495
FXUS61 KBTV 181936
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
336 PM EDT Sat May 18 2024

.SYNOPSIS...
High pressure will build into the region tonight and continue
through early this upcoming week. Warmer and drier weather returns
to the North Country with temperatures well into the 70s on Sunday
and upper 70s to mid 80s on Monday. Some patchy fog is possible
tonight, especially areas that received rainfall today. Building
heat will continue for Tuesday and Wednesday, along with a chance of
afternoon showers and thunderstorms.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 332 PM EDT Saturday...Water vapor showing deeper moisture
associated with weak trof shifting east of cwa, while subsidence/dry
air aloft is building over northern NY into the CPV. This drying wl
help to produce clearing skies overnight with some areas of patchy
fog. Greatest probability of fog development with vis below 1sm wl
be NEK and parts of central/eastern VT, along with portions of the
northern Dacks. The highest potential wl be from 07z-11z tonight.
Temps wl cool back into the lower 40s SLK/NEK to l/m 50s CPV/SLV.
Have noted some higher sfc dwpts pooling in the SLV, which combined
with temps dropping below cross over values and light winds could
result in some fog SLV, but confidence is too low to place in fcst
attm.

Sunday/Sunday night is very quiet with building mid/upper lvl ridge,
resulting in a dry and warm fcst. Progged 925mb temps warm btwn 15-
16C which is a few degrees warmer than today and should support
highs in the mid 70s to lower 80s. Winds wl be south at 5 to 10 mph.
Sunday night wl be warmer and less areal coverage of fog/br given a
day removed from precip and less potential for lows dropping below
cross over values. Lows generally in the mid/upper 40s to upper 50s.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 330 AM EDT Saturday...Quiet weather is expected for this period
with surface high pressure prevailing across the Northeast. With
light winds and mostly clear skies, expect overnight lows in the 50s
with a few upper 40 degree readings in the typically colder spots.
Then we begin our warming trend on Monday, with mid 570 Dm heights
nosing in from the southwest. With 925mb temperatures forecast to
reach +17 to +20C, expect daytime highs in the mid 70s to low 80s.
A few mid 80s readings are not out of the question. Light winds and
plentiful sunshine should make a rather decent day to be outdoors.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 330 AM EDT Saturday...Tuesday looks to be the warmest day of
the season with little relief overnight Tuesday. 925mb temperatures
reach +21 to +24C, or 2 standard deviations above normal. For
reference, typical highs for mid to late May are in the upper 60s to
mid 70s. Global guidance hints at the potential for some embedded
shortwave energy in the building H5 ridge east of the Ohio River
valley on Tuesday, so there remains questions how efficient the
daytime heating and boundary layer mixing can get. Adding 8C to the
forecast 925mb temperatures get us into the mid to upper 80s range,
so still quite toasty with marginal to minor heat risk concerns
since the population would not have been acclimated. If we do get
more clouds than sun on Tuesday, then overnight lows Tuesday night
might have a hard time falling below 70 here in the Champlain
valley. Additionally, there are indications the cold front could be
delayed till late Wednesday or even overnight Wednesday, allowing
for yet another day of mid to upper 80s on Wednesday. Bottom line,
it would likely be quite toasty and perhaps uncomfortably warm on
Tuesday into Wednesday so prepare accordingly.

Heading into Thursday, we do get a reprieve from the heat. While
there is a good chance for thunderstorms given the contrasting air
mass and cold front, it is far from a slam dunk we will get any kind
of severe weather. The main upper low remains over the Upper
Midwest, with pieces of weaker shortwave energy peeling off from the
parent low and giving our region a glancing blow overnight
Wednesday. This setup is not favorable for severe weather across
North Country since the best forcing is directed to our north. Given
the model differences on the timing of the cold front, have
generally kept PoPs in the chance category (less than 54 percent).
It will be a rather significant cooldown for this time of the year,
with highs on Friday into Saturday 15 to 20 degrees lower than on
Tuesday and Wednesday.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
Through 18Z Sunday...Light rain showers will exit EFK and MPV
in the next 1 to 2 hours with VFR conditions prevailing into the
evening hours. Agree with previous forecaster patchy fog is
possible (40-50%) on Sunday morning, especially at locations
that received rainfall today, such as EFK. Also, have noted
slightly higher dwpts at SLK, supporting greater potential for
going below cross over temp tonight to support some localized
fog/br. Have continued with previous forecaster idea of 1SM in
BR for now at SLK/EFK and MPV, which is supporting by model
sounding data showing a shallow thermal inversion with saturated
sfc conditions. Highest confidence of fog/br potential will be
btwn 07-11z. Elsewhere, VFR conditions persist, except a small
chance <10% of some shallow fog at MSS, however confidence too
low to mention attm. Winds are generally light and variable thru
the next 12 to 24 hours.

Outlook...

Sunday: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. Slight chance SHRA.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: VFR. Chance SHRA, Slight chance TSRA.

&&

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

&&

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