465
FXUS61 KBTV 231727
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
127 PM EDT Wed Apr 23 2025
.SYNOPSIS...
Fair weather is expected today and tonight with high pressure in
control. Some scattered rain showers will move in Thursday, and a
rumble of thunder can`t be ruled out. The better chances for a
more widespread wetting rainfall will come Friday night into
Saturday.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 122 PM EDT Wednesday...No changes needed to the
forecast. It continues to be a pleasant day across the region,
with sunny skies and temperatures in the upper 50s and 60s.
Previous discussion...Pleasant weather is on tap today and
tonight as high pressure drifts across the region. We`re
expecting ample sunshine today, with just some lingering clouds
over portions of northeastern VT. Northwest winds will be a
little on the breezy side, but not as strong as we saw
yesterday. Highs will generally be in the mid 50s to mid 60s,
with perhaps some lower 50s in the Northeast Kingdom if clouds
hang around longer than anticipated. Clouds will start to
increase late tonight ahead of our next system, but most areas
will likely remain mostly clear through daybreak Thursday. Lows
will be in the 30s areawide.
Our dry weather comes to an end on Thursday as a weak shortwave will
slide through zonal flow aloft. The associated weak surface low will
likewise move eastward from the Great Lakes and directly over our
forecast area during the day. Consensus of the latest CAM runs show
an area of showers moving into our region with the preceding warm
front Thursday morning. Given the amount of dry air in place, feel
this is a bit overdone with the main impacts to be just increasing
cloud cover during the morning hours. Better chances for showers
arrive later in the day as the surface low moves through, somewhere
in the northern/central portions of our forecast area, dragging a
cold front along behind it. How much rain we get in the morning
hours will impact thunderstorm potential with the afternoon showers.
While there will likely be at least some elevated instability in the
afternoon, enough for a few rumbles of thunder, there are some
indications that there could be 400+ J/kg of SB CAPE if any morning
rain showers and cloud cover are minimal and/or move through fairly
quickly, allowing the atmosphere to recover by the second round in
the afternoon. There are still minor differences between model
solutions with these factors, so we`ll need to continue to monitor
trends going forward. For now, have gone with a blend of a few
different model solutions, which keeps precipitation chances fairly
low in the morning, and keeps afternoon thunder chances limited to
slight, mainly in the Adirondacks and south-central Vermont. These
parameters will also play into highs for Thursday; note that there`s
a pretty big range in MOS guidance (the MET has 57 for BTV, while
the MAV has 67). With more clouds expected in the north, have stayed
with highs in the upper 50s to low 60s along the international
border, with central/southern areas getting into the mid 60s to low
70s.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
As of 347 AM EDT Wednesday...A shortwave will continue to track
across Quebec with some slight shower chances across northern
Vermont. Any showers that develop, especially in southern Vermont,
could have a few rumbles of thunder. QPF values remain on the lower
side with this shortwave with only a few hundreths of an inch
expected. Showers will quickly taper off late Thursday night with
lows falling into the 40s. Friday looks to start off dry with brief
ridging and widespread cloud cover throughout the day ahead of the
next system tracking out of the Great Lakes. Ensemble guidance has
trended the center of the system further north, which would lead to
more southerly flow and increased waa. Deterministic guidance still
indicates a low track over the region keeping temperature guidance
on the low side. Temperatures thus could trend towards the warmer
side of guidance Friday afternoon into the mid to upper 60s as winds
shift from the south. A warm front associated with the low will
slide into the area late Friday afternoon with increasing
precipitation chances into the evening. A few rumbles of thunder are
possible in portions of the Adirondacks and southern Vermont where
surface CAPE and isentropic lift are most conducive for any
instability to form. CAPE values remain low, however, in the 100-200
J/kg range.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
As of 347 AM EDT Wednesday...A wet start to the weekend is in store,
with dry and warming temperatures following to start next week. A
low will track out of the Great Lakes Friday evening and track
northeast across the St. Lawrence valley and into Canada. Ensemble
tracks have trended this system further north which would draw in
warmer air allowing for potentially more instability to form Friday
night. While deterministic guidance shows low CAPE, ensembles show a
slight upward trend, albeit still only in the 50-150 J/kg range.
Furthermore, any more northward trends would keep surface
temperatures on the warm side with additional mixing of the column
which could keep any instability in place longer through Friday
night. Any thunderstorm chances look best across northern New York,
and portions of the Champlain Valley. QPF from this system is also
challenging given the northward uncertainty. If the system were to
follow a more southerly path directly over the North Country,
overrunning, and stratiform rain would lead to more uniform
precipitation accumulations around a quarter to half an inch.
However, under the northward path across Quebec, more convective
elements from an associated cold front are possible with less
overall widespread precipitation. This is exemplified in the NBM 24-
hour precipitation probabilities which show a 40-60% chance of 0.5
inches or greater, indicating for most that this will be a wetting
rain, with an upward trend in greater than 0.75 inches to near 40%
across portions of central Vermont, noting heavier precipitation
from possible convective elements. Rivers and area waterways could
see some rises, however, flooding risks remain low. Temperatures
will be in the upper 40s to near 50 Friday night given the
precipitation.
As the system exits Saturday, lingering precipitation chances remain
uncertain. The ECMWF ensembles indicate the low will deepen over the
area keeping precipitation chances through Saturday, however the
GEFS shows the low deepening over portions of Maine, leading to a
drier Saturday. The overall trough amplification will need to be
monitored for trends for low track clarity. Regardless, Saturday
night temperatures will fall into the 30s with slight rebounding
temperatures Sunday in the 50s and 60s. Northerly flow Sunday could
lead to breezy conditions across the Champlain Valley with top of
the boundary layer gusts near 30 knots. Much drier air and warming
temperatures are expected for the start of next week as a broad area
of high pressure builds overhead.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Thursday...VFR conditions will prevail across all
terminals through the forecast period, with mostly clear skies
currently persisting through the afternoon and most of the
overnight hours. Towards 06Z, some high and mid-level clouds
will begin to increasing across the region from the west. Winds
this afternoon have generally been west/northwesterly between 7
to 15 knots with some stronger gusts. Winds will trend light and
terrain driven this evening, generally after 00Z before
increasing again towards the end of the TAF period.
Outlook...
Thursday Night: VFR. Chance SHRA.
Friday: VFR. Chance SHRA.
Friday Night: Mainly VFR, with areas MVFR possible. Definite
SHRA, Slight chance TSRA.
Saturday: Mainly MVFR, with local IFR possible. Chance SHRA.
Saturday Night: MVFR/IFR conditions possible. Chance SHRA.
Sunday: Mainly VFR, with areas MVFR possible. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Hastings
NEAR TERM...Hastings/Kremer
SHORT TERM...Danzig
LONG TERM...Danzig
AVIATION...Kremer
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