Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/21/13


AREA FORECAST DISCUSSION
NWS RENO NV
653 PM PDT THU JUN 20 2013 .UPDATE... A FEW LIGHTNING STRIKES HAVE BEEN NOTED ALONG THE NV/OR BORDER IN NRN WASHOE COUNTY EARLY THIS EVENING. A RAWS SITE AT CATNIP MOUNTAIN REPORTED 0.03 INCHES OF RAIN IN THE LAST HOUR WITH A MAX WIND GUST TO 38 MPH WHILE SURPRISE VALLEY RAWS JUST REPORTED 0.05 INCHES OF RAIN IN THE LAST HOUR. LATEST IR SATELLITE IMAGERY SHOWS FAIRLY WARM CLOUD TOPS IN THAT AREA WHILE WATER VAPOR IMAGERY SHOWS A JET STREAK PUNCHING EAST ACROSS FAR SRN OREGON. THIS JET SUPPORT SHOULD PROVIDE ENOUGH DYNAMICS TO MAINTAIN LOW TOPPED ISOLATED TSTMS THROUGH THE EVENING OVER FAR NRN WASHOE COUNTY AND THE SURPRISE VALLEY...ALTHOUGH THE SPEED OF THE CELLS MAY LIMIT THE CHANCE OF SHOWERS...WITH WETTING RAINS ESPECIALLY HARD TO COME BY. LATEST HRRR MODEL GUIDANCE SHOWS CELLS OVER THIS AREA THROUGH ROUGHLY 06 UTC...WHICH MATCHES FAIRLY WELL WITH THE CURRENT FORECAST. SO FOR NOW WILL PLAN NO SIGNIFICANT CHANGES TO THE EVENING FORECAST. WILL LEAVE MENTION OF ISOLATED SHOWERS BUT MOST AREAS NORTH OF GERLACH WILL SEE LITTLE IF ANY PCPN. 20 && .PREVIOUS DISCUSSION... /ISSUED 324 PM PDT THU JUN 20 2013/ SYNOPSIS... DRY WEATHER WILL PREVAIL THROUGH SATURDAY WITH GENERALLY LIGHT WINDS. BELOW NORMAL TEMPERATURES FRIDAY WILL WARM TO NEAR SEASONAL AVERAGE BY SATURDAY. COOLER WEATHER IS EXPECTED SUNDAY THROUGH TUESDAY WITH INCREASED CLOUD COVER AND CHANCE FOR RAIN ESPECIALLY NORTH OF INTERSTATE 80. LATER NEXT WEEK, THE REGION DRIES OUT WITH TEMPERATURES SURGING TO WELL ABOVE AVERAGE. SHORT TERM... NO SIGNIFICANT CHANGES TO THE SHORT TERM FORECAST WITH THE MAIN FORECAST CONCERNS REMAINING IN THE LONG TERM. AN UPPER DISTURBANCE WILL MOVE ACROSS EXTREME SOUTHERN OREGON THIS EVENING. THE WATER VAPOR CLEARLY SHOWS THE IMPULSE AND THE COOLING CLOUD TOPS INDICATIVE OF UPPER FORCING OVER SOUTHERN OREGON AT THIS TIME. RIGHT NOW, THE CUMULUS OVER NORTHERN WASHOE COUNTY AND THE SURPRISE VALLEY IS CAPPED. HOWEVER, AS FORCING ARRIVES IN THE NEXT FEW HOURS, THE OPPORTUNITY FOR A FEW SHOWERS OR STORMS EXISTS SO I HAVE CONTINUED THE ISOLATED SHOWERS/STORMS THROUGH EVENING. ON FRIDAY, NORTHWEST FLOW ALOFT WILL BRING A REINFORCING SHOT OF COOL AIR INTO THE REGION SO TEMPERATURES WILL REMAIN BELOW AVERAGE. ON SATURDAY, AN UPPER RIDGE BRIEFLY BUILDS OVERHEAD FOR MAINLY SUNNY SKIES AND A WARM UP TO AROUND SEASONAL AVERAGES. SNYDER LONG TERM...SUNDAY THROUGH THURSDAY... OVERALL TRENDS CONTINUE TO FAVOR A WETTER AND COOLER PATTERN STARTING SUNDAY AND LINGERING THRU TUESDAY, WITH THE BEST CHANCE OF RAIN MONDAY AND MONDAY NIGHT NORTH OF INTERSTATE 80. DRIER AND MUCH WARMER CONDITIONS THEN RETURN LATER NEXT WEEK. UNUSUALLY HIGH PW MOISTURE PLUME FOR THIS TIME OF YEAR, WHICH INCLUDES REMNANT MOISTURE FROM A WESTERN PACIFIC TROPICAL STORM, WILL SPREAD ACROSS THE PACIFIC AND REACH THE WEST COAST BY EARLY NEXT WEEK. INITIAL SHORTWAVE ON SUNDAY WILL BRING A CHANCE OF SHOWERS MAINLY IN NORTHEAST CA-NORTHWEST NV SUNDAY AFTN-EVE, WITH WIDESPREAD CLOUD COVER OVER THE REST OF THE REGION. A BRIEF BREAK IN PRECIP IS POSSIBLE LATE SUNDAY NIGHT, THEN THE MAIN PUSH OF MOISTURE IS PROJECTED TO SPREAD ACROSS CALIFORNIA ON MONDAY WITH PW VALUES ON THE GFS ABOVE 1.25 INCH ALONG NEARLY THE ENTIRE CA COAST. PEAK PW VALUES ARE NEAR 1.75 INCH AROUND SF BAY. WITH THE LATEST ECMWF AND MORE ENSEMBLE MEMBERS ALSO TRENDING TOWARD THE WETTER GFS AND EXPANDING PRECIP FARTHER SOUTH INTO THE SIERRA AND WESTERN NV NORTH OF I-80, CONFIDENCE IS INCREASING FOR A WIDESPREAD AREA OF RAIN OVER NORTHEAST CA AND FAR NORTHWEST NV. THE TAHOE BASIN AND EVEN PORTIONS OF WESTERN NV INCLUDING THE RENO-CARSON VICINITY MAY ALSO RECEIVE SOME MEASURABLE RAIN DURING THIS EVENT, ALTHOUGH AMOUNTS IN THESE AREAS ARE HIGHLY DEPENDENT ON THE SOUTHERN EXTENT OF THE MOISTURE PLUME AND THE ORIENTATION OF THE PACIFIC JET STREAM. FARTHER SOUTH, SOME RAIN IS NOW POSSIBLE IN MONO COUNTY MAINLY WEST OF HIGHWAY 395, BUT POSSIBILITY OF MEASURABLE PRECIP IN WESTERN NV SOUTH OF HIGHWAY 50 IS STILL SLIM. THIS RAIN COULD CONTINUE THRU MONDAY NIGHT AND TUESDAY, ALTHOUGH THE OVERALL FORCING AND JET SUPPORT RETREATS FARTHER NORTH, WHICH WOULD LIMIT MOST OF THE MEASURABLE RAINFALL TO NORTHEAST CA-FAR NORTHWEST NV, AND NEAR THE SIERRA CREST WEST OF TAHOE. DUE TO THE WIDESPREAD THICK CLOUD COVER AND PERIODS OF RAIN, DAYTIME TEMPS WERE REDUCED FURTHER FOR SUNDAY THRU TUESDAY. THE COOLEST DAY IS EXPECTED ON MONDAY WHERE TEMPS IN LOWER ELEVATIONS NORTH OF HIGHWAY 50 SHOULD REMAIN BELOW 80 DEGREES, WITH EVEN COOLER TEMPS IN AREAS WHERE STEADY RAIN PERSISTS ALL DAY. GUSTY WINDS ARE LIKELY ON RIDGES FROM SUNDAY THRU TUESDAY AS 700 MB FLOW RANGES FROM 25-40 KT, BUT SPEEDS IN LOWER ELEVATIONS SHOULD BE MORE LIMITED WITH GUSTS MAINLY 30 MPH OR LESS DUE TO THE PRESENCE OF CLOUDS AND PRECIP. FOR NEXT WED-THURS, DRIER CONDITIONS WITH A WARMING TREND ARE EXPECTED AS UPPER LEVEL RIDGE OVER THE SOUTHWEST US ATTEMPTS TO EXPAND WEST INTO THE GREAT BASIN. WHILE CONFIDENCE IS HIGH FOR TEMPS RETURNING TO THE 90S FOR MOST OF WESTERN NV WED-THURS, THE POSSIBILITY FOR TRIPLE DIGIT HEAT IS LESS CERTAIN. THE GFS KEEPS SOUTHWEST FLOW ALOFT OVER THE SIERRA WITH THE RIDGE CENTER PINNED TO THE FOUR CORNERS REGION, WHILE THE ECMWF SLOWLY SPREADS THE RIDGE FARTHER WEST. IF THE WARMER ECMWF SCENARIO VERIFIES, ISOLATED CONVECTION MAY DEVELOP IN MINERAL-MONO COUNTIES BY THURSDAY BUT THE GFS SCENARIO IS MORE UNFAVORABLE FOR THUNDERSTORM FORMATION. THE CURRENT FORECAST WILL INDICATE AFTERNOON CUMULUS BUILDUPS SOUTH OF HIGHWAY 50 BUT NO MENTION OF THUNDER. MJD AVIATION... VFR WITH NO MAJOR CONCERNS THROUGH FRIDAY. RELATIVELY LIGHT WINDS THROUGH FRIDAY WITH WIND GUSTS TO AROUND 20 KTS IN THE AFTERNOONS AND EVENINGS. PRECIPITATION WISE, ISOLATED THUNDERSTORMS ARE POSSIBLE THROUGH THIS EVENING OVER FAR NORTHERN CALIFORNIA AND NORTHWEST NEVADA AS AN UPPER LOW OVER SOUTHERN OREGON SLIDES ALONG THE CALIFORNIA, OREGON, AND NEVADA BORDER. BASES ARE HIGH AT AROUND 110-130 MSL SO NO TERRAIN OBSCURATION EXPECTED IN THE WARNERS. LITTLE WIND IS EXPECTED OUT OF STORMS BUT SMALL PEA HAIL IS POSSIBLE WITH RELATIVELY LOW FREEZING LEVELS. SNYDER && .REV WATCHES/WARNINGS/ADVISORIES... NV...NONE. CA...NONE. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
835 AM PDT WED JUN 19 2013 .DISCUSSION...AS OF 08:35 AM PDT WEDNESDAY...THE UPPER LEVEL TROUGH THAT MOVED ACROSS NORTHERN CALIFORNIA YESTERDAY SUCCESSFULLY CLEARED OUT THE MARINE LAYER OVERNIGHT. THIS MORNING THE SKIES ARE MOSTLY CLEAR WITH COOLER MORNING TEMPERATURES. WENT AHEAD AND DID A QUICK FORECAST UPDATE TO REMOVE CLOUDS AND FOG FROM THE FIRST PERIOD FORECAST. EXPECTING SLIGHTLY WARMER TEMPERATURES TODAY UNDER SUNNY SKIES. A WEAK UPPER LEVEL RIDGE IS FORECAST TO BUILD IN OVER THE WEST DURING THE NEXT FEW DAYS. THIS WILL ALLOW A GRADUAL WARMING TREND THAT WILL LAST INTO THE WEEKEND. BY SATURDAY HIGHS ARE EXPECTED TO WARM INTO THE 60S AND 70S COAST SIDE...80S AROUND THE BAY WITH LOWER TO MID 90S POSSIBLE IN THE WARMEST INTERIOR LOCATIONS. TEMPERATURES ARE PROGGED TO COOL OFF BEGINNING ON SUNDAY AS AN UPPER TROUGH RE-ESTABLISHES ALONG THE COAST. LAST NIGHT`S RUN OF THE ECMWF EVEN BRINGS PRECIPITATION TO NORTHERN CALIFORNIA INCLUDING THE NORTHERN PORTIONS OF OUR CWA BY MONDAY AND TUESDAY. THIS WOULD BE NICE IF IT VERIFIES...BUT WILL WAIT A FEW MORE MODEL RUNS BEFORE COMPLETELY BUYING INTO THIS SCENARIO. SUMMER BEGINS AT 05:04Z ON JUNE 21ST...OR 10:04 PM PDT JUNE 20TH. && .AVIATION...AS OF 4:40 AM PDT WEDNESDAY...EXTREMELY DIFFICULT FORECAST THIS MORNING AS NUMEROUS UPPER LEVEL IMPULSES MOVE EAST ACROSS THE AREA AROUND AN UPPER LOW OVER THE CA/OR BORDER. THIS UPPER LOW HAS CAUSED MANY PROBLEMS THE PAST FEW DAYS...WASHING OUT THE MARINE LAYER AND MAKING IT VERY DIFFICULT TO FORECAST STRATUS FORMATION AND DISSIPATION. PATCHY STRATUS DEVELOPED YESTERDAY EVENING AND CONTINUES TO SLOWLY EXPAND. MOST TERMINALS WILL SEE BRIEF MVFR TO IFR CIGS THROUGH 16Z. SHORT TERM MODELS INCLUDING THE HRRR AND THE LOCAL WRF INDICATE THAT VFR CONDITIONS WILL PREVAIL AFTER 16Z. LOW CONFIDENCE. OTHERWISE...MODERATE ONSHORE FLOW THIS AFTERNOON INTO THE EARLY EVENING HOURS. VICINITY OF KSFO...PATCHY MVFR CIGS WILL BE PRESENT NEAR THE TERMINAL THROUGH AT LEAST 16Z. VERY LOW CONFIDENCE. MODERATE TO STRONG WEST WINDS THIS AFTERNOON...WITH GUSTS TO JUST OVER 30 KT. KSFO BRIDGE APPROACH...PATCHY STRATUS IS MORE LIKELY TO IMPACT THE TERMINAL THROUGH 17Z. LOW CONFIDENCE. MONTEREY BAY AREA TERMINALS...PATCHY MVFR TO IFR CIGS THROUGH 16Z. LOW CONFIDENCE. MODERATE ONSHORE WINDS THIS AFTERNOON. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PT REYES 0-10 NM FROM NOON SCA...PT REYES TO PIGEON PT 0-10 NM FROM NOON SCA...PIGEON PT TO PT PINOS 0-10 NM FROM NOON SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 3 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL NOON GLW...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM NOON SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM SCA...SF BAY FROM NOON SCA...MRY BAY FROM NOON && $$ PUBLIC FORECAST: SIMS AVIATION/MARINE: RILEY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
441 AM PDT WED JUN 19 2013 .DISCUSSION...AS OF 03:45 AM PDT WEDNESDAY...500MB LOW PRESSURE CENTER NEARING THE OREGON COAST THIS MORNING WITH ASSOCIATED TROUGH AXIS POSITIONED ACROSS MUCH OF CALIFORNIA. IN ADDITION...THE STRATUS FORMATION HAS BEEN LIMITED THIS MORNING ACROSS THE REGION. EXPECTING WARMER TEMPERATURES THIS AFTERNOON AS THE TROUGH PUSHES FURTHER INLAND. 850MB TEMPERATURES ALSO FORECAST TO WARM THROUGH THE UPCOMING WEEKEND AS A RIDGE BUILDS IN AS THE UPPER LEVEL LOW ONLY SLOWLY MOVES EASTWARD. AT THE SURFACE...NORTHWEST WINDS WILL PREVAIL AND KEEP TEMPERATURES FROM WARMING TOO MUCH THROUGH THE WEEKEND. FORECAST MODELS CONTINUE TO DIFFER IN THEIR SOLUTIONS FOR THE EARLY PART OF NEXT WEEK AS THE NEXT UPPER LEVEL TROUGH DEVELOPS. COULD SEE AN INCREASE IN DEEPER MOISTURE PUSH INTO THE REGION...ESPECIALLY ACROSS THE NORTH BAY WHERE RAIN CHANCES COULD INCREASE. HOWEVER...FOR NOW WILL KEEP MENTION OF PRECIPITATION OUT OF THE FORECAST AND FOLLOW MORE OF A PERSISTENT PATTERN. && .AVIATION...AS OF 4:40 AM PDT WEDNESDAY...EXTREMELY DIFFICULT FORECAST THIS MORNING AS NUMEROUS UPPER LEVEL IMPULSES MOVE EAST ACROSS THE AREA AROUND AN UPPER LOW OVER THE CA/OR BORDER. THIS UPPER LOW HAS CAUSED MANY PROBLEMS THE PAST FEW DAYS...WASHING OUT THE MARINE LAYER AND MAKING IT VERY DIFFICULT TO FORECAST STRATUS FORMATION AND DISSIPATION. PATCHY STRATUS DEVELOPED YESTERDAY EVENING AND CONTINUES TO SLOWLY EXPAND. MOST TERMINALS WILL SEE BRIEF MVFR TO IFR CIGS THROUGH 16Z. SHORT TERM MODELS INCLUDING THE HRRR AND THE LOCAL WRF INDICATE THAT VFR CONDITIONS WILL PREVAIL AFTER 16Z. LOW CONFIDENCE. OTHERWISE...MODERATE ONSHORE FLOW THIS AFTERNOON INTO THE EARLY EVENING HOURS. VICINITY OF KSFO...PATCHY MVFR CIGS WILL BE PRESENT NEAR THE TERMINAL THROUGH AT LEAST 16Z. VERY LOW CONFIDENCE. MODERATE TO STRONG WEST WINDS THIS AFTERNOON...WITH GUSTS TO JUST OVER 30 KT. KSFO BRIDGE APPROACH...PATCHY STRATUS IS MORE LIKELY TO IMPACT THE TERMINAL THROUGH 17Z. LOW CONFIDENCE. MONTEREY BAY AREA TERMINALS...PATCHY MVFR TO IFR CIGS THROUGH 16Z. LOW CONFIDENCE. MODERATE ONSHORE WINDS THIS AFTERNOON. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PT REYES 0-10 NM FROM NOON SCA...PT REYES TO PIGEON PT 0-10 NM FROM NOON SCA...PIGEON PT TO PT PINOS 0-10 NM FROM NOON SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 3 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL NOON GLW...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM NOON SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM SCA...SF BAY FROM NOON SCA...MRY BAY FROM NOON && $$ PUBLIC FORECAST: RGASS AVIATION/MARINE: RILEY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
312 PM MDT WED JUN 19 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 311 PM MDT WED JUN 19 2013 ..POSSIBLE ISOLATED SEVERE TONIGHT...CRITICAL FIRE WEATHER CONDITIONS THURSDAY... MAIN CONCERN IN THE SHORT TERM IS THE POTENTIAL FOR THUNDERSTORMS...POSSIBLY SEVERE...ALONG AND EAST OF THE DRY LINE THIS AFTERNOON AND EVENING. CURRENT SPC MESO ANALYSIS SHOWS 3 TO 4 THOUSAND J/KG OF SBCAPE AND 40KT 0-6KM BULK SHEAR ACROSS THE EASTERN PLAINS WITH LITTLE CIN. THE LATEST HRRR AND RAP TRY TO INITIATE A FEW CELLS IN THIS AREA BETWEEN 22Z AND 01Z TONIGHT. ANY STORM THAT IS ABLE TO INITIATE WILL HAVE A GOOD CHANCE OF PRODUCING LARGE HAIL. THE LATEST HRRR AND RAP ALSO PUSH THE DRYLINE SLIGHTLY FARTHER WEST INTO EXTREME EASTERN PUEBLO AND EL PASO COUNTIES AS WELL AS CENTRAL LAS ANIMAS COUNTY. I HAVE INCREASED POPS TO ISOLATED IN THESE AREAS. OVER THE REST OF THE REGION...DEWPOINTS WERE QUICK TO DROP WEST OF THE INTERSTATE INTO THE SINGLE DIGITS THIS MORNING...AND ARE SLOWLY DROPPING ALONG THE I-25 CORRIDOR AS WINDS CONTINUE TO INCREASE IN THESE AREAS. THE CURRENT RED FLAG WARNING LOOKS GOOD AND WILL LEAVE IT INTACT. THURSDAY... THE FORECAST AREA WILL REMAIN BETWEEN A QUASISTATIONARY CUT OFF LOW CENTERED OVER IDAHO AND A BROAD RIDGE OF HIGH PRESSURE CENTERED OVER TEXAS. THE RESULTING SOUTHWEST FLOW WILL RESULT IN CRITICAL FIRE WEATHER CONDITIONS ACROSS THE I-25 CORRIDOR AND AREAS WESTWARD. GUSTY WINDS...LOW DEWPOINTS...AND DRY FUELS WILL PROMOTE EXTREME FIRE GROWTH IN THESE AREAS. A RED FLAG WARNING HAS BEEN ISSUED BEGINNING AT 11AM FOR THESE AREA. THE NAM12/GFS INDICATE THE DRYLINE WILL STILL BE IN SOUTHEASTERN COLORADO THURSDAY AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE IN BACA COUNTY. IF THE DRYLINE SETS UP FARTHER WESTWARD THAN CURRENTLY INDICATED...ADDITIONAL COUNTIES WILL NEED TO BE WATCHED FOR STORM INITIATION LATE THURSDAY AFTERNOON. -PJC .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 311 PM MDT WED JUN 19 2013 ...CRITICAL FIRE WEATHER CONDITIONS CONTINUE THROUGH THE WEEKEND INTO EARLY NEXT WEEK... SOUTHWEST FLOW WILL REMAIN OVER THE REGION THROUGH THE WEEKEND WITH A REPEAT PERFORMANCE OF CRITICAL FIRE WEATHER CONDITIONS POSSIBLE AGAIN FOR FRIDAY. THIS LOOKS MOST LIKELY TO OCCUR ACROSS THE MOUNTAINS AND VALLEYS AND SOUTHERN I-25 CORRIDOR. IT GETS A LITTLE TRICKIER FOR NORTHERN PORTIONS OF THE I-25 CORRIDOR...MAINLY PUEBLO...EL PASO...AND TELLER COUNTIES...WITH WIND GUSTS POSSIBLY COMING UP JUST SHY OF 25 MPH FOR THE REQUIRED 3 HOUR WINDOW. HOWEVER WINDS LOOK A LITTLE STRONGER ON THE GFS SO WILL GO AHEAD AND INCLUDE THESE AREAS IN THE FIRE WEATHER WATCH. WITH TEMPERATURES PUSHING 100 ACROSS THE PLAINS...WITH GENERALLY 60S/70S AND 80S ACROSS THE MTS/VALLEYS...RHS ALL AREAS DROP TO BETWEEN 5 AND 15 PERCENT. FUELS ARE STILL TOO MOIST OR HAVE GREENED UP ACROSS THE SOUTHEAST PLAINS EAST OF THE I-25 CORRIDOR WITH RECENT RAINFALL SO NO HIGHLIGHTS ANTICIPATED FOR THEM AT THIS TIME. A SIMILAR SCENARIO IS EXPECTED FOR SATURDAY THOUGH SOUTHERLY WINDS ADVECT HIGHER DEW POINTS INTO THE SOUTHEAST CORNER OF THE STATE. ISOLATED THUNDERSTORMS WILL BE POSSIBLE NEAR THE CO/KS BORDER ALONG THIS DRY LINE. ELSEWHERE...LOOKS LIKE ANOTHER POTENTIAL RED FLAG DAY. DRY AND WINDY CONDITIONS CONTINUE FOR SUNDAY AND MONDAY WITH CRITICAL FIRE WEATHER CONDITIONS LIKELY TO CONTINUE FOR THE I-25 CORRIDOR AND POINTS WESTWARD THROUGH THE PERIOD. IF FUELS DRY OUT SUFFICIENTLY...ITS POSSIBLE MORE OF THE SOUTHEAST PLAINS MAY NEED TO BE INCLUDED. CHANCES FOR PRECIPITATION LOOK VERY LOW...THOUGH ECMWF HAS THE DRY LINE FLIRTING WITH THE EASTERN BORDER. UPPER RIDGE BUILDS OVER THE AREA FOR TUESDAY AND WEDNESDAY. ALTHOUGH IT WILL REMAIN HOT AND DRY...THIS DOES HELP TO TAPER BACK WINDS WHICH WILL ALLEVIATE THE CRITICAL FIRE WEATHER CONDITIONS SOME. -KT && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 311 PM MDT WED JUN 19 2013 VFR CONDITIONS ARE EXPECTED AT KALS...KCOS...AND KPUB THROUGH THURSDAY AFTERNOON. THE WINDS AT ALL THREE SITES WILL BEGIN TO WEAKEN AFTER SUNSET TONIGHT AND INCREASE AGAIN AT OR AROUND 17Z THURSDAY MORNING. -PJC && .FIRE WEATHER... ISSUED AT 311 PM MDT WED JUN 19 2013 CRITICAL CONDITIONS FOR FIRE WEATHER WILL CONTINUE FOR THURSDAY THROUGH MONDAY AS A PROLONGED HOT DRY AND WINDY PATTERN SETS UP OVER THE DISTRICT. CONDITIONS WILL BE MOST VOLATILE ACROSS THE MOUNTAIN AREAS...PARTICULARLY ACROSS THE SOUTHWEST AND CENTRAL MOUNTAINS AND SAN LUIS VALLEY. CRITICAL FIRE WEATHER CONDITIONS MAY BE A BIT MARGINAL FOR THE PIKES PEAK REGION ON FRIDAY...HOWEVER WINDS APPEAR TO STRENGTHEN ACROSS ALL OF THE AREA FOR SATURDAY THROUGH MONDAY. HUMIDITIES WILL DROP TO BETWEEN 5 AND 15 PERCENT EACH AFTERNOON AND WITH HAINES VALUES RUNNING AROUND 6...WHICH WILL LEAD TO CONDITIONS FAVORABLE FOR PLUME DOMINATED FIRES THROUGH THE PERIOD. ALTHOUGH FUELS ARE NOT CONSIDERED CRITICAL EAST OF THE I-25 CORRIDOR...HOT DRY CONDITIONS MAY CURE FUELS AND MAKE THEM RECEPTIVE AGAIN OVER THE WEEKEND...THUS EXTREME CARE SHOULD BE TAKEN TO AVOID WILDFIRE STARTS THROUGH THIS HOT DRY PERIOD ACROSS ALL OF SOUTH CENTRAL AND SOUTHEAST COLORADO. WINDS ARE EXPECTED TO WEAKEN SOME FOR TUESDAY AS HIGH PRESSURE BUILDS OVER THE REGION...HOWEVER IT IS LIKELY TO REMAIN HOT AND DRY NONE-THE-LESS. -KT/PJC && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ220>230. RED FLAG WARNING FROM 11 AM TO 8 PM MDT THURSDAY FOR COZ220>230. FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR COZ220>230. && $$ SHORT TERM...PJC LONG TERM...KT AVIATION...PJC FIRE WEATHER...PJC/KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1116 AM MDT WED JUN 19 2013 .UPDATE... ISSUED AT 857 AM MDT WED JUN 19 2013 UPDATED GRIDS FOR CURRENT TEMPERATURE TRENDS AND SKY CONDITIONS. ALSO REFRESHED ALL FIRE WEATHER GRIDS WITH 12Z NAM12 DATA. -PJC && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM MDT WED JUN 19 2013 ...ISOLATED SEVERE THREAT FAR EASTERN PLAINS...FIRE WEATHER OVER MTNS/VALLEYS... CURRENTLY... AN ISOLATED STRONG TO SEVERE STORM HAS BEEN TRACKING OVER THE FAR SOUTHEAST PLAINS EARLY THIS MORNING. STORM HAS TRACKED IN REMOTE AREAS SO NO REPORTS...BUT ALGORITHMS HAVE BEEN INDICATING 2" HAIL WITH IT AT TIMES...AND MODEST ROTATION HAS BEEN OCCURRING ON AND OFF WITH THE CELL. OVER THE REST OF THE PLAINS...LLVL MSTR HAS REMAINED IN PLACE WITH SFC SE WINDS OVER THE REGION. SKIES HAVE CLOUDED UP OVER A GOOD PART OF THE PLAINS WITH CIGS IN THE MVFR/IFR CATEGORY. OVER THE INTERIOR MTNS...THE DRY AIR IS NOTED AS DWPTS ARE IN THE SINGLE DIGITS ACROSS THE SAN JUANS. TODAY... SIMULATIONS SHOW THE DRYLINE WILL REMAIN ON THE COLORADO SIDE OF THE CO/KS BORDER THIS AFTERNOON. ALTHOUGH TEMPS WILL BE WARMING ALOFT...CONVG ALONG THE BOUNDARY MAY ALLOW FOR ONE OR TWO STORMS TO FORM. LATEST HRRR WAS HINTING AT THIS. SPC ALSO HAS FAR E PLAINS IN SLIGHT RISK. CAPE IS FCST TO BE SIGNIFICANT...3000 J/KG...AND SHEAR WILL BE IN THE 35-45 KT RANGE...SO IF ANY STORM GOES UP IT WILL ROTATE AND IT WILL HAVE THE POTENTIAL TO PRODUCE SOME BIG HAIL. LCLS WILL BE HIGH SO TORNADO THREAT IS VERY LOW. OVER THE REST OF THE REGION...METEOROLOGICAL CONDITIONS WILL BE FAVORABLE FOR EXTREME FIRE BEHAVIOR GIVEN THE LOW DWPTS AND GUSTY SW WINDS. QUITE A FEW AREAS ON THE PLAINS HAVE RECEIVED SOME BENEFICIAL RAIN SO THE THREAT IS LESS ALONG THE I-25 CORRIDOR...HOWEVER IT WILL DRY OUT QUICKLY TODAY AND ANY AREAS WHICH HAVE NOT RECEIVED ANY SIGNIF RAIN WILL HAVE THE POTENTIAL FOR EXTREME FIRE BEHAVIOR. IT WILL BE MUCH WARMER TODAY THAN THE YESTERDAY...WITH HIGHS APPROACHING 100 OVER THE LOWER ARK RVR VALLEY. EXPECT 70S MTNS WITH 80S IN THE VALLEYS. TEMPS AROUND 90F WILL OCCUR IN MOST OF EL PASO COUNTY. TONIGHT... EXCEPT FOR THE SLIGHT CHANCE OF A SUPERCELL OVER THE FAR E PLAINS EARLY THIS EVENING...IT WILL BE DRY. RH RECOVERY WILL BE VERY POOR OVER THE MTNS...VALLEYS AND I-25 CORRIDOR REGION. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 323 AM MDT WED JUN 19 2013 ...HIGH FIRE DANGER... MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED WITH A SLOW MOVING SYSTEM OUT OF THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS AND PERSISTENT SOUTHWESTERLY FLOW ACROSS THE ROCKIES. THIS WILL PUT THE REGION UNDER FAVORABLE CONDITIONS FOR HIGH FIRE DANGER. THURSDAY THROUGH SATURDAY...STRONG DRY PERSISTENT SOUTHWESTERLY FLOW WILL ENCOMPASS SOUTHERN COLORADO THROUGH THIS PERIOD. THIS WILL SET THE STAGE FOR EXTREME FIRE DANGER FOR MUCH OF SOUTHERN COLORADO...ESPECIALLY WEST OF I-25. ALREADY HAVE A FIRE WEATHER WATCH OUT FOR THURSDAY AFTERNOON...AND WILL LIKELY NEED TO RAISE ONE FOR FRIDAY AFTERNOON AS WELL IN THE NEAR FUTURE. WIDESPREAD WINDS OF 20 TO 30 MPH ARE EXPECTED EACH AFTERNOON THROUGH SATURDAY WHILE HUMIDITY VALUES WILL DROP WELL BELOW 10 PERCENT. IN ADDITION THE AFTERNOON MIXING WILL ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 90S TO LOWER 100S ACROSS THE PLAINS. THERE ARE SOME FIRE WEATHER CONCERNS EAST OF I-25 AS WELL...CONDITIONS WILL BE FAVORABLE HOWEVER FUEL STATUS AND RECENT HEAVY RAINS PRECLUDE ANY FIRE WEATHER HIGHLIGHTS AT THIS TIME. FINE FUELS WILL NEED TO BE WATCHED AND MAY CURE QUICKLY WITH PERSISTENT DRY AND WINDY CONDITIONS LEADING TO ENHANCED FIRE DANGER. THE ONLY AREA THAT MAY SEE ANY PRECIPITATION DURING THE EXTENDED PERIOD WILL BE THE FAR SOUTHEAST PLAINS ON FRIDAY AFTERNOON AND EVENING WHERE AN ISOLATED THUNDERSTORM WILL BE POSSIBLE...BUT CONFIDENCE IS LOW IN OCCURRENCE AT THIS TIME. SUNDAY THROUGH TUESDAY...THE UPPER PATTERN BEGINS TO SHIFT ON SUNDAY WITH THE UPPER SYSTEM OVER THE NORTHERN PLAINS EJECTING INTO THE GREAT LAKES AND HIGH PRESSURE BUILDING NORTHWARD OUT OF THE DESERT SOUTHWEST. TEMPERATURES MAY BE SLIGHTLY COOLER ON SUNDAY BEHIND A WEAK COLD FRONT...BUT WE SHOULD STILL MANAGE MID TO UPPER 90S ACROSS THE PLAINS BEFORE WARMING BACK UP FOR MONDAY AND TUESDAY. HUMIDITY VALUES WILL REMAIN LOW THROUGH THIS PERIOD...BUT WITH HIGH PRESSURE BUILDING OVERHEAD...WINDS SHOULD WEAKEN AND HELP REDUCE THE HIGH FIRE DANGER. THE EXCEPTION MAY BE THE CONTINENTAL DIVIDE AREA SUNDAY AND MONDAY WHERE SOUTHWESTERLY FLOW WILL REMAIN A BIT STRONGER BEFORE WEAKENING ON TUESDAY. THIS WILL NEED TO BE MONITORED. CURRENT MODEL PROJECTIONS INDICATING THAT WE WILL REMAIN DRY WITH NO CHANCES FOR PRECIPITATION EARLY TO MIDDLE NEXT WEEK. MOZLEY && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1108 AM MDT WED JUN 19 2013 VFR CONDITIONS ARE EXPECTED AT KALS...KCOS...AND KPUB THROUGH 18Z THURSDAY. THE MAIN CONCERN AT THESE SITES WILL BE GUSTY SOUTHWEST WINDS LATE THIS MORNING THROUGH THIS EVENING. -PJC && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ220>230. FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR COZ220>230. && $$ UPDATE...PJC SHORT TERM...HODANISH LONG TERM...MOZLEY AVIATION...PJC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
906 AM MDT WED JUN 19 2013 .UPDATE... ISSUED AT 857 AM MDT WED JUN 19 2013 UPDATED GRIDS FOR CURRENT TEMPERATURE TRENDS AND SKY CONDITIONS. ALSO REFRESHED ALL FIRE WEATHER GRIDS WITH 12Z NAM12 DATA. -PJC && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM MDT WED JUN 19 2013 ...ISOLATED SEVERE THREAT FAR EASTERN PLAINS...FIRE WEATHER OVER MTNS/VALLEYS... CURRENTLY... AN ISOLATED STRONG TO SEVERE STORM HAS BEEN TRACKING OVER THE FAR SOUTHEAST PLAINS EARLY THIS MORNING. STORM HAS TRACKED IN REMOTE AREAS SO NO REPORTS...BUT ALGORITHMS HAVE BEEN INDICATING 2" HAIL WITH IT AT TIMES...AND MODEST ROTATION HAS BEEN OCCURRING ON AND OFF WITH THE CELL. OVER THE REST OF THE PLAINS...LLVL MSTR HAS REMAINED IN PLACE WITH SFC SE WINDS OVER THE REGION. SKIES HAVE CLOUDED UP OVER A GOOD PART OF THE PLAINS WITH CIGS IN THE MVFR/IFR CATEGORY. OVER THE INTERIOR MTNS...THE DRY AIR IS NOTED AS DWPTS ARE IN THE SINGLE DIGITS ACROSS THE SAN JUANS. TODAY... SIMULATIONS SHOW THE DRYLINE WILL REMAIN ON THE COLORADO SIDE OF THE CO/KS BORDER THIS AFTERNOON. ALTHOUGH TEMPS WILL BE WARMING ALOFT...CONVG ALONG THE BOUNDARY MAY ALLOW FOR ONE OR TWO STORMS TO FORM. LATEST HRRR WAS HINTING AT THIS. SPC ALSO HAS FAR E PLAINS IN SLIGHT RISK. CAPE IS FCST TO BE SIGNIFICANT...3000 J/KG...AND SHEAR WILL BE IN THE 35-45 KT RANGE...SO IF ANY STORM GOES UP IT WILL ROTATE AND IT WILL HAVE THE POTENTIAL TO PRODUCE SOME BIG HAIL. LCLS WILL BE HIGH SO TORNADO THREAT IS VERY LOW. OVER THE REST OF THE REGION...METEOROLOGICAL CONDITIONS WILL BE FAVORABLE FOR EXTREME FIRE BEHAVIOR GIVEN THE LOW DWPTS AND GUSTY SW WINDS. QUITE A FEW AREAS ON THE PLAINS HAVE RECEIVED SOME BENEFICIAL RAIN SO THE THREAT IS LESS ALONG THE I-25 CORRIDOR...HOWEVER IT WILL DRY OUT QUICKLY TODAY AND ANY AREAS WHICH HAVE NOT RECEIVED ANY SIGNIF RAIN WILL HAVE THE POTENTIAL FOR EXTREME FIRE BEHAVIOR. IT WILL BE MUCH WARMER TODAY THAN THE YESTERDAY...WITH HIGHS APPROACHING 100 OVER THE LOWER ARK RVR VALLEY. EXPECT 70S MTNS WITH 80S IN THE VALLEYS. TEMPS AROUND 90F WILL OCCUR IN MOST OF EL PASO COUNTY. TONIGHT... EXCEPT FOR THE SLIGHT CHANCE OF A SUPERCELL OVER THE FAR E PLAINS EARLY THIS EVENING...IT WILL BE DRY. RH RECOVERY WILL BE VERY POOR OVER THE MTNS...VALLEYS AND I-25 CORRIDOR REGION. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 323 AM MDT WED JUN 19 2013 ...HIGH FIRE DANGER... MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED WITH A SLOW MOVING SYSTEM OUT OF THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS AND PERSISTENT SOUTHWESTERLY FLOW ACROSS THE ROCKIES. THIS WILL PUT THE REGION UNDER FAVORABLE CONDITIONS FOR HIGH FIRE DANGER. THURSDAY THROUGH SATURDAY...STRONG DRY PERSISTENT SOUTHWESTERLY FLOW WILL ENCOMPASS SOUTHERN COLORADO THROUGH THIS PERIOD. THIS WILL SET THE STAGE FOR EXTREME FIRE DANGER FOR MUCH OF SOUTHERN COLORADO...ESPECIALLY WEST OF I-25. ALREADY HAVE A FIRE WEATHER WATCH OUT FOR THURSDAY AFTERNOON...AND WILL LIKELY NEED TO RAISE ONE FOR FRIDAY AFTERNOON AS WELL IN THE NEAR FUTURE. WIDESPREAD WINDS OF 20 TO 30 MPH ARE EXPECTED EACH AFTERNOON THROUGH SATURDAY WHILE HUMIDITY VALUES WILL DROP WELL BELOW 10 PERCENT. IN ADDITION THE AFTERNOON MIXING WILL ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 90S TO LOWER 100S ACROSS THE PLAINS. THERE ARE SOME FIRE WEATHER CONCERNS EAST OF I-25 AS WELL...CONDITIONS WILL BE FAVORABLE HOWEVER FUEL STATUS AND RECENT HEAVY RAINS PRECLUDE ANY FIRE WEATHER HIGHLIGHTS AT THIS TIME. FINE FUELS WILL NEED TO BE WATCHED AND MAY CURE QUICKLY WITH PERSISTENT DRY AND WINDY CONDITIONS LEADING TO ENHANCED FIRE DANGER. THE ONLY AREA THAT MAY SEE ANY PRECIPITATION DURING THE EXTENDED PERIOD WILL BE THE FAR SOUTHEAST PLAINS ON FRIDAY AFTERNOON AND EVENING WHERE AN ISOLATED THUNDERSTORM WILL BE POSSIBLE...BUT CONFIDENCE IS LOW IN OCCURRENCE AT THIS TIME. SUNDAY THROUGH TUESDAY...THE UPPER PATTERN BEGINS TO SHIFT ON SUNDAY WITH THE UPPER SYSTEM OVER THE NORTHERN PLAINS EJECTING INTO THE GREAT LAKES AND HIGH PRESSURE BUILDING NORTHWARD OUT OF THE DESERT SOUTHWEST. TEMPERATURES MAY BE SLIGHTLY COOLER ON SUNDAY BEHIND A WEAK COLD FRONT...BUT WE SHOULD STILL MANAGE MID TO UPPER 90S ACROSS THE PLAINS BEFORE WARMING BACK UP FOR MONDAY AND TUESDAY. HUMIDITY VALUES WILL REMAIN LOW THROUGH THIS PERIOD...BUT WITH HIGH PRESSURE BUILDING OVERHEAD...WINDS SHOULD WEAKEN AND HELP REDUCE THE HIGH FIRE DANGER. THE EXCEPTION MAY BE THE CONTINENTAL DIVIDE AREA SUNDAY AND MONDAY WHERE SOUTHWESTERLY FLOW WILL REMAIN A BIT STRONGER BEFORE WEAKENING ON TUESDAY. THIS WILL NEED TO BE MONITORED. CURRENT MODEL PROJECTIONS INDICATING THAT WE WILL REMAIN DRY WITH NO CHANCES FOR PRECIPITATION EARLY TO MIDDLE NEXT WEEK. MOZLEY && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 323 AM MDT WED JUN 19 2013 MORNING LOW CIGS WILL AFFECT KCOS AND KPUB THROUGH ABOUT 14Z WITH VFR THROUGH THE REMAINDER OF THE VALID TAF PERIOD. KALS WILL BE VFR NEXT 24H. GUSTY SOUTHWEST WINDS WILL OCCUR AT ALL TAF SITES THIS AFTERNOON...WITH WIND GUSTS IN THE 20 TO 30 KT RANGE. && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ220>230. FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR COZ220>230. && $$ UPDATE...PJC SHORT TERM...HODANISH LONG TERM...MOZLEY AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
347 AM MDT WED JUN 19 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM MDT WED JUN 19 2013 ...ISOLATED SEVERE THREAT FAR EASTERN PLAINS...FIRE WEATHER OVER MTNS/VALLEYS... CURRENTLY... AN ISOLATED STRONG TO SEVERE STORM HAS BEEN TRACKING OVER THE FAR SOUTHEAST PLAINS EARLY THIS MORNING. STORM HAS TRACKED IN REMOTE AREAS SO NO REPORTS...BUT ALGORITHMS HAVE BEEN INDICATING 2" HAIL WITH IT AT TIMES...AND MODEST ROTATION HAS BEEN OCCURRING ON AND OFF WITH THE CELL. OVER THE REST OF THE PLAINS...LLVL MSTR HAS REMAINED IN PLACE WITH SFC SE WINDS OVER THE REGION. SKIES HAVE CLOUDED UP OVER A GOOD PART OF THE PLAINS WITH CIGS IN THE MVFR/IFR CATEGORY. OVER THE INTERIOR MTNS...THE DRY AIR IS NOTED AS DWPTS ARE IN THE SINGLE DIGITS ACROSS THE SAN JUANS. TODAY... SIMULATIONS SHOW THE DRYLINE WILL REMAIN ON THE COLORADO SIDE OF THE CO/KS BORDER THIS AFTERNOON. ALTHOUGH TEMPS WILL BE WARMING ALOFT...CONVG ALONG THE BOUNDARY MAY ALLOW FOR ONE OR TWO STORMS TO FORM. LATEST HRRR WAS HINTING AT THIS. SPC ALSO HAS FAR E PLAINS IN SLIGHT RISK. CAPE IS FCST TO BE SIGNIFICANT...3000 J/KG...AND SHEAR WILL BE IN THE 35-45 KT RANGE...SO IF ANY STORM GOES UP IT WILL ROTATE AND IT WILL HAVE THE POTENTIAL TO PRODUCE SOME BIG HAIL. LCLS WILL BE HIGH SO TORNADO THREAT IS VERY LOW. OVER THE REST OF THE REGION...METEOROLOGICAL CONDITIONS WILL BE FAVORABLE FOR EXTREME FIRE BEHAVIOR GIVEN THE LOW DWPTS AND GUSTY SW WINDS. QUITE A FEW AREAS ON THE PLAINS HAVE RECEIVED SOME BENEFICIAL RAIN SO THE THREAT IS LESS ALONG THE I-25 CORRIDOR...HOWEVER IT WILL DRY OUT QUICKLY TODAY AND ANY AREAS WHICH HAVE NOT RECEIVED ANY SIGNIF RAIN WILL HAVE THE POTENTIAL FOR EXTREME FIRE BEHAVIOR. IT WILL BE MUCH WARMER TODAY THAN THE YESTERDAY...WITH HIGHS APPROACHING 100 OVER THE LOWER ARK RVR VALLEY. EXPECT 70S MTNS WITH 80S IN THE VALLEYS. TEMPS AROUND 90F WILL OCCUR IN MOST OF EL PASO COUNTY. TONIGHT... EXCEPT FOR THE SLIGHT CHANCE OF A SUPERCELL OVER THE FAR E PLAINS EARLY THIS EVENING...IT WILL BE DRY. RH RECOVERY WILL BE VERY POOR OVER THE MTNS...VALLEYS AND I-25 CORRIDOR REGION. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 323 AM MDT WED JUN 19 2013 ...HIGH FIRE DANGER... MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED WITH A SLOW MOVING SYSTEM OUT OF THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS AND PERSISTENT SOUTHWESTERLY FLOW ACROSS THE ROCKIES. THIS WILL PUT THE REGION UNDER FAVORABLE CONDITIONS FOR HIGH FIRE DANGER. THURSDAY THROUGH SATURDAY...STRONG DRY PERSISTENT SOUTHWESTERLY FLOW WILL ENCOMPASS SOUTHERN COLORADO THROUGH THIS PERIOD. THIS WILL SET THE STAGE FOR EXTREME FIRE DANGER FOR MUCH OF SOUTHERN COLORADO...ESPECIALLY WEST OF I-25. ALREADY HAVE A FIRE WEATHER WATCH OUT FOR THURSDAY AFTERNOON...AND WILL LIKELY NEED TO RAISE ONE FOR FRIDAY AFTERNOON AS WELL IN THE NEAR FUTURE. WIDESPREAD WINDS OF 20 TO 30 MPH ARE EXPECTED EACH AFTERNOON THROUGH SATURDAY WHILE HUMIDITY VALUES WILL DROP WELL BELOW 10 PERCENT. IN ADDITION THE AFTERNOON MIXING WILL ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 90S TO LOWER 100S ACROSS THE PLAINS. THERE ARE SOME FIRE WEATHER CONCERNS EAST OF I-25 AS WELL...CONDITIONS WILL BE FAVORABLE HOWEVER FUEL STATUS AND RECENT HEAVY RAINS PRECLUDE ANY FIRE WEATHER HIGHLIGHTS AT THIS TIME. FINE FUELS WILL NEED TO BE WATCHED AND MAY CURE QUICKLY WITH PERSISTENT DRY AND WINDY CONDITIONS LEADING TO ENHANCED FIRE DANGER. THE ONLY AREA THAT MAY SEE ANY PRECIPITATION DURING THE EXTENDED PERIOD WILL BE THE FAR SOUTHEAST PLAINS ON FRIDAY AFTERNOON AND EVENING WHERE AN ISOLATED THUNDERSTORM WILL BE POSSIBLE...BUT CONFIDENCE IS LOW IN OCCURRENCE AT THIS TIME. SUNDAY THROUGH TUESDAY...THE UPPER PATTERN BEGINS TO SHIFT ON SUNDAY WITH THE UPPER SYSTEM OVER THE NORTHERN PLAINS EJECTING INTO THE GREAT LAKES AND HIGH PRESSURE BUILDING NORTHWARD OUT OF THE DESERT SOUTHWEST. TEMPERATURES MAY BE SLIGHTLY COOLER ON SUNDAY BEHIND A WEAK COLD FRONT...BUT WE SHOULD STILL MANAGE MID TO UPPER 90S ACROSS THE PLAINS BEFORE WARMING BACK UP FOR MONDAY AND TUESDAY. HUMIDITY VALUES WILL REMAIN LOW THROUGH THIS PERIOD...BUT WITH HIGH PRESSURE BUILDING OVERHEAD...WINDS SHOULD WEAKEN AND HELP REDUCE THE HIGH FIRE DANGER. THE EXCEPTION MAY BE THE CONTINENTAL DIVIDE AREA SUNDAY AND MONDAY WHERE SOUTHWESTERLY FLOW WILL REMAIN A BIT STRONGER BEFORE WEAKENING ON TUESDAY. THIS WILL NEED TO BE MONITORED. CURRENT MODEL PROJECTIONS INDICATING THAT WE WILL REMAIN DRY WITH NO CHANCES FOR PRECIPITATION EARLY TO MIDDLE NEXT WEEK. MOZLEY && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 323 AM MDT WED JUN 19 2013 MORNING LOW CIGS WILL AFFECT KCOS AND KPUB THROUGH ABOUT 14Z WITH VFR THROUGH THE REMAINDER OF THE VALID TAF PERIOD. KALS WILL BE VFR NEXT 24H. GUSTY SOUTHWEST WINDS WILL OCCUR AT ALL TAF SITES THIS AFTERNOON...WITH WIND GUSTS IN THE 20 TO 30 KT RANGE. && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM THIS MORNING TO 8 PM MDT THIS EVENING FOR COZ220>230. FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR COZ220>230. && $$ SHORT TERM...HODANISH LONG TERM...MOZLEY AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS NEW YORK NY
157 PM EDT WED JUN 19 2013 .SYNOPSIS... HIGH PRESSURE BUILDS IN FROM THE NORTHWEST TODAY AND REMAINS IN CONTROL THROUGH THE END OF THE WEEK. A WEAK COLD FRONT WILL PASS THROUGH THE AREA SUNDAY NIGHT INTO MONDAY WITH HIGH PRESSURE RETURNING IN ITS WAKE. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 16Z SURFACE ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO THE TRI- STATE AREA. LAST SEVERAL HOURS OF RAP ANALYSIS AT H500 INDICATE A SHORTWAVE TROUGH AND WEAK VORT MAX MOVING THROUGH...THERE WILL BE LITTLE CONSEQUENCE FROM THIS FEATURE. LIGHT NORTH TO NORTHEASTERLY FLOW WILL CONTINUE INTO THE AFTERNOON WITH JUST A FEW FAIR WEATHER CLOUDS. LATE AFTERNOON SEA BREEZES ARE EXPECTED AT THE COAST. OTHERWISE...MOSTLY SUNNY WITH A DRY AIRMASS AS SURFACE DEWPOINTS DROP INTO THE 40S. MIXING PROFILES SUPPORT HIGHS OF MOSTLY 75-80. THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... LIGHT TO CALM WINDS AND A MOSTLY CLEAR SKY TONIGHT WILL ALLOW FOR DECENT RADIATIONAL COOLING OUTSIDE OF THE CITY...WITH LOWS 5-10 DEGREES BELOW NORMAL IN MOST OF THE SUBURBS. HIGH PRESSURE CENTER SHIFTS OFFSHORE ON THURSDAY WITH A RETURN SW-S FLOW SETTING UP. SEA BREEZES ARE LIKELY AS WINDS REMAIN LIGHT THROUGH THE FIRST FEW THOUSAND FEET IN ELEVATION. SURFACE DEW POINTS SHOULD REMAIN AT COMFORTABLE LEVELS IN SPITE OF THIS AS DRIER AIR FROM ALOFT MIXES DOWN. MIXING WON/T BE AS DEEP AS TODAY DUE TO SUBSIDENCE...HOWEVER TEMPERATURES AT THE TOP OF THE MIXED LAYER SHOULD ALLOW FOR HIGHS OF GENERALLY 75-80 ONCE AGAIN. DRY WEATHER CONTINUES INTO THURSDAY NIGHT WITH LOWS STILL BELOW NORMAL...BUT NOT AS COOL AS TONIGHT. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... GLOBAL MODELS IN GOOD AGREEMENT WITH THE OVERALL PATTERN IN THE LONG TERM TIME FRAME. ALOFT...A MEAN TROUGH WILL GIVE WAY TO SLIGHTLY RISING HEIGHTS BY SATURDAY AND CONTINUING TO BUILD THROUGH THE WEEK. GFS IS SLIGHTLY MORE AGGRESSIVE WITH THE STRONG RIDGE MOVING IN WHILE THE ECMWF TRACKS A SHORTWAVE THROUGH MONDAY AND THEN QUICKLY RISES THE HEIGHTS. AT THE SURFACE... HIGH PRESSURE REMAINS IN CONTROL THROUGH THE LONG TERM WITH A GENERAL SOUTH-SOUTHWEST FLOW. USED A MAV/MET BLEND FOR TEMPS ON FRIDAY WITH A GOOD GENERAL AGREEMENT FOR NEAR NORMAL VALUES. TEMPS WILL CONTINUE TO MODERATE THROUGH THE WEEK AND USED WPC GUIDANCE AS IT SEEMED REASONABLE WITH NO MAJOR TEMPERATURE FLUXES. NEAR TO JUST ABOVE NORMAL TEMPS ARE EXPECTED. MODELS TRYING TO HINT AT A FEW SHOWERS ON FRIDAY BUT HAVE CONTINUED THE DRY FORECAST WITH LITTLE INSTABILITY OR LIFT. ON SATURDAY...A COLD FRONT WILL WEAKEN AND DISSIPATE BY THE TIME IT REACHES THE WESTERN CWA BOUNDARY. WITH SOME INSTABILITY IN PLACE WITH AFTERNOON HEATING...THIS BOUNDARY COULD CREATE A FEW SHOWERS...MOSTLY IN FAR NORTH AND WEST ZONES. HAVE LEFT CHANCE POPS FOR THAT AREA. HIGHEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE SUNDAY NIGHT INTO MONDAY AS A COLD FRONT APPROACHES AND POSSIBLY REMAINING STATIONARY THROUGH MONDAY. ECMWF ALSO TRYING TO HINT AT A POTENTIAL DECAYING MCS TRACKING SE ALONG THE FRONT...ALONG THE SOUTHERN SIDE OF AN UPPER JET. WILL GENERALLY KEEP CHANCE POPS IN THE AREAS NORTH AND WEST OF NYC AND SLIGHT CHANCE ELSEWHERE. THE NORTHERN AREAS WILL HAVE THE HIGHEST INSTABILITY DURING THE DAY AND THEREFORE THE GREATEST PRECIP CHANCES. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... HIPRES BUILDS OVER THE REGION TNGT AND OFFSHORE ON THU. VFR THROUGH THE TAF PERIOD. N WINDS INTO THIS EVE EXCEPT WHERE SEA BREEZE FLOW DEVELOPS. GUST POTENTIAL WILL DECREASE THRU THE DAY AS WINDS ALOFT LIGHTEN. NEARLY CALM OVERNIGHT WITH SLY FLOW DEVELOPING AFT 12Z THU. ENHANCED FLOW ALONG THE S COASTS AFT 17-19Z THU...WITH SUSTAINED WINDS LIKELY TO BE AOA 15KT AT KJFK. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: VARIABILITY IN PREVAILING WIND DIRECTION POSSIBLE THRU 21Z AS GUST FREQUENCY DECREASES. SEA BREEZE EXPECTED TO DEVELOP DURING TAF TEMPO PERIOD. KLGA FCSTER COMMENTS: VARIABILITY IN PREVAILING WIND DIRECTION POSSIBLE THRU 23Z AS GUST FREQUENCY DECREASES. SEA BREEZE EXPECTED TO DEVELOP DURING TAF TEMPO PERIOD. KEWR FCSTER COMMENTS: VARIABILITY IN PREVAILING WIND DIRECTION POSSIBLE THRU 00Z AS GUST FREQUENCY DECREASES. SEA BREEZE EXPECTED TO DEVELOP DURING TAF TEMPO PERIOD. KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. KISP FCSTER COMMENTS: VARIABILITY IN PREVAILING WIND DIRECTION POSSIBLE THRU 22Z AS GUST FREQUENCY DECREASES. SEA BREEZE EXPECTED TO DEVELOP DURING TAF TEMPO PERIOD. .OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY... .THU-FRI...VFR. PREVAILING SW WINDS. .SAT-MON...MAINLY VFR. AREAS OF MVFR OR LWR IN THE MRNG. ISOLD-SCT AFTN/EVE TSTMS POSSIBLE...ESPECIALLY N AND W OF THE CITY. SW WINDS. && .MARINE... HIGH PRESSURE BUILDS IN OVER THE WATERS THROUGH THE DAY TODAY. A NORTHERLY FLOW AT AROUND 15 KT WEAKENS THIS AFTERNOON WITH LOCAL SEA BREEZE DIRECTIONS DEVELOPING NEARSHORE LATE IN THE DAY. A LIGHT RETURN S TO SW FLOW DEVELOPS FOR THURSDAY AS THE CENTER OF HIGH PRESSURE SHIFTS OFFSHORE. TRANQUIL CONDITIONS THEREFORE PREVAIL. WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH EARLY NEXT WEEK AS HIGH PRESSURE REMAINS OVER THE AREA. && .HYDROLOGY... DRY WEATHER IS EXPECTED THROUGH AT LEAST SUNDAY MORNING. SHOWERS AND THUNDERSTORMS ARE POSSIBLE EACH AFTERNOON SUN-TUE BUT NO WIDESPREAD SIGNIFICANT PRECIPITATION IS EXPECTED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JC/LN NEAR TERM...DS SHORT TERM...JC LONG TERM...LN AVIATION...JMC MARINE...JC/LN HYDROLOGY...JC/LN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1236 PM EDT WED JUN 19 2013 .SYNOPSIS... HIGH PRESSURE BUILDS IN FROM THE NORTHWEST TODAY AND REMAINS IN CONTROL THROUGH THE END OF THE WEEK. A WEAK COLD FRONT WILL PASS THROUGH THE AREA SUNDAY NIGHT INTO MONDAY WITH HIGH PRESSURE RETURNING IN ITS WAKE. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 16Z SURFACE ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO THE TRI- STATE AREA. LAST SEVERAL HUORS OF RAP ANALYSIS AT H500 INDICATE A SHORTWAVE TROUGH AND WEAK VORT MAX MOVING THROUGH...THERE WILL BE LITTLE CONSEQUENCE FROM THIS FEATURE. LIGHT NORTH TO NORTHEASTERLY FLOW WILL CONTINUE INTO THE AFTERNOON WITH JUST A FEW FAIR WEATHER CLOUDS. LATE AFTERNOON SEA BREEZES ARE EXPECTED AT THE COAST. OTHERWISE...MOSTLY SUNNY WITH A DRY AIRMASS AS SURFACE DEWPOINTS DROP INTO THE 40S. MIXING PROFILES SUPPORT HIGHS OF MOSTLY 75-80. THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... LIGHT TO CALM WINDS AND A MOSTLY CLEAR SKY TONIGHT WILL ALLOW FOR DECENT RADIATIONAL COOLING OUTSIDE OF THE CITY...WITH LOWS 5-10 DEGREES BELOW NORMAL IN MOST OF THE SUBURBS. HIGH PRESSURE CENTER SHIFTS OFFSHORE ON THURSDAY WITH A RETURN SW-S FLOW SETTING UP. SEA BREEZES ARE LIKELY AS WINDS REMAIN LIGHT THROUGH THE FIRST FEW THOUSAND FEET IN ELEVATION. SURFACE DEW POINTS SHOULD REMAIN AT COMFORTABLE LEVELS IN SPITE OF THIS AS DRIER AIR FROM ALOFT MIXES DOWN. MIXING WON/T BE AS DEEP AS TODAY DUE TO SUBSIDENCE...HOWEVER TEMPERATURES AT THE TOP OF THE MIXED LAYER SHOULD ALLOW FOR HIGHS OF GENERALLY 75-80 ONCE AGAIN. DRY WEATHER CONTINUES INTO THURSDAY NIGHT WITH LOWS STILL BELOW NORMAL...BUT NOT AS COOL AS TONIGHT. && .LONG TERM /FRIDAY THROUGH TUESDAY/... GLOBAL MODELS IN GOOD AGREEMENT WITH THE OVERALL PATTERN IN THE LONG TERM TIME FRAME. ALOFT...A MEAN TROUGH WILL GIVE WAY TO SLIGHTLY RISING HEIGHTS BY SATURDAY AND CONTINUING TO BUILD THROUGH THE WEEK. GFS IS SLIGHTLY MORE AGGRESSIVE WITH THE STRONG RIDGE MOVING IN WHILE THE ECMWF TRACKS A SHORTWAVE THROUGH MONDAY AND THEN QUICKLY RISES THE HEIGHTS. AT THE SURFACE... HIGH PRESSURE REMAINS IN CONTROL THROUGH THE LONG TERM WITH A GENERAL SOUTH-SOUTHWEST FLOW. USED A MAV/MET BLEND FOR TEMPS ON FRIDAY WITH A GOOD GENERAL AGREEMENT FOR NEAR NORMAL VALUES. TEMPS WILL CONTINUE TO MODERATE THROUGH THE WEEK AND USED WPC GUIDANCE AS IT SEEMED REASONABLE WITH NO MAJOR TEMPERATURE FLUXES. NEAR TO JUST ABOVE NORMAL TEMPS ARE EXPECTED. MODELS TRYING TO HINT AT A FEW SHOWERS ON FRIDAY BUT HAVE CONTINUED THE DRY FORECAST WITH LITTLE INSTABILITY OR LIFT. ON SATURDAY...A COLD FRONT WILL WEAKEN AND DISSIPATE BY THE TIME IT REACHES THE WESTERN CWA BOUNDARY. WITH SOME INSTABILITY IN PLACE WITH AFTERNOON HEATING...THIS BOUNDARY COULD CREATE A FEW SHOWERS...MOSTLY IN FAR NORTH AND WEST ZONES. HAVE LEFT CHANCE POPS FOR THAT AREA. HIGHEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE SUNDAY NIGHT INTO MONDAY AS A COLD FRONT APPROACHES AND POSSIBLY REMAINING STATIONARY THROUGH MONDAY. ECMWF ALSO TRYING TO HINT AT A POTENTIAL DECAYING MCS TRACKING SE ALONG THE FRONT...ALONG THE SOUTHERN SIDE OF AN UPPER JET. WILL GENERALLY KEEP CHANCE POPS IN THE AREAS NORTH AND WEST OF NYC AND SLIGHT CHANCE ELSEWHERE. THE NORTHERN AREAS WILL HAVE THE HIGHEST INSTABILITY DURING THE DAY AND THEREFORE THE GREATEST PRECIP CHANCES. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES THROUGH TONIGHT. VFR THROUGH THE TAF PERIOD. MID AND HIGH CLOUDS GRADUALLY CONTINUE TO DISSIPATE THROUGH THE DAY...THEN SKC TONIGHT. N-NNE AROUND 10 KT THROUGH AT LEAST EARLY AFTERNOON WITH ISOLATED GUSTS 15-20 KT...EXCEPT AT KEWR WHICH LIKELY WILL HAVE MORE FREQUENT GUSTS FROM MIDDAY INTO EARLY AFTERNOON. SEA BREEZE LIKELY MID-LATE AFTERNOON/EARLY EVENING KBDR/KGON/KJFK/KISP/KLGA/KEWR. WINDS BECOME LIGHT AND VARIABLE AT ALL TERMINALS THIS EVENING. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: MODERATE-HIGH CONFIDENCE IN SEABREEZE - LOW CONFIDENCE IN EXACT TIMING. COULD BE OFF +/- 2 HOURS. ISOLATED GUSTS TO 15-20 KT POSSIBLE THROUGH EARLY AFTERNOON. HIGH CONFIDENCE IN WINDS TO THE RIGHT OF 300 TRUE THROUGH EARLY AFTERNOON. KLGA FCSTER COMMENTS: MODERATE CONFIDENCE IN SEABREEZE - LOW CONFIDENCE IN EXACT TIMING. COULD BE OFF +/- 2-3 HOURS. ISOLATED GUSTS TO 15-20 KT POSSIBLE THROUGH EARLY AFTERNOON. HIGH CONFIDENCE IN WINDS TO THE RIGHT OF 300 TRUE THROUGH EARLY AFTERNOON. KEWR FCSTER COMMENTS: MODERATE CONFIDENCE IN SEABREEZE - LOW CONFIDENCE IN EXACT TIMING. COULD BE OFF +/- 2-3 HOURS. ISOLATED GUSTS TO 15-20 KT POSSIBLE THROUGH MIDDAY...THEN MODERATE CONFIDENCE IN MORE FREQUENT GUSTS AROUND 16-20Z. HIGH CONFIDENCE IN WINDS TO THE RIGHT OF 300 TRUE THROUGH EARLY AFTERNOON. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: LOW-MODERATE CONFIDENCE IN SEABREEZE - LOW CONFIDENCE IN EXACT TIMING. COULD BE OFF +/- 2-3 HOURS. ISOLATED GUSTS TO 15-20 KT POSSIBLE THROUGH EARLY AFTERNOON. KHPN FCSTER COMMENTS: VERY LOW CHANCE OF SEABREEZE LATE THIS AFTERNOON/EARLY THIS EVENING. ISOLATED GUSTS TO 15-20 KT POSSIBLE THROUGH EARLY AFTERNOON. KISP FCSTER COMMENTS: MODERATE-HIGH CONFIDENCE IN SEABREEZE - LOW CONFIDENCE IN EXACT TIMING. COULD BE OFF +/- 2 HOURS. ISOLATED GUSTS TO 15-20 KT POSSIBLE THROUGH EARLY AFTERNOON. .OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY... .THURSDAY-SATURDAY MORNING...VFR. .SATURDAY AFTERNOON/NIGHT. MAINLY VFR...EXCEPT MVFR OR LOWER POSSIBLE IN ISOLD-SCT SHRA/TSRA MAINLY TO THE N/W OF CITY TERMINALS IN THE AFTERNOON/EVENING. .SUNDAY...MVFR OR LOWER POSSIBLE. && .MARINE... HIGH PRESSURE BUILDS IN OVER THE WATERS THROUGH THE DAY TODAY. A NORTHERLY FLOW AT AROUND 15 KT WEAKENS THIS AFTERNOON WITH LOCAL SEA BREEZE DIRECTIONS DEVELOPING NEARSHORE LATE IN THE DAY. A LIGHT RETURN S TO SW FLOW DEVELOPS FOR THURSDAY AS THE CENTER OF HIGH PRESSURE SHIFTS OFFSHORE. TRANQUIL CONDITIONS THEREFORE PREVAIL. WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH EARLY NEXT WEEK AS HIGH PRESSURE REMAINS OVER THE AREA. && .HYDROLOGY... DRY WEATHER IS EXPECTED THROUGH AT LEAST SUNDAY MORNING. SHOWERS AND THUNDERSTORMS ARE POSSIBLE EACH AFTERNOON SUN-TUE BUT NO WIDESPREAD SIGNIFICANT PRECIPITATION IS EXPECTED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JC/LN NEAR TERM...DS SHORT TERM...JC LONG TERM...LN AVIATION...JMC/MALOIT MARINE...JC/LN/DS HYDROLOGY...JC/LN
AREA FORECAST DISCUSSION
NWS MIAMI FL
809 PM EDT THU JUN 20 2013 .UPDATE... SHOWERS AND THUNDERSTORMS WERE BEGINNING TO DISSIPATE ACROSS THE REGION THIS EVENING. A STALLED FRONTAL BOUNDARY WAS DRAPED ACROSS NORTH FLORIDA...AND SOME MODELS INDICATE THAT SOME SHOWERS OR STORMS MAY FIRE SOUTH OF THAT BOUNDARY ACROSS CENTRAL FLORIDA AND NEAR THE LAKE REGION OVERNIGHT. WATER VAPOR IMAGERY SHOWS A LARGE AREA OF DRY AIR OVER THE BAHAMAS MOVING TO THE WEST AHEAD OF A TROPICAL WAVE. THIS AREA OF DRY AIR IS EXPECTED TO BEGIN MOVING INTO SOUTH FLORIDA LATE TONIGHT THROUGH THE DAY ON FRIDAY. THE OUTFLOW BOUNDARY FROM EARLIER CONVECTION WAS MOVING INTO THE ATLANTIC...AND DEWPOINTS WERE FALLING INTO THE UPPER 60S ALONG THE EAST COAST BEHIND THE OUTFLOW BOUNDARY. SO NOT EXPECTING A REPEAT OF LATE NIGHT SHOWERS AND STORMS ALONG THE EAST COAST. && .PREV DISCUSSION... /ISSUED 751 PM EDT THU JUN 20 2013/ AVIATION... THE EAST COAST TAF SITES WILL SEE A WESTERLY WIND FLOW UNTIL AROUND 02Z DUE TO AN OUTFLOW BOUNDARY PUSHING THROUGH THE EAST COAST TAF SITES EARLY THIS EVENING. THE WIND FLOW SHOULD THEN BECOME LIGHT AND VARIABLE AFTER 02Z TONIGHT...BEFORE INCREASING TO AROUND 10 KNOTS FROM THE EAST DIRECTION ON FRIDAY AFTER 13Z. KAPF TAF SITE WILL ALSO SEE LIGHT AND VARIABLE WINDS TONIGHT INTO FRIDAY MORNING...BEFORE SWINGING TO A WESTERLY DIRECTION FOR FRIDAY AFTERNOON. THE EAST COAST TAF SITES WILL ALSO SEE SOME SHOWERS AROUND FOR THE EARLY PART OF THIS EVENING DUE TO THE OUTFLOW BOUNDARY...BEFORE GOING DRY AFTER 02Z. THE DRY WEATHER SHOULD CONTINUE THROUGH FRIDAY...DUE TO DRIER AIR WORKING INTO THE AREA FROM THE EAST. KAPF TAF SITE WILL ALSO SEE SOME SHOWERS THROUGH O2Z THEN GO DRY THROUGH REST OF THE NIGHT INTO FRIDAY MORNING. SO WILL KEEP VCSH IN ALL OF THE TAF SITES FROM 00Z UNTIL 02Z...THEN NO WEATHER AFTER 02Z TONIGHT INTO FRIDAY MORNING. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS TONIGHT INTO FRIDAY FOR ALL OF THE TAF SITES. AVIATION...54/BNB PREV DISCUSSION... /ISSUED 224 PM EDT THU JUN 20 2013/ SHORT TERM (TONIGHT-SATURDAY NIGHT)... AFTER A BUSY START EARLY THIS MORNING ALONG THE EAST COAST WHERE RAINFALL TOTALS RANGED FROM 1 TO 3 INCHES WITHIN A FEW HOURS BY OR AROUND SUNRISE...MOST OF THE AFTERNOON SHOWER/TSTM ACTIVITY IS NOW INLAND AROUND THE LAKE REGION AND ALONG THE GULF COAST NORTH OF NAPLES. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES GENERALLY INDICATE THIS EARLY AFTERNOON ACTIVITY CONTINUING TO DEVELOP AND BECOMING MORE WIDESPREAD ACROSS THESE INTERIOR AND GULF COAST AREAS THROUGH THE LATE AFTERNOON AND EARLY EVENING PERIODS. VERY WEAK FLOW DEPICTED IN THE MORNING UPPER AIR SOUNDING WILL RESULT IN VERY LITTLE STORM MOTION AND MAY TRANSLATE TO FLOODING IN THE AREAS WHERE THE RAINFALL BECOMES CONCENTRATED. WMSI VALUES FROM THE MORNING SOUNDING AND THE GFS/NAM/WRF ARW...WHICH ARE BASED ON MID/SFC THETA-E DIFFERENCES AND SB-CAPE ARE NOT VERY IMPRESSIVE SPATIALLY ACROSS SOUTH FLORIDA. THEREFORE...THE POTENTIAL FOR STRONG THUNDERSTORMS WITH GUSTS UP TO 50 MPH APPEARS TO BE LOW AT THIS TIME WITH THE MAIN THREAT BEING HEAVY RAIN. TONIGHT THROUGH SATURDAY NIGHT...ELIMINATING THE POTENTIAL FOR ANOTHER ROUND OF HEAVY RAINFALL SETTING UP ALONG THE EAST COAST THROUGH THE LATE NIGHT/EARLY MORNING HOURS RESULTING IN RAIN-COOLED AIR AT THE SURFACE...SIMILAR TO THIS MORNING...OVERNIGHT TEMPERATURES ARE FORECAST TO REMAIN SEVERAL DEGREES ABOVE AVERAGE EACH NIGHT. AS A RESULT...WARMEST MINIMUM TEMPERATURE RECORDS COULD BE BROKEN EACH NIGHT ALONG THE EAST COAST. OTHERWISE...SIMILAR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH FRIDAY WITH LIGHT SOUTHEAST LOW-LEVEL FLOW AND INTERIOR AFTERNOON SHOWERS/TSTMS. FRIDAY NIGHT THROUGH SATURDAY NIGHT...MODELS REMAIN PERSISTENT FROM RUN TO RUN AND CONTINUE TO INDICATE A TROPICAL WAVE APPROACHING AND MOVING INTO THE AREA. MODEL PWS ASSOCIATED WITH THIS WAVE ARE FORECAST TO NEAR THE 2" MARK BY SATURDAY NIGHT...WHICH SHOULD TRANSLATE TO HIGHER RAIN CHANCES ACROSS THE AREA. LONG TERM (SUNDAY-WEDNESDAY)... THE PREVIOUSLY DISCUSSED WAVE WILL CONTINUE WEST OF THE PENINSULA BY LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK WITH SOME DRYING ALOFT ONCE AGAIN SPREADING OVER THE LOCAL AREA. THE MID-LEVEL RIDGE WILL ALSO REBUILD BACK ACROSS THE PENINSULA WITH A BIT LESS OF INSTABILITY ALSO IN PLACE AND POPS WILL DROP BACK A LITTLE BELOW THE AVERAGE FOR LATE JUNE. 30/KOB AVIATION... VFR WILL PREVAIL. MOST OF THE SHOWERS OR STORMS THAT DEVELOP ARE FORECAST TO BE ACROSS THE INTERIOR. THE FORECAST REASONING IS THAT DIURNAL CONVECTION IS EXPECTED FOR TODAY WITH MOST OF THE ACTIVITY EXPECTED TO LAST INTO LATE EVENING FOR THE INTERIOR AND WEST COAST. FOR NOW HAS KEPT VCSH FOR ALL TERMINALS SINCE THERE IS A LAYER OF DRY AIR VISIBLE FROM THE SOUNDING AROUND 700MB. THIS COULD SLOW DOWN THE FORMATION OF CONVECTION. BY THE TIME THAT CONVECTION FORMS IT MAY FOCUS MORE ALONG THE SEA BREEZES WHICH WOULD HAVE ALREADY PUSHED FURTHER INLAND. DRIER CONDITIONS ARE EXPECTED ON FRIDAY DUE TO DRIER AIR MOVING INTO THE AREA FROM THE EAST. MARINE... LIGHT TO MODERATE SOUTHEAST WINDS ASSOCIATED WITH HIGH PRESSURE WILL PERSIST THROUGH THE REMAINDER OF THE WEEK. THE BEST CHANCE FOR ISOLATED SHOWERS AND STORMS WILL BE THROUGH THE OVERNIGHT AND EARLY MORNING HOURS EACH DAY. A WEAK TROPICAL WAVE WILL APPROACH AND MOVE THROUGH THE MARINE AREA OVER THE WEEKEND AND MAY TRANSLATE TO BETTER SHOWER/TSTM COVERAGE. FIRE WEATHER... RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE CRITICAL LEVELS EACH DAY. LIGHT SOUTHEAST WINDS ARE EXPECTED TO PERSIST THROUGH MUCH OF THE WEEK...EXCEPT THROUGH THE AFTERNOON PERIODS AS THE GULF COAST SEA BREEZES PENETRATES INLAND ACROSS PORTIONS OF COLLIER COUNTY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 77 87 78 88 / 20 20 20 50 FORT LAUDERDALE 79 88 80 88 / 20 20 20 50 MIAMI 79 89 79 88 / 20 20 20 50 NAPLES 74 93 73 91 / 20 30 20 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...84/AK AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
751 PM EDT THU JUN 20 2013 .AVIATION... THE EAST COAST TAF SITES WILL SEE A WESTERLY WIND FLOW UNTIL AROUND 02Z DUE TO AN OUTFLOW BOUNDARY PUSHING THROUGH THE EAST COAST TAF SITES EARLY THIS EVENING. THE WIND FLOW SHOULD THEN BECOME LIGHT AND VARIABLE AFTER 02Z TONIGHT...BEFORE INCREASING TO AROUND 10 KNOTS FROM THE EAST DIRECTION ON FRIDAY AFTER 13Z. KAPF TAF SITE WILL ALSO SEE LIGHT AND VARIABLE WINDS TONIGHT INTO FRIDAY MORNING...BEFORE SWINGING TO A WESTERLY DIRECTION FOR FRIDAY AFTERNOON. THE EAST COAST TAF SITES WILL ALSO SEE SOME SHOWERS AROUND FOR THE EARLY PART OF THIS EVENING DUE TO THE OUTFLOW BOUNDARY...BEFORE GOING DRY AFTER 02Z. THE DRY WEATHER SHOULD CONTINUE THROUGH FRIDAY...DUE TO DRIER AIR WORKING INTO THE AREA FROM THE EAST. KAPF TAF SITE WILL ALSO SEE SOME SHOWERS THROUGH O2Z THEN GO DRY THROUGH REST OF THE NIGHT INTO FRIDAY MORNING. SO WILL KEEP VCSH IN ALL OF THE TAF SITES FROM 00Z UNTIL 02Z...THEN NO WEATHER AFTER 02Z TONIGHT INTO FRIDAY MORNING. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS TONIGHT INTO FRIDAY FOR ALL OF THE TAF SITES. && .AVIATION...54/BNB .PREV DISCUSSION... /ISSUED 224 PM EDT THU JUN 20 2013/ SHORT TERM (TONIGHT-SATURDAY NIGHT)... AFTER A BUSY START EARLY THIS MORNING ALONG THE EAST COAST WHERE RAINFALL TOTALS RANGED FROM 1 TO 3 INCHES WITHIN A FEW HOURS BY OR AROUND SUNRISE...MOST OF THE AFTERNOON SHOWER/TSTM ACTIVITY IS NOW INLAND AROUND THE LAKE REGION AND ALONG THE GULF COAST NORTH OF NAPLES. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES GENERALLY INDICATE THIS EARLY AFTERNOON ACTIVITY CONTINUING TO DEVELOP AND BECOMING MORE WIDESPREAD ACROSS THESE INTERIOR AND GULF COAST AREAS THROUGH THE LATE AFTERNOON AND EARLY EVENING PERIODS. VERY WEAK FLOW DEPICTED IN THE MORNING UPPER AIR SOUNDING WILL RESULT IN VERY LITTLE STORM MOTION AND MAY TRANSLATE TO FLOODING IN THE AREAS WHERE THE RAINFALL BECOMES CONCENTRATED. WMSI VALUES FROM THE MORNING SOUNDING AND THE GFS/NAM/WRF ARW...WHICH ARE BASED ON MID/SFC THETA-E DIFFERENCES AND SB-CAPE ARE NOT VERY IMPRESSIVE SPATIALLY ACROSS SOUTH FLORIDA. THEREFORE...THE POTENTIAL FOR STRONG THUNDERSTORMS WITH GUSTS UP TO 50 MPH APPEARS TO BE LOW AT THIS TIME WITH THE MAIN THREAT BEING HEAVY RAIN. TONIGHT THROUGH SATURDAY NIGHT...ELIMINATING THE POTENTIAL FOR ANOTHER ROUND OF HEAVY RAINFALL SETTING UP ALONG THE EAST COAST THROUGH THE LATE NIGHT/EARLY MORNING HOURS RESULTING IN RAIN-COOLED AIR AT THE SURFACE...SIMILAR TO THIS MORNING...OVERNIGHT TEMPERATURES ARE FORECAST TO REMAIN SEVERAL DEGREES ABOVE AVERAGE EACH NIGHT. AS A RESULT...WARMEST MINIMUM TEMPERATURE RECORDS COULD BE BROKEN EACH NIGHT ALONG THE EAST COAST. OTHERWISE...SIMILAR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH FRIDAY WITH LIGHT SOUTHEAST LOW-LEVEL FLOW AND INTERIOR AFTERNOON SHOWERS/TSTMS. FRIDAY NIGHT THROUGH SATURDAY NIGHT...MODELS REMAIN PERSISTENT FROM RUN TO RUN AND CONTINUE TO INDICATE A TROPICAL WAVE APPROACHING AND MOVING INTO THE AREA. MODEL PWS ASSOCIATED WITH THIS WAVE ARE FORECAST TO NEAR THE 2" MARK BY SATURDAY NIGHT...WHICH SHOULD TRANSLATE TO HIGHER RAIN CHANCES ACROSS THE AREA. LONG TERM (SUNDAY-WEDNESDAY)... THE PREVIOUSLY DISCUSSED WAVE WILL CONTINUE WEST OF THE PENINSULA BY LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK WITH SOME DRYING ALOFT ONCE AGAIN SPREADING OVER THE LOCAL AREA. THE MID-LEVEL RIDGE WILL ALSO REBUILD BACK ACROSS THE PENINSULA WITH A BIT LESS OF INSTABILITY ALSO IN PLACE AND POPS WILL DROP BACK A LITTLE BELOW THE AVERAGE FOR LATE JUNE. 30/KOB AVIATION... VFR WILL PREVAIL. MOST OF THE SHOWERS OR STORMS THAT DEVELOP ARE FORECAST TO BE ACROSS THE INTERIOR. THE FORECAST REASONING IS THAT DIURNAL CONVECTION IS EXPECTED FOR TODAY WITH MOST OF THE ACTIVITY EXPECTED TO LAST INTO LATE EVENING FOR THE INTERIOR AND WEST COAST. FOR NOW HAS KEPT VCSH FOR ALL TERMINALS SINCE THERE IS A LAYER OF DRY AIR VISIBLE FROM THE SOUNDING AROUND 700MB. THIS COULD SLOW DOWN THE FORMATION OF CONVECTION. BY THE TIME THAT CONVECTION FORMS IT MAY FOCUS MORE ALONG THE SEA BREEZES WHICH WOULD HAVE ALREADY PUSHED FURTHER INLAND. DRIER CONDITIONS ARE EXPECTED ON FRIDAY DUE TO DRIER AIR MOVING INTO THE AREA FROM THE EAST. MARINE... LIGHT TO MODERATE SOUTHEAST WINDS ASSOCIATED WITH HIGH PRESSURE WILL PERSIST THROUGH THE REMAINDER OF THE WEEK. THE BEST CHANCE FOR ISOLATED SHOWERS AND STORMS WILL BE THROUGH THE OVERNIGHT AND EARLY MORNING HOURS EACH DAY. A WEAK TROPICAL WAVE WILL APPROACH AND MOVE THROUGH THE MARINE AREA OVER THE WEEKEND AND MAY TRANSLATE TO BETTER SHOWER/TSTM COVERAGE. FIRE WEATHER... RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE CRITICAL LEVELS EACH DAY. LIGHT SOUTHEAST WINDS ARE EXPECTED TO PERSIST THROUGH MUCH OF THE WEEK...EXCEPT THROUGH THE AFTERNOON PERIODS AS THE GULF COAST SEA BREEZES PENETRATES INLAND ACROSS PORTIONS OF COLLIER COUNTY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 77 87 78 88 / 20 20 20 50 FORT LAUDERDALE 79 88 80 88 / 20 20 20 50 MIAMI 79 89 79 88 / 20 20 20 50 NAPLES 74 93 73 91 / 20 30 20 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...71/JE
AREA FORECAST DISCUSSION
NWS MIAMI FL
231 PM EDT WED JUN 19 2013 .SHORT TERM (TONIGHT-FRIDAY NIGHT)... EARLY AFTERNOON SHOWERS AND THUNDERSTORMS HAVE ALREADY BEGUN TO INITIATE ACROSS PORTIONS OF THE LOCAL AREA AS THE EAST AND WEST COAST SEA BREEZES BEGIN TO PENETRATE INLAND. SOME OF THIS ACTIVITY APPEARS TO HAVE BEEN ENHANCED BY A MID-LEVEL VORT PROGRESSING EASTWARD FROM LAKE OKEECHOBEE EARLIER...WHICH SHOWED UP WELL ON THE VISIBLE SATELLITE LOOP. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES APPEAR TO BE INITIALIZING WELL WITH THE LATEST RADAR TRENDS AND GENERALLY INDICATE THIS EARLY AFTERNOON ACTIVITY CONTINUING TO DEVELOP AND BECOMING CONCENTRATED ACROSS THE INTERIOR AND WRN LOCATIONS THROUGH THE LATE AFTERNOON AND EARLY EVENING PERIODS AS THE SEA BREEZES BOUNDARIES PENETRATE FARTHER INLAND AND MERGE. ALTHOUGH MID-LEVEL LAPSE RATES AND H5 TEMPERATURES ARE NOT VERY IMPRESSIVE TODAY...A FEW STORMS MAY BECOME STRONG WITH THE MAIN THREAT BEING GUSTY WINDS UP TO 45 MPH. TONIGHT THROUGH FRIDAY NIGHT...THE GENERAL TREND WITH ABOVE AVERAGE TEMPERATURES WILL PERSIST...ESPECIALLY THROUGH THE OVERNIGHT HOURS WHEN TEMPERATURES ARE FORECAST TO REMAIN SEVERAL DEGREES ABOVE AVERAGE. AS A RESULT...WARMER MINIMUM TEMPERATURE RECORDS COULD BE BROKEN EACH NIGHT. MODEL PRECIPITABLE WATER VALUES INDICATE A SLIGHT DRYING TREND THURSDAY THROUGH FRIDAY AHEAD OF AN APPROACHING TROPICAL WAVE WITH VALUES TRENDING DOWN TO AROUND 1.5". HOWEVER...DAYTIME HEATING COMBINED WITH SE LOW-LEVEL FLOW UP TO H7 AROUND THE SUBTROPICAL RIDGE AXIS WILL BE ENOUGH TO SUPPORT ANOTHER ROUND OF ISLTD/SCT AFTERNOON SHOWERS/TSTMS...ESPECIALLY ACROSS THE INTERIOR LOCATIONS THROUGH THE LATE AFTERNOON AND EARLY EVENING PERIODS. HAZY CONDITIONS DUE TO HIGHER CONCENTRATIONS OF DUST SPREADING INTO THE AREA FROM THE SE WILL REMAIN POSSIBLE EACH DAY. .LONG TERM (SATURDAY-TUESDAY)... MODELS REMAIN PERSISTENT FROM RUN TO RUN AND CONTINUE TO INDICATE A TROPICAL WAVE APPROACHING AND MOVING THROUGH THE AREA OVER THE WEEKEND. MODEL PWS ASSOCIATED WITH THIS WAVE ARE FORECAST TO NEAR THE 2" MARK BY SUNDAY...WHICH SHOULD TRANSLATE TO HIGHER RAIN CHANCES. CONDITIONS SHOULD TREND BACK TO NORMAL THROUGH THE EARLY HALF OF THE UPCOMING WEEK AS THE WAVE TRACKS WEST AND AWAY FROM THE LOCAL AREA. && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD. WINDS WILL REMAIN OUT OF THE EAST SOUTHEAST BETWEEN 10 TO 15 KNOTS THIS AFTERNOON AND THIS EVENING ACROSS THE EAST COAST TERMINALS. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON MAINLY WEST OF THE EAST COAST TERMINALS. AT KAPF, A WEST COAST SEA BREEZE WILL DEVELOP LATER THIS AFTERNOON. WINDS WILL DIMINISH ACROSS ALL TERMINALS THIS EVENING AND THEN THEY WILL INCREASE AGAIN BY THE MIDDLE OF THURSDAY MORNING. && .MARINE... LIGHT TO MODERATE SOUTHEAST WINDS ASSOCIATED WITH HIGH PRESSURE WILL PERSIST THROUGH THE WEEK. THE BEST CHANCE FOR ISOLATED SHOWERS AND STORMS WILL BE THROUGH THE OVERNIGHT AND EARLY MORNING HOURS EACH DAY. A WEAK TROPICAL WAVE WILL APPROACH AND MOVE THROUGH THE MARINE AREA OVER THE WEEKEND AND MAY TRANSLATE TO BETTER SHOWER/TSTM COVERAGE. && .FIRE WEATHER... RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE CRITICAL LEVELS EACH DAY. LIGHT SOUTHEAST WINDS ARE EXPECTED TO PERSIST THROUGH MUCH OF THE WEEK...EXCEPT THROUGH THE AFTERNOON PERIODS AS THE GULF COAST SEA BREEZES PENETRATES INLAND ACROSS PORTIONS OF COLLIER COUNTY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 77 87 78 88 / 20 20 20 20 FORT LAUDERDALE 80 89 81 89 / 20 20 20 20 MIAMI 78 89 80 89 / 20 20 20 20 NAPLES 75 92 74 93 / 20 30 20 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...55/CWC
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
630 AM EDT WED JUN 19 2013 .SYNOPSIS... THE THREAT OF SHOWERS AND THUNDERSTORMS WILL REMAIN ACROSS THE MIDLANDS AND CSRA TODAY AS A COLD FRONT SLOWLY SINKS SOUTHWARD ACROSS THE AREA. MOISTURE WILL DIMINISH FROM THE NORTH TONIGHT INTO THURSDAY AS HIGH PRESSURE BUILDS IN FROM THE NORTH. THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL RETURN FOR THE WEEKEND AS INCREASINGLY WARM AND HUMID CONDITIONS RETURN. && .NEAR TERM /THROUGH TONIGHT/... THROUGH 9 AM...SURFACE COLD FRONT EXTENDING FROM BISHOPVILLE THROUGH NEWBERRY TO LINCOLNTON AT 10Z. SCATTERED SHOWERS ALONG AND SOUTH OF THE BOUNDARY. INSTABILITY WEAK AND FORCING LIMITED WITH PRECIPITABLE WATER RANGING FROM 1.50 TO 2.00 INCHES. AFTER 9 AM...THE SURFACE COLD FRONT SHOULD SLOWLY MOVE SOUTHWARD ACROSS THE AREA TODAY. THE LATEST RUC AND NAM MODELS INDICATE A WEAK SHORT WAVE CROSSING THE AREA TODAY. HAVE INCREASED POPS ACROSS THE SOUTHEAST TO LIKELY...KEPT CHANCE POPS FOR TODAY FOR THE THE REMAINDER OF THE AREA. THREAT FOR CONVECTION WILL GRADUALLY DIMINISH FROM THE NORTH TO SOUTH THROUGH THIS EVENING AS DRIER AND MORE STABLE AIR FILTERS IN. WENT NEAR CONSENSUS WITH HIGHS IN THE MID 80S AND LOWS IN THE MID TO UPPER 60S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... MAINLY DRY WEATHER EXPECTED THURSDAY INTO FRIDAY NIGHT AS HIGH PRESSURE RIDGES IN FROM THE NORTH. HIGHEST PRECIPITABLE WATER WILL BE SOUTH OF THE CSRA. CONSENSUS MOS TEMPS LOOK REASONABLE WITH HIGHS IN THE 85 TO 90 DEGREE RANGE AND LOWS IN THE 60S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH A WEAK UPPER LEVEL LOW AFFECTING THE SOUTHEASTERN STATES. THE FLOW AROUND SURFACE HIGH PRESSURE LOCATED OFF THE ATLANTIC COAST WILL BRING INCREASING MOISTURE TO THE REGION. AS A RESULT WE CAN EXPECT A CHANCE OF MAINLY DIURNAL CONVECTIVE ACTIVITY...ALONG WITH SEASONABLY WARM TEMPERATURES. && .AVIATION /10Z WEDNESDAY THROUGH MONDAY/... A MIXTURE OF VFR AND IFR CONDITIONS AT THE TAF SITES THIS MORNING. MAINLY DUE TO LOW CEILINGS AND SOME LIGHT FOG. 88D CONTINUES TO SHOW ...MAINLY SHOWERS MOVING NORTHEAST ACROSS THE AREA THIS MORNING. THE ACTIVITY IS ALONG/SOUTH OF A COLD FRONT THAT IS TRYING TO MOVE SLOWLY SOUTHEAST OVER THE AREA. EXPECT CONDITIONS TO RETURN TO VFR AT ALL TAF SITES BETWEEN 12Z-14Z. AS LONG AS FRONTAL BOUNDARY IS ACROSS THE CWA...THERE WILL BE A CHANCE OF SHOWERS/THUNDERSTORMS THROUGH THE DAY. HAVE NOT INCLUDED ANY MENTION OF PRECIPITATION AT THIS TIME AS LACK OF CONFIDENCE OF PLACEMENT/TIMING OF SCATTERED SHOWERS. BY TONIGHT...MODEL TIME SECTIONS SHOW SOME LOW LEVEL MOISTURE WITH THE 06Z NAM MORE MOIST THAN THE 00Z GFS. EXPECT VFR CONDITIONS THROUGH 06Z...BUT SOME MVFR CONDITIONS MAY BE POSSIBLE BEYOND THE TAF PERIOD. EXTENDED AVIATION OUTLOOK...POSSIBLE MVFR CONDITIONS THURSDAY MORNING. A SLIGHT CHANCE OF MAINLY AFTERNOON/EVENING THUNDERSTORMS THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
622 AM EDT WED JUN 19 2013 .SYNOPSIS... THE THREAT OF SHOWERS AND THUNDERSTORMS WILL REMAIN ACROSS THE MIDLANDS AND CSRA TODAY AS A COLD FRONT SLOWLY SINKS SOUTHWARD ACROSS THE AREA. MOISTURE WILL DIMINISH FROM THE NORTH TONIGHT INTO THURSDAY AS HIGH PRESSURE BUILDS IN FROM THE NORTH. THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL RETURN FOR THE WEEKEND AS INCREASINGLY WARM AND HUMID CONDITIONS RETURN. && .NEAR TERM /THROUGH TONIGHT/... THROUGH 9 AM...SURFACE COLD FRONT EXTENDING FROM BISHOPVILLE THROUGH NEWBERRY TO LINCOLNTON AT 10Z. SCATTERED SHOWERS ALONG AND SOUTH OF THE BOUNDARY. INSTABILITY WEAK AND FORCING LIMITED WITH PRECIPITABLE WATER RANGING FROM 1.50 TO 2.00 INCHES. AFTER 9 AM...THE SURFACE COLD FRONT SHOULD SLOWLY MOVE SOUTHWARD ACROSS THE AREA TODAY. THE LATEST RUC AND NAM MODELS INDICATE A WEAK SHORT WAVE CROSSING THE AREA TODAY. HAVE INCREASED POPS ACROSS THE SOUTHEAST TO LIKELY...KEPT CHANCE POPS FOR TODAY FOR THE THE REMAINDER OF THE AREA. THREAT FOR CONVECTION WILL GRADUALLY DIMINISH FROM THE NORTH TO SOUTH THROUGH THIS EVENING AS DRIER AND MORE STABLE AIR FILTERS IN. WENT NEAR CONSENSUS WITH HIGHS IN THE MID 80S AND LOWS IN THE MID TO UPPER 60S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... MAINLY DRY WEATHER EXPECTED THURSDAY INTO FRIDAY NIGHT AS HIGH PRESSURE RIDGES IN FROM THE NORTH. HIGHEST PRECIPITABLE WATER WILL BE SOUTH OF THE CSRA. CONSENSUS MOS TEMPS LOOK REASONABLE WITH HIGHS IN THE 85 TO 90 DEGREE RANGE AND LOWS IN THE 60S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH A WEAK UPPER LEVEL LOW AFFECTING THE SOUTHEASTERN STATES. THE FLOW AROUND SURFACE HIGH PRESSURE LOCATED OFF THE ATLANTIC COAST WILL BRING INCREASING MOISTURE TO THE REGION. AS A RESULT WE CAN EXPECT A CHANCE OF MAINLY DIURNAL CONVECTIVE ACTIVITY...ALONG WITH SEASONABLY WARM TEMPERATURES. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... VFR AT THE TERMINALS CURRENTLY. RADAR INDICATES A FEW SHOWERS/THUNDERSTORMS WELL TO THE NORTH OF THE TERMINALS. ONCE CONVECTION ASSOCIATED WITH A FRONTAL BOUNDARY DISSIPATES LATER TONIGHT...FOCUS WILL SHIFT TO ANY FOG/STRATUS THREAT FOR LATE TONIGHT/EARLY WED. LATEST GUIDANCE GENERALLY POINTING TO POSSIBILITIES OF MVFR CONDITIONS. AFTER ANY MORNING RESTRICTIONS...EXPECT VFR WEDNESDAY. SOME DRIER AIR WILL ENTER OUR FORECAST AREA BEHIND THE FRONT...WITH CHANCES OF CONVECTION WEDNESDAY MAINLY TO OUR SOUTH. CHANCES TOO LOW TO INCLUDE MENTION IN TAFS AT THIS TIME. EXTENDED AVIATION OUTLOOK...SLIGHT CHANCE OF MAINLY AFTERNOON/EVENING THUNDERSTORMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 77
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1012 AM EDT WED JUN 19 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 402 AM EDT WED JUN 19 2013 HIGH PRESSURE WILL BUILD OVER CENTRAL INDIANA BRINGING DRY WEATHER THROUGH THE END OF THE WORK WEEK. AFTER A BRIEF DIP IN TEMPERATURES TODAY HIGHS WILL WARM BACK TO THE UPPER 80S TO LOW 90S FROM FRIDAY ON. SMALL CHANCES FOR THUNDERSTORMS WILL PERSIST FROM SATURDAY THROUGH TUESDAY AS WEAK WAVES MOVE THROUGH THE UPPER FLOW. && .NEAR TERM /REST OF TODAY/... ISSUED AT 930 AM EDT WED JUN 19 2013 FORECAST IS ON TRACK. ONLY SOME PATCHY MID CLOUD ACROSS THE AREA NOW...AND SCATTERED CU STILL LOOK LIKELY TO DEVELOP THIS AFTERNOON. STILL PLENTY OF SUNSHINE THOUGH. ONLY MADE MINOR TWEAKS TO HOURLY FORECASTS. RELEVANT PORTION OF PREVIOUS DISCUSSION FOLLOWS... HIGH PRESSURE WILL BUILD OVER THE AREA TODAY WITH WEAK COLD ADVECTION AT 850 MB AND LIGHT EASTERLY WINDS USHERING IN DRIER AIR. WITH 850 MB TEMPERATURES FALLING TO 11-12C ACROSS THE AREA WENT A DEGREE OR TWO COOLER THAN MAV NUMBERS. DAY WILL START OUT CLEAR BUT TIME HEIGHTS INDICATE SOME LEFTOVER MOISTURE AROUND 850 MB SO COULD SEE SOME SCATTERED CU IN THE AFTERNOON. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... ISSUED AT 402 AM EDT WED JUN 19 2013 FORECAST FOCUS IS ON TEMPERATURES. MODELS WERE GENERALLY IN GOOD AGREEMENT SO USED A CONSENSUS APPROACH. UPPER RIDGING BUILDS ACROSS THE AREA THROUGH THE SHORT TERM. FOR TONIGHT PREFERRED COOLER GUIDANCE NUMBERS UNDER A MOSTLY CLEAR SKY. AS THE SURFACE HIGH SHIFTS EAST SHOULD SEE WARM ADVECTION RAMP UP AND EXPECT SIGNIFICANT WARMING TREND WITH INCREASING HUMIDITY THURSDAY INTO FRIDAY. USED A GUIDANCE CONSENSUS FOR THURSDAY BUT WENT WITH WARMER GUIDANCE ON FRIDAY. WHILE THERE ARE SOME INDICATIONS THAT A BREAKDOWN IN THE RIDGE COULD TAKE PLACE AS EARLY AS FRIDAY GENERAL CONSENSUS IS THAT BREAKDOWN WILL OCCUR OVER THE NORTHERN GREAT LAKES AND THUS KEEP CENTRAL INDIANA DRY. && .LONG TERM /SATURDAY THROUGH TUESDAY/... ISSUED AT 402 AM EDT WED JUN 19 2013 AN UPPER RIDGE WILL DOMINATE OUR WEATHER MUCH OF THE PERIOD. THE GFS SUPPRESSES IT A LITTLE SOUTHWARD TOWARDS DAY 6 AND 7. WHILE THE GEM AND OLD EURO DID NOT. THERE ARE A COUPLE OF SHORT WAVES THAT WILL BE COMING OVER THE TOP OF THE RIDGE THAT MAY PRODUCE LOW CHANCES OF THUNDERSTORMS. THE 12Z EURO INDICATED A PRETTY GOOD CHANCE OF THUNDERSTORMS ACROSS OUR NORTH SATURDAY WITH LESSER CHANCES TOWARDS END OF THE EXTENDED. THE GFS INDICATED VERY LOW CHANCES OF PRECIP ACROSS OUR NORTH OVER THE WEEKEND WITH BETTER CHANCES ALL AREAS TOWARDS DAY 7. 700 MB TEMPERATURES ARE MOSTLY 8 TO 10 CELSIUS RANGE WOULD ALLOW A FEW THUNDERSTORMS. FOR NOW WILL LEAVE 20 PERCENT CHANCE POPS MOST PERIODS...BUT MAINLY OVER NORTHERN SECTIONS OVER THE WEEKEND. WENT CLOSE TO A MOS BLEND ON TEMPERATURES. SOME CASES THE ALL BLEND MAX TEMPERATURES SEEM TO BE A BIT TOO COOL AND LEANED CLOSER TO MEX VALUES. && .AVIATION /DISCUSSION FOR THE 191500Z TAF UPDATE/... ISSUED AT 1012 AM EDT WED JUN 19 2013 FORECAST IN GOOD SHAPE THIS MORNING AS HIGH PRESSURE EXPANDS SOUTH INTO THE REGION. EXPECT SOME CU DEVELOPMENT THROUGH THE AFTERNOON... ESPECIALLY AT KBMG AND KHUF WHERE LOW LEVEL MOISTURE IS A BIT MORE PREVALENT AND CURRENT RAP ANALYSIS INDICATING PRESENCE OF A SUBTLE 850MB THERMAL TROUGH. 12Z DISCUSSION FOLLOWS. VFR THROUGH THE FORECAST PERIOD. HIGH PRESSURE MOVING EAST ACROSS THE GREAT LAKES WILL PRODUCE A LIGHT EAST TO NORTHEAST FLOW WITH DRIER AIR SPREADING INTO THE REGION. CU RULE INDICATES A LITTLE CU. EXPECT ONLY FEW CU AT KIND AND KLAF AND SCT CU ELSEWHERE LATE THIS MORNING AND AFTERNOON. MODEL SOUNDINGS INDICATE MOSTLY CLEAR CONDITIONS TONIGHT WITH SOME HIGH CLOUDS LATE TONIGHT. WINDS WILL BE EAST UP TO 8 KNOTS TODAY BECOMING LIGHT TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...CP NEAR TERM...CP/50 SHORT TERM...CP LONG TERM....JH AVIATION...JH/RYAN VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
414 PM CDT WED JUN 19 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 413 PM CDT WED JUN 19 2013 MAIN FORECAST CONCERN IS WITH SMALL CHANCES OF ISOLATED STORMS ACROSS THE WEST AND NORTH THIS AFTERNOON THROUGH THURSDAY MORNING. LEANED TOWARD A BLEND OF THE HI-RES MODELS FOR TRENDS TONIGHT INTO THURSDAY MORNING. THE ARW-WEST AND LATEST HRRR HAVE SOME ISOLATED THUNDERSTORMS DEVELOPING THIS AFTERNOON INTO THE EARLY EVENING ACROSS WESTERN TO NORTHERN PORTIONS OF THE FORECAST AREA. CAP SEEMS TO BE WINNING ATTM AND CUT BACK ON POPS TO MAINLY THE FAR WEST EVEN THOUGH SURFACE BASED CAPE AROUND 1000-1500 J/KG WITH MUCAPE SLIGHTLY HIGHER. THERE IS VERY LITTLE...IF ANY SHEAR PRESENT THROUGH THE EVENING HOURS..SO NOT ANTICIPATING ANYTHING LONG-LIVED. WEAK THETA-E ADVECTION MOVES INTO WESTERN IOWA PAST 06Z AS A BROAD AREA OF VORTICITY CUTS THROUGH THE REGION TONIGHT. TRANSITIONED CHANCE POPS FURTHER EAST OVERNIGHT AND MAINLY KEPT HIGHEST POPS ACROSS NORTHERN IOWA PAST 06Z THURSDAY WHERE BEST FORCING IS PRESENT. .LONG TERM.../THURSDAY THROUGH WEDNESDAY/... ISSUED AT 413 PM CDT WED JUN 19 2013 UPPER LEVEL LOW CONTINUES SLOWLY MOVE OVER THE PACIFIC NORTHWEST TODAY AND WILL MOVE LITTLE THROUGH SATURDAY BEFORE BEGINNING TO LIFT NORTHEAST INTO CANADA ON SUNDAY. WEAK RIDGING OVER IOWA WILL SLOWLY SHIFT EAST DURING THIS TIME AS WELL AND WILL FOCUS SOUTHWEST FLOW INTO THE UPPER MIDWEST. NUMEROUS SHORT WAVES ARE STILL EXPECTED TO RIPPLE THROUGH THIS FLOW AND IMPACT MAINLY NORTHERN IOWA AND AREAS TO THE NORTH DURING THE PERIOD WHILE WARM AIR ALOFT DRIVES A CAP INTO CENTRAL AND SOUTHERN IOWA FRIDAY INTO SATURDAY. SURFACE LOW PRESSURE WILL LIFT NORTH THROUGH KANSAS AND NEBRASKA THURSDAY AND THURSDAY NIGHT WITH A SECONDARY WARM FRONT MOVING NORTH THROUGH THE STATE. WHILE THE PRIMARY FRONTAL BOUNDARY WILL BE NORTH INTO MINNESOTA DURING THE AFTERNOON...THE POTENTIAL FOR THE SECONDARY BOUNDARY TO LIFT INTO WEST CENTRAL DURING THE AFTERNOON. SOME MIXED LAYER CIN WILL BE IN PLACE THROUGH A WEAK SHORT WAVE IS EXPECTED TO MOVE ACROSS THE AREA WITH MID LEVEL COOLING THAT MAY BE ENOUGH TO KICK OFF A FEW STORMS. IF STORMS FIRE...CERTAINLY A FEW SUPERCELLS WOULD BE POSSIBLE. STILL SOME HINTS THAT A DAKOTAS MCS COULD DROP INTO NORTHERN IOWA THURSDAY NIGHT AND COULD BRING AN ADDITIONAL CHANCE FOR SEVERE WEATHER. MUCH OF THE AREA OVER THE CENTRAL AND SOUTH BECOMES CAPPED FRIDAY INTO THE WEEKEND AND HAVE BEGUN TO DROP POPS ACROSS THESE AREAS WITH THE PRIMARY FOCUS BEING ACROSS THE NORTH. A VERY WARM AND HUMID AIR MASS WILL LIFT INTO THE AREA WITH HIGH TEMPERATURES IN HIGHS IN THE UPPER 80S TO MID 90S AND DEWPOINTS RISING INTO THE 70S. THE SUBTROPICAL HIGH CONTINUES TO EXERT ITSELF OVER THE SOUTHERN PLAINS INTO EARLY NEXT WEEK AND BUILDING NORTH. THE RING OF FIRE MAY CLIP INTO NORTHERN IOWA DURING END OF THE PERIOD BY THE PRIMARY FOCUS WILL BE TO THE NORTH WITH SUMMER IN PLACE OVER IOWA. && .AVIATION...19/18Z ISSUED AT 1239 PM CDT WED JUN 19 2013 VFR CONDITIONS LOOK TO PREVAIL THROUGHOUT THE FORECAST PERIOD. WEAK THETA-E ADVECTION DEVELOPS ACROSS WESTERN IOWA OVERNIGHT TONIGHT AND MAY SPAWN SOME ISOLATED CONVECTION. LEFT MENTION OF ANY THUNDER OUT OF THE TAFS ATTM AS LOW CONFIDENCE IN COVERAGE. OTHERWISE...WINDS WILL INCREASE LATE THURSDAY MORNING AND INTRODUCED GUSTS INTO THE 20-25 KNOT RANGE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...DONAVON AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1244 PM CDT WED JUN 19 2013 ...UPDATED AVIATION DISCUSSION... .SHORT TERM.../TODAY/... ISSUED AT 339 AM CDT WED JUN 19 2013 HIGH PRESSURE RIDGE MOVING OFF TO THE EAST NOW WITH WAA BEGINNING TO MOVE INTO WRN IA. SAT PIX SHOW AN INCREASE IN CLODS FROM DECAYING BLOWOFF CLOUDS. DEEPER MOISTURE CONVERGENCE MOVING INTO SWRN IA WILL BRING AT LEAST ISOLATED TSRA THIS MORNING AS WAA ARC LIFTS NORTHEAST ACROSS THE CWA. KEPT THE PRECIP TO THE WEST HALF HOWEVER. COMBINATION OF NAMDNG5 AND HRRR GIVES A REASONABLE PRESENTATION OF EXPECTED OUTCOME. TEMPS TODAY VERY DEPENDENT ON CLOUD COVER. FEEL THERE WILL BE ENOUGH BREAKS TO GET HIGHS A LITTLE ABOVE MOS GUID AND WARMER THAN YESTERDAY IN MOST LOCATIONS. .LONG TERM.../TONIGHT THROUGH TUESDAY/... ISSUED AT 339 AM CDT WED JUN 19 2013 COMPLICATED FORECAST FOR EXTENDED...WITH MANY PERIODS OF POPS...AND SOMEWHAT LOW CONFIDENCE IN TIMING...WITH BREAKS IN PRECIP CHANCES FROM TIME TO TIME THROUGH THE REMAINDER OF THE WEEK. LARGE UPPER LEVEL LOW WILL BE DRIVER FOR PRECIPITATION CHANCES TROUGH MUCH OF THE PERIOD. LOW WILL REMAIN PRIMARILY OVER PAC NW...AND IS BEGINNING TO SLOWLY PUSH INLAND ATTM. MODELS HAVE SIGNIFICANT DISCREPANCIES OVER PLACEMENT OF LOW...BUT SHOULD COME INTO BETTER AGREEMENT AS LOW PUSHES INLAND. RIDGE REMAINS OVER IOWA THROUGH MUCH OF PERIOD...WITH SHORTWAVES PUSHING THROUGH SPARKING CONVECTION CHANCES. MODELS HAVE SIGNIFICANTLY SLOWED DOWN SHORT WAVES PROPAGATION EASTWARD...WITH FOCUS FOR DEVELOPMENT IN CENTRAL NE PUSHING INTO IOWA LATE OVERNIGHT. HAVE THEREFORE SLOWED POPS FOR OVERNIGHT...THOUGH COULD SEE SOME DEVELOPMENT AHEAD OF MAIN PRECIP BAND WITH THETA-E ADVECTION. SYSTEM IS SLOW MOVING...WITH PRECIP THROUGH THURSDAY. STRONG SHORTWAVE SET TO TRACK ACROSS NORTHERN PLAINS LATE THURSDAY. THIS WILL LIKELY BE THE FOCUS FOR SEVERE WEATHER ACROSS THE DAKOTAS...AND MAY FORM INTO MCS PUSHING ACROSS IOWA...WITH NORTHERN IOWA MOST LIKELY LOCATION OVERNIGHT THURSDAY. SEVERE WEATHER WILL BE POSSIBLE WITH THIS SYSTEM. SHORTWAVE EXPECTED TO TRACK ACROSS SOUTHERN SD/MN AND HEAVIEST PRECIP MAY STAY NORTH. NUMEROUS SHORTWAVES CONTINUE TO TRACK EAST AS UPPER LEVEL LOW REMAINS ACROSS NORTHWESTERN US. AS LOW PUSHES EASTWARD...TRACKS OF WAVES WILL LIKELY GO NORTH OF CWA...BUT MAY SEE DEVELOPMENT FURTHER SOUTH...AND HAVE KEPT POPS ACROSS THE NORTH. SOMEWHAT STRONGER WAVE PUSHES THROUGH FLOW FOR THE WEEKEND...THOUGH UPPER LEVEL LOW WILL PUSH EASTWARD AND SURFACE LOW IN WESTERN PLAINS WILL ALSO LIFT NE AT THIS TIME...AND TIMING AND LOCATION FOR PRECIPITATION CHANCES OVER THE WEEKEND IS VERY MUDDLED. AS UPPER LEVEL LOW PUSHES EAST FRONT WILL DROP ACROSS IOWA WITH PROLONGED PRECIPITATION CHANCE FOR LATE IN THE PERIOD. TEMPERATURES WILL WARM SIGNIFICANTLY UNDER THE RIDGE...WITH SURFACE SOUTHERLY FLOW. HAVE BUMPED TEMPERATURES UP WITH WAA FOR EARLY IN THE PERIOD...THOUGH MIXING MAY BE SOMEWHAT LIMITED. OVERALL...TEMPERATURES WILL WARM WITH SUMMER LIKE READINGS. && .AVIATION...19/18Z ISSUED AT 1239 PM CDT WED JUN 19 2013 VFR CONDITIONS LOOK TO PREVAIL THROUGHOUT THE FORECAST PERIOD. WEAK THETA-E ADVECTION DEVELOPS ACROSS WESTERN IOWA OVERNIGHT TONIGHT AND MAY SPAWN SOME ISOLATED CONVECTION. LEFT MENTION OF ANY THUNDER OUT OF THE TAFS ATTM AS LOW CONFIDENCE IN COVERAGE. OTHERWISE...WINDS WILL INCREASE LATE THURSDAY MORNING AND INTRODUCED GUSTS INTO THE 20-25 KNOT RANGE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MS JUN 13 LONG TERM...AWB AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
638 AM CDT WED JUN 19 2013 .SHORT TERM.../TODAY/... ISSUED AT 339 AM CDT WED JUN 19 2013 HIGH PRESSURE RIDGE MOVING OFF TO THE EAST NOW WITH WAA BEGINNING TO MOVE INTO WRN IA. SAT PIX SHOW AN INCREASE IN CLODS FROM DECAYING BLOWOFF CLOUDS. DEEPER MOISTURE CONVERGENCE MOVING INTO SWRN IA WILL BRING AT LEAST ISOLATED TSRA THIS MORNING AS WAA ARC LIFTS NORTHEAST ACROSS THE CWA. KEPT THE PRECIP TO THE WEST HALF HOWEVER. COMBINATION OF NAMDNG5 AND HRRR GIVES A REASONABLE PRESENTATION OF EXPECTED OUTCOME. TEMPS TODAY VERY DEPENDENT ON CLOUD COVER. FEEL THERE WILL BE ENOUGH BREAKS TO GET HIGHS A LITTLE ABOVE MOS GUID AND WARMER THAN YESTERDAY IN MOST LOCATIONS. .LONG TERM.../TONIGHT THROUGH TUESDAY/... ISSUED AT 339 AM CDT WED JUN 19 2013 COMPLICATED FORECAST FOR EXTENDED...WITH MANY PERIODS OF POPS...AND SOMEWHAT LOW CONFIDENCE IN TIMING...WITH BREAKS IN PRECIP CHANCES FROM TIME TO TIME THROUGH THE REMAINDER OF THE WEEK. LARGE UPPER LEVEL LOW WILL BE DRIVER FOR PRECIPITATION CHANCES TROUGH MUCH OF THE PERIOD. LOW WILL REMAIN PRIMARILY OVER PAC NW...AND IS BEGINNING TO SLOWLY PUSH INLAND ATTM. MODELS HAVE SIGNIFICANT DISCREPANCIES OVER PLACEMENT OF LOW...BUT SHOULD COME INTO BETTER AGREEMENT AS LOW PUSHES INLAND. RIDGE REMAINS OVER IOWA THROUGH MUCH OF PERIOD...WITH SHORTWAVES PUSHING THROUGH SPARKING CONVECTION CHANCES. MODELS HAVE SIGNIFICANTLY SLOWED DOWN SHORT WAVES PROPAGATION EASTWARD...WITH FOCUS FOR DEVELOPMENT IN CENTRAL NE PUSHING INTO IOWA LATE OVERNIGHT. HAVE THEREFORE SLOWED POPS FOR OVERNIGHT...THOUGH COULD SEE SOME DEVELOPMENT AHEAD OF MAIN PRECIP BAND WITH THETA-E ADVECTION. SYSTEM IS SLOW MOVING...WITH PRECIP THROUGH THURSDAY. STRONG SHORTWAVE SET TO TRACK ACROSS NORTHERN PLAINS LATE THURSDAY. THIS WILL LIKELY BE THE FOCUS FOR SEVERE WEATHER ACROSS THE DAKOTAS...AND MAY FORM INTO MCS PUSHING ACROSS IOWA...WITH NORTHERN IOWA MOST LIKELY LOCATION OVERNIGHT THURSDAY. SEVERE WEATHER WILL BE POSSIBLE WITH THIS SYSTEM. SHORTWAVE EXPECTED TO TRACK ACROSS SOUTHERN SD/MN AND HEAVIEST PRECIP MAY STAY NORTH. NUMEROUS SHORTWAVES CONTINUE TO TRACK EAST AS UPPER LEVEL LOW REMAINS ACROSS NORTHWESTERN US. AS LOW PUSHES EASTWARD...TRACKS OF WAVES WILL LIKELY GO NORTH OF CWA...BUT MAY SEE DEVELOPMENT FURTHER SOUTH...AND HAVE KEPT POPS ACROSS THE NORTH. SOMEWHAT STRONGER WAVE PUSHES THROUGH FLOW FOR THE WEEKEND...THOUGH UPPER LEVEL LOW WILL PUSH EASTWARD AND SURFACE LOW IN WESTERN PLAINS WILL ALSO LIFT NE AT THIS TIME...AND TIMING AND LOCATION FOR PRECIPITATION CHANCES OVER THE WEEKEND IS VERY MUDDLED. AS UPPER LEVEL LOW PUSHES EAST FRONT WILL DROP ACROSS IOWA WITH PROLONGED PRECIPITATION CHANCE FOR LATE IN THE PERIOD. TEMPERATURES WILL WARM SIGNIFICANTLY UNDER THE RIDGE...WITH SURFACE SOUTHERLY FLOW. HAVE BUMPED TEMPERATURES UP WITH WAA FOR EARLY IN THE PERIOD...THOUGH MIXING MAY BE SOMEWHAT LIMITED. OVERALL...TEMPERATURES WILL WARM WITH SUMMER LIKE READINGS. && .AVIATION...19/12Z ISSUED AT 632 AM CDT WED JUN 19 2013 A SELY FLOW OF WILL BRING MOISTURE NORTH INTO THE STATE AND RESULT IN ISOLATED SHRA OVER THE WRN TAF SITES THIS MORNING. VFR CONDITIONS WILL HOLD THROUGH THE TAF PERIOD WITH MID AND HIGH LEVEL CIGS. TSRA WILL MOVE INTO WRN A TONIGHT...BUT AT THIS TIME THINKING IS THAT THE TSRA WILL REMAIN MAINLY WEST OF THE TAF SITES WITH ONLY A SMALL CHANCE OF THEM REACHING KFOD AND KDSM BY 12Z. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MS JUN 13 LONG TERM...AWB AVIATION...MS JUN 13
AREA FORECAST DISCUSSION
NWS DES MOINES IA
346 AM CDT WED JUN 19 2013 .SHORT TERM.../TODAY/... ISSUED AT 339 AM CDT WED JUN 19 2013 HIGH PRESSURE RIDGE MOVING OFF TO THE EAST NOW WITH WAA BEGINNING TO MOVE INTO WRN IA. SAT PIX SHOW AN INCREASE IN CLODS FROM DECAYING BLOWOFF CLOUDS. DEEPER MOISTURE CONVERGENCE MOVING INTO SWRN IA WILL BRING AT LEAST ISOLATED TSRA THIS MORNING AS WAA ARC LIFTS NORTHEAST ACROSS THE CWA. KEPT THE PRECIP TO THE WEST HALF HOWEVER. COMBINATION OF NAMDNG5 AND HRRR GIVES A REASONABLE PRESENTATION OF EXPECTED OUTCOME. TEMPS TODAY VERY DEPENDENT ON CLOUD COVER. FEEL THERE WILL BE ENOUGH BREAKS TO GET HIGHS A LITTLE ABOVE MOS GUID AND WARMER THAN YESTERDAY IN MOST LOCATIONS. .LONG TERM.../TONIGHT THROUGH TUESDAY/... ISSUED AT 339 AM CDT WED JUN 19 2013 COMPLICATED FORECAST FOR EXTENDED...WITH MANY PERIODS OF POPS...AND SOMEWHAT LOW CONFIDENCE IN TIMING...WITH BREAKS IN PRECIP CHANCES FROM TIME TO TIME THROUGH THE REMAINDER OF THE WEEK. LARGE UPPER LEVEL LOW WILL BE DRIVER FOR PRECIPITATION CHANCES TROUGH MUCH OF THE PERIOD. LOW WILL REMAIN PRIMARILY OVER PAC NW...AND IS BEGINNING TO SLOWLY PUSH INLAND ATTM. MODELS HAVE SIGNIFICANT DISCREPANCIES OVER PLACEMENT OF LOW...BUT SHOULD COME INTO BETTER AGREEMENT AS LOW PUSHES INLAND. RIDGE REMAINS OVER IOWA THROUGH MUCH OF PERIOD...WITH SHORTWAVES PUSHING THROUGH SPARKING CONVECTION CHANCES. MODELS HAVE SIGNIFICANTLY SLOWED DOWN SHORT WAVES PROPAGATION EASTWARD...WITH FOCUS FOR DEVELOPMENT IN CENTRAL NE PUSHING INTO IOWA LATE OVERNIGHT. HAVE THEREFORE SLOWED POPS FOR OVERNIGHT...THOUGH COULD SEE SOME DEVELOPMENT AHEAD OF MAIN PRECIP BAND WITH THETA-E ADVECTION. SYSTEM IS SLOW MOVING...WITH PRECIP THROUGH THURSDAY. STRONG SHORTWAVE SET TO TRACK ACROSS NORTHERN PLAINS LATE THURSDAY. THIS WILL LIKELY BE THE FOCUS FOR SEVERE WEATHER ACROSS THE DAKOTAS...AND MAY FORM INTO MCS PUSHING ACROSS IOWA...WITH NORTHERN IOWA MOST LIKELY LOCATION OVERNIGHT THURSDAY. SEVERE WEATHER WILL BE POSSIBLE WITH THIS SYSTEM. SHORTWAVE EXPECTED TO TRACK ACROSS SOUTHERN SD/MN AND HEAVIEST PRECIP MAY STAY NORTH. NUMEROUS SHORTWAVES CONTINUE TO TRACK EAST AS UPPER LEVEL LOW REMAINS ACROSS NORTHWESTERN US. AS LOW PUSHES EASTWARD...TRACKS OF WAVES WILL LIKELY GO NORTH OF CWA...BUT MAY SEE DEVELOPMENT FURTHER SOUTH...AND HAVE KEPT POPS ACROSS THE NORTH. SOMEWHAT STRONGER WAVE PUSHES THROUGH FLOW FOR THE WEEKEND...THOUGH UPPER LEVEL LOW WILL PUSH EASTWARD AND SURFACE LOW IN WESTERN PLAINS WILL ALSO LIFT NE AT THIS TIME...AND TIMING AND LOCATION FOR PRECIPITATION CHANCES OVER THE WEEKEND IS VERY MUDDLED. AS UPPER LEVEL LOW PUSHES EAST FRONT WILL DROP ACROSS IOWA WITH PROLONGED PRECIPITATION CHANCE FOR LATE IN THE PERIOD. TEMPERATURES WILL WARM SIGNIFICANTLY UNDER THE RIDGE...WITH SURFACE SOUTHERLY FLOW. HAVE BUMPED TEMPERATURES UP WITH WAA FOR EARLY IN THE PERIOD...THOUGH MIXING MAY BE SOMEWHAT LIMITED. OVERALL...TEMPERATURES WILL WARM WITH SUMMER LIKE READINGS. && .AVIATION...19/06Z ISSUED AT 1209 AM CDT WED JUN 19 2013 VFR/MOSTLY CLEAR CONDITIONS WILL CONTINUE INTO EARLY WED MORNING. THE ONLY CONCERN IS WHETHER MVFR FOG COULD DEVELOP TOWARD DAYBREAK. TEMPS AND DEWPOINTS ARE GENERALLY A BIT LOWER/HIGHER RESPECTIVELY FROM THIS TIME YESTERDAY SO THERE IS THAT POTENTIAL WITH LIGHT E/SE WIND. HAVE ADDED MENTION IN CLIMATOLOGICALLY FAVORED LOCATIONS WHICH ARE ALSO SUPPORTED BY MOS GUIDANCE...WHICH ENDS UP TO BE EVERYWHERE OUTSIDE OF KDSM. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MS LONG TERM...AWB AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1018 PM CDT THU JUN 20 2013 ...UPDATED DISCUSSION OF OVERNIGHT PRECIPITATION POTENTIAL... .UPDATE... ISSUED AT 1009 PM CDT THU JUN 20 2013 A FEW RECENT RUNS OF HI RES NEAR TERM MODELS...THE HRRR IN PARTICULAR...HAVE INDICATED POTENTIAL FOR THUNDERSTORMS OVER WESTERN KANSAS TO GRADUALLY WORK INTO NORTH CENTRAL KANSAS...AND PERHAPS CLIPPING THE CONCORDIA AND BELLEVILLE AREAS AROUND SUNRISE. THE ONGOING DEVELOPMENT IN WESTERN KANSAS AROUND 10 PM SEEMS TO HAVE BEEN PICKED UP WELL BY THESE MODEL RUNS...AND SEEMS TO BE LINKED TO A CONVERGENT ZONE ON THE NOSE OF AN INTENSIFYING LOW LEVEL JET EVIDENT ON DDC WIND PROFILE. WHILE THERE IS AMPLE INSTABILITY ACROSS MUCH OF CENTRAL AND EASTERN KANSAS...5000 J/KG SBCAPE WITH THE 00Z TOP SOUNDING...IT ALSO APPEARS TO BE CAPPED OFF. THE ONLY LIFTING MECHANISM CAPABLE OF OVERCOMING THIS CAP WOULD SEEM TO BE THE CONVERGENCE ALONG THE NOSE OF THE LLJ. THE LOCATION OF THIS FAVORED ASCENT IS FORECAST TO EXTEND FROM ITS CURRENT LOCATION IN WEST CENTRAL KANSAS...UP INTO SOUTH CENTRAL AND SOUTHEAST NEBRASKA. WITH THAT IN MIND...STILL FEEL PRETTY COMFORTABLE IN HAVING NO MENTION OF TSTORMS IN THE FORECAST FOR THE OVERNIGHT AND EARLY MORNING HOURS. HOWEVER...THE 10 TO 14 PERCENT CHANCE OF PRECIP OVER NORTH CENTRAL KANSAS IS THERE FOR A REASON AS THERE IS STILL A VERY SMALL CHANCE THAT A STORM OR TWO COULD MOVE INTO THAT REGION AROUND SUNRISE. WILL CONTINUE TO MONITOR THE SITUATION AND MAKE ADJUSTMENTS IF NEEDED. BARJENBRUCH && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 305 PM CDT THU JUN 20 2013 20Z WATER VAPOR SHOWS A CLOSED UPPER LOW OVER THE NORTHERN ROCKIES AND PACIFIC NORTHWEST AND A SHORTWAVE ROUNDING AN UPPER RIDGE AND MOVING INTO THE UPPER MIDWEST/GREAT LAKES REGION. SREF AND RAP MODELS SHOW THE UPPER RIDGE OVER THE SOUTHERN PLAINS TO BE GRADUALLY STRENGTHENING WITH HEIGHTS RISING OVER CENTRAL AND EASTERN KS. AT THE SURFACE...OBS SHOW A TROUGH AXIS FROM THE SOUTHERN HIGHS PLAINS NORTH INTO THE NORTHERN PLAINS. THIS HAS CAUSED A STRENGTHENING SURFACE PRESSURE GRADIENT AND GUSTY SOUTH WINDS ACROSS THE REGION. FOR TONIGHT AND FRIDAY...THE NAM HAS NOT SHOWN VERY GOOD PERFORMANCE RECENTLY WITH ITS HANDLING OF CONVECTION. THE OTHER SOLUTIONS INCLUDING THE GFS/ECMWF/GEM/ARW SUGGEST THAT WITH THE STRENGTHENING UPPER LEVEL RIDGE ACROSS THE FORECAST AREA PRECIP WILL REMAIN NORTH AND EAST OF THE FORECAST AREA THROUGH FRIDAY. SO WITH THIS IN MIND HAVE OPTED TO IGNORE THE NAM SOLUTION AND THE QPF IT BRINGS THROUGH. THERE DOES NOT APPEAR TO BE ANY STRONG FORCING IN THE FORM OF A SHORTWAVE OR STRONG ISENTROPIC LIFT OVER THE AREA TO GENERATE PRECIP...SO THE FORECAST WILL REMAIN DRY THROUGH FRIDAY. LOWS TONIGHT SHOULD BE QUITE MILD WITH THE STRONG SURFACE PRESSURE GRADIENT KEEPING WINDS UP THROUGH THE NIGHT. LOWS ARE EXPECTED TO BE IN THE LOWER TO MID 70S. HIGHS FRIDAY LOOK TO BE RATHER SIMILAR TO TODAYS BASED ON THE 850 TEMPS OF THE GFS/ECMWF/GEM. WITH THE BOUNDARY LAYER MIXING TO AROUND 850MB...HIGHS SHOULD BE IN THE LOWER TO MID 90S. WINDS FRIDAY LOOK TO BE QUITE BREEZY ONCE AGAIN WITH THE STRONG PRESSURE GRADIENT RIGHT OVER THE FORECAST AREA. CONSIDERED THE NEED FOR A WIND ADVISORY FRIDAY AFTERNOON BUT DECIDED THE LIKELIHOOD OF ADVISORY LEVEL WINDS WAS NOT HIGH ENOUGH FOR AN ADVISORY AT THIS TIME. THE NAM IS THE ONLY MODEL THAT HAS A REALLY STRONG PRESSURE GRADIENT AND SUSTAINED WINDS AROUND 30MPH. SO GIVEN ITS RECENT TRACK RECORD OVER THE LAST DAY OR TWO...DO NOT FEEL COMFORTABLE PUTTING MUCH STOCK INTO IT. LATER SHIFTS CAN REEVALUATE. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 305 PM CDT THU JUN 20 2013 FRIDAY NIGHT THROUGH SUNDAY... FRIDAY NIGHT A FRONTAL BOUNDARY IS EXPECTED TO MOVE INTO NORTHERN NEBRASKA AND NORTHEAST COLORADO. THUNDERSTORMS MAY DEVELOP ALONG THE BOUNDARY IN NEBRASKA...BUT ARE EXPECTED TO REMAIN WELL TO THE NORTH OF THE CWA. THERMAL RIDGE WILL REMAIN IN PLACE ON SATURDAY ACROSS THE CENTRAL PLAINS. THE UPPER RIDGE OVER THE CENTRAL PLAINS WILL BREAKDOWN AS A SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN ROCKIES AND NORTHERN PLAINS. THE FRONTAL BOUNDARY WILL SLIDE A LITTLE FURTHER SOUTHEAST SATURDAY NIGHT AND SUNDAY. SOME SCATTERED THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT IN NEBRASKA AND COULD AFFECT THE NORTHERN CWA. BETTER FORCING WILL REMAIN TO THE NORTH OF THE CWA. TEMPERATURES WILL REMAIN ON THE HOT SIDE WITH HIGHS IN THE 90S SATURDAY AND SUNDAY. LOWS IN THE LOWER TO MIDDLE 70S ARE EXPECTED. HEAT INDICES IN THE UPPER 90S TO LOW 100S ARE POSSIBLE EACH DAY. SUNDAY NIGHT THROUGH THURSDAY... ON SUNDAY THE MAIN SHORTWAVE TROUGH WILL BE LIFTING NORTHEAST THROUGH THE NORTHERN PLAINS WHILE THE TRAILING FRONT PUSHES SOUTH INTO EASTERN NEBRASKA AND WESTERN KANSAS. MEANWHILE AN EMBEDDED SHORTWAVE IN THE SOUTHWEST FLOW WILL SLIDE ACROSS THE REGION AIDING IN THUNDERSTORM DEVELOPMENT ALONG AND NEAR THE SFC FRONT. IT DOES APPEAR THAT THE BETTER CHANCES FOR STORMS WILL BE ACROSS AREAS NORTH OF INTERSTATE 70 SUNDAY NIGHT. AN UPPER LEVEL RIDGE WILL THEN BUILD OVER THE PLAINS CAUSING HIGH TEMPERATURES TO REACH THE MID TO UPPER 90S WITH HEAT INDICES IN THE LOW 100S MONDAY THROUGH THE PERIOD. THE RIDGE WILL CONTINUE TO BUILD MORE ACROSS THE WESTERN US WHICH WILL ALLOW THE LONGWAVE TROUGH TO DIG SOUTH ACROSS THE EASTERN US. THIS WILL BRING A FRONT INTO THE REGION ON WEDNESDAY AND THURSDAY INCREASES CHANCES FOR PRECIP. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 608 PM CDT THU JUN 20 2013 VFR CONDITIONS ARE IN STORE FOR THE ENTIRE FORECAST. SOUTH WINDS SHOULD LOSE GUSTS BY AROUND 02Z ALTHOUGH THERE COULD BE OCCASIONAL GUSTS OVERNIGHT. WILL COME CLOSE TO LOW LEVEL WIND SHEAR CRITERIA WITH 50 KTS FROM THE SOUTH NEAR 1000 FEET. SURFACE WINDS WILL GUST TO NEAR 30 KTS ON FRIDAY. BARJENBRUCH && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARJENBRUCH SHORT TERM...WOLTERS LONG TERM...SANDERS/WOYNICK AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS WICHITA KS
