Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/28/12


AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
629 PM PDT WED JUN 27 2012 .DISCUSSION...AS OF 6:25 PM PDT WEDNESDAY...TEMPERATURES WILL MODERATE THROUGH MUCH OF THE PERIOD. THE CHALLENGE SHORT TERM WILL BE WHEN DOES THE MARINE LAYER RE-DEVELOP. CLEAR SKIES PREVAIL ONCE AGAIN ACROSS THE BAY AREA. AS NOTED THIS MORNING...THE AIRMASS ALOFT WARMED CONSIDERABLE OVER THE PAST DAY OR SO. AS A RESULT...TEMPERATURES CONTINUE TO WARM ACROSS THE REGION. SIMILAR TO YESTERDAY...THE 24 HOUR CHANGE INDICATES A WARMING OF 3 TO AS MUCH AS 9 DEGREES THIS AFTERNOON. IN OTHER WORDS..MORE 80S HAVE BEEN RECORDED INLAND WITH A FEW LOW 90S SOUTHERN INTERIOR. SYNOPTICALLY SPEAKING...NOT MUCH CHANGE REGARDING THE LONGWAVE PATTERN. HIGH PRESSURE REMAINS ANCHORED OVER THE FOUR CORNERS REGION AND NORTHEAST INTO THE PLAINS. OFF THE WESTERN US...A GENERAL AREA OF UPPER LEVEL TROUGHINESS REMAINS WITH PASSING EMBEDDED LOWS/SHORTWAVES. SHORT TERM(TONIGHT-SATURDAY)... THE CHALLENGE OVER THE NEXT 12-24 HOURS WILL BE WHETHER OR NOT THE MARINE LAYER/STRATUS REDEVELOPS. THE LATEST MESOCALE MODELS ARE NOT SHEDDING MUCH LIGHT ON THE SITUATION AS THEY ARE SPLIT ONCE AGAIN. THE LOCAL WRF AND HRRR DO A SHOW A SLIGHT INCREASE IN BL RH BY 12Z TOMORROW BUT STILL VERY PATCHY AT BEST. THAT BEING SAID...TRIED TO MIRROR THIS MORNING/S VIS SATELLITE WITH A SLIGHT INCREASE IN COVERAGE. THEREFORE...WILL KEEP A SHALLOW MARINE LAYER FROM THE SAN MATEO COAST SOUTHWARD PAST BIG SUR. ANY CLOUDS THAT DO DEVELOP WILL LIKELY CLEAR BACK TO THE COAST TOMORROW AFTERNOON. THE OVERALL AIRMASS IS FORECAST TO INCREASE IN TEMPS AT 850 MB ONCE AGAIN FOR THURSDAY. THEREFORE...TEMPS WILL WARM AGAIN TOMORROW...ESPECIALLY AWAY FROM THE COAST. COAST REMAINS 60S AND 70S...INLAND 80S AND 90S. BY THURSDAY NIGHT/FRIDAY MORNING AN EMBEDDED H5 SHORTWAVE TROUGH IS FORECAST TO SLIDE OVERHEAD PROVIDING THE BEST CHANCE FOR RETURNING STRATUS. TO START OFF THE WEEKEND...A WEAK COLD FRONT IS FORECAST TO SLIDE THROUGH THE REGION WITH LITTLE FAN FARE SATURDAY. MODEL GUIDANCE CONTINUES TO KEEP ALL PRECIP NORTH OF THE CWA. CURRENT FORECAST WILL REFLECT A DRY SCENARIO FOR THE CWA. LONG TERM(SUNDAY-WEDNESDAY)... MUCH OF THE LONG TERM CAN BE DESCRIBED AS DRY WITH SEASONABLE TEMPERATURES. IN FACT...THE LATEST CPC 8-14 DAY OUTLOOK KEEPS MUCH OF THE CA COAST BELOW NORMAL TEMPS WITH NEAR NORMAL PRECIP(OR DRY). && .AVIATION...AS OF 4:45 PM PDT WEDNESDAY...LOWER HUMIDITIES HAVE HELPED KEEP SKIES MAINLY CLEAR TO CLEAR OVER THE REGION THIS AFTERNOON. VFR IS FORECAST FOR THE EVENING. WEAK SUBSIDENCE WILL PREVAIL TONIGHT AND THURSDAY. VICINITY OF KSFO...VFR. WEST WINDS GUSTING TO 25 KNOTS TIL 04Z. KSFO BRIDGE APPROACH...VFR. MONTEREY BAY AREA TERMINALS...VFR. && .MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...SF BAY UNTIL 9 PM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 9 PM && $$ PUBLIC FORECAST: MM AVIATION/MARINE: CANEPA
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
426 AM EDT TUE JUN 26 2012 .SYNOPSIS... A COLD FRONT WILL MOVE SOUTH THROUGH THE REGION TODAY...THEN STALL JUST TO THE SOUTH TONIGHT. HIGH PRESSURE WILL BUILD JUST NORTH OF THE REGION THROUGH WEDNESDAY. THE FORECAST ON WEDNESDAY WILL BE HIGHLY DEPENDENT ON THE EXACT PATH OF DEBBY. DRY HIGH PRESSURE WILL THEN DOMINATE THE FORECAST AREA BEGINNING THURSDAY THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... PRE-DAWN...DEBBY CREEPING EAST IN THE NE GULF OF MEXICO WHILE DEEP TROPICAL MOISTURE IS STRUNG OUT TO THE NE ACROSS ALL OF NE FLORIDA...SE GEORGIA AND RIGHT ALONG THE SOUTH CAROLINA COAST. THE PWAT ON THE SPECIAL 06Z KCHS SOUNDING LAST NIGHT WAS 2.2 INCHES WHILE THE RUC HAS HIGH VALUES TO THE S OF SAVANNAH. NOCTURNAL CONVERGENCE CAUSED TSTMS WITH TORRENTIAL TROPICAL RAINS TO ERUPT RIGHT AT HIGH TIDE ALONG THE BEACHES FROM EDISTO TO FOLLY AND JUST INLAND TO JAMES ISLAND PROMPTING A FLASH FLOOD WARNING OVERNIGHT WHICH HAS SINCE BEEN CANCELLED AS RAINS QUICKLY DIMINISHED BY 08Z. THICK AND STEADY TROPICAL RAINS PERSIST ALONG COASTAL MCINTOSH COUNTY IN GEORGIA WITH SPORADIC AREAS OF COASTAL RAINS TO THE NORTH. A COLD FRONT WAS DROPPING INTO THE PEE DEE REGION OF SOUTH CAROLINA AND THE EARLIER CONVECTION ALONG IT HAD GREATLY DIMINISHED OVERNIGHT. WATER VAPOR SATELLIT IMAGERY SHOWS THE VAST COMPLEXITY OF THE OVERALL SYNOPTIC SITUATION WITH A LOAD OF VERY DRY AIR BANKED TO THE W OVER N GEORGIA AND FAR UPSTATE SOUTH CAROLINA. TODAY...THE BAROCLINIC BOUNDARY THROUGH THE FORECAST AREA WILL BE DISPLACED SOUTH INTO THE PATH OF TS DEBBY BY THE ADVANCING DRIER AIR AND HIGH PRES TO THE N. A SERIES OF WAVES ALONG THE BOUNDARY WILL RIPPLE ACROSS SE GEORGIA INTO THE COASTAL WATERS BUT MODELS IN DECENT AGREEMENT ON THE BULK OF THE FLOODING RAINS REMAINING JUST S OF OUR FORECAST AREA. WE ARE GOING TO HAVE TO WATCH MCINTOSH COUNTY REAL CLOSE TODAY AS THE GFS NOSES UP 2.6 PWATS INTO THAT AREA THROUGH MID AFTERNOON. HIGHEST POPS CONTINUE TO BE ALONG COASTAL SOUTH CAROLINA AND AREAS TO THE S OF SAVANNAH. THE MOISTURE GRADIENT TODAY IS EXTREMELY SHARP AND WHILE FAR INLAND AREAS REMAIN DRY...SOME COASTAL LOCATIONS IN THE DEEP MOIST AXIS MAY CONTINUE TO SEE SOME DOWNPOURS...AT LEAST THIS MORNING. AS THE FRONT PRESSES THROUGH TODAY...WINDS WILL SHIFT NE AND LIKELY BECOME A BREEZY AT TIMES...EVEN INLAND AREAS N OF I-16 AND ALL OF SE SOUTH CAROLINA AS 25-30 KT GEOSTROPHIC FLOW AND TIGHTENING MOISTURE GRADIENTS COME INTO PLAY. TEMPS WILL BE IN THE 80S TODAY. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... DRIER AIR COMING DOWN FROM THE N IS EXPECTED TO DECREASE CLOUDS TONIGHT BUT WE CONTINUE TO HANG ONTO SOME RAIN CHANCES IN OUR FAR SOUTHERN GEORGIA ZONES AFTER MIDNIGHT CLOSER TO DEBBY AND THE DEEPEST MOISTURE. TEMPS WILL BE NOTICEABLY COOLER WITH LOWER DEW POINTS NORTHERN ZONES BORDERING THE MIDLANDS AND PEE DEE... EVENTUAL LOWS IN THE LOWER 60S IN THESE AREAS TO NEAR 70 AROUND DARIEN GEORGIA. WEDNESDAY...THERE WILL BE A SHARP GRADIENT OF PRECIP OVER SOUTHEAST GEORGIA BY LATE MORNING AS A COLD FRONT BECOMES STATIONARY JUST SOUTH OF THE FORECAST AREA. PRECIP WILL BE HIGHLY DEPENDENT ON THE TRACK OF SPEED OF TROPICAL STORM DEBBY THROUGH WEDNESDAY AFTERNOON. LATEST TRENDS SHOW DEBBY MAKING A VERY SLOW TRACK EAST OVER NORTHERN FLORIDA WHILE IT ENCOUNTERS THE STATIONARY FRONT...BEFORE ENTERING THE GULF STREAM AND MAKING A SHIFT NORTHEAST. AMPLE MOISTURE SHOULD REMAIN OVER OUR SOUTHEAST GEORGIA WEDNESDAY MORNING...WITH PWATS NEAR 1.0...BEFORE DRY HIGH PRESSURE ENCOMPASSES THE SOUTHEAST. HAVE THEREFORE MAINTAINED CHANCE POPS OVER COASTAL SOUTHEAST GEORGIA AND ADJACENT COASTAL WATERS BEFORE DRY AIR QUICKLY RUSHES OVER THE AREA. WE COULD SEE HEAVY RAIN OVER SOUTHEAST GEORGIA WHERE MOISTURE IS DEEP. PRECIP CHANCES WILL QUICKLY DECREASE THROUGH WEDNESDAY AFTERNOON BEFORE HAVING A DRY FORECAST BY WEDNESDAY NIGHT. OVERALL HIGH TEMPS WILL WILL REACH THE MID/UPPER 80S FOR MOST LOCATIONS AS CLOUD COVER DECREASES THROUGH THE AFTERNOON. OVERNIGHT LOWS WILL BE IN THE MID/UPPER 60S. THURSDAY AND FRIDAY...CONDITIONS LOOK DRY AS SFC HIGH PRESSURE FILTERS INTO THE REGION ALONG WITH AN EXPANDING MID LVL RIDGE TO OUR WEST. TEMPS WILL QUICKLY MODIFY EACH AFTERNOON AS LIGHT NORTHEAST FLOW BECOMES SOUTH/SOUTHWEST. EXPECT HIGH TEMPS TO REACH LOW 90S BY THURSDAY AFTERNOON AND CONTINUE TO WARM INTO THE MID 90S BY FRIDAY AFTERNOON. OVERNIGHT LOWS WILL BE IN THE LOW/MID 70S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... CONDITIONS APPEAR WARM AND DRY WITH SFC HIGH PRESSURE AND AN LARGE MID LVL RIDGE EXPANDING OVER THE SOUTHEAST THROUGH THIS WEEKEND. CONDITIONS WILL BECOME HOT AND HUMID OVER THE WEEKEND AS MID LVL RIDGING BECOMES CENTERED OVER THE SOUTHEAST WHILE DEWPTS INCREASE TO THE MID 70S. WE COULD SEE SOME OF THE WARMEST TEMPS SO FAR THIS SEASON...WITH HIGHS APPROACHING THE UPPER 90S AWAY FROM THE COAST. THESE TEMPS ALONG WITH MID 70 DEWPTS MAY RESULT IN HEAT ADVISORY CONDITIONS...WITH HEAT INDICES BETWEEN 105 TO 110 DEGREES EACH AFTERNOON. 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 A FEW DEGREES ABOVE CLIMATOLOGY EARLY NEXT WEEK...LOW TO MID 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 /08Z TUESDAY THROUGH SATURDAY/... VERY LITTLE CHANGE ON THE 06Z CYCLE. CHANCES OF RAIN AT TIMES THROUGH MIDDAY THEN IMPROVING CONDITIONS LIKELY THIS AFTERNOON WITH VFR CONDITIONS INTO THIS EVENING. GUSTY NE WINDS WILL FOLLOW A COLD FRONT THIS AFTERNOON AT BOTH TERMINALS. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE WEEKEND. && .MARINE... A STRONG SW LOW LEVEL JET HAS WINDS IN SOLID SCA RANGE FROM GRAYS REEF TO BUOY 41004 BUT THE LATEST OBSERVATIONS HAVE DIMINISHING WINDS GEORGIA WATERS. SEAS ARE CHAOTIC BUT ELEVATED 4-6 FT IN THE NEAR SHORE WATERS AND UP TO 9 FT AT BUOY 41004. STRONG NE SURGING WILL ENSUE IN THE WAKE OF THE COLD FRONT TODAY... ESPECIALLY N OF THE SAVANNAH RIVER. THE SURGE WILL TAKE A WHILE TO REACH GRAYS REEF LATER TODAY BUT SPEEDS LIKELY TO INCREASE IN THE NEAR SHORE LEGS GIVEN THE LATEST GUIDANCE. WE HAVE SMALL CRAFT ADVISORIES NOW ALL WATERS INTO THE FIRST HALF OF TONIGHT AND THIS INCLUDES THE CHARLESTON HARBOR TODAY. SEAS OF THE GEORGIA WATERS WILL REMAIN IN SCA RANGE ALL NIGHT AND ADVISORIES PERSISTS THERE. RIP CURRENTS...THE COMBINATION OF MODERATE TO STRONG ONSHORE WINDS...2-3 FOOT SWELLS AND TIDES RUNNING HIGH WILL ALLOW FOR A MODERATE RISK OF RIP CURRENTS AT AREA BEACHES TUESDAY. WEDNESDAY...WILL HAVE ONGOING SMALL CRAFT ADVISORY CONDITIONS OVER THE OUTER GEORGIA COASTAL WATERS FOR 6 FEET SEAS. PERIODS OF SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER GEORGIA WATERS BEFORE HIGH PRESSURE SHIFTS OVER THE WATERS WEDNESDAY AFTERNOON. EXPECT ALL WINDS/SEAS TO GRADUALLY IMPROVE THROUGH WEDNESDAY EVENING AND DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY WEDNESDAY NIGHT. 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. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ330. SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR AMZ350-352- 354. SMALL CRAFT ADVISORY UNTIL 11 PM EDT WEDNESDAY FOR AMZ374. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...DPB LONG TERM...DPB AVIATION... MARINE...DPB
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
203 AM EDT TUE JUN 26 2012 .PREV DISCUSSION... /ISSUED 935 PM EDT MON JUN 25 2012/ UPDATE... ISOLATED SHOWERS AND TSTMS IN NORTH GA BETWEEN RYY AND GVL AT THIS TIME WILL CONTINUE TO DISSIPATE BY 11 PM EDT. THE COLD FRONT WITH DRIER AIR HAS PENETRATED INTO EXTREME NORTH GA AND SHOULD MOVE TO SOUTH OF ATL BY SUNRISE. BEST CHANCE OF SHOWERS WILL REMAIN SOUTH OF A CSG-MCN-AGS LINE AS THE RAIN SHIELD FROM T.S. DEBBY ROTATES OVER NORTH FL AND SOUTH GA. HAVE ADJUSTED POP AND SKY GRIDS TO REFLECT THIS RATIONALE FOR THE REST OF TONIGHT INTO TUESDAY. 16 SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... .ONLY FRINGE EFFECTS EXPECTED OVER SOUTHEAST PORTIONS FROM DEBBY... LATEST SURFACE ANALYSIS SHOWS OUTER PORTION OF MAIN CIRCULATION CENTER OF DEBBY STRETCHING FROM ROUGHLY CSG TO VDI. THIS HAS RESULTED ON BEST PRESSURE AND WIND GRADIENT OVER THIS AREA WITH GUSTS IN EXCESS OF 20 KNOTS AT TIMES. TO THE NORTH...STILL SEEING STRONGER NORTHERLY INFLUENCE AS WEAK FRONTAL BOUNDARY SINKS SOUTH AND HIGH CONTINUES TO DRIFT SOUTH FROM THE OHIO VALLEY. AS FAR AS PRECIP...AREA OF MOISTURE SURFACE CONVERGENCE ALONG OUTER BANDS FROM DEBBY HAVE BEEN THE MAIN FOCUS FOR ACTIVITY BUT SOME DRY AIR INTRUSION AT THE MID LEVELS HAS CONTRIBUTED SIGNIFICANTLY TO A LACK OF COVERAGE AND STRENGTH OF ACTIVITY. LATEST RAP MIXED CAPE ANALYSIS SHOWS MEAGER VALUES OVER SOUTHERN PORTIONS OF THE AREA AND WILL BE DIFFICULT TO REALIZE EVEN ISOLATED ACTIVITY THIS EVENING. BETTER VALUES TO THE NORTH BUT DRY AIR SEEMS TO HAVE HAD AN IMPACT ON DEVELOPMENT THERE AS WELL. STILL HAVE CAPES OF 2500 J/KG SO NOT READY TO GIVE UP ON AREA YET AND WILL KEEP ISOLATED POPS FOR THE NORTH. LATEST TRACK GUIDANCE IN BETTER AGREEMENT ON DIRECTION WITH NORTHEAST FLORIDA AND EVENTUALLY OUT IN THE ATLANTIC THE MOST LIKELY BUT SIGNIFICANT DIFFERENCES IN HOW LONG THIS WILL TAKE WITH THE GFS MEANDERING OVER THE EASTERN GULF THROUGH FRIDAY. EFFECTS LARGELY THE SAME FOR THE AREA WITH MOST OF THE REGION ON THE DRY SUBSIDENCE SIDE OF THE STORM. COULD SEE SOME OUTER BANDS ENTER THE SOUTHERN CWA SO HAVE KEPT LOW END POPS IN THROUGH MID WEEK. DEESE LONG TERM /WEDNESDAY THROUGH MONDAY/... WITH THE NHC STILL KEEPING DEBBY IN THE GULF ON WEDNESDAY...HAVE KEPT CHANCE POPS ACROSS THE FAR SOUTHERN PORTION OF THE CWA. THIS MAY BE A LITTLE OVERDONE IF THE STORM DECIDES TO TAKE A FASTER TRACK...SIMILAR TO THE ECMWF. WITH THE STORM EXPECTED TO MOVE ON SHORE THURSDAY AND THE BULK OF THE PRECIP ON THE EASTERN SIDE...HAVE OPTED TO CONTINUE PREVIOUS FORECAST TREND AND END POPS RELATED TO DEBBY BY THURSDAY. BOTH 00Z ECMWF AND 06Z GFS WERE IN AGREEMENT ABOUT UPPER RIDGE PUSHING INTO CWA BY THE END OF THE WEEK THAT WOULD PROVIDE HOT MAX TEMPS ACROSS THE AREA. 12Z GFS HOWEVER IS SLOWER WITH DEBBY AND DOESNT START BUILDING THE RIDGE INTO THE AREA UNTIL THE END OF THE LONG TERM. AT THIS POINT HAVE OPTED TO KEEP MAX TEMPS IN THE MID 90S WITH A FEW POINTS IN THE UPPER 90S BUT IF DEBBY MOVES OUT AND RIDGE BUILDS IN...MAY HAVE TO INCREASE MAX TEMPS FOR THE END OF THE WEEK AND THE WEEKEND. 11 && .AVIATION... 06Z UPDATE... NO SIGNIFICANT AVIATION WX CONCERNS THROUGH 12Z WEDNESDAY. PRECIP ASSOCIATED WITH TS DEBBY WILL REMAIN SOUTH OF MAJOR AIRPORTS IN NORTH AND CENTRAL GA. HIGH CLOUD SHIELD IS ALREADY EAST OF I-85 AND WILL CONTINUE TO PUSH SLOWLY EAST. SHOULD SEE SOME MIDDAY CUMULUS DEVELOP AROUND 5000-6000FT BUT NOT MUCH AS DRY LOW LEVEL AIR PUSHES SOUTH TODAY AND TONIGHT. SFC WINDS WILL BECOME NE AND INCREASE TO 7-12KTS BY SUNRISE. GUSTS TO 18-23KTS ARE LIKELY TODAY WITH TIGHT PRESSURE GRADIENT AND VERTICAL MIXING IN PLACE. //ATL CONFIDENCE...06Z UPDATE... HIGH CONFIDENCE ON ALL ELEMENTS. SNELSON && .PRELIMINARY POINT TEMPS/POPS... ATHENS 89 60 92 64 / 10 10 10 10 ATLANTA 88 65 88 68 / 10 10 10 10 BLAIRSVILLE 85 56 86 59 / 10 0 10 5 CARTERSVILLE 90 58 91 63 / 10 5 10 5 COLUMBUS 93 69 92 71 / 20 10 10 10 GAINESVILLE 87 62 88 66 / 10 5 10 5 MACON 93 64 92 67 / 20 10 20 10 ROME 92 58 92 63 / 10 5 10 5 PEACHTREE CITY 90 59 88 64 / 10 10 10 10 VIDALIA 89 70 90 70 / 50 30 50 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SNELSON LONG TERM....20 AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1026 AM EDT TUE JUN 26 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 302 AM EDT TUE JUN 26 2012 HIGH PRESSURE AND AN EXPANDING RIDGE ALOFT WILL KEEP DRY WEATHER OVER CENTRAL INDIANA THROUGH LATE WEEK ALONG WITH NEAR RECORD TEMPERATURES BY THURSDAY AND FRIDAY. AS THE RIDGE FLATTENS OVER THE WEEKEND...A WEAK COLD FRONT WILL SLIP INTO THE REGION BRINGING LIMITED CHANCES FOR MUCH NEEDED RAINFALL. TEMPERATURES WILL REMAIN ABOVE NORMAL INTO EARLY NEXT WEEK WITH THE UPPER RIDGE EXPANDING BACK INTO THE OHIO VALLEY. && .NEAR TERM /TODAY/... ISSUED AT 302 AM EDT TUE JUN 26 2012 CLEAR SKIES WITH HIGH PRESSURE ACROSS THE LOWER GREAT LAKES EARLY THIS MORNING. TEMPERATURES RANGED FROM THE MID 50S OVER NORTHEAST COUNTIES INTO THE 60S ELSEWHERE AS OF 07Z. FOCUS FOR TODAY IS ON TEMPS AND MIN RH VALUES AND POTENTIAL IMPACTS FOR FIRE WEATHER. EXPANSIVE SURFACE HIGH WILL DRIFT INTO CENTRAL INDIANA TODAY WITH A DRY E/NE FLOW ANTICIPATED FOR MUCH OF THE DAY. MODEL SOUNDINGS SHOW AN ABUNDANCE OF DRY AIR OVER THE REGION WHICH WILL MAKE FOR A CLOUDLESS DAY. FIRE DANGER WILL BE ENHANCED ONCE AGAIN TODAY WITH RH VALUES DIPPING TO NEAR 20-25% THIS AFTERNOON... BUT THE OVERALL THREAT APPEARS TO BE LOWER THAN WHAT WAS EXPERIENCED MONDAY AFTERNOON AND EVENING. EXTREMELY DRY AIR NOTED ON SOUNDINGS MONDAY AFTERNOON FROM THE BOUNDARY LAYER UP TO ABOUT 700MB WAS A LIKELY CULPRIT IN MIN RH VALUES DOWN BELOW 20% BEING OBSERVED AS IT WAS MIXED TO THE SURFACE. BOTH THE NAM AND RAP INDICATING MIXING HEIGHTS ARE LIKELY TO BE LOWER AND THAT RH VALUES WILL BE SOMEWHAT HIGHER IN THE BOUNDARY LAYER THIS AFTERNOON THAN VALUES NOTED FROM MONDAY. ALSO APPEARS WINDS WILL BE LOWER TODAY WITH SPEEDS CLOSER TO 10 TO PERHAPS 15MPH. WILL MENTION THE ENHANCED FIRE DANGER IN THE HWO PRIMARILY DUE TO EXPECTED LOW RH VALUES THIS AFTERNOON...BUT DO NOT BELIEVE HEADLINES ARE NECESSARY AT THIS POINT BASED ON THOUGHTS ABOVE. TEMPS...LAST DAY TO ENJOY PLEASANT TEMPS BEFORE THE FURNACE COMES TO THE OHIO VALLEY. RECENT TEMP PERFORMANCE WITH SUCH DRY CONDITIONS SUPPORTS RUNNING A FEW DEGREES ABOVE ALL MOS GUIDANCE FOR HIGHS. EXPECTING LOW TO MID 80S FROM EAST TO WEST OVER THE FORECAST AREA. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... ISSUED AT 302 AM EDT TUE JUN 26 2012 ...NEAR RECORD HIGH TEMPERATURES EXPECTED THURSDAY... FORECAST CHALLENGES REMAIN ON TEMPERATURES AS HEAT RIDGE CENTERED OVER THE CENTRAL PLAINS EXPANDS EAST AND BRINGS VERY HOT WEATHER INTO CENTRAL INDIANA BY THURSDAY. SURFACE HIGH PRESSURE WILL MOVE THROUGH THE REGION TONIGHT AND PROVIDE THE BEST OPPORTUNITY AT AN IDEAL RADIATIONAL COOLING SETUP WITH WINDS DROPPING TO NEAR CALM UNDER CLEAR SKIES. WARM ADVECTION WILL COMMENCE TONIGHT THEN INCREASE ON WEDNESDAY AS THE CENTER OF THE HIGH MOVES INTO THE SOUTHERN APPALACHIANS TRIGGERING RETURN SOUTHWEST FLOW ACROSS THE OHIO VALLEY. UPPER LEVEL HEIGHTS WILL STEADILY INCREASE WITH THE EXPANSION OF THE UPPER RIDGE INTO THE REGION BEGINNING WEDNESDAY. MAY SEE SOME HIGH CLOUDS TRAVERSING THE RIDGE PERIPHERY AS IT EXPANDS EAST BUT ONCE AGAIN SHOULD BE A DAY FILLED WITH ABUNDANT SUNSHINE. MODEL CONSENSUS WITH THE EXCEPTION OF THE OP GFS REMAINS CONSISTENT IN BRINGING THE CORE OF THE HEAT RIDGE EAST INTO THE REGION FOR THURSDAY RESULTING IN THE HOTTEST JUNE WEATHER FOR CENTRAL INDIANA SINCE 1988. ALL SIGNS POINT TO EXCEPTIONALLY HOT TEMPERATURES AS 850MB TEMPS APPROACH 27-28C AND 925MB TEMPS OF 32-34C ARE PRESENT BY THE AFTERNOON. OP GFS AS HAS BEEN MENTIONED PREVIOUSLY CONTINUES TO BE A COOL OUTLIER COMPARED TO ALL OTHER GUIDANCE. THE MODEL CONTINUES TO ADVERTISE POOR MIXING HEIGHTS BELOW 2KFT WHICH LOOKS TO BE COMPLETELY UNREALISTIC. THE OP GFS IS ALSO SIGNIFICANTLY OVERDOING DEWPOINTS WITH MID TO UPPER 70S FOR THURSDAY AFTERNOON. IN A TYPICAL OHIO VALLEY SUMMER...THESE NUMBERS MIGHT NOT BE TERRIBLY FAR FETCHED. HOWEVER AS DROUGHT CONDITIONS HAVE WORSENED OVER THE REGION AIDED BY A PERSISTENT LACK OF DEEP LOW LEVEL MOISTURE FETCH FROM THE GULF OF MEXICO OVER THE LAST 4-6 WEEKS...SOME MODELS LED BY THE OP GFS ARE INCREASINGLY STRUGGLING WITH DEWPOINTS AND RH VALUES. HAVE LEANED MUCH CLOSER TO ECMWF AND GGEM WHICH KEEP DEWPOINTS IN THE UPPER 50S AND LOWER 60S ON THURSDAY AFTERNOON AND SEEM MUCH MORE REALISTIC CONSIDERING DRY AIRMASS ACROSS THE REGION. THE TEMPS AT 850/925MB MENTIONED ABOVE WITH EXPECTED MIXING LEVELS TO AROUND 4-5KFT...COMBINED WITH W/SW WINDS EMANATING FROM THE CENTRAL PLAINS WHERE VERY HOT AND DRY CONDITIONS ALREADY EXIST ARE STRONGLY SUPPORTIVE OF HIGH TEMPS AT OR EXCEEDING THE CENTURY MARK ON THURSDAY. MIXING 33-34C AIR FROM 925MB TO THE SURFACE DRY ADIABATICALLY PRODUCE GROUND TEMPS IN THE LOW 100S. HAVE THEREFORE BUMPED TEMPS UP A DEGREE OR TWO FROM PREVIOUS FORECAST WITH CONFIDENCE INCREASING...AND NOW HAVE TEMPS REACHING 100 ACROSS THE ENTIRE FORECAST AREA. POTENTIAL FOR TEMPS TO TOP OUT AT 102 OR 103 DEGREES OVER THE WABASH VALLEY. THE RECORD HIGH FOR INDIANAPOLIS ON THURSDAY IS 101 FROM 1934...AND THIS WILL BE THREATENED. HEAT INDICES SHOULD REMAIN FAIRLY CLOSE TO ACTUAL TEMPERATURES WITH LOWER DEWPOINTS. REGARDLESS WITH EXPECTED HEAT...HEADLINES MAY EVENTUALLY BE NEEDED FOR THURSDAY. ALSO WITH STRONGER SURFACE WINDS AND WARMER TEMPS BOTH WEDNESDAY AND THURSDAY AFTERNOONS...ENHANCED FIRE DANGER WILL REMAIN A CONCERN. TEMPS...DRY AIR PRESENT OVER THE REGION HAS BEEN MUCH EASIER TO HEAT UP IN RECENT WEEKS AS HAS BEEN NOTED BY OBSERVED HIGHS CONSISTENTLY TOPPING GUIDANCE. SEE NO REASON THIS CHANGES WEDNESDAY AND THURSDAY...AND WILL GO SEVERAL DEGREES ABOVE MAVMOS AND EVEN A TOUCH WARMER IN MOST CASES THAN THE METMOS. GENERALLY UNDERCUT OVERNIGHT TEMP GUIDANCE FROM MOS THROUGH THE PERIOD WITH LARGER DIURNAL SWINGS. GOOD CHANCE BOTH ON WEDNESDAY AND THURSDAY THAT SOME LOCATIONS SEE CLOSE TO A 40 DEGREE SPREAD FROM MORNING LOWS TO AFTERNOON HIGHS. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 302 AM EDT TUE JUN 26 2012 GFS ENSEMBLES INDICATE SOME SUPPRESSION OF THE HEAT RIDGE BACK INTO SOUTHERN PLAINS AND GULF COAST STATES LATE THIS WEEK AS UPPER TROUGHING PUSHES ACROSS SOUTHEAST CANADA. AFTER THAT...THERE ARE DIFFERENCES AMONG THE ENSEMBLES BY EARLY NEXT WEEK. SOME OF THE MEMBERS BUILD THE HEAT RIDGE BACK INTO THE OHIO VALLEY...WHILE OTHERS AMPLIFY THE TROUGH MOVING THROUGH SOUTHEAST CANADA INTO NEW ENGLAND...EFFECTIVELY KEEPING THE HEAT RIDGE BACK OVER SOUTHERN PLAINS. WILL KEEP SOME POPS IN THE FORECAST FOR FRIDAY AND SATURDAY... CONSIDERING THE UPPER TROUGH PASSING NORTHEAST OF THE GREAT LAKES AT THAT TIME. THE ENSEMBLES THAT KEEP SHARPER TROUGHING OVER NEW ENGLAND EARLY NEXT WEEK ALSO HINT AT A PRECIPITATION THREAT LOCALLY ON SUNDAY AND MONDAY AS WELL. FOR NOW...WILL KEEP SUNDAY AND MONDAY DRY AND KEEP AN EYE ON FUTURE TRENDS. 850MB TEMPERATURE ANOMALIES ARE STILL QUITE A BIT ABOVE NORMAL IN THIS PERIOD...BUT NOT AS EXTREME AS IN THE SHORT TERM. AS A RESULT...SURFACE TEMPERATURES PROBABLY WON/T BE AS HOT IN THE EXTENDED AS THEY WILL BE LATER THIS WEEK. && .AVIATION /DISCUSSION FOR THE 261500Z KIND TAF UPDATE/... ISSUED AT 1026 AM EDT TUE JUN 26 2012 MINOR TWEAKS MADE TO KIND TAF PER OBSERVATIONS. NO OTHER CHANGES NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOWS... NO SIGNIFICANT CLOUD COVER...UNRESTRICTED VISIBILITY...SURFACE WINDS BELOW 12 KTS EXPECTED AT THE TAF SITES THROUGH 270000Z. && .CLIMATE... RECORD HIGHS FOR KIND: JUNE 28 - 101 (1934) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) ALL TIME JUNE RECORD HIGH AT KIND - 102 (6/25/1988 AND 6/26/1954) && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....JAS AVIATION...JAS/JH CLIMATE...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
636 AM EDT TUE JUN 26 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 302 AM EDT TUE JUN 26 2012 HIGH PRESSURE AND AN EXPANDING RIDGE ALOFT WILL KEEP DRY WEATHER OVER CENTRAL INDIANA THROUGH LATE WEEK ALONG WITH NEAR RECORD TEMPERATURES BY THURSDAY AND FRIDAY. AS THE RIDGE FLATTENS OVER THE WEEKEND...A WEAK COLD FRONT WILL SLIP INTO THE REGION BRINGING LIMITED CHANCES FOR MUCH NEEDED RAINFALL. TEMPERATURES WILL REMAIN ABOVE NORMAL INTO EARLY NEXT WEEK WITH THE UPPER RIDGE EXPANDING BACK INTO THE OHIO VALLEY. && .NEAR TERM /TODAY/... ISSUED AT 302 AM EDT TUE JUN 26 2012 CLEAR SKIES WITH HIGH PRESSURE ACROSS THE LOWER GREAT LAKES EARLY THIS MORNING. TEMPERATURES RANGED FROM THE MID 50S OVER NORTHEAST COUNTIES INTO THE 60S ELSEWHERE AS OF 07Z. FOCUS FOR TODAY IS ON TEMPS AND MIN RH VALUES AND POTENTIAL IMPACTS FOR FIRE WEATHER. EXPANSIVE SURFACE HIGH WILL DRIFT INTO CENTRAL INDIANA TODAY WITH A DRY E/NE FLOW ANTICIPATED FOR MUCH OF THE DAY. MODEL SOUNDINGS SHOW AN ABUNDANCE OF DRY AIR OVER THE REGION WHICH WILL MAKE FOR A CLOUDLESS DAY. FIRE DANGER WILL BE ENHANCED ONCE AGAIN TODAY WITH RH VALUES DIPPING TO NEAR 20-25% THIS AFTERNOON... BUT THE OVERALL THREAT APPEARS TO BE LOWER THAN WHAT WAS EXPERIENCED MONDAY AFTERNOON AND EVENING. EXTREMELY DRY AIR NOTED ON SOUNDINGS MONDAY AFTERNOON FROM THE BOUNDARY LAYER UP TO ABOUT 700MB WAS A LIKELY CULPRIT IN MIN RH VALUES DOWN BELOW 20% BEING OBSERVED AS IT WAS MIXED TO THE SURFACE. BOTH THE NAM AND RAP INDICATING MIXING HEIGHTS ARE LIKELY TO BE LOWER AND THAT RH VALUES WILL BE SOMEWHAT HIGHER IN THE BOUNDARY LAYER THIS AFTERNOON THAN VALUES NOTED FROM MONDAY. ALSO APPEARS WINDS WILL BE LOWER TODAY WITH SPEEDS CLOSER TO 10 TO PERHAPS 15MPH. WILL MENTION THE ENHANCED FIRE DANGER IN THE HWO PRIMARILY DUE TO EXPECTED LOW RH VALUES THIS AFTERNOON...BUT DO NOT BELIEVE HEADLINES ARE NECESSARY AT THIS POINT BASED ON THOUGHTS ABOVE. TEMPS...LAST DAY TO ENJOY PLEASANT TEMPS BEFORE THE FURNACE COMES TO THE OHIO VALLEY. RECENT TEMP PERFORMANCE WITH SUCH DRY CONDITIONS SUPPORTS RUNNING A FEW DEGREES ABOVE ALL MOS GUIDANCE FOR HIGHS. EXPECTING LOW TO MID 80S FROM EAST TO WEST OVER THE FORECAST AREA. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... ISSUED AT 302 AM EDT TUE JUN 26 2012 ...NEAR RECORD HIGH TEMPERATURES EXPECTED THURSDAY... FORECAST CHALLENGES REMAIN ON TEMPERATURES AS HEAT RIDGE CENTERED OVER THE CENTRAL PLAINS EXPANDS EAST AND BRINGS VERY HOT WEATHER INTO CENTRAL INDIANA BY THURSDAY. SURFACE HIGH PRESSURE WILL MOVE THROUGH THE REGION TONIGHT AND PROVIDE THE BEST OPPORTUNITY AT AN IDEAL RADIATIONAL COOLING SETUP WITH WINDS DROPPING TO NEAR CALM UNDER CLEAR SKIES. WARM ADVECTION WILL COMMENCE TONIGHT THEN INCREASE ON WEDNESDAY AS THE CENTER OF THE HIGH MOVES INTO THE SOUTHERN APPALACHIANS TRIGGERING RETURN SOUTHWEST FLOW ACROSS THE OHIO VALLEY. UPPER LEVEL HEIGHTS WILL STEADILY INCREASE WITH THE EXPANSION OF THE UPPER RIDGE INTO THE REGION BEGINNING WEDNESDAY. MAY SEE SOME HIGH CLOUDS TRAVERSING THE RIDGE PERIPHERY AS IT EXPANDS EAST BUT ONCE AGAIN SHOULD BE A DAY FILLED WITH ABUNDANT SUNSHINE. MODEL CONSENSUS WITH THE EXCEPTION OF THE OP GFS REMAINS CONSISTENT IN BRINGING THE CORE OF THE HEAT RIDGE EAST INTO THE REGION FOR THURSDAY RESULTING IN THE HOTTEST JUNE WEATHER FOR CENTRAL INDIANA SINCE 1988. ALL SIGNS POINT TO EXCEPTIONALLY HOT TEMPERATURES AS 850MB TEMPS APPROACH 27-28C AND 925MB TEMPS OF 32-34C ARE PRESENT BY THE AFTERNOON. OP GFS AS HAS BEEN MENTIONED PREVIOUSLY CONTINUES TO BE A COOL OUTLIER COMPARED TO ALL OTHER GUIDANCE. THE MODEL CONTINUES TO ADVERTISE POOR MIXING HEIGHTS BELOW 2KFT WHICH LOOKS TO BE COMPLETELY UNREALISTIC. THE OP GFS IS ALSO SIGNIFICANTLY OVERDOING DEWPOINTS WITH MID TO UPPER 70S FOR THURSDAY AFTERNOON. IN A TYPICAL OHIO VALLEY SUMMER...THESE NUMBERS MIGHT NOT BE TERRIBLY FAR FETCHED. HOWEVER AS DROUGHT CONDITIONS HAVE WORSENED OVER THE REGION AIDED BY A PERSISTENT LACK OF DEEP LOW LEVEL MOISTURE FETCH FROM THE GULF OF MEXICO OVER THE LAST 4-6 WEEKS...SOME MODELS LED BY THE OP GFS ARE INCREASINGLY STRUGGLING WITH DEWPOINTS AND RH VALUES. HAVE LEANED MUCH CLOSER TO ECMWF AND GGEM WHICH KEEP DEWPOINTS IN THE UPPER 50S AND LOWER 60S ON THURSDAY AFTERNOON AND SEEM MUCH MORE REALISTIC CONSIDERING DRY AIRMASS ACROSS THE REGION. THE TEMPS AT 850/925MB MENTIONED ABOVE WITH EXPECTED MIXING LEVELS TO AROUND 4-5KFT...COMBINED WITH W/SW WINDS EMANATING FROM THE CENTRAL PLAINS WHERE VERY HOT AND DRY CONDITIONS ALREADY EXIST ARE STRONGLY SUPPORTIVE OF HIGH TEMPS AT OR EXCEEDING THE CENTURY MARK ON THURSDAY. MIXING 33-34C AIR FROM 925MB TO THE SURFACE DRY ADIABATICALLY PRODUCE GROUND TEMPS IN THE LOW 100S. HAVE THEREFORE BUMPED TEMPS UP A DEGREE OR TWO FROM PREVIOUS FORECAST WITH CONFIDENCE INCREASING...AND NOW HAVE TEMPS REACHING 100 ACROSS THE ENTIRE FORECAST AREA. POTENTIAL FOR TEMPS TO TOP OUT AT 102 OR 103 DEGREES OVER THE WABASH VALLEY. THE RECORD HIGH FOR INDIANAPOLIS ON THURSDAY IS 101 FROM 1934...AND THIS WILL BE THREATENED. HEAT INDICES SHOULD REMAIN FAIRLY CLOSE TO ACTUAL TEMPERATURES WITH LOWER DEWPOINTS. REGARDLESS WITH EXPECTED HEAT...HEADLINES MAY EVENTUALLY BE NEEDED FOR THURSDAY. ALSO WITH STRONGER SURFACE WINDS AND WARMER TEMPS BOTH WEDNESDAY AND THURSDAY AFTERNOONS...ENHANCED FIRE DANGER WILL REMAIN A CONCERN. TEMPS...DRY AIR PRESENT OVER THE REGION HAS BEEN MUCH EASIER TO HEAT UP IN RECENT WEEKS AS HAS BEEN NOTED BY OBSERVED HIGHS CONSISTENTLY TOPPING GUIDANCE. SEE NO REASON THIS CHANGES WEDNESDAY AND THURSDAY...AND WILL GO SEVERAL DEGREES ABOVE MAVMOS AND EVEN A TOUCH WARMER IN MOST CASES THAN THE METMOS. GENERALLY UNDERCUT OVERNIGHT TEMP GUIDANCE FROM MOS THROUGH THE PERIOD WITH LARGER DIURNAL SWINGS. GOOD CHANCE BOTH ON WEDNESDAY AND THURSDAY THAT SOME LOCATIONS SEE CLOSE TO A 40 DEGREE SPREAD FROM MORNING LOWS TO AFTERNOON HIGHS. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 302 AM EDT TUE JUN 26 2012 GFS ENSEMBLES INDICATE SOME SUPPRESSION OF THE HEAT RIDGE BACK INTO SOUTHERN PLAINS AND GULF COAST STATES LATE THIS WEEK AS UPPER TROUGHING PUSHES ACROSS SOUTHEAST CANADA. AFTER THAT...THERE ARE DIFFERENCES AMONG THE ENSEMBLES BY EARLY NEXT WEEK. SOME OF THE MEMBERS BUILD THE HEAT RIDGE BACK INTO THE OHIO VALLEY...WHILE OTHERS AMPLIFY THE TROUGH MOVING THROUGH SOUTHEAST CANADA INTO NEW ENGLAND...EFFECTIVELY KEEPING THE HEAT RIDGE BACK OVER SOUTHERN PLAINS. WILL KEEP SOME POPS IN THE FORECAST FOR FRIDAY AND SATURDAY... CONSIDERING THE UPPER TROUGH PASSING NORTHEAST OF THE GREAT LAKES AT THAT TIME. THE ENSEMBLES THAT KEEP SHARPER TROUGHING OVER NEW ENGLAND EARLY NEXT WEEK ALSO HINT AT A PRECIPITATION THREAT LOCALLY ON SUNDAY AND MONDAY AS WELL. FOR NOW...WILL KEEP SUNDAY AND MONDAY DRY AND KEEP AN EYE ON FUTURE TRENDS. 850MB TEMPERATURE ANOMALIES ARE STILL QUITE A BIT ABOVE NORMAL IN THIS PERIOD...BUT NOT AS EXTREME AS IN THE SHORT TERM. AS A RESULT...SURFACE TEMPERATURES PROBABLY WON/T BE AS HOT IN THE EXTENDED AS THEY WILL BE LATER THIS WEEK. && .AVIATION /DISCUSSION FOR THE 261200Z TAFS/... ISSUED AT 636 AM EDT TUE JUN 26 2012 NO SIGNIFICANT CLOUD COVER...UNRESTRICTED VISIBILITY...SURFACE WINDS BELOW 12 KTS EXPECTED AT THE TAF SITES THROUGH 270000Z. && .CLIMATE... RECORD HIGHS FOR KIND: JUNE 28 - 101 (1934) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) ALL TIME JUNE RECORD HIGH AT KIND - 102 (6/25/1988 AND 6/26/1954) && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....JAS AVIATION...JAS CLIMATE...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
