Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
945 PM EDT sun Sep 21 2014
showers will slowly end from west to east across the region overnight.
However...some showers may linger into Monday over the higher terrain.
Monday will mark the beginning of a dry trend for the coming week as
high pressure builds over the region in the foreseeable future.
Temperatures will trend below normal for the first half of the
week...then warm to above normal next weekend.
Near term /until 8 am Monday morning/...
as of 945 PM EDT Sunday...finally starting to see some eastward
progression to the upstream upper trough...which is enhancing
precipitation in advance of it over Lake Ontario and far western
New York. The eastward progression of the trough is helping to
finally move northeast to southwest elongated area of showers
across the northern Adirondacks and Champlain Valley. This band
will continue to move eastward tonight and once the upper trough
moves east of the area very late tonight...precipitation will
become more terrain driven with the developing northwest flow
aloft. Overall forecast in good shape and just needed to tweak
current temperatures based on where precipitation has fallen
because readings are a bit cooler in these spots. No other
Short term /8 am Monday morning through Tuesday night/...
as of 405 PM EDT Sunday...westerly to northwest low level
Post-frontal flow on Monday moisture trapped around 850 mb under
the frontal inversion. Combination of upslope flow and low level
moisture will keep plenty of clouds around for much of the
day...and may continue to squeeze out some light showers in the
higher terrain. With cloud cover and cold air advection daytime
highs noticeably cooler Monday in the upper 50s/low 60s. High
pressure begins to build in Monday night...atmosphere
decouples...and radiational cooling will drop temperatures back into the
30s. Afterward...high pressure starts to make its effects felt and
temperatures moderate and clouds diminish.
Long term /Wednesday through Sunday/...
as of 330 PM EDT Sunday...long range data continues to support
the idea of an extended period of warmer and drier weather. Upper
level ridge develops over the upper Midwest early in the period
and then moves slowly toward our region by the weekend. Look for
plenty of sunshine through the period and warming temperatures.
Highs will be in the upper 60s to middle 70s by the weekend and this
will be up to 10 degrees above normal for this time of year.
Aviation /02z Monday through Friday/...
through 00z Tuesday...composite radar loop showing most of the
rain shower activity across northern New York at this time and
moving into extreme northwest Vermont as of 00z Monday. Expecting areas
of MVFR in rain showers across the region. Model guidance
continues to hint at ceilings lowering to MVFR across the region
between 06z-12z Monday and remaining mostly MVFR through 00z
Tuesday. Surface winds will be less than 10 knots overnight.
Expecting west to northwest surface wind gusts of 20 knots or
greater to develop across the region mainly from 10z-14z and
continuing through 00z Tuesday...as surface pressure gradient
tightens and the region will be under cold air advection during
the day on Monday.
Outlook 00z Tuesday through Friday...
00z Tuesday Onward...dry with building high pressure. Generally
VFR...except LIFR/vlifr nocturnal fog possible slk/mpv 06-12z each
morning Tuesday through Friday.