375
FXUS61 KBTV 050937
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
537 AM EDT Wed Jun 5 2024

.SYNOPSIS...
A very warm day is expected with a few showers and thunderstorms
possible, but areal coverage of precipitation will be less 30
percent. High temperatures will be in the 80s with a few warmer
valley locations near 90 again today. Occasional rain showers with
embedded rumbles of thunder are likely for Thursday, along with
localized heavy down pours. Cooler and unsettled weather prevails
into the upcoming weekend.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
As of 536 AM EDT Wednesday...Quick update to increase pops into
the 15-30% range from near PBG to BTV this morning as radar is
showing widely scattered activity developing along mid lvl
moisture/instability axis. Also, had to tweak hrly temps a bit,
as BTV is struggling to drop below 70F this morning. Rest of
fcst in good shape.

Previous discussion below:
Well our stretch of outstanding North Country Chamber of
Commerce weather will be coming to an end by Thursday, as a
widespread wetting rainfall is likely, along with cooler temps.
But first today we are dealing with the potential for isolated
to widely scattered showers/storms, but recent modeling trends
have throttled back on areal coverage of precip. Water vapor
conts to show deep dry layer in place, while mid/upper lvl ridge
axis is still to our west. Have noted a weak lobe of slightly
better moisture and weak embedded s/w energy from an axis north
of the Ottawa Valley into portions of SNE this morning, which wl
help in the development of our isolated/widely scattered
activity today. Timing of convection is a bit tricky, as
sounding data shows best sfc based CAPE values of 800- 1400 J/kg
late this morning/early aftn, before drier air aloft again
mixes toward the sfc and drops our dwpts back into the l/m 50s.
This scenario produces less instability during peak heating and
limits the overall areal coverage of precip. Based on this and
the latest RAP/HRRR and NAM 3KM composite reflectivity progs
have throttled back pops into the 15-30% range, with highest
values over the Dacks and portions of the NEK of VT. The risk of
flash flooding is very low today, therefore WPC has removed the
marginal threat. Progged 925mb temps are btwn 21-23C, which are
very similar to yesterday when we saw BTV reach 90F, so
thinking 90F again today at BTV, with 85F at MPV and 82F at SLK.
Once again the difference btwn the 10th and 90th percentile for
high temps is 89-91 off the latest NBM at BTV. High confidence
for temp fcst.

Tonight bl layer dwpts increase quickly around sunset with values in
the upper 50s to mid 60s as southerly winds prevail ahead of our
next synoptic scale system. A muggier night is anticipated, combined
with the high temps today has placed portions of our valley
locations in moderate heat risk with pockets of major in the SLV for
Day 1. Given the higher dwpts and lingering instability a few rogue
showers/isolated rumbles are possible overnight, similar to this
morning, but areal coverage <10%. Lows wl be very mild with readings
in the upper 50s to upper 60s/near 70F.

