253
FXUS61 KALY 221056
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
656 AM EDT Sat Jun 22 2024

.SYNOPSIS...
Warm and humid weather continues today and tomorrow,
with a chance for showers and thunderstorms both days. Some
thunderstorms Sunday could be strong to severe. We briefly cool off
Monday behind a cold frontal passage, but then warm back up Tuesday
and Wednesday with a chance for additional showers and storms mid to
late week with another cold front.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
**Heat Advisory for the mid-Hudson Valley and Litchfield County,
 CT through 8PM Sunday.**

.Update...As of 6:40 AM EDT...Skies are mostly cloudy this
morning with a lot of low stratus around and some patchy fog as
well. The low clouds will likely take until closer to mid-
morning to burn off, but still expecting temperatures to rise
well into the 80s to around 90 for areas south of the warm
front. Also seeing some isolated thundershowers at this time in
the Mohawk Valley and southern ADKs ahead of a weak upper
impulse, but SPC mesoanalysis still shows very little surface-
based instability so these storms do not look to become severe,
although there is a marginal risk for severe storms this
afternoon. Overall, just minor adjustments with this update to
match current trends with more details in the previous
discussion below...

.Previous...Our region remains under zonal flow aloft with a
stalled frontal boundary draped across/just north of our cwa.
Most areas are dry right now, aside from a few thundershowers in
the Mohawk Valley and ADKs. Fog and low stratus should mix by
mid-morning. We remain under zonal flow aloft atop the upper
ridge, and multiple upper impulses will be riding along the
boundary as it lifts back north wards as a warm front. Northern
areas will likely see greater coverage of showers with embedded
rumbles of thunder through the morning, with drier conditions
south of I-90. However additional showers and storms are
expected to develop with daytime heating for areas in the warm
sector. CAPE values increase to 1000-1500 J/kg for areas south
of the warm front. Shear isn`t very impressive, but is slightly
higher than the past few days at 25 to perhaps 30 kt for the 0-6
km layer. With a similar environment to that of the past few
days, most storms will probably be of the pulse- variety, but
the increased shear may help to form some loosely organized
clusters as cold pools congeal. A couple of strong to severe
storms are possible, with the primary threat being damaging
winds as low-level lapse rates should be steep once again. North
of the warm front, instability will be lower, so while there
could be a few rumbles of thunder the probability for severe
weather is lower. Accordingly, SPC has a marginal risk for
severe weather today for areas along and south of I-90.

Any storms today could produce locally heavy rain with PWATs
remaining at 1.6 to 1.9" and cloud depths of 10-12 kft. With
flow parallel to the low-level boundary, some training and/or
backbuilding of storms is possible, especially with slow MBE
vectors. WPC has placed much of our region in a marginal risk
for excessive rainfall leading to flash flooding, which seems
appropriate given scattered nature of storms this afternoon.
Today will remain quite hot for areas south of the warm front
where highs will climb well into the 80s to low 90s. Areas north
of the warm front will remain slightly cooler with high terrain
areas topping out in the 70s with 80s for the valleys.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
**Heat Advisory for the mid-Hudson Valley and Litchfield County,
 CT through 8PM Sunday.**

Convection should die off after sunset with the loss of diurnal
heating. However, for areas from the ADKs through southern VT,
some lingering showers will remain possible overnight in the
vicinity of the warm front as it continues to lift northwards.
Some embedded rumbles of thunder are also possible with
showalter values of 0 to -2. It will remain quite warm and
muggy, with lows in the mid and upper 60s to low 70s. Patchy fog
and low stratus will once again be possible, especially for
areas that receive rain during the day today.

Sunday is shaping up to be an active weather day. A potent upper
shortwave and associated surface cyclone track from the Great
Lakes along the international border, with the surface low
deepening to around 995 mb. The warm front lifts to our north,
putting our entire region in the warm sector. A pre-frontal
trough will track across the region during the afternoon, ahead
of the main cold front which tracks through Sunday night.
Multiple rounds of showers and storms, some strong to severe,
are expected Sunday afternoon and evening...

     Despite mostly cloudy skies, CAMs suggest that we will see
SBCAPE values increase to 1500 to potentially 2000 J/kg. Shear
looks more impressive, with guidance suggesting around 30 to 35
kt winds from the southwest at 850 mb and over 40 kt winds from
the west/southwest at 500 mb. Hodographs therefore lengthen with
some low-level curvature. Now, there are questions as to just
how much we destabilize given the expected cloud cover, and the
forcing does not look overly impressive until the cold front
comes through Sunday night. Nevertheless, given the overlap of
shear and expected instability, we collaborated with SPC to
introduce a slight risk across the region Sunday, as any storms
that do develop in the warm sector could quickly become severe.
Main threat is damaging wind gusts, but isolated instances of
large hail or even a tornado can`t be ruled out given the more
impressive shear. All storms will be capable of producing
frequent lightning and heavy rain, but faster storms motions
should limit the flash flood threat. Sunday will be quite warm
and muggy, and if forecast confidence increases the heat
advisory may need to be expanded further north up the Hudson
Valley to around the Capital District.

