390
FXUS61 KALY 070248
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1048 PM EDT Sat Jul 6 2024

.SYNOPSIS...
Widely scattered showers and thunderstorms will end this
evening, followed by dry conditions tonight into Sunday.
Humidity levels will be slightly lower on Sunday, but very warm
temperatures will persist. Above normal temperatures will
continue through early next week, with humid conditions
returning. The next chance of showers and thunderstorms arrives
Tuesday, as a frontal system approaches form the west.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
.UPDATE...As of 1030 PM EDT, weak cold front was now settling
south and east across the southern Berkshires, southern Taconics
and northern Litchfield County extending into the eastern
Catskills. Latest SPC Mesoanalysis indicates decreasing ML
CAPES, with 500-1000 J/kg across the mid Hudson Valley and NW
CT, and less than 500 J/kg to the north and west.

Line of showers/thunderstorms with gusty winds tracked across
Berkshire County within the last hour, and are still lingering
across far SE Berkshire County.

Based on mesoanalysis, will keep PoPs for areas remaining
southeast of the front/dewpoint boundary across Litchfield
County extending into the mid Hudson Valley, but only in the
slight chance to low chance range due to expected limited
coverage.

Additional isolated showers across south central NYS were
tracking east but showing signs of weakening. Should these
survive, some additional showers could reach the eastern
Catskills and mid Hudson Valley later tonight.

Otherwise, gradual decrease in humidity levels is expected from
NW to SE overnight, most noticeable for areas along and north
of I-90, and west of I-87.

PREVIOUS [315 PM EDT]...A weak cool front will continue to
slowly move eastward across the area into this evening, with an
upper level short wave tracking east across the lower Great
Lakes. This will continue to result in just enough forcing for
widely scattered showers/T-storms into early evening.
Environment continues to support an threat of isolated severe
storms producing damaging wind gusts. SPC Mesoanalysis
indicating 1000-1500 J/Kg MLCAPE and 50-60 kt of effective
shear. The Storm Prediction has a Marginal Risk (level 1 of 5)
of severe storms. Poor mid level lapse rates and moist
environment with high freezing levels mitigate hail threat, but
locally heavy rainfall will occur with isolated flash flooding
possible where any persistent or repeated downpours occur. The
heat risk lowers after sunset, with humidity levels dropping
slightly in wake of the front. Low temperatures should range
from the upper 50s in the Adirondacks to upper 60s in the mid
Hudson Valley. Patchy fog will may occur, especially for
locations that receive rainfall today.

Sunday looks to be a quiet day with a broad SW flow aloft and
surface high pressure building in from the west. Subsidence
should halt any convective development, with just some fair
weather cumulus clouds around. A warm air mass will be in place
with 850 mb temperature anomalies around +1 STDEV, so with
sufficient sunshine highs should reach the mid to upper 80s in
lower elevations, with cooler upper 70s to lower 80s in the
higher terrain. Humidity levels will be lower than recent days,
with dewpoints mainly in the lower to mid 60s.

Surface high pressure will be positioned over the region Sun
night, with flat ridging aloft. It should be mostly clear with
lows ranging from mid 50s in the Adirondacks to mid 60s in the
Hudson Valley.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Monday should be another rain-free day with surface high
pressure in place and flat ridging aloft. Tempertures will be
slightly warmer as 850 mb temperature anomalies rise to a solid
+1 to +2 STDEV. Humidity levels will also be creeping up into
the upper 60s to near 70, so max heat indices may reach or
slightly exceed 95F in the mid Hudson Valley. A Heat Advisory
may eventually be needed. Actual highs look to be in the lower
90s in the lower elevations. Dry, but warm/humid conditions
expected Mon night with lows in the 60s to around 70.

The next chance of showers/T-storms arrives Tue as a frontal
system and upper level trough approach from the Great Lakes.
There are timing differences in the guidance, so it is unclear
when convection will initiate yet. Some guidance has the upper
trough lagging farther back to the west which delays showers and
storms until later in the day into evening, which is more in
line with NBM favoring likely PoPs during this time. Depending
on timing and eventual instability/shear parameters, there could
be some stronger storms. Also locally heavy rainfall may occur
due to anomalously high PWATs (increasing to +1 to +2 STDEV).
Prior to convection developing, the combination of temperatures
in the lower 90s and dewpoints in the lower 70s could yield max
heat indices the mid/upper 90s in valley locations.

Scattered to numerous showers and T-storms expected to persist
into Tue night depending on the timing of the upper level trough
moving in. It will remain warm and humid with lows in the 60s
to around 70.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Latest guidance indicating the aforementioned front may stall
somewhere across the southern part of the area on Wed, so will
need to maintain a chance of showers and T-storms. Temperatures
will be somewhat cooler, especially north of the front, but
still slightly above normal with mid to upper 80s in lower
elevations.

Forecast confidence then decreases considerably in the Thu to
Sat timeframe. The main question is where the remnant
circulation of post-tropical cyclone Beryl ends up going, as it
potentially interacts with the front in the Northeast. Some
guidance has it tracking NE across the Tenn/Ohio Valley regions
into Thu, then into the lower Great Lakes Thu night into Fri.
Depending on the track, this could bring widespread and
potentially heavy rainfall given its tropical origin. Will
continue to monitor trends and mention mainly chance PoPs for
now until forecast confidence increases.

Slightly above normal temperatures and relatively humid
conditions should persist through the long term period, with
above normal temperatures continuing to be favored further out
in the 8-14 day outlook from the Climate Prediction Center.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Weak cold front was tracking south/east across the TAF sites
this evening, and now approaching the mid Hudson Valley north of
KPOU. Thus far, showers/storms have only affected KPSF with
brief periods of IFR conditions and gusty winds. Only remaining
threat of showers/thunderstorms will be at KPOU, but overall
chances remain low overall through 08Z/Sun.

Otherwise, mainly VFR conditions are expected through Sunday.
However, some patchy ground fog may develop at KPSF and possibly
KGFL, especially between 07Z-11Z/Sun. This could result in brief
periods of MVFR/IFR Vsbys.

Winds will be light/variable through daybreak, then trend into
the west/northwest at 5-10 KT by mid morning and continue
through Sunday afternoon.

Outlook...

Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Tuesday Night: Moderate Operational Impact. Likely SHRA...TSRA.
Wednesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

$$

SYNOPSIS...JPV
NEAR TERM...KL/JPV
SHORT TERM...JPV
LONG TERM...JPV
AVIATION...KL