Thursday...Deep and closed cyclonic circulation over the northern
Great Lakes approaches our cwa with associated height falls and
favorable upper lvl divergence with warm/occlusion type boundary
lifting from sw to ne. This boundary wl be associated with strong
deep layer moisture advection, as pw values surge btwn 1.75 and
1.90", which is 95th percentile for early June. In addition, warm
cloud layer depths increase btwn 10-11.5kft by 18z Thurs as initial
s/w energy is lifting acrs our cwa. Additional s/w energy with
mid/upper lvl trof approach our cwa btwn 18-00z Thurs with
tall/skinny CAPE profiles per sounding data, supporting localized
heavy rainfall. HREF show 40-60% probs of 2" of qpf acrs portions of
the northern Dacks into northern/central VT with 15-25% probs of up
to 3" possible in a few localized areas. WPC has maintained a
marginal risk of exceeding flash flood guidance, which given recent
dry spell, relatively high flash flood guidance, and storm motions
of 10 to 15 mph looks reasonable attm. Given the dry antecedent
conditions and above ingredients feel probability of flash flooding
is <5% at any given location acrs our cwa on Thurs. Highs wl be
cooler with readings in the mid 70s to lower 80s, but with higher
dwpts it wl feel a bit muggy.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 421 AM EDT Wednesday...The frontal boundary will exit the
region Thursday night, marking the start of a more unsettled weather
pattern. The steadiest rainfall will come to an end Thursday night
as the best moisture moves to our east, with a break in
precipitation before more showers develop during the day Friday.
Current QPF amounts range between 0.5 to 1.25 inches, with some
higher amounts possible across the high terrain and within any
heavier showers. Showers during the day on Friday do not look to be
particularly heavy given the better moisture will be out of the
region, with a closed low over the Great Lakes starting to move into
the region. Overnight low temperatures Thursday night will be on the
mild side, in the 50s and low 60s. Temperatures during the day on
Friday will be cooler in comparison to the last few days, with highs
climbing into the 70s, along with plentiful cloud cover.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 421 AM EDT Wednesday...A closed upper low centered over the
Great Lakes will gradually move overhead towards the weekend,
bringing cool and unsettled weather to the region. While there are
continued chances of showers and possible thunder over the next
several days, no day is expected to be a complete washout and the
showers will be more hit or miss. The greatest coverage of showers
can be expected during the afternoon as diurnal heating and cold air
aloft allow for greater instability, with shower activity dwindling
overnight. Daytime high temperatures will generally be in the 60s
and 70s, with seasonable overnight lows in the upper 40s and 50s.
The upper low will gradually move eastward, potentially bringing a
reprieve from the showery weather by midweek, although there is
still some uncertainty regarding the track and evolution of the low
and how quickly it departs.

&&

.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
Through 06Z Thursday...Early morning radar is showing an
isolated thunderstorm across central/eastern Addison County,
which will not impact our TAF sites. Additional scattered
showers and thunderstorms are expected between 15Z and 21Z today
and have placed VCSH in TAFs to cover potential. Also, there is
a small probability of localized fog at SLK this morning between
07-10z, just prior to sunrise as boundary layer moisture has
increased with earlier convection nearby. However, have noted
southwest winds of 15 to 20 knots developing between 200-400 AGL
toward sunrise, which may provide just enough mixing to limit
potential. Otherwise, VFR conditions prevail for the next 12 to
24 hours, exception brief MVFR cigs/vis in any convective
showers today. South/southwest winds 5 to 10 knots develops by
15z.

Outlook...

Thursday: Mainly VFR, with local IFR possible. Definite SHRA,
Slight chance TSRA.
Thursday Night: Mainly VFR, with local IFR possible. Chance SHRA.
Friday: Mainly VFR, with local MVFR possible. Likely SHRA, Slight
chance TSRA.
Friday Night: Mainly VFR, with local MVFR possible. Chance SHRA.
Saturday: Mainly MVFR, with local VFR possible. Likely SHRA,
Slight chance TSRA.
Saturday Night: Mainly MVFR, with local IFR possible. Chance
SHRA, Slight chance TSRA.
Sunday: Mainly MVFR, with areas VFR possible. Likely SHRA, Slight
chance TSRA.

&&

.CLIMATE...
Based on the current forecast, daily records are possible over
the next three days at some climate sites.

Record high maximum temperatures are possible today, primarily
at Massena and Montpelier. A record high minimum temperature may
occur at Plattsburgh for those nights. Record daily
precipitation is possible at Massena on Thursday.


Current Record High Temperatures:

June 5:
KMPV: 85/2021
KMSS: 88/1974


Current Record High Minimum Temperatures:

June 5:
KPBG: 65/1963

June 6:
KPBG: 67/1973


Current Record Precipitation:

June 6:
KMSS: 1.09/1953

&&

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

&&

$$
SYNOPSIS...Taber
NEAR TERM...Taber
SHORT TERM...Kremer
LONG TERM...Kremer
AVIATION...Taber
CLIMATE...Kutikoff