Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
627 PM EST sun Feb 1 2015
a storm system will move the Ohio River valley tonight to across
Long Island Sound on Tuesday. This system will bring increasing
clouds tonight...with moderate to heavy snowfall beginning in time
for the morning commute on Monday. Snow will continue throughout
the day Monday...tapering off late Monday evening from west to
east. Seasonably to unseasonably cold conditions will prevail for
much of the upcoming week...with any additional snowfall expected
to be minor.
Near term /until 7 am Monday morning/...
as of 530 PM EST Sunday...going forecast in good shape and no
changes to current thinking other than tweaking a few temperature
trends based on current observations. Snow on track to move in
Previous discussion...healthy looking system on water vapor and
composite radar with plenty of moisture and strong isentropic
lift formation in clouds/moisture streaming toward NY/VT.
High clouds already streaming into New York this afternoon and clouds
will continue to advance through tonight. Snowfall will arrive in
southern and western sections just after midnight...reaching
Adirondacks/central Vermont prior to morning commute and across
all of New York/Vermont around of just after morning commute.
Minimum temperatures will be somewhat tricky tonight...falling
early then rising from SW to NE as clouds and precipitation
advance... still many places at or below zero.
Short term /7 am Monday morning through Tuesday night/...
as of 304 PM EST Sunday...pretty good model agreement in all
aspects...including a further north track and greater quantitative precipitation forecast field
moving north into much of VT/NY.
Impressive dynamics and warm air advection moving across region
on Monday with deepening middle level trough still positive but trying
to go negative in progressive flow. 700 mb low moving across Vermont/New York
along with inverted surface trough.
As previous forecaster announced...areas of strong deformation
spreading into much of VT/NY...strong warm air advection aloft, combines with
strong frontogenetic forcing Monday morning into early afternoon
resulting in periods of moderate to heavy snowfall. Lift will be
enhanced/aided by small jet streak at 250mb of 100+kts moving over
the area. Precipitable waters increase to nearly double the climatological mean
for early February Monday morning into early afternoon. Expect
heaviest snowfall during this time with 1-2 inches per hour
possible across central/southern forecast area.
Snowfall amounts to range from 8-14" for Rutland and Windsor
counties in Vermont 5-10" across much of the Adirondacks/Champlain
Valley into southern Caledonia County...and then 4-7" along the
Additional warnings were issued at 1 PM as well as winter weather
It will be cold as well with highs Monday in the single numbers
and sub-zero Monday night with winds of 10 to 15 miles per hour...thus 10 to
20 below wind chills Monday and possibly 20 to 30 below wind
chills Monday night.
No headlines for wind chills but may be needed for Monday night.
Low will depart toward the Gulf of Maine...tapering off snow from
west to east...with GFS lingering snow across eastern Vermont a
little past 06z Tuesday. Ridging builds in across the south for
Tuesday during the day with another cold day in the single digits
to middle teens.
Return flow late Tuesday and westerly upper flow as it begins to
back in response to another deeper trough for late Wednesday/Thursday will
mean some lake effect snow showers Tuesday night and another
clipper system for Wednesday.
Long term /Wednesday through Sunday/...
as of 330 PM EST Sunday...active and cold weather is expected for
the extended portion of the forecast from Wednesday through
Sunday. On Wednesday a weak low pressure clipper system will be
slowly moving into our forecast area...then north and east of the
area Wednesday night. Snow showers with light accumulations are
anticipated at this time. Thursday through Friday will have a high
pressure system ridging into the north country. Friday night and
Saturday another weak low passing north of US along with
associated cold front cross the area bringing another chance for
light snow showers. Saturday night and Sunday will once again be
dry with another ridge of surface high pressure building over the
area. Wednesday and Saturday will be the warmest days of the
period...yet still a few degrees below seasonal normals.
Aviation /23z Sunday through Friday/...
through 00z Tuesday...VFR through midnight then deteriorating to
IFR visible/VFR ceilings when snow begins south to north 09-10z. After
12z visible lowers to LIFR with IFR ceilings through middle day to early
afternoon, especially krut/kmpv. Kept kmss out of LIFR category
with IFR ceilings/visible through the night. Conditions to improve out of
LIFR to IFR late in the taf period west to east.
Outlook 18z Monday through Friday...
00z-12z Tuesday...snow tapers off west to east becoming VFR.
12z Tuesday-12z Wednesday...VFR.
12z Wednesday-12z Thursday...areas MVFR in snow showers with
clipper system crossing the area.
12z Thursday-00z Saturday...VFR.
Vermont...Winter Storm Warning from 1 am Monday to 1 am EST Tuesday for
New York...Winter Storm Warning from 1 am Monday to 1 am EST Tuesday for
Winter Weather Advisory from 1 am Monday to 1 am EST Tuesday