817
FXUS61 KPBZ 020435
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1235 AM EDT Tue Sep 2 2025

.SYNOPSIS...
Widespread rain chances return Thursday with the
approach and passage of a cold front. Gusty winds and isolated
storms are also possible with the passage of the front. Cooler
and relatively drier weather returns late week.

&&

.NEAR TERM /THROUGH TODAY/...
KEY MESSAGES:

- Patchy river valley fog is possible
- Isolated showers activity near the ridges this afternoon
---------------------------------------------------------------

GOES-19 Nighttime Microphysics imagery depicts broken mid-level
clouds over portions of the region early this morning. Areas
with prolong clearing, patchy river valley fog could develop
between 4am and 6am.

After sunrise, river valley fog will dissipate with surface
heating/mixing. Isolated, terrain-driven showers are possible in
the Laurel Highlands this afternoon (between 1pm and 5pm) with
shallow instability. This is considered a low chance of
occurrence (10-15%). Otherwise, mostly dry conditions across the
region.


&&

.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
KEY MESSAGES:


- Isolated showers possible south of I-70 Wednesday afternoon

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The upper low will begin to lift out of the area and into the
Canadian maritimes Tuesday night while surface wind becomes a
bit more southerly. This will aid in better moisture return on
Wednesday, increasing humidity a bit and boosting afternoon
highs a few degrees above average. A weak shortwave will cross
the region by Wednesday afternoon, but will likely arrive before
better moisture from the south. NBM PoPs show slight chances
for rain Wednesday afternoon from ZZV to MGW, but any showers
are likely to remain isolated as deeper moisture remains much
farther south across the Tennessee Valley.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
KEY MESSAGES:

- Showers, thunderstorms, and gusty winds are expected with a
  cold front passage on Thursday
- Cooler and generally dry weather returns in the weekend
-------------------------------------------------------------------

Better moisture arrives Wednesday night into Thursday with
increasing southerly flow. This should allow increasing cloud
cover and shower chances by early Thursday morning. Cloud cover
and rain chance will keep low temperatures near normal for the
first time in a while.

Better chances of more widespread rain will return Thursday
morning/afternoon ahead of the cold front. Some variability
remains with the strength of the trough, stronger likely
yielding more plentiful rainfall, and weaker keeping most totals
below 0.5". With strong forcing, quick frontal movement, and
deep mixing below a 50kt 500mb jet, gusty winds of 30-40 mph
will be possible Thursday afternoon ahead of and along the
front. NCAR ML convective forecasts low-end severe potential
along the front, but generally keep better chances east of our
area. Any severe threat will need to be monitored, especially as
we come within CAM ranges.

Friday, the closed low may wobble around with some solutions
placing the low over Ontario, and other along the southern shore
of the Hudson Bay. Again, a more southerly and/or stronger
position would mean cooler temperatures, generally more clouds
(or even showers) chances on shortwave spokes, and generally
gustier winds. A more northern and weaker track would mean the
opposite. This keeps next weekends temperature spread anywhere
from the upper 60s to mid 70s for highs, daytime wind spread
anywhere from 25mph to 35mph maximum gusts, and rain chances
anywhere from 0% to 30%.

Most ensembles see a warming trend back to near normal
temperatures as we head into the middle of next week, with only
the exact timing of the warmup the main axis of uncertainty
depending on the departure of the eastern trough.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
High confidence VFR conditions continuing through the TAF
period under high pressure. A dry boundary layer and plenty of
subsidence will make for a continued period of mid and upper
level cloud cover for tomorrow as well.

Wind settles becoming light to variable tonight. Winds will stay
variable through the day tomorrow as well. Some river valley
fog is again possible early Tuesday morning but, similar to
Monday morning, probability of impacts to terminals is low.

.OUTLOOK....
VFR conditions continue through Wednesday. The passage of a
cold front on Thursday will bring rain with the possibility of
isolated thunderstorms. The boundary is also forecast to bring a
strong vertical wind profile, which increases the chance for
low-level wind shear and/or wind gusts.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

$$

SYNOPSIS...Hefferan
NEAR TERM...Hefferan
SHORT TERM...Rackley/Milcarek
LONG TERM...Rackley/Milcarek
AVIATION...Shallenberger