Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/31/14


SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NWS LOS ANGELES/OXNARD CA
505 PM PDT FRI MAY 30 2014 ...UPDATED AVIATION AND MARINE DISCUSSIONS... .SYNOPSIS... A COUPLE OF LOW PRESSURE SYSTEMS WILL MOVE OVER THE REGION THROUGH NEXT WEEK WITH NIGHT TO MORNING LOW CLOUDS AND FOG...THEN THE AFTERNOONS WILL HAVE FAIR SKIES FOR INLAND AREAS AND SOME CLEARING AT THE COAST. THERE WILL BE BREEZY WINDS IN THE MOUNTAINS AND DESERTS OVER THE WEEKEND. THE TEMPERATURES WILL BE NEAR NORMAL THROUGHOUT THE FORECAST PERIOD. && .SHORT TERM (TONIGHT-MONDAY)... SOUTHWEST FLOW ALOFT CONTINUES ACROSS THE AREA FROM A TROUGH OF LOW PRESSURE OVER THE NORTH COAST OF CALIFORNIA...AND A RIDGE OF HIGH PRESSURE OVER THE UPPER PLAINS STATES. AT THE SURFACE...ONSHORE FLOW WILL REMAIN IN PLACE THROUGH THE WEEKEND KEEPING TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS. A WIND ADVISORY WAS ADDED FOR THE SANTA BARBARA SOUTH COAST AND MOUNTAINS THIS EVENING AS NAM-WRF SOLUTIONS SUGGESTS SURFACE PRESSURE GRADIENTS TIGHTENING LATER TONIGHT. GRADIENTS ACROSS SANTA BARBARA COUNTY THIS AFTERNOON ARE TIGHTENING...WITH KSBA- KSMX SURFACE PRESSURE GRADIENTS AT -2.2 MB THIS AFTERNOON. IF SURFACE TRENDS CONTINUE...A KSBA-KSMX SURFACE GRADIENT AROUND 4 MB CAN BE EXPECTED BETWEEN 7 PM AND 10 PM THIS EVENING. IN ADDITION...NAM-WRF SOLUTIONS SUGGEST 20 TO 25 KNOTS BETWEEN GAVIOTA AND GOLETA...AND 3-KM HRRR SOLUTIONS INDICATE 20 TO 30 KNOTS AT THE SURFACE BETWEEN GOLETA AND GAVIOTA. OTHERWISE...INCREASING SOUTHWEST FLOW ALOFT SHOULD OCCUR OVER THE WEEKEND AS A SERIES OF TROUGHS OF LOW PRESSURE APPROACH THE AREA. THE MARINE LAYER SHOULD DEEPEN AND INCREASE ONSHORE FLOW OVER THE WEEKEND...WITH THE BEST COOLING OCCURRING ALONG THE CENTRAL COAST. NO RAIN OR DRIZZLE IS EXPECTED AT THIS TIME WITH THE TROUGH...BUT THERE IS A TIME PERIOD ON MONDAY WHERE THE MOUNTAINS MAY HAVE SOME CLOUDINESS AS A DIFFLUENT FLOW PATTERN DEVELOPS. IF THE MODELS CHANGE COURSE SOMEWHAT AND PROVIDE SOME MOISTURE...THERE COULD BE A THREAT OF MOUNTAIN SHOWERS ON MONDAY AFTERNOON AND EVENING. .LONG TERM (TUESDAY-FRIDAY)... SOUTHWEST FLOW ALOFT SHOULD PERSIST INTO NEXT WEEK KEEPING A PERSISTENT MARINE LAYER IN PLACE AND TEMPERATURES NEAR NORMAL. SOME DEEPENING OFF THE MARINE AND A COOLING TREND COULD DEVELOP FOR THE LATTER HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE APPROACHES THE AREA. && .AVIATION...30/2350Z...GENERALLY HI CONFIDENCE IN THE 00Z TAFS. VFR CONDITIONS ARE EXPECTED FOR THE MOST PART THRU SAT AT KPRB...KSBA... KBUR...KVNY...KPMD AND KWJF. FOR KSBP...KSMX...KOXR...KLAX AND KLGB...THERE IS GENERALLY HI CONFIDENCE OVERALL THAT LOW CLOUDS AND IFR/MVFR CONDITIONS WILL DEVELOP LATER TONIGHT. THE LOW CLOUDS WILL CLEAR TO VFR BY LATE SAT MORNING AND CONTINUE THRU THE AFTERNOON. GUSTY SW WINDS AT KPMD AND KWJF WILL LINGER THIS EVENING THEN DIMINISH OVERNIGHT BEFORE INCREASING AGAIN BY SAT AFTERNOON. THERE WILL ALSO BE GUSTY NW WINDS AT KSBP THROUGH EARLY THIS EVENING. KLAX...GENERALLY HI CONFIDENCE OVERALL IN THE 00Z TAF WITH LOW CLOUDS AND MVFR CONDITIONS EXPECTED TO MOVE INTO THE AIRFIELD BY 10Z THEN PERSIST THRU ABOUT 17Z SAT. THERE IS A 50 PERCENT CHANCE THE LOW CLOUDS COULD BE INTERMITTENT AT TIMES. OTHERWISE...VFR CONDITIONS CAN BE EXPECTED THRU SAT EVENING. KBUR...GENERALLY HI CONFIDENCE OVERALL IN THE 00Z TAF. THERE IS A 30 PERCENT CHANCE OF LOW CLOUDS AND IFR/MVFR CIGS LATE TONIGHT INTO SAT MORNING. OTHERWISE...VFR CONDITIONS ARE EXPECTED THRU SAT AFTERNOON...EXCEPT FOR A 60 PERCENT CHANCE OF MVFR VSBYS 14Z-18Z. && .MARINE...30/300 PM. GOOD CONFIDENCE IN NORTHWEST WINDS AT SCA LEVEL OVER THE OUTER WATERS THROUGH LATE TONIGHT...ALTHO MODERATE WINDS 10 TO 20 KNOTS ARE LIKELY TO PERSIST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. FOR THE INNER WATERS INCLUDING POINT PIEDRAS BLANCAS TO POINT SAL OUT TO 10 NM...WINDS UP TO 20 KNOTS WITH LOCAL GUSTS TO 25 KNOTS ARE EXPECTED N OF POINT CONCEPTION AND ACROSS THE SANTA BARBARA CHANNEL EACH LATE AFTERNOON AND EVENING THROUGH SAT...OTHERWISE MAINLY LIGHT WINDS ARE EXPECTED FOR PZZ645/650/655. && .LOX WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY (SEE LAXMWWLOX). && $$ PUBLIC...HALL AVIATION...SIRARD MARINE...SIRARD SYNOPSIS...SETO/HALL WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS EUREKA CA
402 PM PDT FRI MAY 30 2014 .SYNOPSIS...THERE WILL BE AFTERNOON CLOUDS OVER THE MOUNTAINS THROUGH THE WEEKEND WITH A SLIGHT CHANCE OF THUNDERSTORMS ON SUNDAY AS A TROUGH MOVES OVER THE AREA. TEMPERATURES WILL REMAIN MILD WITH LOW CLOUDS AND DRIZZLE IMPACTING THE COAST AND COASTAL VALLEYS EACH NIGHT AND MORNING. && .DISCUSSION...WATER VAPORY IMAGERY SHOWS A TROUGH OVER THE AREA BUT MORNING MEDFORD SOUNDING SHOWED A COUPLE OF INVERSIONS CAPPING THE UPWARD MOTION. THIS IS THE REASON THAT ONLY CU HAS DEVELOPED OVER THE SOUTH FORK MTN RANGE THIS AFTERNOON. HRRR SHOWED A SIMULATED SHOWER OVER THE YOLLA BOLLY AREA BRIEFLY ABOUT 5 PM THIS AFTERNOON AND THAT WILL BE THE ONLY IMPACT WITH THE TROUGH. THE TROUGH WILL EJECT OUT TONIGHT WITH A DRIER NORTHWEST FLOW FOR SATURDAY. ONLY A FEW CU EXPECTED IN THE AFTERNOON. BY SUNDAY, ANOTHER TROUGH WILL MOVE DOWN FROM THE NORTHWEST INCREASING THE INSTABILITY AND SPC HAS US IN A GENERAL THUNDERSTORM OUTLOOK. THIS TROUGH DROPS SOUTH AND DEVELOPS INTO A CLOSED LOW OFF THE SOUTHERN CA COAST SUNDAY NIGHT. MODELS STRUGGLING WITH HOW TO EJECT THIS LOW AS IT COMBINES WITH ANOTHER LOW COMING DOWN FROM THE NORTHWEST ON MONDAY. ALL SOLUTIONS HAVE SOME KIND OF LOW OVER AREA MONDAY INTO WEDNESDAY THOUGH EXACT DETAILS VARY. AIRMASS WILL CONTINUE UNSTABLE SO CONTIUED THREAT OF THUNDERSTORMS OVER THE HIGHER TERRAIN. MODELS EJECT LOW BY THE END OF THE WEEK AND LEFT OUT MENTION OF SHOWERS OR TSTMS THOUGH IT LOOKS LIKE THEY HAVE ANOTHER TROUGH BY NEXT FRIDAY. CLOSER TO THE COAST, THE MARINE LAYER IS BECOMING ENTRENCHED AS THESE TROUGHS ARE NOT COLD ENOUGH TO BREAK UP THE MARINE INVERSION. CONTINUED NIGHT AND MORNING STRATUS ALONG THE COAST AND UP THE EEL RIVER AND KLAMATH RIVER VALLEYS WITH CLEARING IN THE AFTERNOONS WITH SOME DRIZZLE POSSIBLE AT THE IMMEDIATE COAST. INLAND TEMPS WILL REMAIN ABOUT 5-10 DEGREES ABOVE NORMAL IN THE MID 80S TO LOW 90S. DEAN && .AVIATION...CIGS CONTINUED TO EXTEND ALONG MUCH OF THE REDWOOD COAST TIL AROUND NOON. A COUPLE OF EARLIER MORNING PIREPS HAD CIGS AROUND 010-012 WITH TOPS AROUND 017-020. ASOS`S RECORDED CIGS AS LOW AS 080-010 AND THEN AROUND 011-013 ABOUT NOONTIME. LOW CLOUDS AT CEC STAYED IN LONGER THAN EXPECTED DUE TO A NICE SOUTHERLY WIND. BY EARLY AFTERNOON LOW CLOUDS HAD MOSTLY ERODED EXCEPT A NARROW SWATHE AT THE COAST. PERSISTENCE AND GUIDANCE RETURNS MVFR-IFR CIGS TO THE COAST BY LATE AFTERNOON INTO EARLY EVENING. A LITTLE BIT OF A GRADIENT AT THE COAST WILL INCREASE WINDS THIS AFTERNOON. OVER THE INTERIOR: SOME CONVECTIVE CLOUDS OVER THE MOUNTAINS THIS AFTERNOON AS AN UPPER LEVEL TROUGH WILL MORE-SO AFFECT MOUNTAINOUS REGIONS. THIS MIGHT JUST BE THE CATALYST FOR A SLIGHT CHANCE OF A SHOWER OR TWO WITH A WEAK THREAT OF A THUNDERSTORM OVER THE YOLLA BOLLAS. OTHERWISE...MOSTLY CLEAR. TA && .MARINE...IT LOOKS LIKE THE FORECAST IS ON TRACK WITH A HAZARDOUS SEAS WARNING ACROSS THE OUTER WATERS AND SMALL CRAFT ADVISORY ALONG THE INNER COASTAL WATERS. NORTHERLY WINDS AND SEAS WILL CONTINUE OVERNIGHT AS PACIFIC HIGH PRESSURE AND THE CALIFORNIA THERMAL TROUGH INTERACT WITH ONE ANOTHER AND MAINTAIN A STRONGER PRESSURE GRADIENT. THIS SURFACE PATTERN WILL CONTINUE THROUGH NEXT WEEK RESULTING IN STRONG AND PERSISTENT NORTHERLY WINDS AND STEEP HAZARDOUS SEAS BEYOND 10 NAUTICAL MILES. MULTIPLE SHORTWAVES TRAVERSING THE REGION OVER THE NEXT SEVERAL DAYS WILL CAUSE FLUCTUATIONS WITHIN THE INSTABILITY OF THE ATMOSPHERE. THESE FLUCTUATIONS WILL RESULT IN MARGINAL GALE FORCE WINDS ACROSS THE COASTAL WATERS. NEVER THE LESS, CONFIDENCE STILL REMAINS HIGH THAT STRONG WINDS WILL PERSIST AND THE SEA STATE WILL REMAIN STEEP THROUGH NEXT WEEK. AS A RESULT, THE HAZARDOUS SEAS WARNING WAS EXTENDED THROUGH SATURDAY NIGHT. FURTHER EXTENSIONS OF THE CURRENT PRODUCTS WILL LIKELY BE NEEDED, OR POSSIBLY UPGRADED. EITHER WAY, CONTINUED MONITORING OF THE MARINE STATE WILL BE NECESSARY IN DETERMINING WHETHER PRODUCT ADJUSTMENTS ARE NEEDED.KML && .EKA WATCHES/WARNINGS/ADVISORIES... CA...NONE. NORTHWEST CALIFORNIA COASTAL WATERS... SMALL CRAFT ADVISORY UNTIL 3 AM PDT SATURDAY PZZ450-455. GALE WARNING UNTIL 3 PM PDT THIS AFTERNOON PZZ470. HAZARDOUS SEAS WARNING UNTIL 3 AM PDT SUNDAY PZZ470. HAZARDOUS SEAS WARNING UNTIL 3 AM PDT SUNDAY PZZ475. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
918 PM MDT FRI MAY 30 2014 .UPDATE... ISSUED AT 910 PM MDT FRI MAY 30 2014 LATEST HRRR AND TO SOME EXTENT THE 00Z NAM HINTING AT ANOTHER WIGGLE IN THE FLOW SPARKING A FEW MORE NOCTURNAL STORMS BETWEEN 10 PM AND 3 AM TONIGHT. FROM THE CANYONLANDS NORTHEAST INTO THE NORTHERN MOUNTAINS. HAVE MODIFIED OVERNIGHT POP FIELDS TO FIT THIS POSSIBILITY. CURRENT CONVECTION ACROSS THE REGION WAS WELL HANDLED BY EARLIER RUNS...SO LITTLE REASON TO DEVIATE. UPDATES OUT SHORTLY. && .SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT) ISSUED AT 320 PM MDT FRI MAY 30 2014 A PASSING DISTURBANCE WAS LIFTING THROUGH THE PARK RANGE THIS AFTERNOON AND EXITING THE FORECAST AREA. IN ITS WAKE TEMPERATURES HAVE REBOUNDED WHILE MOISTURE REMAINS DEEP FOR LATE MAY...AROUND 0.75 INCHES OF PRECIPITABLE WATER. STORMS HAVE FORMED FIRST OVER THE AREA MTNS AND ARE MOVING E-NE AT AROUND 15 MPH. THE 12Z AND 18Z MODELS SHOW SOME LINGERING CONVECTION OVERNIGHT MAINLY ACROSS THE NORTH WHERE SOME MINOR INSTABILITY EXITS. AHEAD OF AN APPROACHING TROUGH...AN 80KT JET NOSES IN FROM THE SW. SATURDAY AND SATURDAY NIGHT. THIS APPEARS TO PRODUCE SOME WEAK DYNAMICAL SUPPORT SEEN IN THE UPPER DIVERGENT AND DEFORMATION FIELDS OVER THE NORTHERN FORECAST AREA. THERE IS NO SURFACE REFLECTION. PRECIP WATER REMAINS IN THE 0.5 TO 0.75 INCH RANGE. SO LOCALLY HEAVY SHOWERS WILL AGAIN BE POSSIBLE FAVORING THE MTNS AND ADJACENT VALLEYS. SOME NOCTURNAL STORMS ARE EXPECTED SATURDAY NIGHT. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 320 PM MDT FRI MAY 30 2014 LOW PRESSURE ENERGY WILL MOVE ALONG THE MT/CANADIAN BORDER ON SUNDAY...WITH HIGH PRESSURE BUILDING TO OUR SOUTH-SOUTHWEST. THIS AREA OF HIGH PRESSURE WILL HAVE EFFECTIVELY CLOSED THE TAP OF SUB TROPICAL MOISTURE...WITH MUCH DRIER AIR MOVING IN ON THE SOUTHWEST THEN WESTERLY FLOW. THE FLOW BECOMES MORE SOUTHWEST AGAIN BY TUE AS THE SOUTHERN HIGH STRETCHES OUT TO THE NORTHEAST...AND ANOTHER WAVE REINFORCES THE WESTERN TROUGH. THEREFORE A WARMING AND DRYING TREND WILL CONTINUE THROUGH THE EARLY WORK WEEK. BOTH THE GFS AND ECMWF NOW AGREE THAT A SHORTWAVE WILL APPROACH ON TUE AND MAY RESULT IN INCREASED WINDS. THIS MAY BE OF CONCERN TO LAND USE AGENCIES AS HUMIDITIES ARE ALSO EXPECTED TO BE VERY LOW SINCE THIS WAVE CARRIES NO ADDITIONAL MOISTURE. BEYOND MIDWEEK MODEL AGREEMENT DIMINISHES WITH ADDITIONAL WAVES BRUSHING THE FORECAST AREA. AT THIS TIME THESE WAVES GENERALLY LOOK ON THE DRY SIDE. TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 910 PM MDT FRI MAY 30 2014 ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT AREAS ALONG AND NORTH OF INTERSTATE 70 THROUGH 12Z SATURDAY MORNING. GUSTY OUTFLOW WINDS...LIGHTNING AND BRIEF HEAVY RAIN WILL ACCOMPANY THE STRONGER STORMS. MOUNTAINS MAY BE BRIEFLY OBSCURED AS THE ACTIVITY ROLLS THROUGH. EXPECT DRY CONDITIONS BETWEEN 12Z AND 18Z SATURDAY...WITH A NEW ROUNDS OF STORMS DEVELOPING SATURDAY AFTERNOON. && .HYDROLOGY... ISSUED AT 320 PM MDT FRI MAY 30 2014 FLOWS IN MANY RIVERS AND STREAMS WILL REMAIN HIGH OR INCREASE THROUGH EARLY NEXT WEEK AS THE SNOW PACK CONTINUES TO MELT DUE TO CONTINUED WARM TEMPERATURES. IN ADDITION...SCATTERED SHOWERS THROUGH SATURDAY AFTERNOON...COULD CAUSE ADDITIONAL FLOW INCREASES. THE HIGHEST FLOWS ARE OCCURRING IN RIVERS AND STREAMS FROM THE GUNNISON BASIN IN WEST-CENTRAL COLORADO NORTHWARD TO THE WYOMING BORDER...AND ACROSS NORTHEAST UTAH. HOWEVER ALL RIVERS AND STREAMS ACROSS WESTERN COLORADO AND EASTERN UTAH WILL BE RUNNING FAST...STRONG AND DEEP THROUGH THE REST OF THE WEEK AND INTO NEXT WEEK. VARIOUS FLOOD PRODUCTS REMAIN IN EFFECT FOR THESE CONDITIONS. PAY ATTENTION TO RIVER...CREEK AND STREAM LEVELS...AND WATCH FOR DEBRIS BUILDUP. PLEASE USE CAUTION IF YOU PLAN ON BOATING DOWN...OR RECREATING NEAR ANY RIVERS OR STREAMS THROUGH EARLY NEXT WEEK. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...JDC SHORT TERM...JOE LONG TERM...EH AVIATION...JDC HYDROLOGY...EH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1049 AM MDT THU MAY 29 2014 ...CORRECTED HYDRO SECTION... .UPDATE... ISSUED AT 1049 AM MDT THU MAY 29 2014 TEMPERATURES OVER THE EASTERN PLAINS ARE WARMER THAN FORECAST AS THE SOUTHERLY WINDS HAVE BEEN INCREASING EARLY TODAY. HAVE ADJUSTED THOSE TEMPERATURES. WEAK ECHOES OVER THE MOUNTAINS HAVE BEEN APPEARING ON RADAR AS MORE SUN DUE TO LESS HIGH CLOUD COVER THAN ORIGINALLY THOUGHT HAS OCCURRED. HAVE MOVED UP CHANCES OF PRECIPITATION ACROSS THE MOUNTAINS AND URBAN CORRIDOR A COUPLE HOURS. NEW NAM AND HIGH RES RUC AND HRRR ARE SHOWING A PATTERN OF AFTERNOON CONVECTION INCREASING WITH A SURGE OF MOISTURE MOVING UP LATE THIS AFTERNOON FROM THE SOUTH PARK AREA....THEN ANOTHER WAVE MOVING UP AROUND MIDNIGHT. WITH PRECIPITABLE WATER VALUES ALREADY ABOUT 0.2 UP FROM YESTERDAY AND THE EXPECTED SLOW MOVING STORM MOTIONS TO THE NORTHEAST...WILL KEEP AN EYE ON DEVELOPMENT AND POTENTIAL FOR LOCALLY HEAVY RAIN. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 246 AM MDT THU MAY 29 2014 HIGH LEVEL MOISTURE HAS BEEN SLOW TO SPREAD EASTWARD AS THE RIDGE AXIS IS STILL OVER EASTERN COLORADO. NAM IS THE OUTLIER IN BRINGING THIS EASTWARD MORE QUICKLY...PREFER THE GFS AND OTHER MODELS WHICH HOLD THE HIGHER LEVEL OVER THE MOUNTAINS TODAY BUT THEN SPREAD CONVECTION EASTWARD OVERNIGHT. EXPECT THE PLAINS TO BE CAPPED...BUT SHOWERS AND STORMS OVER THE MOUNTAINS WILL SPREAD EASTWARD IN THE LATE AFTERNOON AND EVENING. END RESULT IS JUST TO SLOW EVERYTHING DOWN A FEW HOURS. CAPES ARE STILL PRETTY LOW...300-600 J/KG SO I THINK FOR THE AFTERNOON STORMS WILL MAINLY BE WEAK...SOME BRIEF HEAVY RAIN POSSIBLE WITH THE STRONGER CELLS. WITH SOUTHERLY WINDS AT ALL LEVELS...EXPECT CELLS TO MOVE ALONG WELL ENOUGH. SOME POTENTIAL FOR SOME SLOWING AS STORMS GET ONTO THE PLAINS THIS EVENING DUE TO THE STRONGER LOW LEVEL WINDS CAUSING SOUTHWARD DEVELOPMENT...BUT I DO NOT EXPECT THIS TO BE STRONG ENOUGH FOR TRAINING OR STATIONARY STORMS. IN ADDITION THE AVAILABLE MOISTURE IS NOT THAT GREAT ANYWAY. HIGHS ON THE PLAINS MAY NEED TO BE SLIGHTLY WARMER IF THE CLOUDS ARE DELAYED...BUT LEFT THEM ALONE SINCE THERE SEEMS A DECENT CHANCE OF GETTING SOME CLOUDS SPREADING OFF THE MOUNTAINS BY MID AFTERNOON. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 246 AM MDT THU MAY 29 2014 ON FRIDAY...A MOIST AND UNSTABLE AIRMASS WILL BE OVER THE REGION WITH THE UPPER LEVEL RIDGE AXIS SHIFTED TO THE EAST. PRECIPITABLE WATER VALUES ARE PROGGED TO BE AROUND 0.80 INCHES IN DENVER...WITH CAPES AROUND 400 J/KG EARLY FRIDAY AFTN. TOWARDS AKRON...THE PW VALUES CLIMB TO AROUND 1.1 INCHES WITH SFC BASED CAPES CLOSE TO 1500 J/KG. A FRONTAL BOUNDARY IS PROGGED TO SLIP INTO THE NORTHEASTERN PLAINS IN THE AFTN. THE FRONT MAY ACT AS A TRIGGER FOR THE DEVELOPMENT OF THE STORMS...BUT IF IT STABILIZES TOO FAST BEHIND THE FRONT THE STORMS MAY NOT LAST VERY LONG OVER THE PLAINS IN SPITE OF THE MUCH HIGHER CAPE. THERE IS SOME CIN OF AROUND -80 J/KG SO CAP COULD PREVENT DEEP CONVECTION BEHIND THE FRONT. THE MAIN AREA OF CONCERN WILL BE WHERE THE FRONT SETTLES ALONG THE FRONT RANGE. INCREASING LOW LEVEL MOISTURE FM THE EAST WILL ELEVATE THE CAPE AND COULD ALSO PRODUCE ENOUGH SHALLOW UPSLOPE TO FOCUS THE THUNDERSTORMS ALONG THE FRONT RANGE DURING THE LATE AFTN AND EVENING HOURS. THIS SCENARIO COULD ELEVATE THE FLOOD POTENTIAL...ESPECIALLY ALONG ALREADY SWOLLEN CREEKS AND STREAMS EXACERBATED BY THE RUNOFF. THE STORM MOTION IS PROGGED TO BE QUITE WEAK...SOUTHWEST AT AROUND 5 KTS. FOR SATURDAY...A DRIER SOUTHWESTERLY FLOW ALOFT WILL DEVELOP ACROSS THE REGION. PLENTY OF LOW LEVEL MOISTURE STILL AROUND HOWEVER. BETTER SHEAR WITH SOME SORT OF DRYLINE LIKELY DEVELOPING AS WELL. LOWER PW VALUES AND BETTER STORM MOTIONS WILL LESSEN THE FLASH FLOOD THREAT BUT INCREASE THE SEVERE THUNDERSTORM POTENTIAL. LARGE HAIL AND TSTM WINDS ALONG WITH A TORNADO THREAT AS WELL. NAM12 SOUNDINGS YIELD CAPES AROUND 900 J/KG OVER THE URBAN CORRIDOR WITH CLOSE TO 2000 J/KG OVER THE NORTHEAST PLAINS. NOTHING HAS CHANGED IN THE GRIDS THE REST OF THE PERIOD. THE DRIER PATTERN IS EXPECTED TO DEVELOP SUNDAY THROUGH TUESDAY...AHEAD OF AN UPPER TROUGH WHICH WILL MOVE INTO NEVADA. SLGT CHC POPS OVER THE MOUNTAINS EACH DAY...WITH A GREATER CHANCE OF STORMS POSSIBLY DEVELOPING OVER THE FAR NORTHEAST PLAINS BY TUESDAY. && .AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING) ISSUED AT 1049 AM MDT THU MAY 29 2014 DENVER CYCLONE HAS BEEN SPINNING AROUND KDEN THIS MORNING KEEP THE STRONGER SOUTHERLY WINDS JUST THE THE EAST. THIS WILL KEEP WIND DIRECTIONS TRICKY...ESPECIALLY AT KDEN. ASSUMING ONCE TEMPERATURES WARM MORE THE SOUTHEASTERLIES WILL BE ABLE TO PUSH IN A LITTLE FARTHER WEST TO AFFECT AT LEAST KDEN AND KAPA. LOOKING FOR CONVECTION TO BEGIN AFFECTING THE AIRPORTS AFTER 20Z. OVERALL...VFR CONDITIONS SHOULD PREVAIL THROUGH TONIGHT. STORM BASES WILL GENERALLY BE HIGH BUT INSTRUMENT APPROACHES MAY BE NEEDED AT KDEN FOR A SHORT TIME IF THE STORMS ARE MORE ORGANIZED THAN EXPECTED. THESE STORMS WILL BE GENERALLY SLOW MOVING AND WILL HAVE THE CHANCE OF PRODUCING GUSTY OUTFLOW WINDS TO 30 KTS. && .HYDROLOGY... ISSUED AT 1053 AM MDT THU MAY 29 2014 REISSUED THE FLOOD WARNING FOR THE CACHE LA POUDRE RIVER AT GREELEY DUE TO THE RIVER REMAINING HIGH FROM SNOWMELT...AND THE EXPECTED RAIN OVER THE NEXT COUPLE DAYS. NO CHANGES TO THE OTHER ADVISORIES IN EFFECT THIS MORNING. GENERALLY RISEN OVER THE LAST COUPLE OF DAYS WITH THE WARMING. IN GENERAL THE FLOWS ARE NOT EXPECTED TO PRODUCE MORE THAN MINOR LOWLAND FLOODING UNLESS THERE IS SIGNIFICANT RAINFALL...UNLIKELY TODAY BUT POSSIBLE THE NEXT COUPLE OF DAYS. GREATEST RISK IS THE NORTH PLATTE RIVER NEAR THE WYOMING BORDER WHERE THE SNOWMELT IS GREATEST...AND IN BOULDER AND LARIMER COUNTIES WHERE THE STREAMS WILL BE FULL AND THERE WILL BE A HIGHER THREAT OF SIGNIFICANT RAIN AS DESCRIBED BELOW. FOR FRIDAY AND FRIDAY NIGHT...INCREASING MOISTURE AND INSTABILITY IS EXPECTED...ESPECIALLY AFTER 21Z. A FRONTAL BOUNDARY IS PROGGED TO PUSH ITSELF INTO THE FRONT RANGE...WHICH COULD HELP TO ANCHOR THE DEVELOPMENT OF THUNDERSTORMS ALONG AND WEST OF THE FRONT. THIS COUPLED THE STORM MOTIONS OF 5 KTS AND ONGOING RUNOFF COULD INCREASE THE FLASH FLOOD THREAT. ON SATURDAY...THERE WILL BE SOME DECREASE IN THE HEAVY RAIN THREAT WITH DRIER MID LEVEL AIR INTRUDING FROM THE SOUTHWEST. THIS COUPLED WITH GREATER WEST TO EAST STORM MOTION MAY ALSO HELP TO SHIFT THE FOCUS FOR THE STORMS TO THE EAST OF THE FRONT RANGE. SOME OF THE STORMS HOWEVER COULD BE SEVERE PRODUCING LARGE HAIL AND DAMAGING WINDS ESPECIALLY OVER THE NORTHEAST PLAINS. THE HEAVY RAIN THREAT WILL STILL EXIST OVER THE NORTHEAST PLAINS. SUNDAY THROUGH TUESDAY...THE THREAT OF STORMS WILL BE EVEN LOWER WITH JUST A SLIGHT CHANCE OF THUNDERSTORM EACH DAY. RUNOFF AT THAT TIME WILL BE PRIMARILY A PRODUCT OF THE SNOWMELT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KRIEDERMAN SHORT TERM...GIMMESTAD LONG TERM...COOPER AVIATION...KRIEDERMAN HYDROLOGY...COOPER/GIMMESTAD/KRIEDERMAN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1109 PM MDT WED MAY 28 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 325 PM MDT WED MAY 28 2014 CURRENTLY... SHOWERS NOTED MAINLY OVER THE HIGHER TRRN...ESPECIALLY ACROSS THE SW MTNS AND WETS AND S SANGRES. FLOW ALOFT IS WEAK SO SHOWERS MOVING VERY SLOWLY. OTHERWISE IT WAS QUITE WARM WITH TEMPS IN THE 80S TO 90 ACROSS THE PLAINS...70 TO L80S VALLEYS...AND 50S AND 60S MTNS. REST OF TODAY AND TONITE... MAIN CHANGE I MADE TO THE FCST WAS TO INCLUDE SOME LOW END POPS TO N EL PASO COUNTY AND TO THE SAN LUIS VALLEY FOR THE REST OF THIS AFTERNOON AND EARLY EVENING. HRRR INDICATING A FEW SHOWERS WILL MOVE OUT A LITTLE FARTHER ONTO THE PLAINS. DISTURBANCE OFFSHORE OF S CALIF COAST IS BRINGING IN SOME HIGHER LEVEL MOISTURE TO THE SW...AND THESE CLOUDS SHOULD MOVE OVER THE REGION STARTING LATER THIS EVENING. TOMORROW(THURSDAY)... SHOULD SEE AN UPTICK IN HIGH CLOUDS AND SHOWERS OVER THE REGION TOMORROW...WITH A BETTER CHANCE OF SHOWERS MOVING A BIT FARTHER ONTO THE PLAINS AS FLOW ALOFT SHIFTS TO MORE SW ALOFT...ESPECIALLY OVER THE WESTERN SECTIONS OF THE PLAINS. FAR EASTERN PLAINS SHOULD REMAIN DRY THROUGH LATE TOMORROW AFTERNOON. MAX TEMPS TOMORROW SHOULD BE ABOUT SIMILAR TO TODAYS HIGHS. /HODANISH .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 325 PM MDT WED MAY 28 2014 PRIMARY METEOROLOGICAL ISSUES DURING THE LONGER TERM APPEAR TO BE TEMPERATURES AND POPS...WITH ATTENDANT HEAVY RAIN/SEVERE THREAT AT TIMES DURING PERIODS OF DEEPER ATMOSPHERIC MOISTURE INTRUSIONS. INITIALLY...RECENT LONGER TERM COMPUTER SIMULATIONS AND FORECAST MODEL SOUNDINGS SUGGEST THAT A SOMEWHAT ACTIVE METEOROLOGICAL PATTERN SHOULD BE NOTED AT TIMES OVER THE FORECAST DISTRICT FROM THURSDAY EVENING INTO SATURDAY AS UPPER ENERGY ROTATING AROUND UPPER LOW OVER THE PACIFIC NORTHWEST/INTER-MOUNTAIN REGION INTERACTS WITH ADEQUATE ATMOSPHERIC MOISTURE VALUES. WFO PUEBLO WILL NEED TO MONITOR FOR STRONG STORMS AND LOCALLY HEAVY RAIN(ESPECIALLY OVER/NEAR AREA BURN SCARS) DURING THIS TIME-FRAME. SATURDAY NIGHT INTO SUNDAY APPEARS TO BE A TRANSITION DAY TO DRIER CONDITIONS AS UPPER DISTURBANCE MOVING INTO/ACROSS MONTANA ALLOWS A DRIER AIRMASS TO DEVELOP OVER THE MAJORITY OF THE CWFA. FORECAST DISTRICT SHOULD CONTINUE TO NOTICE BASICALLY DRY CONDITIONS INTO TUESDAY AS TRANSITORY UPPER ZONAL TO UPPER RIDGING PATTERN IMPACTS THE FORECAST DISTRICT. A RETURN TO A MORE UNSETTLED METEOROLOGICAL REGIME SHOULD THEN DEVELOP FROM LATER TUESDAY INTO AT LEAST NEXT WEDNESDAY AS DEEPER ATMOSPHERIC MOISTURE...NORTHERLY SURGE OVER EASTERN SECTIONS AND UPPER DISTURBANCES IMPACT SOUTHERN COLORADO. LATEST COMPUTER SIMULATIONS SUGGEST THAT THE SEVERE WEATHER THREAT MAY BE INCREASING BY NEXT WEDNESDAY(ESPECIALLY EASTERN SECTIONS) AS MEAN LAYER SHEAR...ATMOSPHERIC MOISTURE AND INSTABILITIES ALL BECOME MORE FAVORABLE. FINALLY...ABOVE CLIMATOLOGICAL LATE MAY/EARLY JUNE TEMPERATURES ARE ANTICIPATED DURING THE LONGER TERM WITH THE WEEKEND EXPECTED TO EXPERIENCE THE WARMEST CONDITIONS...WHILE BY MID-WEEK NEXT WEEK TEMPERATURES DROP TO NEAR SEASONAL AVERAGES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1106 PM MDT WED MAY 28 2014 VFR CONDITIONS AT ALL THREE TERMINALS THROUGH THURSDAY LATE MORNING TO EARLY AFTERNOON. WINDS WILL GENERALLY BE SOUTHERLY UNDER 15 KTS AT ALL THREE TERMINALS. THE LATEST MODELS DEVELOP SHOWER AND THUNDERSTORM ACTIVITY OVER THE MOUNTAINS BY EARLY AFTERNOON AND MOVE IT INTO THE SAN LUIS VALLEY AND PALMER DIVIDE REGIONS THROUGH THE AFTERNOON AND EVENING...IMPACTING KALS AND KCOS. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
703 PM EDT FRI MAY 30 2014 .SYNOPSIS... SHOWERS AND SCATTERED THUNDERSTORMS INTO THIS EVENING LINGER THROUGH THE OVERNIGHT ALONG AND AHEAD OF A COLD FRONT. COOL WEATHER AND THE THREAT OF ADDITIONAL SHOWERS LINGER THROUGH SATURDAY...THEN WARMER AND DRY CONDITIONS FOLLOW FOR SUNDAY INTO EARLY NEXT WEEK. ANOTHER CHANCE OF SHOWERS IS POSSIBLE BY MIDWEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 7 PM UPDATE... ROBUST SHORT WAVE TROUGH ROTATING THROUGH NEW ENGLAND THIS EVENING TRIGGERING SCATTERED SHOWERS AND TSTMS. THIS FEATURE IS ASSOCIATED WITH AN ANAMOLOUS UPPER LEVEL JET STREAK OF 125 KT FROM QUEBEC SOUTHWARD INTO NY STATE...WITH LFQ OVER WESTERN NEW ENGLAND. LOTS OF CURVATURE WITHIN THIS JET ENHANCING DIVERGENCE/QG FORCING. ALSO STORMS IN WORCESTER COUNTY INTENSIFIED COURTSEY OF INTERACTION WITH LEFTOVER SEABREEZE BOUNDARY FROM RI AND EASTERN MA. MAIN THREATS WITH THESE STORMS WILL BE HAIL GIVEN COLD TEMPS ALOFT YIELDING LOW FREEZING LEVELS /ABOUT 7 KFT/ AND ALSO GUSTY WINDS IN RESPONSE TO LARGE TEMP/DEW PT SPREADS /INVERTED / SIGNATURE/. ALSO SOME BRIEF HEAVY DOWNPOURS AS WELL. PAST SEVERAL RUNS OF THE HRRR APPEAR TO HAVE A GOOD HANDLE ON CONVECTION AND BRINGS SHOWERS AND TSTMS IN A WEAKEN STATE ALL THE WAY TO THE SOUTH COAST LATER THIS EVENING. THIS SEEMS REASONABLE GIVEN LOSS OF DAYTIME HEATING. PREVIOUS FORECAST CAPTURED THESE DETAILS NICELY. THUS ONLY CHANGE WAS TO MODIFY HOURLY POPS AND SKY TO BETTER REFLECT CURRENT RADAR AND SATELLITE TRENDS. EARLIER DISCUSSION BELOW. ------------------------------------------------------------------ SHOWERS AND THUNDERSTORMS /A FEW OF WHICH THAT ARE NOTABLY STRONG WITHIN THE LATEST RADAR SCANS/ BECOMING MORE WIDESPREAD INTO S NEW ENGLAND AS THE PARENT MID-LEVEL IMPULSE AND COLD FRONT SWEEP INTO THE REGION. ENVIRONMENT ALONG AND AHEAD A COMBINATION OF MODEST STRAIGHT-LINE BULK SHEAR AND MEAGER INSTABILITY ON THE ORDER OF 250-500 J/KG PER SPC MESOANALYSIS /SKINNY CAPES PER RAP-MODEL SOUNDINGS/. AS SUCH AND TO NO SURPRISE...OBSERVING SMALL-CORES WITH STORMS WHICH DO SUSTAIN FOR A SHORT PERIOD OF TIME...ENOUGH TO SUPPORT THE THREAT OF SMALL HAIL DUE TO THE LOW FREEZING LEVEL HEIGHTS AND COLD- POOL ALOFT...AS WELL AS GUSTY WINDS WITH DRY LOW-LEVELS AND INVERTED-V BOUNDARY-LAYER PROFILES. THUS WILL CONTINUE TO RIDE WITH THE FORECAST OF WIDESPREAD SHOWERS AND THUNDERSTORMS INTO THIS EVENING...TO WHICH SOME OF THE STORMS MAY CONTAIN THE THREATS OF SMALL HAIL AND GUSTY WINDS. STORMS MAY CONGEAL INTO A LINE LATE IN THE FORECAST PERIOD AHEAD OF THE COLD FRONT AS THE HRRR WOULD SUGGEST. FIGURE THIS BE THE CASE AS THE COLD FRONT CLASHES WITH THE SEA-BREEZE GENERATING A REGION OF LOCALIZED CONVERGENCE. NEED TO ALSO MONITOR FOR ENHANCEMENT OF THREATS ALONG THE N- AND W-FACING SLOPES OF HIGH TERRAIN. HEAVY RAIN REMAINS A THREAT THOUGH A LOW ONE TO SMALL HAIL AND GUSTY WINDS. BOUNDARY-LAYER WHICH AS DESTABILIZED ALLOWING FOR STEEP LOW- LEVEL LAPSE RATES AND INVOKING BRISK E-FLOW TO THE REAR OF AN ONSHORE SEA-BREEZE FROM THE E /DISCERNED VIA LATEST OBS AND VISIBLE SATELLITE/. CONTINUE TO TREND WITH HRRR- AND WRF-MODEL SOLUTIONS ALONG WITH THE LATEST RAP. TONIGHT... RAINS LINGER ALONG THE COLD FRONT AS IT SWEEPS OFFSHORE. EXPECTING THUNDERSTORM ACTIVITY TO DIMINISH WITH CONCLUSION OF BUOYANCY WITH PEAK-HEATING. N-WINDS PREVAILING BEHIND WHICH COOLER AND DRIER AIR BUILDS SOUTHWARD. YET ANOTHER MID-LEVEL IMPULSE ROUNDING THE BROAD CYCLONIC FLOW APPROACHES FROM THE NE AND INVOKES LOW- TO MID-LEVEL ASCENT OF RESIDUAL MOISTURE. RENEWANCE OF WIDELY SCATTERED LIGHT SHOWERS IS ANTICIPATED ACROSS E NEW ENGLAND OVERNIGHT...SHIFTING W TOWARDS INTERIOR NEW ENGLAND INTO SATURDAY MORNING. MOSTLY CLOUDY CONDITIONS BENEATH WHICH BRISK N-WINDS PREVAIL. WILL BE A COOL AND DAMP NIGHT. EXPECTING LOWS TO DIP INTO THE 40S. MAY HAVE TO CLOSELY MONITOR FOR PATCHY DENSE FOG EARLIER RAINS WILL LIKELY RESULT IN HIGHER DEWPOINT AIR. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... SATURDAY... MID-LEVEL IMPULSE PUSHES W INTO THE HUDSON RIVER VALLEY ALONG WITH LIGHT SHOWER ACTIVITY. SINKING DRIER AIR BUILDS REARWARD ACTING TO SUPPRESS ACTIVING E TO W. DO NOT BELIEVE THE ENVIRONMENT AHEAD WILL BE ALLOWED TO DESTABILIZE. FEEL THE WAVE WILL BE W OF THE REGION BY MIDDAY WITH THE LATER-HALF OF THE DAY DRY /EXCEPT PERHAPS ALONG THE E-SLOPES OF HIGHER TERRAIN WITH OROGRAPHIC CONVERGENCE/. THUS NO THUNDERSTORMS ARE EXPECTED. ONSHORE FLOW BENEATH H85 TEMPERATURES AROUND +4C...GOING TO BE A CHILLY DAY. WITH THE LATE-MAY SUN BREAKING OUT DURING THE LATER-HALF OF THE DAY...WILL PREVAIL WITH HIGHS IN THE MID- TO UPPER-60S. SATURDAY NIGHT... SUBSIDENCE PREVAILS. HIGH PRESSURE IN CONTROL. LIGHT AND VARIABLE WINDS EXCEPT PERHAPS ALONG THE E-COAST. RADIATIONAL COOLING LIKELY TO PREVAIL ACROSS INTERIOR NEW ENGLAND. WILL PUSH TEMPERATURES DOWN BY SEVERAL DEGREES LOWER THAN THE CONSENSUS FORECASTING WOULD SUGGEST. LOWS DOWN INTO THE LOW-40S. MAY NEED TO MONITOR FOR THE POTENTIAL OF FROST/FREEZE HEADLINES TOWARDS SUNDAY MORNING. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGHLIGHTS... * DRY AND WARMING TREND SUN AND MON * SHOWERS AT TIMES MIDDLE OF NEXT WEEK * TEMPS NEXT WEEK AT OR WARMER THAN NORMAL OVERVIEW... BOTH 00Z ECENS AND 00Z GEFS ENSEMBLES IN VERY GOOD AGREEMENT THRU NEXT WEEK ON THE LARGE SCALE FLOW PATTERN ACROSS NORTH AMERICA. THUS FORECAST CONFIDENCE IS PERIOD IS ABOVE AVERAGE. RIDGING OVER THE OHIO VALLEY NORTHWARD INTO THE EASTERN GREAT LAKES/ONTARIO AND QUEBEC 12Z SUN SLIDES EAST INTO NEW ENGLAND THRU MON. THIS PROVIDES DRY WEATHER ALONG WITH A WARMING TREND. BY 12Z TUE ENSEMBLES IN GOOD AGREEMENT THAT MEAN LONG WAVE RIDGE AXIS IS CENTERED OVER NEW ENGLAND AND BEGINNING TO DRIFT OFFSHORE. HOWEVER WITH NEXT UPSTREAM MEAN TROUGH AXIS JUST APPROACHING THE GREAT LAKES...DRY WEATHER MAY LINGER INTO MUCH OF TUE. 12Z DETERMINISTIC RUNS ARE MORE BULLISH/FASTER WITH UPSTREAM TROUGH. HOWEVER AT THIS TIME RANGE ENSEMBLES SHOULD VERIFY BETTER. A MODEL BLEND DEPICTS THIS NICELY SO WILL FOLLOW ACCORDINGLY. BY WED AND THU OF NEXT WEEK MEAN MID LEVEL TROUGH AXIS IS OVER THE REGION YIELDING A HIGH RISK OF SCATTERED AFTERNOON/EVENING SHOWERS. AS FOR THE RISK OF STRONG CONVECTION...THE GEFS ENSEMBLES INDICATING LITTLE IF ANY CAPE OVER NEW ENGLAND WITH BEST INSTABILITY WEST ACROSS NY/PA AND NJ. HENCE WARM SECTOR REMAINS SOUTH AND WEST OF THE AREA. HOWEVER GIVEN THE TIME RANGE HERE CAN/T RULE OUT TSTMS ESPECIALLY INTO WESTERN NEW ENGLAND BUT WILL LEAVE OUT OF THE FORECAST FOR NOW GIVEN THE UNCERTAINTY ON POSITION OF WARM FRONT. BY LATE NEXT WEEK MEAN TROUGH BEGINS TO DEAMPLIFY AND EJECTS NORTHEAST OUT OF NEW ENGLAND. THUS SOME IMPROVEMENT/ DRYING TREND IS POSSIBLE LATE NEXT WEEK. DAILY DETAILS... SUNDAY... REAL NICE DAY WITH HIGH PRES IN CONTROL BRINGING DRY CONDITIONS AND LIGHT WINDS. CHILLY TO START THE DAY /40S/ BUT STRONG JUNE SUNSHINE WILL MODIFY THE AIRMASS WITH HIGHS WARMING WELL INTO THE 70S. COOLER AT THE COAST GIVEN AFTERNOON SEABREEZES. MONDAY... HIGH PRES SHIFTS TO THE S OF NEW ENG WITH SW FLOW AND ASSOCIATED LOW LEVEL WARM ADVECTION YIELDING HIGHS IN THE U70S TO L80S EXCEPT COOLER ALONG THE SOUTH COAST GIVEN WIND TRAJECTORY OFF THE COOLER OCEAN WATERS. TUESDAY THROUGH THURSDAY... MEAN MID LEVEL TROUGH AND ASSOCIATED SURFACE LOW EXITS THE GREAT LAKES AND TRACKS INTO SOUTHEAST CANADA WITH ITS FRONTAL BOUNDARY INTO NEW ENGLAND. ENSEMBLES SUGGEST DEEP LAYER RIDGING MAY LINGER LONG ENOUGH FOR DRY WEATHER TO PERSIST INTO TUE ESPECIALLY ACROSS RI AND EASTERN MA. HOWEVER BY WED AND THU ENSEMBLES AGREE MEAN TROUGH AXIS WILL BE OVER THE AREA...THUS HIGHEST RISK FOR SHOWERS /ESPECIALLY AFTERNOON AND EARLY EVENING/ WILL BE WED AND THU. AS FOR TEMPS...GIVEN ALL MODEL DATASETS SUGGEST TRUE WARM SECTOR REMAINS SOUTH AND WEST OF NEW ENGLAND...COOLEST TEMPS WILL BE ACROSS EASTERN MA AND WARMEST IN THE CT RVR VLY. IN FACT MODELS HINTING A POSSIBLE BACKDOOR COLD FRONT WED/THU POTENTIALLY IMPACTING NORTHEAST MA. THUS COOLER THAN NORMAL CONDITIONS POSSIBLE FOR THIS AREA. GIVEN THE TIME RANGE HERE AND MESOSCALE ASPECTS OF BACKDOOR FRONT WILL NOT TRY TO INDICATE COOLER TEMPS AND JUST KEEP AN EYE ON LATER MODEL RUNS. FRIDAY... ENSEMBLES SUGGEST MEAN MID LEVEL TROUGH DEAMPLIFIES AND EJECTS NORTHEAST AWAY FROM NEW ENGLAND. THIS SHOULD REDUCE THE RISK OF SHOWERS...HENCE DRYING TREND POSSIBLE HERE ALONG WITH TEMPS AT LEAST SEASONABLY WARM. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. .SHORT-TERM /INTO SUNDAY MORNING/...MODERATE CONFIDENCE. 7 PM UPDATE... SHOWERS AND TSTMS OVER EASTERN CT-CENTRAL MA INTO SOUTHEAST NH WILL CONTINUE TO SLIDE SOUTHEAST BUT WILL WEAKEN WITH TIME. AN ISOLATED TSTM MAY CONTAIN SMALL HAIL...GUSTY WINDS AND BRIEF HEAVY RAIN. BUT TRENDS WILL BE FOR STORMS TO WEAKEN GIVEN SUNSET/LOSS OF DAYTIME HEATING. WEAKENING SHOWERS WILL MAKE IT TO THE SOUTH COAST INCLUDING CAPE COD AND THE ISLANDS LATER THIS EVEING. EARLIER DISCUSSION BELOW. ----------------------------------------------------------------- ACTIVITY DIMINISHING OVERNIGHT BEHIND A COLD FRONT. WIDELY SCT SHRA LINGER INTO SATURDAY...SWEEPING E TO W DURING THE EARLY-HALF OF THE DAY. ACTIVITY CONCLUDES TOWARDS THE LATER-HALF OF SATURDAY. VFR UNDER BREEZY NE-WINDS WITH GUSTS UP TO 25 KTS. WINDS DIMINISH INTO SUNDAY MORNING WITH HIGH PRES. DENSE IFR-LIFR FOG POSSIBLE ACROSS THE INTERIOR. KBOS TAF...MODERATE TO HIGH CONFIDENCE IN TAF. LOW RISK OF TSRA THUS WILL CONTINUE TO KEEP IT OUT. SHRA MAY LINGER INTO EARLY SATURDAY MORNING. KBDL TAF...MODERATE TO HIGH CONFIDENCE IN TAF. SHRA/TSRA EXITING ALY AT 23Z SHOULD WEAKEN AS STORMS APPROACH KBDL. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUNDAY/MONDAY...HIGH CONFIDENCE FOR VFR AND DRY WEATHER. SEABREEZES SUN AFTERNOON. TUESDAY/WEDNESDAY...MODERATE CONFIDENCE. VFR TO START BUT LIKELY LOWERING TO MVFR IN SCT SHOWERS TUE NIGHT INTO WED FROM WEST TO EAST. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. .SHORT-TERM /INTO SUNDAY MORNING/...MODERATE CONFIDENCE. E/SE FLOW PREVAILING THIS EVENING AHEAD OF A COLD FRONT WHICH WILL SWEEP INTO THE WATERS OVERNIGHT. SHOWERS WILL ENTER THE WATERS AHEAD OF THE COLD FRONT WITH LOWER CONFIDENCE OF THUNDERSTORMS. WITH COLD FRONTAL PASSAGE...WINDS BACK OUT OF THE NE AND INCREASE TOWARDS LATE SATURDAY INTO SATURDAY NIGHT. WINDS OF 10 TO 15 KTS WITH GUSTS UP TO 25 KTS POSSIBLE HAVE RESULTED IN THE ISSUANCE OF SMALL-CRAFT ADVISORIES. WAVES BUILDING TO 5 FEET MAY LINGER INTO SUNDAY EVEN THOUGH WINDS WILL DIMINISH UNDER INCREASING HIGH PRES. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUNDAY...HIGH CONFIDENCE. FINE BOATING WEATHER WITH HIGH PRES OVER THE WATERS. LITTLE IF ANY WIND WAVES ALONG WITH GOOD VSBY AND DRY WEATHER. ONLY POSSIBLE ISSUE WILL BE LEFTOVER 4-6 FT EASTERLY SWELLS MAINLY CONFINED TO THE SOUTH AND EAST WATERS OF NANTUCKET. MONDAY...HIGH CONFIDENCE CONTINUES AS HIGH PRES SLOWLY SLIDES SOUTH OF NEW ENGLAND YIELDING SW WINDS. LEFTOVER EAST SWELLS 3-6 FT MAY PERSIST OVER EASTERN OUTER OCEAN WATERS. TUESDAY...MODERATE CONFIDENCE. S/SE FLOW GETS UNDERWAY AHEAD OF APPROACHING WARM FRONT. SPEEDS SHOULD REMAIN LESS THAN 20 KT. WEDNESDAY...LOW TO MODERATE CONFIDENCE. WARM FRONT APPROACHES WITH AN INCREASED RISK OF SHOWERS AND PERHAPS A TSTM OVER THE SOUTHERN WATERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 11 AM SATURDAY TO 2 AM EDT SUNDAY FOR ANZ231>235-237. SMALL CRAFT ADVISORY FROM 2 PM TO 8 PM EDT SATURDAY FOR ANZ236. SMALL CRAFT ADVISORY FROM 11 AM SATURDAY TO 8 AM EDT SUNDAY FOR ANZ254>256. && $$ SYNOPSIS...NOCERA/SIPPRELL NEAR TERM...NOCERA/SIPPRELL - 7 PM SHORT TERM...SIPPRELL LONG TERM...NOCERA - 7 PM AVIATION...NOCERA/SIPPRELL - 7 PM MARINE...NOCERA/SIPPRELL - 7 PM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
701 PM EDT THU MAY 29 2014 .SYNOPSIS... ANOTHER NIGHT OF COOL AND DRY WEATHER FOLLOWED BY A COLD FRONT WITH SHOWERS AND THUNDERSTORMS FRIDAY INTO FRIDAY NIGHT. COOL WEATHER LINGERS THROUGH THE WEEKEND...BUT EXPECT WARMER CONDITIONS INTO EARLY NEXT WEEK PRIOR TO A RENEWED THREAT OF WET-WEATHER BY MIDWEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 7 PM UPDATE... FORECAST IN GOOD SHAPE. ONLY FEW HIGH CLOUDS OVER REGION THIS EVENING WITH MORE SOLID CLOUD COVER REMAINING BACK ACROSS NEW YORK STATE. HIGH-RES RAP STILL INSISTS ON LOW CLOUDS/FOG REACHING S COAST OVERNIGHT. EARLIER DISCUSSION FOLLOWS... MOSTLY CLEAR SKIES AND LIGHT WINDS WILL LEAD TO ANOTHER EVENING OF EFFECTIVE RADIATIONAL COOLING. HIGHEST CONFIDENCE ACROSS SE MA...W-CAPE...AND MARTHAS VINEYARD. WOULD NOT BE SURPRISED TO HAVE A FEW LOCALES IN THOSE AREAS FALL BELOW 40-DEGREES. THOSE AREAS THAT RADIATE OUT EFFECTIVELY...WOULD EXPECT PATCHY GROUND FOG. SOME UNCERTAINTY...WATCHING THE CLOUD DECK WELL OFFSHORE. PLAUSIBLE THAT WITH S/SE WINDS LOW CLOUDS AND FOG WILL IMPACT THE S-COASTLINE OF NEW ENGLAND. WILL PREVAIL IN THE FORECAST ACROSS SE CAPE COD WHERE CONFIDENCE IS HIGHEST. UNCERTAIN AS TO ELSEWHERE. WILL LEAVE FOR THE OVERNIGHT CREW TO ASSESS. TO THE W...MID-LEVEL IMPULSE AND ACCOMPANYING TROUGH SWEEP NW-SE THROUGH THE REGION. BROKEN-OVERCAST CLOUDS VIA SATELLITE ACROSS THE MID-ATLANTIC TO LAKE ONTARIO ADVECT N AND W IN RESPONSE TO ASCENT AHEAD OF THE TROUGH AXIS. SOME LIGHT SHOWER ACTIVITY ACROSS N/W- FACES OF HIGHER TERRAIN IS POSSIBLE. SHOULD SEE MILDER CONDITIONS WITH LOWS DOWN TO AROUND THE UPPER-40S UNDER LIGHT S/SW-WINDS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FRIDAY INTO FRIDAY NIGHT... ANOTHER MID-LEVEL IMPULSE DIVES NW-SE ACROSS THE NE-CONUS DURING THE DAY. SUBSEQUENT TROUGHING AND FALLING HEIGHTS PARENT WITH A COLD FRONT YIELDS AN AREA OF STRONG ASCENT OVER MUCH OF S NEW ENGLAND BENEATH CYCLING FLOW AND MOIST-ADIABATIC MID-LEVEL LAPSE RATES OF 6C PER KM. EXPECTING A POSSIBLE LINE OF SHOWERS AND THUNDERSTORMS. BUT SOME CONSIDERATIONS TO POINT OUT: WITH CLOUDS ADVECTING E OVERNIGHT WILL ASSUME LESSER DESTABILIZATION TO THE W. ANTICIPATE CENTRAL-S/E PORTIONS OF S NEW ENGLAND TO SEE SUNSHINE ALLOWING BOUNDARY-LAYER MIXING AND LOW-LEVEL LAPSE RATES TO STEEPEN TO DRY-ADIABATIC. INSTABILITY SUBSEQUENTLY BUILDS TO AROUND 500 J/KG...AN AXIS OF WHICH WILL EXIST OVER THE INTERIOR AWAY FROM THE IMMEDIATE COAST WITH ANTICIPATED ONSHORE SEA-BREEZE BEHIND WHICH COOLER AND MORE STABLE AIR PREVAILS. ALSO MUST NOTE THAT STRONGEST WINDS AND BETTER DYNAMICS RESIDE WELL W OF THE REGION. WHILE NW-SE UNIDIRECTIONAL SHEAR PREVAILS...IT IS MINOR TO MODEST AT MOST...NOT OVERWHELMING. MORE NOTABLY...0-6 KM MEAN WINDS NW-SE ARE LIGHT AND CARVED VECTORS ARE NEAR-ZERO. TAKING THE POINTS ABOVE INTO CONSIDERATION AND EVALUATING HIGH-RES FORECAST MODELS ALONG WITH THE WEAK WIND PATTERN...ANTICIPATE A LINE OF SHOWERS TO DEVELOP INITIALLY ALONG THE FRONT...BUT AS IT RACES SE IT IS LIKELY TO INTERACT WITH A MORE UNSTABLE AIRMASS AND CLASH WITH THE ONSHORE SEA-BREEZE. EXACTLY WHERE IS SOMEWHAT UNCERTAIN. HIGHEST CONFIDENCE ACROSS THE INTERIOR W OF THE SEA-BREEZE FRONT. SHOULD SEE EMBEDDED HEAVY RAIN AND THUNDERSTORMS. LOW CONFIDENCE CONCERNING SEVERE WEATHER THREATS YET CAN NOT RULE OUT POSSIBLE HAIL AS WET-BULB FREEZING LEVEL HEIGHTS ARE LOW AROUND 7 KFT. AM MORE CONCERNED WITH THE THREAT OF HEAVY RAIN ALONG WITH URBAN AND POOR DRAINAGE FLOODING ESP ALONG THE N/W FACING SLOPES OF HIGH TERRAIN. PWATS UP TO AN INCH ARE FORECAST. WILL INSERT THE THREAT OF HEAVY RAIN INTO THE FORECAST. HIGHS GETTING UP TO 70-DEGREES. ACTIVITY TO LINGER INTO THE EVENING PERIOD GRADUALLY DISSIPATING OVERNIGHT. CLOUDS AND LIGHT SHOWERY WEATHER LIKELY TO LINGER WITHIN THE CYCLONIC CONVERGENT FLOW ACROSS E NEW ENGLAND...BUT ALL ASIDE WITH WINDS PREVAILING OUT OF THE N ANOTHER CHILLY NIGHT IS EXPECTED. && .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGHLIGHTS... * COOL ONSHORE FLOW SAT WITH FEW A SHOWERS INLAND * DRY AND WARMER SUN/MON * SHOWERS AT TIMES TUE-THU WITH NEAR AVERAGE TEMPS OVERVIEW...ENSEMBLES AND MEDIUM RANGE MODELS REMAIN IN GOOD AGREEMENT THROUGH EARLY NEXT WEEK...THEN DIVERGE SIGNIFICANTLY FOR MID TO LATE WEEK WHICH LENDS LOW CONFIDENCE IN FORECAST. CLOSED LOW WELL OFF NEW ENGLAND COAST HEADS FARTHER OUT TO SEA SAT...WHICH ALLOWS SOME OF MIDWEST RIDGING TO SHIFT E INTO OUR AREA SUN/MON. RIDGE BREAKS DOWN FROM THERE AS NEXT UPPER TROUGH SWINGS DOWN OUT OF NORTHERN PLAINS. MODELS/ENSEMBLES VARY CONSIDERABLY WITH STRENGTH AND POSITION OF THIS FEATURE AS IT REACHES GREAT LAKES/NORTHEAST MID TO LATE WEEK...WHICH AFFECTS POSITION OF WARM FRONT WHICH SHOULD BECOME STATIONARY NEAR NEW ENGLAND. SATURDAY...HIGH CONFIDENCE. LAST SHORT WAVE ROTATING AROUND UPPER LOW WELL OFFSHORE SHOULD PRODUCE SCATTERED SHOWERS/ISOLATED THUNDER AS COLD TEMPERATURES ALOFT /NEAR -20C AT 500 MB/ YIELD STEEP MID LEVEL LAPSE RATES. ACTIVITY SHOULD BECOME FOCUSED OVER WESTERN NEW ENGLAND BY AFTERNOON AS DRIER AIR ADVECTS IN FROM OCEAN. ONSHORE FLOW WILL KEEP HIGHS IN 60S TO NEAR 70. SUNDAY AND MONDAY...HIGH CONFIDENCE. HIGH PRESSURE BUILDS OVER NEW ENGLAND SUN WITH PLENTY OF SUNSHINE AND AFTERNOON SEA BREEZES. SW FLOW GETS UNDERWAY MON AS HIGH BUILDS TO MID ATLANTIC COAST WITH INCREASING CLOUDS DURING AFTERNOON AHEAD OF NEXT SYSTEM. SCATTERED SHOWERS SHOULD ARRIVE MON NIGHT. HIGHS SHOULD TOP OUT IN 60S COAST/70S INLAND SUN THEN WARM INTO 70S/NEAR 80 MON AWAY FROM S COAST /60S/. TUESDAY THROUGH THURSDAY...LOW CONFIDENCE. FORECAST HINGES ON POSITION OF WARM FRONT WHICH IS HIGHLY UNCERTAIN THIS FAR OUT IN TIME...BUT SHOULD BECOME STATIONARY OVER OR JUST S OF NEW ENGLAND. EXPECT TO SEE AT LEAST SCATTERED SHOWERS DURING THIS PERIOD...ESPECIALLY TUE AND AGAIN WED NIGHT/THU PER ENSEMBLES...BUT ALL THREE DAYS LIKELY TO FEATURE GOOD AMOUNT OF CLOUDS AND S/SE FLOW. RELYING HEAVILY ON BLEND OF MODEL GUIDANCE WITH HIGHS IN 60S/70S EACH DAY. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH FRIDAY/...MODERATE CONFIDENCE. VFR. SEA BREEZES DECAY THIS EVENING. IFR CIGS/VSBYS STILL ON TRACK TO REACH CAPE COD AND ISLANDS AFTER 06Z AND SHOULD DISSIPATE AROUND SUNRISE. HIGHER CONFIDENCE WITH THE DEVELOPMENT OF SHRA/TSRA SWEEPING NW TO SE BEGINNING FRIDAY MIDDAY AND CONTINUING INTO THE EVENING. ACCOMPANYING TEMPO MVFR-IFR CONDITIONS POSSIBLE. KBOS TAF...HIGH CONFIDENCE IN TAF. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...HIGH CONFIDENCE. VFR EXCEPT SCT SHOWERS/LOCAL MVFR ACROSS WESTERN NEW ENGLAND. SUNDAY AND MONDAY...HIGH CONFIDENCE. VFR. SEA BREEZES SUN AFTERNOON. TUESDAY...MODERATE CONFIDENCE. MVFR IN SCT SHOWERS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. .SHORT-TERM /THROUGH FRIDAY/...HIGH CONFIDENCE. WHILE QUIET BOATING WEATHER IS EXPECTED...WINDS WILL VEER OUT OF THE S. THERE IS THE CHANCE OF SHOWERS AND POSSIBLY THE THREAT OF THUNDERSTORMS FRIDAY EVENING. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...HIGH CONFIDENCE. NE WINDS AS LOW PRESSURE PASSES WELL SE OF NEW ENGLAND...STRONGEST NEAR CAPE COD/ISLANDS BUT SHOULD REMAIN BELOW SCA. SEAS MAY REACH 5 FT WELL OFFSHORE. SUNDAY AND MONDAY...HIGH CONFIDENCE. HIGH PRESSURE BUILDS OVER NEW ENGLAND WITH AFTERNOON SEA BREEZES SUN...THEN MORE OF S/SW FLOW MON AS HIGH SHIFTS S OF WATERS. LEFTOVER E SWELL NEAR 5 FT MAY PERSIST ON OUTER WATERS. TUESDAY...MODERATE CONFIDENCE. S/SE FLOW GETS UNDERWAY AHEAD OF APPROACHING WARM FRONT WITH SCATTERED SHOWERS. WINDS SHOULD REMAIN BELOW SCA BUT SEAS ON OUTER WATERS MAY REACH 5 FT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...SIPPRELL/JWD NEAR TERM...JWD SHORT TERM...SIPPRELL LONG TERM...JWD AVIATION...SIPPRELL/JWD MARINE...SIPPRELL/JWD
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
340 PM EDT THU MAY 29 2014 .SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A NORTHERN STREAM FLOW ARRIVING OVER THE PACIFIC NORTHWEST AROUND THE BASE OF A SHARP TROUGH AXIS BEFORE RIDGING BACK TO THE NORTH THROUGH SOUTH-CENTRAL CANADA. THE FLOW THEN DROPS BACK TO THE SOUTHEAST THROUGH THE GREAT LAKES AND THEN OFF THE NEW ENGLAND COAST. THE OTHER FEATURE OF NOTE IS A CUT-OFF UPPER LOW STALLED NEAR THE BASE OF THE NORTHERN STREAM RIDGE OVER THE SOUTHERN MS VALLEY. THIS FEATURE WILL NEVER REALLY HAVE A SIGNIFICANT INFLUENCE ON OUR LOCAL WEATHER AS IT SPINS AND PLACE AND SLOWLY FILLS DURING THE NEXT 24-48 HOURS. 29/12Z KTBW SOUNDING SHOWS A SEASONABLE PROFILE WITH A PW VALUES OF JUST UNDER 1.5". MID-LEVEL TEMPS ARE A BIT ON THE COOL SIDE WITH A MEASURED 500MB TEMP AROUND -11C. THIS IS ABOUT A DEGREE COOLER THAN THE NAM/GFS FORECAST. A DEGREE DOES NOT SOUND LIKE MUCH...BUT CAN BE ALL THE DIFFERENCE IN THE WORLD OF A RISING AIR PARCEL. EITHER WAY...-11C IS ON THE COOL SIDE AND SHOULD HELP SUPPORT AFTERNOON/EVENING STORM DEVELOPMENT...AT LEAST INITIALLY UNTIL LATENT HEAT RELEASE FROM THE EARLY CONVECTION BEGINS TO CONTAMINATE THE OVERALL COLUMN. AT THE SURFACE...THE FL PENINSULA RESIDES ON THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE AXIS PROVIDING A GENERAL SOUTHEAST FLOW PATTERN IN THE 1000-700MB LAYER. AS LONG AS THE COLUMN IS NOT TOO DRY (WHICH IT IS NOT)...THEN THIS FLOW PATTERN TENDS TO BE WET ONE IN TERMS OF STORMS COVERAGE THROUGH THE COURSE OF THE AFTERNOON/EVENING. && .SHORT TERM (REST OF TODAY THROUGH FRIDAY)... AS WOULD BE EXPECTED WITH A MODERATE SE FLOW REGIME IN THE LOWER LEVELS...THE EARLIER ACTIVITY HAS FORMED OVER THE SOUTHERN ZONES. HAVE SEEN A FEW MORE FOCUSED STORMS OVER THE NATURE COAST...BUT THE WIDESPREAD CONVECTION HAS BEEN DOWN TOWARD FORT MYERS AND PUNTA GORDA. WOULD EXPECT THIS ACTIVITY TO "RIPPLE" NORTHWARD UP THE SEA-BREEZE DURING THE NEXT SEVERAL HOURS INTO THE TAMPA BAY/I-4 CORRIDOR AND THEN EVEN FURTHER NORTHWARD WITH TIME. LOCAL HIRES WRFARW RUNS AND LATEST HRRR CONTINUE TO SUGGEST MODERATE UPDRAFT STRENGTH...INDICATIVE OF A FEW STRONGER STORMS...BUT GENERALLY NOT WIDESPREAD SEVERE. CURRENT RAIN CHANCES THROUGH THE EARLY EVENING CONTINUE TO INDICATE LIKELY WORDING UP ALONG THE I-75 CORRIDOR AND SEE LITTLE REASON TO MAKE SIGNIFICANT CHANGES AT THIS TIME. THIS FLOW REGIME USUALLY SEES THE EARLIER ENDING TO THE CONVECTION OVER THE SOUTHERN ZONES WITH THE TAMPA BAY AREA AND NATURE COAST HOLDING HIGHER RAIN CHANCES THROUGH 00-02 UTC. BY LATER THIS EVENING...ALL AREAS SHOULD QUIET DOWN AND RESULT IN A GENERALLY DRY OVERNIGHT PERIOD WITH SEASONABLE TEMPS. A VERY SIMILAR SYNOPTIC PATTERN APPEARS TO BE IN PLACE FOR FRIDAY AS WELL. 1000-700MB FLOW IS MODERATE (~10KNOTS) FROM THE SOUTHEAST...AND WITH SIMILAR MOISTURE THROUGH THE COLUMN WITH SHOW EARLY/MID AFTERNOON CONVECTION OVER THE SOUTHERN ZONES SPREADING NORTH WITH TIME. THOSE WITH FRIDAY AFTERNOON/EVENING PLANS OUTDOORS SHOULD BE PREPARED TO DEAL WITH AT LEAST A BRIEF PERIOD OF RAIN/LIGHTNING. THE SYNOPTIC FLOW REGIME LOOKS TO FAVOR THE FLORIDA WEST COAST SEA BREEZE FOR CONVECTIVE COVERAGE INTO THE UPCOMING WEEKEND. && .MID TERM (FRIDAY-SATURDAY)... AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD OVER THE SOUTHEASTERN U.S. ON SATURDAY WITH A REINFORCING SURFACE HIGH BEGINNING TO SINK SOUTHWARD FROM THE NORTH. EAST TO SOUTHEAST WINDS CONTINUE FOR SATURDAY AFTERNOON...AND STILL EXPECTING A CHANCE FOR RAIN THROUGH THE AFTERNOON AND EVENING HOURS WITH SEA BREEZE AND OUTFLOW BOUNDARY INTERACTIONS. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL VALUES. .LONG TERM (SATURDAY NIGHT-WEDNESDAY)... THE UPPER-LEVEL HIGH WILL CONTINUE TO BUILD OVER THE REGION WITH SURFACE HIGH PRESSURE RIDGING ACROSS THE AREA FROM THE NORTH FOR THE START OF THE LONG TERM PERIOD. EASTERLY WINDS WILL REMAIN IN PLACE FOR SATURDAY NIGHT INTO SUNDAY...WITH SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS EXPECTED SUNDAY ALONG SEA BREEZE AND OUTFLOW BOUNDARIES. THE SURFACE HIGH WILL DRIFT SOUTHWARD EARLY NEXT WEEK...WITH MODELS SHOWING SOME DRIER AIR WORKING SOUTHWARD AS WELL. BACKGROUND EASTERLY WINDS WILL CONTINUE AND WILL STILL SHOW AT LEAST A SLIGHT CHANCE OF RAIN FOR MOST AREAS EACH DAY...AND MORE OF A CHANCE FOR THE SOUTH WHERE THE INFLUENCE OF DRIER AIR WILL BE LESS. TEMPERATURES WILL REMAIN NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION... SHOWERS AND STORMS ARE BEGINNING TO FILL IN THE AREA WITH SOUTHERN TERMINALS OF KRSW TO KPGD ALREADY BEING AFFECTED. CONVECTIVE COVERAGE FOR THESE AREAS SHOULD DIMINISH BY EARLY EVENING WHILE STORMS WORK THEIR WAY NORTHWARD TO THE TAMPA BAY AREA TERMINALS. WITHIN A FEW HOURS OF SUNSET THE ACTIVITY SHOULD DIMINISH AND RESULT IN A QUIET OVERNIGHT PERIOD WITH MAINLY VFR CONDITIONS. MORE AFTERNOON AND EVENING STORMS WILL FIRE UP ON FRIDAY WITH A GOOD CHANCE TO SEE A STORM AT EACH TERMINAL. && .MARINE... HIGH PRESSURE IN THE ATLANTIC CONTINUES TO RIDGE OVER FLORIDA INTO THE GULF WATERS PRODUCING SOUTHEAST WINDS IN THE 8 TO 12 KNOT RANGE. WINDS ALONG THE COAST WILL VEER AROUND TO THE SOUTH SOUTHWEST EACH AFTERNOON WITH THE ONSET OF THE SEA BREEZE. SEAS WILL REMAIN LESS THAN 2 FEET THROUGH THE REMAINDER OF THE WEEK. THE MAIN MARINE CONCERN WILL BE SCATTERED AFTERNOON AND EVENING THUNDERSTORMS PRODUCING BRIEF GUSTY WINDS AND HIGHER SEAS. && .FIRE WEATHER... THE WEATHER PATTERN WILL NOT CHANGE MUCH OVER THE NEXT SEVERAL DAYS. MOIST LOWER LEVELS WILL PREVENT RELATIVE HUMIDITY FROM REACHING CRITICAL LEVELS...AND NO SIGNIFICANT FIRE WEATHER CONCERNS ARE ANTICIPATED. EXPECT TYPICAL AFTERNOON STORMS TO DEVELOP EACH DAY AS WELL...WITH RAIN CHANCES REMAINING AT OR ABOVE SEASONAL NORMALS THROUGH THE WEEKEND. FOG POTENTIAL...PATCHY GROUND FOG WILL BE POSSIBLE LATE EACH NIGHT INTO THE EARLY MORNING HOURS EACH DAY. && .PRELIMINARY POINT TEMPS/POPS... TPA 75 88 74 88 / 50 50 40 50 FMY 72 91 72 91 / 30 70 20 50 GIF 72 89 71 89 / 30 40 30 50 SRQ 72 89 71 88 / 50 50 30 50 BKV 69 88 68 89 / 50 50 40 50 SPG 76 87 75 89 / 50 40 40 40 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA MID TERM/LONG TERM...CARLISLE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
950 AM EDT THU MAY 29 2014 .UPDATE... 13Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A NORTHERN STREAM FLOW ARRIVING OVER THE PACIFIC NORTHWEST AROUND THE BASE OF A SHARP TROUGH AXIS BEFORE RIDGING BACK TO THE NORTH THROUGH SOUTH-CENTRAL CANADA. THE FLOW THEN DROPS BACK TO THE SOUTHEAST THROUGH THE GREAT LAKES AND THEN OFF THE NEW ENGLAND COAST. THE OTHER FEATURE OF NOTE IS A CUT-OFF UPPER LOW STALLED NEAR THE BASE OF THE NORTHERN STREAM RIDGE OVER THE SOUTHERN MS VALLEY. THIS FEATURE WILL NEVER REALLY HAVE A SIGNIFICANT INFLUENCE ON OUR LOCAL WEATHER AS IT SPINS AND PLACE AND SLOWLY FILLS DURING THE NEXT 24-48 HOURS. 29/12Z KTBW SOUNDING SHOWS A SEASONABLE PROFILE WITH A PW VALUES OF JUST UNDER 1.5". MID-LEVEL TEMPS ARE A BIT ON THE COOL SIDE WITH A MEASURED 500MB TEMP AROUND -11C. THIS IS ABOUT A DEGREE COOLER THAN THE NAM/GFS FORECAST. A DEGREE DOES NOT SOUND LIKE MUCH...BUT CAN BE ALL THE DIFFERENCE IN THE WORLD OF A RISING AIR PARCEL. EITHER WAY...-11C IS ON THE COOL SIDE AND SHOULD HELP SUPPORT AFTERNOON/EVENING STORM DEVELOPMENT...AT LEAST INITIALLY UNTIL LATENT HEAT RELEASE FROM THE EARLY CONVECTION BEGINS TO CONTAMINATE THE OVERALL COLUMN. AT THE SURFACE...THE FL PENINSULA RESIDES ON THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE AXIS PROVIDING A GENERAL SOUTHEAST FLOW PATTERN IN THE 1000-700MB LAYER. AS LONG AS THE COLUMN IS NOT TOO DRY (WHICH IT IS NOT)...THEN THIS FLOW PATTERN TENDS TO BE WET ONE IN TERMS OF STORMS COVERAGE THROUGH THE COURSE OF THE DAY. CLIMATOLOGY UNDER THIS FLOW WOULD SUGGEST THAT INITIALLY THE BEST STORM CHANCES WILL BE DOWN ACROSS THE SOUTHERN PART OF THE FORECAST AREA...FT MYERS TO PUNTA GORDA...WITH THE FUTURE DEVELOPMENT "RIPPLING" UP THE SEA-BREEZE TOWARD TAMPA BAY AND THE NATURE COAST DURING THE LATER AFTERNOON AND ESPECIALLY EARLY EVENING HOURS. LOCAL WRFARW ENSEMBLES ALSO AGREE WITH THIS SOLUTION...AND HAVE UPDATED THE SPATIAL AND TEMPORAL EVOLUTION OF THE STORM PATTERN IN THE FORECAST GRIDS TO MATCH THIS PHILOSOPHY. LOCAL HIRES ARW SOLUTIONS ARE ALSO INDICATING MAXIMUM UPDRAFT VELOCITIES BETWEEN 14-16 M/S. THIS VALUES ARE NOT OVERLY IMPRESSIVE...BUT ENOUGH TO SUPPORT A FEW STRONGER STORMS. THESE UPDRAFT VELOCITY VALUES OBVIOUSLY ARE NOT PERFECT...IN TERMS OF EXACT VALUES OR LOCATIONS...BUT DO GIVE A GOOD REPRESENTATION OF ATMOSPHERIC POTENTIAL. THE SW FLOW PATTERN USUALLY HAS AN EARLIER ENDING TO THE SOUTH OF TAMPA BAY AND A LATER ENDING FROM TAMPA BAY NORTHWARD. SO...KEEP RAIN CHANCES IN FOR THE NORTHERN ZONES THROUGH 10-11 PM AND THEN WIND EVERYTHING DOWN. THIS WILL GIVE US A GENERALLY QUIET OVERNIGHT PERIOD. THE SYNOPTIC PATTERN AND STORMS SETUP LOOKS VERY SIMILAR FOR FRIDAY...SO APPEARS THAT WE WILL DO IT ALL OVER AGAIN TOMORROW. && .AVIATION... VFR CONDITIONS PREVAIL ACROSS THE REGION THIS MORNING. A SCT-BKN CUMULUS FIELDS WILL DEVELOP INTO THE EARLY AFTERNOON WHICH WILL GIVE WAY TO A SCATTERING OF THUNDERSTORMS BY THE SECOND HALF OF THE AFTERNOON. THREAT FOR STORMS SHOULD FIRST EXIST AROUND KFMY/KRSW DURING THE MIDDLE AFTERNOON AND THEN SPREAD UP THE COAST TOWARD THE TAMPA BAY TERMINALS BY THE EARLY EVENING HOURS. SHOWERS AND STORMS SHIFT SHIFT NORTH AND WEST OF THE TERMINALS WITHIN A FEW HOURS OF SUNSET ALLOWING FOR GENERAL VFR CONDITIONS TO PREVAIL FOR THE MAJORITY OF THE OVERNIGHT. && .MARINE... HIGH PRESSURE IN THE ATLANTIC CONTINUES TO RIDGE OVER FLORIDA INTO THE GULF WATERS PRODUCING SOUTHEAST WINDS IN THE 8 TO 12 KNOT RANGE. WINDS ALONG THE COAST WILL VEER AROUND TO THE SOUTH SOUTHWEST EACH AFTERNOON WITH THE ONSET OF THE SEA BREEZE. SEAS WILL REMAIN LESS THAN 2 FEET THROUGH THE REMAINDER OF THE WEEK. THE MAIN MARINE CONCERN WILL BE SCATTERED AFTERNOON AND EVENING THUNDERSTORMS PRODUCING BRIEF GUSTY WINDS AND HIGHER SEAS. && .PRELIMINARY POINT TEMPS/POPS... TPA 88 72 89 74 / 60 50 60 40 FMY 91 71 90 72 / 60 30 60 40 GIF 91 71 90 71 / 60 30 60 30 SRQ 87 71 87 71 / 60 50 40 40 BKV 89 67 89 68 / 60 50 60 40 SPG 88 75 88 75 / 60 50 50 40 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/AVIATION...MROCZKA MARINE...WYNN/PERRINI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
913 AM EDT THU MAY 29 2014 .DISCUSSION... A GREATER CHANCE FOR SHOWER AND THUNDERSTORM ACTIVITY WILL EXIST ACROSS THE AREA TODAY AS RIDGE ALOFT CONTINUES TO BREAK DOWN AND MOISTURE INCREASES IN A LOW LEVEL S/SE FLOW. 10Z SOUNDING FROM THE CAPE ALREADY SHOWS A MORE MOIST COLUMN WITH PW VALUES UP TO 1.7 INCHES. ALSO LATEST SATELLITE IMAGERY SHOWS FEW CLOUDS OVER THE REGION INITIALLY THIS MORNING WHICH WILL LEAD TO MORE THAN SUFFICIENT INSTABILITY INTO THE AFTERNOON FOR SCATTERED THUNDERSTORM DEVELOPMENT...ESPECIALLY OVER THE INTERIOR. CONVECTION SHOULD START TO INCREASE ALONG THE TREASURE COAST WITH ADDITIONAL SHOWERS AND STORMS FORMING FARTHER NORTH AND INLAND THROUGH THE AFTERNOON. GREATEST COVERAGE EXPECTED OVER THE INTERIOR...ESPECIALLY NEAR TO WEST OF THE I-4 CORRIDOR LATER IN THE DAY WHERE SEA BREEZE INTERACTIONS ARE MORE LIKELY. HAVE INCREASED RAIN CHANCES UP TO 30-40% ALONG THE TREASURE COAST BASED ON LATEST RADAR TRENDS AND OUTPUT FROM THE HRRR AND LOCAL WRF. OTHERWISE RAIN CHANCES REMAIN THE SAME...RANGING FROM 20 PERCENT ALONG THE BREVARD AND VOLUSIA COAST UP TO 50-60 PERCENT OVER THE INTERIOR. A FEW STRONG STORMS WILL ONCE AGAIN BE POSSIBLE WITH STRONG WIND GUSTS...SMALL HAIL...FREQUENT LIGHTNING AND LOCALLY HEAVY RAINFALL THE MAIN THREATS. INCREASING CLOUD COVER EXPECTED INTO THE AFTERNOON AS CONVECTION CONTINUES TO DEVELOP. THIS MAY LEAD TO MAX TEMPS A SLIGHTLY LOWER OVER THE INTERIOR TODAY. CURRENTLY HAVE HIGHS FORECAST FOR THE UPPER 80S/AROUND 90 INLAND WITH MID-UPPER 80S ALONG THE COAST. && .AVIATION...MAINLY VFR THROUGH THIS MORNING THEN TEMPO IFR/MVFR CONDS IN INCREASING SHOWER AND THUNDERSTORM ACTIVITY ALONG AND INLAND OF THE EAST COAST SEA BREEZE THROUGH THE AFTERNOON. HIGHEST COVERAGE EXPECTED OVER THE INTERIOR...ESPECIALLY NEAR TO WEST OF KMCO LATER IN THE DAY WHERE SEA BREEZE INTERACTIONS WILL BE MOST LIKELY. CONVECTION WILL WIND DOWN OVER THE INTERIOR THIS EVENING WITH VFR CONDITIONS EXPECTED OVERNIGHT. && .MARINE... TODAY-TONIGHT...SURFACE RIDGE AXIS REMAINS JUST NORTH OF THE AREA. EAST TO SOUTHEAST WINDS 5 TO 10 KNOTS EARLY THEN INCREASING TO 10 TO 15 KNOTS IN THE AFTERNOON DUE TO SEA BREEZE CONTRIBUTIONS. WINDS VEER TO THE SOUTH TO SOUTHEAST TONIGHT AND AVERAGE 10 TO 15 KNOTS. SEAS RANGING FROM 1-2 FEET. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ WEITLICH/KELLY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1022 PM EDT FRI MAY 30 2014 .SYNOPSIS... A SLOW MOVING FRONTAL SYSTEM WILL SLOWLY MOVE INTO THE MIDLANDS DURING THE OVERNIGHT HOURS. THE FRONT WILL BE JUST SOUTH OF THE AREA SATURDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... THE UPPER-LEVEL LOW WILL REMAIN IN THE LOWER MISSISSIPPI RIVER VALLEY THROUGH TONIGHT. AN EAST-WEST ORIENTED FRONTAL SYSTEM NEAR THE NC/SC BORDER WILL SLOWLY MOVE INTO THE MIDLANDS DURING THE EARLY MORNING HOURS. CONVERGENCE ASSOCIATED WITH THE FRONT MAY PROVIDE A TRIGGER FOR POSSIBLE THUNDERSTORMS OVERNIGHT. AS OF LATE THIS EVENING...MOST OF THE FORECAST AREA REMAINS DRY WITH SOME ISOLATED CONVECTION IN THE CSRA. WILL CONTINUE GENERALLY SLIGHT CHANCE/LOW CHANCE POPS INTO THE OVERNIGHT HOURS. OVERNIGHT LOWS WILL BE IN THE MIDDLE TO UPPER 60S. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... WEAK SURFACE COLD FRONT WILL CONTINUE SLOWLY SOUTHWARD ACROSS THE FORECAST AREA SATURDAY...PUSHING INTO SOUTHERN GEORGIA SATURDAY NIGHT. GFS HOLDS ON TO 1.75 PRECIPITABLE WATER VALUES INTO LATE SATURDAY NIGHT WHILE THE NAM DRIES OUT A LITTLE QUICKER. FRONTAL FORCING WITH POSSIBLE RESIDUAL OUTFLOW BOUNDARY INTERACTION WILL PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY EVENING MAINLY SOUTH OF I-20 SOUTH AND WEST OF I-26. CURRENT POPS LOOK GOOD WITH 30-40 POPS ACROSS CENTRAL AND SOUTHERN PORTIONS...20 OR LESS NORTH. SPC HAS THIS REGION IN GENERAL THUNDER SO NOT EXPECTING STORMS TO REACH SEVERE LEVELS. HOWEVER WITH WEAK WINDS ALOFT PERSISTING AND RESULTING SLOW MOVING CELLS...THE POTENTIAL FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE. NEAR NORMAL TEMPERATURES IN THE MIDDLE 80S FOR AFTERNOON HIGHS WITH OVERNIGHT LOWS IN THE MIDDLE 60S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... UPPER LEVEL RIDGING ACROSS THE EASTERN US WILL DOMINATE EARLY IN THE PERIOD BEFORE FLATTENING OUT IN RESPONSE TO A SERIES OF TROFS SWEEPING EAST ACROSS THE NORTHEASTERN US STARTING MID WEEK. MAINLY DRY SUNDAY THROUGH TUESDAY UNDER RIDGE. WEAK SURFACE FRONT APPROACHES FORECAST AREA LATE TUESDAY INCREASING POPS BY MID WEEK. RIBBON OF GULF MOISTURE ON WEST SIDE OF HIGH JUST OFF SE COAST WILL AID IN CONVECTION DEVELOPMENT ALONG FRONTAL BOUNDARY. MODELS HINT AT WEAKENING FRONT SO SHOWER AND THUNDERSTORM ACTIVITY PROBABLY LIMITED AS FRONT MOVES ACROSS FORECAST AREA LATE TUESDAY INTO WEDNESDAY. OTHERWISE FORECAST AREA STAYS IN LIGHT UPPER FLOW THROUGH THE EXTENDED PERIOD AS MAIN TROF ENERGY STAYS WELL NORTH. SCATTERED DIURNALLY DRIVEN CONVECTION FROM THURSDAY ON. NEAR NORMAL TEMPERATURES FIRST HALF OF THE PERIOD...WARMING TO SLIGHTLY ABOVE NORMAL SECOND HALF. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... AN EAST-WEST ORIENTED FRONTAL SYSTEM ALONG THE NORTH CAROLINA/SOUTH CAROLINA BORDER WILL MOVE SLOWLY SOUTH OVERNIGHT AND SATURDAY. THE FRONT WILL BE A FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS. THE HRRR SUPPORTS THE GREATEST THUNDERSTORM CHANCE IN THE CSRA THIS EVENING...BUT BASED ON RADAR TRENDS THESE STORMS SHOULD REMAIN TO THE NORTHWEST OF AGS/DNL TERMINALS. ELSEWHERE...WITH FRONT REMAINING TO THE NORTH THROUGH THE EARLY EVENING...CHANCE THUNDERSTORMS APPEARS LOW WITH LITTLE IN THE WAY OF FORCING. HIGH-LOW LEVEL MOISTURE OVERNIGHT/NOCTURNAL COOLING AND FRONTAL BOUNDARY SUPPORTS STRATUS AND OR FOG DEVELOPMENT AFTER 06Z...SO EXPECT MVFR/IFR CONDITIONS OVERNIGHT. FRONT WILL BE MOVING THROUGH THE AREA SATURDAY AND FOCUS MAY BE SHIFTING SOUTH DURING THE AFTERNOON...SO BETTER CHANCE AFTERNOON STORMS APPEARS TO BE IN THE CSRA. VFR DEVELOPING BY LATE MORNING AND RESTRICTIONS MAINLY NEAR CONVECTION. EXTENDED AVIATION OUTLOOK...MOISTURE ASSOCIATED WITH THE REMNANTS OF A STALLED FRONT WILL CONTINUE DURING MUCH OF THE OUTLOOK PERIOD. EXPECT RESTRICTIONS AT TIMES MAINLY FROM AFTERNOON AND EVENING THUNDERSTORMS AND EARLY MORNING STRATUS AND FOG. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
751 PM EDT FRI MAY 30 2014 .SYNOPSIS... A SLOW MOVING FRONTAL SYSTEM REMAIN JUST NORTH OF THE FORECAST AREA INTO THE OVERNIGHT HOURS. THE FRONT WILL BE JUST SOUTH OF THE AREA SATURDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... THE UPPER-LEVEL LOW WILL REMAIN IN THE LOWER MISSISSIPPI RIVER VALLEY THROUGH TONIGHT. FARTHER EAST...OUR REGION WILL BE UNDER A WEAK RIDGE. THE MODELS INDICATE A SHORTWAVE TROUGH CAUGHT IN THIS RIDGE NEAR THE FORECAST AREA. THE LATEST ANALYSIS SHOWED H5 TEMPERATURES RELATIVELY COLD AROUND -8 C....WHICH IS A BIT WARMER THAN YESTERDAY. AN EAST- WEST ORIENTED FRONTAL SYSTEM WILL REMAIN JUST NORTH OF THE FORECAST AREA TONIGHT. CONVERGENCE ASSOCIATED WITH THE FRONT WILL PROVIDE A TRIGGER FOR POSSIBLE THUNDERSTORMS. EARLY THIS EVENING...MOST OF THE FORECAST AREA REMAINS DRY WITH SOME WIDELY SCATTERED CONVECTION IN THE CSRA. LITTLE MOVEMENT WILL OCCUR BECAUSE OF THE UPPER-LEVEL RIDGE SO EXPECT LIMITED THUNDERSTORM COVERAGE. THE MAIN FORECAST PROBLEM WILL BE THUNDERSTORMS WITH THE POTENTIAL FOR HEAVY RAIN BECAUSE OF PRECIPITABLE WATER NEAR 1.8 OF AN INCH AND SLOW STORM MOVEMENT. NEAR-SEVERE WIND GUSTS MAY OCCUR BECAUSE OF HEAVY PRECIPITATION LOADING. WILL CONTINUE GENERALLY LOW CHANCE POPS INTO THE OVERNIGHT HOURS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... WEAK SURFACE COLD FRONT WILL CONTINUE SLOWLY SOUTHWARD ACROSS THE FORECAST AREA SATURDAY...PUSHING INTO SOUTHERN GEORGIA SATURDAY NIGHT. GFS HOLDS ON TO 1.75 PRECIPITABLE WATER VALUES INTO LATE SATURDAY NIGHT WHILE THE NAM DRIES OUT A LITTLE QUICKER. FRONTAL FORCING WITH POSSIBLE RESIDUAL OUTFLOW BOUNDARY INTERACTION WILL PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY EVENING MAINLY SOUTH OF I-20 SOUTH AND WEST OF I-26. CURRENT POPS LOOK GOOD WITH 30-40 POPS ACROSS CENTRAL AND SOUTHERN PORTIONS...20 OR LESS NORTH. SPC HAS THIS REGION IN GENERAL THUNDER SO NOT EXPECTING STORMS TO REACH SEVERE LEVELS. HOWEVER WITH WEAK WINDS ALOFT PERSISTING AND RESULTING SLOW MOVING CELLS...THE POTENTIAL FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE. NEAR NORMAL TEMPERATURES IN THE MIDDLE 80S FOR AFTERNOON HIGHS WITH OVERNIGHT LOWS IN THE MIDDLE 60S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... UPPER LEVEL RIDGING ACROSS THE EASTERN US WILL DOMINATE EARLY IN THE PERIOD BEFORE FLATTENING OUT IN RESPONSE TO A SERIES OF TROFS SWEEPING EAST ACROSS THE NORTHEASTERN US STARTING MID WEEK. MAINLY DRY SUNDAY THROUGH TUESDAY UNDER RIDGE. WEAK SURFACE FRONT APPROACHES FORECAST AREA LATE TUESDAY INCREASING POPS BY MID WEEK. RIBBON OF GULF MOISTURE ON WEST SIDE OF HIGH JUST OFF SE COAST WILL AID IN CONVECTION DEVELOPMENT ALONG FRONTAL BOUNDARY. MODELS HINT AT WEAKENING FRONT SO SHOWER AND THUNDERSTORM ACTIVITY PROBABLY LIMITED AS FRONT MOVES ACROSS FORECAST AREA LATE TUESDAY INTO WEDNESDAY. OTHERWISE FORECAST AREA STAYS IN LIGHT UPPER FLOW THROUGH THE EXTENDED PERIOD AS MAIN TROF ENERGY STAYS WELL NORTH. SCATTERED DIURNALLY DRIVEN CONVECTION FROM THURSDAY ON. NEAR NORMAL TEMPERATURES FIRST HALF OF THE PERIOD...WARMING TO SLIGHTLY ABOVE NORMAL SECOND HALF. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... AN EAST-WEST ORIENTED FRONTAL SYSTEM ALONG THE NORTH CAROLINA/SOUTH CAROLINA BORDER WILL MOVE SLOWLY SOUTH OVERNIGHT AND SATURDAY. THE FRONT WILL BE A FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS. THE HRRR SUPPORTS THE GREATEST THUNDERSTORM CHANCE IN THE CSRA THIS EVENING...BUT BASED ON RADAR TRENDS THESE STORMS SHOULD REMAIN TO THE NORTHWEST OF AGS/DNL TERMINALS. ELSEWHERE...WITH FRONT REMAINING TO THE NORTH THROUGH THE EARLY EVENING...CHANCE THUNDERSTORMS APPEARS LOW WITH LITTLE IN THE WAY OF FORCING. HIGH-LOW LEVEL MOISTURE OVERNIGHT/NOCTURNAL COOLING AND FRONTAL BOUNDARY SUPPORTS STRATUS AND OR FOG DEVELOPMENT AFTER 06Z...SO EXPECT MVFR/IFR CONDITIONS OVERNIGHT. FRONT WILL BE MOVING THROUGH THE AREA SATURDAY AND FOCUS MAY BE SHIFTING SOUTH DURING THE AFTERNOON...SO BETTER CHANCE AFTERNOON STORMS APPEARS TO BE IN THE CSRA. VFR DEVELOPING BY LATE MORNING AND RESTRICTIONS MAINLY NEAR CONVECTION. EXTENDED AVIATION OUTLOOK...MOISTURE ASSOCIATED WITH THE REMNANTS OF A STALLED FRONT WILL CONTINUE DURING MUCH OF THE OUTLOOK PERIOD. EXPECT RESTRICTIONS AT TIMES MAINLY FROM AFTERNOON AND EVENING THUNDERSTORMS AND EARLY MORNING STRATUS AND FOG. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
237 PM EDT THU MAY 29 2014 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTHWARD INTO THE NORTHERN PORTION OF SOUTH CAROLINA THIS EVENING...AND THEN CONTINUE SLOWLY SOUTHWARD INTO THE SOUTHERN PORTIONS OF THE AREA THROUGH FRIDAY NIGHT/EARLY SATURDAY. THIS FRONT WILL STALL JUST SOUTH OF THE AREA SUNDAY...WHILE DRIER AIR PUSHED INTO THE FORECAST AREA FROM THE NORTH TO START OFF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... THIS AFTERNOON...THE MAIN UPPER-LEVEL LOW WILL REMAIN IN THE LOWER MISSISSIPPI RIVER VALLEY WITH A RIDGE AXIS OVER THE FORECAST AREA. A SHORTWAVE TROUGH MAY BE CAUGHT IN THIS RIDGE. THE MAIN SURFACE FRONT WILL BE NEAR THE NORTH PART OF THE FORECAST AREA THIS AFTERNOON WITH CONVERGENCE OCCURRING AHEAD OF THE FRONT. THE PATTERN SUPPORTS SCATTERED THUNDERSTORMS WITH COVERAGE LIMITED BY SLOW MOVEMENT. THE HRRR INDICATES SCATTERED THROUGH THE AFTERNOON. WE HAVE CONTINUED THE FORECAST OF CHANCE POPS OVER MOST AREAS. EARLY AFTERNOON LAPS SOUNDINGS HAD PLENTY OF MOISTURE...WITH PRECIPITABLE WATER VALUES ABOVE 1.7 OF AN INCH. THE SOUNDINGS SHOWED STEEP LOW-LEVEL LAPSE RATES. HEAVY PRECIPITATION LOADING AND THE LAPSE RATES INDICATE A POTENTIAL FOR STRONG GUSTY DOWNBURST WINDS...WHILE THE MAIN WIND PATTERN REMAINS RELATIVELY WEAK ASSOCIATED WITH THE UPPER RIDGING WHICH SUPPORTS SLOW STORM MOVEMENT AND HEAVY RAIN. THE TEMPERATURE FORECAST IS ON TRACK WITH HIGHS AROUND 90. TONIGHT...CONVERGENCE ASSOCIATED WITH THE FRONT AND INTERACTING OUTFLOW BOUNDARIES SUPPORT A CONTINUED CHANCE OF THUNDERSTORMS TONIGHT. THE SPC AND CAE WRF INDICATE SIGNIFICANT COVERAGE MAINLY IN THE NORTH PART OF THE FORECAST AREA THROUGH LATE TONIGHT. HOWEVER...WE FORECASTED A LOWER POP LATE BECAUSE OF DIURNAL COOLING AND PREVIOUS CONVECTIVE OVERTURNING. THE TEMPERATURE GUIDANCE WAS CLOSE WITH LOWS IN THE UPPER 60S. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... UPPER LEVEL LOW WILL CONTINUE TO SLOWLY ERODE OVER THE WESTERN GULF STATES WITH THE WEAK FRONT ACROSS THE CENTRAL ATLANTIC STATES EDGING SOUTHWARD INTO THE AREA FRIDAY. THE FRONT THE SLOWLY TRACK THROUGH THE THE NORTHERN MIDLANDS ON FRIDAY...BE STRETCHED ACROSS THE CENTRAL MIDLANDS ON SATURDAY...FINALLY MOVING SOUTH OF THE AREA EARLY SATURDAY NIGHT. WITH THE FRONT MOVING INTO THE AREA ON FRIDAY AND INSTABILITY MODERATE EXPECT THUNDERSTORM COVERAGE TO THE THE HIGHEST SO FAR THIS WEEK. SEVERE THUNDERSTORM CONCERN FOR FRIDAY REMAINS LOW AS WET BULB ZERO HEIGHTS WILL BE AROUND 12 KFT AND FREEZING LEVELS OVER 13 KFT...HOWEVER WITH PWAT VALUES BEING 1.7 INCHES OR GREATER ACROSS THE CENTRAL MIDLANDS AND CSRA DAMAGING WINDS FROM PRECIPITATION LOADING WILL AGAIN BE POSSIBLE. LOCALIZED HEAVY RAINFALL WILL ALSO BE POSSIBLE AS WINDS THROUGH THE COLUMN WILL BE 20 KNOTS OR LESS. ON SATURDAY PWAT VALUES WILL BE 1.5 INCHES OR GREATER THROUGH THE CENTRAL MIDLANDS AND CSRA WITH DRIER AIR MOVING INTO THE NORTHERN MIDLANDS. THIS WILL CREATE ANOTHER ROUND OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WITH HIGHEST CHANCES OF CONVECTION ACROSS THE CSRA WHERE CONVERGENCE AHEAD OF THE FRONT WILL BE STRONGEST...WHILE DRIER AIR ENTERING THE NORTHERN MIDLANDS WILL HELP SUPPRESS CONVECTION. THE POTENTIAL FOR SEVERE THUNDERSTORMS WILL AGAIN BE LOW...HOWEVER WITH WEAK WINDS ALOFT PERSISTING AND RESULTING IN SLOW MOVING CELLS THE POTENTIAL FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE. TEMPERATURES WILL BE IN THE MIDDLE TO UPPER 80S FOR AFTERNOON HIGHS WITH OVERNIGHT LOWS IN THE MIDDLE TO UPPER 60S. && .LONG TERM /SUNDAY THROUGH THURSDAY/... MODELS ARE IN GOOD AGREEMENT AND HAVE BEEN CONSISTENT OVER THE PAST SEVERAL RUNS FOR THE LONG TERM. UPPER LEVEL RIDGING WILL BE OVER THE REGION THROUGH MONDAY WITH THE UPPER LEVEL PATTERN BECOMING MORE ZONAL FOR TUESDAY ONWARD. THE FRONT MOVE JUST SOUTH OF THE AREA SUNDAY AND STALL AS HIGH PRESSURE JUST OFFSHORE OF NC TAKES CONTROL OF THE AREA. THIS WILL KEEP DRIER AIR OVER THE FORECAST AREA FOR SUNDAY AND MONDAY WITH MOISTURE RETURNING TO THE AREA MONDAY NIGHT AS THE NEXT COLD FRONT TRACKS TOWARD THE AREA FROM THE WEST. THIS WILL BRING CHANCES OF SHOWERS AND THUNDERSTORMS BACK INTO THE FORECAST FOR TUESDAY AND WEDNESDAY. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... A COLD FRONT APPROACHING FROM THE NORTH WILL BE IN THE AREA TONIGHT. CONVERGENCE ASSOCIATED WITH THE FRONT WILL SUPPORT THUNDERSTORMS BUT COVERAGE WILL BE LIMITED BECAUSE OF UPPER-LEVEL RIDGING AND SLOW STORM MOVEMENT. HIGH PRECIPITABLE WATER AND PRECIPITATION LOADING PLUS STEEP LOW-LEVEL LAPSE RATES MAY SUPPORT STRONG GUSTY WINDS NEAR ANY THUNDERSTORMS. THE HIGH RESOLUTION MODELS SUPPORT SCATTERED COVERAGE. THE GREATEST COVERAGE WILL LIKELY BE NEAR MAXIMUM HEATING. CONVERGENCE ASSOCIATED WITH THE FRONT WILL SUPPORT A CONTINUED CHANCE THROUGH TONIGHT. HIGH LOW- LEVEL MOISTURE MAY LEAD TO STATUS AND FOG DURING THE EARLY MORNING HOURS. THE GFS MOS AND LAMP PLUS NAM MOS WERE CONSISTENT INDICATING IFR OR MVFR FOG AT THE RIVER VALLEY TERMINALS OF AGS AND DNL. EXTENDED AVIATION OUTLOOK...MOISTURE ASSOCIATED WITH THE REMNANTS OF A STALLED FRONT WILL CONTINUE DURING MUCH OF THE OUTLOOK PERIOD. EXPECT RESTRICTIONS AT TIMES MAINLY FROM AFTERNOON AND EVENING THUNDERSTORMS AND EARLY MORNING STRATUS AND FOG. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
