Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
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FXUS61 KBTV 181830
Area Forecast Discussion
National Weather Service Burlington VT
230 PM EDT Tue Oct 18 2016
A warm front will lift north of the area today with unseasonably
warm temperatures expected. A weak cold front with scattered showers
will cross the area this evening and tonight. Mild and increasingly
unsettled weather is expected across the area by Thursday into
Friday, followed by much cooler, showery weather next weekend.
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
-- Changed Discussion --As of 220 PM EDT Tuesday...Complex hourly surface temperatures
across our region this afternoon as warm front pushes from
southwest to northeast. The biggest challenge has been the marine
layer over eastern Vermont which is leading to nearly a 30 degree
temperature fluctuation from Massena NY to Springfield VT.
Guidance is struggling to put it nicely with this low clouds
although with the last couple of visible satellite scans there is
some evidence of the clouds beginning to erode. If we break out
for even an hour or so temps will jump up by 5-10 degrees. However
I`m not sure we will so I`ve trended eastern and southern
Vermont`s temperatures down quite a bit.
Expecting gusty south/southwest winds to continue this
afternoon...with bottom of the mixed layer off RAP13 sounding
supporting gusts between 45 and 50 mph. Wind advisory looks good
for the Saint Lawrence Valley with the strongest winds occurring
between 1 PM and 5 PM. Several record high temps will be
approached this afternoon...especially at MSS. Any rain associated
with surface boundary arrives in the western cwa around sunset.
An interesting day weatherwise across our area as a strong warm
front lifts northeast through the area with very warm temperatures
expected in many locales. Other than a scattered showers/isolated
storms far north and east this morning, much of the day should
trend very mild and dry as skies trend partly sunny in all but far
northeastern counties. 24-hour back trajectory analysis at 21Z
suggests source air arrives from southern Ohio in the Champlain
Valley, and from near the KY/TN border across our northern NY
counties. Values in these areas were in the lower to mid-80s
yesterday, so readings in the upper 70s to lower 80s seem quite
plausible from the Champlain Valley west this afternoon. Further
east and north, the warm front will begin to slow as it encounters
a more stubborn maritime airmass across eastern New England. In
these northeastern counties clouds will likely linger a good
portion of the day and keep resultant temperatures somewhat cooler
(upper 60s to lower 70s). These values are still some 10 to 15
degrees above normal however.
In addition to the mild temperatures, south/southwesterly winds will
trend quite breezy to windy from the Champlain Valley west by this
afternoon. Indeed, gusts into the 25-35 mph range will be likely in
the Champlain Valley and Adirondacks with channeled flow boosting
gusts into the 40-50 mph range in the SLV where a Wind Advisory is
in effect from noon to 800 pm local time. By later this
afternoon/early evening a weak cold front will approach from the
northwest with scattered shower activity developing along an
associated pre-frontal trough across northern NY counties. Given
some nominal boundary layer instability and latest 3-hrly SREF/MOS t-
progs have offered an outside shot of an isolated storm or two in
these areas as well.
Front then sinks through the area tonight with scattered
showers/isolated storms as winds abate fairly quickly. Precipitation
coverage should wane in coverage after midnight as front clears
south. Larger-scale background flow remains deep southwesterly
across and behind the boundary however, so an appreciable airmass
change is not expected with lows generally holding on the mild side
in the 50s to around 60.
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.SHORT TERM /11 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
As of 415 AM EDT Tuesday...Cold front continues to depart to the
east with the North Country. Westerly flow with cooler
temperatures and dry conditions prevail for Wednesday and
Wednesday night with brief period of surface high pressure over
the region. Temperatures will remain above normal with maxes in
the 60s and mins in the 40s. Clouds increase Wednesday night ahead
of approaching low pressure system.
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 502 AM EDT Tuesday...Pattern changes with potential long
duration rain event. Mid-upper level trough will dig south and
east from south central Canada, towards the Mississippi into the
southern Ohio Valley late Thursday. At the surface, a low pressure
system will gradually strengthen and bring a warm front into the
North Country late Thursday. This low track up to Ohio River
valley, continuing NEwd over PA by Friday morning. GFS and NAM
depict strong area of frontogenetic forcing over portions of the
North Country Friday. Mid level trough becomes negatively tilted
late Friday as it interacts with coastal low followed by rapid
strengthening of the surface low come Saturday morning. As the the
surface low moves east into Maine, cold air filters in on NW flow.
540 thickness line moves into the area, indicating possibility for
some snow showers Saturday morning, mainly in the higher
elevations. Rain continues with possible breaks as dry slot may
develop on Saturday. The low becomes closed and stacked during the
day, with several pieces of vorticity embedded in cyclonic flow
keeping a chance for precipitation through at least Sunday. Storm
total QPF may vary widely based on where deformation zone develops
.AVIATION /19Z Tuesday THROUGH Sunday/...
-- Changed Discussion --...Strong/gusty winds expected at KMSS today...
Through 18Z Wednesday...Largest concern is remains the gusty
south/southwesterly winds and enhanced low level turbulence
this afternoon/early evening. Mean boundary layer flow of
20-30kts will continue for KRUT/KBTV/KPBG/KSLK with surface gusts
for 25 to 35kts at least through 22-00z. At MSS expect Stronger
gusts in the 35 to 50 mph range as a low level jet peaks over the
Saint Lawrence Valley. These winds will create moderate low level
turbulence though directions are within climatological norms so no
large- scale crosswind concerns are expected. A cold front with
showers will arrive later today/tonight skies will trend BKN/OVC
in the 040-090 AGL range, trending MVFR at KSLK/KMPV for a short
period. Winds to generally abate after 00Z, veering to
west/northwesterly behind the front after 06Z.
Outlook 18Z Wednesday through Sunday...
18z Wednesday - 12z Thursday: VFR under weak high pressure.
12z Thursday through Saturday: Trending MVFR/IFR by 00Z Friday as
frontal zone and developing low pressure bring widespread
showers/rainfall to the area.
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A warm front lifting northward across the area this morning will
allow increasingly strong southerly flow to develop on Lake
Champlain by late morning into the afternoon hours. Sustained
winds of 20 to 30 kts are expected with gusts to near 35 kts. This
will create choppy to rough conditions on open waters and in
bays/inlets with open southerly exposures. These conditions may
pose a hazard to small craft and inexperienced mariners. A cold
front will cross the area tonight with scattered showers as winds
abate and veer to west/northwesterly over time.
Max Temp Records for 10/18/2016
NY...Wind Advisory until 8 PM EDT this evening for NYZ026-027-087.