395
FXUS61 KPBZ 300640
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
240 AM EDT Wed Sep 30 2026

.WHAT HAS CHANGED...
Upcoming weekend precipitation chances have decreased, otherwise
no major changes were made to the latest forecast.

&&

.KEY MESSAGES...
1) Mainly dry through Thursday, before shower chances return
with a Friday cold front

2) Cooler with periodic shower chances for the upcoming weekend

&&

.DISCUSSION...
KEY MESSAGE 1...
The upper level pattern will continue to feature a trough over
the central CONUS as the ridge over the east remains in place
but begins to weaken as it shifts to the east-southeast with
time. The now closed low at the base of the trough over the
central plains now opens and ejects a shortwave into the Lower
Ohio Valley. This will bring a cold front to the region entering
the Upper OH Valley by Thursday night. A weaker piece of energy
may travel the northern area of the ridge and bring some precip
to the northern counties on Wednesday night.

Otherwise, the main focus will be on the front attempting to
move through the region from the northwest. This will track east
through the overnight and into the day on Friday. The rainfall
threat will not be anything to be concern over since we have
been dry over the past week. The NBM suggest rainfall amounts
will not be too concerning as the probabilities of exceeding
only 0.50" will be between 40% and 60% across the area. As well,
the thunderstorm threat on Thursday night and into Friday will
be minimal as even the NBM gives a 10% chance of even reaching
500 J/Kg of SB CAPE. Even the prob thunder for this period is
only between 10% to 15%. Thus, nothing is worth mentioning in
the HWO at this time.

KEY MESSAGE 2...
Broad upper troughing is progged to set up across the NE CONUS
through the upcoming weekend. Saturday should be mainly dry and
cooler as surface high pressure builds in from the north, though
a crossing southern stream wave should result in shower chances
mainly south of I-70. Shower chances then increase on Sunday as
a northern stream shortwave rotates through the broad upper
trough. Cooler temperatures are expected, with highs just below
seasonable levels.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
As the coast low lifts to the northeast, cloud cover over the
western PA area will continue to clear out from west to east.
This will result in fog development tonight through dawn. Just
about every terminal is expected to go down to field mins, or at
least LIFR. This will mainly be during the 08Z to 13Z period.
Conditions will improve into the day tomorrow with light and
variable winds expected. The only cloud cover will be high
clouds through the day. Fog development will then also be
possible by Wednesday night as well.

Outlook...
VFR is expected through Thursday, with the exception of morning
fog. Restrictions in showers are likely with a Friday cold
front. Restrictions are possible south of I-70 Saturday, and
across the remainder of the are Sunday, with crossing
disturbances.

&&

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

&&

$$

DISCUSSION...Shallenberger
AVIATION...Shallenberger