Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
1045 PM EDT Sat Sep 20 2014
a mostly cloudy and breezy night is expected overnight. A frontal
system will bring increasing chances for showers across the north
country Sunday into Sunday night. The front clears the region
overnight Sunday with unseasonably cool temperatures for Monday.
The below normal temperatures will be brief however as warmer
temperatures and dry conditions then return for much of next week.
Near term /until 7 am Sunday morning/...
as of 1045 PM EDT Saturday...current forecast in good shape...so
no changes made.
Short term /7 am Sunday morning through Monday night/...
as of 349 PM EDT Saturday...
For sunday: middle-level height falls aloft will continue to build
across the north country. Expect a rather solid line of
showers/possibly a rumble of thunder to be ongoing across St.
Lawrence Valley/Adirondacks. Cold front itself likely to make slow
eastward inroads...not bringing likely to categorical probability of precipitation into
the Champlain Valley until the afternoon hours. Though 850 temperatures
continue warming to +15c mostly cloudy skies likely to prevail.
Highs to range low-middle 70s for Vermont and only upper 60s/around 70 for
northern New York.
Sunday night: cold front finally moves through Vermont overnight.
Likely/categorical probability of precipitation early Sunday night taper to chance/likely.
Highest probability of precipitation become more closely tied to orography overnight. Strong
Post-frontal northwesterly cold air advection /850 temperatures fall to around +4 to
+7c/ contributes to low Froude numbers focusing leftover showers
to the mountains. Storm total quantitative precipitation forecast with the front ranges from
75-.8" across St. Lawrence Valley and adriondacks /much of that
falling Sun afternoon/ to a min of a tenth or so in southeast Vermont.
Expect mostly cloudy skies Sunday night with lows in the 50s
across Vermont and upper 40s across northern New York.
Monday: looks to be a cool day as thermal trough aloft gradually
builds into the north country late. Continued low-level cold air advection /850
temperatures falling below zero/ will offset any diurnal heating once
initial cloudy skies and mountain showers break. Highs look to struggle
to climb even a couple degrees from overnight lows...upper 40s/low
50s for Adirondacks/northern New York to middle/upper 50s across Vermont. Highs
some 10-13 degrees colder than climatology and northwest winds making it
feel colder than that.
Monday night: clouds continue to clear as surface ridging builds in. I
haven't put in any radiational River Valley fog but certainly
possible pending clearing. Dry with lows in the upper 30s to lower
Long term /Tuesday through Saturday/...
as of 349 PM EDT Saturday...idea of a warming and drying trend
remains on track in the extended forecast period...Tuesday through
Saturday. Large upper level ridge becomes established over the
area and moves very little...thus the reason for the dry weather.
At the same time...low level thermal profile suggests warming
temperatures each day under plenty of sunshine. Highs will be
right around seasonal normals Tuesday and Wednesday...then
readings will be 4 to 8 degrees above normal with highs Thursday
through Saturday in the middle 60s to lower 70s.
Aviation /03z Sunday through Thursday/...
through 18z Sunday...VFR ceilings and visible through the night...then
an area of rain will begin to move into the St. Lawrence Valley
after 10z. Present ceilings at or above ovc035 and area
observations and model soundings indicate this will persist
overnight until the rain moves in along/ahead of an approaching
cold front. Timed precipitation into St. Lawrence Valley/kmss 10-17z. Will be
a slow eastward progression...with a north/south oriented line
into the Champlain Valley kpbg/kbtv/krut sites after 22z. Left
precipitation out of kmpv for this forecast cycle. Ceilings and visible to drop
to MVFR with the precipitation...and improve at kmss/kslk before 00z
after the rain passes.
Outlook 00z Monday through Thursday...
00z Monday to 00z Tuesday...MVFR ceilings/visible will improve west to
east as main rain area moves east however lingering showers will
produce scattered MVFR through the day Monday.
00z Tuesday through Thursday...VFR under high pressure. Areas
IFR/LIFR in fog each morning at kslk/kmpv.
as of 315 PM Saturday...strong south winds will continue across
Lake Champlain this evening and right through Sunday with high
pressure to our east and low pressure approaching from the west.
Speeds of 20 to 30 knots are expected through Sunday morning with
gusts up to 35 knots at times. Waves will build into the 2 to
4 foot range making for rough boating conditions. Winds will
gradually weaken Sunday afternoon to 15 to 25 knots before a cold
front passes and the winds turn northwest from 10 to 20 knots later
Sunday night. As a result...a lake Wind Advisory remains in effect
for tonight and likely through Sunday. Periods of showers and even
a few thunderstorms will also affect the region Sunday afternoon
and into Sunday night.