431 AM EDT TUE JUN 26 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 302 AM EDT TUE JUN 26 2012 HIGH PRESSURE AND AN EXPANDING RIDGE ALOFT WILL KEEP DRY WEATHER OVER CENTRAL INDIANA THROUGH LATE WEEK ALONG WITH NEAR RECORD TEMPERATURES BY THURSDAY AND FRIDAY. AS THE RIDGE FLATTENS OVER THE WEEKEND...A WEAK COLD FRONT WILL SLIP INTO THE REGION BRINGING LIMITED CHANCES FOR MUCH NEEDED RAINFALL. TEMPERATURES WILL REMAIN ABOVE NORMAL INTO EARLY NEXT WEEK WITH THE UPPER RIDGE EXPANDING BACK INTO THE OHIO VALLEY. && .NEAR TERM /TODAY/... ISSUED AT 302 AM EDT TUE JUN 26 2012 CLEAR SKIES WITH HIGH PRESSURE ACROSS THE LOWER GREAT LAKES EARLY THIS MORNING. TEMPERATURES RANGED FROM THE MID 50S OVER NORTHEAST COUNTIES INTO THE 60S ELSEWHERE AS OF 07Z. FOCUS FOR TODAY IS ON TEMPS AND MIN RH VALUES AND POTENTIAL IMPACTS FOR FIRE WEATHER. EXPANSIVE SURFACE HIGH WILL DRIFT INTO CENTRAL INDIANA TODAY WITH A DRY E/NE FLOW ANTICIPATED FOR MUCH OF THE DAY. MODEL SOUNDINGS SHOW AN ABUNDANCE OF DRY AIR OVER THE REGION WHICH WILL MAKE FOR A CLOUDLESS DAY. FIRE DANGER WILL BE ENHANCED ONCE AGAIN TODAY WITH RH VALUES DIPPING TO NEAR 20-25% THIS AFTERNOON... BUT THE OVERALL THREAT APPEARS TO BE LOWER THAN WHAT WAS EXPERIENCED MONDAY AFTERNOON AND EVENING. EXTREMELY DRY AIR NOTED ON SOUNDINGS MONDAY AFTERNOON FROM THE BOUNDARY LAYER UP TO ABOUT 700MB WAS A LIKELY CULPRIT IN MIN RH VALUES DOWN BELOW 20% BEING OBSERVED AS IT WAS MIXED TO THE SURFACE. BOTH THE NAM AND RAP INDICATING MIXING HEIGHTS ARE LIKELY TO BE LOWER AND THAT RH VALUES WILL BE SOMEWHAT HIGHER IN THE BOUNDARY LAYER THIS AFTERNOON THAN VALUES NOTED FROM MONDAY. ALSO APPEARS WINDS WILL BE LOWER TODAY WITH SPEEDS CLOSER TO 10 TO PERHAPS 15MPH. WILL MENTION THE ENHANCED FIRE DANGER IN THE HWO PRIMARILY DUE TO EXPECTED LOW RH VALUES THIS AFTERNOON...BUT DO NOT BELIEVE HEADLINES ARE NECESSARY AT THIS POINT BASED ON THOUGHTS ABOVE. TEMPS...LAST DAY TO ENJOY PLEASANT TEMPS BEFORE THE FURNACE COMES TO THE OHIO VALLEY. RECENT TEMP PERFORMANCE WITH SUCH DRY CONDITIONS SUPPORTS RUNNING A FEW DEGREES ABOVE ALL MOS GUIDANCE FOR HIGHS. EXPECTING LOW TO MID 80S FROM EAST TO WEST OVER THE FORECAST AREA. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... ISSUED AT 302 AM EDT TUE JUN 26 2012 ...NEAR RECORD HIGH TEMPERATURES EXPECTED THURSDAY... FORECAST CHALLENGES REMAIN ON TEMPERATURES AS HEAT RIDGE CENTERED OVER THE CENTRAL PLAINS EXPANDS EAST AND BRINGS VERY HOT WEATHER INTO CENTRAL INDIANA BY THURSDAY. SURFACE HIGH PRESSURE WILL MOVE THROUGH THE REGION TONIGHT AND PROVIDE THE BEST OPPORTUNITY AT AN IDEAL RADIATIONAL COOLING SETUP WITH WINDS DROPPING TO NEAR CALM UNDER CLEAR SKIES. WARM ADVECTION WILL COMMENCE TONIGHT THEN INCREASE ON WEDNESDAY AS THE CENTER OF THE HIGH MOVES INTO THE SOUTHERN APPALACHIANS TRIGGERING RETURN SOUTHWEST FLOW ACROSS THE OHIO VALLEY. UPPER LEVEL HEIGHTS WILL STEADILY INCREASE WITH THE EXPANSION OF THE UPPER RIDGE INTO THE REGION BEGINNING WEDNESDAY. MAY SEE SOME HIGH CLOUDS TRAVERSING THE RIDGE PERIPHERY AS IT EXPANDS EAST BUT ONCE AGAIN SHOULD BE A DAY FILLED WITH ABUNDANT SUNSHINE. MODEL CONSENSUS WITH THE EXCEPTION OF THE OP GFS REMAINS CONSISTENT IN BRINGING THE CORE OF THE HEAT RIDGE EAST INTO THE REGION FOR THURSDAY RESULTING IN THE HOTTEST JUNE WEATHER FOR CENTRAL INDIANA SINCE 1988. ALL SIGNS POINT TO EXCEPTIONALLY HOT TEMPERATURES AS 850MB TEMPS APPROACH 27-28C AND 925MB TEMPS OF 32-34C ARE PRESENT BY THE AFTERNOON. OP GFS AS HAS BEEN MENTIONED PREVIOUSLY CONTINUES TO BE A COOL OUTLIER COMPARED TO ALL OTHER GUIDANCE. THE MODEL CONTINUES TO ADVERTISE POOR MIXING HEIGHTS BELOW 2KFT WHICH LOOKS TO BE COMPLETELY UNREALISTIC. THE OP GFS IS ALSO SIGNIFICANTLY OVERDOING DEWPOINTS WITH MID TO UPPER 70S FOR THURSDAY AFTERNOON. IN A TYPICAL OHIO VALLEY SUMMER...THESE NUMBERS MIGHT NOT BE TERRIBLY FAR FETCHED. HOWEVER AS DROUGHT CONDITIONS HAVE WORSENED OVER THE REGION AIDED BY A PERSISTENT LACK OF DEEP LOW LEVEL MOISTURE FETCH FROM THE GULF OF MEXICO OVER THE LAST 4-6 WEEKS...SOME MODELS LED BY THE OP GFS ARE INCREASINGLY STRUGGLING WITH DEWPOINTS AND RH VALUES. HAVE LEANED MUCH CLOSER TO ECMWF AND GGEM WHICH KEEP DEWPOINTS IN THE UPPER 50S AND LOWER 60S ON THURSDAY AFTERNOON AND SEEM MUCH MORE REALISTIC CONSIDERING DRY AIRMASS ACROSS THE REGION. THE TEMPS AT 850/925MB MENTIONED ABOVE WITH EXPECTED MIXING LEVELS TO AROUND 4-5KFT...COMBINED WITH W/SW WINDS EMANATING FROM THE CENTRAL PLAINS WHERE VERY HOT AND DRY CONDITIONS ALREADY EXIST ARE STRONGLY SUPPORTIVE OF HIGH TEMPS AT OR EXCEEDING THE CENTURY MARK ON THURSDAY. MIXING 33-34C AIR FROM 925MB TO THE SURFACE DRY ADIABATICALLY PRODUCE GROUND TEMPS IN THE LOW 100S. HAVE THEREFORE BUMPED TEMPS UP A DEGREE OR TWO FROM PREVIOUS FORECAST WITH CONFIDENCE INCREASING...AND NOW HAVE TEMPS REACHING 100 ACROSS THE ENTIRE FORECAST AREA. POTENTIAL FOR TEMPS TO TOP OUT AT 102 OR 103 DEGREES OVER THE WABASH VALLEY. THE RECORD HIGH FOR INDIANAPOLIS ON THURSDAY IS 101 FROM 1934...AND THIS WILL BE THREATENED. HEAT INDICES SHOULD REMAIN FAIRLY CLOSE TO ACTUAL TEMPERATURES WITH LOWER DEWPOINTS. REGARDLESS WITH EXPECTED HEAT...HEADLINES MAY EVENTUALLY BE NEEDED FOR THURSDAY. ALSO WITH STRONGER SURFACE WINDS AND WARMER TEMPS BOTH WEDNESDAY AND THURSDAY AFTERNOONS...ENHANCED FIRE DANGER WILL REMAIN A CONCERN. TEMPS...DRY AIR PRESENT OVER THE REGION HAS BEEN MUCH EASIER TO HEAT UP IN RECENT WEEKS AS HAS BEEN NOTED BY OBSERVED HIGHS CONSISTENTLY TOPPING GUIDANCE. SEE NO REASON THIS CHANGES WEDNESDAY AND THURSDAY...AND WILL GO SEVERAL DEGREES ABOVE MAVMOS AND EVEN A TOUCH WARMER IN MOST CASES THAN THE METMOS. GENERALLY UNDERCUT OVERNIGHT TEMP GUIDANCE FROM MOS THROUGH THE PERIOD WITH LARGER DIURNAL SWINGS. GOOD CHANCE BOTH ON WEDNESDAY AND THURSDAY THAT SOME LOCATIONS SEE CLOSE TO A 40 DEGREE SPREAD FROM MORNING LOWS TO AFTERNOON HIGHS. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 302 AM EDT TUE JUN 26 2012 GFS ENSEMBLES INDICATE SOME SUPPRESSION OF THE HEAT RIDGE BACK INTO SOUTHERN PLAINS AND GULF COAST STATES LATE THIS WEEK AS UPPER TROUGHING PUSHES ACROSS SOUTHEAST CANADA. AFTER THAT...THERE ARE DIFFERENCES AMONG THE ENSEMBLES BY EARLY NEXT WEEK. SOME OF THE MEMBERS BUILD THE HEAT RIDGE BACK INTO THE OHIO VALLEY...WHILE OTHERS AMPLIFY THE TROUGH MOVING THROUGH SOUTHEAST CANADA INTO NEW ENGLAND...EFFECTIVELY KEEPING THE HEAT RIDGE BACK OVER SOUTHERN PLAINS. WILL KEEP SOME POPS IN THE FORECAST FOR FRIDAY AND SATURDAY... CONSIDERING THE UPPER TROUGH PASSING NORTHEAST OF THE GREAT LAKES AT THAT TIME. THE ENSEMBLES THAT KEEP SHARPER TROUGHING OVER NEW ENGLAND EARLY NEXT WEEK ALSO HINT AT A PRECIPITATION THREAT LOCALLY ON SUNDAY AND MONDAY AS WELL. FOR NOW...WILL KEEP SUNDAY AND MONDAY DRY AND KEEP AN EYE ON FUTURE TRENDS. 850MB TEMPERATURE ANOMALIES ARE STILL QUITE A BIT ABOVE NORMAL IN THIS PERIOD...BUT NOT AS EXTREME AS IN THE SHORT TERM. AS A RESULT...SURFACE TEMPERATURES PROBABLY WON/T BE AS HOT IN THE EXTENDED AS THEY WILL BE LATER THIS WEEK. && .AVIATION /DISCUSSION FOR THE 260900Z KIND TAF UPDATE/... ISSUED AT 431 AM EDT TUE JUN 26 2012 WILL VEER THE WINDS ABOUT 30 DEGREES ON THE UPDATE BASED ON SURFACE STREAMLINE ANALYSIS. NO OTHER SIGNIFICANT CHANGES MADE. PREVIOUS DISCUSSION FOLLOWS. VFR CONDITIONS UNDER CLEAR SKIES AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. NORTH AND NORTHEAST FLOW HAS ALSO BROUGHT IN MUCH DRIER AIR WITH DEW POINTS IN THE 40S WHICH WILL PREVENT ANY VISIBILITY RESTRICTIONS OVERNIGHT. NORTH AND NORTHEAST WINDS WILL BECOME LIGHT TO CALM OVERNIGHT AND BECOME NORTHEAST AND EAST AFTER SUNRISE LESS THAN 10 KNOTS. && .CLIMATE... RECORD HIGHS FOR KIND: JUNE 28 - 101 (1934) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) ALL TIME JUNE RECORD HIGH AT KIND - 102 (6/25/1988 AND 6/26/1954) && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....JAS AVIATION...MK/JAS CLIMATE...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
302 AM EDT TUE JUN 26 2012 .UPDATE... THE SYNOPSIS...NEAR TERM...SHORT TERM...LONG TERM AND CLIMATE SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 302 AM EDT TUE JUN 26 2012 HIGH PRESSURE AND AN EXPANDING RIDGE ALOFT WILL KEEP DRY WEATHER OVER CENTRAL INDIANA THROUGH LATE WEEK ALONG WITH NEAR RECORD TEMPERATURES BY THURSDAY AND FRIDAY. AS THE RIDGE FLATTENS OVER THE WEEKEND...A WEAK COLD FRONT WILL SLIP INTO THE REGION BRINGING LIMITED CHANCES FOR MUCH NEEDED RAINFALL. TEMPERATURES WILL REMAIN ABOVE NORMAL INTO EARLY NEXT WEEK WITH THE UPPER RIDGE EXPANDING BACK INTO THE OHIO VALLEY. && .NEAR TERM /TODAY/... ISSUED AT 302 AM EDT TUE JUN 26 2012 CLEAR SKIES WITH HIGH PRESSURE ACROSS THE LOWER GREAT LAKES EARLY THIS MORNING. TEMPERATURES RANGED FROM THE MID 50S OVER NORTHEAST COUNTIES INTO THE 60S ELSEWHERE AS OF 07Z. FOCUS FOR TODAY IS ON TEMPS AND MIN RH VALUES AND POTENTIAL IMPACTS FOR FIRE WEATHER. EXPANSIVE SURFACE HIGH WILL DRIFT INTO CENTRAL INDIANA TODAY WITH A DRY E/NE FLOW ANTICIPATED FOR MUCH OF THE DAY. MODEL SOUNDINGS SHOW AN ABUNDANCE OF DRY AIR OVER THE REGION WHICH WILL MAKE FOR A CLOUDLESS DAY. FIRE DANGER WILL BE ENHANCED ONCE AGAIN TODAY WITH RH VALUES DIPPING TO NEAR 20-25% THIS AFTERNOON... BUT THE OVERALL THREAT APPEARS TO BE LOWER THAN WHAT WAS EXPERIENCED MONDAY AFTERNOON AND EVENING. EXTREMELY DRY AIR NOTED ON SOUNDINGS MONDAY AFTERNOON FROM THE BOUNDARY LAYER UP TO ABOUT 700MB WAS A LIKELY CULPRIT IN MIN RH VALUES DOWN BELOW 20% BEING OBSERVED AS IT WAS MIXED TO THE SURFACE. BOTH THE NAM AND RAP INDICATING MIXING HEIGHTS ARE LIKELY TO BE LOWER AND THAT RH VALUES WILL BE SOMEWHAT HIGHER IN THE BOUNDARY LAYER THIS AFTERNOON THAN VALUES NOTED FROM MONDAY. ALSO APPEARS WINDS WILL BE LOWER TODAY WITH SPEEDS CLOSER TO 10 TO PERHAPS 15MPH. WILL MENTION THE ENHANCED FIRE DANGER IN THE HWO PRIMARILY DUE TO EXPECTED LOW RH VALUES THIS AFTERNOON...BUT DO NOT BELIEVE HEADLINES ARE NECESSARY AT THIS POINT BASED ON THOUGHTS ABOVE. TEMPS...LAST DAY TO ENJOY PLEASANT TEMPS BEFORE THE FURNACE COMES TO THE OHIO VALLEY. RECENT TEMP PERFORMANCE WITH SUCH DRY CONDITIONS SUPPORTS RUNNING A FEW DEGREES ABOVE ALL MOS GUIDANCE FOR HIGHS. EXPECTING LOW TO MID 80S FROM EAST TO WEST OVER THE FORECAST AREA. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... ISSUED AT 302 AM EDT TUE JUN 26 2012 ...NEAR RECORD HIGH TEMPERATURES EXPECTED THURSDAY... FORECAST CHALLENGES REMAIN ON TEMPERATURES AS HEAT RIDGE CENTERED OVER THE CENTRAL PLAINS EXPANDS EAST AND BRINGS VERY HOT WEATHER INTO CENTRAL INDIANA BY THURSDAY. SURFACE HIGH PRESSURE WILL MOVE THROUGH THE REGION TONIGHT AND PROVIDE THE BEST OPPORTUNITY AT AN IDEAL RADIATIONAL COOLING SETUP WITH WINDS DROPPING TO NEAR CALM UNDER CLEAR SKIES. WARM ADVECTION WILL COMMENCE TONIGHT THEN INCREASE ON WEDNESDAY AS THE CENTER OF THE HIGH MOVES INTO THE SOUTHERN APPALACHIANS TRIGGERING RETURN SOUTHWEST FLOW ACROSS THE OHIO VALLEY. UPPER LEVEL HEIGHTS WILL STEADILY INCREASE WITH THE EXPANSION OF THE UPPER RIDGE INTO THE REGION BEGINNING WEDNESDAY. MAY SEE SOME HIGH CLOUDS TRAVERSING THE RIDGE PERIPHERY AS IT EXPANDS EAST BUT ONCE AGAIN SHOULD BE A DAY FILLED WITH ABUNDANT SUNSHINE. MODEL CONSENSUS WITH THE EXCEPTION OF THE OP GFS REMAINS CONSISTENT IN BRINGING THE CORE OF THE HEAT RIDGE EAST INTO THE REGION FOR THURSDAY RESULTING IN THE HOTTEST JUNE WEATHER FOR CENTRAL INDIANA SINCE 1988. ALL SIGNS POINT TO EXCEPTIONALLY HOT TEMPERATURES AS 850MB TEMPS APPROACH 27-28C AND 925MB TEMPS OF 32-34C ARE PRESENT BY THE AFTERNOON. OP GFS AS HAS BEEN MENTIONED PREVIOUSLY CONTINUES TO BE A COOL OUTLIER COMPARED TO ALL OTHER GUIDANCE. THE MODEL CONTINUES TO ADVERTISE POOR MIXING HEIGHTS BELOW 2KFT WHICH LOOKS TO BE COMPLETELY UNREALISTIC. THE OP GFS IS ALSO SIGNIFICANTLY OVERDOING DEWPOINTS WITH MID TO UPPER 70S FOR THURSDAY AFTERNOON. IN A TYPICAL OHIO VALLEY SUMMER...THESE NUMBERS MIGHT NOT BE TERRIBLY FAR FETCHED. HOWEVER AS DROUGHT CONDITIONS HAVE WORSENED OVER THE REGION AIDED BY A PERSISTENT LACK OF DEEP LOW LEVEL MOISTURE FETCH FROM THE GULF OF MEXICO OVER THE LAST 4-6 WEEKS...SOME MODELS LED BY THE OP GFS ARE INCREASINGLY STRUGGLING WITH DEWPOINTS AND RH VALUES. HAVE LEANED MUCH CLOSER TO ECMWF AND GGEM WHICH KEEP DEWPOINTS IN THE UPPER 50S AND LOWER 60S ON THURSDAY AFTERNOON AND SEEM MUCH MORE REALISTIC CONSIDERING DRY AIRMASS ACROSS THE REGION. THE TEMPS AT 850/925MB MENTIONED ABOVE WITH EXPECTED MIXING LEVELS TO AROUND 4-5KFT...COMBINED WITH W/SW WINDS EMANATING FROM THE CENTRAL PLAINS WHERE VERY HOT AND DRY CONDITIONS ALREADY EXIST ARE STRONGLY SUPPORTIVE OF HIGH TEMPS AT OR EXCEEDING THE CENTURY MARK ON THURSDAY. MIXING 33-34C AIR FROM 925MB TO THE SURFACE DRY ADIABATICALLY PRODUCE GROUND TEMPS IN THE LOW 100S. HAVE THEREFORE BUMPED TEMPS UP A DEGREE OR TWO FROM PREVIOUS FORECAST WITH CONFIDENCE INCREASING...AND NOW HAVE TEMPS REACHING 100 ACROSS THE ENTIRE FORECAST AREA. POTENTIAL FOR TEMPS TO TOP OUT AT 102 OR 103 DEGREES OVER THE WABASH VALLEY. THE RECORD HIGH FOR INDIANAPOLIS ON THURSDAY IS 101 FROM 1934...AND THIS WILL BE THREATENED. HEAT INDICES SHOULD REMAIN FAIRLY CLOSE TO ACTUAL TEMPERATURES WITH LOWER DEWPOINTS. REGARDLESS WITH EXPECTED HEAT...HEADLINES MAY EVENTUALLY BE NEEDED FOR THURSDAY. ALSO WITH STRONGER SURFACE WINDS AND WARMER TEMPS BOTH WEDNESDAY AND THURSDAY AFTERNOONS...ENHANCED FIRE DANGER WILL REMAIN A CONCERN. TEMPS...DRY AIR PRESENT OVER THE REGION HAS BEEN MUCH EASIER TO HEAT UP IN RECENT WEEKS AS HAS BEEN NOTED BY OBSERVED HIGHS CONSISTENTLY TOPPING GUIDANCE. SEE NO REASON THIS CHANGES WEDNESDAY AND THURSDAY...AND WILL GO SEVERAL DEGREES ABOVE MAVMOS AND EVEN A TOUCH WARMER IN MOST CASES THAN THE METMOS. GENERALLY UNDERCUT OVERNIGHT TEMP GUIDANCE FROM MOS THROUGH THE PERIOD WITH LARGER DIURNAL SWINGS. GOOD CHANCE BOTH ON WEDNESDAY AND THURSDAY THAT SOME LOCATIONS SEE CLOSE TO A 40 DEGREE SPREAD FROM MORNING LOWS TO AFTERNOON HIGHS. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 302 AM EDT TUE JUN 26 2012 GFS ENSEMBLES INDICATE SOME SUPPRESSION OF THE HEAT RIDGE BACK INTO SOUTHERN PLAINS AND GULF COAST STATES LATE THIS WEEK AS UPPER TROUGHING PUSHES ACROSS SOUTHEAST CANADA. AFTER THAT...THERE ARE DIFFERENCES AMONG THE ENSEMBLES BY EARLY NEXT WEEK. SOME OF THE MEMBERS BUILD THE HEAT RIDGE BACK INTO THE OHIO VALLEY...WHILE OTHERS AMPLIFY THE TROUGH MOVING THROUGH SOUTHEAST CANADA INTO NEW ENGLAND...EFFECTIVELY KEEPING THE HEAT RIDGE BACK OVER SOUTHERN PLAINS. WILL KEEP SOME POPS IN THE FORECAST FOR FRIDAY AND SATURDAY... CONSIDERING THE UPPER TROUGH PASSING NORTHEAST OF THE GREAT LAKES AT THAT TIME. THE ENSEMBLES THAT KEEP SHARPER TROUGHING OVER NEW ENGLAND EARLY NEXT WEEK ALSO HINT AT A PRECIPITATION THREAT LOCALLY ON SUNDAY AND MONDAY AS WELL. FOR NOW...WILL KEEP SUNDAY AND MONDAY DRY AND KEEP AN EYE ON FUTURE TRENDS. 850MB TEMPERATURE ANOMALIES ARE STILL QUITE A BIT ABOVE NORMAL IN THIS PERIOD...BUT NOT AS EXTREME AS IN THE SHORT TERM. AS A RESULT...SURFACE TEMPERATURES PROBABLY WON/T BE AS HOT IN THE EXTENDED AS THEY WILL BE LATER THIS WEEK. && .AVIATION /DISCUSSION FOR THE 260600Z TAFS/... ISSUED AT 1228 AM EDT TUE JUN 26 2012 VFR CONDITIONS UNDER CLEAR SKIES AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. NORTH AND NORTHEAST FLOW HAS ALSO BROUGHT IN MUCH DRIER AIR WITH DEW POINTS IN THE 40S WHICH WILL PREVENT ANY VISIBILITY RESTRICTIONS OVERNIGHT. NORTH AND NORTHEAST WINDS WILL BECOME LIGHT TO CALM OVERNIGHT AND BECOME NORTHEAST AND EAST AFTER SUNRISE LESS THAN 10 KNOTS. && .CLIMATE... RECORD HIGHS FOR KIND: JUNE 28 - 101 (1934) JUNE 29 - 100 (1934) JUNE 30 - 97 (1933) ALL TIME JUNE RECORD HIGH AT KIND - 102 (6/25/1988 AND 6/26/1954) && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....JAS AVIATION...MK CLIMATE...RYAN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
145 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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1125 AM MDT TUE JUN 26 2012 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND KMCK TERMINALS. GUSTY SOUTH TO SOUTHWEST WINDS WILL PERSIST THROUGH LATE THIS EVENING WITH TIGHT SURFACE GRADIENT IN PLACE OVER BOTH TERMINALS. LEE TROUGH BEGINS TO SHIFT TO THE EAST OVERNIGHT WITH A COLD FRONT DROPPING SOUTH INTO NORTHEAST COLORADO. THIS WILL RESULT IN LIGHTER WINDS AROUND 10KT AT BOTH TERMINALS AFTER 06Z. && .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...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. FIRE WEATHER WATCH FROM WEDNESDAY MORNING 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...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ252>254. FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR COZ252>254. NE...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR NEZ079>081. FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR NEZ079>081. HEAT ADVISORY UNTIL 10 PM CDT THURSDAY FOR NEZ080-081. && $$ SHORT TERM...DR LONG TERM...AP AVIATION...DR FIRE WEATHER...DR CLIMATE...AP
AREA FORECAST DISCUSSION
NWS GOODLAND KS
128 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...(FRIDAY THROUGH MONDAY) ISSUED AT 226 AM MDT TUE JUN 26 2012 ELONGATED HIGH OVER THE SOUTHERN HALF OF THE CONUS WILL SOMEWHAT BISECT AS STRONG UPPER LEVEL TROUGH BEGINS TO MOVE INTO THE HUDSON BAY REGION BRINGING A COLD FRONT THROUGH THE REGION. MAIN RIDGE AXIS WILL STRENGTHEN OVER THE DESERT SOUTHWEST AND BEGIN TO BUILD BACK OVER THE ROCKIE MOUNTAINS BY THE WEEKEND. THIS WILL ALLOW FOR A FEW SHORTWAVE TROUGHS TO MOVE THROUGH THE FLOW AND INCREASING CHANCES TO PRECIPITATION AT THE END OF THE WEEK. AT THE SURFACE...SURFACE FRONT WILL REMAIN STALLED ACROSS NORTHERN KANSAS WITH INSTABILITY AXIS ALONG AND NORTH OF FRONTAL BOUNDARY. BEST CHANCE FOR PRECIPITATION WILL REMAIN ALONG AND NORTH OF THIS SURFACE BOUNDARY WITH BEST UPPER LEVEL SUPPORT RESIDING NORTH OF THE AREA. TEMPERATURES WILL CONTINUE TO REMAIN WELL ABOVE NORMAL AS 700MB TEMPERATURES ARE STILL PROGGED TO BE IN THE 15 TO 17C RANGE THROUGH SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1125 AM MDT TUE JUN 26 2012 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND KMCK TERMINALS. GUSTY SOUTH TO SOUTHWEST WINDS WILL PERSIST THROUGH LATE THIS EVENING WITH TIGHT SURFACE GRADIENT IN PLACE OVER BOTH TERMINALS. LEE TROUGH BEGINS TO SHIFT TO THE EAST OVERNIGHT WITH A COLD FRONT DROPPING SOUTH INTO NORTHEAST COLORADO. THIS WILL RESULT IN LIGHTER WINDS AROUND 10KT AT BOTH TERMINALS AFTER 06Z. && .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 226 AM 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 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...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. FIRE WEATHER WATCH FROM WEDNESDAY MORNING 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...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ252>254. FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR COZ252>254. NE...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR NEZ079>081. FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR NEZ079>081. HEAT ADVISORY UNTIL 10 PM CDT THURSDAY FOR NEZ080-081. && $$ SHORT TERM...DR LONG TERM...PM AVIATION...DR FIRE WEATHER...DR CLIMATE...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1128 PM MDT MON JUN 25 2012 .UPDATE... ISSUED AT 855 PM MDT MON JUN 25 2012 FIRE WEATHER PRODUCTS UPDATED. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 115 PM MDT MON JUN 25 2012 WV IMAGERY AND LATEST RUC H5 ANALYSIS SHOW VERY LARGE RIDGE OF HIGH PRESSURE ACROSS THE CENTRAL US IN WHAT APPEARS TO BE AN OMEGA BLOCK TYPE PATTERN...WITH UPPER LOWS OFF EACH COAST OF THE US. TROPICAL STORM DEBBIE REMAINS CENTERED JUST OFF THE COAST OF THE FLORIDA PANHANDLE AND WILL REMAIN TO FAR SOUTH AND EAST TO INFLUENCE OUR PATTERN OVER THIS PART OF THE CONUS. THE RIDGE AXIS EXTENDS AS FAR NORTH AS NORTHERN SASKATCHEWAN CANADA...WITH ITS CENTER OVER KANSAS. AT THE SURFACE A WARM FRONT HAS LINGERING OVER THE TRI-STATE AREA WITH TEMPERATURES 10 TO 15F WARMER SOUTH OF THE FRONT. RECORD TEMPERATURES ARE EXPECTED TO CONTINUE AS THIS STRONG RIDGE COMBINES WITH A DEEPENING LEE TROUGH OVER EASTERN COLORADO TO KEEP HOT AIRMASS IN PLACE. H85 TEMPS ON TUESDAY ARE PROGGED TO BE AS MUCH AS 3C WARMER THAN TODAY...UNDER A VERY SIMILAR SET UP AS THIS PAST SUNDAY WHEN SEVERAL LOCATIONS TIED ALL TIME RECORDS FOR JUNE. CONSIDERING THE FACT THAT THE SURFACE WARM FRONT WILL BE WELL NORTH OF THE AREA...WHICH WASNT THE CASE ON SUNDAY...TEMPERATURES MAY BE EVEN HOTTER. ALL TIME RECORD HIGHS FOR ANY MONTH COULD BE SET WITH MANY LOCATIONS AROUND 110...POSSIBLY 115. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 200 PM MDT MON JUN 25 2012 MAIN WEATHER STORY WILL REMAIN ON THE HEAT. ELONGATED UPPER RIDGE EXTENDS ACROSS THE CENTRAL PLAINS INTO THE SOUTHWEST STATES WEDNESDAY...SHIFTING SLIGHTLY SOUTH THURSDAY AS A FRONT TRIES TO MOVE INTO THE NORTHERN PART OF THE AREA. FLAT RIDGE FRIDAY BEGINS BECOMES A BIT MORE AMPLIFIED OVER THE WEEKEND INTO MONDAY WITH A WEAK RIDGE IN PLACE. 850MB TEMPERATURES SUPPORT AFTERNOON HIGHS CONTINUING IN THE 100-115 DEGREE RANGE (COOLEST IN FAR EASTERN COLORADO AND HOTTEST IN THE HILL CITY AREA). HOWEVER...A SLIGHT EASTERLY COMPONENT TO THE SOUTHERLY WIND (NOT TERRIBLY FAVORABLE FOR STRONG WARMING) MAY NEGATE FULL 850MB MIXING THUS WENT AS HIGH AS 105 IN THE HILL CITY AREA...MID 90S TO LOW 100S ELSEWHERE. RECORDS LIKELY TO BE BROKEN. DID MENTION SOME ISOLATED THUNDERSTORMS LATE WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AS SOME BETTER MOISTURE INTERACTS WITH A FRONTAL BOUNDARY...MAINLY ACROSS THE NORTHWEST 1/3 OF THE AREA. 700MB TEMPERATURES HOWEVER MAY BE TOO HOT FOR ANYTHING TO POP OR PRECIP TO REACH THE GROUND SHOULD THUNDERSTORMS DEVELOP. NEXT CHANCE LOOKS TO BE THURSDAY THROUGH SATURDAY WITH THE FRONT LINGERING ABOUT THE AREA. SUNDAY AND MONDAY LOOK DRY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1124 PM MDT MON JUN 25 2012 MAIN AVIATION CONCERN WILL BE THE POTENTIAL FOR FOG/STRATUS AT KMCK OVERNIGHT AND EARLY TUESDAY MORNING. STRATUS DEVELOPED RAPIDLY THIS EVENING IN CENTRAL NEBRASKA...BUT SO FAR HAS SHOWN NO SIGNS OF MOVING TOWARDS KMCK. HOWEVER...DEW POINT DEPRESSIONS ARE DROPPING AND FOG WILL LIKELY START TO FORM IN A FEW HOURS. HAVE LOWERED VISIBILITY TO 1SM BASED PRIMARILY ON THE LAST COUPLE OF NIGHTS WITH A SIMILAR SITUATION. FOG WILL BURN OFF SHORTLY AFTER SUNRISE. OTHERWISE...WITH STRONG RIDGE IN PLACE AND SUBSIDENCE EXPECT VFR CONDITIONS AT KGLD AND AT KMCK AFTER THE FOG DISSIPATES. && .FIRE WEATHER... ISSUED AT 855 PM MDT MON JUN 25 2012 HOT AND WINDY CONDITIONS WILL RESUME ON TUESDAY. AT LEAST TWO FIRE PLUMES WERE IDENTIFIABLE ON KGLD RADAR EARLIER TODAY...ONE IN THOMAS COUNTY AND ANOTHER IN DUNDY COUNTY...NOT TO MENTION THE FIRE THAT MOVED THROUGH LAST CHANCE COLORADO MONDAY AFTERNOON. SO OBVIOUSLY FUELS ARE THERE AND WITH LITTLE CHANGE ON TUESDAY RED FLAG CONDITIONS WILL AGAIN BE MET. && .CLIMATE... ISSUED AT 200 PM MDT MON JUN 25 2012 TUESDAY... 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 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...RED FLAG WARNING FROM 11 AM MDT /NOON CDT/ TO 9 PM MDT /10 PM CDT/ TUESDAY FOR KSZ001>004-013>016-027>029-041-042. HEAT ADVISORY UNTIL 10 PM CDT WEDNESDAY FOR KSZ002>004-014>016- 028-029-042. CO...RED FLAG WARNING FROM 11 AM TO 9 PM MDT TUESDAY FOR COZ252>254. NE...RED FLAG WARNING FROM 11 AM MDT /NOON CDT/ TO 9 PM MDT /10 PM CDT/ TUESDAY FOR NEZ079>081. HEAT ADVISORY UNTIL 10 PM CDT WEDNESDAY FOR NEZ080-081. && $$ UPDATE...024 SHORT TERM...DR LONG TERM...007 AVIATION...024 FIRE WEATHER...024 CLIMATE...007
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1040 PM EDT WED JUN 27 2012 .SYNOPSIS... LOW PRESSURE WILL SLOWLY MOVE NORTHEAST OVERNIGHT THROUGH THURSDAY. A COLD FRONT WILL CROSS THE REGION FRIDAY. && .NEAR TERM /THROUGH THURSDAY/... UPDATE...DECIDED ON PATCH FOG FOR THE OVERNIGHT. TWEAKED TEMPERATURES AND BROUGHT PRECIP CHCS UP TO CURRENT CONDITIONS AND THEN TRENDED THINGS IN LINE W/THE HRR AND RUC SHOWING WRAP AROUND SHOWERS PULLING BACK INTO NORTHERN AND EASTERN SECTIONS OVERNIGHT. SEE MARINE SECTION. PREVIOUS DISCUSSION... 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 /03Z THURSDAY 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: DROPPED THE SCA AS SEAS ARE DROPPING BELOW 6 FT AND ARE EXPECTED TO CONTINUE THIS WAY OVERNIGHT. THE SWAN GUIDANCE PICKED UP ON THE SURGE OF HIGHER SEAS WHICH LOOKED BE A SWELL W/8-9 SECOND PERIOD. SHORT TERM: NO HEADLINES EXPECTED. && .HYDROLOGY... UPDATE...MOIDIFIED MATM1 W/THE LATEST FORECAST FROM THE NERFC SHOWING THE RIVER TO HIT 14+ FT. THE RIVER IS EXPECTED TO STAY UP THROUGH THURSDAY NIGHT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1209 AM EDT TUE JUN 26 2012 .SYNOPSIS... A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION TONIGHT AND SLOWLY MOVE EASTWARD THROUGH THE NEXT 48 TO 60 HOURS. THIS WILL MEAN A WET AND UNSETTLED PATTERN THROUGH LATE WEEK. && .NEAR TERM /THROUGH TUESDAY/... UPDATE MIDNIGHT: SHOWERS CONTINUE ACROSS THE AREA MAINLY OVER THE NORTH AND OVER DOWNEAST AREAS. A CONCENTRATED AREA OF HEAVIER RAIN IS APPROACHING THE DOWNEAST COAST AND WILL LIKELY LIFT ACROSS THE REGION LATER THIS MORNING. MAIN CONCERNS ARE CONVECTION AND FLOODING. SCATTERED TSTMS ARE FIRING MAINLY ACROSS WRN AND DOWNEAST AREAS THIS AFTERNOON IN THE AXIS OF HIGH INSTABILITY. MDL SOUNDINGS INCLUDING THE LAPS INDICATE SB CAPES UP TO 2000 JOULES AND LIS HITTING -5. THETA E RIDGE ALIGNING ALONG THIS AREA INTO EASTERN MAINE ALLOWING FOR DESTABILIZATION. TSTMS WILL CARRY HAIL/HEAVY RAFL AND GUSTY WINDS AND THIS WAS ADDED TO THE FCST FOR THE EVENING. LARGE AREA OF RAIN AND EMBEDDED TSTMS ORGANIZING FROM WESTERN MAINE DOWN INTO THE COAST AND LIFTING NNE. LATEST RUNS OF THE NAM/GFS AND RUC ALONG W/THE GEM BRING THIS AREA NORTHWARD THIS EVENING INTO THE OVERNIGHT AS LOW PRES CONTINUES TO DEVELOP OVER SOUTHERN MAINE. THIS LOW WILL SLOWLY LIFT ENE THROUGH THE NEXT 24 TO 48 HRS KEEPING THE CWA IN A WET PATTERN. MDL SOUNDINGS SHOW POTENTIAL FOR HEAVY RAFL AS SSE FLOW IS ENTRENCHED FROM THE SFC UP THROUGH 500MBS AND A DEEP MOISTURE PROFILE. A FEED COMING IN FROM THE GULF OF MAINE AND ELEVATED CONVECTION WILL LEAD TO HEAVY AND POSSIBLY TORRENTIAL RAFL THIS EVENING INTO TUESDAY. THIS IN TURN WILL LEAD TO POSSIBLE FLOODING ESPECIALLY IN AREAS THAT WERE HIT HARD OVER THE WEEKEND SUCH AS BROWNVILLE, PATTEN AND SE AROOSTOOK COUNTY. AN AREAL FLOOD WARNING HAS BEEN ISSUED FOR SOUTHERN PISCATAQUIS COUNTY PER COORDINATION W/THE TOWN MANAGER. WOULD NOT BE SURPRISED TO SEE MORE WARNINGS GO UP IN THE FUTURE W/THIS SETUP. THE SSE FLOW COMING INTO SOUTHERN PENOBSCOT POSES AN ISSUE W/POSSIBLE FLOODING AND GIVEN EXPECTED QPF TOTALS CLOSING IN ON 3 INCHES, DECIDED TO INCLUDE THIS AREA IN THE FLOOD WATCH. SEE THE HYDROLOGY SECTION FOR FURTHER DETAILS. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/... A BROAD CLOSED UPPER LOW IN NEW ENGLAND WILL DOMINATE THE WEATHER INTO THURSDAY. A SURFACE LOW WILL MOVE INTO THE GULF OF MAINE AND OVER THE STATE BY TUESDAY EVENING. VERTICAL MOTIONS WITH THIS SYSTEM WILL PRODUCE SOME HEAVY RAINFALL TUESDAY INTO TUESDAY EVENING AS TROPICAL MOISTURE FEEDS INTO THE SYSTEM IN A LONG TRAJECTORY FROM TROPICAL STORM DEBBY. SOME EMBEDDED THUNDERSTORMS DOWN EAST AND AN UPSLOPE FLOW IMPINGING ON HIGHER TERRAIN FROM THE KATAHDIN REGION SOUTHWESTWARD TOWARDS THE MOOSEHEAD LAKE REGION WILL ENHANCE RAINFALL. THE WARM OCCLUSION AND ASSOCIATED WARM CONVEYOR BELT WILL MOVE NORTH AND EAST OF THE STATE LATER TUESDAY NIGHT AND THE HEAVIEST RAIN SHOULD BE OVER. HOWEVER...THE SURFACE LOW AND THE VERTICALLY STACKED UPPER LOW WILL STALL OVER MAINE BY LATER TUESDAY NIGHT AND PRODUCE MORE SHOWERY CONDITIONS INTO THURSDAY AS THE LOW SLOWLY FILLS. HAVE INCLUDED A CHANCE OF THUNDERSTORMS FOR WEDNESDAY AFTERNOON AS SOME SKINNY CAPE DEVELOPS DURING THE AFTERNOON. THE RAINY AND CLOUDY PATTERN WILL PRODUCE HIGHS IN THE MID 60S TUESDAY AND WEDNESDAY AND LOWS IN THE UPPER 50S DURING THIS PERIOD. OVERALL PRECIPITATION DURING THE PERIOD MONDAY INTO WEDNESDAY IS EXPECTED TO BE ON THE ORDER OF 2 TO 4 INCHES. THIS RAINFALL...AND ANTECEDENT MOISTURE FROM RECENT STORMS COULD CREATE ANOTHER ROUND OF FLOODING. THUS...WILL MAINTAIN EXISTING FLOOD WATCH. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... THE UPPER LOW IS E XPECTED TO SLOWLY MOVE NORTH INTO QUEBEC WEDNESDAY NIGHT INTO THURSDAY...BUT RESIDUAL MOISTURE AND INSTABILITY WILL PRODUCE ANOTHER DAY OF SHOWERS ACROSS THE FORECAST AREA. A BRIEF RESPITE IN THE RAIN EMERGES THURSDAY NIGHT INTO FRIDAY WITH A TRANSIENT RIDGE OF HIGH PRESSURE. THIS WILL LIFT HIGHS BACK TOWARDS THE LOW 80S. HOWEVER...A COLD FRONT ARRIVES IN NORTHERN MAINE BY LATE FRIDAY WITH A CHANCE OF THUNDERSTORMS IN THE EVENING. THIS FRONT WILL SLOWLY TRANSIT THE AREA SATURDAY AND KEEP A CHANCE OF THUNDERSTORMS IN NORTHERN ZONES FOR SATURDAY AS HIGHS AGAIN REACH THE LOW 80S.. EXPECTING HIGH PRESSURE TO BUILD SUNDAY...BUT CONFIDENCE IN AVOIDING INSTABILITY AND RESULTANT SHOWERS IS NOT HIGH AT THIS POINT. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... NEAR TERM: VFR W/OCNL MVFR THIS EVENING GOING TO FULL MVFR LATER TONIGHT AND THEN IFR BY TUESDAY. SHORT TERM: IFR WILL THE PREDOMINANT CONDITION FOR ALL TERMINALS TUESDAY THROUGH WEDNESDAY MORNING. SOME EMBEDDED THUNDERSTORMS ARE POSSIBLE FOR BGR AND BHB TUESDAY MORNING. CONDITIONS ARE EXPECTED TO IMPROVE TO MVFR...IF NOT VFR...WEDNESDAY AFTERNOON...BUT THUNDERSTORMS MAY DEVELOP AND CAUSE TEMPO IFR. IFR RETURNS WEDNESDAY NIGHT INTO EARLY THURSDAY BEFORE CLOUDS LIFT TO VFR OUTSIDE OF THUNDERSHOWERS. && .MARINE... NEAR TERM: DROPPED THE SCA AS WINDS/SEAS LOOK TO REMAIN BELOW THE LEVELS THROUGH TUESDAY. THERE IS STILL SOME CONCERN THAT WAVES COULD COME CLOSE TO THE 6 FOOT CRITERIA BUT ATTM KEPT THINGS BELOW. SHORT TERM: SCA MAY CONTINUE INTO TUESDAY. OTHERWISE...SOME FOG IS EXPECTED TO MATERIALIZE TUESDAY AND TUESDAY NIGHT WITH LIGHT WINDS. WAVE HTS WILL STAY NEAR 4 FT IN A SE SWELL MUCH OF THE WEEK. && .HYDROLOGY... UPDATE 2210L: FIRST ROUND OF SHOWERS DROPPED RADAR ESTIMATES OF .5 TO 1.0 INCHES OF RAIN ACROSS CENTRAL AND W CENTRAL AREAS OF OUR FA INCLUDING BROWNVILLE. THIS AREA HAS WORKED MOSTLY N AND E OF THIS AREA SO THERE WILL BE A BIT A BREAK UNTIL LATE TNGT WHEN EXPECT PRECIP TO REDEVELOP. LOCALLY HEAVY RAIN CAN THEN BE EXPECTED INTO TUE EVE. FLOOD WRNG FOR THIS AREA IN EFFECT UNTIL MID TUE AFTN... COORDINATED W/NERFC ON POTENTIAL FOR SOME MAINSTEM RIVERS TO SHOW RAPID RISES W/THE AFOREMENTIONED RAFL BUT ATTM NOT ANTICIPATING ANY MAJOR RIVERS GOING INTO FLOOD. MATTAWAMKEAG RIVER RISING STEADILY DUE TO HEAVY RAFL OVER THE WEEKEND AND ADDITIONAL RAFL WILL LEAD TO THIS SITE TO REACH NEAR FLOOD. DOVM1(DOVER-FOXCROFT) AND EVEN GRNM1(GRINDSTONE) WILL SHOW SHARP RISES ESPECIALLY LATER TUESDAY INTO TUESDAY NIGHT.THIS WILL NEED TO BE MONITORED BY LATER SHIFTS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR MEZ004>006-010-011- 015-031-032. MARINE...NONE. && $$ NEAR TERM...KHW SHORT TERM...MIGNONE LONG TERM...MIGNONE AVIATION...KHW MARINE...KHW/MIGNONE HYDROLOGY...KHW
