Area Forecast Discussion
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FXUS61 KBTV 231942
Area Forecast Discussion
National Weather Service Burlington VT
342 PM EDT Sun Oct 23 2016
A departing low pressure across eastern Quebec will allow for
continued clearing this evening, along with diminishing wind
speeds. A secondary trough moving into the region from the
northwest late Monday into Monday night will bring a chance of
light rain showers, with snow showers possible across the northern
Adirondacks and northern Green Mountains. A more significant wave
of low pressure approaching from the Great Lakes and Ohio Valley
will bring the next chance for rain, generally late Thursday,
Thursday night, into early Friday.
.NEAR TERM /THROUGH MONDAY/...
As of 337 PM EDT Sunday...See summary public information statement
and local storm report for reports on snowfall yesterday through
this morning. At mid-afternoon, Lingering light
flurries/sprinkles have generally ended across the Northeast
Kingdom. Strong low- level drying underway, and has allowed for
mostly clear skies to develop from the Champlain Valley wwd...and
also across s-central VT. Should gradually see sunny breaks
develop across n-central and nern VT late this aftn. Afternoon
highs generally upr 40s to lower 50s for the Champlain/St.
Lawrence and CT river valleys. Elsewhere, steep lapse rates (and
clouds across n-central/nern VT yielding colder readings in the
low-mid 40s most locations. Gradient flow will remain moderately
strong through sunset, as 980mb sfc low across ern Quebec slowly
fills while drifting ewd north of the St. Lawrence Valley tonight.
Will keep 15-25mph with a few gusts to 35mph next 1-3 hrs, before
gradually diminishing with slow weakening of p-gradient and loss
of steep lapse rates as PBL cooling occurs toward sunset.
Generally quiet conditions tonight. A minor shortwave trough in
fast WNW flow 700-500mb layer will pass to our south across the
srn tier of NY and PA. This will yield some increase in mid-level
clouds, especially across the srn half of the forecast area. That
said, associated light pcpn should remain south of our area. West
winds continue 5-10 mph overnight, which will mitigate radiative
cooling and keep overnight lows mainly mid-upr 30s, except low 30s
in the 1-2kft elevational band.
Generally quiet weather expected Monday. Broad cyclonic flow
remains in place aloft, and it appears we`ll have another surge of
low-level CAA and possible passage of weak mid-level shortwave
trough. Shallow instability layer will produce clouds by afternoon
and possible light upslope precipitation into the Adirondacks and
nrn Green mtns. Freezing levels generally 2000-2500ft, so can`t
rule out some flurries down to about 1000ft in elevation Monday
aftn, especially wrn slopes. May see passing sprinkles in the
valley locations, and kept PoPs generally less than 20%. High
temps generally low-mid 40s, except upr 40s near Lake Champlain
and with downslope warning effects across ern Windsor county/VSF
area. Winds will be W-NW winds 8-15kts with gusts developing in
the afternoon with presence of steeper lapse rates.
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 302 PM EDT Sunday...Cold, cyclonic flow continues across area
with still a few spokes of energy flowing across northern areas
for fall/winter like chance of mtn sprinkles/flurries during this
period. The influence of this trof weakens Wed. It will be
unseasonably cold with highs in the 30s/40s and lows in the 20s.
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 302 PM EDT Sunday...Trof axis sliding east on Wednesday with
lessening influence and some shortwave ridging going into Wed ngt
before another shortwave in overall NW flow pattern impacts our
region late Thu thru Fri.
Slowly increasing sunshine on Wed but cold with Highs only in
30s/40s with high pressure Wed ngt for a chilly one with lows in
teens/20s. Morning sunshine will try to offset chilly temperatures
with clouds advancing with the next system previously advertised.
Precipitation shouldn`t threaten western zones until 18z or later
and VT aft 21z Thu. Ptype should be mainly liquid with some mixed
rain/snow in highest elevations. Highs in the 40s.
Surface low and accompanying front should be across VT by 12z Fri
and moving east out of area thus wettest in ern VT during morning
with leftover shoer threat in upslope terrain Fri and Fri ngt.
Mildest day of stretch with highs around 50 degrees.
Thereafter...NW flow persists but their are difference between
ECMWF/GFS with another disturbance in the flow or not. GFS..Yes
while ECMWF does not. WPC has this feature...cold front as well as
our Superblend ensemble thus will go for chance of showers Sat and
dry for Sun although confidence is lower in this timeframe.
.AVIATION /20Z Sunday THROUGH Friday/...
Through 18z Monday...Conditions have improved to VFR all TAF
locations with strong sfc low departing across ern Quebec north of
the St. Lawrence Seaway. Main issue will be continued gusty W-WNW
winds through 00Z, generally sustained 10-20kts with gusts to
25kts. Winds will diminish to 5-10kt after sunset. Minor upr
trough passing to our south will bring increasing mid-level clouds
overnight, though should remain VFR. Outside chance of MVFR at
KSLK 06-12Z Monday with upslope flow conditions, but kept current
TAF VFR. WNW winds generally 8-15kts after 14Z Monday.
Outlook 18z Monday through Friday...
18z Monday through 00z Wednesday: Broad upper trough in place
bringing variable cloudiness. Generally VFR ceilings, with
possible MVFR showers and higher elevation snow showers late
Monday afternoon through Tuesday vcnty of the nrn Mts. Increasing
chances for MVFR ceilings at MPV/SLK later Monday night through
Tuesday, with periods of light precipitation and MVFR cigs/vsby
00Z Wednesday through 00Z Saturday: Next low pressure system
approaching from the Great Lakes/Ohio Valley brings chances for
widespread showers and periods of MVFR conditions late Thursday
through the first half of Friday.
AS OF 435 AM EDT Sunday...Lake Wind Advisory continues for Lake
Strong west to northwest winds of 20 to 30 knots continue across
Lake Champlain this afternoon. This will result in wave heights
of 3 to 5 feet. The highest waves will be along eastern shores
exposed to a greater fetch on west winds; specifically those
locations adjacent to the open waters north of the Charlotte Ferry
and south of Valcour Island. Look for winds to drop considerably
down to 5 to 15 knots later this evening and bring an end to