733
FXUS61 KBTV 140615
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
215 AM EDT Sun Jun 14 2026
.WHAT HAS CHANGED...
As of 215 AM EDT Sunday...
Rainfall totals have been increased by a quarter to half of an inch
across the board. Widespread 0.5 to 1.25 inches of rain is now
expected with localized amounts exceeding 2 inches possible. WPC has
increased the flash flood risk from Marginal to Slight for portions
of our forecast area. The severe threat looks on track for late this
afternoon into the evening.
&&
.KEY MESSAGES...
As of 215 AM EDT Sunday...
1. Strong to severe thunderstorms and localized flooding
possible today and tonight.
2. A return to more seasonal weather early next week with daily
chances for showers.
3. Another storm system is expected to bring widespread
rainfall to the region on Thursday.
&&
.DISCUSSION...
As of 215 AM EDT Sunday...
KEY MESSAGE 1: We`ve got a bit of a messy 24 hours ahead of us with
multiple rounds of showers and thunderstorms possible ahead of a
strong cold front late this afternoon into this evening. Currently,
we have a bit of a deformation axis setting up across the St.
Lawrence Valley which is allowing for a few showers with embedded
rumbles of thunder to track across the Valley. Minimal rainfall has
been reported thus far but the main concern is how the longwave
pattern is beginning to shift. Moisture will continue to advect
eastward throughout the day today with a little boost from the Great
Lakes to help bump PWATs up near 1.75 inches across northern New
York and 1.25 to 1.5 inches elsewhere. These plume of greatest
moisture is likely to be trapped under the developing deformation
axis which could lead to a longer period of rainfall; some of which
is expected to be very heavy at times. Model soundings across New
York show between 1000 J/kg of CAPE (GFS) to 2000 J/kg of CAPE (NAM)
this afternoon with an increasing warm cloud depth layer. These
soundings support very heavy rainfall and with a synoptic cold front
with strong frontogenesis/convergence, it`s feasible we could see
some localized 2.5+ inch rainfall totals in some locations from
northern New York across northern Vermont (best chances near the
International border). Those with outdoor plans this afternoon, and
especially tonight, are advised to keep an eye on the weather as we
could be in store for some heavy rain and isolated flash flooding.
In addition to the hydrological concerns, we`re also keeping an eye
on the severe potential this afternoon into the evening. The forcing
between the upper level trough and surface cold front are slightly
displaced but the cold front is expected to move across the region
right around peak heating. With temperatures in the mid to upper 80s
and dewpoints in the lower 60s, plenty of instability will be
present. We are looking at "inverted v" soundings in the low level
with model forecasted DCAPE in the 600-1000 J/kg range. This should
support some damaging wind gusts with even a few wet microbursts
possible in stronger storms this afternoon. Deep layer shear in the
50 to 60 knot range will help organize thunderstorms with a few
supercells possible. The main thinking is that the cold front would
quickly catch up to any supercells with the main storm mode being
multicellular/QLCS. Damaging winds will be the main concern for sure
this afternoon with a brief spin-up tornado unlikely but possible.
We will be hard pressed to see large hail greater than 1 inch in
diameter due to a high melting layer but we could still see smaller
hail within thunderstorms this afternoon. The main window for severe
storms will be between 4 PM and 10 PM.
KEY MESSAGE 2: Following the passage of the cold front, we will be
under the influence of an upper level trough once again. A return to
more seasonal temperatures with highs in the mid 70s to lower 80s is
forecast through Wednesday with lows in the 50s and 60s. Broad
cyclonic flow could yield some isolated to scattered diurnal shower
chances through the first half of the upcoming week but no
significant rainfall is expected at this time.
KEY MESSAGE 3: Models continue to be in very good agreement that
another potent storm system will track near the St. Lawrence Valley
on Thursday and bring widespread rainfall. There is enough
confidence in the guidance to include 80+ PoPs at this time. There
is the possibility for some heavy rainfall again on Thursday and we
have already begun coordinating with the Weather Prediction Center
about the potential for at least a marginal risk for flash flooding.
Some of the ensemble guidance is already hinting at 1-2 inches of
rain on Thursday so it`ll be something to watch closely, especially
depending on how much rainfall is received from the storms today and
tonight.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Through 06Z Monday...VFR conditions are expected to continue through
midday before more widespread rainfall overspreads the area. MVFR
visibilities are expected as rain begins with ceilings lowering to
MVFR values a few hours behind the onset of rainfall. Some
thunderstorms are expected this afternoon as a strong cold front
moves across the region. We don`t have any mention of TS at this
time as the timing for thunderstorms for any given terminal is
beyond the 6-12 hour timeframe. Winds will increase from the south
this afternoon with some gusty winds up to 20 knots expected in the
Champlain Valley. Winds will likely become erratic near
thunderstorms this afternoon but should settle into a southerly to
southwesterly flow behind the thunderstorms and ultimately veer to
the west/northwest in the wake of the cold front.
Outlook...
Monday: VFR. 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.
Wednesday Night: MVFR/IFR conditions possible. Chance SHRA.
Thursday: Mainly MVFR, with areas VFR possible. Definite SHRA,
Slight chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Clay
DISCUSSION...Clay
AVIATION...Clay
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