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
354 PM EDT TUE JUN 26 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST WITH UNSEASONABLY COOL TEMPERATURES TONIGHT. TEMPERATURES WILL MODERATE EACH DAY FOR THE REMAINDER OF THE WEEK. MUCH WARMER AND MORE HUMID CONDITIONS ARE EXPECTED BY THE END OF THE WEEK WITH THE CHANCE OF SHOWERS AND THUNDERSTORMS RETURNING TO THE FORECAST. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE LATEST RUC ANALYSIS INDICATES A CLOSED UPPER LEVEL VORTEX CENTERED ACROSS NEW ENGLAND WITH DEEP MID-LEVEL RIDGING ACROSS THE CENTRAL PLAINS. THE UPPER OHIO VALLEY SITS BETWEEN THE TWO FEATURES, MORE INFLUENCED BY THE UPPER LOW, WITH A COOL NORTH- NORTHWESTERLY FLOW. AT THE SURFACE, A 1018MB HIGH IS CENTERED ACROSS LAKE MICHIGAN WITH A LOW OVER MAINE. HIGH PRESSURE IS EXTENDING INTO THE UPPER OHIO VALLEY, WITH A DEEP LAYER OF DRY AIR ABOVE 750MB. HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTHWEST TONIGHT, ALLOWING FOR SKIES TO CLEAR AND WINDS TO DECREASE TO 5 TO 10 MPH BY AROUND SUNSET. TEMPS TONIGHT ARE GENERALLY 1-2 DEGREES ABOVE A MAV/MET BLEND, WITH HIGHS RANGING FROM THE UPPER 70S ACROSS PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV TO THE UPPER 60S ACROSS THE EASTERN RIDGES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THERE IS MODEL AGREEMENT IN A DRY SYNOPTIC PATTERN FOR WEDNESDAY AND THURSDAY WITH THE UPPER LEVEL LOW PUSHING FURTHER NORTHEAST OF THE REGION AS THE MID-LEVEL RIDGE BUILDS INTO THE SOUTHEAST. 850 TEMPS WILL INCREASE TO 13-15C ON WEDNESDAY AS TEMPERATURES MODERATE CLOSER TO SEASONAL NORMALS. MODELS BEGIN TO DIVERGE IN SOLUTIONS WITH THE THERMAL STRUCTURE ALOFT ON THURSDAY. NAM/ECMWF APPEAR TO BE TOO WARM, INDICATING 850 TEMPS WARMING TO 23-25C BY 00Z FRIDAY. FORECAST IS CLOSER TO THE COOLER GFS/CANADIAN SOLUTIONS. REGARDLESS, WARMER AND MORE HUMID CONDITIONS CAN BE EXPECTED WITH HIGHS FORECAST TO BE 5 TO 10 DEGREES ABOVE NORMAL. THE AREA WILL BE ON THE NORTHERN FRINGE OF THE RIDGE THURSDAY NIGHT INTO FRIDAY, WITH MODELS DIFFERING IN THE TIMING OF SHORT WAVES MOVING ACROSS THE CROWN OF THE RIDGE AND INTO THE UPPER OHIO VALLEY. THE 12Z NAM INDICATES CONVECTION WITH A SHORT WAVE REACHING THE AREA BY AS EARLY THURSDAY NIGHT, SO HAVE BEGUN SCHC POPS THAT NIGHT. POPS INCREASE TO CHANCE ON THURSDAY WITH INCREASING DEW POINTS AND DAYTIME HEATING FUELING CONVECTION IN A WARM AND HUMID AIR MASS. THERE IS AGAIN QUITE A SPREAD IN HIGH TEMPS BETWEEN THE MODELS ON FRIDAY. TAKING INTO CONSIDERATION INCREASED CLOUD COVERAGE WITH CONVECTION, HIGHS ARE FORECAST TO RANGE FROM THE LOW 90S IN EASTERN OHIO AND NORTH-CENTRAL WV TO THE MID 80S NORTH OF I-80 AND ACROSS THE EASTERN RIDGES. HIGHS ARE CLOSEST TO THE NAM, WHICH IS THE MIDDLE GROUND BETWEEN THE NEAR RECORD TEMPS FORECAST BY THE ECMWF AND THE COOLER GFS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE MODELS MAINTAIN A FLAT RIDGE OVER THE CENTRAL U.S. AND A TROUGH NORTH AND EAST OF THE GREAT LAKES THROUGH THE EXTENDED PERIOD. THIS PATTERN SHOULD KEEP TEMPERATURES WELL ABOVE NORMAL FOR THE EXTENDED PERIOD. HIGHS WERE FORECAST 3 TO 5 DEGREES UNDER HPC GUIDANCE...BUT CLOSER TO GFS MOS. MODELS SHOW SEVERAL WEAK DISTURBANCES RIDING IN WEST-NORTHWEST FLOW ACROSS THE REGION DURING THE WEEKEND INTO MONDAY...WHILE A SURFACE BOUNDARY WAVERS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. TIMING OF AREAS OF PRECIPITATION REMAINS DIFFICULT AT THIS POINT...SO WILL KEEP CHANCE POPS THROUGH MONDAY EVENING...THEN DRIER ON TUESDAY. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. NORTH SURFACE WINDS WILL GUST TO AROUND 20 KT...THEN DIMINISH AFTER 00Z AS MIXING FROM DIURNAL HEATING ENDS. OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY... GENERALLY VFR IS EXPECTED TO PREVAIL...BUT AREAS OF MORNING FOG AND HAZE ARE POSSIBLE BY THE WEEKEND AS LOW LEVEL MOISTURE INCREASES. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH THE POTENTIAL FOR RESTRICTIONS CAN BE EXPECTED BEGINNING FRIDAY INTO THE THE WEEKEND AS UPPER DISTURBANCES AND A WEAK COLD FRONT CROSS THE REGION. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
348 PM EDT TUE JUN 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE BUILDS INTO THE REGION THROUGH TONIGHT...THEN SETTLES ACROSS THE SOUTHEAST STATES WEDNESDAY. A STRONG UPPER LEVEL RIDGE BUILDS IN FROM THE WEST LATER IN THE WEEK...LEADING TO ANOTHER ROUND OF HOT WEATHER INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... NOTE: INITIAL FINDINGS FROM OFFICE`S SURVEY TEAM DISPATCHED TO RIC AREA (AND IMMEDIATELY NW INVOF I64) (CHECKING OUT TSTM DAMAGE FM MON AFTN). 1. CONFIRMED EF0 TORNADO DAMAGE IN GOOCHLAND COUNTY...GENERALLY NEAR COUNTY LINE RD TO HICKORY HILL RD. 2. LARGE SCALE DERECHO FROM AROUND OILVILLE IN GOOCHLAND COUNTY TO ROCKVILLE IN WESTERN HANOVER COUNTY. IN THAT AREA...WIDESPREAD STRAIGHT LINE WIND DAMAGE. NUMEROUS TREES DAMAGED/UPROOTED; 3-4 FOOT DIAMETER TREES SNAPPED HALF WAY UP. WIND SPEEDS EST 80 TO 100 MPH. THE TEAM IS NOW HEADED TO WESTERN HENRICO COUNTY. MORE INFORMATION WILL BE FORTHCOMING. A DETAILED PNS (PUBLIC INFORMATION STATEMENT) WILL BE ISSUED UPON THEIR RETURN THIS EVENING. DISCUSSION: SFC HI PRES LCTD OVR OH VLY CONTS TO BUILD TWD THE FA THROUGH TNGT. DRY NNW LLVL FLO RESULTING IN A VRY COMFY LT JUNE AFTN...AND CONDS WL RMN SO THROUGH TNGT. WNDS GUSTY TO 20-30 MPH...HIGHEST E...A LTL WHILE LONGER...XPCD TO DCRS DURG THE EVE HRS. DEWPTS CURRENTLY RUNNING FM THE U40S TO L50S. SOME RECOVERY XPCD INTO TNGT...THOUGH WILL BE LRGLY IN THE 50S. W/ THAT IN MIND...LO TEMPS WL RANGE THROUGH THE 50S TO ARND 60F. XPCG GENLY SKC...W/ XCPTN BEING FAR SE VA INTO NE NC WHERE THERE WL BE BKN-OVC CI. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE THEME OF THE WX FM WED THROUGH FRI WL BE INCRSG WARMTH. SFC HI PRES SETTLES INTO THE SE STATES WED...AS STRNG RIDGE ALOFT INVOF PLAINS STATES BEGINS TO EXPAND EWD. AT THE SAME TIME...LO PRES INVOF XTRM ERN NEW ENG IS SLO TO LIFT OUT TO THE ENE. XPCG A MSNY DAY ON WED...W/ TEMPS RISING INTO THE 80S. DEWPTS TO RMN QUITE LO...W/ AFTN READINGS LRGLY ARND 50F. THE MID/UPPER ANTICYCLONE FLATTENS AND SHIFTS TO THE MS VLY WED NIGHT AND THU. PASSING HIGH CLOUDS ARE PSBL IN REMNANT NW FLO ALOFT ON THE NORTHERN PERIPHERY OF THE RIDGE...BUT THE SKY SHOULD LRGLY RMN MSTLY SKC/SNY ACRS THE FA. HIGH TEMPERATURES THURSDAY ARE EXPECTED TO RETURN TO THE LOW TO MID 90S...AFTER MORNING LOWS OF 55-65F. DEWPOINTS ARE EXPECTED TO BE IN THE U50S-L60S DURING PEAK HEATING THU...SO HEAT INDICES WILL BE SIMILAR TO THE AMBIENT TEMPERATURE. B4 EVEN HOTTER AMS ARRIVES FM THE W ON FRI...WL NEED TO WATCH FOR PSBL CNVTN MOVG SE IN RESIDUAL NW FLO ALOFT (FM THE ERN OH VLY) (PRIMARILY LT THU NGT/FRI MRNG). WL CONT W/ SLGT CHC-LO CHC (20-30% POPS) OVR THE NRN 2/3RDS OF FA ON FRI. OTRW...MDL LLVL THICKNESS SUGGEST TEMPS TAKE A RUN AT 100F ACRS INTR SXNS OF FA...AND L/M90S EVEN TO THE CST. UNLIKE HOT WX FM 19TH-22ND THIS MONTH WHEN UPR LVL RIDGE WAS HIGHLY AMPLIFIED (WELL N INTO SE CANADA)...THIS TIME ARND...RIDGE ALOFT IS MUCH FLATTER...AND THE XTRM HEAT WL BE TARGETING THE MDATLC STATES/CAROLINAS (AND MOST LIKELY NOT INCLD THE NE CONUS). W/ DP LYR FLO MR WSWLY THIS TIME ARND...LIKELY TO TAKE LNGR FOR MUCH HIGHER DEWPTS TO REACH THE FA. W/ THAT IN MIND...WL KP HEAT INDICES ON FRI BLO 105F ACRS FA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE BEGINNING OF THE LONG TERM PERIOD IS DOMINATED BY A FLAT RIDGE THAT BUILDS EASTWARD INTO THE MID ATLANTIC STATES. THIS WILL PROVIDE MOSTLY DRY WEATHER...BUT LOTS OF HEAT. EXPECT TO SEE TEMPERATURES CLIMB INTO THE UPPER 90S TO LOW 100S FRIDAY AND SATURDAY...WITH HEAT INDEX VALUES OF 100 TO 105 AS DEW POINTS FALL DURING PEAK MIXING TIMES IN THE AFTERNOON. A WEAK FRONTAL BOUNDARY MOVES THROUGH THE GREAT LAKE STATES THU INTO FRI...BEFORE STALLING NORTH OF THE REGION OVER THE WEEKEND. THE COMBINATION OF THE STALLED FRONT...THE LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES COULD PRODUCE SOME AFTERNOON AND EVENING CONVECTION...BUT EXPECT THAT WITH THE DRY AIR ASSOCIATED WITH THE RIDGE THAT THE STORMS WOULD BE ISOLATED. FOR SUNDAY INTO MONDAY...THE RIDGE BEGINS TO BREAK DOWN AND THE HEAT MAY BACK OFF A LITTLE...BUT THERE IS MORE UNCERTAINTY IN THIS PART OF THE FORECAST AS THE MODELS STRUGGLE TO HANDLE WHERE TS DEBBY WILL GO. FOR NOW HAVE ALLOWED A BIT MORE CLOUD COVER OVER THE SERN PART OF THE CWA BASED ON DEBBY HEADING THROUGH THE SW ATLANTIC LATE IN THE PERIOD. BUT WILL HAVE TO MONITOR OVER THE NEXT SEVERAL DAYS. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... NORTHERLY WINDS WILL BE GUSTY AT TIMES TODAY DURING THE LATE MORNING AND AFTN. WINDS DIMINISH TUESDAY EVENING. LOW DEW POINTS WILL PROMOTE VFR CONDS THROUGH THE PERIOD. OUTLOOK...MAINLY VFR AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. MVFR CONDS WILL BE PSBL DURG THE EARLY MRNG HOURS BY THIS WEEKEND. ALSO THERE WILL BE SLIGHT CHANCES FOR TSTMS DURING THE AFTN HOURS OVER THE WEEKEND. && .MARINE... NORTHERLY WINDS OF 20 TO 25 KTS OVER THE BAY AND COASTAL WATERS WILL DIMINISH SLOWLY DURING THE DAY TODAY. FOLLOWED CLOSE TO HRRR THIS MORNING AND WENT WITH HIGH SIDE OF GUIDANCE THROUGH THE AFTN. HAVE SCA ENDING BY 17Z EXCEPT CONTINUED TIL 20Z IN THE COASTAL WATERS SOUTH OF PARRAMORE ISLAND AND THE MOUTH OF THE BAY. SCA FOR THE COASTAL WATERS IS MOSTLY FOR 5 FOOT SEAS. WIND DIMINISH THIS EVENING AND THEN INCREASE WITH A SECONDARY NW SURGE EARLY WEDNESDAY MORNING. AT THIS POINT...IT APPEARS THAT THIS WILL REMAIN BELOW SCA CRITERIA. S/SW WINDS INCREASE TO AROUND 15 KNOTS FRIDAY AND SATURDAY OVER THE COASTAL WATERS AND SEAS MAY APPROACH 5 FT BUT KEEPING THEM AT 4 FT OR LESS AT THIS POINT. && .CLIMATE... RECORD HIGH TEMPERATURES: FRIDAY JUNE 29 TO SUNDAY JULY 1 6/29 6/30 7/1 RIC 101/1980 103/1936 102/1945 ORF 100/1980 101/1936 100/1901 SBY 98/1959 99/1934 98/1968 ECG 97/2010 100/1936 98/1945 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...ALB SHORT TERM...ALB LONG TERM...ESS AVIATION...LSA MARINE...LSA CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
346 PM EDT TUE JUN 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE BUILDS INTO THE REGION THROUGH TONIGHT...THEN SETTLES ACROSS THE SOUTHEAST STATES WEDNESDAY. A STRONG UPPER LEVEL RIDGE BUILDS IN FROM THE WEST LATER IN THE WEEK...LEADING TO ANOTHER ROUND OF HOT WEATHER INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... NOTE: INITIAL FINDINGS FROM OFFICE`S SURVEY TEAM DISPATCHED TO RIC AREA (AND IMMEDIATELY NW INVOF I64) (CHECKING OUT TSTM DAMAGE FM MON AFTN). 1. CONFIRMED EF0 TORNADO DAMAGE IN EASTERN GOOCHLAND COUNTY...GENERALLY NEAR COUNTY LINE RD TO HICKORY HILL RD. 2. LARGE SCALE DERECHO FROM AROUND OILVILLE IN GOOCHLAND COUNTY TO ROCKVILLE IN WESTERN HANOVER COUNTY. IN THAT AREA...WIDESPREAD STRAIGHT LINE WIND DAMAGE. NUMEROUS TREES DAMAGED/UPROOTED; 3-4 FOOT DIAMETER TREES SNAPPED HALF WAY UP. WIND SPEEDS EST 80 TO 100 MPH. THE TEAM IS NOW HEADED TO WESTERN HENRICO COUNTY. MORE INFORMATION WILL BE FORTHCOMING. A DETAILED PNS (PUBLIC INFORMATION STATEMENT) WILL BE ISSUED UPON THEIR RETURN THIS EVENING. DISCUSSION: SFC HI PRES LCTD OVR OH VLY CONTS TO BUILD TWD THE FA THROUGH TNGT. DRY NNW LLVL FLO RESULTING IN A VRY COMFY LT JUNE AFTN...AND CONDS WL RMN SO THROUGH TNGT. WNDS GUSTY TO 20-30 MPH...HIGHEST E...A LTL WHILE LONGER...XPCD TO DCRS DURG THE EVE HRS. DEWPTS CURRENTLY RUNNING FM THE U40S TO L50S. SOME RECOVERY XPCD INTO TNGT...THOUGH WILL BE LRGLY IN THE 50S. W/ THAT IN MIND...LO TEMPS WL RANGE THROUGH THE 50S TO ARND 60F. XPCG GENLY SKC...W/ XCPTN BEING FAR SE VA INTO NE NC WHERE THERE WL BE BKN-OVC CI. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE THEME OF THE WX FM WED THROUGH FRI WL BE INCRSG WARMTH. SFC HI PRES SETTLES INTO THE SE STATES WED...AS STRNG RIDGE ALOFT INVOF PLAINS STATES BEGINS TO EXPAND EWD. AT THE SAME TIME...LO PRES INVOF XTRM ERN NEW ENG IS SLO TO LIFT OUT TO THE ENE. XPCG A MSNY DAY ON WED...W/ TEMPS RISING INTO THE 80S. DEWPTS TO RMN QUITE LO...W/ AFTN READINGS LRGLY ARND 50F. THE MID/UPPER ANTICYCLONE FLATTENS AND SHIFTS TO THE MS VLY WED NIGHT AND THU. PASSING HIGH CLOUDS ARE PSBL IN REMNANT NW FLO ALOFT ON THE NORTHERN PERIPHERY OF THE RIDGE...BUT THE SKY SHOULD LRGLY RMN MSTLY SKC/SNY ACRS THE FA. HIGH TEMPERATURES THURSDAY ARE EXPECTED TO RETURN TO THE LOW TO MID 90S...AFTER MORNING LOWS OF 55-65F. DEWPOINTS ARE EXPECTED TO BE IN THE U50S-L60S DURING PEAK HEATING THU...SO HEAT INDICES WILL BE SIMILAR TO THE AMBIENT TEMPERATURE. B4 EVEN HOTTER AMS ARRIVES FM THE W ON FRI...WL NEED TO WATCH FOR PSBL CNVTN MOVG SE IN RESIDUAL NW FLO ALOFT (FM THE ERN OH VLY) (PRIMARILY LT THU NGT/FRI MRNG). WL CONT W/ SLGT CHC-LO CHC (20-30% POPS) OVR THE NRN 2/3RDS OF FA ON FRI. OTRW...MDL LLVL THICKNESS SUGGEST TEMPS TAKE A RUN AT 100F ACRS INTR SXNS OF FA...AND L/M90S EVEN TO THE CST. UNLIKE HOT WX FM 19TH-22ND THIS MONTH WHEN UPR LVL RIDGE WAS HIGHLY AMPLIFIED (WELL N INTO SE CANADA)...THIS TIME ARND...RIDGE ALOFT IS MUCH FLATTER...AND THE XTRM HEAT WL BE TARGETING THE MDATLC STATES/CAROLINAS (AND MOST LIKELY NOT INCLD THE NE CONUS). W/ DP LYR FLO MR WSWLY THIS TIME ARND...LIKELY TO TAKE LNGR FOR MUCH HIGHER DEWPTS TO REACH THE FA. W/ THAT IN MIND...WL KP HEAT INDICES ON FRI BLO 105F ACRS FA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE BEGINNING OF THE LONG TERM PERIOD IS DOMINATED BY A FLAT RIDGE THAT BUILDS EASTWARD INTO THE MID ATLANTIC STATES. THIS WILL PROVIDE MOSTLY DRY WEATHER...BUT LOTS OF HEAT. EXPECT TO SEE TEMPERATURES CLIMB INTO THE UPPER 90S TO LOW 100S FRIDAY AND SATURDAY...WITH HEAT INDEX VALUES OF 100 TO 105 AS DEW POINTS FALL DURING PEAK MIXING TIMES IN THE AFTERNOON. A WEAK FRONTAL BOUNDARY MOVES THROUGH THE GREAT LAKE STATES THU INTO FRI...BEFORE STALLING NORTH OF THE REGION OVER THE WEEKEND. THE COMBINATION OF THE STALLED FRONT...THE LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES COULD PRODUCE SOME AFTERNOON AND EVENING CONVECTION...BUT EXPECT THAT WITH THE DRY AIR ASSOCIATED WITH THE RIDGE THAT THE STORMS WOULD BE ISOLATED. FOR SUNDAY INTO MONDAY...THE RIDGE BEGINS TO BREAK DOWN AND THE HEAT MAY BACK OFF A LITTLE...BUT THERE IS MORE UNCERTAINTY IN THIS PART OF THE FORECAST AS THE MODELS STRUGGLE TO HANDLE WHERE TS DEBBY WILL GO. FOR NOW HAVE ALLOWED A BIT MORE CLOUD COVER OVER THE SERN PART OF THE CWA BASED ON DEBBY HEADING THROUGH THE SW ATLANTIC LATE IN THE PERIOD. BUT WILL HAVE TO MONITOR OVER THE NEXT SEVERAL DAYS. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... NORTHERLY WINDS WILL BE GUSTY AT TIMES TODAY DURING THE LATE MORNING AND AFTN. WINDS DIMINISH TUESDAY EVENING. LOW DEW POINTS WILL PROMOTE VFR CONDS THROUGH THE PERIOD. OUTLOOK...MAINLY VFR AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. MVFR CONDS WILL BE PSBL DURG THE EARLY MRNG HOURS BY THIS WEEKEND. ALSO THERE WILL BE SLIGHT CHANCES FOR TSTMS DURING THE AFTN HOURS OVER THE WEEKEND. && .MARINE... NORTHERLY WINDS OF 20 TO 25 KTS OVER THE BAY AND COASTAL WATERS WILL DIMINISH SLOWLY DURING THE DAY TODAY. FOLLOWED CLOSE TO HRRR THIS MORNING AND WENT WITH HIGH SIDE OF GUIDANCE THROUGH THE AFTN. HAVE SCA ENDING BY 17Z EXCEPT CONTINUED TIL 20Z IN THE COASTAL WATERS SOUTH OF PARRAMORE ISLAND AND THE MOUTH OF THE BAY. SCA FOR THE COASTAL WATERS IS MOSTLY FOR 5 FOOT SEAS. WIND DIMINISH THIS EVENING AND THEN INCREASE WITH A SECONDARY NW SURGE EARLY WEDNESDAY MORNING. AT THIS POINT...IT APPEARS THAT THIS WILL REMAIN BELOW SCA CRITERIA. S/SW WINDS INCREASE TO AROUND 15 KNOTS FRIDAY AND SATURDAY OVER THE COASTAL WATERS AND SEAS MAY APPROACH 5 FT BUT KEEPING THEM AT 4 FT OR LESS AT THIS POINT. && .CLIMATE... RECORD HIGH TEMPERATURES: FRIDAY JUNE 29 TO SUNDAY JULY 1 6/29 6/30 7/1 RIC 101/1980 103/1936 102/1945 ORF 100/1980 101/1936 100/1901 SBY 98/1959 99/1934 98/1968 ECG 97/2010 100/1936 98/1945 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ630>638-654-656-658. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...ALB SHORT TERM...ALB LONG TERM...ESS AVIATION...LSA MARINE...LSA CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
318 PM EDT TUE JUN 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE BUILDS INTO THE REGION THROUGH TONIGHT...THEN SETTLES ACROSS THE SOUTHEAST STATES WEDNESDAY. A STRONG UPPER LEVEL RIDGE BUILDS IN FROM THE WEST LATER IN THE WEEK...LEADING TO ANOTHER ROUND OF HOT WEATHER INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... SFC HI PRES LCTD OVR OH VLY CONTS TO BUILD TWD THE FA THROUGH TNGT. DRY NNW LLVL FLO RESULTING IN A VRY COMFY LT JUNE AFTN...AND CONDS WL RMN SO THROUGH TNGT. WNDS GUSTY TO 20-30 MPH...HIGHEST E...A LTL WHILE LONGER...XPCD TO DCRS DURG THE EVE HRS. DEWPTS CURRENTLY RUNNING FM THE U40S TO L50S. SOME RECOVERY XPCD INTO TNGT...THOUGH WILL BE LRGLY IN THE 50S. W/ THAT IN MIND...LO TEMPS WL RANGE THROUGH THE 50S TO ARND 60F. XPCG GENLY SKC...W/ XCPTN BEING FAR SE VA INTO NE NC WHERE THERE WL BE BKN-OVC CI. NOTE: TEAM DISPATCHED TO RIC AREA (AND IMMEDIATELY NW INVOF I64) TO CHECK OUT TSTM DAMAGE FM MON AFTN. AS OF MID THIS AFTN...NO WORD ON THEIR FINDINGS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE THEME OF THE WX FM WED THROUGH FRI WL BE INCRSG WARMTH. SFC HI PRES SETTLES INTO THE SE STATES WED...AS STRNG RIDGE ALOFT INVOF PLAINS STATES BEGINS TO EXPAND EWD. AT THE SAME TIME...LO PRES INVOF XTRM ERN NEW ENG IS SLO TO LIFT OUT TO THE ENE. XPCG A MSNY DAY ON WED...W/ TEMPS RISING INTO THE 80S. DEWPTS TO RMN QUITE LO...W/ AFTN READINGS LRGLY ARND 50F. THE MID/UPPER ANTICYCLONE FLATTENS AND SHIFTS TO THE MS VLY WED NIGHT AND THU. PASSING HIGH CLOUDS ARE PSBL IN REMNANT NW FLO ALOFT ON THE NORTHERN PERIPHERY OF THE RIDGE...BUT THE SKY SHOULD LRGLY RMN MSTLY SKC/SNY ACRS THE FA. HIGH TEMPERATURES THURSDAY ARE EXPECTED TO RETURN TO THE LOW TO MID 90S...AFTER MORNING LOWS OF 55-65F. DEWPOINTS ARE EXPECTED TO BE IN THE U50S-L60S DURING PEAK HEATING THU...SO HEAT INDICES WILL BE SIMILAR TO THE AMBIENT TEMPERATURE. B4 EVEN HOTTER AMS ARRIVES FM THE W ON FRI...WL NEED TO WATCH FOR PSBL CNVTN MOVG SE IN RESIDUAL NW FLO ALOFT (FM THE ERN OH VLY) (PRIMARILY LT THU NGT/FRI MRNG). WL CONT W/ SLGT CHC-LO CHC (20-30% POPS) OVR THE NRN 2/3RDS OF FA ON FRI. OTRW...MDL LLVL THICKNESS SUGGEST TEMPS TAKE A RUN AT 100F ACRS INTR SXNS OF FA...AND L/M90S EVEN TO THE CST. UNLIKE HOT WX FM 19TH-22ND THIS MONTH WHEN UPR LVL RIDGE WAS HIGHLY AMPLIFIED (WELL N INTO SE CANADA)...THIS TIME ARND...RIDGE ALOFT IS MUCH FLATTER...AND THE XTRM HEAT WL BE TARGETING THE MDATLC STATES/CAROLINAS (AND MOST LIKELY NOT INCLD THE NE CONUS). W/ DP LYR FLO MR WSWLY THIS TIME ARND...LIKELY TO TAKE LNGR FOR MUCH HIGHER DEWPTS TO REACH THE FA. W/ THAT IN MIND...WL KP HEAT INDICES ON FRI BLO 105F ACRS FA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE BEGINNING OF THE LONG TERM PERIOD IS DOMINATED BY A FLAT RIDGE THAT BUILDS EASTWARD INTO THE MID ATLANTIC STATES. THIS WILL PROVIDE MOSTLY DRY WEATHER...BUT LOTS OF HEAT. EXPECT TO SEE TEMPERATURES CLIMB INTO THE UPPER 90S TO LOW 100S FRIDAY AND SATURDAY...WITH HEAT INDEX VALUES OF 100 TO 105 AS DEW POINTS FALL DURING PEAK MIXING TIMES IN THE AFTERNOON. A WEAK FRONTAL BOUNDARY MOVES THROUGH THE GREAT LAKE STATES THU INTO FRI...BEFORE STALLING NORTH OF THE REGION OVER THE WEEKEND. THE COMBINATION OF THE STALLED FRONT...THE LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES COULD PRODUCE SOME AFTERNOON AND EVENING CONVECTION...BUT EXPECT THAT WITH THE DRY AIR ASSOCIATED WITH THE RIDGE THAT THE STORMS WOULD BE ISOLATED. FOR SUNDAY INTO MONDAY...THE RIDGE BEGINS TO BREAK DOWN AND THE HEAT MAY BACK OFF A LITTLE...BUT THERE IS MORE UNCERTAINTY IN THIS PART OF THE FORECAST AS THE MODELS STRUGGLE TO HANDLE WHERE TS DEBBY WILL GO. FOR NOW HAVE ALLOWED A BIT MORE CLOUD COVER OVER THE SERN PART OF THE CWA BASED ON DEBBY HEADING THROUGH THE SW ATLANTIC LATE IN THE PERIOD. BUT WILL HAVE TO MONITOR OVER THE NEXT SEVERAL DAYS. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... NORTHERLY WINDS WILL BE GUSTY AT TIMES TODAY DURING THE LATE MORNING AND AFTN. WINDS DIMINISH TUESDAY EVENING. LOW DEW POINTS WILL PROMOTE VFR CONDS THROUGH THE PERIOD. OUTLOOK...MAINLY VFR AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. MVFR CONDS WILL BE PSBL DURG THE EARLY MRNG HOURS BY THIS WEEKEND. ALSO THERE WILL BE SLIGHT CHANCES FOR TSTMS DURING THE AFTN HOURS OVER THE WEEKEND. && .MARINE... NORTHERLY WINDS OF 20 TO 25 KTS OVER THE BAY AND COASTAL WATERS WILL DIMINISH SLOWLY DURING THE DAY TODAY. FOLLOWED CLOSE TO HRRR THIS MORNING AND WENT WITH HIGH SIDE OF GUIDANCE THROUGH THE AFTN. HAVE SCA ENDING BY 17Z EXCEPT CONTINUED TIL 20Z IN THE COASTAL WATERS SOUTH OF PARRAMORE ISLAND AND THE MOUTH OF THE BAY. SCA FOR THE COASTAL WATERS IS MOSTLY FOR 5 FOOT SEAS. WIND DIMINISH THIS EVENING AND THEN INCREASE WITH A SECONDARY NW SURGE EARLY WEDNESDAY MORNING. AT THIS POINT...IT APPEARS THAT THIS WILL REMAIN BELOW SCA CRITERIA. S/SW WINDS INCREASE TO AROUND 15 KNOTS FRIDAY AND SATURDAY OVER THE COASTAL WATERS AND SEAS MAY APPROACH 5 FT BUT KEEPING THEM AT 4 FT OR LESS AT THIS POINT. && .CLIMATE... RECORD HIGH TEMPERATURES: FRIDAY JUNE 29 TO SUNDAY JULY 1 6/29 6/30 7/1 RIC 101/1980 103/1936 102/1945 ORF 100/1980 101/1936 100/1901 SBY 98/1959 99/1934 98/1968 ECG 97/2010 100/1936 98/1945 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ630>638-654-656-658. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...ALB SHORT TERM...ALB LONG TERM...ESS AVIATION...LSA MARINE...LSA CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
311 PM EDT TUE JUN 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE BUILDS INTO THE REGION THROUGH TONIGHT...THEN SETTLES ACROSS THE SOUTHEAST STATES WEDNESDAY. A STRONG UPPER LEVEL RIDGE BUILDS IN FROM THE WEST LATER IN THE WEEK...LEADING TO ANOTHER ROUND OF HOT WEATHER INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... SFC HI PRES LCTD OVR OH VLY CONTS TO BUILD TWD THE FA THROUGH TNGT. DRY NNW LLVL FLO RESULTING IN A VRY COMFY LT JUNE AFTN...AND CONDS WL RMN SO THROUGH TNGT. WNDS GUSTY TO 20-30 MPH...HIGHEST E...A LTL WHILE LONGER...XPCD TO DCRS DURG THE EVE HRS. DEWPTS CURRENTLY RUNNING FM THE U40S TO L50S. SOME RECOVERY XPCD INTO TNGT...THOUGH WILL BE LRGLY IN THE 50S. W/ THAT IN MIND...LO TEMPS WL RANGE THROUGH THE 50S TO ARND 60F. XPCG GENLY SKC...W/ XCPTN BEING FAR SE VA INTO NE NC WHERE THERE WL BE BKN-OVC CI. NOTE: TEAM DISPATCHED TO RIC AREA (AND IMMEDIATELY NW INVOF I64) TO CHECK OUT TSTM DAMAGE FM TUE AFTN. AS OF MID THIS AFTN...NO WORD ON THEIR FINDINGS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... THE THEME OF THE WX FM WED THROUGH FRI WL BE INCRSG WARMTH. SFC HI PRES SETTLES INTO THE SE STATES WED...AS STRNG RIDGE ALOFT INVOF PLAINS STATES BEGINS TO EXPAND EWD. AT THE SAME TIME...LO PRES INVOF XTRM ERN NEW ENG IS SLO TO LIFT OUT TO THE ENE. XPCG A MSNY DAY ON WED...W/ TEMPS RISING INTO THE 80S. DEWPTS TO RMN QUITE LO...W/ AFTN READINGS LRGLY ARND 50F. THE MID/UPPER ANTICYCLONE FLATTENS AND SHIFTS TO THE MS VLY WED NIGHT AND THU. PASSING HIGH CLOUDS ARE PSBL IN REMNANT NW FLO ALOFT ON THE NORTHERN PERIPHERY OF THE RIDGE...BUT THE SKY SHOULD LRGLY RMN MSTLY SKC/SNY ACRS THE FA. HIGH TEMPERATURES THURSDAY ARE EXPECTED TO RETURN TO THE LOW TO MID 90S...AFTER MORNING LOWS OF 55-65F. DEWPOINTS ARE EXPECTED TO BE IN THE U50S-L60S DURING PEAK HEATING THU...SO HEAT INDICES WILL BE SIMILAR TO THE AMBIENT TEMPERATURE. B4 EVEN HOTTER AMS ARRIVES FM THE W ON FRI...WL NEED TO WATCH FOR PSBL CNVTN MOVG SE IN RESIDUAL NW FLO ALOFT (FM THE ERN OH VLY) (PRIMARILY LT THU NGT/FRI MRNG). WL CONT W/ SLGT CHC-LO CHC (20-30% POPS) OVR THE NRN 2/3RDS OF FA ON FRI. OTRW...MDL LLVL THICKNESS SUGGEST TEMPS TAKE A RUN AT 100F ACRS INTR SXNS OF FA...AND L/M90S EVEN TO THE CST. UNLIKE HOT WX FM 19TH-22ND THIS MONTH WHEN UPR LVL RIDGE WAS HIGHLY AMPLIFIED (WELL N INTO SE CANADA)...THIS TIME ARND...RIDGE ALOFT IS MUCH FLATTER...AND THE XTRM HEAT WL BE TARGETING THE MDATLC STATES/CAROLINAS (AND MOST LIKELY NOT INCLD THE NE CONUS). W/ DP LYR FLO MR WSWLY THIS TIME ARND...LIKELY TO TAKE LNGR FOR MUCH HIGHER DEWPTS TO REACH THE FA. W/ THAT IN MIND...WL KP HEAT INDICES ON FRI BLO 105F ACRS FA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE BEGINNING OF THE LONG TERM PERIOD IS DOMINATED BY A FLAT RIDGE THAT BUILDS EASTWARD INTO THE MID ATLANTIC STATES. THIS WILL PROVIDE MOSTLY DRY WEATHER...BUT LOTS OF HEAT. EXPECT TO SEE TEMPERATURES CLIMB INTO THE UPPER 90S TO LOW 100S FRIDAY AND SATURDAY...WITH HEAT INDEX VALUES OF 100 TO 105 AS DEW POINTS FALL DURING PEAK MIXING TIMES IN THE AFTERNOON. A WEAK FRONTAL BOUNDARY MOVES THROUGH THE GREAT LAKE STATES THU INTO FRI...BEFORE STALLING NORTH OF THE REGION OVER THE WEEKEND. THE COMBINATION OF THE STALLED FRONT...THE LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES COULD PRODUCE SOME AFTERNOON AND EVENING CONVECTION...BUT EXPECT THAT WITH THE DRY AIR ASSOCIATED WITH THE RIDGE THAT THE STORMS WOULD BE ISOLATED. FOR SUNDAY INTO MONDAY...THE RIDGE BEGINS TO BREAK DOWN AND THE HEAT MAY BACK OFF A LITTLE...BUT THERE IS MORE UNCERTAINTY IN THIS PART OF THE FORECAST AS THE MODELS STRUGGLE TO HANDLE WHERE TS DEBBY WILL GO. FOR NOW HAVE ALLOWED A BIT MORE CLOUD COVER OVER THE SERN PART OF THE CWA BASED ON DEBBY HEADING THROUGH THE SW ATLANTIC LATE IN THE PERIOD. BUT WILL HAVE TO MONITOR OVER THE NEXT SEVERAL DAYS. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... NORTHERLY WINDS WILL BE GUSTY AT TIMES TODAY DURING THE LATE MORNING AND AFTN. WINDS DIMINISH TUESDAY EVENING. LOW DEW POINTS WILL PROMOTE VFR CONDS THROUGH THE PERIOD. OUTLOOK...MAINLY VFR AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. MVFR CONDS WILL BE PSBL DURG THE EARLY MRNG HOURS BY THIS WEEKEND. ALSO THERE WILL BE SLIGHT CHANCES FOR TSTMS DURING THE AFTN HOURS OVER THE WEEKEND. && .MARINE... NORTHERLY WINDS OF 20 TO 25 KTS OVER THE BAY AND COASTAL WATERS WILL DIMINISH SLOWLY DURING THE DAY TODAY. FOLLOWED CLOSE TO HRRR THIS MORNING AND WENT WITH HIGH SIDE OF GUIDANCE THROUGH THE AFTN. HAVE SCA ENDING BY 17Z EXCEPT CONTINUED TIL 20Z IN THE COASTAL WATERS SOUTH OF PARRAMORE ISLAND AND THE MOUTH OF THE BAY. SCA FOR THE COASTAL WATERS IS MOSTLY FOR 5 FOOT SEAS. WIND DIMINISH THIS EVENING AND THEN INCREASE WITH A SECONDARY NW SURGE EARLY WEDNESDAY MORNING. AT THIS POINT...IT APPEARS THAT THIS WILL REMAIN BELOW SCA CRITERIA. S/SW WINDS INCREASE TO AROUND 15 KNOTS FRIDAY AND SATURDAY OVER THE COASTAL WATERS AND SEAS MAY APPROACH 5 FT BUT KEEPING THEM AT 4 FT OR LESS AT THIS POINT. && .CLIMATE... RECORD HIGH TEMPERATURES: FRIDAY JUNE 29 TO SUNDAY JULY 1 6/29 6/30 7/1 RIC 101/1980 103/1936 102/1945 ORF 100/1980 101/1936 100/1901 SBY 98/1959 99/1934 98/1968 ECG 97/2010 100/1936 98/1945 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ630>638-654-656-658. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...ALB SHORT TERM...ALB LONG TERM...ESS AVIATION...LSA MARINE...LSA CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
