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fxus61 kgyx 210309 
afdgyx 


Area forecast discussion 
National Weather Service Gray ME 
1009 PM EST Thursday Nov 20 2008 


Synopsis... 
low pressure will develop southeast of Cape Cod Friday and intensify 
rapidly as it moves northeast into Canadian maritime provinces 
Saturday. This will usher in some more very cold air for the 
weekend on a strong northwesterly wind. High pressure will move 
south of New England Sunday afternoon and early Monday allowing 
some warmer air to try and move in. Monday afternoon a cold front 
will approach the region as low pressure develops south of New 
England and moves north into southern Canada Tuesday. High 
pressure builds in Wednesday and Thanksgiving day. 


&& 


Near term /until 7 am Friday morning/... 
10 PM update...only real change to overnight forecast was to 
adjust min temperatures...clouds in the mountains...and some lingering surface 
flow...have kept temperatures up a bit higher...so have tweaked up a 
couple degrees across the board. In the mountains...however...looks 
like clouds will linger through most of the night...and rad cooling 
will be slowed so bumped up mins by 3-5 degrees there. Otherwise 
no changes. 


Previous disc...temperature forecast is the biggest challenge tonight 
with upslope clouds expected to stick in the higher terrain. 
Lowland elevations should radiate efficiently as winds 
decouple...thus we have dropped forecast min temperatures some 2-5 
degrees below GFS MOS guidance away from the coast. Scattered 
flurries are expected in the higher terrain...but moisture is so 
scant accumulations are unlikely. 


&& 


Short term /7 am Friday morning through 6 PM Friday/... 
again tomorrow the nwp guidance may be too warm given its handling 
of temperatures today. Would be surprised to see many locations 
away from the immediate coast reach above freezing. Have again 
gone with upslope flurries and clouds thanks to northwest flow 
continuing. Wind speeds are expected to be slightly lower than 
todays. 


&& 


Long term /Friday night through Thursday/... 
models air fairly similar over the next several days. Both GFS and 
European model (ecmwf) develop strong low pressure well east of Maine and move it 
into Nova Scotia. This will usher in some more very cold air this 
weekend. Based on this last bout of cold air I have lowered mav 
guidance by about 5 degrees for highs on Sat and 2 or 3 degrees 
for low temperatures. Sat will be very cold and blustery with temperatures 
staying in the 20s with teens in the mountains 


On Sunday temperatures moderate a bit and the wind relaxes. High pressure 
will move S of New England turning the winds to the west and SW. 


A warm front moves north of the region Monday allowing temperatures to 
warm into the lower 40s S and 30s north. 


A cold front approaches Monday afternoon with the models 
indicating a secondary low forming over southern New England. 
Precipitation type will be a problem with this system. Expect precipitation will 
start as light snow late Monday. The mountains may stay with snow as the 
coast changes to rain at some point. These details will have to be 
worked out later. There will be a strong southeast low level jet bringing 
lots of moisture off the Atlantic so expect a fairly heavy precipitation event. 


High pressure builds in Wednesday and Thursday. Models hinting at 
another significant system next weekend. 


&& 


Aviation /03z Friday through Tuesday/... 
VFR through Friday. 


Long term...expect mostly VFR through Sunday. May see MVFR ceilings as 
warm front moves through Monday. Conditions deteriorate to IFR Monday 
night. 


&& 


Marine... 
short term...seeing a few borderline Small Craft Advisory gusts...especially at the 
C-man sites of Isle of Shoals and Matinicus...but the trend over 
the last 2 hours has been downward...and this will continue 
overnight into Friday...so no flags expected through Friday. 


Long term...will likely need Small Craft Advisory for Sat as low pressure develops NE 
of the area with Small Craft Advisory winds continuing into early sun. A Gale 
Warning may be needed late Monday and Tuesday. 


&& 


Gyx watches/warnings/advisories... 
ME...none. 
New Hampshire...none. 
Marine...none. 


&& 


$$ 
Synopsis... 
near term...cempa 
short term... 
long term... 
aviation... 
marine...cempa