691
FXUS61 KALY 042356
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
756 PM EDT Thu Jul 4 2024

.SYNOPSIS...
A weak frontal boundary will keep the threat for a shower or
thunderstorm tonight into Friday, with continued warm and muggy
conditions. Hot and humid conditions are expected on Saturday
with more thunderstorms around once again.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...

As of 7pm...A scattered to broken mid to upper cloud deck
will continue to blanket most of eastern NY and western New
England this evening which will keep temperatures warm in the
upper 70s to low 80s for Independence Day festivities. Given
elevated dew points in the upper 60s, it is also quite muggy.

There are areas of slow moving thunderstorms in the Catskills
in WFO BGM`s region producing heavy rain. While the CAMs are
not handling the convection very well, the HRRR and the NAM
suggest these storms will weaken as they shift into the eastern
Catskills but still produce some periods of showers and rumbles
of thunder thanks to 500-1000 J/kg of surface based CAPE. Storms
should weaken further as they leave the elevations of the
Catskills and we continue to lose daytime heating but some
showers may still spill into the mid-Hudson Valley through
Midnight. We therefore continue to message slight to chance POPs
in the eastern Catskills and mid-Hudson Valley through Midnight.
The rest of the region should remain dry yet warm/muggy for
evening fireworks.

We turn mainly dry after Midnight yet continued warm/muggy
thanks to ongoing cloud coverage. The diffuse warm front should
lift northward towards the pre-dawn hours but renewed shower
activity should hold off until after sunrise. We maintained
slight chance POPs south of I-90 through 12 UTC to account for
any isolated shower in the vicinity of the thermal/dew point boundary
but we do not expect widespread precipitation.

Previous discussion...More organized scattered showers and
isolated thunderstorms in NE PA will track into the eastern
Catskills, mid Hudson Valley and NW CT, perhaps brushing the
southern Berkshires tonight. Outside of the showers and storms,
convective debris clouds, and mid and high clouds will be over
our region, preventing ideal radiational cooling conditions, and
low level humidity will increase slowly as well. So,
temperatures will fall to lows in the 60s to around 70.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Some lingering isolated to scattered showers and storms are
possible in the mid Hudson Valley and NW CT Friday morning, and
a mix of clouds and sun is expected outside of any morning
showers and storms, to help temperatures and the humidity to
rise through the day. Additional scattered showers and
thunderstorms Friday afternoon with the instability and diffuse
boundary still in our region as a low level focus. Highs Friday
well in the 80s to near 90, with around 80 to lower 80s higher
terrain. The increase in low level humidity will cause heat
indices to rise to the mid 90s in the mid Hudson Valley to
perhaps the Capital Region but very brief and some uncertainty
about heat indices reaching 95 or higher for two hours or more,
so no Heat Advisories.

Weak upper impulse tracks north of our region Friday night,
supporting a little bit of an expansion of the showers and
thunderstorms over our region. Instability will be marginal and
shear will increase but still, the low level forcing will be
weak, and not enough of a severe weather or flood threat to
highlight. So, showers likely with scattered thunderstorms
Friday night, that are timed to exit around or after daybreak
Saturday. Some intervals of clouds and sun later Saturday
morning and early afternoon before additional more isolated to
scattered showers and storms develop along the leading edge of
weak low level colder and drier air. The intervals of sun and
clouds will help temperatures to get well into the 80s, with
around 80 higher terrain.

Any lingering scattered showers and storms exit western New
England Saturday evening and cloud cover should decrease through
the night. Sunday is expected to be dry and partly to mostly
sunny with the weak cold front just to the south. Highs well
into the 780s to near 90 with upper 70s to lower 80s higher
terrain, and slightly less humid.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Dry weather will continue Monday with highs in the mid 80s to
around 90 and around 80 to lower 80s higher terrain. The weak
low level boundary to our south will begin to return north
Tuesday as upper energy in the Great Lakes approaches.
Increasing clouds and showers and thunderstorms are expected
Tuesday with highs in the lower to mid 80s and upper 70s to
around 80 higher terrain.

The low level, nearly stationary boundary over our region will
be the focus for showers and thunderstorms Wednesday and
Thursday as weak upper energy tracks along the U.S./Canada
border. Highs Wednesday and Thursday in the lower to mid 80s
with 70s higher terrain.

The weak upper dynamics and shear suggest limited potential for
severe thunderstorms or a flood threat but the nearly
stationary nature of the low level boundary and prolonged
chances for showers and thunderstorms suggests at least keeping
an eye on heavy rain potential.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...

Mainly expecting VFR conditions through tonight under SCT to
BKN mid and upper level ceilings. A cluster of showers and
storms in the Catskills will continue to dissipate as it heads
eastward this evening but we included a TEMPO group for MVFR
visibility at POU through 04 UTC/05 to account for any brief
shower that makes it to the terminal. After 04 UTC, expecting
mainly dry conditions at all the terminals but given the high
humidity and low-level moisture in place, some patchy fog may
develop at GFL mainly 07 - 11 UTC. Maintained a TEMPO group
there for MVFR visibility for this reason. The remaining
terminals should be VFR given the lack of shower activity
expected and cloud coverage but will continue to monitor for fog
formation through the pre-dawn hours.

Any fog will burn off by 11-12 UTC and as our diffuse dew point
boundary/warm front lifts northward, high resolution guidance
suggests isolated to widely scattered showers and isolated
thunderstorms develop around POU and PSF first by 13 - 15 UTC
before developing near ALB by 15-16 UTC. As daytime heating
increases midday into the afternoon, thunderstorms have a higher
chance of developing. Including a PROB30 group at PSF, POU, and
ALB for potential scattered showers and thunderstorms through 18
and 19 UTC resulting in MVFR visibility and low end VFR
ceilings. Chances for scattered showers and thunderstorms continue
into the afternoon after our PROB30 group through the end of the
TAF period but given low confidence on the exact placement and
timing of any additional showers/storms, did not include
additional shower/storms after our PROB30 group ends in the
latest TAF

Southerly winds around 5-10kts turn light and variable after
02-03 UTC tonight. Southerly winds around 3-5kts return by 14-16
UTC but remain light.

Outlook...

Friday Night: High Operational Impact. Likely SHRA...TSRA.
Saturday: Moderate Operational Impact. Chance of SHRA...TSRA.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
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.

&&

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

&&

$$

SYNOPSIS...NAS
NEAR TERM...NAS/Speciale
SHORT TERM...NAS
LONG TERM...NAS
AVIATION...Picard/Speciale