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776
FXUS61 KBTV 130753
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
353 AM EDT Mon May 13 2024

.SYNOPSIS...
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An unsettled weather pattern will continue over the next couple
of days with several rounds of showers with embedded
thunderstorms expected. First area of showers arrives today with
a warm front, more showers anticipated tonight, followed by
numerous showers with embedded rumbles on Tuesday. The threat
for severe weather is low, along with flooding, but localized
heavy down pours are possible. Highs warm into the 60s today and
well into the 70s on Tuesday.
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&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
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As of 333 AM EDT Monday...An active near term is anticipated,
but threat for hazardous or severe weather is low attm. Crntly
mid/upper lvl clouds prevail with some areas of patchy fog/low
clouds beneath, which should dissipate around sunrise. Our next
feature is ahead on GOES-16 water vapor acrs the
central/northern Great Lakes with some lightning activity. This
s/w energy and ribbon of enhanced mid lvl moisture associated
with first warm frnt wl move from west to east acrs our cwa
btwn 15-21z today. A band of light rain showers is anticipated
as energy weakens and instability is limited acrs our cwa.
Meanwhile, additional stronger s/w energy and slightly better
elevated instability impacts our cwa btwn 03z-12z with more
showers. Best potential for an embedded rumble or two of thunder
wl be over northern NY associated with a pocket of MUCAPE of
200-400 J/kg. Given increasing instability parameters and pws
values btwn 0.75 and 1.25 by 12z Tues, localized heavy down
pours are possible in the heavier convective elements. Temps
today are mainly in the 60s with clouds and only cool back into
the 50s to near 60F tonight.

For Tuesday, a nearly stationary boundary wl be located near the
International Border, as it becomes parallel with the mid/upper
lvl flow btwn trof to the north and ridge to the south. Pw
values wl be in the 1.0 to 1.25" ahead of this boundary, with
some sfc based instability developing in the late morning into
the mid aftn hours on Tues. The degree of instability wl be
highly influenced on amount of sunshine/clearing that can occur
and sfc heating. Latest CAM guidance shows pockets of CAPE
btwn 800-1200 J/kg acrs central/southern VT, as sfc temps warm
well into the 70s, while very little instability is progged over
northern SLV/VT. NBM CAPE probs have increased by 200-300 J/kg
from previous couple of runs, highlighting the potential for
some clearing and greater instability to develop. Progged 925mb
temps are very warm south of the boundary with values btwn
18-19C, supporting highs well into the 70s to near 80F, while
readings are only in the mid 60s near the border. This
differential/instability gradient should help to enhance
showers/thunderstorm activity btwn noon and 5 pm acrs our region
on Tues. The probability of svr or flash flooding is <10% attm,
but feel some stronger cells are possible with frequent
lighting, brief heavy down pours, and localized gusty winds to
40 to 45 mph. Shear is rather marginal for svr on Tues with
strongest core of 850 to 700mb winds displaced over southern
Canada associated with trof. Given small storm vectors the
potential for training of convection wl need to be watched, but
feel just enough southeast drift should occur to prevent issues.
Should be plenty of activity to monitor on radar Tues aftn acrs
our cwa.
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&&

.SHORT TERM /WEDNESDAY/...
As of 341 PM EDT Sunday...North stream and southern stream troughing
will slowly drag a boundary through the North Country Tuesdays.
Forcing is not great, but temperatures in broader valleys will
likely warm into the upper 60s to mid 70s with the cooler
temperature towards the Canadian border. This marginal surface
instability and steepening lapse rates aloft will support some
isolated thunderstorm chances along and south of the boundary mainly
Tuesday afternoon through midnight. Overnight, upper troughing picks
up speed ushering the surface boundary through Northern New York
into southern Vermont. Total rainfall amounts continue to be
expected in the 0.5-0.75" range in general; higher end totals in
areas of convection could exceed 1". Without a strong thermal
contrast, temperature will stay mild through Wednesday with highs in
the mid/upper 60s, shower chances diminishing, and winds turning out
of the north.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 341 PM EDT Sunday...Main feature Wednesday night through
Thursday night continues to be relative ridging with maximum
amplitude Thursday. Model depiction of the longwave amplitude is low
across eastern Canada/US favoring continued high clouds and steadily
warming temperatures during daytime cloud breaks. Daily highs in
upper 60s to low 70 are probable to persist into the weekend. Next
precipitation chances return by late Friday through the weekend with
guidance showing the next trough passing south, but in the vicinity
of the North Country.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
Through 06Z Tuesday...Aviation challenge this morning will be
areal coverage of fog/low clouds and potential impacts at our
taf sites. Crntly mostly VFR with exception of LIFR at SLK in
fog. Based on rainfall yesterday and clearing of mid clouds,
thinking IFR/LIFR fog is likely to persist at SLK thru 10z with
improvement as more clouds and winds increase. Also, thinking
brief intervals of IFR fog/br and low clouds is possible
(30-40%) at RUT/MPV btwn 07-10z. Have utilized tempo group to
highlight this potential prior to sunrise, while VFR prevails
at our other sites. Any fog/low clouds will become VFR
conditions by 12z and persist most of the day, before lower cigs
to MVFR occurs over northern NY sites by 00z, along with
scattered showers. South winds develop by 15z at 5 to 10 knots
with localized gusts 15 to 20 knots possible in the CPV.

Outlook...

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

&&

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

&&

$$
SYNOPSIS...Taber
NEAR TERM...Taber
SHORT TERM...Boyd
LONG TERM...Boyd
AVIATION...Taber