Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
616 PM EST sun Feb 14 2016
temperatures will remain frigid across our region through
tonight. A storm system is then expected to impact the region late
Monday into Tuesday...with the threat of a wintry mix of
precipitation changing to rain by Tuesday afternoon. Rain could be
heavy at times before ending late Tuesday.
Near term /through Monday/...
as of 615 PM EDT...Arctic high pressure /1036 hpa/ continues to
ridge in over New York and New England early this evening. The skies
remain generally clear. Temperatures continue to fall into below zero
outside the immediate capital region and in the Hudson River
valley. Otherwise temperatures are dropping off into the lower single
numbers. Some adjustments were made to the hourly T/TD/rh/apparent
The combination of clear skies...and light/calm winds will promote
excellent radiational cooling conditions...and a rapid decline in
temperatures immediately after sunset. Temperatures should continue falling
quite rapidly...before leveling off around or shortly after
midnight...and may actually rise slightly thereafter...especially
western areas...due to increasing high clouds...and a light
southeast to south wind developing.
Based on the expectation for a rapid drop in temperatures this
evening...we have undercut MOS guidance by at least 3-5 degrees
in most areas for overnight mins...with widespread min temperatures of -5
to -15 expected...except locally -15 to -20 across some more
sheltered valleys within the southern Adirondacks...the Lake
George/Saratoga region...and southern Vermont.
Monday...clouds will increase fairly quickly Monday
morning...initially high/middle level clouds...then lower clouds by
afternoon from southwest to northeast as strong isentropic lift along
the 285-295 k surfaces develops. In addition...an upper level
disturbance currently translating across the middle west will be
approaching from the southwest...albeit in a weakening/shearing
form. Light snow is expected to develop during the afternoon
hours...perhaps as early as 1-3 PM across portions of the middle
Hudson Valley/northwest CT and southeast Catskills...3-5 PM across the capital
region...central/southern Berkshires...NE Catskills and Mohawk
Valley/Saratoga regions...then 5-7 PM across the southern
Adirondacks and southern Vermont.
Snowfall accums through 7 PM EST Monday should generally remain
light...around or under an inch across the middle Hudson Valley/southeast
Catskills and northwest CT...where snow should begin earlier...and a
coating to less than an inch further north and NE...as snow will begin
Short term /Monday night through Tuesday/...
winter weather advisories and a Winter Storm Watch are in effect
from Monday afternoon into Tuesday.
Hazardous travel conditions are expected to develop Monday night
as snow overspreads the entire region. The snow will continue
through the evening hours and then transition to sleet and
freezing rain from south to north as warmer air aloft moves in
from the south. The transition will occur overnight from the
capital district...eastern Catskills and Berkshires south while it
may take until Tuesday morning for the change over to take place
for the Mohawk Valley...Lake George Saratoga region and southern
As the storm lifts northward into western/central New York during
the day Tuesday...most of any snow and/or frozen precipitation will
likely change to rain as southerly flow strengthens considerably
and transports warmer air into the region. The only exception may
be across the western Adirondacks where snow could continue well
Generally 1 to 4 inches of snow are expected across the southern
half of the forecast area with 2 to 6 inches across the northern half of the
forecast area except across the western Adirondacks where 6 to 12 inches of
accumulation is possible. In addition ice accretion will likely
range from a tenth to a quarter of an inch. Lows Monday night will
occur during the evening ranging from the upper teens northwest to
upper 20s southeast. Temperatures late Monday night will range
from the middle 20s northwest to middle 30s southeast.
During the day on Tuesday rain could be heavy at times with
temperatures rising into the upper 30s northwest to upper 40s to
around 50 southeast. Refer to the hydrologic discussion below for
any impacts on streams and rivers. Will mention the possibility of
flooding in the severe weather potential statement...especially for urban/poor drainage
Long term /Tuesday night through Sunday/...
the extended forecast period begins unsettled...but a brief period
of tranquil weather returns Thursday into early Friday...and then the next
northern stream disturbance arrives for next weekend.
Decent consensus among the deterministic and ensemble guidance that
the cyclone will pass west of eastern New York and New England into eastern Quebec
Tuesday night. Cold advection will funnel back into the region in the
wake of the storm system. Residual moisture with the middle and upper
deformation zone will transition rain back to snowfall. There
appears to be limited quantitative precipitation forecast left to utilize for substantial snow
accums...though 1 to 3 inches will be possible over the western
dacks...and an inch or two over the southern greens. Most other
locations...especially north and west of the middle Hudson Valley would
have a slushy inch or less of snowfall. Lows in the cold advection
regime would be in the middle to u20s with a few upper teens to l20s
over the western dacks.
