Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 261029 AAB
AFDGYX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GRAY ME
629 AM EDT SAT JUL 26 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE REGION MOVES INTO THE WESTERN ATLANTIC ON
TODAY. AN UPPER LEVEL TROUGH OF LOW PRESSURE MOVES INTO THE AREA
ON SUNDAY AND BRINGS SHOWERS AND ISOLATED THUNDERSTORMS THROUGH
MONDAY OR TUESDAY. HIGH PRESSURE BUILDS IN AGAIN FOR LATER IN THE
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...MOSTLY MINOR CHANGES TO ACCOUNT FOR CURRENT OBSERVATIONAL
TRENDS. OTHERWISE...LARGE AREA OF DENSE SMOKE WILL CONTINUE TO
LIFT NEWD AS SW FLOW TAKES OVER ALOFT. HZ FORECAST IN THE GRIDS
LOOKS ON TRACK FOR WHEN IMPROVING VSBYS CAN BE EXPECTED.

PREVIOUS DISCUSSION...SMOKE FROM FOREST FIRES 2500 MILES AWAY
CONTINUES TO LEAVE MUCH OF THE AREA IN A HZ THIS MORNING. IN FACT
IF YOU GET OUTSIDE BEFORE SUNRISE BEGINS TO MIX THE BOUNDARY
LAYER...YOU MAY BE ABLE TO SMELL THE SMOKE IN THE AIR. UNTIL THAT
TIME WILL KEEP HZ IN THE GRIDS. ATTM PATCHY VALLEY FOG IS ALSO
DEVELOPING. THESE VSBY RESTRICTIONS WILL PERSIST THRU ABOUT 12Z.

INCREASING SW FLOW TODAY WILL AID IN CLEARING OUT THE SMOKE...AS
WELL AS BUMPING TEMPS UP A FEW DEGREES FROM FRI. EXPECT ANOTHER
AFTERNOON OF DIURNAL CU DEVELOPMENT...AND PERHAPS A FEW SHOWERS IN
THE HIGH TERRAIN. LAPSE RATES ARE FAIRLY POOR...SO HAVE NOT ADDED
THUNDER TO THE FORECAST.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AN APPROACHING COLD FNT WILL BEGIN TO SPREAD CLOUDS ACROSS THE
AREA TONIGHT. THAT AND CONTINUED SW FLOW WILL KEEP TEMPS MORE ON
THE MILD SIDE...ESPECIALLY COMPARED TO THE PAST COUPLE OF
OVERNIGHTS.

BY SUN FNT WILL TRY AND CROSS THE AREA. AS IT DOES SO EXPECT
WIDESPREAD SHOWER ACTIVITY. LAPSE RATES DO IMPROVE FOR THE
AFTERNOON...SO THUNDER REMAINS IN THE FORECAST. THE BEST
THERMODYNAMIC PROFILE WILL BE MUCH FARTHER SW...ACROSS THE MID
ATLANTIC...HOWEVER CANNOT RULE OUT AN ISOLD STRONGER
STORM...ESPECIALLY IN SRN ZONES AS SHEAR WILL BE SUPPORTIVE OF
ORGANIZED UPDRAFTS.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
A L/WV TROF PRODUCING A BROAD CYCLONIC FLOW GETS CARVED OUT AND
SHARPENS TO OUR WEST SUN NIGHT AND THRU NEXT WEEK. AN INITIAL
STRONG S/WV ROTATES THRU THIS TROF INTO NEW ENGL SUN NIGHT AND
INTO TUE BEFORE MOVING EWD...THUS NUMEROUS SHWRS/TSTMS ARE
EXPECTED IN THAT TIME FRAME. BY MIDWEEK SOME CLEARING TAKES PLACE BUT
SOME CLDS AND A FEW DIURNAL AFTN SHWRS MAY DEVELOP AS THE THE MEAN
L/WV TROF REMAINS TO OUR W.

USED A BLEND OF MODELS...HPC GUIDANCE FOR QPF...FOR THE OUTLOOK
PERIOD.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...SMOKE FROM FOREST FIRES IN CANADA CONTINUES TO LEAVE
THE AREA IN A HZ. THIS SHOULD GRADUALLY DISPERSE
TODAY...ESPECIALLY AS WINDS PICK UP FROM THE SW. UNTIL THEN HZ AND
PATCHY VALLEY FOG WILL BE POSSIBLE. OTHERWISE EXPECT VFR
CONDITIONS THRU THE DAY SAT. TONIGHT AND ESPECIALLY INTO SUN...AN
APPROACHING COLD FNT WILL BRING A CHANCE FOR RNFL AND MVFR OR
LOWER CONDITIONS.

LONG TERM...UNSETTLED WX WITH SHRA/TSTMS AND MVFR/IFR CONDITIONS
THRU TUE WITH SLOWLY IMPROVING CONDITIONS TUE AND VFR
CONDS BY WED.

&&

.MARINE...
SHORT TERM...SOUTHWEST FLOW STRENGTHENS OVER THE WATERS AS THE
CENTER OF HIGH PRESSURE MOVES OFFSHORE AND A TROUGH OF LOW
PRESSURE APPROACHES FROM THE WEST. CURRENTLY EXPECT WINDS TO STAY
BELOW SCA LEVELS. GUIDANCE CONTINUES TO FORECAST 5 TO 6 FT
SEAS BY SUN...HOWEVER THIS IS TYPICALLY AN OVERESTIMATE IN SW
FLOW. A MARGINAL SCA MAY BE NEEDED SUN REGARDLESS.

LONG TERM...S FLOW AHEAD OF AN APPROACHING COLD FNT WILL LIKELY WARRANT
A SCA OVER THE OUTER WATERS SUNDAY NIGHT THRU MONDAY NIGHT MAINLY
DUE TO BUILDING SEAS BUT POSSIBLY FOR SOME WIND GUSTS AS WELL.
THE FNT STALLS NEAR OR JUST E OF THE WATERS TUESDAY THRU
WEDNESDAY KEEPING WINDS AND SEAS BELOW SCA LEVELS.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...LEGRO






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