124 PM EDT TUE JUN 26 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINTAIN A NORTHERLY FLOW OVER THE AREA WITH DRY AND COOL WEATHER THROUGH WEDNESDAY. WARMER TEMPERATURES CAN BE EXPECTED FOR THE LATTER HALF OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... 18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT FOR THE LATEST TRENDS IN OBS. THE LATEST RUC ANALYSIS INDICATES A CLOSED UPPER LEVEL VORTEX CENTERED ACROSS NEW ENGLAND WITH DEEP MID-LEVEL RIDGING ACROSS THE CENTRAL PLAINS. THE UPPER OHIO VALLEY SITS BETWEEN THE TWO FEATURES, MORE INFLUENCED BY THE UPPER LOW, WITH A COOL NORTH- NORTHWESTERLY FLOW TODAY. AT THE SURFACE, A 1018MB HIGH IS CENTERED ACROSS LAKE MICHIGAN WITH A LOW OVER MAINE. HIGH PRESSURE IS EXTENDING INTO THE UPPER OHIO VALLEY, WITH A DEEP LAYER OF DRY AIR ABOVE 750MB. HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTHWEST TODAY, ALLOWING FOR ANOTHER DRY DAY. A TIGHTENED PRESSURE GRADIENT WITH DIURNAL MIXING WILL ALLOW FOR WINDS AT 10 TO 15 MPH TO GUST TO AROUND 25 MPH AT TIMES TODAY. DIURNAL CUMULUS WILL MAKE FOR PARTLY CLOUDY SKIES THROUGH MOST OF THE DAY, WITH CLOUD COVERAGE DIMINISHING BY SUNSET. TEMPS TODAY ARE GENERALLY 1-2 DEGREES ABOVE A MAV/MET BLEND, WITH HIGHS RANGING FROM THE UPPER 70S ACROSS PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV TO THE UPPER 60S ACROSS THE EASTERN RIDGES. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... UL LOW/TROUGH WILL DRIFT EASTWARD TONIGHT AND WED. THIS SYSTEM WILL BE REPLACED BY A STRONG MIDWEST RIDGE. RIDGE AXIS WILL REMAIN WELL WEST OF THE AREA, MEANING OUR UL FLOW WILL REMAIN OUT OF THE NW. THE FLOW, AND THE POSITION OF THE RIDGE, WILL BE CONDUCIVE FOR UL WAVES TO MOVE DOWN ACROSS THE UPPER OHIO VALLEY LATE WED AND THU. SOME OF THE MODEL RUNS ARE HINTING AT SOME ISO AFT ACTIVITY BREAKING OUT THU AFTERNOON. HOWEVER, MOISTURE IS LACKING, SO WILL LEAVE OUT MENTION ON THU. DO EXPECT AN INCREASE IN MID CLOUDS WED NIGHT THROUGH THU, AS THESE UL WAVES MOVE THROUGH. WED LOOKS LIKE ANOTHER BREEZY DAY, FOR THE REASONS THAT STRONGER WINDS WILL OCCUR ON TUESDAY. TEMPS WILL MODERATE THROUGHOUT THE SHORT TERM PERIOD. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... AS MENTIONED ABOVE...MEDIUM RANGE MODELS BUILD A FLAT RIDGE OVER THE REGION AS THE EAST COAST TROUGH FILLS WITH THE APPROACHING WEEKEND. THOSE MODELS DO MAINTAIN DIFFERENCES IN HEIGHT MAGNITUDE/TEMPERATURE PROFILES THOUGH. EITHER WAY...READINGS SHOULD REMAIN WELL ABOVE NORMAL FOR THE EXTENDED PERIOD AS HIGHS WERE FORECAST ABOUT 3 TO 5 DEGREES UNDER HPC GUIDANCE...BUT STILL ABOVE GFS NUMBERS. A SHORTWAVE TROUGH THAT IS FORECAST TO PUSH A WEAK COLD FRONT ACROSS THE FORECAST AREA LATE FRIDAY IS EXPECTED TO SUPPORT SCATTERED SHOWERS AND STORMS WITH ITS APPROACH AND PASSAGE. SLIGHT...TO CHANCE POPS WERE FORECAST INTO SATURDAY...AND DIMINISHED THEREAFTER ALTHOUGH SOUTHWARD PROGRESS OF THE BOUNDARY REMAINS QUESTIONABLE. && .AVIATION /17Z TUESDAY THROUGH SATURDAY/... VFR WILL CONTINUE THROUGH THE TAF PERIOD. NORTH SURFACE WINDS WILL GUST TO AROUND 25 KT...THEN DIMINISH AFTER 00Z. OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... GENERAL VFR IS EXPECTED TO CONTINUE...BUT AREAS OF MORNING FOG ARE POSSIBLE BY THE WEEKEND AS LOW LEVEL MOISTURE BEGINS TO INCREASE. SHOWER AND THUNDERSTORM CHANCES WILL ALSO INCREASE BY THE WEEKEND AS AN UPPER DISTURBANCE AND WEAK COLD FRONT CROSS THE REGION. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1111 AM EDT TUE JUN 26 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINTAIN A NORTHERLY FLOW OVER THE AREA WITH DRY AND COOL WEATHER THROUGH WEDNESDAY. WARMER TEMPERATURES CAN BE EXPECTED FOR THE LATTER HALF OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO MAKE ADJUSTMENTS TO INCREASE CLOUD COVERAGE AND TO MAKE SLIGHT TWEAKS ON TEMP AND DEW POINT BASED ON THE LATEST TRENDS. THE LATEST RUC ANALYSIS INDICATES A CLOSED UPPER LEVEL VORTEX CENTERED ACROSS NEW ENGLAND WITH DEEP MID-LEVEL RIDGING ACROSS THE CENTRAL PLAINS. THE UPPER OHIO VALLEY SITS BETWEEN THE TWO FEATURES, MORE INFLUENCED BY THE UPPER LOW, WITH A COOL NORTH- NORTHWESTERLY FLOW TODAY. AT THE SURFACE, A 1018MB HIGH IS CENTERED ACROSS LAKE MICHIGAN WITH A SURFACE LOW OVER MAINE. HIGH PRESSURE IS EXTENDING IN THE UPPER OHIO VALLEY, WITH A DEEP LAYER OF DRY AIR ABOVE 750MB. HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTHWEST TODAY, ALLOWING FOR ANOTHER DRY DAY. A TIGHTENED PRESSURE GRADIENT WITH DIURNAL MIXING WILL ALLOW FOR WINDS AT 10 TO 15 MPH TO GUST TO 25 MPH AT TIMES TODAY. DIURNAL CUMULUS WILL MAKE FOR PARTLY CLOUDY SKIES THROUGH MOST OF THE DAY, WITH CLOUD COVERAGE DIMINISHING BY SUNSET. TEMPS TODAY ARE GENERALLY 1-2 DEGREES ABOVE A MAV/MET BLEND, WITH HIGHS RANGING FROM THE UPPER 70S ACROSS PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV TO THE UPPER 60S ACROSS THE EASTERN RIDGES. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... UL LOW/TROUGH WILL DRIFT EASTWARD TONIGHT AND WED. THIS SYSTEM WILL BE REPLACED BY A STRONG MIDWEST RIDGE. RIDGE AXIS WILL REMAIN WELL WEST OF THE AREA, MEANING OUR UL FLOW WILL REMAIN OUT OF THE NW. THE FLOW, AND THE POSITION OF THE RIDGE, WILL BE CONDUCIVE FOR UL WAVES TO MOVE DOWN ACROSS THE UPPER OHIO VALLEY LATE WED AND THU. SOME OF THE MODEL RUNS ARE HINTING AT SOME ISO AFT ACTIVITY BREAKING OUT THU AFTERNOON. HOWEVER, MOISTURE IS LACKING, SO WILL LEAVE OUT MENTION ON THU. DO EXPECT AN INCREASE IN MID CLOUDS WED NIGHT THROUGH THU, AS THESE UL WAVES MOVE THROUGH. WED LOOKS LIKE ANOTHER BREEZY DAY, FOR THE REASONS THAT STRONGER WINDS WILL OCCUR ON TUESDAY. TEMPS WILL MODERATE THROUGHOUT THE SHORT TERM PERIOD. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS MENTIONED ABOVE...MEDIUM RANGE MODELS BUILD A FLAT RIDGE OVER THE REGION AS THE EAST COAST TROUGH FILLS WITH THE APPROACHING WEEKEND. THOSE MODELS DO MAINTAIN DIFFERENCES IN HEIGHT MAGNITUDE/TEMPERATURE PROFILES THOUGH. EITHER WAY...READINGS SHOULD REMAIN WELL ABOVE NORMAL FOR THE EXTENDED PERIOD AS HIGHS WERE FORECAST ABOUT 3 TO 5 DEGREES UNDER HPC GUIDANCE...BUT STILL ABOVE GFS NUMBERS. A SHORTWAVE TROUGH THAT IS FORECAST TO PUSH A WEAK COLD FRONT ACROSS THE FORECAST AREA LATE FRIDAY IS EXPECTED TO SUPPORT SCATTERED SHOWERS AND STORMS WITH ITS APPROACH AND PASSAGE. SLIGHT...TO CHANCE POPS WERE FORECAST INTO SATURDAY...AND DIMINISHED THEREAFTER ALTHOUGH SOUTHWARD PROGRESS OF THE BOUNDARY REMAINS QUESTIONABLE. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... VFR WILL CONTINUE THROUGH THE TAF PERIOD. SFC WIND WILL PICK UP AGAIN ON LATER THIS MORNING AND THROUGH THE AFTERNOON AS MIXING IMPROVES WITH THE HEATING. GIVEN THE EXPECTED DEEP MIXING LAYER, EXPECT GUSTS TO BE NEAR MONDAY`S SPEED, 18 TO 25 KTS. OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... GENERAL VFR IS EXPECTED TO CONTINUE...BUT AREAS OF MORNING FOG ARE POSSIBLE BY THE WEEKEND AS LOW LEVEL MOISTURE BEGINS TO INCREASE. SHOWER AND THUNDERSTORM CHANCES WL ALSO INCREASE BY THE WEEKEND AS AN UPPER DISTURBANCE AND WEAK COLD FRONT CROSS THE REGION. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1053 AM EDT TUE JUN 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE BUILDS INTO THE REGION THIS AFTERNOON THROUGH TONIGHT...THEN SETTLES ACROSS THE SOUTHEAST STATES WEDNESDAY. A STRONG UPPER LEVEL RIDGE BUILDS IN FROM THE WEST LATER IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... BRZY/COMFY WX HAS REPLACED THE WRM/HOT WX OF RECENT DAYS. RMNG (GENLY) SKC THROUGH THE REST OF THE DAY...W/ DEWPTS RMNG LO. HI TEMPS FM THE U70S TO ARND 80F...W/ NNW WNDS 10-20 MPH...GUSTS TO 25 TO 35 MPH (HIGHEST ERN PORTIONS). NOTE: TEAM DISPATCHED TO RIC AREA (AND IMMEDIATELY NW INVOF I64) TO CHECK OUT TSTM DAMAGE FM TUE AFTN. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... A COOL COMFORTABLE NIGHT IS EXPECTED TONIGHT UNDER A CLEAR SKY AS LOW TEMPERATURES DROP INTO THE MID TO UPPER 50S...AND PERHAPS LOW 50S OVER THE SW COUNTIES WHERE THE BEST NOCTURNAL BOUNDARY LAYER DECOUPLING SHOULD OCCUR. THESE VALUES WOULD BE AROUND 10F BELOW SEASONAL AVERAGES FOR LATE JUNE. HIGH PRESSURE SETTLES OVER THE SOUTHEAST WEDNESDAY AS THE STRONG MID/UPPER RIDGE OVER THE CENTRAL PLAINS BEGINS TO EXPAND EASTWARD. THIS WILL INITIATE A WARMING TREND...BUT ANOTHER SPECTACULAR DAY IS EXPECTED. HIGH TEMPERATURES SHOULD BE IN THE MID 80S UNDER A SUNNY SKY WITH AFTERNOON DEWPOINTS AROUND 50. THE MID/UPPER ANTICYCLONE FLATTENS AND SHIFTS TO THE MISSISSIPPI VALLEY WEDNESDAY NIGHT AND THURSDAY. PASSING HIGH CLOUDS ARE POSSIBLE IN THE NW FLOW ON THE NORTHERN PERIPHERY OF THE RIDGE...BUT THE SKY SHOULD LARGELY REMAIN MOSTLY CLEAR/SUNNY ACROSS THE LOCAL AREA. HIGH TEMPERATURES THURSDAY ARE EXPECTED TO RETURN TO THE LOW TO MID 90S...AFTER MORNING LOWS OF 60-65. DEWPOINTS ARE EXPECTED TO BE IN THE LOW 60S DURING PEAK HEATING...SO HEAT INDICES WILL BE SIMILAR TO THE AMBIENT TEMPERATURE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE BEGINNING OF THE LONG TERM PERIOD IS DOMINATED BY A FLAT RIDGE THAT BUILDS EASTWARD INTO THE MID ATLANTIC STATES. THIS WILL PROVIDE MOSTLY DRY WEATHER...BUT LOTS OF HEAT. EXPECT TO SEE TEMPERATURES CLIMB INTO THE UPPER 90S TO LOW 100S FRIDAY AND SATURDAY...WITH HEAT INDEX VALUES OF 100 TO 105 AS DEW POINTS FALL DURING PEAK MIXING TIMES IN THE AFTERNOON. A WEAK FRONTAL BOUNDARY MOVES THROUGH THE GREAT LAKE STATES THU INTO FRI...BEFORE STALLING NORTH OF THE REGION OVER THE WEEKEND. THE COMBINATION OF THE STALLED FRONT...THE LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES COULD PRODUCE SOME AFTERNOON AND EVENING CONVECTION...BUT EXPECT THAT WITH THE DRY AIR ASSOCIATED WITH THE RIDGE THAT THE STORMS WOULD BE ISOLATED. FOR SUNDAY INTO MONDAY...THE RIDGE BEGINS TO BREAK DOWN AND THE HEAT MAY BACK OFF A LITTLE...BUT THERE IS MORE UNCERTAINTY IN THIS PART OF THE FORECAST AS THE MODELS STRUGGLE TO HANDLE WHERE TS DEBBY WILL GO. FOR NOW HAVE ALLOWED A BIT MORE CLOUD COVER OVER THE SERN PART OF THE CWA BASED ON DEBBY HEADING THROUGH THE SW ATLANTIC LATE IN THE PERIOD. BUT WILL HAVE TO MONITOR OVER THE NEXT SEVERAL DAYS. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... NORTHERLY WINDS WILL BE GUSTY AT TIMES TODAY DURING THE LATE MORNING AND AFTN. WINDS DIMINISH TUESDAY EVENING. LOW DEW POINTS WILL PROMOTE VFR CONDS THROUGH THE PERIOD. OUTLOOK...MAINLY VFR AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. MVFR CONDS WILL BE PSBL DURG THE EARLY MRNG HOURS BY THIS WEEKEND. ALSO THERE WILL BE SLIGHT CHANCES FOR TSTMS DURING THE AFTN HOURS OVER THE WEEKEND. && .MARINE... NORTHERLY WINDS OF 20 TO 25 KTS OVER THE BAY AND COASTAL WATERS WILL DIMINISH SLOWLY DURING THE DAY TODAY. FOLLOWED CLOSE TO HRRR THIS MORNING AND WENT WITH HIGH SIDE OF GUIDANCE THROUGH THE AFTN. HAVE SCA ENDING BY 17Z EXCEPT CONTINUED TIL 20Z IN THE COASTAL WATERS SOUTH OF PARRAMORE ISLAND AND THE MOUTH OF THE BAY. SCA FOR THE COASTAL WATERS IS MOSTLY FOR 5 FOOT SEAS. WIND DIMINISH THIS EVENING AND THEN INCREASE WITH A SECONDARY NW SURGE EARLY WEDNESDAY MORNING. AT THIS POINT...IT APPEARS THAT THIS WILL REMAIN BELOW SCA CRITERIA. S/SW WINDS INCREASE TO AROUND 15 KNOTS FRIDAY AND SATURDAY OVER THE COASTAL WATERS AND SEAS MAY APPROACH 5 FT BUT KEEPING THEM AT 4 FT OR LESS AT THIS POINT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ630>633-635>638-650-652. SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634- 654-656-658. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...AJZ/ALB SHORT TERM...AJZ LONG TERM...ESS AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
706 AM EDT TUE JUN 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE BUILDS INTO THE REGION TODAY AND SETTLES ACROSS THE SOUTHEAST STATES WEDNESDAY. A STRONG UPPER LEVEL RIDGE BUILDS IN FROM THE WEST LATER IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE LATEST SURFACE INDICATES A 1019MB SURFACE HIGH CENTERED OVER LAKE MICHIGAN...WITH A 1001MB LOW PRESSURE CENTER NEAR NANTUCKET. A COLD FRONT EXTENDS SOUTHWESTWARD FROM THE LOW ACROSS THE ATLANTIC TOWARD CAPE HATTERAS AND THEN PARALLEL TO THE SOUTHEAST COAST. MEANWHILE...TS DEBBIE REMAINS OVER THE NE GULF OF MEXICO. MID-LEVEL NW FLOW WILL DRIVE THE SURFACE HIGH PRESSURE SYSTEM INTO THE OHIO VALLEY AND MID ATLANTIC TODAY WHILE LOW PRESSURE DEEPENS AND LIFTS NORTHWARD INTO ATLANTIC CANADA. THE AIRMASS ASSOCIATED WITH THIS HIGH WILL BE VERY PLEASANT FOR LATE JUNE. MAXIMUM TEMPERATURES ARE FORECAST TO RANGE FROM THE UPPER 70S ALONG THE COAST TO AROUND 80 INLAND...WITH DEWPOINTS IN THE MID TO UPPER 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... A COOL COMFORTABLE NIGHT IS EXPECTED TONIGHT UNDER A CLEAR SKY AS LOW TEMPERATURES DROP INTO THE MID TO UPPER 50S...AND PERHAPS LOW 50S OVER THE SW COUNTIES WHERE THE BEST NOCTURNAL BOUNDARY LAYER DECOUPLING SHOULD OCCUR. THESE VALUES WOULD BE AROUND 10F BELOW SEASONAL AVERAGES FOR LATE JUNE. HIGH PRESSURE SETTLES OVER THE SOUTHEAST WEDNESDAY AS THE STRONG MID/UPPER RIDGE OVER THE CENTRAL PLAINS BEGINS TO EXPAND EASTWARD. THIS WILL INITIATE A WARMING TREND...BUT ANOTHER SPECTACULAR DAY IS EXPECTED. HIGH TEMPERATURES SHOULD BE IN THE MID 80S UNDER A SUNNY SKY WITH AFTERNOON DEWPOINTS AROUND 50. THE MID/UPPER ANTICYCLONE FLATTENS AND SHIFTS TO THE MISSISSIPPI VALLEY WEDNESDAY NIGHT AND THURSDAY. PASSING HIGH CLOUDS ARE POSSIBLE IN THE NW FLOW ON THE NORTHERN PERIPHERY OF THE RIDGE...BUT THE SKY SHOULD LARGELY REMAIN MOSTLY CLEAR/SUNNY ACROSS THE LOCAL AREA. HIGH TEMPERATURES THURSDAY ARE EXPECTED TO RETURN TO THE LOW TO MID 90S...AFTER MORNING LOWS OF 60-65. DEWPOINTS ARE EXPECTED TO BE IN THE LOW 60S DURING PEAK HEATING...SO HEAT INDICES WILL BE SIMILAR TO THE AMBIENT TEMPERATURE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE BEGINNING OF THE LONG TERM PERIOD IS DOMINATED BY A FLAT RIDGE THAT BUILDS EASTWARD INTO THE MID ATLANTIC STATES. THIS WILL PROVIDE MOSTLY DRY WEATHER...BUT LOTS OF HEAT. EXPECT TO SEE TEMPERATURES CLIMB INTO THE UPPER 90S TO LOW 100S FRIDAY AND SATURDAY...WITH HEAT INDEX VALUES OF 100 TO 105 AS DEW POINTS FALL DURING PEAK MIXING TIMES IN THE AFTERNOON. A WEAK FRONTAL BOUNDARY MOVES THROUGH THE GREAT LAKE STATES THU INTO FRI...BEFORE STALLING NORTH OF THE REGION OVER THE WEEKEND. THE COMBINATION OF THE STALLED FRONT...THE LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES COULD PRODUCE SOME AFTERNOON AND EVENING CONVECTION...BUT EXPECT THAT WITH THE DRY AIR ASSOCIATED WITH THE RIDGE THAT THE STORMS WOULD BE ISOLATED. FOR SUNDAY INTO MONDAY...THE RIDGE BEGINS TO BREAK DOWN AND THE HEAT MAY BACK OFF A LITTLE...BUT THERE IS MORE UNCERTAINTY IN THIS PART OF THE FORECAST AS THE MODELS STRUGGLE TO HANDLE WHERE TS DEBBY WILL GO. FOR NOW HAVE ALLOWED A BIT MORE CLOUD COVER OVER THE SERN PART OF THE CWA BASED ON DEBBY HEADING THROUGH THE SW ATLANTIC LATE IN THE PERIOD. BUT WILL HAVE TO MONITOR OVER THE NEXT SEVERAL DAYS. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... NORTHERLY WINDS WILL BE GUSTY AT TIMES TODAY DURING THE LATE MORNING AND AFTN. WINDS DIMINISH TUESDAY EVENING. LOW DEW POINTS WILL PROMOTE VFR CONDS THROUGH THE PERIOD. OUTLOOK...MAINLY VFR AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. MVFR CONDS WILL BE PSBL DURG THE EARLY MRNG HOURS BY THIS WEEKEND. ALSO THERE WILL BE SLIGHT CHANCES FOR TSTMS DURING THE AFTN HOURS OVER THE WEEKEND. && .MARINE... NORTHERLY WINDS OF 20 TO 25 KTS OVER THE BAY AND COASTAL WATERS WILL DIMINISH SLOWLY DURING THE DAY TODAY. FOLLOWED CLOSE TO HRRR THIS MORNING AND WENT WITH HIGH SIDE OF GUIDANCE THROUGH THE AFTN. HAVE SCA ENDING BY 17Z EXCEPT CONTINUED TIL 20Z IN THE COASTAL WATERS SOUTH OF PARRAMORE ISLAND AND THE MOUTH OF THE BAY. SCA FOR THE COASTAL WATERS IS MOSTLY FOR 5 FOOT SEAS. WIND DIMINISH THIS EVENING AND THEN INCREASE WITH A SECONDARY NW SURGE EARLY WEDNESDAY MORNING. AT THIS POINT...IT APPEARS THAT THIS WILL REMAIN BELOW SCA CRITERIA. S/SW WINDS INCREASE TO AROUND 15 KNOTS FRIDAY AND SATURDAY OVER THE COASTAL WATERS AND SEAS MAY APPROACH 5 FT BUT KEEPING THEM AT 4 FT OR LESS AT THIS POINT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ630>633-635>638-650-652. SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634- 654-656-658. && $$ SYNOPSIS...AJZ NEAR TERM...AJZ SHORT TERM...AJZ LONG TERM...ESS AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
408 AM EDT TUE JUN 26 2012 .SYNOPSIS... CANADIAN HIGH PRESSURE BUILDS INTO THE REGION TODAY AND SETTLES ACROSS THE SOUTHEAST STATES WEDNESDAY. A STRONG UPPER LEVEL RIDGE BUILDS IN FROM THE WEST LATER IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE LATEST SURFACE INDICATES A 1019MB SURFACE HIGH CENTERED OVER LAKE MICHIGAN...WITH A 1001MB LOW PRESSURE CENTER NEAR NANTUCKET. A COLD FRONT EXTENDS SOUTHWESTWARD FROM THE LOW ACROSS THE ATLANTIC TOWARD CAPE HATTERAS AND THEN PARALLEL TO THE SOUTHEAST COAST. MEANWHILE...TS DEBBIE REMAINS OVER THE NE GULF OF MEXICO. MID-LEVEL NW FLOW WILL DRIVE THE SURFACE HIGH PRESSURE SYSTEM INTO THE OHIO VALLEY AND MID ATLANTIC TODAY WHILE LOW PRESSURE DEEPENS AND LIFTS NORTHWARD INTO ATLANTIC CANADA. THE AIRMASS ASSOCIATED WITH THIS HIGH WILL BE VERY PLEASANT FOR LATE JUNE. MAXIMUM TEMPERATURES ARE FORECAST TO RANGE FROM THE UPPER 70S ALONG THE COAST TO AROUND 80 INLAND...WITH DEWPOINTS IN THE MID TO UPPER 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... A COOL COMFORTABLE NIGHT IS EXPECTED TONIGHT UNDER A CLEAR SKY AS LOW TEMPERATURES DROP INTO THE MID TO UPPER 50S...AND PERHAPS LOW 50S OVER THE SW COUNTIES WHERE THE BEST NOCTURNAL BOUNDARY LAYER DECOUPLING SHOULD OCCUR. THESE VALUES WOULD BE AROUND 10F BELOW SEASONAL AVERAGES FOR LATE JUNE. HIGH PRESSURE SETTLES OVER THE SOUTHEAST WEDNESDAY AS THE STRONG MID/UPPER RIDGE OVER THE CENTRAL PLAINS BEGINS TO EXPAND EASTWARD. THIS WILL INITIATE A WARMING TREND...BUT ANOTHER SPECTACULAR DAY IS EXPECTED. HIGH TEMPERATURES SHOULD BE IN THE MID 80S UNDER A SUNNY SKY WITH AFTERNOON DEWPOINTS AROUND 50. THE MID/UPPER ANTICYCLONE FLATTENS AND SHIFTS TO THE MISSISSIPPI VALLEY WEDNESDAY NIGHT AND THURSDAY. PASSING HIGH CLOUDS ARE POSSIBLE IN THE NW FLOW ON THE NORTHERN PERIPHERY OF THE RIDGE...BUT THE SKY SHOULD LARGELY REMAIN MOSTLY CLEAR/SUNNY ACROSS THE LOCAL AREA. HIGH TEMPERATURES THURSDAY ARE EXPECTED TO RETURN TO THE LOW TO MID 90S...AFTER MORNING LOWS OF 60-65. DEWPOINTS ARE EXPECTED TO BE IN THE LOW 60S DURING PEAK HEATING...SO HEAT INDICES WILL BE SIMILAR TO THE AMBIENT TEMPERATURE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE BEGINNING OF THE LONG TERM PERIOD IS DOMINATED BY A FLAT RIDGE THAT BUILDS EASTWARD INTO THE MID ATLANTIC STATES. THIS WILL PROVIDE MOSTLY DRY WEATHER...BUT LOTS OF HEAT. EXPECT TO SEE TEMPERATURES CLIMB INTO THE UPPER 90S TO LOW 100S FRIDAY AND SATURDAY...WITH HEAT INDEX VALUES OF 100 TO 105 AS DEW POINTS FALL DURING PEAK MIXING TIMES IN THE AFTERNOON. A WEAK FRONTAL BOUNDARY MOVES THROUGH THE GREAT LAKE STATES THU INTO FRI...BEFORE STALLING NORTH OF THE REGION OVER THE WEEKEND. THE COMBINATION OF THE STALLED FRONT...THE LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES COULD PRODUCE SOME AFTERNOON AND EVENING CONVECTION...BUT EXPECT THAT WITH THE DRY AIR ASSOCIATED WITH THE RIDGE THAT THE STORMS WOULD BE ISOLATED. FOR SUNDAY INTO MONDAY...THE RIDGE BEGINS TO BREAK DOWN AND THE HEAT MAY BACK OFF A LITTLE...BUT THERE IS MORE UNCERTAINTY IN THIS PART OF THE FORECAST AS THE MODELS STRUGGLE TO HANDLE WHERE TS DEBBY WILL GO. FOR NOW HAVE ALLOWED A BIT MORE CLOUD COVER OVER THE SERN PART OF THE CWA BASED ON DEBBY HEADING THROUGH THE SW ATLANTIC LATE IN THE PERIOD. BUT WILL HAVE TO MONITOR OVER THE NEXT SEVERAL DAYS. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... AS OF 05Z...COLD FRONT NEAR THE VA/NC BORDER WILL MOVE THROUGH ECG BY 08Z. SHOWERS ARE WELL TO THE SOUTH. WINDS WILL CONTINUE FROM THE NORTH THROUGH THE DAY TUESDAY BECOMING GUSTY AT TIMES DURING LATE MORNING AND AFTN. WINDS DIMINISH TUESDAY EVENING. LOW (OR LOWERING AT ECG) DEW POINTS WILL PROMOTE VFR CONDS THROUGH THE PERIOD. OUTLOOK...MAINLY VFR AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. MVFR CONDS WILL BE PSBL DURG THE EARLY MRNG HOURS BY THIS WEEKEND. && .MARINE... NORTHERLY WINDS OF 20 TO 25 KTS OVER THE BAY AND COASTAL WATERS WILL DIMINISH SLOWLY DURING THE DAY TODAY. FOLLOWED CLOSE TO HRRR THIS MORNING AND WENT WITH HIGH SIDE OF GUIDANCE THROUGH THE AFTN. HAVE SCA ENDING BY 17Z EXCEPT CONTINUED TIL 20Z IN THE COASTAL WATERS SOUTH OF PARRAMORE ISLAND AND THE MOUTH OF THE BAY. SCA FOR THE COASTAL WATERS IS MOSTLY FOR 5 FOOT SEAS. WIND DIMINISH THIS EVENING AND THEN INCREASE WITH A SECONDARY NW SURGE EARLY WEDNESDAY MORNING. AT THIS POINT...IT APPEARS THAT THIS WILL REMAIN BELOW SCA CRITERIA. S/SW WINDS INCREASE TO AROUND 15 KNOTS FRIDAY AND SATURDAY OVER THE COASTAL WATERS AND SEAS MAY APPROACH 5 FT BUT KEEPING THEM AT 4 FT OR LESS AT THIS POINT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ630>633-635>638-650-652. SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634- 654-656-658. && $$ SYNOPSIS...AJZ NEAR TERM...AJZ SHORT TERM...AJZ LONG TERM...ESS AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
114 PM EDT TUE JUN 26 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 354 AM EDT TUE JUN 26 2012 00Z RAOBS/LATEST RUC ANALYSIS AND WV IMAGERY SHOWS NW FLOW ALF OVER THE UPR LKS BTWN HI AMPLITUDE RDG IN THE PLAINS AND DEEP TROF OVER QUEBEC/NE CONUS. A SHRTWV IS DROPPING SEWD THRU ONTARIO IN THIS NW FLOW ALF. ALTHOUGH THERE IS QUITE A BIT OF ASSOCIATED CLD COVER OVER ONTARIO INTO ERN LK SUP WHICH IS ON TRACK TO IMPACT THE ERN CWA... MOST OF THIS CLD IS OF THE MID/HI VARIETY PER DRYNESS OF THE LLVLS SHOWN ON THE 00Z YPL RAOB. OTRW...WITH SFC HI PRES SITUATED OVER NE WI...SKIES ARE MOCLR OVER THE W HALF. MORE CLD/SOME SHRA/TS ARE IMPACTING THE NRN PLAINS IN ADVANCE OF H85 WARM FNT DESPITE PRESENCE OF IMPRESSIVE CAP SHOWN ON THE 00Z BISMARCK/ABERDEEN RAOBS THAT IS ON THE NRN EDGE OF VERY WARM AIRMASS IN THE CENTRAL PLAINS. TODAY...UPR RDG TO THE W WL MOVE SLOWLY TO THE E...WITH SFC HI PRES SINKING SLOWLY S INTO THE LWR LKS/OH RIVER VALLEY BY 00Z WED. EXPECT AREA OF MID/HI CLD ASSOCIATED WITH SHRTWV IN ONTARIO TO IMPACT MAINLY THE ERN CWA THIS MRNG. MORE HI CLD RELATED TO ISENTROPIC LIFT IN ADVANCE OF H85 WARM FNT IN THE PLAINS WL ALSO STREAM OVER THE RDG INTO THE CWA THIS AFTN...BUT OVERALL THE DAY WL TURN OUT MOSUNNY WITH LARGER SCALE SUBSIDENCE MAINTAINING DRY AIRMASS. FCST H85 TEMPS CLIMBING TO 14-15C AND MIXING TO H825 ON GFS/NAM FCST SDNGS YIELDS HI TEMPS REACHING 80-85 AWAY FM LK MODERATION...WHICH WL BE MAXIMIZED NEAR LK MI IN THE H925 SW FLOW. BUT MAJORITY OF MODELS INDICATE A WEAKER LK BREEZE WL FORM OFF LK SUP AS WELL AND BRING SOME LOCAL COOLING TO SHORE COMMUNITIES. TNGT...WITH STRENGTHENING SW H925 FLOW LIFTING H85 TEMPS TOWARD 20C BY 12Z WED NEAR THE WI BORDER AS WELL AS INCRSG PWAT TOWARD 1 INCH OVER THE E TO 1.5 INCH OVER THE W...EXPECT A MUCH WARMER NGT. TEMPS WL BE HIEST OVER THE W HALF IN THE DOWNSLOPE AREAS NEAR LK SUP. THE COOLEST TEMPS WL BE OVER THE INTERIOR E CLOSER TO SOMEWHAT WEAKER PRES GRADIENT. DESPITE THE INCRSG ABSOLUTE MSTR...THE AIRMASS WL SO WARM THE RH WL BE TOO LO FOR ANY PCPN. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 354 AM EDT TUE JUN 26 2012 MODELS REMAIN IN GOOD AGREEMENT IN IN OVERALL LARGE SCALE PATTERN THROUGH NEXT WEEKEND. BROAD 595 H5 RIDGE THAT PRODUCED ANOTHER DAY OF RECORD TRIPLE-DIGIT HEAT OVER PORTIONS OF THE SOUTHERN PLAINS ON MONDAY IS FCST TO EXPAND INTO THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES BY WEDNESDAY. CORE OF WARMEST AIR /H85 TEMPS AOA +24C/ REMAINS SOUTH OF UPR LAKES...BUT WILL STILL HAVE WELL ABOVE NORMAL TEMPS OVR UPR MICHIGAN WEDNESDAY/THURSDAY AND PROBABLY FRIDAY AS WELL. SLIGHT COOLING IS FCST FOR THE WEEKEND AS LARGER SCALE HEIGHT FALLS DEVELOP IN RESPONSE TO UPPER LOW SLIDING ACROSS ONTARIO AND QUEBEC AND INTO AT LEAST NORTHERN PORTION OF GREAT LAKES. ON WEDNESDAY...SEEMS THERE IS STILL A SMALL RISK OF INCREASED MID CLOUDS AND PERHAPS A SHRA/TSRA WORKING ACROSS CWA ON NOSE OF H85 MOISTURE TRANSPORT. GFS LOOKS LIKE ECMWF DID A FEW NIGHTS AGO SHOWING GOOD SIGNAL WITH THE MOISTURE TRANSPORT FOR PRECIP. MORE RECENT RUNS OF ECMWF ALONG WITH CANADIAN KEEP IT DRY. GIVEN UNCERTAINTY OPTED TO JUST BUMP SKY UP FOR NOW AND KEEP FCST DRY. MINIMAL DEEPER MOISTURE PER FCST SOUNDINGS FM GFS WOULD LEAD TO SPRINKLES IF SOMETHING DID WORK ACROSS UPR MICHIGAN. IF MID CLOUDS ARE AROUND...H85-H7 MOISTURE TRANSPORT FCST WOULD POINT TO THEM EVADING BY EARLY AFTN. H85 TEMPS HAVE STEADILY TRENDED WARMER THE LAST FEW DAYS FOR WEDNESDAY. NOW APPEARS THAT SOLID +20C H85 TEMPS ARE AROUND IN THE AFTN. CONTINUED TREND OF INCREASING HIGHS WITH MANY AREAS TOPPING OUT IN THE MID-UPR 80S. GIVEN TRENDS WOULD NOT BE SHOCKED TO SEE LOWER 90S IN DOWNSLOPE AREAS OF SCNTRL CWA WITH WSW BLYR FLOW FCST. HUMIDITY WILL BE ON THE RISE AS SWATH OF H85 DWPNTS WELL ABOVE +10C PLOWS ACROSS RESULTING IN SFC DWPNTS SURGING INTO THE LOWER 60S FOR MAJORITY OF CWA IN THE AFTN. WEDNESDAY SHAPING UP TO BE THE MOST UNCOMFORTABLE DAY OF THE WEEK. ATTN ON WEDNESDAY AFTN WILL BE OVER NORTHERN PLAINS INTO MINNESOTA TO SEE WHAT IF ANY CONVECTION DEVELOPS WITH AMPLE INSTABILITY BUT VERY STOUT MID-LEVEL CAPPING AS H7 TEMPS ARE FCST WELL INTO THE TEENS. EDGE OF MUCAPE GRADIENT SUGGESTS MOST CONVECTION WILL STAY MAINLY IN THE NORTHERN PLAINS AND THEN DEFLECT INTO CANADA ON EDGE OF MID-LEVEL RIDGE. AFTER THAT IT IS UNCERTAIN HOW MUCH IF ANY CONVECTION WILL WORK BACK INTO UPR LAKES LATER WEDNESDAY NIGHT INTO THURSDAY MORNING. CAPPING OVR THE PLAINS WILL BE FIRMLY OVERHEAD AT THAT TIME WITH H7 TEMPS OVR UPR MICHIGAN 12Z THURSDAY OF +14C TO +16C. SOME HINTS AT MID-LEVEL MOISTURE TRANSPORT THAT MAY TRY TO TAKE ADVANTAGE OF ELEVATED INSTABILITY...BUT GIVEN THE CAPPING MAY BE HARD PRESSED TO SEE ANY CONVECTION. MODELS HAVE BEEN DIFFERING ON HOW QUICK TO BRING SFC FRONT THROUGH AREA ON THURSDAY BUT NOW SEEM TO BE IN FAVOR OF IDEA THAT BRINGS FRONT INTO WESTERN UPR MICHIGAN AROUND DAYBREAK ON THURSDAY AND INTO SCNTRL AND EAST CWA THURSDAY AFTN. CONVERGENCE ALONG FRONT IS WEAK AND THERE IS REALLY NOT MUCH CHANGE IN CAPPING. ALSO...H85-H7 MOISTURE TRANSPORT IS QUICKLY SHUNTED MORE SOUTH AND EAST OF UPR MICHIGAN AS H85 WINDS VEER MORE NORTHWEST IN THE MORNING. IF CONVECTION COULD DEVELOP /THINK THIS IS A PRETTY BIG QUESTION GIVEN STRENGTH OF CAPPING/ THEN SEVERE STORMS WOULD CERTAINLY BE POSSIBLE OVR SOUTH WITH 0-6KM SHEAR OVR 40 KTS AND MUCAPE OVR 2000-3000 J/KG. HAVE KEPT SLIGHT CHANCES IN FCST...BUT NO MORE AT THIS POINT WITH EXPECTED CAPPING. DEEP MIXING MAY LOWER DWPNTS/HUMIDITY VALUES SIGNIFICANTLY LATE IN THE DAY ON THURSDAY OVR WESTERN INTERIOR. KNOCKED DWPTS DOWN FURTHER /LOWER 50S/ BUT DID NOT GO NEAR AS LOW AS MIXED DWPNT TOOL GAVE. LATER SHIFTS WILL HAVE TO MONITOR TRENDS FOR DWPNTS/RH VALUES LATE THURSDAY. LOOKS QUIET IN THE WAKE OF THE FRONT ON FRIDAY. WEST WINDS ON KEWEENAW MAY GUST OVR 30 MPH...AND THIS IS WHERE THE MOST COOLING WILL BE REALIZED BEHIND THE FRONT. OTHERWISE...INCREASED TEMPS ON FRIDAY AS UPPER TROUGH REALLY HAS NOT FULLY ARRIVED BY THAT TIME AND H85 TEMPS ARE STILL WARM IN THE MIDDLE TEENS. SEE NO REASON WHY MANY LOCATIONS WILL NOT CRACK 80 DEGREES YET AGAIN...WITH MID-UPR 80S POSSIBLE SOUTH CNTRL. LATEST ECMWF CONTINUES TO SHOW +21C H85 TEMPS SUPPORTING MAXES AROUND 90 DEGREES OVR MUCH OF CNTRL. DEFINITELY SEEMS LIKE MODELS ARE BACKING AWAY FM THE COOLING THEY WERE SHOWING EARLIER FOR FRIDAY. DOES LOOK A BIT COOLER FOR THE WEEKEND AS LARGER SCALE HEIGHTS FALL SOME WITH UPR LOW SETTLING ACROSS ONTARIO/QUEBEC. EVEN SO...MAX TEMPS BOTH SATURDAY AND MAYBE SUNDAY STILL PUSH PAST 80 DEGREES OVR CWA AWAY FM FLOW OFF LK SUPERIOR. GFS CONTINUES TO SHOW STRONGER SHORTWAVE/ELEVATED MID-LEVEL LAPSE RATES SLIDING THROUGH SATURDAY NIGHT INTO SUNDAY MORNING IN THE BROAD NW FLOW PATTERN ALOFT. CONSENSUS GAVE LOWER CHANCE POPS MAINLY ON SATURDAY NIGHT AND GENERALLY RAN WITH THAT IDEA AS DIFFERENT RUNS OF DIFFERENT MODELS HAVE BEEN HINTING AT THIS FOR A FEW DAYS NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 114 PM EDT TUE JUN 26 2012 A HIGH PRESSURE RIDGE ACROSS EASTERN UPPER MI WILL RESULT IN VFR CONDITIONS THROUGHOUT THE FORECAST PERIOD. LAKE BREEZES HAVE ALREADY DEVELOPED EARLY THIS AFTERNOON WHERE THE PRESSURE GRADIENT IS WEAKER CLOSER TO THE RIDGE AXIS. EXPECT THEM TO PUSH THROUGH CMX AROUND 20Z AND SAW AROUND 21Z. THE LAKE BREEZE NEAR IWD SHOULD REMAIN PINNED TO THE SHORELINE WITH STRONGER SOUTH WINDS. WEAK LLWS WILL DEVELOP AT IWD TONIGHT AS THE PRESSURE GRADIENT STRENGTHENS AHEAD OF AN APPROACHING SYSTEM FROM THE WEST. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 354 AM EDT TUE JUN 26 2012 WITH RELATIVELY WEAK PRES GRADIENT AND HI STABILITY OVER THE COOL LAKE WATERS...EXPECT WINDS UNDER 20 KTS THROUGH THE FORECAST PERIOD. THE ONLY EXCEPTION WL BE ON THU INTO EARLY FRI...WHEN STRONGER WINDS UP TO 25 KTS ASSOCIATED WITH THE PASSAGE OF A LOW PRESSURE TROUGH MIGHT IMPACT MAINLY THE NCENTRAL LAKE. A MOISTER AIRMASS THAT ARRIVES AHEAD OF THIS TROF MAY ALSO CAUSE SOME PATCHY FOG ON WED NIGHT INTO THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...TK MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
