Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/29/12


AREA FORECAST DISCUSSION
NWS DENVER CO
1125 AM MDT WED JUN 27 2012 .UPDATE... && .SHORT TERM...BIGGEST CHANGE TO THE FORECAST...MAINLY THE FIRE WEATHER FORECAST...WAS TO ISSUE A SHORT FUSE RED FLAG WARNING FOR THE FRONT RANGE FOOTHILLS AND SOUTH PARK. THIS WARNING WILL GO IN EFFECT AT NOON TODAY AND WILL RUN UNTIL 8 PM THIS EVENING. MAIN CONCERN WILL BE THUNDERSTORMS...SOME DRY...PRODUCING STRONG GUSTY AND ERRATIC OUTFLOW WINDS AND FREQUENT CLOUD-TO-GROUND LIGHTNING. OTHERWISE CURRENTLY MONITORING A WEAK COOL FRONT SLOWLY BACKING SOUTHWEST ACROSS THE NORTHEAST PLAINS OF COLORADO. BEHIND THIS FRONTAL BOUNDARY...NOW SHOWING UP AS A FINE LINE ON RADAR HAS SLOWED WARMING ACROSS THE NORTHEAST CORNER OF THE STATE. THEREFORE HAVE LOWERED MAX TEMPERATURES FOR TODAY OUT THAT WAY BY A DEG OR TWO. NEXT...CLOUD BAND MOVING VERY SLOWLY EASTWARD ACROSS THE MOUNTAINS AN INDICATION OF MID AND UPPER LEVEL MOISTURE. THE CLOUDS HAVE HELPED TO SLOW WARMING IN THE HIGH COUNTRY...BUT AT THE SAME TIME...ALSO STABILIZED THE BNDRY LAYER SOME. ONLY THUNDERSTORM DEVELOPMENT THUS FAR THIS MORNING HAS BEEN CONFINED UP ALONG THE COLORADO/WYOMING BORDER JUST NORTH OF THE HIGH PARK WILDFIRE IN LARIMER COUNTY. IN THE NEXT SEVERAL HOURS...BELIEVE WILL SEE T-STORM DEVELOPMENT ON THE INCREASE AS A WEAK MID-LEVEL SHORTWAVE TROUGH SWINGS UP FROM THE FOUR CORNERS AREA. THIS MAY BE ENOUGH TO SET OFF SCATTERED T-STORMS IN THE MTNS AND FOOTHILLS AND ISOLATED T-STORMS LATER THIS AFTERNOON ON THE PLAINS. NEW FORECAST GRIDS REFLECT THESE CHANGES. .AVIATION...EXPECT VFR CONDITIONS AT DENVER AREA AIRPORTS FOR AT LEAST THE NEXT FEW HOURS. AFTER 2 PM MDT...DENVER AIRPORTS COULD SEE ISOLATED TO WIDELY SCATTERED THUNDERSTORMS MOVING ACROSS THE DENVER METRO AREA. A FEW STORMS MAY PRODUCE FREQUENT CLOUD-TO- GROUND LIGHTNING AND GUSTY AND ERRATIC OUTFLOW WINDS OF 30 TO 45 MPH. STORM ACTIVITY IN THE DENVER AREA IS EXPECTED TO DROP OUT IN THE EVENING. NOTE...A SHIFT TO A SOUTHWEST WIND THIS EVENING COULD TRANSPORT SMOKE FROM THE LARGE WILDFIRE IN EL PASO COUNTY. THE SMOKE COULD GENERATE ILS VISIBILITIES AND CEILINGS AT APA AND DIA AIRPORT FOR MUCH OF THE NIGHT. && .HYDROLOGY...A FEW STORMS MOVING OVER THE MOUNTAINS AND FRONT RANGE FOOTHILLS THIS AFTERNOON WILL HAVE THE POTENTIAL TO PRODUCE UP TO A QUARTER INCH OF RAIN IN UNDER 35 MINUTES. AT THIS TIME...DUE TO THE RELATIVE FAST MOVEMENT OF THESE STORM CELLS... FLASH FLOODING IS NOT ANTICIPATED. && .PREV DISCUSSION... /ISSUED 334 AM MDT WED JUN 27 2012/ SHORT TERM...MOISTURE PLUME COMING UP THE BACK SIDE OF THE RIDGE PRODUCING A NICE BATCH OF SHOWERS OVER WESTERN COLORADO EARLY THIS MORNING. THIS AREA WILL ROTATE ACROSS NORTH CENTRAL COLORADO DURING THE DAY. CLOUD COVER MAY INITIALLY SUPPRESS CONVECTION THIS MORNING...THOUGH A FEW WEAK SHOWERS ARE STILL EXPECTED. HOWEVER WITH DIURNAL HEATING WE SHOULD EVENTUALLY GENERATE THE SCATTERED THUNDERSTORMS WE HAVE IN THE FORECAST THIS AFTERNOON. I WILL GO AHEAD AND RAISE POPS IN THE MOUNTAINS WHERE THE LOW LEVEL DRYNESS IS NOT A FACTOR. STORMS IN THE MOUNTAINS SHOULD GENERALLY PRODUCE RAIN THOUGH ENOUGH EVAPORATION FOR GUSTY WINDS AS WELL. WEAK COLD FRONT HAS BEEN TAKING ITS TIME PUSHING SOUTH THROUGH WYOMING. PRESSURE SURGE HAS PUSHED OUT AHEAD OF THE WIND SHIFT NOW...SO THE FRONT CONTINUES TO WEAKEN. WE MAY HAVE A TWO STAGE WIND SHIFT AS N-NW WINDS PUSH SOUTH THIS MORNING AHEAD OF THE DEEPER SURGE WITH MORE OF AN EASTERLY COMPONENT. HRRR MODEL CONTINUES TO INSIST ON A SHIFT TO NE WINDS IN THE DENVER AREA AS EARLY AS 15Z...BUT CURRENT OBS SHOW A NWLY PUSH JUST INTO THE BLACK HILLS...AND NO RESPONSE YET IN CENTRAL WYOMING. FOR NOW PLANNING ON GOING MORE W-NW LATER THIS MORNING FROM MIXING...MAY BE MORE NLY IF THE LEAD RIPPLE IS STRONG ENOUGH...THEN THE MAIN WIND SHIFT ACROSS THE AREA IN THE EARLY AFTERNOON. WE WILL HAVE SOME CLOUD COVER OVER THE NW PART OF THE AREA...WHILE THE SE PART SHOULD WARM VERY WELL THIS MORNING. WITH THE FRONT BEING MORE OF A WIND SHIFT THAN A REAL COLD FRONT...THE COOLER TEMPS TODAY WILL BE JUST AS MUCH FROM THE MOISTENING AS COLD ADVECTION. CURRENT FORECAST STILL PRETTY HOT AND LOOKS REASONABLE...THERE COULD BE SOME COOLING FROM ADVECTION/EVAPORATION LATER IN THE AFTERNOON. CONVECTION OVER THE PLAINS SHOULD BE MORE THAN YESTERDAY...BUT STILL HIGH BASED WITH GUSTY WINDS POSSIBLE. CLOUDS OVERNIGHT WILL KEEP TEMPERATURES WARM AGAIN...DO NOT SEE ANY CHANGES NEEDED AT THIS TIME. LONG TERM...LITTLE ADJUSTMENT IN THE LONG TERM. A BROAD RIDGE OF HIGH PRESSURE WILL STRETCH ACROSS THE SOUTHERN UNITED STATES WITH A GENERALLY WEAK WEST TO SOUTHWESTERLY FLOW ALOFT OVER THE CWFA. ON THURSDAY AND FRIDAY AFTERNOON AND EVENING...THE NAM12 FORECAST SOUNDINGS SHOW SUFFICIENT WITH CAPES RANGING FM 500-800 J/KG. INVERTED-V PROFILES WITH PW GENERALLY GREATER THAN 0.50 INCHES. LIGHTNING AND GUSTY OUTFLOW WINDS THE PRIMARY PRODUCTS OF THE STORMS BUT STILL ENOUGH MOISTURE FOR BRIEF LIGHT TO MODERATE SHOWERS. TEMPERATURES WILL QUITE HOT...BUT DO NOT ANTICIPATED THEY WILL EXCEED THE CENTURY MARK IN DENVER BUT THEY MAY GET CLOSE BY THE WEEKEND. THE AMS DOES LOOK EVEN DRIER OVER THE WEEKEND SO WILL CONFINE ANY POTENTIAL TSTMS TO THE HIGHER TERRAIN AT THAT TIME. A COLD FRONT MAY SHAVE A FEW DEGREES OF THE HIGH ON TUESDAY AS ANOTHER UPPER TROUGH PASSES TO THE NORTH OF COLORADO. AVIATION...EXPECT WINDS TO SHIFT TO A NORTHERLY DIRECTION BETWEEN 18Z AND 21Z...POSSIBLY PRECEDED BY A PERIOD OF LIGHT NW WINDS. SCATTERED THUNDERSTORMS EXPECTED IN THE LATE AFTERNOON AND EVENING. VARIABLE WINDS WITH GUSTS OF 30-40 KNOTS ARE POSSIBLE WITH THE THUNDERSTORMS. SOME IMPACT FROM WILDFIRE SMOKE IS POSSIBLE...BUT CONDITIONS ARE EXPECTED TO REMAIN VFR AT THE DENVER AREA AIRPORTS. FIRE WEATHER...INCREASED MOISTURE TODAY WILL LEAD TO SLIGHTLY COOLER TEMPERATURES AND INCREASED THUNDERSTORM ACTIVITY...ESPECIALLY OVER THE MOUNTAINS THIS AFTERNOON. OVER THE MOUNTAINS THE STORMS WILL GENERALLY PRODUCE RAIN...BUT GUSTY WINDS ARE STILL POSSIBLE. OVER THE PLAINS THE ACTIVITY WILL BE MORE LIMITED...WITH SOME DRY LIGHTNING STILL POSSIBLE ALONG WITH WIND GUSTS IN THE 30-50 MPH RANGE WITH SOME OF THE STORMS. HYDROLOGY...BRIEF HEAVY RAIN IS POSSIBLE WITH THE STRONGEST STORMS TODAY...BUT IN GENERAL RAINFALL IS STILL EXPECTED TO BE LIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ214>216. && $$ SHORT TERM...BAKER/GIMMESTAD LONG TERM....COOPER AVIATION...BAKER/GIMMESTAD
AREA FORECAST DISCUSSION
NWS DENVER CO
334 AM MDT WED JUN 27 2012 .SHORT TERM...MOISTURE PLUME COMING UP THE BACK SIDE OF THE RIDGE PRODUCING A NICE BATCH OF SHOWERS OVER WESTERN COLORADO EARLY THIS MORNING. THIS AREA WILL ROTATE ACROSS NORTH CENTRAL COLORADO DURING THE DAY. CLOUD COVER MAY INITIALLY SUPPRESS CONVECTION THIS MORNING...THOUGH A FEW WEAK SHOWERS ARE STILL EXPECTED. HOWEVER WITH DIURNAL HEATING WE SHOULD EVENTUALLY GENERATE THE SCATTERED THUNDERSTORMS WE HAVE IN THE FORECAST THIS AFTERNOON. I WILL GO AHEAD AND RAISE POPS IN THE MOUNTAINS WHERE THE LOW LEVEL DRYNESS IS NOT A FACTOR. STORMS IN THE MOUNTAINS SHOULD GENERALLY PRODUCE RAIN THOUGH ENOUGH EVAPORATION FOR GUSTY WINDS AS WELL. WEAK COLD FRONT HAS BEEN TAKING ITS TIME PUSHING SOUTH THROUGH WYOMING. PRESSURE SURGE HAS PUSHED OUT AHEAD OF THE WIND SHIFT NOW...SO THE FRONT CONTINUES TO WEAKEN. WE MAY HAVE A TWO STAGE WIND SHIFT AS N-NW WINDS PUSH SOUTH THIS MORNING AHEAD OF THE DEEPER SURGE WITH MORE OF AN EASTERLY COMPONENT. HRRR MODEL CONTINUES TO INSIST ON A SHIFT TO NE WINDS IN THE DENVER AREA AS EARLY AS 15Z...BUT CURRENT OBS SHOW A NWLY PUSH JUST INTO THE BLACK HILLS...AND NO RESPONSE YET IN CENTRAL WYOMING. FOR NOW PLANNING ON GOING MORE W-NW LATER THIS MORNING FROM MIXING...MAY BE MORE NLY IF THE LEAD RIPPLE IS STRONG ENOUGH...THEN THE MAIN WIND SHIFT ACROSS THE AREA IN THE EARLY AFTERNOON. WE WILL HAVE SOME CLOUD COVER OVER THE NW PART OF THE AREA...WHILE THE SE PART SHOULD WARM VERY WELL THIS MORNING. WITH THE FRONT BEING MORE OF A WIND SHIFT THAN A REAL COLD FRONT...THE COOLER TEMPS TODAY WILL BE JUST AS MUCH FROM THE MOISTENING AS COLD ADVECTION. CURRENT FORECAST STILL PRETTY HOT AND LOOKS REASONABLE...THERE COULD BE SOME COOLING FROM ADVECTION/EVAPORATION LATER IN THE AFTERNOON. CONVECTION OVER THE PLAINS SHOULD BE MORE THAN YESTERDAY...BUT STILL HIGH BASED WITH GUSTY WINDS POSSIBLE. CLOUDS OVERNIGHT WILL KEEP TEMPERATURES WARM AGAIN...DO NOT SEE ANY CHANGES NEEDED AT THIS TIME. .LONG TERM...LITTLE ADJUSTMENT IN THE LONG TERM. A BROAD RIDGE OF HIGH PRESSURE WILL STRETCH ACROSS THE SOUTHERN UNITED STATES WITH A GENERALLY WEAK WEST TO SOUTHWESTERLY FLOW ALOFT OVER THE CWFA. ON THURSDAY AND FRIDAY AFTERNOON AND EVENING...THE NAM12 FORECAST SOUNDINGS SHOW SUFFICIENT WITH CAPES RANGING FM 500-800 J/KG. INVERTED-V PROFILES WITH PW GENERALLY GREATER THAN 0.50 INCHES. LIGHTNING AND GUSTY OUTFLOW WINDS THE PRIMARY PRODUCTS OF THE STORMS BUT STILL ENOUGH MOISTURE FOR BRIEF LIGHT TO MODERATE SHOWERS. TEMPERATURES WILL QUITE HOT...BUT DO NOT ANTICIPATED THEY WILL EXCEED THE CENTURY MARK IN DENVER BUT THEY MAY GET CLOSE BY THE WEEKEND. THE AMS DOES LOOK EVEN DRIER OVER THE WEEKEND SO WILL CONFINE ANY POTENTIAL TSTMS TO THE HIGHER TERRAIN AT THAT TIME. A COLD FRONT MAY SHAVE A FEW DEGREES OF THE HIGH ON TUESDAY AS ANOTHER UPPER TROUGH PASSES TO THE NORTH OF COLORADO. && .AVIATION...EXPECT WINDS TO SHIFT TO A NORTHERLY DIRECTION BETWEEN 18Z AND 21Z...POSSIBLY PRECEDED BY A PERIOD OF LIGHT NW WINDS. SCATTERED THUNDERSTORMS EXPECTED IN THE LATE AFTERNOON AND EVENING. VARIABLE WINDS WITH GUSTS OF 30-40 KNOTS ARE POSSIBLE WITH THE THUNDERSTORMS. SOME IMPACT FROM WILDFIRE SMOKE IS POSSIBLE...BUT CONDITIONS ARE EXPECTED TO REMAIN VFR AT THE DENVER AREA AIRPORTS. && .FIRE WEATHER...INCREASED MOISTURE TODAY WILL LEAD TO SLIGHTLY COOLER TEMPERATURES AND INCREASED THUNDERSTORM ACTIVITY...ESPECIALLY OVER THE MOUNTAINS THIS AFTERNOON. OVER THE MOUNTAINS THE STORMS WILL GENERALLY PRODUCE RAIN...BUT GUSTY WINDS ARE STILL POSSIBLE. OVER THE PLAINS THE ACTIVITY WILL BE MORE LIMITED...WITH SOME DRY LIGHTNING STILL POSSIBLE ALONG WITH WIND GUSTS IN THE 30-50 MPH RANGE WITH SOME OF THE STORMS. && .HYDROLOGY...BRIEF HEAVY RAIN IS POSSIBLE WITH THE STRONGEST STORMS TODAY...BUT IN GENERAL RAINFALL IS STILL EXPECTED TO BE LIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GIMMESTAD LONG TERM....COOPER AVIATION...GIMMESTAD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
ISSUED BY NATIONAL WEATHER SERVICE UPTON NY 1140 AM EDT WED JUN 27 2012 .SYNOPSIS... LOW PRESSURE WILL REMAIN NEARLY STATIONARY ACROSS MAINE THROUGH TODAY BEFORE GRADUALLY WEAKENING AND LIFTING NE TONIGHT INTO THURSDAY. INCREASING HEAT AND HUMIDITY WILL RETURN FRIDAY THROUGH THE WEEKEND WITH SLIGHTLY COOLER WEATHER EARLY NEXT WEEK. && .NEAR TERM /UNTIL 9 PM THIS EVENING/... LATE MORNING UPDATE...10Z AND 12Z RUNS OF THE HRRR MODEL WERE CONSISTENT IN DEVELOPING A BKN LINE OF CONVECTION DEVELOPING OVER NRN NEW ENGLAND AND DRIFTING SE INTO S NH AND NE/CENTRAL MA LATE THIS AFTERNOON AND EARLY THIS EVENING...WITH ADDITIONAL MID TO LATE AFTN DEVELOPMENT IN THOSE SAME AREAS AS WELL. EXTENDED EARLIER FCST OF SCT COVERAGE A LITTLE FARTHER SOUTH AND ALSO LATER...INTO EARLY THIS EVENING. RAP FCST SOUNDINGS INDICATE MARGINAL BUT DEEP ENOUGH INSTABILITY TO WARRANT MENTION OF ISOLD THUNDER FOR STRONGER CELLS THAT DEVELOP. FROM ORIGINAL DISCUSSION...VERTICALLY STACKED LOW PRESSURE WILL REMAIN NEARLY STATIONARY ACROSS MAINE TODAY WITH DEEP CYCLONIC FLOW ACROSS SNE. CROSS SECTIONS INDICATE LOTS OF MOISTURE IN THE COLUMN WHICH WILL RESULT IN NUMEROUS CU/AC...WITH MOST CLOUD COVER NE HALF SNE WHERE MOISTURE IS GREATEST...WHILE MOST SUNSHINE WILL BE ACROSS SW ZONES. WEAK SHORTWAVE ROTATING S AROUND THE MID LEVEL LOW MAY PROVIDE A FOCUS FOR ANOTHER ROUND OF SCT SHOWERS REDEVELOPING THIS AFTERNOON...MAINLY FROM S NH THROUGH CENTRAL AND E MA AND HAVE CHC POPS. HOWEVER...EXPECT AREAL COVERAGE WILL BE SOMEWHAT LIMITED AND NO THUNDER AS MID LEVEL TEMPS ARE WARMING LEADING TO MEAGER MID LAPSE RATES. TEMPS...WE LEANED TOWARD COOLER BIAS CORRECTED MOS GUIDANCE DUE TO EXPECTED CLOUD COVER...BUT TEMPS WILL RECOVER BACK TO NEAR SEASONABLE NORMALS GIVEN MODERATING LOW LEVEL TEMPS. WARMEST READINGS INTO THE LOWER 80S WILL BE ACROSS THE LOWER CT VALLEY. && .SHORT TERM /9 PM THIS EVENING THROUGH 6 PM THURSDAY/... TONIGHT... LOW PROB OF A FEW LINGERING SHOWERS NE ZONES BUT SHOWERS SHOULD DISSIPATE WITH LOSS OF DIURNAL HEATING. OTHERWISE EXPECT CLEARING SKIES SW ZONES AND PT-MOCLDY FURTHER NE. USED A BLEND OF MAV/MET GUIDANCE FOR MIN TEMPS. THURSDAY... VERTICALLY STACKED LOW WILL GRADUALLY WEAKEN AND LIFT NE INTO THE MARITIMES...WITH WARM FRONT APPROACHING FROM THE WEST. PT-MOSUNNY SKIES WILL PREVAIL ACROSS THE REGION. WITH CONTINUED MID LEVEL WARMING MOVING IN FROM THE WEST...MAINLY DRY WEATHER IS EXPECTED ALTHOUGH STILL CANT RULE OUT AN ISOLD SHOWER NE ZONES WHERE MID LEVEL TEMPS ARE COOLEST. 850 MB TEMPS START OUT AROUND 10-12C AND WARM TO 14-16C BY THE END OF THE DAY WITH WESTERLY FLOW. SO TEMPS SHOULD SOAR INTO THE 80S FOR MUCH OF THE REGION...WARMEST CT VALLEY. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... HIGHLIGHTS... * UNSETTLED WEATHER WILL CONTINUE THROUGH THE PERIOD * WARMER WEATHER ARRIVES LATE IN THE WEEK AND INTO THE WEEKEND OVERVIEW... DECENT AGREEMENT AMONGST THE MODELS WITH THIS FORECAST. THE UPPER LEVEL PATTERN BECOMES ZONAL FRIDAY AND REMAINS THAT WAY THROUGH THE WEEKEND. EARLY NEXT WEEK...THERE START TO BE SOME DISCREPANCIES IN THE MODELS WITH THE HANDLING OF A WEAK UPPER LEVEL TROUGH THAT MOVES OVER SOUTHERN NEW ENGLAND. THESE DIFFERENCES RELATE TO THE TIMING OF THE TROUGHS APPROACH AND THEN DEPARTURE FROM THE REGION. THIS WILL AFFECT WHEN SOMEWHAT COOLER TEMPERATURES MOVE INTO THE REGION WITH THE ASSOCIATED LOW PRESSURE SYSTEM AND COLD FRONT. THERE ARE STILL MINOR DISCREPANCIES IN THE FORECAST BUT OVERALL GOOD CONFIDENCE. DETAILS... THURSDAY NIGHT THROUGH THE WEEKEND...WILL SEE A RETURN TO WARMER...MORE HUMID WEATHER AS THE UPPER LOW LIFTS TO THE NORTHEAST AND IS REPLACED BY MORE ZONAL FLOW. WHILE THE PROBABILITY OF SHOWERS WILL GO DOWN A BIT...THERE WILL STILL BE ENOUGH MOISTURE...AND CERTAINLY ENOUGH DIURNAL HEATING FOR AFTERNOON SHOWERS AND THUNDERSTORMS. BEST CHANCES OF STORMS WILL BE ON FRIDAY AND SUNDAY WHEN A COUPLE OF WEAK COLD FRONTS WILL MOVE ACROSS SOUTHERN NEW ENGLAND. TEMPERATURES CLIMB INTO THE MID TO UPPER 80S TO POSSIBLY EVEN THE LOWER 90S DURING THIS TIME. MONDAY...MODELS INDICATE WEAK LOW PRESSURE MOVING THROUGH QUEBEC WILL BRING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND. THIS WILL LIKELY RESULT IN SOME SHOWERS AND THUNDERSTORMS AS WELL AS A BIT OF RELIEF FROM THE WARM TEMPERATURES. TUESDAY...THERE ARE SOME MINOR DISCREPANCIES AT THIS POINT...TO BE EXPECTED AS IT IS DAY 7. UPPER LEVEL TROUGH MOVES OFFSHORE AND WEAK HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW...HIGH CONFIDENCE. MAINLY VFR. SCT SHOWERS AND AN ISOLD TSTM EXPECTED THIS AFTERNOON/EARLY EVENING FROM S NH THROUGH CENTRAL AND NE MA. LOW PROB OF BRIEF MVFR CONDITIONS IN ANY SHOWERS. WEST WIND GUSTS TO 20-25 KT THIS AFTERNOON. KBOS TAF...HIGH CONFIDENCE. LOW PROB OF A BRIEF SHOWER OR ISOLD TSTM THIS AFTERNOON INTO EARLY EVE. WEST WINDS MAY GUST TO 20 KT AT TIMES TODAY. KBDL TAF...HIGH CONFIDENCE. VFR THROUGH THE PERIOD. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... MODERATE CONFIDENCE. MAINLY VFR WITH BRIEF PERIODS OF MVFR IN SCT SHOWERS AND TSTMS. && .MARINE... MODERATE CONFIDENCE. WESTERLY FLOW TODAY AND MAY SEE A FEW GUSTS APPROACHING SCA THRESHOLD OF 25 KT ACROSS S COASTAL WATERS. WNAWAVE AND SWAN GUIDANCE ARE CURRENTLY TOO HIGH ON THE SEAS SO OUR FORECAST CONFIDENCE IN SEAS IS A BIT LOWER...BUT WE OPTED TO KEEP SCA GOING OVER SOUTHERN OUTER WATERS FOR COMBINED POTENTIAL OF 5 FT SEAS AND NEAR 25 KT GUSTS. WINDS AND SEAS SHOULD BE MAINLY BELOW SCA TONIGHT AND THU...BUT IT IS POSSIBLE SCA SEAS COULD LINGER INTO THIS EVENING. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... MODERATE CONFIDENCE. SWELL FROM TROPICAL DEPRESSION DEBBY WILL BEGIN MOVING INTO SOUTHERN NEW ENGLAND WATERS THURSDAY NIGHT INTO FRIDAY...RESULTING IN 5 TO 6 FOOT SEAS ON THE OUTER WATERS. THESE MAY CONTINUE THROUGH SUNDAY. OTHERWISE...PLEASANT BOATING WEATHER MOST OF THE TIME. THERE IS A LOW PROBABILITY OF SHOWERS AND THUNDERSTORMS EACH AFTERNOON. NEAR SHORE WIND GUSTS MAY NEAR 25 KT FOR A BRIEF PERIOD FRIDAY AFTERNOON. OTHERWISE...WINDS WILL REMAIN BELOW 25 KT THROUGHOUT THE PERIOD. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ254>256. && $$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1156 PM EDT THU JUN 28 2012 .SYNOPSIS... A WARM FRONT WILL CROSS OUR AREA FRIDAY MORNING. MEANWHILE, HIGH PRESSURE ACROSS THE SOUTHERN STATES WILL GENERALLY REMAIN IN PLACE THROUGH SUNDAY. A COOL FRONT WILL GRADUALLY SETTLE SOUTHEASTWARD ACROSS THE AREA SATURDAY INTO SUNDAY, HOWEVER IT WILL TEND TO STALL ACROSS THE NORTHERN MID ATLANTIC REGION MONDAY AND TUESDAY. THIS FRONT MAY THEN LIFT NORTHEASTWARD AS A WARM FRONT WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... SHORT TERM UPDATE INCORPORATING LATEST HRRR ALONG WITH THE 00Z WRF-NMMB THERMODYNAMIC PROFILE FOR FINE TUNING, BASICALLY LOOKS LIKE THE THERMODYNAMICS WIN OVER THE KINEMATICS WITH POPS ADJUSTED LOWER TOWARD NYC AND HIER SWRN PART OF OUR CWA. SMALL MCS TAPPING THE STILL WELL IN THE 80S AND UPPER 60S DEW POINTS IN OHIO AND HAS STRENGTHENED. WHILE THERE IS SUSTAINABILITY ALOFT, ITS GOING TO BE OUTRUNNING THE BEST SURFACE BASED INSTABILITY SHORTLY. THE FCST THETA E AND THERMODYNAMIC FEED SUGGEST MORE OF A SHARPER TURN TO THE RIGHT. OTHERWISE DOWN THE ROAD THE HRRR AND NMM INFERRING OUR ENVIRONMENT JUST NOT AS HOSPITABLE HERE. REGARDLESS ENOUGH OF A SHORT WAVE TO KEEP CHANCES GOING, WILL MONITOR THE NEXT COUPLE OF HRS TO SEE IF WE HAVE TO ADD ANY ENHANCED WORDING. TEMPS AND DEW POINTS REMAIN ON OR CLOSE TO SCHEDULE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... TSTMS MOVE OUT TO SEA BY 12 OR 13Z AND THEN THE DANGEROUS HEAT INDICES. FRIDAY WILL FEEL DRAMATICALLY DIFFERENT THAN TODAY AND I THINK BE THE WORST ITS FELT HERE SO FAR THIS SUMMER. NEAR RECORD HEAT...WITHIN 2F OF RECORD POSSIBLE BY 530 PM... TEMPERATURES TO SOAR WELL INTO THE 90S FOR MOST AREAS. DEWPOINTS WELL INTO THE 60S AND PERHAPS LOW 70S FOR SOUTHERN AREAS WILL MAKE FOR A VERY MUGGY DAY. THERE IS SOME CONCERN, HOWEVER, THAT DEWPOINTS MAY MIX OUT AND LOWER SOMEWHAT LATER IN THE AFTERNOON. WE DO HOWEVER EXPECT TO REACH OUR HEAT INDEX CRITERIA, AND THUS, THE EXCESSIVE HEAT WARNING IS MAINTAINED FOR PHILADELPHIA AND ITS SURROUNDING COUNTIES. WE HAVE ALSO ISSUED A HEAT ADVISORY FOR MOST OF THE REMAINDER OF OUR FORECAST AREA WITH THE AFTERNOON PACKAGE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... THE HEAT WAVE THROUGH AT LEAST MIDWEEK FOR A GOOD PART OF THE REGION MAY BE TEMPORARILY INTERRUPTED BY LOCAL CONVECTION AT TIMES. SYNOPTICALLY, AN ELONGATED RIDGE IS FORECAST TO GENERALLY REMAIN IN PLACE FROM THE CENTRAL PLAINS TO THE SOUTHEASTERN UNITED STATES. TO THE NORTH OF THIS, SOME TROUGHING IS MAINTAINED ACROSS EASTERN CANADA WITH THIS FEATURE TRYING TO AMPLIFY SOME ACROSS THE NORTHEAST. THIS SYNOPTIC SETUP RESULTS IN A NORTHWESTERLY FLOW ALOFT ACROSS THE NORTHEAST AND MID ATLANTIC REGION. THEREFORE, SOME EMBEDDED WEAKER SHORT WAVES AND SURFACE FRONTAL BOUNDARIES WILL BE MOVING ACROSS THE AREA. OUR SENSIBLE WEATHER WILL REMAIN HOT AND GENERALLY HUMID THROUGH SUNDAY, BUT THEN THE TROUGH AMPLIFIES SOME AND THIS SHOULD KNOCK DOWN THE EXCESSIVE HEAT. A FRONTAL BOUNDARY LURKING AROUND THE NORTHERN MID ATLANTIC REGION MAY TRY AND LIFT NORTHEASTWARD SOME WEDNESDAY INTO THURSDAY. THE FORECAST CHALLENGES INCLUDE THE CONTINUATION OF THE HEAT FOR A TIME, THE DEW POINTS, AND CONVECTIVE CHANCES. WE GENERALLY TOOK A MODEL BLEND FRIDAY NIGHT INTO SUNDAY, THEN SWITCHED TO HPC GUIDANCE THEREAFTER WITH SOME TWEAKS BASED ON ADDITIONAL COLLABORATION. HPC WENT WITH THE GFS ENSEMBLE MEANS SUNDAY NIGHT THROUGH TUESDAY THEN A GFS/ECMWF ENSEMBLE MEANS BLEND WEDNESDAY AND THURSDAY. FOR FRIDAY NIGHT THROUGH SUNDAY, THE HEAT WILL BE ON DURING THIS TIME FRAME. THERE IS STILL A CONCERN THAT THE SURFACE DEW POINTS ARE ABLE TO MIX OUT SOME SATURDAY AND SUNDAY AFTERNOONS AS THE BOUNDARY LAYER WILL BE RATHER HOT WITH DRIER AIR ABOVE. THERE ARE SOME QUESTIONS WHICH INCLUDE WHERE A WEAK SURFACE BOUNDARY BECOMES ESTABLISHED AND CONVECTIVE CHCS. THE TEMPERATURE FORECAST AT 925 MB ARE AROUND +25C, WITH THE MAIN HEAT CORE FROM ABOUT VIRGINIA ON SOUTH AND WESTWARD. THE LOW-LEVEL FLOW LOOKS TO SHIFT MORE FROM THE SOUTHWEST AT TIMES, AND THIS TYPICALLY WOULD FAVOR HIGHER DEW POINTS. AN EXAMINATION OF SOME FORECAST SOUNDINGS SHOW AS THE BOUNDARY LAYER BECOMES RATHER HOT, ENOUGH MIXING FROM ABOVE OCCURS TO LOWER THE SURFACE DEW POINTS. WE DO ANTICIPATE THE DEW POINTS TO MIX OUT AT LEAST SOME, AND THIS WILL TEND TO KEEP THE HEAT INDICES MORE IN CHECK. DESPITE THIS, IT WILL STILL BE RATHER HOT. OUR DEW POINT FORECAST IS MORE OF A MODEL MOS BLEND AS THIS MESHES BETTER WITH REGIONAL SOUNDINGS. REGARDING HEADLINES, THE WARNING WILL CONTINUE THROUGH 00Z MONDAY FOR THE PHILADELPHIA METRO AREA AS THE HEAT INDEX CRITERIA IS LOWER. ELSEWHERE, WE DECIDED TO HOLD OFF ON A HEAT ADVISORY AS FORECAST DEW POINTS ARE KEEPING THE HEAT INDICES UNDER CRITERIA. THIS WILL BE REVISITED IN LATER FORECASTS. THE FLOW AROUND 925 MB IS FORECAST TO BE GENERALLY WESTERLY AT ABOUT 10 TO 15 KNOTS, THEREFORE ANY SEA BREEZE SHOULD STAY CLOSE TO THE COAST. REGARDING THE CONVECTIVE POTENTIAL, GIVEN THE FLOW IN THE MID AND UPPER LEVELS IN COMBINATION WITH A HOT AIRMASS, THERE COULD BE A TENDENCY FOR SOME CAPPING ESPECIALLY AT NIGHT. ANY IMPULSES EMBEDDED WITHIN THIS FLOW REGION AND ALONG THE NORTHERN PERIPHERY OF THE ELONGATED RIDGE SHOULD BE ABLE TO INITIATE SOME CONVECTION WITH DECENT INSTABILITY IN PLACE. THE GUIDANCE CONTINUES TO HINT AT SOME CONVECTION ARRIVING SATURDAY INTO SUNDAY, HOWEVER IT IS NOT CLEAR IF THIS IS COMPLETELY SURFACE BASED AS THE MCS THE 12Z NAM SUGGESTS LOOKS MORE ELEVATED BASED ON ITS FORECAST SOUNDINGS SATURDAY NIGHT. THE TIMING/STRENGTH OF ANY IMPULSE ALONG WITH A LINGERING SURFACE BOUNDARY AND HOW IT MAY PLAY A ROLE CARRIES SOME UNCERTAINTY, AND ANY MORE ORGANIZED CONVECTION WILL ALSO HAVE AN IMPACT ON THE HEAT /I.E. DEBRIS CLOUDINESS AND DEW POINT INFLUENCES/. THE GFS HAS HAD A TENDENCY TO BE MORE AGGRESSIVE WITH THE HIGHER SURFACE DEW POINTS /MOS IS LOWER/, THEREFORE THIS MAY HELP TO EXPLAIN MORE CONVECTIVE OPPORTUNITIES INDICATED BY THIS MODEL AT TIMES. FOR NOW, SOME SLIGHT CHC TO LOW CHC POPS WERE CARRIED DURING PORTIONS OF THIS TIME FRAME. FOR MONDAY AND TUESDAY, A TROUGH ACROSS EASTERN CANADA AMPLIFIES A BIT INTO THE NORTHEAST. THIS ALLOWS HEIGHTS TO START LOWERING AND THE EXCESSIVE HEAT SHOULD BACK DOWN SOME. THIS WILL ARRIVE BY A COOL FRONT MONDAY THAT MAY ACTUALLY WEAKEN TO A SURFACE TROUGH. THERE COULD BE SOME CONVECTION WITH THIS AS WELL, ESPECIALLY DURING PEAK HEATING. OVERALL WITHIN MORE OF A CYCLONIC FLOW ALOFT, THE MODEL GUIDANCE IS NOT ALL THAT ROBUST WITH LARGE SCALE LIFT. THE GFS SHOWS MORE AMPLIFICATION WHICH MAY LEAD TO MORE ORGANIZED CONVECTION MONDAY, HOWEVER FOR NOW WE KEPT POPS NO HIGHER THAN SLIGHT CHC. SINCE TEMPERATURES ARE FORECAST TO DROP BACK SOME, THE HEAT RELATED HEADLINES WERE NOT EXTENDED. FOR WEDNESDAY AND THURSDAY, A SURFACE LOW IS FORECAST TO TRACK ACROSS THE GREAT LAKES WITH A WARM FRONT DRAPED TO THE SOUTHEAST. THERE IS A RATHER HOT AIRMASS FORECAST TO BE SITTING SOUTHWEST OF THIS WARM FRONT AND IT MAY BE HELD THERE AS JUST ENOUGH TROUGHING HOLDS ACROSS THE NORTHEAST. DESPITE THIS, THE WARM FRONT LOOKS TO LIFT ACROSS OUR AREA LATER WEDNESDAY INTO THURSDAY AS THE FLOW BACKS TO THE SOUTHWEST. SINCE THERE COULD BE SOME TIMING ISSUES WITH THE WARM FRONT, WE OPTED TO LEAN CLOSER TO HPC GUIDANCE WHICH RESULTS IN FORECAST HIGHS GENERALLY IN THE UPPER 80S TO LOWER 90S. THE POPS ARE UNDER SLIGHT CHC WEDNESDAY THEN SLIGHT CHC TO LOW CHC THURSDAY. && .AVIATION /04Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...VFR SCT AOA 7000 FT WITH LIGHT S-SW WIND. A 2 HR WINDOW OF A SCT-BKN BAND OF TSTMS IN THE 07Z-12Z TIME FRAME...ISOLATED STRONG STORM POSSIBLE WITH HAIL AND GUST OUTFLOWS PUNCHING SEWD THRU THE AREA. FRIDAY...VFR WITH ANY CLOUDS AOA 4000 FT DURING MORNING-MIDDAY PROBABLY DISSIPATING DURING THE AFTERNOON AS DRIER AIR ARRIVES. WIND BECOMING WNW AND GUSTY TO NEAR 20 KTS. OUTLOOK... FRIDAY NIGHT THROUGH SUNDAY NIGHT...VFR WITH THE EXCEPTION OF POSSIBLE LOCAL SUB-VFR DUE TO FOG/HAZE DURING THE EARLY MORNINGS. A COUPLE OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE, HOWEVER THERE IS LOWER CONFIDENCE WITH THE TIMING AND COVERAGE. GENERALLY LIGHT AND VARIABLE WINDS AT NIGHT, THEN WESTERLY NEAR 10 KNOTS DURING THE DAY. THE WINDS COULD SHIFT MORE SOUTHERLY LOCALLY IN THE AFTERNOON AND EARLY EVENING DUE TO ANY MARINE INFLUENCE. MONDAY AND TUESDAY...VFR, ALTHOUGH THERE STILL REMAINS THE CHANCE FOR A FEW SHOWERS AND THUNDERSTORMS. WHILE CONFIDENCE IS ON THE LOWER SIDE REGARDING TIMING AND COVERAGE, IT APPEARS THE AFTERNOON AND EVENING HOURS HAVE A BETTER CHANCE OF THIS OCCURRING. WEST TO NORTHWEST WINDS NEAR 10 KNOTS MAY SHIFT TO THE SOUTHWEST TUESDAY. && .MARINE... CONDITIONS ON OUR WATERS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA TONIGHT AND THROUGH FRIDAY. WINDS WILL PRIMARILY BE SOUTHWESTERLY DURING THE PERIOD. OUTLOOK... THE CONDITIONS ARE ANTICIPATED TO BE MOSTLY BELOW SMALL CRAFT ADVISORY CRITERIA FRIDAY NIGHT THROUGH TUESDAY. A WARM FRONT SHOULD LIFT THROUGH THE AREA FRIDAY MORNING, THEN A COUPLE OF COOL FRONTS SHIFT THROUGH THE REGION UNDER A NORTHWESTERLY FLOW ALOFT. THESE BOUNDARIES GENERALLY LOOK ON THE WEAKER SIDE, HOWEVER A WESTERLY WIND SHOULD SHIFT TO SOUTHWESTERLY AT TIMES ESPECIALLY AS THE AIRMASS WILL BE HOT. AS A RESULT OF THE HOT AIRMASS, THE WINDS MAY LOCALLY INCREASE SOME DURING THE AFTERNOON AND EVENING HOURS. THE SEAS ARE ANTICIPATED TO REMAIN AT OR BELOW 4 FEET. && .TIDES/COASTAL FLOODING... GFS ETSS STILL MODELS POTENTIAL MINOR COASTAL FLOOD EPISODES HERE WITH THE EVENING TIDE CYCLES BEGINNING SUNDAY OR MONDAY AND CONTG THRU AT LEAST JULY 3 FULL MOON WHEN ASTRO TIDE IS WITHIN .3 FT OF THE MINOR TIDAL INUNDATION THRESHOLD. && .RIP CURRENTS... WHILE THE RISK OF DANGEROUS RIP CURRENTS APPEARS LOW FOR THE NEXT SEVERAL DAYS, THERE SHOULD BE SOME ENHANCEMENT OF THE RISK FOR RIP CURRENTS. FIRST ASSOCIATED WITH AN INCREASING S SWELL TO 3 FEET WITH A 8 SECOND PERIOD FRIDAY THAT CONTINUES INTO SATURDAY...ESPECIALLY IF THE WIND AT BUOY 009 IS 180 OR 190 DEGREES, AND THEN WITH AN INCREASINGLY LARGE RATE OF CHANGE IN TIDES AS WE MOVE TOWARD THE FULL MOON EARLY NEXT WEEK. && .CLIMATE... TEMPERATURES ARE EXPECTED TO REACH WELL INTO THE 90S FRIDAY THROUGH SUNDAY. BELOW ARE THE RECORD HIGH TEMPERATURES AND MOST RECENT YEAR OF OCCURRENCE FOR JUNE 29 THROUGH JULY 1 FOR OUR EIGHT CLIMATE SITES. JUNE 29 JUNE 30 JULY 1 PHL 102 - 1934 100 - 1964 102 - 1901 ACY 98 - 1991 98 - 1991 99 - 1968 ILG 98 - 1959 98 - 1964 97 - 1963 ABE 99 - 1934 97 - 1964 97 - 1963 TTN 100 - 1934 98 - 1964 98 - 1945 RDG 99 - 1943 98 - 1964 101 - 1901 GED 99 - 1969 101 - 1959 98 - 1964 MPO 89 - 1944 90 - 1964 88 - 1968 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR PAZ060>062. EXCESSIVE HEAT WARNING FROM NOON FRIDAY TO 8 PM EDT SUNDAY FOR PAZ067>071. NJ...HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR NJZ007>010-012- 013-016-020>023-027. EXCESSIVE HEAT WARNING FROM NOON FRIDAY TO 8 PM EDT SUNDAY FOR NJZ015-017>019. DE...HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR DEZ002-003. EXCESSIVE HEAT WARNING FROM NOON FRIDAY TO 8 PM EDT SUNDAY FOR DEZ001. MD...HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR MDZ008-012-015- 019-020. MARINE...NONE. && $$ SYNOPSIS...GORSE NEAR TERM...GIGI SHORT TERM...DRAG/KLINE LONG TERM...GORSE AVIATION...DRAG/GORSE/KLINE MARINE...DRAG/GORSE/KLINE TIDES/COASTAL FLOODING... RIP CURRENTS... CLIMATE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
124 AM EDT WED JUN 27 2012 .SYNOPSIS... A COLD FRONT WILL STALL JUST SOUTHEAST OF THE AREA TONIGHT. TROPICAL CYCLONE DEBBY IS FORECAST TO MOVE EAST OFF THE NORTHERN FLORIDA COAST DURING MID WEEK THEN PASS INTO THE ATLANTIC WELL SOUTH AND EAST OF THE AREA THROUGH LATE WEEK. A STRONG RIDGE OF HIGH PRESSURE WILL THEN OVERSPREAD THE REGION LATE IN THE WEEK INTO EARLY NEXT WEEK...RESULTING IN HOT WEATHER ACROSS THE AREA. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... TROPICAL DEPRESSION DEBBY IS MEANDERING ACROSS CENTRAL FLORIDA EARLY THIS MORNING. ASSOCIATED CLOUD COVER IS MOVING QUICKLY OFFSHORE AS DRY AIR WORKS IN BEHIND ITS CIRCULATION AND A MID- LEVEL SHEAR AXIS SHIFTS FARTHER OFFSHORE. ADJUSTED SKY GRIDS TO SHOW CLEAR TO MOSTLY CLEAR SKIES DOMINATING THROUGH SUNRISE. NO OTHER CHANGES WERE MADE. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... WEDNESDAY...TROPICAL CYCLONE DEBBY IS FORECAST TO SHIFT ACROSS THE NORTHERN FLORIDA PENINSULA. AS THIS OCCURS...A DEFORMATION ZONE EXTENDING NORTHEAST OF DEBBY AND A SLOW MOVING COLD FRONT WILL CONTINUE TO GRADUALLY SHIFT FARTHER INTO THE ATLANTIC AS HIGH PRESSURE AND DRIER AIR OVERSPREAD THE AREA FROM THE NORTH. SOME SHOWERS WILL BE POSSIBLE ALONG THE SOUTHEAST GEORGIA COAST...MAINLY IN THE MORNING...BUT THE BULK OF CONVECTION SHOULD BE OFFSHORE AND MOVING FARTHER FROM THE AREA AS THE DAY PROGRESSES. THE CIRRUS SHIELD SHOULD ALSO SHIFT EAST THROUGH THE DAY...RESULTING IN A GOOD AMOUNT OF SUNSHINE ACROSS THE AREA...EXCEPT PERHAPS ALONG THE SOUTHEAST GEORGIA COAST. DESPITE THE BREAKS OF SUNSHINE...A NORTHEAST FLOW WILL HOLD TEMPERATURES TO HIGHS IN THE UPPER 80S TO NEAR 90 AWAY FROM THE COAST. BREEZY CONDITIONS ARE ALSO EXPECTED ON WEDNESDAY...DUE TO A TIGHT SURFACE PRESSURE GRADIENT BETWEEN DEBBY AND THE BUILDING HIGH TO THE NORTH. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MEDIUM RANGE GUIDANCE AND THE OFFICIAL NHC FORECAST ARE GENERALLY IN GOOD AGREEMENT SHOWING TROPICAL CYCLONE DEBBY PASSING WELL SOUTH AND EAST OF THE REGION. RAIN FREE CONDITIONS AND MAINLY CLEAR SKIES ARE EXPECTED ACROSS THE AREA. MODERATING TEMPERATURES WILL HAVE LOWS WEDNESDAY NIGHT IN THE LOW TO MID 60S...HIGHS THURSDAY IN THE LOW TO MID 90S AND LOWS THURSDAY NIGHT AROUND 70. FRIDAY...AN IMPRESSIVE UPPER LEVEL RIDGE WILL BEGIN TO EXTEND EASTWARD INTO THE REGION. A WEAK LEE SIDE TROUGH SHOULD RESULT IN A SOUTHERLY FLOW ACROSS THE AREA...BUT THE MID LEVEL FLOW WILL SHIFT NORTHWEST/DOWNSLOPE...RESULTING IN SIGNIFICANT WARMING ACROSS THE AREA. HIGHS ON FRIDAY ARE FORECAST TO BE AROUND 100 WELL INLAND TO THE UPPER 90S CLOSER TO THE COAST BUT WELL INLAND OF THE COOLER BEACHES. HEAT INDEX VALUES ARE EXPECTED TO BE EASILY IN THE 105 TO 110 DEGREE RANGE...AND HEAT ADVISORIES WILL VERY LIKELY BE NEEDED. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... SFC HIGH PRESSURE AND A LARGE MID LVL RIDGE WILL EXPAND OVER THE SOUTHEAST THROUGH THIS WEEKEND. CONDITIONS WILL BECOME VERY HOT AND HUMID OVER THE WEEKEND AS MID LVL RIDGING BECOMES CENTERED OVER THE SOUTHEAST WHILE DEW POINTS INCREASE TO THE MID 70S. WE WILL SEE SOME OF THE WARMEST TEMPS SO FAR THIS SEASON...WITH HIGHS AROUND 100 IN MOST AREAS AWAY FROM THE COAST. THESE COULD EVEN BE A BIT CONSERVATIVE GIVEN 850 MB TEMPERATURES NEAR 24C...AND FORECAST THICKNESS VALUES SUPPORT HIGHS CLOSER TO 105 IN MANY AREAS. USING CURRENT FORECAST TEMPS ALONG WITH MID 70 DEW POINTS PRODUCE HEAT HEAT INDICES BETWEEN 105 TO 114 DEGREES EACH AFTERNOON...CERTAINLY AT HEAT ADVISORY CRITERIA LEVELS AND NEAR EXCESSIVE HEAT WARNING VALUES. A FEW LOCATIONS MAY SEE RELIEF FROM THE HEAT EACH AFTERNOON/EVENING WITH SHOWERS AND/OR THUNDERSTORMS THAT DEVELOP NEAR A WEAK TROUGH OVER THE MIDLANDS. HIGH TEMPS WILL LIKELY REMAIN ABOVE CLIMATOLOGY EARLY NEXT WEEK...MID TO UPPER 90S...AS A MORE ZONAL TYPE PATTERN DEVELOPS OVER THE SOUTHEAST. OVERNIGHT LOWS WILL RANGE FROM THE LOW TO MID 70S THROUGH EARLY NEXT WEEK. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... VFR FOR THE NEXT 24 HOURS. COULD SEE A BRIEF PERIOD OF GUSTY WINDS AT BOTH KCHS/KSAV AFTER SUNRISE ONCE THE NOCTURNAL INVERSION BURNS OFF. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS AT THIS TIME. && .MARINE... BUOY AND PILOT BOAT REPORTS INDICATE WINDS REMAIN JUST BELOW GALE WARNING CRITERIA. HAVE OPTED NOT TO HOIST A GALE WARNING GIVEN THESE REPORTS...ALTHOUGH LATEST RUC OUTPUT SUGGESTS WINDS MAY INCREASE A BIT MORE THROUGH SUNRISE IN RESPONSE TO A TIGHTENING PRESSURE GRADIENT. WILL WATCH TRENDS CAREFULLY. WW4 OUTPUT RUNNING ABOUT 1 FOOT BEHIND CURRENT OBSERVATIONS. ADJUSTED SEAS PER GOING TRENDS. WEDNESDAY...WILL HAVE ONGOING SMALL CRAFT ADVISORY CONDITIONS OVER ALL WATERS AS A TIGHT SURFACE PRESSURE GRADIENT DEVELOPS BETWEEN TROPICAL CYCLONE DEBBY AND HIGH PRESSURE TO THE NORTH. NORTHEAST WINDS COULD SURGE AS HIGH AS 25-30 KT WITH HIGHER GUSTS...ESPECIALLY IN THE GEORGIA WATERS...BEFORE DIMINISHING A BIT IN THE AFTERNOON. THE FAVORABLE FETCH WILL GENERATE SEAS AS HIGH 5-8 FT ACROSS MOST OF THE WATERS. WEDNESDAY NIGHT...THE SURFACE PRESSURE GRADIENT WILL BEGIN TO WEAKEN...RESULTING IN DIMINISHING WINDS/SEAS THROUGH THE NIGHT. SMALL CRAFT ADVISORIES FOR ALL BUT THE OUTER GEORGIA WATERS SHOULD BE DOWN BY THE END OF THE NIGHT...IF NOT SOONER ACROSS THE SOUTH CAROLINA WATERS AND CHARLESTON HARBOR. THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE HAS IMPROVED FOR LATE WEEK WITH TROPICAL STORM DEBBY EXPECTED TO REMAIN SOUTH OF THE WATERS BEFORE HEADING FURTHER EAST TOWARDS THE GULF STREAM. A FAIR NORTHEAST GRADIENT WIND OF 10-15 KNOTS WILL LAST THROUGH MUCH OF THURSDAY BEFORE WINDS BECOME MORE SOUTH/SOUTHEAST BY FRIDAY. SEAS WILL REMAIN WELL BELOW SMALL CRAFT ADVISORY THRESHOLDS THIS WEEKEND...BETWEEN 1-3 FEET FOR NEARSHORE WATERS AND 2-4 FOR OUTER GEORGIA WATERS. RIP CURRENTS...A STRONG NORTHEAST FLOW AND A CONTINUATION OF SWELL ENERGY WILL RESULT IN A MODERATE RISK OF RIP CURRENTS FOR ALL AREA BEACHES ON WEDNESDAY. && .CLIMATE... RECORD LOW TEMPS FOR JUNE 27TH... KCHS...65 SET IN 1967 AND PREVIOUS. KCHL...66 SET IN 1967. KSAV...63 SET IN 1979. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ330- 350-352. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT THURSDAY NIGHT FOR AMZ374. SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR AMZ354. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE... CLIMATE...
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1030 PM EDT THU JUN 28 2012 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 315 PM EDT THU JUN 28 2012 RECORD BREAKING HEAT SET TO ARRIVE OVER THE OHIO VALLEY LATE THIS AFTERNOON AND FRIDAY AS DEEP UPPER RIDGING EXPANDS INTO THE REGION. A WEAK FRONTAL BOUNDARY WILL SLIP INTO THE LOWER GREAT LAKES TONIGHT AND REMAIN IN THE REGION THROUGH THE WEEKEND. THE PROXIMITY OF THE FRONT MAY BE ENOUGH TO GENERATE A FEW THUNDERSTORMS BUT EXPECT MOST LOCATIONS WILL REMAIN DRY. HOT WEATHER WILL PERSIST INTO NEXT WEEK AS THE CORE OF THE UPPER RIDGE REMAINS CENTERED JUST TO THE WEST OVER THE CENTRAL PLAINS. && .NEAR TERM /TONIGHT/... ISSUED AT 1030 PM EDT THU JUN 28 2012 WILL HAVE TO ADD ISOLATED THUNDER TO A SLIVER OF FAR NORTH CENTRAL INDIANA. THESE STORMS CONTINUE TO WEAKEN BUT WILL GET CLOSE ENOUGH TO THE FORECAST AREA BOUNDARY THAT A MENTION IS PROBABLY NECESSARY. PREVIOUS DISCUSSION FOLLOWS. GOING FORECAST WAS IN FAIRLY GOOD SHAPE...ONLY SOME MINOR TWEAKS REQUIRED. SMALL COMPLEX OF STRONG TO SEVERE THUNDERSTORMS ONGOING ACROSS NORTHWEST INDIANA MAY THREATEN TO CROSS THE NORTHERN BORDER OF THE FORECAST AREA...BUT SUSPECT THAT THESE STORMS WILL QUICKLY DIE AS THEY BECOME FURTHER REMOVED FROM THE LAKE BREEZE BOUNDARY. THIS IS SUPPORTED BY HRRR REFLECTIVITY PROGS AND 700 MB TEMPS OF 16C. IN FACT...THESE STORMS ARE ALREADY BEGINNING TO WEAKEN. WILL HAVE TO MONITOR THIS CLOSELY OVER THE NEXT 1 TO 2 HOURS. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... ISSUED AT 315 PM EDT THU JUN 28 2012 ...NEAR RECORD HIGH TEMPERATURES AND FIRE DANGER CONTINUE FRIDAY AND INTO THIS WEEKEND... FORECAST CHALLENGES REMAIN ON THE HEAT AND TO A LESSER EXTENT POTENTIAL FIRE DANGER (AGAIN DISCUSSED IN MORE DETAIL IN THE FIRE SECTION BELOW). AS THE HEAT RIDGE SLOWLY SINKS BACK TO THE SOUTHWEST. ADDITIONAL CHALLENGES REGARDING CONVECTIVE CHANCES AS WEAK BOUNDARY DROPS INTO THE REGION. POTENTIAL FOR A CONTINUATION OF THE IMPRESSIVE HEAT THROUGH THE PERIOD BUT THE PRESENCE OF THE FRONT INTO THE REGION INTRODUCES ADDITIONAL VARIABLES INTO THE FORECAST THAT WILL HAVE IMPACTS POTENTIALLY ON TEMPS. CONVECTIVE DEVELOPMENT REMAINS A DISTINCT POSSIBILITY IN THE VICINITY OF THE FRONT FRIDAY THROUGH SATURDAY...BUT SEVERAL LIMITING FACTORS TO CONSIDER. WARM BOUNDARY LAYER HIGHLIGHTED BY LARGE AMOUNTS OF CONVECTIVE INHIBITION AND DESPITE AN INCREASE IN DEWPOINTS AS SOME MOISTURE POOLING DEVELOPS IN VICINITY OF THE BOUNDARY...STRONGLY SUSPECT MODELS ARE STILL OVERDOING AVAILABLE LOW LEVEL MOISTURE BOTH DAYS. WITH THAT BEING SAID...THIS KIND OF HEAT IS GENERATING ABUNDANT INSTABILITY ABOVE THE INVERSION AND SHOULD THE CAPPING WEAKEN ENOUGH EITHER DAY... POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WITH A DAMAGING WIND THREAT WOULD BE POSSIBLE. MODEL CONSENSUS ALSO SUGGESTING CONVECTIVE COMPLEXES COULD DEVELOP AND RIDE THE RIDGE PERIPHERY THROUGH THE PERIOD...POSSIBLY IMPACTING NORTHERN COUNTIES. WITH THE LIMITING FACTORS MENTIONED ABOVE HOWEVER...WILL CARRY NO HIGHER THAN 20 POPS NORTH OF A TERRE HAUTE TO GREENSBURG LINE FRIDAY/FRIDAY NIGHT... SINKING A TOUCH FURTHER SOUTH ON SATURDAY DUE TO POTENTIAL LOCATION OF THE BOUNDARY. THE POTENTIAL FOR PERIODS OF CLOUDS AND CONVECTION DO INCREASE UNCERTAINTY IN TEMP FORECASTS FRIDAY AND SATURDAY...BUT STILL FEEL PERSISTENCE IS THE BEST OPTION AT THIS POINT. BOUNDARY LAYER TEMPS WILL BE COOLER BOTH DAYS THAN TODAY DUE TO THE FLATTENING OF THE RIDGE. TEMPS...WILL BE WELL ABOVE THE MAVMOS GUIDANCE FOR HIGHS BOTH FRIDAY THROUGH SUNDAY WITH THE HIGHLIGHTED PROBLEMS THE OPERATIONAL GFS IS EXPERIENCING WITH SAMPLING BOUNDARY LAYER CONDITIONS. WILL BE MUCH CLOSER TO THE METMOS...AND HAVE GENERALLY BUMPED TEMPS A DEGREE OR TWO FROM PREVIOUS FORECAST BOTH DAYS. RECORD HIGHS AT INDY WILL BE THREATENED BOTH DAYS. ALSO TO NOTE...INDIANAPOLIS HAS ONLY HAD CONSECUTIVE DAYS AT 100 OR HIGHER IN JUNE HAPPEN ONCE IN RECORDED HISTORY...FROM JUNE 28-30 1934. AM FORECASTING 101 ON FRIDAY AND NEAR 100 ON SATURDAY AND SUNDAY IN INDY. UNDERCUT MOS GUIDANCE ON OVERNIGHT LOWS BASED ON RECENT PERFORMANCE AND ANTECEDENT DRY CONDITIONS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 216 PM EDT THU JUN 28 2012 MAIN CHALLENGE TO THE EXTENDED WILL BE WHETHER OR NOT AND IF SO... WHEN TO HAVE THUNDERSTORM POPS. TEMPERATURES WILL ALSO BE FOCUSED ON WITH THE SEVERE DROUGHT IN PROGRESS. AGREE WITH THE PMDEPD FROM HPC IN THROWING THE 12Z GFS OUT WHICH PLACES CENTRAL INDIANA CLOSER TO THE RIDGE RIDING QPF. THE 00Z ECMWF AND OTHERS SPREAD THE PLAINS RIDGE FURTHER NORTHEAST ACROSS CENTRAL INDIANA THROUGH THE EXTENDED WHICH WOULD TEND TO SUPPRESS THUNDERSTORM DEVELOPMENT. IN ADDITION...THE ONGOING DROUGHT WOULD TEND TO FAVOR A DRY FORECAST WITH AFTERNOON TEMPERATURES A COUPLE OF DEGREES WARMER THAN THE CENTRAL REGION INITIALIZATION AND DEW POINTS A FEW DEGREES LOWER. && .AVIATION /DISCUSSION FOR THE 290300Z IND TAF UPDATE/... VFR CONDITIONS ARE EXPECTED TO CONTINUE. LITTLE CHANGE TO THE ONGOING FORECAST. CONVECTION IN NORTHERN INDIANA IS EXPECTED TO REMAIN NORTH OF THE IND TAF SITE...HOWEVER SOME PROPAGATION OF HIGH CIRRUS MAY BE POSSIBLE. IF ANY CI ARRIVES NEAR IND ANY CIG WILL REMAIN STRONGLY VFR. WILL MONITOR TRENDS FOR NEXT TAF ISSUANCE. PREVIOUS DISCUSSION BELOW /DISCUSSION FOR THE 290000Z IND TAFS/... ISSUED AT 629 PM EDT THU JUN 28 2012 VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD. SATELLITE IMAGES SHOW A THIN BAND OF CU ACROSS NORTHERN ILLINOIS AND CENTRAL IOWA ASSOCIATED WITH A COOL FRONT EDGING TOWARD THE TAF SITES. THIS BOUNDARY IS EXPECTED TO PUSH INTO THE AREA OVERNIGHT...AFTER DAYTIME HEATING IS LOST AND THE VFR CU ASSOCIATED WITH THE FRONT ARE EXPECTED TO DIMINISH OR DISSIPATE. THUS HAVE TRENDED TOWARD A MENTION OF SOME SCT CU AT BEST OVER NIGHT. MASSIVE RIDGE AND HIGH PRESSURE ACROSS THE REGION WILL CONTINUE IT/S GRIP ON CENTRAL INDIANA ON FRIDAY. FORECAST SOUNDINGS REMAIN VERY DRY...WITH UNREACHABLE CONVECTIVE TEMPS. THUS EXPECT JUST THE STRAY CI CLOUD ON FRIDAY. .FIRE WEATHER... ISSUED AT 950 PM EDT THU JUN 28 2012 RED FLAG WARNING HAS BEEN ALLOWED TO EXPIRE AS CONDITIONS HAVE IMPROVED WITH LOSS OF DAYTIME HEATING. ELEVATED FIRE DANGER WILL EXIST WITH EXPECTED CONDITIONS FOR FRIDAY AND SATURDAY. AT THIS TIME WE DO NOT BELIEVE THE CONDITIONS WILL WARRANT A RED FLAG WARNING...BUT MAY REQUIRE ENHANCED FIRE DANGER WORDING...ALONG A SPECIAL WEATHER STATEMENT AND MENTION IN THE HAZARDOUS WEATHER OUTLOOK. && .CLIMATE... ISSUED AT 950 PM EDT THU JUN 28 2012 RECORD HIGHS FOR KIND: ALL TIME - 106 (7/14/1936...7/21/1934...7/22/1901) JUNE - 104 (6/28/2012) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) && .IND WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ SYNOPSIS...SMF NEAR TERM...NIELD SHORT TERM...RYAN/SMF LONG TERM....MK AVIATION...JP FIRE...SMF/NIELD CLIMATE...RYAN/NIELD
AREA FORECAST DISCUSSION...CORRECTED
NWS INDIANAPOLIS IN
1022 PM EDT THU JUN 28 2012 .UPDATE... AVIATION SECTIONS UPDATED && .SYNOPSIS... ISSUED AT 315 PM EDT THU JUN 28 2012 RECORD BREAKING HEAT SET TO ARRIVE OVER THE OHIO VALLEY LATE THIS AFTERNOON AND FRIDAY AS DEEP UPPER RIDGING EXPANDS INTO THE REGION. A WEAK FRONTAL BOUNDARY WILL SLIP INTO THE LOWER GREAT LAKES TONIGHT AND REMAIN IN THE REGION THROUGH THE WEEKEND. THE PROXIMITY OF THE FRONT MAY BE ENOUGH TO GENERATE A FEW THUNDERSTORMS BUT EXPECT MOST LOCATIONS WILL REMAIN DRY. HOT WEATHER WILL PERSIST INTO NEXT WEEK AS THE CORE OF THE UPPER RIDGE REMAINS CENTERED JUST TO THE WEST OVER THE CENTRAL PLAINS. && .NEAR TERM /TONIGHT/... ISSUED AT 950 PM EDT THU JUN 28 2012 GOING FORECAST WAS IN FAIRLY GOOD SHAPE...ONLY SOME MINOR TWEAKS REQUIRED. SMALL COMPLEX OF STRONG TO SEVERE THUNDERSTORMS ONGOING ACROSS NORTHWEST INDIANA MAY THREATEN TO CROSS THE NORTHERN BORDER OF THE FORECAST AREA...BUT SUSPECT THAT THESE STORMS WILL QUICKLY DIE AS THEY BECOME FURTHER REMOVED FROM THE LAKE BREEZE BOUNDARY. THIS IS SUPPORTED BY HRRR REFLECTIVITY PROGS AND 700 MB TEMPS OF 16C. IN FACT...THESE STORMS ARE ALREADY BEGINNING TO WEAKEN. WILL HAVE TO MONITOR THIS CLOSELY OVER THE NEXT 1 TO 2 HOURS. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... ISSUED AT 315 PM EDT THU JUN 28 2012 ...NEAR RECORD HIGH TEMPERATURES AND FIRE DANGER CONTINUE FRIDAY AND INTO THIS WEEKEND... FORECAST CHALLENGES REMAIN ON THE HEAT AND TO A LESSER EXTENT POTENTIAL FIRE DANGER (AGAIN DISCUSSED IN MORE DETAIL IN THE FIRE SECTION BELOW). AS THE HEAT RIDGE SLOWLY SINKS BACK TO THE SOUTHWEST. ADDITIONAL CHALLENGES REGARDING CONVECTIVE CHANCES AS WEAK BOUNDARY DROPS INTO THE REGION. POTENTIAL FOR A CONTINUATION OF THE IMPRESSIVE HEAT THROUGH THE PERIOD BUT THE PRESENCE OF THE FRONT INTO THE REGION INTRODUCES ADDITIONAL VARIABLES INTO THE FORECAST THAT WILL HAVE IMPACTS POTENTIALLY ON TEMPS. CONVECTIVE DEVELOPMENT REMAINS A DISTINCT POSSIBILITY IN THE VICINITY OF THE FRONT FRIDAY THROUGH SATURDAY...BUT SEVERAL LIMITING FACTORS TO CONSIDER. WARM BOUNDARY LAYER HIGHLIGHTED BY LARGE AMOUNTS OF CONVECTIVE INHIBITION AND DESPITE AN INCREASE IN DEWPOINTS AS SOME MOISTURE POOLING DEVELOPS IN VICINITY OF THE BOUNDARY...STRONGLY SUSPECT MODELS ARE STILL OVERDOING AVAILABLE LOW LEVEL MOISTURE BOTH DAYS. WITH THAT BEING SAID...THIS KIND OF HEAT IS GENERATING ABUNDANT INSTABILITY ABOVE THE INVERSION AND SHOULD THE CAPPING WEAKEN ENOUGH EITHER DAY... POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WITH A DAMAGING WIND THREAT WOULD BE POSSIBLE. MODEL CONSENSUS ALSO SUGGESTING CONVECTIVE COMPLEXES COULD DEVELOP AND RIDE THE RIDGE PERIPHERY THROUGH THE PERIOD...POSSIBLY IMPACTING NORTHERN COUNTIES. WITH THE LIMITING FACTORS MENTIONED ABOVE HOWEVER...WILL CARRY NO HIGHER THAN 20 POPS NORTH OF A TERRE HAUTE TO GREENSBURG LINE FRIDAY/FRIDAY NIGHT... SINKING A TOUCH FURTHER SOUTH ON SATURDAY DUE TO POTENTIAL LOCATION OF THE BOUNDARY. THE POTENTIAL FOR PERIODS OF CLOUDS AND CONVECTION DO INCREASE UNCERTAINTY IN TEMP FORECASTS FRIDAY AND SATURDAY...BUT STILL FEEL PERSISTENCE IS THE BEST OPTION AT THIS POINT. BOUNDARY LAYER TEMPS WILL BE COOLER BOTH DAYS THAN TODAY DUE TO THE FLATTENING OF THE RIDGE. TEMPS...WILL BE WELL ABOVE THE MAVMOS GUIDANCE FOR HIGHS BOTH FRIDAY THROUGH SUNDAY WITH THE HIGHLIGHTED PROBLEMS THE OPERATIONAL GFS IS EXPERIENCING WITH SAMPLING BOUNDARY LAYER CONDITIONS. WILL BE MUCH CLOSER TO THE METMOS...AND HAVE GENERALLY BUMPED TEMPS A DEGREE OR TWO FROM PREVIOUS FORECAST BOTH DAYS. RECORD HIGHS AT INDY WILL BE THREATENED BOTH DAYS. ALSO TO NOTE...INDIANAPOLIS HAS ONLY HAD CONSECUTIVE DAYS AT 100 OR HIGHER IN JUNE HAPPEN ONCE IN RECORDED HISTORY...FROM JUNE 28-30 1934. AM FORECASTING 101 ON FRIDAY AND NEAR 100 ON SATURDAY AND SUNDAY IN INDY. UNDERCUT MOS GUIDANCE ON OVERNIGHT LOWS BASED ON RECENT PERFORMANCE AND ANTECEDENT DRY CONDITIONS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 216 PM EDT THU JUN 28 2012 MAIN CHALLENGE TO THE EXTENDED WILL BE WHETHER OR NOT AND IF SO... WHEN TO HAVE THUNDERSTORM POPS. TEMPERATURES WILL ALSO BE FOCUSED ON WITH THE SEVERE DROUGHT IN PROGRESS. AGREE WITH THE PMDEPD FROM HPC IN THROWING THE 12Z GFS OUT WHICH PLACES CENTRAL INDIANA CLOSER TO THE RIDGE RIDING QPF. THE 00Z ECMWF AND OTHERS SPREAD THE PLAINS RIDGE FURTHER NORTHEAST ACROSS CENTRAL INDIANA THROUGH THE EXTENDED WHICH WOULD TEND TO SUPPRESS THUNDERSTORM DEVELOPMENT. IN ADDITION...THE ONGOING DROUGHT WOULD TEND TO FAVOR A DRY FORECAST WITH AFTERNOON TEMPERATURES A COUPLE OF DEGREES WARMER THAN THE CENTRAL REGION INITIALIZATION AND DEW POINTS A FEW DEGREES LOWER. && .AVIATION /DISCUSSION FOR THE 290300Z IND TAF UPDATE/... VFR CONDITIONS ARE EXPECTED TO CONTINUE. LITTLE CHANGE TO THE ONGOING FORECAST. CONVECTION IN NORTHERN INDIANA IS EXPECTED TO REMAIN NORTH OF THE IND TAF SITE...HOWEVER SOME PROPAGATION OF HIGH CIRRUS MAY BE POSSIBLE. IF ANY CI ARRIVES NEAR IND ANY CIG WILL REMAIN STRONGLY VFR. WILL MONITOR TRENDS FOR NEXT TAF ISSUANCE. PREVIOUS DISCUSSION BELOW /DISCUSSION FOR THE 290000Z IND TAFS/... ISSUED AT 629 PM EDT THU JUN 28 2012 VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD. SATELLITE IMAGES SHOW A THIN BAND OF CU ACROSS NORTHERN ILLINOIS AND CENTRAL IOWA ASSOCIATED WITH A COOL FRONT EDGING TOWARD THE TAF SITES. THIS BOUNDARY IS EXPECTED TO PUSH INTO THE AREA OVERNIGHT...AFTER DAYTIME HEATING IS LOST AND THE VFR CU ASSOCIATED WITH THE FRONT ARE EXPECTED TO DIMINISH OR DISSIPATE. THUS HAVE TRENDED TOWARD A MENTION OF SOME SCT CU AT BEST OVER NIGHT. MASSIVE RIDGE AND HIGH PRESSURE ACROSS THE REGION WILL CONTINUE IT/S GRIP ON CENTRAL INDIANA ON FRIDAY. FORECAST SOUNDINGS REMAIN VERY DRY...WITH UNREACHABLE CONVECTIVE TEMPS. THUS EXPECT JUST THE STRAY CI CLOUD ON FRIDAY. .FIRE WEATHER... ISSUED AT 950 PM EDT THU JUN 28 2012 RED FLAG WARNING HAS BEEN ALLOWED TO EXPIRE AS CONDITIONS HAVE IMPROVED WITH LOSS OF DAYTIME HEATING. ELEVATED FIRE DANGER WILL EXIST WITH EXPECTED CONDITIONS FOR FRIDAY AND SATURDAY. AT THIS TIME WE DO NOT BELIEVE THE CONDITIONS WILL WARRANT A RED FLAG WARNING...BUT MAY REQUIRE ENHANCED FIRE DANGER WORDING...ALONG A SPECIAL WEATHER STATEMENT AND MENTION IN THE HAZARDOUS WEATHER OUTLOOK. && .CLIMATE... ISSUED AT 950 PM EDT THU JUN 28 2012 RECORD HIGHS FOR KIND: ALL TIME - 106 (7/14/1936...7/21/1934...7/22/1901) JUNE - 104 (6/28/2012) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) && .IND WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ SYNOPSIS...SMF NEAR TERM...NIELD SHORT TERM...RYAN/SMF LONG TERM....MK AVIATION...JP FIRE...SMF/NIELD CLIMATE...RYAN/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1010 PM EDT THU JUN 28 2012 .UPDATE... NO SECTIONS UPDATED && .SYNOPSIS... ISSUED AT 315 PM EDT THU JUN 28 2012 RECORD BREAKING HEAT SET TO ARRIVE OVER THE OHIO VALLEY LATE THIS AFTERNOON AND FRIDAY AS DEEP UPPER RIDGING EXPANDS INTO THE REGION. A WEAK FRONTAL BOUNDARY WILL SLIP INTO THE LOWER GREAT LAKES TONIGHT AND REMAIN IN THE REGION THROUGH THE WEEKEND. THE PROXIMITY OF THE FRONT MAY BE ENOUGH TO GENERATE A FEW THUNDERSTORMS BUT EXPECT MOST LOCATIONS WILL REMAIN DRY. HOT WEATHER WILL PERSIST INTO NEXT WEEK AS THE CORE OF THE UPPER RIDGE REMAINS CENTERED JUST TO THE WEST OVER THE CENTRAL PLAINS. && .NEAR TERM /TONIGHT/... ISSUED AT 950 PM EDT THU JUN 28 2012 GOING FORECAST WAS IN FAIRLY GOOD SHAPE...ONLY SOME MINOR TWEAKS REQUIRED. SMALL COMPLEX OF STRONG TO SEVERE THUNDERSTORMS ONGOING ACROSS NORTHWEST INDIANA MAY THREATEN TO CROSS THE NORTHERN BORDER OF THE FORECAST AREA...BUT SUSPECT THAT THESE STORMS WILL QUICKLY DIE AS THEY BECOME FURTHER REMOVED FROM THE LAKE BREEZE BOUNDARY. THIS IS SUPPORTED BY HRRR REFLECTIVITY PROGS AND 700 MB TEMPS OF 16C. IN FACT...THESE STORMS ARE ALREADY BEGINNING TO WEAKEN. WILL HAVE TO MONITOR THIS CLOSELY OVER THE NEXT 1 TO 2 HOURS. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... ISSUED AT 315 PM EDT THU JUN 28 2012 ...NEAR RECORD HIGH TEMPERATURES AND FIRE DANGER CONTINUE FRIDAY AND INTO THIS WEEKEND... FORECAST CHALLENGES REMAIN ON THE HEAT AND TO A LESSER EXTENT POTENTIAL FIRE DANGER (AGAIN DISCUSSED IN MORE DETAIL IN THE FIRE SECTION BELOW). AS THE HEAT RIDGE SLOWLY SINKS BACK TO THE SOUTHWEST. ADDITIONAL CHALLENGES REGARDING CONVECTIVE CHANCES AS WEAK BOUNDARY DROPS INTO THE REGION. POTENTIAL FOR A CONTINUATION OF THE IMPRESSIVE HEAT THROUGH THE PERIOD BUT THE PRESENCE OF THE FRONT INTO THE REGION INTRODUCES ADDITIONAL VARIABLES INTO THE FORECAST THAT WILL HAVE IMPACTS POTENTIALLY ON TEMPS. CONVECTIVE DEVELOPMENT REMAINS A DISTINCT POSSIBILITY IN THE VICINITY OF THE FRONT FRIDAY THROUGH SATURDAY...BUT SEVERAL LIMITING FACTORS TO CONSIDER. WARM BOUNDARY LAYER HIGHLIGHTED BY LARGE AMOUNTS OF CONVECTIVE INHIBITION AND DESPITE AN INCREASE IN DEWPOINTS AS SOME MOISTURE POOLING DEVELOPS IN VICINITY OF THE BOUNDARY...STRONGLY SUSPECT MODELS ARE STILL OVERDOING AVAILABLE LOW LEVEL MOISTURE BOTH DAYS. WITH THAT BEING SAID...THIS KIND OF HEAT IS GENERATING ABUNDANT INSTABILITY ABOVE THE INVERSION AND SHOULD THE CAPPING WEAKEN ENOUGH EITHER DAY... POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WITH A DAMAGING WIND THREAT WOULD BE POSSIBLE. MODEL CONSENSUS ALSO SUGGESTING CONVECTIVE COMPLEXES COULD DEVELOP AND RIDE THE RIDGE PERIPHERY THROUGH THE PERIOD...POSSIBLY IMPACTING NORTHERN COUNTIES. WITH THE LIMITING FACTORS MENTIONED ABOVE HOWEVER...WILL CARRY NO HIGHER THAN 20 POPS NORTH OF A TERRE HAUTE TO GREENSBURG LINE FRIDAY/FRIDAY NIGHT... SINKING A TOUCH FURTHER SOUTH ON SATURDAY DUE TO POTENTIAL LOCATION OF THE BOUNDARY. THE POTENTIAL FOR PERIODS OF CLOUDS AND CONVECTION DO INCREASE UNCERTAINTY IN TEMP FORECASTS FRIDAY AND SATURDAY...BUT STILL FEEL PERSISTENCE IS THE BEST OPTION AT THIS POINT. BOUNDARY LAYER TEMPS WILL BE COOLER BOTH DAYS THAN TODAY DUE TO THE FLATTENING OF THE RIDGE. TEMPS...WILL BE WELL ABOVE THE MAVMOS GUIDANCE FOR HIGHS BOTH FRIDAY THROUGH SUNDAY WITH THE HIGHLIGHTED PROBLEMS THE OPERATIONAL GFS IS EXPERIENCING WITH SAMPLING BOUNDARY LAYER CONDITIONS. WILL BE MUCH CLOSER TO THE METMOS...AND HAVE GENERALLY BUMPED TEMPS A DEGREE OR TWO FROM PREVIOUS FORECAST BOTH DAYS. RECORD HIGHS AT INDY WILL BE THREATENED BOTH DAYS. ALSO TO NOTE...INDIANAPOLIS HAS ONLY HAD CONSECUTIVE DAYS AT 100 OR HIGHER IN JUNE HAPPEN ONCE IN RECORDED HISTORY...FROM JUNE 28-30 1934. AM FORECASTING 101 ON FRIDAY AND NEAR 100 ON SATURDAY AND SUNDAY IN INDY. UNDERCUT MOS GUIDANCE ON OVERNIGHT LOWS BASED ON RECENT PERFORMANCE AND ANTECEDENT DRY CONDITIONS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 216 PM EDT THU JUN 28 2012 MAIN CHALLENGE TO THE EXTENDED WILL BE WHETHER OR NOT AND IF SO... WHEN TO HAVE THUNDERSTORM POPS. TEMPERATURES WILL ALSO BE FOCUSED ON WITH THE SEVERE DROUGHT IN PROGRESS. AGREE WITH THE PMDEPD FROM HPC IN THROWING THE 12Z GFS OUT WHICH PLACES CENTRAL INDIANA CLOSER TO THE RIDGE RIDING QPF. THE 00Z ECMWF AND OTHERS SPREAD THE PLAINS RIDGE FURTHER NORTHEAST ACROSS CENTRAL INDIANA THROUGH THE EXTENDED WHICH WOULD TEND TO SUPPRESS THUNDERSTORM DEVELOPMENT. IN ADDITION...THE ONGOING DROUGHT WOULD TEND TO FAVOR A DRY FORECAST WITH AFTERNOON TEMPERATURES A COUPLE OF DEGREES WARMER THAN THE CENTRAL REGION INITIALIZATION AND DEW POINTS A FEW DEGREES LOWER. && .AVIATION /DISCUSSION FOR THE 290300Z IND TAF UPDATE/... VFR CONDITIONS ARE EXPECTED TO CONTINUE. LITTLE CHANGE TO THE ONGOING FORECAST. CONVECTION IN NORTHERN INDIANA IS EXPECTED TO REMAIN NORTH OF THE IND TAF SITE...HOWEVER SOME PROPAGATION OF HIGH CIRRUS MAY BE POSSIBLE. IF ANY CI ARRIVES NEAR IND ANY CIG WILL REMAIN STRONGLY VFR. WILL MONITOR TRENDS FOR NEXT TAF ISSUANCE. PREVIOUS DISCUSSION BELOW /DISCUSSION FOR THE 290000Z IND TAFS/... ISSUED AT 629 PM EDT THU JUN 28 2012 VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD. SATELLITE IMAGES SHOW A THIN BAND OF CU ACROSS NORTHERN ILLINOIS AND CENTRAL IOWA ASSOCIATED WITH A COOL FRONT EDGING TOWARD THE TAF SITES. THIS BOUNDARY IS EXPECTED TO PUSH INTO THE AREA OVERNIGHT...AFTER DAYTIME HEATING IS LOST AND THE VFR CU ASSOCIATED WITH THE FRONT ARE EXPECTED TO DIMINISH OR DISSIPATE. THUS HAVE TRENDED TOWARD A MENTION OF SOME SCT CU AT BEST OVER NIGHT. MASSIVE RIDGE AND HIGH PRESSURE ACROSS THE REGION WILL CONTINUE IT/S GRIP ON CENTRAL INDIANA ON FRIDAY. FORECAST SOUNDINGS REMAIN VERY DRY...WITH UNREACHABLE CONVECTIVE TEMPS. THUS EXPECT JUST THE STRAY CI CLOUD ON FRIDAY. .FIRE WEATHER... ISSUED AT 950 PM EDT THU JUN 28 2012 RED FLAG WARNING HAS BEEN ALLOWED TO EXPIRE AS CONDITIONS HAVE IMPROVED WITH LOSS OF DAYTIME HEATING. ELEVATED FIRE DANGER WILL EXIST WITH EXPECTED CONDITIONS FOR FRIDAY AND SATURDAY. AT THIS TIME WE DO NOT BELIEVE THE CONDITIONS WILL WARRANT A RED FLAG WARNING...BUT MAY REQUIRE ENHANCED FIRE DANGER WORDING...ALONG A SPECIAL WEATHER STATEMENT AND MENTION IN THE HAZARDOUS WEATHER OUTLOOK. && .CLIMATE... ISSUED AT 950 PM EDT THU JUN 28 2012 RECORD HIGHS FOR KIND: ALL TIME - 106 (7/14/1936...7/21/1934...7/22/1901) JUNE - 104 (6/28/2012) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) && .IND WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ SYNOPSIS...SMF NEAR TERM...NIELD SHORT TERM...RYAN/SMF LONG TERM....MK AVIATION...JP FIRE...SMF/NIELD CLIMATE...RYAN/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
950 PM EDT THU JUN 28 2012 .UPDATE... THE NEAR TERM...FIRE WEATHER...AND CLIMATE SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 315 PM EDT THU JUN 28 2012 RECORD BREAKING HEAT SET TO ARRIVE OVER THE OHIO VALLEY LATE THIS AFTERNOON AND FRIDAY AS DEEP UPPER RIDGING EXPANDS INTO THE REGION. A WEAK FRONTAL BOUNDARY WILL SLIP INTO THE LOWER GREAT LAKES TONIGHT AND REMAIN IN THE REGION THROUGH THE WEEKEND. THE PROXIMITY OF THE FRONT MAY BE ENOUGH TO GENERATE A FEW THUNDERSTORMS BUT EXPECT MOST LOCATIONS WILL REMAIN DRY. HOT WEATHER WILL PERSIST INTO NEXT WEEK AS THE CORE OF THE UPPER RIDGE REMAINS CENTERED JUST TO THE WEST OVER THE CENTRAL PLAINS. && .NEAR TERM /TONIGHT/... ISSUED AT 950 PM EDT THU JUN 28 2012 GOING FORECAST WAS IN FAIRLY GOOD SHAPE...ONLY SOME MINOR TWEAKS REQUIRED. SMALL COMPLEX OF STRONG TO SEVERE THUNDERSTORMS ONGOING ACROSS NORTHWEST INDIANA MAY THREATEN TO CROSS THE NORTHERN BORDER OF THE FORECAST AREA...BUT SUSPECT THAT THESE STORMS WILL QUICKLY DIE AS THEY BECOME FURTHER REMOVED FROM THE LAKE BREEZE BOUNDARY. THIS IS SUPPORTED BY HRRR REFLECTIVITY PROGS AND 700 MB TEMPS OF 16C. IN FACT...THESE STORMS ARE ALREADY BEGINNING TO WEAKEN. WILL HAVE TO MONITOR THIS CLOSELY OVER THE NEXT 1 TO 2 HOURS. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... ISSUED AT 315 PM EDT THU JUN 28 2012 ...NEAR RECORD HIGH TEMPERATURES AND FIRE DANGER CONTINUE FRIDAY AND INTO THIS WEEKEND... FORECAST CHALLENGES REMAIN ON THE HEAT AND TO A LESSER EXTENT POTENTIAL FIRE DANGER (AGAIN DISCUSSED IN MORE DETAIL IN THE FIRE SECTION BELOW). AS THE HEAT RIDGE SLOWLY SINKS BACK TO THE SOUTHWEST. ADDITIONAL CHALLENGES REGARDING CONVECTIVE CHANCES AS WEAK BOUNDARY DROPS INTO THE REGION. POTENTIAL FOR A CONTINUATION OF THE IMPRESSIVE HEAT THROUGH THE PERIOD BUT THE PRESENCE OF THE FRONT INTO THE REGION INTRODUCES ADDITIONAL VARIABLES INTO THE FORECAST THAT WILL HAVE IMPACTS POTENTIALLY ON TEMPS. CONVECTIVE DEVELOPMENT REMAINS A DISTINCT POSSIBILITY IN THE VICINITY OF THE FRONT FRIDAY THROUGH SATURDAY...BUT SEVERAL LIMITING FACTORS TO CONSIDER. WARM BOUNDARY LAYER HIGHLIGHTED BY LARGE AMOUNTS OF CONVECTIVE INHIBITION AND DESPITE AN INCREASE IN DEWPOINTS AS SOME MOISTURE POOLING DEVELOPS IN VICINITY OF THE BOUNDARY...STRONGLY SUSPECT MODELS ARE STILL OVERDOING AVAILABLE LOW LEVEL MOISTURE BOTH DAYS. WITH THAT BEING SAID...THIS KIND OF HEAT IS GENERATING ABUNDANT INSTABILITY ABOVE THE INVERSION AND SHOULD THE CAPPING WEAKEN ENOUGH EITHER DAY... POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WITH A DAMAGING WIND THREAT WOULD BE POSSIBLE. MODEL CONSENSUS ALSO SUGGESTING CONVECTIVE COMPLEXES COULD DEVELOP AND RIDE THE RIDGE PERIPHERY THROUGH THE PERIOD...POSSIBLY IMPACTING NORTHERN COUNTIES. WITH THE LIMITING FACTORS MENTIONED ABOVE HOWEVER...WILL CARRY NO HIGHER THAN 20 POPS NORTH OF A TERRE HAUTE TO GREENSBURG LINE FRIDAY/FRIDAY NIGHT... SINKING A TOUCH FURTHER SOUTH ON SATURDAY DUE TO POTENTIAL LOCATION OF THE BOUNDARY. THE POTENTIAL FOR PERIODS OF CLOUDS AND CONVECTION DO INCREASE UNCERTAINTY IN TEMP FORECASTS FRIDAY AND SATURDAY...BUT STILL FEEL PERSISTENCE IS THE BEST OPTION AT THIS POINT. BOUNDARY LAYER TEMPS WILL BE COOLER BOTH DAYS THAN TODAY DUE TO THE FLATTENING OF THE RIDGE. TEMPS...WILL BE WELL ABOVE THE MAVMOS GUIDANCE FOR HIGHS BOTH FRIDAY THROUGH SUNDAY WITH THE HIGHLIGHTED PROBLEMS THE OPERATIONAL GFS IS EXPERIENCING WITH SAMPLING BOUNDARY LAYER CONDITIONS. WILL BE MUCH CLOSER TO THE METMOS...AND HAVE GENERALLY BUMPED TEMPS A DEGREE OR TWO FROM PREVIOUS FORECAST BOTH DAYS. RECORD HIGHS AT INDY WILL BE THREATENED BOTH DAYS. ALSO TO NOTE...INDIANAPOLIS HAS ONLY HAD CONSECUTIVE DAYS AT 100 OR HIGHER IN JUNE HAPPEN ONCE IN RECORDED HISTORY...FROM JUNE 28-30 1934. AM FORECASTING 101 ON FRIDAY AND NEAR 100 ON SATURDAY AND SUNDAY IN INDY. UNDERCUT MOS GUIDANCE ON OVERNIGHT LOWS BASED ON RECENT PERFORMANCE AND ANTECEDENT DRY CONDITIONS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 216 PM EDT THU JUN 28 2012 MAIN CHALLENGE TO THE EXTENDED WILL BE WHETHER OR NOT AND IF SO... WHEN TO HAVE THUNDERSTORM POPS. TEMPERATURES WILL ALSO BE FOCUSED ON WITH THE SEVERE DROUGHT IN PROGRESS. AGREE WITH THE PMDEPD FROM HPC IN THROWING THE 12Z GFS OUT WHICH PLACES CENTRAL INDIANA CLOSER TO THE RIDGE RIDING QPF. THE 00Z ECMWF AND OTHERS SPREAD THE PLAINS RIDGE FURTHER NORTHEAST ACROSS CENTRAL INDIANA THROUGH THE EXTENDED WHICH WOULD TEND TO SUPPRESS THUNDERSTORM DEVELOPMENT. IN ADDITION...THE ONGOING DROUGHT WOULD TEND TO FAVOR A DRY FORECAST WITH AFTERNOON TEMPERATURES A COUPLE OF DEGREES WARMER THAN THE CENTRAL REGION INITIALIZATION AND DEW POINTS A FEW DEGREES LOWER. && .AVIATION /DISCUSSION FOR THE 290000Z IND TAFS/... ISSUED AT 629 PM EDT THU JUN 28 2012 VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD. SATELLITE IMAGES SHOW A THIN BAND OF CU ACROSS NORTHERN ILLINOIS AND CENTRAL IOWA ASSOCIATED WITH A COOL FRONT EDGING TOWARD THE TAF SITES. THIS BOUNDARY IS EXPECTED TO PUSH INTO THE AREA OVERNIGHT...AFTER DAYTIME HEATING IS LOST AND THE VFR CU ASSOCIATED WITH THE FRONT ARE EXPECTED TO DIMINISH OR DISSIPATE. THUS HAVE TRENDED TOWARD A MENTION OF SOME SCT CU AT BEST OVER NIGHT. MASSIVE RIDGE AND HIGH PRESSURE ACROSS THE REGION WILL CONTINUE IT/S GRIP ON CENTRAL INDIANA ON FRIDAY. FORECAST SOUNDINGS REMAIN VERY DRY...WITH UNREACHABLE CONVECTIVE TEMPS. THUS EXPECT JUST THE STRAY CI CLOUD ON FRIDAY. && .FIRE WEATHER... ISSUED AT 950 PM EDT THU JUN 28 2012 RED FLAG WARNING HAS BEEN ALLOWED TO EXPIRE AS CONDITIONS HAVE IMPROVED WITH LOSS OF DAYTIME HEATING. ELEVATED FIRE DANGER WILL EXIST WITH EXPECTED CONDITIONS FOR FRIDAY AND SATURDAY. AT THIS TIME WE DO NOT BELIEVE THE CONDITIONS WILL WARRANT A RED FLAG WARNING...BUT MAY REQUIRE ENHANCED FIRE DANGER WORDING...ALONG A SPECIAL WEATHER STATEMENT AND MENTION IN THE HAZARDOUS WEATHER OUTLOOK. && .CLIMATE... ISSUED AT 950 PM EDT THU JUN 28 2012 RECORD HIGHS FOR KIND: ALL TIME - 106 (7/14/1936...7/21/1934...7/22/1901) JUNE - 104 (6/28/2012) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) && .IND WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ SYNOPSIS...SMF NEAR TERM...NIELD SHORT TERM...RYAN/SMF LONG TERM....MK AVIATION...JP FIRE...SMF/NIELD CLIMATE...RYAN/NIELD
