FXUS61 KGYX 020744
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
244 AM EST WED DEC 2 2009
.SYNOPSIS...HIGH PRESSURE WILL HOLD OVER THE AREA TODAY AS LOW
PRESSURE APPROACHES FROM THE SOUTHWEST. LOW PRESSURE WILL MOVE
NORTHEAST OUT OF THE OHIO VALLEY TONIGHT REACHING CENTRAL NEW YORK
BY THURSDAY MORNING THEN MOVING INTO NORTHERN MAINE BY THURSDAY
EVENING. HIGH PRESSURE WILL BUILD SOUTH OF THE REGION THURSDAY
NIGHT AS LOW PRESSURE CONTINUES TO LIFT NORTH. HIGH PRESSURE WILL
BUILD OVER THE AREA FRIDAY AND WILL HOLD THROUGH SATURDAY AS LOW
PRESSURE PASSES TO THE SOUTHEAST. ANOTHER AREA OF HIGH PRESSURE
WILL BUILD IN FROM THE WEST SUNDAY THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH PRESSURE WILL HOLD OVER THE REGION TODAY AS LOW PRESSURE
APPROACHES FROM THE SOUTHWEST. RETURN FLOW WILL BRING A SURGE OF
WARMER AIR INTO THE REGION WITH HIGH TEMPERATURES TOPPING OUT 5 TO
10 DEGREES ABOVE TUESDAY'S HIGHS. LINGERING LOW LEVEL MOISTURE IN
NORTHERN AND WESTERN ZONES WILL GRADUALLY DIMINISH THROUGH THE
MORNING HOURS WITH THE REMAINDER OF THE REGION SEEING A MOSTLY
SUNNY MORNING. EXPECT SOME HIGH CLOUDINESS TO SPILL INTO SOUTHERN
AND WESTERN ZONES THIS AFTERNOON. LOOKING FOR HIGH TEMPS TO TOP
OUT WELL ABOVE NORMAL...CLIMBING TO NEAR 50 IN THE WARMEST
LOCATIONS IN THE SOUTH.
&&
.SHORT TERM /TONIGHT/...
CLOUDS THICKEN UP OVER THE REGION TONIGHT AS A STRONG AREA OF
OVER-RUNNING SHIFTS INTO THE REGION FROM THE SOUTHWEST AHEAD OF
LOW PRESSURE MOVING OUT OF THE OHIO VALLEY. EXPECT RAIN TO BEGIN
AROUND MIDNIGHT IN SOUTHWEST ZONES...QUICKLY OVER-SPREADING THE
REMAINDER OF THE FORECAST AREA THROUGH THE EARLY MORNING HOURS.
MODELS GENERALLY SHOWING RAINFALL AMOUNTS THROUGH THURSDAY MORNING
OF A QUARTER TO 1 INCH ACROSS THE REGION WITH HIGHEST AMOUNTS IN
SOUTHERN NEW HAMPSHIRE. TEMPERATURES SHOULD BOTTOM OUT EARLY IN
THE EVENING AND THEN BEGIN RISING OVERNIGHT SO HAVE GONE WITH NON-
DIURNAL TEMP PROFILE IN THE GRIDS. EXPECT WARMER SPOTS IN SOUTHERN
ZONES TO RISE INTO THE MID 40S TO NEAR 50 BY THURSDAY MORNING.
EXPECT WINDS AND PRECIPITATION TO PICK UP AFTER MIDNIGHT AS
STRONG LOW LEVEL JET SHIFTS INTO THE REGION.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
STRONG SHORT WAVE MOVES QUICKLY NE THRU THE UPR LVL SW FLOW ON
THURSDAY. THIS CAUSES A SFC LOW TO MOVE NE FROM NRN NY STATE TO
NRN ME WITH A TRAILING CD FNT RAPIDLY WRAPPING AROUND THE LEADING
WRM FNT CAUSING IT TO OCCLUDE AS IT MOVES THRU THE FCST AREA. DRY
AIR WRAPS AROUND THE SFC LOW AND PUSHES IN BEHIND THE OCCLUSION
WHICH EXITS THE FCST AREA QUICKLY BY 18Z THURSDAY. THIS GIVES US A
QUICK SHOT OF HEAVY RAIN AND WIND...WHICH MAY BECOME GUSTY AHEAD OF
THE SYSTEM IF WE CAN MIX THE STRONG WINDS ALOFT DOWN /NOT LIKELY IF
WE STAY IN THE COLD AIR AS THE FNT OCCLUDES...BUT PSBL BEHIND THE
FNT AS BETTER MIXING LIKELY BEHIND THE FNT THOUGH WINDS ALOFT DROP
OFF SOMEWHAT BY THEN/.
