014 
fxus61 kbgm 211632 
afdbgm 


Area forecast discussion 
National Weather Service Binghamton New York 
1132 am EST Sat Nov 21 2009 


Synopsis... 
a moist northwesterly flow of air will keep our skies generally cloudy 
today. On Sunday, an area of high pressure now located over the 
Ohio Valley will build overhead helping to clear out the clouds 
making for a bright end to the weekend. 


&& 


Near term /through tonight/... 
northwest flow combined with a shallow layer of moisture will keep 
area generally cloudy this afternoon with some improvement late. 
Maxes will be around 50. Current forecast in great shape with only 
minor adjacent made. 


The often moisture laden NAM keeps in moisture through tonight 
while the GFS seems to have a better idea by thinning out the deck 
of clouds gradually. The key word tonight will be gradually as 
even the more optimistic GFS does not show drying below the 
inversion until after 06z. 


&& 


Short term /Sunday through Monday night/... 
as of 250 am...Sunday will be the pay off day of the weekend with a 
surface high pressure system building right overhead. Any 
lingering clouds from the overnight will quickly be a distant 
memory with a sun filled day. While abundant sunshine is expected 
both the NAM and GFS show US barely mixing to 925 mb and with hp 
in control winds will be very light. Adding to the temperature forecast 
problem Sunday is the fact that the GFS and NAM are about 3c apart 
on 925 mb temperature forecasts. The GFS with 925s around 5 or 6 is 
suggestive of highs in the middle 50s while the NAM is closer to 
50 again with 925s around 3. I split the difference for now but my 
gut says despite the sunshine the cooler met guidance will be more 
accurate given the limited mixing potential (light winds, low 
inversion). 


Forecast problems begin by Monday as the models are having trouble 
trying to resolve the 500 trough now over southeast Texas. The GFS 
seems to be the outlier in bringing in moisture on 
Monday...by keeping the 500 trough much stronger. The other 
models...especially the Gem and NAM keep the 500 trough more of an 
open wave and focus more on the potential coastal development off 
the Delaware-Maryland-Virginia. This would keep the bulk of the moisture to our 
east through Monday evening. A blend between the NAM and Gem was 
used with some showers possible late in the day from nepa up 
through the Catskills. The new Euro is in and seems to be a 
compromise between the GFS Camp and the Gem/NAM keep by keeping 
the wave more open (like the NAM/Gem models) but still showing 
some moisture in our area. Overall the idea remains the 
same...best chances for moisture will be the farther south/east 
you go. 


&& 


Long term /Tuesday through Friday/... 
updated as of 101 am...no appreciable changes to the forecast this 
period. 


Model consensus still indicates that the majority of the rainfall 
with the surface wave off the East Coast on Tuesday will stay 
east of the forecast area...so only slight chance probabilities 
look good from this Vantage Point. 


The start of the Holiday period from Wednesday through Friday 
still carries plenty of forecast uncertainty at this time. 
Overall...longer range guidance is leaning towards a slower onset 
of precipitation (more like on Thanksgiving day or Thanksgiving 
night)...with Wednesday mainly dry. The GFS...however...is much 
faster in carrying energy eastward into our neck of the Woods by 
Wednesday...with showers beginning at that point. Given all the 
model discrepancies...won't tinker much with our going 
forecast...which does mention at least a low chance of showers on 
Wednesday. One well agreed upon scenario is that Wednesday and 
Thanksgiving day will continue to feature mild temperatures. 


By Friday...it appears that colder air will begin to filter 
in...as a storm system winds up offshore. This would likely 
result in some lake response...with a good shot of rain and snow 
showers. 


&& 


Aviation /18z Saturday through Thursday/... 
for ksyr...krme...kith...and kbgm...MVFR ceiling restrictions 
anticipated for most of the day. Late this afternoon and early 
evening...clearing skies anticipated...with a return to VFR at 
that point. 


West to northwest winds 5-10 knots today...turning light and 
variable after sunset. 


At kelm...after a period of MVFR ceilings this morning...cloud bases 
should lift enough to allow a return to VFR this afternoon and 
evening. IFR conditions in fog could develop towards daybreak Sunday. 


West to northwest winds 5-10 knots today...turning light and 
variable after sunset. 


For kavp...mainly VFR expected through 12z Sunday. A very brief period 
of MVFR ceilings possible early this morning. 


Northwest winds 5-10 knots today...will turn light overnight. 


Outlook... 


Sat night...some MVFR ceilings possible. 
Sun/Sun night...VFR. 
Monday/Monday night...MVFR possible in showers. 
Tuesday/Wednesday...VFR. 


&& 


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


&& 


$$ 
Synopsis...emh/rrm 
near term...emh/rrm 
short term...emh 
long term...mlj/rrm 
aviation...mlj