Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
1258 am EST Thursday Nov 27 2014
a coastal low will move northeast of Cape Cod
tonight...and into the Canadian Maritimes by Thanksgiving
afternoon. Periods of moderate to heavy snow will continue
tonight...before tapering to scattered snow showers and flurries
after midnight. An upper level disturbance will bring some
scattered snow showers to region tomorrow afternoon into
Thanksgiving night. High pressure will ridge in briefly for Friday
with below normal temperatures.
Near term /until 6 am this morning/...
Winter Storm Warning continues for much of the forecast
area...except for northern Herkimer counties until 7 am
Winter Weather Advisory continues for northern Herkimer County until
7 am EST Thursday...
This update is to add Hamilton County to the Winter Storm
Winter has arrived on Thanksgiving evening...with the first big
coastal Nor'easter for the 2014-15 season!
Upper deformation zone snows now occurring over eastern New York and
western New England. Very narrow enhanced bands with brief bursts
of dryer and fluffier snow and some mixed graupel are building
east. Strong north to north northeast winds from the surface
through the boundary layer parallel to the boundary layer thermal
gradient are likely lining up the bands within the enhanced zone
of frontogenesis and continued cooling aloft. The back edge of
the parallel snow bands is entering the eastern Catskills...
Schoharie valley...central Mohawk Valley and southeastern
Based on the radar and satellite trends...the brief heavy snow
and graupel bursts should end in the capital district...Lake
George Saratoga region and middle Hudson Valley by midnight...and
western New England around or just after midnight. There is an
large areas of very light snow behind the upper deformation
area...but once the heavier snow and graupel bursts have moved
out...very little additional accumulation can be expected.
So...updating the forecast through tonight to reflect these trends
and keeping all headlines as is until even the trailing light snow
The snow should taper to scattered snow showers by daybreak as the
cyclone moves east of the Gulf of Maine...and all the precipitation should
diminish to snow showers and flurries between 09z-12z...but we will
have to monitor for Mohawk-Hudson convergence.
Lows tonight will be in the middle and upper 20s with teens to l20s
over the southern dacks...and southern greens. The winds will be brisk out
of the north to northwest at 10 to 20 miles per hour.
Short term /6 am this morning through Friday night/...
Thanksgiving...a brief lull in the snow showers will occur...as
the cyclone pulls away into the Canadian Maritimes. However...an
upper level low will approach during the afternoon. A weak short-
wave associated with the upper level low will trigger some isolated-
scattered snow showers in the afternoon with some light snow accums of a
coating to a half an inch. Highs will be in the m20s to m30s
across most of the region.
Thanksgiving night...a better chance of snow showers for most of the
region with the weak disturbance. Some westerly upslope snow
showers may yield some light accumulations along the western slopes of
the southern greens...and western dacks...and Taconics. Weak cold advection
will occur in the wake of the short-wave. Lows will be in the
teens to l20s.
Friday-Friday night...the GFS/NAM shows some ridging building in
across the region on the busy shopping day. The scattered showers and
flurries should end prior to noon west of the Hudson River valley.
Partly sunny and cold conditions are expected during the day. Highs
will generally be in the lower to middle 30s in the valleys...and
m20s to l30s over the hills and mountains a quick shot of radiational
cooling is expected with the surface high overhead with temperatures falling
into the teens and single digits. The next weak short-wave in the
flattening middle-level flow approaches Friday night with some light
snow or scattered snow showers north and west of the capital region between
Long term /Saturday through Wednesday/...
much of the long term period will be characterized by unsettled
weather before improving conditions early next week.
At the start of the long term period...the forecast area will be
underneath a northwest flow regime that will be deamplifying and
becoming zonal throughout the weekend. In this developing zonal flow
regime aloft...pieces of northern stream upper-level energy will be
quickly moving through as a low pressure system skirts northwest of
the region. A warm front associated with this low pressure system
will approach the forecast area Saturday...with warm air advection
rain/snow showers possibly breaking out ahead of it especially north
and west of the capital region. Not much moisture and dynamics will
be associated with this feature...so any rain/snow showers will be
scattered in nature. This warm front will help usher in a slightly
milder airmass with temperatures expected to warm into the 40s for
most locations Sunday.
The best chance for rain/snow showers looks to occur late Sunday
into early Monday morning ahead of a fairly strong cold front.
Higher terrain locations especially north and west of the capital
region may receive an inch or two of snowfall ahead of the cold
frontal passage. High pressure looks to build across the region to
start next week behind the cold frontal passage.
High temperatures throughout the long term period will range from
the upper 20s to middle 30s Saturday...before warming into the 40s
Sunday...upper 30s to low 40s Monday...upper 20s to middle 30s Tuesday
and upper 30s to low 40s Monday through Wednesday. Low temperatures
will range from the middle 20s to low 30s Saturday night...upper 20s to
middle 30s Sunday night and upper teens to middle 20s Monday and Tuesday
Aviation /06z Thursday through Monday/...
snow is slowly winding down...but will continue for at least a
couple of more hours at the taf sites. Brief improvement to VFR
conditions expected after sunrise today for the valley taf
sites...with continued MVFR at kpsf. A vigorous cold upper level
trough brings another chance for snow later Thanksgiving day to
the area with MVFR conditions expected at all the taf sites by
sunset. A light accumulating snow is again possible later
Thanksgiving day and evening.
Winds will be northwesterly tonight and decrease to less than 10
kts by late tonight...and continue through Thursday.
Thursday night: moderate operational impact. Chance of shsn.
Friday: no operational impact. No sig weather.
Friday night: no operational impact. No sig weather.
Saturday: low operational impact. Slight chance of rain showers...shsn.
Saturday night: low operational impact. Slight chance of shsn.
Sunday: low operational impact. Slight chance of rain showers...shsn.
Sunday night: moderate operational impact. Chance of rain showers...shsn.
Monday: low operational impact. Slight chance of rain showers...shsn.
no significant hydrologic problems are expected through the
Widespread snowfall will occur...as coastal low impacts region
tonight into Thanksgiving morning. Total quantitative precipitation forecast of 0.50 inches to
1.25 inches with this system.
Milder temperatures are possible Sunday with some snow melt. However...
temperatures are expected to be in the middle 30s and colder Saturday
night and Sunday night so melt will stop.
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
CT...Winter Storm Warning until 7 am EST this morning for ctz001-
New York...Winter Storm Warning until 7 am EST this morning for nyz033-
Winter Weather Advisory until 7 am EST this morning for nyz032.
Massachusetts...Winter Storm Warning until 7 am EST this morning for maz001-
Vermont...Winter Storm Warning until 7 am EST this morning for