330 PM CDT WED JUN 19 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 329 PM CDT WED JUN 19 2013 FORECAST HIGHLIGHTS FOCUS AROUND THUNDERSTORM CHANCES TONIGHT THROUGH THURSDAY MORNING...WITH HOT AND MOSTLY DRY SUMMER WEATHER LIKELY LATE THIS WEEK THROUGH AT LEAST EARLY TO MID NEXT WEEK. DIFFICULT THUNDERSTORM FORECAST TONIGHT-THURSDAY MORNING. CURRENTLY A WEAK 700-500MB RIPPLE IS ADVANCING EAST ACROSS EASTERN KS. GIVEN THIS FEATURE ALONG WITH THE RELATIVELY UNCAPPED AIRMASS IN PLACE...CANNOT RULE OUT A FEW ISOLATED HIT-AND-MISS THUNDERSTORMS LATE THIS AFTERNOON THROUGH ABOUT SUNSET. NOT ANTICIPATING WIDESPREAD COVERAGE THOUGH. FOCUS THEN TURNS TO LATER TONIGHT WHEN EASTERN FRINGE OF ADVANCING ELEVATED MIXED LAYER APPROACHES FROM THE WEST...DRAMATICALLY INCREASING 800-600MB WARM/MOIST ADVECTION FROM WEST TO EAST...RESULTING IN A CHANCE OF THUNDERSTORMS AFTER 2-3AM WEST OF THE FLINT HILLS. THE HIGHEST CHANCES MAY BE OVER CENTRAL/EAST-CENTRAL KS WHERE NOSE OF MOISTURE TRANSPORT IS POINTING. NAM AND GFS ELEVATED INSTABILITY PROGS INDICATE ~2500 J/KG INSTABILITY FROM PARCELS ROOTED AROUND 800MB...ALONG WITH AROUND 30 KTS OF EFFECTIVE SHEAR...INDICATING STRONG TO SEVERE HAILERS ARE POSSIBLE WITH ANY STORMS THAT CAN FORM. HOWEVER...UNSURE ON HOW WIDESPREAD ACTIVITY WILL BE GIVEN THE CONVECTION-SUPPRESSING AFFECTS OF MID/UPPER RIDGING DEVELOPING ACROSS THE REGION OVERNIGHT...WHICH MAY BE A REASON WHY THE LATEST HRRR AND KF NAM STRUGGLE IN DEVELOPING OVERNIGHT CONVECTION. AGAIN...HIGHEST POTENTIAL MAY REMAIN OVER CENTRAL/EAST-CENTRAL KS AND POINTS NORTH. NEVERTHELESS...HELD ONTO MODEST CHANCE POPS GIVEN STRENGTH OF ISENTROPIC ASCENT/MOISTURE TRANSPORT. ANTICIPATING ACTIVITY TO FESTER MUCH OF THU MORNING EAST OF I-135...AND POSSIBLY INTO THE AFTERNOON EAST OF THE FLINT HILLS. ADK && .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 329 PM CDT WED JUN 19 2013 OTHERWISE...BUILDING MID/UPPER RIDGE WILL LIKELY SUPPRESS WIDESPREAD THUNDERSTORM CHANCES FROM FRIDAY THROUGH AT LEAST EARLY TO MID NEXT WEEK...AND ALLOW ABOVE NORMAL SUMMER HEAT TO BUILD ACROSS THE REGION. CANNOT COMPLETELY RULE OUT A FEW ISOLATED HIT-AND-MISS AFTERNOON-EVENING THUNDERSTORMS FRI-SAT...AS ECMWF HINTS AT SUBTLE WEAKNESSES PROGRESSING OVER THE AREA...BUT THINKING THIS THREAT WILL BE QUITE ISOLATED. OTHERWISE...WITH GFS ENSEMBLES AND OPERATIONAL ECMWF BUILDING RIDGE INTO EARLY/MID NEXT WEEK...CONFIDENCE IS HIGH THAT ABOVE NORMAL SUMMER HEAT IN THE 90S TO LOW 100S WILL PREVAIL REGIONWIDE...WARMEST GENERALLY OVER THE WESTERN HALF OF KS...WITH OVERNIGHT LOWS IN THE 70S ALL AREAS. ADK && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1244 PM CDT WED JUN 19 2013 THE MAIN AVIATION FORECAST CONCERN ARE THE THUNDERSTORM CHANCES OVERNIGHT. VFR CONDITIONS ARE EXPECTED TO PREVAIL...BUT LOW CUMULUS CLOUDS COULD IMPACT THE TERMINALS THIS AFTERNOON. CEILINGS HAVE LIFTED TO 3500+ KFT THIS AFTERNOON AND EXPECT THAT TREND TO CONTINUE. A SLIGHT CHANCE OF THUNDERSTORM EXISTS THIS AFTERNOON AND EARLY EVENING...BUT CONFIDENCE IS LOW ON THAT AND HAVE LEFT OUT ANY MENTION AT THIS TIME AND WILL ALLOW FOR AMENDMENTS IF SOMETHING DEVELOPS. HOWEVER...CONFIDENCE IS HIGHER FOR OVERNIGHT CONVECTION AND HAVE A VCTS AT ALL TERMINALS FOR STORMS. SOUTHERLY WINDS ARE A BIT WEAKER THAN ANTICIPATED...BUT STILL EXPECTING GUSTS THIS AFTERNOON AND THEN AGAIN TOMORROW AFTERNOON WITH MIXING. BILLINGS && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 70 90 73 95 / 40 40 10 10 HUTCHINSON 69 93 73 96 / 40 30 10 10 NEWTON 68 88 73 94 / 40 50 10 10 ELDORADO 69 87 72 92 / 40 40 10 10 WINFIELD-KWLD 70 89 73 93 / 30 40 10 10 RUSSELL 68 97 73 98 / 40 10 10 10 GREAT BEND 68 97 72 97 / 30 10 10 10 SALINA 70 91 74 96 / 50 50 10 10 MCPHERSON 69 91 73 96 / 40 50 10 10 COFFEYVILLE 69 85 73 91 / 30 40 10 10 CHANUTE 68 84 72 90 / 30 40 10 10 IOLA 68 84 71 90 / 30 40 10 10 PARSONS-KPPF 69 84 73 90 / 30 40 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
303 PM CDT WED JUN 19 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 301 PM CDT WED JUN 19 2013 19Z WATER VAPOR IMAGERY SHOWS A CLOSED UPPER LEVEL LOW OVER THE PACIFIC NORTHWEST WITH A SHORTWAVE ROTATING THROUGH THE TROUGH OVER THE GREAT SALT LAKE. DOWNSTREAM THERE WAS A BROAD UPPER LEVEL RIDGE OVER THE PLAINS WITH A WEAK DISTURBANCE NEAR THE MIDDLE MO RIVER VALLEY MOVING EAST. AT THE SURFACE...A TROUGH OF LOW PRESSURE WAS GRADUALLY DEEPENING ALONG THE LEE OF THE CENTRAL ROCKIES. THIS HAS ALLOWED FOR SOUTHERLY WINDS TO INCREASE. ANY REMNANT OUTFLOW BOUNDARIES FROM EARLY THIS MORNING HAVE BECOME ILL-DEFINED. FOR LATE THIS AFTERNOON AND THIS EVENING...LAPS DATA AND RAP ANALYSIS SHOWS A CONDITIONALLY UNSTABLE AIRMASS OVER THE FORECAST AREA WITH CAPE VALUES AROUND 2000 J/KG...AND VERY LIMITED INHIBITION LEFT. REALLY THE ONLY THING NEEDED FOR CONVECTION IS SOME SORT OF LIFT TO GET PARCELS MOVING UP TO BECOME POSITIVELY BUOYANT. LOW LEVEL CONVERGENCE APPEARS TO BE RELATIVELY WEAK WITH RAP PROGS NOT SHOWING MUCH INCREASE IN LOW LEVEL CONVERGENCE THROUGH SUNSET. WITH NO REAL LARGE SCALE FORCING TO SPEAK OF...THINK CONVECTION IS LIKELY TO BE ISOLATED IF IT DOES DEVELOP. THERE IS SOME SIGNS OF VERTICAL DEVELOPMENT IN THE CU FIELD ACROSS SOUTHEAST NEB. IF A STORM IS ABLE TO DEVELOP AN OUTFLOW...THE GUST FRONT COULD BE ENOUGH LIFT FOR FURTHER DEVELOPMENT. OTHERWISE THINK THE BETTER CHANCES FOR PRECIP WILL BE LATE TONIGHT AND THROUGH THE MORNING THURSDAY. MOST GUIDANCE SHOWS DECENT MID LEVEL THETA-E ADVECTION WITH THE LOW LEVEL JET INCREASING OVER CENTRAL KS. FORECAST SOUNDINGS SHOW INCREASING MOISTURE ALONG THIS GRADIENT AS MID LEVEL LAPSE RATES STEEPEN TO AROUND 7 C/KM. THEREFORE THERE COULD BE SOME ELEVATED STORMS DEVELOP OVERNIGHT AND MOVE ACROSS EASTERN KS THROUGH THE MORNING THURSDAY. LOW CONFIDENCE IN LOCATION OF THE ELEVATED DEVELOPMENT AND WHERE IT MIGHT TRACK PRECLUDE INCREASING POPS FROM THE PREV FORECAST. SO HAVE CONTINUED WITH 40 TO 50 PERCENT CHANCES INTO THURSDAY MORNING. THINK IF ELEVATED STORMS FORM...THAT THE RESULTING MCS SHOULD BE MOVING OFF TO THE SOUTHEAST OR DIMINISHING WITH THE WEAKENING OF THE LOW LEVEL JET BY THE AFTERNOON AND THE POP FORECAST REFLECTS A DOWNWARD TREND IN CHANCES THROUGH THE AFTERNOON. SOUTHERLY WINDS AND SOME MODEST MIXING OF THE BOUNDARY LAYER SHOULD KEEP LOWS TONIGHT IN THE UPPER 60S TO AROUND 70. HIGHS THURSDAY MAY BE A LITTLE MORE TRICKY AS THE MODELS SHOW WEAK MIXING OF THE BOUNDARY LAYER DUE TO COLD POOL PUT DOWN BY THE NOCTURNAL CONVECTION. EVEN IF THERE ARE STORMS...DO NOT THINK THEY WILL PERSIST FOR THE WHOLE DAY AND WE SHOULD STILL SEE SOME GOOD INSOLATION IN THE AFTERNOON WITH SOUTH WINDS INCREASING. THEREFORE HAVE HIGHS FOR THURSDAY IN THE MID 80S ACROSS EAST CENTRAL KS WHERE CLOUDS AND PRECIP COULD POTENTIALLY HANG ON LONGER IN THE MORNING...TO AROUND 90 IN NORTH CENTRAL KS WHERE SUNSHINE SHOULD BREAK OUT EARLIER IN THE DAY. WOLTERS .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 301 PM CDT WED JUN 19 2013 THURSDAY NIGHT AND FRIDAY...SOME CONCERN AS TO CONVECTION REDEVELOPING LATE THURSDAY NIGHT/EARLY FRIDAY MORNING. THURSDAY AFTERNOON THUNDERSTORM COMPLEX EXPECTED TO DEVELOP ALONG SFC WARM FRONT DRAPED OVER CENTRAL NEBRASKA AND WESTERN IOWA. NAM FORECASTED CONVECTIVELY GENERATED COLD POOL MAY PUSH FRONTAL BOUNDARY SOUTH POTENTIALLY OVER SOUTHERN NEBRASKA/NORTHEAST KANSAS BY FRIDAY MORNING. 305K-320K ISENTROPIC LIFT...55KT LLJ AND SOME MID-LEVEL FRONTOGENETICAL FORCING COULD BE ENOUGH TO PROMOTE REDEVELOPMENT OF CONVECTION MAINLY OVER THE FAR NORTHEASTERN SECTIONS OF THE STATE. UPPER LEVEL FORCING IS LACKING HOWEVER...LEAVING REDUCED CONFIDENCE. LEFT FRIDAY AFTERNOON DRY ATTM. HOWEVER...IF CONVECTION DEVELOPS DURING THE EARLY MORNING HOURS...OUTFLOW BOUNDARIES MAY STILL BE PRESENT DURING THE AFTERNOON ACROSS THE CWA. WITH A H5 SHRTWV PROGGED TO ENTER THE STATE FRIDAY AFTERNOON...THIS MAY BE ENOUGH TO REFIRE CONVECTION DURING THE AFTERNOON HOURS. TEMPERATURES WILL BE ON THE INCREASE OVER THE COMING WEEK AS LARGE UPPER LEVEL RIDGE BEGINS TO BUILD INTO THE CENTRAL U.S. HEAT INDICES COULD REACH OVER 100 FRIDAY AFTERNOON. FRIDAY NIGHT THROUGH THE REST OF THE WEEK...RIDGE CONTINUES TO BROADEN ACROSS THE PLAINS ON SATURDAY WITH THE RIDGE AXIS EXTENDING FROM EASTERN COLORADO/WESTERN KANSAS THROUGH NORTHEAST KANSAS AND INTO THE UPPER MIDWEST. SLIGHT CHANCES FOR THUNDERSTORMS WILL BE POSSIBLE ALONG THE NORTHERN SIDE OF THE RIDGE ON SUNDAY. CHANCES INCREASE FOR LOCATIONS NORTH OF I70 SUNDAY NIGHT AS AN H5 SHRTWV TRAVELS NORTHEAST ALONG THE NORTHERN PERIPHERY OF THE RIDGE. COLD FRONT TRIES TO PUSH SOUTHEAST INTO KANSAS ON TUESDAY...BUT UPPER LEVEL SUPPORT FOR THE FRONT MOVES INTO CANADA BY MONDAY AFTERNOON. OTHERWISE...CENTRAL PLAINS RIDGE BROADENS AND COVERS MUCH OF THE CONUS BY TUESDAY. RIDGE BEGINS TO AMPLIFY OVER THE WESTERN U.S. BY WEDNESDAY AFTERNOON SETTING UP THE SUMMER TIME PATTERN OF NORTHWEST FLOW OVER THE CENTRAL PLAINS. HIGHS WILL BE IN THE LOW TO MID 90`S...AND LOWS WILL BE IN THE 60`S AND 70`S. BYRNE && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1240 PM CDT WED JUN 19 2013 BECAUSE THERE IS NO FORCING OR SURFACE FEATURE FOR CONVECTION TO FORM...THINK ANY DIURNALLY DRIVEN STORMS WILL BE ISOLATED IN COVERAGE AND HAVE REMOVED THE VCTS FROM THIS AFTERNOON SINCE PREDICTABILITY IS VERY LOW AT THIS POINT. THERE DOES APPEAR TO BE SOME THETA-E ADVECTION OVERNIGHT WITH MID LEVEL LAPSE RATES AROUND 7 C/KM. THIS MAY BE ENOUGH FOR ELEVATED STORMS TO DEVELOP AFTER 06Z. CONFIDENCE IS MARGINAL...BUT WITH ALL THE GUIDANCE SHOWING SOME PRECIP...WILL INCLUDE A VCTS MENTION THROUGH THE MORNING THURSDAY. OTHERWISE ANTICIPATE CONDITIONS TO REMAIN VFR WITH CU FIELD FORMING AROUND 4 KFT. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...WOLTERS LONG TERM...BYRNE AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS WICHITA KS
1245 PM CDT WED JUN 19 2013 .UPDATE... ISSUED AT 1244 PM CDT WED JUN 19 2013 UPDATED THE FORECAST FOR CURRENT TRENDS...ESPECIALLY REGARDING PRECIPITATION POTENTIAL. HAVE DECREASED CHANCES FOR PRECIPITATION DURING THE AFTERNOON HOURS. DID KEEP IN A SLIGHT CHANCE...WITH THE UPPER PV ENERGY MOVING OVER THE STATE AND THE MOISTURE ABUNDANCE...CANNOT RULE OUT A THUNDERSTORM DEVELOPING IN THE WARM AIR ADVECTION SCHEME...BUT CONFIDENCE IS NOT HIGH ON ORGANIZED AND WIDESPREAD CONVECTION THROUGH THE REMAINDER OF THE AFTERNOON. FEEL BETTER CHANCES WILL BE OVERNIGHT...AND WILL LET AFTERNOON FORECAST TOUCH ON THAT. BILLINGS && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM CDT WED JUN 19 2013 TOUGH FORECAST WAS MADE EVEN MORE DIFFICULT DUE TO THE UNAVAILABILITY OF HRRR/00 UTC ECMWF AND RUC AFTER 0600 UTC DUE TO PROBLEMS UPSTREAM. NONE OF THE REMAINDER OF AVAILABLE GUIDANCE HAD MUCH OF A HANDLE ON ONGOING CONVECTION. NAM WAS PARTICULARLY SUSPECT...ESPECIALLY WITH INITIALIZATION OF 850MB MOISTURE. BASED ON 0000 UTC RADIOSONDE OBSERVATION AND OBSERVATIONAL DATASETS... SEE LITTLE REASON WHY HIGH PLAINS CONVECTION WILL NOT CONTINUE TO ROLL EAST DURING THE DAY AIDED BY WARM AIR ADVECTION...INFLUX OF MOISTURE AND SHORTWAVE. EFFECTS ON TEMPERATURES/WINDS DURING THE DAY WILL BE DIFFICULT TO PIN DOWN. THINKING THAT PRECIPITATION WILL TRANSITION TO EASTERN HALF BY LATE AFTERNOON...WITH LULL IN THE WESTERN HALF AROUND SUNSET. SEE NO REASON WHY STORMS WILL NOT DEVELOP OVER THE HIGH PLAINS AGAIN TONIGHT AND ROLL EAST. THU REMAINS PROBLEMATIC...AS IT IS UNCLEAR HOW WIDESPREAD CONVECTION WILL BE OR LOW LONG IT WILL LINGER. LARGE POTENTIAL FOR ERROR ON ALL FACETS OF THIS FORECAST. HAVE LEANED A BIT TOWARDS THE GFS WHICH WAS THE LEAST WRONG GUIDANCE OUT OF THE BOX. HAVE STAYED THE COURSE WITH DRY/WARMER/WINDIER CONDITIONS ON FRIDAY. -HOWERTON .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 330 AM CDT WED JUN 19 2013 THE WARMING TREND WILL CONTINUE INTO THE WEEKEND AS RIDGE BUILDS. SOME HINT ON THE LATEST AVAILABLE GUIDANCE THAT FRONT MAY SAG CLOSE ENOUGH TO BRING SMALL CHANCES FOR PRECIPITATION ON SUN/SUN NIGHT. NOT OVERLY OPTIMISTIC ABOUT THESE CHANCES BUT IN ABSENCE OF 0000 UTC ECMWF WILL NOT MAKE SIGNIFICANT CHANGES. HAVE HEDGED TEMPERATURES UP A BIT ABOVE INITIALIZATION GRIDS BASED ON LAST WARM PERIOD AND BEST GUIDANCE AT THESE TIME RANGES. TEMPERATURES IN TRIPLE DIGITS APPEAR PROBABLE IN CENTRAL KS BY EARLY NEXT WEEK. -HOWERTON && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1244 PM CDT WED JUN 19 2013 THE MAIN AVIATION FORECAST CONCERN ARE THE THUNDERSTORM CHANCES OVERNIGHT. VFR CONDITIONS ARE EXPECTED TO PREVAIL...BUT LOW CLUMULUS CLOUDS COULD IMPACT THE TERMINALS THIS AFTERNOON. CEILINGS HAVE LIFTED TO 3500+ KFT THIS AFTERNOON AND EXPECT THAT TREND TO CONTINUE. A SLIGHT CHANCE OF THUNDERSTORM EXISTS THIS AFTERNOON AND EARLY EVENING...BUT CONFIDENCE IS LOW ON THAT AND HAVE LEFT OUT ANY MENTION AT THIS TIME AND WILL ALLOW FOR AMENDMENTS IF SOMETHING DEVELOPS. HOWEVER...CONFIDENCE IS HIGHER FOR OVERNIGHT CONVECTION AND HAVE A VCTS AT ALL TERMINALS FOR STORMS. SOUTHERLY WINDS ARE A BIT WEAKER THAN ANTICIPATED...BUT STILL EXPECTING GUSTS THIS AFTERNOON AND THEN AGAIN TOMORROW AFTERNOON WITH MIXING. BILLINGS && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 87 70 90 73 / 30 40 30 10 HUTCHINSON 86 69 91 72 / 30 50 20 10 NEWTON 86 68 89 72 / 40 40 30 10 ELDORADO 86 69 88 73 / 30 40 40 10 WINFIELD-KWLD 87 70 89 73 / 30 40 30 10 RUSSELL 87 68 94 71 / 50 50 10 10 GREAT BEND 87 68 93 72 / 50 50 10 10 SALINA 88 70 90 75 / 40 50 30 10 MCPHERSON 86 69 90 72 / 40 50 30 10 COFFEYVILLE 88 69 86 73 / 20 30 30 10 CHANUTE 87 68 84 72 / 20 30 30 10 IOLA 87 68 83 71 / 20 30 30 10 PARSONS-KPPF 87 69 84 72 / 20 30 30 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1131 AM MDT WED JUN 19 2013 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 402 AM MDT WED JUN 19 2013 MAIN FORECAST PROBLEM THUNDERSTORM COVERAGE/CHANCES THROUGH PERIOD WITH HOW HOT DOES IT GET THURSDAY AND FRIDAY. SATELLITE CONTINUING TO SHOW AN AMPLIFIED/BLOCKY/COMPLICATED UPPER FLOW FROM THE EASTERN PACIFIC INTO THE CENTRAL PORTION OF THE COUNTRY. UPPER LOW HAS MOVED CLOSER TO THE PACIFIC NORTHWEST WITH WEST TO SOUTHWEST FL0W ALOFT SPREADING ACROSS OUR AREA. COLD FRONT REMAINS WELL TO OUR SOUTH AND IS DRAPED UP AGAINST THE COLORADO FRONT RANGE. LARGE COMPLEX OF THUNDERSTORMS HAS PRODUCED A SIGNIFICANT COLD POOL AND HAS SENT UP MESOSCALE/CONVERGENT BOUNDARIES ACROSS DIFFERENT PORTIONS OF THE REGION. MODELS INITIALIZED FINE AT JET LEVEL. THE NAM/ECMWF LOOKED TO HAVE INITIALIZED THE WORST ON THE MID LEVELS WITH THE UKMET/CANADIAN/GFS/SREF DOING ABOUT THE SAME. NAM WAS A LITTLE WARM AT 700 MB WITH THE GFS AND UKMET BETTER. SREF AND GFS WERE DOING LITTLE BETTER THAN THE NAM AND CANADIAN ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...DUE TO THE OVERNIGHT THUNDERSTORM COMPLEX THAT WENT THROUGH...MESOSCALE BOUNDARIES/CONVERGENCE DO ABOUND. SATELLITE AND UPPER AIR ANALYSIS SHOWING A COUPLE OF WEAK SHORTWAVES TO OUR WEST PLUS A WARMER AND DRIER MID LEVEL AIR MASS/EML MOVING IN FROM THE WEST. NEAR 12Z THE LEFT FRONT QUADRANT OF SOUTHERN JET WILL BE AFFECTING THE SOUTHWEST PORTION OF THE AREA. IT STAYS NEAR THE SOUTHERN PORTION OF THE AREA THROUGH AS SLOWLY PROGRESSES SOUTH AWAY FROM THE AREA. VERY UNCERTAIN PRECIPITATION FORECAST FOR THE DAY...ESPECIALLY THIS MORNING...WITH MESOSCALE FEATURES BEING A BIG INFLUENCE. CONVECTIVE CIRCULATION IS LOCATED OVER THE EASTERN PORTION OF THE AREA. ONE OF THOSE OUTFLOW BOUNDARIES LIES ACROSS THE NORTHEAST PORTION. ALL MODELS ESPECIALLY THE RAP REDEVELOPS A SIGNIFICANT PRECIPITATION AREA OVER THE NORTHEAST TO EAST PORTION OF THE AREA THIS MORNING. CONSIDERING THAT THE RAP HAS BEEN CONSISTENT FOR A COUPLE OF RUNS... MATCHES UP WITH WHERE THE BOUNDARY IS RIGHT NOW AND THAT THUNDERSTORMS HAVE REDEVELOPED ALREADY IN THE SAME GENERAL AREA... WILL RAISE POPS TO A HIGH CHANCE THIS MORNING AND CONTINUE TO MONITOR. THAT CIRCULATION AND PRECIPITATION LOOK TO EXIT THE AREA AROUND THE MIDDLE OF THE DAY. THE AIR MASS LOOKS TO RELOAD WITH EMPHASIS SHIFTING BACK TO THE WEST. SURFACE TROUGH STILL REMAINS TO THE WEST OF THE AREA. WHAT LOOKS TO BE A DRYLINE SETS UP OVER THE FAR WEST WITH THE INSTABILITY AXIS SETTING NEAR THE COLORADO AND KANSAS BORDER. THE FAR WESTERN MAY BE CAPPED THIS AFTERNOON. SHORTWAVE TROUGH MOVES IN FROM THE WEST AND EXPECT THUNDERSTORMS TO DEVELOP NEAR OR JUST TO THE EAST OF THE COLORADO BORDER. THESE STORMS SHOULD PROGRESS TO THE EAST THROUGH THE NIGHT AS THE SHORTWAVE MOVES TOWARD THE EAST AND THE LOW LEVEL JET DEVELOPS IN THE EASTERN THIRD. DO NOT HAVE A GOOD FEEL WITH THE HIGH TEMPERATURES. IT IS POSSIBLE WITH THE WET GROUND AND ONGOING CLOUD COVER AND PRECIPITATION COULD CAUSE TEMPERATURES TO BE COOLER...ESPECIALLY IN THE EAST. THURSDAY/THURSDAY NIGHT...INTERESTING FORECAST FOR THIS DAY. 700 MB TEMPERATURES REMAIN RATHER HIGH THROUGH THE DAY...WITH THE LOWEST AND CAP BREAKABLE TEMPERATURES IN THE NORTHERN AND EASTERN PORTIONS OF THE AREA. BY LATE AFTERNOON...EITHER A WEAK COOL FRONT OR SURFACE TROUGH SAGS INTO THE NORTHERN PORTION OF THE AREA WITH WHAT LOOKS TO BE A DRYLINE JUST TO THE WEST OF THE SOUTHEAST CORNER. AT THE SAME TIME A SHORTWAVE TROUGH APPROACHES FROM THE SOUTHWEST. ALL THESE FEATURES PROGRESS NORTH AND EAST THROUGH THE EVENING. BY LATE IN THE AFTERNOON A WEAK LEFT FRONT QUADRANT LOOKS TO BE JUST SOUTH OF THE FORECAST AREA. THIS LIFT MOVES SLOWLY NORTH THROUGH THE EVENING AND WILL BE AFFECT THE SOUTHEAST QUARTER BY LATE IN THE NIGHT. MODELS ARE GENERATING SOME LIGHT QPF EVEN WITH WHAT LOOKS TO BE A DEEP DRY LAYER AND HIGH BASES. BELIEVE THERE IS ENOUGH HERE TO INCLUDE A LOW SLIGHT CHANCE. HOWEVER...COULD SEE THINGS TOTALLY CAPPED OR BE ABLE TO BREAK LOOSE. ALONG AND NORTH OF THE BOUNDARY THE TEMPERATURES WILL BE SLIGHTLY COOLER...IN THE 90S. SOUTH THE BOUNDARY IT WILL BE NEAR 100 DEGREES. MODELS DO DISAGREE WITH HOW FAR SOUTH TO TAKE THE BOUNDARY. CONSIDERING THE FLOW ALOFT AND THE AIR MASS LIKE THE BOUNDARY BEING FURTHER NORTH. FRIDAY/FRIDAY NIGHT...THE CANADIAN AND ECMWF KEEP A WEAK LEFT FRONT QUADRANT OF THE JET NEAR/OVER THE EASTERN AND CENTRAL PORTION OF THE AREA THROUGH THE DAY. VERY SIMILAR SETUP TO THE DAY BEFORE EXCEPT MOST OF THE WEST AND CENTRAL PORTIONS DO LOOK CAPPED DESPITE THE SURFACE TROUGH AND DRYLINE NEAR THE SAME PLACE. THE EASTERN THIRD HAS THE LOWER 700 MB TEMPERATURES WITH THE INSTABILITY AXIS AND BEST MID LEVEL MOISTURE IN THE SAME AREA. AT THE SAME TIME A SHORTWAVE TROUGH IS COMING ACROSS. LIKED WHAT THE PREVIOUS SHIFT HAD IN THERE FOR A SLIGHT CHANCE AND ONLY MADE A SLIGHT ADJUSTMENT TO THE AREA FOR THE AFTERNOON AND EVENING HOURS. ONCE AGAIN HIGH TEMPERATURES WILL BE DETERMINED BY WHERE THE BOUNDARY SETS UP. MODEL DATA SAYS THE BOUNDARY WILL BE A LITTLE FURTHER NORTH AND SO WILL THE HOT TEMPERATURES AND TRENDED THE MAXES IN THAT DIRECTION. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 230 AM MDT TUE JUN 19 2013 STRONG SOUTHWEST FLOW ALOFT AT 500 MB WILL PERSIST THROUGHOUT THE DAY SATURDAY AS MERIDIONAL FLOW PATTERN EXISTS OVER THE CENTRAL PLAINS. INSTABILITY WILL BE PRESENT IN THE FLOW AS EMBEDDED SHORTWAVE TROUGHS ENTER INTO OUR FORECAST AREA. AN UPPER LEVEL LOW WILL PROGRESS WESTWARD OVER THE NORTHERN HIGH PLAINS AS BLOCKING RIDGE OVER THE SOUTHERN PLAINS STRENGTHENS SATURDAY EVENING INTO SUNDAY. STRONGEST UPPER LEVEL JET WILL STAY IN THE NORTHERN PLAINS ALONG WITH STRONGEST POSITIVE VORTICITY VALUES...HOWEVER SOME POCKETS OF POSITIVE VORTICITY WILL ENTER THE TRI STATE AREA FOR SUNDAY AFTERNOON AND EVENING. THE TROUGH BECOMES NEGATIVELY TILTED AS FLOW PATTERN RETURNS TO ZONAL FLOW FOR SUNDAY EVENING AND MONDAY. THE RIDGE TO THE SOUTH WILL CONTINUE TO STRENGTHEN AND MOVE INTO THE CENTRAL PLAINS FOR TUESDAY...AND JET STREAM WILL STAY WELL TO THE NORTH OF THE AREA FOR THE REST OF NEXT WEEK. 850 MB JET SPEEDS ARE VERY STRONG DUE TO NOCTURNAL EFFECT FOR OVERNIGHT SATURDAY AND SUNDAY TOWARD WEST CENTRAL KANSAS...WHICH COULD PROVIDE SOME UNSTABLE WEATHER WITH UPPER LEVEL SHORTWAVE FORCING. ONCE RIDGE BUILDS INTO THE REGION...THE JET SPEEDS WILL DECREASE AND BECOME CALM FOR THE REST OF NEXT WEEK. AT THE SURFACE...STRONG WARM AIR ADVECTION WILL BE PRESENT ACROSS THE AREA WITH TEMPERATURES REACHING THE MID TO UPPER 90S FOR THE WEEKEND. 850 MB TEMPERATURES ARE ALSO WARM...WITH VALUES IN THE MID 80S SATURDAY AND SUNDAY. THETA E VALUES ARE MARGINAL AT 850 AND AT THE SURFACE...WITH HIGHER VALUES TOWARD CENTRAL KANSAS. DEW POINTS WILL BE IN THE MID 50S ACROSS THE REGION...WITH A 30 DEGREE DRY LINE GRADIENT PRESENT IN THE WESTERN CWA. ALTHOUGH BEST SURFACE BOUNDARY EXISTS FOR THE AREA SATURDAY AND SUNDAY...INSTABILITY PARAMETERS ARE MARGINAL AT BEST. THERE ARE SOME CHANCES FOR THUNDERSTORM DEVELOPMENT SATURDAY AND SUNDAY AFTERNOON...BUT THE BEST CHANCE IS TO THE EAST TOWARDS MORE UNSTABLE ENVIRONMENT IN CENTRAL KANSAS. STRONG SOUTH/SOUTHWEST FLOW WILL RETURN TO THE REGION FOR MONDAY AFTERNOON AND FOR THE REST OF THE WEEK...BRINGING WARM AIR AND DRY CONDITIONS TO MUCH OF THE AREA. AFTERNOON AND EVENING THUNDERSTORMS WILL DEVELOP ACROSS MUCH OF THE AREA FOR THE WEEKEND AS WARM FRONT INCREASES TEMPERATURES. MORE STABLE UPPER LEVEL AIR WILL MOVE INTO THE HIGH PLAINS REGION FOR NEXT WEEK...PROVIDING DRY CONDITIONS AND TEMPERATURES THAT MAY REACH NEAR 100. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1131 AM MDT WED JUN 19 2013 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD AT BOTH GLD AND MCK. CLOUDS HAVE DEVELOPED AT BOTH SITES AND ARE EXPECTED TO PERSIST THROUGH THE LATE AFTERNOON. WINDS WILL BE THE PRIMARY AVIATION CONCERN DURING THIS TAF PERIOD...WITH BREEZE SOUTHERLY WINDS OF 20KTS GUSTING TO AROUND 30KTS...KEEPING UP THROUGH THE EVENING AS A 40-50KT LOW LEVEL JET DEVELOPS OUT OF THE SOUTH-SOUTHWEST...WHICH MAY PROMPT A LLWS GROUP TO BE ADDED TO THE TAF. SOME THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON...BUT CHANCES ARE FAIRLY LOW SO DID NOT INCLUDE ANY MENTION IN TAF. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...MK AVIATION...JJM
AREA FORECAST DISCUSSION
NWS WICHITA KS
634 AM CDT WED JUN 19 2013 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM CDT WED JUN 19 2013 TOUGH FORECAST WAS MADE EVEN MORE DIFFICULT DUE TO THE UNAVAILABILITY OF HRRR/00 UTC ECMWF AND RUC AFTER 0600 UTC DUE TO PROBLEMS UPSTREAM. NONE OF THE REMAINDER OF AVAILABLE GUIDANCE HAD MUCH OF A HANDLE ON ONGOING CONVECTION. NAM WAS PARTICULARLY SUSPECT...ESPECIALLY WITH INITIALIZATION OF 850MB MOISTURE. BASED ON 0000 UTC RADIOSONDE OBSERVATION AND OBSERVATIONAL DATASETS... SEE LITTLE REASON WHY HIGH PLAINS CONVECTION WILL NOT CONTINUE TO ROLL EAST DURING THE DAY AIDED BY WARM AIR ADVECTION...INFLUX OF MOISTURE AND SHORTWAVE. EFFECTS ON TEMPERATURES/WINDS DURING THE DAY WILL BE DIFFICULT TO PIN DOWN. THINKING THAT PRECIPITATION WILL TRANSITION TO EASTERN HALF BY LATE AFTERNOON...WITH LULL IN THE WESTERN HALF AROUND SUNSET. SEE NO REASON WHY STORMS WILL NOT DEVELOP OVER THE HIGH PLAINS AGAIN TONIGHT AND ROLL EAST. THU REMAINS PROBLEMATIC...AS IT IS UNCLEAR HOW WIDESPREAD CONVECTION WILL BE OR LOW LONG IT WILL LINGER. LARGE POTENTIAL FOR ERROR ON ALL FACETS OF THIS FORECAST. HAVE LEANED A BIT TOWARDS THE GFS WHICH WAS THE LEAST WRONG GUIDANCE OUT OF THE BOX. HAVE STAYED THE COURSE WITH DRY/WARMER/WINDIER CONDITIONS ON FRIDAY. -HOWERTON .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 330 AM CDT WED JUN 19 2013 THE WARMING TREND WILL CONTINUE INTO THE WEEKEND AS RIDGE BUILDS. SOME HINT ON THE LATEST AVAILABLE GUIDANCE THAT FRONT MAY SAG CLOSE ENOUGH TO BRING SMALL CHANCES FOR PRECIPITATION ON SUN/SUN NIGHT. NOT OVERLY OPTIMISTIC ABOUT THESE CHANCES BUT IN ABSENCE OF 0000 UTC ECMWF WILL NOT MAKE SIGNIFICANT CHANGES. HAVE HEDGED TEMPERATURES UP A BIT ABOVE INITIALIZATION GRIDS BASED ON LAST WARM PERIOD AND BEST GUIDANCE AT THESE TIME RANGES. TEMPERATURES IN TRIPLE DIGITS APPEAR PROBABLE IN CENTRAL KS BY EARLY NEXT WEEK. -HOWERTON && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 632 AM CDT WED JUN 19 2013 HIGH CLOUDS WILL FLOAT OVERHEAD THIS MORNING GIVING WAY TO MID- LEVEL CUMULUS CLOUDS IN THE AFTERNOON. MEANWHILE SOUTHERLY WINDS WILL INCREASE ACROSS THE ENTIRE REGION TODAY...AS THE PRESSURE GRADIENT TIGHTENS UP FROM DEEPENING SURFACE LOW PRESSURE OVER NORTHEAST COLORADO. THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER WESTERN KANSAS LATER TODAY AND MOVE EASTWARD INTO CENTRAL KANSAS. JAKUB && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 84 70 90 73 / 40 40 30 10 HUTCHINSON 87 69 91 72 / 40 50 20 10 NEWTON 85 68 89 72 / 40 40 30 10 ELDORADO 83 69 88 73 / 40 40 40 10 WINFIELD-KWLD 84 70 89 73 / 40 40 30 10 RUSSELL 89 68 94 71 / 50 50 10 10 GREAT BEND 89 68 93 72 / 50 50 10 10 SALINA 88 70 90 75 / 40 50 30 10 MCPHERSON 87 69 90 72 / 40 50 30 10 COFFEYVILLE 90 69 86 73 / 40 30 30 10 CHANUTE 88 68 84 72 / 40 30 30 10 IOLA 88 68 83 71 / 40 40 30 10 PARSONS-KPPF 89 69 84 72 / 40 30 30 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
531 AM MDT WED JUN 19 2013 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 402 AM MDT WED JUN 19 2013 MAIN FORECAST PROBLEM THUNDERSTORM COVERAGE/CHANCES THROUGH PERIOD WITH HOW HOT DOES IT GET THURSDAY AND FRIDAY. SATELLITE CONTINUING TO SHOW AN AMPLIFIED/BLOCKY/COMPLICATED UPPER FLOW FROM THE EASTERN PACIFIC INTO THE CENTRAL PORTION OF THE COUNTRY. UPPER LOW HAS MOVED CLOSER TO THE PACIFIC NORTHWEST WITH WEST TO SOUTHWEST FL0W ALOFT SPREADING ACROSS OUR AREA. COLD FRONT REMAINS WELL TO OUR SOUTH AND IS DRAPED UP AGAINST THE COLORADO FRONT RANGE. LARGE COMPLEX OF THUNDERSTORMS HAS PRODUCED A SIGNIFICANT COLD POOL AND HAS SENT UP MESOSCALE/CONVERGENT BOUNDARIES ACROSS DIFFERENT PORTIONS OF THE REGION. MODELS INITIALIZED FINE AT JET LEVEL. THE NAM/ECMWF LOOKED TO HAVE INITIALIZED THE WORST ON THE MID LEVELS WITH THE UKMET/CANADIAN/GFS/SREF DOING ABOUT THE SAME. NAM WAS A LITTLE WARM AT 700 MB WITH THE GFS AND UKMET BETTER. SREF AND GFS WERE DOING LITTLE BETTER THAN THE NAM AND CANADIAN ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...DUE TO THE OVERNIGHT THUNDERSTORM COMPLEX THAT WENT THROUGH...MESOSCALE BOUNDARIES/CONVERGENCE DO ABOUND. SATELLITE AND UPPER AIR ANALYSIS SHOWING A COUPLE OF WEAK SHORTWAVES TO OUR WEST PLUS A WARMER AND DRIER MID LEVEL AIR MASS/EML MOVING IN FROM THE WEST. NEAR 12Z THE LEFT FRONT QUADRANT OF SOUTHERN JET WILL BE AFFECTING THE SOUTHWEST PORTION OF THE AREA. IT STAYS NEAR THE SOUTHERN PORTION OF THE AREA THROUGH AS SLOWLY PROGRESSES SOUTH AWAY FROM THE AREA. VERY UNCERTAIN PRECIPITATION FORECAST FOR THE DAY...ESPECIALLY THIS MORNING...WITH MESOSCALE FEATURES BEING A BIG INFLUENCE. CONVECTIVE CIRCULATION IS LOCATED OVER THE EASTERN PORTION OF THE AREA. ONE OF THOSE OUTFLOW BOUNDARIES LIES ACROSS THE NORTHEAST PORTION. ALL MODELS ESPECIALLY THE RAP REDEVELOPS A SIGNIFICANT PRECIPITATION AREA OVER THE NORTHEAST TO EAST PORTION OF THE AREA THIS MORNING. CONSIDERING THAT THE RAP HAS BEEN CONSISTENT FOR A COUPLE OF RUNS... MATCHES UP WITH WHERE THE BOUNDARY IS RIGHT NOW AND THAT THUNDERSTORMS HAVE REDEVELOPED ALREADY IN THE SAME GENERAL AREA... WILL RAISE POPS TO A HIGH CHANCE THIS MORNING AND CONTINUE TO MONITOR. THAT CIRCULATION AND PRECIPITATION LOOK TO EXIT THE AREA AROUND THE MIDDLE OF THE DAY. THE AIR MASS LOOKS TO RELOAD WITH EMPHASIS SHIFTING BACK TO THE WEST. SURFACE TROUGH STILL REMAINS TO THE WEST OF THE AREA. WHAT LOOKS TO BE A DRYLINE SETS UP OVER THE FAR WEST WITH THE INSTABILITY AXIS SETTING NEAR THE COLORADO AND KANSAS BORDER. THE FAR WESTERN MAY BE CAPPED THIS AFTERNOON. SHORTWAVE TROUGH MOVES IN FROM THE WEST AND EXPECT THUNDERSTORMS TO DEVELOP NEAR OR JUST TO THE EAST OF THE COLORADO BORDER. THESE STORMS SHOULD PROGRESS TO THE EAST THROUGH THE NIGHT AS THE SHORTWAVE MOVES TOWARD THE EAST AND THE LOW LEVEL JET DEVELOPS IN THE EASTERN THIRD. DO NOT HAVE A GOOD FEEL WITH THE HIGH TEMPERATURES. IT IS POSSIBLE WITH THE WET GROUND AND ONGOING CLOUD COVER AND PRECIPITATION COULD CAUSE TEMPERATURES TO BE COOLER...ESPECIALLY IN THE EAST. THURSDAY/THURSDAY NIGHT...INTERESTING FORECAST FOR THIS DAY. 700 MB TEMPERATURES REMAIN RATHER HIGH THROUGH THE DAY...WITH THE LOWEST AND CAP BREAKABLE TEMPERATURES IN THE NORTHERN AND EASTERN PORTIONS OF THE AREA. BY LATE AFTERNOON...EITHER A WEAK COOL FRONT OR SURFACE TROUGH SAGS INTO THE NORTHERN PORTION OF THE AREA WITH WHAT LOOKS TO BE A DRYLINE JUST TO THE WEST OF THE SOUTHEAST CORNER. AT THE SAME TIME A SHORTWAVE TROUGH APPROACHES FROM THE SOUTHWEST. ALL THESE FEATURES PROGRESS NORTH AND EAST THROUGH THE EVENING. BY LATE IN THE AFTERNOON A WEAK LEFT FRONT QUADRANT LOOKS TO BE JUST SOUTH OF THE FORECAST AREA. THIS LIFT MOVES SLOWLY NORTH THROUGH THE EVENING AND WILL BE AFFECT THE SOUTHEAST QUARTER BY LATE IN THE NIGHT. MODELS ARE GENERATING SOME LIGHT QPF EVEN WITH WHAT LOOKS TO BE A DEEP DRY LAYER AND HIGH BASES. BELIEVE THERE IS ENOUGH HERE TO INCLUDE A LOW SLIGHT CHANCE. HOWEVER...COULD SEE THINGS TOTALLY CAPPED OR BE ABLE TO BREAK LOOSE. ALONG AND NORTH OF THE BOUNDARY THE TEMPERATURES WILL BE SLIGHTLY COOLER...IN THE 90S. SOUTH THE BOUNDARY IT WILL BE NEAR 100 DEGREES. MODELS DO DISAGREE WITH HOW FAR SOUTH TO TAKE THE BOUNDARY. CONSIDERING THE FLOW ALOFT AND THE AIR MASS LIKE THE BOUNDARY BEING FURTHER NORTH. FRIDAY/FRIDAY NIGHT...THE CANADIAN AND ECMWF KEEP A WEAK LEFT FRONT QUADRANT OF THE JET NEAR/OVER THE EASTERN AND CENTRAL PORTION OF THE AREA THROUGH THE DAY. VERY SIMILAR SETUP TO THE DAY BEFORE EXCEPT MOST OF THE WEST AND CENTRAL PORTIONS DO LOOK CAPPED DESPITE THE SURFACE TROUGH AND DRYLINE NEAR THE SAME PLACE. THE EASTERN THIRD HAS THE LOWER 700 MB TEMPERATURES WITH THE INSTABILITY AXIS AND BEST MID LEVEL MOISTURE IN THE SAME AREA. AT THE SAME TIME A SHORTWAVE TROUGH IS COMING ACROSS. LIKED WHAT THE PREVIOUS SHIFT HAD IN THERE FOR A SLIGHT CHANCE AND ONLY MADE A SLIGHT ADJUSTMENT TO THE AREA FOR THE AFTERNOON AND EVENING HOURS. ONCE AGAIN HIGH TEMPERATURES WILL BE DETERMINED BY WHERE THE BOUNDARY SETS UP. MODEL DATA SAYS THE BOUNDARY WILL BE A LITTLE FURTHER NORTH AND SO WILL THE HOT TEMPERATURES AND TRENDED THE MAXES IN THAT DIRECTION. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 230 AM MDT TUE JUN 19 2013 STRONG SOUTHWEST FLOW ALOFT AT 500 MB WILL PERSIST THROUGHOUT THE DAY SATURDAY AS MERIDIONAL FLOW PATTERN EXISTS OVER THE CENTRAL PLAINS. INSTABILITY WILL BE PRESENT IN THE FLOW AS EMBEDDED SHORTWAVE TROUGHS ENTER INTO OUR FORECAST AREA. AN UPPER LEVEL LOW WILL PROGRESS WESTWARD OVER THE NORTHERN HIGH PLAINS AS BLOCKING RIDGE OVER THE SOUTHERN PLAINS STRENGTHENS SATURDAY EVENING INTO SUNDAY. STRONGEST UPPER LEVEL JET WILL STAY IN THE NORTHERN PLAINS ALONG WITH STRONGEST POSITIVE VORTICITY VALUES...HOWEVER SOME POCKETS OF POSITIVE VORTICITY WILL ENTER THE TRI STATE AREA FOR SUNDAY AFTERNOON AND EVENING. THE TROUGH BECOMES NEGATIVELY TILTED AS FLOW PATTERN RETURNS TO ZONAL FLOW FOR SUNDAY EVENING AND MONDAY. THE RIDGE TO THE SOUTH WILL CONTINUE TO STRENGTHEN AND MOVE INTO THE CENTRAL PLAINS FOR TUESDAY...AND JET STREAM WILL STAY WELL TO THE NORTH OF THE AREA FOR THE REST OF NEXT WEEK. 850 MB JET SPEEDS ARE VERY STRONG DUE TO NOCTURNAL EFFECT FOR OVERNIGHT SATURDAY AND SUNDAY TOWARD WEST CENTRAL KANSAS...WHICH COULD PROVIDE SOME UNSTABLE WEATHER WITH UPPER LEVEL SHORTWAVE FORCING. ONCE RIDGE BUILDS INTO THE REGION...THE JET SPEEDS WILL DECREASE AND BECOME CALM FOR THE REST OF NEXT WEEK. AT THE SURFACE...STRONG WARM AIR ADVECTION WILL BE PRESENT ACROSS THE AREA WITH TEMPERATURES REACHING THE MID TO UPPER 90S FOR THE WEEKEND. 850 MB TEMPERATURES ARE ALSO WARM...WITH VALUES IN THE MID 80S SATURDAY AND SUNDAY. THETA E VALUES ARE MARGINAL AT 850 AND AT THE SURFACE...WITH HIGHER VALUES TOWARD CENTRAL KANSAS. DEW POINTS WILL BE IN THE MID 50S ACROSS THE REGION...WITH A 30 DEGREE DRY LINE GRADIENT PRESENT IN THE WESTERN CWA. ALTHOUGH BEST SURFACE BOUNDARY EXISTS FOR THE AREA SATURDAY AND SUNDAY...INSTABILITY PARAMETERS ARE MARGINAL AT BEST. THERE ARE SOME CHANCES FOR THUNDERSTORM DEVELOPMENT SATURDAY AND SUNDAY AFTERNOON...BUT THE BEST CHANCE IS TO THE EAST TOWARDS MORE UNSTABLE ENVIRONMENT IN CENTRAL KANSAS. STRONG SOUTH/SOUTHWEST FLOW WILL RETURN TO THE REGION FOR MONDAY AFTERNOON AND FOR THE REST OF THE WEEK...BRINGING WARM AIR AND DRY CONDITIONS TO MUCH OF THE AREA. AFTERNOON AND EVENING THUNDERSTORMS WILL DEVELOP ACROSS MUCH OF THE AREA FOR THE WEEKEND AS WARM FRONT INCREASES TEMPERATURES. MORE STABLE UPPER LEVEL AIR WILL MOVE INTO THE HIGH PLAINS REGION FOR NEXT WEEK...PROVIDING DRY CONDITIONS AND TEMPERATURES THAT MAY REACH NEAR 100. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 529 AM MDT WED JUN 19 2013 LOW PRESSURE SYSTEM TO THE WEST OF THE TAF SITES WILL HELP PRODUCE AFTERNOON AND EVENING THUNDERSTORMS AT KGLD AND KMCK. CONFIDENCE IS LOW AT THIS POINT AS TO LOCATION OF FORMATION...AS BEST CHANCES LOOK TO BE WEST OF THE TAF SITES IN THE COLORADO COUNTIES. THEREFORE...NO MENTION OF THUNDERSTORMS IN THE TAFS AT THIS TIME. LINGERING SHOWERS NEAR KMCK WILL DIMINISH AFTER 15Z. WINDS WILL BE BREEZY AT BOTH SITES TODAY...GUSTING TO 30 KTS AT TIMES. BOTH VISIBILITIES AND CEILING HEIGHTS FOR THE TERMINALS ARE EXPECTED TO BE VFR THROUGHOUT THE TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...MK AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
402 AM MDT WED JUN 19 2013 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 402 AM MDT WED JUN 19 2013 MAIN FORECAST PROBLEM THUNDERSTORM COVERAGE/CHANCES THROUGH PERIOD WITH HOW HOT DOES IT GET THURSDAY AND FRIDAY. SATELLITE CONTINUING TO SHOW AN AMPLIFIED/BLOCKY/COMPLICATED UPPER FLOW FROM THE EASTERN PACIFIC INTO THE CENTRAL PORTION OF THE COUNTRY. UPPER LOW HAS MOVED CLOSER TO THE PACIFIC NORTHWEST WITH WEST TO SOUTHWEST FL0W ALOFT SPREADING ACROSS OUR AREA. COLD FRONT REMAINS WELL TO OUR SOUTH AND IS DRAPED UP AGAINST THE COLORADO FRONT RANGE. LARGE COMPLEX OF THUNDERSTORMS HAS PRODUCED A SIGNIFICANT COLD POOL AND HAS SENT UP MESOSCALE/CONVERGENT BOUNDARIES ACROSS DIFFERENT PORTIONS OF THE REGION. MODELS INITIALIZED FINE AT JET LEVEL. THE NAM/ECMWF LOOKED TO HAVE INITIALIZED THE WORST ON THE MID LEVELS WITH THE UKMET/CANADIAN/GFS/SREF DOING ABOUT THE SAME. NAM WAS A LITTLE WARM AT 700 MB WITH THE GFS AND UKMET BETTER. SREF AND GFS WERE DOING LITTLE BETTER THAN THE NAM AND CANADIAN ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...DUE TO THE OVERNIGHT THUNDERSTORM COMPLEX THAT WENT THROUGH...MESOSCALE BOUNDARIES/CONVERGENCE DO ABOUND. SATELLITE AND UPPER AIR ANALYSIS SHOWING A COUPLE OF WEAK SHORTWAVES TO OUR WEST PLUS A WARMER AND DRIER MID LEVEL AIR MASS/EML MOVING IN FROM THE WEST. NEAR 12Z THE LEFT FRONT QUADRANT OF SOUTHERN JET WILL BE AFFECTING THE SOUTHWEST PORTION OF THE AREA. IT STAYS NEAR THE SOUTHERN PORTION OF THE AREA THROUGH AS SLOWLY PROGRESSES SOUTH AWAY FROM THE AREA. VERY UNCERTAIN PRECIPITATION FORECAST FOR THE DAY...ESPECIALLY THIS MORNING...WITH MESOSCALE FEATURES BEING A BIG INFLUENCE. CONVECTIVE CIRCULATION IS LOCATED OVER THE EASTERN PORTION OF THE AREA. ONE OF THOSE OUTFLOW BOUNDARIES LIES ACROSS THE NORTHEAST PORTION. ALL MODELS ESPECIALLY THE RAP REDEVELOPS A SIGNIFICANT PRECIPITATION AREA OVER THE NORTHEAST TO EAST PORTION OF THE AREA THIS MORNING. CONSIDERING THAT THE RAP HAS BEEN CONSISTENT FOR A COUPLE OF RUNS... MATCHES UP WITH WHERE THE BOUNDARY IS RIGHT NOW AND THAT THUNDERSTORMS HAVE REDEVELOPED ALREADY IN THE SAME GENERAL AREA... WILL RAISE POPS TO A HIGH CHANCE THIS MORNING AND CONTINUE TO MONITOR. THAT CIRCULATION AND PRECIPITATION LOOK TO EXIT THE AREA AROUND THE MIDDLE OF THE DAY. THE AIR MASS LOOKS TO RELOAD WITH EMPHASIS SHIFTING BACK TO THE WEST. SURFACE TROUGH STILL REMAINS TO THE WEST OF THE AREA. WHAT LOOKS TO BE A DRYLINE SETS UP OVER THE FAR WEST WITH THE INSTABILITY AXIS SETTING NEAR THE COLORADO AND KANSAS BORDER. THE FAR WESTERN MAY BE CAPPED THIS AFTERNOON. SHORTWAVE TROUGH MOVES IN FROM THE WEST AND EXPECT THUNDERSTORMS TO DEVELOP NEAR OR JUST TO THE EAST OF THE COLORADO BORDER. THESE STORMS SHOULD PROGRESS TO THE EAST THROUGH THE NIGHT AS THE SHORTWAVE MOVES TOWARD THE EAST AND THE LOW LEVEL JET DEVELOPS IN THE EASTERN THIRD. DO NOT HAVE A GOOD FEEL WITH THE HIGH TEMPERATURES. IT IS POSSIBLE WITH THE WET GROUND AND ONGOING CLOUD COVER AND PRECIPITATION COULD CAUSE TEMPERATURES TO BE COOLER...ESPECIALLY IN THE EAST. THURSDAY/THURSDAY NIGHT...INTERESTING FORECAST FOR THIS DAY. 700 MB TEMPERATURES REMAIN RATHER HIGH THROUGH THE DAY...WITH THE LOWEST AND CAP BREAKABLE TEMPERATURES IN THE NORTHERN AND EASTERN PORTIONS OF THE AREA. BY LATE AFTERNOON...EITHER A WEAK COOL FRONT OR SURFACE TROUGH SAGS INTO THE NORTHERN PORTION OF THE AREA WITH WHAT LOOKS TO BE A DRYLINE JUST TO THE WEST OF THE SOUTHEAST CORNER. AT THE SAME TIME A SHORTWAVE TROUGH APPROACHES FROM THE SOUTHWEST. ALL THESE FEATURES PROGRESS NORTH AND EAST THROUGH THE EVENING. BY LATE IN THE AFTERNOON A WEAK LEFT FRONT QUADRANT LOOKS TO BE JUST SOUTH OF THE FORECAST AREA. THIS LIFT MOVES SLOWLY NORTH THROUGH THE EVENING AND WILL BE AFFECT THE SOUTHEAST QUARTER BY LATE IN THE NIGHT. MODELS ARE GENERATING SOME LIGHT QPF EVEN WITH WHAT LOOKS TO BE A DEEP DRY LAYER AND HIGH BASES. BELIEVE THERE IS ENOUGH HERE TO INCLUDE A LOW SLIGHT CHANCE. HOWEVER...COULD SEE THINGS TOTALLY CAPPED OR BE ABLE TO BREAK LOOSE. ALONG AND NORTH OF THE BOUNDARY THE TEMPERATURES WILL BE SLIGHTLY COOLER...IN THE 90S. SOUTH THE BOUNDARY IT WILL BE NEAR 100 DEGREES. MODELS DO DISAGREE WITH HOW FAR SOUTH TO TAKE THE BOUNDARY. CONSIDERING THE FLOW ALOFT AND THE AIR MASS LIKE THE BOUNDARY BEING FURTHER NORTH. FRIDAY/FRIDAY NIGHT...THE CANADIAN AND ECMWF KEEP A WEAK LEFT FRONT QUADRANT OF THE JET NEAR/OVER THE EASTERN AND CENTRAL PORTION OF THE AREA THROUGH THE DAY. VERY SIMILAR SETUP TO THE DAY BEFORE EXCEPT MOST OF THE WEST AND CENTRAL PORTIONS DO LOOK CAPPED DESPITE THE SURFACE TROUGH AND DRYLINE NEAR THE SAME PLACE. THE EASTERN THIRD HAS THE LOWER 700 MB TEMPERATURES WITH THE INSTABILITY AXIS AND BEST MID LEVEL MOISTURE IN THE SAME AREA. AT THE SAME TIME A SHORTWAVE TROUGH IS COMING ACROSS. LIKED WHAT THE PREVIOUS SHIFT HAD IN THERE FOR A SLIGHT CHANCE AND ONLY MADE A SLIGHT ADJUSTMENT TO THE AREA FOR THE AFTERNOON AND EVENING HOURS. ONCE AGAIN HIGH TEMPERATURES WILL BE DETERMINED BY WHERE THE BOUNDARY SETS UP. MODEL DATA SAYS THE BOUNDARY WILL BE A LITTLE FURTHER NORTH AND SO WILL THE HOT TEMPERATURES AND TRENDED THE MAXES IN THAT DIRECTION. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 230 AM MDT TUE JUN 19 2013 STRONG SOUTHWEST FLOW ALOFT AT 500 MB WILL PERSIST THROUGHOUT THE DAY SATURDAY AS MERIDIONAL FLOW PATTERN EXISTS OVER THE CENTRAL PLAINS. INSTABILITY WILL BE PRESENT IN THE FLOW AS EMBEDDED SHORTWAVE TROUGHS ENTER INTO OUR FORECAST AREA. AN UPPER LEVEL LOW WILL PROGRESS WESTWARD OVER THE NORTHERN HIGH PLAINS AS BLOCKING RIDGE OVER THE SOUTHERN PLAINS STRENGTHENS SATURDAY EVENING INTO SUNDAY. STRONGEST UPPER LEVEL JET WILL STAY IN THE NORTHERN PLAINS ALONG WITH STRONGEST POSITIVE VORTICITY VALUES...HOWEVER SOME POCKETS OF POSITIVE VORTICITY WILL ENTER THE TRI STATE AREA FOR SUNDAY AFTERNOON AND EVENING. THE TROUGH BECOMES NEGATIVELY TILTED AS FLOW PATTERN RETURNS TO ZONAL FLOW FOR SUNDAY EVENING AND MONDAY. THE RIDGE TO THE SOUTH WILL CONTINUE TO STRENGTHEN AND MOVE INTO THE CENTRAL PLAINS FOR TUESDAY...AND JET STREAM WILL STAY WELL TO THE NORTH OF THE AREA FOR THE REST OF NEXT WEEK. 850 MB JET SPEEDS ARE VERY STRONG DUE TO NOCTURNAL EFFECT FOR OVERNIGHT SATURDAY AND SUNDAY TOWARD WEST CENTRAL KANSAS...WHICH COULD PROVIDE SOME UNSTABLE WEATHER WITH UPPER LEVEL SHORTWAVE FORCING. ONCE RIDGE BUILDS INTO THE REGION...THE JET SPEEDS WILL DECREASE AND BECOME CALM FOR THE REST OF NEXT WEEK. AT THE SURFACE...STRONG WARM AIR ADVECTION WILL BE PRESENT ACROSS THE AREA WITH TEMPERATURES REACHING THE MID TO UPPER 90S FOR THE WEEKEND. 850 MB TEMPERATURES ARE ALSO WARM...WITH VALUES IN THE MID 80S SATURDAY AND SUNDAY. THETA E VALUES ARE MARGINAL AT 850 AND AT THE SURFACE...WITH HIGHER VALUES TOWARD CENTRAL KANSAS. DEW POINTS WILL BE IN THE MID 50S ACROSS THE REGION...WITH A 30 DEGREE DRY LINE GRADIENT PRESENT IN THE WESTERN CWA. ALTHOUGH BEST SURFACE BOUNDARY EXISTS FOR THE AREA SATURDAY AND SUNDAY...INSTABILITY PARAMETERS ARE MARGINAL AT BEST. THERE ARE SOME CHANCES FOR THUNDERSTORM DEVELOPMENT SATURDAY AND SUNDAY AFTERNOON...BUT THE BEST CHANCE IS TO THE EAST TOWARDS MORE UNSTABLE ENVIRONMENT IN CENTRAL KANSAS. STRONG SOUTH/SOUTHWEST FLOW WILL RETURN TO THE REGION FOR MONDAY AFTERNOON AND FOR THE REST OF THE WEEK...BRINGING WARM AIR AND DRY CONDITIONS TO MUCH OF THE AREA. AFTERNOON AND EVENING THUNDERSTORMS WILL DEVELOP ACROSS MUCH OF THE AREA FOR THE WEEKEND AS WARM FRONT INCREASES TEMPERATURES. MORE STABLE UPPER LEVEL AIR WILL MOVE INTO THE HIGH PLAINS REGION FOR NEXT WEEK...PROVIDING DRY CONDITIONS AND TEMPERATURES THAT MAY REACH NEAR 100. && .AVIATION....(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1131 PM MDT TUE JUN 18 2013 MVFR TO VFR CONDITIONS FORECAST FOR THE 6Z TAFS. RATHER COMPLICATED WEATHER PATTERN OVERNIGHT DUE TO VARIOUS OUTFLOW BOUNDARIES ALONG WITH LINGERING ELEVATED INSTABILITY. MESOSCALE STORM COMPLEX SHOULD BE EAST OF KGLD BY THE START OF THE TAFS...WITH ISOLATED TO SCATTERED STORM COVERAGE BEHIND THE COMPLEX INTO THE OVERNIGHT HOURS. THE STORM ACTIVITY SHOULD REMAIN SOUTH AND EAST OF KMCK...ALTHOUGH A FEW STORMS MAY NEAR THE SITE. DUE TO THE RAINFALL AND THE SOUTHEAST WINDS BRINGING IN HIGHER DEW POINTS AROUND KGLD TONIGHT...FOG MAY DEVELOP. MOST MODELS ARE NOT INDICATING FOG FORMING ALTHOUGH CLIMATOLOGY IS INDICATING REDUCTIONS ARE POSSIBLE. AS SUCH WILL INCLUDE A MINOR VISIBILITY REDUCTION FOR KGLD OVERNIGHT. MODELS ARE PLACING LIFT OVER KMCK DURING THE MORNING...WITH THE LIFT MOVING EAST FAIRLY QUICKLY. AT THIS TIME WILL NOT INCLUDE A VICINITY TS IN THE TAF DUE TO LOW CONFIDENCE STORMS WILL DEVELOP NEAR THE SITE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...MK AVIATION...JTL
AREA FORECAST DISCUSSION
NWS WICHITA KS
337 AM CDT WED JUN 19 2013 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM CDT WED JUN 19 2013 TOUGH FORECAST WAS MADE EVEN MORE DIFFICULT DUE TO THE UNAVAILABILITY OF HRRR/00 UTC ECMWF AND RUC AFTER 0600 UTC DUE TO PROBLEMS UPSTREAM. NONE OF THE REMAINDER OF AVAILABLE GUIDANCE HAD MUCH OF A HANDLE ON ONGOING CONVECTION. NAM WAS PARTICULARLY SUSPECT...ESPECIALLY WITH INITIALIZATION OF 850MB MOISTURE. BASED ON 0000 UTC RADIOSONDE OBSERVATION AND OBSERVATIONAL DATASETS... SEE LITTLE REASON WHY HIGH PLAINS CONVECTION WILL NOT CONTINUE TO ROLL EAST DURING THE DAY AIDED BY WARM AIR ADVECTION...INFLUX OF MOISTURE AND SHORTWAVE. EFFECTS ON TEMPERATURES/WINDS DURING THE DAY WILL BE DIFFICULT TO PIN DOWN. THINKING THAT PRECIPITATION WILL TRANSITION TO EASTERN HALF BY LATE AFTERNOON...WITH LULL IN THE WESTERN HALF AROUND SUNSET. SEE NO REASON WHY STORMS WILL NOT DEVELOP OVER THE HIGH PLAINS AGAIN TONIGHT AND ROLL EAST. THU REMAINS PROBLEMATIC...AS IT IS UNCLEAR HOW WIDESPREAD CONVECTION WILL BE OR LOW LONG IT WILL LINGER. LARGE POTENTIAL FOR ERROR ON ALL FACETS OF THIS FORECAST. HAVE LEANED A BIT TOWARDS THE GFS WHICH WAS THE LEAST WRONG GUIDANCE OUT OF THE BOX. HAVE STAYED THE COURSE WITH DRY/WARMER/WINDIER CONDITIONS ON FRIDAY. -HOWERTON .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 330 AM CDT WED JUN 19 2013 THE WARMING TREND WILL CONTINUE INTO THE WEEKEND AS RIDGE BUILDS. SOME HINT ON THE LATEST AVAILABLE GUIDANCE THAT FRONT MAY SAG CLOSE ENOUGH TO BRING SMALL CHANCES FOR PRECIPITATION ON SUN/SUN NIGHT. NOT OVERLY OPTIMISTIC ABOUT THESE CHANCES BUT IN ABSENCE OF 0000 UTC ECMWF WILL NOT MAKE SIGNIFICANT CHANGES. HAVE HEDGED TEMPERATURES UP A BIT ABOVE INITIALIZATION GRIDS BASED ON LAST WARM PERIOD AND BEST GUIDANCE AT THESE TIME RANGES. TEMPERATURES IN TRIPLE DIGITS APPEAR PROBABLE IN CENTRAL KS BY EARLY NEXT WEEK. -HOWERTON && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1247 AM CDT WED JUN 19 2013 TSRA CLUSTER CONTINUING TO MOVE SE~20KTS OVER SC KS SHOULD PASS PRIMARILY ALONG & W OF I-135 THRU ~07Z. NO CIG & VSBY RESTRICTIONS HAVE BEEN ASSOCIATED WITH THE (+)TSRA & HAVE THEREFORE KEPT KICT IN VFR STATUS BUT WINDS ASSOCIATED WITH THE TSRA HAVE BEEN VARIABLE IN BOTH SPEEDS & DIRECTIONS SO HAVE ALREADY UPDATED KICT TO ADDRESS THIS ISSUE. INSOLATION COMBINES WITH DAMP GROUNDS TO ENABLE CUMULUS TO REDEVELOP OVER ALL 5 TERMINALS ~18Z. PERSISTENT LWR-DECK TROF AXIS THAT IS CLOSELY ALIGNED WITH CO/KS BORDER SHOULD ENABLE WINDS TO BECOME DUE SLY & INCREASE TO ~20KTS SUSTAINED WITH GUSTS ~30KTS OVER MOST AREAS ~18Z. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 84 70 90 73 / 40 40 30 10 HUTCHINSON 87 69 91 72 / 40 50 20 10 NEWTON 85 68 89 72 / 40 40 30 10 ELDORADO 83 69 88 73 / 40 40 40 10 WINFIELD-KWLD 84 70 89 73 / 40 40 30 10 RUSSELL 89 68 94 71 / 50 50 10 10 GREAT BEND 89 68 93 72 / 50 50 10 10 SALINA 88 70 90 75 / 40 50 30 10 MCPHERSON 87 69 90 72 / 40 50 30 10 COFFEYVILLE 90 69 86 73 / 40 30 30 10 CHANUTE 88 68 84 72 / 40 30 30 10 IOLA 88 68 83 71 / 40 40 30 10 PARSONS-KPPF 89 69 84 72 / 40 30 30 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
941 PM EDT THU JUN 20 2013 .UPDATE... ISSUED AT 941 PM EDT THU JUN 20 2013 VERY FEW CHANGES NEEDED TO THE FORECAST TONIGHT. STORMS BACK- BUILDING INTO WISE COUNTY VA MAY SNEAK BACK INTO HARLAN AND LETCHER COUNTIES OVER THE NEXT HOUR OR TWO SO WILL MAINTAIN A SMALL CHANCE OF A STORM THERE FOR A FEW MORE HOURS WITH DRY CONDITIONS ANTICIPATED FOR THE REST OF THE AREA TONIGHT. FORECAST LOWS A COUPLE DEGREES WARMER THAN LAST NIGHT APPEAR ON TARGET SO NO CHANGES THERE. HAVE A GOOD NIGHT... && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 323 PM EDT THU JUN 20 2013 AS OF MID AFTERNOON...A RIDGE OF HIGH PRESSURE WAS CENTERED OVER NORTHERN MEXICO AND THE SOUTHERN PLAINS WITH RIDGING EXTENDING NORTH THROUGH THE PLAINS AND GENERAL RIDGING SOUTHEAST INTO THE GULF OF MEXICO. MEANWHILE...A SHORTWAVE IS WORKING THROUGH THE OH VALLEY WITH WEAK TROUGHING IN PLACE OVER THE LOWER OH VALLEY AND TN VALLEY REGION INTO THE SOUTHEAST. AF THE SFC...HIGH PRESSURE WAS CENTERED OVER THE NORTHEASTERN CONUS WITH RIDGING SOUTHWEST INTO THE OH VALLEY. CONVECTION SO FAR HAS GENERALLY BEEN CONFINED TO THE NORTHERN CUMBERLAND PLATEAU OF TN INTO THE LAKE CUMBERLAND REGION. FOR THE REMAINDER OF THIS AFTERNOON AND INTO THIS EVENING... CONVECTION SHOULD CONTINUE TO DEVELOP ALONG THE TN AND VA BORDERS AS THE SHORTWAVE WORKS ACROSS THE OH VALLEY. CONVECTION SHOULD WANE THROUGH THE EVENING WITH LOSS OF DAYTIME HEATING WITH CU DISSIPATING DURING THAT TIME AS WELL. AREAS OF VALLEY FOG SHOULD DEVELOP TONIGHT WITH DEWPOINTS AROUND 60 OR IN THE LOWER 60S AND A RELATIVELY WEAK PRESSURE GRADIENT IN PLACE. SOME OF THIS WILL ALMOST CERTAINLY BECOME DENSE IN THE RIVER VALLEYS...ESPECIALLY IN THE BIG SANDY REGION. POPS FOR THE REMAINDER OF THE AFTERNOON INTO THE EVENING WERE RELATIVELY UNCHANGED AS RECENT TRENDS ARE GENERALLY SUPPORTIVE OF THESE WHEN CONSIDERED WITH RECENT MODEL GUIDANCE INCLUDING RECENT HRRR RUNS THAT EVENTUALLY DEVELOP CONVECTION NEAR THE VA BORDER AND THEN HAVE A COUPLE OF GENERATIONS OF IT WORKING TOWARD THE NORTHWEST OVER THE SOUTHEASTERN COUNTIES. THE REGION WILL BE IN A GENERAL WEAKNESS BETWEEN RIDGING OVER THE ATLANTIC AND OVER THE MS VALLEY REGION WHILE A WEAK UPPER LEVEL LOW IS PROGGED OVER THE SOUTHEASTERN STATES FOR FRI AND FRI NIGHT. GENERALLY DIURNALLY DRIVEN CONVECTION IS ANTICIPATED FRI AFTERNOON INTO FRI EVENING AS THERE ARE NO OTHER REAL TRIGGERS. SLIGHT CHANCE POPS WERE USED FOR ALL AREAS ALONG SOUTH OF INTERSTATE 64 WITH A LITTLE BIT OF CHANCE OVER THE HIGHEST TERRAIN ALONG THE VA BORDER. PATCHY VALLEY FOG IS AGAIN FAVORED WITH SFC HIGH PRESSURE CENTERED TO OUR EAST AND NORTHEAST WITH RELATIVELY HIGH DEWPOINTS AND A WEAK PRESSURE GRADIENT. MUCH OF THE CLOUD COVER SHOULD THIN ON FRI NIGHT WITH LOSS OF DAYTIME HEATING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 339 PM EDT THU JUN 20 2013 THE LONG TERM STARTS OUT ON SATURDAY WITH AN UPPER RIDGE DOMINATING THE SOUTHEAST COAST WITH A RESIDUAL WEAK CUTOFF UPPER LOW LOCATED NEAR THE AL-TN-GA BORDER. CONFIDENCE IN THE FORECAST IS VERY LOW BECAUSE THE MODELS REALLY DO NOT DO VERY WELL WITH THESE RESIDUAL LOWS THIS TIME OF THE YEAR. THE FORECAST POSITIONS CAN BE VASTLY DIFFERENT BASED ON THE POSITION OF THE UPPER LOW...AS IT CAN BRING WITH IT INCREASED INSTABILITY AND A GREATER CHANCE FOR PRECIPITATION. IN GENERAL...CONDITIONS WILL BE WARM WITH LOTS OF CONVECTIVE ACTIVITY. THE THUNDER SHOULD TEND TO HAVE AN AFTERNOON AND EARLY EVENING MAXIMUM...HOWEVER AN ISOLATED STORM MAY CONTINUE INTO THE OVERNIGHT HOURS. SOME OF THE STORMS MAY BECOME STRONG HOWEVER SHOULD STAY BELOW SEVERE CRITERIA. IN PLACES WHERE THUNDERSTORMS DO OCCUR...THERE COULD BE SOME LOCALIZED HIGH WATER WITH DITCHES AND LOW WATER CROSSINGS RUNNING FULL DUE TO THE VERY SLOW MOVEMENT OF THE STORMS. TEMPERATURES WILL CONTINUE TO BE VERY SEASONAL WITH HIGH TEMPERATURES STAYING IN THE MID 80S. THIS PATTERN SHOULD CONTINUE THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 722 PM EDT THU JUN 20 2013 SFC HIGH PRESSURE WILL BRING MAINLY VFR CONDITIONS AND LIGHT WINDS THROUGH THE PERIOD. A FEW STORMS MAY DEVELOP UNTIL SUNDOWN THIS EVENING...AND THEN AGAIN TOMORROW AFTERNOON. HOWEVER...THE PROBABILITY OF ONE HITTING A TAF SITE IS TOO LOW FOR A MENTION IN THE TAFS. TYPICAL SUMMERTIME VALLEY FOG WILL DEVELOP TONIGHT... BECOMING DENSE IN OUR EASTERN RIVER VALLEYS. WHILE VSBYS STAYED UP LAST NIGHT AT LOZ AND SME...I HELD ONTO THE INHERITED PERIOD OF MVFR CIGS IN THE TAFS AT THOSE LOCATIONS TONIGHT WITH DEWPOINTS UP A FEW DEGREES COMPARED TO 24 HOURS AGO. DEWPOINTS ARE LOWER AT JKL SO WILL INDICATE A VFR FORECAST THERE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ABE SHORT TERM...JP LONG TERM...JJ AVIATION...ABE
AREA FORECAST DISCUSSION
NWS JACKSON KY
722 PM EDT THU JUN 20 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 323 PM EDT THU JUN 20 2013 AS OF MID AFTERNOON...A RIDGE OF HIGH PRESSURE WAS CENTERED OVER NORTHERN MEXICO AND THE SOUTHERN PLAINS WITH RIDGING EXTENDING NORTH THROUGH THE PLAINS AND GENERAL RIDGING SOUTHEAST INTO THE GULF OF MEXICO. MEANWHILE...A SHORTWAVE IS WORKING THROUGH THE OH VALLEY WITH WEAK TROUGHING IN PLACE OVER THE LOWER OH VALLEY AND TN VALLEY REGION INTO THE SOUTHEAST. AF THE SFC...HIGH PRESSURE WAS CENTERED OVER THE NORTHEASTERN CONUS WITH RIDGING SOUTHWEST INTO THE OH VALLEY. CONVECTION SO FAR HAS GENERALLY BEEN CONFINED TO THE NORTHERN CUMBERLAND PLATEAU OF TN INTO THE LAKE CUMBERLAND REGION. FOR THE REMAINDER OF THIS AFTERNOON AND INTO THIS EVENING... CONVECTION SHOULD CONTINUE TO DEVELOP ALONG THE TN AND VA BORDERS AS THE SHORTWAVE WORKS ACROSS THE OH VALLEY. CONVECTION SHOULD WANE THROUGH THE EVENING WITH LOSS OF DAYTIME HEATING WITH CU DISSIPATING DURING THAT TIME AS WELL. AREAS OF VALLEY FOG SHOULD DEVELOP TONIGHT WITH DEWPOINTS AROUND 60 OR IN THE LOWER 60S AND A RELATIVELY WEAK PRESSURE GRADIENT IN PLACE. SOME OF THIS WILL ALMOST CERTAINLY BECOME DENSE IN THE RIVER VALLEYS...ESPECIALLY IN THE BIG SANDY REGION. POPS FOR THE REMAINDER OF THE AFTERNOON INTO THE EVENING WERE RELATIVELY UNCHANGED AS RECENT TRENDS ARE GENERALLY SUPPORTIVE OF THESE WHEN CONSIDERED WITH RECENT MODEL GUIDANCE INCLUDING RECENT HRRR RUNS THAT EVENTUALLY DEVELOP CONVECTION NEAR THE VA BORDER AND THEN HAVE A COUPLE OF GENERATIONS OF IT WORKING TOWARD THE NORTHWEST OVER THE SOUTHEASTERN COUNTIES. THE REGION WILL BE IN A GENERAL WEAKNESS BETWEEN RIDGING OVER THE ATLANTIC AND OVER THE MS VALLEY REGION WHILE A WEAK UPPER LEVEL LOW IS PROGGED OVER THE SOUTHEASTERN STATES FOR FRI AND FRI NIGHT. GENERALLY DIURNALLY DRIVEN CONVECTION IS ANTICIPATED FRI AFTERNOON INTO FRI EVENING AS THERE ARE NO OTHER REAL TRIGGERS. SLIGHT CHANCE POPS WERE USED FOR ALL AREAS ALONG SOUTH OF INTERSTATE 64 WITH A LITTLE BIT OF CHANCE OVER THE HIGHEST TERRAIN ALONG THE VA BORDER. PATCHY VALLEY FOG IS AGAIN FAVORED WITH SFC HIGH PRESSURE CENTERED TO OUR EAST AND NORTHEAST WITH RELATIVELY HIGH DEWPOINTS AND A WEAK PRESSURE GRADIENT. MUCH OF THE CLOUD COVER SHOULD THIN ON FRI NIGHT WITH LOSS OF DAYTIME HEATING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 339 PM EDT THU JUN 20 2013 THE LONG TERM STARTS OUT ON SATURDAY WITH AN UPPER RIDGE DOMINATING THE SOUTHEAST COAST WITH A RESIDUAL WEAK CUTOFF UPPER LOW LOCATED NEAR THE AL-TN-GA BORDER. CONFIDENCE IN THE FORECAST IS VERY LOW BECAUSE THE MODELS REALLY DO NOT DO VERY WELL WITH THESE RESIDUAL LOWS THIS TIME OF THE YEAR. THE FORECAST POSITIONS CAN BE VASTLY DIFFERENT BASED ON THE POSITION OF THE UPPER LOW...AS IT CAN BRING WITH IT INCREASED INSTABILITY AND A GREATER CHANCE FOR PRECIPITATION. IN GENERAL...CONDITIONS WILL BE WARM WITH LOTS OF CONVECTIVE ACTIVITY. THE THUNDER SHOULD TEND TO HAVE AN AFTERNOON AND EARLY EVENING MAXIMUM...HOWEVER AN ISOLATED STORM MAY CONTINUE INTO THE OVERNIGHT HOURS. SOME OF THE STORMS MAY BECOME STRONG HOWEVER SHOULD STAY BELOW SEVERE CRITERIA. IN PLACES WHERE THUNDERSTORMS DO OCCUR...THERE COULD BE SOME LOCALIZED HIGH WATER WITH DITCHES AND LOW WATER CROSSINGS RUNNING FULL DUE TO THE VERY SLOW MOVEMENT OF THE STORMS. TEMPERATURES WILL CONTINUE TO BE VERY SEASONAL WITH HIGH TEMPERATURES STAYING IN THE MID 80S. THIS PATTERN SHOULD CONTINUE THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 722 PM EDT THU JUN 20 2013 SFC HIGH PRESSURE WILL BRING MAINLY VFR CONDITIONS AND LIGHT WINDS THROUGH THE PERIOD. A FEW STORMS MAY DEVELOP UNTIL SUNDOWN THIS EVENING...AND THEN AGAIN TOMORROW AFTERNOON. HOWEVER...THE PROBABILITY OF ONE HITTING A TAF SITE IS TOO LOW FOR A MENTION IN THE TAFS. TYPICAL SUMMERTIME VALLEY FOG WILL DEVELOP TONIGHT... BECOMING DENSE IN OUR EASTERN RIVER VALLEYS. WHILE VSBYS STAYED UP LAST NIGHT AT LOZ AND SME...I HELD ONTO THE INHERITED PERIOD OF MVFR CIGS IN THE TAFS AT THOSE LOCATIONS TONIGHT WITH DEWPOINTS UP A FEW DEGREES COMPARED TO 24 HOURS AGO. DEWPOINTS ARE LOWER AT JKL SO WILL INDICATE A VFR FORECAST THERE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JP LONG TERM...JJ AVIATION...ABE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
803 PM EDT THU JUN 20 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 431 PM EDT THU JUN 20 2013 UPPER AIR PATTERN FEATURES DEEP TROUGHING OVER NORTHWEST CONUS WITH RIDGING DOWNSTREAM OVER NORTHERN PLAINS. SFC FRONT WITH DRIER AIR IS WORKING ACROSS DAKOTAS WITH WEAK SFC LOW OVR NCNTRL SD BTWN KBIS AND KABR. BASED ON SFC OBS AND VIS SATELLITE APPEARS WARM FRONT EXTENDS FROM SFC LOW ACROSS CNTRL MN AND INTO NORTHWEST WI. NOT MUCH OF A TEMP GRADIENT AT H85 BUT RIBBON OF HIGHER H85-H7 DWPNT ALONG WITH H85 CONVERGENCE FROM NORTHERN MN ACROSS UPR MICHIGAN IS SERVING AS FOCUS WAVE AFTER WAVE OF SCT SHRA/ISOLD TSRA. NO STRONG TSTM THOUGH AS CAPE AVAILABLE OVR THE AREA IS BLO 1000 J/KG. DEEP LAYER SHEAR IS MARGINAL AS WELL...MAYBE UP TO 30 KTS. STRONGEST CONVECTION TODAY HAVE HAD LIGHTNING BUT HAVE REALLY SHOWN LITTLE TILT OWING TO THE LIMITED INSTABILITY/SHEAR. BASED ON WV LOOP/LIGHTNING AND RUC ANALYSIS...DOES SEEM THAT THERE IS ONE WEAKER SHORTWAVE OVER NORTHWEST WI...ANOTHER NEAR THE DLH AREA...AND A STRONGER WAVE LIFTING ENE ACROSS NORTHEAST ND. EXPECT ISOLD-SCATTERED SHRA AND TSRA OVR CWA THROUGH EVENING...ESPECIALLY NORTHERN HALF...AS THESE WAVES SLIDE THROUGH ALONG THE BOUNDARY AT H85. OVERALL...LIMITED INSTABILITY SHOULD PRECLUDE STRONGER STORMS THIS EVENING OVR MUCH OF CWA. EXCEPTION MAY BE IN FAR SW VCNTY OF IWD AS MLCAPE BUILDING UP OVER 1000J/KG JUST TO SOUTHWEST OF WEST CWA AND SWRLY STORM MOTION COULD RESULT IN STRONGER STORM WITH GUSTY WINDS AND HAIL. THUS FAR NO REAL INDICATIONS OF THIS WITH UPSTREAM STORMS BUT IT IS SOMETHING TO WATCH. LATER TONIGHT...MAIN QUESTION IS WHAT WILL OCCUR WITH UPSTREAM CONVECTION. IN A NUTSHELL...APPEARS THAT IF PRIMARY AREA OF CONVECTIVE DEVELOPING THROUGH EARLY EVENING OCCURS ALONG AND EAST OF SFC LOW...850-300MB THICKNESS/ORIENTATION OF HIGHEST MUCAPE/FORWARD PROPAGATING CORFIDI VECTORS POINT TO MAIN TRACK OF SHRA/TSRA COMPLEX OR BONIFIDE MCS MAINLY STAYING SOUTH OF CWA...WOULD BE CLOSE IN THE SOUTHWEST CWA THOUGH. ON THE OTHER HAND...IF CONVECTION OVR NORTHEAST ND CONTINUES TO DRIFT ACROSS RIDGE TOP IT COULD ADVECT AND/OR SPUR ON ADDITIONAL SHRA/TSRA OVERNIGHT IN NORTHERN MN AND BASED ON 850-300MB THICKNESSES...SHRA/TSRA WOULD TRACK INTO FAR WESTERN UPR MICHIGAN 08Z-12Z. INCREASING SFC-ML CAPES AND 0-1KM SHEAR UP TO 20 KTS AND BOW-LIKE APPEARANCE FROM VARIOUS HIGHER RESOLUTION MODELS INDICATE IF THIS CONVECTION IMPACTS WESTERN CWA THERE COULD BE STRONG WIND GUSTS. WITH ALL THE CLOUD COVER AND POSSIBLE SHRA/TSRA WILL BE A WARM NIGHT WITH LOWS IN THE MID 50S EAST AND STAYING ABOVE 60 DEGREES OVER THE WEST. FOR FRIDAY...CONDITIONAL FORECAST FOR SURE. IF THE SHRA/TSRA ARE AROUND IN THE MORNING...EXPECT A GENERAL LULL LATE MORNING INTO MOST OF THE AFTN DUE TO THE SUBSIDENCE IN WAKE OF THE CONVECTION. MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 70S IF NOT REACHING 80 WITH ENOUGH SUNSHINE. AFTN INSTABILITY AND WARM FRONT/OUTFLOW IN THE VCNTY COULD LEAD TO MORE DEVELOPING SHRA/TSRA MID-LATE AFTN. LOW CHANCE POPS FOR ALL AREAS AFTER THE MAIN SHRA/TSRA CHANCES IN THE MORNING. BEST CHANCE IN THE AFTN WOULD PROBABLY BE IN THE WEST/SOUTHWEST CWA WITH BETTER SHOT OF EARLIER CLEARING/WARMER TEMPERATURES. HUMID CONDITIONS THAT HAVE DEVELOPED TODAY WILL CONTINUE THROUGH FRIDAY WITH DWPNTS STAYING AT OR ABOVE 60 IN MANY AREAS. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 431 PM EDT THU JUN 20 2013 FRI NIGHT... AFTER THE EXPECTED AREA OF SHRA/TSRA EXITS THE ERN CWA FRI EVENING... CONSENSUS OF MODELS SUGGEST PERHAPS A BREAK IN SHRA/TSRA BY LATE FRI EVENING BEFORE MORE CONVECTION DEVELOPS OVER THE UPPER MS VALLEY ALONG THE 850 MB WARM FRONT. THE FCST REFLECTS MODEL TRENDS THAT KEEP THE FOCUS FOR CONVECTIVE DEVELOPMENT WITH THE GREATEST INSTABILITY AND NOSE OF THE LLJ FARTHER SOUTH COMPARED TO EARLIER RUNS. SATURDAY AND SUNDAY... AS THE MID LEVEL RIDGE BUILDS TO THE EAST...SW FLOW PATTERN WILL ALLOW THE 850 MB WARM FRONT TO PUSH TO THE NORTH WITH WARM AND HUMID AIR BECOMING ENTRENCHED OVER THE REGION. EVEN THOUGH THE MODELS HINT AT POTENTIAL FOR A SHORTWAVE TROUGH MOVING OUT OF THE PLAINS TOWARD NW ONTARIO SAT INTO SAT EVENING...UNCERTAINTY WITH THE TIMING/POSITION OF THIS FEATURES AND THE IMPACT ON CONVECTIVE DEVELOPMENT IS HIGH. WITH THE FOCUS FOR MOISTURE/LOW LEVEL THETA-E ADVECTION SHIFTING FROM THE UPPER MS VALLEY TOWARD THE AREA...POPS INCREASE INTO THE WRN CWA BY LATE AFTERNOON AND ACROSS UPPER MICHIGAN SATURDAY NIGHT. WITH MLCAPE/MUCAPE VALUES INCREASING AT LEAST INTO THE 1K-2K J/KG RANGE...THERE WILL BE A GREATER POTENTIAL FOR STRONGER STORMS. THE MAIN HAZARD WILL BE HEAVY RAIN AS PWAT VALUES CLIMB TO 1.5 TO 1.8 INCHES (150-180 PCT OR NORMAL). WITH THE RIDGE BUILDING INTO THE AREA SUNDAY...CIN WILL INCREASE WITH 700 MB TEMPS INTO THE 10C-12C RANGE. SO...TEMPS WILL CLIMB WELL ABOVE NORMAL INTO THE 80S AND CONVECTION POTENTIAL WILL DECREASE. HOWEVER...SHRA/TSRA MAY INCREASE AGAIN BY SUNDAY NIGHT AS A STRONGER SHRTWV HELPS FLATTEN THE RIDGE AND BRINGS A WEAK SFC TROUGH INTO THE REGION. MON-THU... THERE MAY BE DRIER PERIOD WITH A WEAK MID LEVEL AND SFC RIDGE INTO THE AREA MON INTO TUE. HOWEVER...CONFIDENCE REMAINS LOW WITH THE RETROGRADING RIDGE LEADING TO A MORE ZONAL PATTERN. AS THE RIDGE BUILDS OVER THE WRN CONUS...A MORE NW FLOW PATTERN WILL STILL KEEP POTENTIAL FOR SHRA/TSRA GOING. TEMPS SHOULD TRANSITION BACK TOWARD MORE NORMAL VALUES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 802 PM EDT THU JUN 20 2013 CHALLENGING FCST SHAPING UP FOR THIS FCST PERIOD DUE TO UNCERTAINTIES IN CONVECTION AND POTENTIAL OF LOW CLOUDS/FOG. INITIALLY...MAIN AREAS OF TSRA SHOULD SLIDE SE TO THE S OF THE AREA THIS EVENING AS CONVECTION FOLLOWS 850-300MB THICKNESS PATTERN. FARTHER N...SHRA WILL AFFECT KIWD/KCMX/KSAW PER RADAR TRENDS. VFR CONDITIONS SHOULD GENERALLY PREVAIL AT KIWD/KSAW THOUGH SOME MVFR IS POSSIBLE. AT KCMX...COOL EASTERLY UPSLOPE FLOW OFF LAKE SUPERIOR INTO HIGHER DWPT AIR MASS OVER THE KEWEENAW SHOULD EVENTUALLY LEAD TO FOG/STRATUS WITH LIFR/IFR CONDITIONS DEVELOPING LATE EVENING OR OVERNIGHT. LATER TONIGHT...DISTURBANCE EMERGING FROM THE NRN PLAINS SHOULD SUPPORT A MORE ORGANIZED CLUSTER OF SHRA/TSRA SPREADING TOWARD THE AREA. GIVEN ARRIVAL DURING THE MORNING IN THE USUAL DIURNAL MIN FOR CONVECTION...TSRA POTENTIAL APPEARS TO BE ON THE LOWER SIDE. INCLUDED MVFR CONDITIONS WITH SHRA/VCTS AT KIWD...BUT JUST SHRA AT KCMX/KSAW. AFTER A FEW HRS OF PCPN...CONDITIONS SHOULD BREAK OUT TO VFR AT KIWD/KSAW...BUT MAY RETURN TO IFR UNDER CONTINUED COOL UPSLOPE EASTERLY FLOW AT KCMX. EXPECT A BREAK OUT TO VFR AT KCMX IN THE AFTN. ADDITIONAL CONVECTIVE DEVELOPMENT FRI AFTN IS UNCERTAIN. FOR NOW...WILL PLAN FOR A MORE LIKELY DRY SCENARIO IN THE WAKE OF SHORTWAVE PASSING IN THE MORNING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 431 PM EDT THU JUN 20 2013 FOG...AND ANY STRONGER STORMS /WITH WINDS AND/OR SMALL HAIL/ WILL BE THE MAIN HAZARDS THROUGH THE WEEKEND. OTHERWISE WINDS SHOULD REMAIN AT OR BELOW 25KTS. A TROUGH OF ACROSS LAKE SUPERIOR WILL...DEEPEN FRIDAY NIGHT...AND AGAIN SUNDAY THROUGH MONDAY. THIS WILL BE IN RESPONSE TO AN ELONGATED AREA OF LOW PRESSURE STRETCHING FROM SOUTHWESTERN CANADA THROUGH EASTERN COLORADO. EXPECT THE AREA OF LOW PRESSURE TO CONSOLIDATE ACROSS THE CENTRAL PLAINS ON SATURDAY...BEFORE SHIFTING INTO MANITOBA ON SUNDAY...AND EXITING EASTWARD THROUGH ONTARIO ON MONDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...JLB AVIATION...ROLFSON MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 PM EDT WED JUN 19 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 429 PM EDT WED JUN 19 2013 WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW THROUGH THEN NRN GREAT LAKES BETWEEN A TROUGH OVER ERN CANADA AND A RIDGE OVER THE PLAINS. SCT SHRA AND ISOLD TSRA HAD DEVELOPED NEAR CYRL ON THE TAIL OF A SHORTWAVE TROUGH THROUGH NW ONTARIO. AN UPSTREAM SHRTWV WAS ALSO LOCATED OVER ERN SD. AT THE SFC...SRLY WINDS HAD INCREASED BETWEEN HIGH PRES OVER THE ERN GREAT LAKES AND A TROUGH EXTENDING INTO ND FROM LOW PRES W OF JAMES BAY. LOW LEVEL MOISTURE WAS ONLY SLOWLY INCREASING WITH DEWPOINTS CLIMBING TO NEAR 50F OVER THE WEST. TONIGHT...EVEN THOUGH THE FORCING WITH THE NW ONTARIO SHRTWV WILL REMAIN NORTH OF THE CWA...MODELS SUGGEST THAT THE SHRA AND POSSIBLY SOME TSRA WILL DEVELOP LATER THIS EVENING NW OF LAKE SUPERIOR AND SLIDE INTO THE WRN CWA OVERNIGHT. MOISTURE TRANSPORT AND THE POSITION OF THE 850-700 MB FRONTAL ZONE FAVORS GREATER PCPN CHANCES/COVERAGE OVER NW LAKE SUPERIOR INTO MAINLY THE NW CWA. MUCAPE VALUES ARE EXPECTED TO BE HIGH ENOUGH FOR ELEVATED TSRA DEVELOPMENT. THURSDAY...THE COMBINATION OF INCREASING MOISTURE TRANSPORT...DAYTIME HEATING AND THE SD SHRTWV SHOULD BRING INCREASING SHRA/TSRA COVERAGE ACROSS THE CWA. ALTHOUGH INSTABILITY WILL BE MARGINAL FOR STRONGER STORMS WITH MLCAPE VALUES INTO THE 500-1000 J/KG RANGE...AND A RELATIVELY NARROW CAPE PROFILE....SOME STORMS WITH SMALL HAIL AND GUSTY WINDS TO 35 MPH MAY BE POSSIBLE. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 429 PM EDT WED JUN 19 2013 CONVECTION WILL MAKE FOR A VERY TRICKY AND UNCERTAIN FORECAST THU NIGHT THROUGH AT LEAST THE WEEKEND. AN UPPER RIDGE WILL MOVE E INTO THE AREA THU NIGHT THROUGH THE MIDDLE OF NEXT WEEK. AT THE SFC...A WEAK LOW WILL REMAIN FAIRLY STATIONARY OVER THE CENTRAL AND NRN PLAINS...LEAVING A WARM FRONT ACROSS OR NEAR THE CWA THROUGH THIS WEEKEND. CONFIDENCE IS VERY LOW /AS WITH MOST CONVECTIVE SITUATIONS/ WITH THE EXACT TRACK/TIMING OF ANY CONVECTIVE COMPLEXES MOVING ALONG OR NEAR THE WARM FRONT. MODELS SHOW MULTIPLE SCENARIOS FOR CONVECTIVE DEVELOPMENT AND MOVEMENT...INCLUDING MOVING THE WARM FRONT N OF THE CWA KEEPING THE BULK OF CONVECTION N OF THE CWA...TO HAVING THE WARM FRONT STALL S OF THE CWA WHICH WOULD KEEP MOST OF THE CONVECTION S. OVERALL...THE BULK OF THE MODELS SHOW CONVECTIVE COMPLEXES MOVING OVER THE CWA...SO WILL CONTINUE TO PUT THAT INTO THE FORECAST AS HAS BEEN DONE BY PREVIOUS SHIFTS. SOME OF THE THUNDERSTORMS COULD VERY WELL BE STRONG WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS...BUT CONFIDENCE IS STILL TOO LOW TO INCORPORATE THAT INTO THE FORECAST BUT WILL CONTINUE SOME MENTION OF STRONGER STORMS IN THE HWO. SPC HAS AREAS ALONG THE BORDER UNDER A SLIGHT RIGHT...AND GENERALLY AGREE WITH THAT GIVEN THE LOCATION OF THE GREATEST INSTABILITY. MODELS SHOW UP TO 4500J/KG /GFS/ OF SBCAPE NOSING INTO WRN UPPER MI FRI AFTERNOON...BUT THAT IS THE HIGHEST AMOUNT AND LOOKS LIKE LOW LEVELS ARE OVERLY MOIST IN THE MODEL. THE NAM IS ANOTHER MODEL THAT SEEMS TOO HIGH ON LOW LEVEL MOISTURE AND SBCAPE AT UP TO 3500J/KG ON FRI. ECMWF AND GEM SEEM MORE REASONABLE AT 1000-1500J/KG ALONG THE WI BORDER SO WILL FAVOR THAT SOLUTION. COULD HAVE DAYTIME CONVECTION BREAK OUT OVER WRN AND CENTRAL UPPER MI...BUT MOST LIKELY SCENARIO AT THIS POINT CONTINUES TO BE CONVECTION FORMING UPSTREAM AND MOVING TO THE ESE ALONG THE FORWARD PROPAGATING CORFIDI VECTORS AND INSTABILITY GRADIENT FRI. ANOTHER RISK FACTOR WILL BE HEAVY RAIN WITH ANY THUNDERSTORMS AS PWATS WILL BE 150-200 PERCENT OF NORMAL. SAT AND SUN LOOK SIMILAR TO FRI...WITH SIMILAR UNCERTAINTY DUE TO CONVECTIVE UNCERTAINTY. IN FACT...SIMILAR CONDITIONS SHOULD BE OBSERVED INTO THE MIDDLE OF NEXT WEEK...BUT CONFIDENCE INCREASES TOO MUCH MON-WED TO TALK TOO MUCH ABOUT THIS TIME FRAME. LOOKING AT TEMPS...SHOULD SEE SFC TEMPS INCREASE SLIGHTLY FROM DAY TO DAY THROUGH THE FORECAST PEROID WITH HIGHS IN THE 80S ACROSS A LARGE PART OF UPPER MI BY SUN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 141 PM EDT WED JUN 19 2013 VFR CONDITIONS ARE EXPECTED TO PREVAIL THIS AFTERNOON INTO THIS EVENING EVEN AS LOW LEVEL MOISTURE INCREASES WITH SRLY FLOW. BY LATE TONIGHT INTO THURSDAY MORNING...THE COMBINATION OF A SHORTWAVE TROUGH AND AN ADVANCING WARM FRONT WILL SUPPORT SOME SHOWERS THAT WILL SPREAD INTO UPPER MICHIGAN. MAINLY VFR CONDITIONS SHOULD STILL PERSIST...BUT IF A MORE PERSISTENT AREA OF RAIN DEVELOPS CIGS COULD DROP INTO THE MVFR RANGE. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 429 PM EDT WED JUN 19 2013 WINDS SHOULD REMAIN BELOW 25KTS THROUGH THE PERIOD...WITH RELATIVELY LOW WAVES. THE MAIN HAZARD WILL BE STRONGER WINDS/HAIL/LIGHTNING WITH ANY THUNDERSTORMS MOVING ACROSS LAKE SUPERIOR FROM LATE TONIGHT THROUGH INTO EARLY NEXT WEEK. AREAS OF FOG THAT DEVELOP AS A RESULT OF INCREASED MOISTURE AND SHOWER ACTIVITY MAY ALSO BECOME LOCALLY DENSE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
455 AM EDT WED JUN 19 2013 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 409 PM EDT TUE JUN 18 2013 WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW THROUGH THE NRN GREAT LAKES BETWEEN A TROUGH OVER QUEBEC AND A RIDGE FROM THE ROCKIES INTO THE WRN PLAINS. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY TO LAKE SUPERIOR. WITH THE DRY AIRMASS OVER THE REGION (PWAT AROUND 0.50 OR ABOUT 50 PCT OF NORMAL)...A WEAK SHORTWAVE TROUGH INTO WRN LAKE SUPERIOR ONLY SUPPORTED A PATCH OF MID/HIGH CLOUDS. TONIGHT...HIGH PRESSURE WILL CONTINUE TO DOMINATE THE REGION KEEPING CONDITIONS DRY UNDER MOSTLY CLEAR SKIES. AS THE RIDGE AXIS SLIDES SE OVERNIGHT...LIGHT RETURN SRLY FLOW WILL RESULT IN A BIT MORE MIXING ESPECIALLY OVER THE FAR WEST AND ALONG THE LAKE SUPERIOR SHORELINE. LOOK FOR MIN TEMPS TO RANGE FROM AROUND 40 INLAND TO THE MID TO UPPER 40S ALONG THE GREAT LAKES SHORELINES. WEDNESDAY...AS THE RIDGE SLOWLY SLIDES OFF TO THE EAST...SRLY WINDS WILL INCREASE. 850 MB TEMPS AROUND 10C AND MIXING TO AROUND 800 MB WILL SUPPORT TEMPS INTO THE MID 70S INLAND...EXCEPT NEAR LAKE MICHIGAN WHERE ONSHORE FLOW KEEPS READINGS IN THE 60S. ALTHOUGH MOISTURE WILL ALSO INCREASE SLIGHTLY...THE HIGHER LOW LEVEL THETA-E AXIS TO SUPPORT SHRA/TSRA WITH WEAK SHRTWVS IN NW FLOW IS EXPECTED TO REMAIN WEST OF THE CWA. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 409 PM EDT TUE JUN 18 2013 AREA WILL BE UNDER NORTHWEST FLOW ALOFT TO START THE PERIOD AS THE UPPER GREAT LAKES IS ON THE EASTERN SIDE OF THE RIDGE OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY. A WEAK SHORTWAVE WILL BE SLIDING ACROSS NORTHEAST LAKE SUPERIOR ON WEDNESDAY NIGHT...WHILE A SURFACE TROUGH DROPS SOUTHEAST ACROSS THE CWA DURING THE OVERNIGHT PERIOD. THERE WILL LIKELY BE SOME SHOWERS AND A FEW THUNDERSTORMS WITH THIS TROUGH ON WEDNESDAY NIGHT AND WILL FOLLOW A GENERAL CONSENSUS FOR THE TIMING OF THE POPS AS IT MOVES IN. THIS FRONT LOOKS TO STALL ACROSS UPPER MICHIGAN ON THURSDAY AND WILL COMBINE WITH DEVELOPING LAKE BREEZES TO PRODUCE AFTERNOON SHOWERS AND THUNDERSTORMS. THE STRENGTH OF THESE THUNDERSTORMS WILL DEPEND ON THE AMOUNT OF DIURNAL HEATING...INCREASING SOUTHERLY FLOW WITH A DEVELOPING WARM FRONT ON THE BOUNDARY...AND THE ARRIVAL OF THE ANOTHER WEAK SHORTWAVE DURING THE LATE AFTERNOON AND EVENING. ML CAPE VALUES OF 500-1000 J/KG OVER THE WESTERN 2/3RDS OF THE CWA AND 0-6KM BULK SHEAR VALUES AROUND 30KTS SUPPORTS THUNDERSTORMS AND SOME TILTING OF THE UPDRAFTS. HEAVY RAIN AND SMALL HAIL WILL BE THE PRIMARY THREATS...AS NCAPE VALUES AROUND .1 SHOULD KEEP ANY HAIL FROM GROWING TOO LARGE. WILL CONTINUE TO HIGHLIGHT THE HIGHEST POPS OVER THE INTERIOR WEST/CENTRAL...CLOSEST TO LAKE SUPERIOR LAKE BREEZE AND THEN FOLLOW THE STORM MOTION TO THE SOUTHEAST. THURSDAY NIGHT THROUGH THE WEEKEND IS SHAPING UP TO BE A FAIRLY ACTIVE PATTERN FOR THUNDERSTORMS IN THE UPPER MISSISSIPPI VALLEY AND UPPER GREAT LAKES REGION. THIS IS DUE TO THE UPPER RIDGE GRADUALLY SHIFTING EAST INTO THE UPPER GREAT LAKES. MEANWHILE...WEAK SURFACE LOW WILL REMAIN FAIRLY STATIONARY OVER THE CENTRAL/NORTHERN PLAINS. FROM THIS LOW...A WARM FRONT WILL LOOKS TO SETUP FROM THE STALLED TROUGH ON THURSDAY AND REMAIN LOCATED AROUND THE UPPER GREAT LAKES REGION THROUGH THE WEEKEND. LOOKING AT THIS LARGE SCALE PATTERN...IT IS VERY CONDUCIVE PERIODS OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS. BUT TRYING TO PIN DOWN THE EXACT LOCATION AND TIMING IS DIFFICULT DUE TO THE VARIABILITY OF THE SHORTWAVES AND POSITION OF THE WARM FRONT. INSTABILITY WILL GRADUALLY GROW FROM FRIDAY INTO THE WEEKEND...AS PERSISTENT SOUTHWESTERLY FLOW AHEAD OF THE LOW PULLS PLENTY OF GULF MOISTURE INTO THE AREA. USING ML CAPE VALUES TO REMOVE SOME OF THE LOW LEVEL MOIST BIASES IN THE MODELS FOR FRIDAY INTO THE WEEKEND...THERE ARE STILL SOME DECENT VALUES FOR U.P. STANDARDS. FRIDAY THEY LOOK TO PEAK IN THE 750-1500 J/KG RANGE OVER THE WEST AND THEN GROW TO 1500-2500 J/KG FOR SAT/SUN DEPENDING ON THE MODEL. THE GFS IS THE MOST AGGRESSIVE ON THE NORTHWARD EXTENT OF THE WARM FRONT...WHILE THE GEM/ECMWF TRY TO KEEP THE FRONT A TOUCH SOUTH OF THE AREA. IT WILL PROBABLY BE A VARIETY OF THUNDERSTORM TYPES DURING THAT PERIOD. CONVECTIVE COMPLEXES MOVING EAST /VIA FORWARD PROP CORFIDI VECTORS/ AROUND THE RIDGE WILL LIKELY BE THE MAIN THREAT...BUT WITH THE INSTABILITY PRESENT AND LIMITED INHIBITION...DIURNAL THUNDERSTORMS WILL ALSO BE POSSIBLE. THE ONLY CONCERNS WOULD BE IF THE RIDGE AND WARM FRONT BUILD FAR ENOUGH NORTH TO SLIDE MOST OF THE THUNDERSTORM COMPLEXES NORTH OF UPPER MICHIGAN OR THE MORE LIKELY SCENARIO OF IT BECOMING HUNG UP SOUTH OF THE AREA /ESPECIALLY AS CONVECTION HOLDS THEM SOUTH/. WITH THE GROWING CONFIDENCE...WILL ADD A MENTION OF STRONG THUNDERSTORMS FOR THE WEEKEND IN BOTH THE HWO AND EHWO. HEAVY RAIN IS ALSO POSSIBLE DURING THIS PERIOD WITH THE THUNDERSTORMS...AS PWAT VALUES RISE ABOVE 1.5 INCHES WHICH IS WELL ABOVE THE 75TH PERCENTILE FOR CLIMATOLOGY FOR THIS AREA. IT WILL BE PRETTY HUMID FOR FRIDAY INTO THE WEEKEND /DEWPOINTS IN THE UPPER 50S AND 60S/ AND THE TEMPERATURES WILL DEPEND ON THE POSITIONING OF THE WARM FRONT. WILL CONTINUE TO SHOW TEMPS IN THE MID 70S TO LOWER 80S FOR MOST LOCATIONS...WITH THE WARMEST VALUES NEAR THE WISCONSIN BORDER. IF THE GFS ENDS UP BEING CORRECT...WOULD HAVE TO BUMP TEMPS UP WELL INTO THE 80S FOR THE END OF THE WEEKEND. UNCERTAINTY REALLY GROWS HEADING INTO MONDAY/TUESDAY...AS A LOT DEPENDS ON THE WEEKEND WEATHER. THE GENERAL IDEA FROM THE MODELS IS THAT THE RIDGE BREAKS DOWN AND THE AREA WILL BE UNDER ZONAL FLOW ALOFT. THIS WILL CONTINUE TO BRING WAVES ACROSS THE AREA AND KEEP THE THUNDERSTORM POTENTIAL IN PLACE FOR THAT PERIOD. AT THIS TIME...MODELS ARE INDICATING A COLD FRONT DROPPING SOUTH OUT OF CANADA ON WEDNESDAY...WHICH MAY BRING AN END TO THE WARM/HUMID WEATHER. FINALLY...WILL CONTINUE TO MENTION PATCHY FOG DEVELOPING ON LAKE SUPERIOR ON WEDNESDAY NIGHT AND THEN CONTINUING INTO EARLY NEXT WEEK. WILL LIKELY NEED TO EXPAND IT TO AREAS OR EVEN DENSE FOG AS IT NEARS. ALSO...ADDED A MENTION OF FOG OVER LAKE MICHIGAN NEARSHORE AREAS STARTING LATE THURSDAY NIGHT AS THE PRECIPITATION AND HIGHER DEWPOINTS START TO AFFECT THAT AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1203 AM EDT WED JUN 19 2013 WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS EXPECTED TO CONTINUE THROUGH THE PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 455 AM EDT WED JUN 19 2013 WINDS SHOULD REMAIN BELOW 25KTS THROUGH THE PERIOD...WITH RELATIVELY LOW WAVES. THE MAIN THREAT WILL BE STRONG WINDS/HAIL/LIGHTNING WITH ANY THUNDERSTORMS MOVING ACROSS LAKE SUPERIOR FROM LATE TONIGHT THROUGH THE WEEKEND AND BEYOND...AND PATCHY TO AREAS OF FOG THAT DEVELOP AS A RESULT OF INCREASED MOISTURE AND SHOWER ACTIVITY. HIGH PRESSURE CENTERED OVER LAKE HURON WILL CONTINUE TO SINK SOUTHEASTWARD...AS A LOW OVER NORTHERN ONTARIO SWINGS INTO QUEBEC. A TROUGH EXTENDING FROM THE CANADIAN LOW WILL DRIFT ACROSS LAKE SUPERIOR LATE TONIGHT INTO THURSDAY. THE TROUGH SHOULD STRENGTHEN THURSDAY NIGHT THROUGH SATURDAY...AS HIGH PRESSURE PUSHES ACROSS ONTARIO...AND AN ELONGATED AREA OF LOW PRESSURE ORGANIZES ACROSS THE NORTHERN AND CENTRAL PLAINS. THE TROUGH WILL FURTHER DEEPEN OVER LAKE SUPERIOR ON SUNDAY AS THE MAIN LOW PUSHES NORTHWARD THROUGH THE DAKOTAS AND INTO SOUTH CENTRAL CANADA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...07 MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1257 PM CDT WED JUN 19 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM CDT WED JUN 19 2013 CIRRUS SHIELD NOTED ON IR SATELLITE ENTERING FAR WESTERN MN. SHIELD IS JUST AHEAD OF DEEPENING SURFACE CYCLONE ABOVE EASTERN MONTANA. THIS FEATURE WILL BE EJECTED OUT OF 50H TROF OVER PACIFIC NW DURING THE NEXT 24 HOURS INTO WESTERN NODAK AND SOUTHERN SASKATCHEWAN. WARM FRONTAL BOUNDARY ATTACHED TO SURFACE CYCLONE WILL BE CATALYST FOR SCATTERED SHOWERS AND ISOLATE THUNDERSTORMS LATE THIS MORNING OVER FAR WESTERN CWA. USED GFS40 THETA E ADVECTION AND HRRR GUIDANCE FOR PLACEMENT AND TIMING OF DAYTIME CONVECTION OVER FA. COULD BE A FEW STRONG TO NEAR SEVERE THUNDERSTORMS THIS AFTERNOON OVER CENTRAL AND PORTIONS OF SW MN TO...AS JOULES INCREASE INTO THE 1500 TO 2500 RANGE. MODERATE 250MB DIVERGENCE COUPLETS ALSO NOTED OVER THESE AREAS ALONG WITH LI`S PLUNGING INTO THE NEGATIVE 4 TO NEGATIVE 8 CATEGORY. ONLY LIMITING FACTOR WOULD BE THICKER CLOUD DECK THEN CURRENT CIRRUS SHIELD PROGGED FOR MUCH OF THE DAYTIME HOURS. PRESENCE AND PROGRESSION OF WARM FRONTAL BOUNDARY DEEPER INTO SOUTHERN HALF OF MN TONIGHT SHOULD PORTEND SLIGHTLY ENHANCED CHANCES FOR CONVECTION...WITH QPF VALUES ALSO RISING NOTICEABLY. COULD BE A QUICK QUARTER INCH TO ONE HALF INCH OF MOISTURE GENERATE FROM CONTINUE SCT ACTIVITY DURING THE OVERNIGHT. 850MB LAPSE RATES AND LI`S WILL ALSO RISE SLIGHTLY OVERNIGHT. MODERATE SOUTHERLY LOW LEVEL JET WILL ALSO FORM BY LATE TONIGHT OVER MUCH OF MN FA ...WITH 25 TO 30KT MAGNITUDES COMMON SOUTH OF A LINE FROM ALEXANDRIA TO OWATONNA. COULD BE ADDITIONAL ISOLATED STRONG TO NEAR SEVERE T-STORMS OVER WESTERN HALF OF FA DURING THE EVENING...SWITCHING TO FAR EAST CENTRAL MN/WEST CENTRAL WI AFTER MIDNIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 410 AM CDT WED JUN 19 2013 WARM AND MOISTURE-RICH PATTERN WILL REMAIN IN PLACE FOR THE END OF THIS WEEK INTO THE START OF NEXT WEEK...INCLUDING PERIODS OF STRONG THUNDERSTORMS AND HEAVY RAIN. AN UPPER LEVEL RIDGE BUILDING OVER THE DAKOTAS AND MN/WI THRU TDA WILL SHIFT TO THE E THRU THU WHILE A LONGWAVE TROUGH DEVELOPS OVER THE NORTHWEST. SEVERAL SHORTWAVE DISTURBANCES RIDING NOT ONLY OVER TOP THE RIDGE BUT ALSO AROUND THE BASE OF THE TROUGH THU INTO FRI WILL WORK WITH AN INCOMING SFC FRONTAL SYSTEM DEVELOPING OVER THE CENTRAL-NRN PLAINS. SOLID SW FLOW WILL BRING NOT ONLY WARMER AIR /WHICH WILL RAISE H5 HEIGHTS TO ENHANCE CAPPING BUT ALSO STRONGER JETTING/ BUT ALSO MOISTURE-RICH AIR /HELPING RAISE PWATS ABOVE 1.50 INCHES AND ENHANCE INSTABILITY/...AND THE SFC FRONTAL WAVES COMBINED WITH UPPER LEVEL DISTURBANCES WILL ALLOW FOR PERIODS OF CONVECTION. THURSDAY CONTINUES TO BE HIGHLIGHTED BY SPC INVOF THE APCHG CDFNT FOR THE WRN HALF OF MN. ONCE THE CAPPING INVERSION IS LOST OVER WRN MN...STRONG MID- AND UPPER-LEVEL JETTING WITH STEEP LAPSE RATES WITHIN A HIGHLY UNSTABLE ENVIRON /INCLUDING DEWPOINTS NEAR- OVER 70 DEGREES/ WILL PROMOTE STRONG TO SEVERE TSTMS CAPABLE OF PRODUCING LARGE HAIL AND DMGG WINDS. THE REGIME THEN TRANSITIONS TO ONE OF HEAVY RAIN OVER THE WEEKEND AS THE SFC LOW PRES SYSTEM OPENS UP AND BECOMES CAUGHT UP IN THE PROLIFIC SWLY FLOW WHILE THE NW UPPER LEVEL TROUGH OPENS TO MORE OF A TROUGH THAN CUTOFF LOW. LONG PLUME OF SLY SFC FLOW WILL AID IN BRINGING MOISTURE WELL N INTO THE UPPER MISS RIVER VALLEY REGION. MODEL QPF CONTINUES TO ADVERTISE BETWEEN 3 AND 6 INCHES OF RAIN FOR THE AREA THROUGH THE WEEKEND...BUT WITH MUCH OF IT CONVECTIVE...TRYING TO PINPOINT WHERE SUCH RAINFALL EVENTS MAY OCCUR IS HIGHLY PROBLEMATIC. STILL...HAVE KEPT HIGH-END CHC POPS GOING IN THE FCST. POPS DIMINISH FOR THE START OF NEXT WEEK AS A MORE ZONAL UPPER LEVEL PATTERN DEVELOPS...KEEPING ANY ORGANIZED LOW PRES SYSTEMS AWAY FROM THE AREA. THAT SAID...SEVERAL MID- AND UPPER-LEVEL SHORTWAVE DISTURBANCES WILL STILL BE CAPABLE OF PRODUCING ISOLD TO SCATTERED CONVECTION AS THE WARM/MOIST AIR WILL REMAIN IN PLACE THROUGH EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1250 PM CDT WED JUN 19 2013 THE CU FIELD IS EXPANDING ACROSS THE MN RIVER VALLEY AND A FEW SHOWERS/TSTMS COULD OCCUR THIS AFTERNOON IN THIS AREA AS TEMPS PEAK IN THE UPPER 80S. A FEW ELEVATED SHOWERS/TSTMS MAY ALSO OCCUR IN WEST CENTRAL WI AS MID LEVEL INSTABILITY MOVES THROUGH. THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL INCREASE DURING THE EVENING FOR KAXN AND KRWF WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING INTO THE TWIN CITIES AND WEST CENTRAL WI DURING THE OVERNIGHT HOURS. THE ACTIVITY WILL LINGER OVER EASTERN AREAS THURSDAY MORNING. THERE IS NO REAL FOCUS ON THE SHOWERS AND THUNDERSTORMS TONIGHT/EARLY THURSDAY AND MUCH WILL RELY ON THE DEVELOPMENT OVER THE DAKOTAS LATER THIS AFTERNOON AND TONIGHT. A MUCH BETTER CHANCE FOR STRONG TO SEVERE STORMS WILL EXIST THURSDAY AFTERNOON AND NIGHT ACROSS WESTERN AND SOUTHERN MN AS A FRONTAL BOUNDARY INCHES CLOSER TO THE AREA. LOOK FOR SE WINDS FROM 10 TO 15 KNOTS THIS AFTERNOON WITH SOME GUSTS TO AROUND 20 FOR KAXN AND KRWF. KMSP...VFR EXPECTED THROUGH THE PERIOD. THE BEST CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS IS FROM LATE TONIGHT THROUGH THURSDAY MORNING. TEMPORARY DIPS TO MVFR CAN BE EXPECTED IN THE BOUTS OF PRECIPITATION. SE WINDS THIS AFTERNOON AND TONIGHT NEAR 10 KNOTS. /OUTLOOK FOR KMSP/ THU NIGHT...VFR. CHC OF MVFR/TSRA. SE WINDS 10 KTS. FRI...VFR. CHC OF MVFR/TSRA. SE WINDS 10 KTS. SAT...VFR. CHC OF MVFR/TSRA. SE WINDS 8 KTS. SUN...VFR. CHC OF MVFR/TSRA. S WINDS 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...AJZ LONG TERM...JPC AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
623 AM CDT WED JUN 19 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM CDT WED JUN 19 2013 CIRRUS SHIELD NOTED ON IR SATELLITE ENTERING FAR WESTERN MN. SHIELD IS JUST AHEAD OF DEEPENING SURFACE CYCLONE ABOVE EASTERN MONTANA. THIS FEATURE WILL BE EJECTED OUT OF 50H TROF OVER PACIFIC NW DURING THE NEXT 24 HOURS INTO WESTERN NODAK AND SOUTHERN SASKATCHEWAN. WARM FRONTAL BOUNDARY ATTACHED TO SURFACE CYCLONE WILL BE CATALYST FOR SCATTERED SHOWERS AND ISOLATE THUNDERSTORMS LATE THIS MORNING OVER FAR WESTERN CWA. USED GFS40 THETA E ADVECTION AND HRRR GUIDANCE FOR PLACEMENT AND TIMING OF DAYTIME CONVECTION OVER FA. COULD BE A FEW STRONG TO NEAR SEVERE THUNDERSTORMS THIS AFTERNOON OVER CENTRAL AND PORTIONS OF SW MN TO...AS JOULES INCREASE INTO THE 1500 TO 2500 RANGE. MODERATE 250MB DIVERGENCE COUPLETS ALSO NOTED OVER THESE AREAS ALONG WITH LI`S PLUNGING INTO THE NEGATIVE 4 TO NEGATIVE 8 CATEGORY. ONLY LIMITING FACTOR WOULD BE THICKER CLOUD DECK THEN CURRENT CIRRUS SHIELD PROGGED FOR MUCH OF THE DAYTIME HOURS. PRESENCE AND PROGRESSION OF WARM FRONTAL BOUNDARY DEEPER INTO SOUTHERN HALF OF MN TONIGHT SHOULD PORTEND SLIGHTLY ENHANCED CHANCES FOR CONVECTION...WITH QPF VALUES ALSO RISING NOTICEABLY. COULD BE A QUICK QUARTER INCH TO ONE HALF INCH OF MOISTURE GENERATE FROM CONTINUE SCT ACTIVITY DURING THE OVERNIGHT. 850MB LAPSE RATES AND LI`S WILL ALSO RISE SLIGHTLY OVERNIGHT. MODERATE SOUTHERLY LOW LEVEL JET WILL ALSO FORM BY LATE TONIGHT OVER MUCH OF MN FA ...WITH 25 TO 30KT MAGNITUDES COMMON SOUTH OF A LINE FROM ALEXANDRIA TO OWATONNA. COULD BE ADDITIONAL ISOLATED STRONG TO NEAR SEVERE T-STORMS OVER WESTERN HALF OF FA DURING THE EVENING...SWITCHING TO FAR EAST CENTRAL MN/WEST CENTRAL WI AFTER MIDNIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 410 AM CDT WED JUN 19 2013 WARM AND MOISTURE-RICH PATTERN WILL REMAIN IN PLACE FOR THE END OF THIS WEEK INTO THE START OF NEXT WEEK...INCLUDING PERIODS OF STRONG THUNDERSTORMS AND HEAVY RAIN. AN UPPER LEVEL RIDGE BUILDING OVER THE DAKOTAS AND MN/WI THRU TDA WILL SHIFT TO THE E THRU THU WHILE A LONGWAVE TROUGH DEVELOPS OVER THE NORTHWEST. SEVERAL SHORTWAVE DISTURBANCES RIDING NOT ONLY OVER TOP THE RIDGE BUT ALSO AROUND THE BASE OF THE TROUGH THU INTO FRI WILL WORK WITH AN INCOMING SFC FRONTAL SYSTEM DEVELOPING OVER THE CENTRAL-NRN PLAINS. SOLID SW FLOW WILL BRING NOT ONLY WARMER AIR /WHICH WILL RAISE H5 HEIGHTS TO ENHANCE CAPPING BUT ALSO STRONGER JETTING/ BUT ALSO MOISTURE-RICH AIR /HELPING RAISE PWATS ABOVE 1.50 INCHES AND ENHANCE INSTABILITY/...AND THE SFC FRONTAL WAVES COMBINED WITH UPPER LEVEL DISTURBANCES WILL ALLOW FOR PERIODS OF CONVECTION. THURSDAY CONTINUES TO BE HIGHLIGHTED BY SPC INVOF THE APCHG CDFNT FOR THE WRN HALF OF MN. ONCE THE CAPPING INVERSION IS LOST OVER WRN MN...STRONG MID- AND UPPER-LEVEL JETTING WITH STEEP LAPSE RATES WITHIN A HIGHLY UNSTABLE ENVIRON /INCLUDING DEWPOINTS NEAR- OVER 70 DEGREES/ WILL PROMOTE STRONG TO SEVERE TSTMS CAPABLE OF PRODUCING LARGE HAIL AND DMGG WINDS. THE REGIME THEN TRANSITIONS TO ONE OF HEAVY RAIN OVER THE WEEKEND AS THE SFC LOW PRES SYSTEM OPENS UP AND BECOMES CAUGHT UP IN THE PROLIFIC SWLY FLOW WHILE THE NW UPPER LEVEL TROUGH OPENS TO MORE OF A TROUGH THAN CUTOFF LOW. LONG PLUME OF SLY SFC FLOW WILL AID IN BRINGING MOISTURE WELL N INTO THE UPPER MISS RIVER VALLEY REGION. MODEL QPF CONTINUES TO ADVERTISE BETWEEN 3 AND 6 INCHES OF RAIN FOR THE AREA THROUGH THE WEEKEND...BUT WITH MUCH OF IT CONVECTIVE...TRYING TO PINPOINT WHERE SUCH RAINFALL EVENTS MAY OCCUR IS HIGHLY PROBLEMATIC. STILL...HAVE KEPT HIGH-END CHC POPS GOING IN THE FCST. POPS DIMINISH FOR THE START OF NEXT WEEK AS A MORE ZONAL UPPER LEVEL PATTERN DEVELOPS...KEEPING ANY ORGANIZED LOW PRES SYSTEMS AWAY FROM THE AREA. THAT SAID...SEVERAL MID- AND UPPER-LEVEL SHORTWAVE DISTURBANCES WILL STILL BE CAPABLE OF PRODUCING ISOLD TO SCATTERED CONVECTION AS THE WARM/MOIST AIR WILL REMAIN IN PLACE THROUGH EARLY NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 610 AM CDT WED JUN 19 2013 VFR CIRRUS AND ISOLATED MID LEVEL DECK OVER WESTERN HALF OF TAF SITES SHORTLY AFTER 12Z. LOOK FOR THIS LAYER TO OVERSPREAD REMAINDER OF REGION BY ABOUT 15Z. PROXIMITY OF WARM FRONTAL BOUNDARY SHOULD BE CATALYST FOR WDLY SCT CONVECTION OVER MOST AIRPORT SITES BY MID TO LATE AFTN. LIGHT SE FLOW BECOMES MDT WITH MIXING BY 15Z ACROSS SOUTHERN MN/WESTERN WI. MUCH BETTER CHANCE FOR CONVECTION KICKS OFF KAXN AND KRWF AFT 07Z...AND OVER REMAINDER OF TAF AREA BY 10Z...AS LOW LEVEL FORCING AND JET STREAM SUPPORT INCREASES MARKEDLY. VFR CIGS AND VSBYS ANTICIPATED PRIOR TO OVERNIGHT CONVECTIVE ACTIVITY...WITH OCNL MVFR CIGS/VSBYS AS ACTIVITY WITHIN VCNTY OR OVERHEAD. KMSP... /OUTLOOK FOR KMSP/ VFR CIGS AND VSBYS THROUGH MOST OF TAF PERIOD...WITH LIGHT OCNL MODERATE SE FLOW EXPECTED. SLIGHT CHANCE FOR STRONG T-STORMS ANTICIPATED AFTER 10Z TONIGHT...IN TANDEM WITH LOW LEVEL SOUTHERLY JET STREAM. POSSIBILITY OF SHORT TERM LLWS 20/06Z-20/12Z TIME FRAME. MVFR CIGS AND VSBYS WILL BE VERY POSSIBLE ASSOCIATED WITH CONVECTION LATE. COULD BE VCSH AT KMSP UNTIL 20/20Z...UNTIL FORCING DIMINISHES. THU...VFR. CHC OF MVFR. TSRA LIKELY. SSE WINDS 10 KTS. FRI...VFR. CHC OF MVFR. TSRA LIKELY FRI NIGHT. S WINDS 10-15 KTS. SAT...VFR. CHC OF MVFR TSRA. S WINDS 5-12 KTS. SUN...VFR. CHC OF MVFR TSRA. S-SW WINDS 5-12KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...AJZ LONG TERM...JPC AVIATION...AJZ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
