157
FXUS61 KBTV 040800
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
400 AM EDT Tue Jun 4 2024

.SYNOPSIS...
Another very warm day with just a few isolated mountain showers are
possible this afternoon and evening. High temperatures will climb
back into the 80s with a few valley locations approaching 90
degrees. A slightly better chance for scattered showers and
thunderstorms are expected for Wednesday with temperatures in the
80s and slightly higher humidity. A cooler and unsettled weather
pattern develops for Thursday and continues into the upcoming
weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
As of 356 AM EDT Tuesday...GOES-16 mid level water vapor
imagery continues to show mid/upper lvl ridge axis directly
overhead with associated very dry air aloft, while some high lvl
moisture is advancing from the northern Great Lakes toward our
fa this morning. The forecast challenge today wl be potential
for a few isolated showers/storms to develop acrs the higher
trrn btwn 3 PM and 8 PM. The large scale synoptic forcing is
very weak with ridge overhead and moisture is rather minimal, as
soundings continue to show drier air aloft mixing toward the
sfc this aftn and dwpts dropping into the upper 40s to lower
50s. This large temp/dwpt spread limits the sfc based CAPE
values thru 21z today in the 250-500 J/kg. However, toward
evening bl dpwts are expected to increase from weak llvl
moisture advection and less mixing from aloft, creating pockets
of sfc based CAPE values in the 500-800 J/kg. At the same time a
very subtle s/w wl try to break through ridge and combined with
some trrn enhanced convergence to produce a slight 10-20% of an
isolated shower or two with a few rumbles. Highest probability
based on trrn wl be High Peaks of Essex County and along the
Spine of the Green Mountains, where weak backdoor frnt wl help
with convergence. Once again areal coverage wl be limited and
based on expectation I would not cancel any outdoor activities,
just keep an eye to the sky. I saw BTV hit 86F yesterday and
progged 925mb temps are btwn 21-22C, which supports 89F today at
BTV and 85F at MPV and 82F at SLK. NBM 10th percentile for high
temp at BTV is 88F, while the 75th percentile is 91F,
indicating the relatively small spread and high confidence in
temps this aftn. For tonight any lingering showers acrs the trrn
should dissipate by 02Z, but sfc dwpts wl be warmer than
previous nights, so anticipate a tad more humidity and maybe
some localized patchy valley fog. Lows in the l/m 50s SLK/NEK to
l/m 60s CPV/SLV.

On Weds, instability and moisture parameters are slightly better,
along with another weak s/w crossing our cwa in the aftn/evening
hours. Latest CAM guidance indicates 2m dwpts climbing into the
upper 50s to lower 60s on Weds, creating CAPE values in the 800-1500
J/kg range, while deep layer shear is <20 knots. Given the weak
flow, storm motions wl be 15 knots or less, so the potential for
slow moving convection acrs the higher trrn wl need to be watched
closely, especially as pw values climb above 1.25". Did note WPC ERO
for day 2 has our cwa in marginal risk, which given recent dry spell
and latest FFG seems a bit aggressive. Did coordinate with them, but
their concern was that several members of the HREF family (ARW and
FV3) were highlighting the dacks for potential localized rainfall in
the 2 to 3 inch range, which approaches 3 hr FFG. For now would like
to see better CAM consensus, especially given recent dry spell
before gaining confidence in any flash flood potential.
Otherwise, I have continued with chc pops btwn 16z-00z Weds for
most of the cwa, with highest values acrs the trrn. Temps are
similar to the previous couple of days with highs mostly btwn
82-88F.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 356 AM EDT Tuesday...A frontal boundary moving across the
region will bring more widespread precipitation and a pattern change
after a long stretch of drier weather. Precipitable water values
will be near 1.5 inches, which is near the 90th percentile of SPC
sounding climatology for Albany NY, which supports the potential for
some locally heavy rainfall. WPC has the region in a Marginal
Excessive Rainfall Outlook (ERO), but given the dry antecedent
conditions no widespread hydrologic concerns are expected. Current
QPF amounts range between 0.5 to 1.0, with some higher amounts
possible across the high terrain and within any thunderstorms. The
fairly progressive nature of the boundary will also help mitigate
any potential impacts. Temperatures during the day on Thursday will
be in the 70s to near 80, although it will feel quite humid with
dewpoints in the low to mid 60s. Overnight low temperatures Thursday
night will be on the warm side, in the 50s to low 60s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 356 AM EDT Tuesday...A closed upper low centered over the Great
Lakes will continue to meander across the region, bringing a period
of showery and cooler weather through the beginning of next week.
Embedded shortwaves will pinwheel around the low, bringing daily
chances for showers, although no day looks like a complete washout.
Daytime high temperatures will generally be in the 70s, several
degrees cooler than the last few days. Overnight lows will generally
be in the upper 40s to upper 50s, which is near normal for this time
of year.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...Surface high pressure is providing our
taf sites with mostly clear skies and light winds this morning.
Have noted the AvnFPS ceiling/vis climo trend tool is indicating
a non zero potential for IFR or lower in br/fog at SLK btwn
08-10z this morning with probabilities of 20-25% based on crnt
obs. Have placed VCFG at 08Z and may place last minute tempo
group for br btwn 08-10z to cover potential. Otherwise, VFR
conditions prevail at rest of the sites for the next 12 to 24
hours with some isolated showers possible this aftn btwn
20z-24z. Light trrn driven winds will result in southeast winds
at RUT/PBG and northeast at MSS with light and variable under 5
knots elsewhere.

Outlook...

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

&&

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

&&

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