142 PM EDT THU MAY 29 2014 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTHWARD INTO THE NORTHERN PORTION OF SOUTH CAROLINA THIS EVENING...AND THEN CONTINUE SLOWLY SOUTHWARD INTO THE SOUTHERN PORTIONS OF THE AREA THROUGH FRIDAY NIGHT/EARLY SATURDAY. THIS FRONT WILL STALL JUST SOUTH OF THE AREA SUNDAY...WHILE DRIER AIR PUSHED INTO THE FORECAST AREA FROM THE NORTH TO START OFF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... THIS AFTERNOON...THE MAIN UPPER-LEVEL LOW WILL REMAIN IN THE LOWER MISSISSIPPI RIVER VALLEY WITH A RIDGE AXIS OVER THE FORECAST AREA. A SHORTWAVE TROUGH MAY BE CAUGHT IN THIS RIDGE. THE MAIN SURFACE FRONT WILL BE NEAR THE NORTH PART OF THE FORECAST AREA THIS AFTERNOON WITH CONVERGENCE OCCURRING AHEAD OF THE FRONT. THE PATTERN SUPPORTS SCATTERED THUNDERSTORMS WITH COVERAGE LIMITED BY SLOW MOVEMENT. THE HRRR INDICATES SCATTERED THROUGH THE AFTERNOON. WE HAVE CONTINUED THE FORECAST OF CHANCE POPS OVER MOST AREAS. EARLY AFTERNOON LAPS SOUNDINGS HAD PLENTY OF MOISTURE...WITH PRECIPITABLE WATER VALUES ABOVE 1.7 OF AN INCH. THE SOUNDINGS SHOWED STEEP LOW-LEVEL LAPSE RATES. HEAVY PRECIPITATION LOADING AND THE LAPSE RATES INDICATE A POTENTIAL FOR STRONG GUSTY DOWNBURST WINDS...WHILE THE MAIN WIND PATTERN REMAINS RELATIVELY WEAK ASSOCIATED WITH THE UPPER RIDGING WHICH SUPPORTS SLOW STORM MOVEMENT AND HEAVY RAIN. THE TEMPERATURE FORECAST IS ON TRACK WITH HIGHS AROUND 90. TONIGHT...CONVERGENCE ASSOCIATED WITH THE FRONT AND INTERACTING OUTFLOW BOUNDARIES SUPPORT A CONTINUED CHANCE OF THUNDERSTORMS TONIGHT. THE SPC AND CAE WRF INDICATE SIGNIFICANT COVERAGE MAINLY IN THE NORTH PART OF THE FORECAST AREA THROUGH LATE TONIGHT. HOWEVER...WE FORECASTED A LOWER POP LATE BECAUSE OF DIURNAL COOLING AND PREVIOUS CONVECTIVE OVERTURNING. THE TEMPERATURE GUIDANCE WAS CLOSE WITH LOWS IN THE UPPER 60S. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... UPPER LEVEL LOW ACROSS THE WESTERN GULF STATES WILL REMAIN QUASI- STATIONARY THROUGH FRIDAY NIGHT WITH THE UPPER LEVEL TROUGH JUST OFFSHORE OF THE EAST COAST DIGS SOUTHWARD. FRONTAL BOUNDARY WILL CONTINUE SLOWLY PUSHING INTO THE SOUTHERN CWA THROUGH FRIDAY...BEFORE STALLING OUT IN THE SOUTH FRIDAY NIGHT INTO SATURDAY MORNING. THE PROXIMITY TO THE FRONT WILL ALLOW FOR A CONTINUATION OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS INTO SATURDAY. AFTERNOON TEMPERATURES WILL BE IN THE MID TO UPPER 80S BOTH DAYS...WHILE LOWS WILL FALL INTO THE MIDDLE TO UPPER 60S. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... MODELS ARE IN GOOD AGREEMENT THROUGH THE LONG TERM. THE CENTER OF AN UPPER LEVEL RIDGE THAT HAD BEEN ACROSS THE UPPER MID-WEST WILL SLIDE SOUTHEASTWARD...SETTLING OVER THE SOUTHEASTERN UNITED STATES BY SUNDAY. STRONG UPPER LOW WILL SPIN WELL OFF THE MID-ATLANTIC COAST. SURFACE HIGH PRESSURE AND SLIGHTLY DRIER AIR WILL DOMINATE INTO THE EARLY PART OF THE WEEK. MOISTURE BEGINS TO RETURN TO THE AREA ON TUESDAY INTO WEDNESDAY. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY BELOW NORMAL. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... A COLD FRONT APPROACHING FROM THE NORTH WILL BE IN THE AREA TONIGHT. CONVERGENCE ASSOCIATED WITH THE FRONT WILL SUPPORT THUNDERSTORMS BUT COVERAGE WILL BE LIMITED BECAUSE OF UPPER-LEVEL RIDGING AND SLOW STORM MOVEMENT. HIGH PRECIPITABLE WATER AND PRECIPITATION LOADING PLUS STEEP LOW-LEVEL LAPSE RATES MAY SUPPORT STRONG GUSTY WINDS NEAR ANY THUNDERSTORMS. THE HIGH RESOLUTION MODELS SUPPORT SCATTERED COVERAGE. THE GREATEST COVERAGE WILL LIKELY BE NEAR MAXIMUM HEATING. CONVERGENCE ASSOCIATED WITH THE FRONT WILL SUPPORT A CONTINUED CHANCE THROUGH TONIGHT. HIGH LOW- LEVEL MOISTURE MAY LEAD TO STATUS AND FOG DURING THE EARLY MORNING HOURS. THE GFS MOS AND LAMP PLUS NAM MOS WERE CONSISTENT INDICATING IFR OR MVFR FOG AT THE RIVER VALLEY TERMINALS OF AGS AND DNL. EXTENDED AVIATION OUTLOOK...MOISTURE ASSOCIATED WITH THE REMNANTS OF A STALLED FRONT WILL CONTINUE DURING MUCH OF THE OUTLOOK PERIOD. EXPECT RESTRICTIONS AT TIMES MAINLY FROM AFTERNOON AND EVENING THUNDERSTORMS AND EARLY MORNING STRATUS AND FOG. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
128 AM EDT THU MAY 29 2014 .UPDATE... /ISSUED AT 729 PM EDT WED MAY 28 2014/ OUTFLOW DRIVEN CONVECTION WILL CONTINUE ACROSS MUCH OF THE CWFA FOR THE NEXT FEW HOURS. HAVE UPDATED THE POPS ACCORDING TO THE LATEST RADAR TRENDS. ALSO...THE HRRR DOES KEEP SOME ISOLATED ACTIVITY IN AFTER 06Z...SO HAVE DONE THE SAME. && .PREV DISCUSSION... /ISSUED 341 PM EDT WED MAY 28 2014/ SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... NO SIGNIFICANT CHANGES TO THE GENERAL TRENDS THROUGH THE SHORT TERM FORECAST PERIOD. STRANDED UPPER LOW OVER THE LOWER MISSISSIPPI VALLEY GETS NO KICKER TO MOVE AS MEDIUM RANGE MODELS SHOW IT DOES NOT CONNECT WITH THE EAST COAST UPPER TROUGH BEFORE THE BUILDING UPPER RIDGE ISOLATES IT ONCE AGAIN. ISOLATED TO SCATTERED DIURNAL CONVECTION PATTERN WILL CONTINUE THROUGH THURSDAY NIGHT. INDICATIONS ARE THAT MID-LEVEL LAPSE RATES SLOWLY DECREASE THROUGH THE PERIOD SO CHANCES FOR STRONG TO SEVERE THUNDERSTORMS...ALTHOUGH NOT ZERO... REMAIN SMALL AND SHOULD ACTUALLY DIMINISH SOME AGAIN THURSDAY. OVERNIGHT LOWS ARE EXPECTED TO REMAIN MILD AND NEAR SEASONAL NORMALS WITH AFTERNOON HIGHS AT OR SLIGHTLY ABOVE AVERAGE. 20 LONG TERM /FRIDAY THROUGH WEDNESDAY/... LONG TERM FORECAST STILL LOOKS VERY SIMILAR WITH PULSE THUNDERSTORM CONVECTION EACH DAY THROUGH SATURDAY BUT LOSING SOME INSTABILITY FOR SUNDAY INTO MONDAY AS A WEDGE HELPS TO STABILIZE THE AREA. CURRENT LONG TERM FORECAST IS ON TRACK SO VERY LITTLE IN TERMS OF CHANGES. THE PREVIOUS DISCUSSION FOLLOWS. 11 /ISSUED AT 358 AM EDT WED MAY 28 2014/ MODELS ARE IN GOOD CONSENSUS THROUGH MUCH OF THE LONG TERM. WEAK UPPER LOW WITH A BROAD AND DEEP MOISTURE FIELD LINGERS ACROSS THE SOUTHEAST CONUS INTO THE WEEKEND ALLOWING FOR DECENT CHANCE POPS FOR SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND EVENING PERIODS THEN SOME CONTINUED WEAKER ACTIVITY POSSIBLE OVERNIGHT. LITTLE TO NO SHEAR WITH MODERATE INSTABILITY WILL KEEP CONVECTIVE MODE OF THE PULSE VARIETY WITH EVOLUTION LARGELY OUTFLOW DRIVEN OR RIDING ALONG WAVES OF GULF MOISTURE FROM THE SOUTHWEST. SOME STRONG AND FEW SEVERE STORMS STILL LOOK LIKE A GOOD BET AS HAS BEEN THE RECENT TREND. UPPER RIDGING BEGINS TO TAKE OVER SATURDAY INTO SUNDAY AND A SFC HIGH SLIDING SOUTH ALONG THE EAST COAST LOOKS TO RESULT IN HYBRID CAD. THE WEDGE FRONT LATER SATURDAY MAY PROVIDE SOME ENHANCED FORCING AND FOCUS FOR CONVECTION. WHILE THE CAD LOOKS TO BE SHORT-LIVED AS THE PARENT HIGH SLIDES EVENT FARTHER SOUTH...THE RIDGING SHOULD STILL SERVE TO STABILIZE MUCH OF THE AREA FROM THE EAST AND LESSEN SHOWER/STORM POTENTIAL SUNDAY THROUGH MONDAY. BETTER STORM CHANCE STARTS TO RETURN TO THE AREA BY TUESDAY AS THE RIDGE BREAKS DOWN. FOR TEMPS...MADE SLIGHT ADJUSTMENTS FROM A GENERAL BLEND OF GUIDANCE AND VALUES GENERALLY 5 DEGREES ABOVE NORMAL LOOK REASONABLE. SLIGHTLY COOLER TEMPS ON TAP SUNDAY AND MONDAY FROM BRIEF WEDGE. BAKER && .AVIATION... 06Z UPDATE... ISOLATED CONVECTION CONTINUES OVER NORTH GA BUT THIS SHOULD DISSIPATE BY 09Z AND SHOULD NOT MOVE OVER ANY OF THE TAF SITES. AREAS OF FOG WILL DEVELOP IN AHN/MCN/PDK/FTY WHERE RAIN FELL OVER OR IN THE VICINITY OF THE AIRPORT DURING YESTERDAY EVENING. MUCH OF THE SAME FOR LATER TODAY WITH CU FIELD FORMING AND SCATTERED CONVECTION DEVELOPING DURING THE LATE MORNING AND AFTERNOON...DIMINISHING DURING THE EVENING. WILL MAINTAIN A PROB30 TSRA FOR THE AFTERNOON ALL LOCATIONS. WINDS WILL REMAIN CALM/NEAR CALM EARLY THIS MORNING...THEN SOUTHWEST LESS THAN 10 KTS THROUGH THE REST OF TODAY. //ATL CONFIDENCE...06Z UPDATE... HIGH CONFIDENCE ON ALL ELEMENTS. && .PRELIMINARY POINT TEMPS/POPS... ATHENS 65 88 64 88 / 40 40 40 40 ATLANTA 67 85 67 86 / 50 40 30 40 BLAIRSVILLE 59 83 61 82 / 40 40 40 40 CARTERSVILLE 63 86 63 87 / 50 40 30 40 COLUMBUS 68 88 67 88 / 40 40 30 40 GAINESVILLE 66 86 66 86 / 40 40 40 40 MACON 65 88 65 88 / 70 40 30 40 ROME 64 86 63 87 / 50 40 30 40 PEACHTREE CITY 64 86 63 87 / 50 40 30 40 VIDALIA 69 90 69 90 / 70 40 30 40 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
106 PM CDT THU MAY 29 2014 .DISCUSSION... 1131 AM CDT MORNING UPDATE... MADE SOME MINOR TWEAKS TO GOING FORECAST...MAINLY TO ADJUST SKY TRENDS FOR EROSION OF STUBBORN LOW STRATUS OVER SOUTH AND SOUTHWEST CWA AND TO RAISE TEMPERATURES A FEW DEGREES IN SOME AREAS. DESPITE CWA BEING ON "COOL" SIDE OF STATIONARY FRONTAL BOUNDARY DRAPPED ACROSS CENTRAL ILLINOIS...AIR MASS IS STILL QUITE WARM AWAY FROM LAKE MICHIGAN INFLUENCE...WITH +14C AND +15C RESPECTIVELY ON 12Z DVN AND ILX RAOBS AT 850 MB. SOUNDINGS DON`T SHOW MIXING QUITE TO THIS LEVEL...BUT DRY ADIABATING MIXING TO 900 MB SHOULD YIELD LOW 80S MOST PLACES AWAY FROM THE LAKE AND SOME MID 80S FAR SOUTH WHERE IT IS ALREADY 80 AS OF 11AM AT TIP. ALONG IMMEDIATE LAKESHORE...MAINTAINED GOING HIGHS. NOT EXPECTING STRATUS TO SURGE INLAND LIKE LATE YESTERDAY...BUT ENHANCED LAKE COOLING SHOULD PUSH INLAND LATER TODAY. OTHER CONCERN IS FOR THUNDERSTORMS IN THE SOUTHERN CWA JUST TO THE NORTH OF STALLED BOUNDARY. DEWPOINTS HAVE REMAINED WELL INTO THE 60S AND MODIFYING THE MORNING ILX SOUNDING FOR CURRENT CONDITIONS OUTSIDE THE STRATUS DECK RESULTS IN VERY LITTLE IF ANY CAP REMAINING. GIVEN PRESENCE OF REMNANT SHORTWAVE FROM YESTERDAY AND STATIONARY BOUNDARY...AND POSSIBLE INFLUENCE OF DIFFERENTIAL HEATING AS LOW CLOUDS ERODE...COVERAGE COULD BE A BIT HIGHER THAN 20 POPS INDICATED IN GRIDS IN FAR SOUTHERN CWA. FOR NOW...HAVE MAINTAINED GOING POPS AS CONVECTION HAS STARTED TO FIRE IN AGITATED CU FIELD TO THE SOUTH IN THE ILX CWA. WILL CONTINUE TO MONITOR TRENDS. IF CONVECTION DOES BECOME MORE WIDESPREAD IN OUR FAR SOUTHERN COUNTIES...SIMILAR TO THE PAST FEW DAYS...THE MAIN THREAT WILL BE HEAVY RAIN DUE TO VERY SLOW STORM MOTIONS. RC //PREV DISCUSSION... 346 AM CDT FORECAST CONCERNS THIS MORNING FOCUS ON DRIER NORTHEAST LOW LEVEL WINDS TODAY...WITH DECREASING CLOUDINESS AND THREAT OF AFTERNOON THUNDERSTORMS SHIFTING DOWNSTATE ALONG/SOUTH OF WFO LOT/ILX BORDER. DRY AND MILD CONDITIONS ANTICIPATED OVER THE NEXT FEW DAYS WITH A WARMING TREND INTO THE WEEKEND...AND A GRADUAL DECREASE IN LAKE COOLING. A PERIOD OF ACTIVE WEATHER WITH HEAVY RAINFALL AND INCREASING SEVERE THUNDERSTORM POTENTIAL APPEARS TO BE SHAPING UP FOR DAYS 4-7 (SUNDAY-NEXT WEDNESDAY)...AS A COLD FRONT SAGS INTO WARM/HUMID AIR MASS WHICH TAKES UP RESIDENCE ACROSS THE AREA. WEAK SURFACE LOW PRESSURE CONTINUES TO SETTLE SOUTHWARD ACROSS EASTERN MISSOURI THIS MORNING...WITH A NEARLY STATIONARY COLD FRONT STRETCHING WEST-EAST ACROSS SOUTH CENTRAL IL/IN. THIS BOUNDARY WILL CONTINUE TO BE THE FOCUS FOR DIURNAL SHOWER/THUNDERSTORM DEVELOPMENT THIS AFTERNOON...AS WEAKENING SHEARED MID-LEVEL VORT MAXIMA CONTINUES TO DRIFT SOUTH WHILE GETTING PULLED INTO CIRCULATION AROUND CLOSED UPPER LOW OVER THE LOWER MISSISSIPPI VALLEY. VARIOUS HIGH-RES CONVECTIVE-ALLOWING GUIDANCE DEPICTS AFTERNOON CONVECTION DEVELOPING GENERALLY ALONG/SOUTH OF OUR SOUTHERN CWA BORDER...THUS HAVE MAINTAINED SOME SLIGHT CHANCE POPS SOUTH OF ABOUT A FAIRBURY TO WATSEKA TO FOWLER LINE. FARTHER NORTH...NORTHEAST LOW LEVEL WINDS CONTINUE TO BRING DRIER AND MORE STABLE AIR INTO THE AREA FROM ACROSS THE LAKES. PATCHY LOW CLOUD COVER OVER PARTS OF THE AREA SHOULD CLEAR OUT LATER THIS MORNING...WITH MODEL FORECAST SOUNDINGS INDICATING WARMING AND DRYING FROM ABOVE AS SUBSIDENCE DEVELOPS WITH UPPER RIDGE BUILDING INTO THE UPPER MIDWEST. THIS UPPER RIDGE CONTINUES TO BUILD AND SLOWLY DRIFT SOUTHEAST ACROSS THE REGION INTO SATURDAY...PRODUCING DRY CONDITIONS WITH A STEADY MODERATION IN TEMPERATURES. SURFACE HIGH PRESSURE WILL REMAIN TO OUR NORTHEAST AND EAST DURING THE PERIOD...GRADUALLY WEAKENING AND PULLING OFF TO THE EAST AND ALLOWING NORTHEAST SURFACE WINDS TO GRADUALLY VEER SOUTHEAST AND DECREASING THE AMOUNT OF LAKE COOLING. WITH A GOOD AMOUNT OF SUNSHINE EXPECTED TODAY...FRIDAY AND SATURDAY...HAVE GENERALLY UTILIZED WARMER GUIDANCE FOR HIGH TEMPS...WITH UPPER 70S AND LOWER 80S EXPECTED TODAY WELL AWAY FROM THE LAKE WARMING TO THE LOW-MID 80S BY SATURDAY. AS FETCH ACROSS THE LAKE DECREASES WITH VEERING LOW LEVEL WINDS...SHORE AREAS SHOULD ALSO MODERATE FROM THE LOW-MID 60S TODAY TO THE LOW-MID 70S BY SATURDAY. DRY AIR WILL SUPPORT COOL OVERNIGHT TEMPS PARTICULARLY ACROSS NORTHEAST IL...WITH A FEW UPPER 40S POSSIBLE TONIGHT NEAR THE LAKE. ON SATURDAY...THE UPPER RIDGE AXIS WILL SHIFT SOUTHEAST OF THE AREA AS A STRONG UPPER JET MAX SPREADS ACROSS ONTARIO AND THE FAR UPPER MIDWEST. MEDIUM RANGE MODEL SOLUTIONS ARE IN GOOD AGREEMENT IN DEPICTING A SHORT WAVE LIFTING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY SATURDAY AFTERNOON/NIGHT...HELPING INDUCE SURFACE PRESSURE FALLS ACROSS THE UPPER MISSISSIPPI VALLEY AND VEERING LOW LEVEL WINDS MORE SOUTHERLY. WARM/MOIST ADVECTION IN RETURN FLOW WILL BRING WARM AND HUMID CONDITIONS BACK TO THE FORECAST AREA BY SUNDAY...WITH THE POTENTIAL FOR A FEW ELEVATED THUNDERSTORMS ACROSS NORTHWEST IL TOWARD SUNDAY MORNING ALONG EASTERN PERIPHERY OF BROAD SOUTHWESTERLY LOW LEVEL JET AND THE SUBTLE WARM FRONT. POTENTIAL FOR THUNDERSTORMS INCREASES AS AREA BECOMES FIRMLY ENTRENCHED IN THE WARM SECTOR SUNDAY AND SUNDAY NIGHT...WITH TEMPS MID-UPPER 80S AND DEW POINT TEMPS 65-70 PROGGED. GUIDANCE DIFFERS WITH DETAILS OF SHORT WAVES MOVING THROUGH SOUTHWEST FLOW ALOFT INTO EARLY NEXT WEEK...THOUGH THE POTENTIAL EXISTS FOR SEVERAL ROUNDS OF THUNDERSTORMS TO AFFECT THE REGION INTO AT LEAST TUESDAY AS COLD FRONT SLOWLY MOVES SOUTH INTO A VERY WARM AND MOIST AIR MASS. WEST-SOUTHWEST TO EAST-NORTHEAST ORIENTATION OF BOUNDARY COMBINED WITH HIGH PRECIPITABLE WATER VALUES (1.5-2.0 INCHES PER GFS SOUNDINGS) WILL LIKELY SUPPORT A HEAVY RAINFALL THREAT...AND INCREASING DEEP LAYER BULK SHEAR ESPECIALLY MON-WED ALSO SUGGESTS SEVERE MCS POTENTIAL. FOR NOW HAVE MAINTAINED RATHER BROAD-BRUSHED CHANCE POPS FROM SUNDAY ONWARD...THOUGH DETAILS SUCH AS THE LOCATION OF THE FRONTAL BOUNDARY (LIKELY MODULATED BY CONVECTIVE OUTFLOWS)...AS WELL AS INDIVIDUAL LOW-AMPLITUDE WAVES WILL ULTIMATELY DRIVE CONVECTIVE TRENDS AND TIMING DURING THIS PERIOD. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * NELY-ELY WINDS ARND 10KT OR SLIGHTLY HIGHER THROUGH SUNSET. KREIN //DISCUSSION...UPDATED 18Z... THE LOW STRATUS BURNED OFF BY LATE MORNING AND VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR THE REMAINDER OF THE DAY AND INTO TONIGHT. THE MAIN FORECAST CONCERN WILL BE WIND DIRECTION. WITH HIGH PRESSURE OVER THE UPPER GREAT LAKES AND COMPLEX TROUGHING OVER THE CENTRAL PLAINS...WINDS WILL BE ELY OR ENEY THROUGH THE PERIOD WITH SPEEDS NEAR OR SLIGHTLY GREATER THAN 10KT. WITH WEAK WINDS ALOFT...DO NOT EXPECT MUCH IN THE WAY OF GUSTINESS...THOUGH AN OCCASIONAL GUST TO 15KT IS POSSIBLE. UNDER CLEAR SKIES...EXPECT THE LOW LEVELS TO DECOUPLE AT SUNSET AND WINDS SHOULD DROP OFF TO AROUND 5KT OR LESS. WITH HIGH PRESSURE CONTINUING TO BUILD SOUTH ACROSS THE WESTERN GREAT LAKES REGION AND INTO THE MIDDLE MISSISSIPPI VALLEY...EXPECT GENERALLY LIGHT WINDS AND MOSTLY CLEAR SKIES TO PREVAIL THROUGH THE PERIOD. THERE IS SOME CONCERN FOR SOME ISOLD BR DEVELOPMENT DURG THE PRE-DAWN HOURS...BUT ANY VIS RESTRICTIONS WOULD LIKELY BE AT RFD/DPA RATHER THAN THE MORE URBAN SITES. KREIN //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN ALL FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT THROUGH SATURDAY...VFR. SUNDAY THROUGH WEDNESDAY...PERIODIC CHANCES FOR THUNDERSTORMS. PRIMARILY VFR. BMD && .MARINE... 246 AM CDT HIGH PRESSURE EXTENDS FROM HUDSON BAY INTO THE CENTRAL GREAT LAKES REGION WHERE IT WILL SLOWLY MIGRATE TO THE EASTERN LAKES BY SATURDAY. IN THE MEANTIME...MODEST NORTHEAST TO EAST WINDS WILL PREVAIL ACROSS LAKE MICHIGAN. WINDS ARE EXPECTED TO BE STRONGEST ON THE SOUTH END OF THE LAKE WHERE IT MAY PEAK AROUND 15 TO 20 KT THIS AFTERNOON. A WARM FRONT WILL LIFT ACROSS LAKE MICHIGAN THIS WEEKEND WITH WINDS VEERING AROUND TO THE SOUTH BY SUNDAY. SOUTH TO SOUTHWEST WINDS ARE THEN EXPECTED TO PERSIST THROUGH AROUND MIDWEEK WITH ANOTHER COLD FRONT DROPS ACROSS THE LAKE. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1215 PM CDT Thu May 29 2014 .DISCUSSION... ISSUED 1036 AM CDT Thu May 29 2014 Back-door cool front has slipped south to just north of the I-70 corridor. True push of cool/dry air lags well north of the front, though northeast flow north of the boundary has brought slightly cooler and less humid air into the far northern CWA with dewpoints in the low 60s, while upper 60s dewpoints remain over the central and south. Aloft, water vapor imagery indicates a cutoff low spinning through the lower MS valley with the northern fringes of this feature bringing clouds into the southern CWA and lift producing showers in far southern IL/IN. A separate weak shortwave was noted in NW IL and is forecast to get absorbed into the circulation of the upper low as is shifts SE today. 12Z ILX sounding shows little airmass change from yesterday even as the front has shifted south. Given afternoon CAPEs near 2000 J/kg and light wind fields aloft, expect isolated to scattered thunderstorm development as convective temperatures are reached. Hi-res models show this possible for much of the CWA except the far north where somewhat drier air should keep areas north of Peoria and Galesburg dry. For the bulk of the CWA, slow moving iso/sct storms will produce brief heavy rain rates. Given high instability and weak shear with a boundary in the area, isolated land spouts will again be a concern. Non-supercell tor parameters off RAP and NAM suggest the central/southern CWA will again be at risk during early to mid afternoon, especially near the main synoptic boundary or mesoscale boundary interactions. Raised max temps a degree or two with highs in the lower 80s. && .AVIATION... ISSUED 1215 PM CDT Thu May 29 2014 A weak cool front has slipped south of the I-72 terminals this morning. Calm winds in the vicinity of the boundary become ENE at 5-10 kts north of the boundary. This general wind flow is expected through this TAF cycle as the front slowly shifts farther south, and high pressure remains perched over the Great Lakes. Isolated to scattered instability showers/storms have already developed and will continue through late afternoon, despite the front being to our south. Due to low coverage, have VCTS in TAFs and will amend for tempo groups if conditions warrant. Brief reductions to IFR cigs/vsbys possible in +TSRA. Diurnal decrease in activity this evening with VFR conditions predominant through Thu morning. Exception would be within a few hours of sunrise, with patchy MVFR fog possible due to light winds and high RH. 25 && .PREV DISCUSSION... ISSUED 250 AM CDT Thu May 29 2014 Weak frontal boundary centered just north of the I-70 corridor early this morning. High pressure over the Great Lakes is providing a northeast flow behind the front, which has dropped dew points into the 50s from Galesburg to Bloomington northward, while mid to upper 60s still prevail elsewhere. Still a fair amount of cloud cover over the forecast area, some streaming north from the ever-present upper low, now centered in south central Arkansas. There were a few showers recently near the boundary which drifted northwest due to that low, although these have now faded out. Rain chances continue to be the primary forecast concern, with next week`s chances a bit more challenging due to more model disagreement. SHORT TERM...Today through Saturday: The frontal boundary should be quasi-stationary between the I-72 and I-70 corridors today, and will be the focus for the next round of scattered showers and storms beginning around noon. Have had some heavier pockets of rain recently, and with precipitable water values around 1.5 to 1.6 inches, today shouldn`t be any different. Severe weather threat remains minimal due to low shear values, but cannot rule out some isolated funnels or land spouts similar to yesterday, with the boundary overhead. Non-supercell tornado parameter from the RAP model focuses on a couple areas, one along the I-74 corridor just north of the main precipitation area, and the other along I-72 near the boundary. Any such activity would be most likely between noon and 4 pm. The boundary will be pushed southward again tonight as an upper high slides moves into the upper Mississippi Valley. As it will not make it terribly far, the convection on Friday and Saturday will be close by, but mostly out of our forecast area. Have maintained some 20% PoP`s along the southern CWA border Friday afternoon, but kept Saturday dry for now. LONG TERM...Sunday through Wednesday: Upper ridging breaks down during the weekend with more of a southwest flow across the nation early next week, and the northern jet stream along the Canadian border. Right now the ECMWF is the odd model out in developing an upper low over the upper Mississippi Valley which slowly drifts eastward through the Great Lakes during the week, while the GFS, GEM and GFS ensembles have more of periodic shortwave interaction between the two upper flows. Sunday into early Monday are in most agreement with rain chances, but trends widen after that. The ECMWF and the GEM to an extent have the surface cyclone somewhat in agreement into Tuesday with the cold front coming through, which would support the rain chances continuing. Toward mid week, there is much more uncertainty as the GFS never actually brings the front through and holds it up near I-80, thus lingering rain chances, while the ECMWF is dry. Have kept some PoP`s in for Wednesday for now, but scaled them back from the initial blended guidance. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1103 AM CDT THU MAY 29 2014 .DISCUSSION... 346 AM CDT FORECAST CONCERNS THIS MORNING FOCUS ON DRIER NORTHEAST LOW LEVEL WINDS TODAY...WITH DECREASING CLOUDINESS AND THREAT OF AFTERNOON THUNDERSTORMS SHIFTING DOWNSTATE ALONG/SOUTH OF WFO LOT/ILX BORDER. DRY AND MILD CONDITIONS ANTICIPATED OVER THE NEXT FEW DAYS WITH A WARMING TREND INTO THE WEEKEND...AND A GRADUAL DECREASE IN LAKE COOLING. A PERIOD OF ACTIVE WEATHER WITH HEAVY RAINFALL AND INCREASING SEVERE THUNDERSTORM POTENTIAL APPEARS TO BE SHAPING UP FOR DAYS 4-7 (SUNDAY-NEXT WEDNESDAY)...AS A COLD FRONT SAGS INTO WARM/HUMID AIR MASS WHICH TAKES UP RESIDENCE ACROSS THE AREA. WEAK SURFACE LOW PRESSURE CONTINUES TO SETTLE SOUTHWARD ACROSS EASTERN MISSOURI THIS MORNING...WITH A NEARLY STATIONARY COLD FRONT STRETCHING WEST-EAST ACROSS SOUTH CENTRAL IL/IN. THIS BOUNDARY WILL CONTINUE TO BE THE FOCUS FOR DIURNAL SHOWER/THUNDERSTORM DEVELOPMENT THIS AFTERNOON...AS WEAKENING SHEARED MID-LEVEL VORT MAXIMA CONTINUES TO DRIFT SOUTH WHILE GETTING PULLED INTO CIRCULATION AROUND CLOSED UPPER LOW OVER THE LOWER MISSISSIPPI VALLEY. VARIOUS HIGH-RES CONVECTIVE-ALLOWING GUIDANCE DEPICTS AFTERNOON CONVECTION DEVELOPING GENERALLY ALONG/SOUTH OF OUR SOUTHERN CWA BORDER...THUS HAVE MAINTAINED SOME SLIGHT CHANCE POPS SOUTH OF ABOUT A FAIRBURY TO WATSEKA TO FOWLER LINE. FARTHER NORTH...NORTHEAST LOW LEVEL WINDS CONTINUE TO BRING DRIER AND MORE STABLE AIR INTO THE AREA FROM ACROSS THE LAKES. PATCHY LOW CLOUD COVER OVER PARTS OF THE AREA SHOULD CLEAR OUT LATER THIS MORNING...WITH MODEL FORECAST SOUNDINGS INDICATING WARMING AND DRYING FROM ABOVE AS SUBSIDENCE DEVELOPS WITH UPPER RIDGE BUILDING INTO THE UPPER MIDWEST. THIS UPPER RIDGE CONTINUES TO BUILD AND SLOWLY DRIFT SOUTHEAST ACROSS THE REGION INTO SATURDAY...PRODUCING DRY CONDITIONS WITH A STEADY MODERATION IN TEMPERATURES. SURFACE HIGH PRESSURE WILL REMAIN TO OUR NORTHEAST AND EAST DURING THE PERIOD...GRADUALLY WEAKENING AND PULLING OFF TO THE EAST AND ALLOWING NORTHEAST SURFACE WINDS TO GRADUALLY VEER SOUTHEAST AND DECREASING THE AMOUNT OF LAKE COOLING. WITH A GOOD AMOUNT OF SUNSHINE EXPECTED TODAY...FRIDAY AND SATURDAY...HAVE GENERALLY UTILIZED WARMER GUIDANCE FOR HIGH TEMPS...WITH UPPER 70S AND LOWER 80S EXPECTED TODAY WELL AWAY FROM THE LAKE WARMING TO THE LOW-MID 80S BY SATURDAY. AS FETCH ACROSS THE LAKE DECREASES WITH VEERING LOW LEVEL WINDS...SHORE AREAS SHOULD ALSO MODERATE FROM THE LOW-MID 60S TODAY TO THE LOW-MID 70S BY SATURDAY. DRY AIR WILL SUPPORT COOL OVERNIGHT TEMPS PARTICULARLY ACROSS NORTHEAST IL...WITH A FEW UPPER 40S POSSIBLE TONIGHT NEAR THE LAKE. ON SATURDAY...THE UPPER RIDGE AXIS WILL SHIFT SOUTHEAST OF THE AREA AS A STRONG UPPER JET MAX SPREADS ACROSS ONTARIO AND THE FAR UPPER MIDWEST. MEDIUM RANGE MODEL SOLUTIONS ARE IN GOOD AGREEMENT IN DEPICTING A SHORT WAVE LIFTING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY SATURDAY AFTERNOON/NIGHT...HELPING INDUCE SURFACE PRESSURE FALLS ACROSS THE UPPER MISSISSIPPI VALLEY AND VEERING LOW LEVEL WINDS MORE SOUTHERLY. WARM/MOIST ADVECTION IN RETURN FLOW WILL BRING WARM AND HUMID CONDITIONS BACK TO THE FORECAST AREA BY SUNDAY...WITH THE POTENTIAL FOR A FEW ELEVATED THUNDERSTORMS ACROSS NORTHWEST IL TOWARD SUNDAY MORNING ALONG EASTERN PERIPHERY OF BROAD SOUTHWESTERLY LOW LEVEL JET AND THE SUBTLE WARM FRONT. POTENTIAL FOR THUNDERSTORMS INCREASES AS AREA BECOMES FIRMLY ENTRENCHED IN THE WARM SECTOR SUNDAY AND SUNDAY NIGHT...WITH TEMPS MID-UPPER 80S AND DEW POINT TEMPS 65-70 PROGGED. GUIDANCE DIFFERS WITH DETAILS OF SHORT WAVES MOVING THROUGH SOUTHWEST FLOW ALOFT INTO EARLY NEXT WEEK...THOUGH THE POTENTIAL EXISTS FOR SEVERAL ROUNDS OF THUNDERSTORMS TO AFFECT THE REGION INTO AT LEAST TUESDAY AS COLD FRONT SLOWLY MOVES SOUTH INTO A VERY WARM AND MOIST AIR MASS. WEST-SOUTHWEST TO EAST-NORTHEAST ORIENTATION OF BOUNDARY COMBINED WITH HIGH PRECIPITABLE WATER VALUES (1.5-2.0 INCHES PER GFS SOUNDINGS) WILL LIKELY SUPPORT A HEAVY RAINFALL THREAT...AND INCREASING DEEP LAYER BULK SHEAR ESPECIALLY MON-WED ALSO SUGGESTS SEVERE MCS POTENTIAL. FOR NOW HAVE MAINTAINED RATHER BROAD-BRUSHED CHANCE POPS FROM SUNDAY ONWARD...THOUGH DETAILS SUCH AS THE LOCATION OF THE FRONTAL BOUNDARY (LIKELY MODULATED BY CONVECTIVE OUTFLOWS)...AS WELL AS INDIVIDUAL LOW-AMPLITUDE WAVES WILL ULTIMATELY DRIVE CONVECTIVE TRENDS AND TIMING DURING THIS PERIOD. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * NELY-ELY WINDS ARND 10KT OR SLIGHTLY HIGHER THROUGH EARLY EVENING. KREIN //DISCUSSION...UPDATED 12Z... IFR/MVFR STRATUS HAS OVERSPREAD THE TERMINALS THIS MORNING AND IS EXPECTED TO PERSIST FOR A FEW HOURS BEFORE SCATTERING OUT MID TO LATE THIS MORNING AND RETURNING TO VFR. HIGH PRESSURE OVER THE GREAT LAKES WILL THEN PROVIDE FAIR WEATHER WITH MODEST NORTHEAST WIND THROUGH THE REMAINDER OF THE DAY. WINDS WILL GRADUALLY PICK UP THROUGH THE MORNING...TOPPING OUT A LITTLE OVER 10 KTS BY LATE MORNING THROUGH THE AFTERNOON HOURS AND EARLY EVENING HOURS. ANOTHER VFR DAY IS ON TAP TOMORROW WITH WINDS OUT OF THE EAST. BMD //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN ALL FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT THROUGH SATURDAY...VFR. SUNDAY THROUGH WEDNESDAY...PERIODIC CHANCES FOR THUNDERSTORMS. PRIMARILY VFR. BMD && .MARINE... 246 AM CDT HIGH PRESSURE EXTENDS FROM HUDSON BAY INTO THE CENTRAL GREAT LAKES REGION WHERE IT WILL SLOWLY MIGRATE TO THE EASTERN LAKES BY SATURDAY. IN THE MEANTIME...MODEST NORTHEAST TO EAST WINDS WILL PREVAIL ACROSS LAKE MICHIGAN. WINDS ARE EXPECTED TO BE STRONGEST ON THE SOUTH END OF THE LAKE WHERE IT MAY PEAK AROUND 15 TO 20 KT THIS AFTERNOON. A WARM FRONT WILL LIFT ACROSS LAKE MICHIGAN THIS WEEKEND WITH WINDS VEERING AROUND TO THE SOUTH BY SUNDAY. SOUTH TO SOUTHWEST WINDS ARE THEN EXPECTED TO PERSIST THROUGH AROUND MIDWEEK WITH ANOTHER COLD FRONT DROPS ACROSS THE LAKE. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1036 AM CDT Thu May 29 2014 .DISCUSSION... ISSUED 1036 AM CDT Thu May 29 2014 Back-door cool front has slipped south to just north of the I-70 corridor. True push of cool/dry air lags well north of the front, though northeast flow north of the boundary has brought slightly cooler and less humid air into the far northern CWA with dewpoints in the low 60s, while upper 60s dewpoints remain over the central and south. Aloft, water vapor imagery indicates a cutoff low spinning through the lower MS valley with the northern fringes of this feature bringing clouds into the southern CWA and lift producing showers in far southern IL/IN. A separate weak shortwave was noted in NW IL and is forecast to get absorbed into the circulation of the upper low as is shifts SE today. 12Z ILX sounding shows little airmass change from yesterday even as the front has shifted south. Given afternoon CAPEs near 2000 J/kg and light wind fields aloft, expect isolated to scattered thunderstorm development as convective temperatures are reached. Hi-res models show this possible for much of the CWA except the far north where somewhat drier air should keep areas north of Peoria and Galesburg dry. For the bulk of the CWA, slow moving iso/sct storms will produce brief heavy rain rates. Given high instability and weak shear with a boundary in the area, isolated land spouts will again be a concern. Non-supercell tor parameters off RAP and NAM suggest the central/southern CWA will again be at risk during early to mid afternoon, especially near the main synoptic boundary or mesoscale boundary interactions. Raised max temps a degree or two with highs in the lower 80s. 25 && .AVIATION... ISSUED 600 AM CDT Thu May 29 2014 Areas of MVFR cigs/vsbys possible thru 14z...then VFR conditions expected into this evening. The front that moved thru our area last evening has shifted well south of the TAF sites. As a result, winds have become east to northeast over the entire area and are expected to remain that way today. A band of MVFR cigs with some local IFR cigs noted on the latest satellite data just to our north and east, tracking west and northwest. The bulk of the lower cigs will remain just to our north over the next few hours but over the past few hours have noted an increase in stratus on the southwest flank of the cloud bank so may have to include a period of IFR cigs at KBMI in the 12z-15z time frame. Once we burn of the fog/hz and cig restrictions this morning, forecast soundings suggest a rapid increase in cumulus after 15z with scattered to broken cigs at or above 5000 feet by late morning into the afternoon hours. Will continue with VCTS at all TAF sites but it appears the better coverage of storms will be south of I74 this afternoon. Any convection that does develop this afternoon should dissipate by early this evening but with the residual low level moisture in place, we could see some MVFR vsbys develop again in fog aftr 08z. East to northeast winds will prevail today with speeds of 8 to 13 kts and the trend more from an east direction tonight at less than 10 kts. Smith && .PREV DISCUSSION... ISSUED 250 AM CDT Thu May 29 2014 Weak frontal boundary centered just north of the I-70 corridor early this morning. High pressure over the Great Lakes is providing a northeast flow behind the front, which has dropped dew points into the 50s from Galesburg to Bloomington northward, while mid to upper 60s still prevail elsewhere. Still a fair amount of cloud cover over the forecast area, some streaming north from the ever-present upper low, now centered in south central Arkansas. There were a few showers recently near the boundary which drifted northwest due to that low, although these have now faded out. Rain chances continue to be the primary forecast concern, with next week`s chances a bit more challenging due to more model disagreement. SHORT TERM...Today through Saturday: The frontal boundary should be quasi-stationary between the I-72 and I-70 corridors today, and will be the focus for the next round of scattered showers and storms beginning around noon. Have had some heavier pockets of rain recently, and with precipitable water values around 1.5 to 1.6 inches, today shouldn`t be any different. Severe weather threat remains minimal due to low shear values, but cannot rule out some isolated funnels or land spouts similar to yesterday, with the boundary overhead. Non-supercell tornado parameter from the RAP model focuses on a couple areas, one along the I-74 corridor just north of the main precipitation area, and the other along I-72 near the boundary. Any such activity would be most likely between noon and 4 pm. The boundary will be pushed southward again tonight as an upper high slides moves into the upper Mississippi Valley. As it will not make it terribly far, the convection on Friday and Saturday will be close by, but mostly out of our forecast area. Have maintained some 20% PoP`s along the southern CWA border Friday afternoon, but kept Saturday dry for now. LONG TERM...Sunday through Wednesday: Upper ridging breaks down during the weekend with more of a southwest flow across the nation early next week, and the northern jet stream along the Canadian border. Right now the ECMWF is the odd model out in developing an upper low over the upper Mississippi Valley which slowly drifts eastward through the Great Lakes during the week, while the GFS, GEM and GFS ensembles have more of periodic shortwave interaction between the two upper flows. Sunday into early Monday are in most agreement with rain chances, but trends widen after that. The ECMWF and the GEM to an extent have the surface cyclone somewhat in agreement into Tuesday with the cold front coming through, which would support the rain chances continuing. Toward mid week, there is much more uncertainty as the GFS never actually brings the front through and holds it up near I-80, thus lingering rain chances, while the ECMWF is dry. Have kept some PoP`s in for Wednesday for now, but scaled them back from the initial blended guidance. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
633 AM CDT THU MAY 29 2014 .DISCUSSION... 346 AM CDT FORECAST CONCERNS THIS MORNING FOCUS ON DRIER NORTHEAST LOW LEVEL WINDS TODAY...WITH DECREASING CLOUDINESS AND THREAT OF AFTERNOON THUNDERSTORMS SHIFTING DOWNSTATE ALONG/SOUTH OF WFO LOT/ILX BORDER. DRY AND MILD CONDITIONS ANTICIPATED OVER THE NEXT FEW DAYS WITH A WARMING TREND INTO THE WEEKEND...AND A GRADUAL DECREASE IN LAKE COOLING. A PERIOD OF ACTIVE WEATHER WITH HEAVY RAINFALL AND INCREASING SEVERE THUNDERSTORM POTENTIAL APPEARS TO BE SHAPING UP FOR DAYS 4-7 (SUNDAY-NEXT WEDNESDAY)...AS A COLD FRONT SAGS INTO WARM/HUMID AIR MASS WHICH TAKES UP RESIDENCE ACROSS THE AREA. WEAK SURFACE LOW PRESSURE CONTINUES TO SETTLE SOUTHWARD ACROSS EASTERN MISSOURI THIS MORNING...WITH A NEARLY STATIONARY COLD FRONT STRETCHING WEST-EAST ACROSS SOUTH CENTRAL IL/IN. THIS BOUNDARY WILL CONTINUE TO BE THE FOCUS FOR DIURNAL SHOWER/THUNDERSTORM DEVELOPMENT THIS AFTERNOON...AS WEAKENING SHEARED MID-LEVEL VORT MAXIMA CONTINUES TO DRIFT SOUTH WHILE GETTING PULLED INTO CIRCULATION AROUND CLOSED UPPER LOW OVER THE LOWER MISSISSIPPI VALLEY. VARIOUS HIGH-RES CONVECTIVE-ALLOWING GUIDANCE DEPICTS AFTERNOON CONVECTION DEVELOPING GENERALLY ALONG/SOUTH OF OUR SOUTHERN CWA BORDER...THUS HAVE MAINTAINED SOME SLIGHT CHANCE POPS SOUTH OF ABOUT A FAIRBURY TO WATSEKA TO FOWLER LINE. FARTHER NORTH...NORTHEAST LOW LEVEL WINDS CONTINUE TO BRING DRIER AND MORE STABLE AIR INTO THE AREA FROM ACROSS THE LAKES. PATCHY LOW CLOUD COVER OVER PARTS OF THE AREA SHOULD CLEAR OUT LATER THIS MORNING...WITH MODEL FORECAST SOUNDINGS INDICATING WARMING AND DRYING FROM ABOVE AS SUBSIDENCE DEVELOPS WITH UPPER RIDGE BUILDING INTO THE UPPER MIDWEST. THIS UPPER RIDGE CONTINUES TO BUILD AND SLOWLY DRIFT SOUTHEAST ACROSS THE REGION INTO SATURDAY...PRODUCING DRY CONDITIONS WITH A STEADY MODERATION IN TEMPERATURES. SURFACE HIGH PRESSURE WILL REMAIN TO OUR NORTHEAST AND EAST DURING THE PERIOD...GRADUALLY WEAKENING AND PULLING OFF TO THE EAST AND ALLOWING NORTHEAST SURFACE WINDS TO GRADUALLY VEER SOUTHEAST AND DECREASING THE AMOUNT OF LAKE COOLING. WITH A GOOD AMOUNT OF SUNSHINE EXPECTED TODAY...FRIDAY AND SATURDAY...HAVE GENERALLY UTILIZED WARMER GUIDANCE FOR HIGH TEMPS...WITH UPPER 70S AND LOWER 80S EXPECTED TODAY WELL AWAY FROM THE LAKE WARMING TO THE LOW-MID 80S BY SATURDAY. AS FETCH ACROSS THE LAKE DECREASES WITH VEERING LOW LEVEL WINDS...SHORE AREAS SHOULD ALSO MODERATE FROM THE LOW-MID 60S TODAY TO THE LOW-MID 70S BY SATURDAY. DRY AIR WILL SUPPORT COOL OVERNIGHT TEMPS PARTICULARLY ACROSS NORTHEAST IL...WITH A FEW UPPER 40S POSSIBLE TONIGHT NEAR THE LAKE. ON SATURDAY...THE UPPER RIDGE AXIS WILL SHIFT SOUTHEAST OF THE AREA AS A STRONG UPPER JET MAX SPREADS ACROSS ONTARIO AND THE FAR UPPER MIDWEST. MEDIUM RANGE MODEL SOLUTIONS ARE IN GOOD AGREEMENT IN DEPICTING A SHORT WAVE LIFTING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY SATURDAY AFTERNOON/NIGHT...HELPING INDUCE SURFACE PRESSURE FALLS ACROSS THE UPPER MISSISSIPPI VALLEY AND VEERING LOW LEVEL WINDS MORE SOUTHERLY. WARM/MOIST ADVECTION IN RETURN FLOW WILL BRING WARM AND HUMID CONDITIONS BACK TO THE FORECAST AREA BY SUNDAY...WITH THE POTENTIAL FOR A FEW ELEVATED THUNDERSTORMS ACROSS NORTHWEST IL TOWARD SUNDAY MORNING ALONG EASTERN PERIPHERY OF BROAD SOUTHWESTERLY LOW LEVEL JET AND THE SUBTLE WARM FRONT. POTENTIAL FOR THUNDERSTORMS INCREASES AS AREA BECOMES FIRMLY ENTRENCHED IN THE WARM SECTOR SUNDAY AND SUNDAY NIGHT...WITH TEMPS MID-UPPER 80S AND DEW POINT TEMPS 65-70 PROGGED. GUIDANCE DIFFERS WITH DETAILS OF SHORT WAVES MOVING THROUGH SOUTHWEST FLOW ALOFT INTO EARLY NEXT WEEK...THOUGH THE POTENTIAL EXISTS FOR SEVERAL ROUNDS OF THUNDERSTORMS TO AFFECT THE REGION INTO AT LEAST TUESDAY AS COLD FRONT SLOWLY MOVES SOUTH INTO A VERY WARM AND MOIST AIR MASS. WEST-SOUTHWEST TO EAST-NORTHEAST ORIENTATION OF BOUNDARY COMBINED WITH HIGH PRECIPITABLE WATER VALUES (1.5-2.0 INCHES PER GFS SOUNDINGS) WILL LIKELY SUPPORT A HEAVY RAINFALL THREAT...AND INCREASING DEEP LAYER BULK SHEAR ESPECIALLY MON-WED ALSO SUGGESTS SEVERE MCS POTENTIAL. FOR NOW HAVE MAINTAINED RATHER BROAD-BRUSHED CHANCE POPS FROM SUNDAY ONWARD...THOUGH DETAILS SUCH AS THE LOCATION OF THE FRONTAL BOUNDARY (LIKELY MODULATED BY CONVECTIVE OUTFLOWS)...AS WELL AS INDIVIDUAL LOW-AMPLITUDE WAVES WILL ULTIMATELY DRIVE CONVECTIVE TRENDS AND TIMING DURING THIS PERIOD. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * MVFR/IFR CIGS SCATTERING OUT MID TO LATE MORNING. BMD //DISCUSSION...UPDATED 12Z... IFR/MVFR STRATUS HAS OVERSPREAD THE TERMINALS THIS MORNING AND IS EXPECTED TO PERSIST FOR A FEW HOURS BEFORE SCATTERING OUT MID TO LATE THIS MORNING AND RETURNING TO VFR. HIGH PRESSURE OVER THE GREAT LAKES WILL THEN PROVIDE FAIR WEATHER WITH MODEST NORTHEAST WIND THROUGH THE REMAINDER OF THE DAY. WINDS WILL GRADUALLY PICK UP THROUGH THE MORNING...TOPPING OUT A LITTLE OVER 10 KTS BY LATE MORNING THROUGH THE AFTERNOON HOURS AND EARLY EVENING HOURS. ANOTHER VFR DAY IS ON TAP TOMORROW WITH WINDS OUT OF THE EAST. BMD //ORD AND MDW CONFIDENCE...UPDATED 12Z... * MEDIUM CONFIDENCE IN DURATION OF LOWER CIGS. * HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS.... BMD //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT THROUGH SATURDAY...VFR. SUNDAY THROUGH WEDNESDAY...PERIODIC CHANCES FOR THUNDERSTORMS. PRIMARILY VFR. BMD && .MARINE... 246 AM CDT HIGH PRESSURE EXTENDS FROM HUDSON BAY INTO THE CENTRAL GREAT LAKES REGION WHERE IT WILL SLOWLY MIGRATE TO THE EASTERN LAKES BY SATURDAY. IN THE MEANTIME...MODEST NORTHEAST TO EAST WINDS WILL PREVAIL ACROSS LAKE MICHIGAN. WINDS ARE EXPECTED TO BE STRONGEST ON THE SOUTH END OF THE LAKE WHERE IT MAY PEAK AROUND 15 TO 20 KT THIS AFTERNOON. A WARM FRONT WILL LIFT ACROSS LAKE MICHIGAN THIS WEEKEND WITH WINDS VEERING AROUND TO THE SOUTH BY SUNDAY. SOUTH TO SOUTHWEST WINDS ARE THEN EXPECTED TO PERSIST THROUGH AROUND MIDWEEK WITH ANOTHER COLD FRONT DROPS ACROSS THE LAKE. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 602 AM CDT Thu May 29 2014 .DISCUSSION... ISSUED 250 AM CDT Thu May 29 2014 Weak frontal boundary centered just north of the I-70 corridor early this morning. High pressure over the Great Lakes is providing a northeast flow behind the front, which has dropped dew points into the 50s from Galesburg to Bloomington northward, while mid to upper 60s still prevail elsewhere. Still a fair amount of cloud cover over the forecast area, some streaming north from the ever-present upper low, now centered in south central Arkansas. There were a few showers recently near the boundary which drifted northwest due to that low, although these have now faded out. Rain chances continue to be the primary forecast concern, with next week`s chances a bit more challenging due to more model disagreement. SHORT TERM...Today through Saturday: The frontal boundary should be quasi-stationary between the I-72 and I-70 corridors today, and will be the focus for the next round of scattered showers and storms beginning around noon. Have had some heavier pockets of rain recently, and with precipitable water values around 1.5 to 1.6 inches, today shouldn`t be any different. Severe weather threat remains minimal due to low shear values, but cannot rule out some isolated funnels or land spouts similar to yesterday, with the boundary overhead. Non-supercell tornado parameter from the RAP model focuses on a couple areas, one along the I-74 corridor just north of the main precipitation area, and the other along I-72 near the boundary. Any such activity would be most likely between noon and 4 pm. The boundary will be pushed southward again tonight as an upper high slides moves into the upper Mississippi Valley. As it will not make it terribly far, the convection on Friday and Saturday will be close by, but mostly out of our forecast area. Have maintained some 20% PoP`s along the southern CWA border Friday afternoon, but kept Saturday dry for now. LONG TERM...Sunday through Wednesday: Upper ridging breaks down during the weekend with more of a southwest flow across the nation early next week, and the northern jet stream along the Canadian border. Right now the ECMWF is the odd model out in developing an upper low over the upper Mississippi Valley which slowly drifts eastward through the Great Lakes during the week, while the GFS, GEM and GFS ensembles have more of periodic shortwave interaction between the two upper flows. Sunday into early Monday are in most agreement with rain chances, but trends widen after that. The ECMWF and the GEM to an extent have the surface cyclone somewhat in agreement into Tuesday with the cold front coming through, which would support the rain chances continuing. Toward mid week, there is much more uncertainty as the GFS never actually brings the front through and holds it up near I-80, thus lingering rain chances, while the ECMWF is dry. Have kept some PoP`s in for Wednesday for now, but scaled them back from the initial blended guidance. Geelhart && .AVIATION... ISSUED 600 AM CDT Thu May 29 2014 Areas of MVFR cigs/vsbys possible thru 14z...then VFR conditions expected into this evening. The front that moved thru our area last evening has shifted well south of the TAF sites. As a result, winds have become east to northeast over the entire area and are expected to remain that way today. A band of MVFR cigs with some local IFR cigs noted on the latest satellite data just to our north and east, tracking west and northwest. The bulk of the lower cigs will remain just to our north over the next few hours but over the past few hours have noted an increase in stratus on the southwest flank of the cloud bank so may have to include a period of IFR cigs at KBMI in the 12z-15z time frame. Once we burn of the fog/hz and cig restrictions this morning, forecast soundings suggest a rapid increase in cumulus after 15z with scattered to broken cigs at or above 5000 feet by late morning into the afternoon hours. Will continue with VCTS at all TAF sites but it appears the better coverage of storms will be south of I74 this afternoon. Any convection that does develop this afternoon should dissipate by early this evening but with the residual low level moisture in place, we could see some MVFR vsbys develop again in fog aftr 08z. East to northeast winds will prevail today with speeds of 8 to 13 kts and the trend more from an east direction tonight at less than 10 kts. Smith && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
347 AM CDT THU MAY 29 2014 .DISCUSSION... 346 AM CDT FORECAST CONCERNS THIS MORNING FOCUS ON DRIER NORTHEAST LOW LEVEL WINDS TODAY...WITH DECREASING CLOUDINESS AND THREAT OF AFTERNOON THUNDERSTORMS SHIFTING DOWNSTATE ALONG/SOUTH OF WFO LOT/ILX BORDER. DRY AND MILD CONDITIONS ANTICIPATED OVER THE NEXT FEW DAYS WITH A WARMING TREND INTO THE WEEKEND...AND A GRADUAL DECREASE IN LAKE COOLING. A PERIOD OF ACTIVE WEATHER WITH HEAVY RAINFALL AND INCREASING SEVERE THUNDERSTORM POTENTIAL APPEARS TO BE SHAPING UP FOR DAYS 4-7 (SUNDAY-NEXT WEDNESDAY)...AS A COLD FRONT SAGS INTO WARM/HUMID AIR MASS WHICH TAKES UP RESIDENCE ACROSS THE AREA. WEAK SURFACE LOW PRESSURE CONTINUES TO SETTLE SOUTHWARD ACROSS EASTERN MISSOURI THIS MORNING...WITH A NEARLY STATIONARY COLD FRONT STRETCHING WEST-EAST ACROSS SOUTH CENTRAL IL/IN. THIS BOUNDARY WILL CONTINUE TO BE THE FOCUS FOR DIURNAL SHOWER/THUNDERSTORM DEVELOPMENT THIS AFTERNOON...AS WEAKENING SHEARED MID-LEVEL VORT MAXIMA CONTINUES TO DRIFT SOUTH WHILE GETTING PULLED INTO CIRCULATION AROUND CLOSED UPPER LOW OVER THE LOWER MISSISSIPPI VALLEY. VARIOUS HIGH-RES CONVECTIVE-ALLOWING GUIDANCE DEPICTS AFTERNOON CONVECTION DEVELOPING GENERALLY ALONG/SOUTH OF OUR SOUTHERN CWA BORDER...THUS HAVE MAINTAINED SOME SLIGHT CHANCE POPS SOUTH OF ABOUT A FAIRBURY TO WATSEKA TO FOWLER LINE. FARTHER NORTH...NORTHEAST LOW LEVEL WINDS CONTINUE TO BRING DRIER AND MORE STABLE AIR INTO THE AREA FROM ACROSS THE LAKES. PATCHY LOW CLOUD COVER OVER PARTS OF THE AREA SHOULD CLEAR OUT LATER THIS MORNING...WITH MODEL FORECAST SOUNDINGS INDICATING WARMING AND DRYING FROM ABOVE AS SUBSIDENCE DEVELOPS WITH UPPER RIDGE BUILDING INTO THE UPPER MIDWEST. THIS UPPER RIDGE CONTINUES TO BUILD AND SLOWLY DRIFT SOUTHEAST ACROSS THE REGION INTO SATURDAY...PRODUCING DRY CONDITIONS WITH A STEADY MODERATION IN TEMPERATURES. SURFACE HIGH PRESSURE WILL REMAIN TO OUR NORTHEAST AND EAST DURING THE PERIOD...GRADUALLY WEAKENING AND PULLING OFF TO THE EAST AND ALLOWING NORTHEAST SURFACE WINDS TO GRADUALLY VEER SOUTHEAST AND DECREASING THE AMOUNT OF LAKE COOLING. WITH A GOOD AMOUNT OF SUNSHINE EXPECTED TODAY...FRIDAY AND SATURDAY...HAVE GENERALLY UTILIZED WARMER GUIDANCE FOR HIGH TEMPS...WITH UPPER 70S AND LOWER 80S EXPECTED TODAY WELL AWAY FROM THE LAKE WARMING TO THE LOW-MID 80S BY SATURDAY. AS FETCH ACROSS THE LAKE DECREASES WITH VEERING LOW LEVEL WINDS...SHORE AREAS SHOULD ALSO MODERATE FROM THE LOW-MID 60S TODAY TO THE LOW-MID 70S BY SATURDAY. DRY AIR WILL SUPPORT COOL OVERNIGHT TEMPS PARTICULARLY ACROSS NORTHEAST IL...WITH A FEW UPPER 40S POSSIBLE TONIGHT NEAR THE LAKE. ON SATURDAY...THE UPPER RIDGE AXIS WILL SHIFT SOUTHEAST OF THE AREA AS A STRONG UPPER JET MAX SPREADS ACROSS ONTARIO AND THE FAR UPPER MIDWEST. MEDIUM RANGE MODEL SOLUTIONS ARE IN GOOD AGREEMENT IN DEPICTING A SHORT WAVE LIFTING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY SATURDAY AFTERNOON/NIGHT...HELPING INDUCE SURFACE PRESSURE FALLS ACROSS THE UPPER MISSISSIPPI VALLEY AND VEERING LOW LEVEL WINDS MORE SOUTHERLY. WARM/MOIST ADVECTION IN RETURN FLOW WILL BRING WARM AND HUMID CONDITIONS BACK TO THE FORECAST AREA BY SUNDAY...WITH THE POTENTIAL FOR A FEW ELEVATED THUNDERSTORMS ACROSS NORTHWEST IL TOWARD SUNDAY MORNING ALONG EASTERN PERIPHERY OF BROAD SOUTHWESTERLY LOW LEVEL JET AND THE SUBTLE WARM FRONT. POTENTIAL FOR THUNDERSTORMS INCREASES AS AREA BECOMES FIRMLY ENTRENCHED IN THE WARM SECTOR SUNDAY AND SUNDAY NIGHT...WITH TEMPS MID-UPPER 80S AND DEW POINT TEMPS 65-70 PROGGED. GUIDANCE DIFFERS WITH DETAILS OF SHORT WAVES MOVING THROUGH SOUTHWEST FLOW ALOFT INTO EARLY NEXT WEEK...THOUGH THE POTENTIAL EXISTS FOR SEVERAL ROUNDS OF THUNDERSTORMS TO AFFECT THE REGION INTO AT LEAST TUESDAY AS COLD FRONT SLOWLY MOVES SOUTH INTO A VERY WARM AND MOIST AIR MASS. WEST-SOUTHWEST TO EAST-NORTHEAST ORIENTATION OF BOUNDARY COMBINED WITH HIGH PRECIPITABLE WATER VALUES (1.5-2.0 INCHES PER GFS SOUNDINGS) WILL LIKELY SUPPORT A HEAVY RAINFALL THREAT...AND INCREASING DEEP LAYER BULK SHEAR ESPECIALLY MON-WED ALSO SUGGESTS SEVERE MCS POTENTIAL. FOR NOW HAVE MAINTAINED RATHER BROAD-BRUSHED CHANCE POPS FROM SUNDAY ONWARD...THOUGH DETAILS SUCH AS THE LOCATION OF THE FRONTAL BOUNDARY (LIKELY MODULATED BY CONVECTIVE OUTFLOWS)...AS WELL AS INDIVIDUAL LOW-AMPLITUDE WAVES WILL ULTIMATELY DRIVE CONVECTIVE TRENDS AND TIMING DURING THIS PERIOD. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MVFR CIGS OVERSPREADING TERMINALS OVERNIGHT. BMD //DISCUSSION...UPDATED 06Z... HIGH PRESSURE IS SETTLING OVER THE NORTHERN GREAT LAKES REGION WHERE IT WILL REMAIN THROUGH THE TAF PERIOD PROVIDING LIGHT NORTHEASTERLY WINDS. WINDS WILL LIKELY PICK UP SOME DURING THE DAY THURSDAY AND MAY PUSH A LITTLE ABOVE 10 KT FOR A WHILE WITH AN EXTRA PUSH FROM THE LAKE. THE ONLY MINOR CONCERN THIS FORECAST PERIOD IS THE PRESENCE OF MVFR CIGS IN THE AREA WHICH ARE PROGGED TO SPREAD WEST OVER THE TERMINALS TONIGHT. GUIDANCE MAY BE OVERDOING THE LOW LEVEL MOISTURE SOME BUT THERE IS A BROAD AREA OF STRATUS/FOG OVER LAKE MICHIGAN AS WELL AS PATCHY MVFR STRATUS OVER N IN/SW MI THAT COULD POTENTIALLY SPREAD OVER THE TERMINALS TONIGHT. BMD //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW CONFIDENCE IN MVFR CIGS/TIMING. BMD //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... FRIDAY AND SATURDAY...VFR. SUNDAY THROUGH TUESDAY...MAINLY VFR WITH PERIODIC CHANCES FOR THUNDERSTORMS. MDB && .MARINE... 246 AM CDT HIGH PRESSURE EXTENDS FROM HUDSON BAY INTO THE CENTRAL GREAT LAKES REGION WHERE IT WILL SLOWLY MIGRATE TO THE EASTERN LAKES BY SATURDAY. IN THE MEANTIME...MODEST NORTHEAST TO EAST WINDS WILL PREVAIL ACROSS LAKE MICHIGAN. WINDS ARE EXPECTED TO BE STRONGEST ON THE SOUTH END OF THE LAKE WHERE IT MAY PEAK AROUND 15 TO 20 KT THIS AFTERNOON. A WARM FRONT WILL LIFT ACROSS LAKE MICHIGAN THIS WEEKEND WITH WINDS VEERING AROUND TO THE SOUTH BY SUNDAY. SOUTH TO SOUTHWEST WINDS ARE THEN EXPECTED TO PERSIST THROUGH AROUND MIDWEEK WITH ANOTHER COLD FRONT DROPS ACROSS THE LAKE. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 252 AM CDT Thu May 29 2014 .DISCUSSION... ISSUED 250 AM CDT Thu May 29 2014 Weak frontal boundary centered just north of the I-70 corridor early this morning. High pressure over the Great Lakes is providing a northeast flow behind the front, which has dropped dew points into the 50s from Galesburg to Bloomington northward, while mid to upper 60s still prevail elsewhere. Still a fair amount of cloud cover over the forecast area, some streaming north from the ever-present upper low, now centered in south central Arkansas. There were a few showers recently near the boundary which drifted northwest due to that low, although these have now faded out. Rain chances continue to be the primary forecast concern, with next week`s chances a bit more challenging due to more model disagreement. SHORT TERM...Today through Saturday: The frontal boundary should be quasi-stationary between the I-72 and I-70 corridors today, and will be the focus for the next round of scattered showers and storms beginning around noon. Have had some heavier pockets of rain recently, and with precipitable water values around 1.5 to 1.6 inches, today shouldn`t be any different. Severe weather threat remains minimal due to low shear values, but cannot rule out some isolated funnels or land spouts similar to yesterday, with the boundary overhead. Non-supercell tornado parameter from the RAP model focuses on a couple areas, one along the I-74 corridor just north of the main precipitation area, and the other along I-72 near the boundary. Any such activity would be most likely between noon and 4 pm. The boundary will be pushed southward again tonight as an upper high slides moves into the upper Mississippi Valley. As it will not make it terribly far, the convection on Friday and Saturday will be close by, but mostly out of our forecast area. Have maintained some 20% PoP`s along the southern CWA border Friday afternoon, but kept Saturday dry for now. LONG TERM...Sunday through Wednesday: Upper ridging breaks down during the weekend with more of a southwest flow across the nation early next week, and the northern jet stream along the Canadian border. Right now the ECMWF is the odd model out in developing an upper low over the upper Mississippi Valley which slowly drifts eastward through the Great Lakes during the week, while the GFS, GEM and GFS ensembles have more of periodic shortwave interaction between the two upper flows. Sunday into early Monday are in most agreement with rain chances, but trends widen after that. The ECMWF and the GEM to an extent have the surface cyclone somewhat in agreement into Tuesday with the cold front coming through, which would support the rain chances continuing. Toward mid week, there is much more uncertainty as the GFS never actually brings the front through and holds it up near I-80, thus lingering rain chances, while the ECMWF is dry. Have kept some PoP`s in for Wednesday for now, but scaled them back from the initial blended guidance. Geelhart && .AVIATION... ISSUED 1150 PM CDT Wed May 28 2014 The potential for some MVFR fog will increase after 08z for PIA and BMI as those terminal sites received the most rain today. Also, their dew point spreads are beginning to fall. BMI is 5 deg and PIA is still 7 deg, but upstream trends show potential for fog. La Salle/Peru is down to 4SM BR already. The other TAF sites did not see much in the way of rain today, so any vis reduction from fog should generally remain VFR. Convection is forecast to develop north of the front tomorrow, mainly from late morning through late afternoon. Storms could reach as far north as BMI, but higher potential should remain south of I-72. We included VCTS for storms only at SPI and DEC, with VCSH for showers at CMI and BMI. PIA was left dry as they should be far enough north of the cold front with dry low levels filtering into N IL under high pressure. Winds will remain light from the E-NE the rest of tonight. Thursday morning, wind directions should veer to the east- southeast during the day, but return to E-NE after 00z/7pm Thur. Speeds are expected to generally remain less than 10kt under a weak surface pressure gradient and wind speeds aloft. Shimon && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
206 PM EDT THU MAY 29 2014 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 317 AM EDT THU MAY 29 2014 SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY AS A SLOW MOVING FRONT DROPS SOUTH. THE FRONT WILL EVENTUALLY SLIP SOUTH OF THE OHIO RIVER TONIGHT AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. WARM DRY WEATHER IS ANTICIPATED INTO SUNDAY AS THE HIGH CENTERS OVER THE REGION. A MORE UNSETTLED PATTERN RETURNS FOR THE FIRST HALF OF NEXT WEEK WITH CHANCES FOR THUNDERSTORMS. && .NEAR TERM /REST OF TODAY/... ISSUED AT 937 AM EDT THU MAY 29 2014 1330Z UPDATE...FEW CHANGES TO GOING FORECAST...MAINLY TO ACCOUNT FOR MUCH DRIER TREND EARLY THIS MORNING AND TO DROP FOG FROM FORECAST. OTHERWISE FORECAST LOOKS TO BE IN PRETTY GOOD SHAPE. PREVIOUS DISCUSSION FOLLOWS. ANOTHER STICKY MORNING WITH PLENTY OF CLOUD DEBRIS ACROSS THE REGION. CONVECTION HAS LARGELY DIMINISHED WITH THE EXCEPTION OF A SMALL PERSISTENT CELL NEAR KMIE WHICH WAS FINALLY WEAKENING. TEMPS WERE GENERALLY IN THE 60S AS OF 07Z WITH PATCHY FOG DEVELOPING IN AREAS THAT RECEIVED RAIN ON WEDNESDAY. THE CATALYSTS FOR CONVECTIVE DEVELOPMENT WILL BE THE SAME AS THEY HAVE BEEN THE LAST FEW DAYS...MODEST INSTABILITY AND THE PRESENCE OF THE SLOWLY SOUTHWARD MOVING FRONTAL BOUNDARY. A REMNANT OUTFLOW BOUNDARY THAT APPEARS TO BE LOCATED FROM NEAR KHUF SOUTHEAST TO KBMG AND SEYMOUR IS THE WILDCARD TODAY...AS IT WILL LIKELY BE A FOCAL POINT FOR STORMS TO FIRE ONCE CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. SHORT RANGE MODEL GUIDANCE ALSO HINTING AT A WEAK AXIS OF MID LEVEL FORCING ALIGNING NORTHWEST-SOUTHEAST ACROSS THE CENTER OF THE FORECAST AREA THIS AFTERNOON BEFORE GRADUALLY SHIFTING SOUTH. WHILE THE GREATEST CONVECTIVE COVERAGE WILL BE FOUND PRIMARILY SOUTH OF I-70...THE PRESENCE OF THE WEAK FORCING ALOFT SUPPORTS SCATTERED CONVECTION ALL THE WAY NORTH TO A CRAWFORDSVILLE-NOBLESVILLE- ANDERSON LINE. HRRR AND WRF REFLECTIVITY PROGS FOR THIS AFTERNOON BOTH SUPPORT THIS IDEA IN THE 18-21Z TIME PERIOD BEFORE SHIFTING STORMS SOUTH AS DRIER AIR ATTEMPTS TO ADVECT IN FROM THE NORTHEAST. WILL CARRY CHANCE POPS FOR ALL BUT THE FAR NORTHERN COUNTIES TODAY...WITH HIGHEST POPS DURING THE AFTERNOON AND ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. LARGELY DISORGANIZED MULTICELLULAR CONVECTION ONCE AGAIN FAVORED IN THE ABSENCE OF BL SHEAR...WITH TORRENTIAL RAINFALL AND LOCALIZED FLOODING THE PRIMARY IMPACT AS STORM MOTIONS WILL BE GENERALLY 10KTS OR LESS. TEMPS...DEPENDING ON HOW QUICKLY STORMS GET GOING...POTENTIAL EXISTS FOR TEMPS TO OVERACHIEVE A BIT TODAY. WENT AT OR JUST ABOVE WARMER MAVMOS. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... ISSUED AT 317 AM EDT THU MAY 29 2014 FORECAST CHALLENGES ARE FEW THROUGH THE PERIOD...AS HIGH PRESSURE ASSERTS CONTROL OVER THE REGION FOR MUCH OF THE SHORT TERM. ANTICIPATE LINGERING CONVECTION FOCUSED OVER SOUTHERN COUNTIES NEAR THE REMNANT FRONTAL BOUNDARY THIS EVENING...WITH STORMS DIMINISHING BY MIDNIGHT AS THE AIRMASS STABILIZES AND PROGRESSIVELY DRIER AIR SPREADS IN WITH THE HIGH PRESSURE TO THE NORTH. DEEPER MOISTURE AXIS WILL REMAIN JUST TO THE SOUTHWEST OF THE FORECAST AREA ON FRIDAY...CLOSE ENOUGH THAT AN ISOLATED STORM CANNOT BE ENTIRELY RULED OUT OVER THE EXTREME SOUTHWEST FORECAST AREA. HOWEVER WITH COVERAGE SPARSE AT BEST WILL MAINTAIN A DRY FORECAST. OVER THE REMAINDER OF THE FORECAST AREA...THE SURFACE HIGH WILL TAKE ROOT WITH STRONG RIDGING ALOFT ESTABLISHING AS WELL. MODEL SOUNDINGS AND RH PROGS INDICATE DEEP SUBSIDENCE ACCOMPANYING THE HIGH WITH ABUNDANT SUNSHINE ANTICIPATED FRIDAY AND SATURDAY AS A PREDOMINANT DRY E/NE FLOW CONTINUES. ALL IN ALL...SHAPING UP TO BE A GREAT WEEKEND FOR CENTRAL INDIANA. TEMPS...DESPITE SLIGHTLY COOLER 850MB TEMPS FRIDAY AND SATURDAY... PRESENCE OF THE UPPER RIDGE AND ABUNDANT SUNSHINE WILL COMPENSATE WITH HIGHS INTO THE 80S FRIDAY AND SATURDAY. LEANED TOWARDS WARMER MAVMOS GUIDANCE BOTH DAYS. EXPECT LOWS INTO THE 50S IN SOME OF OUR NORMAL COOL SPOTS BOTH TONIGHT AND FRIDAY NIGHT...ESPECIALLY NORTH AND EAST OF THE INDY METRO. WENT ABOVE GUIDANCE AT INDY FOR LOWS TONIGHT AND FRIDAY NIGHT WITH A LIGHT E/NE FLOW. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 202 PM EDT THU MAY 29 2014 UNSETTLED...WARM AND HUMID WEATHER APPEARS IN STORE FOR MUCH OF NEXT WEEK. ECMWF AND GFS HINT AT RIDGING SETTING UP ALOFT EAST OF INDIANA...ALLOWING A WARM AND HUMID AIR MASS TO ARRIVE IN THE OHIO VALLEY ON SOUTHERLY WINDS. UPPER SUPPORT THROUGH THE PERIOD IS UNORGANIZED AS A FEW WEAK SHORT WAVES APPEAR TO PUSH OUT OF THE CENTRAL PLAINS INTO THE OHIO VALLEY...HOWEVER...CONFIDENCE REMAINS QUITE LOW. HOWEVER GIVEN THE VERY WARM AND MOIST AIR MASS THAT WILL BE IN PLACE...DIURNAL SHRA AND TSRA WILL NOT BE OUT OF THE QUESTION. THUS WILL TREND TOWARD DAILY CHANCES WITH ABOVE NORMAL HIGHS AND ABOVE NORMAL LOWS. && .AVIATION /DISCUSSION FOR THE 291800Z IND TAFS/... ISSUED AT 1210 PM EDT THU MAY 29 2014 MAINLY VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD...HOWEVER BRIEF MVFR CONDITIONS WILL BE POSSIBLE WITH ANY TSRA THAT DOES STRIKE A TAF SITE. ALSO VFR CONDITIONS WILL BE POSSIBLE LATE TONIGHT DUE TO DIURNAL FOG. WEAK...POORLY DEFINED COLD FRONTAL BOUNDARY STILL LINGERING ACROSS CENTRAL INDIANA EARLY THIS AFTERNOON. FORECAST SOUNDINGS STILL REVEAL A CONDITIONALLY UNSTABLE...MOIST AIR MASS OVER THE TAF SITES. AS CONVECTIVE TEMPERATURES ARE REACHED THIS AFTERNOON...EXPECT DIURNALLY DRIVEN SCT SHRA/TSRA TO DEVELOP THROUGH THE PEAK HEATING HOURS OF THE AFTERNOON. WILL CONTINUE TO USE VCTS TO COVER THIS FOR NOW...BUT WILL UPDATE TAFS QUICKLY IF A STRIKE ON A TAF SITE APPEARS IMMINENT. AFTER HEATING IS LOST THIS EVENING...CONVECTIVE ACTIVITY WILL DISSIPATE AS SUGGESTED BY THE HRRR. TIME HEIGHTS AND FORECAST SOUNDINGS THEN SHOW DRYER AIR WORKING INTO THE STATE ON EASTERLY WINDS AS THE COLD FRONT SAGS SLOWLY SOUTHWARD. ANY SPOT THAT DOES RECEIVE RAIN THIS AFTERNOON MAY HAVE ENOUGH MOISTURE TO RESULT IN PATCHY MVFR FOG OVERNIGHT DUE TO GOOD LOWER LEVEL MOISTURE AND IDEAL RADIATIONAL COOLING CONDITIONS. AMID DRY AIR ON FRIDAY...CONVECTIVE TEMPERATURES ARE EXPECTED TO BE TOO WARM AND CU DEVELOPMENT IS NOT EXPECTED. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM....PUMA AVIATION...JP 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 INDIANAPOLIS IN
1227 PM EDT THU MAY 29 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 317 AM EDT THU MAY 29 2014 SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY AS A SLOW MOVING FRONT DROPS SOUTH. THE FRONT WILL EVENTUALLY SLIP SOUTH OF THE OHIO RIVER TONIGHT AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. WARM DRY WEATHER IS ANTICIPATED INTO SUNDAY AS THE HIGH CENTERS OVER THE REGION. A MORE UNSETTLED PATTERN RETURNS FOR THE FIRST HALF OF NEXT WEEK WITH CHANCES FOR THUNDERSTORMS. && .NEAR TERM /REST OF TODAY/... ISSUED AT 937 AM EDT THU MAY 29 2014 1330Z UPDATE...FEW CHANGES TO GOING FORECAST...MAINLY TO ACCOUNT FOR MUCH DRIER TREND EARLY THIS MORNING AND TO DROP FOG FROM FORECAST. OTHERWISE FORECAST LOOKS TO BE IN PRETTY GOOD SHAPE. PREVIOUS DISCUSSION FOLLOWS. ANOTHER STICKY MORNING WITH PLENTY OF CLOUD DEBRIS ACROSS THE REGION. CONVECTION HAS LARGELY DIMINISHED WITH THE EXCEPTION OF A SMALL PERSISTENT CELL NEAR KMIE WHICH WAS FINALLY WEAKENING. TEMPS WERE GENERALLY IN THE 60S AS OF 07Z WITH PATCHY FOG DEVELOPING IN AREAS THAT RECEIVED RAIN ON WEDNESDAY. THE CATALYSTS FOR CONVECTIVE DEVELOPMENT WILL BE THE SAME AS THEY HAVE BEEN THE LAST FEW DAYS...MODEST INSTABILITY AND THE PRESENCE OF THE SLOWLY SOUTHWARD MOVING FRONTAL BOUNDARY. A REMNANT OUTFLOW BOUNDARY THAT APPEARS TO BE LOCATED FROM NEAR KHUF SOUTHEAST TO KBMG AND SEYMOUR IS THE WILDCARD TODAY...AS IT WILL LIKELY BE A FOCAL POINT FOR STORMS TO FIRE ONCE CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. SHORT RANGE MODEL GUIDANCE ALSO HINTING AT A WEAK AXIS OF MID LEVEL FORCING ALIGNING NORTHWEST-SOUTHEAST ACROSS THE CENTER OF THE FORECAST AREA THIS AFTERNOON BEFORE GRADUALLY SHIFTING SOUTH. WHILE THE GREATEST CONVECTIVE COVERAGE WILL BE FOUND PRIMARILY SOUTH OF I-70...THE PRESENCE OF THE WEAK FORCING ALOFT SUPPORTS SCATTERED CONVECTION ALL THE WAY NORTH TO A CRAWFORDSVILLE-NOBLESVILLE- ANDERSON LINE. HRRR AND WRF REFLECTIVITY PROGS FOR THIS AFTERNOON BOTH SUPPORT THIS IDEA IN THE 18-21Z TIME PERIOD BEFORE SHIFTING STORMS SOUTH AS DRIER AIR ATTEMPTS TO ADVECT IN FROM THE NORTHEAST. WILL CARRY CHANCE POPS FOR ALL BUT THE FAR NORTHERN COUNTIES TODAY...WITH HIGHEST POPS DURING THE AFTERNOON AND ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. LARGELY DISORGANIZED MULTICELLULAR CONVECTION ONCE AGAIN FAVORED IN THE ABSENCE OF BL SHEAR...WITH TORRENTIAL RAINFALL AND LOCALIZED FLOODING THE PRIMARY IMPACT AS STORM MOTIONS WILL BE GENERALLY 10KTS OR LESS. TEMPS...DEPENDING ON HOW QUICKLY STORMS GET GOING...POTENTIAL EXISTS FOR TEMPS TO OVERACHIEVE A BIT TODAY. WENT AT OR JUST ABOVE WARMER MAVMOS. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... ISSUED AT 317 AM EDT THU MAY 29 2014 FORECAST CHALLENGES ARE FEW THROUGH THE PERIOD...AS HIGH PRESSURE ASSERTS CONTROL OVER THE REGION FOR MUCH OF THE SHORT TERM. ANTICIPATE LINGERING CONVECTION FOCUSED OVER SOUTHERN COUNTIES NEAR THE REMNANT FRONTAL BOUNDARY THIS EVENING...WITH STORMS DIMINISHING BY MIDNIGHT AS THE AIRMASS STABILIZES AND PROGRESSIVELY DRIER AIR SPREADS IN WITH THE HIGH PRESSURE TO THE NORTH. DEEPER MOISTURE AXIS WILL REMAIN JUST TO THE SOUTHWEST OF THE FORECAST AREA ON FRIDAY...CLOSE ENOUGH THAT AN ISOLATED STORM CANNOT BE ENTIRELY RULED OUT OVER THE EXTREME SOUTHWEST FORECAST AREA. HOWEVER WITH COVERAGE SPARSE AT BEST WILL MAINTAIN A DRY FORECAST. OVER THE REMAINDER OF THE FORECAST AREA...THE SURFACE HIGH WILL TAKE ROOT WITH STRONG RIDGING ALOFT ESTABLISHING AS WELL. MODEL SOUNDINGS AND RH PROGS INDICATE DEEP SUBSIDENCE ACCOMPANYING THE HIGH WITH ABUNDANT SUNSHINE ANTICIPATED FRIDAY AND SATURDAY AS A PREDOMINANT DRY E/NE FLOW CONTINUES. ALL IN ALL...SHAPING UP TO BE A GREAT WEEKEND FOR CENTRAL INDIANA. TEMPS...DESPITE SLIGHTLY COOLER 850MB TEMPS FRIDAY AND SATURDAY... PRESENCE OF THE UPPER RIDGE AND ABUNDANT SUNSHINE WILL COMPENSATE WITH HIGHS INTO THE 80S FRIDAY AND SATURDAY. LEANED TOWARDS WARMER MAVMOS GUIDANCE BOTH DAYS. EXPECT LOWS INTO THE 50S IN SOME OF OUR NORMAL COOL SPOTS BOTH TONIGHT AND FRIDAY NIGHT...ESPECIALLY NORTH AND EAST OF THE INDY METRO. WENT ABOVE GUIDANCE AT INDY FOR LOWS TONIGHT AND FRIDAY NIGHT WITH A LIGHT E/NE FLOW. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 AN UPPER RIDGE OVER CENTRAL INDIANA WILL MOVE EAST AND WIND UP OFF THE EAST COAST BY THE END OF THE LONG TERM. AN UPPER TROUGH OVER THE WESTERN U.S. WILL ALLOW WEAK SHORTWAVES TO MOVE THROUGH THE FLOW AND BRING THUNDERSTORM CHANCES TO CENTRAL INDIANA THROUGHOUT THE LONG TERM. WITH THE SOUTHWESTERLY FLOW OVER THE AREA CONDITIONS WILL REMAIN WARM AND HUMID AS THE GULF REMAINS OPEN. NO STRONG FEATURES TO FOCUS ON SO STUCK WITH INITIALIZATION CHANCE POPS FROM SUNDAY NIGHT ON. FOR SUNDAY MORNING THE UPPER RIDGE WILL JUST BE STARTING TO MOVE EAST AND THUS THINK PRECIPITATION WILL HAVE A HARD TIME MOVING EAST INTO THE AREA UNDER UPPER SUBSIDENCE. THUS WENT DRY FOR SUNDAY MORNING AND BROUGHT IN LOW CHANCE POPS IN THE WEST IN THE AFTERNOON. && .AVIATION /DISCUSSION FOR THE 291800Z IND TAFS/... ISSUED AT 1210 PM EDT THU MAY 29 2014 MAINLY VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD...HOWEVER BRIEF MVFR CONDITIONS WILL BE POSSIBLE WITH ANY TSRA THAT DOES STRIKE A TAF SITE. ALSO VFR CONDITIONS WILL BE POSSIBLE LATE TONIGHT DUE TO DIURNAL FOG. WEAK...POORLY DEFINED COLD FRONTAL BOUNDARY STILL LINGERING ACROSS CENTRAL INDIANA EARLY THIS AFTERNOON. FORECAST SOUNDINGS STILL REVEAL A CONDITIONALLY UNSTABLE...MOIST AIR MASS OVER THE TAF SITES. AS CONVECTIVE TEMPERATURES ARE REACHED THIS AFTERNOON...EXPECT DIURNALLY DRIVEN SCT SHRA/TSRA TO DEVELOP THROUGH THE PEAK HEATING HOURS OF THE AFTERNOON. WILL CONTINUE TO USE VCTS TO COVER THIS FOR NOW...BUT WILL UPDATE TAFS QUICKLY IF A STRIKE ON A TAF SITE APPEARS IMMINENT. AFTER HEATING IS LOST THIS EVENING...CONVECTIVE ACTIVITY WILL DISSIPATE AS SUGGESTED BY THE HRRR. TIME HEIGHTS AND FORECAST SOUNDINGS THEN SHOW DRYER AIR WORKING INTO THE STATE ON EASTERLY WINDS AS THE COLD FRONT SAGS SLOWLY SOUTHWARD. ANY SPOT THAT DOES RECEIVE RAIN THIS AFTERNOON MAY HAVE ENOUGH MOISTURE TO RESULT IN PATCHY MVFR FOG OVERNIGHT DUE TO GOOD LOWER LEVEL MOISTURE AND IDEAL RADIATIONAL COOLING CONDITIONS. AMID DRY AIR ON FRIDAY...CONVECTIVE TEMPERATURES ARE EXPECTED TO BE TOO WARM AND CU DEVELOPMENT IS NOT EXPECTED. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...JP 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 INDIANAPOLIS IN