414 AM CDT WED JUN 19 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM CDT WED JUN 19 2013 CIRRUS SHIELD NOTED ON IR SATELLITE ENTERING FAR WESTERN MN. SHIELD IS JUST AHEAD OF DEEPENING SURFACE CYCLONE ABOVE EASTERN MONTANA. THIS FEATURE WILL BE EJECTED OUT OF 50H TROF OVER PACIFIC NW DURING THE NEXT 24 HOURS INTO WESTERN NODAK AND SOUTHERN SASKATCHEWAN. WARM FRONTAL BOUNDARY ATTACHED TO SURFACE CYCLONE WILL BE CATALYST FOR SCATTERED SHOWERS AND ISOLATE THUNDERSTORMS LATE THIS MORNING OVER FAR WESTERN CWA. USED GFS40 THETA E ADVECTION AND HRRR GUIDANCE FOR PLACEMENT AND TIMING OF DAYTIME CONVECTION OVER FA. COULD BE A FEW STRONG TO NEAR SEVERE THUNDERSTORMS THIS AFTERNOON OVER CENTRAL AND PORTIONS OF SW MN TO...AS JOULES INCREASE INTO THE 1500 TO 2500 RANGE. MODERATE 250MB DIVERGENCE COUPLETS ALSO NOTED OVER THESE AREAS ALONG WITH LI`S PLUNGING INTO THE NEGATIVE 4 TO NEGATIVE 8 CATEGORY. ONLY LIMITING FACTOR WOULD BE THICKER CLOUD DECK THEN CURRENT CIRRUS SHIELD PROGGED FOR MUCH OF THE DAYTIME HOURS. PRESENCE AND PROGRESSION OF WARM FRONTAL BOUNDARY DEEPER INTO SOUTHERN HALF OF MN TONIGHT SHOULD PORTEND SLIGHTLY ENHANCED CHANCES FOR CONVECTION...WITH QPF VALUES ALSO RISING NOTICEABLY. COULD BE A QUICK QUARTER INCH TO ONE HALF INCH OF MOISTURE GENERATE FROM CONTINUE SCT ACTIVITY DURING THE OVERNIGHT. 850MB LAPSE RATES AND LI`S WILL ALSO RISE SLIGHTLY OVERNIGHT. MODERATE SOUTHERLY LOW LEVEL JET WILL ALSO FORM BY LATE TONIGHT OVER MUCH OF MN FA ...WITH 25 TO 30KT MAGNITUDES COMMON SOUTH OF A LINE FROM ALEXANDRIA TO OWATONNA. COULD BE ADDITIONAL ISOLATED STRONG TO NEAR SEVERE T-STORMS OVER WESTERN HALF OF FA DURING THE EVENING...SWITCHING TO FAR EAST CENTRAL MN/WEST CENTRAL WI AFTER MIDNIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 410 AM CDT WED JUN 19 2013 WARM AND MOISTURE-RICH PATTERN WILL REMAIN IN PLACE FOR THE END OF THIS WEEK INTO THE START OF NEXT WEEK...INCLUDING PERIODS OF STRONG THUNDERSTORMS AND HEAVY RAIN. AN UPPER LEVEL RIDGE BUILDING OVER THE DAKOTAS AND MN/WI THRU TDA WILL SHIFT TO THE E THRU THU WHILE A LONGWAVE TROUGH DEVELOPS OVER THE NORTHWEST. SEVERAL SHORTWAVE DISTURBANCES RIDING NOT ONLY OVER TOP THE RIDGE BUT ALSO AROUND THE BASE OF THE TROUGH THU INTO FRI WILL WORK WITH AN INCOMING SFC FRONTAL SYSTEM DEVELOPING OVER THE CENTRAL-NRN PLAINS. SOLID SW FLOW WILL BRING NOT ONLY WARMER AIR /WHICH WILL RAISE H5 HEIGHTS TO ENHANCE CAPPING BUT ALSO STRONGER JETTING/ BUT ALSO MOISTURE-RICH AIR /HELPING RAISE PWATS ABOVE 1.50 INCHES AND ENHANCE INSTABILITY/...AND THE SFC FRONTAL WAVES COMBINED WITH UPPER LEVEL DISTURBANCES WILL ALLOW FOR PERIODS OF CONVECTION. THURSDAY CONTINUES TO BE HIGHLIGHTED BY SPC INVOF THE APCHG CDFNT FOR THE WRN HALF OF MN. ONCE THE CAPPING INVERSION IS LOST OVER WRN MN...STRONG MID- AND UPPER-LEVEL JETTING WITH STEEP LAPSE RATES WITHIN A HIGHLY UNSTABLE ENVIRON /INCLUDING DEWPOINTS NEAR- OVER 70 DEGREES/ WILL PROMOTE STRONG TO SEVERE TSTMS CAPABLE OF PRODUCING LARGE HAIL AND DMGG WINDS. THE REGIME THEN TRANSITIONS TO ONE OF HEAVY RAIN OVER THE WEEKEND AS THE SFC LOW PRES SYSTEM OPENS UP AND BECOMES CAUGHT UP IN THE PROLIFIC SWLY FLOW WHILE THE NW UPPER LEVEL TROUGH OPENS TO MORE OF A TROUGH THAN CUTOFF LOW. LONG PLUME OF SLY SFC FLOW WILL AID IN BRINGING MOISTURE WELL N INTO THE UPPER MISS RIVER VALLEY REGION. MODEL QPF CONTINUES TO ADVERTISE BETWEEN 3 AND 6 INCHES OF RAIN FOR THE AREA THROUGH THE WEEKEND...BUT WITH MUCH OF IT CONVECTIVE...TRYING TO PINPOINT WHERE SUCH RAINFALL EVENTS MAY OCCUR IS HIGHLY PROBLEMATIC. STILL...HAVE KEPT HIGH-END CHC POPS GOING IN THE FCST. POPS DIMINISH FOR THE START OF NEXT WEEK AS A MORE ZONAL UPPER LEVEL PATTERN DEVELOPS...KEEPING ANY ORGANIZED LOW PRES SYSTEMS AWAY FROM THE AREA. THAT SAID...SEVERAL MID- AND UPPER-LEVEL SHORTWAVE DISTURBANCES WILL STILL BE CAPABLE OF PRODUCING ISOLD TO SCATTERED CONVECTION AS THE WARM/MOIST AIR WILL REMAIN IN PLACE THROUGH EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1137 PM CDT TUE JUN 18 2013 VFR CONDITIONS TONIGHT AND FOR MOST OF THE AREA WEDNESDAY. POTENTIAL FOR FOG TONIGHT HAS DIMINISHED SUCH THAT IT HAS BEEN REMOVED FROM THE TAFS. A FEW THUNDERSTORMS MAY DEVELOP WEDNESDAY AFTERNOON ACROSS MN...BUT THEY SHOULD REMAIN FAIRLY ISOLATED AND SHORT-LIVED SO WAS NOT CONFIDENT ENOUGH TO INCLUDE MENTION IN ANY TAFS. IF IT DOES HIT A TAF SITE...BRIEF MVFR CONDITIONS WOULD BE LIKELY. WINDS WILL VEER SOUTHERLY AND STRENGTHEN WEDNESDAY...BEFORE DIMINISHING AND BACKING SOUTHEASTERLY DURING THE EVENING. KMSP...VFR EXPECTED THROUGH THE PERIOD. LITTLE WX IMPACT EXPECTED THROUGH MOST OF WED...BUT THERE IS AN OUTSIDE CHANCE OF A LATE DAY STORM. WIND WILL INCREASE SOUTHERLY AND COULD GUST TO NEARLY 20 KT WEDNESDAY. /OUTLOOK FOR KMSP/ THU...VFR. CHC OF MVFR. TSRA LIKELY. SSE WINDS 10 KTS. FRI...VFR. CHC OF MVFR TSRA. S WINDS 10-15 KTS. SAT...VFR. CHC OF MVFR TSRA. S WINDS 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...AJZ LONG TERM...JPC AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1036 AM CDT WED JUN 19 2013 .UPDATE... A WEAK AND STALLED FRONTAL BOUNDARY WILL BE THE MAIN FOCUS THIS AFTERNOON FOR SOME SHOWERS/THUNDERSTORM ACTIVITY. THIS BOUNDARY WILL SLOWLY DRIFT TO THE SOUTH THROUGHOUT THE DAY. WATER VAPOR ANALYSIS INDICATES A S/WV AND TROUGH AXIS MOVING THROUGH THE ARKLAMISS DELTA. THE ENHANCED SYNOPTIC LIFT AND AIDED WITH CONVERGENCE ALONG THE STALLED FRONTAL BOUNDARY WILL AID IN SHOWER/THUNDERSTORM DEVELOPMENT THIS AFTERNOON TO EVENING. WENT CLOSE TO MAV POPS AS HRRR WAS INDICATING MOST ACTIVITY ALONG AND S OF THE I-20 CORRIDOR...MAINLY IN THE SE...AND WEAKENING AFTER 00Z. WEAK LAPSE RATES AND VERTICAL TOTALS AROUND 25-26C WILL AID IN SOME THUNDERSTORM DEVELOPMENT BUT NOT EXPECTING MUCH IN THE WAY OF STRONG STORMS. TEMPS TODAY LOOK TO BE RUNNING ON TRACK AND DID NOT MODIFY HIGH TEMPS THIS AFTERNOON. ONLY MODIFIED HOURLY TEMPS/DEWPOINTS ACCORDING TO CURRENT TRENDS. ALSO MODIFIED CLOUD COVER GRIDS TO ONLY SLIGHTLY SPEED UP SOUTHWARD PROGRESSION OF CLOUD COVER. REST OF THE FORECAST IS ON TRACK. /DC/ && .AVIATION...MVFR CIG AT A FEW LOCALES WILL TREND VFR BY LATE MORNING W/VFR CONDS PERSISTING THRU THE REMAINDER OF THE DAY. NUMEROUS SHRA WILL IMPACT SE MS OVER THE NEXT FEW HRS BEFORE MORE ISOLD ACTIVITY TAKES SHAPE THIS AFTN. ELSEWHERE ISOLD SHRA WILL BE PSBL THIS MORNING DECLINING IN COVERAGE THRU THE AFTN. MVFR/IFR CIG AND PSBLY VSBY CAN BE XPCTD AT HBG/MEI AND PSBLY JAN/HKS TOMORROW MORNING 10-14Z. /BK/ && .PREV DISCUSSION... /ISSUED 340 AM CDT WED JUN 19 2013/ SHORT TERM...THE FOCUS OF THE FORECAST WILL CONTINUE TO REVOLVE AROUND PRECIP CHANCES...ESPECIALLY FOR TODAY AND THU...BUT THESE CHANCES WILL OVERALL LESS THAN WHAT THE AREA HAS SEEN THE PAST COUPLE DAYS. ONE OF THE KEY FEATURES THAT WILL INFLUENCE OUR WEATHER IS THE STALLED WEAK SFC FRONT ACROSS THE AREA. THIS BOUNDARY HAS BECOME BROAD/DIFFUSE...BUT IS GENERALLY SITUATED FROM TUP TO MLU. WHILE IT WOULD SEEM THAT AREAS ALONG AND SOUTH OF SAID BOUNDARY WOULD HAVE THE BEST PRECIP POTENTIAL TODAY...THIS NOT TRULY THE CASE. THE REASON IS THAT SOME DRIER AIR IN THE MID LEVELS IS PRESENT FOR AREAS JUST NORTH OF I-20. THIS IS IN PART TO NORTHERLY MID LEVEL FLOW DRAWING SOUTHWARD THAT DRIER AIR AS THE S/WV PASSED ACROSS THE SOUTHERN PARTS OF THE FORECAST AREA LAST EVENING. WITH ALL OF THIS...AREAS ALONG AND SOUTH OF I-20 WILL HAVE THE DEEPEST MOISTURE TO WORK WITH TODAY ALONG WITH SOME LOW LEVEL FOCUS FROM THE STALLED SFC BOUNDARY. ADDITIONALLY...WATER VAPOR IMAGERY SHOWS THE MID/UPPER TROUGH AXIS QUITE WELL AND IT IS SITUATED JUST TO OUR WEST. THIS FEATURE SHOULD ASSIST LIFT (ESP THIS MORNING) AND GENERATE PRECIP ACROSS THE SOUTHERN HALF OF THE AREA. THINKING THAT THE AIRMASS HAS BEEN WORKED OVER QUIET A BIT...OVER ALL LESS STORM COVERAGE IS EXPECTED. THUS...FOLLOWING THE 20-40% POPS FROM THE GFS SEEM VALID. WITH ANOTHER EARLY START TO ACTIVITY...WILL TREND POPS/WX DOWN FOR THE LATE AFTERNOON. LIKE YESTERDAY...TEMPS WILL BE HELD IN CHECK THANKS TO CLOUDS AND THE EARLY START TO PRECIP. GFS GUIDANCE INDICATES THIS WELL AND HAVE FOLLOWED. TONIGHT WILL BE GENERALLY QUIET WITH CLEARINGS SKIES. TEMPS WILL BE A BIT COOLER THAN WHAT WE HAVE SEE WITH UPPER 60S EXPECTED. THURSDAY WILL BE A TRICKIER FORECAST AS THE PREV MENTIONED SFC BOUNDARY WILL STILL BE IN THE GENERAL AREA BUT LIKELY SITUATED/ORIENTED IN A DIFFERENT MANNER. DEEP MOISTURE WILL BE OVERALL LOWER AREAWIDE WITH HIGHER MOISTURE CONTENT GENERALLY ACROSS THE SW/S HALF. WHAT MAKES THE FORECAST TRICKY IS THE PRESENCE OF A DISTINCT S/WV DROPPING SE. ASSOCIATED WITH THIS FEATURE WILL BE COOLER TEMPS IN THE MID LEVEL AND ALOFT. THE MID/UPPER LEVEL JET WILL ALSO BE SITUATED IN A WAY THAT SUPPORTS UPWARD MOTION. EVEN AS THESE FAVORABLE FEATURES EXIST...MODEL DATA IS NOT SHOWING MUCH DEVELOPMENT. I CAN`T ARGUE THAT THERE WILL BE LESS OVERALL POTENTIAL...BUT FEEL THAT ENOUGH INGREDIENTS WILL EXIST THAT ISOLATED STORMS WILL BE POSSIBLE DURING THE AFTERNOON. WITH THAT...HAVE INCREASED POPS FROM 10% TO 20% AND MENTIONED SLIGHT CHANCE FOR AFTERNOON ACTIVITY. AT THIS TIME...I WILL NOT MENTION ANY POSSIBILITY FOR STRONG STORMS...BUT THIS WILL HAVE TO BE MONITORED AS THE COOLER TEMPS ALOFT WILL LEAD TO BETTER LAPSE RATES AND A BIT HIGHER INSTABILITY AS SFC TEMPS WILL BE 2-4 DEGREES WARMER. /CME/ LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...AN UPPER RIDGE WILL TRY BUILDING INTO THE WESTERN HALF OF THE FORECAST AREA FRIDAY INTO THE WEEKEND AS AN UPPER TROUGH PULLS OFF TO THE NORTHEAST AND UP THE EAST COAST. AS THIS HAPPENS...THE TROUGH WILL LEAVE BEHIND A PIECE OF ENERGY THAT`LL SET THE STAGE FOR SOME ISOLATED TO SCATTERED AFTERNOON AND EARLY EVENING SHOWERS AND STORMS OVER MAINLY EAST AND SOUTHEAST MISSISSIPPI THROUGH THE WEEKEND. RAIN CHANCES LOOK TO WANE HEADING INTO THE NEW WORK WEEK AS THE UPPER RIDGE BUILDS FURTHER EAST INTO THE CWA. OTHERWISE...LOOK FOR CONTINUED HOT AND HUMID CONDITIONS THROUGH THE FORECAST PERIOD. GUIDANCE SUGGESTED HIGHS AND LOWS LOOK REASONABLE THIS MORNING. HIGHS EACH AFTERNOON WILL RANGE IN THE LOW TO MID 90S...WHILE LOWS EACH NIGHT GENERALLY RANGE FROM THE UPPER 60S TO LOWER 70S. /19/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 89 66 91 69 / 25 9 17 6 MERIDIAN 87 64 91 68 / 27 12 15 12 VICKSBURG 88 64 91 68 / 21 7 17 4 HATTIESBURG 87 68 92 69 / 40 24 23 12 NATCHEZ 87 67 90 68 / 34 9 23 6 GREENVILLE 90 68 94 70 / 6 4 7 3 GREENWOOD 90 65 93 68 / 7 4 5 5 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ DC/BK/CME/19
AREA FORECAST DISCUSSION
NWS BILLINGS MT
922 PM MDT THU JUN 20 2013 .UPDATE... SHOWER ACTIVITY IN CENTRAL PARTS HAS DIMINISHED WITH PASSAGE OF WEAK SHORTWAVE...BUT MORE ARE ON THE WAY AS LOW LEVEL JET FORCING/MOISTURE INCREASE THROUGH THE NIGHT. DEWPTS ALONG THE DAKOTAS BORDER ARE RESPONDING WITH A STEADY RISE OVER THE PAST FEW HOURS. CONVERGENT BAND OF SHOWERS LIFTING THROUGH EASTERN WY AS WELL. SO OVERALL EXPECT AN INCREASE IN SHOWERS WITH ISOLD TSTMS ACROSS OUR EAST LATER TONIGHT. NOT MUCH GOING IN OUR WEST AND HAVE LOWERED EVENING POPS. COULD ALSO BE SOME STRATUS TO CONTEND WITH BY EARLY TOMORROW PER THE MOISTURE ADVECTION...ESPECIALLY IN OUR EAST AND UPSLOPE AREAS. ONE OTHER NOTE...DRY AIR AND LIGHT WINDS WILL ALLOW FOR A CHILLY NIGHT IN OUR WEST AT SUCH PLACES AS LIVINGSTON AND HARLOWTON. EXPECT MID TO UPPER 30S FOR LOWS IN THESE SPOTS. JKL PREVIOUS DISCUSSION ISSUED 623 PM... INTERESTING WX NIGHT. ASCENT AND MID LEVEL MOISTURE ARE BEGINNING TO INCREASE WITH SHORTWAVE OUT OF THE S/SW. DESPITE SOME VERY DRY LOW LEVELS...SOME SHOWERS WITH A FEW LIGHTNING STRIKES HAVE DEVELOPED IN AN AREA FROM NEAR SHERIDAN TO HYSHAM. RAP ANALYSIS SHOWS BACKING MID LEVEL WINDS AND A WEAK CIRCULATION FORMING IN OUR SOUTH CENTRAL PARTS. CONVECTION THAT IS DEVELOPING IS CERTAINLY QUITE ELEVATED AND APPEARS TO BE TIED TO FORCING NEAR 700MB. THIS IS A FEW HOURS FASTER THAN ANY MODELS SUGGESTED. ONSET OF EASTERLY LOW LEVEL JET WILL PROVIDE MORE SIGNIFICANT MOISTURE ADVECTION AND STRONGER FORCING AFTER SUNSET...SO EXPECT SHOWERS AND EMBEDDED TSTMS TO INCREASE IN COVERAGE ACROSS OUR EAST HALF. LOW LEVEL MOISTURE ADVECTION ALONG WITH PERSISTENT ISENTROPIC ASCENT AND DEEPENING EASTERLY WINDS SUGGEST TOMORROW MAY BE A WETTER DAY ACROSS OUR CWA THAN MODELS WERE SUGGESTING...E.G. THE GFS SEEMS TOO LIGHT WITH ITS QPF. SO HAVE RAISED POPS TO HIGHER CHANCE WEST AND CENTRAL PARTS ON FRIDAY...KEEPING LIKELIES IN THE MORE DEEPLY MOIST AND UNSTABLE AIRMASS TO OUR EAST. OTHERWISE FOR THIS EVENING...ACTIVITY ASSOCIATED WITH UPPER LOW AND COLDER AIR ALOFT TO OUR WEST IS MOSTLY STAYING TO OUR WEST IN CENTRAL/WESTERN MT...SO HAVE REDUCED POPS TO ISOLD FOR LIVINGSTON AND OUR WESTERN FOOTHILLS. JKL && .SHORT TERM...VALID FOR FRI AND SAT... WEATHER WILL BECOME MORE UNSETTLED WITH TIME DURING THE SHORT- TERM PERIOD AS PACIFIC UPPER LOW OVER THE NW U.S. MOVES E. SHOWERS HAD DEVELOPED OVER W MT THIS AFTERNOON PER RADAR IMAGERY. CU FIELDS WERE EVIDENT OVER THE CENTRAL AND WESTERN FORECAST AREA PER VISIBLE SATELLITE IMAGERY. VORTICITY ROTATING AROUND THE UPPER LOW WILL COMBINE WITH JET DIVERGENCE...A DEVELOPING LOW-LEVEL JET AND ISENTROPIC LIFT TO BRING SHOWERS AND A FEW THUNDERSTORMS TO THE AREA TONIGHT. PRECIPITATION CHANCES WILL INCREASE OVER THE SE AFTER 06Z TONIGHT DUE TO THE LOW-LEVEL JET AND ISENTROPIC LIFT. MOISTURE TRANSPORT WAS ALSO FORECAST TO INCREASE INTO THIS AREA. THE ISENTROPIC LIFT WILL PERSIST OVER THE SE FRI AND FRI NIGHT SUPPORTING A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS. HIGH CAPES AND SHEAR OVER SE MT WILL SUPPORT POSSIBLE STRONG THUNDERSTORMS FRI AFTERNOON AND EVENING. JET DIVERGENCE WILL INCREASE OVER THE REGION ON SAT AS THE RIGHT ENTRANCE REGION OF A JET IN THE E SIDE OF THE LOW MOVES OVER THE AREA. SHORTWAVES WILL CONTINUE TO MOVE THROUGH THE REGION AS WELL. ISENTROPIC LIFT WILL ALSO INCREASE OVER THE AREA OVER THE FRONTAL BOUNDARY TO THE SE OF THE REGION. PRECIPITABLE WATERS CLIMB TO AROUND AN INCH OVER THE SE ON SAT. INCREASED POPS ACROSS THE AREA SAT AND SAT EVENING. PRECIPITATION WILL BEGIN TO SHIFT E LATE SAT NIGHT. MODELS DID DIFFER ON PLACEMENT OF PRECIPITATION OVER MUCH OF THE PERIOD...SO WILL NEED TO WATCH FOR BETTER AGREEMENT WITH TIME. LEANED MORE ON THE GFS FOR POPS THAN THE WRF. ALSO LOWERED TEMPERATURES ON SAT BASED ON GFS. WILL NEED TO KEEP AN EYE ON EXPECTED PRECIPITATION AMOUNTS AS SAT GETS CLOSER...IN CASE OF FLASH FLOOD POTENTIAL FOR BURN SCAR AREAS...ESPECIALLY IN SE MT. ARTHUR .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... MODELS REMAIN IN FAIRLY GOOD AGREEMENT THROUGH THE EXTENDED WITH RIDGING BEGINNING TO BUILD BY MID NEXT WEEK. HAVE ONLY MADE SOME MINOR CHANGES TO THE GRIDS AS CURRENT FORECAST LOOKS ON TRACK. LARGE UPPER LOW ACROSS SOUTHERN CANADA WILL CONTINUE TO SLOWLY SHIFT EAST SUNDAY TAKING PRECIP CHANCES EASTWARD INTO THE DAKOTAS. THERE WILL STILL REMAIN A SLIGHT CHANCE FOR A SHOWER/THUNDERSTORM ACROSS OUR FAR EASTERN ZONES TOWARD THE DAKOTA BORDERS SUNDAY AFTERNOON. BROAD SOUTHWEST FLOW ALOFT WILL BE OVER THE FORECAST AREA MONDAY AND TUESDAY. A WEAK DISTURBANCE WILL MOVE ACROSS THE AREA MONDAY AFTERNOON THROUGH TUESDAY BRINGING A SLIGHT CHANCE FOR A SHOWER/THUNDERSTORM. HIGH PRESSURE RIDGING BEGINS TO BUILD WEDNESDAY THROUGH THE END OF THE WEEK ALLOWING FOR DRY CONDITIONS TO PREVAIL BUT CAN`T RULE OUT AN ISOLATED THUNDERSTORM. MODELS ARE INDICATING THE POSSIBILITY OF HOT TEMPERATURES BY THE END OF NEXT WEEK INTO NEXT WEEKEND. WILL CONTINUE WITH LOWER TO MIDDLE 80S FOR HIGHS FOR THAT TIME FRAME BUT TEMPERATURES MAY BE QUIET A BIT WARMER. HOOLEY && .AVIATION... A DISTURBANCE WILL MOVE INTO THE AREA FROM THE SOUTHWEST OVERNIGHT PRODUCING SCATTERED SHOWERS AND A FEW THUNDERSTORMS...MAINLY ALONG AND SOUTH OF A MILES CITY TO LIVINGSTON LINE. MVFR CONDITIONS CAN BE EXPECTED NEAR SHOWERS AND THUNDERSTORMS. LOW LEVEL WINDS WILL TURN EASTERLY OVERNIGHT MOVING PLAINS MOISTURE BACK INTO THE AREA...RESULTING IN SCATTERED STRATUS DEVELOPMENT ESPECIALLY ALONG EASTERN AND NORTHERN FOOTHILLS LOCATIONS INCLUDING KSHR. AN OVER RUNNING PATTERN ON FRIDAY WILL KEEP MOSTLY CLOUDY CONDITIONS OVER THE REGION WITH OCCASIONAL MVFR CEILINGS AND SCATTERED SHOWERS. A FEW EMBEDDED THUNDERSTORMS WILL ALSO BE POSSIBLE FRIDAY. EXPECT MOUNTAIN OBSCURATION TO DEVELOP LATE TONIGHT AND CONTINUE THROUGH FRIDAY FOR AREA MOUNTAINS. CHAMBERS && .PRELIMINARY POINT TEMP/POPS... FRI SAT SUN MON TUE WED THU ----------------------------------------------------------- BIL 051/070 052/066 049/078 054/083 058/084 057/083 057/084 25/T 36/T 61/B 11/B 22/T 21/B 00/U LVM 036/069 042/065 044/079 046/083 051/083 052/086 051/087 25/T 36/T 51/B 12/T 22/T 21/B 11/U HDN 052/073 050/070 048/078 052/083 054/085 056/084 058/085 44/T 37/T 61/B 11/B 22/T 21/U 00/U MLS 055/076 056/071 053/080 056/084 059/085 059/086 057/086 45/T 57/T 71/B 11/U 22/T 21/U 11/U 4BQ 052/075 054/071 051/079 054/085 057/086 057/087 058/088 65/T 58/T 71/B 11/U 22/T 21/U 11/U BHK 054/075 055/069 052/076 054/085 059/084 060/086 057/082 66/T 68/T 82/T 12/T 22/T 21/U 11/U SHR 048/075 049/067 045/076 049/082 052/084 051/085 052/084 54/T 37/T 61/B 11/B 22/T 21/B 00/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
910 PM MDT THU JUN 20 2013 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY... SENT AN UPDATE TONIGHT TO FINE TUNE THE IMMEDIATE SHORT TERM GRIDS CLOSELY FOLLOWING SATELLITE...RADAR...AND NEWEST MODEL DATA. EXPECTING A QUIET NIGHT. BMICKELSON PREVIOUS SHORT TERM DISCUSSION...A FEW THUNDERSTORMS ARE INITIATING OVER SHERIDAN COUNTY THIS AFTERNOON. CUMULUS DEVELOPMENT IS ALSO TAKING PLACE ACROSS SOME OF THE WESTERN ZONES AND SO PLACED THE CWA BROADLY INTO SLIGHT CHANCE POPS. THE LATEST HRRR MODEL RUN SHOWS CONVECTION INITIATION ACROSS PHILLIPS COUNTY THIS AFTERNOON AND SO HAVE SOMEWHAT HIGHER POPS THERE. WITH EXCEPTION OF A FEW STORMS...STILL EXPECTING A MUCH QUIETER EVENING AS COMPARED TO LAST NIGHT. FRIDAY AND SATURDAY...NEXT UPPER LEVEL SHORTWAVE ROTATES AROUND UPPER LEVEL LOW. THIS WILL COMBINE WITH AVAILABLE MOISTURE TO PROVIDE A DECENT CHANCE OF SHOWERS AND THUNDERSTORMS. MODEL DISAGREEMENT EXISTS THOUGH WITH THE GFS KEEPING THE CWA DRY AND THE ECMWF SHOWING SOME OF THE BEST POTENTIAL. LEANED WITH THE ECMWF SOLUTION FOR NOW AS IT SEEMS TO ALSO HAVE SUPPORT FROM THE LATEST NAM SOLUTION. BEST VERTICAL ASCENT ACROSS NORTHEAST MONTANA LOOKS TO BE SATURDAY AFTERNOON AND EVENING OUT AHEAD OF THE SHORTWAVE COINCIDENT WITH THE BEST PVA. NAM BUFKIT SOUNDINGS SHOWS PRECIPITABLE WATER VALUES GENERALLY BETWEEN A HALF OF AN INCH AND AN INCH. NOT SEEING MUCH IN TERMS OF CONVECTIVE PARAMETERS HOWEVER SO WITH ANY CONVECTION THAT INITIATES...STRONG STORMS SHOULD BE LIMITED. HOWEVER...LOCALLY HEAVY RAINFALL CERTAINLY IS A POSSIBILITY...ESPECIALLY DUE TO LOW LEVEL SOUTHEASTERLY FLOW BRINGING IN MOISTURE FROM THE GULF OF MEXICO. MALIAWCO .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY... GOING FORECAST LOOKED GOOD TODAY AND ONLY A TWEAK TO A TEMPERATURE GRID ON TUESDAY NIGHT WAS MADE. JAMBA PREVIOUS DISCUSSION... SATURDAY NIGHT...A STRONG SHORTWAVE ON SOUTH SIDE OF UPPER LOW IN ALBERTA AND SASKATCHEWAN ROTATES THROUGH EASTERN MONTANA. EXPECT SHOWERS AND THUNDERSTORMS TO OCCUR OVER MOST OF THE AREA AS THIS WAVE MOVES THROUGH. THE PRECIP COULD LINGER INTO SUNDAY ESPECIALLY IN THE NORTHEAST HALF OF THE REGION AS THE WAVE MOVES TO THE EAST AND THE UPPER LOW REMAINS TO THE NORTH. INCREASED POPS FOR SATURDAY EVENING TO LIKELY/CATEGORICAL AND MAINTAINED LIKELY POPS IN THE EASTERN HALF AFTER MIDNIGHT SATURDAY NIGHT. SHORTWAVE RIDGE WILL BRING A BREAK IN THE STORMS SUNDAY NIGHT AND MONDAY MORNING. FLOW ALOFT TURNS TO THE SOUTHWEST BY MONDAY AFTERNOON WITH UPPER LOW OFF THE PACIFIC NORTHWEST COAST. A SHORTWAVE TROUGH IN THE SOUTHWEST FLOW ALOFT WILL BRING A CHANCE OF THUNDERSTORMS STARTING MONDAY AFTERNOON AND LASTING INTO TUESDAY EVENING. A STRONG RIDGE BUILDS OVER THE WESTERN U.S. STARTING ON WEDNESDAY WITH DRY WEATHER AND WARMING TEMPERATURES. FORRESTER && .AVIATION... VFR. TONIGHT GENERALLY LIGHT WINDS ACROSS THE REGION WITH A FEW REMAINING SHOWERS DISSIPATING BY 03Z. FAIR OVERNIGHT AREA WIDE. AFTER 20Z LOOK FOR SHOWERS AND A FEW THUNDERSTORMS TO BEING TO DEVELOP AROUND THE REGION. PROTON && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
623 PM MDT THU JUN 20 2013 .UPDATE... INTERESTING WX NIGHT. ASCENT AND MID LEVEL MOISTURE ARE BEGINNING TO INCREASE WITH SHORTWAVE OUT OF THE S/SW. DESPITE SOME VERY DRY LOW LEVELS...SOME SHOWERS WITH A FEW LIGHTNING STRIKES HAVE DEVELOPED IN AN AREA FROM NEAR SHERIDAN TO HYSHAM. RAP ANALYSIS SHOWS BACKING MID LEVEL WINDS AND A WEAK CIRCULATION FORMING IN OUR SOUTH CENTRAL PARTS. CONVECTION THAT IS DEVELOPING IS CERTAINLY QUITE ELEVATED AND APPEARS TO BE TIED TO FORCING NEAR 700MB. THIS IS A FEW HOURS FASTER THAN ANY MODELS SUGGESTED. ONSET OF EASTERLY LOW LEVEL JET WILL PROVIDE MORE SIGNIFICANT MOISTURE ADVECTION AND STRONGER FORCING AFTER SUNSET...SO EXPECT SHOWERS AND EMBEDDED TSTMS TO INCREASE IN COVERAGE ACROSS OUR EAST HALF. LOW LEVEL MOISTURE ADVECTION ALONG WITH PERSISTENT ISENTROPIC ASCENT AND DEEPENING EASTERLY WINDS SUGGEST TOMORROW MAY BE A WETTER DAY ACROSS OUR CWA THAN MODELS WERE SUGGESTING...E.G. THE GFS SEEMS TOO LIGHT WITH ITS QPF. SO HAVE RAISED POPS TO HIGHER CHANCE WEST AND CENTRAL PARTS ON FRIDAY...KEEPING LIKELIES IN THE MORE DEEPLY MOIST AND UNSTABLE AIRMASS TO OUR EAST. OTHERWISE FOR THIS EVENING...ACTIVITY ASSOCIATED WITH UPPER LOW AND COLDER AIR ALOFT TO OUR WEST IS MOSTLY STAYING TO OUR WEST IN CENTRAL/WESTERN MT...SO HAVE REDUCED POPS TO ISOLD FOR LIVINGSTON AND OUR WESTERN FOOTHILLS. JKL && .SHORT TERM...VALID FOR FRI AND SAT... WEATHER WILL BECOME MORE UNSETTLED WITH TIME DURING THE SHORT- TERM PERIOD AS PACIFIC UPPER LOW OVER THE NW U.S. MOVES E. SHOWERS HAD DEVELOPED OVER W MT THIS AFTERNOON PER RADAR IMAGERY. CU FIELDS WERE EVIDENT OVER THE CENTRAL AND WESTERN FORECAST AREA PER VISIBLE SATELLITE IMAGERY. VORTICITY ROTATING AROUND THE UPPER LOW WILL COMBINE WITH JET DIVERGENCE...A DEVELOPING LOW-LEVEL JET AND ISENTROPIC LIFT TO BRING SHOWERS AND A FEW THUNDERSTORMS TO THE AREA TONIGHT. PRECIPITATION CHANCES WILL INCREASE OVER THE SE AFTER 06Z TONIGHT DUE TO THE LOW-LEVEL JET AND ISENTROPIC LIFT. MOISTURE TRANSPORT WAS ALSO FORECAST TO INCREASE INTO THIS AREA. THE ISENTROPIC LIFT WILL PERSIST OVER THE SE FRI AND FRI NIGHT SUPPORTING A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS. HIGH CAPES AND SHEAR OVER SE MT WILL SUPPORT POSSIBLE STRONG THUNDERSTORMS FRI AFTERNOON AND EVENING. JET DIVERGENCE WILL INCREASE OVER THE REGION ON SAT AS THE RIGHT ENTRANCE REGION OF A JET IN THE E SIDE OF THE LOW MOVES OVER THE AREA. SHORTWAVES WILL CONTINUE TO MOVE THROUGH THE REGION AS WELL. ISENTROPIC LIFT WILL ALSO INCREASE OVER THE AREA OVER THE FRONTAL BOUNDARY TO THE SE OF THE REGION. PRECIPITABLE WATERS CLIMB TO AROUND AN INCH OVER THE SE ON SAT. INCREASED POPS ACROSS THE AREA SAT AND SAT EVENING. PRECIPITATION WILL BEGIN TO SHIFT E LATE SAT NIGHT. MODELS DID DIFFER ON PLACEMENT OF PRECIPITATION OVER MUCH OF THE PERIOD...SO WILL NEED TO WATCH FOR BETTER AGREEMENT WITH TIME. LEANED MORE ON THE GFS FOR POPS THAN THE WRF. ALSO LOWERED TEMPERATURES ON SAT BASED ON GFS. WILL NEED TO KEEP AN EYE ON EXPECTED PRECIPITATION AMOUNTS AS SAT GETS CLOSER...IN CASE OF FLASH FLOOD POTENTIAL FOR BURN SCAR AREAS...ESPECIALLY IN SE MT. ARTHUR .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... MODELS REMAIN IN FAIRLY GOOD AGREEMENT THROUGH THE EXTENDED WITH RIDGING BEGINNING TO BUILD BY MID NEXT WEEK. HAVE ONLY MADE SOME MINOR CHANGES TO THE GRIDS AS CURRENT FORECAST LOOKS ON TRACK. LARGE UPPER LOW ACROSS SOUTHERN CANADA WILL CONTINUE TO SLOWLY SHIFT EAST SUNDAY TAKING PRECIP CHANCES EASTWARD INTO THE DAKOTAS. THERE WILL STILL REMAIN A SLIGHT CHANCE FOR A SHOWER/THUNDERSTORM ACROSS OUR FAR EASTERN ZONES TOWARD THE DAKOTA BORDERS SUNDAY AFTERNOON. BROAD SOUTHWEST FLOW ALOFT WILL BE OVER THE FORECAST AREA MONDAY AND TUESDAY. A WEAK DISTURBANCE WILL MOVE ACROSS THE AREA MONDAY AFTERNOON THROUGH TUESDAY BRINGING A SLIGHT CHANCE FOR A SHOWER/THUNDERSTORM. HIGH PRESSURE RIDGING BEGINS TO BUILD WEDNESDAY THROUGH THE END OF THE WEEK ALLOWING FOR DRY CONDITIONS TO PREVAIL BUT CAN`T RULE OUT AN ISOLATED THUNDERSTORM. MODELS ARE INDICATING THE POSSIBILITY OF HOT TEMPERATURES BY THE END OF NEXT WEEK INTO NEXT WEEKEND. WILL CONTINUE WITH LOWER TO MIDDLE 80S FOR HIGHS FOR THAT TIME FRAME BUT TEMPERATURES MAY BE QUIET A BIT WARMER. HOOLEY && .AVIATION... SKIES WILL BE CLEAR TO PARTLY CLOUDY ACROSS THE FORECAST AREA THIS EVENING AND THROUGH THE OVERNIGHT HOURS. ANOTHER DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA BRINGING A SLIGHT CHANCE FOR A SHOWER AND THUNDERSTORM. THE BEST CHANCES WILL BE ALONG AND EAST OF A KMLS- KSHR LINE AFTER 06Z. VFR CONDITIONS WILL PREVAIL BUT EXPECT MVFR TO IFR CONDITIONS IN AND NEAR THUNDERSTORM ACTIVITY. THE MOUNTAINS WILL CONTINUE TO BE OBSCURED AT TIMES. HOOLEY && .PRELIMINARY POINT TEMP/POPS... FRI SAT SUN MON TUE WED THU ----------------------------------------------------------- BIL 051/073 052/066 049/078 054/083 058/084 057/083 057/084 25/T 36/T 61/B 11/B 22/T 21/B 00/U LVM 041/072 042/065 044/079 046/083 051/083 052/086 051/087 25/T 36/T 51/B 12/T 22/T 21/B 11/U HDN 052/074 050/070 048/078 052/083 054/085 056/084 058/085 44/T 37/T 61/B 11/B 22/T 21/U 00/U MLS 055/076 056/071 053/080 056/084 059/085 059/086 057/086 45/T 57/T 71/B 11/U 22/T 21/U 11/U 4BQ 052/075 054/071 051/079 054/085 057/086 057/087 058/088 65/T 58/T 71/B 11/U 22/T 21/U 11/U BHK 054/075 055/069 052/076 054/085 059/084 060/086 057/082 66/T 68/T 82/T 12/T 22/T 21/U 11/U SHR 048/075 049/067 045/076 049/082 052/084 051/085 052/084 54/T 37/T 61/B 11/B 22/T 21/B 00/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
913 AM MDT WED JUN 19 2013 .UPDATE... SEVERE THUNDERSTORMS WILL BE POSSIBLE N OF A KLVM TO KBIL LINE THIS AFTERNOON AND EVENING. IF CONVECTION INHIBITION CAN BE OVERCOME OVER SE MT...SEVERE WEATHER WILL BE POSSIBLE THERE TOO. PLENTY OF FACTORS WILL CONTRIBUTE TO LIFT OVER THE AREA THROUGH TONIGHT. DIFLUENT FLOW WAS EVIDENT ON WATER VAPOR IMAGERY THIS MORNING. UPPER LOW WAS ALSO SEEN ON IMAGERY NEGATIVELY TILTING INTO THE PACIFIC NW. A STRONG 500 MB FLOW W OF THE AREA AT 12Z WILL MOVE E DURING THE DAY BRINGING INCREASING SHEAR. SHORTWAVE ENERGY WILL ROTATE INTO THE AREA TODAY THROUGH TONIGHT...BRINGING Q-VECTOR CONVERGENCE. A LOW-LEVEL JET WILL STRENGTHEN OVER THE EASTERN ZONES TODAY AS WELL. MORE LIFT WILL BE PROVIDED BY STRONG JET DIVERGENCE OVER THE WESTERN ZONES TONIGHT. THERE WILL NOT BE A LOT OF MOISTURE TO WORK WITH THROUGH THIS EVENING AS MOISTURE TRANSPORT VECTORS SHOWED THE BEST MOISTURE BEING TRANSPORTED FROM THE CENTRAL PLAINS INTO THE NE PART OF MT. REMAINDER OF THE AREA WILL RECEIVE MOISTURE FROM WY/SE ID/UT WHERE PRECIPITABLE WATERS WERE AROUND /0.30/ INCHES WHICH WAS DRY AIR. AS FOR INSTABILITY...HIGH CAPES AND HELICITIES WILL BE E OF KBIL THIS AFTERNOON AND EVENING SO STORMS THAT DO FORM WILL NEED TO MONITORED CLOSELY FOR SEVERE POTENTIAL. STORMS THAT FORM ALONG THE NORTHERN TIER WILL BE IN A HIGH CAPE/INCREASING SHEAR ENVIRONMENT AND WILL NEED TO BE WATCHED AS WELL. THE AREAS WHERE SEVERE STORMS AND DRY THUNDERSTORMS WERE MENTIONED WERE IN GOOD SHAPE PER THE ABOVE. NOTE THAT THE 12Z HRRR HAS NOTHING DEVELOPING UNTIL 22Z THIS AFTERNOON. SEE NO NEED TO CHANGE GOING FORECAST. THE SYSTEM/S COLD FRONT WILL MOVE INTO THE WESTERN ZONES BY 00Z TONIGHT AND CROSS THE AREA OVERNIGHT. SPC SSEO FROM 00Z LAST NIGHT SHOWED ACTIVE WEATHER EXITING THE AREA BETWEEN 06-09Z TONIGHT. ONLY TEMPERATURE ADJUSTMENT WAS TO LOWER READINGS INTO THE 80S IN FAR SE MT WHERE MIXING WILL BE JUST ABOVE 850 MB. ARTHUR && .SHORT TERM...VALID FOR TDY AND THU... ...TODAY... AN APPROACHING UPPER LEVEL LOW WILL PIVOT A NEGATIVELY TILTED SHORTWAVE ACROSS WESTERN MONTANA THIS AFTERNOON. THIS WILL PUSH A SURFACE LOW...CURRENTLY POSITIONED ACROSS SOUTHEAST IDAHO...ACROSS THE FORECAST AREA INTO EASTERN MONTANA BY TONIGHT. THE ACCOMPANYING SURGE OF SOUTHWESTERLY WIND BEHIND THE LOW WILL PUSH VERY DRY AIR ACROSS THE SOUTHERN PORTIONS OF THE FORECAST AREA BY THIS AFTERNOON...WITH THE MOIST GULF MOISTURE TAP WRAPPING AROUND THE NORTHERN SIDE OF THE LOW INTO THE GGW AND TFX FORECAST AREAS. EXPECT TO SEE DEW POINTS CRASH INTO THE 30S AND 40S ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA AS MIXING BECOMES ESTABLISHED IN THE LATE MORNING. OUR NORTHERN TIER OF COUNTIES WILL REMAIN ON THE GRADIENT BETWEEN THE DRY AIR AND MUCH MORE MOIST AIR AND SHOULD RETAIN DEW POINTS IN THE 50S. THESE HIGHER DEW POINTS WILL SUPPORT THE BETTER POTENTIAL FOR CONVECTION AND EVEN SOME SEVERE WEATHER IN THE FORM OF HAIL AND STRONG WINDS. HOWEVER...FARTHER SOUTH TOWARD BILLINGS THE LCLS WILL BE ALMOST 15K FEET WITH ALL THE CAPE EXTREMELY ELEVATED. CURRENT THINKING IS THAT THE BEST CHANCE OF STRONG TO SEVERE THUNDERSTORMS WILL PROGRESS FROM THE CRAZY MOUNTAINS TO HARLOWTON TO ROUNDUP TO NORTHERN ROSEBUD COUNTY BY THIS EVENING. HOWEVER FOR THE SOUTHERN TIER OF THE FORECAST AREA...EXPECT ONLY ISOLATED DRY THUNDERSTORMS WHICH COULD PRODUCE SOME GUSTY WINDS. EXPECT THE CONVECTIVE THREAT WILL END ACROSS THE FORECAST AREA BY 03 TO 06Z AS THE THREAT SHIFTS NORTH. ...TONIGHT AND THURSDAY... THE SURFACE COLD FRONT WILL PROGRESS ACROSS THE FORECAST AREA FROM THE LATE AFTERNOON IN THE WEST TO AFTER MIDNIGHT IN THE EAST. COOLER AIR WILL PUSH IN BEHIND THE FRONT BRINGING ALLOWING TEMPERATURES TO BE COOLER THAN LAST NIGHT IN CENTRAL AND WESTERN ZONES. WINDS WILL STAY UP OVERNIGHT IN THE EAST KEEPING OVERNIGHT LOWS IN THE MID TO UPPER 50S. TEMPERATURES WILL BE COOLER TOMORROW IN THE POST FRONTAL ENVIRONMENT WITH 700MB TEMPERATURES CRASHING AROUND +13C TO DOWN TO AROUND +5C. THUS EXPECT HIGH TEMPERATURES TO STAY MAINLY IN THE 70S THURSDAY. THE UPPER LEVEL LOW WILL STILL BE POSITIONED TO OUR WEST ON THURSDAY AND A NEW SURFACE LOW WILL DEVELOP OVER NORTHERN WYOMING GOING INTO THURSDAY EVENING. THIS ALLOWS EASTERLY LOW LEVEL WINDS TO INCREASE THE MOISTURE OVER SOUTHEAST MONTANA. THIS COMBINED WITH THE INVERTED SURFACE TROUGH ACROSS EASTERN MONTANA...EXPECT TO SEE AN INCREASED CHANCE OF DEVELOPING SOME SHOWERS BY THURSDAY EVENING. CHURCH .LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE... SLOWING TREND OF TRANSIT OF THE UPPER LOW THROUGH THE AREA IS BRINGING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS SATURDAY AND SUNDAY BUT HELPING MAKE LATER PERIODS DRIER. FRIDAY WILL STILL BE SEEING LOW LEVEL MOISTURE RECOVERING SO THERE IS A THREAT OF CONVECTION BUT PRECIP AMOUNTS WILL BE LIGHT. FRIDAY NIGHT THE UPPER LOW DIGS INTO SOUTHWESTERN MONTANA AND REALLY GIVES A CHANCE FOR MOISTURE TO DEEPEN ACROSS CENTRAL AND EASTERN MONTANA AT THE LOWER LEVELS DESPITE SOUTHWESTERLY FLOW ALOFT STILL TRYING TO ADVECT IN DRIER AIR. WITH STRONG DIFFLUENCE AND PLAINS MOISTURE WRAPPING BACK INTO THE YELLOWSTONE VALLEY LOOKS LIKE A GOOD CHANCE TO GET WET. SATURDAY IN PARTICULAR WILL HAVE TO BE WATCHED FOR THE STRENGTH OF STORMS WITH FAVORABLE SHEAR BUT INSTABILITY MAY BE LIMITED DUE TO COOL BOUNDARY LAYER TEMPERATURES. SUNDAY THE UPPER LOW EJECTS INTO EASTERN MONTANA AND WRAP AROUND MOISTURE CONTINUES TO BRING A THREAT OF SHOWERS AND THUNDERSTORMS TO MAINLY THE EASTERN HALF OF THE AREA. TEMPERATURES ON FRIDAY THROUGH SUNDAY COULD RUN 10 DEGREES BELOW NORMAL ESPECIALLY IF CLOUDS DOMINATE AND ENOUGH DYNAMIC COOLING OCCURS. MONDAY AND BEYOND IS DRYING AS FLOW BECOMES WESTERLY AND NEXT UPSTREAM SYSTEM IS PROGGED TO EJECT TO THE NORTH AND WEST OF MONTANA. BORSUM && .AVIATION... ISOLATED THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS BY EARLY THIS AFTERNOON WITH A FEW THUNDERSTORMS MOVING ONTO THE PLAINS WEST OF BILLINGS BY MID AFTERNOON. THE MAJORITY OF THE THUNDERSTORM ACTIVITY IS EXPECTED TO BE NORTH AND WEST OF KBIL. STRONG GUSTY WINDS WILL BE THE MAIN THREAT WITH ANY THUNDERSTORM. A COLD FRONT WILL MOVE ACROSS THE FORECAST AREA THIS EVENING INTO THE OVERNIGHT HOURS. HOOLEY && .PRELIMINARY POINT TEMP/POPS... TDY THU FRI SAT SUN MON TUE ------------------------------------------------------- BIL 093 052/077 052/072 052/069 051/078 054/082 056/082 1/T 11/B 23/T 34/T 41/B 11/B 22/T LVM 085 043/072 041/069 042/067 046/079 046/082 049/081 3/T 22/T 23/T 35/T 50/B 02/T 22/T HDN 095 053/078 052/074 050/072 050/078 052/082 052/083 1/T 11/B 32/T 34/T 41/B 11/B 22/T MLS 096 058/081 055/076 056/076 055/080 056/083 057/083 1/N 21/B 44/T 34/T 43/T 11/B 11/B 4BQ 095 054/081 055/076 054/075 053/079 054/084 055/084 1/N 11/B 44/T 34/T 52/T 11/B 22/T BHK 087 057/080 054/076 055/074 054/076 054/080 057/082 1/N 21/B 36/T 55/T 53/T 11/B 22/T SHR 090 048/078 050/073 048/073 047/076 049/081 050/082 1/T 11/B 32/T 24/T 41/B 11/B 11/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
649 PM CDT THU JUN 20 2013 .AVIATION... 00Z TAFS FOR KOFK...KOMA AND KLNK. VFR CONDITIONS EXPECTED THRU THE FCST PD. HOWEVER...LLWS AND POSSIBLE TSRA ARE PROMPTING AVN CONCERNS. FOR KOFK...STRENGTHENING LLVL JET/MOISTURE TRANSPORT MAY INDUCE ISOLD/SCT ACTIVITY OVER NERN NEB/ERN SD SOMETIME TWD MIDNIGHT ON NOSE OF LLVL JET. GIVEN UNCERTAINTY OF AREAL COVERAGE...HAVE OPTED TO GO WITH VFR CIGS IN TEMPO GROUP. AS FOR KOMA/KLNK...CANNOT DISCOUNT THE SMALL POSSIBILITY OF TSRA DEVELOPMENT SPREADING SWD AFT 09Z. AGAIN...HAVE OPTED FOR VFR CIGS IN THE PROB30 GROUPS AT BOTH TERMINALS. OTHERWISE...SLY WINDS KICK UP THRU FRI MORNING WITH GUSTS AROUND 25KT LIKELY. DEE && .PREV DISCUSSION... /ISSUED 304 PM CDT THU JUN 20 2013/ SHORT TERM...TONIGHT THROUGH FRIDAY. THE PRIMARY FORECAST CONCERNS IN THIS PERIOD ARE STILL THE POTENTIAL FOR TSTMS AND TEMPERATURES. UPPER AIR CHARTS FROM THIS MORNING SHOWED THE FOLLOWING. 80 KNOT WINDS AT 300 MB STRETCHED FROM NORTHERN CALIFORNIA INTO WYOMING. A LONGWAVE TROUGH WAS OVER THE WESTERN U.S. WITH A WEAK RIDGE OVER THE PLAINS. 12 HOUR HEIGHT FALLS OF 110 METERS WERE NOTED AT 500 MB OVER MONTANA. THERMAL RIDGE AT 700 MB EXTENDED FROM MEXICO NORTHWARD INTO EASTERN COLORADO. THE KOAX 12Z SOUNDING SHOWED A 700 MB TEMP OF 8 C AND A DEWPOINT OF 4 C. MOIST BAND AT 700 MB EXTENDED FROM WEST TEXAS UP INTO THE DAKOTAS. THIS MOISTURE WILL BE ONE OF THE THINGS TO MONITOR IN REGARDS TO CONVECTIVE COVERAGE THE NEXT SEVERAL DAYS. SURFACE ANALYSIS EARLY THIS AFTN SHOWED ONE LOW PRESSURE CENTER UP ALONG THE NORTH DAKOTA/SOUTH DAKOTA BORDER AND ANOTHER IN SOUTHEAST COLORADO. A COLD FRONT STRETCHED FROM THE LOW OVER THE DAKOTAS DOWN INTO WESTERN NEBRASKA AND NORTHEAST COLORADO. GUSTY SOUTH WINDS WERE IN PLACE ACROSS THE FORECAST AREA WITH DEWPOINTS IN THE UPPER 60S TO AROUND 70. THIS EVENING...WINDS SHOULD RELAX A LITTLE. THE ATMOSPHERE WILL BE VERY UNSTABLE...WITH CAPE VALUES IN EXCESS OF 3000 J/KG AND 0-6 KM SHEAR VALUES OF 20-30 KNOTS. HOWEVER...LIKE YESTERDAY...WE DO NOT HAVE MUCH OF A FOCUSING MECHANISM FOR STORM DEVELOPMENT. MOST RECENT HRRR AND 13 KM RAP MODELS SUGGEST SOME STORMS ARE POSSIBLE ALONG AND EAST OF THE MID LEVEL CAP...AS WELL AS ACROSS PARTS OF NORTHEAST NEBRASKA. 4 KM WRF-NMM RUN FROM 12Z IS MUCH MORE BULLISH WITH STORM DEVELOPMENT THIS EVENING FROM THE DAKOTAS/MINNESOTA DOWN INTO PARTS OF NORTHERN AND WESTERN NEBRASKA. ALTHOUGH THAT IS ONE POSSIBILITY...TENDED TO SHY AWAY FROM THAT SCENARIO. BOTH THE 12Z NAM AND GFS ALSO APPEARED TOO WET TONIGHT IN OUR AREA. FRIDAY...KEPT THUNDERSTORM CHANCES BELOW 15 PERCENT. TEMPERATURES SHOULD TOP OUT IN THE LOWER OR MID 90S WITH MAX HEAT INDICES UP NEAR 100. WINDS SHOULD INCREASE INTO THE BREEZY OR WINDY CATEGORY AGAIN. MILLER LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. THE BEST CHANCES FOR THUNDERSTORMS IN THIS PERIOD APPEAR TO BE FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. A GENERAL BLEND/CONSENSUS OF THE 12Z MODELS IS THAT A FRONTAL BOUNDARY SHOULD PUSH INTO OUR AREA FROM THE NORTHWEST SATURDAY NIGHT...THEN LINGER IN THE AREA SUNDAY AND SUNDAY NIGHT. INSTABILITY AND SHEAR APPEAR THAT THEY WOULD BE ADEQUATE FOR SOME ORGANIZED SEVERE WEATHER. THE TENDENCY FOR A TROUGH AT 500 MB OVER THE WESTERN U.S. SHOULD CONTINUE INTO EARLY NEXT WEEK. AFTER THAT...A MORE SUMMER-LIKE FLOW PATTERN IS FORECAST TO DEVELOP DUE TO RETROGRESSION. TROUGH AXIS WILL SHIFT BACK TO AROUND 140 DEGS WEST LONGITUDE WHILE A 500 MB RIDGE STRENGTHENS OVER THE DESERT SOUTHWEST AND SOUTHERN ROCKIES. KEPT A MAINLY DRY FORECAST GOING FOR MONDAY INTO THURSDAY...DUE TO LOW CONFIDENCE. KEPT HIGHS MAINLY IN THE UPPER 80S TO MID 90S WITH LOWS IN THE UPPER 60S TO MID 70S. MILLER && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS HASTINGS NE
432 PM CDT WED JUN 19 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 430 PM CDT WED JUN 19 2013 MORE LOW-CONFIDENCE THUNDERSTORM CHANCES ARE THE MAIN CONCERN ESPECIALLY FOR LATE TONIGHT...WITH REASONABLE CONFIDENCE THAT THE THURSDAY DAYTIME HOURS SHOULD HOLD STORM-FREE UNDER A STRENGTHENING CAP. OTHERWISE...HEAT/HUMIDITY THURSDAY IS EXPECTED TO RISE ANOTHER NOTCH ABOVE THAT OF TODAY AS A GRADUAL WARMING TREND CONTINUES. 20Z SURFACE ANALYSIS HIGHLIGHTS A DEEPENING 996 MILLIBAR LOW OVER CENTRAL WY...WHICH HAS TIGHTENED THE CENTRAL PLAINS PRESSURE GRADIENT THUS RESULTING IN SUSTAINED SOUTH-SOUTHEAST WINDS 15-25 MPH THIS AFTERNOON GUSTING 30-35 MPH IN SPOTS. THIS SURFACE LOW HAS DEEPENED IN RESPONSE TO A FAIRLY VIGOROUS...NEGATIVELY TILTED SHORTWAVE TROUGH BARRELING NORTHEAST ACROSS SOUTHERN ID...ALONG THE SOUTHEAST PERIPHERY OF AN EXPANSIVE CLOSED MID LEVEL LOW ANCHORED OVER THE PACIFIC NORTHWEST. CLOSER TO HOME...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA DEPICT MODEST QUASI-ZONAL FLOW...WITH THE MAIN SUBTLE SHORTWAVE TROUGH CURRENTLY EXITING THE CWA EASTWARD...WITH MID LEVEL DRYING NOTED IN ITS WAKE. JUST WITHIN THE PAST HOUR...A FEW SHOWERS/THUNDERSTORMS HAVE FLARED UP JUST EAST OF OUR CWA IN EASTERN NEB...IN CLOSER PROXIMITY TO THIS ADVANCING WAVE AND IN THE PRESENCE OF A WEAKLY CAPPED AIRMASS FEATURING 1500+ J/KG 0-1KM MLCAPE. ACROSS OUR AREA HOWEVER...AT LEAST UP THROUGH NOW...ITS BEEN A RAIN/THUNDER-FREE DAY...UNDER ONLY A FAIR WEATHER CUMULUS FIELD MOST AREAS...AND A BIT MORE MID- LEVEL CLOUD DEVELOPMENT IN THE FAR WEST WITHIN A ZONE OF THETA-E ADVECTION EVIDENT AT 700MB. UNLIKE YESTERDAY AT THIS TIME...THERE IS NO SURFACE FRONT/OUTFLOW BOUNDARY AND NO EVIDENT SUBTLE INCOMING SHORTWAVE TO KICK OFF CONVECTION...AND IT GOES WITHOUT SAYING THAT SEVERAL DETERMINISTIC MODEL QPF FIELDS ENDED UP BEING CONSIDERABLY OVERDONE ON RAIN POTENTIAL TODAY. TEMP-WISE...MOST AREAS ARE HEADED FOR HIGHS BETWEEN 86-91. LOOKING AHEAD THROUGH LATE THIS AFTERNOON INTO TONIGHT...THE BIG PICTURE ALOFT INVOLVES A NORTHWARD BUILDING OF A SOUTH CENTRAL CONUS RIDGE INTO THE CENTRAL PLAINS...WHILE THE STRONG SHORTWAVE TROUGH WELL TO THE NORTHWEST SLIDES UP ACROSS MT. MEANWHILE OVER THE LOCAL AREA...FLOW WILL REMAIN QUASI-ZONAL AS AT LEAST 1-2 MORE VERY SUBTLE DISTURBANCES POSSIBLY PASS EASTWARD ACROSS THE REGION. OF NOTE...PRONOUNCED WEST-EAST MID LEVEL WARM-AIR ADVECTION OF AN ELEVATED MIXED LAYER WILL OCCUR TONIGHT...WITH 700MB TEMPS BY SUNRISE PROGGED TO RANGE FROM AROUND 10C IN THE EASTERN CWA TO AROUND 15C IN THE WEST. AT THE SURFACE...A NORTH-SOUTH TROUGH AXIS WILL ADVANCE EASTWARD INTO WESTERN NEB/FAR WESTERN KS TONIGHT...BUT OUT AHEAD OF THIS FEATURE THE CWA WILL CONTINUE TO EXPERIENCE STEADY SOUTH-SOUTHEAST BREEZES GENERALLY SUSTAINED 15+ MPH WITH SOME HIGHER GUSTS. THIS SHOULD HELP RESULT IN SLIGHTLY MILDER LOW TEMPS VERSUS LATELY...AND NUDGED PREVIOUS VALUES UP SLIGHTLY WITH MOST AREAS BOTTOMING OUT 65-69. STARTING TO SOUND LIKE A BROKEN RECORD...BUT WITH MODELS CONTINUING TO STRUGGLE MIGHTILY WITH CONVECTIVE TRENDS...CONFIDENCE IS BELOW AVERAGE. THE BOTTOM LINE IS THAT THERE IS ONLY A 20 PERCENT CHANCE OF SHOWERS/STORMS CWA-WIDE THROUGH 01Z/8PM...AND THEN AGAIN AFTER MIDNIGHT. THE PRE-8PM POTENTIAL WOULD STEM FROM ANY DIURNALLY- DRIVEN CONVECTION THAT WOULD MOST LIKELY FLIRT WITH FAR EASTERN COUNTIES...AND ANY HIGHER-BASED MID LEVEL CONVECTION THAT MIGHT SKIRT THE WEST. ALTHOUGH THE LIKELIHOOD OF VIGOROUS DEVELOPMENT IS QUITE LOW GIVEN LACK OF FORCING/LOW LEVEL FOCUS...CANNOT COMPLETELY RULE OUT A ROGUE STRONG/SEVERE STORM. BY SUNSET...HAVE DECENT CONFIDENCE IN A DRY PERIOD LOCALLY LASTING SEVERAL HOURS...BEFORE THE NEXT QUESTION BECOMES...DOES ANYTHING THAT DEVELOPS OUT WEST THIS EVENING SURVIVE EASTWARD INTO THE CWA...OR DOES NEW DEVELOPMENT OCCUR ON THE EDGE OF THE MID-LEVEL CAP AND WITHIN THE AXIS OF A FAIRLY STOUT 50+ KT LOW LEVEL JET. ALTHOUGH AM ONLY KEEPING POPS AT 20 PERCENT...IT WOULD SEEM THIS LATE NIGHT STORM POTENTIAL COULD BE A BIT MORE LIKELY/WIDESPREAD THAN LATE THIS AFTERNOON/EARLY EVENING...WITH MODELS SUCH AS THE RAP FIRING UP A DECENT AREA OF OVERNIGHT STORMS ESPECIALLY IN CENTRAL/EASTERN COUNTIES. SHOULD THESE STORMS ACTUALLY DEVELOP...CERTAINLY CAN/T DISCOUNT A THREAT FOR SEVERE HAIL WITH THE NAM DEPICTING 2000+ J/KG MUCAPE TO PARCELS BETWEEN 850-700MB. COULD BE AN INTERESTING FEW HOURS LATE TONIGHT IF IN FACT SOMETHING HAPPENS TO FIRE. TURNING TO THE THURSDAY DAYTIME PERIOD...OPTED TO HOLD THE COURSE FROM PREVIOUS FORECAST AND KEEP OUT ANY SHOWER/STORM MENTION FROM 12Z-00Z/7AM-7PM. ALOFT...AT LEAST SMALL MID LEVEL HEIGHT-RISES WILL CONTINUE AS THE RIDGE BUILDS INTO THE CENTRAL CONUS FROM THE SOUTHWEST...WHILE VERY WARM MID LEVEL 700MB TEMPS OF GENERALLY 13-15C OVERSPREAD THE ENTIRE CWA BY MID-AFTERNOON. AT THE SURFACE...THE AFOREMENTIONED TROUGH AXIS WILL STALL OUT FROM NORTH CENTRAL TO SOUTHWEST NEB DURING THE AFTERNOON...WHICH WILL ALLOW FOR RELAXING BREEZES ACROSS OUR FAR WESTERN COUNTIES...WHILE THE MAJORITY OF THE CWA CONTINUES TO EXPERIENCE SOUTHERLY SUSTAINED SPEEDS 15-20 MPH. WITH WARMER TEMPS MOVING IN ALOFT...DECENT MIXING...AND AT LEAST A FAIR AMOUNT OF SUNSHINE ESPECIALLY ONCE ANY POSSIBLE MORNING STRATUS BURNS OFF/LIFTS AWAY...WILL AIM FOR HIGHS RANGING FROM NEAR 90 NORTHEAST TO UPPER 90S SOUTHWEST...WHICH COMBINED WITH DEWPOINTS AVERAGING MID-UPPER 60S WILL YIELD HEAT INDEX VALUES GENERALLY 92-98 AT MID-AFTERNOON. THERE ARE TWO CAVEATS THAT COULD MESS UP THE DRY FORECAST. FIRST OFF...THERE IS A CHANCE THAT ANY LATE NIGHT/PRE-DAWN CONVECTION MAY NOT QUITE CLEAR OUR EASTERN COUNTIES BY 7AM IF IT FIRES UP...BUT GIVEN UNCERTAINTY IN DEVELOPMENT IN THE FIRST PLACE WILL DEFER TO NEXT SHIFT TO TAKE A CLOSER LOOK AT THE POSSIBILITY OF SOME MORNING POPS MAINLY WITHIN THE EASTERN 1/4 OF THE CWA. AGAIN...CAN/T RULE OUT SOME SEVERE-CRITERIA HAIL IF THIS UNFOLDS. ONCE THIS POTENTIAL MORNING CONVECTION VACATES...THE VAST MAJORITY OF THE DAY SHOULD BE STRONGLY CAPPED...AND THINK IT SHOULD HOLD THROUGH AT LEAST 7PM...DESPITE THE NAM ADVERTISING A VOLATILE LATE AFTERNOON ENVIRONMENT WITH 4000+ J/KG MLCAPE AND WEAK TO MODEST 25KT OF DEEP-LAYER SHEAR. REFLECTIVITY PROG FROM THE 12Z 4KM WRF- NMM CLEARLY KEEPS CONVECTION AT BAY LOCALLY...ALTHOUGH THE ECMWF DOES SUGGEST OUR FAR WESTERN COUNTIES COULD COME SOMEWHAT CLOSE TO ANYTHING THAT HAPPENS TO BREACH THE CAP ALONG THE TROUGH AXIS LYING NEAR THE CWA...BUT AGAIN THIS SEEMS AN UNLIKELY SCENARIO AND THUS THE LACK OF STORM MENTION AT THIS TIME. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 430 PM CDT WED JUN 19 2013 MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS AND TEMPERATURES. MODELS ARE FAIRLY SIMILAR IN THE MAIN FEATURES THROUGH THE PERIOD. AN UPPER LEVEL LOW MOVES OUT OF THE NORTHERN ROCKIES AND INTO THE CANADIAN PLAINS THURSDAY NIGHT THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK...THEN AN UPPER LEVEL RIDGE BUILDS OVER THE AREA. FOR THURSDAY NIGHT THROUGH SATURDAY THERE IS A SURFACE WARM FRONT DRAPED THROUGH CENTRAL NEBRASKA. MODELS HAVE SOME SLIGHT DIFFERENCES IN THE LOCATION OF THE FRONT...BUT GENERALLY OVER THE FAR NORTHERN PART OF THE FORECAST AREA. AS AN UPPER LEVEL WAVE MOVES INTO THE AREA MODELS BRING IN SOME QPF ALONG THE FRONT THURSDAY NIGHT. THE CONCERN IS THAT THE 700MB TEMPERATURES ARE AT OR ABOVE 12 DEG C DURING THIS PERIOD. WITH THE FRONT IN THE AREA THERE IS SOME POTENTIAL THAT A THUNDERSTORM MIGHT BREAK THROUGH...BUT REALLY BELIEVE THAT WE WILL BE TOO CAPPED TO GET ANYTHING GOING. ON THE OFF CHANCE THAT THERE IS A THUNDERSTORM IT HAS THE POTENTIAL TO BE SEVERE. THE MUCAPE IN THE NORTH DURING THE EVENING IS AROUND 4500 J/KG. DURING THE DAYTIME BOTH FRIDAY AND SATURDAY HAVE MAINTAINED SOME SLIGHT CHANCE FOR THUNDERSTORMS IN THE SOUTHWEST. THIS WOULD BE MAINLY DURING THE AFTERNOON. EVEN THOUGH TEMPERATURES ARE EXPECTED TO BE QUITE WARM THAT AREA SEEMS PRONE TO SOME ISOLATED THUNDERSTORMS DURING THE HEAT OF THE DAY. SATURDAY NIGHT THROUGH SUNDAY NIGHT THE SURFACE LOW MOVES TOWARD THE EAST AND MAINLY STALLS ACROSS THE AREA BY SUNDAY AFTERNOON. WITH A COUPLE OF UPPER LEVEL WAVES THAT MOVE INTO THE AREA THERE COULD BE SOME THUNDERSTORMS ALONG THE FRONT. THE BEST CHANCES WOULD BE DURING THE NIGHT TIME HOURS. THE UPPER LEVEL PATTERN CHANGES LATE IN THE PERIOD AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE AREA. THE FEW UPPER LEVEL WAVES THAT MOVE ACROSS IT TEND TO BE FURTHER TO THE NORTH. EVEN IF THE SURFACE LOW IS TO THE WEST THERE ARE NOT MANY THUNDERSTORMS THAT TAKE OFF ON THE HIGH PLAINS. THEREFORE HAVE KEPT THE FORECAST DRY FOR MONDAY THROUGH WEDNESDAY. TEMPERATURES THROUGH THE PERIOD WILL REMAIN ON THE WARM SIDE. EARLY IN THE PERIOD THE WARM FRONT IS THROUGH THE AREA AND EVEN THE SURFACE LOW AS IT MOVES TO THE EAST DOES NOT BRING MUCH IN THE WAY OF COOLER TEMPERATURES. TEMPERATURES ARE EXPECTED TO BE QUITE A BIT ABOVE NORMAL. && .AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 117 PM CDT WED JUN 19 2013 AT LEAST FOR NOW...VFR CEILING/VISIBILITY IS FORECAST TO PREVAIL THROUGH THE PERIOD...BUT THERE ARE A FEW QUESTION MARKS. STARTING WITH THIS AFTERNOON/EVENING...CONFIDENCE IS HIGH IN VFR CONDITIONS WITH ONLY THE SLIGHTEST CHANCE OF A SHOWER/THUNDERSTORM NOT WORTH MENTIONING. LATE TONIGHT INTO THURSDAY MORNING...THERE ARE SIGNS THAT AN MVFR STRATUS DECK COULD OVERTAKE THE AREA...BUT GIVEN HOW POORLY MODELS HAVE HANDLED OTHER WEATHER ELEMENTS LATELY...AM NOT QUITE READY TO JUMP ON BOARD SO FOR NO HAVE ONLY INDICATED SCATTERED LOW CLOUDS...AND WILL DEFER TO LATER FORECASTS TO BEEF UP THE POTENTIAL OR NOT. THERE COULD ALSO BE A LATE-NIGHT THUNDERSTORM...BUT AGAIN CHANCES SEEM TO LOW TO MENTION. WIND-WISE...SURFACE WINDS WILL AVERAGE FAIRLY BREEZY THROUGHOUT THE PERIOD...WITH DAYTIME SUSTAINED SPEEDS AROUND 16-17KT AND GUST POTENTIAL TO AROUND 25KT...AND EVEN OVERNIGHT GUSTS TO AROUND 20KT. HAVE INTRODUCED A MENTION OF LOW LEVEL WIND SHEAR WITH THIS FORECAST BETWEEN 06Z-15Z...AS A STRONG LOW LEVEL JET DEVELOPS OVERHEAD. WIND SPEEDS BETWEEN 1500 AND 2000 FT AGL ARE FORECAST TO TO RAMP UP BETWEEN 40-46KT FROM THE SOUTH...CREATING AT LEAST 30-35 KNOTS OF BULK SHEAR MAGNITUDE BETWEEN THE SURFACE AND THIS LEVEL CONSIDERING SUSTAINED SURFACE SPEEDS ONLY AROUND 14KT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...JCB AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1250 PM CDT WED JUN 19 2013 .AVIATION... 18Z TAFS FOR KOMA...KLNK...KOFK. THESE TYPICAL MID JUNE PATTERNS GENERALLY CONSIST OF VFR CONDITIONS MOST OF THE TIME EXCEPT FOR DURING PERIODS OF THUNDERSTORMS. UNFORTUNATELY THE CONFIDENCE IN PICKING OUT WHEN AND WHERE STORMS WILL DEVELOP IS RATHER LOW...AND THIS PATTERN IS NO EXCEPTION. THERE ARE SOME WEAK SIGNALS THAT POINT TO NORTHEAST NEBRASKA DURING THE LATE AFTERNOON AND EVENING TIME FRAME...WHICH WOULD HAVE A GREATER IMPACT ON THE KOFK TAF. HOWEVER GIVEN THE HIGH UNCERTAINTY... HAVE LEFT TRW OUT OF THE TAFS AT THIS TIME AND WILL CLOSELY BE MONITORING RADAR FOR TRENDS. NIETFELD && .PREV DISCUSSION... /ISSUED 337 AM CDT WED JUN 19 2013/ DISCUSSION... ALTHOUGH WE ARE NOT EXPECTING A CONTINUOUS PERIOD OF SHOWERS AND THUNDERSTORMS OVER THE NEXT 48 HOURS...IT REALLY IS DIFFICULT TO DISCERN ANY PERIOD IN THAT TIME THAT SHOULD NOT WARRANT AT LEAST A SLIGHT CHANCE POP. THEREFORE...WE WILL BE CARRYING A SMALL POP FOR PORTIONS OF THE CWA THROUGH THIS TIME WITH GREAT UNCERTAINTY ON TIMING/LOCATION. MODEL GUIDANCE HAS PERFORMED RATHER POORLY ON WEAK CONVECTIVE EVENTS IN THE PAST COUPLE DAYS AND SO FORECASTER CONFIDENCE REMAINS LOW. UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY SHOW A LARGE TROUGH OFF THE PACIFIC COAST WITH THE LOW PRESSURE CENTERED JUST OFF THE OREGON/WASHINGTON COASTS. OUT AHEAD OF THIS IS A WEAK RIDGE OF HIGH PRESSURE EXTENDING FROM THE SOUTHERN PLAINS INTO THE WESTERN DAKOTAS. SEVERAL WEAK IMPULSES ARE EMBEDDED WITHIN THE SOUTHWEST FLOW IN BETWEEN THE MAIN FEATURES. THE FIRST SHORTWAVE OF CONCERN IS CURRENTLY LOCATED OVER THE NEBRASKA PANHANDLE. LATEST REGIONAL RADAR MOSIAC SHOWS A CONVECTIVE COMPLEX SLOWLY DRIFTING EAST AND WEAKENING ACROSS WESTERN NEBRASKA WHILE ANOTHER MOVES SLOWLY NORTHEAST ACROSS NORTHWEST KANSAS AND WEAKENS. LATEST RAP BRINGS A HINT OF THIS ACTIVITY INTO THE FORECAST AREA THROUGHOUT THE MORNING AND AM GOING TO TWEEK POPS ACCORDINGLY. BROAD SCALE LIFT ASSOCIATED WITH THE MID LEVEL IMPULSE WILL STILL BE PRESENT INTO THE AFTERNOON AND AS INSTABILITY INCREASES WITH DAYTIME HEATING...FEEL THUNDERSTORMS HAVE A CHANCE TO CONTINUE ACROSS THE FORECAST AREA IN A BROAD LOW LEVEL WARM AIR ADVECTION REGIME. LOW LEVEL JET WILL VEER SLIGHTLY OVERNIGHT AND COULD SUSTAIN CONVECTIVE ACTIVITY...THEREFORE WILL CONTINUE A POP THROUGH THE OVERNIGHT. BY THURSDAY...THE UPPER RIDGE AXIS WILL BE DIRECTLY OVERHEAD AND EXTEND INTO THE EASTERN DAKOTAS. IN ADDITION...A SFC COLD FRONT WILL EXTEND SOUTH ACROSS THE CENTRAL DAKOTAS AND INTO NORTHWEST NEBRASKA WHICH WILL LIKELY BE THE FOCUS FOR THUNDERSTORM DEVELOPMENT. VERY STRONG INSTABILITY WILL EXIST IN OUR NORTHERN CWA HOWEVER A QUITE STOUT CAP WILL ALSO BE IN PLACE WHICH MAY PROHIBIT THE EASTWARD EXPANSION OF TSTMS. SPC HAS INCLUDED OUR NORTH IN THE SWODY2 FOR ANY MCS ACTIVITY MOVING SOUTHEAST FROM NRN PLAINS CONVECTION. THIS WILL BE AIDED BY A VEERING SOUTHWEST LOW LEVEL JET AND SO HAVE HIGHER POPS GOING IN OUR NORTH. THE AREA IS DOMINATED BY SOUTHWEST FLOW ALOFT INTO THE WEEKEND WITH THE MAIN UPPER LOW MOVING ACROSS THE PACIFIC NORTHWEST AND TOWARD THE NORTHERN PLAINS. THE MAIN SFC BOUNDARY WILL REMAIN TO OUR NORTH LEAVING THE REGION IN THE WARM SECTOR. HIGHS WILL LIKELY TOP OUT IN THE LOW 90S. AS THE UPPER LOW MOVES TOWARD THE NORTHERN PLAINS BY SUNDAY...THE SFC FRONT WILL DROP SOUTH INTO THE AREA AND BE THE POTENTIAL FOCUS FOR THUNDERSTORMS. KERN && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
608 AM CDT WED JUN 19 2013 .AVIATION... 12Z TAFS FOR KOFK...KOMA AND KLNK. ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS EASTERN NEBRASKA THIS MORNING WITH CHANCES INCREASING LATER TODAY...ESPECIALLY OVERNIGHT. DUE TO THE APPARENT MINIMAL COVERAGE AND LOW CONFIDENCE W/RESPECT TO TIMING...NO MENTION WAS MADE AT TAFS EXPECT AT KOFK LATE TONIGHT WHEN LOW LEVEL JET MAY HAVE MORE SUCCESS IN BRINGING A BIT MORE WIDESPREAD ACTIVITY TOWARD THAT AREA. OUTSIDE OF ANY CONVECTION...VFR CONDITIONS ARE EXPECTED. CHERMOK && .PREV DISCUSSION... /ISSUED 337 AM CDT WED JUN 19 2013/ DISCUSSION... ALTHOUGH WE ARE NOT EXPECTING A CONTINUOUS PERIOD OF SHOWERS AND THUNDERSTORMS OVER THE NEXT 48 HOURS...IT REALLY IS DIFFICULT TO DISCERN ANY PERIOD IN THAT TIME THAT SHOULD NOT WARRANT AT LEAST A SLIGHT CHANCE POP. THEREFORE...WE WILL BE CARRYING A SMALL POP FOR PORTIONS OF THE CWA THROUGH THIS TIME WITH GREAT UNCERTAINTY ON TIMING/LOCATION. MODEL GUIDANCE HAS PERFORMED RATHER POORLY ON WEAK CONVECTIVE EVENTS IN THE PAST COUPLE DAYS AND SO FORECASTER CONFIDENCE REMAINS LOW. UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY SHOW A LARGE TROUGH OFF THE PACIFIC COAST WITH THE LOW PRESSURE CENTERED JUST OFF THE OREGON/WASHINGTON COASTS. OUT AHEAD OF THIS IS A WEAK RIDGE OF HIGH PRESSURE EXTENDING FROM THE SOUTHERN PLAINS INTO THE WESTERN DAKOTAS. SEVERAL WEAK IMPULSES ARE EMBEDDED WITHIN THE SOUTHWEST FLOW IN BETWEEN THE MAIN FEATURES. THE FIRST SHORTWAVE OF CONCERN IS CURRENTLY LOCATED OVER THE NEBRASKA PANHANDLE. LATEST REGIONAL RADAR MOSIAC SHOWS A CONVECTIVE COMPLEX SLOWLY DRIFTING EAST AND WEAKENING ACROSS WESTERN NEBRASKA WHILE ANOTHER MOVES SLOWLY NORTHEAST ACROSS NORTHWEST KANSAS AND WEAKENS. LATEST RAP BRINGS A HINT OF THIS ACTIVITY INTO THE FORECAST AREA THROUGHOUT THE MORNING AND AM GOING TO TWEEK POPS ACCORDINGLY. BROAD SCALE LIFT ASSOCIATED WITH THE MID LEVEL IMPULSE WILL STILL BE PRESENT INTO THE AFTERNOON AND AS INSTABILITY INCREASES WITH DAYTIME HEATING...FEEL THUNDERSTORMS HAVE A CHANCE TO CONTINUE ACROSS THE FORECAST AREA IN A BROAD LOW LEVEL WARM AIR ADVECTION REGIME. LOW LEVEL JET WILL VEER SLIGHTLY OVERNIGHT AND COULD SUSTAIN CONVECTIVE ACTIVITY...THEREFORE WILL CONTINUE A POP THROUGH THE OVERNIGHT. BY THURSDAY...THE UPPER RIDGE AXIS WILL BE DIRECTLY OVERHEAD AND EXTEND INTO THE EASTERN DAKOTAS. IN ADDITION...A SFC COLD FRONT WILL EXTEND SOUTH ACROSS THE CENTRAL DAKOTAS AND INTO NORTHWEST NEBRASKA WHICH WILL LIKELY BE THE FOCUS FOR THUNDERSTORM DEVELOPMENT. VERY STRONG INSTABILITY WILL EXIST IN OUR NORTHERN CWA HOWEVER A QUITE STOUT CAP WILL ALSO BE IN PLACE WHICH MAY PROHIBIT THE EASTWARD EXPANSION OF TSTMS. SPC HAS INCLUDED OUR NORTH IN THE SWODY2 FOR ANY MCS ACTIVITY MOVING SOUTHEAST FROM NRN PLAINS CONVECTION. THIS WILL BE AIDED BY A VEERING SOUTHWEST LOW LEVEL JET AND SO HAVE HIGHER POPS GOING IN OUR NORTH. THE AREA IS DOMINATED BY SOUTHWEST FLOW ALOFT INTO THE WEEKEND WITH THE MAIN UPPER LOW MOVING ACROSS THE PACIFIC NORTHWEST AND TOWARD THE NORTHERN PLAINS. THE MAIN SFC BOUNDARY WILL REMAIN TO OUR NORTH LEAVING THE REGION IN THE WARM SECTOR. HIGHS WILL LIKELY TOP OUT IN THE LOW 90S. AS THE UPPER LOW MOVES TOWARD THE NORTHERN PLAINS BY SUNDAY...THE SFC FRONT WILL DROP SOUTH INTO THE AREA AND BE THE POTENTIAL FOCUS FOR THUNDERSTORMS. KERN && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
542 PM MDT THU JUN 20 2013 .AVIATION... 00Z TAF CYCLE STRONGER CONVECTION IS MOVING EAST OUT OF NM AND INTO TEXAS THIS EVENING. SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE NEAR KROW AND POINTS JUST NORTH AND EAST. BRIEF MVFR CIGS WILL BE POSSIBLE WITH THIS ACTIVITY THROUGH APPROX 02Z. GUSTY OUTFLOW WINDS FROM THESE THUNDERSTORMS WILL BE THE MAIN THREAT HOWEVER...WITH GUSTS UP TO 40KTS POSSIBLE AS WELL AS BLDU REDUCING VISIBILITIES DOWN TO 3 MILES AT TIMES. STRONG SOUTHERLY WINDS WILL BE THE RULE ACROSS THE PLAINS TONIGHT ONCE AGAIN AS THE LLJ INCREASES. MEANWHILE...STRONG SOUTHWEST WINDS ACROSS CENTRAL AND WESTERN NM WILL DECREASE THIS EVENING BUT WILL RAMP BACK UP ON FRIDAY...WITH GUSTS NEAR 35KTS. ADDITIONALLY...SMOKE FROM THE WILDFIRE WEST OF KTCS MAY IMPACT AREAS NEAR AND SE OF KONM THROUGH THE EVENING. A FEW SHOWERS OR TSTMS WILL AGAIN BE POSSIBLE THURSDAY AFTERNOON AND EVENING ACROSS THE SE PLAINS. 34 && .PREV DISCUSSION...328 PM MDT THU JUN 20 2013... SATELLITE AND SURFACE MOISTURE ANALYSIS SHOW THE MOIST AXIS FOCUSED FROM NORTHERN MEXICO ACROSS SE NEW MEXICO INTO WEST TX. THE LATEST RADAR TRENDS INDICATE SHOWER AND STORM COVERAGE INCREASING IN THIS AREA...WHICH COINCIDES WELL WITH THE 17Z HRRR AND RIDGE OF HIGHEST THETA-E VALUES FROM THE NAM AND GFS. FARTHER WEST THE FOCUS FOR DRY AND BREEZY CONDITIONS COINCIDES WITH A MID/UPPER LEVEL DRY SLOT STRETCHING FROM THE BAJA INTO NORTH CENTRAL NM. THE DEFINITION OF PERSISTENCE WILL HOLD VERY TRUE ACROSS OUR AREA AS THERE WILL BE VERY LITTLE CHANGE TO THE PATTERN CONFIGURATION THRU TUESDAY OF NEXT WEEK. EXPECT VERY DRY...BREEZY...AND HOT CONDITIONS FOR CENTRAL AND WESTERN NM WITH A FEW STORMS FOCUSED OVER THE SE AND EAST CENTRAL PLAINS. MAX AND MIN TEMPS WILL BE NEARLY THE SAME EVERY PERIOD AND ABOVE NORMAL HOWEVER NO RECORDS ARE EXPECTED. UNFORTUNATELY...EVEN HOTTER CONDITIONS BUT WITH LESS WIND WILL OCCUR FOR THE WEDNESDAY THRU SATURDAY PERIOD OF NEXT WEEK. THIS MAY BE THE PEAK FOR THE SUMMER WITH A 596 TO 599DM H5 RIDGE CENTERED DIRECTLY OVER NORTHERN NM AND SOUTHERN CO. THE ECMWF AND GFS THEN SHOW THE RIDGE WOBBLING WESTWARD INTO NORTHERN AZ ALLOWING A MOIST BACK DOOR FRONT TO SLIDE INTO THE EAST. THIS WOULD PROVIDE FOR ANOTHER UPTICK IN STORM COVERAGE HOWEVER CONFIDENCE ON THIS PATTERN IS VERY LOW AS CONSISTENCY IS POOR FROM MODEL RUN TO RUN. GUYER .FIRE WEATHER... DRY LINE HAS BEEN DRIVEN BACK TO A LINE FROM JUST EAST OF TUCUMCARI TO NEAR OR JUST W OF DUNKEN...PRETTY MAJOR EROSION CONSIDERING HOW FAR WEST IT GOT EARLY THIS MORNING. SHOULD WAFT BACK W TONIGHT...BUT NOT QUITE AS FAR W AS EARLY TODAY. POOR RH RECOVERIES TONIGHT WEST OF DRY LINE...BASICALLY W OF A RATON TO RUIDOSO LINE. GOOD TO EXCELLENT RECOVERIES TO E OF THE DRY LINE. SOME SHOWERS AND STORMS OF WET VARIETY INTO THE EVE NEAR TO E OF TUCUMCARI TO RUIDOSO LINE. RED FLAG CONDITIONS OF THIS AFTN SHOULD DROP OUT BETWEEN 7 AND 9 PM. AT LEAST THRU NEXT TUE LOOKING FOR CURRENT PATTERN TO NOT CHANGE MUCH...GENERALLY A PATTERN OF A FEW TO SCT SHOWERS AND STORMS...MOSTLY WET...GENERALLY NEAR AND EAST OF A TUCUMCARI TO RUIDOSO LINE. MAY ON A COUPLE OF OCCASIONS SEE THAT LINE SHIFT UP TO 75 OR 100 MILES FARTHER E OR W DURING THIS PERIOD. SET UP WILL BE A PACIFIC NW TROUGH AND AN UPPER HIGH GENERALLY CENTERED BETWEEN CENTRAL TX AND FAR N MEXICO. VERY DRY AIR WILL KEEP COMING ACROSS NW HALF TO TWO THIRDS OF NM AROUND THE HIGH...RESULTING IN EXTREMELY LOW RH MINIMUMS AND MANY HOURS OF SINGLE DIGIT HUMIDITIES TO CONTINUE AS WELL FROM THE CENTRAL MTN CHAIN WEST TO THE AZ BORDER. THOUGH DRY THE AIRMASS WILL BE UNSTABLE WITH DAYTIME HEATING AND ABOVE NORMAL TEMPERATURES. HAINES VALUES OF 6 AND EVEN SOME LOCALIZED SUPER HAINES WILL SHOW UP LATE IN THE DAY FOR AT LEAST THE NEXT 3 TO 4 DAYS. AS FOR HIGHLIGHTS...AM CONTINUING THE RED FLAG WARNING INTO THIS EVE AS BEFORE...AS MORE AREAS THAN NOT ARE VERY NEAR OR A LITTLE OVER CRITICAL THRESHOLDS. UPGRADED EXISTING WATCH FOR FRI TO RED FLAG WARNING AND ADDED FIRE ZONE 104...MAINLY WEST AND CENTRAL PORTIONS...LARGELY BASED ON HOW FAR E DRYLINE PROGRESSED TODAY. SEE NO REASON FOR IT NOT TO GET AT LEAST AS FAR E AS CLAYTON FRI AFTN...MAIN REASON THAT ZONE ADDED. STILL BELIEVE MOST OF LOWER TERRAIN OF 101 WILL BE MARGINAL AT MOST FOR CRITICAL CONDITIONS FRI AFTN...BUT HIGHER TERRAIN THERE SHOULD DO BETTER AND WITH DEGREE OF DRYNESS AND HEAT FELT IT BEST TO UPGRADE THAT ZONE ALONG WITH THE REST. ALSO HOISTED FIRE WX WATCH FOR SAT AFTN AND EARLY EVE FOR 102 THROUGH 104...107 AND WESTERN PART OF 108. 43 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ101>103-105>107-109. FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES...NMZ102>104-107-108. RED FLAG WARNING FROM 1 PM TO 8 PM MDT FRIDAY FOR THE FOLLOWING ZONES...NMZ101>105. && $$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
119 PM MDT WED JUN 19 2013 .UPDATE... SHARPENING DRYLINE OCCURRING OVER THE EASTERN PLAINS AS LOW LEVEL MOIST EASTERLY FLOW IS MUCH STRONGER THAN MODEL GUIDANCE SHOWED FROM YESTERDAY. THIS WILL LEAD TO SOME STRONG TO LOCALLY SEVERE CONVECTION OVER THE FAR EASTERN COUNTIES WHERE SPC SLIGHT RISK HAS EXPANDED TO LINE UP WITH DEVELOPING CONVECTION AND VERY STRONG INSTABILITY. ALL THAT NEEDS TO HAPPEN NOW IS LIFT WHICH IS SHOWN BY THE 16Z HRRR TO OCCUR BETWEEN 20Z AND 21Z. UPDATED TO RAISE POPS AND INCLUDE SEVERE WORDING ALONG THE TX STATE LINE. GUYER && .PREV DISCUSSION...1141 AM MDT WED JUN 19 2013... .AVIATION... 18Z TAF CYCLE MAIN AVIATION THREATS TODAY WILL BE FOUND ALONG THE DRYLINE WHICH IS EXPECTED TO BE FOUND ACROSS THE EASTERN PLAINS. STORMS SHOULD FIRE UP ALONG THIS BOUNDARY AND THEN MOVE TOWARDS THE NORTHEAST. ROW AND TCC HAVE THE BEST CHANCE OF STORM IMPACTS. WIND IS A BIG THREAT AND HAVE INCLUDED BLOWING DUST AT ROW. CANT RULE OUT A DRIER SHOWER AND WIND IMPACTING LVS BUT MORE POTENTIAL SOUTH AND EAST. TURBULENT MIXING AND MODERATE TO STRONG WINDS WILL BE FOUND ELSEWHERE THROUGH EARLY EVENING. SIMILAR SCENARIO FOR THURSDAY ALTHOUGH THERE IS SOME POTENTIAL FOR THE DRYLINE TO BE SHUNTED A LITTLE FURTHER WEST BUT NOT BY MUCH. 50 .PREV DISCUSSION...318 AM MDT WED JUN 19 2013... THE LATEST WATER VAPOR SATELLITE IMAGERY SHOWS THE PACIFIC DRY SLOT OVER SOCAL...AZ AND NW MEXICO POISED TO PUNCH INTO OUR AREA TODAY AS AN UPPER LEVEL LOW/TROUGH TRANSITIONS FURTHER INLAND ACROSS THE PACIFIC NW. VERY DRY AIR IS ALREADY PUSHING INTO WESTERN PORTIONS OF THE AREA WHERE DEWPOINT 24HR CHANGE VALUES ARE AN AVERAGE -10...WITH THE LATEST OBSERVED VALUES IN THE SINGLE DIGITS AND LOW TEENS. THIS VERY DRY AIRMASS IS CONTRASTED WITH DEWPOINT TEMPS IN THE 50S TO NEAR 60 EAST OF THE CENTRAL MOUNTAIN CHAIN WHERE GULF MOISTURE WILL LINGER FOR MUCH OF THE DAY AND ACT AS FUEL FOR SHOWERS AND THUNDERSTORMS BY AFTERNOON. THE DRY SLOT IS FORECAST TO PUSH EAST TODAY...WITH LOW LAYER MOISTURE ACROSS CENTRAL AREAS MIXING-OUT QUICKLY AND A DRY LINE SHARPENING UP ACROSS THE HIGHLANDS AND EASTERN PLAINS. AFTERNOON AND EVENING CONVECTION IS ANTICIPATED...ALTHOUGH ISOLATED...ALONG AND EAST OF THE DRY LINE. 00Z NAM12 FORECAST SBCAPE OF 3000-3500 J/KG WITH 0-6KM BULK SHEAR OF 35-45KTS...INDICATING AN ATMOSPHERE CAPABLE OF SUPPORTING SUPERCELLS. CRITICAL FIRE WEATHER CONDITIONS ARE FORECAST WEST OF THE DRYLINE...PUSHING INTO THE EASTERN PLAINS LATE IN THE DAY (SEE DETAILS IN FIRE WX DISCUSSION BELOW). BREEZY TO LOCALLY WINDY CONDITIONS ARE EXPECTED AREAWIDE THIS AFTERNOON AND EVENING...ESPECIALLY WEST OF THE DRY LINE WITH DEEP LAYER MIXING FORECAST. SOME BLOWING DUST IS POSSIBLE BY LATE AFTERNOON ...BUT HARD TO SAY WHERE WITH WIND SPEEDS PERHAPS JUST SHY OF LOWER THRESHOLDS. THE NORTHWEST PLATEAU AND THE ABQ WEST MESA LOOK TO HAVE THE BEST SHOT...BUT VISIBILITIES LIKELY TO STAY AT 6 MILES OR HIGHER. MORE CRITICAL FIRE WEATHER CONDITIONS POSSIBLE THURSDAY FOR MUCH OF THE NORTH AND WEST AS THE DRY SLOT PERSISTS OVER THE AREA. CHANCES FOR SHOWERS AND THUNDERSTORMS ON THURSDAY WILL BE CONFINED TO THE SOUTH CENTRAL MOUNTAINS AND THE SOUTHEAST PLAINS WHERE MOISTURE WILL LINGER...BUT MID LEVEL WARMING WILL LIMIT THE AVAILABLE POTENTIAL ENERGY AND WETTING RAINS WILL BE HARDER TO COME-BY. SW FLOW ALOFT TO PERSIST THROUGH THE WEEKEND AS THE PACIFIC UPPER LOW MAKES SLOW EASTWARD PROGRESS ACROSS THE NORTHERN ROCKIES AND THE UPPER HIGH BECOMES ESTABLISHED OVER WEST TEXAS. THE GFS CONTINUES TO SHOW MOISTURE ROUNDING THE PERIPHERY OF THE UPPER HIGH AND LAYING-OVER MUCH OF SOUTHERN AND EASTERN NEW MEXICO WITH DRY AIR PERSISTING ACROSS MUCH OF THE NORTH. POPS HAVE BEEN CONFINED MORE TO THE EAST AND SOUTH WITH THE LATEST MODEL RUNS NOT SO ENCOURAGING FOR PRECIP HERE IN THE ABQ METRO. THE MODELS CONTINUE TO SHOW THE UPPER HIGH DRIFTING NORTH ACROSS NM AND BECOMING ANCHORED OVER COLORADO BY THE MIDDLE OF NEXT WEEK WITH DEEP EASTERLY FLOW PREVAILING ACROSS NM. HOWEVER...THE DOMINANT UPPER HIGH LOOKS TO KEEP TROPICAL MOISTURE WELL SOUTH OF THE FORECAST AREA. NO BIG CHANGES TO FORECAST TEMPS THIS CYCLE WITH ABOVE NORMAL HIGHS AND LOWS PERSISTING THROUGH THE NEXT 7 DAYS. 11 .FIRE WEATHER... ...CRITICAL FIRE WEATHER CONDITIONS MOST AREAS EXCEPT EXTREME EASTERN PLAINS TODAY AND THURSDAY. CRITICAL CONDITIONS TO CONTINUE WESTERN HIGH TERRAIN AND NORTHEAST HIGHLANDS THROUGH THE WEEKEND... FEW CHANGES MADE TO FORECAST PACKAGE IN THE SHORT TERM. POTENT UPPER LEVEL LOW MOVING NEARING THE PACIFIC NORTHWEST COAST WITH RELATIVELY STRONG JET AND DRY SLOT AT THE BASE OF THE TROUGH. SECOND JET MAX AND BROADER AREA OF DRY AIR STRETCHED ACROSS ARIZONA AND INTO NW NEW MEXICO. CIRA LAYERED PW PRODUCT DEPICTS VERY DRY AIR AT BOTH 850 TO 700MB AND 700 TO 500 MB LAYERS. AS THE PACIFIC TROUGH APPROACHES... THE UPPER RIDGE HAS MOVED TO THE EAST AND WEAKEN A BIT. MODELS INDICATE DEEPER MIXING TODAY AND SOUTHWEST WINDS WILL STRENGTHEN STEADILY...ESPECIALLY OVER HIGHER TERRAIN. THUS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED TO DEVELOP BY MID DAY AND EXPAND IN COVERAGE THROUGH THE AFTERNOON. SUPER HAINES PROBABLE ACROSS WESTERN ZONES. WITH PERSISTENT MOIST SOUTH TO SOUTHEAST FLOW INTO THE EASTERN PLAINS...MINIMUM RH VALUES ARE EXPECTED TO REMAIN ABOVE 15 PERCENT WITH ISOLATED THUNDERSTORMS. SOME OF THESE STORMS COULD BE OF THE DRY VARIETY GENERALLY ALONG THE NORTHEAST AND CENTRAL HIGHLANDS. OVERNIGHT RH RECOVERIES TO BE POOR WESTERN AND CENTRAL ZONES. SIMILAR SITUATION ON THURSDAY AS HEIGHTS CONTINUE TO DECREASE AND THE GRADIENT STRENGTHENS A BIT OVER THE STATE. UPPER LEVEL HIGH CENTERED OVER WEST TEXAS WITH MOIST SOUTHERLY LOW LEVEL FLOW EXTREME EAST. WILL LEAVE FIRE WEATHER WATCH IN PLACE...BUT DECREASED DEWPOINTS ALL LOCATIONS...INCLUDING THE EAST SUCH THAT THE WESTERN PORTIONS OF ZONES 104 AND 108 LOOK TO REACH CRITICAL CRITERIA AND MAY NEED TO BE ADDED. SUPER HAINES ONCE AGAIN ACROSS WESTERN ZONES AND NORTH CENTRAL ZONES AS WELL. UPPER HIGH TO REMAIN OVER WEST TEXAS FRIDAY THROUGH SUNDAY. PREVIOUSLY...EXTENDED MODELS DEPICTED A NORTHWARD FLUX OF MOISTURE OVER THE STATE SUPPORTING SLIGHT CHANCES OF WETTING RAIN CENTRAL AND EASTERN ZONES. HOWEVER...LATEST GFS IS DRIER WITH CONTINUED SOUTHWEST FLOW AND MOIST RETURN FLOW LIMITED TO THE SOUTHEAST AND EXTREME EAST CENTRAL PLAINS. THUS DEWPOINTS AND POPS WERE TRIMMED BACK ACROSS THE NORTHWEST AND CENTRAL ZONES WITH SLIGHT CHANCES FOR WETTING RAIN REMAINING SOUTH AND SOUTHEAST ZONES. LIMITED AREAS OF CRITICAL FIRE WEATHER CONDITIONS...MAINLY WESTERN HIGH TERRAIN AND NORTHEAST HIGHLANDS... WITH SUPER HAINES WEST AND NORTH ARE POSSIBLE EACH DAY. EXTENDED MODELS BUILD THE UPPER HIGH OVER NEW MEXICO BY MID WEEK... WITH VERY DRY CONDITIONS PERSISTING BUT LIGHTER WINDS. 05 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ101>109. FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR THE FOLLOWING ZONES...NMZ101>103-105>107-109. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1151 PM MDT TUE JUN 18 2013 .AVIATION... 06Z TAF CYCLE CONVECTION ACROSS NE NM EXITED THE AREA LATE THIS EVENING. APPEARS THAT A BOUNDARY HAS MOVED NWWD THRU KSAF...BUT CONFIDENCE REMAINS LOW THAT A CANYON WIND WILL DEVELOP IN THE ABQ AREA TONIGHT DUE TO THE LACK OF CONVECTION FARTHER SOUTH ACROSS THE EASTERN PLAINS. HAVE REMOVED THE EAST WIND IN THE ABQ TAF FOR NOW...BUT IT BEARS WATCHING...AS A MODERATE PRESSURE GRADIENT REMAINS IN PLACE. OTHERWISE...CANT RULE OUT SOME LOW CIGS DEVELOPING ACROSS THE NORTHEAST PLAINS AFTER 09Z...ESPECIALLY IN AREAS THAT RECEIVED APPRECIABLE RAINFALL. BREEZY TO WINDY CONDITIONS WILL DEVELOP LATE WEDNESDAY MORNING...WITH GUSTS BETWEEN 35 AND 40KTS POSSIBLE THROUGH EARLY EVENING. SOME MODELS ARE INDICATING CONVECTION REDEVELOPING WEDNESDAY EVENING ACROSS THE FAR EASTERN PLAINS. HOWEVER...HAVE NOT INSERTED A VCTS MENTION ATTM AS CONFIDENCE IS LOW THAT ANY TAF SITE WILL BE IMPACTED...THOUGH TCC AND ROW HAVE THE BEST CHANCES. 34 && .PREV DISCUSSION...926 PM MDT TUE JUN 18 2013... ALLOWED SEVERE THUNDERSTORM WATCH TO EXPIRE AS SCHEDULED WITH STORMS JUST IN UNION COUNTY AT THIS TIME. JURY STILL OUT ON WHETHER WE WILL SEE MUCH OF AN EAST WIND INTO THE RGV LATER TONIGHT...SETUP DIFFERENT THAN LAST NIGHT. RUC13 HAS BEEN BACKING OFF ON A STRONG GRADIENT UNTIL AFTER MIDNIGHT OR EVEN TOWARDS SUNRISE. WILL KEEP MONITORING. ZFP ALREADY OUT. .PREV DISCUSSION...307 PM MDT TUE JUN 18 2013... ...SEVERE THUNDERSTORM WATCH 325 IN EFFECT UNTIL 9 PM MDT... STORM COVERAGE IS MUCH MORE LIMITED TODAY AS POTENT DRY AIR ALOFT MOVES OVER THE REGION ON INCREASING SOUTHWESTERLY FLOW. LOW LEVEL MOISTURE DID MAKE IT ALL THE WAY TO THE DIVIDE BUT IT IS SHALLOW AND WILL CONTINUE MIXING OUT THIS AFTERNOON. THIS GRADIENT ACROSS THE AREA ALONG WITH AFTERNOON HEATING AND TOPOGRAPHIC FORCING WILL SET THE STAGE FOR SEVERE STORMS OVER THE NE PLAINS. LATEST RADAR TRENDS SHOW A POTENTIAL SEVERE STORM WEST OF RATON...AND THIS IS EXPECTED TO CONTINUE THROUGH THE EVENING AS THE ATMOSPHERE BECOMES MORE UNSTABLE. RAISED POPS FOR THE NE AND EAST CENTRAL PLAINS AND LOWERED A LITTLE FARTHER WEST. WEDNESDAY WILL BE AN UGLY FIRE DANGER DAY ACROSS THE REGION WITH DEEP MIXING TAPPING VERY DRY AIR LEADING TO HOT...BREEZY/WINDY... AND UNSTABLE CONDITIONS. 700MB TEMPS WILL BE NEAR +18C WHICH IS NOT AS WARM AS WHAT WE EXPERIENCED LAST WEEK HOWEVER IT IS STILL WELL ABOVE NORMAL. TOSSED IN SOME SYNOPTICALLY DRIVEN BLOWING DUST INTO THE GRIDS FOR A FEW CENTRAL AND WESTERN LOCALES. ANY STORMS WILL BE FOCUSED ACROSS THE PLAINS AND EVEN THERE EXPECT MOSTLY DRY AND GUSTY ACTIVITY. THURSDAY WILL BE SIMILAR TO WEDNESDAY EXCEPT MORE MOISTURE WILL TRICKLE NORTH ACROSS THE SE HALF OF THE AREA. RAISED POPS JUST A TAD FARTHER NORTH AS THE 12Z NAM IS BULLISH ON DEVELOPING ACTIVITY UP TO THE I-40 CORRIDOR. TEMPS WILL REMAIN HOT AND WINDS ALOFT WILL STAY STRONG SO BREEZY CONDITIONS CAN BE EXPECTED. ANY SHOWERS/STORMS THAT GET GOING WILL HAVE POTENTIAL TO PRODUCE STRONG OUTFLOW WINDS. QUITE A LARGE AMOUNT OF UNCERTAINTY REMAINS WITH MEDIUM/EXTENDED RANGE GUIDANCE FOR FRIDAY THRU EARLY NEXT WEEK. THE GFS ENSEMBLE PWAT SHOWS A LARGE SWATH OF 1-2 STDEV BELOW CLIMO VALUES FROM THE NORTHERN BAJA REGION ACROSS THE GREAT BASIN...WITH NEAR CLIMO VALUES FOR NM. THE ECMWF IS SIGNIFICANTLY DRIER THRU THIS PERIOD WITH THE UPPER RIDGE AXIS STRETCHING FROM WSW TO ENE ACROSS NORTHERN MEXICO. THIS SHUTS OFF ANY STREAM OF MOISTURE SLIDING INTO OUR AREA THRU ALL OF NEXT WEEK WITH A 598DM RIDGE BUILDING RIGHT OVER NORTHERN NM AND SOUTHERN CO. THIS WOULD LEAD TO WELL ABOVE NORMAL SCORCHING TEMPS ONCE AGAIN. THE GFS HOWEVER DOES TAKE A PIECE OF THE CURRENT TROPICAL DISTURBANCE OVER SOUTHERN MEXICO AND LIFTS IT NORTH WITH THE RIDGE FARTHER EAST. FOR NOW WILL SIDE WITH THE DRIER SOLUTION AND KEEP POPS VERY LOW IN THE EXTENDED. GUYER .FIRE WEATHER... ...CRITICAL FIRE WEATHER PERIOD NEXT FEW DAYS... MODEL GUIDANCE HAS SUGGESTED A LITTLE STRONGER FLOW FOR PORTIONS OF THE FORECAST AREA WEDNESDAY SO RAISED SPEEDS SLIGHTLY BUT PRETTY SIMILAR TO ORIGINAL LEVELS. THE HIGHER RIDGES AND AREAS NEAR THE AZ/CO STATE LINES AS WELL AS TO THE LEE OF THE CENTRAL MOUNTAINS WILL BE FAVORED FOR THE STRONGEST WINDS. LATEST MODEL GUIDANCE ALSO SUGGEST THE STRONGEST WINDS ALOFT WEDNESDAY NIGHT INTO THURSDAY SO BUMPED UP WIND SPEEDS ACCORDINGLY. GETTING MORE CRITICAL FIRE WEATHER CONDITIONS FOR THURSDAY. ONLY FLY IN THE OINTMENT IS THE 12Z NAM/S DEPICTION OF MID LEVEL MOISTURE FLOWING UP FROM MEXICO THURSDAY AFTERNOON. OTHER MODELS NOT AS AGGRESSIVE. COULD BE A WILD AND WOOLLY DAY WITH A MIX OF STANDARD RED FLAG CONDITIONS PLUS DRY MICROBURST WINDS DUE TO DRIER STORMS. WILL MONITOR THAT TREND ACCORDINGLY. WILL UPGRADE WATCH TO A WARNING FOR THE ENTIRE FORECAST AREA EXCLUDING AREAS NEAR TO THE TEXAS STATE LINE DUE TO HIGHER RH THERE WEDNESDAY. WILL ISSUE A WATCH FOR THE WESTERN TWO THIRDS OF THE FORECAST AREA ON THURSDAY. GOING TO BE ON THE SAFE SIDE FOR BOTH DAYS. AS FAR AS REST OF TODAY...LOOKING AT SOME DRIER STORMS ACROSS THE NORTH CENTRAL MOUNTAINS AS THE DRY AIR RAPIDLY PUSHES FROM WEST TO EAST. THESE STORMS WILL TEND TO BE FAST MOVING. THE WETTER STORMS WILL BE FOUND ACROSS THE EASTERN PLAINS...ESPECIALLY FAVORING THE NORTHEAST. UPPER FLOW WILL INCREASE OVER NORTHERN AND CENTRAL NEW MEXICO TONIGHT AS THE UPPER RIDGE SLIDES SLIGHTLY TO THE EAST. TEMPERATURES WILL BE ABOVE NORMAL. THE MID LEVEL DRY INTRUSION WILL FILTER FURTHER OVER THE FORECAST AREA ALTHOUGH ABUNDANT LOW LEVEL MOISTURE WILL TRY TO PUSH BACK TO THE WEST SIMILAR TO LAST NIGHT BUT NOT AS AGGRESSIVE. HUMIDITY RECOVERIES WILL BE VERY POOR NEAR TO THE AZ STATE LINE...POOR BETWEEN THE CONTINENTAL DIVIDE TO RIO GRANDE VALLEY AND THEN MODERATE TO GOOD FURTHER EAST. EVEN EXCELLENT NEAR THE TEXAS STATE LINE. WEDNESDAY WILL BE A HIGHER END CRITICAL DAY DUE TO THE TIME OF YEAR AND COMBO WIND/LOW RH/ABUNDANT TURBULENT MIXING AND QUITE A BIT OF SUNSHINE. SUN ANGLES ARE GETTING TO BE QUITE STEEP AND THE MID LEVEL DRY INTRUSION IS EXPECTED TO BE QUITE STRONG AS IT PUSHES FURTHER EASTWARD OVER THE STATE. SUPER HAINES VALUES ARE PROJECTED FOR WESTERN AND NORTHERN NEW MEXICO. THE SURFACE WIND FLOW WILL BE HERKY JERKY OR PULSY DUE TO THE TURBULENT MIXING AND ABOVE NORMAL TEMPERATURES. MIXING HEIGHTS ARE PROJECTED TO BE ABOVE NORMAL WITH SOME PRETTY STOUT SOUTHWEST TRANSPORT WINDS. SEVERAL HOURS OF SINGLE DIGITS ARE EXPECTED ALONG AND JUST TO THE LEE OF THE CENTRAL MTNS WESTWARD TO ARIZONA. THE HEART OF THE SINGLE DIGIT AREA IN TERMS OF 10 TO 15 HOURS INCLUDES THE NORTHWEST HALF OF THE FORECAST AREA. STORM POTENTIAL...MAINLY OF THE DRIER VARIETY WILL BE FOUND ACROSS THE EASTERN PLAINS AND CANT RULE OUT A ROGUE DRY STORM ALONG THE EAST SLOPES OF THE SANGRES BEFORE THE DRY AIR REALLY PUSHES IN. THE RIDGE WILL NUDGE A LITTLE FURTHER TO THE EAST WEDNESDAY NIGHT AS THE MID LEVEL DRY INTRUSION PROCEEDS OVER THE ENTIRE AREA. TEMPERATURES WILL REMAIN WARMER THAN NORMAL WITH POOR TO VERY POOR RECOVERIES WESTERN TWO THIRDS OR SO. MUCH BETTER RECOVERIES WITH RESIDUAL HIGHER LOW LEVEL MOISTURE WILL BE FOUND NEAR THE TEXAS STATE LINE. THE HIGHER RIDGES SHOULD CONTINUE TO SEE STEADY WIND FLOWS AS THE UPPER FLOW STRENGTHENS SOME. THIS WILL LEAD INTO ANOTHER POTENTIALLY CRITICAL DAY ON THURSDAY. THE UPPER FLOW WILL REMAIN PRETTY STRONG AND FAVOR THE SAME AREAS AS MENTIONED DURING THE OPENING PARAGRAPH. TEMPERATURES WILL REMAIN ABOVE NORMAL ALTHOUGH HUMIDITY VALUES COULD RISE SOME AS COMPARED TO WEDNESDAY/S READINGS. NAM MODEL A LITTLE JUMPY WITH ITS DEPICTION OF A MID LEVEL MOISTURE PUSH FROM MEXICO. THE 12Z MODEL WAS MORE MOIST WHILE THE 18Z IS COMING IN DRIER. IF STORMS DO FORM THEY WOULD BE DRIER AND FASTER MOVING LEADING TO AN ADDITIONAL IGNITION THREAT. EITHER WAY...GETTING ENOUGH CRITICAL WIND SPEEDS COMBINED WITH LOW HUMIDITY AND ABOVE NORMAL MIXING TO WARRANT A FIRE WEATHER WATCH. SEEING A SUPER HAINES SIGNATURE ACROSS THE NORTHWEST THIRD OR SO BUT LESS AREA THAN IS EXPECTED WEDNESDAY. EXTENDED MODELS SUCH AS THE GFS AND ECMWF POINT TOWARDS AN UPPER SOUTHWEST FLOW CONTINUING FRIDAY AND INTO THE WEEKEND. DECIDED TO UP WIND SPEEDS SLIGHTLY FOR FRIDAY AND SEEING SOME LOCALIZED CRITICAL CONDITIONS BUT DOESNT APPEAR TO BE AS STRONG OF A SIGNAL AS THE PREVIOUS DAYS. UPPER FLOW IS DEPICTED TO WEAKEN SOME AS THE PACIFIC TROUGH SHEARS OUT. EXPECTING SOME SORT OF MID LEVEL MOISTURE SEEPAGE FROM MEXICO DURING THIS PERIOD WITH MORE OF A MOISTURE RETURN FROM THE GULF ACROSS THE SOUTHEAST AND EAST CENTRAL PLAINS. THE WETTER STORMS COULD BE POSSIBLE THERE WHILE THE DRIER VARIETY ELSEWHERE. TEMPERATURES WOULD BE A FEW DEGREES ABOVE NORMAL DURING THIS PERIOD WITH MUCH LOWER HUMIDITY VALUES WEST. CONFIDENCE IN THIS PERIOD IS MODERATE ALTHOUGH LOTS OF UNCERTAINTY ON THE MOISTURE PUSH. 50 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ101>109. FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR THE FOLLOWING ZONES...NMZ101>103-105>107-109. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1105 PM EDT THU JUN 20 2013 .SYNOPSIS... HIGH PRESSURE WILL RETREAT AS THE LINGERING FRONT TO OUT SOUTHEAST NUDGES BACK TO THE NORTHWEST THROUGH THE WEEKEND...BRINGING CLOUDS AND INCREASED CHANCE OF SHOWERS. TYPICAL SUMMER WEATHER IS EXPECTED NEXT WEEK WITH BERMUDA HIGH PRESSURE AND THE PIEDMONT TROUGH BECOMING THE DOMINANT SURFACE FEATURES. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 1045 PM THURSDAY...MODEL CONSENSUS CONTINUES WITH THE STALLED FRONT OFFSHORE FROM THE CAROLINAS...DRIFTING WESTWARD TOWARD THE CAROLINA COASTLINES OVERNIGHT. IT MAY REACH THE OUTER WATERS OF THE COASTAL WATERS WELL AFTER DAYBREAK FRIDAY. THE STUBBORN NOSE OF HIGH PRESSURE RIDGING SOUTHWEST FROM ITS 1030 MB CENTER...WILL HOLD ITS GROUND OVERNIGHT INTO FRIDAY. DRIER AIR WITH DEWPOINTS IN THE 50S ACROSS THE NORTHERN PORTIONS OF THE ILM CWA...RISING INTO THE 60S ACROSS THE SOUTHERN PORTIONS OF THE ILM CWA. DEWPOINTS WILL ONLY MODERATE SOME TONIGHT AS THE SFC HIGH CONTINUES TO WEDGE SOUTHWEST ACROSS THE AREA. MAINLY CIRRUS TO AFFECT THE ILM CWA TONIGHT...WITH MID TO HIGH LEVEL CLOUDINESS ASSOCIATED WITH THE STALLED FRONT POSSIBLY REACHING THE COASTAL COUNTIES DURING THE PRE-DAWN FRI HOURS. PCPN ASSOCIATED WITH THE ADVANCING WESTWARD MOVING FRONT...WILL BE HIGHLIGHTED IN THE LOW CHANCE CATEGORY BY 6 AM FRI...MAINLY OVER THE ADJACENT COASTAL WATERS. FEW TWEAKS TO THE CURRENT MIN TEMP FORECAST CLOSER TO THE COAST...OTHERWISE REMAINDER OF THE TEMP FCST LOOKS AOK. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...DRY HIGH PRESSURE NOSING IN FROM THE NORTHEAST INTO THE CENTRAL CAROLINAS WILL GET PUSHED FARTHER INLAND AS THE LINGERING FRONT TO OUR SOUTHEAST MOVES BACK TOWARD THE COAST. A VERY TIGHT GRADIENT WILL EXIST BETWEEN THE VERY DRY AIR TO THE NORTHWEST AND THE MOISTURE LADEN AIR MASS TO THE SOUTHEAST. PCP WATER VALUES WILL BE DOWN TO A HALF INCH IN CENTRAL NC BUT WILL BE UP TO 2 INCHES ALONG COASTAL SC. THIS LINGERING BOUNDARY WILL RETURN TO THE COAST AS IT GRADUALLY WEAKENS THROUGH THE WEEKEND. INITIALLY IT WILL SPREAD CLOUDS OVER THE COASTAL AREAS BUT THROUGH THE DAY ON FRI THE CLOUDS WILL SPREAD FURTHER INLAND. LOOKS LIKE THE BEST MOISTURE RETURN AND CONVERGENCE WILL BE CLOSER TO THE SC COAST ON FRI AS WINDS SHIFT TO THE E-SE THROUGH DAY. BY SATURDAY THE BOUNDARY WILL MOVE FAR ENOUGH INLAND WITH WINDS COMING AROUND TO THE EAST TO SOUTHEAST OVER MOST OF AREA WITH DEEPER MOISTURE MAKING ITS WAY IN. DEEP MOISTURE AND WEAK STEERING FLOW COULD POSE A FLOOD THREAT BUT MOST MODEL QPF HAS BACKED OFF OF TOTAL AMOUNTS. SOUNDINGS AND MOISTURE PROFILES SUGGEST A HUGE INCREASE IN MOISTURE THROUGH THE MID TO UPPER LAYERS ESPECIALLY AND MAY SEE MUCH MORE IN THE WAY OF CLOUDS THAN PCP. FLOODING MAY BE VERY LOCALIZED. TEMPERATURES WILL REMAIN BELOW CLIMO THROUGH THE PERIOD WITH CLOUDS AND PCP HOLDING THEM DOWN ALONG THE COAST AND SLIGHTLY COOLER AIR MASS INLAND. MAX TEMPS WILL REMAIN IN THE LOW TO MID 80S MOST PLACES. LOWS WILL RUN A LITTLE CLOSER TO CLIMO...THOUGH STILL UNDER. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 300 PM THURSDAY...BIGGEST QUESTION MARK DURING THE LONG TERM CONTINUES TO BE HOW A DECAYING COASTAL TROUGH/REMNANT FRONT...WHICH WILL LIFT BACK NORTH ACROSS THE AREA SUNDAY...WILL IMPACT THE AREA. WHILE ECMWF CONTINUES TO BE THE DRIEST OF THE MODELS...IT HAS TRENDED WETTER...AND IT NOW LOOKS LIKE SUNDAY WILL BE PRETTY CLOUDY WITH SHOWERS/TSTMS...ESPECIALLY THE EASTERN HALF OF THE AREA. STILL MUCH UNCERTAINTY THOUGH SINCE THE BOUNDARY IS WEAKENING...AND THE ANTECEDENT AIRMASS LOOKS QUITE DRY. BUT WILL INCREASE POP TO MEDIUM-CHC AS THE BOUNDARY LIFTS NORTH INTO AN AIRMASS WITH PWATS RISING TO 1.75 INCHES. BEHIND THIS BOUNDARY...MORE TYPICAL SUMMERTIME PATTERN SETS UP FOR THE REMAINDER OF THE EXTENDED WITH BERMUDA HIGH ANCHORING OVER THE WESTERN ATLANTIC OCEAN AND MID-LEVEL RIDGING BULGING ACROSS THE SOUTHERN TIER. THIS WILL PUMP CONSIDERABLE MOISTURE INTO THE REGION AND WILL SUPPORT AT LEAST SCATTERED SEA BREEZE AND PIEDMONT TROUGH CONVECTION EACH DAY NEXT WEEK. BY WED/THU...LARGE UPPER RIDGE EXPANDS ACROSS THE SOUTHWEST...WEAKENING THE RIDGE IN THE EAST...AND MORE WIDESPREAD CONVECTION IS POSSIBLE DURING THAT TIME. TEMPS WILL RISE SLOWLY THROUGH THE PERIOD...WITH SUNDAY BEING THE COOLEST DAY WITH TEMPS SLIGHTLY BELOW CLIMO. A WARMING TREND COMMENCES THEREAFTER AS TEMPS RISE TO ABOVE NORMAL MUCH OF NEXT WEEK. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... AS OF 00Z...EXPECT VFR THROUGH THE VALID PERIOD WITH THE EXCEPTION OF POTENTIAL FOR MVFR OVERNIGHT/EARLY MORNING DUE TO STRATUS. VFR PREVAILS ACROSS THE AREA THIS EVENING WITH EAST-NORTHEAST WINDS AOB 8 KTS AND LOCALLY HIGHER GUSTS ALONG THE COAST...WHICH ARE EXPECTED TO TAPER OFF INTO THE EVENING HOURS. GIVEN LATEST ANALYSIS ALONG WITH PREVIOUS ASSESSMENT...WILL CONTINUE POTENTIAL FOR LOW STRATUS ALONG THE COAST LATE OVERNIGHT CREATING MVFR/POSSIBLE BRIEF IFR. AFTER DAYBREAK...VFR WILL PREVAIL WITH INCREASING CLOUDS THROUGHOUT THE DAY AS A FRONT OF THE SOUTHEASTERN SEABOARD BEGINS TO BACK NORTHWEST TOWARDS THE AREA. ISOLATED TO SCATTERED SHOWERS FORECASTED FOR THE AFTERNOON/EARLY EVENING HOURS...ESPECIALLY ALONG THE COAST...WITH EAST-NORTHEAST WINDS AOB 10 KTS. EXTENDED OUTLOOK...MODERATE CHANCE OF SHOWERS THROUGH TUESDAY AS A STALLED FRONT LINGERS NEAR THE COAST. BEST CHANCE FOR PRECIP WILL BE IN THE AFTERNOON...WITH LOCAL MVFR/IFR CONDITIONS POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM THURSDAY...WEDGE OF HIGH PRESSURE ACROSS THE INLAND CAROLINAS...AND THE STALLED FRONT OFFSHORE AND PARALLEL TO THE CAROLINA COASTLINES...WILL COMBINE TO PRODUCE A NE-E WIND 15 TO 20 KT FOR MUCH OF THE OVERNIGHT PERIOD...POSSIBLY DIMINISHING TO AROUND 15 KT BY DAYBREAK FRIDAY. DURING THE PRE-DAWN FRI HOURS...THE STALLED FRONT WILL BEGIN TO ADVANCE WESTWARD AND POSSIBLY REACH THE OUTER WATERS OF THE COASTAL WATERS WELL AFTER DAYBREAK FRI. LATEST HRRR SFC WIND OUTPUT FOLLOWED CLOSELY. FIVE TO 6 SECOND AVERAGE PERIOD WIND DRIVEN WAVES WILL DOMINATE SIGNIFICANT SEAS. EXPECT 3 TO 5 FOOT SIG SEA HEIGHTS FOR THE REMAINDER OF THE OVERNIGHT...WITH 2 TO 4 FT SOUTH OF CAPE FEAR TO MYRTLE BEACH WHICH LIES IN A PROTECTIVE SHADOW RESULTING FROM NE-E WIND DRIVEN WAVES MOVING ACROSS FRYING PAN SHOALS. WILL CONTINUE THE BORDERLINE SCEC THROUGH 6 AM. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...NORTHEAST WINDS WILL DIMINISH TO UNDER 15 KTS FRI AS LINGERING SURFACE BOUNDARY EAST TO SOUTHEAST OF THE WATERS MOVES CLOSER AND SURFACE HIGH RETREATS A LITTLE FARTHER INLAND. AS WINDS LIGHTEN THEY WILL VEER AROUND BECOMING MORE EASTERLY AND EVENTUALLY SOUTHEAST AS BOUNDARY SHIFTS CLOSER TO THE COAST. ONCE THE WEAKENING FRONT/TROUGH MOVES INLAND BY SATURDAY THE WINDS WILL BECOME MORE SOUTHEASTERLY. EXPECT A SPIKE IN WINDS AND A GREATER E-SE FLOW CLOSE TO THE SHORE EACH AFTERNOON. SEAS 3 TO 4 FT FRI DECREASE TO 2 TO 3 FT ON SAT AND UNDER 3 FT SAT NIGHT AS WINDS LIGHTEN WITH A SLIGHTLY LONGER PERIOD UP TO 10 SEC EAST-SOUTHEASTERLY SWELL. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 PM THURSDAY...LIGHT SE WINDS LESS THAN 10 KTS SUNDAY WILL GRADUALLY VEER TO THE SOUTHWEST BY MONDAY AND PERSIST THROUGH THE REMAINDER OF THE PERIOD AS BERMUDA HIGH PRESSURE ANCHORS OFFSHORE. WHILE WIND SPEEDS WILL INCREASE AS THEY TURN TO THE SW...THEY WILL REMAIN ONLY 10-15 KTS MONDAY AND TUESDAY. WHILE A WEAK WIND WAVE CONTRIBUTION WILL EXIST WITHIN THE WAVE SPECTRUM...SEAS BECOME INCREASINGLY SWELL-DOMINATED THROUGH THE PERIOD THANKS TO THE PERSISTENT FETCH AROUND BERMUDA HIGH. WAVE AMPLITUDES WILL BE 1-3 FT SUNDAY...GROWING TO 2-4 FT MONDAY AND TUESDAY. && .TIDES/COASTAL FLOODING... AS OF 300 PM THURSDAY...TIDAL RANGES ARE EXPANDING AS THE FULL MOON APPROACHES THIS WEEKEND. SEVERAL HIGH TIDES THIS WEEKEND MAY REACH MINOR COASTAL FLOODING CRITERIA ALONG THE CAPE FEAR RIVER AT DOWNTOWN WILMINGTON. THIS IS NOT EXPECTED TO BE A MAJOR EVENT...BUT ANYTIME THE RIVER RISES TO MORE THAN 5.50 FEET ABOVE MLLW PROBLEMS DEVELOP ALONG BATTLESHIP ROAD AND NEAR THE U.S.S. NORTH CAROLINA BATTLESHIP MEMORIAL. THIS EVENING`S HIGH TIDE SHOULD FALL SHORT OF 5.50 FEET...BUT HIGH TIDES SATURDAY AND SUNDAY EVENINGS HAVE MUCH BETTER POTENTIAL TO PRODUCE MINOR FLOODING. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...DCH SHORT TERM...RGZ LONG TERM...JDW AVIATION...SGL TIDES/COASTAL FLOODING...TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1233 AM CDT WED JUN 19 2013 .UPDATE... ISSUED AT 1230 AM CDT WED JUN 19 2013 EARLY MORNING RADAR MOSAIC SHOWS THUNDERSTORMS WHICH DEVELOPED ACROSS PARTS OF NORTHWEST SOUTH DAKOTA HAVE DIMINISHED. AN ISOLATED STORM IN THE FAR SOUTHWEST PART OF THE FORECAST AREA CAN NOT BE RULED OUT OVER THE NEXT COUPLE OF HOURS...BUT IT APPEARS THE CHANCES FOR PRECIPITATION ARE DECREASING. MADE SMALL ADJUSTMENTS TO CAPTURE THE LATEST TEMPERATURE TRENDS IN THE UPDATE...OTHERWISE THE FORECAST IS ON TRACK. UPDATE ISSUED AT 916 PM CDT TUE JUN 18 2013 LATEST BOWMAN DOPPLER RADAR SHOWS AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS BEGINNING TO IMPINGE INTO SOUTHWEST HARDING COUNTY IN SOUTH DAKOTA. THE H85-H30 MEAN WIND WOULD CONTINUE TO MOVE THE PRECIPITATION AREA FROM SOUTHWEST TO NORTHEAST THIS EVENING. THE THE LATEST RAP INITIALLY HAS THE AREAL EXTENT OF THE AFOREMENTIONED PRECIPITATION TOO FAR NORTH...AND WILL MAKE ADJUSTMENTS WITH A HEAVIER BLEND OF THE NAM OVERNIGHT. STILL EXPECTING ISOLATED THUNDERSTORMS INTO FAR SOUTHWEST NORTH DAKOTA AS PREVIOUSLY FORECAST...AS A H85-H7 SATURATED POTENTIAL TEMP RIDGE AXIS RESIDES IN CLOSE PROXIMITY IN FAR SOUTHWEST NORTH DAKOTA AND THE ONGOING CONVECTION...ALONG WITH H85-H5 LAPSE RATES OF 7C/KM. THE ACTIVITY SHOULD WEAKEN THEREAFTER...AND HAVE TAPERED OFF POPS TO LESS THAN MEASURABLE INTO SOUTH CENTRAL NORTH DAKOTA OVERNIGHT. ALTHOUGH CLOUD DEBRIS/ACCAS (ALTOCUMULUS CASTELLANUS) SHOULD BE VISIBLE LATER TONIGHT INTO EARLY WEDNESDAY MORNING AS INSTABILITY SHIFTS INTO NORTH DAKOTA. ELSEWHERE...CLOUDS ARE ALSO INCREASING IN NORTHEAST MONTANA AS A CIRRUS CANOPY SHIFTS EAST FROM THE THUNDERSTORMS IN NORTH CENTRAL MONTANA. WILL CONTINUE TO INCREASE CLOUDS OVERNIGHT WEST AND SOUTH CENTRAL. EXPECTATIONS ARE ISOLATED CONVECTION WILL BE CONFINED TO THE SOUTHWEST ZONES OVERNIGHT AND DRY CONDITIONS ELSEWHERE. UPDATE ISSUED AT 624 PM CDT TUE JUN 18 2013 LATEST WATER VAPOR IMAGERY THIS EVENING SHOWS A MID/UPPER LEVEL DISTURBANCE ROTATING THROUGH CENTRAL NORTH DAKOTA AT THIS TIME. VISIBLE SATELLITE IMAGERY AND SURFACE OBS SHOW SCT MID LEVEL CLOUDS STRETCHING FROM ROSEGLEN TO NEAR DICKINSON...WITH A SCT FAIR WEATHER CUMULUS FIELD ACROSS SOUTH CENTRAL AND EAST CENTRAL NORTH DAKOTA. WITH A H7-H5 RIDGE AXIS ANCHORED FROM WILLISTON TO BISMARCK AND INTO SIOUX FALLS SOUTH DAKOTA TONIGHT...EXPECT A DRY NIGHT ALONG AND EAST OF THE AFOREMENTIONED RIDGE AXIS. ATTENTION THIS EVENING AND OVERNIGHT TURNS TO AN UPSTREAM SHORTWAVE OVER SOUTHEAST WYOMING. THIS IS GENERATING THUNDERSTORMS IN THE HIGHER TERRAIN OF WYOMING...WITH A LARGE MID/HIGH LEVEL CLOUD CANOPY EXPANDING OVER EASTERN WYOMING AND SOUTHEAST MONTANA. THIS IS MOVING NORTHEAST AND WILL SLIDE INTO OUR SOUTHWEST ZONES THIS EVENING. THE LATEST RAP ADVECTS SOME LIGHT PRECIPITATION INTO THE FAR SOUTHWEST ZONES TOWARD 06Z. THE 18Z GFS IS MORE ROBUST IN GENERATING A LARGER SWATH OF LIGHT PRECIPITATION LATE TONIGHT THROUGH MID MORNING WEDNESDAY IN SOUTHWEST NORTH DAKOTA AND JUST GRAZING OUR SOUTH CENTRAL ZONES. HOWEVER OTHER MODELS DELAY THE SHOWERS/THUNDERSTORMS WITH THIS SHORTWAVE UNTIL WEDNESDAY AFTERNOON AND EVENING. WILL AWAIT THE 00Z DATA BEFORE MAKING ANY CHANGES BEYOND TONIGHT. WILL ALSO MONITOR THE CONVECTION APPROACHING THE SOUTHWEST THIS EVENING/OVERNIGHT. ONLY UPDATES THIS EVENING WAS TO HOURLY OBS AND TO INCREASE SKY GRID TRENDS IN THE SOUTHWEST AS MENTIONED ABOVE. THE CLOUD DEBRIS MAY MAKE IT INTO SOUTH CENTRAL NORTH DAKOTA BEFORE SUNRISE WEDNESDAY. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 324 PM CDT TUE JUN 18 2013 SURFACE TROUGH AND ASSOCIATED WARM FRONTAL BOUNDARY IN EASTERN MONTANA WILL BE THE FOCUS FOR SCATTERED THUNDERSTORMS LATE TONIGHT AND WEDNESDAY AFTERNOON. ANTICIPATE SOME THUNDERSTORMS WILL FIRE OVER THE HIGHER ELEVATION AREAS IN WYOMING/MONTANA/SOUTH DAKOTA AND DRIFT INTO SOUTHWEST NORTH DAKOTA LATE TONIGHT. ON WEDNESDAY ONE LIMITING FACTOR WILL BE A SLOWING EVOLVING ELEVATED MIXED LAYER THAT MAY CAP THUNDERSTORMS OVER WESTERN NORTH DAKOTA WEDNESDAY AFTERNOON. HOWEVER BELIEVE THE INCREASING LOW LEVEL JET AND SIGNIFICANT CAPE VALUES JUSTIFY SCATTERED THUNDERSTORMS ACROSS WEST AND CENTRAL NORTH DAKOTA WEDNESDAY AFTERNOON. WINDS ON WEDNESDAY SHOULD APPROACH BUT REMAIN BELOW WIND ADVISORY CRITERIA SOUTHWEST...PROBABLY 20 TO 35 MPH. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 324 PM CDT TUE JUN 18 2013 THE MAIN FORECAST ISSUE THROUGH THE LONG TERM PERIOD IS CONVECTIVE TRENDS AND POTENTIAL FOR PERIODS OF STRONG TO SEVERE STORMS...SOME ACCOMPANIED BY HEAVY RAINFALL. THE RUNS OF THE GFS/ECMWF ARE IN GENERAL AGREEMENT WITH A SLOWER PROGRESSION OF A LARGE CLOSED UPPER LOW IN THE PACIFIC NORTHWEST EARLY IN THE PERIOD...WITH THE NAM FASTEST IN BRINGING THE MAIN SYNOPTIC FEATURES EASTWARD. HAVE FAVORED THE GFS/EC SOLUTIONS FOR POPS WEDNESDAY NIGHT AND THURSDAY. THERE IS SOME POTENTIAL FOR AN MCS TO CLIP NORTHWEST COUNTIES LATE WEDNESDAY NIGHT INTO THURSDAY MORNING...FUELED BY A 40-50 KT LOW LEVEL JET. THE MAIN DECISION-MAKING ELEMENT WAS WHEN/WHERE THE STRONG MID-LEVEL CAP WOULD INHIBIT CONVECTION...BECAUSE OTHERWISE PLENTY OF CAPE AND SHEARING FOR SEVERE THUNDERSTORMS. WEDNESDAY EVENING THE AXIS OF THE MID-LEVEL CAP OF 10-14C IS SITUATED OVER WYOMING/EASTERN MONTANA AND NUDGING INTO SOUTH DAKOTA AND FAR SOUTHWESTERN NORTH DAKOTA. THE CAP BUILDS DURING THE EVENING NORTHWARD AND EASTWARD ACROSS THE DAKOTAS. AT THIS TIME IT APPEARS THE BEST CHANCE OF SEVERE THUNDERSTORMS BEGINS IN FAR WESTERN NORTH DAKOTA LATE EVENING WEDNESDAY OR EARLY MORNING THURSDAY...WITH SEVERE THUNDERSTORMS POSSIBLE. THE STORMS MOVE EASTWARD INTO CENTRAL NORTH DAKOTA BETWEEN MIDNIGHT AND DAYBREAK THURSDAY MORNING. THURSDAY THE ACCOMPANYING SURFACE FRONT IS PROGGED TO BE ORIENTED NORTH-SOUTH ACROSS CENTRAL NORTH DAKOTA...WITH THE BEST CHANCES OF THUNDERSTORMS IN NORTHWEST AND CENTRAL NORTH DAKOTA THURSDAY MORNING...AND SHIFTING TO CENTRAL NORTH DAKOTA THURSDAY AFTERNOON AND INTO THURSDAY EVENING. THE BEST CHANCE FOR SEVERE WEATHER THURSDAY IS IN THE NORTHWEST AND CENTRAL. FRIDAY AND FRIDAY NIGHT LOOKS TO BE THE TIME FRAME FOR WIDESPREAD MODERATE TO HEAVY RAINFALL. CONTINUED UPPER LEVEL ENERGY AND LOW LEVEL MOISTURE WITH A SURFACE LOW BECOMING ESTABLISHED OVER THE CENTRAL PLAINS AND OVERRUNNING PRECIPITATION NORTH OF THE LOW IS FAVORED FOR THE HEAVIEST RAINFALL. WIDESPREAD RAINFALL AMOUNTS OF 1 TO 2 INCHES IS POSSIBLE. THE MODELS CONTINUE TO DEPICT THE UPPER LEVEL LOW MAINTAINING ITS PRESENCE OVER THE ROCKIES WITH SOUTHWEST FLOW OVER NORTH DAKOTA WITH MULTIPLE UPPER LEVEL ENERGY IMPULSES MOVING ACROSS THE STATE IN THE UPPER FLOW. THE MODELS BRING THE UPPER LOW ACROSS THE STATE SUNDAY. PRECIPITATION CHANCES LESSEN MONDAY AND TUESDAY...BUT ZONAL FLOW ALOFT WOULD ALLOW SOME UPPER LEVEL IMPULSES TO SUPPORT SHOWERS AND THUNDERSHOWERS INTO EARLY NEXT WEEK. TEMPERATURES ARE EXPECTED TO BE SEASONABLE THROUGH THE PERIOD...WITH HIGHS IN THE 70S/LOWER 80S...AND LOWS GENERALLY IN THE 50S AND 60S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1230 AM CDT WED JUN 19 2013 VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE TAF PERIOD. THERE WILL BE INCREASING MID AND HIGH CLOUDS EARLY THIS MORNING...WITH SCATTERED CUMULUS POSSIBLE DURING THE DAY WEDNESDAY. THERE IS A CHANCE OF THUNDERSTORMS DURING THE LATE AFTERNOON INTO THE EVENING WEDNESDAY AS A WARM FRONT BEGINS TO APPROACH THE REGION. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CK SHORT TERM...WAA LONG TERM...JV AVIATION...CK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
723 PM EDT THU JUN 20 2013 .SYNOPSIS... HIGH PRESSURE AT THE SURFACE AND ALOFT...TOGETHER WITH WEAK FLOW REMAINS IN CONTROL THROUGH THE WEEKEND. HOWEVER...MOUNTAIN CONVECTION POSSIBLE THROUGH THE WEEKEND. && .NEAR TERM /THROUGH FRIDAY/... STILL ON TRACK FOR A FEW AFTN SHRA/TSRA TO DEVELOP ON THE RIDGES ON WEAK SE FLOW...AIDED BY ELEVATED HEAT SRC. LATEST HRRR SEEMS TO HAVE A GOOD HANDLE ON THIS AND USED IT TO FINE TUNE POPS WITH BULLSEYE CHC ACROSS RIDGES IN CENTRAL MTNS ACROSS EXTREME E FAYETTE AND NICHOLAS CO AND INTO POCAHONTAS. WITH SCHC POPS ACROSS REMAINDER OF RIDGES DOWN TO SW VA. PEAK COVERAGE ARND 21Z...WANING BY 00Z. ELSEWHERE LACK OF A FORCING MECHANISM AND CAP KEEPS THINGS DRY. DID ALLOW FOR SOME SCHC POPS ADJ OF THE RIDGES IN CASE THINGS TRY TO SLIDE OFF RIDGES. OVERALL VERY WEAK FLOW SHOULD MEAN MAINLY RIDGE TOP HUGGERS THOUGH. WILL HAVE TO WATCH FOR VERY ISO HVY RAINFALL AMNTS FROM NEAR STATIONARY MOVEMENT...ALTHOUGH PWATS ARE BLO AND INCH. MDLS SHOW QUITE A BIT OF H85 MOISTURE LINGERING OVERNIGHT ACROSS THE MTNS WITHS SOME H925 MOISTURE ALONG E SLOPES. THINK MOST OF THIS DISSIPATES WITH LOSS OF HEATING...SAVE FOR THE E SLOPES LLVL MOISTURE. SHOULD BE ANOTHER GOOD FG NIGHT FOR RVR VALLEYS...ESPECIALLY ACROSS KANAWHA...TUG FORK...GUYANDOTTE AND OF COURSE TYGART. MORNING FG BURNS OF BY 13Z WITH MORE OF THE SAME FOR AFTN AS TDY. HAVE MAINLY MTN CU FIELDS WHERE LOW CHC POPS WERE INSERTED FOR LATE AFTN SHRA/TSRA. FELT GUIDANCE WAS A COUPLE DEGREES TOO WARM FOR TOMORROW GIVEN RECENT RAINS. STILL HAVE MID/UPR 80S OUTSIDE OF THE MTNS WITH 70S TO LOW 80S IN THE HIGH COUNTRY. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... MAIN MID/UPPER LEVEL FLOW TO REMAIN TO THE NORTH DURING THE SHORT TERM...WITH ANY APPRECIABLE FORCING STAYING OUT OF THE CWA. NOT A LOT OF CHANGES TO THIS PORTION OF THE FORECAST...WITH PEAK HEATING BRINGING THE POTENTIAL FOR A FEW MOUNTAIN SHOWER/STORMS...AND LESS POTENTIAL OVER THE LOWLAND AREAS. STILL DEALING WITH A CAP AROUND 725MB...AND NOT A LOT TO WORK WITH IN TERMS OF AVAILABLE MOISTURE. AGAIN...CONVECTIVE TEMPERATURE SHOULD BE REACHED...AND CANNOT RULE OUT TOWERING CUMULUS COMPLETELY. KEEPING THE TEMPERATURES IN THE UPPER 80S TO AROUND 90 DEGREES FOR THE LOWLANDS...WHILE KNOCKING A FEW OFF THE PACE FOR THE HIGHER ELEVATIONS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... PATTERN REMAINS ON THE WARM SIDE WITH DAYTIME HEATING CHANCES FOR SHOWERS/STORMS CONTINUING. LONG WAVE PATTERN WILL AMPLIFY MID WEEK TOWARDS THE END OF NEXT WEEK WITH A STRONG RIDGE/HEAT WAVE EXPECTED OVER THE INTERMOUNTAIN WEST...AND A TROUGH DIGGING INTO THE GREAT LAKES BY FRIDAY. CPC BRINGS IN HIGHER CHANCES FOR A WETTER TREND FOR THE END OF NEXT WEEK GIVEN THIS RIDGE/TROUGH SYSTEM. UNTIL THEN PRECIPITATION WILL BE HIT OR MISS...WITH BETTER CHANCES IN THE ELEVATED HEAT SOURCE AREAS TO THE EAST. TEMPERATURES REMAIN ABOVE NORMAL. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... FEW SLOW MOVING CONVECTIVE CLUSTERS FROM KBKW VCNTY ON SW TO NR KLNP THROUGH 03Z FRIDAY. MAINLY SHOWERS BUT COULD NOT RULE OUT THUNDER. BRIEF CEILINGS 2 TO 4 THSD FT BKN VCNTY OF THOSE CELLS AND VSBY NEAR 3 MILES. SOME MOISTURE TRIES TO LINGER OVERNIGHT ACROSS THE MTNS AND EASTERN KENTUCKY WHICH MAY LEAVE SOME A FEW CLDS ARND. LOW STRATUS MAY ALSO TRY TO DEVELOP LATE ON SE FLOW ACROSS E SLOPES. HAVE HELD THIS OUT OF KBKW TAF FOR NOW. OTHERWISE...ANOTHER RVR VALLEY FG NIGHT. CONTINUED OUR THINKING THAT THE FOG WILL BE LATER IN FORMING...LESS WIDESPREAD...AND SHORTER IN DURATION. HAVE LIFR FG FOR KPKB...KEKN...AND KCRW OVERNIGHT WITH SOME IFR FG ACROSS KHTS AND MVFR KBKW. THINK KCKB ESCAPES MOST OF THE THE FOG. MORNING FOG LIFTS BY 13Z FOR A RETURN TO VFR CONDITIONS. SAME STORY HOLDS FOR FRIDAY 18Z TO 00Z SATURDAY...THOUGH THINKING HERE IS THAT SOME CONVECTIVE CELLS MAY FORM FURTHER NORTH ALONG THE WV/KY BORDER VICINITY. LEAVING OUT OF KCRW AND KHTS TAFS FOR NOW. SO MAINLY 3 TO 5 THSD FT AGL SCT BUT 2 TO 3 THSD FT BKN AND VSBY NR 3 MILES IN VICINITY OF THAT AFTERNOON AND EVENING CONVECTION. CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY... FORECAST CONFIDENCE: TIMING OF DENSITY AND DURATION OF REDUCED VIS AFTER 06Z MAY VARY. A LATE DAY FRIDAY CONVECTIVE CELL OR SMALL CLUSTER MAY SNEAK FURTHER NORTH THAN FORECAST TOWARD KHTS-KCRW. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE FRI 06/21/13 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H H H H H M M L L L L HTS CONSISTENCY H H H H H H H H H H L L BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H M L L L L L L PKB CONSISTENCY H H H H H H H M L L L L CKB CONSISTENCY H H H H H H H H H H H H AFTER 00Z SATURDAY... IFR/LIFR IN NOCTURNAL FOG LESS WIDESPREAD...BUT STILL POSSIBLE 09Z TO 12Z SATURDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/30/26 NEAR TERM...30 SHORT TERM...26 LONG TERM...26 AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