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
838 PM EDT THU JUN 28 2012 .UPDATE... RED FLAG AND HEAT ADVISORY ALLOWED TO EXPIRE. SURFACE BASED CAPE IS EXCEPTIONALLY HIGH OVER THE REGION. COMBINED WITH THE LAKE BREEZE AND OUTFLOW FROM SEVERE CONVECTION OVER CHICAGO AREA... ADDITIONAL CONVECTION IS LIKELY TO SPREAD OVER THE WESTERN QUARTER OF THE CWA. THIS HAS PROMPTED THE ISSUANCE OF SEVERE THUNDERSTORM WATCH 433 UNTIL MIDNIGHT EDT. BEST LOCATION FOR SEVERE THREAT APPEARS TO BE FROM LAPORTE... STARKE AND PULASKI COUNTIES...WITH THE MOST LIKELY PLACEMENT ALONG THE EXISTING SURFACE BOUNDARY ALONG THE STARKE/PULASKI COUNTY LINE. EXPECT THAT AS THE OUTFLOW SURGES SOUTH...THE FOCUS WILL SHIFT FURTHER SOUTH QUICKLY. && .PREV DISCUSSION... /ISSUED 736 PM EDT THU JUN 28 2012/ AVIATION... 00Z AVIATION... BOUNDARY LAYER TROF CUTS ACROSS NORTHERN INDIANA FROM FWA TO VPZ. LAKE BREEZE TRIGGERED CONVECTION OVER THE CHICAGO AREA AND STORMS RAPIDLY SPREAD EAST. LACK OF MOISTURE AND STRONG CAP HAS SUPPRESSED FURTHER DEVELOPMENT INTO THE FORECAST AREA. WITH THE OUTFLOW BOUNDARY PUSHING OFF LAKE MICHIGAN...STILL EXPECT TO SEE ISOLATED CONVECTIVE DEVLOPMENT AT/NEAR SBN AND THUS HAVE INTRODUCED VCTS FOR APPROXIMATELY 5 HOURS. WITH STABLE AND STAGNANT AIR IN PLACE DURING SUNRISE...EXPECT LOWER VSBY AT THE AIRPORTS UNTIL MIXING OCCURS. PREV DISCUSSION... /ISSUED 403 PM EDT THU JUN 28 2012/ SHORT TERM... TONIGHT THROUGH FRIDAY NIGHT. CONT TO FAVOR CAUTIONARY APPROACH WRT POTNL CONVECTIVE DEVELOPMENT IN SHORT TERM FOR CWA. DESPITE INCSRG INSTABILITY THIS AFT/EVE AS SFC DPS BEGIN TO POOL TO NEAR 70F ACRS NWRN CWA THIS AFTN...FAVORED INITIATION REGIONS EXIST BOTH DOWN/UPSTREAM. STILL MODELS SPCLY GFS CONTS TO FAIL TO CAPTURE SIGNIFICANCE OF DRY GROUND/D3 DROUGHT CONDS THAT HAVE EMERGED ACRS NRN IN AND CONT TO SHAVE SVRL DEGREES DOWNWARD. THIS AM NOTED SHORTWAVE/700H JETLET GENERATED XTRMLY HIGH ELEVATED CONVECTION INVOF KCID...THIS FEATURE TO PUSH INTO NWRN OH THIS EVE WITH CAP SLOWLY DERIDED PER SPC RAP IN TANDEM WITH CONCEPTUAL MODEL EXPECTATIONS...THOUGH EAST OF CWA. WELL WEST OF CWA WITHIN DCPVA ZONE AMID OVERLAP ALONG NRN EDGE OF STRONGER/LESS INHIBITED INSTABILITY AXIS FM NWRN IL WWD INTO SERN NE WITH MLCAPE 4000-5000 J/KG AND SRN PERIPHERY OF HIR DEEP LYR /0-6KM/ SHEAR OF 40-55KTS TO LKLY SUPPORT MULTIPLE MCS DEVELOPMENT ACRS PLAINS INTO INTO IA/MO NEAR/AFTER SUNSET AS SRLY 925-850MB JET STRENGTHENS/NOSES ACRS CNTL KS. ADDNL/CONTD CONVECTIVE SUPPORT ACRS IA/MO THROUGH DAYBREAK AS ERN PERIPHERY OF LLJ VEERS. LACK OF ULVL JET SUPPORT ACRS CWA FURTHER POINTS TO LIKEN DRY BEGETS DRY. FLATTENED RIDGE TO ALLOW SHALLOW SFC FNTL ZONE TO SLIDE SEWD QUIETLY THROUGH CWA...WITH ZONE OF RICH 0-0.5KM THETA-E LAID OUT FM NRN IL INTO CNTL IN ON FRIDAY. SLIGHT CHC FOR LATE AFTN/EVE CONVECTION INITIATION RELEGATED TO ONLY SWRN CWA INVOF BNDRY WITH INCRSD UPPER LVL DIVERGENCE AS NRN PLAINS UPR JETLET MOVES INTO SERN LWR MI/LWR GRTLKS COINCIDENT WITH GREATEST INSTABILITY. LONG TERM... / SATURDAY THROUGH THURSDAY / WEST TO NORTHWEST FLOW ALOFT IS EXPECTED TO PERSIST THIS WEEKEND INTO EARLY NEXT WEEK OVERTOP A FLATTENED UPPER LEVEL RIDGE. THE POLAR JET WILL GENERALLY REMAIN WELL NORTH AND EAST OF THE REGION STILL ALLOWING HIGHS TO REACH THE 90S EACH DAY AS 850 HPA TEMPS GENERALLY STAY AOA 20C...WITH MID LVL CLOUD DEBRIS FROM UPSTREAM CONVECTION BEING THE ONLY HOPE FOR COOLER TEMPS. AT THE SURFACE A DIFFUSE/SHALLOW QUASI-STATIONARY BOUNDARY IS FCST TO HANG AROUND THE NORTHERN OHIO VALLEY WWD TOWARDS THE CENTRAL PLAINS THROUGH SUNDAY...POSSIBLY MIXING NORTH OF THE AREA OR WASHING OUT BY MONDAY. WILL LIKELY SEE CONVECTIVE COMPLEXES FIRE IN THE VICINITY OF THIS BOUNDARY FRIDAY AND SATURDAY NIGHT NEAR IOWA AS SEVERAL LOW AMPLITUDE (CONVECTIVELY ENHANCED/INDUCED) SHORTWAVES CREST THE REBUILDING CENTRAL PLAINS UPPER RIDGE. THESE POTENTIAL MCS COMPLEXES WILL LIKELY WEAKEN WITH EWD PROGRESSION AS THEY OUTRUN BETTER LOW LVL FORCING (LLJ) AND DRY OUT OVER POORLY MODELED DRY LOW LEVELS (MODELS OVERDOING BOUNDARY LAYER/SOIL MOISTURE WITH CLIMO BIAS AND THEREFORE INSTABILITY/SFC DEWPOINTS/ETC). WITH THIS CONFIDENCE FOR ANY MEASURABLE RAINFALL REMAINS LOW DURING THIS TIME AS THINK THE BEST CASE SCENARIO IS FOR A MCV TO BRING HIGH BASED SHOWERS WITH LITTLE/NO DROUGHT RELIEF. ALSO EXPECT AFTERNOON CONVECTIVE RE-DEVELOPMENT TO BE ISOLATED AT BEST ALONG ANY COMPOSITE OUTFLOW BOUNDARIES. AS A RESULT OPTED TO KEEP POPS IN THE 10-20 PERCENT RANGE (MAINLY NO WX MENTION) AS WOULD EXPECT MOST OF THIS PERIOD TO BE DRY IN THIS ONGOING D1-D3 DROUGHT. THE ROCKIES/CENTRAL ROCKIES UPPER RIDGE WILL BUILD NWD TOWARDS THE UPPER MIDWEST NEXT WEEK WITH HEIGHT RISES/WARMING AND DRY CONDITIONS ANTICIPATED LOCALLY. TEMPS COULD MAKE ANOTHER RUN AT 100F BY DAYS 6/7. AVIATION... /18 UTC TAFS/ DIFFICULT FCST THIS ITERATION...MAINTAIN PRIMARILY VFR TAFS WITH POINT CONVECTIVE CHCS REMAINING BLO THRESHOLD FOR INCLUSION AS MLCIN RMNS STOIC ACRS NRN IN THIS AFTN. HEIGHTENED CHCS FOR INITIATION EXIST BOTH UP/DOWNSTREAM OF RGN LATER THIS EVENING...POTNLY PROVIDING DRY FROPA LATER TONIGHT. CONVERGENCE OF NEAR SFC HYGROSCOPIC POLLUTANTS AND SFC DP POOLING TO NEAR 70 MAY PROVIDE IMPETUS FOR SUNRISE BR DVLPMNT. ZONE OF HIR SFC BASED INSTABILITY THEREAFTER RELEGATED FM ERN IA INTO CNTL IN MIDDAY FRIDAY/FRIDAY AFTN...TAKING FOCUS AREA FOR REDEVELOPMENT SOUTH OF TAF SITES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...LEWIS LONG TERM...STEINWEDEL AVIATION...LEWIS UPDATE...LEWIS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
736 PM EDT THU JUN 28 2012 .AVIATION... 00Z AVIATION... BOUNDARY LAYER TROF CUTS ACROSS NORTHERN INDIANA FROM FWA TO VPZ. LAKE BREEZE TRIGGERED CONVECTION OVER THE CHICAGO AREA AND STORMS RAPIDLY SPREAD EAST. LACK OF MOISTURE AND STRONG CAP HAS SUPPRESSED FURTHER DEVELOPMENT INTO THE FORECAST AREA. WITH THE OUTFLOW BOUNDARY PUSHING OFF LAKE MICHIGAN...STILL EXPECT TO SEE ISOLATED CONVECTIVE DEVLOPMENT AT/NEAR SBN AND THUS HAVE INTRODUCED VCTS FOR APPROXIMATELY 5 HOURS. WITH STABLE AND STAGNANT AIR IN PLACE DURING SUNRISE...EXPECT LOWER VSBY AT THE AIRPORTS UNTIL MIXING OCCURS. && .PREV DISCUSSION... /ISSUED 403 PM EDT THU JUN 28 2012/ SHORT TERM... TONIGHT THROUGH FRIDAY NIGHT. CONT TO FAVOR CAUTIONARY APPROACH WRT POTNL CONVECTIVE DEVELOPMENT IN SHORT TERM FOR CWA. DESPITE INCSRG INSTABILITY THIS AFT/EVE AS SFC DPS BEGIN TO POOL TO NEAR 70F ACRS NWRN CWA THIS AFTN...FAVORED INITIATION REGIONS EXIST BOTH DOWN/UPSTREAM. STILL MODELS SPCLY GFS CONTS TO FAIL TO CAPTURE SIGNIFICANCE OF DRY GROUND/D3 DROUGHT CONDS THAT HAVE EMERGED ACRS NRN IN AND CONT TO SHAVE SVRL DEGREES DOWNWARD. THIS AM NOTED SHORTWAVE/700H JETLET GENERATED XTRMLY HIGH ELEVATED CONVECTION INVOF KCID...THIS FEATURE TO PUSH INTO NWRN OH THIS EVE WITH CAP SLOWLY DERIDED PER SPC RAP IN TANDEM WITH CONCEPTUAL MODEL EXPECTATIONS...THOUGH EAST OF CWA. WELL WEST OF CWA WITHIN DCPVA ZONE AMID OVERLAP ALONG NRN EDGE OF STRONGER/LESS INHIBITED INSTABILITY AXIS FM NWRN IL WWD INTO SERN NE WITH MLCAPE 4000-5000 J/KG AND SRN PERIPHERY OF HIR DEEP LYR /0-6KM/ SHEAR OF 40-55KTS TO LKLY SUPPORT MULTIPLE MCS DEVELOPMENT ACRS PLAINS INTO INTO IA/MO NEAR/AFTER SUNSET AS SRLY 925-850MB JET STRENGTHENS/NOSES ACRS CNTL KS. ADDNL/CONTD CONVECTIVE SUPPORT ACRS IA/MO THROUGH DAYBREAK AS ERN PERIPHERY OF LLJ VEERS. LACK OF ULVL JET SUPPORT ACRS CWA FURTHER POINTS TO LIKEN DRY BEGETS DRY. FLATTENED RIDGE TO ALLOW SHALLOW SFC FNTL ZONE TO SLIDE SEWD QUIETLY THROUGH CWA...WITH ZONE OF RICH 0-0.5KM THETA-E LAID OUT FM NRN IL INTO CNTL IN ON FRIDAY. SLIGHT CHC FOR LATE AFTN/EVE CONVECTION INITIATION RELEGATED TO ONLY SWRN CWA INVOF BNDRY WITH INCRSD UPPER LVL DIVERGENCE AS NRN PLAINS UPR JETLET MOVES INTO SERN LWR MI/LWR GRTLKS COINCIDENT WITH GREATEST INSTABILITY. LONG TERM... / SATURDAY THROUGH THURSDAY / WEST TO NORTHWEST FLOW ALOFT IS EXPECTED TO PERSIST THIS WEEKEND INTO EARLY NEXT WEEK OVERTOP A FLATTENED UPPER LEVEL RIDGE. THE POLAR JET WILL GENERALLY REMAIN WELL NORTH AND EAST OF THE REGION STILL ALLOWING HIGHS TO REACH THE 90S EACH DAY AS 850 HPA TEMPS GENERALLY STAY AOA 20C...WITH MID LVL CLOUD DEBRIS FROM UPSTREAM CONVECTION BEING THE ONLY HOPE FOR COOLER TEMPS. AT THE SURFACE A DIFFUSE/SHALLOW QUASI-STATIONARY BOUNDARY IS FCST TO HANG AROUND THE NORTHERN OHIO VALLEY WWD TOWARDS THE CENTRAL PLAINS THROUGH SUNDAY...POSSIBLY MIXING NORTH OF THE AREA OR WASHING OUT BY MONDAY. WILL LIKELY SEE CONVECTIVE COMPLEXES FIRE IN THE VICINITY OF THIS BOUNDARY FRIDAY AND SATURDAY NIGHT NEAR IOWA AS SEVERAL LOW AMPLITUDE (CONVECTIVELY ENHANCED/INDUCED) SHORTWAVES CREST THE REBUILDING CENTRAL PLAINS UPPER RIDGE. THESE POTENTIAL MCS COMPLEXES WILL LIKELY WEAKEN WITH EWD PROGRESSION AS THEY OUTRUN BETTER LOW LVL FORCING (LLJ) AND DRY OUT OVER POORLY MODELED DRY LOW LEVELS (MODELS OVERDOING BOUNDARY LAYER/SOIL MOISTURE WITH CLIMO BIAS AND THEREFORE INSTABILITY/SFC DEWPOINTS/ETC). WITH THIS CONFIDENCE FOR ANY MEASURABLE RAINFALL REMAINS LOW DURING THIS TIME AS THINK THE BEST CASE SCENARIO IS FOR A MCV TO BRING HIGH BASED SHOWERS WITH LITTLE/NO DROUGHT RELIEF. ALSO EXPECT AFTERNOON CONVECTIVE RE-DEVELOPMENT TO BE ISOLATED AT BEST ALONG ANY COMPOSITE OUTFLOW BOUNDARIES. AS A RESULT OPTED TO KEEP POPS IN THE 10-20 PERCENT RANGE (MAINLY NO WX MENTION) AS WOULD EXPECT MOST OF THIS PERIOD TO BE DRY IN THIS ONGOING D1-D3 DROUGHT. THE ROCKIES/CENTRAL ROCKIES UPPER RIDGE WILL BUILD NWD TOWARDS THE UPPER MIDWEST NEXT WEEK WITH HEIGHT RISES/WARMING AND DRY CONDITIONS ANTICIPATED LOCALLY. TEMPS COULD MAKE ANOTHER RUN AT 100F BY DAYS 6/7. AVIATION... /18 UTC TAFS/ DIFFICULT FCST THIS ITERATION...MAINTAIN PRIMARILY VFR TAFS WITH POINT CONVECTIVE CHCS REMAINING BLO THRESHOLD FOR INCLUSION AS MLCIN RMNS STOIC ACRS NRN IN THIS AFTN. HEIGHTENED CHCS FOR INITIATION EXIST BOTH UP/DOWNSTREAM OF RGN LATER THIS EVENING...POTNLY PROVIDING DRY FROPA LATER TONIGHT. CONVERGENCE OF NEAR SFC HYGROSCOPIC POLLUTANTS AND SFC DP POOLING TO NEAR 70 MAY PROVIDE IMPETUS FOR SUNRISE BR DVLPMNT. ZONE OF HIR SFC BASED INSTABILITY THEREAFTER RELEGATED FM ERN IA INTO CNTL IN MIDDAY FRIDAY/FRIDAY AFTN...TAKING FOCUS AREA FOR REDEVELOPMENT SOUTH OF TAF SITES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR INZ008-009-012>018-020-022>027-032>034. RED FLAG WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR INZ005>009-012>018-020-022>027-032>034. HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR INZ003>007. MI...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ077>081. OH...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ004- 005-015-016-024-025. RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ001-002-004- 005-015-016-024-025. HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ001-002. LM...NONE. && $$ SHORT TERM...MURPHY LONG TERM...STEINWEDEL AVIATION...LEWIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
951 PM CDT THU JUN 28 2012 .UPDATE... REMOVED A FEW MORE COUNTIES FROM HEAT ADVISORY OVER NORTHEAST IA AND NORTHWEST IL... AS DRIER AIR CONTINUES MOVING IN ALLOW GRADUAL IMPROVEMENT IN CONDITIONS. ZFP/GRID UPDATE HAS BEEN SENT. OTRW... CHCS STILL EXIST FOR STORMS OVRNGT... ESPECIALLY AFT 09Z AND CONTINUING FRI AM WITH VEERING LOW LEVEL JET AND APPROACHING DISTURBANCE FROM CO. && .PREV DISCUSSION... /ISSUED 809 PM CDT THU JUN 28 2012/ UPDATE... SENT ZFP/GRID UPDATE TO REMOVE NORTHEAST IA COUNTIES MAINLY ALONG AND NORTH OF HWY 30 FROM HEAT ADVISORY... AS MUCH DRIER AIR IS BRINGING MARKED IMPROVEMENT IN CONDITIONS THERE. WILL CONTINUE TO MONITOR PROGRESS OF LOW LEVEL DRYING TNGT FOR ADDITIONAL CHGS TO HEAT ADVISORY. LATEST FEW RUNS OF RAP MODEL HAVE BEEN SHOWING DEWPTS LOWERING INTO THE 50S AND 60S DOWN TO I-80 IN EASTERN IA. ALSO REMOVED SLIGHT CHC POPS HWY 20 CORRIDOR THIS EVE WITH THE DRIER AIR. CHANCE OF STORMS STILL LOOKS REASONABLE OVERNIGHT AND FRI MORNING AS NEXT IMPULSE OVER CO MOVES E/NE AROUND PERIPHERY OF HEAT DOME AND INTO AREA WHILE INTERACTING WITH STALLING FRONTAL ZONE OVER SOUTHEAST IA INTO WEST CENTRAL IL. FAVORED CORRIDOR FOR PCPN SHOULD IT DEVELOP APPEARS TO BE HWY 30 TO HWY 34... BUT THIS COULD SHIFT SOUTHWARD SOME DEPENDING ON MOVEMENT OF LOW LEVEL DRIER AIR. SEVERE THREAT EXISTS WITH ANY ORGANIZED CONVECTION GIVEN EXTREME INSTABILITY... WITH MAIN THREAT BEING DAMAGING WIND. PREV DISCUSSION... /ISSUED 713 PM CDT THU JUN 28 2012/ AVIATION... COLD FRONT OVER SOUTHEAST IA AND WEST CENTRAL IL IS EXPECTED TO BECOME STATIONARY TNGT AND REMAIN IN THE VICINITY OF THE AREA THROUGH FRI. WATCHING DISTURBANCE OVER CO THAT WILL MOVE E/NE AROUND PERIPHERY OF HEAT DOME AND TOWARD OUR AREA INTO FRI. THIS MAY INTERACT WITH FRONT TO BRING TSRA TO PORTIONS OF AREA WITH SUGGESTION OF HWY 30 SWD TO HWY 34 CORRIDOR BEING MOST FAVORED. STILL A LOT OF UNCERTAINTY ON MODELS WITH COVERAGE BUT POTENTIAL IS THERE FOR UPSCALE GROWTH TO MCS WITH DAMAGING WIND THREAT GIVEN EXTREME INSTABILITY AND HIGH WET BULB ZERO HEIGHTS OF 13-15KFT AGL. FOR NOW HAVE ADDED VCTS MENTION LATE TNGT INTO FRI AM FOR ALL TERMINALS EXCEPT FOR KDBQ WHERE DRIER AIR IS MOVING IN. LARGE POOLING OF MOISTURE NEAR FRONT WITH SFC DEWPTS IN THE 70S TO NR 80 DEGS COUPLED WITH LIGHT WINDS LIKELY TO BRING SOME REDUCED VSBYS OF 3-6SM IN HAZE AND FOG. THERE IS ALSO THE POTENTIAL FOR MVFR TO IFR CONDITIONS WITH ANY TSRA MAINLY FOR VSBY. PREV DISCUSSION... /ISSUED 322 PM CDT THU JUN 28 2012/ SYNOPSIS... 12Z UA ANALYSIS HAS AN 850MB COLD FRONT FROM UPPER MICHIGAN INTO WESTERN NEBRASKA WITH MID AND UPPER TEEN DEW POINTS ALONG AND JUST AHEAD OF IT. A WEAK LLJ RAN FROM WEST TEXAS INTO THE MID MISSISSIPPI VALLEY. SATELLITE IMAGES THROUGH MID AFTERNOON SHOW PLENTY OF ACCAS AND SOME DIURNAL CU DEVELOPMENT ASSOCIATED WITH THE SFC COLD FRONT FROM WISCONSIN INTO NEBRASKA. 18Z SFC ANALYSIS HAD A WEAK LOW JUST EAST OF KMKE WITH ANOTHER IN SOUTHWEST KANSAS. THE COLD FRONT RAN IN BETWEEN THE TWO LOWS WITH A PRE-FRONTAL TROF FROM SOUTHEAST WISCONSIN INTO NORTHWEST MISSOURI. DEW POINTS IN THE VICINITY OF THE FRONT WERE IN THE LOW AND MID 70S. DEW POINTS DROPPED OFF QUICKLY INTO THE 40S AND 50S ACROSS THE NORTHERN PLAINS. SHORT TERM...TONIGHT AND FRIDAY NONLINEAR PROCESSES ARE DOMINATING THE SENSIBLE WX WHICH RESULTS IN LOW MODEL PREDICTABILITY. BASED ON EXTRAPOLATION/INTERPOLATION OF SFC OBS...IT APPEARS THE HEAT ADVISORY VERIFIED FOR A FEW HOURS OVER THE SOUTHERN PARTS OF BUCHANAN AND DELAWARE COUNTIES...SOUTH OF HWY 20...WHEN USING DATA FROM RWIS SITES. THROUGH MID AFTERNOON THE ACCAS AND SFC BASED CU DEVELOPMENT BEHIND THE FRONT HAS BECOME SLIGHTLY MORE AGITATED. RIGHT NOW IT LOOKS DOUBTFUL THAT ANY ELEVATED CONVECTION WILL DEVELOP BUT WILL INCLUDE SCHC POPS IN THE HWY 20 CORRIDOR THIS EVENING IN CASE SOMETHING DEVELOPS. THE HEAT HEADLINES WILL REMAIN AS IS BUT THERE IS A POSSIBILITY OF AN EXTENSION OVER THE SOUTH 40 PERCENT OF THE CWFA FOR FRIDAY. ALL OF THIS IS DEPENDENT ON WHERE AND IF CONVECTION DEVELOPS OVERNIGHT. THE HEAT HEADLINES FOR A GOOD CHUNK OF THE CWFA WILL PROBABLY BE CANCELLED LATE THIS EVENING OR OVERNIGHT. USING CONCEPTUAL MODELS AND SATELLITE DATA...AN MCS SHOULD DEVELOP IN THE VICINITY OF KOMA BY MIDNIGHT. THE OVERALL FLOW SHOULD TAKE IT GENERALLY EASTWARD WITH THE AREA SOUTH OF HIGHWAY 20 AND NORTH OF HIGHWAY 34 FAVORED. CONVECTION WOULD BE ELEVATED. A NEGATIVE FOR DEVELOPMENT TONIGHT IS THAT THE LLJ IS NOT AS STRONG AS LAST NIGHT. ASSUMING CONVECTION DOES DEVELOP AND MOVE AS SUGGESTED BY THE TRACK OF VORT MAXES...A DECAYING MCS SHOULD BE OVER THE CWFA FRIDAY MORNING. BOUNDARIES FROM THIS MCS AND AN APPROACHING VORT MAX...LIKELY FROM ANOTHER MCS...SHOULD INITIATE DIURNAL CONVECTION FRIDAY AFTERNOON ACROSS THE CWFA. CONVECTION THAT DEVELOPS FRIDAY AFTERNOON COULD GET INTERESTING. DIFFERENTIAL THETA E LAPSE RATES WILL BE VERY LARGE. SO...STORMS THAT DEVELOP COULD BE OF THE PULSE SEVERE TYPE WITH WIND BEING THE PRIMARY THREAT. 08 LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY ABOVE NORMAL TEMPERATURES AND HUMID WITH A CHANCE OF THUNDERSTORMS MOST...IF NOT ALL DAYS. OVERVIEW...CHALLENGING FORECAST OF WHERE AND WHEN CONVECTION OCCURS. INITIALIZATION GOOD WITH NORMAL PROBLEMS OF LOW LEVEL MOISTURE FIELDS THAT HAVE PLAGUED MOST GUIDANCE THE PAST SEVERAL WEEKS TO MONTHS. VERIFICATION AT 18Z SUGGESTS USING FORCING OF MAINLY A MIX OF GFS/NAM/HI-RES ECMWF. THIS IS A TYPICAL SUMMER PRECIPITATION REGIME OF VERY GOOD CONFIDENCE OF EPISODES OF CONVECTION..BUT PROBABLY POOR ON TIMING AND LOCATION BEYOND 6-12 HOURS AHEAD DUE TO NON-LINEAR NATURE AND OUTFLOW BOUNDARIES IMPACTING SUBSEQUENT CONVECTION. HIGH TO EXTREME STABILITY WITH MUCAPES OF 2500 TO 4000+ J/KG...MAX DIFFERENTIAL THETA_E OF 30C OR MORE AND WBZ 12-14K AGL SUPPORTIVE OF RISK OF DAMAGING TO VERY DAMAGING STRAIGHT LINE WINDS. THE NEXT SEVERAL DAYS COULD SEE REPORTS OF 80+ MPH WINDS NEAR OR IN OUR FORECAST AREA DUE TO THE HIGH TO EXTREME INSTABILITY. TEMPERATURES TO BE ABOVE NORMAL BY 5 TO 10 DEGREES MOST DAYS. FRIDAY NIGHT AND SATURDAY...MINOR CHANGES WITH SLIGHTLY HIGHER POPS IN NORTH 1/2 TO 2/3 AREA DUE TO STALLED FRONT OVER SOUTH PORTIONS. LOCAL TOOLS DO SUGGEST MOST LOCATIONS TO RECEIVE SOME PRECIPITATION. HIGH PW/S OF 1.5 TO 2 INCHES AND WEAKER STEERING SUGGEST LOCALLY HEAVY RAINFALL OF 2 PLUS INCHES FOR LATER SHIFTS TO RECONSIDER. BEST FORCING SUGGESTED TO OCCUR ALONG HIGHWAY 30 LATE FRIDAY NIGHT INTO SATURDAY...THIS MAY RESULT IN LOWER MAX TEMPERATURES. CONCERN OF A DECENT AREA OF STRONG WINDS AS MENTIONED EARLIER DUE TO EXTREME INSTABILITY. LOWS MOSTLY IN THE LOWER 70S AND HIGHS AROUND 90 NORTH TO MIDDLE 90S SOUTH. NORTH SECTION HIGHS COULD BE LOWER BY SEVERAL DEGREES WITH COOL POOL OUTFLOW BOUNDARY. HEAT INDICES IN SOUTH MAY REACH 100 DEGREES IN THE AFTERNOON. SOME CONCERN OF TRAINING OF STORMS THAT COULD ISOLATED VERY HEAVY RAIN AMOUNTS (AOA 3 INCHES) ALSO FOR LATER SHIFTS TO REASSESS INTO SATURDAY MORNING WITH HYDRO CONCERNS OF FLASH FLOODING. SATURDAY NIGHT THROUGH SUNDAY...LITTLE CHANGE WITH ANOTHER ROUND OF CONVECTION SUGGESTED WITH POOR CONFIDENCE OF LOCATION/S FOR LATER SHIFTS. THIS IS BECAUSE THE EARLIER OUTFLOW BOUNDARY/IES THAT SHOULD RESULT IN A DIFFERING LOCATION FOR UPDRAFT FORCING AND RAINFALL. MCS GENERATION TOOL SUPPORTS WITH A GOOD OUTFLOW BOUNDARY A FURTHER SOUTH TREND FOR LATER SHIFTS TO PRECIPITATION ATTM. SIMILAR RISKS OF SEVERE AND LOCALLY HEAVY RAINFALL WITH AGAIN IMPACTS ON HIGH TEMPERATURES POSSIBLY LOWER BY UP TO 5 DEGREES COOLER POSSIBLE...MAINLY CENTRAL OR NORTH SECTIONS. SOUTH SECTIONS COULD AGAIN EXPERIENCE HEAT INDEX VALUES OF 100 DEGREES THE AFTERNOON. SUNDAY NIGHT THROUGH THURSDAY...AREA ON EDGE OF TYPICAL MID SUMMER "RING OF FIRE" WITH LOWER RISK OF CONVECTION THAT MAY PROPAGATE INTO AREA WITH NORTHERN AND EASTERN SECTIONS AT THE GREATEST RISK. THERE WILL REMAIN A SEVERE STORM POTENTIAL WITH STRONG WINDS DUE TO HIGH INSTABILITY. TEMPERATURES LITTLE CHANGED WITH HIGHS MOSTLY 90 TO 95 DEGREES AND LOWS MOSTLY 70 TO 75 DEGREES AND AFTERNOON HEAT INDICES 95 TO 100 DEGREES SUGGESTED. NICHOLS && .DVN WATCHES/WARNINGS/ADVISORIES... IA...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR CEDAR-CLINTON-DES MOINES- HENRY IA-IOWA-JEFFERSON-JOHNSON-KEOKUK-LEE-LOUISA-MUSCATINE- SCOTT-VAN BUREN-WASHINGTON. IL...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR BUREAU-HANCOCK-HENDERSON- HENRY IL-MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-WARREN- WHITESIDE. MO...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR CLARK-SCOTLAND. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
809 PM CDT THU JUN 28 2012 .UPDATE... SENT ZFP/GRID UPDATE TO REMOVE NORTHEAST IA COUNTIES MAINLY ALONG AND NORTH OF HWY 30 FROM HEAT ADVISORY... AS MUCH DRIER AIR IS BRINGING MARKED IMPROVEMENT IN CONDITIONS THERE. WILL CONTINUE TO MONITOR PROGRESS OF LOW LEVEL DRYING TNGT FOR ADDITIONAL CHGS TO HEAT ADVISORY. LATEST FEW RUNS OF RAP MODEL HAVE BEEN SHOWING DEWPTS LOWERING INTO THE 50S AND 60S DOWN TO I-80 IN EASTERN IA. ALSO REMOVED SLIGHT CHC POPS HWY 20 CORRIDOR THIS EVE WITH THE DRIER AIR. CHANCE OF STORMS STILL LOOKS REASONABLE OVERNIGHT AND FRI MORNING AS NEXT IMPULSE OVER CO MOVES E/NE AROUND PERIPHERY OF HEAT DOME AND INTO AREA WHILE INTERACTING WITH STALLING FRONTAL ZONE OVER SOUTHEAST IA INTO WEST CENTRAL IL. FAVORED CORRIDOR FOR PCPN SHOULD IT DEVELOP APPEARS TO BE HWY 30 TO HWY 34... BUT THIS COULD SHIFT SOUTHWARD SOME DEPENDING ON MOVEMENT OF LOW LEVEL DRIER AIR. SEVERE THREAT EXISTS WITH ANY ORGANIZED CONVECTION GIVEN EXTREME INSTABILITY... WITH MAIN THREAT BEING DAMAGING WIND. && .PREV DISCUSSION... /ISSUED 713 PM CDT THU JUN 28 2012/ AVIATION... COLD FRONT OVER SOUTHEAST IA AND WEST CENTRAL IL IS EXPECTED TO BECOME STATIONARY TNGT AND REMAIN IN THE VICINITY OF THE AREA THROUGH FRI. WATCHING DISTURBANCE OVER CO THAT WILL MOVE E/NE AROUND PERIPHERY OF HEAT DOME AND TOWARD OUR AREA INTO FRI. THIS MAY INTERACT WITH FRONT TO BRING TSRA TO PORTIONS OF AREA WITH SUGGESTION OF HWY 30 SWD TO HWY 34 CORRIDOR BEING MOST FAVORED. STILL A LOT OF UNCERTAINTY ON MODELS WITH COVERAGE BUT POTENTIAL IS THERE FOR UPSCALE GROWTH TO MCS WITH DAMAGING WIND THREAT GIVEN EXTREME INSTABILITY AND HIGH WET BULB ZERO HEIGHTS OF 13-15KFT AGL. FOR NOW HAVE ADDED VCTS MENTION LATE TNGT INTO FRI AM FOR ALL TERMINALS EXCEPT FOR KDBQ WHERE DRIER AIR IS MOVING IN. LARGE POOLING OF MOISTURE NEAR FRONT WITH SFC DEWPTS IN THE 70S TO NR 80 DEGS COUPLED WITH LIGHT WINDS LIKELY TO BRING SOME REDUCED VSBYS OF 3-6SM IN HAZE AND FOG. THERE IS ALSO THE POTENTIAL FOR MVFR TO IFR CONDITIONS WITH ANY TSRA MAINLY FOR VSBY. PREV DISCUSSION... /ISSUED 322 PM CDT THU JUN 28 2012/ SYNOPSIS... 12Z UA ANALYSIS HAS AN 850MB COLD FRONT FROM UPPER MICHIGAN INTO WESTERN NEBRASKA WITH MID AND UPPER TEEN DEW POINTS ALONG AND JUST AHEAD OF IT. A WEAK LLJ RAN FROM WEST TEXAS INTO THE MID MISSISSIPPI VALLEY. SATELLITE IMAGES THROUGH MID AFTERNOON SHOW PLENTY OF ACCAS AND SOME DIURNAL CU DEVELOPMENT ASSOCIATED WITH THE SFC COLD FRONT FROM WISCONSIN INTO NEBRASKA. 18Z SFC ANALYSIS HAD A WEAK LOW JUST EAST OF KMKE WITH ANOTHER IN SOUTHWEST KANSAS. THE COLD FRONT RAN IN BETWEEN THE TWO LOWS WITH A PRE-FRONTAL TROF FROM SOUTHEAST WISCONSIN INTO NORTHWEST MISSOURI. DEW POINTS IN THE VICINITY OF THE FRONT WERE IN THE LOW AND MID 70S. DEW POINTS DROPPED OFF QUICKLY INTO THE 40S AND 50S ACROSS THE NORTHERN PLAINS. SHORT TERM...TONIGHT AND FRIDAY NONLINEAR PROCESSES ARE DOMINATING THE SENSIBLE WX WHICH RESULTS IN LOW MODEL PREDICTABILITY. BASED ON EXTRAPOLATION/INTERPOLATION OF SFC OBS...IT APPEARS THE HEAT ADVISORY VERIFIED FOR A FEW HOURS OVER THE SOUTHERN PARTS OF BUCHANAN AND DELAWARE COUNTIES...SOUTH OF HWY 20...WHEN USING DATA FROM RWIS SITES. THROUGH MID AFTERNOON THE ACCAS AND SFC BASED CU DEVELOPMENT BEHIND THE FRONT HAS BECOME SLIGHTLY MORE AGITATED. RIGHT NOW IT LOOKS DOUBTFUL THAT ANY ELEVATED CONVECTION WILL DEVELOP BUT WILL INCLUDE SCHC POPS IN THE HWY 20 CORRIDOR THIS EVENING IN CASE SOMETHING DEVELOPS. THE HEAT HEADLINES WILL REMAIN AS IS BUT THERE IS A POSSIBILITY OF AN EXTENSION OVER THE SOUTH 40 PERCENT OF THE CWFA FOR FRIDAY. ALL OF THIS IS DEPENDENT ON WHERE AND IF CONVECTION DEVELOPS OVERNIGHT. THE HEAT HEADLINES FOR A GOOD CHUNK OF THE CWFA WILL PROBABLY BE CANCELLED LATE THIS EVENING OR OVERNIGHT. USING CONCEPTUAL MODELS AND SATELLITE DATA...AN MCS SHOULD DEVELOP IN THE VICINITY OF KOMA BY MIDNIGHT. THE OVERALL FLOW SHOULD TAKE IT GENERALLY EASTWARD WITH THE AREA SOUTH OF HIGHWAY 20 AND NORTH OF HIGHWAY 34 FAVORED. CONVECTION WOULD BE ELEVATED. A NEGATIVE FOR DEVELOPMENT TONIGHT IS THAT THE LLJ IS NOT AS STRONG AS LAST NIGHT. ASSUMING CONVECTION DOES DEVELOP AND MOVE AS SUGGESTED BY THE TRACK OF VORT MAXES...A DECAYING MCS SHOULD BE OVER THE CWFA FRIDAY MORNING. BOUNDARIES FROM THIS MCS AND AN APPROACHING VORT MAX...LIKELY FROM ANOTHER MCS...SHOULD INITIATE DIURNAL CONVECTION FRIDAY AFTERNOON ACROSS THE CWFA. CONVECTION THAT DEVELOPS FRIDAY AFTERNOON COULD GET INTERESTING. DIFFERENTIAL THETA E LAPSE RATES WILL BE VERY LARGE. SO...STORMS THAT DEVELOP COULD BE OF THE PULSE SEVERE TYPE WITH WIND BEING THE PRIMARY THREAT. 08 LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY ABOVE NORMAL TEMPERATURES AND HUMID WITH A CHANCE OF THUNDERSTORMS MOST...IF NOT ALL DAYS. OVERVIEW...CHALLENGING FORECAST OF WHERE AND WHEN CONVECTION OCCURS. INITIALIZATION GOOD WITH NORMAL PROBLEMS OF LOW LEVEL MOISTURE FIELDS THAT HAVE PLAGUED MOST GUIDANCE THE PAST SEVERAL WEEKS TO MONTHS. VERIFICATION AT 18Z SUGGESTS USING FORCING OF MAINLY A MIX OF GFS/NAM/HI-RES ECMWF. THIS IS A TYPICAL SUMMER PRECIPITATION REGIME OF VERY GOOD CONFIDENCE OF EPISODES OF CONVECTION..BUT PROBABLY POOR ON TIMING AND LOCATION BEYOND 6-12 HOURS AHEAD DUE TO NON-LINEAR NATURE AND OUTFLOW BOUNDARIES IMPACTING SUBSEQUENT CONVECTION. HIGH TO EXTREME STABILITY WITH MUCAPES OF 2500 TO 4000+ J/KG...MAX DIFFERENTIAL THETA_E OF 30C OR MORE AND WBZ 12-14K AGL SUPPORTIVE OF RISK OF DAMAGING TO VERY DAMAGING STRAIGHT LINE WINDS. THE NEXT SEVERAL DAYS COULD SEE REPORTS OF 80+ MPH WINDS NEAR OR IN OUR FORECAST AREA DUE TO THE HIGH TO EXTREME INSTABILITY. TEMPERATURES TO BE ABOVE NORMAL BY 5 TO 10 DEGREES MOST DAYS. FRIDAY NIGHT AND SATURDAY...MINOR CHANGES WITH SLIGHTLY HIGHER POPS IN NORTH 1/2 TO 2/3 AREA DUE TO STALLED FRONT OVER SOUTH PORTIONS. LOCAL TOOLS DO SUGGEST MOST LOCATIONS TO RECEIVE SOME PRECIPITATION. HIGH PW/S OF 1.5 TO 2 INCHES AND WEAKER STEERING SUGGEST LOCALLY HEAVY RAINFALL OF 2 PLUS INCHES FOR LATER SHIFTS TO RECONSIDER. BEST FORCING SUGGESTED TO OCCUR ALONG HIGHWAY 30 LATE FRIDAY NIGHT INTO SATURDAY...THIS MAY RESULT IN LOWER MAX TEMPERATURES. CONCERN OF A DECENT AREA OF STRONG WINDS AS MENTIONED EARLIER DUE TO EXTREME INSTABILITY. LOWS MOSTLY IN THE LOWER 70S AND HIGHS AROUND 90 NORTH TO MIDDLE 90S SOUTH. NORTH SECTION HIGHS COULD BE LOWER BY SEVERAL DEGREES WITH COOL POOL OUTFLOW BOUNDARY. HEAT INDICES IN SOUTH MAY REACH 100 DEGREES IN THE AFTERNOON. SOME CONCERN OF TRAINING OF STORMS THAT COULD ISOLATED VERY HEAVY RAIN AMOUNTS (AOA 3 INCHES) ALSO FOR LATER SHIFTS TO REASSESS INTO SATURDAY MORNING WITH HYDRO CONCERNS OF FLASH FLOODING. SATURDAY NIGHT THROUGH SUNDAY...LITTLE CHANGE WITH ANOTHER ROUND OF CONVECTION SUGGESTED WITH POOR CONFIDENCE OF LOCATION/S FOR LATER SHIFTS. THIS IS BECAUSE THE EARLIER OUTFLOW BOUNDARY/IES THAT SHOULD RESULT IN A DIFFERING LOCATION FOR UPDRAFT FORCING AND RAINFALL. MCS GENERATION TOOL SUPPORTS WITH A GOOD OUTFLOW BOUNDARY A FURTHER SOUTH TREND FOR LATER SHIFTS TO PRECIPITATION ATTM. SIMILAR RISKS OF SEVERE AND LOCALLY HEAVY RAINFALL WITH AGAIN IMPACTS ON HIGH TEMPERATURES POSSIBLY LOWER BY UP TO 5 DEGREES COOLER POSSIBLE...MAINLY CENTRAL OR NORTH SECTIONS. SOUTH SECTIONS COULD AGAIN EXPERIENCE HEAT INDEX VALUES OF 100 DEGREES THE AFTERNOON. SUNDAY NIGHT THROUGH THURSDAY...AREA ON EDGE OF TYPICAL MID SUMMER "RING OF FIRE" WITH LOWER RISK OF CONVECTION THAT MAY PROPAGATE INTO AREA WITH NORTHERN AND EASTERN SECTIONS AT THE GREATEST RISK. THERE WILL REMAIN A SEVERE STORM POTENTIAL WITH STRONG WINDS DUE TO HIGH INSTABILITY. TEMPERATURES LITTLE CHANGED WITH HIGHS MOSTLY 90 TO 95 DEGREES AND LOWS MOSTLY 70 TO 75 DEGREES AND AFTERNOON HEAT INDICES 95 TO 100 DEGREES SUGGESTED. NICHOLS && .DVN WATCHES/WARNINGS/ADVISORIES... IA...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR CEDAR-CLINTON-DES MOINES- HENRY IA-IOWA-JACKSON-JEFFERSON-JOHNSON-KEOKUK-LEE-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR BUREAU-CARROLL-HANCOCK- HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR CLARK-SCOTLAND. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1149 PM CDT TUE JUN 26 2012 .AVIATION... VFR CONDITIONS WILL PERSIST THROUGH 06Z/28TH WITH GUSTY S/SE WINDS DEVELOPING WED AM VEERING TO SW WED AFTN. MAIN CONCERN REMAINS THE POTENTIAL FOR LLWS TOWARD DAYBREAK WED AM... MAINLY WEST OF THE MISSISSIPPI RIVER. LATEST RAP MODEL A BIT WEAKER WITH WINDS ALOFT AROUND 2000 FT AGL INDICATING 30 TO 35 KTS BY 09Z-12Z... WHILE 00Z NAM MODEL IS AROUND 40 KTS. THE SFC PRESSURE GRADIENT WILL CONTINUE TO INCREASE OVRNGT AND ANTICIPATE WINDS TO BECOME SUSTAINED AROUND 10-14 KTS BY 12Z WEST OF MISSISSIPPI RIVER WITH OCCASIONAL HIGHER GUSTS POSSIBLE. THIS WOULD PRESENT MARGINAL LLWS CONDITIONS AND THEREFORE HAVE CONTINUED TO LEAVE OUT MENTION. && .PREV DISCUSSION... /ISSUED 317 PM CDT TUE JUN 26 2012/ SYNOPSIS... SURFACE RIDGE STILL POSITIONED OVER THE GREAT LAKES THIS AFTERNOON WITH LIGHT SOUTHEAST FLOW OVER THE FORECAST AREA. A RIBBON OF WARM HUMID AIR IS STRETCHED FROM EASTERN OKLAHOMA ACROSS EASTERN KANSAS AND NEBRASKA...AND UP INTO THE DAKOTAS WITH DEWPOINTS IN THE 60S AND LOW 70S. WE STILL HAVE DEWPOINTS ONLY IN THE MID 40S TO MID 50S...FOR REASONABLY COMFORTABLE CONDITIONS. ALOFT...STRONG WARM AIR ADVECTION GOING ON AT 850MB...WITH A STRONG UPPER LEVEL RIDGE AT 500MB. 700MB SHOWS A STRONG MID LEVEL CAP OVER A LARGE AREA OF THE MIDWEST WITH A POOL OF TEMPERATURES AT OR ABOVE 12C. SHORT TERM...TONIGHT AND WEDNESDAY... TONIGHT AND WEDNESDAY THE UPPER LEVEL RIDGE CONTINUES TO BUILD OVER THE REGION. A SURFACE TROUGH COMES OUT OF THE ROCKIES AND INCREASES THE SOUTH WINDS ACROSS THE REGION...INCREASING THE LOW LEVEL WARM AIR ADVECTION AND THETA-E ADVECTION AS WELL. THIS FRONT STAYS NORTHWEST OF THE REGION THROUGH WEDNESDAY. THE WARM AIR ALOFT WILL SUPPRESS ANY CONVECTION ALONG THAT FRONT...SO WE SHOULD HAVE CLEAR OR NEARLY CLEAR SKIES THROUGH WEDNESDAY. THIS WILL CAUSE OUR TEMPERATURES TO BE HOT ON WEDNESDAY...WITH MIXING TECHNIQUES AND GUIDANCE ALL SHOWING MAX TEMPERATURES IN THE MID-UPPER 90S WEST AND LOW TO MID EAST. THE MAIN QUESTION IS GOING TO BE JUST HOW MUCH LOW LEVEL MOISTURE IS GOING TO GET IN HERE FOR WEDNESDAY. MODELS HAVE BEEN STRUGGLING WITH THIS LATELY. FOR NOW HAVE SOME UPPER 50S TO LOW 60S DEWPOINTS WEDNESDAY AFTERNOON WHICH PRODUCE HEAT INDEX VALUES AROUND 100 FOR THE FAR WESTERN COUNTIES. WILL HAVE TO WAIT AND SEE IF THIS GETS WIDESPREAD ENOUGH FOR A HEAT ADVISORY. LE LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY... ALL MODELS SHOW THE HEAT DOME BUILDING INTO THE CWFA WED NIGHT WITH BOTH 700 AND 850MB TEMPERATURES RISING ALONG WITH SLOWLY INCREASING DEW POINTS. THUS DRY CONDITIONS WILL BE SEEN WITH CONDITIONS BECOMING MORE HUMID AS THE NIGHT PROGRESSES. IT MAY BE DIFFICULT FOR TEMPERATURES TO DROP MUCH BELOW THE UPPER 70S FOR LOWS. THURSDAY WILL BE HOT AND INCREASINGLY HUMID AS THE FRONT SLOWLY MOVES INTO THE CWFA. DEPENDING UPON THE MODEL 700MB TEMPERATURES RANGE FROM 14 TO 17C DURING THE DAY. CONVECTIVE TEMPERATURES LOWER SOMEWHAT WITH A PASSING WAVE DURING THE MORNING BUT BUILD AGAIN IN THE AFTERNOON TO WELL NORTH OF 100 DEGREES. THE MAIN CONCERN THURSDAY/THURS NIGHT IS THE HEAT. BASED ON FCST TEMPS AND DEW POINTS HEADLINES FOR HEAT APPEAR LIKELY. AN EXCESSIVE HEAT WATCH WILL BE ISSUED FOR THURS/THURS NIGHT TO PROVIDE AN INITIAL HEADS UP. SEE THE CLIMATE SECTION BELOW FOR RECORD HIGHS AND RECORD WARM MINS FOR JUNE 28TH. THURSDAY EVENING WILL BE HOT AND HUMID WITH A CAPPED ATMOSPHERE ACROSS THE AREA. AFTER MIDNIGHT...THE MCS AND LIFT TOOLS SUGGEST AN MCS ARRIVING FROM THE WEST MOVING ALONG THE EDGE OF THE CAP. THE NORTHERN HALF OF THE CWFA WOULD BE MOST FAVORED TO SEE CONVECTION VERY LATE THURSDAY NIGHT AND CONTINUING INTO FRIDAY MORNING. FRIDAY...ASSUMING THE MCS MOVES ACROSS THE NORTHERN CWFA...BOUNDARIES LEFT OVER FROM THE MCS COMBINED WITH DIFFERENTIAL HEATING WOULD BE THE FOCUS FOR ADDITIONAL CONVECTION TO DEVELOP DURING THE AFTERNOON. ALL THIS IS ON THE ASSUMPTION THE PASSING SHORTWAVE AND ASSOCIATED COOLING WEAKENS THE CAP TO ALLOW CONVECTION TO DEVELOP. HEAT MAY BE A PROBLEM ON FRIDAY. HOWEVER...THE POTENTIAL FOR CONVECTIVE CLOUD DEBRIS AND POSSIBLE PRECIPITATION MAKES THE POTENTIAL FOR HEAT HEADLINES MORE QUESTIONABLE. FRIDAY NIGHT ON... MODEL CONSENSUS...WHICH IS HEAVILY AFFECTED BY THE OVERLY MOIST GFS/DGEX...GIVES SCHC/CHC POPS FRIDAY NIGHT THROUGH SUNDAY EVENING. THE MODELS HAVE AN ACTIVE TRAIN OF SUBTLE WAVES MOVING THROUGH IN THE FLOW ALOFT. THUS ANY OF THEM MAY BE CAPABLE OF PRODUCING NOCTURNAL OR DIURNAL CONVECTION. THERE WILL BE CONSIDERABLE PERIODS OF DRY WX DURING THIS TIME FRAME WITH TEMPERATURES GENERALLY AVERAGING ABOVE NORMAL. QUIET CONDITIONS SHOULD BE SEEN ON MONDAY AS NEARLY ALL MODELS AGREE ON HIGH PRESSURE ACROSS THE AREA. MONDAY NIGHT/TUESDAY THE MODEL CONSENSUS GIVES SCHC/CHC POPS WITH THE WETTER/MORE MOIST GFS AND DGEX BEING THE MAIN REASONS FOR THE POPS. THE OVERALL PATTERN CONTINUES TO REMAIN ACTIVE WITH SUBTLE WAVES IN THE FLOW ALOFT. THUS ALTHOUGH IT WILL BE DRY A MAJORITY OF THE TIME...DIURNAL AND POSSIBLY SOME NOCTURNAL CONVECTION WILL BE POSSIBLE. 08 CLIMATE... RECORD HIGHS FOR JUNE 28TH... BURLINGTON........104 IN 1934 CEDAR RAPIDS......103 IN 1931 DUBUQUE...........104 IN 1934 MOLINE............103 IN 1934 RECORD WARM MINIMUM TEMPERATURES FOR JUNE 28TH... DUBUQUE...........79 IN 1931 MOLINE............81 IN 1931 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...EXCESSIVE HEAT WATCH FROM THURSDAY MORNING THROUGH FRIDAY MORNING FOR BENTON-BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-JEFFERSON-JOHNSON- JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-SCOTT-VAN BUREN- WASHINGTON. IL...EXCESSIVE HEAT WATCH FROM THURSDAY MORNING THROUGH FRIDAY MORNING FOR BUREAU-CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON- WARREN-WHITESIDE. MO...EXCESSIVE HEAT WATCH FROM THURSDAY MORNING THROUGH FRIDAY MORNING FOR CLARK-SCOTLAND. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
710 PM CDT THU JUN 28 2012 ...UPDATED AVIATION SECTION... .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 208 PM CDT THU JUN 28 2012 A WEAK SURFACE BOUNDARY WILL EXTEND ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. EXACT LOCATION OF THIS BOUNDARY DIFFERS SLIGHTLY BETWEEN THE NAM, RAP, AND HRRR BUT ALL MODELS TEND TO SUPPORT A SMALL CHANCE FOR A FEW HIGH BASED THUNDERSTORMS NEAR THIS BOUNDARY LATE TODAY. GIVEN THIS BOUNDARY LOCATION AS OF 19Z AND SOME HINTS OF AFTERNOON CLOUDS DEVELOPING IN SOUTHEAST COLORADO NEAR THIS BOUNDARY WILL GO AHEAD AND INSERT A MENTION OF ISOLATED HIGH BASED THUNDERSTORMS IN A FEW LOCATIONS ACROSS WEST CENTRAL KANSAS...ESPECIALLY NEAR THE COLORADO BORDER. GIVEN THE FORECAST MODEL SOUNDING PROFILES ANY STORM THAT DOES DEVELOP MAY BE CAPABLE OF PRODUCING WIND GUSTS UP TO 40 MPH. ANOTHER HOT DAY IS IN STORE FOR ALL OF WESTERN KANSAS ON FRIDAY. BASED ON MODEL SOUNDINGS MIXED LAYER HEIGHT AND 700MB TEMPERATURES AT 00Z SATURDAY PLUS A SUPER SUGGESTS THE PREVIOUS FORECAST WITH HIGHS OF 105 TO 108 WERE STILL ON TRACK. THIS COMBINED WITH DEW POINTS FALLING BACK INTO THE LOW TO MID 50S WILL GIVE RISE TO FEW HOURS OF HEAT INDEX READINGS AROUND 105 DEGREES FOR A FEW LOCATIONS IN SOUTH CENTRAL AND NORTH CENTRAL KANSAS. AFTERNOON RELATIVE HUMIDITIES ACROSS ALL OF WESTERN KANSAS IS EXPECTED TO BOTTOM OUT IN THE 15 TO 20 PERCENT RANGE. AT THIS TIME AM LEANING TOWARDS ANOTHER HEAT ADVISORY FOR SEVERAL COUNTIES ONCE AGAIN ALONG AND EAST OF 183 BUT HOLD OFF ON ANY FIRE WEATHER WATCHES OR WARNINGS. A FEW HIGH BASED AFTERNOON CLOUDS WILL ALSO BE POSSIBLE ACROSS PORTIONS OF WESTERN KANSAS AGAIN LATE FRIDAY AFTERNOON AS TEMPERATURES CLIMB TO AROUND 105 DEGREES. INSTABILITY HOWEVER BASED ON MODEL SOUNDINGS NOT OVERLY IMPRESSIVE. IF A FEW STORMS DO DEVELOP THEY WILL LIKELY BE ISOLATED AND A LATE DAY/EARLY EVENING EVENT. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 257 PM CDT THU JUN 28 2012 HOT AND DRY CONDITIONS WILL CONTINUE THROUGH THE EXTENDED PERIOD. BLENDED THE FORECAST TO THE 12Z ECMWF WHICH KEEPS SOUTHWEST KANSAS DRY AND HOT. THERE MIGHT BE A SLIGHT COOL DOWN SUNDAY AS 850-700 HPA TEMPERATURES COOL SLIGHTLY AS A SUBTLE UPPER LEVEL WAVE PASSES TO THE NORTH. OTHERWISE ...THE UPPER LEVEL RIDGE AMPLIFIES THROUGH NEXT WEEK. WILL KEEP MAXES IN THE 99-102 DEG F RANGE WITH LOWS IN THE 70S DEG F. WITH SUCH WARM TEMPERATURES ALOFT, NOT EXPECTING ANY STORMS THROUGH THE PERIOD. FORECAST SOUNDINGS SHOW A WELL MIXED AND DRY ATMOSPHERE EACH DAY SO EVEN IF A STORM WOULD TO DEVELOP, IT WOULD MOST LIKELY BE VERY ISOLATED WITH ANY PRECIPITATION EVAPORATING BEFORE REACHING THE GROUND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 707 PM CDT THU JUN 28 2012 VFR CONDITIONS WILL PREVAIL ACROSS WESTERN KANSAS AS SURFACE HIGH PRESSURE IS FOUND ACROSS THE MISSISSIPPI VALLEY AND LEE TROUGHING CONTINUES ACROSS EASTERN COLORADO. WINDS WILL GENERALLY BE FROM THE SOUTH AROUND 15 KNOTS DECREASING TO AROUND 10 KNOTS AFTER MIDNIGHT. && .PRELIMINARY POINT TEMPS/POPS... DDC 71 105 75 105 / 0 10 10 10 GCK 71 106 73 103 / 0 10 10 10 EHA 69 104 73 103 / 20 10 10 10 LBL 71 106 74 103 / 0 10 10 10 HYS 74 107 75 105 / 10 10 10 10 P28 74 107 76 105 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ030-031-046-065- 066-079>081-089-090. HEAT ADVISORY FROM 1 PM TO 9 PM CDT FRIDAY FOR KSZ031-046-065- 066-079>081-089-090. && $$ SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1121 PM MDT TUE JUN 26 2012 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 127 PM MDT TUE JUN 26 2012 WV IMAGERY AND LATEST RUC H5 ANALYSIS CONTINUES TO SHOW OMEGA BLOCK ACROSS NORTH AMERICA WITH A LARGE RIDGE CENTERED OVER THE CENTRAL PLAINS. AT THE THE SURFACE A LEE TROUGH IS CURRENTLY IN PLACE OVER EASTERN COLORADO WITH ITS MEAN AXIS JUST WEST OF YUMA COUNTY COLORADO. TIGHT PRESSURE GRADIENT CURRENTLY EXTENDS ACROSS THE SOUTHEASTERN HALF OF THE CWA. WITH RIDGE IN PLACE THROUGH WEDNESDAY...HOT AND DRY CONDITIONS WILL PERSIST. A COLD FRONT WILL DROP SOUTH OVER THE CWA BY MIDDAY WEDNESDAY. NORTHWEST OF THIS FRONT TEMPERATURES WILL DECREASE SOME...HOWEVER HIGH TEMPERATURES WILL STILL MAKE IT INTO THE MIDDLE TO UPPER 90S...MAINLY OVER YUMA COUNTY. THE REST OF THE AREA WILL LIKELY STILL SEE HIGH TEMPERATURES IN THE 100S...WITH DAILY RECORDS EXPECTED ONCE AGAIN. GUIDANCE CONTINUES TO ADVERTISE QPF LATE WEDNESDAY AFTERNOON. SOUNDING ANALYSIS WOULD INDICATE THAT DRY THUNDERSTORMS WOULD BE FAVORED...WITH LIMITED COVERAGE. I INTRODUCED ISOLATED DRY THUNDERSTORMS TO THE FORECAST MAINLY ALONG AND SOUTH OF INTERSTATE 70 WHERE CONVERGENCE ALONG THE FRONT IS MOST LIKELY TO INITIATE A THUNDERSTORM OR TWO. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 145 PM MDT TUE JUN 26 2012 THE UPPER LEVEL RIDGE FLATTENS THROUGH MUCH OF THE PERIOD OPENING UP THE DOOR FOR LOW AMPLITUDE S/WV TROUGHS CRESTING OVER THE RIDGE TO MOVE NEAR THE REGION. AS SUCH THERE ARE SEVERAL LOW CHANCE OPPORTUNITIES FOR TSRA THROUGH SATURDAY EVENING. TIMING IS IN QUESTION AND WHAT IF ANYTHING DOES DEVELOP WILL BE RATHER ISOLATED. TEMPS WILL CONTINUE TO REMAIN WELL ABOVE NORMAL. LOOKING BEYOND THE PERIOD THE RIDGE RE-AMPLIFIES WITH CONTINUED HOT AND DRY CONDITIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1118 PM MDT TUE JUN 26 2012 VFR CONDITIONS EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND KMCK. A WIND SHIFT TO THE NORTH WILL OCCUR MID DAY ON WEDNESDAY AS A COLD FRONT SAGS INTO THE AREA FROM NEBRASKA. AN ISOLATED HIGH BASED THUNDERSTORM WILL BE A REMOTE POSSIBILITY IN THE AFTERNOON...WITH ACCOMPANYING THREAT OF A MICROBURST. && .FIRE WEATHER... ISSUED AT 127 PM MDT TUE JUN 26 2012 RED FLAG CONDITIONS WILL CONTINUE THROUGH THE EARLY EVENING. WINDS HAVE BEEN MARGINAL OVER WESTERN LOCATIONS CLOSER TO THE SURFACE LOW. WITH RH VALUES AROUND 5 PERCENT...VERY HOT TEMPERATURES...AND VERY DRY FUELS EVEN WINDS AROUND 15 MPH ARE ENOUGH FOR EXPLOSIVE FIRE GROWTH IN THESE CONDITIONS. I PLAN ON KEEPING RFW IN PLACE...WHICH IS CURRENTLY SET TO EXPIRE AT 9 PM MDT. A FIRE WEATHER WATCH WAS ISSUED FOR WEDNESDAY ACROSS OUR FORECAST AREA. THE BEST CHANCE FOR RH/WIND CROSSOVER FOR RFW WILL BE ACROSS THE SOUTHEAST...HOWEVER THERE IS SOME INDICATION OF WINDS INCREASING BEHIND THE FRONT...AND IF TD FAIL TO RECOVER AS QUICKLY AS CURRENTLY ADVERTISED THEN RFW WOULD BE NEEDED ACROSS THE NORTH AS WELL. IN ADDITION TO RH/WIND...THERE IS A THREAT FOR ISOLATED DRY THUNDERSTORMS GENERALLY ALONG AND SOUTH OF INTERSTATE 70 WEDNESDAY AFTERNOON AND EVENING. && .CLIMATE... ISSUED AT 145 PM MDT TUE JUN 26 2012 TODAY... GOODLAND.....107 IN 1971 HILL CITY....110 IN 1980 MCCOOK.......103 IN 1998 BURLINGTON...102 IN 1990 YUMA.........103 TRIBUNE......105 COLBY........108 WEDNESDAY... GOODLAND.....106 IN 1940 HILL CITY....107 IN 1940 MCCOOK.......107 IN 1980 BURLINGTON...104 IN 1963 YUMA.........104 TRIBUNE......105 COLBY........106 THURSDAY... GOODLAND.....106 IN 1970 HILL CITY....110 IN 1933 MCCOOK.......106 IN 1963 BURLINGTON...107 IN 1963 YUMA.........102 TRIBUNE......105 COLBY........105 GOODLAND ALL TIME HIGH FOR JUNE........109 (2012) HILL CITY ALL TIME HIGH FOR JUNE.......114 (2012) MCCOOK ALL TIME HIGH FOR JUNE..........112 (1933) BURLINGTON ALL TIME HIGH FOR JUNE......107 (1990) YUMA ALL TIME HIGH FOR JUNE............108 (2012) TRIBUNE ALL TIME HIGH FOR JUNE.........109 (2012) COLBY ALL TIME HIGH FOR JUNE...........111 (2012) GOODLAND ALL TIME HIGH TEMPERATURE.....111 (1940) HILL CITY ALL TIME HIGH TEMPERATURE....117 (1936) MCCOOK ALL TIME HIGH TEMPERATURE.......114 (1932) BURLINGTON ALL TIME HIGH TEMPERATURE...112 (1952) YUMA ALL TIME HIGH TEMPERATURE.........109 (2008 AND PREVIOUS YRS) TRIBUNE ALL TIME HIGH TEMPERATURE......109 (2012) COLBY ALL TIME HIGH TEMPERATURE........113 (1940) && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM 10 AM MDT /11 AM CDT/ WEDNESDAY THROUGH WEDNESDAY EVENING FOR KSZ001>004-013>016-027>029-041-042. HEAT ADVISORY UNTIL 10 PM CDT THURSDAY FOR KSZ002>004-014>016- 028-029-042. CO...FIRE WEATHER WATCH FROM 10 AM MDT WEDNESDAY THROUGH WEDNESDAY EVENING FOR COZ252>254. NE...FIRE WEATHER WATCH FROM 10 AM MDT /11 AM CDT/ WEDNESDAY THROUGH WEDNESDAY EVENING FOR NEZ079>081. HEAT ADVISORY UNTIL 10 PM CDT THURSDAY FOR NEZ080-081. && $$ SHORT TERM...DR LONG TERM...AP AVIATION...024 FIRE WEATHER...DR CLIMATE...AP
AREA FORECAST DISCUSSION
NWS CARIBOU ME
614 PM EDT WED JUN 27 2012 .SYNOPSIS... LOW PRESSURE WILL SLOWLY MOVE NORTHEAST TONIGHT THROUGH THURSDAY. A COLD FRONT WILL CROSS THE REGION FRIDAY. && .NEAR TERM /THROUGH THURSDAY/... UPDATE..ADJUSTED THE POPS BACK ACROSS THE WESTERN AND CENTRAL AREAS W/40% PER THE LATEST RADAR TRENDS. THE HRR AND RUC DOING WELL W/THE LATEST SETUP KEEPING HEAVIEST RAFL ACROSS THE EASTERN 3RD AND FAR NORTHERN AREAS WHERE CATEGORICAL POPS STAY(90-100%). SOME SHOWERS SHOWING AROUND THE CLOSED LOW BUT THESE SHOULD WEAKEN W/LOSS OF HEATING THAT OCCURRED. REPORTS OF AREA RIVERS AND STREAMS VERY HIGH W/HEAVY DOSE OF RAINFALL. MATTAWAMKEAG AND PENOBSCOT RIVERS THE ONES TO WATCH ATTM. NO REPORTS OF SIGNIFICANT FLOODING, JUST NUISANCE STUFF AND THOSE AREAS ARE IMPROVING SUCH AS HOWLAND AND CARMEL. PREVIOUS DISCUSSION... PESKY LOW PRES AT THE SFC AND ALOFT CONTS TO SPIN AND REMAIN NRLY STATIONARY OVR W CENTRAL MAINE ATTM... PLENTY OF MOISTURE CONTS TO WRAP AROUND THIS SYSTEM W/ SAT SHOWING MOISTURE PLUME XTNDG N-S FROM THE WRN ATLC UP ACROSS FAR NERN CANADA THEN LOOPING WWRD ACROSS NRN QUEBEC AND THEN FINALLY SWRD BACK DOWN ACROSS WRN QUEBEC AND THEN INTO OUR SYSTEM. ATTM...SOME DRIER AIR CONTS TO SLOWLY BE ENTRAINED INTO THIS SYSTEM W/ THE DRIEST AIR COMING IN ON THE NW SIDE OF THE LOW... WHERE THIS IS OCCURRING AND WHERE WE ARE SEEING SOME INSOLATION...ALSO NOTING A FEW LTG STRIKES ATTM WHERE THE AIRMASS HAS HAD A BIT MORE CHC TO DESTABILIZE. HEAVIEST AND MOST SIGNIFICANT RAIN CONTS ON THE E SIDE OF THIS LOW ACROSS ERN AND NERN PORTIONS OF OUR FA. THREE HR RADAR ESTIMATES GENERALLY SHOW .25-.5 INCH AMOUNTS ACROSS THE FAR ERN BORDER BTWN KHUL AND KCAR. COULD SEE RAINFALL TOTALS THRU TNGT OF BTWN .5-1.0 INCHES ACROSS THE NERN FA BUT DO NOT EXPECT THIS TO CAUSE ANY FLOOD ISSUES W/ THE FAR NE NOT EXPERIENCING SOME OF THE VERY HEAVY RAINFALL TOTALS THAT WERE EXPERIENCED OVR CENTRAL AREAS DURING THE PAST 3-5 DAYS. NOT A GREAT DEAL OF CHG EXPECTED THRU THE EVE HRS... LOW WILL CONT TO SPIN OVR W CENTRAL AREAS BEFORE GRADUALLY BEGINNING TO OPEN UP AND DRIFT NEWRD INTO NRN NB BY THU AM. BEST QPF WILL CONT ACROSS FAR ERN AND NERN AREAS INTO THE ERLY EVE HRS AND THEN GRADUALLY LIFT NWRD OUT OF ALL BUT EXTREME FAR NERN AREAS BY LATE TNGT/ERLY THU. WILL CONT TO MENTION SOME OCNLY HEAVY RAIN PSBL THRU THE EVE HRS ACROSS THESE AREAS. THEREAFTER...EXPECT JUST A WDSPRD SHOWERY REGIME TO PERSIST ACROSS THE AREA ON THU W/ POPS RANGING FROM CHC ACROSS THE W AND SW TO LIKELY E ERLY IN THE DAY TAPERING DOWN TO SLGT CHC W AND SW AND CHC E BY LATER IN THE DAY AS THIS STUBBORN LOW GRADUALLY RELEASES ITS GRIP ON THE AREA. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... THE UPPER LOW WILL MOVE OFF TO THE NORTHEAST THURSDAY NIGHT FINALLY PUTTING AN END TO OUR WET WEATHER PATTERN...ALBEIT ONLY BRIEFLY. THE NEXT SHORT WAVE AND ASSOCIATED WEAK COLD FRONT WILL APPROACH THE REGION ON FRIDAY AND THEN MOVE EAST FRIDAY NIGHT. THIS SYSTEM WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO THE REGION FRIDAY AFTERNOON THROUGH FRIDAY EVENING. MU CAPES ARE PROGGED TO BE IN THE 1000-1500J/KG RANGE ESPECIALLY ACROSS THE WESTERN PORTION OF THE CWA AND 0 - 6 KM SHEAR VALUES OF 40 TO 45 KT. WILL NOT MENTION ENHANCED WORDING YET BUT THINK WE COULD SEE SOME ORGANIZATION WITH ANY STORMS THAT DEVELOP SO WILL NEED TO MONITOR FOR SVR POTENTIAL. SHOWER AND THUNDERSTORMS SHOULD BE ONGOING INTO FRIDAY EVENING AND THEN DIMINISH FRIDAY NIGHT AS THE SHORT WAVE MOVES EAST OF THE STATE. EXPECT A BRIEF BREAK LATER FRIDAY NIGHT THROUGH EARLY SATURDAY. HOWEVER...ANOTHER SHORT WAVE WILL AFFECT THE REGION ON SATURDAY WITH ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS PARTICULARLY ACROSS NORTHERN AREAS. HIGH TEMPERATURES ON FRIDAY ARE EXPECTED TO BE IN THE MID TO UPPER 70S NORTH AND LOW TO MID 80S DOWNEAST...EXCEPT IT WILL BE A BIT COOLER NEAR THE COAST. HIGHS ON SATURDAY WILL EVEN BE A BIT WARMER WITH HIGHS IN THE LOW TO MID 80 ACROSS THE REGION EXCEPT A BIT COOLER ALONG THE COAST. LOW TEMPERATURES THURSDAY NIGHT AND FRIDAY NIGHT WILL GENERALLY BE IN THE MID TO UPPER 50S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... ZONAL FLOW CONTINUES ON SUNDAY WITH ABOVE NORMAL TEMPERATURES. CANNOT RULE OUT AFTERNOON AND EVENING CONVECTION. A SHORTWAVE UPPER TROUGH IS PROJECTED TO MOVE THROUGH NEW ENGLAND FROM MONDAY AFTERNOON INTO EARLY TUESDAY WITH A CHANCE OF SHOWERS OR THUNDERSTORMS. TUESDAY AND WEDNESDAY APPEAR TO DRY WITH NEAR SEASONAL TEMPERATURES IN A NORTHWEST FLOW ALOFT. && .AVIATION /22Z WEDNESDAY THROUGH MONDAY/... NEAR TERM: WDSPRD MVFR TO IFR EXPECTED TNGT W/ CONDS TO GRADUALLY IMPROVE TO VFR ALL SITES THU AM. SHORT TERM: VFR EXPECTED THURSDAY NIGHT INTO THE FIRST HALF OF FRIDAY. CONVECTIVE POTENTIAL WILL BE INCREASING DURING FRIDAY WITH A GOOD LIKELIHOOD OF SHOWERS AND THUNDERSTORMS AND THE CHANCE FOR MVFR OR EVEN BRIEF IFR FRIDAY AFTERNOON IN ANY STRONGER CONVECTIVE ELEMENTS. EXPECT CONVECTION TO LINGER INTO FRIDAY EVENING WITH IMPROVING CONDITIONS AND A RETURN TO VFR ON SATURDAY. THE POTENTIAL IS THERE FOR SOME SCT AFTERNOON CONVECTION ON SATURDAY MAINLY NORTHERN TERMINALS. MAINLY VFR SUNDAY THROUGH MONDAY BUT THERE WILL BE THE CONTINUED THREAT FOR SCT CONVECTION. && .MARINE... NEAR TERM: WILL CONT THE SCA FOR HAZ SEAS FOR OUR OUTER WATERS UNTIL MDNGT W/ SEAS AT THE ERN MAIN SHELF CURRENTLY NR 7 FT W/ 6 FT AT JONESPORT... SEAS SHOULD GRADUALLY COME DOWN LATER TNGT AND THE REMAIN BLO SCA LEVELS THRU THU. SHORT TERM: NO HEADLINES EXPECTED. && .HYDROLOGY... UPDATE...UPDATED THE FLOOD WARNING FOR THE MATTAWAMKEAG FOR IMPACT AS THE BANCROFT ROAD WILL FLOOD W/A FCST STAGE OF 13.5-14.0 FT. PREVIOUS DISCUSSION... HAVE CANX THE FLOOD WATCH FOR OUR WRN AREAS BUT HAVE EXTND THE WATCH FOR ZNS 5/6 THRU 8 PM THIS EVE. RFC NOW FCSTS THE MATTAWAMKEAG TO GO ABV FLOOD STAGE BY THU AM W/ THE RVR CURRENTLY JUST ABV ACTION STAGE. HAVE ISSUED THE POINT FLOOD WRNG FOR THE MATTAWAMKEAG AND HAVE BEEN IN CONTACT W/THE FIRE DPT IN MATTAWAMKEAG AND THEY ARE AWARE OF THE SITUATION. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MEZ005-006. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL MIDNIGHT EDT TONIGHT FOR ANZ050-051. && $$ NEAR TERM...HEWITT/KHW SHORT TERM...DUDA LONG TERM...OKULSKI AVIATION...HEWITT/KHW MARINE...HEWITT/KHW/DUDA HYDROLOGY...HEWITT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1134 AM EDT WED JUN 27 2012 .SYNOPSIS... HIGH PRESSURE CROSSING THE AREA WILL ALLOW FOR DRY WEATHER TO CONTINUE THROUGH THURSDAY WITH WITH TEMPERATURES WARMING EACH DAY. HIGH PRESSURE ALOFT WILL BRING HOT AND HUMID CONDITIONS ALONG WITH THE CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA BY THE END OF THE WEEK. && .NEAR TERM /THROUGH THURSDAY/... THE LATEST RUC MID-LEVEL ANALYSIS INDICATES AN UPPER VORTEX CENTERED ACROSS MAINE WITH DEEP RIDGING BUILDING INTO THE MISSOURI VALLEY. AT THE SURFACE, HIGH PRESSURE IS CENTERED ACROSS THE OHIO VALLEY. WITH RELATIVELY DRY AIR ALOFT, CLEAR SKIES ARE PREVAILING ACROSS THE AREA. HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN TODAY AS THE UPPER LEVEL RIDGE ACROSS THE MISSOURI VALLEY SLOWLY MOVES TOWARDS THE AREA. THE AREA WILL STILL BE IN A NORTHWESTERLY MID-LEVEL FLOW, ALLOWING FOR SOME DIURNAL CUMULUS TO DEVELOP THIS AFTERNOON. LIMITED LOW-LEVEL MOISTURE SHOULD ONLY ALLOW FEW-SCT COVERAGE TODAY WITH MOST CLOUDS NORTHWEST OF PITTSBURGH AS A MID DECK ADVECTS IN FROM THE NORTH. THE LOW- LEVEL FLOW WILL SLOWLY SHIFT TO MORE WESTERLY TODAY, WITH WARM AIR ADVECTION. MODEL CONSENSUS INDICATES 850 TEMPS INCREASING TO 14-15C BY THIS AFTERNOON. TEMP TODAY ARE A FEW DEGREES WARMER THAN THE LAMP, CLOSE TO SEASONAL NORMS WITH HIGHS RANGING FROM THE MID TO UPPER 70S ACROSS THE EASTERN RIDGES AND I-80 CORRIDOR TO THE MID 80S FOR LOCATIONS SOUTH AND WEST OF PITTSBURGH. TONIGHT INTO THURSDAY...THE SURFACE HIGH WILL SLIDE SOUTHWARD INTO THE GULF WITH THE DEEP RIDGE BUILDING INTO THE TENNESSEE VALLEY. THIS WILL PUT THE UPPER OHIO VALLEY ON THE NORTHEASTERN PERIPHERY OF THE RIDGE WITH THE MID-LEVEL FLOW BACKING TO MORE NORTHWESTERLY AS WARM AIR ADVECTION CONTINUES. LOWS TONIGHT ARE A MAV/MET BLEND, RANGING FROM THE LOWER 60S IN EASTERN OHIO TO THE MID 50S ALONG THE I-80 CORRIDOR. RIDGE TOPS WILL BE NOTICEABLY WARMER AS AN INVERSION SETS UP OVERNIGHT. MODEL DISAGREEMENT WITH THE THERMAL PROFILE IN THE LOWER LEVELS THAT HAS BEEN THE STORY FOR SEVERAL DAYS CONTINUES, WITH THE NAM/ECMWF INDICATING 850 TEMP INCREASING TO 20-22C AND GFS/GFSE AT 18-19C. ANOTHER DIFFERENCE THAT ADDS UNCERTAINTY TO THIS FORECAST IS THE MOISTURE PROFILE, WITH RECENT OBSERVATIONS INDICATING THE GFS IS TOO WARM WITH DEW POINTS. THUS, FORECAST IS A GFS/ECMWF BLEND WITH HIGHS ON THURSDAY RANGING FROM THE LOWER 90S ACROSS EASTERN OHIO TO THE MID 80S ACROSS THE I-80 CORRIDOR. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/... MODELS ARE SHOWING ACTIVITY DEVELOPING WITH THE UL WAVE THU NIGHT, WITH THE NAM SHOWING A SFC REFLECTION MOVING THROUGH. WILL GO WITH SCHC/LOW CHC POPS THU NIGHT WITH THIS FEATURE. MODELS ARE STILL SHOWING A RELATIVELY DRY ATMOSPHERE AND, WITH THE PASSAGE AT NIGHT, EXPECT ACTIVITY TO DIMINISH AS IT MOVES SOUTHEASTWARD. A WEAK SFC FRONT WILL CROSS THE AREA WITH THE WAVE THU NIGHT AND MOVE SOUTH ON FRIDAY MORNING. AT THIS POINT, HAVE LOW CONFIDENCE ON SHOWER/STORM DEVELOPMENT AS THERE ARE DISCREPANCIES IN MODEL SOLUTIONS ON POSITION OF FRONT AND ANOTHER UL WAVE THAT WILL MOVE THROUGH FRIDAY. FOR CURRENT FORECAST WILL GO WITH SCHC/LOW CHC POPS. TEMPS WILL INCREASE DAILY, WITH A NOTICEABLE INCREASE IN HUMIDITY BY FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE MODELS ARE FORECASTING DEVELOPMENT OF A BROAD TROUGH ACROSS THE GREAT LAKES AND NORTHEAST U.S. THIS WEEKEND. SHORTWAVE RIDGING IN ADVANCE OF DISTURBANCES IN NEAR ZONAL FLOW OVER THE UPR OH REGION SHOULD TAP SOUTHERN WARMTH SUFFICIENTLY TO MAINTAIN A WARM TEMPERATURE FORECAST THROUGH THE EXTENDED PERIOD. AS TIMING OF DISTURBANCES IN FLOW IS QUESTIONABLE AT THIS STAGE OF THE FORECAST...WL MAINTAIN CHANCE/NR CLIMO POPS INTO EARLY NEXT WEEK. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... VFR WILL CONTINUE THROUGH TONIGHT, AS SURFACE HIGH PRESSURE BUILDS UNDER NORTHWEST FLOW ALOFT. NORTHWEST WINDS SHOULD GUST NO HIGHER THAN 15-20 KTS AND THEN SUBSIDE WITH DECOUPLING THIS EVENING. OUTLOOK...THURSDAY THROUGH SUNDAY... EXPECT PREVALENT VFR, BUT AREAS OF MORNING FOG AND HAZE CAN DEVELOP BY THE WEEKEND AS LOW LEVEL MOISTURE INCREASES. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH POSSIBLE RESTRICTIONS MAY OCCUR AS A SERIES OF UPPER DISTURBANCES CROSS THE REGION. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
700 PM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY...NE WINDS ON BACKSIDE OF SLOWLY DEPARTING INVERTED TROUGH HAVE BEEN THE ONLY STORY IN AN OTHERWISE BEAUTIFUL EARLY SUMMER DAY. LARGE EXPANSE OF CIRRUS/CIRROSTRATUS ASSOCIATED WITH TROPICAL DEPRESSION DEBBY CONTINUES TO PULL SLOWLY AWAY TO THE SOUTHEAST...LEAVING NEARLY CLOUDLESS SKY CONDITIONS ACROSS THE AREA. CLEAR SKY CONDITIONS WILL PERSIST THROUGH THE NIGHT...AND AS WINDS SLOWLY EASE DUE TO WEAKENING OF PRESSURE GRADIENT...NEARLY IDEAL RADIATIONAL COOLING WILL DEVELOP TONIGHT. WINDS WILL CONTINUE TO GUST UP TO 20 MPH NEAR THE COAST BEFORE EASING QUICKLY WITH LOSS OF HEATING AND THE DEVELOPMENT OF THE NOCTURNAL INVERSION. EXPECT FULL DECOUPLING OF WINDS SHORTLY AFTER NIGHTFALL...AND TEMPS WILL FALL RAPIDLY IN THE DRY COLUMN AFTER DARK. DURING THE NIGHT...MID LEVEL HIGH PUSHES EAST HELPING RAISE 850MB TEMPS 4-6C OVERNIGHT. THIS WILL ACT AS THE LIMITING FACTOR TO COOLING SINCE SURFACE TEMPS...EVEN THOUGH BELOW A STEEP INVERSION...WILL BE FORCED TO RISE AS WELL. THE COOLEST TEMPS MAY BE FELT A FEW HOURS AFTER MIDNIGHT BEFORE LEVELING OFF...OR EVEN RISING SLIGHTLY TOWARDS MORNING. STILL...HAVE LEANED MORE TOWARDS THE COOLER MAV GUIDANCE WITH TEMPS A DEGREE OR TWO ABOVE 60...EXCEPT UPPER 50S IN THE COOLEST POCOSIN SWAMPS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...HIGH PRESSURE ALOFT WILL BUILD IN THROUGH THE PERIOD...BRINGING WITH IT INCREASING HEAT AND HUMIDITY. UNDER MAINLY CLEAR SKIES...MAX TEMPERATURES ARE EXPECTED TO REACH THE UPPER 80S TO LOWER 90S...PERHAPS MID 90S WELL INLAND ON THURSDAY. FRIDAY WILL SEE TEMPERATURES RANGE FROM THE MID 90S TO AROUND 100 DEGREES. ON THURSDAY...MOISTURE WILL BE LACKING SUCH THAT APPARENT TEMPERATURES MAY ACTUALLY BE LOWER THAN THE ACTUAL TEMPERATURES. FRIDAY WILL BE A DIFFERENT STORY THOUGH AS DEWPOINTS RECOVER INTO THE 70 TO 75 DEGREE RANGE. WHILE DEWPOINT TEMPERATURES COULD FALL DUE TO MIXING DURING THE AFTERNOON...THERE COULD BE A PERIOD OF 2 OR THREE HOURS WHERE TEMPERATURES AND DEWPOINTS COMBINE TO YIELD APPARENT TEMPERATURES AROUND 105 DEGREES. MINS THURSDAY NIGHT WILL BE WITHIN A COUPLE DEGREES OF 70 WHILE MINS FRIDAY NIGHT SHOULD BE IN THE MID TO UPPER 70S. IT SHOULD BE NOTED THAT THERE WILL BE A PIEDMONT TROUGH AND SEA BREEZE FRONT PRESENT BOTH DAYS. THERE COULD BE ENOUGH LIFT ASSOCIATED WITH THESE FEATURES TO PRODUCE A FEW CLOUDS DESPITE STRONG RIDGING ALOFT...ESPECIALLY FRIDAY WHERE LOW LEVEL MOISTURE WILL BE THE GREATEST. ON FRIDAY...IT IS POSSIBLE THAT A STRAY THUNDERSTORM COULD FORM ALONG THESE FEATURES...ESPECIALLY THE SEA BREEZE WHERE LOW LEVEL MOISTURE WOULD BE MOST ABUNDANT. POPS ARE BASICALLY 0 THURSDAY AND 10 PERCENT OR LESS FRIDAY. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 PM WEDNESDAY...SIZZLING DAYTIME TEMPERATURES AND ASPHALT MIRAGES WILL BE OBSERVED THIS WEEKEND AS INTENSE HEAT TAKES HOLD OF THE AREA...AS A MAMMOTH RIDGE ALOFT BARRELS SLOWLY EAST INTO THE CAROLINAS. AN EXCESSIVE HEAT WATCH WAS ISSUED TO ADDRESS THE HEAT INDEX VALUES BETWEEN 102-112 FRI AND SAT. AT A MINIMUM OVER THE WEEKEND HEAT ADVISORIES WILL BE NEEDED FOR H.I. VALUES OVER 105 DEGREES...AND POSSIBLY A WARNING IN SOME LOCATIONS SATURDAY AS INDEX VALUES NEAR OR EXCEED 110 DEGREES. HEAT ADVISORIES OR WARNINGS MAY BE NEEDED BEYOND SATURDAY...BUT THE WATCH TIME FOR NOW IS VALID THROUGH SATURDAY AFTERNOON MAINLY DUE TO THE NATURAL INCREASE IN UNCERTAINTY IN THE EXTENDED. IF YOU BELIEVE IN THE ECMWF...WE COULD HAVE AN EXTENDED HEAT WAVE WELL INTO NEXT WEEK. RECORD HIGHS AT ILM...FRIDAY 101 (1959) SATURDAY 100 (1959) SUNDAY 98 (1990) MONDAY 97 (1980). RECORD HIGHS AT FLO...FRIDAY 101 (1998) SATURDAY 103 (1990) SUNDAY 101 (1990) MONDAY 102 (1954). AT THE SURFACE AN AMPLIFIED THERMAL-TROUGH AXIS WILL RESIDE OVER THE FAR INTERIOR AND SANDHILLS. THIS SHOULD SUSTAIN SW WIND FLOW OVER THE AREA THROUGH THE EXTENDED PERIOD. LARGE LAND VS SEA TEMP DIFFERENTIAL SHOULD DRIVE A ROBUST SEA BREEZE CIRCULATION...AND AFTERNOON GUSTS TO 20 KT ALONG THE COAST CAN BE EXPECTED EACH AFTERNOON TO EARLY EVENING. THE REMNANTS OF DEBBY WILL PASS WELL E AND NE OF THE COAST OVER THE WEEKEND AND INTO THE CANADIAN MARITIME BY DAYBREAK WEDNESDAY WITH LITTLE TO NO IMPACT HERE...EXPECT POTENTIALLY INCREASING THE RIP THREAT...BUT EVEN THIS WILL REMAIN LIMITED IN LOCAL IMPACT. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AS OF 00Z...VFR CONDITIONS EXPECTED THROUGH THE END OF THE FORECAST PERIOD. A BROAD UPPER RIDGE WITH VERY DRY AIR ALOFT WILL MOVE INTO THE REGION OVER THE NEXT 24 HOURS. OVERNIGHT...MOISTURE PROFILES CONTINUE TO BE DRY BELOW 850 MB...NO FOG. LIGHT WINDS OVERNIGHT WILL GIVE WAY TO A SOUTHWESTERLY COMPONENT THURSDAY AS A SURFACE HIGH CENTERED OVER FLORIDA DOMINATES THE WEATHER. THE COASTAL TERMINALS WILL LIKELY SEE A SOUTH SOUTHWEST RESULTANT IN THE AFTERNOON...PERHAPS WITH GUSTY WINDS AT THE MYRTLES. EXTENDED OUTLOOK...EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 524 PM WEDNESDAY...SMALL CRAFT ADVISORY FOR THE ILM NC WATERS HAS BEEN DOWNGRADED TO A SMALL CRAFT EXERCISE CAUTION...GOOD THROUGH 8 PM WEDNESDAY. LATEST BUOY OBS AND HRRR TRENDS CONTINUE WITH NE WINDS 15 TO OCCASIONALLY 20 KT AND SEAS 2 TO 4 FT...EXCEPT UP TO 5 FT ACROSS THE OUTER WATERS OFF CAPE FEAR...THROUGH 8 PM WEDNESDAY. SMALL CRAFT ADVISORY FOR THE ILM SC WATERS CONTINUES THROUGH 8 PM. PREVIOUS DISCUSSION................................................ AS OF 300 PM WEDNESDAY...INVERTED TROUGH EXTENDING NORTH FROM TROPICAL DEPRESSION DEBBY...NOW LOCATED OFF THE FLORIDA ATLANTIC COAST...IS CONTINUING TO BE STRONGER THAN GUIDANCE HAS BEEN ADVERTISING. LATEST MSAS ANALYSIS SHOWS THE TROUGH WEAKENING VERY SLOWLY...AND HRRR BEST REPRESENTS LATEST TRENDS. STILL EXPECT THIS TROUGH TO BREAK DOWN AS DEBBY PULLS OFF TO THE EAST...ALLOWING WINDS TO EASE AND SEAS TO THEN FALL. WITH THE TROUGH REMAINING STRONGER THAN CURRENT PROGS WINDS AND SEAS ARE RUNNING HIGHER THAN EARLIER FORECASTS ATTM...SO HAVE ENHANCED BOTH...AND EXTENDED THE SMALL CRAFT ADVISORY FOR AMZ256 AND AMZ254 UNTIL 8PM. AS WINDS DECAY TONIGHT...SEAS WILL FALL SLOWLY...BECOMING 2-4 FT OVERNIGHT WITH N/NE WINDS LESS THAN 10 KTS. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...EXPECT SW FLOW OF 15 KT OR LESS THROUGH FRIDAY EVENING BEFORE WINDS SHIFT TO THE NW AND BECOME LIGHT FRIDAY NIGHT. SEAS HEIGHTS OF 2 TO 4 FEET ARE EXPECTED THROUGH THE PERIOD. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 3 PM WEDNESDAY...NO MAJOR HAZARDS ANTICIPATED ALTHOUGH AIR TEMPS WILL BE VERY HOT THIS WEEKEND AND PLENTY FRESH WATER WILL BE CRUCIAL FOR BOATING AND RECREATIONAL EXCURSIONS. SEAS WILL LIKELY HOLD 4 FEET OR LESS SATURDAY THROUGH MONDAY...ALTHOUGH GROWING SE WAVES OF 4-5 FEET MAY BE OBSERVED OVER THE FAR OUTER WATERS AS DEBBY PASSES WELL E OF THE COAST. EACH AFTERNOON THE SEA BREEZE WILL BRING S-SW WIND GUSTS TO 20 KT DUE TO THE STRONG LAND VS SEA-SFC TEMPERATURE DIFFERENCE. THE SEA SPECTRUM SAT-MON WILL BE COMPRISED OF SE WAVES 2-3 FT AT 7-9 SECONDS...AND SW WAVES 1-2 FT AT 4-5 SECONDS DRIVEN MAINLY BY LOCAL WINDS. TSTMS IF ANY WILL REMAIN ISOLATED...AND MAINLY ON LAND IN THE LATE AFTERNOONS AND WELL OFFSHORE AT NIGHT. PRESSURE PATTERN SAT-MON WILL FOSTER SW WINDS 10-15 KT...HIGHER GUSTS BETWEEN 3PM-7PM IN-SHORE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR SCZ017-023-024-032-033-039-053>056. NC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR NCZ087-096-099-105>110. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ254- 256. && $$ SYNOPSIS... NEAR TERM...DCH/JDW SHORT TERM...31 LONG TERM...MJC AVIATION...43