1028 AM EDT THU MAY 29 2014 .UPDATE... AVIATION SECTION UPDATED. && .SYNOPSIS... ISSUED AT 317 AM EDT THU MAY 29 2014 SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY AS A SLOW MOVING FRONT DROPS SOUTH. THE FRONT WILL EVENTUALLY SLIP SOUTH OF THE OHIO RIVER TONIGHT AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. WARM DRY WEATHER IS ANTICIPATED INTO SUNDAY AS THE HIGH CENTERS OVER THE REGION. A MORE UNSETTLED PATTERN RETURNS FOR THE FIRST HALF OF NEXT WEEK WITH CHANCES FOR THUNDERSTORMS. && .NEAR TERM /REST OF TODAY/... ISSUED AT 937 AM EDT THU MAY 29 2014 1330Z UPDATE...FEW CHANGES TO GOING FORECAST...MAINLY TO ACCOUNT FOR MUCH DRIER TREND EARLY THIS MORNING AND TO DROP FOG FROM FORECAST. OTHERWISE FORECAST LOOKS TO BE IN PRETTY GOOD SHAPE. PREVIOUS DISCUSSION FOLLOWS. ANOTHER STICKY MORNING WITH PLENTY OF CLOUD DEBRIS ACROSS THE REGION. CONVECTION HAS LARGELY DIMINISHED WITH THE EXCEPTION OF A SMALL PERSISTENT CELL NEAR KMIE WHICH WAS FINALLY WEAKENING. TEMPS WERE GENERALLY IN THE 60S AS OF 07Z WITH PATCHY FOG DEVELOPING IN AREAS THAT RECEIVED RAIN ON WEDNESDAY. THE CATALYSTS FOR CONVECTIVE DEVELOPMENT WILL BE THE SAME AS THEY HAVE BEEN THE LAST FEW DAYS...MODEST INSTABILITY AND THE PRESENCE OF THE SLOWLY SOUTHWARD MOVING FRONTAL BOUNDARY. A REMNANT OUTFLOW BOUNDARY THAT APPEARS TO BE LOCATED FROM NEAR KHUF SOUTHEAST TO KBMG AND SEYMOUR IS THE WILDCARD TODAY...AS IT WILL LIKELY BE A FOCAL POINT FOR STORMS TO FIRE ONCE CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. SHORT RANGE MODEL GUIDANCE ALSO HINTING AT A WEAK AXIS OF MID LEVEL FORCING ALIGNING NORTHWEST-SOUTHEAST ACROSS THE CENTER OF THE FORECAST AREA THIS AFTERNOON BEFORE GRADUALLY SHIFTING SOUTH. WHILE THE GREATEST CONVECTIVE COVERAGE WILL BE FOUND PRIMARILY SOUTH OF I-70...THE PRESENCE OF THE WEAK FORCING ALOFT SUPPORTS SCATTERED CONVECTION ALL THE WAY NORTH TO A CRAWFORDSVILLE-NOBLESVILLE- ANDERSON LINE. HRRR AND WRF REFLECTIVITY PROGS FOR THIS AFTERNOON BOTH SUPPORT THIS IDEA IN THE 18-21Z TIME PERIOD BEFORE SHIFTING STORMS SOUTH AS DRIER AIR ATTEMPTS TO ADVECT IN FROM THE NORTHEAST. WILL CARRY CHANCE POPS FOR ALL BUT THE FAR NORTHERN COUNTIES TODAY...WITH HIGHEST POPS DURING THE AFTERNOON AND ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. LARGELY DISORGANIZED MULTICELLULAR CONVECTION ONCE AGAIN FAVORED IN THE ABSENCE OF BL SHEAR...WITH TORRENTIAL RAINFALL AND LOCALIZED FLOODING THE PRIMARY IMPACT AS STORM MOTIONS WILL BE GENERALLY 10KTS OR LESS. TEMPS...DEPENDING ON HOW QUICKLY STORMS GET GOING...POTENTIAL EXISTS FOR TEMPS TO OVERACHIEVE A BIT TODAY. WENT AT OR JUST ABOVE WARMER MAVMOS. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... ISSUED AT 317 AM EDT THU MAY 29 2014 FORECAST CHALLENGES ARE FEW THROUGH THE PERIOD...AS HIGH PRESSURE ASSERTS CONTROL OVER THE REGION FOR MUCH OF THE SHORT TERM. ANTICIPATE LINGERING CONVECTION FOCUSED OVER SOUTHERN COUNTIES NEAR THE REMNANT FRONTAL BOUNDARY THIS EVENING...WITH STORMS DIMINISHING BY MIDNIGHT AS THE AIRMASS STABILIZES AND PROGRESSIVELY DRIER AIR SPREADS IN WITH THE HIGH PRESSURE TO THE NORTH. DEEPER MOISTURE AXIS WILL REMAIN JUST TO THE SOUTHWEST OF THE FORECAST AREA ON FRIDAY...CLOSE ENOUGH THAT AN ISOLATED STORM CANNOT BE ENTIRELY RULED OUT OVER THE EXTREME SOUTHWEST FORECAST AREA. HOWEVER WITH COVERAGE SPARSE AT BEST WILL MAINTAIN A DRY FORECAST. OVER THE REMAINDER OF THE FORECAST AREA...THE SURFACE HIGH WILL TAKE ROOT WITH STRONG RIDGING ALOFT ESTABLISHING AS WELL. MODEL SOUNDINGS AND RH PROGS INDICATE DEEP SUBSIDENCE ACCOMPANYING THE HIGH WITH ABUNDANT SUNSHINE ANTICIPATED FRIDAY AND SATURDAY AS A PREDOMINANT DRY E/NE FLOW CONTINUES. ALL IN ALL...SHAPING UP TO BE A GREAT WEEKEND FOR CENTRAL INDIANA. TEMPS...DESPITE SLIGHTLY COOLER 850MB TEMPS FRIDAY AND SATURDAY... PRESENCE OF THE UPPER RIDGE AND ABUNDANT SUNSHINE WILL COMPENSATE WITH HIGHS INTO THE 80S FRIDAY AND SATURDAY. LEANED TOWARDS WARMER MAVMOS GUIDANCE BOTH DAYS. EXPECT LOWS INTO THE 50S IN SOME OF OUR NORMAL COOL SPOTS BOTH TONIGHT AND FRIDAY NIGHT...ESPECIALLY NORTH AND EAST OF THE INDY METRO. WENT ABOVE GUIDANCE AT INDY FOR LOWS TONIGHT AND FRIDAY NIGHT WITH A LIGHT E/NE FLOW. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 AN UPPER RIDGE OVER CENTRAL INDIANA WILL MOVE EAST AND WIND UP OFF THE EAST COAST BY THE END OF THE LONG TERM. AN UPPER TROUGH OVER THE WESTERN U.S. WILL ALLOW WEAK SHORTWAVES TO MOVE THROUGH THE FLOW AND BRING THUNDERSTORM CHANCES TO CENTRAL INDIANA THROUGHOUT THE LONG TERM. WITH THE SOUTHWESTERLY FLOW OVER THE AREA CONDITIONS WILL REMAIN WARM AND HUMID AS THE GULF REMAINS OPEN. NO STRONG FEATURES TO FOCUS ON SO STUCK WITH INITIALIZATION CHANCE POPS FROM SUNDAY NIGHT ON. FOR SUNDAY MORNING THE UPPER RIDGE WILL JUST BE STARTING TO MOVE EAST AND THUS THINK PRECIPITATION WILL HAVE A HARD TIME MOVING EAST INTO THE AREA UNDER UPPER SUBSIDENCE. THUS WENT DRY FOR SUNDAY MORNING AND BROUGHT IN LOW CHANCE POPS IN THE WEST IN THE AFTERNOON. && .AVIATION /DISCUSSION FOR THE 291200Z IND TAF UPDATE/... ONGOING TAF IS GOOD SHAPE AND ONLY MINOR CHANGES HAVE BEEN MADE. CONVECTIVE TEMPS IN THE UPPER 70S SHOULD BE EASILY REACHED LATE THIS MORNING AND CU DEVELOPMENT SHOULD BEGIN. HRRR CONTINUES TO SUGGEST SCT SHRA/TSRA DEVELOPMENT THIS AFTERNOON IN THE I-70 CORRIDOR...THUS WILL CONTINUE THE USE OF VCTS FOR NOW. PREVIOUS DISCUSSION BELOW /DISCUSSION FOR 291200Z TAF ISSUANCE/... ISSUED AT 652 AM EDT THU MAY 29 2014 COULD HAVE AN HOUR OR SO OF MVFR FOG AT THE OUTLYING SITES. AT KLAF SHOULD SEE IFR CEILINGS STICK AROUND FOR A COUPLE HOURS BEFORE IT MIXES UP AND SCATTERS OUT. AFTER THAT WILL SEE SOME CHANCES FOR THUNDERSTORMS DURING THE AFTERNOON AND EVENING AT ALL BUT KLAF WITH THE COLD FRONT SLOWLY SINKING SOUTH THROUGH CENTRAL/SOUTHERN INDIANA. HRRR AND RAP SHOW QPF DEVELOPING ALONG/SOUTH OF I-70 STARTING AFTER 18Z OR SO AND LASTING THROUGH AROUND 1Z AND INCLUDED VCTS DURING THIS TIME. COULD SEE MVFR VISIBILITIES AND POSSIBLY CEILINGS DEVELOP AGAIN DURING THE OVERNIGHT HOURS. WINDS LESS THAN 10 KTS THROUGH THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...CP/JP 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 INDIANAPOLIS IN
940 AM EDT THU MAY 29 2014 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 317 AM EDT THU MAY 29 2014 SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY AS A SLOW MOVING FRONT DROPS SOUTH. THE FRONT WILL EVENTUALLY SLIP SOUTH OF THE OHIO RIVER TONIGHT AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. WARM DRY WEATHER IS ANTICIPATED INTO SUNDAY AS THE HIGH CENTERS OVER THE REGION. A MORE UNSETTLED PATTERN RETURNS FOR THE FIRST HALF OF NEXT WEEK WITH CHANCES FOR THUNDERSTORMS. && .NEAR TERM /REST OF TODAY/... ISSUED AT 937 AM EDT THU MAY 29 2014 1330Z UPDATE...FEW CHANGES TO GOING FORECAST...MAINLY TO ACCOUNT FOR MUCH DRIER TREND EARLY THIS MORNING AND TO DROP FOG FROM FORECAST. OTHERWISE FORECAST LOOKS TO BE IN PRETTY GOOD SHAPE. PREVIOUS DISCUSSION FOLLOWS. ANOTHER STICKY MORNING WITH PLENTY OF CLOUD DEBRIS ACROSS THE REGION. CONVECTION HAS LARGELY DIMINISHED WITH THE EXCEPTION OF A SMALL PERSISTENT CELL NEAR KMIE WHICH WAS FINALLY WEAKENING. TEMPS WERE GENERALLY IN THE 60S AS OF 07Z WITH PATCHY FOG DEVELOPING IN AREAS THAT RECEIVED RAIN ON WEDNESDAY. THE CATALYSTS FOR CONVECTIVE DEVELOPMENT WILL BE THE SAME AS THEY HAVE BEEN THE LAST FEW DAYS...MODEST INSTABILITY AND THE PRESENCE OF THE SLOWLY SOUTHWARD MOVING FRONTAL BOUNDARY. A REMNANT OUTFLOW BOUNDARY THAT APPEARS TO BE LOCATED FROM NEAR KHUF SOUTHEAST TO KBMG AND SEYMOUR IS THE WILDCARD TODAY...AS IT WILL LIKELY BE A FOCAL POINT FOR STORMS TO FIRE ONCE CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. SHORT RANGE MODEL GUIDANCE ALSO HINTING AT A WEAK AXIS OF MID LEVEL FORCING ALIGNING NORTHWEST-SOUTHEAST ACROSS THE CENTER OF THE FORECAST AREA THIS AFTERNOON BEFORE GRADUALLY SHIFTING SOUTH. WHILE THE GREATEST CONVECTIVE COVERAGE WILL BE FOUND PRIMARILY SOUTH OF I-70...THE PRESENCE OF THE WEAK FORCING ALOFT SUPPORTS SCATTERED CONVECTION ALL THE WAY NORTH TO A CRAWFORDSVILLE-NOBLESVILLE- ANDERSON LINE. HRRR AND WRF REFLECTIVITY PROGS FOR THIS AFTERNOON BOTH SUPPORT THIS IDEA IN THE 18-21Z TIME PERIOD BEFORE SHIFTING STORMS SOUTH AS DRIER AIR ATTEMPTS TO ADVECT IN FROM THE NORTHEAST. WILL CARRY CHANCE POPS FOR ALL BUT THE FAR NORTHERN COUNTIES TODAY...WITH HIGHEST POPS DURING THE AFTERNOON AND ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. LARGELY DISORGANIZED MULTICELLULAR CONVECTION ONCE AGAIN FAVORED IN THE ABSENCE OF BL SHEAR...WITH TORRENTIAL RAINFALL AND LOCALIZED FLOODING THE PRIMARY IMPACT AS STORM MOTIONS WILL BE GENERALLY 10KTS OR LESS. TEMPS...DEPENDING ON HOW QUICKLY STORMS GET GOING...POTENTIAL EXISTS FOR TEMPS TO OVERACHIEVE A BIT TODAY. WENT AT OR JUST ABOVE WARMER MAVMOS. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... ISSUED AT 317 AM EDT THU MAY 29 2014 FORECAST CHALLENGES ARE FEW THROUGH THE PERIOD...AS HIGH PRESSURE ASSERTS CONTROL OVER THE REGION FOR MUCH OF THE SHORT TERM. ANTICIPATE LINGERING CONVECTION FOCUSED OVER SOUTHERN COUNTIES NEAR THE REMNANT FRONTAL BOUNDARY THIS EVENING...WITH STORMS DIMINISHING BY MIDNIGHT AS THE AIRMASS STABILIZES AND PROGRESSIVELY DRIER AIR SPREADS IN WITH THE HIGH PRESSURE TO THE NORTH. DEEPER MOISTURE AXIS WILL REMAIN JUST TO THE SOUTHWEST OF THE FORECAST AREA ON FRIDAY...CLOSE ENOUGH THAT AN ISOLATED STORM CANNOT BE ENTIRELY RULED OUT OVER THE EXTREME SOUTHWEST FORECAST AREA. HOWEVER WITH COVERAGE SPARSE AT BEST WILL MAINTAIN A DRY FORECAST. OVER THE REMAINDER OF THE FORECAST AREA...THE SURFACE HIGH WILL TAKE ROOT WITH STRONG RIDGING ALOFT ESTABLISHING AS WELL. MODEL SOUNDINGS AND RH PROGS INDICATE DEEP SUBSIDENCE ACCOMPANYING THE HIGH WITH ABUNDANT SUNSHINE ANTICIPATED FRIDAY AND SATURDAY AS A PREDOMINANT DRY E/NE FLOW CONTINUES. ALL IN ALL...SHAPING UP TO BE A GREAT WEEKEND FOR CENTRAL INDIANA. TEMPS...DESPITE SLIGHTLY COOLER 850MB TEMPS FRIDAY AND SATURDAY... PRESENCE OF THE UPPER RIDGE AND ABUNDANT SUNSHINE WILL COMPENSATE WITH HIGHS INTO THE 80S FRIDAY AND SATURDAY. LEANED TOWARDS WARMER MAVMOS GUIDANCE BOTH DAYS. EXPECT LOWS INTO THE 50S IN SOME OF OUR NORMAL COOL SPOTS BOTH TONIGHT AND FRIDAY NIGHT...ESPECIALLY NORTH AND EAST OF THE INDY METRO. WENT ABOVE GUIDANCE AT INDY FOR LOWS TONIGHT AND FRIDAY NIGHT WITH A LIGHT E/NE FLOW. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 AN UPPER RIDGE OVER CENTRAL INDIANA WILL MOVE EAST AND WIND UP OFF THE EAST COAST BY THE END OF THE LONG TERM. AN UPPER TROUGH OVER THE WESTERN U.S. WILL ALLOW WEAK SHORTWAVES TO MOVE THROUGH THE FLOW AND BRING THUNDERSTORM CHANCES TO CENTRAL INDIANA THROUGHOUT THE LONG TERM. WITH THE SOUTHWESTERLY FLOW OVER THE AREA CONDITIONS WILL REMAIN WARM AND HUMID AS THE GULF REMAINS OPEN. NO STRONG FEATURES TO FOCUS ON SO STUCK WITH INITIALIZATION CHANCE POPS FROM SUNDAY NIGHT ON. FOR SUNDAY MORNING THE UPPER RIDGE WILL JUST BE STARTING TO MOVE EAST AND THUS THINK PRECIPITATION WILL HAVE A HARD TIME MOVING EAST INTO THE AREA UNDER UPPER SUBSIDENCE. THUS WENT DRY FOR SUNDAY MORNING AND BROUGHT IN LOW CHANCE POPS IN THE WEST IN THE AFTERNOON. && .AVIATION /DISCUSSION FOR 291200Z TAF ISSUANCE/... ISSUED AT 652 AM EDT THU MAY 29 2014 COULD HAVE AN HOUR OR SO OF MVFR FOG AT THE OUTLYING SITES. AT KLAF SHOULD SEE IFR CEILINGS STICK AROUND FOR A COUPLE HOURS BEFORE IT MIXES UP AND SCATTERS OUT. AFTER THAT WILL SEE SOME CHANCES FOR THUNDERSTORMS DURING THE AFTERNOON AND EVENING AT ALL BUT KLAF WITH THE COLD FRONT SLOWLY SINKING SOUTH THROUGH CENTRAL/SOUTHERN INDIANA. HRRR AND RAP SHOW QPF DEVELOPING ALONG/SOUTH OF I-70 STARTING AFTER 18Z OR SO AND LASTING THROUGH AROUND 1Z AND INCLUDED VCTS DURING THIS TIME. COULD SEE MVFR VISIBILITIES AND POSSIBLY CEILINGS DEVELOP AGAIN DURING THE OVERNIGHT HOURS. WINDS LESS THAN 10 KTS THROUGH THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...CP 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 INDIANAPOLIS IN
653 AM EDT THU MAY 29 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 317 AM EDT THU MAY 29 2014 SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY AS A SLOW MOVING FRONT DROPS SOUTH. THE FRONT WILL EVENTUALLY SLIP SOUTH OF THE OHIO RIVER TONIGHT AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. WARM DRY WEATHER IS ANTICIPATED INTO SUNDAY AS THE HIGH CENTERS OVER THE REGION. A MORE UNSETTLED PATTERN RETURNS FOR THE FIRST HALF OF NEXT WEEK WITH CHANCES FOR THUNDERSTORMS. && .NEAR TERM /TODAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 ANOTHER STICKY MORNING WITH PLENTY OF CLOUD DEBRIS ACROSS THE REGION. CONVECTION HAS LARGELY DIMINISHED WITH THE EXCEPTION OF A SMALL PERSISTENT CELL NEAR KMIE WHICH WAS FINALLY WEAKENING. TEMPS WERE GENERALLY IN THE 60S AS OF 07Z WITH PATCHY FOG DEVELOPING IN AREAS THAT RECEIVED RAIN ON WEDNESDAY. THE CATALYSTS FOR CONVECTIVE DEVELOPMENT WILL BE THE SAME AS THEY HAVE BEEN THE LAST FEW DAYS...MODEST INSTABILITY AND THE PRESENCE OF THE SLOWLY SOUTHWARD MOVING FRONTAL BOUNDARY. A REMNANT OUTFLOW BOUNDARY THAT APPEARS TO BE LOCATED FROM NEAR KHUF SOUTHEAST TO KBMG AND SEYMOUR IS THE WILDCARD TODAY...AS IT WILL LIKELY BE A FOCAL POINT FOR STORMS TO FIRE ONCE CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. SHORT RANGE MODEL GUIDANCE ALSO HINTING AT A WEAK AXIS OF MID LEVEL FORCING ALIGNING NORTHWEST-SOUTHEAST ACROSS THE CENTER OF THE FORECAST AREA THIS AFTERNOON BEFORE GRADUALLY SHIFTING SOUTH. WHILE THE GREATEST CONVECTIVE COVERAGE WILL BE FOUND PRIMARILY SOUTH OF I-70...THE PRESENCE OF THE WEAK FORCING ALOFT SUPPORTS SCATTERED CONVECTION ALL THE WAY NORTH TO A CRAWFORDSVILLE-NOBLESVILLE- ANDERSON LINE. HRRR AND WRF REFLECTIVITY PROGS FOR THIS AFTERNOON BOTH SUPPORT THIS IDEA IN THE 18-21Z TIME PERIOD BEFORE SHIFTING STORMS SOUTH AS DRIER AIR ATTEMPTS TO ADVECT IN FROM THE NORTHEAST. WILL CARRY CHANCE POPS FOR ALL BUT THE FAR NORTHERN COUNTIES TODAY...WITH HIGHEST POPS DURING THE AFTERNOON AND ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. LARGELY DISORGANIZED MULTICELLULAR CONVECTION ONCE AGAIN FAVORED IN THE ABSENCE OF BL SHEAR...WITH TORRENTIAL RAINFALL AND LOCALIZED FLOODING THE PRIMARY IMPACT AS STORM MOTIONS WILL BE GENERALLY 10KTS OR LESS. TEMPS...DEPENDING ON HOW QUICKLY STORMS GET GOING...POTENTIAL EXISTS FOR TEMPS TO OVERACHIEVE A BIT TODAY. WENT AT OR JUST ABOVE WARMER MAVMOS. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... ISSUED AT 317 AM EDT THU MAY 29 2014 FORECAST CHALLENGES ARE FEW THROUGH THE PERIOD...AS HIGH PRESSURE ASSERTS CONTROL OVER THE REGION FOR MUCH OF THE SHORT TERM. ANTICIPATE LINGERING CONVECTION FOCUSED OVER SOUTHERN COUNTIES NEAR THE REMNANT FRONTAL BOUNDARY THIS EVENING...WITH STORMS DIMINISHING BY MIDNIGHT AS THE AIRMASS STABILIZES AND PROGRESSIVELY DRIER AIR SPREADS IN WITH THE HIGH PRESSURE TO THE NORTH. DEEPER MOISTURE AXIS WILL REMAIN JUST TO THE SOUTHWEST OF THE FORECAST AREA ON FRIDAY...CLOSE ENOUGH THAT AN ISOLATED STORM CANNOT BE ENTIRELY RULED OUT OVER THE EXTREME SOUTHWEST FORECAST AREA. HOWEVER WITH COVERAGE SPARSE AT BEST WILL MAINTAIN A DRY FORECAST. OVER THE REMAINDER OF THE FORECAST AREA...THE SURFACE HIGH WILL TAKE ROOT WITH STRONG RIDGING ALOFT ESTABLISHING AS WELL. MODEL SOUNDINGS AND RH PROGS INDICATE DEEP SUBSIDENCE ACCOMPANYING THE HIGH WITH ABUNDANT SUNSHINE ANTICIPATED FRIDAY AND SATURDAY AS A PREDOMINANT DRY E/NE FLOW CONTINUES. ALL IN ALL...SHAPING UP TO BE A GREAT WEEKEND FOR CENTRAL INDIANA. TEMPS...DESPITE SLIGHTLY COOLER 850MB TEMPS FRIDAY AND SATURDAY... PRESENCE OF THE UPPER RIDGE AND ABUNDANT SUNSHINE WILL COMPENSATE WITH HIGHS INTO THE 80S FRIDAY AND SATURDAY. LEANED TOWARDS WARMER MAVMOS GUIDANCE BOTH DAYS. EXPECT LOWS INTO THE 50S IN SOME OF OUR NORMAL COOL SPOTS BOTH TONIGHT AND FRIDAY NIGHT...ESPECIALLY NORTH AND EAST OF THE INDY METRO. WENT ABOVE GUIDANCE AT INDY FOR LOWS TONIGHT AND FRIDAY NIGHT WITH A LIGHT E/NE FLOW. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 AN UPPER RIDGE OVER CENTRAL INDIANA WILL MOVE EAST AND WIND UP OFF THE EAST COAST BY THE END OF THE LONG TERM. AN UPPER TROUGH OVER THE WESTERN U.S. WILL ALLOW WEAK SHORTWAVES TO MOVE THROUGH THE FLOW AND BRING THUNDERSTORM CHANCES TO CENTRAL INDIANA THROUGHOUT THE LONG TERM. WITH THE SOUTHWESTERLY FLOW OVER THE AREA CONDITIONS WILL REMAIN WARM AND HUMID AS THE GULF REMAINS OPEN. NO STRONG FEATURES TO FOCUS ON SO STUCK WITH INITIALIZATION CHANCE POPS FROM SUNDAY NIGHT ON. FOR SUNDAY MORNING THE UPPER RIDGE WILL JUST BE STARTING TO MOVE EAST AND THUS THINK PRECIPITATION WILL HAVE A HARD TIME MOVING EAST INTO THE AREA UNDER UPPER SUBSIDENCE. THUS WENT DRY FOR SUNDAY MORNING AND BROUGHT IN LOW CHANCE POPS IN THE WEST IN THE AFTERNOON. && .AVIATION /DISCUSSION FOR 291200Z TAF ISSUANCE/... ISSUED AT 652 AM EDT THU MAY 29 2014 COULD HAVE AN HOUR OR SO OF MVFR FOG AT THE OUTLYING SITES. AT KLAF SHOULD SEE IFR CEILINGS STICK AROUND FOR A COUPLE HOURS BEFORE IT MIXES UP AND SCATTERS OUT. AFTER THAT WILL SEE SOME CHANCES FOR THUNDERSTORMS DURING THE AFTERNOON AND EVENING AT ALL BUT KLAF WITH THE COLD FRONT SLOWLY SINKING SOUTH THROUGH CENTRAL/SOUTHERN INDIANA. HRRR AND RAP SHOW QPF DEVELOPING ALONG/SOUTH OF I-70 STARTING AFTER 18Z OR SO AND LASTING THROUGH AROUND 1Z AND INCLUDED VCTS DURING THIS TIME. COULD SEE MVFR VISIBILITIES AND POSSIBLY CEILINGS DEVELOP AGAIN DURING THE OVERNIGHT HOURS. WINDS LESS THAN 10 KTS THROUGH THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...CP 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 INDIANAPOLIS IN
435 AM EDT THU MAY 29 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 317 AM EDT THU MAY 29 2014 SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY AS A SLOW MOVING FRONT DROPS SOUTH. THE FRONT WILL EVENTUALLY SLIP SOUTH OF THE OHIO RIVER TONIGHT AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. WARM DRY WEATHER IS ANTICIPATED INTO SUNDAY AS THE HIGH CENTERS OVER THE REGION. A MORE UNSETTLED PATTERN RETURNS FOR THE FIRST HALF OF NEXT WEEK WITH CHANCES FOR THUNDERSTORMS. && .NEAR TERM /TODAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 ANOTHER STICKY MORNING WITH PLENTY OF CLOUD DEBRIS ACROSS THE REGION. CONVECTION HAS LARGELY DIMINISHED WITH THE EXCEPTION OF A SMALL PERSISTENT CELL NEAR KMIE WHICH WAS FINALLY WEAKENING. TEMPS WERE GENERALLY IN THE 60S AS OF 07Z WITH PATCHY FOG DEVELOPING IN AREAS THAT RECEIVED RAIN ON WEDNESDAY. THE CATALYSTS FOR CONVECTIVE DEVELOPMENT WILL BE THE SAME AS THEY HAVE BEEN THE LAST FEW DAYS...MODEST INSTABILITY AND THE PRESENCE OF THE SLOWLY SOUTHWARD MOVING FRONTAL BOUNDARY. A REMNANT OUTFLOW BOUNDARY THAT APPEARS TO BE LOCATED FROM NEAR KHUF SOUTHEAST TO KBMG AND SEYMOUR IS THE WILDCARD TODAY...AS IT WILL LIKELY BE A FOCAL POINT FOR STORMS TO FIRE ONCE CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. SHORT RANGE MODEL GUIDANCE ALSO HINTING AT A WEAK AXIS OF MID LEVEL FORCING ALIGNING NORTHWEST-SOUTHEAST ACROSS THE CENTER OF THE FORECAST AREA THIS AFTERNOON BEFORE GRADUALLY SHIFTING SOUTH. WHILE THE GREATEST CONVECTIVE COVERAGE WILL BE FOUND PRIMARILY SOUTH OF I-70...THE PRESENCE OF THE WEAK FORCING ALOFT SUPPORTS SCATTERED CONVECTION ALL THE WAY NORTH TO A CRAWFORDSVILLE-NOBLESVILLE- ANDERSON LINE. HRRR AND WRF REFLECTIVITY PROGS FOR THIS AFTERNOON BOTH SUPPORT THIS IDEA IN THE 18-21Z TIME PERIOD BEFORE SHIFTING STORMS SOUTH AS DRIER AIR ATTEMPTS TO ADVECT IN FROM THE NORTHEAST. WILL CARRY CHANCE POPS FOR ALL BUT THE FAR NORTHERN COUNTIES TODAY...WITH HIGHEST POPS DURING THE AFTERNOON AND ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. LARGELY DISORGANIZED MULTICELLULAR CONVECTION ONCE AGAIN FAVORED IN THE ABSENCE OF BL SHEAR...WITH TORRENTIAL RAINFALL AND LOCALIZED FLOODING THE PRIMARY IMPACT AS STORM MOTIONS WILL BE GENERALLY 10KTS OR LESS. TEMPS...DEPENDING ON HOW QUICKLY STORMS GET GOING...POTENTIAL EXISTS FOR TEMPS TO OVERACHIEVE A BIT TODAY. WENT AT OR JUST ABOVE WARMER MAVMOS. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... ISSUED AT 317 AM EDT THU MAY 29 2014 FORECAST CHALLENGES ARE FEW THROUGH THE PERIOD...AS HIGH PRESSURE ASSERTS CONTROL OVER THE REGION FOR MUCH OF THE SHORT TERM. ANTICIPATE LINGERING CONVECTION FOCUSED OVER SOUTHERN COUNTIES NEAR THE REMNANT FRONTAL BOUNDARY THIS EVENING...WITH STORMS DIMINISHING BY MIDNIGHT AS THE AIRMASS STABILIZES AND PROGRESSIVELY DRIER AIR SPREADS IN WITH THE HIGH PRESSURE TO THE NORTH. DEEPER MOISTURE AXIS WILL REMAIN JUST TO THE SOUTHWEST OF THE FORECAST AREA ON FRIDAY...CLOSE ENOUGH THAT AN ISOLATED STORM CANNOT BE ENTIRELY RULED OUT OVER THE EXTREME SOUTHWEST FORECAST AREA. HOWEVER WITH COVERAGE SPARSE AT BEST WILL MAINTAIN A DRY FORECAST. OVER THE REMAINDER OF THE FORECAST AREA...THE SURFACE HIGH WILL TAKE ROOT WITH STRONG RIDGING ALOFT ESTABLISHING AS WELL. MODEL SOUNDINGS AND RH PROGS INDICATE DEEP SUBSIDENCE ACCOMPANYING THE HIGH WITH ABUNDANT SUNSHINE ANTICIPATED FRIDAY AND SATURDAY AS A PREDOMINANT DRY E/NE FLOW CONTINUES. ALL IN ALL...SHAPING UP TO BE A GREAT WEEKEND FOR CENTRAL INDIANA. TEMPS...DESPITE SLIGHTLY COOLER 850MB TEMPS FRIDAY AND SATURDAY... PRESENCE OF THE UPPER RIDGE AND ABUNDANT SUNSHINE WILL COMPENSATE WITH HIGHS INTO THE 80S FRIDAY AND SATURDAY. LEANED TOWARDS WARMER MAVMOS GUIDANCE BOTH DAYS. EXPECT LOWS INTO THE 50S IN SOME OF OUR NORMAL COOL SPOTS BOTH TONIGHT AND FRIDAY NIGHT...ESPECIALLY NORTH AND EAST OF THE INDY METRO. WENT ABOVE GUIDANCE AT INDY FOR LOWS TONIGHT AND FRIDAY NIGHT WITH A LIGHT E/NE FLOW. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 AN UPPER RIDGE OVER CENTRAL INDIANA WILL MOVE EAST AND WIND UP OFF THE EAST COAST BY THE END OF THE LONG TERM. AN UPPER TROUGH OVER THE WESTERN U.S. WILL ALLOW WEAK SHORTWAVES TO MOVE THROUGH THE FLOW AND BRING THUNDERSTORM CHANCES TO CENTRAL INDIANA THROUGHOUT THE LONG TERM. WITH THE SOUTHWESTERLY FLOW OVER THE AREA CONDITIONS WILL REMAIN WARM AND HUMID AS THE GULF REMAINS OPEN. NO STRONG FEATURES TO FOCUS ON SO STUCK WITH INITIALIZATION CHANCE POPS FROM SUNDAY NIGHT ON. FOR SUNDAY MORNING THE UPPER RIDGE WILL JUST BE STARTING TO MOVE EAST AND THUS THINK PRECIPITATION WILL HAVE A HARD TIME MOVING EAST INTO THE AREA UNDER UPPER SUBSIDENCE. THUS WENT DRY FOR SUNDAY MORNING AND BROUGHT IN LOW CHANCE POPS IN THE WEST IN THE AFTERNOON. && .AVIATION /DISCUSSION FOR 290900Z TAF UPDATE/... ISSUED AT 435 AM EDT THU MAY 29 2014 COULD SEE SOME MVFR FOG AT ALL THE SITES STARTING AROUND 9-10Z AND MIXING OUT BY 12-13Z. ALSO COULD SEE SOME IFR CEILINGS AND VISIBILITIES AT KLAF BASED ON SATELLITE LOOP SHOWING AREA OF LOW CEILINGS NEAR KOKOMO ADVECTING WEST AND THIS COULD LAST THROUGH MID MORNING. OTHER THAN THAT...CONDITIONS SHOULD BE MOSTLY VFR THROUGH EVENING WITH CU AND AC. SOME CHANCES FOR THUNDERSTORMS IN THE AFTERNOON BUT LOW ENOUGH PROBABILITY TO LEAVE OUT AT THIS TIME. COLD FRONT SHOULD SINK SOUTH PAST BMG AROUND OR SHORTLY AFTER 12Z. STILL...WINDS WILL BE LESS THAN 10 KNOTS THROUGH THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...MK/CP 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 INDIANAPOLIS IN
317 AM EDT THU MAY 29 2014 .UPDATE... THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 317 AM EDT THU MAY 29 2014 SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY AS A SLOW MOVING FRONT DROPS SOUTH. THE FRONT WILL EVENTUALLY SLIP SOUTH OF THE OHIO RIVER TONIGHT AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. WARM DRY WEATHER IS ANTICIPATED INTO SUNDAY AS THE HIGH CENTERS OVER THE REGION. A MORE UNSETTLED PATTERN RETURNS FOR THE FIRST HALF OF NEXT WEEK WITH CHANCES FOR THUNDERSTORMS. && .NEAR TERM /TODAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 ANOTHER STICKY MORNING WITH PLENTY OF CLOUD DEBRIS ACROSS THE REGION. CONVECTION HAS LARGELY DIMINISHED WITH THE EXCEPTION OF A SMALL PERSISTENT CELL NEAR KMIE WHICH WAS FINALLY WEAKENING. TEMPS WERE GENERALLY IN THE 60S AS OF 07Z WITH PATCHY FOG DEVELOPING IN AREAS THAT RECEIVED RAIN ON WEDNESDAY. THE CATALYSTS FOR CONVECTIVE DEVELOPMENT WILL BE THE SAME AS THEY HAVE BEEN THE LAST FEW DAYS...MODEST INSTABILITY AND THE PRESENCE OF THE SLOWLY SOUTHWARD MOVING FRONTAL BOUNDARY. A REMNANT OUTFLOW BOUNDARY THAT APPEARS TO BE LOCATED FROM NEAR KHUF SOUTHEAST TO KBMG AND SEYMOUR IS THE WILDCARD TODAY...AS IT WILL LIKELY BE A FOCAL POINT FOR STORMS TO FIRE ONCE CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. SHORT RANGE MODEL GUIDANCE ALSO HINTING AT A WEAK AXIS OF MID LEVEL FORCING ALIGNING NORTHWEST-SOUTHEAST ACROSS THE CENTER OF THE FORECAST AREA THIS AFTERNOON BEFORE GRADUALLY SHIFTING SOUTH. WHILE THE GREATEST CONVECTIVE COVERAGE WILL BE FOUND PRIMARILY SOUTH OF I-70...THE PRESENCE OF THE WEAK FORCING ALOFT SUPPORTS SCATTERED CONVECTION ALL THE WAY NORTH TO A CRAWFORDSVILLE-NOBLESVILLE- ANDERSON LINE. HRRR AND WRF REFLECTIVITY PROGS FOR THIS AFTERNOON BOTH SUPPORT THIS IDEA IN THE 18-21Z TIME PERIOD BEFORE SHIFTING STORMS SOUTH AS DRIER AIR ATTEMPTS TO ADVECT IN FROM THE NORTHEAST. WILL CARRY CHANCE POPS FOR ALL BUT THE FAR NORTHERN COUNTIES TODAY...WITH HIGHEST POPS DURING THE AFTERNOON AND ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. LARGELY DISORGANIZED MULTICELLULAR CONVECTION ONCE AGAIN FAVORED IN THE ABSENCE OF BL SHEAR...WITH TORRENTIAL RAINFALL AND LOCALIZED FLOODING THE PRIMARY IMPACT AS STORM MOTIONS WILL BE GENERALLY 10KTS OR LESS. TEMPS...DEPENDING ON HOW QUICKLY STORMS GET GOING...POTENTIAL EXISTS FOR TEMPS TO OVERACHIEVE A BIT TODAY. WENT AT OR JUST ABOVE WARMER MAVMOS. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... ISSUED AT 317 AM EDT THU MAY 29 2014 FORECAST CHALLENGES ARE FEW THROUGH THE PERIOD...AS HIGH PRESSURE ASSERTS CONTROL OVER THE REGION FOR MUCH OF THE SHORT TERM. ANTICIPATE LINGERING CONVECTION FOCUSED OVER SOUTHERN COUNTIES NEAR THE REMNANT FRONTAL BOUNDARY THIS EVENING...WITH STORMS DIMINISHING BY MIDNIGHT AS THE AIRMASS STABILIZES AND PROGRESSIVELY DRIER AIR SPREADS IN WITH THE HIGH PRESSURE TO THE NORTH. DEEPER MOISTURE AXIS WILL REMAIN JUST TO THE SOUTHWEST OF THE FORECAST AREA ON FRIDAY...CLOSE ENOUGH THAT AN ISOLATED STORM CANNOT BE ENTIRELY RULED OUT OVER THE EXTREME SOUTHWEST FORECAST AREA. HOWEVER WITH COVERAGE SPARSE AT BEST WILL MAINTAIN A DRY FORECAST. OVER THE REMAINDER OF THE FORECAST AREA...THE SURFACE HIGH WILL TAKE ROOT WITH STRONG RIDGING ALOFT ESTABLISHING AS WELL. MODEL SOUNDINGS AND RH PROGS INDICATE DEEP SUBSIDENCE ACCOMPANYING THE HIGH WITH ABUNDANT SUNSHINE ANTICIPATED FRIDAY AND SATURDAY AS A PREDOMINANT DRY E/NE FLOW CONTINUES. ALL IN ALL...SHAPING UP TO BE A GREAT WEEKEND FOR CENTRAL INDIANA. TEMPS...DESPITE SLIGHTLY COOLER 850MB TEMPS FRIDAY AND SATURDAY... PRESENCE OF THE UPPER RIDGE AND ABUNDANT SUNSHINE WILL COMPENSATE WITH HIGHS INTO THE 80S FRIDAY AND SATURDAY. LEANED TOWARDS WARMER MAVMOS GUIDANCE BOTH DAYS. EXPECT LOWS INTO THE 50S IN SOME OF OUR NORMAL COOL SPOTS BOTH TONIGHT AND FRIDAY NIGHT...ESPECIALLY NORTH AND EAST OF THE INDY METRO. WENT ABOVE GUIDANCE AT INDY FOR LOWS TONIGHT AND FRIDAY NIGHT WITH A LIGHT E/NE FLOW. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... ISSUED AT 317 AM EDT THU MAY 29 2014 AN UPPER RIDGE OVER CENTRAL INDIANA WILL MOVE EAST AND WIND UP OFF THE EAST COAST BY THE END OF THE LONG TERM. AN UPPER TROUGH OVER THE WESTERN U.S. WILL ALLOW WEAK SHORTWAVES TO MOVE THROUGH THE FLOW AND BRING THUNDERSTORM CHANCES TO CENTRAL INDIANA THROUGHOUT THE LONG TERM. WITH THE SOUTHWESTERLY FLOW OVER THE AREA CONDITIONS WILL REMAIN WARM AND HUMID AS THE GULF REMAINS OPEN. NO STRONG FEATURES TO FOCUS ON SO STUCK WITH INITIALIZATION CHANCE POPS FROM SUNDAY NIGHT ON. FOR SUNDAY MORNING THE UPPER RIDGE WILL JUST BE STARTING TO MOVE EAST AND THUS THINK PRECIPITATION WILL HAVE A HARD TIME MOVING EAST INTO THE AREA UNDER UPPER SUBSIDENCE. THUS WENT DRY FOR SUNDAY MORNING AND BROUGHT IN LOW CHANCE POPS IN THE WEST IN THE AFTERNOON. && .AVIATION /DISCUSSION FOR 290600Z TAF ISSUANCE/... ISSUED AT 1253 AM EDT THU MAY 29 2014 WOULD NOT RULE OUT A STRAY THUNDERSTORM OVERNIGHT...BUT CHANCES ARE LOW ENOUGH THAT WILL NOT PUT IN ANY OF THE TAFS. COULD SEE SOME MVFR FOG AFTER 09Z...OTHER THAN THAT...CONDITIONS SHOULD BE MOSTLY VFR THROUGH TOMORROW EVENING WITH CU AND AC. COLD FRONT SHOULD BE NEAR OR SOUTH OF HUF AND IND AT ISSUANCE TIME AND BMG LIKELY AROUND OR SHORTLY AFTER 12Z. STILL...WINDS WILL BE LESS THAN 10 KNOTS THROUGH THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...MK/CP 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 NORTHERN INDIANA
200 AM EDT THU MAY 29 2014 .SYNOPSIS... ISSUED AT 155 AM EDT THU MAY 29 2014 A RIDGE OF HIGH PRESSURE WILL SLOWLY SAG INTO THE REGION TODAY PROVIDING MAINLY DRY CONDITIONS. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE ONCE AGAIN FROM CENTRAL ILLINOIS INTO CENTRAL INDIANA. THIS RIDGE OF HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THROUGH MOST OF THE UPCOMING WEEKEND. HIGH TEMPERATURES ON THURSDAY WILL RANGE FROM THE MID 70S TO AROUND 80. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE LOWER AND MID 50S. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 336 PM EDT WED MAY 28 2014 LOOSELY DEFINED "COLD" FRONT...MORE ACCURATELY DESCRIBED AS A WEAK SURFACE PRESSURE TROUGH WITH A MODEST MOISTURE/DENSITY GRADIENT...CONTINUES TO SLOWLY PUSH SOUTH ACROSS THE AREA AT PRESS TIME. AS PREVIOUSLY NOTED...VERY LITTLE SYNOPTIC SUPPORT ALONG THIS FRONT WITH JUST A VERY WEAK VORTICITY LOBE WINDING DOWN ACROSS THE REGION. SHOWERS AND THUNDERSTORMS BEING DRIVEN BY SUBTLE CONVERGENCE ALONG OLD OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES IN A MOIST AND MARGINALLY UNSTABLE AIRMASS. EARLY DAY INSOLATION ALLOWED FOR A DECENT RISE IN MLCAPE VALUES ACROSS OUR SOUTHERN COUNTIES WHILE FAR NORTHERN ZONES REMAIN LARGELY CAPPED AND STABLE. NUMEROUS SHOWERS AND THUNDERSTORMS HAVE THEREFORE DEVELOPED IN OUR SOUTHERN CWA AS EXPECTED. LACK OF APPRECIABLE SHEAR AND/OR CLEAR FORCING MECHANISM WILL CONTINUE TO SUPPORT PULSE/MULTICELLULAR MODE THROUGH THE EVENING. AN ISOLATED WET MICROBURST MAY BE POSSIBLE ONCE AGAIN BUT THREAT FOR MORE WIDESPREAD SEVERE WEATHER IS VERY LOW. HEAVY RAIN IS STILL THE MAIN THREAT WITH HIGH PW VALUES...WEAK FLOW PARALLEL TO THE FRONT...AND MORE EFFICIENT WARM RAIN PROCESSES. HRRR AND OTHER HI-RES GUIDANCE HAVE HAD A VERY GOOD HANDLE ON CONVECTION SO FAR TODAY AND SUGGEST THUNDERSTORMS WILL DISSIPATE AND DRIFT SOUTH BY AROUND 03Z WITH THE LOSS OF DAYTIME HEATING AND GRADUAL SOUTHWARD PUSH OF FRONT. DRY CONDITIONS THEN EXPECTED FOR THE REST OF THE PERIOD AS HIGH AMPLITUDE RIDGE FOLDS INTO THE GREAT LAKES AND SUPPORTS SURFACE HIGH PRESSURE. A STRAY SHOWER MAY BE POSSIBLE TOMORROW MORNING IN OUR FAR SOUTHERN COUNTIES BUT CHANCES ARE VERY LOW. THERMAL PROFILES BEHIND THIS FRONT ARE NOT VERY DIFFERENT FROM CURRENT VALUES AND EXPECT INCREASING SUN TO SUPPORT ANOTHER DAY OF HIGHS NEAR 80F. DEWPOINTS WILL BE TOUCH LOWER THOUGH...TAKING THE HUMIDITY DOWN A NOTCH. && .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 336 PM EDT WED MAY 28 2014 LONG WAVE PATTERN WITH HIGHLY AMPLIFIED RIDGE OVER THE CENTRAL US WILL START THE LONG TERM PERIOD. TROF ALONG THE NOAM WEST COAST EJECTS EASTWARD AND WHILE MODELS DIFFER ON THE TIMING AND EVOLUTION THERE IS ENOUGH CONSENSUS TO SUPPORT A FLATTENING OF THE RIDGE OVER THE GREAT LAKES REGION TOWARD THE END OF THE LONG TERM PERIOD. THE CHALLENGE IS THE SIGNIFICANT DIFFERENCE BETWEEN THE 06Z AND 12Z GFS RUN. 12Z MODEL IS MORE CLOSELY ALIGNED WITH THE GEM/ECMWF AND UKMET - THE 06Z AS THE OUTLIER HAD THE LOW EJECTING FROM THE PLAINS IN WHAT APPEARS TO BE MUCH TO FAST AND TOO FAR SOUTH. REGARDLESS WITH ABUNDANT LOW LEVEL MOISTURE AND THE AREA WITHIN THE WARM SECTOR...EXPECT TO SEE CONVECTION DEVELOP AS CURRENTLY FORECAST AND SHOULD NOT CAUSE A DRAMATIC CHANGE TO CURRENT GRIDDED FORECAST. AS THE RIDGE FLATTENS AND WESTERLY FLOW INCREASES WOULD EXPECT TO SEE THE FRONTAL BOUNDARY PUSH SOUTH OF THE AREA DURING THE LATTER PART OF THE EXTENDED PERIOD...WITH SLIGHT COOLING. TEMPERATURES SHOULD STILL REMAIN ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 155 AM EDT THU MAY 29 2014 PATCHY STRATUS IS EXPECTED TO CONTINUE OVERNIGHT WITH LINGERING LOW LEVEL MOISTURE AND FAIRLY WEAK GRADIENT IN PLACE. MVFR CONDITIONS ARE CURRENTLY BEING REPORTED AT TERMINALS...AND MAY SEE SOME BUILD DOWN OF THIS STRATUS OVERNIGHT. THUS...WILL MAINTAIN TREND TO IFR CIGS OVERNIGHT FROM PREVIOUS FORECAST. ANY LINGERING IFR OR MVFR CONDITIONS WILL IMPROVE TO VFR BY MID MORNING THURSDAY. DRY AIR ADVECTION ASSOCIATED WITH SFC TROUGH WILL KEEP FOCUS FOR ISOLD/SCT AFTERNOON SHOWERS SOUTH OF THE TERMINALS. NORTHEAST WINDS TO CONTINUE THROUGH THIS PERIOD WITH SPEEDS GENERALLY AT OR BELOW 10 KNOTS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...MARSILI SHORT TERM...AGD LONG TERM...LEWIS AVIATION...MARSILI VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1253 AM EDT THU MAY 29 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 328 PM EDT WED MAY 28 2014 A WEAK COLD FRONT WILL MOVE THROUGH CENTRAL INDIANA TONIGHT AND THURSDAY BRINGING SOME SHOWERS AND THUNDERSTORMS WITH IT. FRIDAY AND SATURDAY WILL BE DRY WITH HIGH PRESSURE IN CONTROL...BUT CHANCES FOR RAIN RETURN FOR LATE SUNDAY INTO NEXT WEEK AS ANOTHER SYSTEM BEGINS TO INFLUENCE THE AREA. TEMPERATURES WILL REMAIN WARM THROUGH THE PERIOD. && .NEAR TERM /OVERNIGHT/... ISSUED AT 923 PM EDT WED MAY 28 2014 SURFACE ANALYSIS EARLY THIS EVENING SHOWS A SLOWING FRONTAL BOUNDARY NEAR INTERSTATE 70. RAIN COOLED AIR NORTH OF THE FRONT HAS RESULTED IN COOLER TEMPS...LOWER DEW POINTS AND MORE STABLE AIR. SOUTH OF THE FRONT...THE AIR MASS REMAINED UNSTABLE AND SCT SHRA/TSRA WERE DEVELOPING. HOWEVER...WITH HEATING WANING...ANY SHOWERS OR STORMS THAT DEVELOP ARE EXPECTED TO WEAKEN QUICKLY DURING THE NEXT SEVERAL HOURS. HRRR AGREES. AS FOR TEMPS HAVE TRENDED LOWS A BIT COOLER IN THE RAIN COOLED AIR MASS TO THE NORTH...AND STUCK WARMER AHEAD OF THE FRONT TO THE SOUTH. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... ISSUED AT 328 PM EDT WED MAY 28 2014 FOCUS IS ON CHANCES FOR RAIN EARLY IN THE PERIOD. MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED. WITH FRONT IN THE AREA ON THURSDAY CONTINUED CHANCE POPS MOST AREAS...HIGHEST IN THE SOUTH CLOSEST TO THE FRONT. DO NOT SEE ENOUGH FORCING FOR LIKELY OR HIGHER POPS WITH NO UPPER SUPPORT. TIMING OF BEST CHANCES WILL BE LATE MORNING INTO AFTERNOON AS INSTABILITY BUILDS. AS FRONT CONTINUES ITS SLOW JOURNEY SOUTH KEPT LINGERING SLIGHT CHANCE TO LOW CHANCE POPS IN THE SOUTHWEST FORECAST AREA THURSDAY EVENING. FRONT SHOULD BE FAR ENOUGH SOUTH AND INSTABILITY LOW ENOUGH OVERNIGHT THURSDAY FOR DRY POPS. ON FRIDAY AND SATURDAY UPPER HIGH WILL BUILD IN AND PROVIDE DRY CONDITIONS. GENERALLY TRENDED TOWARD THE MAV MOS THROUGH THE PERIOD AS MET LOOKS A BIT COOL WITH NO GOOD SHOT OF COOLER AIR MOVING IN. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... ISSUED AT 213 PM EDT WED MAY 28 2014 HIGH PRESSURE OVER THE EASTERN U.S. AND AN UPPER RIDGE OF HIGH PRESSURE MOVING EAST OF OUR AREA WHILE UPPER TROUGHING DEVELOPS OVER THE WESTERN STATES SPELLS WARM TEMPERATURES AND RETURN OF GULF MOISTURE AND HIGHER HUMIDITY BY SUNDAY NIGHT. MINOR SHORT WAVES MOVING THROUGH THE FLOW MEAN TIMING ISSUES FOR PRECIPITATION AND HARD TO PINPOINT MOST LIKELY WINDOWS OF OPPORTUNITY FOR RAIN. HAVE THUS CARRIED CHANCE POPS FOR NEARLY ALL PERIODS STARTING SUNDAY WHICH ACTUALLY TIES TO ALL MODEL SOLUTIONS OF SOME PRECIPITATION POSSIBLE DAY OR NIGHT INTO MIDWEEK. AS FOR TEMPERATURES...WITH ABOVE NORMAL HEIGHTS AND INCREASING DEWPOINTS STARTING SUNDAY EXPECT MAXS AND MINS TO BE ABOVE NORMAL FOR THIS TIME OF YEAR. NO SIGNIFICANT ADJUSTMENTS TO CURRENT FORECAST TEMPS WERE MADE...USING A MIX OF MOS DATA AND BLENDED SETS. && .AVIATION /DISCUSSION FOR 290600Z TAF ISSUANCE/... ISSUED AT 1253 AM EDT THU MAY 29 2014 WOULD NOT RULE OUT A STRAY THUNDERSTORM OVERNIGHT...BUT CHANCES ARE LOW ENOUGH THAT WILL NOT PUT IN ANY OF THE TAFS. COULD SEE SOME MVFR FOG AFTER 09Z...OTHER THAN THAT...CONDITIONS SHOULD BE MOSTLY VFR THROUGH TOMORROW EVENING WITH CU AND AC. COLD FRONT SHOULD BE NEAR OR SOUTH OF HUF AND IND AT ISSUANCE TIME AND BMG LIKELY AROUND OR SHORTLY AFTER 12Z. STILL...WINDS WILL BE LESS THAN 10 KNOTS THROUGH THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...PUMA SHORT TERM...50 LONG TERM....TUCEK AVIATION...MK/CP 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 QUAD CITIES IA IL
648 PM CDT FRI MAY 30 2014 .SYNOPSIS... ISSUED AT 336 PM CDT FRI MAY 30 2014 12Z UA ANALYSIS HAS THE CLOSED UPPER LOW OVER THE LOWER MISSISSIPPI VALLEY WITH HIGH PRESSURE OVER THE GREAT LAKES. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOW PLENTY OF DIURNAL CLOUDS WITH CONVECTION FROM SOUTHERN ILLINOIS THROUGH NORTHEAST MISSOURI AND INTO PARTS OF SOUTHERN IOWA. 18Z SFC ANALYSIS HAD HIGH PRESSURE FROM THE GREAT LAKES INTO THE SOUTHERN PLAINS WITH SOME INFERRED WEAK BOUNDARIES OVER THE LOWER MISSISSIPPI AND OHIO VALLEYS. DEW POINTS WERE MAINLY IN THE 60S ACROSS THE MIDWEST AND PLAINS WITH 50S ACROSS THE GREAT LAKES. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 336 PM CDT FRI MAY 30 2014 BASED ON SATELLITE...RADAR...AND RAP TRENDS...THE CONVECTION FROM SOUTHERN ILLINOIS INTO NORTHEAST MISSOURI AND SOUTHERN IOWA WILL NOT MAKE MUCH MORE NORTHERN PROGRESS THROUGH LATE AFTERNOON. THUS AREAS SOUTH OF A KOTM TO KSPI LINE WILL HAVE THE BEST CHANCE OF SEEING ISOLATED TO POSSIBLY SCATTERED STORMS. AFTER SUNSET...THE REMAINING CONVECTION WILL DISSIPATE BY 10-11 PM ALONG WITH THE REMAINING DIURNAL CLOUDS. THE REMAINDER OF THE NIGHT WILL BE QUIET AND DRY. QUIET AND DRY CONDITIONS WILL BE SEEN INITIALLY SATURDAY MORNING ACROSS THE AREA. NEW DIURNAL CLOUDS WILL BEGIN DEVELOPING BY LATE MORNING WITH SOME CONVECTION ACROSS THE FAR WEST BY MID DAY. CONVECTION WILL INCREASE IN AREAL COVERAGE SATURDAY AFTERNOON ACROSS THE WESTERN HALF OF THE AREA AS BETTER MOISTURE MOVES INTO THE AREA. EAST OF THE MISSISSIPPI DRY CONDITIONS ARE EXPECTED SATURDAY AFTERNOON. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 336 PM CDT FRI MAY 30 2014 CONVECTION THAT DEVELOPS ACROSS THE WESTERN HALF OF THE AREA WILL SLOWLY DISSIPATE SATURDAY EVENING WITH SUNSET. MAINLY DRY CONDITIONS ARE EXPECTED FROM LATE SATURDAY NIGHT THROUGH SUNRISE SUNDAY. INCREASING MOISTURE RETURN ON SUNDAY WITH A WEAK DISTURBANCE ALOFT WILL ALLOW NEW CONVECTION TO DEVELOP BY LATE MORNING AND INCREASE IN AREAL COVERAGE DURING THE AFTERNOON HOURS. THIS CONVECTION IS EXPECTED TO CONTINUE INTO SUNDAY EVENING BEFORE DISSIPATING. SUNDAY NIGHT AND INTO MONDAY THE MODELS ARE SUGGESTING AN ORGANIZED THUNDERSTORM COMPLEX DEVELOPING IN EASTERN NEBRASKA AND MOVING EAST. IF CORRECT...THIS THUNDERSTORM COMPLEX WOULD ARRIVE IN THE AREA VERY LATE SUNDAY NIGHT AND MOVE ACROSS THE AREA MONDAY MORNING AS IT DISSIPATES. BOUNDARIES LEFT OVER FROM THIS COMPLEX WOULD THEN PROVIDE THE FOCUS FOR NEW CONVECTION DEVELOPING MONDAY AFTERNOON. MONDAY NIGHT ON... THERE ARE DIFFERENCES AMONG THE MODELS AS TO WHAT WILL OCCUR MONDAY NIGHT THROUGH TUESDAY. THE ECMWF/GEM SUGGEST HIGH PRESSURE BUILDING IN BRINGING AN END TO THE RAIN. THE GFS KEEPS RAIN ACROSS THE AREA. WEIGHING THE STRENGTHS/WEAKNESSES OF THE MODELS AND CONSIDERING THE OVERALL SYNOPTIC PICTURE...THE IDEA OF BRINGING IN A DRYING TREND LATE MONDAY NIGHT AND TUESDAY DOES HAVE MERIT. TUESDAY NIGHT THROUGH FRIDAY...THE MODEL CONSENSUS HAS CHANCE POPS EACH DAY. THE OVERALL SYNOPTIC PICTURE SUGGESTS A POTENTIALLY ACTIVE PATTERN WITH AN EAST/WEST BOUNDARY SETTING UP IN OR CLOSE TO THE AREA. WILL IT RAIN CONTINUOUSLY THE ENTIRE TIME. NO. EACH ROUND OF CONVECTION WILL DICTATE WHERE SUBSEQUENT ROUNDS OF CONVECTION WILL DEVELOP. SO...THERE WILL BE PERIODS OF DRY WEATHER FROM TUESDAY NIGHT THROUGH FRIDAY. ATTEMPTING TO PIN THEM DOWN IS NOT POSSIBLE WHEN DEALING WITH NONLINEAR PROCESSES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 641 PM CDT FRI MAY 30 2014 EASTERLY WINDS OFF HIGH PRESSURE OVER THE GREAT LAKES WILL KEEP FEEDING DRY AIR INTO NORTHWEST IL AND NEARBY AREAS OF NORTHEAST AND EAST CENTRAL IOWA. THESE AREAS SHOULD CONTINUE TO SEE VFR CONDITIONS THROUGH SATURDAY AFTERNOON. HIGHER LOW LEVEL MOISTURE WILL FOUND FROM WEST CENTRAL IL NORTHEAST INTO CENTRAL AND ADJACENT AREAS OF EAST CENTRAL AND SOUTHEAST IOWA THROUGH SATURDAY. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ONGOING IN THIS AREA EARLY THIS EVENING WILL DISSIPATE BY MID EVENING. THE SHOWERS AND STORMS SHOULD REDEVELOP OVER THE SAME AREAS AGAIN LATE SATURDAY AFTERNOON. OUTSIDE OF ANY SHOWERS AND STORMS FLIGHT CONDITIONS WILL BE VFR. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...08 SHORT TERM...08 LONG TERM...08 AVIATION...DLF
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1253 PM CDT THU MAY 29 2014 .UPDATE... ISSUED AT 1248 PM CDT THU MAY 29 2014 NEW CONVECTION HAS DEVELOPED FROM NORTHERN MISSOURI INTO CENTRAL ILLINOIS. BASED ON SUGGESTED DATA AND RAP TRENDS...NEW DIURNAL CONVECTION SHOULD BEGIN DEVELOPING AND INCREASING ACROSS THE SOUTH THIRD THIS AFTERNOON. IF THE GEM TRENDS ARE CORRECT... CONVECTION MAY APPROACH I-80 BY LATE AFTERNOON. UPDATE ISSUED AT 1117 AM CDT THU MAY 29 2014 THE LOW STRATUS THAT ADVECTED IN FROM INDIANA ACROSS THE NORTHEAST AREAS HAS DISSIPATED AS ARE THE ISOLATED SHOWERS OVER THE FAR SOUTHWEST. SATELLITE TRENDS SHOW NEW CONVECTIVE CLOUDS HAVE DEVELOPED IN THE PAST HOUR FROM NORTHERN MISSOURI INTO CENTRAL ILLINOIS. BASED ON CLOUD RATE GROWTH...NEW DIURNAL CONVECTION WILL BE DEVELOPING IN ERNEST OVER THE NEXT 90 MINUTES. && .SYNOPSIS... ISSUED AT 310 AM CDT THU MAY 29 2014 THE BACK DOOR COOL FRONT HAS MADE ITS WAY THROUGH MUCH OF THE CWA BY 2 AM THIS MORNING. MODELS ARE NOT EVEN REMOTELY CLOSE IN HANDLING THIS. THE MAIN IMPACT BETWEEN FORECAST MODELS AND OBSERVED DATA IS THAT ACTUAL DEWPOINTS ARE FALLING FASTER AS THIS AIRMASS IS QUITE DRY...AT LEAST AT SHALLOW LEVELS. DEWPOINTS IN THE MID 40S TO LOWER 50S ARE SPREADING WEST INTO THE CWA...AND SHOULD ESTABLISH AT LEAST WIDESPREAD 50S BY SUNRISE IN ALL LOCATIONS. TEMPERATURES ARE ALSO FALLING...INTO THE MID 50S NORTHEAST ALREADY. THE SOUTHWEST...STILL NEAR THE FRONT...REMAINS MILD AND MOIST BUT WILL EVENTUALLY FALL BY SUNRISE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 310 AM CDT THU MAY 29 2014 THE MODEL MOISTURE PROBLEM WILL CERTAINLY IMPACT TODAYS FORECAST. I WILL KEEP OUR SHARP GRADIENT BETWEEN SLIGHT/CHC POPS IN THE FAR SOUTH TO AROUND ZERO NORTH OF INTERSTATE 80 GOING TODAY AS DIURNAL DRIVEN CONVECTION REMAINS POSSIBLE NEAR THE BOUNDARY. HOWEVER...I AM FARTHER SOUTH THAN MODELS DUE TO THE DRY AIR INTRUSION BEING MORE AGGRESSIVE THAN MODELS HAVE. AGAIN...THIS SEEMS TO BE ONLY A SHALLOW FEATURE...AS WE CONTINUE TO HAVE PLENTY OF PATCHY MID CLOUDS AROUND POST FRONTAL. THUS...THE POPS WILL REMAIN IN THE SOUTH VS TOTALLY REMOVING THEM. TEMPERATURES TODAY SHOULD REBOUND NICELY...TO THE UPPER 70S NORTHEAST TO LOWER 80S SOUTHWEST. WITH DRY AIR IN PLACE IN AT LOW LEVELS...AND CROPS NOT YET LARGE IN SIZE...WE SHOULD ONLY REBOUND DEWPOINTS TO AROUND 57 TO 60 EXCEPT IN THE FAR SOUTH WERE SOME MID 60S ARE POSSIBLE. THIS WILL MAKE FOR A VERY PLEASANT LATE SPRING DAY FOR MOST OF THE CWA. TONIGHT...WITH LIGHT EAST FLOW CONTINUING...IT WILL BE ANOTHER GOOD NIGHT TO LEAVE THE WINDOWS OPEN. LOWS WILL ONCE AGAIN FALL TO THE LOWER 50S TO LOWER 60S FROM EAST TO WEST. WE WILL MISS THIS WEATHER ONCE THE TRUE HEAT OF SUMMER ARRIVES. ERVIN .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 310 AM CDT THU MAY 29 2014 HIGHER HUMIDITY AND RAIN CHANCES CREEP BACK INTO THE FORECAST SATURDAY ONWARD AS THE SURFACE HIGH OVER THE GREAT LAKES EDGES EAST AND THE UPPER RIDGE GIVES WAY TO A MORE ACTIVE...NEARLY ZONAL FLOW THAT WILL PERSIST THROUGH AT LEAST THE MIDDLE PART OF NEXT WEEK. FRIDAY...HIGH PRESSURE CENTERED OVER LOWER MI WILL CONTINUE TO CHANNEL A DRY EASTERLY FLOW MAINTAINING LOW DEWPOINTS...ESPECIALLY OVER NORTHEAST HALF OF THE FORECAST AREA. SIMILAR TO THIS MORNING...SUSPECT MODELS ARE OVERDONE WITH FORECAST DEWPOINTS IN THE 60S AND EVEN LOWER 70S OVER THE SOUTH...WHEN WIDESPREAD 50S AND POSSIBLY A FEW UPPER 40S WILL BE MORE LIKELY IN THIS AIRMASS. LARGELY BASED ON THESE SUSPICIOUS HIGHER DEWPOINTS AND ASSOCIATED HIGHER CAPES...MODELS BREAKOUT CONVECTION OVER NORTHEAST MO...SE IA AND W CENTRAL IL DURING THE DAY. CONSIDERING THIS BIAS ALONG WITH THE LACK OF FOCUSING BOUNDARIES AND SUPPRESSION FROM THE UPPER RIDGE OVERHEAD...WILL CONTINUE TO UNDERCUT GUIDANCE POPS AND PROVIDE ONLY SLIGHT TO LOW END CHANCES FOR THUNDERSTORMS OVER THE FAR SOUTH AND SOUTHWEST IN THE AFTERNOON. OTHERWISE...IT SHOULD BE A MOSTLY SUNNY DAY WITH HIGHS REACHING AROUND 80 TO THE LOWER 80S. THE DRY AIRMASS WILL REMAIN IN PLACE OVERNIGHT...WITH LIGHT WINDS ALLOWING TEMPERATURES TO COOL TO A RANGE FROM THE MID 50S EAST AND NORTH TO THE LOWER 60S SOUTH AND WEST. SATURDAY...THE UPPER RIDGE AXIS SHIFTS TO THE EAST WITH MORE SOUTHERLY SURFACE WINDS BEGINNING TO RETURN HIGHER LOW LEVEL MOISTURE INTO THE AREA DURING THE DAY. THE INCREASING MOISTURE AND TRIGGER FROM A WEAK UPPER LEVEL IMPULSE MAY BE SUFFICIENT TO PRODUCE THUNDERSTORMS OVER THE WEST AND HAVE LOW CHANCE POPS FOR THE AFTERNOON. FORECAST THERMAL FIELDS INDICATE HIGHS AGAIN REACHING THE LOWER TO POSSIBLY MID 80S. SUNDAY ONWARD...THE UPPER RIDGE TO THE EAST FLATTENS GIVING WAY TO AN ACTIVE WAVE-TRAIN OF UPPER LEVEL SHORTWAVES THROUGH THE REGION FOR MUCH OF NEXT WEEK. THIS LEADS TO AN EXTENDED PERIOD OF RAIN AND THUNDERSTORM CHANCES AS RETURNING GULF MOISTURE INTERACTS WITH A FRONTAL BOUNDARY. THE MOST NOTABLE CHANGE IN THE 00Z MODEL RUN WAS THE NOW OUTLIER ECMWF WITH ITS STRONGER SURFACE LOW AND CLOSED UPPER LOW ROLLING BY TO THE NORTH MONDAY AND TUESDAY IN CONTRAST TO THE MORE CONSISTENT GFS...AND TO SOME EXTENT UKMET AND GEM THAT HAVE A MUCH WEAKER INITIAL LOW/SHORTWAVE AND THEN A LINGERING FRONT OVER THE AREA THROUGH WED. EITHER SCENARIO POINTS TOWARD HIGHER CONSENSUS POPS ON MONDAY ACROSS THE NORTH...WHERE WE HAVE GONE WITH LIKELY POPS. HIGH END CHANCE POPS ARE THEN CARRIED THROUGH MID WEEK LARGELY BASED ON THE NON-ECMWF SOLUTIONS. THIS SETUP WOULD BE FAVORABLE FOR A THREAT OF HEAVY RAINFALL AND POSSIBLE SEVERE STORMS FROM MONDAY NIGHT THROUGH WED. HIGHS ARE ADVERTISED IN THE 80S FOR MONDAY...THEN UPPER 70S TO LOWER 80S TUE AND WED...WHERE CONFIDENCE IN TEMPERATURES IS LOWER DUE TO UNCERTAINTIES IN THE CRITICAL LOCATION OF THE BOUNDARY. HIGH DEWPOINTS WILL HOLD MINS IN THE 60S TO AROUND 70 THROUGHOUT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1248 PM CDT THU MAY 29 2014 MAINLY VFR CONDITIONS WILL BE SEEN THROUGH 06Z/30 EXCEPT AROUND SHRA/TSRA THAT MAY BRIEFLY CREATE MVFR/IFR CONDITIONS. KBRL HAS THE BEST CHANCE OF BEING IMPACTED BY A SHRA/TSRA. AFT 06Z/30 MAINLY VFR CONDITIONS ARE EXPECTED BUT THE POTENTIAL DOES EXIST FOR MVFR VSBYS/CLOUDS TO DEVELOP. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...SHEETS AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1149 PM CDT WED MAY 28 2014 .SYNOPSIS... ISSUED AT 310 PM CDT WED MAY 28 2014 12Z UA ANALYSIS HAS A WEAK UPPER LOW IN NORTHEAST IOWA WITH A STRONGER UPPER LOW IN SOUTHWEST ARKANSAS. SEVERAL WEAK DISTURBANCES WERE ROTATING AROUND THE LOWS. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOW DIURNAL CONVECTION ACROSS EASTERN IOWA AND NORTHERN ILLINOIS THAT WAS SLOWLY ROTATING AROUND THE UPPER LOW IN EASTERN IOWA. 18Z SFC ANALYSIS HAS AS WEAK LOW NEAR KAWG WITH A BOUNDARY EASTWARD THROUGH CENTRAL ILLINOIS. DEW POINTS WERE IN THE 60S FROM THE GULF COAST INTO THE MID MISSISSIPPI AND OHIO VALLEYS. DEW POINTS IN THE 40S AND 50S WERE ACROSS THE GREAT LAKES. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 310 PM CDT WED MAY 28 2014 RECENT RAP TRENDS INDICATE THE EFFECTIVE BOUNDARY WILL REMAIN NEARLY STATIONARY FROM ABOUT KAWG TO NEAR KPNT THROUGH LATE AFTERNOON. WITH THE WEAK UPPER LOW JUST WEST OF THE QUAD CITIES...CONVECTION WILL DRIFT SLOWLY SOUTH WEST OF THE MISSISSIPPI AND SLOWLY NORTH EAST OF THE MISSISSIPPI. DUE TO THE SLOW MOVEMENT OF STORMS...LOCALLY HEAVY RAINFALL WILL BE SEEN. BY EARLY EVENING AND CONTINUING THROUGH SUNSET CONVECTION WILL SLOWLY DISSIPATE WITH CONVECTION BECOMING VERY ISOLATED BY MIDNIGHT. DURING THE EVENING THE BOUNDARY WILL SLOWLY DRIFT SOUTH AND WILL BE THE FOCUS FOR MAINTAINING ISOLATED CONVECTION PAST SUNSET. AFTER MIDNIGHT MOST OF THE AREA IS EXPECTED TO REMAIN DRY AS THE BOUNDARY CONTINUES A SLOW DRIFT TO THE SOUTH. ANY REMAINING RAIN WILL BE CONFINED TO AREAS CLOSE TO THE FRONT. THURSDAY MORNING THERE MAY BE SOME LINGERING SHOWERS ACROSS THE FAR SOUTH CLOSE TO THE BOUNDARY WHILE THE REMAINDER OF THE AREA IS DRY. NEW DIURNAL CONVECTION IS EXPECTED TO DEVELOP BY LATE MORNING AND CONTINUE THROUGH THURSDAY AFTERNOON SOUTH OF I-80. THIS NEW CONVECTION IS EXPECTED TO BE ISOLATED IN NATURE BUT MAY BE MORE SCATTERED BETWEEN KBRL AND KUIN. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 310 PM CDT WED MAY 28 2014 SURFACE AND UPPER RIDGING WILL MOVE THROUGH THE REGION LATE THIS WEEK KEEPING DRY WEATHER OVER THE AREA. THUNDERSTORM CHANCES WILL RETURN TO THE FORECAST OVER THE WEEKEND AND EARLY NEXT WEEK AS LOW LEVEL MOISTURE INCREASES BEHIND THE DEPARTING RIDGE. THE BEST CHANCE OF THUNDERSTORMS WILL BE TUESDAY INTO WEDNESDAY AS A COLD FRONT MOVES SLOWLY THROUGH THE REGION. THURSDAY NIGHT INTO FRIDAY NIGHT LESS HUMID CONDITIONS WILL BE IN PLACE WITH A SURFACE HIGH OVER THE WESTERN GREAT LAKES FEEDING DRY AIR INTO THE REGION. TEMPERATURES SHOULD BE SEASONAL WITH HIGHS FRIDAY IN THE LOW 80S AND LOWS THURSDAY AND FRIDAY MORNINGS IN THE MID 50S TO MID 60S. THUNDERSTORM CHANCES CREEP BACK INTO THE FORECAST FOR THE WEEKEND AS THE UPPER AND SURFACE RIDING MOVE EAST ALLOWING MOIST RETURN FLOW TO SET UP. FOR NOW WITHOUT ANY OBVIOUS FORCING MECHANISMS SHOWN IN THE MODEL SOLUTIONS KEPT POPS IN THE LOW CHANCE CATEGORY. MODEL SOLUTIONS SHOW A BETTER THREAT OF THUNDERSTORMS EARLY NEXT WEEK WITH A PERSISTENT SOUTHWEST TROF IN PLACE AND A SERIES OF S/WS EJECTING OUT OF THE TROF INTO THE PLAINS AND UPPER MIDWEST. THIS WILL SEND A SLOW MOVING COLD FRONT THROUGH THE REGION TUESDAY INTO WEDNESDAY. THE GFS/ECMWF GENERALLY AGREE ON THE OVER ALL SYNOPTIC PATTERN EARLY NEXT WEEK BUT HAVE DIFFERENT TAKES ON HANDLING THE S/WS IN THE SOUTHWEST FLOW AND THE SURFACE FRONT. THE GFS BRINGS OUT A MAIN S/W MONDAY NIGHT AND TUESDAY WHICH PUSHES THE COLD FRONT SOUTHEAST OF THE FORECAST AREA BY WEDNESDAY. THE ECMWF IS MORE FRAGMENTED WITH THE S/WS AND STALLS THE FRONT OVER OR JUST SOUTH OF THE CWA BY LATE TUESDAY. EITHER SOLUTION THOUGH SUPPORTS AN ACTIVE PATTERN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1140 PM CDT WED MAY 28 2014 DRIER AIR ON NORTHEAST WINDS AROUND 10 KTS SHOULD LIMIT FOG TO VERY PATCHY (2-6SM) NATURE AND MAINLY ACROSS THE FAR SOUTHERN CWA WITHIN BETTER LOW LEVEL MOISTURE OR IN AREAS THAT RECEIVED RAIN WED PM. OTHERWISE...VFR CONDITIONS EXPECTED THROUGH THE TAF CYCLE. A FEW SHOWERS AND STORMS EXPECTED TO DEVELOP YET AGAIN THURSDAY PM BUT MAINLY WELL SOUTH OF I-80 WITHIN RESIDUAL MOIST AXIS AND ATTENDANT TO UPPER DISTURBANCE...WITH ANY ACTIVITY DISSIPATING TOWARD SUNSET. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...08 SHORT TERM...08 LONG TERM...DLF AVIATION...05
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1206 PM CDT THU MAY 29 2014 .AVIATION... UPPER LOW OVER SOUTHCENTRAL AR...TO RETROGRADE SLOWLY SWWD THRU PERIOD. MOISTURE WRAPPING AROUND NORTH SIDE OF LOW WILL LIKELY AFFECT SW AR TERMINALS OF KTXK AND KELD...AND KMLU...BY MID AFTN...WITH SCATTERED TO NUMEROUS CONVECTIVE COVERAGE. CONVECTION MAY HOLD OFF CLOSER TO 30/00Z AT REMAINING TERMINAL SITES...AS UPPER LOW BEGINS TO MOVE OVHD. THIS AFTN...EXPECT HIGH MVFR TO LOW VFR CIGS TO PERSIST UNTIL AROUND 30/04-07Z...WITH LOWERING CIGS AND POSSIBLY PATCHY DENSE FOG AND IFR CIGS LATER TONIGHT. MOSTLY LIGHT AND VRBL WINDS...CIRCULATING AROUND LOW PRESSURE./VII/ && .PREV DISCUSSION... /ISSUED 1100 AM CDT THU MAY 29 2014/ DISCUSSION... THE UPPER LOW REMAINS CENTERED OVER EXTREME SE AR THIS MORNING...WITH THE SHORT TERM PROGS IN GENERAL AGREEMENT WITH THE LOW WOBBLING OVER THIS AREA AND NE LA THROUGH THE AFTERNOON BEFORE SLOWLY RETROGRADING W INTO SW AR/NW LA TONIGHT. A 40NM MILE WIDE BAND OF CONVECTION OVER SCNTRL AND NE LA AHEAD OF THE LOW HAS NOT SHOWN ANY WWD BACKBUILDING INTO THE ERN SECTIONS OF NCNTRL LA THIS MORNING...WITH THE HRRR AND 12Z NAM MAINTAINING THIS CONVECTION JUST E OF THE REGION THROUGH AT LEAST EARLY AFTERNOON BEFORE SHUNTING IT E ACROSS THE MS RIVER. HOWEVER...VISIBLE SATELLITE DOES REVEAL TOWERS DEVELOPING OVER MUCH OF THE REGION...WITH A MORE AGITATED CU FIELD NEAR/NW OF THE CLOSED LOW OVER WCNTRL AR/SE OK. WITH ADDED HEATING...SHOULD SEE SCT CONVECTION DEVELOP WITHIN THE NEXT HOUR OR SO OVER THESE AREAS...WHICH WOULD SHIFT SSW INTO EXTREME NE TX/SW AR/NW LA DURING THE AFTERNOON. DID REDUCE POPS THIS MORNING AREAWIDE GIVEN THE LACK OF CONVECTION ATTM...AND ALSO TONED DOWN POPS SLIGHTLY /TO LIKELY/ ACROSS SCNTRL AR/ERN SECTIONS OF NCNTRL LA. MID/HIGH CHANCE POPS SHOULD SUFFICE OVER MUCH OF E TX/WCNTRL LA...FARTHER AWAY FROM THE CENTER OF THE CLOSED LOW. MUCH OF THIS CONVECTION SHOULD WIND DOWN THIS EVENING WITH THE LOSS OF HEATING. DID MAKE MINOR ADJUSTMENTS TO MAX TEMPS THIS AFTERNOON...MAINLY TO LOWER THEM A COUPLE DEGREES ACROSS SW AR...AND ALSO RAISING THEM SLIGHTLY ACROSS THE WRN SECTIONS OF E TX WHICH ARE ALREADY IN THE MID/UPPER 70S AS OF 1530Z. OTHERWISE...THE REMAINDER OF THE FORECAST IS ON TRACK. ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY. 15 && .PRELIMINARY POINT TEMPS/POPS... SHV 81 68 83 68 86 / 60 30 70 30 50 MLU 80 67 82 67 86 / 70 30 70 30 50 DEQ 79 67 83 67 85 / 60 30 70 30 40 TXK 80 67 83 67 86 / 60 40 70 40 50 ELD 78 67 83 66 86 / 70 40 60 30 50 TYR 84 68 83 68 85 / 40 20 60 40 30 GGG 82 68 83 68 86 / 40 30 60 40 30 LFK 84 68 83 69 86 / 30 30 60 30 40 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1100 AM CDT THU MAY 29 2014 .DISCUSSION... THE UPPER LOW REMAINS CENTERED OVER EXTREME SE AR THIS MORNING...WITH THE SHORT TERM PROGS IN GENERAL AGREEMENT WITH THE LOW WOBBLING OVER THIS AREA AND NE LA THROUGH THE AFTERNOON BEFORE SLOWLY RETROGRADING W INTO SW AR/NW LA TONIGHT. A 40NM MILE WIDE BAND OF CONVECTION OVER SCNTRL AND NE LA AHEAD OF THE LOW HAS NOT SHOWN ANY WWD BACKBUILDING INTO THE ERN SECTIONS OF NCNTRL LA THIS MORNING...WITH THE HRRR AND 12Z NAM MAINTAINING THIS CONVECTION JUST E OF THE REGION THROUGH AT LEAST EARLY AFTERNOON BEFORE SHUNTING IT E ACROSS THE MS RIVER. HOWEVER...VISIBLE SATELLITE DOES REVEAL TOWERS DEVELOPING OVER MUCH OF THE REGION...WITH A MORE AGITATED CU FIELD NEAR/NW OF THE CLOSED LOW OVER WCNTRL AR/SE OK. WITH ADDED HEATING...SHOULD SEE SCT CONVECTION DEVELOP WITHIN THE NEXT HOUR OR SO OVER THESE AREAS...WHICH WOULD SHIFT SSW INTO EXTREME NE TX/SW AR/NW LA DURING THE AFTERNOON. DID REDUCE POPS THIS MORNING AREAWIDE GIVEN THE LACK OF CONVECTION ATTM...AND ALSO TONED DOWN POPS SLIGHTLY /TO LIKELY/ ACROSS SCNTRL AR/ERN SECTIONS OF NCNTRL LA. MID/HIGH CHANCE POPS SHOULD SUFFICE OVER MUCH OF E TX/WCNTRL LA...FARTHER AWAY FROM THE CENTER OF THE CLOSED LOW. MUCH OF THIS CONVECTION SHOULD WIND DOWN THIS EVENING WITH THE LOSS OF HEATING. DID MAKE MINOR ADJUSTMENTS TO MAX TEMPS THIS AFTERNOON...MAINLY TO LOWER THEM A COUPLE DEGREES ACROSS SW AR...AND ALSO RAISING THEM SLIGHTLY ACROSS THE WRN SECTIONS OF E TX WHICH ARE ALREADY IN THE MID/UPPER 70S AS OF 1530Z. OTHERWISE...THE REMAINDER OF THE FORECAST IS ON TRACK. ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY. 15 && .PRELIMINARY POINT TEMPS/POPS... SHV 81 68 83 68 86 / 60 30 70 30 50 MLU 80 67 82 67 86 / 70 30 70 30 50 DEQ 79 67 83 67 85 / 60 30 70 30 40 TXK 80 67 83 67 86 / 60 40 70 40 50 ELD 78 67 83 66 86 / 70 40 60 30 50 TYR 84 68 83 68 85 / 40 20 60 40 30 GGG 82 68 83 68 86 / 40 30 60 40 30 LFK 84 68 83 69 86 / 30 30 60 30 40 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 15
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1156 PM EDT FRI MAY 30 2014 .AVIATION... //DISCUSSION... LIGHT EASTERLY TO VARIABLE WINDS WILL VEER TO THE SOUTHEAST AND INCREASE TO AROUND 8 KTS BY MID MORNING. CLEAR SKIES WILL HOLD THROUGH THE PERIOD. //DTW THRESHOLD THREATS... * NONE. && .PREV DISCUSSION...ISSUED 335 PM EDT FRI MAY 30 2014 SHORT TERM... REST OF TODAY THROUGH TONIGHT SURFACE ANALYSIS INDICATES HIGH PRESSURE IS RELATIVELY WEAK OVER LOWER MICHIGAN TODAY IN ADVANCE OF A WEAK BACKDOOR COLD FRONT OVER NORTHERN LAKE HURON THAT MARKS THE LEADING EDGE OF STRONGER HIGH PRESSURE OVER NORTHERN ONTARIO. THE LOWER MICHIGAN HIGH PRESSURE IS WEAK BUT IS IN FULL CONTROL OF THE WEATHER ACROSS THE REGION AND WILL PROVIDE A SUNNY SKY THROUGH THE EARLY EVENING WITH TEMPERATURES SETTLING OFF HIGHS AROUND 80. THE USUAL EXCEPTION IS ALONG THE SHORELINES WHERE COOLER READINGS WILL BE ENSURED BY THE LAKE BREEZE. FARTHER INLAND...THE WEAK PRESSURE GRADIENT IS SUSCEPTIBLE TO MODIFICATION BY DIFFERENTIAL HEATING BETWEEN LAND AND WATER WHICH REPRESENTS ABOUT THE ONLY OTHER NOTABLE ASPECT OF THE WEATHER WORTH DISCUSSION. LOWER SURFACE PRESSURE OVER INLAND AREAS WILL QUICKLY FILL TOWARD SUNSET AND OPEN THE DOOR FOR A NOTICEABLE INLAND RELEASE OF THE LAKE BREEZE. IN THIS CASE...THE PROCESS WILL BE A HYBRID OF DIFFERENTIAL HEATING LOSS AND THE BACKDOOR FRONT WASHING OUT AS IT ENTERS SE MICHIGAN LEAVING THE NET RESULT OF BUILDING HIGH PRESSURE AFTER MIDNIGHT. BOTH THE NAM AND RAP SUGGEST A LIGHT/VARIABLE SURFACE WIND BECOMING NE DURING THE EVENING AND THEN LINGERING AROUND 5 KNOTS THROUGH THE NIGHT...JUST STRONG ENOUGH TO INHIBIT RADIATIONAL COOLING COMPARED TO THE LAST COUPLE OF NIGHTS. MIN TEMPS IN THE UPPER 40S TO LOWER 50S THEN LOOK SOLID BY SUNRISE SATURDAY. LONG TERM... UPPER LEVEL RIDGE CENTER (587 DAM AT 500 MB) OVER THE WESTERN GREAT LAKES THIS MORNING WILL BE SLIDING SOUTHEAST INTO THE OHIO VALLEY TOMORROW. INCREASING LOW LEVEL SOUTHEAST FLOW WILL TEMPER THE UPWARD TREND IN TEMPERATURES...AND DO NOT FORESEE TOMORROW BEING MUCH WARMER THAN TODAY...AROUND 80 DEGREES/LOWER 80S ACROSS MOST LOCATIONS AS 850 MB TEMPS FORECASTED TO HOLD AROUND 12 C. INCREASING SOUTHWEST FLOW ABOVE THE SURFACE ON SUNDAY WILL LEAD TO FURTHER WARMING...AS 850 MB TEMPS RISE TO 15 C (PER 12Z UKMET WHICH LIES IN BETWEEN THE COOLER NAM/WARMER GFS)...SUPPORTIVE OF MID 80S...ESPECIALLY WEST OF US-23...FARTHER REMOVED FROM THE BACKED SURFACE FLOW OFF THE COLD LAKES. GOOD SURGE OF MOISTURE SUNDAY NIGHT INTO MONDAY...AS PW VALUES RISE TOWARD 1.75 INCHES. SOME UPPER LEVEL ENERGY/PV FROM UPPER LEVEL LOW OVER THE WESTERN GULF COAST LOOKS TO BE SHEARING OFF TO THE NORTHEAST WITH THE INCREASING AND DEEP SOUTHWEST FLOW...SUPPORTING A CHANCE OF SHOWERS AND THUNDERSTORMS LATE SUNDAY NIGHT WITH THE HELP OF A MODESTLY INCREASED NOCTURNAL LOW LEVEL JET. DEEP MOISTURE IN PLACE ON MONDAY IN UNCAPPED ENVIRONMENT...WITH SOME SEMBLANCE OF A WARM FRONT STRADDLED ACROSS NORTHERN LOWER MICHIGAN SHOULD BE SUFFICIENT FOR NUMEROUS ACTIVITY...WHICH WILL LIMIT MAX TEMPS AND CORRESPONDING INSTABILITY...AS MODELS SUGGESTING DEW PTS PUSHING INTO THE MID TO UPPER 60S. LOOKING AT HEAVY RAIN AS MAIN HAZARD...AS 0-6 KM SHEAR IS NOT TERRIBLY IMPRESSIVE...AROUND 20 KNOTS. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO CONTINUE MONDAY NIGHT AS DEEP MOISTURE REMAINS IN PLACE AHEAD OF A SHORTWAVE ADVANCING ACROSS THE NORTHERN GREAT LAKES. THE MOISTURE WILL BE SHUNTED EAST OF THE AREA TUESDAY AS A COLD FRONT PASSES THROUGH. CHANCE POPS ARE IN PLACE TUESDAY TO ACCOUNT FOR UNCERTAINTY IN TIMING OF FRONTAL PASSAGE...THOUGH LATEST INDICATIONS ARE ANY PRECIPITATION WOULD FAVOR THE MORNING HOURS. A PERIOD OF DRY WEATHER THEN LOOKS TO TAKE HOLD AS BRIEF SHORTWAVE RIDGING BUILDS IN. THE PATTERN REMAINS PROGRESSIVE THOUGH AS SHORTWAVE ENERGY EJECTS OUT OF THE PLAINS AND MOISTURE INCREASES...SPELLING A RETURN OF PRECIP CHANCES FROM WEDNESDAY NIGHT THROUGH THE END OF THE WEEK. TEMPERATURES LOOK TO FLUCTUATE IN THE NEAR TO SLIGHTLY ABOVE NORMAL RANGE FROM TUESDAY ONWARD. MARINE... HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EASTERN GREAT LAKES THROUGH THE WEEKEND. WEAK GRADIENT FLOW AND STABLE CONDITIONS SUSTAINED BY THE COLD WATER WILL LEAD TO VERY LITTLE FLOW. SOME MODEST INCREASE IN WINDS ARE EXPECTED ON SUNDAY AS WIND DIRECTION BECOMES SOUTHERLY...WITH INCREASING MOISTURE LEADING SHOWERS AND THUNDERSTORMS LIKELY ON MONDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....JVC SHORT TERM...BT LONG TERM....SF/DT MARINE.......SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
908 PM MDT FRI MAY 30 2014 .UPDATE... WEAK VORTICITY MOVING NE THROUGH THE AREA COMBINED WITH AN UNSTABLE AIRMASS AND INCREASING MOISTURE ACROSS THE SOUTHERN PART OF THE AREA TO PRODUCE WIDELY SCATTERED THUNDERSTORMS THIS EVENING. LATEST MESOANALYSIS SHOWED A STABILIZING AIRMASS AND IR SATELLITE IMAGERY HAD WARMING CLOUD TOPS. ECHOES ON RADAR WERE WEAKENING AS WELL. EXPECT ONLY ISOLATED THUNDERSTORMS THROUGH 06Z AS CONDITIONS WILL NOT CHANGE MUCH SO HAVE LOWERED POPS. AFTER 06Z...A STRONGER WAVE MOVING THROUGH ID WILL REACH NW MT...INCREASING CHANCES OF PRECIPITATION OVER THE NW FORECAST AREA. KEPT SCATTERED POPS THERE AND WENT WITH SLIGHT CHANCE FOR THE REST OF THE AREA...EXCEPT KEPT SCATTERED POPS OVER THE NE BIG HORNS NEAR THE HIGHER MOISTURE. 850 MB TEMPERATURES WILL GENERALLY BE IN THE TEENS OVERNIGHT. THE FORECAST LOWS LOOKED GOOD GIVEN LATEST SURFACE OBSERVATIONS AND MODEL GUIDANCE THAT WAS IN GOOD AGREEMENT. UPPER PACIFIC TROUGH WILL APPROACH THE AREA ON SAT BRINGING INCREASING LIFT TO THE REGION. INCREASING 850 MB LOW-LEVEL JET WILL HELP FURTHER MOISTEN THE AIRMASS. AN INVERTED TROUGH WILL MOVE OVER CENTRAL AND EASTERN PARTS OF THE AREA PROVIDING A FOCUS FOR THUNDERSTORMS. HIGH CAPES AND SUPPORTIVE VALUES OF BULK SHEAR WILL BE SUPPORTIVE OF SEVERE WEATHER IN THE AFTERNOON AND EVENING. ARTHUR && .SHORT TERM...VALID FOR SAT AND SUN... OUR REGION IS AT RISK FOR SEVERE THUNDERSTORMS ON SATURDAY...WITH LARGE HAIL...DAMAGING WINDS...HEAVY RAIN AND EVEN AN ISOLATED TORNADO POSSIBLE. PLEASE TAKE NOTE AND BE PREPARED EVERYONE. FOR TONIGHT...WEAK ENERGY LIFTING OUT OF THE CENTRAL ROCKIES COMBINED WITH A STEADY INCREASE IN LOW TO MID LEVEL MOISTURE WILL RESULT IN ISOLATED TO SCATTERED SHOWERS/TSTMS. SHOULD SEE SOME INITIATION OVER OUR SOUTHERN MTNS BEFORE THE END OF THE AFTN...AND AS OF 21Z THERE IS A TSTM NEAR CODY. OTHER AREA OF INTEREST IS FAR SE MT AS REMNANT PLUME OF SUBTROPICAL MOISTURE IS PRESENT. THOUGH GREATEST FORCING ASSOCIATED WITH CENTRAL ROCKIES SHORTWAVE SHOULD STAY TO OUR SOUTHEAST...EXPECT SOME SHOWERS INTO CARTER COUNTY THROUGH THE NIGHT. ALSO...ONSET OF MODEST SELY LOW LEVEL JET SHOULD HELP KEEP THE POTENTIAL FOR A FEW SHOWERS/TSTMS COMING OFF THE MTNS INTO OUR LOWER ELEVATIONS ONCE WE GET TO SUNSET AND BEYOND. LATEST HRRR SUGGESTS SOME ACTIVITY LATER THIS EVENING. TSTMS TONIGHT SHOULD BE NON-SEVERE. ON SATURDAY...INGREDIENTS ARE COMING TOGETHER FOR A SIGNIFICANT SEVERE WX EPISODE...WITH INCREASING LARGE SCALE ASCENT PER APPROACHING PAC TROF...A RAPID MOISTENING OF OUR AIRMASS AS WE TAP INTO NEAR 1 INCH PWAT AIR POOLED JUST TO OUR SE...AND VERY FAVORABLE SHEAR AND INSTABILITY DURING THE AFTN AND EVENING. DEWPTS INTO THE 50S AND REASONABLY LOW LCL HEIGHTS SUGGEST AN ISOLD TORNADO IS POSSIBLE...ESPECIALLY EAST OF BILLINGS AS SFC LOW DEVELOPS OVER NORTH CENTRAL WY. SREF SEVERE PARAMETERS CONTINUE TO PEG OUR REGION FOR SEVERE WX TOMORROW...SO OVERALL CONFIDENCE CONTINUES TO INCREASE. A FEW DETAILS TO WORK OUT. SYNOPTIC ASCENT BY 12-18Z TOMORROW IN OUR WEST SUGGESTS SOME SHOWER/TSTM ACTIVITY EARLY IN THE DAY...AND WITH ENOUGH COVERAGE THIS COULD MUDDLE UP THE AIRMASS TO OUR WEST. THIS SHOULD NOT BE AN ISSUE FOR OUR CENTRAL AND EAST WHERE WE SHOULD SEE PLENTY OF TIME FOR DESTABILIZATION...AND LATEST GFS/NAM SHOWS A BREAKING OF THE CAP IN THE BILLINGS AREA BY 2-3PM...WHICH IS STILL A LITTLE ON THE EARLY SIDE. PER THE LONG DURATION OF ASCENT WE COULD SEE A COUPLE ROUNDS OF CONVECTION ROLL THROUGH. PLEASE BE READY FOR DANGEROUS WX TOMORROW FOLKS. UPPER TROF WILL FINALLY MOVE THROUGH THE AREA SUNDAY...WHICH WILL SEE PLENTY OF SHOWER ACTIVITY BUT WITH COOLER AIR AND LESS INSTABILITY SO DO NOT SEE A SEVERE RISK FOR MUCH OF THE REGION. EXCEPTION COULD BE IN OUR FAR EAST WHERE HIGHER THETA-E AIR WILL RESIDE NEAR SFC TROF. THIS COULD BE IMPACTED BY HOW CONVECTION EVOLVES SATURDAY NIGHT. EVEN THOUGH THEY MAY NOT BE SEVERE...WET BULB ZERO HEIGHTS ON THE ORDER OF 3.5-5.5KFT UNDER THE UPPER TROF SUGGEST SMALL HAIL WITH ANY STRONGER CELLS TO OUR WEST. EXPECT HIGH TEMPS IN THE 70S TOMORROW THEN MID 60S TO LOWER 70S ON SUNDAY. A COOLER NIGHT COMING SUNDAY NIGHT AS PCPN TAPERS OFF AND SFC RIDGE SETTLES IN. JKL .LONG TERM...VALID FOR MON...TUE...WED...THU...FRI... ONLY MINOR TWEAKS TO THE INHERITED EXTENDED PERIOD FORECAST ONCE AGAIN THIS AFTERNOON. THE PATTERN REMAINS UNSETTLED THROUGHOUT THE EXTENDED PERIOD. EVEN THOUGH PERIODIC PRECIPITATION IS EXPECTED...TEMPERATURES SHOULD BE MAINLY ABOVE NORMAL IN PART DUE TO WARMER OVERNIGHT LOWS. MONDAY CONTINUES THE COOL...COMPARED TO RECENT DAYS...AND WET TREND AS AN UPPER LOW LINGERS OVER THE NORTHEAST CORNER OF THE STATE CIRCULATING ADDITIONAL MOISTURE INTO THE AREA. DRIER AIR ALOFT DOES START TO GET PULLED INTO THE WEST...SO PRECIP AMOUNTS SHOULD BE DECREASING SOME ON MONDAY. TUESDAY SHOULD BE IN BETWEEN SYSTEMS...BUT INCREASED SUNSHINE SHOULD TRIGGER DIURNAL SHOWERS AND THUNDERSTORMS. TEMPS WILL BE A BIT WARMER...AND DID RAISE TEMPERATURES SLIGHTLY. ANOTHER UPPER TROF APPEARS TO SWING THROUGH THE REGION TUESDAY NIGHT AND WEDNESDAY...BRINGING ANOTHER IMPROVED CHANCE OF EXTENSIVE PRECIP ACROSS THE REGION. THE PATTERN TURNS SOMEWHAT DRIER AND ZONAL BY THURSDAY. AIRMASS SHOULD REMAIN UNSTABLE...BRINGING CONTINUED POTENTIAL FOR AFTERNOON AND EVENING SHOWER AND THUNDERSTORMS EACH DAY...ESPECIALLY OVER THE MOUNTAINS. AAG && .AVIATION... WEAK ENERGY LIFTING OUT OF THE CENTRAL ROCKIES WILL SPREAD ISOLATED TO WIDELY SCATTERED SHOWERS AND A FEW TSTMS TO THE REGION TONIGHT. LOCAL MVFR CAN BE EXPECTED ESPECIALLY ALONG THE FOOTHILLS AND IN FAR SE MT...WITH OCCASIONAL MTN OBSCURATIONS. ON SATURDAY...OUR REGION IS AT RISK FOR SEVERE THUNDERSTORM ACTIVITY WITH LARGE HAIL...DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. EXPECT LOCAL MVFR/IFR IN THE HEAVIER SHOWERS. ALL TAF SITES COULD BE IMPACTED BY THUNDERSTORM ACTIVITY ON SATURDAY...WITH THE GREATEST CHANCE OF SEVERE STORMS AFTER 18Z. JKL && .PRELIMINARY POINT TEMP/POPS... SAT SUN MON TUE WED THU FRI ----------------------------------------------------------- BIL 053/075 056/069 048/068 049/075 054/074 052/076 053/073 26/T 67/T 45/T 53/T 55/T 32/T 23/T LVM 046/074 048/069 043/067 044/074 046/071 044/074 044/073 26/T 56/T 55/T 53/T 44/T 33/T 33/T HDN 051/078 056/070 047/069 048/077 053/077 051/078 052/074 26/T 67/T 45/T 53/T 55/T 32/T 23/T MLS 054/079 058/072 051/069 049/075 054/075 055/077 054/072 25/T 76/T 55/T 43/T 44/T 33/T 33/T 4BQ 054/080 058/072 050/070 050/075 053/075 054/077 053/073 24/T 66/T 45/T 43/T 55/T 44/T 43/T BHK 051/076 056/071 050/067 048/072 051/072 052/074 052/070 23/T 77/T 55/T 43/T 34/T 43/T 33/T SHR 048/080 052/071 046/069 045/075 048/072 048/073 049/072 26/T 66/T 35/T 54/T 44/T 43/T 33/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1223 AM CDT THU MAY 29 2014 .SYNOPSIS... ISSUED AT 356 PM CDT WED MAY 28 2014 THE CENTRAL PLAINS ARE UNDERNEATH A LARGE 500HPA RIDGE AHEAD OF AN INCOMING TROUGH AFFECTING THE PACIFIC NORTHWEST. THE AREA OF LOW PRESSURE ALOFT HAS MOVED INTO THE MISSISSIPPI DELTA REGION. AT THE SURFACE...ONE LOW PRESSURE SYSTEM EXISTS ACROSS THE FAR NORTHERN PLAINS AND ONE OVER THE LOWER GREAT LAKES. HIGH PRESSURE SITUATED IN SOUTHERN COLORADO COMBINED WITH THE UPPER LEVEL RIDGE ARE PROVIDING HOT AND MAINLY DRY CONDITIONS TO NEBRASKA. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 356 PM CDT WED MAY 28 2014 ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON ACROSS PORTIONS OF THE WESTERN SANDHILLS AND SOUTHWEST NEBRASKA. THE HRRR MODEL HAS BEEN HINTING AT DEVELOPMENT FOR SEVERAL RUNS AND A CUMULUS FIELD SHOWED UP ON VISIBLE SATELLITE EARLY AFTERNOON. IN ADDITION...MANY LOCATIONS HAVE REACHED THE CONVECTIVE TEMPERATURE BASED ON THE 28/12Z KLBF RAOB. ANY THUNDERSTORM SHOULD DISSIPATE SHORTLY AFTER SUNSET AS THE CAP STRENGTHENS. TEMPERATURE TRENDS FOR OVERNIGHT LOWS AND THURSDAY HIGHS LOOKED GOOD FROM PREVIOUS FORECAST. ONLY CHANGES WERE DROPPED A DEGREE OR SO TONIGHT BASED ON GUIDANCE AND THE DEW POINT FORECAST...AND RAISED A DEGREE THURSDAY FOR CONTINUED SUNSHINE AND SOUTH WINDS. MOISTURE ADVECTS INTO THE AREA THURSDAY AHEAD OF THE NEXT WEATHER SYSTEM...AS SURFACE DEW POINTS REACH THE LOWER 60S ACROSS NORTH CENTRAL NEBRASKA. ANY PRECIPITATION WILL HOLD OFF UNTIL THE LONG TERM FORECAST PERIOD. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 356 PM CDT WED MAY 28 2014 AN ACTIVE WEATHER PATTERN WILL BE ONGOING ACROSS THE CENTRAL PLAINS LATER THIS WEEK INTO NEXT WEEK. THE UPPER LEVEL LOW CURRENTLY OVER ARKANSAS/LOUISIANA AND EASTERN TEXAS WILL SEE LITTLE MOVEMENT OVER THE NEXT SEVERAL DAYS AS IT BECOMES CUTOFF FROM THE GENERAL FLOW AND REMAINS NEARLY STATIONARY UNDER THE RIDGE WHICH WILL BE CENTERED OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY AT 00Z FRIDAY. OVER THE NEXT SEVERAL DAYS THE RIDGE AXIS WILL MOVE EASTWARD AS A STRONG TROUGH MOVES ONSHORE OVER THE WEST COAST ON SATURDAY. THIS PATTERN SHIFT WILL BRING STRONGER UPPER LEVEL FLOW TO THE REGION...ALONG WITH A MULTITUDE OF WEAK BOUTS OF SHORTWAVE ENERGY FROM THE SOUTHWEST FLOW INTO THE CENTRAL PLAINS. ALTHOUGH THE MODELS ARE IN GOOD CONSENSUS WITH THE GENERAL PATTERN...THERE IS SOME DISCONTINUITY ON THE TRACK OF THE SHORTWAVES AS WELL AS THE MOVEMENT OF THE LONGWAVE TROUGH OUT WEST INTO NEXT WEEK. THEREFORE...USED A MODEL CONSENSUS FOR MUCH OF THE LONG TERM PORTION OF THE FORECAST AS CONFIDENCE ISN/T REAL HIGH ON TIMING OF PRECIPITATION CHANCES. STARTING THURSDAY EVENING...RIDGING IS STILL WELL IN PLACE ACROSS THE CENTRAL PLAINS AND WITH THE MID-LEVEL FLOW NORTH-NORTHWEST CONVECTION DEVELOPING ACROSS NORTHERN COLORADO AND THE WESTERN PANHANDLE MAY JUST SKIRT THE NORTHWEST PART OF THE FORECAST AREA. SO LIMITED THE CHANCES FOR SHOWERS AND STORMS TO PORTIONS OF SHERIDAN COUNTY. DURING THE DAY ON FRIDAY...SHOWER AND STORM CHANCES WILL AGAIN BE CONFINED TO AREAS OVER THE WESTERN PART OF THE FORECAST AREA...MAINLY THE PANHANDLE AND THE WESTERN SANDHILLS AS CONVECTION SHOULD DEVELOP OVER THE HIGHER ELEVATIONS ACROSS COLORADO AND THE WESTERN PANHANDLE WHERE THERE WILL BE BETTER SHORTWAVE ENERGY...ALONG WITH SOME UPSLOPE FLOW AND A FOCUS OF MOISTURE TRANSPORT. THE LOW LEVEL JET WILL VEER INTO THE EVENING WHICH WILL THEN SUPPORT STORMS TRANSITIONING EAST ACROSS NORTHERN NEBRASKA AND INTO SOUTH DAKOTA. PRECIPITATION CHANCES HAVE BEEN TRENDED IN THIS DIRECTION. ON SATURDAY A FAIRLY STRONG SHORTWAVE TROUGH IS EXPECTED TO MOVE ACROSS THE NORTHERN PLAINS AND INTO NORTHERN NEBRASKA. THIS WILL PUSH A COLD FRONT INTO THE FORECAST AREA THROUGH THE DAY HOWEVER IT DOESN/T LOOK TO PROGRESS VERY FAR EAST. EXPECTING TO GET DEVELOPMENT ALONG THE FRONT SATURDAY AFTERNOON. ANY STORMS DEVELOPING ON SATURDAY COULD GET STRONG TO SEVERE AS THE INCREASE IN THE UPPER LEVEL FLOW WILL HELP TO STRENGTHEN THE DEEP LAYER SHEAR TO GET STORMS HAVE THE POTENTIAL TO BECOME MORE ORGANIZED. BEYOND SATURDAY IS WHEN THE DIFFERENCES IN TIMING OF ANY SHORTWAVE ENERGY MOVING THROUGH THE AREA BECOME MORE APPARENT. SO THE CHANCES FOR SHOWERS AND THUNDERSTORMS FOR MUCH OF THE AREA CONTINUE DAILY THROUGH THE EARLY PORTIONS OF NEXT WEEK. ALTHOUGH SEVERE STORMS ARE NOT OUT OF THE QUESTION ANY DAY AS THERE SHOULD BE DECENT INSTABILITY AND WIND SHEER EACH DAY...THERE ISN/T A PERIOD THAT LOOKS BETTER THAN OTHERS TO HIGHLIGHT THE CHANCES FOR SEVERE STORMS. AS FOR TEMPERATURES...FRIDAY WILL BE ANOTHER WARM DAY WITH HIGHS IN THE MID TO UPPER 80S. ON SATURDAY...THE NORTHWEST MAY BE A BIT COOLER IN THE 70S AS THE COLD FRONT MOVES THROUGH THAT AREA...WITH THE REMAINDER OF THE FORECAST AREA IN THE 80S. THEN THE REST OF THE FORECAST PERIOD HAS HIGHS IN THE 70S AND 80S AS SHOWERS/STORMS/CLOUDS WILL PLAGUE MUCH OF THE AREA KEEPING TEMPERATURES IN CHECK. AS FOR LOWS...DEWPOINTS IN THE UPPER 40S TO LOW 60S THROUGHOUT THE PERIOD WILL KEEP TEMPERATURES FROM FALLING TOO FAR AND WILL STAY SLIGHTLY ABOVE NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1222 AM CDT THU MAY 29 2014 OVER THE NEXT 24 HOURS...EXPECT CLEAR SKIES AT THE KLBF AND KVTN TERMINALS. THE EXCEPTION MAY BE SOME SCATTERED MID LEVEL CLOUDINESS AON 8000 FT AGL THURSDAY AFTERNOON. WINDS WILL BE FROM THE SOUTHEAST AT AROUND 10 KTS OVERNIGHT TONIGHT AND THURSDAY EVENING. ON THURSDAY...WIND SPEEDS OF 10 TO 20 KTS ARE EXPECTED WITH SOME GUSTS APPG 25 KTS THURSDAY AFTERNOON AT THE KVTN TERMINAL. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DS SHORT TERM...DS LONG TERM...BROOKS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