146 PM EDT WED JUN 19 2013 .SYNOPSIS... HIGH PRESSURE CRUISES WEDNESDAY AND THURSDAY...BEFORE DROPPING ANCHOR IN THE WESTERN ATLANTIC TO BEGIN THE SUMMER SEASON. HIGH RIDGE ALOFT KEEPS DRY CONDITIONS THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 1145 AM UPDATE...STRATUS ERODING RAPIDLY SO THAT MOST OF THIS AFTERNOON WILL SEE LOTS OF SUNSHINE AND WARM TEMPERATURES. STILL WILL LEAVE A SLIGHT CHANCE IN THE MOUNTAINS BEFORE DRY AIR MIXES DOWN LATER AROUND MID AFTERNOON. WILL INCLUDE LOCALLY DENSE FOG TONIGHT. 630 AM UPDATE... SFC FRONT ROUGHLY FROM POCAHONTAS COUNTY SW-WARD TO JUST NORTH OF BKW AT THIS TIME AND WILL CONTINUE A BIT FURTHER SOUTHWARD INTO VIRGINIA BEFORE STALLING LATER THIS MORNING. TWEAKED SKY COVER TO REFLECT QUICKER CLEARING ACROSS SE OHIO AND INTO ADJACENT WEST VIRGINIA. INGESTED RECENT OBS. OTHERWISE...NO MAJOR CHANGES. PREVIOUS DISCUSSION... AT 06Z SFC OBS INDICATE SECONDARY FRONT LOCATED ROUGHLY FROM HTS EAST/NORTHEAST TO NEAR CKB. NEAR AND AHEAD OF IT A FEW SHOWERS AND EVEN ONE THUNDERSTORM HAD REDEVELOPED EARLY THIS MORNING. THE ENHANCEMENT LIKELY DUE TO A VORT MAX...EVIDENT IN WV IMAGERY...MOVING QUICKLY ACROSS NORTH CENTRAL OHIO. ALL IN ALL EXPECT A NICE DAY FOR MOST FOLKS AS THE AFOREMENTIONED FRONT MOVES THROUGH THE AREA...UNDER PARTLY TO MOSTLY SUNNY SKIES BY THE AFTERNOON AND SEASONABLY WARM TEMPS. LARGE SCALE FORCING FOR SUBSIDENCE WILL OVERSPREAD THE FORECAST AREA FROM NW TO SE AS A 500MB S/W TROUGH PUSHES EASTWARD ACROSS AND EXITS TO THE EAST AROUND THE 18Z-21Z TIME FRAME. BY THE AFTERNOON HOURS HOWEVER...THE SFC FRONT BEGINS TO WASH OUT AND AS SFC HIGH PRESSURE REBUILDS TO THE EAST. MODELS IN GOOD AGREEMENT WITH GOOD SFC CONVERGENCE ALONG THE EASTERN HIGH TERRAIN PEAKS AS SFC FLOW ON THE EAST SIDE RETURNS QUICKLY TO THE EAST/SOUTHEAST...WHILE FLOW ON THE WINDWARD SIDE REMAINS NORTH/NORTHWEST. SOME QUESTION AND DOUBT AS TO THE DEPTH OF MOISTURE BEING DEPICTED ON LATEST NAM12 SOUNDINGS HOWEVER...AND LATEST RUC13 SOUNDINGS ARE INDEED MUCH DRYER IN LOWER LEVELS. EVEN WITH THE MORE SATURATED NAM12...PWATS STILL ONLY PROGGED AROUND 0.8IN-0.9IN WITH VERY DRY AIR ALOFT WHICH WOULD SERVE TO LIMIT COVERAGE. PREV FCST HAD A GOOD HANDLE ON THIS AND WILL CONTINUE SLIGHT CHANCE TO LOW CHANCE POPS ESSENTIALLY FROM THE HIGHEST PEAKS AND POINTS SOUTH AND EAST...WITH STORM MOTION TO THE SOUTHEAST. DID INSERT A SLIGHT THUNDER MENTION WITH DECENT INSTABILITY IN THAT AREA. AS SUCH...KEPT CLOUD COVER HIGHER IN THE EASTERN HIGH COUNTRY AS WELL. ALSO NUDGED MAX TEMPS UP AN ADDITIONAL DEGREE OR TWO FOR MOST LOCATIONS PER LATEST PROGGED 925MB AND 850MB TEMPS WITH MOS GUIDANCE SUPPORTING...ALTHOUGH DID KEEP MAX TEMPS IN THE MOUNTAINS JUST A BIT LOWER WITH MORE CLOUDS AND SOME AFTERNOON PRECIP POTENTIAL. OVERNIGHT FORECAST REMAINS VIRTUALLY UNCHANGED FROM PREV SHIFT THINKING...WITH MINS IN THE MID AND UPPER 50S LOWLANDS. WILL HAVE PRECIP ENDING AT 00Z THU IN THE MOUNTAINS. AREAS OF FOG ARE A GOOD BET ONCE AGAIN IN THE LOWLANDS UNDER A MOSTLY CLEAR SKY AND NEAR-CALM WINDS...ALTHOUGH SOME LOWER DEWPOINTS ACROSS SE OHIO AND MORE CLOUD COVER IN THE MOUNTAINS MAY LIMIT COVERAGE IN THOSE AREAS. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... SFC HIGH PRESSURE MOVE OFF SHORE THE NORTHEAST COAST LATE THURSDAY LOSING ITS INFLUENCE WEST OF THE APPALACHIANS. HOWEVER...ABUNDANT LOW LEVEL MOISTURE AND ELEVATED HEAT SOURCES COULD PRODUCE ISOLATED AFTERNOON SHOWERS OR STORMS OVER HIGHER ELEVATIONS THROUGH THE WEEKEND. A MID LEVEL RIDGE MOVES OVERHEAD SATURDAY PROVIDING SOME SUBSIDENCE AND CLEAR SKIES. AFTERNOON CU WILL BE COMMON JUST TO DISSIPATE AFTER SUNSET. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... SURFACE HIGH PRESSURE WILL REMAIN CENTERED ACROSS THE SOUTHEAST STATES...WITH A RIDGE EXTENDING NORTH INTO WEST VIRGINIA. SOUTHERLY WINDS WILL RESULT IN DEW POINTS INCREASING TO THE UPPER 60S AND LOWER 70S. AS A RESULT...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORM WILL BE A POSSIBILITY...MAINLY DURING THE AFTERNOON AND EVENING HOURS. AN UPPER LEVEL TROF AND AN ASSOCIATED COLD FRONT WILL APPROACH FROM THE WEST LATE IN THE PERIOD...RESULTING IN BETTER CHANCES FOR SHOWERS AND STORMS. THE BEST CHANCE OF GETTING WET WILL CONTINUE TO BE DURING THE AFTERNOON AND EVENING HOURS. EXPECT DAYTIME TEMPERATURES TO GENERALLY BE 5 OR MORE DEGREES ABOVE NORMAL DURING THE PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... 18Z WEDNESDAY THROUGH 18Z THURSDAY... HIGH PRESSURE DOMINATES. STUBBORN STRATUS OVER CENTRAL WEST VIRGINIA FINALLY ERODES BY 19Z...SO THAT GENERAL VFR SCT-BKN CU WILL PREVAIL THROUGH 00Z. AFTER 00Z VFR MOSTLY CLEAR EXCEPT FOR LOCALLY DENSE RIVER AND VALLEY FOG 06Z TO 12Z AFFECTING THE MAJOR TERMINALS. AFTER 14Z...VFR SCT-BKN CU. JUST A SMALL CHANCE OF AN AFTERNOON THUNDERSTORM...MAINLY OVER THE MOUNTAIN HIGH TERRAIN. CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM TO HIGH. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY... FORECAST CONFIDENCE: TIMING OF DENSITY OF REDUCED VIS AND/OR LOW STRATUS AFTER 06Z THU MAY VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H M M H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z THURSDAY... IFR OR WORSE FG DEVELOPING WED NT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/50 NEAR TERM...JMV SHORT TERM...ARJ LONG TERM...JSH AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1146 AM EDT WED JUN 19 2013 .SYNOPSIS... HIGH PRESSURE CRUISES WEDNESDAY AND THURSDAY...BEFORE DROPPING ANCHOR IN THE WESTERN ATLANTIC TO BEGIN THE SUMMER SEASON. HIGH RIDGE ALOFT KEEPS DRY CONDITIONS THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 1145 AM UPDATE...STRATUS ERODING RAPIDLY SO THAT MOST OF THIS AFTERNOON WILL SEE LOTS OF SUNSHINE AND WARM TEMPERATURES. STILL WILL LEAVE A SLIGHT CHANCE IN THE MOUNTAINS BEFORE DRY AIR MIXES DOWN LATER AROUND MID AFTERNOON. WILL INCLUDE LOCALLY DENSE FOG TONIGHT. 630 AM UPDATE... SFC FRONT ROUGHLY FROM POCAHONTAS COUNTY SW-WARD TO JUST NORTH OF BKW AT THIS TIME AND WILL CONTINUE A BIT FURTHER SOUTHWARD INTO VIRGINIA BEFORE STALLING LATER THIS MORNING. TWEAKED SKY COVER TO REFLECT QUICKER CLEARING ACROSS SE OHIO AND INTO ADJACENT WEST VIRGINIA. INGESTED RECENT OBS. OTHERWISE...NO MAJOR CHANGES. PREVIOUS DISCUSSION... AT 06Z SFC OBS INDICATE SECONDARY FRONT LOCATED ROUGHLY FROM HTS EAST/NORTHEAST TO NEAR CKB. NEAR AND AHEAD OF IT A FEW SHOWERS AND EVEN ONE THUNDERSTORM HAD REDEVELOPED EARLY THIS MORNING. THE ENHANCEMENT LIKELY DUE TO A VORT MAX...EVIDENT IN WV IMAGERY...MOVING QUICKLY ACROSS NORTH CENTRAL OHIO. ALL IN ALL EXPECT A NICE DAY FOR MOST FOLKS AS THE AFOREMENTIONED FRONT MOVES THROUGH THE AREA...UNDER PARTLY TO MOSTLY SUNNY SKIES BY THE AFTERNOON AND SEASONABLY WARM TEMPS. LARGE SCALE FORCING FOR SUBSIDENCE WILL OVERSPREAD THE FORECAST AREA FROM NW TO SE AS A 500MB S/W TROUGH PUSHES EASTWARD ACROSS AND EXITS TO THE EAST AROUND THE 18Z-21Z TIME FRAME. BY THE AFTERNOON HOURS HOWEVER...THE SFC FRONT BEGINS TO WASH OUT AND AS SFC HIGH PRESSURE REBUILDS TO THE EAST. MODELS IN GOOD AGREEMENT WITH GOOD SFC CONVERGENCE ALONG THE EASTERN HIGH TERRAIN PEAKS AS SFC FLOW ON THE EAST SIDE RETURNS QUICKLY TO THE EAST/SOUTHEAST...WHILE FLOW ON THE WINDWARD SIDE REMAINS NORTH/NORTHWEST. SOME QUESTION AND DOUBT AS TO THE DEPTH OF MOISTURE BEING DEPICTED ON LATEST NAM12 SOUNDINGS HOWEVER...AND LATEST RUC13 SOUNDINGS ARE INDEED MUCH DRYER IN LOWER LEVELS. EVEN WITH THE MORE SATURATED NAM12...PWATS STILL ONLY PROGGED AROUND 0.8IN-0.9IN WITH VERY DRY AIR ALOFT WHICH WOULD SERVE TO LIMIT COVERAGE. PREV FCST HAD A GOOD HANDLE ON THIS AND WILL CONTINUE SLIGHT CHANCE TO LOW CHANCE POPS ESSENTIALLY FROM THE HIGHEST PEAKS AND POINTS SOUTH AND EAST...WITH STORM MOTION TO THE SOUTHEAST. DID INSERT A SLIGHT THUNDER MENTION WITH DECENT INSTABILITY IN THAT AREA. AS SUCH...KEPT CLOUD COVER HIGHER IN THE EASTERN HIGH COUNTRY AS WELL. ALSO NUDGED MAX TEMPS UP AN ADDITIONAL DEGREE OR TWO FOR MOST LOCATIONS PER LATEST PROGGED 925MB AND 850MB TEMPS WITH MOS GUIDANCE SUPPORTING...ALTHOUGH DID KEEP MAX TEMPS IN THE MOUNTAINS JUST A BIT LOWER WITH MORE CLOUDS AND SOME AFTERNOON PRECIP POTENTIAL. OVERNIGHT FORECAST REMAINS VIRTUALLY UNCHANGED FROM PREV SHIFT THINKING...WITH MINS IN THE MID AND UPPER 50S LOWLANDS. WILL HAVE PRECIP ENDING AT 00Z THU IN THE MOUNTAINS. AREAS OF FOG ARE A GOOD BET ONCE AGAIN IN THE LOWLANDS UNDER A MOSTLY CLEAR SKY AND NEAR-CALM WINDS...ALTHOUGH SOME LOWER DEWPOINTS ACROSS SE OHIO AND MORE CLOUD COVER IN THE MOUNTAINS MAY LIMIT COVERAGE IN THOSE AREAS. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... SFC HIGH PRESSURE MOVE OFF SHORE THE NORTHEAST COAST LATE THURSDAY LOSING ITS INFLUENCE WEST OF THE APPALACHIANS. HOWEVER...ABUNDANT LOW LEVEL MOISTURE AND ELEVATED HEAT SOURCES COULD PRODUCE ISOLATED AFTERNOON SHOWERS OR STORMS OVER HIGHER ELEVATIONS THROUGH THE WEEKEND. A MID LEVEL RIDGE MOVES OVERHEAD SATURDAY PROVIDING SOME SUBSIDENCE AND CLEAR SKIES. AFTERNOON CU WILL BE COMMON JUST TO DISSIPATE AFTER SUNSET. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... SURFACE HIGH PRESSURE WILL REMAIN CENTERED ACROSS THE SOUTHEAST STATES...WITH A RIDGE EXTENDING NORTH INTO WEST VIRGINIA. SOUTHERLY WINDS WILL RESULT IN DEW POINTS INCREASING TO THE UPPER 60S AND LOWER 70S. AS A RESULT...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORM WILL BE A POSSIBILITY...MAINLY DURING THE AFTERNOON AND EVENING HOURS. AN UPPER LEVEL TROF AND AN ASSOCIATED COLD FRONT WILL APPROACH FROM THE WEST LATE IN THE PERIOD...RESULTING IN BETTER CHANCES FOR SHOWERS AND STORMS. THE BEST CHANCE OF GETTING WET WILL CONTINUE TO BE DURING THE AFTERNOON AND EVENING HOURS. EXPECT DAYTIME TEMPERATURES TO GENERALLY BE 5 OR MORE DEGREES ABOVE NORMAL DURING THE PERIOD. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... 16Z WEDNESDAY THROUGH 12Z THURSDAY... STRATUS ERODING QUICKLY SO THAT GENERAL VFR SCT-BKN CU WILL PREVAIL AFTER 18Z. JUST A FEW SHOWERS AND PERHAPS A THUNDERSTORM ARE POSSIBLE OVER THE EASTERN HIGH TERRAIN. WILL ADD LOCALLY DENSE RIVER AND VALLEY FOG AFTER 06Z TONIGHT...AFFECTING MOST MAJOR TERMINALS. CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY... FORECAST CONFIDENCE: TIMING OF DENSITY OF REDUCED VIS AND/OR LOW STRATUS AFTER 06Z THU MAY VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H M H H H H H H H H H H HTS CONSISTENCY M H H H H H H H H H H H BKW CONSISTENCY M M M H H H H H H H H H EKN CONSISTENCY H M M H H H H H H H H H PKB CONSISTENCY M H H H H H H H H H H H CKB CONSISTENCY H M H H H H H H H H H H AFTER 18Z THURSDAY... IFR OR WORSE FG DEVELOPING WED NT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/50 NEAR TERM...JMV SHORT TERM...ARJ LONG TERM...JSH AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1037 AM EDT WED JUN 19 2013 .SYNOPSIS... HIGH PRESSURE CRUISES WEDNESDAY AND THURSDAY...BEFORE DROPPING ANCHOR IN THE WESTERN ATLANTIC TO BEGIN THE SUMMER SEASON. HIGH RIDGE ALOFT KEEPS DRY CONDITIONS THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 630 AM UPDATE... SFC FRONT ROUGHLY FROM POCAHONTAS COUNTY SW-WARD TO JUST NORTH OF BKW AT THIS TIME AND WILL CONTINUE A BIT FURTHER SOUTHWARD INTO VIRGINIA BEFORE STALLING LATER THIS MORNING. TWEAKED SKY COVER TO REFLECT QUICKER CLEARING ACROSS SE OHIO AND INTO ADJACENT WEST VIRGINIA. INGESTED RECENT OBS. OTHERWISE...NO MAJOR CHANGES. PREVIOUS DISCUSSION... AT 06Z SFC OBS INDICATE SECONDARY FRONT LOCATED ROUGHLY FROM HTS EAST/NORTHEAST TO NEAR CKB. NEAR AND AHEAD OF IT A FEW SHOWERS AND EVEN ONE THUNDERSTORM HAD REDEVELOPED EARLY THIS MORNING. THE ENHANCEMENT LIKELY DUE TO A VORT MAX...EVIDENT IN WV IMAGERY...MOVING QUICKLY ACROSS NORTH CENTRAL OHIO. ALL IN ALL EXPECT A NICE DAY FOR MOST FOLKS AS THE AFOREMENTIONED FRONT MOVES THROUGH THE AREA...UNDER PARTLY TO MOSTLY SUNNY SKIES BY THE AFTERNOON AND SEASONABLY WARM TEMPS. LARGE SCALE FORCING FOR SUBSIDENCE WILL OVERSPREAD THE FORECAST AREA FROM NW TO SE AS A 500MB S/W TROUGH PUSHES EASTWARD ACROSS AND EXITS TO THE EAST AROUND THE 18Z-21Z TIME FRAME. BY THE AFTERNOON HOURS HOWEVER...THE SFC FRONT BEGINS TO WASH OUT AND AS SFC HIGH PRESSURE REBUILDS TO THE EAST. MODELS IN GOOD AGREEMENT WITH GOOD SFC CONVERGENCE ALONG THE EASTERN HIGH TERRAIN PEAKS AS SFC FLOW ON THE EAST SIDE RETURNS QUICKLY TO THE EAST/SOUTHEAST...WHILE FLOW ON THE WINDWARD SIDE REMAINS NORTH/NORTHWEST. SOME QUESTION AND DOUBT AS TO THE DEPTH OF MOISTURE BEING DEPICTED ON LATEST NAM12 SOUNDINGS HOWEVER...AND LATEST RUC13 SOUNDINGS ARE INDEED MUCH DRYER IN LOWER LEVELS. EVEN WITH THE MORE SATURATED NAM12...PWATS STILL ONLY PROGGED AROUND 0.8IN-0.9IN WITH VERY DRY AIR ALOFT WHICH WOULD SERVE TO LIMIT COVERAGE. PREV FCST HAD A GOOD HANDLE ON THIS AND WILL CONTINUE SLIGHT CHANCE TO LOW CHANCE POPS ESSENTIALLY FROM THE HIGHEST PEAKS AND POINTS SOUTH AND EAST...WITH STORM MOTION TO THE SOUTHEAST. DID INSERT A SLIGHT THUNDER MENTION WITH DECENT INSTABILITY IN THAT AREA. AS SUCH...KEPT CLOUD COVER HIGHER IN THE EASTERN HIGH COUNTRY AS WELL. ALSO NUDGED MAX TEMPS UP AN ADDITIONAL DEGREE OR TWO FOR MOST LOCATIONS PER LATEST PROGGED 925MB AND 850MB TEMPS WITH MOS GUIDANCE SUPPORTING...ALTHOUGH DID KEEP MAX TEMPS IN THE MOUNTAINS JUST A BIT LOWER WITH MORE CLOUDS AND SOME AFTERNOON PRECIP POTENTIAL. OVERNIGHT FORECAST REMAINS VIRTUALLY UNCHANGED FROM PREV SHIFT THINKING...WITH MINS IN THE MID AND UPPER 50S LOWLANDS. WILL HAVE PRECIP ENDING AT 00Z THU IN THE MOUNTAINS. AREAS OF FOG ARE A GOOD BET ONCE AGAIN IN THE LOWLANDS UNDER A MOSTLY CLEAR SKY AND NEAR-CALM WINDS...ALTHOUGH SOME LOWER DEWPOINTS ACROSS SE OHIO AND MORE CLOUD COVER IN THE MOUNTAINS MAY LIMIT COVERAGE IN THOSE AREAS. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... SFC HIGH PRESSURE MOVE OFF SHORE THE NORTHEAST COAST LATE THURSDAY LOSING ITS INFLUENCE WEST OF THE APPALACHIANS. HOWEVER...ABUNDANT LOW LEVEL MOISTURE AND ELEVATED HEAT SOURCES COULD PRODUCE ISOLATED AFTERNOON SHOWERS OR STORMS OVER HIGHER ELEVATIONS THROUGH THE WEEKEND. A MID LEVEL RIDGE MOVES OVERHEAD SATURDAY PROVIDING SOME SUBSIDENCE AND CLEAR SKIES. AFTERNOON CU WILL BE COMMON JUST TO DISSIPATE AFTER SUNSET. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... SURFACE HIGH PRESSURE WILL REMAIN CENTERED ACROSS THE SOUTHEAST STATES...WITH A RIDGE EXTENDING NORTH INTO WEST VIRGINIA. SOUTHERLY WINDS WILL RESULT IN DEW POINTS INCREASING TO THE UPPER 60S AND LOWER 70S. AS A RESULT...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORM WILL BE A POSSIBILITY...MAINLY DURING THE AFTERNOON AND EVENING HOURS. AN UPPER LEVEL TROF AND AN ASSOCIATED COLD FRONT WILL APPROACH FROM THE WEST LATE IN THE PERIOD...RESULTING IN BETTER CHANCES FOR SHOWERS AND STORMS. THE BEST CHANCE OF GETTING WET WILL CONTINUE TO BE DURING THE AFTERNOON AND EVENING HOURS. EXPECT DAYTIME TEMPERATURES TO GENERALLY BE 5 OR MORE DEGREES ABOVE NORMAL DURING THE PERIOD. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... 12Z WEDNESDAY THROUGH 12Z THURSDAY... ONCE EARLY MORNING FOG AND LOW STRATUS SCATTER/LIFT...VFR CONDITIONS WILL PREVAIL THROUGH THE REMAINDER OF THE DAY AND MUCH OF THE EVENING. HIGH PRESSURE OVERHEAD WILL RESULT IN LIGHT NORTH/NORTHEAST WINDS TODAY. A FEW SHOWERS AND PERHAPS A THUNDERSTORM ARE POSSIBLE OVER THE EASTERN HIGH TERRAIN...WHICH COULD IMPACT EKN. NEAR-CALM WINDS AND MOSTLY CLEAR SKIES WILL RESULT IN FOG AND REDUCED VSBYS ONCE AGAIN BY AND AFTER 03Z MAINLY FOR LOWLAND WEST VIRGINIA LOCATIONS. DRIER AIR ACROSS SE OHIO AND MORE OVERNIGHT CLOUD COVER MAY HELP TO MITIGATE FOG IN THESE AREAS. CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: TIMING OF FLIGHT CONDITIONS IMPROVEMENT THIS MORNING MAY VARY. ONSET...COVERAGE...AND DENSITY OF REDUCED VIS AND/OR LOW STRATUS AFTER 06Z THU MAY VARY AS WELL. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H M H H H H H H H H H H HTS CONSISTENCY M H H H H H H H H H H H BKW CONSISTENCY M M M H H H H H H H H H EKN CONSISTENCY H M M H H H H H H H H H PKB CONSISTENCY M H H H H H H H H H H H CKB CONSISTENCY H M H H H H H H H H H H AFTER 12Z THURSDAY... IFR OR WORSE FG DEVELOPING WED NT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/50 NEAR TERM...50 SHORT TERM...ARJ LONG TERM...JSH AVIATION...50
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
649 AM EDT WED JUN 19 2013 .SYNOPSIS... HIGH PRESSURE CRUISES WEDNESDAY AND THURSDAY...BEFORE DROPPING ANCHOR IN THE WESTERN ATLANTIC TO BEGIN THE SUMMER SEASON. HIGH RIDGE ALOFT KEEPS DRY CONDITIONS THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 630 AM UPDATE... SFC FRONT ROUGHLY FROM POCAHONTAS COUNTY SW-WARD TO JUST NORTH OF BKW AT THIS TIME AND WILL CONTINUE A BIT FURTHER SOUTHWARD INTO VIRGINIA BEFORE STALLING LATER THIS MORNING. TWEAKED SKY COVER TO REFLECT QUICKER CLEARING ACROSS SE OHIO AND INTO ADJACENT WEST VIRGINIA. INGESTED RECENT OBS. OTHERWISE...NO MAJOR CHANGES. PREVIOUS DISCUSSION... AT 06Z SFC OBS INDICATE SECONDARY FRONT LOCATED ROUGHLY FROM HTS EAST/NORTHEAST TO NEAR CKB. NEAR AND AHEAD OF IT A FEW SHOWERS AND EVEN ONE THUNDERSTORM HAD REDEVELOPED EARLY THIS MORNING. THE ENHANCEMENT LIKELY DUE TO A VORT MAX...EVIDENT IN WV IMAGERY...MOVING QUICKLY ACROSS NORTH CENTRAL OHIO. ALL IN ALL EXPECT A NICE DAY FOR MOST FOLKS AS THE AFOREMENTIONED FRONT MOVES THROUGH THE AREA...UNDER PARTLY TO MOSTLY SUNNY SKIES BY THE AFTERNOON AND SEASONABLY WARM TEMPS. LARGE SCALE FORCING FOR SUBSIDENCE WILL OVERSPREAD THE FORECAST AREA FROM NW TO SE AS A 500MB S/W TROUGH PUSHES EASTWARD ACROSS AND EXITS TO THE EAST AROUND THE 18Z-21Z TIME FRAME. BY THE AFTERNOON HOURS HOWEVER...THE SFC FRONT BEGINS TO WASH OUT AND AS SFC HIGH PRESSURE REBUILDS TO THE EAST. MODELS IN GOOD AGREEMENT WITH GOOD SFC CONVERGENCE ALONG THE EASTERN HIGH TERRAIN PEAKS AS SFC FLOW ON THE EAST SIDE RETURNS QUICKLY TO THE EAST/SOUTHEAST...WHILE FLOW ON THE WINDWARD SIDE REMAINS NORTH/NORTHWEST. SOME QUESTION AND DOUBT AS TO THE DEPTH OF MOISTURE BEING DEPICTED ON LATEST NAM12 SOUNDINGS HOWEVER...AND LATEST RUC13 SOUNDINGS ARE INDEED MUCH DRYER IN LOWER LEVELS. EVEN WITH THE MORE SATURATED NAM12...PWATS STILL ONLY PROGGED AROUND 0.8IN-0.9IN WITH VERY DRY AIR ALOFT WHICH WOULD SERVE TO LIMIT COVERAGE. PREV FCST HAD A GOOD HANDLE ON THIS AND WILL CONTINUE SLIGHT CHANCE TO LOW CHANCE POPS ESSENTIALLY FROM THE HIGHEST PEAKS AND POINTS SOUTH AND EAST...WITH STORM MOTION TO THE SOUTHEAST. DID INSERT A SLIGHT THUNDER MENTION WITH DECENT INSTABILITY IN THAT AREA. AS SUCH...KEPT CLOUD COVER HIGHER IN THE EASTERN HIGH COUNTRY AS WELL. ALSO NUDGED MAX TEMPS UP AN ADDITIONAL DEGREE OR TWO FOR MOST LOCATIONS PER LATEST PROGGED 925MB AND 850MB TEMPS WITH MOS GUIDANCE SUPPORTING...ALTHOUGH DID KEEP MAX TEMPS IN THE MOUNTAINS JUST A BIT LOWER WITH MORE CLOUDS AND SOME AFTERNOON PRECIP POTENTIAL. OVERNIGHT FORECAST REMAINS VIRTUALLY UNCHANGED FROM PREV SHIFT THINKING...WITH MINS IN THE MID AND UPPER 50S LOWLANDS. WILL HAVE PRECIP ENDING AT 00Z THU IN THE MOUNTAINS. AREAS OF FOG ARE A GOOD BET ONCE AGAIN IN THE LOWLANDS UNDER A MOSTLY CLEAR SKY AND NEAR-CALM WINDS...ALTHOUGH SOME LOWER DEWPOINTS ACROSS SE OHIO AND MORE CLOUD COVER IN THE MOUNTAINS MAY LIMIT COVERAGE IN THOSE AREAS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... SFC HIGH PRESSURE MOVE OFF SHORE THE NORTHEAST COAST LATE THURSDAY LOSING ITS INFLUENCE WEST OF THE APPALACHIANS. HOWEVER...ABUNDANT LOW LEVEL MOISTURE AND ELEVATED HEAT SOURCES COULD PRODUCE ISOLATED AFTERNOON SHOWERS OR STORMS OVER HIGHER ELEVATIONS THROUGH THE WEEKEND. A MID LEVEL RIDGE MOVES OVERHEAD SATURDAY PROVIDING SOME SUBSIDENCE AND CLEAR SKIES. AFTERNOON CU WILL BE COMMON JUST TO DISSIPATE AFTER SUNSET. && .LONG TERM /SATURDAY THROUGH TUESDAY/... RIDGING WILL CONTINUE TO STRENGTHEN THROUGH THE WEEKEND INCREASING HIGH TEMPERATURES INTO AT LEAST THE THE UPPER 80S. WITH A CONTINUED MOISTURE TAP DEW POINTS WILL ALSO INCREASE INTO THE UPPER 60S TO AROUND 70. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORM WILL BE A POSSIBILITY MOST EVERY AFTERNOON AND EVENING. ABOVE NORMAL TEMPERATURES AND MUGGY CONDITIONS LOOK LIKELY TO CONTINUE INTO THE FIRST HALF OF NEXT WEEK AS THE BROAD UPPER LEVEL RIDGING OVER THE EASTERN HALF OF THE US CONTINUES. WILL BE LOOKING FOR A DRIER PATTERN TO SETTLE IN THRU LATE WEEK AND AT LEAST FIRST HALF OF WEEKEND. EXCEPTION IS THE MTNS WHERE A FEW SHRA/TSRA POSSIBLE EACH AFTN AS A LEE SIDE TROF SETS UP IN CONJUNCTION WITH LLVL SE FLOW AND DIFF HEATING. A S/W TROF WILL TRY TO BEAT DOWN UPR RIDGE JUST AS IT TRIES TO BUILD E INTO AREA LATE SUNDAY INTO MONDAY. HAVE CARRIED SOME CHC POPS WITH THIS AT THIS DISTANCE. TEMPS WARM UP TO 2 TO 4 DEGREES ABV NORMAL...ESPECIALLY AT NIGHT AT THE MUGGIES BEGIN TO TAKE OVER. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... 12Z WEDNESDAY THROUGH 12Z THURSDAY... ONCE EARLY MORNING FOG AND LOW STRATUS SCATTER/LIFT...VFR CONDITIONS WILL PREVAIL THROUGH THE REMAINDER OF THE DAY AND MUCH OF THE EVENING. HIGH PRESSURE OVERHEAD WILL RESULT IN LIGHT NORTH/NORTHEAST WINDS TODAY. A FEW SHOWERS AND PERHAPS A THUNDERSTORM ARE POSSIBLE OVER THE EASTERN HIGH TERRAIN...WHICH COULD IMPACT EKN. NEAR-CALM WINDS AND MOSTLY CLEAR SKIES WILL RESULT IN FOG AND REDUCED VSBYS ONCE AGAIN BY AND AFTER 03Z MAINLY FOR LOWLAND WEST VIRGINIA LOCATIONS. DRIER AIR ACROSS SE OHIO AND MORE OVERNIGHT CLOUD COVER MAY HELP TO MITIGATE FOG IN THESE AREAS. CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: TIMING OF FLIGHT CONDITIONS IMPROVEMENT THIS MORNING MAY VARY. ONSET...COVERAGE...AND DENSITY OF REDUCED VIS AND/OR LOW STRATUS AFTER 06Z THU MAY VARY AS WELL. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 CRW CONSISTENCY L L L M M H H H H H H H HTS CONSISTENCY L L L M H H H H H H H H BKW CONSISTENCY L L L M M M H H H H H H EKN CONSISTENCY L L L H M M H H H H H H PKB CONSISTENCY L L L M H H H H H H H H CKB CONSISTENCY L L M M M H H H H H H H AFTER 12Z THURSDAY... IFR OR WORSE FG DEVELOPING WED NT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/50 NEAR TERM...50 SHORT TERM...ARJ LONG TERM...JR AVIATION...50
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
400 AM EDT WED JUN 19 2013 .SYNOPSIS... HIGH PRESSURE CRUISES WEDNESDAY AND THURSDAY...BEFORE DROPPING ANCHOR IN THE WESTERN ATLANTIC TO BEGIN THE SUMMER SEASON. HIGH RIDGE ALOFT KEEPS DRY CONDITIONS THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AT 06Z SFC OBS INDICATE SECONDARY FRONT LOCATED ROUGHLY FROM HTS EAST/NORTHEAST TO NEAR CKB. NEAR AND AHEAD OF IT A FEW SHOWERS AND EVEN ONE THUNDERSTORM HAD REDEVELOPED EARLY THIS MORNING. THE ENHANCEMENT LIKELY DUE TO A VORT MAX...EVIDENT IN WV IMAGERY...MOVING QUICKLY ACROSS NORTH CENTRAL OHIO. ALL IN ALL EXPECT A NICE DAY FOR MOST FOLKS AS THE AFOREMENTIONED FRONT MOVES THROUGH THE AREA...UNDER PARTLY TO MOSTLY SUNNY SKIES BY THE AFTERNOON AND SEASONABLY WARM TEMPS. LARGE SCALE FORCING FOR SUBSIDENCE WILL OVERSPREAD THE FORECAST AREA FROM NW TO SE AS A 500MB S/W TROUGH PUSHES EASTWARD ACROSS AND EXITS TO THE EAST AROUND THE 18Z-21Z TIME FRAME. BY THE AFTERNOON HOURS HOWEVER...THE SFC FRONT BEGINS TO WASH OUT AND AS SFC HIGH PRESSURE REBUILDS TO THE EAST. MODELS IN GOOD AGREEMENT WITH GOOD SFC CONVERGENCE ALONG THE EASTERN HIGH TERRAIN PEAKS AS SFC FLOW ON THE EAST SIDE RETURNS QUICKLY TO THE EAST/SOUTHEAST...WHILE FLOW ON THE WINDWARD SIDE REMAINS NORTH/NORTHWEST. SOME QUESTION AND DOUBT AS TO THE DEPTH OF MOISTURE BEING DEPICTED ON LATEST NAM12 SOUNDINGS HOWEVER...AND LATEST RUC13 SOUNDINGS ARE INDEED MUCH DRYER IN LOWER LEVELS. EVEN WITH THE MORE SATURATED NAM12...PWATS STILL ONLY PROGGED AROUND 0.8IN-0.9IN WITH VERY DRY AIR ALOFT WHICH WOULD SERVE TO LIMIT COVERAGE. PREV FCST HAD A GOOD HANDLE ON THIS AND WILL CONTINUE SLIGHT CHANCE TO LOW CHANCE POPS ESSENTIALLY FROM THE HIGHEST PEAKS AND POINTS SOUTH AND EAST...WITH STORM MOTION TO THE SOUTHEAST. DID INSERT A SLIGHT THUNDER MENTION WITH DECENT INSTABILITY IN THAT AREA. AS SUCH...KEPT CLOUD COVER HIGHER IN THE EASTERN HIGH COUNTRY AS WELL. ALSO NUDGED MAX TEMPS UP AN ADDITIONAL DEGREE OR TWO FOR MOST LOCATIONS PER LATEST PROGGED 925MB AND 850MB TEMPS WITH MOS GUIDANCE SUPPORTING...ALTHOUGH DID KEEP MAX TEMPS IN THE MOUNTAINS JUST A BIT LOWER WITH MORE CLOUDS AND SOME AFTERNOON PRECIP POTENTIAL. OVERNIGHT FORECAST REMAINS VIRTUALLY UNCHANGED FROM PREV SHIFT THINKING...WITH MINS IN THE MID AND UPPER 50S LOWLANDS. WILL HAVE PRECIP ENDING AT 00Z THU IN THE MOUNTAINS. AREAS OF FOG ARE A GOOD BET ONCE AGAIN IN THE LOWLANDS UNDER A MOSTLY CLEAR SKY AND NEAR-CALM WINDS...ALTHOUGH SOME LOWER DEWPOINTS ACROSS SE OHIO AND MORE CLOUD COVER IN THE MOUNTAINS MAY LIMIT COVERAGE IN THOSE AREAS. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... SFC HIGH PRESSURE MOVE OFF SHORE THE NORTHEAST COAST LATE THURSDAY LOSING ITS INFLUENCE WEST OF THE APPALACHIANS. HOWEVER...ABUNDANT LOW LEVEL MOISTURE AND ELEVATED HEAT SOURCES COULD PRODUCE ISOLATED AFTERNOON SHOWERS OR STORMS OVER HIGHER ELEVATIONS THROUGH THE WEEKEND. A MID LEVEL RIDGE MOVES OVERHEAD SATURDAY PROVIDING SOME SUBSIDENCE AND CLEAR SKIES. AFTERNOON CU WILL BE COMMON JUST TO DISSIPATE AFTER SUNSET. && .LONG TERM /SUNDAY THROUGH TUESDAY/... RIDGING WILL CONTINUE TO STRENGTHEN THROUGH THE WEEKEND INCREASING HIGH TEMPERATURES INTO AT LEAST THE THE UPPER 80S. WITH A CONTINUED MOISTURE TAP DEW POINTS WILL ALSO INCREASE INTO THE UPPER 60S TO AROUND 70. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORM WILL BE A POSSIBILITY MOST EVERY AFTERNOON AND EVENING. ABOVE NORMAL TEMPERATURES AND MUGGY CONDITIONS LOOK LIKELY TO CONTINUE INTO THE FIRST HALF OF NEXT WEEK AS THE BROAD UPPER LEVEL RIDGING OVER THE EASTERN HALF OF THE US CONTINUES. WILL BE LOOKING FOR A DRIER PATTERN TO SETTLE IN THRU LATE WEEK AND AT LEAST FIRST HALF OF WEEKEND. EXCEPTION IS THE MTNS WHERE A FEW SHRA/TSRA POSSIBLE EACH AFTN AS A LEE SIDE TROF SETS UP IN CONJUNCTION WITH LLVL SE FLOW AND DIFF HEATING. A S/W TROF WILL TRY TO BEAT DOWN UPR RIDGE JUST AS IT TRIES TO BUILD E INTO AREA LATE SUNDAY INTO MONDAY. HAVE CARRIED SOME CHC POPS WITH THIS AT THIS DISTANCE. TEMPS WARM UP TO 2 TO 4 DEGREES ABV NORMAL...ESPECIALLY AT NIGHT AT THE MUGGIES BEGIN TO TAKE OVER. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... A FEW SHOWERS HAVE REDEVELOPED LATE THIS EVENING AHEAD OF AN ADVANCING COLD FRONT...ROUGHLY FROM CKB TO HTS. AT THIS POINT...ALL SHRA HAS REMAINED JUST OFF TO THE NE OF CRW AND ONLY EXPECTED TO POTENTIALLY AFFECT EKN AND CKB. THESE SHOWERS WILL DELAY THE ONSET OF FOG AND LOW STRATUS...BUT WILL ONLY INCREASE DENSITY SHOULD A SHOWER MAKE A DIRECT IMPACT ON A TERMINAL ONCE THE SHOWER AND CLOUDS SCATTER. BY NEAR DAWN...EXPECT ALL SITES TO BE AT LEAST IFR IN REDUCED VIS...IF NOT LOWER. ALL OF THIS LOW LEVEL MOISTURE WILL BE SLOW TO BURN OFF WED MORNING DESPITE FRONTAL PASSAGE AS IT MIXES INTO MORNING CU. BY MID-MORNING VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR THE REMAINDER OF THE DAY AND EARLY EVENING AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH...ALTHOUGH A LATE DAY SHOWER OR THUNDERSTORMS MAY POP UP OVER THE HIGHER TERRAIN. MVFR VIS MAY REDEVELOP NEAR END OF PERIOD. NEAR CALM WINDS OVERNIGHT...AND BECOME LIGHT N TO NE ON WED. FLOW ALOFT WILL BE MAINLY LIGHT N. CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY... FORECAST CONFIDENCE: STRATUS MAY MATERIALIZE MORE THAN FCST WHICH WOULD ALLOW FOR LESS LIFR FG TO DEVELOP ACROSS THE AREA OVERNIGHT. THE TIMING OF IMPROVEMENT WED MORNING COULD ALSO VARY FROM FCST. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE WED 06/19/13 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15 CRW CONSISTENCY L L L L L L M M H H H H HTS CONSISTENCY L L L L L L M H H H H H BKW CONSISTENCY L L L L L L M M M H H H EKN CONSISTENCY L L L L L L M M M H H H PKB CONSISTENCY L L L L L L M H H H H H CKB CONSISTENCY L L L L L M M M H H H H AFTER 06Z THURSDAY... IFR OR WORSE FG DEVELOPING WED NT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/50 NEAR TERM...50 SHORT TERM...ARJ LONG TERM...JR AVIATION...50
AREA FORECAST DISCUSSION
NWS NORMAN OK
104 PM CDT WED JUN 19 2013 .DISCUSSION... 18Z AVIATION DISCUSSION FOLLOWS.... && .AVIATION... A THUNDERSTORM COMPLEX SW OF KHBR-KLAW-KSPS WILL CONTINUE TO MOVE SSE THIS AFTERNOON. NO TSRA ARE LIKELY AT OUR TAF SITES...BUT STRONG TO SEVERE TSRA MAY OCCUR FARTHER SW EARLY THIS AFTERNOON. A WAKE LOW HAS GENERATED A VERY TIGHT PRESSURE GRADIENT ACROSS SW OK...SO SMALL AREAS OF RATHER STRONG WINDS WILL SHIFT SLOWLY SSE...ALONGSIDE THE COMPLEX. SCT TSRA MAY FORM LATER TODAY/TONIGHT OVER W OR N OK...BASED ON MODEL FORECASTS...HOWEVER THE TSRA COMPLEX MAY HAVE ALTERED THE ATMOSPHERE SUFFICIENTLY TO PREVENT THIS DEVELOPMENT. SOME GULF STRATUS IS POSSIBLE OVER THE E 1/2 OF OK TOMORROW MORNING...BUT CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME TO INCLUDE MVFR CONDITIONS. && .PREV DISCUSSION... /ISSUED 1140 AM CDT WED JUN 19 2013/ UPDATE... MADE A FEW MINOR TWEAKS TO THE GOING FORECAST. SOUTHERN END OF ONGOING STORM COMPLEX HAS MOVED INTO FAR WESTERN NORTH TEXAS. HAVE UPPED POPS TO LIKELY OVER THIS AREA AND MAINTAIN CHANCE POPS THROUGH LATE AFTERNOON. THEREAFTER...ONLY ISOLATED ACTIVITY IS EXPECTED BEFORE ADDITIONAL STORMS DEVELOP THIS EVENING AND OVERNIGHT. GIVEN SUBSTANTIAL CLOUD COVER HAS LIMITED HEATING ACROSS SOUTHWEST OKLAHOMA AND NORTH TEXAS...HAVE TWEAKED HOURLY TEMPERATURES TO REFLECT THIS. STILL EXPECT ONCE CLOUDS CLEAR...QUICK WARMING WILL ENSUE AND WILL MAINTAIN GOING HIGH TEMPERATURES THIS AFTERNOON. OTHERWISE...ONLY MINOR UPDATES WERE MADE TO HOURLY WINDS AND DEWPOINTS. THE MAIN CONCERN WILL BE FOR LOCALIZED HEAVY RAINFALL WHICH MAY LEAD TO FLASH FLOODING OVER PARTS OF WESTERN NORTH TEXAS. OTHERWISE...THE DAY SHOULD BE RELATIVELY QUIET AND MILD. DISCUSSION... PREV DISCUSSION... /ISSUED 652 AM CDT WED JUN 19 2013/ DISCUSSION... 12Z AVIATION DISCUSSION FOLLOWS BELOW... AVIATION... THUNDERSTORMS CONTINUE TO MOVE S/SE ACROSS THE TEXAS PANHANDLE AND FAR NORTHWESTERN OKLAHOMA THIS MORNING. THIS ACTIVITY WILL CONTINUE TO IMPACT KWWR AND KGAG THROUGH MID TO LATE MORNING. THIS ACTIVITY WILL SLOWLY DISSIPATE THROUGH NOON. THUNDERSTORM CHANCES WILL THEN INCREASE THROUGH THE AFTERNOON AND EVENING ACROSS NORTHERN OKLAHOMA. LOW CONFIDENCE ON TIMING AND LOCATION... THEREFORE...HAVE LEFT OUT A MENTION IN THE KWWR...KGAG...AND KPNC TAFS. THERE REMAINS A CHANCE OF MVFR STRATUS ACROSS THE SOUTHERN PORTIONS OF OKLAHOMA AND WESTERN NORTH TEXAS THIS AFTERNOON...BUT CONFIDENCE REMAINS LOW...SO KEPT CEILINGS AT VFR AT THE MOMENT. WINDS WILL REMAIN OUT OF THE SOUTH...PICKING UP THROUGH NOON...WITH AFTERNOON GUSTS 20 TO 25 KTS AT TIMES. JTK PREV DISCUSSION... /ISSUED 347 AM CDT WED JUN 19 2013/ DISCUSSION... CURRENTLY...A WEAK MCS CONTINUES TO MOVE EASTWARD ACROSS SRN KS AND NWRN OK. THIS AREA OF CONVECTION REMAINS FOCUSED ALONG A LOW- LEVEL MOISTURE/THETA E AXIS POSITIONED ALONG/NEAR THE WRN KS/OK BORDER. OVERALL...MESOSCALE GUIDANCE HAS HAD A DIFFICULT GO THIS MORNING IN THE TRACK AND INTENSITY OF THESE STORMS. CURRENT THOUGHTS LEAN TOWARD THE MCS WEAKENING OVER THE NEXT FEW HOURS AS IT CONTINUES TO TRACK EASTWARD. CONDITIONS ARE LESS FAVORABLE FOR MCS MAINTENANCE ACROSS NRN AND CENTRAL OK...WHERE THE MOISTURE PROFILE IS LESS FAVORABLE AND MID-LEVEL LAPSE RATES WEAKEN CONSIDERABLY. THERE IS DECENT DEEP LAYER SHEAR...30-40KTS SPREAD INTO CENTRAL OK...BUT MUCAPES REMAIN LOW FOR MCS SUPPORT...700 TO 1000 J/KG. OVERALL...THE NEXT 12 TO 24 HOURS WILL POSE A FAIRLY DECENT CHALLENGE FORECASTWISE. THE RECENT 06Z RUN OF THE HRRR REVISES ITS PREVIOUS FORECAST...WITH CONVECTION DEVELOPING BEHIND THE MAIN LINE AND SURGING SOUTHWARD THROUGH THE TX PANHANDLE THROUGH THE MORNING. CURRENT RADAR TRENDS SUGGEST THIS MIGHT BE A POSSIBLE SCENARIO...AS NEW CONVECTION HAS STARTED TO DEVELOP OVER THE PAST HOUR...SINCE 230 AM...ACROSS SERN CO AND THE OK PANHANDLE. FOR THE MOMENT...WILL CONTINUE WITH CHANCE POPS ACROSS NWRN OK THROUGH THE MORNING HOURS. FOR THIS AFTERNOON...THE SHALLOW 500MB RIDGE WILL CONTINUE TO SHIFT/TILT EASTWARD ACROSS THE SRN PLAINS...WHILE ANOTHER LOW AMPLITUDE SHORTWAVE TRAVERSES THE REGION. WITH UPPER LEVEL SUPPORT...AND THE PAC NW TROUGH DIGGING EASTWARD...A STOUT SFC TROUGH/FRONT WILL EXTEND THE LENGTH OF THE FRONT RANGE INTO THE CENTRAL HIGH PLAINS. THIS COULD RESULT IN SOME WEAK SCATTERED CONVECTION LATER THIS AFTERNOON AND OVERNIGHT ACROSS NRN OK...PRIMARILY WELL NORTH OF THE I-40 AND I-44 CORRIDORS. EXPECT COVERAGE TO BE LIMITED WITH THIS SYSTEM...WITH MOST LOCATIONS LIKELY REMAINING DRY AFTER THIS MORNING. FOR THE REMAINDER OF THE WEEK...UPPER LEVEL RIDGING WILL TAKE HOLD...WITH SOUTH/SOUTHWEST FLOW SETTING UP SLOWLY THROUGH THE WEEKEND. TEMPERATURES WILL WARM BACK UP...WITH AFTERNOON HIGHS WELL INTO THE 90S...APPROACHING THE 100S ACROSS SWRN OK AND WRN N TX. THERE COULD BE A FEW ISOLATED SHOWERS ACROSS FAR NWRN OK SUNDAY AS THE WRN TROUGH INTENSIFIES AND A SFC FRONT APPROACHES THE REGION...BUT AT THE MOMENT...EXPECT THE GOOD MAJORITY OF THE AREA TO REMAIN DRY THROUGH THE WEEKEND. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 85 69 89 71 / 10 10 10 0 HOBART OK 90 70 96 72 / 30 10 10 10 WICHITA FALLS TX 90 72 95 73 / 30 10 0 0 GAGE OK 87 69 96 73 / 20 20 10 10 PONCA CITY OK 85 69 88 72 / 10 30 30 10 DURANT OK 88 71 91 72 / 10 10 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 84/23/23
AREA FORECAST DISCUSSION
NWS TULSA OK
1216 PM CDT WED JUN 19 2013 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. SMALL CHANCE OF THUNDERSTORMS OVER MAINLY NE OK AFTER 10Z...HIGHEST ODDS AT KBVO WHERE PROB30 THUNDER WILL BE CARRIED. && .PREV DISCUSSION... /ISSUED 1034 AM CDT WED JUN 19 2013/ DISCUSSION... THUNDERSTORM COMPLEX CONTINUES TO DIVE SOUTH ACROSS TX PANHANDLE THIS MORNING WITH SOME ASSOCIATED ANVIL CIRRUS SPREADING INTO FAR WESTERN REACHES OF THE FORECAST AREA. IN ADDITION A RELATIVE MOIST AXIS FROM ARKLATEX INTO NC OK ASSOCIATED WITH LOWER CLOUDS AND WHILE AN ISOLATED STORM OR TWO MAY DEVELOP IN THIS AREA...FEEL THAT WITH RISING MID LEVEL HEIGHTS THE OVERALL COVERAGE/PROB TOO LOW TO INCLUDE IN FORECAST. THIS MAY BECOME FOCUS FOR OVERNIGHT STORM COMPLEX DEVELOPING OVER CENTRAL PLAINS WHICH WILL HAVE A HIGHER THREAT OF MOVING INTO EASTERN OK BY EARLY THU MORNING HOWEVER. OVERALL FORECAST APPEARS ON TRACK AND WILL MAKE UPDATES FOR LESS CLOUD COVER ACROSS EASTERN AREAS AND TO INCORPORATE HOURLY TRENDS. PREV DISCUSSION... /ISSUED 617 AM CDT WED JUN 19 2013/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. THUNDERSTORM CHANCES APPEAR TOO LOW TO MENTION AT NE OK TAF SITES AT THIS TIME. PREV DISCUSSION... /ISSUED 303 AM CDT WED JUN 19 2013/ DISCUSSION... A RIDGE OF HIGH PRESSURE ALOFT WILL BEGIN TO NUDGE INTO THE AREA FROM THE SOUTHWEST TODAY. BEFORE WE GET INTO SOMETHING OF A DRY PERIOD...THE AREA WILL HAVE TO CONTEND WITH A COUPLE OF THUNDERSTORM COMPLEXES. THIS MORNING THERE IS THUNDERSTORM COMPLEX THAT EXTENDS FROM SOUTHWEST KANSAS INTO THE TEXAS PANHANDLE. THE LATEST HRRR SHOWS THIS COMPLEX MOVING INTO CENTRAL OKLAHOMA THIS MORNING AS IT DECAYS. HAVE LEFT POPS OUT OF THE FORECAST FOR TODAY BUT NOT FEELING OVERLY CONFIDENT ABOUT THIS DECISION. COULD SEE SOME REDEVELOPMENT ON THE OUTFLOW BOUNDARY CREATED BY THIS COMPLEX THIS AFTERNOON. ANOTHER THUNDERSTORM COMPLEX IS EXPECTED TO DEVELOP ACROSS WESTERN KANSAS AGAIN THIS AFTERNOON/EVENING AND MAKE A RUN AT NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS LATE TONIGHT INTO THURSDAY. DO HAVE POPS IN THE FORECAST TO ACCOUNT FOR THIS FEATURE AS THE MODELS HAVE BEEN CONSISTENTLY SHOWING THIS FOR SEVERAL RUNS. THE UPPER LEVEL RIDGE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE WEEKEND. THERE ARE SOME SIGNS THAT THERE MAY BE ENOUGH WEAKNESS IN THE RIDGE THAT SOME ISOLATED THUNDERSTORMS WILL BE POSSIBLE SATURDAY AND SUNDAY AFTERNOONS IN THE FAVORED TERRAIN AREAS OF SOUTHEAST OKLAHOMA INTO NORTHWEST ARKANSAS. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...14
AREA FORECAST DISCUSSION
NWS NORMAN OK
1140 AM CDT WED JUN 19 2013 .UPDATE... MADE A FEW MINOR TWEAKS TO THE GOING FORECAST. SOUTHERN END OF ONGOING STORM COMPLEX HAS MOVED INTO FAR WESTERN NORTH TEXAS. HAVE UPPED POPS TO LIKELY OVER THIS AREA AND MAINTAIN CHANCE POPS THROUGH LATE AFTERNOON. THEREAFTER...ONLY ISOLATED ACTIVITY IS EXPECTED BEFORE ADDITIONAL STORMS DEVELOP THIS EVENING AND OVERNIGHT. GIVEN SUBSTANTIAL CLOUD COVER HAS LIMITED HEATING ACROSS SOUTHWEST OKLAHOMA AND NORTH TEXAS...HAVE TWEAKED HOURLY TEMPERATURES TO REFLECT THIS. STILL EXPECT ONCE CLOUDS CLEAR...QUICK WARMING WILL ENSUE AND WILL MAINTAIN GOING HIGH TEMPERATURES THIS AFTERNOON. OTHERWISE...ONLY MINOR UPDATES WERE MADE TO HOURLY WINDS AND DEWPOINTS. THE MAIN CONCERN WILL BE FOR LOCALIZED HEAVY RAINFALL WHICH MAY LEAD TO FLASH FLOODING OVER PARTS OF WESTERN NORTH TEXAS. OTHERWISE...THE DAY SHOULD BE RELATIVELY QUIET AND MILD. && .DISCUSSION... && .PREV DISCUSSION... /ISSUED 652 AM CDT WED JUN 19 2013/ DISCUSSION... 12Z AVIATION DISCUSSION FOLLOWS BELOW... AVIATION... THUNDERSTORMS CONTINUE TO MOVE S/SE ACROSS THE TEXAS PANHANDLE AND FAR NORTHWESTERN OKLAHOMA THIS MORNING. THIS ACTIVITY WILL CONTINUE TO IMPACT KWWR AND KGAG THROUGH MID TO LATE MORNING. THIS ACTIVITY WILL SLOWLY DISSIPATE THROUGH NOON. THUNDERSTORM CHANCES WILL THEN INCREASE THROUGH THE AFTERNOON AND EVENING ACROSS NORTHERN OKLAHOMA. LOW CONFIDENCE ON TIMING AND LOCATION... THEREFORE...HAVE LEFT OUT A MENTION IN THE KWWR...KGAG...AND KPNC TAFS. THERE REMAINS A CHANCE OF MVFR STRATUS ACROSS THE SOUTHERN PORTIONS OF OKLAHOMA AND WESTERN NORTH TEXAS THIS AFTERNOON...BUT CONFIDENCE REMAINS LOW...SO KEPT CEILINGS AT VFR AT THE MOMENT. WINDS WILL REMAIN OUT OF THE SOUTH...PICKING UP THROUGH NOON...WITH AFTERNOON GUSTS 20 TO 25 KTS AT TIMES. JTK PREV DISCUSSION... /ISSUED 347 AM CDT WED JUN 19 2013/ DISCUSSION... CURRENTLY...A WEAK MCS CONTINUES TO MOVE EASTWARD ACROSS SRN KS AND NWRN OK. THIS AREA OF CONVECTION REMAINS FOCUSED ALONG A LOW- LEVEL MOISTURE/THETA E AXIS POSITIONED ALONG/NEAR THE WRN KS/OK BORDER. OVERALL...MESOSCALE GUIDANCE HAS HAD A DIFFICULT GO THIS MORNING IN THE TRACK AND INTENSITY OF THESE STORMS. CURRENT THOUGHTS LEAN TOWARD THE MCS WEAKENING OVER THE NEXT FEW HOURS AS IT CONTINUES TO TRACK EASTWARD. CONDITIONS ARE LESS FAVORABLE FOR MCS MAINTENANCE ACROSS NRN AND CENTRAL OK...WHERE THE MOISTURE PROFILE IS LESS FAVORABLE AND MID-LEVEL LAPSE RATES WEAKEN CONSIDERABLY. THERE IS DECENT DEEP LAYER SHEAR...30-40KTS SPREAD INTO CENTRAL OK...BUT MUCAPES REMAIN LOW FOR MCS SUPPORT...700 TO 1000 J/KG. OVERALL...THE NEXT 12 TO 24 HOURS WILL POSE A FAIRLY DECENT CHALLENGE FORECASTWISE. THE RECENT 06Z RUN OF THE HRRR REVISES ITS PREVIOUS FORECAST...WITH CONVECTION DEVELOPING BEHIND THE MAIN LINE AND SURGING SOUTHWARD THROUGH THE TX PANHANDLE THROUGH THE MORNING. CURRENT RADAR TRENDS SUGGEST THIS MIGHT BE A POSSIBLE SCENARIO...AS NEW CONVECTION HAS STARTED TO DEVELOP OVER THE PAST HOUR...SINCE 230 AM...ACROSS SERN CO AND THE OK PANHANDLE. FOR THE MOMENT...WILL CONTINUE WITH CHANCE POPS ACROSS NWRN OK THROUGH THE MORNING HOURS. FOR THIS AFTERNOON...THE SHALLOW 500MB RIDGE WILL CONTINUE TO SHIFT/TILT EASTWARD ACROSS THE SRN PLAINS...WHILE ANOTHER LOW AMPLITUDE SHORTWAVE TRAVERSES THE REGION. WITH UPPER LEVEL SUPPORT...AND THE PAC NW TROUGH DIGGING EASTWARD...A STOUT SFC TROUGH/FRONT WILL EXTEND THE LENGTH OF THE FRONT RANGE INTO THE CENTRAL HIGH PLAINS. THIS COULD RESULT IN SOME WEAK SCATTERED CONVECTION LATER THIS AFTERNOON AND OVERNIGHT ACROSS NRN OK...PRIMARILY WELL NORTH OF THE I-40 AND I-44 CORRIDORS. EXPECT COVERAGE TO BE LIMITED WITH THIS SYSTEM...WITH MOST LOCATIONS LIKELY REMAINING DRY AFTER THIS MORNING. FOR THE REMAINDER OF THE WEEK...UPPER LEVEL RIDGING WILL TAKE HOLD...WITH SOUTH/SOUTHWEST FLOW SETTING UP SLOWLY THROUGH THE WEEKEND. TEMPERATURES WILL WARM BACK UP...WITH AFTERNOON HIGHS WELL INTO THE 90S...APPROACHING THE 100S ACROSS SWRN OK AND WRN N TX. THERE COULD BE A FEW ISOLATED SHOWERS ACROSS FAR NWRN OK SUNDAY AS THE WRN TROUGH INTENSIFIES AND A SFC FRONT APPROACHES THE REGION...BUT AT THE MOMENT...EXPECT THE GOOD MAJORITY OF THE AREA TO REMAIN DRY THROUGH THE WEEKEND. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 85 69 89 71 / 10 10 10 0 HOBART OK 90 70 96 72 / 30 10 10 10 WICHITA FALLS TX 90 72 95 73 / 30 10 0 0 GAGE OK 87 69 96 73 / 20 20 10 10 PONCA CITY OK 85 69 88 72 / 10 30 30 10 DURANT OK 88 71 91 72 / 10 10 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 84/23
AREA FORECAST DISCUSSION
NWS TULSA OK
1034 AM CDT WED JUN 19 2013 .DISCUSSION... THUNDERSTORM COMPLEX CONTINUES TO DIVE SOUTH ACROSS TX PANHANDLE THIS MORNING WITH SOME ASSOCIATED ANVIL CIRRUS SPREADING INTO FAR WESTERN REACHES OF THE FORECAST AREA. IN ADDITION A RELATIVE MOIST AXIS FROM ARKLATEX INTO NC OK ASSOCIATED WITH LOWER CLOUDS AND WHILE AN ISOLATED STORM OR TWO MAY DEVELOP IN THIS AREA...FEEL THAT WITH RISING MID LEVEL HEIGHTS THE OVERALL COVERAGE/PROB TOO LOW TO INCLUDE IN FORECAST. THIS MAY BECOME FOCUS FOR OVERNIGHT STORM COMPLEX DEVELOPING OVER CENTRAL PLAINS WHICH WILL HAVE A HIGHER THREAT OF MOVING INTO EASTERN OK BY EARLY THU MORNING HOWEVER. OVERALL FORECAST APPEARS ON TRACK AND WILL MAKE UPDATES FOR LESS CLOUD COVER ACROSS EASTERN AREAS AND TO INCORPORATE HOURLY TRENDS. && .PREV DISCUSSION... /ISSUED 617 AM CDT WED JUN 19 2013/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. THUNDERSTORM CHANCES APPEAR TOO LOW TO MENTION AT NE OK TAF SITES AT THIS TIME. PREV DISCUSSION... /ISSUED 303 AM CDT WED JUN 19 2013/ DISCUSSION... A RIDGE OF HIGH PRESSURE ALOFT WILL BEGIN TO NUDGE INTO THE AREA FROM THE SOUTHWEST TODAY. BEFORE WE GET INTO SOMETHING OF A DRY PERIOD...THE AREA WILL HAVE TO CONTEND WITH A COUPLE OF THUNDERSTORM COMPLEXES. THIS MORNING THERE IS THUNDERSTORM COMPLEX THAT EXTENDS FROM SOUTHWEST KANSAS INTO THE TEXAS PANHANDLE. THE LATEST HRRR SHOWS THIS COMPLEX MOVING INTO CENTRAL OKLAHOMA THIS MORNING AS IT DECAYS. HAVE LEFT POPS OUT OF THE FORECAST FOR TODAY BUT NOT FEELING OVERLY CONFIDENT ABOUT THIS DECISION. COULD SEE SOME REDEVELOPMENT ON THE OUTFLOW BOUNDARY CREATED BY THIS COMPLEX THIS AFTERNOON. ANOTHER THUNDERSTORM COMPLEX IS EXPECTED TO DEVELOP ACROSS WESTERN KANSAS AGAIN THIS AFTERNOON/EVENING AND MAKE A RUN AT NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS LATE TONIGHT INTO THURSDAY. DO HAVE POPS IN THE FORECAST TO ACCOUNT FOR THIS FEATURE AS THE MODELS HAVE BEEN CONSISTENTLY SHOWING THIS FOR SEVERAL RUNS. THE UPPER LEVEL RIDGE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE WEEKEND. THERE ARE SOME SIGNS THAT THERE MAY BE ENOUGH WEAKNESS IN THE RIDGE THAT SOME ISOLATED THUNDERSTORMS WILL BE POSSIBLE SATURDAY AND SUNDAY AFTERNOONS IN THE FAVORED TERRAIN AREAS OF SOUTHEAST OKLAHOMA INTO NORTHWEST ARKANSAS. && .PRELIMINARY POINT TEMPS/POPS... TUL 90 71 90 74 / 10 10 20 10 FSM 90 68 92 71 / 10 10 10 0 MLC 89 70 91 73 / 0 0 10 10 BVO 88 69 88 72 / 10 20 30 10 FYV 86 64 87 68 / 10 10 10 0 BYV 87 65 88 68 / 10 10 10 10 MKO 88 69 89 72 / 10 10 20 10 MIO 89 68 88 71 / 10 20 30 10 F10 88 70 90 73 / 10 10 10 10 HHW 89 70 92 72 / 0 0 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...14 LONG TERM....07
AREA FORECAST DISCUSSION
NWS NORMAN OK
652 AM CDT WED JUN 19 2013 .DISCUSSION... 12Z AVIATION DISCUSSION FOLLOWS BELOW... && .AVIATION... THUNDERSTORMS CONTINUE TO MOVE S/SE ACROSS THE TEXAS PANHANDLE AND FAR NORTHWESTERN OKLAHOMA THIS MORNING. THIS ACTIVITY WILL CONTINUE TO IMPACT KWWR AND KGAG THROUGH MID TO LATE MORNING. THIS ACTIVITY WILL SLOWLY DISSIPATE THROUGH NOON. THUNDERSTORM CHANCES WILL THEN INCREASE THROUGH THE AFTERNOON AND EVENING ACROSS NORTHERN OKLAHOMA. LOW CONFIDENCE ON TIMING AND LOCATION... THEREFORE...HAVE LEFT OUT A MENTION IN THE KWWR...KGAG...AND KPNC TAFS. THERE REMAINS A CHANCE OF MVFR STRATUS ACROSS THE SOUTHERN PORTIONS OF OKLAHOMA AND WESTERN NORTH TEXAS THIS AFTERNOON...BUT CONFIDENCE REMAINS LOW...SO KEPT CEILINGS AT VFR AT THE MOMENT. WINDS WILL REMAIN OUT OF THE SOUTH...PICKING UP THROUGH NOON...WITH AFTERNOON GUSTS 20 TO 25 KTS AT TIMES. JTK && .PREV DISCUSSION... /ISSUED 347 AM CDT WED JUN 19 2013/ DISCUSSION... CURRENTLY...A WEAK MCS CONTINUES TO MOVE EASTWARD ACROSS SRN KS AND NWRN OK. THIS AREA OF CONVECTION REMAINS FOCUSED ALONG A LOW- LEVEL MOISTURE/THETA E AXIS POSITIONED ALONG/NEAR THE WRN KS/OK BORDER. OVERALL...MESOSCALE GUIDANCE HAS HAD A DIFFICULT GO THIS MORNING IN THE TRACK AND INTENSITY OF THESE STORMS. CURRENT THOUGHTS LEAN TOWARD THE MCS WEAKENING OVER THE NEXT FEW HOURS AS IT CONTINUES TO TRACK EASTWARD. CONDITIONS ARE LESS FAVORABLE FOR MCS MAINTENANCE ACROSS NRN AND CENTRAL OK...WHERE THE MOISTURE PROFILE IS LESS FAVORABLE AND MID-LEVEL LAPSE RATES WEAKEN CONSIDERABLY. THERE IS DECENT DEEP LAYER SHEAR...30-40KTS SPREAD INTO CENTRAL OK...BUT MUCAPES REMAIN LOW FOR MCS SUPPORT...700 TO 1000 J/KG. OVERALL...THE NEXT 12 TO 24 HOURS WILL POSE A FAIRLY DECENT CHALLENGE FORECASTWISE. THE RECENT 06Z RUN OF THE HRRR REVISES ITS PREVIOUS FORECAST...WITH CONVECTION DEVELOPING BEHIND THE MAIN LINE AND SURGING SOUTHWARD THROUGH THE TX PANHANDLE THROUGH THE MORNING. CURRENT RADAR TRENDS SUGGEST THIS MIGHT BE A POSSIBLE SCENARIO...AS NEW CONVECTION HAS STARTED TO DEVELOP OVER THE PAST HOUR...SINCE 230 AM...ACROSS SERN CO AND THE OK PANHANDLE. FOR THE MOMENT...WILL CONTINUE WITH CHANCE POPS ACROSS NWRN OK THROUGH THE MORNING HOURS. FOR THIS AFTERNOON...THE SHALLOW 500MB RIDGE WILL CONTINUE TO SHIFT/TILT EASTWARD ACROSS THE SRN PLAINS...WHILE ANOTHER LOW AMPLITUDE SHORTWAVE TRAVERSES THE REGION. WITH UPPER LEVEL SUPPORT...AND THE PAC NW TROUGH DIGGING EASTWARD...A STOUT SFC TROUGH/FRONT WILL EXTEND THE LENGTH OF THE FRONT RANGE INTO THE CENTRAL HIGH PLAINS. THIS COULD RESULT IN SOME WEAK SCATTERED CONVECTION LATER THIS AFTERNOON AND OVERNIGHT ACROSS NRN OK...PRIMARILY WELL NORTH OF THE I-40 AND I-44 CORRIDORS. EXPECT COVERAGE TO BE LIMITED WITH THIS SYSTEM...WITH MOST LOCATIONS LIKELY REMAINING DRY AFTER THIS MORNING. FOR THE REMAINDER OF THE WEEK...UPPER LEVEL RIDGING WILL TAKE HOLD...WITH SOUTH/SOUTHWEST FLOW SETTING UP SLOWLY THROUGH THE WEEKEND. TEMPERATURES WILL WARM BACK UP...WITH AFTERNOON HIGHS WELL INTO THE 90S...APPROACHING THE 100S ACROSS SWRN OK AND WRN N TX. THERE COULD BE A FEW ISOLATED SHOWERS ACROSS FAR NWRN OK SUNDAY AS THE WRN TROUGH INTENSIFIES AND A SFC FRONT APPROACHES THE REGION...BUT AT THE MOMENT...EXPECT THE GOOD MAJORITY OF THE AREA TO REMAIN DRY THROUGH THE WEEKEND. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 85 69 89 71 / 10 10 10 0 HOBART OK 90 70 96 72 / 30 10 10 10 WICHITA FALLS TX 90 72 95 73 / 10 10 0 0 GAGE OK 87 69 96 73 / 70 20 10 10 PONCA CITY OK 85 69 88 72 / 30 30 30 10 DURANT OK 88 71 91 72 / 10 10 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 11/04/04
AREA FORECAST DISCUSSION
NWS TULSA OK
617 AM CDT WED JUN 19 2013 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. THUNDERSTORM CHANCES APPEAR TOO LOW TO MENTION AT NE OK TAF SITES AT THIS TIME. && .PREV DISCUSSION... /ISSUED 303 AM CDT WED JUN 19 2013/ DISCUSSION... A RIDGE OF HIGH PRESSURE ALOFT WILL BEGIN TO NUDGE INTO THE AREA FROM THE SOUTHWEST TODAY. BEFORE WE GET INTO SOMETHING OF A DRY PERIOD...THE AREA WILL HAVE TO CONTEND WITH A COUPLE OF THUNDERSTORM COMPLEXES. THIS MORNING THERE IS THUNDERSTORM COMPLEX THAT EXTENDS FROM SOUTHWEST KANSAS INTO THE TEXAS PANHANDLE. THE LATEST HRRR SHOWS THIS COMPLEX MOVING INTO CENTRAL OKLAHOMA THIS MORNING AS IT DECAYS. HAVE LEFT POPS OUT OF THE FORECAST FOR TODAY BUT NOT FEELING OVERLY CONFIDENT ABOUT THIS DECISION. COULD SEE SOME REDEVELOPMENT ON THE OUTFLOW BOUNDARY CREATED BY THIS COMPLEX THIS AFTERNOON. ANOTHER THUNDERSTORM COMPLEX IS EXPECTED TO DEVELOP ACROSS WESTERN KANSAS AGAIN THIS AFTERNOON/EVENING AND MAKE A RUN AT NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS LATE TONIGHT INTO THURSDAY. DO HAVE POPS IN THE FORECAST TO ACCOUNT FOR THIS FEATURE AS THE MODELS HAVE BEEN CONSISTENTLY SHOWING THIS FOR SEVERAL RUNS. THE UPPER LEVEL RIDGE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE WEEKEND. THERE ARE SOME SIGNS THAT THERE MAY BE ENOUGH WEAKNESS IN THE RIDGE THAT SOME ISOLATED THUNDERSTORMS WILL BE POSSIBLE SATURDAY AND SUNDAY AFTERNOONS IN THE FAVORED TERRAIN AREAS OF SOUTHEAST OKLAHOMA INTO NORTHWEST ARKANSAS. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...12
AREA FORECAST DISCUSSION
NWS NORMAN OK
347 AM CDT WED JUN 19 2013 .DISCUSSION... CURRENTLY...A WEAK MCS CONTINUES TO MOVE EASTWARD ACROSS SRN KS AND NWRN OK. THIS AREA OF CONVECTION REMAINS FOCUSED ALONG A LOW- LEVEL MOISTURE/THETA E AXIS POSITIONED ALONG/NEAR THE WRN KS/OK BORDER. OVERALL...MESOSCALE GUIDANCE HAS HAD A DIFFICULT GO THIS MORNING IN THE TRACK AND INTENSITY OF THESE STORMS. CURRENT THOUGHTS LEAN TOWARD THE MCS WEAKENING OVER THE NEXT FEW HOURS AS IT CONTINUES TO TRACK EASTWARD. CONDITIONS ARE LESS FAVORABLE FOR MCS MAINTENANCE ACROSS NRN AND CENTRAL OK...WHERE THE MOISTURE PROFILE IS LESS FAVORABLE AND MID-LEVEL LAPSE RATES WEAKEN CONSIDERABLY. THERE IS DECENT DEEP LAYER SHEAR...30-40KTS SPREAD INTO CENTRAL OK...BUT MUCAPES REMAIN LOW FOR MCS SUPPORT...700 TO 1000 J/KG. OVERALL...THE NEXT 12 TO 24 HOURS WILL POSE A FAIRLY DECENT CHALLENGE FORECASTWISE. THE RECENT 06Z RUN OF THE HRRR REVISES ITS PREVIOUS FORECAST...WITH CONVECTION DEVELOPING BEHIND THE MAIN LINE AND SURGING SOUTHWARD THROUGH THE TX PANHANDLE THROUGH THE MORNING. CURRENT RADAR TRENDS SUGGEST THIS MIGHT BE A POSSIBLE SCENARIO...AS NEW CONVECTION HAS STARTED TO DEVELOP OVER THE PAST HOUR...SINCE 230 AM...ACROSS SERN CO AND THE OK PANHANDLE. FOR THE MOMENT...WILL CONTINUE WITH CHANCE POPS ACROSS NWRN OK THROUGH THE MORNING HOURS. FOR THIS AFTERNOON...THE SHALLOW 500MB RIDGE WILL CONTINUE TO SHIFT/TILT EASTWARD ACROSS THE SRN PLAINS...WHILE ANOTHER LOW AMPLITUDE SHORTWAVE TRAVERSES THE REGION. WITH UPPER LEVEL SUPPORT...AND THE PAC NW TROUGH DIGGING EASTWARD...A STOUT SFC TROUGH/FRONT WILL EXTEND THE LENGTH OF THE FRONT RANGE INTO THE CENTRAL HIGH PLAINS. THIS COULD RESULT IN SOME WEAK SCATTERED CONVECTION LATER THIS AFTERNOON AND OVERNIGHT ACROSS NRN OK...PRIMARILY WELL NORTH OF THE I-40 AND I-44 CORRIDORS. EXPECT COVERAGE TO BE LIMITED WITH THIS SYSTEM...WITH MOST LOCATIONS LIKELY REMAINING DRY AFTER THIS MORNING. FOR THE REMAINDER OF THE WEEK...UPPER LEVEL RIDGING WILL TAKE HOLD...WITH SOUTH/SOUTHWEST FLOW SETTING UP SLOWLY THROUGH THE WEEKEND. TEMPERATURES WILL WARM BACK UP...WITH AFTERNOON HIGHS WELL INTO THE 90S...APPROACHING THE 100S ACROSS SWRN OK AND WRN N TX. THERE COULD BE A FEW ISOLATED SHOWERS ACROSS FAR NWRN OK SUNDAY AS THE WRN TROUGH INTENSIFIES AND A SFC FRONT APPROACHES THE REGION...BUT AT THE MOMENT...EXPECT THE GOOD MAJORITY OF THE AREA TO REMAIN DRY THROUGH THE WEEKEND. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 85 69 89 71 / 10 10 10 0 HOBART OK 90 70 96 72 / 20 10 10 10 WICHITA FALLS TX 90 72 95 73 / 10 10 0 0 GAGE OK 87 69 96 73 / 50 20 10 10 PONCA CITY OK 85 69 88 72 / 10 30 30 10 DURANT OK 88 71 91 72 / 10 10 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 11/04
AREA FORECAST DISCUSSION
NWS TULSA OK
303 AM CDT WED JUN 19 2013 .DISCUSSION... A RIDGE OF HIGH PRESSURE ALOFT WILL BEGIN TO NUDGE INTO THE AREA FROM THE SOUTHWEST TODAY. BEFORE WE GET INTO SOMETHING OF A DRY PERIOD...THE AREA WILL HAVE TO CONTEND WITH A COUPLE OF THUNDERSTORM COMPLEXES. THIS MORNING THERE IS THUNDERSTORM COMPLEX THAT EXTENDS FROM SOUTHWEST KANSAS INTO THE TEXAS PANHANDLE. THE LATEST HRRR SHOWS THIS COMPLEX MOVING INTO CENTRAL OKLAHOMA THIS MORNING AS IT DECAYS. HAVE LEFT POPS OUT OF THE FORECAST FOR TODAY BUT NOT FEELING OVERLY CONFIDENT ABOUT THIS DECISION. COULD SEE SOME REDEVELOPMENT ON THE OUTFLOW BOUNDARY CREATED BY THIS COMPLEX THIS AFTERNOON. ANOTHER THUNDERSTORM COMPLEX IS EXPECTED TO DEVELOP ACROSS WESTERN KANSAS AGAIN THIS AFTERNOON/EVENING AND MAKE A RUN AT NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS LATE TONIGHT INTO THURSDAY. DO HAVE POPS IN THE FORECAST TO ACCOUNT FOR THIS FEATURE AS THE MODELS HAVE BEEN CONSISTENTLY SHOWING THIS FOR SEVERAL RUNS. THE UPPER LEVEL RIDGE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE WEEKEND. THERE ARE SOME SIGNS THAT THERE MAY BE ENOUGH WEAKNESS IN THE RIDGE THAT SOME ISOLATED THUNDERSTORMS WILL BE POSSIBLE SATURDAY AND SUNDAY AFTERNOONS IN THE FAVORED TERRAIN AREAS OF SOUTHEAST OKLAHOMA INTO NORTHWEST ARKANSAS. && .PRELIMINARY POINT TEMPS/POPS... TUL 90 71 90 74 / 10 10 20 10 FSM 90 68 92 71 / 10 10 10 0 MLC 89 70 91 73 / 0 0 10 10 BVO 88 69 88 72 / 10 20 30 10 FYV 86 64 87 68 / 10 10 10 0 BYV 87 65 88 68 / 10 10 10 10 MKO 88 69 89 72 / 10 10 20 10 MIO 89 68 88 71 / 10 20 30 10 F10 88 70 90 73 / 10 10 10 10 HHW 89 70 92 72 / 0 0 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...12 LONG TERM....10
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
422 PM EDT WED JUN 19 2013 .SYNOPSIS... COOLER HIGH PRESSURE CENTERED NEAR NEW YORK STATE WILL RIDGE SOUTHWARD TONIGHT AND THURSDAY. THIS HIGH WILL DRIFT TO NEAR BERMUDA AND INTO NEXT WEEK AS AN UPPER RIDGE BUILDS IN FROM THE WEST AS TEMPERATURES SLOWLY RISE. && .NEAR TERM /THROUGH THURSDAY/... 2030 UTC UPDATE...POPS WERE ADJUSTED IN THE THE NORTHERN NC MOUNTAINS AND THE UPPER SAVANNAH RIVER VALLEY THE LATEST PER RADAR TRENDS. AS OF 215 PM...A WEAK SHORT WAVE TROUGH IS FORECAST TO MOVE THROUGH THE AREA FROM NW TO SE LATE THIS AFTERNOON AND EARLY TONIGHT. THE BEST FORCING WILL BE OVER THE FAR EASTERN AREAS. HENCE...THE MODELS SHOW SOME LIGHT QPF RESPONSE THERE. THE LATEST HRRR SHOWS THE MOST SHOWER COVERAGE FROM THE NORTHERN MOUNTAINS...EAST THROUGH THE NORTHERN NC PIEDMONT. WILL MAKE A LAST MINUTE ADJUSTMENT ON THE POP FIELD TO REFLECT THAT IDEA. WIDELY SCT SHOWERS/THUNDERSTORMS ARE EXPECTED ELSEWHERE THROUGH THE MOUNTAINS DURING THE MID TO LATE AFTERNOON HOURS DUE TO WEAK UPSLOPE FLOW. CAPES SHOULD GENERALLY STAY BELOW 1000J AS SOMEWHAT LOWER DEWPOINTS CONTINUE TO ADVECT INTO THE REGION...SO NO SEVERE THREAT. THE SHOWERS ARE EXPECTED TO DISSIPATE DURING EVENING. OTHERWISE...THE OVERNIGHT SHOULD BE QUIET. MODEL TIME HEIGHTS SHOW LOW LEVEL MOISTURE INCREASING TOWARD SUNRISE AS MOISTURE FROM ATLANTIC ADVECTS INTO THE AREA. THEREFORE...EXPECT A PERIOD OF LOW CLOUDINESS EARLY THU...ESPECIALLY EAST OF I-26. ON THU...HIGH PRESSURE LOCATED OFF THE NEW ENGLAND COAST WILL REMAIN RIDGED INTO THE AREA PRODUCING AN EASTERLY WIND FLOW IN THE SOUTHERN APPALACHIANS. THE UPSLOPE FLOW IN THE MOUNTAINS SHOULD PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON HOURS. USING A BLEND OF MODELS PRODUCES MAX TEMPS ABOUT A CATEGORY BELOW AVERAGE ON THU. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 210 PM EDT WED...SHORT RANGE MODELS AGREE THAT THE REGION WILL REMAIN UNDER A WEAK MID LEVEL TROUGH...WITH RIDGING ACROSS THE SOUTHERN PLAINS AND ATLANTIC. AT THE SFC...A STATIONARY FRONT AND POSSIBLE FRONTAL WAVE WILL REMAIN ACROSS THE COASTAL PLAIN OF THE CAROLINAS. WEAK SFC RIDGING MAY REMAIN ACROSS THE SOUTHERN APPALACHIAN REGION. GIVEN THE SFC PATTERN...I WILL INDICATE PERSISTENT NE WINDS ACROSS THE FOOTHILLS AND PIEDMONT FOR FRIDAY AND SATURDAY. A BLEND OF MODEL GUIDANCE INDICATES THAT SKY COVER WILL REMAIN PARTLY TO MOSTLY CLOUDY THROUGH THE PERIOD. THE COMBINATION OF NE WINDS AND CLOUD COVER SHOULD YIELD TEMPERATURES 3 TO 5 DEGREES BELOW NORMAL. OVERALL...THE CHCS OF SHRA AND TSRA APPEARS UNFAVORABLE WITHIN THE CORRIDOR OF DEEP NE FLOW. IN FACT...MODEL CAPE FIELDS INDICATE LITTLE TO NO VALUES FOR SFC BASED PARCELS BETWEEN THE EAST FACING MTN SLOPES TO THE WESTERN PIEDMONT. I WILL INDICATE SCHC POPS FOR TS ACROSS THE EXTREME WESTERN NC MTNS ON FRI AND SAT. BY SAT...LLVL WINDS MAY VEER NE...POSSIBLY ALLOWING WEAK INSTABILITY ACROSS NE GA AND THE EASTERN PIEDMONT DURING THE LATE AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 240 PM EDT WED...A 591 DM H5 RIDGE WILL REMAIN DOMINANT OVER THE SE THROUGH THE MEDIUM RANGE PERIOD. ANTICIPATE A MAINLY DIURNAL TREND OF ISOLD TO SCATTERED AFTERNOON POPS THROUGH THE PERIOD...WITH THE MTNS BEING THE PRIMARY FOCUS. THE GFS IS THE MOST AGGRESSIVE IN BRINGING AN INVERTED COASTAL TROUGH BACK INLAND ALONG THE SAVANNAH ON SATURDAY...BUT THE OTHER OPERATIONAL AND ENSEMBLE MEAN SOLUTIONS KEEP THE SYSTEM ALONG THE IMMEDIATE COAST WITH THE RIDGE PERSISTING OVER THE WRN CAROLINAS. THE DIURNAL PATTERN OF ISOLD TO SCT SHOWERS AND THUNDERSTORMS SHOULD THUS CONTINUE SUN THROUGH TUE...WITH TEMPERATURES STEADILY WARMING UNDER THE UPPER RIDGE. EXPECT MAXES TO REACH CLIMATE NORMALS BY SUNDAY AND THEN EXCEED THEM MON AND TUE. THE UPPER RIDGE WILL BREAK DOWN IN MID WEEK AS A UPPER TROUGH FORMS OVER THE EAST COAST FOR THE SECOND HALF OF NEXT WEEK. THE GFS IS A BIT MORE PROGRESSIVE IN BRINGING THE TROUGH IN SOONER BY LATE WED OR WED NIGHT AS OPPOSED TO THUR OR FRI ON THE ECMWF. TEMPS ARE EXPECTED TO COOL SOME AS THIS TROUGH SETS UP WITH MORE CLOUDS AND HIGHER POPS. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... AT KCLT...SCT-BKN CU IS EXPECTED THROUGH THE AFTERNOON. CONVECTIVE CHANCES STILL SEEM TOO LOW TO MENTION IN THE TAF. SOME SHRA ASSOCIATED WITH A WEAK BACKDOOR FRONT WILL PROBABLY BE NOTED ON RADAR WELL TO THE NORTH OF THE FIELD LATE THIS AFTERNOON. MOST GUIDANCE SUGGESTS THAT STRATUS WILL ARRIVE FROM THE E-NE LATE TONIGHT. HENCE...HAVE INTRODCUED A BKN016 BEGINNING AT 11Z. THE STRATUS SHOULD THEN SCT BY 15Z. ELSEWHERE...IT APPEARS CONVECTIVE CHANCES WILL BE MOSTLY LIMITED TO WIDELY SCATTERED SHOWERS/THUDNERSTORMS OVER THE MOUNTAINS AND NC FOOTHILLS. HOWEVER...CHANCES TOO LOW TO MENTION EXCEPT FOR A VCSH AT KAVL LATE THIS AFTERNOON. BKN VFR CU WILL SCT THIS EVENING. GUIDANCE IS ADVERTISING A STRATUS DECK TO ARRIVE FROM THE E-NE LATE TONIGHT AND IS EXPECTED TO AFFECT ALL AIRFIELDS WITH AT LEAST MVFR CIGS FOR SEVERAL HOURS EARLY THU...EXCEPT KAND. OUTLOOK...INCREASING MOISTURE TOWARDS THE END OF THE WORK WEEK WILL ALLOW DIURNAL CONVECTION TO DEVELOP EACH AFTERNOON....MAINLY OVER THE MOUNTAINS. GENRALLY VFR CONDITIONS ARE EXPECTED EXCEPT SOME EARLY MORNING STRATUS IS POSSIBLE EACH DAY. DEEP ATLANTIC MOISTURE WILL ARRIVE THIS WEEKEND PROMOTING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS AND MORE RESTRICTIONS. CONFIDENCE TABLE... 20-02Z 02-08Z 08-14Z 14-20Z KCLT HIGH 100% HIGH 100% HIGH 89% HIGH 95% KGSP HIGH 100% HIGH 100% HIGH 86% HIGH 95% KAVL HIGH 100% HIGH 94% HIGH 89% HIGH 91% KHKY HIGH 100% HIGH 100% MED 72% HIGH 96% KGMU HIGH 100% HIGH 100% HIGH 86% HIGH 98% KAND HIGH 100% HIGH 88% HIGH 81% HIGH 98% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...DEO NEAR TERM...JAT/LG SHORT TERM...NED LONG TERM...DEO AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
327 PM EDT WED JUN 19 2013 .SYNOPSIS... COOLER HIGH PRESSURE CENTERED NEAR NEW YORK STATE WILL RIDGE SOUTHWARD TONIGHT AND THURSDAY. THIS HIGH WILL DRIFT TO NEAR BERMUDA AND INTO NEXT WEEK AS AN UPPER RIDGE BUILDS IN FROM THE WEST AS TEMPERATURES SLOWLY RISE. && .NEAR TERM /THROUGH THURSDAY/... 1930 UTC UPDATE...SKY COVER HAS BEEN UPDATED FROM THE LATEST VISIBLE SATELLITE IMAGERY. POPS WERE RAISED IN THE THE NORTHERN NC MOUNTAINS...AND THE UPPER SAVANNAH RIVER VALLEY...PER RADAR TRENDS. AS OF 215 PM...A WEAK SHORT WAVE TROUGH IS FORECAST TO MOVE THROUGH THE AREA FROM NW TO SE LATE THIS AFTERNOON AND EARLY TONIGHT. THE BEST FORCING WILL BE OVER THE FAR EASTERN AREAS. HENCE...THE MODELS SHOW SOME LIGHT QPF RESPONSE THERE. THE LATEST HRRR SHOWS THE MOST SHOWER COVERAGE FROM THE NORTHERN MOUNTAINS...EAST THROUGH THE NORTHERN NC PIEDMONT. WILL MAKE A LAST MINUTE ADJUSTMENT ON THE POP FIELD TO REFLECT THAT IDEA. WIDELY SCT SHOWERS/THUNDERSTORMS ARE EXPECTED ELSEWHERE THROUGH THE MOUNTAINS DURING THE MID TO LATE AFTERNOON HOURS DUE TO WEAK UPSLOPE FLOW. CAPES SHOULD GENERALLY STAY BELOW 1000J AS SOMEWHAT LOWER DEWPOINTS CONTINUE TO ADVECT INTO THE REGION...SO NO SEVERE THREAT. THE SHOWERS ARE EXPECTED TO DISSIPATE DURING EVENING. OTHERWISE...THE OVERNIGHT SHOULD BE QUIET. MODEL TIME HEIGHTS SHOW LOW LEVEL MOISTURE INCREASING TOWARD SUNRISE AS MOISTURE FROM ATLANTIC ADVECTS INTO THE AREA. THEREFORE...EXPECT A PERIOD OF LOW CLOUDINESS EARLY THU...ESPECIALLY EAST OF I-26. ON THU...HIGH PRESSURE LOCATED OFF THE NEW ENGLAND COAST WILL REMAIN RIDGED INTO THE AREA PRODUCING AN EASTERLY WIND FLOW IN THE SOUTHERN APPALACHIANS. THE UPSLOPE FLOW IN THE MOUNTAINS SHOULD PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON HOURS. USING A BLEND OF MODELS PRODUCES MAX TEMPS ABOUT A CATEGORY BELOW AVERAGE ON THU. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 210 PM EDT WED...SHORT RANGE MODELS AGREE THAT THE REGION WILL REMAIN UNDER A WEAK MID LEVEL TROUGH...WITH RIDGING ACROSS THE SOUTHERN PLAINS AND ATLANTIC. AT THE SFC...A STATIONARY FRONT AND POSSIBLE FRONTAL WAVE WILL REMAIN ACROSS THE COASTAL PLAIN OF THE CAROLINAS. WEAK SFC RIDGING MAY REMAIN ACROSS THE SOUTHERN APPALACHIAN REGION. GIVEN THE SFC PATTERN...I WILL INDICATE PERSISTENT NE WINDS ACROSS THE FOOTHILLS AND PIEDMONT FOR FRIDAY AND SATURDAY. A BLEND OF MODEL GUIDANCE INDICATES THAT SKY COVER WILL REMAIN PARTLY TO MOSTLY CLOUDY THROUGH THE PERIOD. THE COMBINATION OF NE WINDS AND CLOUD COVER SHOULD YIELD TEMPERATURES 3 TO 5 DEGREES BELOW NORMAL. OVERALL...THE CHCS OF SHRA AND TSRA APPEARS UNFAVORABLE WITHIN THE CORRIDOR OF DEEP NE FLOW. IN FACT...MODEL CAPE FIELDS INDICATE LITTLE TO NO VALUES FOR SFC BASED PARCELS BETWEEN THE EAST FACING MTN SLOPES TO THE WESTERN PIEDMONT. I WILL INDICATE SCHC POPS FOR TS ACROSS THE EXTREME WESTERN NC MTNS ON FRI AND SAT. BY SAT...LLVL WINDS MAY VEER NE...POSSIBLY ALLOWING WEAK INSTABILITY ACROSS NE GA AND THE EASTERN PIEDMONT DURING THE LATE AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 240 PM EDT WED...A 591 DM H5 RIDGE WILL REMAIN DOMINANT OVER THE SE THROUGH THE MEDIUM RANGE PERIOD. ANTICIPATE A MAINLY DIURNAL TREND OF ISOLD TO SCATTERED AFTERNOON POPS THROUGH THE PERIOD...WITH THE MTNS BEING THE PRIMARY FOCUS. THE GFS IS THE MOST AGGRESSIVE IN BRINGING AN INVERTED COASTAL TROUGH BACK INLAND ALONG THE SAVANNAH ON SATURDAY...BUT THE OTHER OPERATIONAL AND ENSEMBLE MEAN SOLUTIONS KEEP THE SYSTEM ALONG THE IMMEDIATE COAST WITH THE RIDGE PERSISTING OVER THE WRN CAROLINAS. THE DIURNAL PATTERN OF ISOLD TO SCT SHOWERS AND THUNDERSTORMS SHOULD THUS CONTINUE SUN THROUGH TUE...WITH TEMPERATURES STEADILY WARMING UNDER THE UPPER RIDGE. EXPECT MAXES TO REACH CLIMATE NORMALS BY SUNDAY AND THEN EXCEED THEM MON AND TUE. THE UPPER RIDGE WILL BREAK DOWN IN MID WEEK AS A UPPER TROUGH FORMS OVER THE EAST COAST FOR THE SECOND HALF OF NEXT WEEK. THE GFS IS A BIT MORE PROGRESSIVE IN BRINGING THE TROUGH IN SOONER BY LATE WED OR WED NIGHT AS OPPOSED TO THUR OR FRI ON THE ECMWF. TEMPS ARE EXPECTED TO COOL SOME AS THIS TROUGH SETS UP WITH MORE CLOUDS AND HIGHER POPS. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... AT KCLT...SCT-BKN CU IS EXPECTED THROUGH THE AFTERNOON. CONVECTIVE CHANCES STILL SEEM TOO LOW TO MENTION IN THE TAF. SOME SHRA ASSOCIATED WITH A WEAK BACKDOOR FRONT WILL PROBABLY BE NOTED ON RADAR WELL TO THE NORTH OF THE FIELD LATE THIS AFTERNOON. MOST GUIDANCE SUGGESTS THAT STRATUS WILL ARRIVE FROM THE E-NE LATE TONIGHT. HENCE...HAVE INTRODCUED A BKN016 BEGINNING AT 11Z. THE STRATUS SHOULD THEN SCT BY 15Z. ELSEWHERE...IT APPEARS CONVECTIVE CHANCES WILL BE MOSTLY LIMITED TO WIDELY SCATTERED SHOWERS/THUDNERSTORMS OVER THE MOUNTAINS AND NC FOOTHILLS. HOWEVER...CHANCES TOO LOW TO MENTION EXCEPT FOR A VCSH AT KAVL LATE THIS AFTERNOON. BKN VFR CU WILL SCT THIS EVENING. GUIDANCE IS ADVERTISING A STRATUS DECK TO ARRIVE FROM THE E-NE LATE TONIGHT AND IS EXPECTED TO AFFECT ALL AIRFIELDS WITH AT LEAST MVFR CIGS FOR SEVERAL HOURS EARLY THU...EXCEPT KAND. OUTLOOK...INCREASING MOISTURE TOWARDS THE END OF THE WORK WEEK WILL ALLOW DIURNAL CONVECTION TO DEVELOP EACH AFTERNOON....MAINLY OVER THE MOUNTAINS. GENRALLY VFR CONDITIONS ARE EXPECTED EXCEPT SOME EARLY MORNING STRATUS IS POSSIBLE EACH DAY. DEEP ATLANTIC MOISTURE WILL ARRIVE THIS WEEKEND PROMOTING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS AND MORE RESTRICTIONS. CONFIDENCE TABLE... 19-01Z 01-07Z 07-13Z 13-19Z KCLT HIGH 100% HIGH 100% HIGH 86% HIGH 91% KGSP HIGH 92% HIGH 100% HIGH 86% HIGH 91% KAVL HIGH 100% HIGH 95% HIGH 84% HIGH 90% KHKY HIGH 100% HIGH 100% MED 70% HIGH 96% KGMU HIGH 92% HIGH 100% HIGH 86% HIGH 96% KAND HIGH 100% HIGH 95% HIGH 85% HIGH 98% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...DEO NEAR TERM...JAT/LG SHORT TERM...NED LONG TERM...DEO AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
237 PM EDT WED JUN 19 2013 .SYNOPSIS... COOLER HIGH PRESSURE CENTERED NEAR NEW YORK STATE WILL RIDGE SOUTHWARD TONIGHT AND THURSDAY. THIS HIGH WILL DRIFT TO NEAR BERMUDA AND INTO NEXT WEEK AS AN UPPER RIDGE BUILDS IN FROM THE WEST AS TEMPERATURES SLOWLY RISE. && .NEAR TERM /THROUGH THURSDAY/... AS OF 215PM...A WEAK SHORT WAVE TROUGH IS FORECAST TO MOVE THROUGH THE AREA FROM NW TO SE LATE THIS AFTERNOON AND EARLY TONIGHT. THE BEST FORCING WILL BE OVER THE FAR EASTERN AREAS. HENCE...THE MODELS SHOW SOME LIGHT QPF RESPONSE THERE. THE LATEST HRRR SHOWS THE MOST SHOWER COVERAGE FROM THE NORTHERN MOUNTAINS...EAST THROUGH THE NORTHERN NC PIEDMONT. WILL MAKE A LAST MINUTE ADJUSTMENT ON THE POP FIELD TO REFLECT THAT IDEA. WIDELY SCT SHOWERS/THUNDERSTORMS ARE EXPECTED ELSEWHERE THROUGH THE MOUNTAINS DURING THE MID TO LATE AFTERNOON HOURS DUE TO WEAK UPSLOPE FLOW. CAPES SHOULD GENERALLY STAY BELOW 1000J AS SOMEWHAT LOWER DEWPOINTS CONTINUE TO ADVECT INTO THE REGION...SO NO SEVERE THREAT. THE SHOWERS ARE EXPECTED TO DISSIPATE DURING EVENING. OTHERWISE...THE OVERNIGHT SHOULD BE QUIET. MODEL TIME HEIGHTS SHOW LOW LEVEL MOISTURE INCREASING TOWARD SUNRISE AS MOISTURE FROM ATLANTIC ADVECTS INTO THE AREA. THEREFORE...EXPECT A PERIOD OF LOW CLOUDINESS EARLY THU...ESPECIALLY EAST OF I-26. ON THU...HIGH PRESSURE LOCATED OFF THE NEW ENGLAND COAST WILL REMAIN RIDGED INTO THE AREA PRODUCING AN EASTERLY WIND FLOW IN THE SOUTHERN APPALACHIANS. THE UPSLOPE FLOW IN THE MOUNTAINS SHOULD PRODUCE SCATTERED SHOWERS AND THUDNERSTORMS DURING THE AFTERNOON HOURS. USING A BLEND OF MODELS PRODUCES MAX TEMPS ABOUT A CATEGORY BELOW AVERAGE ON THU. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 210 PM EDT WED...SHORT RANGE MODELS AGREE THAT THE REGION WILL REMAIN UNDER A WEAK MID LEVEL TROUGH...WITH RIDGING ACROSS THE SOUTHERN PLAINS AND ATLANTIC. AT THE SFC...A STATIONARY FRONT AND POSSIBLE FRONTAL WAVE WILL REMAIN ACROSS THE COASTAL PLAIN OF THE CAROLINAS. WEAK SFC RIDGING MAY REMAIN ACROSS THE SOUTHERN APPALACHIAN REGION. GIVEN THE SFC PATTERN...I WILL INDICATE PERSISTENT NE WINDS ACROSS THE FOOTHILLS AND PIEDMONT FOR FRIDAY AND SATURDAY. A BLEND OF MODEL GUIDANCE INDICATES THAT SKY COVER WILL REMAIN PARTLY TO MOSTLY CLOUDY THROUGH THE PERIOD. THE COMBINATION OF NE WINDS AND CLOUD COVER SHOULD YIELD TEMPERATURES 3 TO 5 DEGREES BELOW NORMAL. OVERALL...THE CHCS OF SHRA AND TSRA APPEARS UNFAVORABLE WITHIN THE CORRIDOR OF DEEP NE FLOW. IN FACT...MODEL CAPE FIELDS INDICATE LITTLE TO NO VALUES FOR SFC BASED PARCELS BETWEEN THE EAST FACING MTN SLOPES TO THE WESTERN PIEDMONT. I WILL INDICATE SCHC POPS FOR TS ACROSS THE EXTREME WESTERN NC MTNS ON FRI AND SAT. BY SAT...LLVL WINDS MAY VEER NE...POSSIBLY ALLOWING WEAK INSTABILITY ACROSS NE GA AND THE EASTERN PIEDMONT DURING THE LATE AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 240 PM EDT WED...A 591 DM H5 RIDGE WILL REMAIN DOMINANT OVER THE SE THROUGH THE MEDIUM RANGE PERIOD. ANTICIPATE A MAINLY DIURNAL TREND OF ISOLD TO SCATTERED AFTERNOON POPS THROUGH THE PERIOD...WITH THE MTNS BEING THE PRIMARY FOCUS. THE GFS IS THE MOST AGGRESSIVE IN BRINGING AN INVERTED COASTAL TROUGH BACK INLAND ALONG THE SAVANNAH ON SATURDAY...BUT THE OTHER OPERATIONAL AND ENSEMBLE MEAN SOLUTIONS KEEP THE SYSTEM ALONG THE IMMEDIATE COAST WITH THE RIDGE PERSISTING OVER THE WRN CAROLINAS. THE DIURNAL PATTERN OF ISOLD TO SCT SHOWERS AND THUNDERSTORMS SHOULD THUS CONTINUE SUN THROUGH TUE...WITH TEMPERATURES STEADILY WARMING UNDER THE UPPER RIDGE. EXPECT MAXES TO REACH CLIMATE NORMALS BY SUNDAY AND THEN EXCEED THEM MON AND TUE. THE UPPER RIDGE WILL BREAK DOWN IN MID WEEK AS A UPPER TROUGH FORMS OVER THE EAST COAST FOR THE SECOND HALF OF NEXT WEEK. THE GFS IS A BIT MORE PROGRESSIVE IN BRINGING THE TROUGH IN SOONER BY LATE WED OR WED NIGHT AS OPPOSED TO THUR OR FRI ON THE ECMWF. TEMPS ARE EXPECTED TO COOL SOME AS THIS TROUGH SETS UP WITH MORE CLOUDS AND HIGHER POPS. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... AT KCLT...SCT-BKN CU IS EXPECTED THROUGH THE AFTERNOON. CONVECTIVE CHANCES STILL SEEM TOO LOW TO MENTION IN THE TAF. SOME SHRA ASSOCIATED WITH A WEAK BACKDOOR FRONT WILL PROBABLY BE NOTED ON RADAR WELL TO THE NORTH OF THE FIELD LATE THIS AFTERNOON. MOST GUIDANCE SUGGESTS THAT STRATUS WILL ARRIVE FROM THE E-NE LATE TONIGHT. HENCE...HAVE INTRODCUED A BKN016 BEGINNING AT 11Z. THE STRATUS SHOULD THEN SCT BY 15Z. ELSEWHERE...IT APPEARS CONVECTIVE CHANCES WILL BE MOSTLY LIMITED TO WIDELY SCATTERED SHOWERS/THUDNERSTORMS OVER THE MOUNTAINS AND NC FOOTHILLS. HOWEVER...CHANCES TOO LOW TO MENTION EXCEPT FOR A VCSH AT KAVL LATE THIS AFTERNOON. BKN VFR CU WILL SCT THIS EVENING. GUIDANCE IS ADVERTISING A STRATUS DECK TO ARRIVE FROM THE E-NE LATE TONIGHT AND IS EXPECTED TO AFFECT ALL AIRFIELDS WITH AT LEAST MVFR CIGS FOR SEVERAL HOURS EARLY THU...EXCEPT KAND. OUTLOOK...INCREASING MOISTURE TOWARDS THE END OF THE WORK WEEK WILL ALLOW DIURNAL CONVECTION TO DEVELOP EACH AFTERNOON....MAINLY OVER THE MOUNTAINS. GENRALLY VFR CONDITIONS ARE EXPECTED EXCEPT SOME EARLY MORNING STRATUS IS POSSIBLE EACH DAY. DEEP ATLANTIC MOISTURE WILL ARRIVE THIS WEEKEND PROMOTING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS AND MORE RESTRICTIONS. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 89% HIGH 88% KGSP HIGH 85% HIGH 100% HIGH 89% HIGH 88% KAVL HIGH 100% HIGH 100% HIGH 81% HIGH 93% KHKY HIGH 100% HIGH 100% MED 71% HIGH 96% KGMU HIGH 92% HIGH 100% HIGH 89% HIGH 93% KAND HIGH 100% HIGH 100% HIGH 87% HIGH 92% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...DEO NEAR TERM...LG SHORT TERM...NED LONG TERM...DEO AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
155 AM EDT WED JUN 19 2013 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL CROSS THE REGION ON WEDNESDAY...BUT WITHOUT ENOUGH MOISTURE TO EXPECT MORE THAN ISOLATED SHOWERS. MOIST EASTERLY FLOW WILL THEN KEEP SOME RAIN CHANCES THRU LATE WEEK MAINLY OVER THE MOUNTAINS. HIGH PRESSURE WILL BUILD OVER THE AREA FOR THE WEEKEND...MAINTAINING A WARM AND MOIST AIRMASS WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH AFTERNOON. && .NEAR TERM /THROUGH TODAY/... 930 PM UPDATE...DUE TO LARGELY BOUNDARY-PARALLEL SHEAR...CELLS THAT INITIALLY FORMED AROUND SUNSET HAVE TRAINED ROUGHLY ALONG A GREENVILLE TO CHESTER LINE IN CONVERGENT ZONE NEAR THE FRONT. ACTIVITY NOW BEGINNING TO DIMINISH AS INSTABILITY WANES...BUT SOME PRECIP LIKELY TO CONTINUE FOR ANOTHER HOUR OR SO AT LEAST. HOWEVER WITH OUTFLOW PUSHING OUT ACRS GREENVILLE AND SPARTANBURG COUNTIES CAN/T RULE OUT A COUPLE OF ISOLATED SHOWERS FIRING FROM THE SRN PORTIONS OF THOSE COUNTIES SOUTH. NORTH OF THE CURRENT ACTIVITY PRECIP CHANCES ARE TOO SMALL TO MENTION THIS EVENING. STORMS ALONG THE UPSTREAM BOUNDARY OVER KY WOULD TAKE UNTIL AFTER MIDNIGHT TO REACH THE TN/NC BORDER...BUT THEY ARE ALREADY STRUGGLING IN THE MORE STABLE ENVIRONMENT THEY ARE ENTERING...SO DO NOT SEE A NEED TO REFLECT THESE STORMS IN POPS TONIGHT. TEMPS HAVE BEEN ON TRACK SO FAR THIS EVENING AND WILL MAINTAIN GOING LOWS. 730 PM UPDATE...PRECIP ACTIVITY NOW CONFINED TO THE PIEDMONT SHOULD CONTINUE TO MOVE OUT OF THE CWFA WITH FRONT PUSHING INTO THAT AREA. ACTIVITY GENERALLY WEAKENING WITH LOSS OF HEATING ANYWAY. RAP AS WELL AS LOCAL WRF MODEL DO NOT SHOW ANY FURTHER DEVELOPMENT THIS EVENING...AND WINDS ARE DRY AND DOWNSLOPING ANYWAY. STILL DO THINK SOME OF THE REMAINING CU IN EAST TN AND THE MTNS OF WNC WILL REMAIN AS PATCHY STRATUS FOR MUCH OF THE NIGHT...WITH CONVECTIVE DEBRIS SPREADING ACROSS THE SE HALF OF THE CWFA TOO. KEPT PCLDY-MCLDY SKIES OVERNIGHT AS A RESULT. AS OF 230 PM EDT TUESDAY...A BIT OF A TRICKY FCST THIS AFTERNOON AND EARLY EVENING. THE OVERALL PATTERN IS WELL AGREED UPON BY THE MODELS...HOWEVER CONFIDENCE IN THE EVOLUTION OF S/W ENERGY ACROSS THE CWFA IS NOT VERY HIGH DUE TO MODEL DIFFERENCES. THE LATEST RADAR SHOWS AN UNSTABLE AIRMASS TO THE WEST BECOMING INCREASINGLY UNSTABLE INTO THE WRN ZONES. VSBY SAY SHOW GOOD CLEARING AND HEATING TAKING PLACE...BUT IN A DEEPLY MOIST ATMOS SBCAPE VALUES WILL LIKELY REACH ONLY MOD LEVELS. THIS IS A LITTLE EVIDENT IN THE LOW TOP CONV SEEN TO THE WEST. IN ANY REGARD...WILL ANTICIPATE TSTMS DEVELOPING AHEAD OF THE WEAK COLD FRONT AND DEPENDING ON THE STRENGTH OF THE CROSS S/W ENERGY...SOME OF THESE COULD BECOME STRONG TO SEVERE THIS AFTERNOON. THE MAIN THREAT WOULD BE LARGE HAIL AND PERHAPS DAMAGING WINDS AS DRIER AIR WORKS INTO THE MLVLS. EXPECT A WIND SHIFT ACROSS THE MTNS AROUND 00Z AND INTO THE UPSTATE NEAR 05Z. THIS WILL SUPPRESS ANY ACTIVITY TO THE SOUTH WITH A LOWER THETA/E AIRMASS MIXING IN. SOME PATCHY DENSE FG IS POSSIBLE AROUND DAYBREAK IN THE MTN VALLEYS AS THE PGRAD IS NOT REAL TIGHT BEHIND THE FRONT AND BROADENS THROUGH 12Z. A CP HIGH WILL WORK SOUTH INTO THE OH VALLEY TOMORROW AND PUSH A BACKDOOR COLD FRONT INTO THE NRN ZONES BY THE AFTERNOON. THERE IS NOT MUCH MOISTURE AVAILABLE WITH THIS SYSTEM SO WILL EXPECT THE BEST PRECIP CHANCES ACROSS THE MTNS...WHERE AN E/LY UPSLOPE FLOW BRINGS IN ATL MOISTURE. POPS HAVE BEEN HELD TO SLIGHT/CHANCE ACROSS THE MTNS AND SLIGHT ELSEWHERE...WITH MAINLY -SHRA AND PERHAPS A MODERATE THUNDERSTORM OR TWO ACROSS THE FHILLS AND MTNS. MAX TEMPS SHOULD STILL BE A COUPLE DEGREES BELOW NORMAL WITH THE NE/LY SFC FLOW AND AIRMASS MIXING. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... AS OF 200 PM EDT TUESDAY...THE SHORT TERM WILL BE DOMINATED BY SURFACE HIGH PRESSURE THAT WILL SET UP CAMP OFF THE NEW ENGLAND COAST WHICH WILL REMAIN RIDGED SWD INTO THE SOUTHERN APPALACHIANS THROUGH FRI. THE UPPER AIR PATTERN WILL BE ALMOST INDETERMINATE IN THE DEEP SOUTH WITH VERY WEAK FLOW. THE AREA WILL BE BETWEEN A TROUGH WELL TO THE NE AND AN UPPER RIDGE OVER THE SOUTHERN PLAINS. HENCE...NO SIGNIFCANT UPPER FORCING IS ANTICIPATED. MODEL TIME HEIGHTS INDICATE THAT MOISTURE WILL REMAIN RELATIVELY HIGH IN THE BOUNDARY LAYER WITH DRYING ESSENTAILLY ABOVE 10KFT THROUGH THU NIGHT. HOWEVER...MOISTURE IN THE COLUMN IS FORECAST TO DECREASE ON FRI. HENCE...THE WEATHER SHOULD BE DRIVEN BY MAINLY BY THE LOW LEVEL WIND FLOW AND ANY MECHANICAL LIFT IT MUSTERS...PLUS DIURNAL HEATING. THEREFORE...MAINLY DIURNAL/SCATTERED CONVECTION IS EXPECTED PRIMARILY OVER THE MOUNTAINS...WITH PERHAPS A DOWN TICK IN COVERAGE ON FRI AFTERNOON DUE TO THE DRYER AIR. WITH THE WEAK UPSLOPE FLOW...SOME NOCTURNAL WIDELY SCATTERED SHOWERS WILL REMAIN POSSIBLE OVER THE MOUNTAINS WED/THU NIGHTS. USED AN ALLBLEND APPROACH TO TEMPERATURES WHICH PRODUCED MAX TEMPS ON THU AND FRI ABOUT A CATEGORY BELOW AVERAGE. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 2 PM TUESDAY...THE MAIN FEATURE FOR THE EXTENDED PERIOD IS A RIDGE OF HIGH PRESSURE THAT WILL SET UP OVER THE SOUTHEASTERN CONUS OVER THE WEEKEND AND INTO MONDAY. THE BERMUDA HIGH WILL REMAIN SITUATED OVER THE ATLANTIC OFF THE EAST COAST...SETTING UP A MOIST SOUTHEASTERLY TO SOUTHWESTERLY LOW-LEVEL FLOW REGIME FOR THE REGION. THIS WILL DRIVE MAINLY DIURNAL CONVECTION FOR THE PERIOD...WITH GREATER CHANCE POPS FAVORING THE HIGHER ELEVATIONS EACH AFTERNOON THROUGH THE MIDDLE OF NEXT WEEK. THE PERSISTENT RIDGE WILL ALLOW FOR A SLIGHT WARMING TREND...WITH TEMPS NEAR TO SLIGHTLY ABOVE AVERAGE BY THE END OF THE EXTENDED PERIOD. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...BORDERLINE MVFR TO VFR CONDITIONS ARE EXPECTED DURING THE OVERNIGHT HOURS AS A MOIST BOUNDARY LAYER WILL AID IN LOW STATUS PERSISTENCE...AND ALSO PROMPT POSSIBLE MVFR CONDITIONS FOR FOG DURING THE MID TO LATE MORNING HOURS. OTHERWISE...NORTHERLY WINDS WILL PERSIST THROUGH THE MORNING BEFORE SHIFTING SOMEWHAT EASTERLY BY AFTERNOON. CONDITIONS WILL IMPROVE DURING THE LATE MORNING TO AFTERNOON HOURS ON WEDNESDAY AS DRIER AIR ADVECTS IN FROM THE NORTH. HOWEVER...LOOK FOR SOME BKN TO SCT LOW/MID LEVEL CLOUDS TO PERSIST THROUGH THE PERIOD. KEPT ANY MENTION OF TSRA OUT OF THE TAF AS ANY INSTABILITY SHOULD REMAIN CAPPED OFF. ELSEWHERE...ALTHOUGH CIGS SHOULD GENERALLY REMAIN ABOVE 3KFT AT ALL SC SITES...SOME BRIEF LOWERING TO HIGH END MVFR LEVELS CANNOT BE RULED OUT AS CONVECTIVE DEBRIS REMAINS SCATTERED ACROSS A MOIST BOUNDARY LAYER. KEPT MENTION OF MVFR FOG AT ALL SITES THROUGH MID TO LATE MORNING DUE TO AMPLE LOW LEVEL MOISTURE AND CALMING NORTHERLY WINDS. OTHERWISE...CONDITIONS SHOULD IMPROVE TO VFR AT ALL SC SITES BEYOND WEDNESDAY MORNING. AS FOR THE NC SITES...WENT WITH PROB30 AT KAVL AND KHKY AS SHORT TERM CONVECTION ALLOWING GUIDANCE INDICATES SOME UPDRAFTS BEING ABLE TO OVERCOME THE CAP WITH THE AID OF MECHANICAL FORCING. BEYOND THAT...SOME LOW/MID LEVEL VFR CIGS ARE LIKELY AT THE NC SITES...WHILE FULL VFR MID/HIGH CLOUDS WILL PERSIST AT THE SC SITES THROUGH THE PERIOD. OUTLOOK...MOIST EASTERLY FLOW WILL SET UP WED NIGHT LEADING TO LOW STRATUS ACROSS MUCH OF THE AREA THU MORNING WITH RESTRICTIONS LIKELY. CONFIDENCE TABLE... 06-12Z 12-18Z 18-24Z 00-06Z KCLT HIGH 91% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 82% HIGH 94% HIGH 100% HIGH 100% KAVL HIGH 83% HIGH 99% HIGH 100% HIGH 100% KHKY MED 74% HIGH 94% HIGH 100% HIGH 100% KGMU MED 75% HIGH 92% HIGH 100% HIGH 100% KAND MED 74% HIGH 97% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...WIMBERLEY NEAR TERM...SBK/WIMBERLEY SHORT TERM...LG LONG TERM...VISIN AVIATION...CDG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
753 PM CDT THU JUN 20 2013 .UPDATE... WEAK MID LEVEL IMPULSE IN PLACE ACROSS THE MID STATE THIS EVENING. THIS HAS HELPED TO PRODUCE THE ISOL TO SCT SHOWER AND TSTM ACTIVITY EARLIER THIS AFTERNOON AND EVENING. ACTIVITY IS BEGINNING TO TAPER OFF AS WE CONTINUE TO LOSE OUR DAYTIME HEATING. LATEST 00Z LAPS INSTABILITY DATA SHOWING A MARKED DECREASE IN INSTABILITY LEVELS FROM 23Z TO 00Z. RADAR IS ALSO SHOWING A DECREASE IN INTENSITY AND IS FURTHER SUPPORTED BY AN HRRR CONVECTIVE DECREASE WITH TIME. WILL ISSUE UPDATE TO REMOVE THE LATE AFTERNOON WORDING. OTW...CONVECTION WILL STILL CONTINUE FOR ANOTHER HOUR OR TWO. ONCE CONVECTION COMPLETELY WINDS DOWN WILL REISSUE AGAIN AND REMOVE ALL CONVECTION FROM ZONES. REMAINDER OF THE GRIDDED DATA LOOKS TO BE IN GOOD SHAPE. UPDATE WILL BE ISSUED SHORTLY. && .PREV DISCUSSION... /ISSUED 623 PM CDT THU JUN 20 2013/ AVIATION 00Z DISCUSSION... WEAK MID LEVEL IMPULSE WILL MOVE EASTWARD ACROSS THE MID STATE THROUGH EARLY EVENING. AS A RESULT...ISOL SHOWERS AND TSTMS WILL BE POSSIBLE...GENERALLY PRIOR TO 03Z AND MAINLY ACROSS EASTERN AREAS OF THE MID STATE. AFT 03Z...SKIES WILL CLEAR WITH SOME SLIGHT BR VSBY REDUCTION FROM 06Z-12Z. SCT CONVECTIVE CU DECK AT 5KFT WILL RETURN ON FRIDAY AFTERNOON WITH ISOL STORMS POSSIBLE...MAINLY CSV AREA. PREV DISCUSSION... /ISSUED 304 PM CDT THU JUN 20 2013/ DISCUSSION... WEAK UPPER TROUGH REMAINS OVER THE REGION THIS AFTERNOON WITH SHORTWAVE JUST UPSTREAM. MODERATE MOISTURE SOURCE AND SLIGHTLY INCREASED INSTABILITY EXPECTED TO CONTINUE ISO-SCT CONVECTION INTO THE EARLY EVE. WEAK UPPER TROUGH WILL MAKE SLOW TRANSITION TO RIDGING INTO THE LATE WEEKEND...ALTHOUGH WEAK TROUGH AXIS DOES LINGER ALONG THE EASTERN SEABOARD. THIS WILL KEEP ANYTHING ORGANIZED FROM AFFECTING THE MID-SOUTH THUS CURRENT TREND WILL CONTINUE. MODERATE MOISTURE BELOW H7 AND DAYTIME HEATING/ELEVATED INSTABILITY WILL KEEP LARGELY DIURNAL ISO-SCT STORMS IN THE MIX THROUGH LATE SUNDAY. NO REAL APPRECIABLE CHANGES IN OVERALL PATTERN EARLY NEXT WEEK BUT CHANGES ARE IN SIGHT BY EARLY WED. UPPER RIDGE BREAKING DOWN MID-WEEK AS UPPER LOW SCOOTS NEAR THE US/CANADIAN BORDER. THIS WILL SHARPEN TROUGH OVER THE EASTERN US LATE WEEK...WITH AXIS SWINGING THROUGH POSSIBLY FRI. DAYTIME HEATING PUSHING TEMPS WELL INTO THE 80S TO AROUND 90 WILL PRODUCE DIURNAL CONVECTION THROUGH WED...WITH PCPN CHANCES RAMPING UP LATE IN THE WEEK WITH INCOMING TROUGH. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1140 PM CDT TUE JUN 18 2013 .UPDATE... 06Z TAF DISCUSSION. && .AVIATION... RADAR SHOWS CONVECTION NEAR PAH MOVING SOUTHWARD AND NOT EXPECTED TO AFFECT ANY AIRPORTS OVERNIGHT. CALM WINDS AND MOSTLY CLEAR SKIES WILL LEAD TO PATCHY MVFR/IFR FOG AT ALL TERMINALS TOWARDS SUNRISE. IMPROVEMENT TO VFR BY 13-14Z WITH SCT CUMULUS AND LIGHT NORTHEAST WINDS ON WEDNESDAY. SHAMBURGER && .PREV DISCUSSION... /ISSUED 811 PM CDT TUE JUN 18 2013/ UPDATE... BROKEN LINE OF SHOWERS AND TSTMS ATTEMPTING TO MOVE SOUTHWARD THROUGH WESTERN KY AT THIS TIME. THE ACTIVITY IS STILL SEVERAL COUNTIES NORTH OF THE TN/KY LINE BUT IS MOVING SOUTH. LATEST LAPS DATA SHOWING THAT CAPES DROP FROM 1400 J/KG VCNTY OF STORMS NOW...TO NEAR 600 J/KG ALONG THE TN/KY LINE. 850 MB FLOW IS GENERALLY NORTHERLY WHICH DOES NOT USUALLY CONDONE NOCTURNAL CONVECTIVE SUPPORT. FURTHERMORE...UPPER DIFFLUENCE IS LOOKING MINIMAL. HRRR OF LITTLE SUPPORT AND ONLY GOES OUT TO 03Z FOR NOW. WILL OPT TO MAKE NO CHANGES TO THE FCST AND KEEP THE 20 POPS GOING. WILL REMOVE THOSE POPS IF AND WHEN THE CONVECTION TO THE NORTH COMPLETELY DIES OUT. PREV DISCUSSION... /ISSUED 622 PM CDT TUE JUN 18 2013/ AVIATION... NORTHWEST FLOW IN PLACE THIS EVENING. DISTURBANCE ACROSS SOUTHERN IN WILL ATTEMPT TO DROP SOUTHWARD OVERNIGHT. THIS FEATURE SHOULD WEAKEN BUT AN ISOLATED TSTM OR TWO COULD FLIRT WITH CROSSING THE TN/KY BORDER LATE TONIGHT. OTW...SOME LIGHT FOG POSSIBLE TOWARD 12Z. ANOTHER DRY DAY WITH PARTIAL SUNSHINE EXPECTED FOR YOUR WEDNESDAY. PREV DISCUSSION... /ISSUED 228 PM CDT TUE JUN 18 2013/ DISCUSSION... FRONTAL BOUNDARY AND ASSOCIATED CONVECTION NOW WELL SOUTH OF MID STATE WITH SKIES BECOMING PARTLY SUNNY OVER MUCH OF THE CWA AT MID-AFTERNOON. RATHER SHARP SHORT WAVE ACROSS EASTERN IOWA THIS AFTERNOON WILL WORK SOUTHEASTWARD ALONG FRONTAL BOUNDARY THAT CURRENTLY EXTENDS FROM CENTRAL ILLINOIS ACROSS INDIANA INTO OHIO. ALREADY BEGINNING TO SEE SOME CONVECTION FIRING ALONG THAT BOUNDARY. SURFACE BOUNDARY PROGGED TO SINK SOUTHWARD THIS EVENING PRECEDING BY CONVECTION. FRONT WILL BE UNDERGOING FRONTOLYSIS BY THE TIME IT GETS THIS FAR SOUTH. EVEN THOUGH THE FRONT WILL BE WEAKENING I DONT FEEL CONFORTABLE NOT HAVING AT LEAST A MENTION OF ISOLATED THUNDER IN THE FORECAST FOR THE EVENING PERIOD. THERE STILL COULD BE ISOLATED THUNDER ON THE UPPER CUMBERLAND FOR A COUPLE OF HOURS AFTER MIDNIGHT. ALSO...AM EXPECTING LATE NIGHT PATCHY FOG TO DEVELOP. ON WEDNESDAY ANOTHER SHORT WAVE DROPS SOUTHEAST THAT COULD DEVELOP ISOLATED THUNDER ESPECIALLY DURING THE AFTERNOON AND EARLY EVENING. THURSDAY THROUGH THE WEEKEND WILL TURN OUT QUITE SUMMER-LIKE... RIGHT ON CUE WITH THE SUMMER SOLSTICE WHICH OCCURS FRIDAY JUNE 21ST AT 12:04 AM CDT. PLAINS UPPER RIDGE WILL REMAIN IN PLACE INTO THE WEEKEND WITH MID STATE REMAINING IN NORTHWEST FLOW. THIS MEANS A THUNDERSTORM CHANCE PRETTY MUCH EACH DAY. BOYD && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
340 PM CDT WED JUN 19 2013 .SHORT TERM... STRONG TO SEVERE CONVECTION IS ONGOING ACROSS THE BIG COUNTRY THIS AFTERNOON. THIS ACTIVITY IS OCCURRING IN THE VICINITY OF A SLOWLY SOUTHWARD MOVING SURFACE BOUNDARY DRAPED FROM NORTHWEST TO SOUTHEAST FROM NEAR LAMESA...TO SWEETWATER...TO BRECKENRIDGE. THE ENVIRONMENT IS QUITE UNSTABLE...AS EVIDENT FROM THE MLCAPE VALUES AT OR ABOVE 3000 J/KG. EFFECTIVE SHEAR VALUES OF NEAR 40 KTS HAVE MAINTAINED ORGANIZATION IN THIS CONVECTION WITH AT LEAST TWO SUPERCELLS EMBEDDED WITHIN THE CLUSTER. THIS ACTIVITY WILL CONTINUE TO MOVE TO THE SOUTHEAST THIS AFTERNOON...LINGERING INTO THE EVENING HOURS AND MAINLY AFFECTING THE BIG COUNTRY AND NORTHERN HEARTLAND. I HAVE NOTED THE HRRR INDICATING A LATE NIGHT PRECIP POTENTIAL FOR THE CONCHO VALLEY BUT I AM PLAYING THIS MORE CONSERVATIVE AND KEEPING THE FORECAST DRY FOR THE SOUTHERN COUNTIES. EXPECT OVERNIGHT LOWS GENERALLY IN THE LOWER 70S. HOWEVER...SOME RAIN COOLED AREAS WILL LIKELY DIP INTO THE 60S. TOMORROW...THE RIDGE IS EXPECTED TO TAKE CONTROL WITH HOT AND DRY CONDITIONS AREAWIDE. TEMPS WILL WARM INTO THE MID 90S ACROSS WEST CENTRAL TX WITH SOUTH WINDS OF 15-20 MPH. .LONG TERM... A STEADY-STATE PATTERN OF HOT AND DRY CONDITIONS ARE EXPECTED FOR WEST CENTRAL TEXAS...FRIDAY THROUGH THE MIDDLE OF NEXT WEEK. SUBTROPICAL RIDGE WILL BE OUR DOMINANT WEATHER INFLUENCE. THIS FEATURE WILL BUILD/EXPAND NORTHEAST FROM TEXAS TOWARD THE LOWER GREAT LAKES ON FRIDAY...AND WILL REMAIN ANCHORED OVER TEXAS THROUGH THE WEEKEND AND FIRST PART OF NEXT WEEK. BY THE MIDDLE OF NEXT WEEK...THE GFS AND ECMWF SHIFT THE CENTER OF THE UPPER HIGH NORTHWEST INTO NEW MEXICO AND COLORADO. ASSOCIATED SUBSIDENCE WILL HELP TO KEEP OUR RAIN CHANCES MINIMAL. THE LOW-LEVEL THERMAL RIDGE WILL REMAIN CENTERED TO OUR WEST... WITH SOME EASTWARD EXPANSION INDICATED NEXT WEEK. WITH THIS PATTERN AND INCREASED SOIL MOISTURE FROM RECENT RAINFALL AND EVAPOTRANSPIRATIVE EFFECTS...EXPECT LITTLE CHANGE IN THE DAILY TEMPERATURES THROUGH MONDAY. COULD HAVE MAXIMUM TEMPERATURES CREEPING UP A FEW DEGREES AS THE WEEK PROGRESSES HOWEVER. && .PRELIMINARY POINT TEMPS/POPS... ABILENE 73 95 73 95 73 / 20 0 0 0 0 SAN ANGELO 73 96 72 96 72 / 5 0 0 0 0 JUNCTION 71 94 71 93 71 / 0 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ JOHNSON/19
AREA FORECAST DISCUSSION
NWS AMARILLO TX
328 PM CDT WED JUN 19 2013 .DISCUSSION... MORNING CONVECTION HAS HELPED TO STABILIZE THE TEXAS AND OKLAHOMA PANHANDLES WHICH COULD KEEP PRECIPITATION CHANCES LIMITED THIS EVENING AND TONIGHT. CONVECTION IS ALREADY BEGINNING TO DEVELOP OVER THE NEW MEXICO MOUNTAINS THIS AFTERNOON. THE OUTFLOW FROM OUR STORMS THIS MORNING HAS PROGRESSED INTO THE EASTERN NEW MEXICO PLAINS BEFORE LOSING FORWARD MOMENTUM. THE RUC HRRR HAS BEEN ADVERTISING THAT CONVECTION WOULD DEVELOP ALONG THE WESTERN EXTENT OF THE OUTFLOW AND COMBINE WITH STORMS OVER NEW MEXICO BEFORE MOVING ACROSS THE CENTRAL AND SOUTHERN PANHANDLES. HOWEVER...THE RUC HRRR HAS CONSISTENTLY SHOWN THE MCS OVER NORTHWESTERN TEXAS TAKING A MUCH FURTHER EAST TRACK WHILE NOT PROGRESSING THE WESTERN OUTFLOW FAR ENOUGH WEST. THIS ARGUES THAT IF CONVECTION DOES FORM ALONG THE WESTERN OUTFLOW IT WILL HAVE TO STRUGGLE AGAINST THE OUTFLOW PROGRESS EASTWARD ENOUGH TO REACH THE PANHANDLES. HAVE KEPT POPS LOW AND USED AREAL QUANTIFIERS FOR THIS AFTERNOON THROUGH TONIGHT. IF THE STORMS OVER NEW MEXICO CAN OBTAIN STRONG COLD POOLS THEN THEY COULD OVERTAKE THE OUTFLOW AND TAP INTO ELEVATED INSTABILITY AS THEY MOVE INTO THE WESTERN TEXAS AND OKLAHOMA PANHANDLES. STRONG TO SEVERE STORMS MAY BE POSSIBLE IF THIS HAPPENS WITH HAIL AND DAMAGING WINDS AS THE PRIMARY SEVERE HAZARDS. ALSO GIVEN AMPLE PWATS ACROSS THE AREA...1.0 TO 1.2 INCHES...ANY STORM THAT MOVES INTO THE TEXAS OR OKLAHOMA PANHANDLE WILL HAVE A HEAVY RAIN POTENTIAL THAT COULD LEAD TO FLOODING AND FLASH FLOODING CONCERNS. ANY CONVECTIVE ACTIVITY THAT OCCURS ACROSS THE PANHANDLES THIS AFTERNOON/EVENING SHOULD DIMINISH AFTER MIDNIGHT. SATURDAY WILL SEE THE RIDGE AXIS SHIFT TO THE EAST OF THE PANHANDLES AND OPEN UP THE WESTERN PANHANDLES TO ANOTHER CHANCE FOR PRECIPITATION DURING THE AFTERNOON AND EVENING HOURS. WITH CAPE VALUES OF 1500 TO 2500 J/KG BUT WEAK DEEP LAYER SHEAR COULD LEAD TO A FEW STORMS BRIEFLY PULSING TO STRONG TO SEVERE LEVELS THEN COLLAPSING. THIS WILL KEEP THE RISK FOR DAMAGING WINDS AND HAIL AS THE PRIMARY HAZARDS. FRIDAY AFTERNOON WILL BE SIMILAR TO THURSDAY/S WITH DECENT CAPE VALUES BUT VERY WEAK DEEP LAYER SHEAR. STRONG TO BRIEFLY SEVERE STORMS WILL ONCE AGAIN BE POSSIBLE FOR THE WESTERN TEXAS AND OKLAHOMA PANHANDLES. SATURDAY THROUGH EARLY NEXT WEEK...WILL SEE THE RIDGE AXIS BUILD BACK OVER THE PANHANDLES TO KEEP PRECIPITATION CHANCES LIMITED. && .FIRE WEATHER... NEITHER ELEVATED NOR FIRE WEATHER CONDITIONS ARE EXPECTED FOR THE NEXT 7 DAYS GIVEN THE RECENT WETTING RAINS. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 15/14
