Area Forecast Discussion
Issued by NWS Portland, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KGYX 210722 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 322 AM EDT MON JUL 21 2014 .SYNOPSIS...
-- Changed Discussion --
WEAK LOW MOVES OFF TO OUR SOUTHEAST THIS MORNING AND HIGH PRESSURE BUILDS TO OUR SOUTH BEHIND IT. THIS WILL MAKE FOR GENERALLY FAIR CONDITIONS TODAY AND TUESDAY....ALTHOUGH TEMPERATURES WILL BE SIGNIFICANT WARMER ON TUESDAY. WEDNESDAY REMAINS VERY WARM AND HUMID...BUT A COLD FRONT APPROACHES LATE IN THE DAY AND BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS. THE FRONT MOVES ACROSS THE REGION WEDNESDAY NIGHT AND EXITS OFFSHORE THURSDAY MORNING. HIGH PRESSURE BUILDS IN FROM THE WEST FRIDAY AND SATURDAY.
-- End Changed Discussion --
&& .NEAR TERM /TODAY/...
-- Changed Discussion --
THE WEAK OCEAN LOW WILL SLIDE WELL TO OUR S AND E THIS MORNING... AND SURFACE HIGH...CENTERED TO OUR S...BEGINS TO BUILD. THIS SHOULD ALLOW FOR A AN ONSHORE FLOW TO DEVELOP...AS WEAK ONSHORE PGF DEVELOPS POLEWARD OF THE RIDGE. MAXES SHOULD BE CLOSE TO NORMAL INLAND AREAS...AROUND 80...ALTHOUGH GIVEN THE ONSHORE FLOW COASTAL AREAS WILL BE STUCK IN THE LOW TO MID 70S. NAM CONTINUES TO PRODUCE SOME POPS OVER THE MOUNTAINS...WHILE ALL OTHER MODELS KEEP THINGS DRY. NOT SURE IF ITS PICKING UP ON WEAK UPSLOPE EASTERLY FLOW...OR THE LINGERING WEAK TROUGH AT 500 MB...OR A COMBINATION OF BOTH...BUT WITH DEW POINTS ON THE RISE AND SOME INSTABILITY IN PLACE...FEEL THAT POPS OF 15-20 FOR A FEW HOURS DURING PEAK HEATING ARE WARRANTED.
-- End Changed Discussion --
&& .SHORT TERM /TONIGHT AND TUESDAY/...
-- Changed Discussion --
WE START TO TO SEE THE W-SW FLOW BEGIN TO PICK UP A BIT IN THE BOUNDARY LAYER TONIGHT AS THE HIGH BEGINS TO BUILD MORE TO OUR SE THAN S...HELPING TO PUSH DEW POINTS UP A BIT...AND GENERALLY LIMITING THE BEST RADIATIONAL COOLING...SO MINS NOT AS COLD AS THIS MORNING...BUT STILL IN THE 50S TO AROUND 60. SHOULD SEE ANOTHER ROUND OF VALLEY FOG...AS WE SEE INCREASING DEW POINTS... BUT ALSO MORE FLOW IN THE BOUNDARY LAYER. STILL QUESTIONS ARISE AS TO COASTAL STRATUS/FOG...BUT MODELS SUGGESTING IF IT DOES OCCUR LOOKS TO BE AFTER SUNSET...WITH BETTER CHANCE ALONG THE MID- COAST. HAVE THROWN SOME PARTLY CLOUDY CONDITIONS IN ON THE COAST FOR NOW. ON TUESDAY...WILL SE THAT VERY ARM MID LEVEL AIR ADVECTING IN FROM THE WSW...GENERALLY REACHING 15-17C...WHICH WILL TRANSLATE INTO THE HIGHS INTO THE MID-UPPER 80S ACROSS INLAND AREAS. DEW POINTS WILL CREEP UP INTO THE MID TO UPPER 60S BY AFTERNOON...SO IT WILL BE NOTICEABLY MORE HUMID AS WELL. SYNOPTIC FLOW SHIFTS TO SW BY TUESDAY AFTERNOON...AND THIS WILL TURN ONSHORE ALONG THE E FACING COASTS...KEEPING THEM A FEW DEGREES COOLER...WHILE THE MID- COAST WILL MAX OUT IN THE MID 70S TO AROUND 80. MODELS SUGGESTING SOME PRECIPITATION DEVELOPS VICINITY OF NH/MA BORDER TUESDAY AFTERNOON... MAYBE ON SEA BREEZE BOUNDARY.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --
WITH MORE MOISTURE AROUND... TUESDAY NIGHT WILL BE A MORE HUMID NIGHT WITH LOWS IN THE 60S. ON WEDNESDAY... THE UPPER RIDGE AXIS MOVES EAST OF THE AREA AND IS REPLACED BY A TROUGH MOVING IN FROM THE NORTHWEST. SURFACE COLD FRONT WILL ALSO PUSH SOUTHEAST ACROSS THE AREA ON WEDNESDAY... LIKELY REACHING THE COAST BY WEDNESDAY EVENING. MODELS ARE IN BETTER AGREEMENT ON THE TIMING OF THIS FRONT NOW. TEMPERATURES WEDNESDAY WILL BE WARMER THAN WE HAVE SEEN IN A WHILE. 