Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 292228 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 628 PM EDT TUE JUL 29 2014 .SYNOPSIS... UPPER LEVEL LOW PRESSURE REMAINS OVER THE NORTHEAST FOR THE NEXT SEVERAL DAYS. THIS WILL RESULT IN THE CHANCE OF SHOWERS AND POSSIBLY A THUNDERSTORM EACH AFTERNOON ESPECIALLY IN THE MOUNTAINS. A FRONT WILL APPROACH FROM THE SOUTH ON SATURDAY. A LONG WAVE RIDGE WILL BUILD IN TO START THE WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 625 PM...CU/STRATOCU WILL DISSIPATE WITH THE HEATING. ACTUALLY SEEING SOME BUILDUPS TO THE N OF THE OFFICE ALONG THE SEA BREEZE BOUNDARY...BUT THESE DIMINISH TOO. ALSO...NOTING RETURN OF THIN SMOKE LYR FROM THE VIS SAT IN THE UPPR LVLS THIS EVE...AS TRAJECTORY WOULD ONCE AGAIN BRING IT IN FROM LARGE AREA OF FIRES IN CANADIAN NW TERRITORIES AND NRN ALBERTA. LOWS WILL DROP INTO THE MID TO UPPR 40S N AND 50S MOST EVERYWHERE ELSE. EXPECT SOME PATCHY VALLEY FOG AS WELL. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... FOG WILL BURN OFF IN THE MORNING. AND WILL LEAVE A CLEAR SKY FOR A SHORT TIME BUT EXPECT CU TO DEVELOP WITH THE CHANCE OF MOUNTAIN SHOWERS DURING THE AFTERNOON. UPPER LOW WILL REMAIN TO THE WEST THROUGH THURSDAY WITH A LOBE OF ENERGY MOVING IN EARLY THURSDAY. THIS WILL KICK OFF SHOWERS BEFORE DAWN ON THURSDAY SO POPS INCREASE WEDNESDAY NIGHT. WILL ADD SOME PATCHY VALLEY FOG LATE WEDNESDAY NIGHT ALSO ALTHOUGH FOG MAY NOT BE A BIG FACTOR DEPENDING ON WHEN THE CLOUDS AND SHOWERS MOVE IN. && .LONG TERM /THURSDAY THROUGH TUESDAY/... THURSDAY STARTS WITH A LONG WAVE TOUGH IN PLACE FROM JAMES BAY DOWN TO THE GREAT LAKES. WE WILL SEE SEVERAL SHORT WAVES MOVE THROUGH THIS TROUGH BEFORE IT FINALLY BEGINS TO BREAK DOWN ON SATURDAY. THURSDAY WILL SEE SCATTERED SHOWERS AND THUNDERSTORMS AS A SHORT WAVE MOVES OUT OF THE GREAT LAKES AND THROUGH THE REGION. ALOFT A JET STREAK WILL SERVE TO CONCENTRATE CONVECTION ALONG A LINE EXTENDING FROM ACK TO YQB. FORECAST SOUNDINGS SHOW 800-1000 J/KG OF CAPE WITH A SIGNIFICANT PORTION IN THE HAIL GROWTH ZONE, COMBINED WITH UNIDIRECTIONAL DEEP LAYER WIND SHEAR SEVERE THUNDERSTORMS ARE POSSIBLE, HOWEVER AT THIS POINT CONFIDENCE FOR ALL THE FACTORS COMBINING TOGETHER AT THE RIGHT TIME IS TOO LOW SO HAVE LEFT JUST THUNDERSTORMS FOR THE MOMENT. SCATTERED DIURNALLY DRIVEN SHOWER WILL CONTINUE FOR FRIDAY AND SATURDAY AS A SERIES OF SHORT WAVES CONTINUE TO PROVIDE LIMITED INSTABILITY. FORECAST CONFIDENCE DECREASES SIGNIFICANTLY BY THE END OF THE WEEKEND AS SEVERAL GLOBAL MODELS TRY TO REPLACE THE LONG WAVE TROUGH WITH A HIGH AMPLITUDE RIDGE...WITH VARYING TIMING AND SUCCESS. HAVE LEFT POPS FAIRLY LOW BASED ON A CONSENSUS BLEND, BUT EXPECT TO SEE SOME VARIABILITY WITH THE START OF NEXT WEEK AS IT GETS CLOSER. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... SHORT TERM...EXPECT MOSTLY VFR EXCEPT IFR IN PATCHY VALLEY FOG TONIGHT. LONG TERM... EXPECT MOSTLY VFR CONDITIONS THROUGH THE WEEKEND. && .MARINE... SHORT TERM...WILL EXTEND THE SCA FOR SEAS THROUGH 3AM WEDNESDAY MORNING. OTHERWISE QUIET ON THE WATERS. LONG TERM...QUIET WATERS NO HEADLINES EXPECTED DURING THE EXTENDED. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 AM EDT WEDNESDAY FOR ANZ150-152. && $$ SYNOPSIS... NEAR TERM...CEMPA SHORT TERM... LONG TERM... AVIATION... MARINE...

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