724 AM EDT TUE JUN 26 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 354 AM EDT TUE JUN 26 2012 00Z RAOBS/LATEST RUC ANALYSIS AND WV IMAGERY SHOWS NW FLOW ALF OVER THE UPR LKS BTWN HI AMPLITUDE RDG IN THE PLAINS AND DEEP TROF OVER QUEBEC/NE CONUS. A SHRTWV IS DROPPING SEWD THRU ONTARIO IN THIS NW FLOW ALF. ALTHOUGH THERE IS QUITE A BIT OF ASSOCIATED CLD COVER OVER ONTARIO INTO ERN LK SUP WHICH IS ON TRACK TO IMPACT THE ERN CWA... MOST OF THIS CLD IS OF THE MID/HI VARIETY PER DRYNESS OF THE LLVLS SHOWN ON THE 00Z YPL RAOB. OTRW...WITH SFC HI PRES SITUATED OVER NE WI...SKIES ARE MOCLR OVER THE W HALF. MORE CLD/SOME SHRA/TS ARE IMPACTING THE NRN PLAINS IN ADVANCE OF H85 WARM FNT DESPITE PRESENCE OF IMPRESSIVE CAP SHOWN ON THE 00Z BISMARCK/ABERDEEN RAOBS THAT IS ON THE NRN EDGE OF VERY WARM AIRMASS IN THE CENTRAL PLAINS. TODAY...UPR RDG TO THE W WL MOVE SLOWLY TO THE E...WITH SFC HI PRES SINKING SLOWLY S INTO THE LWR LKS/OH RIVER VALLEY BY 00Z WED. EXPECT AREA OF MID/HI CLD ASSOCIATED WITH SHRTWV IN ONTARIO TO IMPACT MAINLY THE ERN CWA THIS MRNG. MORE HI CLD RELATED TO ISENTROPIC LIFT IN ADVANCE OF H85 WARM FNT IN THE PLAINS WL ALSO STREAM OVER THE RDG INTO THE CWA THIS AFTN...BUT OVERALL THE DAY WL TURN OUT MOSUNNY WITH LARGER SCALE SUBSIDENCE MAINTAINING DRY AIRMASS. FCST H85 TEMPS CLIMBING TO 14-15C AND MIXING TO H825 ON GFS/NAM FCST SDNGS YIELDS HI TEMPS REACHING 80-85 AWAY FM LK MODERATION...WHICH WL BE MAXIMIZED NEAR LK MI IN THE H925 SW FLOW. BUT MAJORITY OF MODELS INDICATE A WEAKER LK BREEZE WL FORM OFF LK SUP AS WELL AND BRING SOME LOCAL COOLING TO SHORE COMMUNITIES. TNGT...WITH STRENGTHENING SW H925 FLOW LIFTING H85 TEMPS TOWARD 20C BY 12Z WED NEAR THE WI BORDER AS WELL AS INCRSG PWAT TOWARD 1 INCH OVER THE E TO 1.5 INCH OVER THE W...EXPECT A MUCH WARMER NGT. TEMPS WL BE HIEST OVER THE W HALF IN THE DOWNSLOPE AREAS NEAR LK SUP. THE COOLEST TEMPS WL BE OVER THE INTERIOR E CLOSER TO SOMEWHAT WEAKER PRES GRADIENT. DESPITE THE INCRSG ABSOLUTE MSTR...THE AIRMASS WL SO WARM THE RH WL BE TOO LO FOR ANY PCPN. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 354 AM EDT TUE JUN 26 2012 MODELS REMAIN IN GOOD AGREEMENT IN IN OVERALL LARGE SCALE PATTERN THROUGH NEXT WEEKEND. BROAD 595 H5 RIDGE THAT PRODUCED ANOTHER DAY OF RECORD TRIPLE-DIGIT HEAT OVER PORTIONS OF THE SOUTHERN PLAINS ON MONDAY IS FCST TO EXPAND INTO THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES BY WEDNESDAY. CORE OF WARMEST AIR /H85 TEMPS AOA +24C/ REMAINS SOUTH OF UPR LAKES...BUT WILL STILL HAVE WELL ABOVE NORMAL TEMPS OVR UPR MICHIGAN WEDNESDAY/THURSDAY AND PROBABLY FRIDAY AS WELL. SLIGHT COOLING IS FCST FOR THE WEEKEND AS LARGER SCALE HEIGHT FALLS DEVELOP IN RESPONSE TO UPPER LOW SLIDING ACROSS ONTARIO AND QUEBEC AND INTO AT LEAST NORTHERN PORTION OF GREAT LAKES. ON WEDNESDAY...SEEMS THERE IS STILL A SMALL RISK OF INCREASED MID CLOUDS AND PERHAPS A SHRA/TSRA WORKING ACROSS CWA ON NOSE OF H85 MOISTURE TRANSPORT. GFS LOOKS LIKE ECMWF DID A FEW NIGHTS AGO SHOWING GOOD SIGNAL WITH THE MOISTURE TRANSPORT FOR PRECIP. MORE RECENT RUNS OF ECMWF ALONG WITH CANADIAN KEEP IT DRY. GIVEN UNCERTAINTY OPTED TO JUST BUMP SKY UP FOR NOW AND KEEP FCST DRY. MINIMAL DEEPER MOISTURE PER FCST SOUNDINGS FM GFS WOULD LEAD TO SPRINKLES IF SOMETHING DID WORK ACROSS UPR MICHIGAN. IF MID CLOUDS ARE AROUND...H85-H7 MOISTURE TRANSPORT FCST WOULD POINT TO THEM EVADING BY EARLY AFTN. H85 TEMPS HAVE STEADILY TRENDED WARMER THE LAST FEW DAYS FOR WEDNESDAY. NOW APPEARS THAT SOLID +20C H85 TEMPS ARE AROUND IN THE AFTN. CONTINUED TREND OF INCREASING HIGHS WITH MANY AREAS TOPPING OUT IN THE MID-UPR 80S. GIVEN TRENDS WOULD NOT BE SHOCKED TO SEE LOWER 90S IN DOWNSLOPE AREAS OF SCNTRL CWA WITH WSW BLYR FLOW FCST. HUMIDITY WILL BE ON THE RISE AS SWATH OF H85 DWPNTS WELL ABOVE +10C PLOWS ACROSS RESULTING IN SFC DWPNTS SURGING INTO THE LOWER 60S FOR MAJORITY OF CWA IN THE AFTN. WEDNESDAY SHAPING UP TO BE THE MOST UNCOMFORTABLE DAY OF THE WEEK. ATTN ON WEDNESDAY AFTN WILL BE OVER NORTHERN PLAINS INTO MINNESOTA TO SEE WHAT IF ANY CONVECTION DEVELOPS WITH AMPLE INSTABILITY BUT VERY STOUT MID-LEVEL CAPPING AS H7 TEMPS ARE FCST WELL INTO THE TEENS. EDGE OF MUCAPE GRADIENT SUGGESTS MOST CONVECTION WILL STAY MAINLY IN THE NORTHERN PLAINS AND THEN DEFLECT INTO CANADA ON EDGE OF MID-LEVEL RIDGE. AFTER THAT IT IS UNCERTAIN HOW MUCH IF ANY CONVECTION WILL WORK BACK INTO UPR LAKES LATER WEDNESDAY NIGHT INTO THURSDAY MORNING. CAPPING OVR THE PLAINS WILL BE FIRMLY OVERHEAD AT THAT TIME WITH H7 TEMPS OVR UPR MICHIGAN 12Z THURSDAY OF +14C TO +16C. SOME HINTS AT MID-LEVEL MOISTURE TRANSPORT THAT MAY TRY TO TAKE ADVANTAGE OF ELEVATED INSTABILITY...BUT GIVEN THE CAPPING MAY BE HARD PRESSED TO SEE ANY CONVECTION. MODELS HAVE BEEN DIFFERING ON HOW QUICK TO BRING SFC FRONT THROUGH AREA ON THURSDAY BUT NOW SEEM TO BE IN FAVOR OF IDEA THAT BRINGS FRONT INTO WESTERN UPR MICHIGAN AROUND DAYBREAK ON THURSDAY AND INTO SCNTRL AND EAST CWA THURSDAY AFTN. CONVERGENCE ALONG FRONT IS WEAK AND THERE IS REALLY NOT MUCH CHANGE IN CAPPING. ALSO...H85-H7 MOISTURE TRANSPORT IS QUICKLY SHUNTED MORE SOUTH AND EAST OF UPR MICHIGAN AS H85 WINDS VEER MORE NORTHWEST IN THE MORNING. IF CONVECTION COULD DEVELOP /THINK THIS IS A PRETTY BIG QUESTION GIVEN STRENGTH OF CAPPING/ THEN SEVERE STORMS WOULD CERTAINLY BE POSSIBLE OVR SOUTH WITH 0-6KM SHEAR OVR 40 KTS AND MUCAPE OVR 2000-3000 J/KG. HAVE KEPT SLIGHT CHANCES IN FCST...BUT NO MORE AT THIS POINT WITH EXPECTED CAPPING. DEEP MIXING MAY LOWER DWPNTS/HUMIDITY VALUES SIGNIFICANTLY LATE IN THE DAY ON THURSDAY OVR WESTERN INTERIOR. KNOCKED DWPTS DOWN FURTHER /LOWER 50S/ BUT DID NOT GO NEAR AS LOW AS MIXED DWPNT TOOL GAVE. LATER SHIFTS WILL HAVE TO MONITOR TRENDS FOR DWPNTS/RH VALUES LATE THURSDAY. LOOKS QUIET IN THE WAKE OF THE FRONT ON FRIDAY. WEST WINDS ON KEWEENAW MAY GUST OVR 30 MPH...AND THIS IS WHERE THE MOST COOLING WILL BE REALIZED BEHIND THE FRONT. OTHERWISE...INCREASED TEMPS ON FRIDAY AS UPPER TROUGH REALLY HAS NOT FULLY ARRIVED BY THAT TIME AND H85 TEMPS ARE STILL WARM IN THE MIDDLE TEENS. SEE NO REASON WHY MANY LOCATIONS WILL NOT CRACK 80 DEGREES YET AGAIN...WITH MID-UPR 80S POSSIBLE SOUTH CNTRL. LATEST ECMWF CONTINUES TO SHOW +21C H85 TEMPS SUPPORTING MAXES AROUND 90 DEGREES OVR MUCH OF CNTRL. DEFINITELY SEEMS LIKE MODELS ARE BACKING AWAY FM THE COOLING THEY WERE SHOWING EARLIER FOR FRIDAY. DOES LOOK A BIT COOLER FOR THE WEEKEND AS LARGER SCALE HEIGHTS FALL SOME WITH UPR LOW SETTLING ACROSS ONTARIO/QUEBEC. EVEN SO...MAX TEMPS BOTH SATURDAY AND MAYBE SUNDAY STILL PUSH PAST 80 DEGREES OVR CWA AWAY FM FLOW OFF LK SUPERIOR. GFS CONTINUES TO SHOW STRONGER SHORTWAVE/ELEVATED MID-LEVEL LAPSE RATES SLIDING THROUGH SATURDAY NIGHT INTO SUNDAY MORNING IN THE BROAD NW FLOW PATTERN ALOFT. CONSENSUS GAVE LOWER CHANCE POPS MAINLY ON SATURDAY NIGHT AND GENERALLY RAN WITH THAT IDEA AS DIFFERENT RUNS OF DIFFERENT MODELS HAVE BEEN HINTING AT THIS FOR A FEW DAYS NOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 724 AM EDT TUE JUN 26 2012 PLAN ON VFR CONDITIONS TO CONTINUE THIS FCST PERIOD WITH DRY HI PRES DOMINATING. WINDS WL BE LIGHT AND S-SW WITH AN ERLY LAKE BREEZE WIND DEVELOPING AT KCMX IN THE AFTERNOON. THE ARRIVAL OF A SHARPER PRES GRADIENT OVER WRN UPR MI LATE TNGT WL RESULT IN SOME MARGINAL LLWS AT IWD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 354 AM EDT TUE JUN 26 2012 WITH RELATIVELY WEAK PRES GRADIENT AND HI STABILITY OVER THE COOL LAKE WATERS...EXPECT WINDS UNDER 20 KTS THROUGH THE FORECAST PERIOD. THE ONLY EXCEPTION WL BE ON THU INTO EARLY FRI...WHEN STRONGER WINDS UP TO 25 KTS ASSOCIATED WITH THE PASSAGE OF A LOW PRESSURE TROUGH MIGHT IMPACT MAINLY THE NCENTRAL LAKE. A MOISTER AIRMASS THAT ARRIVES AHEAD OF THIS TROF MAY ALSO CAUSE SOME PATCHY FOG ON WED NIGHT INTO THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
651 AM EDT TUE JUN 26 2012 .AVIATION... //DISCUSSION... HIGH PRESSURE WILL MAINTAIN QUIET CONDITIONS ACROSS SOUTHEAST MICHIGAN INTO WEDNESDAY. NORTHWEST WINDS WILL INCREASE SLIGHTLY TODAY AS DEEPER MIXING ENSUES DURING THE AFTERNOON - THE GUST POTENTIAL SHOULD REMAIN BELOW 20 KNOTS. CLOUDS WILL BE VERY LIMITED - POSSIBLY A SCATTERED DECK AROUND 6KFT AT THE NORTHERN TERMINALS. //DTW THRESHOLD THREATS... * NONE && .PREV DISCUSSION...ISSUED 342 AM EDT TUE JUN 26 2012 SHORT TERM... TODAY AND TONIGHT SPRAWLING HIGH PRESSURE WILL GOVERN THE STATE OF THE ATMOSPHERE ACROSS THE SOUTHERN LAKES REGION THROUGH TONIGHT. SOUTHEAST MICHIGAN REMAINS WITHIN THE NORTHWESTERLY GRADIENT FLOW ALONG THE ADVANCING FLANK OF THE SURFACE HIGH. THEREFORE...EXPECT SURFACE WINDS WILL MAINTAIN SOME INTEGRITY ALONG WITH A GUST COMPONENT SUPPORTED BY A WELL MIXED DIURNAL CONVECTIVE BOUNDARY LAYER. MOISTURE INFILTRATION FROM THE NORTH IS EVIDENT ON THE GOES-E 11-3.9U IMAGERY. THE 26.06 RAP AND TO A LESSER EXTENT 26.00 NAM HAVE A SIGNATURE OF THE MOISTURE FIELD IN THEIR THETA-E DEPICTION. THE MODEST AMBIENT THETA-E INCREASE AROUND 800MB SHOULD BE ENOUGH TO BE ACTED UPON BY YET ANOTHER MATURE DIURNAL BOUNDARY LAYER. AGAIN... ONLY EXPECTING A MODEST RESPONSE IN THE PRODUCTION OF DIURNAL CUMULUS - FEW TO SCATTERED COVERAGE. OTHERWISE...THE SKY WILL SLOWLY FILL WITH CIRRUS TONIGHT AS HIGH LEVEL MOISTURE SPILLS OVER THE LARGE UPPER RIDGE OVER THE PLAINS. THE ELDERLY POLAR AIRMASS CONTINUES TO UNDERGO MODIFICATION AS IT EXITS EAST OF THE REGION. TEMPERATURES THROUGH THE MIXED LAYER ARE EXPECTED TO BE ROUGHLY 4C WARMER TODAY - THIS TRANSLATES TO A 6-8F INCREASE OVER YESTERDAY/S MAXES. CONTINUED WARM ADVECTION THROUGH THE LOWER TROPOSPHERE TONIGHT...IN CONJUNCTION WITH HIGHER MOISTURE CONTENT IN THE MIDDLE AND UPPER PORTIONS OF THE TROPOSPHERE...WILL SUPPORT A WARMER NIGHT TONIGHT - MORE NEAR LATE JUNE AVERAGES. LONG TERM...WEDNESDAY THROUGH MONDAY THE MIDLEVEL GYRE AND DEEP CYCLONIC FLOW WILL PUSH ENOUGH EASTWARD ON WEDNESDAY TO ALLOW FOR THE ADVENT OF WARM AIR ADVECTION ACROSS THE CENTRAL GREAT LAKES. THE MIDLEVEL RIDGE AXIS IMMEDIATELY UPSTREAM WILL LEAN INTO PORTIONS OF WISCONSIN AND LAKE MICHIGAN BY LATE IN THE AFTERNOON. THIS FEATURE COINCIDES NICELY WITH THE EDGE OF THE MIDLEVEL THETA E RIDGE/ELEVATED MIXED LAYER. THE ELEVATED PORTION OF THE WARM FRONT IS PROGGED TO PRECEDE THIS RIDGE AXIS A FAIR AMOUNT...MAKING INROADS TO THE LAKE HURON VICINITY DURING THE AFTERNOON HOURS. COINCIDENTALLY...A SOUTHWARD DIVING JET MAXIMUM IS EXPECTED TO SLIDE DOWN THE FACE OF THE RIDGE INTO LAKE HURON DURING THE AFTERNOON. RIGHT ENTRANCE REGION DYNAMICS WILL COME INTO PLAY AS WELL AS INCREASED 700-500MB DEFORMATION AND A NOSE OF INCREASED 320K SYSTEM RELATIVE ISENTROPIC ASCENT. THE MIX OF DYNAMICS NECESSITATES A LOW CHANCE POP FOR AREAS IMMEDIATELY EAST OF THE THUMB OUT ON LAKE HURON...ALTHOUGH DRY AIR IN THE LOWEST 9KFT WILL SEVERELY LIMIT MEASURING POTENTIAL. WITH STEEP LAPSE RATES REMAINING UPSTREAM WILL NOT INCLUDE THE MENTION OF THUNDER. SURFACE HIGH PRESSURE OVER THE CWA...WAA AND ALOT OF INSOLATION FITS THE RECENT PROFILE FOR OVERACHIEVING TEMPERATURES. HAVE NO QUALMS WITH TEMPERATURES MAKING IT INTO THE MIDDLE TO UPPER 80S ON WEDNESDAY. REGARDING THE MUCH DRONED ABOUT THURSDAY PERIOD...THE MIDLEVEL RIDGE IS EXPECTED TO FALL ACROSS SOUTHEASTERN MICHIGAN. THIS WILL ALLOW THE MIDLEVEL RIDGE AXIS TO PASS OVERHEAD...HERALDING THE ARRIVAL OF AN ULTRA IMPRESSIVE MIXED LAYER/AND WARM TEMPERATURES ALOFT. IT IS THIS WARM AIR ALOFT THAT LEADS TO THE QUESTION MARKS CONCERNING THURSDAY HIGHS. THE NEW TWIST OFFERED BY THIS FORECAST ISSUANCE IS THE EXPECTATION THAT A COVERAGE OF CLOUDS (SEE ECMWF 500MB RH) WILL SWEEP ACROSS ALL OF THE AREA DURING THE DAY ON THURSDAY. NOW HOW OPAQUE THESE CLOUDS WILL BE IS ANYONES GUESS. HOWEVER...TYPICALLY WITNESS SHORTWAVE MATERIAL AND MID TO HIGH CLOUD DEBRIS PILE UP ON THE BACKSIDE OF THESE RIDGES. SO...PATTERN RECOGNITION SUGGESTS A FAIR AMOUNT. STILL DON/T THINK IT WILL IMPACT TEMPERATURES MUCH GIVEN A WELL MIXED PROFILE...BUT IT SHOULD LIMIT THE RUNAWAY BEHAVIOR OF DAYTIME TEMPERATURES. SO THE APPROACH THIS ISSUANCE WAS TO MASSAGE HIGH TEMPERATURES DOWNWARD A FEW DEGREES WITH A SOLID LOWER TO MIDDLE 90S. WITH THE TANGIBLE INCREASE OF CYCLONIC VORTICITY ALOFT AND INSTABILITY BUILDING IN THE MIDLEVELS DID ADD A SLIGHT CHANCE POP DURING THE AFTERNOON FOR MUCH OF THE AREA. STILL EXPECTING THE ATMOSPHERE TO BE WELL CAPPED...BUT THERE IS A CHANCE NONETHELESS. DEGREE OF INSTABILITY...SBCAPES IN EXCESS OF 3000-3500 J/KG SIGNIFIES THIS THREAT NEEDS TO BE WATCHED CAREFULLY...AS ANY CONVECTION THAT WILL FIRE WILL CARRY AN IMMEDIATE SEVERE RISK. A TRAILING JET MAXIMUM SETTLING SOUTHWARD INTO NORTHERN WISCONSIN AND THE EDGE OF THE THETA E RIDGE (THINK FRONTAL ZONE) REQUIRES A CONTINUED RAIN/THUNDERSTORM CHANCE THURSDAY NIGHT AND FRIDAY. ALOT OF QUESTIONS REGARDING OVERALL POTENTIAL BUT VARIOUS MODEL SOLUTIONS ARE SHOWING SOME CONVECTIVE VORTS/HOTSPOTS FIRING ALONG THE THETA E GRADIENT. HIGHS ON FRIDAY ARE EXPECTED TO REACH/EXCEED 90 DEGREES. A ZONAL JET PATTERN AND A DECAYING SHORTWAVE RIDGE WORKING THROUGH THE GREAT LAKES...KEEPS A FAIRLY STAGNANT PATTERN IN PLACE FOR SATURDAY AND GOOD PART OF SUNDAY. RAIN CHANCES THIS WEEKEND APPEAR TOTALLY DEPENDENT UPON ANY MCS TYPE ACTIVITY DIRECTLY HITTING THE AREA. CONFIDENCE REMAINS TOO LOW TO GIVE MUCH DISCUSSION ON SPECIFICS. HOWEVER...THE SLOW EVOLVING PATTERN GIVES REASON FOR HIGHS BOTH SATURDAY AND SUNDAY TOPPING OUT IN THE UPPER 80S TO NEAR 90 DEGREES. MARINE... MODEST NORTHWESTERLY FLOW WILL MAINTAIN TODAY. THE OFFSHORE NATURE OF THE FLOW WILL USHER THE HIGHEST WAVES TO THE CANADIAN SHORE OF LAKE HURON. FURTHERMORE...OBSERVED WAVE HEIGHTS HAVE BEHAVED WELL ENOUGH TO LOWER EXPECTATIONS FOR THE SMALL CRAFT WAVE CONDITIONS ALONG THE THUMB SHORELINE. THE FLOW WILL SUBSIDE TONIGHT AS SURFACE HIGH PRESSURE DRIFTS OVERHEAD...ONLY TO SUCCUMB TO A BRIEF EPISODE OF MODERATE SOUTHWESTERLY FLOW ON WEDNESDAY AS A WARMER AIRMASS ENCROACHES. GENERALLY SPEAKING...THE WARM FLOW WILL HAVE DIFFICULTY MIXING TO THE SURFACE - SAVE LOCATIONS OVER INNER SAGINAW BAY AND WESTERN LAKE ERIE...WHERE THE WATER SURFACE IS WARMER TO OFFSET THE NEGATIVE STABILITY INFLUENCES. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....MANN SHORT TERM...MANN LONG TERM....CB MARINE.......MANN YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 AM EDT TUE JUN 26 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 354 AM EDT TUE JUN 26 2012 00Z RAOBS/LATEST RUC ANALYSIS AND WV IMAGERY SHOWS NW FLOW ALF OVER THE UPR LKS BTWN HI AMPLITUDE RDG IN THE PLAINS AND DEEP TROF OVER QUEBEC/NE CONUS. A SHRTWV IS DROPPING SEWD THRU ONTARIO IN THIS NW FLOW ALF. ALTHOUGH THERE IS QUITE A BIT OF ASSOCIATED CLD COVER OVER ONTARIO INTO ERN LK SUP WHICH IS ON TRACK TO IMPACT THE ERN CWA... MOST OF THIS CLD IS OF THE MID/HI VARIETY PER DRYNESS OF THE LLVLS SHOWN ON THE 00Z YPL RAOB. OTRW...WITH SFC HI PRES SITUATED OVER NE WI...SKIES ARE MOCLR OVER THE W HALF. MORE CLD/SOME SHRA/TS ARE IMPACTING THE NRN PLAINS IN ADVANCE OF H85 WARM FNT DESPITE PRESENCE OF IMPRESSIVE CAP SHOWN ON THE 00Z BISMARCK/ABERDEEN RAOBS THAT IS ON THE NRN EDGE OF VERY WARM AIRMASS IN THE CENTRAL PLAINS. TODAY...UPR RDG TO THE W WL MOVE SLOWLY TO THE E...WITH SFC HI PRES SINKING SLOWLY S INTO THE LWR LKS/OH RIVER VALLEY BY 00Z WED. EXPECT AREA OF MID/HI CLD ASSOCIATED WITH SHRTWV IN ONTARIO TO IMPACT MAINLY THE ERN CWA THIS MRNG. MORE HI CLD RELATED TO ISENTROPIC LIFT IN ADVANCE OF H85 WARM FNT IN THE PLAINS WL ALSO STREAM OVER THE RDG INTO THE CWA THIS AFTN...BUT OVERALL THE DAY WL TURN OUT MOSUNNY WITH LARGER SCALE SUBSIDENCE MAINTAINING DRY AIRMASS. FCST H85 TEMPS CLIMBING TO 14-15C AND MIXING TO H825 ON GFS/NAM FCST SDNGS YIELDS HI TEMPS REACHING 80-85 AWAY FM LK MODERATION...WHICH WL BE MAXIMIZED NEAR LK MI IN THE H925 SW FLOW. BUT MAJORITY OF MODELS INDICATE A WEAKER LK BREEZE WL FORM OFF LK SUP AS WELL AND BRING SOME LOCAL COOLING TO SHORE COMMUNITIES. TNGT...WITH STRENGTHENING SW H925 FLOW LIFTING H85 TEMPS TOWARD 20C BY 12Z WED NEAR THE WI BORDER AS WELL AS INCRSG PWAT TOWARD 1 INCH OVER THE E TO 1.5 INCH OVER THE W...EXPECT A MUCH WARMER NGT. TEMPS WL BE HIEST OVER THE W HALF IN THE DOWNSLOPE AREAS NEAR LK SUP. THE COOLEST TEMPS WL BE OVER THE INTERIOR E CLOSER TO SOMEWHAT WEAKER PRES GRADIENT. DESPITE THE INCRSG ABSOLUTE MSTR...THE AIRMASS WL SO WARM THE RH WL BE TOO LO FOR ANY PCPN. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 354 AM EDT TUE JUN 26 2012 MODELS REMAIN IN GOOD AGREEMENT IN IN OVERALL LARGE SCALE PATTERN THROUGH NEXT WEEKEND. BROAD 595 H5 RIDGE THAT PRODUCED ANOTHER DAY OF RECORD TRIPLE-DIGIT HEAT OVER PORTIONS OF THE SOUTHERN PLAINS ON MONDAY IS FCST TO EXPAND INTO THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES BY WEDNESDAY. CORE OF WARMEST AIR /H85 TEMPS AOA +24C/ REMAINS SOUTH OF UPR LAKES...BUT WILL STILL HAVE WELL ABOVE NORMAL TEMPS OVR UPR MICHIGAN WEDNESDAY/THURSDAY AND PROBABLY FRIDAY AS WELL. SLIGHT COOLING IS FCST FOR THE WEEKEND AS LARGER SCALE HEIGHT FALLS DEVELOP IN RESPONSE TO UPPER LOW SLIDING ACROSS ONTARIO AND QUEBEC AND INTO AT LEAST NORTHERN PORTION OF GREAT LAKES. ON WEDNESDAY...SEEMS THERE IS STILL A SMALL RISK OF INCREASED MID CLOUDS AND PERHAPS A SHRA/TSRA WORKING ACROSS CWA ON NOSE OF H85 MOISTURE TRANSPORT. GFS LOOKS LIKE ECMWF DID A FEW NIGHTS AGO SHOWING GOOD SIGNAL WITH THE MOISTURE TRANSPORT FOR PRECIP. MORE RECENT RUNS OF ECMWF ALONG WITH CANADIAN KEEP IT DRY. GIVEN UNCERTAINTY OPTED TO JUST BUMP SKY UP FOR NOW AND KEEP FCST DRY. MINIMAL DEEPER MOISTURE PER FCST SOUNDINGS FM GFS WOULD LEAD TO SPRINKLES IF SOMETHING DID WORK ACROSS UPR MICHIGAN. IF MID CLOUDS ARE AROUND...H85-H7 MOISTURE TRANSPORT FCST WOULD POINT TO THEM EVADING BY EARLY AFTN. H85 TEMPS HAVE STEADILY TRENDED WARMER THE LAST FEW DAYS FOR WEDNESDAY. NOW APPEARS THAT SOLID +20C H85 TEMPS ARE AROUND IN THE AFTN. CONTINUED TREND OF INCREASING HIGHS WITH MANY AREAS TOPPING OUT IN THE MID-UPR 80S. GIVEN TRENDS WOULD NOT BE SHOCKED TO SEE LOWER 90S IN DOWNSLOPE AREAS OF SCNTRL CWA WITH WSW BLYR FLOW FCST. HUMIDITY WILL BE ON THE RISE AS SWATH OF H85 DWPNTS WELL ABOVE +10C PLOWS ACROSS RESULTING IN SFC DWPNTS SURGING INTO THE LOWER 60S FOR MAJORITY OF CWA IN THE AFTN. WEDNESDAY SHAPING UP TO BE THE MOST UNCOMFORTABLE DAY OF THE WEEK. ATTN ON WEDNESDAY AFTN WILL BE OVER NORTHERN PLAINS INTO MINNESOTA TO SEE WHAT IF ANY CONVECTION DEVELOPS WITH AMPLE INSTABILITY BUT VERY STOUT MID-LEVEL CAPPING AS H7 TEMPS ARE FCST WELL INTO THE TEENS. EDGE OF MUCAPE GRADIENT SUGGESTS MOST CONVECTION WILL STAY MAINLY IN THE NORTHERN PLAINS AND THEN DEFLECT INTO CANADA ON EDGE OF MID-LEVEL RIDGE. AFTER THAT IT IS UNCERTAIN HOW MUCH IF ANY CONVECTION WILL WORK BACK INTO UPR LAKES LATER WEDNESDAY NIGHT INTO THURSDAY MORNING. CAPPING OVR THE PLAINS WILL BE FIRMLY OVERHEAD AT THAT TIME WITH H7 TEMPS OVR UPR MICHIGAN 12Z THURSDAY OF +14C TO +16C. SOME HINTS AT MID-LEVEL MOISTURE TRANSPORT THAT MAY TRY TO TAKE ADVANTAGE OF ELEVATED INSTABILITY...BUT GIVEN THE CAPPING MAY BE HARD PRESSED TO SEE ANY CONVECTION. MODELS HAVE BEEN DIFFERING ON HOW QUICK TO BRING SFC FRONT THROUGH AREA ON THURSDAY BUT NOW SEEM TO BE IN FAVOR OF IDEA THAT BRINGS FRONT INTO WESTERN UPR MICHIGAN AROUND DAYBREAK ON THURSDAY AND INTO SCNTRL AND EAST CWA THURSDAY AFTN. CONVERGENCE ALONG FRONT IS WEAK AND THERE IS REALLY NOT MUCH CHANGE IN CAPPING. ALSO...H85-H7 MOISTURE TRANSPORT IS QUICKLY SHUNTED MORE SOUTH AND EAST OF UPR MICHIGAN AS H85 WINDS VEER MORE NORTHWEST IN THE MORNING. IF CONVECTION COULD DEVELOP /THINK THIS IS A PRETTY BIG QUESTION GIVEN STRENGTH OF CAPPING/ THEN SEVERE STORMS WOULD CERTAINLY BE POSSIBLE OVR SOUTH WITH 0-6KM SHEAR OVR 40 KTS AND MUCAPE OVR 2000-3000 J/KG. HAVE KEPT SLIGHT CHANCES IN FCST...BUT NO MORE AT THIS POINT WITH EXPECTED CAPPING. DEEP MIXING MAY LOWER DWPNTS/HUMIDITY VALUES SIGNIFICANTLY LATE IN THE DAY ON THURSDAY OVR WESTERN INTERIOR. KNOCKED DWPTS DOWN FURTHER /LOWER 50S/ BUT DID NOT GO NEAR AS LOW AS MIXED DWPNT TOOL GAVE. LATER SHIFTS WILL HAVE TO MONITOR TRENDS FOR DWPNTS/RH VALUES LATE THURSDAY. LOOKS QUIET IN THE WAKE OF THE FRONT ON FRIDAY. WEST WINDS ON KEWEENAW MAY GUST OVR 30 MPH...AND THIS IS WHERE THE MOST COOLING WILL BE REALIZED BEHIND THE FRONT. OTHERWISE...INCREASED TEMPS ON FRIDAY AS UPPER TROUGH REALLY HAS NOT FULLY ARRIVED BY THAT TIME AND H85 TEMPS ARE STILL WARM IN THE MIDDLE TEENS. SEE NO REASON WHY MANY LOCATIONS WILL NOT CRACK 80 DEGREES YET AGAIN...WITH MID-UPR 80S POSSIBLE SOUTH CNTRL. LATEST ECMWF CONTINUES TO SHOW +21C H85 TEMPS SUPPORTING MAXES AROUND 90 DEGREES OVR MUCH OF CNTRL. DEFINITELY SEEMS LIKE MODELS ARE BACKING AWAY FM THE COOLING THEY WERE SHOWING EARLIER FOR FRIDAY. DOES LOOK A BIT COOLER FOR THE WEEKEND AS LARGER SCALE HEIGHTS FALL SOME WITH UPR LOW SETTLING ACROSS ONTARIO/QUEBEC. EVEN SO...MAX TEMPS BOTH SATURDAY AND MAYBE SUNDAY STILL PUSH PAST 80 DEGREES OVR CWA AWAY FM FLOW OFF LK SUPERIOR. GFS CONTINUES TO SHOW STRONGER SHORTWAVE/ELEVATED MID-LEVEL LAPSE RATES SLIDING THROUGH SATURDAY NIGHT INTO SUNDAY MORNING IN THE BROAD NW FLOW PATTERN ALOFT. CONSENSUS GAVE LOWER CHANCE POPS MAINLY ON SATURDAY NIGHT AND GENERALLY RAN WITH THAT IDEA AS DIFFERENT RUNS OF DIFFERENT MODELS HAVE BEEN HINTING AT THIS FOR A FEW DAYS NOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 130 AM EDT TUE JUN 26 2012 PLAN ON VFR CONDITIONS TO CONTINUE THIS FCST PERIOD WITH DRY HI PRES DOMINATING. WINDS WL BE LIGHT AND S-SW ON TUESDAY WITH AN ERLY LAKE BREEZE WIND DEVELOPING AT KCMX IN THE AFTERNOON. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 354 AM EDT TUE JUN 26 2012 WITH RELATIVELY WEAK PRES GRADIENT AND HI STABILITY OVER THE COOL LAKE WATERS...EXPECT WINDS UNDER 20 KTS THROUGH THE FORECAST PERIOD. THE ONLY EXCEPTION WL BE ON THU INTO EARLY FRI...WHEN STRONGER WINDS UP TO 25 KTS ASSOCIATED WITH THE PASSAGE OF A LOW PRESSURE TROUGH MIGHT IMPACT MAINLY THE NCENTRAL LAKE. A MOISTER AIRMASS THAT ARRIVES AHEAD OF THIS TROF MAY ALSO CAUSE SOME PATCHY FOG ON WED NIGHT INTO THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
342 AM EDT TUE JUN 26 2012 .SHORT TERM... TODAY AND TONIGHT SPRAWLING HIGH PRESSURE WILL GOVERN THE STATE OF THE ATMOSPHERE ACROSS THE SOUTHERN LAKES REGION THROUGH TONIGHT. SOUTHEAST MICHIGAN REMAINS WITHIN THE NORTHWESTERLY GRADIENT FLOW ALONG THE ADVANCING FLANK OF THE SURFACE HIGH. THEREFORE...EXPECT SURFACE WINDS WILL MAINTAIN SOME INTEGRITY ALONG WITH A GUST COMPONENT SUPPORTED BY A WELL MIXED DIURNAL CONVECTIVE BOUNDARY LAYER. MOISTURE INFILTRATION FROM THE NORTH IS EVIDENT ON THE GOES-E 11-3.9U IMAGERY. THE 26.06 RAP AND TO A LESSER EXTENT 26.00 NAM HAVE A SIGNATURE OF THE MOISTURE FIELD IN THEIR THETA-E DEPICTION. THE MODEST AMBIENT THETA-E INCREASE AROUND 800MB SHOULD BE ENOUGH TO BE ACTED UPON BY YET ANOTHER MATURE DIURNAL BOUNDARY LAYER. AGAIN... ONLY EXPECTING A MODEST RESPONSE IN THE PRODUCTION OF DIURNAL CUMULUS - FEW TO SCATTERED COVERAGE. OTHERWISE...THE SKY WILL SLOWLY FILL WITH CIRRUS TONIGHT AS HIGH LEVEL MOISTURE SPILLS OVER THE LARGE UPPER RIDGE OVER THE PLAINS. THE ELDERLY POLAR AIRMASS CONTINUES TO UNDERGO MODIFICATION AS IT EXITS EAST OF THE REGION. TEMPERATURES THROUGH THE MIXED LAYER ARE EXPECTED TO BE ROUGHLY 4C WARMER TODAY - THIS TRANSLATES TO A 6-8F INCREASE OVER YESTERDAY/S MAXES. CONTINUED WARM ADVECTION THROUGH THE LOWER TROPOSPHERE TONIGHT...IN CONJUNCTION WITH HIGHER MOISTURE CONTENT IN THE MIDDLE AND UPPER PORTIONS OF THE TROPOSPHERE...WILL SUPPORT A WARMER NIGHT TONIGHT - MORE NEAR LATE JUNE AVERAGES. && .LONG TERM...WEDNESDAY THROUGH MONDAY THE MIDLEVEL GYRE AND DEEP CYCLONIC FLOW WILL PUSH ENOUGH EASTWARD ON WEDNESDAY TO ALLOW FOR THE ADVENT OF WARM AIR ADVECTION ACROSS THE CENTRAL GREAT LAKES. THE MIDLEVEL RIDGE AXIS IMMEDIATELY UPSTREAM WILL LEAN INTO PORTIONS OF WISCONSIN AND LAKE MICHIGAN BY LATE IN THE AFTERNOON. THIS FEATURE COINCIDES NICELY WITH THE EDGE OF THE MIDLEVEL THETA E RIDGE/ELEVATED MIXED LAYER. THE ELEVATED PORTION OF THE WARM FRONT IS PROGGED TO PRECEDE THIS RIDGE AXIS A FAIR AMOUNT...MAKING INROADS TO THE LAKE HURON VICINITY DURING THE AFTERNOON HOURS. COINCIDENTALLY...A SOUTHWARD DIVING JET MAXIMUM IS EXPECTED TO SLIDE DOWN THE FACE OF THE RIDGE INTO LAKE HURON DURING THE AFTERNOON. RIGHT ENTRANCE REGION DYNAMICS WILL COME INTO PLAY AS WELL AS INCREASED 700-500MB DEFORMATION AND A NOSE OF INCREASED 320K SYSTEM RELATIVE ISENTROPIC ASCENT. THE MIX OF DYNAMICS NECESSITATES A LOW CHANCE POP FOR AREAS IMMEDIATELY EAST OF THE THUMB OUT ON LAKE HURON...ALTHOUGH DRY AIR IN THE LOWEST 9KFT WILL SEVERELY LIMIT MEASURING POTENTIAL. WITH STEEP LAPSE RATES REMAINING UPSTREAM WILL NOT INCLUDE THE MENTION OF THUNDER. SURFACE HIGH PRESSURE OVER THE CWA...WAA AND ALOT OF INSOLATION FITS THE RECENT PROFILE FOR OVERACHIEVING TEMPERATURES. HAVE NO QUALMS WITH TEMPERATURES MAKING IT INTO THE MIDDLE TO UPPER 80S ON WEDNESDAY. REGARDING THE MUCH DRONED ABOUT THURSDAY PERIOD...THE MIDLEVEL RIDGE IS EXPECTED TO FALL ACROSS SOUTHEASTERN MICHIGAN. THIS WILL ALLOW THE MIDLEVEL RIDGE AXIS TO PASS OVERHEAD...HERALDING THE ARRIVAL OF AN ULTRA IMPRESSIVE MIXED LAYER/AND WARM TEMPERATURES ALOFT. IT IS THIS WARM AIR ALOFT THAT LEADS TO THE QUESTION MARKS CONCERNING THURSDAY HIGHS. THE NEW TWIST OFFERED BY THIS FORECAST ISSUANCE IS THE EXPECTATION THAT A COVERAGE OF CLOUDS (SEE ECMWF 500MB RH) WILL SWEEP ACROSS ALL OF THE AREA DURING THE DAY ON THURSDAY. NOW HOW OPAQUE THESE CLOUDS WILL BE IS ANYONES GUESS. HOWEVER...TYPICALLY WITNESS SHORTWAVE MATERIAL AND MID TO HIGH CLOUD DEBRIS PILE UP ON THE BACKSIDE OF THESE RIDGES. SO...PATTERN RECOGNITION SUGGESTS A FAIR AMOUNT. STILL DON/T THINK IT WILL IMPACT TEMPERATURES MUCH GIVEN A WELL MIXED PROFILE...BUT IT SHOULD LIMIT THE RUNAWAY BEHAVIOR OF DAYTIME TEMPERATURES. SO THE APPROACH THIS ISSUANCE WAS TO MASSAGE HIGH TEMPERATURES DOWNWARD A FEW DEGREES WITH A SOLID LOWER TO MIDDLE 90S. WITH THE TANGIBLE INCREASE OF CYCLONIC VORTICITY ALOFT AND INSTABILITY BUILDING IN THE MIDLEVELS DID ADD A SLIGHT CHANCE POP DURING THE AFTERNOON FOR MUCH OF THE AREA. STILL EXPECTING THE ATMOSPHERE TO BE WELL CAPPED...BUT THERE IS A CHANCE NONETHELESS. DEGREE OF INSTABILITY...SBCAPES IN EXCESS OF 3000-3500 J/KG SIGNIFIES THIS THREAT NEEDS TO BE WATCHED CAREFULLY...AS ANY CONVECTION THAT WILL FIRE WILL CARRY AN IMMEDIATE SEVERE RISK. A TRAILING JET MAXIMUM SETTLING SOUTHWARD INTO NORTHERN WISCONSIN AND THE EDGE OF THE THETA E RIDGE (THINK FRONTAL ZONE) REQUIRES A CONTINUED RAIN/THUNDERSTORM CHANCE THURSDAY NIGHT AND FRIDAY. ALOT OF QUESTIONS REGARDING OVERALL POTENTIAL BUT VARIOUS MODEL SOLUTIONS ARE SHOWING SOME CONVECTIVE VORTS/HOTSPOTS FIRING ALONG THE THETA E GRADIENT. HIGHS ON FRIDAY ARE EXPECTED TO REACH/EXCEED 90 DEGREES. A ZONAL JET PATTERN AND A DECAYING SHORTWAVE RIDGE WORKING THROUGH THE GREAT LAKES...KEEPS A FAIRLY STAGNANT PATTERN IN PLACE FOR SATURDAY AND GOOD PART OF SUNDAY. RAIN CHANCES THIS WEEKEND APPEAR TOTALLY DEPENDENT UPON ANY MCS TYPE ACTIVITY DIRECTLY HITTING THE AREA. CONFIDENCE REMAINS TOO LOW TO GIVE MUCH DISCUSSION ON SPECIFICS. HOWEVER...THE SLOW EVOLVING PATTERN GIVES REASON FOR HIGHS BOTH SATURDAY AND SUNDAY TOPPING OUT IN THE UPPER 80S TO NEAR 90 DEGREES. && .MARINE... MODEST NORTHWESTERLY FLOW WILL MAINTAIN TODAY. THE OFFSHORE NATURE OF THE FLOW WILL USHER THE HIGHEST WAVES TO THE CANADIAN SHORE OF LAKE HURON. FURTHERMORE...OBSERVED WAVE HEIGHTS HAVE BEHAVED WELL ENOUGH TO LOWER EXPECTATIONS FOR THE SMALL CRAFT WAVE CONDITIONS ALONG THE THUMB SHORELINE. THE FLOW WILL SUBSIDE TONIGHT AS SURFACE HIGH PRESSURE DRIFTS OVERHEAD...ONLY TO SUCCUMB TO A BRIEF EPISODE OF MODERATE SOUTHWESTERLY FLOW ON WEDNESDAY AS A WARMER AIRMASS ENCROACHES. GENERALLY SPEAKING...THE WARM FLOW WILL HAVE DIFFICULTY MIXING TO THE SURFACE - SAVE LOCATIONS OVER INNER SAGINAW BAY AND WESTERN LAKE ERIE...WHERE THE WATER SURFACE IS WARMER TO OFFSET THE NEGATIVE STABILITY INFLUENCES. && .AVIATION...ISSUED 100 AM EDT TUE JUN 26 2012 //DISCUSSION... DRY NORTHWEST FLOW WITH HIGH PRESSURE BUILDING INTO THE GREAT LAKES WILL BRING CLEAR SKIES THROUGH TUESDAY. NORTHWEST WINDS WILL PICK UP SLIGHTLY AS DEEPER MIXING ENSUES DURING THE AFTERNOON...BUT WITH THE GUST POTENTIAL REMAINING BELOW 20 KNOTS. //DTW THRESHOLD THREATS... * NONE && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...MANN LONG TERM....CB MARINE.......MANN AVIATION.....MANN YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 