Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 060648 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 248 AM EDT MON JUL 6 2015 .SYNOPSIS... HIGH PRESSURE WILL CREST ACROSS THE REGION TODAY BEFORE SLIDING OFFSHORE. A RETURN FLOW BEHIND THE HIGH WILL TRANSPORT WARMER AND MORE HUMID AIR INTO THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS MIDWEEK. HIGH PRESSURE FOLLOWS FOR THURSDAY INTO THE UPCOMING WEEKEND. && .NEAR TERM /THROUGH TODAY/... AT 06Z...A 1022 MILLIBAR HIGH WAS CENTERED OVER NORTHEAST PENNSYLVANIA. THE SURFACE HIGH WILL SLIDE EAST AND CREST ACROSS THE AREA TODAY BEFORE SLIDING OFFSHORE. GOES INFRARED IMAGERY SHOWED PATCHY LOW AND MID CLOUD ACROSS THE FORECAST AREA...OTHERWISE SKIES WERE MAINLY CLEAR WITH PATCHY FOG AND STRATUS FORMING ACROSS SOME INTERIOR VALLEY LOCATIONS. FOR TODAY...ANY EARLY MORNING FOG WILL QUICKLY BURN OFF LEAVING MOSTLY SUNNY SKIES UNDER THE SURFACE HIGH. WE`LL WARM INTO THE 80S UNDER THE STRONG JULY SUNSHINE...WITH CONDITIONS A BIT COOLER ALONG THE COAST WHERE THE LIGHT SYNOPTIC FLOW WILL TURN ONSHORE BY AFTERNOON. && .SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/... A CLEAR START TONIGHT...THEN WARM AIR ADVECTION MID AND HIGH CLOUDS WILL SPREAD NORTHWARD INTO THE FORECAST AREA AFTER MIDNIGHT. LOWS TONIGHT SHOULD BE MAINLY IN THE 60S. MOISTURE CONTINUES TO STREAM NORTHWARD INTO THE AREA ON TUESDAY WITH A MIX OF CLOUDS AND SUNSHINE AND TEMPERATURES WARMING INTO THE 80S...WITH SOME 70S NEAR THE COAST IN ONSHORE FLOW. EXPECT SHOWERS AND A FEW THUNDERSTORMS TO DEVELOP BY AFTERNOON IN RESPONSE TO DAYTIME HEATING AND WITH APPROACH OF UPPER TROUGH. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... THE LONG TERM APPEARS MOST ACTIVE EARLY IN THE PERIOD...AS COLD FRONT SLOWLY WORKS ITS WAY ACROSS THE NORTHEAST. FAIRLY STOUT S/WV RIDGE IS PLACE AHEAD OF THE COLD FRONT SEEMINGLY CONTINUES TO SLOW FROPA IN MODEL FORECASTS. AHEAD OF THE FRONT WILL EXIST A WARM AND HUMID AIR MASS. HOWEVER...LAPSE RATES ALOFT ARE FORECAST TO BE RATHER POOR...AS ANY ELEVATED MIXED LAYER AIR REMAINS BOTTLED UP TO OUR SW WITH PERSISTENT ERN TROFING. EVEN SO...DEWPOINTS CLIMBING WELL INTO THE 60S SHOULD AT LEAST PROVIDE FOR MODEST INSTABILITY. THE OTHER ISSUE IS FORCING ALOFT...AS S/WV TROF WILL BE SHEARING OUT OFF TO THE NE. THIS LEAVES THE STRONGEST WIND FIELD ACROSS SRN CANADA...AND SHEAR LACKING ACROSS NH AND WRN ME. LATEST SPC SREF SUGGEST 30 KTS OF 0-6 KM SHEAR IS ABOUT A COIN FLIP ACROSS THE NRN ZONES...WHICH WOULD BE JUST ABOUT ENOUGH FOR POSSIBLE STORM ORGANIZATION. AS SUCH...WOULD NOT BE SURPRISED TO SEE SPC EXTENDED A MARGINAL SEVERE TSTM RISK INTO PARTS OF THE FORECAST AREA...AS A DOWNSTREAM CONTINUATION OF SWODY2 MARGINAL RISK ACROSS PARTS OF THE GREAT LAKES. A VERY WARM AND MOIST COLUMN WILL LIMIT ANY THREAT TO WATER LOADED WIND GUSTS AND HEAVY RNFL. AFTER THE FRONT CLEARS THE COAST...HIGH PRES WILL GENERALLY BE IN CONTROL. MODEL FORECASTS ARE IN AGREEMENT THAT FLOW BECOMES SOMEWHAT MORE ZONAL ACROSS THE NORTHEAST FOR THE SECOND HALF OF THE WEEK...KEEPING THE REAL HOT AND HUMID AIR S ACROSS THE MID ATLANTIC. LATE IN THE PERIOD WRN RIDGING TRIES TO RELOAD...WHICH IN TURN WILL HELP HEIGHTS TO FALL ACROSS THE ERN CONUS. S/WV DROPPING INTO THE TROF WILL TRY AND DRAW MOIST AIR MASS BACK NWD...GIVING THE NEXT BEST CHANCE FOR PRECIP EARLY NEXT WEEK. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... SHORT TERM /THROUGH 00Z WED/...MAINLY VFR THRU TONIGHT...EXCEPT FOR VLY FOG VCNTY OF KHIE/KLEB THIS MORNING...AND PSBLY TUE MORNING AS WELL. SCT MVFR TUE AFTERNOON IN SHRA AND TSRA. LONG TERM...VFR EXPECTED TO PREVAIL THRU THE EXTENDED. BEST CHANCE FOR CIG/VSBY RESTRICTIONS APPEARS TO BE WED...AS COLD FRONT CROSSES THE AREA. MOST LIKELY IS SCATTERED MVFR AND ISOLD IFR IN SHRA/TSRA AS FRONT CROSSES THE FORECAST AREA. VFR RETURNS THU THRU THE WEEKEND. && .MARINE... SHORT TERM /THROUGH TUESDAY/...WINDS AND SEAS WILL REMAIN WELL BLO SCA LVLS THROUGH TUESDAY AS HIGH PRESSURE TRAVERSES THE WATERS. LONG TERM...WINDS ARE EXPECTED TO REMAIN BELOW SCA THRESHOLDS THRU THE EXTENDED. EXTENDED PERIOD OF SWLY FLOW OVER THE OUTER WATERS AHEAD OF APPROACHING MIDWEEK COLD FRONT MAY BRING A PERIOD OF 5 FT SEAS WED BEFORE SUBSIDING. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ NEAR TERM...SCHWIBS SHORT TERM...SCHWIBS LONG TERM...LEGRO AVIATION...SCHWIBS/LEGRO MARINE...SCHWIBS/LEGRO

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