568
FXUS61 KALY 221047
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
647 AM EDT Fri Aug 22 2025

.SYNOPSIS...
Dry and comfortable conditions persist through Saturday as high
pressure remains in place across the region. Rounds of showers
and thunderstorms in association with an upper level disturbance
and cold frontal passage are expected Sunday and Monday before
temperatures drop back below normal levels Tuesday and
Wednesday. Cooler temperatures will be met, however, with
drying conditions for the middle and end of the work week.

&&

.DISCUSSION...
Dry conditions accompany the end of the work week and the first
half of the weekend as surface high pressure and upper-level
ridging slide eastward on the heels of the departing Hurricane
Erin. Ample sunshine and deep mixing today will force
temperatures into the 70s to low 80s while northerly flow and
subsequent areas of downsloping will keep humidity well within
comfortable limits. And though tomorrow will see a northwest to
southeast increase in cloud cover, especially in the afternoon,
the crest of the upper ridge in tandem with flow backed to the
south and still plenty of breaks of sun will drive temperatures
into the mid 70s to mid and even pockets of upper 80s. Lows
tonight will radiate down to the upper 40s to 50s while more
mild values of mid/upper 50s to low 60s are anticipated for
Saturday night courtesy of more extensive sky coverage.

By Saturday evening, the aforementioned ridge and surface
anticyclone will be departing the region to the east, triggering
the fall in geopotential heights aloft in advance of a large-
scale trough digging south into the Midwest below a closed
upper low in eastern Ontario. An associated surface cyclone will
begin to deepen around the James Bay, extending a surface
trough southward through the eastern Great Lakes and Ohio Valley
regions. As the upper-level trough digs farther south and east
throughout the night Saturday, a weak shortwave will pulse
through its mean flow, becoming negatively tilted as it swings
by just to our north and west. Beneath it, the surface trough
will begin to track into the region, aligning with the right
entrance region of a weakening jet max aloft. Enhanced surface
convergence and sufficient forcing for ascent will support the
development of an initial line of showers that will slowly track
northwest to southeast into the region after midnight. Exact
timing and spatial spread of these initial showers is still a
bit uncertain, but generally the medium-range guidance is
beginning to align in an onset around or just after 06 UTC in
the Southwest Adirondacks. It is possible for an isolated
embedded rumble of thunder or two to occur within these showers,
especially in and around onset when forecast soundings still
show a meager amount of elevated instability, but the
probability is very low.

Any isolated thunder should conclude after midnight, but showers
will continue to track south and east into Sunday morning.
Spatial spread also remains in question at this time as showers
could begin to fall apart by late morning/early afternoon Sunday
as the shortwave departs to the northeast, the jet max weakens
further, and the surface trough also weakens. However, brief
breaks will later fill in as the upper trough digs farther south
and slides farther east, thereby reinforcing cyclonic vorticity
advection across the region. Additionally, the alignment of
southerly flow along the East Coast will strengthen moisture
transport and supply additional instability to reinvigorate
convection. The uncertainty here lies with the thunderstorm
threat. More prolonged breaks in showers during the morning and
early afternoon hours could help with destabilization and
recovery should breaks of sun occur. Certainly, with another jet
max beginning to take shape throughout the afternoon and evening
hours Sunday, with eastern New York and western New England
falling once again in the favored right entrance region, and
increasing surface convergence with the incoming cold front
behind the surface trough, there is sufficient forcing to
sustain at least showers. At this point, models are indicating
anywhere from about 500 to 1000 J/kg of SBCAPE with up to 20 kt
of low-level shear and marginally steep lapse rates around 6-6.5
C so scattered thunderstorms are certainly a realistic outcome.
However, with the stronger forcing off to our north and the
potential for limited breaks of sun, the strength of such will
likely be limited. The better alignment of these parameters
falls along and north of I-90, so the greater probability for
thunder was input into the forecast in these areas. However, we
will continue to monitor this potential going forward as lead
time and confidence increases.

Any thunder that occurs Sunday evening will soon be lost with
daytime heating Sunday night, though the slow progression of the
cold front and the persistent southeast dig of the upper trough
will ensure the continuation of showers overnight and into
Monday. Once again, thunderstorms will be possible Monday, but
the greatest instability is confined to areas along, south, and
east of the Hudson River Valley. That said, this "greatest"
instability is even less than that of Sunday with less shear and
less steep lapse rates, so the probability of strong to severe
thunderstorms is even lower.

The front finally clears the region by Monday evening, yielding
broad troughing in its wake and the subsequent chance for
scattered, lingering showers through Tuesday. After Sunday and
Monday`s near normal highs of upper 60s to low 80s, temperatures
drop off in the wake of the cold front Tuesday with values in
the 60s and 70s. Primarily dry weather returns for Wednesday
despite the incomplete departure of the upper trough as
northwesterly flow advects cooler, drier air in across the
region. Highs Wednesday will be a similar to those of Tuesday,
though a few degrees cooler, before a moisture-starved shortwave
backs flow to the west/southwest for Thursday and increases
values back to the upper 60s and upper 70s. Low temperatures
will be on the cooler side beginning Monday night with 40s and
50s expected through Thursday night.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Early morning fog at GFL resulting in MVFR vis will dissipate
shortly after daybreak. Then, VFR flying conditions persist
through 06 UTC. There is a low to medium chance that patchy
radiational fog resulting in MVFR vis develops again at GFL
from 06 - 12 UTC/Saturday given mainly clear skies and higher
humidity. North to northwest winds reach around 5-8kts late this
morning into this afternoon.

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

&&

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

&&

$$

SYNOPSIS...Gant
DISCUSSION...Gant
AVIATION...Speciale