188
FXUS61 KBTV 060229
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1029 PM EDT Sat Oct 5 2024

.SYNOPSIS...
After a beautiful day temperatures will quickly cool off tonight
with areas of patchy fog developing after midnight. Lows will range
from the upper 20s to lower 40s across the region with some patchy
frost possible in the colder valley locations away from Lake
Champlain. Another mild and dry day is anticipated on Sunday, before
a cold front produces scattered showers Sunday evening into Monday.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 1022 PM EDT Saturday...Temperatures have been cooling down
rapidly this evening. Many areas have already dropped more than
20 degrees and temperatures will continue to steadily fall. Some
clouds over Quebec`s Eastern Townships are attempting to drop
into the Northeast Kingdom, and skies could turn partially
cloudy there as the night goes on. Fog is just beginning to
form in a few of the climatologically favored areas and it will
become more widespread as the night progresses.

Previous Forecast...Fcst focus tonight wl be frost and fog
potential acrs parts of our cwa. Water vapor shows a lobe of
extremely dry air aloft advecting acrs our cwa, while 1028mb sfc
high pres builds into our fa. This dry air aloft wl result in clear
skies tonight with temps quickly dropping after sunset due to light
winds and dwpts in the 30s. These ideal radiational cooling
conditions wl result in the coolest temps of this fall season acrs
many locations with lows in the upper 20s to lower 40s. Have
followed previous fcster lead and trended toward the 10th NBM for
lows with some blending of the latest MAV. This supports near 27F at
SLK to 43F here at BTV. Areas of patchy frost is likely acrs the
dacks/nek, but our frost program has ended. Also, some patchy frost
in a few selected valleys of Washington/Lamoille and Orange Counties
is possible tonight, along with localized valleys of eastern
Chittenden and Franklin counties, but coverage and duration is not
enough for an advisory attm. Have fog in the favored climo valleys,
but delayed development until after midnight. Sounding data also
supports fog at EFK too, due to lingering llvl moisture and
sharp/shallow inversion.

After a chilly start on Sunday morning, temps wl quickly warm with
developing southerly flow ahead of our next cold frnt. GOES-16 vis
satl upstream imagery shows some mid lvl clouds associated with weak
warm frnt type over the western Great Lakes, while ribbon of deeper
moisture with boundary is over the northern Plains. This moisture
and dynamics wl be approaching our western cwa by 00z Monday with
increasing clouds and showers developing. Have utilized a
combination of NAM3KM and 12z HRRR composite reflectivity progs for
timing of precip moving from west to east acrs our cwa on Sunday
night. Also, have bumped winds up aft 18z on Sunday, as soundings
support some mixing of winds of 20 to 25 knots with potential
localized higher gusts overnight Sunday with frontal boundary.
Finally noted a weak axis of elevated instability with boundary on
Sunday evening, so a rumble or two of thunder is possible,
especially given the robust dynamics and associated synoptic scale
height falls. Highs on Sunday warm into the mid 60s to lower 70s
with lows Sunday night in the mid 40s to mid 50s.

&&

.SHORT TERM /MONDAY NIGHT/...
As of 317 PM EDT Saturday...Additional rain showers are expected
through the first half of Monday with a strong cold front continuing
to work across the North Country. Additional rainfall amounts during
the daylight hours will be less than two tenths of an inch across
eastern Vermont with little to northing across western Vermont and
northern New York. Dry air is expected to filter into the region
rapidly following the frontal passage which will likely aid in
bringing gusty northwesterly winds to the area. Very inefficient
heating is expected on Monday giving strong cold air advection in
the low to mid-levels with highs only topping out in the mid 50s to
mid 60s. As dry air continues to filter into the region overnight
Monday, temperatures are expected to drop to some of the coolest
values seen this fall with lows dropping into the upper 20s in the
typical cold hollows to mid 40s in the wider valleys. Fog isn`t
expected Monday night as enough low level flow should dampen the
possibility of fog settling into the valleys.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 317 PM EDT Saturday...We`ve got an exceptional week of weather
on tap, especially for those visiting to see the fall foliage.
Temperatures through the week are expected to be at or just above
seasonal normals for afternoon highs and at to just below normal for
morning lows. A reinforcing shot of cold air is expected to descend
out of Canada on Wednesday which could bring a few showers to the
region but the lack of any appreciable moisture should keep the
shower activity rather isolated. On a more interesting note, the
global models continue to show increased confidence in the potential
for a few mountain snow showers Wednesday evening and Thursday
morning. Both 850 mb and 925 temperatures are expected to be below 0
degrees C but the lack of moisture will be the huge question mark.
However, northwesterly upslope snow is always favorable, especially
near Jay Peak, to help squeeze out a few flurries. Accumulations
will be minor, if any, with afternoon temperatures on Thursday well
above freezing. Still, it`s a sign that seasons are changing. High
pressure will build back into the region Friday into Saturday with
warming temperatures expected as we head into next weekend.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...The primary forecast challenge continues to
be whether or not fog will be able to form in climatologically
favored ares given the day`s drier dew point temperatures.
Crossover temperatures are rather low, in the 30s and lower 40s,
across the North Country. However, light winds, and clear skies
will help with radiational cooling. Therefore, the previous TAFs
were largely maintained with the main change that onset of
mist/fog was delayed an hour at SLK/MPV by an hour given the
temperature trends. Best chances for IFR remains at SLK/MPV/EFK
between 07-12Z. Otherwise, calm or light drainage winds are
anticipated overnight before the pressure gradient tightens
after 15Z with southerly responding terminals like PBG/BTV see
some winds gusting around 20kts; elsewhere winds will be
lighter with gusts to around 15kts.

Outlook...

Sunday Night: Mainly VFR, with local IFR possible. Definite SHRA.
Monday: Mainly VFR, with areas MVFR possible. Chance SHRA.
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Slight chance SHRA.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: VFR. Chance SHRA.
Wednesday Night: Mainly VFR, with areas MVFR possible. Slight
chance SHRA.
Thursday: Mainly MVFR, with local IFR possible. Slight chance
SHRA.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Taber
NEAR TERM...Myskowski/Taber
SHORT TERM...Clay
LONG TERM...Clay
AVIATION...Boyd/Taber