632 
fxus61 kbgm 212021 
afdbgm 


Area forecast discussion 
National Weather Service Binghamton New York 
321 PM EST Sat Nov 21 2009 


Synopsis... 
a moist northwesterly flow will keep our skies generally cloudy 
overnight. High pressure will build over the region on Sunday 
making for a partly to mostly sunny afternoon. Fair weather will 
continue through much of Monday as high pressure gradually moves 
northeast into Nova Scotia. 


&& 


Near term /until 6 am Sunday morning/... 
abundant low level moisture trapped under a subsidence inversion 
will result in cloudy skies for the overnight period. With light 
northwest flow conditions will be slowest to improve across the 
upslope areas primarily the Susquehanna region with the lake 
plain and NE PA seeing improving conditions possibly toward 
daybreak. 


With overcast skies went several degrees above MOS guidance, 
basically middle to upper 30s, with temperatures around 40 in the lake plain. 


&& 


Short term /6 am Sunday morning through Tuesday/... 
light northerly flow associated with high pressure over Quebec 
will bring dryer air south across the area on Sunday. Left over 
clouds trapped beneath the inversion Sunday morning should 
dissipate in most areas by afternoon as dry air filters in. Some 
light downslope south of the Adirondack Mountains will aid the 
clearing early Sunday in the Mohawk Valley. 


Quiet weather will continue on Sunday night into Monday with clear 
skies and continued above normal temperatures. GFS/NAM/ECMWF and 
Gem are all in agreement that the next chance for precipitation 
will be late Monday into Tuesday as a weak wave of low pressure 
moves up the middle-Atlantic coast toward New England. This morning's 
sref's indicate a 50 to 60 percent chance for some light rain with 
this wave Monday night into Tuesday... with the highest chances 
over northeast PA. Based on this have edged probability of precipitation up from low chance 
to high chance during that period. 


&& 


Long term /Tuesday night through Saturday/... 
today/S medium range models are all over the place during this 
period. HPC favors a European model (ecmwf)/ensemble blend and will thus strictly 
follow their guidance with only minor modification. These solutions 
suggest that a deep trough will move out of the central US during the 
Wednesday-Thursday time frame and gradually move through the east Fri-Sat. 
Initially the trends look a little slower than earlier models...and 
have trimmed back probability of precipitation for Tuesday night before allowing chance probability of precipitation to 
cover the rest of the week due to high level of uncertainty. 
Cny/nepa remains on the mild side of the system with mainly rain as 
the ptype. Then the air looks to become cold enough on northwesterly flow Friday 
night and Saturday for potential les. To account for this...we have 
increased precipitation chances above guidance over the lake prone 
vectors from 270-300 degrees. 


&& 


Aviation /20z Saturday through Thursday/... 
weak northwest flow combined with a shallow layer of moisture will 
keep mainly MVFR ceilings across terminals through middle morning Sunday. 
At ksyr/kelm/kavp, conditions may improve to VFR with ceilings around 
3,500 feet this evening but MVFR ceilings are again likely by the way 08z-12z. 
By middle morning Sunday conditions should improve to VFR with scattered/broken 
clouds around 4k feet. 


Northwest winds around 5 knots becoming light and variable after 
sunset. Light and variable winds on Sunday or light north-northeast. 


Outlook... 


Sun ngt/Monday...VFR. 
Monday ngt/Tuesday...MVFR possible in showers. 
Tuesday night through Wednesday night...VFR. 
Thursday...MVFR in showers. 


&& 


Bgm watches/warnings/advisories... 
PA...none. 
New York...none. 


&& 


$$ 
Synopsis...rrm 
near term...rrm 
short term...mse 
long term...jab 
aviation...rrm