AREA FORECAST DISCUSSION...UPDATE TO MARINE
NWS WILMINGTON NC
524 PM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY...NE WINDS ON BACKSIDE OF SLOWLY DEPARTING INVERTED TROUGH HAVE BEEN THE ONLY STORY IN AN OTHERWISE BEAUTIFUL EARLY SUMMER DAY. LARGE EXPANSE OF CIRRUS/CIRROSTRATUS ASSOCIATED WITH TROPICAL DEPRESSION DEBBY CONTINUES TO PULL SLOWLY AWAY TO THE SOUTHEAST...LEAVING NEARLY CLOUDLESS SKY CONDITIONS ACROSS THE AREA. CLEAR SKY CONDITIONS WILL PERSIST THROUGH THE NIGHT...AND AS WINDS SLOWLY EASE DUE TO WEAKENING OF PRESSURE GRADIENT...NEARLY IDEAL RADIATIONAL COOLING WILL DEVELOP TONIGHT. WINDS WILL CONTINUE TO GUST UP TO 20 MPH NEAR THE COAST BEFORE EASING QUICKLY WITH LOSS OF HEATING AND THE DEVELOPMENT OF THE NOCTURNAL INVERSION. EXPECT FULL DECOUPLING OF WINDS SHORTLY AFTER NIGHTFALL...AND TEMPS WILL FALL RAPIDLY IN THE DRY COLUMN AFTER DARK. DURING THE NIGHT...MID LEVEL HIGH PUSHES EAST HELPING RAISE 850MB TEMPS 4-6C OVERNIGHT. THIS WILL ACT AS THE LIMITING FACTOR TO COOLING SINCE SURFACE TEMPS...EVEN THOUGH BELOW A STEEP INVERSION...WILL BE FORCED TO RISE AS WELL. THE COOLEST TEMPS MAY BE FELT A FEW HOURS AFTER MIDNIGHT BEFORE LEVELING OFF...OR EVEN RISING SLIGHTLY TOWARDS MORNING. STILL...HAVE LEANED MORE TOWARDS THE COOLER MAV GUIDANCE WITH TEMPS A DEGREE OR TWO ABOVE 60...EXCEPT UPPER 50S IN THE COOLEST POCOSIN SWAMPS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...HIGH PRESSURE ALOFT WILL BUILD IN THROUGH THE PERIOD...BRINGING WITH IT INCREASING HEAT AND HUMIDITY. UNDER MAINLY CLEAR SKIES...MAX TEMPERATURES ARE EXPECTED TO REACH THE UPPER 80S TO LOWER 90S...PERHAPS MID 90S WELL INLAND ON THURSDAY. FRIDAY WILL SEE TEMPERATURES RANGE FROM THE MID 90S TO AROUND 100 DEGREES. ON THURSDAY...MOISTURE WILL BE LACKING SUCH THAT APPARENT TEMPERATURES MAY ACTUALLY BE LOWER THAN THE ACTUAL TEMPERATURES. FRIDAY WILL BE A DIFFERENT STORY THOUGH AS DEWPOINTS RECOVER INTO THE 70 TO 75 DEGREE RANGE. WHILE DEWPOINT TEMPERATURES COULD FALL DUE TO MIXING DURING THE AFTERNOON...THERE COULD BE A PERIOD OF 2 OR THREE HOURS WHERE TEMPERATURES AND DEWPOINTS COMBINE TO YIELD APPARENT TEMPERATURES AROUND 105 DEGREES. MINS THURSDAY NIGHT WILL BE WITHIN A COUPLE DEGREES OF 70 WHILE MINS FRIDAY NIGHT SHOULD BE IN THE MID TO UPPER 70S. IT SHOULD BE NOTED THAT THERE WILL BE A PIEDMONT TROUGH AND SEA BREEZE FRONT PRESENT BOTH DAYS. THERE COULD BE ENOUGH LIFT ASSOCIATED WITH THESE FEATURES TO PRODUCE A FEW CLOUDS DESPITE STRONG RIDGING ALOFT...ESPECIALLY FRIDAY WHERE LOW LEVEL MOISTURE WILL BE THE GREATEST. ON FRIDAY...IT IS POSSIBLE THAT A STRAY THUNDERSTORM COULD FORM ALONG THESE FEATURES...ESPECIALLY THE SEA BREEZE WHERE LOW LEVEL MOISTURE WOULD BE MOST ABUNDANT. POPS ARE BASICALLY 0 THURSDAY AND 10 PERCENT OR LESS FRIDAY. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 PM WEDNESDAY...SIZZLING DAYTIME TEMPERATURES AND ASPHALT MIRAGES WILL BE OBSERVED THIS WEEKEND AS INTENSE HEAT TAKES HOLD OF THE AREA...AS A MAMMOTH RIDGE ALOFT BARRELS SLOWLY EAST INTO THE CAROLINAS. AN EXCESSIVE HEAT WATCH WAS ISSUED TO ADDRESS THE HEAT INDEX VALUES BETWEEN 102-112 FRI AND SAT. AT A MINIMUM OVER THE WEEKEND HEAT ADVISORIES WILL BE NEEDED FOR H.I. VALUES OVER 105 DEGREES...AND POSSIBLY A WARNING IN SOME LOCATIONS SATURDAY AS INDEX VALUES NEAR OR EXCEED 110 DEGREES. HEAT ADVISORIES OR WARNINGS MAY BE NEEDED BEYOND SATURDAY...BUT THE WATCH TIME FOR NOW IS VALID THROUGH SATURDAY AFTERNOON MAINLY DUE TO THE NATURAL INCREASE IN UNCERTAINTY IN THE EXTENDED. IF YOU BELIEVE IN THE ECMWF...WE COULD HAVE AN EXTENDED HEAT WAVE WELL INTO NEXT WEEK. RECORD HIGHS AT ILM...FRIDAY 101 (1959) SATURDAY 100 (1959) SUNDAY 98 (1990) MONDAY 97 (1980). RECORD HIGHS AT FLO...FRIDAY 101 (1998) SATURDAY 103 (1990) SUNDAY 101 (1990) MONDAY 102 (1954). AT THE SURFACE AN AMPLIFIED THERMAL-TROUGH AXIS WILL RESIDE OVER THE FAR INTERIOR AND SANDHILLS. THIS SHOULD SUSTAIN SW WIND FLOW OVER THE AREA THROUGH THE EXTENDED PERIOD. LARGE LAND VS SEA TEMP DIFFERENTIAL SHOULD DRIVE A ROBUST SEA BREEZE CIRCULATION...AND AFTERNOON GUSTS TO 20 KT ALONG THE COAST CAN BE EXPECTED EACH AFTERNOON TO EARLY EVENING. THE REMNANTS OF DEBBY WILL PASS WELL E AND NE OF THE COAST OVER THE WEEKEND AND INTO THE CANADIAN MARITIME BY DAYBREAK WEDNESDAY WITH LITTLE TO NO IMPACT HERE...EXPECT POTENTIALLY INCREASING THE RIP THREAT...BUT EVEN THIS WILL REMAIN LIMITED IN LOCAL IMPACT. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...EXPECT VFR THROUGH VALID PERIOD AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. WITH NEARLY CLEAR SKIES...NORTHEAST WINDS WILL CONTINUE TO GUST TO AROUND 20 KTS...ESPECIALLY NEAR THE COAST...DUE TO A PINCHED GRADIENT NEAR A SURFACE TROUGH JUST OFFSHORE. TOWARDS SUNSET...GUSTS WILL SUBSIDE AND SUSTAINED WINDS WILL DECREASE...WITH LIGHT AND VARIABLE WINDS THROUGH MORNING. AFTER DAYBREAK ON THURSDAY...WINDS WILL BECOME SOUTHWEST WITH SUSTAINED WINDS AOB 10 KTS. EXTENDED OUTLOOK...EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 524 PM WEDNESDAY...SMALL CRAFT ADVISORY FOR THE ILM NC WATERS HAS BEEN DOWNGRADED TO A SMALL CRAFT EXERCISE CAUTION...GOOD THROUGH 8 PM WEDNESDAY. LATEST BUOY OBS AND HRRR TRENDS CONTINUE WITH NE WINDS 15 TO OCCASIONALLY 20 KT AND SEAS 2 TO 4 FT...EXCEPT UP TO 5 FT ACROSS THE OUTER WATERS OFF CAPE FEAR...THROUGH 8 PM WEDNESDAY. SMALL CRAFT ADVISORY FOR THE ILM SC WATERS CONTINUES THROUGH 8 PM. PREVIOUS DISCUSSION................................................ AS OF 300 PM WEDNESDAY...INVERTED TROUGH EXTENDING NORTH FROM TROPICAL DEPRESSION DEBBY...NOW LOCATED OFF THE FLORIDA ATLANTIC COAST...IS CONTINUING TO BE STRONGER THAN GUIDANCE HAS BEEN ADVERTISING. LATEST MSAS ANALYSIS SHOWS THE TROUGH WEAKENING VERY SLOWLY...AND HRRR BEST REPRESENTS LATEST TRENDS. STILL EXPECT THIS TROUGH TO BREAK DOWN AS DEBBY PULLS OFF TO THE EAST...ALLOWING WINDS TO EASE AND SEAS TO THEN FALL. WITH THE TROUGH REMAINING STRONGER THAN CURRENT PROGS WINDS AND SEAS ARE RUNNING HIGHER THAN EARLIER FORECASTS ATTM...SO HAVE ENHANCED BOTH...AND EXTENDED THE SMALL CRAFT ADVISORY FOR AMZ256 AND AMZ254 UNTIL 8PM. AS WINDS DECAY TONIGHT...SEAS WILL FALL SLOWLY...BECOMING 2-4 FT OVERNIGHT WITH N/NE WINDS LESS THAN 10 KTS. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...EXPECT SW FLOW OF 15 KT OR LESS THROUGH FRIDAY EVENING BEFORE WINDS SHIFT TO THE NW AND BECOME LIGHT FRIDAY NIGHT. SEAS HEIGHTS OF 2 TO 4 FEET ARE EXPECTED THROUGH THE PERIOD. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 3 PM WEDNESDAY...NO MAJOR HAZARDS ANTICIPATED ALTHOUGH AIR TEMPS WILL BE VERY HOT THIS WEEKEND AND PLENTY FRESH WATER WILL BE CRUCIAL FOR BOATING AND RECREATIONAL EXCURSIONS. SEAS WILL LIKELY HOLD 4 FEET OR LESS SATURDAY THROUGH MONDAY...ALTHOUGH GROWING SE WAVES OF 4-5 FEET MAY BE OBSERVED OVER THE FAR OUTER WATERS AS DEBBY PASSES WELL E OF THE COAST. EACH AFTERNOON THE SEA BREEZE WILL BRING S-SW WIND GUSTS TO 20 KT DUE TO THE STRONG LAND VS SEA-SFC TEMPERATURE DIFFERENCE. THE SEA SPECTRUM SAT-MON WILL BE COMPRISED OF SE WAVES 2-3 FT AT 7-9 SECONDS...AND SW WAVES 1-2 FT AT 4-5 SECONDS DRIVEN MAINLY BY LOCAL WINDS. TSTMS IF ANY WILL REMAIN ISOLATED...AND MAINLY ON LAND IN THE LATE AFTERNOONS AND WELL OFFSHORE AT NIGHT. PRESSURE PATTERN SAT-MON WILL FOSTER SW WINDS 10-15 KT...HIGHER GUSTS BETWEEN 3PM-7PM IN-SHORE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR SCZ017-023-024-032-033-039-053>056. NC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR NCZ087-096-099-105>110. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ254- 256. && $$ SYNOPSIS... NEAR TERM...DCH/JDW SHORT TERM...31 LONG TERM...MJC AVIATION...JDW/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
304 PM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY...NE WINDS ON BACKSIDE OF SLOWLY DEPARTING INVERTED TROUGH HAVE BEEN THE ONLY STORY IN AN OTHERWISE BEAUTIFUL EARLY SUMMER DAY. LARGE EXPANSE OF CIRRUS/CIRROSTRATUS ASSOCIATED WITH TROPICAL DEPRESSION DEBBY CONTINUES TO PULL SLOWLY AWAY TO THE SOUTHEAST...LEAVING NEARLY CLOUDLESS SKY CONDITIONS ACROSS THE AREA. CLEAR SKY CONDITIONS WILL PERSIST THROUGH THE NIGHT...AND AS WINDS SLOWLY EASE DUE TO WEAKENING OF PRESSURE GRADIENT...NEARLY IDEAL RADIATIONAL COOLING WILL DEVELOP TONIGHT. WINDS WILL CONTINUE TO GUST UP TO 20 MPH NEAR THE COAST BEFORE EASING QUICKLY WITH LOSS OF HEATING AND THE DEVELOPMENT OF THE NOCTURNAL INVERSION. EXPECT FULL DECOUPLING OF WINDS SHORTLY AFTER NIGHTFALL...AND TEMPS WILL FALL RAPIDLY IN THE DRY COLUMN AFTER DARK. DURING THE NIGHT...MID LEVEL HIGH PUSHES EAST HELPING RAISE 850MB TEMPS 4-6C OVERNIGHT. THIS WILL ACT AS THE LIMITING FACTOR TO COOLING SINCE SURFACE TEMPS...EVEN THOUGH BELOW A STEEP INVERSION...WILL BE FORCED TO RISE AS WELL. THE COOLEST TEMPS MAY BE FELT A FEW HOURS AFTER MIDNIGHT BEFORE LEVELING OFF...OR EVEN RISING SLIGHTLY TOWARDS MORNING. STILL...HAVE LEANED MORE TOWARDS THE COOLER MAV GUIDANCE WITH TEMPS A DEGREE OR TWO ABOVE 60...EXCEPT UPPER 50S IN THE COOLEST POCOSIN SWAMPS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...HIGH PRESSURE ALOFT WILL BUILD IN THROUGH THE PERIOD...BRINGING WITH IT INCREASING HEAT AND HUMIDITY. UNDER MAINLY CLEAR SKIES...MAX TEMPERATURES ARE EXPECTED TO REACH THE UPPER 80S TO LOWER 90S...PERHAPS MID 90S WELL INLAND ON THURSDAY. FRIDAY WILL SEE TEMPERATURES RANGE FROM THE MID 90S TO AROUND 100 DEGREES. ON THURSDAY...MOISTURE WILL BE LACKING SUCH THAT APPARENT TEMPERATURES MAY ACTUALLY BE LOWER THAN THE ACTUAL TEMPERATURES. FRIDAY WILL BE A DIFFERENT STORY THOUGH AS DEWPOINTS RECOVER INTO THE 70 TO 75 DEGREE RANGE. WHILE DEWPOINT TEMPERATURES COULD FALL DUE TO MIXING DURING THE AFTERNOON...THERE COULD BE A PERIOD OF 2 OR THREE HOURS WHERE TEMPERATURES AND DEWPOINTS COMBINE TO YIELD APPARENT TEMPERATURES AROUND 105 DEGREES. MINS THURSDAY NIGHT WILL BE WITHIN A COUPLE DEGREES OF 70 WHILE MINS FRIDAY NIGHT SHOULD BE IN THE MID TO UPPER 70S. IT SHOULD BE NOTED THAT THERE WILL BE A PIEDMONT TROUGH AND SEA BREEZE FRONT PRESENT BOTH DAYS. THERE COULD BE ENOUGH LIFT ASSOCIATED WITH THESE FEATURES TO PRODUCE A FEW CLOUDS DESPITE STRONG RIDGING ALOFT...ESPECIALLY FRIDAY WHERE LOW LEVEL MOISTURE WILL BE THE GREATEST. ON FRIDAY...IT IS POSSIBLE THAT A STRAY THUNDERSTORM COULD FORM ALONG THESE FEATURES...ESPECIALLY THE SEA BREEZE WHERE LOW LEVEL MOISTURE WOULD BE MOST ABUNDANT. POPS ARE BASICALLY 0 THURSDAY AND 10 PERCENT OR LESS FRIDAY. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 PM WEDNESDAY...SIZZLING DAYTIME TEMPERATURES AND ASPHALT MIRAGES WILL BE OBSERVED THIS WEEKEND AS INTENSE HEAT TAKES HOLD OF THE AREA...AS A MAMMOTH RIDGE ALOFT BARRELS SLOWLY EAST INTO THE CAROLINAS. AN EXCESSIVE HEAT WATCH WAS ISSUED TO ADDRESS THE HEAT INDEX VALUES BETWEEN 102-112 FRI AND SAT. AT A MINIMUM OVER THE WEEKEND HEAT ADVISORIES WILL BE NEEDED FOR H.I. VALUES OVER 105 DEGREES...AND POSSIBLY A WARNING IN SOME LOCATIONS SATURDAY AS INDEX VALUES NEAR OR EXCEED 110 DEGREES. HEAT ADVISORIES OR WARNINGS MAY BE NEEDED BEYOND SATURDAY...BUT THE WATCH TIME FOR NOW IS VALID THROUGH SATURDAY AFTERNOON MAINLY DUE TO THE NATURAL INCREASE IN UNCERTAINTY IN THE EXTENDED. IF YOU BELIEVE IN THE ECMWF...WE COULD HAVE AN EXTENDED HEAT WAVE WELL INTO NEXT WEEK. RECORD HIGHS AT ILM...FRIDAY 101 (1959) SATURDAY 100 (1959) SUNDAY 98 (1990) MONDAY 97 (1980). RECORD HIGHS AT FLO...FRIDAY 101 (1998) SATURDAY 103 (1990) SUNDAY 101 (1990) MONDAY 102 (1954). AT THE SURFACE AN AMPLIFIED THERMAL-TROUGH AXIS WILL RESIDE OVER THE FAR INTERIOR AND SANDHILLS. THIS SHOULD SUSTAIN SW WIND FLOW OVER THE AREA THROUGH THE EXTENDED PERIOD. LARGE LAND VS SEA TEMP DIFFERENTIAL SHOULD DRIVE A ROBUST SEA BREEZE CIRCULATION...AND AFTERNOON GUSTS TO 20 KT ALONG THE COAST CAN BE EXPECTED EACH AFTERNOON TO EARLY EVENING. THE REMNANTS OF DEBBY WILL PASS WELL E AND NE OF THE COAST OVER THE WEEKEND AND INTO THE CANADIAN MARITIME BY DAYBREAK WEDNESDAY WITH LITTLE TO NO IMPACT HERE...EXPECT POTENTIALLY INCREASING THE RIP THREAT...BUT EVEN THIS WILL REMAIN LIMITED IN LOCAL IMPACT. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...EXPECT VFR THROUGH VALID PERIOD AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. WITH NEARLY CLEAR SKIES...NORTHEAST WINDS WILL CONTINUE TO GUST TO AROUND 20 KTS...ESPECIALLY NEAR THE COAST...DUE TO A PINCHED GRADIENT NEAR A SURFACE TROUGH JUST OFFSHORE. TOWARDS SUNSET...GUSTS WILL SUBSIDE AND SUSTAINED WINDS WILL DECREASE...WITH LIGHT AND VARIABLE WINDS THROUGH MORNING. AFTER DAYBREAK ON THURSDAY...WINDS WILL BECOME SOUTHWEST WITH SUSTAINED WINDS AOB 10 KTS. EXTENDED OUTLOOK...EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY...INVERTED TROUGH EXTENDING NORTH FROM TROPICAL DEPRESSION DEBBY...NOW LOCATED OFF THE FLORIDA ATLANTIC COAST...IS CONTINUING TO BE STRONGER THAN GUIDANCE HAS BEEN ADVERTISING. LATEST MSAS ANALYSIS SHOWS THE TROUGH WEAKENING VERY SLOWLY...AND HRRR BEST REPRESENTS LATEST TRENDS. STILL EXPECT THIS TROUGH TO BREAK DOWN AS DEBBY PULLS OFF TO THE EAST...ALLOWING WINDS TO EASE AND SEAS TO THEN FALL. WITH THE TROUGH REMAINING STRONGER THAN CURRENT PROGS WINDS AND SEAS ARE RUNNING HIGHER THAN EARLIER FORECASTS ATTM...SO HAVE ENHANCED BOTH...AND EXTENDED THE SMALL CRAFT ADVISORY FOR AMZ256 AND AMZ254 UNTIL 8PM. AS WINDS DECAY TONIGHT...SEAS WILL FALL SLOWLY...BECOMING 2-4 FT OVERNIGHT WITH N/NE WINDS LESS THAN 10 KTS. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...EXPECT SW FLOW OF 15 KT OR LESS THROUGH FRIDAY EVENING BEFORE WINDS SHIFT TO THE NW AND BECOME LIGHT FRIDAY NIGHT. SEAS HEIGHTS OF 2 TO 4 FEET ARE EXPECTED THROUGH THE PERIOD. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 3 PM WEDNESDAY...NO MAJOR HAZARDS ANTICIPATED ALTHOUGH AIR TEMPS WILL BE VERY HOT THIS WEEKEND AND PLENTY FRESH WATER WILL BE CRUCIAL FOR BOATING AND RECREATIONAL EXCURSIONS. SEAS WILL LIKELY HOLD 4 FEET OR LESS SATURDAY THROUGH MONDAY...ALTHOUGH GROWING SE WAVES OF 4-5 FEET MAY BE OBSERVED OVER THE FAR OUTER WATERS AS DEBBY PASSES WELL E OF THE COAST. EACH AFTERNOON THE SEA BREEZE WILL BRING S-SW WIND GUSTS TO 20 KT DUE TO THE STRONG LAND VS SEA-SFC TEMPERATURE DIFFERENCE. THE SEA SPECTRUM SAT-MON WILL BE COMPRISED OF SE WAVES 2-3 FT AT 7-9 SECONDS...AND SW WAVES 1-2 FT AT 4-5 SECONDS DRIVEN MAINLY BY LOCAL WINDS. TSTMS IF ANY WILL REMAIN ISOLATED...AND MAINLY ON LAND IN THE LATE AFTERNOONS AND WELL OFFSHORE AT NIGHT. PRESSURE PATTERN SAT-MON WILL FOSTER SW WINDS 10-15 KT...HIGHER GUSTS BETWEEN 3PM-7PM IN-SHORE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR SCZ017-023-024-032-033-039-053>056. NC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR NCZ087-096-099-105>110. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ254- 256. SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ250- 252. && $$ SYNOPSIS... NEAR TERM...JDW SHORT TERM...31 LONG TERM...MJC AVIATION...JDW/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
219 PM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY...NE WINDS ON BACKSIDE OF SLOWLY DEPARTING INVERTED TROUGH HAVE BEEN THE ONLY STORY IN AN OTHERWISE BEAUTIFUL EARLY SUMMER DAY. LARGE EXPANSE OF CIRRUS/CIRROSTRATUS ASSOCIATED WITH TROPICAL DEPRESSION DEBBY CONTINUES TO PULL SLOWLY AWAY TO THE SOUTHEAST...LEAVING NEARLY CLOUDLESS SKY CONDITIONS ACROSS THE AREA. CLEAR SKY CONDITIONS WILL PERSIST THROUGH THE NIGHT...AND AS WINDS SLOWLY EASE DUE TO WEAKENING OF PRESSURE GRADIENT...NEARLY IDEAL RADIATIONAL COOLING WILL DEVELOP TONIGHT. WINDS WILL CONTINUE TO GUST UP TO 20 MPH NEAR THE COAST BEFORE EASING QUICKLY WITH LOSS OF HEATING AND THE DEVELOPMENT OF THE NOCTURNAL INVERSION. EXPECT FULL DECOUPLING OF WINDS SHORTLY AFTER NIGHTFALL...AND TEMPS WILL FALL RAPIDLY IN THE DRY COLUMN AFTER DARK. DURING THE NIGHT...MID LEVEL HIGH PUSHES EAST HELPING RAISE 850MB TEMPS 4-6C OVERNIGHT. THIS WILL ACT AS THE LIMITING FACTOR TO COOLING SINCE SURFACE TEMPS...EVEN THOUGH BELOW A STEEP INVERSION...WILL BE FORCED TO RISE AS WELL. THE COOLEST TEMPS MAY BE FELT A FEW HOURS AFTER MIDNIGHT BEFORE LEVELING OFF...OR EVEN RISING SLIGHTLY TOWARDS MORNING. STILL...HAVE LEANED MORE TOWARDS THE COOLER MAV GUIDANCE WITH TEMPS A DEGREE OR TWO ABOVE 60...EXCEPT UPPER 50S IN THE COOLEST POCOSIN SWAMPS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...HIGH PRESSURE AT THE SURFACE WILL WEAKEN OVER THE SOUTHEAST AS DEBBY SCOOTS OFF TO THE NORTHEAST INTO THE ATLANTIC THROUGH THE PERIOD. MEANWHILE IN THE MID TO UPPER LEVELS...STRONG RIDGE RUNNING UP THE MID WEST WILL SPREAD ACROSS MUCH OF THE SOUTHERN CONUS BUILDING EAST INTO THE CAROLINAS. THIS WILL BRING INCREASING H5 HEIGHTS REACHING UP AROUND 595 DEM OVER THE CAROLINAS BY LATE FRI WITH 850 TEMPS REACHING UP CLOSE TO 24C...PRODUCING THE HOTTEST WEATHER SO FAR THIS SUMMER...WITH POSSIBLE RECORD HEAT. SEE CLIMATE SECTION BELOW FOR RECORD VALUES. AFTER A COOL START THURS MORNING WITH TEMPS IN CLOSER TO 60...A HUGE DIURNAL SWING WILL OCCUR WITH TEMPS REACHING WELL INTO THE 90S BY AFTN. A RETURN FLOW WILL ALSO SET UP AT THE SURFACE WITH MOISTURE RETURNING. DEWPOINT TEMPS WILL RISE A GOOD 15 DEGREES FROM EARLY THURS TO LATE FRI. BY FRI AFTN...MOST AREAS WILL MOST LIKELY REACH HEAT ADVISORY CRITERIA WITH MAX TEMPS REACHING ABOVE 100...ESPECIALLY INLAND. WITH SUCH A STRONG RIDGE BUILDING OVERHEAD AND PLENTY OF DRY AIR AND SUBSIDENCE ALOFT...NOT EXPECTING ANY PCP THROUGH THE PERIOD. WILL BE HARD PRESSED TO SEE MUCH IN THE WAY OF ANY CLOUDS BUT WITH PIEDMONT TROUGH EVIDENT INLAND EACH DAY AND SEA BREEZE CLOSER TO THE COAST...MAY HAVE JUST ENOUGH CONVERGENCE IN THE VERY LOW LEVELS TO SEE A FEW CU AROUND. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY...SOUTHERLY RETURN FLOW WILL PREVAIL AT THE SURFACE AS BERMUDA HIGH DOMINATES WHILE THE PIEDMONT TROUGH IS EVIDENT EACH AFTERNOON OVER INLAND CAROLINAS. RIDGE ALOFT CONTINUES TO BUILD OVER THE SOUTHEAST WITH H5 HEIGHTS REACHING UP AROUND 25 C AND 850 TEMPS CONTINUING TO RISE THROUGH THE WEEKEND...LEADING TO RECORD HEAT POSSIBLE. SEE CLIMATE SECTION BELOW. LATEST GUIDANCE SHOWS WARMEST DAYS OVER THE WEEKEND WITH TEMPS REACHING ABOVE 100. WINDS IN THE LOWER LEVELS WILL ALSO HAVE AN INCREASING WESTERLY DOWNSLOPE COMPONENT WHICH WILL ALSO AID IN ENHANCING THE HEAT. WITH A MOIST SOUTHERLY RETURN FLOW SETTING UP...DEWPOINT TEMPS WILL ALSO RISE INTO THE MID 70S AND CLOSE TO 80 RIGHT ALONG THE COAST. THIS WILL PRODUCE APPARENT TEMPERATURES ABOVE 105 DEGREES IN MOST PLACES AND CLOSER TO 110 FURTHER INLAND. SOME PLACES MAY SEE APPARENT TEMPS UP CLOSE TO 115 DEGREES AS SEA BREEZE CARRIES IN HIGHER DEWPOINT AIR. SHOULD EXCEED HEAT ADVISORY CRITERIA EACH AFTERNOON THROUGH THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK. WITH SUCH STRONG RIDGE IN PLACE ALOFT...EXPECT CONVECTION TO REMAIN AT BAY. ALTHOUGH MODELS DO SHOW SOME POTENTIAL EACH AFTERNOON FROM SUNDAY ONWARDS AS UPPER RIDGE GETS SUPPRESSED A LITTLE FARTHER SOUTH AND SOUTHERLY RETURN FLOW PICKS UP IN TIGHTENED GRADIENT FLOW. IF ANY CLOUDS OR SHWRS DO DEVELOP IT WILL TAKE PLACE ALONG PIEDMONT TROUGH INLAND AND POSSIBLY ALONG CONVERGENT SEA BREEZE BOUNDARY CLOSER TO THE COAST. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...EXPECT VFR THROUGH VALID PERIOD AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. WITH NEARLY CLEAR SKIES...NORTHEAST WINDS WILL CONTINUE TO GUST TO AROUND 20 KTS...ESPECIALLY NEAR THE COAST...DUE TO A PINCHED GRADIENT NEAR A SURFACE TROUGH JUST OFFSHORE. TOWARDS SUNSET...GUSTS WILL SUBSIDE AND SUSTAINED WINDS WILL DECREASE...WITH LIGHT AND VARIABLE WINDS THROUGH MORNING. AFTER DAYBREAK ON THURSDAY...WINDS WILL BECOME SOUTHWEST WITH SUSTAINED WINDS AOB 10 KTS. EXTENDED OUTLOOK...EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY...INVERTED TROUGH EXTENDING NORTH FROM TROPICAL DEPRESSION DEBBY...NOW LOCATED OFF THE FLORIDA ATLANTIC COAST...IS CONTINUING TO BE STRONGER THAN GUIDANCE HAS BEEN ADVERTISING. LATEST MSAS ANALYSIS SHOWS THE TROUGH WEAKENING VERY SLOWLY...AND HRRR BEST REPRESENTS LATEST TRENDS. STILL EXPECT THIS TROUGH TO BREAK DOWN AS DEBBY PULLS OFF TO THE EAST...ALLOWING WINDS TO EASE AND SEAS TO THEN FALL. WITH THE TROUGH REMAINING STRONGER THAN CURRENT PROGS WINDS AND SEAS ARE RUNNING HIGHER THAN EARLIER FORECASTS ATTM...SO HAVE ENHANCED BOTH...AND EXTENDED THE SMALL CRAFT ADVISORY FOR AMZ256 AND AMZ254 UNTIL 8PM. AS WINDS DECAY TONIGHT...SEAS WILL FALL SLOWLY...BECOMING 2-4 FT OVERNIGHT WITH N/NE WINDS LESS THAN 10 KTS. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...DEBBY WILL MOVE OFF TO THE NORTHEAST INTO THE DISTANT ATLANTIC WHILE WEAK HIGH PRESSURE REMAINS OVER LOCAL WATERS. WILL SEE WINDS COMING AROUND ON THURS AS BERMUDA HIGH TAKES HOLD BY THE WEEKEND. THEREFORE LIGHT NORTHERLY WINDS EARLY THURS WILL BACK AROUND BECOMING MORE SOUTHERLY THROUGH FRI AND INCREASING UP TO 15 KTS. ANY RESIDUAL SWELL FROM DEBBY WILL SUBSIDE LEAVING SEAS AROUND 2 TO 3 FT OVER MOST WATERS BY LATE THURS INTO FRI. WITH SOME UNCERTAINTY AS TO THE STRENGTH AND TRACK OF DEBBY...WINDS AND SEAS MAY CHANGE. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 AM WEDNESDAY...MAY SEE SOME LONGER PERIOD SWELLS FROM DEBBY REACHING OUR LOCAL WATERS. THIS WILL DEPEND ON EXACT TRACK AND INTENSITY OF DEBBY AS THE SYSTEM MOVES NE FARTHER AWAY INTO THE ATLANTIC. OVERALL WILL SEE BERMUDA HIGH DOMINATE WITH INCREASING SOUTHERLY RETURN FLOW SETTING UP CLOSE TO 15 KTS. WINDS WILL INITIALLY BE MORE W-SW BUT WILL BACK TO THE SW THROUGH SUNDAY. SEAS 2 TO 3 FT MAY INCREASE UP TO 2 TO 4 FT BY SUN EVENING AS RETURN FLOW INCREASES AND BACKS BECOMING MORE SOUTHERLY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR SCZ017-023-024-032-033-039-053>056. NC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR NCZ087-096-099-105>110. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ254- 256. SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ250- 252. && $$ SYNOPSIS... NEAR TERM...JDW SHORT TERM...RGZ LONG TERM...RGZ AVIATION...JDW/SGL MARINE...JDW/RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 PM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM WEDNESDAY...VISIBLE IMAGERY THIS MORNING SHOWS THE CIRRUS SHIELD ASSOCIATED WITH TROPICAL DEPRESSION DEBBY POSITIONED WELL OFF THE ATLANTIC SEABOARD. THERE IS ABSOLUTELY NO CLOUD COVER OVER THE LAND MASS HOWEVER...AND AS HIGH PRESSURE BUILDS ALOFT AND AT THE SURFACE...VERY DRY AIR WILL CONTINUE TO WORK INTO THE AREA SO NEARLY CLOUDLESS SKY CONDITIONS ANTICIPATED TODAY. FORECAST PWATS HOVER AROUND 0.75 INCHES...WELL BELOW NORMAL FOR LATE JUNE...AND COMBINE THIS WITH TEMPS REACHING ONLY INTO THE LOW/MID 80S DUE TO COOL NE FLOW...TODAY WILL FEEL MORE LIKE LATE SPRING THAN EARLY SUMMER. THE ONLY CONCERN TODAY REVOLVES AROUND GUSTY MORNING WINDS NEAR THE COAST ON UPWIND SIDE OF AN INVERTED TROUGH EXTENDING ALONG THE COAST FROM TD DEBBY. THIS TROUGH WILL WEAKEN AND PULL OFF TO THE EAST TODAY...SO WINDS GUSTING UP TO 20 MPH NEAR THE COAST WILL WANE THROUGH THE AFTN...BECOMING EAST LESS THAN 10 MPH THROUGH THE DAY. AS HIGH PRESSURE DRIFTS JUST WEST OVERNIGHT...WINDS WILL DECOUPLE AND GOOD RADIATIONAL COOLING WILL OCCUR AGAIN. FORECAST SOUNDINGS SUGGEST LIGHT SW WINDS DEVELOPING LATE OVERNIGHT...AND A SLIGHT WARM-SHIFT IS NOTED DUE TO SOME WEAK WAA WHICH WILL KEEP MINS FROM BOTTOMING OUT. EXPECT THIS IS OVERDONE DUE TO THE WEAKNESS IN THE PRESSURE FIELD...SO FOR PERSISTENCE WILL SHOW GOOD RADIATIONAL COOLING WITH WIDESPREAD MINS RIGHT AROUND 60...WITH UPPER 50S IN THE COOLEST POCOSIN SWAMPS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...HIGH PRESSURE AT THE SURFACE WILL WEAKEN OVER THE SOUTHEAST AS DEBBY SCOOTS OFF TO THE NORTHEAST INTO THE ATLANTIC THROUGH THE PERIOD. MEANWHILE IN THE MID TO UPPER LEVELS...STRONG RIDGE RUNNING UP THE MID WEST WILL SPREAD ACROSS MUCH OF THE SOUTHERN CONUS BUILDING EAST INTO THE CAROLINAS. THIS WILL BRING INCREASING H5 HEIGHTS REACHING UP AROUND 595 DEM OVER THE CAROLINAS BY LATE FRI WITH 850 TEMPS REACHING UP CLOSE TO 24C...PRODUCING THE HOTTEST WEATHER SO FAR THIS SUMMER...WITH POSSIBLE RECORD HEAT. SEE CLIMATE SECTION BELOW FOR RECORD VALUES. AFTER A COOL START THURS MORNING WITH TEMPS IN CLOSER TO 60...A HUGE DIURNAL SWING WILL OCCUR WITH TEMPS REACHING WELL INTO THE 90S BY AFTN. A RETURN FLOW WILL ALSO SET UP AT THE SURFACE WITH MOISTURE RETURNING. DEWPOINT TEMPS WILL RISE A GOOD 15 DEGREES FROM EARLY THURS TO LATE FRI. BY FRI AFTN...MOST AREAS WILL MOST LIKELY REACH HEAT ADVISORY CRITERIA WITH MAX TEMPS REACHING ABOVE 100...ESPECIALLY INLAND. WITH SUCH A STRONG RIDGE BUILDING OVERHEAD AND PLENTY OF DRY AIR AND SUBSIDENCE ALOFT...NOT EXPECTING ANY PCP THROUGH THE PERIOD. WILL BE HARD PRESSED TO SEE MUCH IN THE WAY OF ANY CLOUDS BUT WITH PIEDMONT TROUGH EVIDENT INLAND EACH DAY AND SEA BREEZE CLOSER TO THE COAST...MAY HAVE JUST ENOUGH CONVERGENCE IN THE VERY LOW LEVELS TO SEE A FEW CU AROUND. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY...SOUTHERLY RETURN FLOW WILL PREVAIL AT THE SURFACE AS BERMUDA HIGH DOMINATES WHILE THE PIEDMONT TROUGH IS EVIDENT EACH AFTERNOON OVER INLAND CAROLINAS. RIDGE ALOFT CONTINUES TO BUILD OVER THE SOUTHEAST WITH H5 HEIGHTS REACHING UP AROUND 25 C AND 850 TEMPS CONTINUING TO RISE THROUGH THE WEEKEND...LEADING TO RECORD HEAT POSSIBLE. SEE CLIMATE SECTION BELOW. LATEST GUIDANCE SHOWS WARMEST DAYS OVER THE WEEKEND WITH TEMPS REACHING ABOVE 100. WINDS IN THE LOWER LEVELS WILL ALSO HAVE AN INCREASING WESTERLY DOWNSLOPE COMPONENT WHICH WILL ALSO AID IN ENHANCING THE HEAT. WITH A MOIST SOUTHERLY RETURN FLOW SETTING UP...DEWPOINT TEMPS WILL ALSO RISE INTO THE MID 70S AND CLOSE TO 80 RIGHT ALONG THE COAST. THIS WILL PRODUCE APPARENT TEMPERATURES ABOVE 105 DEGREES IN MOST PLACES AND CLOSER TO 110 FURTHER INLAND. SOME PLACES MAY SEE APPARENT TEMPS UP CLOSE TO 115 DEGREES AS SEA BREEZE CARRIES IN HIGHER DEWPOINT AIR. SHOULD EXCEED HEAT ADVISORY CRITERIA EACH AFTERNOON THROUGH THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK. WITH SUCH STRONG RIDGE IN PLACE ALOFT...EXPECT CONVECTION TO REMAIN AT BAY. ALTHOUGH MODELS DO SHOW SOME POTENTIAL EACH AFTERNOON FROM SUNDAY ONWARDS AS UPPER RIDGE GETS SUPPRESSED A LITTLE FARTHER SOUTH AND SOUTHERLY RETURN FLOW PICKS UP IN TIGHTENED GRADIENT FLOW. IF ANY CLOUDS OR SHWRS DO DEVELOP IT WILL TAKE PLACE ALONG PIEDMONT TROUGH INLAND AND POSSIBLY ALONG CONVERGENT SEA BREEZE BOUNDARY CLOSER TO THE COAST. && .AVIATION /12Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...EXPECT VFR THROUGH VALID PERIOD AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. WITH NEARLY CLEAR SKIES...NORTHEAST WINDS WILL CONTINUE TO GUST TO AROUND 20 KTS...ESPECIALLY NEAR THE COAST...DUE TO A PINCHED GRADIENT NEAR A SURFACE TROUGH JUST OFFSHORE. TOWARDS SUNSET...GUSTS WILL SUBSIDE AND SUSTAINED WINDS WILL DECREASE...WITH LIGHT AND VARIABLE WINDS THROUGH MORNING. AFTER DAYBREAK ON THURSDAY...WINDS WILL BECOME SOUTHWEST WITH SUSTAINED WINDS AOB 10 KTS. EXTENDED OUTLOOK...EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM THURSDAY...CURRENT WIND AND SEAS MATCH ONGOING FORECAST...SO NO UPDATES NEEDED AT THIS TIME. STILL EXPECT SLOWLY EASING WINDS AND SEAS AS INVERTED TROUGH WEAKENS TODAY. PREVIOUS DISCUSSION FROM 300 AM BELOW: TROPICAL DEPRESSION DEBBY IS INLAND ACROSS NORTH-CENTRAL FLORIDA THIS MORNING. OF MORE IMPORTANCE TO OUR WEATHER IS AN INVERTED SURFACE TROUGH THAT EXTENDS WELL NORTHEAST OF DEBBY ALONG THE GULF STREAM AS FAR NORTH AS SOUTH CAROLINA. A TIGHT PRESSURE GRADIENT BETWEEN THIS TROUGH AND HIGH PRESSURE IN THE OHIO VALLEY IS PRODUCING STRONG NORTHEAST WINDS THIS MORNING. AMONG OUR SUITE OF MODEL GUIDANCE THE GFS AND RUC APPEAR TO BE HANDLING CONDITIONS BEST AND THESE TWO MODELS WERE USED TO CONSTRUCT THE FORECAST TODAY. THE STRONGEST WINDS ARE EXPECTED TO OCCUR BETWEEN NOW AND 9 AM WITH 25-30 KNOT WINDS AND 6+ FOOT SEAS EXPECTED AWAY FROM SHORE. WIND GUSTS OVER 25 KNOTS ARE POSSIBLE EVEN NEARSHORE AT TIMES. WINDS SHOULD BEGIN TO ABATE LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON... AND I HAVE TENTATIVELY FORECAST SMALL CRAFT ADVISORY CONDITIONS TO END BY 5 PM. WINDS WILL BACK TO THE NORTH TONIGHT...THEN TO THE NORTHWEST LATE AS A LAND BREEZE SPREADS OFFSHORE. SEAS AT THE FRYING PAN SHOALS BUOY HAVE BUILT TO 8 FEET EARLY THIS MORNING...AND MAY BUILD TO 9 FEET OVER THE NEXT SEVERAL HOURS. WITHIN 20 MILES OF SHORE 6-7 FOOT SEAS ARE POSSIBLE...AND SOME 8-9 FOOT SEAS COULD EVEN DEVELOP EAST OF WINYAH BAY WHERE A PARTICULARLY LONG NORTHEAST FETCH WILL MAINTAIN ITSELF FOR 12-18 HOURS. ONCE WIND SPEEDS DIMINISH LATE THIS MORNING INTO THE AFTERNOON SEA HEIGHTS SHOULD SUBSIDE RATHER QUICKLY...WITH 2-4 FT SEAS EXPECTED AFTER MIDNIGHT TONIGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...DEBBY WILL MOVE OFF TO THE NORTHEAST INTO THE DISTANT ATLANTIC WHILE WEAK HIGH PRESSURE REMAINS OVER LOCAL WATERS. WILL SEE WINDS COMING AROUND ON THURS AS BERMUDA HIGH TAKES HOLD BY THE WEEKEND. THEREFORE LIGHT NORTHERLY WINDS EARLY THURS WILL BACK AROUND BECOMING MORE SOUTHERLY THROUGH FRI AND INCREASING UP TO 15 KTS. ANY RESIDUAL SWELL FROM DEBBY WILL SUBSIDE LEAVING SEAS AROUND 2 TO 3 FT OVER MOST WATERS BY LATE THURS INTO FRI. WITH SOME UNCERTAINTY AS TO THE STRENGTH AND TRACK OF DEBBY...WINDS AND SEAS MAY CHANGE. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 AM WEDNESDAY...MAY SEE SOME LONGER PERIOD SWELLS FROM DEBBY REACHING OUR LOCAL WATERS. THIS WILL DEPEND ON EXACT TRACK AND INTENSITY OF DEBBY AS THE SYSTEM MOVES NE FARTHER AWAY INTO THE ATLANTIC. OVERALL WILL SEE BERMUDA HIGH DOMINATE WITH INCREASING SOUTHERLY RETURN FLOW SETTING UP CLOSE TO 15 KTS. WINDS WILL INITIALLY BE MORE W-SW BUT WILL BACK TO THE SW THROUGH SUNDAY. SEAS 2 TO 3 FT MAY INCREASE UP TO 2 TO 4 FT BY SUN EVENING AS RETURN FLOW INCREASES AND BACKS BECOMING MORE SOUTHERLY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ250-252-254-256. && $$ NEAR TERM...JDW SHORT TERM...RGZ LONG TERM...RGZ AVIATION...SGL/JDW
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
1004 AM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM WEDNESDAY...VISIBLE IMAGERY THIS MORNING SHOWS THE CIRRUS SHIELD ASSOCIATED WITH TROPICAL DEPRESSION DEBBY POSITIONED WELL OFF THE ATLANTIC SEABOARD. THERE IS ABSOLUTELY NO CLOUD COVER OVER THE LAND MASS HOWEVER...AND AS HIGH PRESSURE BUILDS ALOFT AND AT THE SURFACE...VERY DRY AIR WILL CONTINUE TO WORK INTO THE AREA SO NEARLY CLOUDLESS SKY CONDITIONS ANTICIPATED TODAY. FORECAST PWATS HOVER AROUND 0.75 INCHES...WELL BELOW NORMAL FOR LATE JUNE...AND COMBINE THIS WITH TEMPS REACHING ONLY INTO THE LOW/MID 80S DUE TO COOL NE FLOW...TODAY WILL FEEL MORE LIKE LATE SPRING THAN EARLY SUMMER. THE ONLY CONCERN TODAY REVOLVES AROUND GUSTY MORNING WINDS NEAR THE COAST ON UPWIND SIDE OF AN INVERTED TROUGH EXTENDING ALONG THE COAST FROM TD DEBBY. THIS TROUGH WILL WEAKEN AND PULL OFF TO THE EAST TODAY...SO WINDS GUSTING UP TO 20 MPH NEAR THE COAST WILL WANE THROUGH THE AFTN...BECOMING EAST LESS THAN 10 MPH THROUGH THE DAY. AS HIGH PRESSURE DRIFTS JUST WEST OVERNIGHT...WINDS WILL DECOUPLE AND GOOD RADIATIONAL COOLING WILL OCCUR AGAIN. FORECAST SOUNDINGS SUGGEST LIGHT SW WINDS DEVELOPING LATE OVERNIGHT...AND A SLIGHT WARM-SHIFT IS NOTED DUE TO SOME WEAK WAA WHICH WILL KEEP MINS FROM BOTTOMING OUT. EXPECT THIS IS OVERDONE DUE TO THE WEAKNESS IN THE PRESSURE FIELD...SO FOR PERSISTENCE WILL SHOW GOOD RADIATIONAL COOLING WITH WIDESPREAD MINS RIGHT AROUND 60...WITH UPPER 50S IN THE COOLEST POCOSIN SWAMPS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...HIGH PRESSURE AT THE SURFACE WILL WEAKEN OVER THE SOUTHEAST AS DEBBY SCOOTS OFF TO THE NORTHEAST INTO THE ATLANTIC THROUGH THE PERIOD. MEANWHILE IN THE MID TO UPPER LEVELS...STRONG RIDGE RUNNING UP THE MID WEST WILL SPREAD ACROSS MUCH OF THE SOUTHERN CONUS BUILDING EAST INTO THE CAROLINAS. THIS WILL BRING INCREASING H5 HEIGHTS REACHING UP AROUND 595 DEM OVER THE CAROLINAS BY LATE FRI WITH 850 TEMPS REACHING UP CLOSE TO 24C...PRODUCING THE HOTTEST WEATHER SO FAR THIS SUMMER...WITH POSSIBLE RECORD HEAT. SEE CLIMATE SECTION BELOW FOR RECORD VALUES. AFTER A COOL START THURS MORNING WITH TEMPS IN CLOSER TO 60...A HUGE DIURNAL SWING WILL OCCUR WITH TEMPS REACHING WELL INTO THE 90S BY AFTN. A RETURN FLOW WILL ALSO SET UP AT THE SURFACE WITH MOISTURE RETURNING. DEWPOINT TEMPS WILL RISE A GOOD 15 DEGREES FROM EARLY THURS TO LATE FRI. BY FRI AFTN...MOST AREAS WILL MOST LIKELY REACH HEAT ADVISORY CRITERIA WITH MAX TEMPS REACHING ABOVE 100...ESPECIALLY INLAND. WITH SUCH A STRONG RIDGE BUILDING OVERHEAD AND PLENTY OF DRY AIR AND SUBSIDENCE ALOFT...NOT EXPECTING ANY PCP THROUGH THE PERIOD. WILL BE HARD PRESSED TO SEE MUCH IN THE WAY OF ANY CLOUDS BUT WITH PIEDMONT TROUGH EVIDENT INLAND EACH DAY AND SEA BREEZE CLOSER TO THE COAST...MAY HAVE JUST ENOUGH CONVERGENCE IN THE VERY LOW LEVELS TO SEE A FEW CU AROUND. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY...SOUTHERLY RETURN FLOW WILL PREVAIL AT THE SURFACE AS BERMUDA HIGH DOMINATES WHILE THE PIEDMONT TROUGH IS EVIDENT EACH AFTERNOON OVER INLAND CAROLINAS. RIDGE ALOFT CONTINUES TO BUILD OVER THE SOUTHEAST WITH H5 HEIGHTS REACHING UP AROUND 25 C AND 850 TEMPS CONTINUING TO RISE THROUGH THE WEEKEND...LEADING TO RECORD HEAT POSSIBLE. SEE CLIMATE SECTION BELOW. LATEST GUIDANCE SHOWS WARMEST DAYS OVER THE WEEKEND WITH TEMPS REACHING ABOVE 100. WINDS IN THE LOWER LEVELS WILL ALSO HAVE AN INCREASING WESTERLY DOWNSLOPE COMPONENT WHICH WILL ALSO AID IN ENHANCING THE HEAT. WITH A MOIST SOUTHERLY RETURN FLOW SETTING UP...DEWPOINT TEMPS WILL ALSO RISE INTO THE MID 70S AND CLOSE TO 80 RIGHT ALONG THE COAST. THIS WILL PRODUCE APPARENT TEMPERATURES ABOVE 105 DEGREES IN MOST PLACES AND CLOSER TO 110 FURTHER INLAND. SOME PLACES MAY SEE APPARENT TEMPS UP CLOSE TO 115 DEGREES AS SEA BREEZE CARRIES IN HIGHER DEWPOINT AIR. SHOULD EXCEED HEAT ADVISORY CRITERIA EACH AFTERNOON THROUGH THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK. WITH SUCH STRONG RIDGE IN PLACE ALOFT...EXPECT CONVECTION TO REMAIN AT BAY. ALTHOUGH MODELS DO SHOW SOME POTENTIAL EACH AFTERNOON FROM SUNDAY ONWARDS AS UPPER RIDGE GETS SUPPRESSED A LITTLE FARTHER SOUTH AND SOUTHERLY RETURN FLOW PICKS UP IN TIGHTENED GRADIENT FLOW. IF ANY CLOUDS OR SHWRS DO DEVELOP IT WILL TAKE PLACE ALONG PIEDMONT TROUGH INLAND AND POSSIBLY ALONG CONVERGENT SEA BREEZE BOUNDARY CLOSER TO THE COAST. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...EXPECT VFR THROUGH VALID PERIOD AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. WITH NEARLY CLEAR SKIES...NORTHEAST WINDS WILL INCREASE THROUGHOUT THE DAY TO AOB 12 KTS WITH GUSTS NEAR 22 KTS. BY EARLY EVENING...GUSTS WILL SUBSIDE AND SUSTAINED WINDS WILL DECREASE...WITH LIGHT AND VARIABLE WINDS THROUGH THE REMAINDER OF THE PERIOD. EXTENDED OUTLOOK...EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM THURSDAY...CURRENT WIND AND SEAS MATCH ONGOING FORECAST...SO NO UPDATES NEEDED AT THIS TIME. STILL EXPECT SLOWLY EASING WINDS AND SEAS AS INVERTED TROUGH WEAKENS TODAY. PREVIOUS DISCUSSION FROM 300 AM BELOW: TROPICAL DEPRESSION DEBBY IS INLAND ACROSS NORTH-CENTRAL FLORIDA THIS MORNING. OF MORE IMPORTANCE TO OUR WEATHER IS AN INVERTED SURFACE TROUGH THAT EXTENDS WELL NORTHEAST OF DEBBY ALONG THE GULF STREAM AS FAR NORTH AS SOUTH CAROLINA. A TIGHT PRESSURE GRADIENT BETWEEN THIS TROUGH AND HIGH PRESSURE IN THE OHIO VALLEY IS PRODUCING STRONG NORTHEAST WINDS THIS MORNING. AMONG OUR SUITE OF MODEL GUIDANCE THE GFS AND RUC APPEAR TO BE HANDLING CONDITIONS BEST AND THESE TWO MODELS WERE USED TO CONSTRUCT THE FORECAST TODAY. THE STRONGEST WINDS ARE EXPECTED TO OCCUR BETWEEN NOW AND 9 AM WITH 25-30 KNOT WINDS AND 6+ FOOT SEAS EXPECTED AWAY FROM SHORE. WIND GUSTS OVER 25 KNOTS ARE POSSIBLE EVEN NEARSHORE AT TIMES. WINDS SHOULD BEGIN TO ABATE LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON... AND I HAVE TENTATIVELY FORECAST SMALL CRAFT ADVISORY CONDITIONS TO END BY 5 PM. WINDS WILL BACK TO THE NORTH TONIGHT...THEN TO THE NORTHWEST LATE AS A LAND BREEZE SPREADS OFFSHORE. SEAS AT THE FRYING PAN SHOALS BUOY HAVE BUILT TO 8 FEET EARLY THIS MORNING...AND MAY BUILD TO 9 FEET OVER THE NEXT SEVERAL HOURS. WITHIN 20 MILES OF SHORE 6-7 FOOT SEAS ARE POSSIBLE...AND SOME 8-9 FOOT SEAS COULD EVEN DEVELOP EAST OF WINYAH BAY WHERE A PARTICULARLY LONG NORTHEAST FETCH WILL MAINTAIN ITSELF FOR 12-18 HOURS. ONCE WIND SPEEDS DIMINISH LATE THIS MORNING INTO THE AFTERNOON SEA HEIGHTS SHOULD SUBSIDE RATHER QUICKLY...WITH 2-4 FT SEAS EXPECTED AFTER MIDNIGHT TONIGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...DEBBY WILL MOVE OFF TO THE NORTHEAST INTO THE DISTANT ATLANTIC WHILE WEAK HIGH PRESSURE REMAINS OVER LOCAL WATERS. WILL SEE WINDS COMING AROUND ON THURS AS BERMUDA HIGH TAKES HOLD BY THE WEEKEND. THEREFORE LIGHT NORTHERLY WINDS EARLY THURS WILL BACK AROUND BECOMING MORE SOUTHERLY THROUGH FRI AND INCREASING UP TO 15 KTS. ANY RESIDUAL SWELL FROM DEBBY WILL SUBSIDE LEAVING SEAS AROUND 2 TO 3 FT OVER MOST WATERS BY LATE THURS INTO FRI. WITH SOME UNCERTAINTY AS TO THE STRENGTH AND TRACK OF DEBBY...WINDS AND SEAS MAY CHANGE. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 AM WEDNESDAY...MAY SEE SOME LONGER PERIOD SWELLS FROM DEBBY REACHING OUR LOCAL WATERS. THIS WILL DEPEND ON EXACT TRACK AND INTENSITY OF DEBBY AS THE SYSTEM MOVES NE FARTHER AWAY INTO THE ATLANTIC. OVERALL WILL SEE BERMUDA HIGH DOMINATE WITH INCREASING SOUTHERLY RETURN FLOW SETTING UP CLOSE TO 15 KTS. WINDS WILL INITIALLY BE MORE W-SW BUT WILL BACK TO THE SW THROUGH SUNDAY. SEAS 2 TO 3 FT MAY INCREASE UP TO 2 TO 4 FT BY SUN EVENING AS RETURN FLOW INCREASES AND BACKS BECOMING MORE SOUTHERLY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ250-252-254-256. && $$ NEAR TERM...JDW SHORT TERM...RGZ LONG TERM...RGZ AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
725 AM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM WEDNESDAY...IT APPEARS WE`VE BROKEN SEVERAL RECORD LOWS THIS MORNING. WILMINGTON HAS BEEN DOWN TO 57 DEGREES...BREAKING THE PREVIOUS RECORD OF 61 SET BACK IN 1955. AT NORTH MYRTLE BEACH THE TEMPERATURE DIPPED TO 58 BREAKING THE OLD RECORD OF 63 DATING BACK TO 1955. AND FLORENCE HAS ALSO SET A NEW RECORD LOW OF 58 BREAKING THE OLD RECORD OF 60 SET BACK IN 1979. OTHERWISE THE FORECAST APPEARS TO BE IN GOOD SHAPE WITH NO SIGNIFICANT CHANGES NEEDED TO THE FORECAST. THE PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... THE CIRRUS SHIELD ASSOCIATED WITH TROPICAL DEPRESSION DEBBY AND THE INVERTED SURFACE TROUGH HAS PUSHED OFFSHORE THIS MORNING. IN ITS WAKE MUCH DRIER AIR HAS BUILT INTO THE EASTERN CAROLINAS WITH PRECIPITABLE WATER VALUES NOW AROUND 0.6 INCHES VERSUS 2.4 INCHES IN THE TROPICAL PLUME TO OUR SOUTH. DEBBY`S FORECAST PATH KEEPS THE SYSTEM AND ITS CLOUDINESS TOO FAR SOUTH AND EAST FOR ANY DIRECT IMPACTS ON OUR AREA. NORTHEAST BREEZES TODAY WILL BECOME LIGHT AND VARIABLE TONIGHT AS HIGH PRESSURE OVER THE OHIO VALLEY MOVES INTO THE CAROLINAS. HIGHS TODAY SHOULD REACH 85-87 INLAND...WITH 81-84 EXPECTED NEAR THE COAST. LOWS TONIGHT SHOULD FALL TO 59-65 WITH THE WARMEST READINGS ON THE BEACHES. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...HIGH PRESSURE AT THE SURFACE WILL WEAKEN OVER THE SOUTHEAST AS DEBBY SCOOTS OFF TO THE NORTHEAST INTO THE ATLANTIC THROUGH THE PERIOD. MEANWHILE IN THE MID TO UPPER LEVELS...STRONG RIDGE RUNNING UP THE MID WEST WILL SPREAD ACROSS MUCH OF THE SOUTHERN CONUS BUILDING EAST INTO THE CAROLINAS. THIS WILL BRING INCREASING H5 HEIGHTS REACHING UP AROUND 595 DEM OVER THE CAROLINAS BY LATE FRI WITH 850 TEMPS REACHING UP CLOSE TO 24C...PRODUCING THE HOTTEST WEATHER SO FAR THIS SUMMER...WITH POSSIBLE RECORD HEAT. SEE CLIMATE SECTION BELOW FOR RECORD VALUES. AFTER A COOL START THURS MORNING WITH TEMPS IN CLOSER TO 60...A HUGE DIURNAL SWING WILL OCCUR WITH TEMPS REACHING WELL INTO THE 90S BY AFTN. A RETURN FLOW WILL ALSO SET UP AT THE SURFACE WITH MOISTURE RETURNING. DEWPOINT TEMPS WILL RISE A GOOD 15 DEGREES FROM EARLY THURS TO LATE FRI. BY FRI AFTN...MOST AREAS WILL MOST LIKELY REACH HEAT ADVISORY CRITERIA WITH MAX TEMPS REACHING ABOVE 100...ESPECIALLY INLAND. WITH SUCH A STRONG RIDGE BUILDING OVERHEAD AND PLENTY OF DRY AIR AND SUBSIDENCE ALOFT...NOT EXPECTING ANY PCP THROUGH THE PERIOD. WILL BE HARD PRESSED TO SEE MUCH IN THE WAY OF ANY CLOUDS BUT WITH PIEDMONT TROUGH EVIDENT INLAND EACH DAY AND SEA BREEZE CLOSER TO THE COAST...MAY HAVE JUST ENOUGH CONVERGENCE IN THE VERY LOW LEVELS TO SEE A FEW CU AROUND. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY...SOUTHERLY RETURN FLOW WILL PREVAIL AT THE SURFACE AS BERMUDA HIGH DOMINATES WHILE THE PIEDMONT TROUGH IS EVIDENT EACH AFTERNOON OVER INLAND CAROLINAS. RIDGE ALOFT CONTINUES TO BUILD OVER THE SOUTHEAST WITH H5 HEIGHTS REACHING UP AROUND 25 C AND 850 TEMPS CONTINUING TO RISE THROUGH THE WEEKEND...LEADING TO RECORD HEAT POSSIBLE. SEE CLIMATE SECTION BELOW. LATEST GUIDANCE SHOWS WARMEST DAYS OVER THE WEEKEND WITH TEMPS REACHING ABOVE 100. WINDS IN THE LOWER LEVELS WILL ALSO HAVE AN INCREASING WESTERLY DOWNSLOPE COMPONENT WHICH WILL ALSO AID IN ENHANCING THE HEAT. WITH A MOIST SOUTHERLY RETURN FLOW SETTING UP...DEWPOINT TEMPS WILL ALSO RISE INTO THE MID 70S AND CLOSE TO 80 RIGHT ALONG THE COAST. THIS WILL PRODUCE APPARENT TEMPERATURES ABOVE 105 DEGREES IN MOST PLACES AND CLOSER TO 110 FURTHER INLAND. SOME PLACES MAY SEE APPARENT TEMPS UP CLOSE TO 115 DEGREES AS SEA BREEZE CARRIES IN HIGHER DEWPOINT AIR. SHOULD EXCEED HEAT ADVISORY CRITERIA EACH AFTERNOON THROUGH THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK. WITH SUCH STRONG RIDGE IN PLACE ALOFT...EXPECT CONVECTION TO REMAIN AT BAY. ALTHOUGH MODELS DO SHOW SOME POTENTIAL EACH AFTERNOON FROM SUNDAY ONWARDS AS UPPER RIDGE GETS SUPPRESSED A LITTLE FARTHER SOUTH AND SOUTHERLY RETURN FLOW PICKS UP IN TIGHTENED GRADIENT FLOW. IF ANY CLOUDS OR SHWRS DO DEVELOP IT WILL TAKE PLACE ALONG PIEDMONT TROUGH INLAND AND POSSIBLY ALONG CONVERGENT SEA BREEZE BOUNDARY CLOSER TO THE COAST. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...EXPECT VFR THROUGH VALID PERIOD AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. WITH NEARLY CLEAR SKIES...NORTHEAST WINDS WILL INCREASE THROUGHOUT THE DAY TO AOB 12 KTS WITH GUSTS NEAR 22 KTS. BY EARLY EVENING...GUSTS WILL SUBSIDE AND SUSTAINED WINDS WILL DECREASE...WITH LIGHT AND VARIABLE WINDS THROUGH THE REMAINDER OF THE PERIOD. EXTENDED OUTLOOK...EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM WEDNESDAY...CURRENTLY WIND AND SEA OBSERVATIONS MATCH FORECASTS...NO UPDATES ARE NEEDED. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... TROPICAL DEPRESSION DEBBY IS INLAND ACROSS NORTH-CENTRAL FLORIDA THIS MORNING. OF MORE IMPORTANCE TO OUR WEATHER IS AN INVERTED SURFACE TROUGH THAT EXTENDS WELL NORTHEAST OF DEBBY ALONG THE GULF STREAM AS FAR NORTH AS SOUTH CAROLINA. A TIGHT PRESSURE GRADIENT BETWEEN THIS TROUGH AND HIGH PRESSURE IN THE OHIO VALLEY IS PRODUCING STRONG NORTHEAST WINDS THIS MORNING. AMONG OUR SUITE OF MODEL GUIDANCE THE GFS AND RUC APPEAR TO BE HANDLING CONDITIONS BEST AND THESE TWO MODELS WERE USED TO CONSTRUCT THE FORECAST TODAY. THE STRONGEST WINDS ARE EXPECTED TO OCCUR BETWEEN NOW AND 9 AM WITH 25-30 KNOT WINDS AND 6+ FOOT SEAS EXPECTED AWAY FROM SHORE. WIND GUSTS OVER 25 KNOTS ARE POSSIBLE EVEN NEARSHORE AT TIMES. WINDS SHOULD BEGIN TO ABATE LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON... AND I HAVE TENTATIVELY FORECAST SMALL CRAFT ADVISORY CONDITIONS TO END BY 5 PM. WINDS WILL BACK TO THE NORTH TONIGHT...THEN TO THE NORTHWEST LATE AS A LAND BREEZE SPREADS OFFSHORE. SEAS AT THE FRYING PAN SHOALS BUOY HAVE BUILT TO 8 FEET EARLY THIS MORNING...AND MAY BUILD TO 9 FEET OVER THE NEXT SEVERAL HOURS. WITHIN 20 MILES OF SHORE 6-7 FOOT SEAS ARE POSSIBLE...AND SOME 8-9 FOOT SEAS COULD EVEN DEVELOP EAST OF WINYAH BAY WHERE A PARTICULARLY LONG NORTHEAST FETCH WILL MAINTAIN ITSELF FOR 12-18 HOURS. ONCE WIND SPEEDS DIMINISH LATE THIS MORNING INTO THE AFTERNOON SEA HEIGHTS SHOULD SUBSIDE RATHER QUICKLY...WITH 2-4 FT SEAS EXPECTED AFTER MIDNIGHT TONIGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...DEBBY WILL MOVE OFF TO THE NORTHEAST INTO THE DISTANT ATLANTIC WHILE WEAK HIGH PRESSURE REMAINS OVER LOCAL WATERS. WILL SEE WINDS COMING AROUND ON THURS AS BERMUDA HIGH TAKES HOLD BY THE WEEKEND. THEREFORE LIGHT NORTHERLY WINDS EARLY THURS WILL BACK AROUND BECOMING MORE SOUTHERLY THROUGH FRI AND INCREASING UP TO 15 KTS. ANY RESIDUAL SWELL FROM DEBBY WILL SUBSIDE LEAVING SEAS AROUND 2 TO 3 FT OVER MOST WATERS BY LATE THURS INTO FRI. WITH SOME UNCERTAINTY AS TO THE STRENGTH AND TRACK OF DEBBY...WINDS AND SEAS MAY CHANGE. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 AM WEDNESDAY...MAY SEE SOME LONGER PERIOD SWELLS FROM DEBBY REACHING OUR LOCAL WATERS. THIS WILL DEPEND ON EXACT TRACK AND INTENSITY OF DEBBY AS THE SYSTEM MOVES NE FARTHER AWAY INTO THE ATLANTIC. OVERALL WILL SEE BERMUDA HIGH DOMINATE WITH INCREASING SOUTHERLY RETURN FLOW SETTING UP CLOSE TO 15 KTS. WINDS WILL INITIALLY BE MORE W-SW BUT WILL BACK TO THE SW THROUGH SUNDAY. SEAS 2 TO 3 FT MAY INCREASE UP TO 2 TO 4 FT BY SUN EVENING AS RETURN FLOW INCREASES AND BACKS BECOMING MORE SOUTHERLY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ250- 252-254-256. && $$ NEAR TERM...TRA SHORT TERM...RGZ LONG TERM...RGZ AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
637 AM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM WEDNESDAY...IT APPEARS WE`VE BROKEN SEVERAL RECORD LOWS THIS MORNING. WILMINGTON HAS BEEN DOWN TO 57 DEGREES...BREAKING THE PREVIOUS RECORD OF 61 SET BACK IN 1955. AT NORTH MYRTLE BEACH THE TEMPERATURE DIPPED TO 58 BREAKING THE OLD RECORD OF 63 DATING BACK TO 1955. AND FLORENCE HAS ALSO SET A NEW RECORD LOW OF 58 BREAKING THE OLD RECORD OF 60 SET BACK IN 1979. OTHERWISE THE FORECAST APPEARS TO BE IN GOOD SHAPE WITH NO SIGNIFICANT CHANGES NEEDED TO THE FORECAST. THE PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... THE CIRRUS SHIELD ASSOCIATED WITH TROPICAL DEPRESSION DEBBY AND THE INVERTED SURFACE TROUGH HAS PUSHED OFFSHORE THIS MORNING. IN ITS WAKE MUCH DRIER AIR HAS BUILT INTO THE EASTERN CAROLINAS WITH PRECIPITABLE WATER VALUES NOW AROUND 0.6 INCHES VERSUS 2.4 INCHES IN THE TROPICAL PLUME TO OUR SOUTH. DEBBY`S FORECAST PATH KEEPS THE SYSTEM AND ITS CLOUDINESS TOO FAR SOUTH AND EAST FOR ANY DIRECT IMPACTS ON OUR AREA. NORTHEAST BREEZES TODAY WILL BECOME LIGHT AND VARIABLE TONIGHT AS HIGH PRESSURE OVER THE OHIO VALLEY MOVES INTO THE CAROLINAS. HIGHS TODAY SHOULD REACH 85-87 INLAND...WITH 81-84 EXPECTED NEAR THE COAST. LOWS TONIGHT SHOULD FALL TO 59-65 WITH THE WARMEST READINGS ON THE BEACHES. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...HIGH PRESSURE AT THE SURFACE WILL WEAKEN OVER THE SOUTHEAST AS DEBBY SCOOTS OFF TO THE NORTHEAST INTO THE ATLANTIC THROUGH THE PERIOD. MEANWHILE IN THE MID TO UPPER LEVELS...STRONG RIDGE RUNNING UP THE MID WEST WILL SPREAD ACROSS MUCH OF THE SOUTHERN CONUS BUILDING EAST INTO THE CAROLINAS. THIS WILL BRING INCREASING H5 HEIGHTS REACHING UP AROUND 595 DEM OVER THE CAROLINAS BY LATE FRI WITH 850 TEMPS REACHING UP CLOSE TO 24C...PRODUCING THE HOTTEST WEATHER SO FAR THIS SUMMER...WITH POSSIBLE RECORD HEAT. SEE CLIMATE SECTION BELOW FOR RECORD VALUES. AFTER A COOL START THURS MORNING WITH TEMPS IN CLOSER TO 60...A HUGE DIURNAL SWING WILL OCCUR WITH TEMPS REACHING WELL INTO THE 90S BY AFTN. A RETURN FLOW WILL ALSO SET UP AT THE SURFACE WITH MOISTURE RETURNING. DEWPOINT TEMPS WILL RISE A GOOD 15 DEGREES FROM EARLY THURS TO LATE FRI. BY FRI AFTN...MOST AREAS WILL MOST LIKELY REACH HEAT ADVISORY CRITERIA WITH MAX TEMPS REACHING ABOVE 100...ESPECIALLY INLAND. WITH SUCH A STRONG RIDGE BUILDING OVERHEAD AND PLENTY OF DRY AIR AND SUBSIDENCE ALOFT...NOT EXPECTING ANY PCP THROUGH THE PERIOD. WILL BE HARD PRESSED TO SEE MUCH IN THE WAY OF ANY CLOUDS BUT WITH PIEDMONT TROUGH EVIDENT INLAND EACH DAY AND SEA BREEZE CLOSER TO THE COAST...MAY HAVE JUST ENOUGH CONVERGENCE IN THE VERY LOW LEVELS TO SEE A FEW CU AROUND. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY...SOUTHERLY RETURN FLOW WILL PREVAIL AT THE SURFACE AS BERMUDA HIGH DOMINATES WHILE THE PIEDMONT TROUGH IS EVIDENT EACH AFTERNOON OVER INLAND CAROLINAS. RIDGE ALOFT CONTINUES TO BUILD OVER THE SOUTHEAST WITH H5 HEIGHTS REACHING UP AROUND 25 C AND 850 TEMPS CONTINUING TO RISE THROUGH THE WEEKEND...LEADING TO RECORD HEAT POSSIBLE. SEE CLIMATE SECTION BELOW. LATEST GUIDANCE SHOWS WARMEST DAYS OVER THE WEEKEND WITH TEMPS REACHING ABOVE 100. WINDS IN THE LOWER LEVELS WILL ALSO HAVE AN INCREASING WESTERLY DOWNSLOPE COMPONENT WHICH WILL ALSO AID IN ENHANCING THE HEAT. WITH A MOIST SOUTHERLY RETURN FLOW SETTING UP...DEWPOINT TEMPS WILL ALSO RISE INTO THE MID 70S AND CLOSE TO 80 RIGHT ALONG THE COAST. THIS WILL PRODUCE APPARENT TEMPERATURES ABOVE 105 DEGREES IN MOST PLACES AND CLOSER TO 110 FURTHER INLAND. SOME PLACES MAY SEE APPARENT TEMPS UP CLOSE TO 115 DEGREES AS SEA BREEZE CARRIES IN HIGHER DEWPOINT AIR. SHOULD EXCEED HEAT ADVISORY CRITERIA EACH AFTERNOON THROUGH THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK. WITH SUCH STRONG RIDGE IN PLACE ALOFT...EXPECT CONVECTION TO REMAIN AT BAY. ALTHOUGH MODELS DO SHOW SOME POTENTIAL EACH AFTERNOON FROM SUNDAY ONWARDS AS UPPER RIDGE GETS SUPPRESSED A LITTLE FARTHER SOUTH AND SOUTHERLY RETURN FLOW PICKS UP IN TIGHTENED GRADIENT FLOW. IF ANY CLOUDS OR SHWRS DO DEVELOP IT WILL TAKE PLACE ALONG PIEDMONT TROUGH INLAND AND POSSIBLY ALONG CONVERGENT SEA BREEZE BOUNDARY CLOSER TO THE COAST. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...HIGH CLOUDS ARE PUSHING OFF THE COAST AT 06Z...AND SKC SHOULD CONTINUE FOR AT LEAST THE NEXT 24 HOURS. NORTHEAST SURFACE WINDS ARE THE RESULT OF FLOW BETWEEN TROPICAL DEPRESSION DEBBY ACROSS FLORIDA AND LARGE HIGH PRESSURE ACROSS THE OHIO VALLEY AND CENTRAL APPALACHIANS. NO OPERATIONAL IMPACTS FROM WEATHER ARE EXPECTED THROUGH TONIGHT. EXTENDED OUTLOOK...EXPECT VFR CONDITIONS WITH UNSEASONABLY HOT WEATHER DEVELOPING BY FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM WEDNESDAY...CURRENTLY WIND AND SEA OBSERVATIONS MATCH FORECASTS...NO UPDATES ARE NEEDED. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... TROPICAL DEPRESSION DEBBY IS INLAND ACROSS NORTH-CENTRAL FLORIDA THIS MORNING. OF MORE IMPORTANCE TO OUR WEATHER IS AN INVERTED SURFACE TROUGH THAT EXTENDS WELL NORTHEAST OF DEBBY ALONG THE GULF STREAM AS FAR NORTH AS SOUTH CAROLINA. A TIGHT PRESSURE GRADIENT BETWEEN THIS TROUGH AND HIGH PRESSURE IN THE OHIO VALLEY IS PRODUCING STRONG NORTHEAST WINDS THIS MORNING. AMONG OUR SUITE OF MODEL GUIDANCE THE GFS AND RUC APPEAR TO BE HANDLING CONDITIONS BEST AND THESE TWO MODELS WERE USED TO CONSTRUCT THE FORECAST TODAY. THE STRONGEST WINDS ARE EXPECTED TO OCCUR BETWEEN NOW AND 9 AM WITH 25-30 KNOT WINDS AND 6+ FOOT SEAS EXPECTED AWAY FROM SHORE. WIND GUSTS OVER 25 KNOTS ARE POSSIBLE EVEN NEARSHORE AT TIMES. WINDS SHOULD BEGIN TO ABATE LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON... AND I HAVE TENTATIVELY FORECAST SMALL CRAFT ADVISORY CONDITIONS TO END BY 5 PM. WINDS WILL BACK TO THE NORTH TONIGHT...THEN TO THE NORTHWEST LATE AS A LAND BREEZE SPREADS OFFSHORE. SEAS AT THE FRYING PAN SHOALS BUOY HAVE BUILT TO 8 FEET EARLY THIS MORNING...AND MAY BUILD TO 9 FEET OVER THE NEXT SEVERAL HOURS. WITHIN 20 MILES OF SHORE 6-7 FOOT SEAS ARE POSSIBLE...AND SOME 8-9 FOOT SEAS COULD EVEN DEVELOP EAST OF WINYAH BAY WHERE A PARTICULARLY LONG NORTHEAST FETCH WILL MAINTAIN ITSELF FOR 12-18 HOURS. ONCE WIND SPEEDS DIMINISH LATE THIS MORNING INTO THE AFTERNOON SEA HEIGHTS SHOULD SUBSIDE RATHER QUICKLY...WITH 2-4 FT SEAS EXPECTED AFTER MIDNIGHT TONIGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...DEBBY WILL MOVE OFF TO THE NORTHEAST INTO THE DISTANT ATLANTIC WHILE WEAK HIGH PRESSURE REMAINS OVER LOCAL WATERS. WILL SEE WINDS COMING AROUND ON THURS AS BERMUDA HIGH TAKES HOLD BY THE WEEKEND. THEREFORE LIGHT NORTHERLY WINDS EARLY THURS WILL BACK AROUND BECOMING MORE SOUTHERLY THROUGH FRI AND INCREASING UP TO 15 KTS. ANY RESIDUAL SWELL FROM DEBBY WILL SUBSIDE LEAVING SEAS AROUND 2 TO 3 FT OVER MOST WATERS BY LATE THURS INTO FRI. WITH SOME UNCERTAINTY AS TO THE STRENGTH AND TRACK OF DEBBY...WINDS AND SEAS MAY CHANGE. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 AM WEDNESDAY...MAY SEE SOME LONGER PERIOD SWELLS FROM DEBBY REACHING OUR LOCAL WATERS. THIS WILL DEPEND ON EXACT TRACK AND INTENSITY OF DEBBY AS THE SYSTEM MOVES NE FARTHER AWAY INTO THE ATLANTIC. OVERALL WILL SEE BERMUDA HIGH DOMINATE WITH INCREASING SOUTHERLY RETURN FLOW SETTING UP CLOSE TO 15 KTS. WINDS WILL INITIALLY BE MORE W-SW BUT WILL BACK TO THE SW THROUGH SUNDAY. SEAS 2 TO 3 FT MAY INCREASE UP TO 2 TO 4 FT BY SUN EVENING AS RETURN FLOW INCREASES AND BACKS BECOMING MORE SOUTHERLY. && .CLIMATE... RECORD HIGHS AT ILM... FRIDAY 101 (1959) SATURDAY 100(1959) SUNDAY 98 (1990) MONDAY 97 (1980) RECORD HIGHS AT FLO... FRIDAY 101 (1998) SATURDAY 103 (1990) SUNDAY 101 (1990) MONDAY 102 (1954) && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ250- 252-254-256. && $$ NEAR TERM...TRA SHORT TERM...RGZ LONG TERM...RGZ AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
