Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
137 PM EDT Wednesday Oct 7 2015
a weak cold front moves across the region later today
with a few sprinkles possible. High pressure returns tonight and
Thursday with dry weather than low pressure brings a cool rain on
Near term /until 8 PM this evening/...
as of 1054 am EDT Wednesday...no changes to previous discussion
Previous discussion as of 729 am EDT Wednesday...varying amount
of clouds and at different levels in response to approaching middle-
level shortwave and surface front. Northern stream shortwave
delivers a surface cold front across the north country this
afternoon with a few sprinkles possible. Otherwise...varying
amount of clouds and temperatures in the low- middle 60s.
Short term /8 PM this evening through Friday/...
as of 256 am EDT Wednesday...surface high pressure moves in
after passage of cold front to bring a seasonably cold night then
northern stream brings a deeper, stronger short wave and surface low
early Friday morning through Friday with decent slug of rainfall.
Tonight...it will be dry tonight with some fresh winds above the
deck that should diminish with time. Lows will be in the 30s/40s
with scattered frost.
Thursday...surface high in control with middle-level flow backing in
advance of stronger/deeper short wave will bring about increasing
clouds during the afternoon but staying dry. Maximum temperatures
slightly cooler than normal.
Thursday night...system slower than indicated yesterday thus rain doesn/T
move into northern New York to mainly after 06z and into Vermont just before
Friday...rather vigorous system moving through on Friday with decent
low-middle level jet advecting precipitable water values around 1 inch
into forecast area with rainfall amounts of 1/2-3/4 inch expected. It will
be a cool rain with high temperatures only in the 50s...some upper
40s in mountains/Canadian border and closer to 60 degrees on
south side of front near Massachusetts/Vermont border.
Long term /Friday night through Tuesday/...
as of 309 am EDT Wednesday...medium-range global models are in
good agreement for the extended period from Friday night through
Tuesday night offering mainly dry conditions through this weekend
and into early next week.
Forecast period begins Friday night where a surface cold front will
be exiting the north country to the east while high pressure builds
in from the Great Lakes. This high will center over New York/Vermont Saturday
and slide off the New England coast on Sunday with dry conditions
expected during the period. This is in contrast to previous days
model runs which were in disagreement in regards to some additional
shortwave energy encroaching from the north on Sunday. Consensus has
now come around to the European model (ecmwf) solutions which offered a stronger middle-
level ridge keeping the energy to our north and the btv County Warning Area dry. As
a result temperatures will be seasonable cool Friday night through
Saturday night with lows in the 30s and highs only in the 50s, but
as southerly return flow develops behind the exiting high temperatures will
return to more normal levels for Sunday, and above normal for Monday.
Our next chance for precipitation will come Monday night into Tuesday as
low pressure passing well to our north drags a weak frontal boundary
through the region. Above normal temperatures will continue for
Tuesday as south/southwesterly flow increases between the exiting
high and approaching front, with little quantitative precipitation forecast expected at this time as
the system lacks and real deep moisture.
Aviation /18z Wednesday through Monday/...
through 18z Thursday...surface cold front approaching the Saint
Lawrence valley has helped develop a few light rain showers along
with some additional clouds. Have mention broken in the taf sites
with periods of MVFR ceilings likely at slk through this evening. In
addition...winds will be shifting from the south/southwest to the
northwest between 18-20z today with a few gusts up to 20 knots
possible...especially mpv. Tonight taf focus will be potential for
fog and IFR conditions. Current thinking any fog/br development would
be late to occur...due to the clouds and winds between 500 and
1000 feet above ground level of 15 to 25 knots. Have mention some MVFR conditions
at mpv after 09z and IFR at slk after 08z. Used tempo to highlight
MVFR/IFR potential. VFR conditions will prevail after 12z Thursday
with northwest surface winds.
Outlook 18z Thursday through Sunday...
VFR through 06z Friday...with rain showers developing from SW to NE
across our taf sites by 12z Friday with periods of MVFR ceilings
likely...especially slk/mpv. Developing jet 3000 to 4000 feet above ground level
of 35 to 45 knots may produce some low level shear/turbulence near the
mountains on Friday. Improving conditions with southerly winds shifting
to the northwest again by 00z Saturday. VFR prevails Saturday and
Sunday with surface high pressure.