Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
950 PM EST Friday Feb 12 2016
an Arctic cold front will sweep across the region
overnight with scattered snow showers and isolated snow squalls
ahead of it. Behind the Arctic cold front...the coldest airmass of
the season will build across the region for the weekend with
bitterly cold temperatures and wind chills. A storm system may
impact the region Monday into the middle week.
Near term /until 6 am Saturday morning/...
as of 949 PM EST...an Arctic cold front will be moving through
the region between 04z /11 PM/ and 10z /5 am/ from northwest to southeast. Ahead of
this frontal boundary there will be scattered snow showers and
perhaps a few embedded snow squalls...especially north and west of
the capital region. The latest 3-km hrrr shows the current band of
snow showers currently west of the forecast on the local and mosaic
radar imagery moving into the Mohawk Valley...Adirondacks...and
Catskills...and then weakening as it moves further down stream
towards the Hudson River valley. Snowfall amounts are expected to
be on the light side with generally a dusting to 2 inches. The
higher totals will be over the western dacks. Any snow squalls would
likely reduce visibilities to under a quarter mile briefly for a
short period of time. Some changes were made to the
probability of precipitation/clouds/temps based on the latest hrrr and nam12.
It will be another very cold night...but not as cold as the
temperatures later in the weekend. Lows overnight will range from
10 below zero northwest areas to 15 above zero southeast towards
northwest CT and the middle Hudson River valley. Winds will also increase
overnight across the forecast area with a wind chill warning starting
at 3 am for the southern Adirondacks...western Mohawk
Valley...eastern Catskills and southern Vermont. The jail break of
Arctic air kicks in...as the winds behind the front will be
mainly west to southwest at 10 to 20 miles per hour with gusts to 30-40 miles per hour.
Short term /6 am Saturday morning through Monday/...
wind chill warnings in effect for Saturday-Sunday morning for all
of eastern New York and adjacent western New England.
The coldest airmass of the season will be with US over the weekend
in the wake of the Arctic front as an Arctic area of high pressure
settles over the region by Sunday. 800 mb temperatures drop to 27 to 34
degrees below zero by Saturday evening. Have gone with a non-
diurnal range of temperatures on Saturday as the lows Friday night and
the highs on Saturday should be the same with the temperatures dropping
all day on Saturday. Temperatures are expected to drop from 10 below to
15 above zero early Saturday morning to 15 below zero to 5 above
zero by early Saturday evening. Wind chills on Saturday will range
from 10 below to 35 below zero with northwest winds 10 to 20 miles per hour
with gusts 30 to 40 miles per hour.
Saturday night will be especially brutal as air temperatures are
expected to drop to 5 below to near 30 below zero with wind chill
values 25 below to near 50 below zero.
Sunday into Sunday night...high pressure will move over our region
on Sunday and off the eastern Seaboard late Sunday night. Winds
will still be fairly strong on Sunday morning before subsiding
later Sunday into Sunday night. Highs on Sunday will be in the
zero to 15 above zero range with the lows Sunday night between 10
below and 5 above zero.
Monday will feature increasing clouds as the next system starts to
track northeastward from the southeast coast. Highs will moderate
on Monday ranging from the upper teens northwest to upper 20s
southeast with a chance of snow across the southern half of the forecast area
late in the day.
Long term /Monday night through Friday/...
a significant storm is expected to impact the region during the
early part of the extended period. There is increasing confidence
as to the track and intensity of this system... at least in its
early stages. Two to six inch accumulations are expected Monday
night... which is more or less the start of the event. Beyond that
there is still uncertainty as to precipitation type as there is
plenty of mild air to be drawn in out ahead of this system...thus
the exact track and intensity will be crucial. Right now...the
track is expected to be from about Charlotte North Carolina
Because the track is not seen as going far enough to the east to
give US an all snow event...indications are precipitation will
likely change over to rain for a time on Tuesday...particularly
outside of the Adirondacks...before everything tapers off as snow
Tuesday night. There is the potential for very significant
accumulations...but any decent period of rain...as is expected right
now...will keep snow accumulations at Bay.
