007
FXUS61 KALY 210746
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
346 AM EDT Tue May 21 2024

.SYNOPSIS...
Today and tomorrow will both be hot with isolated to
scattered afternoon and evening thunderstorms. A cold frontal
passage Thursday will bring another round of showers and storms,
especially for areas south and east of Albany. Behind the front,
temperatures trend cooler, although we may have another round of
showers to deal with over the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 3:50 AM EDT...Our region is located beneath an upper
ridge, with surface high pressure off to the east over the
western Atlantic. Flow aloft has become more zonal as the ridge
folds over on itself, and this has allowed some thin, high
cirrus associated with upstream convection to spill into our
region. Some low stratus has also developed in southeastern
Litchfield County, and this should continue slowly expanding
north and west through around daybreak thanks to low-level
southerly flow. Since the clouds have remained relatively thin,
we have seen favorable radiative cooling conditions outside of
the north to south oriented valleys, with some patchy fog
development. Some additional patchy fog is possible through
around 12z this morning as temperatures continue to cool through
the next few hours. Overnight lows will range from low 60s in
the high terrain to low 60s for the valleys.

Today will be the warmest day so far for most places, as we will
remain under the influence of the upper ridge. Highs could
approach 90F in the valleys, but it does not look like we will
reach heat advisory criteria. Later this morning through this
afternoon, convection from the Great Lakes associated with a
convectively enhanced upper shortwave and attendant surface low
will track to our north around the periphery of the upper ridge.
The upper impulse and any outflow boundaries from the convection
to our north will likely provide enough forcing for ascent for a
few showers/thunderstorms to develop this afternoon, mainly for
areas along and north of I-90. Deep-layer shear is unimpressive
at 25kt or less, so widespread severe weather is not expected.
That being said, SBCAPE values look to reach 1500-2000 J/kg with
the warm airmass in place and mid-level lapse rates of around
6C/km. Steep low-level lapse rates and mid-level dry air in
place also suggest that a few storms could have some marginally
severe hail and/or gusty winds. The best chance of any stronger
storms is across the ADKs and upper Hudson Valley. SPC has
placed this region in a marginal risk for severe weather, which
makes sense given the aforementioned setup.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
Tonight, any lingering showers or storms should dissipate within
a few hours of sunset with the loss of diurnal heating and
decreasing instability. Most of the night will be fairly dry
with partly cloudy skies. Any areas that see rain during the day
today could see patchy fog develop tonight with winds expected
to be light once again. We may also see some low stratus again
towards the I-84 corridor, similar to Monday night. Lows will be
a few degrees warmer than the previous night, mainly in the
upper 50s to mid 60s.

Wednesday, potent upper and surface low pressure system will be
tracking into the western Great Lakes region well to our west.
Most of the day will be dry with partly to mostly clear skies as
our region remains under the influence of upper ridging. THis
will help temperatures rise well into the 80s to low 90s for
many valley areas, so it should be even a couple degrees warmer
than Tuesday. Heat indices could get into the low 90s, but
should fall a few degrees short of heat advisory criteria.

Late Wednesday afternoon and evening, a pre-frontal trough will
approach from the west, potentially leading to development of
more showers and thunderstorms. Similar to Tuesday, CAPE values
will be quite impressive and there will be steep low-level
lapse rates and mid-level dry air that are suggestive of an
environment that could support some gusty winds and hail with
any storms, but the lack of shear should keep the severe threat
on the low side. SPC has placed our western Mohawk Valley and
ADK areas in a marginal risk for severe weather again,
Wednesday. Storms could make it as far east as the Hudson Valley
Wednesday evening or early Wednesday night, but they will be
weakening at this point with the loss of daytime heating. There
could be a few lingering showers or a non-severe thunderstorm
Wednesday night, but overall most places should dry out
especially after midnight. Wednesday night will be quite mild,
with lows in the 60s for most areas.