850 MB TEMPERATURES WARM TO AROUND +18C WHICH IF MIXED DRY ADIABATICALLY TO THE SURFACE WOULD TRANSLATE TO AROUND 90F FOR A MAXIMUM TEMPERATURE. MOST LIKELY AREAS TO SEE 90 WILL BE IN SOUTHEAST NEW HAMPSHIRE AND SOUTHWEST MAINE. SOUTHWEST FLOW AT THE SURFACE WILL NOT BE ENOUGH TO KEEP THE SEA BREEZE AWAY FROM THE COAST... SO COASTAL AREAS (ESPECIALLY FROM PORTLAND EASTWARD) WILL BE SIGNIFICANTLY COOLER. OF COURSE WITH ALL THE HEAT AND HUMIDITY AROUND ON WEDNESDAY... THERE WILL ALSO BE PLENTY OF INSTABILITY. THAT WARM AIR ALOFT WILL ACTUALLY SERVE AS A CAP TO PREVENT THUNDERSTORMS FROM DEVELOPING INITIALLY. BUT THIS CAP WILL BE ERODED FROM THE BOTTOM AND THE TOP AS THE DAY GOES ON... WITH WARMING SURFACE TEMPERATURES AND COOLING TEMPERATURES ALOFT WITH THE APPROACHING TROUGH COMBINE TO OVERCOME THE CAP AND ALLOW ACCESS TO THE INSTABILITY. THROW IN SOME SURFACE CONVERGENCE ALONG THE FRONT AND LIFT AHEAD OF THE UPPER TROUGH AND THERE SHOULD BE A FAIRLY WIDESPREAD COVERAGE OF THUNDERSTORMS BY WEDNESDAY AFTERNOON. WILL LIKELY SEE STORMS FORM INITIALLY OVER THE MOUNTAINS AND IN SOUTHERN CANADA BEFORE MOVING SOUTHEAST DURING THE AFTERNOON. WIND PROFILES WILL AT LEAST BE SUPPORTIVE OF MULTICELL THUNDERSTORMS AND THE ASSOCIATED CONVECTIVE WIND THREAT. BUT THERE MAY ALSO BE ENOUGH SHEAR FOR SOME SUPERCELL STRUCTURE... DEPENDING ON THE TIMING OF THE SURFACE AND UPPER LEVEL FEATURES. HAVE INCLUDED GUSTY WINDS AND SMALL HAIL IN THE FORECAST FOR WEDNESDAY AND HAVE MENTIONED POTENTIAL SEVERE WEATHER IN THE HAZARDOUS WEATHER OUTLOOK. THE FRONT WILL PUSH OFFSHORE ON WEDNESDAY NIGHT... DECREASING RAIN CHANCES AS IT DOES SO. BY THURSDAY A DRIER AND COOLER AIR MASS WILL BE MOVING IN WITH HIGH TEMPERATURES ABOUT 10 DEGREES COOLER THAN WEDNESDAY. UPPER TROUGH REMAINS OVER QUEBEC AND NEW ENGLAND FRIDAY AND SATURDAY... SO CANNOT COMPLETELY RULE OUT A STRAY SHOWER. BUT THE GENERAL TREND WILL BE DRY AND COOLER WITH HIGHS IN THE 70S TO NEAR 80 AND LOWS IN THE 50S TO NEAR 60.
-- End Changed Discussion --
&& .AVIATION /07Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
SHORT TERM...SEEING VALLEY FOG DEVELOPING AT NON-TERMINAL SITES... BUT NOTHING YET AT THE TERMINALS. EXPECT KHIE/KLEB TO SEE SOME FOG/STRATUS BY SUNRISE...WITH SOME FOG POSSIBLE FOR AN HOUR OR TWO AT KCON AND MAYBE KAUG. VFR EXPECTED THROUGH THE DAY TODAY. ANOTHER ROUND OF VALLEY FOG TONIGHT...AND THERE IS THE POSSIBILITY OF COASTAL FOG STRATUS DEVELOPING LATER THIS EVENING. ALL TERMINALS RETURN TO VFR BY TUESDAY MORNING. LONG TERM...EXPECT SHOWERS AND THUNDERSTORMS TO MOVE FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA WEDNESDAY AFTERNOON AND EVENING. COULD SEE SOME FOG LATE WEDNESDAY NIGHT AFTER THE RAIN MOVES THROUGH. VFR CONDITIONS EXPECTED THE REST OF THE WEEK WITH THE USUAL CAVEATS ABOUT NOCTURNAL FOG AT LEB AND HIE.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
SHORT TERM...LIGHT WINDS AND SEAS EXPECTED THROUGH TONIGHT....WITH SEA BREEZE DEVELOPING THIS AFTERNOON. WILL START TO SEE WSW WINDS INCREASE TUESDAY AFTERNOON...BUT STAYING BELOW SCA LEVELS. LONG TERM...SOUTHWEST FLOW AHEAD OF THE FRONT ON WEDNESDAY WILL PEAK AT 20 OR 25 KT... WITH WAVE HEIGHTS RISING TO 4 TO 5 FEET. COLD FRONT SHOULD BRING THE STRONGER WINDS TO AN END WEDNESDAY NIGHT AND WAVE HEIGHTS SUBSIDE THROUGH THE REST OF THE WEEK.
-- End Changed Discussion --
&& .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ SYNOPSIS...CEMPA NEAR TERM...CEMPA SHORT TERM...CEMPA LONG TERM...KIMBLE AVIATION...CEMPA/KIMBLE MARINE...CEMPA/KIMBLE

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.