353 AM EDT WED JUN 27 2012 .SYNOPSIS... AS HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM WEDNESDAY...THE CIRRUS SHIELD ASSOCIATED WITH TROPICAL DEPRESSION DEBBY AND THE INVERTED SURFACE TROUGH HAS PUSHED OFFSHORE THIS MORNING. IN ITS WAKE MUCH DRIER AIR HAS BUILT INTO THE EASTERN CAROLINAS WITH PRECIPITABLE WATER VALUES NOW AROUND 0.6 INCHES VERSUS 2.4 INCHES IN THE TROPICAL PLUME TO OUR SOUTH. DEBBY`S FORECAST PATH KEEPS THE SYSTEM AND ITS CLOUDINESS TOO FAR SOUTH AND EAST FOR ANY DIRECT IMPACTS ON OUR AREA. NORTHEAST BREEZES TODAY WILL BECOME LIGHT AND VARIABLE TONIGHT AS HIGH PRESSURE OVER THE OHIO VALLEY MOVES INTO THE CAROLINAS. HIGHS TODAY SHOULD REACH 85-87 INLAND...WITH 81-84 EXPECTED NEAR THE COAST. LOWS TONIGHT SHOULD FALL TO 59-65 WITH THE WARMEST READINGS ON THE BEACHES. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...HIGH PRESSURE AT THE SURFACE WILL WEAKEN OVER THE SOUTHEAST AS DEBBY SCOOTS OFF TO THE NORTHEAST INTO THE ATLANTIC THROUGH THE PERIOD. MEANWHILE IN THE MID TO UPPER LEVELS...STRONG RIDGE RUNNING UP THE MID WEST WILL SPREAD ACROSS MUCH OF THE SOUTHERN CONUS BUILDING EAST INTO THE CAROLINAS. THIS WILL BRING INCREASING H5 HEIGHTS REACHING UP AROUND 595 DEM OVER THE CAROLINAS BY LATE FRI WITH 850 TEMPS REACHING UP CLOSE TO 24C...PRODUCING THE HOTTEST WEATHER SO FAR THIS SUMMER...WITH POSSIBLE RECORD HEAT. SEE CLIMATE SECTION BELOW FOR RECORD VALUES. AFTER A COOL START THURS MORNING WITH TEMPS IN CLOSER TO 60...A HUGE DIURNAL SWING WILL OCCUR WITH TEMPS REACHING WELL INTO THE 90S BY AFTN. A RETURN FLOW WILL ALSO SET UP AT THE SURFACE WITH MOISTURE RETURNING. DEWPOINT TEMPS WILL RISE A GOOD 15 DEGREES FROM EARLY THURS TO LATE FRI. BY FRI AFTN...MOST AREAS WILL MOST LIKELY REACH HEAT ADVISORY CRITERIA WITH MAX TEMPS REACHING ABOVE 100...ESPECIALLY INLAND. WITH SUCH A STRONG RIDGE BUILDING OVERHEAD AND PLENTY OF DRY AIR AND SUBSIDENCE ALOFT...NOT EXPECTING ANY PCP THROUGH THE PERIOD. WILL BE HARD PRESSED TO SEE MUCH IN THE WAY OF ANY CLOUDS BUT WITH PIEDMONT TROUGH EVIDENT INLAND EACH DAY AND SEA BREEZE CLOSER TO THE COAST...MAY HAVE JUST ENOUGH CONVERGENCE IN THE VERY LOW LEVELS TO SEE A FEW CU AROUND. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY...SOUTHERLY RETURN FLOW WILL PREVAIL AT THE SURFACE AS BERMUDA HIGH DOMINATES WHILE THE PIEDMONT TROUGH IS EVIDENT EACH AFTERNOON OVER INLAND CAROLINAS. RIDGE ALOFT CONTINUES TO BUILD OVER THE SOUTHEAST WITH H5 HEIGHTS REACHING UP AROUND 25 C AND 850 TEMPS CONTINUING TO RISE THROUGH THE WEEKEND...LEADING TO RECORD HEAT POSSIBLE. SEE CLIMATE SECTION BELOW. LATEST GUIDANCE SHOWS WARMEST DAYS OVER THE WEEKEND WITH TEMPS REACHING ABOVE 100. WINDS IN THE LOWER LEVELS WILL ALSO HAVE AN INCREASING WESTERLY DOWNSLOPE COMPONENT WHICH WILL ALSO AID IN ENHANCING THE HEAT. WITH A MOIST SOUTHERLY RETURN FLOW SETTING UP...DEWPOINT TEMPS WILL ALSO RISE INTO THE MID 70S AND CLOSE TO 80 RIGHT ALONG THE COAST. THIS WILL PRODUCE APPARENT TEMPERATURES ABOVE 105 DEGREES IN MOST PLACES AND CLOSER TO 110 FURTHER INLAND. SOME PLACES MAY SEE APPARENT TEMPS UP CLOSE TO 115 DEGREES AS SEA BREEZE CARRIES IN HIGHER DEWPOINT AIR. SHOULD EXCEED HEAT ADVISORY CRITERIA EACH AFTERNOON THROUGH THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK. WITH SUCH STRONG RIDGE IN PLACE ALOFT...EXPECT CONVECTION TO REMAIN AT BAY. ALTHOUGH MODELS DO SHOW SOME POTENTIAL EACH AFTERNOON FROM SUNDAY ONWARDS AS UPPER RIDGE GETS SUPPRESSED A LITTLE FARTHER SOUTH AND SOUTHERLY RETURN FLOW PICKS UP IN TIGHTENED GRADIENT FLOW. IF ANY CLOUDS OR SHWRS DO DEVELOP IT WILL TAKE PLACE ALONG PIEDMONT TROUGH INLAND AND POSSIBLY ALONG CONVERGENT SEA BREEZE BOUNDARY CLOSER TO THE COAST. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...HIGH CLOUDS ARE PUSHING OFF THE COAST AT 06Z...AND SKC SHOULD CONTINUE FOR AT LEAST THE NEXT 24 HOURS. NORTHEAST SURFACE WINDS ARE THE RESULT OF FLOW BETWEEN TROPICAL DEPRESSION DEBBY ACROSS FLORIDA AND LARGE HIGH PRESSURE ACROSS THE OHIO VALLEY AND CENTRAL APPALACHIANS. NO OPERATIONAL IMPACTS FROM WEATHER ARE EXPECTED THROUGH TONIGHT. EXTENDED OUTLOOK...EXPECT VFR CONDITIONS WITH UNSEASONABLY HOT WEATHER DEVELOPING BY FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM WEDNESDAY...TROPICAL DEPRESSION DEBBY IS INLAND ACROSS NORTH-CENTRAL FLORIDA THIS MORNING. OF MORE IMPORTANCE TO OUR WEATHER IS AN INVERTED SURFACE TROUGH THAT EXTENDS WELL NORTHEAST OF DEBBY ALONG THE GULF STREAM AS FAR NORTH AS SOUTH CAROLINA. A TIGHT PRESSURE GRADIENT BETWEEN THIS TROUGH AND HIGH PRESSURE IN THE OHIO VALLEY IS PRODUCING STRONG NORTHEAST WINDS THIS MORNING. AMONG OUR SUITE OF MODEL GUIDANCE THE GFS AND RUC APPEAR TO BE HANDLING CONDITIONS BEST AND THESE TWO MODELS WERE USED TO CONSTRUCT THE FORECAST TODAY. THE STRONGEST WINDS ARE EXPECTED TO OCCUR BETWEEN NOW AND 9 AM WITH 25-30 KNOT WINDS AND 6+ FOOT SEAS EXPECTED AWAY FROM SHORE. WIND GUSTS OVER 25 KNOTS ARE POSSIBLE EVEN NEARSHORE AT TIMES. WINDS SHOULD BEGIN TO ABATE LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON... AND I HAVE TENTATIVELY FORECAST SMALL CRAFT ADVISORY CONDITIONS TO END BY 5 PM. WINDS WILL BACK TO THE NORTH TONIGHT...THEN TO THE NORTHWEST LATE AS A LAND BREEZE SPREADS OFFSHORE. SEAS AT THE FRYING PAN SHOALS BUOY HAVE BUILT TO 8 FEET EARLY THIS MORNING...AND MAY BUILD TO 9 FEET OVER THE NEXT SEVERAL HOURS. WITHIN 20 MILES OF SHORE 6-7 FOOT SEAS ARE POSSIBLE...AND SOME 8-9 FOOT SEAS COULD EVEN DEVELOP EAST OF WINYAH BAY WHERE A PARTICULARLY LONG NORTHEAST FETCH WILL MAINTAIN ITSELF FOR 12-18 HOURS. ONCE WIND SPEEDS DIMINISH LATE THIS MORNING INTO THE AFTERNOON SEA HEIGHTS SHOULD SUBSIDE RATHER QUICKLY...WITH 2-4 FT SEAS EXPECTED AFTER MIDNIGHT TONIGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...DEBBY WILL MOVE OFF TO THE NORTHEAST INTO THE DISTANT ATLANTIC WHILE WEAK HIGH PRESSURE REMAINS OVER LOCAL WATERS. WILL SEE WINDS COMING AROUND ON THURS AS BERMUDA HIGH TAKES HOLD BY THE WEEKEND. THEREFORE LIGHT NORTHERLY WINDS EARLY THURS WILL BACK AROUND BECOMING MORE SOUTHERLY THROUGH FRI AND INCREASING UP TO 15 KTS. ANY RESIDUAL SWELL FROM DEBBY WILL SUBSIDE LEAVING SEAS AROUND 2 TO 3 FT OVER MOST WATERS BY LATE THURS INTO FRI. WITH SOME UNCERTAINTY AS TO THE STRENGTH AND TRACK OF DEBBY...WINDS AND SEAS MAY CHANGE. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 AM WEDNESDAY...MAY SEE SOME LONGER PERIOD SWELLS FROM DEBBY REACHING OUR LOCAL WATERS. THIS WILL DEPEND ON EXACT TRACK AND INTENSITY OF DEBBY AS THE SYSTEM MOVES NE FARTHER AWAY INTO THE ATLANTIC. OVERALL WILL SEE BERMUDA HIGH DOMINATE WITH INCREASING SOUTHERLY RETURN FLOW SETTING UP CLOSE TO 15 KTS. WINDS WILL INITIALLY BE MORE W-SW BUT WILL BACK TO THE SW THROUGH SUNDAY. SEAS 2 TO 3 FT MAY INCREASE UP TO 2 TO 4 FT BY SUN EVENING AS RETURN FLOW INCREASES AND BACKS BECOMING MORE SOUTHERLY. && .CLIMATE... RECORD HIGHS AT ILM... FRIDAY 101 (1959) SATURDAY 100(1959) SUNDAY 98 (1990) MONDAY 97 (1980) RECORD HIGHS AT FLO... FRIDAY 101 (1998) SATURDAY 103 (1990) SUNDAY 101 (1990) MONDAY 102 (1954) && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ250- 252-254-256. && $$ NEAR TERM...TRA SHORT TERM...RGZ LONG TERM...RGZ AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1204 PM CDT WED JUN 27 2012 .UPDATE... MADE A FEW CHANGES TO THE FORECAST THIS MORNING. AN AREA OF LOW PRESSURE AND SURFACE FRONTAL BOUNDARY HAS MOVED ACROSS MOST OF THIS CWA...WITH SEVERAL LOCATIONS REPORTING NORTHERLY WINDS. THAT SAID...A MOISTURE GRADIENT ALONG WITH FRONTOGENISIS AT H85 HAS RESULTED IN ELEVATED CONVECTION. BASED ON RADAR TRENDS BELIEVE VERY LITTLE PCPN IS ACTUALLY REACHING THE GROUND. WILL TOSS IN ISOLATED THUNDER INTO THE FORECAST FOR NOW. 18Z AVIATION DISCUSSION HAS BEEN POSTED BELOW... && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH FRIDAY FRONTAL BOUNDARY IS TRACKING EAST ACROSS THE AREA EARLY THIS MORNING AND IS JUST CROSSING THE MISSOURI RIVER AS KMBG HAS RECENTLY TURNED TO NORTHWEST WINDS. MARKEDLY DRIER BEHIND THE FRONT WITH DEWPOINTS IN THE 40S AND 50S VS THE 60S AND 70S AHEAD OF IT. SATELLITE IMAGERY HAS SHOWN ACCAS DEVELOPMENT ACROSS SOUTHERN SD FOR THE PAST SEVERAL HOURS AND RECENTLY ISO THUNDERSHOWERS HAVE DEVELOPED ACROSS SOUTHWEST SD. THERE IS AN OMEGA BULLSEYE AT 700 MB IN THIS REGION WITH A WEAK VORT MAXIMA. INSERTED SLIGHT CHANCE POPS ACROSS THE SOUTHWEST CWA UP THROUGH 12Z THIS MORNING AND WILL SEE HOW THIS EVOLVES. 00Z NAM TRIED TO SHOW A FEW SPOTTY SHOWERS ACROSS THE WESTERN CWA THROUGH THE MORNING HOURS BUT 06Z RUN BACKED OFF. HRRR ALSO SHOWING A FEW SPRINKLES/LIGHT SHOWERS. FRONT WILL CONTINUE THROUGH THE REGION DURING THE MORNING HOURS AS DRIER AIR ADVECTS ACROSS THE CWA. WILL SEE BREEZY NORTHWEST WINDS THROUGH THE DAY WITH MUCH LOWER DEWPOINTS OVER THE WESTERN CWA. IT WILL STILL TAKE A GOOD PART OF THE DAY TO SCOUR OUT THE HIGHER DEWPOINTS ACROSS THE EASTERN CWA BUT WILL SEE A DECENT FALL IN DEWPOINTS THROUGHOUT THE AFTERNOON. RH VALUES WILL ACTUALLY GET RATHER LOW OVER THE WESTERN CWA TODAY WITH READINGS AROUND 20 PERCENT. WIND GUSTS APPEAR TO SLOWLY DIMINISH THROUGH THE AFTERNOON. LATEST FUELS STATUS UPDATE DOES STILL INDICATE A NO ACROSS THE WESTERN FIRE ZONES...BUT THIS WAS A COUPLE WEEKS AGO. WILL NOT ISSUE ANY FIRE WEATHER HEADLINES AT THIS TIME. HIGH PRESSURE SETTLES OVER THE AREA TONIGHT BRINGING FAIRLY LIGHT WINDS AND MOSTLY CLEAR SKIES. COOLER OVERNIGHT LOWS EXPECTED IN THE UPPER 50S AND 60S. SFC HIGH REMAINS OVER THE AREA ON THURSDAY WHICH WILL KEEP THE WEATHER QUIET...WITH CONTINUED WARM TEMPERATURES. BY FRIDAY...WEAK SFC LOW KICKS OUT ACROSS SD WITH A WARM FRONT EXTENDING EASTWARD THROUGH THE REGION. MODELS SHOWING CONVECTION FIRING DURING THE AFTERNOON HOURS NEAR THE WARM FRONT. WILL KEEP 20/30 POPS IN THE FORECAST FOR THIS. .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY GENERALLY SPEAKING THE MODELS ARE SIMILAR IN THEIR DEPICTIONS OF THE MID LEVEL FLOW PATTERN ACROSS THE NORTHERN CONUS. A BROAD MID LEVEL RIDGE IS EXPECTED TO PERSIST ACROSS THE REGION THROUGH THE PERIOD...AND MAY EVEN EXPAND NORTH LATE IN THE PERIOD. WHAT THIS MEANS IS THAT THE MID LEVEL THERMAL RIDGE WILL SLOWLY BE STRENGTHENING WITH TIME. HOWEVER...RIDGE RIDER SHORT WAVES COULD PROVIDE FOR SURPRISE CONVECTION AT JUST ABOUT ANYTIME. THAT SAID THERE IS PRETTY GOOD INDICATION BY THE GFS/ECMWF THAT THE HIGHEST PROBABILITIES FOR ANY MEASURABLE PCPN WILL BE FRIDAY NIGHT AND AGAIN LATE SATURDAY INTO SATURDAY NIGHT AS ENERGY PROPAGATES THROUGH THE RIDGE. AFTER SATURDAY NIGHT CONVECTION CHANCES BECOME MUCH MORE PROBLEMATIC WITH INCREASING HEIGHTS AND MID LEVEL TEMPS. GIVEN THE FORECAST HEIGHTS/TEMPS ALOFT...SUSPECT THAT TEMPERATURES WILL BE MOSTLY ABOVE NORMAL THROUGH THE ENTIRE PERIOD. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITION EXPECTED. A FEW HIGH BASED SHOWERS PASSING THOUGH THE AREA TODAY WILL BE RESPONSIBLE FOR THE ODD LIGHTNING STRIKE AND/OR ERRATIC WINDS...WHICH WILL BE LOCALIZED TO THE STRONGEST CELLS. PREDOMINANTLY NORTHWEST WINDS EARLY TODAY WILL WEAKEN THIS EVENING AND GRADUALLY SHIFT AROUND TO THE SOUTHEAST BY THE END OF THE TAF PERIOD. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...SD SHORT TERM...TMT LONG TERM...TDK AVIATION...CONNELLY WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1054 AM CDT WED JUN 27 2012 .UPDATE... MADE A FEW CHANGES TO THE FORECAST THIS MORNING. AN AREA OF LOW PRESSURE AND SURFACE FRONTAL BOUNDARY HAS MOVED ACROSS MOST OF THIS CWA...WITH SEVERAL LOCATIONS REPORTING NORTHERLY WINDS. THAT SAID...A MOISTURE GRADIENT ALONG WITH FRONTOGENESIS AT H85 HAS RESULTED IN ELEVATED CONVECTION. BASED ON RADAR TRENDS BELIEVE VERY LITTLE PCPN IS ACTUALLY REACHING THE GROUND. WILL TOSS IN ISOLATED THUNDER INTO THE FORECAST FOR NOW. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH FRIDAY FRONTAL BOUNDARY IS TRACKING EAST ACROSS THE AREA EARLY THIS MORNING AND IS JUST CROSSING THE MISSOURI RIVER AS KMBG HAS RECENTLY TURNED TO NORTHWEST WINDS. MARKEDLY DRIER BEHIND THE FRONT WITH DEWPOINTS IN THE 40S AND 50S VS THE 60S AND 70S AHEAD OF IT. SATELLITE IMAGERY HAS SHOWN ACCAS DEVELOPMENT ACROSS SOUTHERN SD FOR THE PAST SEVERAL HOURS AND RECENTLY ISO THUNDERSHOWERS HAVE DEVELOPED ACROSS SOUTHWEST SD. THERE IS AN OMEGA BULLSEYE AT 700 MB IN THIS REGION WITH A WEAK VORT MAXIMA. INSERTED SLIGHT CHANCE POPS ACROSS THE SOUTHWEST CWA UP THROUGH 12Z THIS MORNING AND WILL SEE HOW THIS EVOLVES. 00Z NAM TRIED TO SHOW A FEW SPOTTY SHOWERS ACROSS THE WESTERN CWA THROUGH THE MORNING HOURS BUT 06Z RUN BACKED OFF. HRRR ALSO SHOWING A FEW SPRINKLES/LIGHT SHOWERS. FRONT WILL CONTINUE THROUGH THE REGION DURING THE MORNING HOURS AS DRIER AIR ADVECTS ACROSS THE CWA. WILL SEE BREEZY NORTHWEST WINDS THROUGH THE DAY WITH MUCH LOWER DEWPOINTS OVER THE WESTERN CWA. IT WILL STILL TAKE A GOOD PART OF THE DAY TO SCOUR OUT THE HIGHER DEWPOINTS ACROSS THE EASTERN CWA BUT WILL SEE A DECENT FALL IN DEWPOINTS THROUGHOUT THE AFTERNOON. RH VALUES WILL ACTUALLY GET RATHER LOW OVER THE WESTERN CWA TODAY WITH READINGS AROUND 20 PERCENT. WIND GUSTS APPEAR TO SLOWLY DIMINISH THROUGH THE AFTERNOON. LATEST FUELS STATUS UPDATE DOES STILL INDICATE A NO ACROSS THE WESTERN FIRE ZONES...BUT THIS WAS A COUPLE WEEKS AGO. WILL NOT ISSUE ANY FIRE WEATHER HEADLINES AT THIS TIME. HIGH PRESSURE SETTLES OVER THE AREA TONIGHT BRINGING FAIRLY LIGHT WINDS AND MOSTLY CLEAR SKIES. COOLER OVERNIGHT LOWS EXPECTED IN THE UPPER 50S AND 60S. SFC HIGH REMAINS OVER THE AREA ON THURSDAY WHICH WILL KEEP THE WEATHER QUIET...WITH CONTINUED WARM TEMPERATURES. BY FRIDAY...WEAK SFC LOW KICKS OUT ACROSS SD WITH A WARM FRONT EXTENDING EASTWARD THROUGH THE REGION. MODELS SHOWING CONVECTION FIRING DURING THE AFTERNOON HOURS NEAR THE WARM FRONT. WILL KEEP 20/30 POPS IN THE FORECAST FOR THIS. .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY GENERALLY SPEAKING THE MODELS ARE SIMILAR IN THEIR DEPICTIONS OF THE MID LEVEL FLOW PATTERN ACROSS THE NORTHERN CONUS. A BROAD MID LEVEL RIDGE IS EXPECTED TO PERSIST ACROSS THE REGION THROUGH THE PERIOD...AND MAY EVEN EXPAND NORTH LATE IN THE PERIOD. WHAT THIS MEANS IS THAT THE MID LEVEL THERMAL RIDGE WILL SLOWLY BE STRENGTHENING WITH TIME. HOWEVER...RIDGE RIDER SHORT WAVES COULD PROVIDE FOR SURPRISE CONVECTION AT JUST ABOUT ANYTIME. THAT SAID THERE IS PRETTY GOOD INDICATION BY THE GFS/ECMWF THAT THE HIGHEST PROBABILITIES FOR ANY MEASURABLE PCPN WILL BE FRIDAY NIGHT AND AGAIN LATE SATURDAY INTO SATURDAY NIGHT AS ENERGY PROPAGATES THROUGH THE RIDGE. AFTER SATURDAY NIGHT CONVECTION CHANCES BECOME MUCH MORE PROBLEMATIC WITH INCREASING HEIGHTS AND MID LEVEL TEMPS. GIVEN THE FORECAST HEIGHTS/TEMPS ALOFT...SUSPECT THAT TEMPERATURES WILL BE MOSTLY ABOVE NORMAL THROUGH THE ENTIRE PERIOD. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TODAY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...SD SHORT TERM...TMT LONG TERM...TDK AVIATION...TDK WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
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
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
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
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1206 PM CDT WED JUN 27 2012 .AVIATION... VFR CONDITIONS TO PREVAIL FOR ALL TERMINALS THROUGHOUT THE TAF PERIOD. SURFACE HIGH TO PROGRESS EASTWARD WHICH WILL INCREASE WIND FIELDS A BIT AND FROM THE EAST AROUND 15Z TOMORROW. NO OTHER IMPACTS ANTICIPATED AT THIS TIME. && .PREV DISCUSSION... /ISSUED 1107 AM CDT WED JUN 27 2012/ UPDATE... 15Z DEWPOINTS ARE ALREADY BELOW GUIDANCE FOR BOTH MAV AND MET BUT CLOSER TO MET SO AUGMENTED TD GRIDS TO REFLECT THAT DRYING. MODELS TRY TO RECOVER MOISTURE OVER THE COURSE OF THE DAY BUT WITH THE UL HIGH INCHING CLOSER AND THE SFC HIGH INHIBITING ANY SORT OF WIND FIELD...CANNOT REASON AS TO WHY WE WOULD RECOVER. STRENGTHENING PRESSURE GRADIENT IN THE NORTHWEST WILL ENHANCE SOUTHERLY FLOW IN THAT AREA BUT RUC AND NAM DO NOT INCREASE OUR GRADIENT THIS FAR SOUTH. ALSO RAISED MIN T GRID A DEGREE DUE TO LATEST MODEL WARMING BUT STILL BELOW GUIDANCE DUE TO THE DRIER CONDITIONS. PREV DISCUSSION... /ISSUED 610 AM CDT WED JUN 27 2012/ UPDATE...ADDED AVIATION SECTION FOR 12 TAF`S. AVIATION...BNA/CKV/CSV...SURFACE RIDGE LOCKED IN PLACE OVER MIDDLE TENNESSEE TODAY, WITH GENERALLY LIGHT WINDS AND VFR WX THE NEXT 24 HRS. PREV DISCUSSION... /ISSUED 258 AM CDT WED JUN 27 2012/ HEAT WAVE AND DROUGHT WILL DOMINATE THE NEXT SEVEN DAYS... SHORT TERM...IT`S HARD TO COMPLAIN ABOUT THE WEATHER THIS MORNING, AS LOW DEW POINTS AND CLEAR SKIES HAVE ALLOWED TEMPERATURES TO SINK INTO THE MIDDLE 50S TO MIDDLE 60S. HOWEVER, ONCE THE SUN TOPS THE HORIZON THINGS WILL START TO CHANGE IN A HURRY. LOOKS LIKE OUR HUMONGOUS UPPER RIDGE WILL STILL BUILD EASTWARD, OUT OF THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY ACROSS MIDDLE TENNESSEE OVER THE NEXT SEVERAL DAYS. AS CENTER OF RIDGE MOVES ACROSS THE MID STATE, EXPECT HIGH TEMPERATURES TO SOAR AT LEAST SIX DEGREES ABOVE YESTERDAY`S READINGS, ADDING ANOTHER SIX DEGREES ON THURSDAY, AND ANOTHER THREE DEGREES ON FRIDAY. AS RIDGE BUILDS EASTWARD, OUR HOTTEST WEATHER WILL BE OVER WESTERN PARTS OF THE MID STATE, GENERALLY FROM I-65 TO THE TENNESSEE RIVER. HIGH TEMPERATURES IN THOSE AREAS WILL REACH THE MIDDLE 90S TODAY, AROUND 100 ON THURSDAY AND AROUND 103 DEGREES ON FRIDAY! THE NORMALLY-COOLER CUMBERLAND PLATEAU WILL NOT ESCAPE THE HEAT, AS HIGHS ARE FORECAST TO PUSH FROM THE MID 80S TODAY TO THE UPPER 90S BY FRIDAY. BIG DOME OF HIGH PRESSURE WILL PROVIDE MASSIVE SUBSIDENCE, CLEAR SKIES AND A COMPLETE ABSENCE OF RAINFALL THROUGH AT LEAST SATURDAY, WILL ONLY A PIDDLY CHANCE FOR SHOWERS ALONG THE CUMBERLAND PLATEAU BY EARLY NEXT WEEK. NEAR RECORD TEMPERATURES ARE EXPECTED FRIDAY, WITH NASHVILLE POISED TO AT LEAST TIE THE OLD RECORD OF 103 DEGREES (SET IN 1952) AND CROSSVILLE LIKELY TO BREAK THEIR OLD RECORD OF 92 (SET IN 1988). LONG TERM...IT APPEARED YESTERDAY THAT UPPER FLOW MIGHT BECOME MORE NORTHWESTERLY ACROSS THE MID STATE BY THE EXTENDED PERIOD, AND ALLOW FOR THE POTENTIAL FOR SCATTERED THUNDERSTORMS AT SOME POINT. HOWEVER, MODELS NOW KEEP HUMONGOUS RIDGE PRETTY MUCH ANCHORED OVER THE GULF COAST, TENNESSEE RIVER VALLEY, MIDDLE MISSISSIPPI VALLEY AND THE SOUTHERN AND CENTRAL PLAINS. THUS, HAVE TRIMMED PRECIP EXPECTATIONS TO JUST A SLIGHT CHANCE ALONG THE CUMBERLAND PLATEAU BY THE LATTER PERIODS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TB12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1107 AM CDT WED JUN 27 2012 .UPDATE... 15Z DEWPOINTS ARE ALREADY BELOW GUIDANCE FOR BOTH MAV AND MET BUT CLOSER TO MET SO AUGMENTED TD GRIDS TO REFLECT THAT DRYING. MODELS TRY TO RECOVER MOISTURE OVER THE COURSE OF THE DAY BUT WITH THE UL HIGH INCHING CLOSER AND THE SFC HIGH INHIBITING ANY SORT OF WIND FIELD...CANNOT REASON AS TO WHY WE WOULD RECOVER. STRENGTHENING PRESSURE GRADIENT IN THE NORTHWEST WILL ENHANCE SOUTHERLY FLOW IN THAT AREA BUT RUC AND NAM DO NOT INCREASE OUR GRADIENT THIS FAR SOUTH. ALSO RAISED MIN T GRID A DEGREE DUE TO LATEST MODEL WARMING BUT STILL BELOW GUIDANCE DUE TO THE DRIER CONDITIONS. && .PREV DISCUSSION... /ISSUED 610 AM CDT WED JUN 27 2012/ UPDATE...ADDED AVIATION SECTION FOR 12 TAF`S. AVIATION...BNA/CKV/CSV...SURFACE RIDGE LOCKED IN PLACE OVER MIDDLE TENNESSEE TODAY, WITH GENERALLY LIGHT WINDS AND VFR WX THE NEXT 24 HRS. PREV DISCUSSION... /ISSUED 258 AM CDT WED JUN 27 2012/ .HEAT WAVE AND DROUGHT WILL DOMINATE THE NEXT SEVEN DAYS... SHORT TERM...IT`S HARD TO COMPLAIN ABOUT THE WEATHER THIS MORNING, AS LOW DEW POINTS AND CLEAR SKIES HAVE ALLOWED TEMPERATURES TO SINK INTO THE MIDDLE 50S TO MIDDLE 60S. HOWEVER, ONCE THE SUN TOPS THE HORIZON THINGS WILL START TO CHANGE IN A HURRY. LOOKS LIKE OUR HUMONGOUS UPPER RIDGE WILL STILL BUILD EASTWARD, OUT OF THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY ACROSS MIDDLE TENNESSEE OVER THE NEXT SEVERAL DAYS. AS CENTER OF RIDGE MOVES ACROSS THE MID STATE, EXPECT HIGH TEMPERATURES TO SOAR AT LEAST SIX DEGREES ABOVE YESTERDAY`S READINGS, ADDING ANOTHER SIX DEGREES ON THURSDAY, AND ANOTHER THREE DEGREES ON FRIDAY. AS RIDGE BUILDS EASTWARD, OUR HOTTEST WEATHER WILL BE OVER WESTERN PARTS OF THE MID STATE, GENERALLY FROM I-65 TO THE TENNESSEE RIVER. HIGH TEMPERATURES IN THOSE AREAS WILL REACH THE MIDDLE 90S TODAY, AROUND 100 ON THURSDAY AND AROUND 103 DEGREES ON FRIDAY! THE NORMALLY-COOLER CUMBERLAND PLATEAU WILL NOT ESCAPE THE HEAT, AS HIGHS ARE FORECAST TO PUSH FROM THE MID 80S TODAY TO THE UPPER 90S BY FRIDAY. BIG DOME OF HIGH PRESSURE WILL PROVIDE MASSIVE SUBSIDENCE, CLEAR SKIES AND A COMPLETE ABSENCE OF RAINFALL THROUGH AT LEAST SATURDAY, WILL ONLY A PIDDLY CHANCE FOR SHOWERS ALONG THE CUMBERLAND PLATEAU BY EARLY NEXT WEEK. NEAR RECORD TEMPERATURES ARE EXPECTED FRIDAY, WITH NASHVILLE POISED TO AT LEAST TIE THE OLD RECORD OF 103 DEGREES (SET IN 1952) AND CROSSVILLE LIKELY TO BREAK THEIR OLD RECORD OF 92 (SET IN 1988). LONG TERM...IT APPEARED YESTERDAY THAT UPPER FLOW MIGHT BECOME MORE NORTHWESTERLY ACROSS THE MID STATE BY THE EXTENDED PERIOD, AND ALLOW FOR THE POTENTIAL FOR SCATTERED THUNDERSTORMS AT SOME POINT. HOWEVER, MODELS NOW KEEP HUMONGOUS RIDGE PRETTY MUCH ANCHORED OVER THE GULF COAST, TENNESSEE RIVER VALLEY, MIDDLE MISSISSIPPI VALLEY AND THE SOUTHERN AND CENTRAL PLAINS. THUS, HAVE TRIMMED PRECIP EXPECTATIONS TO JUST A SLIGHT CHANCE ALONG THE CUMBERLAND PLATEAU BY THE LATTER PERIODS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TB12
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1049 AM PDT Wed Jun 27 2012 .SYNOPSIS... A more seasonable weather pattern is expected through the middle of next week. Drier and warmer weather will move into the area for the rest of the work week. Then a system will move in this weekend bringing a chance of showers and thunderstorms to the Inland Northwest. && .DISCUSSION... A quick update to remove fog and showers from the forecast through the rest of the morning. The HRRR model continues to show some light convective shower activity across the northern mountains; however, it looks as if this model is overdoing the moisture a bit at lower levels. Both the NAM and the GFS show a drier sounding with decreasing dew point temperatures through this afternoon. A drier solution seems to make better sense behind the exiting system that moved through yesterday. We will continue to see some flat cumulus developing through the day across the northern mountains, Spokane Area, Palouse and over the Idaho Panhandle. Temperatures look to be on track; although they looked a touch too cool across northern Idaho per latest model guidance, thus I increased highs by a degree or two at Sandpoint and Bonners Ferry. /SVH && .AVIATION... 18z TAFS: Shallow cumulus developing this morning around the KGEG, KSFF, KCOE and KPUW taf sites may result in brief MVFR cigs at around 3 kft through 19z. We will then see these cigs rise through the afternoon as the surface warms with VFR conditions expected at all taf sites through 18z Thursday. Cumulus cloud cover will diminish after 00z as we dry out low and mid levels this afternoon. We may see some low stratus or fog developing tonight in the northern valleys, but this will be less widespread than this morning due to the drier boundary layer conditions. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 70 50 79 54 76 54 / 0 0 0 10 10 10 Coeur d`Alene 68 46 80 54 76 55 / 10 0 0 10 10 10 Pullman 70 43 77 52 75 53 / 0 0 0 0 10 0 Lewiston 78 53 85 60 84 63 / 0 0 0 0 10 0 Colville 71 47 81 52 80 53 / 10 0 0 10 10 10 Sandpoint 65 39 80 52 76 51 / 10 0 0 10 10 10 Kellogg 67 45 81 51 74 52 / 10 0 0 10 10 10 Moses Lake 75 48 85 57 81 58 / 0 0 0 10 10 10 Wenatchee 75 54 82 59 84 59 / 0 0 0 0 10 10 Omak 75 46 83 54 83 55 / 0 0 0 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
959 AM PDT Wed Jun 27 2012 .SYNOPSIS... A more seasonable weather pattern is expected through the middle of next week. Drier and warmer weather will move into the area for the rest of the work week. Then a system will move in this weekend bringing a chance of showers and thunderstorms to the Inland Northwest. && .DISCUSSION... A quick update to remove fog and showers from the forecast through the rest of the morning. The HRRR model continues to show some light convective shower activity across the northern mountains; however, it looks as if this model is overdoing the moisture a bit at lower levels. Both the NAM and the GFS show a drier sounding with decreasing dew point temperatures through this afternoon. A drier solution seems to make better sense behind the exiting system that moved through yesterday. We will continue to see some flat cumulus developing through the day across the northern mountains, Spokane Area, Palouse and over the Idaho Panhandle. Temperatures look to be on track; although they looked a touch too cool across northern Idaho per latest model guidance, thus I increased highs by a degree or two at Sandpoint and Bonners Ferry. /SVH && .AVIATION... 12z TAFS: Abundant low level moisture across NE Washington and N Idaho will result in areas of stratus and MVFR CIGS through 18z. As of 11z MVFR CIGS have been confined north of the KGEG-KCOE corridor and with model trends showing drying in the boundary layer 15-18z opted to leave CIGS as VFR for all TAF sites. Fog product satellite at 11z indicated patchy fog east of KLWS so indicated BCFG in the TAF. As a short wave ridge builds in today look for gradually rising CIGS with cumulus dissipating between 0-6z due to mid level drying and stabilizing lower levels. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 70 50 79 54 76 54 / 0 0 0 10 10 10 Coeur d`Alene 68 46 80 54 76 55 / 10 0 0 10 10 10 Pullman 70 43 77 52 75 53 / 0 0 0 0 10 0 Lewiston 78 53 85 60 84 63 / 0 0 0 0 10 0 Colville 71 47 81 52 80 53 / 10 0 0 10 10 10 Sandpoint 65 39 80 52 76 51 / 10 0 0 10 10 10 Kellogg 67 45 81 51 74 52 / 10 0 0 10 10 10 Moses Lake 75 48 85 57 81 58 / 0 0 0 10 10 10 Wenatchee 75 54 82 59 84 59 / 0 0 0 0 10 10 Omak 75 46 83 54 83 55 / 0 0 0 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT WED JUN 27 2012 .SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT 319 PM CDT WED JUN 27 2012 MAIN FORECAST CONCERN CONTINUES TO BE FOCUSED ON HEAT THROUGH THURSDAY...ALONG WITH LOW-END RAIN CHANCES TONIGHT THROUGH SATURDAY. LARGE SCALE WATER VAPOR IMAGERY/RAP ANALYSIS HAS A FAIRLY AMPLIFIED RIDGE OF HIGH PRESSURE OVER THE MID-SECTION OF THE CONUS/UPPER MISSISSIPPI RIVER VALLEY REGION. A PLUME OF SUBTROPICAL MOISTURE WAS ALSO SEEN EXTEND AROUND THE BACKSIDE OF THE RIDGE FROM THE BAJA INTO THE DAKOTAS/WESTERN MN. AT THE SURFACE...A COLD FRONT EXTENDED FROM WESTERN MN INTO CENTRAL NEB. WARM AIR ADVECTION AHEAD OF THE FRONT AND COMPRESSIONAL HEATING UNDER THE RIDGE WAS PRODUCING VERY WARM TEMPERATURES ACROSS THE AREA AT 3 PM RANGED FROM 84 DEGREES AT MEDFORD WI...TO AS HIGH AS 95 DEGREES AT BOSCOBEL WI. HEAT INDICES RANGED FROM 95 TO 105 DEGREES ALONG AND WEST OF THE MISSISSIPPI RIVER. AS A RESULT...WILL LEAVE HEAT ADVISORY AS IS ACROSS THIS AREA...WHICH WILL EXPIRE AT 8 PM THIS EVENING. FOR THE REMAINDER OF THE NIGHT...WILL BE WATCHING THE COLD FRONT OVER WESTERN MN MOVE EAST...EXTENDING FROM NORTHEAST WI THROUGH SOUTHWEST WI/NORTHEAST IA BY 12Z. A BAND OF ELEVATED CONVECTION/ACCAS IS EXPECTED TO ACCOMPANY THE FRONT AS MOISTURE POOLS ALONG THE FRONT. BUFKIT SHOWS THE BASE OF THIS CLOUD TO BE ABOVE 12KFT WITH A RATHER STOUT CAP REMAINING IN PLACE AROUND 800MB. CURRENT THINKING IS THAT THIS SHRA ACTIVITY WILL REMAIN IN VIRGA FORM...EVAPORATING BEFORE REACHING THE GROUND. NONETHELESS A FEW MEASURABLE SHRA COULD REACH THE GROUND. WILL GO WITH A SLIGHT CHANCE OF SHRA/TS THEN AFTER MIDNIGHT TO COVER THIS SCENARIO. OTHERWISE...LOOK FOR TEMPERATURES TO ONLY COOL INTO THE 70S. FOR THURSDAY...APPEARS THE COLD FRONT WILL CONTINUE PUSHING SOUTH AND EAST INTO SOUTHERN WI/NORTHEAST WI BY AFTERNOON. NAM 0-1KM MLCAPE PUSHING INTO THE 3500-5000J/KG RANGE AHEAD OF THE FRONT WITH AROUND 30KT OF 0-3KM BULK SHEAR. AT THE SAME TIME...BUFKIT SHOWING A FAIRLY STRONG CAP IN PLACE. IF THE CAP CAN BE WEAKENED...WILL HAVE TO WATCH CLOSELY FOR THE POTENTIAL OF SEVERE WEATHER ACROSS SOUTHERN WI/NORTHEAST IA WITH LARGE HAIL AND DAMAGING WIND BEING THE MAIN THREATS. OTHERWISE...VERY WARM AND STICKY CONDITIONS WILL BE SEEN AHEAD OF THE FRONT ACROSS SOUTHERN WI WITH TEMPERATURES EXPECTED TO TOP OFF IN THE LOW-MID 90S WITH DEW POINTS AROUND 70. THIS IS EXPECTED TO YIELD HEAT INDICES IN THE 100-105 DEGREE RANGE SOUTH OF A LINE FROM MAUSTON WI THROUGH PRAIRIE DU CHIEN. SINCE THERE IS ALREADY A HEAT ADVISORY HEADLINE OUT FOR PORTIONS OF THE AREA TIL 8 PM THIS EVENING...WILL LET THAT HEADLINE EXPIRE AND ASSESS WHAT AREA NEEDS TO BE IN AN ADVISORY FOR THURSDAY. PRELIMINARY INDICATIONS ARE THAT RICHLAND/CRAWFORD/GRANT COUNTIES WILL NEED AN ADVISORY. WILL CONTINUE TO ASSESS THIS EVENING AND HAVE NEW HEADLINE OUT BY 10 PM NEWS TIME. APPEARS THAT THIS FRONTAL BOUNDARY WILL REMAIN QUASI-STATIONARY THROUGH SATURDAY NIGHT AS FLOW ALOFT BECOMES PARALLEL TO IT. A COUPLE MID-LEVEL TROUGHS ARE EXPECTED TO INTERACT WITH THIS BOUNDARY FOR PERIODIC SHRA/TS CHANCES. LOOK FOR HIGHS ON FRIDAY IN THE UPPER 80S TO LOWER 90S AND IN THE MID 80S/FEW LOWER 90S ON SATURDAY. .LONG TERM...SUNDAY THROUGH WEDNESDAY 319 PM CDT WED JUN 27 2012 LATEST ECMWF/GFS SHOW A BUILDING RIDGE OVER THE AREA THROUGH THE PERIOD. SEVERAL WEAK MID-LEVEL TROUGH ROTATE OVER THE RIDGE SUNDAY THROUGH TUESDAY FOR A CHANCE OF SHOWERS AND THUNDERSTORMS. BY WEDNESDAY...MODELS SHOW THE RIDGE AMPLIFYING ACROSS THE PLAINS INTO THE UPPER MISSISSIPPI RIVER FOR DRY CONDITIONS. LOOKS LIKE HIGHS THROUGH THE PERIOD WILL CONTINUE TO BE ABOVE NORMAL WITH HIGHS TOPPING OFF IN THE MIDDLE 80S TO LOWER 90S. && .AVIATION... 600 PM CDT WED JUN 27 2012 COLD FRONT WILL SHIFT SOUTHEAST ACROSS THE REGION TONIGHT AND TOMORROW...LIKELY MOVING THROUGH KRST NEAR 08-09Z AND KLSE 10-11Z. MOISTURE POOLING AROUND THE BOUNDARY COULD RESULT IN SOME SUB VFR CIGS...WHICH SOME MODELS ARE SUGGESTING. SOME 2500-3000 CLOUDS NEAR THE BOUNDARY EVIDENCED BY LATEST SATELLITE IMAGERY AND SFC OBS...BUT TRENDS ARE DIMINISHING THIS AREA. WILL OPT TO STAY WITH SOME SCT035 TO ACCOUNT FOR THIS POTENTIAL. HIGHER MID LEVEL CLOUDS MORE LIKELY OVERNIGHT THROUGH THU MORNING. ALSO...THE HRRR POINTS TO SOME -SHRA POSSIBILITIES AS THE FRONT MOVES THROUGH THE TAF SITES. CHANCES ARE TOO SMALL TO INCLUDE IN THE TAFS AT THIS TIME. && .ARX WATCHES/WARNINGS/ADVISORIES... 319 PM CDT WED JUN 27 2012 WI...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR WIZ032-033-041. MN...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR MNZ079-086>088-094>096. IA...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR IAZ008>011-018-019-029-030. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION.....RIECK
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1106 AM CDT WED JUN 27 2012 .UPDATE... GUSTY SSW WINDS ARE USHERING HOT AIR INTO SOUTHERN WI ALREADY THIS MORNING. EXPECT MAX TEMPS TO STAY ON TRACK UP TO THE LOW/MID 90S BY LATE THIS AFTERNOON. DEEP MIXING OF DRY AIR WILL KEEP DEWPOINT TEMPS ON THE LOWER SIDE IN THE 50S...AND THEREFORE CAUSE LOW RELATIVE HUMIDITY IN THE 22 TO 30 PERCENT RANGE. MAX HEAT INDICES OF 90 TO 96 WILL REMAIN BELOW CRITERIA OF 100 FOR A HEAT ADVISORY. THAT WILL BE A DIFFERENT STORY FOR THURSDAY. A LONG AND NARROW PLUME OF MOISTURE EXTENDING FROM SOUTHEAST TEXAS UP THROUGH EASTERN NORTH DAKOTA...APPARENT BY SHADING THE DEWPOINT TEMPERATURES GREATER THAN 65 DEGREES...WILL SPREAD INTO SOUTHERN WISCONSIN AND ILLINOIS ON THURSDAY. DESPITE THE STRETCH OF DRY WEATHER AND LOWER DEWPOINT TEMPS...SOME OF THE HIGHER DEWPOINTS ARE EXPECTED TO POOL ALONG A FRONTAL BOUNDARY MOVING SOUTHEASTWARD ACROSS SOUTHERN WI DURING THE DAY ON THU. HOT TEMPERATURES IN THE MID/UPPER 90S AND DEWPOINT TEMPS 65 TO 71 WILL LEAD TO HEAT INDICES IN THE 100 TO 105 DEGREE RANGE AT TIMES BETWEEN NOON AND 8 PM ACROSS MUCH OF SOUTH CENTRAL AND SOUTHEAST WI ON THU. THEREFORE...ISSUED HEAT ADVISORY FOR THE WHOLE CWA DURING VALID FOR THAT TIME PERIOD. && .AVIATION/18Z TAFS/... VFR CONDITIONS THROUGH THE PERIOD. OTHER THAN SOME SCATTERED MID/HIGH LEVEL CLOUDS...GENERALLY CLEAR SKIES ARE EXPECTED. BREEZY SOUTH TO SOUTHWEST WINDS 13 TO 17KT WITH GUSTS TO 22 TO 25KT WILL PERSIST THROUGH THE LATE AFTERNOON. HIGHEST WIND GUSTS WILL BE IN THE WESTERN FORECAST AREA INCLUDING MADISON WHERE THE PRESSURE GRADIENT IS STRONGER. TEMPERATURES WILL BE VERY HOT IN THE LOW/MID 90S TODAY AND MID/UPPER 90S ON THURSDAY. WINDS WILL BE LIGHTER ON THU OUT OF THE WEST. WINDS WILL GRADUALLY DIMINISH AS THEY VEER TO THE NORTH THROUGH THE DAY. && .MARINE... INCREASING SOUTH WINDS ACROSS THE NEARSHORE WATERS AS THE SURFACE PRESSURE GRADIENT TIGHTENS AND A VERY WARM AIRMASS MOVES INTO THE REGION. WINDS MAY BECOME SOUTHEAST DURING THE AFTERNOON. WIND GUSTS WILL APPROACH SMALL CRAFT ADVISORY LEVELS. SUBSEQUENT WAVES SHOULD REMAIN BELOW CRITERIA. GIVEN THE BORDERLINE SCENARIO AND LAKE TEMPERATURES COOLER THAN THE LAND TEMPERATURES HAVING A STABILIZING EFFECT...DID NOT ISSUE A SMALL CRAFT ADVISORY HEADLINE. && .FIRE WEATHER... BREEZY SOUTH WINDS OF 15 TO 20 MPH WITH WIND GUSTS TO 27 MPH WILL BRING VERY WARM TEMPERATURES INTO THE MID 90S...WITH A FEW UPPER 90S WEST OF MADISON. DEEP LOW LEVEL MIXING OF DRY AIR WILL KEEP THE DEWPOINT TEMPERATURES RELATIVELY LOW IN THE LOW TO MID 50S...LEADING TO RELATIVE HUMIDITY VALUES IN THE 21 TO 28 PERCENT RANGE. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY. && .PREV DISCUSSION... /ISSUED 336 AM CDT WED JUN 27 2012/ TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH LARGE MID/UPPER LEVEL RIDGE EXTENDING FROM THE SOUTHERN PLAINS NORTHEAST INTO WISCONSIN TODAY. THE RIDGE OVER WISCONSIN BEGINS TO FLATTEN OUT LATE TONIGHT. STRONG 700 MB WARM AIR ADVECTION WITH 18 CELSIUS DEGREE TEMPERATURES REACHING SOUTH CENTRAL WISCONSIN THIS AFTERNOON. A 50 KNOT 850 KNOT WIND MAX MOVES FROM WESTERN IOWA WITH THE NOSE OF THE JET PUSHING INTO SOUTHWEST WISCONSIN THIS AFTERNOON. FAIRLY STRONG 850 MB MOISTURE CONVERGENCE. HOWEVER RH VALUES ARE STILL RATHER LOW...SO LITTLE POTENTIAL FOR CUMULUS TRAPPED UNDER THE STRONG CAP AROUND 7 THSD FT. WHILE THE 850 MB WIND MAX WEAKENS...THE VERY WARM 850MB TEMPERATURES RISE TO 29C JUST WEST OF THE MISSISSIPPI BY EARLY EVENING...BUT REMAIN AROUND 22C ACROSS SOUTH CENTRAL AND SOUTHEAST WISCONSIN UNTIL LATER TONIGHT WHEN THE 850 MB TEMPERATURES RISE TO 30 CELSIUS. AT THE SURFACE...HIGH PRESSURE OVER THE OHIO RIVER VALLEY WILL WEAKEN AS THE SOUTH TO SOUTHWEST FLOW INCREASES ACROSS SOUTHERN WISCONSIN. BREEZY WINDS 10 TO 20 MPH WITH GUSTS TO 25 MPH ARE EXPECTED THIS AFTERNOON. 925MB TEMPS RISE TO AROUND 28C ON THE NAM BY LATE AFTERNOON...YIELDING MAX TEMPS IN THE MID 90S. SOME UPPER 90S ARE POSSIBLE WEST AND SOUTH OF MADISON. DEEP LOW LEVEL MIXING OF DRY AIR WILL KEEP THE DEWPOINT TEMPERATURES RELATIVELY LOW TODAY...IN THE LOW TO MID 50S...LEADING TO RELATIVE HUMIDITY VALUES IN THE 25 TO 30 PERCENT RANGE. WITH THE GRASS AND OTHER VEGETATION BEING PRETTY DRY DUE TO THE LACK OF RECENT RAINFALL...CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED. DUE TO THE DRIER DEWPOINTS...NO HEAT ADVISORY CRITERIA IS EXPECTED TODAY. 925 MB TEMPERATURES WARM TO AROUND 32 CELSIUS BY MIDNIGHT...SO A VERY WARM NIGHT IS EXPECTED. THURSDAY...FORECAST CONFIDENCE...MEDIUM NOT MUCH HAS CHANGED FOR THURSDAY FORECAST. STILL LOOKS QUITE HOT...WITH HIGH TEMPS GENERALLY IN THE MID TO UPPER 90S...MAYBE 100 TOWARD ILLINOIS. AFTERNOON CLOUDS SOMEWHAT OF A CONCERN...WITH WEAK FRONTAL BOUNDARY IN THE AREA. NAM AND GFS BOTH SHOWING DECENT SATURATION AROUND 500 MB...SO GOOD CHANCE FOR DECK OF AT LEAST HIGHER LEVEL CLOUDS. THINKING THERE SHOULD BE ENOUGH BREAKS IN THE CLOUDS THOUGH FOR THE ANTICIPATED HOT TEMPS. WITH DEWPOINTS CREEPING UP TO AROUND 70...STILL THINKING HEAT INDEX VALUES WILL TOP OUT IN THE 100-105 RANGE. KEPT SLIGHT CHANCE POPS GOING FOR THE AFTERNOON. NOT TOO EXCITED ABOUT CHANCES THOUGH...AS MODELS GENERALLY A BIT STRONGER WITH CAP THAN THEY WERE A DAY AGO. STILL A TON OF CAPE IN SOUNDINGS...THOUGH PROBABLY A BIT OVERDONE WITH NAM/GFS DEWPOINTS TOO HIGH. A HEAT ADVISORY WILL PROBABLY BE NEEDED FOR THURSDAY IF THE FORECAST STAYS ON TRACK. WILL HOLD OFF ON ISSUING FOR NOW THOUGH DUE TO SOME CLOUD/PRECIP UNCERTAINTIES...ALONG WITH FRONT TIMING AND LOWERING 925 MB TEMPS FROM THE NW. FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM ABOVE NORMAL TEMPS WILL CONTINUE FOR FRIDAY AND THROUGH THE WEEKEND...THOUGH LIKELY NOT QUITE AS HOT AS THURSDAY. WENT WITH SLIGHT CHANCE POPS SOUTHWEST FRIDAY...AND THEN ACROSS THE FORECAST AREA SATURDAY AND SUNDAY. MODELS ADVERTISING A SERIES OF WEAK WAVES TO SLIDE THROUGH THE BAROCLINIC ZONE IN THE REGION...KICKING OFF SHOWERS/STORMS AT TIMES. NOT REAL CONFIDENT IN ANY ONE PERIOD FOR PRECIP...BUT AT LEAST SOMETHING TO HOPE FOR GIVEN VERY DRY CONDITIONS. MONDAY AND TUESDAY...FORECAST CONFIDENCE...LOW TO MEDIUM LOOKS DRY AND CONTINUED WARM MONDAY...WITH UPPER RIDGE AXIS OVER THE UPPER PLAINS. GFS DIGS A TROUGH IN FOR TUESDAY...WITH A RETURN OF SHOWER/STORM CHANCES. ECMWF ON THE OTHER HAND SLIDES THE RIDGE AXIS OVERHEAD WITH CONTINUED DRY AND EVEN WARMER CONDITIONS. WENT WITH MODEL CONSENSUS FOR NOW...SUGGESTING HIGHS REMAINING AROUND 90...ALONG WITH SOME LOW POPS. AVIATION/12Z TAFS/... VFR CONDITIONS THROUGH THE PERIOD. OTHER THAN SOME SCATTERED MID LEVEL CLOUDS...GENERALLY CLEAR SKIES ARE EXPECTED. CURRENT RAP MODEL FORECAST SOUNDINGS BRING WINDS UP TO 32 KNOTS AT 1 THSD FT BY SUNRISE AT MADISON...SO SOME WIND SHEAR POTENTIAL IS EXPECTED...BUT SHOULD BE MARGINAL. THE 1 THSD FT WINDS ARE WEAKER TO THE EAST THROUGH SUNRISE. SOUTH TO SOUTHWEST WINDS INCREASE THIS MORNING...WITH GUSTS TO 22 TO 25KT EXPECTED BY LATE MORNING AND PERSISTING THROUGH THE LATE AFTERNOON. HIGHEST WIND GUSTS WILL BE IN THE WESTERN FORECAST AREA INCLUDING MADISON. MARINE... SOUTH WINDS WILL INCREASE ACROSS THE NEARSHORE WATERS LATER THIS MORNING AS THE SURFACE PRESSURE GRADIENT TIGHTENS AND A VERY WARM AIRMASS MOVES INTO THE REGION. WINDS MAY BECOME SOUTHEAST DURING THE AFTERNOON. WIND GUSTS WILL APPROACH SMALL CRAFT ADVISORY LEVELS. SUBSEQUENT WAVES SHOULD REMAIN BELOW CRITERIA. GIVEN THE BORDERLINE SCENARIO AND LAKE TEMPERATURES COOLER THAN THE LAND TEMPERATURES HAVING A STABILIZING EFFECT...DID NOT ISSUE A SMALL CRAFT ADVISORY HEADLINE. FIRE WEATHER... BREEZY SOUTH WINDS OF 10 TO 20 MPH WITH WIND GUSTS TO 25 MPH WILL BRING VERY WARM TEMPERATURES INTO THE MID 90S...WITH A FEW UPPER 90S WEST OF MADISON. DEEP LOW LEVEL MIXING OF DRY AIR WILL KEEP THE DEWPOINT TEMPERATURES RELATIVELY LOW IN THE LOW TO MID 50S...LEADING TO RELATIVE HUMIDITY VALUES IN THE 21 TO 28 PERCENT RANGE. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY...WITH THE GRASS AND OTHER VEGETATION BEING DRY DUE TO THE LACK OF RECENT RAINFALL. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...HEAT ADVISORY FROM NOON TO 8 PM CDT THURSDAY FOR WIZ046-047-051- 052-056>060-062>072. LM...NONE. && $$ UPDATE...MRC TODAY/TONIGHT AND AVIATION/MARINE...HENTZ THURSDAY THROUGH TUESDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
357 AM CDT WED JUN 27 2012 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT 357 AM CDT WED JUN 27 2012 MAIN FORECAST CONCERNS ARE ON OPPRESSIVE HEAT TODAY INTO THURSDAY. FOCUS THEN TURNS TO SHOWER/THUNDERSTORM CHANCES THURSDAY INTO THE WEEKEND. LATEST SURFACE OBSERVATIONS SHOWED HIGH PRESSURE CENTERED NEAR THE OHIO RIVER VALLEY WITH A SURFACE TROUGH OVER THE CENTRAL DAKOTAS...EXTENDING SOUTH THROUGH EASTERN COLORADO. THE UPPER MISSISSIPPI RIVER VALLEY WAS BETWEEN THESE TWO FEATURES...PLACING THE REGION IN A TIGHT PRESSURE GRADIENT PRODUCING WARM SOUTHERLY FLOW AT THE SURFACE. WATER VAPOR IMAGERY SHOWED AN UPPER RIDGE ANCHORED OVER THE CENTRAL PLAINS...EXTENDING NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY INTO CENTRAL ONTARIO. A HOT AND BREEZY DAY IS EXPECTED ACROSS THE FORECAST AREA TODAY AS THE UPPER RIDGE MOVES OVER THE REGION. MUGGY AIR WILL MAKE ITS WAY EASTWARD ACROSS MINNESOTA...PUSHING INTO THE FORECAST AREA THIS AFTERNOON. BY THIS AFTERNOON...DEW POINTS ACROSS MUCH OF NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND PORTIONS OF SOUTHWEST INTO WEST CENTRAL WISCONSIN WILL CLIMB INTO THE UPPER 60S TO AROUND 70. DRIER AIR IS EXPECTED TO REMAIN IN PLACE ACROSS PORTIONS OF FAR NORTHEAST IOWA...SOUTHWEST INTO CENTRAL WISCONSIN WITH DEW POINTS ONLY IN THE 50S. THESE LOW DEW POINTS WILL PRODUCE EARLY AFTERNOON RELATIVE HUMIDITY VALUES IN THE UPPER 20S TO LOWER 30S ACROSS THESE AREAS. PLAN ON SOUTH/SOUTHWEST WINDS TODAY AT 10 TO 20 MPH...WITH GUSTS AROUND 30 MPH POSSIBLE. THESE LOWER RH VALUES AND BREEZY WINDS COULD CREATE FIRE WEATHER CONCERNS...SEE FIRE WEATHER DISCUSSION BELOW. 850 MB TEMPERATURES WILL CLIMB THROUGH THE DAY TODAY...RANGING FROM 23 C ACROSS CENTRAL WISCONSIN TO 26 C ACROSS WESTERN PORTIONS OF SOUTHEAST MINNESOTA INTO NORTHEAST IOWA BY MID AFTERNOON. TEMPERATURES ARE EXPECTED TO SOAR INTO THE 90S ACROSS MUCH OF THE FORECAST AREA...WITH MID TO UPPER 90S EXPECTED ALONG AND WEST OF THE MISSISSIPPI RIVER. HEAT INDEX VALUES ARE EXPECTED TO REACH INTO THE 100 TO 105 DEGREE RANGE THIS AFTERNOON ACROSS THESE AREAS...SO WILL CONTINUE THE HEAT ADVISORY TODAY FROM 1 PM TO 8 PM. A VERY WARM AND MUGGY NIGHT WILL BE FOUND ACROSS THE AREA TONIGHT. THE WARMEST AIR ALOFT WILL SETTLE OVER THE REGION THIS EVENING WITH 850 MB TEMPERATURES RANGING FROM 25 C OVER CENTRAL WISCONSIN TO 31 C OVER NORTHEAST IOWA. A WEAK SURFACE TROUGH IS EXPECTED TO MOVE INTO THE AREA TONIGHT AND WILL SLACKEN THE GRADIENT ESPECIALLY FOR LOCATIONS ALONG AND NORTH OF INTERSTATE 90. THIS SHOULD ALLOW SOME DECOUPLING AT THE SURFACE...ESPECIALLY ALONG RIVER VALLEYS AND FAVORED LOW LYING AREAS. THE NAM AND ECMWF ARE IN EXCELLENT AGREEMENT BRINGING THIS WEAK LOW OVER THE AREA SO HAVE DECIDED TO LOWER OVERNIGHT LOWS IN THE FAVORED DECOUPLING AREAS OVER SOUTHEAST MINNESOTA AND SOUTHWEST INTO CENTRAL WISCONSIN. WITH THE HIGHER DEW POINTS IN PLACE WILL HAVE TO KEEP A WATCH OUT FOR SHALLOW FOG DEVELOPMENT. PLAN ON OVERNIGHT LOWS RANGING FROM THE UPPER 60S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER 70S OVER NORTHEAST IOWA. THE SURFACE LOW WILL PUSH A WEAK COLD FRONT THROUGH THE FORECAST AREA LATE TONIGHT INTO EARLY THURSDAY MORNING. SLIGHTLY COOLER AIR WILL MOVE INTO THE AREA THROUGH DAY ON THURSDAY THIS SHOULD HELP TO MITIGATE HEAT CONCERNS. HOWEVER...HIGHS ACROSS PORTIONS OF NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN WILL SEE HIGHS CLIMB INTO THE MID 90S. DEW POINTS ARE EXPECTED TO GRADUALLY FALL THROUGH THE DAY IN THE WAKE OF THE FRONT. HEAT INDEX VALUES COULD CLIMB TO AROUND 100 ONCE AGAIN ON THURSDAY OVER PORTIONS OF NORTHEAST IOWA THROUGH CENTRAL WISCONSIN. WILL HAVE TO KEEP A CLOSE WATCH ON THE TIMING OF THE COLD FRONT AND HOW QUICKLY THE DRIER AIR ARRIVES. STRONG INSTABILITY DEVELOPS...MUCAPE OF 3000-5000 J/KG AHEAD OF THE FRONT TUESDAY AFTERNOON SOUTH OF INTERSTATE 90. FORECAST SOUNDINGS SHOW A STRONG CAP IN PLACE...WITH SBCIN VALUES OF NEGATIVE 200-300 J/KG. IF THE CAP CAN BE BROKEN...0-6 KM SHEAR VALUES OF 30 TO 45 KTS. IT APPEARS THAT CONVECTION WOULD FIRE JUST SOUTH OF THE FORECAST AREA DURING THE LATE AFTERNOON HOURS. IF STORMS DEVELOP THURSDAY AFTERNOON THEY WOULD BE CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. 850 MB TEMPERATURES FALL TO 22 C BEHIND THE BOUNDARY THURSDAY AFTERNOON INTO THURSDAY EVENING. A BAROCLINIC ZONE WILL SET UP OVER NORTHERN IOWA THROUGH FAR SOUTHERN WISCONSIN AND NORTHERN IOWA THURSDAY NIGHT THROUGH FRIDAY NIGHT AND WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM CHANCES. FLOW ALOFT WILL TURN ZONAL THURSDAY NIGHT WITH SEVERAL WEAK EMBEDDED SHORTWAVES MOVING OVER THE REGION AND INTERACTING THE BOUNDARY. 0-3 KM MUCAPE VALUES WILL HOVER AROUND 3000 J/KG AND 0-6KM 30 KTS WOULD BE FAVORABLE FOR STRONG TO SEVERE STORMS...BUT THERE WILL BE A STRONG CAP IN PLACE WITH THE WARM AIR ALOFT SO IT WILL BE TOUGH TO INITIATE CONVECTION. WILL HAVE TO KEEP A CLOSE WATCH ON THE CAP THE FEW MODEL RUNS. .LONG TERM...TODAY THROUGH THURSDAY 357 AM CDT WED JUN 27 2012 THE COMBINATION OF A VERY HOT AND DRY AIR MASS WILL LEAD TO AN ELEVATED FIRE DANGER FOR PARTS OF SOUTHERN WISCONSIN...MAINLY ALONG AND SOUTH OF A MAUSTON TO PRAIRIE DU CHIEN LINE. MINIMUM RELATIVE HUMIDITIES IN THIS AREA WILL DROP TO AROUND 30 PERCENT. HIGHS TODAY WILL RANGE FROM NEAR 90 ACROSS NORTH CENTRAL WISCONSIN...TO THE MID AND UPPER 90S ACROSS THE REST OF THE AREA. IT WILL ALSO BE QUITE BREEZY...WITH SOUTHERLY AROUND 15 MPH...AND GUSTS UP TO 30 MPH EXPECTED. HEAT INDEX VALUES WILL CLIMB INTO THE 100-105 DEGREE RANGE ALONG AND WEST OF THE MISSISSIPPI RIVER. ON THURSDAY...ANOTHER HOT AND DRY DAY IS EXPECTED...ALTHOUGH HIGHS WILL BE A FEW DEGREES COOLER AND DEW POINTS A BIT HIGHER AS WELL...WHICH WILL PRODUCE MINIMUM RH VALUES IN THE MID TO UPPER 40S. A COLD FRONT WILL SWEEP THROUGH DURING THE AFTERNOON...AND BRING A VERY SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WITH LOW CONFIDENCE ON WIDESPREAD WETTING RAINS. LOOKING AHEAD...WARM CONDITIONS WILL PERSIST FRIDAY AND THROUGH THE WEEKEND. A FRONTAL BOUNDARY WILL SETTLE SOUTH OF THE AREA SATURDAY...AND THIS WILL PRODUCE SMALL CHANCES OF SHOWERS/THUNDERSTORMS. && .AVIATION...THROUGH 06Z THURSDAY 1152 PM CDT TUE JUN 26 2012 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH CLEAR SKIES TONIGHT AND SOME SCATTERED TO BROKEN CIRRUS AFTER 21Z WEDNESDAY. LOW LEVEL JET DOES INCREASE OVERNIGHT...BUT 27.02Z RAP NOW SHOWS 35 TO 40 KNOT WINDS AT 2K FEET BETWEEN 09Z-12Z. WITH SURFACE WINDS STAYING UP DUE TO THE GRADIENT WILL NOT BE MENTIONING ANY LLWS. && .FIRE WEATHER...TODAY AND THURSDAY 357 AM CDT WED JUN 27 2012 THE COMBINATION OF A VERY HOT AND DRY AIR MASS WILL LEAD TO AN ELEVATED FIRE DANGER FOR PARTS OF SOUTHERN WISCONSIN...MAINLY ALONG AND SOUTH OF A MAUSTON TO PRAIRIE DU CHIEN LINE. MINIMUM RELATIVE HUMIDITIES IN THIS AREA WILL DROP TO AROUND 30 PERCENT. HIGHS TODAY WILL RANGE FROM NEAR 90 ACROSS NORTH CENTRAL WISCONSIN...TO THE MID AND UPPER 90S ACROSS THE REST OF THE AREA. IT WILL ALSO BE QUITE BREEZY...WITH SOUTHERLY AROUND 15 MPH...AND GUSTS UP TO 30 MPH EXPECTED. HEAT INDEX VALUES WILL CLIMB INTO THE 100-105 DEGREE RANGE ALONG AND WEST OF THE MISSISSIPPI RIVER. ON THURSDAY...ANOTHER HOT AND DRY DAY IS EXPECTED...ALTHOUGH HIGHS WILL BE A FEW DEGREES COOLER AND DEW POINTS A BIT HIGHER AS WELL...WHICH WILL PRODUCE MINIMUM RH VALUES IN THE MID TO UPPER 40S. A COLD FRONT WILL SWEEP THROUGH DURING THE AFTERNOON...AND BRING A VERY SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WITH LOW CONFIDENCE ON WIDESPREAD WETTING RAINS. LOOKING AHEAD...WARM CONDITIONS WILL PERSIST FRIDAY AND THROUGH THE WEEKEND. A FRONTAL BOUNDARY WILL SETTLE SOUTH OF THE AREA SATURDAY...AND THIS WILL PRODUCE SMALL CHANCES OF SHOWERS/THUNDERSTORMS. && .ARX WATCHES/WARNINGS/ADVISORIES... 357 AM CDT WED JUN 27 2012 WI...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR WIZ032-033-041. MN...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR MNZ079-086>088-094>096. IA...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR IAZ008>011-018-019-029-030. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...RABERDING FIRE WEATHER...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 AM CDT WED JUN 27 2012 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT 346 AM CDT WED JUN 27 2012 MAIN FORECAST CONCERNS ARE ON OPPRESSIVE HEAT TODAY INTO THURSDAY. FOCUS THEN TURNS TO SHOWER/THUNDERSTORM CHANCES THURSDAY INTO THE WEEKEND. LATEST SURFACE OBSERVATIONS SHOWED HIGH PRESSURE CENTERED NEAR THE OHIO RIVER VALLEY WITH A SURFACE TROUGH OVER THE CENTRAL DAKOTAS...EXTENDING SOUTH THROUGH EASTERN COLORADO. THE UPPER MISSISSIPPI RIVER VALLEY WAS BETWEEN THESE TWO FEATURES...PLACING THE REGION IN A TIGHT PRESSURE GRADIENT PRODUCING WARM SOUTHERLY FLOW AT THE SURFACE. WATER VAPOR IMAGERY SHOWED AN UPPER RIDGE ANCHORED OVER THE CENTRAL PLAINS...EXTENDING NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY INTO CENTRAL ONTARIO. A HOT AND BREEZY DAY IS EXPECTED ACROSS THE FORECAST AREA TODAY AS THE UPPER RIDGE MOVES OVER THE REGION. MUGGY AIR WILL MAKE ITS WAY EASTWARD ACROSS MINNESOTA...PUSHING INTO THE FORECAST AREA THIS AFTERNOON. BY THIS AFTERNOON...DEW POINTS ACROSS MUCH OF NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND PORTIONS OF SOUTHWEST INTO WEST CENTRAL WISCONSIN WILL CLIMB INTO THE UPPER 60S TO AROUND 70. DRIER AIR IS EXPECTED TO REMAIN IN PLACE ACROSS PORTIONS OF FAR NORTHEAST IOWA...SOUTHWEST INTO CENTRAL WISCONSIN WITH DEW POINTS ONLY IN THE 50S. THESE LOW DEW POINTS WILL PRODUCE EARLY AFTERNOON RELATIVE HUMIDITY VALUES IN THE UPPER 20S TO LOWER 30S ACROSS THESE AREAS. PLAN ON SOUTH/SOUTHWEST WINDS TODAY AT 10 TO 20 MPH...WITH GUSTS AROUND 30 MPH POSSIBLE. THESE LOWER RH VALUES AND BREEZY WINDS COULD CREATE FIRE WEATHER CONCERNS...SEE FIRE WEATHER DISCUSSION BELOW. 850 MB TEMPERATURES WILL CLIMB THROUGH THE DAY TODAY...RANGING FROM 23 C ACROSS CENTRAL WISCONSIN TO 26 C ACROSS WESTERN PORTIONS OF SOUTHEAST MINNESOTA INTO NORTHEAST IOWA BY MID AFTERNOON. TEMPERATURES ARE EXPECTED TO SOAR INTO THE 90S ACROSS MUCH OF THE FORECAST AREA...WITH MID TO UPPER 90S EXPECTED ALONG AND WEST OF THE MISSISSIPPI RIVER. HEAT INDEX VALUES ARE EXPECTED TO REACH INTO THE 100 TO 105 DEGREE RANGE THIS AFTERNOON ACROSS THESE AREAS...SO WILL CONTINUE THE HEAT ADVISORY TODAY FROM 1 PM TO 8 PM. A VERY WARM AND MUGGY NIGHT WILL BE FOUND ACROSS THE AREA TONIGHT. THE WARMEST AIR ALOFT WILL SETTLE OVER THE REGION THIS EVENING WITH 850 MB TEMPERATURES RANGING FROM 25 C OVER CENTRAL WISCONSIN TO 31 C OVER NORTHEAST IOWA. A WEAK SURFACE TROUGH IS EXPECTED TO MOVE INTO THE AREA TONIGHT AND WILL SLACKEN THE GRADIENT ESPECIALLY FOR LOCATIONS ALONG AND NORTH OF INTERSTATE 90. THIS SHOULD ALLOW SOME DECOUPLING AT THE SURFACE...ESPECIALLY ALONG RIVER VALLEYS AND FAVORED LOW LYING AREAS. THE NAM AND ECMWF ARE IN EXCELLENT AGREEMENT BRINGING THIS WEAK LOW OVER THE AREA SO HAVE DECIDED TO LOWER OVERNIGHT LOWS IN THE FAVORED DECOUPLING AREAS OVER SOUTHEAST MINNESOTA AND SOUTHWEST INTO CENTRAL WISCONSIN. WITH THE HIGHER DEW POINTS IN PLACE WILL HAVE TO KEEP A WATCH OUT FOR SHALLOW FOG DEVELOPMENT. PLAN ON OVERNIGHT LOWS RANGING FROM THE UPPER 60S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER 70S OVER NORTHEAST IOWA. THE SURFACE LOW WILL PUSH A WEAK COLD FRONT THROUGH THE FORECAST AREA LATE TONIGHT INTO EARLY THURSDAY MORNING. SLIGHTLY COOLER AIR WILL MOVE INTO THE AREA THROUGH DAY ON THURSDAY THIS SHOULD HELP TO MITIGATE HEAT CONCERNS. HOWEVER...HIGHS ACROSS PORTIONS OF NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN WILL SEE HIGHS CLIMB INTO THE MID 90S. DEW POINTS ARE EXPECTED TO GRADUALLY FALL THROUGH THE DAY IN THE WAKE OF THE FRONT. HEAT INDEX VALUES COULD CLIMB TO AROUND 100 ONCE AGAIN ON THURSDAY OVER PORTIONS OF NORTHEAST IOWA THROUGH CENTRAL WISCONSIN. WILL HAVE TO KEEP A CLOSE WATCH ON THE TIMING OF THE COLD FRONT AND HOW QUICKLY THE DRIER AIR ARRIVES. STRONG INSTABILITY DEVELOPS...MUCAPE OF 3000-5000 J/KG AHEAD OF THE FRONT TUESDAY AFTERNOON SOUTH OF INTERSTATE 90. FORECAST SOUNDINGS SHOW A STRONG CAP IN PLACE...WITH SBCIN VALUES OF NEGATIVE 200-300 J/KG. IF THE CAP CAN BE BROKEN...0-6 KM SHEAR VALUES OF 30 TO 45 KTS. IT APPEARS THAT CONVECTION WOULD FIRE JUST SOUTH OF THE FORECAST AREA DURING THE LATE AFTERNOON HOURS. IF STORMS DEVELOP THURSDAY AFTERNOON THEY WOULD BE CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. 850 MB TEMPERATURES FALL TO 22 C BEHIND THE BOUNDARY THURSDAY AFTERNOON INTO THURSDAY EVENING. A BAROCLINIC ZONE WILL SET UP OVER NORTHERN IOWA THROUGH FAR SOUTHERN WISCONSIN AND NORTHERN IOWA THURSDAY NIGHT THROUGH FRIDAY NIGHT AND WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM CHANCES. FLOW ALOFT WILL TURN ZONAL THURSDAY NIGHT WITH SEVERAL WEAK EMBEDDED SHORTWAVES MOVING OVER THE REGION AND INTERACTING THE BOUNDARY. 0-3 KM MUCAPE VALUES WILL HOVER AROUND 3000 J/KG AND 0-6KM 30 KTS WOULD BE FAVORABLE FOR STRONG TO SEVERE STORMS...BUT THERE WILL BE A STRONG CAP IN PLACE WITH THE WARM AIR ALOFT SO IT WILL BE TOUGH TO INITIATE CONVECTION. WILL HAVE TO KEEP A CLOSE WATCH ON THE CAP THE FEW MODEL RUNS. .LONG TERM...SATURDAY THROUGH TUESDAY 346 AM CDT WED JUN 27 2012 27.00 FORECAST MODELS SHOW THE BAROCLINIC ZONE SLOWLY LIFTING NORTHWARD INTO THE FORECAST AREA SATURDAY INTO SATURDAY NIGHT. THE FIRST TO TWO SHORTWAVES LOOKS TO PUSH ACROSS THE FORECAST AREA DURING THE DAY ON SATURDAY...WITH THE SECOND WAVE MOVING OVER THE REGION SATURDAY NIGHT. THESE TWO WAVES WILL INTERACT WITH THE BOUNDARY BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA. WARM TEMPERATURES WILL PERSIST THROUGH THE WEEKEND WITH HIGHS RANGING FROM THE LOWER 80S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER 80S OVER NORTHEAST IOWA. UPPER RIDGING IS EXPECTED TO BUILD INTO THE UPPER MISSISSIPPI RIVER VALLEY MONDAY INTO TUESDAY WITH WARM AIR REMAINING IN PLACE. THE ECMWF IS THE MOST ROBUST WITH THE RIDGE...WARMING TEMPERATURES BACK INTO THE UPPER 90S TO AROUND 100. THE GFS FLATTENS THE RIDGE MONDAY NIGHT INTO TUESDAY WITH CONVECTION FIRE OVER THE NORTHERN PLAINS. WILL HAVE TO KEEP A CLOSE WATCH ON THE NEXT SET OF MODEL RUNS...WITH THE POTENTIAL TO WARM HIGHS SIGNIFICANTLY MONDAY INTO TUESDAY IF THE ECMWF SOLUTION HOLDS. WILL MAINTAIN LOW CHANCES FOR SHOWERS AND THUNDERSTORMS MONDAY INTO TUESDAY WITH THE POTENTIAL TO SEE A FEW WEAK SHORTWAVE ROTATE THROUGH THE RIDGE AND MOVE OVER THE REGION. && .AVIATION...THROUGH 06Z THURSDAY 1152 PM CDT TUE JUN 26 2012 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH CLEAR SKIES TONIGHT AND SOME SCATTERED TO BROKEN CIRRUS AFTER 21Z WEDNESDAY. LOW LEVEL JET DOES INCREASE OVERNIGHT...BUT 27.02Z RAP NOW SHOWS 35 TO 40 KNOT WINDS AT 2K FEET BETWEEN 09Z-12Z. WITH SURFACE WINDS STAYING UP DUE TO THE GRADIENT WILL NOT BE MENTIONING ANY LLWS. && .FIRE WEATHER...TODAY AND THURSDAY 346 PM CDT TUE JUN 26 2012 THE COMBINATION OF A VERY HOT AND DRY AIR MASS WILL LEAD TO AN ELEVATED FIRE DANGER FOR PARTS OF SOUTHERN WISCONSIN...MAINLY ALONG AND SOUTH OF A MAUSTON TO PRAIRIE DU CHIEN LINE. MINIMUM RELATIVE HUMIDITIES IN THIS AREA WILL DROP TO AROUND 30 PERCENT. HIGHS TODAY WILL RANGE FROM NEAR 90 ACROSS NORTH CENTRAL WISCONSIN...TO THE MID AND UPPER 90S ACROSS THE REST OF THE AREA. IT WILL ALSO BE QUITE BREEZY...WITH SOUTHERLY AROUND 15 MPH...AND GUSTS UP TO 30 MPH EXPECTED. HEAT INDEX VALUES WILL CLIMB INTO THE 100-105 DEGREE RANGE ALONG AND WEST OF THE MISSISSIPPI RIVER. ON THURSDAY...ANOTHER HOT AND DRY DAY IS EXPECTED...ALTHOUGH HIGHS WILL BE A FEW DEGREES COOLER AND DEW POINTS A BIT HIGHER AS WELL...WHICH WILL PRODUCE MINIMUM RH VALUES IN THE MID TO UPPER 40S. A COLD FRONT WILL SWEEP THROUGH DURING THE AFTERNOON...AND BRING A VERY SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WITH LOW CONFIDENCE ON WIDESPREAD WETTING RAINS. LOOKING AHEAD...WARM CONDITIONS WILL PERSIST FRIDAY AND THROUGH THE WEEKEND. A FRONTAL BOUNDARY WILL SETTLE SOUTH OF THE AREA SATURDAY...AND THIS WILL PRODUCE SMALL CHANCES OF SHOWERS/THUNDERSTORMS. && .ARX WATCHES/WARNINGS/ADVISORIES... 346 AM CDT WED JUN 27 2012 WI...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR WIZ032-033-041. MN...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR MNZ079-086>088-094>096. IA...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR IAZ008>011-018-019-029-030. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...RABERDING FIRE WEATHER...ZT
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