AM EDT TUE JUN 26 2012 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 409 PM EDT MON JUN 25 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM THE SRN PLAINS INTO CNTRL CANADA A TROUGH OVER ERN NOAM RESULTING IN NW FLOW THROUGH THE WRN GREAT LAKES. AT THE SFC...HIGH PRES WAS LOCATED OVER WRN LAKE SUPERIOR BRINGING NW WINDS INTO THE ERN CWA. UNDER CLEAR SKIES...AFTERNOON HEATING/MIXING HAS DROPPED INLAND DEWPOINTS INTO THE UPPER 30S AND LOWER 40S. TONIGHT...THE SFC HIGH WILL DRIFT SLOWLY TO THE S KEEPING SKIES MOSTLY CLEAR. WITH WEAK RETURN FLOW DEVELOPING AND SLIGHTLY HIGHER PWAT VALUES INTO THE 0.60 INCH TO 0.75 INCH RANGE...TEMPS ARE NOT EXPECTED TO DROP AS MUCH AS SUN NIGHT. HOWEVER...GOOD RADIATIONAL COOLING SHOULD STILL ALLOW INLAND MIN READINGS TO FALL INTO THE LOWER 40S WHICH IS CLOSER TO THE LOWER END OF GUIDANCE. TUESDAY...SFC AND MID LEVEL RIDGING WILL STILL DOMINATE THE AREA WITH DRY WEATHER AND MOSTLY CLEAR SKIES. WITH 850 MB TEMPS CLIMBING BACK INTO THE 12C-14C RANGE...GUIDANCE MAX INLAND MAX TEMPS IN THE UPPER 70S TO AROUND 80 LOOKED REASONABLE. MIXING SHOULD PUSH DEWPOINTS INTO THE MID 40S RESULTING IN MIN RH VALUES FROM 30 TO 35 PERCENT. HOWEVER...LIGHT WINDS SHOULD MINIMIZE FIRE WX CONCERNS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 409 PM EDT MON JUN 25 2012 OVERALL PATTERN IN THE LONG TERM WILL BE DOMINATED BY A MID-LEVEL RIDGE THROUGH MID-WEEK...WITH MINIMAL PRECIP CHANCES INTO THE WEEKEND. MAIN QUESTIONS REVOLVE AROUND HOW THE RIDGE WILL BREAK DOWN WEDNESDAY INTO THURSDAY AND THE ASSOCIATED COLD FRONT PASSAGE DURING THAT TIME. TUESDAY NIGHT THROUGH WEDNESDAY... AT 00Z WEDNESDAY...THE MID-LEVEL RIDGE AXIS WILL BE LOCATED ALONG THE MISSOURI RIVER VALLEY WHILE THE SURFACE RIDGE WILL BE EXTENDING FROM SOUTHERN LAKE MICHIGAN THROUGH EASTERN UPPER MI. THE GFS AND LATEST ECMWF ARE HINTING AT A SMALL AMOUNT OF PRECIP ON A WEAK MID-LEVEL IMPULSE TRAVERSING OVER THE TOP OF THE RIDGE TUESDAY EVENING. THIS WOULD ONLY AFFECT THE FAR EASTERN CWA WHERE A POCKET OF H8 MOISTURE TRANSPORT WILL BE LOCATED. HOWEVER...LIMITED MOISTURE ELSEWHERE WITH THE SFC RIDGE AXIS AND BEST FORCING FROM THE RIGHT ENTRANCE OF THE UPPER JET REMAINING TO THE NORTH WOULD TEND TO A DRIER FORECAST. THEREFORE...WILL STICK WITH PREVIOUS FORECAST AND KEEP PRECIP OUT FOR THE TIME BEING. MAIN CORE OF WARM AIR WILL ARRIVE ON WEDNESDAY...ESPECIALLY ACROSS THE WEST. H8 TEMPS WILL BE AOA 20C FOR THE WEST AND 17C FOR THE EAST BY MIDDAY WEDNESDAY. SHOULD MIX TO ABOUT H8 DURING THE DAY...SO TEMPS THERE ARE A GOOD INDICATION OF SFC TEMP POTENTIAL. HAVE BUMPED UP TEMPS TO THE UPPER 80S OUT WEST ACCORDINGLY. WEDNESDAY NIGHT THROUGH THURSDAY... A SHORTWAVE TROUGH CURRENTLY MOVING INTO THE NW STATES WILL TRY TO ERODE THE RIDGE ACROSS THE CENTRAL STATES TUESDAY INTO THURSDAY. MODEL VARIABILITY IS STILL A LITTLE HIGH ON THE TIMING OF RIDGE DEAMPLIFICATION. THE ECMWF MAINTAINS LOW-LEVEL WAA INTO THE GREAT LAKES REGION THROUGH WEDNESDAY...THEREBY KEEPING THE RIDGE A LITTLE SHARPER. THE GFS SEEMS TO HAVE PICKED UP ON THIS TREND OVER THE PAST FEW RUNS AS WELL. AS IS GENERALLY THE CASE IN THESE PATTERNS...THE RIDGE WILL LIKELY REMAIN IN CONTROL A LITTLE LONGER THAN CURRENT GUIDANCE PREDICTS. MID TO HIGH CLOUD COVER WILL MOVE IN BY WEDNESDAY EVENING ACROSS THE WEST HALF AND SHOULD KEEP TEMPS FROM FALLING BELOW 65 ACROSS THE WEST. FARTHER EAST...LOWER DEWPOINTS AND LESS CLOUD COVER SHOULD RESULT IN SLIGHTLY COOLER LOWS IN THE LOW 60S. A COLD FRONT ASSOCIATED WITH A SFC LOW FORMING AHEAD OF THE SHORTWAVE WILL ATTEMPT TO PASS THROUGH THE CWA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY AFTERNOON. THE ECMWF HAS BEEN A LITTLE SLOWER WITH THIS PASSAGE THAN THE GFS. COMBINED WITH THE SLOWER SHORTWAVE IDEA...WILL TREND TOWARD THE ECMWF APPROACH FOR FRONTAL PASSAGE. MOISTURE AVAILABILITY HAS BECOME A QUESTION WITH TROPICAL STORM DEBBIE SPINNING IN THE NE GULF OF MEXICO. DEBBIE WILL LIKELY REMAIN THERE INTO WEDNESDAY...WHICH WILL KEEP FLOW MOSTLY OFFSHORE ACROSS THE GULF AND PREVENT NORTHWARD RETURN OF MOISTURE NORTHWARD AHEAD OF THE COLD FRONT. AM NOT CONFIDENT THAT MUCH PRECIP WILL BE SEEN WITH THIS FRONT. STRONG CONVECTION COULD BE POSSIBLE SOUTH-CENTRAL DURING THE AFTERNOON...BUT CAP FROM THE SLOWLY DEPARTING RIDGE WILL LIKELY LIMIT ANY PRECIP TO A FEW SPOTTY SHOWERS. COOLER AIR LAGS THE FRONT SOMEWHAT...SO TEMPS HAVE BEEN BUMPED UP A DEGREE OR TWO OVER SEVERAL AREAS FOR THURSDAY. WILL LIKELY SEE TEMPS AROUND 90 ACROSS THE SOUTH CENTRAL CWA. COOLEST AREAS WILL REMAIN CONFINED TO THE LAKE MICHIGAN COASTLINE WITH ONSHORE WINDS. THOUGH WITH LAKE MICHIGAN WATER TEMPS NOW IN THE 60S...COOLING EFFECT IS DIMINISHING. RH VALUES WILL DROP BEHIND THE FRONT AS A PUNCH OF DRY AIR WORKS INTO THE UPPER MS VALLEY. HOWEVER...WINDS ARE EXPECTED TO STAY UNDER 15 MPH WITH THE EXCEPTION OF LOCATIONS WEST ALONG LAKE SUPERIOR. ELEVATED FIRE CONCERNS ARE NOT AN ISSUE ATTM. THURSDAY NIGHT THROUGH MONDAY... THE PATTERN BECOMES GENERALLY ZONAL AFTER THURSDAYS FRONTAL PASSAGE. A WNW MID-LEVEL FLOW WILL BE PREDOMINATE AND WILL BRING A COUPLE VERY WEAK WAVES OF ENERGY THROUGH THE UPPER GREAT LAKES AS THE WAVE RESPONSIBLE FOR THE FRONTAL PASSAGE REMAINS OVER FAR NORTHERN ONTARIO. OVERALL...CONFIDENCE IN ANY WIDESPREAD PRECIP EVENTS THROUGH THE WEEKEND IS LOW AS MOISTURE REMAINS SOUTH. ONE OF THE WEAK WAVES QUICKLY MOVES THROUGH SATURDAY NIGHT INTO SUNDAY...BUT TIMING IS UNCERTAIN RIGHT NOW. ONCE AGAIN...AMPLE MOISTURE WILL BE AN ISSUE WITH THIS SYSTEM AS THURSDAYS COLD FRONT STALLS FROM IA TO IN AND ROBS THE AREA OF ANY CHANCE OF DECENT MOISTURE RETURN. OVERALL TEMPERATURES SHOULD BE AROUND NORMAL WITH THE TRANQUIL PATTERN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 130 AM EDT TUE JUN 26 2012 PLAN ON VFR CONDITIONS TO CONTINUE THIS FCST PERIOD WITH DRY HI PRES DOMINATING. WINDS WL BE LIGHT AND S-SW ON TUESDAY WITH AN ERLY LAKE BREEZE WIND DEVELOPING AT KCMX IN THE AFTERNOON. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 PM EDT MON JUN 25 2012 WITH RELATIVELY WEAK PRES GRADIENT AND HI STABILITY OVER THE COOL LAKE WATERS...EXPECT WINDS UNDER 20 KTS THROUGH THE FORECAST PERIOD. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TK AVIATION...VOSS MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
119 AM EDT TUE JUN 26 2012 .SYNOPSIS.../ISSUED AT 346 PM/ HIGH PRESSURE WILL KEEP NORTHERN MICHIGAN MOSTLY CLEAR AND DRY OVER THE NEXT COUPLE DAYS. AS THE HIGH MOVES AWAY...A WARM AND MOIST AIRMASS WILL TAKE ITS PLACE...BRINGING TEMPERATURES WELL INTO THE 80S BY WEDNESDAY AND THURSDAY. PRECIPITATION IS NOT EXPECTED UNTIL AT LEAST THURSDAY NIGHT. FEF/SWR && .UPDATE... ISSUED AT 1258 AM EDT TUE JUN 26 2012 MAIN CONCERNS OVER THE NEXT FEW HOURS ARE THE RETURNS OFF THE 88D TO THE NORTH OF WHITEFISH BAY. CONSIDERING THAT THE MQT AND APX RADARS ARE PICKING THEM UP AT HIGHER THAN 10000 FT THINK THAT THEY ARE SPRINKLES AT MOST. HRRR SHOWS SOMETHING MOVING INTO THE AREA BY 10Z, AND THE CIGS DO FALL TO 2500 FT UPSTREAM. SO WILL KEEP IT AT SPRINKLES FOR NOW AND CONTINUE TO MONITOR THE RETURNS AS THEY MOVE OVER SOME OBSERVATIONAL PLATFORMS EARLY THIS MORNING. OTHERWISE, HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION. WINDS OVER LAND ARE LIGHT AND WILL CONTINUE THAT WAY INTO THE MORNING. UPDATE ISSUED AT 1011 PM EDT MON JUN 25 2012 ONLY A FEW MINOR MODIFICATIONS MADE TO FORECAST LATE THIS EVENING. GIVEN DECENT VERTICAL MIXING TODAY AND LOWER DEW POINT AIR MASS...HAVE CONTINUED TREND OF PREVIOUS FORECASTER AND COMPLETELY REMOVED PATCHY FOG FROM FORECAST. STILL EXPECT MAINLY CLEAR SKIES...BUT HAVE ADDED SOME PATCHY CLOUDS THROUGH THE NIGHT FOR ERN AND FAR NE LOWER...BASED ON SATELLITE TRENDS SHOWING SPOTTY MID CLOUDS DROPPING OUT OF ONTARIO. OVERNIGHT LOW TEMPS LOOK ON TARGET. UPDATE ISSUED AT 646 PM EDT MON JUN 25 2012 GOING FORECAST ON TARGET...AND TWEAKS TO FORECAST GRIDS HAVE BEEN MINIMAL THUS FAR. REMAINING DIURNAL CU (LOCATED EAST OF US-127 AND SOUTH OF M-32 CORRIDORS) CONTINUE TO STEADILY DIMINISH. OTHERWISE SKIES ARE CLEAR. && .SHORT TERM.../ISSUED AT 346 PM/...THIS EVENING AND TONIGHT ...MOSTLY CLEAR WITH DIMINISHING WINDS AND CHILLY TEMPS INLAND... PATTERN: ANOMALOUS -NAO CONTINUES FOR THIS TIME OF YEAR. THE STRONGEST SIGNAL USUALLY OCCURS IN THE COLD SEASON. THE GTLKS ARE JUST UPSTREAM OF AN OMEGA BLOCK CENTERED OVER THE DAVIS STRAIT/ GREENLAND. UPR FLOW IS HIGHLY AMPLIFIED OVER NOAM BEHIND DEVELOPING NEW ENGLAND CUT-OFF LOW. HOT SUBTROPICAL HIGH OVER THE HIGH PLAINS EXTENDS FAR N INTO CANADIAN PRAIRIES. ADVANCING TROF OVER THE PAC NW WILL NUDGE THIS HIGH EWD. THIS WILL MAINTAIN NNW FLOW INTO THE GTLKS THRU TUE BUT WITH 40M HGT RISES. AT THE SFC: HIGH PRES IS OVER WRN LAKE SUP AT 19Z WILL SLIDE TO MKE BY DAYBREAK TUE AND INTO SRN LAKE MI BY SUNSET. NOW: AS EXPECTED YESTERDAY...THE CLIMB TO HIT 70F HAS BEEN SLOW. MOST PLACES DIDN`T REACH IT UNTIL 3 PM! TODAY`S TEMPS ARE 5-8F BELOW NORMAL. STRATOCU HAVE FADED OVER THE ERN U.P. AND NW LOWER AND THE TREND IS SEWD. THESE CLOUDS WILL BE GONE 7-8 PM. TEMPS: GIVEN THE QUIET/NEAR NORMAL PATTERN...USED A BLEND OF ALL GUIDANCE WITH BIAS CORRECTION FOR TNGT`S LOWS AND TUE`S HIGHS. DID LOWER TEMPS ANOTHER 3-5F TNGT FROM PLN-INDIAN RIVER-ATLANTA-MIO. TNGT: M/CLEAR. A FEW THIN SHREDS OF CIRRUS. LOWS /40-49F INLAND AND 50-56F ALONG THE COASTS/. DID SEE 39F THIS MRNG 15N OF ATLANTA. THIS PROBABLY REPEATS. SIGNIFICANTLY CUT BACK MENTION OF PATCHY F IN THE FCST. CROSS OVER TEMPS WILL BE APPROACHED ONLY IN CLIMATOLOGICAL COLDEST AREAS...NEAR CAD/GOV/HTL/ACB/PLN. TUE: ANOTHER FANTASTIC DAY. M/SUNNY WITH TEMP RECOVERY BACK TO NORMAL /74-80F EXCEPT COOLER IMMEDIATE LAKE MI COAST/. 850 TEMP OF +10 SUPPORTS 77F FOR HIGH TEMPS. LOW-LVL WINDS WILL REMAIN TOO STRONG FOR LAKE BREEZES ON THE LAKE HURON SIDE. WINDS WITHIN THE BOUNDARY LAYER EVEN OFFER G14-17 KTS WITH A ONE-TIME PEAK G20. BECAUSE OF THIS...REMOVED COOL BIAS ALONG THE COAST AND TOOK 78-80F ALL THE WAY TO SHORELINE. DO EXPECT LAKE BREEZE DEVELOPMENT OVER THE ERN U.P. AND NW LOWER MI...INCLUDING GT BAY AS SFC RIDGE AXIS MOVES INTO LAKE MI. DWPTS ARE BIAS CORRECTED BLEND OF ALL GUIDANCE WITH ANOTHER 25% BLEND WITH MET MOS TO LOWER SOME MORE AS DWPTS SHOULD BE AT LEAST AS LOW AS TODAY. MAV MOS NOT USED AS IT`S ~7F HIGHER THAN MET. STILL HAD TO TAKE FEW LOCATIONS DOWN ANOTHER 3-4F. LITTLE CHANGE IN TEMPS/DWPTS FROM 4 AM APX FCST. SO THREAT OF ELEVATED FIRE DANGER WILL BE MAINTAINED IN HWO. .LONG TERM.../ISSUED AT 346 PM/...WEDNESDAY AND BEYOND LARGE SCALE SYNOPSIS/FORECAST: MODERATELY AMPLIFIED PATTERN ACROSS NORTH AMERICA...WITH A CLOSED LOW OFF THE OREGON/CALIFORNIA COAST...A CLOSED HIGH OVER THE CENTRAL PLAINS...AND TROUGHING OVER EASTERN CANADA AND THE NORTHEASTERN U.S....BIT OF A -NAO LOOK TO IT ALL. TROPICAL STORM "DEBBY" CONTINUES TO CHURN OVER THE NORTHEAST GULF OF MEXICO. AS UPPER LOW OFF THE WEST COAST OPENS UP AND ITS REMNANTS LIFT NORTHEAST...UPPER RIDGE AXIS EXPECTED TO "FOLD" OVER INTO THE GREAT LAKES REGION DURING THE LATTER HALF OF THE WEEK... ALLOWING WARM AIR TO RETURN TO MICHIGAN. FLOW THEN FLATTENS OUT HEADING INTO THE WEEKEND WITH SOME HEIGHT FALLS BACK INTO THE GREAT LAKES AND A RETURN TO MORE TYPICAL LATE JUNE/EARLY JULY TEMPERATURES. TUESDAY NIGHT THROUGH THURSDAY: DEEP LAYER RIDGING FORECAST TO BUILD INTO THE UPPER GREAT LAKES TUESDAY NIGHT INTO EARLY WEDNESDAY...ALONG WITH INCREASING WARM ADVECTION. MAY SEE SOME MID/HIGH LEVEL CLOUDS TUESDAY NIGHT WITH THE WARM AIR RETURN...BUT THERE IS A POCKET OF DRIER LOW LEVEL AIR FORECAST FROM MICHIGAN SOUTH/SOUTHWEST INTO THE MID MISSISSIPPI VALLEY WHICH SHOULD PRECLUDE MUCH ELSE FROM HAPPENING. WARM AIR CONTINUES TO SURGE INTO MICHIGAN WEDNESDAY...AHEAD OF A WEAK COLD FRONT ASSOCIATED WITH SHORT WAVE ENERGY/HEIGHT FALLS LIFTING NORTHEAST ACROSS SASKATCHEWAN/MANITOBA. THIS FRONT EXPECT TO LIE ACROSS THE UPPER MIDWEST/NORTHERN AND CENTRAL PLAINS WEDNESDAY...GETTING STRETCHED NORTHEAST-SOUTHWEST WITH TIME. THERE IS AN AXIS OF HIGHER LOW LEVEL THETA-E AIR AHEAD OF THE FRONT PUSHING EAST INTO WISCONSIN/WESTERN UPPER MICHIGAN WEDNESDAY...BUT THIS WILL BE CAPPED BY INCREASING MID LEVEL TEMPERATURES (+12C 700MB TEMPERATURES/1000-500MB THICKNESSES APPROACHING 579DM ACROSS LOWER MICHIGAN BY WEDNESDAY EVENING). SO APPEARS AS IF CONVECTION WILL HAVE A TOUGH TIME GETTING GOING...AND EXPECT A DRY FORECAST THROUGH WEDNESDAY NIGHT. HIGHS WEDNESDAY AFTERNOON WILL SURGE WELL INTO THE 80S...WITH FAIRLY WIDESPREAD LAKE BREEZE DEVELOPMENT ANTICIPATED. BY THURSDAY MORNING...COLD FRONT EXPECTED TO HAVE STRETCHED ITS WAY ACROSS WESTERN UPPER MICHIGAN/WISCONSIN. THURSDAY SHOULD BE NOTICEABLY MORE HUMID THAN WEDNESDAY WITH DEW POINTS CLIMBING INTO THE 60S. THE FRONT IS EXPECTED TO MOVE INTO NORTHERN MICHIGAN DURING PEAK HEATING...MAY BE SOME CLOUDS WITH THE BOUNDARY BUT ANTICIPATE THAT THE WARM MID LEVEL TEMPERATURES WILL KEEP A LID ON THINGS. WILL HAVE TO WATCH THIS POTENTIAL...NOT A SLAM DUNK THAT THURSDAY WILL BE COMPLETELY DRY WHEN DEALING WITH THIS MUCH POTENTIAL ENERGY. THURSDAY COULD BE A REALLY WARM DAY...THE ONE CAVEAT BEING POSSIBLE CLOUD COVER AS THE COLD FRONT APPROACHES (THAT OFTEN BITES US DURING POTENTIAL HEAT WAVES). STILL LIKE THE IDEA OF SOME AREAS IN NORTHERN LOWER REACHING OR ECLIPSING 90 DEGREES. DON`T THINK ANY RECORDS ARE IN JEOPARDY UNLESS THE SOO CAN REACH 90 (ANJ RECORD HIGH FOR THURSDAY 89/1971). EXTENDED FORECAST (FRIDAY THROUGH MONDAY): BY THE START OF THE EXTENDED PERIODS...UPPER RIDGE AXIS IS EXPECTED TO HAVE BEEN FLATTENED BY SHORT WAVE ENERGY MOVING ACROSS ONTARIO FRIDAY. THIS WILL BE ACCOMPANIED BY A PUSH OF COOLER AIR...WHICH SHOULD ARRIVE FRIDAY NIGHT INTO SATURDAY. NORTHWEST FLOW ALOFT THEN EXPECTED TO PERSIST INTO THE START OF NEXT WEEK...BUT NO MAJOR WEATHER SYSTEMS ON THE HORIZON AT THIS POINT. DAILY SPECIFICS...FRIDAY LOOKS DRY AND WARM...AND PERHAPS NOT QUITE AS HUMID AS THURSDAY WITH THE COLD FRONT EXPECTED TO BE SOUTH OF THE FORECAST AREA. MORE SEASONABLE TEMPERATURES ON SATURDAY...MAYBE A BIT WARMER SUNDAY BUT WILL GO DRY BOTH DAYS. WILL START THE NEW MONDAY FORECAST OUT DRY AS WELL WITH TEMPERATURES MID 70S TO MID 80S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 646 PM EDT MON JUN 25 2012 MAIN CONCERN OVERNIGHT IS THE LOWER CIGS THAT ARE MOVING DOWN THE EAST SHORE OF LAKE SUPERIOR AND INTO E UPPER. TIMING ON THE CLOUDS PUTS THEM AT PLN AROUND 08Z AND APN AROUND 09Z. WILL ALLOW FOR SOME TEMPO GROUPS THAT THERE WILL BE SOME MVFR CIGS. OTHERWISE, VFR WEATHER WILL PERSIST AT ALL FOUR TAF SITES...AS HIGH PRESSURE REMAINS IN CONTROL OVER THE WRN AND CENTRAL GREAT LAKES THROUGH TUESDAY. WINDS WILL REMAIN LIGHT. AFTER A MAINLY CLEAR NIGHT TONIGHT...ONLY A FEW DIURNAL CU CAN BE EXPECTED BY MIDDAY TUESDAY. && .MARINE.../ISSUED AT 346 PM/ TNGT: LOW END SCA`S ARE IN PROGRESS ON THE ST MARY`S RVR. GUSTINESS WILL DIMINISH EARLY THIS EVNG...SO SCA`S WILL EXPIRE AT 8 PM. WINDS WILL REMAIN NW OVER THE WATERS...AND INCREASE OVER LAKE HURON. EXPECT LOW-END 22-25 KT GUSTS TO DEVELOP THIS EVNG AND LAST THRU THE NGT. SCA WILL POST AT 4 PM FOR 5 NM E OF THE BRIDGE TO STURGEON POINT LIGHT. TUE: LOW-END SCA`S WILL CONTINUE THRU 5 PM FOR MUCH OF NE LOWER MI. SOME 4 FOOTERS ARE POSSIBLE ON THE OUTER NEARSHORE WATERS. ELSEWHERE...PRES RIDGE WILL MOVE INTO MI. SO LIGHT W WINDS WILL BECOME SW. NO HEADLINES FOR LAKE MI/WHITEFISH BAY/ST MARY`S RVR. TUE NGT-WED: HIGH PRES DEPARTS TO THE E WITH LIGHT WINDS BECOMING SW ON ALL NRN MI NEARSHORE WATERS. NO HEADLINES AS STABILITY INCREASES. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LHZ347- 348. LM...NONE. LS...NONE. && $$ UPDATE...JL SYNOPSIS...FEF/NTS SHORT TERM...JDH LONG TERM...JPB AVIATION...JL MARINE...JDH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
710 PM CDT WED JUN 27 2012 .UPDATE... 00Z AVIATION DISCUSSION ADDED BELOW. && .DISCUSSION... /ISSUED 354 PM CDT WED JUN 27 2012/ TONIGHT AND THURSDAY...SHARP UPPER LEVEL RIDGE AXIS WILL SHIFT OFF TO THE EAST TONIGHT INTO TOMORROW...IN CONJUNCTION WITH A COLD FRONT THAT WILL PASS OVER THE AREA OVERNIGHT. AHEAD OF AND ALONG THE SFC FRONT...DEEP MOISTURE IN CENTRAL AND EASTERN WI INTO WESTERN WI MAY BE TAPPED TO PRODUCE ISOLD SHWRS/TSTMS OVER THE NRN TIER OF THE MPX CWFA. THERE IS SOME DEBATE AS TO WHETHER THE PRECIP MAY ACTUALLY REACH THE GROUND...SO HAVE USED A MIXTURE OF 10-20 POPS WITH WORDING RANGING FROM SPRINKLES TO SHWRS/TSTMS. AS THE FRONT SLIPS PAST...WINDS WILL SHIFT TO NWLY AND THE UPPER FLOW WILL BECOME ZONAL. THIS WILL ALLOW DEWPOINTS TO DROP AND H5 HEIGHTS TO LESSEN...BRINGING IN SLIGHTLY COOLER AIR FOR THU. GRANTED...TEMPS WILL STILL BE WARM...RISING TO THE MID 80S TO ARND 90...BUT HEAT INDEX VALUES WILL ONLY TOP OUT IN THE LOW 90S TMRW. THEREFORE...ONCE THE HEAT ADVY IN EFFECT FOR THIS AFTN AND EVE EXPIRES...NO FURTHER HEAT ADVISORIES WILL BE REQUIRED. AS FOR PRECIP TMRW...A FEW BUCKLES IN THE UPPER FLOW MAY PRODUCE ISOLD SHWR/TSTMS TMRW BUT PROSPECTS FOR MEASURABLE PRECIP ARE QUITE LOW. THURSDAY NIGHT THROUGH SATURDAY...THE AFOREMENTIONED CDFNT WILL SETTLE OVER NRN IL...SRN IA AND SERN NE THRU SAT AFTN. SEVERAL WEAK WAVES OF LOW PRES WILL GLIDE OVER THE WOBBLING STNRY FNT THROUGH THE PERIOD...CAPABLE OF PRODUCING ISOLD TO SCTD SHWRS/TSTMS FRI THRU SAT. POPS ARE CAPPED AT 30 PERCENT AND MAINLY FOR SRN PORTIONS OF THE CWFA. WITH LITTLE CHANGE IN AIRMASS THROUGH THE PERIOD...INCLUDING A PRIMARILY ZONAL /WNW-ESE/ FLOW...WILL NOT LOOK FOR ANY SIGNIFICANT COOL DOWN THROUGH THE REST OF THIS WEEK. HIGHS WILL RANGE IN THE UPR 80S TO LWR 90S WITH LOWS GENERALLY 65-70. HEAT INDEX VALUES WILL REACH AS HIGH AS THE MID 90S. SUNDAY THROUGH TUESDAY...ANOTHER RIDGE OF HIGH PRES WILL APPROACH FROM THE W...SHIFTING THE STORM TRACK SLIGHTLY NORTH. THIS WILL RESULT IN SLIGHTLY WARMER TEMPERATURES...HIGHS CLOSE TO 90 IF NOT LOWER 90S...BUT ALSO ADDITIONAL CHCS FOR PRECIP AS SEVERAL LOW PRES CENTERS PUSH E ALONG THE RESIDUAL STNRY FRONT WOBBLING OVER THE AREA. NOT LOOKING FOR ANY SIGNIFICANT PRECIP NOR ANY STRONG HEATING...MAINLY LEADING TO HAZY...HOT AND HUMID SUMMER WX. && .AVIATION.../00Z TAF ISSUANCE/ FRONT STARTING OUT THIS PERIOD DRAPED ACROSS THE TWIN CITIES OVER TO RNH. WINDS WITHIN FRONTAL TROUGH LGT AND VFR WITH NW WINDS SETTING IN WELL BEHIND THE FRONT ACROSS WRN MN. A FEW ELEVATED SHRA/TSRA HAVE BEEN MOVING ACROSS THE AREA WITH THE FRONT. LOOKING AT RAP SOUNDINGS...IF ANY SORT OF LIFT CAN BE ACHIEVED AT 550 MB /14K FT/...THERE ARE A FEW HUNDRED JOULES OF CAPE TO WORK WITH...WHICH HAS BEEN ENOUGH TO SPARK THESE SHOWERS. NOT EXPECTING MUCH COVERAGE ON SHOWERS...SO HAVE CONTINUED TO LEAVE MENTION OUT OF TAFS. OTHER ISSUE THIS TAF PERIOD THAT IS A BIT HARDER TO GAGE IS THE EXPANDING AREA OF VFR/MVFR CIGS ACROSS WRN MN BEHIND THE FRONT. RAP/NAM HAVE A BEAT ON THESE CLOUDS...AND CURRENT TAFS TIMED THEM IN WELL. HOWEVER...WITH THIS SORT OF EXPANSION SEEN THIS EVENING...IS SOME CONCERN THAT A FAIR AMOUNT OF STRATUS COULD WORK THROUGH OVERNIGHT. AFTER ANY MORNING STRATUS/FOG BURNS OFF WILL BE NO ISSUES WITH THU AS NW WINDS OF 10KTS OR LESS SET IN WITH SKIES BECOMING SKC. KMSP...MOST DIFFICULT PART OF THIS FORECAST IS WHAT WILL HAPPEN WITH DEVELOPING CIGS OUT WEST. GIVEN HOW WIDESPREAD THEY HAVE BECOME...THINK WHAT HAS BEEN THE OVERZEALOUS GFS MAY ACTUALLY BE RIGHT THIS EVENING. KEPT CONDITIONS VFR...BUT DID INTRODUCE A LOWER VFR CIG. BASED ON CURRENT TRENDS...MAY SEE A FEW HOURS OF MVFR CONDITIONS BETWEEN 8Z AND 11Z...AS 00Z GFSLAMP INDICATES. BOTH NAM AND GFS HAVE THIS BAND OF CLOUDS EAST OF THE FIELD BY 12Z...WITH NO ISSUES EXPECTED THE REST OF THE WAY. /OUTLOOK/ .FRIDAY...VFR. WINDS S AT 5 TO 10KTS. .SATURDAY...VFR/MVFR WITH A SLIGHT CHANCE OF TSRA. WINDS LIGHT AND VARIABLE. .SUNDAY...VFR. WINDS NNW AT 5 TO 10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ANOKA-BLUE EARTH- BROWN-CARVER-DAKOTA-FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-LE SUEUR-MARTIN-MCLEOD-NICOLLET-RAMSEY-REDWOOD-RENVILLE-RICE- SCOTT-SIBLEY-STEELE-WASECA-WASHINGTON-WATONWAN. WI...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR PEPIN-PIERCE. && $$ JPC/MPG
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
653 PM CDT WED JUN 27 2012 .SHORT TERM... ISSUED AT 319 PM CDT WED JUN 27 2012 (TONIGHT) HOT AFTERNOON TEMPERATURES WILL FALL TO TOLERABLE LEVELS BY THURSDAY MORNING AS VERY DRY AIRMASS AND CLEAR SKIES ALLOW AN UNUSUALLY LARGE DIURNAL RANGE TO CONTINUE. FOLLOWING VERIFICATION FROM LAST NIGHT...HAVE GONE A FEW DEGREES BELOW MOS TEMPS. WINDS WILL DIMINISH AFTER SUNSET AS WELL. BROWNING && .LONG TERM... ISSUED AT 319 PM CDT WED JUN 27 2012 (FRIDAY-WEDNESDAY) UPPER RIDGE WILL REMAIN ENTRENCHED ACROSS THE REGION THROUGH THE END OF THE WORK WEEK AND INTO THE WEEKEND. WARMEST 850MB TEMPS I HAVE EVER SEEN WILL BE OVER THE AREA ON THURSDAY...AROUND 30C...SO WILL SEE OUR HOTTEST DAY OF THE WEEK TOMORROW. HIGHS WILL RANGE FROM 101 TO 108 ACROSS THE REGION WITH THE WARMEST TEMPS ALONG THE I-70 CORRIDOR. HOWEVER...DEWPTS WILL BE MID 50S FAR SOUTH TO MID 60S FAR NORTH...KEEPING HEAT INDICES CLOSER TO THE ACTUAL AIR TEMPERATURE. BUT WITH THE HEAT PERSISTING FOR THE NEAR FUTURE...AGREE THAT HEAT ADVISORY IS WELL WARRANTED FROM TOMORROW THROUGH SATURDAY AT THIS TIME. IF CONDITIONS PERSIST BEYOND THAT...WHICH LOOKS LIKELY...WILL NEED TO EXTEND ADVISORY AND/OR UPGRADE TO AN EXCESSIVE HEAT WARNING DUE TO THE DURATION OF THIS HEAT WAVE. IN THE MEANTIME...MODELS CONTINUE TO HAVE A WEAK FRONTAL BOUNDARY JUST TO THE NORTH OF THE FORECAST AREA. THIS WILL BE WHERE HIGHER DEWPTS POOL...THUS IT WILL BE A BIT MORE HUMID FOR OUR NORTHERN COUNTIES. AS FOR ANY PCPN...ANY ACTIVITY THAT DOES FIRE THROUGH THE WEEKEND WILL MORE THAN LIKELY JUST SKIM ALONG THE NORTHERN PERIPHERY...WITH PORTIONS OF THE AREA ONLY SEEING AN INCREASE IN CLOUD COVER. OTHERWISE...TEMPS ON FRIDAY AND SATURDAY WILL BE JUST A FEW DEGREES COOLER AS THERMAL RIDGE SHIFTS BACK TO OUR WEST AND NORTHWEST. HOWEVER...DEWPTS WILL BE A BIT HIGHER...IN THE UPPER 50S TO MID 60S...SO HEAT INDICES TO BE IN THE 100 TO 106 DEGREE RANGE. BEYOND THAT NO MAJOR CHANGES TO THE EXTENDED AS DRY AND HOT WEATHER PERSISTS THROUGH THE PERIOD. HIGHS WILL BE IN THE MID 90S TO NEAR 102 THROUGH NEXT WEDNESDAY...WITH THE COOLER TEMPS...IF YOU CAN CALL THEM THAT...IN THE NORTH NEAR THE STALLED OUT FRONTAL BOUNDARY. BYRD && .AVIATION... ISSUED AT 641 PM CDT WED JUN 27 2012 STILL NO SIGNIFICANT CLOUDS OR WEATHER IN THE OFFING FOR OUR AREA FOR THIS TAF PERIOD AS DOME OF HIGH PRESSURE REMAINS LOCKED OVER AREA. PRIMARY CONCERN TONIGHT IS THREAT OF LOW LEVEL WIND SHEAR. RUC AND NAM ARE BOTH VERY SIMILAR IN INCREASING LOW LEVEL JET WITH 1000FT WINDS RAMPING UP TO AROUND 40 KTS BEGINNING IN THE 05-08Z TIME FRAME...SO HAVE ADDED WIND SHEAR TO ALL LOCATIONS FOR THE OVERNIGHT AND PREDAWN HOURS. WINDS SHOULD BECOME WESTERLY BY THURSDAY MORNING...AND AS DAYTIME MIXING INCREASES EXPECTING GUSTS IN THE 15-20KT RANGE DURING LATE MORNAING AND INTO THE AFTERNOON. SPECIFICS FOR KSTL... VFR CONDITIONS WILL PERSIST WITH WINDS CONTINUING THEIR GRADUAL VEERING TREND....BECOMING WEST-SOUTHWEST BY LATE THURSDAY MORNING. BOTH RUC AND NAM ARE FORECASTING LOW LEVEL JET TO INCREASE TO AROUND 40KTS AT ONLY 1000FT AGL AFT 06Z...AND GIVEN RATHER LIGHT SURFACE WINDS DURING THIS TIME (AOB 7 KTS) HAVE INCLUDED LLWS FOR THE O8-15Z TIME FRAME. TRUETT && .FIRE WEATHER... ISSUED AT 319 PM CDT WED JUN 27 2012 DESPITE RELATIVE HUMIDITIES AT OR BELOW 25 PERCENT MOST LOCATIONS ON THURSDAY AND FRIDAY...WITH FUEL MOISTURES BELOW 9 PERCENT...THE WINDS WILL NOT BE QUITE STRONG ENOUGH TO WARRENT A RED FLAG WARNING FOR THE FORECAST AREA AT THIS TIME. SO WILL JUST MENTION ELEVATED FIRE DANGER THURSDAY AFTERNOON AND FRIDAY AFTERNOON IN THE HWO AND FIRE WEATHER PRODUCTS. BYRD && .CLIMATE... ISSUED AT 233 AM CDT SUN JUN 24 2012 RECORD HIGHS WEDNESDAY...THURSDAY AND FRIDAY DATE ST. LOUIS COLUMBIA QUINCY ---------------------------------------------- JUNE 27 104(1952) 101(1980) 102(1931) JUNE 28 104(1952) 103(1936) 104(1934) JUNE 29 105(1952) 104(1901) 103(1934) && .PRELIMINARY POINT TEMPS/POPS... ST LOUIS 72 108 79 104 / 0 0 0 5 QUINCY 74 104 75 100 / 0 0 10 10 COLUMBIA 69 107 73 103 / 0 0 0 5 JEFFERSON CITY 68 107 72 104 / 0 0 0 5 SALEM 65 105 71 103 / 0 0 0 5 FARMINGTON 65 105 70 102 / 0 0 0 0 && .LSX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY FROM NOON THURSDAY TO 7 PM CDT SATURDAY 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 FROM NOON THURSDAY TO 7 PM CDT SATURDAY 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 NC
1111 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 1100 PM WEDNESDAY...EXCELLENT RADIATIONAL COOLING CONDITIONS OVERNIGHT. WINDS HAVING DIMINISHED TO NEARLY CALM INLAND...EXCEPT REMAINING 2 TO 4 MPH ALONG THE IMMEDIATE BEACHES. A LAND BREEZE LIKELY WILL OCCUR ALONG THE IMMEDIATE COAST BY THU DAYBREAK WITH SSTS IN THE MID TO UPPER 70S AND LOWS AWAY FROM THE BEACHES IN THE UPPER 50S TO LOWER 60S...WITH DEWPOINTS MIMICKING TEMPS ESPECIALLY SEVERAL HRS LEADING TO SUNRISE. CURRENT MIN FORECAST IN LINE WITH ONLY TWEAKS UPWARD BY A DEGREE OR 2 NEEDED FOR THE BEACHES. SFC HIGH PRESSURE TO RIDGE ACROSS THE EASTERN CAROLINAS FROM ITS CENTER LOCATED OVER CENTRAL GEORGIA. NO POPS WITH A CLOUDLESS SKY ON TAP FOR THE ILM CWA TONIGHT. LITTLE MOISTURE IN THE ATM COLUMN VIA NEARBY 00Z RAOBS...WITH PWS LESS THAN 3/4 OF AN INCH. SUBSIDENCE ALOFT AND SOME SERIOUS CAPPING FROM 850MB AND UPWARDS...WITH INSTABILITY LACKING. && .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 1100 PM WEDNESDAY...SMALL CRAFT EXERCISE CAUTION ONLY IN EFFECT FOR THE SOUTHERNMOST WATERS FROM SOUTH OF MURRELLS INLET TO SOUTH SANTEE RIVER UNTIL 3 AM THU. LATEST BUOY AND COASTAL OBSERVATIONS INDICATE WINDS DIMINISHING NICELY IN CONCERT WITH THE LATEST HOURLY HRRR MODEL DATA. EXPECT NE-E WINDS TO DROP TO N AROUND 10 KT OVERNIGHT...AS A RESULT OF THE SFC PG RELAXING DUE TO THE SFC RIDGE AXIS EXTENDING FROM ITS CENTER OVER GA...MIGRATING ACROSS THE IMMEDIATE COAST. THERE IS A POSSIBILITY OF A WEAK LAND BREEZE NEAR SHORE...WITH WINDS FROM THE NW 5 TO 10 KT. SIGNIFICANT SEAS IN THE 2 TO 5 FT RANGE WILL DIMINISH TO 2 TO 4 FT THROUGHOUT DURING THE OVERNIGHT. THE LOCALLY PRODUCED WIND WAVE PORTION OF THE SIG SEAS WILL LOWER BUT THE S TO SE SWELL COMPONENT FROM WHATS LEFT OF DEBBY WILL CONTINUE. DOMINANT OVERNIGHT PERIODS WILL RUN AT 6 TO 8 SECONDS. 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...NONE. && $$ NEAR TERM...DCH SHORT TERM...RAN LONG TERM...MJC AVIATION...HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
800 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 800 PM WEDNESDAY...EXCELLENT RADIATIONAL COOLING CONDITIONS OVERNIGHT. WINDS DIMINISHING TO CALM INLAND AN HR OR 3 AFTER SUNSET EXCEPT REMAINING 2 TO 4 MPH ALONG THE BEACHES. A LAND BREEZE LIKELY WILL OCCUR ALONG THE IMMEDIATE COAST BY THU DAYBREAK WITH SSTS IN THE MID TO UPPER 70S AND LOWS AWAY FROM THE BEACHES IN THE UPPER 50S TO LOWER 60S...WITH DEWPOINTS MIMICKING TEMPS ESPECIALLY SEVERAL HRS LEADING TO SUNRISE. PREVIOUS DISCUSSION................................................. 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 800 PM WEDNESDAY...SMALL CRAFT EXERCISE CAUTION FOR THE WATERS SOUTH OF CAPE FEAR TO MURRELLS INLET THROUGH MIDNIGHT...AND SOUTH OF THE INLET TO SOUTH SANTEE RIVER TO 3 AM THURSDAY. LATEST BUOY AND COASTAL OBSERVATIONS INDICATE WINDS DIMINISHING NICELY IN CONCERT WITH THE LATEST HOURLY HRRR MODEL DATA. EXPECT NE-E WINDS TO DROP TO AROUND 10 KT BY DAYBREAK THURSDAY...AS A RESULT OF THE SFC PG RELAXING OVERNIGHT. WIND DIRECTIONS WILL BACK TO A NORTHERLY DIRECTION DUE TO A WEAK SFC RIDGE AXIS FROM A HIGH CENTERED OVER GA TOWARD DAYBREAK THU. COULD EVEN OBSERVE A WEAK LAND BREEZE NEAR SHORE WITH WINDS FROM THE NW 5 TO 10 KT. SIGNIFICANT SEAS IN THE 2 TO 5 FT RANGE WILL DIMINISH TO 2 TO 4 FT THROUGHOUT DURING THE OVERNIGHT. THE LOCALLY PRODUCED WIND WAVE PORTION OF THE SIG SEAS WILL LOWER BUT THE S TO SE SWELL FROM DEBBY WILL CONTINUE. DOMINANT OVERNIGHT PERIODS WILL RUN AT 6 TO 8 SECONDS. 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...NONE. && $$ NEAR TERM...DCH/JDW SHORT TERM...RAN LONG TERM...MJC AVIATION...HDL
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
755 PM CDT WED JUN 27 2012 .SHORT TERM...TONIGHT THROUGH SATURDAY 755 PM CDT WED JUN 27 2012 HAVE ISSUED ANOTHER HEAT ADVISORY FOR PORTIONS OF NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THURSDAY...NOON TO 8 PM. POOLING HIGH SFC TD WITH TEMPS TOPPING OUT IN THE MID TO LOW 90S WILL RESULT IN HEAT INDICES FROM 100 TO 105 DURING THE AFTERNOON. SFC FRONT WILL BE SLIDING SOUTHEAST OF THE FORECAST BY EARLY THU MORNING...BUT DRY AIR LAGS WELL BEHIND IT...GRADUALLY BRINGING RELIEF FROM THE HIGHER HUMIDITIES FROM NORTH TO SOUTH BY LATE AFTERNOON - EARLY EVENING. MEANWHILE...VERY THIN LINE OF ECHO DETECTED VIA 88-D RADAR IMAGERY MOVING EAST ACROSS NORTHWEST WI. VERY HIGH BASED AND APPEARS PARTIALLY DRIVEN BY THE LEADING EDGE OF A SHORTWAVE A LOFT TAPPING INTO ELEVATED INSTABILITY. DON/T EXPECT THIS TO LAST THAT LONG AFTER SUNDOWN...AND MOST OF THE PCPN IS NOT REACHING THE GROUND. MAY HAVE TO ADD SOME LOW CHANCE POPS ACROSS THE FAR NORTH FOR A COUPLE HOURS THOUGH. .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... 755 PM CDT WED JUN 27 2012 WI...HEAT ADVISORY FROM NOON TO 7 PM CDT THURSDAY FOR WIZ054-055-061. MN...NONE. IA...HEAT ADVISORY FROM NOON TO 7 PM CDT THURSDAY FOR IAZ029-030. && $$ SHORT TERM...RIECK LONG TERM....DAS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
