862
FXUS61 KBTV 130024
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
824 PM EDT Fri Jul 12 2024

.SYNOPSIS...
Scattered showers and a few thunderstorms are expected this
afternoon and Saturday but no additional flooding is expected at
this time. Seasonably warm temperatures in the mid 80s to lower 90s
are expected Sunday through Tuesday ahead of a cold front on
Wednesday that will bring another round of rainfall to the region.
Following the frontal passage, a return of cooler and less humid air
is expected.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 824 PM EDT Friday...While not impactful, a
meteorologically interesting little event will be unfolding this
evening. Showers are expected to blossom along the "cool" side
of a quasi-stationary front to our southeast as an upper level
trough swipes at us from the west. In coordination with WFO ALY
and based on model guidance trends, we did increase rainfall
through 2 AM into the 0.25" to 0.4" range in portions of
southern Vermont. This area would find the rain beneficial.
Farther north, moderate showers are less likely but will have to
watch radar trends. Forecast soundings show very limited
instability at cold temperatures to support thunder chances, so
have removed thunderstorm chances.

Previous Discussion...
Scattered rain showers have developed across the region today
in response to an upper level trough over the eastern Great
Lakes leading to increased aloft. Taking a look at some
mesoanalysis data, we do have around 500 J/kg of CAPE with
decent effective shear of 30- 40 knots which could support an
isolated thunderstorm or two. With PWATs around 1.3" to 1.5", we
could see a burst of moderate to heavy rain with any
thunderstorms that develop but additional flooding threats are
unlikely given the isolated nature of the storms this afternoon.
With the loss of heating this evening, showers and
thunderstorms are largely expected to dissipate although a few
showers may linger through the overnight period. With some
clearing in the skies expected tonight, widespread fog is
expected to develop given recent rainfall and light winds. Fog
coverage will largely depend on skies clearing but where skies
clear it`s feasible to think visibilities could drop well below
1 mile at times during the pre-dawn hours.

Saturday could be an interesting day across the North Country with
the latest run of the CAMs indicating we could have more coverage in
showers and thunderstorms. An upper level low will pass well to the
north of us but the trough axis is likely a trigger for the
development of a few showers and thunderstorms. The HREF is
currently showing mean CAPE values in the afternoon of 1000-1500
range which could support more intense thunderstorms as well as
increased precipitation rates. These will need to be monitored
closely to ensure none of these storms pass over the areas that
received copious amounts of rainfall over the past few days but the
flood threat looks minimal as it`ll take 1-1.25 inches of rain in an
hour to produce any new flash flooding. The threat for thunderstorms
will end quickly as we head into the evening hours with another
round of widespread fog expected again Saturday night.

&&

.SHORT TERM /SUNDAY NIGHT/...
As of 309 PM EDT Friday...High pressure will build in throughout the
day on Sunday, allowing temperatures to climb an additional degree
or two over those seen on Saturday. The current forecast would
result in us hitting 90 in a large portion of the Champlain and
Connecticut river valleys, with temperatures a few degrees cooler at
higher elevations. The western parts of our CWA will also be several
degrees cooler. Late Sunday night, we do see the potential for a
line of showers to come through along a weak shortwave. These
showers will not produce significant precipitation.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 309 PM EDT Friday...The first half of the week brings the
potential for a heat wave, with temperatures at or near 90 for three
straight days in valley locations. These high temperatures will be
combined with high surface moisture content to produce uncomfortable
to possibly risky conditions. Please ensure you are taking
appropriate precautions to avoid heat stress.

We`ll finally get a welcome relief from the heat and humidity as a
cold front sweeps through Northern New York Wednesday or Wednesday
Night. The front will bring widespread shower activity, but the
rapid speed of the system means we are not anticipating any
additional flooding with this system. Current NBM probabilities
show less than a 25% chance of any location receiving even a
half inch or rain.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Through 00Z Sunday...Tricky forecast for climatologically
favored IFR sites overnight, with possible stratus and/or fog
at SLK and MPV mainly after 04Z. Other locations are expected
to see mainly VFR conditions through the period aside from any
visibility reductions from isolated to scattered showers.

At MPV (and RUT), a plume of mid level moisture and possibly
brief moderate rain will move northward most likely impacting
these sites between 04 and 08Z. If this pans out, increased
surface moisture and calm winds will support fog between 08Z
and 12Z at MPV. Meanwhile at SLK skies are primed to be mainly
clear to start the night, and with forcing for clouds/showers
set up to the east, there may be a window for dense fog to
develop. Given the uncertainty, a tempo during the 04Z to 08Z
period of 2SM was used. Fog at other sites is relatively
unlikely with chances too low to mention.

As the sun rises on Saturday, any fog will quickly dissipate
with VFR conditions expected thereafter. We will see chances for
showers and maybe even a thunderstorm or two on Saturday,
especially after 18Z.

Outlook...

Saturday Night: VFR. Patchy BR.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. Chance SHRA.
Monday: Mainly VFR, with local MVFR possible. Chance SHRA, Chance
TSRA.
Monday Night: VFR. Chance SHRA, Chance TSRA.
Tuesday: VFR. Chance SHRA, Chance TSRA.
Tuesday Night: VFR. Chance SHRA, Slight chance TSRA.
Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.

&&

.HYDROLOGY...
As of 310 PM EDT Friday...Rivers continue to fall with just the
Barton River at Coventry remaining in flood stage. Additional
rainfall from showers and thunderstorms today and Saturday may
drop 0.25" to 0.5" locally but shouldn`t produce any additional
river flooding. Visit water.noaa.gov for the latest river
hydrographs and current flood related products.

&&

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

&&

$$
SYNOPSIS...Clay
NEAR TERM...Clay/Kutikoff
SHORT TERM...Langbauer
LONG TERM...Langbauer
AVIATION...Clay/Kutikoff
HYDROLOGY...Team BTV