR SECONDARY DEVELOPMENT OF LOW PRESSURE OVER THE PLAINS. BOTH SOLUTIONS ARE SOMEWHAT UNUSUAL FOR THIS TIME OF YEAR. FOR NOW...WILL LEAN TOWARDS THE DRIER GFS...BUT CONFIDENCE IS RATHER LOW. ATTENTION WILL TURN TO THE PACIFIC NORTHWEST SYSTEM AS IT MOVES INLAND THROUGH THE WEEKEND. GFS AND ECMWF ARE GETTING MORE IN LINE WITH ANOTHER...THOUGH GFS IS FASTER WITH THE MAIN FEATURES. BY SUNDAY THE CENTER OF THE LOW WILL BE OVER THE GREAT BASIN...AND A SERIES OF SHORTWAVE TROUGHS WILL ADVECT OVER THE ROCKIES/PLAINS THROUGH THE WEEKEND. ASSOCIATED UPWARD VERTICAL MOTION COULD TRIGGER THUNDERSTORMS SATURDAY AFTERNOON/EVENING...BUT WILL KEEP THE FORECAST DRY FOR NOW DUE TO LACK OF MODEL CONSISTENCY IN REGARDS TO MOISTURE. THERE IS BETTER CHANCE OF THUNDERSTORMS SUNDAY AND SUNDAY NIGHT AS MAIN LOW CENTER MOVES OVER THE ROCKIES. LEE SIDE CYCLOGENESIS WILL DEVELOP SUNDAY AFTERNOON...SO LOW LEVEL CONVERGENCE NEAR THE SURFACE TROUGH AXIS WILL AID IN CONVECTIVE DEVELOPMENT. EXPECT SIMILAR CONDITIONS MONDAY...SO WILL KEEP CONVECTIVE CHANCES IN THE FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1208 PM MDT MON SEP 22 2014 MAIN CONCERN WILL BE STRONG SOUTHERLY WINDS TODAY FOLLOWED BY SCATTERED SHOWERS THROUGH THE EVENING HOURS. DO NOT ANTICIPATE GREATLY REDUCED FLIGHT CATEGORIES DUE TO RATHER HIGH CLOUD BASES AND FOR THE MOST PART ONLY WEAK INSTABILITY. COULD SEE A PERIOD OF LOW STRATUS AROUND 12Z BUT CONFIDENCE IN LONG LIVED PERIOD OF STRATUS IS LOW. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...MENTZER AVIATION...JRM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 PM EDT MON SEP 22 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 248 PM EDT MON SEP 22 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER THE GREAT LKS BTWN UPR RDG IN THE PLAINS AND TROF IN ERN NAMERICA. SFC HI PRES IS MOVING INTO THE MID MS RIVER VALLEY...WITH LLVL WNW FLOW ON THE NRN FLANK OF THIS FEATURE ADVECTING SOME DRY AIR SHOWN ON THE 12Z INL RAOB TOWARD UPR MI. THERE WERE SOME CLDS OVER MUCH OF THE AREA THIS MRNG ASSOCIATED WITH WAD/ISENTROPIC ASCENT BEST SHOWN ON THE 290K SFC /ABOUT H85/ THIS MRNG...BUT SINCE THE COOLER AIR UNDER THE TROF IN ERN CANADA IS RETREATING...LINGERING CLD COVER EARLY THIS AFTN HAS SHIFTED TO MAINLY THE ERN CWA. WITH MORE SUNSHINE OVER THE W...TEMPS HAVE RISEN ABV NORMAL AND TO 65-70 AWAY FM THE COOLING INFLUENCE OF THE LKS. LOOKING TO THE W...SKIES ARE MOCLR THRU MN UNDER H5 HGT RISES/SFC RDG AXIS EXTENDING N FM THE HI CENTER/DRY AIRMASS WITH PWAT AS LO AS 0.40-0.50 INCH...BUT MORE HI CLDS ARE SPREADING NE THRU THE NRN PLAINS IN ADVANCE OF A SHRTWV LIFTING THRU THE CENTRAL ROCKIES. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH DRY HI PRES EXPECTED TO DOMINATE. TNGT...WITH SFC HI PRES RDG MOVING OVER THE CWA UNDER RISING HGTS/ DRY AIRMASS...EXPECT MOCLR CONDITIONS. DESPITE THE DRYNESS OF THE INCOMING AIRMASS...THE WARMTH OF THIS AIR WITH H85 TEMPS FCST NEAR 12C AT 12Z TUE AS WELL AS STEADY WNW H925 WINDS UP TO 15-20 KTS WL KEEP TEMPS FM FALLING AS LO AS LAST NGT. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCENTRAL CLOSER TO THE LIGHTER H925 WINDS ASSOCIATED WITH HI PRES CENTER PASSING NEAR THE LOWER LKS. BUT TEMPS WL NOT FALL BLO 40...SO THERE WL BE NO FROST. TUE...AS THE SFC HI SHIFTS INTO THE MID ATLANTIC STATES...THE LLVL FLOW IS FCST TO BACK TO THE SSW. WITH PLENTY OF SUNSHINE UNDER LINGERING DRY AIRMASS AND H85 TEMPS HOLDING ARND 12C...EXPECT TEMPS TO TOP OUT IN THE 70S AWAY FM LK MODERATION...WHICH WL OCCUR MAINLY DOWNWIND OF LK MI. BUT RELATIVELY WEAK PRES GRADIENT FCST OVER THE UPR LKS...THERE WL BE SOME LK BREEZE FORMATION/LOCAL COOLING NEAR LK SUP. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 410 PM EDT MON SEP 22 2014 MUCH OF THIS PERIOD WILL REMAIN DRY. EXPECT HIGHS IN THE MID 60S TO MID 70S THROUGH AT LEAST SUNDAY...WHICH IS AROUND 5-10F ABOVE NORMAL FOR THIS TIME OF YEAR. AT THE SFC...THE HIGH OVER MUCH OF THE NE THIRD OF THE NATION WILL KEEP A RIDGE EXTENDED ACROSS THE UPPER GREAT LAKES THROUGH THE START OF THE WEEKEND. AT 00Z WEDNESDAY THE UPPER GREAT LAKES WILL BE DIRECTLY UNDER A 500MB RIDGE...WITH A CUT OFF LOW OVER THE DAKOTAS. EXPECT THE 500MB LOW TO OPEN UP BACK INTO THE MAIN FLOW...AND SETS UP A TROUGH ACROSS MN ON WEDNESDAY...BEFORE PUSHING ACROSS UPPER MI WEDNESDAY NIGHT INTO THURSDAY. THE RESULT ACROSS UPPER MI WILL BE A PARTLY TO MOSTLY CLOUDY SKY FROM W AFTERNOON THROUGH MUCH OF THURSDAY...PRIMARILY ACROSS THE W HALF. THE 500MB RIDGE WILL QUICKLY BUILD BACK OVERHEAD ON FRIDAY...EXTENDING FOR BASICALLY ALL BUT THE PACIFIC NW AND THE NEW ENGLAND STATES. WITH GENERALLY LIGHT WINDS AND FEW CLOUDS EACH NIGHT...WENT TOWARD THE LOWER END OF FCST GUIDANCE FOR MORNING LOWS. AND WITH PREDOMINANT S WINDS EACH DAY...THE DOWNSLOPE WAS PLAYED UP A BIT MORE NEAR LAKE SUPERIOR...WITH SOME OF THE TRADITIONAL SITES BEING INCREASED 1-4F. SUNDAY NIGHT THROUGH MONDAY BECOME A BIT MORE TRICKY WX/WIND WISE...WITH A SFC TROUGH SINKING IN FROM THE N. LIMITED MOISTURE AGAIN MAY BE LIMITED. WENT WITH A CONSENSUS SOLUTION...WITH SLIGHT CHANCE POPS COMING BACK INTO THE FCST FOR MONDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 124 PM EDT MON SEP 22 2014 EXPECT VFR CONDITIONS TO PREVAIL THIS TAF PERIOD WITH DRY HI PRES DOMINATING. STRONGER W WINDS THIS AFTN WL DIMINISH THIS EVNG WITH LOSS OF DAYTIME HEATING/MIXING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 248 PM EDT MON SEP 22 2014 W WINDS UP TO 25 KTS INTO THIS EVENING OVER THE NCENTRAL LAKE WILL DIMINISH OVERNIGHT WITH THE ARRIVAL OF A WEAKER PRES GRADIENT. WITH THIS RELATIVELY WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES THRU THE WEEK AND COOL LAKE WATERS/HI STABILITY...EXPECT WINDS NO HIER THAN 20 KTS INTO THIS WEEKEND. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
