539
FXUS61 KBTV 182355
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
755 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 750 PM EDT Saturday...No major changes were made to the
forecast with only some patchy fog added to the vicinity of
Newport, VT where rainfall occurred earlier. Skies are expected
to clear more overnight in northern Vermont with saturated
surface conditions expected by 3AM for areas that received rain.
Otherwise, unseasonably warm conditions are expected tomorrow
and will continue at least through Wednesday.

Previous Discussion...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 342 PM EDT Saturday...Our warming trend continues on Monday.
Mostly likely high temperatures appear to range from 80 to 84 for
most locations with abundant dry air in the 700 millibar level and
above sliding through on westerly/northwesterly flow. There may be
scattered cumulus with moderately high 850 millibar moisture. As
surface based instability grows with daytime heating, sufficient
orographic lift should support spot showers and maybe a
thunderstorm, especially in the Adirondacks where a chance of
showers is indicated. Dry air entrainment and poor mid-level lapse
rates do limit the potential of thunderstorms. Very little spatial
coverage is expected if anything can fire due to lack of upper level
forcing or a surface boundary in the region. Monday night there will
be some increasing chances of showers towards daybreak associated
with a vigorous shortwave approaching from the central Great
Lakes. There are large timing differences with this system,
however, as it slides across the upper level ridge in our
region, so this part of the forecast is very uncertain at this
time. Modest southerly flow will keep temperature rather mild in
the upper 50s to low 60s in most locations.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 342 PM EDT Saturday...A pretty active weather pattern
looks to develop, especially midweek. A mix of both heat and
thunderstorm potential exists for multiple days, especially
Tuesday and Wednesday. While a heat advisory may not be issued,
both the WBGT and experimental HeatRisk have continued to trend
higher, well into the moderate range, such that I expect heat
impacts will occur in our region. Compared to the previous
forecast, Tuesday has trended slightly less hot due to the
potential for thunderstorms during the daytime, while Wednesday
is now looking like the warmest day of the week with highs in
the upper 80s in most valley locations.

Tuesday is a sneaky severe thunderstorm day as the
aforementioned shortwave Monday night could provide very good
support for widespread convection if we see heat build ahead of
the upper level forcing. Otherwise, the best largest scale
severe weather potential is still indicated for Thursday.
However, looking at cluster analysis for the overlap of shear
and CAPE, global models are split. Out of the four most likely
scenarios, two suggest the cold front moves through too early in
the day to support severe weather, one scenario shows best
ingredients to our south, and one does favor our forecast area.
Behind the expected cold frontal passage, temperatures look to
return to near normal for the later part of the week.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...All terminals are currently VFR and they stay
that way through the evening. Patchy fog will develop across the
region later tonight. Fog is most likely at SLK and EFK while it is
possible but less likely at MPV and MSS. Any fog would quickly
dissipate once the sun rises, though it may leave MPV quicker if a
lower cloud deck can arrive before sunrise. Regardless of what fog
forms, ceilings at MPV should lower to MVFR later in the night. This
cloud deck should scatter by mid-morning and VFR conditions will
return. Any other low ceilings would be explicitly due to fog. Once
conditions become VFR tomorrow, they will remain that way for the
rest of the day. Winds will generally be relatively light and
southerly during this period. Lake breezes could cause winds to
become more westerly tomorrow at BTV and more easterly at PBG.

Outlook...

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

&&

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

&&

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