318 PM CDT TUE JUN 26 2012 PLENTY TO CONSIDER INCLUDING POTENTIAL FOR HEAT HEADLINES...ASSESSING MODEL TEMPS/DEW POINTS AND VARIOUS MODEL SOLUTIONS FOR PRECIP TRENDS. OVERALL...GIVEN THE PATTERN AND LACK OF SIGNIFICANT TRIGGERS AND WEAK NATURE OF FRONTAL BOUNDARIES...HARD TO GET EXCITED ABOUT ANY DROUGHT BUSTING RAINS...SO LEANING MORE TOWARDS THE ECMWF SOLUTION. HOWEVER GFS AND GEM OFFER SOME HOPE FOR SOME MUCH NEEDED RAINS. HOPEFULLY THE LATTER SCENARIO CAN SOMEHOW COME TO FRUITION. S SEEING THE INITIALIZED ECMWF 500 MILLIBAR FLOW VERSUS THE 240 HOUR VALID 12Z/JULY 6TH DOES NOT EXACTLY GIVE MUCH HOPE FOR A PATTERN TO CHANGE FOR MUCH NEEDED RAINFALL. .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. && $$ TONIGHT/WEDNESDAY AND AVIATION/MARINE...MRC WEDNESDAY NIGHT THROUGH TUESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
343 AM EDT THU JUN 28 2012 .SYNOPSIS... ISSUED AT 343 AM EDT THU JUN 28 2012 HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE WEEKEND AND EARLY NEXT WEEK. THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY. THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD FRONT COMES INTO THE REGION. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN. ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS SHOULD BEGIN TO DROP. STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON... ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN. THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH TEMPS AROUND 90 AGAIN. A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY. THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W) BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE. WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE VERY HOT AIR SOUTH AND WEST OF HERE. THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20 PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1159 PM EDT WED JUN 27 2012 VFR THROUGH THE EVENING...BUT SOME MVFR IS POSSIBLE BY 12Z THURSDAY AS LOW LEVEL MOISTURE MOVES IN. SOME OF THE FORECAST GUIDANCE SHOWS IFR NEAR MKG AS THE MOIST AIR MOVES OVER LAKE MICHIGAN AND FORMS FOG AND LOW CLOUDS. DECIDED TO ADD THE IFR TO THE MKG FORECAST ALTHOUGH THIS SHOULD BE IMPROVING TO MVFR AFTER SUNRISE THURSDAY. && .MARINE... ISSUED AT 343 AM EDT THU JUN 28 2012 RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION. && .HYDROLOGY... ISSUED AT 343 AM EDT THU JUN 28 2012 IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR MIZ072>074. LM...NONE. && $$ SYNOPSIS...JK SHORT TERM...JK LONG TERM...WDM AVIATION...OSTUNO HYDROLOGY...JK MARINE...JK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
108 AM CDT THU JUN 28 2012 .UPDATE...KUEX INDICATES ISOLATED CONVECTIVE ACTIVITY DEVELOPING OVER PORTIONS OF NORTH CENTRAL KANSAS AND SOUTH CENTRAL NEBRASKA...PRIMARILY ALONG AND SOUTHEAST OF LINE FROM KK82 TO KHJH. RAP ANALYSIS INDICATES A 40-50KT 850MB JET STREAK EXISTS OVER THIS AREA WITH ISENTROPIC UPGLIDE PRESENT AROUND THE 310K SURFACE. RAP ANALYSIS PROXIMITY SOUNDINGS FROM OUR SOUTHEASTERN CWA SUGGEST A STRONG THERMAL INVERSION THROUGH ABOUT 800MB SHOULD KEEP CONVECTION ON THE WEAK SIDE. WENT AHEAD AND INTRODUCED SLIGHT CHANCE POPS TO OUR SOUTHEAST TO ACCOUNT FOR THIS ACTIVITY. && .PREV DISCUSSION... /ISSUED 1201 AM CDT THU JUN 28 2012/ AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS. DECAYING THUNDERSTORM ACTIVITY HAS PROMOTED AN AREA OF LOW LEVEL OUTFLOW WHICH IS APPROACHING KGRI FROM THE WEST. KUEX INDICATES THE LEADING EDGE OF THIS OUTFLOW WILL LIKELY INFILTRATE KGRI BETWEEN 05Z AND 06Z. THIS WILL PRESENT WEST/NORTHWESTERLY SURFACE WINDS 06-09Z...AT WHICH TIME SURFACE WINDS SHOULD BECOME MORE ESTABLISHED FROM THE NORTHEAST. HIGH LEVEL CLOUDS NEAR 20000FT AGL WILL BE POSSIBLE THROUGH MUCH OF THE TAF PERIOD. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS. PREV DISCUSSION... /ISSUED 1041 PM CDT WED JUN 27 2012/ UPDATE...UPDATED THE FORECAST TONIGHT TO CLEAN UP FIRE WEATHER/HEAT PRODUCTS AND TO INCLUDE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE NORTHWESTERN THIRD OF THE CWA TONIGHT ALONG AN NEAR AND NORTH OF AN ELEVATED FRONT AS A RIPPLE OF ENERGY MOVES BY. WE ARE SO CAPPED THAT ANY CONVECTION WILL STRUGGLE TO STAY TOGETHER. PREV DISCUSSION... /ISSUED 411 PM CDT WED JUN 27 2012/ SHORT TERM...TONIGHT THROUGH THURSDAY. AFTER STARTING OFF THE DAY RATHER WARM WITH READINGS WELL IN THE 70S THIS MORNING...TEMPERATURES HAVE SKY ROCKETED WELL INTO THE 90S...ALTHOUGH READINGS OVER 100F HAVE BEEN MORE OF THE NORM THIS AFTERNOON. KGRI HAS ALREADY REACHED A NEW RECORD HIGH OF 107 DEGREES...WITH THE PREVIOUS RECORD 105 DEGREES SET BACK IN 1936. THE ALL TIME JUNE RECORD HIGH FOR GRAND ISLAND IS 108 SET IN 1946 AND 1933...AND WE ARE EDGING CLOSER TO THAT...IT WILL BE CLOSE. THE DRY...HOT CONDITIONS HAVE ALSO BEEN CONDUCIVE FOR HAZARDOUS FIRE WEATHER CONDITIONS...ESPECIALLY IN OUR SOUTH AND EAST WHERE WINDS HAVE BEEN GUSTING BETWEEN 30 AND 40 MPH...AND A RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM. A FIRE/SMOKE PLUME WHICH ORIGINATED IN PHILLIPS COUNTY KANSAS WAS EVIDENT ON KUEX RADAR EARLY THIS AFTN. PATTERN ALOFT REFLECTED AN UPPER LEVEL RIDGE OF HIGH PRESSURE ENTRENCHED ACROSS THE INTERIOR CONUS...WHILE A LOW PRESSURE SYSTEM TRACKED ACROSS SASKATCHEWAN. AT THE SURFACE...SUBTLE COOL FRONTAL BOUNDARY HAD EDGED FARTHER SOUTH INTO NEBRASKA AND EXTENDED FROM KMCK TO KBBW TO KONL. FRONTAL BOUNDARY WILL CONTINUE TO SAG SOUTH THIS EVENING AND TONIGHT AND STALL NEAR THE NEB/KS STATE LINE INTO NW KANSAS. STRONG CAP IS IN PLACE WITH MID LEVEL TEMPS AROUND 18C...WHICH ONLY COOL A COUPLE OF DEGREES IN OUR NORTH TONIGHT. SOME CONCERN THAT CONVECTION WHICH DEVELOPS ALONG THE FRONT RANGE/HIGH PLAINS MAY WORK TOWARDS OUR WESTERN CWA LATE TONIGHT...BUT CONFIDENCE IS RATHER LOW WITH STRONG CAP AND WILL KEEP THINGS DRY...OR JUST SILENT POPS. NOSE OF LLVL JET FOCUSES TOWARDS THE MISSOURI RIVER TONIGHT AND COULD SEE CONVECTION ATTEMPT TO DEVELOP TOWARD DAYBREAK AROUND OUR NORTHEAST ZONES BUT AGAIN CONFIDENCE IS NOT HIGH AND WILL LEAVE FCST DRY ATTM. HEAT IS ANOTHER BIG CONCERN FOR SEVERAL UPCOMING DAYS. KANSAS ZONES ARE FORECAST AOA THE CENTURY MARK THROUGH THE REMAINDER OF THE WEEK AND WILL CONVERT THE CURRENT HEAT ADVISORY TO AN EXCESSIVE HEAT WARNING THROUGH 02Z SATURDAY. THIS AREA HAS SEEN SEVERAL DAYS WITH HEAT ADVISORY CONDITIONS WITH LITTLE REPRIEVE EXPECTED. INTO SOUTH CENTRAL NEBRASKA...HEAT ADVISORY CONDITIONS ARE A LITTLE MORE MARGINAL FOR THURSDAY AND WILL BE DEPENDENT UPON FRONTAL BOUNDARY WHICH THE NAM STALLS AND THE GFS WASHES OUT. ATTM...WILL BUFFER THE NC KS EXCESSIVE HEAT WARNING WITH A HEAT ADVISORY EDGING NORTH TO HIGHWAY IN PORTIONS OF SOUTH CENTRAL NEBRASKA. THE HEADLINE CHANGES SHOULD BE A GOOD STARTING PLACE FOR WHAT STILL LOOKS LIKE A PROLONGED HEAT EVENT FOR THE CENTRAL PLAINS BASED ON EXTENDED FORECAST MODELS. FRONTAL BOUNDARY MEANDERING OR WASHING OUT THURSDAY WILL RESULT IN LESS WIND FOR OUR REGION AND WIND SPEEDS WILL BE BELOW CRITERIA FOR A FIRE WEATHER HEADLINE. LONG TERM...THURSDAY EVENING THROUGH NEXT WEDNESDAY. AS WAS THE CASE YESTERDAY...OVERALL FEW NOTABLE CHANGES WERE MADE TO THE FORECAST FOR THE DAYS 3-7 PERIOD. THIS MEANS THAT HIGHLY QUESTIONABLE BUT NONETHELESS POSSIBLE THUNDERSTORM CHANCES CONTINUE MAINLY IN THE THURS NIGHT THROUGH SAT NIGHT TIME FRAME...ALONG WITH WELL-ABOVE NORMAL TEMPERATURES. FOR A BIT MORE INSIGHT TO THE POTENTIAL HISTORICAL SIGNIFICANCE OF THIS EARLY SUMMER HEAT...PLEASE SEE THE SEPARATE CLIMATE SECTION BELOW...AND FOR MORE INSIGHT ON THE HEAT HEADLINES ONGOING THROUGH THURSDAY OR FRIDAY...PLEASE SEE THE SHORT TERM SECTION ABOVE. STARTING WITH THURSDAY EVENING/NIGHT...CONTINUED TO BLANKET THE CWA WITH 20-30 PERCENT STORM CHANCES...ALTHOUGH CONFIDENCE IN MOST AREAS SEEING ANYTHING IS QUITE LOW GIVEN CONSIDERABLE CAPPING EVIDENCED BY 700MB TEMPS IN THE +13-15C RANGE. THAT BEING SAID...BOTH THE 18Z NAM/12Z GFS ADVERTISE THE DEVELOPMENT OF STORMS ACROSS PARTS OF THE CWA...MAINLY NORTH OF THE EAST-WEST SURFACE FRONT DRAPED NEAR THE STATE LINE...AND WITHIN A MODEST BUT EVIDENT EXIT REGION OF THE LOW LEVEL JET. IF STORMS DO MANAGE TO AFFECT SOME AREAS...IT COULD BE A COMBINATION OF ACTIVITY DEVELOPING OVERHEAD...AND STORMS POSSIBLY ROLLING EAST OFF THE HIGH PLAINS. ALTHOUGH ANY STORMS SHOULD REMAIN ELEVATED DUE TO CONSIDERABLE LOW LEVEL CAPPING...A STRONG TO SEVERE STORM IS NOT COMPLETELY OUT OF THE QUESTION IF PARCELS CAN TAKE ADVANTAGE OF A FEW THOUSAND J/KG OF ELEVATED CAPE IN THE PRESENCE OF POSSIBLY 25-30KT OF DEEP LAYER SHEAR. THIS THINKING IS CONSISTENT WITH THE TOKEN 5 PERCENT SEVERE PROBABILITIES ON THE LATEST SPC DAY 2 OUTLOOK. FOR THE FRIDAY THROUGH SUNDAY TIME FRAME...BOTH THE 12Z ECMWF/GFS ARE IN DECENT AGREEMENT ON THE LARGER SCALE PICTURE...WITH THE CWA REMAINING ALONG THE NORTHERN PERIPHERY OF THE DOMINANT SOUTHERN CONUS RIDGE. ALTHOUGH PERIODIC...MAINLY WEAK SHORTWAVES WILL RIPPLE THROUGH THE QUASI-ZONAL MID LEVEL FLOW...CAPPING TO SURFACE OR NEAR SURFACE BASED PARCELS WILL REMAIN QUITE STRONG WITH 700MB LEVEL TEMPS CONTINUING TO AVERAGE IN THE +13-15 TERRITORY. ALTHOUGH THE DEVELOPMENT OF STORMS IN ANY GIVEN PERIOD IS STILL HIGHLY QUESTIONABLE...WE HAVE BEEN CARRYING TOKEN SLIGHT STORM CHANCES OVER THE WEEKEND FOR AT LEAST A FEW DAYS NOW...AND JUST DON/T HAVE THE CONFIDENCE OR HEART TO PULL THEM OUT OF ANY GIVEN PERIOD YET. TEMP WISE...MADE SLIGHT UPWARD ADJUSTMENTS TO HIGHS FRIDAY-SUNDAY...WITH MID-UPPER 90S PREVALENT IN NEB ZONES...AND 100-110 IN KS. FOR SUNDAY NIGHT THROUGH WEDNESDAY...THERE IS NO RAIN MENTION IN THE FORECAST AT THIS TIME...AS THE GFS AND ESPECIALLY THE ECMWF ADVERTISE THE NORTHWARD EXPANSION OF THE SOUTHERN CONUS RIDGE...WITH THE CENTER OF THE MID LEVEL CLOCKWISE CIRCULATION RIGHT BACK OVER/VERY NEAR THE CENTRAL PLAINS BY MID WEEK. THIS SHOULD RESULT IN A SIMILAR SETUP TO THE PAST FEW DAYS...WITH PLENTY OF LOW LEVEL CAPPING TO CONVECTIVE CHANCES...AND VERY WARM TEMPERATURES. FOR NOW...HAVE STUCK WITH THE ALLBLEND MODEL CONSENSUS WITH HIGH TEMPS MONDAY-WEDNESDAY MAINLY UPPER 90S IN NEB ZONES AND 100-105 IN KANSAS...BUT COULD EASILY FORESEE THESE VALUES BEING 5+ DEGREES HIGHER THAN CURRENTLY ADVERTISED ON SOME DAYS IF THE RIDGE BECOMES AS DOMINANT AS CURRENTLY PROGGED. FIRE WEATHER...BESIDES THE ONGOING RED FLAG WARNING FOR THE SOUTHERN 1/2 OF THE CWA IN EFFECT THROUGH THIS EVENING...THE NEXT BEST CANDIDATE FOR POSSIBLY REACHING RED FLAG WARNING CRITERIA OF RH LESS THAN 20 PERCENT AND WINDS OF 20 MPH IS FRIDAY AFTERNOON/EARLY EVENING...MAINLY IN KS COUNTIES. THIS IS DUE TO INCREASING SOUTHERLY WINDS AS THE SURFACE FRONT LIFTS BACK NORTH. WITH THIS STILL BEING TWO DAYS AWAY...AND THE DETAILS STILL A BIT UNCLEAR MAINLY REGARDING WIND SPEEDS...WILL HOLD OFF FOR NOW ON ANY FIRE WEATHER WATCH HEADLINES BUT THIS WILL BE SOMETHING TO KEEP AN EYE ON. CLIMATE...ALTHOUGH IT WILL BE SEVERAL DAYS BEFORE THE HISTORICAL SIGNIFICANCE OF THIS EARLY SUMMER HEAT IS FULLY KNOWN...THIS IS UNDOUBTEDLY ONE OF THE HOTTEST STRETCHES OF LATE JUNE-EARLY JULY WEATHER EXPERIENCED IN SEVERAL YEARS. FOCUSING SPECIFICALLY ON GRAND ISLAND FOR THE 10-DAY PERIOD JUNE 26-JULY 5...FORECAST HIGHS FOR THE NEXT SEVERAL DAYS WOULD RESULT IN A DAILY AVERAGE TEMPERATURE DURING THIS STRETCH AROUND 98 DEGREES. THE LAST TIME THE PERIOD JUNE 26-JULY 5 YIELDED AN AVERAGE DAILY HIGH NEAR 98 DEGREES WAS IN 1991. THE LAST TIME A 10 DAY STRETCH AT ANY POINT IN THE SUMMER YIELDED AN AVERAGE HIGH OF 98 DEGREES WAS BETWEEN JULY 7-16, 1995. FOR LOCATIONS FARTHER SOUTH INTO NORTH CENTRAL KANSAS THAT ARE MORE ACCUSTOMED TO TOPPING 100 DEGREES...THIS APPEARS TO BE THE HOTTEST 10-DAY STRETCH SINCE AT LEAST AUGUST 2000. AGAIN THOUGH...THESE COMPARISONS ARE ALL DEPENDENT ON HOW WELL THE CURRENT FORECAST VERIFIES OVER THE NEXT WEEK OR SO. NO MATTER WHAT...PARTS OF THE CWA COULD POTENTIALLY BE IN A CATEGORY D3 SEVERE DROUGHT DESIGNATION FROM THE U.S. DROUGHT MONITOR WITHIN THE NEXT 1-2 WEEKS IF THIS WEATHER PATTERN PERSISTS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR NEZ074>077-082>087. KS...EXCESSIVE HEAT WARNING UNTIL 9 PM CDT FRIDAY FOR KSZ005>007- 017>019. && $$ 110 AM UPDATE/AVIATION...BRYANT 1041 PM UPDATE...HEINLEIN SHORT TERM...FAY LONG TERM/FIRE WEATHER/CLIMATE...PFANNKUCH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
129 AM EDT THU JUN 28 2012 .SYNOPSIS... AS SURFACE 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 130 AM THURSDAY...TWEAKED OVERNIGHT TEMPERATURES DOWN SLIGHTLY ESPECIALLY NEAR THE COAST WHERE OFFSHORE WINDS AT THE BEACHES (LANDBREEZE) WILL NEGATE ANY MARINE INFLUENCE. NORTH MYRTLE BEACH AND GEORGETOWN MAY GET AS COLD AS ANY OF OUR INTERIOR LOCATIONS TONIGHT. OTHERWISE NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS... EXCELLENT RADIATIONAL COOLING CONDITIONS OVERNIGHT. WINDS HAVING DIMINISHED TO NEARLY CALM INLAND...EXCEPT REMAINING 2 TO 4 MPH ALONG THE IMMEDIATE BEACHES. A LAND BREEZE LIKELY WILL OCCUR ALONG THE IMMEDIATE COAST BY THU DAYBREAK WITH SSTS IN THE MID TO UPPER 70S AND LOWS AWAY FROM THE BEACHES IN THE UPPER 50S TO LOWER 60S...WITH DEWPOINTS MIMICKING TEMPS ESPECIALLY SEVERAL HRS LEADING TO SUNRISE. CURRENT MIN FORECAST IN LINE WITH ONLY TWEAKS UPWARD BY A DEGREE OR 2 NEEDED FOR THE BEACHES. SFC HIGH PRESSURE TO RIDGE ACROSS THE EASTERN CAROLINAS FROM ITS CENTER LOCATED OVER CENTRAL GEORGIA. NO POPS WITH A CLOUDLESS SKY ON TAP FOR THE ILM CWA TONIGHT. LITTLE MOISTURE IN THE ATM COLUMN VIA NEARBY 00Z RAOBS...WITH PWS LESS THAN 3/4 OF AN INCH. SUBSIDENCE ALOFT AND SOME SERIOUS CAPPING FROM 850MB AND UPWARDS...WITH INSTABILITY LACKING. && .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 /06Z THURSDAY THROUGH MONDAY/... AS OF 06Z...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. CALM WINDS THIS MORNING WILL GIVE WAY TO A SOUTHWESTERLY WIND AFTER DAYBREAK AS A SURFACE HIGH CENTERED OVER FLORIDA DOMINATES THE WEATHER. THE COASTAL TERMINALS WILL LIKELY SEE A SOUTH SOUTHWEST MARINE SEABREEZE THIS AFTERNOON... PERHAPS WITH SOME 15-18 KT GUSTS AT MYR AND CRE. EXTENDED OUTLOOK...EXPECT VFR...BUT WITH EXTREMELY HOT TEMPERATURES EXPECTED THROUGH THE WEEKEND. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 AM THURSDAY...NO SIGNIFICANT CHANGES TO THE FORECAST AS WIND/SEA OBSERVATIONS MATCH THE LAST FORECAST. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS... SMALL CRAFT EXERCISE CAUTION ONLY IN EFFECT FOR THE SOUTHERNMOST WATERS FROM SOUTH OF MURRELLS INLET TO SOUTH SANTEE RIVER UNTIL 3 AM THU. LATEST BUOY AND COASTAL OBSERVATIONS INDICATE WINDS DIMINISHING NICELY IN CONCERT WITH THE LATEST HOURLY HRRR MODEL DATA. EXPECT NE-E WINDS TO DROP TO N AROUND 10 KT OVERNIGHT...AS A RESULT OF THE SFC PG RELAXING DUE TO THE SFC RIDGE AXIS EXTENDING FROM ITS CENTER OVER GA...MIGRATING ACROSS THE IMMEDIATE COAST. THERE IS A POSSIBILITY OF A WEAK LAND BREEZE NEAR SHORE...WITH WINDS FROM THE NW 5 TO 10 KT. SIGNIFICANT SEAS IN THE 2 TO 5 FT RANGE WILL DIMINISH TO 2 TO 4 FT THROUGHOUT DURING THE OVERNIGHT. THE LOCALLY PRODUCED WIND WAVE PORTION OF THE SIG SEAS WILL LOWER BUT THE S TO SE SWELL COMPONENT FROM WHATS LEFT OF DEBBY WILL CONTINUE. DOMINANT OVERNIGHT PERIODS WILL RUN AT 6 TO 8 SECONDS. 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...NONE. && $$ NEAR TERM...DCH/TRA SHORT TERM...RAN LONG TERM...MJC AVIATION...HDL/TRA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
246 AM CDT THU JUN 28 2012 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT 246 AM CDT THU JUN 28 2012 MAIN FORECAST CONCERNS ARE ON HEAT INDEX VALUES TODAY ALONG WITH SHOWER AND THUNDERSTORM CHANCES. FOCUS THEN TURNS TO TEMPERATURES AND SHOWER/THUNDERSTORM CHANCES THROUGH THE WEEKEND. LATEST SURFACE OBSERVATIONS SHOWED A WEAK COLD FRONT EXTENDING FROM EASTERN LAKE SUPERIOR TO FAR NORTHWEST WISCONSIN...INTO EXTREME NORTHWEST IOWA...DRIFTING SOUTHEAST. THE COLD FRONT WILL CONTINUE DRIFTING SOUTHEAST INTO THE FORECAST AREA TODAY. MEANWHILE...A SHORTWAVE TROUGH IS EXPECTED TO PUSH FROM WEST TO EAST ACROSS THE REGION. THE SHORTWAVE MAY TRIGGER A FEW ELEVATED SHOWERS AND THUNDERSTORMS AS IT MOVES THROUGH. THE WAVE IS ALREADY PRODUCING SOME SCATTERED SHOWERS AND STORMS OVER FAR WESTERN IOWA AND SOUTHWEST MINNESOTA. NORTHEAST IOWA AND SOUTHEAST MINNESOTA HAVE THE HIGHEST CHANCES OF SEEING THIS ACTIVITY THIS MORNING. THE HIGHEST CHANCES FOR SHOWERS AND STORMS THEN SHIFT SOUTH THIS AFTERNOON ACROSS EXTREME NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN. AFTERNOON MUCAPE VALUES ARE EXPECTED TO INCREASE INTO THE 2500-5500 J/KG RANGE. THESE CAPE VALUES COUPLED WITH 0-6 KM BULK SHEAR OF 40 TO 55 KTS COULD LEAD TO A FEW SEVERE THUNDERSTORMS. THE MAJOR LIMITING FACTOR WILL BE A STRONG CAP IN PLACE WITH CIN VALUES AROUND NEGATIVE 200 J/KG. IF THE CAP CAN BE BROKEN SEVERE STORMS WOULD BE A POSSIBILITY. THINKING THE BULK OF THE THUNDERSTORM ACTIVITY WILL BE ABOVE THE CAP...WITH LIMITED INSTABILITY TO WORK WITH. ANOTHER HOT AND HUMID DAY IS IN STORE ACROSS PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. WILL MAINTAIN HEAT ADVISORY ACROSS THESE AREAS FROM NOON TO 7 PM. PLAN ON HIGHS RANGING FROM THE UPPER 80S ACROSS NORTH CENTRAL WISCONSIN TO THE LOWER TO MID 90S ACROSS PORTIONS NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN. THE FRONTAL BOUNDARY IS EXPECTED TO PUSH INTO CENTRAL IOWA/NORTHERN ILLINOIS TONIGHT AND WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT. WEAK HIGH PRESSURE WILL PUSH INTO THE FORECAST AREA BEHIND THE BOUNDARY. IT WILL TAKE SOME TIME FOR DRIER AIR TO MOVE IN WITH DEW POINTS SLOWLY FALLING THROUGH THE AFTERNOON INTO THE EVENING HOURS. A WEAK SHORTWAVE TROUGH LOOK TO MOVE ACROSS IOWA INTO NORTHERN ILLINOIS TONIGHT....TRIGGERING SHOWERS AND THUNDERSTORMS. A FEW OF THESE STORMS COULD EDGE INTO PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN SO WILL KEEP SHOWER AND THUNDERSTORM CHANCES ACROSS THESE AREAS. PLAN ON LOWS TONIGHT RANGING FROM THE MID 60S ACROSS NORTH CENTRAL WISCONSIN TO AROUND 70 OVER NORTHEAST IOWA. THE UPPER LEVEL RIDGE WILL FLATTEN AND SHIFT EAST OF THE REGION WITH ZONAL FLOW IN PLACE ACROSS THE REGION TONIGHT INTO EARLY FRIDAY MORNING. RATHER WARM AIR WILL REMAIN IN PLACE ACROSS THE REGION FRIDAY...PERSISTING THROUGH THE WEEKEND. 850 MB TEMPERATURES ONLY FALL SLIGHTLY BEHIND THE FRONT INTO THE 20 TO 22 C RANGE. 850 MB TEMPERATURES HOLD NEARLY STEADY THROUGH SATURDAY. WEAK EMBEDDED SHORTWAVES...MOVING THROUGH THE ZONAL FLOW...WILL INTERACT WITH THE BOUNDARY FRIDAY THROUGH SATURDAY. THE BOUNDARY TRIES TO LIFT NORTH SLIGHTLY FRIDAY NIGHT INTO SATURDAY BUT CONVECTION OCCURRING ON THE NORTHERN FRINGE SHOULD HOLD IT TO THE SOUTH. THE STRONGEST WAVE LOOKS TO PUSH ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY SO WILL KEEP THE HIGHEST PRECIPITATION CHANCES DURING THIS TIME FRAME. PLAN ON CHANCES FOR SHOWERS AND THUNDERSTORMS SATURDAY INTO SUNDAY WITH HIGHS RANGING FROM THE MID 80S ACROSS NORTHERN WISCONSIN TO THE LOWER 90S OVER NORTHEAST IOWA. SHEAR PROFILES WILL REMAIN FAVORABLE FOR A FEW STRONG TO POSSIBLY SEVERE THUNDERSTORMS WITH 0-6 KM BULK SHEAR IN THE 25 TO 35 KT RANGE. .LONG TERM...SUNDAY THROUGH WEDNESDAY 246 AM CDT THU JUN 28 2012 28.00 MEDIUM RANGE FORECAST MODELS CONTINUE TO SHOW UPPER RIDGING ATTEMPTING TO BUILD INTO THE UPPER MISSISSIPPI RIVER VALLEY LATE SUNDAY INTO MONDAY. HOWEVER...WEAK EMBEDDED SHORTWAVES LOOK TO ROTATE THROUGH THE RIDGE AS IT TRIES TO BUILD IN. THE MODELS ARE IN VERY GOOD AGREEMENT MONDAY NIGHT INTO TUESDAY SHOWING A STRONGER SHORTWAVE MOVING THROUGH THE FORECAST AREA BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS WITH IT. 850 MB TEMPERATURES CONTINUE TO HOLD IN THE 20 TO 22 C RANGE MONDAY THROUGH WEDNESDAY. PLAN ON THE SUMMER WARMTH PERSISTING THROUGH THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOWER 90S. THE PERIODIC SHOWER/THUNDERSTORM ACTIVITY COULD PRODUCE SOME BRIEF RELIEF FROM THE THE HEAT AT TIMES. OVERNIGHT LOWS WILL ONLY FALL INTO THE UPPER 60S TO LOWER 70S. && .AVIATION... 1105 PM CDT WED JUN 27 2012 COLD FRONT WILL TRACK SOUTHEAST ACROSS THE REGION OVERNIGHT... LIKELY MOVING THROUGH KRST NEAR 09Z AND KLSE 11Z. MOISTURE POOLING AROUND THE BOUNDARY COULD RESULT IN SOME SUB VFR CIGS...WHICH SOME MODELS ARE SUGGESTING. SOME 2500-3000 CLOUDS BEHIND THE BOUNDARY EVIDENCED BY LATEST SATELLITE IMAGERY AND SFC OBS. 28.00Z NAM12 AND LATEST RAP13 SUGGEST THAT MOISTURE WILL STAY POOLED IN THIS REGION...AND THAT THERE WOULD BE A PERIOD OF BKN025-035. WILL ADD A PERIOD OF BKN035 FOR NOW. IN ADDITION...LATEST HRRR CONTINUES TO POINT TO SOME CONVECTIVE POTENTIAL OVERNIGHT AS THE LOW LEVEL JET/MOISTURE TRANSPORT INTERACT WITH THE SFC BOUNDARY. NOT SOLD ON THIS...BUT CAN/T RULE IT OUT EITHER. NOT ENOUGH CONFIDENCE TO ADD TO THE TAFS HOWEVER. MVFR CIG/RAIN CHANCES WILL HAVE TO BE MONITORED THROUGH THE OVERNIGHT HOURS. && .ARX WATCHES/WARNINGS/ADVISORIES... 246 AM CDT THU JUN 28 2012 WI...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR WIZ054-055-061. MN...NONE. IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR IAZ029-030. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CDT WED JUN 27 2012 .SHORT TERM...TONIGHT THROUGH SATURDAY 755 PM CDT WED JUN 27 2012 HAVE ISSUED ANOTHER HEAT ADVISORY FOR PORTIONS OF NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THURSDAY...NOON TO 8 PM. POOLING HIGH SFC TD WITH TEMPS TOPPING OUT IN THE MID TO LOW 90S WILL RESULT IN HEAT INDICES FROM 100 TO 105 DURING THE AFTERNOON. SFC FRONT WILL BE SLIDING SOUTHEAST OF THE FORECAST BY EARLY THU MORNING...BUT DRY AIR LAGS WELL BEHIND IT...GRADUALLY BRINGING RELIEF FROM THE HIGHER HUMIDITIES FROM NORTH TO SOUTH BY LATE AFTERNOON - EARLY EVENING. MEANWHILE...VERY THIN LINE OF ECHO DETECTED VIA 88-D RADAR IMAGERY MOVING EAST ACROSS NORTHWEST WI. VERY HIGH BASED AND APPEARS PARTIALLY DRIVEN BY THE LEADING EDGE OF A SHORTWAVE A LOFT TAPPING INTO ELEVATED INSTABILITY. DON/T EXPECT THIS TO LAST THAT LONG AFTER SUNDOWN...AND MOST OF THE PCPN IS NOT REACHING THE GROUND. MAY HAVE TO ADD SOME LOW CHANCE POPS ACROSS THE FAR NORTH FOR A COUPLE HOURS THOUGH. .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... 1105 PM CDT WED JUN 27 2012 COLD FRONT WILL TRACK SOUTHEAST ACROSS THE REGION OVERNIGHT... LIKELY MOVING THROUGH KRST NEAR 09Z AND KLSE 11Z. MOISTURE POOLING AROUND THE BOUNDARY COULD RESULT IN SOME SUB VFR CIGS...WHICH SOME MODELS ARE SUGGESTING. SOME 2500-3000 CLOUDS BEHIND THE BOUNDARY EVIDENCED BY LATEST SATELLITE IMAGERY AND SFC OBS. 28.00Z NAM12 AND LATEST RAP13 SUGGEST THAT MOISTURE WILL STAY POOLED IN THIS REGION...AND THAT THERE WOULD BE A PERIOD OF BKN025-035. WILL ADD A PERIOD OF BKN035 FOR NOW. IN ADDITION...LATEST HRRR CONTINUES TO POINT TO SOME CONVECTIVE POTENTIAL OVERNIGHT AS THE LOW LEVEL JET/MOISTURE TRANSPORT INTERACT WITH THE SFC BOUNDARY. NOT SOLD ON THIS...BUT CAN/T RULE IT OUT EITHER. NOT ENOUGH CONFIDENCE TO ADD TO THE TAFS HOWEVER. MVFR CIG/RAIN CHANCES WILL HAVE TO BE MONITORED THROUGH THE OVERNIGHT HOURS. && .ARX WATCHES/WARNINGS/ADVISORIES... 755 PM CDT WED JUN 27 2012 WI...HEAT ADVISORY FROM NOON TO 7 PM CDT THURSDAY FOR WIZ054-055-061. MN...NONE. IA...HEAT ADVISORY FROM NOON TO 7 PM CDT THURSDAY FOR IAZ029-030. && $$ SHORT TERM...RIECK LONG TERM....DAS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
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
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
903 AM CDT THU JUN 28 2012 .DISCUSSION... 527 AM CDT HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING. AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE 9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH CLOUD BASES AT 11000 FT! 09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO... AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS. RATZER //PREV DISCUSSION... 400 AM CDT FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT. UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY. LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105 DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80 DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE 105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY. COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101 DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY. AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE. WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE DEVELOPS AND CAUSES SOME PROBLEMS. FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS. THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN. RATZER && .CLIMATE... 908 PM CDT ...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH... THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES FOR ROCKFORD ON THURSDAY. RECORD HIGHS FOR THURSDAY JUNE 28TH: CHICAGO: 101/1971 ROCKFORD:103/1934 ALL-TIME JUNE RECORD HIGHS: CHICAGO: 104...6/20/1988. ROCKFORD: 106...6/1/1934. ALL-TIME RECORD HIGHS: CHICAGO: 105...7/24/1934 ROCKFORD: 112...7/14/1936 MDB/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * WIND SHIFTS/TIMING ASSOCIATED WITH COLD FRONT DROPPING SOUTH ACROSS TERMINALS THIS AFTERNOON. * LAKE BREEZE TURNING WINDS NORHTEASTERLY LATE THIS AFTERNOON OR THIS EVENING. * POTENTIAL FOR THUNDERSTORMS...WITH GREATEST THREAT ALONG AND JUST BEHIND COLD FRONT. BMD //DISCUSSION...UPDATED 12Z... THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE WIND FORECAST...IN PARTICULAR THE TIMING OF FRONTAL PASSAGE AND TIMING OF LAKE BREEZE DEVELOPMENT. A SECONDARY CONCERN WILL BE THE SMALL CHANCES FOR THUNDERSTORM DEVELOPMENT INVOF THE COLD FRONT. A DIFFUSE COLD FRONT IS SLOWLY SAGGED SEWD THROUGH THE UPPER MISSISSIPPI VALLEY AND IS EXPECTED TO MOVE INTO NWRN IL BY AROUND NOON. AS THE FRONTAL TROUGH APPROACHES THE REGION...THE PRESSURE GRADIENT ACROSS NRN IL/SRN LAKE MICHIGAN/NRN INDIANA WILL BECOME RATHER WEAK...FURTHER DECREASING THE CONTRAST OF TEMPERATURES AND WINDS ACROSS THE BOUNDARY AND EXPECT WINDS TO DECREASE. WITH VERY WARM CONDITIONS DEVELOPING AHEAD OF THE FRONT...COMBINED WITH THE DECREASING WINDS...IT SHOULD NOT BE TOO DIFFICULT TO DEVELOP A LAKE BREEZE WITH THE CONTRAST OF NEAR 100F TEMPERATURES INLAND AND THE MUCH COOLER LAKE MICHIGAN WATER. AS ALWAYS...THE CONCERN WILL MORE BE TIMING RATHER THAN THE LIKELIHOOD OF LAKE BREEZE DEVELOPMENT AND NELY FLOW SETTING UP OVER NERN IL AND NLY FLOW SETTING UP OVER NWRN IN. AT THIS POINT...WILL TIME THE LAKE BREEZE PUSHING INLAND AND PAST ORD/MDW IN THE 19-21Z TIMEFRAME. AS FOR THUNDERSTORM POTENTIAL...THE INCREASING HEAT AND HUMIDITY WILL LEAD TO A VERY UNSTABLE ENVIRONMENT AHEAD OF THE COLD FRONT...BUT WARM AIR TRANSPORT UNDER SWLY FLOW ALOFT WILL LEAD TO STRONG CAPPING AT 7KFT. THIS WILL INHIBIT CONVECTIVE DEVELOPMENT...THROUGH MUCH OF THE AFTERNOON. MODEL GUIDANCE SUGGESTS LITTLE WEAKENING TO THE CAP AND SINCE THE FRONTAL BOUNDARY IS VERY DIFFUSE...WITH WILL NOT BE MUCH LOW LEVEL FORCING. SO...WHILE CHANCES FOR THUNDERSTORM DEVELOPMENT IS NON- ZERO...WILL CARRY A DRY FORECAST AND MONITOR THE LOCAL ENVIRONMENT VERY CLOSELY THROUGH THE AFTERNOON AND EVENING HOURS. KREIN //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION TRENDS...FROM WSW THIS MORNING TO NE BY LATE AFTERNOON/EARLY EVENING...BUT LOW TO MEDIUM CONFIDENCE ON SPECIFIC TIMING OF WIND SHIFTS ASSOCD WITH FROPA AND LAKE BREEZE. * LOW CONFIDENCE ON TSRA IMPACTING TERMINALS THIS AFTERNOON/EVENING. BMD //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA. SATURDAY...VFR. CHANCE TSRA. SUNDAY...VFR. CHANCE TSRA EARLY. MONDAY...VFR. SLIGHT CHANCE TSRA. TUESDAY...VFR. SLIGHT CHANCE TSRA. WEDNESDAY...VFR. WX NIL. KREIN && .MARINE... 310 AM CDT A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023- ILZ032-ILZ033-ILZ039 UNTIL 8 PM THURSDAY. IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM THURSDAY. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