139 PM EDT THU MAY 29 2014 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL STALL ACROSS THE EASTERN CAROLINAS TODAY AND FRIDAY...CREATING WIDESPREAD SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH OVER THE WEEKEND BRINGING DRIER AND COOLER AIR TO THE REGION. THIS HIGH PRESSURE WILL PUSH OFFSHORE ON MONDAY...WITH A WARMING TREND EXPECTED INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1:30 PM THURSDAY...FIRST SHOWERS OF THE DAY BREAKING OUT RIGHT ON SCHEDULE. NO LIGHTNING THUS FAR...BUT EXPECT THUNDERSTORMS TO FORM SHORTLY. BASED ON LATEST ANALYSIS AND SPC DISCUSSION LOOKS LIKE SEVERE POTENTIAL A BIT LESS THAN EARLIER EXPECTED...ALTHOUGH WE STILL CANNOT RULE IT OUT. ATMOSPHERE MAY TREND MORE TOWARDS THE MODERATELY UNSTABLE CATEGORY THAN THE STRONGLY UNSTABLE. HAVE TONED BACK SEVERE WORDING IN THE ZONES WITH THE LATEST ISSUANCE...OTHERWISE FORECAST CONTINUES WITH LITTLE CHANGE. COLD FRONT IS CURRENTLY DROPPING SOUTH ACROSS OUR NC COUNTIES. PREVIOUS DISCUSSIONS FOLLOW: ANALYSIS OF MORNING SOUNDINGS AND LATEST DATA CONFIRM A MODERATELY TO STRONGLY UNSTABLE AND MOIST AIRMASS TODAY WITH WEAK VERTICAL SHEAR AND A BOUNDARY-RICH ENVIRONMENT. ALSO...A COLD FRONT CONTINUES TO STEADILY ADVANCE SOUTH AND IS NOW ENTERING PENDER COUNTY. THIS CONFIRMS EARLIER PROGNOSIS...SEE DISCUSSION BELOW...OF A CONVECTIVE-LY ACTIVE AFTERNOON AND EVENING WITH PULSE-TYPE CONVECTION BRINGING THE THREAT OF HEAVY RAIN...FREQUENT LIGHTNING AND DAMAGING WINDS. LATEST HRRR DATA AND MODEL SOUNDINGS INDICATE STORMS WILL BEGIN TO FIRE UP IN THE 1 TO 2 PM TIME-FRAME. FORECAST REMAINS ON TRACK. SEE PREVIOUS DISCUSSION BELOW: A COLD FRONT CURRENTLY DROPPING SOUTH EAST-CENTRAL NORTH CAROLINA WILL REACH SOUTHEASTERN NORTH CAROLINA BY NOON...SLOWING AND PRACTICALLY STALLING AS SUCH FRONTS OFTEN DO DURING INTENSE SOLAR HEATING. THIS FRONT IS A SEPARATE ENTITY FROM A CONVECTIVE OUTFLOW BOUNDARY WHICH HAS STALLED IN THE VICINITY OF THE NC/SC STATE LINE. THIS OUTFLOW BOUNDARY ORIGINATED FROM A LARGE CLUSTER OF OVERNIGHT STORMS IN NORTHEASTERN NORTH CAROLINA. THE BOUNDARY WAS EARLIER VISIBLE ON RADAR LOOPS AND ALTHOUGH IS DIFFICULT TO FIND NOW...IT WILL ALMOST CERTAINLY BECOME VISIBLE THIS AFTERNOON WHEN STORMS BEGIN TO FIRE. THE ENVIRONMENT SHOULD BECOME MODERATELY TO STRONGLY UNSTABLE THIS AFTERNOON WITH SURFACE-BASED CAPE RISING TO 2000-3000 J/KG AND LIFTED INDICES FALLING TO NEAR -7. SYNOPTIC SCALE LOW-LEVEL CONVERGENCE WILL BECOME MAXIMIZED ALONG THE STALLED FRONT. THE ADDITION OF THE SEABREEZE BOUNDARY AND THE OLD OUTFLOW BOUNDARY SHOULD GIVE PLENTY OF POTENTIAL TRIGGERS FOR STORMS TO DEVELOP. LAPSE RATES WILL BE PARTICULARLY STEEP UP THROUGH 650 MB...INDUCING LARGE INITIAL PARCEL ACCELERATION AND A RAPID ERUPTION OF STORMS ONCE CONVECTIVE TEMPERATURES ARE REACHED. FORECAST POPS TODAY RANGE FROM 70 PERCENT ACROSS INTERIOR SE NORTH CAROLINA TO 40 PERCENT ALONG THE SANTEE RIVER...GRADUALLY TAPERING DOWN LATE THIS EVENING AS CONVECTIVE OVERTURNING STABILIZES THE ATMOSPHERE. MID AND UPPER LEVEL WINDS WILL BE EXCEEDINGLY WEAK TODAY...5-8 KT AT 850 MB...5-10 KT AT 500 MB...AND AROUND 10 KT AT 300 MB. THIS SHOULD PROMOTE SINGLE-CELL STORMS WITH VERY LITTLE ORGANIZATION. STORMS WILL CHOKE ON THEIR OWN COLD OUTFLOW BUT BOUNDARY COLLISIONS SHOULD EASILY CREATE A NUMBER OF NEW CELLS. VERY SLOW CELL MOTION WILL PRODUCE A PATCHWORK OF VERY HEAVY RAINFALL AMOUNTS...POSSIBLY 2-3 INCHES IN ISOLATED SPOTS...INTERSPERSED WITH LIGHTER TOTALS. HIGH WINDS FROM WET MICRO BURSTS WILL BE THE MAIN SEVERE WEATHER THREAT WITH A POTENTIAL OF ISOLATED HAIL AS WELL. THESE STORMS COULD ALSO BECOME VERY PROLIFIC LIGHTNING PRODUCERS SINCE THEORETICAL PARCEL-MINUS-ENVIRONMENTAL TEMPERATURE DIFFERENCES SHOULD REMAIN LARGE (6-8 DEGREES C) UP THROUGH THE -10 TO -30C LAYER. HIGH TEMPERATURES SHOULD REACH THE UPPER 80S TO AROUND 90 TODAY...WARMEST ACROSS THE SC PEE DEE REGION. LOWS TONIGHT SHOULD FALL INTO THE UPPER 60S FOR MOST AREAS. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM THURSDAY...INTERESTING PATTERN FOR THE SHORT TERM...AS AMPLIFIED AND BLOCKED 5H FLOW FORCES SYSTEMS TO RETROGRADE ALOFT. TWO LARGE UPPER LOWS...ONE NEARLY STATIONARY ACROSS THE ARKLATEX REGION...AND ANOTHER RE-STRENGTHENING OVER SOUTHEAST CANADA...WILL CONTINUE THEIR LOCAL INFLUENCES INTO THE WKND...WITH THE CAROLINAS REMAINING SANDWICHED BETWEEN THE TWO. ATOP THE ARKLATEX LOW...A RIDGE OF HIGH PRESSURE BLOSSOMING NEAR THE GREAT LAKES WILL BE FORCED SOUTHEAST TOWARDS THE AREA ON SATURDAY AS IT...ALMOST LITERALLY...GETS SQUEEZED OUT BY THE NORTHEAST TROUGH...FORCING THE ARKLATEX LOW TO RETROGRADE AND WEAKEN ACROSS EAST TEXAS. AT THE SURFACE...A BACK DOOR TYPE COLD FRONT WILL SINK SLOWLY ACROSS THE AREA FRIDAY...DROPPING SOUTH LATE SATURDAY...AS ITS MOTION GETS BOTH ASSISTED (BY NORTHEAST TROUGH) AND IMPEDED (BY UPPER RIDGE)...CAUSING ITS SLOW PROGRESSION. THIS FRONT WILL BE THE IMPETUS FOR CONVECTION EACH DAY...AND THE MAIN CHALLENGE FOR TEMPS AS WELL. FRIDAY LOOKS TO BE THE MORE ACTIVE...AND WARMER DAY OF THE SHORT TERM. FRONT WILL BE ROUGHLY BISECTING THE CWA...ALIGNED EAST TO WEST NEAR THE SC/NC LINE...FRIDAY MORNING. THE AIR MASS IMMEDIATELY BEHIND THIS FEATURE IS NOT DRASTICALLY DIFFERENT THAN THAT AHEAD OF IT...SO WHILE TEMPS ACROSS THE NORTHERN HALF OF THE CWA WILL BE SLIGHTLY COOLER THAN THOSE IN THE SOUTH...STILL EXPECT HIGHS IN THE LOW/MID 80S NORTH...MID/UPR 80S SOUTH. LOWS FRIDAY NIGHT WILL DROP TO NEAR CLIMO VALUES...LOW/MID 60S...HIGHEST IN THE SOUTHERN ZONES. MORE SIGNIFICANTLY...SHOWERS/TSTMS ARE EXPECTED TO BE WIDESPREAD ON FRIDAY...AS EVIDENCED BY A LARGE SWATH OF 90% 12-HR SREF PROBS FOR 0.01 INCHES ACROSS THE AREA. THE HIGHEST PROBS ARE ACROSS SC...BUT THE ENTIRE CWA IS LIKELY TO SEE CONVECTION ON FRIDAY. SBCAPE VALUES RISE TO AROUND 1500 J/KG SOUTH OF THE FRONT...BUT RAPIDLY FALL OFF BEHIND IT. A SIMILAR PWAT GRADIENT EXISTS AS WELL...FROM ABOUT 1.9 INCHES WELL SOUTH...TO 1.3 INCHES FAR NORTH...IN A COLUMN CHARACTERIZED BY AROUND 10 KFT OF WARM CLOUD DEPTH. THIS SETUP SUPPORTS VERY HEAVY RAIN POTENTIAL...AS EFFICIENT PRECIPITATION PROCESSES ARE LIKELY DUE TO MODERATELY STRONG UPDRAFTS INTO A DEEPLY SATURATED COLUMN. ALTHOUGH LAPSE RATES ARE NOT VERY IMPRESSIVE...CREATING LOW NORMALIZED-CAPE VALUES...THIS HAS BEEN SHOWN TO FURTHER ENHANCE PRECIPITATION EFFICIENCY...AND THUS HEAVY RAINFALL WILL BE THE PRIMARY RISK ON FRIDAY...ESPECIALLY NOTING THE ADDED CAVEAT OF SLOW STORM MOTIONS. AT THE SAME TIME...A MID- LEVEL IMPULSE IS PROGGED TO ROTATE DOWN WITHIN THE NW FLOW...MOVING ATOP THE FRONT DURING THE LATE AFTN...WHICH WILL ONLY ACT TO ENHANCE COVERAGE AND INTENSITY OF SHOWERS/STORMS. THIS SUGGESTS THE STRONGEST CONVECTION WILL BE IN THE SOUTHERN THIRD OF THE CWA...AND HIGHEST POP...LIKELY...WILL BE SHOWN THERE...TRENDING DOWN TO CHC IN THE NORTH. WITH THIS SETUP IN PLACE...AND THURSDAY EXPECTED TO BE WET AS WELL...LOCALIZED FLOODING MAY BECOME A CONCERN...ESPECIALLY ACROSS SOUTH CAROLINA ZONES...AND THIS WILL NEED TO BE MONITORED CLOSELY DURING THE NEXT DAY. A QUIETER DAY SATURDAY...BUT WITH THE FRONT STILL SLOWLY SINKING SOUTH...SOME DIURNALLY ENHANCED SHOWERS/TSTMS ARE POSSIBLE...ESPECIALLY IN THE PEE DEE REGION AND ALONG THE SOUTH SANTEE RIVER. PROFILES SHOW PRETTY QUICK DRYING FROM NORTH TO SOUTH THROUGH THE DAY...SO BEST PRECIP CHANCES WILL BE EARLY IN THE AFTN...WITH POP DROPPING TO SILENT BY THE EVENING. TEMPS WILL BE COOLER BY A FEW DEGREES BEHIND THE FRONT...LOW/MID 80S AREA-WIDE WITH LOWS POTENTIALLY FALLING BELOW 60 IN THE FAR NORTH SATURDAY NIGHT...LOW 60S ELSEWHERE. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 300 AM THURSDAY...UPPER RIDGE DROPS ACROSS THE AREA EARLY IN THE PERIOD...BEFORE FLATTENING INTO THE MIDDLE OF NEXT WEEK. AT THE SURFACE...COOL HIGH PRESSURE DROPS SOUTH OUT OF NEW ENGLAND ON SUNDAY BEFORE MOVING OVERHEAD EARLY NEXT WEEK AND THEN OFFSHORE LATE IN THE EXTENDED. THIS PATTERN PRODUCES MOSTLY QUIET WEATHER WITH SEASONABLE TO SLIGHTLY BELOW CLIMO TEMPS SUN/MON AND WITH MUCH DECREASED HUMIDITY. ALTHOUGH THE UPPER PATTERN FLATTENS NEXT WEEK...THE HIGH PRESSURE MOVING OFFSHORE WILL BEGIN TO DRIVE WARM/MOIST RETURN FLOW BACK INTO THE CAROLINAS TUE/WED. WHILE TEMPS ARE NOT EXPECTED TO REACH WELL ABOVE NORMAL LEVELS LIKE WE SAW FREQUENTLY IN MAY...SLIGHTLY ABOVE CLIMO VALUES ARE EXPECTED FOR THE MIDDLE OF NEXT WEEK...ALONG WITH SLOWLY INCREASING DIURNAL TSTM CHANCES. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 18Z...POSSIBLE PERIODS OF MVFR DUE TO FOG/REDUCED VSBYS IN ISOLATED TO SCATTERED CONVECTION LATER TODAY AND TONIGHT POSSIBLE...AS WELL AS MVFR FOG LATE OVERNIGHT INTO THE EARLY MORNING HOURS. OTHERWISE EXPECT VFR. VFR PREVAILS THIS AFTERNOON WITH VARYING FEW/SCT/BKN CLOUD HEIGHTS...LOW TO HIGH LEVEL AND LIGHT AND VARIABLE WINDS. AN APPROACHING COLD FRONT FROM THE NORTH WILL MOVE DOWN INTO THE AREA TODAY...AND WITH AN OVERALL FAVORABLE ENVIRONMENT...ANTICIPATE INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND INTO THE EVENING HOURS. REDUCED RESTRICTIONS WILL BE POSSIBLE IN ANY HEAVY DOWNPOUR OR PATCHY FOG. WEST WINDS THIS MORNING WILL SHIFT TO THE EAST-NORTHEAST BY THIS AFTERNOON DEPENDING ON THE LOCATION OF THE AFOREMENTIONED FRONTAL BOUNDARY. BUT OVERALL WINDS WILL BE AOB 10 KTS. INTO THE OVERNIGHT HOURS...ACTIVITY WILL TAPER OFF WITH LIGHT WINDS...LOW CIGS AND PATCHY FOG LIKELY...POSSIBLY CREATING MVFR/IFR CONDITIONS THROUGH MORNING. BY FRIDAY MORNING...EXPECT VFR TO PREVAIL WITH LIGHT WINDS. EXTENDED OUTLOOK...SCATTERED SHOWERS/TSTMS WITH BRIEF PERIODS OF SUB-VFR CONDITIONS EXPECTED THROUGH FRIDAY...MAINLY IN THE AFTERNOON AND EARLY EVENING HOURS. VFR SATURDAY THROUGH MONDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1:30 PM THURSDAY...COLD FRONT NOW DROPPING SOUTH ACROSS OUR NC WATERS WITH WINDS TURNING NE NORTH OF CAPE FEAR. NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: A COLD FRONT RECENTLY MOVED SOUTH OF CAPE LOOKOUT AND SHOULD REACH SOUTHEASTERN NORTH CAROLINA NORTH OF CAPE FEAR BEFORE NOON. THE FRONT SHOULD THEN STALL AND TEMPORARILY BECOME DIFFUSE WITH THE DEVELOPING AFTERNOON SEABREEZE CIRCULATION. THIS SHOULD LEAD TO A VARIETY OF WIND DIRECTIONS ACROSS THE COASTAL WATERS: MAINLY NORTHEAST NORTH OF CAPE FEAR...AND MAINLY SOUTHWEST SOUTH OF CAPE FEAR...BUT WITH THE SEABREEZE DETERMINING THE EVENTUAL DIRECTION. FAIRLY WIDESPREAD THUNDERSTORMS SHOULD DEVELOP INLAND THIS AFTERNOON. VERY SLOW MOVEMENT MEANS MOST OF THESE STORM CELLS WILL REMAIN INLAND ON THE WEST SIDE OF THE SEABREEZE...HOWEVER A FEW COULD DRIFT OUT PAST THE BEACHES INTO THE NEARSHORE WATERS. ANY STORMS WILL BE ACCOMPANIED BY GUSTY WINDS AND A GOOD DEAL OF LIGHTNING. THE FRONT SHOULD SINK SOUTHWARD INTO THE MYRTLE BEACH/MURRELLS INLET AREA OVERNIGHT. AS INLAND THUNDERSTORMS DIE DOWN DURING THE EVENING THERE IS THE POTENTIAL THE CONVECTIVE RISK COULD SHIFT OFFSHORE. SEAS CURRENTLY AROUND 2 FEET SHOULD CHANGE LITTLE THROUGH TONIGHT WITH MAINLY LIGHT WINDS EITHER SIDE OF THE FRONT. OBVIOUSLY NEAR ANY THUNDERSTORMS WINDS AND SEAS COULD TEMPORARILY BUILD QUITE A BIT HIGHER. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM THURSDAY...SLOW MOVING BACK DOOR COLD FRONT WILL DROP SOUTH ACROSS THE WATERS...BUT WILL TAKE UNTIL SATURDAY MORNING TO MAKE IT ALL THE WAY SOUTH OF THE AREA. THIS WILL CREATE LIGHT AND VARIABLE WINDS ON FRIDAY...FROM THE NE ON THE NORTH SIDE OF THIS FRONT...AND THE S/SE TO THE SOUTH. BY SATURDAY...ALL WINDS WILL BECOME N/NE WITH A WEAK SURGE CAUSING AN INCREASE IN SPEED TO 10-15 KTS. SEAS FRIDAY WILL BE PRIMARILY 1-2 FT...BUT WILL START TO RISE TOWARDS 3 FT FRIDAY NIGHT ACROSS THE NC WATERS. SATURDAY SEAS WILL BE DRIVEN BY THE ENHANCED NE WINDS...BECOMING 2-4 FT ALL WATERS. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 300 AM THURSDAY... HIGH PRESSURE BUILDING DOWN THE COAST WILL DRIVE A PINCHED GRADIENT OVER THE WATERS ON SUNDAY...WITH NE WINDS OF AROUND 15 KTS COMMON THROUGH THE DAY. THIS HIGH WILL BUILD DOWN ACROSS THE WATERS SUNDAY NIGHT...THEN DRIFT OFFSHORE MONDAY...CAUSING WINDS TO WEAKEN AND VEER SLOWLY...TO THE SW AT 5-10 KTS BY THE END OF THE PERIOD. SEAS OF 2-4 FT ARE EXPECTED SUNDAY WITH A NE WIND CHOP PREDOMINANT WITHIN THE WAVE SPECTRUM. WAVE HEIGHTS FALL TO 2-3 FT MONDAY AS THE WINDS EASE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...TRA/JDW NEAR TERM...REK/TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...SGL MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1019 AM EDT THU MAY 29 2014 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL STALL ACROSS THE EASTERN CAROLINAS TODAY AND FRIDAY...CREATING WIDESPREAD SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH OVER THE WEEKEND BRINGING DRIER AND COOLER AIR TO THE REGION. THIS HIGH PRESSURE WILL PUSH OFFSHORE ON MONDAY...WITH A WARMING TREND EXPECTED INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 10:20 AM THURSDAY...ANALYSIS OF MORNING SOUNDINGS AND LATEST DATA CONFIRM A MODERATELY TO STRONGLY UNSTABLE AND MOIST AIRMASS TODAY WITH WEAK VERTICAL SHEAR AND A BOUNDARY-RICH ENVIRONMENT. ALSO...A COLD FRONT CONTINUES TO STEADILY ADVANCE SOUTH AND IS NOW ENTERING PENDER COUNTY. THIS CONFIRMS EARLIER PROGNOSIS...SEE DISCUSSION BELOW...OF A CONVECTIVE-LY ACTIVE AFTERNOON AND EVENING WITH PULSE-TYPE CONVECTION BRINGING THE THREAT OF HEAVY RAIN...FREQUENT LIGHTNING AND DAMAGING WINDS. LATEST HRRR DATA AND MODEL SOUNDINGS INDICATE STORMS WILL BEGIN TO FIRE UP IN THE 1 TO 2 PM TIME-FRAME. FORECAST REMAINS ON TRACK. SEE PREVIOUS DISCUSSION BELOW: A COLD FRONT CURRENTLY DROPPING SOUTH EAST-CENTRAL NORTH CAROLINA WILL REACH SOUTHEASTERN NORTH CAROLINA BY NOON...SLOWING AND PRACTICALLY STALLING AS SUCH FRONTS OFTEN DO DURING INTENSE SOLAR HEATING. THIS FRONT IS A SEPARATE ENTITY FROM A CONVECTIVE OUTFLOW BOUNDARY WHICH HAS STALLED IN THE VICINITY OF THE NC/SC STATE LINE. THIS OUTFLOW BOUNDARY ORIGINATED FROM A LARGE CLUSTER OF OVERNIGHT STORMS IN NORTHEASTERN NORTH CAROLINA. THE BOUNDARY WAS EARLIER VISIBLE ON RADAR LOOPS AND ALTHOUGH IS DIFFICULT TO FIND NOW...IT WILL ALMOST CERTAINLY BECOME VISIBLE THIS AFTERNOON WHEN STORMS BEGIN TO FIRE. THE ENVIRONMENT SHOULD BECOME MODERATELY TO STRONGLY UNSTABLE THIS AFTERNOON WITH SURFACE-BASED CAPE RISING TO 2000-3000 J/KG AND LIFTED INDICES FALLING TO NEAR -7. SYNOPTIC SCALE LOW-LEVEL CONVERGENCE WILL BECOME MAXIMIZED ALONG THE STALLED FRONT. THE ADDITION OF THE SEABREEZE BOUNDARY AND THE OLD OUTFLOW BOUNDARY SHOULD GIVE PLENTY OF POTENTIAL TRIGGERS FOR STORMS TO DEVELOP. LAPSE RATES WILL BE PARTICULARLY STEEP UP THROUGH 650 MB...INDUCING LARGE INITIAL PARCEL ACCELERATION AND A RAPID ERUPTION OF STORMS ONCE CONVECTIVE TEMPERATURES ARE REACHED. FORECAST POPS TODAY RANGE FROM 70 PERCENT ACROSS INTERIOR SE NORTH CAROLINA TO 40 PERCENT ALONG THE SANTEE RIVER...GRADUALLY TAPERING DOWN LATE THIS EVENING AS CONVECTIVE OVERTURNING STABILIZES THE ATMOSPHERE. MID AND UPPER LEVEL WINDS WILL BE EXCEEDINGLY WEAK TODAY...5-8 KT AT 850 MB...5-10 KT AT 500 MB...AND AROUND 10 KT AT 300 MB. THIS SHOULD PROMOTE SINGLE-CELL STORMS WITH VERY LITTLE ORGANIZATION. STORMS WILL CHOKE ON THEIR OWN COLD OUTFLOW BUT BOUNDARY COLLISIONS SHOULD EASILY CREATE A NUMBER OF NEW CELLS. VERY SLOW CELL MOTION WILL PRODUCE A PATCHWORK OF VERY HEAVY RAINFALL AMOUNTS...POSSIBLY 2-3 INCHES IN ISOLATED SPOTS...INTERSPERSED WITH LIGHTER TOTALS. HIGH WINDS FROM WET MICRO BURSTS WILL BE THE MAIN SEVERE WEATHER THREAT WITH A POTENTIAL OF ISOLATED HAIL AS WELL. THESE STORMS COULD ALSO BECOME VERY PROLIFIC LIGHTNING PRODUCERS SINCE THEORETICAL PARCEL-MINUS-ENVIRONMENTAL TEMPERATURE DIFFERENCES SHOULD REMAIN LARGE (6-8 DEGREES C) UP THROUGH THE -10 TO -30C LAYER. HIGH TEMPERATURES SHOULD REACH THE UPPER 80S TO AROUND 90 TODAY...WARMEST ACROSS THE SC PEE DEE REGION. LOWS TONIGHT SHOULD FALL INTO THE UPPER 60S FOR MOST AREAS. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM THURSDAY...INTERESTING PATTERN FOR THE SHORT TERM...AS AMPLIFIED AND BLOCKED 5H FLOW FORCES SYSTEMS TO RETROGRADE ALOFT. TWO LARGE UPPER LOWS...ONE NEARLY STATIONARY ACROSS THE ARKLATEX REGION...AND ANOTHER RE-STRENGTHENING OVER SOUTHEAST CANADA...WILL CONTINUE THEIR LOCAL INFLUENCES INTO THE WKND...WITH THE CAROLINAS REMAINING SANDWICHED BETWEEN THE TWO. ATOP THE ARKLATEX LOW...A RIDGE OF HIGH PRESSURE BLOSSOMING NEAR THE GREAT LAKES WILL BE FORCED SOUTHEAST TOWARDS THE AREA ON SATURDAY AS IT...ALMOST LITERALLY...GETS SQUEEZED OUT BY THE NORTHEAST TROUGH...FORCING THE ARKLATEX LOW TO RETROGRADE AND WEAKEN ACROSS EAST TEXAS. AT THE SURFACE...A BACK DOOR TYPE COLD FRONT WILL SINK SLOWLY ACROSS THE AREA FRIDAY...DROPPING SOUTH LATE SATURDAY...AS ITS MOTION GETS BOTH ASSISTED (BY NORTHEAST TROUGH) AND IMPEDED (BY UPPER RIDGE)...CAUSING ITS SLOW PROGRESSION. THIS FRONT WILL BE THE IMPETUS FOR CONVECTION EACH DAY...AND THE MAIN CHALLENGE FOR TEMPS AS WELL. FRIDAY LOOKS TO BE THE MORE ACTIVE...AND WARMER DAY OF THE SHORT TERM. FRONT WILL BE ROUGHLY BISECTING THE CWA...ALIGNED EAST TO WEST NEAR THE SC/NC LINE...FRIDAY MORNING. THE AIR MASS IMMEDIATELY BEHIND THIS FEATURE IS NOT DRASTICALLY DIFFERENT THAN THAT AHEAD OF IT...SO WHILE TEMPS ACROSS THE NORTHERN HALF OF THE CWA WILL BE SLIGHTLY COOLER THAN THOSE IN THE SOUTH...STILL EXPECT HIGHS IN THE LOW/MID 80S NORTH...MID/UPR 80S SOUTH. LOWS FRIDAY NIGHT WILL DROP TO NEAR CLIMO VALUES...LOW/MID 60S...HIGHEST IN THE SOUTHERN ZONES. MORE SIGNIFICANTLY...SHOWERS/TSTMS ARE EXPECTED TO BE WIDESPREAD ON FRIDAY...AS EVIDENCED BY A LARGE SWATH OF 90% 12-HR SREF PROBS FOR 0.01 INCHES ACROSS THE AREA. THE HIGHEST PROBS ARE ACROSS SC...BUT THE ENTIRE CWA IS LIKELY TO SEE CONVECTION ON FRIDAY. SBCAPE VALUES RISE TO AROUND 1500 J/KG SOUTH OF THE FRONT...BUT RAPIDLY FALL OFF BEHIND IT. A SIMILAR PWAT GRADIENT EXISTS AS WELL...FROM ABOUT 1.9 INCHES WELL SOUTH...TO 1.3 INCHES FAR NORTH...IN A COLUMN CHARACTERIZED BY AROUND 10 KFT OF WARM CLOUD DEPTH. THIS SETUP SUPPORTS VERY HEAVY RAIN POTENTIAL...AS EFFICIENT PRECIPITATION PROCESSES ARE LIKELY DUE TO MODERATELY STRONG UPDRAFTS INTO A DEEPLY SATURATED COLUMN. ALTHOUGH LAPSE RATES ARE NOT VERY IMPRESSIVE...CREATING LOW NORMALIZED-CAPE VALUES...THIS HAS BEEN SHOWN TO FURTHER ENHANCE PRECIPITATION EFFICIENCY...AND THUS HEAVY RAINFALL WILL BE THE PRIMARY RISK ON FRIDAY...ESPECIALLY NOTING THE ADDED CAVEAT OF SLOW STORM MOTIONS. AT THE SAME TIME...A MID- LEVEL IMPULSE IS PROGGED TO ROTATE DOWN WITHIN THE NW FLOW...MOVING ATOP THE FRONT DURING THE LATE AFTN...WHICH WILL ONLY ACT TO ENHANCE COVERAGE AND INTENSITY OF SHOWERS/STORMS. THIS SUGGESTS THE STRONGEST CONVECTION WILL BE IN THE SOUTHERN THIRD OF THE CWA...AND HIGHEST POP...LIKELY...WILL BE SHOWN THERE...TRENDING DOWN TO CHC IN THE NORTH. WITH THIS SETUP IN PLACE...AND THURSDAY EXPECTED TO BE WET AS WELL...LOCALIZED FLOODING MAY BECOME A CONCERN...ESPECIALLY ACROSS SOUTH CAROLINA ZONES...AND THIS WILL NEED TO BE MONITORED CLOSELY DURING THE NEXT DAY. A QUIETER DAY SATURDAY...BUT WITH THE FRONT STILL SLOWLY SINKING SOUTH...SOME DIURNALLY ENHANCED SHOWERS/TSTMS ARE POSSIBLE...ESPECIALLY IN THE PEE DEE REGION AND ALONG THE SOUTH SANTEE RIVER. PROFILES SHOW PRETTY QUICK DRYING FROM NORTH TO SOUTH THROUGH THE DAY...SO BEST PRECIP CHANCES WILL BE EARLY IN THE AFTN...WITH POP DROPPING TO SILENT BY THE EVENING. TEMPS WILL BE COOLER BY A FEW DEGREES BEHIND THE FRONT...LOW/MID 80S AREA-WIDE WITH LOWS POTENTIALLY FALLING BELOW 60 IN THE FAR NORTH SATURDAY NIGHT...LOW 60S ELSEWHERE. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 300 AM THURSDAY...UPPER RIDGE DROPS ACROSS THE AREA EARLY IN THE PERIOD...BEFORE FLATTENING INTO THE MIDDLE OF NEXT WEEK. AT THE SURFACE...COOL HIGH PRESSURE DROPS SOUTH OUT OF NEW ENGLAND ON SUNDAY BEFORE MOVING OVERHEAD EARLY NEXT WEEK AND THEN OFFSHORE LATE IN THE EXTENDED. THIS PATTERN PRODUCES MOSTLY QUIET WEATHER WITH SEASONABLE TO SLIGHTLY BELOW CLIMO TEMPS SUN/MON AND WITH MUCH DECREASED HUMIDITY. ALTHOUGH THE UPPER PATTERN FLATTENS NEXT WEEK...THE HIGH PRESSURE MOVING OFFSHORE WILL BEGIN TO DRIVE WARM/MOIST RETURN FLOW BACK INTO THE CAROLINAS TUE/WED. WHILE TEMPS ARE NOT EXPECTED TO REACH WELL ABOVE NORMAL LEVELS LIKE WE SAW FREQUENTLY IN MAY...SLIGHTLY ABOVE CLIMO VALUES ARE EXPECTED FOR THE MIDDLE OF NEXT WEEK...ALONG WITH SLOWLY INCREASING DIURNAL TSTM CHANCES. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... AS OF 12Z...VFR WILL PREVAIL THROUGH THE AFTERNOON HOURS WITH THE EXCEPTION OF SOME SHORT-LIVED PERIODS OF MARGINAL MVFR DUE TO FOG THIS MORNING. PERIODS OF MVFR DUE TO FOG/REDUCED VSBYS IN ISOLATED TO SCATTERED CONVECTION LATER TODAY AND TONIGHT POSSIBLE AS WELL. VFR PREVAILS ACROSS THE AREA WITH LIGHT WINDS THIS MORNING...WITH THE EXCEPTION OF MARGINAL MVFR DUE TO PATCHY FOG AT KILM ATTM. AN APPROACHING COLD FRONT FROM THE NORTH WILL MOVE DOWN INTO THE AREA TODAY...AND WITH AN OVERALL FAVORABLE ENVIRONMENT...ANTICIPATE INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND INTO THE EVENING HOURS. REDUCED RESTRICTIONS WILL BE POSSIBLE IN ANY HEAVY DOWNPOUR OR PATCHY FOG. WEST WINDS THIS MORNING WILL SHIFT TO THE EAST-NORTHEAST BY THIS AFTERNOON DEPENDING ON THE LOCATION OF THE AFOREMENTIONED FRONTAL BOUNDARY. BUT OVERALL WINDS WILL BE AOB 10 KTS. INTO THE OVERNIGHT HOURS...ACTIVITY WILL TAPER OFF FOR THE REMAINDER OF THE VALID TAF PERIOD WITH LIGHT WINDS...LOW CIGS AND PATCHY FOG LIKELY...POSSIBLY CREATING MVFR/IFR CONDITIONS THROUGH THE END OF THE PERIOD. EXTENDED OUTLOOK...SCATTERED SHOWERS/TSTMS WITH BRIEF PERIODS OF SUB-VFR CONDITIONS EXPECTED THROUGH FRIDAY...MAINLY IN THE AFTERNOON AND EARLY EVENING HOURS. VFR SATURDAY THROUGH MONDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 10:20 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: A COLD FRONT RECENTLY MOVED SOUTH OF CAPE LOOKOUT AND SHOULD REACH SOUTHEASTERN NORTH CAROLINA NORTH OF CAPE FEAR BEFORE NOON. THE FRONT SHOULD THEN STALL AND TEMPORARILY BECOME DIFFUSE WITH THE DEVELOPING AFTERNOON SEABREEZE CIRCULATION. THIS SHOULD LEAD TO A VARIETY OF WIND DIRECTIONS ACROSS THE COASTAL WATERS: MAINLY NORTHEAST NORTH OF CAPE FEAR...AND MAINLY SOUTHWEST SOUTH OF CAPE FEAR...BUT WITH THE SEABREEZE DETERMINING THE EVENTUAL DIRECTION. FAIRLY WIDESPREAD THUNDERSTORMS SHOULD DEVELOP INLAND THIS AFTERNOON. VERY SLOW MOVEMENT MEANS MOST OF THESE STORM CELLS WILL REMAIN INLAND ON THE WEST SIDE OF THE SEABREEZE...HOWEVER A FEW COULD DRIFT OUT PAST THE BEACHES INTO THE NEARSHORE WATERS. ANY STORMS WILL BE ACCOMPANIED BY GUSTY WINDS AND A GOOD DEAL OF LIGHTNING. THE FRONT SHOULD SINK SOUTHWARD INTO THE MYRTLE BEACH/MURRELLS INLET AREA OVERNIGHT. AS INLAND THUNDERSTORMS DIE DOWN DURING THE EVENING THERE IS THE POTENTIAL THE CONVECTIVE RISK COULD SHIFT OFFSHORE. SEAS CURRENTLY AROUND 2 FEET SHOULD CHANGE LITTLE THROUGH TONIGHT WITH MAINLY LIGHT WINDS EITHER SIDE OF THE FRONT. OBVIOUSLY NEAR ANY THUNDERSTORMS WINDS AND SEAS COULD TEMPORARILY BUILD QUITE A BIT HIGHER. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM THURSDAY...SLOW MOVING BACK DOOR COLD FRONT WILL DROP SOUTH ACROSS THE WATERS...BUT WILL TAKE UNTIL SATURDAY MORNING TO MAKE IT ALL THE WAY SOUTH OF THE AREA. THIS WILL CREATE LIGHT AND VARIABLE WINDS ON FRIDAY...FROM THE NE ON THE NORTH SIDE OF THIS FRONT...AND THE S/SE TO THE SOUTH. BY SATURDAY...ALL WINDS WILL BECOME N/NE WITH A WEAK SURGE CAUSING AN INCREASE IN SPEED TO 10-15 KTS. SEAS FRIDAY WILL BE PRIMARILY 1-2 FT...BUT WILL START TO RISE TOWARDS 3 FT FRIDAY NIGHT ACROSS THE NC WATERS. SATURDAY SEAS WILL BE DRIVEN BY THE ENHANCED NE WINDS...BECOMING 2-4 FT ALL WATERS. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 300 AM THURSDAY... HIGH PRESSURE BUILDING DOWN THE COAST WILL DRIVE A PINCHED GRADIENT OVER THE WATERS ON SUNDAY...WITH NE WINDS OF AROUND 15 KTS COMMON THROUGH THE DAY. THIS HIGH WILL BUILD DOWN ACROSS THE WATERS SUNDAY NIGHT...THEN DRIFT OFFSHORE MONDAY...CAUSING WINDS TO WEAKEN AND VEER SLOWLY...TO THE SW AT 5-10 KTS BY THE END OF THE PERIOD. SEAS OF 2-4 FT ARE EXPECTED SUNDAY WITH A NE WIND CHOP PREDOMINANT WITHIN THE WAVE SPECTRUM. WAVE HEIGHTS FALL TO 2-3 FT MONDAY AS THE WINDS EASE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...TRA/JDW NEAR TERM...REK/TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...SGL MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
250 AM EDT THU MAY 29 2014 .SYNOPSIS...A COLD FRONT WILL MOVE SOUTHWEST THROUGH CENTRAL NORTH CAROLINA TODAY...THEN STALL OUT SOUTH OF THE AREA ON FRIDAY. HIGH PRESSURE WILL EXTEND INTO THE REGION FROM THE NORTH OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 920 PM WEDNESDAY... PRIMARY CHANGE THIS EVENING IS A REORIENTATION OF PRECIP CHANCES ACROSS THE CWA TO INCREASE THEM ACROSS THE NORTHEAST QUARTER OF THE CWA AND DECREASE THEM ELSEWHERE. AS OF 9 PM THE BACKDOOR SURFACE FRONT EXTENDED FROM JUST SOUTH OF CHI ACROSS FAR NRN IN/OH AND SW PA/DC/DELMARVA. AS ONE MIGHT EXPECT WITHIN A REGIME OF MARGINAL TO MODERATE INSTABILITY AND VERY WEAK SHEAR... THE LATEST SURFACE ANALYSIS SHOWS NUMEROUS WEAK BOUNDARIES AND CONVECTIVE OUTFLOWS ACROSS THE REGION... THE MOST PROFOUND OF WHICH NOW STRETCHES FROM WEST CENTRAL VA SE TO SE VA AND NE NC WITH NUMEROUS SHOWERS AND STORMS AND THE ASSOCIATED COLD POOL PROPAGATING GENERALLY SOUTHWARD... OUT AHEAD OF THE SYNOPTIC FRONT. EARLIER HRRR RUNS TODAY HAVE NOT DONE VERY WELL BUT THE LATEST HRRR RUN APPEARS TO BE HANDLING THE ONGOING CONVECTION TO OUR NNE WELL... AND IT PROGRESSES THIS ACTIVITY SOUTHWARD AND SE OVER THE NORTHEAST CWA... IN LINE WITH EXTRAPOLATION OF EXISTING FEATURES. THE AIR MASS IN THIS REGION REMAINS MODERATELY UNSTABLE WITH MLCAPE VALUES OF 1500-2000 J/KG ACCORDING TO THE SPC MESOANALYSIS... AND WHILE CINH IS STARTING TO CREEP UP... LAPSE RATES REMAIN HIGH ENOUGH WITH REMAINING ELEVATED CAPE TO SUPPORT THE ONGOING CONVECTION AS IT TRANSLATES INTO THE CENTRAL NC. HAVE RAISED POPS TO SCATTERED FROM RALEIGH TO THE NORTH AND EAST... PUSHING SOUTHEAST THROUGH THE NIGHT... WITH ISOLATED POPS SURROUNDING THIS AREA... AND LITTLE TO NO POP OVER THE WRN AND SW CWA. WITH A TREND TOWARD MOSTLY CLOUDY SKIES... EXPECT LOWS OF 66- 71. -GIH && .SHORT TERM /THURSDAY AND FRIDAY/... AS OF 245 PM WEDNESDAY... THE BACKDOOR COLD FRONT SLIDING TOWARD CENTRAL NC FROM THE NORTH WILL STALL OUT AROUND THE VA/NC BORDER. SURFACE CONVERGENCE BETWEEN THE HIGH TO THE NE AND LOW TO THE SW...AND THE RESULTANT MOISTURE AND TEMPERATURE BOUNDARIES...WILL RESULT IN INCREASED CHANCES FOR CONVECTION...ESPECIALLY ACROSS THE SOUTH WHERE THE BEST MOISTURE AND HIGHEST TEMPS ARE EXPECTED. THE BEST UPPER LEVEL FORCING WILL OCCUR AROUND/AFTER 00Z FRIDAY AS SHORTWAVE ENERGY MOVES AROUND THE BASE OF THE UPPER LEVEL TROUGH AND SWINGS THROUGH THE AREA. SHEAR AND INSTABILITY PARAMETERS ARE EXPECTED TO BE SIMILAR TO TUESDAY AND WEDNESDAY...WITH PWATS IN THE 1.50-1.75 INCH RANGE. THUS...AN ISOLATED SEVERE STORM OR TWO AND HEAVY RAIN CANNOT BE RULED OUT...WITH THE BEST CHANCES ACROSS THE SOUTH. THE FRONT WILL LINGER NEAR THE SOUTHERN PORTION OF THE FORECAST AREA ON FRIDAY...BEFORE BEING PUSHED EVEN FURTHER SOUTH OVER THE WEEKEND BY HIGH PRESSURE BUILDING DOWN OUT OF THE NORTHEAST. GOOD MOISTURE WILL REMAIN OVER THE AREA (PWAT VALUES NEAR 1.25-1.75 INCHES... HIGHEST ACROSS THE SOUTH) BEFORE DRIER AIR FILTERS IN LATE FRIDAY INTO SATURDAY. AS A RESULT... DECENT PRECIP CHANCES WILL ONCE AGAIN OCCUR ACROSS THE AREA ON FRIDAY (HIGHEST ACROSS THE SOUTH IN THE VICINITY OF THE FRONT AND BEST DESTABILIZATION). TEMPS WILL GENERALLY BE IN THE UPPER 70S TO LOWER 80S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... AS OF 250 AM THURSDAY... MODEL CONSENSUS WOULD BRING CLEARING FROM NORTHEAST TO SOUTHWEST ACROSS CENTRAL NC FRIDAY NIGHT AND SATURDAY MORNING. THIS OCCURS AS DRIER AIR IS DRIVEN INTO THE REGION COURTESY OF THE STRENGTHENING (1030+ MB) SURFACE HIGH PRESSURE LOCATED TO OUR NORTH. HOWEVER... THERE SHOULD STILL BE ENOUGH OF AN EASTERLY UPSLOPE TYPE COMPONENT TO THE FLOW TO KEEP VARIABLY CLOUDY SKIES INTO SATURDAY OR SATURDAY NIGHT OVER PORTIONS OF THE WESTERN PIEDMONT. LITTLE IF ANY CHANCE OF SHOWERS IS NOTED IN THE LATEST MODEL RUNS PAST FRI EVENING. WE WILL MAINTAIN OUR ONGOING FORECAST OF MOSTLY SUNNY/MOSTLY CLEAR SAT- MON... EXCEPT VARIABLY CLOUDY FRI NIGHT AND SATURDAY FAR WESTERN PIEDMONT. LOWS IN THE 50S NE TO NEAR 60 SW SATURDAY AND SUNDAY. HIGHS GENERALLY 78-83. FOR MONDAY AND BEYOND... THERE IS STILL NOT MUCH OF AN INDICATION OF A WIDESPREAD SHOWER OR THUNDERSTORM THREAT THROUGH AT LEAST MIDWEEK. GRADUAL WARMING TO HOT BY WEDNESDAY AS HIGHS RETURN INTO THE 80S (SOME LOWER 90S BY WED). LOWS INCREASE INTO THE 60S. THE ONLY MENTION OF RAIN CHANCES WILL BE A SLIGHT CHANCE OF PM SHOWERS/STORMS WED. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 200 AM THURSDAY... 24-HR TAF PERIOD: VFR CONDITIONS WILL PREVAIL AT MOST TERMINALS THROUGH THE REMAINDER OF THE MORNING. IFR CEILINGS OBSERVED OVER SOUTHEAST VA AND NORTHEAST NC AT 06Z ARE EXPECTED TO MOVE SOUTHWEST INTO THE NORTHEAST COASTAL PLAIN BY ~12Z...AND WILL LIKELY AFFECT THE KRWI TERMINAL AROUND THAT TIME...SLOWLY LIFTING TO MVFR BY NOON. IT IS POSSIBLE THAT THE KRDU TERMINAL COULD SEE A PERIOD OF MVFR CEILINGS BETWEEN 12-16Z...THOUGH UNCERTAINTY IS SUFFICIENT ENOUGH TO PRECLUDE MENTION AT THIS TIME. OTHERWISE...EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO AFFECT THE INT/GSO/RDU/FAY TERMINALS THIS AFTERNOON AS A BACK DOOR COLD FRONT CONTINUES TO MOVE SOUTHWEST INTO CENTRAL NC. EXPECT IFR/LIFR CEILINGS TO DEVELOP ON THE COOL SIDE OF THE BACK DOOR FRONT BY THE END OF THE TAF PERIOD (TONIGHT) AT ALL TERMINALS. LOOKING AHEAD: SUB-VFR CEILINGS ARE LIKELY TO PERSIST IN MOST AREAS FRIDAY INTO FRIDAY NIGHT. EXPECT VFR CONDITIONS TO RETURN SAT-MON AS DRY HIGH PRESSURE EXTENDS INTO THE REGION FROM THE NORTH. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD SHORT TERM...KC LONG TERM...32 AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
216 AM EDT THU MAY 29 2014 .SYNOPSIS...A BACK DOOR COLD FRONT WILL MOVE SOUTHWEST THROUGH CENTRAL NORTH CAROLINA TODAY...THEN STALL OUT SOUTH OF THE AREA ON FRIDAY. HIGH PRESSURE WILL EXTEND INTO THE REGION FROM THE NORTH OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 920 PM WEDNESDAY... PRIMARY CHANGE THIS EVENING IS A REORIENTATION OF PRECIP CHANCES ACROSS THE CWA TO INCREASE THEM ACROSS THE NORTHEAST QUARTER OF THE CWA AND DECREASE THEM ELSEWHERE. AS OF 9 PM THE BACKDOOR SURFACE FRONT EXTENDED FROM JUST SOUTH OF CHI ACROSS FAR NRN IN/OH AND SW PA/DC/DELMARVA. AS ONE MIGHT EXPECT WITHIN A REGIME OF MARGINAL TO MODERATE INSTABILITY AND VERY WEAK SHEAR... THE LATEST SURFACE ANALYSIS SHOWS NUMEROUS WEAK BOUNDARIES AND CONVECTIVE OUTFLOWS ACROSS THE REGION... THE MOST PROFOUND OF WHICH NOW STRETCHES FROM WEST CENTRAL VA SE TO SE VA AND NE NC WITH NUMEROUS SHOWERS AND STORMS AND THE ASSOCIATED COLD POOL PROPAGATING GENERALLY SOUTHWARD... OUT AHEAD OF THE SYNOPTIC FRONT. EARLIER HRRR RUNS TODAY HAVE NOT DONE VERY WELL BUT THE LATEST HRRR RUN APPEARS TO BE HANDLING THE ONGOING CONVECTION TO OUR NNE WELL... AND IT PROGRESSES THIS ACTIVITY SOUTHWARD AND SE OVER THE NORTHEAST CWA... IN LINE WITH EXTRAPOLATION OF EXISTING FEATURES. THE AIR MASS IN THIS REGION REMAINS MODERATELY UNSTABLE WITH MLCAPE VALUES OF 1500-2000 J/KG ACCORDING TO THE SPC MESOANALYSIS... AND WHILE CINH IS STARTING TO CREEP UP... LAPSE RATES REMAIN HIGH ENOUGH WITH REMAINING ELEVATED CAPE TO SUPPORT THE ONGOING CONVECTION AS IT TRANSLATES INTO THE CENTRAL NC. HAVE RAISED POPS TO SCATTERED FROM RALEIGH TO THE NORTH AND EAST... PUSHING SOUTHEAST THROUGH THE NIGHT... WITH ISOLATED POPS SURROUNDING THIS AREA... AND LITTLE TO NO POP OVER THE WRN AND SW CWA. WITH A TREND TOWARD MOSTLY CLOUDY SKIES... EXPECT LOWS OF 66- 71. -GIH && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 245 PM WEDNESDAY... THE BACKDOOR COLD FRONT SLIDING TOWARD CENTRAL NC FROM THE NORTH WILL STALL OUT AROUND THE VA/NC BORDER. SURFACE CONVERGENCE BETWEEN THE HIGH TO THE NE AND LOW TO THE SW...AND THE RESULTANT MOISTURE AND TEMPERATURE BOUNDARIES...WILL RESULT IN INCREASED CHANCES FOR CONVECTION...ESPECIALLY ACROSS THE SOUTH WHERE THE BEST MOISTURE AND HIGHEST TEMPS ARE EXPECTED. THE BEST UPPER LEVEL FORCING WILL OCCUR AROUND/AFTER 00Z FRIDAY AS SHORTWAVE ENERGY MOVES AROUND THE BASE OF THE UPPER LEVEL TROUGH AND SWINGS THROUGH THE AREA. SHEAR AND INSTABILITY PARAMETERS ARE EXPECTED TO BE SIMILAR TO TUESDAY AND WEDNESDAY...WITH PWATS IN THE 1.50-1.75 INCH RANGE. THUS...AN ISOLATED SEVERE STORM OR TWO AND HEAVY RAIN CANNOT BE RULED OUT...WITH THE BEST CHANCES ACROSS THE SOUTH. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 245 PM WEDNESDAY... THE FRONT WILL LINGER NEAR THE SOUTHERN PORTION OF THE FORECAST AREA ON FRIDAY...BEFORE BEING PUSHED EVEN FURTHER SOUTH OVER THE WEEKEND BY HIGH PRESSURE BUILDING DOWN OUT OF THE NORTHEAST. GOOD MOISTURE WILL REMAIN OVER THE AREA (PWAT VALUES NEAR 1.25-1.75 INCHES... HIGHEST ACROSS THE SOUTH) BEFORE DRIER AIR FILTERS IN LATE FRIDAY INTO SATURDAY. AS A RESULT... DECENT PRECIP CHANCES WILL ONCE AGAIN OCCUR ACROSS THE AREA ON FRIDAY (HIGHEST ACROSS THE SOUTH IN THE VICINITY OF THE FRONT AND BEST DESTABILIZATION). TEMPS WILL GENERALLY BE IN THE UPPER 70S TO LOWER 80S. THEN...FAIRLY STRONG HIGH PRESSURE (~1025 MB) WILL BUILD DOWN THE EAST COAST OVER THE WEEKEND...PUSHING THE BOUNDARY EVEN FURTHER SOUTH. THIS WILL VIRTUALLY BRING AN END TO OUR PRECIP CHANCES AS STABLE NORTHEASTERLY FLOW DOMINATES. HIGH PRESSURE WILL THEN DOMINATE THROUGH EARLY NEXT WEEK...SHIFTING OFFSHORE BY TUESDAY. THEREFORE...AM EXPECTING THE AREA TO BE MOSTLY DRY...WITH MAYBE SOME DIURNAL TYPE PRECIP RETURNING TUESDAY INTO WEDNESDAY AS MOISTURE GRADUALLY INCREASES IN THE INCREASING RETURN FLOW...ESPECIALLY ACROSS THE WESTERN PORTIONS OF THE FORECAST AREA. TEMPS WILL BE SLIGHTLY BELOW NORMAL FOR THE WEEKEND...BEFORE GRADUALLY MODERATING NEXT WEEK TO BACK TO ABOVE NORMAL BY TUESDAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 200 AM THURSDAY... 24-HR TAF PERIOD: VFR CONDITIONS WILL PREVAIL AT MOST TERMINALS THROUGH THE REMAINDER OF THE MORNING. IFR CEILINGS OBSERVED OVER SOUTHEAST VA AND NORTHEAST NC AT 06Z ARE EXPECTED TO MOVE SOUTHWEST INTO THE NORTHEAST COASTAL PLAIN BY ~12Z...AND WILL LIKELY AFFECT THE KRWI TERMINAL AROUND THAT TIME...SLOWLY LIFTING TO MVFR BY NOON. IT IS POSSIBLE THAT THE KRDU TERMINAL COULD SEE A PERIOD OF MVFR CEILINGS BETWEEN 12-16Z...THOUGH UNCERTAINTY IS SUFFICIENT ENOUGH TO PRECLUDE MENTION AT THIS TIME. OTHERWISE...EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO AFFECT THE INT/GSO/RDU/FAY TERMINALS THIS AFTERNOON AS A BACK DOOR COLD FRONT CONTINUES TO MOVE SOUTHWEST INTO CENTRAL NC. EXPECT IFR/LIFR CEILINGS TO DEVELOP ON THE COOL SIDE OF THE BACK DOOR FRONT BY THE END OF THE TAF PERIOD (TONIGHT) AT ALL TERMINALS. LOOKING AHEAD: SUB-VFR CEILINGS ARE LIKELY TO PERSIST IN MOST AREAS FRIDAY INTO FRIDAY NIGHT. EXPECT VFR CONDITIONS TO RETURN SAT-MON AS DRY HIGH PRESSURE EXTENDS INTO THE REGION FROM THE NORTH. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD SHORT TERM...KC LONG TERM...KRD AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1220 AM CDT THU MAY 29 2014 .UPDATE... ISSUED AT 1220 AM CDT THU MAY 29 2014 MAIN ADJUSTMENT TO THE FORECAST WAS TO REMOVE THE SEVERE THUNDERSTORM WORDING FOR TONIGHT IN THE WEST. AREA RADARS HAVE SHOWN A DECREASING TREND IN THE STORM INTENSITY AS THE CONVECTION MOVES INTO WESTERN NORTH DAKOTA. THE LATEST SHORT TERM MODELS SUGGEST THE CONVECTION WILL LIKELY PERSIST FOR ANOTHER SEVERAL HOURS...BUT SHOULD GRADUALLY WANE LATER THIS MORNING. UPDATE ISSUED AT 1002 CDT WED MAY 28 2014 QUICK UPDATE AGAIN TO BETTER REFLECT LIGHT RAIN ACROSS FAR WEST...WHERE POPS WERE TOO LOW. MAINTAINED CONVECTIVE CHANCES AS PREVIOUSLY SHOWN AND CONTINUING TO WATCH CONVECTION IN EAST CENTRAL MT WHICH HAS STRENGTHENED IN PAST HALF HOUR. UPDATE ISSUED AT 943 PM CDT WED MAY 28 2014 MAIN CHANGES WERE ADJUSTMENTS TO POPS. AS MENTIONED IN SPC MCD ISSUED A FEW MINUTES AGO CONVECTION ACROSS EAST CENTRAL MONTANA IS LESS ORGANIZED THAN THE CLUSTER OF STORMS ACROSS NORTH CENTRAL MONTANA. HI RES MODELS CONTINUE TO HAVE CHALLENGES WITH ONGOING CONVECTION. HRRR INITIALIZED WELL WITH 01Z RUN...BUT APPEARS TO OVERDUE EXPANSION OF CONVECTION IN SUBSEQUENT HOURS. RAP TIMING APPEARS TO BE SLOWER AND MORE ACCURATE. BOTH MODELS HINT AT STRONGER CLUSTER IN NORTH CENTRAL MONTANA MOVING NORTHEAST INTO CANADA. GIVEN THESE TRENDS...HAVE LOWERED POPS NEXT COUPLE HOURS AND MAINTAINED BEST CHANCE ACROSS NORTHWEST ND. DID INTRODUCE SOME POPS ACROSS SOUTHWEST BASED ON WEAK RETURNS APPROACHING ON BOWMAN RADAR. UPDATE ISSUED AT 713 PM CDT WED MAY 28 2014 MAIN UPDATE CONCERN IS CONVECTIVE POTENTIAL TONIGHT. CURRENTLY MOST OF MONTANA IS IN A SEVERE THUNDERSTORM WATCH. RADAR MOSAIC SHOWS THUNDERSTORMS STILL WELL WEST OF NORTH DAKOTA. ATMOSPHERE STILL WELL CAPPED AND HI-RES MODELS /RAP AND HRRR/ ARE TOO FAR EAST WITH CONVECTION COMPARED TO CURRENT RADAR. HAVE TRIMMED BACK POPS FOR EARLY EVENING AND WILL CONTINUE TO MONITOR TRENDS FOR NEXT UPDATE. LATEST BUFR SOUNDINGS FOR KISN ALSO SHOW SUBSTANTIAL CAP IN PLACE THROUGH THE EVENING. 18Z NAM KEEPS CWA DRY OVERNIGHT WHILE GFS SPREADS SOME SHOWERS/THUNDERSTORMS INTO THE WEST BY 06Z. ALSO UPDATED HOURLY GRIDS TO ACCOUNT FOR LESS CLOUD COVER AND SLIGHT TEMP ADJUSTMENTS FOR WEST WHICH WAS RUNNING SLIGHTLY COOLER THAN NORMAL AND THE EAST WHICH WAS A LITTLE WARMER THAN CURRENT FORECAST. && .SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY) ISSUED AT 321 PM CDT WED MAY 28 2014 THE MAIN CHALLENGE FOR THE PERIOD WILL BE DETERMINING THE SEVERE POTENTIAL OVER EXTREME NORTHWESTERN NORTH DAKOTA TONIGHT...AND AGAIN OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA LATE THURSDAY AFTERNOON. MSAS ANALYSIS INDICATES A SURFACE LOW DEEPENING OVER CENTRAL MONTANA THIS AFTERNOON...WHICH IS SERVING TO INCREASE THE LOW-LEVEL JET OVER WESTERN NORTH DAKOTA. THE INCREASING LOW-LEVEL MOISTURE FEED IS INCREASING SURFACE-BASED CAPE OVER SOUTHWESTERN NORTH DAKOTA/EASTERN MONTANA THIS AFTERNOON. HOWEVER...CONVECTION IS HAVING A DIFFICULT TIME INITIATING AS MUCH COOLER BOUNDARY LAYER TEMPERATURES IN THE WAKE OF AN MCV HAS GENERATED VERY WEAK LOW-LEVEL LAPSE RATES (0-3 KM LAPSE RATES AROUND 6 C/KM OVER WESTERN NORTH DAKOTA PER SPC ANALYSIS). RAPID DESTABILIZATION WILL NEED TO OCCUR TO GET CONVECTION TO DEVELOP ALONG THE SURFACE TROUGH SETTING UP OVER CENTRAL MONTANA LATER THIS AFTERNOON AND EARLY EVENING. FURTHER COMPLICATING THE CONVECTIVE POTENTIAL IS A STRENGTHENING CAP OVER WESTERN NORTH DAKOTA AHEAD OF THE DEEPENING LOW. MODELS CONTINUE TO PROG CIN GREATER THAN 500 J/KG DEVELOPING OVER WESTERN NORTH DAKOTA AFTER SUNSET AND CONTINUING OVERNIGHT. WITH THAT BEING SAID...THE GREATEST DYNAMICS/SURFACE FORCING IS PROGGED TO SET UP OVER SOUTH CENTRAL SASKATCHEWAN EARLY THIS EVENING. IF SAID CONVECTION DEVELOPS...IT COULD DEVELOP ITS OWN COLD POOL AND ADVECT INTO THE EXTREME NORTHWESTERN PORTIONS OF NORTH DAKOTA. AS A RESULT...INCLUDED A SEVERE MENTION IN THE FORECAST FOR THE NORTHWESTERN COUNTIES BETWEEN 00Z-06Z TONIGHT...CONSISTENT WITH SPC`S DAY 1 OUTLOOK. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. ISOLATED TORNADOES WILL ALSO BE POSSIBLE. THIS ACTIVITY IS PROGGED TO WANE AFTER MIDNIGHT AS THE BOUNDARY LAYER STABILIZES. DRY CONDITIONS ARE FORECAST TO CONTINUE AREAWIDE THROUGH LATE THURSDAY MORNING. BY THURSDAY AFTERNOON...A SURFACE TROUGH IS PROGGED TO STALL ACROSS WESTERN NORTH DAKOTA. ENHANCED SURFACE MOISTURE CONVERGENCE ALONG THE BOUNDARY COMBINED WITH MUCAPE VALUES BETWEEN 1500-2000 J/KG...AND 0-6KM SHEAR AROUND 35 KNOTS WILL LIKELY PRODUCE A LINE OF THUNDERSTORMS EXTENDING FROM NORTH CENTRAL NORTH DAKOTA INTO SOUTHWESTERN NORTH DAKOTA. THIS LINE COULD DEVELOP INTO A SQUALL LINE WITH HEAVY RAINFALL AND DAMAGING WINDS BEING THE PRIMARY THREATS. WILL HIGHLIGHT THIS POTENTIAL IN THE HWO FOR NOW. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 321 PM CDT WED MAY 28 2014 VERY ACTIVE WEATHER PATTERN THROUGH EARLY NEXT WEEK. FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD WILL BE CHANCES FOR STRONG TO SEVERE THUNDERSTORMS AND VERY HEAVY RAINFALL THURSDAY NIGHT THROUGH FRIDAY NIGHT...CONTINUED CHANCES FOR HEAVY RAIN OVER THE WEEKEND AND INTO EARLY PORTIONS OF NEXT WEEK...ALONG WITH COOLER TEMPERATURES OVER MUCH OF THE PERIOD. SFC TROUGH MOVES SLOWLY EAST ACROSS WESTERN INTO CENTRAL NORTH DAKOTA THURSDAY NIGHT...AND WILL BE THE FOCUS FOR DIURNALLY DRIVEN THUNDERSTORMS...SOME POTENTIALLY SEVERE GIVEN THE INSTABILITY AND FORCING ADVERTISED. MODELS STILL PORTRAY STRONG MOISTURE TRANSPORT AHEAD OF THE SFC TROUGH POOLING ALONG THE BOUNDARY...INCREASING THE POTENTIAL FOR HEAVY RAIN. PW VALUES ARE PROJECTED TO NEAR THE 99TH PERCENTILE SO PLENTY OF MOISTURE TO WORK WITH GENERATING WIDESPREAD 1-2 INCH RAINFALL. LOCALLY HIGHER AMOUNTS WITH HEAVIER THUNDERSTORMS WILL BE VERY LIKELY. SFC TROUGH SLOWLY MOVES EAST FRIDAY...BECOMING QUASI-STATIONARY OVER THE SOUTH CENTRAL EAST INTO THE JAMES AND RED RIVER VALLEY REGIONS. THUS ANOTHER ROUND OF STRONG TO SEVERE STORMS WITH HEAVY RAIN LIKELY ALONG TO AHEAD OF THE SFC BOUNDARY. WILL MAINTAIN A DRY FORECAST ACROSS THE NORTHWEST QUARTER OF ND FRIDAY WITH HIGH PRESSURE AND A STABLE AIRMASS DEVELOPING SOUTH AND EAST FROM CANADA IN THE WAKE OF THE TROUGH. COOLER TEMPERATURES AND MORE STABLE CONDITIONS ARE STILL FORECAST BY BOTH THE 12Z GFS/ECMWF SATURDAY THROUGH MONDAY WITH A COOL NORTHEAST/EASTERLY FLOW DEVELOPING WITH HIGH PRESSURE OVER SOUTH CENTRAL CANADA AND SURFACE LOW PRESSURE DEVELOPING FROM THE HIGH PLAINS OF WYOMING EASTERLY INTO NEBRASKA/SOUTH DAKOTA. IDEAL PLACEMENT FOR STRONG OVERRUNNING FLOW ACROSS NORTH DAKOTA...SETTING US UP FOR A PROLONGED PERIOD OF MODERATE TO HEAVY PRECIPITATION. WHILE THE MORE STABLE CONDITIONS RESULTS IN MINIMAL CHANCES FOR SEVERE WEATHER...SOME GUIDANCE DOES TRY TO CREEP MARGINAL INSTABILITY ACROSS MY FAR SOUTH SO WILL NOT COMPLETELY RULE THIS OUT. HEAVY RAIN WILL BE THE MAIN IMPACT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1220 AM CDT THU MAY 29 2014 BREEZY SOUTHEASTERLY WINDS WILL CONTINUE OVERNIGHT INTO THURSDAY AS A STORM SYSTEM TRACKS FROM MONTANA NORTHEASTWARD TO CANADA. SOME SHOWERS/THUNDERSTORMS ARE POSSIBLE ACROSS THE WEST /KISN/ OVER THE NEXT COUPLE OF HOURS. SO FAR...MOST LIGHTNING STRIKES HAVE STAYED WEST OF KISN...SO WILL GO WITH SHOWERS FOR NOW AND UPDATE TO ADD THUNDERSTORMS IF NECESSARY. A COLD FRONT SLOWLY MOVES INTO WESTERN NORTH DAKOTA BY THURSDAY AFTERNOON WITH WINDS SHIFTING TO THE WEST/NORTHWEST BEHIND IT. SHOWERS/THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT...POSSIBLY AFFECTING KMOT/KDIK LATE AFTERNOON. WILL KEEP THE MENTION OF PRECIPITATION OUT OF KISN FOR NOW SINCE IT APPEARS MOST OF THE ACTIVITY MAY STAY JUST EAST. DID INTRODUCE A PROB30 GROUP FOR KMOT/KDIK AS THE CHANCES FOR CONVECTION INCREASE THURSDAY EVENING. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CK SHORT TERM...TM LONG TERM...NH AVIATION...CK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1023 PM EDT FRI MAY 30 2014 .SYNOPSIS... A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE NORTHEAST THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHEAST LATE IN THE WEEKEND. THIS HIGH PRESSURE MOVE OFFSHORE BY MIDWEEK...WHILE MOISTURE INCREASES OVER OUR AREA FROM THE WEST. && .NEAR TERM /THROUGH SATURDAY/... 1015 PM UPDATE...CONVECTION HAS STEADILY WANED ACRS THE FA EXCEPT FOR A CLUSTER OF CELLS WHICH HAVE CONTINUED TO BUBBLE ALONG A LINE FROM THE NW CORNER OF NC SEWD INTO THE PIEDMONT TRIAD. THIS SEEMS TO BE THE FRONT...PER SFC OBS AND MSLP ANALYSIS. WHILE COVERAGE REMAINS RATHER STEADY WITHIN THE CLUSTER...EACH NEW GENERATION APPEARS TO BE WEAKER THAN THE LAST. HRRR NOW REDEVELOPS ACTIVITY OVER THE I-77 CORRIDOR OVERNIGHT WHILE THE NEW RUN JUST COMPLETED OF OUR LOCAL WRF-ARW DROPS ACTIVITY STEADILY SWD THRU THE ERN HALF OF THE FA OVERNIGHT AND INTO TMRW MRNG. THESE SCENARIOS ARE PLAUSIBLE THOUGH I WONDER HOW MUCH INSTABILITY IS REALLY LEFT GIVEN ALL THE ACTIVITY EARLIER. I HAVE MAINTAINED THE SCHC OVERNIGHT THROUGHOUT THE AREA. AS OF 230 PM FRI...ONE IS HARD-PRESSED TO IDENTIFY THE REMAINS OF A SURFACE BOUNDARY THAT SHOULD BE STRUNG OUT NW TO SE ACROSS THE WESTERN CAROLINAS...SUCH THAT IT IS HARD TO SAY IF THIS FEATURE WILL EVEN PLAY ANY ROLE IN ORGANIZING ANY ELEVATED CONVECTION OVERNIGHT. OVER THE NEXT 24 HOURS...SUBTLE CHANGES ARE NOTED AT MID AND UPPER LEVELS...WHILE THE PATTERN DOES NOT CHANGE SUBSTANTIALLY. THE MODELS WANT TO KEEP SOME COVERAGE PARTICULARLY NEAR THE BLUE RIDGE OWING TO A WEAK UPSLOPE FLOW AT LOW LEVELS...SO THE FCST RETAINS AT LEAST A SLIGHT CHANCE IN THE SOUTHEASTERLY UPSLOPE FAVORED AREAS THROUGH SATURDAY MORNING. THE MODELS DO A MORE CONCERTED EFFORT IN IDENTIFYING A SW TO NE GRADIENT OF MOISTURE ACROSS THE FCST AREA ON SATURDAY THAT REPRESENTS WHAT IS LEFT OF THE FRONT. THAT SHOULD LEAD TO SOME IDENTIFIABLE DIFFERENCES IN THE WEATHER BETWEEN NE GEORGIA AND WESTERN SC...WHICH SHOULD HAVE ANOTHER DAY MUCH LIKE TODAY...TO THE WESTERN PIEDMONT OF NC WHICH SHOULD HAVE A STRONGER NE WIND ADVECTING COOLER AND DRIER AIR THAT WILL GREATLY INHIBIT CONVECTION AND KEEP TEMPS BELOW NORMAL. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AT 230 PM EDT FRIDAY...ON SATURDAY EVENING AN UPPER RIDGE WILL EXTEND FROM GA AND THE CAROLINAS...TO THE GREAT LAKES...WHILE AN UPPER LOW WILL BE OVER SE TX...AND A MUCH DEEPER UPPER LOW WILL BE WELL OFF THE NEW ENGLAND COAST. THE UPPER RIDGE PROGRESSES VERY SLOWLY TO THE EAST COAST BY MONDAY...WHILE THE UPPER LOW OVER TX FILLS...AND THE ATLANTIC UPPER LOW REMAINS NEARLY STATIONARY. A SLOW MOVING COLD FRONT WILL MOVE ACROSS THE SAVANNAH RIVER VALLEY SATURDAY NIGHT...WITH SUBSTANTIAL MOISTURE BEHIND IT. AN EASTERLY LOW LEVEL FLOW COMPONENT IN THE WAKE OF THE FRONT WILL KEEP MOIST UPSLOPE LIFT OVER THE SOUTHERN BLUE RIDGE...SUPPORTING CONTINUING PRECIPITATION THERE....WHILE LINGERING INSTABILITY ALONG THE BOUNDARY ITSELF SUPPORTS PRECIPIATION IN THE SAVANNAH RIVER VALLEY. THE FRONT MOVES FARTHER INTO GA ON SUNDAY...HIGH PRESSURE ALONG THE EASTERN SEABOARD WILL PUSH DRIER AIR SOUTHWEST INTO THE PIEDMONT OF THE CAROLINAS. LINGERING MOISTURE WILL STILL SUPPORT CLOUD COVER AND PRECIPITATION IN THE SAVANNAH RIVER VALLEY AND OVER THE MUCH OF THE MOUNTAINS...THOUGH INSTABILITY WILL BE MUCH LESS WITH COOLER SURFACE AIR MOVING IN. MOISTURE STARTS TO SPREAD EAST AGAIN ON SUNDAY NIGHT AND MONDAY AS SURFACE HIGH PRESSURE MOVES FROM THE EASTERN SEABOARD TO OFF THE CAROLINA COAST...ALLOWING WARM MOIST ADVECTION FORM THE GULF TO REACH NE GA AND THE WESTERN CAROLINAS. POPS WILL BE ALLOWED TO SPREAD EAST AS A RESULT...AND INCREASING INSTABILITY WILL BE MORE SUPPORTIVE OF CONVECTION ON MONDAY. TEMPERATURES WILL TREND DOWNWARD AS THE COOLER AIR MASS SETTLE IN...UNTIL MONDAY...WHEN WARM ADVECTION ENSUES IN SOUTHERLY FLOW ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AT 230 PM EDT FRIDAY...THE EXTENDED FORECAST WILL FEATURE A DEAMPLIFIED PATTERN...WITH A FLAT UPPER RIDGE OVER THE SOUTHEAST... AND MOORE OR LESS ZONAL FLOW TO THE NORTH. WEAK HIGH PRESSURE WILL BE CENTERED OFF THE CAROLINA COAST ON TUESDAY...WHILE THE REMNANTS OF A COLD FRONT CROSS THE APPALACHIANS FROM THE WEST. RESIDUAL MOISTURE ASSOCIATED WITH A FRONTOLYTIC ZONE OVER THE SOUTHERN APPALACHIANS WILL SUPPORT PRECIPITATION LONG BEFORE THE FRONT ARRIVES. THE SLOW MOVING BOUNDARY LEAVES THE AREA BY EARLY WEDNESDAY...HOWEVER DRYING BEHIND IT IS SOMEWHAT LIMITED...AND MODEL SOUNDINGS SHOW INSTABILITY AND LOW LEVEL MOISTER PERSISTING IN SUBSEQUENT DAYS. TEMPERATURES WILL RUN NEAR MID SUMMER NORMALS. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... AT KCLT...TSTM THREAT THIS EVENING IS TOO LOW TO MENTION IN THE TAF...BUT A LEFTOVER OUTFLOW BOUNDARY DOES LIE VERY NEAR THE FIELD ATTM AND A COUPLE OF BRIEF CELLS REGENERATING ALONG IT IS NOT OUT OF THE QUESTION. ALSO...SEVERAL GUID MEMBERS DEVELOP SOME SHRA/TSRA N OF THE FIELD IN THE WEE HRS SAT MRNG AS COLD ADVECTION BEHIND THE BACKDOOR FRONT AMPLIFIES AND TAPS INTO REMAINING ELEVATED INSTABILITY. THIS CHANCE IS LIKEWISE TOO LOW TO MENTION. SAID FRONT LOOKS LIKELY TO BRING LOW MVFR CIGS TO THE FIELD BEFORE MIDNIGHT...THIS BEING SUPPORTED BY MOST GUIDANCE. SOME FOG POSSIBLE THOUGH THE DRY WEATHER TODAY SUGGESTS IT IS NOT LIKELY TO BE SIGNIFICANT. SLOW IMPROVEMENT TO VFR THRU THE MRNG AS THE CIG MIXES AND LIFTS. WINDS PREVAIL NE. ELSEWHERE...LOW CIGS WILL SPREAD IN FROM THE EAST TONIGHT...MAKING IT AS FAR AS THE BLUE RIDGE. ALL THE SITES ARE EXPECTED TO DROP TO LOW MVFR OVERNIGHT PER GUID CONSENSUS. KHKY EXPECTED TO BRIEFLY GO IFR CIG ALSO. HVY RA OCCURRED THIS AFTN AT ALL TAF SITES AND THEREFORE FOG IS ANTICIPATED TO FORM. GUID SUGGESTS IFR LIKELY AT ALL EXCEPT KAND. THE CIGS/FOG WILL BE SLOW TO MIX OUT THRU THE MRNG BUT VFR WILL PREVAIL BY AFTN. PROB30S INCLUDED FOR SCT SHRA/TSRA NEAR THE BLUE RIDGE...WHICH IN THE ELY FLOW WILL LIKELY BE THE FOCUS FOR CONVECTION. OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH DAY... WITH MORNING RESTRICTIONS POSSIBLE. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-02Z KCLT MED 67% HIGH 93% HIGH 96% HIGH 100% KGSP HIGH 93% HIGH 80% HIGH 93% HIGH 95% KAVL HIGH 90% HIGH 84% HIGH 86% HIGH 97% KHKY HIGH 83% MED 77% MED 75% HIGH 100% KGMU MED 79% MED 77% HIGH 82% HIGH 93% KAND HIGH 89% MED 66% HIGH 83% HIGH 89% 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...JAT NEAR TERM...PM/WIMBERLEY SHORT TERM...JAT LONG TERM...JAT AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
446 PM EDT THU MAY 29 2014 .SYNOPSIS... A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE NORTHEAST THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHEAST THIS WEEKEND...AND MOVE OFFSHORE EARLY NEXT WEEK. && .NEAR TERM /THROUGH FRIDAY/... 430 PM UPDATE...FOR THE REMAINDER OF THE AFTERNOON...CONVECTION SHOULD CONTINUE TO BLOSSOM. CURRENT ACTIVITY IS MAINLY IN CLUSTERS ALONG OLD OUTFLOW BOUNDARIES...PARTICULARLY ONE LINEAR CLUSTER HAVING PROPAGATED IN THIS WAY OVER THE TUGALOO/SAVANNAH RIVERS. ANOTHER CLUSTER IS DEVELOPING ALONG THE BACKDOOR FRONT JUST NE OF CHARLOTTE. IN GENERAL THE LATEST HRRR SEEMS TO BE DOING A REASONABLY GOOD JOB AND ALLOWS THE CURRENT ACTIVITY TO DIE DOWN DIURNALLY OVER THE WRN HALF OF THE FA...BUT INCREASING COVERAGE OVER THE NC PIEDMONT ALONG THE FRONT. HAVE MAINTAINED THIS IN THE FCST. STEERING FLOW IS RATHER WEAK...SO STORMS WILL MOVE ONLY SLOWLY. FLASH FLOODING COULD BE AN ISSUE WITH THE SLOW MOVEMENT OF THE STORMS AND THE RELATIVELY DEEP MOISTURE. WE MAY SEE A FEW PULSE-TYPE SEVERE THUNDERSTORMS AS BUOYANCY LOOKS SUFFICIENT AND GENERALLY CLIMBING UP ABOVE 2000 J/KG...AND DCAPE HAS NOW BECOME INTERESTING /600-900 J/ SOUTH OF THE SRN NC BORDER. OVER THE NEXT 24 HOURS...THE MAIN CONCERN WILL BE THE FRONTAL ZONE DROPPING DOWN FROM THE NORTH. A SURFACE REFLECTION ALREADY SHOWS IN THE CAPE ANALYSIS NUDGING INTO THE NW PIEDMONT...WITH LOW CLOUDINESS AND STABLE AIR IN N CENTRAL NC. A SHORT WAVE DROPPING DOWN INTO THE UPPER TROF OFF THE EAST COAST WILL CONTINUE TO DRIVE THIS BOUNDARY FARTHER SOUTH AND EAST THIS EVENING. THE MODELS DO NOT REALLY SHOW MUCH IN THE WAY OF LOW LEVEL FORCING BUT THIS COULD BE MASKED BY THE DIURNAL CONVERGENCE TOWARD THE MTNS. IT STANDS TO REASON THAT THE BOUNDARY MAY PROVIDE THE FOCUS FOR CONVECTION WELL INTO THE NIGHTTIME HOURS. THERE IS SOME CONCERN FOR FLASH FLOOD POTENTIAL OVER THE NC BLUE RIDGE AND FOOTHILLS IF THE BOUNDARY MOVES FAR ENOUGH SOUTH TO DEVELOP A LOW LEVEL EASTERLY FLOW THAT COULD ANCHOR STORMS NEAR THE BLUE RIDGE...BUT NOT ENOUGH CONCERN TO ENTERTAIN A WATCH. EXPECT A DIURNAL REDUCTION IN STORM COVERAGE AFTER MIDNIGHT IN SPITE OF THE BOUNDARY...SO SOME OF THE LATEST SREF WAS BLENDED INTO THE POP. ON FRIDAY...SHOWERS AND STORMS SHOULD DEVELOP YET AGAIN ACROSS THE ENTIRE FCST AREA...BUT WE MIGHT BE COVERED WITH A LOW CLOUD CEILING BANKED UP AGAINST THE BLUE RIDGE THAT WILL CUT DOWN ON THE POTENTIAL FOR SEVERE STORMS. TEMPS SHOULD BE A BIT COOLER WITH THE ADDITIONAL CLOUD COVER AND EASTERLY FLOW DEVELOPING. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... AT 215 PM EDT THURSDAY...ON FRIDAY NIGHT AN UPPER RIDGE OVER THE NORTHERN PLAINS WILL MOVE SOUTHEAST BETWEEN A CLOSED LOW OVER LA AND AND UPPER TROUGH OFF THE EAST COAST...REACHING THE SOUTHERN APPALACHIANS. THE RIDGE CENTER WILL MOVE OVER THE OH RIVER VALLEY ON SATURDAY...AND OVER GA ON SUNDAY. A BACK DOOR COLD FRONT WILL DRIFT VERY SLOWLY SOUTH ACROSS SC ON FRIDAY NIGHT...AND ACROSS THE SAVANNAH RIVER VALLEY ON SATURDAY. MODEL SOUNDINGS SHOW ELEVATED INSTABILITY VERY SLOWLY DECREASING ALONG THE BOUNDARY ON FRIDAY NIGHT...AND INCREASING AGAIN ON SATURDAY...MAINTAINING A THREAT OF CONVECTION AND HEAVY RAINFALL. ON SATURDAY NIGHT THE FRONT MOVES SOUTHWEST OF OUR AREA...BUT LINGERING LOW LEVEL MOISTURE AND AN EASTERLY UPSLOPE COMPONENT WILL SUPPORT A CHANCE PRECIPITATION ALONG THE SOUTHERN BLUE RIDGE ESCARPMENT. DRIER AIR WORKING INTO THE AREA FROM THE NW ON SUNDAY WILL REDUCE THE CHANCE OF PRECIPITATION...BUT THE MODEL SUGGEST THAT MOISTURE BANKED UP AGAINST THE SOUTHERN BLUE RIDGE WILL PERSIST...AND SMALL POPS WILL BE CARRIED THERE AGAIN. TEMPERATURES WILL RUN ABOVE NORMAL WITH RISING HEIGHTS ALOFT...UNTIL COOLER AIR BEHIND THE FRONT WORKS INTO THE AREA ON SUNDAY. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AT 215 PM EDT THURSDAY...ON MONDAY AN UPPER RIDGE WILL EXTEND FROM FL TO THE EASTERN GREAT LAKES...WHILE A CLOSED UPPER LOW WILL BE OVER THE WESTERN ATLANTIC AND AN UPPER TROUGH WILL BE OVER THE WEST COAST. THE UPPER RIDGE PROGRESS TO THE EAST COAST BY TUESDAY...WHILE A SHORTWAVE MOVES ACROSS THE GREAT LAKES AREA. THE PATTERN DEAMPLIFIES BY WEDNESDAY...LEADING TO A LARGELY ZONAL FLOW ACROSS THE NATION...AND WEAK FLAT RIDGING OVER THE SOUTHEAST...A PATTERN THAT PERSISTS INTO THURSDAY. SURFACE HIGH PRESSURE WILL BE CENTERED NEAR THE COASTAL VA AND NC ON MONDAY...AND ALTHOUGH GULF INFLOW ON THE WEST SIDE OF THIS RIDGE WILL BE FOCUSED OVER THE MS...TN AND OH VALLEYS...THE MODELS INDICATE MOISTURE OVER THE SOUTHERN APPALACHIANS...WITH UPSLOPE FLOW AND INCREASING INSTABILITY SUPPORTING DIURNALLY DRIVEN CONVECTION. AS THE SURFACE HIGH DRIFTS SE AND OFFSHORE FROM TUESDAY THROUGH THURSDAY...GULF INFLOW WEAKENS...BUT SPREADS EAST...COVERING NE GA AND THE WESTERN CAROLINAS. UPSLOPE FLOW INTO ELEVATED TERRAIN WILL BE RATHER WEAK...BUT ENOUGH TO SUPPORT THE BEST CHANCES OF CONVECTION REMAINING ALONG THE BLUE RIDGE...EVEN AS CONVECTIVE CHANCES INCREASE TO THE EAST. TEMPERATURES WILL RISE FROM NEAR NORMAL VALUES...TO ABOVE NORMAL... EVEN AS HEIGHTS FALL ALOFT...AS COOL NE FLOW VEERS TO THE SW... AND WARM ADVECTION ENSUES. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... AT KCLT...FOR THE REST OF THE DAYLIGHT HOURS...VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORMS. CLOUD BASES SHOULD BE AROUND 045-050. KEPT THE LOW CLOUDS FEW OR SCT FOR THE INITIAL PERIOD BUT THERE COULD EASILY BE A TEMPORARY CEILING AT THAT LEVEL. THIS POSSIBILITY WAS LEFT OUT FOR BREVITY. THE CONVECTION ALLOWING MODELS ARE STILL GOING FOR A WINDOW OF THUNDERSTORM ACTIVITY DURING THE LATE AFTERNOON AND EARLY EVENING HOURS...SO THE TEMPO FOR THUNDERSTORMS WAS KEPT. THE STORMS COULD LINGER THROUGH THE EVENING AND EARLY MORNING HOURS AS A BACK DOOR COLD FRONT DROPS INTO THE REGION. INCLUDING A MENTION OF VCSH FOR NOW BUT EXPECT A TEMPO TO BE ADDED AGAIN AFTER THE FIRST TEMPO EXPIRES. FRONT WILL BRING AN MVFR CEILING INTO THE PIEDMONT FOR THE HOURS AROUND DAYBREAK. THE LOW CLOUD CEILING SHOULD LIFT AND SCATTER BY MID MORNING FRIDAY. SOME DETAIL WAS LEFT OUT OF THE TAF AFTER SUNRISE FRIDAY. ELSEWHERE...EXPECT MAINLY AFTN AND EVENING CONVECTION WILL FOCUS ALONG AN APPROACHING BACKDOOR COLD FRONT...WITH TSRA CHANCES HIGHER FROM KAVL TO KHKY THAN FARTHER S AT THE UPSTATE SC SITES. SHOWERS AND ISOLD TO SCT TSTMS MAY LINGER THROUGH THE NIGHT...ESPECIALLY NEAR THE ERN SLOPES OF THE MTNS FROM KAVL TO NEAR KGSP. SFC WINDS WILL ADJUST TO NRLY TO NELY WITH THE ARRIVAL OF THE FRONT TODAY AT THE NC SITES...WHILE CONTINUED SW FLOW IS LIKELY AT THE UPSTATE SITES BEFORE BECOMING LIGHT AND VARIABLE THIS EVENING. OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH DAY...WITH MORNING RESTRICTIONS POSSIBLE. CONFIDENCE TABLE... 20-02Z 02-08Z 08-14Z 14-20Z KCLT HIGH 100% HIGH 92% MED 64% HIGH 86% KGSP HIGH 100% HIGH 100% LOW 45% HIGH 91% KAVL HIGH 100% MED 71% HIGH 83% HIGH 86% KHKY HIGH 100% MED 77% MED 67% MED 68% KGMU HIGH 100% HIGH 100% LOW 56% HIGH 91% KAND HIGH 100% HIGH 94% HIGH 86% HIGH 91% 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...JAT NEAR TERM...PM/WIMBERLEY SHORT TERM...JAT LONG TERM...JAT AVIATION...PM/WIMBERLEY
