Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
721 am EDT Tuesday Sep 1 2015
the unseasonably warm and dry stretch of weather will persist across
the north country through the next 7 days...associated with the
continued presence of a mean upper level ridge across the central
and eastern United States. High temperatures through the period will
average 10 to 15 degrees above normal. No significant rainfall is
expected...but an upper level disturbance and associated surface
trough may bring a few showers and an isolated thunderstorm to the
region Wednesday night into Thursday morning.
Near term /until 8 PM this evening/...
as of 716 am EDT Tuesday...areas of fog across north country early
today. Fog will be dissipating by middle morning. Rising 700-500mb
heights continue today as a strong upper ridge builds across New
York and New England. Deep layer ridge in place will bring mostly
sunny skies and light winds...which will become south to southwest
5-10 miles per hour this afternoon. Air mass continues to warm with 850mb
temperatures climbing to around 18c this afternoon. This supports maximum
temperatures in the valleys in the middle to upper 80s...or about 10-12
degrees above normal for 1st of September. Normal high at btv
today is 76.
Short term /8 PM this evening through Thursday/...
as of 356 am EDT Tuesday...high pressure remains over the region
tonight. This will allow for mainly clear skies and light
winds...along with some patchy fog in the climatology favored areas
between 06z-12z Wednesday. Min temperatures ranging from the middle 50s in
the Adirondacks and Northeast Kingdom to the lower and middle 60s in
the Champlain and St Lawrence valleys.
Will see a temporary weakness in the mean upper ridge later
Wednesday into Thursday as a weak shortwave and associated surface
trough move southeastward from Ontario and southwest Quebec. This
disturbance will drop south across the area Wednesday night through
Thursday morning. Wednesday will be a very warm day in advance of
the weak front. 850 mb temperatures 18-20c...so look for maximum temperatures in
the valleys well into the 80s to around 90 degrees. These temperatures
combined with dewpoints in the middle 60s support MUCAPE values of
around 1500 j/kg as frontal forcing and shortwave trough approach
our international border Wednesday evening. Have continued with
20-30 probability of precipitation with mention of possible thunderstorms. Activity should
generally diminish as shortwave trough pushes southeast across our
region Wednesday night through Thursday morning. Mostly cloudy
conditions should preclude fog Wednesday night. Also...clouds
should keep min temperatures in the lower to middle 60s.
There will still be a chance for a few showers or even a
thunderstorm during Thursday as the weak front and shortwave push
south of the area. Best chance will be across southern portion of
forecast area through 18z. Morning clouds will give to increasing
sunshine from north to south during the afternoon. 850mb temperatures cool
a bit...to around 14c. Expect maximum temperatures mainly in the lower to middle
80s...with some upper 80s in the southern valleys.
Long term /Thursday night through Monday/...
as of 252 am EDT Tuesday...overall forecast for the extended
range remains unchanged as the north country will be dominated by
a large-scale upper ridge building over the eastern Continental U.S.. clear
nights and sunny days are on tap through the weekend along with
above normal temperatures. Normals for early September are highs
in the middle-70s, and lows in the low/mid-50s but with prognosticated
850-925mb temperatures of +12-20c respectively we'll be seeing a return
of more middle-Summer like values. Highs will start out
Friday/Saturday in the upper 70s to low 80s, but warm into the
middle/upper 80s for Monday and Tuesday. Lows will be near normal for
Thursday night an Friday ranging through the 50s, but warm into
the 60s for the remainder of the period. Our next chance for
precipitation at this time looks to be way out next Monday night into
Tuesday with the passage of a cold front.
Aviation /11z Tuesday through Saturday/...
through 06z Tuesday...VFR conditions and light winds will prevail
through the overnight except at kmss/kslk/kmpv where vlifr/LIFR
fog will persist/develop through 12-14z. After 14z all sites will
be VFR with just a few cirrus drifting overhead and light
Outlook 06z Tuesday through Saturday...
mainly VFR. Early morning vlifr/IFR likely at kmpv/kslk, and
possible at kmss. Slight chance thunderstorms and rain Wednesday night and Thursday.