377 
fxus61 kaly 081506 
afdaly 


Area forecast discussion 
National Weather Service Albany New York 
1006 am EST Thursday Jan 8 2009 


Synopsis... 
low pressure will continue to track northeastward through the 
Canadian Maritimes today...with a moist cyclonic west to northwest 
flow bringing snow showers to east central New York and adjacent 
western New England. Weak high pressure will build in tonight and 
Friday...before the next low pressure system approaches from the 
Midwest on Saturday. 


&& 


Near term /until 6 PM this evening/... 
moist cyclonic flow has produced multiple bands of Lake/Lake enhanced 
snowfall. One impressive band of lake effect snow with a multiple 
lake connection has extended down the Mohawk Valley...through the 
greater capital region...and into southern Vermont...and central New England. 
We received a report of 1.8 inches of snow in a little over an 
hour in Round Lake...Saratoga County. Also...another report came 
in of 1-1.5 inches in Stillwater. We believe the southern Vermont westerly 
upslope region is getting hammered based on the radar returns. We 
have issued a Winter Weather Advisory for 3-6 inches until 6 PM there 
(excluding eastern Windham county). 


Further upstream...we have issued a lake effect Snow Advisory for 
the west-central Mohawk Valley for 3-6 inches of snow. For the eastern 
Mohawk Valley...capital region...Saratoga region...we believe 1-4 
inches will cover it. Other snow showers have started popping up 
over the southern tier too. The ruc40 shows a short wave trough moving 
through producing the diffuse activity there. In the 
afternoon...the band will shift north and be disrupted...and the lowering 
inversion will diminish the activity to light snow showers and 
flurries. 


We increased probability of precipitation to likely prior to noontime...south of the 
capital region. We decrease them in the afternoon. 


The winds will increase from the west/northwest in the afternoon at 15 to 25 
miles per hour in the wake of the trough passage. 


&& 


Short term /6 PM this evening through Saturday night/... 
snow showers should tend to wind down this evening as flow becomes 
a bit more anticyclonic and inversion heights lower further. Kept 
chance probability of precipitation west of the Hudson Valley this evening...with snow 
showers ending overnight. Min temperatures tonight close to seasonal 
averages. 


Friday should feature dry but chilly conditions as weak high pressure 
builds in. Most areas should experience at least partly sunny 
skies...with more in the way of sunshine south of Albany. Temperatures 
only in the teens across the mountains...with mainly 20s in the 
valleys. Dry weather to continue Friday night with the high overhead. 
Latest guidance...despite considerable disagreement for the Sat 
and Sat night time frame...all showing dry conditions through Friday 
night. So will remove mention of any probability of precipitation through 12z Sat. 


Very low confidence forecast for the Sat and Sat night period...as 
model guidance quite divergent with a system developing in the 
Midwest and intensifying as it heads eastward. The GFS has been 
consistent in showing a southerly track from the virginias to the 
New Jersey coast...which would result in mainly light snow event across 
our area from Sat afternoon through Sat night. The NAM is slower 
in timing with precipitation arriving later...with a more northerly track 
across PA to southern New York then transferring energy to the coast 
over Long Island. This results in more quantitative precipitation forecast and a warmer temperature 
profile that could lead to mixed precipitation across southern areas. The 
European model (ecmwf) which is typically more consistent has drastically shifted 
its track on the 00z run to be more in line with the NAM...although 
faster with arrival of precipitation. So quite a range of solutions...and 
with the the sref/mref camps resembling their operational 
counterparts there is a great amount of uncertainty at this time. 
For now will mention low likely probability of precipitation south of Albany...with 40-50 
percent elsewhere. Too early to pinpoint snowfall amounts due to 
uncertainty with the storm track...although light to perhaps 
moderate snow will be possible for at least part of the area. 


&& 


Long term /Sunday through Wednesday/... 
surface ridge briefly builds into region Sunday and Sunday night. 
However...aloft region remains under a long wave trough with another 
short wave diving out of western Canada into the northern plains and 
Upper Middle west. This energy will spin up another low pressure system 
which will impact our region Monday and Monday night...will be cold 
enough for snow. The upper level low will move across region Tuesday 
along with a reinforcing cold front ushering a colder airmass. Deep 
cyclonic flow for Wednesday. All this keeps snow showers in the 
forecast especially across the higher terrain north and west of the 
capital region. Looking ahead into next weekend...region will remain 
under a long wave trough. 


&& 


Aviation /15z Thursday through Monday/... 
low pressure areas have consolidated and are moving northeast 
into the Canadian Maritimes resulting in deep cyclonic flow across 
region. The upper level trough axis will move over region today. 
His will result in scattered to numerous snow showers across 
area. Have indicated threat with vicinity showers in kalb and kgfl 
tafs along with scattered MVFR height clouds. VFR conditions are 
expected at kpou through taf period. Winds will increase and 
become gusty this morning from the west-southwest becoming more westerly this 
afternoon. Westerly winds will begin to weaken this evening. 


Outlook... 
Friday...VFR...no sig weather. 
Sat...MVFR-IFR with snow likely south of the capital district 
during the afternoon. Otherwise VFR-MVFR with a chance of of 
snow. 
Sat night...VFR-MVFR chance of snow. 
Sun...VFR...no sig weather. 
Monday...VFR-MVFR...chance of snow. 


&& 


Hydrology... 
few...if any...hydrology related problems are expected through the 
weekend and into the coming week. 


Seasonable temperatures into early next week with an Arctic airmass 
expected for middle week. Ice will form and thicken especially early 
next week as temperatures plunge well below freezing and it may get 
cold enough across the Adirondacks and southern Vermont for some 
isolated freeze up river ice jams to form by Tuesday. Increased flow 
on the Housatonic may move some ice between Bulls Bridge and the 
upstream end of Lake Lillinonah...but little change is likely 
upstream of Bulls Bridge. 


Snow water equivalent data from field surveys is expected this week. 
Our initial 08-09 winter Spring flood potential outlook will be 
issued on Friday Jan 9th. 


For details on the rivers...please visit the advanced hydrologic 
prediction service /ahps/ graphs on our website. 


&& 


Aly watches/warnings/advisories... 
CT...none. 
New York...Lake effect Snow Advisory until 6 PM EST this afternoon for 
nyz038>040-082. 
Massachusetts...none. 
Vermont...Winter Weather Advisory until 6 PM EST this afternoon for 
vtz013-014. 


&& 


$$ 
Synopsis...jpv 
near term...taw 
short term...jpv 
long term...iaa 
aviation...iaa 
hydrology...iaa 

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