-- Discussion containing changed information from previous version are highlighted. --
933
FXUS61 KBTV 102341
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
741 PM EDT Mon Jun 10 2024

.SYNOPSIS...
Plenty of clouds will prevail overnight with areas of patchy drizzle
and fog, especially across the higher terrain. Temperatures will
slowly cool back into the 40s to mid 50s. Tuesday will feature a few
more breaks in the cloud cover with temperatures warming back into
the mid 60s to mid 70s. A few widely scattered showers are possible
on Wednesday, especially eastern Vermont, before a brief dry spell
with warmer temperatures return for Thursday.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
As of 344 PM EDT Monday...Upper air analysis shows closed cyclonic
circulation is located over northern Maine this aftn with mid/upper
lvl trof axis extending back into northern NY. Plenty of clouds are
anticipated overnight associated with moist/cyclonic upslope flow as
moisture is trapped below developing subsidence inversion. Given
sounding profiles and webcams today, anticipate areas of fog/patchy
drizzle is likely above 1500 feet tonight, especially
northern/central Greens and northern Dacks. As subsidence layer
continues to push toward the sfc, expect low cigs to produce areas
of fog especially mtn valleys by early Tues morning. Temps remain
mostly steady in the mid 40s to mid 50s acrs our cwa with light trrn
driven winds. Tuesday mid/upper lvl trof axis prevails with slightly
less deep layer moisture overhead. Expecting northwest downslope
regions of the western CPV and lower CT River Valley near VSF to see
increasing amounts of sunshine, along with parts of the SLV. Areas
that see some breaks in the overcast should warm back into the l/m
70s, while mtn towns hold in the upper 50s to mid 60s. A spot light
shower or pocket of drizzle is still possible, but overall
probability of measurable precip is <15% on Tues. Tue night is dry
with no impactful wx anticipated. If areas of clearing develop,
especially mtn valleys patchy fog is possible as temps reach cross
over values, but probability attm is <20% and confidence in this
scenario is low. Lows generally in the l/m 40s to mid 50s again with
light trrn driven winds.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 344 PM EDT Monday...One last day under the influence of a
decaying upper level low will support at least some shower chances,
especially in the eastern half of Vermont. Forecast soundings show
meager instability focused below the hail growth zone, so it will be
hard to see any thunderstorm development. Temperatures should tick
up a few degrees from Tuesday, especially if we wind up being partly
to mostly sunny. That being said, forecast highs have trended
downward a hair compared to the previous forecast, with highs
ranging through the 70s. Overnight precipitation chances drop to nil
as ridging starts to nudge in from the west. With light winds, there
could be patchy fog where it rains during the afternoon/early
evening hours but overall very quiet weather is expected with
seasonable temperatures.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 344 PM EDT Monday...Thursday looks seasonably warm and dry with
weak upper level ridging. Temperatures should climb into the low to
mid 80s for most locations and based on low spread in high
temperatures from NBM guidance, this is a high confidence forecast.
With low level flow turning from westerly to southwesterly, there
should be a modest increase in humidity but overall due to
relatively dry air upstream, dew points should still remain in the
50s. With mid and upper level westerly flow, we may see some high
clouds stream in from remnant showers and thunderstorms that were in
the western Great Lakes region Wednesday night, but at this time it
does not look like we`ll have a trigger for showers and
thunderstorms during the day on Thursday.

That will change Thursday night as we will see a moderately strong
cold front move through the region. The moist southerly flow ahead
of the front will make for a mild night, with the ECMWF Extreme
Forecast Index highlighting unusually warm conditions. The surface
convergence ahead of the front will lead to numerous showers, with
greatest chances as you head northward. Trends in the data seem to
suggest most of this activity stays north of the International
Border, with more coverage of showers north and west of the
Adirondacks. With the system`s low pressure area tracking through
northern portions of Canada and progressive nature of the front, any
heavy showers will be short lived and thunder chances look minimal.

In contrast, more widespread shower activity is expected during the
day Friday as a wave of low pressure passes along the front right
through our region. Timing and location of this precipitation is
hard to pin down, but mean onset timing currently is roughly from 6
AM in northern/western areas to mid morning in the central/southern
Champlain Valley to the early afternoon in southeastern Vermont. The
early morning timing of the frontal passage is a limiter to
thunderstorm chances. The more active scenario for Friday, which
features at least 500 J/kg CAPE in the southern half of Vermont
Friday afternoon, is shown by only 20% of the latest global model
guidance and is consistent with the GEPS overall showing a slower
frontal passage.

Due to the frontal passage, high temperature Friday are much more
uncertain than on Thursday. In fact, the forecast has changed
substantially just since this last morning. Our whole region may be
on the cool side of the front during the day, so it would not be
surprising to see temperatures top out in the 60s and 70s for most
locations on Friday. Rainfall also is rather uncertain, but
ingredients for at least some rain are on the table even if amounts
are not more than a quarter to half an inch. For now, likely
(generally 55-70%) PoPs peaking between 2 and 8 PM looks reasonable.
With upper height falls, some showers also could be capable of
producing thunder if there is enough surface heating. Given the
generally uncertain forecast, a slight chance of thunder areawide is
offered for those afternoon/evening hours before sharply drier air
arrives.

The dry air mass looks to arrive and sustain itself over our region
for the entire weekend with crisp air with a large ridge of
seasonably strong high pressure working in from the northwest. When
it sits right overhead Saturday night, temperatures will get down
right chilly in the low to mid 40s by daybreak Sunday. Abundant sun
will help temperatures surge well into the 70s or low 80s by Sunday
afternoon, a few to several degrees warmer than Saturday. Enjoy the
weekend`s weather if you can, as signals for very hot weather are
showing up, especially just beyond this forecast period, next
Tuesday through Thursday. There is a near certainty (greater than
80% chance) of heat concerns for our region during at least part of
that time frame.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
Through 00Z Wednesday...OVC stratus clouds will persist through
the night, lowering to low MVFR/IFR levels between 03Z and 08Z.
Best chances of IFR conditions will be over higher terrain
including KSLK after 03Z and KMPV after 06Z. Will see some areas
of mist and drizzle overnight, most prevalent over higher
terrain, which may reduce visibilities to MVFR/IFR levels at
KMPV and/or KSLK. Visibilities will improve to widespread P6SM
and ceilings lift to VFR after 15Z for most locations. By 18Z,
expecting widespread VFR conditions. Winds from the
west/northwest at 5-10 knots will become light and variable
overnight, then trend calm overnight.

Outlook...

Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Slight chance SHRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. Chance SHRA, Slight chance TSRA.
Friday: Mainly VFR, with local MVFR possible. Likely SHRA, Slight
chance TSRA.
Friday Night: Mainly VFR, with local MVFR possible. Chance SHRA.
Saturday: VFR. NO SIG WX.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...Taber
NEAR TERM...Taber
SHORT TERM...Kutikoff
LONG TERM...Kutikoff
AVIATION...Duell