909
FXUS61 KBTV 300747
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
347 AM EDT Mon Sep 30 2024

.SYNOPSIS...
Widespread areas of dense fog and low clouds will slowly burn off
between 9 AM and noon today. Similar to yesterday high temperatures
will be in the 70s with mostly sunny skies by this afternoon.
Slightly cooler conditions are expected on Tuesday with dry
conditions prevailing. Our next chance of scattered showers arrives
on Wednesday, along with temperatures closer to normal.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 346 AM EDT Monday...Crnt GOES-16 Night Fog satl imagery is
showing widespread fog and low level stratus acrs our entire cwa
this morning. BTV has been down to 1/2sm in fog at times. Interesting
to watch trends of stratus/fog developing acrs the CPV
associated with low level easterly drainage down the
Winooski/Lamoille and Otter Creek River Valleys. Meanwhile,
northerly 925mb flow of 20 to 25 knots is present on the CXX VAD
helping with convergence and development of areas of stratus
under strongly block flow in other parts of the CPV. Given the
widespread development of fog with vis below 1/2sm at times our
plan wl be to issue a SPS to highlight hazard during morning
commute. Otherwise, given the widespread development and
weakening 925mb flow per soundings, expect the fog/low stratus
to slowly burn off btwn 14-16z, especially deeper valley
locations. This wl delay rate of warming during the morning
hours, but given similar 925mb temps this aftn to yesterday,
thinking highs low to mid 70s wl occur.

Tonight, conditions are slightly different from this morning, as
soundings are showing stronger 975mb to 925mb winds of 20 to 30
knots and less of an inversion, especially acrs the CPV and SLV.
Crnt thinking is areal coverage of fog/br wl be mostly confined to
climo favored areas of eastern VT and Dacks, but if winds just off
the deck are lighter than progged, widespread fog is possible again.
Also, associated with north/northeast flow is modest llvl caa with
925mb temps 1 to 3 degrees cooler tonight and bl dwpts are slightly
lower too. Lows generally in the mid 40s SLK/NEK to mid/upper 50s
near Lake Champlain. By Tues 925mb to 850mb flow turns to the
east/southeast and slightly cooler temps are progged to advect into
our cwa, especially eastern/central VT. Soundings are very dry, but
would not be surprised to see some clouds develop along the
favorable se upslope regions of the central/southern Greens on Tues.
Based on progged 925mb temps btwn 10C CT River Valley to 14C SLV
have temps from the mid/upper 60s east to mid 70s SLV.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
As of 346 AM EDT Monday...A weakening cold front passes through on
Wednesday, bringing a line of showers. The precipitation amounts
will be relatively light as the forcing will be weak and it will be
moving quickly. The best dynamics will be to the north so those
areas will likely see the most precipitation. A combination of the
weakening front and downsloping could leave southeastern areas
completely dry. Currently expecting totals up to around 0.15 inches.
The front will not cause much of an airmass change, but the clouds
and showers will keep temperatures on Wednesday a little cooler than
on previous days. Highs should be in the 60s for most places.
Boundary layer wind and clouds look to prevent any fog from forming
Tuesday night. A southerly low-level jet will cause channeled flow
in the Champlain Valley and some downslope winds across the northern
Adirondacks, where gusts above 20 mph are possible for a period of
time on Wednesday.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 346 AM EDT Monday...A relatively progressive pattern will
persist through this period, with two frontal passages and areas of
high pressure in between. Relatively zonal flow looks to dominate as
well, so there are no significant storm systems expected. The first
front looks to pass through Friday night into Saturday. There is
still high model spread so went with chance PoPs for now. For
example, the Euro beings it though virtually dry, the GFS develops a
low along it and brings widespread rain, and the ensembles are all
over the place. Regardless of the solution, significant rainfall is
not expected as only one ensemble has more than 1 inch in 24 hours.
The nest front looks to approach on Monday, but the rain associated
with it should be relatively light again. The airmasses on the
backsides of each subsequent front look to be a little colder, but
with climatological normals decreasing relatively quickly this time
of year, temperatures look to remain slightly above average.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
Through 06Z Tuesday...High confidence near 100% of VLIFR at
MPV/SLK in fog with vis 1/4sm and cigs overcast at 100-200 feet
prevails thru 12z. Slightly lower confidence in the 80-90%
range IFR/VLIFR continues at EFK thru 12z. Expecting variable
continues to jump between LIFR and MVFR conditions to prevail at
PBG/MSS thru 12z, while VFR occurs at BTV/RUT. However, with
light drainage developing and fog bank already east of runway at
BTV, thinking a period of IFR is possible 30-40% btwn 09-12z
this morning, so have tempo that idea. Also, a similar scenario
is possible (20-30%) at RUT toward sunrise. Given the light
flow and sharp inversion, mixing will be delayed again on Monday
morning, so vis/cigs slowly improve to VFR conditions at all
sites btwn 13-15Z, latest at MPV/SLK. Light mainly terrain
driven winds prevail thru the next 6 to 12 hours.

Outlook...

Monday Night: VFR. Patchy BR.
Tuesday: VFR. Patchy BR.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: Mainly MVFR, with areas VFR possible. Chance SHRA.
Wednesday Night: Mainly VFR, with areas MVFR possible. Slight
chance SHRA.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.

&&

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

&&

$$
SYNOPSIS...Taber
NEAR TERM...Taber
SHORT TERM...Myskowski
LONG TERM...Myskowski
AVIATION...Taber