548
FXUS61 KALY 192328
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
728 PM EDT Tue Aug 19 2025

.UPDATE...
As of 725 PM EDT, have increased PoPs across NW areas quicker
based on latest radar trends and obs, with spotty light rain
already spreading across far northern Herkimer/Hamilton
Counties, with additional showers across central NYS tracking
eastward. Periods of rain should overspread many areas north of
I-90 and west of I-87 by around, or shortly after midnight,
while remaining dry during this time farther south of I-90.

&&

.SYNOPSIS...
Clouds will thicken this evening ahead of an upper level
disturbance and a low pressure system approaching from the lower
Great Lakes and Ohio. This system will bring a widespread
rainfall late tonight into Wednesday night. Drier weather
returns Thursday through Saturday with temperatures gradually
rising back near normal to slightly above normal.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Key Message:

- There is a 50-80% probability for greater than a half inch of
  rainfall late tonight through Wednesday night across the
  area.

Discussion:

Forecast remains on track for a widespread soaking rainfall
across the area starting late tonight through Wed evening. An
upper level short wave trough approaching from the Great Lakes
will interact with an inverted surface trough that will set up
across western NY into the St. Lawrence Valley. Low level
convergence/F-Gen will increase in proximity of the surface
trough resulting in rain developing. Deep layer moisture
increases with NAEFs indicating PWAT anomalies increasing to +1
to +2 STDEV into Wed. So rainfall amounts have increased to
around 0.50-1.50" although with limited instability aloft, most
of the precip will be stratiform with a few embedded convective
elements with duration spread out over several hours. So this is
anticipated to be a beneficial rainfall with no flooding
expected. With clouds/rainfall and an onshore SE flow,
temperatures will be quite cool with highs only in the
50s(mountains) and 60s(valleys).

Showers will linger into Wed evening, then taper off overnight
as the short wave moves east into New England. There still looks
to be some bagginess in the surface pressure with the weakening
inverted trough lingering across western/central NY so will
maintain slight/low chance of light showers overnight into early
Thu morning with mostly cloudy skies.

Ridging at the surface and aloft builds in on Thu across our
area, which will be north/west of Hurricane Erin as it tracks NE
well off the mid Atlantic coast. Clouds could linger well into
the morning with a clearing trend expected by afternoon.
Temperatures will be warmer than Wed, but still below normal for
mid August. Mostly clear and cool conditions expected Thu night
with high pressure in control.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Key Messages:

- Temperatures briefly rise above seasonal normals on Saturday.

- Chances for showers and thunderstorms increase Sunday into
  Monday.

Discussion:

High pressure remains in place on Fri, as Hurricane Erin
continues to track out to sea well south/east of New England.
With abundant sunshine and a moderating air mass, high
temperatures should get back to near normal levels Fri
afternoon. On Sat, surface high pressure moves east off the New
England coast, while the main upper level ridge axis shifts into
New England during the day. This should provide one more dry
day across our area, with temperatures warming slightly above
normal as a southerly flow develops around the departing high.
Humidity levels expected to remain fairly comfortable through
Sat though.

As a large scale trough builds south/east from Canada and the
upper Great Lakes on Sun, a leading cold front associated with
this system is expected to move east into the area. This should
result in scattered to numerous showers/T-storms developing as
humidity and instability increase ahead of the front. Chances
for showers linger into Mon, as some guidance indicating the
front`s eastward progress may slow. Temperatures will be cooler
with more cloud cover and the upper trough moving in. Tue looks
mainly dry and cooler, although an isolated diurnally driven
shower cannot be ruled out with the broad upper level trough
over the region.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions through this evening. Then, areas of light rain
will develop from NW to SE later tonight through Monday morning.
Initially VFR conditions should gradually become MVFR,
especially for Cigs toward and after 12Z, with mainly MVFR
conditions developing for much of Wednesday, again mainly for
Cigs. However, some pockets of moderate/heavy rain may produce
periods of MVFR/IFR Vsbys from mid morning through the
afternoon, especially at KALB and KPSF, with some IFR Cigs
possible as well.

Winds will be light/variable tonight except southeast 5-10 KT at
KALB. Winds will become mainly east to northeast Wednesday at
5-10 KT, with a few gusts up to 15-20 KT possible in the
afternoon, especially at KPSF.

Outlook...

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

&&

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

&&

$$

UPDATE...KL
SYNOPSIS...JPV
SHORT TERM...JPV
LONG TERM...JPV
AVIATION...KL