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1226 PM CDT THU MAY 29 2014 .DISCUSSION... /ISSUED 1029 AM CDT THU MAY 29 2014/ UPDATE... AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO BRING NUMEROUS SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS TO THE MIDSOUTH TODAY. LATEST HRRR SHOWS A BAND MOVING NORTHWARD FROM CENTRAL MISSISSIPPI INTO NORTH MISSISSIPPI...THE MEMPHIS METRO AREA...AND EVENTUALLY SPREADING INTO NORTHEAST ARKANSAS BETWEEN 1-4 PM. WILL UPDATE TO EXPAND 80 POPS NORTHWARD TO COVER THIS AREA. WILL ALSO UPDATE TO LOWER TEMPS DUE TO CLOUD COVER AND SHOWER ACTIVITY. UPDATE WILL BE OUT SHORTLY. KRM DISCUSSION... /ISSUED 301 AM CDT THU MAY 29 2014/ CURRENT UPPER LOW WAS CENTERED OVER SOUTH CENTRAL ARKANSAS WITH MODELS SUGGESTING THIS AS ITS CLOSEST POSITION TO THE MIDSOUTH BEFORE SLOWLY DRIFTING SOUTHWESTWARD. ON THE SURFACE WINDS HAVE BACKED TO A MORE EASTERLY COMPONENT AS AN INDUCED SURFACE LOW HAS DEVELOPED IN THE SAME AREA. AS OF 3AM TEMPERATURES WERE BETWEEN 65F AND 70F...AND RADAR WAS SHOWING SCATTERED LIGHT SHOWERS DRIFTING NORTHWARD OVER THE SOUTHWEST DELTA COUNTIES. FOR TODAY AND TOMORROW...THE REGION WILL REMAIN INFLUENCED BY THE CLOSED LOW WITH SCATTERED TO NUMEROUS SHOWERS ANTICIPATED DURING THE HEAT OF THE DAY...AND LESS COVERAGE AT NIGHT. AGREED MODEL CONSISTENCY POINTS TO THE REGION SOUTH AND WEST OF MEMPHIS WITH THE GREATEST PROBABILITY OF PRECIPITATION...WHERE A WEAK INDUCED INVERTED SURFACE TROUGH WILL FORM. THE HIGHEST QPF AMOUNTS WILL BE OVER THIS AREA...WITH PERHAPS UP TO AN INCH AND HALF THROUGH FRIDAY AFTERNOON. SIGNIFICANT CLOUD COVER WILL KEEP TEMPERATURES BELOW NORMAL TODAY...AND CLOSER TO NORMAL TOMORROW. THIS...IN ADDITION TO THE ONGOING MOIST ADIABATIC LAPSE RATES OFF FORECAST SOUNDINGS SUGGESTS A REDUCTION IN THUNDERSTORM COVERAGE. A FEW MORE BREAKS IN THE CLOUD COVER IS ANTICIPATED TOMORROW...ESPECIALLY OVER THE NORTHERN HALF OF THE CWA AS THE LOW CENTER MOVES TO NEAR LAKE SABINE IN WESTERN LOUISIANA. THEREFORE THUNDERSTORM COVERAGE WILL REBOUND BACK...AND NORTH MISSISSIPPI WILL STILL RUN THE GREATEST RISK FOR RAIN. SATURDAY AND SUNDAY...NOT MUCH CHANGE WAS NEEDED WITH THE FORECAST THIS PERIOD...WITH ONLY A SLIGHT INCREASE IN POPS AND A DEGREE COOLER IN TEMPERATURES. THE REGION WILL REMAIN MOIST AS THE UPPER LOW OPENS AND A WEAK SHEAR AXIS HANGS ALONG THE MISSISSIPPI RIVER. LESS CLOUD COVER WILL ALLOW TEMPERATURES TO SHIFT BACK CLOSER TO 90F...WHICH MAY TRIGGER AN ISOLATED STRONG STORM DURING THE AFTERNOON HOURS. MONDAY THROUGH WEDNESDAY NIGHT...A SERIES OF WEAK SHORTWAVES WILL CROSS THE ROCKIES AND THE MIDWEST WITH THE MIDSOUTH SHIFTING FROM A LIGHT SOUTHEASTERLY/SOUTHERLY UPPER FLOW TO MORE WESTERLY. THE ECMWF IS A BIT MORE BULLISH WITH QPF AMOUNTS OVER THE AREA FROM FRONTAL MCS GENERATION IN THE MIDWEST...WHILE THE GFS KEEPS THE WEAK FRONT AND CONVECTIVE CONCENTRATION IN THE CORN BELT. FOR NOW HAVE KEPT RAIN CHANCES MORE CONSERVATIVE AND DIURNAL. TEMPERATURES NEXT WEEK WILL REMAIN NEAR 90F FOR HIGHS AND 70F FOR LOWS...WITH A SLIGHT SOUTHERLY BREEZE PROVIDING SOME RELIEF. JAB && .AVIATION... 18Z TAF CYCLE (29/18Z-30/18Z) AN UPPER LEVEL LOW PRESSURE SYSTEM OVER SOUTHERN AR WILL DRIFT SLOWLY TO THE SW INTO NW LA-ERN TX BY 30/18Z AND CONTINUE UNSETTLED WEATHER ACROSS THE MIDSOUTH THRU FRI. SCATTERED SHOWERS WILL CONTINUE TO OCCUR THRU THE PERIOD...WITH BEST CHANCES FOR TS IN THE AFTERNOON TO EARLY EVENING HOURS. DID TAKE VCSH OUT OF MKL/TUP LATER TONIGHT AS COVERAGE SHOULD DIMINISH SOME AS THE LOW MOVES FURTHER FROM THESE LOCATIONS. WINDS REMAIN ESE-SE THRU THE PERIOD...INCREASING SLIGHTLY DURING THE LATE MORNING TO AFTERNOON HOURS. CIGS GENERALLY EXPECTED TO INCREASE TO VFR BY EARLY-MID AFTERNOON WITH MVFR CIG/VIS STILL POSS IN AREAS OF SHRA/TS. CIGS EXPECTED TO AGAIN DECREASE BY MIDNIGHT OR SHORTLY THEREAFTER...WITH SOME PATCHY IFR POSS AT ALL LOCATIONS...BEST CHANCES BETWEEN 08-13Z. BROUGHT BACK MENTION OF VCTS TOMORROW AT 17Z CONTINUING DIURNAL TRENDS WITH THE UPPER-LEVEL SYSTEM TO THE SOUTHWEST. NGU && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1029 AM CDT THU MAY 29 2014 .UPDATE... AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO BRING NUMEROUS SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS TO THE MIDSOUTH TODAY. LATEST HRRR SHOWS A BAND MOVING NORTHWARD FROM CENTRAL MISSISSIPPI INTO NORTH MISSISSIPPI...THE MEMPHIS METRO AREA...AND EVENTUALLY SPREADING INTO NORTHEAST ARKANSAS BETWEEN 1-4 PM. WILL UPDATE TO EXPAND 80 POPS NORTHWARD TO COVER THIS AREA. WILL ALSO UPDATE TO LOWER TEMPS DUE TO CLOUD COVER AND SHOWER ACTIVITY. UPDATE WILL BE OUT SHORTLY. KRM && .DISCUSSION... /ISSUED 301 AM CDT THU MAY 29 2014/ CURRENT UPPER LOW WAS CENTERED OVER SOUTH CENTRAL ARKANSAS WITH MODELS SUGGESTING THIS AS ITS CLOSEST POSITION TO THE MIDSOUTH BEFORE SLOWLY DRIFTING SOUTHWESTWARD. ON THE SURFACE WINDS HAVE BACKED TO A MORE EASTERLY COMPONENT AS AN INDUCED SURFACE LOW HAS DEVELOPED IN THE SAME AREA. AS OF 3AM TEMPERATURES WERE BETWEEN 65F AND 70F...AND RADAR WAS SHOWING SCATTERED LIGHT SHOWERS DRIFTING NORTHWARD OVER THE SOUTHWEST DELTA COUNTIES. FOR TODAY AND TOMORROW...THE REGION WILL REMAIN INFLUENCED BY THE CLOSED LOW WITH SCATTERED TO NUMEROUS SHOWERS ANTICIPATED DURING THE HEAT OF THE DAY...AND LESS COVERAGE AT NIGHT. AGREED MODEL CONSISTENCY POINTS TO THE REGION SOUTH AND WEST OF MEMPHIS WITH THE GREATEST PROBABILITY OF PRECIPITATION...WHERE A WEAK INDUCED INVERTED SURFACE TROUGH WILL FORM. THE HIGHEST QPF AMOUNTS WILL BE OVER THIS AREA...WITH PERHAPS UP TO AN INCH AND HALF THROUGH FRIDAY AFTERNOON. SIGNIFICANT CLOUD COVER WILL KEEP TEMPERATURES BELOW NORMAL TODAY...AND CLOSER TO NORMAL TOMORROW. THIS...IN ADDITION TO THE ONGOING MOIST ADIABATIC LAPSE RATES OFF FORECAST SOUNDINGS SUGGESTS A REDUCTION IN THUNDERSTORM COVERAGE. A FEW MORE BREAKS IN THE CLOUD COVER IS ANTICIPATED TOMORROW...ESPECIALLY OVER THE NORTHERN HALF OF THE CWA AS THE LOW CENTER MOVES TO NEAR LAKE SABINE IN WESTERN LOUISIANA. THEREFORE THUNDERSTORM COVERAGE WILL REBOUND BACK...AND NORTH MISSISSIPPI WILL STILL RUN THE GREATEST RISK FOR RAIN. SATURDAY AND SUNDAY...NOT MUCH CHANGE WAS NEEDED WITH THE FORECAST THIS PERIOD...WITH ONLY A SLIGHT INCREASE IN POPS AND A DEGREE COOLER IN TEMPERATURES. THE REGION WILL REMAIN MOIST AS THE UPPER LOW OPENS AND A WEAK SHEAR AXIS HANGS ALONG THE MISSISSIPPI RIVER. LESS CLOUD COVER WILL ALLOW TEMPERATURES TO SHIFT BACK CLOSER TO 90F...WHICH MAY TRIGGER AN ISOLATED STRONG STORM DURING THE AFTERNOON HOURS. MONDAY THROUGH WEDNESDAY NIGHT...A SERIES OF WEAK SHORTWAVES WILL CROSS THE ROCKIES AND THE MIDWEST WITH THE MIDSOUTH SHIFTING FROM A LIGHT SOUTHEASTERLY/SOUTHERLY UPPER FLOW TO MORE WESTERLY. THE ECMWF IS A BIT MORE BULLISH WITH QPF AMOUNTS OVER THE AREA FROM FRONTAL MCS GENERATION IN THE MIDWEST...WHILE THE GFS KEEPS THE WEAK FRONT AND CONVECTIVE CONCENTRATION IN THE CORN BELT. FOR NOW HAVE KEPT RAIN CHANCES MORE CONSERVATIVE AND DIURNAL. TEMPERATURES NEXT WEEK WILL REMAIN NEAR 90F FOR HIGHS AND 70F FOR LOWS...WITH A SLIGHT SOUTHERLY BREEZE PROVIDING SOME RELIEF. JAB && .AVIATION... 12Z TAF CYCLE (29/12Z-30/12Z) AN UPPER LEVEL LOW PRESSURE SYSTEM ALONG THE ARKANSAS AND LOUISIANA BORDER WILL CONTINUE TO INFLUENCE MIDSOUTH WEATHER TODAY INTO TONIGHT. SCATTERED TO NUMEROUS SHOWERS WILL OCCUR TODAY LASTING INTO THIS EVENING. ALSO INCLUDED VCTS FOR THIS AFTERNOON AND EARLY EVENING. MVFR TO IFR CONDITIONS WILL BECOME MAINLY MVFR BY 15Z THEN PREDOMINATELY VFR BY 19Z OUTSIDE SHOWERS AND THUNDERSTORMS. CONDITIONS LOWERING AGAIN AFTER 30/05Z TO MVFR AND IFR. WINDS TODAY BECOMING SE-S 8-11 KTS...DECREASING TONIGHT TO 3-7 KTS AND BECOMING MORE EASTERLY AT KJBR. JCL && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1011 PM EDT FRI MAY 30 2014 .SYNOPSIS... A BACKDOOR COLD FRONT WILL CONTINUE TO PUSH SOUTHWESTWARD TONIGHT...MOVING SOUTH OF THE FORECAST AREA BY SATURDAY. COOLER...MORE STABLE MARITIME AIR BEHIND THE FRONT WILL RESULT IN LESS SHOWER AND THUNDERSTORMS INTO THE WEEKEND AS HIGH PRESSURE BUILDS OVER THE REGION. HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION NEXT WEEK BRINGING WARMER AND MORE HUMID CONDITIONS BACK TO THE REGION ALONG WITH INCREASING CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH SATURDAY/... AS OF 1010 PM EDT FRIDAY... NO SIGNIFICANT ADJUSTMENTS LATE THIS EVENING AS SCATTERED SHALLOW CONVECTION SLOWLY WEAKENS ACROSS NW NC AND GRAYSON/CARROLL COUNTY AREAS OF SW VA. THERE HAS BEEN LITTLE IF ANY LTG DETECTED IN THESE SHOWERS LAST SEVERAL HOURS AS THEY SLOWLY DRIFT SOUTHEAST. RAINFALL RATES ARE NOT ALL THAT HIGH ANYMORE...LESS THAN AN INCH PER HOUR...BUT MOVING SLOWLY ENOUGH THAT SOME ISOLATED MINOR FLOODING OF POOR DRAINAGE AREAS IS NOT OUT OF THE QUESTION...BUT THIS LOOKS LIKE IT WILL BE CONFINED TO WILKES AND YADKIN COUNTIES THROUGH MIDNIGHT. OTHERWISE SHOWERS WILL LIKELY DISSIPATE WITHIN A COUPLE HOURS AFTER MIDNIGHT WITH LOSS OF ANY REMAINING INSTABILITY...AND HRRR DEPICTS THIS IDEA BEST...ALTHOUGH SOME OTHER MODELS HANG TO SOME LIGHT SHOWERS THROUGH ENTIRE NIGHT. SLOWLY REDUCE POPS ALL NIGHT DOWN ION FAR SW WITH ONLY A SMALL AREAS OF SLIGHT CHC BY MORNING BUT WOULD NOT BE SURPIRSED IF ALL PRECIP IS GONE BY 2 OR 3AM. BIG QUESTION FOR OVERNIGHT IS AMOUNT OF STRATUS THAT WILL SPREAD ACROSS THE AREA...AS WELL AS FOG DEVELOPMENT. WITH DRIER AIR MOVING IN FROM THE NORTH THINK STRATUS WILL NOT BE AS WIDESPREAD AS PREVIOUS NIGHT AND PERHAPS LIMITED TO NEAR BLUE RIDGE AND NRV. BACKED OFF SLIGHTLY ON OVERALL CLOUD COVER...ESPECIALLY FAR WEST...BUT THINK VALLEY FOG WILL EVENTUALLY FORM AS WELL AS ALONG BLUE RIDGE AND MUCH OF PIEDMONT AS WELL. NO CHANGES TO OVERNIGHT LOWS. PREV DISCUSSION AS OF 700 PM EDT FRIDAY... MINOR UPDATE TO ADJUST POPS FOR CURRENT RADAR AND REDUCE SKY COVER OVER SE WV PER LATEST SATELLITE IMAGERY. STILL EXPECTING LOW CLOUDS TO FILL IN MORE ACROSS THE EAST AND INTO ROA AND NRV AFTER SUNSET...BUT MAY STAY RELATIVELY CLOUD FREE A LITTLE LONGER IN FAR WEST. ISOLD SHWRS NORTH OF ROANOKE SHOULD QUICKLY DIE WITH SUNSET...BUT SMALL AREA OF SHOWERS AND ISOLD THUNDER IN NW NC AND AROUND GALAX TO HILLSVILLE MAY PERSIST UNTIL ABOUT MIDNIGHT SINCE IN VICINITY OF WEAK FRONTAL BOUNDARY AND MODELS SUGGEST WEAK INSTABILITY LINGERS THERE INTO LATE EVENING. KEEPING ALL POPS BELOW LIKELY BUT KEPT SOME MID CHANCE A LITTLE LONGER INTO EVENING DOWN IN NC FOOTHILLS. SOME MINOR CONCERNS ABOUT HEAVY RAINFALL AS THESE STORMS ARE DRIFTING SLOWLY SOUTHEAST BUT MAY LINE UP MORE DURING EVENING. STILL...NOT PRODUCING ESPECIALLY HIGH RAINFALL RATES...LESS THAN YESTERDAY...BUT IF THEY LINGER OVER THE SAME AREAS FOR AWHILE...ESPECIALLY THOSE THAT HAD AN INCH OR TWO OF RAIN YESTERDAY...COULD BE SOME MINOR ISSUES WITH WATER IN POOR DRAINAGE AREAS. PREV DISCUSSION AS OF 330 PM EDT FRIDAY... DIFFUSE BACKDOOR COLD FRONT STRETCHES ACROSS SOUTHWESTERN PORTIONS OF THE FORECAST AREA THIS AFTERNOON. CONVECTION DEVELOPING IN THE MOIST UNSTABLE AIR INVOF THE SURFACE BOUNDARY AND TRAVEL SOUTHEAST ALONG THE SOUTHERN EDGE OF WEAK NORTHWEST FLOW ALOFT. SFC BASED CAPES THIS AFTERNOON HAVE CLIMB TO 1000 TO 2000 J/KG WITH LIS AROUND MINUS 4 ACROSS SOUTHWEST CORNER OF CWA THIS AFTERNOON. HOWEVER...WEAK VERTICAL SHEAR WILL LIMIT STORM ORGANIZATION AND LIFE SPAN THIS AFTERNOON INTO THIS EVENING...LOCALLY HEAVY RAINS...GUSTY WINDS AND HAIL ARE POSSIBLE WITH THE STRONGEST THUNDERSTORMS DURING THE NEXT COUPLE OF HOURS. IN SHARP CONTRAST...MARINE AMS IN THE EASTERN PORTION OF THE FORECAST AREA HAS BEEN VERY SLOW TO ERODE AND HOLDING TEMPERATURES DOWN. HARD TO TELL HOW MUCH SUN ANGLE AND MIXING WILL BREAK UP THE LOW CLOUDS THIS EVENING INTO TONIGHT. SATELLITE TRENDS SHOWED THAT WEST EDGE OF CLOUDS BREAKING UP BEFORE SUNSET. DECIDED TO PLAY POPS TONIGHT CLOSE TO A BLEND OF HRRR AND NAM WITH HIGHEST CHANCES IN SOUTHWEST BASICALLY WEST OF I77. LOW CLOUDS AND FOG WILL REDEVELOP OVERNIGHT. WENT WITH LOW TEMPERATURES TONIGHT CLOSE TO THE ADJMETBC WITH READINGS FROM THE MID 50S IN THE COOLER MOUNTAIN VALLEYS TO THE LOWER 60S IN THE SOUTHEAST. WITH BOUNDARY ACROSS NORTH CAROLINA AND SOUTHEAST UPSLOPE FLOW...KEPT ISOLATED SCATTERED POPS FOR CONVECTION ACROSS SOUTHWEST CORNER OF CWA. THE SWODY2 HAS PUSHED MENTION OF THUNDERSTORMS SOUTH OF OUR FORECAST AREA FOR SATURDAY. MORNING LOW CLOUDS AND FOG SHOULD MIX OUT OR LIFT BY LATE SATURDAY MORNING. HIGH TEMPERATURES SATURDAY ARE A CHALLENGE WITH EASTERLY FLOW AND CLOUD COVER. RAISED HIGHS UP SATURDAY AFTERNOON WITH READINGS FROM THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... AS OF 330 PM EDT FRIDAY... DIFFUSE FRONT WASHES OUT OVER THE SOUTHERN APPALACHIANS AS SURFACE HIGH PRESSURE SINKS SOUTH ACROSS THE DELMARVA SUNDAY. THE SURFACE HIGH THEN BECOMES POSITIONED JUST OFF THE CAROLINA COAST MONDAY. EXPECTING A DRY FINISH TO THE WEEKEND ALONG WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES...FOLLOWED BY A TRANSITION TO WARMER TEMPERATURES AND A THREAT OF AFTERNOON SHOWERS BEGINNING MONDAY. FOR SATURDAY NIGHT AND SUNDAY OR UNTIL THE HIGH BECOMES SITUATED OFF THE SOUTHEAST ATLANTIC COAST...SURFACE WINDS WILL REMAIN FROM THE EAST. THIS WILL PROMOTE SHALLOW UPSLOPE CLOUDINESS ALONG AND EAST OF THE APPALACHIAN DIVIDE...BKN SORT OF CONDITIONS SATURDAY NIGHT AND SCATTERED SUNDAY. BY MONDAY TENDENCY WILL BE FOR MODERATE CU FORMATION OVER THE MOUNTAINS AS RETURN SOUTHWESTERLY FLOW BRINGS INCREASING DEWPOINTS AND HIGHER CAPE. H85 TEMPS OF 8C IN THE VA PIEDMONT ON SUNDAY WILL REBOUND CLOSER TO 15C ON MONDAY. SUNDAY DEFINITELY LOOKS LIKE A WINNER IN TERMS OF COMFORT FOR THE FIRST DAY OF JUNE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 345 PM EDT FRIDAY... THE UPPER FLOW PATTERN NEXT WEEK WILL FEATURE A PERSISTENT UPPER RIDGE CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE SOUTHERN CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS RIDGE...A MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL AND NORTHERN CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT WAVE ENERGY RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT. WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE NORM FOR OVERNIGHT LOWS. THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IT WILL MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN THE FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF THIS UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE TYPICAL DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN THE MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND CONVERGENCE WILL BE THE GREATEST. WITH WESTERLY SORT OF WINDS ALOFT...A LEE TROUGH WILL LIKELY EXIST OVER THE PIEDMONT WHICH WILL AID IN SCATTERED LATE AFTERNOON STORM DEVELOPMENT THERE TOO. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... AS OF 800 PM EDT FRIDAY... DIFFUSE BACKDOOR FRONT REMAINS ACROSS THE FAR SOUTHWESTERN PART OF THE CWA THIS EVENING. THIS BOUNDARY EXPECTED TO MOVE SOUTHWARD TONIGHT INTO SATURDAY. EVENING SCATTERED SHOWERS AND ISOLATED THUNDER CONFINED TO NEAR THIS BOUNDARY WHICH IS ACROSS NW NC MOUNTAINS AND FOOTHILLS...SOUTH AND WEST OF TAF AIRPORTS. A VERY BRIEF SHOWER STILL CANNOT BE RULED OUT OF ROA/LYH/BCB..AND MAYBE DAN THROUGH 04Z...BUT THUNDER NOT LIKELY. HAVE NOT INCLUDED ANY MENTION OF THIS IN ACTUAL TAFS SINCE PROBABILITY VERY LOW. IN THE EAST BEHIND THE BACKDOOR FRONT...MOIST EASTERLY MARITIME FLOW SHOULD ALLOW IFR CIGS TO ONCE AGAIN DEVELOP AFTER SUNSET BUT MAY TAKE A WHILE TO DEVELOP COMPARED TO PREVIOUS NIGHT AS SOMEWHAT DRIER AIR HAS MOVED IN ALOFT. SKIES WILL REMAIN VFR SCATTERED AT BLF AND LWB UNTIL AFTER MIDNIGHT AND MAY NOT BECOME BROKEN AT ALL AT BLF. IFR FOG ALSO LIKELY TO DEVELOP AT MOST SITES...EXCEPT FOR ROA AND BLF. THEN WITH DRIER AIR CONTINUING TO FILTER DOWN FROM NORTH BEHIND THIS FRONT...VFR CONDITIONS SHOULD QUICKLY RETURN AT MOST LOCATIONS AFTER SUNRISE SATURDAY...BUT DIFFICULT TO KNOW HOW QUICKLY VFR BROKEN LAYER WILL GO SCATTERED IF AT ALL. WINDS WILL BE WEAKEN TO LIGHT EASTERLY OR CALM TONIGHT AND THEN NORTHEAST TO SOUTHEAST AT 5-10 KT DURING THE DAY SATURDAY. OVERALL MEDIUM CONFIDENCE IN CIGS AND VSBYS BEING AT IFR TONIGHT...WITH HIGHER CONFIDENCE OF VFR BY MID MORNING SATURDAY. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... VFR CONDITIONS WILL PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY OVERNIGHT IN MOUNTAIN VALLEYS. THE NEXT CHANCE AT SCATTERED SHOWER AND THUNDERSTORM ACTIVITY RETURNS BY MONDAY AND ESPECIALLY INTO THE MID WEEK PERIOD. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...KK/SK SHORT TERM...PM LONG TERM...PM AVIATION...KK/RAB/SK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
800 PM EDT FRI MAY 30 2014 .SYNOPSIS... A BACKDOOR COLD FRONT WILL CONTINUE TO PUSH SOUTHWESTWARD TONIGHT...MOVING SOUTH OF THE FORECAST AREA BY SATURDAY. COOLER...MORE STABLE MARITIME AIR BEHIND THE FRONT WILL RESULT IN LESS SHOWER AND THUNDERSTORMS INTO THE WEEKEND AS HIGH PRESSURE BUILDS OVER THE REGION. HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION NEXT WEEK BRINGING WARMER AND MORE HUMID CONDITIONS BACK TO THE REGION ALONG WITH INCREASING CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH SATURDAY/... AS OF 700 PM EDT FRIDAY... MINOR UPDATE TO ADJUST POPS FOR CURRENT RADAR AND REDUCE SKY COVER OVER SE WV PER LATEST SATELLITE IMAGERY. STILL EXPECTING LOW CLOUDS TO FILL IN MORE ACROSS THE EAST AND INTO ROA AND NRV AFTER SUNSET...BUT MAY STAY RELATIVELY CLOUD FREE A LITTLE LONGER IN FAR WEST. ISOLD SHWRS NORTH OF ROANOKE SHOULD QUICKLY DIE WITH SUNSET...BUT SMALL AREA OF SHOWERS AND ISOLD THUNDER IN NW NC AND AROUND GALAX TO HILLSVILLE MAY PERSIST UNTIL ABOUT MIDNIGHT SINCE IN VICINITY OF WEAK FRONTAL BOUNDARY AND MODELS SUGGEST WEAK INSTABILITY LINGERS THERE INTO LATE EVENING. KEEPING ALL POPS BELOW LIKELY BUT KEPT SOME MID CHANCE A LITTLE LONGER INTO EVENING DOWN IN NC FOOTHILLS. SOME MINOR CONCERNS ABOUT HEAVY RAINFALL AS THESE STORMS ARE DRIFTING SLOWLY SOUTHEAST BUT MAY LINE UP MORE DURING EVENING. STILL...NOT PRODUCING ESPECIALLY HIGH RAINFALL RATES...LESS THAN YESTERDAY...BUT IF THEY LINGER OVER THE SAME AREAS FOR AWHILE...ESPECIALLY THOSE THAT HAD AN INCH OR TWO OF RAIN YESTERDAY...COULD BE SOME MINOR ISSUES WITH WATER IN POOR DRAINAGE AREAS. PREV DISCUSSION AS OF 330 PM EDT FRIDAY... DIFFUSE BACKDOOR COLD FRONT STRETCHES ACROSS SOUTHWESTERN PORTIONS OF THE FORECAST AREA THIS AFTERNOON. CONVECTION DEVELOPING IN THE MOIST UNSTABLE AIR INVOF THE SURFACE BOUNDARY AND TRAVEL SOUTHEAST ALONG THE SOUTHERN EDGE OF WEAK NORTHWEST FLOW ALOFT. SFC BASED CAPES THIS AFTERNOON HAVE CLIMB TO 1000 TO 2000 J/KG WITH LIS AROUND MINUS 4 ACROSS SOUTHWEST CORNER OF CWA THIS AFTERNOON. HOWEVER...WEAK VERTICAL SHEAR WILL LIMIT STORM ORGANIZATION AND LIFE SPAN THIS AFTERNOON INTO THIS EVENING...LOCALLY HEAVY RAINS...GUSTY WINDS AND HAIL ARE POSSIBLE WITH THE STRONGEST THUNDERSTORMS DURING THE NEXT COUPLE OF HOURS. IN SHARP CONTRAST...MARINE AMS IN THE EASTERN PORTION OF THE FORECAST AREA HAS BEEN VERY SLOW TO ERODE AND HOLDING TEMPERATURES DOWN. HARD TO TELL HOW MUCH SUN ANGLE AND MIXING WILL BREAK UP THE LOW CLOUDS THIS EVENING INTO TONIGHT. SATELLITE TRENDS SHOWED THAT WEST EDGE OF CLOUDS BREAKING UP BEFORE SUNSET. DECIDED TO PLAY POPS TONIGHT CLOSE TO A BLEND OF HRRR AND NAM WITH HIGHEST CHANCES IN SOUTHWEST BASICALLY WEST OF I77. LOW CLOUDS AND FOG WILL REDEVELOP OVERNIGHT. WENT WITH LOW TEMPERATURES TONIGHT CLOSE TO THE ADJMETBC WITH READINGS FROM THE MID 50S IN THE COOLER MOUNTAIN VALLEYS TO THE LOWER 60S IN THE SOUTHEAST. WITH BOUNDARY ACROSS NORTH CAROLINA AND SOUTHEAST UPSLOPE FLOW...KEPT ISOLATED SCATTERED POPS FOR CONVECTION ACROSS SOUTHWEST CORNER OF CWA. THE SWODY2 HAS PUSHED MENTION OF THUNDERSTORMS SOUTH OF OUR FORECAST AREA FOR SATURDAY. MORNING LOW CLOUDS AND FOG SHOULD MIX OUT OR LIFT BY LATE SATURDAY MORNING. HIGH TEMPERATURES SATURDAY ARE A CHALLENGE WITH EASTERLY FLOW AND CLOUD COVER. RAISED HIGHS UP SATURDAY AFTERNOON WITH READINGS FROM THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... AS OF 330 PM EDT FRIDAY... DIFFUSE FRONT WASHES OUT OVER THE SOUTHERN APPALACHIANS AS SURFACE HIGH PRESSURE SINKS SOUTH ACROSS THE DELMARVA SUNDAY. THE SURFACE HIGH THEN BECOMES POSITIONED JUST OFF THE CAROLINA COAST MONDAY. EXPECTING A DRY FINISH TO THE WEEKEND ALONG WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES...FOLLOWED BY A TRANSITION TO WARMER TEMPERATURES AND A THREAT OF AFTERNOON SHOWERS BEGINNING MONDAY. FOR SATURDAY NIGHT AND SUNDAY OR UNTIL THE HIGH BECOMES SITUATED OFF THE SOUTHEAST ATLANTIC COAST...SURFACE WINDS WILL REMAIN FROM THE EAST. THIS WILL PROMOTE SHALLOW UPSLOPE CLOUDINESS ALONG AND EAST OF THE APPALACHIAN DIVIDE...BKN SORT OF CONDITIONS SATURDAY NIGHT AND SCATTERED SUNDAY. BY MONDAY TENDENCY WILL BE FOR MODERATE CU FORMATION OVER THE MOUNTAINS AS RETURN SOUTHWESTERLY FLOW BRINGS INCREASING DEWPOINTS AND HIGHER CAPE. H85 TEMPS OF 8C IN THE VA PIEDMONT ON SUNDAY WILL REBOUND CLOSER TO 15C ON MONDAY. SUNDAY DEFINITELY LOOKS LIKE A WINNER IN TERMS OF COMFORT FOR THE FIRST DAY OF JUNE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 345 PM EDT FRIDAY... THE UPPER FLOW PATTERN NEXT WEEK WILL FEATURE A PERSISTENT UPPER RIDGE CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE SOUTHERN CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS RIDGE...A MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL AND NORTHERN CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT WAVE ENERGY RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT. WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE NORM FOR OVERNIGHT LOWS. THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IT WILL MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN THE FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF THIS UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE TYPICAL DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN THE MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND CONVERGENCE WILL BE THE GREATEST. WITH WESTERLY SORT OF WINDS ALOFT...A LEE TROUGH WILL LIKELY EXIST OVER THE PIEDMONT WHICH WILL AID IN SCATTERED LATE AFTERNOON STORM DEVELOPMENT THERE TOO. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AS OF 800 PM EDT FRIDAY... DIFFUSE BACKDOOR FRONT REMAINS ACROSS THE FAR SOUTHWESTERN PART OF THE CWA THIS EVENING. THIS BOUNDARY EXPECTED TO MOVE SOUTHWARD TONIGHT INTO SATURDAY. EVENING SCATTERED SHOWERS AND ISOLATED THUNDER CONFINED TO NEAR THIS BOUNDARY WHICH IS ACROSS NW NC MOUNTAINS AND FOOTHILLS...SOUTH AND WEST OF TAF AIRPORTS. A VERY BRIEF SHOWER STILL CANNOT BE RULED OUT OF ROA/LYH/BCB..AND MAYBE DAN THROUGH 04Z...BUT THUNDER NOT LIKELY. HAVE NOT INCLUDED ANY MENTION OF THIS IN ACTUAL TAFS SINCE PROBABILITY VERY LOW. IN THE EAST BEHIND THE BACKDOOR FRONT...MOIST EASTERLY MARITIME FLOW SHOULD ALLOW IFR CIGS TO ONCE AGAIN DEVELOP AFTER SUNSET BUT MAY TAKE A WHILE TO DEVELOP COMPARED TO PREVIOUS NIGHT AS SOMEWHAT DRIER AIR HAS MOVED IN ALOFT. SKIES WILL REMAIN VFR SCATTERED AT BLF AND LWB UNTIL AFTER MIDNIGHT AND MAY NOT BECOME BROKEN AT ALL AT BLF. IFR FOG ALSO LIKELY TO DEVELOP AT MOST SITES...EXCEPT FOR ROA AND BLF. THEN WITH DRIER AIR CONTINUING TO FILTER DOWN FROM NORTH BEHIND THIS FRONT...VFR CONDITIONS SHOULD QUICKLY RETURN AT MOST LOCATIONS AFTER SUNRISE SATURDAY...BUT DIFFICULT TO KNOW HOW QUICKLY VFR BROKEN LAYER WILL GO SCATTERED IF AT ALL. WINDS WILL BE WEAKEN TO LIGHT EASTERLY OR CALM TONIGHT AND THEN NORTHEAST TO SOUTHEAST AT 5-10 KT DURING THE DAY SATURDAY. OVERALL MEDIUM CONFIDENCE IN CIGS AND VSBYS BEING AT IFR TONIGHT...WITH HIGHER CONFIDENCE OF VFR BY MID MORNING SATURDAY. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... VFR CONDITIONS WILL PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY OVERNIGHT IN MOUNTAIN VALLEYS. THE NEXT CHANCE AT SCATTERED SHOWER AND THUNDERSTORM ACTIVITY RETURNS BY MONDAY AND ESPECIALLY INTO THE MID WEEK PERIOD. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...KK/SK SHORT TERM...PM LONG TERM...PM AVIATION...KK/RAB/SK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
140 PM EDT THU MAY 29 2014 .SYNOPSIS... LOW PRESSURE WAS IN SOUTHERN PENNSYLVANIA WITH A COLD FRONT EXTENDING INTO NORTHEAST NORTH CAROLINA. THIS FRONT WILL MOVE SOUTH TODAY AND STALL IN THE CAROLINAS TONIGHT. HIGH PRESSURE WILL BUILD IN OVER THE EASTERN UNITED STATES BY THE WEEKEND WITH SLIGHTLY COOLER AND DRIER AIR FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 921 AM EDT THURSDAY... BACKDOOR COLD FRONT...HIGHLIGHTED NICELY BY MSAS ANALYSIS OF LIFTED INDEX AND PRESSURE CHANGES...PUSHING INTO EASTERN PORTIONS OF FORECAST AREA THIS MORNING. KFCX 88D SHOWED A FEW SHOWERS MOVING EAST ACROSS THE NORTH. SATELLITE IMAGES INDICATED SUNSHINE IN THE WEST WITH LOW CLOUDS ADVANCING WESTWARD TOWARDS BLUE RIDGE. SFC OBS REPORT THAT IFR CLOUDS HAVE REACH LYH AND DAN THIS MORNING. OUTSIDE THE LOW CLOUDS...TEMPERATURES HAVE CLIMB QUICKLY THIS MORNING. MODIFIED TEMPERATURES AND HIGHS UP AS FEW DEGREES WHERE READINGS ARE WARMER WITH ADDITIONAL SUNSHINE. STILL LOOKS LIKE MOST LOCATIONS WILL BE CLOUDY BY 18Z THIS AFTERNOON. THE COMBINATION OF LOW LEVEL CONVERGENCE ALONG THE SURFACE FRONT AND THE LIFT FROM THE PASSING SHORT WAVE WILL RESULT IN SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. THE LOCAL RNK WRFARW AND HRRR SUGGEST THAT MOST OF THE CONVECTION STARTS AFTER 18Z THIS AFTERNOON...WITH NUMEROUS COVERAGE BY 00Z THIS EVENING. MORE CHANGES LATER THIS MORNING... AS OF 400 AM EDT THURSDAY... 500 MB PATTERN AMPLIFIES WITH A TROF ALONG THE EAST COAST DURING THIS TIME FRAME. A SHORT WAVE AND ASSOCIATED JET STREAK CROSS FROM THE OHIO VALLEY INTO NORTH CAROLINA BY MIDNIGHT. MSAS ANALYSIS OF LIFTED INDEX AND PRESSURE CHANGES SHOWED FRONT WAS JUST INTO THE EASTERN COUNTY WARNING AREA AT 3AM. MODELS BRING THE BOUNDARY AS FAR WEST AS ROANOKE DURING THE DAY THEN EXPECTING THE STABLE AIR TO ADVANCE DOWN THE EAST SLOPES OF THE BLUE RIDGE...ALTHOUGH VERY SHALLOW OVERNIGHT. MOISTURE ABOVE 700MB GETS PUSHED TO THE FAR SOUTHWEST COUNTIES OF THE FORECAST AREA BY MORNING. BUT STILL AMPLE LOW LEVEL MOISTURE THROUGH TONIGHT. THE COMBINATION OF LOW LEVEL CONVERGENCE ALONG THE SURFACE FRONT AND THE LIFT FROM THE PASSING SHORT WAVE WILL RESULT IN SCATTERED TO NUMEROUS SHOWERS THIS AFTERNOON AND EVENING. THE AIR MASS WEST OF THE BOUNDARY WILL STILL BE UNSTABLE ENOUGH FOR THUNDERSTORMS. BUFKIT FOR ROANOKE WAS ALSO SHOWING SUPPORT FOR ELEVATED CONVECTION TODAY. CLOUDS...PRECIPITATION AND COOLER AIR MASS BEHIND THE FRONT WILL LEAD TO COOLER MAXIMUM TEMPERATURES THAN PAST FEW DAYS IN THE EAST. WESTERN PARTS OF THE COUNTY WARNING AREA THAT STILL GET ENOUGH SUN WILL AGAIN REACH THE 80S FOR HIGHS. USED AN NON-DIURNAL TEMPERATURES CURVE FOR TODAY AND STAYED CLOSE TO MET GUIDANCE FOR MAXIMUM TEMPERATURES. ALSO USED SLIGHTLY COOLER MET FOR LOWS TONIGHT. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... AS OF 400 AM EDT THURSDAY... AN ABNORMAL PATTERN FOR LATE MAY...WITH A DEVELOPING REX BLOCK OVER THE MISSISSIPPI RIVER VALLEY...AND A DEEPENING UPPER TROUGH OVER NEW ENGLAND. VEERING THE EASTERLY FLOW TO THE S AND SW WILL BE A VERY SLOW PROCESS...UNTIL THE NEW ENGLAND TROUGH FINALLY MOVES OFF THE COAST AND THE UPPER RIDGE CLOSES OFF OVER THE SOUTHEAST BY MONDAY. CONTINUED WHAT HAS BEEN A NIGHTLY TREND OF LOWERING MAX T JUST ABOUT EACH DAY...ESPECIALLY BELOW THE MEX GUIDANCE WHICH JUST CAN`T HANDLE THIS ODD ARRANGEMENT OF UPPER HIGHS AND LOWS. HIGHS TEMPS THROUGH THIS PERIOD MAY FALL BELOW NORMAL...SAVE EXTREME SW VA AND SE WEST VA. STILL SOME CLASHING OF AIRMASSES AND SURFACE CONVERGENCE KEEPS SHOWERS/STORMS IN THE FORECAST THROUGH NW NC AND EXTREME SW VA ON FRIDAY. ANOTHER STRONGER SURFACE HIGH ROLLING ACROSS THE LAKES AND INTO NEW ENGLAND BY SUNDAY...WILL LIKELY KEEP ANY SHOWER DEVELOPMENT SUPPRESSED TO NW NC...IF AT ALL SATURDAY AND SUNDAY. MODELS HINTING AT SOME DRIZZLE/FOG/LIGHT RAIN SHOWERS BOTH FRIDAY AND SATURDAY NIGHT WITH EASTERLY UPSLOPE FLOW ALONG THE BLUE RIDGE. ALSO...CLOUDS WILL PROBABLY FILL BACK IN DURING THE OVERNIGHTS...AS AFTERNOON MIXING ENDS. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 1245 PM EDT WEDNESDAY... GOING TO BE HEADING BACK TO SUMMER TEMPS EARLY NEXT WEEK AS UPPER RIDGE SITUATES ITSELF OVER THE WRN SIDE OF THE APPALACHIANS. BY MIDWEEK...MODELS BREAK DOWN THE UPPER RIDGE AS TROUGH DIGS ACROSS SRN CANADA. AT THE SFC...HIGH PRESSURE WORKS FROM THE MID ATLANTIC TO THE SOUTHEAST COAST. THE PATTERN SUGGESTS NO ORGANIZED SYSTEMS TO AFFECT US...BUT WILL HAVE TO WATCH UPSTREAM ESPECIALLY TUE-WED AS THE 5H FLOW FLATTENS FOR FASTER MOVING SHORTWAVES. OVERALL WILL BE TYPICAL SUMMER DIURNAL RANGE IN SHRA/TSRA THREAT...WITH BEST CHANCES IN THE MOUNTAINS ESPECIALLY TUE-WED. A LEE TROUGH SETS UP AS WELL OVER THE PIEDMONT WHICH COULD AID IN STORM DEVELOPMENT. FOR NOW KEEPING IN POPS IN THE CHANCE RANGE...WITH SUNDAY LOOKING DRY. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 135 PM EDT THURSDAY... MULTIPLE CHANGES IN WEATHER CONDITIONS ARE EXPECTED THIS AFTERNOON INTO TONIGHT. CEILINGS HAVE LOWERED TO IFR/LIFR BEHIND THE FRONT...INCLUDING AT KLYH AND KDAN. EXPECT ONLY LIMITED IMPROVEMENT THIS AFTERNOON INTO TONIGHT...MAYBE TO MVFR. A SHORT WAVE TRACKING OUT OF THE OHIO VALLEY WILL CROSS THE REGION AND INTERACT WITH THE FRONT...LEADING TO NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. ONCE THIS FEATURE PASSES TO THE SOUTHEAST...MUCH OF THE PRECIPITATION WILL BE LIMITED TO THE EASTERN SLOPES OF THE BLUE RIDGE...WITH LIGHT RAIN OR DRIZZLE. THERE MAY BE A BRIEF PERIOD OF VFR CEILINGS AND VISIBILITIES AFTER THE BULK SHOWERS AND THUNDERSTORMS ENDS AND BEFORE SUNSET BUT CONFIDENCE IS LOW ON THE TIMING ANY AMOUNT OF IMPROVEMENT. AFTER 00Z CEILINGS WILL LOWER TO IFR. FOG WILL ALSO DEVELOP OVERNIGHT... WITH THE LOWER VISIBILITIES EAST OF THE BLUE RIDGE. SURFACE RIDGE OF HIGH PRESSURE GRADUALLY BUILDING IN BEHIND THE FRONT FROM THE NORTHEAST WILL ALLOW FOR A SLOW RETURN TO VFR CONDITIONS IN MOST AREAS BY FRIDAY NIGHT. MEDIUM CONFIDENCE IN CEILINGS AND VISIBILITIES DURING THE TAF PERIOD. HIGH TO MEDIUM CONFIDENCE IN WINDS DURING THE PERIOD. VFR CONDITIONS WILL PREVAIL...BUT SOME LOCALIZED MVFR RESTRICTIONS MAY STILL PERSIST INTO THE WEEKEND ACROSS THE SOUTHWEST MOUNTAINS...MAINLY SOUTH OF KBLF. BY SUNDAY NIGHT AND MONDAY THE ENTIRE REGION WILL TRANSITION BACK TO VFR CONDITIONS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...KM LONG TERM...WP AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
938 AM EDT THU MAY 29 2014 .SYNOPSIS... LOW PRESSURE WAS IN SOUTHERN PENNSYLVANIA WITH A COLD FRONT EXTENDING INTO NORTHEAST NORTH CAROLINA. THIS FRONT WILL MOVE SOUTH TODAY AND STALL IN THE CAROLINAS TONIGHT. HIGH PRESSURE WILL BUILD IN OVER THE EASTERN UNITED STATES BY THE WEEKEND WITH SLIGHTLY COOLER AND DRIER AIR FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 921 AM EDT THURSDAY... BACKDOOR COLD FRONT...HIGHLIGHTED NICELY BY MSAS ANALYSIS OF LIFTED INDEX AND PRESSURE CHANGES...PUSHING INTO EASTERN PORTIONS OF FORECAST AREA THIS MORNING. KFCX 88D SHOWED A FEW SHOWERS MOVING EAST ACROSS THE NORTH. SATELLITE IMAGES INDICATED SUNSHINE IN THE WEST WITH LOW CLOUDS ADVANCING WESTWARD TOWARDS BLUE RIDGE. SFC OBS REPORT THAT IFR CLOUDS HAVE REACH LYH AND DAN THIS MORNING. OUTSIDE THE LOW CLOUDS...TEMPERATURES HAVE CLIMB QUICKLY THIS MORNING. MODIFIED TEMPERATURES AND HIGHS UP AS FEW DEGREES WHERE READINGS ARE WARMER WITH ADDITIONAL SUNSHINE. STILL LOOKS LIKE MOST LOCATIONS WILL BE CLOUDY BY 18Z THIS AFTERNOON. THE COMBINATION OF LOW LEVEL CONVERGENCE ALONG THE SURFACE FRONT AND THE LIFT FROM THE PASSING SHORT WAVE WILL RESULT IN SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. THE LOCAL RNK WRFARW AND HRRR SUGGEST THAT MOST OF THE CONVECTION STARTS AFTER 18Z THIS AFTERNOON...WITH NUMEROUS COVERAGE BY 00Z THIS EVENING. MORE CHANGES LATER THIS MORNING... AS OF 400 AM EDT THURSDAY... 500 MB PATTERN AMPLIFIES WITH A TROF ALONG THE EAST COAST DURING THIS TIME FRAME. A SHORT WAVE AND ASSOCIATED JET STREAK CROSS FROM THE OHIO VALLEY INTO NORTH CAROLINA BY MIDNIGHT. MSAS ANALYSIS OF LIFTED INDEX AND PRESSURE CHANGES SHOWED FRONT WAS JUST INTO THE EASTERN COUNTY WARNING AREA AT 3AM. MODELS BRING THE BOUNDARY AS FAR WEST AS ROANOKE DURING THE DAY THEN EXPECTING THE STABLE AIR TO ADVANCE DOWN THE EAST SLOPES OF THE BLUE RIDGE...ALTHOUGH VERY SHALLOW OVERNIGHT. MOISTURE ABOVE 700MB GETS PUSHED TO THE FAR SOUTHWEST COUNTIES OF THE FORECAST AREA BY MORNING. BUT STILL AMPLE LOW LEVEL MOISTURE THROUGH TONIGHT. THE COMBINATION OF LOW LEVEL CONVERGENCE ALONG THE SURFACE FRONT AND THE LIFT FROM THE PASSING SHORT WAVE WILL RESULT IN SCATTERED TO NUMEROUS SHOWERS THIS AFTERNOON AND EVENING. THE AIR MASS WEST OF THE BOUNDARY WILL STILL BE UNSTABLE ENOUGH FOR THUNDERSTORMS. BUFKIT FOR ROANOKE WAS ALSO SHOWING SUPPORT FOR ELEVATED CONVECTION TODAY. CLOUDS...PRECIPITATION AND COOLER AIR MASS BEHIND THE FRONT WILL LEAD TO COOLER MAXIMUM TEMPERATURES THAN PAST FEW DAYS IN THE EAST. WESTERN PARTS OF THE COUNTY WARNING AREA THAT STILL GET ENOUGH SUN WILL AGAIN REACH THE 80S FOR HIGHS. USED AN NON-DIURNAL TEMPERATURES CURVE FOR TODAY AND STAYED CLOSE TO MET GUIDANCE FOR MAXIMUM TEMPERATURES. ALSO USED SLIGHTLY COOLER MET FOR LOWS TONIGHT. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... AS OF 400 AM EDT THURSDAY... AN ABNORMAL PATTERN FOR LATE MAY...WITH A DEVELOPING REX BLOCK OVER THE MISSISSIPPI RIVER VALLEY...AND A DEEPENING UPPER TROUGH OVER NEW ENGLAND. VEERING THE EASTERLY FLOW TO THE S AND SW WILL BE A VERY SLOW PROCESS...UNTIL THE NEW ENGLAND TROUGH FINALLY MOVES OFF THE COAST AND THE UPPER RIDGE CLOSES OFF OVER THE SOUTHEAST BY MONDAY. CONTINUED WHAT HAS BEEN A NIGHTLY TREND OF LOWERING MAX T JUST ABOUT EACH DAY...ESPECIALLY BELOW THE MEX GUIDANCE WHICH JUST CAN`T HANDLE THIS ODD ARRANGEMENT OF UPPER HIGHS AND LOWS. HIGHS TEMPS THROUGH THIS PERIOD MAY FALL BELOW NORMAL...SAVE EXTREME SW VA AND SE WEST VA. STILL SOME CLASHING OF AIRMASSES AND SURFACE CONVERGENCE KEEPS SHOWERS/STORMS IN THE FORECAST THROUGH NW NC AND EXTREME SW VA ON FRIDAY. ANOTHER STRONGER SURFACE HIGH ROLLING ACROSS THE LAKES AND INTO NEW ENGLAND BY SUNDAY...WILL LIKELY KEEP ANY SHOWER DEVELOPMENT SUPPRESSED TO NW NC...IF AT ALL SATURDAY AND SUNDAY. MODELS HINTING AT SOME DRIZZLE/FOG/LIGHT RAIN SHOWERS BOTH FRIDAY AND SATURDAY NIGHT WITH EASTERLY UPSLOPE FLOW ALONG THE BLUE RIDGE. ALSO...CLOUDS WILL PROBABLY FILL BACK IN DURING THE OVERNIGHTS...AS AFTERNOON MIXING ENDS. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 1245 PM EDT WEDNESDAY... GOING TO BE HEADING BACK TO SUMMER TEMPS EARLY NEXT WEEK AS UPPER RIDGE SITUATES ITSELF OVER THE WRN SIDE OF THE APPALACHIANS. BY MIDWEEK...MODELS BREAK DOWN THE UPPER RIDGE AS TROUGH DIGS ACROSS SRN CANADA. AT THE SFC...HIGH PRESSURE WORKS FROM THE MID ATLANTIC TO THE SOUTHEAST COAST. THE PATTERN SUGGESTS NO ORGANIZED SYSTEMS TO AFFECT US...BUT WILL HAVE TO WATCH UPSTREAM ESPECIALLY TUE-WED AS THE 5H FLOW FLATTENS FOR FASTER MOVING SHORTWAVES. OVERALL WILL BE TYPICAL SUMMER DIURNAL RANGE IN SHRA/TSRA THREAT...WITH BEST CHANCES IN THE MOUNTAINS ESPECIALLY TUE-WED. A LEE TROUGH SETS UP AS WELL OVER THE PIEDMONT WHICH COULD AID IN STORM DEVELOPMENT. FOR NOW KEEPING IN POPS IN THE CHANCE RANGE...WITH SUNDAY LOOKING DRY. && .AVIATION /13Z THURSDAY THROUGH MONDAY/... AS OF 730 AM EDT THURSDAY... MULTIPLE CHANGES IN WEATHER CONDITIONS ARE EXPECTED TODAY INTO TONIGHT. CEILINGS HAVE LOWERED TO IFR BEHIND THE FRONT...INCLUDING AT KLYH AND KDAN. EXPECT ONLY LIMITED IMPROVEMENT THROUGH 16Z/NOON...MAYBE TO MVFR. A SHORT WAVE TRACKING OUT OF THE OHIO VALLEY WILL CROSS THE REGION AND INTERACT WITH THE FRONT...LEADING TO NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. ONCE THIS FEATURE PASSES TO THE SOUTHEAST...MUCH OF THE PRECIPITATION WILL BE LIMITED TO THE EASTERN SLOPES OF THE BLUE RIDGE...WITH LIGHT RAIN OR DRIZZLE. THERE MAY BE A BRIEF PERIOD OF VFR CEILINGS AND VISIBILITIES AFTER THE BULK SHOWERS AND THUNDERSTORMS ENDS AND BEFORE SUNSET BUT CONFIDENCE IS LOW ON THE TIMING ANY AMOUNT OF IMPROVEMENT. AFTER 00Z CEILINGS WILL LOWER TO IFR. FOG WILL ALSO DEVELOP OVERNIGHT... WITH THE LOWER VISIBILITIES EAST OF THE BLUE RIDGE. SURFACE RIDGE OF HIGH PRESSURE GRADUALLY BUILDING IN BEHIND THE FRONT FROM THE NORTHEAST WILL ALLOW FOR A SLOW RETURN TO VFR CONDITIONS IN MOST AREAS BY FRIDAY NIGHT...BUT SOME LOCALIZED MVFR RESTRICTIONS MAY STILL PERSIST INTO THE WEEKEND ACROSS THE SOUTHWEST MOUNTAINS...MAINLY SOUTH OF KBLF. BY SUNDAY NIGHT AND MONDAY THE ENTIRE REGION WILL TRANSITION BACK TO VFR CONDITIONS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...KM LONG TERM...WP AVIATION...AMS/WERT
AREA FORECAST DISCUSSION
NWS PORTLAND OR
843 PM PDT FRI MAY 30 2014 .SYNOPSIS...A WEAK UPPER LEVEL TROUGH OF LOW PRES OVER THE PACIFIC NW WILL MOVE OFF TO THE E TONIGHT AND SATURDAY. HIGH PRES OVER THE NE PACIFIC WILL STRENGTHEN THIS WEEKEND AND PERSIST THROUGH MOST OF THE COMING WEEK...KEEPING THE REGION IN AN ONSHORE FLOW PATTERN. && .SHORT TERM...ABOVE SEASONAL TEMPERATURES TODAY ESPECIALLY INLAND. MOSTLY CLEAR SKIES THIS AFTERNOON AND EVENING EXCEPT FOR SOME STRATUS ALONG THE COASTLINE AND CUMULUS BUILDUPS OVER THE CASCADES. BETWEEN 3 PM AND 7 PM THERE WAS DEEPER CONVECTION ALONG THE CASCADE CREST FROM NEAR TIMOTHY LAKE TO MCKENZIE PASS. THERE WERE SOME LIGHTNING STRIKES DETECTED FROM THESE CELLS. SINCE 7 PM THE CELLS HAVE DIMINISHED AND MOVED OFF INTO EASTERN OREGON. MODELS CONTINUE TO INDICATE THE UPPER TROUGH OVER THE AREA WILL MOVE E TONIGHT...LEAVING THE REGION UNDER A DRY...WEAKLY CYCLONIC NW FLOW ALOFT FOR THE NEXT FEW DAYS. THIS WILL BRING MORE STABLE CONDITIONS. STRATUS OVER THE COASTAL WATERS FLOWING PARALLEL TO THE COASTLINE...GENERALLY FOLLOWING THE SURFACE ISOBARS. WITH THE LIGHT ONSHORE FLOW EXPECT SOME OF THE STRATUS WORKING THROUGH THE LOWER GAPS IN THE COASTAL TERRAIN OVERNIGHT AND EARLY SAT. A WEAK SHORTWAVE IS DEPICTED IN MODELS SUN MORNING...WHICH COUPLED WITH MARINE MOISTURE SUGGESTS A SLIGHT CHANCE FOR LIGHT SHOWERS IS NOT OUT OF ORDER FOR SUN MORNING. GFS SUGGESTS A WEAK DISTURBANCE LIFTING UP INTO NORTHERN CA MON MAY PULL SOME MID LEVEL MOISTURE N UP THE CASCADES MON AFTERNOON. ECMWF THOUGH REMAINS DRIER WITH WEAK SHORTWAVES STILL CROSSING OUT OF THE WNW. GIVEN THE UNCERTAINTY...WILL MAINTAIN A SLIGHT CHANCE FOR THUNDERSTORMS TO THE CASCADES MON AFTERNOON. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY... MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE GENERAL PATTERN EARLY NEXT WEEK OF A RIDGE OVER THE EASTERN PACIFIC WITH NORTHWEST FLOW ALOFT OVER THE PACIFIC NORTHWEST. GFS HAS A WEAK UPPER TROUGH EXITING OREGON AND WASHINGTON TUESDAY EVENING WHILE THE ECMWF IS A LITTLE FASTER. THIS SHOULD END THE THREAT OF SHOWER OR THUNDERSTORMS OVER THE CASCADES BY TUESDAY AFTERNOON AND EVENING SETTING UP FOR A DRY PATTERN FOR THE REMAINDER OF THE WEEK WITH TEMPERATURES NEAR NORMAL. WEST TO NORTHWEST FLOW ALOFT AND ONSHORE FLOW WILL LIKELY MEAN CLOUDS ALONG THE COAST MOVING INLAND DURING NIGHT AND DISSIPATING INLAND DURING THE AFTERNOONS WEDNESDAY THROUGH FRIDAY. SCHNEIDER && .AVIATION...VFR ACROSS THE REGION AT 03Z...EXCEPT FOR POCKETS OF MVFR CIGS ALONG THE N AND CENTRAL OREGON COASTLINE. CONVECTIVE DEBRIS CLOUDS HUGGING THE CASCADE CREST BUT THESE WILL CONTINUE TO SHIFT EAST OVER THE NEXT FEW HOURS. EXPECT INCREASING MVFR ALONG THE COAST TONIGHT...SPREADING INTO THE COASTAL RIVER DRAINAGES OVERNIGHT. HOW FAR THESE CLOUDS WILL PENETRATE INLAND LATE TONIGHT REMAINS A QUESTION MARK. RAW MODEL GUIDANCE SIGNATURES THAT ARE NORMALLY FAIRLY RELIABLE ARE LESS PROMISING. WILL MAINTAIN AREAS OF MVFR CIGS AROUND SUNRISE OVER THE SW WA LOWLANDS AND ALONG THE COLUMBIA RIVER TO KPDX AND VICINITY. KPDX AND APPROACHES...VFR THROUGH 00Z SUN. HOWEVER...THERE IS A 30 TO 40 PERCENT CHANCE MVFR CIGS DEVELOP OVER THE TERMINAL AND VICINITY AROUND 13Z. ANY LOW CLOUDS THAT FORM WILL DISSIPATE BY 17Z. WEISHAAR && .MARINE...HIGH PRESSURE OVER THE NE PAC HOLDING FIRM...AND WILL PERSIST FOR THE NEXT FEW DAYS. GFS MODEL SEEMS TO BE HANDLING THE SURFACE FEATURES WELL. STILL GETTING GUSTS TO AROUND 25 KT OVER THE WATERS AS OF 03Z. WILL CONTINUE WITH THE CURRENT TIMING OF SMALL CRAFT ADVISORIES. WIND WILL SETTLE DOWN A BIT AFTER 08Z...BUT PICK UP AGAIN SAT AFTERNOON. NAM AND GFS INDICATE 20 TO 25 KT WIND SPEEDS 18Z SAT THROUGH 06Z SUN. MODELS SHOW THE SURFACE RIDGE AXIS A BIT MORE TO THE S SAT AFTERNOON COMPARED TO TODAY. THUS...THE S WA WATERS MAY NOT ACHIEVE SMALL CRAFT ADVISORY SPEEDS. THE LACK OF ANY NOTABLE LONGER PERIOD SWELLS WILL CONTINUE THROUGH THE WEEKEND. EXPECT SEAS TO BE RELATIVELY STEEP AND CHOPPY AS WIND WAVES/FRESH SWELL LOOK TO DOMINATE THROUGH EARLY NEXT WEEK. MODELS INDICATE TIGHTER PRESSURE GRADIENTS ALONG THE WA COAST EARLY NEXT WEEK...RESULTING IN FRESH NW SWELL PUSHING 10 FT BY TUE. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 AM PDT SATURDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 AM PDT SATURDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. && $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
  [top] Area Forecast Discussion National Weather Service Spokane WA 759 PM PDT FRI MAY 30 2014 .SYNOPSIS... The Inland Northwest will undergo a warming trend this weekend. Many areas will warm into the upper 70s to mid 80s. The majority of the region will remain dry through the middle of next week. However, the mountainous regions of north Idaho and northern Washington will see a chance for showers and thunderstorms each afternoon through mid week. && .DISCUSSION... Evening update: Scattered thunderstorm activity that has been mainly be confined to Kittitas and Yakima counties but is starting to drift northward into southern Chelan County. There have not been any strikes observed in Chelan County but a few cells near the crest could still strengthen over the next hour. With the sun setting, the main threat with this activity will transition to isolated showers. Latest HRRR is doing well with the placement of this activity and takes it to the northeast while falling apart upon reaching southern Okanogan County. Consequently, a few light showers are expected to pass through Wenatchee... Waterville Plateau...and eastern reaches of Chelan County over the next few hours then wane by 06z. The next feature of note is a midlevel circulation that came from northern CA and is driving thunderstorms across Central Oregon. Clouds and any shower activity with this feature will spread into SE WA and the lower ID Panhandle between 6-12z. A few light showers will be possible but once again, the threat for thunder is low (not entirely impossible) but too low to differ from the dayshifts thoughts which advertised showers over thunderstorms. I did spread the threat for sprinkles and light showers northward into Pullman/Lewiston and increased cloud cover. This also lead to raising overnight temperatures for most locations south of line from Mullan to La Crosse. /sb && .AVIATION... 00Z TAFS: VFR conditions expected at all forecast sites through 00z Sat. Main weather of concern this period will be two areas with a marginal chance of showers and thunderstorms. The first is over the northern Cascades and Okanogan Highlands between 00-03z. The second is a cluster of elevated convection tracking NE from Oregon overnight expected to bring passing cigs btwn 8-10K ft AGL vcnty KPUW/KLWS. A few -shra will will be possible but confidence is not high. Aft 20z...aftn heating and presence of upper-low over the region will renew the threat for -shra and isold -tsra mainly across the mtns but with the best instability focusing in the ID Panhandle and Blue Mtns...may see a few -shra vcnty KLWS/KPUW. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 50 78 51 79 53 81 / 10 10 10 0 0 10 Coeur d`Alene 48 78 48 78 50 80 / 0 10 10 10 10 10 Pullman 49 77 46 77 48 81 / 10 10 10 0 0 0 Lewiston 55 84 53 84 55 88 / 10 10 10 10 0 0 Colville 45 78 48 80 50 84 / 10 20 10 10 10 10 Sandpoint 45 77 45 78 47 80 / 0 20 20 10 10 10 Kellogg 47 75 48 75 50 80 / 10 30 20 10 10 10 Moses Lake 49 84 52 86 54 88 / 0 0 0 0 0 0 Wenatchee 53 84 59 86 61 88 / 20 10 0 0 0 0 Omak 43 82 51 85 53 87 / 10 10 0 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
255 PM PDT THU MAY 29 2014 .SYNOPSIS...A WEAK UPPER LEVEL TROUGH OF LOW PRES OVER THE PACIFIC NW WILL LINGER INTO THE WEEKEND...BEFORE MOVING E OVER THE WEEKEND. SURFACE HIGH PRES OVER THE NE PACIFIC WILL STRENGTHEN THIS WEEKEND BRINGING AND ONSHORE FLOW THAT WILL LAST THROUGH EARLY NEXT WEEK. && .SHORT TERM...THE UPPER TROUGH SEEN IN WATER VAPOR PICTURES TODAY OVER THE PACIFIC NW IS FORECAST BY MODELS TO LINGER INTO SAT... BEFORE PUSHING OFF TO THE E. DESPITE THE TROUGH...12Z SOUNDINGS AT UIL SLE AND MFR ALL SHOWED A SUBSIDENCE INVERSION BETWEEN 850 MB AND 700 MB THIS MORNING. MODEL SOUNDINGS INDICATE THE SUBSIDENCE TO CONTINUE TO STRENGTHEN A BIT AND LOWER THROUGH TONIGHT. AS LOW LEVEL FLOW TURNS MORE NORTHERLY TONIGHT EXPECT CLOUDS TO BREAK UP FURTHER THIS EVENING...WITH CLOUDS BECOMING A LITTLE MORE CONCENTRATED CLOSER TO THE COAST. NOT A LOT OF MOISTURE EXPECTED TO WORK WITH FRI AND SAT OUTSIDE OF RESIDUAL LOW LEVEL MOISTURE. MODEL SOUNDINGS DO INDICATE MARGINAL INSTABILITY OVER THE CASCADES FRI AFTERNOON AND AGAIN SAT AFTERNOON. POTENTIAL INSTABILITY IS DEEP ENOUGH TO MAINTAIN A SLIGHT CHANCE FOR THUNDERSTORMS OVER THE HIGH CASCADES AND IN TO THE HOOD RIVER VALLEY. GFS AND ECWMF BOTH SHOW A SHORT WAVE ROTATING THROUGH SW WA AND NW OREGON FRI NIGHT...ALTHOUGH LITTLE MOISTURE ACCOMPANIES IT. WILL EXTEND A SLIGHT CHANCE FOR SHOWERS OVER THE CASCADES THROUGH THE LATTER PART OF FRI NIGHT. TEMPS WILL WARM BACK A BIT ABOVE NORMALS FRI IN RESPONSE TO SUBSIDENCE AND WARMING 850 MB TEMPS. THE MAIN TROUGH SHIFTS E SAT NIGHT AND SUN...ALTHOUGH REGION REMAINS UNDER A BROAD CYCLONIC FLOW ON THE BACKSIDE OF THE LOW. STRENGTHENING HIGH PRES OFFSHORE WILL KEEP A MARINE AIR MASS OVER THE REGION THROUGH SUN WITH ONSHORE FLOW. SOME HINTS IN MODELS AT ANOTHER WEAK SHORTWAVE ARRIVING SUN MORNING WHICH COUPLED WITH MARINE MOISTURE WILL KEEP A SLIGHT CHANCE FOR MORNING SHOWERS NEAR THE COAST SUNDAY. .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...A RIDGE OF HIGH PRESSURE WILL REMAIN OFFSHORE NEXT WEEK WITH NORTHERLY FLOW OVER THE REGION. THIS PATTERN WILL BRING SEVERAL DAYS OF DRY WEATHER TO THE REGION NEXT WEEK. TEMPERATURES WILL RUN NEAR NORMAL ALONG THE COAST AND 2 TO 4 DEGREES ABOVE NORMAL INLAND. TW && .AVIATION...VFR CIGS 050-070 WILL CONTINUE THRU 02Z ALONG THE COAST AND N AND CENTRAL WILLAMETTE VALLEY WITH TOPS AROUND 080. SCATTERED CLOUDS OVER THE SOUTHERN VALLEY AND THE CASCADES AND FOOTHILLS IN LANE COUNTY. THESE CLOUDS WILL PROBABLY BECOME SCATTERED OVER MUCH OF THE INLAND AREAS AFTER SUNSET. STRATUS EXPECTED RE FORM OVERNIGHT OVER THE N INTERIOR AND SOUTHWEST WASHINGTON AROUND 020 FOR MVFR CIGS AFTER 12Z. THIS STRATUS WILL LIKELY DISSIPATE LATER BY FRIDAY AFTERNOON. HIGH AND MID CLOUDS EXPECTED TO MOVE DOWN FROM THE NORTH ASSOCIATED WITH AN UPPER TROUGH THAT WILL MOVE SOUTH ON FRIDAY. KPDX AND APPROACHES...VFR WITH SCT-BKN 060 THRU 03Z FRIDAY... BECOMING SCATTERED CLOUDS 060 AFT 21Z. THERE IS A 50% CHANCE OF MVFR CIG AT THE TERMINAL 12Z-18Z. SCHNEIDER && .MARINE...THERMAL TROUGH BEGINNING TO FORM ALONG THE S OREGON COAST THIS AFTERNOON AND WILL STRENGTHEN A LITTLE THIS EVENING. THE THERMAL TROUGH SHIFTS INLAND BY FRIDAY AFTERNOON IN RESPONSE TO AN UPPER LEVEL LOW MOVING SOUTH FROM WASHINGTON AND BRITISH COLUMBIA. THE PRESSURE GRADIENT WILL REMAIN STRONG DURING THE AFTERNOONS ALTHOUGH THE DIRECTION WILL FAVOR MORE OF A WESTNORTHWEST WIND. SINCE WINDS WERE LIGHT TODAY THERE HAS NOT BEEN TOO MUCH OF A WIND WAVE BUT THEY WILL BE INCREASING TONIGHT AND TOMORROW. A NORTHWEST SWELL IS EXPECTED TO ARRIVE TONIGHT AND TOMORROW WHICH WILL INCREASE THE WAVE PERIOD BUT THERE IS NOT MUCH ENERGY IN THIS SWELL SO SIG WAVE HEIGHTS WILL REMAIN BELOW 7 FT. FOR THE REMAINDER OF THE WEEKEND AND EARLY NEXT WEEK THERE WILL BE A HIGH PRESSURE OFFSHORE AND LOW PRESSURE INLAND AND EXPECT SMALL CRAFT WINDS DURING THE AFTERNOON AND EVENING HOURS MOST DAYS. SCHNEIDER && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT FRIDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. && $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion National Weather Service Spokane WA 246 PM PDT THU MAY 29 2014 .SYNOPSIS... Showers and isolated thunderstorms will be confined mainly to the northern mountains this evening as a low pressure system pulls away from the region. Much warmer weather develops Friday and continues into the weekend. Many areas will be in the upper 70s to lower 80s Friday through Wednesday. Most areas will be dry through the middle of next week...shower or thunderstorm development is possible in the mountains each afternoon and evening. && .DISCUSSION... Tonight: Although temperatures are warming aloft with the upper level low pressure system well off to the northeast now, we are still holding onto to some weak surface based instability across the Northeast Mtns. A weak impulse moving through the northwest flow out of BC is triggering a batch of showers near Republic. The HRRR model takes these showers and slides them southeast with time this evening. This will impact the communities of Colville, Metaline Falls and eventually into Sandpoint and Bonners Ferry if they continue to hold together that long. These showers seem to be producing fairly weak updrafts due to only a marginally unstable atmosphere, so not convinced we will see any lightning from these showers through the rest of the afternoon into the evening; however, guidance off of the HRRR and SPC SREF page indicates a slight chance that we could still see a thunderstorm develop up till about 8:00 PM this evening or so. Showers will quickly dissipate over the evening as we lose our daytime heating. Skies will clear out overnight with dew points sitting in the low to mid 30s. Winds will also be light and strong radiational cooling is anticipated to take place overnight. Expect lows tonight to drop into the low to mid 30s across the northern valleys and colder pockets may drop down to freezing; this will include locations such as Republic, Springdale and Republic. With the idea that showers will continue into the evening across the northern mountains, I added patchy fog to the forecast for late tonight into early Friday morning. Friday: We will see a significant rise to temperatures tomorrow of around 8-10 degrees compared to this afternoon. This will begin a warming trend into the weekend. Another upper level disturbance, currently located in northwestern BC, will begin to drop down into the northern WA Cascades by the afternoon. This will result in some developing showers north of the Canadian border in BC and along the Cascade Mtns. These showers may also produce a few thunderstorms; all other areas will likely remain dry. /SVH Fri Nt through Sunday: The entire weekend will be dominated by a slow-moving upper trough...first moving into Ern Wa and N Id Fri Nt, then not exiting into Wrn Montana until late Sunday. This low will weaken slowly in general, and is not showing the magnitude of stretching/strong weakening as model guidance hinted at yesterday. The good new, at least confidence- wise, is that there is much more agreement between guidance versus the previous runs. Even so, there will still be a number of embedded vort maxes within this upper low, each having the potential to enhance localized regions of heavier convective pcpn. But given the lack of notable instability, it`s likely that the pcpn will be dominated by diurnal processes...ie, the vast majority of the pcpn will be confined to the afternoon/early evening and driven mostly by insolation (peak heating) over the elevated heat and moisture sources of the mountain zones. We`ll be watching closely how these embedded vort maxes evolve according to the models, then try to fine tune the fcst to locate the best potential for showers and thunderstorms. bz Sunday evening through Thursday...Longwave trof continues to influence the majority of this time interval. The synoptic features nested in this longwave trof include a parts of a shortwave trof and embedded low along with minor disturbances rotating around its periphery lifting out slowly and clumsily Sunday evening into Monday evening. This may result in relatively low pops depicting the low potential for showers and thunderstorms. Tuesday morning into Tuesday afternoon there is another hint at a shortwave trof dropping down in a northwest to southeast trajectory that may be more of a breezy wind and wind gust maker in addition to having some potential for light precipitationso more wording for showers and thunderstorms remain in various shape or form over North Idaho and over and near the mountainous terrain of Northeast Washington. Wednesday and Thursday the flow over Eastern Washington and North Idaho still remains somewhat trof like in appearance but the ECMWF and GFS differ in timing and passage of northwest to southeast traversing synoptic/mesoscale features through the trof. So all in all there really isn`t a period void of pops or a mention of convection in some shape or form in the forecast area. Since the trof isn`t substantially deep daytime heating and not too much cloud cover to inhibit it should result in forecast temperatures on slightly on the warm side of what would be considered normal for this time of year. /Pelatti && .AVIATION... 18Z TAFS: An upper level low pressure system will begin to exit the region today. Some weak surface based instability will result in a redevelopment of showers this afternoon over the mountains. Isolated thunderstorms will be possible across the northern mountains of eastern WA and in the ID Panhandle, but will not impact the taf sites. All taf locations will see some flat cumulus in the afternoon with VFR conditions expected through 18Z Friday. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 45 74 50 78 51 78 / 10 0 10 10 20 10 Coeur d`Alene 39 75 46 78 51 78 / 10 0 10 20 20 20 Pullman 36 74 45 75 49 76 / 0 0 20 20 20 20 Lewiston 45 81 52 80 54 82 / 0 0 10 20 20 20 Colville 41 75 44 79 49 80 / 20 10 10 10 10 10 Sandpoint 37 74 44 76 46 72 / 10 0 0 10 10 20 Kellogg 41 74 45 76 48 74 / 0 0 10 20 20 30 Moses Lake 44 80 50 83 51 84 / 0 0 0 0 0 0 Wenatchee 50 80 56 82 56 84 / 0 0 0 0 0 0 Omak 41 78 48 81 49 83 / 10 10 10 0 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT FRI MAY 30 2014 .SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT) ISSUED AT 251 PM CDT FRI MAY 30 2014 ON THE CONUS SCALE...WATER VAPOR AND RAP 500MB ANALYSIS SHOW A REX BLOCK PATTERN WITH A CUTOFF LOW ALONG THE TX/OK/AR BORDERS AND A RIDGE OF HIGH PRESSURE SITUATED ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION INTO WESTERN ONTARIO/HUDSON BAY. MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES FOR SATURDAY THROUGH SUNDAY. A DEEP TROUGH OF LOW PRESSURE EXTENDING FROM THE CENTRAL PLAINS OF CANADA TO ALONG THE WEST COAST WAS DIRECTING A PLUME OF TROPICAL MOISTURE/FUEL FOR SCATTERED SHOWERS AND THUNDERSTORMS INTO THE FRONT RANGE OF THE ROCKIES AND INTO THE WESTERN NORTHERN PLAINS. VISIBLE SATELLITE SHOWING CLEAR SKIES ACROSS OUR AREA WITH FIELD OF CUMULUS ACROSS MOST OF IA INTO THE MAJORITY OF MN IN RETURN FLOW AROUND SURFACE HIGH PRESSURE SITUATED OVER THE GREAT LAKES REGION. OTHERWISE...ANOTHER WARM ONE WITH TEMPERATURES ACROSS THE AREA THIS AFTERNOON IN THE 80S. FOR TONIGHT...RIDGE OF HIGH PRESSURE WILL KEEP OUR AREA QUIET AND MOSTLY CLEAR THROUGH MUCH OF THE NIGHT. LOOK FOR SOME INCREASE IN MID/HIGH CLOUD AFTER MIDNIGHT WEST OF THE MISSISSIPPI WITH EASTWARD ADVANCE OF THE TROUGH PUSHING INTO THE NORTHERN PLAINS. LIGHT/CALM WINDS AND CLEAR SKIES WILL LIKELY LEAD TO SOME PATCHY FOG IN THE CRANBERRY BOG COUNTRY OF CENTRAL WISCONSIN AND IN THE WISCONSIN RIVER VALLEY. OTHERWISE...PLAN ON LOWS TONIGHT IN THE LOWER/MIDDLE 50S ACROSS CENTRAL WISCONSIN...TO THE LOWER/MIDDLE 60S WEST OF THE MISSISSIPPI RIVER. ON SATURDAY...MODELS SHOW SURFACE HIGH HOLDING STRONG OVER THE GREAT LAKES WHILE A MID-LEVEL TROUGH AND WEAK SURFACE COLD FRONT ADVANCES EAST ACROSS THE NORTHERN PLAINS. AS A RESULT NAM/GFS/HIRES ECMWF ALL SHOWING MAIN CORRIDOR OF 850MB MOISTURE TRANSPORT REMAINING WEST OF THE AREA WITH THE EASTERN PERIPHERY BRUSHING AREAS WEST OF THE MISSISSIPPI RIVER. THINKING WE WILL SEE A GENERAL INCREASE IN MID- LEVEL ACCAS THROUGH THE DAY BUT HELD ANY SHOWER/THUNDER CHANCES WEST OF THE MISSISSIPPI THROUGH THE DAY. DESPITE INCREASING CLOUD COVER...TEMPERATURES EXPECTED TO TOP OFF IN THE 80-85 DEGREE RANGE WITH SOUTH WINDS OF 10-15 MPH. LOOK FOR A GENERAL UPTICK IN SHOWER/THUNDERSTORM CHANCES SATURDAY NIGHT WITH THE APPROACHING MID-LEVEL TROUGH/SURFACE FRONTAL BOUNDARY FOCUSING BETTER MOISTURE TRANSPORT INTO THE AREA. HIGHEST CHANCES LOOK TO BE NORTH OF THE I-94 CORRIDOR. NOT EXPECTING ANY SEVERE AT THIS POINT WITH 0-3KM MUCAPE ONLY IN THE 500-800J/KG RANGE AND SHEAR WITHIN THIS CAPE LAYER ONLY IN THE 10-15KT RANGE. THINKING WITH PRECIPITABLE WATERS CREEPING UP AROUND 1.5 INCHES...SOME LOCALIZED HEAVY DOWNPOURS COULD OCCUR. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 251 PM CDT FRI MAY 30 2014 FOR SUNDAY THROUGH MONDAY...THERE WILL BE A LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS AS A SURFACE LOW SPINS UP OVER THE CENTRAL PLAINS AND TRACKS NORTHEAST EASTERN MN/NORTHWEST WI. MOST FAVORABLE PERIOD FOR SEVERE WEATHER SEEMS TO BE ON MONDAY AS BOTH THE NAM/GFS PRODUCE A CORRIDOR OF PRE-FRONTAL 0-3KM MUCAPE IN THE 1500-3000J/KG RANGE ALONG WITH 0-3KM BULK SHEAR IN THE 25-35KT RANGE. NAM ALSO SHOWS 700- 500MB LAPSE RATES APPROACHING 7-8C/KM. SO...APPEARS TO BE A WINDOW OF OPPORTUNITY FOR SEVERE THREAT. WE WILL HAVE TO KEEP A CLOSE EYE ON THIS. FOR MONDAY NIGHT INTO TUESDAY...GFS AND ECMWF SHOW DEEPENING SURFACE LOW MOVING NORTH OF THE AREA WITH A DRY SLOT WORKING INTO THE AREA. THIS LOOKS TO SHUT DOWN SHOWER/THUNDER CHANCES AT LEAST FOR AREAS ALONG AND WEST OF THE MISSISSIPPI RIVER...WITH BEST CHANCES BASICALLY CONFINED ALONG AND NORTH OF THE I-94 CORRIDOR. ADJUSTED POPS TO REFLECT THIS. LOOK FOR COOLER AIR OTHERWISE ON BRISK WEST WINDS TUESDAY WITH HIGHS IN THE 70S. FOR THE REMAINDER OF THE PERIOD...WED-FRI...ECMWF AND GFS SHOWING A GENERALLY FLATTENED MID-LEVEL RIDGE ACROSS THE CONUS WITH SEVERAL TROUGHS RIPPLING THROUGH THIS QUASI-HIGH ZONAL FLOW. APPEARS AT THIS POINT THE BEST CHANCES OF RAIN WILL BE ON WEDNESDAY/WEDNESDAY NIGHT AS BOTH MODELS SHOW PRETTY GOOD AGREEMENT IN BRING A FAIRLY STRONG MID-LEVEL TROUGH THROUGH THE AREA. OTHERWISE...LOOKING AT A GENERAL COOLING TREND FOR WEDNESDAY INTO THURSDAY WITH HIGHS WED IN THE 70- 75 DEGREE RANGE AND IN THE MID 60S/LOWER 70S FOR THU. HIGHS LOOK LIKE THEY REBOUND INTO THE UPPER 60S TO MIDDLE 70S ON FRIDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1100 PM CDT FRI MAY 30 2014 FETCH OF LOW LEVEL SATURATION IS HELPING TO PRODUCE AN AREA OF CLOUDS ACROSS WESTERN MN INTO IA....WITH SHOWERS/STORMS PERSISTING OVER WESTERN MN. DRIER AIR ACROSS WI AND EASTERN MN WAS SERVING TO KEEP ANY PCPN...AND MOST OF THE CLOUDS...AT BAY. THE MOISTURE IS PROGGED TO SHIFT EASTWARD ON SATURDAY...AND EXPECT A BKN VFR CIG TO DEVELOP FOR THE AFTERNOON AT KRST/KLSE. MUCH LIKE TODAY...INSTABILITY SHOULD HELP FIRE A FEW SHOWERS/STORMS IN THE MOISTURE FEED...WHICH COULD IMPACT KRST. WILL HOLD WITH VCSH FOR NOW. THIS ACTIVITY WILL WANE WITH THE LOSS OF DAYTIME HEATING. THERE WILL BE AN INCREASING THREAT FOR PCPN OVERNIGHT SAT...AS THE 850 MB LOW LEVEL MOISTURE TRANSPORT STARTS TO SHIFT ACROSS THE REGION...AND A SFC FRONT/UPPER LEVEL SHORTWAVE ENCROACH ON THE UPPER MISSISSIPPI RIVER VALLEY. PERIODS OF SHRA/TS ARE LIKELY FOR SUN- MON...WITH IFR/MVFR CONDITIONS WITH ANY OF THE STORMS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT FRI MAY 30 2014 .SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT) ISSUED AT 251 PM CDT FRI MAY 30 2014 ON THE CONUS SCALE...WATER VAPOR AND RAP 500MB ANALYSIS SHOW A REX BLOCK PATTERN WITH A CUTOFF LOW ALONG THE TX/OK/AR BORDERS AND A RIDGE OF HIGH PRESSURE SITUATED ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION INTO WESTERN ONTARIO/HUDSON BAY. MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES FOR SATURDAY THROUGH SUNDAY. A DEEP TROUGH OF LOW PRESSURE EXTENDING FROM THE CENTRAL PLAINS OF CANADA TO ALONG THE WEST COAST WAS DIRECTING A PLUME OF TROPICAL MOISTURE/FUEL FOR SCATTERED SHOWERS AND THUNDERSTORMS INTO THE FRONT RANGE OF THE ROCKIES AND INTO THE WESTERN NORTHERN PLAINS. VISIBLE SATELLITE SHOWING CLEAR SKIES ACROSS OUR AREA WITH FIELD OF CUMULUS ACROSS MOST OF IA INTO THE MAJORITY OF MN IN RETURN FLOW AROUND SURFACE HIGH PRESSURE SITUATED OVER THE GREAT LAKES REGION. OTHERWISE...ANOTHER WARM ONE WITH TEMPERATURES ACROSS THE AREA THIS AFTERNOON IN THE 80S. FOR TONIGHT...RIDGE OF HIGH PRESSURE WILL KEEP OUR AREA QUIET AND MOSTLY CLEAR THROUGH MUCH OF THE NIGHT. LOOK FOR SOME INCREASE IN MID/HIGH CLOUD AFTER MIDNIGHT WEST OF THE MISSISSIPPI WITH EASTWARD ADVANCE OF THE TROUGH PUSHING INTO THE NORTHERN PLAINS. LIGHT/CALM WINDS AND CLEAR SKIES WILL LIKELY LEAD TO SOME PATCHY FOG IN THE CRANBERRY BOG COUNTRY OF CENTRAL WISCONSIN AND IN THE WISCONSIN RIVER VALLEY. OTHERWISE...PLAN ON LOWS TONIGHT IN THE LOWER/MIDDLE 50S ACROSS CENTRAL WISCONSIN...TO THE LOWER/MIDDLE 60S WEST OF THE MISSISSIPPI RIVER. ON SATURDAY...MODELS SHOW SURFACE HIGH HOLDING STRONG OVER THE GREAT LAKES WHILE A MID-LEVEL TROUGH AND WEAK SURFACE COLD FRONT ADVANCES EAST ACROSS THE NORTHERN PLAINS. AS A RESULT NAM/GFS/HIRES ECMWF ALL SHOWING MAIN CORRIDOR OF 850MB MOISTURE TRANSPORT REMAINING WEST OF THE AREA WITH THE EASTERN PERIPHERY BRUSHING AREAS WEST OF THE MISSISSIPPI RIVER. THINKING WE WILL SEE A GENERAL INCREASE IN MID- LEVEL ACCAS THROUGH THE DAY BUT HELD ANY SHOWER/THUNDER CHANCES WEST OF THE MISSISSIPPI THROUGH THE DAY. DESPITE INCREASING CLOUD COVER...TEMPERATURES EXPECTED TO TOP OFF IN THE 80-85 DEGREE RANGE WITH SOUTH WINDS OF 10-15 MPH. LOOK FOR A GENERAL UPTICK IN SHOWER/THUNDERSTORM CHANCES SATURDAY NIGHT WITH THE APPROACHING MID-LEVEL TROUGH/SURFACE FRONTAL BOUNDARY FOCUSING BETTER MOISTURE TRANSPORT INTO THE AREA. HIGHEST CHANCES LOOK TO BE NORTH OF THE I-94 CORRIDOR. NOT EXPECTING ANY SEVERE AT THIS POINT WITH 0-3KM MUCAPE ONLY IN THE 500-800J/KG RANGE AND SHEAR WITHIN THIS CAPE LAYER ONLY IN THE 10-15KT RANGE. THINKING WITH PRECIPITABLE WATERS CREEPING UP AROUND 1.5 INCHES...SOME LOCALIZED HEAVY DOWNPOURS COULD OCCUR. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 251 PM CDT FRI MAY 30 2014 FOR SUNDAY THROUGH MONDAY...THERE WILL BE A LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS AS A SURFACE LOW SPINS UP OVER THE CENTRAL PLAINS AND TRACKS NORTHEAST EASTERN MN/NORTHWEST WI. MOST FAVORABLE PERIOD FOR SEVERE WEATHER SEEMS TO BE ON MONDAY AS BOTH THE NAM/GFS PRODUCE A CORRIDOR OF PRE-FRONTAL 0-3KM MUCAPE IN THE 1500-3000J/KG RANGE ALONG WITH 0-3KM BULK SHEAR IN THE 25-35KT RANGE. NAM ALSO SHOWS 700- 500MB LAPSE RATES APPROACHING 7-8C/KM. SO...APPEARS TO BE A WINDOW OF OPPORTUNITY FOR SEVERE THREAT. WE WILL HAVE TO KEEP A CLOSE EYE ON THIS. FOR MONDAY NIGHT INTO TUESDAY...GFS AND ECMWF SHOW DEEPENING SURFACE LOW MOVING NORTH OF THE AREA WITH A DRY SLOT WORKING INTO THE AREA. THIS LOOKS TO SHUT DOWN SHOWER/THUNDER CHANCES AT LEAST FOR AREAS ALONG AND WEST OF THE MISSISSIPPI RIVER...WITH BEST CHANCES BASICALLY CONFINED ALONG AND NORTH OF THE I-94 CORRIDOR. ADJUSTED POPS TO REFLECT THIS. LOOK FOR COOLER AIR OTHERWISE ON BRISK WEST WINDS TUESDAY WITH HIGHS IN THE 70S. FOR THE REMAINDER OF THE PERIOD...WED-FRI...ECMWF AND GFS SHOWING A GENERALLY FLATTENED MID-LEVEL RIDGE ACROSS THE CONUS WITH SEVERAL TROUGHS RIPPLING THROUGH THIS QUASI-HIGH ZONAL FLOW. APPEARS AT THIS POINT THE BEST CHANCES OF RAIN WILL BE ON WEDNESDAY/WEDNESDAY NIGHT AS BOTH MODELS SHOW PRETTY GOOD AGREEMENT IN BRING A FAIRLY STRONG MID-LEVEL TROUGH THROUGH THE AREA. OTHERWISE...LOOKING AT A GENERAL COOLING TREND FOR WEDNESDAY INTO THURSDAY WITH HIGHS WED IN THE 70- 75 DEGREE RANGE AND IN THE MID 60S/LOWER 70S FOR THU. HIGHS LOOK LIKE THEY REBOUND INTO THE UPPER 60S TO MIDDLE 70S ON FRIDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 600 PM CDT FRI MAY 30 2014 FETCH OF LOW LEVEL SATURATION IS HELPING TO PRODUCE AN AREA OF CLOUDS AND SCATTERED SHRA/TS ACROSS WESTERN MN INTO IA. DRIER AIR ACROSS WI AND EASTERN MN WAS SERVING TO KEEP ANY PCPN...AND MOST OF THE CLOUDS...AT BAY. THE MOISTURE IS PROGGED TO SHIFT EASTWARD ON SATURDAY...AND EXPECT A BKN VFR CIG TO DEVELOP FOR THE AFTERNOON AT KRST/KLSE. MUCH LIKE TODAY...INSTABILITY SHOULD HELP FIRE A FEW SHOWERS/STORMS IN THE MOISTURE FEED...WHICH COULD IMPACT KRST. WILL ADD A VCSH FOR NOW. THIS ACTIVITY WILL WANE WITH THE LOSS OF DAYTIME HEATING. THERE WILL BE AN INCREASING THREAT FOR PCPN OVERNIGHT SAT...AS THE 850 MB LOW LEVEL MOISTURE TRANSPORT STARTS TO SHIFT ACROSS THE REGION...AND A SFC FRONT/UPPER LEVEL SHORTWAVE ENCROACH ON THE UPPER MISSISSIPPI RIVER VALLEY. PERIODS OF SHRA/TS ARE LIKELY FOR SUN- MON...WITH IFR/MVFR CONDITIONS WITH ANY OF THE STORMS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
309 AM MDT SAT MAY 31 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 308 AM MDT SAT MAY 31 2014 OVERNIGHT CONVECTION CONTINUES AS SMALL PIECES OF ENERGY MOVE THROUGH THE MEAN FLOW ALLOWING SOME QUICK SHOWERS AND WEAK STORMS TO FIRE BEFORE QUICKLY SCOOTING OFF TO THE EAST. THE HRRR IS DOING FAIRLY WELL PICKING UP ON THIS CONVECTION SO FOLLOWED THIS GUIDANCE WITH MOST CONVECTION DYING DOWN NEAR SUNRISE THOUGH AN ODD CELL OR TWO MAY REMAIN...BEFORE PICKING UP AGAIN FROM NOON ONWARDS. PWATS REMAIN HIGH WITH INSTABILITY AND CAPE FAVORING HIGHER ELEVATIONS WITH FORECAST FOLLOWING SUIT. ATTM...MODELS FAVORING THE FLATTOPS AND CENTRAL MTNS BUT EXPECT COVERAGE TO BE A BIT MORE THAN THAT. THOSE AREAS THAT SEE THESE STORMS WILL EXPERIENCE GUSTY OUTFLOW WINDS AND BRIEF HEAVY RAIN. TONIGHT AND SUNDAY...THE WESTERN TROUGH WILL BE SEPARATING FROM THE LEFT COAST THIS EVENING AS THE MAIN UPPER LOW PUSHES INTO THE NORTHERN ROCKIES...PULLING THE BASE OF THE TROUGH INTO THE GREAT BASIN. LARGE SCALE ASCENT AHEAD OF THE TROUGH WILL FOCUS MAINLY TO OUR NORTH. HOWEVER ADDED LIFT WILL COME FROM THE INDIRECT CIRCULATION OF THE SUBTROPICAL JET NOSING INTO UTAH THIS EVENING. ANOTHER ROUND OF NOCTURNAL CONVECTION LOOKS TO PUSH ACROSS OUR CWA WITH THE BETTER FOCUS ACROSS THE NORTH. CLOUDY CONDITIONS WILL KEEP THINGS MILD AGAIN OVERNIGHT AND AS MORE SUNSHINE IS EXPECTED ON SUNDAY...TEMPERATURES WILL RETURN TO WELL ABOVE NORMAL IN THE AFTERNOON. DRIER AIR FILTERS IN AND EXPECT CONVECTION TO BE WANING BY SUNRISE WITH ONLY HIGH BASED WEAK SHOWERS LINGERING IN THE NORTHEAST ON SUNDAY. SNOW MELT WILL CONTINUE ACROSS THE HIGH COUNTRY AND KEEP RIVERS RUNNING STRONG. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 308 AM MDT SAT MAY 31 2014 SUNDAY NIGHT INTO MONDAY...QUIET CONDITIONS ARE EXPECTED DURING THIS TIME PERIOD AS A SUBTROPICAL HIGH CENTERED OVER THE BAJA BULGES NORTHWARD INTO THE 4 CORNERS AREA. THIS EFFECTIVELY CUTS OFF A MOISTURE TAP AND TEMPERATURES WILL RESPOND BY WARMING A FEW DEGREES ON MONDAY AFTERNOON. MODELS IN FAIR AGREEMENT PUSHING THE NEXT PACIFIC LOW INTO CALIFORNIA MONDAY AFTERNOON. THIS WILL BEGIN TO TIGHTEN THE GRADIENT ALOFT AND BRING MORE AFTERNOON BREEZINESS ALONG WITH THE WARMER TEMPERATURES. THE SUBTROPICAL AREA OF HIGH PRESSURE WILL REMAIN SOUTH OF THE FORECAST AREA MONDAY AS A WAVE APPROACHES FROM THE WEST. FORECAST MOISTURE REMAINS LOW WITH LITTLE PRECIP EXPECTED. AS THE WAVE MOVES THROUGH TUESDAY...WINDS ARE EXPECTED TO PICK UP INCREASING FIRE WX CONCERNS AS DRY CONDITIONS WILL BE IN PLACE. AFTER THAT...THE HIGH TO THE SOUTH GETS FLATTENED...AN AREA OF LOW PRESSURE SKIRTS THE US/CANADIAN BORDER LEAVING ERN UT/WRN CO TO DEAL WITH CONTINUED WARM TEMPS AND DRY CONDITIONS. A WEAK WAVE WILL MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY BUT WITH LITTLE UPPER AIR SUPPORT AND MEAGER MOISTURE...AN OCCNL SHOWER/STORM MAY POP UP HERE OR THERE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 308 AM MDT SAT MAY 31 2014 VFR WILL CONTINUE THROUGH 18Z BEFORE ANOTHER ROUND OF SHOWERS AND STORMS FORM OVER THE HIGHER TERRAIN WITH SOME STORMS DRIFTING OVER NEARBY VALLEYS. MTN TAF SITES LOOK TO BE UNDER THE GUN TODAY INCLUDING KEGE...KASE...AND KTEX THOUGH CONFIDENCE IS LOW THAT SHOWERS OR STORMS WILL FORM ON-STATION. GUSTY WINDS AND SOME BRIEF HEAVY RAIN WILL BE MAIN CONCERNS TODAY WITH STORMS THAT FORM. SOME CONVECTION WILL CONTINUE OVERNIGHT. && .HYDROLOGY... ISSUED AT 308 AM MDT SAT MAY 31 2014 WARM TEMPERATURES CONTINUE TO MELT THE SNOWPACK ACROSS THE REGION WITH RIVERS AND STREAMS FORECAST TO REMAIN HIGH OR INCREASE THROUGH EARLY NEXT WEEK. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TODAY MAY CAUSE ADDITIONAL FLOW INCREASES. THE HIGHEST FLOWS ARE OCCURRING IN RIVERS AND STREAMS FROM THE GUNNISON BASIN IN WEST-CENTRAL COLORADO NORTHWARD TO THE WYOMING BORDER AND ACROSS NORTHEAST UTAH. THAT BEING SAID...ALL RIVERS AND STREAMS ACROSS THE FORECAST WILL BE RUNNING FAST AND STRONG THIS WEEKEND INTO NEXT WEEK. VARIOUS FLOOD PRODUCTS REMAIN IN EFFECT FOR THESE CONDITIONS. PAY ATTENTION TO RIVER...CREEK AND STREAM LEVELS AND WATCH FOR DEBRIS BUILDUP. PLEASE USE CAUTION IF YOU PLAN ON BOATING DOWN OR RECREATING NEAR ANY RIVERS OR STREAMS THROUGH EARLY NEXT WEEK. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ SHORT TERM...TGR/15 LONG TERM...15/TGR AVIATION...TGR HYDROLOGY...TGR
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1149 PM CDT FRI MAY 30 2014 .SYNOPSIS... ISSUED AT 336 PM CDT FRI MAY 30 2014 12Z UA ANALYSIS HAS THE CLOSED UPPER LOW OVER THE LOWER MISSISSIPPI VALLEY WITH HIGH PRESSURE OVER THE GREAT LAKES. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOW PLENTY OF DIURNAL CLOUDS WITH CONVECTION FROM SOUTHERN ILLINOIS THROUGH NORTHEAST MISSOURI AND INTO PARTS OF SOUTHERN IOWA. 18Z SFC ANALYSIS HAD HIGH PRESSURE FROM THE GREAT LAKES INTO THE SOUTHERN PLAINS WITH SOME INFERRED WEAK BOUNDARIES OVER THE LOWER MISSISSIPPI AND OHIO VALLEYS. DEW POINTS WERE MAINLY IN THE 60S ACROSS THE MIDWEST AND PLAINS WITH 50S ACROSS THE GREAT LAKES. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 336 PM CDT FRI MAY 30 2014 BASED ON SATELLITE...RADAR...AND RAP TRENDS...THE CONVECTION FROM SOUTHERN ILLINOIS INTO NORTHEAST MISSOURI AND SOUTHERN IOWA WILL NOT MAKE MUCH MORE NORTHERN PROGRESS THROUGH LATE AFTERNOON. THUS AREAS SOUTH OF A KOTM TO KSPI LINE WILL HAVE THE BEST CHANCE OF SEEING ISOLATED TO POSSIBLY SCATTERED STORMS. AFTER SUNSET...THE REMAINING CONVECTION WILL DISSIPATE BY 10-11 PM ALONG WITH THE REMAINING DIURNAL CLOUDS. THE REMAINDER OF THE NIGHT WILL BE QUIET AND DRY. QUIET AND DRY CONDITIONS WILL BE SEEN INITIALLY SATURDAY MORNING ACROSS THE AREA. NEW DIURNAL CLOUDS WILL BEGIN DEVELOPING BY LATE MORNING WITH SOME CONVECTION ACROSS THE FAR WEST BY MID DAY. CONVECTION WILL INCREASE IN AREAL COVERAGE SATURDAY AFTERNOON ACROSS THE WESTERN HALF OF THE AREA AS BETTER MOISTURE MOVES INTO THE AREA. EAST OF THE MISSISSIPPI DRY CONDITIONS ARE EXPECTED SATURDAY AFTERNOON. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 336 PM CDT FRI MAY 30 2014 CONVECTION THAT DEVELOPS ACROSS THE WESTERN HALF OF THE AREA WILL SLOWLY DISSIPATE SATURDAY EVENING WITH SUNSET. MAINLY DRY CONDITIONS ARE EXPECTED FROM LATE SATURDAY NIGHT THROUGH SUNRISE SUNDAY. INCREASING MOISTURE RETURN ON SUNDAY WITH A WEAK DISTURBANCE ALOFT WILL ALLOW NEW CONVECTION TO DEVELOP BY LATE MORNING AND INCREASE IN AREAL COVERAGE DURING THE AFTERNOON HOURS. THIS CONVECTION IS EXPECTED TO CONTINUE INTO SUNDAY EVENING BEFORE DISSIPATING. SUNDAY NIGHT AND INTO MONDAY THE MODELS ARE SUGGESTING AN ORGANIZED THUNDERSTORM COMPLEX DEVELOPING IN EASTERN NEBRASKA AND MOVING EAST. IF CORRECT...THIS THUNDERSTORM COMPLEX WOULD ARRIVE IN THE AREA VERY LATE SUNDAY NIGHT AND MOVE ACROSS THE AREA MONDAY MORNING AS IT DISSIPATES. BOUNDARIES LEFT OVER FROM THIS COMPLEX WOULD THEN PROVIDE THE FOCUS FOR NEW CONVECTION DEVELOPING MONDAY AFTERNOON. MONDAY NIGHT ON... THERE ARE DIFFERENCES AMONG THE MODELS AS TO WHAT WILL OCCUR MONDAY NIGHT THROUGH TUESDAY. THE ECMWF/GEM SUGGEST HIGH PRESSURE BUILDING IN BRINGING AN END TO THE RAIN. THE GFS KEEPS RAIN ACROSS THE AREA. WEIGHING THE STRENGTHS/WEAKNESSES OF THE MODELS AND CONSIDERING THE OVERALL SYNOPTIC PICTURE...THE IDEA OF BRINGING IN A DRYING TREND LATE MONDAY NIGHT AND TUESDAY DOES HAVE MERIT. TUESDAY NIGHT THROUGH FRIDAY...THE MODEL CONSENSUS HAS CHANCE POPS EACH DAY. THE OVERALL SYNOPTIC PICTURE SUGGESTS A POTENTIALLY ACTIVE PATTERN WITH AN EAST/WEST BOUNDARY SETTING UP IN OR CLOSE TO THE AREA. WILL IT RAIN CONTINUOUSLY THE ENTIRE TIME. NO. EACH ROUND OF CONVECTION WILL DICTATE WHERE SUBSEQUENT ROUNDS OF CONVECTION WILL DEVELOP. SO...THERE WILL BE PERIODS OF DRY WEATHER FROM TUESDAY NIGHT THROUGH FRIDAY. ATTEMPTING TO PIN THEM DOWN IS NOT POSSIBLE WHEN DEALING WITH NONLINEAR PROCESSES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1140 PM CDT FRI MAY 30 2014 EAST WINDS WILL CONTINUE TO DRAW DRY LOW LEVEL AIR ACROSS NORTHERN ILLINOIS INTO EAST CENTRAL IOWA TONIGHT KEEPING VFR CONDITIONS IN PLACE. AN AXIS OF MOIST AIR FROM WEST CENTRAL ILLINOIS THROUGH SOUTHEAST IOWA WILL CREATE FAVORABLE CONDITIONS FOR SOME PATCHY FOG. SCT-BKN CIRRUS WILL KEEP THE VSBYS IN THE FOG AROUND 5SM...HOWEVER ANY PROLONGED CLEARING OVERNIGHT COULD ALLOW VISIBILITIES TO LOWER TO IFR. SATURDAY AND SATURDAY NIGHT VFR CONDITIONS WILL PERSIST OVER NORTHERN ILLINOIS AND EAST CENTRAL IOWA. ISOLATED TO SCATTERED LATE AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED AGAIN FROM WEST CENTRAL ILLINOIS INTO SOUTHEAST IOWA. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...08 SHORT TERM...08 LONG TERM...08 AVIATION...DLF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
