Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
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FXUS61 KBTV 221421
Area Forecast Discussion
National Weather Service Burlington VT
1021 AM EDT SUN MAY 22 2016
Scattered showers will be possible this afternoon as a low
pressure system off the coast of the DelMarVa peninsula slowly
pushes northeast towards the New England coastline. Temperatures
will be near normal to end the weekend and then trend warmer by
the middle of the work week.
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --As of 1014 AM EDT Sunday...Forecast playing out pretty well. Light
rain out of mid level cloud deck is becoming more spotty, and
current POPs show a downward trend through mid day. Temperatures
are tricky with the cloud cover, and found some bias corrected
grids that captures cooler air over Lake Champlain, while warming
Northeast Kingdom into the 70s with a little clearing going on up
there at the moment. 925mb and 825mb temps support max temps in
the mid 70s, however cloud cover should keep temperatures from
realizing full potential and went a little cooler.
Left precip forecast alone with chances ramping back up in the
afternoon with some diurnal heating and destabilization.
As the low pressure system off the coast the mid Atlantic
continues to to increase in strength later today, expect the flow
aloft to turn more north east and enhance our low to mid level
moisture. Concurrently, a surface front will drop south out of
Canada and provide the forcing for scattered showers and a few
isolated thunderstorms to develop this afternoon and evening. The
chance for thunder is mostly over the Adirondacks and central
Vermont northwards as we will see some marginal instability with
surface based cape values of 200-400 J/kg and lifted indexes going
negative. The SPC SREF calibrated thunderstorm progs have been
quite consistent with the idea of 20-30% chance for thunder this
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.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
As of 237 AM EDT Sunday...Vertically stacked low pressure system
drifts east of the Delmarva peninsula during the day Monday, with
newd extending trough along the New England coast remaining in
place. It appears that overall movement/shift of this system to
the east will allow for drier air to advect into the North Country
on northerly low-level flow. As such, only included a slight
chance of showers across Rutland/Windsor counties for Monday
afternoon. Partly to mostly sunny skies (more sun north) along
with 850mb temps around +10C will yield pleasant afternoon temps
with highs 74-78F in most areas...and dewpoints dropping into the
mid-upr 40s for much of the northern 2/3rds of the region.
The vertically stacked low pressure system begins a slow northward
turn later Monday night, reaching an area east of NJ by daybreak
Tuesday. This should result in increasing mid-upr level cloud
cover across central and s-central VT during the overnight period
Monday night. Maintained just a slight chance of showers across
Orange/Windsor/Rutland Counties on nrn periphery of this system.
Increasing clouds across VT will keep lows on the mild side,
generally in the lower 50s. May see some mid-upr 40s across nrn NY
where thinner and less extensive cloud cover is forecast.
The closed 500mb low tracks nnewd across sern MA on Tuesday.
System is equivalent barotropic in nature, and likely will be
associated with bands of showers around the w/nw periphery rather
than broader zone of stratiform precipitation. Have included PoPs
40-60 percent attm, with precipitation amts 0.1-0.2" for most
sections of VT, with lighter amts across nrn NY further removed
from the low center. May see some locally heavier amts given PW
values reaching 1.2" per 00z GFS, and potential instability around
500 J/kg leading to a few embedded tstms. Some of the tstm
potential for depend on overall extent of clouds and whether or
not PBL heating/destabization can occur across the region. We will
continue to monitor. Deep layer NE flow would result in slow w-sw
storm motions if embedded convection were to develop. Highs on
Tuesday generally expected in the low to mid 70s.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 237 AM EDT Sunday...Upper low departs east of New England on
Wednesday, resulting in drier conditions and a transition toward a
warmer and more humid overall weather pattern for the bulk of the
extended forecast period. There has been an increase in run-to-run
variability in the GFS and ECMWF...making daily details a bit
uncertain. Anticipate highs Wednesday in the mid-upr 70s with just
a slight chance of a late aftn/eve shower. Building heights and
strengthening SW low-level flow should yield highs into the lower
80s for some valley locations Thursday/Friday/Saturday. Will
likely also see a gradual increase in humidity with dewpoints
getting into the lower 60s by Friday into Saturday. With air mass
becoming more moist/unstable, PoPs continue generally 30-40% each
.AVIATION /14Z Sunday THROUGH Thursday/...
Through 12Z Monday...VFR through the forecast period with broken
mid to high cloud deck currently producing light rain and drizzle
across central Vermont. The light rain currently is producing MVFR
at MPV out of a 8,000 ft ceiling. These light showers look like
they will continue to persist through the morning before a frontal
boundary brings stronger dynamics and convection with isolated
thunderstorms later in the afternoon. Best confidence in
prevailing showers remains over RUT and MPV so those are the only
locations with prevail precip however VCSH has been mentioned at
all sites but MSS. Winds generally light south to southwesterly
before turning northwesterly late in the afternoon with slight
variation per terrain/lake breeze influences.
Outlook 12Z Monday through Thursday...
06z Mon - 12z Tue: VFR/high pressure
12z Tue - 00z Thu: Mainly VFR with chance of showers in eastern
Vermont leading to brief MVFR visibility restrictions.
00z Thursday onward: VFR/high pressure.