Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
1015 PM EST Thursday Dec 25 2014
strong low pressure will continue lifting across northern
Quebec overnight...as high pressure over the southeast states builds
into the region. Moisture from the Great Lakes will bring mostly
cloudy skies overnight and early Friday for areas near and north of
Interstate 90...with partly cloudy skies to the south. Clearing is
expected for Friday night and Saturday...before a cold front
approaching from the Great Lakes brings clouds and some showers for
Saturday night and Sunday.
Near term /until 6 am Friday morning/...
as of 945 PM EST...it was cloudy to mostly cloudy across the
region...with an area of mainly clear skies from the middle Hudson
Valley to Litchfield County CT. Have adjusted the sky cover grids
slightly to account for current conditions. Current temperatures still
running warmer than forecast...so have also adjusted the hourly temperature
grids and raised min temperatures for tonight a couple of degrees.
Surface winds continue to slowly diminishing this evening...but
during the past hour kpsf (pittsfield ma) had a peak wind gust to 45
miles per hour at 936 PM. Have followed the wind gusts minute by minute since
then...and there have been no further gusts over 32 miles per hour. In
addition...wind gusts at North Adams have been gusting to only
around 30 miles per hour this evening. Current forecast calls for gusts up to
30 miles per hour...so believe whatever caused the wind to increase at
Pittsfield has passed and winds will remain close to the current
forecast for the rest of the night.
for the bulk of tonight...we expect clouds to remain prevalent for
areas near and especially north of Interstate 90 through the night.
Latest nam12 and rap13 suggest that low level moisture streaming
from the Great Lakes region becomes trapped beneath strengthening
and lowering subsidence inversion in these areas...as depicted by
the model relative humidity values increasing to greater than 90-95 percent near
and slightly below h925. These models also handled the persistent
low cloud coverage last week. Some spotty light showers of snow
across higher elevations...and rain/drizzle in valleys...may
linger until midnight.
Across southern areas...such as the middle Hudson Valley and northwest
CT...have indicated partly cloudy skies...although there will
likely be some periods of mostly cloudy skies at times here as
well...with some possibility that the clouds lock in toward daybreak.
Based on the expectation of clouds and some wind through the
night...have went above the warmer met MOS for mins...with many
areas within the Mohawk and Hudson River valleys possibly
remaining above freezing. Across higher elevations...mins should
fall into the upper 20s to lower 30s.
Short term /6 am Friday morning through Sunday/...
Friday...main challenge will be if...and how quickly clouds erode
from south to north. It appears that the morning will be mostly
cloudy/clouds for most areas near and north of Interstate
90...with occasional clouds even to the south. There could even be
some flurries/snow grains across portions of the southern
Adirondacks. Then...as low level ridging begins to build in...and
the low level flow backs...we expect the southern edge of the
lower clouds to begin eroding from S to north during the midday
hours...and translating northward during the afternoon.
Unfortunately...this process could take until sunset across
portions of the southern Adirondacks and southern Vermont. Closer to
the I-90 corridor...it appears that sunshine should develop during
the early to middle afternoon hours. South of I-90...after occasional
morning clouds...expect mostly sunny skies for the afternoon. Maximum
temperatures should reach the Lower/Middle 40s in valleys...and 35-40 across
higher elevations. Some upper 40s to near 50 degree temperatures could
occur in portions of the middle Hudson Valley.
Friday nt...it appears that the best chance for clearing in all areas
should be Friday evening...before lower clouds possibly begin
expanding southward once again across the southern
Adirondacks...and possibly as far S as I-90 toward daybreak Sat.
Otherwise...expect min temperatures to be a bit cooler than tonight/Friday
am given the prospects for more breaks in the clouds and fairly
light winds...min temperatures should fall into the 20s to lower 30s in
Sat-sun...a cold front will slowly approach from the Great Lakes
region late Sat nt...and cross through the region Sunday. Clouds
should increase from northwest to southeast during Sat...with showers of mainly
rain developing Sat nt into at least Sunday morning. Depending on
surface temperatures Sat nt...there is a remote possibility of isolated
patches of freezing rain across portions of the Adirondacks...but
it appears at this time that most min temperatures should hold just above
freezing...or may rise above freezing at the time any rain showers
develop. During Sunday...as colder air seeps
southward...lingering rain showers may change to snow before
ending across the southern Adirondacks and higher elevations
across southern Vermont. Maximum temperatures on Sat should reach the Lower/Middle
40s in valleys and upper 30s across higher elevations. Sat nt/sun
am mins should fall into the Lower/Middle 30s...but mainly above the
freezing mark. Sun maximum temperatures should reach the upper 30s to lower
40s before falling later in the day.
Long term /Sunday night through Thursday/...
after a long period of above normal temperatures...the long term period
will feature a return to normally cold temperatures and mainly dry weather.
The long term period will be dominated by the eastern extension of a
massive 1050+ mb high pressure system over The Rockies. This will
result in seasonably cold and mainly dry weather with any
significant weather systems remaining to the south and north of the
Albany forecast area. Any now snow shower activity that does occur
will be the result of some lake effect and upper level trofiness
over the region. Much of the region will be forecast to be dry
during the long term period...but higher terrain areas and areas
downwind of Lake Ontario will have 20 to 40 percent probability of precipitation forecast
Monday night through Thursday.
Highs during the period will be in the middle 20s to middle 30s on
Monday...lowering to the 20s and lower 30s Tuesday through Thursday.
Lows Sunday night will be in the upper teens and 20s...the teens to
lower 20s Monday night...5 to 20 degrees Tuesday night...and the
teens to lower 20s Wednesday night.
Aviation /00z Friday through Tuesday/...
expect a VFR cloud deck to prevail at the kgfl/kalb/kpsf for most of
the taf period ending at 00z Saturday. Toward the end ofthe taf
period the clouds should become scattered. At kpou expect scattered/broken VFR
clouds through the taf period.
Westerly surface winds early in the taf period will continue to gust
to between 20 and 30 kts. Later tonight...any wind gusts will
decrease to 20 kts or less. On Friday surface winds will become more
southwesterly at the taf sites with gusts only up to around 15 kts
expected...with winds becoming light after 22z Friday.
Friday night: no operational impact. No sig weather.
Saturday: no operational impact. No sig weather.
Saturday night: slight chance of rain showers.
Sunday: moderate operational impact. Chance of rain showers.
Sunday night: no operational impact. No sig weather.
Monday: low operational impact. Slight chance of shsn.
Monday night: low operational impact. Slight chance of shsn.
Tuesday: no operational impact. No sig weather.
a Flood Warning has been issued for The Mettawee river at Granville
for moderate flooding...and for minor flooding for the Mohawk
River at Utica. Otherwise...most other river points have either
crested...or will shortly.
Other than scattered rain/snow showers tonight...drier weather is
expected through Saturday. This should allow for river levels to
Additional light showers of mainly rain are expected for Sat nt
into sun...with rainfall amts generally remaining under one
quarter of an inch. This should have minimal impacts on area
rivers and streams.
For details on specific area rivers and lakes...including observed
and forecast river stages and lake elevations...please visit the
advanced hydrologic prediction service /ahps/ graphs on our website.