253 AM MDT SAT MAY 31 2014 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 252 AM MDT SAT MAY 31 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOWS CLOSES LOW STILL IN PLACE OVER SOUTHERN MISSISSIPPI RIVER VALLEY WITH SW FLOW EXTENDING OVER A LONG FETCH FROM THE PACIFIC OCEAN ACROSS THE CENTRAL ROCKIES AND INTO THE NORTHERN GREAT LAKES REGION. A SHORTWAVE TROUGH EMBEDDED WITHIN THE MEAN SW FLOW IS CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE WITH ITS AXIS EXTENDING SOUTH ACROSS OUR CWA. AT THE SURFACE A STATIONARY FRONT IS APPROXIMATELY EXTENDING FROM NORTHCENTRAL NEBRASKA THROUGH EASTERN COLORADO JUST WEST OF THE KS/CO STATE LINE. REGIONAL COMPOSITE RADAR IMAGERY SHOWS A CLUSTER OF ELEVATED SHOWERS/THUNDERSTORMS OVER NEBRASKA EXTENDING SOUTH ACROSS THE EASTERN HALF OF OUR CWA APPROXIMATELY MATCHING THE LEADING EDGE OF THE SHORTWAVE TROUGH AXIS. WE ARE LOOKING AT A PERSISTENT/ACTIVE PATTERN AS SW FLOW CONTINUES TO BRING A SERIES OF STRONG SHORTWAVE TROUGHS ACROSS THE CENTRAL ROCKIES...AND A LONG FETCH OF PACIFIC MOISTURE INTO THE WESTERN PLAINS. ANOMALOUSLY HIGH PWAT VALUES ARE PROGGED TO REMAIN IN PLACE AND TD VALUES GENERALLY AROUND 60F WILL ALSO LINGER. I CANT COMPLETELY RULE OUT SHOWERS/THUNDERSTORMS ALMOST ANY PERIOD...THOUGH MODEL TIMING DOES GENERALLY FAVOR AFTERNOON/EVENING PERIODS...ESPECIALLY ON SUNDAY. WHILE CAPE PROFILES COULD CERTAINLY SUPPORT SEVERE WEATHER JUST ABOUT EVERY PERIOD OF THE SHORT TERM...THE BEST SHEER IS PROGGED FOR SUNDAY/MONDAY...WHEN ORGANIZED SUPERCELLS WILL BE POSSIBLE (MAINLY IN OUR EAST-SOUTHEAST). INCREASING WINDS SUNDAY COULD ACTUALLY APPROACH ADVISORY CRITERIA SUNDAY AFTERNOON (IF NAM SOLUTION WORKS OUT)...HOWEVER THERE IS STILL A LOT OF SPREAD IN THE SURFACE PATTERN. I BUMPED UP POPS/WINDS (ESPECIALLY SUNDAY)...AND ADDED MENTION OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON/EVENING. I CONSIDERED DOING THE SAME FOR MONDAY...HOWEVER I AM LESS CONFIDENT ON MONDAYS PATTERN AT THIS POINT. STILL WORTH MONITORING. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 252 AM MDT SAT MAY 31 2014 SEASONABLE WEATHER PATTERN EXPECTED THROUGH THE REST OF NEXT WEEK. PRECIP CHANCES EXIST MOST DAYS WITH THE BEST CHANCES ON TUESDAY AND THURSDAY. TEMPS WILL BE NEAR TO ABOVE NORMAL UNTIL A COLD FRONT COMES THROUGH MID-WEEK TO DROP TEMPS DOWN TO SLIGHTLY BELOW NORMAL ON THE LARGE SCALE SOUTHWESTERLY FLOW WILL BE PRESENT ACROSS THE REGION TUESDAY AS AN ELONGATED HIGH PRESSURE PERSISTS FROM WEST TEXAS ACROSS NORTHERN MEXICO AND INTO THE PACIFIC. ALL GLOBAL GUIDANCE IS IN SOLD AGREEMENT WITH THIS ASPECT. A WEAK POSITIVELY TILTED TROUGH WILL DEVELOP OVER THE WESTERN CONUS THROUGH NORTHERN CALIFORNIA...AND NUMEROUS SHORTWAVE TROUGHS WILL MOVE ACROSS THE UPPER GREAT BASIN...THROUGH THE CENTRAL/NORTHERN ROCKIES AND INTO THE PLAINS. THE FINE DETAILS OF SPECIFIC SHORTWAVE STRENGTH/TIMING IS NOT CERTAIN...BUT ON THE WHOLE THIS WILL BE A CONTINUATION OF AN ACTIVE WEATHER PATTERN. ON WEDNESDAY A COLD FRONT WILL WORK ITS WAY SOUTH INTO THE REGION BRINGING COOLER AIR IN ITS WAKE...PROBABLY BECOMING A STATIONARY FRONT AND A FOCUS FOR CONVECTION TO FIRE ON LATER IN THE WEEK. TUESDAY COULD BE ONE OF THE HOTTEST DAYS OF THE YEAR SO FAR WITH 850MB TEMPS SOUTH OF I-70 IN THE LOWER TO MID 30S C...WHICH COULD RESULT IN THE HIGHS IN THE MID 90S...AND MAYBE EVEN A FEW LOCATIONS IN THE FAR SOUTH PART OF THE CWA /TRIBUNE AND LEOTI/ APPROACHING TRIPE DIGITS. A STRONG DRYLINE WILL DEVELOP IN EASTERN COLORADO AND PROGRESS EASTWARD DURING THE DAY...SERVING AS A FOCUS FOR AFTERNOON CONVECTION. LARGE SCALE LIFT WILL BE BEST ALONG/NORTH OF I-70...THOUGH MID-LEVEL MOISTURE COULD BE A PROBLEM DESPITE DEW POINTS NEAR 60 AHEAD OF THE DRYLINE. SHEAR IS QUITE IMPRESSIVE LATE TUESDAY WHICH COULD LEAD TO STRONG/SEVERE STORMS. HAVE SOME CONCERN ABOUT CAP HOLDING AS WELL AS AFOREMENTIONED MOISTURE LIMITATIONS SO WILL KEEP POPS SUB-50 PERCENT FOR NOW. WEDNESDAY A COLD FRONT DIPS IN FROM THE NORTH BRINGING COOLER TEMPS. SOME BUST POTENTIAL FOR HIGHS DEPENDING ON TIMING...HIGHS COULD BE ANYWHERE FROM THE MID 70S TO LOW 90S. WEDNESDAY NIGHT INTO THURSDAY DEVELOPING SHORTWAVE TROUGH IN COLORADO MOVING NORTHEAST COULD PROVIDE ENOUGH LIFT FOR SHOWERS/STORMS TO DEVELOP ALONG/NORTH OF THE FRONT. LIMITED CAPE WILL PREVENT STRONG T-STORMS. CHANCE FOR RAIN INCREASES THURSDAY WITH ABUNDANT LOW LEVEL MOISTURE ADVECTING IN FROM THE EAST SUFFICIENT LARGE-SCALE ASCENT. PWATS AROUND AN INCH AND SLOWER STORM MOTIONS COULD RESULT IN LOCALLY HEAVY RAINFALL. CHANCE FOR STORMS CONTINUES INTO FRIDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1135 PM MDT FRI MAY 30 2014 SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING OUT OF THE GLD AREA AND INTO THE MCK AREA. CONDITIONS AT GLD SHOULD REMAIN VFR AS SHOWERS DISSIPATE AFTER 08Z. CLOUD COVER WILL GO FROM BROKEN TO SCATTERED AFTER 16Z WITH GUSTY SOUTH WINDS EXPECTED DURING THE AFTERNOON AND AN INCREASE IN CLOUDINESS AFTER AFTER 21Z. MCK SHOULD REMAIN VFR WITH A POSSIBILITY OF CONDITIONS GOING TO MVFR WITH LOWER CEILINGS AND VISIBILITY IF THUNDERSTORMS ARE ABLE TO PERSIST AND A HEAVIER RAIN SHOWER MOVES ACROSS THE TAF SITE. EXPECT MOSTLY CLOUDY SKIES TO REMAIN THROUGH THE DAY WITH GENERALLY LIGHT SOUTH WINDS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JJM AVIATION...LOCKHART
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
400 AM EDT SAT MAY 31 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 400 AM EDT SAT MAY 31 2014 07Z SFC ANALYSIS SHOWS HIGH PRESSURE EASING INTO NORTHEAST KENTUCKY BRINGING A DRIER AIR MASS TO THAT PART OF THE STATE. ON SATELLITE...A WISP OF HIGH CLOUDS REMAINS OVER THIS TRANSITION ZONE BETWEEN THIS DRIER AIR AND THE MORE HUMID CONDITIONS TO THE SOUTHWEST. TEMPERATURES ARE A BIT COOLER IN THE NORTHEAST...TOO...BUT MAINLY A RIDGE TO VALLEY DIFFERENCE IS NOTED THERE AND TO A LESSER EXTENT OVER THE REST OF THE CWA. MOISTURE VARIES MORE BROADLY WITH LOW TO MID 60S DEWPOINTS FOUND TO THE SOUTH AND WEST OF JKL WHILE MID 50S ARE MOVING INTO THE NORTHEAST. WINDS ARE LIGHT AND VARIABLE ACROSS THE CWA THIS NIGHT. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A RIDGE OF HIGH PRESSURE OVER THE WESTERN OHIO VALLEY SOUTHEAST TO THE ATLANTIC COAST WHILE ONE DEEP CLOSED LOW IS MOVING AWAY TO THE NORTHEAST OF KENTUCKY AND ANOTHER WEAKER ONE FILLING OVER THE WEST CENTRAL GULF COAST. IN TIME...THE RIDGE SETTLES OVER EAST KENTUCKY KEEPING ALL THE ENERGY NORTH AND WEST OF EAST KENTUCKY. THE RIDGE DOES WEAKEN QUICKLY... THOUGH...AS IT SINKS TO THE SOUTHEAST ON SUNDAY. THIS SHOULD BE ENOUGH TO ALLOW A BIT MORE MID LEVEL ENERGY TO SEEP INTO KENTUCKY BY SUNDAY EVENING. GIVEN THE GOOD MODEL AGREEMENT HAVE FOLLOWED THE SPECIFICS FROM THE NAM12 AND HRRR MOST CLOSELY FOR THE SHORT TERM PORTION OF THE FORECAST. SENSIBLE WEATHER WILL FEATURE PATCHY VALLEY FOG...LOCALLY DENSE... BURNING OFF BY MID MORNING SETTING THE STAGE FOR A SUNNY...QUIET... AND WARM DAY UNDER RIDGING ALOFT AND SFC HIGH PRESSURE. A FEW MORE CLOUDS WILL ARRIVE LATER TONIGHT AS MOISTURE SEEPS BACK IN FROM THE SOUTHWEST. FOR SUNDAY THERE WILL BE A POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS BY EVENING WITH THE BETTER CHANCES OVER THE CUMBERLAND VALLEY. OTHERWISE...WARM AND INCREASINGLY HUMID WEATHER WILL CLOSE OUT THE WEEKEND. USED THE BCCONSSHORT/ALL AS A STARTING POINT FOR TEMPERATURES... DEWPOINTS AND WINDS. DID MAKE ADJUSTMENTS TO THESE TONIGHT FOR MORE OF A RIDGE TO VALLEY TEMP SPLIT. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF MOS GUIDANCE FOR LATER SUNDAY THROUGH THE CWA...OTHERWISE KEPT THEM IN THE SINGLE DIGITS. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 340 AM EDT SAT MAY 31 2014 LOOKS TO BE A FAIRLY ACTIVE PATTERN...WITH A LOT OF DIURNALLY DRIVEN CONVECTION DURING THE EXTENDED. STARTING AT 0Z MONDAY...KY WILL FIND ITSELF BETWEEN AN UPPER LEVEL RIDGE MOVING OFF THE SE COAST...AND A LOW OVER LOUISIANA CONTINUING SOUTHWARD INTO THE GULF. BEING WEDGED BETWEEN THE TWO...THE FLOW ACROSS KY WILL FEATURE WARM MOIST SOUTHERN AIR OFF THE GULF. A STRONG COLD FRONT WILL ALSO STRETCH FROM THE SOUTHERN PLAINS INTO THE UPPER GREAT LAKES REGION...WITH DECENT LIFT AND A LARGE PRECIP SHIELD. DIURNAL HEATING DURING THE DAY SUNDAY WILL BRING CONVECTION TO MUCH OF THIS MOISTURE CONVEYOR BELT FROM THE GULF TO THE COLD FRONT TO OUR NE. THIS INCLUDES SHOWERS AND THUNDERSTORMS FOR MUCH OF WESTERN AND PORTIONS OF CENTRAL KY. HOWEVER...EACH MODEL RUN HAS A SLIGHTLY DIFFERENT SOLUTION FOR EASTERN KY...BEING ON THE EASTERN FRINGE OF THE BEST CONVECTION. EXPECT BY 0Z MONDAY...THIS CONVECTION WILL BE ONGOING BUT DYING OUT WITH LOSS OF DAYTIME HEATING. RAISED POPS BOTH SUNDAY /SHORT TERM/ AND SUNDAY EVENING FROM PREVIOUS. THE REST OF THE NIGHT WILL FEATURE HUMID CONDITIONS BUT DYING CONVECTION...WITH ANOTHER RAMP UP FOR AFTERNOON CONVECTION POSSIBLE DURING THE DAY MONDAY. CONVECTION WILL BE AIDED BY THE FACT THAT THE COLD FRONT WILL HAVE SHIFTED SEWARD...EDGING SLIGHTLY CLOSER TO THE OHIO RIVER VALLEY...AND ALLOWING THE BEST MOISTURE FLOW TO SHIFT SLIGHTLY EASTWARD AS WELL...PUTTING MUCH OF KY INTO THE MOIST UNSTABLE FLOW. BY 12Z TUESDAY...THE FRONT WILL BEGIN TO TRAVERSE THE STATE...BRINGING LIKELY POPS INTO EASTERN KY BY AFTERNOON. MODEL SOLUTIONS ON THE EXACT TIMING OF ENTRANCE AND EXIT ARE STILL SOMEWHAT LACKING...BUT EXPECT A FAIRLY GOOD LINE OF SHOWERS AND THUNDERSTORMS TO PASS THROUGH DURING THE PEAK OF THE AFTERNOON...THEN GET CUT OFF BY DRY AIR BEHIND THE FRONT AND LOSS OF DIURNAL HEATING OVERNIGHT. LATEST MODEL GUIDANCE IS PICKING UP ON WHAT APPEARS TO BE A SECONDARY FRONT DEVELOPING AND FOLLOWING IN THE FOOTSTEPS OF ITS PREDECESSOR...BRINGING YET ANOTHER BOUGHT OF CONVECTIVE PRECIP TO THE REGION WEDNESDAY. OVERALL MODEL UNCERTAINTY OF TIMING AND SET UP WILL LEAD TO STICKING CLOSE TO THE ALLBLEND SOLUTION FROM THIS POINT FORWARD. ANOTHER...WEAKER LOW WILL PASS THROUGH SOMETIME THURSDAY. AT THIS POINT...BOTH THE GEM AND ECMWF SHOW THE MAIN LOW AND PRECIP MOVING JUST NORTH OF KY...WITH SOME WARRANTED SLIGHT CHANCE POPS ACROSS THE NORTHERN CWA. HOWEVER...THE GFS...WHICH THE ALLBLEND LEANS MORE HEAVILY ON...SHOWS THIS LOW PASSING THROUGH THE STATE...AND BRINGING A GOOD DUMP OF PRECIP ONCE MORE THURSDAY MORNING AND THROUGH THE DAY. REGARDLESS...AFTERNOON HEATING AND PROXIMITY TO INSTABILITY AND MOISTURE INFLUX SHOULD BE ENOUGH TO SPAWN SOME SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON SO KEPT WITH THE CHANCE POPS THAT WERE GIVEN. A SIMILAR SITUATION WILL OCCUR ON FRIDAY AS ANOTHER SHORTWAVE DEVELOPS. THE TRACK OF THE SHORTWAVE...THOUGH STILL RATHER UNDETERMINED...WILL MAKE THE DIFFERENCE BETWEEN WIDESPREAD RAIN AND THUNDERSTORMS FRIDAY INTO SATURDAY...OR MORE DIURNALLY DRIVEN SCATTERED CONVECTION. ONCE AGAIN...CONFIDENCE WARRANTS LEANING TOWARDS THE ALLBLEND SOLUTION FOR THE END OF THE EXTENDED. WITH NO DRASTIC CHANGES IN THE OVERALL UPPER LEVEL PATTERN DURING THE EXTENDED...EXPECT TEMPERATURES TO REMAIN RATHER UNIFORM. HIGHS SHOULD REACH THE LOW TO MID 80S DURING THE AFTERNOON...AND DROP INTO THE 60S OVERNIGHT. KEPT WITH A DIURNAL TEMPERATURE CURVE THROUGH THE EXTENDED...AS EVEN THE IMPACTING FRONTS SHOULD CORRELATE WITH THE DIURNAL CYCLE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 210 AM EDT SAT MAY 31 2014 GENERALLY VFR IS EXPECTED FOR THE PERIOD ACROSS THE CWA. THERE WILL BE SOME MVFR OR LOWER VALLEY FOG INTO EARLY SATURDAY MORNING...MAINLY FROM SOUTH AND WEST OF JKL WHERE THE DEWPOINT DEPRESSIONS ARE THE SMALLEST. SOME VALLEY AIRPORT LOCATIONS SUCH AS I39...W38...AND K1A6 COULD GET DOWN TO AIRPORT MINS. THE FOG SHOULD LIFT AND DISSIPATE BY AROUND 13Z...WITH NOTHING MORE THAN A FEW PASSING HIGH CLOUDS THROUGH THE REST OF THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS GRAY ME
355 AM EDT SAT MAY 31 2014 .SYNOPSIS... A TROUGH OF LOW PRESSURE LINGERS OVER THE REGION TODAY PRODUCING SCATTERED SHOWERS. HIGH PRESSURE STRENGTHENS OVER NEW ENGLAND SUNDAY AND MONDAY. A WARM FRONT MOVES INTO THE REGION MONDAY NIGHT. LOW PRESSURE PASSES THROUGH SOUTHERN CANADA TUESDAY AND WEDNESDAY DRAGGING A FRONT INTO NEW ENGLAND MIDWEEK. && .NEAR TERM /TODAY/... WEAK TROUGH OF LOW PRESSURE REMAINS OVER NORTHERN NEW ENGLAND THIS MORNING WITH LATEST MSAS ANALYSIS SHOWING THE MESOLOW CENTER NEAR MOOSEHEAD LAKE. LATEST HRRR FORECAST HAS THIS FEATURE DRIFTING WESTWARD THROUGH THE MORNING WITH A FEW SHOWERS BREAKING OUT WITH THE HELP OF OROGRAPHIC LIFT AND ALSO OFFSHORE AND NEAR BOSTON... WHICH IS ALREADY OCCURRING. AS DAYTIME HEATING INCREASES ... MORE SHOWERS WILL ERUPT OVER THE FOOTHILLS AND HIGHER TERRAIN WITH CHANCE COVERAGE OVER ALL OF NEW HAMPSHIRE THROUGH EARLY AFTERNOON BEFORE FORCING DISAPPEARS. SAID FORCING IS THE SHORT WAVE ENERGY CURRENTLY OVER SOUTHERN QUEBEC THAT WILL SERVE TO CUT OFF THE UPPER LOW JUST OFFSHORE. THE TROUGH WILL WASH OUT WITH SKIES BECOMING MOSTLY SUNNY THIS AFTERNOON. TEMPERATURES WILL REACH THE UPPER 60S AREAWIDE. && .SHORT TERM /TONIGHT AND SUNDAY/... CONTINENTAL HIGH PRESSURE SHIFTS IN FROM THE NORTH TONIGHT AND DEW POINTS AND WINDS TAKE A NOSE DIVE. PW VALUES DROP TO ABOUT THE 15% PERCENTILE. THIS WILL NOT ONLY FOSTER CONDITIONS FOR FOG BUT ALSO FROST. THE HIGHER TERRAIN AS WELL AS FAVORED LOW SPOTS WILL DROP BELOW FREEZING. FROST WILL LIKELY BE WIDESPREAD ENOUGH FOR FROST ADVISORIES TO BE ISSUED FOR MUCH OF THE NORTH COUNTRY. THIS WILL BE ADDRESSED IN THE NEXT FORECAST PACKAGE LATER TODAY. ELSEWHERE LOWS WILL BOTTOM OUT INTO THE UPPER 30S TO MID 40S. SUNDAY WILL START OUT CHILLY BUT THE DRY AIRMASS WILL ALLOW TEMPERATURES TO CLIMB QUICKLY INTO THE MID TO UPPER 70S AREAWIDE BY THE AFTERNOON. NO PRECIPITATION IS FORECAST WITH HIGH PRESSURE CONTINUING TO STRENGTHEN. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... UPPER RIDGE OVER THE NORTHEAST BEGINS TO BREAK DOWN A BIT AND SURFACE HIGH PRESSURE SHIFTS TO THE SOUTH. THIS WILL BRING A WESTERLY FLOW TO NORTHERN NEW ENGLAND... ADVECTING WARM AIR INTO THE AREA. SHOULD SEE TEMPERATURES WARMING INTO THE UPPER 70S AND LOW 80S EVEN CLOSER TO THE COAST ON MONDAY. LATE IN THE DAY ON MONDAY SOME SHOWERS MAY PUSH INTO THE NORTHERN PART OF THE AREA AS A SHORTWAVE TROUGH CROSSES OVER THE TOP OF THE RIDGE AND DOWN INTO MAINE. UPPER TROUGH MOVING OUT OF THE NORTHERN PLAINS AND INTO THE GREAT LAKES WILL GRADUALLY EXERT ITS INFLUENCE OVER NEW ENGLAND WEATHER. BY TUESDAY... SURFACE WINDS WILL SHIFT TO THE EAST OR SOUTHEAST... BRINGING A COOLER MARINE INFLUENCE ESPECIALLY TO THE EAST OF THE MOUNTAINS. SO IN SPITE OF WARMER TEMPERATURES STILL EXISTING ALOFT... THE WARM AIR WILL NOT BE FULLY FELT AT THE SURFACE ACROSS MOST OF MAINE AND EASTERN NEW HAMPSHIRE. HIGHS WILL ONLY REACH THE 60S. FURTHER WEST... MID TO UPPER 70S ARE EXPECTED. WITH THE SURFACE LOW TRACKING WELL TO THE NORTH TOWARD JAMES BAY IN CANADA... AN OCCLUDED FRONT WILL TRY TO PUSH EASTWARD INTO THE FORECAST AREA. THIS WILL LEAD TO A GREATER CHANCE OF SHOWERS ON TUESDAY. THERE WILL LIKELY EXIST A CORRIDOR OF INSTABILITY JUST AHEAD OF THE FRONT ALLOWING FOR THE DEVELOPMENT OF THUNDERSTORMS AS WELL. UPPER TROUGH AXIS REMAINS TO THE WEST OF THE AREA... WITH SEVERAL EMBEDDED SHORTWAVE TROUGHS EXPECTED TO BRING A CHANCE FOR SHOWERS TO THE REGION FOR WEDNESDAY AND THURSDAY. SHOULD SEE A LITTLE IMPROVEMENT BY FRIDAY AS THE UPPER TROUGH FINALLY SHIFTS EAST. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM...PATCHY DENSE FOG THIS MORNING WILL LIFT LATER THIS MORNING SIMILAR TO YESTERDAY. GUSTY N TO NE WINDS WILL DEVELOP BY MID MORNING. EXPECT ANOTHER ROUND OF DENSE FOG SUNDAY MORNING. LONG TERM...GENERALLY VFR UNTIL MONDAY NIGHT WHEN A MOIST EAST OR SOUTHEAST FLOW MAY BRING LOWER CLOUDS BACK INTO THE AREA. IFR CONDITIONS ARE POSSIBLE WITH SOME IMPROVEMENT POSSIBLE DURING THE DAY TUESDAY. SHOWERS AND A MOIST ONSHORE FLOW ON TUESDAY AND WEDNESDAY WILL MAINTAIN A THREAT FOR MVFR OR IFR CONDITIONS. && .MARINE... SHORT TERM...NO FLAGS ON THE WATERS. LONG TERM...HIGH PRESSURE OVER THE WATERS KEEPS CONDITIONS FAIRLY TRANQUIL. FLOW EVENTUALLY TURNS TO THE SOUTH BY TUESDAY BUT SHOULD REMAIN BELOW ADVISORY LEVELS. WAVE MODELS CONTINUE TO SHOW 5+ FT SWELLS MOVING INTO THE GULF OF MAINE SUNDAY NIGHT AND MONDAY LIKELY ASSOCIATED WITH LOW PRESSURE WELL TO THE SOUTHEAST. HOWEVER... THERE IS CONSIDERABLE DOUBT THAT WAVE HEIGHTS WILL BE THIS HIGH. EVEN SO... THE LONG PERIOD WILL LIKELY MAKE THE IMPACT OF THESE WAVES FAIRLY MINOR AND AN ADVISORY WILL NOT LIKELY BE NEEDED. && .FIRE WEATHER...LIGHT PRECIPITATION IS POSSIBLE TODAY...MOSTLY OVER THE MOUNTAINS AND FOOTHILLS THIS MORNING AS A TROUGH OF LOW PRESSURE MOVES WEST. LIGHT WINDS AND RECENT RAIN SHOULD KEEP FIRE WEATHER CONCERNS LOW. HIGH PRESSURE BUILDS OVER THE REGION SUNDAY BRINGING DRIER CONDITIONS TO THE REGION. MINIMUM RH VALUES DROP TO NEAR 25-35% BY THE AFTERNOON AS TEMPERATURES REACH THE MID TO UPPER 70S. WINDS WILL BE LIGHT. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ HANES/KIMBLE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1129 PM CDT Fri May 30 2014 .SHORT TERM: (Through Tonight) Issued at 328 PM CDT Fri May 30 2014 Scattered thunderstorms have had more coverage this afternoon than yesterday. These storms are occurring in an axis of 925-850mb moisture convergence that shows up well in the latest runs on of the RAP. Still expect the storms to gradually diminish early this evening as the RAP shows the aforementioned low level forcing weakening at the same time we will lose daytime heating. Expect the rest of the night to be mainly dry with the potential for some patchy fog toward morning. MOS lows in the mid-upper 60s still look reasonable given current dewpoints. Britt .LONG TERM: (Saturday through Next Friday) Issued at 328 PM CDT Fri May 30 2014 This discussion is probably starting to sound like a broken record, but once again, not much change from the prev forecast. Thru the weekend, expect much of the same as the past couple of days. TSRA will develop mid to late morning and continue into the evening before dissipating. Have therefore continued a persistence forecast thru the weekend for POPs and temps. Mdls are in good agreement bringing a cdfnt into the region on Mon as an upper trof ejects into the Plains as the upper ridge finally breaks down. This fnt shud bring TSRA to portions of the area. Latest mdls suggest stronger upper forcing further swd than the prev couple of days. Have therefore continued higher POPs as more than enuf moisture and heating shud be available for convective development. Did not spread the likely POPs too much further S due to uncertainty of how far the fnt will drift S given the better forcing remaining further N. Mdl solns begin diverging much beyond Mon and have continued a fairly persistent forecast for temps for now. Have also kept POPs in the low to mid chance range due to differences among mdl solns. Tilly && .AVIATION: (For the 06z TAFs through 06z Saturday Night) Issued at 1125 PM CDT Fri May 30 2014 MVFR fog will be the main hazard overnight, especially where rainfall occurred on Friday afternoon/evening. Otherwise, widely scattered thunderstorms are expected to develop during the heat of the day again on Saturday. Specifics for KSTL: Only a trace of rain was reported at KSTL today, so not real excited about fog developing at the terminal. Will see a repeat on Saturday with showers and thunderstorms developing after 18Z. Light southeast wind to continue. CVKING && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
413 AM CDT SAT MAY 31 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 413 AM CDT SAT MAY 31 2014 MAIN FORECAST CHALLENGES FOR THE NEAR TERM WILL BE PLACEMENT OF REDEVELOPING RAIN SHOWERS AND THUNDERSTORMS TODAY. CURRENT ACTIVITY HAS WEAKENED OR SHIFTED TO THE EAST AS H850 LLJ TURNS MORE WESTERLY AND WEAKENS BY 12Z. THE MAIN SFC BOUNDARY IS GENERALLY OVER THE FAR SOUTHEAST ALTHOUGH THERE IS SOME WEAK SFC CONVERGENCE OVER RED LAKE ND WESTERN POLK COUNTY...BUT THE MAIN FORCING OVER THE CENTRAL AND NORTHERN VALLEY WILL BE MID LEVEL FRONTOGENESIS. OVERALL MODELS TARGET SERN HALF OF CWA BUT EXACT PLACEMENT OF PRECIP IS STILL QUITE VARIABLE. THROUGH 18Z...GENERALLY WILL FOLLOW THE 4KM WRF AND A MODEL BLEND FOR THE AFTERNOON AND TONIGHT. TODAY...CONVECTIVE ACTIVITY OVER NORTHEASTERN SD WILL GRADUALLY SPREAD ACROSS THE SOUTHERN VALLEY AND UP INTO WADENA...POLK...OTTER TAIL AND GRANT COUNTIES. DO EXPECT DRY AREA ALONG AND SOUTHEAST OF A CARRINGTON-LAKOTA- CAVALIER LINE TO FILL IN THIS MORNING...ESPECIALLY OVER SOUTHEASTERN ND...AS BAND OF MID LEVEL FG FORCING SHIFTS EAST (AND AREA OF CONVECTION LIFTS NORTH). HOWEVER THIS ACTIVITY WILL GENERALLY BE WEAK AND BEST CHANCE FOR MODERATE RAIN SHOWERS AND CONVECTION WILL BE ACROSS THE SOUTHEAST WHERE THERE REMAINS SOME LLJ INFLUENCE. BEYOND 18Z MODELS VARY ON PLACEMENT OF PRECIP. OVERALL PREFER A GFS/ECMWF BLEND WHICH KEEPS THE DEVILS LAKE BASIN AND NORTHERN VALLEY FAIRLY DRY. TONIGHT...MODELS CONTINUE TO DRY OVER NORTHWESTERN HALF OF CWA AND CHALLENGE WILL BE PLACEMENT OF MODERATE RAINFALL AS MODELS CONTINUE TO VARY ON LOCATION. GFS ACTUALLY DRIES OUT MOST OF AREA IN THE 06Z TO 12Z TIMEFRAME WHEREAS THE NAM IS QUITE BULLISH OVER MY EAST CNTRL ZONES AND THE GEM/ECMWF CONTINUE TO TARGET THE SOUTHEAST. EXPECT THE MAIN ACTIVITY...HOWEVER...TO SHIFT EASTWARD OUT OF THE CWA BY 12Z SUNDAY. SUNDAY...THE NEXT WAVE OF SHOWERS AND THUNDERSTORMS WILL BEGIN TO LIFT NORTH AS A SECOND UPPER WAVE MOVES ACROSS THE DAKOTAS. WILL LIKELY SEE A BREAK ACROSS MUCH OF THE AREA EARLY SUNDAY...WITH SHOWERS THEN LIFTING NORTH AND EAST OUT OF THE CNTRL DAKOTAS SUN AFTN. OVERALL TWO TO THREE INCHES OF RAINFALL IS POSSIBLE ACROSS THE SOUTHEASTERN ZONES BY THE TIME THIS SECOND WAVE MOVES OUT ON MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 413 AM CDT SAT MAY 31 2014 SUN NIGHT AND MONDAY...SECOND WAVE OF SHOWERS SPREAD ACROSS EASTERN DAKOTAS AS ANOTHER UPPER WAVES MOVES INTO NORTHERN TIER FROM THE SW. SURFACE LOW MOVES OVER MINNESOTA WITH INVERTED TROUGH EXTENDING ACROSS THE NORTHERN VALLEY...KEEPING PRECIP GOING ACROSS MAINLY THE NORTHERN CWA AND LOWER CHANCES ACROSS THE SOUTH. THE NAMDNG GUIDANCE IS GOING SIGNIFICANTLY COOLER ACROSS NORTHEASTERN ND MON...WITH DAYTIME HIGHS IN THE MID 50S. WITH MODERATE TO HEAVY RAIN SHOWERS POSSIBLE ALONG THE INVERTED TROUGH...COULD SEE RAINFALL IMPACT TEMPS TO THAT DEGREE AND WILL TREND TEMPS DOWN BUT NOT QUITE THAT DRASTIC YET AS MODELS STILL DIFFER ON EXACT PLACEMENT OF PRECIP FOR DAY 3. MON NIGHT...HIGH PRESSURE WILL FINALLY WORK ITS WAY INTO THE WRN DAKOTAS AND WE SHOULD SEE PRECIP ACROSS THE EASTERN DAKOTAS DISSIPATE EARLY IN THE EVENING. BOTH THE NAM AND GEM ARE QUICKER (GEM IS THE FASTEST) IN ENDING PRECIP ACROSS THE DAKOTAS WHILE THE GFS/ECMWF HOLD ON THROUGH MIDNIGHT. SHOWALTERS BEGIN TO INCREASE SIGNIFICANTLY ACROSS ALL BUT MY SOUTHEAST...SO CHANGED PREDOMINANT PRECIP TYPE TO RAIN SHOWERS WITH ISOLATED TSTMS. LOOK FOR ACTIVITY TO DECLINE ACROSS THE EASTERN PORTION OF THE CWA BETWEEN 06Z AND 12Z TUESDAY. FOR TUE THROUGH FRI NIGHT...IT SHOULD DRY OUT ON TUE WITH A FEW LINGERING SHOWERS/STORMS IN THE FAR EAST MAINLY TUE MORNING. IT SHOULD BE DRY TUE NIGHT THROUGH WED NIGHT IN ALL AREAS. BY THU AND FRI...A MORE ACTIVE PATTERN COULD ONCE AGAIN DEVELOP...WITH THE CHANCES FOR SHOWERS AND STORMS. TEMPS SHOULD BE NEAR NORMAL WITH A COOLER AIRMASS THAN WE HAVE HAD OVER THE PAST WEEK OR SO. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1136 PM CDT FRI MAY 30 2014 SIMILAR TO THE LAST SET OF TAFS...ATTEMPTED TO PROVIDE DETAIL TO THE FIRST 6-9 HOURS...WITH JUST A GENERAL FORECAST AFTER 9 HOURS. THERE WILL BE A BREAK IN PRECIP WITH SHOWER/THUNDER CHANCES INCREASING SATURDAY MORNING. AT 04Z...THERE WAS AN AREA OF LIFR CONDITIONS JUST WEST OF THE VALLEY...AND SOUTH OF THE DVL BASIN. KDVL IS NOW INDICATING FEW004...AND ANTICIPATE A PERIOD OF IFR CONDITIONS FOR KDVL BEFORE SUNRISE (THE LATEST RAP GUIDANCE AGREES). WILL NEED TO MONITOR IF THESE CONDITIONS ADVECT INTO THE VALLEY SITES...AT THIS POINT THAT PROBABILITY APPEARS LOW. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...SPEICHER LONG TERM...DK/SPEICHER AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1136 PM CDT FRI MAY 30 2014 .UPDATE... ISSUED AT 955 PM CDT FRI MAY 30 2014 LOOKING AT THE CONUS RADAR IMAGERY THREE DISTINCT AREAS OF RAINFALL ARE OBSERVED...WITH ONE OVER THIS FA...ANOTHER IN SOUTH DAKOTA...AND ANOTHER IN WESTERN NEBRASKA. EACH OF THESE AREAS LIKELY ASSOCIATED WITH AN UPPER WAVE WITHIN THE SOUTHWEST FLOW ALOFT. EACH OF THESE WAVES WILL AFFECT THE REGION OVER THE NEXT 24-36 HOURS. RAINFALL AMOUNTS OF OVER AN INCH ARE BEGINNING TO BECOME MORE WIDESPREAD...WITH THE 2-5 INCH AMOUNTS REMAINING ISOLATED. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 343 PM CDT FRI MAY 30 2014 THIS EVENING INTO EARLY SATURDAY MORNING...THUNDERSTORMS SHOULD CONTINUE ALONG AND NORTH OF A SFC FRONTAL BOUNDARY WHICH STRETCHES FROM THE LAKE OF THE WOODS THROUGH EAST CENTRAL ND INTO THE BLACK HILLS OF SOUTH DAKOTA. SURFACE HEATING AHEAD OF THE BOUNDARY HAS REACHED WELL INTO THE MIDDLE 80S AND EVEN LOWER 90S ACROSS SERN ND AND WEST CENTRAL MN WITH DEWPOINTS INTO THE MIDDLE 60S ACROSS A BROAD OF THE NORTHERN PLAINS...AND EDGING NORTHWARD INTO THE CENTRAL RED RIVER BASIN. VISIBLE SAT IMAGERY SHOWS CLOUD STREETS FEEDING NORTHWARD ACROSS EASTERN SD AND SOUTHERN MN AND INTO THE LOW LVL MOISTURE CONVERGENCE BAND ALONG THE FRONTAL BOUNDARY ...WITH PRECIPITABLE WATER PUSHING 1.0 TO 1.5 INCHES. ONGOING ELEVATED TSTMS SHOULD CONTINUE TRACKING NORTHEASTWARD FROM WESTERN SD INTO ERN ND AND NORTHWEST MN THROUGH THE EVENING AND OVERNIGHT... WHILE DEEPER SFC BASED CONVECTION STEADILY FILLS IN EAST OF THE FRONT THROUGH SERN ND AND WEST CENTRAL MN. SURFACE TO 2 KM VGP VALUES APPROACH .2 TO .3 ACROSS SERN AND EAST CENTRAL ND FROM LATE AFTERNOON INTO EARLY EVENING WHERE THE GREATEST THREAT FOR SUPERCELL TSTM DEVELOPMENT EXISTS. A FEW STORMS MAY PRODUCE LARGE HAIL THOUGH HEAVIER RAINFALL AND LOW TILT STORMS WILL ACT TO REDUCE THE OVERALL HAIL THREAT. A MID-UPPER LEVEL DIVERGENCE IS EXPECTED TO INCREASE OVERNIGHT AS A MID LEVEL SHORT WAVE LIFTS THROUGH THE AREA... WITH RAINFALL CONTINUING INTO SATURDAY MORNING. EXPECT WIDESPREAD AREAS OF AN INCH OR GREATER RAINFALL WITH ISOLATED AREAS OF 2 INCHES OR MORE THROUGH SATURDAY MORNING. SATURDAY AND SATURDAY NIGHT...EXPECT THE FRONTAL BOUNDARY TO SHIFT FURTHER EASTWARD THROUGH THE DAY ON SATURDAY...WITH BOTH ELEVATED AND SURFACE BASED CONVECTION AGAIN EXPECTED TO FIRE FROM THE AFTERNOON INTO THE EVENING. THE AXIS OF HEAVIER RAINFALL SHUD SHIFT OVER SERN ND AND FURTHER INTO WEST CENTRAL AND NORTH CENTRAL MN BY SATURDAY EVENING. PWATS ON SATURDAY SHUD AGAIN APPROACH 1.5 INCHES SO THAT AREA RAINFALL OF AN INCH OR GREATER ARE LIKELY... MAINLY ALG AND EAST OF A BAUDETTE-FOSSTON-GWINNER LINE. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 343 PM CDT FRI MAY 30 2014 SUNDAY AND MONDAY...EXPECT SOME BREAK IN THE RAIN ON SUNDAY BEFORE LOW PRESSURE SYSTEM LIFTS ACROSS THE AREA SUNDAY EVENING INTO MONDAY. THIS SYSTEM COULD BRING A THIRD ROUND OF RAINFALL ACROSS THE AREA... WITH SOMEWHAT LOWER RAINFALL AMOUNTS POSSIBLE. TUESDAY THROUGH FRIDAY...RELATIVELY HIGH AMPLITUDE LONG WAVE RIDGE/TROUGH OVER EASTERN PACIFIC/PACIFIC NORTHWEST BECOMES ZONAL BY DAY 7. ALSO LONG WAVE FLOW BECOMES MORE ZONAL ACROSS THE NORTHERN PLAINS THROUGH THE PERIOD. THE GFS WAS THE FAST SOLUTION. THE DGEX AND NAM WERE STRONGER AND SLOWER SOLUTIONS, AND THE ECMWF WAS THE SLOWEST SOLUTION AT 84 HOURS. HOWEVER WITH THE NORTHERN STREAM THE ECMWF WAS FASTER THAN THE GFS. ECMWF APPEARS TO BE SHIFTING NORTH WITH SOUTHERN STREAM AND SHIFTING SOUTH WITH NORTHERN STREAM. THE GFS HAS BEEN SHIFTING NORTH WITH NORTHERN STREAM OVER THE LAST COUPLE MODEL RUNS. WILL PREFER THE ECMWF TO START AND THE GFS AT THE END OF THE PERIOD. DECREASED POPS FOR TUE. WILL TRIM BACK POPS IN FAR WESTERN ZONES FOR TUE NIGHT. WILL TRIM BACK POPS NORTH AND EAST WED AND WED NIGHT. HIGH TEMPS INCREASED A DEGREE OR SO FOR TUE AND DECREASED ONE, TWO, AND THREE DEGREES FOR WED, THU, AND FRI RESPECTIVELY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1136 PM CDT FRI MAY 30 2014 SIMILAR TO THE LAST SET OF TAFS...ATTEMPTED TO PROVIDE DETAIL TO THE FIRST 6-9 HOURS...WITH JUST A GENERAL FORECAST AFTER 9 HOURS. THERE WILL BE A BREAK IN PRECIP WITH SHOWER/THUNDER CHANCES INCREASING SATURDAY MORNING. AT 04Z...THERE WAS AN AREA OF LIFR CONDITIONS JUST WEST OF THE VALLEY...AND SOUTH OF THE DVL BASIN. KDVL IS NOW INDICATING FEW004...AND ANTICIPATE A PERIOD OF IFR CONDITIONS FOR KDVL BEFORE SUNRISE (THE LATEST RAP GUIDANCE AGREES). WILL NEED TO MONITOR IF THESE CONDITIONS ADVECT INTO THE VALLEY SITES...AT THIS POINT THAT PROBABILITY APPEARS LOW. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...GUST LONG TERM...HOPPES AVIATION...TG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
408 AM EDT SAT MAY 31 2014 .SYNOPSIS... HIGH PRESSURE THROUGH THE WEEKEND. MOISTURE INCREASES MONDAY. COLD FRONT TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG MAINLY ALONG PROTECTED RIVER VALLEYS WILL LIFT QUICKLY DURING THE EARLY MORNING HOURS. HIGH PRESSURE AT THE SFC AND ALOFT WILL STAY IN CONTROL THRU TONIGHT...PROVIDING MOSTLY CLEAR SKIES...MILD AFTERNOONS...AND COOL NIGHTS. WITH WEAK EASTERLY FLOW AND ASSOCIATED DOWN SLOPING WARMING OVER THE WESTERN SLOPES...EXPECT WARM TEMPERATURES TODAY REACHING INTO THE LOW TO MID 80S. NIGHT WILL COOL DOWN DUE TO RADIATIONAL COOLING IN THE ABSENCE OF CLOUDS UNDER WEAK OR CALM FLOW. SOME LOW LEVEL CLOUDS WILL DEVELOP OVER THE FAVORABLE EASTERN MOUNTAINS NEARBY BKN UNDER EASTERLY FLOW. BLENDED THE ALL BLEND CONSENSUS GUIDANCE WITH THE MET NUMBERS FOR TEMPERATURES THROUGH THE PERIOD. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... QUIET AT THE OUTSET OF THE SHORT TERM PERIOD ON SUNDAY WITH UPPER RIDGE OVERHEAD AND SFC HIGH PRESSURE CENTERED OVER THE MID-ATLANTIC COAST REGION. INHERITED MAX TEMPS SUNDAY APPEAR ON TRACK...WITH HIGHS RANGING FROM GENERALLY LOWER/MID 80S FOR THE LOWLANDS...TO THE UPPER 60S FOR THE HIGHEST ELEVATIONS OF THE EASTERN MOUNTAINS. AXIS OF RETURN LLVL MOISTURE AROUND THE AFOREMENTIONED SFC HIGH CONTINUES TO INCH CLOSER TO THE AREA. DID NUDGE SKY COVER UP JUST A LITTLE TO REFLECT A GENERAL PARTLY CLOUDY SKY FOR MANY BY THE AFTERNOON HOURS. THE ONLY REAL CHANGE FROM PREV FCST WAS TO INSERT AN ISOLATED SHOWER/STORM MENTION ACROSS THE FAR WESTERN ZONES OF NE KY AND EXTREME SE OHIO FOR JUST A FEW HOURS ROUGHLY 20Z SUN - 00Z MON. THOUGH THE LACK OF AN APPARENT TRIGGERING MECHANISM IS THE WILDCARD...WITH GOOD ML CAPE VALUES OF 1000-1400 J/KG AND PWATS UP TO 1.20-1.30 IN THIS AREA...CAN`T OPERATIONALLY SAY THAT AN ISOLATED SHOWER OR STORM IS NOT POSSIBLE. ALSO...STORM MOTION IS TO THE NORTHEAST...SO IT`S FEASIBLY POSSIBLE THAT SOMETHING WHICH FORMS FURTHER WEST OR SW OVER EASTERN KENTUCKY MAKES IT INTO THE TRI-STATE AREA BEFORE RUNNING OUT OF STEAM. BUT AGAIN...THE VAST MAJORITY OF FOLKS WILL SEE MOSTLY SUNNY TO PARTLY CLOUDY SKIES ON SUNDAY AND REMAIN DRY. && .LONG TERM /TUESDAY THROUGH FRIDAY/... COLD FRONT SINKS INTO THE AREA ON TUESDAY WITH LIKELY POPS. MODELS THEN BEGIN TO DIFFER...WITH ECMWF TAKING FRONT WELL OUT OF CWA...WHILE GFS DROPS IT JUST SOUTH...BUT THEN BRINGS IT BACK NORTH AS SURFACE LOW CROSSES KANSAS. BASED ON TYPICAL SUMMER WEATHER PATTERN IN THE APPALACHIANS...TEND TO THINK THE OSCILLATING FRONT OF THE GFS IS THE BETTER SOLUTION...BUT WITH MODEL UNCERTAINTY...STAYED CLOSE TO WPC FOR THE END OF THE PERIOD. BLENDED WPC TEMPS INTO PREVIOUS FORECAST THROUGH THE LONG TERM. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL CONTINUE IN CONTROL OF THE WEATHER CONDITIONS PROVIDING MOSTLY CLEAR SKIES THROUGH LATE SATURDAY. THE EXCEPTION COULD BE OVER THE EASTERN MOUNTAINS WHERE EASTERLY FLOW CLOUD SQUEEZE SOME MOISTURE AGAINST THE MOUNTAINS TO PRODUCE MVFR LOW LEVEL STRATUS TO ALSO AFFECT BKN OVERNIGHT INTO SATURDAY MORNING. CLEAR SKIES...CALM SFC WINDS...AND BOUNDARY LAYER WINDS LESS THAN 15 KNOTS PER THE NAM AND RAP MODELS SUGGEST RADIATIONAL COOLING WILL LIKELY TAKE PLACE DROPPING TEMPERATURES BELOW THE CROSSOVER TEMPERATURES. CONSEQUENTLY...LIKE THE IDEA OF KEEPING IFR CONDITIONS UNDER DENSE FOG CONFINED ALONG THE DEEPER PROTECTED VALLEYS SUCH AS CRW...EKN AND CKB TOWARDS 12Z. OTHERWISE...MVFR/VFR MIST CONDITIONS WILL BE POSSIBLE AT MOST PLACES THROUGH 12-13Z. WIDESPREAD VFR CONDITIONS EXPECTED SATURDAY MORNING AFTER 13Z. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: ONSET AND INTENSITY OF RIVER AND VALLEY FOG TONIGHT...AND MVFR CEILINGS ON EAST FACING SLOPES OF THE SOUTHERN AND CENTRAL MOUNTAINS...COULD 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. DATE SAT 05/31/14 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 M H H H H H H HTS CONSISTENCY M M M M M H H H H H H H BKW CONSISTENCY M M H H H H H H H H H H EKN CONSISTENCY L L L L L M H H H H H H PKB CONSISTENCY M M M M M H H H H H H H CKB CONSISTENCY M M M M M H H H H H H H AFTER 06Z SUNDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/50 NEAR TERM...ARJ SHORT TERM...50 LONG TERM...MZ AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
151 AM EDT SAT MAY 31 2014 .SYNOPSIS... HIGH PRESSURE THROUGH THE WEEKEND. MOISTURE INCREASES MONDAY. COLD FRONT TUESDAY. && .NEAR TERM /THROUGH TODAY/... PREVIOUS FORECAST REMAINS ON TRACK. NO UPDATES NECESSARY PREVIOUS DISCUSSION BELOW... LATEST RADAR MOSAIC AND SURFACE OBSERVATIONS INDICATE A BOUNDARY WAS PUSHING WESTWARD INTO OUR MOUNTAIN COUNTIES. EAST OF THE BOUNDARY...WINDS BECOME NE/E...TEMPERATURES FALL AND DEWPOINTS RISE ABOUT 5 TO 10 DEGREES. IN ADDITION...SCT TO BKN LOW CLOUDS WERE SEEN. CURRENT THINKING IS THAT THIS BOUNDARY WILL CONTINUE TO PUSH WEST...JUST NOT SURE HOW FAR WEST IT WILL GO. THE EASTERLY WINDS WILL RESULT IN THE MOIST COOL AIR FLOWING UP THE EASTERN SLOPES... WITH INCREASING CLOUDS FOR THAT PORTION OF THE FORECAST AREA. FORECAST IS GENERALLY IN SYNC WITH THIS THINKING...SO ONLY TWEAKS WERE MADE. OUTSIDE OF THE MOUNTAINS...FORECAST IS ON TRACK AND DO NOT SEE ANY REAL NEED TO MAKE ANY REAL CHANGES. PREVIOUS DISCUSSION... OTHER THAN JUST AN AFTERNOON SHOWER TODAY OVER EXTREME SOUTHWEST VIRGINIA WITH THE SOUTHWARD EXITING FRONT AND DEEP MOISTURE...ITS HIGH PRESSURE IN CONTROL THRU SATURDAY WITH DRIER AIR AND LOTS OF SUNSHINE. EVEN THOUGH HIGH PRESSURE CENTERED OVER EASTERN CANADA RIDGES DOWN OVER THE OHIO AND MID ATLANTIC STATES WITH SOME COOL ADVECTION IN THE GENERALLY EAST FLOW...AN INVERTED SURFACE TROUGH AND DOWNSLOPING WEST OF THE MOUNTAINS ALONG WITH ABUNDANT SUNSHINE WILL ALLOW TEMPERATURES TO REBOUND INTO THE 80S FOR THE LOW LANDS SATURDAY. BUT IT WILL BE COOLER AT NIGHT WITH THE DRIER AIR...LACK OF CLOUDS...AND LIGHT WINDS THAT WILL ALLOW TEMPS TO FALL WELL DOWN INTO THE 50S...WITH PERHAPS SOME RIVER AND VALLEY FOG AGAIN LATER TONIGHT. ONE EXCEPTION TO THE MOSTLY CLEAR SKIES TONIGHT MAY BE THE LIGHT AND STILL MOIST LOW LEVEL EAST FLOW THAT COULD BRING IN SOME LOWER CLOUDS ON EAST FACING SLOPES OF THE CENTRAL AND SOUTHERN MOUNTAINS...BUT SHOULD BREAK UP RATHER QUICKLY SATURDAY MORNING. && .SHORT TERM /TONIGHT THROUGH MONDAY/... UPPER LEVEL RIDGE REMAINS OVER EASTERN CONUS THROUGH THE SHORT TERM PERIOD. A SURFACE HIGH PRESSURE SYSTEM GRADUALLY SINKS SOUTH ALONG THE EASTERN SEABOARD SUNDAY INTO MONDAY. AS THIS HAPPENS LOW LEVEL WINDS TURN FROM EASTERLY SATURDAY NIGHT TO SOUTHERLY BY SUNDAY NIGHT...WITH MOISTURE BEGINNING TO INCREASE. THAT COMBINED WITH DAYTIME HEATING AND A WEAK SHORTWAVE TROUGH CRESTING THE UPPER RIDGE LEAD TO A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS ON MONDAY. ONLY MINOR CHANGES MADE TO TEMPS THROUGH THE PERIOD BY BLENDING IN BIAS CORRECTED ECMWF TO HIGHS AND BIAS CORRECTED CONSENSUS GUIDANCE FOR LOWS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... COLD FRONT SINKS INTO THE AREA ON TUESDAY WITH LIKELY POPS. MODELS THEN BEGIN TO DIFFER...WITH ECMWF TAKING FRONT WELL OUT OF CWA...WHILE GFS DROPS IT JUST SOUTH...BUT THEN BRINGS IT BACK NORTH AS SURFACE LOW CROSSES KANSAS. BASED ON TYPICAL SUMMER WEATHER PATTERN IN THE APPALACHIANS...TEND TO THINK THE OSCILLATING FRONT OF THE GFS IS THE BETTER SOLUTION...BUT WITH MODEL UNCERTAINTY...STAYED CLOSE TO WPC FOR THE END OF THE PERIOD. BLENDED WPC TEMPS INTO PREVIOUS FORECAST THROUGH THE LONG TERM. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL CONTINUE IN CONTROL OF THE WEATHER CONDITIONS PROVIDING MOSTLY CLEAR SKIES THROUGH LATE SATURDAY. THE EXCEPTION COULD BE OVER THE EASTERN MOUNTAINS WHERE EASTERLY FLOW CLOUD SQUEEZE SOME MOISTURE AGAINST THE MOUNTAINS TO PRODUCE MVFR LOW LEVEL STRATUS TO ALSO AFFECT BKN OVERNIGHT INTO SATURDAY MORNING. CLEAR SKIES...CALM SFC WINDS...AND BOUNDARY LAYER WINDS LESS THAN 15 KNOTS PER THE NAM AND RAP MODELS SUGGEST RADIATIONAL COOLING WILL LIKELY TAKE PLACE DROPPING TEMPERATURES BELOW THE CROSSOVER TEMPERATURES. CONSEQUENTLY...LIKE THE IDEA OF KEEPING IFR CONDITIONS UNDER DENSE FOG CONFINED ALONG THE DEEPER PROTECTED VALLEYS SUCH AS CRW...EKN AND CKB TOWARDS 12Z. OTHERWISE...MVFR/VFR MIST CONDITIONS WILL BE POSSIBLE AT MOST PLACES THROUGH 12-13Z. WIDESPREAD VFR CONDITIONS EXPECTED SATURDAY MORNING AFTER 13Z. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: ONSET AND INTENSITY OF RIVER AND VALLEY FOG TONIGHT...AND MVFR CEILINGS ON EAST FACING SLOPES OF THE SOUTHERN AND CENTRAL MOUNTAINS...COULD 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. DATE SAT 05/31/14 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY M M M L L L L M H H H H HTS CONSISTENCY H M M M M M M H H H H H BKW CONSISTENCY L M M M H H H H H H H H EKN CONSISTENCY M L L L L L L M H H H H PKB CONSISTENCY H M M M M M M H H H H H CKB CONSISTENCY H M M M M M M H H H H H AFTER 06Z SUNDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JSH/ARJ/JMV/MZ NEAR TERM...JSH/JMV SHORT TERM...MZ LONG TERM...MZ AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
201 AM EDT SAT MAY 31 2014 .SYNOPSIS... A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE NORTHEAST THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHEAST LATE IN THE WEEKEND. THIS HIGH PRESSURE MOVE OFFSHORE BY MIDWEEK...WHILE MOISTURE INCREASES OVER OUR AREA FROM THE WEST. && .NEAR TERM /THROUGH TODAY/... AS OF 2 AM...AREA OF SHOWERS BLOSSOMED ACROSS THE NORTHWEST NC PIEDMONT EARLIER...AND ARE GRADUALLY OOZING THEIR WAY SOUTH ALONG THE I-77 CORRIDOR. POPS HAVE BEEN INCREASED SUBSTANTIALLY (TO 50-70 PERCENT) IN THESE AREAS. MESOSCALE MODELS INDICATE GRADUAL DIMINISHMENT OF INTENSITY AND COVERAGE OF SHOWERS THIS MORNING...SO CHANCE POPS WILL BE LIMITED TO THE EASTERN 1/3 OR SO OF THE AREA. 1015 PM UPDATE...CONVECTION HAS STEADILY WANED ACRS THE FA EXCEPT FOR A CLUSTER OF CELLS WHICH HAVE CONTINUED TO BUBBLE ALONG A LINE FROM THE NW CORNER OF NC SEWD INTO THE PIEDMONT TRIAD. THIS SEEMS TO BE THE FRONT...PER SFC OBS AND MSLP ANALYSIS. WHILE COVERAGE REMAINS RATHER STEADY WITHIN THE CLUSTER...EACH NEW GENERATION APPEARS TO BE WEAKER THAN THE LAST. HRRR NOW REDEVELOPS ACTIVITY OVER THE I-77 CORRIDOR OVERNIGHT WHILE THE NEW RUN JUST COMPLETED OF OUR LOCAL WRF-ARW DROPS ACTIVITY STEADILY SWD THRU THE ERN HALF OF THE FA OVERNIGHT AND INTO TMRW MRNG. THESE SCENARIOS ARE PLAUSIBLE THOUGH I WONDER HOW MUCH INSTABILITY IS REALLY LEFT GIVEN ALL THE ACTIVITY EARLIER. I HAVE MAINTAINED THE SCHC OVERNIGHT THROUGHOUT THE AREA. AS OF 230 PM FRI...ONE IS HARD-PRESSED TO IDENTIFY THE REMAINS OF A SURFACE BOUNDARY THAT SHOULD BE STRUNG OUT NW TO SE ACROSS THE WESTERN CAROLINAS...SUCH THAT IT IS HARD TO SAY IF THIS FEATURE WILL EVEN PLAY ANY ROLE IN ORGANIZING ANY ELEVATED CONVECTION OVERNIGHT. OVER THE NEXT 24 HOURS...SUBTLE CHANGES ARE NOTED AT MID AND UPPER LEVELS...WHILE THE PATTERN DOES NOT CHANGE SUBSTANTIALLY. THE MODELS WANT TO KEEP SOME COVERAGE PARTICULARLY NEAR THE BLUE RIDGE OWING TO A WEAK UPSLOPE FLOW AT LOW LEVELS...SO THE FCST RETAINS AT LEAST A SLIGHT CHANCE IN THE SOUTHEASTERLY UPSLOPE FAVORED AREAS THROUGH SATURDAY MORNING. THE MODELS DO A MORE CONCERTED EFFORT IN IDENTIFYING A SW TO NE GRADIENT OF MOISTURE ACROSS THE FCST AREA ON SATURDAY THAT REPRESENTS WHAT IS LEFT OF THE FRONT. THAT SHOULD LEAD TO SOME IDENTIFIABLE DIFFERENCES IN THE WEATHER BETWEEN NE GEORGIA AND WESTERN SC...WHICH SHOULD HAVE ANOTHER DAY MUCH LIKE TODAY...TO THE WESTERN PIEDMONT OF NC WHICH SHOULD HAVE A STRONGER NE WIND ADVECTING COOLER AND DRIER AIR THAT WILL GREATLY INHIBIT CONVECTION AND KEEP TEMPS BELOW NORMAL. && .SHORT TERM /TONIGHT THROUGH MONDAY/... AT 230 PM EDT FRIDAY...ON SATURDAY EVENING AN UPPER RIDGE WILL EXTEND FROM GA AND THE CAROLINAS...TO THE GREAT LAKES...WHILE AN UPPER LOW WILL BE OVER SE TX...AND A MUCH DEEPER UPPER LOW WILL BE WELL OFF THE NEW ENGLAND COAST. THE UPPER RIDGE PROGRESSES VERY SLOWLY TO THE EAST COAST BY MONDAY...WHILE THE UPPER LOW OVER TX FILLS...AND THE ATLANTIC UPPER LOW REMAINS NEARLY STATIONARY. A SLOW MOVING COLD FRONT WILL MOVE ACROSS THE SAVANNAH RIVER VALLEY SATURDAY NIGHT...WITH SUBSTANTIAL MOISTURE BEHIND IT. AN EASTERLY LOW LEVEL FLOW COMPONENT IN THE WAKE OF THE FRONT WILL KEEP MOIST UPSLOPE LIFT OVER THE SOUTHERN BLUE RIDGE...SUPPORTING CONTINUING PRECIPITATION THERE....WHILE LINGERING INSTABILITY ALONG THE BOUNDARY ITSELF SUPPORTS PRECIPITATION IN THE SAVANNAH RIVER VALLEY. THE FRONT MOVES FARTHER INTO GA ON SUNDAY...HIGH PRESSURE ALONG THE EASTERN SEABOARD WILL PUSH DRIER AIR SOUTHWEST INTO THE PIEDMONT OF THE CAROLINAS. LINGERING MOISTURE WILL STILL SUPPORT CLOUD COVER AND PRECIPITATION IN THE SAVANNAH RIVER VALLEY AND OVER THE MUCH OF THE MOUNTAINS...THOUGH INSTABILITY WILL BE MUCH LESS WITH COOLER SURFACE AIR MOVING IN. MOISTURE STARTS TO SPREAD EAST AGAIN ON SUNDAY NIGHT AND MONDAY AS SURFACE HIGH PRESSURE MOVES FROM THE EASTERN SEABOARD TO OFF THE CAROLINA COAST...ALLOWING WARM MOIST ADVECTION FORM THE GULF TO REACH NE GA AND THE WESTERN CAROLINAS. POPS WILL BE ALLOWED TO SPREAD EAST AS A RESULT...AND INCREASING INSTABILITY WILL BE MORE SUPPORTIVE OF CONVECTION ON MONDAY. TEMPERATURES WILL TREND DOWNWARD AS THE COOLER AIR MASS SETTLE IN...UNTIL MONDAY...WHEN WARM ADVECTION ENSUES IN SOUTHERLY FLOW ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AT 230 PM EDT FRIDAY...THE EXTENDED FORECAST WILL FEATURE A DEAMPLIFIED PATTERN...WITH A FLAT UPPER RIDGE OVER THE SOUTHEAST... AND MOORE OR LESS ZONAL FLOW TO THE NORTH. WEAK HIGH PRESSURE WILL BE CENTERED OFF THE CAROLINA COAST ON TUESDAY...WHILE THE REMNANTS OF A COLD FRONT CROSS THE APPALACHIANS FROM THE WEST. RESIDUAL MOISTURE ASSOCIATED WITH A FRONTOLYTIC ZONE OVER THE SOUTHERN APPALACHIANS WILL SUPPORT PRECIPITATION LONG BEFORE THE FRONT ARRIVES. THE SLOW MOVING BOUNDARY LEAVES THE AREA BY EARLY WEDNESDAY...HOWEVER DRYING BEHIND IT IS SOMEWHAT LIMITED...AND MODEL SOUNDINGS SHOW INSTABILITY AND LOW LEVEL MOISTER PERSISTING IN SUBSEQUENT DAYS. TEMPERATURES WILL RUN NEAR MID SUMMER NORMALS. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AT KCLT...AN AREA OF SHOWERS DEVELOPING NORTH OF THE TERMINAL ARE LIKELY TO PASS OVER THE AIRFIELD AT TIMES OVER THE NEXT FEW HOURS... AND A TEMPO FOR SUCH HAS BEEN INTRODUCED. TOYED WITH THE NOTION OF ADDING AN IFR VISBY TO THE TEMPO...BUT SHOWERS ARE TRENDING DOWN IN INTENSITY...SO HAVE OPTED FOR MVFR FOR THE TIME BEING. DID INCLUDE A TEMPO FOR AN IFR CIG BETWEEN 09-12Z THIS MORNING...AS IMPROVING EASTERLY FLOW IN THE VICINITY OF A WEAK BACK DOOR COLD FRONT SHOULD BRING IN AREA OF IFR CIGS OVER CENTRAL NC TOWARD KCLT BY SUNRISE. OTHERWISE...DRIER/MORE STABLE AIR IS EXPECTED OVER THE AREA BY THIS AFTERNOON...AND WHILE A STRAY SHOWER CANNOT BE RULED OUT... CONVECTION SHOULD GENERALLY REMAIN SOUTHWEST OF THE NC PIEDMONT. WINDS ARE EXPECTED TO REMAIN LIGHT NE THROUGH THE PERIOD. ELSEWHERE...ANOTHER NIGHT OF CONSIDERABLE FORECAST UNCERTAINTY OWING TO VERY MOIST ENVIRONS WITHIN A REGIME MARKED BY VERY SUBTLE FEATURES. HAVE GENERALLY GONE WITH AN MVFR FORECAST AT MOST TERMINALS...BUT WITH GENEROUS USE OF TEMPOS FOR IFR/LIFR IN LOCATIONS WHERE HEAVY RAIN OCCURRED FRIDAY (KHKY/KGSP/KAND). IN FACT...KHKY HAS ALREADY DEVELOPED A LIFR CIG...AND WOULD NOT BE SURPRISED IF THIS REMAINS THROUGH THE NIGHT...OWING TO A WEAK E/SE UPSLOPE FLOW. HOWEVER...DIDN/T HAVE THE CONFIDENCE TO INCLUDE CATEGORICAL OCCURRENCE. AT KAND/KGSP...STUCK WITH A 2SM WITH SCT LIFR CLOUDS WITHIN A TEMPO...BUT WOULD NOT AT ALL RULE OUT PERIODS OF LIFR CIGS. OTHERWISE...SHOWERS WILL PASS NEAR KHKY FOR THE NEXT FEW HOURS...BUT ARE NOT EXPECTED TO IMPACT THE TERMINAL. MORE STABLE/DRIER AIR IS EXPECTED TO AFFECT KHKY AND SURROUNDING AREAS LATER THIS MORNING...AND SCATTERED AFTERNOON CONVECTION SHOULD BE LIMITED TO LOCATIONS NEAR THE UPSTATE SC AND NC MOUNTAIN TERMINALS...WHERE VCTS HAS BEEN INTRODUCED. OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH DAY... WITH MORNING RESTRICTIONS POSSIBLE. CONFIDENCE TABLE... 06-12Z 12-18Z 18-24Z 00-06Z KCLT HIGH 85% HIGH 90% HIGH 100% HIGH 100% KGSP HIGH 87% HIGH 97% HIGH 92% HIGH 81% KAVL MED 75% HIGH 80% HIGH 98% HIGH 95% KHKY MED 73% MED 77% HIGH 100% HIGH 100% KGMU HIGH 86% HIGH 85% HIGH 89% HIGH 85% KAND HIGH 100% HIGH 84% HIGH 85% HIGH 91% 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...JAT NEAR TERM...JDL/PM/WIMBERLEY SHORT TERM...JAT LONG TERM...JAT AVIATION...JDL
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
235 AM EDT SAT MAY 31 2014 .SYNOPSIS... A BACKDOOR COLD FRONT WILL CONTINUE TO PUSH SOUTHWESTWARD TONIGHT...MOVING SOUTH OF THE FORECAST AREA BY SATURDAY. COOLER...MORE STABLE MARITIME AIR BEHIND THE FRONT WILL RESULT IN LESS SHOWER AND THUNDERSTORMS INTO THE WEEKEND AS HIGH PRESSURE BUILDS OVER THE REGION. HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION NEXT WEEK BRINGING WARMER AND MORE HUMID CONDITIONS BACK TO THE REGION ALONG WITH INCREASING CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TODAY/... AS OF 1010 PM EDT FRIDAY... NO SIGNIFICANT ADJUSTMENTS LATE THIS EVENING AS SCATTERED SHALLOW CONVECTION SLOWLY WEAKENS ACROSS NW NC AND GRAYSON/CARROLL COUNTY AREAS OF SW VA. THERE HAS BEEN LITTLE IF ANY LTG DETECTED IN THESE SHOWERS LAST SEVERAL HOURS AS THEY SLOWLY DRIFT SOUTHEAST. RAINFALL RATES ARE NOT ALL THAT HIGH ANYMORE...LESS THAN AN INCH PER HOUR...BUT MOVING SLOWLY ENOUGH THAT SOME ISOLATED MINOR FLOODING OF POOR DRAINAGE AREAS IS NOT OUT OF THE QUESTION...BUT THIS LOOKS LIKE IT WILL BE CONFINED TO WILKES AND YADKIN COUNTIES THROUGH MIDNIGHT. OTHERWISE SHOWERS WILL LIKELY DISSIPATE WITHIN A COUPLE HOURS AFTER MIDNIGHT WITH LOSS OF ANY REMAINING INSTABILITY...AND HRRR DEPICTS THIS IDEA BEST...ALTHOUGH SOME OTHER MODELS HANG TO SOME LIGHT SHOWERS THROUGH ENTIRE NIGHT. SLOWLY REDUCE POPS ALL NIGHT DOWN ION FAR SW WITH ONLY A SMALL AREAS OF SLIGHT CHC BY MORNING BUT WOULD NOT BE SURPRISED IF ALL PRECIP IS GONE BY 2 OR 3AM. BIG QUESTION FOR OVERNIGHT IS AMOUNT OF STRATUS THAT WILL SPREAD ACROSS THE AREA...AS WELL AS FOG DEVELOPMENT. WITH DRIER AIR MOVING IN FROM THE NORTH THINK STRATUS WILL NOT BE AS WIDESPREAD AS PREVIOUS NIGHT AND PERHAPS LIMITED TO NEAR BLUE RIDGE AND NRV. BACKED OFF SLIGHTLY ON OVERALL CLOUD COVER...ESPECIALLY FAR WEST...BUT THINK VALLEY FOG WILL EVENTUALLY FORM AS WELL AS ALONG BLUE RIDGE AND MUCH OF PIEDMONT AS WELL. NO CHANGES TO OVERNIGHT LOWS. PREV DISCUSSION AS OF 700 PM EDT FRIDAY... MINOR UPDATE TO ADJUST POPS FOR CURRENT RADAR AND REDUCE SKY COVER OVER SE WV PER LATEST SATELLITE IMAGERY. STILL EXPECTING LOW CLOUDS TO FILL IN MORE ACROSS THE EAST AND INTO ROA AND NRV AFTER SUNSET...BUT MAY STAY RELATIVELY CLOUD FREE A LITTLE LONGER IN FAR WEST. ISOLD SHWRS NORTH OF ROANOKE SHOULD QUICKLY DIE WITH SUNSET...BUT SMALL AREA OF SHOWERS AND ISOLD THUNDER IN NW NC AND AROUND GALAX TO HILLSVILLE MAY PERSIST UNTIL ABOUT MIDNIGHT SINCE IN VICINITY OF WEAK FRONTAL BOUNDARY AND MODELS SUGGEST WEAK INSTABILITY LINGERS THERE INTO LATE EVENING. KEEPING ALL POPS BELOW LIKELY BUT KEPT SOME MID CHANCE A LITTLE LONGER INTO EVENING DOWN IN NC FOOTHILLS. SOME MINOR CONCERNS ABOUT HEAVY RAINFALL AS THESE STORMS ARE DRIFTING SLOWLY SOUTHEAST BUT MAY LINE UP MORE DURING EVENING. STILL...NOT PRODUCING ESPECIALLY HIGH RAINFALL RATES...LESS THAN YESTERDAY...BUT IF THEY LINGER OVER THE SAME AREAS FOR AWHILE...ESPECIALLY THOSE THAT HAD AN INCH OR TWO OF RAIN YESTERDAY...COULD BE SOME MINOR ISSUES WITH WATER IN POOR DRAINAGE AREAS. PREV DISCUSSION AS OF 330 PM EDT FRIDAY... DIFFUSE BACKDOOR COLD FRONT STRETCHES ACROSS SOUTHWESTERN PORTIONS OF THE FORECAST AREA THIS AFTERNOON. CONVECTION DEVELOPING IN THE MOIST UNSTABLE AIR INVOF THE SURFACE BOUNDARY AND TRAVEL SOUTHEAST ALONG THE SOUTHERN EDGE OF WEAK NORTHWEST FLOW ALOFT. SFC BASED CAPES THIS AFTERNOON HAVE CLIMB TO 1000 TO 2000 J/KG WITH LIS AROUND MINUS 4 ACROSS SOUTHWEST CORNER OF CWA THIS AFTERNOON. HOWEVER...WEAK VERTICAL SHEAR WILL LIMIT STORM ORGANIZATION AND LIFE SPAN THIS AFTERNOON INTO THIS EVENING...LOCALLY HEAVY RAINS...GUSTY WINDS AND HAIL ARE POSSIBLE WITH THE STRONGEST THUNDERSTORMS DURING THE NEXT COUPLE OF HOURS. IN SHARP CONTRAST...MARINE AMS IN THE EASTERN PORTION OF THE FORECAST AREA HAS BEEN VERY SLOW TO ERODE AND HOLDING TEMPERATURES DOWN. HARD TO TELL HOW MUCH SUN ANGLE AND MIXING WILL BREAK UP THE LOW CLOUDS THIS EVENING INTO TONIGHT. SATELLITE TRENDS SHOWED THAT WEST EDGE OF CLOUDS BREAKING UP BEFORE SUNSET. DECIDED TO PLAY POPS TONIGHT CLOSE TO A BLEND OF HRRR AND NAM WITH HIGHEST CHANCES IN SOUTHWEST BASICALLY WEST OF I77. LOW CLOUDS AND FOG WILL REDEVELOP OVERNIGHT. WENT WITH LOW TEMPERATURES TONIGHT CLOSE TO THE ADJMETBC WITH READINGS FROM THE MID 50S IN THE COOLER MOUNTAIN VALLEYS TO THE LOWER 60S IN THE SOUTHEAST. WITH BOUNDARY ACROSS NORTH CAROLINA AND SOUTHEAST UPSLOPE FLOW...KEPT ISOLATED SCATTERED POPS FOR CONVECTION ACROSS SOUTHWEST CORNER OF CWA. THE SWODY2 HAS PUSHED MENTION OF THUNDERSTORMS SOUTH OF OUR FORECAST AREA FOR SATURDAY. MORNING LOW CLOUDS AND FOG SHOULD MIX OUT OR LIFT BY LATE SATURDAY MORNING. HIGH TEMPERATURES SATURDAY ARE A CHALLENGE WITH EASTERLY FLOW AND CLOUD COVER. RAISED HIGHS UP SATURDAY AFTERNOON WITH READINGS FROM THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... AS OF 330 PM EDT FRIDAY... DIFFUSE FRONT WASHES OUT OVER THE SOUTHERN APPALACHIANS AS SURFACE HIGH PRESSURE SINKS SOUTH ACROSS THE DELMARVA SUNDAY. THE SURFACE HIGH THEN BECOMES POSITIONED JUST OFF THE CAROLINA COAST MONDAY. EXPECTING A DRY FINISH TO THE WEEKEND ALONG WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES...FOLLOWED BY A TRANSITION TO WARMER TEMPERATURES AND A THREAT OF AFTERNOON SHOWERS BEGINNING MONDAY. FOR SATURDAY NIGHT AND SUNDAY OR UNTIL THE HIGH BECOMES SITUATED OFF THE SOUTHEAST ATLANTIC COAST...SURFACE WINDS WILL REMAIN FROM THE EAST. THIS WILL PROMOTE SHALLOW UPSLOPE CLOUDINESS ALONG AND EAST OF THE APPALACHIAN DIVIDE...BKN SORT OF CONDITIONS SATURDAY NIGHT AND SCATTERED SUNDAY. BY MONDAY TENDENCY WILL BE FOR MODERATE CU FORMATION OVER THE MOUNTAINS AS RETURN SOUTHWESTERLY FLOW BRINGS INCREASING DEWPOINTS AND HIGHER CAPE. H85 TEMPS OF 8C IN THE VA PIEDMONT ON SUNDAY WILL REBOUND CLOSER TO 15C ON MONDAY. SUNDAY DEFINITELY LOOKS LIKE A WINNER IN TERMS OF COMFORT FOR THE FIRST DAY OF JUNE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 345 PM EDT FRIDAY... THE UPPER FLOW PATTERN NEXT WEEK WILL FEATURE A PERSISTENT UPPER RIDGE CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE SOUTHERN CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS RIDGE...A MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL AND NORTHERN CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT WAVE ENERGY RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT. WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE NORM FOR OVERNIGHT LOWS. THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IT WILL MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN THE FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF THIS UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE TYPICAL DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN THE MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND CONVERGENCE WILL BE THE GREATEST. WITH WESTERLY SORT OF WINDS ALOFT...A LEE TROUGH WILL LIKELY EXIST OVER THE PIEDMONT WHICH WILL AID IN SCATTERED LATE AFTERNOON STORM DEVELOPMENT THERE TOO. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 200 AM EDT SATURDAY... DIFFUSE BACKDOOR FRONT REMAINS ACROSS THE FAR SOUTHWESTERN PART OF THE CWA. THIS WEAK BOUNDARY WILL CONTINUE TO DRIFT SOUTHWEST THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS SW FROM THE MID- ATLANTIC. THIS WILL ALSO FINALLY PUSH DRY AIR FROM THE NE AND NORTHERN MID-ATLANTIC SOUTHWESTWARD INTO THE FORECAST AREA AS THE WEEKEND PROGRESSES. HOWEVER...FOR TODAY...EXTENSIVE LOW CLOUDS WILL CONTINUE TO BANK UP AGAINST THE ALLEGHANYS IN THE EASTERLY MARITIME FLOW. COMPARED TO FRI...THESE CLOUDS WILL TRACK FURTHER WESTWARD AND BEGIN TO ERODE FROM THE EAST THROUGH THE DAY. MVFR CIGS WILL GENERALLY BE MVFR THROUGH THE TAF VALID PERIOD BLF/LWB/BCB/DAN BUT WILL IMPROVE TO LOW END VFR TOWARD AFTERNOON/EVENING AND OVERNIGHT. NOT EXPECTING AS MUCH FOG THIS MORNING AS FRI EITHER...WITH AREAS OF MVFR VIS IN BR THROUGH 14Z...WITH PATCHY IFR BR MAINLY LWB THROUGH 14Z. WINDS NE-SE THROUGH THE TAF VALID PERIOD...WITH SPEEDS INCREASING FROM 5-7KTS TO AROUND 8-10KTS DURING THE AFTERNOON AS HIGH PRESSURE STRENGTHENS ACROSS THE NE U.S. MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... VFR CONDITIONS WILL PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY OVERNIGHT IN MOUNTAIN VALLEYS. THE NEXT CHANCE AT SCATTERED SHOWER AND THUNDERSTORM ACTIVITY RETURNS BY MONDAY AND ESPECIALLY INTO THE MID WEEK PERIOD. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...KK/SK SHORT TERM...PM LONG TERM...PM AVIATION...RAB/SK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
230 AM PDT SAT MAY 31 2014 .SYNOPSIS...A WEAK UPPER LEVEL TROUGH OF LOW PRESSURE WILL LINGER NEAR THE PACIFIC NORTHWEST FOR THE NEXT SEVERAL DAYS...CAUSING ONSHORE FLOW TO PERSIST THROUGH THE PERIOD. WEAK DISTURBANCES WILL OCCASIONALLY BRING A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE CASCADES. THESE DISTURBANCES WILL ALSO DEEPEN THE MARINE LAYER...BRINGING A BETTER CHANCE FOR COASTAL DRIZZLE SUNDAY AND MONDAY. OVERALL THE NEXT FEW DAYS SHOULD BE MOSTLY SUNNY AND PLEASANT INLAND...WITH OCCASIONAL NIGHT AND MORNING LOW CLOUDS. && .SHORT TERM...TODAY THROUGH MONDAY... RADAR AND WATER VAPOR IMAGERY SHOW THAT AN UPPER LEVEL DISTURBANCE HAS SET OFF A THUNDERSTORM NEAR MOUNT ADAMS...WHICH HAS BEEN FAIRLY PERSISTENT THE PAST COUPLE OF HOURS. LIGHTNING DETECTION IMAGERY SHOWS QUITE A FEW LIGHTNING STRIKES OUT OF THIS...MAINLY IN KLICKITAT AND YAKIMA COUNTIES...BUT A COUPLE IN SKAMANIA COUNTY AS WELL. THE UPPER DISTURBANCE RESPONSIBLE FOR THIS WILL CONTINUE OFF TO THE E-SE TODAY...BUT LINGERING INSTABILITY WARRANTS A SLIGHT CHANCE OF THUNDER IN THE CASCADES MOUNT HOOD NORTHWARD THROUGH EARLY THIS EVENING. OVERALL TODAY WILL BE SIMILAR TO YESTERDAY...WITH DECIDEDLY ONSHORE PRESSURE GRADIENTS BUT A WARM AIR MASS ALOFT. WEAK UPPER LEVEL TROUGHING OVER WRN CANADA INTO THE PAC NW IS PROMOTING THIS ONSHORE FLOW. HOWEVER AS WAS THE CASE YESTERDAY...GOOD MIXING ALONG WITH 850 MB TEMPS AROUND +10 DEG C SHOULD SUPPORT TEMPS A FEW DEGREES ABOVE NORMAL INLAND WITH HIGHS GENERALLY IN THE MID TO UPPER 70S. ANY MORNING LOW CLOUDS INLAND SHOULD RETREAT TO THE COAST BY MIDDAY... WITH PLENTY OF SUN FOR THE AFTERNOON. THIS SAME OVERALL PATTERN SHOULD PREVAIL WELL INTO THE UPCOMING WEEK. A WEAK UPPER TROUGH WILL LINGER...KEEPING FLOW ONSHORE AND TEMPERATURES FROM GETTING MUCH ABOVE THE 70S. LOW CLOUDS SHOULD GATHER ALONG THE COAST...KEEPING THEM CLOSER TO 60 DEGREES FOR HIGHS. NIGHT AND MORNING LOW CLOUDS SHOULD GENERALLY RETREAT TO THE COAST BY MIDDAY. ASIDE FROM SOME COASTAL DRIZZLE IT SHOULD REMAIN DRY...THOUGH ANOTHER WEAK DISTURBANCE COULD TRIGGER A COUPLE THUNDERSTORMS ALONG THE CASCADE CREST MONDAY AFTERNOON. WEAGLE .LONG TERM...MONDAY NIGHT THROUGH FRIDAY... LITTLE CHANGE EXPECTED FROM OUR CURRENT PATTERN WELL INTO THE COMING WEEK. IT APPEARS FLOW ALOFT TURNS ANTICYCLONIC BY TUE AFTERNOON... WITH WARMER AIR ALOFT CAPPING ANY INSTABILITY. THUS WE DECIDED TO REMOVE THE MENTION OF THUNDER FROM THE CASCADES TUE. MODELS THEN SHOW FAIRLY GOOD AGREEMENT THAT OUR CURRENT WEAK UPPER TROUGH JUST GETS REPLACED BY ANOTHER BY THURSDAY. THEREFORE EXPECT W-NW FLOW ALOFT TO PERSIST...WITH NO ORGANIZED SYSTEMS TO BRING A THREAT OF MUCH MORE THAN AREAS OF COASTAL DRIZZLE. SFC PRES GRADIENTS WILL REMAIN DECIDEDLY ONSHORE...KEEPING INLAND TEMPS FROM GETTING MUCH MORE THAN A FEW DEGREES ABOVE NORMAL. PERSISTENT COASTAL LOW CLOUDS MAY SPREAD INLAND DURING THE NIGHT AND MORNING HOURS BUT BURN BACK TO THE COAST BY EARLY AFTERNOON...LEAVING PLENTY OF AFTERNOON SUNSHINE FOR AREAS EAST OF THE COAST RANGE. WEAGLE && .AVIATION...VFR NEXT 24 HRS...EXCEPT FOR POCKETS OF MVFR CIGS ALONG THE N AND CENTRAL OREGON COASTLINE. INCREASING MVFR ALONG THE COAST WILL GRADUALLY SPREAD INTO THE COASTAL RIVER DRAINAGES AFTER 12Z THIS MORNING. STILL A QUESTION AS TO HOW FAR THESE CLOUDS WILL PENETRATE INLAND...BUT LOCAL MVFR CIGS REMAIN POSSIBLE AROUND SUNRISE OVER THE SW WA LOWLANDS AND ALONG THE COLUMBIA RIVER TO KPDX AND VICINITY. /27 KPDX AND APPROACHES...VFR NEXT 24 HRS. HOWEVER...THERE IS A 30 TO 40 PERCENT CHANCE MVFR CIGS DEVELOP OVER THE TERMINAL AND VICINITY AROUND 13Z. ANY LOW CLOUDS THAT FORM WILL DISSIPATE BY 17Z. WEISHAAR && .MARINE...HIGH PRESSURE OVER THE NE PAC HOLDING FIRM...AND WILL PERSIST FOR THE NEXT FEW DAYS. GFS MODEL SEEMS TO BE HANDLING THE SURFACE FEATURES WELL. NORTHERLY WIND GUSTS HAVE DROPPED BELOW 25 KT EARLY THIS MORNING...BUT WILL PICK UP AGAIN THIS AFTERNOON. NAM AND GFS INDICATE 20 TO 25 KT WIND SPEEDS 18Z TODAY THROUGH 06Z SUN. MODELS SHOW THE SURFACE RIDGE AXIS A BIT MORE TO THE S SAT AFTERNOON COMPARED TO TODAY. THUS...THE S WA WATERS MAY NOT ACHIEVE SMALL CRAFT ADVISORY SPEEDS. THE LACK OF ANY NOTABLE LONGER PERIOD SWELLS WILL CONTINUE THROUGH THE WEEKEND. EXPECT SEAS TO BE RELATIVELY STEEP AND CHOPPY AS WIND WAVES/FRESH SWELL LOOK TO DOMINATE THROUGH EARLY NEXT WEEK. MODELS INDICATE TIGHTER PRESSURE GRADIENTS ALONG THE WA COAST EARLY NEXT WEEK...RESULTING IN FRESH NW SWELL PUSHING 10 FT BY TUE. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 11 AM THIS MORNING TO 11 PM PDT THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 PM PDT THIS AFTERNOON FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. && $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion National Weather Service Spokane WA 1030 PM PDT FRI MAY 30 2014 .SYNOPSIS... The Inland Northwest will undergo a warming trend this weekend. Many areas will warm into the upper 70s to mid 80s. The majority of the region will remain dry through the middle of next week. However, the mountainous regions of north Idaho and northern Washington will see a chance for showers and thunderstorms each afternoon through mid week. && .DISCUSSION... Evening update: Scattered thunderstorm activity that has been mainly be confined to Kittitas and Yakima counties but is starting to drift northward into southern Chelan County. There have not been any strikes observed in Chelan County but a few cells near the crest could still strengthen over the next hour. With the sun setting, the main threat with this activity will transition to isolated showers. Latest HRRR is doing well with the placement of this activity and takes it to the northeast while falling apart upon reaching southern Okanogan County. Consequently, a few light showers are expected to pass through Wenatchee... Waterville Plateau...and eastern reaches of Chelan County over the next few hours then wane by 06z. The next feature of note is a midlevel circulation that came from northern CA and is driving thunderstorms across Central Oregon. Clouds and any shower activity with this feature will spread into SE WA and the lower ID Panhandle between 6-12z. A few light showers will be possible but once again, the threat for thunder is low (not entirely impossible) but too low to differ from the dayshifts thoughts which advertised showers over thunderstorms. I did spread the threat for sprinkles and light showers northward into Pullman/Lewiston and increased cloud cover. This also lead to raising overnight temperatures for most locations south of line from Mullan to La Crosse. /sb && .AVIATION... 06Z TAFS: VFR conditions expected at all terminals through 06z Sat. The sct t-storm activity that was over the Cascades has waned to showers. Steering flow will drift the convective debris and a some sprinkles over KEAT at times. A second cluster of elevated showers tracking NE through Oregon is currently near KPDT. This activity is also expected to weaken and only bring the threat for increased clouds and a few light showers in the vcnty of KLWS/KPUW. Aft 20z...aftn heating and presence of upper-low over the region will renew the threat for -shra and isold -tsra mainly across the mtns but with the best instability focusing in the ID Panhandle and Blue Mtns...may see a few -shra vcnty KLWS/KPUW. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 50 78 51 79 53 81 / 10 10 10 0 0 10 Coeur d`Alene 48 78 48 78 50 80 / 0 10 10 10 10 10 Pullman 49 77 46 77 48 81 / 10 10 10 0 0 0 Lewiston 55 84 53 84 55 88 / 10 10 10 10 0 0 Colville 45 78 48 80 50 84 / 10 20 10 10 10 10 Sandpoint 45 77 45 78 47 80 / 0 20 20 10 10 10 Kellogg 47 75 48 75 50 80 / 10 30 20 10 10 10 Moses Lake 49 84 52 86 54 88 / 0 0 0 0 0 0 Wenatchee 53 84 59 86 61 88 / 20 10 0 0 0 0 Omak 43 82 51 85 53 87 / 10 10 0 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
843 AM MDT SAT MAY 31 2014 .UPDATE... ISSUED AT 843 AM MDT SAT MAY 31 2014 DISTURBANCE EJECTING ACROSS THE WRN SLOPE THIS MORNING AHEAD OF THE MAIN TROUGH AXIS. SCATTERED SHOWERS AND THUNDERSTORMS PERSIST ACROSS NW COLORADO...POORLY RESOLVED BY MOST HIGHER RESOLUTION MODELS. APPEARS THE TREND FOR TODAY WILL BE DRIER AIR FOLLOWING THIS DISTURBANCE...EVIDENT ON THE WATER VAPOR ACROSS THE SRN PORTION. THE BEST CONVECTIVE POTENTIAL MAY BE OCCURRING THIS MORNING HOURS...BUT DECREASES THIS AFTERNOON EXCEPT ALONG THE COLORADO SPINE. THE MODELS HINT AT ANOTHER EVENING DISTURBANCE CROSSING NE UTAH INTO NW COLORADO THAT COULD SPAWN ANOTHER ROUND OF SCATTERED SHOWERS AND STORMS. WILL ASSESS THIS POTENTIAL IF THE INCOMING MODELS CONTINUE TO SUPPORT THIS. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 308 AM MDT SAT MAY 31 2014 OVERNIGHT CONVECTION CONTINUES AS SMALL PIECES OF ENERGY MOVE THROUGH THE MEAN FLOW ALLOWING SOME QUICK SHOWERS AND WEAK STORMS TO FIRE BEFORE QUICKLY SCOOTING OFF TO THE EAST. THE HRRR IS DOING FAIRLY WELL PICKING UP ON THIS CONVECTION SO FOLLOWED THIS GUIDANCE WITH MOST CONVECTION DYING DOWN NEAR SUNRISE THOUGH AN ODD CELL OR TWO MAY REMAIN...BEFORE PICKING UP AGAIN FROM NOON ONWARDS. PWATS REMAIN HIGH WITH INSTABILITY AND CAPE FAVORING HIGHER ELEVATIONS WITH FORECAST FOLLOWING SUIT. ATTM...MODELS FAVORING THE FLATTOPS AND CENTRAL MTNS BUT EXPECT COVERAGE TO BE A BIT MORE THAN THAT. THOSE AREAS THAT SEE THESE STORMS WILL EXPERIENCE GUSTY OUTFLOW WINDS AND BRIEF HEAVY RAIN. TONIGHT AND SUNDAY...THE WESTERN TROUGH WILL BE SEPARATING FROM THE LEFT COAST THIS EVENING AS THE MAIN UPPER LOW PUSHES INTO THE NORTHERN ROCKIES...PULLING THE BASE OF THE TROUGH INTO THE GREAT BASIN. LARGE SCALE ASCENT AHEAD OF THE TROUGH WILL FOCUS MAINLY TO OUR NORTH. HOWEVER ADDED LIFT WILL COME FROM THE INDIRECT CIRCULATION OF THE SUBTROPICAL JET NOSING INTO UTAH THIS EVENING. ANOTHER ROUND OF NOCTURNAL CONVECTION LOOKS TO PUSH ACROSS OUR CWA WITH THE BETTER FOCUS ACROSS THE NORTH. CLOUDY CONDITIONS WILL KEEP THINGS MILD AGAIN OVERNIGHT AND AS MORE SUNSHINE IS EXPECTED ON SUNDAY...TEMPERATURES WILL RETURN TO WELL ABOVE NORMAL IN THE AFTERNOON. DRIER AIR FILTERS IN AND EXPECT CONVECTION TO BE WANING BY SUNRISE WITH ONLY HIGH BASED WEAK SHOWERS LINGERING IN THE NORTHEAST ON SUNDAY. SNOW MELT WILL CONTINUE ACROSS THE HIGH COUNTRY AND KEEP RIVERS RUNNING STRONG. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 308 AM MDT SAT MAY 31 2014 SUNDAY NIGHT INTO MONDAY...QUIET CONDITIONS ARE EXPECTED DURING THIS TIME PERIOD AS A SUBTROPICAL HIGH CENTERED OVER THE BAJA BULGES NORTHWARD INTO THE 4 CORNERS AREA. THIS EFFECTIVELY CUTS OFF A MOISTURE TAP AND TEMPERATURES WILL RESPOND BY WARMING A FEW DEGREES ON MONDAY AFTERNOON. MODELS IN FAIR AGREEMENT PUSHING THE NEXT PACIFIC LOW INTO CALIFORNIA MONDAY AFTERNOON. THIS WILL BEGIN TO TIGHTEN THE GRADIENT ALOFT AND BRING MORE AFTERNOON BREEZINESS ALONG WITH THE WARMER TEMPERATURES. THE SUBTROPICAL AREA OF HIGH PRESSURE WILL REMAIN SOUTH OF THE FORECAST AREA MONDAY AS A WAVE APPROACHES FROM THE WEST. FORECAST MOISTURE REMAINS LOW WITH LITTLE PRECIP EXPECTED. AS THE WAVE MOVES THROUGH TUESDAY...WINDS ARE EXPECTED TO PICK UP INCREASING FIRE WX CONCERNS AS DRY CONDITIONS WILL BE IN PLACE. AFTER THAT...THE HIGH TO THE SOUTH GETS FLATTENED...AN AREA OF LOW PRESSURE SKIRTS THE US/CANADIAN BORDER LEAVING ERN UT/WRN CO TO DEAL WITH CONTINUED WARM TEMPS AND DRY CONDITIONS. A WEAK WAVE WILL MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY BUT WITH LITTLE UPPER AIR SUPPORT AND MEAGER MOISTURE...AN OCCNL SHOWER/STORM MAY POP UP HERE OR THERE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 308 AM MDT SAT MAY 31 2014 VFR WILL CONTINUE THROUGH 18Z BEFORE ANOTHER ROUND OF SHOWERS AND STORMS FORM OVER THE HIGHER TERRAIN WITH SOME STORMS DRIFTING OVER NEARBY VALLEYS. MTN TAF SITES LOOK TO BE UNDER THE GUN TODAY INCLUDING KEGE...KASE...AND KTEX THOUGH CONFIDENCE IS LOW THAT SHOWERS OR STORMS WILL FORM ON-STATION. GUSTY WINDS AND SOME BRIEF HEAVY RAIN WILL BE MAIN CONCERNS TODAY WITH STORMS THAT FORM. SOME CONVECTION WILL CONTINUE OVERNIGHT. && .HYDROLOGY... ISSUED AT 308 AM MDT SAT MAY 31 2014 WARM TEMPERATURES CONTINUE TO MELT THE SNOWPACK ACROSS THE REGION WITH RIVERS AND STREAMS FORECAST TO REMAIN HIGH OR INCREASE THROUGH EARLY NEXT WEEK. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TODAY MAY CAUSE ADDITIONAL FLOW INCREASES. THE HIGHEST FLOWS ARE OCCURRING IN RIVERS AND STREAMS FROM THE GUNNISON BASIN IN WEST-CENTRAL COLORADO NORTHWARD TO THE WYOMING BORDER AND ACROSS NORTHEAST UTAH. THAT BEING SAID...ALL RIVERS AND STREAMS ACROSS THE FORECAST WILL BE RUNNING FAST AND STRONG THIS WEEKEND INTO NEXT WEEK. VARIOUS FLOOD PRODUCTS REMAIN IN EFFECT FOR THESE CONDITIONS. PAY ATTENTION TO RIVER...CREEK AND STREAM LEVELS AND WATCH FOR DEBRIS BUILDUP. PLEASE USE CAUTION IF YOU PLAN ON BOATING DOWN OR RECREATING NEAR ANY RIVERS OR STREAMS THROUGH EARLY NEXT WEEK. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...PF SHORT TERM...TGR/15 LONG TERM...15/TGR AVIATION...TGR HYDROLOGY...TGR
