FXUS61 KBTV 221444
Area Forecast Discussion
National Weather Service Burlington VT
944 AM EST Fri Nov 22 2019
A frontal system sweeping eastward across the North Country this
morning will bring gusty winds, and temperatures briefly in the
mid to upper 40s from the Champlain Valley westward across
northern New York. Scattered showers are possible this morning,
ending as a few snow showers, especially across the higher
terrain this afternoon, as temperatures fall. Surface high
pressure brings drier conditions tonight into Saturday, with
skies Saturday becoming partly to mostly sunny, along with
seasonable temperatures. Thereafter, low pressure passing near
or south of the south coast of New England will bring a chance
of rain or snow on Sunday, with the highest chances for
precipitation across south-central Vermont.
.NEAR TERM /THROUGH SATURDAY/...
As of 944 AM EST Friday...Overall forecast in good shape with
only minor tweak being an adjustment in temperatures. Areas east
of the Green Mountains in Vermont have not mixed out yet and
temperatures are still in the mid 30s. They should start to warm
as the morning progresses and have thus adjusted trends.
Otherwise...showers moving eastward across the area as expected
with better chances in the mountains.
Surface low pressure is passing well north and west of the
North Country across swrn Quebec early this morning. However,
conditions remain dynamic across the North Country, with a warm
frontal zone lifting newd across nrn NY and VT during the pre-
dawn hours. Have seen intermittent light rain showers, and
pockets of freezing rain across eastern into nern VT, where
surface temps at 08Z remain 30-32F in some spots of the
Northeast Kingdom. Special Weather Statement and morning
Hazardous Weather Outlook continues mention of a few icy spots
possible on secondary roads and dirt roads early this AM east of
the Green Mtns. Otherwise, looking for temperatures to climb
rapidly this morning on south/southwesterly winds 10-20 mph with
a few gusts to 30 mph, and swly 850mb flow of 40-50kt crossing
our region bringing low-level WAA through 13-14Z. Based on
upstream obs, temperatures should reach the mid-upper 40s from
the Champlain Valley wwd. The cold front should cross the
region between 11AM and 2PM (around noon-1PM in the Champlain
Valley). The front will bring another period of shower activity
(amounts <0.10"), ending as snow showers across elevations above
1000` as temperatures rapidly fall this afternoon. Overall
impacts should be low, as road temperatures generally above
freezing with precipitation along the cold front. Also looking
at gusty sfc winds...especially just after the frontal passage.
Generally 30-40 mph for a couple of hours early this afternoon
after FROPA, likely highest across the St. Lawrence Valley owing
to valley channeled flow locally.
Winds gradually diminish tonight, and continued low-level CAA
contribute to overnight lows ranging from the upper teens to
lower 20s, and locally near 24F at BTV.
Saturday will be a much more tranquil day with winds returning
W-SW around 10 mph, and prospects for partly to mostly sunny
skies. Stayed near MOS consensus with highs 35-40F. PoPs NIL.
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 401 AM EST Friday...The next system to move toward the region
is late Saturday night into Sunday. Look for increasing clouds
Saturday night. Low pressure over WV is forecast to redevelop
vicinity of the Delmarva peninsula by early Sunday. Models in
general agreement that the low intensifies as it moves northeast
just north and west of the benchmark and southeast of Cape Cod
and the MA islands Sunday afternoon then south of Nova Scotia
Sunday night. This is a bit further south than was forecast
yesterday so the trend is for less impacts to our area, though
the Canadian and SREF still suggesting there is a chance of
precipitation further north and west. As is the case with most
coastal storms, the exact track will make a big difference and
is not quite nailed down yet as seen with a few model
convectively induced low pressure centers at the surface.
Thermal profiles still marginal in the boundary layer for a
rain/wet snow mix changing to snow until later Sunday as the
winds become northerly, and temperatures fall as the low moves
off to our east Sunday night. Because of the track further south
and east it looks like the heaviest precip will also be south
and east but still could impact southeast VT. Models are also
suggesting a sharp cutoff in precip to the north and west which
is where our area lies. With some uncertainty remaining keeping
30-50% PoP for rain/snow north but up to 60% or so in the
southeast near VSF. Right now QPF values range from a less than
a tenth of an inch north to about 0.40 or so at VSF. Converting
that to snow is a bit problematic with the rain snow mix but it
looks like a trace to couple inches north to 1 to 3" south
except closer to 4+ inches in the southern Greens like
Killington/Mt Ascutney where it would be mostly snow. Again
this could still change until the track becomes a bit more
certain. Any precipitation shuts down Sunday night. Highs mainly
in the 30s Sunday with lows Sunday night in the 20s..
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 401 AM EST Friday...An amplifying long wave pattern takes place
this week becoming more omega like over NA with closed lows on
each coast and a building ridge over central CONUS. As this
happens it will continue to be busy in the long term with
another intensifying low pressure system passing close to our
region midweek with rain and snow showers. The start of the work
week will feature another weak ridge of high pressure Mon into
Tue before low pressure heads our way by Wed. Models in a little
better agreement this morning with a track of the low over or
just north of our area. As such, we would be on the milder side
of the system until it passes by, so forecasting mainly rain
showers Wed changing to snow showers Wed night into
Thanksgiving. With the amplification of the ridge to our west a
north to northwest flow of cold air becomes established on the
back side of the low on Thursday with mountain snow showers and
flurries elsewhere. Temperatures look fairly close to seasonal
levels but turning a bit colder for Thanksgiving.
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
Through 12Z Saturday...Widespread MVFR conditions with HIR TRRN
OBSCD expected this morning in advance of an approaching cold
front. LLWS will be exiting to the east by 15Z this morning.
Will see periods of IFR ceilings as well, mainly at KSLK. Brief
rain showers (snow showers at KSLK) are possible as the cold front
passes through later this morning into the early afternoon
hours. Winds will shift SW and then W with the frontal passage
between 14-17Z. Should see the strongest gusts just after the
frontal passage, with gusts 25-32kt, highest at KMSS early this
afternoon. Partial clearing and a gradual lessening of winds is
expected late this afternoon and especially throughout tonight.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. Slight chance SN.
Sunday: VFR. Chance SHSN, Chance SHRA.
Sunday Night: MVFR/IFR conditions possible. Chance SHSN.
Monday: Mainly MVFR, with local IFR possible. NO SIG WX.
Monday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Tuesday: Mainly VFR, with local MVFR possible. NO SIG WX.
A Lake Wind Advisory remains in effect today. South winds 20 to
30 knots this morning will shift westerly between noon and 1 PM
with the passage of a cold front, and decrease into the 15 to 25
knot range during the mid to late afternoon hours. Waves around
3 to 5 feet will yield rather choppy conditions...especially
over the northern portion of the broad lake as winds turn
westerly with the frontal passage.