FXUS61 KGYX 251429
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
929 AM EST WED NOV 25 2009
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL SLOWLY EXIT INTO THE CANADIAN
MARITIMES FROM THE GULF OF MAINE TODAY AND TONIGHT. LOW PRESSURE
WILL FORM OFF THE NORTH CAROLINA COASTLINE ON THANKSGIVING. IT WILL
RACE NORTH THURSDAY NIGHT...BEFORE EXITING THROUGH MAINE FRIDAY. A
STRONG WEST TO NORTHWEST FLOW WILL FOLLOW FOR THE WEEKEND. LOW
PRESSURE WILL SLOWLY MOVE NORTH FROM THE GULF OF MEXICO TOWARDS
THE GREAT LAKES EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...WILL TWEAK THE MAX TEMPS FOR TODAY DOWN A DEGREE OR TWO
AND WILL CHANGE WORDING A BIT TO ADD PATCHY LIGHT DRIZZLE AND DROP
THE SHOWERS. WILL ALSO KEEP PATCHY FOG IN THROUGH MOST OF THE DAY
ESPECIALLY IN COASTAL LOCATIONS. SHORT WAVE WILL MOVE TRHOUGH
TONIGHT WHICH WILL INCREASE THE CHC FOR SHOWERS.
PREV DISC...LIGHT NORTHERLY FLOW AT THE SURFACE WILL CONTINUE TO KEEP
PLENTY OF MOISTURE IN AND AROUND THE COASTLINE TODAY. HIGHER
UP...AROUND 5 KFT...WINDS WILL REMAIN LIGHT WITH AN EASTERLY
COMPONENT. MEANWHILE...PLENTY OF LOW LEVEL MOISTURE...FOG AND SOME
PATCHY DRIZZLE WILL GRADUALLY LIFT OVER INTERIOR LOCATIONS.
WITH NOTHING TO SCOUR OUT THE MOISTURE...WILL CONTINUE TO PLAY UP
CLOUDS TODAY. USED A BLEND OF MAV/MET MOS FOR HIGH
TEMPERATURES...WITH THE MET GUIDANCE APPEARING TO BE TOO WARM
ALONG THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
PATCHY DRIZZLE AND FOG TO FORM ONCE AGAIN. FLOW NEAR THE SURFACE
WILL CONTINUE TO BE VERY WEAK. A QUICK SHOT OF WEAK UPPER LEVEL
SUPPORT AND FORCING WILL RACE OVER THE REGION THIS
EVENING...POSSIBLY TRIGGERING A SHOWER.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
A WEAK RIDGE OF HIGH PRES WILL REMAIN OVER THE AREA THURS BUT WILL
GIVE WAY QUICKLY BY THURS EVENING TO A COASTAL LOW THAT DEVELOPS
OFF THE MID ATLANTIC COAST AND THEN MOVES INTO THE GULF OF MAINE
FRIDAY AND THEN INTO THE MARITIMES OVER THE WEEKEND. OCEAN STRATUS
FOLLOWED BY RAIN AND DRZL WILL QUICKLY SPREAD FROM S-N THU NGT AND
CONTINUE INTO FRIDAY BEFORE THE DRY SLOT MOVES THRU AS THE SFC LOW
GETS CAPTURED BY THE UPPER LOW. THE BIG QUESTION WHICH CANNOT BE
ANSWERED UNTIL FUTURE MODEL RUNS WILL BE THE EXACT TRACK AND
WHETHER THE LOW WILL DEEPEN MUCH QUICKER THAN MODELS ARE CURRENTLY
INDICATING. THIS WILL POSE A PROBLEM FOR FORECAST AMTS OF QPF LATE
THU NGT AND FRI. AS FAR AS PTYPE THE SYSTEM SHOULD BE ALL RAIN
SINCE IT WILL HAVE SUFFICIENT WARM AIR WRAPPING INTO IT WITH CAA
NOT OCCURRING UNTIL AFTER ITS PASSAGE INTO THE MARITIMES. THE
NEGATIVE TILT OF THE TROF IN THE MID/UPR LEVELS IS IMPRESSIVE SO
THIS STILL MUST BE WATCHED VERY CLOSELY FOR XPLOSIVE DEEPENING
WHICH MAY POSE MORE OF A PROBLEM FOR THE COASTAL WATERS FORECAST.
OVERALL USE A BLEND OF THE MET/MAV GUIDANCE FOR TEMPS. LEANED MORE
IN LINE WITH MAV POPS OF GFS SINCE NAM APPEARED TOO SLOW IN
BRINGING QPF FURTHER N.
IN THE STORMS WAKE OVER THE WEEKEND A STRONG NWLY WIND FLOW WILL
DEVELOP WITH SCT SNW SHWRS IN THE MTNS WHILE DOWNSLOPE AREAS SEE
ONLY PARTLY CLOUDY SKIES.
ANOTHER LARGE SYSTEM WILL APPROACH THE LOWER OHIO VALLEY EARLY
NEXT WEEK BUT MODELS NOT SHOWING ANY CONTINUITY SO WILL BROAD
BRUSH EARLY NEXT WEEK DUE TO LACK OF CONFIDENCE.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...LIFR AND IFR CONDITIONS IN SEVERAL AREAS WILL BE SLOW
TO IMPROVE TODAY. CONDITIONS DETEORATE ONCE AGAIN THIS EVENING.
LONG TERM...VFR CONDITIONS THURSDAY WILL BECOME IFR THU NGT AND
FRI IN DVPG RN AND AREAS OF DRZL AND FOG AS A COASTAL LOW DVLPS
OFF THE MID ATLANTIC COAST AND THEN MOVES INTO THE GULF OF MAINE
FRI. CONDS IMPROVING TO MVFR TO VFR ON FRIDAY WITH STILL SOME
LINGERING INSTABILITY SHWRS AS AN UPPER LOW PASSES OVERHEAD. VFR
CONDS ARE EXPECTED FOR SAT AND SUN AS A DRIER NWLY FLOW DVLPS.
&&
.MARINE...
SHORT TERM...HAVE EXPANDED SCAS INTO THE BAYS FOR TODAY AS WAVES
CONTINUE TO RUN HIGH. WITH OFFSHORE SYSTEM SLOW TO WEAKEN AND MOVE
OUT...EXPECT THE WAVES TO HOLD ON THROUGHOUT THE DAY. FOLLOWED THE
GFS BASED SWAN MODEL CLOSELY THIS PACKAGE.
LONG TERM...A COASTAL LOW WILL DVLP OFF THE MID ATLANTIC COAST THU
NGT AND THEN MOVE INTO THE GULF OF MAINE FRIDAY. DEPENDING HOW
QUICKLY THE SFC LOW DEEPENS WILL DETERMINE THE STRENGTH OF THE
GRADIENT WINDS SO FOR NOW WILL SUFFICE TO SAY GALE FORCE WINDS ARE
PSBL LATE THU NGT INTO FRI EVEN THO FCST WINDS AT THIS TIME ARE
BELOW THOSE THRESHOLDS. IN THE STORMS WAKE OVER THE WEEKEND A RATHER
STG NWLY WIND GRADIENT WILL LIKELY BE AT LEAST INTO THE SCA
RANGE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ151-
153.
SMALL CRAFT ADVISORY UNTIL 6 AM EST THURSDAY FOR ANZ150-152-
154.
&&
$$
UPDATE...TFH