252 PM EDT MON SEP 22 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 248 PM EDT MON SEP 22 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER THE GREAT LKS BTWN UPR RDG IN THE PLAINS AND TROF IN ERN NAMERICA. SFC HI PRES IS MOVING INTO THE MID MS RIVER VALLEY...WITH LLVL WNW FLOW ON THE NRN FLANK OF THIS FEATURE ADVECTING SOME DRY AIR SHOWN ON THE 12Z INL RAOB TOWARD UPR MI. THERE WERE SOME CLDS OVER MUCH OF THE AREA THIS MRNG ASSOCIATED WITH WAD/ISENTROPIC ASCENT BEST SHOWN ON THE 290K SFC /ABOUT H85/ THIS MRNG...BUT SINCE THE COOLER AIR UNDER THE TROF IN ERN CANADA IS RETREATING...LINGERING CLD COVER EARLY THIS AFTN HAS SHIFTED TO MAINLY THE ERN CWA. WITH MORE SUNSHINE OVER THE W...TEMPS HAVE RISEN ABV NORMAL AND TO 65-70 AWAY FM THE COOLING INFLUENCE OF THE LKS. LOOKING TO THE W...SKIES ARE MOCLR THRU MN UNDER H5 HGT RISES/SFC RDG AXIS EXTENDING N FM THE HI CENTER/DRY AIRMASS WITH PWAT AS LO AS 0.40-0.50 INCH...BUT MORE HI CLDS ARE SPREADING NE THRU THE NRN PLAINS IN ADVANCE OF A SHRTWV LIFTING THRU THE CENTRAL ROCKIES. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH DRY HI PRES EXPECTED TO DOMINATE. TNGT...WITH SFC HI PRES RDG MOVING OVER THE CWA UNDER RISING HGTS/ DRY AIRMASS...EXPECT MOCLR CONDITIONS. DESPITE THE DRYNESS OF THE INCOMING AIRMASS...THE WARMTH OF THIS AIR WITH H85 TEMPS FCST NEAR 12C AT 12Z TUE AS WELL AS STEADY WNW H925 WINDS UP TO 15-20 KTS WL KEEP TEMPS FM FALLING AS LO AS LAST NGT. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCENTRAL CLOSER TO THE LIGHTER H925 WINDS ASSOCIATED WITH HI PRES CENTER PASSING NEAR THE LOWER LKS. BUT TEMPS WL NOT FALL BLO 40...SO THERE WL BE NO FROST. TUE...AS THE SFC HI SHIFTS INTO THE MID ATLANTIC STATES...THE LLVL FLOW IS FCST TO BACK TO THE SSW. WITH PLENTY OF SUNSHINE UNDER LINGERING DRY AIRMASS AND H85 TEMPS HOLDING ARND 12C...EXPECT TEMPS TO TOP OUT IN THE 70S AWAY FM LK MODERATION...WHICH WL OCCUR MAINLY DOWNWIND OF LK MI. BUT RELATIVELY WEAK PRES GRADIENT FCST OVER THE UPR LKS...THERE WL BE SOME LK BREEZE FORMATION/LOCAL COOLING NEAR LK SUP. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 220 AM EDT MON SEP 22 2014 AN UPPER RIDGE BUILDING OVER THE REGION ON TUESDAY WILL REMAIN IN PLACE THROUGH THE BEGINNING OF NEXT WEEK. THIS WILL LEAD TO DRY CONDITIONS ACROSS MUCH OF THE UPPER GREAT LAKES REGION. THE ONLY ITEM OF CONCERN IS AN UPPER WAVE MOVING THROUGH THE ROCKIES AT THIS TIME. AS IT MOVES INTO THE NORTHERN/CENTRAL PLAINS...THE NORTHERN HALF OF THE DISTURBANCE IS CLOSE ENOUGH TO A WAVE MOVING THROUGH CENTRAL CANADA TO BECOME CAUGHT UP IN THE FLOW AND SEPARATED OUT FROM