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1249 PM CDT WED JUN 19 2013 .AVIATION... CONCERNS...ISOLATED THUNDERSTORMS POSSIBLE THIS AFTERNOON IN THE DFW METROPLEX AND WACO VICINITIES. A WARM FRONT THAT EXTENDED ALONG A LINE FROM 10 MILES NORTH OF KBKD /BRECKENRIDGE/ TO NEAR KACT /WACO/ TO 30 MILES NE OF KCLL /COLLEGE STATION/ WILL LIFT SLOWLY NORTHWARD THROUGH TONIGHT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THIS BOUNDARY THIS AFTERNOON AND THIS ACTIVITY IS EXPECTED TO DISSIPATE AS SUNSET APPROACHES. THE CHANCES AT THE INDIVIDUAL AIRPORTS IS LOW...SO HAVE JUST PLACED VCTS FOR THE 20Z TO 00Z PERIOD AT KACT /WACO/ AND LEFT OUT A MENTION OF VCTS IN THE METROPLEX TAFS FOR NOW. UPDATES FOR THE DFW METROPLEX TAFS MAY BE NEEDED LATER THIS AFTERNOON AS TOWERING CUMULUS IS ALREADY DEVELOPING. SOUTHEAST WINDS OF 5 TO 10 KNOTS THIS AFTERNOON AND EVENING WILL BECOME SOUTHERLY AT AROUND 15 KNOTS BY 16Z THURSDAY. 58 && .UPDATE... A WEAK...DIFFUSED FRONTAL BOUNDARY HAS LIFTED OVER THE WESTERN CWA AND NOW EXTENDS FROM NEAR BRECKENRIDGE SOUTHEAST TO SOUTH OF PALESTINE. EXPECT THIS BOUNDARY TO AID IN FOCUSING DEVELOPMENT THIS AFTERNOON ALONG AND NORTH OF THE FRONT. THE MCS OFF TO THE NORTHWEST HAD HELD TOGETHER FAIRLY WELL THIS MORNING...ESPECIALLY ON ITS SOUTHERN END. THE SYSTEM SHOULD BE ABLE TO MOVE INTO THE WESTERN CWA COUNTIES OF YOUNG AND STEPHENS AS EARLY AS 2 PM. ALTHOUGH OUR ATMOSPHERE IS UNSTABLE WITH GOOD MID LEVEL LAPSE RATES AND CAPE VALUES GENERALLY BETTER THAN 1800 J/KG...THE MCS WILL BE MOVING INTO AN ENVIRONMENT OF DECREASING BULK SHEAR WHICH WILL LIMIT THE POTENTIAL FOR ROTATING UPDRAFTS. CAPE VALUES ALONE SUGGEST SOME MARGINALLY SEVERE HAIL AND A POTENTIAL FOR 40-50 MPH DOWNBURST WINDS. 75 && .PREV DISCUSSION... /ISSUED 318 AM CDT WED JUN 19 2013/ THE ONLY MAJOR FORECASTING CHALLENGE WITH THIS PACKAGE WILL BE PATCHY FOG IN THE EASTERN ZONES THIS MORNING AND THUNDERSTORM CHANCES TODAY. LIGHT WIND AND DAMP GROUND ACROSS EAST TEXAS AND THE EASTERN PORTIONS OF NORTH TEXAS WILL RESULT IN PATCHY FOG THROUGH MID MORNING TODAY. IT APPEARS THAT MOST OF THE DENSE FOG SHOULD BE IN EAST TEXAS BUT A FEW NORTH TEXAS LOCATIONS MAY BRIEFLY FALL TO 1/2 MILE VISIBILITY. BY 11 AM...ANY FOG THAT DID DEVELOP WILL HAVE DISSIPATED. A COMPLEX OF STORMS...CURRENTLY ACROSS WESTERN OKLAHOMA AND THE PANHANDLE...WILL CONTINUE MOVING SOUTHEAST THROUGH THE EARLY MORNING HOURS. CLOUD TOPS IN THE SOUTHERN PORTION OF THE COMPLEX HAVE BEEN WARMING OVER THE PAST COUPLE OF HOURS AND THIS TREND WILL LIKELY CONTINUE. THE HRRR SEEMS TO HAVE THE MOST REASONABLE SOLUTION OF ALL MODELS BASED ON RADAR TRENDS OVER THE LAST FEW HOURS SO WILL FOLLOW IT FAIRLY CLOSELY. THEREFORE...EXPECT MOST OF THE WEST TEXAS ACTIVITY TO DISSIPATE BEFORE REACHING THE NORTHWEST ZONES AROUND MID MORNING...BUT WILL LEAVE 20 POPS IN TO ACCOUNT FOR ANY SHOWER OR STORM THAT MANAGES TO HOLD TOGETHER. BY THIS AFTERNOON...A FEW SHOWERS OR STORMS MAY DEVELOP ACROSS THE REGION AS TEMPERATURES WARM INTO THE 90S AND SOME LEFT OVER BOUNDARIES PROVIDE A FOCUS FOR LIFT. ANY STORMS THAT DO DEVELOP SHOULD BE DISORGANIZED PULSE STORMS DUE TO THE WEAK SHEARED AND WEAK FLOW ENVIRONMENT EXPECTED. ANY SHOWERS OR STORMS THAT DO DEVELOP THIS AFTERNOON WILL DISSIPATE WITH THE LOSS OF SURFACE HEATING AND INCREASING LARGE SCALE SUBSIDENCE FROM A BUILDING UPPER LEVEL RIDGE. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE ACROSS THE REGION THURSDAY THROUGH EARLY NEXT WEEK. THE GOOD NEWS IS THAT THE RIDGE WILL NEVER BECOME EXTREMELY STRONG AND AS A RESULT AFTERNOON HIGH TEMPERATURES SHOULD NOT BE TOO MUCH WARMER THAN SEASONAL NORMALS. EXPECT AFTERNOON HIGHS THROUGH EARLY NEXT WEEK GENERALLY IN THE LOWER AND MIDDLE 90S AND LOWS MOSTLY IN THE 70S. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 93 74 94 75 96 / 20 10 0 0 0 WACO, TX 94 72 94 73 95 / 20 10 0 0 0 PARIS, TX 89 70 92 71 94 / 20 10 5 0 5 DENTON, TX 92 71 94 72 96 / 20 10 0 0 0 MCKINNEY, TX 90 69 93 70 94 / 20 10 5 0 0 DALLAS, TX 93 75 94 76 95 / 20 10 0 0 0 TERRELL, TX 92 71 93 72 94 / 20 10 5 0 5 CORSICANA, TX 93 72 93 73 94 / 30 10 5 0 0 TEMPLE, TX 93 71 93 72 94 / 20 10 0 0 0 MINERAL WELLS, TX 93 70 94 71 96 / 30 5 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 58/75
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1116 AM CDT WED JUN 19 2013 .UPDATE... A WEAK...DIFFUSED FRONTAL BOUNDARY HAS LIFTED OVER THE WESTERN CWA AND NOW EXTENDS FROM NEAR BRECKENRIDGE SOUTHEAST TO SOUTH OF PALESTINE. EXPECT THIS BOUNDARY TO AID IN FOCUSING DEVELOPMENT THIS AFTERNOON ALONG AND NORTH OF THE FRONT. THE MCS OFF TO THE NORTHWEST HAD HELD TOGETHER FAIRLY WELL THIS MORNING...ESPECIALLY ON ITS SOUTHERN END. THE SYSTEM SHOULD BE ABLE TO MOVE INTO THE WESTERN CWA COUNTIES OF YOUNG AND STEPHENS AS EARLY AS 2 PM. ALTHOUGH OUR ATMOSPHERE IS UNSTABLE WITH GOOD MID LEVEL LAPSE RATES AND CAPE VALUES GENERALLY BETTER THAN 1800 J/KG...THE MCS WILL BE MOVING INTO AN ENVIRONMENT OF DECREASING BULK SHEAR WHICH WILL LIMIT THE POTENTIAL FOR ROTATING UPDRAFTS. CAPE VALUES ALONE SUGGEST SOME MARGINALLY SEVERE HAIL AND A POTENTIAL FOR 40-50 MPH DOWNBURST WINDS. 75 && .AVIATION... /12Z TAFS/ MVFR CONDS PREVAIL OVER A GOOD PORTION OF NORTH TEXAS WITH VIS GENERALLY AROUND 5SM. THERE ARE SOME AREAS OF DENSE FOG PRIMARILY IN THE LOWER VALLEYS BUT THIS SHOULD STAY OUT OF THE MAJOR AIRPORTS THROUGH MID MORNING. WILL PREVAIL VFR CONDS IN THE METROPLEX...ALTHOUGH AN AMD OR TWO MAY BE NEEDED IF VIS DROPS FURTHER THAN ANTICIPATED. A COMPLEX OF THUNDERSTORMS CONTINUES TO MOVE SOUTHEAST ACROSS WESTERN OKLAHOMA. THESE STORMS ARE LIKELY TO WEAKEN IN INTENSITY AS THEY APPROACH SO NO MENTION OF PRECIP IN THE CURRENT FORECAST. SOUTH WINDS AROUND 10KT EXPECTED THROUGH THE PERIOD. DUNN && .PREV DISCUSSION... /ISSUED 318 AM CDT WED JUN 19 2013/ THE ONLY MAJOR FORECASTING CHALLENGE WITH THIS PACKAGE WILL BE PATCHY FOG IN THE EASTERN ZONES THIS MORNING AND THUNDERSTORM CHANCES TODAY. LIGHT WIND AND DAMP GROUND ACROSS EAST TEXAS AND THE EASTERN PORTIONS OF NORTH TEXAS WILL RESULT IN PATCHY FOG THROUGH MID MORNING TODAY. IT APPEARS THAT MOST OF THE DENSE FOG SHOULD BE IN EAST TEXAS BUT A FEW NORTH TEXAS LOCATIONS MAY BRIEFLY FALL TO 1/2 MILE VISIBILITY. BY 11 AM...ANY FOG THAT DID DEVELOP WILL HAVE DISSIPATED. A COMPLEX OF STORMS...CURRENTLY ACROSS WESTERN OKLAHOMA AND THE PANHANDLE...WILL CONTINUE MOVING SOUTHEAST THROUGH THE EARLY MORNING HOURS. CLOUD TOPS IN THE SOUTHERN PORTION OF THE COMPLEX HAVE BEEN WARMING OVER THE PAST COUPLE OF HOURS AND THIS TREND WILL LIKELY CONTINUE. THE HRRR SEEMS TO HAVE THE MOST REASONABLE SOLUTION OF ALL MODELS BASED ON RADAR TRENDS OVER THE LAST FEW HOURS SO WILL FOLLOW IT FAIRLY CLOSELY. THEREFORE...EXPECT MOST OF THE WEST TEXAS ACTIVITY TO DISSIPATE BEFORE REACHING THE NORTHWEST ZONES AROUND MID MORNING...BUT WILL LEAVE 20 POPS IN TO ACCOUNT FOR ANY SHOWER OR STORM THAT MANAGES TO HOLD TOGETHER. BY THIS AFTERNOON...A FEW SHOWERS OR STORMS MAY DEVELOP ACROSS THE REGION AS TEMPERATURES WARM INTO THE 90S AND SOME LEFT OVER BOUNDARIES PROVIDE A FOCUS FOR LIFT. ANY STORMS THAT DO DEVELOP SHOULD BE DISORGANIZED PULSE STORMS DUE TO THE WEAK SHEARED AND WEAK FLOW ENVIRONMENT EXPECTED. ANY SHOWERS OR STORMS THAT DO DEVELOP THIS AFTERNOON WILL DISSIPATE WITH THE LOSS OF SURFACE HEATING AND INCREASING LARGE SCALE SUBSIDENCE FROM A BUILDING UPPER LEVEL RIDGE. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE ACROSS THE REGION THURSDAY THROUGH EARLY NEXT WEEK. THE GOOD NEWS IS THAT THE RIDGE WILL NEVER BECOME EXTREMELY STRONG AND AS A RESULT AFTERNOON HIGH TEMPERATURES SHOULD NOT BE TOO MUCH WARMER THAN SEASONAL NORMALS. EXPECT AFTERNOON HIGHS THROUGH EARLY NEXT WEEK GENERALLY IN THE LOWER AND MIDDLE 90S AND LOWS MOSTLY IN THE 70S. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 93 74 94 75 96 / 20 10 0 0 0 WACO, TX 94 72 94 73 95 / 20 10 0 0 0 PARIS, TX 91 70 92 71 94 / 20 10 5 0 5 DENTON, TX 93 71 94 72 96 / 20 10 0 0 0 MCKINNEY, TX 91 69 93 70 94 / 20 10 5 0 0 DALLAS, TX 93 75 94 76 95 / 20 10 0 0 0 TERRELL, TX 92 71 93 72 94 / 20 10 5 0 5 CORSICANA, TX 93 72 93 73 94 / 30 10 5 0 0 TEMPLE, TX 93 71 93 72 94 / 20 10 0 0 0 MINERAL WELLS, TX 93 70 94 71 96 / 30 5 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
659 AM CDT WED JUN 19 2013 .AVIATION... /12Z TAFS/ MVFR CONDS PREVAIL OVER A GOOD PORTION OF NORTH TEXAS WITH VIS GENERALLY AROUND 5SM. THERE ARE SOME AREAS OF DENSE FOG PRIMARILY IN THE LOWER VALLEYS BUT THIS SHOULD STAY OUT OF THE MAJOR AIRPORTS THROUGH MID MORNING. WILL PREVAIL VFR CONDS IN THE METROPLEX...ALTHOUGH AN AMD OR TWO MAY BE NEEDED IF VIS DROPS FURTHER THAN ANTICIPATED. A COMPLEX OF THUNDERSTORMS CONTINUES TO MOVE SOUTHEAST ACROSS WESTERN OKLAHOMA. THESE STORMS ARE LIKELY TO WEAKEN IN INTENSITY AS THEY APPROACH SO NO MENTION OF PRECIP IN THE CURRENT FORECAST. SOUTH WINDS AROUND 10KT EXPECTED THROUGH THE PERIOD. DUNN && .PREV DISCUSSION... /ISSUED 318 AM CDT WED JUN 19 2013/ THE ONLY MAJOR FORECASTING CHALLENGE WITH THIS PACKAGE WILL BE PATCHY FOG IN THE EASTERN ZONES THIS MORNING AND THUNDERSTORM CHANCES TODAY. LIGHT WIND AND DAMP GROUND ACROSS EAST TEXAS AND THE EASTERN PORTIONS OF NORTH TEXAS WILL RESULT IN PATCHY FOG THROUGH MID MORNING TODAY. IT APPEARS THAT MOST OF THE DENSE FOG SHOULD BE IN EAST TEXAS BUT A FEW NORTH TEXAS LOCATIONS MAY BRIEFLY FALL TO 1/2 MILE VISIBILITY. BY 11 AM...ANY FOG THAT DID DEVELOP WILL HAVE DISSIPATED. A COMPLEX OF STORMS...CURRENTLY ACROSS WESTERN OKLAHOMA AND THE PANHANDLE...WILL CONTINUE MOVING SOUTHEAST THROUGH THE EARLY MORNING HOURS. CLOUD TOPS IN THE SOUTHERN PORTION OF THE COMPLEX HAVE BEEN WARMING OVER THE PAST COUPLE OF HOURS AND THIS TREND WILL LIKELY CONTINUE. THE HRRR SEEMS TO HAVE THE MOST REASONABLE SOLUTION OF ALL MODELS BASED ON RADAR TRENDS OVER THE LAST FEW HOURS SO WILL FOLLOW IT FAIRLY CLOSELY. THEREFORE...EXPECT MOST OF THE WEST TEXAS ACTIVITY TO DISSIPATE BEFORE REACHING THE NORTHWEST ZONES AROUND MID MORNING...BUT WILL LEAVE 20 POPS IN TO ACCOUNT FOR ANY SHOWER OR STORM THAT MANAGES TO HOLD TOGETHER. BY THIS AFTERNOON...A FEW SHOWERS OR STORMS MAY DEVELOP ACROSS THE REGION AS TEMPERATURES WARM INTO THE 90S AND SOME LEFT OVER BOUNDARIES PROVIDE A FOCUS FOR LIFT. ANY STORMS THAT DO DEVELOP SHOULD BE DISORGANIZED PULSE STORMS DUE TO THE WEAK SHEARED AND WEAK FLOW ENVIRONMENT EXPECTED. ANY SHOWERS OR STORMS THAT DO DEVELOP THIS AFTERNOON WILL DISSIPATE WITH THE LOSS OF SURFACE HEATING AND INCREASING LARGE SCALE SUBSIDENCE FROM A BUILDING UPPER LEVEL RIDGE. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE ACROSS THE REGION THURSDAY THROUGH EARLY NEXT WEEK. THE GOOD NEWS IS THAT THE RIDGE WILL NEVER BECOME EXTREMELY STRONG AND AS A RESULT AFTERNOON HIGH TEMPERATURES SHOULD NOT BE TOO MUCH WARMER THAN SEASONAL NORMALS. EXPECT AFTERNOON HIGHS THROUGH EARLY NEXT WEEK GENERALLY IN THE LOWER AND MIDDLE 90S AND LOWS MOSTLY IN THE 70S. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 94 74 95 75 96 / 20 10 0 0 0 WACO, TX 94 72 94 73 95 / 20 10 0 0 0 PARIS, TX 91 70 92 71 94 / 20 10 5 0 5 DENTON, TX 94 71 95 72 96 / 20 10 0 0 0 MCKINNEY, TX 91 69 92 70 94 / 20 10 5 0 0 DALLAS, TX 94 75 94 76 96 / 20 10 0 0 0 TERRELL, TX 92 71 93 72 94 / 20 10 5 0 5 CORSICANA, TX 92 72 93 73 94 / 20 10 5 0 0 TEMPLE, TX 93 71 93 72 94 / 20 10 0 0 0 MINERAL WELLS, TX 93 70 94 70 96 / 20 5 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
318 AM CDT WED JUN 19 2013 .DISCUSSION... THE ONLY MAJOR FORECASTING CHALLENGE WITH THIS PACKAGE WILL BE PATCHY FOG IN THE EASTERN ZONES THIS MORNING AND THUNDERSTORM CHANCES TODAY. LIGHT WIND AND DAMP GROUND ACROSS EAST TEXAS AND THE EASTERN PORTIONS OF NORTH TEXAS WILL RESULT IN PATCHY FOG THROUGH MID MORNING TODAY. IT APPEARS THAT MOST OF THE DENSE FOG SHOULD BE IN EAST TEXAS BUT A FEW NORTH TEXAS LOCATIONS MAY BRIEFLY FALL TO 1/2 MILE VISIBILITY. BY 11 AM...ANY FOG THAT DID DEVELOP WILL HAVE DISSIPATED. A COMPLEX OF STORMS...CURRENTLY ACROSS WESTERN OKLAHOMA AND THE PANHANDLE...WILL CONTINUE MOVING SOUTHEAST THROUGH THE EARLY MORNING HOURS. CLOUD TOPS IN THE SOUTHERN PORTION OF THE COMPLEX HAVE BEEN WARMING OVER THE PAST COUPLE OF HOURS AND THIS TREND WILL LIKELY CONTINUE. THE HRRR SEEMS TO HAVE THE MOST REASONABLE SOLUTION OF ALL MODELS BASED ON RADAR TRENDS OVER THE LAST FEW HOURS SO WILL FOLLOW IT FAIRLY CLOSELY. THEREFORE...EXPECT MOST OF THE WEST TEXAS ACTIVITY TO DISSIPATE BEFORE REACHING THE NORTHWEST ZONES AROUND MID MORNING...BUT WILL LEAVE 20 POPS IN TO ACCOUNT FOR ANY SHOWER OR STORM THAT MANAGES TO HOLD TOGETHER. BY THIS AFTERNOON...A FEW SHOWERS OR STORMS MAY DEVELOP ACROSS THE REGION AS TEMPERATURES WARM INTO THE 90S AND SOME LEFT OVER BOUNDARIES PROVIDE A FOCUS FOR LIFT. ANY STORMS THAT DO DEVELOP SHOULD BE DISORGANIZED PULSE STORMS DUE TO THE WEAK SHEARED AND WEAK FLOW ENVIRONMENT EXPECTED. ANY SHOWERS OR STORMS THAT DO DEVELOP THIS AFTERNOON WILL DISSIPATE WITH THE LOSS OF SURFACE HEATING AND INCREASING LARGE SCALE SUBSIDENCE FROM A BUILDING UPPER LEVEL RIDGE. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE ACROSS THE REGION THURSDAY THROUGH EARLY NEXT WEEK. THE GOOD NEWS IS THAT THE RIDGE WILL NEVER BECOME EXTREMELY STRONG AND AS A RESULT AFTERNOON HIGH TEMPERATURES SHOULD NOT BE TOO MUCH WARMER THAN SEASONAL NORMALS. EXPECT AFTERNOON HIGHS THROUGH EARLY NEXT WEEK GENERALLY IN THE LOWER AND MIDDLE 90S AND LOWS MOSTLY IN THE 70S. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 94 74 95 75 96 / 20 10 0 0 0 WACO, TX 94 72 94 73 95 / 10 10 0 0 0 PARIS, TX 91 70 92 71 94 / 20 10 5 0 5 DENTON, TX 94 71 95 72 96 / 20 10 0 0 0 MCKINNEY, TX 91 69 92 70 94 / 20 10 5 0 0 DALLAS, TX 94 75 94 76 96 / 20 10 0 0 0 TERRELL, TX 92 71 93 72 94 / 20 10 5 0 5 CORSICANA, TX 92 72 93 73 94 / 20 10 5 0 0 TEMPLE, TX 93 71 93 72 94 / 10 10 0 0 0 MINERAL WELLS, TX 93 70 94 70 96 / 20 5 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 91/79
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
104 AM EDT WED JUN 19 2013 .SYNOPSIS... A WEAK COLD FRONT WILL DRIFT SOUTH INTO THE AREA LATER TONIGHT AND WEDNESDAY BEFORE DISSIPATING ALONG THE BLUE RIDGE WEDNESDAY EVENING. WEAK HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH LATER WEDNESDAY NIGHT AND THURSDAY...RESULTING IN SOMEWHAT DRIER WEATHER INTO THE END OF THE WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 1015 PM EDT TUESDAY... THE COLD FRONT WAS WELL SOUTH OF THE FORECAST AREA AT 02Z/10PM. SATELLITE PICTURES SHOWED SCATTERED CLOUDS OVER THE FORECAST AREA. ENOUGH CLEARING AND HIGH ENOUGH DEW POINTS TO ADD MORE FOG TO THE FORECAST FOR TONIGHT. LATEST WRF AND RAP GUIDANCE SUGGESTED LOW LEVEL MOISTURE AND A CHANCE OF SHOWERS OVER SOUTHEAST WEST VIRGINIA OVERNIGHT AND IN THE VIRGINIA PIEDMONT EARLY WEDNESDAY MORNING. THE NEXT COLD FRONT OVER THE OHIO VALLEY WILL APPROACH THE FORECAST AREA AFTER MIDNIGHT. MODELS HAVE ONLY A LOW CHANCE OF PRECIPITATION WITH THIS FRONT. HAVE ALIGNED THE HIGHER PROBABILITY OF PRECIPITATION AHEAD OF THIS FRONT AND KEPT A LOW CHANCE IN THE PIEDMONT LATE TONIGHT. THE BROAD TROUGH ACROSS EAST COAST WILL SHIFT SLIGHTLY EASTWARD AS THE UPPER RIDGING BUILDS. IT WILL REMAIN WARM AND HUMID OVERNIGHT WITH LOW TEMPERATURES FROM THE MID 50S IN THE MOUNTAINS TO THE MID 60S IN THE SOUTHEAST. KEPT THE LIGHT POPS IN FOR WEDNESDAY WITH BEST CHANCES ACROSS THE SOUTH. PLAYED HIGHS WEDNESDAY CLOSER TO COOLER MOS VALUES FROM THE UPPER 60S IN THE WESTERN MOUNTAINS TO THE LOWER 80S IN THE PIEDMONT. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... AS OF 345 PM EDT TUESDAY... SUBSIDENCE AND DRYING ALOFT INCREASES FOR THE LATER HALF OF THE WEEK AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH WEDNESDAY NIGHT AND THURSDAY...WITH A BROAD EASTERLY COMPONENT TO THE WIND AS THE HIGH DRIFTS TO ALONG THE COAST LATE THURSDAY INTO FRIDAY. WITH HEIGHTS BUILDING ALOFT...AND A DRY MID LEVEL EASTERLY WIND...LOOKING AT MAINLY TRANQUIL WEATHER WITH LITTLE OR NO PRECIP THREAT. TEMPERATURES WILL BE NEAR SEASONAL...NOT TOO HOT...NOT TOO COOL. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 345 PM EDT TUESDAY... MODERATING TEMPERATURES EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK AS THE UPPER LEVEL RIDGE CONTINUES TO BUILD...850 TEMPS CREEPING TOWARD +2OC FOR MONDAY AND TUESDAY. THIS SUGGESTS SURFACE TEMPS WILL TOP OUT MAINLY IN THE 80SF...TESTING 90F DEGREES FOR THE URBAN AREAS. NO REAL FOCUS FOR DEEP CONVECTION DURING THE PERIOD EXCEPT FOR CONVERGENCE OVER THE MTNS...SO KEPT ANY PRECIP THREAT MAINLY DIURNAL AND PRIMARILY TARGETED TO THE MTNS. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... AS OF 1240 AM EDT WEDNESDAY... DEEPER MOISTURE HAS EXITED THE AREA TONIGHT AHEAD OF A WEAK SECONDARY COLD FRONT JUST NORTH OF REGION THAT WILL DRIFT SOUTH OVERNIGHT. FEW REMAINING SHRA AHEAD OF THE BOUNDARY LIKELY TO FADE UPON APPROACH FROM THE NORTH SO EXPECTING OVERALL LACK OF PRECIP THROUGH DAYBREAK. HOWEVER FLYING CONDITIONS IN THE WAKE OF THE HEAVIER RAINFALL FROM TUESDAY WILL DETERIORATE OVERNIGHT AS AREAS OF FOG/STRATUS DEVELOP IN THE VALLEYS AND OUT EAST ESPCLY AROUND KDAN. THIS SHOULD RESULT IN AREAS OF IFR/LIFR CIGS AND VSBYS IN FOG WITH KROA ONLY SEEING A PERIOD OF MVFR LATE. EXPECT LOW CONDITIONS TO GRADUALLY IMPROVE TO VFR WITH HEATING WED MORNING BEFORE THE FLOW SLOWLY TURNS MORE SE ALLOWING BKN 4-6K FT CU CIGS TO REDEVELOP ESPCLY ALONG THE BLUE RIDGE. EASTERN LOCATIONS SUCH AS KLYH/KDAN MAY SEE LOW CIGS/VSBYS HANG ON LONGER UNDER LIGHT NE FLOW. LATEST MODELS THEN SUGGEST SOME LATE DAY SHRA/TSRA POTENTIAL MAINLY KROA/KBCB SO INCLUDING A VCTS THERE. OTRW LEAVING OUT PRECIP MENTION GIVEN ISOLATED NATURE ELSW. LEFTOVER CLOUDS AND WIDELY SCATTERED CONVECTION MAY LINGER INTO WEDNESDAY NIGHT ALONG THE BLUE RIDGE CORRIDOR WITH MOST OF THIS COVERAGE LIKELY ENDING UP SOUTH OF THE TERMINALS BEFORE ENDING LATER WED NIGHT. ADDED FOG THEN LIKELY AFTER MIDNIGHT...MOSTLY BEYOND THE END OF THE VALID TAF PERIOD SO WONT INCLUDE MENTION. FOR THURSDAY INTO THE WEEKEND...CONTINUED DIURNAL CONVECTION...ESPECIALLY ALONG THE APPALACHIANS...WITH LOCALLY BRIEF MVFR-IFR CIGS/VSBYS IN TSRA. AREAS OF MVFR-IFR VSBYS BR...LOCALLY IFR FG...ALSO POSSIBLE DURING THE MORNING HOURS. OTRW OVERALL VFR DURING THE DAYTIME HOURS BEFORE/AFTER ANY RIDGE ORIENTED CONVECTION DEVELOPS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH NEAR TERM...AMS/KK SHORT TERM...PM LONG TERM...PM AVIATION...JC/JH/KK
AREA FORECAST DISCUSSION...UPDATED
NWS SPOKANE WA
612 PM PDT Thu Jun 20 2013 .SYNOPSIS... Rain will continue tonight and early Friday but will decrease in intensity and gradually subside by Friday evening. A drying and warming trend is expected Saturday and early Sunday with the exception of isolated mountain thunderstorms. More wet and cool weather will arrive as early as Sunday afternoon and persist through midweek followed by another warming, dry period to close out the work-week. && .UPDATE... Did an update to increase chance of precipitation most locations early this evening and then again overnight. Closed low currently resides over southern Alberta and will retrograde west back toward eastern WA and northern ID. HRRR model is hinting at some wrap around precipitation currently over southeastern British Columbia moving southwest through the evening and into the eastern Cascades overnight. Also the area of rain currently over the basin will slowly shift north and east through the evening and overnight hours into extreme eastern WA and north ID. So, overall a very wet, soggy night. Summer solstice is at 1004 tonight, and it feels like April. /Nisbet && .AVIATION... 00Z TAFS: The rain band over Spokane, Coeur D`Alene, Sandpoint and Moses Lake should become less organized tonight through tomorrow morning as the upper support shears over the next 18 to 24 hours. Low level flow is expected to decrease and the loss of low level mixing should promote stratus development through the early morning hours. Ceilings at or below 1000 feet at Spokane, Pullman, and Coeur D`Alene seems like a good bet. Summer solstice means the most daylight of the year, so it will be interesting to see how long we can keep stratus. The air mass will be very moist tomorrow, but the high sun angle should eventually break up the low cloud deck. /GKoch && .PRELIMINARY POINT TEMPS/POPS... Spokane 46 59 46 70 50 75 / 100 70 20 10 0 20 Coeur d`Alene 44 59 45 69 48 75 / 100 70 40 20 10 20 Pullman 44 59 43 69 47 74 / 70 60 50 10 10 20 Lewiston 48 65 50 76 54 81 / 50 60 40 10 0 20 Colville 46 64 45 73 47 79 / 90 50 20 20 10 20 Sandpoint 46 60 46 67 45 74 / 100 70 50 30 30 20 Kellogg 45 57 44 65 47 72 / 100 70 60 30 30 20 Moses Lake 50 71 49 79 55 81 / 100 30 10 0 0 20 Wenatchee 51 71 52 78 59 80 / 100 20 10 0 0 20 Omak 48 71 49 77 52 80 / 80 20 10 10 0 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1024 PM PDT Tue Jun 18 2013 .SYNOPSIS... A band of moderate rain will develop over the Idaho Panhandle and extreme eastern Washington and continue on Wednesday. More rain is expected on Thursday, mainly across the northern and eastern mountains. The rain will gradually subside on Friday with a drying and warming trend expected this weekend. Wetter and cooler weather will return early next week. && .DISCUSSION... Radar is starting to show the north-south orientation to the precip, with a band extending along the Oregon/Idaho border north of Ontario up to Lewiston. 04Z RAP run has this fairly well depicted, along with the small area of rain south of Spokane. The RAP expects this area of rain to fall apart, which agrees with latest radar trends. Then the north-south band of rain should move into the southern panhandle and reach the BC border by about sunrise Wednesday. Models continue to show a done-deal for moderate rain in the panhandle including Coeur d`Alene, but more iffy to the west (e.g. Spokane airport). I have backed off a smidge on the rainfall amounts a bit from the previous forecast as the new GFS agrees somewhat with the new NAM. I also removed any mention of thunder from Wednesday`s forecast. While there is an outside chance of a strike or 2 away from the main band of rain, it`s just not worth keeping in the forecast, as models don`t show any surface-based instability due to the extensive cloud cover and the cold pool staying to our south. RJ && .AVIATION... 06Z TAFS: A band of moderate rain will develop over the Idaho Panhandle tonight and persist through much of Wednesday. This will bring MVFR/IFR conditions to most of the TAFs (aside from KEAT and KMWH). KCOE will likely be IFR all day long. KSFF will also see some near-IFR conditions. Tougher call at KGEG which will be on the western edge of the rain band. KPUW will likely have an IFR cig in the morning but improve a bit in the afternoon. To the west, KMWH and KEAT will just have VFR clouds. Gusty west winds will develop in the late afternoon at KEAT in response to a strong pressure gradient. RJ && .PRELIMINARY POINT TEMPS/POPS... Spokane 51 54 45 55 44 61 / 100 100 80 80 50 60 Coeur d`Alene 52 54 46 54 42 60 / 100 100 100 90 50 60 Pullman 49 53 44 56 42 60 / 100 100 70 60 30 60 Lewiston 56 58 49 64 44 67 / 100 100 70 60 20 50 Colville 54 63 50 57 48 67 / 60 100 100 100 60 50 Sandpoint 54 56 46 53 45 60 / 100 100 100 100 60 60 Kellogg 50 51 44 51 39 57 / 100 100 100 100 50 60 Moses Lake 54 66 51 65 49 69 / 20 40 50 60 30 30 Wenatchee 52 66 52 64 51 68 / 30 40 50 60 40 30 Omak 54 66 51 64 50 69 / 20 70 70 80 60 50 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
954 PM CDT THU JUN 20 2013 .UPDATE... THE NEW 00Z NAM APPEARS TO INITIALIZE THE EASTERN NORTH DAKOTA/WESTERN MINNESOTA THUNDERSTORMS A LITTLE TOO FAR SOUTH. THE NAM TAKES THIS INTO NORTHWEST SECTIONS OF SOUTH CENTRAL WISCONSIN BY SUNRISE. THE 00Z HRRR IS BETTER TAKING THIS MCS EASTWARD INTO NORTHWEST WISCONSIN. HOWEVER IT ALSO DEVELOPS SOME THUNDERSTORMS ACROSS SOUTHWEST MINNESOTA BY 10 PM THIS EVENING. THIS APPEARS TOO QUICK CUT THE CIMMS CLOUD TOP COOLING IMAGE IS INDICATING -11 CELSIUS/15 MINS OVER FAR EASTERN SOUTH DAKOTA. THE HRRR BRINGS THIS INTO AREAS WEST OF MADISON AROUND 6 AM BUT IS RATHER WEAK AS THE 850 MB WIND MAX STAYS WEST OF THE MISSISSIPPI VALLEY. && .AVIATION/06Z TAFS/... EXPECT VFR CONDITIONS TONIGHT WITH SOME MID LEVEL ACCAS POSSIBLE DURING THE EARLY MORNING. SOME POTENTIAL OF A WEAKENING AREA OF THUNDERSTORMS APPROACHING SOUTH CENTRAL WISCONSIN BY SUNRISE. LOW LEVEL MOISTURE WILL INCREASE FRIDAY...AND SO WILL THE CHANCE OF THUNDERSTORMS. && .PREV DISCUSSION... /ISSUED 344 PM CDT THU JUN 20 2013/ VERY SHORT TERM...TONIGHT AND FRIDAY. TONIGHT - CONFIDENCE...MEDIUM MAIN FORECAST CONCERN IS THE TIMING OF ANY CONVECTION INTO THE AREA. LOW LEVEL MOISTURE GRADUALLY INCREASING FROM THE SOUTH PER ISODROSOTHERM ANALYSIS. MAIN CONVECTIVE FOCUS TO THE NORTH AND WEST CLOSER TO THE COLLOCATION OF UPPER JET/SHORTWAVE ACTIVITY AND LOW LEVEL MOISTURE FEED. NAM/GFS/GEM/00Z ECMWF ALL KEEP CWA MOSTLY DRY THROUGH THE NIGHT WITH ACTIVITY HOLDING OFF TO OUR WEST THROUGH 12Z. THE 12Z 4KM WRF DOES SUGGEST A WELL DEVELOPED LINE OF STORMS TRUDGING THROUGH MN AND BOWING OUT INTO PORTIONS OF WC WI BEFORE LOSING SOME STEAM IN OUR CWA. THE LATTER SCENARIO WOULD WARRANT FAIRLY ROBUST POPS FOR LATER IN THE NIGHT. WILL THUS KEEP HIGHEST POPS IN THE WESTERN CWA LATER TONIGHT WITH VERY SMALL POPS IN THE EAST. A MILDER NIGHT IN THE WORKS WITH THE SOUTH WINDS AND INCREASING DEW POINTS. FRIDAY - CONFIDENCE...MEDIUM VERY WARM AND MOIST FEED CONTINUES INTO SRN WI. CASE CAN BE MADE FOR WEAKENING CONVECTION/CLOUDS EARLY IN THE DAY WITH RECOVERY AND SOME RELOADING FOR THE AFTERNOON. 925 TEMPS RISE TO THE LOW 20S WHILE 850 TEMPS REACH 18-20C. LOW LEVEL JET ORIENTATION NOT THE BEST WITH ONE CORE LIFTING NORTHEAST AND THE OTHER ALIGNED MORE INTO NE IA/SE MN AND WC WI. ON THE POSITIVE SIDE FOR CONVECTION MODELS DO SHOW A 500 MILLIBAR SHORTWAVE SWINGING THROUGH IN THE AFTERNOON. EVEN THOUGH 850 JET PLACEMENT NOT THE BEST THERE IS STILL STEADY WAA WITH CAPES EXPECTED TO REACH OVER 1000 J/KG. SHORT TERM...FRIDAY NIGHT THROUGH SUNDAY. 500 MB SHORT WAVES TRACKING WITH UPPER LEVEL DIVERGENCE IN ENTRANCE REGIONS OF UPPER LEVEL SPEED MAXES MOVING THROUGH BASE OF NEARLY-STATIONARY UPPER LOW OVER THE CANADIAN PRAIRIE PROVINCES. FOR THE MOST PART THESE SHORT WAVES WILL STAY TO THE NORTH AND WEST OF THE CWA THROUGH SUNDAY EVENING. GRADUALLY INCREASING AND PERSISTENT 850-700 MB WARM AIR/MOISTURE ADVECTION OVER THE FORECAST AREA THROUGH THE PERIOD...THOUGH BEST FOCUS OF LOW-LEVEL JET STAYS TO THE WEST AND NORTHWEST AS MODELS CONTINUE TO SHOW THE JET STRENGTHENING WITH EACH WAVE...THEN VEERING TO THE EAST AND WEAKENING WITH PASSAGE OF EACH WAVE. CWASP FORECASTS SHOW >60 PCT PROBABILITIES STAYING TO OUR WEST AND NORTH...IN LINE WITH LAYER Q-VECTOR CONVERGENCE AND FRONTOGENESIS MAXES. OUR BEST OPPORTUNITIES FOR PRECIPITATION WILL BE WITH ANY MCS/S THAT FORM AND MOVE WITH VEERING 850 MB FLOW AND ALONG 1000-500MB THICKNESS GRADIENT. BEST CHANCE LOOKS TO BE FRIDAY NIGHT INTO SATURDAY AS 850 MB JET POINTS INTO WEST CENTRAL WI AND THEN INTO SRN WI AS IT WEAKENS. STEEP MID TO UPPER LEVEL LAPSE RATES PRODUCING ELEVATED CAPE OF 1000-1200 J/KG...WITH HAIL CAPE AROUND 400 J/KG SO POTENTIAL FOR HAIL AND GUSTY WINDS JUSTIFY THE SPC SLIGHT RISK OVER THE FORECAST AREA. LINGERING DEBRIS CLOUDS AND STRENGTH OF CAP WILL DETERMINE POTENTIAL FOR THUNDERSTORMS SATURDAY. PLENTY OF POTENTIAL INSTABILITY WITH EXPECTED HIGHS IN THE UPPER 80S AND DEW POINTS AROUND 70...BUT WILL LEAVE POPS IN CHANCE CATEGORY WITH FAIRLY STOUT CAPPING ON GFS AND TO A LESSER EXTENT THE ECMWF. 12Z NAM DEPICTS THE SAME SCENARIO FROM FRIDAY NIGHT FOR SATURDAY NIGHT AS WELL...BUT OTHER MODELS BACK THE STRONGER FLOW TO THE WEST OVER IOWA AND MINNESOTA SO WILL HOLD BETTER CHANCE POPS TO THE NW CWA FOR SATURDAY NIGHT AND SUNDAY. THE WARM AND HUMID CONDITIONS WILL RAISE HEAT INDEX VALUES TO BETWEEN 90 AND 95 FOR SATURDAY AND SUNDAY. LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. REGION REMAINS VERY SUMMER-LIKE WITH WEST-SOUTHWEST UPPER FLOW AS CANADIAN UPPER LOW BREAKS DOWN...WITH 850 MB TEMPERATURES IN THE UPPER TEENS TO LOWER 20S CELSIUS. THUNDERSTORM CHANCES REMAIN FOR EACH DAY BUT MAINLY DUE TO DIFFICULTY TO DISCERN EXACT TIMING OF SHORT WAVES/MCVS MOVING THROUGH NEAR ZONAL FLOW. ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD. AVIATION/00Z TAFS/...VFR CONDITIONS EXPECTED THROUGH THE PERIOD. LATE NIGHT THUNDERSTORM COMPLEX MAY ROLL IN FROM THE NORTHWEST. EXPECTED TO WEAKEN SOME UPON ARRIVAL INTO SC WI. WITH PERSISTENT WAA AND 500 MILLIBAR SHORTWAVE EXPECT MORE THUNDERSTORM DEVELOPMENT TO OCCUR AFTER ANY REMNANT PRECIP/CLOUDS MOVE OUT AND ALLOW FOR RENEWED DESTABILIZATION. FOR TAF PURPOSES KEEPING CEILINGS/VSBYS IN VFR CATEGORY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...HENTZ TONIGHT/FRIDAY AND AVIATION/MARINE...COLLAR FRIDAY NIGHT THROUGH THURSDAY...REM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
624 PM CDT THU JUN 20 2013 .SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 316 PM CDT THU JUN 20 2013 MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES AND POTENTIAL SEVERE WITH THUNDERSTORMS THROUGH PERIOD. LATEST WATER VAPOR SATELLITE IMAGERY SHOWING WEAK SHORTWAVE TROUGH LIFTING NORTHEAST INTO NORTH CENTRAL WISCONSIN AND A SERIES OF SHORTWAVE TROUGHS OVER LAKE SUPERIOR WESTWARD TO NORTH DAKOTA. LATEST MOSAIC RADAR INDICATES SHOWERS AND THUNDERSTORMS ACROSS NORTHERN WISCONSIN INTO EASTERN NORTH DAKOTA. THIS IS IN RESPONSE TO 925-850MB MOISTURE TRANSPORT AND NOSE OF LOW LEVEL JET PER 20.15Z RAP. THE 20.12Z GFS/NAM CONTINUE TO BE IN GOOD AGREEMENT IN CARVING UPPER LEVEL TROUGH OVER THE WESTERN UNITED STATES AND EJECTING OUT A SERIES OF SHORTWAVE TROUGHS EMBEDDED IN SOUTHWESTERLY FLOW ALOFT INTO THE NORTHERN PLAINS AND UPPER GREAT LAKES REGION OVER THE NEXT SEVERAL DAYS. BIGGEST DIFFERENCES REMAIN ARE THE TIMING AND PLACEMENT OF THE SHORTWAVE TROUGHS OVER THE UPPER GREAT LAKES REGION THROUGH THE PERIOD. THE DETERMINISTIC MODELS ARE OKAY IN AGREEMENT WITH SURFACE FRONT PLACEMENT THROUGH 12Z SATURDAY...THEN THE 20.12Z NAM PUSHES SURFACE FRONT FARTHER SOUTH THAN THE GFS. CONFIDENCE IN FORECAST BEGINS TO LOWER AFTER 12Z SATURDAY. TONIGHT INTO FRIDAY...THE 20.12Z GFS/NAM AND 20.15Z RAP ALL INDICATING DECENT 925-850MB MOISTURE TRANSPORT AND LOW LEVEL JET TO INCREASE THIS EVENING OVER FORECAST AREA. WITH A SERIES OF SHORTWAVE TROUGHS OVER THE NORTHERN PLAINS...HIGH RESOLUTION MODELS OF THE 20.12Z SPC WRF...20.12Z ARW-EAST AND 20.16Z HRRR SHOW A COMPLEX OF THUNDERSTORMS OVER EASTERN NORTH DAKOTA AND NORTHERN SOUTH DAKOTA ON THE NOSE OF THE LOW LEVEL JET/925-850MB MOISTURE TRANSPORT...TO MOVE EAST-SOUTHEAST INTO THE NORTHERN PORTIONS OF THE FORECAST AREA AROUND 09Z TO 12Z. THE 20.12Z GFS/NAM INDICATE SOME SORT OF COMPLEX OF THUNDERSTORMS TO TRACK INTO THE NORTHERN PORTIONS OF THE FORECAST AREA. CONFIDENCE IS INCREASING A COMPLEX OF THUNDERSTORMS WILL MOVE INTO THE NORTHERN PORTIONS OF THE FORECAST AREA. SEVERE POTENTIAL STILL EXIST WITH THE 20.12Z GFS/NAM SHOW 0-3KM SHEAR OF 25-35 KNOTS AND 0-6KM MOST UNSTABLE CAPE OF 1000-2000 J/KG OVER NORTHERN PORTIONS OF FORECAST AREA 06Z-12Z FRIDAY. THE COMPLEX OF STORMS SHOULD DEVELOP INTO A LINE/SQUALL LINE OF STORMS OVERNIGHT AND HAVE THE POTENTIAL FOR DAMAGING WINDS ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA. FRIDAY NIGHT INTO SUNDAY...ACTIVE WEATHER PATTERN CONTINUES...AS THE 20.12Z GFS/NAM CONTINUE TO INDICATE A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE UPPER MIDWEST AND UPPER GREAT LAKES REGION. THE 20.12Z GFS/NAM CONTINUE TO HAVE DIFFERENCES IN TIMING AND PLACEMENT OF THE SHORTWAVE TROUGHS/SURFACE FRONT ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION. THE DETERMINISTIC MODELS DO SHOW 20 TO 30 KNOTS OF 0-3KM WIND SHEAR AND ELEVATED CAPE OF A 2000- 3000 J/KG FRIDAY THROUGH 06Z SATURDAY. POTENTIAL IS THERE FOR THUNDERSTORMS TO BECOME SEVERE WITH THE MAIN THREAT TO BE DAMAGING WINDS. HOWEVER...THE DETERMINISTIC MODELS ARE FOCUSING THE BEST CHANCES FOR CONVECTION TO AFFECT MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH SUNDAY...WITH THE 20.12Z GFS SUGGESTING MUCH OF THE CONVECTION TO BE NORTH AND NORTHWEST OF THE FORECAST AREA. CONFIDENCE IN FORECAST REMAINS LOW FRIDAY NIGHT INTO SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 316 PM CDT THU JUN 20 2013 MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THROUGH THE PERIOD. THE 20.12Z GFS/NAM/GEM ARE IN AGREEMENT IN EJECTING OUT A COUPLE OF SHORTWAVE TROUGHS INTO THE UPPER MIDWEST THROUGH 00Z WEDNESDAY...THEN MODELS BEGIN TO DIG UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION AND DEVELOP NORTHWEST FLOW ALOFT OVER FORECAST AREA WEDNESDAY INTO THURSDAY. WITH ENOUGH LIFT AND MOISTURE IN ASSOCIATION WITH SHORTWAVE TROUGHS WILL CONTINUE WITH SMALL CHANCES OF PRECIPITATION THROUGH MUCH OF THE PERIOD. TEMPERATURES THROUGH 12Z WEDNESDAY WILL BE ABOVE NORMAL...AS THE DETERMINISTIC MODELS ADVECT WARMER AIR ALOFT INTO FORECAST AREA MONDAY INTO TUESDAY. THE 20.12Z GFS/ECMWF ARE SHOWING 925MB TEMPERATURES PLUS 24 TO 27 DEGREES CELSIUS BY 00Z WEDNESDAY AND THE 20.00Z GEFS INDICATE STANDARDIZED ANOMALIES OF 1-1.5 ABOVE NORMAL. THIS WILL ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 80S TO POSSIBLY INTO THE MIDDLE 90S ACROSS FORECAST AREA. COOLER AIR WILL FILTER INTO THE FORECAST BEHIND SURFACE LOW/SHORTWAVE TROUGH WEDNESDAY INTO THURSDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 624 PM CDT THU JUN 20 2013 THE FOCUS FOR THIS SET OF TAFS WILL BE THE COMPLEX OF STORMS OVER NORTH DAKOTA AND WHAT THEY DO THROUGH THE NIGHT. IT APPEARS THE MESO MODELS HAVE THE BEST HANDLE ON THIS ACTIVITY AND THESE ALL INDICATE THE COMPLEX FORMING INTO A BOWING SEGMENT LINE AND EVENTUALLY TURNING SOUTHEAST AND COMING DOWN THE MISSISSIPPI RIVER VALLEY DURING THE OVERNIGHT HOURS. THE HI-RES ARW AND NMM BOTH SHOW THE COMPLEX TO BE IN A WEAKENING STAGE IS IT COMES IN WHICH MAKES SENSE WITH THE 21.18Z NAM AND 21.21Z RAP SUGGESTING THE STORMS WILL OUT RUN THE BEST 0-3KM SHEAR ONCE THEY CROSS THE SURFACE BOUNDARY CURRENTLY ACROSS CENTRAL MINNESOTA AND NORTHERN WISCONSIN. WILL CONTINUE TO SHOW THE STORMS COMING INTO THE TAF SITES AROUND 08Z-09Z WITH A WIND GUST POTENTIAL TO 30 KNOTS WITH THE INITIAL LINE OF STORMS AND A COUPLE HOURS OF GENERAL THUNDER ACTIVITY UNTIL IT MOVES SOUTH SHORTLY AFTER 21.12Z. THE STORMS SHOULD BE ABLE TO REDUCE THE VISIBILITY IN THE RAIN WITH MVFR CONDITIONS POSSIBLE. ONCE THIS MOVES THROUGH...THE REST OF THE DAY LOOKS TO BE DRY WITH VFR CONDITIONS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM....DTJ AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
356 PM MDT WED JUN 19 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 230 PM MDT WED JUN 19 2013 FORECAST CHALLENGES THROUGH THE SHORT TERM DEAL WITH WINDS THROUGH FRIDAY. CURRENTLY...SOUTHWEST WINDS PRETTY STRONG OUT WEST OF THE LARAMIE RANGE THIS AFTERNOON. GETTING WIND GUSTS OVER 40 MPH IN CARBON COUNTY...EXTENDING TO THE WEST SLOPES OF THE LARAMIE RANGE. VERY DRY OUT THAT WAY...RAWLINS REPORTING 6 PERCENT HUMIDITY AT 1 PM THIS AFTERNOON...LARAMIE 9 PERCENT. LATEST SPC MESONALYSIS SHOWING A CAP STILL IN PLACE OUT IN THE PANHANDLE...WITH CONVECTIVE INHIBITION OF -25 TO -50 J/KG. VISIBLE IMAGERY SHOWING PRETTY MUCH CLEAR SKIES...WITH NO CU DEVELOPMENT ALL ALONG THE FRONT RANGE. THERE IS A SMALL WINDOW LATE THIS AFTERNOON WHERE THE SOUTHERN PANHANDLE SEES A BREAK IN THE CAP. WITH 700MB TEMPERATURES CLIMBING TO +16C...CONFIDENCE IS NOT HIGH THAT THE CAP WILL BE BROKEN. LATEST HRRR FORECAST DOES SHOW A FEW CELLS DEVELOPING ACROSS GOSHEN COUNTY AND THE NORTHERN PANHANDLE AFTER 00Z...SO WILL KEEP THE SLIGHT CHANCE POPS INHERITED GOING FOR A COUPLE HOURS THROUGH THE 03Z TIME FRAME. WINDS EASE THIS EVENING WITH THE GFS 700MB WINDS DECREASING TO 15-20KTS AFTER 06Z. FOR THURSDAY...WINDS TO REMAIN FAIRLY LIGHT OUT WEST THROUGH THE MORNING AND MID AFTERNOON. THEY DO START PICKING UP AFTER 00Z...INCREASING TO 25 TO 30KTS BY 06Z. LOOKS LIKE A PRETTY WINDY DAY ONCE AGAIN OUT WEST OF THE LARAMIE RANGE. FRIDAY WE START TO SEE A CHANGE AS THE UPPER LOW OVER WESTERN MONTANA OPENS UP AND A FAIRLY STRONG SHORTWAVE TRACKS INTO WESTERN WYOMING. 700MB WINDS OUT WEST TO REMAIN 25 TO 35 KTS...BUT WINDS OVER THE PANHANDLE TURN MORE EASTERLY AS THE LEE SIDE TROUGH DEEPENS. DEPENDING ON WHICH MODEL YOU LOOK AT...WE COULD SEE SHOWERS AND THUNDERSTORMS DEVELOPING OUT THAT WAY FRIDAY AFTERNOON. THE NEW ECMWF PAINTING A WIDESPREAD AREA OF QPF OVER THE NORTHERN PANHANDLE FRIDAY AFTERNOON AND EVENING. GFS IS DRY AND LATEST NAM/WRF SIMILAR TO THE ECMWF...THOUGH NOT AS WIDESPREAD ON PRECIP. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 345 PM MDT WED JUN 19 2013 PESKY PACIFIC NORTHWEST LOW PRESSURE WILL FINALLY BEGIN TO FILL THIS WEEKEND AS IT EJECTS INTO THE NRN PLAINS. AN ASSOCIATED SHORTWAVE WILL TRAVERSE THRU WYOMING ON SATURDAY. MEDIUM RANGE GUIDANCE VARIES SIGNIFICANTLY ON THE AMOUNT OF AVAILABLE LLVL MOISTURE ACROSS THE AREA ON SATURDAY. THE GFS IS SIGNIFICANTLY DRIER FOR MUCH OF THE CWA AS MUCH OF THE MOISTURE IS SHUNTED MOISTURE ACROSS EASTERN ZONES. MEANWHILE...THE ECMWF IS DEEPER AND FURTHER WEST WITH THE MOISTURE...WHICH WOULD BACK UP CONVECTION INTO THE EASTERN SOUTHEAST WYOMING PLAINS. FOR NOW HAVE KEPT AFTERNOON SHOWER AND THUNDERSTORM CHANCES GOING FOR MUCH OF THE EASTERN PLAINS. INSTABILITY PARAMETERS WOULD CERTAINLY BE SUPPORTIVE OF SEVERE WEATHER POTENTIAL IF THE LLVL MOISTURE MATERIALIZES. THIS WILL BE ESPECIALLY TRUE ACROSS THE WESTERN NEBRASKA PANHANDLE SATURDAY AFTERNOON AND EARLY EVENING. LLVL MOISTURE MAY HANG AROUND AGAIN ON SUNDAY AFTERNOON...AS PROGD INSTABILITIES REMAIN ELEVATED OUT ON THE EASTERN PLAINS. MAIN QUESTION WILL BE WHETHER OR NOT THERE WILL BE A FOCAL POINT TO PROVIDE LIFT. HOWEVER...RECENT MODEL GUIDANCE DOES SHOW AT THE ANOTHER WEAK SHORTWAVE PERHAPS LATE SUNDAY. FOR NOW HAVE ADDED SHOWER AND THUNDERSTORM CHANCES ALONG AND EAST OF THE LARAMIE RANGE DURING THE AFTERNOON...SPREADING INTO THE WESTERN NEBRASKA PANHANDLE BY EARLY EVENING. FLOW TURNS DRIER AND MORE SOUTHWESTERLY FOR MONDAY THROUGH WEDNESDAY. SO HAVE THE FIRST HALF OF NEXT WEEK DRY FOR NOW. FIRE WEATHER CONCERNS WILL BE HEIGHTENED GIVEN THIS TRANSITION TO DRY CONDITIONS. PROGD H7 TEMPERATURES WILL HOVER BETWEEN 13-15C THRU MUCH OF THE PERIOD...WHICH WILL YIELD AFTERNOON HIGHS GENERALLY IN THE 80S ACROSS SOUTHEAST WYOMING WITH 80S AND LOW/MID 90S ACROSS THE WESTERN NEBRASKA PANHANDLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING) ISSUED AT 140 PM MDT WED JUN 19 2013 A WEAK DISTURBANCE WILL MOVE THROUGH THE REGION TODAY. A FEW ISOLATED -SHRA/-TSRA MAY DEVELOP IN THE VICINITY OF KCDR BETWEEN 22Z AND 02Z. ALL OTHER TERMINALS ARE EXPECTED TO REMAIN DRY. WINDY CONDITIONS WILL PREVAIL AT MOST SITES TODAY...WITH SOUTHEAST WINDS GUSTING TO 30 KTS AT THE PANHANDLE SITES AND SOUTHWEST WINDS GUSTING AS HIGH AS 40 KTS WEST OF THE LARAMIE RANGE. WINDS WILL EASE AND TURN TO THE WEST-NORTHWEST TONIGHT. && .FIRE WEATHER... ISSUED AT 230 PM PM MDT WED JUN 19 2013 SOUTHWEST WINDS OF 20 TO 30 MPH SUSTAINED WITH GUSTS TO 40 MPH WILL CONTINUE THIS AFTERNOON WEST OF THE LARAMIE RANGE. AFTERNOON HUMIDITIES HAVE ALREADY FALLEN INTO THE SINGLE DIGITS. WINDS ARE EXPECTED TO EASE BY MID EVENING. POOR HUMIDITY RECOVERIES EXPECTED OVERNIGHT WEST OF THE LARAMIE RANGE WITH GOOD RECOVERIES IN THE PANHANDLE. A DRY FORECAST THROUGH SATURDAY WITH WINDS INCREASING AGAIN FRIDAY AFTERNOON. THIS DUE TO A LOW PRESSURE SYSTEM TRACKING THROUGH MONTANA. THIS LOW WILL DRAG A COLD FRONT THROUGH THE AREA SATURDAY WITH SCATTERED CHANCES FOR SHOWERS AND THUNDERSTORMS IN THE PANHANDLE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...CLAYCOMB LONG TERM...HAHN AVIATION...HAHN FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS ALBANY NY
416 AM EDT FRI JUN 21 2013 .SYNOPSIS... HIGH PRESSURE WILL TAKE UP RESIDENCE JUST OFF THE EASTERN SEABOARD TODAY INTO THE WEEKEND. A SOUTHWESTERLY FLOW AROUND THIS HIGH PRESSURE AREA WILL RESULT IN WARMER TEMPERATURES AND RISING LEVELS OF HUMIDITY. ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE EACH DAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 415 AM EDT...AS HIGH PRESSURE SETTLES IN JUST OFF THE EASTERN SEABOARD TODAY...A RETURN WEST-SOUTHWEST FLOW ALOFT WILL DEVELOP AND ALLOW TEMPERATURES TO WARM MORE THAN PREVIOUS DAYS. NAM/GFS STILL SHOWING A SUBTLE LOW LEVEL CONVERGENCE ZONE SETTING UP FROM JUST SOUTH OF KALB TO NEAR KPOU...MAINLY SEEN ON SURFACE WIND FIELDS. INSPECTING HIGHER RESOLUTION MODELS...THE 4KM WRF- NMM...LOCAL HIRESWRF AND EVEN THE HRRR SHOWING A FEW CELLS POPPING UP IN THE GENERAL VICINITY OF THE CONVERGENCE ZONE THIS AFTERNOON. COVERAGE LOOKS TO BE ISOLATED AT BEST...WITH MOST OF THE AREA ESPECIALLY FROM ALBANY NORTHWARD REMAINING DRY. INSTABILITY LOOKS MEAGER...BUT GIVEN SLIGHTLY HIGHER DEWPOINTS AND TEMPS IN THE 80S...WILL MENTION POSSIBLE THUNDER. THERE MAY BE A FEW MORE CLOUDS AROUND THAN PRIOR DAYS...BUT SKIES SHOULD STILL AVERAGE MOSTLY-PARTLY SUNNY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... ANY ISOLATED CONVECTION WILL QUICKLY DIMINISH THIS EVENING WITH LOSS OF DAYTIME HEATING. TEMPERATURES WILL BE MILDER THAN THE PAST FEW NIGHT DUE TO CONTINUED WARMING ALOFT. THE WEEKEND WILL FEATURE SUMMER-LIKE WARMTH ALONG WITH THE CHANCE FOR SOME THUNDERSTORMS...WHICH WILL MAINLY BE DIURNALLY DRIVEN. THERE ARE SOME SUBTLETIES THAT WILL HAVE AN IMPACT ON COVERAGE/TIMING OF CONVECTION. ON SATURDAY...THE REGION WILL STILL BE UNDER THE INFLUENCE OF A W-NW FLOW ALOFT ON THE NORTHERN PERIPHERY OF A BUILDING UPPER LEVEL RIDGE OVER THE OHIO VALLEY AND MID ATLANTIC REGION. VARIOUS SOURCES OF GUIDANCE INDICATING A WEAK DISTURBANCE OR TWO EMBEDDED IN THE FLOW WILL PASS THROUGH MAINLY THE NORTHERN HALF OF THE AREA. THIS COULD BE ENOUGH FORCING TO TRIGGER SCATTERED CONVECTION GIVEN AN INCREASE IN LOW LEVEL DEWPOINTS AND PRECIPITABLE WATER NEARING OR EXCEEDING 1.5 INCHES. WILL MENTION CHANCE POPS ACROSS THE NORTHERN 2/3 OF THE AREA...WITH SLIGHT CHANCE SOUTH. SBCAPE GENERALLY FORECAST TO BE AROUND 500-1000 J/KG...WITH 850-500MB LAPSE RATES ONLY AROUND 5.5 TO 6.0 C/KM...SO T-STORMS ARE NOT EXPECTED TO BE SEVERE. DEPENDING ON EVENTUAL DEGREE OF CLOUD COVER SATURDAY AFTERNOON...TEMPERATURES COULD REACH THE MID 80S IN MOST VALLEY LOCATIONS. CONVECTION SHOULD DIMINISH DURING THE EVENING HOURS AS DAYTIME HEATING IS LOST AND THE UPPER LEVEL DISTURBANCES MOVE EAST OF THE REGION. SUNDAY MAY FEATURE ADDITIONAL MAINLY SCATTERED SHOWERS AND T-STORMS...WHICH SHOULD BE DIURNALLY DRIVEN AND POSSIBLY EVEN TIED TO TERRAIN/DIFFERENTIAL HEATING AREAS AS THE UPPER RIDGE BUILDS ACROSS THE AREA. THE NAM IS DEPICTING A FLATTER FLOW REGIME ALOFT...WHILE THE GFS/ECMWF TENDS TO BUILD THE UPPER RIDGE MORE. SINCE IT IS A COUPLE DAYS AWAY...THERE IS QUITE A BIT OF UNCERTAINTY AS TO THE DEGREE OF CONVECTION THAT EVOLVES. WILL MENTION LOW CHANCE POPS FOR MUCH OF THE AREA...WITH SLIGHT CHANCE SOUTH. WILL HAVE TO WATCH UPSTREAM OVER THE UPPER GREAT LAKES FOR ANY CONVECTIVE FOOTPRINTS THAT MAY EVENTUALLY IMPACT THE REGION...ESPECIALLY IF WE REMAIN ON THE NORTHERN PERIPHERY OF THE UPPER RIDGE. SUNDAY SHOULD BE THE WARMEST DAY SINCE JUNE 2ND ACROSS THE AREA AS ADDITIONAL WARMING ALOFT OCCURS WITH MID TO UPPER 80S EXPECTED FOR MUCH OF THE REGION. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FLAT BROAD UPPER RIDGING SHOULD SET UP OVER EASTERN NORTH AMERICA WITH SMALL PIECES OF UPPER LEVEL ENERGY TRACKING AROUND THE NORTHERN PERIPHERY OF THE RIDGE MONDAY THROUGH TUESDAY NIGHT. THESE LITTLE PIECES OF UPPER ENERGY SHOULD ENHANCE THE THREAT OF SHOWERS/TSTMS EACH AFTN/EVENING AND HAVE FORECAST 30 TO 40 PERCENT POPS EACH AFTN/EVENING...AND 20 TO 30 PERCENT POPS DURING THE OVERNIGHT AND MORNING HOURS. FOR SUNDAY NIGHT HAVE FORECAST DRY CONDITIONS. ALTHOUGH NOT AS IMPRESSIVE AS LAST NIGHT...THE GFS/ECMWF STILL SHOW A DEEPENING UPPER LEVEL TROF WILL MOVE INTO THE REGION BY WEDNESDAY AFTN WITH AN EVEN GREATER THREAT FOR SHOWERS/TSTMS WED AFTN THROUGH THURSDAY. FOR EACH AFTN/EVENING DURING THIS PERIOD HAVE FORECAST 40 TO 50 PERCENT POPS...AND 30 TO 40 PERCENT DURING THE OVERNIGHT AND EARLY MORNING HOURS. IT WILL BE VERY WARM OR HOT EARLY IN THE LONG TERM PERIOD...WITH A BIT OF A COOL DOWN WEDNESDAY AND THURSDAY AS THE UPPER LEVEL TROF MOVES INTO THE REGION. IT WILL BE HUMID DURING THE ENTIRE PERIOD WITH DEWPOINTS GENERALLY IN THE 60S. HIGHS MONDAY AND TUESDAY WILL BE IN THE 80S TO AROUND 90...THEN UPPER 70S AND 80S WEDNESDAY...AND MID 70S TO LOWER 80S THURSDAY. LOWS WILL GENERALLY BE IN THE UPPER 50S AND 60S SUNDAY NIGHT THROUGH WEDNESDAY NIGHT. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... ALTHOUGH NOT OCCURRING YET...HAVE INCLUDED TEMPO GROUPS FOR IFR FOG AT KGFL/KPSF SINCE CLEAR SKIES AND CALM WINDS WILL CONTINUE THROUGH AFTER SUNRISE. OTHER THAN THE POSSIBLE IFR AT KGFL/KPSF...EXPECT VFR CONDITIONS AT ALL THE TAF SITES (KALB/KPOU/KGFL/KPSF) THROUGH THE TAF PERIOD ENDING AT 06Z SATURDAY. WITH HIGH PRESSURE OVER THE REGION CONDITIONS WILL BE MAINLY P6SM SCT250 WITH A FEW CUMULUS CLOUDS THIS AFTERNOON. MAINLY OR LIGHT SOUTH WINDS THROUGH A FEW HOURS AFTER SUNRISE...THEN SOUTH TO SOUTHWEST WINDS AT LESS THAN 8 KTS DURING THE REST OF FRIDAY...THEN CALM WINDS AGAIN FRIDAY NIGHT. OUTLOOK... LATE FRI NITE...MAINLY VFR. NO SIG WX. SAT...MAINLY VFR. SLGT CHC -TSRA/-SHRA. SUN-TUE...MAINLY VFR. CHC -TSRA/-SHRA. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS CONTINUE DUE TO THE PAST SEVERAL WEEKS OF WET WEATHER. HIGH PRESSURE WILL MOVE OFF THE EAST COAST TODAY INTO THE WEEKEND. ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS ARE POSSIBLE FROM THIS AFTERNOON AFTERNOON THROUGH THE WEEKEND...ALONG WITH A GRADUAL WARMING TREND. DEW FORMATION SHOULD OCCUR EACH NIGHT WITH THE RISING LEVELS OF HUMIDITY. && .HYDROLOGY... FLOWS REMAIN ABOVE NORMAL ACROSS THE HYDRO SERVICE AREA. FROM TODAY INTO EARLY NEXT WEEK...THERE MAY ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS...BUT WIDESPREAD RAINFALL IS NOT ANTICIPATED AT THIS TIME...AND NOT ALL LOCATIONS WILL SEE RAINFALL. THUS...RIVER LEVELS ARE EXPECTED TO CONTINUE TO GRADUALLY RECEDE DURING THIS TIME. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...GJM AVIATION...GJM FIRE WEATHER...FRUGIS/JPV HYDROLOGY...FRUGIS/JPV
AREA FORECAST DISCUSSION
NWS MIAMI FL
251 AM EDT FRI JUN 21 2013 SHORT TERM (TODAY THROUGH SUNDAY)... NOT MUCH HAS CHANGED FROM EARLIER THINKING. DEEP LAYER RIDGE HAS BECOME ESTABLISHED ACROSS THE FLORIDA PENINSULA AND IT WILL SHIFT JUST SLIGHTLY NORTH TODAY AS A TROPICAL WAVE APPROACHES FROM THE BAHAMAS. DRIER ALOFT AHEAD OF THE WAVE WILL MOVE OVER SOUTH FLORIDA TODAY WITH PWAT DROPPING TO AROUND 1.5 INCHES.OR SLIGHTLY LESS AND THIS SEEN ON SATELLITE DERIVED TOTAL PWAT WITH GLOBAL MODELS ALSO IN GOOD AGREEMENT. THE HRRR IS SHOWING ONLY A FEW SHRA ALONG THE EAST COAST EARLY THIS MORNING AND THEN DEVELOPS CONVECTION FROM NEAR BELLE GLADES TO NAPLES AREA AND POINTS NORTH AFTER 18Z SO THIS ALL SEEMS REASONABLE. THE WAVE IS CURRENTLY LOCATED ACROSS THE EASTERN BAHAMAS AND EXTENDING SOUTH INTO THE CARIBBEAN THROUGH THE DOMINICAN REPUBLIC AND HAS LOST MUCH OF ITS CONVECTION. THE GLOBAL MODELS ARE NOT TOO TERRIBLY IMPRESSED WITH IT BUT DO INCREASE THE MOISTURE ACROSS SOUTH FLORIDA BY EARLY SATURDAY SO THERE SHOULD BE AN INCREASE IN SHOWER ACTIVITY OVER THE ATLANTIC OFF THE SOUTHEAST COAST LATE TONIGHT AND THEN THESE MOVING ONSHORE DURING THE DAY. THE WAVE WILL CONTINUE WESTWARD BY SUNDAY WITH DRIER AIR AGAIN MOVING IN ALOFT LATE IN THE WEEKEND FOR A DECREASE IN CONVECTION WITH THE GREATEST CONCENTRATION NEAR THE SOUTHWEST COAST. .LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)... A DEEP EASTERLY FLOW WILL BE ESTABLISHED ALL OF NEXT WEEK WITH FORECAST SOUNDINGS SHOWING PWAT AT AROUND 1.6-1.7 INCHES SO SLIGHTLY BELOW THE LATE JUNE AVERAGE WHICH IS ABOUT 1.75 INCHES. STEERING FLOW WILL BE SUCH THAT THE BEST CHANCES FOR RAINFALL WILL BE ALONG THE ATLANTIC COAST DURING THE LATE NIGHT AND EARLY MORNING SHIFTING TO THE INTERIOR AND GULF COAST DURING THE AFTERNOON AND EVENINGS. && .AVIATION... MODELS INDICATE A DRIER AND QUIETER WEATHER DAY TODAY. THE ONLY AREA HAS ANY PRECIPITATION REFLECTED IN THE TAFS AT THIS TIME IS KAPF, WITH A VCSH. EVEN SO, THERE IS A SLIGHT CHANCE OF A THUNDERSTORM ACROSS MOST OF SOUTH FLORIDA, WITH A SLIGHTLY HIGHER CHANCE OF ONE FOR KAPF. OTHERWISE, A PARTLY CLOUDY DAY, WITH SOUTHEASTERLY WINDS BETWEEN 10 AND 15 KTS. WINDS SHOULD BECOME MORE EASTERLY IN THE EVENING AND DROP TO 5 TO 10 KTS. && .MARINE... MARINE CONDITIONS WILL REMAIN BELOW ADVISORY CRITERIA BUT THERE COULD BE AN INCREASE IN THE SOUTHEAST WIND OVER THE WEEKEND TO 15 KNOTS OR A LITTLE HIGHER. BUT SEAS WILL GENERALLY BE 4 FEET OR LESS THROUGH THE PERIOD. && .FIRE WEATHER... NO PROBLEMS OR CONCERNS WITH AMPLE LOW LEVEL MOISTURE THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 78 87 77 / 20 20 40 30 FORT LAUDERDALE 87 78 87 78 / 20 20 40 30 MIAMI 89 78 88 77 / 20 20 40 30 NAPLES 92 73 93 74 / 30 20 40 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS POCATELLO ID
254 AM MDT FRI JUN 21 2013 .DISCUSSION...UPPER LOW CONTINUES TO SPIN OVER WESTERN MONTANA AND THE IDAHO PANHANDLE THIS MORNING AND IS SEEN SPINNING UP A COUPLE OF VORT LOBES THAT WILL MOVE THROUGH TODAY AND TONIGHT. THE FIRST IS CURRENTLY PRODUCING SHOWERS OVER SOUTHWEST IDAHO. HRRR PROJECTS THIS WAVE OF ENERGY TO MOVE THROUGH THE SNAKE PLAIN THIS MORNING AND IN THE UPPER SNAKE HIGHLANDS AROUND NOON. NOT EXPECTING MUCH TO REACH THE GROUND...BUT HAVE INCLUDED SLIGHT CHANCE POPS OVER THE SOUTHERN HIGHLANDS THIS MORNING. THE SECOND LOBE WILL SWING AROUND ON SATURDAY MORNING IMPACTING MAINLY THE CENTRAL IDAHO MOUNTAINS...BUT THE SNAKE PLAIN MAY SEE INCREASED WINDS AS THE TROUGH SWINGS THROUGH. MOVING AHEAD TO SATURDAY NIGHT AND SUNDAY...UPPER RIDGING WILL MOVE ACROSS THE AREA RESULTING IN WARM AND DRY WEATHER. LONG-TERM MODELS ARE PROJECTING ANOTHER STRONG PACIFIC TROUGH TO ADVANCE INTO THE PACIFIC NORTHWEST MONDAY. HIGHER POPS THEN ARE EXPECTED FOR MONDAY NIGHT AND TUESDAY AS THE HIGHER PWATS ARE BROUGHT IN WITH A 110+ KT JET STREAK EDGING INTO NORTHERN CALIFORNIA. SHOWERS WILL BEGIN TO WRAP UP AROUND TUESDAY NIGHT AND WEDNESDAY AS AN UPPER HIGH BEGINS BUILDING INTO THE WEST BRINGING MUCH WARMER TEMPERATURES IN THE LATTER HALF OF NEXT WEEK WITH HIGHS BACK UP IN THE 90S. HINSBERGER && .AVIATION...A LOW PRESSURE SYSTEM ADVANCING EAST ALONG THE NRN NEVADA BORDER EARLY THIS MORNING WILL LIFT NE INTO MONTANA THIS AFTERNOON WITH SCT SHOWERS AND VFR CIGS SPREADING ACROSS THE REGION THIS MORNING. PARTIAL CLEARING IS EXPECTED OVERNIGHT AS THE WAVE LIFTS FURTHER NE ACROSS MONTANA AND THE PRIMARY LOW REMAINS POSITIONED OVER THE IDAHO PANHANDLE. HUSTON && .FIRE WEATHER...EARLY MORNING SATELLITE IMAGERY SHOWED A LOW POSITIONED OVER THE IDAHO PANHANDLE AS A SECONDARY DISTURBANCE ROTATED THROUGH THE BASE OF THE LOW WORKING EAST ALONG THE NRN NEVADA BORDER WITH AN ASSOCIATED BAND OF SHOWERS ADVANCING EAST AHEAD OF THE DISTURBANCE. MODEL SOLUTIONS SUGGEST THAT THE SECONDARY WAVE WILL ROTATE THROUGH SE IDAHO THIS MORNING AND INTO SW MONTANA THIS AFTERNOON WITH ATTENDING SHOWERS FAVORED ACROSS THE SALMON-CHALLIS AND TARGHEE DISTRICTS TODAY AND TO A LESSER EXTENT THE SRN AND ERN DISTRICTS. TONIGHT AND SATURDAY...THE MAIN LOW WILL BEGIN TO SHIFT EAST INTO SW MONTANA AS AN INCREASINGLY DRIER NW FLOW OVERSPREADS THE REGION SATURDAY AFTERNOON AHEAD OF THE NEXT PACIFIC STORM SYSTEM ADVANCING INTO NW COASTAL WATERS. DISTURBANCES EJECTING FROM THIS SYSTEM ARE EXPECTED TO ROTATE THROUGH THE NW STATES EARLY NEXT WEEK PROVIDING UNSETTLE/SHOWERY CONDITIONS THROUGH AT LEAST TUESDAY. FOR THE LATTER HALF OF THE WEEK...THERE APPEARS TO BE GOOD MODEL CONSENSUS THAT A STRONG UPPER RIDGE WILL BUILD ACROSS THE WEST BRINGING WARMER THAN NORMAL TEMPERATURES BACK TO THE REGION. HUSTON && .PIH WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
408 AM CDT FRI JUN 21 2013 .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * SOUTHERLY WINDS LESS THAN 10KT THRU DAYBREAK...FREQUENT GUSTS BETWEEN 15-20KT LATE MORNING THRU EARLY EVENING. * PSBL THUNDERSTORMS AFT 20Z THRU EARLY EVENING. BEACHLER //DISCUSSION...UPDATED 06Z... REGIONAL RADAR SHOWS A BROKEN LINE OF SHOWERS AND THUNDERSTORMS JUST WEST OF THE MISSISSIPPI RIVER IN EASTERN IOWA. THIS AREA OF PRECIPITATION WAS SLIDING EAST...HOWEVER ALL GUIDANCE IS POINTING TOWARDS THIS LINE WEAKENING OVER THE NEXT SEVERAL HOURS AND NOT REACHING THE TAF SITES. FEEL RELATIVELY CONFIDENT IN THIS SCENARIO...AND HAVE CONTINUED TO KEEP THE TAF SITES DRY THRU DAYBREAK. A WEAK LOW PRESSURE CENTERED ACROSS THE CENTRAL PLAINS...WILL MAINTAIN A SOUTHERLY FLOW FOR NORTHERN IL/NORTHWEST IN AIRFIELDS TODAY. A WEAK INCREASE IN THE GRADIENT DOES APPEAR LIKELY LATE MORNING THROUGH THE AFTERN/EARLY EVENING HOURS...WHICH SHOULD RESULT IN FREQUENT GUSTS BETWEEN 15-20KT. AFT SUNSET TOWARDS 02-03Z SAT...WINDS WILL DIMINISH TO ARND 10KT FROM THE SOUTH. THE OTHER CONCERN IS FOR A COMPLEX OF THUNDERSTORMS CURRENTLY OVER THE UPPER MIDWEST...AND POSSIBLY CLIPPING NORTHERN IL/NORTHWEST IN AIRFIELDS LATER THIS AFTN. WITH INCREASING MID-LVL HIGH PRESSURE...THIS SHOULD KEEP THE BULK OF THE PRECIP TO THE NORTH. ALTHOUGH THIS BEING SAID GUIDANCE DOES INDICATE SOME THUNDERSTORMS BRUSHING THE TAF SITES. HAVE OPTED TO MAINTAIN THE MENTION WITHIN A PROB30 GROUP. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS. * HIGH CONFIDENCE IN CIGS FORECAST THRU EARLY AFTN. * MEDIUM CONFIDENCE IN PRECIP DEVELOPMENT AND COVERAGE. * LOW CONFIDENCE IN THUNDERSTORMS IMPACTING TAF SITES. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... SATURDAY...CHANCE TS. ELSE VFR. SUNDAY...VFR. MONDAY THROUGH WEDNESDAY...PERIODIC CHANCES FOR TS. ELSE VFR. ZEBIC && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
338 AM CDT FRI JUN 21 2013 .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SOUTHERLY WINDS LESS THAN 10KT THRU DAYBREAK...FREQUENT GUSTS BETWEEN 15-20KT LATE MORNING THRU EARLY EVENING. * PSBL THUNDERSTORMS AFT 20Z THRU EARLY EVENING. BEACHLER //DISCUSSION...UPDATED 06Z... REGIONAL RADAR SHOWS A BROKEN LINE OF SHOWERS AND THUNDERSTORMS JUST WEST OF THE MISSISSIPPI RIVER IN EASTERN IOWA. THIS AREA OF PRECIPITATION WAS SLIDING EAST...HOWEVER ALL GUIDANCE IS POINTING TOWARDS THIS LINE WEAKENING OVER THE NEXT SEVERAL HOURS AND NOT REACHING THE TAF SITES. FEEL RELATIVELY CONFIDENT IN THIS SCENARIO...AND HAVE CONTINUED TO KEEP THE TAF SITES DRY THRU DAYBREAK. A WEAK LOW PRESSURE CENTERED ACROSS THE CENTRAL PLAINS...WILL MAINTAIN A SOUTHERLY FLOW FOR NORTHERN IL/NORTHWEST IN AIRFIELDS TODAY. A WEAK INCREASE IN THE GRADIENT DOES APPEAR LIKELY LATE MORNING THROUGH THE AFTERN/EARLY EVENING HOURS...WHICH SHOULD RESULT IN FREQUENT GUSTS BETWEEN 15-20KT. AFT SUNSET TOWARDS 02-03Z SAT...WINDS WILL DIMINISH TO ARND 10KT FROM THE SOUTH. THE OTHER CONCERN IS FOR A COMPLEX OF THUNDERSTORMS CURRENTLY OVER THE UPPER MIDWEST...AND POSSIBLY CLIPPING NORTHERN IL/NORTHWEST IN AIRFIELDS LATER THIS AFTN. WITH INCREASING MID-LVL HIGH PRESSURE...THIS SHOULD KEEP THE BULK OF THE PRECIP TO THE NORTH. ALTHOUGH THIS BEING SAID GUIDANCE DOES INDICATE SOME THUNDERSTORMS BRUSHING THE TAF SITES. HAVE OPTED TO MAINTAIN THE MENTION WITHIN A PROB30 GROUP. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS. * HIGH CONFIDENCE IN CIGS FORECAST THRU EARLY AFTN. * MEDIUM CONFIDENCE IN PRECIP DEVELOPMENT AND COVERAGE. * LOW CONFIDENCE IN THUNDERSTORMS IMPACTING TAF SITES. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... SATURDAY...CHANCE TS. ELSE VFR. SUNDAY...VFR. MONDAY THROUGH WEDNESDAY...PERIODIC CHANCES FOR TS. ELSE VFR. ZEBIC && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS DES MOINES IA
335 AM CDT FRI JUN 21 2013 .SHORT TERM.../TODAY/... ISSUED AT 331 AM CDT FRI JUN 21 2013 LARGE CONVECTIVE COMPLEX OVER MN BEGINNING TO TURN SOUTHEAST AND BATTLING H700 CAP AT THIS TIME AS IT DOES. CONTINUED CONCERNS EARLY THIS MORNING AS TO HOW FAR SOUTH THIS WILL TURN BEFORE THE CAP BECOMES TOO STRONG FOR ANY FURTHER SOUTH DRIFT. COLD POOL HAS DEVELOPED WITH SFC WINDS AND OUTFLOW PROPAGATING BACK TO THE SOUTHWEST. THIS SUGGESTS THAT IT MAY CLIP NORTHERN IOWA WITH STORMS THIS MORNING BETWEEN 4 AND 8 AM...IF THE LINE IS ABLE TO CONTINUE BREAKING THE CAP BACK TO THE SOUTHWEST...MAY SEE ADDITIONAL STORMS INTO CENTRAL IOWA. CURRENT MESO MODELS ARE LACKING IN ANY AGREEMENT BUT THE HRRR HAS BEEN MORE REALISTIC WITH FEATURES SO FAR AND IT ONLY SCRAPES NORTHERN IOWA EARLY TODAY WITH THIS COMPLEX OF STORMS. ONCE SYSTEM MOVES EAST WILL BE LEFT WITH ANOTHER VERY WARM AND HUMID DAY. THIS WILL RESULT IN HIGHS IN THE UPPER 80S TO LOWER 90S THIS AFTERNOON WITH SOUTH WINDS AND GENEROUS DEW POINTS IN THE 60S AND LOWER 70S. MORE CONVECTION MAY DEVELOP THIS AFTERNOON NORTH OF HIGHWAY 20 ALONG ANY LINGERING OUTFLOW BOUNDARY FROM THE OVERNIGHT CONVECTIVE COMPLEX AND THIS IS MORE LIKELY AFT 19Z THROUGH THE REMAINDER OF THE AFTERNOON. WILL BE MONITORING CONVECTIVE TRENDS THROUGH THE MORNING HOURS. .LONG TERM.../TONIGHT THROUGH THURSDAY/... ISSUED AT 331 AM CDT FRI JUN 21 2013 EXTENDED FORECAST CONTINUES TO CENTER AROUND LARGE UPPER LEVEL LOW ACROSS PAC NW...AND SURFACE LOW ACROSS NORTHERN PLAINS WITH WARM FRONT IN SOUTHERN SD/MN. THIS WILL CONTINUE TO BE THE FOCUS FOR AFTERNOON CONVECTION...AND MODELS AGAIN SUGGEST MCS DEVELOPMENT OVERNIGHT. HOWEVER..AS UPPER LOW PUSHES EASTWARD...RIDGE PUSHES NORTH OF IOWA...AND UPPER LEVEL FLOW IS EXPECTED TO TAKE ANY OVERNIGHT MCS NORTH OF IOWA. THOUGH...CURRENTLY ONGOING MCS ACROSS SOUTHERN MINNESOTA MAY PRODUCE AN OUTFLOW BOUNDARY INTO NORTHERN IOWA...WHICH MAY ALLOW FOR TRACK OF MCS TO BE FURTHER SOUTH INTO NORTHERN IOWA. THOUGH GIVEN STRENGTH OF UPPER LEVEL LOW...STILL PREFER NORTHERN SOLUTION...AND HAVE KEPT POPS CONFINED TO NORTHERN IOWA OVERNIGHT. SATURDAY NIGHT LOOKS TO BE ACTIVE AS WELL...WITH FRONTAL BOUNDARY PUSHING INTO NORTHWESTERN IOWA. THIS COULD BE FOCUS FOR AFTERNOON THUNDERSTORM DEVELOPMENT...WITH AGAIN OVERNIGHT MCS...THOUGH WITH INFLUENCE FROM UPPER LOW MODELS CONTINUE TO PULL CONVECTION NORTHWEST OF IOWA...AND HAVE KEPT POPS AGAIN CONFINED TO THE NORTH...AS WARM MID LEVEL TEMPS WILL HELP TO KEEP CAP ACROSS MOST OF CENTRAL IOWA. SUNDAY FRONTAL BOUNDARY WILL PUSH INTO CENTRAL IOWA...WITH ENOUGH FORCING TO LEAD TO PROLONGED PERIODS OF PRECIPITATION THROUGH THE DAY AND OVERNIGHT...THOUGH WILL PUSH EAST OF REGION BY MONDAY. SHORTWAVE PUSHING ACROSS NE/SD BORDER WILL BRING ADDITIONAL SHOT OF PRECIPITATION FOR TUESDAY...LINGERING IN THE EAST THROUGH WEDNESDAY. TEMPERATURES WILL BE HOT THROUGH THE BEGINNING OF THE PERIOD AS SOUTHERLY SURFACE FLOW AND WAA PERSISTS UNDER RIDGE. THIS WILL ALLOW TEMPERATURES TO CLIMB INTO THE 90S ACROSS MUCH OF THE CWA...THOUGH COULD GO HIGHER THAN GOING IF ABLE TO MIX WELL. HEAT INDEX VALUES WILL BE NEAR 100 THROUGH THE WEEKEND IN THE AFTERNOONS. THIS WILL BE THE FIRST EXPOSURE SUMMER LIKE HEAT/HUMIDITY FOR MUCH OF THE REGION...AND MAY BE TAXING. HOWEVER...OVERNIGHT TEMPERATURES EXPECTED TO COOL INTO THE 70S AND WILL PROVIDE SOME RELIEF. IN ADDITION...BEHIND FRONTAL BOUNDARY MONDAY TEMPERATURES WILL COOL SOMEWHAT...BUT WILL QUICKLY REBOUND BACK INTO THE UPPER 80S AND LOW 80S FOR MOST OF THE REMAINDER OF THE PERIOD. && .AVIATION...21/06Z ISSUED AT 1204 AM CDT FRI JUN 21 2013 PLENTY OF MID/HIGH CLOUDS OVER IA AT 06Z BUT CONDITIONS REMAIN VFR...EVEN WITH SCT CONVECTION EAST OF DMX TAF SITES. CONFIDENCE IN CONVECTIVE TRENDS HAS DIMINISHED CONSIDERABLY AS NEARLY ALL MODELS HAVE OVERDONE PRECIP INTO IA THIS EVENING AND HI RES MODELS DO NOT APPEAR TO BE HANDLING PROGRESSION OF MN PRECIP WELL. THUS UNTIL TRENDS BECOME MORE CLEAR HAVE REMOVED ALL MENTION OF PRECIP. YOU COULD MAKE AN ARGUMENT FOR SOME MENTION OVERNIGHT INTO FRI AND HAVE CHOSEN DRY RATHER THAN PROLONGED LOW CONFIDENCE INCLUSION. SOUNDINGS SUGGEST SOMEWHAT BRISK SLY WINDS DURING PEAK HEATING...MUCH LIKE WHAT OCCURRED THU. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...AWB AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1204 AM CDT FRI JUN 21 2013 .UPDATE... ISSUED AT 1203 AM CDT FRI JUN 21 2013 NO SIGNIFICANT FORECAST CHANGES HAVE BEEN MADE BUT OVERALL CONFIDENCE IN CONVECTIVE TRENDS HAS DIMINISHED AS MODELS SEEM TO BE DOING A POOR JOB HANDLING REALITY AT THE MOMENT. MOST 00Z OPERATIONAL MODELS HAVE BEEN OVERZEALOUS WITH THEIR CONVECTION INTO IA THIS EVENING...AND THE MOST RECENT RUNS OF HI RES MODELS WITH THE POSSIBLE EXCEPTION OF RECENT HRRR RUNS HAVE BEEN TOO QUICK EVOLVING THE MN MCS INTO A MORE ORGANIZED LINE DROPPING TOWARD IA. MN MCS IS STILL MULTICELLULAR AND AS OF YET SHOWING LITTLE SIGNS OF CONGEALING SWD. MODEL SOUNDINGS CONTINUE TO DEPICT GRADUALLY MOISTENING TOWARD 06Z...BUT IF WARM ADVECTION DOES NOT TRIGGER CONVECTION BY 09Z GENESIS WINDOW MAY HAVE BEEN MISSED AS THIS MOISTURE WINDOWS SEEMS SOMEWHAT TRANSIENT. 03Z HRRR ONLY BARELY BRUSHES NERN SECTIONS WITH MN COMPLEX 09-12Z WITH NOTHING FARTHER SOUTH UNTIL LATER FRI MORNING. && .SHORT TERM.../TONIGHT/... ISSUED AT 407 PM CDT THU JUN 20 2013 THOUGH CAPE VALUES HAVE RANGED FROM 1000 TO 3000...WITH WIDESPREAD DEWPOINTS IN THE MID 60S...THE LACK OF A FORCING MECHANISM HAS HELPED IN PREVENTING CONVECTION FROM DEVELOPING ACROSS IOWA THUS FAR TODAY. THERE IS A DOUBLE BARRELED AREA OF LOW PRESSURE TO THE WEST...WITH ONE LOW SET UP OVER NEBRASKA...AND THE OTHER LOW OVER NORTHERN MINNESOTA. THE SOUTHERN...LARGER...AREA OF LOW PRESSURE IS NOT GOING TO MOVE VERY MUCH OVERNIGHT. THUNDERSTORMS ARE EXPECTED ACROSS PARTS OF IOWA TONIGHT...AND THEY SHOULD COME IN TWO DIFFERENT WAVES. WAVE ONE WILL BE FOCUSED OVER WESTERN IOWA TONIGHT. THERE IS A STRONG LOW LEVEL JET SET UP OVER IOWA...ALIGNED FROM SW TO NE...WHICH IS EXPECTED TO REMAIN IN PLACE AND STRENGTHEN TONIGHT...REINFORCING MOISTURE FLOW FROM THE GULF TO IOWA. A SHORT WAVE IS SLATED RIDE ALONG THE LOW AND MEET UP WITH THE ENHANCED LOW LEVEL JET TONIGHT AROUND 06Z...WHICH IS A TYPICAL TIME FOR NOCTURNAL CONVECTION TO DEVELOP...WITH THE CONDITIONS FOR OVERTURNING IN PLACE. WAVE TWO WILL COME FROM THE NORTH VIA A MCS WHICH IS EXPECTED TO DEVELOP IN THE DAKOTAS AND MOVE EAST ACROSS MINNESOTA DURING THE OVERNIGHT. WHILE MOST OF THE THUNDERSTORMS WILL BE IN MINNESOTA...STORMS WILL LIKELY MAKE IT INTO THE DMX CWA...ESPECIALLY NORTH OF INTERSTATE 80...AS A BOUNDARY SHOULD BE IN PLACE TO FOCUS THE CONVECTION FOR THE MCS. CAPE VALUES SHOULD REMAIN IN THE 1000 TO 3000 RANGE OVERNIGHT...THERE IS THETA-E ADVECTION EXPECTED ACROSS IOWA...AND THERE IS UPPER LEVEL DIVERGENCE OVER IOWA...WHICH ALL SHOULD HELP SUSTAIN THE CONVECTION ALONG THE BOUNDARY AS THE MCS PASSES THROUGH NORTHERN IOWA. WITH THE REINFORCED MOISTURE TO REMAIN IN PLACE...OVERNIGHT TEMPERATURES SHOULD REMAIN WELL ABOVE NORMAL IN THE UPPER 60S TO LOWER 70S. .LONG TERM.../FRIDAY THROUGH THURSDAY/... ISSUED AT 407 PM CDT THU JUN 20 2013 THE FORECAST IS GENERALLY PROGRESSING AS EXPECTED WITH THE COMBINATION OF UPPER LOW OVER THE PACIFIC NORTHWEST AND A SUBTROPICAL HIGH OVER THE SOUTH TO SOUTHEAST YIELDING AN INCREASING SOUTHWEST FLOW INTO IOWA. STILL POTENTIAL FOR OVERNIGHT CONVECTION TO LINGER ACROSS THE AREA THROUGH FRIDAY MORNING BEFORE AN INCREASING ELEVATED MIXED LAYER SPREADS INTO THE STATE AND CAPS MUCH OF THE AREA FOR THE REMAINDER OF THE DAY. TEMPERATURES AT 700 MB BY LATE FRIDAY WILL BE IN THE 12C-14C RANGE. AN APPROACHING SHORT WAVE FRIDAY NIGHT WILL HELP COOL THE MID LEVELS A BIT FIRE A FEW STORMS. THE PRIMARY FOCUS FOR THUNDERSTORMS ON FRIDAY AFTERNOON IS EXPECTED TO BE TO THE NORTHWEST OVER SOUTH DAKOTA. CERTAINLY POSSIBLE SOME OF THIS ACTIVITY SPILLS OVER INTO NORTH CENTRAL IOWA FRIDAY EVENING BEFORE THE CAP REESTABLISHES ON SATURDAY. ANY STORMS WOULD HAVE SEVERE POTENTIAL AND A LOCALLY HEAVY RAIN POTENTIAL WITH GOOD INSTABILITY...SUFFICIENT SHEAR AND PWATS NEARING 1.75 INCHES. ON SATURDAY THE STRONG ELEVATED MIXED LAYER REESTABLISHES WITH CONVECTIVE INHIBITIONS EXPECTED TO HOLD FOR EVERYWHERE EXCEPT POTENTIALLY NEARING THE MINNESOTA BORDER. A SERIES OF STRONG SHORT WAVES PASS THROUGH THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT AND WILL KEEP CONVECTIVE CHANCES GOING THROUGH THE PERIOD MAINLY CONFINED TO THE NORTH AND NORTHWEST BEFORE BEING MORE WIDESPREAD SUNDAY NIGHT. THE REMAINDER OF THE EXTENDED WILL FEATURE STRONG RIDGING BUILDING INTO THE INTER MOUNTAIN WEST EARLY TO MID NEXT WEEK WITH MID 20C 850 MB TEMPERATURES ENTRENCHED ACROSS IOWA. THIS WILL BE A DRIER PERIOD OVERALL BEFORE AN UPPER LOW DROPS INTO THE NORTHERN PLAINS LATE WEDNESDAY INTO THURSDAY. TEMPERATURES THROUGH THE FORECAST WILL BE SUMMER LIKE WITH WARMER AND MORE HUMID CONDITIONS ARRIVING BY FRIDAY. HIGHS IN THE UPPER 80S TO MID 90S WITH DEWPOINTS IN THE UPPER 60S TO MID 70S WILL BE COMMON THROUGHOUT LEADING HEAT INDEX VALUES EXCEEDING 100 AT TIMES. && .AVIATION...21/06Z ISSUED AT 1204 AM CDT FRI JUN 21 2013 PLENTY OF MID/HIGH CLOUDS OVER IA AT 06Z BUT CONDITIONS REMAIN VFR...EVEN WITH SCT CONVECTION EAST OF DMX TAF SITES. CONFIDENCE IN CONVECTIVE TRENDS HAS DIMINISHED CONSIDERABLY AS NEARLY ALL MODELS HAVE OVERDONE PRECIP INTO IA THIS EVENING AND HI RES MODELS DO NOT APPEAR TO BE HANDLING PROGRESSION OF MN PRECIP WELL. THUS UNTIL TRENDS BECOME MORE CLEAR HAVE REMOVED ALL MENTION OF PRECIP. YOU COULD MAKE AN ARGUMENT FOR SOME MENTION OVERNIGHT INTO FRI AND HAVE CHOSEN DRY RATHER THAN PROLONGED LOW CONFIDENCE INCLUSION. SOUNDINGS SUGGEST SOMEWHAT BRISK SLY WINDS DURING PEAK HEATING...MUCH LIKE WHAT OCCURRED THU. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...SMALL SHORT TERM...KOTENBERG LONG TERM...DONAVON AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1207 AM CDT FRI JUN 21 2013 ...UPDATE TO AVIATION... .UPDATE... ISSUED AT 1009 PM CDT THU JUN 20 2013 A FEW RECENT RUNS OF HI RES NEAR TERM MODELS...THE HRRR IN PARTICULAR...HAVE INDICATED POTENTIAL FOR THUNDERSTORMS OVER WESTERN KANSAS TO GRADUALLY WORK INTO NORTH CENTRAL KANSAS...AND PERHAPS CLIPPING THE CONCORDIA AND BELLEVILLE AREAS AROUND SUNRISE. THE ONGOING DEVELOPMENT IN WESTERN KANSAS AROUND 10 PM SEEMS TO HAVE BEEN PICKED UP WELL BY THESE MODEL RUNS...AND SEEMS TO BE LINKED TO A CONVERGENT ZONE ON THE NOSE OF AN INTENSIFYING LOW LEVEL JET EVIDENT ON DDC WIND PROFILE. WHILE THERE IS AMPLE INSTABILITY ACROSS MUCH OF CENTRAL AND EASTERN KANSAS...5000 J/KG SBCAPE WITH THE 00Z TOP SOUNDING...IT ALSO APPEARS TO BE CAPPED OFF. THE ONLY LIFTING MECHANISM CAPABLE OF OVERCOMING THIS CAP WOULD SEEM TO BE THE CONVERGENCE ALONG THE NOSE OF THE LLJ. THE LOCATION OF THIS FAVORED ASCENT IS FORECAST TO EXTEND FROM ITS CURRENT LOCATION IN WEST CENTRAL KANSAS...UP INTO SOUTH CENTRAL AND SOUTHEAST NEBRASKA. WITH THAT IN MIND...STILL FEEL PRETTY COMFORTABLE IN HAVING NO MENTION OF TSTORMS IN THE FORECAST FOR THE OVERNIGHT AND EARLY MORNING HOURS. HOWEVER...THE 10 TO 14 PERCENT CHANCE OF PRECIP OVER NORTH CENTRAL KANSAS IS THERE FOR A REASON AS THERE IS STILL A VERY SMALL CHANCE THAT A STORM OR TWO COULD MOVE INTO THAT REGION AROUND SUNRISE. WILL CONTINUE TO MONITOR THE SITUATION AND MAKE ADJUSTMENTS IF NEEDED. BARJENBRUCH && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 305 PM CDT THU JUN 20 2013 20Z WATER VAPOR SHOWS A CLOSED UPPER LOW OVER THE NORTHERN ROCKIES AND PACIFIC NORTHWEST AND A SHORTWAVE ROUNDING AN UPPER RIDGE AND MOVING INTO THE UPPER MIDWEST/GREAT LAKES REGION. SREF AND RAP MODELS SHOW THE UPPER RIDGE OVER THE SOUTHERN PLAINS TO BE GRADUALLY STRENGTHENING WITH HEIGHTS RISING OVER CENTRAL AND EASTERN KS. AT THE SURFACE...OBS SHOW A TROUGH AXIS FROM THE SOUTHERN HIGHS PLAINS NORTH INTO THE NORTHERN PLAINS. THIS HAS CAUSED A STRENGTHENING SURFACE PRESSURE GRADIENT AND GUSTY SOUTH WINDS ACROSS THE REGION. FOR TONIGHT AND FRIDAY...THE NAM HAS NOT SHOWN VERY GOOD PERFORMANCE RECENTLY WITH ITS HANDLING OF CONVECTION. THE OTHER SOLUTIONS INCLUDING THE GFS/ECMWF/GEM/ARW SUGGEST THAT WITH THE STRENGTHENING UPPER LEVEL RIDGE ACROSS THE FORECAST AREA PRECIP WILL REMAIN NORTH AND EAST OF THE FORECAST AREA THROUGH FRIDAY. SO WITH THIS IN MIND HAVE OPTED TO IGNORE THE NAM SOLUTION AND THE QPF IT BRINGS THROUGH. THERE DOES NOT APPEAR TO BE ANY STRONG FORCING IN THE FORM OF A SHORTWAVE OR STRONG ISENTROPIC LIFT OVER THE AREA TO GENERATE PRECIP...SO THE FORECAST WILL REMAIN DRY THROUGH FRIDAY. LOWS TONIGHT SHOULD BE QUITE MILD WITH THE STRONG SURFACE PRESSURE GRADIENT KEEPING WINDS UP THROUGH THE NIGHT. LOWS ARE EXPECTED TO BE IN THE LOWER TO MID 70S. HIGHS FRIDAY LOOK TO BE RATHER SIMILAR TO TODAYS BASED ON THE 850 TEMPS OF THE GFS/ECMWF/GEM. WITH THE BOUNDARY LAYER MIXING TO AROUND 850MB...HIGHS SHOULD BE IN THE LOWER TO MID 90S. WINDS FRIDAY LOOK TO BE QUITE BREEZY ONCE AGAIN WITH THE STRONG PRESSURE GRADIENT RIGHT OVER THE FORECAST AREA. CONSIDERED THE NEED FOR A WIND ADVISORY FRIDAY AFTERNOON BUT DECIDED THE LIKELIHOOD OF ADVISORY LEVEL WINDS WAS NOT HIGH ENOUGH FOR AN ADVISORY AT THIS TIME. THE NAM IS THE ONLY MODEL THAT HAS A REALLY STRONG PRESSURE GRADIENT AND SUSTAINED WINDS AROUND 30MPH. SO GIVEN ITS RECENT TRACK RECORD OVER THE LAST DAY OR TWO...DO NOT FEEL COMFORTABLE PUTTING MUCH STOCK INTO IT. LATER SHIFTS CAN REEVALUATE. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 305 PM CDT THU JUN 20 2013 FRIDAY NIGHT THROUGH SUNDAY... FRIDAY NIGHT A FRONTAL BOUNDARY IS EXPECTED TO MOVE INTO NORTHERN NEBRASKA AND NORTHEAST COLORADO. THUNDERSTORMS MAY DEVELOP ALONG THE BOUNDARY IN NEBRASKA...BUT ARE EXPECTED TO REMAIN WELL TO THE NORTH OF THE CWA. THERMAL RIDGE WILL REMAIN IN PLACE ON SATURDAY ACROSS THE CENTRAL PLAINS. THE UPPER RIDGE OVER THE CENTRAL PLAINS WILL BREAKDOWN AS A SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN ROCKIES AND NORTHERN PLAINS. THE FRONTAL BOUNDARY WILL SLIDE A LITTLE FURTHER SOUTHEAST SATURDAY NIGHT AND SUNDAY. SOME SCATTERED THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT IN NEBRASKA AND COULD AFFECT THE NORTHERN CWA. BETTER FORCING WILL REMAIN TO THE NORTH OF THE CWA. TEMPERATURES WILL REMAIN ON THE HOT SIDE WITH HIGHS IN THE 90S SATURDAY AND SUNDAY. LOWS IN THE LOWER TO MIDDLE 70S ARE EXPECTED. HEAT INDICES IN THE UPPER 90S TO LOW 100S ARE POSSIBLE EACH DAY. SUNDAY NIGHT THROUGH THURSDAY... ON SUNDAY THE MAIN SHORTWAVE TROUGH WILL BE LIFTING NORTHEAST THROUGH THE NORTHERN PLAINS WHILE THE TRAILING FRONT PUSHES SOUTH INTO EASTERN NEBRASKA AND WESTERN KANSAS. MEANWHILE AN EMBEDDED SHORTWAVE IN THE SOUTHWEST FLOW WILL SLIDE ACROSS THE REGION AIDING IN THUNDERSTORM DEVELOPMENT ALONG AND NEAR THE SFC FRONT. IT DOES APPEAR THAT THE BETTER CHANCES FOR STORMS WILL BE ACROSS AREAS NORTH OF INTERSTATE 70 SUNDAY NIGHT. AN UPPER LEVEL RIDGE WILL THEN BUILD OVER THE PLAINS CAUSING HIGH TEMPERATURES TO REACH THE MID TO UPPER 90S WITH HEAT INDICES IN THE LOW 100S MONDAY THROUGH THE PERIOD. THE RIDGE WILL CONTINUE TO BUILD MORE ACROSS THE WESTERN US WHICH WILL ALLOW THE LONGWAVE TROUGH TO DIG SOUTH ACROSS THE EASTERN US. THIS WILL BRING A FRONT INTO THE REGION ON WEDNESDAY AND THURSDAY INCREASES CHANCES FOR PRECIP. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1156 PM CDT THU JUN 20 2013 VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. EXPECT TO REMAIN BELOW LLWS CRITERIA TONIGHT BUT 1000 FT WINDS WILL BE STRONG AT 45 TO 50 KTS. WILL SEE SURFACE GUSTS OF 25 TO 30 KTS THROUGH THE DAY ON FRIDAY. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARJENBRUCH SHORT TERM...WOLTERS LONG TERM...SANDERS/WOYNICK AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
300 AM EDT FRI JUN 21 2013 .UPDATE... ISSUED AT 122 AM EDT FRI JUN 21 2013 WILL ALLOW FOR A DRY FORECAST ACROSS THE ENTIRE AREA FOR THE REST OF THE OVERNIGHT AS RADAR TRENDS HAVE SHOWED A CONTINUED GRADUAL DISSIPATION OF THE CONVECTION NEAR THE KY/TN/VA BORDERS. ALSO FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS...AND SKY COVER ACCORDING TO THE LATEST TRENDS IN OBSERVATIONS. UPDATE ISSUED AT 941 PM EDT THU JUN 20 2013 VERY FEW CHANGES NEEDED TO THE FORECAST TONIGHT. STORMS BACK- BUILDING INTO WISE COUNTY VA MAY SNEAK BACK INTO HARLAN AND LETCHER COUNTIES OVER THE NEXT HOUR OR TWO SO WILL MAINTAIN A SMALL CHANCE OF A STORM THERE FOR A FEW MORE HOURS WITH DRY CONDITIONS ANTICIPATED FOR THE REST OF THE AREA TONIGHT. FORECAST LOWS A COUPLE DEGREES WARMER THAN LAST NIGHT APPEAR ON TARGET SO NO CHANGES THERE. HAVE A GOOD NIGHT... && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 323 PM EDT THU JUN 20 2013 AS OF MID AFTERNOON...A RIDGE OF HIGH PRESSURE WAS CENTERED OVER NORTHERN MEXICO AND THE SOUTHERN PLAINS WITH RIDGING EXTENDING NORTH THROUGH THE PLAINS AND GENERAL RIDGING SOUTHEAST INTO THE GULF OF MEXICO. MEANWHILE...A SHORTWAVE IS WORKING THROUGH THE OH VALLEY WITH WEAK TROUGHING IN PLACE OVER THE LOWER OH VALLEY AND TN VALLEY REGION INTO THE SOUTHEAST. AF THE SFC...HIGH PRESSURE WAS CENTERED OVER THE NORTHEASTERN CONUS WITH RIDGING SOUTHWEST INTO THE OH VALLEY. CONVECTION SO FAR HAS GENERALLY BEEN CONFINED TO THE NORTHERN CUMBERLAND PLATEAU OF TN INTO THE LAKE CUMBERLAND REGION. FOR THE REMAINDER OF THIS AFTERNOON AND INTO THIS EVENING... CONVECTION SHOULD CONTINUE TO DEVELOP ALONG THE TN AND VA BORDERS AS THE SHORTWAVE WORKS ACROSS THE OH VALLEY. CONVECTION SHOULD WANE THROUGH THE EVENING WITH LOSS OF DAYTIME HEATING WITH CU DISSIPATING DURING THAT TIME AS WELL. AREAS OF VALLEY FOG SHOULD DEVELOP TONIGHT WITH DEWPOINTS AROUND 60 OR IN THE LOWER 60S AND A RELATIVELY WEAK PRESSURE GRADIENT IN PLACE. SOME OF THIS WILL ALMOST CERTAINLY BECOME DENSE IN THE RIVER VALLEYS...ESPECIALLY IN THE BIG SANDY REGION. POPS FOR THE REMAINDER OF THE AFTERNOON INTO THE EVENING WERE RELATIVELY UNCHANGED AS RECENT TRENDS ARE GENERALLY SUPPORTIVE OF THESE WHEN CONSIDERED WITH RECENT MODEL GUIDANCE INCLUDING RECENT HRRR RUNS THAT EVENTUALLY DEVELOP CONVECTION NEAR THE VA BORDER AND THEN HAVE A COUPLE OF GENERATIONS OF IT WORKING TOWARD THE NORTHWEST OVER THE SOUTHEASTERN COUNTIES. THE REGION WILL BE IN A GENERAL WEAKNESS BETWEEN RIDGING OVER THE ATLANTIC AND OVER THE MS VALLEY REGION WHILE A WEAK UPPER LEVEL LOW IS PROGGED OVER THE SOUTHEASTERN STATES FOR FRI AND FRI NIGHT. GENERALLY DIURNALLY DRIVEN CONVECTION IS ANTICIPATED FRI AFTERNOON INTO FRI EVENING AS THERE ARE NO OTHER REAL TRIGGERS. SLIGHT CHANCE POPS WERE USED FOR ALL AREAS ALONG SOUTH OF INTERSTATE 64 WITH A LITTLE BIT OF CHANCE OVER THE HIGHEST TERRAIN ALONG THE VA BORDER. PATCHY VALLEY FOG IS AGAIN FAVORED WITH SFC HIGH PRESSURE CENTERED TO OUR EAST AND NORTHEAST WITH RELATIVELY HIGH DEWPOINTS AND A WEAK PRESSURE GRADIENT. MUCH OF THE CLOUD COVER SHOULD THIN ON FRI NIGHT WITH LOSS OF DAYTIME HEATING. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 AM EDT FRI JUN 21 2013 THE MODELS BEGIN THE EXTENDED WITH PRETTY GOOD AGREEMENT ALOFT AS THE WESTERLIES ARE WELL TO THE NORTH OF THE AREA WHILE GENERALLY WEAK RIDGING IS FOUND THROUGH THE SOUTHEAST THIRD OF THE NATION. EMBEDDED WITHIN THIS RIDGE IS A WEAKNESS CENTERED OVER THE NORTHERN GEORGIA AND ALABAMA LINE. THIS LOCALIZED AREA OF LOWER HEIGHTS WILL OPEN UP AND DRIFT NORTHEAST THROUGH THE LATTER PART OF THE WEEKEND AND START OF THE NEXT WORK WEEK...SPREADING ITS LIMITED INFLUENCE THROUGH THE SOUTHERN APPALACHIANS. FOR SUCH A WEAK FEATURE... CONSISTENT WITH THIS TIME OF YEAR...THE MODELS DO RATHER WELL IN DEPICTING SIMILAR EVOLUTIONS...THOUGH THE ECMWF MAINTAINS THE DISTINCT UPPER LOW LONGER THAN THE GFS AND GEM. BY MONDAY NIGHT... THIS AREA OF WEAKNESS WILL HAVE SUPPRESSED THIS PART OF THE RIDGE AS ITS CORE STARTS TO PUSH MORE WESTERLY...MAKING FOR LOWER HEIGHTS FOR OUR AREA AND A BIT BETTER INTERACTION WITH THE WESTERLIES AREA... STILL RUNNING MAINLY NORTH OF THE GREAT LAKES. LOWER HEIGHTS ON THE NORTHEAST SIDE OF THE...NOW SOUTHWEST...RIDGE WILL BE THE RULE THROUGH THE MIDDLE OF NEXT WEEK AS THE MID LEVEL WAVES MOVING BY TO THE NORTH PASS INCREASINGLY CLOSER TO EASTERN KENTUCKY. AS THE RIDGE RETROGRADES FURTHER WEST AND THEN NORTH...BUILDING AS IT DOES...THE SOUTHERN MOST OF THESE WAVES LOOKS TO CROSS THROUGH THE OHIO VALLEY ON THURSDAY...IN THE ECMWF. MEANWHILE...THE GFS TAKES A PROPER TROUGH INTO THE UPPER MIDWEST AND DROPS ITS INFLUENCE SOUTHEAST INTO AND THROUGH THE BREADTH OF THE OHIO VALLEY BY THURSDAY EVENING. FOR NOW WILL LEAN TOWARD THE MORE PROGRESSIVE ECMWF SOLUTION...THOUGH BOTH ARE HINTING AT A DECENT PATTERN ADJUSTMENT WROUGHT BY THE BUILDING RIDGE OVER THE CENTRAL AND SOUTHERN ROCKIES TOWARD THE END OF THE WEEK. SENSIBLE WEATHER WILL BE DOMINATED BY THE DIURNAL CYCLE THROUGH THE BULK OF THE EXTENDED AS SFC HIGH PRESSURE OVER THE AREA WILL BE TOO WEAK TO SUPPRESS CONVECTION ONCE THE DAYTIME HEATING TAKES HOLD. EVEN SO...THERE REALLY IS NO FEATURE TO KEY IN ON FOR MORE WIDESPREAD OR ORGANIZED ACTIVITY THROUGH THE START OF THE NEW WORK WEEK. THAT CHANGES BY WEDNESDAY AS FALLING HEIGHTS AND ENERGY FROM THE WESTERLIES AT MID LEVELS SHOULD BE ENOUGH TO HELP GENERATE BETTER CLUSTERS OF STORMS FOR OUR AREA...THOUGH TIMING AND SPECIFICS REMAIN IN DOUBT. WARM AND SEASONABLE WEATHER IS THUS ON TAP FOR THE REST OF THE WEEKEND THROUGH THE START OF THE NEW WORK WEEK BEFORE A LITTLE MORE CLOUDS AND CONVECTION FROM MID WEEK ON...TEMPER THE WARMTH A BIT. THE CR GRID LOAD CAME IN A BIT HEAVY ON THE POPS...ESPECIALLY EARLY. DID MAKE HOURLY ADJUSTMENTS TO THE POPS AND SKY COVER TO BETTER REFLECT THE TIMES OF PEAK CONVECTION SUNDAY INTO TUESDAY. ALSO MADE SOME FINE TUNE ADJUSTMENTS TO TEMPERATURES EACH NIGHT BASED ON RELATIVE ELEVATIONAL DIFFERENCES FROM SATURDAY NIGHT THROUGH MONDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 122 AM EDT FRI JUN 21 2013 SURFACE HIGH PRESSURE WILL PROVIDE FOR MAINLY VFR CONDITIONS AND LIGHT WINDS ACROSS THE AREA THROUGH THE PERIOD. THERE WILL BE SOME IFR OR WORSE FOG TO CONTEND WITH IN THE DEEPER RIVER VALLEYS THROUGH 13 OR 14Z...HOWEVER EXPECT THIS TO STEER CLEAR OF THE TAF SITES...WITH PERHAPS JUST SOME TEMPORARY MVFR BETWEEN 10 AND 12Z AT SME AND LOZ. DURING PEAK HEATING...A FEW SHOWERS AND STORMS WILL ALSO THREATEN THE AREA...HOWEVER THE COVERAGE LOOKS TO BE TOO LIMITED TO INCLUDE A MENTION IN THE TAFS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JP LONG TERM...GREIF AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
122 AM EDT FRI JUN 21 2013 .UPDATE... ISSUED AT 122 AM EDT FRI JUN 21 2013 WILL ALLOW FOR A DRY FORECAST ACROSS THE ENTIRE AREA FOR THE REST OF THE OVERNIGHT AS RADAR TRENDS HAVE SHOWED A CONTINUED GRADUAL DISSIPATION OF THE CONVECTION NEAR THE KY/TN/VA BORDERS. ALSO FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS...AND SKY COVER ACCORDING TO THE LATEST TRENDS IN OBSERVATIONS. UPDATE ISSUED AT 941 PM EDT THU JUN 20 2013 VERY FEW CHANGES NEEDED TO THE FORECAST TONIGHT. STORMS BACK- BUILDING INTO WISE COUNTY VA MAY SNEAK BACK INTO HARLAN AND LETCHER COUNTIES OVER THE NEXT HOUR OR TWO SO WILL MAINTAIN A SMALL CHANCE OF A STORM THERE FOR A FEW MORE HOURS WITH DRY CONDITIONS ANTICIPATED FOR THE REST OF THE AREA TONIGHT. FORECAST LOWS A COUPLE DEGREES WARMER THAN LAST NIGHT APPEAR ON TARGET SO NO CHANGES THERE. HAVE A GOOD NIGHT... && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 323 PM EDT THU JUN 20 2013 AS OF MID AFTERNOON...A RIDGE OF HIGH PRESSURE WAS CENTERED OVER NORTHERN MEXICO AND THE SOUTHERN PLAINS WITH RIDGING EXTENDING NORTH THROUGH THE PLAINS AND GENERAL RIDGING SOUTHEAST INTO THE GULF OF MEXICO. MEANWHILE...A SHORTWAVE IS WORKING THROUGH THE OH VALLEY WITH WEAK TROUGHING IN PLACE OVER THE LOWER OH VALLEY AND TN VALLEY REGION INTO THE SOUTHEAST. AF THE SFC...HIGH PRESSURE WAS CENTERED OVER THE NORTHEASTERN CONUS WITH RIDGING SOUTHWEST INTO THE OH VALLEY. CONVECTION SO FAR HAS GENERALLY BEEN CONFINED TO THE NORTHERN CUMBERLAND PLATEAU OF TN INTO THE LAKE CUMBERLAND REGION. FOR THE REMAINDER OF THIS AFTERNOON AND INTO THIS EVENING... CONVECTION SHOULD CONTINUE TO DEVELOP ALONG THE TN AND VA BORDERS AS THE SHORTWAVE WORKS ACROSS THE OH VALLEY. CONVECTION SHOULD WANE THROUGH THE EVENING WITH LOSS OF DAYTIME HEATING WITH CU DISSIPATING DURING THAT TIME AS WELL. AREAS OF VALLEY FOG SHOULD DEVELOP TONIGHT WITH DEWPOINTS AROUND 60 OR IN THE LOWER 60S AND A RELATIVELY WEAK PRESSURE GRADIENT IN PLACE. SOME OF THIS WILL ALMOST CERTAINLY BECOME DENSE IN THE RIVER VALLEYS...ESPECIALLY IN THE BIG SANDY REGION. POPS FOR THE REMAINDER OF THE AFTERNOON INTO THE EVENING WERE RELATIVELY UNCHANGED AS RECENT TRENDS ARE GENERALLY SUPPORTIVE OF THESE WHEN CONSIDERED WITH RECENT MODEL GUIDANCE INCLUDING RECENT HRRR RUNS THAT EVENTUALLY DEVELOP CONVECTION NEAR THE VA BORDER AND THEN HAVE A COUPLE OF GENERATIONS OF IT WORKING TOWARD THE NORTHWEST OVER THE SOUTHEASTERN COUNTIES. THE REGION WILL BE IN A GENERAL WEAKNESS BETWEEN RIDGING OVER THE ATLANTIC AND OVER THE MS VALLEY REGION WHILE A WEAK UPPER LEVEL LOW IS PROGGED OVER THE SOUTHEASTERN STATES FOR FRI AND FRI NIGHT. GENERALLY DIURNALLY DRIVEN CONVECTION IS ANTICIPATED FRI AFTERNOON INTO FRI EVENING AS THERE ARE NO OTHER REAL TRIGGERS. SLIGHT CHANCE POPS WERE USED FOR ALL AREAS ALONG SOUTH OF INTERSTATE 64 WITH A LITTLE BIT OF CHANCE OVER THE HIGHEST TERRAIN ALONG THE VA BORDER. PATCHY VALLEY FOG IS AGAIN FAVORED WITH SFC HIGH PRESSURE CENTERED TO OUR EAST AND NORTHEAST WITH RELATIVELY HIGH DEWPOINTS AND A WEAK PRESSURE GRADIENT. MUCH OF THE CLOUD COVER SHOULD THIN ON FRI NIGHT WITH LOSS OF DAYTIME HEATING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 339 PM EDT THU JUN 20 2013 THE LONG TERM STARTS OUT ON SATURDAY WITH AN UPPER RIDGE DOMINATING THE SOUTHEAST COAST WITH A RESIDUAL WEAK CUTOFF UPPER LOW LOCATED NEAR THE AL-TN-GA BORDER. CONFIDENCE IN THE FORECAST IS VERY LOW BECAUSE THE MODELS REALLY DO NOT DO VERY WELL WITH THESE RESIDUAL LOWS THIS TIME OF THE YEAR. THE FORECAST POSITIONS CAN BE VASTLY DIFFERENT BASED ON THE POSITION OF THE UPPER LOW...AS IT CAN BRING WITH IT INCREASED INSTABILITY AND A GREATER CHANCE FOR PRECIPITATION. IN GENERAL...CONDITIONS WILL BE WARM WITH LOTS OF CONVECTIVE ACTIVITY. THE THUNDER SHOULD TEND TO HAVE AN AFTERNOON AND EARLY EVENING MAXIMUM...HOWEVER AN ISOLATED STORM MAY CONTINUE INTO THE OVERNIGHT HOURS. SOME OF THE STORMS MAY BECOME STRONG HOWEVER SHOULD STAY BELOW SEVERE CRITERIA. IN PLACES WHERE THUNDERSTORMS DO OCCUR...THERE COULD BE SOME LOCALIZED HIGH WATER WITH DITCHES AND LOW WATER CROSSINGS RUNNING FULL DUE TO THE VERY SLOW MOVEMENT OF THE STORMS. TEMPERATURES WILL CONTINUE TO BE VERY SEASONAL WITH HIGH TEMPERATURES STAYING IN THE MID 80S. THIS PATTERN SHOULD CONTINUE THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 122 AM EDT FRI JUN 21 2013 SURFACE HIGH PRESSURE WILL PROVIDE FOR MAINLY VFR CONDITIONS AND LIGHT WINDS ACROSS THE AREA THROUGH THE PERIOD. THERE WILL BE SOME IFR OR WORSE FOG TO CONTEND WITH IN THE DEEPER RIVER VALLEYS THROUGH 13 OR 14Z...HOWEVER EXPECT THIS TO STEER CLEAR OF THE TAF SITES...WITH PERHAPS JUST SOME TEMPORARY MVFR BETWEEN 10 AND 12Z AT SME AND LOZ. DURING PEAK HEATING...A FEW SHOWERS AND STORMS WILL ALSO THREATEN THE AREA...HOWEVER THE COVERAGE LOOKS TO BE TOO LIMITED TO INCLUDE A MENTION IN THE TAFS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JP LONG TERM...JJ AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
