818
FXUS61 KBTV 051819
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
219 PM 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 219 PM EDT Wednesday...Some further refinement to shower
and thunderstorm chances was made with the early afternoon
update. As expected, our region generally has the best
instability relative to areas to our north and south, with 1500
to 2000 J/kg surface-based CAPE analyzed at 1 PM for most
locations. Thunderstorms have developed early this afternoon in
the northernmost Adirondacks where mixed-layer CAPE is the
greatest. They have been pulsing up and down quickly, and would
expect that to continue for the next couple hours before
trending towards just showers. Meanwhile, in the Northeast
Kingdom, where skies have been mostly clear and the morning
convection avoided, we may see thunderstorm development later
this afternoon. Also trimmed high temperatures slightly in the
swath that saw cloudiness linger into midday, but no big changes
needed.

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 WEDNESDAY/...
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 /18Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Thursday...Isolated to scattered showers capable of
pulsing up to brief thunderstorms will continue through about
00Z, with greatest chances of being in the vicinity of SLK and
PBG, slightly less near EFK. Shower activity will wind down
after that time, with more widespread, but less heavy,
precipitation arriving from the west in the 12Z to 18Z window.
There is about a 50% chance of MVFR conditions at times
associated with these showers. Otherwise, VFR conditions should
prevail through the period. Winds will remain 10 knots or less,
generally from the south or southwest trending southeasterly,
or easterly at MSS, after 06Z.

Outlook...

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

&&

.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. A record high minimum temperature may occur at
Plattsburgh. Record daily precipitation is possible at Massena
on Thursday.


Current Record High Temperatures:

June 5:
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...Kutikoff/Taber
SHORT TERM...Kremer
LONG TERM...Kremer
AVIATION...Kutikoff/Taber
CLIMATE...Kutikoff