THE REST OF THE FEATURE. MODELS STILL CONSISTENT ON THE BEST MOISTURE AND UPPER LEVEL ENERGY SLIDING NORTHEAST JUST TO THE WEST OF THE CWA. THUS...WILL KEEP THE SLIGHT CHANCE POPS CONFINED TO THE WEST OF THE CWA WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING...WITH MOSTLY CLOUDY SKIES OVER WESTERN UPPER MICHIGAN. OTHERWISE...IT WILL BE A PLEASANT END TO SEPTEMBER ACROSS THE AREA WITH A SURFACE HIGH STATIONED OVER THE NORTHEAST CONUS. THIS WILL LEAD TO LIGHT SOUTHERLY FLOW OVER THE UPPER GREAT LAKES REGION (AROUND A RIDGE STRETCHING NORTHWEST OVER THE AREA) AND ALLOW FOR ABOVE NORMAL TEMPERATURES THROUGH THE LONG TERM PERIOD. HIGHS MOST DAYS LOOK TO BE IN THE UPPER 60S TO LOWER 70S (OR ABOUT 5-10 DEGREES ABOVE NORMAL). THERE ARE INDICATIONS THE UPPER RIDGE WILL BREAK DOWN AROUND THE MIDDLE OF NEXT WEEK (AS THE UPPER TROUGH OVER THE WESTERN CONUS SHIFTS EAST)...WHICH WILL MARK THE RETURN TO MORE UNSETTLED WEATHER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 124 PM EDT MON SEP 22 2014 EXPECT VFR CONDITIONS TO PREVAIL THIS TAF PERIOD WITH DRY HI PRES DOMINATING. STRONGER W WINDS THIS AFTN WL DIMINISH THIS EVNG WITH LOSS OF DAYTIME HEATING/MIXING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 248 PM EDT MON SEP 22 2014 W WINDS UP TO 25 KTS INTO THIS EVENING OVER THE NCENTRAL LAKE WILL DIMINISH OVERNIGHT WITH THE ARRIVAL OF A WEAKER PRES GRADIENT. WITH THIS RELATIVELY WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES THRU THE WEEK AND COOL LAKE WATERS/HI STABILITY...EXPECT WINDS NO HIER THAN 20 KTS INTO THIS WEEKEND. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1230 PM CDT MON SEP 22 2014 .UPDATE... ISSUED AT 1026 AM CDT MON SEP 22 2014 UPDATE TO THE FORECAST TO ACCOUNT FOR THE BAND OF LIGHT RAIN SHOWERS CURRENTLY ACROSS NORTHEAST COLORADO...THIS BAND IS LIFTING TO THE NORTHEAST AND WILL IMPACT SOUTHWEST NEBRASKA AND THE EASTERN PANHANDLE OVER THE NEXT COUPLE HOURS. PREVIOUS FORECAST HAD THIS HANDLED WELL...JUST MINOR REVISIONS WERE IMPLEMENTED. THE 22.14Z RUC13 SEEMS TO BE HANDLING THE CURRENT SITUATION WELL AND IS BEING BLENDED WITH THE PREVIOUS FORECAST WHICH SUGGESTS A SLIGHT DELAY IN QPF OF AN HOUR OR TWO ACROSS SOUTHWEST NEBRASKA. IN ADDITION...INSTABILITY IS SOMEWHAT LACKING OVER THIS AREA...THUS SHOWERS SHOULD PREVAIL RATHER THAN STORMS THIS MORNING...BUT THE MODEL INDICATES A GRADUAL INCREASE WITH THE INSTABILITY PARAMETERS INTO THE AFTERNOON...THUNDER IS POSSIBLE THEN. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 401 AM CDT MON SEP 22 2014 TODAY AND TONIGHT...A DEEPENING SFC TROF WILL ADVANCE SOUTHEAST INTO WRN NEB TODAY AND TONIGHT. SFC WINDS ARE EXPECTED TO INCREASE TO 15 TO 25 MPH WITH GUSTS TO 35 MPH ACROSS NWRN ZONES. WINDS RELAX A BIT TONIGHT BUT REMAIN STRONG OFF THE SFC. THE LATEST MODEL CONSENSUS SUGGESTS CLUSTERS OF SHOWERS AND THUNDERSTORMS SHOULD BE UNDERWAY BY 21Z THIS AFTN AS AN UPPER LOW ACROSS IDAHO ADVANCES EAST TOWARD AND INTO WRN SD TODAY AND TONIGHT. THE SEVERE WEATHER POTENTIAL LOOKS LOW TODAY AND TONIGHT AS THE BETTER INSTABILITY REMAINS OVER ERN COLO. THE MODEL CONSENSUS SUGGESTS 1/4 TO 1/2 INCH OF RAIN TODAY AND TONIGHT ACROSS THE FCST AREA BUT THERE IS CERTAINLY THE POTENTIAL FOR MORE GIVEN PWS INCREASING TO 1.33 INCHES WHICH IS 200 PERCENT OF NORMAL. THE NAM INDICATED HIGHER VALUES. THE ONGOING CLOUD COVER ACROSS WRN NEB IS EXPECTED TO INCREASE AND EXPAND EAST TODAY. SOME CLEARING MAY DEVELOP IN THE WEST LATE TONIGHT. GIVEN THE HIGH MOISTURE AVAILABLE POPS ARE LIKELY SOUTH AND EAST TONIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 401 AM CDT MON SEP 22 2014 THE PRIMARY FORECAST CONCERN WILL BE THUNDERSTORM CHANCES TUESDAY...THEN WITH TEMPERATURES AND RAIN CHANCES WITH A RETROGRADING UPPER LEVEL SYSTEM THROUGHOUT THIS WEEK. TUESDAY...THE UPPER LEVEL LOW WILL BE PUSHING OUT OF THE ROCKY MOUNTAINS AND INTO THE NORTHERN PLAINS. THE MODELS ARE IN GOOD AGREEMENT WITH THE UPPER LOW CENTER MOVING ACROSS SOUTH DAKOTA THROUGH THE DAY...WITH VARIOUS WEAK SHORTWAVE IMPULSES MOVING AROUND THE SYSTEM. SHOWERS AND POTENTIALLY A FEW ISOLATED THUNDERSTORMS SHOULD BE EXITING THE FORECAST AREA TO THE EAST DURING THE MORNING HOURS. BY AFTERNOON...A SURFACE TROUGH WILL MAKE ITS WAY ACROSS THE PANHANDLE AND INTO WESTERN NEBRASKA. FORECAST SOUNDINGS SHOW LOCATIONS GENERALLY WEST OF HIGHWAY 83 WILL MIX OUT AND WITH STEEP LOW LEVEL AND MID LEVEL LAPSE RATES...CAPE VALUES INCREASE TO 1000-2000 J/KG BY LATE AFTERNOON AND WITH THE STRONG WARMING...SURFACE BASED CONVECTION IS LIKELY. THERE IS SOME DISCREPANCIES BETWEEN MODELS IN TERMS OF DEEP LAYER SHEAR...AS THE GFS IS MUCH STRONGER...SUGGESTING IN EXCESS OF 40KTS...WHILE THE NAM IS 20 TO 30KTS. EVEN WITH THE LOWER SHEAR...IT SHOULD BE SUFFICIENT FOR AT LEAST A FEW STRONGER STORMS LATER TUESDAY AFTERNOON. AREAS TO THE EAST WILL SEE COOLER HIGHS...IN THE UPPER 60S AND LOW 70S DUE TO THE PRECIPITATION EARLIER IN THE DAY AND ARE LOOKING TO STAY VERY CAPPED. THESE AREAS WILL STILL SEE STORMS MOVE IN DURING THE EVENING AND OVERNIGHT HOURS...BUT THEY SHOULD BECOME ELEVATED QUICKLY AND WITH A LACK OF INSTABILITY WOULD EXPECT THUNDER TO DECREASE...BUT THERE WILL BE AT LEAST A WEAK LOW LEVEL JET THAT COULD CONTINUE TO FEED THE STORMS THROUGH THE NIGHT AS THEY MOVE EAST. AT 12Z WEDNESDAY MORNING...THE MODELS HAVE MOVED THE UPPER LOW CENTER OVER SOUTHEAST SOUTH DAKOTA AND NORTHEAST NEBRASKA...AND WITH THE UPWARD FORCING SHIFTING TO THE EAST...PRECIPITATION SHOULD BE CLOSE TO...IF NOT COMPLETELY FINISHED LOCALLY. FAIRLY STRONG SUBSIDENCE BUILDS IN ACROSS THE FORECAST AREA THROUGH THE DAY WEDNESDAY BEHIND