486
FXUS61 KBTV 151900
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
300 PM EDT Fri May 15 2026
.WHAT HAS CHANGED...
As of 259 PM EDT Friday...
Increased areal coverage of pops on Saturday afternoon across
northern New York and expanded coverage into Vermont by evening.
&&
.KEY MESSAGES...
As of 259 PM EDT Friday...
1. Scattered showers are possible over northern New York on
Saturday afternoon, which spread eastward into Vermont by evening
with warmer temperatures expected this weekend.
2. Warmer temperatures midweek with showers and some
thunderstorms.
&&
.DISCUSSION...
As of 259 PM EDT Friday...
KEY MESSAGE 1: Upper air analysis shows a complex pattern acrs the
Great Lakes into the NE CONUS with deep closed cyclonic circulation
near the 40/70 benchmark, while weak ridge is located over the
central Great Lakes. This ridging is associated with weak axis of
mid lvl moisture and deeper waa with developing westerly flow aloft.
Initially band of moisture dissipates and passes to our north
tonight, but additional s/w energy and moisture over the northern
Plains wl race eastward and impact northern NY by Sat aftn. For
tonight have continued with previous forecaster thinking with some
patchy fog over the central/eastern VT valleys. The bl winds acrs
northern NY are in the 3 to 7 knot range, but are slightly less over
VT. Also, still some uncertainty on how quickly clouds dissipate
tonight with sounding data showing some moisture btwn 850-700mb
layer. Vis satl imagery shows only a narrow axis of clearing slowly
approaching the SLV with some breaks developing over CPV and
southern VT this aftn. Lows generally in the 40s to near 50F tonight.
Timing and areal coverage of precip has increased slightly from
previous 12 to 24 hours on Sat aftn/evening, as the GFS/HRRR is most
aggressive with precip progs, while NAM is less. We are still not
anticipating a washout and any precip wl be <0.10" with greatest
probability of measurable precip over northern NY, especially the
higher trrn. Have bumped pops into the low likely range btwn 21-01z
acrs northern NY and kept pops in the chc range for VT. Developing
southwest 925mb to 850mb jet of 35 to 45 knots should limit threat
of rain showers in the CPV on Sat evening with some downslope
shadowing likely. Did increase winds acrs the SLV and northern
slopes of the dacks on Sat aftn, where localized gusts 25 to 35 mph
are possible. An additional progged 850mb jet of 45 to 60 knots
develops behind the weak sfc boundary late Sat night into Sunday,
but mixing profiles are limited. Strongest winds wl be on summit lvl
on Sat night into Sunday, but localized gusts 25 to 35 mph will be
possible acrs central/southern VT. Progged 925mb temps are 14C to
16C on Saturday supporting highs well into the 70s. Sunday behind
the boundary progged 925mb temps drop btwn 9-13C, supporting highs
mid 60s to mid 70s, except near 80F lower CT River Valley near VSF.
A warm front wl lift acrs our region on Monday with a ribbon of mid
lvl moisture and weak embedded s/w energy, which could produce a few
very light rain showers. Instability develops behind the warm
frontal boundary, so any convective threat would be elevated. Highs
mid 70s NEK to mid 80s southern SLV with developing south to
southwest winds.
KEY MESSAGE 2: Tuesday will be a very warm day - the warmest of the
year for most of our area. The peak of the warm air advection will
occur leading into Tuesday afternoon, with 925 mb temperatures
maxing out 20-25 deg C. This suggests some of our valley locations
could reach into the upper 80s, though just how warm we get will
depend on cloud cover and coverage/timing of showers. Our forecast
has highs in the upper 80s Tuesday for much of the Champlain Valley
and the Connecticut River Valley, and highs in the low to mid 80s
elsewhere. Dewpoints will also be ticking upwards going into
Tuesday, resulting in an increasingly muggy feel to the air. Gulf
moisture wrapping up and around the Bermuda high will bring
dewpoints to around 60 degrees by Tuesday. All in all, expecting
Tuesday to feel like full-swing summer after a seasonably cool start
to the month.
The heat and humidity will also result in increasing instability,
which will support the development of some showers with the
potential for some embedded thunderstorms. These could throw a bit
of a wrench in the temperature forecast; earlier
showers/thunderstorms may mean we underperform on high temperatures.
Will have to watch how it all works together with regards to timing,
as there isn`t a well defined front to track but rather disorganized
vort maxima rippling through the flow.
Showers and thunderstorms will become more widespread on Wednesday
as a front sinks southward through our area. Temperatures south of
the front will still be quite warm (low to mid 80s in
southern/eastern VT), while seasonably cooler conditions are
expected further north near the International Border.
The end of the work week will trend drier and cooler with high
pressure settling overhead.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Through 18Z Saturday...We started off the morning with highly
variable ceilings across the forecast area. These ceilings have
lifted to VFR levels at all TAF sites except KMSS and KRUT as of
18Z. Still observing some scattered clouds around the 1500-3000
ft level, so have included some tempo groups for the first few
hours of the TAF for brief periods of MVFR ceilings. However,
expect improving trend to continue, with all TAF sites forecast
to lift to and remain VFR from 21Z onward.
The fog forecast tonight is a little tricky with mixed
signals... increased moisture from recent rainfall but still
some winds just off the surface that will keep most areas
somewhat mixed. Thinking the 5-15 knot flow just off the surface
will limit fog development to just the sheltered valleys of
eastern Vermont. Have kept mention of fog out of all the TAFs at
this moment, but there remains a small chance of some fog
overnight tonight at KMPV, most likely between 09Z and 11Z.
Outlook...
Saturday Night: VFR. Slight chance SHRA.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. Chance SHRA.
Tuesday: VFR. Chance SHRA, Slight chance TSRA.
Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday: Mainly VFR, with areas MVFR possible. Likely SHRA,
Slight chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Taber
DISCUSSION...Taber/Duell
AVIATION...Duell
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