-- Discussion containing changed information from previous version are highlighted. --
933
FXUS61 KBTV 122305
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
705 PM EDT Wed Jun 12 2024

.SYNOPSIS...
Comfortable conditions will trend warm as highs are expected to
reach into the 80s on Thursday. A cold front will slice through
the region on Friday to bring cooler conditions along with some
showers in the morning, and possibly thunderstorms during the
afternoon mainly in southern areas. Following spectacular
weekend weather, summer heat and humidity will build early next
week with potential for very hot weather.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
-- Changed Discussion --
As of 704 PM EDT Wednesday...Forecast is on track with minimal
changes needed in this update. Clouds will continue to be
variable for the next few hours with clearer skies eventually
winning out tonight. Some valley fog is expected, and
temperatures will drop into the mid 40s to upper 50s. Previous
discussion below:

Previous discussion...Weak low pressure spinning over
the Gulf of Maine has promoted some northerly flow over Vermont
and lingering stratocumulus. Meanwhile, light southwest flow is
present in much of northern New York ahead of a more substantial
low pressure area moving northeastward through Ontario. Through
tomorrow night, that system and its associated
troughs/shortwaves will be the forcing for shower chances as
southwesterly low level flow overspreads the region. For
tonight, light flow and clearing skies will promote a chance of
dense river valley fog early tomorrow morning, with most
coverage in eastern Vermont where winds just above the surface
look particularly light compared with areas farther west.

Until tomorrow evening, expect continued dry weather. Moderately
dry air and abundant sunshine should support highs in the low to
mid 80s in most spots as our air mass modifies on the low level
southwest flow. Still looks like some deep mixing will develop
given this dry air and increasing pressure gradient, which will
promote breezy conditions. Momentum transfer in the boundary
layer suggests in locations like Ogdensburg, New York a few
gusts over 30 MPH will be possible during the late afternoon and
early evening. Instability will likely be between 500 and 1000
J/kg across northern New York, tapering off farther east, during
that period, but the forcing for convection will remain to our
west such that we still have a low chance of precipitation.
Towards midnight, and then through the pre-dawn hours, isolated
to scattered showers, perhaps with a thunderstorm or two, will
roll eastward through primarily northern portions of our region
along a pre-frontal trough. It will be a much warmer night than
recent ones, especially given trend towards less precipitation
coverage; without rain cooled air, temperatures in the wide
valleys could stay in the upper 60s to low 70s for much of the
night.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 320 PM EDT Wednesday...A cold front will pass through the
region on Friday and bring some showers and thunderstorms. There is
a low possibility of severe storms, mostly across southern Vermont,
and the SPC included that area in their marginal risk category. As
the front passes through on Friday, there should be more than enough
1000-500 MB shear. The GFS/Euro ensemble mean is around 50 KTs and
over 90 percent of the members have greater than 30KTs. However, the
best dynamics associated with the front are to the south of the
region by the time diurnal heating occurs, so instability will be
limited. CAPE values generally look to reach between 500-1000 J/Kg,
with the highest values over southern Vermont. This should keep the
severe threat mostly to the south. These showers should be out of
the region by Friday evening and Friday night should be dry. Highs
on Friday look to be in the mid 70s to upper 80s with the highest
temperatures in southern Vermont where the front reaches last. Lows
will fall back into the 40s and 50s Friday night.

&&

.LONG TERM /...SATURDAY THROUGH WEDNESDAY/...
As of 320 PM EDT Wednesday...A surface high will build into the
region this weekend and lead to a stretch of wonderful weather.
There will be mostly sunny skies, highs in the 60s and 70s, and
low humidity. With clear skies and light winds, temperatures
should fall back into the 40s and low 50s across the region
overnight, though the upper 30s are possible in the coldest
hollows Saturday night. Enjoy the weather because by Monday, the
high will shift to the east and a return southerly flow will
bring increased heat and humidity. The position of the high
should cause the flow to be more southwesterly and this would
prevent any marine air from moderating the temperatures. Highs
above 90 in the broad valleys are becoming likely on Tuesday and
Wednesday but whether they will last for a third day on
Thursday and cause a heat wave remains uncertain. 925 mb
temperatures currently look to be around the 24-28 celsius range
Tuesday and Wednesday, which would support temperatures well
into the 90s. NBM probabilities suggesting a 40-50 percent
chance of Burlington reaching 100 on Wednesday appear to be
erroneous due to bias correction issues, but that should not
take away from the fact there will be heat related impacts. Dew
points also look to approach 70 by Wednesday, so the heat will
be accompanied by high humidity. This will help lows stay in the
upper 60s and low 70s Tuesday and Wednesday nights, so
nighttime relief looks to be minimal. There is a little
uncertainty on Tuesday as a shortwave may ridge along to top of
the ridge and bring a few clouds and showers. This could limit
highs slightly that day. A cold front currently looks to come
through on Thursday and bring an end to the heat stretch once it
passes.

&&

.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Thursday...Mainly VFR conditions are expected during
the period. Stratocumulus will remain through the rest of the
day, which will flirt with MVFR ceiling height at the higher
elevation sites. Overnight as skies clear and winds aloft become
light there may be IFR conditions due to dense fog, especially
from 07Z to 12Z. Greater chances (~20%) will be in eastern
Vermont, with 3SM BR currently indicated at EFK and MPV until
confidence increases/lead time decreases. Winds will remain
light and variable or terrain-driven through about 12Z, then
modest south or southwesterly winds will develop. At MSS gusts
could ramp up to about 20 knots towards Thursday afternoon.


Outlook...

Thursday Night: VFR. Chance SHRA, Slight chance TSRA.
Friday: VFR. Chance SHRA, Slight chance TSRA.
Friday Night: VFR. Slight chance SHRA.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. Slight chance SHRA.
Monday: VFR. Slight chance SHRA, Slight chance TSRA.

&&

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

&&

$$
SYNOPSIS...Kutikoff
NEAR TERM...Kutikoff/Storm
SHORT TERM...Myskowski
LONG TERM...Myskowski
AVIATION...Kutikoff