336 AM CDT WED JUN 27 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH LARGE MID/UPPER LEVEL RIDGE EXTENDING FROM THE SOUTHERN PLAINS NORTHEAST INTO WISCONSIN TODAY. THE RIDGE OVER WISCONSIN BEGINS TO FLATTEN OUT LATE TONIGHT. STRONG 700 MB WARM AIR ADVECTION WITH 18 CELSIUS DEGREE TEMPERATURES REACHING SOUTH CENTRAL WISCONSIN THIS AFTERNOON. A 50 KNOT 850 KNOT WIND MAX MOVES FROM WESTERN IOWA WITH THE NOSE OF THE JET PUSHING INTO SOUTHWEST WISCONSIN THIS AFTERNOON. FAIRLY STRONG 850 MB MOISTURE CONVERGENCE. HOWEVER RH VALUES ARE STILL RATHER LOW...SO LITTLE POTENTIAL FOR CUMULUS TRAPPED UNDER THE STRONG CAP AROUND 7 THSD FT. WHILE THE 850 MB WIND MAX WEAKENS...THE VERY WARM 850MB TEMPERATURES RISE TO 29C JUST WEST OF THE MISSISSIPPI BY EARLY EVENING...BUT REMAIN AROUND 22C ACROSS SOUTH CENTRAL AND SOUTHEAST WISCONSIN UNTIL LATER TONIGHT WHEN THE 850 MB TEMPERATURES RISE TO 30 CELSIUS. AT THE SURFACE...HIGH PRESSURE OVER THE OHIO RIVER VALLEY WILL WEAKEN AS THE SOUTH TO SOUTHWEST FLOW INCREASES ACROSS SOUTHERN WISCONSIN. BREEZY WINDS 10 TO 20 MPH WITH GUSTS TO 25 MPH ARE EXPECTED THIS AFTERNOON. 925MB TEMPS RISE TO AROUND 28C ON THE NAM BY LATE AFTERNOON...YIELDING MAX TEMPS IN THE MID 90S. SOME UPPER 90S ARE POSSIBLE WEST AND SOUTH OF MADISON. DEEP LOW LEVEL MIXING OF DRY AIR WILL KEEP THE DEWPOINT TEMPERATURES RELATIVELY LOW TODAY...IN THE LOW TO MID 50S...LEADING TO RELATIVE HUMIDITY VALUES IN THE 25 TO 30 PERCENT RANGE. WITH THE GRASS AND OTHER VEGETATION BEING PRETTY DRY DUE TO THE LACK OF RECENT RAINFALL...CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED. DUE TO THE DRIER DEWPOINTS...NO HEAT ADVISORY CRITERIA IS EXPECTED TODAY. 925 MB TEMPERATURES WARM TO AROUND 32 CELSIUS BY MIDNIGHT...SO A VERY WARM NIGHT IS EXPECTED. .THURSDAY...FORECAST CONFIDENCE...MEDIUM NOT MUCH HAS CHANGED FOR THURSDAY FORECAST. STILL LOOKS QUITE HOT...WITH HIGH TEMPS GENERALLY IN THE MID TO UPPER 90S...MAYBE 100 TOWARD ILLINOIS. AFTERNOON CLOUDS SOMEWHAT OF A CONCERN...WITH WEAK FRONTAL BOUNDARY IN THE AREA. NAM AND GFS BOTH SHOWING DECENT SATURATION AROUND 500 MB...SO GOOD CHANCE FOR DECK OF AT LEAST HIGHER LEVEL CLOUDS. THINKING THERE SHOULD BE ENOUGH BREAKS IN THE CLOUDS THOUGH FOR THE ANTICIPATED HOT TEMPS. WITH DEWPOINTS CREEPING UP TO AROUND 70...STILL THINKING HEAT INDEX VALUES WILL TOP OUT IN THE 100-105 RANGE. KEPT SLIGHT CHANCE POPS GOING FOR THE AFTERNOON. NOT TOO EXCITED ABOUT CHANCES THOUGH...AS MODELS GENERALLY A BIT STRONGER WITH CAP THAN THEY WERE A DAY AGO. STILL A TON OF CAPE IN SOUNDINGS...THOUGH PROBABLY A BIT OVERDONE WITH NAM/GFS DEWPOINTS TOO HIGH. A HEAT ADVISORY WILL PROBABLY BE NEEDED FOR THURSDAY IF THE FORECAST STAYS ON TRACK. WILL HOLD OFF ON ISSUING FOR NOW THOUGH DUE TO SOME CLOUD/PRECIP UNCERTAINTIES...ALONG WITH FRONT TIMING AND LOWERING 925 MB TEMPS FROM THE NW. .FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM ABOVE NORMAL TEMPS WILL CONTINUE FOR FRIDAY AND THROUGH THE WEEKEND...THOUGH LIKELY NOT QUITE AS HOT AS THURSDAY. WENT WITH SLIGHT CHANCE POPS SOUTHWEST FRIDAY...AND THEN ACROSS THE FORECAST AREA SATURDAY AND SUNDAY. MODELS ADVERTISING A SERIES OF WEAK WAVES TO SLIDE THROUGH THE BAROCLINIC ZONE IN THE REGION...KICKING OFF SHOWERS/STORMS AT TIMES. NOT REAL CONFIDENT IN ANY ONE PERIOD FOR PRECIP...BUT AT LEAST SOMETHING TO HOPE FOR GIVEN VERY DRY CONDITIONS. .MONDAY AND TUESDAY...FORECAST CONFIDENCE...LOW TO MEDIUM LOOKS DRY AND CONTINUED WARM MONDAY...WITH UPPER RIDGE AXIS OVER THE UPPER PLAINS. GFS DIGS A TROUGH IN FOR TUESDAY...WITH A RETURN OF SHOWER/STORM CHANCES. ECMWF ON THE OTHER HAND SLIDES THE RIDGE AXIS OVERHEAD WITH CONTINUED DRY AND EVEN WARMER CONDITIONS. WENT WITH MODEL CONSENSUS FOR NOW...SUGGESTING HIGHS REMAINING AROUND 90...ALONG WITH SOME LOW POPS. && .AVIATION/12Z TAFS/... VFR CONDITIONS THROUGH THE PERIOD. OTHER THAN SOME SCATTERED MID LEVEL CLOUDS...GENERALLY CLEAR SKIES ARE EXPECTED. CURRENT RAP MODEL FORECAST SOUNDINGS BRING WINDS UP TO 32 KNOTS AT 1 THSD FT BY SUNRISE AT MADISON...SO SOME WIND SHEAR POTENTIAL IS EXPECTED...BUT SHOULD BE MARGINAL. THE 1 THSD FT WINDS ARE WEAKER TO THE EAST THROUGH SUNRISE. SOUTH TO SOUTHWEST WINDS INCREASE THIS MORNING...WITH GUSTS TO 22 TO 25KT EXPECTED BY LATE MORNING AND PERSISTING THROUGH THE LATE AFTERNOON. HIGHEST WIND GUSTS WILL BE IN THE WESTERN FORECAST AREA INCLUDING MADISON. && .MARINE... SOUTH WINDS WILL INCREASE ACROSS THE NEARSHORE WATERS LATER THIS MORNING AS THE SURFACE PRESSURE GRADIENT TIGHTENS AND A VERY WARM AIRMASS MOVES INTO THE REGION. WINDS MAY BECOME SOUTHEAST DURING THE AFTERNOON. WIND GUSTS WILL APPROACH SMALL CRAFT ADVISORY LEVELS. SUBSEQUENT WAVES SHOULD REMAIN BELOW CRITERIA. GIVEN THE BORDERLINE SCENARIO AND LAKE TEMPERATURES COOLER THAN THE LAND TEMPERATURES HAVING A STABILIZING EFFECT...DID NOT ISSUE A SMALL CRAFT ADVISORY HEADLINE. && .FIRE WEATHER... BREEZY SOUTH WINDS OF 10 TO 20 MPH WITH WIND GUSTS TO 25 MPH WILL BRING VERY WARM TEMPERATURES INTO THE MID 90S...WITH A FEW UPPER 90S WEST OF MADISON. DEEP LOW LEVEL MIXING OF DRY AIR WILL KEEP THE DEWPOINT TEMPERATURES RELATIVELY LOW IN THE LOW TO MID 50S...LEADING TO RELATIVE HUMIDITY VALUES IN THE 21 TO 28 PERCENT RANGE. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY...WITH THE GRASS AND OTHER VEGETATION BEING DRY DUE TO THE LACK OF RECENT RAINFALL. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE/FIRE WEATHER...HENTZ THURSDAY THROUGH TUESDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1152 PM CDT TUE JUN 26 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT 325 PM CDT TUE JUN 26 2012 MAIN FORECAST CONCERNS THIS PACKAGE...HEAT/HUMIDITY WED/THU...SMALL SHRA/TSRA CHANCES THU/THU NIGHT. 18Z DATA ANALYSIS HAD HIGH PRESSURE CENTERED OVER LAKE MI AND LOW PRESSURE OVER EASTERN MN. PRESSURE GRADIENT WAS TIGHTER OVER MUCH OF MN/IA/WI BETWEEN THE TWO WITH SOUTHEAST WINDS OF 15-25MPH COMMON ACROSS MN/IA AND 5 TO 15 MPH ACROSS WI. WEAK SHORTWAVE RIPPLING THRU THE FLOW WAS SPREADING SOME AC AND CIRRUS ACROSS THE REGION. SFC DEW POINTS REMAINED IN THE 50S OVER WI/MN AND MOST OF IA...FOR ANOTHER RATHER COMFORTABLE LATE JUNE DAY WITH TEMPS IN THE 70S TO AROUND 80. MOISTURE PLUME WITH SFC DEW POINTS IN THE 60S TO LOWER 70S REMAINED OVER THE DAKOTAS TO EASTERN KS/WESTERN MO. NO MAJOR ISSUES NOTED WITH 26.12Z MODEL INITIALIZATIONS...OTHER THAN THE GFS/S ROUGHLY 5F HIGH BIAS WITH SFC DEW POINTS IN THE PLAINS MOISTURE PLUME. SOLUTIONS QUITE SIMILAR FOR TONIGHT INTO FRI NIGHT...BUT FOR GFS AND ITS HIGH MOISTURE BIAS IN THE LOWER LEVEL AND GREATER PRODUCTION OF PRECIP STARTING LATE WED NIGHT. DPROG/DT OF 500MB HGTS AT 26.12Z SHOWED THE MODEL RUNS OF 24.12Z AND 25.12Z VERIFIED WELL ACROSS NOAM/EASTERN PAC. TREND TONIGHT/WED IS A TIGHTER CONSENSUS FAVORING MORE PROGRESSIVE OF EARLIER RUNS WITH FEATURES ACROSS NOAM. THIS TREND CONTINUES WED NIGHT/THU AS THE TROUGH MOVES OFF THE EAST COAST AND A LOW CONTINUES TO LIFT TOWARD HUDSONS BAY. CONSISTENCY GOOD FOR THE MID LEVEL RIDGE AXIS TO SHIFT RETROGRESS INTO WESTERN NOAM THU NIGHT INTO FRI NIGHT AND BROAD NORTHWEST FLOW TO SET UP OVER MUCH OF EASTERN NOAM. SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY THRU THE PERIOD BY ECMWF. CHECK OF OBS VS. MODEL DATA SHOWED ALL QUITE REASONABLE WITH THE SFC PRESSURE AND DEW POINT FIELDS OVER CENTRAL NOAM. PER WV IMAGERY...A BLEND OF THE MODELS LOOKED BEST WITH THE SHORTWAVE FEATURES OVER NOAM/EASTERN PAC. NO CLEAR MODEL FAVORITE AND WITH THE TREND TOWARD A TIGHTER... COMMON CONSENSUS...FAVORED A MODEL/ENSEMBLE BLEND THIS CYCLE. SHORT TERM FCST CONFIDENCE GENERALLY ON THE GOOD SIDE THIS CYCLE. IN THE SHORT TERM...WEAK SHORTWAVE OVER MN WILL SLIDE EAST OF THE AREA THIS EVENING WITH WITH HGTS RISING FOR LATER TONIGHT/WED AS A STRONGER SHORTWAVE/UPPER LOW LIFTS INTO CENTRAL CAN. SOUTH TO SOUTHWEST SFC-700MB FLOW...AHEAD OF THE TRAILING COLD FRONT/ TROUGH...CONTINUES TO INCREASE OVER THE AREA FOR LATE TONIGHT/WED. THIS FLOW PULLS A VERY WARM SFC-700MB AIRMASS NORTHWARD INTO THE AREA FOR WED. 850MB TEMPS IN THE 23C-29C RANGE /COOLER IN GFS/ BY 00Z THU. MIXING THESE TEMPS TO THE SFC WOULD GIVE HIGHS IN THE 90- 100F RANGE. THE INCREASING SOUTHWEST 925-850MB FLOW PUSHES THE PLAINS MOISTURE PLUME INTO THE AREA WED...WITH INCREASING DEW POINTS THRU THE DAY. MODEL SOUNDINGS INDICATE MIXED LAYER DEW POINTS IN THE MID/UPPER 60S WED AFTERNOON...APPROACHING 70F BY 00Z THU. HEAT INDICES ALONG/WEST OF THE MS RIVER LOOK TO CLIMB INTO THE 100-105 RANGE IN THE 2PM-7PM TIME-FRAME WED AFTERNOON. WILL ISSUE A HEAT ADVISORY FOR AREAS ALONG/WEST OF A MONDOVI WI...LA CROSSE...ELKADER IA LINE FOR 1PM TO 8PM WED AFTERNOON/EVENING. THE MORE MOIST SFC-850MB AIRMASS REMAINS OVER THE AREA FOR WED NIGHT/THU...AS THE TRAILING COLD FRONT SINKS SOUTH THRU THE FCST AREA. MODEL SOUNDINGS INDICATE WARM 850-700MB TEMPS AND RATHER STRONG CAPPING REMAINS IN PLACE...WEAKEST IN GFS WITH ITS MORE MOIST SFC-850MB LAYER. FRONT PUSHES THRU MOST OF THE FCST AREA IN THE 06- 18Z THU PERIOD...WITH BULK OF ANY FORCING/LIFT ALONG THE FRONT SOUTH OF THE AREA BY PEAK HEATING/INSTABILITY THU AFTERNOON. GFS HOLDS ONTO MORE POST-FRONTAL SFC-850MB MOISTURE AND POST-FRONTAL SOUTHWEST 850-700MB FLOW LATE WED NIGHT/THU. STRONG CAPPING IN THE 850-700MB LAYER LOOKS TO LIMIT CONVECTION LATE WED NIGHT/THU MORNING AND REMOVED SMALL SHRA/TSRA CHANCES FROM THESE TIME PERIODS. CONTINUED SMALL SHRA/TSRA CHANCES ACROSS MAINLY THE SOUTH/SOUTHWEST PARTS OF THE FCST AREA THU AFTERNOON/EVENING WITH THE FRONT...MOIST AIRMASS AND INSTABILITY IN THE AREA. FRONT PUSHES FURTHER SOUTH OF THE AREA FOR FRI WITH A WEAK BUBBLE OF HIGH PRESSURE BUILDING INTO THE UPPER MIDWEST. BULK OF LOWER LEVEL MOISTURE TRANSPORT/THETA-E CONVERGENCE ARE FOCUSED SOUTH/WEST OF THE FCST AREA WHILE SOME 850-700MB CAPPING REMAINS IN PLACE. LEFT FRIDAY DRY. FRONT AND MOISTURE TRANSPORT/THETA-E CONVERGENCE BEGIN TO SHIFT BACK TO THE NORTH FRI NIGHT AS WEAK LOW PRESSURE LIFTS NORTHEAST ACROSS THE CENTRAL PLAINS. PLENTY OF MODEL DETAIL DIFFERENCES BY FRI NIGHT BUT CONTINUED A SMALL SHRA/TSRA CHANCE ACROSS THE SOUTHWEST END OF THE FCST AREA FOR FRI NIGHT. USED A BLEND OF THE GUIDANCE TEMPS FOR LOWS TONIGHT THRU FRI NIGHT. WITH THE WARM 850MB TEMPS...PLENTY OF SUNSHINE AND THE SOUTHWEST WINDS FOR MIXING...TRENDED TOWARD WARMER OF GUIDANCE HIGHS FOR WED. TRENDED TOWARD WARMER OF GUIDANCE HIGHS FOR THU AS WELL. USED A BLEND OF THE GUIDANCE HIGHS FOR FRI. .LONG TERM...SATURDAY THROUGH TUESDAY 325 PM CDT TUE JUN 26 2012 26.00 MEDIUM RANGE MODELS IN REASONABLY GOOD AGREEMENT WITH EACH OTHER AND THEIR PREVIOUS RUNS SAT/SUN. THE REGION REMAINS UNDER BROAD NORTHWEST FLOW ALOFT WHILE A MID LEVEL RIDGE AXIS TO SLOWLY PROGRESSES EAST INTO THE CENTRAL PLAINS TO SOUTH-CENTRAL CAN. MODELS BEGIN TO DIFFER FOR MON/TUE...WITH TIMING/STRENGTH OF A SHORTWAVE TROUGH TO TWO WHICH FLATTEN THE PLAINS RIDGING AND MOVE TOWARD/INTO THE UPPER MIDWEST FOR EARLY NEXT WEEK. NO MODEL WITH OBVIOUS BETTER RUN-TO-RUN CONSISTENCY IN THE DAY 4-7 PERIOD. BETTER CONFIDENCE IN THE LONG TERM PERIOD IS FOR TEMPS TO BE ABOVE NORMAL FOR SAT-TUE. WITH SUBTLE DETAIL/SHORTWAVE DIFFERENCES ON WEAK PIECES OF ENERGY THRU THE BROAD NORTHWEST FLOW SAT/SUN AND THE LARGER MODEL DIFFERENCES BY MON/TUE...COULD ARGUE FOR 15 TO 30 PERCENT SHRA/TSRA CHANCES EACH DAY. WITH THESE DIFFERENCES BETWEEN THE MODELS ON THE SMALL SCALE/CONVECTIVE DETAILS...CONFIDENCE QUITE LOW ON RAIN CHANCES IN THE SAT-TUE PERIOD. SOME CONSENSUS FOR A SHORTWAVE TROUGH TO PASS SAT...WEAK HIGH PRESSURE TO BE BUILDING INTO/ACROSS THE REGION SUN/MON...THEN ANOTHER SHORTWAVE PASSAGE FOR TUE. CARRIED SHRA/TSRA CHANCES SAT AND TUE BUT LEFT RAIN CHANCES OUT OF MOST/ALL OF THE AREA FOR SUN/MON. BLEND OF GUIDANCE HIGHS/LOWS FOR SAT THRU TUE LOOK GOOD AT THIS TIME. && .AVIATION...THROUGH 06Z THURSDAY 1152 PM CDT TUE JUN 26 2012 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH CLEAR SKIES TONIGHT AND SOME SCATTERED TO BROKEN CIRRUS AFTER 21Z WEDNESDAY. LOW LEVEL JET DOES INCREASE OVERNIGHT...BUT 27.02Z RAP NOW SHOWS 35 TO 40 KNOT WINDS AT 2K FEET BETWEEN 09Z-12Z. WITH SURFACE WINDS STAYING UP DUE TO THE GRADIENT WILL NOT BE MENTIONING ANY LLWS. && .FIRE WEATHER...WEDNESDAY AND THURSDAY 325 PM CDT TUE JUN 26 2012 THE COMBINATION OF A VERY HOT AND DRY AIR MASS WILL LEAD TO AN ELEVATED FIRE DANGER FOR PARTS OF SOUTHERN WISCONSIN...MAINLY ALONG AND SOUTH OF A MAUSTON TO PRAIRIE DU CHIEN LINE. MINIMUM RELATIVE HUMIDITIES IN THIS AREA WILL DROP TO AROUND 30 PERCENT. HIGHS ON WEDNESDAY WILL RANGE FROM NEAR 90 ACROSS NORTH CENTRAL WISCONSIN...TO MID AND UPPER 90S ACROSS THE REST OF THE AREA. IT WILL ALSO BE QUITE BREEZY...WITH SOUTHERLY WINDS SUSTAINED WINDS AROUND 15 MPH...AND GUSTS UP TO 30 MPH EXPECTED. THE COMBINATION OF THE HEAT AND HUMIDITY WILL PRODUCE HEAT INDEX VALUES BETWEEN 100 TO 105 DURING THE AFTERNOON HOURS. ON THURSDAY...ANOTHER HOT AND DRY DAY IS EXPECTED...ALTHOUGH HIGHS WILL BE A FEW DEGREES COOLER AND DEW POINTS A BIT HIGHER AS WELL...WHICH WILL PRODUCE MINIMUM RH VALUES IN THE MID TO UPPER 40S. A COLD FRONT WILL SWEEP THROUGH DURING THE AFTERNOON...AND BRING A VERY SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WITH LOW CONFIDENCE ON WIDESPREAD WETTING RAINS. LOOKING AHEAD...WARM CONDITIONS WILL PERSIST FRIDAY AND THROUGH THE WEEKEND. A FRONTAL BOUNDARY WILL SETTLE SOUTH OF THE AREA SATURDAY...AND THIS WILL PRODUCE SMALL CHANCES OF SHOWERS/THUNDERSTORMS. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 PM CDT TUE JUN 26 2012 WI...HEAT ADVISORY FROM 1 PM TO 8 PM CDT WEDNESDAY FOR WIZ032-033- 041. MN...HEAT ADVISORY FROM 1 PM TO 8 PM CDT WEDNESDAY FOR MNZ079- 086>088-094>096. IA...HEAT ADVISORY FROM 1 PM TO 8 PM CDT WEDNESDAY FOR IAZ008>011- 018-019-029-030. && $$ SHORT TERM.....RRS LONG TERM......RRS AVIATION...RABERDING FIRE WEATHER...ZT
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1150 PM CDT TUE JUN 26 2012 .UPDATE... .AVIATION/06Z TAFS/... SCATTERED TO BROKEN CI/AC...CONVECTIVE DEBRIS FROM LAST NIGHT/S THUNDERSTORMS IN THE DAKOTAS...WILL CLEAR EASTERN WI BY 09Z. LITTLE IN THE WAY OF CLOUDS OR SURFACE WINDS THROUGH SUNRISE. 00Z NAM SOUNDINGS CONFIRM LOW-LEVEL WIND SHEAR CRITERIA WILL BE MET AT KMSN AROUND 08Z...BUT THE STRONGER 1000-1500 FT WINDS WILL NOT MAKE THE EASTERN TAF SITES BEFORE DAYTIME MIXING BRINGS THE SURFACE WINDS UP TO PREVENT THE SPEED DIFFERENTIAL NEEDED. GUSTY SOUTH- SOUTHWEST WINDS DURING THE DAY...WITH ONLY DEBRIS FROM WESTERN CONVECTION SPILLING OVER RIDGE INTO REGION. VFR CONDITIONS THROUGH THE PERIOD WITH HOT HIGH TEMPERATURES IN THE 90S. && .PREV DISCUSSION... /ISSUED 318 PM CDT TUE JUN 26 2012/ TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH. LARGE MID/UPPER LEVEL RIDGE EXTENDING FROM WESTERN TEXAS THROUGH MINNESOTA...COUPLED WITH AN 850MB THERMAL RIDGE WITH TEMPS IN THE VERY WARM 23 TO 28C RANGE...WILL LEAN SOUTHEASTWARD INTO SOUTHERN WI WED THROUGH THU. THIS WILL BRING A SHORT-LIVED HEAT WAVE INTO SOUTH CENTRAL AND SOUTHEAST WI THIS WEEK. AT THE SURFACE...HIGH PRESSURE OVER LAKE MICHIGAN WILL SHIFT SOUTHEAST TOWARD THE OHIO RIVER VALLEY TONIGHT. THERE WILL ONLY BE A FEW CIRRUS CLOUDS DRIFTING ACROSS THE STATE MAINLY THIS EVENING THEN CLEAR THROUGH WEDNESDAY. INCREASING PRESSURE GRADIENT WILL BRING GUSTY SSW WINDS TO THE ENTIRE FORECAST AREA ON WEDNESDAY. BREEZY WINDS 10 TO 20 MPH WITH GUSTS TO 25 MPH EXPECTED. THE BLOW TORCH WILL BE ON WITH DRY ADIABATIC MIXING UP TO 925MB TEMPS OF AROUND 28C...WHICH IS A COMPROMISE BETWEEN MANY VARYING MODEL SOLUTIONS...YIELDING MAX TEMPS IN THE MID 90S. BUMPED THESE VALUES UP A DEGREE OR TWO IN THE FAVORABLE HOT SPOTS. EVEN THOUGH THU IS BEING ADVERTISED FOR THE HEAT AND HIGH HEAT INDICES...WED MAY END UP HAVING THE HOTTEST TEMPERATURES FOR LOCATIONS ESPECIALLY IN THE NORTHERN FORECAST AREA. THE DIFFERENCE WILL BE THE HUMIDITY. DEEP LOW LEVEL MIXING OF DRY AIR WILL KEEP THE DEWPOINT TEMPERATURES RELATIVELY LOW ON WED IN THE LOW TO MID 50S...LEADING TO RELATIVE HUMIDITY VALUES IN THE 25 TO 30 PERCENT RANGE. WITH THE GRASS AND OTHER VEGETATION BEING PRETTY DRY DUE TO THE LACK OF RECENT RAINFALL...CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED FOR WEDNESDAY. WEDNESDAY NIGHT AND THURSDAY - CONFIDENCE...MEDIUM AMPLITUDE OF UPPER RIDGING REACHED ITS PEAK ACROSS THE AREA ON WEDNESDAY. 500 MILLIBAR THEN FLATTENS WEDNESDAY NIGHT AND THURSDAY. VERY WARM NIGHT WEDNESDAY NIGHT WITH ECMWF SUGGESTING READINGS IN THE MID 70S TO AROUND 80 FOR LOWS. PREFER THE DRIER LOOK THE 12Z NAM/00Z ECMWF WITH QPF ON THURSDAY. SOUTHWEST WINDS SHIFT NORTHWEST IN THE WAKE OF A WEAK FRONTAL BOUNDARY THURSDAY MORNING. SOME TIMING DIFFERENCES. NEVERTHELESS 925/850 TEMPS DO NOT TAIL OFF TOO MUCH. 925 TEMPS STILL IN THE UPPER 20SC/LOW 30SC. AFTERNOON RELIEF EXPECTED NEAR THE LAKE AS LAKE BREEZE KICKS IN. INLAND...GOING OFF STRICTLY THE 925/850 TEMP TECHNIQUE...MAY REACH THE UPPER 90S WITH SOME 100 DEGREE READINGS PLAUSIBLE. LIGHTER WINDS IN LOWER LEVELS MAY RESULT IN BETTER MOISTURE POOLING...AND HIGHER DEW POINTS. GFS AND GEM ARE BOTH CONVECTING WHILE THE ECMWF IS DRY. 700 TEMPS ARE AT OR ABOVE 12C SO THINK BREAKING THE CAP MAY BE REAL TOUGH. THE NEED FOR A HEAT ADVISORY APPEARS LIKELY FOR MOST OF SOUTHERN WISCONSIN...WITH RELIEF POTENTIAL HIGHEST IN THE FAR EAST NEAR LAKE MI. FRIDAY - CONFIDENCE...MEDIUM WNW UPPER FLOW. CORE OF THE HOT AXIS TO OUR SOUTH. ECMWF HAS THE HOTTEST 925 TEMPS STILL NUDGING INTO THE CWA...GFS WELL SOUTH. THE NAM IS A DECENT COMPROMISE. STILL KEEPS US WELL INTO THE 90S. PREFER THE DRIER AND LESS NOISY LOOK OF THE ECMWF/NAM VERSUS THE GFS/GEM. FRIDAY NIGHT AND SATURDAY - CONFIDENCE...MEDIUM GFS AND GEM CONTINUE WITH NOISY VORTS WITHIN THE WNW 500 MILLIBAR FLOW SUGGESTING SOME RAIN. MEANWHILE THE ECMWF SHOWS MORE OF A BROAD ANTICYCLONIC FLOW WITH A CONTINUATION OF THE HOT CONDITIONS WITH 925 TEMPS IN THE UPPER 20S/LOW 30S. LEANING DRY LOOK AT THIS POINT. SATURDAY NIGHT AND SUNDAY - CONFIDENCE...MEDIUM AN OPPORTUNITY FOR RAIN WITH MODELS HINTING AT SHORTWAVE IN THE NW UPPER FLOW. ONCE AGAIN THE GFS IS SHOWING THE WET LOOK SO FROM A WISHCASTING POINT OF VIEW THIS WOULD BE THE MODEL OF CHOICE. THE ECMWF IS SHOWING THIS WAVE AS BEING LEGIT THOUGH BULK OF PRECIP TO THE SOUTH. MONDAY - CONFIDENCE...MEDIUM RIDGING BUILDS IN AHEAD OF NEXT WAVE. GFS LOOKS TOO FAST. HINTS OF WAA INDUCED PRECIP...QUITE LIGHT ON THE ECMWF. GFS LOOKS OVERBLOWN. TUESDAY - CONFIDENCE...LOW TO MEDIUM AGAIN GFS MORE PROGRESSIVE WITH THE WAVE WHILE 00Z ECMWF SLOWER. 12Z RUN SHOWS A LITTLE MORE ACCELERATION THOUGH PRECIP LARGELY TO OUR NORTHWEST. AVIATION/00Z TAFS/...VFR CONDITIONS THROUGH THE PERIOD. CLEAR SKIES AND LIGHT WINDS THROUGH MIDNIGHT WITH SURFACE HIGH CENTERED OVER LAKE MICHIGAN SLOWLY DRIFTING SOUTHEAST. ONLY CLOUDS EXPECTED WILL BE SOME CIRRUS SPILLING OVER THE RIDGE INTO SOUTHERN WI THIS EVENING. AS THE RIDGING SHIFTS TO THE SOUTHEAST AND THE PRESSURE GRADIENT TIGHTENS... NAM AND RAP MODEL FORECAST SOUNDINGS CRANK WINDS UP TO BETWEEN 35 AND 40 KNOTS AFTER 08Z WEDNESDAY WITHIN 1500 FT OVER A SHALLOW INVERSION. THESE WINDS ARE MUCH WEAKER ON THE GFS SO THERE IS SOME UNCERTAINTY... HOWEVER MENTIONED THE WIND SHEAR IN THE MSN TAF. SOUTH TO SOUTHWEST WINDS INCREASE QUICKLY WEDNESDAY MORNING...WITH GUSTS TO 22 TO 25KT EXPECTED BY LATE MORNING AND PERSISTING THROUGH THE LATE AFTERNOON. HIGHEST WIND GUSTS WILL BE IN THE WESTERN FORECAST AREA INCLUDING MSN. HOT TEMPERATURES IN THE MID/UPPER 90S. MARINE...SOUTH WINDS WILL INCREASE ACROSS THE NEARSHORE WATERS WEDNESDAY MORNING AS THE SURFACE PRESSURE GRADIENT TIGHTENS AND A VERY WARM AIRMASS MOVES INTO THE REGION. WINDS MAY BECOME SOUTHEAST DURING THE AFTERNOON. WIND GUSTS WILL APPROACH SMALL CRAFT ADVISORY LEVELS...UP TO 23 KNOTS. SUBSEQUENT WAVES SHOULD REMAIN BELOW CRITERIA. GIVEN THE BORDERLINE SCENARIO AND LAKE TEMPERATURES COOLER THAN THE LAND TEMPERATURES HAVING A STABILIZING EFFECT...DID NOT ISSUE A SMALL CRAFT ADVISORY HEADLINE. FIRE WEATHER...BREEZY SOUTH WINDS OF 10 TO 20 MPH WITH WIND GUSTS TO 25 MPH WILL BRING VERY WARM TEMPERATURES INTO THE MID/UPPER 90S. DEEP LOW LEVEL MIXING OF DRY AIR WILL KEEP THE DEWPOINT TEMPERATURES RELATIVELY LOW IN THE LOW TO MID 50S...LEADING TO RELATIVE HUMIDITY VALUES IN THE 23 TO 30 PERCENT RANGE. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED FOR WEDNESDAY... WITH THE GRASS AND OTHER VEGETATION BEING PRETTY DRY DUE TO THE LACK OF RECENT RAINFALL. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...REM TONIGHT/WEDNESDAY AND AVIATION/MARINE...MRC WEDNESDAY NIGHT THROUGH TUESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS ALBANY NY
520 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WEAK FRONT WILL MOVE ACROSS THE REGION THIS MORNING...AS HIGH PRESSURE WILL BUILD IN FROM THE WESTERN GREAT LAKES REGION THIS AFTERNOON WITH HOT...BREEZY...AND DRY WEATHER. ABOVE NORMAL TEMPERATURES WILL PERSIST DURING THE WEEKEND. AN UPPER LEVEL DISTURBANCE...AND A WEAK COOL FRONT MAY FOCUS SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON INTO THE EVENING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 515 AM EDT...QUICK UPDATE TO EXPAND THE POPS TO CHANCE VALUES TO EMPHASIZE SCT SHOWERS WITH ISOLD THUNDERSTORMS BASED ON THE REGIONAL AND KENX RADAR IMAGERY. THE THUNDERSTORMS TO THE NORTH AND WEST OF THE CAPITAL REGION ARE WEAKENING. A BAND OF SHOWERS AND THUNDERSTORMS ARE MOVING ACROSS THE WRN MOHAWK VALLEY...EXTENDING FROM I-90 SOUTH TO I-88 AHEAD OF THE COOL FRONT. THIS BAND WILL MOVE ACROSS THE CAPITAL REGION BETWEEN 09Z-10Z...AND THEN WRN NEW ENGLAND BETWEEN 10Z-12Z. PREVIOUS NEAR TERM DISCUSSION... AS OF 415 AM EDT...THE WATER VAPOR LOOP THIS MORNING SHOWS A BROAD MID LEVEL RIDGE CENTERED OVER THE TN VALLEY. AN IMPULSE IN THE W/NW FLOW MOVING ALONG THE PERIPHERY OF THE RIDGE HAS FOCUSED A MESOSCALE CONVECTIVE SYSTEM /MCS/ FORMING OVER W-CNTRL PA. THE MCS IS FIRING AHEAD OF A WEAK COLD FRONT. A SHORT-WAVE TROUGH IS MOVING EAST OF LAKE ONTARIO THIS MORNING. ISOLD-SCT SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE TUG HILL PLATEAU. SOME OF THESE WILL MOVE INTO THE ADIRONDACKS BETWEEN 08Z-10Z. THESE SHOWERS AND THUNDERSTORMS ARE FORMING IN THE NARROW WARM SECTOR BETWEEN A WEAK COOL AND WARM FRONT. OTHER ISOLD SHOWERS AND THUNDERSTORMS ARE PROGRESSING ACROSS THE CATSKILLS...AND INTO THE HUDSON RIVER VALLEY BTWN 08Z-10Z. THERE IS SOME INSTABILITY WITH MUCAPES OF AROUND 500 J/KG WITH POCKETS UP TO A 1000 J/KG. MOST OF THIS INSTABILITY IS ELEVATED WITH SHOWALTER VALUES OF 0 TO -2C. H700-500 LAPSE RATES ARE IN THE 6.5 TO 7C/KM RANGE. SFC DEWPTS ARE IN THE MID 50S TO L60S. THE LATEST HRRR HAS MOST OF THIS ACTIVITY MOVING EAST OF THE FCST AREA BY 12Z. WE HAVE TRENDED IT QUICKLY THROUGH THE AREA BY THE MID TO LATE MORNING. HIGH PRESSURE WILL BE BUILDING IN FROM THE W-CNTRL GREAT LAKES REGION. THE WATER VAPOR LOOP SHOWS A LOT OF MID AND UPPER LEVEL DRYING OVER THE ERN GREAT LAKES REGION...AND SE ONTARIO. THE STRONG SUBSIDENCE IN THE WAKE OF FRONT SHOULD ALLOW FOR MOSTLY SUNNY AND HOT CONDITIONS WITH H850 TEMPS IN THE 17C TO 20C RANGE. DEEP MIXING TO AROUND H850 WILL ALLOW BREEZY CONDITIONS WITH HIGHS IN THE U80S TO L90S IN THE VALLEYS /A FEW MID 90S IN THE MID HUDSON VALLEY/ AND U70S TO M80S OVER THE HILLS AND MTNS. IT WILL BE BREEZY WITH WEST WINDS OF 1O TO 20 MPH IN THE AFTERNOON WITH GUSTS IN THE 25 TO 35 MPH RANGE. THE SFC DEWPOINTS WILL BE MAINLY IN THE 50S. HEAT INDICES ARE NOT EXPECTED TO REACH THE ADVISORY RANGE WITH THE LOWERING SFC DEWPTS AND RH VALUES. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... FRIDAY NIGHT...A QUIET AND SEASONABLY COOL LATE JUNE EVENING IS EXPECTED WITH MOSTLY CLEAR/CLEAR SKIES...AND LIGHT TO CALM WINDS...AS A WEAK SFC ANTICYCLONE BUILDS IN FROM THE GREAT LAKES REGION AND THE OHIO VALLEY. RADITIONAL COOLING SHOULD ALLOW TEMPS TO FALL BACK INTO THE 50S TO L60S WITH A FEW U40S OVER THE SRN DACKS. THERE MAYBE SOME PATCHY FOG NEAR THE CT RIVER VALLEY. WE PLACED IT IN NEAR ERN WINDHAM CTY BETWEEN 09Z-12Z. SATURDAY...A NICE WARM DAY IS EXPECTED TO START...THEN ANOTHER WEAK COLD FRONT AND ITS ASSOCIATED MID LEVEL SHORT-WAVE MAY FOCUS ISOLD SHOWERS AND THUNDERSTORMS IN AFTERNOON FROM THE CAPITAL REGION NORTH AND WEST...AND SCT SHOWERS WITH ISOLD THUNDERSTORMS SOUTH AND EAST. LIMITED INSTABILITY OF 500-100 J/KG IS EXPECTED SOUTH OF THE CAPITAL REGION WITH MID LEVEL LAPSE RATES APPROACHING 7C/KM AGAIN. THE CONVERGENCE LOOKS WEAK WITH THE DISTURBANCE. THE BEST DEEP SHEAR OF 30-40 KTS IS OVER THE SOUTHERN ZONES. WE ARE NOT EXPECTING ANY SVR THUNDERSTORMS AT THIS TIME..BUT A FEW COULD BE STRONG IF GREATER AMOUNTS OF INSTABILITY ARE IN PLACE. MAX TEMPS COULD REACH IN THE U80S TO L90S ONCE AGAIN IN THE VALLEYS...WITH U70S TO M80S OVER THE HILLS/MTNS. SATURDAY NIGHT...THE MID LEVEL IMPULSE AND COLD FRONT MOVE EAST OF THE REGION WITH THE ISOLD-SCT SHOWER AND THUNDERSTORM ACTIVITY ENDING. MIN TEMPS WILL BE WARMER THAN THE PREVIOUS NIGHT WITH MID AND UPPER 50S NORTH OF THE MOHAWK VALLEY/CAPITAL REGION...AND LOWER TO MID 60S FROM THESE LOCATIONS SOUTH AND EAST. SUNDAY/SUNDAY NIGHT...THE SHORT RANGE GUIDANCE IS INDICATING THE LONGWAVE TROUGH AXIS WILL REMAIN UPSTREAM OF ERN NY AND WRN NEW ENGLAND TO START THE DAY. SOME ISOLD SHOWERS OR THUNDERSTORMS MAY FORM AHEAD OF THE UPPER LEVEL TROUGH AXIS. SOME SLIGHT CHC POPS WERE LEFT IN THE GRIDDED FORECAST. THE DEGREE OF INSTABILITY IS IN QUESTION FOR GREATER THUNDERSTORM CHANCES. TEMPS SHOULD STILL RUN A LITTLE ABOVE NORMAL TO CLOSE THE WEEKEND. && .LONG TERM /MONDAY THROUGH THURSDAY/... NO BIG CHANGES IN THE EXPECTED LONGWAVE PATTERN FOR THE PERIOD WITH A TROUGH OVER THE NORTHWEST AND NORTHEAST WITH RIDGING ACROSS THE REST OF THE CONUS. SHORT WAVES WILL MOVE THROUGH THE TROUGH. THE GFS BECOMES MORE AMPLIFIED WITH THE PATTERN NEXT WEEK. HOWEVER THE HYDROMETEOROLOGICAL PREDICTION CENTER CONTINUES TO FAVOR THE ECMWF ENSEMBLE MEAN FOR THE PERIOD WHICH INDICATES A DRIER FORECAST. SO HAVE KEPT THE FORECAST SIMPLE WITH LOW CLIMATOLOGICAL POPS THROUGH MUCH OF THE PERIOD. AS FOR TEMPERATURES...SEASONABLE TO SLIGHTLY ABOVE FOR OUR NEXT OF THE WOODS WITH THE HEAT CONTINUING ACROSS MUCH OF THE INTERIOR UNITED STATES. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... MAINLY VFR CONDITIONS ARE EXPECTED THROUGH...06Z/SATURDAY. CONVECTION WILL CONTINUE TO MOVE EASTWARD ACROSS THE FORECAST AREA EARLY THIS MORNING AS A WEAK WARM FRONT MOVES THROUGH ALONG WITH A MID LEVEL SHORT WAVE. BASED ON RADAR AND TRENDS HAVE CONVECTION IN TAFS USING TEMPO GROUPS. THE WINDOW FOR CONVECTION WILL CONTINUE UNTIL ABOUT 13Z. CLOUD COVER WILL THEN DECREASE. WINDS WILL BECOME WESTERLY AND INCREASE TO 12 TO 18 KNOTS WITH GUSTS IN THE 20S WITH THE STRONGEST WINDS AT KALB. THE WINDS WILL DIMINISH THIS EVENING. OUTLOOK... SAT...VFR. SLIGHT CHC AFTERNOON -SHRA/-TSRA. SAT NIGHT...VFR. NO SIG WX. SUN...VFR. SLIGHT CHC AFTERNOON -SHRA/-TSRA. SUN NIGHT...MAINLY VFR. SLIGHT CHC -SHRA. MON...VFR. CHC MAINLY AFTERNOON -SHRA/-TSRA. TUE...VFR. NO SIG WX. && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITIES 25 TO 30 PERCENT THIS AFTERNOON ACROSS THE MID HUDSON VALLEY REGION... WIND GUSTS OF 25-35 MPH POSSIBLE THIS AFTERNOON IN THE MOHAWK VALLEY REGION...CAPITAL REGION...NORTHERN CATSKILLS...AND BERKSHIRES... A WEAK FRONT WILL MOVE ACROSS THE REGION THIS MORNING...AS HIGH PRESSURE WILL BUILD IN FROM THE WESTERN GREAT LAKES REGION THIS AFTERNOON WITH HOT...BREEZY...AND DRY WEATHER. ABOVE NORMAL TEMPERATURES WILL PERSIST DURING THE WEEKEND. AN UPPER LEVEL DISTURBANCE...AND A WEAK COOL FRONT MAY FOCUS SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON INTO THE EVENING. THE RH WILL FALL INTO THE 25-35 PERCENT RANGE IN THE VALLEYS...AND THE 35-50 PERCENT RANGE ACROSS THE HIGHER ELEVATIONS FRIDAY AFTERNOON. THE RH WILL HAVE AN EXCELLENT RECOVERY TO 80-100 PERCENT SATURDAY MORNING. DEW FORMATION IS LIKELY. THE RH VALUES WILL LOWER TO 25 TO 45 PERCENT ONCE AGAIN SATURDAY AFTERNOON. THE WINDS WILL VEER FROM THE SOUTH OR SOUTHWEST THIS MORNING...TO THE WEST BY THE AFTERNOON AT 10 TO 20 MPH...WITH SOME GUSTS IN THE 25 TO 35 MPH RANGE. THE WINDS WILL BECOME LIGHT AND VARIABLE AT 5 MPH OR LESS FRIDAY NIGHT. EXPECT WEST/SOUTHWEST WINDS OF 10 TO 20 MPH ON SATURDAY. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THE NEXT 5 DAYS. A WEAK FRONT WILL MOVE ACROSS THE HYDRO SERVICE AREA THIS MORNING WITH ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS. RAINFALL AMOUNTS WILL GENERALLY BE LIGHT WITH A FEW HUNDREDTHS TO A FEW TENTHS OF AN INCH. HIGH PRESSURE BRIEFLY BUILD THIS AFTERNOON THROUGH SATURDAY MORNING. ANOTHER WEAK COOL FRONT...AND AN UPPER LEVEL DISTURBANCE WILL BRING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON AND SATURDAY NIGHT. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE. CYCLONIC FLOW ALOFT MAY ALLOW ISOLATED SHOWERS...AND PERHAPS THUNDERSTORMS SUNDAY INTO EARLY NEXT WEEK. AGAIN...NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...WASULA NEAR TERM...WASULA SHORT TERM...WASULA LONG TERM...IAA AVIATION...IAA FIRE WEATHER...KL/WASULA HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
434 AM EDT FRI JUN 29 2012 .SYNOPSIS...A WEAK FRONT WILL MOVE ACROSS THE REGION THIS MORNING...AS HIGH PRESSURE WILL BUILD IN FROM THE WESTERN GREAT LAKES REGION THIS AFTERNOON WITH HOT...BREEZY...AND DRY WEATHER. ABOVE NORMAL TEMPERATURES WILL PERSIST DURING THE WEEKEND. AN UPPER LEVEL DISTURBANCE...AND A WEAK COOL FRONT MAY FOCUS SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON INTO THE EVENING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 415 AM EDT...THE WATER VAPOR LOOP THIS MORNING SHOWS A BROAD MID LEVEL RIDGE CENTERED OVER THE TN VALLEY. AN IMPULSE IN THE W/NW FLOW MOVING ALONG THE PERIPHERY OF THE RIDGE HAS FOCUSED A MESOSCALE CONVECTIVE SYSTEM /MCS/ FORMING OVER W-CNTRL PA. THE MCS IS FIRING AHEAD OF A WEAK COLD FRONT. A SHORT-WAVE TROUGH IS MOVING EAST OF LAKE ONTARIO THIS MORNING. ISOLD-SCT SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE TUG HILL PLATEAU. SOME OF THESE WILL MOVE INTO THE ADIRONDACKS BETWEEN 08Z-10Z. THESE SHOWERS AND THUNDERSTORMS ARE FORMING IN THE NARROW WARM SECTOR BETWEEN A WEAK COOL AND WARM FRONT. OTHER ISOLD SHOWERS AND THUNDERSTORMS ARE PROGRESSING ACROSS THE CATSKILLS...AND INTO THE HUDSON RIVER VALLEY BTWN 08Z-10Z. THERE IS SOME INSTABILITY WITH MUCAPES OF AROUND 500 J/KG WITH POCKETS UP TO A 1000 J/KG. MOST OF THIS INSTABILITY IS ELEVATED WITH SHOWALTER VALUES OF 0 TO -2C. H700-500 LAPSE RATES ARE IN THE 6.5 TO 7C/KM RANGE. SFC DEWPTS ARE IN THE MID 50S TO L60S. THE LATEST HRRR HAS MOST OF THIS ACTIVITY MOVING EAST OF THE FCST AREA BY 12Z. WE HAVE TRENDED IT QUICKLY THROUGH THE AREA BY THE MID TO LATE MORNING. HIGH PRESSURE WILL BE BUILDING IN FROM THE W-CNTRL GREAT LAKES REGION. THE WATER VAPOR LOOP SHOWS A LOT OF MID AND UPPER LEVEL DRYING OVER THE ERN GREAT LAKES REGION...AND SE ONTARIO. THE STRONG SUBSIDENCE IN THE WAKE OF FRONT SHOULD ALLOW FOR MOSTLY SUNNY AND HOT CONDITIONS WITH H850 TEMPS IN THE 17C TO 20C RANGE. DEEP MIXING TO AROUND H850 WILL ALLOW BREEZY CONDITIONS WITH HIGHS IN THE U80S TO L90S IN THE VALLEYS /A FEW MID 90S IN THE MID HUDSON VALLEY/ AND U70S TO M80S OVER THE HILLS AND MTNS. IT WILL BE BREEZY WITH WEST WINDS OF 1O TO 20 MPH IN THE AFTERNOON WITH GUSTS IN THE 25 TO 35 MPH RANGE. THE SFC DEWPOINTS WILL BE MAINLY IN THE 50S. HEAT INDICES ARE NOT EXPECTED TO REACH THE ADVISORY RANGE WITH THE LOWERING SFC DEWPTS AND RH VALUES. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... FRIDAY NIGHT...A QUIET AND SEASONABLY COOL LATE JUNE EVENING IS EXPECTED WITH MOSTLY CLEAR/CLEAR SKIES...AND LIGHT TO CALM WINDS...AS A WEAK SFC ANTICYCLONE BUILDS IN FROM THE GREAT LAKES REGION AND THE OHIO VALLEY. RADITIONAL COOLING SHOULD ALLOW TEMPS TO FALL BACK INTO THE 50S TO L60S WITH A FEW U40S OVER THE SRN DACKS. THERE MAYBE SOME PATCHY FOG NEAR THE CT RIVER VALLEY. WE PLACED IT IN NEAR ERN WINDHAM CTY BETWEEN 09Z-12Z. SATURDAY...A NICE WARM DAY IS EXPECTED TO START...THEN ANOTHER WEAK COLD FRONT AND ITS ASSOCIATED MID LEVEL SHORT-WAVE MAY FOCUS ISOLD SHOWERS AND THUNDERSTORMS IN AFTERNOON FROM THE CAPITAL REGION NORTH AND WEST...AND SCT SHOWERS WITH ISOLD THUNDERSTORMS SOUTH AND EAST. LIMITED INSTABILITY OF 500-100 J/KG IS EXPECTED SOUTH OF THE CAPITAL REGION WITH MID LEVEL LAPSE RATES APPROACHING 7C/KM AGAIN. THE CONVERGENCE LOOKS WEAK WITH THE DISTURBANCE. THE BEST DEEP SHEAR OF 30-40 KTS IS OVER THE SOUTHERN ZONES. WE ARE NOT EXPECTING ANY SVR THUNDERSTORMS AT THIS TIME..BUT A FEW COULD BE STRONG IF GREATER AMOUNTS OF INSTABILITY ARE IN PLACE. MAX TEMPS COULD REACH IN THE U80S TO L90S ONCE AGAIN IN THE VALLEYS...WITH U70S TO M80S OVER THE HILLS/MTNS. SATURDAY NIGHT...THE MID LEVEL IMPULSE AND COLD FRONT MOVE EAST OF THE REGION WITH THE ISOLD-SCT SHOWER AND THUNDERSTORM ACTIVITY ENDING. MIN TEMPS WILL BE WARMER THAN THE PREVIOUS NIGHT WITH MID AND UPPER 50S NORTH OF THE MOHAWK VALLEY/CAPITAL REGION...AND LOWER TO MID 60S FROM THESE LOCATIONS SOUTH AND EAST. SUNDAY/SUNDAY NIGHT...THE SHORT RANGE GUIDANCE IS INDICATING THE LONGWAVE TROUGH AXIS WILL REMAIN UPSTREAM OF ERN NY AND WRN NEW ENGLAND TO START THE DAY. SOME ISOLD SHOWERS OR THUNDERSTORMS MAY FORM AHEAD OF THE UPPER LEVEL TROUGH AXIS. SOME SLIGHT CHC POPS WERE LEFT IN THE GRIDDED FORECAST. THE DEGREE OF INSTABILITY IS IN QUESTION FOR GREATER THUNDERSTORM CHANCES. TEMPS SHOULD STILL RUN A LITTLE ABOVE NORMAL TO CLOSE THE WEEKEND. && .LONG TERM /MONDAY THROUGH THURSDAY/... NO BIG CHANGES IN THE EXPECTED LONGWAVE PATTERN FOR THE PERIOD WITH A TROUGH OVER THE NORTHWEST AND NORTHEAST WITH RIDGING ACROSS THE REST OF THE CONUS. SHORT WAVES WILL MOVE THROUGH THE TROUGH. THE GFS BECOMES MORE AMPLIFIED WITH THE PATTERN NEXT WEEK. HOWEVER THE HYDROMETEOROLOGICAL PREDICTION CENTER CONTINUES TO FAVOR THE ECMWF ENSEMBLE MEAN FOR THE PERIOD WHICH INDICATES A DRIER FORECAST. SO HAVE KEPT THE FORECAST SIMPLE WITH LOW CLIMATOLOGICAL POPS THROUGH MUCH OF THE PERIOD. AS FOR TEMPERATURES...SEASONABLE TO SLIGHTLY ABOVE FOR OUR NEXT OF THE WOODS WITH THE HEAT CONTINUING ACROSS MUCH OF THE INTERIOR UNITED STATES. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... MAINLY VFR CONDITIONS ARE EXPECTED THROUGH...06Z/SATURDAY. CONVECTION WILL CONTINUE TO MOVE EASTWARD ACROSS THE FORECAST AREA EARLY THIS MORNING AS A WEAK WARM FRONT MOVES THROUGH ALONG WITH A MID LEVEL SHORT WAVE. BASED ON RADAR AND TRENDS HAVE CONVECTION IN TAFS USING TEMPO GROUPS. THE WINDOW FOR CONVECTION WILL CONTINUE UNTIL ABOUT 13Z. CLOUD COVER WILL THEN DECREASE. WINDS WILL BECOME WESTERLY AND INCREASE TO 12 TO 18 KNOTS WITH GUSTS IN THE 20S WITH THE STRONGEST WINDS AT KALB. THE WINDS WILL DIMINISH THIS EVENING. OUTLOOK... SAT...VFR. SLIGHT CHC AFTERNOON -SHRA/-TSRA. SAT NIGHT...VFR. NO SIG WX. SUN...VFR. SLIGHT CHC AFTERNOON -SHRA/-TSRA. SUN NIGHT...MAINLY VFR. SLIGHT CHC -SHRA. MON...VFR. CHC MAINLY AFTERNOON -SHRA/-TSRA. TUE...VFR. NO SIG WX. && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITIES 25 TO 30 PERCENT FRIDAY AFTERNOON ACROSS THE MID HUDSON VALLEY REGION... WIND GUSTS OF 25-35 MPH POSSIBLE FRIDAY AFTERNOON IN THE MOHAWK VALLEY REGION...CAPITAL REGION...NORTHERN CATSKILLS...AND BERKSHIRES... A WEAK FRONT WILL MOVE ACROSS THE REGION THIS MORNING...AS HIGH PRESSURE WILL BUILD IN FROM THE WESTERN GREAT LAKES REGION THIS AFTERNOON WITH HOT...BREEZY...AND DRY WEATHER. ABOVE NORMAL TEMPERATURES WILL PERSIST DURING THE WEEKEND. AN UPPER LEVEL DISTURBANCE...AND A WEAK COOL FRONT MAY FOCUS SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON INTO THE EVENING. THE RH WILL FALL INTO THE 25-35 PERCENT RANGE IN THE VALLEYS...AND THE 35-50 PERCENT RANGE ACROSS THE HIGHER ELEVATIONS FRIDAY AFTERNOON. THE RH WILL HAVE AN EXCELLENT RECOVERY TO 80-100 PERCENT SATURDAY MORNING. DEW FORMATION IS LIKELY. THE RH VALUES WILL LOWER TO 25 TO 45 PERCENT ONCE AGAIN SATURDAY AFTERNOON. THE WINDS WILL VEER FROM THE SOUTH OR SOUTHWEST THIS MORNING...TO THE WEST BY THE AFTERNOON AT 10 TO 20 MPH...WITH SOME GUSTS IN THE 25 TO 35 MPH RANGE. THE WINDS WILL BECOME LIGHT AND VARIABLE AT 5 MPH OR LESS FRIDAY NIGHT. EXPECT WEST/SOUTHWEST WINDS OF 10 TO 20 MPH ON SATURDAY. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THE NEXT 5 DAYS. A WEAK FRONT WILL MOVE ACROSS THE HYDRO SERVICE AREA THIS MORNING WITH ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS. RAINFALL AMOUNTS WILL GENERALLY BE LIGHT WITH A FEW HUNDREDTHS TO A FEW TENTHS OF AN INCH. HIGH PRESSURE BRIEFLY BUILD THIS AFTERNOON THROUGH SATURDAY MORNING. ANOTHER WEAK COOL FRONT...AND AN UPPER LEVEL DISTURBANCE WILL BRING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON AND SATURDAY NIGHT. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE. CYCLONIC FLOW ALOFT MAY ALLOW ISOLATED SHOWERS...AND PERHAPS THUNDERSTORMS SUNDAY INTO EARLY NEXT WEEK. AGAIN...NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...WASULA NEAR TERM...WASULA SHORT TERM...WASULA LONG TERM...IAA AVIATION...IAA FIRE WEATHER...15 HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
145 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WEAK FRONTAL BOUNDARY WILL PASS THROUGH LATE TONIGHT INTO EARLY FRIDAY...TRIGGERING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. MUCH WARMER AIR WILL THEN SURGE INTO THE REGION FRIDAY AFTERNOON...LASTING THROUGH THE WEEKEND. ISOLATED TO SCATTERED...MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS COULD OCCUR SATURDAY WITH THE PASSAGE OF AN UPPER LEVEL DISTURBANCE...ESPECIALLY FOR AREAS SOUTH AND EAST OF ALBANY. && .NEAR TERM /THROUGH TODAY/... AS OF 115 AM EDT...MUDDLED SFC AND RADAR PICTURE THIS MORNING WITH WEAK WARM FRONT LIFTING N/NE FROM CNTRL NY AND PA ACROSS FCST AREA. SOME ISOLD SHOWERS HAVE FORMED OVER NRN NY AND THE TUG HILL PLATEAU. A FEW THUNDERSTORMS AHEAD OF THE WARM FRONT...AND MID LEVEL SHORT-WAVE HAVE DEVELOPED NORTH AND EAST OF ROCHESTER. FURTHER SOUTH AND WEST OVER NW PA...A CLUSTER OF CONVECTION HAS DEVELOPED AHEAD OF THE COOL FRONT OR WIND SHIFT BOUNDARY. THERE IS A LOT OF CLOUD TO GROUND LIGHTNING WITH THIS EVOLVING MCS. HOWEVER...IT IS MOVING E/SE. THIS CONVECTION MAY NEVER REACH OUR AREA. WE HAVE TRENDED MOST OF THE POPS TO SLIGHT CHC VALUES...EXCEPT CHANCE VALUES OVER THE SRN-WRN ADIRONDACKS. WE USED ISOLD SHOWERS/THUNDERSTORMS BTWN 06Z-12Z FROM WEST TO EAST. THE MID LEVEL LAPSES RATES DUE STEEPEN...AND THE SHOWALTER VALUES DO LOWER TO 0 TO -2C. SOME ELEVATED INSTABILITY IS IMPLIED. THE AIR MASS IS MORE STABLE IN THE ALY FCST AREA EASTWARD. TEMPS WILL STEADY IN THE LOWER TO MID 60S OVER MOST OF THE FCST AREA...WITH SOME U50S OVER THE MTNS...AND THE SHELTERED VALLEYS THAT COOLED QUICKLY BEFORE THE CONVECTIVE CLOUD DEBRIS MOVES IN. THE LATEST HRRR SHOWS SOME SHOWERS/ISOLD THUNDERSTORMS MOVING IN...AND OUT OF THE FCST AREA BY 12Z. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... FRIDAY...THE THREAT FOR SCATTERED CONVECTION WILL PERSIST THROUGH THE MID MORNING HOURS...BEFORE DIMINISHING FROM W TO E WITH THE PASSAGE OF THE SHORTWAVE. IN THE WAKE OF THIS WAVE...STRONG SUBSIDENCE SHOULD HELP DRIVE DRIER AIR INTO THE REGION FROM THE WEST...ALLOWING FOR A STRENGTHENING MID LEVEL CAP WHICH SHOULD INHIBIT FURTHER CONVECTION IN THE AFTERNOON. AMPLE AFTERNOON SUNSHINE SHOULD ALLOW MAX TEMPS TO REACH THE 90-95 IN VALLEY REGIONS...WARMEST ACROSS THE MID HUDSON VALLEY...AND 80S ACROSS HIGHER ELEVATIONS. FORTUNATELY...DECREASING DEW POINTS IN THE AFTERNOON SHOULD LIMIT HEAT INDICES TO THE MID AND UPPER 90S...SO NO HEAT ADVISORIES PLANNED. IT WILL BECOME RATHER BREEZY IN THE AFTERNOON...WITH SOME GUSTS POSSIBLY REACHING 30-35 MPH AT TIMES...ESP WITHIN CLOSE PROXIMITY TO THE MOHAWK RIVER VALLEY AND BERKSHIRES. FRIDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE SLIDES ACROSS FROM THE WEST...ALLOWING FOR MAINLY CLEAR SKIES. DIMINISHING WINDS AND SOMEWHAT DRIER AIR ALOFT SHOULD ALLOW TEMPS TO COOL RATHER SIGNIFICANTLY FROM DAYTIME MAXES...WITH 50S TO LOWER 60S IN MANY AREAS. SAT-SAT NT...SHOULD START OUT MOSTLY SUNNY. HOWEVER...THE COMBINATION OF ANOTHER MID LEVEL SHORTWAVE APPROACHING FROM THE WEST...AND SOME WEAK LOW/MID LEVEL THETA-E ADVECTION WILL INCREASE INSTABILITY IN THE AFTERNOON. AS THE WEAK SHORTWAVE PASSES SOUTH OF THE REGION...THERE MIGHT BE ENOUGH DYNAMICS IN PLACE TO PRODUCE ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS...ESP FROM ALBANY SOUTH AND EAST...WHERE SLIGHT CHC TO LOW CHC POPS ARE INDICATED. OTHERWISE...IT WOULD REMAIN QUITE WARM SATURDAY...WITH MAXES REACHING THE UPPER 80S TO LOWER 90S IN MOST VALLEYS...AND LOWER 80S ACROSS HIGHER ELEVATIONS. IN THE WAKE OF THE SHORTWAVE PASSAGE...SKIES SHOULD BECOME CLEAR TO PARTLY CLOUDY FOR SAT NT...WITH MINS FALLING INTO THE 50S TO LOWER 60S. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... BOTH THE 12 UTC ECMWF/GFS GENERALLY AGREE ON THE OVERALL PATTERN DURING THE EXTENDED PERIOD...WITH A LARGE UPPER RIDGE EXTENDING FROM THE GREAT PLAINS TOWARDS THE SOUTHEASTERN US. OUR REGION WILL BE ON THE NORTHEASTERN FRINGE OF THIS UPPER RIDGE AND FAST MOVING SHORTWAVE DIVING OUT OF CANADA WILL TRAVERSE ACROSS THE NORTHERN PORTION OF THE RIDGE AND ACROSS OUR REGION DURING THE UPCOMING WEEK. AT THIS POINT..THE LATEST RUNS OF THE ECMWF/GFS DON/T AGREE ON THE EXACT TIMING OF THESE INDIVIDUAL FEATURES. THE RESULT WILL BE A SLIGHT CHC/LOW CHC FOR SHRA/TSRA NEARLY EACH DAY...WITH THE BEST CHC DURING THE DIURNALLY FAVORED AFTN/EARLY EVE HOURS. DUE TO MODEL DIFFERENCES...IT/S DIFFICULT TO PINPOINT ANY PARTICULAR DAY WHERE THE THREAT IS GREATER/LOWER...BUT THIS SHOULD BE RESOLVED IN THE COMING DAYS AS MODELS BETTER FORECAST THESE INDIVIDUAL SHORTWAVES. THE WARM TEMPERATURES WILL BE IN PLACE TO START THE EXTENDED PERIOD...WITH UPPER 80S TO LOW 90S FOR VALLEY AREAS FOR SUNDAY. IT WILL BE FAIRLY MUGGY WITH DEWPOINTS IN THE MIDDLE 60S IN MANY VALLEY AREAS. TEMPS LOOK MORE SEASONABLE FOR MONDAY THROUGH THURSDAY...WITH LOW TO MID 80S FOR VALLEY AREAS...AND 70S FOR THE HIGHER TERRAIN AREAS FOR MAX TEMPS. MIN TEMPS WILL GENERALLY BE IN THE LOW TO MID 60S FOR VALLEY AREAS...AND 50S ACROSS THE HIGH TERRAIN. MUCH OF NEXT WEEK WILL BE MODERATELY HUMID...ALTHOUGH NOT OPPRESSIVE...WITH DEWPOINTS IN THE LOWER 60S FOR VALLEY AREAS...AND 50S FOR THE HIGH TERRAIN. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD...06Z/SATURDAY. THERE IS THE THREAT FOR ISOLATED CONVECTION EARLY THIS MORNING AS A WEAK WARM FRONT MOVES ACROSS THE REGION ALONG WITH A MID LEVEL SHORT WAVE. DO NOT HAVE THE CONFIDENCE TO PUT CONVECTION IN TAF. THE WINDOW FOR IT TO OCCUR IS 08Z-13Z. MVFR CONDITIONS ARE POSSIBLE WITH ANY CONVECTION. CLOUD COVER WILL DECREASE TODAY AND WINDS WILL BECOME WESTERLY AND INCREASE TO 12 TO 18 KNOTS WITH GUSTS IN THE 20S WITH THE STRONGEST WINDS AT KALB. THE WINDS WILL DIMINISH THIS EVENING. OUTLOOK... SAT-TUE...VFR. ISOLATED TO SCATTERED MAINLY AFTERNOON -SHRA/-TSRA WITH MVFR POSSIBLE. && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITY VALUES OF 25-30 PERCENT FRI AFTERNOON ACROSS THE MID HUDSON VALLEY REGION... WIND GUSTS OF 25-35 MPH POSSIBLE FRI AFTERNOON WITHIN THE MOHAWK VALLEY REGION AND BERKSHIRES... A WEAK FRONTAL SYSTEM MAY TRIGGER ISOLATED TO SCATTERED THUNDERSTORMS LATE TONIGHT INTO FRIDAY MORNING. MUCH WARMER AIR WILL SWEEP INTO THE REGION FOR FRIDAY AFTERNOON THROUGH SUNDAY IN THE WAKE OF THIS FRONT. THE RH WILL RECOVER TO 90-100 PERCENT TONIGHT...THEN FALL INTO THE 25-35 PERCENT RANGE IN VALLEYS...AND 35-45 PERCENT RANGE ACROSS HIGHER ELEVATIONS FRI AFTERNOON. THE RH WILL RECOVER TO 80-100 PERCENT FOR FRI NT...WITH SOME DEW FORMATION POSSIBLE. WINDS WILL BECOME SOUTHWEST TO SOUTH...AT 5-10 MPH TONIGHT. THE WINDS WILL SHIFT INTO THE WEST BY FRIDAY AFTERNOON...AND INCREASE TO 15 TO 25 MPH...WITH SOME GUSTS POSSIBLY REACHING 30-35 MPH...MAINLY ACROSS THE MOHAWK RIVER VALLEY AND BERKSHIRES. WINDS WILL QUICKLY DIMINISH AFTER SUNSET FRIDAY...AND DECREASE TO 5-10 MPH. WINDS MAY BE MUCH STRONGER...AND VARIABLE IN DIRECTION IN AND NEAR ANY THUNDERSTORMS LATE TONIGHT INTO FRIDAY MORNING. && .HYDROLOGY... NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH AT LEAST THE NEXT FIVE DAYS. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE TONIGHT INTO FRIDAY MORNING...AS A VERY WARM AIR MASS MOVES IN. SOME BRIEF HEAVY DOWNPOURS WILL BE POSSIBLE IN ANY THUNDERSTORMS...BUT BASIN AVERAGE AMOUNTS WILL BE LIGHT DUE TO EXPECTED LIMITED AREAL COVERAGE. DRIER WEATHER WILL RETURN FOR FRIDAY AFTERNOON THROUGH AT LEAST SATURDAY MORNING. THEN...ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON INTO EARLY EVENING SATURDAY AND SUNDAY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL/WASULA NEAR TERM...WASULA SHORT TERM...KL LONG TERM...FRUGIS AVIATION...IAA FIRE WEATHER...KL HYDROLOGY...KL/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
122 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WEAK FRONTAL BOUNDARY WILL PASS THROUGH LATE TONIGHT INTO EARLY FRIDAY...TRIGGERING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. MUCH WARMER AIR WILL THEN SURGE INTO THE REGION FRIDAY AFTERNOON...LASTING THROUGH THE WEEKEND. ISOLATED TO SCATTERED...MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS COULD OCCUR SATURDAY WITH THE PASSAGE OF AN UPPER LEVEL DISTURBANCE...ESPECIALLY FOR AREAS SOUTH AND EAST OF ALBANY. && .NEAR TERM /THROUGH TODAY/... AS OF 115 AM EDT...MUDDLED SFC AND RADAR PICTURE THIS MORNING WITH WEAK WARM FRONT LIFTING N/NE FROM CNTRL NY AND PA ACROSS FCST AREA. SOME ISOLD SHOWERS HAVE FORMED OVER NRN NY AND THE TUG HILL PLATEAU. A FEW THUNDERSTORMS AHEAD OF THE WARM FRONT...AND MID LEVEL SHORT-WAVE HAVE DEVELOPED NORTH AND EAST OF ROCHESTER. FURTHER SOUTH AND WEST OVER NW PA...A CLUSTER OF CONVECTION HAS DEVELOPED AHEAD OF THE COOL FRONT OR WIND SHIFT BOUNDARY. THERE IS A LOT OF CLOUD TO GROUND LIGHTNING WITH THIS EVOLVING MCS. HOWEVER...IT IS MOVING E/SE. THIS CONVECTION MAY NEVER REACH OUR AREA. WE HAVE TRENDED MOST OF THE POPS TO SLIGHT CHC VALUES...EXCEPT CHANCE VALUES OVER THE SRN-WRN ADIRONDACKS. WE USED ISOLD SHOWERS/THUNDERSTORMS BTWN 06Z-12Z FROM WEST TO EAST. THE MID LEVEL LAPSES RATES DUE STEEPEN...AND THE SHOWALTER VALUES DO LOWER TO 0 TO -2C. SOME ELEVATED INSTABILITY IS IMPLIED. THE AIR MASS IS MORE STABLE IN THE ALY FCST AREA EASTWARD. TEMPS WILL STEADY IN THE LOWER TO MID 60S OVER MOST OF THE FCST AREA...WITH SOME U50S OVER THE MTNS...AND THE SHELTERED VALLEYS THAT COOLED QUICKLY BEFORE THE CONVECTIVE CLOUD DEBRIS MOVES IN. THE LATEST HRRR SHOWS SOME SHOWERS/ISOLD THUNDERSTORMS MOVING IN...AND OUT OF THE FCST AREA BY 12Z. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... FRIDAY...THE THREAT FOR SCATTERED CONVECTION WILL PERSIST THROUGH THE MID MORNING HOURS...BEFORE DIMINISHING FROM W TO E WITH THE PASSAGE OF THE SHORTWAVE. IN THE WAKE OF THIS WAVE...STRONG SUBSIDENCE SHOULD HELP DRIVE DRIER AIR INTO THE REGION FROM THE WEST...ALLOWING FOR A STRENGTHENING MID LEVEL CAP WHICH SHOULD INHIBIT FURTHER CONVECTION IN THE AFTERNOON. AMPLE AFTERNOON SUNSHINE SHOULD ALLOW MAX TEMPS TO REACH THE 90-95 IN VALLEY REGIONS...WARMEST ACROSS THE MID HUDSON VALLEY...AND 80S ACROSS HIGHER ELEVATIONS. FORTUNATELY...DECREASING DEW POINTS IN THE AFTERNOON SHOULD LIMIT HEAT INDICES TO THE MID AND UPPER 90S...SO NO HEAT ADVISORIES PLANNED. IT WILL BECOME RATHER BREEZY IN THE AFTERNOON...WITH SOME GUSTS POSSIBLY REACHING 30-35 MPH AT TIMES...ESP WITHIN CLOSE PROXIMITY TO THE MOHAWK RIVER VALLEY AND BERKSHIRES. FRIDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE SLIDES ACROSS FROM THE WEST...ALLOWING FOR MAINLY CLEAR SKIES. DIMINISHING WINDS AND SOMEWHAT DRIER AIR ALOFT SHOULD ALLOW TEMPS TO COOL RATHER SIGNIFICANTLY FROM DAYTIME MAXES...WITH 50S TO LOWER 60S IN MANY AREAS. SAT-SAT NT...SHOULD START OUT MOSTLY SUNNY. HOWEVER...THE COMBINATION OF ANOTHER MID LEVEL SHORTWAVE APPROACHING FROM THE WEST...AND SOME WEAK LOW/MID LEVEL THETA-E ADVECTION WILL INCREASE INSTABILITY IN THE AFTERNOON. AS THE WEAK SHORTWAVE PASSES SOUTH OF THE REGION...THERE MIGHT BE ENOUGH DYNAMICS IN PLACE TO PRODUCE ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS...ESP FROM ALBANY SOUTH AND EAST...WHERE SLIGHT CHC TO LOW CHC POPS ARE INDICATED. OTHERWISE...IT WOULD REMAIN QUITE WARM SATURDAY...WITH MAXES REACHING THE UPPER 80S TO LOWER 90S IN MOST VALLEYS...AND LOWER 80S ACROSS HIGHER ELEVATIONS. IN THE WAKE OF THE SHORTWAVE PASSAGE...SKIES SHOULD BECOME CLEAR TO PARTLY CLOUDY FOR SAT NT...WITH MINS FALLING INTO THE 50S TO LOWER 60S. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... BOTH THE 12 UTC ECMWF/GFS GENERALLY AGREE ON THE OVERALL PATTERN DURING THE EXTENDED PERIOD...WITH A LARGE UPPER RIDGE EXTENDING FROM THE GREAT PLAINS TOWARDS THE SOUTHEASTERN US. OUR REGION WILL BE ON THE NORTHEASTERN FRINGE OF THIS UPPER RIDGE AND FAST MOVING SHORTWAVE DIVING OUT OF CANADA WILL TRAVERSE ACROSS THE NORTHERN PORTION OF THE RIDGE AND ACROSS OUR REGION DURING THE UPCOMING WEEK. AT THIS POINT..THE LATEST RUNS OF THE ECMWF/GFS DON/T AGREE ON THE EXACT TIMING OF THESE INDIVIDUAL FEATURES. THE RESULT WILL BE A SLIGHT CHC/LOW CHC FOR SHRA/TSRA NEARLY EACH DAY...WITH THE BEST CHC DURING THE DIURNALLY FAVORED AFTN/EARLY EVE HOURS. DUE TO MODEL DIFFERENCES...IT/S DIFFICULT TO PINPOINT ANY PARTICULAR DAY WHERE THE THREAT IS GREATER/LOWER...BUT THIS SHOULD BE RESOLVED IN THE COMING DAYS AS MODELS BETTER FORECAST THESE INDIVIDUAL SHORTWAVES. THE WARM TEMPERATURES WILL BE IN PLACE TO START THE EXTENDED PERIOD...WITH UPPER 80S TO LOW 90S FOR VALLEY AREAS FOR SUNDAY. IT WILL BE FAIRLY MUGGY WITH DEWPOINTS IN THE MIDDLE 60S IN MANY VALLEY AREAS. TEMPS LOOK MORE SEASONABLE FOR MONDAY THROUGH THURSDAY...WITH LOW TO MID 80S FOR VALLEY AREAS...AND 70S FOR THE HIGHER TERRAIN AREAS FOR MAX TEMPS. MIN TEMPS WILL GENERALLY BE IN THE LOW TO MID 60S FOR VALLEY AREAS...AND 50S ACROSS THE HIGH TERRAIN. MUCH OF NEXT WEEK WILL BE MODERATELY HUMID...ALTHOUGH NOT OPPRESSIVE...WITH DEWPOINTS IN THE LOWER 60S FOR VALLEY AREAS...AND 50S FOR THE HIGH TERRAIN. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/... MAINLY VFR CONDITIONS WILL PREVAIL AT THE KGFL/KALB/KPOU/KPSF TAF SITES THROUGH THE TAF PERIOD ENDING AT 00Z SATURDAY. THE ONLY THREAT FOR NON VFR CONDITIONS WILL COME LATE TONIGHT/EARLY SATURDAY MORNING AS A FRONTAL BOUNDARY CROSSES THE REGION HAVE LEFT THE PROB30 GROUP FOR CONVECTION AT ALL THE TAF SITES FOR THAT TIME PERIOD (GENERALLY BETWEEN 09Z AND 13Z). LIGHT AND VARIABLE WINDS THIS EVENING AND OVERNIGHT AHEAD OF THE FRONTAL BOUNDARY. AFTER THE FRONTAL BOUNDARY MOVES THROUGH FRIDAY MORNING...WESTERLY WINDS WILL INCREASE TO 12 TO 15 KTS WITH GUSTS OF 20 TO 25 KTS EXPECTED. OUTLOOK... FRI NIGHT...VFR. NO SIG WX. SAT-SAT NT...VFR/MVFR. ISOLATED TO SCATTERED AFTERNOON -SHRA/-TSRA. SUN-TUE...VFR/MVFR. SLIGHT CHC TO CHC MAINLY AFTERNOON -SHRA/-TSRA. && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITY VALUES OF 25-30 PERCENT FRI AFTERNOON ACROSS THE MID HUDSON VALLEY REGION... WIND GUSTS OF 25-35 MPH POSSIBLE FRI AFTERNOON WITHIN THE MOHAWK VALLEY REGION AND BERKSHIRES... A WEAK FRONTAL SYSTEM MAY TRIGGER ISOLATED TO SCATTERED THUNDERSTORMS LATE TONIGHT INTO FRIDAY MORNING. MUCH WARMER AIR WILL SWEEP INTO THE REGION FOR FRIDAY AFTERNOON THROUGH SUNDAY IN THE WAKE OF THIS FRONT. THE RH WIL RECOVER TO 90-100 PERCENT TONIGHT...THEN FALL INTO THE 25-35 PERCENT RANGE IN VALLEYS...AND 35-45 PERCENT RANGE ACROSS HIGHER ELEVATIONS FRI AFTERNOON. THE RH WILL RECOVER TO 80-100 PERCENT FOR FRI NT...WITH SOME DEW FORMATION POSSIBLE. WINDS WILL BECOME SOUTHWEST TO SOUTH...AT 5-10 MPH TONIGHT. THE WINDS WILL SHIFT INTO THE WEST BY FRIDAY AFTERNOON...AND INCREASE TO 15 TO 25 MPH...WITH SOME GUSTS POSSIBLY REACHING 30-35 MPH...MAINLY ACROSS THE MOHAWK RIVER VALLEY AND BERKSHIRES. WINDS WILL QUICKLY DIMINISH AFTER SUNSET FRIDAY...AND DECREASE TO 5-10 MPH. WINDS MAY BE MUCH STRONGER...AND VARIABLE IN DIRECTION IN AND NEAR ANY THUNDERSTORMS LATE TONIGHT INTO FRIDAY MORNING. && .HYDROLOGY... NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH AT LEAST THE NEXT FIVE DAYS. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE TONIGHT INTO FRIDAY MORNING...AS A VERY WARM AIR MASS MOVES IN. SOME BRIEF HEAVY DOWNPOURS WILL BE POSSIBLE IN ANY THUNDERSTORMS...BUT BASIN AVERAGE AMOUNTS WILL BE LIGHT DUE TO EXPECTED LIMITED AREAL COVERAGE. DRIER WEATHER WILL RETURN FOR FRIDAY AFTERNOON THROUGH AT LEAST SATURDAY MORNING. THEN...ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON INTO EARLY EVENING SATURDAY AND SUNDAY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL/WASULA NEAR TERM...WASULA SHORT TERM...KL LONG TERM...FRUGIS AVIATION...GJM FIRE WEATHER...KL HYDROLOGY...KL/JPV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
335 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WARM FRONT WILL CROSS OUR AREA THIS MORNING. MEANWHILE, HIGH PRESSURE ACROSS THE SOUTHERN STATES WILL GENERALLY REMAIN IN PLACE THROUGH SUNDAY. A COOL FRONT WILL GRADUALLY SETTLE SOUTHEASTWARD ACROSS THE AREA SATURDAY INTO SUNDAY, HOWEVER IT WILL TEND TO STALL ACROSS THE NORTHERN MID ATLANTIC REGION MONDAY AND TUESDAY. THIS FRONT MAY THEN LIFT NORTHEASTWARD AS A WARM FRONT WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO CHANGES TO HEAT RELATED HEADLINES. THE WRF-NMMB AND GFS INITIALIZATION WERE ABOUT THE SAME THIS MORNING VS THE 00Z SOUNDING AND LOOKED MUCH BETTER AT 925MB NOW THAT THE CORE OF THE HOT AIR MASS IS FARTHER TO THE EAST AND A LITTLE HIGHER ABOVE THE SURFACE. THE ECMWF CONTINUES TO VERIFY 1-3C TOO WARM, MAKE THAT HOT, WITH ITS 12HR 925MB FORECAST IN THE CENTRAL CONUS. LAST NIGHT WE WERE WONDERING IF THE MCS WOULD HEAD NORTH (KINEMATICS) OR SOUTH (THERMODYNAMICS). IN REALITY ITS LOOKING LIKE NEITHER AS IT MOVES AWAY FROM ITS SURFACE BASED INFLOW, THE THUNDERSTORM CLUSTER IS FOLLOWING MORE THE 700MB FLOW AND THUS HIEST CHANCES EARLY ARE CENTRAL. THE LATEST HRRR HAS A PRETTY GOOD HANDLE ON IT AS TO WHERE, EVEN IF ITS GEOGRAPHIC EXTENT IS A BIT TOO MUCH. IMPRESSIVE BOW ECHO MOVING THROUGH STATE COLLEGE AREA, WE DID CARRY SOME EARLY ENHANCED WORDING WEST. AT ONE TIME THIS CLUSTER HAD ABOUT 1500 CG LTGNG STRIKES IN 15 MINUTES. AFTER THIS SYSTEM OR WHAT IS LEFT OF IT MOVES THROUGH EARLY THIS MORNING, MODEL FORECAST SOUNDINGS DEVELOP A CAP AND CONSIDERABLE CIN THAT SHOULD NEGATE ANY ADDITIONAL CONVECTIVE POTENTIAL FOR THE REST OF THE DAY. BASED ON THE GFS AND NAM MOS PERFORMANCE TO OUR WEST, WE WENT WITH A STAT GUIDANCE COMPROMISE. FOR PHL THE 00Z SAT FCST 1000-850MB GFS FCST THICKNESS PRETTY MUCH MATCHES 100F TO OUR WEST. BECAUSE OF THE CLOUDINESS DEBRIS EARLY, WE DID SLOW THE RISE OF TEMPS A BIT THIS MORNING, BUT GIVEN THE DAYS DO NOT GET MUCH LONGER THAN NOW, WE DO NOT BELIEVE THEY WILL PUT A DENT IN OUR MAX TEMP POTENTIAL. DEW POINTS ON THE OTHER HAND ARE MORE OF A CONUNDRUM. THE FLOW IS FORECAST TO BE NORTHWEST TO WEST AT THE SURFACE, USUALLY A DRYING DIRECTION. BUT THE DEW POINTS TO OUR WEST ARE HIGHER. THE GFS MODEL SFC DEW POINT PROGS YESTERDAY AFTN WERE 10F TOO HIGH, APPLYING THE SAME CORRECTION TODAY, GIVES US MOST AFTERNOON DEW POINTS IN THE 60S, NOT THAT FAR FROM CURRENT STAT GUIDANCE. THUS THE CURRENT ADVISORIES AND WARNINGS LOOK GOOD. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... ANOTHER VERY WARM NIGHT FOR OUR CWA. A WEAK FRONT WILL TRY TO SAG SOUTH INTO OUR CWA WITH NOT MUCH COOLING EFFECT EXPECTED. THE MESOSCALE MODELING IS PASSING ANOTHER REMNANT OF A MCS ACROSS THE SOUTHERN PARTS OF OUR CWA LATE. JUST LIKE TONIGHT, IT WILL AT THE LEAST BE UNSTABLE ENOUGH ALOFT TO SUPPORT ONGOING CONVECTION, SO LOW POPS WERE STARTED. FOR MIN TEMPS, A STAT GUIDANCE COMPROMISE WAS FOLLOWED. && .LONG TERM /SATURDAY THROUGH THURSDAY/... THE HEAT AND HUMIDITY WILL CONTINUE TO BE IN PLACE DURING THE WEEKEND AND POSSIBLY INTO MONDAY AS HIGH PRESSURE ALOFT REMAINS OVER THE SOUTHEAST U.S. TEMPERATURES WILL REMAIN ABOVE NORMAL WITH WIDESPREAD 90S IN MOST AREAS. SCATTERED SHOWERS/TSTMS DAILY FAVORING THE AFTERNOON AND EARLY EVENING WITH MOSTLY SLGT CHC OR LOW CHC POPS. SPC HAS PLACED MUCH OF OUR AREA IN SLGT CHC FOR SVR ON DAY2 (12Z SAT - 12Z SUN). UNSETTLED CONDITIONS REMAIN INTO THE MIDDLE OF NEXT WEEK WITH THE HIGH ALOFT RE-BUILDING BACK ACROSS THE WRN PART OF THE COUNTY AND A TROUGH DIGGING ACROSS ERN CANADA AND THE NORTHEAST STATES. THIS WILL BRING AN END TO THE EXCESSIVELY HOT CONDITIONS...WITH READINGS RETURNING BACK CLOSER TO NORMAL. DAILY SCT SHOWERS/TSTMS MON-WED IN THE GRIDS ATTM WITH LOW CONFID IN TIMING/PLACEMENT OF ANY CONVECTION. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE 06Z TAFS ARE GIVING THE HIGHEST CHANCES OF THUNDER MAKING IT INTO THE KPHL, KILG AND KRDG TERMINALS TOWARD MORNING WITH NEAR OR MVFR CONDITIONS. WE WILL AMEND AND ADD CHANCE TO KABE, KTTN AND KPNE TO THE MIX. IMPRESSIVE SMALL COMPLEX OF TSTMS IN NWRN PA IS PRODUCING AROUND 500 CLOUD TO GROUND LIGHTNING STRIKES EVERY 5 MINUTES AT ITS PEAK EARLIER. THE AIR MASS IS NOT AS UNSTABLE ON OUR SIDE OF THE APPALACHIANS, SO WE WILL MONITOR ITS PROGRESS. LESS CONFIDENCE ABOUT THE TSTMS MAKING IT INTO THE OTHER TERMINALS IF AT ALL, SO WILL NOT BE INCLUDED. ONCE THIS CLUSTER MOVES THROUGH, WE ARE EXPECTING VFR CONDITIONS FORM THE REST OF THE TAF PERIOD. IN FACT, AS HARD AS IT IS TO FATHOM, WE MAY NOT REACH THE CONVECTIVE TEMPERATURE TODAY, SO HARDLY ANY CUMULUS CLOUDS ARE FORECAST. WEST WINDS SHOULD AVERAGE AROUND 10 TO 15 KTS AND KEEP THE SEA BREEZE FRONT EAST OF ALL OUR NJ TERMINALS. FORECAST SOUNDINGS ARE NOT SHOWING MUCH GUSTINESS. FOR THIS EVENING, NO SIGNIFICANT CLOUDS ARE EXPECTED OR VSBY RESTRICTIONS FOR ANY OF OUR TERMINALS. WINDS SHOULD BECOME LIGHTER AND GENERALLY FROM THE NORTHWEST. OUTLOOK... MOSTLY VFR CONDITIONS EXPECTED OVER THE TERMINALS. DAYTIME HZ AND PATCHY OVERNIGHT FOG MAY BRING SOME LOWER VSBYS AT TIMES. SCT SHOWERS/TSTMS ARE POSSIBLE DURING (MAINLY) THE AFTERNOON AND EARLY EVENING. LOWER CIGS/VSBYS DURING TSTMS. && .MARINE... CONDITIONS ON OUR WATERS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH FRIDAY NIGHT. WINDS WILL PRIMARILY BE SOUTHWESTERLY TODAY AND GO WEST FOR A WHILE TONIGHT AS THAT WEAK FRONT BACKS INTO OUR AREA. OUTLOOK... SUB-SCA CONDITIONS OVER THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK. SEAS ON THE OCEAN WILL BE MOSTLY IN THE 2-4 FT RANGE. SCT TSTMS WITH LOCALLY GUSTY WINDS AND HIGHER SEAS WILL BE THE GREATEST HAZARD ON THE WATERS. && .TIDES/COASTAL FLOODING... GFS ETSS STILL MODELS POTENTIAL MINOR COASTAL FLOOD EPISODES HERE WITH THE EVENING TIDE CYCLES BEGINNING SUNDAY OR MONDAY AND CONTG THRU AT LEAST JULY 3 FULL MOON WHEN ASTRO TIDE IS WITHIN .3 FT OF THE MINOR TIDAL INUNDATION THRESHOLD. && .FIRE WEATHER... LIKE YESTERDAY, MEAN RH(S) ARE EXPECTED TO DROP CLOSE TO 30 PERCENT THIS AFTERNOON AND ALSO LIKE YESTERDAY, OVERALL WINDS ARE EXPECTED TO FALL SHORT OF RED FLAG CRITERIA. WE WILL MAKE MENTION IN THE FIRE WEATHER FORECAST. && .RIP CURRENTS... WHILE THE RISK OF DANGEROUS RIP CURRENTS APPEARS LOW FOR THE NEXT SEVERAL DAYS, THERE SHOULD BE SOME ENHANCEMENT OF THE RISK FOR RIP CURRENTS. FIRST ASSOCIATED WITH AN INCREASING S SWELL TO 3 FEET WITH A 8 SECOND PERIOD TODAY THAT CONTINUES INTO SATURDAY...ESPECIALLY IF THE WIND AT BUOY 009 IS 180 OR 190 DEGREES, AND THEN WITH AN INCREASINGLY LARGE RATE OF CHANGE IN TIDES AS WE MOVE TOWARD THE FULL MOON EARLY NEXT WEEK. && .CLIMATE... TEMPERATURES ARE EXPECTED TO REACH WELL INTO THE 90S FRIDAY THROUGH SUNDAY. BELOW ARE THE RECORD HIGH TEMPERATURES AND MOST RECENT YEAR OF OCCURRENCE FOR JUNE 29 THROUGH JULY 1 FOR OUR EIGHT CLIMATE SITES. JUNE 29 JUNE 30 JULY 1 PHL 102 - 1934 100 - 1964 102 - 1901 ACY 98 - 1991 98 - 1991 99 - 1968 ILG 98 - 1959 98 - 1964 97 - 1963 ABE 99 - 1934 97 - 1964 97 - 1963 TTN 100 - 1934 98 - 1964 98 - 1945 RDG 99 - 1943 98 - 1964 101 - 1901 GED 99 - 1969 101 - 1959 98 - 1964 MPO 89 - 1944 90 - 1964 88 - 1968 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR PAZ060>062. EXCESSIVE HEAT WARNING FROM NOON TODAY TO 8 PM EDT SUNDAY FOR PAZ067>071. NJ...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR NJZ007>010-012-013-016-020>023-027. EXCESSIVE HEAT WARNING FROM NOON TODAY TO 8 PM EDT SUNDAY FOR NJZ015-017>019. DE...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR DEZ002-003. EXCESSIVE HEAT WARNING FROM NOON TODAY TO 8 PM EDT SUNDAY FOR DEZ001. MD...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR MDZ008-012-015-019-020. MARINE...NONE. && $$ SYNOPSIS...GORSE NEAR TERM...GIGI SHORT TERM...GIGI LONG TERM...O`HARA AVIATION...GIGI MARINE...GIGI TIDES/COASTAL FLOODING...GIGI RIP CURRENTS...DRAG CLIMATE...KLINE
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