THE FLOW ALOFT STAYS FROM THE SW BEHIND THE SFC SYSTEM...THUS COLD
AIR TO OUR W DOES NOT INVADE THE FCST AREA VERY QUICKLY...THOUGH A
GENERALLY COOLING TREND CAN BE EXPECTED. WINDS WILL BE FAIRLY GUSTY
BUT NOT EXTREMELY SO SINCE WINDS WON'T LINE UP FROM SFC TO H5. DRY
WX DOES PREVAIL LATE THURSDAY THRU FRIDAY NGT AS WEAK AREA OF HIGH
PRES BUILDS IN.
A SFC LOW MOVES NE OFF THE E COAST SATURDAY AND SATURDAY NGT AS A
SHORT WAVE SYSTEM ALOFT MOVES OFF THE COAST THEN HEADS E NE OUT TO
SEA. LATEST RUN OF THE GFS SHOWS IT STAYING FAR ENOUGH OFF THE COAST
TO MISS GIVING THE FCST AREA A CHC FOR SIGNIFICANT PRCP. AT MOST,
UNDER THIS LATEST SCENARIO, THERE COULD BE SOME LGT SNOW ALONG THE
COAST. HIGH PRES FOLLOWS WITH SEASONABLY COLD AND DRY WX SUNDAY THRU
TUESDAY.
GENERALLY USED GFS40...HPC QPF /WHICH WAS A GOOD COMPROMISE BETWEEN
THE WETTER NAM AND DRIER GFS/ AND A BLEND OF MAV AND MET MOS FOR
TEMPS AND DEW POINTS FOR THURSDAY THRU FRIDAY AND USED GMOS WITH
SOME ADJUSTMENTS FOR THE REST OF THE LONG TERM FCST.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...VFR TODAY WITH IFR/LIFR CEILINGS DEVELOPING ACROSS
THE REGION AFTER MIDNIGHT.
LONG TERM /THURSDAY THROUGH SUNDAY/...IFR/LIFR WITH PRCP AND WIND
WITH IMPROVING CIG AND VSBY AS RN ENDS FROM SW TO NE ON THURSDAY.
CHC OF -SN WITH MVFR TO IFR CONDITIONS PSBL SATURDAY INTO SATURDAY
NGT...MAINLY ALONG THE COAST.
&&
.MARINE...
SHORT TERM...WILL BE UPGRADING GALE WATCHES TO WARNINGS STARTING
LATE TONIGHT.
LONG TERM /THURSDAY THROUGH SUNDAY/...GLW WILL EXTEND THRU ALL
DAY THURSDAY AS STRONG SE FLOW SHIFTS TO THE SW AS OCCLUDING FNT
MOVES THRU DURING THE DAY. FAIRLY STRONG WESTERLY FLOW BEHIND THIS
SYSTEM THURSDAY NIGHT THRU FRIDAY WITH SCA CONDITIONS
LIKELY...THEN WINDS LET UP AS WEAK AREA OF HIGH PRES BUILDS IN
FROM THE W. SEAS COME UP CONSIDERABLY THURSDAY WITH STRONG ONSHORE
FLOW...THEN SEAS ARE SLOW TO EASE UP DUE TO CONTINUED STRONG FLOW
THURSDAY NGT INTO FRIDAY.
&&
.TIDES/COASTAL FLOODING...
PORTLAND PREDICTED TIDE IS 11.1 FT AT 1104 AM THURSDAY. GFS SURGE
FCST SHOWS 0.8 FT AT THAT TIME WHICH PUTS PORTLAND TIDE VERY CLOSE
TO THE 12 FT FLOOD LEVEL. GFS STORM SURGE FCSTS USUALLY ON THE LOW
SIDE SO EXPECT MORE LIKE 1 TO 1.5 FT STORM SURGE PUSHING TIDE OVER
THE 12 FT FLOOD LEVEL. ALSO, EXPECT SOME SPLASHOVER FROM BUILDING
WAVES. THUS WILL PUT UP A COASTAL FLOOD WATCH FOR SATURDAY AROUND
THE TIME OF THE LATE MORNING HIGH TIDE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...COASTAL FLOOD WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR MEZ023>028.
NH...COASTAL FLOOD WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR NHZ014.
MARINE...GALE WARNING FROM 3 AM TO 7 PM EST THURSDAY FOR ANZ150>154.
&&
$$
