Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 181038 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 638 AM EDT FRI APR 18 2014 .SYNOPSIS... HIGH PRESSURE TO OUR EAST WILL PROVIDE A COOL ONSHORE FLOW TODAY. WEAK LOW PRESSURE PASSES NORTH OF THE AREA LATE TONIGHT INTO SATURDAY MORNING...PROVIDE A THREAT OF SHOWERS. MILDER HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT THROUGH MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 635 AM...JUST A FEW MINOR UPDATES OT THE FORECASTS...MAINLY TEMPS AND SKY. SKY WAS ADJUSTED BASED ON PROGRESS OF SCT-BKN STRATUS NWD ACROSS THE GULF OF ME. MOST OF THE MODELS SUGGEST THIS DOES MAKE IT INTO COASTAL AREAS LATER THIS MORNING...BUT MOSTLY AS SCT CLOUDS...AND HAVE ADJ THE GRIDS TO REFLECT 40-50 PERCENT SKY COVER. OTHERWISE NO CHANGES. SFC HIGH PRES SHIFTS OFF THE NE TODAY AND WILL SEE AN EASTERLY FLOW DEVELOP...ALTHOUGH THE SFC HIGH DOES NOSE BACK TO THE WEST A BIT. THIS...COMBINED WITH A VERY DRY COLUMN OF AIR WHICH CONTINUE TO BE ADVECTED FROM THE NE...HAS PREVENTED COASTAL STRATUS FROM DEVELOPING...AND THIS WILL LKLY PERSIST THROUGH A GOOD CHUNK OF TODAY. AS THE HIGH PULLS FURTHER E LATE TODAY AND THIS EVENING...WILL SEE FLOW WEAKEN AND SHIFT MORE SE...WHICH COULD BRING SOME STRATUS IN TO COASTAL AREAS LATE TODAY INTO THIS EVENING. THE ONSHORE FLOW WILL MAKE FOR ANOTHER COOL DAY...WITH HIGHS LOW TO MID 40S ON THE COAST AND WARNING TO AROUND 50 INLAND. OTHERWISE LOOK FOR MAINLY SUNNY SKIES WITH THICKENING CIRRUS THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... WEAK LOW PRES WILL PASS N OF THE CWA LATE TONIGHT INTO SAT MORNING...AND WILL DRAG A COLD FRONT...OF SORTS...ACROSS THE AREA. SHRASN WILL MOVE INTO THE MOUNTAINS OF NH LATE THIS EVENING...AND WORK ACROSS THE INTERIOR ME ZONES AFTER MIDNIGHT. THE 500MB ASSOCIATED WITH THIS SYSTEM MOVES QUICKLY...AND THERE IS A BRIEF SHOT OF DYNAMIC SUPPORT...BUT AIR MASS...ESPECIALLY IN THE MID LVLS REMAINS QUITE DRY...SO QPF ASSOCIATED WITH THE WAVE LATE TONIGHT INTO EARLY SATURDAY ON THE ORDER OF A TENTH OF AN INCH IN THE NRN ZONES. CLOSER TO THE COAST...NOT REALLY EXPECTING ANY PRECIP...ALTHOUGH WONT RULE OUT A SPKL OR FLURRY AROUND 12Z SAT. MINS TONIGHT WILL LKLY OCCUR AROUND MIDNIGHT...WITH TEMPS STEADY OR RISING A BIT DURING THE PRE-DAWN. THE FRONT CLEARS THE CWA BY LATE SAT MORNING...AND SHOULD SEE SOME BREEZY NW WINDS DURING THE AFTERNOON...GUSTS TO 25 MPH OR SO. THIS WILL CLEAR OUT THE DOWNSLOPE AREAS QUICKLY...BUT WILL SLO KEEP THE THREAT OF SOME UPSLOPE SHRASN IN THE MTNS INTO THE AFTERNOON. DECENT LOW TO MID LVL LAPSE RATES DEVELOP RIGHT BEHIND THE FRONT IN THE NW FLOW...AND WOULD NOT BE SURPRISED TO SEE SOME SHOWERS PRODUCE SOME GRAUPEL IN THE MTNS OR FOOTHILLS. MAXES SAT LOOK TO CLIMB INTO THE MID-UPPER 50S