455 AM EDT FRI JUN 21 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 431 PM EDT THU JUN 20 2013 UPPER AIR PATTERN FEATURES DEEP TROUGHING OVER NORTHWEST CONUS WITH RIDGING DOWNSTREAM OVER NORTHERN PLAINS. SFC FRONT WITH DRIER AIR IS WORKING ACROSS DAKOTAS WITH WEAK SFC LOW OVR NCNTRL SD BTWN KBIS AND KABR. BASED ON SFC OBS AND VIS SATELLITE APPEARS WARM FRONT EXTENDS FROM SFC LOW ACROSS CNTRL MN AND INTO NORTHWEST WI. NOT MUCH OF A TEMP GRADIENT AT H85 BUT RIBBON OF HIGHER H85-H7 DWPNT ALONG WITH H85 CONVERGENCE FROM NORTHERN MN ACROSS UPR MICHIGAN IS SERVING AS FOCUS WAVE AFTER WAVE OF SCT SHRA/ISOLD TSRA. NO STRONG TSTM THOUGH AS CAPE AVAILABLE OVR THE AREA IS BLO 1000 J/KG. DEEP LAYER SHEAR IS MARGINAL AS WELL...MAYBE UP TO 30 KTS. STRONGEST CONVECTION TODAY HAVE HAD LIGHTNING BUT HAVE REALLY SHOWN LITTLE TILT OWING TO THE LIMITED INSTABILITY/SHEAR. BASED ON WV LOOP/LIGHTNING AND RUC ANALYSIS...DOES SEEM THAT THERE IS ONE WEAKER SHORTWAVE OVER NORTHWEST WI...ANOTHER NEAR THE DLH AREA...AND A STRONGER WAVE LIFTING ENE ACROSS NORTHEAST ND. EXPECT ISOLD-SCATTERED SHRA AND TSRA OVR CWA THROUGH EVENING...ESPECIALLY NORTHERN HALF...AS THESE WAVES SLIDE THROUGH ALONG THE BOUNDARY AT H85. OVERALL...LIMITED INSTABILITY SHOULD PRECLUDE STRONGER STORMS THIS EVENING OVR MUCH OF CWA. EXCEPTION MAY BE IN FAR SW VCNTY OF IWD AS MLCAPE BUILDING UP OVER 1000J/KG JUST TO SOUTHWEST OF WEST CWA AND SWRLY STORM MOTION COULD RESULT IN STRONGER STORM WITH GUSTY WINDS AND HAIL. THUS FAR NO REAL INDICATIONS OF THIS WITH UPSTREAM STORMS BUT IT IS SOMETHING TO WATCH. LATER TONIGHT...MAIN QUESTION IS WHAT WILL OCCUR WITH UPSTREAM CONVECTION. IN A NUTSHELL...APPEARS THAT IF PRIMARY AREA OF CONVECTIVE DEVELOPING THROUGH EARLY EVENING OCCURS ALONG AND EAST OF SFC LOW...850-300MB THICKNESS/ORIENTATION OF HIGHEST MUCAPE/FORWARD PROPAGATING CORFIDI VECTORS POINT TO MAIN TRACK OF SHRA/TSRA COMPLEX OR BONIFIDE MCS MAINLY STAYING SOUTH OF CWA...WOULD BE CLOSE IN THE SOUTHWEST CWA THOUGH. ON THE OTHER HAND...IF CONVECTION OVR NORTHEAST ND CONTINUES TO DRIFT ACROSS RIDGE TOP IT COULD ADVECT AND/OR SPUR ON ADDITIONAL SHRA/TSRA OVERNIGHT IN NORTHERN MN AND BASED ON 850-300MB THICKNESSES...SHRA/TSRA WOULD TRACK INTO FAR WESTERN UPR MICHIGAN 08Z-12Z. INCREASING SFC-ML CAPES AND 0-1KM SHEAR UP TO 20 KTS AND BOW-LIKE APPEARANCE FROM VARIOUS HIGHER RESOLUTION MODELS INDICATE IF THIS CONVECTION IMPACTS WESTERN CWA THERE COULD BE STRONG WIND GUSTS. WITH ALL THE CLOUD COVER AND POSSIBLE SHRA/TSRA WILL BE A WARM NIGHT WITH LOWS IN THE MID 50S EAST AND STAYING ABOVE 60 DEGREES OVER THE WEST. FOR FRIDAY...CONDITIONAL FORECAST FOR SURE. IF THE SHRA/TSRA ARE AROUND IN THE MORNING...EXPECT A GENERAL LULL LATE MORNING INTO MOST OF THE AFTN DUE TO THE SUBSIDENCE IN WAKE OF THE CONVECTION. MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 70S IF NOT REACHING 80 WITH ENOUGH SUNSHINE. AFTN INSTABILITY AND WARM FRONT/OUTFLOW IN THE VCNTY COULD LEAD TO MORE DEVELOPING SHRA/TSRA MID-LATE AFTN. LOW CHANCE POPS FOR ALL AREAS AFTER THE MAIN SHRA/TSRA CHANCES IN THE MORNING. BEST CHANCE IN THE AFTN WOULD PROBABLY BE IN THE WEST/SOUTHWEST CWA WITH BETTER SHOT OF EARLIER CLEARING/WARMER TEMPERATURES. HUMID CONDITIONS THAT HAVE DEVELOPED TODAY WILL CONTINUE THROUGH FRIDAY WITH DWPNTS STAYING AT OR ABOVE 60 IN MANY AREAS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 431 AM EDT FRI JUN 21 2013 UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH OVER THE WESTERN U.S. AND A SHORTWAVE OVER THE UPPER MISSISSIPPI RIVER VALLEY WITH A RIDGE OVER THE UPPER GREAT LAKES 12Z SAT. THE TROUGH AND SHORTWAVE MOVE THROUGH THE AREA THIS WEEKEND AND WILL BRING UNSETTLED WEATHER TO THE AREA. THIS IS GOING TO BE HARD TO TIME ANY LITTLE WAVES THAT MOVE THROUGH THE AREA. WITH A FRONT IN THE AREA...HARD TO TIME POPS AND WILL CONTINUE WITH THE CHANCE POPS THAT WERE IN THERE. ONE THING I DID DO THOUGH WAS RAISE HIGH TEMPERATURES A BIT FOR SAT AND SUNDAY. 850 MB TEMPERATURES ALOFT GET CLOSE TO 20C AND MIXING THIS DOWN TO THE SFC GIVES ME HIGHS NEAR 90 ON SUNDAY. WENT LOWER 80S ON SATURDAY AND MID TO UPPER 80S ON SUNDAY. ANY SUNSHINE WILL HELP WARM THE TEMPERATURES UP AND AGAIN DO NOT THINK BOTH DAYS WILL BE WASHOUTS BY ANY MEANS. BROADBRUSHING CHANCE POPS LOOKS GOOD FOR BOTH DAYS. OTHERWISE...NO MAJOR CHANGES TO THE GOING FORECAST. LOOKS HUMID AND WARM AS WELL. IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB RIDGE ACROSS THE SOUTHERN AND EASTERN U.S. 12Z MON WITH A DEEP TROUGH ACROSS THE WESTERN U.S. THERE IS ALSO A SHORTWAVE TROUGH MOVING THROUGH SOUTH CENTRAL CANADA AT THAT TIME. THIS SHORTWAVE HELPS TO FLATTEN THE RIDGE A BIT OVER THE AREA AND CONTINUE TO PUT THE AREA IN THE RING OF FIRE CONVECTION SCENARIO ON THE EDGE OF THE RIDGE. ANY SHORTWAVE THAT MOVES THROUGH HAS THE POTENTIAL TO KICK OFF SOME SHOWERS AND THUNDERSTORMS. UPPER PATTERN THEN EVOLVES INTO A RIDGE ACROSS THE ROCKIES ON THU WITH TROUGHING OVER THE UPPER GREAT LAKES THEN WITH AREA STILL IN THE RING OF FIRE SCENARIO THEN. LOOKS PRETTY UNSETTLED THROUGH THIS EXTENDED PERIOD ALONG WITH SOME WARMER WEATHER AND ABOVE NORMAL TEMPERATURES AND HUMIDITY THIS FORECAST PERIOD. TRYING TO TIME THE PERIODS OF CONVECTION WILL BE DIFFICULT AND DO NOT THINK THE WHOLE TIME WILL BE A WASHOUT EITHER AS THERE WILL BE SOME BRIEF DRY PERIODS IN THERE. BROADBRUSHING CHANCE POPS FOR THE PERIOD LOOKS GOOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1212 AM EDT FRI JUN 21 2013 WILL BE A CHALLENGING FCST THRU THIS PERIOD DUE TO UNCERTAINTIES IN CONVECTION AND LOW CLOUDS/FOG. INITIALLY...AS EXPECTED...MAIN AREAS OF TSRA SO FAR TONIGHT HAVE BEEN SLIDING SE TO THE S OF THE AREA AS CONVECTION FOLLOWS 850-300MB THICKNESS PATTERN. SHRA FARTHER N THAT HAVE BEEN AFFECTING KIWD/KCMX/KSAW SHOULD DIMINISH FOR A WHILE. AT KCMX...COOL EASTERLY UPSLOPE FLOW OFF LAKE SUPERIOR INTO HIGHER DWPT AIR MASS OVER THE KEWEENAW HAS RESULTED IN LIFR CONDITIONS...AND LIFR WILL LINGER THRU THE NIGHT UNDER CONTINUED LIGHT EASTERLY WINDS. AT KSAW...WITH -SHRA DIMINISHING...FOG/MVFR CONDITIONS SHOULD PREVAIL OVERNIGHT. NOT OUT OF THE QUESTION THAT CONDITIONS COULD FALL TO IFR WITH FOG/STRATUS. DOWNSLOPE E/SE WINDS SHOULD ALLOW VFR CONDITIONS OVERNIGHT AT KIWD THOUGH MVFR WILL OCCUR WITH ANY SHRA/TSRA. LATER IN THE NIGHT...DISTURBANCE EMERGING FROM THE NRN PLAINS SHOULD SUPPORT A MORE ORGANIZED CLUSTER OF SHRA/TSRA SPREADING TOWARD THE AREA. GIVEN ARRIVAL DURING THE MORNING IN THE USUAL DIURNAL MIN FOR CONVECTION...TSRA POTENTIAL SHOULD BE MORE LIMITED. INCLUDED MVFR CONDITIONS WITH SHRA/VCTS AT KIWD...BUT JUST SHRA AT KCMX/KSAW. AFTER A FEW HRS OF PCPN...CONDITIONS SHOULD BREAK OUT TO VFR AT KIWD/KSAW...BUT MAY RETURN TO IFR UNDER CONTINUED COOL UPSLOPE EASTERLY FLOW AT KCMX. EXPECT A BREAK OUT TO VFR AT KCMX IN THE AFTN. ADDITIONAL CONVECTIVE DEVELOPMENT THIS AFTN/EVENING IS UNCERTAIN. FOR NOW...WILL PLAN FOR A MORE LIKELY DRY SCENARIO IN THE WAKE OF SHORTWAVE PASSING IN THE MORNING/EARLY AFTN. FOG MVFR CONDITIONS MAY DEVELOP THIS EVENING AT KIWD/KSAW WHILE COOL EASTERLY UPSLOPE FLOW ARGUES FOR A RETURN TO LIFR AT KCMX. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 455 AM EDT FRI JUN 21 2013 WINDS SHOULD REMAIN AROUND 25KTS OR LESS...WITH THE MAIN THREAT BEING SHOWERS AND THUNDERSTORMS...AND FOG THROUGH THE ENTIRE PERIOD. WHILE THE PRESSURE WILL ONLY CHANGE MARGINALLY THROUGH TUESDAY...A TROUGH OF LOW PRESSURE WILL BE OVER OR NEAR LAKE SUPERIOR...WITH STRONGER LOW PRESSURE TO OUR WEST PUSHING ROUNDS OF MOIST UNSTABLE AIR NORTHWARD ACROSS THE GREAT LAKES REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...07 AVIATION...ROLFSON MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 AM EDT FRI JUN 21 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 431 PM EDT THU JUN 20 2013 UPPER AIR PATTERN FEATURES DEEP TROUGHING OVER NORTHWEST CONUS WITH RIDGING DOWNSTREAM OVER NORTHERN PLAINS. SFC FRONT WITH DRIER AIR IS WORKING ACROSS DAKOTAS WITH WEAK SFC LOW OVR NCNTRL SD BTWN KBIS AND KABR. BASED ON SFC OBS AND VIS SATELLITE APPEARS WARM FRONT EXTENDS FROM SFC LOW ACROSS CNTRL MN AND INTO NORTHWEST WI. NOT MUCH OF A TEMP GRADIENT AT H85 BUT RIBBON OF HIGHER H85-H7 DWPNT ALONG WITH H85 CONVERGENCE FROM NORTHERN MN ACROSS UPR MICHIGAN IS SERVING AS FOCUS WAVE AFTER WAVE OF SCT SHRA/ISOLD TSRA. NO STRONG TSTM THOUGH AS CAPE AVAILABLE OVR THE AREA IS BLO 1000 J/KG. DEEP LAYER SHEAR IS MARGINAL AS WELL...MAYBE UP TO 30 KTS. STRONGEST CONVECTION TODAY HAVE HAD LIGHTNING BUT HAVE REALLY SHOWN LITTLE TILT OWING TO THE LIMITED INSTABILITY/SHEAR. BASED ON WV LOOP/LIGHTNING AND RUC ANALYSIS...DOES SEEM THAT THERE IS ONE WEAKER SHORTWAVE OVER NORTHWEST WI...ANOTHER NEAR THE DLH AREA...AND A STRONGER WAVE LIFTING ENE ACROSS NORTHEAST ND. EXPECT ISOLD-SCATTERED SHRA AND TSRA OVR CWA THROUGH EVENING...ESPECIALLY NORTHERN HALF...AS THESE WAVES SLIDE THROUGH ALONG THE BOUNDARY AT H85. OVERALL...LIMITED INSTABILITY SHOULD PRECLUDE STRONGER STORMS THIS EVENING OVR MUCH OF CWA. EXCEPTION MAY BE IN FAR SW VCNTY OF IWD AS MLCAPE BUILDING UP OVER 1000J/KG JUST TO SOUTHWEST OF WEST CWA AND SWRLY STORM MOTION COULD RESULT IN STRONGER STORM WITH GUSTY WINDS AND HAIL. THUS FAR NO REAL INDICATIONS OF THIS WITH UPSTREAM STORMS BUT IT IS SOMETHING TO WATCH. LATER TONIGHT...MAIN QUESTION IS WHAT WILL OCCUR WITH UPSTREAM CONVECTION. IN A NUTSHELL...APPEARS THAT IF PRIMARY AREA OF CONVECTIVE DEVELOPING THROUGH EARLY EVENING OCCURS ALONG AND EAST OF SFC LOW...850-300MB THICKNESS/ORIENTATION OF HIGHEST MUCAPE/FORWARD PROPAGATING CORFIDI VECTORS POINT TO MAIN TRACK OF SHRA/TSRA COMPLEX OR BONIFIDE MCS MAINLY STAYING SOUTH OF CWA...WOULD BE CLOSE IN THE SOUTHWEST CWA THOUGH. ON THE OTHER HAND...IF CONVECTION OVR NORTHEAST ND CONTINUES TO DRIFT ACROSS RIDGE TOP IT COULD ADVECT AND/OR SPUR ON ADDITIONAL SHRA/TSRA OVERNIGHT IN NORTHERN MN AND BASED ON 850-300MB THICKNESSES...SHRA/TSRA WOULD TRACK INTO FAR WESTERN UPR MICHIGAN 08Z-12Z. INCREASING SFC-ML CAPES AND 0-1KM SHEAR UP TO 20 KTS AND BOW-LIKE APPEARANCE FROM VARIOUS HIGHER RESOLUTION MODELS INDICATE IF THIS CONVECTION IMPACTS WESTERN CWA THERE COULD BE STRONG WIND GUSTS. WITH ALL THE CLOUD COVER AND POSSIBLE SHRA/TSRA WILL BE A WARM NIGHT WITH LOWS IN THE MID 50S EAST AND STAYING ABOVE 60 DEGREES OVER THE WEST. FOR FRIDAY...CONDITIONAL FORECAST FOR SURE. IF THE SHRA/TSRA ARE AROUND IN THE MORNING...EXPECT A GENERAL LULL LATE MORNING INTO MOST OF THE AFTN DUE TO THE SUBSIDENCE IN WAKE OF THE CONVECTION. MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 70S IF NOT REACHING 80 WITH ENOUGH SUNSHINE. AFTN INSTABILITY AND WARM FRONT/OUTFLOW IN THE VCNTY COULD LEAD TO MORE DEVELOPING SHRA/TSRA MID-LATE AFTN. LOW CHANCE POPS FOR ALL AREAS AFTER THE MAIN SHRA/TSRA CHANCES IN THE MORNING. BEST CHANCE IN THE AFTN WOULD PROBABLY BE IN THE WEST/SOUTHWEST CWA WITH BETTER SHOT OF EARLIER CLEARING/WARMER TEMPERATURES. HUMID CONDITIONS THAT HAVE DEVELOPED TODAY WILL CONTINUE THROUGH FRIDAY WITH DWPNTS STAYING AT OR ABOVE 60 IN MANY AREAS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 431 AM EDT FRI JUN 21 2013 UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH OVER THE WESTERN U.S. AND A SHORTWAVE OVER THE UPPER MISSISSIPPI RIVER VALLEY WITH A RIDGE OVER THE UPPER GREAT LAKES 12Z SAT. THE TROUGH AND SHORTWAVE MOVE THROUGH THE AREA THIS WEEKEND AND WILL BRING UNSETTLED WEATHER TO THE AREA. THIS IS GOING TO BE HARD TO TIME ANY LITTLE WAVES THAT MOVE THROUGH THE AREA. WITH A FRONT IN THE AREA...HARD TO TIME POPS AND WILL CONTINUE WITH THE CHANCE POPS THAT WERE IN THERE. ONE THING I DID DO THOUGH WAS RAISE HIGH TEMPERATURES A BIT FOR SAT AND SUNDAY. 850 MB TEMPERATURES ALOFT GET CLOSE TO 20C AND MIXING THIS DOWN TO THE SFC GIVES ME HIGHS NEAR 90 ON SUNDAY. WENT LOWER 80S ON SATURDAY AND MID TO UPPER 80S ON SUNDAY. ANY SUNSHINE WILL HELP WARM THE TEMPERATURES UP AND AGAIN DO NOT THINK BOTH DAYS WILL BE WASHOUTS BY ANY MEANS. BROADBRUSHING CHANCE POPS LOOKS GOOD FOR BOTH DAYS. OTHERWISE...NO MAJOR CHANGES TO THE GOING FORECAST. LOOKS HUMID AND WARM AS WELL. IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB RIDGE ACROSS THE SOUTHERN AND EASTERN U.S. 12Z MON WITH A DEEP TROUGH ACROSS THE WESTERN U.S. THERE IS ALSO A SHORTWAVE TROUGH MOVING THROUGH SOUTH CENTRAL CANADA AT THAT TIME. THIS SHORTWAVE HELPS TO FLATTEN THE RIDGE A BIT OVER THE AREA AND CONTINUE TO PUT THE AREA IN THE RING OF FIRE CONVECTION SCENARIO ON THE EDGE OF THE RIDGE. ANY SHORTWAVE THAT MOVES THROUGH HAS THE POTENTIAL TO KICK OFF SOME SHOWERS AND THUNDERSTORMS. UPPER PATTERN THEN EVOLVES INTO A RIDGE ACROSS THE ROCKIES ON THU WITH TROUGHING OVER THE UPPER GREAT LAKES THEN WITH AREA STILL IN THE RING OF FIRE SCENARIO THEN. LOOKS PRETTY UNSETTLED THROUGH THIS EXTENDED PERIOD ALONG WITH SOME WARMER WEATHER AND ABOVE NORMAL TEMPERATURES AND HUMIDITY THIS FORECAST PERIOD. TRYING TO TIME THE PERIODS OF CONVECTION WILL BE DIFFICULT AND DO NOT THINK THE WHOLE TIME WILL BE A WASHOUT EITHER AS THERE WILL BE SOME BRIEF DRY PERIODS IN THERE. BROADBRUSHING CHANCE POPS FOR THE PERIOD LOOKS GOOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1212 AM EDT FRI JUN 21 2013 WILL BE A CHALLENGING FCST THRU THIS PERIOD DUE TO UNCERTAINTIES IN CONVECTION AND LOW CLOUDS/FOG. INITIALLY...AS EXPECTED...MAIN AREAS OF TSRA SO FAR TONIGHT HAVE BEEN SLIDING SE TO THE S OF THE AREA AS CONVECTION FOLLOWS 850-300MB THICKNESS PATTERN. SHRA FARTHER N THAT HAVE BEEN AFFECTING KIWD/KCMX/KSAW SHOULD DIMINISH FOR A WHILE. AT KCMX...COOL EASTERLY UPSLOPE FLOW OFF LAKE SUPERIOR INTO HIGHER DWPT AIR MASS OVER THE KEWEENAW HAS RESULTED IN LIFR CONDITIONS...AND LIFR WILL LINGER THRU THE NIGHT UNDER CONTINUED LIGHT EASTERLY WINDS. AT KSAW...WITH -SHRA DIMINISHING...FOG/MVFR CONDITIONS SHOULD PREVAIL OVERNIGHT. NOT OUT OF THE QUESTION THAT CONDITIONS COULD FALL TO IFR WITH FOG/STRATUS. DOWNSLOPE E/SE WINDS SHOULD ALLOW VFR CONDITIONS OVERNIGHT AT KIWD THOUGH MVFR WILL OCCUR WITH ANY SHRA/TSRA. LATER IN THE NIGHT...DISTURBANCE EMERGING FROM THE NRN PLAINS SHOULD SUPPORT A MORE ORGANIZED CLUSTER OF SHRA/TSRA SPREADING TOWARD THE AREA. GIVEN ARRIVAL DURING THE MORNING IN THE USUAL DIURNAL MIN FOR CONVECTION...TSRA POTENTIAL SHOULD BE MORE LIMITED. INCLUDED MVFR CONDITIONS WITH SHRA/VCTS AT KIWD...BUT JUST SHRA AT KCMX/KSAW. AFTER A FEW HRS OF PCPN...CONDITIONS SHOULD BREAK OUT TO VFR AT KIWD/KSAW...BUT MAY RETURN TO IFR UNDER CONTINUED COOL UPSLOPE EASTERLY FLOW AT KCMX. EXPECT A BREAK OUT TO VFR AT KCMX IN THE AFTN. ADDITIONAL CONVECTIVE DEVELOPMENT THIS AFTN/EVENING IS UNCERTAIN. FOR NOW...WILL PLAN FOR A MORE LIKELY DRY SCENARIO IN THE WAKE OF SHORTWAVE PASSING IN THE MORNING/EARLY AFTN. FOG MVFR CONDITIONS MAY DEVELOP THIS EVENING AT KIWD/KSAW WHILE COOL EASTERLY UPSLOPE FLOW ARGUES FOR A RETURN TO LIFR AT KCMX. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 431 PM EDT THU JUN 20 2013 FOG...AND ANY STRONGER STORMS /WITH WINDS AND/OR SMALL HAIL/ WILL BE THE MAIN HAZARDS THROUGH THE WEEKEND. OTHERWISE WINDS SHOULD REMAIN AT OR BELOW 25KTS. A TROUGH OF ACROSS LAKE SUPERIOR WILL...DEEPEN FRIDAY NIGHT...AND AGAIN SUNDAY THROUGH MONDAY. THIS WILL BE IN RESPONSE TO AN ELONGATED AREA OF LOW PRESSURE STRETCHING FROM SOUTHWESTERN CANADA THROUGH EASTERN COLORADO. EXPECT THE AREA OF LOW PRESSURE TO CONSOLIDATE ACROSS THE CENTRAL PLAINS ON SATURDAY...BEFORE SHIFTING INTO MANITOBA ON SUNDAY...AND EXITING EASTWARD THROUGH ONTARIO ON MONDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...07 AVIATION...ROLFSON MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1212 AM EDT FRI JUN 21 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 431 PM EDT THU JUN 20 2013 UPPER AIR PATTERN FEATURES DEEP TROUGHING OVER NORTHWEST CONUS WITH RIDGING DOWNSTREAM OVER NORTHERN PLAINS. SFC FRONT WITH DRIER AIR IS WORKING ACROSS DAKOTAS WITH WEAK SFC LOW OVR NCNTRL SD BTWN KBIS AND KABR. BASED ON SFC OBS AND VIS SATELLITE APPEARS WARM FRONT EXTENDS FROM SFC LOW ACROSS CNTRL MN AND INTO NORTHWEST WI. NOT MUCH OF A TEMP GRADIENT AT H85 BUT RIBBON OF HIGHER H85-H7 DWPNT ALONG WITH H85 CONVERGENCE FROM NORTHERN MN ACROSS UPR MICHIGAN IS SERVING AS FOCUS WAVE AFTER WAVE OF SCT SHRA/ISOLD TSRA. NO STRONG TSTM THOUGH AS CAPE AVAILABLE OVR THE AREA IS BLO 1000 J/KG. DEEP LAYER SHEAR IS MARGINAL AS WELL...MAYBE UP TO 30 KTS. STRONGEST CONVECTION TODAY HAVE HAD LIGHTNING BUT HAVE REALLY SHOWN LITTLE TILT OWING TO THE LIMITED INSTABILITY/SHEAR. BASED ON WV LOOP/LIGHTNING AND RUC ANALYSIS...DOES SEEM THAT THERE IS ONE WEAKER SHORTWAVE OVER NORTHWEST WI...ANOTHER NEAR THE DLH AREA...AND A STRONGER WAVE LIFTING ENE ACROSS NORTHEAST ND. EXPECT ISOLD-SCATTERED SHRA AND TSRA OVR CWA THROUGH EVENING...ESPECIALLY NORTHERN HALF...AS THESE WAVES SLIDE THROUGH ALONG THE BOUNDARY AT H85. OVERALL...LIMITED INSTABILITY SHOULD PRECLUDE STRONGER STORMS THIS EVENING OVR MUCH OF CWA. EXCEPTION MAY BE IN FAR SW VCNTY OF IWD AS MLCAPE BUILDING UP OVER 1000J/KG JUST TO SOUTHWEST OF WEST CWA AND SWRLY STORM MOTION COULD RESULT IN STRONGER STORM WITH GUSTY WINDS AND HAIL. THUS FAR NO REAL INDICATIONS OF THIS WITH UPSTREAM STORMS BUT IT IS SOMETHING TO WATCH. LATER TONIGHT...MAIN QUESTION IS WHAT WILL OCCUR WITH UPSTREAM CONVECTION. IN A NUTSHELL...APPEARS THAT IF PRIMARY AREA OF CONVECTIVE DEVELOPING THROUGH EARLY EVENING OCCURS ALONG AND EAST OF SFC LOW...850-300MB THICKNESS/ORIENTATION OF HIGHEST MUCAPE/FORWARD PROPAGATING CORFIDI VECTORS POINT TO MAIN TRACK OF SHRA/TSRA COMPLEX OR BONIFIDE MCS MAINLY STAYING SOUTH OF CWA...WOULD BE CLOSE IN THE SOUTHWEST CWA THOUGH. ON THE OTHER HAND...IF CONVECTION OVR NORTHEAST ND CONTINUES TO DRIFT ACROSS RIDGE TOP IT COULD ADVECT AND/OR SPUR ON ADDITIONAL SHRA/TSRA OVERNIGHT IN NORTHERN MN AND BASED ON 850-300MB THICKNESSES...SHRA/TSRA WOULD TRACK INTO FAR WESTERN UPR MICHIGAN 08Z-12Z. INCREASING SFC-ML CAPES AND 0-1KM SHEAR UP TO 20 KTS AND BOW-LIKE APPEARANCE FROM VARIOUS HIGHER RESOLUTION MODELS INDICATE IF THIS CONVECTION IMPACTS WESTERN CWA THERE COULD BE STRONG WIND GUSTS. WITH ALL THE CLOUD COVER AND POSSIBLE SHRA/TSRA WILL BE A WARM NIGHT WITH LOWS IN THE MID 50S EAST AND STAYING ABOVE 60 DEGREES OVER THE WEST. FOR FRIDAY...CONDITIONAL FORECAST FOR SURE. IF THE SHRA/TSRA ARE AROUND IN THE MORNING...EXPECT A GENERAL LULL LATE MORNING INTO MOST OF THE AFTN DUE TO THE SUBSIDENCE IN WAKE OF THE CONVECTION. MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 70S IF NOT REACHING 80 WITH ENOUGH SUNSHINE. AFTN INSTABILITY AND WARM FRONT/OUTFLOW IN THE VCNTY COULD LEAD TO MORE DEVELOPING SHRA/TSRA MID-LATE AFTN. LOW CHANCE POPS FOR ALL AREAS AFTER THE MAIN SHRA/TSRA CHANCES IN THE MORNING. BEST CHANCE IN THE AFTN WOULD PROBABLY BE IN THE WEST/SOUTHWEST CWA WITH BETTER SHOT OF EARLIER CLEARING/WARMER TEMPERATURES. HUMID CONDITIONS THAT HAVE DEVELOPED TODAY WILL CONTINUE THROUGH FRIDAY WITH DWPNTS STAYING AT OR ABOVE 60 IN MANY AREAS. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 431 PM EDT THU JUN 20 2013 FRI NIGHT... AFTER THE EXPECTED AREA OF SHRA/TSRA EXITS THE ERN CWA FRI EVENING... CONSENSUS OF MODELS SUGGEST PERHAPS A BREAK IN SHRA/TSRA BY LATE FRI EVENING BEFORE MORE CONVECTION DEVELOPS OVER THE UPPER MS VALLEY ALONG THE 850 MB WARM FRONT. THE FCST REFLECTS MODEL TRENDS THAT KEEP THE FOCUS FOR CONVECTIVE DEVELOPMENT WITH THE GREATEST INSTABILITY AND NOSE OF THE LLJ FARTHER SOUTH COMPARED TO EARLIER RUNS. SATURDAY AND SUNDAY... AS THE MID LEVEL RIDGE BUILDS TO THE EAST...SW FLOW PATTERN WILL ALLOW THE 850 MB WARM FRONT TO PUSH TO THE NORTH WITH WARM AND HUMID AIR BECOMING ENTRENCHED OVER THE REGION. EVEN THOUGH THE MODELS HINT AT POTENTIAL FOR A SHORTWAVE TROUGH MOVING OUT OF THE PLAINS TOWARD NW ONTARIO SAT INTO SAT EVENING...UNCERTAINTY WITH THE TIMING/POSITION OF THIS FEATURES AND THE IMPACT ON CONVECTIVE DEVELOPMENT IS HIGH. WITH THE FOCUS FOR MOISTURE/LOW LEVEL THETA-E ADVECTION SHIFTING FROM THE UPPER MS VALLEY TOWARD THE AREA...POPS INCREASE INTO THE WRN CWA BY LATE AFTERNOON AND ACROSS UPPER MICHIGAN SATURDAY NIGHT. WITH MLCAPE/MUCAPE VALUES INCREASING AT LEAST INTO THE 1K-2K J/KG RANGE...THERE WILL BE A GREATER POTENTIAL FOR STRONGER STORMS. THE MAIN HAZARD WILL BE HEAVY RAIN AS PWAT VALUES CLIMB TO 1.5 TO 1.8 INCHES (150-180 PCT OR NORMAL). WITH THE RIDGE BUILDING INTO THE AREA SUNDAY...CIN WILL INCREASE WITH 700 MB TEMPS INTO THE 10C-12C RANGE. SO...TEMPS WILL CLIMB WELL ABOVE NORMAL INTO THE 80S AND CONVECTION POTENTIAL WILL DECREASE. HOWEVER...SHRA/TSRA MAY INCREASE AGAIN BY SUNDAY NIGHT AS A STRONGER SHRTWV HELPS FLATTEN THE RIDGE AND BRINGS A WEAK SFC TROUGH INTO THE REGION. MON-THU... THERE MAY BE DRIER PERIOD WITH A WEAK MID LEVEL AND SFC RIDGE INTO THE AREA MON INTO TUE. HOWEVER...CONFIDENCE REMAINS LOW WITH THE RETROGRADING RIDGE LEADING TO A MORE ZONAL PATTERN. AS THE RIDGE BUILDS OVER THE WRN CONUS...A MORE NW FLOW PATTERN WILL STILL KEEP POTENTIAL FOR SHRA/TSRA GOING. TEMPS SHOULD TRANSITION BACK TOWARD MORE NORMAL VALUES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1212 AM EDT FRI JUN 21 2013 WILL BE A CHALLENGING FCST THRU THIS PERIOD DUE TO UNCERTAINTIES IN CONVECTION AND LOW CLOUDS/FOG. INITIALLY...AS EXPECTED...MAIN AREAS OF TSRA SO FAR TONIGHT HAVE BEEN SLIDING SE TO THE S OF THE AREA AS CONVECTION FOLLOWS 850-300MB THICKNESS PATTERN. SHRA FARTHER N THAT HAVE BEEN AFFECTING KIWD/KCMX/KSAW SHOULD DIMINISH FOR A WHILE. AT KCMX...COOL EASTERLY UPSLOPE FLOW OFF LAKE SUPERIOR INTO HIGHER DWPT AIR MASS OVER THE KEWEENAW HAS RESULTED IN LIFR CONDITIONS...AND LIFR WILL LINGER THRU THE NIGHT UNDER CONTINUED LIGHT EASTERLY WINDS. AT KSAW...WITH -SHRA DIMINISHING...FOG/MVFR CONDITIONS SHOULD PREVAIL OVERNIGHT. NOT OUT OF THE QUESTION THAT CONDITIONS COULD FALL TO IFR WITH FOG/STRATUS. DOWNSLOPE E/SE WINDS SHOULD ALLOW VFR CONDITIONS OVERNIGHT AT KIWD THOUGH MVFR WILL OCCUR WITH ANY SHRA/TSRA. LATER IN THE NIGHT...DISTURBANCE EMERGING FROM THE NRN PLAINS SHOULD SUPPORT A MORE ORGANIZED CLUSTER OF SHRA/TSRA SPREADING TOWARD THE AREA. GIVEN ARRIVAL DURING THE MORNING IN THE USUAL DIURNAL MIN FOR CONVECTION...TSRA POTENTIAL SHOULD BE MORE LIMITED. INCLUDED MVFR CONDITIONS WITH SHRA/VCTS AT KIWD...BUT JUST SHRA AT KCMX/KSAW. AFTER A FEW HRS OF PCPN...CONDITIONS SHOULD BREAK OUT TO VFR AT KIWD/KSAW...BUT MAY RETURN TO IFR UNDER CONTINUED COOL UPSLOPE EASTERLY FLOW AT KCMX. EXPECT A BREAK OUT TO VFR AT KCMX IN THE AFTN. ADDITIONAL CONVECTIVE DEVELOPMENT THIS AFTN/EVENING IS UNCERTAIN. FOR NOW...WILL PLAN FOR A MORE LIKELY DRY SCENARIO IN THE WAKE OF SHORTWAVE PASSING IN THE MORNING/EARLY AFTN. FOG MVFR CONDITIONS MAY DEVELOP THIS EVENING AT KIWD/KSAW WHILE COOL EASTERLY UPSLOPE FLOW ARGUES FOR A RETURN TO LIFR AT KCMX. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 431 PM EDT THU JUN 20 2013 FOG...AND ANY STRONGER STORMS /WITH WINDS AND/OR SMALL HAIL/ WILL BE THE MAIN HAZARDS THROUGH THE WEEKEND. OTHERWISE WINDS SHOULD REMAIN AT OR BELOW 25KTS. A TROUGH OF ACROSS LAKE SUPERIOR WILL...DEEPEN FRIDAY NIGHT...AND AGAIN SUNDAY THROUGH MONDAY. THIS WILL BE IN RESPONSE TO AN ELONGATED AREA OF LOW PRESSURE STRETCHING FROM SOUTHWESTERN CANADA THROUGH EASTERN COLORADO. EXPECT THE AREA OF LOW PRESSURE TO CONSOLIDATE ACROSS THE CENTRAL PLAINS ON SATURDAY...BEFORE SHIFTING INTO MANITOBA ON SUNDAY...AND EXITING EASTWARD THROUGH ONTARIO ON MONDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...JLB AVIATION...ROLFSON MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
320 AM MDT FRI JUN 21 2013 .SHORT TERM...VALID FOR TDY AND SAT... SEVERAL OPPORTUNITIES FOR SHOWERS AND STORMS WILL EXIST DURING THE NEXT 36 HOURS AS THE UPPER-LEVEL TROUGH CENTERED OVER ID AT 09 UTC HEADS EAST. WHILE THE RESERVOIR OF STRONGEST INSTABILITY WILL STAY ANCHORED DOWNSTREAM IN THE DAKOTAS...ENOUGH INGREDIENTS WILL EXIST FOR SOME RISK OF SEVERE STORMS ACROSS PARTS OF OUR AREA TOO. EARLY THIS MORNING...ELEVATED CONVECTION FED ON A 30+ KT LOW-LEVEL JET HAS BEEN FORMING EAST OF BILLINGS SINCE ABOUT 06 UTC. INFRARED SATELLITE IMAGES SUGGEST ANOTHER SUBTLE SHORT WAVE IMPULSE LOCATED OVER CENTRAL AND NORTHEAST WY WILL MOVE INTO SOUTHEASTERN MT BY 12 UTC. THAT LENDS CREDENCE TO THE LAST SEVERAL HRRR RUNS AND SEVERAL OTHER HIGH-RESOLUTION...CONVECTION-ALLOWING MODEL SIMULATIONS FROM 00 UTC IN SHOWING ROBUST STORMS DEVELOPING BY MORNING FROM BROADUS AND EKALAKA TOWARD BAKER. FORECAST SOUNDINGS AND RAP ANALYSES SHOW MUCAPE ON THE ORDER OF 1000 J/KG...MID LEVEL LAPSE RATES OF 7 C/KM OR BETTER...AND EFFECTIVE SHEAR OF 60 KT IN SOUTHEASTERN MT DURING THE MORNING. THUS...SOME SEVERE HAIL IS POSSIBLE...AND WE ACTUALLY DECIDED TO MENTION THE RISK OF SEVERE STORMS EXPLICITLY WITHIN THE FORECAST DURING THE MORNING HOURS AT BROADUS...BAKER..AND EKALAKA. LATER TODAY...WE KEPT THE MENTION OF SEVERE STORMS IN SOUTHEASTERN MT...AND EXPANDED IT BACK WEST AS FAR AS SHERIDAN AND LODGE GRASS. THE WESTWARD EXTENSION OF THE SEVERE RISK WAS DONE LARGELY TO GIVE DUE RESPECT TO CALIBRATED SEVERE THUNDERSTORM PROBABILITIES OFF OF THE 21 UTC SREF...WHICH ARE FOCUSED IN THE SHERIDAN AREA BY THE 21 TO 00 UTC TIME FRAME. WE HAVE TO ADMIT THOUGH THAT CONFIDENCE WITH THIS EVENT REMAINS BELOW-NORMAL...AND EARLY-DAY CONVECTION WILL BE A PLAYER IN HOW THINGS EVOLVE LATER TOO. IF IT IS PERSISTENT...THE BOUNDARY LAYER MAY NOT DESTABILIZE ENOUGH FOR SURFACE-BASED STORMS BY LATE AFTERNOON. ON THE OTHER HAND...ENOUGH ELEVATED INSTABILITY EXISTS TO SUPPORT SEVERE HAIL EVEN IF CONVECTION JUST CONTINUES TO REGENERATE OVER SOUTHEASTERN MT THROUGH THE DAY. FINALLY...WE ALSO INCREASED POPS OVER SOUTH CENTRAL MT FROM LIVINGSTON TO BIG TIMBER AND HARLOWTON THIS AFTERNOON TOO WHERE A DIFFERENT WAVE WILL ALLOW AT LEAST WEAK AND SCATTERED SHOWERS AND STORMS TO FORM. TONIGHT...ONCE EVENING CONVECTION WINDS DOWN AND/OR MOVES OFF INTO THE DAKOTAS...WE MIGHT HAVE A BIT OF A BREAK IN PRECIPITATION. THE 00 UTC ECMWF SUGGESTS ANOTHER WEAK SHORT WAVE TROUGH WILL GENERATE MORE SHOWERS OR STORMS OVER SOUTHEASTERN MT TOWARD DAYBREAK THOUGH AND THAT IS A GOOD EXAMPLE OF WHY CHANCE POPS REMAIN NECESSARY FOR MOST AREAS IN THE 06 TO 12 UTC TIME FRAME. SAT...THE 500-HPA TROUGH AXIS IS EXPECTED TO SWEEP ACROSS THE AREA DURING THE AFTERNOON AND EVENING. STRONG QG-FORCING CONCOMITANT TO THAT TROUGH AND INSTABILITY AHEAD OF THE 500-HPA COLD POOL WILL BE SUFFICIENT TO GENERATE A HEALTHY BATCH OF CONVECTION. WE INCREASED POPS INTO THE CATEGORICAL /80 PERCENT/ RANGE ALONG AND EAST OF THE BILLINGS TO SHERIDAN LINE TO REFLECT THE LIKELIHOOD FOR AT LEAST A PERIOD OF STORMS AHEAD OF THE TROUGH. THAT MOVE HAS STRONG SUPPORT FROM THE 00 UTC MULTI-MODEL CONSENSUS. WE WILL ACTUALLY HAVE A LOW RISK OF SEVERE STORMS AGAIN TOO...ESPECIALLY IF STORMS ARE ABLE TO GET FAR ENOUGH AHEAD OF THE MID-LEVEL TROUGH AXIS...WHERE THEY MAY HAVE ACCESS TO STRONGER EFFECTIVE SHEAR. SCHULTZ .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... THE EARLY PART OF THE EXTENDED FORECAST LOOKS UNSETTLED WITH A DRYING AND WARMING TREND FROM WEDNESDAY ONWARD. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE MONDAY AND TUESDAY AS SOUTHWEST FLOW OPENS UP AGAIN AND PROVIDES SEVERAL SHORTWAVES AND DEEPENING MOISTURE. RAISED POPS FOR TUESDAY AS MODELS HAVE SLOWED DOWN A BIT ON BUILDING THE RIDGE NOW UNTIL WEDNESDAY. MODELS WERE CONSISTENT IN BUILDING A STRONG RIDGE INTO THE NORTHERN ROCKIES WEDNESDAY INTO FRIDAY. THE GFS ACTUALLY HAS A 594DM HEIGHT LINE WORKING INTO SOUTHWEST MONTANA FRIDAY. THAT WOULD LEAD TO A WARM AND MAINLY DRY FORECAST. WILL HAVE TO WATCH FOR RIDGE RIDING SHORTWAVES FOR ISOLATED CONVECTION...BUT AT THIS TIME THE MODELS WERE DRY WITH THE MID LEVEL FLOW. TWH && .AVIATION... SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP EAST OF A ROUNDUP TO BILLINGS LINE EARLY THIS MORNING. SOME STORMS COULD CONTAIN HEAVY RAIN AND SMALL HAIL OVER SOUTHEAST MONTANA. THUNDERSTORM DEVELOPMENT WILL SPREAD INTO WESTERN SECTIONS BY LATE MORNING. LOCAL MVFR CONDITIONS CAN BE EXPECTED IN THE STRONGER STORMS. THUNDERSTORMS CHANCES WILL CONTINUE TONIGHT BUT THE MOST LIKELY LOCATION FOR ADDITIONAL RAINFALL WILL BE OVER THE SOUTHEAST. TWH && .PRELIMINARY POINT TEMP/POPS... TDY SAT SUN MON TUE WED THU ------------------------------------------------------- BIL 073 052/068 049/078 054/083 058/084 057/083 057/084 5/T 38/T 61/B 11/B 23/T 31/B 10/U LVM 069 043/066 044/079 046/083 051/083 052/086 051/087 6/T 57/T 51/B 12/T 23/T 31/B 11/U HDN 075 051/070 048/078 052/083 054/085 056/084 058/085 5/T 38/T 61/B 11/B 22/T 21/B 10/U MLS 076 056/072 053/080 056/084 059/085 059/086 057/086 6/T 58/T 82/T 12/T 22/T 21/B 11/U 4BQ 075 054/071 051/079 054/085 057/086 057/087 058/088 7/T 68/T 82/T 12/T 22/T 21/U 11/U BHK 074 055/069 052/076 054/085 059/084 060/086 057/082 7/T 67/T 82/T 12/T 33/T 21/B 11/U SHR 075 050/069 045/076 049/082 052/084 051/085 052/084 5/T 48/T 61/B 11/B 22/T 21/B 00/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
204 AM CDT FRI JUN 21 2013 .DISCUSSION... HAVE REMOVED POPS FROM THE NORTHERN CWA FOR THE OVERNIGHT HOURS. DID KEEP SOUTHERN CWA DRY FOR NOW...BUT WILL NEED TO MONITOR TRENDS OF CONVECTION IN SOUTH CENTRAL NEB/NORTH CENTRAL KS. SPC MESOANALYSIS INDICATES CONVECTION IS MOVING INTO INCREASING MUCIN AS IT PROGRESSES EASTWARD...BUT HAVE LOW CONFIDENCE IN FORECAST...AS MODELS HAVE NOT CAPTURED ONGOING CONVECTION WELL ACROSS THE CENTRAL US. THE AIRMASS DOES ACTUALLY BECOME MORE UNSTABLE FURTHER EASTWARD INTO EASTERN NEB...SO IF CONVECTION SURVIVES TO THE WESTERN CWA...IT WOULD HAVE A GOOD SHOT AT SURVIVING INTO THE AREA. MAYES && .AVIATION... 06Z TAFS FOR KOMA...KLNK...AND KOFK. VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE...WITH SOME MID-LEVEL CLOUDS POSSIBLE THIS MORNING. HAVE INCLUDED A WIND SHEAR MENTION AT ALL SITES WITH THE POTENTIAL FOR WINDS TO DECOUPLE IN THE OVERNIGHT/EARLY MORNING HOURS...BUT EXPECT WIND GUSTS TO PICK UP QUICKLY AGAIN BY MID-MORNING. MAYES && .PREV DISCUSSION... /ISSUED 304 PM CDT THU JUN 20 2013/ SHORT TERM...TONIGHT THROUGH FRIDAY. THE PRIMARY FORECAST CONCERNS IN THIS PERIOD ARE STILL THE POTENTIAL FOR TSTMS AND TEMPERATURES. UPPER AIR CHARTS FROM THIS MORNING SHOWED THE FOLLOWING. 80 KNOT WINDS AT 300 MB STRETCHED FROM NORTHERN CALIFORNIA INTO WYOMING. A LONGWAVE TROUGH WAS OVER THE WESTERN U.S. WITH A WEAK RIDGE OVER THE PLAINS. 12 HOUR HEIGHT FALLS OF 110 METERS WERE NOTED AT 500 MB OVER MONTANA. THERMAL RIDGE AT 700 MB EXTENDED FROM MEXICO NORTHWARD INTO EASTERN COLORADO. THE KOAX 12Z SOUNDING SHOWED A 700 MB TEMP OF 8 C AND A DEWPOINT OF 4 C. MOIST BAND AT 700 MB EXTENDED FROM WEST TEXAS UP INTO THE DAKOTAS. THIS MOISTURE WILL BE ONE OF THE THINGS TO MONITOR IN REGARDS TO CONVECTIVE COVERAGE THE NEXT SEVERAL DAYS. SURFACE ANALYSIS EARLY THIS AFTN SHOWED ONE LOW PRESSURE CENTER UP ALONG THE NORTH DAKOTA/SOUTH DAKOTA BORDER AND ANOTHER IN SOUTHEAST COLORADO. A COLD FRONT STRETCHED FROM THE LOW OVER THE DAKOTAS DOWN INTO WESTERN NEBRASKA AND NORTHEAST COLORADO. GUSTY SOUTH WINDS WERE IN PLACE ACROSS THE FORECAST AREA WITH DEWPOINTS IN THE UPPER 60S TO AROUND 70. THIS EVENING...WINDS SHOULD RELAX A LITTLE. THE ATMOSPHERE WILL BE VERY UNSTABLE...WITH CAPE VALUES IN EXCESS OF 3000 J/KG AND 0-6 KM SHEAR VALUES OF 20-30 KNOTS. HOWEVER...LIKE YESTERDAY...WE DO NOT HAVE MUCH OF A FOCUSING MECHANISM FOR STORM DEVELOPMENT. MOST RECENT HRRR AND 13 KM RAP MODELS SUGGEST SOME STORMS ARE POSSIBLE ALONG AND EAST OF THE MID LEVEL CAP...AS WELL AS ACROSS PARTS OF NORTHEAST NEBRASKA. 4 KM WRF-NMM RUN FROM 12Z IS MUCH MORE BULLISH WITH STORM DEVELOPMENT THIS EVENING FROM THE DAKOTAS/MINNESOTA DOWN INTO PARTS OF NORTHERN AND WESTERN NEBRASKA. ALTHOUGH THAT IS ONE POSSIBILITY...TENDED TO SHY AWAY FROM THAT SCENARIO. BOTH THE 12Z NAM AND GFS ALSO APPEARED TOO WET TONIGHT IN OUR AREA. FRIDAY...KEPT THUNDERSTORM CHANCES BELOW 15 PERCENT. TEMPERATURES SHOULD TOP OUT IN THE LOWER OR MID 90S WITH MAX HEAT INDICES UP NEAR 100. WINDS SHOULD INCREASE INTO THE BREEZY OR WINDY CATEGORY AGAIN. MILLER LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. THE BEST CHANCES FOR THUNDERSTORMS IN THIS PERIOD APPEAR TO BE FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. A GENERAL BLEND/CONSENSUS OF THE 12Z MODELS IS THAT A FRONTAL BOUNDARY SHOULD PUSH INTO OUR AREA FROM THE NORTHWEST SATURDAY NIGHT...THEN LINGER IN THE AREA SUNDAY AND SUNDAY NIGHT. INSTABILITY AND SHEAR APPEAR THAT THEY WOULD BE ADEQUATE FOR SOME ORGANIZED SEVERE WEATHER. THE TENDENCY FOR A TROUGH AT 500 MB OVER THE WESTERN U.S. SHOULD CONTINUE INTO EARLY NEXT WEEK. AFTER THAT...A MORE SUMMER-LIKE FLOW PATTERN IS FORECAST TO DEVELOP DUE TO RETROGRESSION. TROUGH AXIS WILL SHIFT BACK TO AROUND 140 DEGS WEST LONGITUDE WHILE A 500 MB RIDGE STRENGTHENS OVER THE DESERT SOUTHWEST AND SOUTHERN ROCKIES. KEPT A MAINLY DRY FORECAST GOING FOR MONDAY INTO THURSDAY...DUE TO LOW CONFIDENCE. KEPT HIGHS MAINLY IN THE UPPER 80S TO MID 90S WITH LOWS IN THE UPPER 60S TO MID 70S. MILLER && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1144 PM MDT THU JUN 20 2013 .AVIATION... 06Z TAF CYCLE ONLY AN ISOLATED TSTM REMAINS NEAR KROW ATTM...AND WILL BE MOVING OUT OF THE AREA IN THE NEXT HOUR OR SO. ADDITIONALLY...SMOKE FROM THE WILDFIRE WEST OF KTCS MAY IMPACT AREAS NEAR AND SE OF KONM TONIGHT. OTHERWISE...DRYLINE HAS RETREATED FARTHER WEST THAN ANTICIPATED EARLIER...AND HAS NOW PUSHED THROUGH KSAF. DO NOT EXPECT A CANYON WIND INTO ABQ BUT CAN EXPECT SOME EAST-SE WIND GUSTS TO 25KT FOR ANOTHER HOUR OR TWO AT KSAF. STRONGER WINDS CAN BE EXPECTED ACROSS THE PLAINS WHERE GUSTS BETWEEN 35 AND 40KTS WILL BE POSSIBLE THROUGH 09-10Z. STRONG SW WINDS WILL RAMP BACK UP ACROSS CENTRAL AND WESTERN NM ON FRIDAY...WITH GUSTS NEAR 35KTS. A FEW SHOWERS OR TSTMS WILL AGAIN BE POSSIBLE FRIDAY AFTERNOON AND EVENING ACROSS THE SE PLAINS. ERRATIC WIND GUSTS AND SMALL HAIL WOULD BE THE MAIN THREATS. TIMING AND COVERAGE IS QUESTIONABLE... THUS ONLY INSERTED A VCTS INTO KTCC AND KROW TAFS ATTM. AFTER THE CONVECTION ENDS FRIDAY EVENING...ANOTHER ROUND OF STRONG SOUTHERLY WINDS WILL IMPACT EASTERN NM. SE WINDS ASSOCIATED WITH THE DRYLINE MAY REACH KSAF LATE FRIDAY NIGHT. 34 && .PREV DISCUSSION...328 PM MDT THU JUN 20 2013... SATELLITE AND SURFACE MOISTURE ANALYSIS SHOW THE MOIST AXIS FOCUSED FROM NORTHERN MEXICO ACROSS SE NEW MEXICO INTO WEST TX. THE LATEST RADAR TRENDS INDICATE SHOWER AND STORM COVERAGE INCREASING IN THIS AREA...WHICH COINCIDES WELL WITH THE 17Z HRRR AND RIDGE OF HIGHEST THETA-E VALUES FROM THE NAM AND GFS. FARTHER WEST THE FOCUS FOR DRY AND BREEZY CONDITIONS COINCIDES WITH A MID/UPPER LEVEL DRY SLOT STRETCHING FROM THE BAJA INTO NORTH CENTRAL NM. THE DEFINITION OF PERSISTENCE WILL HOLD VERY TRUE ACROSS OUR AREA AS THERE WILL BE VERY LITTLE CHANGE TO THE PATTERN CONFIGURATION THRU TUESDAY OF NEXT WEEK. EXPECT VERY DRY...BREEZY...AND HOT CONDITIONS FOR CENTRAL AND WESTERN NM WITH A FEW STORMS FOCUSED OVER THE SE AND EAST CENTRAL PLAINS. MAX AND MIN TEMPS WILL BE NEARLY THE SAME EVERY PERIOD AND ABOVE NORMAL HOWEVER NO RECORDS ARE EXPECTED. UNFORTUNATELY...EVEN HOTTER CONDITIONS BUT WITH LESS WIND WILL OCCUR FOR THE WEDNESDAY THRU SATURDAY PERIOD OF NEXT WEEK. THIS MAY BE THE PEAK FOR THE SUMMER WITH A 596 TO 599DM H5 RIDGE CENTERED DIRECTLY OVER NORTHERN NM AND SOUTHERN CO. THE ECMWF AND GFS THEN SHOW THE RIDGE WOBBLING WESTWARD INTO NORTHERN AZ ALLOWING A MOIST BACK DOOR FRONT TO SLIDE INTO THE EAST. THIS WOULD PROVIDE FOR ANOTHER UPTICK IN STORM COVERAGE HOWEVER CONFIDENCE ON THIS PATTERN IS VERY LOW AS CONSISTENCY IS POOR FROM MODEL RUN TO RUN. GUYER .FIRE WEATHER... DRY LINE HAS BEEN DRIVEN BACK TO A LINE FROM JUST EAST OF TUCUMCARI TO NEAR OR JUST W OF DUNKEN...PRETTY MAJOR EROSION CONSIDERING HOW FAR WEST IT GOT EARLY THIS MORNING. SHOULD WAFT BACK W TONIGHT...BUT NOT QUITE AS FAR W AS EARLY TODAY. POOR RH RECOVERIES TONIGHT WEST OF DRY LINE...BASICALLY W OF A RATON TO RUIDOSO LINE. GOOD TO EXCELLENT RECOVERIES TO E OF THE DRY LINE. SOME SHOWERS AND STORMS OF WET VARIETY INTO THE EVE NEAR TO E OF TUCUMCARI TO RUIDOSO LINE. RED FLAG CONDITIONS OF THIS AFTN SHOULD DROP OUT BETWEEN 7 AND 9 PM. AT LEAST THRU NEXT TUE LOOKING FOR CURRENT PATTERN TO NOT CHANGE MUCH...GENERALLY A PATTERN OF A FEW TO SCT SHOWERS AND STORMS...MOSTLY WET...GENERALLY NEAR AND EAST OF A TUCUMCARI TO RUIDOSO LINE. MAY ON A COUPLE OF OCCASIONS SEE THAT LINE SHIFT UP TO 75 OR 100 MILES FARTHER E OR W DURING THIS PERIOD. SET UP WILL BE A PACIFIC NW TROUGH AND AN UPPER HIGH GENERALLY CENTERED BETWEEN CENTRAL TX AND FAR N MEXICO. VERY DRY AIR WILL KEEP COMING ACROSS NW HALF TO TWO THIRDS OF NM AROUND THE HIGH...RESULTING IN EXTREMELY LOW RH MINIMUMS AND MANY HOURS OF SINGLE DIGIT HUMIDITIES TO CONTINUE AS WELL FROM THE CENTRAL MTN CHAIN WEST TO THE AZ BORDER. THOUGH DRY THE AIRMASS WILL BE UNSTABLE WITH DAYTIME HEATING AND ABOVE NORMAL TEMPERATURES. HAINES VALUES OF 6 AND EVEN SOME LOCALIZED SUPER HAINES WILL SHOW UP LATE IN THE DAY FOR AT LEAST THE NEXT 3 TO 4 DAYS. AS FOR HIGHLIGHTS...AM CONTINUING THE RED FLAG WARNING INTO THIS EVE AS BEFORE...AS MORE AREAS THAN NOT ARE VERY NEAR OR A LITTLE OVER CRITICAL THRESHOLDS. UPGRADED EXISTING WATCH FOR FRI TO RED FLAG WARNING AND ADDED FIRE ZONE 104...MAINLY WEST AND CENTRAL PORTIONS...LARGELY BASED ON HOW FAR E DRYLINE PROGRESSED TODAY. SEE NO REASON FOR IT NOT TO GET AT LEAST AS FAR E AS CLAYTON FRI AFTN...MAIN REASON THAT ZONE ADDED. STILL BELIEVE MOST OF LOWER TERRAIN OF 101 WILL BE MARGINAL AT MOST FOR CRITICAL CONDITIONS FRI AFTN...BUT HIGHER TERRAIN THERE SHOULD DO BETTER AND WITH DEGREE OF DRYNESS AND HEAT FELT IT BEST TO UPGRADE THAT ZONE ALONG WITH THE REST. ALSO HOISTED FIRE WX WATCH FOR SAT AFTN AND EARLY EVE FOR 102 THROUGH 104...107 AND WESTERN PART OF 108. 43 && .ABQ WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES...NMZ102>104-107-108. RED FLAG WARNING FROM 1 PM TO 8 PM MDT FRIDAY FOR THE FOLLOWING ZONES...NMZ101>105. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
139 AM EDT FRI JUN 21 2013 .SYNOPSIS... TODAY IS THE OFFICIAL START OF SUMMER. HIGH PRESSURE WILL RETREAT AS A LINGERING FRONT OFFSHORE NUDGES BACK TO THE WEST THROUGH THE WEEKEND...BRINGING AN INCREASING RISK FOR SHOWERS AND THUNDERSTORMS. TYPICAL SUMMERTIME WEATHER IS EXPECTED NEXT WEEK WITH BERMUDA HIGH PRESSURE AND THE PIEDMONT TROUGH BECOMING THE DOMINANT SURFACE FEATURES. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 1045 PM THURSDAY...MODEL CONSENSUS CONTINUES WITH THE STALLED FRONT OFFSHORE FROM THE CAROLINAS...DRIFTING WESTWARD TOWARD THE CAROLINA COASTLINES OVERNIGHT. IT MAY REACH THE OUTER WATERS OF THE COASTAL WATERS WELL AFTER DAYBREAK FRIDAY. THE STUBBORN NOSE OF HIGH PRESSURE RIDGING SOUTHWEST FROM ITS 1030 MB CENTER...WILL HOLD ITS GROUND OVERNIGHT INTO FRIDAY. DRIER AIR WITH DEWPOINTS IN THE 50S ACROSS THE NORTHERN PORTIONS OF THE ILM CWA...RISING INTO THE 60S ACROSS THE SOUTHERN PORTIONS OF THE ILM CWA. DEWPOINTS WILL ONLY MODERATE SOME TONIGHT AS THE SFC HIGH CONTINUES TO WEDGE SOUTHWEST ACROSS THE AREA. MAINLY CIRRUS TO AFFECT THE ILM CWA TONIGHT...WITH MID TO HIGH LEVEL CLOUDINESS ASSOCIATED WITH THE STALLED FRONT POSSIBLY REACHING THE COASTAL COUNTIES DURING THE PRE-DAWN FRI HOURS. PCPN ASSOCIATED WITH THE ADVANCING WESTWARD MOVING FRONT...WILL BE HIGHLIGHTED IN THE LOW CHANCE CATEGORY BY 6 AM FRI...MAINLY OVER THE ADJACENT COASTAL WATERS. FEW TWEAKS TO THE CURRENT MIN TEMP FORECAST CLOSER TO THE COAST...OTHERWISE REMAINDER OF THE TEMP FCST LOOKS AOK. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...DRY HIGH PRESSURE NOSING IN FROM THE NORTHEAST INTO THE CENTRAL CAROLINAS WILL GET PUSHED FARTHER INLAND AS THE LINGERING FRONT TO OUR SOUTHEAST MOVES BACK TOWARD THE COAST. A VERY TIGHT GRADIENT WILL EXIST BETWEEN THE VERY DRY AIR TO THE NORTHWEST AND THE MOISTURE LADEN AIR MASS TO THE SOUTHEAST. PCP WATER VALUES WILL BE DOWN TO A HALF INCH IN CENTRAL NC BUT WILL BE UP TO 2 INCHES ALONG COASTAL SC. THIS LINGERING BOUNDARY WILL RETURN TO THE COAST AS IT GRADUALLY WEAKENS THROUGH THE WEEKEND. INITIALLY IT WILL SPREAD CLOUDS OVER THE COASTAL AREAS BUT THROUGH THE DAY ON FRI THE CLOUDS WILL SPREAD FURTHER INLAND. LOOKS LIKE THE BEST MOISTURE RETURN AND CONVERGENCE WILL BE CLOSER TO THE SC COAST ON FRI AS WINDS SHIFT TO THE E-SE THROUGH DAY. BY SATURDAY THE BOUNDARY WILL MOVE FAR ENOUGH INLAND WITH WINDS COMING AROUND TO THE EAST TO SOUTHEAST OVER MOST OF AREA WITH DEEPER MOISTURE MAKING ITS WAY IN. DEEP MOISTURE AND WEAK STEERING FLOW COULD POSE A FLOOD THREAT BUT MOST MODEL QPF HAS BACKED OFF OF TOTAL AMOUNTS. SOUNDINGS AND MOISTURE PROFILES SUGGEST A HUGE INCREASE IN MOISTURE THROUGH THE MID TO UPPER LAYERS ESPECIALLY AND MAY SEE MUCH MORE IN THE WAY OF CLOUDS THAN PCP. FLOODING MAY BE VERY LOCALIZED. TEMPERATURES WILL REMAIN BELOW CLIMO THROUGH THE PERIOD WITH CLOUDS AND PCP HOLDING THEM DOWN ALONG THE COAST AND SLIGHTLY COOLER AIR MASS INLAND. MAX TEMPS WILL REMAIN IN THE LOW TO MID 80S MOST PLACES. LOWS WILL RUN A LITTLE CLOSER TO CLIMO...THOUGH STILL UNDER. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 300 PM THURSDAY...BIGGEST QUESTION MARK DURING THE LONG TERM CONTINUES TO BE HOW A DECAYING COASTAL TROUGH/REMNANT FRONT...WHICH WILL LIFT BACK NORTH ACROSS THE AREA SUNDAY...WILL IMPACT THE AREA. WHILE ECMWF CONTINUES TO BE THE DRIEST OF THE MODELS...IT HAS TRENDED WETTER...AND IT NOW LOOKS LIKE SUNDAY WILL BE PRETTY CLOUDY WITH SHOWERS/TSTMS...ESPECIALLY THE EASTERN HALF OF THE AREA. STILL MUCH UNCERTAINTY THOUGH SINCE THE BOUNDARY IS WEAKENING...AND THE ANTECEDENT AIRMASS LOOKS QUITE DRY. BUT WILL INCREASE POP TO MEDIUM-CHC AS THE BOUNDARY LIFTS NORTH INTO AN AIRMASS WITH PWATS RISING TO 1.75 INCHES. BEHIND THIS BOUNDARY...MORE TYPICAL SUMMERTIME PATTERN SETS UP FOR THE REMAINDER OF THE EXTENDED WITH BERMUDA HIGH ANCHORING OVER THE WESTERN ATLANTIC OCEAN AND MID-LEVEL RIDGING BULGING ACROSS THE SOUTHERN TIER. THIS WILL PUMP CONSIDERABLE MOISTURE INTO THE REGION AND WILL SUPPORT AT LEAST SCATTERED SEA BREEZE AND PIEDMONT TROUGH CONVECTION EACH DAY NEXT WEEK. BY WED/THU...LARGE UPPER RIDGE EXPANDS ACROSS THE SOUTHWEST...WEAKENING THE RIDGE IN THE EAST...AND MORE WIDESPREAD CONVECTION IS POSSIBLE DURING THAT TIME. TEMPS WILL RISE SLOWLY THROUGH THE PERIOD...WITH SUNDAY BEING THE COOLEST DAY WITH TEMPS SLIGHTLY BELOW CLIMO. A WARMING TREND COMMENCES THEREAFTER AS TEMPS RISE TO ABOVE NORMAL MUCH OF NEXT WEEK. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...EXPECT VFR TO CONTINUE THROUGH THE VALID PERIOD WITH THE EXCEPTION OF POTENTIAL MVFR CEILINGS 09-13Z AT THE COAST. VFR CONTINUES ACROSS THE AREA WITH NE WINDS AOB 8 KTS. GIVEN LATEST ANALYSIS WILL CONTINUE TO CARRY THE POTENTIAL FOR MORNING STRATUS ALONG THE COAST CREATING MVFR/POSSIBLE BRIEF IFR. OTHERWISE VFR WILL PREVAIL WITH INCREASING CLOUDS THROUGHOUT THE DAY AS A FRONT OFF THE CAROLINA COAST BEGINS TO MOVE WEST. ISOLATED TO SCATTERED SHOWERS/ THUNDERSTORMS THROUGHOUT THE DAY...ESPECIALLY ALONG THE COAST...WITH EAST- NORTHEAST WINDS AOB 10 KTS. INTO THE EVENING HOURS...VFR WILL PREVAIL WITH BKN/OVC SKIES AND LIGHT NORTHEAST WINDS. EXTENDED OUTLOOK...MODERATE CHANCE OF SHOWERS THROUGH TUESDAY AS A STALLED FRONT LINGERS NEAR THE COAST. BEST CHANCE FOR PRECIP WILL BE IN THE AFTERNOON...WITH LOCAL MVFR/IFR CONDITIONS POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM THURSDAY...WEDGE OF HIGH PRESSURE ACROSS THE INLAND CAROLINAS...AND THE STALLED FRONT OFFSHORE AND PARALLEL TO THE CAROLINA COASTLINES...WILL COMBINE TO PRODUCE A NE-E WIND 15 TO 20 KT FOR MUCH OF THE OVERNIGHT PERIOD...POSSIBLY DIMINISHING TO AROUND 15 KT BY DAYBREAK FRIDAY. DURING THE PRE-DAWN FRI HOURS...THE STALLED FRONT WILL BEGIN TO ADVANCE WESTWARD AND POSSIBLY REACH THE OUTER WATERS OF THE COASTAL WATERS WELL AFTER DAYBREAK FRI. LATEST HRRR SFC WIND OUTPUT FOLLOWED CLOSELY. FIVE TO 6 SECOND AVERAGE PERIOD WIND DRIVEN WAVES WILL DOMINATE SIGNIFICANT SEAS. EXPECT 3 TO 5 FOOT SIG SEA HEIGHTS FOR THE REMAINDER OF THE OVERNIGHT...WITH 2 TO 4 FT SOUTH OF CAPE FEAR TO MYRTLE BEACH WHICH LIES IN A PROTECTIVE SHADOW RESULTING FROM NE-E WIND DRIVEN WAVES MOVING ACROSS FRYING PAN SHOALS. WILL CONTINUE THE BORDERLINE SCEC THROUGH 6 AM. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...NORTHEAST WINDS WILL DIMINISH TO UNDER 15 KTS FRI AS LINGERING SURFACE BOUNDARY EAST TO SOUTHEAST OF THE WATERS MOVES CLOSER AND SURFACE HIGH RETREATS A LITTLE FARTHER INLAND. AS WINDS LIGHTEN THEY WILL VEER AROUND BECOMING MORE EASTERLY AND EVENTUALLY SOUTHEAST AS BOUNDARY SHIFTS CLOSER TO THE COAST. ONCE THE WEAKENING FRONT/TROUGH MOVES INLAND BY SATURDAY THE WINDS WILL BECOME MORE SOUTHEASTERLY. EXPECT A SPIKE IN WINDS AND A GREATER E-SE FLOW CLOSE TO THE SHORE EACH AFTERNOON. SEAS 3 TO 4 FT FRI DECREASE TO 2 TO 3 FT ON SAT AND UNDER 3 FT SAT NIGHT AS WINDS LIGHTEN WITH A SLIGHTLY LONGER PERIOD UP TO 10 SEC EAST-SOUTHEASTERLY SWELL. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 PM THURSDAY...LIGHT SE WINDS LESS THAN 10 KTS SUNDAY WILL GRADUALLY VEER TO THE SOUTHWEST BY MONDAY AND PERSIST THROUGH THE REMAINDER OF THE PERIOD AS BERMUDA HIGH PRESSURE ANCHORS OFFSHORE. WHILE WIND SPEEDS WILL INCREASE AS THEY TURN TO THE SW...THEY WILL REMAIN ONLY 10-15 KTS MONDAY AND TUESDAY. WHILE A WEAK WIND WAVE CONTRIBUTION WILL EXIST WITHIN THE WAVE SPECTRUM...SEAS BECOME INCREASINGLY SWELL-DOMINATED THROUGH THE PERIOD THANKS TO THE PERSISTENT FETCH AROUND BERMUDA HIGH. WAVE AMPLITUDES WILL BE 1-3 FT SUNDAY...GROWING TO 2-4 FT MONDAY AND TUESDAY. && .TIDES/COASTAL FLOODING... AS OF 300 PM THURSDAY...TIDAL RANGES ARE EXPANDING AS THE FULL MOON APPROACHES THIS WEEKEND. SEVERAL HIGH TIDES THIS WEEKEND MAY REACH MINOR COASTAL FLOODING CRITERIA ALONG THE CAPE FEAR RIVER AT DOWNTOWN WILMINGTON. THIS IS NOT EXPECTED TO BE A MAJOR EVENT...BUT ANYTIME THE RIVER RISES TO MORE THAN 5.50 FEET ABOVE MLLW PROBLEMS DEVELOP ALONG BATTLESHIP ROAD AND NEAR THE U.S.S. NORTH CAROLINA BATTLESHIP MEMORIAL. THIS EVENING`S HIGH TIDE SHOULD FALL SHORT OF 5.50 FEET...BUT HIGH TIDES SATURDAY AND SUNDAY EVENINGS HAVE MUCH BETTER POTENTIAL TO PRODUCE MINOR FLOODING. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH SHORT TERM...RGZ LONG TERM...JDW AVIATION...SGL/RJD TIDES/COASTAL FLOODING...TRA
AREA FORECAST DISCUSSION
NWS NORMAN OK
357 AM CDT FRI JUN 21 2013 .DISCUSSION... HOT AND MAINLY RAINFREE WEATHER WILL BE THE MAIN STORY OVER THE NEXT SEVERAL DAYS. THIS MORNING...A FEW HIGH BASED THUNDERSTORMS WILL CONTINUE OVER FAR NORTHWEST OKLAHOMA...MAINLY NORTHWEST OF A CHEYENNE TO ALVA LINE. NO SEVERE STORMS ARE EXPECTED. KEPT 10-30 PERCENT...ISOLATED TO SCATTERED COVERAGE MENTION THIS MORNING IN THESE AREAS...THOUGH THESE STORMS MAY DISSIPATE QUICKLY OVER THE NEXT HOUR OR TWO. THIS AFTERNOON AND EARLY THIS EVENING...GENERALLY EXPECT ANOTHER HOT AND DRY DAY. SOME LATEST HRRR GUIDANCE HINTED THAT ISOLATED TO SCATTERED STORMS MAY DEVELOP NEAR A VERNON TO LAWTON TO OKLAHOMA CITY LINE BETWEEN 1 AND 5 PM...WEAKENING TOWARDS SUNSET. THE ONLY NOTICEABLE TRIGGER FOR LIFT WOULD BE A WEAK SHORT WAVE/POSSIBLE MCV CURRENTLY NEAR LUBBOCK TEXAS. CHANCES OF STORMS DEVELOPING SEEM TOO LOW TO MENTION AT THIS TIME DUE TO STRONG CAPPING...THOUGH WILL CLOSELY MONITOR. IF STORMS DEVELOP...A FEW PULSE MICROBURSTS WITH GUSTY WINDS AND LOCALLY HEAVY RAIN WOULD BE POSSIBLE AS THE AIR WILL BE UNSTABLE. LATER TONIGHT THROUGH THURSDAY...GENERALLY HOT AND RAINFREE WEATHER WILL CONTINUE. LIKE YESTERDAY EVENING...A FEW STORMS MAY MOVE INTO FAR WESTERN OR NORTHWESTERN OKLAHOMA EACH NIGHT...BUT ODDS ARE GOOD THAT MOST LOCATIONS WILL STAY DRY. THINK HIGHS WILL INCREASE SLIGHTLY EACH DAY...ESPECIALLY AS THE GROUND DRIES OUT. A WEAK FRONT MAY MAKE IT TOWARDS THE AREA LATE WEDNESDAY INTO THURSDAY WHICH COULD BRING A BIT HIGHER RAIN CHANCES TO THE AREA. FOR NOW...KEPT RAIN CHANCES BELOW 20 PERCENT DURING THIS TIME FRAME. TEMPERATURES WILL GENERALLY BE 5 TO 10 DEGREES ABOVE AVERAGE. WEDNESDAY MAY BE THE HOTTEST DAY WITH TRIPLE DIGIT HEAT ACROSS MUCH OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 94 72 95 72 / 10 10 0 10 HOBART OK 97 71 100 71 / 10 10 0 10 WICHITA FALLS TX 98 72 99 72 / 10 10 0 0 GAGE OK 96 70 97 70 / 10 10 10 10 PONCA CITY OK 94 72 95 72 / 0 10 10 10 DURANT OK 93 72 94 72 / 0 0 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 03/17
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1156 PM CDT THU JUN 20 2013 .UPDATE...FOR 06Z AVIATION DISCUSSION. && .AVIATION...06Z AVIATION DISCUSSION. UNCERTANTIES...SHWRS/TSTMS ACTUAL LOCATION DEVELOPMENTAL IMPACTS... MVFR FOG FORMATION THRU 21/15Z. WITH RAINFALL NEAR ALL TAF SITES FROM AFTERNOON/EVENING CONVECTION...EXPECT WITH LIGHT WINDS AND RADITIONAL POTENTIAL THE POSSIBILITY OF TEMPO MVFR FOG CONDITIONS 21/08Z-21/12Z... MOST ENHANCED CSV. EXPECT ISO/SCT DIURNAL BASED SHWRS/TSTMS 21/19Z-22/02Z... BUT WITH LOCATIONAL DEVELOPMENT HARD TO PINPOINT THIS FAR OUT...BUT THE POSSIBILITY STILL THERE...WILL GO WITH VCTS REMARKS WITH CB MENTIONED. ACTIVITY SHOULD DISSIPATE BY 22/02Z WITH SCT CI POSSIBLE THRU 22/06Z. && .PREV DISCUSSION.../ISSUED 753 PM CDT THU JUN 20 2013/ UPDATE... WEAK MID LEVEL IMPULSE IN PLACE ACROSS THE MID STATE THIS EVENING. THIS HAS HELPED TO PRODUCE THE ISOL TO SCT SHOWER AND TSTM ACTIVITY EARLIER THIS AFTERNOON AND EVENING. ACTIVITY IS BEGINNING TO TAPER OFF AS WE CONTINUE TO LOSE OUR DAYTIME HEATING. LATEST 00Z LAPS INSTABILITY DATA SHOWING A MARKED DECREASE IN INSTABILITY LEVELS FROM 23Z TO 00Z. RADAR IS ALSO SHOWING A DECREASE IN INTENSITY AND IS FURTHER SUPPORTED BY AN HRRR CONVECTIVE DECREASE WITH TIME. WILL ISSUE UPDATE TO REMOVE THE LATE AFTERNOON WORDING. OTW...CONVECTION WILL STILL CONTINUE FOR ANOTHER HOUR OR TWO. ONCE CONVECTION COMPLETELY WINDS DOWN WILL REISSUE AGAIN AND REMOVE ALL CONVECTION FROM ZONES. REMAINDER OF THE GRIDDED DATA LOOKS TO BE IN GOOD SHAPE. UPDATE WILL BE ISSUED SHORTLY. PREV DISCUSSION.../ISSUED 623 PM CDT THU JUN 20 2013/ AVIATION 00Z DISCUSSION... WEAK MID LEVEL IMPULSE WILL MOVE EASTWARD ACROSS THE MID STATE THROUGH EARLY EVENING. AS A RESULT...ISOL SHOWERS AND TSTMS WILL BE POSSIBLE...GENERALLY PRIOR TO 03Z AND MAINLY ACROSS EASTERN AREAS OF THE MID STATE. AFT 03Z...SKIES WILL CLEAR WITH SOME SLIGHT BR VSBY REDUCTION FROM 06Z-12Z. SCT CONVECTIVE CU DECK AT 5KFT WILL RETURN ON FRIDAY AFTERNOON WITH ISOL STORMS POSSIBLE...MAINLY CSV AREA. PREV DISCUSSION.../ISSUED 304 PM CDT THU JUN 20 2013/ DISCUSSION... WEAK UPPER TROUGH REMAINS OVER THE REGION THIS AFTERNOON WITH SHORTWAVE JUST UPSTREAM. MODERATE MOISTURE SOURCE AND SLIGHTLY INCREASED INSTABILITY EXPECTED TO CONTINUE ISO-SCT CONVECTION INTO THE EARLY EVE. WEAK UPPER TROUGH WILL MAKE SLOW TRANSITION TO RIDGING INTO THE LATE WEEKEND...ALTHOUGH WEAK TROUGH AXIS DOES LINGER ALONG THE EASTERN SEABOARD. THIS WILL KEEP ANYTHING ORGANIZED FROM AFFECTING THE MID-SOUTH THUS CURRENT TREND WILL CONTINUE. MODERATE MOISTURE BELOW H7 AND DAYTIME HEATING/ELEVATED INSTABILITY WILL KEEP LARGELY DIURNAL ISO-SCT STORMS IN THE MIX THROUGH LATE SUNDAY. NO REAL APPRECIABLE CHANGES IN OVERALL PATTERN EARLY NEXT WEEK BUT CHANGES ARE IN SIGHT BY EARLY WED. UPPER RIDGE BREAKING DOWN MID-WEEK AS UPPER LOW SCOOTS NEAR THE US/CANADIAN BORDER. THIS WILL SHARPEN TROUGH OVER THE EASTERN US LATE WEEK...WITH AXIS SWINGING THROUGH POSSIBLY FRI. DAYTIME HEATING PUSHING TEMPS WELL INTO THE 80S TO AROUND 90 WILL PRODUCE DIURNAL CONVECTION THROUGH WED...WITH PCPN CHANCES RAMPING UP LATE IN THE WEEK WITH INCOMING TROUGH. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION...UPDATED
NWS SPOKANE WA
1039 PM PDT Thu Jun 20 2013 .SYNOPSIS... Rain will continue tonight and early Friday but will decrease in intensity and gradually subside by Friday evening. A drying and warming trend is expected Saturday and early Sunday with the exception of isolated mountain thunderstorms. More wet and cool weather will arrive as early as Sunday afternoon and persist through midweek followed by another warming, dry period to close out the work-week. && .UPDATE... Did an update to increase chance of precipitation most locations early this evening and then again overnight. Closed low currently resides over southern Alberta and will retrograde west back toward eastern WA and northern ID. HRRR model is hinting at some wrap around precipitation currently over southeastern British Columbia moving southwest through the evening and into the eastern Cascades overnight. Also the area of rain currently over the basin will slowly shift north and east through the evening and overnight hours into extreme eastern WA and north ID. So, overall a very wet, soggy night. Summer solstice is at 1004 tonight, and it feels like April. /Nisbet && .AVIATION... 06Z TAFS: The rain band from Spokane to Moses Lake has become less organized tonight and will continue through tomorrow morning as the upper support shears over the next 18 hours. Stratus is expected to develop through the early morning hours. Ceilings at or below 1000 feet at Spokane, Pullman, and Coeur D`Alene seems like a good bet. Summer solstice means the most daylight of the year, so it will be interesting to see how long we can keep stratus. The air mass will be very moist tomorrow, but the high sun angle should eventually break up the low cloud deck. Showers continue through the day, but finally have no mention of rain aft 23-03Z. && .PRELIMINARY POINT TEMPS/POPS... Spokane 46 59 46 70 50 75 / 100 70 20 10 0 20 Coeur d`Alene 44 59 45 69 48 75 / 100 70 40 20 10 20 Pullman 44 59 43 69 47 74 / 70 60 50 10 10 20 Lewiston 48 65 50 76 54 81 / 50 60 40 10 0 20 Colville 46 64 45 73 47 79 / 90 50 20 20 10 20 Sandpoint 46 60 46 67 45 74 / 100 70 50 30 30 20 Kellogg 45 57 44 65 47 72 / 100 70 60 30 30 20 Moses Lake 50 71 49 79 55 81 / 100 30 10 0 0 20 Wenatchee 51 71 52 78 59 80 / 100 20 10 0 0 20 Omak 48 71 49 77 52 80 / 80 20 10 10 0 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
308 AM CDT FRI JUN 21 2013 .TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM. THIS WARM...MOIST AND UNSTABLE SOUTHWESTERLY FLOW REGIME IS TYPICALLY DIFFICULT TO RESOLVE DETAILED CONVECTIVE TRENDS BEYOND ABOUT 12HRS. CONVECTION BEYOND 12HRS DEPENDS HIGHLY ON THE BEHAVIOR OF CONVECTION IN THE PRECEDING 12HRS. FOR INSTANCE...ALL THE HI RESOLUTION SHORT RANGE MODELS ARE HAVING DIFFICULTY WITH THE CONVECTION OVER MN EARLY THIS MORNING. EARLIER MODEL RUNS DEVELOPED THIS INTO A BIG BOW ECHO THAT RACED ACROSS THE FORECAST AREA AROUND 12Z. THE REALITY IS THAT IT IS STAYING UP TO THE NORTH MUCH LONGER AND MAY END UP JUST SKIRTING THE NORTHERN FORECAST AREA BEFORE DIMINISHING WITH TYPICAL DIURNAL TRENDS. THE TURN TO THE SOUTHEAST NEEDS THE COLD POOL DYNAMICS TO GET ORGANIZED AND THAT APPEARS TO BE HAPPENING AROUND 07Z THIS MORNING. EACH HRRR RUN HAS BEEN BACKING OFF ON THE SPEED AND OVERALL DEVELOPMENT. THE NOSE OF THE LOW LEVEL JET AND BEST INSTABILITY ARE TO THE WEST AND NORTH...BUT WILL LEAN NORTHEAST INTO THE AREA TODAY. THE MODELS CONTINUE TO BE TOO BULLISH ON SFC MOISTURE. FOR NOW...THERE DOES SEEM TO BE A CONSENSUS THAT WE WILL LIKELY SEE THE MN CONVECTION ROLL ACROSS THE AREA THIS MORNING AS THE LOW LEVEL JET AND MOISTURE LEAN INTO THE AREA. THIS SHOULD LAY OUT A LOW LEVEL BAROCLINIC ZONE THAT COULD BE THE FOCUS FOR MORE CONVECTION LATER THIS AFTERNOON. WE SHOULD SEE ANOTHER MCS DEVELOP OUT IN THE PLAINS THIS AFTERNOON AND ROLL INTO THE CWA LATER TONIGHT. SO LONG STORY SHORT...LOOK FOR MORNING CONVECTION TO DIMINISH THIS AFTERNOON WITH ANOTHER ROUND LATE TONIGHT INTO SATURDAY MORNING. TEMPS MIGHT BE HELD DOWN A BIT TODAY IF WE ARE SLOW TO SCOUR OUT THE MORNING CONVECTIVE DEBRIS. TEMPS WON/T DROP TOO FAR TONIGHT AS WE ARE SOLIDLY IN THE WARM SECTOR. SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH. PRECIP CHANCES CONTINUE TO EXIST EARLY ON THIS PERIOD EVEN THOUGH 500 HPA SHORT WAVE TROUGHS TRAVERSE MAINLY TO OUR NORTH AND WEST. CWA CONTINUES TO LIE UNDER A MID-LEVEL RIDGE WITH SHORT WAVE TROUGHS RIDING THROUGH. THE NOCTURNAL LLJ MAINLY FOCUSES ON SOUTHWEST AND WEST CENTRAL WISCONSIN...PEAKING SATURDAY NIGHT. MODELS DO SHOW LOW-LEVEL WAA AT THIS TIME...BUT WAA MORE PERSISTENT AND STRONGER OUTSIDE THE CWA. FURTHER...ALTHOUGH SOME SYNOPTIC LIFT WILL BE PRESENT IN THE PERIOD...THE THERMODYNAMIC ENVIRONMENT WILL NOT BE THAT PRIMED. BUFKIT SOUNDINGS AND LOW-LEVEL THERMO ENVIRONMENT SHOW A CAPPED ENVIRONMENT COINCIDING WITH LOW-LEVEL THERMAL RIDGE. THIS COULD POTENTIALLY LIMIT OUR THUNDER CHANCES THIS WEEKEND. OTHERWISE...AMPLE MEAN LAYER INSTABILITY IN THE PERIOD WILL COMBINE WITH SUFFICIENT MOISTURE...ESPECIALLY CONSIDERING SFC DEW POINTS FCST IN THE UPPER 60S TO AROUND 70 DURING THE DAY SAT AND SUN. SHEAR WILL BE A LIMITING FACTOR THOUGH FOR ANY ORGANIZED DEVELOPMENT IN THE PERIOD. DEEP LAYER 0-6KM SHEAR IS ONLY AROUND 15-25 KTS. THIS SUGGEST ORDINARY THUNDERSTORMS AND SOME MULTICELL ORGANIZATION TYPE STORM MODES. SATURDAY IS EXPECTED TO GIVE THE CWA THE BEST CHANCE FOR CONVECTION GIVEN THE BETTER INSTABILITY AND PROXIMITY OF THE EFFECTIVE BOUNDARY. THOUGH GIVEN THE AFOREMENTIONED CAP AND THE UNCERTAIN POSITION OF THE BOUNDARY...CONTINUED WITH CHANCES ON SATURDAY. WARM AND ABOVE NORMAL HIGHS EXPECTED SATURDAY AND SUNDAY. MODEL CONSENSUS OF 925 HPA TEMPS ARE AROUND 25-27 C SAT AND 24-26 C SUN THAT CORRESPOND TO 89-93 F AND 87-91 F...RESPECTIVELY. NOTE...WILL HAVE TO WATCH APPARENT TEMPS/HEAT INDEX VALUES SUNDAY GIVEN THE MOIST SFC DEW POINTS IN THE UPPER 60S/AROUND 70 AND SFC HIGHS AROUND 90 IN PORTIONS OF THE CWA...AS HEAT INDEX VALUES REACH LOW AND MID 90S SAT AND WELL INTO THE MID AND UPPER 90S SUN. POTENTIAL RISK OF HEAT INDEX VALUES FURTHER SUBSTANTIATED BY LOOKING AT CIPS IMPACT BASED GUIDANCES PROBABILITY OF SFC HEAT INDEX VALUES EXCEEDING 95 F THAT HAS HIGH PROBS IN SOUTH CENTRAL AND SOUTHEAST WI. MONDAY THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE MEDIUM. PERIOD CHARACTERIZED GENERALLY BY A MID-LEVEL ZONAL FLOW...THAT BREAKS DOWN LATE THURSDAY INTO FRIDAY AS A MORE AMPLIFIED PATTERN TAKES OVER. THE LATTER SHARED BY BOTH THE GFS AND ECMWF. VARIOUS S/W TROUGHS MOVE THROUGH THOUGH DIFFERENCES BETWEEN FEATURES AND TIMING MAKE FCST UNCERTAIN. THE GENERAL SW FLOW AND THERMAL ENVIRONMENT THOUGH SHOULD KEEP READINGS NEAR OR ABOVE THEIR SEASONAL NORMAL VALUES. SEASONAL NORMAL VALUES THIS TIME OF THE YEAR ARE USUALLY AROUND 81-82 TO 78-79 WEST TO EAST ACROSS THE CWA. BY THURSDAY INTO FRIDAY WITH A LONG WAVE TROUGH DIGGING INTO THE GREAT LAKES REGION...FLOW BECOMES MORE OUT OF THE NW-N AND HIGH TEMPERATURES BEGIN TRENDING DOWNWARD. && .AVIATION/12Z TAFS/...MAIN AVIATION CONCERN DURING THE PERIOD IS TIMING OF ANY CONVECTION...AND THAT WILL BE CHALLENGING. OVERALL...CONDITIONS SHOULD BE VFR. THE EXCEPTION WILL BE IN AND AROUND ANY THUNDERSTORMS WHERE VSBY AND CIGS COULD BRIEFLY DROP TO MVFR LEVELS. WE SHOULD SEE STORMS MOVE THROUGH THE AREA THIS MORNING...AS THE REMNANTS OF STORMS UP TO OUR NORTHWEST EARLY THIS MORNING ROLL SOUTHEAST THROUGH THE AREA. THERE SHOULD BE A BREAK IN THE ACTIVITY THIS AFTERNOON...BUT CAN/T RULE OUT NEW DEVELOPMENT ALONG ANY REMNANT OUTFLOW/BAROCLINIC BOUNDARIES DURING THE HEAT OF THE AFTERNOON. THE NEXT BEST CHANCE FOR STORMS WOULD BE LATER TONIGHT AS ANOTHER LARGE COMPLEX OF STORMS THAT DEVELOPS UPSTREAM EARLIER IN THE AFTERNOON ROLLS IN. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...DAVIS SATURDAY THROUGH THURSDAY...ET
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
214 AM CDT FRI JUN 21 2013 .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 214 AM CDT FRI JUN 21 2013 AS SOUTHWEST UPPER FLOW CONTINUES TO ADVECT WARM AIR AND MOISTURE INTO UPPER MIDWEST...FORECAST CHALLENGE REMAINS TIMING MESOSCALE CONVECTIVE COMPLEXES. SEEMS LIKE A DIFFICULT TASK AT TIMES ONLY A FEW HOURS OUT. UPPER LOW CONTINUES TO SPIN OVER NORTHWEST U.S. WITH LARGE WESTERN CONUS TROUGH. STEADY LOW LEVEL JET EARLY THIS MORNING AROUND 45 KTS IS FUELING LARGE CONVECTIVE SYSTEM OVER CENTRAL MINNESOTA. CELLS STARTED OVERNIGHT A BIT MORE DISCRETELY BUT AS COLD POOL HAS BEEN DEVELOPING...MORE OF A LINEAR STRUCTURE UNFOLDING WHICH MAY CONTINUE BUILDING SOUTHEAST ALONG WELL DEFINED WARM FRONT OR BOUNDARY INTO AREA BEFORE DAYBREAK. LOWER MIXED LAYER CAPE VALUES AND LOWER SHEAR WOULD SUGGEST SYSTEM COULD WEAKEN AS IT APPROACHES WISCONSIN BUT WILL HAVE TO MONITOR THIS...WHICH COULD INCLUDE A FEW WARNINGS. HAVE ALSO BEEN TRACKING BAND OF CONVECTION ACROSS WESTERN WISCONSIN THAT SEEM TO DEVELOP ALONG MID LEVEL NOSE OF WARMER AIR BUT SEEMS UNLIKELY THESE WOULD UPSCALE INTO ANYTHING OF SIGNIFICANCE. MESOSCALE MODELS AND SHORT TERM MODELS CONTINUE TO CHANGE NEARLY AS QUICKLY AS RADAR IMAGERY WHICH HURTS ANY CONFIDENCE IN THIS FORECAST. WITH BASIC UPPER AIR PATTERN CHANGING LITTLE...HAVE BEEN TRYING TO TIME THINGS BASED ON BEST SIGNALS OF MOISTURE TRANSPORT. THIS TENDS TO INCREASE ACROSS OUR AREA NEXT 48 HOURS SO EXPECT GRADUAL TREND IN CONVECTIVE SYSTEM DEVELOPMENT ZONE FROM DAKOTAS AND WESTERN MINNESOTA CLOSER TO UPPER MISSISSIPPI RIVER AREA GOING INTO WEEKEND. THIS SHOULD BOOST RAIN THREAT AS WELL...BUT EXACTLY WHEN IS DIFFICULT. PLENTY OF CAPE TO WORK WITH ALTHOUGH DEEPER SHEAR DOES REMAIN FURTHER NORTHWEST...CLOSER TO DYNAMICS. COULD SEE A BREAK IN ACTION LATER TODAY BEFORE ADDITIONAL DEVELOPMENT TAKES PLACE AROUND RIDGE HEADING INTO FRIDAY NIGHT. SAME PATTERN COULD KEEP GOING INTO SUNDAY NIGHT. REPEAT ROUNDS OF CONVECTION COULD ALSO LEAD TO PROBLEMATIC FLOOD THREAT BUT GIVEN UNCERTAINTY OF TRACKS OF THESE SYSTEMS...WILL HAVE TO MONITOR SHORT TERM CONDITIONS FOR ANY SPECIFIC FOCUS AREAS. TEMPERATURES SHOULD REMAIN FAIRLY PERSISTENT FROM DAY TO DAY WITH SUBTLE CHANGES DEPENDING ON HOW MUCH CLOUD DEBRIS IMPACTS HIGHS. DID DROP HIGHS TODAY NORTH AND EAST OF LA CROSSE WHERE CONFIDENCE IN CLOUD SHIELD INTO AFTERNOON IS HIGHEST. WARMEST LOW LEVEL TEMPERATURES COME IN OVER WEEKEND SO DID BOOST HIGHS A FEW DEGRESS. IN ADDITION...DEW POINTS DID NOT RESPOND AS QUICKLY AS EXPECTED ON THURSDAY...PERHAPS DUE TO RECENT DRY WEATHER...SOURCE REGION OF AIRMASS...AND IMMATURE CROPS. SCALE BACK CLIMB OF DEW POINTS ANOTHER 24 HOURS BUT OVER TIME AS MORE SOUTHWEST FLOW DEVELOPS...EXPECT THE LOWER 70 DEGREE DEW POINTS TO ADVECT INTO AREA WITH MUGGY CONDITIONS BEFORE WEEKEND ENDS. THIS COULD BOOST HEAT INDEX VALUES INTO 95 TO 100 DEGREES AT PEAK HEATING DURING MID TO LATE AFTERNOONS. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 214 AM CDT FRI JUN 21 2013 LATER FORECAST PERIODS WILL INVOLVE PATTERN SHIFT AS HEIGHTS RISE IN THE WESTERN CONUS. UPPER LOW OVER NORTHWEST...OR ROUNDS OF SHORT WAVE ENERGY...WILL EVENTUALLY SHIFT ALONG NORTHERN TIER OF STATES OR FAR SOUTHERN CANADA AS NORTHWEST FLOW DEVELOPS INTO WESTERN GREAT LAKES. AS RIDGE AHEAD OF TROUGH BREAKS DOWN...COULD SEE BOUNDARY EVENTUALLY SHIFT SOUTH THROUGH AREA WITH EVEN MORE CHANCES OF CONVECTION WELL INTO EARLY NEXT WEEK. EXPECT COOLING TREND IN THIS SCENARIO AS WELL BUT COULD BE MORE GRADUAL THAN A SHARP COLD FRONT. MEDIUM RANGE GUIDANCE SUGGESTS SHORT WAVE TROUGH COULD DROP THROUGH IN DEVELOPING NORTHWEST FLOW LATE WEDNESDAY INTO THURSDAY MORNING COULD SPARK YET MORE RAIN SHOWERS BEFORE DRIER...NORTHWEST REGIME SETS UP AS WESTERN MEAN RIDGE BUILDS TO CLOSE OUT THE MONTH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1138 PM CDT THU JUN 20 2013 COMPLEX OF STORMS OVER NORTHWEST MINNESOTA INTO EASTERN NORTH DAKOTA HAS YET TO FORM INTO A LINE AND START MOVING MOVING EAST AS EARLIER DEPICTED BY SEVERAL MODELS. THE 21.02Z HRRR NOW SUGGESTS THAT THIS COMPLEX OF STORMS WILL NEVER GET HERE BUT RATHER STAY NORTH OF THE WARM FRONT THAT EXTENDS ACROSS CENTRAL MINNESOTA INTO NORTHERN WISCONSIN. RATHER...ADDITIONAL DEVELOPMENT IS EXPECTED TO OCCUR SOUTH OF THE BOUNDARY IN THE LOW LEVEL JET AND MOISTURE TRANSPORT AXIS OVER SOUTHERN MINNESOTA INTO NORTHERN IOWA. SOME INDICATIONS THAT THIS IS OCCURRING WITH RECENT DEVELOPMENT OVER SOUTHERN MINNESOTA. THE HRRR THEN CONTINUES TO EXPAND THIS THROUGH THE NIGHT AND BRINGS IT INTO THE AREA LATE. HAVE THUS CONTINUED THE TRENDS OF THE PREVIOUS FORECASTS BUT PUSHED THE TIMING BACK JUST A LITTLE. COULD STILL SEE SOME GUSTY WINDS AND MVFR VISIBILITY RESTRICTIONS SO MAINTAINED THOSE TRENDS AS WELL. STILL EXPECTING THE ACTIVITY TO CLEAR THE AREA BY THE MIDDLE OF FRIDAY MORNING WITH LITTLE CHANCE OF ANYTHING AFTER THAT FOR THE REMAINDER OF THE PERIOD WITH THE NEXT ROUND OF STORMS REMAINING WELL OFF TO THE WEST THROUGH 22.06Z. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...SHEA LONG TERM....SHEA AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1138 PM CDT THU JUN 20 2013 .SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 316 PM CDT THU JUN 20 2013 MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES AND POTENTIAL SEVERE WITH THUNDERSTORMS THROUGH PERIOD. LATEST WATER VAPOR SATELLITE IMAGERY SHOWING WEAK SHORTWAVE TROUGH LIFTING NORTHEAST INTO NORTH CENTRAL WISCONSIN AND A SERIES OF SHORTWAVE TROUGHS OVER LAKE SUPERIOR WESTWARD TO NORTH DAKOTA. LATEST MOSAIC RADAR INDICATES SHOWERS AND THUNDERSTORMS ACROSS NORTHERN WISCONSIN INTO EASTERN NORTH DAKOTA. THIS IS IN RESPONSE TO 925-850MB MOISTURE TRANSPORT AND NOSE OF LOW LEVEL JET PER 20.15Z RAP. THE 20.12Z GFS/NAM CONTINUE TO BE IN GOOD AGREEMENT IN CARVING UPPER LEVEL TROUGH OVER THE WESTERN UNITED STATES AND EJECTING OUT A SERIES OF SHORTWAVE TROUGHS EMBEDDED IN SOUTHWESTERLY FLOW ALOFT INTO THE NORTHERN PLAINS AND UPPER GREAT LAKES REGION OVER THE NEXT SEVERAL DAYS. BIGGEST DIFFERENCES REMAIN ARE THE TIMING AND PLACEMENT OF THE SHORTWAVE TROUGHS OVER THE UPPER GREAT LAKES REGION THROUGH THE PERIOD. THE DETERMINISTIC MODELS ARE OKAY IN AGREEMENT WITH SURFACE FRONT PLACEMENT THROUGH 12Z SATURDAY...THEN THE 20.12Z NAM PUSHES SURFACE FRONT FARTHER SOUTH THAN THE GFS. CONFIDENCE IN FORECAST BEGINS TO LOWER AFTER 12Z SATURDAY. TONIGHT INTO FRIDAY...THE 20.12Z GFS/NAM AND 20.15Z RAP ALL INDICATING DECENT 925-850MB MOISTURE TRANSPORT AND LOW LEVEL JET TO INCREASE THIS EVENING OVER FORECAST AREA. WITH A SERIES OF SHORTWAVE TROUGHS OVER THE NORTHERN PLAINS...HIGH RESOLUTION MODELS OF THE 20.12Z SPC WRF...20.12Z ARW-EAST AND 20.16Z HRRR SHOW A COMPLEX OF THUNDERSTORMS OVER EASTERN NORTH DAKOTA AND NORTHERN SOUTH DAKOTA ON THE NOSE OF THE LOW LEVEL JET/925-850MB MOISTURE TRANSPORT...TO MOVE EAST-SOUTHEAST INTO THE NORTHERN PORTIONS OF THE FORECAST AREA AROUND 09Z TO 12Z. THE 20.12Z GFS/NAM INDICATE SOME SORT OF COMPLEX OF THUNDERSTORMS TO TRACK INTO THE NORTHERN PORTIONS OF THE FORECAST AREA. CONFIDENCE IS INCREASING A COMPLEX OF THUNDERSTORMS WILL MOVE INTO THE NORTHERN PORTIONS OF THE FORECAST AREA. SEVERE POTENTIAL STILL EXIST WITH THE 20.12Z GFS/NAM SHOW 0-3KM SHEAR OF 25-35 KNOTS AND 0-6KM MOST UNSTABLE CAPE OF 1000-2000 J/KG OVER NORTHERN PORTIONS OF FORECAST AREA 06Z-12Z FRIDAY. THE COMPLEX OF STORMS SHOULD DEVELOP INTO A LINE/SQUALL LINE OF STORMS OVERNIGHT AND HAVE THE POTENTIAL FOR DAMAGING WINDS ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA. FRIDAY NIGHT INTO SUNDAY...ACTIVE WEATHER PATTERN CONTINUES...AS THE 20.12Z GFS/NAM CONTINUE TO INDICATE A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE UPPER MIDWEST AND UPPER GREAT LAKES REGION. THE 20.12Z GFS/NAM CONTINUE TO HAVE DIFFERENCES IN TIMING AND PLACEMENT OF THE SHORTWAVE TROUGHS/SURFACE FRONT ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION. THE DETERMINISTIC MODELS DO SHOW 20 TO 30 KNOTS OF 0-3KM WIND SHEAR AND ELEVATED CAPE OF A 2000- 3000 J/KG FRIDAY THROUGH 06Z SATURDAY. POTENTIAL IS THERE FOR THUNDERSTORMS TO BECOME SEVERE WITH THE MAIN THREAT TO BE DAMAGING WINDS. HOWEVER...THE DETERMINISTIC MODELS ARE FOCUSING THE BEST CHANCES FOR CONVECTION TO AFFECT MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH SUNDAY...WITH THE 20.12Z GFS SUGGESTING MUCH OF THE CONVECTION TO BE NORTH AND NORTHWEST OF THE FORECAST AREA. CONFIDENCE IN FORECAST REMAINS LOW FRIDAY NIGHT INTO SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 316 PM CDT THU JUN 20 2013 MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THROUGH THE PERIOD. THE 20.12Z GFS/NAM/GEM ARE IN AGREEMENT IN EJECTING OUT A COUPLE OF SHORTWAVE TROUGHS INTO THE UPPER MIDWEST THROUGH 00Z WEDNESDAY...THEN MODELS BEGIN TO DIG UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION AND DEVELOP NORTHWEST FLOW ALOFT OVER FORECAST AREA WEDNESDAY INTO THURSDAY. WITH ENOUGH LIFT AND MOISTURE IN ASSOCIATION WITH SHORTWAVE TROUGHS WILL CONTINUE WITH SMALL CHANCES OF PRECIPITATION THROUGH MUCH OF THE PERIOD. TEMPERATURES THROUGH 12Z WEDNESDAY WILL BE ABOVE NORMAL...AS THE DETERMINISTIC MODELS ADVECT WARMER AIR ALOFT INTO FORECAST AREA MONDAY INTO TUESDAY. THE 20.12Z GFS/ECMWF ARE SHOWING 925MB TEMPERATURES PLUS 24 TO 27 DEGREES CELSIUS BY 00Z WEDNESDAY AND THE 20.00Z GEFS INDICATE STANDARDIZED ANOMALIES OF 1-1.5 ABOVE NORMAL. THIS WILL ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 80S TO POSSIBLY INTO THE MIDDLE 90S ACROSS FORECAST AREA. COOLER AIR WILL FILTER INTO THE FORECAST BEHIND SURFACE LOW/SHORTWAVE TROUGH WEDNESDAY INTO THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1138 PM CDT THU JUN 20 2013 COMPLEX OF STORMS OVER NORTHWEST MINNESOTA INTO EASTERN NORTH DAKOTA HAS YET TO FORM INTO A LINE AND START MOVING MOVING EAST AS EARLIER DEPICTED BY SEVERAL MODELS. THE 21.02Z HRRR NOW SUGGESTS THAT THIS COMPLEX OF STORMS WILL NEVER GET HERE BUT RATHER STAY NORTH OF THE WARM FRONT THAT EXTENDS ACROSS CENTRAL MINNESOTA INTO NORTHERN WISCONSIN. RATHER...ADDITIONAL DEVELOPMENT IS EXPECTED TO OCCUR SOUTH OF THE BOUNDARY IN THE LOW LEVEL JET AND MOISTURE TRANSPORT AXIS OVER SOUTHERN MINNESOTA INTO NORTHERN IOWA. SOME INDICATIONS THAT THIS IS OCCURRING WITH RECENT DEVELOPMENT OVER SOUTHERN MINNESOTA. THE HRRR THEN CONTINUES TO EXPAND THIS THROUGH THE NIGHT AND BRINGS IT INTO THE AREA LATE. HAVE THUS CONTINUED THE TRENDS OF THE PREVIOUS FORECASTS BUT PUSHED THE TIMING BACK JUST A LITTLE. COULD STILL SEE SOME GUSTY WINDS AND MVFR VISIBILITY RESTRICTIONS SO MAINTAINED THOSE TRENDS AS WELL. STILL EXPECTING THE ACTIVITY TO CLEAR THE AREA BY THE MIDDLE OF FRIDAY MORNING WITH LITTLE CHANCE OF ANYTHING AFTER THAT FOR THE REMAINDER OF THE PERIOD WITH THE NEXT ROUND OF STORMS REMAINING WELL OFF TO THE WEST THROUGH 22.06Z. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM....DTJ AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
636 AM EDT FRI JUN 21 2013 .SYNOPSIS... HIGH PRESSURE WILL TAKE UP RESIDENCE JUST OFF THE EASTERN SEABOARD TODAY INTO THE WEEKEND. A SOUTHWESTERLY FLOW AROUND THIS HIGH PRESSURE AREA WILL RESULT IN WARMER TEMPERATURES AND RISING LEVELS OF HUMIDITY. ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE EACH DAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 630 AM EDT...AS HIGH PRESSURE SETTLES IN JUST OFF THE EASTERN SEABOARD TODAY...A RETURN WEST-SOUTHWEST FLOW ALOFT WILL DEVELOP AND ALLOW TEMPERATURES TO WARM MORE THAN PREVIOUS DAYS. NAM/GFS STILL SHOWING A SUBTLE LOW LEVEL CONVERGENCE ZONE SETTING UP FROM JUST SOUTH OF KALB TO NEAR KPOU...MAINLY SEEN ON SURFACE WIND FIELDS. INSPECTING HIGHER RESOLUTION MODELS...THE 4KM WRF- NMM...LOCAL HIRESWRF AND EVEN THE HRRR SHOWING A FEW CELLS POPPING UP IN THE GENERAL VICINITY OF THE CONVERGENCE ZONE THIS AFTERNOON. COVERAGE LOOKS TO BE ISOLATED AT BEST...WITH MOST OF THE AREA ESPECIALLY FROM ALBANY NORTHWARD REMAINING DRY. INSTABILITY LOOKS MEAGER...BUT GIVEN SLIGHTLY HIGHER DEWPOINTS AND TEMPS IN THE 80S...WILL MENTION POSSIBLE THUNDER. THERE MAY BE A FEW MORE CLOUDS AROUND THAN PRIOR DAYS...BUT SKIES SHOULD STILL AVERAGE MOSTLY-PARTLY SUNNY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... ANY ISOLATED CONVECTION WILL QUICKLY DIMINISH THIS EVENING WITH LOSS OF DAYTIME HEATING. TEMPERATURES WILL BE MILDER THAN THE PAST FEW NIGHT DUE TO CONTINUED WARMING ALOFT. THE WEEKEND WILL FEATURE SUMMER-LIKE WARMTH ALONG WITH THE CHANCE FOR SOME THUNDERSTORMS...WHICH WILL MAINLY BE DIURNALLY DRIVEN. THERE ARE SOME SUBTLETIES THAT WILL HAVE AN IMPACT ON COVERAGE/TIMING OF CONVECTION. ON SATURDAY...THE REGION WILL STILL BE UNDER THE INFLUENCE OF A W-NW FLOW ALOFT ON THE NORTHERN PERIPHERY OF A BUILDING UPPER LEVEL RIDGE OVER THE OHIO VALLEY AND MID ATLANTIC REGION. VARIOUS SOURCES OF GUIDANCE INDICATING A WEAK DISTURBANCE OR TWO EMBEDDED IN THE FLOW WILL PASS THROUGH MAINLY THE NORTHERN HALF OF THE AREA. THIS COULD BE ENOUGH FORCING TO TRIGGER SCATTERED CONVECTION GIVEN AN INCREASE IN LOW LEVEL DEWPOINTS AND PRECIPITABLE WATER NEARING OR EXCEEDING 1.5 INCHES. WILL MENTION CHANCE POPS ACROSS THE NORTHERN 2/3 OF THE AREA...WITH SLIGHT CHANCE SOUTH. SBCAPE GENERALLY FORECAST TO BE AROUND 500-1000 J/KG...WITH 850-500MB LAPSE RATES ONLY AROUND 5.5 TO 6.0 C/KM...SO T-STORMS ARE NOT EXPECTED TO BE SEVERE. DEPENDING ON EVENTUAL DEGREE OF CLOUD COVER SATURDAY AFTERNOON...TEMPERATURES COULD REACH THE MID 80S IN MOST VALLEY LOCATIONS. CONVECTION SHOULD DIMINISH DURING THE EVENING HOURS AS DAYTIME HEATING IS LOST AND THE UPPER LEVEL DISTURBANCES MOVE EAST OF THE REGION. SUNDAY MAY FEATURE ADDITIONAL MAINLY SCATTERED SHOWERS AND T-STORMS...WHICH SHOULD BE DIURNALLY DRIVEN AND POSSIBLY EVEN TIED TO TERRAIN/DIFFERENTIAL HEATING AREAS AS THE UPPER RIDGE BUILDS ACROSS THE AREA. THE NAM IS DEPICTING A FLATTER FLOW REGIME ALOFT...WHILE THE GFS/ECMWF TENDS TO BUILD THE UPPER RIDGE MORE. SINCE IT IS A COUPLE DAYS AWAY...THERE IS QUITE A BIT OF UNCERTAINTY AS TO THE DEGREE OF CONVECTION THAT EVOLVES. WILL MENTION LOW CHANCE POPS FOR MUCH OF THE AREA...WITH SLIGHT CHANCE SOUTH. WILL HAVE TO WATCH UPSTREAM OVER THE UPPER GREAT LAKES FOR ANY CONVECTIVE FOOTPRINTS THAT MAY EVENTUALLY IMPACT THE REGION...ESPECIALLY IF WE REMAIN ON THE NORTHERN PERIPHERY OF THE UPPER RIDGE. SUNDAY SHOULD BE THE WARMEST DAY SINCE JUNE 2ND ACROSS THE AREA AS ADDITIONAL WARMING ALOFT OCCURS WITH MID TO UPPER 80S EXPECTED FOR MUCH OF THE REGION. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FLAT BROAD UPPER RIDGING SHOULD SET UP OVER EASTERN NORTH AMERICA WITH SMALL PIECES OF UPPER LEVEL ENERGY TRACKING AROUND THE NORTHERN PERIPHERY OF THE RIDGE MONDAY THROUGH TUESDAY NIGHT. THESE LITTLE PIECES OF UPPER ENERGY SHOULD ENHANCE THE THREAT OF SHOWERS/TSTMS EACH AFTN/EVENING AND HAVE FORECAST 30 TO 40 PERCENT POPS EACH AFTN/EVENING...AND 20 TO 30 PERCENT POPS DURING THE OVERNIGHT AND MORNING HOURS. FOR SUNDAY NIGHT HAVE FORECAST DRY CONDITIONS. ALTHOUGH NOT AS IMPRESSIVE AS LAST NIGHT...THE GFS/ECMWF STILL SHOW A DEEPENING UPPER LEVEL TROF WILL MOVE INTO THE REGION BY WEDNESDAY AFTN WITH AN EVEN GREATER THREAT FOR SHOWERS/TSTMS WED AFTN THROUGH THURSDAY. FOR EACH AFTN/EVENING DURING THIS PERIOD HAVE FORECAST 40 TO 50 PERCENT POPS...AND 30 TO 40 PERCENT DURING THE OVERNIGHT AND EARLY MORNING HOURS. IT WILL BE VERY WARM OR HOT EARLY IN THE LONG TERM PERIOD...WITH A BIT OF A COOL DOWN WEDNESDAY AND THURSDAY AS THE UPPER LEVEL TROF MOVES INTO THE REGION. IT WILL BE HUMID DURING THE ENTIRE PERIOD WITH DEWPOINTS GENERALLY IN THE 60S. HIGHS MONDAY AND TUESDAY WILL BE IN THE 80S TO AROUND 90...THEN UPPER 70S AND 80S WEDNESDAY...AND MID 70S TO LOWER 80S THURSDAY. LOWS WILL GENERALLY BE IN THE UPPER 50S AND 60S SUNDAY NIGHT THROUGH WEDNESDAY NIGHT. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... ANY LEFTOVER FOG AT KGFL/KPSF WILL HAVE DISIPATED BY THE START OF THE NEW TAF PERIOD (12Z). SO EXPECT VFR CONDITIONS AT THE KALB/KPOU/KGFL/KPSF TAF SITES THROUGH TONIGHT. THE EXCEPTION WILL BE POSSIBLE LATE NIGHT MVFR/IFR FOG AT KGFL/KPSF. WITH HIGH PRESSURE OVER THE REGION CONDITIONS WILL BE MAINLY P6SM SCT250 WITH A FEW CUMULUS CLOUDS THIS AFTERNOON. LATE TONIGHT THE HIGH CLOUDS SHOULD BECOME BKN. LIGHT SURFACE WINDS EARLY THIS MORNING WILL BECOME SOUTH TO SOUTHWEST AT LESS THAN 8 KTS DURING THE REST OF FRIDAY...THEN MAINLY CALM WINDS AGAIN TONIGHT. OUTLOOK... SAT...MAINLY VFR. SLGT CHC -TSRA/-SHRA. SUN-TUE...MAINLY VFR. CHC -TSRA/-SHRA. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS CONTINUE DUE TO THE PAST SEVERAL WEEKS OF WET WEATHER. HIGH PRESSURE WILL MOVE OFF THE EAST COAST TODAY INTO THE WEEKEND. ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS ARE POSSIBLE FROM THIS AFTERNOON AFTERNOON THROUGH THE WEEKEND...ALONG WITH A GRADUAL WARMING TREND. DEW FORMATION SHOULD OCCUR EACH NIGHT WITH THE RISING LEVELS OF HUMIDITY. && .HYDROLOGY... FLOWS REMAIN ABOVE NORMAL ACROSS THE HYDRO SERVICE AREA. FROM TODAY INTO EARLY NEXT WEEK...THERE MAY ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS...BUT WIDESPREAD RAINFALL IS NOT ANTICIPATED AT THIS TIME...AND NOT ALL LOCATIONS WILL SEE RAINFALL. THUS...RIVER LEVELS ARE EXPECTED TO CONTINUE TO GRADUALLY RECEDE DURING THIS TIME. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...GJM AVIATION...GJM FIRE WEATHER...FRUGIS/JPV HYDROLOGY...FRUGIS/JPV
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1039 AM CDT FRI JUN 21 2013 .DISCUSSION... ISSUED 1039 AM CDT FRI JUN 21 2013 SEVERE CONVECTIVE COMPLEX TO OUR NORTH MAIN ISSUE. THIS HAS BEEN MAINTAINED BY A 40-45 KT SW 925 MB LOW LEVEL JET EVIDENT ON AREA VWP/S AND A SIGNIFICANT SHORTWAVE SHIFTING THROUGH NRN WI. LATEST RAP FORECASTS INDICATE THE LLJ WEAKENING TO AROUND 20 KTS AND BACKING AROUND TO THE SOUTH BY MIDDAY...AND CONVECTIVE MODEL WHICH HAS BEEN HANDLING THIS COMPLEX BEST /3-KM HRRR/ SHOWS LINE WEAKENING AS IT SHIFTS SE INTO AFTERNOON. LATEST RADAR TRENDS SHOW COLD POOL HAS SURGED OUT WELL AHEAD OF THE MIDDLE PORTION OF THE LINE WITH A WEAKENING TREND ALREADY NOTED DOWN THE MISSISSIPPI VALLEY...WHILE SVR/NEAR SVR WIND GUSTS CONTINUE IN PARTS OF NE IA AN NORTH CENTRAL IL. ALSO BEST SHEAR REMAINS TO OUR NORTH TIED TO THE SHORTWAVE AND WITH ALL THESE FACTORS IN MIND FEEL ACTIVITY WILL WEAKEN AS IT APPROACHES THE NORTHERN CWA IN THE NEXT FEW HOURS. HAVE UPPED POPS TO MID-HIGH CHANCE NORTH OF A GALESBURG TO EL PASO LINE FOR EARLY AFTERNOON WITH CHANCES QUICKLY DIMINISHING SOUTH OF THERE AS ACTIVITY TENDS TO FADE BY MID AFTERNOON. WILL KEEP A CLOSE EYE ON THESE TRENDS THOUGH AS 1500-2000 J/KG MLCAPES WILL BE PRESENT OVER CENTRAL IL. ANOTHER CONCERN WILL BE POTENTIAL MID/LATE AFTERNOON DEVELOPMENT ALONG RESULTING OUTFLOW BOUNDARY AND SOME HI-RES GUIDANCE INCLUDING HRRR AND 4KM NSSL WRF POINT TO A FAVORED AREA ALONG AN INSTABILITY AXIS IN SE IA/NE MO/WEST CENTRAL IL AFTER 21Z. THUS HAVE SLIGHT CHANCE POPS FOR THE FAR WEST LATE AFTERNOON. OTHERWISE...BULK OF CWA SHOULD REMAIN DRY TODAY AND HOT AND HUMID WEATHER WILL BE THE MAIN STORY. 10 AM TEMPS ALREADY IN THE MID 80S AND WHILE INCOMING CIRRUS SHIELD MAY INHIBIT TEMP RISE SOMEWHAT...STILL THINK WIDESPREAD HIGHS IN THE LOW 90S LIKELY. THESE TEMPS COMBINED WITH DEWPOINTS IN THE UPPER 60S WILL PRODUCE AFTERNOON HEAT INDICES IN THE MID TO UPPER 90S. 25 && .AVIATION... ISSUED 655 AM CDT FRI JUN 21 2013 1027 MB HIGH PRESSURE OFF THE MID ATLANTIC COAST AND RIDGING WESTWARD INTO THE OHIO VALLEY TO BE NEARLY STATIONARY INTO SAT MORNING WHILE 1003 MB LOW PRESSUE OVER EASTERN CO INTO SW NEBRASKA WITH FRONTAL BOUNDARY EXTENDING NE INTO SOUTHERN MN TO ALSO REMAIN IN PLACE NEXT 24 HOURS. VFR CONDITIONS SHOULD CONTINUE ACROSS THE CENTRAL IL TERMINAL AIRPORTS NEXT 24 HOURS THROUGH 12Z/7 AM SAT. SCATTERED TO BROKEN MID/HIGH CLOUDS TO SPREAD SE FROM THE IL RIVER ACROSS CENTRAL IL DURING TODAY AS SCATTERED CUMULUS CLOUDS WITH BASES OF 4-6K FT DEVELOP AFTER 15Z/10 AM. CURULE FROM RUC MODEL SHOWS BROKEN CUMULUS CEILINGS NORTH AND SOUTH OF CENTRAL IL THIS AFTERNOON. HAVE VCSH AT PIA OVER IL RIVER VALLEY THIS AFTERNOON AFTER 18Z/1 PM BUT BETTER CHANCE OF CONVECTION WILL BE NW TOWARD IA. FEW TO SCATTERED CLOUDS LINGER TONIGHT. SOUTH WINDS 10-15 KTS WITH GUSTS AROUND 20 KTS AFTER 15Z/10 AM TODAY AND DIMINISH TO 5-10 KTS AFTER SUNSET. 07 && .PREV DISCUSSION... ISSUED 256 AM CDT FRI JUN 21 2013 QUIET SUMMER-LIKE WEATHER WILL PREVAIL FOR SEVERAL DAYS...WITH THE NEXT SIGNIFICANT CHANCE FOR RAIN HOLDING OFF UNTIL THE MIDDLE OF NEXT WEEK. SHORT TERM...TODAY THROUGH SUNDAY MCS CURRENTLY ACROSS MINNESOTA WILL TRACK E/SE INTO WISCONSIN THIS MORNING...REMAINING WELL NORTH OF CENTRAL ILLINOIS. FURTHER SOUTH BENEATH THE BUILDING UPPER-LEVEL RIDGE...A WEAK FRONTAL BOUNDARY IS SETTING OFF WIDELY SCATTERED SHOWERS/THUNDER ACROSS EASTERN IOWA AND WESTERN ILLINOIS. THINK THIS SUBTLE BOUNDARY WILL CONTINUE TO BE THE MAIN FOCUSING MECHANISM FOR ADDITIONAL CONVECTION THROUGHOUT THE DAY. DUE TO LACK OF UPPER SUPPORT AND WARMING MID-LEVELS BENEATH THE RIDGE...WIDESPREAD CONVECTION WILL REMAIN UNLIKELY. WILL CARRY 20 POPS ALONG AND WEST OF I-55 IN CLOSE PROXIMITY TO THE FRONT...WITH DRY WEATHER FURTHER EAST AND SOUTH. WILL BE A VERY WARM/HUMID DAY AS WELL...WITH AFTERNOON HIGHS REACHING THE LOWER 90S. MODELS CONTINUE TO SUGGEST ISOLATED DIURNAL CONVECTION WILL DEVELOP SATURDAY AFTERNOON...AS MID-LEVEL CAP REMAINS MARGINAL. WILL CONTINUE TO FEATURE SLIGHT CHANCE POPS ACCORDINGLY. AS CAP STRENGTHENS...SUNDAY LOOKS TO BE A SUNNY AND DRY DAY. MAIN STORY TODAY THROUGH SUNDAY WILL BE THE HEAT. HIGH TEMPS EACH DAY WILL RISE INTO THE LOWER 90S...WHILE OVERNIGHT LOWS ONLY DROP INTO THE LOWER 70S. THESE TEMPERATURES COMBINED WITH DEWPOINTS IN THE UPPER 60S AND LOWER 70S...WILL PRODUCE AFTERNOON HEAT INDEX READINGS OF 95 TO 100 DEGREES. LONG TERM...MONDAY THROUGH THURSDAY UPPER RIDGE WILL GRADUALLY RETROGRADE WESTWARD NEXT WEEK...WITH BOTH THE GFS AND ECMWF SHOWING RIDGE BUILDING OVER THE ROCKIES BY WEDNESDAY/THURSDAY. AS A RESULT...INCREASING NORTHWESTERLY FLOW DOWNSTREAM FROM THE RIDGE WILL PUSH A COLD FRONT INTO ILLINOIS BY THE MIDDLE OF THE WEEK. MODELS STILL EXHIBIT A BIT OF A SPREAD IN SOLUTIONS...BUT GENERAL CONSENSUS BRINGS FRONT INTO THE AREA BY WEDNESDAY NIGHT/THURSDAY. HAVE INTRODUCED CHANCE POPS ACROSS THE NORTHERN CWA ON WEDNESDAY...THEN EVERYWHERE WEDNESDAY NIGHT INTO THURSDAY. ONCE FRONT PASSES...COOLER AND LESS HUMID WEATHER WILL ARRIVE BY THE END OF NEXT WEEK. BARNES && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1000 AM CDT FRI JUN 21 2013 .MESOSCALE DISCUSSION... 1000 AM CDT COMPLEX OF STORMS CONTINUES TO EVOLVE ACROSS SOUTHERN WI/FAR NW IL/NE IA. LATEST RADAR TRENDS SHOW REFLECTIVITY WEAKENING TOWARD THE DBQ AREA WITH A MORE PERSISTENT LINE NOW SET UP FROM SOUTHERN CENTRAL WI BACK TO FREEPORT AND SAVANNA MOVING EASTWARD. THE ATMOSPHERE AHEAD OF THIS ACROSS THE LOCAL AREA IS STILL CAPPED AND THE COMPLEX IS BEGINNING TO OUTRUN BETTER DEEP LAYER SHEAR. SOME OUTFLOW IS PRESENT BASED ON SFC OBS SHIFTING WINDS TO THE NORTHWEST WITH SOME GUSTINESS BUT THE LINE MAY BE BECOMING ELEVATED. THAT SAID...WINDS SOUTH OF THE LINE HAVE TURNED MORE SOUTH-SOUTHWEST HELPING TO FEED SLIGHTLY HIGHER DEWPOINT AIR NORTHWARD. HOWEVER...IT DOES LOOK TO BE A FEW MORE HOURS BEFORE CAPPING CAN ERODE WHICH WOULD LIKELY BE TOO LATE TO INTERSECT WITH CURRENT STORMS. AT THIS POINT EXPECT THE BEST COVERAGE OF STORMS TO MOVE EAST OR EAST-SOUTHEAST ALONG A LINE FROM FREEPORT TO CHICAGO THOUGH THE SOUTHERN END OF THE LINE MAY BE MORE VARIABLE IN COVERAGE. HEAVY DOWNPOURS WILL OCCUR AND THE LATEST RADAR SCANS HAVE SHOWN A SLOWING TREND SO LOCALIZED FLOODING IS A THREAT WITH 1 INCH+ PER HOUR RAINFALL RATES LIKELY BASED ON UPSTREAM REPORTS. AN ISOLATED STRONG/SEVERE WIND THREAT EXISTS MAINLY IF CAPPING CAN ERODE. A BOUNDARY MAY LAY OUT ACROSS THE AREA THANKS TO THIS ACTIVITY LEADING TO AT LEAST A LOW CHANCE FOR NEW DEVELOPMENT LATER TODAY. MDB && .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * TS POTENTIAL TOWARD 17Z. * VARIABLE WIND DIRECTION POSSIBLE 17-18 OR 19Z THANKS TO TS ACTIVITY. MDB //DISCUSSION...UPDATED 14Z... COMPLEX OF TS CONTINUES TO MOVE SOUTH AND EAST ACROSS SW WI AND NE IA. BEST ESTIMATE IS THAT THE ACTIVITY WILL REMAIN MOST FOCUSED NORTH AND WEST OF THE TERMINALS THROUGH MIDDAY...BUT RFD WILL LIKELY SEE A PERIOD OF STORMS TOWARD 15-1530Z BRINGING A SHIFT TO NORTH OR NORTHWEST WINDS BEFORE THEY SHIFT BACK TO THE SOUTHEAST. WILL CONTINUE TO MONITOR TRENDS FOR DPA/ORD/MDW BUT THE FAVORED TIME OF ACTIVITY IS APPROX 17Z REGARDLESS OF COVERAGE/INTENSITY. THE COMPLEX CONTINUES TO EVOLVE WITH SOME DECAY OCCURRING NEAR DBQ. A DOMINANT LINE MAY RESULT THAT RIDES FROM FEP TO ORD/MDW WITH ANOTHER AREA REMAINING FOCUSED NEAR THE MS RIVER. ADDITIONAL TAF ADJUSTMENTS MAY BE NEEDED PRIOR TO 16Z. STORMS SHOULD LAST APPROX AN HOUR OR SO WITH SOME EMBEDDED TS BEHIND THE MAIN LINE LINGERING FOR ANOTHER HOUR OR TWO. LOW POTENTIAL FOR ADDITIONAL ACTIVITY CONTINUES LATER THIS AFTERNOON AND EVENING BUT PROB IS TOO LOW TO INCLUDE IN TAF FOR NOW. MDB FROM 12Z... LARGE COMPLEX OF THUNDERSTORMS OVER THE UPPER MIDWEST EARLY THIS MORNING WAS SLOWLY SLIDING SOUTHEAST. REGIONAL RADAR INDICATED A LINE OF THUNDERSTORMS STLL ASSOCIATED WITH THIS COMPLEX STRETCHING FROM FAR NORTHEAST IOWA INTO WEST CENTRAL WISCONSIN. GUIDANCE INDICATES THAT THIS LINE WILL BEGIN TO WEAKEN AS IT CONTINUES TO SLIDES SOUTHEAST. CURRENT THINKING IS THAT SOME REMNANTS OF THIS LINE OF THUNDERSTORMS MAY ARRIVE LATER THIS MORNING. THE TIMING WOULD BE INTO RFD ARND 16Z THEN FURTHER EAST AT ORD/MDW/DPA/GYY CLOSER TO 18Z ARRIVAL. WITH SOME HEATING AHEAD OF THIS LINE OVER NORTHERN IL/NORTHWEST IN AIRFIELDS...THIS MAY AID IN MAINTAINING THIS LINE OF CONVECTION. AT THIS TIME HAVE OPTED TO GO WITH A VCTS RATHER THAN A PREVAILING MENTION. BUT THAT MAY NEED TO BE CHANGED FOR THE 14Z AMD. SOUTHERLY WINDS WILL CONTINUE THRU MUCH OF THE DAY WITH OCCASIONAL GUSTS BEGINNING TO OCCUR LATER THIS MORNING TO AROUND 20 KT. CLOUD DECKS SHUD BE AROUND 5KFT AGL...AND MAY SLOWLY GROW IN COVERAGE THROUGHOUT THE AFT FROM A SCT TO BKN. GUIDANCE IS THEN REDEVELOPING A LINE OF SHOWERS/THUNDERSTORMS LATE THIS AFTN/EVE ALONG A REMNANT BOUNDARY FROM THIS MORNING CONVECTION. SOME OF THESE THUNDERSTORMS COULD BE STRONG TO SEVERE...WITH THE MAIN HAZARDS BEING WIND/HAIL. SOUTHERLY WINDS PERSIST OVERNIGHT AND DIMINISH TO ARND 10KT...WITH SOME TURNING TO THE SOUTHWEST EXPECTED OVERNIGHT TOWARDS DAYBREAK SAT. OVERALL EXPECT VFR CONDS THROUGHOUT...HOWEVER WITH ANY THUNDERSTORM ACTIVITY THIS COULD EASILY BE LIMITED TO MVFR. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM CONFIDENCE IN AT LEAST SOME TS ACTIVITY NEAR THE TERMINALS BY 17/18Z OR SO. * MEDIUM CONFIDENCE IN VARIABLE/ERRATIC WINDS DEVELOPING WITH TS ACTIVITY TOWARD 17/18Z MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. SUNDAY...MAINLY VFR. CHC THUNDERSTORMS LATE. MONDAY THROUGH THURSDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE VFR. BEACHLER && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
935 AM CDT FRI JUN 21 2013 .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * TS POTENTIAL TOWARD 17Z. * VARIABLE WIND DIRECTION POSSIBLE 17-18 OR 19Z THANKS TO TS ACTIVITY. MDB //DISCUSSION...UPDATED 14Z... COMPLEX OF TS CONTINUES TO MOVE SOUTH AND EAST ACROSS SW WI AND NE IA. BEST ESTIMATE IS THAT THE ACTIVITY WILL REMAIN MOST FOCUSED NORTH AND WEST OF THE TERMINALS THROUGH MIDDAY...BUT RFD WILL LIKELY SEE A PERIOD OF STORMS TOWARD 15-1530Z BRINGING A SHIFT TO NORTH OR NORTHWEST WINDS BEFORE THEY SHIFT BACK TO THE SOUTHEAST. WILL CONTINUE TO MONITOR TRENDS FOR DPA/ORD/MDW BUT THE FAVORED TIME OF ACTIVITY IS APPROX 17Z REGARDLESS OF COVERAGE/INTENSITY. THE COMPLEX CONTINUES TO EVOLVE WITH SOME DECAY OCCURRING NEAR DBQ. A DOMINANT LINE MAY RESULT THAT RIDES FROM FEP TO ORD/MDW WITH ANOTHER AREA REMAINING FOCUSED NEAR THE MS RIVER. ADDITIONAL TAF ADJUSTMENTS MAY BE NEEDED PRIOR TO 16Z. STORMS SHOULD LAST APPROX AN HOUR OR SO WITH SOME EMBEDDED TS BEHIND THE MAIN LINE LINGERING FOR ANOTHER HOUR OR TWO. LOW POTENTIAL FOR ADDITIONAL ACTIVITY CONTINUES LATER THIS AFTERNOON AND EVENING BUT PROB IS TOO LOW TO INCLUDE IN TAF FOR NOW. MDB FROM 12Z... LARGE COMPLEX OF THUNDERSTORMS OVER THE UPPER MIDWEST EARLY THIS MORNING WAS SLOWLY SLIDING SOUTHEAST. REGIONAL RADAR INDICATED A LINE OF THUNDERSTORMS STLL ASSOCIATED WITH THIS COMPLEX STRETCHING FROM FAR NORTHEAST IOWA INTO WEST CENTRAL WISCONSIN. GUIDANCE INDICATES THAT THIS LINE WILL BEGIN TO WEAKEN AS IT CONTINUES TO SLIDES SOUTHEAST. CURRENT THINKING IS THAT SOME REMNANTS OF THIS LINE OF THUNDERSTORMS MAY ARRIVE LATER THIS MORNING. THE TIMING WOULD BE INTO RFD ARND 16Z THEN FURTHER EAST AT ORD/MDW/DPA/GYY CLOSER TO 18Z ARRIVAL. WITH SOME HEATING AHEAD OF THIS LINE OVER NORTHERN IL/NORTHWEST IN AIRFIELDS...THIS MAY AID IN MAINTAINING THIS LINE OF CONVECTION. AT THIS TIME HAVE OPTED TO GO WITH A VCTS RATHER THAN A PREVAILING MENTION. BUT THAT MAY NEED TO BE CHANGED FOR THE 14Z AMD. SOUTHERLY WINDS WILL CONTINUE THRU MUCH OF THE DAY WITH OCCASIONAL GUSTS BEGINNING TO OCCUR LATER THIS MORNING TO AROUND 20 KT. CLOUD DECKS SHUD BE AROUND 5KFT AGL...AND MAY SLOWLY GROW IN COVERAGE THROUGHOUT THE AFT FROM A SCT TO BKN. GUIDANCE IS THEN REDEVELOPING A LINE OF SHOWERS/THUNDERSTORMS LATE THIS AFTN/EVE ALONG A REMNANT BOUNDARY FROM THIS MORNING CONVECTION. SOME OF THESE THUNDERSTORMS COULD BE STRONG TO SEVERE...WITH THE MAIN HAZARDS BEING WIND/HAIL. SOUTHERLY WINDS PERSIST OVERNIGHT AND DIMINISH TO ARND 10KT...WITH SOME TURNING TO THE SOUTHWEST EXPECTED OVERNIGHT TOWARDS DAYBREAK SAT. OVERALL EXPECT VFR CONDS THROUGHOUT...HOWEVER WITH ANY THUNDERSTORM ACTIVITY THIS COULD EASILY BE LIMITED TO MVFR. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM CONFIDENCE IN AT LEAST SOME TS ACTIVITY NEAR THE TERMINALS BY 17/18Z OR SO. * MEDIUM CONFIDENCE IN VARIABLE/ERRATIC WINDS DEVELOPING WITH TS ACTIVITY TOWARD 17/18Z MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. SUNDAY...MAINLY VFR. CHC THUNDERSTORMS LATE. MONDAY THROUGH THURSDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE VFR. BEACHLER && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
700 AM CDT FRI JUN 21 2013 .DISCUSSION... ISSUED 256 AM CDT FRI JUN 21 2013 QUIET SUMMER-LIKE WEATHER WILL PREVAIL FOR SEVERAL DAYS...WITH THE NEXT SIGNIFICANT CHANCE FOR RAIN HOLDING OFF UNTIL THE MIDDLE OF NEXT WEEK. SHORT TERM...TODAY THROUGH SUNDAY MCS CURRENTLY ACROSS MINNESOTA WILL TRACK E/SE INTO WISCONSIN THIS MORNING...REMAINING WELL NORTH OF CENTRAL ILLINOIS. FURTHER SOUTH BENEATH THE BUILDING UPPER-LEVEL RIDGE...A WEAK FRONTAL BOUNDARY IS SETTING OFF WIDELY SCATTERED SHOWERS/THUNDER ACROSS EASTERN IOWA AND WESTERN ILLINOIS. THINK THIS SUBTLE BOUNDARY WILL CONTINUE TO BE THE MAIN FOCUSING MECHANISM FOR ADDITIONAL CONVECTION THROUGHOUT THE DAY. DUE TO LACK OF UPPER SUPPORT AND WARMING MID-LEVELS BENEATH THE RIDGE...WIDESPREAD CONVECTION WILL REMAIN UNLIKELY. WILL CARRY 20 POPS ALONG AND WEST OF I-55 IN CLOSE PROXIMITY TO THE FRONT...WITH DRY WEATHER FURTHER EAST AND SOUTH. WILL BE A VERY WARM/HUMID DAY AS WELL...WITH AFTERNOON HIGHS REACHING THE LOWER 90S. MODELS CONTINUE TO SUGGEST ISOLATED DIURNAL CONVECTION WILL DEVELOP SATURDAY AFTERNOON...AS MID-LEVEL CAP REMAINS MARGINAL. WILL CONTINUE TO FEATURE SLIGHT CHANCE POPS ACCORDINGLY. AS CAP STRENGTHENS...SUNDAY LOOKS TO BE A SUNNY AND DRY DAY. MAIN STORY TODAY THROUGH SUNDAY WILL BE THE HEAT. HIGH TEMPS EACH DAY WILL RISE INTO THE LOWER 90S...WHILE OVERNIGHT LOWS ONLY DROP INTO THE LOWER 70S. THESE TEMPERATURES COMBINED WITH DEWPOINTS IN THE UPPER 60S AND LOWER 70S...WILL PRODUCE AFTERNOON HEAT INDEX READINGS OF 95 TO 100 DEGREES. LONG TERM...MONDAY THROUGH THURSDAY UPPER RIDGE WILL GRADUALLY RETROGRADE WESTWARD NEXT WEEK...WITH BOTH THE GFS AND ECMWF SHOWING RIDGE BUILDING OVER THE ROCKIES BY WEDNESDAY/THURSDAY. AS A RESULT...INCREASING NORTHWESTERLY FLOW DOWNSTREAM FROM THE RIDGE WILL PUSH A COLD FRONT INTO ILLINOIS BY THE MIDDLE OF THE WEEK. MODELS STILL EXHIBIT A BIT OF A SPREAD IN SOLUTIONS...BUT GENERAL CONSENSUS BRINGS FRONT INTO THE AREA BY WEDNESDAY NIGHT/THURSDAY. HAVE INTRODUCED CHANCE POPS ACROSS THE NORTHERN CWA ON WEDNESDAY...THEN EVERYWHERE WEDNESDAY NIGHT INTO THURSDAY. ONCE FRONT PASSES...COOLER AND LESS HUMID WEATHER WILL ARRIVE BY THE END OF NEXT WEEK. BARNES && .AVIATION... ISSUED 655 AM CDT FRI JUN 21 2013 1027 MB HIGH PRESSURE OFF THE MID ATLANTIC COAST AND RIDGING WESTWARD INTO THE OHIO VALLEY TO BE NEARLY STATIONARY INTO SAT MORNING WHILE 1003 MB LOW PRESSUE OVER EASTERN CO INTO SW NEBRASKA WITH FRONTAL BOUNDARY EXTENDING NE INTO SOUTHERN MN TO ALSO REMAIN IN PLACE NEXT 24 HOURS. VFR CONDITIONS SHOULD CONTINUE ACROSS THE CENTRAL IL TERMINAL AIRPORTS NEXT 24 HOURS THROUGH 12Z/7 AM SAT. SCATTERED TO BROKEN MID/HIGH CLOUDS TO SPREAD SE FROM THE IL RIVER ACROSS CENTRAL IL DURING TODAY AS SCATTERED CUMULUS CLOUDS WITH BASES OF 4-6K FT DEVELOP AFTER 15Z/10 AM. CURULE FROM RUC MODEL SHOWS BROKEN CUMULUS CEILINGS NORTH AND SOUTH OF CENTRAL IL THIS AFTERNOON. HAVE VCSH AT PIA OVER IL RIVER VALLEY THIS AFTERNOON AFTER 18Z/1 PM BUT BETTER CHANCE OF CONVECTION WILL BE NW TOWARD IA. FEW TO SCATTERED CLOUDS LINGER TONIGHT. SOUTH WINDS 10-15 KTS WITH GUSTS AROUND 20 KTS AFTER 15Z/10 AM TODAY AND DIMINISH TO 5-10 KTS AFTER SUNSET. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
637 AM CDT FRI JUN 21 2013 .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * SOUTH WINDS ARND 10 KT WITH OCCASIONAL GUSTS TO 20 KT THIS AFTN. * POSSIBLE REMNANTS OF THUNDERSTORMS ARRIVING AFT 17Z. THEN POSSIBLE REDEVELOPMENT OF THUNDERSTORMS LATE THIS AFTN/EVE. BEACHLER //DISCUSSION...UPDATED 12Z... LARGE COMPLEX OF THUNDERSTORMS OVER THE UPPER MIDWEST EARLY THIS MORNING WAS SLOWLY SLIDING SOUTHEAST. REGIONAL RADAR INDICATED A LINE OF THUNDERSTORMS STILL ASSOCIATED WITH THIS COMPLEX STRETCHING FROM FAR NORTHEAST IOWA INTO WEST CENTRAL WISCONSIN. GUIDANCE INDICATES THAT THIS LINE WILL BEGIN TO WEAKEN AS IT CONTINUES TO SLIDES SOUTHEAST. CURRENT THINKING IS THAT SOME REMNANTS OF THIS LINE OF THUNDERSTORMS MAY ARRIVE LATER THIS MORNING. THE TIMING WOULD BE INTO RFD ARND 16Z THEN FURTHER EAST AT ORD/MDW/DPA/GYY CLOSER TO 18Z ARRIVAL. WITH SOME HEATING AHEAD OF THIS LINE OVER NORTHERN IL/NORTHWEST IN AIRFIELDS...THIS MAY AID IN MAINTAINING THIS LINE OF CONVECTION. AT THIS TIME HAVE OPTED TO GO WITH A VCTS RATHER THAN A PREVAILING MENTION. BUT THAT MAY NEED TO BE CHANGED FOR THE 14Z AMD. SOUTHERLY WINDS WILL CONTINUE THRU MUCH OF THE DAY WITH OCCASIONAL GUSTS BEGINNING TO OCCUR LATER THIS MORNING TO AROUND 20 KT. CLOUD DECKS SHUD BE AROUND 5KFT AGL...AND MAY SLOWLY GROW IN COVERAGE THROUGHOUT THE AFT FROM A SCT TO BKN. GUIDANCE IS THEN REDEVELOPING A LINE OF SHOWERS/THUNDERSTORMS LATE THIS AFTN/EVE ALONG A REMNANT BOUNDARY FROM THIS MORNING CONVECTION. SOME OF THESE THUNDERSTORMS COULD BE STRONG TO SEVERE...WITH THE MAIN HAZARDS BEING WIND/HAIL. SOUTHERLY WINDS PERSIST OVERNIGHT AND DIMINISH TO ARND 10KT...WITH SOME TURNING TO THE SOUTHWEST EXPECTED OVERNIGHT TOWARDS DAYBREAK SAT. OVERALL EXPECT VFR CONDS THROUGHOUT...HOWEVER WITH ANY THUNDERSTORM ACTIVITY THIS COULD EASILY BE LIMITED TO MVFR. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS FORECAST. * HIGH CONFIDENCE IN OCCASIONAL THUNDERSTORMS. * LOW CONFIDENCE THAT THUNDERSTORMS WILL DIRECTLY IMPACT AIRFIELDS. * MEDIUM CONFIDENCE IN THUNDERSTORM TIMING. * MEDIUM CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. BEACHLER //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. SUNDAY...MAINLY VFR. CHC THUNDERSTORMS LATE. MONDAY THROUGH THURSDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE VFR. BEACHLER && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS DES MOINES IA