THE UPPER LEVEL SYSTEM LEADS TO A DRY FORECAST. WARMER AIR WILL BE ADVECTING INTO THE AREA DURING THE DAY AND WITH THE DRY AIR IN PLACE AND PLENTY OF SUNSHINE...STRONG WARMING IS EXPECTED WITH HIGHS IN THE 80S FOR THE WESTERN TWO-THIRDS OF THE FORECAST AREA. WITH THE UPPER LOW REMAINING OVER EASTERN NEBRASKA...THE EASTERN PARTS OF THE FORECAST AREA MAY SEE SOME RESIDUAL CLOUD COVER AND WITH COOLER TEMPERATURES ALOFT...WILL SEE COOLER TEMPERATURES WITH HIGHS LOOKING TO BE IN THE MID TO UPPER 70S. BEYOND WEDNESDAY THERE BEGINS TO BE SLIGHT DIVERGENCE IN THE MODEL SOLUTIONS IN TERMS OF THE UPPER LEVEL PATTERN. WHAT IS IN GOOD AGREEMENT IS A DEEP LONGWAVE TROUGH MOVING INTO THE WESTERN CONUS...WITH RIDGING BUILDING AHEAD OF IT INTO THE NORTHERN PLAINS. WHAT IS STARTING TO GET PROBLEMATIC IS THE CURRENT SYSTEM GETS STUCK UNDER THE LARGE RIDGE WHICH SPANS INTO THE EASTERN PART OF THE COUNTRY AND STARTS TO RETROGRADE. THE DISCREPANCIES LIE WITH HOW FAR WEST IT WILL MAKE IT. THE RIDGE TO THE WEST WILL KEEP SOUTHERLY FLOW IN THE LOWER LEVELS...KEEPING LOW LEVEL MOISTURE ACROSS THE FORECAST AREA WITH DEWPOINTS REMAINING IN THE UPPER 50S AND 60S...WHILE WEAK AND MINI SHORTWAVES MAY MOVE ACROSS THE FORECAST AREA AT TIMES LATER IN THE WEEK. THESE SMALL IMPULSES OF ENERGY AREN/T LOOKING TO GENERATE ENOUGH LIFT AT THIS POINT TO PROVIDE A NEED FOR RAIN IN THE FORECAST SO WILL KEEP A DRY FORECAST AT THIS TIME. WHAT THIS WILL MEAN IS LIKELY COOLER TEMPERATURES FOR LATE IN THE WEEK AS THE WARMER AIR WILL BE KEPT TO THE WEST AND NORTH OF THE LOCAL AREA DUE TO THE INFLUENCE OF THE UPPER LEVEL SYSTEM. THEN LOOKING INTO THE WEEKEND...OUT OF THE LONGWAVE TROUGH MOVING ONTO THE WEST COAST...A LOW WILL CLOSE OFF AND SLOWLY MIGRATE TOWARDS THE EAST. THERE IS DIFFERENCES WITH THE SPEED AS THE OPERATIONAL GFS IS FASTER THAN THE ECMWF AS WELL AS THE GFS ENSEMBLE MEAN. THE FASTER SOLUTION WOULD BRING CHANCES FOR SHOWERS AND THUNDERSTORMS BY SUNDAY AFTERNOON...WHILE THE SLOWER WOULD KEEP THINGS DRY INTO MONDAY. WILL BE KEEPING A CLOSE EYE ON THIS SYSTEM AS TIME GETS CLOSER TO GET A BETTER HANDLE ON THE FORECAST FOR THESE PERIODS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1230 PM CDT MON SEP 22 2014 FORECAST CONFIDENCE IN TIMING...DURATION...AND INTENSITY OF THE EXPECTED PRECIPITATION TODAY/TONIGHT IS LOWER THAN AVERAGE...WITH THAT BEING SAID...A LEAD DISTURBANCE WILL CONTINUE TO MOVE TO THE NORTHEAST THIS AFTERNOON ACROSS WESTERN NEBRASKA...POTENTIALLY SPREADING RAIN SHOWERS...POSSIBLY WITH EMBEDDED RUMBLES OF THUNDER TO BOTH THE KVTN AND KLBF TERMINALS. AT THIS TIME THERE LOOKS TO BE NO MAJOR DISRUPTIONS IN VISIBILITY OR CEILINGS THIS AFTERNOON AND EARLY EVENING...BUT THE CONTINUED INCREASE IN LOWER ATMOSPHERIC MOISTURE MAY ALLOW FOR MVFR OR LOWER LATE THIS EVENING OR