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1036 AM EDT Sat May 31 2014 .Near Term [Through Today]... Showers and thunderstorms this morning over the Gulf of Mexico have mostly dissipated, except for a few lingering showers just west of Panama City as of 14Z. Therefore, most of the forecast area was experiencing dry conditions with a mixture of low-mid level cloud decks and sunshine. Overall, there is very little difference between the 12Z sounding taken this morning from Tallahassee, and the one taken 24 hours ago. Light E-SE flow continues in the lower troposphere, with fairly light flow aloft. Recent runs of the 3km HRRR as well as the 09Z run of our 4km WRF- ARW appear to be modeling ongoing conditions fairly well. Both show the most concentrated initial convective development between 17Z and 19Z in the Apalachicola River basin as well as the eastern Florida Big Bend near the Suwannee River. They also both show activity in the Florida Panhandle and Big Bend diminishing around 22Z, with the 22-04Z time frame being dominated by larger convective clusters in southwest Georgia. This would make sense with lighter E-SE 1000-700mb flow as thunderstorms along the Atlantic sea breeze and inland Florida peninsula trough should progress into eastern parts of the area closer to sunset, and possibly combine with previous inland development in C/SC GA. Given that these models have verified well so far, and the similarities in evolution to what occurred yesterday, we have tweaked the forecast to follow that general timeline. The inherited forecast, however, already described that fairly well. Highs should be around 90 degrees - warmest in SW Georgia. && .Prev Discussion [257 AM EDT]... .Short Term [Tonight Through Monday]... The upper low west of the region will gradually but steadily fill as it drops south into the western Gulf of Mexico tonight and Sunday. Mesoscale processes, including the sea breeze, will provide the primary forcing for convection and PoP distribution, typical of summertime. The east coast sea breeze will once again concentrate evening convection primarily across our Southwest GA zones. Look for fairly evenly scattered convection on Sunday with PoPs around 50 as PWs remain elevated around 2 inches. As surface high pressure builds further down the eastern seaboard on Monday, our 1000-700 mb winds will become light out of the east across our eastern zones while southeasterly winds persist further west. In addition, drier air will build in from the east pushing PWs below 1.5 inches in that region. This should reduce convective coverage, particularly across our eastern zones. Temperatures will be close to seasonal norms. .Long Term [Monday Night Through Saturday]... The upper level low will slide off the west as the upper level ridge moves east toward the Carolinas. Winds from the southeast will bring moisture from the Gulf increasing the chance for showers. Better chance for afternoon and evening sea breeze thunderstorms Monday and Tuesday. Temperatures will be near climatology with highs in the upper 80s and low 90s and lows in the upper 60s. .Aviation... [Through 06Z Sunday] Low ceilings and MVFR fog should overspread at least VLD, and possibly TLH and ABY over the next few hours. All terminals will return to VFR shortly after sunrise. Expect showers and thunderstorms at ECP and VLD, earlier in the day at ECP and towards mid to late afternoon at VLD. This evening, showers and thunderstorms should reach TLH and possibly ABY. Expect VFR to prevail today outside of thunderstorms. .Marine... Winds will generally be out of the east-southeast over the next several days, veering to more directly onshore near the coast each afternoon in the sea breeze. A ridge of high pressure will build down the eastern seaboard and the gradient will become tight enough for an easterly surge event Sunday night, which is now expected to bring cautionary level winds and seas to the waters. As the ridge settles further south, the gradient will weaken allowing winds and seas to subside for the early part of the work week. .Fire Weather... Hazardous fire weather conditions are not expected over the next several days. .Hydrology... With a summertime pattern well established across the region, large scale flooding is not anticipated. As on most summer days, isolated areas of heavy rain will be possible in some thunderstorms. These may briefly produce flooding in poor drainage areas and could cause sharp rises on the faster responding small creeks and streams. Main stem rivers are expected to remain in their banks. && .Preliminary Point Temps/PoPs... Tallahassee 89 69 88 68 88 / 40 40 50 40 30 Panama City 84 72 86 72 86 / 60 20 50 40 40 Dothan 89 69 89 68 88 / 40 40 50 40 30 Albany 90 69 87 66 88 / 70 60 50 30 20 Valdosta 91 68 90 65 90 / 70 50 50 20 20 Cross City 88 68 88 67 88 / 60 40 50 30 30 Apalachicola 84 72 86 73 85 / 30 20 40 40 30 && .TAE Watches/Warnings/Advisories... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...LAMERS SHORT TERM...WOOL LONG TERM...WESTON AVIATION...HARRIGAN MARINE...WOOL FIRE WEATHER...HARRIGAN HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1030 AM EDT SAT MAY 31 2014 .UPDATE (REST OF TODAY AND TONIGHT)... 14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A COMPLEX UPPER LEVEL PATTERN OVER THE CONUS CONSISTING OF AN AMPLIFIED NORTHERN STREAM FLOW OVER TOP A STUBBORN CUT OFF LOW SPINNING OVER THE SOUTHERN MS VALLEY. NORTHERN STREAM FLOW RIDGES WAY TO THE NORTH INTO CENTRAL/EASTERN CANADA BEFORE SHARPLY DIVING SOUTH INTO A DEVELOPING CLOSED LOW OFF THE NEW ENGLAND COAST. THE UPPER LOW OVER THE NORTHERN GULF COAST IS SHOWING SIGNS OF A SLOW SOUTHWARD MOVEMENT. PLENTY OF CONVECTION ONCE AGAIN OVER THE CENTRAL GULF TODAY ASSOCIATED WITH THE CYCLONIC CIRCULATION...HOWEVER THIS MORE ORGANIZED CONVECTION WILL REMAIN WELL OFF THE FLORIDA WEST COAST WITH LITTLE IMPACT ON OUR WEATHER OTHER THAN SOME "BLOW-OFF" CIRRUS INVADING OUR SKIES. THE MORNING 12Z KTBW SOUNDING SHOWS WE HAVE A MOIST PROFILE THROUGH THE EXTENT OF THE TROP WITH A MEASURED PW VALUES AROUND 1.75". STEERING LEVEL FLOW THROUGH 400MB IS VERY VERY LIGHT (VECTOR AVERAGE IS JUST A SLIGHT PUSH FROM EAST TO WEST)...AND GUIDANCE KEEPS THIS FLOW ABOVE THE SURFACE LIGHT THROUGH THE EVENING HOURS. STORM MOTION VECTORS ARE MAYBE 5-10KNOTS FROM EAST TO WEST...SO WILL BE LOOKING FOR SOME SLOW MOVING CELLS LATER TODAY. OVERALL CAPE WITH THE MOIST SOUNDING WILL NOT BE ALL THAT HIGH (AT LEAST NOT TOO FAT A PROFILE THROUGH ANY ONE LEVEL)...HOWEVER THE HIGH PW VALUE WILL FAVOR EFFICIENT WATER LOADING OF THE STRONG CELLS WHICH WILL KEEP THE THREAT FOR LOCALLY DAMAGING WIND GUSTS IN THE FORECAST FOR YET ANOTHER DAY. AT THE SURFACE...THE REGION IS EXPERIENCING A WEAK EASTERLY TO SOUTHEASTERLY FLOW PATTERN BETWEEN A STRONG RIDGE OF HIGH PRESSURE BEGINNING TO BUILD DOWN THROUGH THE OHIO VALLEY/MID-ATLANTIC STATES...AND A WEAK SURFACE TROUGH IN PLACE OVER THE WESTERN GULF OF MEXICO. AS THIS RIDGE TO OUR NORTH BUILDS DOWN THE EASTERN SEABOARD THROUGH THE WEEKEND...THE LOCAL GRADIENT WILL BEGIN TO TIGHTEN AND RESULT IN SOME BREEZIER CONDITIONS BY SUNDAY AFTERNOON AND INTO THE EARLY PORTION OF NEXT WEEK. THIS STRONGER EASTERLY FLOW WILL CHANGE THE STRUCTURE AND PATTERN OF AFTERNOON STORMS THAT WE HAVE BECOME ACCUSTOMED TO OVER THE PAST SEVERAL DAYS. BUT..THAT IS TOMORROW...LETS TALK MORE ABOUT TODAY. THE LIGHT EASTERLY FLOW WILL FAVOR A QUICK INLAND PENETRATION OF THE EAST COAST SEA-BREEZE. EXPECT TO SEE A SCATTERING OF SHOWERS/STORMS DEVELOPING OVER SOUTH FLORIDA AND UP THE SPINE OF THE PENINSULA BY EARLY AFTERNOON...WHICH WILL THEN SLOWLY EVOLVE/TRANSLATE TO THE WEST AND NORTHWEST THROUGH THE LATER AFTERNOON/EARLY EVENING HOURS. THE COLUMN SEEMS PRIMED FOR STORM COVERAGE TO AGAIN BE NUMEROUS IN NATURE ALONG THE I-75 CORRIDOR...AND THINK STORMS WILL HAVE AN EASIER TIME MOVING WEST TO THE COAST TODAY (ALTHOUGH IT WILL BE SLOW). AS MENTIONED ABOVE...WATER LOADING OF THE STRONG CELLS WILL STILL PROVIDE A LOCALIZED WIND THREAT...ESPECIALLY ALONG AND INSIDE THE I-75 CORRIDOR (AFTER 3-4PM) WHERE LOW LEVEL CONVERGENCE/FOCUS FOR THE BEST UPDRAFTS WILL BE MAXIMIZED ALONG THE SEA-BREEZE...AND RESIDUAL OUTFLOW BOUNDARIES. LOCALLY RUN WRFARW GUIDANCE RUNS HAVE BEEN FAIRLY AGGRESSIVE WITH THE CONVECTIVE COVERAGE OVER THE PAST FEW RUNS...AND FEEL CONFIDENT WITH THE CURRENT 60-70% POPS IN THE GRIDS ALONG THE FAVORED ZONE MENTIONED ABOVE. LEFTOVER STORMS WILL DIMINISH AND MOVE OFFSHORE WITH THE LOSS OF DIURNAL HEATING LATER THIS EVENING...ALLOWING THE TYPICAL WARM SEASON CALM PERIOD FOR MUCH OF THE OVERNIGHT. SEASONAL TEMPERATURES ARE EXPECTED WITH MANY SPOTS SEEING UPPER 60S TO LOWER 70S BY SUNRISE. && .MID TERM (SUNDAY-MONDAY) HIGH PRESSURE OVER NEW ENGLAND AND THE MID ATLANTIC STATES WILL SHIFT STEADILY SOUTHWARD TO A LOCATION OFF THE CAROLINA COASTLINE BY MONDAY EVENING. THIS WILL PROPEL A SURFACE FRONTAL BOUNDARY SOUTHWARD INTO NORTH FLORIDA ON SUNDAY WITH THE BOUNDARY CONTINUING TO SLIDE SOUTHWARD INTO SOUTH FLORIDA BY MONDAY EVENING. DEEP MOISTURE WILL REMAIN PLENTIFUL ON SUNDAY...SO WILL CARRY HIGH CHANCE/LIKELY POPS IN ALL AREAS FOR MAINLY AFTERNOON/EARLY EVENING SHOWERS AND THUNDERSTORMS. AS THE FRONTAL BOUNDARY SLIPS FURTHER SOUTHWARD ON MONDAY...COLUMN MOISTURE WILL BEGIN TO DECREASE ACROSS NORTHERN AREAS. AS A RESULT...WILL SHOW POPS RANGING FROM 20 PERCENT ACROSS THE NATURE COAST TO 50/60 PERCENT ACROSS SOUTHWEST FLORIDA MONDAY AFTERNOON. HIGH TEMPERATURES ARE EXPECTED TO TOP OUT IN THE UPPER 80S TO AROUND 90 DEGREES EACH AFTERNOON. LOWS SUNDAY NIGHT ARE EXPECTED TO BOTTOM OUT IN THE UPPER 60S TO LOWER 70S. && .LONG TERM (MONDAY NIGHT-SATURDAY)... MEDIUM RANGE GUIDANCE IS OFFERING UP VARYING SOLUTIONS THROUGH THE LONG TERM PERIODS...LEADING TO LOWER THAN NORMAL FORECAST CONFIDENCE. THE 00Z ECMWF AND 00Z CANADIAN BOTH SHOW STRONGER DEEP LAYER RIDGING BUILDING INTO THE AREA THROUGH THE MIDDLE TO LATTER PORTION OF THE UPCOMING WORK WEEK...AND AS A RESULT THEY KEEP THE DEEPEST MOISTURE SOUTH OF THE PENINSULA AND OUT OVER THE GULF OF MEXICO. THE 00Z GFS ON THE OTHER HAND SHOWS WEAKER DEEP LAYER RIDGING BUILDING INTO THE AREA...ALLOWING THE FRONTAL BOUNDARY AND DEEPER COLUMN MOISTURE TO HANG UP OVER SOUTH FLORIDA THROUGH THE WEEK. GIVEN THE LACK OF STRONG CONSENSUS AMONGST THE OPERATIONAL MODELS...WILL KEEP RAIN CHANCES IN THE FORECAST FOR MAINLY AFTERNOON/EARLY EVENING SHOWERS AND THUNDERSTORMS...WITH HIGHEST POPS ACROSS SOUTHERN ZONES. && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THE DAY AWAY FROM SCT-NMRS SHOWERS/STORMS WHICH ARE EXPECTED TO DEVELOP DURING THE MID/LATE AFTERNOON AND THEN PROGRESS SLOWLY WESTWARD TOWARD THE COAST INTO THE EVENING HOURS. PROBABILITIES ARE HIGH FOR MANY OF THE TERMINALS TO SEE A BRIEF RESTRICTION ASSOCIATED WITH A PASSING STORM...BUT THE DURATION SHOULD BE SHORT. STORMS WILL DIMINISH AND MOVE OFFSHORE AFTER MID EVENING WITH VFR GENERAL VFR AND DRY CONDITIONS RETURNING TO ALL THE TERMINALS. && .MARINE... EASTERLY WINDS WILL PREVAIL ACROSS THE WATERS THROUGH MID WEEK AS HIGH PRESSURE OVER THE NEW ENGLAND STATES SHIFTS SOUTHEASTWARD TOWARD THE CAROLINA COAST THE NEXT COUPLE OF DAYS. WINDS ACROSS NEARSHORE WATERS WILL BECOME WESTERLY EACH AFTERNOON AND EVENING WITH SEA BREEZE DEVELOPMENT...AND ANY SHOWERS AND STORMS THAT DEVELOP ALONG SEA BREEZE BOUNDARIES OVER INLAND AREAS WILL PUSH OFFSHORE EACH DAY...BRINGING DANGEROUS LIGHTNING AND BRIEFLY ELEVATED WINDS AND WAVES TO THE WATERS. WINDS AND WAVES MAY REACH HEADLINE CRITERIA OVERNIGHT SUNDAY NIGHT DUE TO A THE EFFECTS OF A TIGHTENING PRESSURE GRADIENT AND EASTERLY SURGE. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES WILL REMAIN ABOVE CRITICAL LEVELS THROUGH THE NEXT SEVERAL DAYS AND NO RED FLAG CONDITIONS ARE EXPECTED. INCREASE TRANSPORT WINDS FROM THE EAST ON SUNDAY WILL RESULT IN LOCALLY HIGH DISPERSION INDICES...ESPECIALLY NEAR THE COAST AS SURFACE WINDS WEAKEN IN THE AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... TPA 88 74 90 73 / 60 30 70 20 FMY 91 72 91 73 / 60 20 60 20 GIF 90 72 89 71 / 60 20 50 10 SRQ 89 73 91 73 / 60 30 70 30 BKV 89 69 90 70 / 60 30 60 10 SPG 87 75 89 75 / 60 30 70 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/AVIATION/FIRE WX...MROCZKA MID TERM/LONG TERM...21/JELSEMA MARINE...LEWIS
AREA FORECAST DISCUSSION
NWS POCATELLO ID
921 AM MDT SAT MAY 31 2014 .UPDATE...CONVECTION FROM EARLY THIS MORNING HAS MOVED NORTHEAST OF THE REGION THIS MORNING. SHORTWAVE OVER OREGON THIS MORNING WILL BE THE NEXT MAIN PLAYER FOR AFTERNOON/EVENING CONVECTION. 12Z NAM AND LATEST RAP/RUC THIS MORNING SHOWING VARYING AMOUNTS OF INSTABILITY ACROSS THE REGION. HRRR IN FAVOR OF HOLDING OFF ADDITIONAL DEVELOPMENT UNTIL MID TO LATE AFTERNOON...AND NOT QUITE WHERE THE OTHER MODELS ARE PLACING THE BEST INSTABILITY. CLOUD DECK MOVING ACROSS THE REGION AHEAD OF OREGON SHORTWAVE COULD BE THE LIMITING FACTOR IN FURTHER DESTABILIZATION OF THE AIR MASS TODAY...WITH CURRENT BEST INSTABILITY IN THE CLEARING OVER THE EXTREME SOUTHEAST CORNER. BEST GUESS RIGHT NOW IS A BLEND OF THE SIGNALS...AND CURRENT GRIDS PLAY THIS OUT FAIRLY WELL. PRECIPITABLE WATER IS LOW WITH DRY SOUNDINGS SO SMALL HAIL/GUSTY WINDS BEST THREAT FOR TODAY. NO UPDATES ANTICIPATED THIS MORNING. DMH && .PREV DISCUSSION... /ISSUED 325 AM MDT SAT MAY 31 2014/ SHORT TERM...TODAY THROUGH SUNDAY EVENING. STORM NUMBER 1 WILL WORK ITS WAY ACROSS THE REGION AND OFF TO OUR EAST BY TOMORROW. WE ARE ALREADY SEE SOME MOISTURE WORK IN FROM THE SOUTH AND WEST EARLY THIS MORNING. FOR NOW THOUGH...IT APPEARS THIS IS ALL MID- LEVEL MOISTURE AND VIRGA. YOU CAN EXPECT PERHAPS A FEW SPRINKLES AND GUSTY WINDS OUT OF ANYTHING BEFORE NOON. AS THE SYSTEM ENTERS FAR WESTERN IDAHO THIS AFTERNOON...AN BIG UPTICK IN SHOWERS AND STORMS IS FORECAST ESPECIALLY ACROSS THE CENTRAL MOUNTAINS AND UPPER SNAKE HIGHLANDS. THIS IS WHEN WE WILL SEE A LITTLE BETTER POTENTIAL FOR SOME RAINFALL...ALTHOUGH IT WILL BE LIGHT FOR THE MOST PART. SOME LOCALLY HEAVY DOWNPOURS ARE POSSIBLE...AGAIN ESPECIALLY FARTHER NORTH. THERE ARE SOME INDICATIONS THAT GUSTY DOWNBURST WINDS OVER 40MPH AND SMALL HAIL MAY OCCUR WITH STRONGER STORMS. RIGHT NOW...WE ARE LOOKING AT ANY BIG THREAT OF SEVERE STORMS...BUT WE WOULD NOT BE SURPRISED TO SEE A COUPLE OF STORMS BECOME BRIEFLY SEVERE DUE TO STRONG DOWNBURST WINDS. FOR TONIGHT...LINGERING SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED ACROSS A GOOD CHUNK OF THE CENTRAL AND EASTERN HIGHLANDS AS WELL AS THE UPPER PLAIN. BY TOMORROW AFTERNOON...AS THE STORM SHIFTS TOWARD THE NORTHERN PLAINS ANY REAL STORM THREAT WILL BE NORTH OF A HAILEY TO ALPINE, WYOMING LINE. SOME STORMS WILL BE STRONG...BUT NOTHING IS EXPECTED TO BE SEVERE. WE WILL SEE A SLIGHT COOLDOWN THROUGH TOMORROW...BUT STILL LOOKING AT 70S FOR THE LOWER VALLEYS. FOR THOSE HEADING INTO THE HIGH COUNTRY...50S AND 60S ARE ON TAP DURING THE DAY. AT NIGHT...SOME HIGHER PEAKS AND MOUNTAIN VALLEYS WILL DIP TO NEAR 35 DEGREES SO MAKE SURE YOU ARE PREPARED. KEYES LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. AS THE NEXT SYSTEM MOVES ASHORE ON MONDAY...HIGH PRESSURE BRIEFLY POPS UP OVER IDAHO. THIS WILL PUSH SOME FOLKS BACK UP INTO THE LOW 80S. THERE WILL BE ENOUGH MOISTURE THOUGH FOR ISOLATED SHOWERS AND STORMS MAINLY ACROSS THE CENTRAL MOUNTAINS AND UPPER SNAKE HIGHLANDS. WE ARE LOOKING AT 1-2 PUNCH FOR TUESDAY AND WEDNESDAY AS THE FIRST WAVE MOVES ACROSS QUICKLY FOLLOWED BY WAVE NUMBER 2. THIS IS WHERE THE FORECAST GETS MORE COMPLICATED FOR THE REST OF NEXT WEEK. THIS STORM ACTUALLY SPLITS AND WE ARE UNDER THE EFFECTS OF THE NORTHERN BRANCH OF THE SPLIT. THE ECMWF IS QUITE A BIT WETTER WITH THIS PATTERN VS THE GFS. AS IT STANDS RIGHT NOW...THE NORTHERN AND EASTERN MOUNTAINS WOULD SEE THE BEST CHANCE FOR PRECIPITATION REGARDLESS OF HOW MUCH AND THE FORECAST WILL REFLECT THIS FOR BOTH DAYS. AFTER THAT...ALL OF THE EXTENDED MODELS SHOW A LARGER SYSTEM SETTLING SOUTHWARD ACROSS SOUTHERN CANADA AND NORTHERN U.S. IT LOOKS EASTERN IDAHO WILL BE ON THE FAR SOUTHERN END...WHICH WOULD PUT HIGHER CHANCES ACROSS THE NORTH. TEMPERATURES THROUGH THE EXTENDED WILL STILL BE RUNNING 5-10 DEGREES ABOVE AVERAGE WITH SOME FLUCTUATION LIKELY DUE TO CLOUD COVER. LOWS WON`T BE TOO BAD EXCEPT FOR SOME HIGHER PEAKS AND MOUNTAIN VALLEYS WHERE WE WILL SEE TEMPERATURES TRYING TO DROP CLOSE TO FREEZING SOME MORNINGS. KEYES AVIATION...SOUTHWESTERLY FLOW AHEAD OF LOW PRESSURE TROUGH OVER WASHINGTON WILL INCREASE INSTABILITY LATE THIS MORNING IN THE CENTRAL MOUNTAINS INCLUDING KSUN AND AREAS NEAR THE MONTANA AND IDAHO BORDER. ISOLATED THUNDERSTORMS POSSIBLE AT KIDA...KPIH AND KBYI AFTER 20Z. THE TROUGH TO THE WEST WILL ADVANCE OVER SOUTHEAST IDAHO TONIGHT. SOME RESPECTABLE COLD AIR ALOFT...LAPSE RATES REMAIN STEEP PAST MIDNIGHT TONIGHT AND ISOLATED THUNDERSTORMS REMAIN A CONCERN PARTICULARLY AT KSUN AND KIDA. RS FIRE WEATHER...A LOW PRESSURE TROUGH OVER WASHINGTON AND OREGON THIS MORNING WILL CROSS SOUTHEAST IDAHO OVER NIGHT TONIGHT. INSTABILITY WILL INCREASE IN SOUTHWESTERLY FLOW AHEAD OF THIS DISTURBANCE. SOME WIDELY SCATTERED THUNDERSTORMS MAY DEVELOP AROUND SUN VALLEY TO STANLEY AND TOWARDS MONIDA PASS BY LATE THIS MORNING. BEST LIGHTNING POTENTIAL AND SCATTERED THUNDERSTORMS SHOULD BE IN THE TARGHEE FOREST AREA ALONG THE MONTANA BORDER THIS AFTERNOON AND EARLY EVENING. THE AIRMASS REMAINS UNSTABLE PAST MIDNIGHT WITH THE DISTURBANCE MOVING EAST TO NORTHEAST OVERHEAD THROUGH SUNDAY MORNING. PRECIPITATION FROM SHOWERS AND THUNDERSTORMS WILL BE MOSTLY IN THE .01 TO .07 RANGE...VERY ISOLATED CELLS PRODUCING CLOSE TO .10 INCH. BY SUNDAY AFTERNOON FLOW PATTERN BECOMES WESTERLY WITH LINGERING SHOWERS IN THE CENTRAL MOUNTAINS AND TARGHEE AREA. TEMPERATURES WILL BE A COUPLE DEGREES COOLER TODAY...THEN 5 TO 7 DEGREES COOLER SUNDAY. RS HYDROLOGY...CONDITIONS ON VALLEY CREEK AROUND STANLEY ARE STEADILY IMPROVING THIS MORNING. THE MAIN CONCERN FOR RIVERS AND TRIBUTARIES WILL BE THE TETON RIVER BASIN. THE TETON RIVER AT ST. ANTHONY IS STILL FORECAST TO BE BANKFULL AFTER TODAY AND REMAIN THERE. THE TETON RIVER AROUND DRIGGS SHOULD PEAK JUST BELOW BANKFULL...BUT SOME OF THE CREEKS COMING OUT OF THE MOUNTAINS ALONG THE WYOMING BORDER WILL BE RUNNING PRETTY HIGH. KEYES && .PIH WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
842 AM MDT SAT MAY 31 2014 .UPDATE... ISSUED AT 827 AM MDT SAT MAY 31 2014 WATER VAPOR IMAGERY CONTINUES TO SHOW A PLUME OF UPPER LEVEL MOISTURE OVER THE EASTERN 1/3 OF THE AREA. MODELS SHOW DEEP ISENTROPIC LIFT OCCURRING OVER THE SAME AREA CO-LOCATED WITH THE NOSE OF THE LOW LEVEL JET. AS THE DAY PROGRESSES THE NOSE OF THE LOW LEVEL JET MOVES NORTHWARD TAKING THE STRONGER ISENTROPIC LIFT WITH IT. HOWEVER WEAKER ISENTROPIC LIFT WILL CONTINUE OVER THE EASTERN 1/3 AHEAD OF A 700MB SHORT WAVE TROUGH. SOUNDINGS SHOW INSTABILITY REMAINING OVER THE EASTERN PART OF THE AREA INTO THE AFTERNOON SO WILL CONTINUE TO HAVE THE HIGHER PRECIP. CHANCES THERE. TOWARD MID AFTERNOON THE LOW LEVELS DRY OUT CAUSING THE CINH TO INCREASE SO WILL ALLOW PRECIP. CHANCES TO DECLINE AS A RESULT. MEANWHILE ATTENTION THEN SHIFTS TO THE WEST WHERE A DRY LINE WILL MOVE INTO THE AREA. WITH LIFT INCREASING OVER THE WEST AS THE DRY LINE MOVES IN AND 700-500MB MIXING RATIOS ALSO INCREASING...AM THINKING STORMS SHOULD DEVELOP ALONG/BEHIND THE DRY LINE. WILL HAVE HIGHER PRECIP. CHANCES MOVE IN FROM THE WEST AS A RESULT. && .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 252 AM MDT SAT MAY 31 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOWS CLOSES LOW STILL IN PLACE OVER SOUTHERN MISSISSIPPI RIVER VALLEY WITH SW FLOW EXTENDING OVER A LONG FETCH FROM THE PACIFIC OCEAN ACROSS THE CENTRAL ROCKIES AND INTO THE NORTHERN GREAT LAKES REGION. A SHORTWAVE TROUGH EMBEDDED WITHIN THE MEAN SW FLOW IS CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE WITH ITS AXIS EXTENDING SOUTH ACROSS OUR CWA. AT THE SURFACE A STATIONARY FRONT IS APPROXIMATELY EXTENDING FROM NORTH CENTRAL NEBRASKA THROUGH EASTERN COLORADO JUST WEST OF THE KS/CO STATE LINE. REGIONAL COMPOSITE RADAR IMAGERY SHOWS A CLUSTER OF ELEVATED SHOWERS/THUNDERSTORMS OVER NEBRASKA EXTENDING SOUTH ACROSS THE EASTERN HALF OF OUR CWA APPROXIMATELY MATCHING THE LEADING EDGE OF THE SHORTWAVE TROUGH AXIS. WE ARE LOOKING AT A PERSISTENT/ACTIVE PATTERN AS SW FLOW CONTINUES TO BRING A SERIES OF STRONG SHORTWAVE TROUGHS ACROSS THE CENTRAL ROCKIES...AND A LONG FETCH OF PACIFIC MOISTURE INTO THE WESTERN PLAINS. ANOMALOUSLY HIGH PWAT VALUES ARE PROGGED TO REMAIN IN PLACE AND TD VALUES GENERALLY AROUND 60F WILL ALSO LINGER. I CANT COMPLETELY RULE OUT SHOWERS/THUNDERSTORMS ALMOST ANY PERIOD...THOUGH MODEL TIMING DOES GENERALLY FAVOR AFTERNOON/EVENING PERIODS...ESPECIALLY ON SUNDAY. WHILE CAPE PROFILES COULD CERTAINLY SUPPORT SEVERE WEATHER JUST ABOUT EVERY PERIOD OF THE SHORT TERM...THE BEST SHEER IS PROGGED FOR SUNDAY/MONDAY...WHEN ORGANIZED SUPER CELLS WILL BE POSSIBLE (MAINLY IN OUR EAST-SOUTHEAST). INCREASING WINDS SUNDAY COULD ACTUALLY APPROACH ADVISORY CRITERIA SUNDAY AFTERNOON (IF NAM SOLUTION WORKS OUT)...HOWEVER THERE IS STILL A LOT OF SPREAD IN THE SURFACE PATTERN. I BUMPED UP POPS/WINDS (ESPECIALLY SUNDAY)...AND ADDED MENTION OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON/EVENING. I CONSIDERED DOING THE SAME FOR MONDAY...HOWEVER I AM LESS CONFIDENT ON MONDAYS PATTERN AT THIS POINT. STILL WORTH MONITORING. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 252 AM MDT SAT MAY 31 2014 SEASONABLE WEATHER PATTERN EXPECTED THROUGH THE REST OF NEXT WEEK. PRECIP CHANCES EXIST MOST DAYS WITH THE BEST CHANCES ON TUESDAY AND THURSDAY. TEMPS WILL BE NEAR TO ABOVE NORMAL UNTIL A COLD FRONT COMES THROUGH MID-WEEK TO DROP TEMPS DOWN TO SLIGHTLY BELOW NORMAL ON THE LARGE SCALE SOUTHWESTERLY FLOW WILL BE PRESENT ACROSS THE REGION TUESDAY AS AN ELONGATED HIGH PRESSURE PERSISTS FROM WEST TEXAS ACROSS NORTHERN MEXICO AND INTO THE PACIFIC. ALL GLOBAL GUIDANCE IS IN SOLD AGREEMENT WITH THIS ASPECT. A WEAK POSITIVELY TILTED TROUGH WILL DEVELOP OVER THE WESTERN CONUS THROUGH NORTHERN CALIFORNIA...AND NUMEROUS SHORTWAVE TROUGHS WILL MOVE ACROSS THE UPPER GREAT BASIN...THROUGH THE CENTRAL/NORTHERN ROCKIES AND INTO THE PLAINS. THE FINE DETAILS OF SPECIFIC SHORTWAVE STRENGTH/TIMING IS NOT CERTAIN...BUT ON THE WHOLE THIS WILL BE A CONTINUATION OF AN ACTIVE WEATHER PATTERN. ON WEDNESDAY A COLD FRONT WILL WORK ITS WAY SOUTH INTO THE REGION BRINGING COOLER AIR IN ITS WAKE...PROBABLY BECOMING A STATIONARY FRONT AND A FOCUS FOR CONVECTION TO FIRE ON LATER IN THE WEEK. TUESDAY COULD BE ONE OF THE HOTTEST DAYS OF THE YEAR SO FAR WITH 850MB TEMPS SOUTH OF I-70 IN THE LOWER TO MID 30S C...WHICH COULD RESULT IN THE HIGHS IN THE MID 90S...AND MAYBE EVEN A FEW LOCATIONS IN THE FAR SOUTH PART OF THE CWA /TRIBUNE AND LEOTI/ APPROACHING TRIPE DIGITS. A STRONG DRY LINE WILL DEVELOP IN EASTERN COLORADO AND PROGRESS EASTWARD DURING THE DAY...SERVING AS A FOCUS FOR AFTERNOON CONVECTION. LARGE SCALE LIFT WILL BE BEST ALONG/NORTH OF I-70...THOUGH MID-LEVEL MOISTURE COULD BE A PROBLEM DESPITE DEW POINTS NEAR 60 AHEAD OF THE DRY LINE. SHEAR IS QUITE IMPRESSIVE LATE TUESDAY WHICH COULD LEAD TO STRONG/SEVERE STORMS. HAVE SOME CONCERN ABOUT CAP HOLDING AS WELL AS AFOREMENTIONED MOISTURE LIMITATIONS SO WILL KEEP POPS SUB-50 PERCENT FOR NOW. WEDNESDAY A COLD FRONT DIPS IN FROM THE NORTH BRINGING COOLER TEMPS. SOME BUST POTENTIAL FOR HIGHS DEPENDING ON TIMING...HIGHS COULD BE ANYWHERE FROM THE MID 70S TO LOW 90S. WEDNESDAY NIGHT INTO THURSDAY DEVELOPING SHORTWAVE TROUGH IN COLORADO MOVING NORTHEAST COULD PROVIDE ENOUGH LIFT FOR SHOWERS/STORMS TO DEVELOP ALONG/NORTH OF THE FRONT. LIMITED CAPE WILL PREVENT STRONG T-STORMS. CHANCE FOR RAIN INCREASES THURSDAY WITH ABUNDANT LOW LEVEL MOISTURE ADVECTING IN FROM THE EAST SUFFICIENT LARGE-SCALE ASCENT. PWATS AROUND AN INCH AND SLOWER STORM MOTIONS COULD RESULT IN LOCALLY HEAVY RAINFALL. CHANCE FOR STORMS CONTINUES INTO FRIDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 522 AM MDT SAT MAY 31 2014 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO LINGER THIS MORNING...MAINLY EAST OF KGLD. KMCK IS MOST LIKELY TO SEE SHOWERS WITHIN THE VICINITY OF THE TERMINAL THIS MORNING...WITH LESS CONFIDENCE IN ISOLATED THUNDER (THOUGH THIS CANT BE RULED OUT). BETTER THUNDERSTORM COVERAGE IS EXPECTED LATER THIS AFTERNOON/EVENING WHEN THE NEXT DISTURBANCE MOVES NEAR THE REGION. I ADDED VCTS TO ACCOUNT FOR THIS. HAVE BEEN MONITORING FOG/STRATUS THIS MORNING AS LIFR CIGS HAVE BE OCCURRING OFF AND ON ALL MORNING AT KGLD... AND NEARBY OB AT KITR SHOWS VIS 1/4SM. THIS DENSE FOG HAS YET TO REACH KGLD WHERE VIS HAS REMAINED IN THE 4-7SM RANGE. GUIDANCE IS DOING A POOR JOB OF HANDLING THE GOOD LOW LEVEL MOISTURE FROM OVER NIGHT PRECIP POOLING ALONG SURFACE FRONT IN EASTERN COLORADO. HAVE KEPT A TEMPO GROUP GOING AT KGLD THIS MORNING FOR CURRENT CIG/VIS TRENDS LOCALLY...AND WILL NEED TO MONITOR TO SEE IF VIS BEGINS TO DETERIORATE. CONFIDENCE FAIRLY LOW RIGHT NOW IN VIS FORECAST FOR THIS MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...JJM AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
529 AM MDT SAT MAY 31 2014 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 252 AM MDT SAT MAY 31 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOWS CLOSES LOW STILL IN PLACE OVER SOUTHERN MISSISSIPPI RIVER VALLEY WITH SW FLOW EXTENDING OVER A LONG FETCH FROM THE PACIFIC OCEAN ACROSS THE CENTRAL ROCKIES AND INTO THE NORTHERN GREAT LAKES REGION. A SHORTWAVE TROUGH EMBEDDED WITHIN THE MEAN SW FLOW IS CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE WITH ITS AXIS EXTENDING SOUTH ACROSS OUR CWA. AT THE SURFACE A STATIONARY FRONT IS APPROXIMATELY EXTENDING FROM NORTHCENTRAL NEBRASKA THROUGH EASTERN COLORADO JUST WEST OF THE KS/CO STATE LINE. REGIONAL COMPOSITE RADAR IMAGERY SHOWS A CLUSTER OF ELEVATED SHOWERS/THUNDERSTORMS OVER NEBRASKA EXTENDING SOUTH ACROSS THE EASTERN HALF OF OUR CWA APPROXIMATELY MATCHING THE LEADING EDGE OF THE SHORTWAVE TROUGH AXIS. WE ARE LOOKING AT A PERSISTENT/ACTIVE PATTERN AS SW FLOW CONTINUES TO BRING A SERIES OF STRONG SHORTWAVE TROUGHS ACROSS THE CENTRAL ROCKIES...AND A LONG FETCH OF PACIFIC MOISTURE INTO THE WESTERN PLAINS. ANOMALOUSLY HIGH PWAT VALUES ARE PROGGED TO REMAIN IN PLACE AND TD VALUES GENERALLY AROUND 60F WILL ALSO LINGER. I CANT COMPLETELY RULE OUT SHOWERS/THUNDERSTORMS ALMOST ANY PERIOD...THOUGH MODEL TIMING DOES GENERALLY FAVOR AFTERNOON/EVENING PERIODS...ESPECIALLY ON SUNDAY. WHILE CAPE PROFILES COULD CERTAINLY SUPPORT SEVERE WEATHER JUST ABOUT EVERY PERIOD OF THE SHORT TERM...THE BEST SHEER IS PROGGED FOR SUNDAY/MONDAY...WHEN ORGANIZED SUPERCELLS WILL BE POSSIBLE (MAINLY IN OUR EAST-SOUTHEAST). INCREASING WINDS SUNDAY COULD ACTUALLY APPROACH ADVISORY CRITERIA SUNDAY AFTERNOON (IF NAM SOLUTION WORKS OUT)...HOWEVER THERE IS STILL A LOT OF SPREAD IN THE SURFACE PATTERN. I BUMPED UP POPS/WINDS (ESPECIALLY SUNDAY)...AND ADDED MENTION OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON/EVENING. I CONSIDERED DOING THE SAME FOR MONDAY...HOWEVER I AM LESS CONFIDENT ON MONDAYS PATTERN AT THIS POINT. STILL WORTH MONITORING. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 252 AM MDT SAT MAY 31 2014 SEASONABLE WEATHER PATTERN EXPECTED THROUGH THE REST OF NEXT WEEK. PRECIP CHANCES EXIST MOST DAYS WITH THE BEST CHANCES ON TUESDAY AND THURSDAY. TEMPS WILL BE NEAR TO ABOVE NORMAL UNTIL A COLD FRONT COMES THROUGH MID-WEEK TO DROP TEMPS DOWN TO SLIGHTLY BELOW NORMAL ON THE LARGE SCALE SOUTHWESTERLY FLOW WILL BE PRESENT ACROSS THE REGION TUESDAY AS AN ELONGATED HIGH PRESSURE PERSISTS FROM WEST TEXAS ACROSS NORTHERN MEXICO AND INTO THE PACIFIC. ALL GLOBAL GUIDANCE IS IN SOLD AGREEMENT WITH THIS ASPECT. A WEAK POSITIVELY TILTED TROUGH WILL DEVELOP OVER THE WESTERN CONUS THROUGH NORTHERN CALIFORNIA...AND NUMEROUS SHORTWAVE TROUGHS WILL MOVE ACROSS THE UPPER GREAT BASIN...THROUGH THE CENTRAL/NORTHERN ROCKIES AND INTO THE PLAINS. THE FINE DETAILS OF SPECIFIC SHORTWAVE STRENGTH/TIMING IS NOT CERTAIN...BUT ON THE WHOLE THIS WILL BE A CONTINUATION OF AN ACTIVE WEATHER PATTERN. ON WEDNESDAY A COLD FRONT WILL WORK ITS WAY SOUTH INTO THE REGION BRINGING COOLER AIR IN ITS WAKE...PROBABLY BECOMING A STATIONARY FRONT AND A FOCUS FOR CONVECTION TO FIRE ON LATER IN THE WEEK. TUESDAY COULD BE ONE OF THE HOTTEST DAYS OF THE YEAR SO FAR WITH 850MB TEMPS SOUTH OF I-70 IN THE LOWER TO MID 30S C...WHICH COULD RESULT IN THE HIGHS IN THE MID 90S...AND MAYBE EVEN A FEW LOCATIONS IN THE FAR SOUTH PART OF THE CWA /TRIBUNE AND LEOTI/ APPROACHING TRIPE DIGITS. A STRONG DRYLINE WILL DEVELOP IN EASTERN COLORADO AND PROGRESS EASTWARD DURING THE DAY...SERVING AS A FOCUS FOR AFTERNOON CONVECTION. LARGE SCALE LIFT WILL BE BEST ALONG/NORTH OF I-70...THOUGH MID-LEVEL MOISTURE COULD BE A PROBLEM DESPITE DEW POINTS NEAR 60 AHEAD OF THE DRYLINE. SHEAR IS QUITE IMPRESSIVE LATE TUESDAY WHICH COULD LEAD TO STRONG/SEVERE STORMS. HAVE SOME CONCERN ABOUT CAP HOLDING AS WELL AS AFOREMENTIONED MOISTURE LIMITATIONS SO WILL KEEP POPS SUB-50 PERCENT FOR NOW. WEDNESDAY A COLD FRONT DIPS IN FROM THE NORTH BRINGING COOLER TEMPS. SOME BUST POTENTIAL FOR HIGHS DEPENDING ON TIMING...HIGHS COULD BE ANYWHERE FROM THE MID 70S TO LOW 90S. WEDNESDAY NIGHT INTO THURSDAY DEVELOPING SHORTWAVE TROUGH IN COLORADO MOVING NORTHEAST COULD PROVIDE ENOUGH LIFT FOR SHOWERS/STORMS TO DEVELOP ALONG/NORTH OF THE FRONT. LIMITED CAPE WILL PREVENT STRONG T-STORMS. CHANCE FOR RAIN INCREASES THURSDAY WITH ABUNDANT LOW LEVEL MOISTURE ADVECTING IN FROM THE EAST SUFFICIENT LARGE-SCALE ASCENT. PWATS AROUND AN INCH AND SLOWER STORM MOTIONS COULD RESULT IN LOCALLY HEAVY RAINFALL. CHANCE FOR STORMS CONTINUES INTO FRIDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 522 AM MDT SAT MAY 31 2014 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO LINGER THIS MORNING...MAINLY EAST OF KGLD. KMCK IS MOST LIKELY TO SEE SHOWERS WITHIN THE VICINITY OF THE TERMINAL THIS MORNING...WITH LESS CONFIDENCE IN ISOLATED THUNDER (THOUGH THIS CANT BE RULED OUT). BETTER THUNDERSTORM COVERAGE IS EXPECTED LATER THIS AFTERNOON/EVENING WHEN THE NEXT DISTURBANCE MOVES NEAR THE REGION. I ADDED VCTS TO ACCOUNT FOR THIS. HAVE BEEN MONITORING FOG/STRATUS THIS MORNING AS LIFR CIGS HAVE BE OCCURRING OFF AND ON ALL MORNING AT KGLD... AND NEARBY OB AT KITR SHOWS VIS 1/4SM. THIS DENSE FOG HAS YET TO REACH KGLD WHERE VIS HAS REMAINED IN THE 4-7SM RANGE. GUIDANCE IS DOING A POOR JOB OF HANDLING THE GOOD LOW LEVEL MOISTURE FROM OVER NIGHT PRECIP POOLING ALONG SURFACE FRONT IN EASTERN COLORADO. HAVE KEPT A TEMPO GROUP GOING AT KGLD THIS MORNING FOR CURRENT CIG/VIS TRENDS LOCALLY...AND WILL NEED TO MONITOR TO SEE IF VIS BEGINS TO DETERIORATE. CONFIDENCE FAIRLY LOW RIGHT NOW IN VIS FORECAST FOR THIS MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JJM AVIATION...DR
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
735 AM EDT SAT MAY 31 2014 .UPDATE... ISSUED AT 725 AM EDT SAT MAY 31 2014 THE LATEST VISIBLE SATELLITE IMAGERY SHOWS THE TENDRILS OF FOG THROUGH THE SOUTHERN RIVER VALLEYS ACROSS EAST KENTUCKY. THIS WILL DISSIPATE OVER THE NEXT HOUR OR SO. OTHERWISE...THE FORECAST IS RIGHT ON TRACK WITH JUST A FEW NUDGES PER THE LATEST OBS AND TRENDS. THESE ADJUSTMENTS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 400 AM EDT SAT MAY 31 2014 07Z SFC ANALYSIS SHOWS HIGH PRESSURE EASING INTO NORTHEAST KENTUCKY BRINGING A DRIER AIR MASS TO THAT PART OF THE STATE. ON SATELLITE...A WISP OF HIGH CLOUDS REMAINS OVER THIS TRANSITION ZONE BETWEEN THIS DRIER AIR AND THE MORE HUMID CONDITIONS TO THE SOUTHWEST. TEMPERATURES ARE A BIT COOLER IN THE NORTHEAST...TOO...BUT MAINLY A RIDGE TO VALLEY DIFFERENCE IS NOTED THERE AND TO A LESSER EXTENT OVER THE REST OF THE CWA. MOISTURE VARIES MORE BROADLY WITH LOW TO MID 60S DEWPOINTS FOUND TO THE SOUTH AND WEST OF JKL WHILE MID 50S ARE MOVING INTO THE NORTHEAST. WINDS ARE LIGHT AND VARIABLE ACROSS THE CWA THIS NIGHT. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A RIDGE OF HIGH PRESSURE OVER THE WESTERN OHIO VALLEY SOUTHEAST TO THE ATLANTIC COAST WHILE ONE DEEP CLOSED LOW IS MOVING AWAY TO THE NORTHEAST OF KENTUCKY AND ANOTHER WEAKER ONE FILLING OVER THE WEST CENTRAL GULF COAST. IN TIME...THE RIDGE SETTLES OVER EAST KENTUCKY KEEPING ALL THE ENERGY NORTH AND WEST OF EAST KENTUCKY. THE RIDGE DOES WEAKEN QUICKLY... THOUGH...AS IT SINKS TO THE SOUTHEAST ON SUNDAY. THIS SHOULD BE ENOUGH TO ALLOW A BIT MORE MID LEVEL ENERGY TO SEEP INTO KENTUCKY BY SUNDAY EVENING. GIVEN THE GOOD MODEL AGREEMENT HAVE FOLLOWED THE SPECIFICS FROM THE NAM12 AND HRRR MOST CLOSELY FOR THE SHORT TERM PORTION OF THE FORECAST. SENSIBLE WEATHER WILL FEATURE PATCHY VALLEY FOG...LOCALLY DENSE... BURNING OFF BY MID MORNING SETTING THE STAGE FOR A SUNNY...QUIET... AND WARM DAY UNDER RIDGING ALOFT AND SFC HIGH PRESSURE. A FEW MORE CLOUDS WILL ARRIVE LATER TONIGHT AS MOISTURE SEEPS BACK IN FROM THE SOUTHWEST. FOR SUNDAY THERE WILL BE A POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS BY EVENING WITH THE BETTER CHANCES LOCATED OVER THE CUMBERLAND VALLEY. OTHERWISE...WARM AND INCREASINGLY HUMID WEATHER WILL CLOSE OUT THE WEEKEND. USED THE BCCONSSHORT/ALL AS A STARTING POINT FOR TEMPERATURES... DEWPOINTS...AND WINDS. DID MAKE ADJUSTMENTS TO THESE TONIGHT FOR MORE OF A RIDGE TO VALLEY TEMP SPLIT. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF MOS GUIDANCE LATER SUNDAY THROUGH THE CWA...OTHERWISE KEPT THEM IN THE SINGLE DIGITS. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 340 AM EDT SAT MAY 31 2014 LOOKS TO BE A FAIRLY ACTIVE PATTERN...WITH A LOT OF DIURNALLY DRIVEN CONVECTION DURING THE EXTENDED. STARTING AT 0Z MONDAY...KY WILL FIND ITSELF BETWEEN AN UPPER LEVEL RIDGE MOVING OFF THE SE COAST...AND A LOW OVER LOUISIANA CONTINUING SOUTHWARD INTO THE GULF. BEING WEDGED BETWEEN THE TWO...THE FLOW ACROSS KY WILL FEATURE WARM MOIST SOUTHERN AIR OFF THE GULF. A STRONG COLD FRONT WILL ALSO STRETCH FROM THE SOUTHERN PLAINS INTO THE UPPER GREAT LAKES REGION...WITH DECENT LIFT AND A LARGE PRECIP SHIELD. DIURNAL HEATING DURING THE DAY SUNDAY WILL BRING CONVECTION TO MUCH OF THIS MOISTURE CONVEYOR BELT FROM THE GULF TO THE COLD FRONT TO OUR NE. THIS INCLUDES SHOWERS AND THUNDERSTORMS FOR MUCH OF WESTERN AND PORTIONS OF CENTRAL KY. HOWEVER...EACH MODEL RUN HAS A SLIGHTLY DIFFERENT SOLUTION FOR EASTERN KY...BEING ON THE EASTERN FRINGE OF THE BEST CONVECTION. EXPECT BY 0Z MONDAY...THIS CONVECTION WILL BE ONGOING BUT DYING OUT WITH LOSS OF DAYTIME HEATING. RAISED POPS BOTH SUNDAY /SHORT TERM/ AND SUNDAY EVENING FROM PREVIOUS. THE REST OF THE NIGHT WILL FEATURE HUMID CONDITIONS BUT DYING CONVECTION...WITH ANOTHER RAMP UP FOR AFTERNOON CONVECTION POSSIBLE DURING THE DAY MONDAY. CONVECTION WILL BE AIDED BY THE FACT THAT THE COLD FRONT WILL HAVE SHIFTED SEWARD...EDGING SLIGHTLY CLOSER TO THE OHIO RIVER VALLEY...AND ALLOWING THE BEST MOISTURE FLOW TO SHIFT SLIGHTLY EASTWARD AS WELL...PUTTING MUCH OF KY INTO THE MOIST UNSTABLE FLOW. BY 12Z TUESDAY...THE FRONT WILL BEGIN TO TRAVERSE THE STATE...BRINGING LIKELY POPS INTO EASTERN KY BY AFTERNOON. MODEL SOLUTIONS ON THE EXACT TIMING OF ENTRANCE AND EXIT ARE STILL SOMEWHAT LACKING...BUT EXPECT A FAIRLY GOOD LINE OF SHOWERS AND THUNDERSTORMS TO PASS THROUGH DURING THE PEAK OF THE AFTERNOON...THEN GET CUT OFF BY DRY AIR BEHIND THE FRONT AND LOSS OF DIURNAL HEATING OVERNIGHT. LATEST MODEL GUIDANCE IS PICKING UP ON WHAT APPEARS TO BE A SECONDARY FRONT DEVELOPING AND FOLLOWING IN THE FOOTSTEPS OF ITS PREDECESSOR...BRINGING YET ANOTHER BOUGHT OF CONVECTIVE PRECIP TO THE REGION WEDNESDAY. OVERALL MODEL UNCERTAINTY OF TIMING AND SET UP WILL LEAD TO STICKING CLOSE TO THE ALLBLEND SOLUTION FROM THIS POINT FORWARD. ANOTHER...WEAKER LOW WILL PASS THROUGH SOMETIME THURSDAY. AT THIS POINT...BOTH THE GEM AND ECMWF SHOW THE MAIN LOW AND PRECIP MOVING JUST NORTH OF KY...WITH SOME WARRANTED SLIGHT CHANCE POPS ACROSS THE NORTHERN CWA. HOWEVER...THE GFS...WHICH THE ALLBLEND LEANS MORE HEAVILY ON...SHOWS THIS LOW PASSING THROUGH THE STATE...AND BRINGING A GOOD DUMP OF PRECIP ONCE MORE THURSDAY MORNING AND THROUGH THE DAY. REGARDLESS...AFTERNOON HEATING AND PROXIMITY TO INSTABILITY AND MOISTURE INFLUX SHOULD BE ENOUGH TO SPAWN SOME SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON SO KEPT WITH THE CHANCE POPS THAT WERE GIVEN. A SIMILAR SITUATION WILL OCCUR ON FRIDAY AS ANOTHER SHORTWAVE DEVELOPS. THE TRACK OF THE SHORTWAVE...THOUGH STILL RATHER UNDETERMINED...WILL MAKE THE DIFFERENCE BETWEEN WIDESPREAD RAIN AND THUNDERSTORMS FRIDAY INTO SATURDAY...OR MORE DIURNALLY DRIVEN SCATTERED CONVECTION. ONCE AGAIN...CONFIDENCE WARRANTS LEANING TOWARDS THE ALLBLEND SOLUTION FOR THE END OF THE EXTENDED. WITH NO DRASTIC CHANGES IN THE OVERALL UPPER LEVEL PATTERN DURING THE EXTENDED...EXPECT TEMPERATURES TO REMAIN RATHER UNIFORM. HIGHS SHOULD REACH THE LOW TO MID 80S DURING THE AFTERNOON...AND DROP INTO THE 60S OVERNIGHT. KEPT WITH A DIURNAL TEMPERATURE CURVE THROUGH THE EXTENDED...AS EVEN THE IMPACTING FRONTS SHOULD CORRELATE WITH THE DIURNAL CYCLE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 735 AM EDT SAT MAY 31 2014 FOR THE MOST PART VFR CONDITIONS ARE EXPECTED THROUGH THE AVIATION PERIOD ACROSS THE CWA. THERE WILL BE SOME MVFR OR LOWER VALLEY FOG AROUND EARLY THIS MORNING...SOUTH AND WEST OF JKL WHERE THE DEWPOINT DEPRESSIONS REMAIN LOWEST. THE FOG SHOULD LIFT AND DISSIPATE BY AROUND 13Z...WITH NOTHING MORE THAN A FEW PASSING HIGH CLOUDS THROUGH THE BULK OF THE PERIOD. LOOK FOR MORE MID AND LOWER LEVEL CLOUDS TO ARRIVE FROM THE SOUTHWEST LATE TONIGHT IN ADVANCE OF A RENEWED PICKUP IN MOISTURE. MEANWHILE...WINDS WILL REMAIN LIGHT AND VARIABLE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
848 AM EDT SAT MAY 31 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY AND TONIGHT. THE HIGH PRESSURE MOVES IN THE GULF OF MAINE LATE SUNDAY. LOW PRESSURE APPROACHES FROM THE WEST ON TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... 848 AM UPDATE...THE LOW LEVELS WILL CONTINUE TO DRY OUT FROM THE NE ACROSS THE CWA TODAY AS HIGH PRES BUILDS ACROSS THE REGION. DEW POINTS WHICH ARE MOSTLY IN THE 40S THIS MORNING WILL DROP INTO THE 30S THIS AFTERNOON. LOW STRATUS AND PATCHY FOG IS RAPIDLY DISSIPATING THIS MORNING. THE LAST OF THE STRATUS ALONG COASTAL WASHINGTON COUNTY SHOULD LIFT WITHIN THE HOUR. AS POINTED OUT BY THE MIDNIGHT CREW THE CHANCE OF A SHOWER THIS AFTERNOON APPEARS SMALL...BUT THE HRRR DOES INDICATE A COUPLE OF VERY ISOLATED SHOWERS MID-LATE AFTERNOON ACROSS THE EASTERN ZONES. AT THIS TIME WILL NOT MAKE ANY CHANGES TO THE ONGOING FORECAST WHICH HAS ISOLATED SHOWERS THIS AFTERNOON. ONLY MINOR TWEAKS TO THE FORECAST BASED ON THE LATEST SATELLITE TRENDS AND OBSERVATIONS. PREVIOUS DISCUSSION...SOME LINGERING LOW CLOUDS AND FOG AS THE SUN RISES TODAY, BUT EXPECT ANY FOG TO DISSIPATE AND CLOUDS DECREASE AS THE MORNING GOES ON AS DRIER AIR MOVES IN FROM THE NORTHEAST. CANNOT RULE OUT AN ISOLATED AFTERNOON SHOWER OVER NORTHEAST MAINE, BUT OTHERWISE LOOKS DRY TODAY. HIGH PRESSURE BECOMES CENTERED OVER MAINE TONIGHT WITH MOSTLY CLEAR SKIES. EXPECT GOOD RADIATIONAL COOLING ESPECIALLY FAR EAST/SOUTHEAST AREAS WHERE THE SURFACE HIGH WILL LIKELY BE CENTERED. COULD BE SOME FROST BUT IT WILL BE MARGINAL. OPTED TO HOLD OFF ON ANY FROST ADVISORIES FOR NOW, BUT SOME MAY BE NEEDED. && .SHORT TERM /SUNDAY THROUGH MONDAY/... STRONG HIGH PRESSURE IS CENTERED OVER THE MID ATLANTIC STATES SUNDAY MORNING AND RIDGES NORTHWARD ACROSS NEW ENGLAND. THIS SYSTEM THEN DRIFTS TO THE SOUTH AND EAST BY MONDAY MORNING. HAVE BLENDED THE NAM ...GFS ...SREF AND ECMWF FOR POPS AND QPF. FOR SKY USED THE NAM ...GFS AND ECMWF. FOR SUSTAINED WIND SPEED HAVE USED THE GMOS. TEMPERATURE FROM THE BIAS CORRECTED CONSENSUS ALL. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... LOW PRESSURE IS EXPECTED TO MOVE FROM THE GREAT LAKES MONDAY EVENING THEN NORTHEAST INTO WESTERN QUEBEC PROVINCE TUESDAY EVENING WITH A WARM FRONT APPROACHING THE LOCAL AREA. AS THE LOW PASSES TO THE NORTH OF THE STATE A COLD FRONT WILL MOVE ACROSS THE REGION WEDNESDAY NIGHT. HIGH PRESSURE IS THEN EXPECTED TO APPROACH FROM THE WEST THURSDAY INTO FRIDAY. HAVE USED THE SUPPER BLEND TO INITIALIZED ALL GRIDS. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: THE LOW STRATUS AND PATCH FOG IS VERY RAPIDLY DISSIPATING THIS MORNING. ALL AREAS ARE EXPECTED TO BE VFR VFR BY 14Z. VFR CONTINUES TON. SHORT TERM: VFR CONDITIONS ARE EXPECTED SUNDAY THROUGH TUESDAY. IFR/MVFR CONDITIONS EXPECTED WEDNESDAY AND THURSDAY. && .MARINE... NEAR TERM: CONDITIONS REMAINING BELOW SMALL CRAFT LEVELS THROUGH TONIGHT. LOW STRATUS AND FOG SHOULD DISSIPATE BY LATE MORNING. SHORT TERM: HAVE USED THE SREF FOR SUSTAINED WIND SPEED. FOR WAVES: LOW PRESSURE PERSIST OVER THE ATLANTIC WELL TO THE SOUTHEAST OF THE GULF OF MAINE INTO LATE MONDAY. FLOW TO THE NORTH OF THIS SYSTEM IS GENERATING NORTHEASTERLY LONG PERIOD WAVE SYSTEM 2-3 FEET BUILDING TO 3-4 FEET/8-9 SECONDS. THIS IS ACCOMPANIED BY SOUTHEASTERLY LONG PERIOD WAVES AROUND 1-2 FEET/9-11 SECONDS. WITH LIGHT WINDS EXPECTED INTO EARLY NEXT WEEK EXPECT THESE WAVE SYSTEMS TO PREDOMINATE. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...CB/FOISY SHORT TERM...MIGNONE LONG TERM...MIGNONE AVIATION...CB/FOISY/MIGNONE MARINE...CB/FOISY/MIGNONE
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
614 AM EDT SAT MAY 31 2014 .SYNOPSIS... A TROUGH OF LOW PRESSURE LINGERS OVER THE REGION TODAY PRODUCING SCATTERED SHOWERS. HIGH PRESSURE STRENGTHENS OVER NEW ENGLAND SUNDAY AND MONDAY. A WARM FRONT MOVES INTO THE REGION MONDAY NIGHT. LOW PRESSURE PASSES THROUGH SOUTHERN CANADA TUESDAY AND WEDNESDAY DRAGGING A FRONT INTO NEW ENGLAND MIDWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .UPDATE... MINOR CHANGES TO SKY...TEMPERATURES AND DEW POINTS FOR THIS UPDATE. FOG AND STRATUS ARE STILL MOVING ALONG THE COAST AND THE INTERIOR. SHOWERS ARE FILLING IN SLIGHTLY FROM RANGELEY TO NORTH CONWAY AND TO CONCORD AND MOVING WEST. && PREVIOUS DISCUSSION... WEAK TROUGH OF LOW PRESSURE REMAINS OVER NORTHERN NEW ENGLAND THIS MORNING WITH LATEST MSAS ANALYSIS SHOWING THE MESOLOW CENTER NEAR MOOSEHEAD LAKE. LATEST HRRR FORECAST HAS THIS FEATURE DRIFTING WESTWARD THROUGH THE MORNING WITH A FEW SHOWERS BREAKING OUT WITH THE HELP OF OROGRAPHIC LIFT AND ALSO OFFSHORE AND NEAR BOSTON... WHICH IS ALREADY OCCURRING. AS DAYTIME HEATING INCREASES ... MORE SHOWERS WILL ERUPT OVER THE FOOTHILLS AND HIGHER TERRAIN WITH CHANCE COVERAGE OVER ALL OF NEW HAMPSHIRE THROUGH NOON OR SO BEFORE FORCING DISAPPEARS. SAID FORCING IS THE SHORT WAVE ENERGY CURRENTLY OVER SOUTHERN QUEBEC THAT WILL SERVE TO CUT OFF THE UPPER LOW JUST OFFSHORE. THE SURFACE TROUGH WILL WASH OUT WITH SKIES BECOMING MOSTLY SUNNY THIS AFTERNOON. TEMPERATURES WILL REACH THE UPPER 60S AREAWIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... CONTINENTAL HIGH PRESSURE SHIFTS IN FROM THE NORTH TONIGHT AND DEW POINTS AND WINDS TAKE A NOSE DIVE. PW VALUES DROP TO ABOUT THE 15% PERCENTILE. THIS WILL NOT ONLY FOSTER CONDITIONS FOR FOG BUT ALSO FROST. THE HIGHER TERRAIN AS WELL AS FAVORED LOW SPOTS WILL DROP BELOW FREEZING. FROST WILL LIKELY BE WIDESPREAD ENOUGH FOR ADVISORIES TO BE ISSUED FOR MUCH OF THE NORTH COUNTRY. THIS WILL BE ADDRESSED IN THE NEXT FORECAST PACKAGE LATER TODAY. FREEZING FOG MAY ALSO BE AN ISSUE PRODUCING SLICK SPOTS ON ROADWAYS. ELSEWHERE LOWS WILL BOTTOM OUT INTO THE UPPER 30S TO MID 40S. SUNDAY WILL START OUT CHILLY BUT THE DRY AIRMASS WILL ALLOW TEMPERATURES TO CLIMB QUICKLY INTO THE MID TO UPPER 70S AREAWIDE BY THE AFTERNOON. NO PRECIPITATION IS FORECAST WITH HIGH PRESSURE CONTINUING TO STRENGTHEN. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... UPPER RIDGE OVER THE NORTHEAST BEGINS TO BREAK DOWN A BIT AND SURFACE HIGH PRESSURE SHIFTS TO THE SOUTH. THIS WILL BRING A WESTERLY FLOW TO NORTHERN NEW ENGLAND... ADVECTING WARM AIR INTO THE AREA. SHOULD SEE TEMPERATURES WARMING INTO THE UPPER 70S AND LOW 80S EVEN CLOSER TO THE COAST ON MONDAY. LATE IN THE DAY ON MONDAY SOME SHOWERS MAY PUSH INTO THE NORTHERN PART OF THE AREA AS A SHORTWAVE TROUGH CROSSES OVER THE TOP OF THE RIDGE AND DOWN INTO MAINE. UPPER TROUGH MOVING OUT OF THE NORTHERN PLAINS AND INTO THE GREAT LAKES WILL GRADUALLY EXERT ITS INFLUENCE OVER NEW ENGLAND WEATHER. BY TUESDAY... SURFACE WINDS WILL SHIFT TO THE EAST OR SOUTHEAST... BRINGING A COOLER MARINE INFLUENCE ESPECIALLY TO THE EAST OF THE MOUNTAINS. SO IN SPITE OF WARMER TEMPERATURES STILL EXISTING ALOFT... THE WARM AIR WILL NOT BE FULLY FELT AT THE SURFACE ACROSS MOST OF MAINE AND EASTERN NEW HAMPSHIRE. HIGHS WILL ONLY REACH THE 60S. FURTHER WEST... MID TO UPPER 70S ARE EXPECTED. WITH THE SURFACE LOW TRACKING WELL TO THE NORTH TOWARD JAMES BAY IN CANADA... AN OCCLUDED FRONT WILL TRY TO PUSH EASTWARD INTO THE FORECAST AREA. THIS WILL LEAD TO A GREATER CHANCE OF SHOWERS ON TUESDAY. THERE WILL LIKELY EXIST A CORRIDOR OF INSTABILITY JUST AHEAD OF THE FRONT ALLOWING FOR THE DEVELOPMENT OF THUNDERSTORMS AS WELL. UPPER TROUGH AXIS REMAINS TO THE WEST OF THE AREA... WITH SEVERAL EMBEDDED SHORTWAVE TROUGHS EXPECTED TO BRING A CHANCE FOR SHOWERS TO THE REGION FOR WEDNESDAY AND THURSDAY. SHOULD SEE A LITTLE IMPROVEMENT BY FRIDAY AS THE UPPER TROUGH FINALLY SHIFTS EAST. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM...PATCHY DENSE FOG THIS MORNING WILL LIFT LATER THIS MORNING SIMILAR TO YESTERDAY. GUSTY N TO NE WINDS WILL DEVELOP BY MID MORNING. EXPECT ANOTHER ROUND OF DENSE FOG SUNDAY MORNING. LONG TERM...GENERALLY VFR UNTIL MONDAY NIGHT WHEN A MOIST EAST OR SOUTHEAST FLOW MAY BRING LOWER CLOUDS BACK INTO THE AREA. IFR CONDITIONS ARE POSSIBLE WITH SOME IMPROVEMENT POSSIBLE DURING THE DAY TUESDAY. SHOWERS AND A MOIST ONSHORE FLOW ON TUESDAY AND WEDNESDAY WILL MAINTAIN A THREAT FOR MVFR OR IFR CONDITIONS. && .MARINE... SHORT TERM...NO FLAGS ON THE WATERS. LONG TERM...HIGH PRESSURE OVER THE WATERS KEEPS CONDITIONS FAIRLY TRANQUIL. FLOW EVENTUALLY TURNS TO THE SOUTH BY TUESDAY BUT SHOULD REMAIN BELOW ADVISORY LEVELS. WAVE MODELS CONTINUE TO SHOW 5+ FT SWELLS MOVING INTO THE GULF OF MAINE SUNDAY NIGHT AND MONDAY LIKELY ASSOCIATED WITH LOW PRESSURE WELL TO THE SOUTHEAST. HOWEVER... THERE IS CONSIDERABLE DOUBT THAT WAVE HEIGHTS WILL BE THIS HIGH. EVEN SO... THE LONG PERIOD WILL LIKELY MAKE THE IMPACT OF THESE WAVES FAIRLY MINOR AND AN ADVISORY WILL NOT LIKELY BE NEEDED. && .FIRE WEATHER... LIGHT PRECIPITATION IS POSSIBLE TODAY...MOSTLY OVER THE MOUNTAINS AND FOOTHILLS THIS MORNING AS A TROUGH OF LOW PRESSURE MOVES WEST. LIGHT WINDS AND RECENT RAIN SHOULD KEEP FIRE WEATHER CONCERNS LOW. HIGH PRESSURE BUILDS OVER THE REGION SUNDAY BRINGING DRIER CONDITIONS TO THE REGION. MINIMUM RH VALUES DROP TO NEAR 25-35% BY THE AFTERNOON AS TEMPERATURES REACH THE MID TO UPPER 70S. WINDS WILL BE LIGHT. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ HANES/KIMBLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
624 AM CDT SAT MAY 31 2014 .UPDATE... ISSUED AT 623 AM CDT SAT MAY 31 2014 THE BAND OF SHOWERS ASSOCIATED WITH MID LEVEL FG FORCING IS SLOWLY SHIFTING EAST AND HOLDING TOGETHER WHILE THE SOUTHERN END SPREADING EASTWARD IN COVERAGE...SOON TO MERGE WITH SHOWERS/STORMS MOVING NORTHEAST OUT OF SD. WILL CONTINUE LIKELY POPS ALONG THIS NORTHERN BAND THROUGHOUT THE MORNING. SHORT WAVE OVER NORTHEASTERN COLORADO HAS KICKED OUT INTO PANHANDLE OF NEBRASKA AND WILL ARRIVE OVER SOUTHERN CWA BY AFTERNOON. THIS WILL PROVIDE SUFFICIENT LARGE SCALE ASCENT TO INTERACT WITH SFC BOUNDARY AND STRENGTHEN SHOWERS/STORMS ESPECIALLY OVER SOUTHEASTERN CWA. 06Z GFS NOW SHOWING TWO BANDS OF SHOWERS (ONE ALONG SFC BNDRY AND OTHER ALONG MID LEVEL FG BOUNDARY)...AS WELL AS LATEST HRRR AND 06Z NAM. ALSO HAVE SEEN SOME PATCHY FOG ALONG AND NORTH OF THE HWY 2 CORRIDOR BETWEEN GFK AND DVL...AND HAVE ADDED PATCHY FOG TO PORTIONS OF NORTHEASTERN ND. NO OTHER CHANGES FOR THIS FCST UPDATE. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 413 AM CDT SAT MAY 31 2014 MAIN FORECAST CHALLENGES FOR THE NEAR TERM WILL BE PLACEMENT OF REDEVELOPING RAIN SHOWERS AND THUNDERSTORMS TODAY. CURRENT ACTIVITY HAS WEAKENED OR SHIFTED TO THE EAST AS H850 LLJ TURNS MORE WESTERLY AND WEAKENS BY 12Z. THE MAIN SFC BOUNDARY IS GENERALLY OVER THE FAR SOUTHEAST ALTHOUGH THERE IS SOME WEAK SFC CONVERGENCE OVER RED LAKE ND WESTERN POLK COUNTY...BUT THE MAIN FORCING OVER THE CENTRAL AND NORTHERN VALLEY WILL BE MID LEVEL FRONTOGENESIS. OVERALL MODELS TARGET SERN HALF OF CWA BUT EXACT PLACEMENT OF PRECIP IS STILL QUITE VARIABLE. THROUGH 18Z...GENERALLY WILL FOLLOW THE 4KM WRF AND A MODEL BLEND FOR THE AFTERNOON AND TONIGHT. TODAY...CONVECTIVE ACTIVITY OVER NORTHEASTERN SD WILL GRADUALLY SPREAD ACROSS THE SOUTHERN VALLEY AND UP INTO WADENA...POLK...OTTER TAIL AND GRANT COUNTIES. DO EXPECT DRY AREA ALONG AND SOUTHEAST OF A CARRINGTON-LAKOTA- CAVALIER LINE TO FILL IN THIS MORNING...ESPECIALLY OVER SOUTHEASTERN ND...AS BAND OF MID LEVEL FG FORCING SHIFTS EAST (AND AREA OF CONVECTION LIFTS NORTH). HOWEVER THIS ACTIVITY WILL GENERALLY BE WEAK AND BEST CHANCE FOR MODERATE RAIN SHOWERS AND CONVECTION WILL BE ACROSS THE SOUTHEAST WHERE THERE REMAINS SOME LLJ INFLUENCE. BEYOND 18Z MODELS VARY ON PLACEMENT OF PRECIP. OVERALL PREFER A GFS/ECMWF BLEND WHICH KEEPS THE DEVILS LAKE BASIN AND NORTHERN VALLEY FAIRLY DRY. TONIGHT...MODELS CONTINUE TO DRY OVER NORTHWESTERN HALF OF CWA AND CHALLENGE WILL BE PLACEMENT OF MODERATE RAINFALL AS MODELS CONTINUE TO VARY ON LOCATION. GFS ACTUALLY DRIES OUT MOST OF AREA IN THE 06Z TO 12Z TIMEFRAME WHEREAS THE NAM IS QUITE BULLISH OVER MY EAST CNTRL ZONES AND THE GEM/ECMWF CONTINUE TO TARGET THE SOUTHEAST. EXPECT THE MAIN ACTIVITY...HOWEVER...TO SHIFT EASTWARD OUT OF THE CWA BY 12Z SUNDAY. SUNDAY...THE NEXT WAVE OF SHOWERS AND THUNDERSTORMS WILL BEGIN TO LIFT NORTH AS A SECOND UPPER WAVE MOVES ACROSS THE DAKOTAS. WILL LIKELY SEE A BREAK ACROSS MUCH OF THE AREA EARLY SUNDAY...WITH SHOWERS THEN LIFTING NORTH AND EAST OUT OF THE CNTRL DAKOTAS SUN AFTN. OVERALL TWO TO THREE INCHES OF RAINFALL IS POSSIBLE ACROSS THE SOUTHEASTERN ZONES BY THE TIME THIS SECOND WAVE MOVES OUT ON MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 413 AM CDT SAT MAY 31 2014 SUN NIGHT AND MONDAY...SECOND WAVE OF SHOWERS SPREAD ACROSS EASTERN DAKOTAS AS ANOTHER UPPER WAVES MOVES INTO NORTHERN TIER FROM THE SW. SURFACE LOW MOVES OVER MINNESOTA WITH INVERTED TROUGH EXTENDING ACROSS THE NORTHERN VALLEY...KEEPING PRECIP GOING ACROSS MAINLY THE NORTHERN CWA AND LOWER CHANCES ACROSS THE SOUTH. THE NAMDNG GUIDANCE IS GOING SIGNIFICANTLY COOLER ACROSS NORTHEASTERN ND MON...WITH DAYTIME HIGHS IN THE MID 50S. WITH MODERATE TO HEAVY RAIN SHOWERS POSSIBLE ALONG THE INVERTED TROUGH...COULD SEE RAINFALL IMPACT TEMPS TO THAT DEGREE AND WILL TREND TEMPS DOWN BUT NOT QUITE THAT DRASTIC YET AS MODELS STILL DIFFER ON EXACT PLACEMENT OF PRECIP FOR DAY 3. MON NIGHT...HIGH PRESSURE WILL FINALLY WORK ITS WAY INTO THE WRN DAKOTAS AND WE SHOULD SEE PRECIP ACROSS THE EASTERN DAKOTAS DISSIPATE EARLY IN THE EVENING. BOTH THE NAM AND GEM ARE QUICKER (GEM IS THE FASTEST) IN ENDING PRECIP ACROSS THE DAKOTAS WHILE THE GFS/ECMWF HOLD ON THROUGH MIDNIGHT. SHOWALTERS BEGIN TO INCREASE SIGNIFICANTLY ACROSS ALL BUT MY SOUTHEAST...SO CHANGED PREDOMINANT PRECIP TYPE TO RAIN SHOWERS WITH ISOLATED TSTMS. LOOK FOR ACTIVITY TO DECLINE ACROSS THE EASTERN PORTION OF THE CWA BETWEEN 06Z AND 12Z TUESDAY. FOR TUE THROUGH FRI NIGHT...IT SHOULD DRY OUT ON TUE WITH A FEW LINGERING SHOWERS/STORMS IN THE FAR EAST MAINLY TUE MORNING. IT SHOULD BE DRY TUE NIGHT THROUGH WED NIGHT IN ALL AREAS. BY THU AND FRI...A MORE ACTIVE PATTERN COULD ONCE AGAIN DEVELOP...WITH THE CHANCES FOR SHOWERS AND STORMS. TEMPS SHOULD BE NEAR NORMAL WITH A COOLER AIRMASS THAN WE HAVE HAD OVER THE PAST WEEK OR SO. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 623 AM CDT SAT MAY 31 2014 FOG AT DVL WILL GRADUALLY IMPROVE THIS MORNING AND SITE SHOULD BE VFR BY NOON. GFK/TVF WILL SEE MVFR CIGS THROUGH THE DAY AS SHOWERS DEVELOP LATER THIS MORNING OVER NORTHEASTERN ND AND ADVECT INTO NW MINNESOTA. FAR AND BJI WILL SEE INCREASING CHANCES FOR TSTM...WITH CELLS ARRIVING BY MID MORNING AND CONTINUING THROUGH EARLY SUN MORNING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...SPEICHER SHORT TERM...SPEICHER LONG TERM...DK/SPEICHER AVIATION...SPEICHER
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
215 PM PDT SAT MAY 31 2014 .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL BRING MAINLY NIGHT TO MORNING LOW CLOUDS AND FOG FROM THE BEACHES TO THE VALLEYS FOR NEXT WEEK...WITH BREEZY WINDS AND FAIR SKIES IN THE MOUNTAINS AND DESERTS. THE TEMPERATURES WILL BE NEAR NORMAL FOR NEXT WEEK...WITH A SLIGHT WARMUP AT THE END OF THE WEEK. && .SHORT TERM (TODAY-TUESDAY)... A WEAK SUNDOWNER WIND EVENT REMAINS POSSIBLE THIS EVENING AS KSBA-KSMX SURFACE PRESSURE GRADIENTS ARE MARGINAL. MODELS ARE SLIGHTLY WEAKER WITH THE WINDS AND THERMAL SUPPORT...DESPITE PRESSURE GRADIENTS HOLDING NEAR YESTERDAYS LEVELS. 3-KM HRRR MODEL SOLUTIONS ARE ALSO A TAD WEAKER FOR THIS EVENING. LOCAL ADVISORY LEVEL GUSTS ARE POSSIBLE THIS EVENING...MAINLY WEST OF AND NEAR GAVIOTA. OTHERWISE...ONSHORE FLOW CONTINUES TO STRENGTHEN THIS AFTERNOON AS THE AXIS FROM A TROUGH OF LOW PRESSURE OVER CENTRAL CALIFORNIA SLIDES OVER THE AREA. HOWEVER...A WEAK SHORTWAVE RIDGE UPSTREAM IS STARTING TO PLAY INTO THE FORECAST THIS AFTERNOON. LATEST KLAX AMDAR SOUNDINGS SUGGEST THAT THE MARINE LAYER IS THINNING AS 1000-500 MB THICKNESS VALUES START TO RISE AS THE WEAK RIDGE AMPLIFIES ALONG THE CALIFORNIA COAST. THE FORECAST TAKES THIS INTO PLAY FOR SUNDAY BY REDUCING THE MARINE LAYER DEPTH AND COVERAGE SOMEWHAT AND INTRODUCING A SLIGHT WARM-UP FOR SUNDAY. THE SHORTWAVE RIDGE WILL MOVE EAST SUNDAY NIGHT AS A WEAK TROUGH OF LOW PRESSURE CENTERED ABOUT 1000 MILES TO SOUTHWEST OF LOS ANGELES MOVES NORTHEAST AND DEEPENS. THE MAIN EFFECTS OF THE TROUGH WILL BE A DEEPER MARINE LAYER AND STRONGER ONSHORE FLOW INTO TUESDAY. ADVISORY LEVEL WINDS ARE POSSIBLE OUT IN THE DESERT ON MONDAY AS THE STRONGER ONSHORE GRADIENTS DEVELOP AND COMBINE WITH THE UPPER-LEVEL SUPPORT AS THE TROUGH MOVES OVER THE REGION. MODELS CONTINUE TO TAKE A DRY STANCE WITH THE TROUGH...BUT A FEW CLOUDS OVER THE MOUNTAINS WOULD NOT BE SURPRISING FOR MONDAY AS 850 MB MIXING RATIO APPROACH 5 G/KG. .LONG TERM (WEDNESDAY-SATURDAY)... ANOTHER TROUGH QUICKLY DIPS SOUTH ON WEDNESDAY BEHIND THE EXITING TROUGH...REENFORCING ONSHORE FLOW AND ALLOWING FOR A CONTINUED DEEPER MARINE LAYER. A COOLING TREND LOOKS TO LINGER INTO WEDNESDAY...BUT 500 MB HEIGHTS AND 1000-500 MB THICKNESS VALUES CLIMB FOR LATE WEEK. A FLAT RIDGING PATTERN DEVELOPS FOR LATE WEEK AND SHOULD PROVIDE A WARMING TREND WITH A THINNING MARINE LAYER FOR LATE NEXT WEEK. A JUNE GLOOM PATTERN COULD SET-UP ALONG THE COAST WITH ANY MARINE LAYER CLOUDINESS LINGERING INTO THE AFTERNOON. OUTSIDE OF THE MARINE LAYER...THE AIR MASS SHOULD BE WARM. LOCAL STUDIES SUGGEST 100 PLUS DEGREE TEMEPRATURES IN THE ANTELOPE VALLEY FOR HIGH TEMPERATURES FOR LATE NEXT WEEK...WITH TEMPERATURES IN THE MID TO UPPER 90S FOR THE WARMER VALLEY LOCATIONS...SUCH AS WOODLAND HILLS...OJAI...AND SANTA CLARITA. WITH SOME UNCERTAINTY STILL IN PLAY...THE PACKAGE DOES NOT TAKE SUCH AN AGGRESSIVE STANCE AT THIS TIME. && .AVIATION...31/1800Z. MODERATE CONFIDENCE FOR TAFS N OF PT CONCEPTION. IFR MARINE LAYER CIGS EXPECTED TO RETURN BY 05Z BUT TIMING MAY DIFFER +/- 2 HRS FROM TAF TIMES. 30% CHANCE OF LIFR CONDS FOR CENTRAL COAST SITES OVERNIGHT...AND KPRB AFTER 12Z SUNDAY. LOW CONFIDENCE FOR COAST AND VALLEY SITES S OF PT CONCEPTION. 30% CHANCE TIMING OF MARINE LAYER CIGS WILL DIFFER 2 HRS OR MORE FROM TAF TIMES. AREAL COVERAGE IS LOW CERTAINTY AS LOW CLOUDS MAY NOT AFFECT THE VENTURA COAST...AND MAY MOVE INLAND TO THE L.A. VALLEY SITES. HIGH CONFIDENCE IN BREEZY CLEAR CONDITIONS FOR KPMD AND KWJF. KLAX...HIGH CONFIDENCE IN VFR CONDS BETWEEN 18Z AND 06Z TODAY...BUT LOWER CONFIDENCE AFTER 06Z...WITH TIMING OF LOW CLOUDS UNCERTAIN AND A 20% CHANCE LOW CIGS WILL NOT AFFECT THE SITE. KBUR...MODERATE CONFIDENCE IN TAF WITH A 20 PERCENT CHC OF IFR/LIFR CIGS 13Z-16Z SUNDAY MORNING. && .MARINE...31/200 PM. A STABLE PATTERN WILL BE IN PLACE OVER THE FORECAST PERIOD...WITH A SURFACE HIGH AROUND 1033 MB ABOUT 700 NM WEST OF THE OREGON COAST AND THERMAL LOW PRESSURE S OF LAS VEGAS. THIS WILL MAINTAIN MODERATE NW WINDS ACROSS THE OUTER WATERS...WITH LOCALLY MODERATE NW TO WEST WINDS PUSHING INTO THE WESTERN PORTION OF THE SANTA BARBARA CHANNEL. FOR THE OUTER WATERS...HIGH CONFIDENCE IN FORECAST OF SCA WINDS WITH GUSTS TO 30 KT THROUGH LATE TONIGHT. THERE IS A 20% CHANCE THAT LOCALIZED GUSTS TO 35 KT WILL OCCUR LATE THIS AFTERNOON INTO EARLY EVENING...ESPECIALLY IN THE AREA BETWEEN SANTA ROSA ISLAND AND PT CONCEPTION. FOR INNER WATERS...LOW END SCA WINDS WILL AFFECT PZZ645 THIS AFTERNOON THROUGH AROUND 9 PM...ALONG WITH SHORT PERIOD SEAS 5 TO 7 FT AT 8 SECONDS. GUSTY WINDS WILL ALSO AFFECT THE WESTERN SANTA BARBARA CHANNEL...WITH LOCAL GUSTS UP TO 25 KT IN THE EVENING. OTHERWISE MAINLY LIGHT WINDS ARE EXPECTED NEARSHORE. A WEAK CATALINA EDDY WILL DEVELOP TONIGHT...CAUSING SE WINDS 5 TO 10 KT BY EARLY SUNDAY MORNING OVER THE SAN PEDRO CHANNEL. SHORT PERIOD SEAS WILL RESULT IN ROUGH BOATING CONDITIONS FOR SMALL CRAFT ACROSS MUCH OF THE NEAR SHORE WATERS...WITH SEAS 3 TO 5 FEET AT 7 SECONDS ACROSS PZZ650/655. && .LOX WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY (SEE LAXMWWLOX). && $$ PUBLIC...HALL MARINE...SMITH AVIATION...SMITH SYNOPSIS...SETO/HALL WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
440 PM MDT SAT MAY 31 2014 .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 301 PM MDT SAT MAY 31 2014 MORE CONVECTION ACROSS THE NORTH THAN WHAT THE RAP AND WRF MODELS HAVE INDICATED QPF WISE. CONVECTION AND QPF IN THE NAM MODEL MAY BE A LITTLE OVERDONE BUT IS DEFINITELY MORE REPRESENTATIVE THAN THE DRIER HIGHER RESOLUTION MODELS. AIR MASS TRENDING TO A DRIER REGIME TODAY...BUT STILL SUFFICIENT MID LEVEL MOISTURE...GRADIENT FLOW...AND CONVECTIVE POTENTIAL FOR FOR SCATTERED STORMS ACROSS THE NRN HALF. A COUPLE OF STRONG CELLS HAVE FORMED IN MOFFAT COUNTY NEAR THE WYOMING BORDER. UPSTREAM TROUGH CENTERED OVER THE NRN INTERMOUNTAIN REGION TAKES A NEGATIVE TILT ORIENTATION THIS EVENING AS IT SWINGS ACROSS WRN COLORADO. THE NAM SHOWS EXPANDING AREAS OF QPF TONIGHT AS THIS WAVE MOVES ACROSS NE UTAH AND NW COLORADO. QG DIAGNOSTICS SHOW SOME DYNAMICAL FORCING FOR NW COLORADO THIS EVENING...ALTHOUGH THIS FORCING IS FRACTURED. SCATTERED NOCTURNAL SHOWERS AND STORMS EXPECTED...BUT THEY SHOULD BE MOVING FAIRLY QUICKLY AT AROUND 25-35 MPH FROM THE SW TO NE. ONCE THE WAVE MOVES DOWNSTREAM...WSW ADVECTS DRIER AND MORE STABLE AIR MASS INTO UTAH AND WRN COLORADO. CONVECTIVE POTENTIAL WILL BE NEARLY NON EXISTENT...MEANING DRY WEATHER WITH AFTERNOON BREEZES. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 301 PM MDT SAT MAY 31 2014 MODELS ARE CURRENTLY POINTING TOWARD A MOSTLY DRY WEEK WITH SEASONABLE TEMPERATURES...THOUGH CONFIDENCE LOWERS AFTER WEDNESDAY AS MODEL AGREEMENT LESSENS. AN UPPER HIGH OVER NORTHWEST OLD MEXICO SHOULD EFFECTIVELY BLOCK ANY NORTHWARD TRANSPORT OF SUBTROPICAL MOISTURE... LEAVING MOISTURE TRANSPORT TO A SERIES OF WEAK DISTURBANCES MOVING INLAND ACROSS WEST. A PACIFIC UPPER LOW LOCATED NEAR 130W/30N THIS AFTERNOON GETS PULLED INLAND ACROSS CA ON MONDAY...THEN TRACKS ACROSS NRN UT NWRN CO ON TUE. TIME-HEIGHT SECTIONS SHOW LITTLE IN THE WAY OF DEEP MOISTURE... SO WILL KEEP THE FORECAST DRY. BUT...ITS PASSAGE WILL LIKELY BRING SOME WINDIER CONDITIONS TUESDAY AFTERNOON WHICH MAY POSE SOME FIRE WEATHER CONCERNS. GFS AND ECMWF SHOW ANOTHER WAVE COMING ACROSS THE GREAT BASIN LATE IN THE WEEK BUT DIFFER ON SPEED AND ORGANIZATION. WILL KEEP JUST A SLIGHT CHANCE OF MTNS SHOWERS THU-SAT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 431 PM MDT SAT MAY 31 2014 SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH 06Z THIS EVENING NORTH OF A LINE FROM KCNY-KGJT-KMTJ-KGUC-KMYP. GUSTY WINDS OF 30-35 KTS AND LOCALIZED SMALL HAIL WILL BE THE PRIMARY AVIATION HAZARD. ISOLATED -TSRA WILL BE POSSIBLE OVER THE SAN JUAN MOUNTAINS. THESE SHOWERS AND STORMS WILL BE DIMINISHING AFTER 06Z AND FINISHED BY 12Z. DRY WEATHER WITH NO STORMS ARE EXPECTED ON SUNDAY. CONTINUED VFR AT ALL TAF SITES. && .HYDROLOGY... ISSUED AT 301 PM MDT SAT MAY 31 2014 SEASONABLE TEMPERATURES WILL CONTINUE TO MELT THE SNOWPACK ACROSS THE REGION WITH RIVER AND STREAM LEVELS FORECAST TO REMAIN HIGH. THE HIGHEST FLOWS WERE OCCURRING IN RIVERS AND STREAMS FROM THE GUNNISON BASIN IN WEST-CENTRAL COLORADO NORTHWARD TO THE WYOMING BORDER AND ACROSS NORTHEAST UTAH. VARIOUS FLOOD PRODUCTS REMAIN IN EFFECT FOR THESE CONDITIONS. PAY ATTENTION TO RIVER...CREEK AND STREAM LEVELS AND WATCH FOR DEBRIS BUILDUP. PLEASE USE CAUTION IF YOU PLAN ON BOATING DOWN OR RECREATING NEAR ANY RIVERS OR STREAMS THROUGH NEXT WEEK. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ SHORT TERM...PF LONG TERM...JAD AVIATION...JDC HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
301 PM MDT SAT MAY 31 2014 .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 301 PM MDT SAT MAY 31 2014 MORE CONVECTION ACROSS THE NORTH THAN WHAT THE RAP AND WRF MODELS HAVE INDICATED QPF WISE. CONVECTION AND QPF IN THE NAM MODEL MAY BE A LITTLE OVERDONE BUT IS DEFINITELY MORE REPRESENTATIVE THAN THE DRIER HIGHER RESOLUTION MODELS. AIR MASS TRENDING TO A DRIER REGIME TODAY...BUT STILL SUFFICIENT MID LEVEL MOISTURE...GRADIENT FLOW...AND CONVECTIVE POTENTIAL FOR FOR SCATTERED STORMS ACROSS THE NRN HALF. A COUPLE OF STRONG CELLS HAVE FORMED IN MOFFAT COUNTY NEAR THE WYOMING BORDER. UPSTREAM TROUGH CENTERED OVER THE NRN INTERMOUNTAIN REGION TAKES A NEGATIVE TILT ORIENTATION THIS EVENING AS IT SWINGS ACROSS WRN COLORADO. THE NAM SHOWS EXPANDING AREAS OF QPF TONIGHT AS THIS WAVE MOVES ACROSS NE UTAH AND NW COLORADO. QG DIAGNOSTICS SHOW SOME DYNAMICAL FORCING FOR NW COLORADO THIS EVENING...ALTHOUGH THIS FORCING IS FRACTURED. SCATTERED NOCTURNAL SHOWERS AND STORMS EXPECTED...BUT THEY SHOULD BE MOVING FAIRLY QUICKLY AT AROUND 25-35 MPH FROM THE SW TO NE. ONCE THE WAVE MOVES DOWNSTREAM...WSW ADVECTS DRIER AND MORE STABLE AIR MASS INTO UTAH AND WRN COLORADO. CONVECTIVE POTENTIAL WILL BE NEARLY NON EXISTENT...MEANING DRY WEATHER WITH AFTERNOON BREEZES. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 301 PM MDT SAT MAY 31 2014 MODELS ARE CURRENTLY POINTING TOWARD A MOSTLY DRY WEEK WITH SEASONABLE TEMPERATURES...THOUGH CONFIDENCE LOWERS AFTER WEDNESDAY AS MODEL AGREEMENT LESSENS. AN UPPER HIGH OVER NORTHWEST OLD MEXICO SHOULD EFFECTIVELY BLOCK ANY NORTHWARD TRANSPORT OF SUBTROPICAL MOISTURE... LEAVING MOISTURE TRANSPORT TO A SERIES OF WEAK DISTURBANCES MOVING INLAND ACROSS WEST. A PACIFIC UPPER LOW LOCATED NEAR 130W/30N THIS AFTERNOON GETS PULLED INLAND ACROSS CA ON MONDAY...THEN TRACKS ACROSS NRN UT NWRN CO ON TUE. TIME-HEIGHT SECTIONS SHOW LITTLE IN THE WAY OF DEEP MOISTURE... SO WILL KEEP THE FORECAST DRY. BUT...ITS PASSAGE WILL LIKELY BRING SOME WINDIER CONDITIONS TUESDAY AFTERNOON WHICH MAY POSE SOME FIRE WEATHER CONCERNS. GFS AND ECMWF SHOW ANOTHER WAVE COMING ACROSS THE GREAT BASIN LATE IN THE WEEK BUT DIFFER ON SPEED AND ORGANIZATION. WILL KEEP JUST A SLIGHT CHANCE OF MTNS SHOWERS THU-SAT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 301 PM MDT SAT MAY 31 2014 SCATTERED SHOWERS AND THUNDERSTORMS THROUGH 06Z EVENING NORTH OF A LINE OF KCNY- KGJT-KMTJ-KGUC-KMYP. GUSTY WINDS OF 30-35 KTS AND LOCALIZED SMALL HAIL WILL BE THE PRIMARY AVIATION HAZARD. ISOLATED -TSRA WILL BE POSSIBLE OVER THE SAN JUAN MOUNTAINS. THESE SHOWERS AND STORMS WILL BE DIMINISHING AFTER 06Z AND FINISHED BY 12Z. DRY WEATHER WITH NO STORMS ARE EXPECTED ON SUNDAY. CONTINUED VFR AT ALL TAF SITES. && .HYDROLOGY... ISSUED AT 301 PM MDT SAT MAY 31 2014 SEASONABLE TEMPERATURES WILL CONTINUE TO MELT THE SNOWPACK ACROSS THE REGION WITH RIVER AND STREAM LEVELS FORECAST TO REMAIN HIGH. THE HIGHEST FLOWS WERE OCCURRING IN RIVERS AND STREAMS FROM THE GUNNISON BASIN IN WEST-CENTRAL COLORADO NORTHWARD TO THE WYOMING BORDER AND ACROSS NORTHEAST UTAH. VARIOUS FLOOD PRODUCTS REMAIN IN EFFECT FOR THESE CONDITIONS. PAY ATTENTION TO RIVER...CREEK AND STREAM LEVELS AND WATCH FOR DEBRIS BUILDUP. PLEASE USE CAUTION IF YOU PLAN ON BOATING DOWN OR RECREATING NEAR ANY RIVERS OR STREAMS THROUGH NEXT WEEK. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ SHORT TERM...PF LONG TERM...JAD AVIATION...PF HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
