592
FXUS61 KBTV 131133
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
733 AM EDT Sat Jun 13 2026
.WHAT HAS CHANGED...
As of 319 AM EDT Saturday...
No significant changes have been made at this time. The threat for
strong to severe thunderstorms is a little lower than before but the
threat for localized flooding has gone up slightly.
&&
.KEY MESSAGES...
As of 319 AM EDT Saturday...
1. Strong to severe thunderstorms and localized flooding
possible on Sunday.
2. Big pattern change expected to occur Sunday night into
Monday with temperatures returning to more seasonable values.
3. Expect widespread rain and unseasonably breezy conditions on
Thursday. Near normal temperatures are likely for most of the
midweek to late week period.
&&
.DISCUSSION...
As of 319 AM EDT Saturday...
KEY MESSAGE 1: Much quieter weather is expected today with mostly sunny
skies allowing temperatures to warm into the upper 70s to upper 80s.
For Sunday, the threat for strong to severe thunderstorms looks to
be on track with a strong cold front slated to move across the
region Sunday afternoon and through the overnight hours. Forecast
model soundings for Sunday afternoon are all over the place
unfortunately with some models depicting a modest EML with a strong
inversion below it. It`s unlikely we would break the inversion the
models are depicting if the event plans out as the NAM and NAM3
currently depicts. We should have ample instability around 1000 to
1500 J/kg coupled with deep layer shear in the 50 knot range which
would be enough to support some supercell structure if we can
get an surface based convection. RAOB sampling this morning will
help give models a better handle on the EML and how the upper level
pattern is developing which will give us a better handle on how
Sunday may play out. The more concerning aspect at this time is the
potential for some heavy rainfall. All guidance is showing a plume
of deep layer moisture advecting from the Gulf and western Atlantic
which will help push PWATs near 1.5" Sunday afternoon. Some models
even depict PWATs up to 2.0". The soundings actually look favorable
for heavy rain with tall skinny CAPE profiles with a deep warm cloud
depth layer. It`s possible we could see rainfall amounts of 1-2" in
places with even localized higher amounts possible given the
convective nature of the event. We have added heavy rainfall wording
to the thunderstorms on Sunday as they could become problematic. We
will watch this closely and have some better understanding on the
potential impacts in subsequent forecasts.
KEY MESSAGE 2: A strong cold front will push through Sunday night into
Monday morning ushering in a much colder airmass. Temperatures will
return to more seasonable values for Monday and Tuesday with highs
climbing only into the mid 60s to mid 70s. We will be underneath the
influence of an upper level trough once again for much of next week
which will keep some chances for showers each day with a pool of
colder air aloft and several weak disturbances traversing the
longwave pattern. None of these showers should be strong as we will
be lacking significant moisture and instability.
KEY MESSAGE 3: Focus of the days 4 through 7 period (Tuesday night
through Friday night) is on the expected Colorado low expected to
develop and track northeastward through the Great Lakes region. This
looks like an unseasonably strong system, with the ensemble MSLP
through this period roughly 995 millibars, near the 1st
climatologically percentile. The member storm tracks are fairly well
clustered through Michigan and into central Ontario and Quebec
Thursday night. That being said, some interesting differences in
timing are noted with the GEPS being quite slow compared to the ENS
& GEFS, and the GEFS for the 00Z initialization (latest data)
shifted a bit northward closer to the Grand Ensemble track.
Currently the probabilities of a 24 hour rainfall greater than 1
inch ending Friday at 8 am (rain is most likely from Thursday
morning through Thursday evening) are about 25 to 50%, lowest in the
northern Champlain Valley and greatest in much of northern New York,
especially towards the St. Lawrence Valley and southern portions of
the Adirondacks.
A more northward track which would reduce potential for heavier
rainfall amounts but lead to greater risk of stronger wind gusts.
While at this time range a broad slight chance of thunderstorms is
also reasonable, looking at forecast soundings and the atmospheric
environment it appears a low tropopause will limit cloud depths and
the near surface temperatures will struggle to warm enough to
produce much instability with moist adiabatic lapse rates present.
So at this time, the primary possible hazard looks related to winds,
mainly out of the south, during the day on Thursday. The average 24
hour maximum wind gust in the latest NBM provides a conservative 30
to 35 MPH range for much of northern New York and the Champlain
Valley; reasonably worst case scenarios in the 90th percentile are
in the 40 to locally 50 MPH range.
Behind this system, cyclonic flow will lead to continued chances of
showers and as typical in a cold season pattern probabilities are
greater in the Adirondacks and northern/northeastern higher terrain
in Vermont.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Through 12Z Sunday...Prevailing VFR flight conditions will
continue through the period with mainly SKC for most terminals.
Winds will generally remain westerly today and shifting
southerly tonight. Well mixed air through sunset supports modest
gusts, most favorable with a southwesterly channeling scenario
at MSS. As surface winds decrease after 00Z, a surge of
southwesterly winds into northern New York is expected above the
surface, supporting LLWS for at least a few hours. Farther
east, while there will be enough winds aloft to preclude fog
formation, the magnitude appears to be light enough to leave
LLWS out of the TAF.
Precipitation remains unlikely, but there are indications
especially after 06Z that isolated to scattered showers will
slide across northern portions of the airspace. MSS currently is
the only site that categorically looks likely to see some rain,
although greatest chances are towards the very end of the TAF
period. If trends continue, PROB30 and/or TEMPO groups will be
needed at this site.
Outlook...
Sunday: Mainly VFR, with local MVFR possible. Chance SHRA, Slight
chance TSRA.
Sunday Night: Mainly VFR, with areas MVFR possible. Chance SHRA,
Slight chance TSRA.
Monday: Mainly VFR, with local MVFR possible. Chance SHRA.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Chance SHRA, Slight chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Clay
DISCUSSION...Kutikoff/Clay
AVIATION...Kutikoff
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