OUTSIDE OF THE MTNS...WHERE 50ISH LOOKS LIKE THE LIMIT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... HIGH PRES WILL BE IN CONTROL TO START THE PERIOD. AS THIS HIGH SHIFTS EWD INTO EARLY NEXT WEEK...TEMPS SHOULD GRADUALLY MODERATE TO ABOVE NORMAL. ATTM WEAK SFC FLOW MOVING OFF THE CAROLINAS SHOULD PREVENT DEEPER RETURN OF MOISTURE NWD. THIS SHOULD LIMIT LOW CLOUDS/FOG UNTIL TUE...WHEN APPROACHING FNT FROM THE W INCREASES SLY FLOW. ALONG WITH THE INCREASE IN CLOUDS WILL BE AN INCREASE IN SHRA COVERAGE...FIRST FOR NH THEN ME AS TUE PROGRESSES INTO WED. THEREAFTER MODEL GUIDANCE SUGGEST A COMPLEX INTERACTION BETWEEN GREAT LAKES TROF AND WEAK LOW PRES OFFSHORE. TO SOME EXTENT ALL MODELS CONSOLIDATE THE TWO AREAS OF LOW PRES AND TRY AND CUT IT OFF FROM THE MAIN STEERING WINDS. THE 18/00Z CMC IS THE WEAKEST WITH PHASING...WHILE THE 18/00Z ECMWF IS THE NEXT QUICKEST TO LIFT THE SYSTEM OUT. THE GFS HOWEVER WOULD HAVE THE SYSTEM CUT OFF NEAR THE GULF OF ME...KEEPING UNSETTLED WX LINGERING OVER THE AREA INTO THE LATTER HALF OF THE WEEK. GIVEN NWP IS NOTORIOUSLY POOR WITH HANDLING THESE TYPES OF FEATURES I SEE NO REASON TO DIVERGE FROM A MULTI MODEL CONSENSUS. AT THE VERY LEAST SHRA CHANCES ARE INCREASING TUE INTO WED...WITH THE QUESTION REVOLVING AROUND HOW QUICKLY THEY COME TO AN END. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... SHORT TERM...VFR THROUGH MOST OF TODAY...ALTHOUGH THERE IS A CHC THAT COASTAL TERMINALS SEE MVFR CIGS IN COASTAL STRATUS AFTER 20Z...WITH A BETTER CHC THIS EVENING AND OVERNIGHT. ALL TERMINALS IMPROVE TO VFR SAT MORNING...ALTHOUGH KHIE COULD SEE SOME TEMPO MVFR IN SHRASN ON SAT. LONG TERM...VFR CONDITIONS EXPECTED TO PREVAIL IN THE EXTENDED. A PERIOD OF MVFR TO IFR CONDITIONS WILL BE POSSIBLE TUE INTO WED AS A FRONTAL BOUNDARY/LOW PRES SLOWLY CROSSES THE AREA. && .MARINE... SHORT TERM /THROUGH FRIDAY NIGHT/... PERSISTENT ERLY FLOW WILL BRING SWELL UP TO 5 OR 6 FT TODAY OUTSIDE THE BAYS...AND THIS WILL PERSIST THROUGH TONIGHT. A COLD FRONT CROSSES THE WATERS SAT MORNING...AND FLOW SWITCHES TO NW...WHICH SHOULD KNOCK BACK THE SWELL. LONG TERM..WINDS AND SEAS LOOK TO GENERALLY REMAIN BELOW SCA THRESHOLDS UNTIL EARLY NEXT WEEK. DEVELOPING LOW PRES INVOF THE GULF OF ME MAY AT LEAST BRING A PERIOD OF HIGH SEAS TO THE WATERS AT THAT TIME. && .HYDROLOGY... WE CONTINUE TO SEE RIVER LEVELS SLOWLY RECEDING ATTM. FLOOD WARNINGS REMAIN IN PLACE...THOUGH MAY BE POSSIBLE TO DROP THEM FOR THE ANDROSCOGGIN AND KENNEBEC THIS MORNING. CT RIVER WILL REMAIN ABOVE FLOOD POSSIBLY INTO SAT. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT SATURDAY FOR ANZ150-152-154. && $$ SYNOPSIS... NEAR TERM...CEMPA SHORT TERM... LONG TERM... AVIATION... MARINE... HYDROLOGY...

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