325 PM EDT SAT MAY 31 2014 .SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A COMPLEX UPPER LEVEL PATTERN OVER THE CONUS CONSISTING OF AN AMPLIFIED NORTHERN STREAM FLOW OVER TOP A STUBBORN CUT OFF LOW SPINNING OVER THE SOUTHERN MS VALLEY. NORTHERN STREAM FLOW RIDGES WAY TO THE NORTH INTO CENTRAL/EASTERN CANADA BEFORE SHARPLY DIVING SOUTH INTO A DEVELOPING CLOSED LOW OFF THE NEW ENGLAND COAST. THE UPPER LOW OVER THE NORTHERN GULF COAST IS ON A SLOW SOUTHWARD PATH THAT WILL TAKE IT TO THE SOUTHERN GULF BY THE END OF THE WEEKEND. PLENTY OF CONVECTION ONCE AGAIN OVER THE CENTRAL GULF TODAY ASSOCIATED WITH THE CYCLONIC CIRCULATION...HOWEVER THIS MORE ORGANIZED CONVECTION WILL REMAIN WELL OFF THE FLORIDA WEST COAST...WITH LITTLE IMPACT ON OUR WEATHER OTHER THAN SOME "BLOW-OFF" CIRRUS INVADING OUR SKIES. THE MORNING 12Z KTBW SOUNDING SHOWS WE HAVE A MOIST PROFILE THROUGH THE EXTENT OF THE TROP WITH A MEASURED PW VALUES AROUND 1.75". STEERING LEVEL FLOW THROUGH 400MB IS VERY LIGHT (VECTOR AVERAGE IS JUST A SLIGHT PUSH FROM EAST TO WEST)...AND GUIDANCE KEEPS THIS FLOW ABOVE THE SURFACE LIGHT THROUGH THE EVENING HOURS. STORM MOTION VECTORS ARE MAYBE 5-10KNOTS FROM EAST TO WEST...SO WILL BE LOOKING FOR SOME SLOW MOVING CELLS INTO THE EVENING. OVERALL CAPE WITH THE MOIST SOUNDING WILL NOT BE ALL THAT HIGH (AT LEAST NOT TOO FAT A PROFILE THROUGH ANY ONE LEVEL)...HOWEVER THE HIGH PW VALUE WILL FAVOR EFFICIENT WATER LOADING OF THE STRONG CELLS WHICH WILL KEEP THE THREAT FOR LOCALLY DAMAGING WIND GUSTS IN THE FORECAST FOR YET ANOTHER DAY. AT THE SURFACE...THE REGION IS EXPERIENCING A WEAK EASTERLY TO SOUTHEASTERLY FLOW PATTERN BETWEEN A STRONG RIDGE OF HIGH PRESSURE BEGINNING TO BUILD DOWN THROUGH THE OHIO VALLEY/MID-ATLANTIC STATES...AND A WEAK SURFACE TROUGH IN PLACE OVER THE WESTERN GULF OF MEXICO. AS THIS RIDGE TO OUR NORTH BUILDS DOWN THE EASTERN SEABOARD THROUGH THE WEEKEND...THE LOCAL GRADIENT WILL BEGIN TO TIGHTEN AND RESULT IN SOME BREEZIER CONDITIONS BY SUNDAY AFTERNOON AND INTO THE EARLY PORTION OF NEXT WEEK. THIS STRONGER EASTERLY FLOW WILL CHANGE THE STRUCTURE AND PATTERN OF AFTERNOON STORMS THAT WE HAVE BECOME ACCUSTOMED TO OVER THE PAST SEVERAL DAYS. && .SHORT TERM (REST OF TODAY THROUGH SUNDAY)... THE LIGHT EASTERLY FLOW WILL FAVOR A QUICK INLAND PENETRATION OF THE EAST COAST SEA-BREEZE. SCATTERED/NUMEROUS SHOWERS/STORMS HAVE ALREADY DEVELOPED UP THE SPINE OF THE PENINSULA...AND WILL SLOWLY EVOLVE/TRANSLATE TO THE WEST AND NORTHWEST THROUGH THE LATER AFTERNOON/EARLY EVENING HOURS. THE COLUMN SEEMS PRIMED FOR STORM COVERAGE TO AGAIN BE NUMEROUS IN NATURE ALONG THE I-75 CORRIDOR... AND THINK STORMS WILL HAVE AN EASIER TIME MOVING WEST TO THE COAST TODAY (ALTHOUGH IT WILL BE SLOW). AS MENTIONED ABOVE...WATER LOADING OF THE STRONG CELLS WILL STILL PROVIDE A LOCALIZED WIND THREAT...ESPECIALLY ALONG AND INSIDE THE I-75 CORRIDOR (AFTER 4PM) WHERE LOW LEVEL CONVERGENCE/FOCUS FOR THE BEST UPDRAFTS WILL BE MAXIMIZED ALONG THE SEA-BREEZE...AND RESIDUAL OUTFLOW BOUNDARIES. LOCALLY RUN WRFARW GUIDANCE RUNS CONTINUE TO BE FAIRLY AGGRESSIVE WITH THE CONVECTIVE COVERAGE...AND FEEL CONFIDENT WITH THE CURRENT 60-70% POPS IN THE GRIDS ALONG THE FAVORED ZONE MENTIONED ABOVE. LEFTOVER STORMS WILL DIMINISH AND MOVE OFFSHORE WITH THE LOSS OF DIURNAL HEATING LATER THIS EVENING...ALLOWING THE TYPICAL WARM SEASON CALM PERIOD FOR MUCH OF THE OVERNIGHT. SEASONAL TEMPERATURES ARE EXPECTED WITH MANY SPOTS SEEING UPPER 60S TO LOWER 70S BY SUNRISE. SUNDAY... THE FINAL DAY OF THE WEEKEND WILL BE A TRANSITION DAY AS STRONG HIGH PRESSURE BUILDS DOWN THE EASTERN SEABOARD AND TIGHTENS THE LOCAL GRADIENT. A WEAK ILL-DEFINED SURFACE FRONTAL BOUNDARY WILL LEAD THIS RIDGE ADVANCE INTO THE PENINSULA DURING SUNDAY...HOWEVER THE FRONT IS MUCH MORE DEFINED ALOFT IN TERMS OF DRIER AIR...CAA. AS THE GRADIENT TIGHTENS...SPEED CONVERGENCE ALONG THE FLORIDA EAST COAST ADDED TO THE DIURNAL INSTABILITY SHOULD BE EFFICIENT AS DEVELOPING SHALLOW SHOWERS ALONG THE I-95 CORRIDOR THAT WILL THEN QUICKLY TRANSLATE WESTWARD ACROSS THE PENINSULA. THE STRONGER EAST FLOW WILL RESULT IN A MINIMUM OF CONVERGENCE ALONG THE EAST COAST SEA-BREEZE AS IT MOVES INLAND AND THEREFORE...WHILE EXPECTING NUMEROUS SHOWERS TO ADVANCE INTO HIGHLANDS/POLK/SUMTER COUNTIES...THE UPDRAFTS SHOULD NOT BE OVERLY IMPRESSIVE AND FEEL THE THREAT FOR STRONGER CELLS INLAND IS LOW. EASTERLY FLOW JUST ABOVE THE SURFACE IS FORECAST TO REACH 15-20 BY LATER SUNDAY AFTERNOON ACROSS THE REGION. THIS IS PLENTY OF MOMENTUM TO PIN ANY SEABREEZE AT THE COAST OR EVEN PREVENT A DEFINED SEA-BREEZE FROM EVEN BECOMING ESTABLISHED. WHAT WE ARE MORE LIKELY TO SEE IS A LOCAL SLOWING OF THE WINDS OVER THE NEARSHORE WATERS AS THE SEA-BREEZE UNSUCCESSFULLY ATTEMPTS TO DEVELOP. THIS SLOWING WHILE NOT AS EFFICIENT AT FOCUS AS AN ACTUAL BOUNDARY...WILL STILL PROVIDE SOME SPEED CONVERGENCE TO ASSIST IN UPDRAFT FORMATION. WITH THIS IN MIND FEEL THE BEST LATER DAY COVERAGE OF SHOWERS/STORMS... AND THE BEST CHANCE AT A FEW STRONGER STORMS WILL BE INSIDE/WEST OF THE I-75 CORRIDOR. KEEP THIS IN MIND IF HEADING TO THE BEACHES DURING THE SECOND HALF OF SUNDAY AFTERNOON. LOOKING FOR SEASONABLE TEMPERATURES SUNDAY AFTERNOON. WARMEST TEMPS (UPPER 80S/LOWER 90S) WILL BE ALONG AND INLAND THE I-75 CORRIDOR WHEN THE LEAST MARINE INFLUENCE AND LATEST CONVECTIVE ARRIVAL ARE EXPECTED. WELL INLAND THE EARLIER ARRIVAL OF SHOWERS AND CLOUDS SHOULD HOLD MOST PLACES UNDER THE 90 DEGREE MARK. && .MID TERM (SUNDAY NIGHT AND MONDAY) HIGH PRESSURE OVER NEW ENGLAND AND THE MID ATLANTIC STATES WILL SHIFT STEADILY SOUTHWARD TO A LOCATION OFF THE CAROLINA COASTLINE BY MONDAY EVENING. THIS WILL PROPEL A SURFACE FRONTAL BOUNDARY SOUTHWARD INTO NORTH FLORIDA ON SUNDAY WITH THE BOUNDARY CONTINUING TO SLIDE SOUTHWARD INTO SOUTH FLORIDA BY MONDAY EVENING. AS THE FRONTAL BOUNDARY SLIPS FURTHER SOUTHWARD ON MONDAY...COLUMN MOISTURE WILL BEGIN TO DECREASE ACROSS NORTHERN AREAS. AS A RESULT...WILL SHOW POPS RANGING FROM 20 PERCENT ACROSS THE NATURE COAST TO 50/60 PERCENT ACROSS SOUTHWEST FLORIDA MONDAY AFTERNOON. HIGH TEMPERATURES ARE EXPECTED TO TOP OUT IN THE UPPER 80S TO AROUND 90 DEGREES. LOWS SUNDAY NIGHT ARE EXPECTED TO BOTTOM OUT IN THE UPPER 60S TO LOWER 70S. && .LONG TERM (MONDAY NIGHT THROUGH SATURDAY)... MEDIUM RANGE GUIDANCE IS OFFERING UP VARYING SOLUTIONS THROUGH THE LONG TERM PERIODS...LEADING TO LOWER THAN NORMAL FORECAST CONFIDENCE. THE 00Z ECMWF AND 00Z CANADIAN BOTH SHOW STRONGER DEEP LAYER RIDGING BUILDING INTO THE AREA THROUGH THE MIDDLE TO LATTER PORTION OF THE UPCOMING WORK WEEK...AND AS A RESULT THEY KEEP THE DEEPEST MOISTURE SOUTH OF THE PENINSULA AND OUT OVER THE GULF OF MEXICO. THE 00Z GFS ON THE OTHER HAND SHOWS WEAKER DEEP LAYER RIDGING BUILDING INTO THE AREA...ALLOWING THE FRONTAL BOUNDARY AND DEEPER COLUMN MOISTURE TO HANG UP OVER SOUTH FLORIDA THROUGH THE WEEK. GIVEN THE LACK OF STRONG CONSENSUS AMONGST THE OPERATIONAL MODELS...WILL KEEP RAIN CHANCES IN THE FORECAST FOR MAINLY AFTERNOON/EARLY EVENING SHOWERS AND THUNDERSTORMS...WITH HIGHEST POPS ACROSS SOUTHERN ZONES. && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THE REST OF THE DAY AND EVENING AWAY FROM SCT-NMRS SHOWERS/STORMS WHICH ARE PROGRESS SLOWLY WESTWARD ACROSS THE PENINSULA. PROBABILITIES ARE HIGH FOR MOST OF THE TERMINALS TO SEE A BRIEF RESTRICTION ASSOCIATED WITH A PASSING STORM...BUT THE DURATION SHOULD BE SHORT. STORMS WILL DIMINISH AND MOVE OFFSHORE AFTER MID EVENING WITH GENERAL VFR AND DRY CONDITIONS RETURNING TO ALL THE TERMINALS OVERNIGHT. && .MARINE... EASTERLY WINDS WILL PREVAIL ACROSS THE WATERS THROUGH MID WEEK AS HIGH PRESSURE OVER THE NEW ENGLAND STATES SHIFTS SOUTHEASTWARD TOWARD THE CAROLINA COAST THE NEXT COUPLE OF DAYS. A TIGHTENING GRADIENT WILL RESULT IN STRONGER EASTERLY FLOW DEVELOPING BY SUNDAY AFTERNOON AND CONTINUING INTO THE EARLY PORTION OF NEXT WEEK. THE WINDS WILL BE STRONGEST OVERNIGHT INTO THE EARLY MORNING HOURS WHEN PERIODS OF CAUTIONARY LEVEL FLOW ARE EXPECTED. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES WILL REMAIN ABOVE CRITICAL LEVELS THROUGH THE NEXT SEVERAL DAYS AND NO RED FLAG CONDITIONS ARE EXPECTED. INCREASE TRANSPORT WINDS FROM THE EAST ON SUNDAY WILL RESULT IN LOCALLY HIGH DISPERSION INDICES...ESPECIALLY NEAR THE COAST AS SURFACE WINDS WEAKEN IN THE AFTERNOON. FOG POTENTIAL...NO SIGNIFICANT FOG IS EXPECTED THROUGH THE NEXT SEVERAL DAYS. && .PRELIMINARY POINT TEMPS/POPS... TPA 73 90 73 88 / 30 60 20 30 FMY 72 90 73 89 / 20 60 20 50 GIF 71 88 71 87 / 20 60 10 30 SRQ 72 90 73 89 / 40 60 30 40 BKV 69 91 70 87 / 30 60 10 30 SPG 75 88 75 87 / 40 60 30 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA MID TERM/LONG TERM...21/JELSEMA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
233 PM EDT Sat May 31 2014 .Near Term [Through Tonight... Thunderstorms have developed initially early this afternoon very near where recent runs of the 3km HRRR and the 09Z run of our local WRF-ARW expected - around the lower Apalachicola River and Gulf County in the Florida Panhandle. As these models were the basis of the updated forecast this morning, the forecast seems to be on track for the next 6-12 hours. Additional thunderstorms are developing along the Atlantic sea breeze in northeast Florida and southeast Georgia, and should advance into eastern parts of our area later this afternoon. Thunderstorms could linger into the evening hours - particularly in southwest Georgia and the Florida Big Bend. PoPs were kept higher in these eastern areas, with scattered thunderstorms expected elsewhere. An isolated strong to severe storm is not out of the question, especially near boundary collisions where enhanced low-level convergence would be expected. .Short Term [Sunday Through Monday Night]... The large scale amplified blocking pattern of recent days begins to break down into a more progressive pattern thru the short term. The CWA will be between upper low over Wrn Gulf of Mex and upper high over SE Conus. However this low has gradually but steadily filled in last 12 hrs as both systems continue to drop south and weaken with low progressively replaced by a weak upper ridge extending Ewd from Srn Plains to across the deep south by Mon night. Sunday...at surface, building high along mid-Atlc coast with ridging Swwd across NE Gulf region yielding increasing ESE flow sfc-H5 and PWATs approaching 2 inches. Ahead of ridge, weak backdoor front will be nudged SWWD into SE GA in the late morning and dropping into the Big Bend in the aftn. Lacking upper forcing, mesoscale processes, including the front, the sea breeze, and outflow clashes will provide the primary forcing for convection and PoP distribution, typical of summertime. The east coast sea breeze will once again concentrate evening convection primarily across our SW GA zones. Look for fairly evenly scattered convection with 60% PoPs daytime, 50-20% SW-NE evening POPs, highest near front. Inland high temps in upper 80s, except mid 80s NE tier GA counties due to clouds assocd with above boundaries. Monday...as surface high builds further down the Ern seaboard to Carolina coast by sundown, our 1000-700 mb winds back and increase to moderate ELY over east half but remain light ESE over west half. In addition, with backdoor front now south of CWA and ridge strengthening, drier air will build in from the ENE pushing PWATs below 1.3 inches Ern most counties by sunset (still around 1.7 inches Wrn counties). This should reduce convective coverage, particularly across our eastern zones. 50-20% daytime and 30-0% eve SW-NE POP gradients. Temperatures will be close to seasonal norms. Inland highs in mid 80s, low mid 60s east to upper 60s west. .Long Term [Tuesday Through Saturday]... The Wrn Gulf upper low will slide off the SW as the upper level ridge moves east toward the Carolinas and upstream ridge begins to build Newd into the Gulf region and deep south later on Tues thru Wed. At surface, ridge across the SE region remains largely intact. The upper ridge will gradually breakdown beginning on Thurs. So lacking upper forcing especially thru Wed, expect a generally summertime rainfall pattern of SE low level flow and wdly sct to scattered convection determined largely by aftn/eve seabreeze and outflow clashes rest of workweek. Looking longer term, a weak surface low still appears to form across Bay of Campeche or Nrn Yucatan Peninsula around Wed bears watching as moisture heads towards our area beginning on Sat. Will go with mainly aftn/eve 30-20% W-E POPs on Tues, 20-30% S-N Fri and 30-40% Sat. Otherwise NIL POPS. Temperatures will be near Climo with highs in the upper 80s and low 90s and lows in the upper 60s. && .Aviation... [Through 18Z Sunday] An initial area of thunderstorm development should affect ECP between 19-21Z. IFR VIS will be possible along with some gusty winds. Elsewhere, scattered thunderstorms are expected. This was mostly handled in the other terminal forecasts with a longer period of prevailing SHRA with VCTS, as timing and location of thunderstorms is still a bit uncertain. VFR should generally prevail outside of thunderstorms. && .Marine... Winds will generally be out of the east-southeast over the next several days, veering to more directly onshore near the coast each afternoon in the sea breeze. A ridge of high pressure will build down the eastern seaboard and the gradient will become tight enough for an easterly surge event Sunday night into Monday, which is now expected to bring cautionary level winds and seas and borderline advisory level winds Sunday overnight well offshore. As the ridge settles further south, the gradient will weaken allowing winds and seas to subside for the early part of the work week. && .Fire Weather... Hazardous fire weather conditions are not expected over the next several days. && .Hydrology... With a summertime pattern well established across the region, large scale flooding is not anticipated. As on most summer days, isolated areas of heavy rain will be possible in some thunderstorms. These may briefly produce flooding in poor drainage areas and could cause sharp rises on the faster responding small creeks and streams. Main stem rivers are expected to remain in their banks. && .Preliminary Point Temps/PoPs... Tallahassee 69 87 68 86 68 / 40 60 50 30 20 Panama City 72 86 72 84 72 / 20 50 40 40 20 Dothan 69 87 67 86 68 / 40 60 40 30 20 Albany 69 86 66 86 66 / 60 60 30 20 10 Valdosta 68 86 65 87 66 / 50 60 40 20 10 Cross City 68 87 67 86 66 / 40 60 30 20 10 Apalachicola 72 85 73 84 73 / 20 50 40 30 20 && .TAE Watches/Warnings/Advisories... FL...High Rip Current Risk until Midnight CDT tonight for Coastal Bay- South Walton. GA...None. AL...None. GM...None. && $$ NEAR TERM...LAMERS SHORT TERM...BLOCK LONG TERM...WESTON AVIATION...LAMERS MARINE...BLOCK FIRE WEATHER...LAMERS HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS WICHITA KS
550 PM CDT SAT MAY 31 2014 ...UPDATED FOR 00Z AVIATION DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 257 PM CDT SAT MAY 31 2014 VISIBLE AND WATER VAPOR SATELLITE IMAGERY DETECTING SUBSTANTIAL LOW AND MID-LEVEL MOISTURE ACROSS THE AREA...ASSOCIATED SUB-TROPICAL MOISTURE PLUME AND BROAD SCALE ISENTROPIC LIFT. WEAK CONVECTION BEGINNING TO BUBBLE IN VICINITY OF OLD...CLOSED LOW THAT IS MEANDERING OVER ARKANSAS. ALSO SEEING WEAK CONVECTION FORMING ALONG NUMEROUS LOW LEVEL BOUNDARIES LEFT OVER FROM YESTERDAYS AND OVERNIGHT CONVECTION. OVERALL LARGE SCALE DYNAMIC AND KINEMATIC FORCING REMAINS WEAK ACROSS EASTERN PART OF CWA...THUS CONVECTION THAT FORMS ALONG AND EAST OF KANSAS TURNPIKE WILL BE DIURNALLY DRIVEN AND SUB-SEVERE. TONIGHT: SOME CONCERN ABOUT CONVECTION FORMING ALONG BOUNDARIES LEFT OVER FROM OVERNIGHT CONVECTION...THAT CURRENTLY ARE LOCATED NORTH AND WEST OF CWA. APPROACHING UPPER LEVEL WAVE WILL INCREASE KINEMATIC FORCING THIS EVENING. QUICK PEEK AT NSSL WRF ENSEMBLE/SSEF HINTING AT A SMALL QUASI-LINEAR DEVELOPING ACROSS KANSAS HIGH PLAINS AND MOVING INTO CENTRAL KANSAS BY MID-EVENING. SOME REFLECTION OF THIS SCENARIO BEING INDICATED BY HRRR AS WELL...ENOUGH TO WARRANT AT LEAST A SLIGHT CHANCE ACROSS CENTRAL KANSAS. REGARDLESS ALL THESE MESO MODELS WEAKEN ACTIVITY BY LATE EVENING...AS FLOW STARTS BACKING AS STRONGER UPSTREAM WAVE APPROACHES FOR SUNDAY. SUNDAY: FORECAST MODELS CONTINUE TO AGREE ON A MORE POTENT SHORTWAVE MOVING ACROSS NORTHERN PLAINS SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...WITH ATTENDANT COLD FRONT STRETCHING ACROSS NEBRASKA/KANSAS HIGH PLAINS...WITH DRYLINE EXTENDING FROM SOUTHERN KANSAS INTO PANHANDLE. INITIAL STORM DEVELOP LIKELY WILL BE WEST OF CWA WHERE CONVERGENCE IS MAXIMIZED...BUT DIABATIC HEATING ALONG DRYLINE WILL RAMP UP INSTABILITY BY MID-AFTERNOON. WITH VERTICAL WIND PROFILES INCREASING THROUGH THE DAY...CONFIDENT SEVERE CONVECTION WILL BE EXPLODING WEST OF THE CWA. SOME UNCERTAINTY EXISTS AS TO HOW FAR EAST AND SOUTH DRYLINE CONVECTION WILL MAKE IT GIVEN WARM MID-LEVEL TEMPERATURES. BETTER CONFIDENCE THAT CONVECTION THAT FORMS ALONG COLD FRONT ACROSS NEBRASKA AND FAR NORTHERN KANSAS WILL CONGEAL INTO MCS...AND TRACK ALONG THE PERIPHERY OF MID-LEVEL 310-315 THETA GRADIENT...GENERALLY ALONG I-70 AND EASTERN US 50 CORRIDORS. SEVERE STORMS WILL BE POSSIBLE WITH AROUND 1500-2500J/KG OF ELEVATED CAPE AND 35-50KTS OF DEEP LAYER SHEAR. MONDAY: LINGERING CONVECTION DEBRIS WILL IMPACT MAINLY EASTERN PART OF CWA DURING THE MORNING. LINGERING SYNOPTIC BOUNDARY AND LEFT OVER MESO BOUNDARIES WILL AID IN REDEVELOPMENT DURING THE AFTERNOON HOURS...AGAIN MAINLY EAST WHERE DIURNAL HEATING WILL INCREASE LOW/MID LEVEL INSTABILITIES INTO THE 2000-4000 J/KG RANGE WITH BULK SHEAR PROFILES AGAIN IN THE 35-50KT RANGE. MID-LEVEL CAPPING AGAIN MAY BE A DETERRENT TO CONVECTION DEVELOPING. TUESDAY: FRONTAL BOUNDARY LIFTS NORTH MONDAY NIGHT INTO TUESDAY...SO CURRENT THINKING IS WEATHER WILL BE RATHER QUIET ON TUESDAY EXCEPT FOR SOME DIURNAL CONVECTION. FORECAST MODELS AGAIN INDICATING THAT ANOTHER MCS COULD FORM WESTERN NEBRASKA/EASTERN WYOMING AND MOVE EAST DURING THE OVERNIGHT HOURS. TRACK APPEARS FURTHER NORTH...SO MAY JUST BRUSH CWA. SF .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 257 PM CDT SAT MAY 31 2014 QUASI-ZONAL FLOW WILL REMAIN IN PLACE ACROSS THE CENTRAL PLAINS. SEVERAL REINFORCING SHORT WAVES APPEAR TO SUPPRESS SOUTHERN U.S. RIDGE WITH TIME...THUS AREA LIKELY WILL EXPERIENCE SEVERAL ROUNDS OF CONVECTION. GEFS DEPICTING SOME UNCERTAINTY WITH TIMING AND INTENSITY OF EACH SUCCESSIVE SHORT WAVE...SO TIMING CONFIDENCE IS LOW. TEMPERATURES WILL REMAIN SEASONABLE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 545 PM CDT SAT MAY 31 2014 WIDELY SCATTERED DIURNAL SHOWERS AND ISOLATED THUNDERSTORMS MAY IMPACT KCNU THROUGH 01-02Z BEFORE DIMINISHING. AS WINDS BECOME LIGHT AND SOUTHEAST LATE TONIGHT/EARLY SUNDAY AREAS OF MVFR CIGS/VISIBILITIES MAY DEVELOP ACROSS PORTIONS OF SOUTH CENTRAL AND SOUTHEAST KANSAS...ESPECIALLY IN AREAS THAT RECEIVED RAINFALL. REDUCED VISIBILITIES AND CIGS ARE EXPECTED TO BE SHORT-LIVED CENTERED AROUND 12Z BEFORE MIXING OUT. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BECOME MORE NUMEROUS ACROSS CENTRAL KANSAS AFTER 22Z ON SUNDAY WHILE SPREADING EASTWARD ACROSS THE AREA SUNDAY NIGHT. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 67 88 70 89 / 10 10 40 20 HUTCHINSON 66 89 69 89 / 20 10 50 20 NEWTON 66 87 68 88 / 10 10 50 20 ELDORADO 66 85 68 86 / 10 10 50 20 WINFIELD-KWLD 67 87 70 88 / 10 10 40 20 RUSSELL 67 91 67 88 / 20 40 70 10 GREAT BEND 66 91 67 89 / 20 40 70 10 SALINA 67 91 69 89 / 20 20 70 20 MCPHERSON 67 89 69 89 / 20 20 50 20 COFFEYVILLE 67 85 71 85 / 20 10 40 30 CHANUTE 67 85 70 84 / 20 10 50 40 IOLA 67 85 70 84 / 20 10 50 40 PARSONS-KPPF 67 85 71 85 / 20 10 40 40 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
339 PM CDT SAT MAY 31 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 257 PM CDT SAT MAY 31 2014 VISIBLE AND WATER VAPOR SATELLITE IMAGERY DETECTING SUBSTANTIAL LOW AND MID-LEVEL MOISTURE ACROSS THE AREA...ASSOCIATED SUB-TROPICAL MOISTURE PLUME AND BROAD SCALE ISENTROPIC LIFT. WEAK CONVECTION BEGINNING TO BUBBLE IN VICINITY OF OLD...CLOSED LOW THAT IS MEANDERING OVER ARKANSAS. ALSO SEEING WEAK CONVECTION FORMING ALONG NUMEROUS LOW LEVEL BOUNDARIES LEFT OVER FROM YESTERDAYS AND OVERNIGHT CONVECTION. OVERALL LARGE SCALE DYNAMIC AND KINEMATIC FORCING REMAINS WEAK ACROSS EASTERN PART OF CWA...THUS CONVECTION THAT FORMS ALONG AND EAST OF KANSAS TURNPIKE WILL BE DIURNALLY DRIVEN AND SUB-SEVERE. TONIGHT: SOME CONCERN ABOUT CONVECTION FORMING ALONG BOUNDARIES LEFT OVER FROM OVERNIGHT CONVECTION...THAT CURRENTLY ARE LOCATED NORTH AND WEST OF CWA. APPROACHING UPPER LEVEL WAVE WILL INCREASE KINEMATIC FORCING THIS EVENING. QUICK PEEK AT NSSL WRF ENSEMBLE/SSEF HINTING AT A SMALL QUASI-LINEAR DEVELOPING ACROSS KANSAS HIGH PLAINS AND MOVING INTO CENTRAL KANSAS BY MID-EVENING. SOME REFLECTION OF THIS SCENARIO BEING INDICATED BY HRRR AS WELL...ENOUGH TO WARRANT AT LEAST A SLIGHT CHANCE ACROSS CENTRAL KANSAS. REGARDLESS ALL THESE MESO MODELS WEAKEN ACTIVITY BY LATE EVENING...AS FLOW STARTS BACKING AS STRONGER UPSTREAM WAVE APPROACHES FOR SUNDAY. SUNDAY: FORECAST MODELS CONTINUE TO AGREE ON A MORE POTENT SHORTWAVE MOVING ACROSS NORTHERN PLAINS SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...WITH ATTENDANT COLD FRONT STRETCHING ACROSS NEBRASKA/KANSAS HIGH PLAINS...WITH DRYLINE EXTENDING FROM SOUTHERN KANSAS INTO PANHANDLE. INITIAL STORM DEVELOP LIKELY WILL BE WEST OF CWA WHERE CONVERGENCE IS MAXIMIZED...BUT DIABATIC HEATING ALONG DRYLINE WILL RAMP UP INSTABILITY BY MID-AFTERNOON. WITH VERTICAL WIND PROFILES INCREASING THROUGH THE DAY...CONFIDENT SEVERE CONVECTION WILL BE EXPLODING WEST OF THE CWA. SOME UNCERTAINTY EXISTS AS TO HOW FAR EAST AND SOUTH DRYLINE CONVECTION WILL MAKE IT GIVEN WARM MID-LEVEL TEMPERATURES. BETTER CONFIDENCE THAT CONVECTION THAT FORMS ALONG COLD FRONT ACROSS NEBRASKA AND FAR NORTHERN KANSAS WILL CONGEAL INTO MCS...AND TRACK ALONG THE PERIPHERY OF MID-LEVEL 310-315 THETA GRADIENT...GENERALLY ALONG I-70 AND EASTERN US 50 CORRIDORS. SEVERE STORMS WILL BE POSSIBLE WITH AROUND 1500-2500J/KG OF ELEVATED CAPE AND 35-50KTS OF DEEP LAYER SHEAR. MONDAY: LINGERING CONVECTION DEBRIS WILL IMPACT MAINLY EASTERN PART OF CWA DURING THE MORNING. LINGERING SYNOPTIC BOUNDARY AND LEFT OVER MESO BOUNDARIES WILL AID IN REDEVELOPMENT DURING THE AFTERNOON HOURS...AGAIN MAINLY EAST WHERE DIURNAL HEATING WILL INCREASE LOW/MID LEVEL INSTABILITIES INTO THE 2000-4000 J/KG RANGE WITH BULK SHEAR PROFILES AGAIN IN THE 35-50KT RANGE. MID-LEVEL CAPPING AGAIN MAY BE A DETERRENT TO CONVECTION DEVELOPING. TUESDAY: FRONTAL BOUNDARY LIFTS NORTH MONDAY NIGHT INTO TUESDAY...SO CURRENT THINKING IS WEATHER WILL BE RATHER QUIET ON TUESDAY EXCEPT FOR SOME DIURNAL CONVECTION. FORECAST MODELS AGAIN INDICATING THAT ANOTHER MCS COULD FORM WESTERN NEBRASKA/EASTERN WYOMING AND MOVE EAST DURING THE OVERNIGHT HOURS. TRACK APPEARS FURTHER NORTH...SO MAY JUST BRUSH CWA. SF .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 257 PM CDT SAT MAY 31 2014 QUASI-ZONAL FLOW WILL REMAIN IN PLACE ACROSS THE CENTRAL PLAINS. SEVERAL REINFORCING SHORT WAVES APPEAR TO SUPPRESS SOUTHERN U.S. RIDGE WITH TIME...THUS AREA LIKELY WILL EXPERIENCE SEVERAL ROUNDS OF CONVECTION. GEFS DEPICTING SOME UNCERTAINTY WITH TIMING AND INTENSITY OF EACH SUCCESSIVE SHORT WAVE...SO TIMING CONFIDENCE IS LOW. TEMPERATURES WILL REMAIN SEASONABLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1238 PM CDT SAT MAY 31 2014 CONVECTIVE POTENTIAL THIS AFTERNOON/MVRF TO IFR LOW CLOUDS AND FOG TOMORROW MORNING ARE MAIN ISSUES. CONVECTION THIS AFTERNOON WILL BE DIURNALLY DRIVEN PER LAST SEVERAL DAYS AT KCNU...WHILE A WEAK VORTICITY MAXIMUM MAY RESULT IN ISOLATED CONVERAGE IN CENTRAL KS. CHANCES AT KRSL SHOULD WANE RAPIDLY AROUND 2300 UTC AS AXIS OF WAVE PASSES. MODELS HAVE BEEN OVERLY AGRESSIVE WITH LOW LEVEL SATURATION DURING THE NIGHT...SO PLAYED LOW CLOUDS A BIT MORE CONSERVATIVE. APPEARS THAT MVFR WOULD BE LIKELY AROUND DAYBREAK...WITH IFR POSSIBLE...SLIGHTLY MORE LIKELY ACROSS SOUTH CENTRAL/SOUTHEAST KS. WITH INCREASE IN SURFACE PRESSURE GRADIENT AROUND DAYBREAK...SHOULD SEE QUICKER MIXING AND GUSTY WINDS BY MID MORNING AT MOST SITES. -HOWERTON && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 67 88 70 89 / 10 10 40 20 HUTCHINSON 66 89 69 89 / 20 10 50 20 NEWTON 66 87 68 88 / 10 10 50 20 ELDORADO 66 85 68 86 / 10 10 50 20 WINFIELD-KWLD 67 87 70 88 / 10 10 40 20 RUSSELL 67 91 67 88 / 20 40 70 10 GREAT BEND 66 91 67 89 / 20 40 70 10 SALINA 67 91 69 89 / 20 20 70 20 MCPHERSON 67 89 69 89 / 20 20 50 20 COFFEYVILLE 67 85 71 85 / 20 10 40 30 CHANUTE 67 85 70 84 / 20 10 50 40 IOLA 67 85 70 84 / 20 10 50 40 PARSONS-KPPF 67 85 71 85 / 20 10 40 40 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1156 AM MDT SAT MAY 31 2014 .UPDATE... ISSUED AT 827 AM MDT SAT MAY 31 2014 WATER VAPOR IMAGERY CONTINUES TO SHOW A PLUME OF UPPER LEVEL MOISTURE OVER THE EASTERN 1/3 OF THE AREA. MODELS SHOW DEEP ISENTROPIC LIFT OCCURRING OVER THE SAME AREA CO-LOCATED WITH THE NOSE OF THE LOW LEVEL JET. AS THE DAY PROGRESSES THE NOSE OF THE LOW LEVEL JET MOVES NORTHWARD TAKING THE STRONGER ISENTROPIC LIFT WITH IT. HOWEVER WEAKER ISENTROPIC LIFT WILL CONTINUE OVER THE EASTERN 1/3 AHEAD OF A 700MB SHORT WAVE TROUGH. SOUNDINGS SHOW INSTABILITY REMAINING OVER THE EASTERN PART OF THE AREA INTO THE AFTERNOON SO WILL CONTINUE TO HAVE THE HIGHER PRECIP. CHANCES THERE. TOWARD MID AFTERNOON THE LOW LEVELS DRY OUT CAUSING THE CINH TO INCREASE SO WILL ALLOW PRECIP. CHANCES TO DECLINE AS A RESULT. MEANWHILE ATTENTION THEN SHIFTS TO THE WEST WHERE A DRY LINE WILL MOVE INTO THE AREA. WITH LIFT INCREASING OVER THE WEST AS THE DRY LINE MOVES IN AND 700-500MB MIXING RATIOS ALSO INCREASING...AM THINKING STORMS SHOULD DEVELOP ALONG/BEHIND THE DRY LINE. WILL HAVE HIGHER PRECIP. CHANCES MOVE IN FROM THE WEST AS A RESULT. && .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 252 AM MDT SAT MAY 31 2014 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOWS CLOSES LOW STILL IN PLACE OVER SOUTHERN MISSISSIPPI RIVER VALLEY WITH SW FLOW EXTENDING OVER A LONG FETCH FROM THE PACIFIC OCEAN ACROSS THE CENTRAL ROCKIES AND INTO THE NORTHERN GREAT LAKES REGION. A SHORTWAVE TROUGH EMBEDDED WITHIN THE MEAN SW FLOW IS CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE WITH ITS AXIS EXTENDING SOUTH ACROSS OUR CWA. AT THE SURFACE A STATIONARY FRONT IS APPROXIMATELY EXTENDING FROM NORTH CENTRAL NEBRASKA THROUGH EASTERN COLORADO JUST WEST OF THE KS/CO STATE LINE. REGIONAL COMPOSITE RADAR IMAGERY SHOWS A CLUSTER OF ELEVATED SHOWERS/THUNDERSTORMS OVER NEBRASKA EXTENDING SOUTH ACROSS THE EASTERN HALF OF OUR CWA APPROXIMATELY MATCHING THE LEADING EDGE OF THE SHORTWAVE TROUGH AXIS. WE ARE LOOKING AT A PERSISTENT/ACTIVE PATTERN AS SW FLOW CONTINUES TO BRING A SERIES OF STRONG SHORTWAVE TROUGHS ACROSS THE CENTRAL ROCKIES...AND A LONG FETCH OF PACIFIC MOISTURE INTO THE WESTERN PLAINS. ANOMALOUSLY HIGH PWAT VALUES ARE PROGGED TO REMAIN IN PLACE AND TD VALUES GENERALLY AROUND 60F WILL ALSO LINGER. I CANT COMPLETELY RULE OUT SHOWERS/THUNDERSTORMS ALMOST ANY PERIOD...THOUGH MODEL TIMING DOES GENERALLY FAVOR AFTERNOON/EVENING PERIODS...ESPECIALLY ON SUNDAY. WHILE CAPE PROFILES COULD CERTAINLY SUPPORT SEVERE WEATHER JUST ABOUT EVERY PERIOD OF THE SHORT TERM...THE BEST SHEER IS PROGGED FOR SUNDAY/MONDAY...WHEN ORGANIZED SUPER CELLS WILL BE POSSIBLE (MAINLY IN OUR EAST-SOUTHEAST). INCREASING WINDS SUNDAY COULD ACTUALLY APPROACH ADVISORY CRITERIA SUNDAY AFTERNOON (IF NAM SOLUTION WORKS OUT)...HOWEVER THERE IS STILL A LOT OF SPREAD IN THE SURFACE PATTERN. I BUMPED UP POPS/WINDS (ESPECIALLY SUNDAY)...AND ADDED MENTION OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON/EVENING. I CONSIDERED DOING THE SAME FOR MONDAY...HOWEVER I AM LESS CONFIDENT ON MONDAYS PATTERN AT THIS POINT. STILL WORTH MONITORING. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 252 AM MDT SAT MAY 31 2014 SEASONABLE WEATHER PATTERN EXPECTED THROUGH THE REST OF NEXT WEEK. PRECIP CHANCES EXIST MOST DAYS WITH THE BEST CHANCES ON TUESDAY AND THURSDAY. TEMPS WILL BE NEAR TO ABOVE NORMAL UNTIL A COLD FRONT COMES THROUGH MID-WEEK TO DROP TEMPS DOWN TO SLIGHTLY BELOW NORMAL ON THE LARGE SCALE SOUTHWESTERLY FLOW WILL BE PRESENT ACROSS THE REGION TUESDAY AS AN ELONGATED HIGH PRESSURE PERSISTS FROM WEST TEXAS ACROSS NORTHERN MEXICO AND INTO THE PACIFIC. ALL GLOBAL GUIDANCE IS IN SOLD AGREEMENT WITH THIS ASPECT. A WEAK POSITIVELY TILTED TROUGH WILL DEVELOP OVER THE WESTERN CONUS THROUGH NORTHERN CALIFORNIA...AND NUMEROUS SHORTWAVE TROUGHS WILL MOVE ACROSS THE UPPER GREAT BASIN...THROUGH THE CENTRAL/NORTHERN ROCKIES AND INTO THE PLAINS. THE FINE DETAILS OF SPECIFIC SHORTWAVE STRENGTH/TIMING IS NOT CERTAIN...BUT ON THE WHOLE THIS WILL BE A CONTINUATION OF AN ACTIVE WEATHER PATTERN. ON WEDNESDAY A COLD FRONT WILL WORK ITS WAY SOUTH INTO THE REGION BRINGING COOLER AIR IN ITS WAKE...PROBABLY BECOMING A STATIONARY FRONT AND A FOCUS FOR CONVECTION TO FIRE ON LATER IN THE WEEK. TUESDAY COULD BE ONE OF THE HOTTEST DAYS OF THE YEAR SO FAR WITH 850MB TEMPS SOUTH OF I-70 IN THE LOWER TO MID 30S C...WHICH COULD RESULT IN THE HIGHS IN THE MID 90S...AND MAYBE EVEN A FEW LOCATIONS IN THE FAR SOUTH PART OF THE CWA /TRIBUNE AND LEOTI/ APPROACHING TRIPE DIGITS. A STRONG DRY LINE WILL DEVELOP IN EASTERN COLORADO AND PROGRESS EASTWARD DURING THE DAY...SERVING AS A FOCUS FOR AFTERNOON CONVECTION. LARGE SCALE LIFT WILL BE BEST ALONG/NORTH OF I-70...THOUGH MID-LEVEL MOISTURE COULD BE A PROBLEM DESPITE DEW POINTS NEAR 60 AHEAD OF THE DRY LINE. SHEAR IS QUITE IMPRESSIVE LATE TUESDAY WHICH COULD LEAD TO STRONG/SEVERE STORMS. HAVE SOME CONCERN ABOUT CAP HOLDING AS WELL AS AFOREMENTIONED MOISTURE LIMITATIONS SO WILL KEEP POPS SUB-50 PERCENT FOR NOW. WEDNESDAY A COLD FRONT DIPS IN FROM THE NORTH BRINGING COOLER TEMPS. SOME BUST POTENTIAL FOR HIGHS DEPENDING ON TIMING...HIGHS COULD BE ANYWHERE FROM THE MID 70S TO LOW 90S. WEDNESDAY NIGHT INTO THURSDAY DEVELOPING SHORTWAVE TROUGH IN COLORADO MOVING NORTHEAST COULD PROVIDE ENOUGH LIFT FOR SHOWERS/STORMS TO DEVELOP ALONG/NORTH OF THE FRONT. LIMITED CAPE WILL PREVENT STRONG T-STORMS. CHANCE FOR RAIN INCREASES THURSDAY WITH ABUNDANT LOW LEVEL MOISTURE ADVECTING IN FROM THE EAST SUFFICIENT LARGE-SCALE ASCENT. PWATS AROUND AN INCH AND SLOWER STORM MOTIONS COULD RESULT IN LOCALLY HEAVY RAINFALL. CHANCE FOR STORMS CONTINUES INTO FRIDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1151 AM MDT SAT MAY 31 2014 VFR CONDITIONS FORECAST FOR THE 18Z TAFS. MAIN CONCERN FOR THIS PERIOD WILL BE TIMING OF THUNDERSTORMS FOR KGLD. CURRENT THINKING IS TO HAVE THE THUNDERSTORMS MOVE IN DURING THE EARLY EVENING. HOWEVER THIS COULD CHANGE DEPENDING ON HOW FAST THE DRY LINE MOVES EAST THIS AFTERNOON...WHICH WILL SERVE AS A FOCUS FOR THUNDERSTORM INITIATION. STORMS WILL MOVE SOUTH OF KGLD BY 6Z. KMCK SHOULD REMAIN WELL EAST OF ANY STORM DEVELOPMENT FOR TODAY/TONIGHT. SUNDAY AFTERNOON STORMS ARE MUCH MORE LIKELY FOR KMCK...BUT THIS MAINLY OCCURS AFTER 18Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...JJM AVIATION...JTL
AREA FORECAST DISCUSSION
NWS JACKSON KY
307 PM EDT SAT MAY 31 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 307 PM EDT SAT MAY 31 2014 THE CONVECTIVE ACTIVITY HAS STAYED SOUTH AND WEST OF THE AREA TODAY...MAINLY OVER THE CUMBERLAND PLATEAU...AS WHAT IS LEFT OF THE WEAK BACK DOOR COLD FRONT HAS MOVED BARELY OUT OF THE AREA. THE REMNANTS OF THIS FRONT WILL REMAIN QUASI STATIONARY BEFORE MOVING BACK ACROSS THE AREA TOMORROW. THIS WEAK BOUNDARY CAN BE SEEN IN THE GRADIENT OF THETA E DISPLAY OF THE NAM AND I WOULD BE HARD PRESSED TO ACTUALLY CALL IT A WARM FRONT. THE NET RESULT WILL BE TO BRING SOME ISOLATED TO SCATTERED SHOWERS ACROSS THE AREA DURING THE AFTERNOON AND EARLY EVENING. WITH THE DECREASE IN DEWPOINTS...IT WILL BE A LITTLE COOLER TONIGHT...HOWEVER THE MOISTURE WILL WORK BACK INTO THE AREA TOMORROW AND THE ABOVE AVERAGE LOW TEMPERATURES WILL CONTINUE. THE MODELS WERE IN DECENT AGREEMENT AND STAYED CLOSE TO THE MODEL BLENDS FOR THE FORECASTS. EXPECT DRAY CONDITIONS FOR THE REST OF THE AFTERNOON. THE HRRR MODEL WAS PREDICTING SOME ISOLATED SHOWERS AND THUNDERSTORMS TO MOVE INTO LETCHER AND HARLAN COUNTIES FROM 6 TO 9 PM TONIGHT...HOWEVER CHOSE TO IGNORE THIS DUE TO THE LACK OF ORGANIZATION SHOWING UP ON THE LATEST SATELLITE IMAGERY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 156 PM EDT SAT MAY 31 2014 ZONAL FLOW WILL SET UP AS WE HEAD THROUGH THE UPCOMING WEEK...WITH A FAIRLY PROGRESSIVE PATTERN OF ACTIVE WEATHER ANTICIPATED. MODELS ARE IN FAIRLY GOOD AGREEMENT WITH DIFFERENCES CONFINED TO MAINLY TIMING ISSUES. ON MONDAY...RETURN FLOW WILL DEVELOP WITH HUMID CONDITIONS RETURNING TO THE AREA. VERY FEW TRIGGERS FOR SHOWERS AND STORMS THROUGH THE DAY...BUT SOME TERRAIN INDUCED BOUNDARIES MAY TRIGGER A FEW ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS THROUGH THE DAY. BETTER CHANCES FOR SHOWERS AND STORMS WILL ARRIVE LATE MONDAY NIGHT INTO EARLY TUESDAY AS A SHORTWAVE TROUGH PUSHES ACROSS THE OHIO VALLEY. THE LIFT PROVIDED BY THE WAVE SHOULD ALLOW FOR A BIT BETTER COVERAGE AS IT PUSHES ACROSS THE AREA TOWARDS DAYBREAK TUESDAY. WE MAY SEE A LULL BY AFTERNOON AS SUBSIDENCE BUILDS IN BEHIND THE DEPARTING WAVE. ANOTHER SHORTWAVE IS EXPECTED TO CROSS THE OHIO VALLEY LATE TUESDAY NIGHT INTO WEDNESDAY SKIRTING THE NORTHERN HALF OF THE AREA. THIS WILL BRING ANOTHER CHANCE FOR SHOWERS AND PERHAPS A FEW THUNDERSTORMS. THE REST OF THE WEEK WILL CONTINUE TO FEATURE SHORTWAVE AFTER SHORTWAVE PROGRESSING ACROSS THE OHIO VALLEY...KEEPING THE PERIOD FAIRLY UNSETTLED INTO NEXT WEEKEND. WILL KEEP POPS FAIRLY BROAD THROUGH THE END OF THE WEEK...AS TIMING IN VARIOUS SHORTWAVES MAY DIFFER QUITE A BIT. REGARDLESS...LOOKS LIKE A VERY UNSETTLED PATTERN FOR A WHILE WITH HUMID CONDITIONS CONTINUING. TEMPERATURES WILL REMAIN ABOVE NORMAL THIS WEEK WITH HIGHS INTO THE 80S AND LOWS IN THE 60S TO AROUND 70. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 307 PM EDT SAT MAY 31 2014 FOR THE MOST PART VFR CONDITIONS ARE EXPECTED THROUGH THE AVIATION PERIOD ACROSS EASTERN KENTUCKY. THERE WILL BE SOME MVFR OR LOWER VALLEY FOG AROUND NEAR DAWN TONIGHT...MAINLY SOUTH AND WEST OF THE AREA. THE FOG SHOULD LIFT AND DISSIPATE BY AROUND 13Z...WITH NOTHING MORE THAN A FEW PASSING HIGH CLOUDS THROUGH THE BULK OF THE PERIOD. LOOK FOR MORE MID AND LOWER LEVEL CLOUDS TO ARRIVE FROM THE SOUTHWEST LATE TONIGHT IN ADVANCE OF A RENEWED PICKUP IN MOISTURE. MEANWHILE...WINDS WILL REMAIN LIGHT AND VARIABLE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JJ LONG TERM...KAS AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
156 PM EDT SAT MAY 31 2014 .UPDATE... ISSUED AT 725 AM EDT SAT MAY 31 2014 THE LATEST VISIBLE SATELLITE IMAGERY SHOWS THE TENDRILS OF FOG THROUGH THE SOUTHERN RIVER VALLEYS ACROSS EAST KENTUCKY. THIS WILL DISSIPATE OVER THE NEXT HOUR OR SO. OTHERWISE...THE FORECAST IS RIGHT ON TRACK WITH JUST A FEW NUDGES PER THE LATEST OBS AND TRENDS. THESE ADJUSTMENTS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 400 AM EDT SAT MAY 31 2014 07Z SFC ANALYSIS SHOWS HIGH PRESSURE EASING INTO NORTHEAST KENTUCKY BRINGING A DRIER AIR MASS TO THAT PART OF THE STATE. ON SATELLITE...A WISP OF HIGH CLOUDS REMAINS OVER THIS TRANSITION ZONE BETWEEN THIS DRIER AIR AND THE MORE HUMID CONDITIONS TO THE SOUTHWEST. TEMPERATURES ARE A BIT COOLER IN THE NORTHEAST...TOO...BUT MAINLY A RIDGE TO VALLEY DIFFERENCE IS NOTED THERE AND TO A LESSER EXTENT OVER THE REST OF THE CWA. MOISTURE VARIES MORE BROADLY WITH LOW TO MID 60S DEWPOINTS FOUND TO THE SOUTH AND WEST OF JKL WHILE MID 50S ARE MOVING INTO THE NORTHEAST. WINDS ARE LIGHT AND VARIABLE ACROSS THE CWA THIS NIGHT. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A RIDGE OF HIGH PRESSURE OVER THE WESTERN OHIO VALLEY SOUTHEAST TO THE ATLANTIC COAST WHILE ONE DEEP CLOSED LOW IS MOVING AWAY TO THE NORTHEAST OF KENTUCKY AND ANOTHER WEAKER ONE FILLING OVER THE WEST CENTRAL GULF COAST. IN TIME...THE RIDGE SETTLES OVER EAST KENTUCKY KEEPING ALL THE ENERGY NORTH AND WEST OF EAST KENTUCKY. THE RIDGE DOES WEAKEN QUICKLY... THOUGH...AS IT SINKS TO THE SOUTHEAST ON SUNDAY. THIS SHOULD BE ENOUGH TO ALLOW A BIT MORE MID LEVEL ENERGY TO SEEP INTO KENTUCKY BY SUNDAY EVENING. GIVEN THE GOOD MODEL AGREEMENT HAVE FOLLOWED THE SPECIFICS FROM THE NAM12 AND HRRR MOST CLOSELY FOR THE SHORT TERM PORTION OF THE FORECAST. SENSIBLE WEATHER WILL FEATURE PATCHY VALLEY FOG...LOCALLY DENSE... BURNING OFF BY MID MORNING SETTING THE STAGE FOR A SUNNY...QUIET... AND WARM DAY UNDER RIDGING ALOFT AND SFC HIGH PRESSURE. A FEW MORE CLOUDS WILL ARRIVE LATER TONIGHT AS MOISTURE SEEPS BACK IN FROM THE SOUTHWEST. FOR SUNDAY THERE WILL BE A POTENTIAL FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS BY EVENING WITH THE BETTER CHANCES LOCATED OVER THE CUMBERLAND VALLEY. OTHERWISE...WARM AND INCREASINGLY HUMID WEATHER WILL CLOSE OUT THE WEEKEND. USED THE BCCONSSHORT/ALL AS A STARTING POINT FOR TEMPERATURES... DEWPOINTS...AND WINDS. DID MAKE ADJUSTMENTS TO THESE TONIGHT FOR MORE OF A RIDGE TO VALLEY TEMP SPLIT. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF MOS GUIDANCE LATER SUNDAY THROUGH THE CWA...OTHERWISE KEPT THEM IN THE SINGLE DIGITS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 156 PM EDT SAT MAY 31 2014 ZONAL FLOW WILL SET UP AS WE HEAD THROUGH THE UPCOMING WEEK...WITH A FAIRLY PROGRESSIVE PATTERN OF ACTIVE WEATHER ANTICIPATED. MODELS ARE IN FAIRLY GOOD AGREEMENT WITH DIFFERENCES CONFINED TO MAINLY TIMING ISSUES. ON MONDAY...RETURN FLOW WILL DEVELOP WITH HUMID CONDITIONS RETURNING TO THE AREA. VERY FEW TRIGGERS FOR SHOWERS AND STORMS THROUGH THE DAY...BUT SOME TERRAIN INDUCED BOUNDARIES MAY TRIGGER A FEW ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS THROUGH THE DAY. BETTER CHANCES FOR SHOWERS AND STORMS WILL ARRIVE LATE MONDAY NIGHT INTO EARLY TUESDAY AS A SHORTWAVE TROUGH PUSHES ACROSS THE OHIO VALLEY. THE LIFT PROVIDED BY THE WAVE SHOULD ALLOW FOR A BIT BETTER COVERAGE AS IT PUSHES ACROSS THE AREA TOWARDS DAYBREAK TUESDAY. WE MAY SEE A LULL BY AFTERNOON AS SUBSIDENCE BUILDS IN BEHIND THE DEPARTING WAVE. ANOTHER SHORTWAVE IS EXPECTED TO CROSS THE OHIO VALLEY LATE TUESDAY NIGHT INTO WEDNESDAY SKIRTING THE NORTHERN HALF OF THE AREA. THIS WILL BRING ANOTHER CHANCE FOR SHOWERS AND PERHAPS A FEW THUNDERSTORMS. THE REST OF THE WEEK WILL CONTINUE TO FEATURE SHORTWAVE AFTER SHORTWAVE PROGRESSING ACROSS THE OHIO VALLEY...KEEPING THE PERIOD FAIRLY UNSETTLED INTO NEXT WEEKEND. WILL KEEP POPS FAIRLY BROAD THROUGH THE END OF THE WEEK...AS TIMING IN VARIOUS SHORTWAVES MAY DIFFER QUITE A BIT. REGARDLESS...LOOKS LIKE A VERY UNSETTLED PATTERN FOR A WHILE WITH HUMID CONDITIONS CONTINUING. TEMPERATURES WILL REMAIN ABOVE NORMAL THIS WEEK WITH HIGHS INTO THE 80S AND LOWS IN THE 60S TO AROUND 70. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 735 AM EDT SAT MAY 31 2014 FOR THE MOST PART VFR CONDITIONS ARE EXPECTED THROUGH THE AVIATION PERIOD ACROSS THE CWA. THERE WILL BE SOME MVFR OR LOWER VALLEY FOG AROUND EARLY THIS MORNING...SOUTH AND WEST OF JKL WHERE THE DEWPOINT DEPRESSIONS REMAIN LOWEST. THE FOG SHOULD LIFT AND DISSIPATE BY AROUND 13Z...WITH NOTHING MORE THAN A FEW PASSING HIGH CLOUDS THROUGH THE BULK OF THE PERIOD. LOOK FOR MORE MID AND LOWER LEVEL CLOUDS TO ARRIVE FROM THE SOUTHWEST LATE TONIGHT IN ADVANCE OF A RENEWED PICKUP IN MOISTURE. MEANWHILE...WINDS WILL REMAIN LIGHT AND VARIABLE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...KAS AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1220 PM EDT SAT MAY 31 2014 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE THE WEEKEND WEATHER. THE CHANCE FOR RAIN WILL RETURN TO THE FORECAST ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... VERY WEAK SATURATION THROUGHOUT THE DEPTH OF THE ATMOSPHERIC LAYER OVERHEAD IS BEING OVERCOME BY A SMALL BIT OF LIFTING VIS-A-VIS A WEAK H5 WAVE DIAGNOSED BY THE RAP EARLY THIS AFTERNOON. AS THIS SLIDES SOUTHWARD...CUMULUS DEVELOPMENT SHOULD AGAIN FADE...AS IT HAS ALREADY STARTED TO DO NORTH OF DUBOIS. REGARDLESS...NO SITE WILL BECOME WORSE THAN PARTLY CLOUDY THROUGH THE DAY...WITH MOST SITES MOSTLY SUNNY OR SUNNY AT MOST TIMES. TEMPERATURES STILL LOOK TO BE HEADED IN EXACTLY THE SAME DIRECTION AS YESTERDAY. FRIES && .SHORT TERM /SUNDAY THROUGH TUESDAY/... THE SURFACE HIGH OVER NEW JERSEY WILL SLIDE OFFSHORE SUNDAY INTO SUNDAY NIGHT. WITH UPPER LEVEL RIDGE BUILDING INTO THE REGION...TEMPERATURES WILL CREEP A FEW DEGREES HIGHER ON SUNDAY. BY MONDAY A SURFACE LOW WILL BEGIN TO TRACK ACROSS THE NORTHERN PLAINS. SOUTHWESTERLY WINDS WILL ALLOW FOR SIGNIFICANT MOISTURE TO MOVE INTO THE REGION. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP BY THE AFTERNOON. NOT MUCH WIND SHEAR FOR ANY THUNDERSTORMS TO WORK WITH...BUT HIGH PRECIPITABLE WATER VALUES AND RELATIVELY SLOW STORM MOTIONS COULD ALLOW FOR SOME LOCATIONS TO EXPERIENCE SOME HEAVIER RAINFALL. SHOWERS ARE EXPECTED TO DIMINISH IN COVERAGE MONDAY NIGHT...ALTHOUGH THE WARM FRONT MOVING OVER LAKES HURON AND ONTARIO SHOULD STILL ALLOW THE CHANCE OF RAIN TO CONTINUE. CURRENT MODEL TIMING SHOWS A COLD FRONT MOVING THROUGH LATE MONDAY NIGHT INTO TUESDAY MORNING...WHICH WILL LIMIT OVERALL SEVERE WEATHER POTENTIAL. HAVE CONTINUED WITH LIKELY POPS IN ALL LOCATIONS TUESDAY MORNING...SCALING BACK CHANCES FOR RAIN BY TUESDAY AFTERNOON WITH THE FRONT MOVING EAST OF THE REGION. TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE PERIOD. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... SHWR AND TSTM CHCS WERE RETAINED THROUGH THE LONG TERM PD GIVEN EXPECTATIONS OF LIMITED SOUTHWARD FRONTAL PENETRATION UNDR A FLATTENED RIDGE SCENARIO...WITH SHRTWV PROGRESSION OVR THE QUASISTATIONARY FRONTAL BNDRY IN SPPRT. LONG TERM TEMPS ARE PROGGED AT...OR SLIGHTLY ABOVE AVERAGE WITH THIS FLOW PTN. WPC GUIDANCE SUFFICIENTLY REPRESENTED THE SITUATION AND WAS ONLY MINIMALLY TWEAKED. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... HIGH PRES WL MAINTAIN VFR AND LGT WND THROUGH TNGT. .OUTLOOK.../SUNDAY THROUGH WEDNESDAY/... SHWRS AND TSTMS/RSTRNS ARE LIKELY WITH A MON/TUE CDFNT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
547 PM CDT SAT MAY 31 2014 .UPDATE... ISSUED AT 545 PM CDT SAT MAY 31 2014 THE LATEST ITERATIONS OF THE HRRR...NAMELY THE 20 AND INCOMING 21 UTC RUNS...HAVE AN ACCURATE DEPICTION OF THE ONGOING BROKEN LINE OF STRONG TO SEVERE STORMS ACROSS EASTERN MONTANA AND WYOMING. THUS...WILL FOLLOW THEIR SOLUTIONS FOR POPS THROUGH THE EVENING AND OVERNIGHT. STORMS ARE EXPECTED TO CROSS THE WESTERN NORTH DAKOTA BORDER BETWEEN 02-04 UTC...SUSTAINED BY A STRENGTHENING LOW LEVEL JET. DEEP LAYER SHEAR AND INSTABILITY PROFILES ARE SUPPORTIVE OF THE CONVECTION MAINTAINING ORGANIZATION AS IT CROSSES THE BORDER. THE HRRR WOULD SUGGEST A CONGEALING LINE ACROSS WESTERN NORTH DAKOTA...WITH DAMAGING WINDS THE PRIMARY THREAT...FOLLOWED BY LARGE HAIL AND HEAVY RAINFALL. AS THE STORMS BEGIN TO PROPAGATE INTO MORE STABLE AIR ACROSS CENTRAL NORTH DAKOTA AFTER 06-07 UTC...THEY ARE EXPECTED TO WEAKEN. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 253 PM CDT SAT MAY 31 2014 FOCUS OF CONCERN WILL SHIFT TO WESTERN NORTH DAKOTA LATER TONIGHT WITH SEVERE STORM POTENTIAL IN THE FORM OF DAMAGING WINDS. ACROSS THE EAST MOISTURE QUITE LIMITED ON THE WEST SIDE OF THE STATIONARY FRONT WITH THE BETTER ORGANIZED CONVECTION MOVING ALONG THE STATIONARY FRONT IN FAR SOUTHEAST NORTH DAKOTA THIS AFTERNOON. WILL CONTINUE CURRENT THINKING OF LOW/NIL THUNDERSTORM THREAT THIS AFTERNOON AND EVENING ACROSS THE SOUTHEAST. PRECIPITATION AMOUNTS THERE WITH SHOWERS SHOULD ALSO BE MODEST. A MORE POTENT SYSTEM IS FORMING IN MONTANA WITH STEEP MID LEVEL LAPSE RATES AND GOOD INSTABILITY. MESOSCALE DETERMINISTIC MODELS BRING A MORE ORGANIZED DAMAGING WIND THREAT TO WESTERN NORTH DAKOTA LATER TONIGHT AS A QLCS IS FORECAST BY MODELS TO MOVE INTO WESTERN NORTH DAKOTA AFTER 04-06Z. WILL HIGHLIGHT DAMAGING WINDS LATER TONIGHT WESTERN THIRD OF THE STATE. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS WEST SUNDAY WITH A MORE LIMITED SEVERE WEATHER THREAT. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 253 PM CDT SAT MAY 31 2014 SUNDAY NIGHT AND MONDAY...AN UPPER LEVEL LOW TRACKS EAST ACROSS THE STATE...EXITING THE DEVILS LAKE AND JAMES RIVER VALLEYS ON MONDAY EVENING. AT THE SURFACE...LOW PRESSURE IS FORECAST TO EXTEND UP THE MISSISSIPPI VALLEY INTO IOWA AND MINNESOTA...THEN NORTHWESTWARD ACROSS NORTH DAKOTA. THIS SCENARIO WILL BRING A VERY GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA DURING THIS TIME...THOUGH SEVERE WEATHER (HAIL/TORNADOES) IS NOT EXPECTED AT THIS TIME. KEPT SCATTERED TO NUMEROUS MENTION OF SHOWERS DURING THIS TIME...AND EXPECTING WIDESPREAD PRECIP AMOUNTS OF 0.20 TO 1.00 INCH OF PRECIPITATION FOR THIS 24-HOUR PERIOD. MONDAY NIGHT SHOULD SEE DECREASING CLOUDS AND TUESDAY SHOULD BE A MOSTLY SUNNY DAY AS AN UPPER LEVEL RIDGE BUILDS IN BEHIND THE EXITING UPPER LEVEL LOW. WEDNESDAY THROUGH SATURDAY...WE RETURN TO A MORE ACTIVE REGIME WITH A LOW PRESSURE TROUGH DEVELOPING ACROSS THE ROCKIES AND KEEPING NORTH DAKOTA UNDER A MAINLY SOUTHWESTERLY FLOW ALOFT WITH PERIODIC UPPER LEVEL IMPULSES MOVING ACROSS THE STATE. THUS CHANCES OF SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST MID-WEEK INTO NEXT WEEKEND. REGARDING TEMPERATURES...LOOKING AT HIGHS MAINLY IN THE 60S AND 70S WITH LOWS MAINLY 45 TO 55. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 545 PM CDT SAT MAY 31 2014 STRONG TO SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA ARE FORECAST TO ENTER WESTERN NORTH DAKOTA BY 02-04 UTC...AND HAVE ADDED TEMPO GROUPS FOR THUNDERSTORMS TO KISN AND KDIK TO HIGHLIGHT THE BEST TIMING AND EXPECTED THREAT AT THIS TIME. STORMS MAY APPROACH KMOT AND KBIS LATE...AND WILL MENTION AS VCTS FOR NOW. IFR CONDITIONS IN FOG AND STRATUS ARE POSSIBLE TONIGHT AT KBIS AND KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...WAA LONG TERM...WAA/JV AVIATION...AYD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
106 PM CDT SAT MAY 31 2014 .UPDATE... 18Z TAF DISCUSSION. && .AVIATION... -SHRA/TSRA CURRENTLY AFFECTING CSV WILL DEVELOP/SPREAD WESTWARD THROUGH THE DAY WITH VCSH AT CKV/BNA INTO EARLY EVENING. AMENDMENTS WILL BE POSSIBLE IF CONVECTION LOOKS LIKELY TO DIRECTLY IMPACT AIRPORTS...WITH BRIEF MVFR/IFR CONDITIONS POSSIBLE. OTHERWISE...VFR CONDITIONS ARE ANTICIPATED WITH SCT CUMULUS AND LIGHT EAST WINDS. SOME LIGHT FOG TONIGHT MAY RESULT IN MVFR VIS AT CKV/CSV. SHAMBURGER && .PREV DISCUSSION... /ISSUED 1058 AM CDT SAT MAY 31 2014/ UPDATE... RADAR THIS MORNING INDICATES CONVECTION ALREADY DEVELOPING ON THE PLATEAU WITH OTHER ISOLATED SHOWERS BEGINNING TO FORM FURTHER WEST IN THE UPPER CUMBERLAND REGION. EXPECT SCATTERED SHOWERS AND STORMS TO CONTINUE FORMING OVER EASTERN ZONES THEN GRADUALLY DEVELOP/SPREAD WEST THROUGH THE DAY...AS LATEST HRRR SUGGESTS. WENT AHEAD AND RAISED POPS TO CHANCE AREAWIDE. LOWER LEVELS ON 12Z OHX SOUNDING ARE SLIGHTLY WARMER THAN YESTERDAY...AND WITH AMPLE SUNSHINE OVER WESTERN TWO-THIRDS OF THE CWA THIS SUGGESTS SOME LOCATIONS SUCH AS NASHVILLE MAY TOUCH THE 90 DEGREE MARK. BASED ON THIS AND LATEST OBS...RAISED HIGHS SLIGHTLY AREAWIDE AS WELL. ALSO TWEAKED DEWPOINTS AND SKY COVER BASED ON OBSERVATIONS. SHAMBURGER PREV DISCUSSION... /ISSUED 602 AM CDT SAT MAY 31 2014/ UPDATE...ADDED AVIATION SECTION FOR 12Z TAF`S. AVIATION...BNA/CKV/CSV...UPPER TROUGH OVER THE LOWER MISSISSIPPI VALLEY HAS SHIFTED FAR ENOUGH WEST THAT IT HAS LOST ITS IMPACT ON MIDDLE TENNESSEE`S WEATHER PATTERN. HOWEVER, AN UPPER RIDGE TO OUR EAST HAS STRENGTHENED SO THAT WE KEEP OUR SOUTHERLY FLOW ALOFT, WITH PLENTY OF MOISTURE AND INSTABILITY STILL IN PLACE. LOOK FOR MAINLY ISOLATED ACTIVITY TODAY, WHICH WILL HANDLE WITH VCSH REMARKS DURING THE AFTERNOON PERIOD, WITH SOME LIGHT FOG EARLY THIS MORNING AND THEN AGAIN LATE TONIGHT. OTHERWISE, LOOK FOR VFR WX THE NEXT 24 HRS. PREV DISCUSSION... /ISSUED 351 AM CDT SAT MAY 31 2014/ DISCUSSION... NO SIGNIFICANT CHANGES TO THE FORECAST PACKAGE THIS MORNING AS WARM AND HUMID AIR HAS BEEN AND WILL CONTINUE TO BE THE STORY FOR THE FORESEEABLE FUTURE. WITH THESE CONDITIONS IN PLACE...STORMS REALLY CAN DEVELOP AT ANY TIME...AS THEY HAVE THIS MORNING. AN APPARENT BOUNDARY LEFT OVER FROM STORMS YESTERDAY HAS HELPED TO INITIATE SOME CONVECTION OVER THE PLATEAU. WILL KEEP A 20 POP IN THE FORECAST THROUGH THE MORNING HOURS BUT THE BULK OF TODAY`S ACTIVITY WILL LIKELY BE RELEGATED TO THIS AFTERNOON AS THE ATMOSPHERE HEATS UP. FORECAST SOUNDINGS SUGGEST THAT THESE DIURNALLY DRIVEN STORMS WILL STRUGGLE TO REACH ANYWHERE NEAR SEVERE CRITERIA...SO THE MAIN THREATS WITH ANY OF THIS AFTERNOON`S CONVECTION WILL BE SMALL HAIL AND BRIEF GUSTY WINDS. SUNDAY AND MONDAY SHOULD BE VERY SIMILAR TO TODAY. NO WIND SHEAR AND PLENTY OF SURFACE BASED CAPE MEANS DISORGANIZED THUNDERSTORMS EACH AFTERNOON...WITH SMALL RAIN CHANCES DURING EACH OVERNIGHT PERIOD. BY TUESDAY IT LOOKS LIKE WE MIGHT BEGIN TO SEE A CHANGE IN THUNDERSTORM INTENSITY. WE FINALLY GET OUT FROM UNDER THE INFLUENCE OF THIS PERSISTENT UPPER LEVEL PATTERN AND WHILE TEMPERATURES ALOFT BECOME VERY SUMMERLIKE /-8 TO -9 DEGREES CELSIUS AT 500MB/... FORECAST SOUNDINGS START SHOWING SIGNS OF SOME DRIER AIR ALOFT. WHILE THERE REMAINS NO WIND SHEAR TO SPEAK OF...THE ENTRAINMENT OF DRY AIR INTO SOME OF THESE THUNDERSTORMS COULD SPARK MORE OF A WIND THREAT BY MID-WEEK. WILL MAINTAIN ONLY A CHANCE POP TUESDAY AND WEDNESDAY BUT AN INCREASE WIND THREAT WILL NEED TO BE MONITORED. LONG RANGE GUIDANCE IS SUGGESTING A BOUNDARY DROPPING IN FROM THE NORTH THURSDAY OR FRIDAY. WHILE THIS IS A WEAK FEATURE...ANY FORM OF LIFT IN THIS WARM AND HUMID ENVIRONMENT WILL LIKELY SPELL MORE WIDESPREAD PRECIPITATION. BOTTOM LINE...THESE SUMMERLIKE CONDITIONS WILL PERSIST...WITH AFTERNOON HIGHS IN THE MIDDLE TO UPPER 80S AND OVERNIGHT LOWS IN THE 60S...AND PUSHING 70 DEGREES BY MID-WEEK. UNGER AVIATION...06Z TAF DISCUSSION. CONVECTION HAS DISSIPATED ACROSS THE MID STATE THIS EVENING WITH JUST SOME SCT MID/HIGH LEVEL CLOUDS REMAINING. FOG ALREADY BRINGING IFR VIS TO CSV AND EXPECT IFR TO LIFR CONDITIONS AT BOTH CSV/CKV OVERNIGHT. SCT -SHRA/-TSRA TO DEVELOP ONCE AGAIN LATE SATURDAY MORNING/AFTERNOON WITH VCTS AT ALL AIRPORTS. LIGHT EAST WINDS ANTICIPATED THROUGHOUT THE TAF PERIOD. SHAMBURGER && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1058 AM CDT SAT MAY 31 2014 .UPDATE... RADAR THIS MORNING INDICATES CONVECTION ALREADY DEVELOPING ON THE PLATEAU WITH OTHER ISOLATED SHOWERS BEGINNING TO FORM FURTHER WEST IN THE UPPER CUMBERLAND REGION. EXPECT SCATTERED SHOWERS AND STORMS TO CONTINUE FORMING OVER EASTERN ZONES THEN GRADUALLY DEVELOP/SPREAD WEST THROUGH THE DAY...AS LATEST HRRR SUGGESTS. WENT AHEAD AND RAISED POPS TO CHANCE AREAWIDE. LOWER LEVELS ON 12Z OHX SOUNDING ARE SLIGHTLY WARMER THAN YESTERDAY...AND WITH AMPLE SUNSHINE OVER WESTERN TWO-THIRDS OF THE CWA THIS SUGGESTS SOME LOCATIONS SUCH AS NASHVILLE MAY TOUCH THE 90 DEGREE MARK. BASED ON THIS AND LATEST OBS...RAISED HIGHS SLIGHTLY AREAWIDE AS WELL. ALSO TWEAKED DEWPOINTS AND SKY COVER BASED ON OBSERVATIONS. SHAMBURGER && .PREV DISCUSSION... /ISSUED 602 AM CDT SAT MAY 31 2014/ UPDATE...ADDED AVIATION SECTION FOR 12Z TAF`S. AVIATION...BNA/CKV/CSV...UPPER TROUGH OVER THE LOWER MISSISSIPPI VALLEY HAS SHIFTED FAR ENOUGH WEST THAT IT HAS LOST ITS IMPACT ON MIDDLE TENNESSEE`S WEATHER PATTERN. HOWEVER, AN UPPER RIDGE TO OUR EAST HAS STRENGTHENED SO THAT WE KEEP OUR SOUTHERLY FLOW ALOFT, WITH PLENTY OF MOISTURE AND INSTABILITY STILL IN PLACE. LOOK FOR MAINLY ISOLATED ACTIVITY TODAY, WHICH WILL HANDLE WITH VCSH REMARKS DURING THE AFTERNOON PERIOD, WITH SOME LIGHT FOG EARLY THIS MORNING AND THEN AGAIN LATE TONIGHT. OTHERWISE, LOOK FOR VFR WX THE NEXT 24 HRS. PREV DISCUSSION... /ISSUED 351 AM CDT SAT MAY 31 2014/ DISCUSSION... NO SIGNIFICANT CHANGES TO THE FORECAST PACKAGE THIS MORNING AS WARM AND HUMID AIR HAS BEEN AND WILL CONTINUE TO BE THE STORY FOR THE FORESEEABLE FUTURE. WITH THESE CONDITIONS IN PLACE...STORMS REALLY CAN DEVELOP AT ANY TIME...AS THEY HAVE THIS MORNING. AN APPARENT BOUNDARY LEFT OVER FROM STORMS YESTERDAY HAS HELPED TO INITIATE SOME CONVECTION OVER THE PLATEAU. WILL KEEP A 20 POP IN THE FORECAST THROUGH THE MORNING HOURS BUT THE BULK OF TODAY`S ACTIVITY WILL LIKELY BE RELEGATED TO THIS AFTERNOON AS THE ATMOSPHERE HEATS UP. FORECAST SOUNDINGS SUGGEST THAT THESE DIURNALLY DRIVEN STORMS WILL STRUGGLE TO REACH ANYWHERE NEAR SEVERE CRITERIA...SO THE MAIN THREATS WITH ANY OF THIS AFTERNOON`S CONVECTION WILL BE SMALL HAIL AND BRIEF GUSTY WINDS. SUNDAY AND MONDAY SHOULD BE VERY SIMILAR TO TODAY. NO WIND SHEAR AND PLENTY OF SURFACE BASED CAPE MEANS DISORGANIZED THUNDERSTORMS EACH AFTERNOON...WITH SMALL RAIN CHANCES DURING EACH OVERNIGHT PERIOD. BY TUESDAY IT LOOKS LIKE WE MIGHT BEGIN TO SEE A CHANGE IN THUNDERSTORM INTENSITY. WE FINALLY GET OUT FROM UNDER THE INFLUENCE OF THIS PERSISTENT UPPER LEVEL PATTERN AND WHILE TEMPERATURES ALOFT BECOME VERY SUMMERLIKE /-8 TO -9 DEGREES CELSIUS AT 500MB/... FORECAST SOUNDINGS START SHOWING SIGNS OF SOME DRIER AIR ALOFT. WHILE THERE REMAINS NO WIND SHEAR TO SPEAK OF...THE ENTRAINMENT OF DRY AIR INTO SOME OF THESE THUNDERSTORMS COULD SPARK MORE OF A WIND THREAT BY MID-WEEK. WILL MAINTAIN ONLY A CHANCE POP TUESDAY AND WEDNESDAY BUT AN INCREASE WIND THREAT WILL NEED TO BE MONITORED. LONG RANGE GUIDANCE IS SUGGESTING A BOUNDARY DROPPING IN FROM THE NORTH THURSDAY OR FRIDAY. WHILE THIS IS A WEAK FEATURE...ANY FORM OF LIFT IN THIS WARM AND HUMID ENVIRONMENT WILL LIKELY SPELL MORE WIDESPREAD PRECIPITATION. BOTTOM LINE...THESE SUMMERLIKE CONDITIONS WILL PERSIST...WITH AFTERNOON HIGHS IN THE MIDDLE TO UPPER 80S AND OVERNIGHT LOWS IN THE 60S...AND PUSHING 70 DEGREES BY MID-WEEK. UNGER AVIATION...06Z TAF DISCUSSION. CONVECTION HAS DISSIPATED ACROSS THE MID STATE THIS EVENING WITH JUST SOME SCT MID/HIGH LEVEL CLOUDS REMAINING. FOG ALREADY BRINGING IFR VIS TO CSV AND EXPECT IFR TO LIFR CONDITIONS AT BOTH CSV/CKV OVERNIGHT. SCT -SHRA/-TSRA TO DEVELOP ONCE AGAIN LATE SATURDAY MORNING/AFTERNOON WITH VCTS AT ALL AIRPORTS. LIGHT EAST WINDS ANTICIPATED THROUGHOUT THE TAF PERIOD. SHAMBURGER && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
305 PM EDT SAT MAY 31 2014 .SYNOPSIS... A BACKDOOR COLD FRONT WILL MOVE SOUTH INTO SOUTH CAROLINA TONIGHT. HIGH PRESSURE BUILDS SOUTHWARD FROM THE MID-ATLANTIC REGION TONIGHT INTO SUNDAY. HIGH PRESSURE ALOFT EARLY NEXT WEEK WILL BRINGING WARM AND MORE HUMID CONDITIONS BACK TO OUR REGION ALONG WITH INCREASING CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH SUNDAY/... AS OF 330 PM EDT SATURDAY... HIGH PRESSURE TRAVELS SOUTHEAST TONIGHT INTO SUNDAY...AS 500 MB RIDGE BUILDING TO OUR WEST. DO NOT BELIEVE THE NAM CONVECTION WITH THE WEAK SHORTWAVE MOVING ACROSS WEST VIRGINIA THIS AFTERNOON INTO THIS EVENING. HOWEVER...STILL CANNOT COMPLETELY RULE OUT ISOLATED SHOWERS FOR THE NW NC MOUNTAIN COUNTIES THIS AFTERNOON INTO THIS EVENING AS A RESULT OF UPSLOPE EASTERLY FLOW AND DIFFERENTIAL HEATING NEAR THE BAROCLINIC ZONE. THE HRRR HAS BACK OFF ON POTENTIAL FOR CONVECTION...WHILE RNK-WRFARW...GFS AND ECMWF SUPPORT THE MENTION OF SHOWERS ACROSS THE SOUTHERN PORTIONS OF FORECAST AREA. CLEAR TO PARTLY CLOUDY SKIES EXPECTED TONIGHT. SOME PATCHY FOG MAY BE POSSIBLE OVERNIGHT IN THE FAVOR RIVER VALLEY LOCATIONS. BUT WITH DRY AIR DO NOT EXPECT ANY DENSE FOG LIKE PREVIOUS COUPLE NIGHTS. WENT WITH LOW TEMPERATURES TONIGHT CLOSE TO THE ADJMETBC WITH READINGS FROM THE UPPER 40S IN THE NORTHWEST TO THE UPPER 50S ALONG THE FOOTHILLS OF THE SOUTHERN BLUE RIDGE. HIGH PRESSURE CONTINUES TO SLIDE EASTWARD INTO THE ATLANTIC ON SUNDAY AND PUSHES OFFSHORE SUNDAY NIGHT. USED ADJMAVBC FOR HIGH TEMPERATURES ON SUNDAY WITH VALUES FROM THE LOWER 70S IN THE MOUNTAINS TO THE UPPER 70S IN THE PIEDMONT. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... AS OF 240 PM EDT SATURDAY... INCREASING HUMIDITY THIS PERIOD AS SFC HIGH OVERHEAD SUNDAY NIGHT SHIFTS SOUTHEAST OFF THE COAST BY TUESDAY MORNING. AN UPPER LOW DEVELOPS OVER LAKE SUPERIOR AND SHIFTS SLOWLY EWD INTO SRN ONTARIO THROUGH TUESDAY NIGHT. THE UPPER RIDGE EARLY IN THE PERIOD WILL FLATTEN AS A RESULT. AT THIS TIME...IT LOOKS LIKE MONDAY WILL BE MAINLY DRY...WITH SOME HINT OF CONVECTION DEVELOPING OVER THE MTNS IN THE HEAT OF THE DAY. GOING TO SEE SOME UPPER DIFLUENCE TUESDAY WITH A WAVE MOVING OVER THE OHIO VALLEY AND ENTERING THE MOUNTAINS BY DAYS END. NOTICED MODELS HINTING AT A POSSIBLE LINE OF CONVECTION PER ORIENTATION OF THE UPPER FLOW AND THE PVA FORECAST. WITH ALL MODELS PAINTING MORE QPF IN THE WEST TUESDAY WILL HIGHLIGHT LIKELY POPS WEST OF THE INTERSTATE 81 CORRIDOR...WITH 40-50 POPS TO THE BLUE RIDGE AND 30 POPS PIEDMONT. LOWS IN THE 50S SUNDAY NIGHT WARM TO THE LOWER 60S MONDAY NIGHT...AS DEWPOINTS HEAD INTO THE UPPER 50S TO LOWER 60S. HIGHS MONDAY WILL RANGE FROM THE MID TO UPPER 70S HIGHER RIDGES OF THE WEST...TO LOWER 80S VALLEYS...AND MID 80S EAST...WHICH WILL BE ABOUT 1-4 DEGREES WARMER THAN MOS. WITH DEWPOINTS STILL RELATIVELY DRY...THINK AIRMASS WILL HEAT UP FASTER WITH LESS CLOUDS. TUESDAY IS FORECAST TO BE WARMER ESPECIALLY IN THE PIEDMONT SINCE 8H TEMPS PUSH FROM +13-16C MONDAY TO +16-18C TUESDAY. SHOULD ALSO BE A COUPLE DEGREES WARMER WEST BUT WILL HAVE TO CONSIDER TIMING OF POSSIBLE LINE OF SHRA/TSRA BY EARLY AFTERNOON WHICH MAY IMPACT THE TEMP RISE. ATTM...WE ARE GOING WITH LOWER TO MID 80S WEST...70S HIGHEST RIDGES...TO NEAR 90 SOUTHEAST. THIS ASSOCIATED SHORTWAVE EXITS EAST TUESDAY NIGHT WITH YET ANOTHER WAVE MOVING TOWARD THE KY/VA BORDER BY 12Z WED. WILL LINGER CHANCE POPS IN THE EVENING TUESDAY...WITH SLIGHT CHANCE TO LOW CHANCE WEST AFTER MIDNIGHT. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 200 PM EDT SATURDAY.. GOING TO CONTINUE TO BE IN AN ACTIVE PATTERN....AS FRONTAL BOUNDARY ALIGNS IN A WEST-EAST SETUP GIVEN FLATTER FLOW ALOFT. TEMPS WILL BE WARM BUT WILL BE IMPACTED BY SHOWERS AND STORMS FROM TIME TO TIME. MODELS IN GENERAL IN AGREEMENT IN KEEPING THE FRONTAL BOUNDARY ALIGNED THE CENTRAL PLAINS...EAST TO THE MID ATLANTIC WED-FRIDAY AND SLOWLY SAGGING SOUTH INTO VA BY FRIDAY-SATURDAY. TIMING ISSUES WITH MODELS AND SHORTWAVES/ASSOCIATED SFC LOWS. ATTM...WILL KEEP PERSISTENCE IN THE FORECAST MAINTAINING HIGHER THREAT OF SHRA/TSRA IN THE AFTERNOON/EVENING AND LOWER AFTER MIDNIGHT-MORNING TIME FRAME. LATEST 12Z ECMWF ACTUALLY TRYING TO BUILD THE 5H RIDGE BACK NORTH INTO THE CAROLINAS BY NEXT SATURDAY WHICH BUCKLES THE FRONT NORTH INTO MD/PA. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... AS OF 130 PM EDT SATURDAY... DIFFUSE BACKDOOR FRONT ACROSS REGION WILL DRIFT SOUTHWEST THIS AFTERNOON AS HIGH PRESSURE BUILDS SOUTHWARD FROM THE MID- ATLANTIC REGION. THE PUNCH OF DRIER AIR HAS ERODE THE PERSISTENT LOW CLOUD COVER BANKED UP AGAINST THE SOUTHERN BLUE RIDGE. SCT TO BKN CLOUDS THIS AFTERNOON SHOULD DIMINISH OR DISSIPATE THIS EVENING INTO TONIGHT. WITH THE DRIER NE/E FLOW...DO NOT EXPECT DENSE FOG LIKE PREVIOUS COUPLE NIGHTS. HOWEVER...SOME MVFR RIVER VALLEY FOG POSSIBLE IN A FEW RIVER VALLEYS. LWB HAS THE BEST CHANCE TO SEE ANY FOG DEVELOPMENT OVERNIGHT. OUTSIDE OF MORNING FOG...VFR CONDITIONS WILL PREVAIL SUNDAY. WINDS NE-SE AROUND 8-10KTS THIS AFTERNOON DIMINISH TONIGHT AS HIGH PRESSURE STRENGTHENS ACROSS THE NE U.S. ON SUNDAY...WINDS WILL BE SOUTHEAST AT 5 TO 10 KTS. HIGH CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... VFR CONDITIONS WILL PREVAIL FOR THE MONDAY...EXCEPT FOR BRIEF FOG OR LOW CLOUDS OVERNIGHT IN MOUNTAIN VALLEYS. THE NEXT CHANCE AT SCATTERED SHOWER AND THUNDERSTORM ACTIVITY RETURNS BY MONDAY AFTERNOON AND INCREASING POPS INTO THE MID WEEK PERIOD. && .EQUIPMENT... THE BLF OBSERVATION WILL REMAIN UNAVAILABLE UNTIL FURTHER NOTICE BECAUSE OF A COMMS ISSUE. WE ARE STILL ABLE TO DIAL INTO THE SITE. HOWEVER...THE BLF TAF WILL REMAIN AMD NOT SKED UNTIL THE COMMS ISSUE IS RESOLVED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...KK SHORT TERM...WP LONG TERM...WP AVIATION...KK/RAB EQUIPMENT...RAB/WP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
327 PM MDT SAT MAY 31 2014 .SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY NIGHT) ISSUED AT 300 PM MDT SAT MAY 31 2014 SEVERE POTENTIAL FOR THIS AFTN AND EVENING IS STILL UNCERTAIN...MAINLY DUE TO THE MARGINAL FLOW ALOFT AND DEEP LAYER SHEAR. SPC MESOANALYSIS SHOWS GOOD INSTABILITY WITH MLCAPES OF 1000-1500 J/KG ALONG AND EAST OF THE LARAMIE RANGE. HOWEVER...BULK SHEAR OF 25-30 KTS IS STILL RATHER MARGINAL TO GET STORMS MORE ORGANIZED INTO SUPERCELLS. A FEW CELLS HAVE DEVELOPED IN THE CHUGWATER AREA OVER THE PAST HOUR AND HAVE NOT REALLY STRENGTHENED AS IT PUSHED OVER THE PLAINS. MODELS DO INDICATE THAT THE BULK SHEAR INCREASES TO 35-40 KTS BY AROUND 00Z AS THE UPPER TROUGH PUSHES INTO WESTERN WY. STRONGEST FORCING FOR ASCENT FROM THE TROUGH IS GENERALLY ACROSS THE NORTHERN COUNTIES. THE HRRR MODEL SHOWS INITIALLY DISCRETE CELLS OVER PLATTE AND CONVERSE COUNTIES LATE THIS AFTN THAT MERGE INTO A LINE/MULTICELL CLUSTER OVER THE NORTHERN NEBRASKA PANHANDLE. WILL MAINTAIN THE SVR WORDING WITH LARGE HAIL IN THE GRIDS SINCE CONDITIONS ARE BECOMING MORE FAVORABLE BY THIS EVENING. UPPER TROUGH PUSHES ACROSS WY OVERNIGHT WITH THE TROUGH AXIS OVER THE NEBRASKA PANHANDLE BY SUN AFTN. SFC FRONT ASSOCIATED WITH THE UPPER TROUGH IS PROGGED TO HAVE MOVED OVER MUCH OF THE CWA BY 18Z SUN WITH BOUNDARY LAYER FLOW TURNING WEST TO NORTHWEST. THE DRIER AIRMASS BEHIND THE FRONT COMBINED WITH LARGE SCALE SUBSIDENCE SHOULD LIMIT STORM COVERAGE COMPARED TO THIS AFTN. THERE IS SOME DISAGREEMENT ON HOW MOIST IT WILL BE OVER THE PANHANDLE IN THE POST FRONTAL AIRMASS...WITH THE GFS SHOWING DEWPOINTS IN THE 40S AND THE MORE MOIST NAM IN THE MID 50S. TEND TO THINK THAT THE STRONGEST STORMS WILL BE EAST OF THE CWA IN THIS PATTERN...HOWEVER WILL HAVE TO WATCH FAR EASTERN ZONES SINCE WINDS ALOFT ARE STRONGER AND BULK SHEAR ARE 40-45 KTS. SPC HAS MUCH OF THE PANHANDLE IN A SLIGHT RISK FOR TOMORROW. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 300 PM MDT SAT MAY 31 2014 UPPER LEVEL RIDGING CONTINUING TO BE FORECAST TO MOVE INTO WESTERN WYOMING MONDAY. FOR THE MOST PART...MONDAY LOOKS TO BE OUR DRIEST DAY. LATEST NAM/WRF IS SHOWING SOME POPS DOWN OVER THE SOUTHERN PANHANDLE MONDAY EVENING. DO THINK FOR THE MOST PART THOUGH THAT EVERYONE WILL BE DRY. TUESDAY CONTINUES TO SHOW AN INCREASED THREAT FOR SEVERE THUNDERSTORMS AS THE UPPER RIDGE MOVES EAST AND A STRONG SHORTWAVE MOVES INTO SOUTHWEST WYOMING. LOW LEVEL SOUTHEASTERLY WINDS IN THE PANHANDLE WITH LOW LEVEL POOLING OF MOISTURE TUESDAY MORNING. AFTER 18Z...GFS SHOWING AN 80 TO 85KT JET TO MOVE THROUGH SOUTHERN WYOMING...WITH MUCH OF OUR NORTHERN COUNTIES IN THE FAVORABLE LFQ OF THE JET. SHORTWAVE MOVES THROUGH DURING THE HEAT OF THE DAY. FAVORABLE SHEAR FOR LARGE HAIL ACROSS CONVERSE...NIOBRARA COUNTIES IN EAST CENTRAL WYOMING AND THE NORTHERN PANHANDLE. SINCE IT HAS BEEN SHOWING THIS SETUP FOR SEVERAL DAYS NOW...WENT AHEAD AND ADDED SEVERE THUNDERSTORMS INTO THE FORECAST FOR TUESDAY AFTERNOON/EARLY EVENING. ANOTHER WEAK SHORTWAVE FOR WEDNESDAY SHOULD KEEP SOME LOW CHANCE POPS. SEVERE CHANCES SHOULD BE MINIMAL AS JET SAGS SOUTH INTO SOUTHERN COLORADO...BUT WE WILL NEED TO WATCH. STRONGER SHORTWAVE LOOKS TO MOVE THROUGH THE AREA FRIDAY INTO SATURDAY. BOTH THE GFS AND ECMWF VERY SIMILAR ON WHERE POPS ARE EXPECTED TO BREAK OUT FRIDAY EVENING. COULD BE OUR NEXT SEVERE THUNDERSTORM CHANCE AT THAT TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING) ISSUED AT 1100 AM MDT SAT MAY 31 2014 CONVECTION TO GET GOING LATER THIS AFTERNOON FOR AIRPORTS EAST OF THE LARAMIE RANGE IN SOUTHEAST WYOMING AND AFTER 23Z FOR OUR NEBRASKA PANHANDLE AIRPORTS. SOME QUESTION ON CAPPING INHIBITING CONVECTION OVER THE SOUTHERN PANHANDLE AND LATEST HRRR FORECAST SUGGESTS THAT KSNY AND MAYBE KBFF WILL STAY DRY. DO THINK WE STILL HAVE A CHANCE AND ADDED VCTS TO THESE TAFS AFTER 23Z. WILL CONTINUE TO MONITOR FOR THE 00Z TAFS. SHOULD NOT SEE THE WIDESPREAD STRATUS THAT WE SAW THIS MORNING FOR SUNDAY MORNING AS WINDS TURN MORE WESTERLY. ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON/EVENING. SOME STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED WITH STRONG WINDS AND LARGE HAIL. && .FIRE WEATHER... ISSUED AT 300 PM MDT SAT MAY 31 2014 MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. A MOIST AIRMASS IN PLACE THIS AFTERNOON...ESPECIALLY TO THE EAST OF THE LARAMIE RANGE WHERE SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THIS EVENING. A FRONT WILL PASS OVER THE REGION ON SUN MORNING WITH DRIER CONDITIONS BEHIND IT ALONG WITH BREEZY WEST WINDS. MINIMUM AFTERNOON HUMIDITY VALUES WILL FALL TO AROUND 20 PERCENT FOR AREAS TO THE WEST OF THE LARAMIE RANGE BY EARLY NEXT WEEK. && .HYDROLOGY... ISSUED AT 300 PM MDT SAT MAY 31 2014 RIVER FLOODING WILL CONTINUE ALONG THE LITTLE SNAKE...UPPER NORTH PLATTE...AND LARAMIE RIVERS THROUGH EARLY NEXT WEEK. A DRIER WEATHER PATTERN IS EXPECTED TO DEVELOP OVER THE AREA OVER THE NEXT FEW DAYS AS MOISTURE DECREASES. TEMPERATURES THIS WEEKEND WILL BE WARM ENOUGH TO PRODUCE SOME SNOWMELT ACROSS THE SIERRA MADRE AND SNOWY RANGES BUT AMOUNTS SHOULD BE LESS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...FINCH LONG TERM...CLAYCOMB AVIATION...CLAYCOMB FIRE WEATHER...FINCH HYDROLOGY...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1100 AM MDT SAT MAY 31 2014 .UPDATE... ISSUED AT 1044 AM MDT SAT MAY 31 2014 CHANCE OF SVR TSTMS OVER THE PLAINS CONTINUES TO LOOK GOOD FOR THIS AFTN. DEWPOINTS ARE CURRENTLY IN THE LOW-TO-MID 50S TO THE EAST OF THE LARAMIE RANGE WITH GOOD SFC HEATING. THE RUC MODEL INDICATES SBCAPES OF 1500 J/KG BY LATE AFTN WITH BULK SHEAR OF 35-40 KTS. LARGE HAIL IS THE PRIMARY THREAT WITH GOOD DEEP LAYER SHEAR BUT WEAK LLVL SHEAR. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 245 AM MDT SAT MAY 31 2014 A FEW LIGHT SHOWERS STILL OVER THE FAR EAST PARTS OF THE CWA EARLY THIS MORNING WILL EXIT SHORTLY AS AN UPPER IMPULSE MOVES ON NORTHEAST OF THE AREA WITH SOME CLEARING NOTED OVER WESTERN SECTIONS OF THE CWA. MEANWHILE UPPER TROF OVER THE PACIFIC NW WILL EDGE EASTWARD TODAY AND TONIGHT WITH ON BATCH OF ENERGY EJECTING ACROSS THE NORTHERN ROCKYS INTO THE NORTHERN PLAINS ON SUNDAY. THE APPROACH OF THE UPPER TROF WILL INCREASE UPPER WINDS OVER THE CWA TODAY AND WITH LOW LEVEL SELY FLOW SHEAR VALUES WILL BE HIGHER TODAY. THE CLEARING THAT HAS OCCURRED WILL ALLOW FOR MORE WARMING OVER PARTS OF THE CWA TODAY THUS SHOULD SEE MORE INSTABILITY FOR THE PRODUCTION OF WDLY SCTD SHOWERS AND TSTMS THIS AFTERNOON... SPREADING EAST INTO THIS EVENING. A FEW STRONG OR SEVERE STORMS POSSIBLE ESPECIALLY WITH NORTHWARD EXTENT WITH HAIL THE MAIN THREAT INTO THIS EVENING. ACTIVITY SHOULD ALSO PERSIST LONGER TONIGHT WITH THE APPROACH OF THE INITIAL SHORTWAVE. SUNDAY A LITTLE MORE TRICKY AS INITIAL SHORTWAVE WILL EJECT INTO THE NORTHERN PLAINS AND PUSH A MODEST FRONT ACROSS THE CWA WITH A BIT DRIER AIR BEHIND IT. BETTER INSTABILITY SHOULD BE NUDGED TO THE EAST BUT A FEW STRONG STORMS STILL POSSIBLE OVER THE PANHANDLE SUNDAY AFTERNOON. COOLER AND MORE STABLE AIR WILL THEN ARRIVE SUNDAY NIGHT WITH WESTERLY UPPER FLOW WITH MONDAY LOOKING MAINLY DRY AND MILD. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT ISSUED AT 245 AM MDT SAT MAY 31 2014 ACTIVE WEATHER PATTERN LOOKING TO SET UP FOR THE EXTENDED FORECAST PERIOD. MODELS SHOWING THE FORECAST AREA BEING THE CONFLUENCE BETWEEN THE NORTHERN STREAM AND THE SOUTHERN STREAM THROUGH MUCH OF NEXT WEEK. OVERALL PATTERN IS VERY MESSY SO VERY TOUGH TO TIME THE HIGHEST CHANCES FOR PRECIPITATION BUT IT DOES LOOK LIKE ALMOST EVERY DAY THERE WILL BE A SHOT OF AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS FROM THE LARAMIE RANGE EASTWARD. TEMPERATURES IN THIS PATTERN SHOULD BE FAIRLY CLOSE TO THE NORM BUT ABOVE NORMAL PRECIPITATION CHANCES IN THE EAST. CURRENTLY THE MODELS MOSTLY KEEPING THE SNOWY AND SIERRA MADRE RANGES ON THE DRIER SIDE OF THINGS...WHICH IF CORRECT WOULD BE FAVORABLE FOR A SLOWER SNOWMELT...ESPECIALLY AS TEMPERATURES WILL BE AROUND 10 DEGREES COOLER THAN HAS OCCURRED OVER THE LAST SEVERAL DAYS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY) ISSUED AT 1100 AM MDT SAT MAY 31 2014 CONVECTION TO GET GOING LATER THIS AFTERNOON FOR AIRPORTS EAST OF THE LARAMIE RANGE IN SOUTHEAST WYOMING AND AFTER 23Z FOR OUR NEBRASKA PANHANDLE AIRPORTS. SOME QUESTION ON CAPPING INHIBITING CONVECTION OVER THE SOUTHERN PANHANDLE AND LATEST HRRR FORECAST SUGGESTS THAT KSNY AND MAYBE KBFF WILL STAY DRY. DO THINK WE STILL HAVE A CHANCE AND ADDED VCTS TO THESE TAFS AFTER 23Z. WILL CONTINUE TO MONITOR FOR THE 00Z TAFS. SHOULD NOT SEE THE WIDESPREAD STRATUS THAT WE SAW THIS MORNING FOR SUNDAY MORNING AS WINDS TURN MORE WESTERLY. ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON/EVENING. SOME STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED WITH STRONG WINDS AND LARGE HAIL. && .FIRE WEATHER... ISSUED AT 245 AM MDT SAT MAY 31 2014 CONCERNS WILL REMAIN QUITE LOW INTO EARLY NEXT WEEK WITH NON- CRITICAL CONDITIONS EXPECTED TO CONTINUE. TODAY SHOULD SEE THE LARGEST CONCENTRATION OF SHOWERS AND TSTMS ESPECIALLY OVER AND EAST OF THE MTNS. DRIER AIR WILL ACT TO REDUCE ACTIVITY SUNDAY INTO EARLY NEXT WEEK. && .HYDROLOGY... ISSUED AT 245 AM MDT SAT MAY 31 2014 RIVER FLOODING WILL CONTINUE ALONG THE LITTLE SNAKE...UPPER NORTH PLATTE...AND LARAMIE RIVERS THROUGH EARLY NEXT WEEK. A DRIER WEATHER PATTERN IS EXPECTED TO DEVELOP OVER THE AREA OVER THE NEXT FEW DAYS AS MOISTURE DECREASES. TEMPERATURES THIS WEEKEND WILL BE WARM ENOUGH TO PRODUCE SOME SNOWMELT ACROSS THE SIERRA MADRE AND SNOWY RANGES BUT AMOUNTS SHOULD BE LESS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...FINCH SHORT TERM...RE LONG TERM...SML AVIATION...CLAYCOMB FIRE WEATHER...RE HYDROLOGY...RE