612 AM CDT THU JUN 28 2012 .DISCUSSION... 527 AM CDT HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING. AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE 9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH CLOUD BASES AT 11000 FT! 09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO... AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS. RATZER //PREV DISCUSSION... 400 AM CDT FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT. UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY. LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105 DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80 DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE 105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY. COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101 DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY. AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE. WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE DEVELOPS AND CAUSES SOME PROBLEMS. FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS. THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN. RATZER && .CLIMATE... 908 PM CDT ...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH... THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES FOR ROCKFORD ON THURSDAY. RECORD HIGHS FOR THURSDAY JUNE 28TH: CHICAGO: 101/1971 ROCKFORD:103/1934 ALL-TIME JUNE RECORD HIGHS: CHICAGO: 104...6/20/1988. ROCKFORD: 106...6/1/1934. ALL-TIME RECORD HIGHS: CHICAGO: 105...7/24/1934 ROCKFORD: 112...7/14/1936 MDB/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * FROPA TIMING THIS AFTERNOON AND PRECIP CHANCES ALONG FRONT. * POTENTIAL FOR LAKE BREEZE THIS AFTERNOON. KREIN //DISCUSSION...UPDATED 12Z... THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE WIND FORECAST...IN PARTICULAR THE TIMING OF FRONTAL PASSAGE AND TIMING OF LAKE BREEZE DEVELOPMENT. A SECONDARY CONCERN WILL BE THE SMALL CHANCES FOR THUNDERSTORM DEVELOPMENT INVOF THE COLD FRONT. A DIFFUSE COLD FRONT IS SLOWLY SAGGED SEWD THROUGH THE UPPER MISSISSIPPI VALLEY AND IS EXPECTED TO MOVE INTO NWRN IL BY AROUND NOON. AS THE FRONTAL TROUGH APPROACHES THE REGION...THE PRESSURE GRADIENT ACROSS NRN IL/SRN LAKE MICHIGAN/NRN INDIANA WILL BECOME RATHER WEAK...FURTHER DECREASING THE CONTRAST OF TEMPERATURES AND WINDS ACROSS THE BOUNDARY AND EXPECT WINDS TO DECREASE. WITH VERY WARM CONDITIONS DEVELOPING AHEAD OF THE FRONT...COMBINED WITH THE DECREASING WINDS...IT SHOULD NOT BE TOO DIFFICULT TO DEVELOP A LAKE BREEZE WITH THE CONTRAST OF NEAR 100F TEMPERATURES INLAND AND THE MUCH COOLER LAKE MICHIGAN WATER. AS ALWAYS...THE CONCERN WILL MORE BE TIMING RATHER THAN THE LIKELIHOOD OF LAKE BREEZE DEVELOPMENT AND NELY FLOW SETTING UP OVER NERN IL AND NLY FLOW SETTING UP OVER NWRN IN. AT THIS POINT...WILL TIME THE LAKE BREEZE PUSHING INLAND AND PAST ORD/MDW IN THE 19-21Z TIMEFRAME. AS FOR THUNDERSTORM POTENTIAL...THE INCREASING HEAT AND HUMIDITY WILL LEAD TO A VERY UNSTABLE ENVIRONMENT AHEAD OF THE COLD FRONT...BUT WARM AIR TRANSPORT UNDER SWLY FLOW ALOFT WILL LEAD TO STRONG CAPPING AT 7KFT. THIS WILL INHIBIT CONVECTIVE DEVELOPMENT...THROUGH MUCH OF THE AFTERNOON. MODEL GUIDANCE SUGGESTS LITTLE WEAKENING TO THE CAP AND SINCE THE FRONTAL BOUNDARY IS VERY DIFFUSE...WITH WILL NOT BE MUCH LOW LEVEL FORCING. SO...WHILE CHANCES FOR THUNDERSTORM DEVELOPMENT IS NON- ZERO...WILL CARRY A DRY FORECAST AND MONITOR THE LOCAL ENVIRONMENT VERY CLOSELY THROUGH THE AFTERNOON AND EVENING HOURS. KREIN KREIN //ORD AND MDW CONFIDENCE...UPDATED 12Z... * MEDIUM TO HIGH CONFIDENCE IN WINDS BECOMING NORTHEASTERLY LATER THURSDAY AFTERNOON...BUT LOWER CONFIDENCE IN THE TIMING. * LOW CONFIDENCE IN THUNDERSTORMS IMPACTING THE TERMINALS THURSDAY AFTERNOON AND EVENING. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA. SATURDAY...VFR. CHANCE TSRA. SUNDAY...VFR. CHANCE TSRA EARLY. MONDAY...VFR. SLIGHT CHANCE TSRA. TUESDAY...VFR. SLIGHT CHANCE TSRA. WEDNESDAY...VFR. WX NIL. KREIN && .MARINE... 310 AM CDT A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023- ILZ032-ILZ033-ILZ039...NOON THURSDAY TO 8 PM THURSDAY. IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...NOON THURSDAY TO 8 PM THURSDAY. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
537 AM CDT THU JUN 28 2012 .DISCUSSION... 527 AM CDT HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING. AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE 9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH CLOUD BASES AT 11000 FT! 09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO... AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS. RATZER && .PREV DISCUSSION... 400 AM CDT FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT. UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY. LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105 DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80 DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE 105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY. COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101 DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY. AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE. WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE DEVELOPS AND CAUSES SOME PROBLEMS. FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS. THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN. RATZER && .CLIMATE... 908 PM CDT ...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH... THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES FOR ROCKFORD ON THURSDAY. RECORD HIGHS FOR THURSDAY JUNE 28TH: CHICAGO: 101/1971 ROCKFORD:103/1934 ALL-TIME JUNE RECORD HIGHS: CHICAGO: 104...6/20/1988. ROCKFORD: 106...6/1/1934. ALL-TIME RECORD HIGHS: CHICAGO: 105...7/24/1934 ROCKFORD: 112...7/14/1936 MDB/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * FROPA TIMING THURSDAY AFTERNOON AND PRECIP CHANCES ALONG FRONT. * POTENTIAL FOR LAKE BREEZE THURSDAY AFTERNOON/EVENING. KREIN //DISCUSSION...UPDATED 06Z... THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE WIND FORECAST...IN PARTICULAR THE TIMING OF FRONTAL PASSAGE AND TIMING OF LAKE BREEZE DEVELOPMENT. A SECONDARY CONCERN WILL BE THE SMALL CHANCES FOR THUNDERSTORM DEVELOPMENT INVOF THE COLD FRONT. A DIFFUSE COLD FRONT IS SLOWLY SAGGED SEWD THROUGH THE UPPER MISSISSIPPI VALLEY AND IS EXPECTED TO MOVE INTO NWRN IL BY AROUND NOON. AS THE FRONTAL TROUGH APPROACHES THE REGION...THE PRESSURE GRADIENT ACROSS NRN IL/SRN LAKE MICHIGAN/NRN INDIANA WILL BECOME RATHER WEAK...FURTHER DECREASING THE CONTRAST OF TEMPERATURES AND WINDS ACROSS THE BOUNDARY AND EXPECT WINDS TO DECREASE. WITH VERY WARM CONDITIONS DEVELOPING AHEAD OF THE FRONT...COMBINED WITH THE DECREASING WINDS...IT SHOULD NOT BE TOO DIFFICULT TO DEVELOP A LAKE BREEZE WITH THE CONTRAST OF NEAR 100F TEMPERATURES INLAND AND THE MUCH COOLER LAKE MICHIGAN WATER. AS ALWAYS...THE CONCERN WILL MORE BE TIMING RATHER THAN THE LIKELIHOOD OF LAKE BREEZE DEVELOPMENT AND NELY FLOW SETTING UP OVER NERN IL AND NLY FLOW SETTING UP OVER NWRN IN. AT THIS POINT...WILL TIME THE LAKE BREEZE PUSHING INLAND AND PAST ORD/MDW IN THE 19-21Z TIMEFRAME. AS FOR THUNDERSTORM POTENTIAL...THE INCREASING HEAT AND HUMIDITY WILL LEAD TO A VERY UNSTABLE ENVIRONMENT AHEAD OF THE COLD FRONT...BUT WARM AIR TRANSPORT UNDER SWLY FLOW ALOFT WILL LEAD TO STRONG CAPPING AT 7KFT. THIS WILL INHIBIT CONVECTIVE DEVELOPMENT...THROUGH MUCH OF THE AFTERNOON. MODEL GUIDANCE SUGGESTS LITTLE WEAKENING TO THE CAP AND SINCE THE FRONTAL BOUNDARY IS VERY DIFFUSE...WITH WILL NOT BE MUCH LOW LEVEL FORCING. SO...WHILE CHANCES FOR THUNDERSTORM DEVELOPMENT IS NON- ZERO...WILL CARRY A DRY FORECAST AND MONITOR THE LOCAL ENVIRONMENT VERY CLOSELY THROUGH THE AFTERNOON AND EVENING HOURS. KREIN //ORD AND MDW CONFIDENCE...UPDATED 09Z... * LOW CONFIDENCE IN THUNDERSTORMS IMPACTING THE TERMINALS THURSDAY AFTERNOON AND EVENING. * MEDIUM TO HIGH CONFIDENCE IN WINDS BECOMING NORTHEASTERLY LATER THURSDAY AFTERNOON...BUT LOWER CONFIDENCE IN THE TIMING. KREIN //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... FRIDAY THROUGH SUNDAY...VFR. CHANCE OF TSRA. MONDAY...VFR. TUESDAY...VFR. SLIGHT CHANCE OF TSRA TUESDAY NIGHT. KJB && .MARINE... 310 AM CDT A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023- ILZ032-ILZ033-ILZ039...NOON THURSDAY TO 8 PM THURSDAY. IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...NOON THURSDAY TO 8 PM THURSDAY. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1023 AM CDT THU JUN 28 2012 .UPDATE... AT 15Z THE COLD FRONT RAN FROM THE NORTH SUBURBS OF KMKE...TO KEFT...TO THE NORTHERN PARTS OF KCID...TO THE NORTHERN SUBURBS OF KDSM. DEW POINTS ARE POOLING ALONG AND IMMEDIATELY BEHIND THE FRONT WITH A FEW MID 70S NOW BEING REPORTED. THE CURRENT HEAT HEADLINES WILL REMAIN AS IS FOR NOW. HOWEVER... ACHIEVING HEAT INDEX VALUES OF 100+ IN THE FAR NORTHWEST AND NORTH PARTS OF THE CWFA MAY NOT OCCUR. INCOMING OBSERVATIONS FOR 15Z INDICATE A FEW LOCATIONS EITHER AT OR VERY NEAR 100 FOR THE HEAT INDEX SOUTH OF THE FRONT. BASED ON WHAT OCCURRED LAST NIGHT AND EARLY THIS MORNING...THERE IS NO SUCH THING AS A CAP. THE QUESTION NOW IS WHAT WILL OCCUR LATER THIS AFTERNOON. NONLINEAR PROCESSES WILL BE DOMINATING THE SENSIBLE WX. THE ONE THING THAT IS KNOWN IS THAT ANY CONVECTION THAT OCCURS THIS AFTERNOON WILL LIKELY BE ELEVATED AND NOT SURFACE BASED. USING THE RAP AS A TREND...THE STRONG VORT MAX OVER NORTHWEST IOWA WILL MOVE EAST THROUGH THE AFTERNOON. 700MB OMEGAS SHOW STRONG LIFT DEVELOPING ACROSS THE FAR NORTHERN PARTS OF THE CWFA BY EARLY AFTERNOON FOLLOWED BY STRONG DOWNWARD MOTION BY LATE IN THE AFTERNOON. ANOTHER VORT MAX ASSOCIATED WITH THE DEVELOPING ACCAS FROM KSUX BACK INTO EASTERN NEBRASKA ARRIVES BY MID TO LATE AFTERNOON. CONVECTION SHOULD DEVELOP AROUND THE LEVEL OF THE LFC WHICH IS PROGGED TO BE ROUGHLY 700MB. SO...WILL CONTINUE WITH THE IDEA OF SCHC TO POSSIBLY LOW CHC POPS OVER ROUGHLY THE NORTHERN QUARTER TO THIRD OF THE CWFA DURING THE AFTERNOON BEHIND THE FRONT. THE AREA IN QUESTION IS ROUGHLY WHERE THE ACCAS CURRENTLY IS ON SATELLITE OVER THE NORTH THIRD OF THE CWFA. ..08.. && .AVIATION... COLD FRONT RUNNING FROM ROUGHLY KMKE...KEFT...KCID...KDSM AT 15Z/28. WIND SHIFT WITH FRONTAL PASSAGE WILL OCCUR IN THE NEXT FEW HOURS AT KMLI. VFR WX IS EXPECTED AT KCID/KMLI/KBRL THROUGH 00Z/29 AND LIKELY 06Z/29. AT KDBQ...VFR WX IS EXPECTED BUT THERE WILL BE A POTENTIAL FOR VCSH OR VCTS WITH VIRGA. CLOUD BASES SHOULD BE 4KFT OR HIGHER. IF CONVECTION WOULD IMPACT KDBQ BRIEF MVFR CONDITIONS MAY BE SEEN. IF PRECIPITATION HAS TROUBLE REACHING THE GROUND THEN THERE WOULD BE A POTENTIAL FOR A DRY MICROBURST AT KDBQ. ..08.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY 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...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 GRAND RAPIDS MI
1042 AM EDT THU JUN 28 2012 .SYNOPSIS... ISSUED AT 343 AM EDT THU JUN 28 2012 HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE WEEKEND AND EARLY NEXT WEEK. THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY. THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD FRONT COMES INTO THE REGION. && .UPDATE... ISSUED AT EDT THU JUN 28 2012 WILL BE EXPANDING THE HEAT ADVISORY TODAY TO INCLUDE THE ENTIRE FORECAST AREA. WE ARE BASING THIS ON RECORD/NEAR RECORD EXPECTED TEMPERATURES AND A LOT OF ONGOING OUTDOOR EVENTS. WILL TRY TO HAVE THE NPW PRODUCT OUT BY 11 AM. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN. ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS SHOULD BEGIN TO DROP. STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON... ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN. THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH TEMPS AROUND 90 AGAIN. A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY. THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W) BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE. WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE VERY HOT AIR SOUTH AND WEST OF HERE. THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20 PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 748 AM EDT THU JUN 28 2012 VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY AFTERNOON. IT IS POSSIBLE FROM LATE MORNING INTO EARLY THIS EVENING AN ISOLATED THUNDERSTORMS COULD IMPACT SOME OF THE TAF SITES. HOWEVER THE RISK IS RATHER LOW SO I PUT VCTS FOR NOW MOSTLY FROM 18Z TO 00Z FOR THE WESTERN TAFS AND 21Z TO 03Z FOR THE EASTERN TAF SITES. WINDS COULD BE GUSTY AND HAIL IS POSSIBLE WITH THE STRONGER THUNDERSTORMS. && .MARINE... ISSUED AT 343 AM EDT THU JUN 28 2012 RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION. && .HYDROLOGY... ISSUED AT 343 AM EDT THU JUN 28 2012 IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ037>040-043>046- 050>052-056>059-064>067-071>074. LM...NONE. && $$ UPDATE...TJT SYNOPSIS...JK SHORT TERM...JK LONG TERM...WDM AVIATION...WDM HYDROLOGY...JK MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
749 AM EDT THU JUN 28 2012 .SYNOPSIS... ISSUED AT 343 AM EDT THU JUN 28 2012 HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE WEEKEND AND EARLY NEXT WEEK. THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY. THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD FRONT COMES INTO THE REGION. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN. ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS SHOULD BEGIN TO DROP. STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON... ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN. THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH TEMPS AROUND 90 AGAIN. A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY. THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W) BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE. WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE VERY HOT AIR SOUTH AND WEST OF HERE. THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20 PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 748 AM EDT THU JUN 28 2012 VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY AFTERNOON. IT IS POSSIBLE FROM LATE MORNING INTO EARLY THIS EVENING AN ISOLATED THUNDERSTORMS COULD IMPACT SOME OF THE TAF SITES. HOWEVER THE RISK IS RATHER LOW SO I PUT VCTS FOR NOW MOSTLY FROM 18Z TO 00Z FOR THE WESTERN TAFS AND 21Z TO 03Z FOR THE EASTERN TAF SITES. WINDS COULD BE GUSTY AND HAIL IS POSSIBLE WITH THE STRONGER THUNDERSTORMS. && .MARINE... ISSUED AT 343 AM EDT THU JUN 28 2012 RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION. && .HYDROLOGY... ISSUED AT 343 AM EDT THU JUN 28 2012 IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR MIZ072>074. LM...NONE. && $$ SYNOPSIS...JK SHORT TERM...JK LONG TERM...WDM AVIATION...WDM HYDROLOGY...JK MARINE...JK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
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
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
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
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
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
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
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
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
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. RIP CURRENT RISK UNTIL 5 PM CDT THIS AFTERNOON FOR INZ003. MI...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ077>081. RIP CURRENT RISK UNTIL 6 PM EDT THIS EVENING FOR MIZ077. 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...MURPHY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1226 PM CDT THU JUN 28 2012 .AVIATION... MAINLY VFR WX SHOULD BE SEEN THROUGH 06Z/29 WITH HIGH DENSITY ALTITUDES POSSIBLE THROUGH 03Z/29. COLD FRONT RUNS FROM ABOUT KMKE TO KDSM. LOW CLOUDS ARND 2KFT AGL ARE DVLPG RIGHT BEHIND THE FRONT THAT MAY BRIEFLY CREATE AN MVFR CIG. POTENTIAL IS STILL THERE FOR VCSH/VCTS AT KDBQ WITH VIRGA BUT WAS NOT INCLUDED IN THE 18Z TAFS DUE TO LOW PROBABILITY. AFT 06Z/29 THE MODELS ARE HIGHLY MIXED IN SOLUTIONS. A TSRA COMPLEX MAY DVLP IN WESTERN IOWA AND MOVE EAST. THIS SCENARIO WAS LEFT OUT OF THE 18Z TAFS DUE TO UNCERTAINTY. ..08.. && .PREV DISCUSSION... /ISSUED 1023 AM CDT THU JUN 28 2012/ UPDATE... AT 15Z THE COLD FRONT RAN FROM THE NORTH SUBURBS OF KMKE...TO KEFT...TO THE NORTHERN PARTS OF KCID...TO THE NORTHERN SUBURBS OF KDSM. DEW POINTS ARE POOLING ALONG AND IMMEDIATELY BEHIND THE FRONT WITH A FEW MID 70S NOW BEING REPORTED. THE CURRENT HEAT HEADLINES WILL REMAIN AS IS FOR NOW. HOWEVER... ACHIEVING HEAT INDEX VALUES OF 100+ IN THE FAR NORTHWEST AND NORTH PARTS OF THE CWFA MAY NOT OCCUR. INCOMING OBSERVATIONS FOR 15Z INDICATE A FEW LOCATIONS EITHER AT OR VERY NEAR 100 FOR THE HEAT INDEX SOUTH OF THE FRONT. BASED ON WHAT OCCURRED LAST NIGHT AND EARLY THIS MORNING...THERE IS NO SUCH THING AS A CAP. THE QUESTION NOW IS WHAT WILL OCCUR LATER THIS AFTERNOON. NONLINEAR PROCESSES WILL BE DOMINATING THE SENSIBLE WX. THE ONE THING THAT IS KNOWN IS THAT ANY CONVECTION THAT OCCURS THIS AFTERNOON WILL LIKELY BE ELEVATED AND NOT SURFACE BASED. USING THE RAP AS A TREND...THE STRONG VORT MAX OVER NORTHWEST IOWA WILL MOVE EAST THROUGH THE AFTERNOON. 700MB OMEGAS SHOW STRONG LIFT DEVELOPING ACROSS THE FAR NORTHERN PARTS OF THE CWFA BY EARLY AFTERNOON FOLLOWED BY STRONG DOWNWARD MOTION BY LATE IN THE AFTERNOON. ANOTHER VORT MAX ASSOCIATED WITH THE DEVELOPING ACCAS FROM KSUX BACK INTO EASTERN NEBRASKA ARRIVES BY MID TO LATE AFTERNOON. CONVECTION SHOULD DEVELOP AROUND THE LEVEL OF THE LFC WHICH IS PROGGED TO BE ROUGHLY 700MB. SO...WILL CONTINUE WITH THE IDEA OF SCHC TO POSSIBLY LOW CHC POPS OVER ROUGHLY THE NORTHERN QUARTER TO THIRD OF THE CWFA DURING THE AFTERNOON BEHIND THE FRONT. THE AREA IN QUESTION IS ROUGHLY WHERE THE ACCAS CURRENTLY IS ON SATELLITE OVER THE NORTH THIRD OF THE CWFA. ..08.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY 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...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 DODGE CITY KS
257 PM CDT THU JUN 28 2012 ...UPDATE TO LONG TERM DISCUSSION... .SYNOPSIS... ISSUED AT 1222 PM CDT THU JUN 28 2012 AT 12Z THURSDAY AN UPPER LEVEL JET STREAK EXTENDED FROM EASTERN WYOMING INTO SOUTHWEST ONTARIO. THE CENTER OF THE 500MB HIGH THIS MORNING WAS LOCATED ACROSS MISSOURI. UPPER LEVEL RIDGE ACROSS THE CENTRAL UNITED STATES HAD WEEKEND AS ONE UPPER LEVEL TROUGH MOVES ACROSS EASTERN NEBRASKA AND WHAT APPEARS TO BE ANOTHER UPPER LEVEL SYSTEM STARTING TO MOVE INTO WESTERN COLORADO BASED ON 500MB THERMAL TROUGH AND WATER VAPOR LOOP. AN AREA OF TROPICAL MOISTURE EXTENDED FROM CENTRAL COLORADO INTO CENTRAL/EASTERN NEBRASKA. WARM 16C 700MB TEMPERATURES WERE LOCATED ACROSS WESTERN KANSAS WITH 700MB TEMPERATURES RANGING FROM 16 TO 17C EXTENDING NORTHEASTWARD INTO THE GREAT LAKES REGION. 700MB TEMPERATURES OF 17C WERE OBSERVED AT GREEN BAY WISCONSIN, ALPENA MICHIGAN, AND DETROIT MICHIGAN. 850MB TEMPERATURES OF THE MID TO UPPER 20S STRETCHED FROM THE PANHANDLE OF TEXAS INTO IOWA. AT THE SURFACE A SURFACE BOUNDARY WAS LOCATED ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS AT 12Z. && .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 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1222 PM CDT THU JUN 28 2012 MODEL SOUNDINGS INDICATING WHAT MOISTURE THERE IS PRESENT ACROSS WESTERN AND NORTH CENTRAL KANSAS WILL BE CONFINED ABOVE THE 12000 FT LEVEL LATE TODAY AND EARLY THIS EVENING. AS A RESULT VFR CONDITIONS ARE EXPECTED OVER THE NEXT 18 TO 24 HOURS. SOUTH/SOUTHWEST WINDS AT AROUND 15KTS WILL BACK MORE TO THE SOUTHEAST BY LATE DAY. && .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 / 10 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. && $$ SYNOPSIS...BURGERT SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
212 PM CDT THU JUN 28 2012 ...UPDATED SHORT TERM DISCUSSION... .SYNOPSIS... ISSUED AT 1222 PM CDT THU JUN 28 2012 AT 12Z THURSDAY AN UPPER LEVEL JET STREAK EXTENDED FROM EASTERN WYOMING INTO SOUTHWEST ONTARIO. THE CENTER OF THE 500MB HIGH THIS MORNING WAS LOCATED ACROSS MISSOURI. UPPER LEVEL RIDGE ACROSS THE CENTRAL UNITED STATES HAD WEEKEND AS ONE UPPER LEVEL TROUGH MOVES ACROSS EASTERN NEBRASKA AND WHAT APPEARS TO BE ANOTHER UPPER LEVEL SYSTEM STARTING TO MOVE INTO WESTERN COLORADO BASED ON 500MB THERMAL TROUGH AND WATER VAPOR LOOP. AN AREA OF TROPICAL MOISTURE EXTENDED FROM CENTRAL COLORADO INTO CENTRAL/EASTERN NEBRASKA. WARM 16C 700MB TEMPERATURES WERE LOCATED ACROSS WESTERN KANSAS WITH 700MB TEMPERATURES RANGING FROM 16 TO 17C EXTENDING NORTHEASTWARD INTO THE GREAT LAKES REGION. 700MB TEMPERATURES OF 17C WERE OBSERVED AT GREEN BAY WISCONSIN, ALPENA MICHIGAN, AND DETROIT MICHIGAN. 850MB TEMPERATURES OF THE MID TO UPPER 20S STRETCHED FROM THE PANHANDLE OF TEXAS INTO IOWA. AT THE SURFACE A SURFACE BOUNDARY WAS LOCATED ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS AT 12Z. && .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 THROUGH WEDNESDAY) ISSUED AT 351 AM CDT THU JUN 28 2012 THE HOT PATTERN WILL CONTINUE THROUGH THE ENTIRE MEDIUM RANGE FORECAST PERIOD. FOR FRIDAY, THERE IS LOW CONFIDENCE AT THIS TIME ON WHETHER OR NOT A HEAT ADVISORY MIGHT BE NEEDED IN THE EASTERN SECTIONS OF THE FORECAST AREA FOR FRIDAY AFTERNOON. SOME SUPPORT EXISTS IN THE VARIOUS MODELS AND MOS OUTPUT FOR MAXIMUM TEMPERATURES TO OCCUR A FEW DEGREES LOWER FRIDAY AFTERNOON THAN THE LAST COUPLE OF VERY HOT DAYS. LITTLE CHANGE IN THE SURFACE MOISTURE AREAL DISTRIBUTION IS EXPECTED HOWEVER. DEW POINTS WILL STILL REMAIN IN THE UPPER 50S ACROSS CENTRAL KANSAS FOR SEVERAL DAYS, AS NO SYNOPTIC EVENT IS EXPECTED TO ALTER THE SURFACE PATTERN. AS A RESULT, IT IS STILL PLAUSIBLE FOR HEAT INDICES TO REACH 105 DEGREES OR HIGHER ALONG A HAYS TO COLDWATER LINE AND EASTWARD. THE INTENSE RIDGE THAT HAS BEEN CENTERED ACROSS KANSAS PROVIDING VERY STRONG SUBSIDENCE RECENTLY DOES APPEAR TO BECOME FLATTENED BY THE MODELS OVER THE COMING DAYS, BEGINNING AROUND FRIDAY INTO SATURDAY. THE MID LEVEL HIGH NOTED BY THE 594-596 DM ISOHYPSE WILL HAVE SHIFTED TOWARD THE SOUTHERN MISSISSIPPI VALLEY AND EASTWARD BY THAT TIME. THE NAM AND GFS SHOW A VERY WEAK/COMPACT SHORTWAVE MOVING THROUGH THE CENTRAL HIGH PLAINS LATE FRIDAY AS WELL. SOUTHWEST KANSAS SHOULD BE UNDER THE INFLUENCE OF A VERY WARM AND RELATIVELY DRY ATMOSPHERE. ANY THUNDERSTORMS ASSOCIATED WITH LIFT FROM THIS FEATURE WOULD PROBABLY BE VERY HIGH BASED, WITH PRIMARILY A GUSTY WIND THREAT OR POSSIBLE HEAT BURSTS FRIDAY EVENING. THE NAM DOES PRODUCE CONVECTION ASSOCIATED WITH A DRYLINE FEATURE AT THIS TIME FROM AROUND DODGE CITY TOWARD LIBERAL AND ELKHART FRIDAY AFTERNOON, WHICH OTHER MODELS DON`T SEEM TO SUPPORT. IT IS MOST PLAUSIBLE TO HAVE ISOLATED TO WIDELY SCATTERED HIGH BASED THUNDERSTORMS FRIDAY EVENING, AND LIKELY LIMITED TO WEST CENTRAL KANSAS, PROBABLY ROUGHLY NORTHWEST OF A HAYS TO ELKHART LINE. THE REMAINDER OF THE EXTENDED PERIOD APPEARS TO REMAIN VERY WARM TO HOT, BUT BECOMING LESS HOT TOWARD THE WEEKEND AS THE RIDGE REMAINS FAIRLY BROAD OR RELATIVELY FLAT ACROSS THE NORTHERN PLAINS. THE NAM INDICATES A REPEAT OF POTENTIAL HIGH BASED THUNDERSTORMS AGAIN LATE SATURDAY AND/OR SATURDAY EVENING, BUT THIS DOESN`T SEEM AS LIKELY WITHOUT SOME SORT OF UPPER DYNAMIC SUPPORT. 500 MB HEIGHTS WILL DECREASE TO AROUND 588-590 DM THROUGH THE MIDDLE OF THE WEEK WHILE A WEAK LEE TROUGHING PATTERN WITH SOUTHERLY SURFACE FLOW PERSISTING OVER SOUTHWEST KANSAS. HIGH TEMPERATURES ARE LIKELY TO REACH AROUND 100 DEGREES SUNDAY THROUGH WEDNESDAY. THE PATTERN WILL CONTINUE TO SUPPORT MILD OVERNIGHTS IN THE 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1222 PM CDT THU JUN 28 2012 MODEL SOUNDINGS INDICATING WHAT MOISTURE THERE IS PRESENT ACROSS WESTERN AND NORTH CENTRAL KANSAS WILL BE CONFINED ABOVE THE 12000 FT LEVEL LATE TODAY AND EARLY THIS EVENING. AS A RESULT VFR CONDITIONS ARE EXPECTED OVER THE NEXT 18 TO 24 HOURS. SOUTH/SOUTHWEST WINDS AT AROUND 15KTS WILL BACK MORE TO THE SOUTHEAST BY LATE DAY. && .PRELIMINARY POINT TEMPS/POPS... DDC 73 106 74 105 / 0 10 10 10 GCK 72 107 73 103 / 0 10 10 10 EHA 69 105 72 103 / 0 10 10 10 LBL 71 107 73 103 / 0 10 10 10 HYS 75 108 74 104 / 10 10 20 10 P28 75 108 75 105 / 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. && $$ SYNOPSIS...BURGERT SHORT TERM...BURGERT LONG TERM...RUSSELL AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
119 PM EDT THU JUN 28 2012 LATEST UPDATE...AVIATION... .SYNOPSIS... ISSUED AT 343 AM EDT THU JUN 28 2012 HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE WEEKEND AND EARLY NEXT WEEK. THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY. THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD FRONT COMES INTO THE REGION. && .UPDATE... ISSUED AT EDT THU JUN 28 2012 WILL BE EXPANDING THE HEAT ADVISORY TODAY TO INCLUDE THE ENTIRE FORECAST AREA. WE ARE BASING THIS ON RECORD/NEAR RECORD EXPECTED TEMPERATURES AND A LOT OF ONGOING OUTDOOR EVENTS. WILL TRY TO HAVE THE NPW PRODUCT OUT BY 11 AM. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN. ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS SHOULD BEGIN TO DROP. STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON... ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN. THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH TEMPS AROUND 90 AGAIN. A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY. THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W) BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE. WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE VERY HOT AIR SOUTH AND WEST OF HERE. THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20 PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY MORNING) ISSUED AT 119 PM EDT THU JUN 28 2012 VFR CONDITIONS SHOULD PREVAIL THROUGH 18Z FRIDAY. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING. THE RISK IS LOW AND COVERAGE WOULD BE SMALL... SO LEFT VCTS AND CB WITH NO PRECIPITATION. WINDS SHOULD REMAIN BELOW 15 KNOTS... EXCEPT NEAR ANY STORMS WHERE GUSTS UP TO 50 KNOTS ARE POSSIBLE. HAIL IS ALSO POSSIBLE WITH THE THUNDERSTORMS. && .MARINE... ISSUED AT 343 AM EDT THU JUN 28 2012 RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION. && .HYDROLOGY... ISSUED AT 343 AM EDT THU JUN 28 2012 IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ037>040-043>046- 050>052-056>059-064>067-071>074. LM...NONE. && $$ UPDATE...TJT SYNOPSIS...JK SHORT TERM...JK LONG TERM...WDM AVIATION...63 HYDROLOGY...JK MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
108 PM EDT THU JUN 28 2012 .SYNOPSIS... ISSUED AT 343 AM EDT THU JUN 28 2012 HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE WEEKEND AND EARLY NEXT WEEK. THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY. THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD FRONT COMES INTO THE REGION. && .UPDATE... ISSUED AT 105 PM EDT THU JUN 28 2012 BUMPED HIGH TEMPERATURES UP BASED ON LATEST OBSERVATIONS. ALSO KEPT A SLIGHT CHANCES OF THUNDERSTORMS AREAWIDE...WITH A SOMEWHAT GREATER CHANCE NEAR THE I-94 CORRIDOR. THIS COMBINED WITH GREATER THAN EXPECTED HUMIDITY WILL PRODUCE HEAT INDICES WELL INTO THE UPPER 90S AND NEAR 100 IN SPOTS. SURFACE DEWPOINTS HAVE MANAGED TO CLIMB TODAY INTO THE MID 60S F WITH UPPER 60S UPSTREAM AROUND CHICAGO AND LOW 70S IN PARTS OF WISCONSIN. HOWEVER...MDW ACARS SOUNDINGS AT 1530/1630Z SHOW A VERY IMPRESSIVE CAP /30 DEGREES C AT 850 MB/ ALSO IS UPSTREAM. THIS WILL BE VERY DIFFICULT TO OVERCOME...EVEN WITH SURFACE DEWPOINTS IN THE MID/UPPER 60S. SYNOPTIC LIFT AHEAD OF UPPER POT VORT MAX MOVING EAST INTO WI AT THIS TIME HAS RESULTED IN VERY MINOR EROSION OF THE CAP BETWEEN 1530 AND 1630Z. CURRENT THINKING IS THAT SURFACE BASED THUNDERSTORMS ARE UNLIKELY DUE TO THIS CAP. HOWEVER...MID-LEVEL MOISTURE ORIGINATING FROM WEAK CONVECTION OVER WI COULD INTRODUCE ISOLATED SHOWERS WITH AN ATTENDANT THREAT FOR STRONG/SEVERE WINDS DUE TO VERY STEEP LAPSE RATES. UPDATE ISSUED AT EDT THU JUN 28 2012 WILL BE EXPANDING THE HEAT ADVISORY TODAY TO INCLUDE THE ENTIRE FORECAST AREA. WE ARE BASING THIS ON RECORD/NEAR RECORD EXPECTED TEMPERATURES AND A LOT OF ONGOING OUTDOOR EVENTS. WILL TRY TO HAVE THE NPW PRODUCT OUT BY 11 AM. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN. ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS SHOULD BEGIN TO DROP. STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON... ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN. THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH TEMPS AROUND 90 AGAIN. A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM EDT THU JUN 28 2012 WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY. THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W) BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE. WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE VERY HOT AIR SOUTH AND WEST OF HERE. THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20 PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 748 AM EDT THU JUN 28 2012 VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY AFTERNOON. IT IS POSSIBLE FROM LATE MORNING INTO EARLY THIS EVENING AN ISOLATED THUNDERSTORMS COULD IMPACT SOME OF THE TAF SITES. HOWEVER THE RISK IS RATHER LOW SO I PUT VCTS FOR NOW MOSTLY FROM 18Z TO 00Z FOR THE WESTERN TAFS AND 21Z TO 03Z FOR THE EASTERN TAF SITES. WINDS COULD BE GUSTY AND HAIL IS POSSIBLE WITH THE STRONGER THUNDERSTORMS. && .MARINE... ISSUED AT 343 AM EDT THU JUN 28 2012 RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION. && .HYDROLOGY... ISSUED AT 343 AM EDT THU JUN 28 2012 IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ037>040-043>046- 050>052-056>059-064>067-071>074. LM...NONE. && $$ UPDATE...TJT SYNOPSIS...JK SHORT TERM...JK LONG TERM...WDM AVIATION...WDM HYDROLOGY...JK MARINE...JK