Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
149 am EDT Mon Oct 24 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 /until 11 am this morning/...
as of 149 am EDT Monday...shortwave trough embedded in mid level
flow passing to our south with an increase in clouds through the
next few hours. These clouds along with west to west-southwest wind flow of
5-10kts keeping temperatures from dropping. Therefore, have
increased the morning lows to low 30s mainly in the Northeast
Kingdom and Adirondacks where fresh snowpack will help with
cooling. In the broad valleys, expect temperatures to remain in
Generally quiet weather expected Monday. Broad cyclonic flow
remains in place aloft, and it appears we'll have another surge of
low-level cold air advection 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 west-northwest winds 8-15kts with gusts developing in
the afternoon with presence of steeper lapse rates.
Short term /11 am this morning 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 northwest 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 Vermont 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 Vermont by 12z Fri
and moving east out of area thus wettest in ern Vermont during morning
with leftover shoer threat in upslope terrain Fri and Fri ngt.
Mildest day of stretch with highs around 50 degrees.
Thereafter...northwest flow persists but their are difference between
European model (ecmwf)/GFS with another disturbance in the flow or not. GFS..yes
while European model (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 /06z Monday through Friday/...
through 06z Tuesday...VFR conditions persist with potential for
intervals of MVFR ceilings at slk for the next few hours. Westerly
winds continue at 5-10kts til mid morning, when winds shift a
little more northwest at 8-12kts with gusts up to 25 knots during the
day. Generally VFR conditions prevail, but some low level clouds
develop in the cold air advection between 3500-5000 ft after 15z.
Chances for showers to develop increase late in the period as
embedded pieces of energy in the midlevel cyclonic flow move over
the north country.
Outlook 06z Tuesday through Friday...
06z Tuesday through 00z wednesday: VFR ceiling with possible MVFR
showers and higher elevation snow snow showers as a broad upper
trough remains over the region. Increasing chances for MVFR
ceilings at mpv/slk later Monday night through Tuesday, with
periods of light precipitation and MVFR cigs/vsby conditions.
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.