453
FXUS61 KBTV 241141
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
741 AM EDT Mon Jun 24 2024

.SYNOPSIS...
An area of low pressure passes over the region today and causes a
cooler and showery day. This low moves out tonight and high pressure
builds in for tomorrow. This will lead to a sunny and much warmer
day. A cold front approaches on Wednesday and brings the
possibility for strong storms and heavy rainfall.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 629 AM EDT Monday... The rain has been slow to move in
from Canada so had to lower PoPs across northern New York. The
rain will still eventually make it but the early morning hours
should now be mostly dry across the North Country. Even if the
stratiform rain struggles to make it, diurnal heating will
cause some instability and therefore showers will develop
during the day. Dew points have also been dropping faster than
forecast so had to lower those as well. Other than that, no
significant changes were made.

Previous Discussion...The center of a 996 mb low is located
over the international border but despite that, the region is
dry save for a couple isolated showers. There have been a few
areas of clearing and this has led to some very patchy fog
formation tonight. The low will move to the southeast tonight,
and stratiform precipitation on the backside over Canada will
enter the region after the center passes through. The surface
cold front is still just over the international border, but it
will slowly pass through tonight and into the day today.
Northwest winds behind the front will clear out any fog. The
upper levels will cool more than the surface tomorrow so diurnal
heating will cause marginal instability, and this will enhance
this stratiform precipitation a little. There is the chance of a
very isolated thunderstorm but there is no severe threat. The
convection will be very low topped, and the stratiform
precipitation and dense cloud cover will severely limit any
diurnal heating. There will be a sharp inversion just above
5,000 FT so the instability would only form below that height.
The cooler airmass and frequent showers will keep temperatures
in the 60s and 70s, and they will generally fall into the 50s
overnight. This area of precipitation moves out tonight and
leads to a dry day on Tuesday. Ridging builds in and with
southwesterly flow at the surface, temperatures will warm
dramatically. 925 mb temperatures will rise into the low 20s
celsius and temperatures look to rise into the 80s at the
surface. The warmest spots could make a run at 90. Humidity
should remain on the lower side with dew points generally in the
50s. The day will start out clear before high clouds stream in
from the west during the afternoon.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 335 AM EDT Monday...Another active day expected on Wednesday as
low pressure well to our north brings a series of fronts through the
region. A warm front will lift north across our area Tuesday night,
and the associated showers will bring light rainfall amounts to
mainly northern NY and northwestern portions of VT. Moisture will
surge northward as flow turns to the south/southwest behind the warm
front. There will be a brief break in the precipitation Wednesday
morning, but expect showers and thunderstorms to develop during the
afternoon and evening hours as the cold front moves through the
region. As has been noted, model soundings still indicate a warm
layer around 800 mb, limiting CAPE values. NAM is also indicating
quite a bit of dry air at mid-levels, which would potentially cause
convection to hold off until later in the day. Still, SB CAPE of
500-1200 J/kg looks reasonable, and when combined with 35-45 kt of
shear, should storms develop, they could become strong or severe. At
the least, locally heavy rain looks to be a threat as PWATs surge
back above 1.50 inches. Showers and thunderstorms will persist into
the evening hours, until a secondary front moves through late
Wednesday night, ushering in drier air. After a somewhat muggy night
with lows in the 60s, highs on Wednesday will be in the upper 70s to
upper 80s. Wednesday night should be a bit more refreshing behind
the secondary front; lows will be in the 50s to around 60F.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 335 AM EDT Monday...High pressure will build across the region
Thursday and Friday, keeping conditions mostly dry. An upper trough
will skirt along the international border Thursday, which may allow
some showers to pop up, especially over the higher terrain. Both
days will be cooler than earlier in the week; highs will range from
the mid 60s to mid/upper 70s both days. The weekend is looking
showery as a series of fronts will bring the threat of showers and
thunderstorms. Temperatures will be seasonable, with daytime highs
in the 70s and 80s and overnight lows in the 50s and 60s.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Through 12Z Tuesday...A cold front will slowly pass through the
region from northwest to southeast during the day today. It
will bring showers, change winds to northwesterly, and bring
lower ceilings behind it. It has already passed MSS and is in
the process of passing through SLK. It should pass BTV, PBG, EFK
and MPV by 18Z, and RUT by 00Z. Behind the front, ceilings will
drop to MVFR at all terminals but IFR is possible for a couple
hours at any of them. There will be on and off showers during
most of the day and a couple of them may be heavy enough to
lower visibilities to MVFR. There is a low risk of lightning
from any of these showers but it cannot be completely ruled out
in one or two of them. The vast majority of showers will not
contain lightning though. Clouds will break tonight and every
terminal should be VFR by the end of the night.

Outlook...

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

&&

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

&&

$$
SYNOPSIS...Myskowski
NEAR TERM...Myskowski
SHORT TERM...Hastings
LONG TERM...Hastings
AVIATION...Myskowski