FXUS61 KBTV 141901
Area Forecast Discussion
National Weather Service Burlington VT
301 PM EDT Mon Aug 14 2017
Weak high pressure will keep the North Country dry this
afternoon and through the evening. Southwest flow aloft will
spread clouds into the region bringing deeper moisture to the
North Country during the overnight hours. As a low pressure
system digs to our north we`ll see enhanced shower activity with
scattered showers and thunderstorms during the afternoon hours
Tuesday. The cold front moves through late Tuesday into
Wednesday morning ushering in much cooler temperatures for
Wednesday and Wednesday night. Our next chance of showers
returns towards the end of the week with as another system will
bring widespread rain to the North Country heading into the
.NEAR TERM /THROUGH TUESDAY NIGHT/...
As of 253 PM EDT Monday...This afternoon should finish just at
quietly as it starting. The high pressure continues to dominate
the North Country and dry air in the mid levels is evident on
the WV satellite and from the Maniwaki and Albany 12z soundings
this morning. We should end up peaking in the low to mid 80s
this afternoon under partly to mostly cloudy skies. Overnight I
stayed away from the idea of any fog forming as we are another
day removed from the moisture source and the boundary layer
winds shouldn`t decouple as much as light night. BufKit
soundings at both Montpelier and Saranac show boundary layer
winds of 10-15kts roughly 200 feet off the deck which should
preclude much in the way of fog development. However as we
cool under the high pressure some lower stratus clouds may
develop which again should aid in preventing fog development.
Lows overnight will fall into the mid 50s to low 60s in the
The forecast challenge in the near term is what happens on
Tuesday. Energy from a vort will lift through the Adirondacks
during the overnight hours early Tuesday morning and with
orographic lift should be enough to cause some showers to move
up through the Adirondacks and into the Northeast Kingdom.
During the morning hours, warm air advection and diurnal heating
should warm the North Country to the low 80s. Those temps
combined with dewpoints increasing to the upper 50s to low 60s
should mean there will be plenty of instability to initiate some
storms. NCAR ensembles show quite a bit of scattered 40dbz
composite reflectivity values but no distinct locations. The
best downdraft CAPE is well to our south with the best signal
over the Mohawk valley and along the MA/VT border. We will be
right in the nose of the right rear quadrant of a robust 250mb
jet so there will be ample divergence aloft for any of the
storms that do develop. As such, I`ve followed the lead of SPC`s
marginal risk and included the mention of gusty winds for the
forecast area during the afternoon hours Tuesday. I dont
anticipate any widespread severe activity but rather a storm or
two that could become storm and produce strong winds.
The front then clears through the North Country overnight and
we see a return of northwest flow aloft and cold air advection
although we shouldn`t cool much more than Monday night as our
lows will be in the mid to upper 50s.
.SHORT TERM /WEDNESDAY/...
As of 309 AM EDT Monday...Upper trough moves into the Canadian
Maritimes and this will put our area in northwest flow aloft.
Any precipitation should come to an end Tuesday night with drier
air moving in for Wednesday. Looking at a cold air advection
pattern too and with cooler 925/850 millibar temperatures...look
for highs only in the 70s on Wednesday with somewhat gusty
Quiet weather returns on Wednesday as high pressure returns.
With the southerly flow Tuesday, temps will warm to the upper
70s to low 80s and then as the upper level trough clears, light
cold air advection will begin. Expect lows overnight will fall
into the mid 50s with low to mid 70s expected Wednesday
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 309 AM EDT Monday...Medium and Long range guidance is all
over the place for late week and next weekend, thus confidence
is low for the later periods.
General agreement of Surface High across area Wed ngt as cold front
is south of fa. Then the differences begin with GFS/Canadian and WPC
agreeing on more amplitude ridge to delay any precipitation til Thu
ngt whereas ECMWF quickly dampens flow for pcpn arriving by midday
Thu. Will go with majority here. The exit strategy of pcpn is in
question as all the models mentioned above have totally different
solutions. Canadian/GFS keeps shower threat on Sat but for total
different reasons. In fact, by 00z Sun, ECMWF and Canadian are more
in line with differences in strength of shortwave trof moving
through Sat ngt them some rising heights and minor ridging for
Again, greatest confidence of shra threat Thu Ngt and part of
Fri. Thereafter, minimal CHC pops through the period. Seasonable
temps although a tad on the chilly side Thu morning with some
30s in coldest valleys possible.
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
Through 12Z Tuesday...VFR condtions generally expected to
prevail through the TAF period with a few breaks of MVFR as low
stratus may develop just before sunrise in the mountain taf
sites. Winds will generally be southerly and should remain less
than 10kts. Light showers are anticipated at SLK and MPV during
the overnight hours and then becoming more robust during the the
afternoon hours. These thunderstorms will be scattered in
nature so for the moment I`ve opted to leave mention out
because of confidence in a storm hitting any individual TAF
Tuesday Night: VFR. Slight Chance SHRA.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Chance SHRA.
Thursday Night: VFR. Chance SHRA.
Friday: VFR/MVFR. Chance SHRA.
Friday Night: VFR. Chance SHRA.
Saturday: VFR. Chance SHRA.