Broad Lake enhancement on increasing westerly winds behind the
departing storm will keep snow showers of light amounts going for
many areas Tuesday night...with mixed rain and snow showers for
Wednesday. But the activity will wind down rapidly on Thursday as
high pressure settles in...but without the extreme cold we/re
expecting this weekend.
High temperatures are expected to range from the middle 30s through the
upper 40s on Tuesday...the upper 20s to around 40 degrees on
Wednesday...and the middle teens to around 30 degrees on Thursday.
Friday highs will rebound somewhat. Overnight lows Monday night
will range from the upper teens in the mountains to the upper 20s in
the Lower Middle Hudson Valley. Tuesday night...they will range from
the middle 20s in the western Adirondacks...to the lower 30s down the
Hudson Valley. Wednesday night will turn sharply colder...and
Thursday night will be coldest...with lows ranging from the low
single digits in the western Adirondacks...to the upper teens down
the middle Hudson Valley.
Aviation /03z Saturday through Wednesday/...
a clipper low will pass north of the region tonight...as the
Arctic cold front will move through overnight. A northwest flow of Arctic
air will impact the region through the day into the night period
with gusty winds.
The Arctic front will focus some isolated to scattered snow
showers or a squall from the capital region north...impacting
kgfl/kalb/kpsf between 04z-09z. The snow showers will be fairly
isolated to scattered in coverage due to very limited low-level
moisture. A vcsh was used at kalb/kpsf after 05z...and a tempo
was used for MVFR conditions at kgfl between 04z-06z.
VFR conditions will be dominate...aside for some MVFR ceilings/visibilities
with any snow showers/isolated squalls especially at kpsf/kgfl. Ceilings
will be mainly in the 4-9 kft above ground level range. In the wake of the front
late tomorrow morning...some lingering stratocumulus or middle level
clouds will linger. Overall...VFR conditions will continue in the
frigid northwest flow through the PM.
The winds will be from the south to southwest at 4-10 kts prior to
midnight...then veer to the west to northwest at 6-12 kts before daybreak
with some gusts to 20-25 kts. The winds will increase in the wake
of the Arctic front late tomorrow morning into the afternoon at
12-20 kts with some gusts around 30 kts...especially at kalb/kpsf.
Saturday night: no operational impact. No sig weather.
Sunday: moderate operational impact. Chance of snow.
Sunday night: high operational impact. Definite snow.
Washingtons birthday: high operational impact. Definite rain...sn.
Monday night: high operational impact. Likely rain...sn.
Tuesday: moderate operational impact. Chance of rain...sn.
Tuesday night: low operational impact. Slight chance of shsn.
Wednesday: no operational impact. No sig weather.
with bitter cold air in place...ice coverage on rivers and lakes
will continue to increase and strengthen over the next few days. A
few light snow showers are possible...mainly this evening...but this
will amount to little if any hydrologic significance.
However...there is the potential for a heavy precipitation event to
impact the region from Monday night through Wednesday. There
remains considerable uncertainty regarding the types of
precipitation that may occur...which will ultimately depend on the
exact track of this potential storm system. At this time...model
guidance is suggesting one to three inches of liquid equivalent
could occur...and much of this could be in the form of rain. If
this rain were to materialize...it could have a high impact on
rivers and streams...especially considering the ground will be fully
frozen by that time...allowing much of the precipitation to be runoff.
Details will become more certain over the next few days.
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.
CT...wind chill warning from 1 PM Saturday to 1 PM EST Sunday for
New York...wind chill warning from 3 am Saturday to 1 PM EST Sunday for
Wind chill warning from 1 PM Saturday to 1 PM EST Sunday for
Massachusetts...wind chill warning from 1 PM Saturday to 1 PM EST Sunday for
Vermont...wind chill warning from 3 am Saturday to 1 PM EST Sunday for