103 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WARM FRONT WILL CROSS OUR AREA FRIDAY MORNING. MEANWHILE, HIGH PRESSURE ACROSS THE SOUTHERN STATES WILL GENERALLY REMAIN IN PLACE THROUGH SUNDAY. A COOL FRONT WILL GRADUALLY SETTLE SOUTHEASTWARD ACROSS THE AREA SATURDAY INTO SUNDAY, HOWEVER IT WILL TEND TO STALL ACROSS THE NORTHERN MID ATLANTIC REGION MONDAY AND TUESDAY. THIS FRONT MAY THEN LIFT NORTHEASTWARD AS A WARM FRONT WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... SHORT TERM UPDATE INCORPORATING LATEST HRRR ALONG WITH THE 00Z WRF-NMMB THERMODYNAMIC PROFILE FOR FINE TUNING, BASICALLY LOOKS LIKE THE THERMODYNAMICS WIN OVER THE KINEMATICS WITH POPS ADJUSTED LOWER TOWARD NYC AND HIER SWRN PART OF OUR CWA. SMALL MCS TAPPING THE STILL WELL IN THE 80S AND UPPER 60S DEW POINTS IN OHIO AND HAS STRENGTHENED. WHILE THERE IS SUSTAINABILITY ALOFT, ITS GOING TO BE OUTRUNNING THE BEST SURFACE BASED INSTABILITY SHORTLY. THE FCST THETA E AND THERMODYNAMIC FEED SUGGEST MORE OF A SHARPER TURN TO THE RIGHT. OTHERWISE DOWN THE ROAD THE HRRR AND NMM INFERRING OUR ENVIRONMENT JUST NOT AS HOSPITABLE HERE. REGARDLESS ENOUGH OF A SHORT WAVE TO KEEP CHANCES GOING, WILL MONITOR THE NEXT COUPLE OF HRS TO SEE IF WE HAVE TO ADD ANY ENHANCED WORDING. TEMPS AND DEW POINTS REMAIN ON OR CLOSE TO SCHEDULE. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... TSTMS MOVE OUT TO SEA BY 12 OR 13Z AND THEN THE DANGEROUS HEAT INDICES. FRIDAY WILL FEEL DRAMATICALLY DIFFERENT THAN TODAY AND I THINK BE THE WORST ITS FELT HERE SO FAR THIS SUMMER. NEAR RECORD HEAT...WITHIN 2F OF RECORD POSSIBLE BY 530 PM... TEMPERATURES TO SOAR WELL INTO THE 90S FOR MOST AREAS. DEWPOINTS WELL INTO THE 60S AND PERHAPS LOW 70S FOR SOUTHERN AREAS WILL MAKE FOR A VERY MUGGY DAY. THERE IS SOME CONCERN, HOWEVER, THAT DEWPOINTS MAY MIX OUT AND LOWER SOMEWHAT LATER IN THE AFTERNOON. WE DO HOWEVER EXPECT TO REACH OUR HEAT INDEX CRITERIA, AND THUS, THE EXCESSIVE HEAT WARNING IS MAINTAINED FOR PHILADELPHIA AND ITS SURROUNDING COUNTIES. WE HAVE ALSO ISSUED A HEAT ADVISORY FOR MOST OF THE REMAINDER OF OUR FORECAST AREA WITH THE AFTERNOON PACKAGE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE HEAT WAVE THROUGH AT LEAST MIDWEEK FOR A GOOD PART OF THE REGION MAY BE TEMPORARILY INTERRUPTED BY LOCAL CONVECTION AT TIMES. SYNOPTICALLY, AN ELONGATED RIDGE IS FORECAST TO GENERALLY REMAIN IN PLACE FROM THE CENTRAL PLAINS TO THE SOUTHEASTERN UNITED STATES. TO THE NORTH OF THIS, SOME TROUGHING IS MAINTAINED ACROSS EASTERN CANADA WITH THIS FEATURE TRYING TO AMPLIFY SOME ACROSS THE NORTHEAST. THIS SYNOPTIC SETUP RESULTS IN A NORTHWESTERLY FLOW ALOFT ACROSS THE NORTHEAST AND MID ATLANTIC REGION. THEREFORE, SOME EMBEDDED WEAKER SHORT WAVES AND SURFACE FRONTAL BOUNDARIES WILL BE MOVING ACROSS THE AREA. OUR SENSIBLE WEATHER WILL REMAIN HOT AND GENERALLY HUMID THROUGH SUNDAY, BUT THEN THE TROUGH AMPLIFIES SOME AND THIS SHOULD KNOCK DOWN THE EXCESSIVE HEAT. A FRONTAL BOUNDARY LURKING AROUND THE NORTHERN MID ATLANTIC REGION MAY TRY AND LIFT NORTHEASTWARD SOME WEDNESDAY INTO THURSDAY. THE FORECAST CHALLENGES INCLUDE THE CONTINUATION OF THE HEAT FOR A TIME, THE DEW POINTS, AND CONVECTIVE CHANCES. WE GENERALLY TOOK A MODEL BLEND FRIDAY NIGHT INTO SUNDAY, THEN SWITCHED TO HPC GUIDANCE THEREAFTER WITH SOME TWEAKS BASED ON ADDITIONAL COLLABORATION. HPC WENT WITH THE GFS ENSEMBLE MEANS SUNDAY NIGHT THROUGH TUESDAY THEN A GFS/ECMWF ENSEMBLE MEANS BLEND WEDNESDAY AND THURSDAY. FOR FRIDAY NIGHT THROUGH SUNDAY, THE HEAT WILL BE ON DURING THIS TIME FRAME. THERE IS STILL A CONCERN THAT THE SURFACE DEW POINTS ARE ABLE TO MIX OUT SOME SATURDAY AND SUNDAY AFTERNOONS AS THE BOUNDARY LAYER WILL BE RATHER HOT WITH DRIER AIR ABOVE. THERE ARE SOME QUESTIONS WHICH INCLUDE WHERE A WEAK SURFACE BOUNDARY BECOMES ESTABLISHED AND CONVECTIVE CHCS. THE TEMPERATURE FORECAST AT 925 MB ARE AROUND +25C, WITH THE MAIN HEAT CORE FROM ABOUT VIRGINIA ON SOUTH AND WESTWARD. THE LOW-LEVEL FLOW LOOKS TO SHIFT MORE FROM THE SOUTHWEST AT TIMES, AND THIS TYPICALLY WOULD FAVOR HIGHER DEW POINTS. AN EXAMINATION OF SOME FORECAST SOUNDINGS SHOW AS THE BOUNDARY LAYER BECOMES RATHER HOT, ENOUGH MIXING FROM ABOVE OCCURS TO LOWER THE SURFACE DEW POINTS. WE DO ANTICIPATE THE DEW POINTS TO MIX OUT AT LEAST SOME, AND THIS WILL TEND TO KEEP THE HEAT INDICES MORE IN CHECK. DESPITE THIS, IT WILL STILL BE RATHER HOT. OUR DEW POINT FORECAST IS MORE OF A MODEL MOS BLEND AS THIS MESHES BETTER WITH REGIONAL SOUNDINGS. REGARDING HEADLINES, THE WARNING WILL CONTINUE THROUGH 00Z MONDAY FOR THE PHILADELPHIA METRO AREA AS THE HEAT INDEX CRITERIA IS LOWER. ELSEWHERE, WE DECIDED TO HOLD OFF ON A HEAT ADVISORY AS FORECAST DEW POINTS ARE KEEPING THE HEAT INDICES UNDER CRITERIA. THIS WILL BE REVISITED IN LATER FORECASTS. THE FLOW AROUND 925 MB IS FORECAST TO BE GENERALLY WESTERLY AT ABOUT 10 TO 15 KNOTS, THEREFORE ANY SEA BREEZE SHOULD STAY CLOSE TO THE COAST. REGARDING THE CONVECTIVE POTENTIAL, GIVEN THE FLOW IN THE MID AND UPPER LEVELS IN COMBINATION WITH A HOT AIRMASS, THERE COULD BE A TENDENCY FOR SOME CAPPING ESPECIALLY AT NIGHT. ANY IMPULSES EMBEDDED WITHIN THIS FLOW REGION AND ALONG THE NORTHERN PERIPHERY OF THE ELONGATED RIDGE SHOULD BE ABLE TO INITIATE SOME CONVECTION WITH DECENT INSTABILITY IN PLACE. THE GUIDANCE CONTINUES TO HINT AT SOME CONVECTION ARRIVING SATURDAY INTO SUNDAY, HOWEVER IT IS NOT CLEAR IF THIS IS COMPLETELY SURFACE BASED AS THE MCS THE 12Z NAM SUGGESTS LOOKS MORE ELEVATED BASED ON ITS FORECAST SOUNDINGS SATURDAY NIGHT. THE TIMING/STRENGTH OF ANY IMPULSE ALONG WITH A LINGERING SURFACE BOUNDARY AND HOW IT MAY PLAY A ROLE CARRIES SOME UNCERTAINTY, AND ANY MORE ORGANIZED CONVECTION WILL ALSO HAVE AN IMPACT ON THE HEAT /I.E. DEBRIS CLOUDINESS AND DEW POINT INFLUENCES/. THE GFS HAS HAD A TENDENCY TO BE MORE AGGRESSIVE WITH THE HIGHER SURFACE DEW POINTS /MOS IS LOWER/, THEREFORE THIS MAY HELP TO EXPLAIN MORE CONVECTIVE OPPORTUNITIES INDICATED BY THIS MODEL AT TIMES. FOR NOW, SOME SLIGHT CHC TO LOW CHC POPS WERE CARRIED DURING PORTIONS OF THIS TIME FRAME. FOR MONDAY AND TUESDAY, A TROUGH ACROSS EASTERN CANADA AMPLIFIES A BIT INTO THE NORTHEAST. THIS ALLOWS HEIGHTS TO START LOWERING AND THE EXCESSIVE HEAT SHOULD BACK DOWN SOME. THIS WILL ARRIVE BY A COOL FRONT MONDAY THAT MAY ACTUALLY WEAKEN TO A SURFACE TROUGH. THERE COULD BE SOME CONVECTION WITH THIS AS WELL, ESPECIALLY DURING PEAK HEATING. OVERALL WITHIN MORE OF A CYCLONIC FLOW ALOFT, THE MODEL GUIDANCE IS NOT ALL THAT ROBUST WITH LARGE SCALE LIFT. THE GFS SHOWS MORE AMPLIFICATION WHICH MAY LEAD TO MORE ORGANIZED CONVECTION MONDAY, HOWEVER FOR NOW WE KEPT POPS NO HIGHER THAN SLIGHT CHC. SINCE TEMPERATURES ARE FORECAST TO DROP BACK SOME, THE HEAT RELATED HEADLINES WERE NOT EXTENDED. FOR WEDNESDAY AND THURSDAY, A SURFACE LOW IS FORECAST TO TRACK ACROSS THE GREAT LAKES WITH A WARM FRONT DRAPED TO THE SOUTHEAST. THERE IS A RATHER HOT AIRMASS FORECAST TO BE SITTING SOUTHWEST OF THIS WARM FRONT AND IT MAY BE HELD THERE AS JUST ENOUGH TROUGHING HOLDS ACROSS THE NORTHEAST. DESPITE THIS, THE WARM FRONT LOOKS TO LIFT ACROSS OUR AREA LATER WEDNESDAY INTO THURSDAY AS THE FLOW BACKS TO THE SOUTHWEST. SINCE THERE COULD BE SOME TIMING ISSUES WITH THE WARM FRONT, WE OPTED TO LEAN CLOSER TO HPC GUIDANCE WHICH RESULTS IN FORECAST HIGHS GENERALLY IN THE UPPER 80S TO LOWER 90S. THE POPS ARE UNDER SLIGHT CHC WEDNESDAY THEN SLIGHT CHC TO LOW CHC THURSDAY. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE 06Z TAFS ARE GIVING THE HIGHEST CHANCES OF THUNDER MAKING IT INTO THE KPHL, KILG AND KRDG TERMINALS TOWARD MORNING WITH NEAR OR MVFR CONDITIONS. IMPRESSIVE SMALL COMPLEX OF TSTMS IN NWRN PA IS PRODUCING NEARLY 500 CLOUD TO GROUND LIGHTNING STRIKES EVERY 5 MINUTES. THE AIR MASS IS NOT AS UNSTABLE ON OUR SIDE OF THE APLCHNS, SO WE WILL MONITOR ITS PROGRESS. LESS CONFIDENCE ABOUT THE TSTMS MAKING IT INTO THE OTHER TERMINALS IF AT ALL, SO WILL NOT BE INCLUDED. ONCE THIS CLUSTER MOVES THROUGH, WE ARE EXPECTING VFR CONDITIONS FORM THE REST OF THE TAF PERIOD. IN FACT, AS HARD AS IT IS TO FATHOM, WE MAY NOT REACH THE CONVECTIVE TEMPERATURE TODAY, SO HARDLY ANY CUMULUS CLOUDS ARE FORECAST. WEST WINDS SHOULD AVERAGE AROUND 10 TO 15 KTS AND KEEP THE SEA BREEZE FRONT EAST OF ALL OUR NJ TERMINALS. FORECAST SOUNDINGS ARE NOT SHOWING MUCH GUSTINESS. FOR THIS EVENING, NO SIGNIFICANT CLOUDS ARE EXPECTED OR VSBY RESTRICTIONS FOR ANY OF OUR TERMINALS. WINDS SHOULD BECOME LIGHTER AND GENERALLY FROM THE NORTHWEST. OUTLOOK... LATER FRIDAY NIGHT THROUGH SUNDAY NIGHT...VFR WITH THE EXCEPTION OF POSSIBLE LOCAL SUB-VFR DUE TO FOG/HAZE DURING THE EARLY MORNINGS. A COUPLE OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE, HOWEVER THERE IS LOWER CONFIDENCE WITH THE TIMING AND COVERAGE. GENERALLY LIGHT AND VARIABLE WINDS AT NIGHT, THEN WESTERLY NEAR 10 KNOTS DURING THE DAY. THE WINDS COULD SHIFT MORE SOUTHERLY LOCALLY IN THE AFTERNOON AND EARLY EVENING DUE TO ANY MARINE INFLUENCE. MONDAY AND TUESDAY...VFR, ALTHOUGH THERE STILL REMAINS THE CHANCE FOR A FEW SHOWERS AND THUNDERSTORMS. WHILE CONFIDENCE IS ON THE LOWER SIDE REGARDING TIMING AND COVERAGE, IT APPEARS THE AFTERNOON AND EVENING HOURS HAVE A BETTER CHANCE OF THIS OCCURRING. WEST TO NORTHWEST WINDS NEAR 10 KNOTS MAY SHIFT TO THE SOUTHWEST TUESDAY. && .MARINE... CONDITIONS ON OUR WATERS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA TONIGHT AND THROUGH FRIDAY. WINDS WILL PRIMARILY BE SOUTHWESTERLY DURING THE PERIOD. OUTLOOK... THE CONDITIONS ARE ANTICIPATED TO BE MOSTLY BELOW SMALL CRAFT ADVISORY CRITERIA FRIDAY NIGHT THROUGH TUESDAY. A WARM FRONT SHOULD LIFT THROUGH THE AREA FRIDAY MORNING, THEN A COUPLE OF COOL FRONTS SHIFT THROUGH THE REGION UNDER A NORTHWESTERLY FLOW ALOFT. THESE BOUNDARIES GENERALLY LOOK ON THE WEAKER SIDE, HOWEVER A WESTERLY WIND SHOULD SHIFT TO SOUTHWESTERLY AT TIMES ESPECIALLY AS THE AIRMASS WILL BE HOT. AS A RESULT OF THE HOT AIRMASS, THE WINDS MAY LOCALLY INCREASE SOME DURING THE AFTERNOON AND EVENING HOURS. THE SEAS ARE ANTICIPATED TO REMAIN AT OR BELOW 4 FEET. && .TIDES/COASTAL FLOODING... GFS ETSS STILL MODELS POTENTIAL MINOR COASTAL FLOOD EPISODES HERE WITH THE EVENING TIDE CYCLES BEGINNING SUNDAY OR MONDAY AND CONTG THRU AT LEAST JULY 3 FULL MOON WHEN ASTRO TIDE IS WITHIN .3 FT OF THE MINOR TIDAL INUNDATION THRESHOLD. && .RIP CURRENTS... WHILE THE RISK OF DANGEROUS RIP CURRENTS APPEARS LOW FOR THE NEXT SEVERAL DAYS, THERE SHOULD BE SOME ENHANCEMENT OF THE RISK FOR RIP CURRENTS. FIRST ASSOCIATED WITH AN INCREASING S SWELL TO 3 FEET WITH A 8 SECOND PERIOD FRIDAY THAT CONTINUES INTO SATURDAY...ESPECIALLY IF THE WIND AT BUOY 009 IS 180 OR 190 DEGREES, AND THEN WITH AN INCREASINGLY LARGE RATE OF CHANGE IN TIDES AS WE MOVE TOWARD THE FULL MOON EARLY NEXT WEEK. && .CLIMATE... TEMPERATURES ARE EXPECTED TO REACH WELL INTO THE 90S FRIDAY THROUGH SUNDAY. BELOW ARE THE RECORD HIGH TEMPERATURES AND MOST RECENT YEAR OF OCCURRENCE FOR JUNE 29 THROUGH JULY 1 FOR OUR EIGHT CLIMATE SITES. JUNE 29 JUNE 30 JULY 1 PHL 102 - 1934 100 - 1964 102 - 1901 ACY 98 - 1991 98 - 1991 99 - 1968 ILG 98 - 1959 98 - 1964 97 - 1963 ABE 99 - 1934 97 - 1964 97 - 1963 TTN 100 - 1934 98 - 1964 98 - 1945 RDG 99 - 1943 98 - 1964 101 - 1901 GED 99 - 1969 101 - 1959 98 - 1964 MPO 89 - 1944 90 - 1964 88 - 1968 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR PAZ060>062. EXCESSIVE HEAT WARNING FROM NOON TODAY TO 8 PM EDT SUNDAY FOR PAZ067>071. NJ...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR NJZ007>010-012-013-016-020>023-027. EXCESSIVE HEAT WARNING FROM NOON TODAY TO 8 PM EDT SUNDAY FOR NJZ015-017>019. DE...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR DEZ002-003. EXCESSIVE HEAT WARNING FROM NOON TODAY TO 8 PM EDT SUNDAY FOR DEZ001. MD...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR MDZ008-012-015-019-020. MARINE...NONE. && $$ SYNOPSIS...GORSE NEAR TERM...DRAG/GIGI/KLINE SHORT TERM...DRAG/KLINE LONG TERM...GORSE AVIATION...GIGI/GORSE MARINE...DRAG/GORSE/KLINE TIDES/COASTAL FLOODING... RIP CURRENTS... CLIMATE...GIGI
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
151 AM EDT FRI JUN 29 2012 .AVIATION... KEPT WITH PREVIOUS TAFS WITH OVERNIGHT PERIOD RATHER STAGNANT AS INCREASED LL MSTR REMAINS ACROSS THE AREA. DROP IN VSBYS TO MVFR STILL POSSIBLE TOWARDS 12Z BUT NOT ANTICIPATING MUCH IMPACT OVERALL. FRONTAL BOUNDARY WILL REMAIN IN THE GENERAL AREA THROUGH THE PERIOD WITH WEAK DISTURBANCES MOVING THROUGH THE FLOW. WHILE CONVECTIVE CHANCES WILL EXIST FROM MID AFTERNOON ON...MAIN ONE OF CONCERN MOVING THROUGH THE NORTHERN PLAINS WILL LIKELY NOT IMPACT THE AREA UNTIL AFTER 00Z SAT. HAVE LEFT ANY CONVECTIVE MENTION OUT OF TAFS WITH AT LEAST 2 MORE ISSUANCES BEFORE CONCERNS WILL INCREASE. && .PREV DISCUSSION... /ISSUED 838 PM EDT THU JUN 28 2012/ UPDATE... RED FLAG AND HEAT ADVISORY ALLOWED TO EXPIRE. SURFACE BASED CAPE IS EXCEPTIONALLY HIGH OVER THE REGION. COMBINED WITH THE LAKE BREEZE AND OUTFLOW FROM SEVERE CONVECTION OVER CHICAGO AREA... ADDITIONAL CONVECTION IS LIKELY TO SPREAD OVER THE WESTERN QUARTER OF THE CWA. THIS HAS PROMPTED THE ISSUANCE OF SEVERE THUNDERSTORM WATCH 433 UNTIL MIDNIGHT EDT. BEST LOCATION FOR SEVERE THREAT APPEARS TO BE FROM LAPORTE... STARKE AND PULASKI COUNTIES...WITH THE MOST LIKELY PLACEMENT ALONG THE EXISTING SURFACE BOUNDARY ALONG THE STARKE/PULASKI COUNTY LINE. EXPECT THAT AS THE OUTFLOW SURGES SOUTH...THE FOCUS WILL SHIFT FURTHER SOUTH QUICKLY. PREV DISCUSSION... /ISSUED 403 PM EDT THU JUN 28 2012/ SHORT TERM... TONIGHT THROUGH FRIDAY NIGHT. CONT TO FAVOR CAUTIONARY APPROACH WRT POTNL CONVECTIVE DEVELOPMENT IN SHORT TERM FOR CWA. DESPITE INCSRG INSTABILITY THIS AFT/EVE AS SFC DPS BEGIN TO POOL TO NEAR 70F ACRS NWRN CWA THIS AFTN...FAVORED INITIATION REGIONS EXIST BOTH DOWN/UPSTREAM. STILL MODELS SPCLY GFS CONTS TO FAIL TO CAPTURE SIGNIFICANCE OF DRY GROUND/D3 DROUGHT CONDS THAT HAVE EMERGED ACRS NRN IN AND CONT TO SHAVE SVRL DEGREES DOWNWARD. THIS AM NOTED SHORTWAVE/700H JETLET GENERATED XTRMLY HIGH ELEVATED CONVECTION INVOF KCID...THIS FEATURE TO PUSH INTO NWRN OH THIS EVE WITH CAP SLOWLY DERIDED PER SPC RAP IN TANDEM WITH CONCEPTUAL MODEL EXPECTATIONS...THOUGH EAST OF CWA. WELL WEST OF CWA WITHIN DCPVA ZONE AMID OVERLAP ALONG NRN EDGE OF STRONGER/LESS INHIBITED INSTABILITY AXIS FM NWRN IL WWD INTO SERN NE WITH MLCAPE 4000-5000 J/KG AND SRN PERIPHERY OF HIR DEEP LYR /0-6KM/ SHEAR OF 40-55KTS TO LKLY SUPPORT MULTIPLE MCS DEVELOPMENT ACRS PLAINS INTO INTO IA/MO NEAR/AFTER SUNSET AS SRLY 925-850MB JET STRENGTHENS/NOSES ACRS CNTL KS. ADDNL/CONTD CONVECTIVE SUPPORT ACRS IA/MO THROUGH DAYBREAK AS ERN PERIPHERY OF LLJ VEERS. LACK OF ULVL JET SUPPORT ACRS CWA FURTHER POINTS TO LIKEN DRY BEGETS DRY. FLATTENED RIDGE TO ALLOW SHALLOW SFC FNTL ZONE TO SLIDE SEWD QUIETLY THROUGH CWA...WITH ZONE OF RICH 0-0.5KM THETA-E LAID OUT FM NRN IL INTO CNTL IN ON FRIDAY. SLIGHT CHC FOR LATE AFTN/EVE CONVECTION INITIATION RELEGATED TO ONLY SWRN CWA INVOF BNDRY WITH INCRSD UPPER LVL DIVERGENCE AS NRN PLAINS UPR JETLET MOVES INTO SERN LWR MI/LWR GRTLKS COINCIDENT WITH GREATEST INSTABILITY. LONG TERM... / SATURDAY THROUGH THURSDAY / WEST TO NORTHWEST FLOW ALOFT IS EXPECTED TO PERSIST THIS WEEKEND INTO EARLY NEXT WEEK OVERTOP A FLATTENED UPPER LEVEL RIDGE. THE POLAR JET WILL GENERALLY REMAIN WELL NORTH AND EAST OF THE REGION STILL ALLOWING HIGHS TO REACH THE 90S EACH DAY AS 850 HPA TEMPS GENERALLY STAY AOA 20C...WITH MID LVL CLOUD DEBRIS FROM UPSTREAM CONVECTION BEING THE ONLY HOPE FOR COOLER TEMPS. AT THE SURFACE A DIFFUSE/SHALLOW QUASI-STATIONARY BOUNDARY IS FCST TO HANG AROUND THE NORTHERN OHIO VALLEY WWD TOWARDS THE CENTRAL PLAINS THROUGH SUNDAY...POSSIBLY MIXING NORTH OF THE AREA OR WASHING OUT BY MONDAY. WILL LIKELY SEE CONVECTIVE COMPLEXES FIRE IN THE VICINITY OF THIS BOUNDARY FRIDAY AND SATURDAY NIGHT NEAR IOWA AS SEVERAL LOW AMPLITUDE (CONVECTIVELY ENHANCED/INDUCED) SHORTWAVES CREST THE REBUILDING CENTRAL PLAINS UPPER RIDGE. THESE POTENTIAL MCS COMPLEXES WILL LIKELY WEAKEN WITH EWD PROGRESSION AS THEY OUTRUN BETTER LOW LVL FORCING (LLJ) AND DRY OUT OVER POORLY MODELED DRY LOW LEVELS (MODELS OVERDOING BOUNDARY LAYER/SOIL MOISTURE WITH CLIMO BIAS AND THEREFORE INSTABILITY/SFC DEWPOINTS/ETC). WITH THIS CONFIDENCE FOR ANY MEASURABLE RAINFALL REMAINS LOW DURING THIS TIME AS THINK THE BEST CASE SCENARIO IS FOR A MCV TO BRING HIGH BASED SHOWERS WITH LITTLE/NO DROUGHT RELIEF. ALSO EXPECT AFTERNOON CONVECTIVE RE-DEVELOPMENT TO BE ISOLATED AT BEST ALONG ANY COMPOSITE OUTFLOW BOUNDARIES. AS A RESULT OPTED TO KEEP POPS IN THE 10-20 PERCENT RANGE (MAINLY NO WX MENTION) AS WOULD EXPECT MOST OF THIS PERIOD TO BE DRY IN THIS ONGOING D1-D3 DROUGHT. THE ROCKIES/CENTRAL ROCKIES UPPER RIDGE WILL BUILD NWD TOWARDS THE UPPER MIDWEST NEXT WEEK WITH HEIGHT RISES/WARMING AND DRY CONDITIONS ANTICIPATED LOCALLY. TEMPS COULD MAKE ANOTHER RUN AT 100F BY DAYS 6/7. AVIATION... /18 UTC TAFS/ DIFFICULT FCST THIS ITERATION...MAINTAIN PRIMARILY VFR TAFS WITH POINT CONVECTIVE CHCS REMAINING BLO THRESHOLD FOR INCLUSION AS MLCIN RMNS STOIC ACRS NRN IN THIS AFTN. HEIGHTENED CHCS FOR INITIATION EXIST BOTH UP/DOWNSTREAM OF RGN LATER THIS EVENING...POTNLY PROVIDING DRY FROPA LATER TONIGHT. CONVERGENCE OF NEAR SFC HYGROSCOPIC POLLUTANTS AND SFC DP POOLING TO NEAR 70 MAY PROVIDE IMPETUS FOR SUNRISE BR DVLPMNT. ZONE OF HIR SFC BASED INSTABILITY THEREAFTER RELEGATED FM ERN IA INTO CNTL IN MIDDAY FRIDAY/FRIDAY AFTN...TAKING FOCUS AREA FOR REDEVELOPMENT SOUTH OF TAF SITES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MURPHY LONG TERM...STEINWEDEL AVIATION...FISHER
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1238 AM EDT FRI JUN 29 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 315 PM EDT THU JUN 28 2012 RECORD BREAKING HEAT SET TO ARRIVE OVER THE OHIO VALLEY LATE THIS AFTERNOON AND FRIDAY AS DEEP UPPER RIDGING EXPANDS INTO THE REGION. A WEAK FRONTAL BOUNDARY WILL SLIP INTO THE LOWER GREAT LAKES TONIGHT AND REMAIN IN THE REGION THROUGH THE WEEKEND. THE PROXIMITY OF THE FRONT MAY BE ENOUGH TO GENERATE A FEW THUNDERSTORMS BUT EXPECT MOST LOCATIONS WILL REMAIN DRY. HOT WEATHER WILL PERSIST INTO NEXT WEEK AS THE CORE OF THE UPPER RIDGE REMAINS CENTERED JUST TO THE WEST OVER THE CENTRAL PLAINS. && .NEAR TERM /TONIGHT/... ISSUED AT 1030 PM EDT THU JUN 28 2012 WILL HAVE TO ADD ISOLATED THUNDER TO A SLIVER OF FAR NORTH CENTRAL INDIANA. THESE STORMS CONTINUE TO WEAKEN BUT WILL GET CLOSE ENOUGH TO THE FORECAST AREA BOUNDARY THAT A MENTION IS PROBABLY NECESSARY. PREVIOUS DISCUSSION FOLLOWS. GOING FORECAST WAS IN FAIRLY GOOD SHAPE...ONLY SOME MINOR TWEAKS REQUIRED. SMALL COMPLEX OF STRONG TO SEVERE THUNDERSTORMS ONGOING ACROSS NORTHWEST INDIANA MAY THREATEN TO CROSS THE NORTHERN BORDER OF THE FORECAST AREA...BUT SUSPECT THAT THESE STORMS WILL QUICKLY DIE AS THEY BECOME FURTHER REMOVED FROM THE LAKE BREEZE BOUNDARY. THIS IS SUPPORTED BY HRRR REFLECTIVITY PROGS AND 700 MB TEMPS OF 16C. IN FACT...THESE STORMS ARE ALREADY BEGINNING TO WEAKEN. WILL HAVE TO MONITOR THIS CLOSELY OVER THE NEXT 1 TO 2 HOURS. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... ISSUED AT 315 PM EDT THU JUN 28 2012 ...NEAR RECORD HIGH TEMPERATURES AND FIRE DANGER CONTINUE FRIDAY AND INTO THIS WEEKEND... FORECAST CHALLENGES REMAIN ON THE HEAT AND TO A LESSER EXTENT POTENTIAL FIRE DANGER (AGAIN DISCUSSED IN MORE DETAIL IN THE FIRE SECTION BELOW). AS THE HEAT RIDGE SLOWLY SINKS BACK TO THE SOUTHWEST. ADDITIONAL CHALLENGES REGARDING CONVECTIVE CHANCES AS WEAK BOUNDARY DROPS INTO THE REGION. POTENTIAL FOR A CONTINUATION OF THE IMPRESSIVE HEAT THROUGH THE PERIOD BUT THE PRESENCE OF THE FRONT INTO THE REGION INTRODUCES ADDITIONAL VARIABLES INTO THE FORECAST THAT WILL HAVE IMPACTS POTENTIALLY ON TEMPS. CONVECTIVE DEVELOPMENT REMAINS A DISTINCT POSSIBILITY IN THE VICINITY OF THE FRONT FRIDAY THROUGH SATURDAY...BUT SEVERAL LIMITING FACTORS TO CONSIDER. WARM BOUNDARY LAYER HIGHLIGHTED BY LARGE AMOUNTS OF CONVECTIVE INHIBITION AND DESPITE AN INCREASE IN DEWPOINTS AS SOME MOISTURE POOLING DEVELOPS IN VICINITY OF THE BOUNDARY...STRONGLY SUSPECT MODELS ARE STILL OVERDOING AVAILABLE LOW LEVEL MOISTURE BOTH DAYS. WITH THAT BEING SAID...THIS KIND OF HEAT IS GENERATING ABUNDANT INSTABILITY ABOVE THE INVERSION AND SHOULD THE CAPPING WEAKEN ENOUGH EITHER DAY... POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WITH A DAMAGING WIND THREAT WOULD BE POSSIBLE. MODEL CONSENSUS ALSO SUGGESTING CONVECTIVE COMPLEXES COULD DEVELOP AND RIDE THE RIDGE PERIPHERY THROUGH THE PERIOD...POSSIBLY IMPACTING NORTHERN COUNTIES. WITH THE LIMITING FACTORS MENTIONED ABOVE HOWEVER...WILL CARRY NO HIGHER THAN 20 POPS NORTH OF A TERRE HAUTE TO GREENSBURG LINE FRIDAY/FRIDAY NIGHT... SINKING A TOUCH FURTHER SOUTH ON SATURDAY DUE TO POTENTIAL LOCATION OF THE BOUNDARY. THE POTENTIAL FOR PERIODS OF CLOUDS AND CONVECTION DO INCREASE UNCERTAINTY IN TEMP FORECASTS FRIDAY AND SATURDAY...BUT STILL FEEL PERSISTENCE IS THE BEST OPTION AT THIS POINT. BOUNDARY LAYER TEMPS WILL BE COOLER BOTH DAYS THAN TODAY DUE TO THE FLATTENING OF THE RIDGE. TEMPS...WILL BE WELL ABOVE THE MAVMOS GUIDANCE FOR HIGHS BOTH FRIDAY THROUGH SUNDAY WITH THE HIGHLIGHTED PROBLEMS THE OPERATIONAL GFS IS EXPERIENCING WITH SAMPLING BOUNDARY LAYER CONDITIONS. WILL BE MUCH CLOSER TO THE METMOS...AND HAVE GENERALLY BUMPED TEMPS A DEGREE OR TWO FROM PREVIOUS FORECAST BOTH DAYS. RECORD HIGHS AT INDY WILL BE THREATENED BOTH DAYS. ALSO TO NOTE...INDIANAPOLIS HAS ONLY HAD CONSECUTIVE DAYS AT 100 OR HIGHER IN JUNE HAPPEN ONCE IN RECORDED HISTORY...FROM JUNE 28-30 1934. AM FORECASTING 101 ON FRIDAY AND NEAR 100 ON SATURDAY AND SUNDAY IN INDY. UNDERCUT MOS GUIDANCE ON OVERNIGHT LOWS BASED ON RECENT PERFORMANCE AND ANTECEDENT DRY CONDITIONS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 216 PM EDT THU JUN 28 2012 MAIN CHALLENGE TO THE EXTENDED WILL BE WHETHER OR NOT AND IF SO... WHEN TO HAVE THUNDERSTORM POPS. TEMPERATURES WILL ALSO BE FOCUSED ON WITH THE SEVERE DROUGHT IN PROGRESS. AGREE WITH THE PMDEPD FROM HPC IN THROWING THE 12Z GFS OUT WHICH PLACES CENTRAL INDIANA CLOSER TO THE RIDGE RIDING QPF. THE 00Z ECMWF AND OTHERS SPREAD THE PLAINS RIDGE FURTHER NORTHEAST ACROSS CENTRAL INDIANA THROUGH THE EXTENDED WHICH WOULD TEND TO SUPPRESS THUNDERSTORM DEVELOPMENT. IN ADDITION...THE ONGOING DROUGHT WOULD TEND TO FAVOR A DRY FORECAST WITH AFTERNOON TEMPERATURES A COUPLE OF DEGREES WARMER THAN THE CENTRAL REGION INITIALIZATION AND DEW POINTS A FEW DEGREES LOWER. && .AVIATION /DISCUSSION FOR THE 290600Z TAFS/... ISSUED AT 1238 AM EDT FRI JUN 29 2012 VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD. CIRRUS FROM DISSIPATED THUNDERSTORMS WILL MOVE ACROSS THE SITES TONIGHT. TEMPERATURES LOOK TO REMAIN WARM ENOUGH TO PRECLUDE FOG MENTION. FRONTAL BOUNDARY OVER NORTHERN INDIANA IS EXPECTED TO SLOWLY SAG SOUTHWARD THROUGH THIS PERIOD. HOWEVER FORECAST SOUNDINGS REMAIN QUITE DRY...AND CU RULE IS STRONGLY POSITIVE. THUS JUST SOME SCT CIRRUS WILL BE INCLUDED IN THIS TAF ISSUANCE. CANNOT RULE OUT ISOLATED CONVECTION ALONG THE BOUNDARY...BUT COVERAGE IS TOO LOW TO MENTION IN TAFS. && .FIRE WEATHER... ISSUED AT 950 PM EDT THU JUN 28 2012 RED FLAG WARNING HAS BEEN ALLOWED TO EXPIRE AS CONDITIONS HAVE IMPROVED WITH LOSS OF DAYTIME HEATING. ELEVATED FIRE DANGER WILL EXIST WITH EXPECTED CONDITIONS FOR FRIDAY AND SATURDAY. AT THIS TIME WE DO NOT BELIEVE THE CONDITIONS WILL WARRANT A RED FLAG WARNING...BUT MAY REQUIRE ENHANCED FIRE DANGER WORDING...ALONG A SPECIAL WEATHER STATEMENT AND MENTION IN THE HAZARDOUS WEATHER OUTLOOK. && .CLIMATE... ISSUED AT 950 PM EDT THU JUN 28 2012 RECORD HIGHS FOR KIND: ALL TIME - 106 (7/14/1936...7/21/1934...7/22/1901) JUNE - 104 (6/28/2012) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) && .IND WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ SYNOPSIS...SMF NEAR TERM...NIELD SHORT TERM...RYAN/SMF LONG TERM....MK AVIATION...JP/50 FIRE...SMF/NIELD CLIMATE...RYAN/NIELD
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1221 AM CDT FRI JUN 29 2012 .AVIATION... SFC FRONT IS STALLING OVER SOUTHEAST IA AND WEST CENTRAL IL AND WILL REMAIN IN VICINITY OF THE AREA THROUGH FRI EVE. TSRA CHCS ARE PRESENT AT TERMINALS THROUGHOUT PD WITH BOUNDARY NEARBY BUT VERY TOUGH TO PIN DOWN TIMING AND LOCATION. CONVECTION OVER NE/KS IS TIED TO UPPER LEVEL ENERGY EJECTING OUT OF CO. W-E CLOUD BAND NEAR AND NORTH OF FRONTAL ZONE SOUTH OF I-80 MAY DEVELOP INTO SHRA/TSRA LATER TNGT INTO FRI AM IF LOW LEVEL JET CAN VEER AS MODELS SUGGEST ALTHOUGH THEY ARE NOT HANDLING NE/KS CONVECTION WELL AND SO HAVE SOME CONCERN JET COULD STAY ANCHORED TO THIS CONVECTION. ALSO SEEING CLOUDS OF 3500-5000 FT AGL BLOSSOMING IN NORTH AND NORTHEAST IA VICINITY OF ELEVATED CONVERGENT AXIS AND THIS COULD EVENTUALLY DEVELOP INTO CONVECTION NEXT FEW HRS. ANY CONVECTION THAT DEVELOPS WILL LIKELY LINGER OVER AREA THROUGH MIDDAY. THEN ATTENTION TURNS TO COLORADO WAVE THAT MAY BRING BETTER CHCS OF TSRA LATE FRI AFTN AND FRI NGT. HOWEVER... HOW EVENTS UNFOLD OVRNGT/FRI AM WILL HAVE IMPACT ON PCPN LAYOUT LATE AND SO OPTED TO LEAVE OUT THIS SECONDARY AND PERHAPS BETTER CHC LAST 6-10 HRS IN TERMINALS FOR NOW. MOISTURE AXIS NEAR/S OF I-80 WITH LIGHT WINDS WILL FUEL FOG AND HAZE... AND POSSIBLY SOME LOW CLOUDS WITH MVFR CONDITIONS IN SPOTS. IN ADDITION ANY STORMS NEXT 24 HRS WILL HAVE POTENTIAL TO BE SEVERE WITH DAMAGING WINDS MAIN THREAT. && .PREV DISCUSSION... /ISSUED 951 PM CDT THU JUN 28 2012/ UPDATE... REMOVED A FEW MORE COUNTIES FROM HEAT ADVISORY OVER NORTHEAST IA AND NORTHWEST IL... AS DRIER AIR CONTINUES MOVING IN ALLOW GRADUAL IMPROVEMENT IN CONDITIONS. ZFP/GRID UPDATE HAS BEEN SENT. OTRW... CHCS STILL EXIST FOR STORMS OVRNGT... ESPECIALLY AFT 09Z AND CONTINUING FRI AM WITH VEERING LOW LEVEL JET AND APPROACHING DISTURBANCE FROM CO. PREV DISCUSSION... /ISSUED 809 PM CDT THU JUN 28 2012/ UPDATE... SENT ZFP/GRID UPDATE TO REMOVE NORTHEAST IA COUNTIES MAINLY ALONG AND NORTH OF HWY 30 FROM HEAT ADVISORY... AS MUCH DRIER AIR IS BRINGING MARKED IMPROVEMENT IN CONDITIONS THERE. WILL CONTINUE TO MONITOR PROGRESS OF LOW LEVEL DRYING TNGT FOR ADDITIONAL CHGS TO HEAT ADVISORY. LATEST FEW RUNS OF RAP MODEL HAVE BEEN SHOWING DEWPTS LOWERING INTO THE 50S AND 60S DOWN TO I-80 IN EASTERN IA. ALSO REMOVED SLIGHT CHC POPS HWY 20 CORRIDOR THIS EVE WITH THE DRIER AIR. CHANCE OF STORMS STILL LOOKS REASONABLE OVERNIGHT AND FRI MORNING AS NEXT IMPULSE OVER CO MOVES E/NE AROUND PERIPHERY OF HEAT DOME AND INTO AREA WHILE INTERACTING WITH STALLING FRONTAL ZONE OVER SOUTHEAST IA INTO WEST CENTRAL IL. FAVORED CORRIDOR FOR PCPN SHOULD IT DEVELOP APPEARS TO BE HWY 30 TO HWY 34... BUT THIS COULD SHIFT SOUTHWARD SOME DEPENDING ON MOVEMENT OF LOW LEVEL DRIER AIR. SEVERE THREAT EXISTS WITH ANY ORGANIZED CONVECTION GIVEN EXTREME INSTABILITY... WITH MAIN THREAT BEING DAMAGING WIND. PREV DISCUSSION... /ISSUED 322 PM CDT THU JUN 28 2012/ SYNOPSIS... 12Z UA ANALYSIS HAS AN 850MB COLD FRONT FROM UPPER MICHIGAN INTO WESTERN NEBRASKA WITH MID AND UPPER TEEN DEW POINTS ALONG AND JUST AHEAD OF IT. A WEAK LLJ RAN FROM WEST TEXAS INTO THE MID MISSISSIPPI VALLEY. SATELLITE IMAGES THROUGH MID AFTERNOON SHOW PLENTY OF ACCAS AND SOME DIURNAL CU DEVELOPMENT ASSOCIATED WITH THE SFC COLD FRONT FROM WISCONSIN INTO NEBRASKA. 18Z SFC ANALYSIS HAD A WEAK LOW JUST EAST OF KMKE WITH ANOTHER IN SOUTHWEST KANSAS. THE COLD FRONT RAN IN BETWEEN THE TWO LOWS WITH A PRE-FRONTAL TROF FROM SOUTHEAST WISCONSIN INTO NORTHWEST MISSOURI. DEW POINTS IN THE VICINITY OF THE FRONT WERE IN THE LOW AND MID 70S. DEW POINTS DROPPED OFF QUICKLY INTO THE 40S AND 50S ACROSS THE NORTHERN PLAINS. SHORT TERM...TONIGHT AND FRIDAY NONLINEAR PROCESSES ARE DOMINATING THE SENSIBLE WX WHICH RESULTS IN LOW MODEL PREDICTABILITY. BASED ON EXTRAPOLATION/INTERPOLATION OF SFC OBS...IT APPEARS THE HEAT ADVISORY VERIFIED FOR A FEW HOURS OVER THE SOUTHERN PARTS OF BUCHANAN AND DELAWARE COUNTIES...SOUTH OF HWY 20...WHEN USING DATA FROM RWIS SITES. THROUGH MID AFTERNOON THE ACCAS AND SFC BASED CU DEVELOPMENT BEHIND THE FRONT HAS BECOME SLIGHTLY MORE AGITATED. RIGHT NOW IT LOOKS DOUBTFUL THAT ANY ELEVATED CONVECTION WILL DEVELOP BUT WILL INCLUDE SCHC POPS IN THE HWY 20 CORRIDOR THIS EVENING IN CASE SOMETHING DEVELOPS. THE HEAT HEADLINES WILL REMAIN AS IS BUT THERE IS A POSSIBILITY OF AN EXTENSION OVER THE SOUTH 40 PERCENT OF THE CWFA FOR FRIDAY. ALL OF THIS IS DEPENDENT ON WHERE AND IF CONVECTION DEVELOPS OVERNIGHT. THE HEAT HEADLINES FOR A GOOD CHUNK OF THE CWFA WILL PROBABLY BE CANCELLED LATE THIS EVENING OR OVERNIGHT. USING CONCEPTUAL MODELS AND SATELLITE DATA...AN MCS SHOULD DEVELOP IN THE VICINITY OF KOMA BY MIDNIGHT. THE OVERALL FLOW SHOULD TAKE IT GENERALLY EASTWARD WITH THE AREA SOUTH OF HIGHWAY 20 AND NORTH OF HIGHWAY 34 FAVORED. CONVECTION WOULD BE ELEVATED. A NEGATIVE FOR DEVELOPMENT TONIGHT IS THAT THE LLJ IS NOT AS STRONG AS LAST NIGHT. ASSUMING CONVECTION DOES DEVELOP AND MOVE AS SUGGESTED BY THE TRACK OF VORT MAXES...A DECAYING MCS SHOULD BE OVER THE CWFA FRIDAY MORNING. BOUNDARIES FROM THIS MCS AND AN APPROACHING VORT MAX...LIKELY FROM ANOTHER MCS...SHOULD INITIATE DIURNAL CONVECTION FRIDAY AFTERNOON ACROSS THE CWFA. CONVECTION THAT DEVELOPS FRIDAY AFTERNOON COULD GET INTERESTING. DIFFERENTIAL THETA E LAPSE RATES WILL BE VERY LARGE. SO...STORMS THAT DEVELOP COULD BE OF THE PULSE SEVERE TYPE WITH WIND BEING THE PRIMARY THREAT. 08 LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY ABOVE NORMAL TEMPERATURES AND HUMID WITH A CHANCE OF THUNDERSTORMS MOST...IF NOT ALL DAYS. OVERVIEW...CHALLENGING FORECAST OF WHERE AND WHEN CONVECTION OCCURS. INITIALIZATION GOOD WITH NORMAL PROBLEMS OF LOW LEVEL MOISTURE FIELDS THAT HAVE PLAGUED MOST GUIDANCE THE PAST SEVERAL WEEKS TO MONTHS. VERIFICATION AT 18Z SUGGESTS USING FORCING OF MAINLY A MIX OF GFS/NAM/HI-RES ECMWF. THIS IS A TYPICAL SUMMER PRECIPITATION REGIME OF VERY GOOD CONFIDENCE OF EPISODES OF CONVECTION..BUT PROBABLY POOR ON TIMING AND LOCATION BEYOND 6-12 HOURS AHEAD DUE TO NON-LINEAR NATURE AND OUTFLOW BOUNDARIES IMPACTING SUBSEQUENT CONVECTION. HIGH TO EXTREME STABILITY WITH MUCAPES OF 2500 TO 4000+ J/KG...MAX DIFFERENTIAL THETA_E OF 30C OR MORE AND WBZ 12-14K AGL SUPPORTIVE OF RISK OF DAMAGING TO VERY DAMAGING STRAIGHT LINE WINDS. THE NEXT SEVERAL DAYS COULD SEE REPORTS OF 80+ MPH WINDS NEAR OR IN OUR FORECAST AREA DUE TO THE HIGH TO EXTREME INSTABILITY. TEMPERATURES TO BE ABOVE NORMAL BY 5 TO 10 DEGREES MOST DAYS. FRIDAY NIGHT AND SATURDAY...MINOR CHANGES WITH SLIGHTLY HIGHER POPS IN NORTH 1/2 TO 2/3 AREA DUE TO STALLED FRONT OVER SOUTH PORTIONS. LOCAL TOOLS DO SUGGEST MOST LOCATIONS TO RECEIVE SOME PRECIPITATION. HIGH PW/S OF 1.5 TO 2 INCHES AND WEAKER STEERING SUGGEST LOCALLY HEAVY RAINFALL OF 2 PLUS INCHES FOR LATER SHIFTS TO RECONSIDER. BEST FORCING SUGGESTED TO OCCUR ALONG HIGHWAY 30 LATE FRIDAY NIGHT INTO SATURDAY...THIS MAY RESULT IN LOWER MAX TEMPERATURES. CONCERN OF A DECENT AREA OF STRONG WINDS AS MENTIONED EARLIER DUE TO EXTREME INSTABILITY. LOWS MOSTLY IN THE LOWER 70S AND HIGHS AROUND 90 NORTH TO MIDDLE 90S SOUTH. NORTH SECTION HIGHS COULD BE LOWER BY SEVERAL DEGREES WITH COOL POOL OUTFLOW BOUNDARY. HEAT INDICES IN SOUTH MAY REACH 100 DEGREES IN THE AFTERNOON. SOME CONCERN OF TRAINING OF STORMS THAT COULD ISOLATED VERY HEAVY RAIN AMOUNTS (AOA 3 INCHES) ALSO FOR LATER SHIFTS TO REASSESS INTO SATURDAY MORNING WITH HYDRO CONCERNS OF FLASH FLOODING. SATURDAY NIGHT THROUGH SUNDAY...LITTLE CHANGE WITH ANOTHER ROUND OF CONVECTION SUGGESTED WITH POOR CONFIDENCE OF LOCATION/S FOR LATER SHIFTS. THIS IS BECAUSE THE EARLIER OUTFLOW BOUNDARY/IES THAT SHOULD RESULT IN A DIFFERING LOCATION FOR UPDRAFT FORCING AND RAINFALL. MCS GENERATION TOOL SUPPORTS WITH A GOOD OUTFLOW BOUNDARY A FURTHER SOUTH TREND FOR LATER SHIFTS TO PRECIPITATION ATTM. SIMILAR RISKS OF SEVERE AND LOCALLY HEAVY RAINFALL WITH AGAIN IMPACTS ON HIGH TEMPERATURES POSSIBLY LOWER BY UP TO 5 DEGREES COOLER POSSIBLE...MAINLY CENTRAL OR NORTH SECTIONS. SOUTH SECTIONS COULD AGAIN EXPERIENCE HEAT INDEX VALUES OF 100 DEGREES THE AFTERNOON. SUNDAY NIGHT THROUGH THURSDAY...AREA ON EDGE OF TYPICAL MID SUMMER "RING OF FIRE" WITH LOWER RISK OF CONVECTION THAT MAY PROPAGATE INTO AREA WITH NORTHERN AND EASTERN SECTIONS AT THE GREATEST RISK. THERE WILL REMAIN A SEVERE STORM POTENTIAL WITH STRONG WINDS DUE TO HIGH INSTABILITY. TEMPERATURES LITTLE CHANGED WITH HIGHS MOSTLY 90 TO 95 DEGREES AND LOWS MOSTLY 70 TO 75 DEGREES AND AFTERNOON HEAT INDICES 95 TO 100 DEGREES SUGGESTED. NICHOLS && .DVN WATCHES/WARNINGS/ADVISORIES... IA...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR CEDAR-CLINTON-DES MOINES- HENRY IA-IOWA-JEFFERSON-JOHNSON-KEOKUK-LEE-LOUISA-MUSCATINE- SCOTT-VAN BUREN-WASHINGTON. IL...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR BUREAU-HANCOCK-HENDERSON- HENRY IL-MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-WARREN- WHITESIDE. MO...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR CLARK-SCOTLAND. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1247 AM CDT FRI JUN 29 2012 ...UPDATED FOR THE 06Z TAF ISSUANCE... .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 208 PM CDT THU JUN 28 2012 A WEAK SURFACE BOUNDARY WILL EXTEND ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. EXACT LOCATION OF THIS BOUNDARY DIFFERS SLIGHTLY BETWEEN THE NAM, RAP, AND HRRR BUT ALL MODELS TEND TO SUPPORT A SMALL CHANCE FOR A FEW HIGH BASED THUNDERSTORMS NEAR THIS BOUNDARY LATE TODAY. GIVEN THIS BOUNDARY LOCATION AS OF 19Z AND SOME HINTS OF AFTERNOON CLOUDS DEVELOPING IN SOUTHEAST COLORADO NEAR THIS BOUNDARY WILL GO AHEAD AND INSERT A MENTION OF ISOLATED HIGH BASED THUNDERSTORMS IN A FEW LOCATIONS ACROSS WEST CENTRAL KANSAS...ESPECIALLY NEAR THE COLORADO BORDER. GIVEN THE FORECAST MODEL SOUNDING PROFILES ANY STORM THAT DOES DEVELOP MAY BE CAPABLE OF PRODUCING WIND GUSTS UP TO 40 MPH. ANOTHER HOT DAY IS IN STORE FOR ALL OF WESTERN KANSAS ON FRIDAY. BASED ON MODEL SOUNDINGS MIXED LAYER HEIGHT AND 700MB TEMPERATURES AT 00Z SATURDAY PLUS A SUPER SUGGESTS THE PREVIOUS FORECAST WITH HIGHS OF 105 TO 108 WERE STILL ON TRACK. THIS COMBINED WITH DEW POINTS FALLING BACK INTO THE LOW TO MID 50S WILL GIVE RISE TO FEW HOURS OF HEAT INDEX READINGS AROUND 105 DEGREES FOR A FEW LOCATIONS IN SOUTH CENTRAL AND NORTH CENTRAL KANSAS. AFTERNOON RELATIVE HUMIDITIES ACROSS ALL OF WESTERN KANSAS IS EXPECTED TO BOTTOM OUT IN THE 15 TO 20 PERCENT RANGE. AT THIS TIME AM LEANING TOWARDS ANOTHER HEAT ADVISORY FOR SEVERAL COUNTIES ONCE AGAIN ALONG AND EAST OF 183 BUT HOLD OFF ON ANY FIRE WEATHER WATCHES OR WARNINGS. A FEW HIGH BASED AFTERNOON CLOUDS WILL ALSO BE POSSIBLE ACROSS PORTIONS OF WESTERN KANSAS AGAIN LATE FRIDAY AFTERNOON AS TEMPERATURES CLIMB TO AROUND 105 DEGREES. INSTABILITY HOWEVER BASED ON MODEL SOUNDINGS NOT OVERLY IMPRESSIVE. IF A FEW STORMS DO DEVELOP THEY WILL LIKELY BE ISOLATED AND A LATE DAY/EARLY EVENING EVENT. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 257 PM CDT THU JUN 28 2012 HOT AND DRY CONDITIONS WILL CONTINUE THROUGH THE EXTENDED PERIOD. BLENDED THE FORECAST TO THE 12Z ECMWF WHICH KEEPS SOUTHWEST KANSAS DRY AND HOT. THERE MIGHT BE A SLIGHT COOL DOWN SUNDAY AS 850-700 HPA TEMPERATURES COOL SLIGHTLY AS A SUBTLE UPPER LEVEL WAVE PASSES TO THE NORTH. OTHERWISE ...THE UPPER LEVEL RIDGE AMPLIFIES THROUGH NEXT WEEK. WILL KEEP MAXES IN THE 99-102 DEG F RANGE WITH LOWS IN THE 70S DEG F. WITH SUCH WARM TEMPERATURES ALOFT, NOT EXPECTING ANY STORMS THROUGH THE PERIOD. FORECAST SOUNDINGS SHOW A WELL MIXED AND DRY ATMOSPHERE EACH DAY SO EVEN IF A STORM WOULD TO DEVELOP, IT WOULD MOST LIKELY BE VERY ISOLATED WITH ANY PRECIPITATION EVAPORATING BEFORE REACHING THE GROUND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1240 AM CDT FRI JUN 29 2012 VFR CONDITIONS WILL CONTINUE TONIGHT AND FRIDAY. HIGH PRESSURE AT THE SURFACE STRETCHES FROM COLORADO TO TENNESSEE, WITH LEE TROUGHING NEAR THE COLORADO ROCKIES. A SMALL SHORT WAVE IS TRAVELING ACROSS WESTERN KANSAS, TRIGGERING A FEW ISOLATED THUNDERSTORMS. THE SUPPORT FOR THESE STORMS WILL DIMINISH BY 09Z, BUT THE KGCK TAF WILL HAVE SHOWERS IN A TEMPO GROUP. WINDS WILL GENERALLY BE FROM THE SOUTH FROM 10 TO 15 KNOTS TONIGHT, BUT INCREASE FRIDAY MID-MORNING TO 15 TO 25 KTS AND GUSTY. && .PRELIMINARY POINT TEMPS/POPS... DDC 75 105 73 100 / 10 10 10 10 GCK 73 103 73 100 / 10 10 10 10 EHA 73 103 71 99 / 10 10 10 10 LBL 74 103 72 100 / 10 10 10 10 HYS 75 105 75 101 / 10 10 10 10 P28 76 105 75 100 / 10 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 9 PM CDT THIS EVENING FOR KSZ031-046-065-066-079>081-089-090. && $$ SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
342 AM EDT FRI JUN 29 2012 .SYNOPSIS... ISSUED AT 342 AM EDT FRI JUN 29 2012 HIGHS AROUND 90 OR HIGHER ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK. CHANCES FOR RAIN ARE LOW SO THE VERY DRY WEATHER WILL CONTINUE. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 342 AM EDT FRI JUN 29 2012 FORECAST CONCERNS DEAL MAINLY WITH LOW CHANCES OF PCPN FOR THE NEXT FEW DAYS. DIDN/T CHANGE THE FCST MUCH. THE WEAK COLD FRONT THAT PASSED THROUGH THE REGION YESTERDAY STRETCHES FROM NORTHERN OHIO WWD THROUGH NRN ILLINOIS. THIS BOUNDARY WILL LIKELY ACT AS A FOCUS FOR CONVECTION DEVELOPING OVER THE CENTRAL PLAINS EARLY THIS MORNING AS IT MOVES EWD. HRRR AND ECMWF SUGGEST THAT SOME OF THE PLAINS CONVECTION WILL MOVE ACROSS IOWA AND NRN ILLINOIS AROUND 12Z BEFORE MOVING JUST SOUTH OF THE CWA MID MORNING. WE ADDED A SLIGHT CHANCE FOR A FEW HOURS OVER THE FAR SW CWA TO ACCOUNT FOR THIS. THE FRONTAL BOUNDARY TO THE SOUTH IS PROGD TO REMAIN SOUTH OF THE CWA THROUGH EARLY SUNDAY BEFORE BEGINNING TO MOVE NORTHEASTWARD. THUS CHANCES FOR PCPN ARE SLIM UNTIL SUNDAY WHEN CHANCES IMPROVE A BIT. AN UPPER TROUGH WILL TRY TO MOVE SOUTH OVER NRN LWR SUNDAY AT THE SAME TIME THAT THE SFC BOUNDARY IS LIFTING NORTH. H8 TEMPS WILL BE SEVERAL DEGREES COOLER TODAY THAN FRIDAY. THUS WE/LL LIKELY SEE HIGHS AROUND 90 VS MID TO UPPER 90S ON FRIDAY. AS A RESULT WE WON/T HIT HEAT ADVISORY CRITERIA. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 AM EDT FRI JUN 29 2012 FOR THE MOST PART IT WILL BE HOT AND DRY. THERE IS A SYSTEM THAT MAY BRING SOME SHOWERS TO THE AREA TUESDAY INTO WEDNESDAY. THE PRIMARY ISSUE IS HOW HOT DOES IT GET? IS THE ECMWF MORE CORRECT THAN THE GFS IN TERMS OF THE UPPER AIR PATTERN? IF THE ECMWF IS CORRECT HIGHS WILL BE IN THE MID TO UPPER 90S MOST OF THIS COMING WEEK...WHILE IF THE GFS IS CORRECT IT WILL MORE LIKELY BE MID TO UPPER 80S. GIVEN THE RECENT POOR PERFORMANCE OF THE GFS FOR TEMPERATURES... THE 28TH 06Z MAV HAD 90F FOR GRR ON THURSDAY.... I WOULD HAVE TO SIDE WITH THE ECMWF MORE SO. AS FOR THE UPPER AIR PATTERN... BOTH MODELS SHOW THE OVERALL PATTERN NICELY AND SUGGEST LITTLE OVERALL CHANGE. THAT IS A LARGE NEARLY STATIONARY UPPER LEVEL HIGH CENTERED OVER THE CENTRAL CONUS AND TROUGHS ON BOTH THE WEST AND EAST COAST. THE PROBLEM COMES IN AS TO WERE THE POLAR JET WILL ACTUALLY BE? THE ECMWF HAS A MUCH FLATTER EASTERN TROUGH (KEEPS THE COOLER AIR WELL NORTH AND EAST OF SOUTHWEST MICHIGAN ALL WEEK) WHILE THE GFS HAS THIS FEATURE MUCH NEARER SOUTHWEST MICHIGAN. I AM FAVORING THE ECMWF AND IN SO DOING PUSHED OUR TEMPERATURE GRIDS IN THAT DIRECTION BUT ONLY BY A FEW DEGREES. AS FOR OUR SHOWERS IN THE TUESDAY/WEDNESDAY TIME FRAME THIS IS A SHORTWAVE TOPPING THE UPPER RIDGE. I WOULD LOOK FOR LIMITED CONVECTION AT BEST WITH THIS FEATURE AND MORE THAN LIKELY IT WOULD SPLIT AND MOST OF THE STORMS WILL GO SOUTH OF LOWER MICHIGAN OR OVER NORTHERN LOWER OR UPPER MICHIGAN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1150 PM EDT THU JUN 28 2012 VFR CONDITIONS THROUGH THE PERIOD WITH WEST TO NORTHWEST WINDS AT OR BELOW 10 KNOTS. SOME MVFR VISBYS MAY BE NOTED IN HAZE OVERNIGHT BUT THE CHANCE OF THIS IS LOW ENOUGH TO LEAVE OUT OF THE FORECAST AS DRIER AIR MOVES IN OVERNIGHT. && .MARINE... ISSUED AT 342 AM EDT FRI JUN 29 2012 RELATIVELY LIGHT WINDS WILL RESULT IN LOW WAVES TODAY. && .HYDROLOGY... ISSUED AT 342 AM EDT FRI JUN 29 2012 DRY WEATHER EXPECTED TODAY AND SATURDAY. A BETTER CHANCE OF STORMS EXISTS SUNDAY...BUT BASIN QPF WILL REMAIN QUITE LOW AND THE DRY CONDITIONS WILL PREVAIL. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...93 SHORT TERM...93 LONG TERM...WDM AVIATION...OSTUNO HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
254 AM CDT FRI JUN 29 2012 .SHORT TERM... ISSUED AT 250 AM CDT FRI JUN 29 2012 (TODAY AND TONIGHT) THE UNPRECEDENTED JUNE HEAT WAVE WILL CONTINUE. HAVE NOT DEVIATED MUCH FROM GOING HIGHS FOR TODAY WHICH ARE CLOSER TO THE WARMER NAM MOS TEMPERATURES WHICH HAVE BEEN VERIFYING BETTER RECENTLY THAN THE COOLER GFS VALUES. THE RAP IS SHOWING MIXING TO AROUND 800MB THIS AFTERNOON WITH SURFACE TEMPERATURES CLIMBING ABOVE +40C LIKE THEY DID ON THURSDAY AFTERNOON. DEWPOINTS HAVE RECOVERED SOME EARLY THIS MORNING...BUT DEEP MIXING THIS AFTERNOON SHOULD CAUSE THEM TO FALL OFF AGAIN TODAY. HAVE A SLIGHT CHANCE FOR THUNDERSTORMS LATE TONIGHT OVER A SMALL PART OF THE NORTHERN CWA. THERE WILL BE A WEAK SHORTWAVE MOVING ACROSS IOWA ALONG AN EXISTING FRONT THAT COULD CAUSE A FEW THUNDERSTORMS TO MOVE DOWN INTO NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS. THE DRY ATMOSPHERE WOULD SUPPORT FORWARD PROPAGATION WHICH WOULD TEND TO KEEP ANY COMPLEX OF THUNDERSTORMS MOVING EASTWARD WITH TIME. OTHERWISE...NAM MOS LOWS LOOK GOOD FOR TONIGHT. BRITT && .LONG TERM... ISSUED AT 250 AM CDT FRI JUN 29 2012 (SATURDAY THROUGH THURSDAY) HEAT ADVISORY WILL NOW BE EXTENDED THROUGH SUNDAY AS THERE WILL BE YET ANOTHER DAY WITH HEAT INDEX READINGS BETWEEN 100-105. WILL KEEP THE SLIGHT CHANCE FOR THUNDERSTORMS OVER NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS SATURDAY AND SATURDAY NIGHT AS A FRONT LINGERS OVER SOUTHERN IOWA INTO CENTRAL ILLINOIS. HOWEVER...THIS FRONT WILL MOVE BACK NORTH AS A WARM FRONT ON SUNDAY. MORE CLOUDS IN ADDITION TO THE SLIGHT CHANCE OF RAIN WILL LIKELY CAUSE THE AMBIENT TEMPERATURES TO BE SLIGHTLY LESS OVER NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS THAN WHAT THEY WHERE ON THURSDAY. HOWEVER...THERE WILL ALSO BE SLIGHTLY HIGHER DEWPOINTS BECAUSE OF MOISTURE POOLING WHICH WILL ONLY RAISE THE HEAT INDEX. FARTHER SOUTH...DEEP MIXING IN ADDITION...PLENTY OF SOLAR INSOLATION AND 850MB TEMPS IN THE 23-26 RANGE SUPPORT WIDESPREAD 100+ TEMPERATURES LIKE THE NAM MOS. NAM 2M TEMPS ARE IN THE 100-105F RANGE OVER MOST OF THE CWA TODAY THROUGH SUNDAY. MOST OF THE GUIDANCE ALSO INDICATES THERE SHOULD BE A SLOW CLIMB IN DEWPOINTS THROUGH THE WEEKEND. NEW GFS/ECMWF STILL LOOKS HOT AND DRY MOST OF NEXT WEEK AS UPPER HIGH OVER THE SOUTHERN ROCKIES BUILDS NORTHEAST INTO THE CENTRAL CONUS. 850MB TEMPS WILL REMAIN IN THE LOWER-MID 20S CELSIUS. BRITT && .AVIATION... ISSUED AT 1148 PM CDT THU JUN 28 2012 BOUNDARY THAT WAS DRAPED FROM S IA TO N IL EARLY THIS EVENING HAS BEEN MAKING VERY SLOW SWD PROGRESS...AND BELIEVE IT MAY CAUSE WINDS TO BE VARIABLE AT UIN FOR MUCH OF THE PREDAWN HOURS BEFORE RETREATING TO THE N ON FRIDAY MORNING. WITH SUCH WEAK CONVERGENCE AND INCREDIBLY WARM MID LEVEL TEMPS IT WOULD CERTAINLY APPEAR THAT ANY THREAT OF CONVECTION OVERNIGHT AND INTO FRIDAY WILL BE N OF THIS BOUNDARY. THE REMAINING TAF SITES IN OUR CWA WILL REMAIN IN THE UNSEASONABLY WARM AIRMASS...WITH MAINLY CLEAR SKIES AND SOUTHWEST WINDS GENLY AOB 12 KTS. SPECIFICS FOR KSTL... VFR CONDITIONS WILL PERSIST OVER THE AREA...WITH SW WINDS AOB 10 KTS. TRUETT && .FIRE WEATHER... ISSUED AT 250 AM CDT THU JUN 28 2012 NO CHANGE TO THINKING ABOUT A HEIGHTENED FIRE DANGER TODAY AS ONLY THE WIND STAYING BELOW 15 MPH WILL KEEP THE AREA FROM NEEDING A RED FLAG WARNING. MINIMUM RELATIVE HUMIDITY VALUES WILL BE AT OR BELOW 20 PERCENT OVER MUCH OF THE AREA AND FORECAST 10 HOUR DEAD FUELS WILL BE 5-6 PERCENT. EXPECT SIMILAR CONDITIONS OVER THE WEEKEND. WILL CONTINUE TO HIGHLIGHT IN THE FIRE WEATHER FORECAST... SPECIAL WEATHER STATEMENTS...AND HAZARDOUS WEATHER OUTLOOK. && .CLIMATE... ISSUED AT 330 AM CDT THU JUN 28 2012 RECORD HIGHS DATE ST. LOUIS COLUMBIA QUINCY ---------------------------------------------- JUNE 29 105(1952) 104(1901) 103(1934) JUNE 30 103(1931) 103(1901) 103(1931) JULY 01 105(1980) 110(1980) 104(1930) JULY 02 101(1933) 102(1901) 103(1934) JULY 03 101(1934) 104(1901) 104(1911) JULY 04 102(1990) 106(1901) 103(1936) JULY 05 102(1938) 105(1911) 104(1911) && .LSX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO- CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO- IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO- MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. IL...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR ADAMS IL-BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL- MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL- PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
444 AM EDT FRI JUN 29 2012 .SYNOPSIS... WEAK HIGH PRESSURE AND A BUILDING UPPER RIDGE WILL SPREAD WARM AIR INTO THE REGION...RESULTING IN ABOVE NORMAL TEMPERATURES AND MAINLY DRY WEATHER THROUGH THE WEEKEND. HOWEVER...WEAK DISTURBANCES PASSING THROUGH THE RIDGE EARLY THIS MORNING AND AGAIN ON SATURDAY...COULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... 4 AM UPDATE... SHOWERS AND THUNDERSTORMS MOVING ACROSS THE CWA ATTM. THESE BROUGHT ON BY UNSTABLE MID LAYERS AND SEVERAL SHORT WAVES. ALSO A SFC BOUNDARY. THIS WILL DIE SLOWLY AS IT MOVES ESE THROUGH THE AREA AND INTO NJ AND ERN NY BY 8 AM. AFTER THAT DRY AIR COMES IN AND NPV. WITH A LARGE LOW LEVEL CAP FEW IF ANY CLOUDS WILL FORM THIS AFTERNOON. WNW WINDS WILL PICK UP AND HELP WITH DRYING. DEWPOINT TEMPS FALL BACK INTO THE 50S. TONIGHT WITH BOUNDARY LEVEL WINDS UP AND MOST OF THE TWIN TIERS MISSING THE SHOWERS EARLY THIS MORNING...FOG WILL NOT BE WIDESPREAD LATE TONIGHT. FOR TEMPERATURES WENT CLOSE TO MOS WHICH HAS BEEN LESS THAN 2 DEGREES OFF LATELY. A FEW DEGREES WARMER TODAY OVER YESTERDAY FOR THE MAXES. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... 4 AM UPDATE... FAIRLY QUIET WITH WEAK DISTURBANCES MOVING THROUGH ON SATURDAY AND AGAIN LATE SUNDAY AND SUNDAY NIGHT. MODELS START TO DIVERGE ON SUNDAY ON STRENGTH AND LOCATION OF SYSTEMS AND PRECIP. FOR THE PERIOD REMAIN IN NW FLOW...WITH AN UPPER LEVEL TROF OVER THE NE US AND A LARGE RIDGE OVER THE PLAINS. A SHORT WAVE MOVES THROUGH SAT PM DIGGING THE NE US TROF A LITTLE DEEPER AND DROPPING TEMPERATURES SOME SO AFTER ANOTHER MID 80S TO A90 DEGREE DAY SATURDAY HIGHS SUNDAY WILL ONLY BE IN THE LOW AND MID 80S. THIS IS STILL ABOVE NORMAL. WITH DEWPOINTS FROM THE MID 50S TO THE LOW 60S NIGHTTIME TEMPERATURES WILL NOT FALL FAR. AGAIN WENT CLOSE TO MOS. SATURDAYS SHORT WAVE DROPS THROUGH PA SO BETTER CHANCES OF SHOWERS AND THUNDERSTORMS THERE. LATE SUNDAY AND SUNDAY NIGHT WENT WITH MORE OF A SLIGHT CHANCE OF SHOWERS AND TS EVERYWHERE GIVEN THE WIDE DIFFERENCES IN THE MODELS. BOTH DAYS NOT AS MUCH MODEL CONSENSUS AS EARLY THIS MORNING. ALSO THESE DISTURBANCES ARE WEAKER THAN NOW. && .LONG TERM /MONDAY THROUGH THURSDAY/... VERY FEW CHANGES MADE TO THE EXTENDED TIME FRAME AS MODEL AGREEMENT REMAINS LESS THAN FAVORABLE THROUGH THE PERIOD. IN GENERAL...THE UPPER-LEVEL PATTERN WILL BE DOMINATED BY CYCLONIC NORTHWEST FLOW ALOFT AS LONGWAVE BLOCKING ACROSS NORTH ATLANTIC PREVENTS EASTWARD PROGRESS OF AN EASTERN CANADIAN TROUGH. WITH THIS BEING THE CASE...AN ACTIVE BELT OF WESTERLIES WILL PREVAIL OVER OUR REGION WITH SEVERAL INDIVIDUAL SHORTWAVE DISTURBANCES EXPECTED TO TRANSLATE SOUTHEAST OVER OUR REGION. THE FIRST OF THESE SHORTWAVE FEATURES IS EXPECTED TO ARRIVE ON MONDAY...WHERE WE HAVE MAINTAINED A SLGT CHC MENTION FOR SHWRS/STORMS. FOLLOWING ITS DEPARTURE LATE MONDAY NIGHT...BRIEF SURFACE HIGH PRESSURE IS FORECAST TO SET IN WHICH SHOULD RESULT IN MAINLY DRY CONDITIONS ON TUESDAY. BY WEDNESDAY...THE ECMWF SHOWS A COLD FRONT/SFC LOW MOVING ACROSS THE REGION. UNFORTUNATELY THIS SOLUTION HAS VERY LITTLE SUPPORT FROM THE GFS WHICH MAINTAINS SFC HIGH PRESSURE ACROSS THE AREA. THAT SAID...BASED ON THE UNCERTAINTIES THIS FAR OUT...FELT BEST TO MAKE VERY FEW CHANGES AT THIS JUNCTURE. EXPECT NEAR TO SLIGHTLY ABOVE AVERAGE TEMPS THROUGH THE PERIOD AS WARM AIR ASSOCIATED WITH THE RECORD HEAT WAVE ACROSS THE NATION/S MIDSECTION REMAINS ACROSS THE LOWER OHIO VALLEY AND POINTS WEST. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... LATEST RADAR TRENDS SHOWING A LINE OF SHWRS/STORMS NOW MOVING ACROSS EASTERN LAKE ONTARIO. SOUTHEASTWARD MOVEMENT WILL PLACE THIS ACTIVITY OVER BOTH THE SYR AND RME TERMINALS SHORTLY. DRY LOW-LEVEL CONDITIONS SHOULD RESULT IN ONLY LGT SHWR ACTIVITY AND THUS WILL ONLY MENTION A TEMPO MVFR MENTION THROUGH 07Z AT BOTH SITES. ELSEWHERE...ISOLATED SHWRS NOW DEVELOPING OVER THE WESTERN SOUTHERN TIER OF NYS AS A SHORTWAVE CONTINUES TO DROP SOUTHEAST THROUGH THE AREA. BIGGEST QUESTION WILL BE WHETHER ACTIVITY WILL DEVELOPS AND MOVES OVER ELM. IF THIS WERE TO OCCUR...WE CANNOT RULE OUT TEMPORARY IFR CONDITIONS AFTER 08Z IN DEVELOPING FOG WITH MOISTENING LOW-LEVEL CONDITIONS. BASED ON ISOLATED NATURE OF THE ACTIVITY...ALONG WITH NEWLY ARRIVING HRRR SIMULATED REFLECTIVITY DATA...WE CURRENTLY DO NOT HAVE ENOUGH CONFIDENCE TO MENTION IFR AT THIS TIME. WILL CONTINUE TO MONITOR TRENDS HOWEVER. BEYOND THIS...EXPECT MOSTLY CLEAR SKIES THROUGH THE DAY WITH WEST WINDS BETWEEN 10-15 KTS POSSIBLY GUSTING TO NEAR 20 KTS DURING PEAK HEATING HRS. OUTLOOK... SAT...MAINLY VFR...AFTERNOON MVFR POSSIBLE AT ELM/ITH/BGM/AVP IN DEVELOPING SHWRS/STORMS. SUN...MAINLY VFR. MON/TUE...MAINLY VFR...HOWEVER ISOLATED MVFR CONDITIONS IN DEVELOPING -SHRA/TSRA ACTIVITY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...TAC NEAR TERM...TAC SHORT TERM...TAC LONG TERM...CMG/SLI AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
320 AM EDT FRI JUN 29 2012 .SYNOPSIS... WEAK HIGH PRESSURE AND A BUILDING UPPER RIDGE WILL SPREAD WARM AIR INTO THE REGION...RESULTING IN ABOVE NORMAL TEMPERATURES AND MAINLY DRY WEATHER THROUGH THE WEEKEND. HOWEVER...WEAK DISTURBANCES PASSING THROUGH THE RIDGE OVERNIGHT AND AGAIN ON SATURDAY...COULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS IN THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1230 AM UPDATE... MINOR CHANGES AT THIS TIME TO THE GRIDS. WATCHING UPSTREAM AT THE CONVECTION. AREA IN NW PA SHOULD PASS SOUTH OF THE CWA WHILE CONVECTION OVER LAKE ONTARIO SHOULD JUST BRUSH THE FAR NORTH WITH SHOWERS. BOTH AREAS ARE MOVING INTO MORE STABLE AIR. CONVECTION BEING FORCED BY 3 SEPARATE SHORT WAVES AHEAD OF A WIND SHIFT LINE. THE HRR HAS THE BEST HANDLE ON THE CONVECTION ATTM. IT BRINGS BOTH AREAS EAST AND JOINS THEM WITH SHOWERS IN BETWEEN THAT MOVE THROUGH THE CWA BETWEEN 2 AND 7 AM. FOR NOW HAVE LEFT THE 20 POPS BUT MAY NEED TO UP THE POPS IF THIS PANS OUT. 830 PM UPDATE...MAIN TWEAK FOR THE EVNG UPDATE WILL BE TO LOWER CHC POPS TO SLGT CHC FOR THE OVRNGT PD. PERUSAL OF 00Z BUF/DET SNDGS SHOW WELL DEFINED EML WHICH IS CAPPING CONVECTIVE DVLPMNT ACRS THE FCST AREA. WEAK CELL HAS DVLPD NEAR DTX IN THE PAST HR IN AREA OF RELATIVELY WEAKER INHIBITION BUT THAT`S IT THUS FAR. GIVEN AXIS OF L70 TD`S WITH THE FNT AND THE ADDNL SUPPORT OF A S/WV WHICH WILL BE PASSING LATER TNGT WILL LEAVE IN A SLGT CHC TNGT FOR POTNL ISOLD ACTIVITY...BUT XPCT ANY ORGANIZED CONVECTION (IF IT DVLPS) TO BE SHUNTED TO OUR S AND W. WE ALSO RAISED MINS BY A FEW DEG. PREV BLO... 530 PM UPDATE...MINOR T/TD/SKY TWEEKS OTRW NO CHGS. PERUSAL OF LAPS AND ACARS PROFILES ALONG WITH SFC AND BL CIN ANYLS INDICATES A STRONG CAP WHICH WILL MAKE IT DIFFICULT TO INITIATE CONVECTION OVRNGT. BAND OF L70`S TD`S IS WORKING ACRS MI VCNTY OF FNT AND THERE IS A SUPPORTING S/WV...BUT BEST CHC FOR DVLPMNT BASED ON WEAKEST FCST CIN APPEARS TO BE FROM SE MI INTO THE WRN PORTIONS OF PA. WILL CONSIDER LOWERING POPS FOR THE OVRNGT PD IN THE LATE EVNG UPDATE. PREV BLO... 2 PM UPDATE... CONFIDENCE IS DECREASING THAT ORGANIZED CONVECTION WILL OCCUR OVERNIGHT TONIGHT...AS A WEAK VORTICITY WAVE PASSES NORTHWEST TO SOUTHEAST. MODEL CONSENSUS CONTINUES TO FOCUS MORE ON CENTRAL PA INSTEAD OF NE PA/CENTRAL NY FOR BETTER FORCING. I HAVE BACKED OFF TO SLIGHT TO LOW CHANCE POPS...HIGHEST IN OUR SOUTHEASTERN ZONES. FOR WHAT SMALL POPS WE HAVE...I ALSO HONED IN ON THE TIMING TO EXPECTED PASSAGE OF SHORTWAVE AROUND 05Z-11Z. SURPRISINGLY STEEP LAPSE RATES AND A GOOD AMOUNT OF INSTABILITY WILL OCCUR ABOVE THE 600MB LEVEL...BUT WITH SO MUCH DRY AIR AND SIGNIFICANT CONVECTIVE INHIBITION BELOW THAT LAYER...WITH ABSENCE OF REALLY GOOD FORCING IT IS APPEARING THAT ORGANIZED CONVECTION WILL BE DIFFICULT TO GENERATE IN OUR AREA. SPEAKING OF DRY AIR...PRECIPITABLE WATER VALUES REALLY TANK BEHIND THE WAVE ON FRIDAY...REACHING A WAYS BELOW THREE-QUARTERS OF AN INCH DURING THE AFTERNOON. OTHER THAN A QUICK LOW CHANCE OF LINGERING EARLY MORNING SHOWER/THUNDERSTORM IN THE SOUTHEASTERN ZONES AS THE WAVE EXITS...LOOKING AT A DRY DAY WITH ABOVE NORMAL TEMPERATURES AS THE CONVECTIVE INHIBITION CAP STRENGTHENS. GOOD MIXING DOWN OF WARM DRY AIR WILL WIDEN THE DIURNAL RANGE TO THE POINT THAT MUCH OF THE LOWER ELEVATIONS...ESPECIALLY IN THE CENTRAL TO SOUTHERN ZONES...WILL PROBABLY PUSH 90 DEGREES. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... SURFACE HIGH PRESSURE WILL BE IN PLACE FRIDAY NIGHT, KEEPING THE WEATHER QUIET. FOR SATURDAY...THE SFC HIGH WILL BREAKDOWN SOMEWHAT AND THERE WILL BE AN UPPER LEVEL TROUGH IN PLACE, ALONG WITH A SHORT WAVE MOVING ACROSS THE AREA. MODEL SOUNDINGS DO SHOW A WEAK UPPER LEVEL CAP. THE GFS SHOWS ALMOST NO CAPE OVER THE CWA SATURDAY, BUT THE NAM SHOWS BETWEEN 500 AND 1500 JOULES OVER THE AREA. WITH THE MODEL DISCREPANCY BEING SO LARGE, HAVE ONLY A HIGH SLIGHT CHC OP IN THE FORECAST FOR SHOWERS AND THUNDERSTORMS. THE SHORTWAVE SHOULD BE THROUGH THE CWA BY THE EVENING. THIS AND THE LOSS OF DAYTIME HEATING WILL ALLOW THE WEATHER TO QUIET DOWN AND/OR MOVE OFF TO THE EAST BY SATURDAY EVENING. SUNDAY IS LOOKING QUIETER, ESPECIALLY WITH THE MODELS SHOWING MUCH LESS CAPE OVER THE CWA AS A WHOLE, ALTHOUGH THEY ARE SHOWING 700 TO 900 JOULES OVER NEPA. SO, HAVE A MENTION OF AFTERNOON SHOWERS AND THUNDERSTORMS FOR THAT AREA. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... VERY FEW CHANGES MADE TO THE EXTENDED TIME FRAME AS MODEL AGREEMENT REMAINS LESS THAN FAVORABLE THROUGH THE PERIOD. IN GENERAL...THE UPPER-LEVEL PATTERN WILL BE DOMINATED BY CYCLONIC NORTHWEST FLOW ALOFT AS LONGWAVE BLOCKING ACROSS NORTH ATLANTIC PREVENTS EASTWARD PROGRESS OF AN EASTERN CANADIAN TROUGH. WITH THIS BEING THE CASE...AN ACTIVE BELT OF WESTERLIES WILL PREVAIL OVER OUR REGION WITH SEVERAL INDIVIDUAL SHORTWAVE DISTURBANCES EXPECTED TO TRANSLATE SOUTHEAST OVER OUR REGION. THE FIRST OF THESE SHORTWAVE FEATURES IS EXPECTED TO ARRIVE ON MONDAY...WHERE WE HAVE MAINTAINED A SLGT CHC MENTION FOR SHWRS/STORMS. FOLLOWING ITS DEPARTURE LATE MONDAY NIGHT...BRIEF SURFACE HIGH PRESSURE IS FORECAST TO SET IN WHICH SHOULD RESULT IN MAINLY DRY CONDITIONS ON TUESDAY. BY WEDNESDAY...THE ECMWF SHOWS A COLD FRONT/SFC LOW MOVING ACROSS THE REGION. UNFORTUNATELY THIS SOLUTION HAS VERY LITTLE SUPPORT FROM THE GFS WHICH MAINTAINS SFC HIGH PRESSURE ACROSS THE AREA. THAT SAID...BASED ON THE UNCERTAINTIES THIS FAR OUT...FELT BEST TO MAKE VERY FEW CHANGES AT THIS JUNCTURE. EXPECT NEAR TO SLIGHTLY ABOVE AVERAGE TEMPS THROUGH THE PERIOD AS WARM AIR ASSOCIATED WITH THE RECORD HEAT WAVE ACROSS THE NATION/S MIDSECTION REMAINS ACROSS THE LOWER OHIO VALLEY AND POINTS WEST. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... LATEST RADAR TRENDS SHOWING A LINE OF SHWRS/STORMS NOW MOVING ACROSS EASTERN LAKE ONTARIO. SOUTHEASTWARD MOVEMENT WILL PLACE THIS ACTIVITY OVER BOTH THE SYR AND RME TERMINALS SHORTLY. DRY LOW-LEVEL CONDITIONS SHOULD RESULT IN ONLY LGT SHWR ACTIVITY AND THUS WILL ONLY MENTION A TEMPO MVFR MENTION THROUGH 07Z AT BOTH SITES. ELSEWHERE...ISOLATED SHWRS NOW DEVELOPING OVER THE WESTERN SOUTHERN TIER OF NYS AS A SHORTWAVE CONTINUES TO DROP SOUTHEAST THROUGH THE AREA. BIGGEST QUESTION WILL BE WHETHER ACTIVITY WILL DEVELOPS AND MOVES OVER ELM. IF THIS WERE TO OCCUR...WE CANNOT RULE OUT TEMPORARY IFR CONDITIONS AFTER 08Z IN DEVELOPING FOG WITH MOISTENING LOW-LEVEL CONDITIONS. BASED ON ISOLATED NATURE OF THE ACTIVITY...ALONG WITH NEWLY ARRIVING HRRR SIMULATED REFLECTIVITY DATA...WE CURRENTLY DO NOT HAVE ENOUGH CONFIDENCE TO MENTION IFR AT THIS TIME. WILL CONTINUE TO MONITOR TRENDS HOWEVER. BEYOND THIS...EXPECT MOSTLY CLEAR SKIES THROUGH THE DAY WITH WEST WINDS BETWEEN 10-15 KTS POSSIBLY GUSTING TO NEAR 20 KTS DURING PEAK HEATING HRS. OUTLOOK... SAT...MAINLY VFR...AFTERNOON MVFR POSSIBLE AT ELM/ITH/BGM/AVP IN DEVELOPING SHWRS/STORMS. SUN...MAINLY VFR. MON/TUE...MAINLY VFR...HOWEVER ISOLATED MVFR CONDITIONS IN DEVELOPING -SHRA/TSRA ACTIVITY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP/TAC SHORT TERM...SLI LONG TERM...CMG/SLI AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
152 AM EDT FRI JUN 29 2012 .SYNOPSIS... WEAK HIGH PRESSURE AND A BUILDING UPPER RIDGE WILL SPREAD WARM AIR INTO THE REGION...RESULTING IN ABOVE NORMAL TEMPERATURES AND MAINLY DRY WEATHER THROUGH THE WEEKEND. HOWEVER...WEAK DISTURBANCES PASSING THROUGH THE RIDGE OVERNIGHT AND AGAIN ON SATURDAY...COULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS IN THE REGION. && .NEAR TERM /THROUGH TODAY/... 1230 AM UPDATE... MINOR CHANGES AT THIS TIME TO THE GRIDS. WATCHING UPSTREAM AT THE CONVECTION. AREA IN NW PA SHOULD PASS SOUTH OF THE CWA WHILE CONVECTION OVER LAKE ONTARIO SHOULD JUST BRUSH THE FAR NORTH WITH SHOWERS. BOTH AREAS ARE MOVING INTO MORE STABLE AIR. CONVECTION BEING FORCED BY 3 SEPARATE SHORT WAVES AHEAD OF A WIND SHIFT LINE. THE HRR HAS THE BEST HANDLE ON THE CONVECTION ATTM. IT BRINGS BOTH AREAS EAST AND JOINS THEM WITH SHOWERS IN BETWEEN THAT MOVE THROUGH THE CWA BETWEEN 2 AND 7 AM. FOR NOW HAVE LEFT THE 20 POPS BUT MAY NEED TO UP THE POPS IF THIS PANS OUT. 830 PM UPDATE...MAIN TWEAK FOR THE EVNG UPDATE WILL BE TO LOWER CHC POPS TO SLGT CHC FOR THE OVRNGT PD. PERUSAL OF 00Z BUF/DET SNDGS SHOW WELL DEFINED EML WHICH IS CAPPING CONVECTIVE DVLPMNT ACRS THE FCST AREA. WEAK CELL HAS DVLPD NEAR DTX IN THE PAST HR IN AREA OF RELATIVELY WEAKER INHIBITION BUT THAT`S IT THUS FAR. GIVEN AXIS OF L70 TD`S WITH THE FNT AND THE ADDNL SUPPORT OF A S/WV WHICH WILL BE PASSING LATER TNGT WILL LEAVE IN A SLGT CHC TNGT FOR POTNL ISOLD ACTIVITY...BUT XPCT ANY ORGANIZED CONVECTION (IF IT DVLPS) TO BE SHUNTED TO OUR S AND W. WE ALSO RAISED MINS BY A FEW DEG. PREV BLO... 530 PM UPDATE...MINOR T/TD/SKY TWEEKS OTRW NO CHGS. PERUSAL OF LAPS AND ACARS PROFILES ALONG WITH SFC AND BL CIN ANYLS INDICATES A STRONG CAP WHICH WILL MAKE IT DIFFICULT TO INITIATE CONVECTION OVRNGT. BAND OF L70`S TD`S IS WORKING ACRS MI VCNTY OF FNT AND THERE IS A SUPPORTING S/WV...BUT BEST CHC FOR DVLPMNT BASED ON WEAKEST FCST CIN APPEARS TO BE FROM SE MI INTO THE WRN PORTIONS OF PA. WILL CONSIDER LOWERING POPS FOR THE OVRNGT PD IN THE LATE EVNG UPDATE. PREV BLO... 2 PM UPDATE... CONFIDENCE IS DECREASING THAT ORGANIZED CONVECTION WILL OCCUR OVERNIGHT TONIGHT...AS A WEAK VORTICITY WAVE PASSES NORTHWEST TO SOUTHEAST. MODEL CONSENSUS CONTINUES TO FOCUS MORE ON CENTRAL PA INSTEAD OF NE PA/CENTRAL NY FOR BETTER FORCING. I HAVE BACKED OFF TO SLIGHT TO LOW CHANCE POPS...HIGHEST IN OUR SOUTHEASTERN ZONES. FOR WHAT SMALL POPS WE HAVE...I ALSO HONED IN ON THE TIMING TO EXPECTED PASSAGE OF SHORTWAVE AROUND 05Z-11Z. SURPRISINGLY STEEP LAPSE RATES AND A GOOD AMOUNT OF INSTABILITY WILL OCCUR ABOVE THE 600MB LEVEL...BUT WITH SO MUCH DRY AIR AND SIGNIFICANT CONVECTIVE INHIBITION BELOW THAT LAYER...WITH ABSENCE OF REALLY GOOD FORCING IT IS APPEARING THAT ORGANIZED CONVECTION WILL BE DIFFICULT TO GENERATE IN OUR AREA. SPEAKING OF DRY AIR...PRECIPITABLE WATER VALUES REALLY TANK BEHIND THE WAVE ON FRIDAY...REACHING A WAYS BELOW THREE-QUARTERS OF AN INCH DURING THE AFTERNOON. OTHER THAN A QUICK LOW CHANCE OF LINGERING EARLY MORNING SHOWER/THUNDERSTORM IN THE SOUTHEASTERN ZONES AS THE WAVE EXITS...LOOKING AT A DRY DAY WITH ABOVE NORMAL TEMPERATURES AS THE CONVECTIVE INHIBITION CAP STRENGTHENS. GOOD MIXING DOWN OF WARM DRY AIR WILL WIDEN THE DIURNAL RANGE TO THE POINT THAT MUCH OF THE LOWER ELEVATIONS...ESPECIALLY IN THE CENTRAL TO SOUTHERN ZONES...WILL PROBABLY PUSH 90 DEGREES. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... SURFACE HIGH PRESSURE WILL BE IN PLACE FRIDAY NIGHT, KEEPING THE WEATHER QUIET. FOR SATURDAY...THE SFC HIGH WILL BREAKDOWN SOMEWHAT AND THERE WILL BE AN UPPER LEVEL TROUGH IN PLACE, ALONG WITH A SHORT WAVE MOVING ACROSS THE AREA. MODEL SOUNDINGS DO SHOW A WEAK UPPER LEVEL CAP. THE GFS SHOWS ALMOST NO CAPE OVER THE CWA SATURDAY, BUT THE NAM SHOWS BETWEEN 500 AND 1500 JOULES OVER THE AREA. WITH THE MODEL DISCREPANCY BEING SO LARGE, HAVE ONLY A HIGH SLIGHT CHC OP IN THE FORECAST FOR SHOWERS AND THUNDERSTORMS. THE SHORTWAVE SHOULD BE THROUGH THE CWA BY THE EVENING. THIS AND THE LOSS OF DAYTIME HEATING WILL ALLOW THE WEATHER TO QUIET DOWN AND/OR MOVE OFF TO THE EAST BY SATURDAY EVENING. SUNDAY IS LOOKING QUIETER, ESPECIALLY WITH THE MODELS SHOWING MUCH LESS CAPE OVER THE CWA AS A WHOLE, ALTHOUGH THEY ARE SHOWING 700 TO 900 JOULES OVER NEPA. SO, HAVE A MENTION OF AFTERNOON SHOWERS AND THUNDERSTORMS FOR THAT AREA. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE LONG TERM PATTERN DOES NOT CHANGE MUCH. MAINLY IN NW FLOW ALOFT, WITH SEVERAL WEAK SHORT WAVES MOVING THROUGH THE FLOW. THIS COULD CAUSE AFTERNOON SHOWERS AND THUNDERSTORMS FOR MONDAY AND THURSDAY. WEDNESDAY DOES LOOK QUIET FOR NOW, ALTHOUGH THERE IS DIFFERENCES IN THE GFS AND THE ECMWF. THE ECMWF DOES HAVE AN MCS TYPE FEATURE MOVING ACROSS NORTHERN NY TUESDAY NIGHT. THE GFS DOES NOT HAVE THIS. RATHER, IT SHOWS AN UPPER LEVEL RIDGE TRYING TO BUILD OVER THE AREA. SO, HAVE KEPT TUESDAY NIGHT AND WEDNESDAY QUIET FOR NOW. FOR THURSDAY, THE MODELS SWITCH PLACES. THE ECMWF HAS THE RIDGE BUILDING AND THE GFS HAS A LOW SKIRTING NORTHERN NY BY THURSDAY AFTERNOON. HAVE OPTED TO HAVE A MENTION OF SHOWERS IN THE FORECAST THIS FAR OUT. TIMING WILL MAKE THE LARGEST DIFFERENCE WITH PRECIPITATION, AS WELL AS FOR ANY CHANCE OF CONVECTION. THE IS LOW CONFIDENCE IN THE FORECAST FROM TUESDAY NIGHT ON AT THIS TIME. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... LATEST RADAR TRENDS SHOWING A LINE OF SHWRS/STORMS NOW MOVING ACROSS EASTERN LAKE ONTARIO. SOUTHEASTWARD MOVEMENT WILL PLACE THIS ACTIVITY OVER BOTH THE SYR AND RME TERMINALS SHORTLY. DRY LOW-LEVEL CONDITIONS SHOULD RESULT IN ONLY LGT SHWR ACTIVITY AND THUS WILL ONLY MENTION A TEMPO MVFR MENTION THROUGH 07Z AT BOTH SITES. ELSEWHERE...ISOLATED SHWRS NOW DEVELOPING OVER THE WESTERN SOUTHERN TIER OF NYS AS A SHORTWAVE CONTINUES TO DROP SOUTHEAST THROUGH THE AREA. BIGGEST QUESTION WILL BE WHETHER ACTIVITY WILL DEVELOPS AND MOVES OVER ELM. IF THIS WERE TO OCCUR...WE CANNOT RULE OUT TEMPORARY IFR CONDITIONS AFTER 08Z IN DEVELOPING FOG WITH MOISTENING LOW-LEVEL CONDITIONS. BASED ON ISOLATED NATURE OF THE ACTIVITY...ALONG WITH NEWLY ARRIVING HRRR SIMULATED REFLECTIVITY DATA...WE CURRENTLY DO NOT HAVE ENOUGH CONFIDENCE TO MENTION IFR AT THIS TIME. WILL CONTINUE TO MONITOR TRENDS HOWEVER. BEYOND THIS...EXPECT MOSTLY CLEAR SKIES THROUGH THE DAY WITH WEST WINDS BETWEEN 10-15 KTS POSSIBLY GUSTING TO NEAR 20 KTS DURING PEAK HEATING HRS. OUTLOOK... SAT...MAINLY VFR...AFTERNOON MVFR POSSIBLE AT ELM/ITH/BGM/AVP IN DEVELOPING SHWRS/STORMS. SUN...MAINLY VFR. MON/TUE...MAINLY VFR...HOWEVER ISOLATED MVFR CONDITIONS IN DEVELOPING -SHRA/TSRA ACTIVITY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP/TAC SHORT TERM...SLI LONG TERM...SLI AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
