FXUS61 KGYX 220311
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1011 PM EST MON DEC 21 2009
.SYNOPSIS...
A NORTHWEST FLOW WILL CONTINUE THROUGH THURSDAY...AND WILL PROVIDE
A THREAT OF LIGHT SNOW OR SNOW SHOWERS...MAINLY IN THE MOUNTAINS
AND IN THE PENOBSCOT AND KENNEBEC VALLEY REGIONS. WARMER AND MORE
MOIST AIR WILL STREAM NORTHWARD FRIDAY INTO SATURDAY AS AN AREA OF
LOW PRESSURE MOVES THROUGH THE GREAT LAKES. THIS WILL BRING SOME
SNOW OR RAIN INTO THE REGION LATE IN THE DAY ON
CHRISTMAS...CONTINUING INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WILL UPDATE TO INPUT LATEST OBSERVED DATA. BASED ON LATEST RADAR
AND METAR REPORTS SHOWING SCT -SHSN ACTIVITY ACROSS PORTIONS OF
WRN/SRN MAINE WILL CONT THE SLGT CHC TO CHC OF -SHSN OVERNIGHT. A
FEW OTHER MINOR TWEAKS BASED ON LATEST OBSERVED DATA OTRW NO
CHANGES IN NEAR TERM FCST. NOT EXPECTING ANY ACCUMULATION FROM
-SHSN...JUST TRACE AMOUNTS FOR THE MOST PART.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
FORECAST BECOMES LOWER CONFIDENCE ON TUESDAY...AS ELONGATED 500 MB
LOW APPROACHES FROM THE WEST...WITH EVEN MORE ELONGATED STRIP OF
VORTICITY EXTENDING EWD THROUGH IT. THIS WILL LIMIT DYNAMICS AT
FIRST...BUT AS THIS LOW BEGINS TO INTERACT WITH 500MB LOW TO THE
EAST...AND GETS A SURGE OF MOISTURE AND WARM AIR ADVECTION FROM
THE NORTHEAST /ROTATING AROUND THE LOW EAST OF THE MARITIMES/...WE
SHOULD START TO SEE AN INCREASE IN SHSN OR EVEN SOME OCCNL LIGHT
SNOW BEGIN TO BREAK OUT ACROSS THE ERN ZONES AND THE MTNS DURING
THE AFTERNOON. EAST AND SOUTH OF THE KENNEBEC VLY IN ME...SUNSHINE
WILL START THE DAY BUT WILL SEE CLOUDS THICKEN AND LOWER DURING
THE DAY. IN SRN NH...SHOULD STAY AT LEAST P/SUNNY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A COUPLE OF THINGS TO BE CONCERNED WITH OVER THE NEXT FEW DAYS.
FIRST IS THE WAA SNOW THAT WILL COME ON A NE FLOW. MODELS SEEM TO
BE IN AGREEMENT ON THIS BUT THINK THE PRECIPITATION IS OVERDONE.
THE HEAVIEST PRECIPITATION WILL REMAIN TO THE EAST OF OUR CWA. FOR
TUES NIGHT WILL RAISE POPS TO LIKELY OR CATEGORICAL NORTH AND
EAST OF PWM AND THEN DROP BACK TO CHC EVERYWHERE WED NIGHT.
SKIES BECAME PC BY THURSDAY AND FRI BEFORE NEXT SYSTEM MOVES IN
LATE FRI NIGHT. IT WILL BE INITIALLY COLD ENOUGH FOR SNOW WHEN
PRECIP STARTS EARLY SAT MORN. PRECIP WILL CHANGE TO RAIN IN SRN
AREAS WITH A MIX IN THE MTNS. A FEW INCHES OF ACCUMULATION IS PSBL
ESPECIALLY IN THE MTNS SAT.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...VFR WITH BRIEF MVFR CIG AND VSBY
PSBL WITH ANY -SHSN AT AUG AND TO A LESSER CHC AT PWM TNGT. CIG
AND VSBY LWR /TO MVFR/ FROM THE NE ON TUESDAY FROM MARITIME SYSTEM
WRAPPING ITS INFLUENCE BACK INTO THE REGION ALONG WITH APPROACHING
UPR LVL SYSTEM FROM CENTRAL CANADA. THIS WILL IMPACT AUG THEN PWM
BY THE END OF THE DAY.
LONG TERM...FOR TUES NIGHT EXPECT VFR CONDITIONS TO DETERIORATE TO
MVFR AND PSBL IFR AT AUG. EXPECT VFR AT OTHER TAF LOCATIONS WITH
OCCASIONAL MVFR AT PWM FOR CEILING AND VSBY.
&&
.MARINE...
SHORT TERM /TONIGHT THROUGH TUESDAY/...WILL UPDATE TO INPUT LATEST
OBSERVED DATA. ONLY A FEW MINOR ADJUSTMENTS BUT OVERALL FCST REMAINS
THE SAME WITH SCA CONTINUING THRU THE NGT. CONDITIONS EASE UP JUST
BLO SCA LEVELS FOR TUESDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR ANZ150>154.
&&
$$