There will likely be lingering showers and storms into Sunday
evening, but the severe threat diminishes with the loss of
daytime heating and waning instability. It remains warm and
muggy with some patchy fog ahead of the cold front, as the
front may take until 9-12z to fully clear our area and track
into central New England. However, cooler temperatures and lower
humidity are expected behind the front on Monday. We will likely
still have some showers around as the upper trough and
associated cold pool aloft move overhead, but we are not
expecting severe weather or additional hydro concerns. Showers
diminish Monday night as surface high pressure builds in from
the southwest. Monday night temps drop into the mid to upper
50s for most areas.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
The extended forecast period opens with a brief period of fair and
dry weather with high pressure building in from the Ohio Valley,
then shifting eastward over the Mid Atlantic States. The flow aloft
will be west/northwest.  Temps will run above normal but humidity
levels should not be too bad with dewpoints in the 50s to around
60F. Highs will be in the mid and upper 80s in the lower elevations
and 70s to lower 80s over the higher terrain. The sfc anticyclone
moves offshore with a return flow of more humid air beginning. A
warm front will bring a slight chance of showers or an isolated
thunderstorm over the western Adirondacks. Lows will be in the upper
50s to mid 60s.

Wed-Wed night will be the most unsettled day in the long term.  A
prefrontal sfc trough and a cold front will bring numerous showers
and a chance of thunderstorms.  Depending on the amount of
instability and sfc heating, some of the storms may be on the
stronger side.  PWATs surge above normal by a couple standard
deviations based on the latest NAEFS.  Locally heavy rain will be
possible.  Max temps will range from the mid 80s to lower 90s in the
valley areas with the best chance of lower 90s in the mid Hudson
Valley with 70s to lower/mid 80s over the hills and mtns. The
showers and thunderstorms should be diminishing by Thu morning. Lows
will be in the 50s and lower 60s north and west of the the Capital
Region and mid and upper 60s to the south and east.

Thursday through Friday...A few showers are possible with the upper
trough passage and in the wake of the cold front. A cooler and drier
air mass will be ridging in during the afternoon from the Great
Lakes Region.  Temps will be near seasonal levels with upper 70s to
lower 80s below 1000 ft in elevation and 60s to mid 70s above it on
Thu. Temps and humidity levels will be pleasant Thu night with 50s
and even some 40s over the Adirondack Park.   Zonal flow sets up
aloft to close the week with the anticyclone moving over New
England.  Fair conditions continue with seasonable temps. CPC is
predicting temperatures above normal for Days 8-14 (June 29th to
July 5th) with precipitation near to slightly above normal for
eastern NY and western New England.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Through 12Z Sunday...A stationary front is over eastern NY and
western New England this morning. Multiple disturbances will
move along the boundary in the late morning through the
afternoon producing scattered showers and thunderstorms, as it
slowly lifts northward into tonight. The showers and
thunderstorms will diminish overnight.

Widespread MVFR/IFR cigs and MVFR/VFR vsbys are impacting
KGFL/KALB/KPOU/KPSF this morning. Some LIFR conditions are
continuing at KPSF. KGFL has been mainly MVFR with cigs 1.5-3.0
kft AGL. Some showers nearby may briefly lower cigs to IFR. The
TAF sites will slowly improve to MVFR/VFR levels by the late
morning. KALB/KPSF will linger the longest at IFR levels.

Scattered showers and thunderstorms will form ahead of the
frontal boundary with weak waves moving along it close to
noontime impacting KGFL/KALB first. We used TEMPO groups to
bring showers/thunderstorms in between 16Z-22Z from north to
south, except later at KPOU in the 22Z/SAT to 02Z/SUN timeframe.
Conditions will lower to MVFR and spotty IFR in the
showers/storms. There is a secondary wave of
showers/thunderstorms in the 00Z-06Z/SUN time frame that may
occur that we placed PROB30 groups in for all the sites and we
lowered the cigs/vsbys to MVFR/IFR levels. Low stratus with some
mist and fog continues thereafter and we placed IFR level
stratus with IFR/MVFR mist the murky air mass.

The winds will be light/variable at 4 KT or less this morning.
They will be southeast to south at less than 7 KT in the
afternoon and will become light to calm tonight.

Winds will be stronger, and variable in direction in and near
any thunderstorms.

Outlook...

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

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT Sunday for CTZ001-013.
NY...Heat Advisory until 8 PM EDT Sunday for NYZ064>066.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Main
NEAR TERM...Main
SHORT TERM...Main
LONG TERM...Wasula
AVIATION...Wasula