350 AM CDT FRI JUN 29 2012 .SHORT TERM...TODAY THROUGH SATURDAY... LATEST WATER VAPOR IMAGERY SHOWS A PROGRESSIVE FLOW FROM THE PACIFIC INTO THE NORTHERN PLAINS. BROAD RIDGING OVERHEAD WITH EMBEDDED SHORTWAVES SLIDING THROUGH EASTERN MONTANA AND INTO THE DAKOTAS TODAY THROUGH SATURDAY WILL SET THE STAGE FOR A CHANCE OF SHOWERS AND THUNDERSTORMS. FORECAST CONCERNS CONTINUE TO BE THUNDERSTORM CHANCES AND SEVERE WEATHER POTENTIAL IN THE SOUTHWEST TO FAR SOUTH CENTRAL ZONES TODAY...THEN SHIFTING INTO OUR EAST CENTRAL ZONES/JAMES RIVER VALLEY SATURDAY. ONE SHORTWAVE IS NOW APPROACHING MILES CITY MONTANA AND CONTINUED TO GENERATE AN AREA OF LIGHT SHOWERS/ISOLATED THUNDERSTORMS. MILES CITY REPORTED A TRACE RECENTLY. WILL CONTINUE WITH THE ISOLATED SHOWER/THUNDERSTORM WORDING IN OUR FAR WESTERN AND SOUTHWESTERN ZONES THROUGH THE MORNING. THE HRRR IS PERSISTENT IN RAMPING UP THIS AREA OF PRECIPITATION AS IT MOVES ALONG OUR SOUTHERN BORDER BETWEEN 12Z AND 16Z THIS MORNING...SO WILL NEED TO MONITOR THIS CLOSELY. ANOTHER SHORTWAVE IS FORECAST TO MOVE ACROSS SOUTHERN CANADA AND TOP THE RIDGE IN EASTERN MONTANA AND NORTHERN NORTH DAKOTA LATER THIS AFTERNOON THROUGH SATURDAY. IN DOING SO A FRONT WILL DEVELOP/EMERGE IN EASTERN MONTANA THIS AFTERNOON WITH INSTABILITY INCREASING IN THE SOUTHWEST. THE INSTABILITY AXIS IS FORECAST FROM HETTINGER TO BOWMAN AND BEACH FRIDAY AFTERNOON...RIGHT ALONG AND AHEAD OF A FRONTAL ZONE IN EASTERN MONTANA. 0-6KM SHEAR OF 35KT TO 40KT IN A POSSIBLY HIGH CAPE ENVIRONMENT OF 2000 J/KG COULD YIELD ENOUGH ORGANIZATION FOR A WIND/HAIL THREAT IN THE SOUTHWEST. THE GFS IS MORE ROBUST WITH THIS IDEA THAN THE NAM WHICH IS MORE CAPPED. IN ANY CASE THIS WOULD BE THE FAVORED AREA FOR SEVERE WEATHER IF IT DEVELOPS THIS AFTERNOON THROUGH THE EVENING. OTHERWISE THE SHORTWAVE WILL SLIDE ACROSS NORTHERN NORTH DAKOTA TONIGHT PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS. THIS SHORTWAVE AND ASSOCIATED INSTABILITY AREA WILL BE THE FOCUS FOR MORE SHOWERS AND THUNDERSTORMS OVER EAST CENTRAL NORTH DAKOTA. THE JAMES RIVER VALLEY WOULD BE THE MOST TARGET PRONE AREA FOR SEVERE WEATHER SATURDAY AND THIS IS HIGHLIGHTED IN THE SPC DAY TWO CONVECTIVE OUTLOOK. EXPECT HOT AND HUMID WEATHER THROUGH FRIDAY WITH HIGHS IN THE 80S TO LOWER 90S AND DEWPOINTS IN THE 50S TO LOWER 60S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY... NORTH DAKOTA WILL REMAIN ON THE NORTHERN EDGE OF AN UPPER LEVEL RIDGE SITUATED OVER THE SOUTHERN AND CENTRAL U.S. A PERSISTENT UPPER TROUGH IS SITUATED OVER THE PACIFIC NORTHWEST AND THE MAIN FORECAST PROBLEM IN THE LONG TERM PERIOD WILL BE RESOLVING THE SHORTWAVES TRAVELING THROUGH THE MEAN TROUGH AND TRACKING ACROSS THE NORTHERN PLAINS. MODELS ARE IN AGREEMENT THAT SATURDAY NIGHT AND SUNDAY SHOULD BE DRY WITH SURFACE HIGH PRESSURE TRACKING ACROSS THE AREA AND UPPER LEVEL RIDGING BUILDING INTO THE NORTHERN PLAINS. BY SUNDAY NIGHT AND POSSIBLY AS EARLY AS LATE SUNDAY AFTERNOON IN THE FAR WEST...MOISTURE RETURN AHEAD OF AND APPROACHING SURFACE TROUGH AND AN APPROACHING MID LEVEL WAVE WILL BRING INCREASED CHANCES OF CONVECTION TO THE LOCAL AREA SUNDAY NIGHT THROUGH MONDAY NIGHT. TEMPERATURES ALOFT WILL BE WARM AHEAD OF THE TROUGH AND MAY PROVIDE ENOUGH OF A CAP TO INHIBIT CONVECTION. THE ECMWF/GEM ARE TRENDING TOWARDS THIS SOLUTION...KEEPING THE MAJORITY OF THE CONVECTION CONFINED TO OUR NORTHERN TIER COUNTIES AND SOUTHERN CANADA. THE GFS SHOW A STRONGER SHORTWAVE INITIATING CONVECTION OVER CENTRAL NORTH DAKOTA MONDAY AFTERNOON. ALTHOUGH A STORM CANNOT BE RULED OUT ON TUESDAY...THE BETTER CHANCE FOR THUNDERSTORMS LOOKS TO BE WEDNESDAY (JULY 4) AND THURSDAY...AS ANOTHER UPPER LEVEL SHORTWAVE AND DEVELOPING SURFACE LOW OVER THE CENTRAL/NORTHERN PLAINS BRING INCREASING LOW LEVEL HUMIDITY AND INCREASING INSTABILITY. MODELS STILL DIFFER ON THE EXACT TIMING/PLACEMENT OF SYNOPTIC FEATURES...BUT AGREE ENOUGH TO BUMP UP POPS TO CHANCE CATEGORY WEDNESDAY AND WEDNESDAY NIGHT. THE PERSISTENT BROAD SOUTHWEST FLOW AND SURFACE LOW OVER THE NORTHERN PLAINS RILL REMAIN THROUGH THURSDAY...KEEPING A CHANCE OF STORMS IN THE FORECAST. TEMPERATURES THROUGH THE PERIOD WILL REMAIN ABOVE NORMAL WITH HIGHS IN THE MID 80S NORTH TO THE LOW TO MID 90S SOUTH AND LOWS GENERALLY IN THE 60S. && .AVIATION...CURRENTLY HIGH PRESSURE IS SITUATED OVER NORTHEAST MONTANA INTO CENTRAL NORTH DAKOTA WITH WEAK LOW PRESSURE OVER SOUTHEAST MONTANA INTO NORTHWEST SOUTH DAKOTA. A SHORTWAVE TRACKING ACROSS SOUTHEAST MONTANA IS PRODUCING SOME MID LEVEL CLOUDINESS AND SCATTERED SHOWERS. THE HRRR AND TO A LESSER EXTENT THE RAP AND NAM INDICATE THIS PRECIPITATION HOLDING TOGETHER AS IT TRACKS ACROSS SOUTHERN NORTH DAKOTA THIS MORNING. WILL BRING A MENTION OF MID LEVEL CLOUDS AND POSSIBLY VCSH TO THE SOUTHERN TAF SITES THIS MORNING. THE NORTH SHOULD REMAIN SUNNY. TONIGHT A FRONTAL BOUNDARY WILL MOVE INTO WESTERN NORTH DAKOTA WITH SOUTHEAST FLOW REMAINING OVER CENTRAL NORTH DAKOTA. THUNDERSTORM CHANCES WILL INCREASE LATE TONIGHT OVER THE WEST AND NORTH CENTRAL. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KS LONG TERM/AVIATION....TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1141 PM CDT THU JUN 28 2012 .DISCUSSION...LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE NOW NEAR LIVINGSTON MONTANA MOVING EAST. THE 00Z NAM/GFS APPEAR TO HAVE INITIALIZED THIS SHORTWAVE A BIT TOO FAR SOUTH...RESULTING IN A DISPLACEMENT OF THE ACTUAL RADAR ECHOES VERSUS MODEL OUTPUT. THE HRRR SEEMS TO HAVE A BETTER HANDLE ON THE TRAJECTORY OF THE WAVE AND HENCE THE PRECIPITATION AREA/TRENDS OVERNIGHT. AS A RESULT...HAVE FOLLOWED THE HRRR AND ADJUSTED POPS TO INCLUDE A SLIGHT CHC OF SHOWERS/THUNDERSTORMS FURTHER NORTH...ENCOMPASSING WESTERN MCKENZIE COUNTY SOUTH INTO BOWMAN AND EAST INTO SIOUX COUNTY. SLIGHT CHC OF POPS WERE ALREADY COVERED IN BOWMAN AND POINTS EAST FROM EARLIER. THE THREAT OF PRECIPITATION LOOKS MAINLY BETWEEN 09Z AND 12Z. MINOR ADJUSTMENTS TO HOURLY TEMPS. REST OF FORECAST REMAINS ON TRACK. && .AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. EXPECT A LIGHT AND VARIABLE WIND OVERNIGHT...BECOMING NE ON FRIDAY WITH SCATTERED MID TO HIGH LEVEL CLOUDS. ANY ISOLATED PRECIPITATION OVERNIGHT INTO FRIDAY MORNING IS EXPECTED TO REMAIN SOUTH OF TAF SITES...ALTHOUGH THERE WILL BE SOME CHANCE OF PRECIPITATION IMPACTING KDIK DURING THE AFTERNOON HOURS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KS AVIATION...RK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
413 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WEAK COLD FRONT WILL SINK SLOWLY SOUTH TOWARD THE OHIO RIVER VALLEY TODAY. A WEAK AREA OF LOW PRESSURE WILL MOVE ACROSS THE REGION ON SATURDAY AND A LOW WILL MOVE ACROSS THE GREAT LAKES ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ISSUED A HEAT ADVISORY FOR THE WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA. EVEN THOUGH A COLD FRONT HAS MOVES THROUGH...TEMPERATURES WILL RECOVER ESPECIALLY AWAY FROM INFLUENCES OF LAKE ERIE. LOCATIONS IN THE HEAT ADVISORY WILL COME CLOSE TO HEAT INDEX VALUES OF 100. AFTER A VERY WARM NIGHT...TEMPERATURES WILL HEAT UP QUICKLY. WENT WARMER THAN GUIDANCE...USED A MIX OF PRODUCTS. THE POP FORECAST IS TOUGH. THE HRRR MODEL IS TRYING TO INDICATE SOME SHOWERS MOVING THROUGH THE SOUTHERN PORTION OF THE FORECAST ARE TODAY. ON THE EDGE ABOUT THAT. WENT WITH SLIGHT CHANCE POPS WITH THE BOUNDARY SO CLOSE TO THAT AREA. FIRE WEATHER THREAT IS MUCH LOWER TODAY WITH HIGHER HUMIDITIES AND LIGHTER WINDS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE FORECAST IS VERY TOUGH TRYING TO TIME PRECIPITATION. WENT CLOSE TO PREVIOUS FORECAST...A THREAT TONIGHT AS AN MCS MAY COME OUT OF THE MIDWEST AND THEN THE THREAT CONTINUES SATURDAY INTO SUNDAY. A WAVE MOVES ALONG THE FRONT SATURDAY AND THEN A LOW MOVES ACROSS THE GREAT LAKES SUNDAY. WENT ON THE WARMER SIDE OF GUIDANCE. AT THIS TIME NOT EXPECTING TO MEET HEAT ADVISORY CRITERIA DURING THIS PERIOD. && .LONG TERM /TUESDAY THROUGH THURSDAY/... EXTENDED PERIODS COULD BE INTERESTING AS MODELS CONTINUE TO PLACE A STATIONARY FRONT NORTHWEST TO SOUTHEAST ACROSS THE AREA TUESDAY THROUGH THURSDAY MORNING. THIS IS A BIT CONCERNING DUE TO THE SERIES OF UPPER LEVEL POSITIVE VORTICITY MAXIMUMS ROTATING SOUTHEAST ON THE EAST SIDE OF THE UPPER LEVEL RIDGE. THIS COULD POSSIBLY TRANSLATE INTO A PERIOD OF ONE MESO CONVECTIVE SYSTEM AFTER ANOTHER AFFECTING THE FORECAST AREA. WILL HAVE TO MONITOR THE SITUATION TO SEE HOW THINGS DEVELOP. THERE HAS BEEN SOME CONSISTENCY IN THE OVERALL PATTERN OVER THE LAST FEW MODEL RUNS. THE OTHER ISSUE TO DEAL WITH IS THE SUMMER HEAT CONTINUES. INITIALLY...THE STATIONARY FRONT SETS UP ON MONDAY AND REMAINS THERE THROUGH THURSDAY. THIS FRONTAL BOUNDARY COULD MEAN A SPLIT BETWEEN RELIEF FROM THE HOT TEMPERATURES EAST TO CONTINUED HOT TEMPERATURES WEST. WILL MAKE ONLY SOME MINOR ADJUSTMENTS IN TEMPERATURES THROUGH THE EXTENDED PERIODS. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... CONVECTION THAT DEVELOPED OVER NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA CONTINUES TO MOVE SOUTHEAST AS IT DEVELOPS INTO AN MESO CONVECTIVE SYSTEM. THIS CLUSTER OF STORMS WAS ASSOCIATED WITH A RATHER POTENT VORTICITY MAXIMUM MOVING SOUTHEAST ACROSS THE EASTERN AREAS. THIS FEATURE WILL CONTINUE TO MOVE SOUTHEAST AND OUT OF THE AREA THIS MORNING. REST OF THE AREA SHOULD BE DRY OVERNIGHT EVEN THOUGH DEW POINTS REMAIN ELEVATED IN THE UPPER 60S TO LOWER 70S. EXPECTING DRY VFR CONDITIONS THROUGH THE DAY TODAY BUT ANOTHER SHOT OF PRECIPITATION IS POSSIBLE LATER TONIGHT AS ANOTHER VIGOROUS VORTICITY MAXIMUM MOVES SOUTHEAST ACROSS THE FORECAST AREA. THE EARLIEST THE CONVECTION COULD OCCUR WOULD BE AROUND 06Z IN THE WEST AND THE REST OF THE AREA THROUGH THE REST OF THE NIGHT. .OUTLOOK...VFR SHOULD PREVAIL THROUGH TUESDAY EXCEPT WITH A THREAT OF SHOWERS/THUNDERSTORMS SATURDAY NIGHT AND SUNDAY. && .MARINE... LAKE LOOKS RELATIVELY QUIET OVER THE NEXT SEVERAL DAYS AS WEAK GRADIENT SETS UP OVER THE LAKE AND WEAK STORM SYSTEMS MOVE ACROSS THE AREA. NOT EXPECTING THE NEED TO ISSUE ANY HEADLINES FOR THE LAKE OVER THE NEXT 5 DAYS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR OHZ003-006>008-017-018-027-028-036-037-047. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...LOMBARDY AVIATION...LOMBARDY MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
319 AM CDT FRI JUN 29 2012 .SHORT TERM...TODAY THROUGH SUNDAY NIGHT 319 AM CDT FRI JUN 29 2012 MAIN FORECAST CONCERN IS PRECIPITATION CHANCES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED SUBTROPICAL RIDGING COVERING MUCH OF THE SOUTHERN U.S. WITH A RIDGE AXIS EXTENDING FROM EASTERN WYOMING INTO EASTERN ALBERTA. THE FORECAST AREA LIES IN WEST-NORTHWEST FLOW DOWNSTREAM OF THE RIDGE AXIS. PLENTY OF DRY AIR SEEN ON WATER VAPOR INDICATING SUBSIDENCE IN PLACE...LEADING TO THE QUIET OVERNIGHT THUS FAR. 00Z MPX AND GRB SOUNDINGS SHOWED THE DRY...SUBSIDENT AIR QUITE NICELY WITH PRECIPITABLE WATER VALUES AROUND 0.77 INCHES OR 85 PERCENT OF NORMAL. JUST TO OUR SOUTH...A STREAM OF MOISTURE CAN BE SEEN IN WATER VAPOR OVER SOUTHERN IOWA. BIG DIFFERENCE WHEN IT COMES TO PRECIPITABLE WATER IN THIS MOISTURE STREAM COMPARED TO MPX...WITH THE 00Z OAX AND DVN SOUNDINGS SHOWING VALUE AROUND 2 INCHES OR NEARLY 200 PERCENT OF NORMAL. THIS HIGH AMOUNT OF MOISTURE IS REFLECTED TOO AT THE SURFACE WITH DEWPOINTS BETWEEN 75-80F ALONG A LINE BETWEEN HASTINGS NEBRASKA AND PEORIA ILLINOIS. THE MORE TROPICAL MOISTURE IS SITTING JUST NORTH OF A STATIONARY FRONTAL BOUNDARY. ALONG THE FRONTAL BOUNDARY...VARIOUS CLUSTERS OF STORMS HAVE BEEN TRACKING ACROSS NEBRASKA THROUGH THE OVERNIGHT HOURS. THESE HAVE BEING AIDED BY 925-850MB MOISTURE TRANSPORT OVER WESTERN KANSAS. ONE OF THE CLUSTERS CROSSING CENTRAL NEBRASKA HAS AN MCV WITH IT. ANOTHER ZONE OF 850MB MOISTURE TRANSPORT IS NOTED OVER IOWA...GOING OVER TOP OF THE FRONT...PER VWP DATA. SO FAR NO CONVECTION HAS FIRED ON THE NOSE OF THIS TRANSPORT...THOUGH SOME 4000-6000 FT CLOUD BASES ARE PRESENT. FINALLY...TO THE WEST...A WEAK SHORTWAVE WAS NOTED OVER EASTERN MONTANA GOING THROUGH THE RIDGE AXIS...WITH SOME LIGHTNING ACCOMPANYING IT. TODAY AND TONIGHT...FORECAST IS A LITTLE DIFFICULT RIGHT OFF THE BAT WITH MOST MODELS STRUGGLING TO CAPTURE THE CONVECTION IN NEBRASKA. FIRST...IN GENERAL WITH THE UPPER FLOW...MODELS PROG THE RIDGE AXIS OVER THE NORTHERN ROCKIES TO SHIFT EAST INTO THE WESTERN DAKOTAS BY 12Z SATURDAY. THERE ARE ALSO SIGNALS FROM ALL MODELS THAT SOME FORM OF WEAK TROUGHING WILL BE OVER THE FORECAST AREA AT 12Z SATURDAY. THIS TROUGHING APPEARS TO FORM FROM A RESULT OF THE EASTERN MONTANA SHORTWAVE AND THE MCV MOVING THROUGH/BY THE AREA. MAIN QUESTION IS WILL ANY PRECIPITATION OCCUR AS THESE SHORTWAVES PASS BY OR MOVE THROUGH. ONGOING NEBRASKA CONVECTION SHOULD DIMINISH THIS MORNING AS IT ENTERS NORTHWEST MO/SOUTHWEST IOWA WITH THE WEAKENING OF THE LOW LEVEL JET. FOCUS FOR THIS MORNING IS ALSO ON THE ZONE OF 850MB MOISTURE TRANSPORT OVER IOWA. POTENTIAL DOES EXIST FOR CONVECTION TO FIRE ON THE NOSE OF IT BETWEEN 09-12Z OVER NORTHERN IOWA. ALSO... THERE APPEARS TO BE AN UPPER JET STREAK CROSSING I-90 THIS MORNING...WHICH IS CURRENTLY IN SOUTHWEST MINNESOTA. THIS WOULD GIVE A BRIEF UPPER DIVERGENCE SURGE. SHOULD CONVECTION GO...CAPE VALUES LIFTED FROM 850MB ARE NEAR 3000 J/KG WITH NO CIN AND 1-6 KM SHEAR NEAR 40 KT...SUGGESTING POTENTIAL FOR ORGANIZED SEVERE STORMS. THIS MOISTURE TRANSPORT BENDS MORE WEST AND NORTHWEST THROUGH THE MORNING...SUGGESTING ANY CONVECTION WOULD PROBABLY BE OVER WITH BY 15Z. ATTENTION THEN TURNS TO THE EASTERN MONTANA SHORTWAVE...LIKELY COMING AT THE AREA DURING THE AFTERNOON AND EVENING. IF CONVECTION DOES NOT FIRE EARLY THIS MORNING...CONVECTION COULD FIRE UP ALONG/SOUTH OF I-90 LATE THIS AFTERNOON AND EVENING WITH THIS SHORTWAVE. 0-6KM SHEAR FOR THE AFTERNOON/EVENING IS AROUND 30 KT...SUGGESTING MAYBE SOME ORGANIZED MULTI-CELL CONVECTION...WHICH COULD POSE AT MOST A RISK FOR DAMAGING WINDS. OVERALL..CONFIDENCE NOT THAT HIGH FOR SEVERE THIS AFTERNOON/EVENING. IN FACT...OVERALL CONFIDENCE ON THIS PRECIPITATION FORECAST IS LOW...REFLECTED BY THE 20-40 PERCENT PROBABILITIES. SATURDAY THROUGH SUNDAY NIGHT...PRECIPITATION FORECAST REMAINS TRICKY. MODELS ARE IN GOOD AGREEMENT THAT THE RIDGE AXIS WILL REMAIN OVER THE DAKOTAS...WITH SOME SUGGESTION OF MORE AMPLIFICATION TOWARDS SUNDAY NIGHT AS A MORE POTENT SHORTWAVE CROSSES THE NORTHERN ROCKIES. THE UPPER FLOW STAYS WEST-NORTHWESTERLY OVER THE FORECAST AREA...MEANING THAT THE SURFACE FRONTAL BOUNDARY WILL LIKELY HOVER AROUND I-80 IN IOWA. MODELS ARE PRODUCING A VARIETY OF SHORTWAVES THAT RIDE ALONG THE BOUNDARY...SOME WHICH MIGHT BE REAL AND OTHERS CONVECTIVELY INDUCED. GIVEN THE PLENTIFUL INSTABILITY AROUND THE BOUNDARY...ANY SHORTWAVE COULD BRIEFLY SURGE THIS INSTABILITY NORTH INTO SOUTHERN PORTIONS OF THE FORECAST AREA AND INITIATE CONVECTION. HOWEVER...THE BULK OF ANY CONVECTION SHOULD STAY SOUTH OF THE FORECAST AREA CLOSER TO THE INSTABILITY. ENOUGH CONFIDENCE EXISTS TO REMOVE PRECIPITATION CHANCES ON SATURDAY WITH ALL MODELS FOCUSING ANY 850MB MOISTURE TRANSPORT AND SURFACE FRONTAL CONVECTION SOUTH OF THE AREA. 20 PERCENT CHANCES EXIST ACROSS MUCH OF THE FORECAST AREA SATURDAY NIGHT AND SUNDAY WITH SUGGESTIONS THAT THE 850MB MOISTURE TRANSPORT SURGES BACK NORTH. SUNDAY NIGHT STILL LOOKS OKAY TO HAVE A DRY FORECAST WITH LITTLE OR NO MOISTURE TRANSPORT...OR SHORTWAVE SUGGESTED TO KICK OFF CONVECTION. TEMPERATURES...THROUGHOUT THE SHORT TERM...925MB AND 850MB READINGS DO NOT CHANGE A WHOLE LOT DAY TO DAY...RUNNING BETWEEN 22-26C AND 18-22C RESPECTIVELY AT 18Z. COOLEST 925MB AND 850MB TEMPS ARE SUGGESTED OVER CENTRAL WISCONSIN. GIVEN POTENTIAL TO SEE QUITE A FEW HOURS OF SUN EACH DAY...HIGHS SHOULD STAY FAIRLY CONSISTENT. SAME GOES FOR LOWS TOO WITH LITTLE ADVECTION EXPECTED. DEWPOINTS DO NOT SEEM TO GET HIGH ENOUGH SOUTH OF I-90 TO WARRANT ANY HEAT ADVISORY HAZARD. RIGHT NOW...ANTICIPATING MAX HEAT INDICES BETWEEN 90-95. .LONG TERM...MONDAY THROUGH THURSDAY NIGHT 319 AM CDT FRI JUN 29 2012 GENERAL THEME FROM THE 29.00Z ECMWF...CANADIAN...UKMET...GFS AND GFS ENSEMBLES...AS WELL AS THEIR PREVIOUS RUNS...IS TO SUGGEST THE SUBTROPICAL RIDGE BUILDING AND EXPANDING NORTHWARD. HOWEVER...THERE IS ONE HUGE DIFFERENCE...WHERE THE ECMWF RUNS ALLOW THE RIDGING TO BUILD UP INTO THE FORECAST AREA WHEREAS ALL OTHER MODELS HAVE SOME FORM OF TROUGHING INDICATED OVER THE GREAT LAKES. THIS CREATES HAVOC FOR BOTH TEMPERATURE AND PRECIPITATION FORECASTING. SHOULD THE ECMWF RUNS BE CORRECT...MUCH IF NOT ALL OF THE LONG TERM IS DRY AND HOT WITH HIGHS LIKELY EACH DAY FROM THE MID 90S TO LOW 100S BEGINNING TUESDAY. ON THE OTHER HAND...OTHER MODELS CAN HAVE A SERIES OF SHORTWAVES AND FRONTS DROPPING THROUGH A NORTHWEST FLOW...ONE OF WHICH IS PROMINENTLY DISPLAYED FOR TUESDAY. FOR NOW...PRETTY MUCH STAYED WITH A CONSENSUS BLEND UNTIL MODELS CAN BECOME IN BETTER AGREEMENT. THIS RESULTS IN PRETTY MUCH EVERY 12 HOUR PERIOD HAVING AROUND A 20 PERCENT CHANCE OF PRECIPITATION WITH HIGHS IN THE MID 80S TO LOWER 90S. WE DEFINITELY HAVE TO WATCH THE LONG TERM PERIOD FOR A HEAT WAVE...SEEING TOO SOME SUPPORT FROM THE CFS TO GO ALONG WITH THE ECMWF. && .AVIATION... 1100 PM CDT THU JUN 28 2012 A WEST TO EAST RUNNING FRONTAL BOUNDARY WILL WAVER JUST SOUTH OF THE LOCAL AREA THROUGH THE WEEKEND WHILE HIGH PRESSURE BUILDS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE BOUNDARY WILL SERVE AS A FOCUS FOR PERIODS OF SHRA/TS...WITH ANY UPPER LEVEL SHORTWAVE AND/OR IMPINGEMENT OF THE LOW LEVEL JET/MOISTURE TRANSPORT ENHANCING THE PCPN CHANCES. MOSTLY THOUGH...MODELS FAVOR KEEPING THIS PCPN SOUTH OF KRST/KLSE...AND WILL CONTINUE TO KEEP THE TAFS DRY FOR NOW. SOME HIGH MID/UPPER LEVEL CLOUDINESS SHOULD MOVE IN FRI AFTERNOON FROM CONVECTION OVER IA. VFR CONDITIONS ARE EXPECTED. WINDS WILL BE SOMEWHAT VARIABLE AT TIMES...BECOMING SOUTH FRI MORNING...THEN VARIABLE TO WEST BY EARLY EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... 319 AM CDT FRI JUN 29 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS ALBANY NY
654 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WEAK FRONT WILL MOVE ACROSS THE REGION THIS MORNING...AS HIGH PRESSURE WILL BUILD IN FROM THE WESTERN GREAT LAKES REGION THIS AFTERNOON WITH HOT...BREEZY...AND DRY WEATHER. ABOVE NORMAL TEMPERATURES WILL PERSIST DURING THE WEEKEND. AN UPPER LEVEL DISTURBANCE...AND A WEAK COOL FRONT MAY FOCUS SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON INTO THE EVENING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 645 AM EDT...ANOTHER QUICK UPDATE TO ADJUST THE HOURLY POP AND WX GRIDS BASED ON THE RADAR TRENDS. THE CONVECTION HAS FALLEN A PART OVER THE FCST AREA. THERE IS JUST AN ISOLATED RUMBLE OF THUNDER HERE AND THERE. THE BACK EDGE OF THE SHOWERS IS APPROACHING THE HUDSON RIVER VALLEY. EXPECT THE SHOWER ACTIVITY TO BE EAST OF THE FCST AREA BY 13Z. THE SKIES SHOULD BEGIN TO CLEAR BY THE LATE MORNING WITH BREEZY AND HOT CONDITIONS FOR THE AFTERNOON...AS THE COOL FRONT HEADS EASTWARD ACROSS NEW ENGLAND. THE WATER VAPOR LOOP THIS MORNING SHOWS A BROAD MID LEVEL RIDGE CENTERED OVER THE TN VALLEY. AN IMPULSE IN THE W/NW FLOW MOVING ALONG THE PERIPHERY OF THE RIDGE HAS FOCUSED A MESOSCALE CONVECTIVE SYSTEM /MCS/ FORMING OVER W-CNTRL PA. THE MCS IS FIRING AHEAD OF A WEAK COLD FRONT AND HAS REACHED SRN NJ AND DE. A SHORT- WAVE TROUGH IS MOVING EAST OF LAKE ONTARIO THIS MORNING. THERE IS SOME INSTABILITY WITH MUCAPES OF AROUND 500 J/KG WITH POCKETS UP TO A 1000 J/KG. MOST OF THIS INSTABILITY IS ELEVATED WITH SHOWALTER VALUES OF 0 TO -2C. H700-500 LAPSE RATES ARE IN THE 6.5 TO 7C/KM RANGE. SFC DEWPTS ARE IN THE MID 50S TO L60S. THE LATEST HRRR HAS MOST OF THIS ACTIVITY MOVING EAST OF THE FCST AREA BY 12Z. WE HAVE TRENDED IT QUICKLY THROUGH THE AREA BY THE MID TO LATE MORNING. HIGH PRESSURE WILL BE BUILDING IN FROM THE W-CNTRL GREAT LAKES REGION. THE WATER VAPOR LOOP SHOWS A LOT OF MID AND UPPER LEVEL DRYING OVER THE ERN GREAT LAKES REGION...AND SE ONTARIO. THE STRONG SUBSIDENCE IN THE WAKE OF FRONT SHOULD ALLOW FOR MOSTLY SUNNY AND HOT CONDITIONS WITH H850 TEMPS IN THE 17C TO 20C RANGE. DEEP MIXING TO AROUND H850 WILL ALLOW BREEZY CONDITIONS WITH HIGHS IN THE U80S TO L90S IN THE VALLEYS /A FEW MID 90S IN THE MID HUDSON VALLEY/ AND U70S TO M80S OVER THE HILLS AND MTNS. IT WILL BE BREEZY WITH WEST WINDS OF 1O TO 20 MPH IN THE AFTERNOON WITH GUSTS IN THE 25 TO 35 MPH RANGE. THE SFC DEWPOINTS WILL BE MAINLY IN THE 50S. HEAT INDICES ARE NOT EXPECTED TO REACH THE ADVISORY RANGE WITH THE LOWERING SFC DEWPTS AND RH VALUES. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... FRIDAY NIGHT...A QUIET AND SEASONABLY COOL LATE JUNE EVENING IS EXPECTED WITH MOSTLY CLEAR/CLEAR SKIES...AND LIGHT TO CALM WINDS...AS A WEAK SFC ANTICYCLONE BUILDS IN FROM THE GREAT LAKES REGION AND THE OHIO VALLEY. RADITIONAL COOLING SHOULD ALLOW TEMPS TO FALL BACK INTO THE 50S TO L60S WITH A FEW U40S OVER THE SRN DACKS. THERE MAYBE SOME PATCHY FOG NEAR THE CT RIVER VALLEY. WE PLACED IT IN NEAR ERN WINDHAM CTY BETWEEN 09Z-12Z. SATURDAY...A NICE WARM DAY IS EXPECTED TO START...THEN ANOTHER WEAK COLD FRONT AND ITS ASSOCIATED MID LEVEL SHORT-WAVE MAY FOCUS ISOLD SHOWERS AND THUNDERSTORMS IN AFTERNOON FROM THE CAPITAL REGION NORTH AND WEST...AND SCT SHOWERS WITH ISOLD THUNDERSTORMS SOUTH AND EAST. LIMITED INSTABILITY OF 500-100 J/KG IS EXPECTED SOUTH OF THE CAPITAL REGION WITH MID LEVEL LAPSE RATES APPROACHING 7C/KM AGAIN. THE CONVERGENCE LOOKS WEAK WITH THE DISTURBANCE. THE BEST DEEP SHEAR OF 30-40 KTS IS OVER THE SOUTHERN ZONES. WE ARE NOT EXPECTING ANY SVR THUNDERSTORMS AT THIS TIME..BUT A FEW COULD BE STRONG IF GREATER AMOUNTS OF INSTABILITY ARE IN PLACE. MAX TEMPS COULD REACH IN THE U80S TO L90S ONCE AGAIN IN THE VALLEYS...WITH U70S TO M80S OVER THE HILLS/MTNS. SATURDAY NIGHT...THE MID LEVEL IMPULSE AND COLD FRONT MOVE EAST OF THE REGION WITH THE ISOLD-SCT SHOWER AND THUNDERSTORM ACTIVITY ENDING. MIN TEMPS WILL BE WARMER THAN THE PREVIOUS NIGHT WITH MID AND UPPER 50S NORTH OF THE MOHAWK VALLEY/CAPITAL REGION...AND LOWER TO MID 60S FROM THESE LOCATIONS SOUTH AND EAST. SUNDAY/SUNDAY NIGHT...THE SHORT RANGE GUIDANCE IS INDICATING THE LONGWAVE TROUGH AXIS WILL REMAIN UPSTREAM OF ERN NY AND WRN NEW ENGLAND TO START THE DAY. SOME ISOLD SHOWERS OR THUNDERSTORMS MAY FORM AHEAD OF THE UPPER LEVEL TROUGH AXIS. SOME SLIGHT CHC POPS WERE LEFT IN THE GRIDDED FORECAST. THE DEGREE OF INSTABILITY IS IN QUESTION FOR GREATER THUNDERSTORM CHANCES. TEMPS SHOULD STILL RUN A LITTLE ABOVE NORMAL TO CLOSE THE WEEKEND. && .LONG TERM /MONDAY THROUGH THURSDAY/... NO BIG CHANGES IN THE EXPECTED LONGWAVE PATTERN FOR THE PERIOD WITH A TROUGH OVER THE NORTHWEST AND NORTHEAST WITH RIDGING ACROSS THE REST OF THE CONUS. SHORT WAVES WILL MOVE THROUGH THE TROUGH. THE GFS BECOMES MORE AMPLIFIED WITH THE PATTERN NEXT WEEK. HOWEVER THE HYDROMETEOROLOGICAL PREDICTION CENTER CONTINUES TO FAVOR THE ECMWF ENSEMBLE MEAN FOR THE PERIOD WHICH INDICATES A DRIER FORECAST. SO HAVE KEPT THE FORECAST SIMPLE WITH LOW CLIMATOLOGICAL POPS THROUGH MUCH OF THE PERIOD. AS FOR TEMPERATURES...SEASONABLE TO SLIGHTLY ABOVE FOR OUR NEXT OF THE WOODS WITH THE HEAT CONTINUING ACROSS MUCH OF THE INTERIOR UNITED STATES. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... CONVECTION HAS BEEN WEAKENING AS IT MOVES ACROSS THE FORECAST AREA EARLY THIS MORNING. BY 12Z IT WILL HAVE CLEARED KGFL...KALB AND KPOU AND SHOULD CLEAR KPSF BY 13Z. WITH THE PASSAGE OF THE MID LEVEL SHORT WAVE CLOUD COVER WILL DECREASE AND WINDS WILL BECOME WESTERLY AND INCREASE TO 12 TO 18 KNOTS WITH GUSTS IN THE 20S. THE STRONGEST WINDS WILL BE AT KALB. THE WINDS WILL DIMINISH THIS EVENING WITH SOME MVFR FOG IS EXPECTED TO FORM LATE AT NIGHT. OUTLOOK... SAT...VFR. SLIGHT CHC AFTERNOON -SHRA/-TSRA WITH MVFR POSSIBLE. SAT NIGHT...VFR. NO SIG WX. SUN...VFR. SLIGHT CHC AFTERNOON -SHRA/-TSRA WITH MVFR POSSIBLE. SUN NIGHT...MAINLY VFR. SLIGHT CHC -SHRA. MON...VFR. CHC MAINLY AFTERNOON --SHRA/-TSRA. TUE...VFR. NO SIG WX. && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITIES 25 TO 30 PERCENT THIS AFTERNOON ACROSS THE MID HUDSON VALLEY REGION... WIND GUSTS OF 25-35 MPH POSSIBLE THIS AFTERNOON IN THE MOHAWK VALLEY REGION...CAPITAL REGION...NORTHERN CATSKILLS...AND BERKSHIRES... A WEAK FRONT WILL MOVE ACROSS THE REGION THIS MORNING...AS HIGH PRESSURE WILL BUILD IN FROM THE WESTERN GREAT LAKES REGION THIS AFTERNOON WITH HOT...BREEZY...AND DRY WEATHER. ABOVE NORMAL TEMPERATURES WILL PERSIST DURING THE WEEKEND. AN UPPER LEVEL DISTURBANCE...AND A WEAK COOL FRONT MAY FOCUS SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON INTO THE EVENING. THE RH WILL FALL INTO THE 25-35 PERCENT RANGE IN THE VALLEYS...AND THE 35-50 PERCENT RANGE ACROSS THE HIGHER ELEVATIONS FRIDAY AFTERNOON. THE RH WILL HAVE AN EXCELLENT RECOVERY TO 80-100 PERCENT SATURDAY MORNING. DEW FORMATION IS LIKELY. THE RH VALUES WILL LOWER TO 25 TO 45 PERCENT ONCE AGAIN SATURDAY AFTERNOON. THE WINDS WILL VEER FROM THE SOUTH OR SOUTHWEST THIS MORNING...TO THE WEST BY THE AFTERNOON AT 10 TO 20 MPH...WITH SOME GUSTS IN THE 25 TO 35 MPH RANGE. THE WINDS WILL BECOME LIGHT AND VARIABLE AT 5 MPH OR LESS FRIDAY NIGHT. EXPECT WEST/SOUTHWEST WINDS OF 10 TO 20 MPH ON SATURDAY. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THE NEXT 5 DAYS. A WEAK FRONT WILL MOVE ACROSS THE HYDRO SERVICE AREA THIS MORNING WITH ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS. RAINFALL AMOUNTS WILL GENERALLY BE LIGHT WITH A FEW HUNDREDTHS TO A FEW TENTHS OF AN INCH. HIGH PRESSURE BRIEFLY BUILD THIS AFTERNOON THROUGH SATURDAY MORNING. ANOTHER WEAK COOL FRONT...AND AN UPPER LEVEL DISTURBANCE WILL BRING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS LATE SATURDAY AFTERNOON AND SATURDAY NIGHT. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE. CYCLONIC FLOW ALOFT MAY ALLOW ISOLATED SHOWERS...AND PERHAPS THUNDERSTORMS SUNDAY INTO EARLY NEXT WEEK. AGAIN...NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...WASULA NEAR TERM...WASULA SHORT TERM...WASULA LONG TERM...IAA AVIATION...IAA FIRE WEATHER...KL/WASULA HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1034 AM CDT FRI JUN 29 2012 .DISCUSSION... ISSUED 1034 AM CDT FRI JUN 29 2012 ANOTHER EXTREMELY HOT DAY IS UNFOLDING ACROSS CENTRAL AND SOUTHEAST ILLINOIS...WITH 15Z TEMPS ALREADY WELL INTO THE 90S ACROSS THE SE KILX CWA. READINGS ARE SLIGHTLY COOLER ACROSS THE FAR NORTH...WHERE A FEW CLOUDS AND HIGHER DEWPOINTS ARE KEEPING TEMPS DOWN JUST A BIT. FRONTAL BOUNDARY THAT SAGGED SOUTHWARD TO NEAR THE I-74 CORRIDOR LAST NIGHT IS LIFTING BACK NORTHWARD...KEEPING THE BEST CHANCES FOR CONVECTION CONFINED TO NORTHERN ILLINOIS. LATEST SATELLITE/RADAR IMAGERY CONTINUES TO SHOW DEVELOPING STORM COMPLEX TRACKING EASTWARD ALONG THE I-80 CORRIDOR. SOME OF THE HIGHER-RES MODELS SUCH AS THE 11Z HRRR SUGGEST THIS COMPLEX WILL EVENTUALLY BECOME SURFACE-BASED AND TAKE A TURN E/SE ALONG THE BOUNDARY. BASED ON LATEST TRENDS...IT APPEARS THAT BY THE TIME THIS HAPPENS THE STORMS WILL LIKELY MISS THE KILX CWA TO THE N/NE...EVENTUALLY SPILLING SOUTHEASTWARD INTO NORTH-CENTRAL INDIANA THIS AFTERNOON. ONLY CHANCE FOR CONVECTION ACROSS CENTRAL ILLINOIS WOULD BE POSSIBLE ISOLATED STORMS ALONG RESIDUAL OUTFLOW BOUNDARY LATER TODAY. HAVE THEREFORE TRIMMED POPS CONSIDERABLY...FEATURING ONLY A SLIGHT CHANCE ALONG/NORTH OF I-74. TEMP FORECAST LOOKS PRETTY MUCH ON TRACK...WITH HIGHS RANGING FROM THE MID 90S FAR NORTH AROUND LACON TO OVER 105 DEGREES ALONG/SOUTH OF I-70. BARNES && .AVIATION... ISSUED 640 AM CDT FRI JUN 29 2012 GENERALLY QUIET/VFR AVIATION WEATHER CONDITIONS EXPECTED ACROSS THE CENTRAL ILLINOIS TERMINALS THROUGH THE 00Z TAF VALID TIME. HOWEVER...A STALLED FRONTAL BOUNDARY OVER NORTHERN ILLINOIS POSES A RISK OF A SHOWER OR STORM ACROSS KPIA/KBMI/KCMI. HOWEVER... COVERAGE/CONFIDENCE IS TOO LOW TO GO ABOVE A VICINITY MENTION AT THIS TIME. BAK && .PREV DISCUSSION... ISSUED 317 AM CDT FRI JUN 29 2012 AT 06Z SFC FRONT HAD STALLED ALONG THE IA/MO BORDER EAST TO NEAR KPIA AND INTO NORTHERN IND. MID/UPPER 70S DEWPOINTS POOLED ALONG THE BOUNDARY. ALOFT...A LARGE MID LEVEL RIDGE OCCUPIED MUCH OF THE SOUTHERN HALF OF THE COUNTRY WHILE A FAST ZONAL FLOW WAS FARTHER NORTH. WATER VAPOR IMAGERY INDICATED SUBTROPICAL MOISTURE PLUME FROM THE DESERT SW UP INTO THE CENTRAL PLAINS AND ACROSS THE LOCAL AREA...ON THE PERIPHERY OF THE RIDGE. FORECAST CONCERNS REMAIN HIGH HEAT THROUGH THE PERIOD AND CONVECTION CHANCES IN RING OF FIRE PATTERN ON NORTHERN FRINGE OF THE RIDGE. SHORT TERM...TODAY THROUGH SUNDAY LOW CONFIDENCE FORECAST IN CONVECTIVE TRENDS NEXT FEW DAYS AS MESOSCALE FEATURES DRIVE THUNDERSTORM ACTIVITY. NORTHERN CWA WILL BE IN CLOSER PROXIMITY TO FAVORABLE SYNOPTIC FEATURES...SFC BOUNDARY AND STRONGER MID LEVEL FLOW/SHORTWAVE ENERGY TRACK. HIGH INSTABILITY...MODERATE SHEAR...AND HIGH PRECIPITABLE WATER WILL LEAD TO POTENTIAL FOR SEVERE MCS/S AND LOCALLY HEAVY RAIN WHICH MAY IMPACT OR STAY JUST NORTH OF THE CWA. FOR THESE REASONS WILL KEEP LOW CHC POPS GOING PRIMARILY NORTH OF A CANTON TO BLOOMINGTON THROUGH SATURDAY NIGHT...TAPERING TO SLIGHT CHC CENTRAL. A STRONGLY CAPPED AIRMASS SHOULD SUPPRESS ANY DEVELOPMENT ACROSS THE SOUTH HALF. HIGHER CONFIDENCE IN TEMPERATURES WHICH WILL STAY VERY HOT THROUGH THIS WEEKEND. IN FACT TODAYS READINGS MAY NOT BE FAR OFF YESTERDAYS NUMBERS WHICH WERE 100+ FOR MUCH OF THE AREA. TEMPS COOL ONLY A FEW DEGREES THIS WEEKEND WITH HIGHS STILL IN THE MID OR UPPER 90S NORTH AND LOW 100S SOUTH. APPARENT TEMPS ONLY DROPPING INTO THE UPPER 70S TONIGHT WILL REQUIRE EXTENDING HEAT ADVISORY TO 12Z SATURDAY. AREAS SOUTH OF I-70 LOOK TO BE BORDERLINE FOR ADVISORY CRITERIA AGAIN ON SATURDAY AFTERNOON AND ADVISORY MAY NEED TO BE EXTENDED HERE IN LATER FORECASTS. LONG TERM...MONDAY THROUGH THURSDAY UNFORTUNATELY NO PROSPECTS FOR A MAJOR PATTERN CHANGE IN THE EXTENDED TO BRING COOLER AIR INTO THE MIDWEST. LATEST GUIDANCE SUGGESTS MID LEVEL RIDGING SHIFTING EVEN FARTHER NORTH THROUGH THE WEEK. THIS WOULD DRIVE MCS TRACK FARTHER NORTH LEAVING A DRY AND HOT FORECAST FOR THE ENTIRE CWA THROUGH THURSDAY. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR ILZ027>031-036>038- 040>057-061>063-066>068-071>073. && $$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
648 AM EDT FRI JUN 29 2012 .SYNOPSIS... ISSUED AT 342 AM EDT FRI JUN 29 2012 HIGHS AROUND 90 OR HIGHER ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK. CHANCES FOR RAIN ARE LOW SO THE VERY DRY WEATHER WILL CONTINUE. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 342 AM EDT FRI JUN 29 2012 FORECAST CONCERNS DEAL MAINLY WITH LOW CHANCES OF PCPN FOR THE NEXT FEW DAYS. DIDN/T CHANGE THE FCST MUCH. THE WEAK COLD FRONT THAT PASSED THROUGH THE REGION YESTERDAY STRETCHES FROM NORTHERN OHIO WWD THROUGH NRN ILLINOIS. THIS BOUNDARY WILL LIKELY ACT AS A FOCUS FOR CONVECTION DEVELOPING OVER THE CENTRAL PLAINS EARLY THIS MORNING AS IT MOVES EWD. HRRR AND ECMWF SUGGEST THAT SOME OF THE PLAINS CONVECTION WILL MOVE ACROSS IOWA AND NRN ILLINOIS AROUND 12Z BEFORE MOVING JUST SOUTH OF THE CWA MID MORNING. WE ADDED A SLIGHT CHANCE FOR A FEW HOURS OVER THE FAR SW CWA TO ACCOUNT FOR THIS. THE FRONTAL BOUNDARY TO THE SOUTH IS PROGD TO REMAIN SOUTH OF THE CWA THROUGH EARLY SUNDAY BEFORE BEGINNING TO MOVE NORTHEASTWARD. THUS CHANCES FOR PCPN ARE SLIM UNTIL SUNDAY WHEN CHANCES IMPROVE A BIT. AN UPPER TROUGH WILL TRY TO MOVE SOUTH OVER NRN LWR SUNDAY AT THE SAME TIME THAT THE SFC BOUNDARY IS LIFTING NORTH. H8 TEMPS WILL BE SEVERAL DEGREES COOLER TODAY THAN FRIDAY. THUS WE/LL LIKELY SEE HIGHS AROUND 90 VS MID TO UPPER 90S ON FRIDAY. AS A RESULT WE WON/T HIT HEAT ADVISORY CRITERIA. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 AM EDT FRI JUN 29 2012 FOR THE MOST PART IT WILL BE HOT AND DRY. THERE IS A SYSTEM THAT MAY BRING SOME SHOWERS TO THE AREA TUESDAY INTO WEDNESDAY. THE PRIMARY ISSUE IS HOW HOT DOES IT GET? IS THE ECMWF MORE CORRECT THAN THE GFS IN TERMS OF THE UPPER AIR PATTERN? IF THE ECMWF IS CORRECT HIGHS WILL BE IN THE MID TO UPPER 90S MOST OF THIS COMING WEEK...WHILE IF THE GFS IS CORRECT IT WILL MORE LIKELY BE MID TO UPPER 80S. GIVEN THE RECENT POOR PERFORMANCE OF THE GFS FOR TEMPERATURES... THE 28TH 06Z MAV HAD 90F FOR GRR ON THURSDAY.... I WOULD HAVE TO SIDE WITH THE ECMWF MORE SO. AS FOR THE UPPER AIR PATTERN... BOTH MODELS SHOW THE OVERALL PATTERN NICELY AND SUGGEST LITTLE OVERALL CHANGE. THAT IS A LARGE NEARLY STATIONARY UPPER LEVEL HIGH CENTERED OVER THE CENTRAL CONUS AND TROUGHS ON BOTH THE WEST AND EAST COAST. THE PROBLEM COMES IN AS TO WERE THE POLAR JET WILL ACTUALLY BE? THE ECMWF HAS A MUCH FLATTER EASTERN TROUGH (KEEPS THE COOLER AIR WELL NORTH AND EAST OF SOUTHWEST MICHIGAN ALL WEEK) WHILE THE GFS HAS THIS FEATURE MUCH NEARER SOUTHWEST MICHIGAN. I AM FAVORING THE ECMWF AND IN SO DOING PUSHED OUR TEMPERATURE GRIDS IN THAT DIRECTION BUT ONLY BY A FEW DEGREES. AS FOR OUR SHOWERS IN THE TUESDAY/WEDNESDAY TIME FRAME THIS IS A SHORTWAVE TOPPING THE UPPER RIDGE. I WOULD LOOK FOR LIMITED CONVECTION AT BEST WITH THIS FEATURE AND MORE THAN LIKELY IT WOULD SPLIT AND MOST OF THE STORMS WILL GO SOUTH OF LOWER MICHIGAN OR OVER NORTHERN LOWER OR UPPER MICHIGAN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 647 AM EDT FRI JUN 29 2012 ONCE THE PATCHY FOG LIFTS OUT OF THE JXN TAF SITE (BY 13Z) I EXPECT VFR CIGS/VSBY THROUGH SATURDAY. AN AREA OF THUNDERSTORMS MAY PASS SOUTH OF I-94 TONIGHT BUT ALL THAT WILL DO THE TAFS IN SOUTHWEST MICHIGAN IS BRING LAYERED MID AND HIGH CLOUDS. && .MARINE... ISSUED AT 342 AM EDT FRI JUN 29 2012 RELATIVELY LIGHT WINDS WILL RESULT IN LOW WAVES TODAY. && .HYDROLOGY... ISSUED AT 342 AM EDT FRI JUN 29 2012 DRY WEATHER EXPECTED TODAY AND SATURDAY. A BETTER CHANCE OF STORMS EXISTS SUNDAY...BUT BASIN QPF WILL REMAIN QUITE LOW AND THE DRY CONDITIONS WILL PREVAIL. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...93 SHORT TERM...93 LONG TERM...WDM AVIATION...WDM HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
550 AM CDT FRI JUN 29 2012 .SHORT TERM... ISSUED AT 250 AM CDT FRI JUN 29 2012 (TODAY AND TONIGHT) THE UNPRECEDENTED JUNE HEAT WAVE WILL CONTINUE. HAVE NOT DEVIATED MUCH FROM GOING HIGHS FOR TODAY WHICH ARE CLOSER TO THE WARMER NAM MOS TEMPERATURES WHICH HAVE BEEN VERIFYING BETTER RECENTLY THAN THE COOLER GFS VALUES. THE RAP IS SHOWING MIXING TO AROUND 800MB THIS AFTERNOON WITH SURFACE TEMPERATURES CLIMBING ABOVE +40C LIKE THEY DID ON THURSDAY AFTERNOON. DEWPOINTS HAVE RECOVERED SOME EARLY THIS MORNING...BUT DEEP MIXING THIS AFTERNOON SHOULD CAUSE THEM TO FALL OFF AGAIN TODAY. HAVE A SLIGHT CHANCE FOR THUNDERSTORMS LATE TONIGHT OVER A SMALL PART OF THE NORTHERN CWA. THERE WILL BE A WEAK SHORTWAVE MOVING ACROSS IOWA ALONG AN EXISTING FRONT THAT COULD CAUSE A FEW THUNDERSTORMS TO MOVE DOWN INTO NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS. THE DRY ATMOSPHERE WOULD SUPPORT FORWARD PROPAGATION WHICH WOULD TEND TO KEEP ANY COMPLEX OF THUNDERSTORMS MOVING EASTWARD WITH TIME. OTHERWISE...NAM MOS LOWS LOOK GOOD FOR TONIGHT. BRITT && .LONG TERM... ISSUED AT 250 AM CDT FRI JUN 29 2012 (SATURDAY THROUGH THURSDAY) HEAT ADVISORY WILL NOW BE EXTENDED THROUGH SUNDAY AS THERE WILL BE YET ANOTHER DAY WITH HEAT INDEX READINGS BETWEEN 100-105. WILL KEEP THE SLIGHT CHANCE FOR THUNDERSTORMS OVER NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS SATURDAY AND SATURDAY NIGHT AS A FRONT LINGERS OVER SOUTHERN IOWA INTO CENTRAL ILLINOIS. HOWEVER...THIS FRONT WILL MOVE BACK NORTH AS A WARM FRONT ON SUNDAY. MORE CLOUDS IN ADDITION TO THE SLIGHT CHANCE OF RAIN WILL LIKELY CAUSE THE AMBIENT TEMPERATURES TO BE SLIGHTLY LESS OVER NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS THAN WHAT THEY WHERE ON THURSDAY. HOWEVER...THERE WILL ALSO BE SLIGHTLY HIGHER DEWPOINTS BECAUSE OF MOISTURE POOLING WHICH WILL ONLY RAISE THE HEAT INDEX. FARTHER SOUTH...DEEP MIXING IN ADDITION...PLENTY OF SOLAR INSOLATION AND 850MB TEMPS IN THE 23-26 RANGE SUPPORT WIDESPREAD 100+ TEMPERATURES LIKE THE NAM MOS. NAM 2M TEMPS ARE IN THE 100-105F RANGE OVER MOST OF THE CWA TODAY THROUGH SUNDAY. MOST OF THE GUIDANCE ALSO INDICATES THERE SHOULD BE A SLOW CLIMB IN DEWPOINTS THROUGH THE WEEKEND. NEW GFS/ECMWF STILL LOOKS HOT AND DRY MOST OF NEXT WEEK AS UPPER HIGH OVER THE SOUTHERN ROCKIES BUILDS NORTHEAST INTO THE CENTRAL CONUS. 850MB TEMPS WILL REMAIN IN THE LOWER-MID 20S CELSIUS. BRITT && .AVIATION... ISSUED AT 518 AM CDT FRI JUN 29 2012 WEAK FRONT EXTENDS ACROSS SRN IA AND CNTRL IL...N OF UIN EARLY THIS MRNG. IT APPEARS THAT CONVECTION ASSOCIATED WITH THIS FRONT WILL REMAIN N OF UIN...BUT THERE MAY BE SOME MID-HIGH LEVEL CLOUDS SKIRTING UIN. FURTHER S AT THE OTHER TAF SITES IT SHOULD REMAIN CLEAR. SFC WINDS SHOULD BE W-SWLY WITH THE SFC RIDGE S OF OUR AREA. THE SFC WIND SPEED WILL INCREASE TO ABOUT 10-12 KTS THIS AFTN...THEN WEAKEN AGAIN THIS EVNG. SPECIFICS FOR KSTL...CLOUDS SHOULD REMAIN N OF STL AREA THIS FORECAST PERIOD. LIGHT NWLY SFC WIND SHOULD BECOME W-SWLY LATER THIS MRNG AND AFTN INCREASING TO AROUND 10-11 KTS...THEN WEAKENING AGAIN THIS EVNG. GKS && .FIRE WEATHER... ISSUED AT 250 AM CDT THU JUN 28 2012 NO CHANGE TO THINKING ABOUT A HEIGHTENED FIRE DANGER TODAY AS ONLY THE WIND STAYING BELOW 15 MPH WILL KEEP THE AREA FROM NEEDING A RED FLAG WARNING. MINIMUM RELATIVE HUMIDITY VALUES WILL BE AT OR BELOW 20 PERCENT OVER MUCH OF THE AREA AND FORECAST 10 HOUR DEAD FUELS WILL BE 5-6 PERCENT. EXPECT SIMILAR CONDITIONS OVER THE WEEKEND. WILL CONTINUE TO HIGHLIGHT IN THE FIRE WEATHER FORECAST... SPECIAL WEATHER STATEMENTS...AND HAZARDOUS WEATHER OUTLOOK. && .CLIMATE... ISSUED AT 330 AM CDT THU JUN 28 2012 RECORD HIGHS DATE ST. LOUIS COLUMBIA QUINCY ---------------------------------------------- JUNE 29 105(1952) 104(1901) 103(1934) JUNE 30 103(1931) 103(1901) 103(1931) JULY 01 105(1980) 110(1980) 104(1930) JULY 02 101(1933) 102(1901) 103(1934) JULY 03 101(1934) 104(1901) 104(1911) JULY 04 102(1990) 106(1901) 103(1936) JULY 05 102(1938) 105(1911) 104(1911) && .LSX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO- CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO- IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO- MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. IL...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR ADAMS IL-BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL- MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL- PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
617 AM EDT FRI JUN 29 2012 .SYNOPSIS... WEAK HIGH PRESSURE AND A BUILDING UPPER RIDGE WILL SPREAD WARM AIR INTO THE REGION...RESULTING IN ABOVE NORMAL TEMPERATURES AND MAINLY DRY WEATHER THROUGH THE WEEKEND. HOWEVER...WEAK DISTURBANCES PASSING THROUGH THE RIDGE ON SATURDAY AND SUNDAY...COULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... 6AM UPDATE... MINOR CHANGES TO THE TIMING OF THE CLOUDS AND PRECIP OUT OF THE AREA. ONLY IN DELAWARE COUNTY NY AND SHOULD BE OUT OF THE CWA BY 730 AM. CLOUDS WILL QUICKLY FOLLOW TO EXIT STAGE RIGHT. 4 AM UPDATE... SHOWERS AND THUNDERSTORMS MOVING ACROSS THE CWA ATTM. THESE BROUGHT ON BY UNSTABLE MID LAYERS AND SEVERAL SHORT WAVES. ALSO A SFC BOUNDARY. THIS WILL DIE SLOWLY AS IT MOVES ESE THROUGH THE AREA AND INTO NJ AND ERN NY BY 8 AM. AFTER THAT DRY AIR COMES IN AND NPV. WITH A LARGE LOW LEVEL CAP FEW IF ANY CLOUDS WILL FORM THIS AFTERNOON. WNW WINDS WILL PICK UP AND HELP WITH DRYING. DEWPOINT TEMPS FALL BACK INTO THE 50S. TONIGHT WITH BOUNDARY LEVEL WINDS UP AND MOST OF THE TWIN TIERS MISSING THE SHOWERS EARLY THIS MORNING...FOG WILL NOT BE WIDESPREAD LATE TONIGHT. FOR TEMPERATURES WENT CLOSE TO MOS WHICH HAS BEEN LESS THAN 2 DEGREES OFF LATELY. A FEW DEGREES WARMER TODAY OVER YESTERDAY FOR THE MAXES. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... 4 AM UPDATE... FAIRLY QUIET WITH WEAK DISTURBANCES MOVING THROUGH ON SATURDAY AND AGAIN LATE SUNDAY AND SUNDAY NIGHT. MODELS START TO DIVERGE ON SUNDAY ON STRENGTH AND LOCATION OF SYSTEMS AND PRECIP. FOR THE PERIOD REMAIN IN NW FLOW...WITH AN UPPER LEVEL TROF OVER THE NE US AND A LARGE RIDGE OVER THE PLAINS. A SHORT WAVE MOVES THROUGH SAT PM DIGGING THE NE US TROF A LITTLE DEEPER AND DROPPING TEMPERATURES SOME SO AFTER ANOTHER MID 80S TO A90 DEGREE DAY SATURDAY HIGHS SUNDAY WILL ONLY BE IN THE LOW AND MID 80S. THIS IS STILL ABOVE NORMAL. WITH DEWPOINTS FROM THE MID 50S TO THE LOW 60S NIGHTTIME TEMPERATURES WILL NOT FALL FAR. AGAIN WENT CLOSE TO MOS. SATURDAYS SHORT WAVE DROPS THROUGH PA SO BETTER CHANCES OF SHOWERS AND THUNDERSTORMS THERE. LATE SUNDAY AND SUNDAY NIGHT WENT WITH MORE OF A SLIGHT CHANCE OF SHOWERS AND TS EVERYWHERE GIVEN THE WIDE DIFFERENCES IN THE MODELS. BOTH DAYS NOT AS MUCH MODEL CONSENSUS AS EARLY THIS MORNING. ALSO THESE DISTURBANCES ARE WEAKER THAN NOW. LATE SATURDAY SPC HAS THE FAR SOUTH IN A SLIGHT CHANCE OF SEVERE THUNDERSTORMS. MODEL SOUNDINGS SHOW MUCH LESS OF A CAP THAN TODAY. ALSO WIND FIELDS INCREASE WITH DECENT SHEAR. SO EVEN WITH A WEAK DISTURBANCE THE INSTABILITY AND SHEAR WILL BE THERE TO WORK WITH. IN CENTRAL NY LESS MOISTURE AND MID LEVEL COOLING SO STABILITY WILL BE GREATER. && .LONG TERM /MONDAY THROUGH THURSDAY/... VERY FEW CHANGES MADE TO THE EXTENDED TIME FRAME AS MODEL AGREEMENT REMAINS LESS THAN FAVORABLE THROUGH THE PERIOD. IN GENERAL...THE UPPER-LEVEL PATTERN WILL BE DOMINATED BY CYCLONIC NORTHWEST FLOW ALOFT AS LONGWAVE BLOCKING ACROSS NORTH ATLANTIC PREVENTS EASTWARD PROGRESS OF AN EASTERN CANADIAN TROUGH. WITH THIS BEING THE CASE...AN ACTIVE BELT OF WESTERLIES WILL PREVAIL OVER OUR REGION WITH SEVERAL INDIVIDUAL SHORTWAVE DISTURBANCES EXPECTED TO TRANSLATE SOUTHEAST OVER OUR REGION. THE FIRST OF THESE SHORTWAVE FEATURES IS EXPECTED TO ARRIVE ON MONDAY...WHERE WE HAVE MAINTAINED A SLGT CHC MENTION FOR SHWRS/STORMS. FOLLOWING ITS DEPARTURE LATE MONDAY NIGHT...BRIEF SURFACE HIGH PRESSURE IS FORECAST TO SET IN WHICH SHOULD RESULT IN MAINLY DRY CONDITIONS ON TUESDAY. BY WEDNESDAY...THE ECMWF SHOWS A COLD FRONT/SFC LOW MOVING ACROSS THE REGION. UNFORTUNATELY THIS SOLUTION HAS VERY LITTLE SUPPORT FROM THE GFS WHICH MAINTAINS SFC HIGH PRESSURE ACROSS THE AREA. THAT SAID...BASED ON THE UNCERTAINTIES THIS FAR OUT...FELT BEST TO MAKE VERY FEW CHANGES AT THIS JUNCTURE. EXPECT NEAR TO SLIGHTLY ABOVE AVERAGE TEMPS THROUGH THE PERIOD AS WARM AIR ASSOCIATED WITH THE RECORD HEAT WAVE ACROSS THE NATION/S MIDSECTION REMAINS ACROSS THE LOWER OHIO VALLEY AND POINTS WEST. && .AVIATION /10Z FRIDAY THROUGH TUESDAY/... LATEST RADAR TRENDS SHOWING A LINE OF SHWRS/STORMS NOW MOVING ACROSS EASTERN LAKE ONTARIO. SOUTHEASTWARD MOVEMENT WILL PLACE THIS ACTIVITY OVER BOTH THE SYR AND RME TERMINALS SHORTLY. DRY LOW-LEVEL CONDITIONS SHOULD RESULT IN ONLY LGT SHWR ACTIVITY AND THUS WILL ONLY MENTION A TEMPO MVFR MENTION THROUGH 07Z AT BOTH SITES. ELSEWHERE...ISOLATED SHWRS NOW DEVELOPING OVER THE WESTERN SOUTHERN TIER OF NYS AS A SHORTWAVE CONTINUES TO DROP SOUTHEAST THROUGH THE AREA. BIGGEST QUESTION WILL BE WHETHER ACTIVITY WILL DEVELOPS AND MOVES OVER ELM. IF THIS WERE TO OCCUR...WE CANNOT RULE OUT TEMPORARY IFR CONDITIONS AFTER 08Z IN DEVELOPING FOG WITH MOISTENING LOW-LEVEL CONDITIONS. BASED ON ISOLATED NATURE OF THE ACTIVITY...ALONG WITH NEWLY ARRIVING HRRR SIMULATED REFLECTIVITY DATA...WE CURRENTLY DO NOT HAVE ENOUGH CONFIDENCE TO MENTION IFR AT THIS TIME. WILL CONTINUE TO MONITOR TRENDS HOWEVER. BEYOND THIS...EXPECT MOSTLY CLEAR SKIES THROUGH THE DAY WITH WEST WINDS BETWEEN 10-15 KTS POSSIBLY GUSTING TO NEAR 20 KTS DURING PEAK HEATING HRS. OUTLOOK... SAT...MAINLY VFR...AFTERNOON MVFR POSSIBLE AT ELM/ITH/BGM/AVP IN DEVELOPING SHWRS/STORMS. SUN...MAINLY VFR. MON/TUE...MAINLY VFR...HOWEVER ISOLATED MVFR CONDITIONS IN DEVELOPING -SHRA/TSRA ACTIVITY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...TAC NEAR TERM...TAC SHORT TERM...TAC LONG TERM...CMG/SLI AVIATION...CMG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
945 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WEAK COLD FRONT WILL SINK SLOWLY SOUTH TOWARD THE OHIO RIVER VALLEY TODAY. A WEAK AREA OF LOW PRESSURE WILL MOVE ACROSS THE REGION ON SATURDAY AND A LOW WILL MOVE ACROSS THE GREAT LAKES ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HAVE EXPANDED THE HEAT ADVISORY TO INCLUDE ALL BUT THE FAR NE END OF THE AREA. TEMPS AND DEWPOINTS ARE CONSIDERABLY WARMER THAN THEY WERE YESTERDAY AT THIS TIME. SO...EVEN THOUGH TEMPS ALOFT ARE A LITTLE COOLER THINK MUCH OF THE AREA WILL AGAIN REACH THE MID 90S. HAVE ALSO BUMPED PRECIP CHANCES UP SLIGHTLY AT THE SW END OF THE AREA TO ACCOUNT FOR THE MCS MOVING ACROSS IA. PREVIOUS...ON THE 6 AM UPDATE JUST TWEAKED THE CLOUDS FOR THIS AM AND CONTINUED WITH PATCHY DENSE FOG OVER INLAND NORTHWEST PA BECAUSE OF ALL THE RAIN. OTHERWISE STILL ON THE EDGE ABOUT HOW MUCH CONVECTION WILL OCCUR TODAY. ISSUED A HEAT ADVISORY FOR THE WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA. EVEN THOUGH A COLD FRONT HAS MOVES THROUGH...TEMPERATURES WILL RECOVER ESPECIALLY AWAY FROM INFLUENCES OF LAKE ERIE. LOCATIONS IN THE HEAT ADVISORY WILL COME CLOSE TO HEAT INDEX VALUES OF 100. AFTER A VERY WARM NIGHT...TEMPERATURES WILL HEAT UP QUICKLY. WENT WARMER THAN GUIDANCE...USED A MIX OF PRODUCTS. THE POP FORECAST IS TOUGH. THE HRRR MODEL IS TRYING TO INDICATE SOME SHOWERS MOVING THROUGH THE SOUTHERN PORTION OF THE FORECAST ARE TODAY. ON THE EDGE ABOUT THAT. WENT WITH SLIGHT CHANCE POPS WITH THE BOUNDARY SO CLOSE TO THAT AREA. FIRE WEATHER THREAT IS MUCH LOWER TODAY WITH HIGHER HUMIDITIES AND LIGHTER WINDS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE FORECAST IS VERY TOUGH TRYING TO TIME PRECIPITATION. WENT CLOSE TO PREVIOUS FORECAST...A THREAT TONIGHT AS AN MCS MAY COME OUT OF THE MIDWEST AND THEN THE THREAT CONTINUES SATURDAY INTO SUNDAY. A WAVE MOVES ALONG THE FRONT SATURDAY AND THEN A LOW MOVES ACROSS THE GREAT LAKES SUNDAY. WENT ON THE WARMER SIDE OF GUIDANCE. AT THIS TIME NOT EXPECTING TO MEET HEAT ADVISORY CRITERIA DURING THIS PERIOD. && .LONG TERM /TUESDAY THROUGH THURSDAY/... EXTENDED PERIODS COULD BE INTERESTING AS MODELS CONTINUE TO PLACE A STATIONARY FRONT NORTHWEST TO SOUTHEAST ACROSS THE AREA TUESDAY THROUGH THURSDAY MORNING. THIS IS A BIT CONCERNING DUE TO THE SERIES OF UPPER LEVEL POSITIVE VORTICITY MAXIMUMS ROTATING SOUTHEAST ON THE EAST SIDE OF THE UPPER LEVEL RIDGE. THIS COULD POSSIBLY TRANSLATE INTO A PERIOD OF ONE MESO CONVECTIVE SYSTEM AFTER ANOTHER AFFECTING THE FORECAST AREA. WILL HAVE TO MONITOR THE SITUATION TO SEE HOW THINGS DEVELOP. THERE HAS BEEN SOME CONSISTENCY IN THE OVERALL PATTERN OVER THE LAST FEW MODEL RUNS. THE OTHER ISSUE TO DEAL WITH IS THE SUMMER HEAT CONTINUES. INITIALLY...THE STATIONARY FRONT SETS UP ON MONDAY AND REMAINS THERE THROUGH THURSDAY. THIS FRONTAL BOUNDARY COULD MEAN A SPLIT BETWEEN RELIEF FROM THE HOT TEMPERATURES EAST TO CONTINUED HOT TEMPERATURES WEST. WILL MAKE ONLY SOME MINOR ADJUSTMENTS IN TEMPERATURES THROUGH THE EXTENDED PERIODS. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... AREA SHOULD BE DRY THROUGH THE DAY. SOME HAZE BEING REPORTED AT AKRON CANTON BUT HAS MINIMAL RESTRICTION TO VISIBILITY. ANOTHER SHOT OF PRECIPITATION IS POSSIBLE LATER TONIGHT AS ANOTHER VORTICITY MAXIMUM MOVES SOUTHEAST ACROSS THE FORECAST AREA. THE EARLIEST THE CONVECTION COULD OCCUR WOULD BE AROUND 06Z IN THE WEST AND THE REST OF THE AREA EXCEPT YOUNGSTOWN AND ERIE THROUGH THE REST OF THE NIGHT. WILL ADD MENTION OF THE CONVECTION WEST THREE QUARTERS OF THE AREA TONIGHT. .OUTLOOK...VFR SHOULD PREVAIL THROUGH TUESDAY EXCEPT WITH A THREAT OF SHOWERS/THUNDERSTORMS SATURDAY NIGHT AND SUNDAY. && .MARINE... LAKE LOOKS RELATIVELY QUIET OVER THE NEXT SEVERAL DAYS AS WEAK GRADIENT SETS UP OVER THE LAKE AND WEAK STORM SYSTEMS MOVE ACROSS THE AREA. NOT EXPECTING THE NEED TO ISSUE ANY HEADLINES FOR THE LAKE OVER THE NEXT 5 DAYS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ003-006>011- 017>023-027>033-036>038-047. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KUBINA SHORT TERM...KIELTYKA LONG TERM...LOMBARDY AVIATION...LOMBARDY MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
726 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WEAK COLD FRONT WILL SINK SLOWLY SOUTH TOWARD THE OHIO RIVER VALLEY TODAY. A WEAK AREA OF LOW PRESSURE WILL MOVE ACROSS THE REGION ON SATURDAY AND A LOW WILL MOVE ACROSS THE GREAT LAKES ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ON THE 6 AM UPDATE JUST TWEAKED THE CLOUDS FOR THIS AM AND CONTINUED WITH PATCHY DENSE FOG OVER INLAND NORTHWEST PA BECAUSE OF ALL THE RAIN. OTHERWISE STILL ON THE EDGE ABOUT HOW MUCH CONVECTION WILL OCCUR TODAY. ISSUED A HEAT ADVISORY FOR THE WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA. EVEN THOUGH A COLD FRONT HAS MOVES THROUGH...TEMPERATURES WILL RECOVER ESPECIALLY AWAY FROM INFLUENCES OF LAKE ERIE. LOCATIONS IN THE HEAT ADVISORY WILL COME CLOSE TO HEAT INDEX VALUES OF 100. AFTER A VERY WARM NIGHT...TEMPERATURES WILL HEAT UP QUICKLY. WENT WARMER THAN GUIDANCE...USED A MIX OF PRODUCTS. THE POP FORECAST IS TOUGH. THE HRRR MODEL IS TRYING TO INDICATE SOME SHOWERS MOVING THROUGH THE SOUTHERN PORTION OF THE FORECAST ARE TODAY. ON THE EDGE ABOUT THAT. WENT WITH SLIGHT CHANCE POPS WITH THE BOUNDARY SO CLOSE TO THAT AREA. FIRE WEATHER THREAT IS MUCH LOWER TODAY WITH HIGHER HUMIDITIES AND LIGHTER WINDS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE FORECAST IS VERY TOUGH TRYING TO TIME PRECIPITATION. WENT CLOSE TO PREVIOUS FORECAST...A THREAT TONIGHT AS AN MCS MAY COME OUT OF THE MIDWEST AND THEN THE THREAT CONTINUES SATURDAY INTO SUNDAY. A WAVE MOVES ALONG THE FRONT SATURDAY AND THEN A LOW MOVES ACROSS THE GREAT LAKES SUNDAY. WENT ON THE WARMER SIDE OF GUIDANCE. AT THIS TIME NOT EXPECTING TO MEET HEAT ADVISORY CRITERIA DURING THIS PERIOD. && .LONG TERM /TUESDAY THROUGH THURSDAY/... EXTENDED PERIODS COULD BE INTERESTING AS MODELS CONTINUE TO PLACE A STATIONARY FRONT NORTHWEST TO SOUTHEAST ACROSS THE AREA TUESDAY THROUGH THURSDAY MORNING. THIS IS A BIT CONCERNING DUE TO THE SERIES OF UPPER LEVEL POSITIVE VORTICITY MAXIMUMS ROTATING SOUTHEAST ON THE EAST SIDE OF THE UPPER LEVEL RIDGE. THIS COULD POSSIBLY TRANSLATE INTO A PERIOD OF ONE MESO CONVECTIVE SYSTEM AFTER ANOTHER AFFECTING THE FORECAST AREA. WILL HAVE TO MONITOR THE SITUATION TO SEE HOW THINGS DEVELOP. THERE HAS BEEN SOME CONSISTENCY IN THE OVERALL PATTERN OVER THE LAST FEW MODEL RUNS. THE OTHER ISSUE TO DEAL WITH IS THE SUMMER HEAT CONTINUES. INITIALLY...THE STATIONARY FRONT SETS UP ON MONDAY AND REMAINS THERE THROUGH THURSDAY. THIS FRONTAL BOUNDARY COULD MEAN A SPLIT BETWEEN RELIEF FROM THE HOT TEMPERATURES EAST TO CONTINUED HOT TEMPERATURES WEST. WILL MAKE ONLY SOME MINOR ADJUSTMENTS IN TEMPERATURES THROUGH THE EXTENDED PERIODS. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AREA SHOULD BE DRY THROUGH THE DAY. SOME HAZE BEING REPORTED AT AKRON CANTON BUT HAS MINIMAL RESTRICTION TO VISIBILITY. ANOTHER SHOT OF PRECIPITATION IS POSSIBLE LATER TONIGHT AS ANOTHER VORTICITY MAXIMUM MOVES SOUTHEAST ACROSS THE FORECAST AREA. THE EARLIEST THE CONVECTION COULD OCCUR WOULD BE AROUND 06Z IN THE WEST AND THE REST OF THE AREA EXCEPT YOUNGSTOWN AND ERIE THROUGH THE REST OF THE NIGHT. WILL ADD MENTION OF THE CONVECTION WEST THREE QUARTERS OF THE AREA TONIGHT. .OUTLOOK...VFR SHOULD PREVAIL THROUGH TUESDAY EXCEPT WITH A THREAT OF SHOWERS/THUNDERSTORMS SATURDAY NIGHT AND SUNDAY. && .MARINE... LAKE LOOKS RELATIVELY QUIET OVER THE NEXT SEVERAL DAYS AS WEAK GRADIENT SETS UP OVER THE LAKE AND WEAK STORM SYSTEMS MOVE ACROSS THE AREA. NOT EXPECTING THE NEED TO ISSUE ANY HEADLINES FOR THE LAKE OVER THE NEXT 5 DAYS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR OHZ003-006>008-017-018-027-028-036-037-047. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...LOMBARDY AVIATION...LOMBARDY MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
611 AM EDT FRI JUN 29 2012 .SYNOPSIS... A WEAK COLD FRONT WILL SINK SLOWLY SOUTH TOWARD THE OHIO RIVER VALLEY TODAY. A WEAK AREA OF LOW PRESSURE WILL MOVE ACROSS THE REGION ON SATURDAY AND A LOW WILL MOVE ACROSS THE GREAT LAKES ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ON THE 6 AM UPDATE JUST TWEAKED THE CLOUDS FOR THIS AM AND CONTINUED WITH PATCHY DENSE FOG OVER INLAND NORTHWEST PA BECAUSE OF ALL THE RAIN. OTHERWISE STILL ON THE EDGE ABOUT HOW MUCH CONVECTION WILL OCCUR TODAY. ISSUED A HEAT ADVISORY FOR THE WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA. EVEN THOUGH A COLD FRONT HAS MOVES THROUGH...TEMPERATURES WILL RECOVER ESPECIALLY AWAY FROM INFLUENCES OF LAKE ERIE. LOCATIONS IN THE HEAT ADVISORY WILL COME CLOSE TO HEAT INDEX VALUES OF 100. AFTER A VERY WARM NIGHT...TEMPERATURES WILL HEAT UP QUICKLY. WENT WARMER THAN GUIDANCE...USED A MIX OF PRODUCTS. THE POP FORECAST IS TOUGH. THE HRRR MODEL IS TRYING TO INDICATE SOME SHOWERS MOVING THROUGH THE SOUTHERN PORTION OF THE FORECAST ARE TODAY. ON THE EDGE ABOUT THAT. WENT WITH SLIGHT CHANCE POPS WITH THE BOUNDARY SO CLOSE TO THAT AREA. FIRE WEATHER THREAT IS MUCH LOWER TODAY WITH HIGHER HUMIDITIES AND LIGHTER WINDS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE FORECAST IS VERY TOUGH TRYING TO TIME PRECIPITATION. WENT CLOSE TO PREVIOUS FORECAST...A THREAT TONIGHT AS AN MCS MAY COME OUT OF THE MIDWEST AND THEN THE THREAT CONTINUES SATURDAY INTO SUNDAY. A WAVE MOVES ALONG THE FRONT SATURDAY AND THEN A LOW MOVES ACROSS THE GREAT LAKES SUNDAY. WENT ON THE WARMER SIDE OF GUIDANCE. AT THIS TIME NOT EXPECTING TO MEET HEAT ADVISORY CRITERIA DURING THIS PERIOD. && .LONG TERM /TUESDAY THROUGH THURSDAY/... EXTENDED PERIODS COULD BE INTERESTING AS MODELS CONTINUE TO PLACE A STATIONARY FRONT NORTHWEST TO SOUTHEAST ACROSS THE AREA TUESDAY THROUGH THURSDAY MORNING. THIS IS A BIT CONCERNING DUE TO THE SERIES OF UPPER LEVEL POSITIVE VORTICITY MAXIMUMS ROTATING SOUTHEAST ON THE EAST SIDE OF THE UPPER LEVEL RIDGE. THIS COULD POSSIBLY TRANSLATE INTO A PERIOD OF ONE MESO CONVECTIVE SYSTEM AFTER ANOTHER AFFECTING THE FORECAST AREA. WILL HAVE TO MONITOR THE SITUATION TO SEE HOW THINGS DEVELOP. THERE HAS BEEN SOME CONSISTENCY IN THE OVERALL PATTERN OVER THE LAST FEW MODEL RUNS. THE OTHER ISSUE TO DEAL WITH IS THE SUMMER HEAT CONTINUES. INITIALLY...THE STATIONARY FRONT SETS UP ON MONDAY AND REMAINS THERE THROUGH THURSDAY. THIS FRONTAL BOUNDARY COULD MEAN A SPLIT BETWEEN RELIEF FROM THE HOT TEMPERATURES EAST TO CONTINUED HOT TEMPERATURES WEST. WILL MAKE ONLY SOME MINOR ADJUSTMENTS IN TEMPERATURES THROUGH THE EXTENDED PERIODS. && .AVIATION /10Z FRIDAY THROUGH TUESDAY/... CONVECTION THAT DEVELOPED OVER NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA CONTINUES TO MOVE SOUTHEAST AS IT DEVELOPS INTO AN MESO CONVECTIVE SYSTEM. THIS CLUSTER OF STORMS WAS ASSOCIATED WITH A RATHER POTENT VORTICITY MAXIMUM MOVING SOUTHEAST ACROSS THE EASTERN AREAS. THIS FEATURE WILL CONTINUE TO MOVE SOUTHEAST AND OUT OF THE AREA THIS MORNING. REST OF THE AREA SHOULD BE DRY OVERNIGHT EVEN THOUGH DEW POINTS REMAIN ELEVATED IN THE UPPER 60S TO LOWER 70S. EXPECTING DRY VFR CONDITIONS THROUGH THE DAY TODAY BUT ANOTHER SHOT OF PRECIPITATION IS POSSIBLE LATER TONIGHT AS ANOTHER VIGOROUS VORTICITY MAXIMUM MOVES SOUTHEAST ACROSS THE FORECAST AREA. THE EARLIEST THE CONVECTION COULD OCCUR WOULD BE AROUND 06Z IN THE WEST AND THE REST OF THE AREA THROUGH THE REST OF THE NIGHT. .OUTLOOK...VFR SHOULD PREVAIL THROUGH TUESDAY EXCEPT WITH A THREAT OF SHOWERS/THUNDERSTORMS SATURDAY NIGHT AND SUNDAY. && .MARINE... LAKE LOOKS RELATIVELY QUIET OVER THE NEXT SEVERAL DAYS AS WEAK GRADIENT SETS UP OVER THE LAKE AND WEAK STORM SYSTEMS MOVE ACROSS THE AREA. NOT EXPECTING THE NEED TO ISSUE ANY HEADLINES FOR THE LAKE OVER THE NEXT 5 DAYS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR OHZ003-006>008-017-018-027-028-036-037-047. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...LOMBARDY AVIATION...LOMBARDY MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