Thursday, they system`s cold front will finally track through
our region. The exact timing of the front in relation to peak
daytime heating will determine how widespread showers and storms
become. Currently, it looks like the cold front will pass
through our western areas Thursday morning, which will limit the
coverage and intensity of any thunderstorms. For areas south and
east of Albany, the cold frontal passage will likely occur
during the afternoon, so there should be more instability to
work with. Shear will also be more impressive than the previous
few days with 30 to 40 kt winds at 500 mb. Low-level forcing is
not overly strong, but height falls aloft and the approaching
right entrance region of the upper jet should provide additional
lift. Therefore, areas south and east of Albany could see some
stronger storms Thursday if the current forecast holds. SPC
accordingly has placed portions of the Mid Hudson Valley and
southwestern New England in a marginal risk for severe weather.
Thursday will be cooler for areas north and west of Albany with
highs in the 70s to low 80s, but temperatures out ahead of the
front will likely climb into the mid to upper 80s along the I-84
corridor.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Showers and thunderstorms will come to an end Thursday evening as
the cold front crosses the region and stalls over the mid-Atlantic
states. This will result in decreasing clouds Thursday night and
mostly sunny and less humid weather on Friday with weak high
pressure overhead. Highs on Friday will reach the mid-70s to mid-
80s.

The remainder of the forecast period will consist of a series of
upper-level shortwaves crossing the region, which will result in
additional chances for showers and possible thunderstorms. Run-to-
run consistency of these shortwaves is poor resulting in lower
confidence in timing. Latest trends suggest the better shower
chances are on Saturday and either Monday or Tuesday of next week
(pending the arrival of the next shortwave) with Sunday trending
drier (in-between shortwaves). Will cap the extended with chance
pops until confidence in timing of each shortwave increases. Highs
on most days will be in the 70s with some mid to upper 60s at times
across the higher elevations.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
Through 06z/Wed...Cirrus clouds will continue to stream across the
region through the overnight. This leads to some uncertainty as to
how well fog will be able to form. Based on latest trends,
maintained fog potential at the climatological favored sites of
KGFL/KPSF due to calm winds and low dewpoint depressions and removed
mentions from KALB/KPOU due to larger dewpoint depressions and a
lingering breeze. Brief IFR vsbys or lower will be possible with any
patches of fog that form. Outside of fog, VFR conditions will
prevail.

Any fog will lift early Tuesday morning with VFR conditions
remaining in place with developing fair weather cumulus around 5 kft
and high cirrus. An upper level disturbance passing by to the north
could develop some isolated to scattered showers and thunderstorms
during the afternoon hours from KALB/KPSF north to KGFL. Have
included VCSH and PROB30 for these sites. Any activity should stay
north of KPOU.

Shower activity may linger into Tuesday evening at KGFL but end
elsewhere with some patchy mid and high clouds around for Tuesday
night. Where rain does fall and enough clearing occurs, fog could
quickly develop after sunset.

Wind will be calm or light out of the south-southeast throughout the
overnight (except south-southeasterly at 5-10 kt at KALB) then
become south to southwesterly at 5-10 kt on Tuesday. Wind will
decrease to 5 kt or less Tuesday night (except 5-10 kt at KALB).

Outlook...

Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Low Operational Impact. Slight Chance of SHRA.
Saturday Night: Low Operational Impact. Slight Chance of SHRA.
Sunday: Low Operational Impact. Slight Chance of SHRA.

&&

.CLIMATE...
Record High Temperature for May 21:

Albany: 92 in 1941
Glens Falls: 93 in 1921
Poughkeepsie: 95 in 1996

Record High Temperature for May 22:

Albany: 97 in 1911
Glens Falls: 98 in 1911
Poughkeepsie: 98 in 1941

&&

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

&&

$$

SYNOPSIS...Main
NEAR TERM...Main
SHORT TERM...Main
LONG TERM...Rathbun
AVIATION...Rathbun
CLIMATE...Speciale