113 
fxus61 kgyx 211501 
afdgyx 


Area forecast discussion 
National Weather Service Gray ME 
1001 am EST Sat Nov 21 2009 


Synopsis... 
a weak surface trough will exit the coast this morning. High pressure 
over the Ohio Valley will build east across the area late today through 
early Monday. An east to southeast flow will develop as the high moves 
into the Maritimes on Monday...then continue through middle week. Low pressure 
will track from the Great Lakes northeastward into eastern Canada 
Wednesday and Thursday pulling an associated cold front across our 
area on Thursday. 


&& 


Near term /until 6 PM this evening/... 
a weak surface trough situated along the coastal plain will exit 
the coast shortly. Satellite showed lingering low clouds across 
northern and western sections...with patches of thicker high 
cloud streaking eastward across the entire area. The 12z radiosonde observation was 
dry in the low layers at kgyx...but the radiosonde observations from kcar...and 
to a lesser extent kalb...showed low level moisture trapped beneath 
the subsidence inversion which suggests broken low clouds should 
persist across the northern and western sections for much of the 
daylight hours. I made adjustments to 1st period grids based on 
satellite trends and mesonet. 


Previous disc... 
as surface high pressure approaches from the west...pressure gradient 
will slacken and winds will west-northwest flow will drop off. Upslope 
effects will weaken during the afternoon...with clouds diminishing 
in the mountains elsewhere...downslope should keep thing party-mostly 
sunny with seasonably mild temperatures...in the middle-upper 50s. 


&& 


Short term /6 PM this evening through 6 am Sunday/... 
surface high will slide closer and clear skies and light winds should 
allow for some rad cooling...but airmass remains mild...and 
although lows will be cooler...they will still be above normal. 


&& 


Long term /Sunday through Friday/... 
as the weekend high pressure system moves into the Maritimes Sunday 
night...an easterly flow will develop and begin to moisten up the 
air mass on Monday. Cloud cover will increase Monday night with a 
chance of showers across the region through Wednesday night. A weak 
ridge of high pressure will dry the region out a bit for Thursday 
but a weak low level onshore flow will keep clouds and a 
minimal chance of a shower in the forecast for Thanksgiving day. 
A middle Atlantic coastal storm will then move up the coast Thursday 
night and intensify as it moves along the New England coast. This 
will bring a chance of rain or snow to northern and mountain sections 
and a chance of rain to southern and coastal sections on Friday. 
Temperatures will start out Sunday some 5 to 10 degrees above normal 
and slowly retreat back to near normal by the end of the workweek. 


&& 


Aviation /15z Saturday through Wednesday/... 
short term...MVFR ceiling at kleb will gradually lift through early 
afternoon...otherwise VFR expected through tonight. 


Long term...VFR conditions Sunday through Monday night...lowering to 
MVFR to IFR in any showers Tuesday into Wednesday. 


&& 


Marine... 
short term...trend of winds and seas is downward with the small 
craft dropped with the middle morning update. 


Long term...conditions below Small Craft Advisory criteria Sunday through Tuesday. 
Small Craft Advisory criteria for winds/seas possible Wednesday. 


&& 


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


&& 


$$