650 AM CDT FRI JUN 29 2012 .SHORT TERM...TODAY THROUGH SUNDAY NIGHT 319 AM CDT FRI JUN 29 2012 MAIN FORECAST CONCERN IS PRECIPITATION CHANCES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED SUBTROPICAL RIDGING COVERING MUCH OF THE SOUTHERN U.S. WITH A RIDGE AXIS EXTENDING FROM EASTERN WYOMING INTO EASTERN ALBERTA. THE FORECAST AREA LIES IN WEST-NORTHWEST FLOW DOWNSTREAM OF THE RIDGE AXIS. PLENTY OF DRY AIR SEEN ON WATER VAPOR INDICATING SUBSIDENCE IN PLACE...LEADING TO THE QUIET OVERNIGHT THUS FAR. 00Z MPX AND GRB SOUNDINGS SHOWED THE DRY...SUBSIDENT AIR QUITE NICELY WITH PRECIPITABLE WATER VALUES AROUND 0.77 INCHES OR 85 PERCENT OF NORMAL. JUST TO OUR SOUTH...A STREAM OF MOISTURE CAN BE SEEN IN WATER VAPOR OVER SOUTHERN IOWA. BIG DIFFERENCE WHEN IT COMES TO PRECIPITABLE WATER IN THIS MOISTURE STREAM COMPARED TO MPX...WITH THE 00Z OAX AND DVN SOUNDINGS SHOWING VALUE AROUND 2 INCHES OR NEARLY 200 PERCENT OF NORMAL. THIS HIGH AMOUNT OF MOISTURE IS REFLECTED TOO AT THE SURFACE WITH DEWPOINTS BETWEEN 75-80F ALONG A LINE BETWEEN HASTINGS NEBRASKA AND PEORIA ILLINOIS. THE MORE TROPICAL MOISTURE IS SITTING JUST NORTH OF A STATIONARY FRONTAL BOUNDARY. ALONG THE FRONTAL BOUNDARY...VARIOUS CLUSTERS OF STORMS HAVE BEEN TRACKING ACROSS NEBRASKA THROUGH THE OVERNIGHT HOURS. THESE HAVE BEING AIDED BY 925-850MB MOISTURE TRANSPORT OVER WESTERN KANSAS. ONE OF THE CLUSTERS CROSSING CENTRAL NEBRASKA HAS AN MCV WITH IT. ANOTHER ZONE OF 850MB MOISTURE TRANSPORT IS NOTED OVER IOWA...GOING OVER TOP OF THE FRONT...PER VWP DATA. SO FAR NO CONVECTION HAS FIRED ON THE NOSE OF THIS TRANSPORT...THOUGH SOME 4000-6000 FT CLOUD BASES ARE PRESENT. FINALLY...TO THE WEST...A WEAK SHORTWAVE WAS NOTED OVER EASTERN MONTANA GOING THROUGH THE RIDGE AXIS...WITH SOME LIGHTNING ACCOMPANYING IT. TODAY AND TONIGHT...FORECAST IS A LITTLE DIFFICULT RIGHT OFF THE BAT WITH MOST MODELS STRUGGLING TO CAPTURE THE CONVECTION IN NEBRASKA. FIRST...IN GENERAL WITH THE UPPER FLOW...MODELS PROG THE RIDGE AXIS OVER THE NORTHERN ROCKIES TO SHIFT EAST INTO THE WESTERN DAKOTAS BY 12Z SATURDAY. THERE ARE ALSO SIGNALS FROM ALL MODELS THAT SOME FORM OF WEAK TROUGHING WILL BE OVER THE FORECAST AREA AT 12Z SATURDAY. THIS TROUGHING APPEARS TO FORM FROM A RESULT OF THE EASTERN MONTANA SHORTWAVE AND THE MCV MOVING THROUGH/BY THE AREA. MAIN QUESTION IS WILL ANY PRECIPITATION OCCUR AS THESE SHORTWAVES PASS BY OR MOVE THROUGH. ONGOING NEBRASKA CONVECTION SHOULD DIMINISH THIS MORNING AS IT ENTERS NORTHWEST MO/SOUTHWEST IOWA WITH THE WEAKENING OF THE LOW LEVEL JET. FOCUS FOR THIS MORNING IS ALSO ON THE ZONE OF 850MB MOISTURE TRANSPORT OVER IOWA. POTENTIAL DOES EXIST FOR CONVECTION TO FIRE ON THE NOSE OF IT BETWEEN 09-12Z OVER NORTHERN IOWA. ALSO... THERE APPEARS TO BE AN UPPER JET STREAK CROSSING I-90 THIS MORNING...WHICH IS CURRENTLY IN SOUTHWEST MINNESOTA. THIS WOULD GIVE A BRIEF UPPER DIVERGENCE SURGE. SHOULD CONVECTION GO...CAPE VALUES LIFTED FROM 850MB ARE NEAR 3000 J/KG WITH NO CIN AND 1-6 KM SHEAR NEAR 40 KT...SUGGESTING POTENTIAL FOR ORGANIZED SEVERE STORMS. THIS MOISTURE TRANSPORT BENDS MORE WEST AND NORTHWEST THROUGH THE MORNING...SUGGESTING ANY CONVECTION WOULD PROBABLY BE OVER WITH BY 15Z. ATTENTION THEN TURNS TO THE EASTERN MONTANA SHORTWAVE...LIKELY COMING AT THE AREA DURING THE AFTERNOON AND EVENING. IF CONVECTION DOES NOT FIRE EARLY THIS MORNING...CONVECTION COULD FIRE UP ALONG/SOUTH OF I-90 LATE THIS AFTERNOON AND EVENING WITH THIS SHORTWAVE. 0-6KM SHEAR FOR THE AFTERNOON/EVENING IS AROUND 30 KT...SUGGESTING MAYBE SOME ORGANIZED MULTI-CELL CONVECTION...WHICH COULD POSE AT MOST A RISK FOR DAMAGING WINDS. OVERALL..CONFIDENCE NOT THAT HIGH FOR SEVERE THIS AFTERNOON/EVENING. IN FACT...OVERALL CONFIDENCE ON THIS PRECIPITATION FORECAST IS LOW...REFLECTED BY THE 20-40 PERCENT PROBABILITIES. SATURDAY THROUGH SUNDAY NIGHT...PRECIPITATION FORECAST REMAINS TRICKY. MODELS ARE IN GOOD AGREEMENT THAT THE RIDGE AXIS WILL REMAIN OVER THE DAKOTAS...WITH SOME SUGGESTION OF MORE AMPLIFICATION TOWARDS SUNDAY NIGHT AS A MORE POTENT SHORTWAVE CROSSES THE NORTHERN ROCKIES. THE UPPER FLOW STAYS WEST-NORTHWESTERLY OVER THE FORECAST AREA...MEANING THAT THE SURFACE FRONTAL BOUNDARY WILL LIKELY HOVER AROUND I-80 IN IOWA. MODELS ARE PRODUCING A VARIETY OF SHORTWAVES THAT RIDE ALONG THE BOUNDARY...SOME WHICH MIGHT BE REAL AND OTHERS CONVECTIVELY INDUCED. GIVEN THE PLENTIFUL INSTABILITY AROUND THE BOUNDARY...ANY SHORTWAVE COULD BRIEFLY SURGE THIS INSTABILITY NORTH INTO SOUTHERN PORTIONS OF THE FORECAST AREA AND INITIATE CONVECTION. HOWEVER...THE BULK OF ANY CONVECTION SHOULD STAY SOUTH OF THE FORECAST AREA CLOSER TO THE INSTABILITY. ENOUGH CONFIDENCE EXISTS TO REMOVE PRECIPITATION CHANCES ON SATURDAY WITH ALL MODELS FOCUSING ANY 850MB MOISTURE TRANSPORT AND SURFACE FRONTAL CONVECTION SOUTH OF THE AREA. 20 PERCENT CHANCES EXIST ACROSS MUCH OF THE FORECAST AREA SATURDAY NIGHT AND SUNDAY WITH SUGGESTIONS THAT THE 850MB MOISTURE TRANSPORT SURGES BACK NORTH. SUNDAY NIGHT STILL LOOKS OKAY TO HAVE A DRY FORECAST WITH LITTLE OR NO MOISTURE TRANSPORT...OR SHORTWAVE SUGGESTED TO KICK OFF CONVECTION. TEMPERATURES...THROUGHOUT THE SHORT TERM...925MB AND 850MB READINGS DO NOT CHANGE A WHOLE LOT DAY TO DAY...RUNNING BETWEEN 22-26C AND 18-22C RESPECTIVELY AT 18Z. COOLEST 925MB AND 850MB TEMPS ARE SUGGESTED OVER CENTRAL WISCONSIN. GIVEN POTENTIAL TO SEE QUITE A FEW HOURS OF SUN EACH DAY...HIGHS SHOULD STAY FAIRLY CONSISTENT. SAME GOES FOR LOWS TOO WITH LITTLE ADVECTION EXPECTED. DEWPOINTS DO NOT SEEM TO GET HIGH ENOUGH SOUTH OF I-90 TO WARRANT ANY HEAT ADVISORY HAZARD. RIGHT NOW...ANTICIPATING MAX HEAT INDICES BETWEEN 90-95. .LONG TERM...MONDAY THROUGH THURSDAY NIGHT 319 AM CDT FRI JUN 29 2012 GENERAL THEME FROM THE 29.00Z ECMWF...CANADIAN...UKMET...GFS AND GFS ENSEMBLES...AS WELL AS THEIR PREVIOUS RUNS...IS TO SUGGEST THE SUBTROPICAL RIDGE BUILDING AND EXPANDING NORTHWARD. HOWEVER...THERE IS ONE HUGE DIFFERENCE...WHERE THE ECMWF RUNS ALLOW THE RIDGING TO BUILD UP INTO THE FORECAST AREA WHEREAS ALL OTHER MODELS HAVE SOME FORM OF TROUGHING INDICATED OVER THE GREAT LAKES. THIS CREATES HAVOC FOR BOTH TEMPERATURE AND PRECIPITATION FORECASTING. SHOULD THE ECMWF RUNS BE CORRECT...MUCH IF NOT ALL OF THE LONG TERM IS DRY AND HOT WITH HIGHS LIKELY EACH DAY FROM THE MID 90S TO LOW 100S BEGINNING TUESDAY. ON THE OTHER HAND...OTHER MODELS CAN HAVE A SERIES OF SHORTWAVES AND FRONTS DROPPING THROUGH A NORTHWEST FLOW...ONE OF WHICH IS PROMINENTLY DISPLAYED FOR TUESDAY. FOR NOW...PRETTY MUCH STAYED WITH A CONSENSUS BLEND UNTIL MODELS CAN BECOME IN BETTER AGREEMENT. THIS RESULTS IN PRETTY MUCH EVERY 12 HOUR PERIOD HAVING AROUND A 20 PERCENT CHANCE OF PRECIPITATION WITH HIGHS IN THE MID 80S TO LOWER 90S. WE DEFINITELY HAVE TO WATCH THE LONG TERM PERIOD FOR A HEAT WAVE...SEEING TOO SOME SUPPORT FROM THE CFS TO GO ALONG WITH THE ECMWF. && .AVIATION...TODAY AND TONIGHT 646 AM CDT FRI JUN 29 2012 A SERIES OF WEAK WAVES OF LOW PRESSURE WILL MOVE EAST SOUTHEAST ACROSS SOUTHWEST MINNESOTA AND IOWA. THESE SYSTEMS WILL PROVIDE A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY SOUTH OF THE INTERSTATE 90 CORRIDOR. AS A RESULT...KEPT THE FORECAST DRY AT BOTH TAF SITES. SOME BLOW OFF FROM THESE STORMS WILL PRODUCE CEILINGS GENERALLY ABOVE 12K FEET. && .ARX WATCHES/WARNINGS/ADVISORIES... 650 AM CDT FRI JUN 29 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
307 PM CDT FRI JUN 29 2012 .DISCUSSION... ISSUED 307 PM CDT FRI JUN 29 2012 MAIN CONCERNS CONTINUE TO BE CHANCE OF PCPN AND LOCATION AS MOST OF THE CWA SITS UNDER A HEAT DOME. OVERALL...MODELS IN GOOD AGREEMENT WITH LARGE SCALE FEATURES BUT HAVE TROUBLE WITH THE SMALLER SCALE FEATURES THAT WOULD AFFECT PCPN TIMING AND LOCATION AS WELL AS HIGH TEMPS THROUGH DURING THE AFTERNOON. SHORT TERM...HRRR MODEL...LOOKS TO BE DOING QUITE WELL WITH LOCATION OF SOME OF THESE SMALLER FEATURES AND RESULTING PCPN. SO THROUGH TONIGHT WE WILL FOLLOW THE HRRR AND THEN SWITCH TO NAM-WRF/ECMWF. GFS REMAINS TOO WET. SHORT TERM...TONIGHT THROUGH MONDAY CONVECTION OUT OVER IOWA WILL BEGIN TO INCREASE LATE THIS AFTERNOON AND SLOWLY SLIDE EAST INTO NRN IL. SO CHC POPS IN THE NORTHERN THIRD OF THE CWA LOOKS GOOD FOR THIS EVENING AND INTO OVERNIGHT. THIS SHOULD HELP TO KEEP THE FRONT ACROSS THE NORTHERN PART OF THE CWA INTO TOMORROW. SO WILL KEEP CHC POPS IN THE NORTH FOR TOMORROW. BEST SCIENTIFIC GUESS RIGHT NOW IS FOR THE FRONT TO REMAIN IN THAT GENERAL AREA THROUGH TOMORROW AND THEN SLOWLY PUSH NORTH TOMORROW NIGHT AND REMAIN UP THERE THROUGH SUNDAY. SO WILL KEEP CHC POPS NEAR THE FRONT AND HAVE SLIGHT CHC POPS TO THE SOUTH OF THE FRONT...REMAINING IN THE EXTREME NORTH PARTS OF THE CWA...THROUGH MONDAY. WARM TEMPS WILL CONTINUE THROUGH THE PERIOD WITH WARMEST TEMPS IN THE SOUTH HALF OF THE CWA. 90S ARE STILL EXPECTED IN THE NORTH BUT CLOUDS AND PCPN WILL KEEP THEM DOWN A TAD. HIGHEST DEWPOINTS WILL BE NORTH WITH THE FRONT WITH DRIER AIR DOWN WITH THE WARMEST TEMPS. THIS COMBINATION OF DEWPOINTS AND TEMPS WILL CONTINUE THE HEAT INDEX VALUES AROUND 105 THROUGH SUNDAY...ESPECIALLY IN THE SOUTHERN HALF OF THE CWA. THE NORTHERN AREAS COULD STILL REACH TO 100 FOR HEAT INDEX...BUT WITH THE HIGHER HUMIDITY OPPRESSIVE CONDITIONS WILL CONTINUE THERE AS WELL. SO SINCE THIS WILL GO THROUGH SUNDAY AND REACH 4 DAYS...HAVE CANCELLED REPLACED THE ADVISORY WITH AN EXCESSIVE HEAT WARNING. IF CRITERIA IS NOT BEING REACHED IN THE NORTH...THEN LATER SHIFTS CANCEL AS THE NEED ARISES. HEAT INDICES AT NIGHT SHOULD REMAIN ABOVE 75 AS WELL. COMPROMISED OF GUIDANCE LOOKS BEST AND RAISED TEMPS A LITTLE IN THE NORTH. LONG TERM...MONDAY NIGHT THROUGH FRIDAY RIDGING OVER THE MIDDLE PART OF THE US WILL REMAIN IN PLACE THROUGH THE WEEK WITH WEAK IMPULSES RIDING ALONG THE NORTHERN EDGE OF THE RIDGE. PCPN IS POSSIBLE BUT TIMING AND LOCATION IS VERY DIFFICULT TO PREDICT THIS FAR OUT. SO HAVE OPTED WITH DRY FORECAST THROUGH FRIDAY UNTIL BETTER SIGNALS SHOW WHEN PCPN WILL BE. TEMPS SHOULD REMAIN WARM IN THE MIDDLE TO UPPER 90S...WHICH IS WARMER THAN GUIDANCE. AUTEN && .AVIATION... ISSUED 1244 PM CDT FRI JUN 29 2012 CONVECTIVE OUTFLOW BOUNDARY WILL CONTINUE TO SETTLE SOUTHWARD ACROSS NORTH-CENTRAL ILLINOIS EARLY THIS AFTERNOON...BEFORE EVENTUALLY STALLING AND MIXING BACK NORTHWARD LATER IN THE DAY. LATEST SATELLITE/RADAR IMAGERY SHOWS THE BOUNDARY STRETCHING FROM NEAR KBMI TO JUST NORTH OF KMQB. BASED ON THE CURRENT POSITION AND THE 14Z HRRR FORECAST...HAVE GONE WITH GUSTY N/NE WINDS AT BOTH KPIA AND KBMI THROUGH 20Z...THEN HAVE VEERED THE WINDS BACK TO S/SW AT THOSE SITES AFTER 22Z. FURTHER SOUTH...WILL MAINTAIN WESTERLY WINDS OF AROUND 10KT THROUGH THE AFTERNOON. W/SW WINDS WILL RESUME ACROSS THE BOARD TONIGHT INTO SATURDAY MORNING. ADDITIONAL CONVECTION MAY RE-DEVELOP IN THE VICINITY OF A STATIONARY FRONTAL BOUNDARY DRAPED ALONG THE I-80 CORRIDOR OVERNIGHT...HOWEVER THINK THIS WILL MAINLY STAY NORTH OF THE KILX TERMINALS. LATER FORECASTS MAY NEED TO ADJUST FOR CLOUD COVER/WIND DIRECTION AS OUTFLOW FROM ANY STORMS TO THE NORTH MAY IMPACT THE I-74 TAF SITES. AT THIS POINT...UNCERTAINTY IS TOO GREAT TO INCLUDE THESE POTENTIAL MESOSCALE DETAILS IN THE FORECAST. BARNES && .ILX WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SUNDAY FOR ILZ027>031- 036>038-040>057-061>063-066>068-071>073. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1244 PM CDT FRI JUN 29 2012 .DISCUSSION... ISSUED 1034 AM CDT FRI JUN 29 2012 ANOTHER EXTREMELY HOT DAY IS UNFOLDING ACROSS CENTRAL AND SOUTHEAST ILLINOIS...WITH 15Z TEMPS ALREADY WELL INTO THE 90S ACROSS THE SE KILX CWA. READINGS ARE SLIGHTLY COOLER ACROSS THE FAR NORTH...WHERE A FEW CLOUDS AND HIGHER DEWPOINTS ARE KEEPING TEMPS DOWN JUST A BIT. FRONTAL BOUNDARY THAT SAGGED SOUTHWARD TO NEAR THE I-74 CORRIDOR LAST NIGHT IS LIFTING BACK NORTHWARD...KEEPING THE BEST CHANCES FOR CONVECTION CONFINED TO NORTHERN ILLINOIS. LATEST SATELLITE/RADAR IMAGERY CONTINUES TO SHOW DEVELOPING STORM COMPLEX TRACKING EASTWARD ALONG THE I-80 CORRIDOR. SOME OF THE HIGHER-RES MODELS SUCH AS THE 11Z HRRR SUGGEST THIS COMPLEX WILL EVENTUALLY BECOME SURFACE-BASED AND TAKE A TURN E/SE ALONG THE BOUNDARY. BASED ON LATEST TRENDS...IT APPEARS THAT BY THE TIME THIS HAPPENS THE STORMS WILL LIKELY MISS THE KILX CWA TO THE N/NE...EVENTUALLY SPILLING SOUTHEASTWARD INTO NORTH-CENTRAL INDIANA THIS AFTERNOON. ONLY CHANCE FOR CONVECTION ACROSS CENTRAL ILLINOIS WOULD BE POSSIBLE ISOLATED STORMS ALONG RESIDUAL OUTFLOW BOUNDARY LATER TODAY. HAVE THEREFORE TRIMMED POPS CONSIDERABLY...FEATURING ONLY A SLIGHT CHANCE ALONG/NORTH OF I-74. TEMP FORECAST LOOKS PRETTY MUCH ON TRACK...WITH HIGHS RANGING FROM THE MID 90S FAR NORTH AROUND LACON TO OVER 105 DEGREES ALONG/SOUTH OF I-70. && .AVIATION... ISSUED 1244 PM CDT FRI JUN 29 2012 CONVECTIVE OUTFLOW BOUNDARY WILL CONTINUE TO SETTLE SOUTHWARD ACROSS NORTH-CENTRAL ILLINOIS EARLY THIS AFTERNOON...BEFORE EVENTUALLY STALLING AND MIXING BACK NORTHWARD LATER IN THE DAY. LATEST SATELLITE/RADAR IMAGERY SHOWS THE BOUNDARY STRETCHING FROM NEAR KBMI TO JUST NORTH OF KMQB. BASED ON THE CURRENT POSITION AND THE 14Z HRRR FORECAST...HAVE GONE WITH GUSTY N/NE WINDS AT BOTH KPIA AND KBMI THROUGH 20Z...THEN HAVE VEERED THE WINDS BACK TO S/SW AT THOSE SITES AFTER 22Z. FURTHER SOUTH...WILL MAINTAIN WESTERLY WINDS OF AROUND 10KT THROUGH THE AFTERNOON. W/SW WINDS WILL RESUME ACROSS THE BOARD TONIGHT INTO SATURDAY MORNING. ADDITIONAL CONVECTION MAY RE-DEVELOP IN THE VICINITY OF A STATIONARY FRONTAL BOUNDARY DRAPED ALONG THE I-80 CORRIDOR OVERNIGHT...HOWEVER THINK THIS WILL MAINLY STAY NORTH OF THE KILX TERMINALS. LATER FORECASTS MAY NEED TO ADJUST FOR CLOUD COVER/WIND DIRECTION AS OUTFLOW FROM ANY STORMS TO THE NORTH MAY IMPACT THE I-74 TAF SITES. AT THIS POINT...UNCERTAINTY IS TOO GREAT TO INCLUDE THESE POTENTIAL MESOSCALE DETAILS IN THE FORECAST. BARNES && .PREV DISCUSSION... ISSUED 317 AM CDT FRI JUN 29 2012 AT 06Z SFC FRONT HAD STALLED ALONG THE IA/MO BORDER EAST TO NEAR KPIA AND INTO NORTHERN IND. MID/UPPER 70S DEWPOINTS POOLED ALONG THE BOUNDARY. ALOFT...A LARGE MID LEVEL RIDGE OCCUPIED MUCH OF THE SOUTHERN HALF OF THE COUNTRY WHILE A FAST ZONAL FLOW WAS FARTHER NORTH. WATER VAPOR IMAGERY INDICATED SUBTROPICAL MOISTURE PLUME FROM THE DESERT SW UP INTO THE CENTRAL PLAINS AND ACROSS THE LOCAL AREA...ON THE PERIPHERY OF THE RIDGE. FORECAST CONCERNS REMAIN HIGH HEAT THROUGH THE PERIOD AND CONVECTION CHANCES IN RING OF FIRE PATTERN ON NORTHERN FRINGE OF THE RIDGE. SHORT TERM...TODAY THROUGH SUNDAY LOW CONFIDENCE FORECAST IN CONVECTIVE TRENDS NEXT FEW DAYS AS MESOSCALE FEATURES DRIVE THUNDERSTORM ACTIVITY. NORTHERN CWA WILL BE IN CLOSER PROXIMITY TO FAVORABLE SYNOPTIC FEATURES...SFC BOUNDARY AND STRONGER MID LEVEL FLOW/SHORTWAVE ENERGY TRACK. HIGH INSTABILITY...MODERATE SHEAR...AND HIGH PRECIPITABLE WATER WILL LEAD TO POTENTIAL FOR SEVERE MCS/S AND LOCALLY HEAVY RAIN WHICH MAY IMPACT OR STAY JUST NORTH OF THE CWA. FOR THESE REASONS WILL KEEP LOW CHC POPS GOING PRIMARILY NORTH OF A CANTON TO BLOOMINGTON THROUGH SATURDAY NIGHT...TAPERING TO SLIGHT CHC CENTRAL. A STRONGLY CAPPED AIRMASS SHOULD SUPPRESS ANY DEVELOPMENT ACROSS THE SOUTH HALF. HIGHER CONFIDENCE IN TEMPERATURES WHICH WILL STAY VERY HOT THROUGH THIS WEEKEND. IN FACT TODAYS READINGS MAY NOT BE FAR OFF YESTERDAYS NUMBERS WHICH WERE 100+ FOR MUCH OF THE AREA. TEMPS COOL ONLY A FEW DEGREES THIS WEEKEND WITH HIGHS STILL IN THE MID OR UPPER 90S NORTH AND LOW 100S SOUTH. APPARENT TEMPS ONLY DROPPING INTO THE UPPER 70S TONIGHT WILL REQUIRE EXTENDING HEAT ADVISORY TO 12Z SATURDAY. AREAS SOUTH OF I-70 LOOK TO BE BORDERLINE FOR ADVISORY CRITERIA AGAIN ON SATURDAY AFTERNOON AND ADVISORY MAY NEED TO BE EXTENDED HERE IN LATER FORECASTS. LONG TERM...MONDAY THROUGH THURSDAY UNFORTUNATELY NO PROSPECTS FOR A MAJOR PATTERN CHANGE IN THE EXTENDED TO BRING COOLER AIR INTO THE MIDWEST. LATEST GUIDANCE SUGGESTS MID LEVEL RIDGING SHIFTING EVEN FARTHER NORTH THROUGH THE WEEK. THIS WOULD DRIVE MCS TRACK FARTHER NORTH LEAVING A DRY AND HOT FORECAST FOR THE ENTIRE CWA THROUGH THURSDAY. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR ILZ027>031-036>038- 040>057-061>063-066>068-071>073. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
309 PM CDT FRI JUN 29 2012 .SYNOPSIS... 12Z UA ANALYSIS HAD AN IMPLIED 850MB WARM FRONT RUNNING FROM NORTHERN NEBRASKA INTO NORTHEAST MISSOURI. MOISTURE WAS POOLING NORTH OF THIS BOUNDARY ACROSS IOWA AND ILLINOIS WITH DEW POINTS IN THE MID TEENS TO LOWER 20S. SATELLITE IMAGERY THROUGH EARLY AFTERNOON HAS THE MORNING CONVECTION WELL EAST OF THE AREA WITH NEW CONVECTION DEVELOPING AS A RESULT OF AN MCV IN WESTERN IOWA. TRENDS IN SATELLITE/RADAR THE PAST FEW HOURS SHOWS CONVECTION SLOWLY GETTING STRONGER. 18Z SFC ANALYSIS IS EXTREMELY NOISY WITH NUMEROUS MESOSCALE FEATURES. A WAKE LOW WAS NEAR KRFD WITH A MESO LOW OVER THE NORTHWEST PARTS OF THE KDSM METRO AREA. OUTFLOW BOUNDARIES WERE ACROSS THE SOUTHERN CWFA WITH ANOTHER WEAK BOUNDARY MOVING SOUTH FROM THE KDSM LOW TO NEAR KTVK. DEW POINTS WERE GENERALLY IN THE 60S WITH POCKETS OF 70 DEW POINTS IN WESTERN IOWA AND ALONG THE OUTFLOW BOUNDARY IN THE SOUTHERN CWFA. && .SHORT TERM...TONIGHT AND SATURDAY NONLINEAR PROCESSES ARE DOMINATING THE SENSIBLE WX. AS SUCH ANALYSIS OF TRENDS AND CONCEPTUAL MODELS WERE USED HEAVILY FOR THE IMMEDIATE TERM. INPUT FROM RAP MODEL TRENDS USING THE MCS AND LIFT TOOLS HELPED A LITTLE TOO. TRENDS FROM THE RAP MODEL SUGGEST CONVECTION WILL CONTINUE TO DEVELOP AND STRENGTHEN ACROSS SOUTHERN IOWA THE NEXT SEVERAL HOURS. MCS TOOL SUGGESTS THE COLLISION OF THE OUTFLOW BOUNDARY WITH THE APPROACHING BOUNDARY FROM THE MESO LOW WILL INITIATE CONVECTION THAT MOVES INTO THE CWFA LATE THIS AFTERNOON. SAID CONVECTION SHOULD EVOLVE INTO A LINEAR MCS THAT MOVES EAST AND SOUTH DURING THE EVENING HOURS. THE POTENTIAL ENERGY BUILT UP IN THE CLEAR AREAS ACROSS SOUTHERN IOWA SHOULD ALLOW THE STORMS TO BECOME QUITE STRONG. SEVERE STORMS MAY BE POSSIBLE LATE THIS AFTERNOON AND EVENING WITH THE NEW CONVECTION. TRENDS OVER THE NEXT FEW HOURS WILL BE THE KEY TO WHAT HAPPENS. LATER TONIGHT...THE MCS AND LIFT TOOLS ARE SUGGESTING YET ANOTHER MCS WILL DEVELOP OUT WEST AND MOVE INTO THE AREA. EFFECTIVE BOUNDARIES LEFT OVER FROM THE EARLIER CONVECTION SHOULD DICTATE WHERE THIS CONVECTION GOES. REGARDLESS...THIS CONVECTION SHOULD BE ANOTHER LINEAR MCS. IF THIS MCS CAN BECOME SURFACE BASED...THE DIFFERENTIAL THETA E SUGGESTED IN THE MODELS WOULD SUPPORT SEVERE STORMS WITH WIND...POSSIBLY EXTREME...BEING THE PRIMARY THREAT. THIS SECOND MCS SHOULD BE IN A DECAYING MODE OR EXITING THE CWFA SATURDAY MORNING. COLD POOLS LEFT OVER FROM THIS MCS ALONG WITH OUTFLOW BOUNDARIES WOULD THEN PROVIDE THE FOCUS FOR NEW CONVECTION SATURDAY AFTERNOON. AS FOR THE HEAT HEADLINES...THE OUTFLOW BOUNDARY FROM CONVECTION THIS MORNING HAS HELPED HOLD DOWN TEMPERATURES SOMEWHAT ACROSS THE SOUTH. FOR NOW WILL CONTINUE WITH THE CURRENT HEADLINES BUT CONVECTION LATE THIS AFTERNOON/EVENING MAY RESULT IN THE HEAT ADVISORY BEING CANCELLED FOR MOST IF NOT ALL OF THE AREA. ..08.. .LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY... ABOVE NORMAL TEMPERATURES TO CONTINUE AND HUMID WITH A CHANCE OF THUNDERSTORMS INTO MONDAY. OVERVIEW...CONCERNS OF NON-LINEAR CONVECTION AND OUTFLOW BOUNDARIES AS HAVE OCCURRED TODAY AND DISCUSSED YESTERDAY TO REMAIN A MAJOR CHALLENGE INTO MONDAY. INITIALIZATION ADEQUATE WITH VERIFICATION SUGGESTING AN OVERWEIGHT OF GFS AND NAM-WRF. CONVECTION THIS PM AND TONIGHT WILL IMPACT NEXT ROUND OF CONVECTION TOMORROW NIGHT INTO SUNDAY AS WELL AS TEMPERATURES...JUST LIKE TODAY. AGAIN...TIMING AND LOCATION OF PRECIPITATION WILL BE HARD TO CLARIFY BEYOND 6-12 HOURS AHEAD DUE TO NON-LINEAR NATURE AND OUTFLOW BOUNDARIES IMPACTING SUBSEQUENT CONVECTION EVENTS. HIGH TO EXTREME STABILITY IS STILL INDICATED INTO MONDAY WITH MUCAPES OF 2500 TO 4000+ J/KG...MAX DIFFERENTIAL THETA_E OF 30C...POSSIBLY MORE AND WBZ 12-14K AGL SUPPORTIVE OF RISK OF DAMAGING TO VERY DAMAGING STRAIGHT LINE WINDS. THE NEXT COUPLE OF DAYS MAY SEE REPORTS OF 80+ MPH WINDS NEAR OR IN OUR FORECAST AREA DUE TO THIS HIGH TO EXTREME INSTABILITY. THIS HAS NOW OCCURRED TODAY WITH OUR CONVECTION THIS MORNING NOW MOVING EAST INTO NORTHERN INDIANA AS A BOWING SYSTEM AND IS BECOMING A DERECHO WITH FORT WAYNE AIRPORT REPORTING MEASURED WIND GUSTS OF 79 KTS...OR 91 MPH. TEMPERATURES TO STAY ABOVE NORMAL BY 5 TO 10 DEGREES THROUGH NEXT WEEK. SATURDAY NIGHT THROUGH SUNDAY...UPPED POPS WITH ANOTHER ROUND OF CONVECTION SUGGESTED...MAINLY FOR SOUTH 1/2 OF AREA. KEY WILL BE STRENGTH OF OUTFLOW FROM MCS TONIGHT INTO SATURDAY. NORTH SECTIONS SHOULD STAY NORTH OF OF COOL POOL OUTFLOW AND SUPPORTIVE OF HIGHS 90 DEGREES AND POSSIBLY ONLY MID 80S FOR LATER SHIFTS ON SUNDAY. MINS SATURDAY NIGHT MOSTLY 70 TO 75 DEGREES WITH UPPER 60S POSSIBLE IN HEAVIEST RAINFALL AREAS. HIGH PW/S OF OVER 1.5 UP TO 2 INCHES AND WEAKER STEERING CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL OF 2 PLUS INCHES FOR LATER SHIFTS TO MONITOR AND POSSIBLY 3+ INCHES WITH TRAINING OF STORMS AND POSSIBLE T-BONE OF WARM ADVECTION WING OF STORMS AHEAD OF A MAIN BOWING LINE. IF WE GET GOOD LATE PM HEATING THEN CONCERN REMAINS OF A DECENT AREA OF STRONG WINDS WITH A BOWING SEGMENT AS MENTIONED ABOVE EARLIER DUE TO HIGH/EXTREME INSTABILITY. HEAT INDICES IN SOUTHERN SECTIONS MAY PUSH UPPER 90S TO AROUND 100 DEGREES SUNDAY AFTERNOON. SUNDAY NIGHT AND MONDAY...HAVE LOW CHANCE POPS ATTM...POOR CONFIDENCE HERE DUE TO EVIDENCE OF WARM FRONT TO PUSH NORTH AND ENOUGH UPPER SUPPORT FOR ANOTHER MCS THAT SOLUTIONS OFTEN POORLY CAPTURE. LATER SHIFTS MAY NEED TO AGAIN UP POPS AND ADJUST HI TEMPERATURES DOWN AS THE CASE THE PREVIOUS 3 DAYS. MONDAY NIGHT THROUGH FRIDAY...AREA TO REMAIN ON THE EDGE OF OUR NORMAL MID SUMMER "RING OF FIRE" WITH STRONG UPPER LEVEL RIDING. KEPT MOSTLY DRY BUT A LOW RISK OF CONVECTION REMAINS THAT MAY PROPAGATE OR FIRE FOR LATER SHIFTS TO RECONSIDER. MODERATE TO HIGH INSTABILITY CONTINUE TO SUPPORT A SEVERE STORM POTENTIAL WITH ANY STORMS WITH AGAIN STRONG STRAIGHT LINE WINDS DUE TO HIGH INSTABILITY. HI TEMPERATURES MOSTLY 90 TO 95 DEGREES WITH SOME UPPER 90S POSSIBLE IN SOUTH AND LOWS MOSTLY 70 TO 75 DEGREES AND AFTERNOON HEAT INDICES 95 TO 100 DEGREES SUGGESTED FOR A FEW TO SEVERAL HOURS. EVIDENCE OF A BREAK IN THE HEAT TO DEVELOP BY THE FOLLOWING WEEKEND. NICHOLS && .AVIATION... /ISSUED 1228 PM CDT FRI JUN 29 2012/ OUTFLOW BOUNDARIES FROM TSRA SHOULD ARRIVE AT KBRL SHORTLY WITH GUSTY WINDS. OTHER THAN CHANGEABLE WINDS VFR WX SHOULD BE SEEN THROUGH 00Z/30. MORE TSRA ARE EXPECTED TO DVLP IN CENTRAL IOWA AND MOVE EAST TO ILLINOIS 21Z/29 TO 03Z/30 CAUSING MVFR CONDITIONS. POTENTIAL FOR BRIEF IFR CONDITIONS WITH A SEVERE TSRA. VFR CONDITIONS ARE EXPECTED TO CONTINUE AFT 00Z/30 WITH ANOTHER ROUND OF TSRA...POSSIBLY SEVERE...AFT 06Z/30. ..08.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR DES MOINES-HENRY IA- JEFFERSON-KEOKUK-LEE-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON. IL...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR HANCOCK-HENDERSON- MCDONOUGH-MERCER-WARREN. MO...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR CLARK-SCOTLAND. && $$ 08/NICHOLS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
610 PM EDT FRI JUN 29 2012 .MESOSCALE CONVECTIVE UPDATE... ISSUED AT 610 PM EDT FRI JUN 29 2012 UPDATED THE GRIDS AND ZONES TO REFLECT THE SEVERE AND STRONG STORMS THAT LOOK TO GRAZE OUR NORTHEAST COUNTIES OVER THE NEXT FEW HOURS. THESE WILL MOVE INTO A EXTREMELY UNSTABLE AIR MASS IN PLACE THROUGH OUR NORTHEAST CWA WITH A LARGE GUST FRONT BRINGING A STRONG POTENTIAL FOR DAMAGING WINDS GIVEN THEIR HISTORY TO THE NORTH. HAVE ADDED THESE ATTRIBUTES TO THE PERTINENT GRIDS AND ZONES. ALSO BUILT UP THE WIND GUSTS IN THE NORTHEAST AND KICKED DOWN TEMPS WITH THE LIKELY RAIN/GUST FRONT. UPDATES HAVE BEEN SENT. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 315 PM EDT FRI JUN 29 2012 THE HEAT WAVE WILL CONTINUE THROUGH THE WEEKEND WITH HIGH PRESSURE STAYING IN PLACE. THE MAIN FORECAST ISSUES ARE TO TRY AND FORECAST THE SHORT WAVES MOVING AROUND THE PERIPHERY OF THE UPPER HIGH AND TRY AND DETERMINE IF THEY WILL BE STRONG ENOUGH TO INITIATE CONVECTION. THE HRRR WAS SHOWING A MCS TYPE OF SYSTEM BARELY EFFECTING THE AREA NORTH OF THE MOUNTAIN PARKWAY. CONSIDERING THE SEVERE THUNDERSTORM WATCH IS JUST NORTH OF THE FORECAST AREA...THOUGHT IT WOULD BE WISE TO INCLUDE SOME THUNDER IN THE FORECAST. IT IS THE SAME SITUATION FOR TOMORROW...WITH ANOTHER WAVE MOVING ACROSS THE AREA. THE HEAT IS PRETTY MUCH A SLAM DUNK. WE BROKE THE THE ALL TIME RECORD FOR JACKSON AT 102 TODAY AND IT MIGHT EVEN GO UP IN THE NEXT HOUR. WILL HAVE TO WAIT AND SEE. LONDON ALSO HIT 102 TIED THE ALL TIME RECORD FOR THE YEAR. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 315 PM EDT FRI JUN 29 2012 THE EXTENDED FORECAST PERIOD CONTINUES TO FEATURE AND BROAD AND STRENGTHENING RIDGE OVER MUCH OF THE CONUS STRETCHING FROM THE FRONT RANGE OF THE ROCKIES AND EAST OVER THE NORTHERN TIER OF THE TN VALLEY AS WELL AS THE SOUTHEAST. THE MILLION DOLLAR QUESTION...OR THE FORECAST CHALLENGE OF THE EXTENDED IS...WITH A PROMINENT TROUGH OVER THE NEW ENGLAND AREA AND A SERIES OF RIDGE RUNNERS DIVING SOUTHEAST THROUGH THE WESTERN FRINGE OF THE GREAT LAKES AND INTO THE OHIO VALLEY...WILL AN MCS BE ABLE TO OVERCOME OUR DROUGHT AND MAKE IT A BIT FURTHER SOUTH INTO THE EASTERN KENTUCKY AREA. AT THIS POINT...THE MODELS HANDLE THE OVERALL LONG WAVE PATTERN QUITE WELL BUT JUDGING PREVIOUS RUNS COMPARED HOW THE PATTERN HAS PANNED OUT IN THE SYNOPTIC AND MESOSCALE...AREAS THAT WOULD HAVE RECEIVED RAIN ACCORDING TO THE PAST RUNS HAVE NOT COME TO PASS. THIS PROVIDES A LOWER CONFIDENCE THAT RAINFALL WILL OCCUR IN THE EXTENDED AND GIVEN THE FACT THAT A STRONG TO DECENT CAP WILL BE IN PLACE OVER MUCH OF THE AREA. DESPITE BOTH THE EURO AND GFS SHOWING CONVECTION UNDER THE CAP...WILL LEAN TOWARDS A DRIER FORECAST. WILL RUN THE ALL MODEL BLEND AND COORDINATE WITH NEIGHBORING OFFICES TO GO ON THE DRY SIDE OF THE RESULT. AFTER THE PRODUCING THE MODEL ALL BLEND AND COORDINATION WITH NEIGHBORING FORECAST OFFICES...DECIDED TO GO WITH A DRY EXTENDED FORECAST. THE LACK OF CONFIDENCE IN MODELS PRODUCING QPF IN THE EXTENDED UNDER THE CAP AND THE WORSENING DROUGHT CONDITIONS AIDED IN THIS DECISION. BETTER INTERROGATION WILL BE NEEDED IN LATER RUNS IF EASTERN KENTUCKY IS TO GET MEASURABLE RAIN BUT SOME BETTER SUPPORT ARRIVES THROUGH THE OHIO VALLEY ON THU INTO THU NIGHT THAT MAY PUT DOWN SOME MUCH NEEDED RAIN BUT AT THIS POINT...FELT A DRY FORECAST WOULD BE A BETTER REPRESENTATION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 1031 AM EDT FRI JUN 29 2012 VFR WILL PREVAIL THROUGH THE PERIOD AS HIGH PRESSURE REMAINS IN CONTROL LOCALLY...WITH LIGHT WLY WINDS AROUND 5 KTS OR LESS. SOME ISOLATED THUNDERSTORMS MAY FORM NORTH OF THE MOUNTAIN PARKWAY THIS AFTERNOON. && .JKL WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL MIDNIGHT EDT SATURDAY NIGHT FOR KYZ044- 050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...GREIF SHORT TERM...JJ LONG TERM....SHALLENBERGER AVIATION...JJ
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
441 PM EDT FRI JUN 29 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS EVENING. WEAK HIGH PRESSURE WILL MOVE OVER THE AREA ON SATURDAY. ANOTHER COLD FRONT WILL PUSH THROUGH LATE SATURDAY NIGHT. WEAK LOW PRESSURE WILL KEEP SOMEWHAT UNSETTLED CONDITIONS OVER THE AREA EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... UPDATE...NOT MUCH CHANGE TO THE GOING FCST WITH THIS UPDATE. POP LOOKS GOOD FOR AREAS OF CURRENT CONVECTION. CONDS REMAIN FAVORABLE FOR AT LEAST SCT STRONG TSTMS ACROSS THE NRN AND ERN CWA. LARGE RESERVOIR OF DCAPE AOA 1000 J/KG AND STEEP LLVL LAPSE RATES WILL SUPPORT THE POTENTIAL FOR DMGG WINDS WITH ANY OF THE STRONGER CELLS. ALOFT...STEEP MID LVL LAPSE RATES ARE SUPPORTING PLENTIFUL CAPE IN THE -10 TO -30 C LAYER...AND LARGE HAIL WILL ALSO BE PSBL. WIND SHIFT HAS ENTERED THE CWA...WITH TSTMS FORMING ALONG IT. SO FAR THEY HAVE BEEN STRUGGLING TO MAINTAIN MUCH CONTINUITY...IN BOTH HGT AND STRENGTH. SOUNDING ANALYSIS SUGGESTS THAT SFC DEW POINTS ARE A COUPLE DEGREES TOO COOL TO OVERCOME THE VERY WARM AIR ALOFT...AND A SMALL CAP REMAINS. IT WOULD NOT TAKE MUCH DYNAMIC COOLING TO ERASE THAT REMAINING CAP...AND FOR THAT REASON WILL MAINTAIN THE SVR WORDING IN THE GRIDS. PRES FALLS WOULD SUPPORT THE GREATEST RISK RUNNING FROM THE WHITE MTNS TO THE MIDCOAST OVER THE NEXT COUPLE OF HRS. PREVIOUS DISCUSSION...A SHORT WAVE TROUGH JUST WEST OF MONTREAL CONTINUES TO MOVE SOUTHEASTWARD AS OF 1830Z AND WILL MOVE ACROSS OUR NORTHERN ZONES LATER THIS AFTERNOON AND EARLY EVENING. A COLD FRONT CONTINUES TO PROGRESS ACROSS VERMONT AND WILL CONTINUE MOVING EASTWARD. A MOIST AND UNSTABLE AIRMASS HAS DEVELOPED ACROSS THE REGION THIS AFTERNOON...AND IS COUPLED WITH MODERATE DEEP LAYER SHEAR. ISOLATED TO WIDELY SCT THUNDERSTORMS SHOULD DEVELOP ACROSS NRN VT OR NRN NH BY 20Z...THEN MOVE EASTWARD ACROSS THE WRN ME MOUNTAINS AND INTO CENTRAL MAINE BY 21-22Z. MORE ISOLATED DEVELOPMENT IS POSSIBLE FURTHER SOUTH INTO SRN ME...BUT MUCH LESS CONFIDENCE EXISTS IN THAT POSSIBILITY AS THAT AREA WILL BE MORE REMOVED FROM THE SHORT WAVE FORCING. GIVEN THE KINEMATIC AND THERMODYNAMIC ENVIRONMENT...ANY STORMS THAT DO INDEED DEVELOP AND CAN SUSTAIN THEMSELVES WILL HAVE THE POTENTIAL TO DEVELOP INTO SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. A BRIEF TORNADO CANNOT BE RULED OUT IN CENTRAL MAINE WHERE LOW LEVEL WINDS WILL BE SLIGHTLY MORE BACKED. FLASH FLOOD GUIDANCE IS RELATIVELY LOW ACROSS CENTRAL ME DUE TO RECENT HEAVY RAINFALL. THEREFORE A FLASH FLOOD THREAT IS NON-ZERO DESPITE STORM MOTIONS LIKELY AROUND OR GREATER THAN 20 KT. ANY FLASH FLOOD THREAT WOULD BE ENHANCED BY TRAINING OF STORMS. ANY THUNDERSTORM ACTIVITY SHOULD QUICKLY MOVE OFF TO THE EAST OF THE CWA BY 00-01Z. THEREAFTER...FOR THE BALANCE OF THE NIGHT...MOSTLY CLEAR SKIES ARE EXPECTED. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... FAIR AND WARM WEATHER IS EXPECTED ON SATURDAY. ONLY CAVEAT IS ACROSS THE NORTHERNMOST ZONES WHERE LATE DAY OR EVENING SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ONCE AGAIN AS ANOTHER SHORT WAVE TROUGH SKIMS THE AREA ALONG WITH THE RR QUAD OF AN UPPER LEVEL JET STREAK. ISOLD STRONG STORM POSSIBLE THERE WITH STRONG DEEP LAYER SHEAR IN PLACE DESPITE LESSER INSTABILITY THAN TODAY. CLEARING THEN TAKES PLACE SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... LARGE SCALE PATTERN CONTINUES CYCLONIC FLOW ALOFT WHICH RESULTS IN THE THREAT OF CONVECTIVE SHOWERS AND THUNDERSTORMS WHICH BECOME ENHANCED WITH THE PASSAGE OF ANY SHORTWAVES. TIMING OF THESE SHORTWAVES IS VERY DIFFICULT THIS FAR IN ADVANCE. AS A RESULT WILL NOT GO ABOVE CHANCE POPS AT THIS TIME. LATEST MODEL RUNS ARE TRENDING TEMPS A LITTLE COOLER FOR SUNDAY..HAVE NUDGED THEM DOWN ABOUT 5 DEGREES OVER PREVIOUS FORECAST. IT LOOKS LIKE NEXT WEEKS TEMPERATURES WILL BE SEASONABLY WARM BUT NOT GETTING INTO THE EXTREME TEMPERATURES THAT MUCH OF THE EAST WILL SEE. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM...VFR CONDITIONS EXPECTED OUTSIDE OF ANY THUNDERSTORMS THROUGH THIS EVENING. THEREAFTER...SOME LOCAL FOG/MIST IS LIKELY AT NORMALLY PRONE TERMINALS. VFR FOR SATURDAY AND SATURDAY NIGHT. LONG TERM...MAINLY MVFR CONDITIONS WITH LOCALIZED IFR CONDITIONS IN ANY SCATTERED THUNDERSTORMS. && .MARINE... SHORT TERM...SCA FOR MID COAST OF MAINE OUTSIDE OF THE BAYS FOR TONIGHT FOR SEAS BUILDING TO AROUND 5 FT. LONG TERM...WINDS AND WAVES BELOW SCA LEVELS THIS PERIOD. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ150-152. && $$ LEGRO
AREA FORECAST DISCUSSION
NWS GRAY ME
251 PM EDT FRI JUN 29 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS EVENING. WEAK HIGH PRESSURE WILL MOVE OVER THE AREA ON SATURDAY. ANOTHER COLD FRONT WILL PUSH THROUGH LATE SATURDAY NIGHT. WEAK LOW PRESSURE WILL KEEP SOMEWHAT UNSETTLED CONDITIONS OVER THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... A SHORT WAVE TROUGH JUST WEST OF MONTREAL CONTINUES TO MOVE SOUTHEASTWARD AS OF 1830Z AND WILL MOVE ACROSS OUR NORTHERN ZONES LATER THIS AFTERNOON AND EARLY EVENING. A COLD FRONT CONTINUES TO PROGRESS ACROSS VERMONT AND WILL CONTINUE MOVING EASTWARD. A MOIST AND UNSTABLE AIRMASS HAS DEVELOPED ACROSS THE REGION THIS AFTERNOON...AND IS COUPLED WITH MODERATE DEEP LAYER SHEAR. ISOLATED TO WIDELY SCT THUNDERSTORMS SHOULD DEVELOP ACROSS NRN VT OR NRN NH BY 20Z...THEN MOVE EASTWARD ACROSS THE WRN ME MOUNTAINS AND INTO CENTRAL MAINE BY 21-22Z. MORE ISOLATED DEVELOPMENT IS POSSIBLE FURTHER SOUTH INTO SRN ME...BUT MUCH LESS CONFIDENCE EXISTS IN THAT POSSIBILITY AS THAT AREA WILL BE MORE REMOVED FROM THE SHORT WAVE FORCING. GIVEN THE KINEMATIC AND THERMODYNAMIC ENVIRONMENT...ANY STORMS THAT DO INDEED DEVELOP AND CAN SUSTAIN THEMSELVES WILL HAVE THE POTENTIAL TO DEVELOP INTO SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. A BRIEF TORNADO CANNOT BE RULED OUT IN CENTRAL MAINE WHERE LOW LEVEL WINDS WILL BE SLIGHTLY MORE BACKED. FLASH FLOOD GUIDANCE IS RELATIVELY LOW ACROSS CENTRAL ME DUE TO RECENT HEAVY RAINFALL. THEREFORE A FLASH FLOOD THREAT IS NON-ZERO DESPITE STORM MOTIONS LIKELY AROUND OR GREATER THAN 20 KT. ANY FLASH FLOOD THREAT WOULD BE ENHANCED BY TRAINING OF STORMS. ANY THUNDERSTORM ACTIVITY SHOULD QUICKLY MOVE OFF TO THE EAST OF THE CWA BY 00-01Z. THEREAFTER...FOR THE BALANCE OF THE NIGHT...MOSTLY CLEAR SKIES ARE EXPECTED. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... FAIR AND WARM WEATHER IS EXPECTED ON SATURDAY. ONLY CAVEAT IS ACROSS THE NORTHERNMOST ZONES WHERE LATE DAY OR EVENING SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ONCE AGAIN AS ANOTHER SHORT WAVE TROUGH SKIMS THE AREA ALONG WITH THE RR QUAD OF AN UPPER LEVEL JET STREAK. ISOLD STRONG STORM POSSIBLE THERE WITH STRONG DEEP LAYER SHEAR IN PLACE DESPITE LESSER INSTABILITY THAN TODAY. CLEARING THEN TAKES PLACE SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... LARGE SCALE PATTERN CONTINUES CYCLONIC FLOW ALOFT WHICH RESULTS IN THE THREAT OF CONVECTIVE SHOWERS AND THUNDERSTORMS WHICH BECOME ENHANCED WITH THE PASSAGE OF ANY SHORTWAVES. TIMING OF THESE SHORTWAVES IS VERY DIFFICULT THIS FAR IN ADVANCE. AS A RESULT WILL NOT GO ABOVE CHANCE POPS AT THIS TIME. LATEST MODEL RUNS ARE TRENDING TEMPS A LITTLE COOLER FOR SUNDAY..HAVE NUDGED THEM DOWN ABOUT 5 DEGREES OVER PREVIOUS FORECAST. IT LOOKS LIKE NEXT WEEKS TEMPERATURES WILL BE SEASONABLY WARM BUT NOT GETTING INTO THE EXTREME TEMPERATURES THAT MUCH OF THE EAST WILL SEE. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM...VFR CONDITIONS EXPECTED OUTSIDE OF ANY THUNDERSTORMS THROUGH THIS EVENING. THEREAFTER...SOME LOCAL FOG/MIST IS LIKELY AT NORMALLY PRONE TERMINALS. VFR FOR SATURDAY AND SATURDAY NIGHT. LONG TERM...MAINLY MVFR CONDITIONS WITH LOCALIZED IFR CONDITIONS IN ANY SCATTERED THUNDERSTORMS. && .MARINE... SHORT TERM...SCA FOR MID COAST OF MAINE OUTSIDE OF THE BAYS FOR TONIGHT FOR SEAS BUILDING TO AROUND 5 FT. LONG TERM...WINDS AND WAVES BELOW SCA LEVELS THIS PERIOD. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ150-152. && $$ NEAR TERM...EKSTER SHORT TERM...EKSTER LONG TERM...LULOFS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
125 PM EDT FRI JUN 29 2012 LATEST UPDATE...AVIATION... .SYNOPSIS... ISSUED AT 342 AM EDT FRI JUN 29 2012 HIGHS AROUND 90 OR HIGHER ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK. CHANCES FOR RAIN ARE LOW SO THE VERY DRY WEATHER WILL CONTINUE. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 342 AM EDT FRI JUN 29 2012 FORECAST CONCERNS DEAL MAINLY WITH LOW CHANCES OF PCPN FOR THE NEXT FEW DAYS. DIDN/T CHANGE THE FCST MUCH. THE WEAK COLD FRONT THAT PASSED THROUGH THE REGION YESTERDAY STRETCHES FROM NORTHERN OHIO WWD THROUGH NRN ILLINOIS. THIS BOUNDARY WILL LIKELY ACT AS A FOCUS FOR CONVECTION DEVELOPING OVER THE CENTRAL PLAINS EARLY THIS MORNING AS IT MOVES EWD. HRRR AND ECMWF SUGGEST THAT SOME OF THE PLAINS CONVECTION WILL MOVE ACROSS IOWA AND NRN ILLINOIS AROUND 12Z BEFORE MOVING JUST SOUTH OF THE CWA MID MORNING. WE ADDED A SLIGHT CHANCE FOR A FEW HOURS OVER THE FAR SW CWA TO ACCOUNT FOR THIS. THE FRONTAL BOUNDARY TO THE SOUTH IS PROGD TO REMAIN SOUTH OF THE CWA THROUGH EARLY SUNDAY BEFORE BEGINNING TO MOVE NORTHEASTWARD. THUS CHANCES FOR PCPN ARE SLIM UNTIL SUNDAY WHEN CHANCES IMPROVE A BIT. AN UPPER TROUGH WILL TRY TO MOVE SOUTH OVER NRN LWR SUNDAY AT THE SAME TIME THAT THE SFC BOUNDARY IS LIFTING NORTH. H8 TEMPS WILL BE SEVERAL DEGREES COOLER TODAY THAN FRIDAY. THUS WE/LL LIKELY SEE HIGHS AROUND 90 VS MID TO UPPER 90S ON FRIDAY. AS A RESULT WE WON/T HIT HEAT ADVISORY CRITERIA. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 AM EDT FRI JUN 29 2012 FOR THE MOST PART IT WILL BE HOT AND DRY. THERE IS A SYSTEM THAT MAY BRING SOME SHOWERS TO THE AREA TUESDAY INTO WEDNESDAY. THE PRIMARY ISSUE IS HOW HOT DOES IT GET? IS THE ECMWF MORE CORRECT THAN THE GFS IN TERMS OF THE UPPER AIR PATTERN? IF THE ECMWF IS CORRECT HIGHS WILL BE IN THE MID TO UPPER 90S MOST OF THIS COMING WEEK...WHILE IF THE GFS IS CORRECT IT WILL MORE LIKELY BE MID TO UPPER 80S. GIVEN THE RECENT POOR PERFORMANCE OF THE GFS FOR TEMPERATURES... THE 28TH 06Z MAV HAD 90F FOR GRR ON THURSDAY.... I WOULD HAVE TO SIDE WITH THE ECMWF MORE SO. AS FOR THE UPPER AIR PATTERN... BOTH MODELS SHOW THE OVERALL PATTERN NICELY AND SUGGEST LITTLE OVERALL CHANGE. THAT IS A LARGE NEARLY STATIONARY UPPER LEVEL HIGH CENTERED OVER THE CENTRAL CONUS AND TROUGHS ON BOTH THE WEST AND EAST COAST. THE PROBLEM COMES IN AS TO WERE THE POLAR JET WILL ACTUALLY BE? THE ECMWF HAS A MUCH FLATTER EASTERN TROUGH (KEEPS THE COOLER AIR WELL NORTH AND EAST OF SOUTHWEST MICHIGAN ALL WEEK) WHILE THE GFS HAS THIS FEATURE MUCH NEARER SOUTHWEST MICHIGAN. I AM FAVORING THE ECMWF AND IN SO DOING PUSHED OUR TEMPERATURE GRIDS IN THAT DIRECTION BUT ONLY BY A FEW DEGREES. AS FOR OUR SHOWERS IN THE TUESDAY/WEDNESDAY TIME FRAME THIS IS A SHORTWAVE TOPPING THE UPPER RIDGE. I WOULD LOOK FOR LIMITED CONVECTION AT BEST WITH THIS FEATURE AND MORE THAN LIKELY IT WOULD SPLIT AND MOST OF THE STORMS WILL GO SOUTH OF LOWER MICHIGAN OR OVER NORTHERN LOWER OR UPPER MICHIGAN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY) ISSUED AT 125 PM EDT FRI JUN 29 2012 EXPECTING MOSTLY VFR CEILINGS AND VISIBILITIES THROUGH 18Z SATURDAY. AN AREA OF THUNDERSTORMS SHOULD PASS SOUTH OF THE I-94 CORRIDOR TAF SITES THIS AFTERNOON. ADDED VCTS AND CB TO THE KAZO... KBTL AND KJXN TAFS FOR A COUPLE HOURS. ANOTHER ROUND OF CONVECTION IS POSSIBLE LATE TONIGHT AND EARLY SATURDAY. EXPECTING THESE TO BE DISSIPATING AS THEY PASS AND WENT WITH RAIN SHOWERS WITH NO THUNDER IN THE SOUTH. THE NORTHERN TAF SITES SHOULD REMAIN DRY THROUGHOUT WITH MID AND HIGH CLOUDS PREVALENT. && .MARINE... ISSUED AT 342 AM EDT FRI JUN 29 2012 RELATIVELY LIGHT WINDS WILL RESULT IN LOW WAVES TODAY. && .HYDROLOGY... ISSUED AT 342 AM EDT FRI JUN 29 2012 DRY WEATHER EXPECTED TODAY AND SATURDAY. A BETTER CHANCE OF STORMS EXISTS SUNDAY...BUT BASIN QPF WILL REMAIN QUITE LOW AND THE DRY CONDITIONS WILL PREVAIL. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...93 SHORT TERM...93 LONG TERM...WDM AVIATION...63 HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1240 PM CDT FRI JUN 29 2012 .SHORT TERM... ISSUED AT 250 AM CDT FRI JUN 29 2012 (TODAY AND TONIGHT) THE UNPRECEDENTED JUNE HEAT WAVE WILL CONTINUE. HAVE NOT DEVIATED MUCH FROM GOING HIGHS FOR TODAY WHICH ARE CLOSER TO THE WARMER NAM MOS TEMPERATURES WHICH HAVE BEEN VERIFYING BETTER RECENTLY THAN THE COOLER GFS VALUES. THE RAP IS SHOWING MIXING TO AROUND 800MB THIS AFTERNOON WITH SURFACE TEMPERATURES CLIMBING ABOVE +40C LIKE THEY DID ON THURSDAY AFTERNOON. DEWPOINTS HAVE RECOVERED SOME EARLY THIS MORNING...BUT DEEP MIXING THIS AFTERNOON SHOULD CAUSE THEM TO FALL OFF AGAIN TODAY. HAVE A SLIGHT CHANCE FOR THUNDERSTORMS LATE TONIGHT OVER A SMALL PART OF THE NORTHERN CWA. THERE WILL BE A WEAK SHORTWAVE MOVING ACROSS IOWA ALONG AN EXISTING FRONT THAT COULD CAUSE A FEW THUNDERSTORMS TO MOVE DOWN INTO NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS. THE DRY ATMOSPHERE WOULD SUPPORT FORWARD PROPAGATION WHICH WOULD TEND TO KEEP ANY COMPLEX OF THUNDERSTORMS MOVING EASTWARD WITH TIME. OTHERWISE...NAM MOS LOWS LOOK GOOD FOR TONIGHT. BRITT && .LONG TERM... ISSUED AT 250 AM CDT FRI JUN 29 2012 (SATURDAY THROUGH THURSDAY) HEAT ADVISORY WILL NOW BE EXTENDED THROUGH SUNDAY AS THERE WILL BE YET ANOTHER DAY WITH HEAT INDEX READINGS BETWEEN 100-105. WILL KEEP THE SLIGHT CHANCE FOR THUNDERSTORMS OVER NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS SATURDAY AND SATURDAY NIGHT AS A FRONT LINGERS OVER SOUTHERN IOWA INTO CENTRAL ILLINOIS. HOWEVER...THIS FRONT WILL MOVE BACK NORTH AS A WARM FRONT ON SUNDAY. MORE CLOUDS IN ADDITION TO THE SLIGHT CHANCE OF RAIN WILL LIKELY CAUSE THE AMBIENT TEMPERATURES TO BE SLIGHTLY LESS OVER NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS THAN WHAT THEY WHERE ON THURSDAY. HOWEVER...THERE WILL ALSO BE SLIGHTLY HIGHER DEWPOINTS BECAUSE OF MOISTURE POOLING WHICH WILL ONLY RAISE THE HEAT INDEX. FARTHER SOUTH...DEEP MIXING IN ADDITION...PLENTY OF SOLAR INSOLATION AND 850MB TEMPS IN THE 23-26 RANGE SUPPORT WIDESPREAD 100+ TEMPERATURES LIKE THE NAM MOS. NAM 2M TEMPS ARE IN THE 100-105F RANGE OVER MOST OF THE CWA TODAY THROUGH SUNDAY. MOST OF THE GUIDANCE ALSO INDICATES THERE SHOULD BE A SLOW CLIMB IN DEWPOINTS THROUGH THE WEEKEND. NEW GFS/ECMWF STILL LOOKS HOT AND DRY MOST OF NEXT WEEK AS UPPER HIGH OVER THE SOUTHERN ROCKIES BUILDS NORTHEAST INTO THE CENTRAL CONUS. 850MB TEMPS WILL REMAIN IN THE LOWER-MID 20S CELSIUS. BRITT && .AVIATION... ISSUED AT 1240 PM CDT FRI JUN 29 2012 DESPITE STALLED FRONTAL BOUNDARY TO OUR NORTH...THE FLATTENED SURFACE RIDGE WILL KEEP FORECAST AREA DRY. SO WINDS TO REMAIN FROM THE SOUTHWEST TO WEST THROUGH FORECAST PERIOD...WITH VFR CONDITIONS. SOUTHWEST TO WEST WINDS TO DIMINISH TOWARDS SUNSET...THEN PICKUP AGAIN NEAR 15KTS BY MID MORNING ON SATURDAY. SPECIFICS FOR KSTL...DESPITE STALLED FRONTAL BOUNDARY TO OUR NORTH ...THE FLATTENED SURFACE RIDGE WILL KEEP FORECAST AREA DRY. SO WINDS TO REMAIN FROM THE SOUTHWEST TO WEST THROUGH FORECAST PERIOD...WITH VFR CONDITIONS. SOUTHWEST TO WEST WINDS TO DIMINISH TOWARDS SUNSET...THEN PICKUP AGAIN NEAR 15KTS BY 15Z SATURDAY. BYRD && .FIRE WEATHER... ISSUED AT 250 AM CDT THU JUN 28 2012 NO CHANGE TO THINKING ABOUT A HEIGHTENED FIRE DANGER TODAY AS ONLY THE WIND STAYING BELOW 15 MPH WILL KEEP THE AREA FROM NEEDING A RED FLAG WARNING. MINIMUM RELATIVE HUMIDITY VALUES WILL BE AT OR BELOW 20 PERCENT OVER MUCH OF THE AREA AND FORECAST 10 HOUR DEAD FUELS WILL BE 5-6 PERCENT. EXPECT SIMILAR CONDITIONS OVER THE WEEKEND. WILL CONTINUE TO HIGHLIGHT IN THE FIRE WEATHER FORECAST... SPECIAL WEATHER STATEMENTS...AND HAZARDOUS WEATHER OUTLOOK. && .CLIMATE... ISSUED AT 330 AM CDT THU JUN 28 2012 RECORD HIGHS DATE ST. LOUIS COLUMBIA QUINCY ---------------------------------------------- JUNE 29 105(1952) 104(1901) 103(1934) JUNE 30 103(1931) 103(1901) 103(1931) JULY 01 105(1980) 110(1980) 104(1930) JULY 02 101(1933) 102(1901) 103(1934) JULY 03 101(1934) 104(1901) 104(1911) JULY 04 102(1990) 106(1901) 103(1936) JULY 05 102(1938) 105(1911) 104(1911) && .LSX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO- CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO- IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO- MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. IL...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR ADAMS IL-BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL- MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL- PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
337 PM EDT FRI JUN 29 2012 .SYNOPSIS... AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BECOME SUPPRESSED ACROSS THE TENNESSEE VALLEY THROUGH THE WEEKEND. THIS WILL ALLOW A WEAK FRONTAL BOUNDARY TO SETTLE ACROSS THE REGION. THIS BOUNDARY WILL COMBINE WITH WEAK DISTURBANCES IN A NORTHWEST FLOW ALOFT TO KEEP A THREAT OF SHOWERS AND THUNDERSTORMS. HOT AND HUMID WEATHER IS EXPECTED TO CONTINUE THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... MAIN FORECAST DILEMMA THIS AFTERNOON AND EVENING WILL BE THE MCS/DAMAGING WIND EVENT THAT IS ABOUT TO UNFOLD ACRS OUR AREA. SEVERE THUNDERSTORM WATCH NUMBER 436 HAS BEEN ISSUED FOR MOST OF THE AREA. THUNDERSTORM COMPLEX OVER NW OHIO AND NRN INDIANA IS EXPECTED TO RACE SE ACRS THE REGION THIS AFTERNOON AND EARLY EVENING PER HRRR MODEL. THESE STORMS WILL FEED INTO A VERY UNSTABLE AIRMASS WITH 18Z KILN SOUNDING SHOWING MLCAPE VALUES APPROACHING 3500 J/KG. MODERATE SHEAR IS ALSO OVER THE AREA. FOR DAMAGING WIND POTENTIAL...DCAPE IS APPROACHING 2000 J/KG AND DELTA THETA E IS OVER 40 C. NONETHELESS...FORECAST AREA MAY BE DEALING WITH A DERECHO WHICH WILL PRODUCE HIGH END WINDS ACROSS THE REGION WITH LOCAL HAIL STONES SIZES POTENTIALLY GREATER THAN 2 INCHES. HEAVY RAIN WILL BE POSSIBLE...BUT WITH FAST MOVING STORMS...FLOODING SHOULD BE MINIMAL. MODELS INDICATE THAT THE MCS SHOULD BE EXITING THE SE CWFA BY EARLY EVENING. IN THE WAKE OF THIS FEATURE...THERE WILL LIKELY BE A LULL IN CONVECTION DUE TO THE AREA BEING WORKED OVER. HAVE KEPT THE REMAINDER OF THE FORECAST DRY OVERNIGHT BEHIND THE MCS. EXCESSIVE HEAT WARNING WILL CONTINUE UNTIL 8 PM...ALBEIT ONCE RAIN COOLED AIR HITS...HEAT INDEX VALUES WILL DROP. WILL DECIDE HOW TO HANDLE THIS ONCE CONVECTION MOVES ACRS THE AREA. OVERNIGHT LOWS WILL BE IN THE LOWER TO MID 70S. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... UPR LVL PATTERN WILL NOT CHANGE THAT MUCH OVER THE WEEKEND AS CENTER OF UPR LVL HIGH REMAINS NEAR OR JUST SOUTH OF THE TN RIVER VALLEY. MEANWHILE...A WEAK FRONTAL BOUNDARY WILL OSCILLATE ACRS THE AREA. MODELS CONTINUE TO DEPICT EMBEDDED DISTURBANCES ROTATING SE THROUGH THIS FLOW FROM TIME TO TIME. TIMING OF DISTURBANCES WILL BE PROBLEMATIC AT BEST ATTM. HAVE KEPT CHANCE POPS IN THE FORECAST...FAVORING THE DIURNAL CYCLE. HEAT AND HUMIDITY WILL CONTINUE WITH SOME SLIGHT COOLING EXPECTED ON SUNDAY. HAVE EXTENDED THE EXCESSIVE HEAT WARNING FOR MONTGOMERY COUNTY AND PARTS OF SE INDIANA AND SRN OHIO AS VALUES WILL BE UP TO 107 (MONTGOMERY WILL BE UP TO 104 BUT THEY HAVE SPECIAL HEAT HEADLINE CRITERIA). HEAT ADVISORY WILL BE IN EFFECT FOR THE REMAINDER OF THE REGION. HEAT HEADLINES MAY BE NEEDED AGAIN SUNDAY FOR SRN SECTIONS BUT WILL JUST MENTION THIS IN THE HWO ATTM. HIGHS WILL RANGE FROM THE MID 90S TO LOWER 100S ON SATURDAY AND LOWER 90S TO NEAR 100 ON SUNDAY. && .LONG TERM /MONDAY THROUGH FRIDAY/... THE AREA WILL CONTINUE UNDER NORTHWESTERLY FLOW ALOFT ON THE NORTHERN EDGE OF UPPER LEVEL RIDGING THROUGH MID WEEK. INTERMITTENT DISTURBANCES EMBEDDED IN THE FLOW WILL BRING CHANCES FOR CONVECTION THROUGHOUT THE TIME PERIOD. HAVE ONLY FORECAST LOW END MENTIONABLE POPS DURING THE DAYTIME HOURS FOR THE EXTENDED PERIOD DUE TO TIMING UNCERTAINTIES. THESE POPS COULD BE INCREASED FAIRLY QUICKLY AS EACH PARTICULAR WAVE BECOMES MORE APPARENT. TEMPERATURES ALOFT WILL ONLY COOL BY A DEGREE OR TWO AS THE WEEK PROGRESSES. HAVE THEREFORE KEPT FORECAST HIGH TEMPERATURES WELL ABOVE NORMAL...GENERALLY IN THE MIDDLE 90S. OVERNIGHT LOWS WILL LIKELY REMAIN IN THE 70S THROUGHOUT THE EXTENDED PERIOD. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... THUNDERSTORM COMPLEX HAS DEVELOPED INTO NW INDIANA ALONG AND NORTH OF A QUASI-STATIONARY SFC FRONTAL BOUNDARY THAT IS ORIENTED W-E THRU THE I-70 CORRIDOR ACRS OHIO. UNCERTAINTY EXISTS REGARDING EXACT STORM EVOLUTION THIS AFTN. LEANING TOWARD LATEST HRRR SOLN WHICH HAS BEEN POINTING TO THIS DEVELOPMENT FOR SEVERAL RUNS... EXPECT THIS CONVECTION TO DROP ESE AND BUILD S INTO VERY UNSTABLE AIRMASS WHERE BLYR CAPES ARE EXPECTED TO BE AROUND 4000 J/KG. HAVE A PERIOD OF VCTS THIS AFTN AT ALL TAF SITES AND HAVE A TEMPO GROUP FOR THUNDERSTORMS WITH GUSTS TO 35KTS AT KDAY WHERE BEST THREAT EXISTS. EXPECT CLOUDS TO GIVE WAY TO CLEARING WITH THE PASSAGE OF THIS SYSTEM THIS EVENING. IN HUMID AIRMASS...FOG WILL BE POSSIBLE OVERNIGHT AND HAVE A MENTION OF MVFR VSBY REDUCTION AT KCVG/KLUK AND KILN. ON SATURDAY...BEST FOCUS FOR CONVECTION LOOKS TO BE NORTH OF THE TAF SITES. THEREFORE...HAVE LEFT THE TAFS DRY WITH VFR CONDITIONS EXPECTED AT THIS TIME. OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ026- 034-035-042>046-051>056-060-062>065-070>074-080-082. HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT SATURDAY FOR OHZ026-034-035-042>046-051>056-060-062>065-070>074-080- 082. EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SATURDAY FOR OHZ061- 077>079-081-088. KY...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SATURDAY FOR KYZ089>100. IN...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR INZ050- 058-059-066. HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT SATURDAY FOR INZ050-058-059-066. EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SATURDAY FOR INZ073>075- 080. && $$ SYNOPSIS...HICKMAN NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...LATTO AVIATION...AR
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
349 PM CDT FRI JUN 29 2012 .DISCUSSION.../ISSUED AT 349 PM CDT/ SCATTERED THUNDERSTORMS ARE POSSIBLE THROUGH EARLY EVENING MAINLY EAST OF THE JAMES RIVER AS UPPER LEVEL WAVE PIVOTS THROUGH THE REGION. HRRR OUTPUT SHOWS A DIURNAL TREND AND EXPECT POTENTIAL FOR CONVECTION TO WANE THROUGH THE EVENING HOURS. MILD AIRMASS REMAINS ACROSS THE AREA OVERNIGHT INTO THE WEEKEND AND DID NOT ALTER LOW TEMPERATURES TONIGHT OR HIGHS TOMORROW. NAM AND GFS DISAGREE ON TIMING OF WAVE TOMORROW...BUT WITH NAM NOT EVEN HANDLING CURRENT SITUATION AND TIMING WELL...SIDED CLOSER TO GFS AND ECMWF. STILL UNSURE WHETHER WAVE WILL INDUCE ANY CONVECTION...BUT IF IT DOES SO...BEST CHANCES APPEAR TO BE LATE INT HE DAY ACROSS CENTRAL SOUTH DAKOTA...PUSHING EAST THROUGH THE EVENING HOURS. ON SATURDAY NIGHT...THE WAVE WILL CONTINUE TO MOVE TO THE SOUTHEAST. WITH THE SURFACE BOUNDARY CLOSER TO I80 YET...THE BEST CHANCE OF CONVECTION LOOKS TO BE CONFINED TO SOUTH OF I90 AND IS MOST LIKELY THROUGH 06Z. THE WAVES SHOULD MOVE SOUTH SO ANY LINGERING THUNDERSTORMS WILL GRADUALLY EXIT THE AREA AFTER 06Z. WITH ALL OF THE MOISTURE...LOWS WILL REMAIN IN THE UPPER 60S TO LOWER 70S. ANOTHER WAVE IS FORECAST BY ALL MODELS TO MOVE ACROSS NORTHERN NEBRASKA AS THE SURFACE BOUNDARY SLOWLY MOVES NORTHWARD ON SUNDAY. IT REMAINS FAIRLY WARM ALOFT SO THERE IS A STRONG CAPPING INVERSION AS THE WAVE APPROACHES AND IT WILL BE TOUGH TO GET CONVECTION TO DEVELOP. HOWEVER...WITH A BOUNDARY AND UPPER WAVE...DID ADD A SLIGHT CHANCE OF THUNDERSTORMS FOR SUNDAY AFTERNOON AND EVENING SOUTH OF I90. SINCE CONVECTION LOOKS TO HOLD OFF UNTIL LATE AFTERNOON...SHOULD BE SUNNY TO PARTLY CLOUDY SKIES MOST OF THE DAY SO HIGHS SHOULD RISE INTO THE 90S EVERYWHERE BUT THE BUFFALO RIDGE WHICH WILL HOLD IN THE 80S. AFTER SUNDAY EVENING...THERE REALLY LOOKS LIKE NO ORGANIZED CHANCE FOR PRECIPTITATION AND A STRONG 500 MB RIDGE BUILDS OVER THE CENTRAL US FOR ALL OF NEXT WEEK. THIS CARRIES MOST UPPER WAVES OVER ND AND NORTHERN MN. WHILE IT IS NOT IMPOSSIBLE THAT A ROGUE STORM COULD FORM EITHER MONDAY NIGHT OR WEDNESDAY IN SW MN...THE CHANCE IS SO SMALL THAT HAVE GONE DRY FROM LATE SUNDAY NIGHT THROUGH FRIDAY. OTHERWISE...THE SURFACE WIND WILL VARY FROM EAST TO SOUTH-SOUTHEAST THROUGH THE PERIOD AT THE SURFACE WITH SW FLOW ABOVE 900 MB. THIS WILL CONTINUE TO BRING VERY WARM AND HUMID AIR INTO THE ENTIRE REGION. BASICALLY HAVE HIGHS FROM THE LOWER TO MID 90S ALONG AND EAST OF I29 TO AROUND 102 IN SOUTH CENTRAL SD. THERE IS CERTAINLY THE POTENTIAL THAT ONE OR TWO OF THESE DAYS COULD BE EVEN WARMER THAN FORECAST BUT THAT WILL BE DEPENDENT ON IF WIND DIRECTION CAN GO SOUTH OR SOUTHWEST FOR A PERIOD. THE OTHER CONCERN IS THE HUMIDITY. WITH A STRONG INVERSION...EXPECT THAT MOST PLACES WILL SEE DEW POINTS IN THE UPPER 60S TO MID 70S EACH DAY WITH THE HIGHEST DEW POINTS EAST OF THE JAMES RIVER. ONLY SOUTH CENTRAL SOUTH DAKOTA COULD SEE DEW POINTS FALL INTO THE LOWER 60S...OR EVEN LOWER...IF TEMPERATURES RISE WELL ABOVE 100 DEGREES. THE COMBINATION OF HEAT AND HUMIDITY WILL RESULT IN HEAT INDICES BETWEEN 100 AND 110 EACH AFTERNOON. WE ARE ALSO EXPECTING LOWS IN THE LOW TO MID 70S EACH DAY...AND A DAY OR TWO WITH LOWS NEAR 80 ARE ALSO NOT IMPOSSIBLE. THIS WILL LIKELY RESULT IN A PROLONGED PERIOD OF DANGEROUS HEAT NEXT WEEK. /SCHUMACHER && .AVIATION.../FOR THE 18Z TAF ISSUANCE/ VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD. CONVECTION ACROSS CENTRAL SOUTH DAKOTA WILL SHIFT EAST CREATING A CHANCE OF SHOWERS AND THUNDERSTORMS. BEST CHANCES FOR CONVECTION WILL BE NORTH OF INTERSTATE 90 ALONG THE HIGHWAY 14 CORRIDOR...THOUGH THE FOCUS SHOULD BE EAST OF THE JAMES RIVER VALLEY AFTER 18Z. VISIBILITIES MAY BRIEFLY FALL TO AROUND 5 SM WITHIN THE CORE OF THUNDERSTORMS...THOUGH CEILINGS SHOULD REMAIN VFR. CONVECTION SHOULD MAINLY BE EAST OF THE FORECAST AREA AFTER 00Z SATURDAY...WITH CLEARING SKIES AND LIGHT EASTERLY FLOW IN THE LOW LEVELS. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1234 PM CDT FRI JUN 29 2012 .SHORT TERM...TODAY THROUGH SUNDAY NIGHT 319 AM CDT FRI JUN 29 2012 MAIN FORECAST CONCERN IS PRECIPITATION CHANCES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED SUBTROPICAL RIDGING COVERING MUCH OF THE SOUTHERN U.S. WITH A RIDGE AXIS EXTENDING FROM EASTERN WYOMING INTO EASTERN ALBERTA. THE FORECAST AREA LIES IN WEST-NORTHWEST FLOW DOWNSTREAM OF THE RIDGE AXIS. PLENTY OF DRY AIR SEEN ON WATER VAPOR INDICATING SUBSIDENCE IN PLACE...LEADING TO THE QUIET OVERNIGHT THUS FAR. 00Z MPX AND GRB SOUNDINGS SHOWED THE DRY...SUBSIDENT AIR QUITE NICELY WITH PRECIPITABLE WATER VALUES AROUND 0.77 INCHES OR 85 PERCENT OF NORMAL. JUST TO OUR SOUTH...A STREAM OF MOISTURE CAN BE SEEN IN WATER VAPOR OVER SOUTHERN IOWA. BIG DIFFERENCE WHEN IT COMES TO PRECIPITABLE WATER IN THIS MOISTURE STREAM COMPARED TO MPX...WITH THE 00Z OAX AND DVN SOUNDINGS SHOWING VALUE AROUND 2 INCHES OR NEARLY 200 PERCENT OF NORMAL. THIS HIGH AMOUNT OF MOISTURE IS REFLECTED TOO AT THE SURFACE WITH DEWPOINTS BETWEEN 75-80F ALONG A LINE BETWEEN HASTINGS NEBRASKA AND PEORIA ILLINOIS. THE MORE TROPICAL MOISTURE IS SITTING JUST NORTH OF A STATIONARY FRONTAL BOUNDARY. ALONG THE FRONTAL BOUNDARY...VARIOUS CLUSTERS OF STORMS HAVE BEEN TRACKING ACROSS NEBRASKA THROUGH THE OVERNIGHT HOURS. THESE HAVE BEING AIDED BY 925-850MB MOISTURE TRANSPORT OVER WESTERN KANSAS. ONE OF THE CLUSTERS CROSSING CENTRAL NEBRASKA HAS AN MCV WITH IT. ANOTHER ZONE OF 850MB MOISTURE TRANSPORT IS NOTED OVER IOWA...GOING OVER TOP OF THE FRONT...PER VWP DATA. SO FAR NO CONVECTION HAS FIRED ON THE NOSE OF THIS TRANSPORT...THOUGH SOME 4000-6000 FT CLOUD BASES ARE PRESENT. FINALLY...TO THE WEST...A WEAK SHORTWAVE WAS NOTED OVER EASTERN MONTANA GOING THROUGH THE RIDGE AXIS...WITH SOME LIGHTNING ACCOMPANYING IT. TODAY AND TONIGHT...FORECAST IS A LITTLE DIFFICULT RIGHT OFF THE BAT WITH MOST MODELS STRUGGLING TO CAPTURE THE CONVECTION IN NEBRASKA. FIRST...IN GENERAL WITH THE UPPER FLOW...MODELS PROG THE RIDGE AXIS OVER THE NORTHERN ROCKIES TO SHIFT EAST INTO THE WESTERN DAKOTAS BY 12Z SATURDAY. THERE ARE ALSO SIGNALS FROM ALL MODELS THAT SOME FORM OF WEAK TROUGHING WILL BE OVER THE FORECAST AREA AT 12Z SATURDAY. THIS TROUGHING APPEARS TO FORM FROM A RESULT OF THE EASTERN MONTANA SHORTWAVE AND THE MCV MOVING THROUGH/BY THE AREA. MAIN QUESTION IS WILL ANY PRECIPITATION OCCUR AS THESE SHORTWAVES PASS BY OR MOVE THROUGH. ONGOING NEBRASKA CONVECTION SHOULD DIMINISH THIS MORNING AS IT ENTERS NORTHWEST MO/SOUTHWEST IOWA WITH THE WEAKENING OF THE LOW LEVEL JET. FOCUS FOR THIS MORNING IS ALSO ON THE ZONE OF 850MB MOISTURE TRANSPORT OVER IOWA. POTENTIAL DOES EXIST FOR CONVECTION TO FIRE ON THE NOSE OF IT BETWEEN 09-12Z OVER NORTHERN IOWA. ALSO... THERE APPEARS TO BE AN UPPER JET STREAK CROSSING I-90 THIS MORNING...WHICH IS CURRENTLY IN SOUTHWEST MINNESOTA. THIS WOULD GIVE A BRIEF UPPER DIVERGENCE SURGE. SHOULD CONVECTION GO...CAPE VALUES LIFTED FROM 850MB ARE NEAR 3000 J/KG WITH NO CIN AND 1-6 KM SHEAR NEAR 40 KT...SUGGESTING POTENTIAL FOR ORGANIZED SEVERE STORMS. THIS MOISTURE TRANSPORT BENDS MORE WEST AND NORTHWEST THROUGH THE MORNING...SUGGESTING ANY CONVECTION WOULD PROBABLY BE OVER WITH BY 15Z. ATTENTION THEN TURNS TO THE EASTERN MONTANA SHORTWAVE...LIKELY COMING AT THE AREA DURING THE AFTERNOON AND EVENING. IF CONVECTION DOES NOT FIRE EARLY THIS MORNING...CONVECTION COULD FIRE UP ALONG/SOUTH OF I-90 LATE THIS AFTERNOON AND EVENING WITH THIS SHORTWAVE. 0-6KM SHEAR FOR THE AFTERNOON/EVENING IS AROUND 30 KT...SUGGESTING MAYBE SOME ORGANIZED MULTI-CELL CONVECTION...WHICH COULD POSE AT MOST A RISK FOR DAMAGING WINDS. OVERALL..CONFIDENCE NOT THAT HIGH FOR SEVERE THIS AFTERNOON/EVENING. IN FACT...OVERALL CONFIDENCE ON THIS PRECIPITATION FORECAST IS LOW...REFLECTED BY THE 20-40 PERCENT PROBABILITIES. SATURDAY THROUGH SUNDAY NIGHT...PRECIPITATION FORECAST REMAINS TRICKY. MODELS ARE IN GOOD AGREEMENT THAT THE RIDGE AXIS WILL REMAIN OVER THE DAKOTAS...WITH SOME SUGGESTION OF MORE AMPLIFICATION TOWARDS SUNDAY NIGHT AS A MORE POTENT SHORTWAVE CROSSES THE NORTHERN ROCKIES. THE UPPER FLOW STAYS WEST-NORTHWESTERLY OVER THE FORECAST AREA...MEANING THAT THE SURFACE FRONTAL BOUNDARY WILL LIKELY HOVER AROUND I-80 IN IOWA. MODELS ARE PRODUCING A VARIETY OF SHORTWAVES THAT RIDE ALONG THE BOUNDARY...SOME WHICH MIGHT BE REAL AND OTHERS CONVECTIVELY INDUCED. GIVEN THE PLENTIFUL INSTABILITY AROUND THE BOUNDARY...ANY SHORTWAVE COULD BRIEFLY SURGE THIS INSTABILITY NORTH INTO SOUTHERN PORTIONS OF THE FORECAST AREA AND INITIATE CONVECTION. HOWEVER...THE BULK OF ANY CONVECTION SHOULD STAY SOUTH OF THE FORECAST AREA CLOSER TO THE INSTABILITY. ENOUGH CONFIDENCE EXISTS TO REMOVE PRECIPITATION CHANCES ON SATURDAY WITH ALL MODELS FOCUSING ANY 850MB MOISTURE TRANSPORT AND SURFACE FRONTAL CONVECTION SOUTH OF THE AREA. 20 PERCENT CHANCES EXIST ACROSS MUCH OF THE FORECAST AREA SATURDAY NIGHT AND SUNDAY WITH SUGGESTIONS THAT THE 850MB MOISTURE TRANSPORT SURGES BACK NORTH. SUNDAY NIGHT STILL LOOKS OKAY TO HAVE A DRY FORECAST WITH LITTLE OR NO MOISTURE TRANSPORT...OR SHORTWAVE SUGGESTED TO KICK OFF CONVECTION. TEMPERATURES...THROUGHOUT THE SHORT TERM...925MB AND 850MB READINGS DO NOT CHANGE A WHOLE LOT DAY TO DAY...RUNNING BETWEEN 22-26C AND 18-22C RESPECTIVELY AT 18Z. COOLEST 925MB AND 850MB TEMPS ARE SUGGESTED OVER CENTRAL WISCONSIN. GIVEN POTENTIAL TO SEE QUITE A FEW HOURS OF SUN EACH DAY...HIGHS SHOULD STAY FAIRLY CONSISTENT. SAME GOES FOR LOWS TOO WITH LITTLE ADVECTION EXPECTED. DEWPOINTS DO NOT SEEM TO GET HIGH ENOUGH SOUTH OF I-90 TO WARRANT ANY HEAT ADVISORY HAZARD. RIGHT NOW...ANTICIPATING MAX HEAT INDICES BETWEEN 90-95. .LONG TERM...MONDAY THROUGH THURSDAY NIGHT 319 AM CDT FRI JUN 29 2012 GENERAL THEME FROM THE 29.00Z ECMWF...CANADIAN...UKMET...GFS AND GFS ENSEMBLES...AS WELL AS THEIR PREVIOUS RUNS...IS TO SUGGEST THE SUBTROPICAL RIDGE BUILDING AND EXPANDING NORTHWARD. HOWEVER...THERE IS ONE HUGE DIFFERENCE...WHERE THE ECMWF RUNS ALLOW THE RIDGING TO BUILD UP INTO THE FORECAST AREA WHEREAS ALL OTHER MODELS HAVE SOME FORM OF TROUGHING INDICATED OVER THE GREAT LAKES. THIS CREATES HAVOC FOR BOTH TEMPERATURE AND PRECIPITATION FORECASTING. SHOULD THE ECMWF RUNS BE CORRECT...MUCH IF NOT ALL OF THE LONG TERM IS DRY AND HOT WITH HIGHS LIKELY EACH DAY FROM THE MID 90S TO LOW 100S BEGINNING TUESDAY. ON THE OTHER HAND...OTHER MODELS CAN HAVE A SERIES OF SHORTWAVES AND FRONTS DROPPING THROUGH A NORTHWEST FLOW...ONE OF WHICH IS PROMINENTLY DISPLAYED FOR TUESDAY. FOR NOW...PRETTY MUCH STAYED WITH A CONSENSUS BLEND UNTIL MODELS CAN BECOME IN BETTER AGREEMENT. THIS RESULTS IN PRETTY MUCH EVERY 12 HOUR PERIOD HAVING AROUND A 20 PERCENT CHANCE OF PRECIPITATION WITH HIGHS IN THE MID 80S TO LOWER 90S. WE DEFINITELY HAVE TO WATCH THE LONG TERM PERIOD FOR A HEAT WAVE...SEEING TOO SOME SUPPORT FROM THE CFS TO GO ALONG WITH THE ECMWF. && .AVIATION...THROUGH 18Z SATURDAY 1234 PM CDT FRI JUN 29 2012 FRONTAL BOUNDARY DRAPED ACROSS SOUTHERN IOWA...WITH WATER VAPOR DEPICTING A SHORTWAVE OVER EASTERN NEBRASKA/WESTERN IOWA. THIS SHORTWAVE LIKELY TO PRODUCE MORE CONVECTION AS IT MOVES EASTWARD...BUT EXPECT ALL OF IT TO REMAIN SOUTH OF THE TAF SITES. THE ONLY INFLUENCE FROM THIS WILL BE A VEIL OF HIGH CLOUDS. THUS VFR CONDITIONS EXPECTED THROUGH 18Z SATURDAY...ALONG WITH LIGHT WINDS. && .ARX WATCHES/WARNINGS/ADVISORIES... 650 AM CDT FRI JUN 29 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...RABERDING