617 AM CDT FRI JUN 21 2013 .SHORT TERM.../TODAY/... ISSUED AT 331 AM CDT FRI JUN 21 2013 LARGE CONVECTIVE COMPLEX OVER MN BEGINNING TO TURN SOUTHEAST AND BATTLING H700 CAP AT THIS TIME AS IT DOES. CONTINUED CONCERNS EARLY THIS MORNING AS TO HOW FAR SOUTH THIS WILL TURN BEFORE THE CAP BECOMES TOO STRONG FOR ANY FURTHER SOUTH DRIFT. COLD POOL HAS DEVELOPED WITH SFC WINDS AND OUTFLOW PROPAGATING BACK TO THE SOUTHWEST. THIS SUGGESTS THAT IT MAY CLIP NORTHERN IOWA WITH STORMS THIS MORNING BETWEEN 4 AND 8 AM...IF THE LINE IS ABLE TO CONTINUE BREAKING THE CAP BACK TO THE SOUTHWEST...MAY SEE ADDITIONAL STORMS INTO CENTRAL IOWA. CURRENT MESO MODELS ARE LACKING IN ANY AGREEMENT BUT THE HRRR HAS BEEN MORE REALISTIC WITH FEATURES SO FAR AND IT ONLY SCRAPES NORTHERN IOWA EARLY TODAY WITH THIS COMPLEX OF STORMS. ONCE SYSTEM MOVES EAST WILL BE LEFT WITH ANOTHER VERY WARM AND HUMID DAY. THIS WILL RESULT IN HIGHS IN THE UPPER 80S TO LOWER 90S THIS AFTERNOON WITH SOUTH WINDS AND GENEROUS DEW POINTS IN THE 60S AND LOWER 70S. MORE CONVECTION MAY DEVELOP THIS AFTERNOON NORTH OF HIGHWAY 20 ALONG ANY LINGERING OUTFLOW BOUNDARY FROM THE OVERNIGHT CONVECTIVE COMPLEX AND THIS IS MORE LIKELY AFT 19Z THROUGH THE REMAINDER OF THE AFTERNOON. WILL BE MONITORING CONVECTIVE TRENDS THROUGH THE MORNING HOURS. .LONG TERM.../TONIGHT THROUGH THURSDAY/... ISSUED AT 331 AM CDT FRI JUN 21 2013 EXTENDED FORECAST CONTINUES TO CENTER AROUND LARGE UPPER LEVEL LOW ACROSS PAC NW...AND SURFACE LOW ACROSS NORTHERN PLAINS WITH WARM FRONT IN SOUTHERN SD/MN. THIS WILL CONTINUE TO BE THE FOCUS FOR AFTERNOON CONVECTION...AND MODELS AGAIN SUGGEST MCS DEVELOPMENT OVERNIGHT. HOWEVER..AS UPPER LOW PUSHES EASTWARD...RIDGE PUSHES NORTH OF IOWA...AND UPPER LEVEL FLOW IS EXPECTED TO TAKE ANY OVERNIGHT MCS NORTH OF IOWA. THOUGH...CURRENTLY ONGOING MCS ACROSS SOUTHERN MINNESOTA MAY PRODUCE AN OUTFLOW BOUNDARY INTO NORTHERN IOWA...WHICH MAY ALLOW FOR TRACK OF MCS TO BE FURTHER SOUTH INTO NORTHERN IOWA. THOUGH GIVEN STRENGTH OF UPPER LEVEL LOW...STILL PREFER NORTHERN SOLUTION...AND HAVE KEPT POPS CONFINED TO NORTHERN IOWA OVERNIGHT. SATURDAY NIGHT LOOKS TO BE ACTIVE AS WELL...WITH FRONTAL BOUNDARY PUSHING INTO NORTHWESTERN IOWA. THIS COULD BE FOCUS FOR AFTERNOON THUNDERSTORM DEVELOPMENT...WITH AGAIN OVERNIGHT MCS...THOUGH WITH INFLUENCE FROM UPPER LOW MODELS CONTINUE TO PULL CONVECTION NORTHWEST OF IOWA...AND HAVE KEPT POPS AGAIN CONFINED TO THE NORTH...AS WARM MID LEVEL TEMPS WILL HELP TO KEEP CAP ACROSS MOST OF CENTRAL IOWA. SUNDAY FRONTAL BOUNDARY WILL PUSH INTO CENTRAL IOWA...WITH ENOUGH FORCING TO LEAD TO PROLONGED PERIODS OF PRECIPITATION THROUGH THE DAY AND OVERNIGHT...THOUGH WILL PUSH EAST OF REGION BY MONDAY. SHORTWAVE PUSHING ACROSS NE/SD BORDER WILL BRING ADDITIONAL SHOT OF PRECIPITATION FOR TUESDAY...LINGERING IN THE EAST THROUGH WEDNESDAY. TEMPERATURES WILL BE HOT THROUGH THE BEGINNING OF THE PERIOD AS SOUTHERLY SURFACE FLOW AND WAA PERSISTS UNDER RIDGE. THIS WILL ALLOW TEMPERATURES TO CLIMB INTO THE 90S ACROSS MUCH OF THE CWA...THOUGH COULD GO HIGHER THAN GOING IF ABLE TO MIX WELL. HEAT INDEX VALUES WILL BE NEAR 100 THROUGH THE WEEKEND IN THE AFTERNOONS. THIS WILL BE THE FIRST EXPOSURE SUMMER LIKE HEAT/HUMIDITY FOR MUCH OF THE REGION...AND MAY BE TAXING. HOWEVER...OVERNIGHT TEMPERATURES EXPECTED TO COOL INTO THE 70S AND WILL PROVIDE SOME RELIEF. IN ADDITION...BEHIND FRONTAL BOUNDARY MONDAY TEMPERATURES WILL COOL SOMEWHAT...BUT WILL QUICKLY REBOUND BACK INTO THE UPPER 80S AND LOW 80S FOR MOST OF THE REMAINDER OF THE PERIOD. && .AVIATION...21/12Z ISSUED AT 617 AM CDT FRI JUN 21 2013 MAIN CONCERN WILL BE CONVECTION EARLY TODAY AND AGAIN THIS AFTERNOON AND NIGHT. AMBIENT WINDS WILL ALSO POSE SOME ISSUES AS GRADIENT REMAINS STRONG WITH SOUTH WINDS THROUGH THE DAY MIXING TO ABOUT 20 TO 25 KTS ACROSS THE REGION. OLD MCC IN MINNESOTA EARLY TODAY CONTINUES TO PUSH EAST WITH OUTFLOW BOUNDARY CONVECTION NOW ENTERING NORTHERN IOWA. THIS WILL MAINLY AFFECT KMCW EARLY TODAY AND POSSIBLY KALO TO A LESSER EXTENT. WINDS MAY PICK UP AS BOUNDARY INTERACTS WITH MORE UNSTABLE AIR THROUGH ABOUT 16Z AND WILL MONITOR FOR STRONG WIND GUST POTENTIAL AT KMCW AND KALO. ONCE CONVECTION PUSHES EAST... GRADIENT WINDS WILL INCREASE FROM THE SOUTH AFT 16Z. OLD OUTFLOW BOUNDARY MAY BE FOCUS FOR AFTERNOON CONVECTION NORTH SITES ONCE AGAIN BUT STRONG CAP AT H700 WILL INHIBIT ANY CONVECTION FOR KFOD KDSM...AND KOTM THROUGH REMAINDER OF PERIOD. AS NIGHTFALL APPROACHES ANOTHER ROUND OF CONVECTION MAY DEVELOP NORTH OF STATE AND AGAIN AFFECT NORTHERN SITES BETWEEN 04 AND 09Z ON THE 22ND. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...REV LONG TERM...AWB AVIATION...REV
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
930 AM MDT FRI JUN 21 2013 .UPDATE... AREA OF SEVERE THUNDERSTORMS THAT WAS OVER SE MT THIS MORNING HAS MOVED INTO THE DAKOTAS. RECEIVED REPORTS OF GOLF BALL SIZED HAIL AND FUNNEL CLOUDS FROM THE STORMS EARLIER THIS MORNING. MORE CONVECTION WAS MOVING INTO THIS AREA FROM NE WY ON RADAR. SHORTWAVES AND ISENTROPIC LIFT WILL PROVIDE LIFT TO SE MT...AND MID LEVEL LAPSE RATES WERE UNSTABLE. WHILE THE HRRR MOVES PRECIPITATION OUT OF THIS AREA THIS MORNING AND DOES NOT REGENERATE IT...PREFER THE SSEO WHICH DOES REDEVELOP CONVECTION OVER THIS AREA BY THIS EVENING. OTHER CONVECTION WILL DEVELOP ACROSS THE REGION UNDER THE ACTIVE SW FLOW ASSOCIATED WITH THE UPPER LOW AND IN THE RIGHT ENTRANCE REGION OF AN UPPER JET. AIRMASS ACROSS THE AREA WILL BE UNSTABLE WITH GOOD SHEAR. NOTED INVERTED-V SOUNDINGS FROM KMLS W AND HAVE ADDED MENTION OF SMALL HAIL AND GUSTY WINDS TO THE FORECAST. WILL CONTINUE THE SEVERE WORDING IN THE SE. OTHERWISE...LOWERED DEWPOINTS A BIT TODAY BASED ON CURRENT AND EXPECTED TRENDS. HIGH TEMPERATURES IN THE 60S AND 70S WERE ON TRACK PER EXPECTED MIXING. ARTHUR && .SHORT TERM...VALID FOR TDY AND SAT... SEVERAL OPPORTUNITIES FOR SHOWERS AND STORMS WILL EXIST DURING THE NEXT 36 HOURS AS THE UPPER-LEVEL TROUGH CENTERED OVER ID AT 09 UTC HEADS EAST. WHILE THE RESERVOIR OF STRONGEST INSTABILITY WILL STAY ANCHORED DOWNSTREAM IN THE DAKOTAS...ENOUGH INGREDIENTS WILL EXIST FOR SOME RISK OF SEVERE STORMS ACROSS PARTS OF OUR AREA TOO. EARLY THIS MORNING...ELEVATED CONVECTION FED ON A 30+ KT LOW-LEVEL JET HAS BEEN FORMING EAST OF BILLINGS SINCE ABOUT 06 UTC. INFRARED SATELLITE IMAGES SUGGEST ANOTHER SUBTLE SHORT WAVE IMPULSE LOCATED OVER CENTRAL AND NORTHEAST WY WILL MOVE INTO SOUTHEASTERN MT BY 12 UTC. THAT LENDS CREDENCE TO THE LAST SEVERAL HRRR RUNS AND SEVERAL OTHER HIGH-RESOLUTION...CONVECTION-ALLOWING MODEL SIMULATIONS FROM 00 UTC IN SHOWING ROBUST STORMS DEVELOPING BY MORNING FROM BROADUS AND EKALAKA TOWARD BAKER. FORECAST SOUNDINGS AND RAP ANALYSES SHOW MUCAPE ON THE ORDER OF 1000 J/KG...MID LEVEL LAPSE RATES OF 7 C/KM OR BETTER...AND EFFECTIVE SHEAR OF 60 KT IN SOUTHEASTERN MT DURING THE MORNING. THUS...SOME SEVERE HAIL IS POSSIBLE...AND WE ACTUALLY DECIDED TO MENTION THE RISK OF SEVERE STORMS EXPLICITLY WITHIN THE FORECAST DURING THE MORNING AT BROADUS...BAKER...AND EKALAKA. LATER TODAY...WE KEPT THE MENTION OF SEVERE STORMS IN SOUTHEASTERN MT...AND EXPANDED IT BACK WEST AS FAR AS SHERIDAN AND LODGE GRASS. THE WESTWARD EXTENSION OF THE SEVERE RISK WAS DONE LARGELY TO GIVE DUE RESPECT TO CALIBRATED SEVERE THUNDERSTORM PROBABILITIES OFF OF THE 21 UTC SREF...WHICH ARE FOCUSED IN THE SHERIDAN AREA BY THE 21 TO 00 UTC TIME FRAME. WE HAVE TO ADMIT THOUGH THAT CONFIDENCE WITH THIS EVENT REMAINS BELOW-NORMAL...AND EARLY-DAY CONVECTION WILL BE A PLAYER IN HOW THINGS EVOLVE LATER TOO. IF IT IS PERSISTENT...THE BOUNDARY LAYER MAY NOT DESTABILIZE ENOUGH FOR SURFACE-BASED STORMS BY LATE AFTERNOON. ON THE OTHER HAND...ENOUGH ELEVATED INSTABILITY EXISTS TO SUPPORT SEVERE HAIL EVEN IF CONVECTION JUST CONTINUES TO REGENERATE OVER SOUTHEASTERN MT THROUGH THE DAY. FINALLY...WE ALSO INCREASED POPS OVER SOUTH CENTRAL MT FROM LIVINGSTON TO BIG TIMBER AND HARLOWTON THIS AFTERNOON TOO WHERE A DIFFERENT WAVE WILL ALLOW AT LEAST WEAK AND SCATTERED SHOWERS AND STORMS TO FORM. TONIGHT...ONCE EVENING CONVECTION WINDS DOWN AND/OR MOVES OFF INTO THE DAKOTAS...WE MIGHT HAVE A BIT OF A BREAK IN PRECIPITATION. THE 00 UTC ECMWF SUGGESTS ANOTHER WEAK SHORT WAVE TROUGH WILL GENERATE MORE SHOWERS OR STORMS OVER SOUTHEASTERN MT TOWARD DAYBREAK THOUGH AND THAT IS A GOOD EXAMPLE OF WHY CHANCE POPS REMAIN NECESSARY FOR MOST AREAS IN THE 06 TO 12 UTC TIME FRAME. SAT...THE 500-HPA TROUGH AXIS IS EXPECTED TO SWEEP ACROSS THE AREA DURING THE AFTERNOON AND EVENING. STRONG QG-FORCING CONCOMITANT TO THAT TROUGH AND INSTABILITY AHEAD OF THE 500-HPA COLD POOL WILL BE SUFFICIENT TO GENERATE A HEALTHY BATCH OF CONVECTION. WE INCREASED POPS INTO THE CATEGORICAL /80 PERCENT/ RANGE ALONG AND EAST OF THE BILLINGS TO SHERIDAN LINE TO REFLECT THE LIKELIHOOD FOR AT LEAST A PERIOD OF STORMS AHEAD OF THE TROUGH. THAT MOVE HAS STRONG SUPPORT FROM THE 00 UTC MULTI-MODEL CONSENSUS. WE WILL ACTUALLY HAVE A LOW RISK OF SEVERE STORMS AGAIN TOO...ESPECIALLY IF STORMS ARE ABLE TO GET FAR ENOUGH AHEAD OF THE MID-LEVEL TROUGH AXIS...WHERE THEY MAY HAVE ACCESS TO STRONGER EFFECTIVE SHEAR. SCHULTZ .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... THE EARLY PART OF THE EXTENDED FORECAST LOOKS UNSETTLED WITH A DRYING AND WARMING TREND FROM WEDNESDAY ONWARD. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE MONDAY AND TUESDAY AS SOUTHWEST FLOW OPENS UP AGAIN AND PROVIDES SEVERAL SHORTWAVES AND DEEPENING MOISTURE. RAISED POPS FOR TUESDAY AS MODELS HAVE SLOWED DOWN A BIT ON BUILDING THE RIDGE NOW UNTIL WEDNESDAY. MODELS WERE CONSISTENT IN BUILDING A STRONG RIDGE INTO THE NORTHERN ROCKIES WEDNESDAY INTO FRIDAY. THE GFS ACTUALLY HAS A 594DM HEIGHT LINE WORKING INTO SOUTHWEST MONTANA FRIDAY. THAT WOULD LEAD TO A WARM AND MAINLY DRY FORECAST. WILL HAVE TO WATCH FOR RIDGE RIDING SHORTWAVES FOR ISOLATED CONVECTION...BUT AT THIS TIME THE MODELS WERE DRY WITH THE MID LEVEL FLOW. TWH && .AVIATION... SHOWERS AND THUNDERSTORMS WILL DEVELOP WEST OF KBIL BY LATE THIS MORNING AND MOVE EAST DURING THE AFTERNOON. THUNDERSTORMS WILL BE LIKELY THROUGHOUT THE DAY ACROSS SOUTHEAST MONTANA WITH SOME THUNDERSTORMS CONTAINING HEAVY RAIN AND LARGE HAIL. LOCAL MVFR TO IFR CONDITIONS CAN BE EXPECTED IN AND NEAR THE THUNDERSTORM ACTIVITY. OTHERWISE...VFR CONDITIONS WILL PREVAIL ACROSS THE FORECAST AREA. THE MOUNTAINS WILL BE OBSCURED AT TIMES. HOOLEY && .PRELIMINARY POINT TEMP/POPS... TDY SAT SUN MON TUE WED THU ------------------------------------------------------- BIL 073 052/068 049/078 054/083 058/084 057/083 057/084 5/T 38/T 61/B 11/B 23/T 31/B 10/U LVM 069 043/066 044/079 046/083 051/083 052/086 051/087 6/T 57/T 51/B 12/T 23/T 31/B 11/U HDN 075 051/070 048/078 052/083 054/085 056/084 058/085 5/T 38/T 61/B 11/B 22/T 21/B 10/U MLS 076 056/072 053/080 056/084 059/085 059/086 057/086 5/T 58/T 82/T 12/T 22/T 21/B 11/U 4BQ 075 054/071 051/079 054/085 057/086 057/087 058/088 6/T 68/T 82/T 12/T 22/T 21/U 11/U BHK 074 055/069 052/076 054/085 059/084 060/086 057/082 7/T 67/T 82/T 12/T 33/T 21/B 11/U SHR 075 050/069 045/076 049/082 052/084 051/085 052/084 5/T 48/T 61/B 11/B 22/T 21/B 00/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1103 AM CDT FRI JUN 21 2013 .UPDATE... ISSUED AT 1100 AM CDT FRI JUN 21 2013 WILL ALLOW THE DENSE FOG ADVISORY TO EXPIRE AT 11 AM CDT. VISIBILITIES CONTINUE TO IMPROVE ACROSS WEST AND CENTRAL NORTH DAKOTA. PATCHY AREAS OF FOG MAY LINGER INTO THE AFTERNOON SOME LOCATIONS WITH VERY HIGH BOUNDARY LAYER MOISTURE IN PLACE...WITH SURFACE DEWPOINTS IN THE 60S TO EVEN AROUND 70F SOME LOCATIONS. LATEST RAP (13Z AND 14Z RUNS) SEEMS TO BE DOING THE BEST SO FAR WITH CURRENT SHOWERS AND STORMS...WEST AND SOUTH WITH THE HEAVIER ECHOS SOUTHWEST OVER ADAMS AND HETTINGER COUNTIES. SKIES SHOULD REMAIN MAINLY CLOUDY THROUGHOUT THE DAY ALONG WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...SOME SEVERE...WITH NUMEROUS EMBEDDED WAVES LIFTING ACROSS THE DAKOTAS. BEST CHANCE FOR WIDESPREAD CONVECTION WITH SEVERE WEATHER AND HEAVY RAIN WILL BE MID/LATE AFTERNOON INTO THIS EVENING WITH PEAK HEATING AND INSTABILITY MAXIMIZED. MODELS ARE KEYING IN ON CONVECTION FIRING UP ACROSS SOUTH DAKOTA LIFTING NORTH AND EAST TODAY INTO THIS EVENING...WITH A DRY/QUIET PERIOD IN THE WAKE OF THIS ACTIVITY LATE TONIGHT. WITH RICH BOUNDARY LAYER MOISTURE REMAINING IN PLACE...REDEVELOPMENT OF FOG AND STRATUS IS LOOKING LIKELY ONCE SKIES TREND SCT-SKC. UPDATE ISSUED AT 908 AM CDT FRI JUN 21 2013 MAIN UPDATE WAS TO EXTEND THE DENSE FOG ADVISORY UNTIL 11 AM CDT WITH SEVERAL AREA OBSERVING SITES REPORTING 1/4 MILE OR LESS STILL. UPDATE ISSUED AT 618 AM CDT FRI JUN 21 2013 UPDATE TO ISSUE DENSE FOG ADVISORY FOR PORTIONS OF THE FORECAST AREA AS OBS/WEBCAMS/SPOTTER REPORTS INDICATING DENSE FOG COVERAGE IS NOW SIGNIFICANT...AND WARRANTS HEADLINES. ALSO INCREASED POPS SLIGHTLY FAR WEST PER LATEST RADAR TRENDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 402 AM CDT FRI JUN 21 2013 THE HIGHLIGHT OF THE SHORT TERM IS SEVERE CONVECTIVE POTENTIAL THIS AFTERNOON THROUGH TONIGHT. THE MAIN QUESTION IS HOW QUICKLY CAPPING WILL BE ERODED TO ALLOW FOR SURFACE BASED CONVECTION THIS AFTERNOON. THE 00 UTC NAM/GFS BUFR SOUNDINGS DO VARY SIGNIFICANTLY IN REGARDS TO THE STRENGTH OF THIS CAPPING...WITH THE GFS HOLDING A STRONG CAP THROUGH THE AFTERNOON...WITH THE NAM SHOWING LITTLE CONVECTIVE INHIBITION BY 18 UTC. THE 03 UTC SREF SOUNDINGS DO SHOW WEAKER CAPPING THAN THE GFS...HOWEVER...THE 00 UTC 4 KM WRF HAS LITTLE AFTERNOON CONVECTION ACROSS THE AREA. THUS...DID LIMIT POPS TO SLIGHT CHANCE OR CHANCE PRIOR TO 00 UTC. SHOULD CAPPING BE ERODED...ML CAPE VALUES OF 2500-3500 J/KG WITH 50 KTS OF DEEP LAYER SHEAR ARE AVAILABLE...WITH VERY LARGE HAIL POSSIBLE GIVEN -10 TO -30 C CAPE VALUES NEAR 1000 J/KG. THE BETTER CHANCES FOR THUNDERSTORMS ARE THIS EVENING AND TONIGHT WITH A POTENTIAL MCS PROPAGATING OUT OF SOUTH DAKOTA WITH THE ARRIVAL OF GREATER UPPER LEVEL FORCING. IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...HEAVY RAINFALL WILL BECOME AN INCREASING THREAT...ESPECIALLY FOR THOSE AREAS IMPACTED BY HEAVY RAINFALL WEDNESDAY AND THURSDAY...WITH PWATS 1.50 INCHES AND K INDEX VALUES OF 35-40 C. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 402 AM CDT FRI JUN 21 2013 THE MAIN FORECAST CONCERNS DURING THE LONG TERM PERIOD ARE THE POTENTIAL FOR CONTINUED HEAVY RAIN AND FLASH FLOODING OVER THE WEEKEND. MODEL CONSENSUS INDICATES AN UPPER TROUGH MOVING INTO THE NORTHERN PLAINS SATURDAY AND SATURDAY NIGHT. BROAD SYNOPTIC LIFT WILL SUPPORT WIDESPREAD SHOWERS AND THUNDERSTORMS...ESPECIALLY LATER IN THE DAY. THE JAMES RIVER VALLEY WILL AGAIN BE UNDER THE GUN FOR ADDITIONAL FLOODING...ALONG WITH ISOLATED SEVERE STORMS. BY SUNDAY...THE UPPER LOW WILL LIFT NORTH WITH THE FOCUS OF SHOWERS AND STORMS ACROSS THE NORTHERN COUNTIES...WHICH WILL DIMINISH SUNDAY NIGHT. SOUTHWEST FLOW WILL PERSIST MONDAY AND TUESDAY WITH RAIN EXPECTED TO BE MORE SCATTERED ACROSS THE STATE. BY THURSDAY...AN UPPER RIDGE WILL BEGIN TO SPREAD INTO WESTERN NORTH DAKOTA. CLOUDS WILL KEEP AFTERNOON TEMPS DOWN MAINLY IN THE 70S OVER THE WEEKEND...FOLLOWED BY NEAR TO SLIGHTLY ABOVE NORMAL TEMPS IN THE LOW 80S BY EARLY TO MID WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1100 AM CDT FRI JUN 21 2013 PATCHY FOG AND STRATUS WILL CONTINUE ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA GIVEN THE HUMID AIRMASS IN PLACE...WITH MVFR TO IFR CONDITIONS EXPECTED AT TIMES. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON...WITH A GREATER CHANCE FOR THUNDERSTORMS AFTER 22 UTC FRIDAY AFTERNOON MOVING FROM SOUTH TO NORTH THROUGH FRIDAY EVENING. && .HYDROLOGY... ISSUED AT 402 AM CDT FRI JUN 21 2013 EXPANDED THE FLASH FLOOD WATCH INTO EMMONS COUNTY GIVEN THE SIGNIFICANT RAINFALL THAT OCCURRED THURSDAY EVENING. MULTIPLE ROUNDS OF STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED FRIDAY THROUGH SUNDAY...WITH ADDITIONAL HEAVY RAINFALL POSSIBLE FOR THOSE LOCATIONS THAT HAVE SEEN SIGNIFICANT RAINFALL AMOUNTS WEDNESDAY NIGHT AND THURSDAY EVENING ACROSS SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY. SOILS HAVE LITTLE TO NO CAPACITY TO HOLD ADDITIONAL WATER...ENHANCING RUNOFF AND THE POTENTIAL TO AGGRAVATE THE ONGOING OVERLAND FLOODING ACROSS THE AREA. A COMPLEX OF THUNDERSTORMS WITH HEAVY RAINFALL IS EXPECTED FRIDAY EVENING AND NIGHT...AND AGAIN SATURDAY NIGHT INTO SUNDAY. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE WITH LOCALLY HIGHER AMOUNTS. && .BIS WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR NDZ023-025-036-037- 046>048-050-051. && $$ UPDATE...NH LONG TERM...RP KINNEY AVIATION...NH
AREA FORECAST DISCUSSION
NWS NORMAN OK
1036 AM CDT FRI JUN 21 2013 .DISCUSSION... WEAK ECHOES OVER THE PANHANDLES CONTINUE ON RADARS...BUT THERE IS LITTLE OR NO ACTUAL PRECIPITATION HITTING THE GROUND...AND EASTWARD PROGRESS HAS BEEN VERY SLOW. OUR EXISTING 10-15 PERCENT POPS IN FAR NORTHWEST OKLAHOMA ARE PROBABLY A BIT OPTIMISTIC...BUT DO SEEM REASONABLE AT THIS POINT. SHORT-RANGE MODELS STILL SHOW ISOLATED OR SCATTERED CONVECTION DEVELOPING THIS AFTERNOON OVER SOUTHWEST OKLAHOMA. THE EXISTING POPS AGAIN LOOK REASONABLE FOR NOW. AS MENTIONED PREVIOUSLY...ANY STORMS THAT DEVELOP IN THIS ENVIRONMENT WILL BE PULSE STORMS...WITH RAPID DEVELOPMENT...SHORT DURATION...AND THE POTENTIAL FOR STRONG WINDS AND HEAVY RAIN. OTHERWISE...TODAY WILL BE ANOTHER WARM...HUMID...AND BREEZY DAY ACROSS OKLAHOMA AND NORTH TEXAS. NO CHANGES TO THE CURRENT FORECAST ARE PLANNED FOR THIS MORNING. && .PREV DISCUSSION... /ISSUED 658 AM CDT FRI JUN 21 2013/ UPDATE... REDUCED RAIN CHANCES THIS MORNING ACROSS NORTHWEST OKLAHOMA. ADDED 10 PERCENT ISOLATED MENTION ACROSS LOCATIONS SOUTHWEST OF A ENID TO STILLWATER LINE THIS AFTERNOON. DISCUSSION... CONVECTION OVER NORTHWEST OKLAHOMA HAS DISSIPATED THIS MORNING...BUT MAY REDEVELOP OVER THE NEXT FEW HOURS. LATEST HRRR RUNS HAVE BEEN CONSISTENT IN DEVELOPING A FEW STORMS NEAR A VERNON TO LAWTON TO OKLAHOMA CITY LINE BETWEEN 1 AND 5 PM THIS AFTERNOON. THUS...ADDED A 10 PERCENT ISOLATED MENTION IN THESE LOCATIONS. IF THESE STORMS DEVELOP... THEY COULD BE STRONG WITH GUSTY WINDS AND LOCALLY HEAVY RAINFALL AS THEY WOULD BE SLOW MOVERS AND PULSE IN NATURE. PRODUCTS HAVE BEEN UPDATED. MBS PREV DISCUSSION... /ISSUED 622 AM CDT FRI JUN 21 2013/ DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. SOUTH WINDS WILL INCREASE AND BECOME GUSTY AT ALL SITES BY 15Z...THEN BE SLOW TO DIMINISH AFTER 01Z ACROSS WESTERN OKLAHOMA. MVFR CEILINGS SHOULD STAY JUST SOUTH OF KSPS-KMLC AND DISSIPATE BY 18Z. CHANCES FOR TSRA AND NON CONVECTIVE LOW LEVEL WIND SHEAR APPEAR TO BE TOO LOW TO MENTION. MBS PREV DISCUSSION... /ISSUED 357 AM CDT FRI JUN 21 2013/ DISCUSSION... HOT AND MAINLY RAINFREE WEATHER WILL BE THE MAIN STORY OVER THE NEXT SEVERAL DAYS. THIS MORNING...A FEW HIGH BASED THUNDERSTORMS WILL CONTINUE OVER FAR NORTHWEST OKLAHOMA...MAINLY NORTHWEST OF A CHEYENNE TO ALVA LINE. NO SEVERE STORMS ARE EXPECTED. KEPT 10-30 PERCENT...ISOLATED TO SCATTERED COVERAGE MENTION THIS MORNING IN THESE AREAS...THOUGH THESE STORMS MAY DISSIPATE QUICKLY OVER THE NEXT HOUR OR TWO. THIS AFTERNOON AND EARLY THIS EVENING...GENERALLY EXPECT ANOTHER HOT AND DRY DAY. SOME LATEST HRRR GUIDANCE HINTED THAT ISOLATED TO SCATTERED STORMS MAY DEVELOP NEAR A VERNON TO LAWTON TO OKLAHOMA CITY LINE BETWEEN 1 AND 5 PM...WEAKENING TOWARDS SUNSET. THE ONLY NOTICEABLE TRIGGER FOR LIFT WOULD BE A WEAK SHORT WAVE/POSSIBLE MCV CURRENTLY NEAR LUBBOCK TEXAS. CHANCES OF STORMS DEVELOPING SEEM TOO LOW TO MENTION AT THIS TIME DUE TO STRONG CAPPING...THOUGH WILL CLOSELY MONITOR. IF STORMS DEVELOP...A FEW PULSE MICROBURSTS WITH GUSTY WINDS AND LOCALLY HEAVY RAIN WOULD BE POSSIBLE AS THE AIR WILL BE UNSTABLE. LATER TONIGHT THROUGH THURSDAY...GENERALLY HOT AND RAINFREE WEATHER WILL CONTINUE. LIKE YESTERDAY EVENING...A FEW STORMS MAY MOVE INTO FAR WESTERN OR NORTHWESTERN OKLAHOMA EACH NIGHT...BUT ODDS ARE GOOD THAT MOST LOCATIONS WILL STAY DRY. THINK HIGHS WILL INCREASE SLIGHTLY EACH DAY...ESPECIALLY AS THE GROUND DRIES OUT. A WEAK FRONT MAY MAKE IT TOWARDS THE AREA LATE WEDNESDAY INTO THURSDAY WHICH COULD BRING A BIT HIGHER RAIN CHANCES TO THE AREA. FOR NOW...KEPT RAIN CHANCES BELOW 20 PERCENT DURING THIS TIME FRAME. TEMPERATURES WILL GENERALLY BE 5 TO 10 DEGREES ABOVE AVERAGE. WEDNESDAY MAY BE THE HOTTEST DAY WITH TRIPLE DIGIT HEAT ACROSS MUCH OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 94 72 95 72 / 10 10 0 10 HOBART OK 97 71 100 71 / 20 10 0 10 WICHITA FALLS TX 98 72 99 72 / 10 10 0 0 GAGE OK 96 70 97 70 / 10 10 10 10 PONCA CITY OK 94 72 95 72 / 10 10 10 10 DURANT OK 93 72 94 72 / 10 0 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 23/84
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
658 AM CDT FRI JUN 21 2013 .UPDATE... REDUCED RAIN CHANCES THIS MORNING ACROSS NORTHWEST OKLAHOMA. ADDED 10 PERCENT ISOLATED MENTION ACROSS LOCATIONS SOUTHWEST OF A ENID TO STILLWATER LINE THIS AFTERNOON. && .DISCUSSION... CONVECTION OVER NORTHWEST OKLAHOMA HAS DISSIPATED THIS MORNING...BUT MAY REDEVELOP OVER THE NEXT FEW HOURS. LATEST HRRR RUNS HAVE BEEN CONSISTENT IN DEVELOPING A FEW STORMS NEAR A VERNON TO LAWTON TO OKLAHOMA CITY LINE BETWEEN 1 AND 5 PM THIS AFTERNOON. THUS...ADDED A 10 PERCENT ISOLATED MENTION IN THESE LOCATIONS. IF THESE STORMS DEVELOP... THEY COULD BE STRONG WITH GUSTY WINDS AND LOCALLY HEAVY RAINFALL AS THEY WOULD BE SLOW MOVERS AND PULSE IN NATURE. PRODUCTS HAVE BEEN UPDATED. MBS && .PREV DISCUSSION... /ISSUED 622 AM CDT FRI JUN 21 2013/ DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. SOUTH WINDS WILL INCREASE AND BECOME GUSTY AT ALL SITES BY 15Z...THEN BE SLOW TO DIMINISH AFTER 01Z ACROSS WESTERN OKLAHOMA. MVFR CEILINGS SHOULD STAY JUST SOUTH OF KSPS-KMLC AND DISSIPATE BY 18Z. CHANCES FOR TSRA AND NON CONVECTIVE LOW LEVEL WIND SHEAR APPEAR TO BE TOO LOW TO MENTION. MBS PREV DISCUSSION... /ISSUED 357 AM CDT FRI JUN 21 2013/ DISCUSSION... HOT AND MAINLY RAINFREE WEATHER WILL BE THE MAIN STORY OVER THE NEXT SEVERAL DAYS. THIS MORNING...A FEW HIGH BASED THUNDERSTORMS WILL CONTINUE OVER FAR NORTHWEST OKLAHOMA...MAINLY NORTHWEST OF A CHEYENNE TO ALVA LINE. NO SEVERE STORMS ARE EXPECTED. KEPT 10-30 PERCENT...ISOLATED TO SCATTERED COVERAGE MENTION THIS MORNING IN THESE AREAS...THOUGH THESE STORMS MAY DISSIPATE QUICKLY OVER THE NEXT HOUR OR TWO. THIS AFTERNOON AND EARLY THIS EVENING...GENERALLY EXPECT ANOTHER HOT AND DRY DAY. SOME LATEST HRRR GUIDANCE HINTED THAT ISOLATED TO SCATTERED STORMS MAY DEVELOP NEAR A VERNON TO LAWTON TO OKLAHOMA CITY LINE BETWEEN 1 AND 5 PM...WEAKENING TOWARDS SUNSET. THE ONLY NOTICEABLE TRIGGER FOR LIFT WOULD BE A WEAK SHORT WAVE/POSSIBLE MCV CURRENTLY NEAR LUBBOCK TEXAS. CHANCES OF STORMS DEVELOPING SEEM TOO LOW TO MENTION AT THIS TIME DUE TO STRONG CAPPING...THOUGH WILL CLOSELY MONITOR. IF STORMS DEVELOP...A FEW PULSE MICROBURSTS WITH GUSTY WINDS AND LOCALLY HEAVY RAIN WOULD BE POSSIBLE AS THE AIR WILL BE UNSTABLE. LATER TONIGHT THROUGH THURSDAY...GENERALLY HOT AND RAINFREE WEATHER WILL CONTINUE. LIKE YESTERDAY EVENING...A FEW STORMS MAY MOVE INTO FAR WESTERN OR NORTHWESTERN OKLAHOMA EACH NIGHT...BUT ODDS ARE GOOD THAT MOST LOCATIONS WILL STAY DRY. THINK HIGHS WILL INCREASE SLIGHTLY EACH DAY...ESPECIALLY AS THE GROUND DRIES OUT. A WEAK FRONT MAY MAKE IT TOWARDS THE AREA LATE WEDNESDAY INTO THURSDAY WHICH COULD BRING A BIT HIGHER RAIN CHANCES TO THE AREA. FOR NOW...KEPT RAIN CHANCES BELOW 20 PERCENT DURING THIS TIME FRAME. TEMPERATURES WILL GENERALLY BE 5 TO 10 DEGREES ABOVE AVERAGE. WEDNESDAY MAY BE THE HOTTEST DAY WITH TRIPLE DIGIT HEAT ACROSS MUCH OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 94 72 95 72 / 10 10 0 10 HOBART OK 97 71 100 71 / 20 10 0 10 WICHITA FALLS TX 98 72 99 72 / 10 10 0 0 GAGE OK 96 70 97 70 / 10 10 10 10 PONCA CITY OK 94 72 95 72 / 10 10 10 10 DURANT OK 93 72 94 72 / 10 0 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 03/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
622 AM CDT FRI JUN 21 2013 .DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. && .AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. SOUTH WINDS WILL INCREASE AND BECOME GUSTY AT ALL SITES BY 15Z...THEN BE SLOW TO DIMINISH AFTER 01Z ACROSS WESTERN OKLAHOMA. MVFR CEILINGS SHOULD STAY JUST SOUTH OF KSPS-KMLC AND DISSIPATE BY 18Z. CHANCES FOR TSRA AND NON CONVECTIVE LOW LEVEL WIND SHEAR APPEAR TO BE TOO LOW TO MENTION. MBS && .PREV DISCUSSION... /ISSUED 357 AM CDT FRI JUN 21 2013/ DISCUSSION... HOT AND MAINLY RAINFREE WEATHER WILL BE THE MAIN STORY OVER THE NEXT SEVERAL DAYS. THIS MORNING...A FEW HIGH BASED THUNDERSTORMS WILL CONTINUE OVER FAR NORTHWEST OKLAHOMA...MAINLY NORTHWEST OF A CHEYENNE TO ALVA LINE. NO SEVERE STORMS ARE EXPECTED. KEPT 10-30 PERCENT...ISOLATED TO SCATTERED COVERAGE MENTION THIS MORNING IN THESE AREAS...THOUGH THESE STORMS MAY DISSIPATE QUICKLY OVER THE NEXT HOUR OR TWO. THIS AFTERNOON AND EARLY THIS EVENING...GENERALLY EXPECT ANOTHER HOT AND DRY DAY. SOME LATEST HRRR GUIDANCE HINTED THAT ISOLATED TO SCATTERED STORMS MAY DEVELOP NEAR A VERNON TO LAWTON TO OKLAHOMA CITY LINE BETWEEN 1 AND 5 PM...WEAKENING TOWARDS SUNSET. THE ONLY NOTICEABLE TRIGGER FOR LIFT WOULD BE A WEAK SHORT WAVE/POSSIBLE MCV CURRENTLY NEAR LUBBOCK TEXAS. CHANCES OF STORMS DEVELOPING SEEM TOO LOW TO MENTION AT THIS TIME DUE TO STRONG CAPPING...THOUGH WILL CLOSELY MONITOR. IF STORMS DEVELOP...A FEW PULSE MICROBURSTS WITH GUSTY WINDS AND LOCALLY HEAVY RAIN WOULD BE POSSIBLE AS THE AIR WILL BE UNSTABLE. LATER TONIGHT THROUGH THURSDAY...GENERALLY HOT AND RAINFREE WEATHER WILL CONTINUE. LIKE YESTERDAY EVENING...A FEW STORMS MAY MOVE INTO FAR WESTERN OR NORTHWESTERN OKLAHOMA EACH NIGHT...BUT ODDS ARE GOOD THAT MOST LOCATIONS WILL STAY DRY. THINK HIGHS WILL INCREASE SLIGHTLY EACH DAY...ESPECIALLY AS THE GROUND DRIES OUT. A WEAK FRONT MAY MAKE IT TOWARDS THE AREA LATE WEDNESDAY INTO THURSDAY WHICH COULD BRING A BIT HIGHER RAIN CHANCES TO THE AREA. FOR NOW...KEPT RAIN CHANCES BELOW 20 PERCENT DURING THIS TIME FRAME. TEMPERATURES WILL GENERALLY BE 5 TO 10 DEGREES ABOVE AVERAGE. WEDNESDAY MAY BE THE HOTTEST DAY WITH TRIPLE DIGIT HEAT ACROSS MUCH OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 94 72 95 72 / 10 10 0 10 HOBART OK 97 71 100 71 / 10 10 0 10 WICHITA FALLS TX 98 72 99 72 / 10 10 0 0 GAGE OK 96 70 97 70 / 10 10 10 10 PONCA CITY OK 94 72 95 72 / 0 10 10 10 DURANT OK 93 72 94 72 / 0 0 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 03/17/17
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1059 AM CDT FRI JUN 21 2013 .UPDATE... MINOR UPDATE TO EXPAND POPS TO INCLUDE THE EASTERN ZONES THIS AFTERNOON. ALSO CHANGED BLOWING DUST MENTION FROM PATCHY TO AREAS ON MUCH OF THE CAPROCK INTO THE WESTERN ROLLING PLAINS FOR THIS AFTERNOON INTO THE EVENING HOURS. MORNING WATER VAPOR IMAGERY SHOWS SOUTHWESTERLY FLOW ALOFT OVER THE REGION...WITH A RIBBON OF MID-LEVEL MOISTURE STRETCHING FROM KANSAS SOUTHWARD THROUGH OKLAHOMA...THE EASTERN PANHANDLES AND THROUGH THE EASTERN 1/2 OF THE CWA THEN TO POINTS SOUTH AND SOUTHWEST. THIS SUB-TROPICAL MOISTURE FETCH WAS IN ADVANCE OF A EAST-NORTHEASTWARD MOVING SHORTWAVE TROUGH THAT HAS ALREADY AIDED IN A FEW SHOWERS/STORMS ACROSS THE CENTRAL PANHANDLE THIS MORNING. RECENT HRRR AND RAP GUIDANCE INDICATE SAID FACTORS WILL BE ENOUGH TO DEVELOP ISOLATED TO SCATTERED MOIST CONVECTION OFF THE CAPROCK THIS AFTERNOON AND FOR THIS REASON HAVE INSERTED A SLIGHT CHANCE OF STORMS THERE AFTER 18Z. FURTHER WEST...DRIER MID-LEVEL AIR IS WORKING INTO THE REGION...BUT THE SFC TROUGH AND STRONG HEATING SHOULD BE ENOUGH TO POP ADDITIONAL ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON SOMEWHERE NEAR OR JUST WEST OF THE TX/NM LINE...WHICH WILL MOVE EASTWARD THROUGH THE EVENING HOURS WHILE GRADUALLY WANING IN INTENSITY. FAIRLY STRONG INSTABILITY /SBCAPES PUSHING 2000 J/KG/ AND MODEST DEEP LAYER SHEAR /GENERALLY AOB 35 KNOTS/ COULD SUPPORT A FEW STRONG/SEVERE CELLS...THOUGH OVERALL STORM ORGANIZATION WILL LIKELY BE LIMITED. IN ADDITION TO THE POSSIBILITY OF DUSTY OUTFLOWS WITH ANY CONVECTION...BREEZY SOUTHERLY WINDS WILL LIKELY RESULT IN A FAIR AMOUNT OF BLOWING DUST AGAIN THIS AFTERNOON INTO THE EVENING...SIMILAR TO YESTERDAY. THE REMAINDER OF THE FORECAST REMAINS IN GOOD SHAPE. UPDATE PRODUCTS HAVE BEEN SENT. && .PREV DISCUSSION... /ISSUED 638 AM CDT FRI JUN 21 2013/ AVIATION... BREEZY SOUTH WINDS WILL GUST TO NEAR 30 KNOTS TODAY AS A SURFACE TROUGH REMAINS IN CLOSE PROXIMITY TO BOTH TERMINALS. THEREFORE...WILL LEAVE PREVAILING MVFR CONDITIONS IN FOR BOTH SITES FROM MID-LATE MORNING THROUGH MID EVENING GIVEN THE LIKELIHOOD OF BLOWING DUST AGAIN TODAY. KLBB WILL SEE A BETTER CHANCE FOR SHOWERS OR STORMS IN THE VICINITY THAN KCDS...BUT CONFIDENCE IN COVERAGE IS NOT HIGH ENOUGH AT THIS TIME TO WARRANT MENTION. PREV DISCUSSION... /ISSUED 409 AM CDT FRI JUN 21 2013/ SHORT TERM... ISOLATED SHOWERS AND EMBEDDED THUNDER WILL CONTINUE TO WANE INTO THE EARLY MORNING HOURS. TIGHTENING SURFACE TROUGH NEAR THE NEW MEXICO STATE LINE ALONG WITH POSITIONING BEHIND A WAKE LOW NEAR THE INTERSTATE 40 CORRIDOR EAST OF AMARILLO HAVE KEPT WIND GUSTS IN THE 40 TO 50 MPH RANGE ON AN ABERNATHY TO FLOYDADA LINE. SHOULD SEE THESE STRONG GUSTS EXIT TO THE NORTH AND EAST AS THE WAKE LOW MOVES OFF IN THIS DIRECTION AND PRESSURE GRADIENT SOMEWHAT WEAKENS AWAY FROM THE TROUGH AXIS. SOUTHWEST FLOW REGIME WILL MAINTAIN ITSELF ALOFT TODAY AS BROAD TROUGHING BLANKETS MUCH OF THE WESTERN CONUS WITH UPPER RIDGING SOUTHEAST OF WEST TEXAS. FALLING PRESSURES IN CORRESPONDENCE WITH THE ABOVE REFERENCED DEEPENING SURFACE TROUGH EXTENDING FROM THE FRONT RANGE INTO EASTERN NEW MEXICO WILL LEAD TO THE BEST THUNDERSTORM CHANCES ACROSS THE FAR SOUTHWEST PANHANDLE AND WESTERN SOUTH PLAINS. RIBBON OF THETA-E VALUES WILL BE HIGHEST HERE WITH GREATER INSTABILITY AS SUFFICIENT MOISTURE REMAINS IN PLACE WITH DEWPOINTS IN THE UPPER 50S TO LOWER 60S. MORE PRONOUNCED ELEVATED MIXED LAYER TO THE EAST INTO THE ROLLING PLAINS AND EXTREME SOUTHEAST PANHANDLE WILL PRECLUDE CONVECTIVE INITIATION...BUT A 30 TO 40 KNOT LOW LEVEL JET AND INCREASING DEEP LAYER SHEAR TO NEAR 30 KNOTS MAY BE ENOUGH FOR PREEXISTING ACTIVITY TO SKIRT EAST OFF THE CAPROCK. STEEP LAPSE RATES ON EITHER SIDE OF THE ELEVATED MIXED LAYER AND RELATIVELY DRY NEAR SURFACE AIR DUE TO TEMPERATURES IN THE 90S WILL PROMOTE LARGE HAIL AND WIND GUSTS OF 50 TO 60 MPH IN STRONGER STORMS WEST OF THE ESCARPMENT DURING THE AFTERNOON AND EARLY EVENING. STORMS SHOULD WIND DOWN POST DIURNAL HEATING AND LEAVE A FEW STRAGGLING SHOWERS MOVING TO THE NORTH AND EAST. WINDS WILL REMAIN IN THE 10 TO 15 MPH RANGE OVERNIGHT AND COMBINE WITH RESIDUAL MOISTURE TO KEEP LOW TEMPERATURES A FEW DEGREES ABOVE CLIMATOLOGY...RANGING FROM THE MID TO UPPER 60S ON THE CAPROCK AND UPPER 60S TO LOW 70S IN THE ROLLING PLAINS AND FAR SOUTHEAST PANHANDLE. LONG TERM... BY SATURDAY MORNING...ELONGATED UPPER LOW WILL BE POSITIONED FROM IDAHO TO NORTHERN AB/SK WITH BROAD SOUTHWESTERLY FLOW ACROSS THE CENTRAL STATES. HIGH WILL CONTINUE TO STRENGTHEN ACROSS THE SOUTHEASTERN USA THOUGH THERE WILL BE A WEAKNESS OUT NEAR THE SMOKY MTNS. THE HIGH WILL BUILD AND SHIFT EAST TO WEST BY THE MIDDLE OF NEXT WEEK BEFORE STRENGTHENING FURTHER OVER THE FOUR CORNERS BY LATE IN THE WEEK WITH THE PATTERN LARGELY REMAINING STAGNANT OUT THROUGH 240 HOURS. INDICATIONS SUGGEST THAT THE WET PATTERN ACROSS OUR WESTERN ZONES WILL CONTINUE THROUGH AT LEAST SUNDAY WITH LESS OPPORTUNITY MONDAY EVENING AND THEREAFTER AS PATTERN CHANGES OVERHEAD. HAVE BUMPED POPS SAT/SUN AND TRIMMED MONDAY LEAVING THINGS DRY THEREAFTER. TEMPERATURES WILL BE ON THE INCREASE NEXT WEEK WITH VALUES APPROACHING THE CENTURY MARK BY MID WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 91 64 94 63 95 / 30 30 20 20 20 TULIA 91 66 93 66 94 / 20 30 20 20 20 PLAINVIEW 91 68 93 67 93 / 20 30 20 20 20 LEVELLAND 92 68 94 68 94 / 20 30 20 20 20 LUBBOCK 92 69 94 69 94 / 20 20 10 20 20 DENVER CITY 94 67 94 69 95 / 20 30 20 20 20 BROWNFIELD 93 68 94 69 94 / 20 20 20 20 20 CHILDRESS 95 70 97 70 96 / 20 20 10 10 10 SPUR 94 70 97 71 97 / 20 20 10 10 10 ASPERMONT 96 71 99 72 98 / 20 20 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
324 PM CDT FRI JUN 21 2013 .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * VARIABLE WIND DIRECTION BETWEEN SW AND SE NEXT FEW HOURS BECOMING MORE SOUTHEAST. MDB //DISCUSSION...UPDATED 20Z... CONVECTION NOW TO THE SOUTHEAST OF THE TERMINALS WITH SOME LINGERING LIGHT RAIN AND EMBEDDED THUNDER MOVING OUT OF THE AREA. WINDS HAVE BEEN SOMEWHAT ERRATIC BUT THE TREND LOOKS TO BE MORE SOUTHEASTERLY BY LATE AFTERNOON. GUSTS LOOK TO COME UP AND MAY NEED TO BUMP THEM UP FOR A BRIEF TIME TOWARD 21-22Z. BEYOND THAT PRECIP THREAT LOOKS MINIMAL THROUGH THE EVENING BUT WILL NEED TO WATCH CONVECTION CURRENTLY OVER EASTERN SOUTH DAKOTA WHICH MAY TRACK NEAR THE AREA LATE TONIGHT OR SATURDAY MORNING. MDB FROM 18Z... LINE OF STORMS CONTINUES TO MOVE EASTWARD WITH OUTFLOW/WIND SHIFT OUT AHEAD OF IT. OUTFLOW WILL REACH MDW SHORTLY AND GYY BY 1830-19Z OR SO. ARRIVAL OF STORMS AT GYY MAY NEED TO BE DELAYED SLIGHTLY AS THE EASTWARD PROGRESS HAS SLOWED SLIGHTLY BUT IT DOES LOOK AS THOUGH THEY WILL REACH THE FIELD. OTHERWISE RFD LOOKS TO GET BACK INTO LIGHTER RAIN WITH SOME EMBEDDED THUNDER WHICH DOES LOOK TO AFFECT THE CHICAGO AREA TERMINALS THROUGH MID AFTERNOON BEHIND THE MAIN LINE. WINDS WILL BE A CHALLENGE WITH A SHIFT TO NORTHWEST WITH THE OUTFLOW. BASED ON LATEST TRENDS...EXPECT THE NORTHERLY DIRECTION TO CONTINUE IMMEDIATELY BEHIND THE LINE WITH REDUCED SPEEDS BEFORE DIRECTION BECOMES VARIABLE BETWEEN NORTH AND EAST. WINDS WILL EVENTUALLY BECOME SOUTHERLY BUT HAVE LOW CONFIDENCE IN TIMING. ONCE THE PRECIP ENDS THIS AFTERNOON ADDITIONAL DEVELOPMENT LOOKS TO BE FOCUSED SOUTH OF THE TERMINALS. LOW CHANCES FOR SHRA/TSRA CONTINUE OVERNIGHT BUT AT THIS POINT CONFIDENCE IN OCCURRENCE AND COVERAGE IS LOW SO WILL LEAVE MENTION OUT FOR NOW. UPPER RIDGING WILL BE BUILDING IN SATURDAY SO SHRA/TSRA THREAT WILL DIMINISH THROUGH THE DAY. SOUTHWESTERLY WINDS ARE EXPECTED SATURDAY WITH GUSTS TO AROUND 20 KT EXPECTED BY MIDDAY. MDB //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN WIND TRENDS THROUGH THE EVENING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. SUNDAY...MAINLY VFR. CHC THUNDERSTORMS LATE. MONDAY THROUGH THURSDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE VFR. BEACHLER && .MARINE... 323 PM CDT S TO SW MODERATE TO OCCASIONALLY FRESH BREEZES WILL PREVAIL ON LAKE MI FOR THE NEXT SEVERAL DAYS AS A BROAD AREA OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE WESTERN ATLANTIC...EXTENDING BACK TO THE WEST ACROSS THE SOUTHEASTERN U.S. WHILE AN AREA OF LOW PRESSURE DRIFTS VERY SLOWLY EASTWARD ACROSS THE PLAINS. THIS PREVAILING S TO SW WIND WILL CONTINUE TO SPREAD VERY WARM AND MOIST AIR ACROSS THE REGION TONIGHT...AND MAINTAIN IT THROUGH THE WEEKEND AND INTO NEXT WEEK. AS THIS WARM MOIST AIR MOVES OUT OVER THE COOL OPEN WATERS OF LAKE MI FOG WILL FORM AND MAY BECOME DENSE AT TIMES. DISTURBANCES MOVING E FROM THE NORTHERN PLAINS AND ACROSS THE UPPER GREAT LAKES DURING THE NEXT SEVERAL DAYS WILL MAINTAIN PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
305 PM CDT FRI JUN 21 2013 .DISCUSSION... ISSUED 300 PM CDT FRI JUN 21 2013 INITIAL CONCERNS WILL FOCUS ON THE SEVERE POTENTIAL WITH THE LINE OF STORMS MOVING ACROSS OUR NORTHERN COUNTIES. THEN ATTENTION TURNS TO THE HEAT AND HUMIDITY WITH PERIODIC STORM CHANCES IN THIS SUMMER PATTERN. THE EXTENDED FORECAST STILL CALLS FOR OUR NEXT COLD FRONT TO ARRIVE AROUND THURSDAY. SHORT TERM...TONIGHT THROUGH MONDAY. A 30-40 MPH SOUTHWARD MOVING GUST FRONT IS GENERALLY OUTRUNNING THE LINE OF STORMS BY 5 TO 10 MILES IN MOST AREAS...EXCEPT FOR IN THE MID-PORTION OF THE LINE FROM DELAVAN TO BLOOMINGTON. STORM INITIATION REMAINS CLOSER TO THE GUST FRONT IN THAT AREA. THOSE STORMS ARE THE STRONGEST AT 230 PM...BUT STILL APPEAR TO BE SUB- SEVERE. HAIL AND WIND REPORTS HAVE BEEN SPARSE, BUT A FEW TREE LIMBS MAY HAVE BEEN KNOCKED DOWN NEAR DUNLAP AND THE LARGEST HAIL REPORT WAS DIME SIZED 1N OF MOSSVILLE EARLIER. STORM INTENSITY HAS GENERALLY WEAKENED SINCE THOSE REPORTS...SO WE CONTINUE TO MONITOR FOR ANY INTENSIFICATION. SPC MESO-ANALYSIS PAGE SHOWS MORE STABLE AIR AHEAD OF THE STORMS...WITH WEAKER 0-6KM BULK SHEAR. THERE IS STILL 1500 J/KG MUCAPE AVAILABLE...SO THE STORMS MAY LINGER AT LEAST UNTIL THE INDIANA BORDER EARLY THIS EVENING. INTO EARLY EVENING...A COUPLE 4KM MODELS ARE SHOWING ADDITIONAL STORM DEVELOPMENT FARTHER WEST IN EASTERN IOWA/NE MO WHERE INSTABILITY AND SHEAR PARAMS ARE MORE FAVORABLE FOR STORMS. HOWEVER...THE 18Z HRRR RUN DOES NOT HAVE ANY INDICATION OF THOSE STORMS. TAKING EVERYTHING INTO CONSIDERATION...WE TRIED TO MAKE THE POPS/WEATHER GRIDS CONFORM CLOSELY TO THE NEXT 3-5 HOURS OF CONVECTION...THEN WENT MORE GENERAL BASED ON SATELLITE, RADAR AND OBSERVATION TRENDS. WE LINGERED SOME HIGHER POPS THROUGH 03Z THIS EVENING IN THE EAST TO TREND THE CURRENT STORMS EASTWARD...WITH SLIGHT CHANCE IN OUR WESTERN COUNTIES TO COVER THE NEXT LINE THAT MAY ARRIVE. THE REST OF THE NIGHT SHOULD BE MUGGY AND MILD...AS CLOUDS CLEAR OUT AND LINGERING NORTH WINDS BEHIND THIS LINE OF STORMS RETURNS TO SOUTHERLY. SATURDAY WILL BRING ANOTHER ROUND OF AFTERNOON SHOWERS AND STORMS AS HIGHS CLIMB INTO THE LOWER 90S AND HEAT INDICES REACH AROUND 100. SEVERE CHANCES SHOULD REMAIN LOW IN OUR COUNTIES...WITH THE SLIGHT RISK FOR DAY 2 NW OF ILLINOIS. THE TRIGGERS FOR STORMS MAY BE TIED TO THE RESIDUAL OUTFLOW BOUNDARIES FROM TODAY`S CONVECTION...AND THE PASSAGE OF A WEAK 500 MB SHORTWAVE. PRECIPITABLE WATER VALUES AROUND 1.75" WILL ALLOW SOME OF THE STRONGER STORMS TO BE VERY HEAVY RAIN PRODUCERS...WITH RAINFALL RATES OF 1-2" PER HOUR. LOCALIZED FLASH FLOODING WILL BE POSSIBLE...DESPITE THE RELATIVELY DRY CONDITIONS OVER THE PAST COUPLE OF WEEKS IN MOST AREAS. STORMS SHOULD COME TO AN END BY SATURDAY EVENING...WITH CLEARING SKIES OVERNIGHT. SUNDAY WILL SEE LESS FAVORABLE INSTABILITY PARAMS...AS MID LEVEL WARMING PROVIDES A BETTER CAP ON STORM DEVELOPMENT. WE KEPT A DRY FORECAST FOR SUNDAY...BUT KEPT THE HEAT AND HUMIDITY HIGH. HEAT INDEX READING SHOULD REMAIN BELOW SATURDAYS READINGS...BUT STILL IN THE MID TO UPPER 90S. MONDAY WILL SEE THE RETURN OF STORM CHANCES AS THE NEXT 500MB SHORTWAVE CREATES SOME FALLING HEIGHTS AND DESTABILIZES THE LOWER TROPOSPHERE. STORM DEVELOPMENT SHOULD OCCUR IN THE AFTERNOON...AS SURFACE HEATING HELPS TO ERODE THE CAP. WE WENT WITH CHANCE POPS IN THE NW HALF OF OUR FORECAST AREA...WITH SLIGHTS DOWN TO I-70. LONG TERM...TUESDAY THROUGH FRIDAY. ANOTHER LULL IN THE STORMS IS EXPECTED MONDAY NIGHT THRU TUESDAY NIGHT...AS THE UPPER TROUGH IN THE N PLAINS BEGINS TO BECOME PROGRESSIVE. AS THE UPPER TROUGH REACHES THE GREAT LAKES...A SURFACE COLD FRONT IS FORECAST TO MOVE ACROSS ILLINOIS ON THURSDAY OR THURSDAY NIGHT. SHOWERS AND STORMS WILL LIKELY DEVELOP ALONG THAT FEATURE...DESPITE THE WEAKER APPEARANCE OF THE FRONT IN THE EXTENDED MODELS. THE NORTHWEST FLOW BEHIND THAT COLD FRONT WILL HELP DROP HIGHS FROM THE LOW 90S ON TUESDAY AND WED...BACK INTO THE UPPER 80S THURSDAY AND LOWER 80S ON FRIDAY. DEWPOINTS WILL DROP INTO THE LOWER 60S ON FRIDAY AS WELL...PROVIDING SOME RELIEF FROM THE HEAT AND HUMIDITY. SHIMON && .AVIATION... ISSUED 1240 PM CDT FRI JUN 21 2013 CONVECTION TO OUR NORTH CONTINUES TO SLOWLY SINK SOUTHEAST EARLY THIS AFTERNOON. LEADING EDGE OF COLD POOL/OUTFLOW BOUNDARY CLEARLY EVIDENT ON KDVN REFLECTIVITY AND IS SHIFTING SOUTH AROUND 20 KTS AND IS NOW PUSHING INTO NORTHERN KNOX AND STARK COUNTIES. IF THIS MAINTAINS TRENDS WOULD PASS THROUGH KPIA JUST BEFORE 19Z AND KBMI AT 20Z. BEHIND THIS BOUNDARY WINDS SHIFT NORTH GUSTING AROUND 20 KTS. LIFT OFF THE BOUNDARY IS PRODUCING SCATTERED TSRA BEHIND IT SO HAVE INCLUDED VCTS AFTER PASSAGE FOR KPIA/KBMI WITH A TEMP PERIOD AT KPIA WHERE HAVE HIGHER CONFIDENCE. BOUNDARY SHOULD EVENTUALLY SLOW AND STALL AS MAIN CONVECTIVE BATCH TO THE NORTH SHIFTS EAST...AND 10-20 KT SOUTHWEST SYNOPTIC FLOW PROVIDES RESISTANCE. SO HAVE KEPT THIS ACTIVITY OUT OF THE TERMINALS FARTHER SOUTH/EAST. GUSTY S/SW WINDS WILL DROP BELOW 10 KTS AFTER SUNSET...THEN PICK UP AGAIN AFTER 14Z/SAT. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 PM CDT FRI JUN 21 2013 .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * VARIABLE WIND DIRECTION BETWEEN SW AND SE NEXT FEW HOURS BECOMING MORE SOUTHEAST. MDB //DISCUSSION...UPDATED 20Z... CONVECTION NOW TO THE SOUTHEAST OF THE TERMINALS WITH SOME LINGERING LIGHT RAIN AND EMBEDDED THUNDER MOVING OUT OF THE AREA. WINDS HAVE BEEN SOMEWHAT ERRATIC BUT THE TREND LOOKS TO BE MORE SOUTHEASTERLY BY LATE AFTERNOON. GUSTS LOOK TO COME UP AND MAY NEED TO BUMP THEM UP FOR A BRIEF TIME TOWARD 21-22Z. BEYOND THAT PRECIP THREAT LOOKS MINIMAL THROUGH THE EVENING BUT WILL NEED TO WATCH CONVECTION CURRENTLY OVER EASTERN SOUTH DAKOTA WHICH MAY TRACK NEAR THE AREA LATE TONIGHT OR SATURDAY MORNING. MDB FROM 18Z... LINE OF STORMS CONTINUES TO MOVE EASTWARD WITH OUTFLOW/WIND SHIFT OUT AHEAD OF IT. OUTFLOW WILL REACH MDW SHORTLY AND GYY BY 1830-19Z OR SO. ARRIVAL OF STORMS AT GYY MAY NEED TO BE DELAYED SLIGHTLY AS THE EASTWARD PROGRESS HAS SLOWED SLIGHTLY BUT IT DOES LOOK AS THOUGH THEY WILL REACH THE FIELD. OTHERWISE RFD LOOKS TO GET BACK INTO LIGHTER RAIN WITH SOME EMBEDDED THUNDER WHICH DOES LOOK TO AFFECT THE CHICAGO AREA TERMINALS THROUGH MID AFTERNOON BEHIND THE MAIN LINE. WINDS WILL BE A CHALLENGE WITH A SHIFT TO NORTHWEST WITH THE OUTFLOW. BASED ON LATEST TRENDS...EXPECT THE NORTHERLY DIRECTION TO CONTINUE IMMEDIATELY BEHIND THE LINE WITH REDUCED SPEEDS BEFORE DIRECTION BECOMES VARIABLE BETWEEN NORTH AND EAST. WINDS WILL EVENTUALLY BECOME SOUTHERLY BUT HAVE LOW CONFIDENCE IN TIMING. ONCE THE PRECIP ENDS THIS AFTERNOON ADDITIONAL DEVELOPMENT LOOKS TO BE FOCUSED SOUTH OF THE TERMINALS. LOW CHANCES FOR SHRA/TSRA CONTINUE OVERNIGHT BUT AT THIS POINT CONFIDENCE IN OCCURRENCE AND COVERAGE IS LOW SO WILL LEAVE MENTION OUT FOR NOW. UPPER RIDGING WILL BE BUILDING IN SATURDAY SO SHRA/TSRA THREAT WILL DIMINISH THROUGH THE DAY. SOUTHWESTERLY WINDS ARE EXPECTED SATURDAY WITH GUSTS TO AROUND 20 KT EXPECTED BY MIDDAY. MDB //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN WIND TRENDS THROUGH THE EVENING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. SUNDAY...MAINLY VFR. CHC THUNDERSTORMS LATE. MONDAY THROUGH THURSDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE VFR. BEACHLER && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
101 PM CDT FRI JUN 21 2013 .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * TSRA CROSSING THE TERMINALS WITH IFR VSBY AND VERY HEAVY RAINFALL. * NORTH TO NORTHWEST WINDS GUSTY WITH STORMS THEN DIMINISHING AND BECOMING VARIABLE FROM NORTH TO EAST...THEN EVENTUALLY BACK TO SOUTHERLY MID AFTERNOON. MDB //DISCUSSION...UPDATED 18Z... LINE OF STORMS CONTINUES TO MOVE EASTWARD WITH OUTFLOW/WIND SHIFT OUT AHEAD OF IT. OUTFLOW WILL REACH MDW SHORTLY AND GYY BY 1830-19Z OR SO. ARRIVAL OF STORMS AT GYY MAY NEED TO BE DELAYED SLIGHTLY AS THE EASTWARD PROGRESS HAS SLOWED SLIGHTLY BUT IT DOES LOOK AS THOUGH THEY WILL REACH THE FIELD. OTHERWISE RFD LOOKS TO GET BACK INTO LIGHTER RAIN WITH SOME EMBEDDED THUNDER WHICH DOES LOOK TO AFFECT THE CHICAGO AREA TERMINALS THROUGH MID AFTERNOON BEHIND THE MAIN LINE. WINDS WILL BE A CHALLENGE WITH A SHIFT TO NORTHWEST WITH THE OUTFLOW. BASED ON LATEST TRENDS...EXPECT THE NORTHERLY DIRECTION TO CONTINUE IMMEDIATELY BEHIND THE LINE WITH REDUCED SPEEDS BEFORE DIRECTION BECOMES VARIABLE BETWEEN NORTH AND EAST. WINDS WILL EVENTUALLY BECOME SOUTHERLY BUT HAVE LOW CONFIDENCE IN TIMING. ONCE THE PRECIP ENDS THIS AFTERNOON ADDITIONAL DEVELOPMENT LOOKS TO BE FOCUSED SOUTH OF THE TERMINALS. LOW CHANCES FOR SHRA/TSRA CONTINUE OVERNIGHT BUT AT THIS POINT CONFIDENCE IN OCCURRENCE AND COVERAGE IS LOW SO WILL LEAVE MENTION OUT FOR NOW. UPPER RIDGING WILL BE BUILDING IN SATURDAY SO SHRA/TSRA THREAT WILL DIMINISH THROUGH THE DAY. SOUTHWESTERLY WINDS ARE EXPECTED SATURDAY WITH GUSTS TO AROUND 20 KT EXPECTED BY MIDDAY. MDB //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN TSRA TRENDS BEFORE 19Z...MEDIUM CONFIDENCE IN LINGERING LIGHT RAIN AND EMBEDDED TS THROUGH MID AFTERNOON. HIGH CONFIDENCE IN PERIODIC IFR VSBY WITH MAIN LINE. * HIGH CONFIDENCE IN NORTH TO NORTHWEST WINDS WITH STORMS...MEDIUM CONFIDENCE IN DIMINISHING TREND AND VARIABILITY BETWEEN NORTH AND EAST...THEN EVENTUALLY TURNING SOUTHERLY...LOW CONFIDENCE IN TIMING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. SUNDAY...MAINLY VFR. CHC THUNDERSTORMS LATE. MONDAY THROUGH THURSDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE VFR. BEACHLER && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1240 PM CDT FRI JUN 21 2013 .DISCUSSION... ISSUED 1039 AM CDT FRI JUN 21 2013 SEVERE CONVECTIVE COMPLEX TO OUR NORTH MAIN ISSUE. THIS HAS BEEN MAINTAINED BY A 40-45 KT SW 925 MB LOW LEVEL JET EVIDENT ON AREA VWP/S AND A SIGNIFICANT SHORTWAVE SHIFTING THROUGH NRN WI. LATEST RAP FORECASTS INDICATE THE LLJ WEAKENING TO AROUND 20 KTS AND BACKING AROUND TO THE SOUTH BY MIDDAY...AND CONVECTIVE MODEL WHICH HAS BEEN HANDLING THIS COMPLEX BEST /3-KM HRRR/ SHOWS LINE WEAKENING AS IT SHIFTS SE INTO AFTERNOON. LATEST RADAR TRENDS SHOW COLD POOL HAS SURGED OUT WELL AHEAD OF THE MIDDLE PORTION OF THE LINE WITH A WEAKENING TREND ALREADY NOTED DOWN THE MISSISSIPPI VALLEY...WHILE SVR/NEAR SVR WIND GUSTS CONTINUE IN PARTS OF NE IA AN NORTH CENTRAL IL. ALSO BEST SHEAR REMAINS TO OUR NORTH TIED TO THE SHORTWAVE AND WITH ALL THESE FACTORS IN MIND FEEL ACTIVITY WILL WEAKEN AS IT APPROACHES THE NORTHERN CWA IN THE NEXT FEW HOURS. HAVE UPPED POPS TO MID-HIGH CHANCE NORTH OF A GALESBURG TO EL PASO LINE FOR EARLY AFTERNOON WITH CHANCES QUICKLY DIMINISHING SOUTH OF THERE AS ACTIVITY TENDS TO FADE BY MID AFTERNOON. WILL KEEP A CLOSE EYE ON THESE TRENDS THOUGH AS 1500-2000 J/KG MLCAPES WILL BE PRESENT OVER CENTRAL IL. ANOTHER CONCERN WILL BE POTENTIAL MID/LATE AFTERNOON DEVELOPMENT ALONG RESULTING OUTFLOW BOUNDARY AND SOME HI-RES GUIDANCE INCLUDING HRRR AND 4KM NSSL WRF POINT TO A FAVORED AREA ALONG AN INSTABILITY AXIS IN SE IA/NE MO/WEST CENTRAL IL AFTER 21Z. THUS HAVE SLIGHT CHANCE POPS FOR THE FAR WEST LATE AFTERNOON. OTHERWISE...BULK OF CWA SHOULD REMAIN DRY TODAY AND HOT AND HUMID WEATHER WILL BE THE MAIN STORY. 10 AM TEMPS ALREADY IN THE MID 80S AND WHILE INCOMING CIRRUS SHIELD MAY INHIBIT TEMP RISE SOMEWHAT...STILL THINK WIDESPREAD HIGHS IN THE LOW 90S LIKELY. THESE TEMPS COMBINED WITH DEWPOINTS IN THE UPPER 60S WILL PRODUCE AFTERNOON HEAT INDICES IN THE MID TO UPPER 90S. && .AVIATION... ISSUED 1240 PM CDT FRI JUN 21 2013 CONVECTION TO OUR NORTH CONTINUES TO SLOWLY SINK SOUTHEAST EARLY THIS AFTERNOON. LEADING EDGE OF COLD POOL/OUTFLOW BOUNDARY CLEARLY EVIDENT ON KDVN REFLECTIVITY AND IS SHIFTING SOUTH AROUND 20 KTS AND IS NOW PUSHING INTO NORTHERN KNOX AND STARK COUNTIES. IF THIS MAINTAINS TRENDS WOULD PASS THROUGH KPIA JUST BEFORE 19Z AND KBMI AT 20Z. BEHIND THIS BOUNDARY WINDS SHIFT NORTH GUSTING AROUND 20 KTS. LIFT OFF THE BOUNDARY IS PRODUCING SCATTERED TSRA BEHIND IT SO HAVE INCLUDED VCTS AFTER PASSAGE FOR KPIA/KBMI WITH A TEMP PERIOD AT KPIA WHERE HAVE HIGHER CONFIDENCE. BOUNDARY SHOULD EVENTUALLY SLOW AND STALL AS MAIN CONVECTIVE BATCH TO THE NORTH SHIFTS EAST...AND 10-20 KT SOUTHWEST SYNOPTIC FLOW PROVIDES RESISTANCE. SO HAVE KEPT THIS ACTIVITY OUT OF THE TERMINALS FARTHER SOUTH/EAST. GUSTY S/SW WINDS WILL DROP BELOW 10 KTS AFTER SUNSET...THEN PICK UP AGAIN AFTER 14Z/SAT. 25 && .PREV DISCUSSION... ISSUED 256 AM CDT FRI JUN 21 2013 QUIET SUMMER-LIKE WEATHER WILL PREVAIL FOR SEVERAL DAYS...WITH THE NEXT SIGNIFICANT CHANCE FOR RAIN HOLDING OFF UNTIL THE MIDDLE OF NEXT WEEK. SHORT TERM...TODAY THROUGH SUNDAY MCS CURRENTLY ACROSS MINNESOTA WILL TRACK E/SE INTO WISCONSIN THIS MORNING...REMAINING WELL NORTH OF CENTRAL ILLINOIS. FURTHER SOUTH BENEATH THE BUILDING UPPER-LEVEL RIDGE...A WEAK FRONTAL BOUNDARY IS SETTING OFF WIDELY SCATTERED SHOWERS/THUNDER ACROSS EASTERN IOWA AND WESTERN ILLINOIS. THINK THIS SUBTLE BOUNDARY WILL CONTINUE TO BE THE MAIN FOCUSING MECHANISM FOR ADDITIONAL CONVECTION THROUGHOUT THE DAY. DUE TO LACK OF UPPER SUPPORT AND WARMING MID-LEVELS BENEATH THE RIDGE...WIDESPREAD CONVECTION WILL REMAIN UNLIKELY. WILL CARRY 20 POPS ALONG AND WEST OF I-55 IN CLOSE PROXIMITY TO THE FRONT...WITH DRY WEATHER FURTHER EAST AND SOUTH. WILL BE A VERY WARM/HUMID DAY AS WELL...WITH AFTERNOON HIGHS REACHING THE LOWER 90S. MODELS CONTINUE TO SUGGEST ISOLATED DIURNAL CONVECTION WILL DEVELOP SATURDAY AFTERNOON...AS MID-LEVEL CAP REMAINS MARGINAL. WILL CONTINUE TO FEATURE SLIGHT CHANCE POPS ACCORDINGLY. AS CAP STRENGTHENS...SUNDAY LOOKS TO BE A SUNNY AND DRY DAY. MAIN STORY TODAY THROUGH SUNDAY WILL BE THE HEAT. HIGH TEMPS EACH DAY WILL RISE INTO THE LOWER 90S...WHILE OVERNIGHT LOWS ONLY DROP INTO THE LOWER 70S. THESE TEMPERATURES COMBINED WITH DEWPOINTS IN THE UPPER 60S AND LOWER 70S...WILL PRODUCE AFTERNOON HEAT INDEX READINGS OF 95 TO 100 DEGREES. LONG TERM...MONDAY THROUGH THURSDAY UPPER RIDGE WILL GRADUALLY RETROGRADE WESTWARD NEXT WEEK...WITH BOTH THE GFS AND ECMWF SHOWING RIDGE BUILDING OVER THE ROCKIES BY WEDNESDAY/THURSDAY. AS A RESULT...INCREASING NORTHWESTERLY FLOW DOWNSTREAM FROM THE RIDGE WILL PUSH A COLD FRONT INTO ILLINOIS BY THE MIDDLE OF THE WEEK. MODELS STILL EXHIBIT A BIT OF A SPREAD IN SOLUTIONS...BUT GENERAL CONSENSUS BRINGS FRONT INTO THE AREA BY WEDNESDAY NIGHT/THURSDAY. HAVE INTRODUCED CHANCE POPS ACROSS THE NORTHERN CWA ON WEDNESDAY...THEN EVERYWHERE WEDNESDAY NIGHT INTO THURSDAY. ONCE FRONT PASSES...COOLER AND LESS HUMID WEATHER WILL ARRIVE BY THE END OF NEXT WEEK. BARNES && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1152 AM CDT FRI JUN 21 2013 .MESOSCALE DISCUSSION... 1150 AM CDT UPDATE CONVECTION HAS ORGANIZED INTO A LINE FROM NE OF MILWAUKEE BACK TO NEAR PRINCETON AND CONTINUES TO MOVE EASTWARD. LATEST MESOANALYSIS SHOWS THE CIN HAS ERODED AHEAD OF THE LINE ACROSS THE AREA WITH SURFACE BASED AND MIXED LAYER INSTABILITY INCREASING TO AROUND 1500 J/KG. OUTFLOW HAS PUSHED AHEAD OF THE NORTHERN PART OF THE LINE BUT CONTINUES TO INTERACT WITH THE SOUTHWEST PORTION ACROSS SOUTHERN DEKALB...LEE AND FAR NW LA SALLE COUNTIES. THE AXIS OF GREATEST INSTABILITY ALONG WITH STEEPEST LAPSE RATES IS ACROSS THE SOUTHWEST CWA WHICH SUPPORTS LATEST RADAR TRENDS OF RENEWED AND FAIRLY STRONG DEVELOPMENT OF STORMS BACK TOWARDS PRINCETON. OVERALL THE GREATEST SEVERE THREAT APPEARS TO BE FROM ALONG AND SOUTH OF INTERSTATE 88 BACK TO INTERSTATE 80 WHERE BEST PARAMETERS LINE UP. SOUTHERN EXTENT MAY EXPAND FURTHER SOUTHWEST AND EVENTUALLY AFFECT PONTIAC AND POINTS SOUTH EARLY THIS AFTERNOON AS THE OUTFLOW SLIPS SOUTHWARD. TO THE NORTH...SEVERE THREAT LOOKS MORE LIMITED WITH THAT PORTION OF THE LINE LOOKING OUTFLOW DOMINANT AT THE MOMENT. LOCALIZED FLOODING IS A POSSIBILITY WITH A VERY MOIST ATMOSPHERE AND SOME REGENERATION OF CELLS OVER AREAS PREVIOUSLY AFFECTED BY HEAVY DOWNPOURS. THIS WILL BE FOCUSED CLOSER TO THE OUTFLOW BOUNDARY ACROSS SOUTHERN LEE AND MAY EXPAND INTO LA SALLE COUNTY IN THE NEXT HOUR OR SO. OTHERWISE URBAN AREAS WILL BE SUSCEPTIBLE TO PONDING AND LOCALIZED FLOODING. OVERALL HAVE SEEN RAINFALL RATES ON THE ORDER OF AROUND AN INCH PER HOUR. MDB && .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * LINE OF TS ARRIVING IN THE 17-18Z TIME FRAME. * WIND SHIFT TO NW WITH GUSTS EXPECTED AND VSBY BRIEFLY DOWN TO AROUND 1SM. * LIGHT/VARIABLE NW-NE WINDS EXPECTED BEHIND MAIN LINE OF STORMS...WINDS THEN EXPECTED TO RETURN TO SOUTHERLY BY MID AFTERNOON. * -RA/EMBEDDED TS LINGERS THROUGH EARLY AFTERNOON. MDB //DISCUSSION...UPDATED 16Z... LINE OF STORMS NOW ORIENTED FROM W OF KENW TO KDKB TO W OF KVYS AND MOVING EAST. SOUTHERN EXTENT HAS INCREASED SO HAVE SO HAVE HIGHER CONFIDENCE IN MDW BEING AFFECTED AND HAVE AMENDED TO SHOW THIS. OTHERWISE ORD/DPA WILL BE AFFECTED AS WELL. WILL LIKELY NEED TO HIT THE TS HARDER AT GYY WITH ARRIVAL TOWARD 1830/19Z OR SO. EXPECT WIND SHIFT TO THE N/NNW WITH THE STORMS WITH WINDS THEN DIMINISHING AND BECOMING VARIABLE FROM THE NORTH AND EAST...BEFORE EVENTUALLY BECOMING SOUTHERLY AGAIN. MDB FROM 12Z... LARGE COMPLEX OF THUNDERSTORMS OVER THE UPPER MIDWEST EARLY THIS MORNING WAS SLOWLY SLIDING SOUTHEAST. REGIONAL RADAR INDICATED A LINE OF THUNDERSTORMS STILL ASSOCIATED WITH THIS COMPLEX STRETCHING FROM FAR NORTHEAST IOWA INTO WEST CENTRAL WISCONSIN. GUIDANCE INDICATES THAT THIS LINE WILL BEGIN TO WEAKEN AS IT CONTINUES TO SLIDES SOUTHEAST. CURRENT THINKING IS THAT SOME REMNANTS OF THIS LINE OF THUNDERSTORMS MAY ARRIVE LATER THIS MORNING. THE TIMING WOULD BE INTO RFD ARND 16Z THEN FURTHER EAST AT ORD/MDW/DPA/GYY CLOSER TO 18Z ARRIVAL. WITH SOME HEATING AHEAD OF THIS LINE OVER NORTHERN IL/NORTHWEST IN AIRFIELDS...THIS MAY AID IN MAINTAINING THIS LINE OF CONVECTION. AT THIS TIME HAVE OPTED TO GO WITH A VCTS RATHER THAN A PREVAILING MENTION. BUT THAT MAY NEED TO BE CHANGED FOR THE 14Z AMD. SOUTHERLY WINDS WILL CONTINUE THRU MUCH OF THE DAY WITH OCCASIONAL GUSTS BEGINNING TO OCCUR LATER THIS MORNING TO AROUND 20 KT. CLOUD DECKS SHUD BE AROUND 5KFT AGL...AND MAY SLOWLY GROW IN COVERAGE THROUGHOUT THE AFT FROM A SCT TO BKN. GUIDANCE IS THEN REDEVELOPING A LINE OF SHOWERS/THUNDERSTORMS LATE THIS AFTN/EVE ALONG A REMNANT BOUNDARY FROM THIS MORNING CONVECTION. SOME OF THESE THUNDERSTORMS COULD BE STRONG TO SEVERE...WITH THE MAIN HAZARDS BEING WIND/HAIL. SOUTHERLY WINDS PERSIST OVERNIGHT AND DIMINISH TO ARND 10KT...WITH SOME TURNING TO THE SOUTHWEST EXPECTED OVERNIGHT TOWARDS DAYBREAK SAT. OVERALL EXPECT VFR CONDS THROUGHOUT...HOWEVER WITH ANY THUNDERSTORM ACTIVITY THIS COULD EASILY BE LIMITED TO MVFR. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN TS TIMING. * HIGH CONFIDENCE IN WIND SHIFT TO NW WITH GUSTS...MEDIUM CONFIDENCE IN GUSTS SPEEDS...HIGH CONFIDENCE IN IFR VSBY. * MEDIUM CONFIDENCE IN WIND TRENDS BEHIND MAIN LINE OF STORMS...LOW CONFIDENCE IN TIMING OF DIRECTION CHANGES. * LOW-MEDIUM CONFIDENCE IN COVERAGE/DURATION OF LINGERING -RA/EMBEDDED TS EARLY THIS AFTERNOON. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. SUNDAY...MAINLY VFR. CHC THUNDERSTORMS LATE. MONDAY THROUGH THURSDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE VFR. BEACHLER && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1133 AM CDT FRI JUN 21 2013 .MESOSCALE DISCUSSION... 1000 AM CDT COMPLEX OF STORMS CONTINUES TO EVOLVE ACROSS SOUTHERN WI/FAR NW IL/NE IA. LATEST RADAR TRENDS SHOW REFLECTIVITY WEAKENING TOWARD THE DBQ AREA WITH A MORE PERSISTENT LINE NOW SET UP FROM SOUTHERN CENTRAL WI BACK TO FREEPORT AND SAVANNA MOVING EASTWARD. THE ATMOSPHERE AHEAD OF THIS ACROSS THE LOCAL AREA IS STILL CAPPED AND THE COMPLEX IS BEGINNING TO OUTRUN BETTER DEEP LAYER SHEAR. SOME OUTFLOW IS PRESENT BASED ON SFC OBS SHIFTING WINDS TO THE NORTHWEST WITH SOME GUSTINESS BUT THE LINE MAY BE BECOMING ELEVATED. THAT SAID...WINDS SOUTH OF THE LINE HAVE TURNED MORE SOUTH-SOUTHWEST HELPING TO FEED SLIGHTLY HIGHER DEWPOINT AIR NORTHWARD. HOWEVER...IT DOES LOOK TO BE A FEW MORE HOURS BEFORE CAPPING CAN ERODE WHICH WOULD LIKELY BE TOO LATE TO INTERSECT WITH CURRENT STORMS. AT THIS POINT EXPECT THE BEST COVERAGE OF STORMS TO MOVE EAST OR EAST-SOUTHEAST ALONG A LINE FROM FREEPORT TO CHICAGO THOUGH THE SOUTHERN END OF THE LINE MAY BE MORE VARIABLE IN COVERAGE. HEAVY DOWNPOURS WILL OCCUR AND THE LATEST RADAR SCANS HAVE SHOWN A SLOWING TREND SO LOCALIZED FLOODING IS A THREAT WITH 1 INCH+ PER HOUR RAINFALL RATES LIKELY BASED ON UPSTREAM REPORTS. AN ISOLATED STRONG/SEVERE WIND THREAT EXISTS MAINLY IF CAPPING CAN ERODE. A BOUNDARY MAY LAY OUT ACROSS THE AREA THANKS TO THIS ACTIVITY LEADING TO AT LEAST A LOW CHANCE FOR NEW DEVELOPMENT LATER TODAY. MDB && .DISCUSSION... 329 AM CDT THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE THE EVOLUTION OF THE MCS OVER THE UPPER MS VALLEY TODAY. THIS COULD BE FOLLOWED BY ADDITIONAL STORM CLUSTERS THROUGH SATURDAY...AND AGAIN MONDAY THROUGH WEDNESDAY. ALSO THE BUILDING HEAT AND HUMIDITY THROUGH THE MIDDLE OF NEXT WEEK. IN THE SHORT TERM A NARROW BAND OF SHOWERS AND WEAK THUNDERSTORMS EXTENDS FROM WESTERN WI TO THE IL/IA BORDER. THIS ACTIVITY OCCURRING ALONG AN AXIS OF HIGHER LOW LEVEL MOISTURE AND THE EASTERN EDGE OF THE LOW LEVEL JET. EXPECT THIS ACTIVITY TO WEAKEN AND DIE EARLY THIS MORNING AS IT MOVES INTO DRIER AND MORE STABLE ATMOSPHERE. HAVE SOME LOW POPS FOR FAR WESTERN COUNTIES THROUGH MID MORNING. MEANWHILE VERY ACTIVE MCS OVER MN DIVING SOUTHEAST. THIS ACTIVITY SHOULD BE ON A DIURNALLY WEAKENING TREND LATER THIS MORNING. MEAN MID AND UPPER LEVEL WINDS ARE WESTERLY WITH FLAT RIDGE ACROSS THE UPPER MS VALLEY AND GREAT LAKES...WHICH MIGHT SUGGEST THIS WILL REMAIN MAINLY NORTH OVER WISCONSIN...BUT ACTIVITY IS DROPPING SOUTHEAST AS CONVECTION BACK BUILDS INTO LOW LEVEL JET. IF IT HOLDS TOGETHER ON ITS PRESENT COURSE...IT WILL BE APPROACHING NORTHWEST AND NORTH CENTRAL IL BY LATE MORNING. HRRR SEEMS TO BE THE MOST AGGRESSIVE OF THE SHORT TERM GUIDANCE IN BRINGING PRECIP INTO NORTHERN IL TODAY. DEEP LAYER SHEAR WILL BE LACKING THIS FAR SOUTH BUT WITH BUILDING HEAT AND SURFACE DEW POINTS CLIMBING INTO THE MID AND UPPER 60S...THERE MAY BE SUFFICIENT LOW LEVEL INSTABILITY FOR STORMS TO CONTINUE SOUTHEASTWARD INTO IL. HAVE MAINTAINED 30-40 PERCENT POPS MAINLY FOR NORTHERN COUPLE OF TIERS OF COUNTIES. SPC HAS MUCH OF NORTHERN IL IN SLIGHT RISK FOR WIND AND HAIL THREAT. THE ASSOCIATED CIRRUS SHIELD MAY ALSO IMPACT TEMPERATURES. THEREFORE HAVE LOWERED MAX TEMPS ACROSS THE FAR NORTH DOWN A COUPLE DEGREES TO THE MID 80S WHILE KEEPING MAX TEMPS IN UPPER 80S TO NEAR 90 FURTHER SOUTH. EXPECT SOUTH WINDS TO BE SUFFICIENTLY STRONG TO PREVENT A LAKE BREEZE. ALTHOUGH WITH SOUTH TO SLIGHTLY EAST OF SOUTH WINDS...A WEAK LAKE BREEZE MAY DRIFT ONSHORE ACROSS NORTHERN COOK AND LAKE COUNTY IN THIS AFTERNOON. ANOTHER MCS MAY DEVELOP AND MOVE THROUGH THE NORTHERN PART OF THE FORECAST AREA AGAIN SATURDAY AS A SERIES OF WEAK WAVES MOVES THROUGH THE RING OF FIRE ACROSS THE GREAT LAKES. BUT LOW CONFIDENCE THIS FAR OUT. THE GENERAL TREND OF THE MODELS IS TO SLOWLY BUILD THE RIDGE INTO THE WESTERN GREAT LAKES OVER THE WEEKEND. THEREFORE HAVE JUST LOW CHANCE POPS FOR SATURDAY AND A DRY FORECAST FOR SUNDAY. MONDAY THROUGH WEDNESDAY A SERIES OF WAVES SUPPRESSES THE RIDGE...WHICH EVENTUALLY RE-ESTABLISHES ITSELF OVER THE WESTERN US. BY THE END OF THE WEEK MODELS IN DECENT AGREEMENT IN DEVELOPING AN UPPER LOW OVER THE GREAT LAKES. MAX TEMPERATURES EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 TODAY THROUGH WEDNESDAY...WITH DEW POINTS IN THE UPPER 60S TO AROUND 70. THIS PRODUCES HEAT INDEX VALUES IN MID TO UPPER 90S. THIS IS BELOW LOCAL HEAT ADVISORY THRESHOLDS. HOWEVER SEEING AS THIS IS THE FIRST HEAT WAVE OF THE SUMMER AND IT MAY PERSIST FOR SEVERAL DAYS. A HEAT ADVISORY MAY NEED TO BE CONSIDERED BY EARLY TO MID WEEK. ANY THUNDERSTORMS AND ASSOCIATED CLOUD COVER/OUTFLOW BOUNDARIES MAY TEMPORARILY COOL THINGS DOWN AND IMPACT ANY FUTURE DECISIONS ON HEAT HEADLINES. PATTERN LOOKS TO BECOME MUCH COOLER NEXT WEEKEND. ALLSOPP && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * LINE OF TS ARRIVING IN THE 17-18Z TIME FRAME. * WIND SHIFT TO NW WITH GUSTS EXPECTED AND VSBY BRIEFLY DOWN TO AROUND 1SM. * LIGHT/VARIABLE NW-NE WINDS EXPECTED BEHIND MAIN LINE OF STORMS...WINDS THEN EXPECTED TO RETURN TO SOUTHERLY BY MID AFTERNOON. * -RA/EMBEDDED TS LINGERS THROUGH EARLY AFTERNOON. MDB //DISCUSSION...UPDATED 16Z... LINE OF STORMS NOW ORIENTED FROM W OF KENW TO KDKB TO W OF KVYS AND MOVING EAST. SOUTHERN EXTENT HAS INCREASED SO HAVE SO HAVE HIGHER CONFIDENCE IN MDW BEING AFFECTED AND HAVE AMENDED TO SHOW THIS. OTHERWISE ORD/DPA WILL BE AFFECTED AS WELL. WILL LIKELY NEED TO HIT THE TS HARDER AT GYY WITH ARRIVAL TOWARD 1830/19Z OR SO. EXPECT WIND SHIFT TO THE N/NNW WITH THE STORMS WITH WINDS THEN DIMINISHING AND BECOMING VARIABLE FROM THE NORTH AND EAST...BEFORE EVENTUALLY BECOMING SOUTHERLY AGAIN. MDB FROM 12Z... LARGE COMPLEX OF THUNDERSTORMS OVER THE UPPER MIDWEST EARLY THIS MORNING WAS SLOWLY SLIDING SOUTHEAST. REGIONAL RADAR INDICATED A LINE OF THUNDERSTORMS STILL ASSOCIATED WITH THIS COMPLEX STRETCHING FROM FAR NORTHEAST IOWA INTO WEST CENTRAL WISCONSIN. GUIDANCE INDICATES THAT THIS LINE WILL BEGIN TO WEAKEN AS IT CONTINUES TO SLIDES SOUTHEAST. CURRENT THINKING IS THAT SOME REMNANTS OF THIS LINE OF THUNDERSTORMS MAY ARRIVE LATER THIS MORNING. THE TIMING WOULD BE INTO RFD ARND 16Z THEN FURTHER EAST AT ORD/MDW/DPA/GYY CLOSER TO 18Z ARRIVAL. WITH SOME HEATING AHEAD OF THIS LINE OVER NORTHERN IL/NORTHWEST IN AIRFIELDS...THIS MAY AID IN MAINTAINING THIS LINE OF CONVECTION. AT THIS TIME HAVE OPTED TO GO WITH A VCTS RATHER THAN A PREVAILING MENTION. BUT THAT MAY NEED TO BE CHANGED FOR THE 14Z AMD. SOUTHERLY WINDS WILL CONTINUE THRU MUCH OF THE DAY WITH OCCASIONAL GUSTS BEGINNING TO OCCUR LATER THIS MORNING TO AROUND 20 KT. CLOUD DECKS SHUD BE AROUND 5KFT AGL...AND MAY SLOWLY GROW IN COVERAGE THROUGHOUT THE AFT FROM A SCT TO BKN. GUIDANCE IS THEN REDEVELOPING A LINE OF SHOWERS/THUNDERSTORMS LATE THIS AFTN/EVE ALONG A REMNANT BOUNDARY FROM THIS MORNING CONVECTION. SOME OF THESE THUNDERSTORMS COULD BE STRONG TO SEVERE...WITH THE MAIN HAZARDS BEING WIND/HAIL. SOUTHERLY WINDS PERSIST OVERNIGHT AND DIMINISH TO ARND 10KT...WITH SOME TURNING TO THE SOUTHWEST EXPECTED OVERNIGHT TOWARDS DAYBREAK SAT. OVERALL EXPECT VFR CONDS THROUGHOUT...HOWEVER WITH ANY THUNDERSTORM ACTIVITY THIS COULD EASILY BE LIMITED TO MVFR. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN TS TIMING. * HIGH CONFIDENCE IN WIND SHIFT TO NW WITH GUSTS...MEDIUM CONFIDENCE IN GUSTS SPEEDS...HIGH CONFIDENCE IN IFR VSBY. * MEDIUM CONFIDENCE IN WIND TRENDS BEHIND MAIN LINE OF STORMS...LOW CONFIDENCE IN TIMING OF DIRECTION CHANGES. * LOW-MEDIUM CONFIDENCE IN COVERAGE/DURATION OF LINGERING -RA/EMBEDDED TS EARLY THIS AFTERNOON. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. SUNDAY...MAINLY VFR. CHC THUNDERSTORMS LATE. MONDAY THROUGH THURSDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE VFR. BEACHLER && .MARINE... 240 AM CDT MAIN CONCERN FOR LAKE MICHIGAN WILL BE POTENTIAL FOR FOG DEVELOPMENT AND TIMING...ALONG WITH CHANCES FOR THUNDERSTORMS. AT THIS TIME THERE DOES NOT APPEAR TO BE ANY WIND/WAVE HAZARDS EXPECTED IN THE NEXT SEVERAL DAYS. HIGH PRESURE ANCHORED ACROSS THE WESTERN ATLANTIC OCEAN ALONG WITH A BROAD LOW PRESSURE ANCHORED OVER THE CENTRAL PLAINS...WILL MAINTAIN THE SOUTHERLY FLOW OVER THE LAKE. IN ADDITION VERY WARM AIR WILL SLIDE OVER THE COOLER OPEN WATERS OF THE LAKE...AND HELP TO KEEP WAVES FROM BUILDING TO LARGE. THE GRADIENT THIS AFTERNOON DOES INCREASE WHICH MAY ALLOW WINDS TO INCREASE TO AROUND 20-25KT FOR THE NORTHERN HALF OF THE LAKE...HOWEVER WAVES SHOULD ONLY BUILD TO 2 TO 4 FT. AT TIMES WINDS MAY GUST TO 25 KT FURTHER SOUTH THIS AFTERNOON. THUNDERSTORMS ARE FORECAST FOR THE NEXT SEVERAL DAYS...HOWEVER THESE DO NOT APPEAR TO BE AN ALL DAY OR NIGHT THING. BUT WINDS/WAVES WILL BE HIGHER IN AND AROUND ANY THUNDERSTORMS THAT DO SLIDE ACROSS THE LAKE. AS MENTIONED EARLIER ABOUT THE FOG DEVELOPMENT. IT DOES APPEAR THAT WITH ENOUGH WIND THIS AFTERNOON FOG WILL HOLD OFF UNTIL PERHAPS LATE TONIGHT OR POSSIBLY SATURDAY. A WARM FRONT WILL LIFT NORTH OVER THE LAKE...WITH FOG DEVELOPMENT EXPECTED JUST AFTER PASSAGE. THIS STILL APPEARS TO FAVOR THE NORTHERN PORTIONS OF THE LAKE AND AT TIMES COULD BE DENSE. ONCE FOG DEVELOPS IT COULD EASILY LINGER THROUGH EARLY NEXT WEEK AS THE WINDS ARE NOT EXPECTED TO BE VERY STRONG. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1232 PM CDT FRI JUN 21 2013 .SHORT TERM.../TODAY/... ISSUED AT 331 AM CDT FRI JUN 21 2013 LARGE CONVECTIVE COMPLEX OVER MN BEGINNING TO TURN SOUTHEAST AND BATTLING H700 CAP AT THIS TIME AS IT DOES. CONTINUED CONCERNS EARLY THIS MORNING AS TO HOW FAR SOUTH THIS WILL TURN BEFORE THE CAP BECOMES TOO STRONG FOR ANY FURTHER SOUTH DRIFT. COLD POOL HAS DEVELOPED WITH SFC WINDS AND OUTFLOW PROPAGATING BACK TO THE SOUTHWEST. THIS SUGGESTS THAT IT MAY CLIP NORTHERN IOWA WITH STORMS THIS MORNING BETWEEN 4 AND 8 AM...IF THE LINE IS ABLE TO CONTINUE BREAKING THE CAP BACK TO THE SOUTHWEST...MAY SEE ADDITIONAL STORMS INTO CENTRAL IOWA. CURRENT MESO MODELS ARE LACKING IN ANY AGREEMENT BUT THE HRRR HAS BEEN MORE REALISTIC WITH FEATURES SO FAR AND IT ONLY SCRAPES NORTHERN IOWA EARLY TODAY WITH THIS COMPLEX OF STORMS. ONCE SYSTEM MOVES EAST WILL BE LEFT WITH ANOTHER VERY WARM AND HUMID DAY. THIS WILL RESULT IN HIGHS IN THE UPPER 80S TO LOWER 90S THIS AFTERNOON WITH SOUTH WINDS AND GENEROUS DEW POINTS IN THE 60S AND LOWER 70S. MORE CONVECTION MAY DEVELOP THIS AFTERNOON NORTH OF HIGHWAY 20 ALONG ANY LINGERING OUTFLOW BOUNDARY FROM THE OVERNIGHT CONVECTIVE COMPLEX AND THIS IS MORE LIKELY AFT 19Z THROUGH THE REMAINDER OF THE AFTERNOON. WILL BE MONITORING CONVECTIVE TRENDS THROUGH THE MORNING HOURS. .LONG TERM.../TONIGHT THROUGH THURSDAY/... ISSUED AT 331 AM CDT FRI JUN 21 2013 EXTENDED FORECAST CONTINUES TO CENTER AROUND LARGE UPPER LEVEL LOW ACROSS PAC NW...AND SURFACE LOW ACROSS NORTHERN PLAINS WITH WARM FRONT IN SOUTHERN SD/MN. THIS WILL CONTINUE TO BE THE FOCUS FOR AFTERNOON CONVECTION...AND MODELS AGAIN SUGGEST MCS DEVELOPMENT OVERNIGHT. HOWEVER..AS UPPER LOW PUSHES EASTWARD...RIDGE PUSHES NORTH OF IOWA...AND UPPER LEVEL FLOW IS EXPECTED TO TAKE ANY OVERNIGHT MCS NORTH OF IOWA. THOUGH...CURRENTLY ONGOING MCS ACROSS SOUTHERN MINNESOTA MAY PRODUCE AN OUTFLOW BOUNDARY INTO NORTHERN IOWA...WHICH MAY ALLOW FOR TRACK OF MCS TO BE FURTHER SOUTH INTO NORTHERN IOWA. THOUGH GIVEN STRENGTH OF UPPER LEVEL LOW...STILL PREFER NORTHERN SOLUTION...AND HAVE KEPT POPS CONFINED TO NORTHERN IOWA OVERNIGHT. SATURDAY NIGHT LOOKS TO BE ACTIVE AS WELL...WITH FRONTAL BOUNDARY PUSHING INTO NORTHWESTERN IOWA. THIS COULD BE FOCUS FOR AFTERNOON THUNDERSTORM DEVELOPMENT...WITH AGAIN OVERNIGHT MCS...THOUGH WITH INFLUENCE FROM UPPER LOW MODELS CONTINUE TO PULL CONVECTION NORTHWEST OF IOWA...AND HAVE KEPT POPS AGAIN CONFINED TO THE NORTH...AS WARM MID LEVEL TEMPS WILL HELP TO KEEP CAP ACROSS MOST OF CENTRAL IOWA. SUNDAY FRONTAL BOUNDARY WILL PUSH INTO CENTRAL IOWA...WITH ENOUGH FORCING TO LEAD TO PROLONGED PERIODS OF PRECIPITATION THROUGH THE DAY AND OVERNIGHT...THOUGH WILL PUSH EAST OF REGION BY MONDAY. SHORTWAVE PUSHING ACROSS NE/SD BORDER WILL BRING ADDITIONAL SHOT OF PRECIPITATION FOR TUESDAY...LINGERING IN THE EAST THROUGH WEDNESDAY. TEMPERATURES WILL BE HOT THROUGH THE BEGINNING OF THE PERIOD AS SOUTHERLY SURFACE FLOW AND WAA PERSISTS UNDER RIDGE. THIS WILL ALLOW TEMPERATURES TO CLIMB INTO THE 90S ACROSS MUCH OF THE CWA...THOUGH COULD GO HIGHER THAN GOING IF ABLE TO MIX WELL. HEAT INDEX VALUES WILL BE NEAR 100 THROUGH THE WEEKEND IN THE AFTERNOONS. THIS WILL BE THE FIRST EXPOSURE SUMMER LIKE HEAT/HUMIDITY FOR MUCH OF THE REGION...AND MAY BE TAXING. HOWEVER...OVERNIGHT TEMPERATURES EXPECTED TO COOL INTO THE 70S AND WILL PROVIDE SOME RELIEF. IN ADDITION...BEHIND FRONTAL BOUNDARY MONDAY TEMPERATURES WILL COOL SOMEWHAT...BUT WILL QUICKLY REBOUND BACK INTO THE UPPER 80S AND LOW 80S FOR MOST OF THE REMAINDER OF THE PERIOD. && .AVIATION...21/18Z ISSUED AT 1232 PM CDT FRI JUN 21 2013 PROBLEMATIC CONVECTIVE FORECAST COMPLICATES THE TAFS THROUGH TONIGHT. CURRENTLY WDLY SCT SHRA/TSRA ARE AFFECTING OR APPROACHING KFOD/KDSM/KOTM...BUT THEY ARE SMALL AND OF MINIMAL/BRIEF IMPACT SO HAVE ADVERTISED ONLY WITH VCTS THIS AFTN AT THOSE TERMINALS. MEANWHILE A LARGE CLUSTER OF TSRA ACROSS CTL SDAK IS APPROACHING AND MAY IMPACT THE NORTHERN TERMINALS OVERNIGHT. THESE STORMS COULD HAVE A MORE SUBSTANTIAL IMPACT...HOWEVER UNCERTAINTY IN CONVECTIVE EVOLUTION IS HIGH AND THEY MAY NOT REACH THE AREA AT ALL. THUS HAVE ALSO GONE WITH VCTS FOR THAT SCENARIO. BR IS ALSO EXPECTED LATE TONIGHT...ESPECIALLY ACROSS THE NORTH...BUT DUE TO UNPREDICTABILITY OF OTHER VARIABLES HAVE ONLY INCLUDED 6SM AT THIS TIME. EXPECT FREQUENT TAF UPDATES LATER TODAY AND TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...AWB AVIATION...LEE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
217 PM MDT FRI JUN 21 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 216 PM MDT FRI JUN 21 2013 AS OF 3 PM CDT...2 PM MDT...SKIES ACROSS THE TRI-STATE WERE CLEAR ALBEIT A LITTLE HAZY FROM SMOKE THAT CONTINUES TO STREAM IN FROM FIRES IN SOUTH CENTRAL COLORADO. SOME CUMULUS AND TOWERING CUMULUS COULD BE SEEN ON VISIBLE SATELLITE IMAGERY JUST NORTH OF AKRON...COLORADO. SOUTH WINDS HAVE PICKED UP MAINLY EAST OF A LINE FROM TRENTON...NEBRASKA TO COLBY AND LEOTI KANSAS AS A SURFACE LOW PRESSURE SYSTEM DEEPENS TO THE WEST. TEMPERATURES RANGED FROM THE LOW 90S IN EAST COLORADO TO NEAR 100 ACROSS SOME PARTS OF KANSAS AND SOUTHWEST NEBRASKA. VERY DRY AIR WAS ALSO STARTING TO MOVE IN FROM THE SOUTHWEST. SIMILAR TO YESTERDAY...ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A DRYLINE. SURFACE CONVERGENCE IS BEGINNING TO APPEAR IN THE SURFACE WIND FIELD ALONG THE DRYLINE WHICH WILL BE THE FOCUS OF STORM DEVELOPMENT. THE HRRR AND NAM MODELS SUGGEST STORM INITIATION WILL OCCUR IN FAR WESTERN KANSAS. STORMS SHOULD BE CONFINED MAINLY ALONG AND EAST OF A LINE FROM YUMA COLORADO TO GOODLAND KANSAS TO TRIBUNE KANSAS AND WEST OF A LINE FROM MCCOOK NEBRASKA TO RUSSELL SPRINGS KANSAS. ANY STORM THAT IS ABLE TO DEVELOP WILL BE STRONG TO SEVERE WITH LARGE HAIL AND DAMAGING WINDS AS THE MAIN THREATS. FOR TONIGHT...GUSTY WINDS WILL CONTINUE A LOW LEVEL JET DEVELOPS OVER THE EASTERN HALF. WINDS SHOULD BE BELOW WIND ADVISORY CRITERIA WITH THE STRONGEST WINDS REMAINING TO THE SOUTH OVER SOUTHWEST AND SOUTH CENTRAL KANSAS. LOWS WILL STRUGGLE TO FALL TONIGHT WITH THE ATMOSPHERE IN A MIXED STATE SO HAVE GONE ABOVE GUIDANCE FOR LOWS. TONIGHTS TEMPERATURE FORECAST IS VERY SIMILAR TO WHAT ACTUALLY OCCURRED LAST NIGHT. FOR TOMORROW...A REPEAT OF TODAY IS EXPECTED FOR THE MOST PART. TEMPERATURES ARE NOT EXPECTED TO BE AS HOT AS TODAY WITH HIGHS ONLY REACHING THE MID TO UPPER 90S WITH A FEW SPOTS REACHING 100. A WEAK FRONT WILL MOVE INTO THE AREA FROM THE NORTH...RESULTING IN MAINLY A WIND SHIFT WITH EVER SO SLIGHTLY COOLER TEMPERATURES. WITH A DRYLINE STILL IN PLACE...ISOLATED THUNDERSTORMS ARE POSSIBLE AGAIN FOR TOMORROW. ANY STORMS THAT ARE ABLE TO DEVELOP WOULD LIKELY BECOME SEVERE. THERE IS A SLIGHT RISK FOR SEVERE WEATHER ACROSS SOUTHWEST NEBRASKA TOMORROW AND THAT SEEMS REASONABLE GIVEN THE LOCATION OF THE FRONT TOMORROW. THE FRONT SHOULD PROVIDE A BETTER FOCUS FOR THUNDERSTORM DEVELOPMENT OVER THE NORTHERN THIRD OF THE FORECAST AREA. GUSTY SOUTH WINDS ARE EXPECTED AGAIN WITH A LOW PRESSURE DEEPENING TO THE WEST. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 215 PM MDT FRI JUN 21 2013 A SIGNIFICANT CHANGE IN THE UPPER PATTERN WILL TAKE PLACE DURING THIS EXTENDED PERIOD. THE CURRENT SOUTHWEST FLOW ALOFT ACCOMPANIED BY NUMEROUS MINOR DISTURBANCES WILL TRANSITION TO A BUILDING UPPER RIDGE...STARTING OVER NM/AZ TUESDAY AND ULTIMATELY ENCOMPASSING ALL OF THE CENTRAL ROCKIES BY THE END OF THE WEEK. THERE STILL LOOKS TO BE A COUPLE OF OPPORTUNITIES FOR STORMS COMING OUT OF COLORADO AND MOVING ACROSS THE CWA SATURDAY AND SUNDAY EVENING AS WEAK SHORT WAVE TROUGHS MOVE THROUGH THE FLOW. AFTER THAT...PRECIP POTENTIAL WILL DIMINISH AS THE UPPER RIDGE AND WARMING MID-LEVEL TEMPS BEGIN TO DOMINATE. TEMPERATURES ARE EXPECTED TO REMAIN WELL ABOVE NORMAL DURING THE PERIOD WITH HIGHS MOSTLY IN THE MIDDLE 90S TO NEAR 100 AND LOWS IN THE 60S TO NEAR 70. CURRENT EXTENDED GUIDANCE BEYOND THIS PERIOD SUGGESTS THE UPPER RIDGE WILL CONTINUE TO BUILD NORTH TOWARD IDAHO BY NEXT WEEKEND. IF THAT PANS OUT...THE UPPER FLOW WILL BECOME NORTHWEST OVER THE CWA POSSIBLY INCREASING THE CHANCE FOR LATE DAY STORMS MOVING SOUTHEAST OFF THE CHEYENNE RIDGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1115 AM MDT FRI JUN 21 2013 VFR CONDITIONS ARE FORECAST FOR THE NEXT 24 HOURS AT KMCK AND KGLD. IT IS POSSIBLE THAT ISOLATED...HIGH-BASED THUNDERSTORMS DEVELOP THIS AFTERNOON ALONG A DRYLINE AND MOVE TO THE EAST. COVERAGE SHOULD BE FAIRLY SPARSE SO DID NOT MENTION ANY THUNDER IN THE TAFS. GUSTY SOUTH WINDS WILL BEGIN THIS AFTERNOON AND CONTINUE WELL INTO THE NIGHT. WINDS AT KGLD WILL VEER TO THE NORTHWEST TOMORROW MORNING AS A WEAK FRONT MOVES IN WHILE WINDS AT KMCK SHOULD REMAIN FROM THE SOUTH. && .FIRE WEATHER... ISSUED AT 216 PM MDT FRI JUN 21 2013 CRITICAL FIRE WEATHER CONDITIONS ARE DEVELOPING TO THE SOUTHWEST...MAINLY OVER GREELEY AND WALLACE COUNTIES KANSAS AND CHEYENNE AND KIT CARSON COUNTIES IN COLORADO. EVEN THOUGH RED FLAG CRITERIA WILL BE MET FOR THESE LOCATIONS TODAY FOR WIND AND RELATIVE HUMIDITY...RECENT RAINFALL AND HIGHER FUEL MOISTURE CONTENT ARE PREVENTING EXPLOSIVE FIRE WEATHER CONDITIONS FROM BECOMING A PROBLEM. THEREFORE...HAVE OPTED NOT TO ISSUE A RED FLAG WARNING. THE SAME STORY WILL REPEAT ITSELF AGAIN TOMORROW WITH LOW RELATIVE HUMIDITIES FILTERING IN FROM THE SOUTHWEST AND WINDS INCREASING BEHIND THE DRYLINE IN THE AFTERNOON. FUELS COULD BE MORE RIPE FOR FIRE POTENTIAL TOMORROW AFTER A COUPLE HOT DAYS WITH LITTLE RAINFALL BUT THINKING THAT FUEL MOISTURE WILL STILL BE HIGH ENOUGH THAT A RED FLAG WARNING WILL NOT BE WARRANTED. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...RRH LONG TERM...DLF AVIATION...RRH FIRE WEATHER...RRH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
346 PM CDT FRI JUN 21 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 345 PM CDT FRI JUN 21 2013 ANOTHER ACTIVE SHORT TERM IS EXPECTED...WITH POTENTIAL FOR BOTH ANOTHER SEVERE WEATHER EVENT AND A SIGNIFICANT FLASH FLOOD EVENT OVER SRN MN BEING CLOSELY MONITORED TONIGHT. WARM FRONTAL BOUNDARY AT 3PM STRETCHES FROM ROUGHLY MARSHALL OVER TOWARD RED WING. VERY UNSTABLE AIRMASS COMBINED WITH A WAVE THAT CAME OUT OF THE BLACK HILLS THIS MORNING HAS SEVER CLUSTER OF STORMS OVER SODAK THAT IS RAPIDLY APPROACHING SW MN. THE SYSTEM IS STARTING TO BOW...WITH HURON REPORTING A WIND GUST OF 87 MPH. HAVE BEEN LEANING ON THE HRRR HEAVILY ALL DAY TO TRACK THIS SYSTEM ACROSS THE AREA. EXPECT THESE STORMS TO BASICALLY FOLLOW THE WARM FRONT AND 850-300 THICKNESS LINES TO THE ESE ACROSS SRN MN. TORNADO/LARGE HAIL TREAT WILL BE HIGHEST ALONG THE SODAK BORDER...WITH THE THREAT TRANSITIONING OVER TO MORE OF A WIND THREAT AS YOU HEAD EAST. WOULD NOT BE SURPRISED IF BY 5 OR 6 PM WE ARE COORDINATING WITH THE SPC FOR A SVR THUNDERSTORM WATCH TO THE EAST OF THE CURRENT TOR WATCH. FOR TONIGHT THOUGH...THE REAL BIG CONCERN IS THE POTENTIAL FOR A SIGNIFICANT RAINFALL/FLASH FLOODING EVENT ACROSS SRN MN. THE RAP HAS THE NOSE OF A PERSISTENT 40-50 KT LLJ COMING UP OUT OF THE PLAINS AND REMAINING MORE OR LESS STATIONARY INTO SW MN. AS THE HRRR SHOWS...WITH 3000-5000 J/KG OF MUCAPE REMAINING IN PLACE WITH THE LLJ...THE PROBABILITY FOR ADDITIONAL TSRA DEVELOPMENT BACK INTO THE SD/NEB/IA AREA THROUGH THE NIGHT WILL BE HIGH. THIS WILL LEAD TO A THREAT FOR TRAINING OF STORMS TONIGHT...WITH THE POTENTIAL FOR SOME RATHER SIGNIFICANT RAINFALL TOTALS IN EXCESS OF 6 INCHES POSSIBLE FOR TONIGHT. GIVEN THE POTENTIAL...HAVE ISSUED A FLASH FLOOD WATCH FOR AREAS ALONG AND SOUTH OF AN APPLETON TO CHIPPEWA FALLS LINE...WITH THE POTENTIAL FOR SEEING MULTIPLE ROUNDS OF STORMS IS HIGHEST. GIVEN THE SOUTHERN POSITION OF THE WARM FRONT...LESSER AMOUNTS OF RAINFALL ARE CURRENTLY ANTICIPATED OVER CENTRAL MINNESOTA INTO NW WISCONSIN. LIKE TODAY...EXPECT ACTIVITY TO WIND DOWN THROUGH THE MORNING ACROSS THE MPX AREA...WITH MUCH OF THE LATE MORNING INTO THE EARLY AFTERNOON REMAINING DRY. THE BIG DIFFERENCE THOUGH ON SATURDAY TO THE PAST TWO DAYS...IS THE SYNOPTIC COLD/STATIONARY FRONT AND LOW PRESSURE SYSTEM WILL BE FARTHER EAST. BY THE AFTERNOON...MODELS SHOW A LEE SIDE LOW DEVELOPING OVER ERN COLORADO...WITH A STATIONARY FRONT/PRESSURE TROUGH EXTENDING TO THE NORTHEAST TOWARD WRN MN. WITH THE SYNOPTIC FEATURES FARTHER EAST TOMORROW...THIS SHOULD INCREASE THE CHANCES FOR THUNDERSTORMS DEVELOPING IN THE AFTERNOON ACROSS THE MPX AREA...WHICH WILL LEAD TO A HIGHER PROBABILITY FOR SEEING TORNADOES OR HAIL DURING THE AFTERNOON...BEFORE ANOTHER POTENTIAL ROUND OF STORMS GOING INTO SATURDAY NIGHT. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CDT FRI JUN 21 2013 NO SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST...WITH SEVERE AND HYDRO CONCERNS CONTINUING THROUGH EARLY NEXT WEEK. THE UPPER LEVEL LOW WILL LINGER JUST TO THE WEST...WITH THE SURFACE TROUGH INCHING EVER CLOSER TO WESTERN MINNESOTA BY THE WEEKEND...AND THE FRONTAL BOUNDARY STALLED OUT EAST/WEST ACROSS THE FORECAST AREA ONLY TO OSCILLATE NORTH/SOUTH WITH EACH CONVECTIVE OUTFLOW BOUNDARY. THE TROPICAL AIRMASS WILL REMAIN IN PLACE THROUGH EARLY NEXT WEEK...WITH PWAT VALUES IN THE 1.75 TO 2.00 INCH RANGE. SREF 21.09 MLCAPE PLUMES CONTINUE TO SHOW 2500 TO 4000J/KG DURING THE AFTERNOON...AND THIS SEEMS REASONABLE CONSIDERING WHAT IS CURRENTLY GOING ON ACROSS SOUTHWEST MINNESOTA. DEEP LAYER SHEAR WILL ONLY BE IN THE 25KT RANGE...BUT THE SEVERE WEATHER REMAINS A CONCERN SINCE THE STORMS MAY BE ABLE TO MODIFY THEIR OWN ENVIRONMENT AS IS THE CASE THIS AFTERNOON ACROSS EASTERN SOUTH DAKOTA. AS THE SURFACE TROUGH SLOWLY PROGRESSES EASTWARD...THE POTENTIAL FOR AFTERNOON CONVECTION WILL INCREASE AS WELL. THEREFORE THE MISSISSIPPI RIVER VALLEY MAY TRANSITION FROM A PURELY NOCTURNAL EVENT AS WAS THE CASE LAST NIGHT...TO MORE OF A AFTERNOON AND EVENING FOCUS. FORECAST MODELS CONTINUE TO SHOW A SHORTWAVE MOVING ACROSS NORTHERN MINNESOTA SATURDAY NIGHT...SO IF STORMS DO NOT DEVELOP TOMORROW AFTERNOON THEY WILL CERTAINLY FORM AHEAD OF THAT WAVE. ANOTHER WAVE FOLLOWS FOR SUNDAY EVENING...SO COULD SEE SOME QUICK REDEVELOPMENT DURING THE DAY ON SUNDAY. LOOKING AHEAD...BOTH THE GFS AND ECMWF TRANSITION TO A MORE ZONAL PATTERN WITH THE H250 JET STRADDLING THE INTERNATIONAL BORDER...AND CONTINUED CHANCES FOR POPS THROUGH THE MIDDLE OF THE WEEK. THE UPPER LEVEL RIDGE TRIES TO BUILD ACROSS THE ROCKIES BY LATE NEXT WEEK...BUT CONFIDENCE IS LOW IN THE DEVELOPMENT OF THIS FEATURE GIVEN THE CONTINUED DELAYED ONSET WITH EACH MODEL RUN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 127 PM CDT FRI JUN 21 2013 WINDS STARTING TO SETTLE BACK TO THE EAST IN THE WAKE OF LAST NIGHTS SYSTEM. GOING OF THE H7 TEMP MESOANALYSIS...BELIEVE THE MPX AREA IS CAPPED FOR ANY CONVECTION THIS AFTERNOON...INSTEAD WE ARE WAITING ON THE GROWING AREA OF STORMS OVER SODAK FOR MORE TSRA ACTIVITY. RELIED HEAVILY ON THE HRRR TO TIME THESE SODAK STORMS ACROSS THE TERMINALS TONIGHT. AT THE MOMENT...IS LIKELY THEY MAY SKIRT JUST TO THE SOUTH OF AXN/STC...SO HAVE NO TEMP GROUPS THERE. AFTER THAT...HRRR IS INDICATING STORMS WILL CONTINUE TO FIRE ON THE NOSE OF THE LLJ OVER SE SODAK AND CONTINUE TO TRACK EAST...SO THERE IS THE POTENTIAL FOR RWF IN PARTICULAR TO SEE AT LEAST A COUPLE OF ROUNDS OF STORMS TONIGHT. MVFR CIGS WILL LINGER ACROSS WRN WI FOR THE NEXT COUPLE OF HOURS. SHOULD THEN SEE VFR CONDS UNTIL NEXT ROUND OF STORMS MOVE IN...WITH CIGS EXPECTED TO BEHAVE VERY SIMILAR TO HOW THEY DID OVERNIGHT INTO THIS PAST MORNING. KMSP...HRRR HAS BEEN CONSISTENT WITH TRACKING ANOTHER STRONG TO SEVERE LINE OF STORMS ACROSS MSP THIS EVENING...THOUGH A BIT EARLIER TONIGHT...WITH THE 3Z-6Z PERIOD LOOKING LIKE THE MOST LIKELY WINDOW FOR ANOTHER ROUND OF STORMS. HRRR IS SHOWING STORMS CONTINUING TO FIRE THROUGH THE NIGHT WEST OF THIS FIRST LINE. CURRENT THINKING IS THAT ADDITIONAL CONVECTION WILL BE MAINLY SOUTH OF THE FIELD...BUT IF THIS ADDITIONAL ACTIVITY DOES GO FARTHER NORTH THAN CURRENTLY INDICATED...THEN THERE COULD BE SIGNIFICANT IMPACTS DUE TO CONVECTION FOR MUCH OF THE NIGHT INTO SAT MORNING. BY SATURDAY AFTERNOON...MOIST UNSTABLE AIRMASS WILL LEAD TO THE POTENTIAL FOR MORE DIURNALLY DRIVEN CONVECTION TO END THE TAF. /OUTLOOK FOR KMSP/ SUN...TSRA LIKELY. VFR OUTSIDE OF TSRA. WINDS SSW 10-15 KTS. MON...CHC TSRA. VFR OUTSIDE OF TSRA. WINDS S 5-10 KTS. TUE...CHC TSRA. VFR OUTSIDE OF TSRA. WINDS SSE 10-15 KTS. && .HYDROLOGY... ISSUED AT 345 PM CDT FRI JUN 21 2013 AS ALLUDED TO EARLIER PWATS WILL BE IN THE 90TH PERCENTILE THOUGH EARLY NEXT WEEK. THE AREA IS INCREASINGLY VULNERABLE TO BOTH FLASH FLOODING...AND RIVER FLOODING GIVEN THE WIDESPREAD RAINFALL AMOUNTS OF 2-4 INCHES FALLING LAST NIGHT. THE EAST/WEST FRONTAL BOUNDARY SUPPORTS TRAINING THUNDERSTORMS...AND THE H925 MOISTURE TRANSPORT SURGES NORTHWARD OVERNIGHT AS THE LOW LEVEL JET DECOUPLES FROM THE BOUNDARY LAYER. CONTINGENCY FORECAST BASED OFF DIFFERENT QPF SCENARIOS SHOW THE POTENTIAL FOR SIGIFICANT FLOODING BY EARLY NEXT WEEK ALONG THE QUICKER RESPONSE RIVERS...AND EVENTUALLY THE LARGER MAIN STEMS OF THE MINNESOTA AND MISSISSIPPI RIVER. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...FLASH FLOOD WATCH FROM 9 PM CDT THIS EVENING THROUGH SATURDAY AFTERNOON FOR MNZ054-056>060-062>070-073>078-082>085- 091>093. WI...FLASH FLOOD WATCH FROM 9 PM CDT THIS EVENING THROUGH SATURDAY AFTERNOON FOR WIZ023>028. && $$ SHORT TERM...MPG LONG TERM...JRB AVIATION...MPG HYDROLOGY...JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
