Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 301908 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 308 PM EDT TUE JUN 30 2015 .SYNOPSIS... AN AREA LOW PRESSURE WILL APPROACH FROM THE WEST TONIGHT AND WILL PASS JUST NORTH OF THE REGION ON WEDNESDAY. THIS SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS TO THE REGION ON WEDNESDAY BEFORE HIGH PRESSURE MOVES IN ON THURSDAY. HIGH PRESSURE THEN REMAINS IN PLACE INTO THE HOLIDAY WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AREA OF PRECIPITATION MOVING THROUGH VERMONT AND NEW HAMPSHIRE THIS AFTERNOON. MOST OF THE MODELS ARE NOT HANDLING THIS WELL. HOWEVER...THE SREF SEEMS TO BE PICKING IT UP DECENTLY. HAVE USED IT FOR THE IMMEDIATE SHORT TERM POPS. PRECIPITATION IS TRENDING A LITTLE FURTHER EAST THAN THE MODEL THOUGH. EVENING SHIFT MAY NEED TO SHIFT POPS INTO MAINE MORE...BUT IT IS POSSIBLE THAT IT WILL DIE OFF AS WE LOSE DIURNAL HEATING. SIMILAR TO LAST NIGHT...EXPECT PATCHY FOG TO DEVELOP OVER IN FAVORED VALLEY LOCATIONS AND ALONG THE COAST. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... FAIRLY COMPLEX WEATHER PATTERN FOR TOMORROW AND TOMORROW NIGHT. LOW PRESSURE SYSTEM MOVING OUT OF THE GREAT LAKES WILL LIFT A WARM FRONT ACROSS THE REGION LATE TONIGHT AND TOMORROW. IT IS LOOKING LIKE THE MAJORITY OF THE FORECAST AREA IS GOING TO SEE EXTENSIVE CLOUD COVER AND RAIN FOR A GOOD PART OF THE DAY. HOWEVER...SEVERAL OF THE MODELS ARE SHOWING SOME LATE INSTABILITY MOVING OVER PORTIONS OF NEW HAMPSHIRE. FORECAST SOUNDINGS FROM THE NAM12 ARE INDICATING THE POSSIBILITY OF UP TO ABOUT 1800J/KG OF CAPE FOR STORMS TO WORK WITH BY 5 OR 6PM TOMORROW. THERE IS ALSO SOME DECENT SHEAR AS WELL. THE KEY WILL BE WHETHER OR NOT THE ATMOSPHERE CAN RECOVER ENOUGH FROM THE PRECIPITATION EARLIER IN THE DAY. THIS SEEMS TO BE A RELATIVELY COMMON OCCURRENCE IN NEW ENGLAND. WILL BRING IN THUNDERSTORM WITH GUSTY WINDS AND HAIL FOR NOW AND THEN LET THE MIDNIGHT SHIFT EVALUATE AGAIN TO SEE IF SEVERE WORDING IS NEEDED. && .LONG TERM /THURSDAY THROUGH TUESDAY/... HIGH PRESSURE WITH JUST A FEW WEAK DISTURBANCES SHOULD DOMINATE THE WEATHER MUCH OF THIS FORECAST PERIOD. ON THURSDAY A NW FLOW AHEAD OF HIGH PRESSURE BUILDING IN WILL RESULT IN A DRYING AIRMASS. THE EXCEPTION MIGHT BE SOME UP SLOPE CLOUDS AND AN ISLATED SHOWER OR TWO OVER THE MOUNTAINS. HIGH PRESSURE TO CREST OVER THE REGION ON FRIDAY INTO EARLY SATURDAY. ONE POSSIBLE COMPLICATION TO THE WEEKEND FORECAST IS THE POSSIBILITY OF A BACKDOOR COLDFRONT DROPPING DOWN LATE SATURDAY AND SUNDAY. LATEST GFS SHOWS THIS POSSIBILITY. AT THIS TIME IT WOULD SEEM THAT IT HAS VERY LITTLE MOISTURE TO WORK WITH SO THIS MAY BE MORE OF A SLIGHT COOL DOWN WITH A WIND SHIFT AND SOME BROKEN CLOUDS. GFS MODEL WINDS SHIFT FROM SW TO NW SATURDAY NIGHT AND SUNDAY. HIGH PRESSURE WILL BUILD BACK OVER THE REGION ON MONDAY. GFS IS SLOWER IN MOVING HIGH OUT ON TUESDAY THEN ECMWF...WHICH BRINGS IN A SHOWER THREAT ON TUESDAY. WILL SPLIT THE DIFFERENCE IN POPS FOR NOW AS IT IS STILL 7 DAYS OUT. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SHORT TERM... VFR CONDITIONS WILL DROP TO MVFR/IFR BY MORNING IN A MIX OF RAIN AND FOG. TAF SITES MIGHT RECOVER A BIT BRIEFLY EARLY TOMORROW BUT WILL LIKELY STAY MVFR/IFR FOR MOST OF THE DAY. LONG TERM... THURSDAY THROUGH SUNDAY...VFR FOR MOST OF THE PERIOD AS HIGH PRESSURE WILL CONTROL THE WEATHER THURSDAY INTO SATURDAY. A PERIOD OF MVFR IS POSSIBLE LATE SATURDAY INTO SUNDAY AS A BACKDOOR COLD FRONT APPROACHES. && .MARINE... SHORT TERM... NO FLAGS EXPECTED...ALTHOUGH WINDS AND SEAS COULD COME CLOSE TO SCA CRITERIA LATE TOMORROW. LONG TERM... THURSDAY THROUGH SUNDAY...WIND AND WAVES TO REMAIN BELOW SCA LEVELS. W NW WINDS THURSDAY TO TURN SW FRIDAY INTO SATURDAY. WIND WILL TURN NW ON SUNDAY AND MONDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ SYNOPSIS...LULOFS NEAR TERM...POHL SHORT TERM...POHL LONG TERM...LULOFS AVIATION...LULOFS/POHL MARINE...LULOFS/POHL

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