356
FXUS61 KBTV 260233
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1033 PM EDT Fri Apr 25 2025

.SYNOPSIS...
Seasonably warm and cloudy conditions with a few light showers
will give way to a widespread soaking rain overnight into
Saturday morning. A brief period of partial sunshine ahead of a
strong cold front will help temperatures climb before sharply
colder conditions arrive. With an upper level low ambling across
the region Sunday, cold rain and high elevation snow is
expected. Mainly dry and seasonably warm conditions will follow
for much of the work week, although thunderstorms are possible
on Tuesday.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 1031 PM EDT Friday...Showers upstream moving across
central New York will lift into our region overnight. Still
anticipating widespread wetting rain overnight. No large changes
needed with this update. Previous discussion follows.

A dynamic, intensifying low pressure system will move over the
eastern Great Lakes tonight and pass right across northern New
York and northern Vermont during the day. As such, quite a bit
of variety in weather is expected including periods of rain,
isolated to scattered thunderstorms, and much cooler conditions
tomorrow night.

For tonight, showers with embedded thunder across central New
York associated with a mesoscale low pressure area will move
across western portions of northern New York roughly between 6
and 11 PM. Based on marginal instability and modeled forecast
soundings, have left thunderstorms out of the forecast but a
non-zero chance of lightning exists. Otherwise, the ongoing
light rain showers in portions of our region will continue to
lift to the north this evening. The main area of widespread rain
expected during the first half of the weekend is on track to
arrive largely between 1 AM and 3 AM and persist through much of
the morning, tapering off from west to east between 8 AM and
noon. A soaking rain of 0.5" to 1" is expected, with the higher
amounts favored in southern portions of Essex County, New York
into central and eastern portions of Vermont, especially in
upslope favored areas with a shallow and moist southeasterly
wind direction.

Following this rain, attention turns to the instability that
can develop during the midday hours ahead of the surface cold
front. The timing of the front suggests this potential is mainly
in Vermont/eastern Adirondacks as colder and stable air will be
making its way into New York quickly as winds turn
southwesterly/westerly. Given the strength of the front and
progged 700 millibar moisture, if there is sufficient heating
showers become widespread ahead of the boundary. The NAM3/HRRR
show a similar axis of instability with marginal surface-based
values in the 500 - 1000 J/kg, supportive of at least chances of
thunderstorms. There is limited potential for strong gusts
associated with any linear features that can develop, given
effective shear of near 30 knots. Moist profiles with limited
CAPE suggest brief downpours and gusty, but not strong, gusts is
most likely.

Moving into Saturday night, sub-freezing 850 millibar
temperatures will settle into the region with mountain summits
above 3000 feet seeing rain showers change to snow overnight.
Steady precipitation will wrap around the departing surface low
pressure system, such that northern New York will see the bulk
of the light rain/snow overnight. Following highs in the 60s on
Saturday, lows Saturday night look to slip into the 30s to low
40s.

&&

.SHORT TERM /SUNDAY NIGHT/...
As of 312 PM EDT Friday...Sunday appears likely to be cold and
dreary. The 540dam 1000-500mb thickness line will cross east as
a compact upper low tracks overhead and to our east. Deep
moisture will wrap around the western side of surface low
pressure moving along the Maine Coast. Elevation dependent rain
and snow will move north to south over the area with breezy and
cool weather anticipated. Temperatures will linger in the mid
40s to lower 50s from the Adirondacks eastwards. The low will
shift far enough east for the St. Lawrence Valley to still push
60 with partial clearing. Lower valleys will be breezy and
rainy. Higher elevations should stay in the 30s and experience
sloppy, wet snow. This weather feature will at least be
progressive enough to shift east by nighttime. Steady north
winds will result in a cool Monday morning in the 30s to near
40.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 312 PM EDT Friday...As has been the general pattern,
we`ll have high pressure set up for a couple days. Warm
advection takes over pretty fast, and so we warm right up into
the 60s to near 70 on Monday. On Tuesday, the previous upper low
will have stalled across the Canadian Maritimes. With that and
the ridge cresting overhead, there should be plenty of dry,
subsident air across the region. Initially, there could be some
gusty winds combined with RHs around 30-35 percent, but with the
quickness of incoming precipitation and steady intervals of
rain over the last month, not anticipating this to be of much
concern. Temperatures will reach well into the 70s Tuesday
afternoon. Moisture will increase ahead of a prefrontal trough
that will slide east during the afternoon. Ensemble guidance
indicates probability of SBCAPE greater than 300 J/kg highest
over the St. Lawrence Valley around a 30% chance. This is mainly
from the timing being close to sunset across Vermont beyond the
best diurnal heating. The EPS MUCAPE percentages are running
closer to 100%, which makes sense given the better resolution.
Assessing the probability that these values align with at least
30 knots of shear, the EPS also indicates a 60% chance of their
collocation. The Storm Prediction Center has already highlighted
the potential for the St. Lawrence Valley. With such a dynamic
995 mb surface low passing south of James Bay and 70s coupled
with upper 50s dewpoints across that region, this seems like a
real possibility. As the prefrontal trough slides east Tuesday
evening, the loss of instability will cause a weakening trend as
precipitation slides across Vermont overnight.

Post-frontal gusts will lead people to believe we might be in
for another cold day. Surface high pressure is going to be
rather quick to come back, though. Skies should trend clear,
winds will subside shortly after noon, and then temperatures
will make their way into the 60s. After a couple dry days,
another dynamic weather system appears poised for Friday
evening.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Through 00Z Sunday...A dynamic, intensifying low pressure
system will move over the eastern Great Lakes tonight and pass
right across northern New York and northern Vermont during the
day tomorrow. We can expect periodic showers for much of the
next 24 hours, though they become organized into two more
distinct waves, one arriving overnight tonight and the next
tomorrow afternoon. Visibilities are not expected to be overall
low, with blanket 4+ miles vis for most sites in the TAF,
however, it is not out of the question for occasional and
unpredictable heavier showers lowering vis further at times in
any more potent showers or thunderstorms. Ceilings will also
decrease with these showers, lowering to 3000 feet above ground
level or below by about 10Z-14Z Saturday and remaining low for
the remainder of the TAF period (through 00Z Sunday). Ceilings
could fall even lower below 1000 feet at several sites, perhaps
all, but highest confidence is for SLK, MPV, RUT, and MSS as the
Champlain Valley will likely scour out low clouds the fastest
tomorrow (BTV and PBG). Highest confidence for timing of these
IFR ceilings will be 12Z-16Z onward. Winds will be out of the
south or southeast for much of the night tonight, turning more
westerly to northwesterly tomorrow. LLWS concern will be brief,
around 10Z-15Z, for BTV, SLK, MPV, EFK, and RUT.


Outlook...

Saturday Night: MVFR/IFR conditions possible. Chance SHRA.
Sunday: Mainly MVFR, with local IFR possible. Likely SHRA.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. Chance SHRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday: Mainly VFR, with areas MVFR possible. Slight chance
SHRA.

&&

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

&&

$$
SYNOPSIS...Kutikoff
NEAR TERM...Kutikoff/Neiles
SHORT TERM...Haynes
LONG TERM...Haynes
AVIATION...Storm