127 PM CDT FRI JUN 21 2013 .UPDATE... ISSUED AT 1142 AM CDT FRI JUN 21 2013 LARGE MCS FROM LAST NIGHT HAS NOW PUSHED INTO ERN WI AND NRN IL. IN ITS WAKE...STRONG OUTFLOW BOUNDARY HAS DEVELOPED IN IOWA FROM ROUGHLY THE QUAD CITIES BACK TO AROUND THE SIOUX CITY AREA. BASED ON WIND FIELD...MAIN WARM FRONTAL BOUNDARY STRETCHES FROM SOUTH OF CANBY SOUTHEAST TOWARD ST. JAMES AND ALBERT LEA. WITH THE MORNING UPDATE...DID CUT BACK SIGNIFICANTLY ON POPS THROUGH 00Z AS VERY FEW HI-RES CAMS SHOW ANY CONVECTION FORMING DURING THE DAYLIGHT HOURS IN MN/WI. COUPLE OF REASONS FOR THIS APPEARS TO BE THE FACT THAT THE ATMO IS PRETTY WORKED OVER AFTER LAST NIGHT /AS SEEN WITH 12Z KMPX SOUNDING AND OUTFLOW BOUNDARY DOWN IN IA/...ALONG WITH THE PRESENCE OF A CAPPING EML MOVING IN FROM NEB...WITH THE 16Z SPC MESO ANALYSIS SHOWING THE +12C ISOTHERM AT H7 CLEAR UP TO THE US-212 CORRIDOR IN MN. FOR THIS REASON...STILL FEEL THAT THE MPX AREA WILL REMAIN HIGH AND DRY THROUGH TODAY. HOWEVER...YOU CAN NOT COMPLETELY RULE OUT SOMETHING FORMING ALONG WITH WARM FRONT LATER THIS AFTERNOON /AS MENTIONED IN THE SPC DAY1 OUTLOOK/. IF SOMETHING WERE TO DEVELOP...THEN THE RISK FOR LARGE HAIL...DAMAGING WINDS...AND POSSIBLY EVEN A TORNADO WILL EXIST. ONCE AGAIN HOWEVER...MORE ROBUST CONVECTION IN THE FORM OF AN MCS IS EXPECTED TONIGHT. BASED ON THE HRRR AND 21.12 MPXWRF...THIS MCS LOOKS LIKE IT WILL EVOLVE FROM THE LARGE THUNDERSTORM CURRENTLY OVER THE BADLANDS OF SODAK. TO GO ALONG WITH THESE...THE 9Z MEMBERS OF THE HOPWRF SHOW A SIMILAR TREND OCCURRING WITH CONVECTION THIS AFTERNOON/EVENING AS WELL. LIKE LAST NIGHT...0-1KM SHEAR WILL BE INCREASING AS NOCTURNAL LLJ INCREASES IN STRENGTH...SO ANOTHER SEVERE BOW ECHO LOOKS LIKELY...JUST A MATTER OF HOW FAR NORTH IT TRACKS. GIVEN THE EXPECTATION OF ANOTHER MCS...MAY HAVE TO HOIST ANOTHER FLASH FLOOD WATCH FOR TONIGHT ONCE A BETTER FEEL FOR WHERE THIS NEXT MCS WILL TRACK CAN BE DETERMINED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 422 AM CDT FRI JUN 21 2013 WE WILL KEEP THIS DISCUSSION SHORT AND SWEET. IT HAS BEEN A LONG NIGHT. A MATURE MCS IS NOW IN THE EASTERN THIRD OF THE FORECAST AREA AFTER TRACKING ACROSS THE ENTIRE STATE OF MN AND INTO WI THROUGH THE OVERNIGHT HOURS. THERE IS LITTLE CHANGE IN THE LARGE- SCALE FLOW REGIME ACROSS MN/WI OVER THE NEXT 24-36 HOURS. SOUTHWESTERLY FLOW ALOFT WITH THE RIDGE OVERHEAD. 925MB-850MB MOISTURE TRANSPORT EXPLODED LAST NIGHT AND WE SAW THE RESULT WITH WIDESPREAD SEVERE WEATHER. THERE REALLY IS NOT MUCH DIFFERENCE WITH THE UPCOMING SHORT TERM PATTERN. THERE IS DECENT CONSENSUS AMONGST THE NAM/GFS/ECMWF WITH THE DEVELOPMENT OF ANOTHER CONVECTIVE COMPLEX LATE IN THE AFTERNOON AND EVENING NEAR THE MN/SD BORDER AND MARCHING THAT EAST WITH TIME. MODERATE TO HIGH INSTABILITY VALUES WILL NOT BE A PROBLEM AS WE RELOAD TODAY AND THE DEEP LAYER SHEAR WILL BE STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION. SOME OF THE HIGHER RESOLUTION /CONVECTIVE ALLOWING MODELS/ WE LOOK AT FOCUS MORE OF THE CONVECTION TO THE SOUTH IN NE/IA. THIS WOULD BE FARTHER SOUTH THAN THE NAM/ECMWF/GFS/. ADMITTEDLY SO...THESE THREE RUNS DO HAVE SOME DIFFERENCES. THE GFS AND ECMWF ARE SIMILAR IN THE LOCATION OF CONVECTIVE INITIATION. THE NAM IS FARTHER SOUTH BUT THE GFS AND ECMWF ARE SIMILAR. HOWEVER...THE GFS IS FASTER. WE WILL HAVE TO PAY ATTENTION TO THE OUTFLOW FROM THIS MORNING`S CONVECTION...THAT COULD BE A TRIGGER TODAY. HOWEVER...THERE SHOULD BE AN EAST-WEST BOUNDARY...SO FLASH FLOODING WILL AGAIN BE A MAJOR THREAT ALONG WITH THE HAIL AND WIND...ESPECIALLY GIVEN THE SATURATED SOILS AFTER THIS MORNING. SO IN SUMMARY...GET READY TO DO THIS ALL AGAIN TONIGHT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 422 AM CDT FRI JUN 21 2013 POTENT RIDGE OVER THE WRN CONUS WITH LONGWAVE TROUGHING OVER THE WRN CONUS WILL PROMOTE PROGRESSIVE SWLY FLOW OVER THE UPR MISS RIVER VALLEY REGION. DEEP MOISTURE...WITH PWATS NEARING 2 INCHES...WILL BE COMMON SAT THRU MON. SEVERAL SHTWV DISTURBANCES FLYING WITHIN THE SW FLOW ALONG WITH A DEEPENING LOW PRES CENTER OVER THE ERN DAKOTAS INTO WRN MN WITH THE WFO MPX CWFA IN THE WARM SECTOR SPELLS ADDITIONAL ROUNDS OF HEAVY RAIN AND TSTMS THRU THE WEEKEND. INSTABILITY REMAINS HIGH...WITH MLCAPES IN THE 3000-4000 J/KG RANGE...AND THE SAT PERIOD MAY START OUT WITH AN MCS AND/OR CLUSTER OF TSTMS EXITING THE AREA. WIDESCALE LIFT...STEEP LAPSE RATES AND ENHANCED BULK SHEAR WILL AGAIN PROMOTE THE RE- DEVELOPMENT OF TSTMS BY SAT EVE INTO SAT NIGHT...SOME OF WHICH MAY BE SEVERE WITH LARGE HAIL AND DMGG WINDS. A SIMILAR SITUATION WILL THEN PRESENT ITSELF FOR SUN AS THE UPR TROUGH SHIFTS SLIGHTLY E... HELPING DROP H5 HEIGHTS WHILE ENHANCING MID- AND UPR-LEVEL JETTING. CONVECTIVE ACTIVITY MAY WELL AGAIN CONTINUE FROM LATE SAT NIGHT INTO EARLY SUN MORNING...THEN AGAIN BECOME REINVIGORATED FROM MIDDAY HEATING TO SPARK LATE AFTN AND EVE TSTMS FOR SUN. THE DEEP MOISTURE REMAINING IN PLACE WILL AGAIN PROMOTE HEAVY RAIN AS WELL. THIS LONGWAVE TROUGH WILL LIFT OUT GOING INTO MON...BUT WILL GRADUALLY BE REPLACED BY ANOTHER UPPER LEVEL LOW CURRENTLY NEAR ALASKA THAT WILL DROP ACROSS WRN CANADA INTO THE NRN PLAINS WED THROUGH THU. THIS WILL THEN CREATE THE WRN RIDGE/ERN TROF PATTERN THAT WILL SHOVE A LOW PRES CENTER NEWD ACRS MN INTO THE GRT LAKES WED WITH THE UPR LOW TRAILING IT THRU THU. MID TO HIGH CHC RANGE POPS WILL REMAIN IN THE FCST THRU THE MIDDLE OF NEXT WEEK...WITH AGAIN CHCS FOR STRONG TSTMS ALONG WITH HVY RAIN. VERY LITTLE CHANGE IN AIRMASS IS EXPECTED THRU THE MIDDLE OF NEXT WEEK... WHICH MEANS HIGHS IN THE MID-UPR 80S AND LOWS IN THE MID 60S TO LWR 70S. IN ADDITION...DEWPOINTS WILL REMAIN IN THE 60S TO LWR 70S WHICH MEANS HEAT INDEX VALUES UP INTO THE MID 90S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 127 PM CDT FRI JUN 21 2013 WINDS STARTING TO SETTLE BACK TO THE EAST IN THE WAKE OF LAST NIGHTS SYSTEM. GOING OF THE H7 TEMP MESOANALYSIS...BELIEVE THE MPX AREA IS CAPPED FOR ANY CONVECTION THIS AFTERNOON...INSTEAD WE ARE WAITING ON THE GROWING AREA OF STORMS OVER SODAK FOR MORE TSRA ACTIVITY. RELIED HEAVILY ON THE HRRR TO TIME THESE SODAK STORMS ACROSS THE TERMINALS TONIGHT. AT THE MOMENT...IS LIKELY THEY MAY SKIRT JUST TO THE SOUTH OF AXN/STC...SO HAVE NO TEMP GROUPS THERE. AFTER THAT...HRRR IS INDICATING STORMS WILL CONTINUE TO FIRE ON THE NOSE OF THE LLJ OVER SE SODAK AND CONTINUE TO TRACK EAST...SO THERE IS THE POTENTIAL FOR RWF IN PARTICULAR TO SEE AT LEAST A COUPLE OF ROUNDS OF STORMS TONIGHT. MVFR CIGS WILL LINGER ACROSS WRN WI FOR THE NEXT COUPLE OF HOURS. SHOULD THEN SEE VFR CONDS UNTIL NEXT ROUND OF STORMS MOVE IN...WITH CIGS EXPECTED TO BEHAVE VERY SIMILAR TO HOW THEY DID OVERNIGHT INTO THIS PAST MORNING. KMSP...HRRR HAS BEEN CONSISTENT WITH TRACKING ANOTHER STRONG TO SEVERE LINE OF STORMS ACROSS MSP THIS EVENING...THOUGH A BIT EARLIER TONIGHT...WITH THE 3Z-6Z PERIOD LOOKING LIKE THE MOST LIKELY WINDOW FOR ANOTHER ROUND OF STORMS. HRRR IS SHOWING STORMS CONTINUING TO FIRE THROUGH THE NIGHT WEST OF THIS FIRST LINE. CURRENT THINKING IS THAT ADDITIONAL CONVECTION WILL BE MAINLY SOUTH OF THE FIELD...BUT IF THIS ADDITIONAL ACTIVITY DOES GO FARTHER NORTH THAN CURRENTLY INDICATED...THEN THERE COULD BE SIGNIFICANT IMPACTS DUE TO CONVECTION FOR MUCH OF THE NIGHT INTO SAT MORNING. BY SATURDAY AFTERNOON...MOIST UNSTABLE AIRMASS WILL LEAD TO THE POTENTIAL FOR MORE DIURNALLY DRIVEN CONVECTION TO END THE TAF. /OUTLOOK FOR KMSP/ SUN...TSRA LIKELY. VFR OUTSIDE OF TSRA. WINDS SSW 10-15 KTS. MON...CHC TSRA. VFR OUTSIDE OF TSRA. WINDS S 5-10 KTS. TUE...CHC TSRA. VFR OUTSIDE OF TSRA. WINDS SSE 10-15 KTS. && .HYDROLOGY... ISSUED AT 422 AM CDT FRI JUN 21 2013 SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED THROUGH THIS WEEKEND ARE LIKELY TO PRODUCE HIGH RAINFALL TOTALS ACROSS THE AREA...POTENTIALLY LEADING TO LOCALIZED FLOODING PROBLEMS. THE PRIMARY TIME OF CONCERN WILL BE THROUGH LATE THIS MORNING...AND AGAIN OVERNIGHT TONIGHT. THE OVERALL SYNOPTIC PATTERN IS SUCH THAT A STRONG LOW PRESSURE AREA ACROSS THE WESTERN CONUS...AND A HIGH PRESSURE AREA ACROSS THE EASTERN CONUS...ARE EXPECTED TO MOVE VERY LITTLE OVER THE NEXT FEW DAYS...WHICH MEANS WE WILL REMAIN IN A FAVORABLE ENVIRONMENT FOR THUNDERSTORMS DEVELOPMENT EACH AFTERNOON/NIGHT. THIS SETUP HAS ALREADY BEGUN TO OPEN THE DOOR FOR GULF MOISTURE TO BEGIN STREAMING INTO THE UPPER MIDWEST. SURFACE DEW POINT TEMPERATURES WILL REACH 70 DEGREES WITH PRECIPITABLE WATER VALUES BETWEEN 1.5 AND 2 INCHES. IN ADDITION...STRONG MOISTURE TRANSPORT FROM THE GULF WILL AID IN DEVELOPING HEAVY RAINFALL RATES. THIS MOIST AIR MASS WILL REMAIN OVER THE AREA FOR THE NEXT SEVERAL DAYS...AND GIVEN THE ABUNDANT MOISTURE AVAILABLE...EXTREMELY HEAVY RAINFALL RATES OF UP TO 3 INCHES PER HOUR WILL BE POSSIBLE IN STRONG THUNDERSTORMS THAT TRAVERSE THE AREA THROUGH THE WEEKEND. ANTECEDENT SOIL CONDITIONS ARE GENERALLY MOIST GIVEN THE WET SPRING...WHICH ENHANCES THE POTENTIAL FOR FLASH FLOODING. THROUGH NEXT WEEK...RAINFALL TOTALS COULD RANGE FROM 3 TO 5 INCHES...WHICH WILL ALSO LEAD TO RISES ON MAIN STEM RIVERS NEXT WEEK. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ UPDATE...MPG SHORT TERM...CLF LONG TERM...JPC AVIATION...MPG HYDROLOGY...JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1143 AM CDT FRI JUN 21 2013 .UPDATE... ISSUED AT 1142 AM CDT FRI JUN 21 2013 LARGE MCS FROM LAST NIGHT HAS NOW PUSHED INTO ERN WI AND NRN IL. IN ITS WAKE...STRONG OUTFLOW BOUNDARY HAS DEVELOPED IN IOWA FROM ROUGHLY THE QUAD CITIES BACK TO AROUND THE SIOUX CITY AREA. BASED ON WIND FIELD...MAIN WARM FRONTAL BOUNDARY STRETCHES FROM SOUTH OF CANBY SOUTHEAST TOWARD ST. JAMES AND ALBERT LEA. WITH THE MORNING UPDATE...DID CUT BACK SIGNIFICANTLY ON POPS THROUGH 00Z AS VERY FEW HI-RES CAMS SHOW ANY CONVECTION FORMING DURING THE DAYLIGHT HOURS IN MN/WI. COUPLE OF REASONS FOR THIS APPEARS TO BE THE FACT THAT THE ATMO IS PRETTY WORKED OVER AFTER LAST NIGHT /AS SEEN WITH 12Z KMPX SOUNDING AND OUTFLOW BOUNDARY DOWN IN IA/...ALONG WITH THE PRESENCE OF A CAPPING EML MOVING IN FROM NEB...WITH THE 16Z SPC MESO ANALYSIS SHOWING THE +12C ISOTHERM AT H7 CLEAR UP TO THE US-212 CORRIDOR IN MN. FOR THIS REASON...STILL FEEL THAT THE MPX AREA WILL REMAIN HIGH AND DRY THROUGH TODAY. HOWEVER...YOU CAN NOT COMPLETELY RULE OUT SOMETHING FORMING ALONG WITH WARM FRONT LATER THIS AFTERNOON /AS MENTIONED IN THE SPC DAY1 OUTLOOK/. IF SOMETHING WERE TO DEVELOP...THEN THE RISK FOR LARGE HAIL...DAMAGING WINDS...AND POSSIBLY EVEN A TORNADO WILL EXIST. ONCE AGAIN HOWEVER...MORE ROBUST CONVECTION IN THE FORM OF AN MCS IS EXPECTED TONIGHT. BASED ON THE HRRR AND 21.12 MPXWRF...THIS MCS LOOKS LIKE IT WILL EVOLVE FROM THE LARGE THUNDERSTORM CURRENTLY OVER THE BADLANDS OF SODAK. TO GO ALONG WITH THESE...THE 9Z MEMBERS OF THE HOPWRF SHOW A SIMILAR TREND OCCURRING WITH CONVECTION THIS AFTERNOON/EVENING AS WELL. LIKE LAST NIGHT...0-1KM SHEAR WILL BE INCREASING AS NOCTURNAL LLJ INCREASES IN STRENGTH...SO ANOTHER SEVERE BOW ECHO LOOKS LIKELY...JUST A MATTER OF HOW FAR NORTH IT TRACKS. GIVEN THE EXPECTATION OF ANOTHER MCS...MAY HAVE TO HOIST ANOTHER FLASH FLOOD WATCH FOR TONIGHT ONCE A BETTER FEEL FOR WHERE THIS NEXT MCS WILL TRACK CAN BE DETERMINED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 422 AM CDT FRI JUN 21 2013 WE WILL KEEP THIS DISCUSSION SHORT AND SWEET. IT HAS BEEN A LONG NIGHT. A MATURE MCS IS NOW IN THE EASTERN THIRD OF THE FORECAST AREA AFTER TRACKING ACROSS THE ENTIRE STATE OF MN AND INTO WI THROUGH THE OVERNIGHT HOURS. THERE IS LITTLE CHANGE IN THE LARGE- SCALE FLOW REGIME ACROSS MN/WI OVER THE NEXT 24-36 HOURS. SOUTHWESTERLY FLOW ALOFT WITH THE RIDGE OVERHEAD. 925MB-850MB MOISTURE TRANSPORT EXPLODED LAST NIGHT AND WE SAW THE RESULT WITH WIDESPREAD SEVERE WEATHER. THERE REALLY IS NOT MUCH DIFFERENCE WITH THE UPCOMING SHORT TERM PATTERN. THERE IS DECENT CONSENSUS AMONGST THE NAM/GFS/ECMWF WITH THE DEVELOPMENT OF ANOTHER CONVECTIVE COMPLEX LATE IN THE AFTERNOON AND EVENING NEAR THE MN/SD BORDER AND MARCHING THAT EAST WITH TIME. MODERATE TO HIGH INSTABILITY VALUES WILL NOT BE A PROBLEM AS WE RELOAD TODAY AND THE DEEP LAYER SHEAR WILL BE STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION. SOME OF THE HIGHER RESOLUTION /CONVECTIVE ALLOWING MODELS/ WE LOOK AT FOCUS MORE OF THE CONVECTION TO THE SOUTH IN NE/IA. THIS WOULD BE FARTHER SOUTH THAN THE NAM/ECMWF/GFS/. ADMITTEDLY SO...THESE THREE RUNS DO HAVE SOME DIFFERENCES. THE GFS AND ECMWF ARE SIMILAR IN THE LOCATION OF CONVECTIVE INITIATION. THE NAM IS FARTHER SOUTH BUT THE GFS AND ECMWF ARE SIMILAR. HOWEVER...THE GFS IS FASTER. WE WILL HAVE TO PAY ATTENTION TO THE OUTFLOW FROM THIS MORNING`S CONVECTION...THAT COULD BE A TRIGGER TODAY. HOWEVER...THERE SHOULD BE AN EAST-WEST BOUNDARY...SO FLASH FLOODING WILL AGAIN BE A MAJOR THREAT ALONG WITH THE HAIL AND WIND...ESPECIALLY GIVEN THE SATURATED SOILS AFTER THIS MORNING. SO IN SUMMARY...GET READY TO DO THIS ALL AGAIN TONIGHT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 422 AM CDT FRI JUN 21 2013 POTENT RIDGE OVER THE WRN CONUS WITH LONGWAVE TROUGHING OVER THE WRN CONUS WILL PROMOTE PROGRESSIVE SWLY FLOW OVER THE UPR MISS RIVER VALLEY REGION. DEEP MOISTURE...WITH PWATS NEARING 2 INCHES...WILL BE COMMON SAT THRU MON. SEVERAL SHTWV DISTURBANCES FLYING WITHIN THE SW FLOW ALONG WITH A DEEPENING LOW PRES CENTER OVER THE ERN DAKOTAS INTO WRN MN WITH THE WFO MPX CWFA IN THE WARM SECTOR SPELLS ADDITIONAL ROUNDS OF HEAVY RAIN AND TSTMS THRU THE WEEKEND. INSTABILITY REMAINS HIGH...WITH MLCAPES IN THE 3000-4000 J/KG RANGE...AND THE SAT PERIOD MAY START OUT WITH AN MCS AND/OR CLUSTER OF TSTMS EXITING THE AREA. WIDESCALE LIFT...STEEP LAPSE RATES AND ENHANCED BULK SHEAR WILL AGAIN PROMOTE THE RE- DEVELOPMENT OF TSTMS BY SAT EVE INTO SAT NIGHT...SOME OF WHICH MAY BE SEVERE WITH LARGE HAIL AND DMGG WINDS. A SIMILAR SITUATION WILL THEN PRESENT ITSELF FOR SUN AS THE UPR TROUGH SHIFTS SLIGHTLY E... HELPING DROP H5 HEIGHTS WHILE ENHANCING MID- AND UPR-LEVEL JETTING. CONVECTIVE ACTIVITY MAY WELL AGAIN CONTINUE FROM LATE SAT NIGHT INTO EARLY SUN MORNING...THEN AGAIN BECOME REINVIGORATED FROM MIDDAY HEATING TO SPARK LATE AFTN AND EVE TSTMS FOR SUN. THE DEEP MOISTURE REMAINING IN PLACE WILL AGAIN PROMOTE HEAVY RAIN AS WELL. THIS LONGWAVE TROUGH WILL LIFT OUT GOING INTO MON...BUT WILL GRADUALLY BE REPLACED BY ANOTHER UPPER LEVEL LOW CURRENTLY NEAR ALASKA THAT WILL DROP ACROSS WRN CANADA INTO THE NRN PLAINS WED THROUGH THU. THIS WILL THEN CREATE THE WRN RIDGE/ERN TROF PATTERN THAT WILL SHOVE A LOW PRES CENTER NEWD ACRS MN INTO THE GRT LAKES WED WITH THE UPR LOW TRAILING IT THRU THU. MID TO HIGH CHC RANGE POPS WILL REMAIN IN THE FCST THRU THE MIDDLE OF NEXT WEEK...WITH AGAIN CHCS FOR STRONG TSTMS ALONG WITH HVY RAIN. VERY LITTLE CHANGE IN AIRMASS IS EXPECTED THRU THE MIDDLE OF NEXT WEEK... WHICH MEANS HIGHS IN THE MID-UPR 80S AND LOWS IN THE MID 60S TO LWR 70S. IN ADDITION...DEWPOINTS WILL REMAIN IN THE 60S TO LWR 70S WHICH MEANS HEAT INDEX VALUES UP INTO THE MID 90S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 727 AM CDT FRI JUN 21 2013 BRIEF REPRIVE FROM THE THUNDERSTORMS LATE THIS MORNING AND AFTERNOON...BUT INSTABILITY WILL BUILD THIS AFTERNOON AND SET THE STAGE FOR ANOTHER ROUND OF THUNDERSTORMS THIS EVENING. STRONG WIND AND HEAVY RAIN WILL BE A THREAT AT ALL TAF SITES FROM ABOUT 23Z UNTIL 09-10Z. KMSP... VFR EXPECTED TODAY...BUT THUNDERSTORM CHANCES INCREASE LATE THIS AFTERNOON. THE EVENT TODAY...SHOULD BE A LITTLE EARLIER WHEN COMPARED TO THE TIMING OF LAST NIGHT`S STORMS. /OUTLOOK FOR KMSP/ SAT...TSRA LIKELY. VFR OUTSIDE OF TSRA. WINDS SE 10 KTS SUN...TSRA LIKELY. VFR OUTSIDE OF TSRA. WINDS SSW 10-15 KTS. MON...CHC TSRA. VFR OUTSIDE OF TSRA. WINDS S 5-10KTS. && .HYDROLOGY... ISSUED AT 422 AM CDT FRI JUN 21 2013 SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED THROUGH THIS WEEKEND ARE LIKELY TO PRODUCE HIGH RAINFALL TOTALS ACROSS THE AREA...POTENTIALLY LEADING TO LOCALIZED FLOODING PROBLEMS. THE PRIMARY TIME OF CONCERN WILL BE THROUGH LATE THIS MORNING...AND AGAIN OVERNIGHT TONIGHT. THE OVERALL SYNOPTIC PATTERN IS SUCH THAT A STRONG LOW PRESSURE AREA ACROSS THE WESTERN CONUS...AND A HIGH PRESSURE AREA ACROSS THE EASTERN CONUS...ARE EXPECTED TO MOVE VERY LITTLE OVER THE NEXT FEW DAYS...WHICH MEANS WE WILL REMAIN IN A FAVORABLE ENVIRONMENT FOR THUNDERSTORMS DEVELOPMENT EACH AFTERNOON/NIGHT. THIS SETUP HAS ALREADY BEGUN TO OPEN THE DOOR FOR GULF MOISTURE TO BEGIN STREAMING INTO THE UPPER MIDWEST. SURFACE DEW POINT TEMPERATURES WILL REACH 70 DEGREES WITH PRECIPITABLE WATER VALUES BETWEEN 1.5 AND 2 INCHES. IN ADDITION...STRONG MOISTURE TRANSPORT FROM THE GULF WILL AID IN DEVELOPING HEAVY RAINFALL RATES. THIS MOIST AIR MASS WILL REMAIN OVER THE AREA FOR THE NEXT SEVERAL DAYS...AND GIVEN THE ABUNDANT MOISTURE AVAILABLE...EXTREMELY HEAVY RAINFALL RATES OF UP TO 3 INCHES PER HOUR WILL BE POSSIBLE IN STRONG THUNDERSTORMS THAT TRAVERSE THE AREA THROUGH THE WEEKEND. ANTECEDENT SOIL CONDITIONS ARE GENERALLY MOIST GIVEN THE WET SPRING...WHICH ENHANCES THE POTENTIAL FOR FLASH FLOODING. THROUGH NEXT WEEK...RAINFALL TOTALS COULD RANGE FROM 3 TO 5 INCHES...WHICH WILL ALSO LEAD TO RISES ON MAIN STEM RIVERS NEXT WEEK. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ UPDATE...MPG SHORT TERM...CLF LONG TERM...JPC AVIATION...CLF HYDROLOGY...JPC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
602 PM CDT FRI JUN 21 2013 .SHORT TERM...(THROUGH LATE TONIGHT) ISSUED AT 323 PM CDT FRI JUN 21 2013 THE MAIN SHORT-TERM CONCERN IS THE MCS GENERATED OUTFLOW BOUNDARY CURRENTLY DROPPING S/SEWD THROUGH CENTRAL IL. WHILE THE MCS ITSELF IS MOVING SEWD...THE RUC 0-3 KM AND 0-6 KM SHEAR VECTORS SUGGEST THAT AS LONG AS THIS BOUNDARY MAINTAINS ITS IDENTITY IT SHOULD CONTINUE TO DROP S/SEWD AND AT LEAST IMPACT AREAS EAST OF THE MS RIVER LATE THIS AFTERNOON INTO EARLY THIS EVENING. THE AIR MASS AHEAD OF THIS BOUNDARY IS WEAKLY CAPPED WITH SBCAPE INCREASING FROM 2000 J/KG IN CENTRAL IL TO NEAR 4000 J/KG ALONG THE RIVER. THIS COMBINATION OF INSTABILITY/CAPPING AND CONVERGENCE WITH THE BOUNDARY SUPPORTS A GREATER CHANCE OF MORE ORGANIZED CONVECTION ACROSS SOUTH CENTRAL IL WHERE SCATTERED THUNDERSTORMS ARE POSSIBLE. ELSEWHERE THROUGH SUNSET ANY THREAT OF SHOWERS/THUNDERSTORMS WILL BE ISOLATED PULSE TYPE ACTIVITY ASSOCIATED WITH DIURNAL HEATING. I THINK THERE WILL THEN BE A LULL FROM SAY AROUND 02-03Z TIL 08Z OR SO...THEN ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS...PRIMARILY ACROSS ERN MO INTO SW/SC IL... ASSOCIATED WITH LOW-MID LEVEL WAA VIA THE SWLY LLJ AND STEEP MID LEVEL LAPSE RATES. OVERNIGHT LOWS WILL BE QUITE MILD AND ABOVE SEASONABLE NORMS. GLASS .LONG TERM...(SATURDAY THROUGH NEXT FRIDAY) ISSUED AT 323 PM CDT FRI JUN 21 2013 (SATURDAY THROUGH MONDAY) BROKEN RECORD FOR WEATHER PATTERN AS WE REMAIN IN WARM SECTOR ON SATURDAY WITH SOME WEAK INSTABILITY AND PLENTY OF MOISTURE. SO ANY OLD OUTFLOW BOUNDARY...ETC COULD TRIGGER ISOLATED THUNDERSTORM DEVELOPMENT...SO KEPT SLIGHT CHANCE POPS FOR SATURDAY AFTERNOON. OTHERWISE...HIGHS WILL BE IN THE UPPER 80S TO LOW 90S...POSSIBLY IN THE MID 90S IN THE STL METRO AREA. LOWS SATURDAY NIGHT WILL BE IN THE LOW 70S. UPPER RIDGE BUILDS IN A BIT STRONGER ON SUNDAY...SO THUNDERSTORM CHANCES DIMINISH. BUT HOT AND HUMID CONDITIONS TO PERSIST WITH HIGHS IN THE UPPER 80S TO LOW 90S. ON SUNDAY NIGHT AND MONDAY...UPPER RIDGE BEGINS TO WEAKEN AGAIN AS NEXT WEATHER SYSTEM APPROACHES THE REGION. MCS EXPECTED TO DEVELOP ALONG BOUNDARY OVER IOWA...WITH SOUTHERN FRINGES SLIDING THROUGH NORTHERN MO/WEST CENTRAL IL ON MONDAY. LOWS SUNDAY NIGHT WILL BE IN THE LOW TO MID 70S WITH HIGHS ON MONDAY IN THE UPPER 80S TO LOW 90S. (MONDAY NIGHT THROUGH FRIDAY) EXTENDED MODELS CONTINUE TO SLOW DOWN PASSAGE OF THIS COLD FRONT...SO HOT AND HUMID CONDITIONS TO PERSIST THROUGH THURSDAY WITH HIGHS EACH DAY IN THE UPPER 80S TO MID 90S. BY WEDNESDAY NIGHT...COLD FRONT MOVES CLOSER TO AREA WITH CHANCES OF SHOWERS AND THUNDERSTORMS FOR PORTIONS OF THE AREA WEDNESDAY NIGHT AND THURSDAY. CONFIDENCE ON TIMING OF FRONTAL PASSAGE LOW...SO FOR NOW HAVE SILENT SLIGHT CHANCE POPS IN FOR AREA THURSDAY NIGHT AND PORTIONS OF THE AREA FRIDAY UNTIL FRONT FINALLY MOVES THROUGH. BY FRIDAY HIGHS WILL BE IN THE MID TO UPPER 80S. BYRD && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 556 PM CDT FRI JUN 21 2013 THE STRONG MIDLEVEL RIDGE WILL CONTINUE TO CONTROL THE WEATHER PATTERN THROUGH SATURDAY NIGHT. INSTABILITY WILL BE PLENTIFUL TOMORROW AFTERNOON...BUT COVERAGE SHOULD ONCE AGAIN REMAIN ISOLATED SINCE ANY LARGE-SCALE FORCING MECHANISM FOR ASCENT SHOULD BE LACKING. THEREFORE...HAVE CONTINUED TO LEAVE ANY MENTION OF TS 0R SHRA OUT OF TAFS FOR NOW. DIURNAL CU SHOULD DEVELOP WITH BASES AROUND 5000 FEET TOMORROW AROUND MIDDAY WITH WINDS THROUGHOUT THE VALID TAF PERIOD REMAINING OUT OF THE SOUTH. SPECIFICS FOR KSTL... THE STRONG MIDLEVEL RIDGE WILL CONTINUE TO CONTROL THE WEATHER PATTERN THROUGH SATURDAY NIGHT FOR LAMBERT FIELD. INSTABILITY WILL BE PLENTIFUL TOMORROW AFTERNOON...BUT COVERAGE OF ANY STORMS WHICH WOULD DEVELOP SHOULD ONCE AGAIN REMAIN ISOLATED SINCE ANY LARGE- SCALE FORCING MECHANISM FOR ASCENT SHOULD BE LACKING. THEREFORE...HAVE CONTINUED TO LEAVE ANY MENTION OF TS 0R SHRA OUT OF TAF FOR NOW. DIURNAL CU SHOULD DEVELOP WITH BASES AROUND 5000 FEET TOMORROW AROUND MIDDAY WITH WINDS THROUGHOUT THE VALID TAF PERIOD REMAINING OUT OF THE SOUTH. GOSSELIN && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
325 PM CDT FRI JUN 21 2013 .SHORT TERM...(THROUGH LATE TONIGHT) ISSUED AT 323 PM CDT FRI JUN 21 2013 THE MAIN SHORT-TERM CONCERN IS THE MCS GENERATED OUTFLOW BOUNDARY CURRENTLY DROPPING S/SEWD THROUGH CENTRAL IL. WHILE THE MCS ITSELF IS MOVING SEWD...THE RUC 0-3 KM AND 0-6 KM SHEAR VECTORS SUGGEST THAT AS LONG AS THIS BOUNDARY MAINTAINS ITS IDENTITY IT SHOULD CONTINUE TO DROP S/SEWD AND AT LEAST IMPACT AREAS EAST OF THE MS RIVER LATE THIS AFTERNOON INTO EARLY THIS EVENING. THE AIR MASS AHEAD OF THIS BOUNDARY IS WEAKLY CAPPED WITH SBCAPE INCREASING FROM 2000 J/KG IN CENTRAL IL TO NEAR 4000 J/KG ALONG THE RIVER. THIS COMBINATION OF INSTABILITY/CAPPING AND CONVERGENCE WITH THE BOUNDARY SUPPORTS A GREATER CHANCE OF MORE ORGANIZED CONVECTION ACROSS SOUTH CENTRAL IL WHERE SCATTERED THUNDERSTORMS ARE POSSIBLE. ELSEWHERE THROUGH SUNSET ANY THREAT OF SHOWERS/THUNDERSTORMS WILL BE ISOLATED PULSE TYPE ACTIVITY ASSOCIATED WITH DIURNAL HEATING. I THINK THERE WILL THEN BE A LULL FROM SAY AROUND 02-03Z TIL 08Z OR SO...THEN ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS...PRIMARILY ACROSS ERN MO INTO SW/SC IL... ASSOCIATED WITH LOW-MID LEVEL WAA VIA THE SWLY LLJ AND STEEP MID LEVEL LAPSE RATES. OVERNIGHT LOWS WILL BE QUITE MILD AND ABOVE SEASONABLE NORMS. GLASS .LONG TERM...(SATURDAY THROUGH NEXT FRIDAY) ISSUED AT 323 PM CDT FRI JUN 21 2013 (SATURDAY THROUGH MONDAY) BROKEN RECORD FOR WEATHER PATTERN AS WE REMAIN IN WARM SECTOR ON SATURDAY WITH SOME WEAK INSTABILITY AND PLENTY OF MOISTURE. SO ANY OLD OUTFLOW BOUNDARY...ETC COULD TRIGGER ISOLATED THUNDERSTORM DEVELOPMENT...SO KEPT SLIGHT CHANCE POPS FOR SATURDAY AFTERNOON. OTHERWISE...HIGHS WILL BE IN THE UPPER 80S TO LOW 90S...POSSIBLY IN THE MID 90S IN THE STL METRO AREA. LOWS SATURDAY NIGHT WILL BE IN THE LOW 70S. UPPER RIDGE BUILDS IN A BIT STRONGER ON SUNDAY...SO THUNDERSTORM CHANCES DIMINISH. BUT HOT AND HUMID CONDITIONS TO PERSIST WITH HIGHS IN THE UPPER 80S TO LOW 90S. ON SUNDAY NIGHT AND MONDAY...UPPER RIDGE BEGINS TO WEAKEN AGAIN AS NEXT WEATHER SYSTEM APPROACHES THE REGION. MCS EXPECTED TO DEVELOP ALONG BOUNDARY OVER IOWA...WITH SOUTHERN FRINGES SLIDING THROUGH NORTHERN MO/WEST CENTRAL IL ON MONDAY. LOWS SUNDAY NIGHT WILL BE IN THE LOW TO MID 70S WITH HIGHS ON MONDAY IN THE UPPER 80S TO LOW 90S. (MONDAY NIGHT THROUGH FRIDAY) EXTENDED MODELS CONTINUE TO SLOW DOWN PASSAGE OF THIS COLD FRONT...SO HOT AND HUMID CONDITIONS TO PERSIST THROUGH THURSDAY WITH HIGHS EACH DAY IN THE UPPER 80S TO MID 90S. BY WEDNESDAY NIGHT...COLD FRONT MOVES CLOSER TO AREA WITH CHANCES OF SHOWERS AND THUNDERSTORMS FOR PORTIONS OF THE AREA WEDNESDAY NIGHT AND THURSDAY. CONFIDENCE ON TIMING OF FRONTAL PASSAGE LOW...SO FOR NOW HAVE SILENT SLIGHT CHANCE POPS IN FOR AREA THURSDAY NIGHT AND PORTIONS OF THE AREA FRIDAY UNTIL FRONT FINALLY MOVES THROUGH. BY FRIDAY HIGHS WILL BE IN THE MID TO UPPER 80S. BYRD && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1216 PM CDT FRI JUN 21 2013 VFR CONDITIONS ARE EXPECTED TO DOMINATE THROUGH THE PERIOD WITH DIURNAL CU AND SCATTERED MID CLOUDS AT NIGHT. A TYPICAL SUMMERTIME WARM MOIST AND UNSTABLE AIR MASS IS PRESENT ACROSS THE AREA WHICH MEANS AN ISOLATED THUNDERSTORM COULD DEVELOP JUST ABOUT ANYWHERE THIS AFTERNOON UNTIL SUNSET. BEST INDICATIONS AT THIS TIME ARE THAT NE MISSOURI INTO WEST CENTRAL IL MAY HAVE SLIGHTLY BETTER PROBABILITIES. THE THREAT HOWEVER AT ANY TAF SITE IS TOO LOW TO MENTION AT THIS TIME. SPECIFICS FOR KSTL... VFR CONDITIONS ARE EXPECTED TO DOMINATE THROUGH THE PERIOD WITH DIURNAL CU AND SCATTERED MID CLOUDS AT NIGHT. A TYPICAL SUMMERTIME WARM MOIST AND UNSTABLE AIR MASS IS PRESENT ACROSS THE AREA WHICH MEANS AN ISOLATED THUNDERSTORM COULD DEVELOP JUST ABOUT ANYWHERE...THE THREAT HOWEVER IS TOO LOW TO MENTION AT THIS TIME. GLASS && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
656 PM EDT FRI JUN 21 2013 .SYNOPSIS... HIGH PRESSURE ANCHORED OFF THE ATLANTIC COAST WILL KEEP THE NORTH COUNTRY DRY TODAY WITH PARTLY TO MOSTLY SUNNY SKIES THIS AFTERNOON AND TEMPERATURES IN THE MID 70S TO LOWER 80S. A WARM FRONT WILL MOVE SLOWLY THROUGH THE AREA ON SATURDAY WITH SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM WITH TEMPERATURES AGAIN RANGING THROUGH THE 70S NORTHEAST TO THE LOWER 80S SOUTHWEST. EVEN WARMER AND MORE HUMID CONDITIONS ARE EXPECTED SUNDAY INTO NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 323 PM EDT FRIDAY...TONIGHT BEGINS WITH CLEAR TO PARTLY CLOUDY SKIES THIS EVENING...BUT CLOUD COVER WILL INCREASE AFTER MIDNIGHT AS DEBRIS CLOUDS FROM A MESOSCALE CONVECTIVE COMPLEX AND IT`S ASSOCIATED VORTICITY OVER THE UPPER GREAT LAKES RIDES EAST SOUTHEASTWARD ALONG THE A DEVELOPING WARM FRONTAL BOUNDARY OVER OUR AREA. TEMPS WILL RUN RIGHT AROUND SEASONAL NORMALS IN THE 50S TO NEAR 60 IN THE VALLEYS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 323 PM EDT FRIDAY...SATURDAY...MODERATE CONFIDENCE CONTINUES THAT WE`LL SEE SOME SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM AS THE DECAYING MCV AND SHORT WAVE TROF MOVES ACROSS THE REGION DURING MIDDAY INTO THE EARLY EVENING. MODEL GUIDANCE HAS BEEN STRUGGLING WITH THE PLACEMENT OF THIS FEATURE WITH THE GFS MORE WIDESPREAD AND FURTHER SOUTH AND THE NAM FURTHER NORTH. HAVE PLAYED IT MORE TOWARD THE GFS/MAV SOLUTION AS RAP ANALYSIS SHOWS SIGNIFICANT MCV HAS FORMED. SO HIGHER POPS THAN WHAT THE NAM MOS SUGGESTS AND SLIGHT COOLER TEMPERATURES. HAVE STAYED MAINLY NEAR 80 WITH COOLER TEMPS NORTHEAST AND WARMER SOUTHWEST. WHERE CLOUDS/SHOWERS HANG ON IT COULD BE 5 DEGREES COOLER AND WHERE THEY DISSIPATE 5 DEGREES WARMER. IN THE ABSENCE OF ANY LARGE SCALE FORCING...ANY CONVECTIVE ACTIVITY WILL DISSIPATE GOING INTO THE EVENING AND OVERNIGHT HOURS SAT NIGHT WITH LOWS MAINLY IN THE 60S. ON SUNDAY...MORE TYPICAL ISOLATED TO SCATTERED AIRMASS TYPE PULSE SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SUNDAY MAINLY IN THE MID TO LATE AFTERNOON/EVENING WITH ACTIVITY SETTLING DOWN OVERNIGHT SUNDAY NIGHT. CAPE VALUES NOT ALL THAT IMPRESSIVE (BELOW 100 J/KG) WITH GFS SUGGESTING A CAPPING SUBSIDENCE INVERSION MAY BE IN PLACE SO KEPT A MINIMAL CHANCE POPS IN THE FOREAST. IT SHOULD BE CONSIDERABLY WARMER AND MORE HUMID AIR PUSHES IN AS THE WARM FRONT LIFTS NORTHEAST SUNDAY WITH HIGHS IN THE 80S. SUNDAY NIGHT SHOULD BE VERY MILD WITH READINGS IN THE 60S PERHAPS NEAR 70 AT BTV WITH WARM AND HUMID AIR FIRMLY ENTRENCHED. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 350 PM EDT FRIDAY...LARGE SCALE PATTERN WL CONTINUE TO SUPPORT MID/UPPER LVL RIDGE ACRS THE SE CONUS WITH FAST WESTERLY FLW ALOFT NEAR THE INTERNATIONAL BORDER THRU EARLY NEXT WEEK. BY MID TO LATE NEXT WEEK ALL GUIDANCE SUGGESTS A PATTERN CHANGE WITH DEVELOPMENT OF FULL LATITUDE TROF ACRS THE GREAT LAKES/EASTERN CONUS AND LARGE RIDGE OVER THE INTER-MOUNTAIN WEST. THIS WL RESULT IN MUCH ABOVE NORMAL TEMPS FOR MONDAY/TUESDAY WITH CHCS FOR AFTN/EVENING SHOWERS/STORMS...WITH A TREND TWD COOLER AND WETTER CONDITIONS BY LATE NEXT WEEK...AS TROF DEVELOPS AND SFC LOW PRES IMPACTS OUR FA. PROGGED 85H TEMPS NEAR 16C AND 925MB TEMPS BTWN 20-22C ON MONDAY/TUESDAY...SUPPORTS HIGHS WELL INTO THE 80S WITH EVEN A FEW LOWER 90S POSSIBLE IN THE WARMER VALLEY LOCATIONS. IN ADDITION...PROGGED SFC DWPTS ARE EXPECTED TO BE IN THE MID/UPPER 60S...CREATING VERY MUGGY CONDITIONS...ESPECIALLY ON MONDAY. THIS HEAT/HUMIDITY WL HELP TO PRODUCE SOME MODEST CAPE VALUES...COMBINED WITH EMBEDDED 5H VORTS WL HELP IN THE DEVELOPMENT OF AFTN/EVENING SHOWERS/STORMS. WL CONT TO MENTION CHC POPS ATTM...WITH MAIN FOCUS DURING THE PEAK HEATING HRS. ANY STORMS THAT DUE DEVELOP WL HAVE THE POTENTIAL TO PRODUCE LOCALIZED HEAVY DOWNPOURS WITH PW VALUES BTWN 1.50 AND 1.75". BETTER DYNAMICS AND MOISTURE ARRIVES BY LATE NEXT WK...AS MID/UPPER LVL TROF DEVELOPS OVER THE GREAT LAKES. STILL SOME UNCERTAINTY OF MAGNITUDE AND POSITION OF SYSTEM ALONG WITH AVAILABLE MOISTURE...THEREFORE WL MENTION CHC POPS ATTM...WITH TEMPS DROPPING BACK TO NEAR NORMAL. EXPECT ABOVE NORMAL LOW TEMPS THRU THE PERIOD...GIVEN AMOUNT OF BL MOISTURE AND POTENTIAL FOR CLOUDS/PRECIP...MAINLY IN THE U50S MTNS TO NEAR 70F CPV/SLV. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... THROUGH 00Z SUNDAY...MAINLY VFR THROUGH THE OVERNIGHT HOURS THOUGH MID TO HIGH-LEVEL CLOUDINESS WILL BE ON THE INCREASE PARTICULARLY AFTER MIDNIGHT. WINDS WILL BE LIGHT AND VARIABLE UNDER BROAD SFC RIDGING. FOR SATURDAY...EXPECTING SHOWERS AND THUNDERSTORMS AND DEVELOPING SOUTHEASTWARD WITH TIME. EXACT TIMING ON THE ONSET OF PRECIPITATION IS DIFFICULT IT IS DEPENDENT ON WHAT EVOLVES WITH THE ONGOING CONVECTION ACROSS THE NORTHERN PLAINS/GREAT LAKES REGION TONIGHT. HOWEVER BASED ON PRESENT INDICATIONS THIS APPEARS TO BE IN THE 13-18Z TIMEFRAME. FOR NOW HAVE TREATED WITH VCSH DURING THAT PERIOD OF TIME. POTENTIAL FOR MVFR VISIBILITIES (BRIEF IFR VISIBILITIES POSSIBLE IN STEADIER/HEAVIER RAIN). WINDS WILL BE SOUTH/SOUTHWEST UNDER 10KTS...EXCEPT LIGHT/VARIABLE AT MSS. OUTLOOK 00Z SUNDAY THROUGH TUESDAY... MAINLY VFR CONDITIONS WL PREVAIL THRU THE TIME PERIOD WITH THE EXCEPTION OF BRIEF MVFR/IFR IN THE HEAVIER SHOWERS/STORMS. BEST CHCS FOR STORMS WL BE DURING THE AFTERNOON AND EARLY EVENING HRS THRU TUESDAY. IN ADDITION...SOME PATCHY EARLY MORNING FOG/BR WITH MVFR/IFR WL BE POSSIBLE IF ANY TAF SITE RECIEVES HEAVY RAINFALL FROM CONVECTION DURING THE DAYTIME. EXPECT MAINLY SOUTHERLY WINDS THRU THE PERIOD. && .EQUIPMENT... OBSERVATIONS FROM RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) REMAIN UNAVAILABLE DUE TO A TELEPHONE COMMS LINE ISSUE. THE FAA AOCC IS AWARE OF THE ISSUE...BUT THERE IS NO ESTIMATE AVAILABLE AT THIS TIME AS TO WHEN THIS COMMS OUTAGE WILL BE FIXED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...SISSON SHORT TERM...SISSON LONG TERM...TABER AVIATION...TABER/LOCONTO EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
348 PM EDT FRI JUN 21 2013 .SYNOPSIS... HIGH PRESSURE ANCHORED OFF THE ATLANTIC COAST WILL KEEP THE NORTH COUNTRY DRY TODAY WITH PARTLY TO MOSTLY SUNNY SKIES THIS AFTERNOON AND TEMPERATURES IN THE MID 70S TO LOWER 80S. A WARM FRONT WILL MOVE SLOWLY THROUGH THE AREA ON SATURDAY WITH SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM WITH TEMPERATURES AGAIN RANGING THROUGH THE 70S NORTHEAST TO THE LOWER 80S SOUTHWEST. EVEN WARMER AND MORE HUMID CONDITIONS ARE EXPECTED SUNDAY INTO NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 323 PM EDT FRIDAY...TONIGHT BEGINS WITH CLEAR TO PARTLY CLOUDY SKIES THIS EVENING...BUT CLOUD COVER WILL INCREASE AFTER MIDNIGHT AS DEBRIS CLOUDS FROM A MESOSCALE CONVECTIVE COMPLEX AND IT`S ASSOCIATED VORTICITY OVER THE UPPER GREAT LAKES RIDES EAST SOUTHEASTWARD ALONG THE A DEVELOPING WARM FRONTAL BOUNDARY OVER OUR AREA. TEMPS WILL RUN RIGHT AROUND SEASONAL NORMALS IN THE 50S TO NEAR 60 IN THE VALLEYS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 323 PM EDT FRIDAY...SATURDAY...MODERATE CONFIDENCE CONTINUES THAT WE`LL SEE SOME SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM AS THE DECAYING MCV AND SHORT WAVE TROF MOVES ACROSS THE REGION DURING MIDDAY INTO THE EARLY EVENING. MODEL GUIDANCE HAS BEEN STRUGGLING WITH THE PLACEMENT OF THIS FEATURE WITH THE GFS MORE WIDESPREAD AND FURTHER SOUTH AND THE NAM FURTHER NORTH. HAVE PLAYED IT MORE TOWARD THE GFS/MAV SOLUTION AS RAP ANALYSIS SHOWS SIGNIFICANT MCV HAS FORMED. SO HIGHER POPS THAN WHAT THE NAM MOS SUGGESTS AND SLIGHT COOLER TEMPERATURES. HAVE STAYED MAINLY NEAR 80 WITH COOLER TEMPS NORTHEAST AND WARMER SOUTHWEST. WHERE CLOUDS/SHOWERS HANG ON IT COULD BE 5 DEGREES COOLER AND WHERE THEY DISSIPATE 5 DEGREES WARMER. IN THE ABSENCE OF ANY LARGE SCALE FORCING...ANY CONVECTIVE ACTIVITY WILL DISSIPATE GOING INTO THE EVENING AND OVERNIGHT HOURS SAT NIGHT WITH LOWS MAINLY IN THE 60S. ON SUNDAY...MORE TYPICAL ISOLATED TO SCATTERED AIRMASS TYPE PULSE SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SUNDAY MAINLY IN THE MID TO LATE AFTERNOON/EVENING WITH ACTIVITY SETTLING DOWN OVERNIGHT SUNDAY NIGHT. CAPE VALUES NOT ALL THAT IMPRESSIVE (BELOW 100 J/KG) WITH GFS SUGGESTING A CAPPING SUBSIDENCE INVERSION MAY BE IN PLACE SO KEPT A MINIMAL CHANCE POPS IN THE FOREAST. IT SHOULD BE CONSIDERABLY WARMER AND MORE HUMID AIR PUSHES IN AS THE WARM FRONT LIFTS NORTHEAST SUNDAY WITH HIGHS IN THE 80S. SUNDAY NIGHT SHOULD BE VERY MILD WITH READINGS IN THE 60S PERHAPS NEAR 70 AT BTV WITH WARM AND HUMID AIR FIRMLY ENTRENCHED. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 350 PM EDT FRIDAY...LARGE SCALE PATTERN WL CONTINUE TO SUPPORT MID/UPPER LVL RIDGE ACRS THE SE CONUS WITH FAST WESTERLY FLW ALOFT NEAR THE INTERNATIONAL BORDER THRU EARLY NEXT WEEK. BY MID TO LATE NEXT WEEK ALL GUIDANCE SUGGESTS A PATTERN CHANGE WITH DEVELOPMENT OF FULL LATITUDE TROF ACRS THE GREAT LAKES/EASTERN CONUS AND LARGE RIDGE OVER THE INTER-MOUNTAIN WEST. THIS WL RESULT IN MUCH ABOVE NORMAL TEMPS FOR MONDAY/TUESDAY WITH CHCS FOR AFTN/EVENING SHOWERS/STORMS...WITH A TREND TWD COOLER AND WETTER CONDITIONS BY LATE NEXT WEEK...AS TROF DEVELOPS AND SFC LOW PRES IMPACTS OUR FA. PROGGED 85H TEMPS NEAR 16C AND 925MB TEMPS BTWN 20-22C ON MONDAY/TUESDAY...SUPPORTS HIGHS WELL INTO THE 80S WITH EVEN A FEW LOWER 90S POSSIBLE IN THE WARMER VALLEY LOCATIONS. IN ADDITION...PROGGED SFC DWPTS ARE EXPECTED TO BE IN THE MID/UPPER 60S...CREATING VERY MUGGY CONDITIONS...ESPECIALLY ON MONDAY. THIS HEAT/HUMIDITY WL HELP TO PRODUCE SOME MODEST CAPE VALUES...COMBINED WITH EMBEDDED 5H VORTS WL HELP IN THE DEVELOPMENT OF AFTN/EVENING SHOWERS/STORMS. WL CONT TO MENTION CHC POPS ATTM...WITH MAIN FOCUS DURING THE PEAK HEATING HRS. ANY STORMS THAT DUE DEVELOP WL HAVE THE POTENTIAL TO PRODUCE LOCALIZED HEAVY DOWNPOURS WITH PW VALUES BTWN 1.50 AND 1.75". BETTER DYNAMICS AND MOISTURE ARRIVES BY LATE NEXT WK...AS MID/UPPER LVL TROF DEVELOPS OVER THE GREAT LAKES. STILL SOME UNCERTAINTY OF MAGNITUDE AND POSITION OF SYSTEM ALONG WITH AVAILABLE MOISTURE...THEREFORE WL MENTION CHC POPS ATTM...WITH TEMPS DROPPING BACK TO NEAR NORMAL. EXPECT ABOVE NORMAL LOW TEMPS THRU THE PERIOD...GIVEN AMOUNT OF BL MOISTURE AND POTENTIAL FOR CLOUDS/PRECIP...MAINLY IN THE U50S MTNS TO NEAR 70F CPV/SLV. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... THROUGH 18Z SATURDAY...AVIATION CHALLENGE WL BE POTENTIAL FOR RAIN SHOWERS WITH EMBEDDED RUMBLES OF THUNDER AFT 12Z SAT. CRNT VIS SATL PIC SHOWS A FEW FAIR WX CUMULUS CLOUDS ACRS THE MTNS...OTHERWISE SKIES ARE CLR ATTM. VFR CONDITIONS WL PREVAIL OVERNIGHT WITH CLOUDS INCREASING FROM WEST TO EAST ACRS OUR TAF SITES. THE COMBINED OF S/W ENERGY AND MID LVL MOISTURE WL RIDE ALONG A SFC BOUNDARY ON SATURDAY TO PRODUCE SHOWERS LIKELY. WL MENTION VCSH ATTM AFT 15Z FOR OUR CENTRAL/NORTHERN TAF SITES...WITH NO RESTRICTION TO VIS ANTICIPATED. LIGHT SOUTH TO SOUTHWEST WINDS TODAY...WL BECM TRRN DRIVEN OVERNIGHT...BEFORE SHIFTING BACK TO THE SOUTH ON SATURDAY. OUTLOOK 18Z SATURDAY THROUGH TUESDAY... MAINLY VFR CONDITIONS WL PREVAIL THRU THE TIME PERIOD WITH THE EXCEPTION OF BRIEF MVFR/IFR IN THE HEAVIER SHOWERS/STORMS. BEST CHCS FOR STORMS WL BE DURING THE AFTERNOON AND EARLY EVENING HRS THRU TUESDAY. IN ADDITION...SOME PATCHY EARLY MORNING FOG/BR WITH MVFR/IFR WL BE POSSIBLE IF ANY TAF SITE RECIEVES HEAVY RAINFALL FROM CONVECTION DURING THE DAYTIME. EXPECT MAINLY SOUTHERLY WINDS THRU THE PERIOD. && .EQUIPMENT... OBSERVATIONS FROM RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) REMAIN UNAVAILABLE DUE TO A TELEPHONE COMMS LINE ISSUE. THE FAA AOCC IS AWARE OF THE ISSUE...BUT THERE IS NO ESTIMATE AVAILABLE AT THIS TIME AS TO WHEN THIS COMMS OUTAGE WILL BE FIXED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...SISSON SHORT TERM...SISSON LONG TERM...TABER AVIATION...TABER EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
323 PM EDT FRI JUN 21 2013 .SYNOPSIS... HIGH PRESSURE ANCHORED OFF THE ATLANTIC COAST WILL KEEP THE NORTH COUNTRY DRY TODAY WITH PARTLY TO MOSTLY SUNNY SKIES THIS AFTERNOON AND TEMPERATURES IN THE MID 70S TO LOWER 80S. A WARM FRONT WILL MOVE SLOWLY THROUGH THE AREA ON SATURDAY WITH SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM WITH TEMPERATURES AGAIN RANGING THROUGH THE 70S NORTHEAST TO THE LOWER 80S SOUTHWEST. EVEN WARMER AND MORE HUMID CONDITIONS ARE EXPECTED SUNDAY INTO NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 323 PM EDT FRIDAY...TONIGHT BEGINS WITH CLEAR TO PARTLY CLOUDY SKIES THIS EVENING...BUT CLOUD COVER WILL INCREASE AFTER MIDNIGHT AS DEBRIS CLOUDS FROM A MESOSCALE CONVECTIVE COMPLEX AND IT`S ASSOCIATED VORTICITY OVER THE UPPER GREAT LAKES RIDES EAST SOUTHEASTWARD ALONG THE A DEVELOPING WARM FRONTAL BOUNDARY OVER OUR AREA. TEMPS WILL RUN RIGHT AROUND SEASONAL NORMALS IN THE 50S TO NEAR 60 IN THE VALLEYS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 323 PM EDT FRIDAY...SATURDAY...MODERATE CONFIDENCE CONTINUES THAT WE`LL SEE SOME SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM AS THE DECAYING MCV AND SHORT WAVE TROF MOVES ACROSS THE REGION DURING MIDDAY INTO THE EARLY EVENING. MODEL GUIDANCE HAS BEEN STRUGGLING WITH THE PLACEMENT OF THIS FEATURE WITH THE GFS MORE WIDESPREAD AND FURTHER SOUTH AND THE NAM FURTHER NORTH. HAVE PLAYED IT MORE TOWARD THE GFS/MAV SOLUTION AS RAP ANALYSIS SHOWS SIGNIFICANT MCV HAS FORMED. SO HIGHER POPS THAN WHAT THE NAM MOS SUGGESTS AND SLIGHT COOLER TEMPERATURES. HAVE STAYED MAINLY NEAR 80 WITH COOLER TEMPS NORTHEAST AND WARMER SOUTHWEST. WHERE CLOUDS/SHOWERS HANG ON IT COULD BE 5 DEGREES COOLER AND WHERE THEY DISSIPATE 5 DEGREES WARMER. IN THE ABSENCE OF ANY LARGE SCALE FORCING...ANY CONVECTIVE ACTIVITY WILL DISSIPATE GOING INTO THE EVENING AND OVERNIGHT HOURS SAT NIGHT WITH LOWS MAINLY IN THE 60S. ON SUNDAY...MORE TYPICAL ISOLATED TO SCATTERED AIRMASS TYPE PULSE SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SUNDAY MAINLY IN THE MID TO LATE AFTERNOON/EVENING WITH ACTIVITY SETTLING DOWN OVERNIGHT SUNDAY NIGHT. CAPE VALUES NOT ALL THAT IMPRESSIVE (BELOW 100 J/KG) WITH GFS SUGGESTING A CAPPING SUBSIDENCE INVERSION MAY BE IN PLACE SO KEPT A MINIMAL CHANCE POPS IN THE FOREAST. IT SHOULD BE CONSIDERABLY WARMER AND MORE HUMID AIR PUSHES IN AS THE WARM FRONT LIFTS NORTHEAST SUNDAY WITH HIGHS IN THE 80S. SUNDAY NIGHT SHOULD BE VERY MILD WITH READINGS IN THE 60S PERHAPS NEAR 70 AT BTV WITH WARM AND HUMID AIR FIRMLY ENTRENCHED. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 339 AM EDT FRIDAY...FOR THE EXTENDED PERIOD...THE ENTIRE NORTH COUNTRY WILL SEE WARM/HOT TEMPS...HUMID CONDITIONS AND THE CHANCE FOR RW/TRW FOR ALMOST THE ENTIRE TIMEFRAME. THE SETUP FOR THE AFOREMENTIONED CONDITIONS... LATEST MDLS CONTINUE TO SHOW LARGE BLOCKING RIDGE TO SET UP OVER SOUTHERN AND EASTERN PORTIONS OF THE COUNTRY. SFC FLOW AROUND THE RIDGE WILL BRING IN WARM/HUMID AIR...WHICH CURRENTLY RESIDES OVER CENTRAL/SOUTHERN PORTIONS OF THE COUNTRY. 850/925 TEMPS THRU PERIOD RANGE FROM +18C TO +24C...SUPPORTING MDL GUIDANCE NUMBERS OF M/U 80S TO AROUND 90F IN SPOTS...AND OVERNGT LOWS IN THE U50S TO M60S. MANY AREA THOUGH WILL HAVE DAYTIME HIGHS TEMPERED BY CLD COVER FROM DIURNAL HEATING(CREATING TRW/RW)...AND A COUPLE OF WK SYSTEMS RIDING OVER NORTHERN PORTIONS OF THE RIDGE...WITH MAIN FOCUS OVER N NY. GOING INTO NEXT WED/THURS MDLS DO DIFFER ON TIMING/PLACEMENT OF APPROACHING LOW DIGGING OUT OF CENTRAL CANADA. W/ GFS BRINGING THRU GREAT LKS AND LATEST ECMWF HAVE SYSTEM DIVE SE FROM CENTRAL CANADA AND INTO CWA. BOTH MDLS SUGGEST PRECIP WILL OCCUR W/ MAIN FOCUS OVER WESTERN PORTIONS OF THE CWA...SO HAVE CONCENTRATED HIGHER POPS THERE. OVERALL THESE TWO DAYS HAVE BETTER CHANCES FOR CONVECTION BROUGHT ABOUT BY DYNAMICS OF APPROACHING LOW/TROUGH. BEGINNING PORTION OF FORECAST PERIOD WILL SEE ANY TRW FOCUS ALONG NORTHERN HALF OF CWA AS RIDGE WILL KEEP SOUTHWARD PUSH TO A MINIMUM. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... THROUGH 18Z SATURDAY...AVIATION CHALLENGE WL BE POTENTIAL FOR RAIN SHOWERS WITH EMBEDDED RUMBLES OF THUNDER AFT 12Z SAT. CRNT VIS SATL PIC SHOWS A FEW FAIR WX CUMULUS CLOUDS ACRS THE MTNS...OTHERWISE SKIES ARE CLR ATTM. VFR CONDITIONS WL PREVAIL OVERNIGHT WITH CLOUDS INCREASING FROM WEST TO EAST ACRS OUR TAF SITES. THE COMBINED OF S/W ENERGY AND MID LVL MOISTURE WL RIDE ALONG A SFC BOUNDARY ON SATURDAY TO PRODUCE SHOWERS LIKELY. WL MENTION VCSH ATTM AFT 15Z FOR OUR CENTRAL/NORTHERN TAF SITES...WITH NO RESTRICTION TO VIS ANTICIPATED. LIGHT SOUTH TO SOUTHWEST WINDS TODAY...WL BECM TRRN DRIVEN OVERNIGHT...BEFORE SHIFTING BACK TO THE SOUTH ON SATURDAY. OUTLOOK 18Z SATURDAY THROUGH TUESDAY... MAINLY VFR CONDITIONS WL PREVAIL THRU THE TIME PERIOD WITH THE EXCEPTION OF BRIEF MVFR/IFR IN THE HEAVIER SHOWERS/STORMS. BEST CHCS FOR STORMS WL BE DURING THE AFTERNOON AND EARLY EVENING HRS THRU TUESDAY. IN ADDITION...SOME PATCHY EARLY MORNING FOG/BR WITH MVFR/IFR WL BE POSSIBLE IF ANY TAF SITE RECIEVES HEAVY RAINFALL FROM CONVECTION DURING THE DAYTIME. EXPECT MAINLY SOUTHERLY WINDS THRU THE PERIOD. && .EQUIPMENT... OBSERVATIONS FROM RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) REMAIN UNAVAILABLE DUE TO A TELEPHONE COMMS LINE ISSUE. THE FAA AOCC IS AWARE OF THE ISSUE...BUT THERE IS NO ESTIMATE AVAILABLE AT THIS TIME AS TO WHEN THIS COMMS OUTAGE WILL BE FIXED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...SISSON SHORT TERM...SISSON LONG TERM...JN AVIATION...TABER EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
240 PM EDT FRI JUN 21 2013 .SYNOPSIS... HIGH PRESSURE ANCHORED OFF THE ATLANTIC COAST WILL KEEP THE NORTH COUNTRY DRY TODAY WITH PARTLY TO MOSTLY SUNNY SKIES THIS AFTERNOON AND TEMPERATURES IN THE MID 70S TO LOWER 80S. A WARM FRONT WILL MOVE SLOWLY THROUGH THE AREA ON SATURDAY WITH SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM WITH TEMPERATURES AGAIN RANGING THROUGH THE 70S NORTHEAST TO THE LOWER 80S SOUTHWEST. EVEN WARMER AND MORE HUMID CONDITIONS ARE EXPECTED SUNDAY INTO NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 239 PM EDT FRIDAY...PREVIOUS FORECAST ON TRACK FOR HIGHS IN THE UPPER 70S TO LOWER 80S UNDER PARTLY TO MOSTLY SUNNY SKIES WITH SOME FAIR WEATHER CUMULUS. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... AS OF 239 PM EDT FRIDAY...TONIGHT BEGINS WITH PARTLY CLOUDY SKIES THIS EVENING...BUT CLOUD COVER WILL INCREASE TOWARDS MIDNIGHT AS DEBRIS CLOUDS FROM A MESOSCALE CONVECTIVE COMPLEX AND IT`S ASSOCIATED VORTICITY OVER THE UPPER GREAT LAKES RIDES EAST SOUTHEASTWARD ALONG THE A DEVELOPING WARM FRONTAL BOUNDARY OVER OUR AREA. TEMPS WILL RUN RIGHT AROUND SEASONAL NORMALS IN THE 50S TO NEAR 60 IN THE VALLEYS. FOR SATURDAY...MODERATE CONFIDENCE CONTINUES THAT WE`LL SEE SOME SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM AS THE DECAYING MCV AND SHORT WAVE TROF MOVES ACROSS THE REGION DURING MIDDAY INTO THE EARLY EVENING. EL RIDGE ACROSS THE GREAT LAKES REGION AND DEVELOP SHOWERS AND THUNDERSTORMS ACROSS THE BTV CWA DURING THE MID-DAY TO EVENING HOURS. BUT MODEL GUIDANCE HAS BEEN STRUGGLING WITH THE PLACEMENT OF THIS FEATURE WITH THE GFS MORE WIDESPREAD AND FURTHER SOUTH AND THE NAM FURTHER NORTH. HAVE PLAYED IT MORE TOWARD THE GFS/MAV SOLUTION AS RAP ANALYSIS SHOWS SIGNIFICANT MCV HAS FORMED. SO HIGHER POPS THAN WHAT THE NAM MOS SUGGEST AND SLIGHT COOLER TEMPERATURES. HAVE STAYED MAINLY NEAR 80 COOLER NORTHEAST AND WARMER SOUTHWEST, BUT WHERE CLOUDS/SHOWERS HANG ON IT COULD BE 5 DEGREES COOLER AND WHERE THEY DISSIPATE 5 DEGREES WARMER. IN THE ABSENCE OF ANY LARGE SCALE FORCING...ANY CONVECTIVE ACTIVITY WILL DISSIPATE GOING INTO THE EVENING AND OVERNIGHT HOURS SAT NIGHT WITH LOWS MAINLY IN THE 60S. ON SUNDAY...MORE TYPICAL SCATTERED AIRMASS TYPE PULSE SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SUNDAY MAINLY IN THE MID TO LATE AFTERNOON/EVENING WITH ACTIVITY SETTLING DOWN OVERNIGHT SUNDAY NIGHT. IT SHOULD BE CONSIDERABLY WARMER AND MORE HUMID AIR PUSHES IN AS THE WARM FRONT LIFTS NORTHEAST SUNDAY WITH HIGHS IN THE 80S. SUNDAY NIGHT SHOULD BE VERY MILD WITH READINGS IN THE 60S PERHAPS NEAR 70 AT BTV AS WARMER AND MORE HUMID AIR PUSHES IN AS THE WARM FRONT LIFTS NORTHEAST. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 339 AM EDT FRIDAY...FOR THE EXTENDED PERIOD...THE ENTIRE NORTH COUNTRY WILL SEE WARM/HOT TEMPS...HUMID CONDITIONS AND THE CHANCE FOR RW/TRW FOR ALMOST THE ENTIRE TIMEFRAME. THE SETUP FOR THE AFOREMENTIONED CONDITIONS... LATEST MDLS CONTINUE TO SHOW LARGE BLOCKING RIDGE TO SET UP OVER SOUTHERN AND EASTERN PORTIONS OF THE COUNTRY. SFC FLOW AROUND THE RIDGE WILL BRING IN WARM/HUMID AIR...WHICH CURRENTLY RESIDES OVER CENTRAL/SOUTHERN PORTIONS OF THE COUNTRY. 850/925 TEMPS THRU PERIOD RANGE FROM +18C TO +24C...SUPPORTING MDL GUIDANCE NUMBERS OF M/U 80S TO AROUND 90F IN SPOTS...AND OVERNGT LOWS IN THE U50S TO M60S. MANY AREA THOUGH WILL HAVE DAYTIME HIGHS TEMPERED BY CLD COVER FROM DIURNAL HEATING(CREATING TRW/RW)...AND A COUPLE OF WK SYSTEMS RIDING OVER NORTHERN PORTIONS OF THE RIDGE...WITH MAIN FOCUS OVER N NY. GOING INTO NEXT WED/THURS MDLS DO DIFFER ON TIMING/PLACEMENT OF APPROACHING LOW DIGGING OUT OF CENTRAL CANADA. W/ GFS BRINGING THRU GREAT LKS AND LATEST ECMWF HAVE SYSTEM DIVE SE FROM CENTRAL CANADA AND INTO CWA. BOTH MDLS SUGGEST PRECIP WILL OCCUR W/ MAIN FOCUS OVER WESTERN PORTIONS OF THE CWA...SO HAVE CONCENTRATED HIGHER POPS THERE. OVERALL THESE TWO DAYS HAVE BETTER CHANCES FOR CONVECTION BROUGHT ABOUT BY DYNAMICS OF APPROACHING LOW/TROUGH. BEGINNING PORTION OF FORECAST PERIOD WILL SEE ANY TRW FOCUS ALONG NORTHERN HALF OF CWA AS RIDGE WILL KEEP SOUTHWARD PUSH TO A MINIMUM. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... THROUGH 18Z SATURDAY...AVIATION CHALLENGE WL BE POTENTIAL FOR RAIN SHOWERS WITH EMBEDDED RUMBLES OF THUNDER AFT 12Z SAT. CRNT VIS SATL PIC SHOWS A FEW FAIR WX CUMULUS CLOUDS ACRS THE MTNS...OTHERWISE SKIES ARE CLR ATTM. VFR CONDITIONS WL PREVAIL OVERNIGHT WITH CLOUDS INCREASING FROM WEST TO EAST ACRS OUR TAF SITES. THE COMBINED OF S/W ENERGY AND MID LVL MOISTURE WL RIDE ALONG A SFC BOUNDARY ON SATURDAY TO PRODUCE SHOWERS LIKELY. WL MENTION VCSH ATTM AFT 15Z FOR OUR CENTRAL/NORTHERN TAF SITES...WITH NO RESTRICTION TO VIS ANTICIPATED. LIGHT SOUTH TO SOUTHWEST WINDS TODAY...WL BECM TRRN DRIVEN OVERNIGHT...BEFORE SHIFTING BACK TO THE SOUTH ON SATURDAY. OUTLOOK 18Z SATURDAY THROUGH TUESDAY... MAINLY VFR CONDITIONS WL PREVAIL THRU THE TIME PERIOD WITH THE EXCEPTION OF BRIEF MVFR/IFR IN THE HEAVIER SHOWERS/STORMS. BEST CHCS FOR STORMS WL BE DURING THE AFTERNOON AND EARLY EVENING HRS THRU TUESDAY. IN ADDITION...SOME PATCHY EARLY MORNING FOG/BR WITH MVFR/IFR WL BE POSSIBLE IF ANY TAF SITE RECIEVES HEAVY RAINFALL FROM CONVECTION DURING THE DAYTIME. EXPECT MAINLY SOUTHERLY WINDS THRU THE PERIOD. && .EQUIPMENT... OBSERVATIONS FROM RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) REMAIN UNAVAILABLE DUE TO A TELEPHONE COMMS LINE ISSUE. THE FAA AOCC IS AWARE OF THE ISSUE...BUT THERE IS NO ESTIMATE AVAILABLE AT THIS TIME AS TO WHEN THIS COMMS OUTAGE WILL BE FIXED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...SISSON SHORT TERM...SISSON LONG TERM...JN AVIATION...TABER EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1242 PM EDT FRI JUN 21 2013 .SYNOPSIS... TODAY IS THE OFFICIAL START OF SUMMER. A SLOW-MOVING FRONT OFFSHORE WILL DRIFT WEST AND ONSHORE EARLY SATURDAY...INCREASING THE RISK FOR SHOWERS AND THUNDERSTORMS. TYPICAL SUMMERTIME WEATHER IS EXPECTED NEXT WEEK WITH BERMUDA HIGH PRESSURE AND THE PIEDMONT TROUGH BECOMING THE DOMINANT SURFACE FEATURES. && .NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM FRIDAY...FAIRLY THICK CLOUDS IN THE WILMINGTON/CAPE FEAR AREA HAVE HELD TEMPERATURES TO 80 DEGREES SO FAR...WITH NO INLAND CONVECTION SO FAR. I HAVE TRIMMED POPS BACK TO ONLY 30 PERCENT THROUGH 6 PM FOR THIS AREA GIVEN RECENTLY HRRR RUNS SHOWING LESSER INDICATED COVERAGE ON ITS LAST SEVERAL RUNS. ALONG THE SC COAST THE HRRR CONTINUES TO INDICATE SOME POTENTIAL FOR SCATTERED SHOWER/T-STORM DEVELOPMENT THIS AFTERNOON SO DESPITE THE CURRENT MOSTLY CLEAR/PARTLY CLOUDY SKIES I AM MAINTAINING 20-40 PERCENT CHANCES THERE. NO SIGNIFICANT CHANGES HAVE BEEN MADE FARTHER INLAND WHERE MAINLY SUNNY SKIES HAVE ALLOWED TEMPERATURES TO RISE INTO THE LOWER 80S ALONG AND WEST OF THE I-95 CORRIDOR. SOME UPPER 80S MAY EVEN OCCUR FOR HIGHS TODAY FROM LUMBERTON WEST THROUGH BENNETTSVILLE. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS... YESTERDAY`S STALLED FRONT IS SHOWN ON SATELLITE IMAGERY AND ON MODEL ANALYSES TO BE LOCATED ABOUT 50 MILES SOUTHEAST OF BALD HEAD ISLAND NC. THE FRONT WILL MOVE A LITTLE CLOSER TO THE COAST TODAY BUT SHOULD REMAIN OFFSHORE. THIS MOVEMENT IS BEING AIDED BY HIGH PRESSURE OVER THE WEST-CENTRAL ATLANTIC DEVELOPING A SUBSTANTIAL FETCH OF EAST AND SOUTHEAST WINDS ACROSS THE BAHAMAS AND WESTERN ATLANTIC. A RIBBON OF DEEP MID LEVEL MOISTURE LOCATED OVER THE FRONT WILL ALSO ADVECT CLOSER TO THE COAST TODAY AND TONIGHT...AIDED BY THE CIRCULATION AROUND A WEAK MID AND UPPER LEVEL LOW ACROSS NORTHERN GEORGIA AND EASTERN TENNESSEE. MORNING LOW CLOUDS ALONG THE COAST ARE BURNING OFF BUT THERE IS A DEEP ENOUGH LOW-LEVEL INVERSION ON THE 12Z MHX AND CHS SOUNDINGS THAT THIS MOISTURE WILL LIKELY JUST CREATE A STRATOCUMULUS DECK A LITTLE HIGHER UP...AT LEAST UNTIL THIS INVERSION CAN BREAK AS TEMPERATURES RISE TO AROUND 80 BY NOON OR SO. AT THIS POINT ISOLATED SHOWERS MAY BEGIN TO DEVELOP WITH LIMITED CONVECTIVE INSTABILITY (CAPE: 500-800 J/KG) IN REGIONS CLOSE ENOUGH TO THE COAST TO HAVE DEWPOINTS IN THE MID 60S OR HIGHER. FARTHER INLAND FOR FLORENCE AND LUMBERTON THE AIRMASS IS CONSIDERABLY DRIER AND ANY CUMULUS CLOUD DEVELOPMENT WILL BE SUBSTANTIALLY DELAYED UNTIL MID TO LATE AFTERNOON WHEN ENOUGH MOISTURE FINALLY ADVECTS THAT FAR WEST. CHANGES TO THE FORECAST THIS MORNING INCLUDE RAISING HIGH TEMPERATURE FORECASTS INLAND A DEGREE OR TWO...CUTTING POPS BY 10-20 PERCENT THROUGH THE DAY AND REMOVING REMOVING POPS WEST OF INTERSTATE 95...AND ADJUSTING CLOUD COVER FORECASTS TO REFLECT THE PRESENCE OF THE SUBSTANTIAL AREA OF DRY AIR INLAND. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 AM FRIDAY...WEAK QUASI-STATIONARY FRONT/COASTAL TROUGH WILL BE NEAR THE COAST AT THE START OF THE PERIOD. THIS FEATURE WILL SLOWLY MOVE INLAND SAT INTO SUN WITH CONVECTION DEVELOPING ALONG AND BEHIND THE BOUNDARY. COASTAL AREAS WILL BE FAVORED AS BOUNDARY IS NOT EXPECTED TO MOVE VERY FAR INLAND DURING SAT. WEAK MID LEVEL PATTERN AND DIFFUSE NATURE OF THE SURFACE TROUGH WILL KEEP ACTIVITY DIURNAL IN NATURE SO COVERAGE SHOULD DECREASE WITH THE LOSS OF HEATING SAT EVENING. SUN SHOULD BE SIMILAR TO SAT BUT WITH ACTIVITY DEVELOPING A LITTLE EARLIER AND A LITTLE FARTHER INLAND. VERY LITTLE WILL BE LEFT OF THE COASTAL TROUGH AT THIS POINT BUT ITS REMAINS MAY STILL HELP GENERATE THE FIRST ROUND OF CONVECTION SUN. SEA BREEZE WILL HELP GET ACTIVITY GOING CLOSER TO THE COAST. WILL MAINTAIN CHC POP FOR BOTH SAT AND SUN BUT WITH AN INCREASE SAT AND SLIGHT REDUCTION FOR SUN. MORE CONVERGENCE ALONG THE BOUNDARY SAT SUGGEST BETTER POP CHANCES EARLY. LIMITED CONVERGENCE AND INCREASING SUBSIDENCE AS WEAK MID LEVEL RIDGE BUILDS SUN BOTH WORK TO SUPPRESS CONVECTION. TEMPERATURES BELOW CLIMO FOR SAT WILL INCREASE SLIGHTLY SUN AS HEIGHTS/THICKNESS START TO INCREASE UNDER BUILDING RIDGE AND SOUTHERLY FLOW BECOMES ESTABLISHED. LOWS WILL BE NEAR CLIMO BOTH NIGHTS...HELD UP BY LINGERING DEBRIS CLOUDS AND MOIST LOW LEVEL SOUTHERLY FLOW. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 3 AM FRIDAY...PERIOD WILL BE MARKED BY A TYPICAL SUMMER PATTERN. BERMUDA HIGH AND PIEDMONT TROUGH COMBO AT THE SURFACE WITH WEAK RIDGING ALOFT. THIS SETUP WILL BRING PLENTY OF DEEP MOISTURE TO THE REGION WITH PRECIPITABLE WATER VALUES APPROACHING 2 INCHES NEXT WEEK. EXPECT CONVECTION ON BOTH THE SEA BREEZE AND PIEDMONT TROUGH THROUGHOUT THE PERIOD. LATER IN THE WEEK STRENGTHENING 5H RIDGE OVER THE WEST STATES WEAKENS RIDGING OVER THE SOUTHEAST. THIS SHOULD RESULT IN AN INCREASE IN STORM COVERAGE LATE NEXT WEEK. WILL MAINTAIN INHERITED DIURNAL CHC POP WITH AN SLIGHT INCREASE LATE IN THE PERIOD. TEMPERATURES WILL BE NEAR CLIMO AT THE START OF THE PERIOD BUT THEN BEGIN A STEADY INCREASE AS SUMMER TAKES HOLD. BOTH GFS/ECMWF INCREASE 850 TEMPS FROM 15C MON MORNING TO NEAR 20C BY THE END OF THE PERIOD. && .AVIATION /12Z FRIDAY THROUGH WEDNESDAY/... AS OF 12Z...MOISTURE LURKING OFFSHORE WILL SLOWLY EDGE TOWARD THE COAST THROUGH THE AFTERNOON. SOME ISOLATED/SCATTERED CONVECTION IS EXPECTED...PERHAPS MOVING INLAND BY LATE AFTERNOON WITH A WEAK SEABREEZE. TONIGHT DEEPER MOISTURE BEGINS TO IMPINGE THE COAST...WITH MODERATE TO HEAVY SHOWERS EXPECTED AT THE MYRTLE BEACH AIRPORTS AFTER MIDNIGHT...AND POTENTIALLY MAKING IT TO ILM A COUPLE OF HOURS LATER. SATURDAY...SCATTERED SHOWERS ARE EXPECTED THROUGH THE END OF THE FORECAST PERIOD...WITH LBT AND FLO GETTING INTO THE ACT BY MID MORNING. CONTINUED LIGHT NORTHEAST SFC WINDS THROUGH THE PERIOD...A BIT MORE EASTERLY ALONG THE COAST. EXTENDED OUTLOOK...MODERATE CHANCE OF SHOWERS THROUGH WEDNESDAY AS A STALLED FRONT LINGERS NEAR THE COAST. BEST CHANCE FOR PRECIP WILL BE IN THE AFTERNOON...WITH LOCAL MVFR/IFR CONDITIONS POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM FRIDAY...THE WORST OF THE NORTHEAST WINDS APPEAR TO BE OVER AS EXPECTED. BUOY AND BEACHFRONT WEATHER STATIONS ARE SHOWING WINDS 3-5 KNOTS LESS THAN EARLIER THIS MORNING. THIS IMPROVING TREND SHOULD CONTINUE INTO THE AFTERNOON AS THE OFFSHORE FRONT DRAWS A LITTLER NEARER TO THE COASTAL WATERS. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS... YESTERDAY`S STALLED FRONT IS NOW BEGINNING TO PUSH WESTWARD TOWARD THE COAST. SATELLITE AND MODEL ANALYSIS SHOWS THE BOUNDARY IS ABOUT 50 MILES SOUTHEAST OF BALD HEAD ISLAND...OR APPROXIMATELY 20 MILES SOUTHEAST OF THE FRYING PAN SHOALS BUOY WHERE INCIDENTALLY A NORTHEAST WIND CONTINUES. THE BOUNDARY WILL MAKE ONLY A LITTLE PROGRESS WESTWARD THROUGH THE AFTERNOON HOURS WITH A MAINLY NORTHEAST WIND EXPECTED WITHIN THE COASTAL WATERS. WIND SPEEDS ARE STRONGEST THIS MORNING...A SOLID 15 KNOTS WITH 20 KNOT GUSTS STILL BEING OBSERVED AT THE FRYING PAN SHOALS BUOY AND ON BALD HEAD ISLAND. THE PRESSURE GRADIENT WILL WEAKEN THIS AFTERNOON WITH WIND SPEEDS DIMINISHING TO 10-15 KNOTS. SEAS REMAIN IN THE 3-5 FT RANGE WITH A BROAD SPECTRUM OF WAVE PERIODS FROM 4-10 SECONDS OBSERVED ON SPECTRAL WAVE OUTPUT FROM THE FRYING PAN SHOALS BUOY. THE WAVEWATCH MODEL SHOWS A DOMINANT WAVE PERIOD AROUND 6 SECONDS TODAY WITH A NOTABLE WAVE TRAIN AT 9 SECONDS PERIOD TOO. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 AM FRIDAY...ILL DEFINED GRADIENT DURING THE PERIOD WILL KEEP WIND SPEEDS UNDER 10 KT THROUGH SUN NIGHT. NORTHEAST TO EAST FLOW SAT MORNING WILL BECOME EAST TO SOUTHEAST DURING THE DAY AS WEAK TROUGH MOVES ONSHORE. ELONGATED SURFACE RIDGE OFF THE MID ATLANTIC COAST SLIDES SOUTH SAT NIGHT INTO SUN WITH LIGHT WINDS GRADUALLY VEERING FROM EAST-SOUTHEAST TO SOUTH-SOUTHEAST. SEAS WILL RUN 2 TO 3 FT MAINLY AS WEAK EASTERLY SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 3 AM FRIDAY...SOUTHWEST FLOW WILL PERSIST THROUGH THE PERIOD WITH BERMUDA HIGH PRESSURE AND PIEDMONT TROUGH BEING THE MAIN SURFACE FEATURES. LITTLE CHANGE TO THE GRADIENT THROUGH THE PERIOD WILL KEEP WINDS 10 TO 15 KT WITH SLIGHTLY HIGHER SPEEDS EACH AFTERNOON AS TROUGH BECOMES MORE DEFINED. SEAS RUN 2 TO 4 FT WITH SOUTHERLY SWELL BECOMING MORE NOTICEABLE. && .TIDES/COASTAL FLOODING... AS OF 3 AM FRIDAY...TIDAL RANGES ARE EXPANDING WITH THE ARRIVAL OF THE FULL MOON ON SUNDAY. THE DOWNTOWN WILMINGTON TIDE GAUGE DID BRIEFLY EXCEED ITS MINOR COASTAL FLOOD THRESHOLD LAST EVE. HOWEVER...THE DEPARTURES MAY NOT BE AS SIGNIFICANT TONIGHT GIVEN THE ONSHORE FLOW WILL BE WEAKER. WILL NOT ISSUE ANY COASTAL FLOOD ADVISORIES AT THIS TIME. HOWEVER...WE WILL CONTINUE TO CLOSELY MONITOR TRENDS. ALTHOUGH WATER LEVELS WILL BE ELEVATED DURING BOTH HIGH TIDE CYCLES INTO EARLY NEXT WEEK...BOTH ALONG THE CAPE FEAR RIVER AND THE COAST...THE HIGHEST OF THE PREDICTED TIDES IS THE PM TIDE. HIGH TIDE TONIGHT IS 630 PM ALONG THE IMMEDIATE COAST AND NEAR 830 PM ALONG THE CAPE FEAR RIVER IN DOWNTOWN WILMINGTON. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...III AVIATION...43 TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
117 PM CDT FRI JUN 21 2013 .UPDATE... ISSUED AT 120 PM CDT FRI JUN 21 2013 MODIFIED POPS BASED ON LATEST RADAR. DAYTIME TEMPERATURES ALSO TRENDED COOLER WITH EXTENSIVE CLOUDINESS IN PLACE. MAIN THUNDERSTORM COMPLEX OVER SOUTH CENTRAL NORTH DAKOTA...ADVECTING EAST AND SLIGHTLY NORTH. UPDATE ISSUED AT 1100 AM CDT FRI JUN 21 2013 WILL ALLOW THE DENSE FOG ADVISORY TO EXPIRE AT 11 AM CDT. VISIBILITIES CONTINUE TO IMPROVE ACROSS WEST AND CENTRAL NORTH DAKOTA. PATCHY AREAS OF FOG MAY LINGER INTO THE AFTERNOON SOME LOCATIONS WITH VERY HIGH BOUNDARY LAYER MOISTURE IN PLACE...WITH SURFACE DEWPOINTS IN THE 60S TO EVEN AROUND 70F SOME LOCATIONS. LATEST RAP (13Z AND 14Z RUNS) SEEMS TO BE DOING THE BEST SO FAR WITH CURRENT SHOWERS AND STORMS...WEST AND SOUTH WITH THE HEAVIER ECHOS SOUTHWEST OVER ADAMS AND HETTINGER COUNTIES. SKIES SHOULD REMAIN MAINLY CLOUDY THROUGHOUT THE DAY ALONG WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...SOME SEVERE...WITH NUMEROUS EMBEDDED WAVES LIFTING ACROSS THE DAKOTAS. BEST CHANCE FOR WIDESPREAD CONVECTION WITH SEVERE WEATHER AND HEAVY RAIN WILL BE MID/LATE AFTERNOON INTO THIS EVENING WITH PEAK HEATING AND INSTABILITY MAXIMIZED. MODELS ARE KEYING IN ON CONVECTION FIRING UP ACROSS SOUTH DAKOTA LIFTING NORTH AND EAST TODAY INTO THIS EVENING...WITH A DRY/QUIET PERIOD IN THE WAKE OF THIS ACTIVITY LATE TONIGHT. WITH RICH BOUNDARY LAYER MOISTURE REMAINING IN PLACE...REDEVELOPMENT OF FOG AND STRATUS IS LOOKING LIKELY ONCE SKIES TREND SCT-SKC. UPDATE ISSUED AT 908 AM CDT FRI JUN 21 2013 MAIN UPDATE WAS TO EXTEND THE DENSE FOG ADVISORY UNTIL 11 AM CDT WITH SEVERAL AREA OBSERVING SITES REPORTING 1/4 MILE OR LESS STILL. UPDATE ISSUED AT 618 AM CDT FRI JUN 21 2013 UPDATE TO ISSUE DENSE FOG ADVISORY FOR PORTIONS OF THE FORECAST AREA AS OBS/WEBCAMS/SPOTTER REPORTS INDICATING DENSE FOG COVERAGE IS NOW SIGNIFICANT...AND WARRANTS HEADLINES. ALSO INCREASED POPS SLIGHTLY FAR WEST PER LATEST RADAR TRENDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 402 AM CDT FRI JUN 21 2013 THE HIGHLIGHT OF THE SHORT TERM IS SEVERE CONVECTIVE POTENTIAL THIS AFTERNOON THROUGH TONIGHT. THE MAIN QUESTION IS HOW QUICKLY CAPPING WILL BE ERODED TO ALLOW FOR SURFACE BASED CONVECTION THIS AFTERNOON. THE 00 UTC NAM/GFS BUFR SOUNDINGS DO VARY SIGNIFICANTLY IN REGARDS TO THE STRENGTH OF THIS CAPPING...WITH THE GFS HOLDING A STRONG CAP THROUGH THE AFTERNOON...WITH THE NAM SHOWING LITTLE CONVECTIVE INHIBITION BY 18 UTC. THE 03 UTC SREF SOUNDINGS DO SHOW WEAKER CAPPING THAN THE GFS...HOWEVER...THE 00 UTC 4 KM WRF HAS LITTLE AFTERNOON CONVECTION ACROSS THE AREA. THUS...DID LIMIT POPS TO SLIGHT CHANCE OR CHANCE PRIOR TO 00 UTC. SHOULD CAPPING BE ERODED...ML CAPE VALUES OF 2500-3500 J/KG WITH 50 KTS OF DEEP LAYER SHEAR ARE AVAILABLE...WITH VERY LARGE HAIL POSSIBLE GIVEN -10 TO -30 C CAPE VALUES NEAR 1000 J/KG. THE BETTER CHANCES FOR THUNDERSTORMS ARE THIS EVENING AND TONIGHT WITH A POTENTIAL MCS PROPAGATING OUT OF SOUTH DAKOTA WITH THE ARRIVAL OF GREATER UPPER LEVEL FORCING. IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...HEAVY RAINFALL WILL BECOME AN INCREASING THREAT...ESPECIALLY FOR THOSE AREAS IMPACTED BY HEAVY RAINFALL WEDNESDAY AND THURSDAY...WITH PWATS 1.50 INCHES AND K INDEX VALUES OF 35-40 C. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 402 AM CDT FRI JUN 21 2013 THE MAIN FORECAST CONCERNS DURING THE LONG TERM PERIOD ARE THE POTENTIAL FOR CONTINUED HEAVY RAIN AND FLASH FLOODING OVER THE WEEKEND. MODEL CONSENSUS INDICATES AN UPPER TROUGH MOVING INTO THE NORTHERN PLAINS SATURDAY AND SATURDAY NIGHT. BROAD SYNOPTIC LIFT WILL SUPPORT WIDESPREAD SHOWERS AND THUNDERSTORMS...ESPECIALLY LATER IN THE DAY. THE JAMES RIVER VALLEY WILL AGAIN BE UNDER THE GUN FOR ADDITIONAL FLOODING...ALONG WITH ISOLATED SEVERE STORMS. BY SUNDAY...THE UPPER LOW WILL LIFT NORTH WITH THE FOCUS OF SHOWERS AND STORMS ACROSS THE NORTHERN COUNTIES...WHICH WILL DIMINISH SUNDAY NIGHT. SOUTHWEST FLOW WILL PERSIST MONDAY AND TUESDAY WITH RAIN EXPECTED TO BE MORE SCATTERED ACROSS THE STATE. BY THURSDAY...AN UPPER RIDGE WILL BEGIN TO SPREAD INTO WESTERN NORTH DAKOTA. CLOUDS WILL KEEP AFTERNOON TEMPS DOWN MAINLY IN THE 70S OVER THE WEEKEND...FOLLOWED BY NEAR TO SLIGHTLY ABOVE NORMAL TEMPS IN THE LOW 80S BY EARLY TO MID WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 120 PM CDT FRI JUN 21 2013 STRATUS WILL CONTINUE ACROSS PORTIONS OF WESTERN AND CENTRAL NORTH DAKOTA GIVEN THE HUMID AIRMASS IN PLACE...WITH MVFR CONDITIONS EXPECTED AT TIMES. THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON INTO THIS EVENING. STRATUS AND FOG EXPECTED TO REDEVELOP OVERNIGHT INTO SATURDAY MORNING. && .HYDROLOGY... ISSUED AT 120 PM CDT FRI JUN 21 2013 EXPANDED THE FLASH FLOOD WATCH INTO EMMONS COUNTY GIVEN THE SIGNIFICANT RAINFALL THAT OCCURRED THURSDAY EVENING. MULTIPLE ROUNDS OF STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED FRIDAY THROUGH SUNDAY...WITH ADDITIONAL HEAVY RAINFALL POSSIBLE FOR THOSE LOCATIONS THAT HAVE SEEN SIGNIFICANT RAINFALL AMOUNTS WEDNESDAY NIGHT AND THURSDAY EVENING ACROSS SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY. SOILS HAVE LITTLE TO NO CAPACITY TO HOLD ADDITIONAL WATER...ENHANCING RUNOFF AND THE POTENTIAL TO AGGRAVATE THE ONGOING OVERLAND FLOODING ACROSS THE AREA. A COMPLEX OF THUNDERSTORMS WITH HEAVY RAINFALL IS EXPECTED FRIDAY EVENING AND NIGHT...AND AGAIN SATURDAY NIGHT INTO SUNDAY. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE WITH LOCALLY HIGHER AMOUNTS. && .BIS WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR NDZ023-025-036-037- 046>048-050-051. && $$ UPDATE...NH LONG TERM...RP KINNEY HYDROLOGY...AYD/NH AVIATION...NH
AREA FORECAST DISCUSSION
NWS NORMAN OK
1221 PM CDT FRI JUN 21 2013 .DISCUSSION... REFER TO THE 18Z AVIATION FORECAST BELOW... && .AVIATION... EXPECT MAINLY VFR CONDITIONS WITH GUSTY SOUTH WINDS TO PREVAIL THROUGH THE TAF PERIOD. VERY ISOLATED SHRA AND OR TSRA MAY DEVELOP AT TERMINALS ACROSS SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS. THESE WILL LARGELY BE DRIVEN BY DAYTIME HEATING...AND SHOULD DIMINISH AROUND SUNSET. STRONGER STORMS WILL BE CAPABLE OF STRONG AND GUSTY WINDS...BUT OVERALL IMPACTS SHOULD REMAIN MINOR. && .PREV DISCUSSION... /ISSUED 1036 AM CDT FRI JUN 21 2013/ DISCUSSION... WEAK ECHOES OVER THE PANHANDLES CONTINUE ON RADARS...BUT THERE IS LITTLE OR NO ACTUAL PRECIPITATION HITTING THE GROUND...AND EASTWARD PROGRESS HAS BEEN VERY SLOW. OUR EXISTING 10-15 PERCENT POPS IN FAR NORTHWEST OKLAHOMA ARE PROBABLY A BIT OPTIMISTIC...BUT DO SEEM REASONABLE AT THIS POINT. SHORT-RANGE MODELS STILL SHOW ISOLATED OR SCATTERED CONVECTION DEVELOPING THIS AFTERNOON OVER SOUTHWEST OKLAHOMA. THE EXISTING POPS AGAIN LOOK REASONABLE FOR NOW. AS MENTIONED PREVIOUSLY...ANY STORMS THAT DEVELOP IN THIS ENVIRONMENT WILL BE PULSE STORMS...WITH RAPID DEVELOPMENT...SHORT DURATION...AND THE POTENTIAL FOR STRONG WINDS AND HEAVY RAIN. OTHERWISE...TODAY WILL BE ANOTHER WARM...HUMID...AND BREEZY DAY ACROSS OKLAHOMA AND NORTH TEXAS. NO CHANGES TO THE CURRENT FORECAST ARE PLANNED FOR THIS MORNING. PREV DISCUSSION... /ISSUED 658 AM CDT FRI JUN 21 2013/ UPDATE... REDUCED RAIN CHANCES THIS MORNING ACROSS NORTHWEST OKLAHOMA. ADDED 10 PERCENT ISOLATED MENTION ACROSS LOCATIONS SOUTHWEST OF A ENID TO STILLWATER LINE THIS AFTERNOON. DISCUSSION... CONVECTION OVER NORTHWEST OKLAHOMA HAS DISSIPATED THIS MORNING...BUT MAY REDEVELOP OVER THE NEXT FEW HOURS. LATEST HRRR RUNS HAVE BEEN CONSISTENT IN DEVELOPING A FEW STORMS NEAR A VERNON TO LAWTON TO OKLAHOMA CITY LINE BETWEEN 1 AND 5 PM THIS AFTERNOON. THUS...ADDED A 10 PERCENT ISOLATED MENTION IN THESE LOCATIONS. IF THESE STORMS DEVELOP... THEY COULD BE STRONG WITH GUSTY WINDS AND LOCALLY HEAVY RAINFALL AS THEY WOULD BE SLOW MOVERS AND PULSE IN NATURE. PRODUCTS HAVE BEEN UPDATED. MBS PREV DISCUSSION... /ISSUED 622 AM CDT FRI JUN 21 2013/ DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. SOUTH WINDS WILL INCREASE AND BECOME GUSTY AT ALL SITES BY 15Z...THEN BE SLOW TO DIMINISH AFTER 01Z ACROSS WESTERN OKLAHOMA. MVFR CEILINGS SHOULD STAY JUST SOUTH OF KSPS-KMLC AND DISSIPATE BY 18Z. CHANCES FOR TSRA AND NON CONVECTIVE LOW LEVEL WIND SHEAR APPEAR TO BE TOO LOW TO MENTION. MBS PREV DISCUSSION... /ISSUED 357 AM CDT FRI JUN 21 2013/ DISCUSSION... HOT AND MAINLY RAINFREE WEATHER WILL BE THE MAIN STORY OVER THE NEXT SEVERAL DAYS. THIS MORNING...A FEW HIGH BASED THUNDERSTORMS WILL CONTINUE OVER FAR NORTHWEST OKLAHOMA...MAINLY NORTHWEST OF A CHEYENNE TO ALVA LINE. NO SEVERE STORMS ARE EXPECTED. KEPT 10-30 PERCENT...ISOLATED TO SCATTERED COVERAGE MENTION THIS MORNING IN THESE AREAS...THOUGH THESE STORMS MAY DISSIPATE QUICKLY OVER THE NEXT HOUR OR TWO. THIS AFTERNOON AND EARLY THIS EVENING...GENERALLY EXPECT ANOTHER HOT AND DRY DAY. SOME LATEST HRRR GUIDANCE HINTED THAT ISOLATED TO SCATTERED STORMS MAY DEVELOP NEAR A VERNON TO LAWTON TO OKLAHOMA CITY LINE BETWEEN 1 AND 5 PM...WEAKENING TOWARDS SUNSET. THE ONLY NOTICEABLE TRIGGER FOR LIFT WOULD BE A WEAK SHORT WAVE/POSSIBLE MCV CURRENTLY NEAR LUBBOCK TEXAS. CHANCES OF STORMS DEVELOPING SEEM TOO LOW TO MENTION AT THIS TIME DUE TO STRONG CAPPING...THOUGH WILL CLOSELY MONITOR. IF STORMS DEVELOP...A FEW PULSE MICROBURSTS WITH GUSTY WINDS AND LOCALLY HEAVY RAIN WOULD BE POSSIBLE AS THE AIR WILL BE UNSTABLE. LATER TONIGHT THROUGH THURSDAY...GENERALLY HOT AND RAINFREE WEATHER WILL CONTINUE. LIKE YESTERDAY EVENING...A FEW STORMS MAY MOVE INTO FAR WESTERN OR NORTHWESTERN OKLAHOMA EACH NIGHT...BUT ODDS ARE GOOD THAT MOST LOCATIONS WILL STAY DRY. THINK HIGHS WILL INCREASE SLIGHTLY EACH DAY...ESPECIALLY AS THE GROUND DRIES OUT. A WEAK FRONT MAY MAKE IT TOWARDS THE AREA LATE WEDNESDAY INTO THURSDAY WHICH COULD BRING A BIT HIGHER RAIN CHANCES TO THE AREA. FOR NOW...KEPT RAIN CHANCES BELOW 20 PERCENT DURING THIS TIME FRAME. TEMPERATURES WILL GENERALLY BE 5 TO 10 DEGREES ABOVE AVERAGE. WEDNESDAY MAY BE THE HOTTEST DAY WITH TRIPLE DIGIT HEAT ACROSS MUCH OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 72 95 72 94 / 10 0 10 10 HOBART OK 71 100 71 99 / 10 0 10 10 WICHITA FALLS TX 72 99 72 98 / 10 0 0 0 GAGE OK 70 97 70 96 / 10 10 10 10 PONCA CITY OK 72 95 72 94 / 10 10 10 10 DURANT OK 72 94 72 93 / 0 10 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 23/84/84
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
316 PM CDT FRI JUN 21 2013 .SHORT TERM... FORECAST REVOLVES AROUND THUNDER CHANCES LATE THIS AFTERNOON INTO TONIGHT. THE REGION REMAINS UNDER SOUTHWEST FLOW ALOFT...WITH ONE NOTABLE SHORTWAVE TROUGH ACROSS THE PANHANDLES EXITING TO THE NORTHEAST AND ANOTHER AREA OF LIFT SEEN ON WATER VAPOR IMAGERY APPROACHING THROUGH AZ. WAS CONCERNED THE FIRST WAVE COULD SPARK A FEW STORMS ACROSS THE EASTERN ZONES THIS AFTERNOON...AS EARLIER RAP AND HRRR SOLUTIONS SUGGESTED...BUT THEY HAVE NOW BACKED OFF ON THIS AND WITH WAVE EXITING PROSPECTS FOR THIS ARE LOW. ALTHOUGH WE WILL BE POSITIONED BETWEEN THE TWO SYNOPTIC AREAS OF FORCING FOR ASCENT THIS EVENING...STRONG HEATING AND GOOD MOISTURE LEVELS WERE RESULTING IN STRONG INSTABILITY AND MINIMAL INHIBITION OVER MUCH OF THE REGION...WITH 19Z MLCAPE VALUES ANALYZED AOA 2500 J/KG FOR MOST OF THE FA. IN ADDITION...AN AREA OF LOW-LEVEL MOISTURE CONVERGENCE WAS NOTED FROM THE CENTRAL TEXAS PANHANDLE SOUTHWESTWARD INTO THE LEE TROUGH ACROSS SOUTHEASTERN NEW MEXICO. UP TO THIS POINT...STORMS HAVE BEEN CONFINED TO LOCATIONS IMMEDIATELY ALONG AND EAST OF THE SACRAMENTO MOUNTAINS...BUT EXPECT ADDITIONAL DEVELOPMENT NORTHEASTWARD FROM THERE UP INTO THE WESTERN/CENTRAL PANHANDLE THROUGH LATE THIS AFTERNOON. THE ACTIVITY MAY TRY AND CONGEAL SOMEWHAT AS IT MOVES EASTWARD ACROSS THE CAPROCK THIS EVENING...PERHAPS MAKING IT INTO THE ROLLING PLAINS LATER TONIGHT...THOUGH IT SHOULD BE WANING IN INTENSITY BY LATE EVENING. EARLY ON...STRONG INSTABILITY AND WEAK TO MODEST WIND SHEAR WILL SUPPORT A SEVERE THREAT WITH LARGE HAIL...DAMAGING WINDS...LOCALLY HEAVY RAIN AND THE PROSPECTS FOR BLOWING DUST. HAVE EXPANDED CHANCE POPS TO ENCOMPASS NEARLY THE ENTIRE SOUTHERN PANHANDLE AND SOUTH PLAINS THROUGH 06Z BEFORE DROPPING POPS BELOW 15 PERCENT AFTER 06Z. TEMPERATURES TONIGHT WILL BE MILD AS MOIST SOUTHERLY LOW-LEVEL FLOW CONTINUES AND HAVE GONE WITH TEMPERATURES SIMILAR TO WHAT WE SAW THIS MORNING. TOMORROW WILL BRING ANOTHER HOT DAY WITH LITTLE CHANGE IN THE OVERALL PATTERN. STRONG DAYTIME HEATING...WITH HIGHS IN THE MIDDLE 90S AND SUFFICIENT MOISTURE...COMBINED WITH CONVERGENCE ALONG A SFC TROUGH/DRYLINE WILL BRING ANOTHER THREAT OF STRONG/SEVERE STORMS...FAVORING THE WESTERN ZONES INITIALLY IN THE LATE AFTERNOON HOURS...THEN EXPANDING EAST. && .LONG TERM... MAIN ISSUE TODAY IS TIMING TRANSITION FROM AFTN THUNDERSTORM REGIME ACROSS THE WRN ZONES TO HOT AND DRY AREAWIDE. 12Z MODEL RUNS NOW A BIT SLOWER IN REPLACING THE WRN CONUS UPPER TROUGH WITH AN AMPLIFYING RIDGE. IT NOW LOOKS LIKE THE LEE SFC TROUGH COULD REMAIN ACTIVE INTO MONDAY WITH SWLY FLOW ALOFT BEFORE THAT RIDGE AMPLIFICATION BEGINS OVER THE SRN ROCKIES. THAT SHOULD FINALLY SHUT PRECIPITATION DOWN OVER THE AREA. AS A RESULT HAVE EXTENDED SLIGHT CHANCE MENTION INTO MONDAY AFTN AND EVENING. TEMPS WILL THEN WARM AS THE RIDGE BUILDS OVER THE ROCKIES AND LOW LEVELS DRY OUT A BIT...WITH HIGH TEMPS LIKELY APPROACHING 10F WARMER THAN NORMAL BY WEDNESDAY AND THURSDAY. WILL END WITH MENTION OF AN OUTSIDE SHOT OF PRECIP REENTERING THE PICTURE TOWARD FRIDAY AS NORTHERLY MID TO UPPER FLOW OVER THE PLAINS COULD SEND A COLD FRONT AND/OR UPPER DISTURBANCE TOWARD THE FCST AREA. FOR NOW THAT POSSIBILITY TOO REMOTE TO ADD TO FCST. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 93 63 94 63 / 30 20 20 20 20 TULIA 66 94 66 96 67 / 30 20 20 20 20 PLAINVIEW 68 93 68 95 68 / 30 20 20 20 20 LEVELLAND 69 93 68 93 69 / 30 20 20 20 20 LUBBOCK 73 93 70 96 69 / 30 10 20 20 20 DENVER CITY 67 95 68 96 69 / 30 20 20 20 20 BROWNFIELD 70 94 68 95 70 / 30 20 20 20 20 CHILDRESS 72 97 70 97 70 / 20 10 10 10 10 SPUR 72 95 71 95 70 / 20 10 10 10 10 ASPERMONT 73 97 72 97 71 / 20 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/07
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1246 PM CDT FRI JUN 21 2013 .AVIATION... BREEZY SOUTHERLY WINDS WERE BEGINNING TO LOFT SOME BLDU AT LBB AGAIN THOUGH NOT QUITE TO THE DEGREE OF YESTERDAY AT THIS SAME TIME. STILL...THINK VISIBILITIES WILL DROP TO MVFR LEVELS THIS AFTERNOON BEFORE IMPROVING THIS EVENING WHEN WINDS SUBSIDE AND/OR SHOWERS CLEAR OUT THE AIR. OTHER CONCERN REVOLVES AROUND CONVECTIVE CHANCES AT THE TERMINALS THIS AFTERNOON INTO THE EVENING. CDS OR LBB COULD SEE A STORM FROM MID-LATE AFTN THROUGH THE EVENING. THINK BEST CHANCES WILL BE AT LBB THIS EVENING THOUGH CONFIDENCE NOT TERRIBLY HIGH OF A DIRECT IMPACT. THUS HAVE INCLUDED A VCTS MENTION AT LBB FROM 23-03Z...THOUGH WILL OBVIOUSLY MONITOR CLOSELY AND AMEND AS NECESSARY. && .PREV DISCUSSION... /ISSUED 1059 AM CDT FRI JUN 21 2013/ UPDATE... MINOR UPDATE TO EXPAND POPS TO INCLUDE THE EASTERN ZONES THIS AFTERNOON. ALSO CHANGED BLOWING DUST MENTION FROM PATCHY TO AREAS ON MUCH OF THE CAPROCK INTO THE WESTERN ROLLING PLAINS FOR THIS AFTERNOON INTO THE EVENING HOURS. MORNING WATER VAPOR IMAGERY SHOWS SOUTHWESTERLY FLOW ALOFT OVER THE REGION...WITH A RIBBON OF MID-LEVEL MOISTURE STRETCHING FROM KANSAS SOUTHWARD THROUGH OKLAHOMA...THE EASTERN PANHANDLES AND THROUGH THE EASTERN 1/2 OF THE CWA THEN TO POINTS SOUTH AND SOUTHWEST. THIS SUB-TROPICAL MOISTURE FETCH WAS IN ADVANCE OF A EAST-NORTHEASTWARD MOVING SHORTWAVE TROUGH THAT HAS ALREADY AIDED IN A FEW SHOWERS/STORMS ACROSS THE CENTRAL PANHANDLE THIS MORNING. RECENT HRRR AND RAP GUIDANCE INDICATE SAID FACTORS WILL BE ENOUGH TO DEVELOP ISOLATED TO SCATTERED MOIST CONVECTION OFF THE CAPROCK THIS AFTERNOON AND FOR THIS REASON HAVE INSERTED A SLIGHT CHANCE OF STORMS THERE AFTER 18Z. FURTHER WEST...DRIER MID-LEVEL AIR IS WORKING INTO THE REGION...BUT THE SFC TROUGH AND STRONG HEATING SHOULD BE ENOUGH TO POP ADDITIONAL ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON SOMEWHERE NEAR OR JUST WEST OF THE TX/NM LINE...WHICH WILL MOVE EASTWARD THROUGH THE EVENING HOURS WHILE GRADUALLY WANING IN INTENSITY. FAIRLY STRONG INSTABILITY /SBCAPES PUSHING 2000 J/KG/ AND MODEST DEEP LAYER SHEAR /GENERALLY AOB 35 KNOTS/ COULD SUPPORT A FEW STRONG/SEVERE CELLS...THOUGH OVERALL STORM ORGANIZATION WILL LIKELY BE LIMITED. IN ADDITION TO THE POSSIBILITY OF DUSTY OUTFLOWS WITH ANY CONVECTION...BREEZY SOUTHERLY WINDS WILL LIKELY RESULT IN A FAIR AMOUNT OF BLOWING DUST AGAIN THIS AFTERNOON INTO THE EVENING...SIMILAR TO YESTERDAY. THE REMAINDER OF THE FORECAST REMAINS IN GOOD SHAPE. UPDATE PRODUCTS HAVE BEEN SENT. PREV DISCUSSION... /ISSUED 638 AM CDT FRI JUN 21 2013/ AVIATION... BREEZY SOUTH WINDS WILL GUST TO NEAR 30 KNOTS TODAY AS A SURFACE TROUGH REMAINS IN CLOSE PROXIMITY TO BOTH TERMINALS. THEREFORE...WILL LEAVE PREVAILING MVFR CONDITIONS IN FOR BOTH SITES FROM MID-LATE MORNING THROUGH MID EVENING GIVEN THE LIKELIHOOD OF BLOWING DUST AGAIN TODAY. KLBB WILL SEE A BETTER CHANCE FOR SHOWERS OR STORMS IN THE VICINITY THAN KCDS...BUT CONFIDENCE IN COVERAGE IS NOT HIGH ENOUGH AT THIS TIME TO WARRANT MENTION. PREV DISCUSSION... /ISSUED 409 AM CDT FRI JUN 21 2013/ SHORT TERM... ISOLATED SHOWERS AND EMBEDDED THUNDER WILL CONTINUE TO WANE INTO THE EARLY MORNING HOURS. TIGHTENING SURFACE TROUGH NEAR THE NEW MEXICO STATE LINE ALONG WITH POSITIONING BEHIND A WAKE LOW NEAR THE INTERSTATE 40 CORRIDOR EAST OF AMARILLO HAVE KEPT WIND GUSTS IN THE 40 TO 50 MPH RANGE ON AN ABERNATHY TO FLOYDADA LINE. SHOULD SEE THESE STRONG GUSTS EXIT TO THE NORTH AND EAST AS THE WAKE LOW MOVES OFF IN THIS DIRECTION AND PRESSURE GRADIENT SOMEWHAT WEAKENS AWAY FROM THE TROUGH AXIS. SOUTHWEST FLOW REGIME WILL MAINTAIN ITSELF ALOFT TODAY AS BROAD TROUGHING BLANKETS MUCH OF THE WESTERN CONUS WITH UPPER RIDGING SOUTHEAST OF WEST TEXAS. FALLING PRESSURES IN CORRESPONDENCE WITH THE ABOVE REFERENCED DEEPENING SURFACE TROUGH EXTENDING FROM THE FRONT RANGE INTO EASTERN NEW MEXICO WILL LEAD TO THE BEST THUNDERSTORM CHANCES ACROSS THE FAR SOUTHWEST PANHANDLE AND WESTERN SOUTH PLAINS. RIBBON OF THETA-E VALUES WILL BE HIGHEST HERE WITH GREATER INSTABILITY AS SUFFICIENT MOISTURE REMAINS IN PLACE WITH DEWPOINTS IN THE UPPER 50S TO LOWER 60S. MORE PRONOUNCED ELEVATED MIXED LAYER TO THE EAST INTO THE ROLLING PLAINS AND EXTREME SOUTHEAST PANHANDLE WILL PRECLUDE CONVECTIVE INITIATION...BUT A 30 TO 40 KNOT LOW LEVEL JET AND INCREASING DEEP LAYER SHEAR TO NEAR 30 KNOTS MAY BE ENOUGH FOR PREEXISTING ACTIVITY TO SKIRT EAST OFF THE CAPROCK. STEEP LAPSE RATES ON EITHER SIDE OF THE ELEVATED MIXED LAYER AND RELATIVELY DRY NEAR SURFACE AIR DUE TO TEMPERATURES IN THE 90S WILL PROMOTE LARGE HAIL AND WIND GUSTS OF 50 TO 60 MPH IN STRONGER STORMS WEST OF THE ESCARPMENT DURING THE AFTERNOON AND EARLY EVENING. STORMS SHOULD WIND DOWN POST DIURNAL HEATING AND LEAVE A FEW STRAGGLING SHOWERS MOVING TO THE NORTH AND EAST. WINDS WILL REMAIN IN THE 10 TO 15 MPH RANGE OVERNIGHT AND COMBINE WITH RESIDUAL MOISTURE TO KEEP LOW TEMPERATURES A FEW DEGREES ABOVE CLIMATOLOGY...RANGING FROM THE MID TO UPPER 60S ON THE CAPROCK AND UPPER 60S TO LOW 70S IN THE ROLLING PLAINS AND FAR SOUTHEAST PANHANDLE. LONG TERM... BY SATURDAY MORNING...ELONGATED UPPER LOW WILL BE POSITIONED FROM IDAHO TO NORTHERN AB/SK WITH BROAD SOUTHWESTERLY FLOW ACROSS THE CENTRAL STATES. HIGH WILL CONTINUE TO STRENGTHEN ACROSS THE SOUTHEASTERN USA THOUGH THERE WILL BE A WEAKNESS OUT NEAR THE SMOKY MTNS. THE HIGH WILL BUILD AND SHIFT EAST TO WEST BY THE MIDDLE OF NEXT WEEK BEFORE STRENGTHENING FURTHER OVER THE FOUR CORNERS BY LATE IN THE WEEK WITH THE PATTERN LARGELY REMAINING STAGNANT OUT THROUGH 240 HOURS. INDICATIONS SUGGEST THAT THE WET PATTERN ACROSS OUR WESTERN ZONES WILL CONTINUE THROUGH AT LEAST SUNDAY WITH LESS OPPORTUNITY MONDAY EVENING AND THEREAFTER AS PATTERN CHANGES OVERHEAD. HAVE BUMPED POPS SAT/SUN AND TRIMMED MONDAY LEAVING THINGS DRY THEREAFTER. TEMPERATURES WILL BE ON THE INCREASE NEXT WEEK WITH VALUES APPROACHING THE CENTURY MARK BY MID WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 94 63 95 63 / 30 20 20 20 20 TULIA 66 93 66 94 66 / 30 20 20 20 20 PLAINVIEW 68 93 67 93 67 / 30 20 20 20 20 LEVELLAND 68 94 68 94 67 / 30 20 20 20 20 LUBBOCK 69 94 69 94 68 / 20 10 20 20 20 DENVER CITY 67 94 69 95 68 / 30 20 20 20 20 BROWNFIELD 68 94 69 94 69 / 20 20 20 20 20 CHILDRESS 70 97 70 96 71 / 20 10 10 10 10 SPUR 70 97 71 97 70 / 20 10 10 10 10 ASPERMONT 71 99 72 98 72 / 20 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
355 PM CDT FRI JUN 21 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 355 PM CDT FRI JUN 21 2013 AT 3 PM...A THUNDERSTORM COMPLEX WAS LOCATED OVER EASTERN SOUTH DAKOTA. THE HRRR SEEMS TO BE HANDLING THIS SYSTEM THE BEST THIS AFTERNOON. IT SHOWS THAT THIS SYSTEM WILL MOVE NORTHEAST INTO NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA LATE THIS AFTERNOON AND EARLY EVENING. THIS SYSTEM IS INITIALLY FOLLOWING THE SHORT WAVE TROUGH. HOWEVER AS THE LOW LEVEL JET STRENGTHENS THIS EVENING AND STRONG 850 MB MOISTURE TRANSPORT WILL MOVE INTO THE FORECAST AREA. EXPECT SOME DEVELOPMENT ALONG THE ADVANCING WARM FRONT ON THE SOUTH OF THIS PERIPHERY OF THIS SYSTEM. MLCAPES ALONG THIS BOUNDARY CLIMB TO AROUND 5000 J/KG LATE THIS AFTERNOON AND THEN CONTINUES INTO THE EARLY EVENING. WHILE THE 0-6 KM SHEAR IS NOT FAVORABLE FOR SUPERCELLS...THE 0-3 KM BULK SHEAR IS OVER 40 KNOTS AND IT WILL BE FAVORABLE FOR DAMAGING WINDS. IN ADDITION WITH DCAPES OVER 1500 J/KG...THIS WOULD ALSO MAKE IT FAVORABLE FOR THE STORMS TO PRODUCE DAMAGING WINDS. CURRENTLY EXPECTING THE CURRENT CONVECTION TO EVOLVE INTO 1 OR MORE BOW ECHOS AS THEY BECOME MORE COLD POOL DOMINANT...AND THESE LINES WOULD LIKELY MOVE ALONG OR NORTH OF THE INTERSTATE 90 CORRIDOR BETWEEN 22.03Z AND 22.09Z. HOWEVER IF THE BOUNDARY DOES NOT LIFT AS FAR NORTH AS THE MESO MODELS INDICATE...THIS CONVECTION COULD POTENTIALLY BE FURTHER SOUTH TONIGHT. FLASH FLOODING IS ALSO A CONCERN TONIGHT AS WARM CLOUD LAYER DEPTHS CLIMB INTO THE 4 TO 4.5 KM RANGE AND PRECIPITABLE WATER VALUES CLIMB INTO THE 1.8 TO 2.0 INCH RANGE. WITH THE LOW LEVEL JET CONTINUING TO IMPINGE ON THE FRONT NEAR THE MINNESOTA AND IOWA BORDER...EXPECT CONVECTION TO CONTINUE TO DEVELOP ACROSS EASTERN NEBRASKA...WESTERN IOWA AND SOUTHWEST MINNESOTA THROUGHOUT THE NIGHT. THIS CONVECTION WOULD THEN TRAIN INTO THE FORECAST AREA WITH THE MEAN WIND. WOULD NOT BE SHOCKED TO SEE 3 TO 5 INCHES OF RAIN FALL ACROSS PARTS OF THE AREA TONIGHT. THERE MAY BE EVEN SOME LOCALLY HIGHER AMOUNTS. THIS LOOKS LIKE A CLASSIC MADDOX WARM FRONTAL FLASH FLOOD EVENT. DUE TO THIS...ISSUED A FLASH FLOOD WATCH FOR TONIGHT AND SATURDAY MORNING. THE SHOWERS AND THUNDERSTORMS WILL GRADUALLY DIMINISH ON SATURDAY MORNING AS THE LOW LEVEL JET WEAKENS. ON SATURDAY AFTERNOON...THE MODELS SHOW THAT THE WARM FRONT WILL MOVE NORTHWARD TOWARD THE INTERSTATE 94 CORRIDOR. WITH THERE NOT MUCH MOISTURE CONVERGENCE ALONG THIS FRONT AND SOME CAPPING ALOFT...THERE IS A POTENTIAL THAT THE COULD BE SOME DRY HOURS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 355 PM CDT FRI JUN 21 2013 ON SATURDAY NIGHT...MANY OF THE DETERMINISTIC MODELS SUGGEST THAT THE 850 MB MOISTURE TRANSPORT WILL SHIFT NORTHEAST OF THE AREA BY LATE EVENING. AS A RESULT...MANY OF THESE MODELS HAS THE FORECAST AREA DRYING OUT DURING THE 23.06Z TO 23.12Z TIME FRAME. IF THIS TREND CONTINUES...MAY HAVE TO LOWER OR POSSIBLY TAKE THESE PRECIPITATION CHANCES OUT OF THE FORECAST. FROM SUNDAY INTO TUESDAY...THE MODELS CONTINUE TO STRUGGLE WITH THE LOCATION OF THE FRONT AND WHERE MESOSCALE COMPLEXES MAY DEVELOP. AS A RESULT...THE FORECAST CONFIDENCE FOR THE TIMING AND LOCATION OF THE PRECIPITATION IS NOT AS CERTAIN. DUE TO THIS...STAYED WITH THE CONSALL PRECIPITATION CHANCES AND ALSO WITH THEIR MAXIMUM AND MINIMUM TEMPERATURES. ON ANY OF THESE DAYS...TEMPERATURES COULD EASILY CLIMB INTO THE LOWER 90S IF ENOUGH SUNSHINE CAN OCCUR. FROM WEDNESDAY INTO FRIDAY...THE DETERMINISTIC MODELS ARE SHOWING THAT THE UPPER LEVEL RIDGE WILL RETROGRADE INTO THE WESTERN UNITED STATES AND WESTERN CANADA. THIS IS IN RESPONSE TO A MODERATE MADDEN JULIAN OSCILLATION MOVING TOWARD THE INTERNATIONAL DATELINE. WHEN THIS OCCURS IN SUMMER...CLIMATE PREDICTION CENTER COMPOSITES FAVOR ABOVE NORMAL TEMPERATURE ANOMALIES ACROSS THE WESTERN UNITED STATES. AS A RESULT...CONFIDENCE IS HIGH THAT THIS WILL OCCUR...BUT THE EXACT TIME WHEN THIS WILL ULTIMATELY TAKE PLACE IS STILL A BIT UNCERTAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1150 AM CDT FRI JUN 21 2013 DIFFICULT FORECAST FOR SHRA/TS CHANCES AS VARIOUS SFC BOUNDARIES...UPPER AIR DISTURBANCES...AND POSITIONING OF THE LOW LEVEL MOISTURE TRANSPORT ARE ALL GOING TO HAVE A HAND IN WHERE PCPN DEVELOPS. GIVEN THIS SCENARIO...CONFIDENCE IS LOW IN PINPOINTING THE SHRA/TS CHANCES OUTSIDE OF A 6 HOUR WINDOW. THAT SAID...WEST-EAST RUNNING SFC BOUNDARY IS JUST SOUTH OF THE KRST/KLSE LATE THIS MORNING...AND IS SLATED TO EITHER LINGER THERE OR MOVE JUST A BIT NORTH. SHRA/TS COULD FIRE ALONG THE BOUNDARY LATER THIS AFTERNOON...ALTHOUGH LOOKS ISOLD AT THIS TIME. BETTER CHANCES WILL COME LATER TONIGHT AS A THUNDERSTORM COMPLEX IS EXPECTED TO DEVELOP OVER THE NORTHERN PLAINS...ROLLING EAST ACROSS THE REGION TONIGHT. MODELS GENERALLY FAVOR KEEPING IT NORTH OF I-90...BUT COULD IMPACT KRST/KLSE. AGAIN...WITH CONFIDENCE NOT HIGH IN TIMING/POSITIONING OF LIKELY CONVECTIVE COMPLEXES...WILL STAY WITH VCTS/VCSH MENTION. TAFS WILL BE UPDATED AS TRENDS BECOME CLEARER. && .HYDROLOGY...TONIGHT INTO SATURDAY ISSUED AT 355 PM CDT FRI JUN 21 2013 OVERNIGHT 1 TO 2 INCHES OF RAIN FELL ACROSS SOUTHEAST MINNESOTA...AND WEST CENTRAL AND NORTH CENTRAL WISCONSIN...AND 2 TO 4 INCHES FELL ACROSS NORTHEAST IOWA...AND SOUTHWEST AND CENTRAL WISCONSIN. THIS CAUSED RIVER FLOOD WARNINGS TO BE ISSUED ALONG THE BLACK AND KICKAPOO RIVERS IN WESTERN WISCONSIN. AS A STRONG LOW LEVEL JET BRINGS ABUNDANT MOISTURE INTO THE AREA TONIGHT. EXPECT THAT 3 TO 5 INCHES MAY FALL ACROSS PARTS OF THE AREA TONIGHT. A FEW LOCAL SPOTS MAY SEE EVEN HIGHER AMOUNTS. THINKING THAT THE BEST CHANCES ARE ALONG AND NORTH OF THE INTERSTATE 90 CORRIDOR. HOWEVER THERE IS STILL SOME UNCERTAINTY IN THIS. THIS ADDITIONAL RAIN WILL LIKELY RESULT IN SOME FLASH FLOODING TONIGHT. AS A RESULT...WENT WITH A FLASH FLOOD WATCH FOR THE ENTIRE AREA TONIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH FROM 9 PM CDT THIS EVENING THROUGH SATURDAY MORNING FOR WIZ017-029-032>034-041>044-053>055-061. MN...FLASH FLOOD WATCH FROM 9 PM CDT THIS EVENING THROUGH SATURDAY MORNING FOR MNZ079-086>088-094>096. IA...FLASH FLOOD WATCH FROM 9 PM CDT THIS EVENING THROUGH SATURDAY MORNING FOR IAZ008>011-018-019-029-030. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION.....RIECK HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1243 PM CDT FRI JUN 21 2013 .UPDATE...MCC CONTINUES HEADING SOUTHEAST AT STEADY PACE. LEADING EDGE OF SQUALL THAT HAS RECENTLY BEEN PRODUCING 25-35 KNOT GUSTS IS OVER RACINE/KENOSHA IS NOW OFFSHORE. LOCAL WAKE LOW PARAMETER SUGGESTS POTENTIAL FOR 40-50 MPH GUSTS ALONG BACK EDGE OF PRECIPITATION CURRENTLY FROM SAUK TO FOND DU LAC COUNTIES. HAVE RECENTLY SEEN GUSTS TO 34 KNOTS AT KDLL...33 KNOTS AT KFLD...AND 32 KNOTS AT KOSH. HAVE 35 KNOT GUSTS IN THE NEXT COUPLE HOURS OF GRIDS ACROSS NORTHERN TWO TIERS OF COUNTIES. HRRR AND LOCAL WSWRF 4KM ARW CORE SHOW THAT IT GETS QUIET FROM EARLY AFTERNOON INTO THIS EVENING...IN THE WAKE OF THE MCC. CHANCE POPS AFTER MIDNIGHT...BUT WITH LOW LEVEL JET FOCUSED WELL WEST IT SEEMS THAT WARM ADVECTION STORMS OVER TOP OF COLD POOL FROM MCS MAY BE HARDER TO ACHIEVE. CONSENSUS HAS CHANCE POPS AFTER MIDNIGHT...AND THAT LOOKS GOOD AS REMNANTS OF SD MCS TRY AND MAKE THEIR WAY INTO THE RIDGE AXIS LATE. CRAVEN && .AVIATION/18Z TAFS/...LINGERING SHOWERS AND STORMS WITH SOME IFR/MVFR VISIBILITIES WILL DIMINISH OVER THE NEXT HOUR OR SO ACROSS TAF SITES. DRY CONDITIONS ARE THEN EXPECTED THROUGH THE REST OF THIS AFTERNOON AND INTO THIS EVENING...WITH VFR CONDITIONS. GUSTY SOUTH TO SOUTHEAST WINDS OF 20 KNOTS SUSTAINED WITH GUSTS TO AROUND 35 KNOTS ARE EXPECTED AT MADISON AND POSSIBLY THE EASTERN SITES THROUGH 19Z TO 20Z THIS AFTERNOON. LEFT GUSTS TO AROUND 20 KNOTS IN THE EASTERN SITES FOR NOW...DUE TO LOW CONFIDENCE WITH THE HIGHER GUSTS THERE. GUSTS SHOULD LOWER BY LATER THIS AFTERNOON. LEFT VFR CONDITIONS GOING THROUGH TONIGHT AND SATURDAY...AS THUNDERSTORM CHANCES LINGER BUT LOW CONFIDENCE IN TIMING AND PLACEMENT OF STORMS. MAY SEE MVFR VISIBILITIES WITH LIGHT FOG AT SITES BETWEEN 09Z AND 14Z SATURDAY. MODEST SOUTH WINDS SHOULD LINGER LATER TONIGHT INTO SATURDAY. WOOD && .PREV DISCUSSION... /ISSUED 308 AM CDT FRI JUN 21 2013/ TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM. THIS WARM...MOIST AND UNSTABLE SOUTHWESTERLY FLOW REGIME IS TYPICALLY DIFFICULT TO RESOLVE DETAILED CONVECTIVE TRENDS BEYOND ABOUT 12HRS. CONVECTION BEYOND 12HRS DEPENDS HIGHLY ON THE BEHAVIOR OF CONVECTION IN THE PRECEDING 12HRS. FOR INSTANCE...ALL THE HI RESOLUTION SHORT RANGE MODELS ARE HAVING DIFFICULTY WITH THE CONVECTION OVER MN EARLY THIS MORNING. EARLIER MODEL RUNS DEVELOPED THIS INTO A BIG BOW ECHO THAT RACED ACROSS THE FORECAST AREA AROUND 12Z. THE REALITY IS THAT IT IS STAYING UP TO THE NORTH MUCH LONGER AND MAY END UP JUST SKIRTING THE NORTHERN FORECAST AREA BEFORE DIMINISHING WITH TYPICAL DIURNAL TRENDS. THE TURN TO THE SOUTHEAST NEEDS THE COLD POOL DYNAMICS TO GET ORGANIZED AND THAT APPEARS TO BE HAPPENING AROUND 07Z THIS MORNING. EACH HRRR RUN HAS BEEN BACKING OFF ON THE SPEED AND OVERALL DEVELOPMENT. THE NOSE OF THE LOW LEVEL JET AND BEST INSTABILITY ARE TO THE WEST AND NORTH...BUT WILL LEAN NORTHEAST INTO THE AREA TODAY. THE MODELS CONTINUE TO BE TOO BULLISH ON SFC MOISTURE. FOR NOW...THERE DOES SEEM TO BE A CONSENSUS THAT WE WILL LIKELY SEE THE MN CONVECTION ROLL ACROSS THE AREA THIS MORNING AS THE LOW LEVEL JET AND MOISTURE LEAN INTO THE AREA. THIS SHOULD LAY OUT A LOW LEVEL BAROCLINIC ZONE THAT COULD BE THE FOCUS FOR MORE CONVECTION LATER THIS AFTERNOON. WE SHOULD SEE ANOTHER MCS DEVELOP OUT IN THE PLAINS THIS AFTERNOON AND ROLL INTO THE CWA LATER TONIGHT. SO LONG STORY SHORT...LOOK FOR MORNING CONVECTION TO DIMINISH THIS AFTERNOON WITH ANOTHER ROUND LATE TONIGHT INTO SATURDAY MORNING. TEMPS MIGHT BE HELD DOWN A BIT TODAY IF WE ARE SLOW TO SCOUR OUT THE MORNING CONVECTIVE DEBRIS. TEMPS WON/T DROP TOO FAR TONIGHT AS WE ARE SOLIDLY IN THE WARM SECTOR. SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH. PRECIP CHANCES CONTINUE TO EXIST EARLY ON THIS PERIOD EVEN THOUGH 500 HPA SHORT WAVE TROUGHS TRAVERSE MAINLY TO OUR NORTH AND WEST. CWA CONTINUES TO LIE UNDER A MID-LEVEL RIDGE WITH SHORT WAVE TROUGHS RIDING THROUGH. THE NOCTURNAL LLJ MAINLY FOCUSES ON SOUTHWEST AND WEST CENTRAL WISCONSIN...PEAKING SATURDAY NIGHT. MODELS DO SHOW LOW-LEVEL WAA AT THIS TIME...BUT WAA MORE PERSISTENT AND STRONGER OUTSIDE THE CWA. FURTHER...ALTHOUGH SOME SYNOPTIC LIFT WILL BE PRESENT IN THE PERIOD...THE THERMODYNAMIC ENVIRONMENT WILL NOT BE THAT PRIMED. BUFKIT SOUNDINGS AND LOW-LEVEL THERMO ENVIRONMENT SHOW A CAPPED ENVIRONMENT COINCIDING WITH LOW-LEVEL THERMAL RIDGE. THIS COULD POTENTIALLY LIMIT OUR THUNDER CHANCES THIS WEEKEND. OTHERWISE...AMPLE MEAN LAYER INSTABILITY IN THE PERIOD WILL COMBINE WITH SUFFICIENT MOISTURE...ESPECIALLY CONSIDERING SFC DEW POINTS FCST IN THE UPPER 60S TO AROUND 70 DURING THE DAY SAT AND SUN. SHEAR WILL BE A LIMITING FACTOR THOUGH FOR ANY ORGANIZED DEVELOPMENT IN THE PERIOD. DEEP LAYER 0-6KM SHEAR IS ONLY AROUND 15-25 KTS. THIS SUGGEST ORDINARY THUNDERSTORMS AND SOME MULTICELL ORGANIZATION TYPE STORM MODES. SATURDAY IS EXPECTED TO GIVE THE CWA THE BEST CHANCE FOR CONVECTION GIVEN THE BETTER INSTABILITY AND PROXIMITY OF THE EFFECTIVE BOUNDARY. THOUGH GIVEN THE AFOREMENTIONED CAP AND THE UNCERTAIN POSITION OF THE BOUNDARY...CONTINUED WITH CHANCES ON SATURDAY. WARM AND ABOVE NORMAL HIGHS EXPECTED SATURDAY AND SUNDAY. MODEL CONSENSUS OF 925 HPA TEMPS ARE AROUND 25-27 C SAT AND 24-26 C SUN THAT CORRESPOND TO 89-93 F AND 87-91 F...RESPECTIVELY. NOTE...WILL HAVE TO WATCH APPARENT TEMPS/HEAT INDEX VALUES SUNDAY GIVEN THE MOIST SFC DEW POINTS IN THE UPPER 60S/AROUND 70 AND SFC HIGHS AROUND 90 IN PORTIONS OF THE CWA...AS HEAT INDEX VALUES REACH LOW AND MID 90S SAT AND WELL INTO THE MID AND UPPER 90S SUN. POTENTIAL RISK OF HEAT INDEX VALUES FURTHER SUBSTANTIATED BY LOOKING AT CIPS IMPACT BASED GUIDANCES PROBABILITY OF SFC HEAT INDEX VALUES EXCEEDING 95 F THAT HAS HIGH PROBS IN SOUTH CENTRAL AND SOUTHEAST WI. MONDAY THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE MEDIUM. PERIOD CHARACTERIZED GENERALLY BY A MID-LEVEL ZONAL FLOW...THAT BREAKS DOWN LATE THURSDAY INTO FRIDAY AS A MORE AMPLIFIED PATTERN TAKES OVER. THE LATTER SHARED BY BOTH THE GFS AND ECMWF. VARIOUS S/W TROUGHS MOVE THROUGH THOUGH DIFFERENCES BETWEEN FEATURES AND TIMING MAKE FCST UNCERTAIN. THE GENERAL SW FLOW AND THERMAL ENVIRONMENT THOUGH SHOULD KEEP READINGS NEAR OR ABOVE THEIR SEASONAL NORMAL VALUES. SEASONAL NORMAL VALUES THIS TIME OF THE YEAR ARE USUALLY AROUND 81-82 TO 78-79 WEST TO EAST ACROSS THE CWA. BY THURSDAY INTO FRIDAY WITH A LONG WAVE TROUGH DIGGING INTO THE GREAT LAKES REGION...FLOW BECOMES MORE OUT OF THE NW-N AND HIGH TEMPERATURES BEGIN TRENDING DOWNWARD. AVIATION/12Z TAFS/...MAIN AVIATION CONCERN DURING THE PERIOD IS TIMING OF ANY CONVECTION...AND THAT WILL BE CHALLENGING. OVERALL...CONDITIONS SHOULD BE VFR. THE EXCEPTION WILL BE IN AND AROUND ANY THUNDERSTORMS WHERE VSBY AND CIGS COULD BRIEFLY DROP TO MVFR LEVELS. WE SHOULD SEE STORMS MOVE THROUGH THE AREA THIS MORNING...AS THE REMNANTS OF STORMS UP TO OUR NORTHWEST EARLY THIS MORNING ROLL SOUTHEAST THROUGH THE AREA. THERE SHOULD BE A BREAK IN THE ACTIVITY THIS AFTERNOON...BUT CAN/T RULE OUT NEW DEVELOPMENT ALONG ANY REMNANT OUTFLOW/BAROCLINIC BOUNDARIES DURING THE HEAT OF THE AFTERNOON. THE NEXT BEST CHANCE FOR STORMS WOULD BE LATER TONIGHT AS ANOTHER LARGE COMPLEX OF STORMS THAT DEVELOPS UPSTREAM EARLIER IN THE AFTERNOON ROLLS IN. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...CRAVEN/WOOD TODAY/TONIGHT AND AVIATION/MARINE...DAVIS SATURDAY THROUGH THURSDAY...ET
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
220 PM MDT FRI JUN 21 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 300 PM MDT FRI JUN 21 2013 BELIEVE WE ARE PRIMED FOR A SEVERE WEATHER EPISODE THIS AFTERNOON. CONDITIONS ARE SET FOR SEVERE THUNDERSTORMS. CHALLENGES ARE WHERE AND WHEN. CURRENTLY...STRATUS LAYER ON VISIBLE IMAGERY CONTINUES TO ERODE ACROSS DAWES AND SIOUX COUNTIES IN THE PANHANDLE AND NIOBRARA COUNTY IN EAST CENTRAL WYOMING. DEWPOINTS REMAIN EXTREMELY HIGH (FOR OUR NECK OF THE WOODS)...IN THE PANHANDLE. ALLIANCE STILL REPORTING A DEW POINT OF 67 DEGREES...WITH LOW TO MID 60S ELSEWHERE. LATEST STORM PREDICTION CENTER MESOANALYSIS SHOWING CAPE ALREADY IN MOST OF THE PANHANDLE OF 4500 TO 5000 J/KG. ALL THAT IS NEEDED IS A LIFTING MECHANISM AND THAT IS DEVELOPING. A DRY LINE LAYS ACROSS EXTREME SOUTHEASTERN WYOMING...ROUGHLY FROM JUST EAST OF CHEYENNE TO JUST WEST OF TORRINGTON AND THEN NORTHWEST TO DOUGLAS. BEHIND THIS LINE...DEWPOINTS HAVE FALLEN INTO THE 20S. ALONG THIS LINE...SEEING CU DEVELOPING ALONG THE LINE. HAVE A PRETTY GOOD CELL ALREADY DEVELOPING IN NORTHERN LARAMIE COUNTY AND SOUTHERN GOSHEN COUNTY. THIS IS MOST LIKELY THE START OF OUR EVENT. JUST RECEIVED A SWOMCD FROM SPC AT 113 PM STATING A WATCH IS LIKELY...SO ANOTHER HOUR OR SO...CONVECTION SHOULD INITIATE. LATEST HRRR COMPOSITE REFLECTIVITY FORECAST SHOWING THAT CELL IN SOUTHERN GOSHEN COUNTY TAKING OFF AROUND 3 PM. BY THAT TIME...LOW STRATUS SHOULD BE MIXED OUT OVER THE NORTHERN PANHANDLE. SUPER CELL THEN MOVES EAST INTO THE CENTRAL PANHANDLE. WITH SUCH LARGE CAPE...GOING TO SEE SOME VERY LARGE HAIL REPORTS. NAM/WRF FORECAST SOUNDINGS CONTINUE TO SHOW STRONGLY VEERING WINDS WITH NORTHEASTERLY TO EASTERLY SURFACE WINDS AND 35-40KT SOUTHWESTERLY WINDS AT 700MBS. MORE THAN ENOUGH SHEAR TO SUPPORT SUPERCELLS CONTINUING INTO THE PANHANDLE. LATEST NAM HELICITIES FOR LATER THIS AFTERNOON/EVENING SHOWING 150M2/S2...INCREASING TO OVER 300M2/S2 OVER CONVERSE AND NIOBRARA COUNTIES AFTER 00Z...SPREADING INTO THE NORTHERN PANHANDLE AFTERWARDS. LCLS QUITE LOW UP THERE AS WELL...SO THE TORNADO THREAT WILL LIKELY BE FROM 23Z THROUGH MAYBE 02 TO 03Z TIME FRAME. SEVERE THUNDERSTORMS COULD LAST WELL INTO THE EVENING AND OVERNIGHT HOURS IN THE PANHANDLE. FOR SATURDAY...PRETTY MUCH A REPEAT OF TODAY WITH SEVERE THUNDERSTORMS OVER EAST CENTRAL WYOMING AND NEBRASKA PANHANDLE. SHOULD BEGIN TO SEE A DECREASE IN LOW LEVEL MOISTURE SUNDAY AS WINDS SHIFT TO THE SOUTHWEST. COULD STILL SEE SOME SEVERE THUNDERSTORMS IN THE PANHANDLE SUNDAY AFTERNOON. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 300 PM MDT FRI JUN 21 2013 DUE TO THE THREAT OF SEVERE WEATHER THIS AFTERNOON...WILL KEEP LONG TERM DISCUSSION BRIEF SINCE NOT MUCH HAS CHANGED SINCE YESTERDAY. MODELS CONTINUING TO SHOW SOUTHWEST FLOW ALOFT AND RELATIVELY QUIET WEATHER FOR NEXT WEEK. THERE APPEARS TO BE LITTLE IN THE WAY OF RAINFALL CHANCES ACROSS SOUTHEAST WYOMING NEXT WEEK...WITH A SLIGHTLY BETTER CHANCE ACROSS WESTERN NEBRASKA ON MONDAY AHEAD OF A WEAK COOL FRONT. MODELS SHOW THIS PACIFIC FRONT SLIDING EASTWARD ACROSS THE NORTHERN ROCKIES MONDAY NIGHT AND INTO TUESDAY. THE GFS AND THE GEM HAVE TRENDED TOWARDS THE ECMWF SOLUTION...SHOWING THE FRONT STALLING FURTHER TO THE NORTH AS THE UPPER LEVEL TROUGH IS FURTHER NORTH AS WELL AND MORE PROGRESSIVE. THE MAIN IMPACT FROM THIS FRONT WILL BE WINDY CONDITIONS...MAINLY WEST OF THE LARAMIE RANGE ON MONDAY AND TUESDAY. TEMPERATURES WILL NOT LOWER MUCH...IF AT ALL...ESPECIALLY FURTHER SOUTH NEAR THE I80 CORRIDOR. THERE APPEARS TO BE A BETTER CHANCE OF TSTORMS AHEAD OF THIS FRONT ON MONDAY...AS A WEAK SHORTWAVE MOVES NORTHEAST ACROSS THE HIGH PLAINS. INCREASED POP MONDAY AND MONDAY EVENING MAINLY ACROSS WESTERN NEBRASKA. AFTER THAT...MODELS ALL INDICATE A STRONG UPPER LEVEL HIGH DEVELOPING AND INTENSIFYING NEAR THE FOUR CORNERS REGION BY WEDNESDAY AND THURSDAY. THIS WILL RESULT IN A PERIOD OF LIGHT WINDS BUT ALSO VERY WARM OR HOT TEMPERATURES THROUGH LATE NEXT WEEK. WITH THE EXCEPTION OF MONDAY...KEPT POP BELOW 10 PERCENT THROUGH THE WEEK. HIGH TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL AND GENERALLY IN THE 80S AND 90S. THIS UPPER LEVEL HIGH WILL BEGIN TO DRIFT WESTWARD BY LATE IN THE WEEK...ALLOWING A CANADIAN COLD FRONT TO PUSH SOUTH. THIS MAY INCREASE PRECIPITATION AND TSTORM CHANCES BY NEXT WEEKEND DUE FAVORABLE EASTERLY FLOW BEHIND THE BOUNDARY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING) ISSUED AT 1139 AM MDT FRI JUN 21 2013 LOW CIGS WILL LINGER THROUGH 21Z OVER PORTIONS OF THE NEBRASKA PANHANDLE WESTWARD INTO EAST CENTRAL WYOMING. OTHERWISE...VFR CONDITIONS ARE EXPECTED ALONG THE I80 CORRIDOR FROM RAWLINS TO SIDNEY NEBRASKA UNTIL LATE THIS AFTERNOON. THUNDERSTORMS...SOME SEVERE...WILL DEVELOP ALONG THE NEBRASKA/WYOMING STATE LINE AROUND 21Z AND MOVE NORTHEAST THROUGH THIS EVENING. ERRATIC GUSTY WINDS UP TO 50 MPH...HAIL...AND IFR CONDITIONS ARE POSSIBLE WITH THESE THUNDERSTORMS EAST OF A LINE FROM KIMBALL NEBRASKA TO LUSK WYOMING...INCLUDING KCDR...KSNY...KBFF...AND KAIA. THUNDERSTORMS WILL LINGER THROUGH LATE TONIGHT BEFORE PUSHING EAST OF THE AREA BY MIDNIGHT. IFR CONDITIONS IN LOW CIGS AND FOG ARE EXPECTED TO RETURN AFTER MIDNIGHT ACROSS THE HIGH PLAINS OF WESTERN NEBRASKA AND PORTIONS OF SOUTHEAST WYOMING. && .FIRE WEATHER... ISSUED AT 300 PM MDT FRI JUN 21 2013 DRY AND BREEZY CONDITIONS CONTINUE ALONG AND WEST OF THE LARAMIE RANGE THIS AFTERNOON. TO THE EAST IN THE PANHANDLE AND UP OVER NIOBRARA COUNTY...HIGH HUMIDITIES WILL LEAD TO SEVERE THUNDERSTORMS LATER THIS AFTERNOON AND EVENING. HUMIDITIES OUT WEST ONCE AGAIN IN THE SINGLE DIGITS WITH WIND GUSTS FROM THE SOUTHWEST AT 30 TO 35 MPH. WINDS WILL EASE AFTER SUNSET. CONDITIONS LOOK TO REPEAT FOR SATURDAY AND TO A LESSER EXTENT ON SUNDAY AFTERNOON. STRONG WINDS WILL CONTINUE NEXT WEEK...PARTICULARLY MONDAY NIGHT INTO TUESDAY WITH WIND GUSTS EXCEEDING 40 MPH POSSIBLE OUT WEST. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...CLAYCOMB LONG TERM...TJT AVIATION...TJT FIRE WEATHER...CLAYCOMB