OVERNIGHT. FORECAST UPDATES MAY BE NEEDED...AND ARE ANTICIPATED. OTHERWISE THE MAIN UPPER LEVEL LOW WILL EJECT TOWARD THE NORTHERN PLAINS OVERNIGHT...KEEPING UNSETTLED CONDITIONS IN THE REGION THROUGH THE ENTIRE FORECAST CYCLE...AT A MINIMUM CEILING SHOULD FALL TO MVFR OR LOWER AT BOTH TERMINALS AFTER 09Z TOMORROW...BUT RAIN IS ALSO A POSSIBILITY. WINDS WILL REMAIN GUSTY TODAY AND FROM THE SOUTH...WEAKEN SLIGHTLY OVERNIGHT...BUT THEN ARE ANTICIPATED TO INCREASE ONCE AGAIN LATE IN THE FORECAST PERIOD. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JACOBS SHORT TERM...CDC LONG TERM...BROOKS AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1155 AM MDT MON SEP 22 2014 .UPDATE... ISSUED AT 1113 AM MDT MON SEP 22 2014 TWO DISTINCT AREAS OF RAIN ARE CURRENTLY MOVING OVER THE CWA. ONE IS ACROSS THE NEBRASKA PANHANDLE WITH GENERALLY LIGHT RAIN OBSERVED AND NO LIGHTNING. THE OTHER IS TO THE WEST OF THE LARAMIE RANGE CLOSER TO THE MIDLVL LOW CENTER AND THERE IS ISOLATED EMBEDDED TSTMS. THE QUESTION THIS AFTN IS HOW MUCH CLEARING AND INSTABILITY WILL BE PRESENT OVER THE PLAINS. BOTH THE GFS AND NAM SHOW LI VALUES OF AROUND -3C TO -4C ALONG THE WY-NE BORDER AND EASTWARD INTO THE PANHANDLE AT 00Z. COMBINED WITH MODEST DEEP LAYER SHEAR (AROUND 30 KTS) COULD SEE SOME STRONGER STORMS WITH SMALL HAIL. THE HRRR ALSO INDICATES A FEW HIGHER REFLECTIVITY CORES DEVELOPING IN THE SOUTHERN PANHANDLE AFTER 23Z. THUS...ADDED THE MENTION OF SMALL HAIL INTO THE GRIDS FOR MUCH OF THE PANHANDLE AND FAR EASTERN LARAMIE COUNTY DURING THE AFTN AND EARLY EVENING. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 322 AM MDT MON SEP 22 2014 A FEW SHOWERS MOVING NORTHEAST ACROSS NORTHERN COLORADO BUT HAVING SOME TROUBLE SURVIVING OFF THE MOUNTAINS SO FAR. MEANWHILE AN UPPER LOW CURRENTLY AROUND THE UTAH/IDAHO BORDER WILL MOVE NORTHWARD THIS MORNING THEN TURN MORE EASTWARD THROUGH THIS EVENING EMERGING OVER THE NORTHERN HIGH PLAINS TONIGHT. AN IMPULSE ROTATING AROUND THE UPPER LOW WILL SWING ACROSS THE CWA THIS AFTERNOON AND EVENING WITH SCTD SHOWERS AND TSTRMS ASSOCIATED WITH IT. INSTABILITY WILL BE RATHER WEAK ACROSS MUCH OF THE CWA THIS AFTERNOON BUT A TONGUE OF BETTER INSTABILITY/CAPES 500-100 J/KG/ LOOKS TO NOSE UP OUT OF COLORADO INTO MAINLY THE SOUTHERN PANHANDLE INTO THIS EVENING WHICH WITH MARGINAL SHEAR MAY ALLOW FOR A FEW STRONGER STORMS THERE. ACTIVITY WILL MOVE OUT OF THE CWA TONIGHT AS THE UPPER IMPULSE SWINGS EAST OF THE AREA AND A WEAK PACIFIC FRONT MOVES OUT ACROSS THE HIGH PLAINS. MAINLY DRY AND WARM TUESDAY THOUGH ANOTHER MODEST SHORTWAVE CLIPPING NORTHEAST PARTS OF THE CWA MAY SET OFF A FEW SHOWERS/TSTMS OVER THAT AREA TUESDAY AFTERNOON. DRY AND WARMER WEDS AS AN UPPER RIDGE AMPLIFIES AND BUILDS NORTHEAST ACROSS THE NORTHERN AND CENTRAL ROCKIES. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 322 AM MDT MON SEP 22 2014 SHARP UPPER LEVEL RIDGING BUILDS INTO THE AREA WEDNESDAY NIGHT INTO THURSDAY. 700MB TEMPERATURES RESPOND AS WELL...CLIMBING TO +14C AND EVEN +16C ACROSS PORTIONS OF SOUTHERN CARBON AND ALBANY COUNTIES THURSDAY AFTERNOON. THIS IS UP FROM +10C TO +12C WEDNESDAY AFTERNOON. AS A RESULT...TEMPERATURES SHOULD BE WARMER AND ALMOST SUMMER LIKE WITH 90S IN THE PANHANDLE AND MID 80S OUT WEST. GOING TO BE DRY THROUGH AT LEAST FRIDAY AS WELL WITH SUNNY SKIES AND LIGHT WINDS. WEATHER BEGINS TO CHANGE SOME FRIDAY NIGHT INTO SATURDAY. MODELS INITIALLY IN GOOD AGREEMENT WITH A PACIFIC LOW PRESSURE SYSTEM MOVING INTO NEVADA OVERNIGHT FRIDAY. GFS MUCH FASTER...BY ROUGHLY 12 TO 18 HOURS ON THE EASTWARD MOVEMENT OF THIS LOW. NEW ECMWF SLOWER AND HAS THE LOW NOT MOVING INTO NEVADA UNTIL SATURDAY NIGHT/SUNDAY MORNING. GFS SOLUTION WOULD HAVE FAIRLY WIDESPREAD SHOWER ACTIVITY FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE SATURDAY NIGHT INTO SUNDAY. ECMWF SOLUTION HAS SHOWERS MOVING INTO CARBON COUNTY SUNDAY NIGHT INTO MONDAY. DID A BLEND OF THE TWO MODELS FOR POPS OVER THE WEEKEND WITH LOW CHANCE POPS SATURDAY NIGHT. BEST CHANCES LOOK TO BE THROUGH THE DAY SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING) ISSUED AT 1145 AM MDT MON SEP 22 2014 AVIATION CONCERNS ARE FOCUSED IN THE FIRST 6-12 HOURS OF THE TERMINAL AS AN AREA OF LOW PRESSURE PUSHES THROUGH. 17-18Z RADAR RETURNS SHOW FIRST BAND OF RAIN SHOWERS LIFTING ACROSS THE WRN NEBRASKA PANHANDLE SITES...WITH THE 2ND PRECIP BAND APPROACH KLAR. PREDOMINATED THE INITIAL BAND OF PRECIP AT KAIA AND KCDR. THE 2ND BAND OF PRECIP WILL INCREASE IN COVERAGE AND INTENSITY THE AIR MASS DESTABILIZES THIS AFTERNOON. AS SUCH...WAS CONFIDENT ENOUGH TO ADD A TEMPO GROUP TO KLAR...WITH VCTS ELSEWHERE. WILL UNDOUBTEDLY NEED TO ADD SOME TEMPO GROUPS TO OTHER SITES EAST OF THE PLAINS THIS AFTERNOON...HOWEVER LESS CONFIDENT ON TIMING AND PLACEMENT AT THIS TIME. LOW PRESSURE AREA PUSHES EAST OF THE AREA EARLY TUESDAY...WITH CONDITIONS IMPROVING WEST TO EAST. OUTSIDE OF THE TEMPO -TSRA GROUP AT KLAR...HAVE KEPT AREA TERMINALS VFR AT THIS POINT...WITH THE EXPECTATION THAT THESE SOME AREAS WILL SEE MVFR VSBYS IN HEAVIER SHOWERS/STORMS THIS AFTERNOON. && .FIRE WEATHER... ISSUED AT 322 AM MDT MON SEP 22 2014 NO SIGNIFICANT CONCERNS EXPECTED THROUGH AT LEAST MIDWEEK WITH MIN RELATIVE HUMIDITIES EXPECTED TO REMAIN ABOVE CRITICAL LEVELS FOR THE MOST PART. GUSTY WINDS EXPECTED THIS AFTERNOON OVER WESTERN AREAS THEN LESS WIND ANTICIPATED TUESDAY AND WEDS. SCTD SHOWERS AND TSTRMS TODAY WITH ACTIVITY MOVING EAST AND OUT OF THE AREA THIS EVENING. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...FINCH SHORT TERM...RE LONG TERM...CLAYCOMB AVIATION...HAHN FIRE WEATHER...RE