Wednesday-Wednesday night...another short-wave moving through the base of the
h500 upper trough will approach the region from the Great Lakes
region and Ohio Valley. Falling heights and steepening lapse rates
with some low-level moisture will allow for a chance of snow showers in
most locations...except for the immediate capital region southward
into the middle Hudson Valley/northwest CT...where some rain and snow showers
are possible before the boundary layer cools. This disturbance
moves east of the forecast area Wednesday night. Light snow accums will be
possible with a coating to a few tenths of an inch...except over the
western dacks...western Mohawk Valley...and northern Catskills where an inch or
so may occur. Highs will be near normal in the u20s to m30s over the
mountains...and m30s to l40s over the valleys. Lows will be in the teens
to l20s with some single digits over northern Herkimer and northern Hamilton
Thursday-Friday PM...the middle and upper trough axis moves east of New
England. Northwest flow aloft transitions to increasing low and middle level
heights Thursday night into Friday. At the surface...high pressure builds in
from southeast Ontario and southern Quebec Thursday morning....and then drifts over
northern New England Thursday night into Friday with fair and dry weather. A warm
front associated with a cyclone moving towards the upper Midwest and
the western Great Lakes region moves towards the northeast. The warm
front approaches late in the day from the Ohio Valley and Upper Middle
Atlantic states. Clouds increase with a slight chance/low chance of snow
showers late in the day west of the Hudson River valley. Highs on
Thursday will be below normal with mainly 20s to l30s with a few teens
over the southern dacks...lows will tumble in the single digits and teens
with the anticyclone building in...and highs on Friday will rebound
close to seasonal norms with u20s to u30s.
Friday night into the weekend....the cyclone moves north and west of
upstate New York and New England Friday night. The isentropic lift ahead of
the warm front will promote a period of snow...and possibly sleet
transitioning to rain by Sat. Any snow and sleet accums look light
at this point...and it is day 6. Lows in the 20s Friday night...are
expected to rise above normal into the lower to m40s in the
valleys...and m30s to around 40f over the hills and mountains...as we get
into a warm sector briefly. The upper trough may become negatively
tilted and a cold front moves through Sat night with temperatures falling
back to middle to late Feb readings with a chance of rain to snow
showers. Improving weather to close the weekend with high pressure
ridging back in from the Ohio Valley.
Aviation /23z Sunday through Friday/...
VFR conditions are expected the next 24 hours with generally sky clear for
the first half of the taf period. As we go past 12z Monday...middle and
high clouds will begin to move into the region from south to north
ahead of our next weather system. Precipitation in the form of
snow...should hold off until after 18z/Mon.
Monday night: high operational impact. Definite snow...fzra...sleet.
Tuesday: high operational impact. Definite rain.
Tuesday night: moderate operational impact. Chance of rain showers...shsn.
Wednesday: moderate operational impact. Scattered rain showers...shsn.
Wednesday night: no operational impact. No sig weather.
Thursday: no operational impact. No sig weather.
Thursday night: no operational impact. No sig weather.
Friday: low operational impact. Slight chance of rain...sn.
ice coverage on rivers and lakes will continue to increase and
strengthen through Monday. Dry weather is expected until Monday
However...there is increasing potential for a heavy precipitation
event across the region from late Monday through Tuesday. At this
time...model guidance is suggesting one to two inches of liquid
equivalent. At least some of the precipitation could fall as
snow...sleet and/or freezing rain. As temperatures warm by Tuesday
morning...any frozen precipitation should change to rain. The rain may
become heavy at times during the day Tuesday. This could have an
impact on rivers and streams...especially considering the ground
will be fully frozen by that time...allowing much of the rain to
be runoff in areas that will not have snowpack.
With models trending warmer for Tuesday...potentially heavy rain
combined with rapid runoff could lead to some flooding of urban
and/or poor drainage locations...with isolated flash flooding
possible due to frozen ground. Will continue to monitor trends and
will mention potential for flooding in the severe weather potential statement.
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...Winter Weather Advisory from 1 PM Monday to 10 am EST Tuesday
New York...Winter Weather Advisory from 1 PM Monday to 10 am EST Tuesday
Winter Weather Advisory from 1 PM Monday to 1 PM EST Tuesday
Winter Storm Watch from Monday afternoon through Tuesday
afternoon for nyz032-033.
Massachusetts...Winter Weather Advisory from 1 PM Monday to 10 am EST Tuesday
Vermont...Winter Weather Advisory from 1 PM Monday to 1 PM EST Tuesday