877
FXUS61 KPBZ 080735
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
335 AM EDT Tue Sep 8 2026

.WHAT HAS CHANGED...
Update to Key Messages.

&&

.KEY MESSAGES...
1) A passing trough and cold front late Wednesday into Thursday
will return showers and thunderstorms to the region.

2) An active weather pattern could occur early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...
Confidence remains high that quiet and dry weather will persist
through Wednesday afternoon under high pressure. Temperatures
will likely trend above average over the next 48 hours winds
shift from the south later today, ahead of an approaching
disturbance.

Models continue to depict a large-scale trough tracking over the
Great Lakes early Wednesday into Thursday. This system will
weaken the ridge over the central CONUS and allow more active
weather to develop across the region.

With the flux in low-level moisture (dew points climbing into
the upper-60s/low-70s) and sfc temps in the mid to upper-80s,
heat index values could approach 90 degrees by late Wednesday
afternoon in a few areas and cause heat stress to local
communities.

Between 7pm to 9pm Wednesday, precipitation chances will
increase just south of Lake Erie with an approaching trough
followed by a cold front. The probability of strong to severe
storms still remain between 5%-15%. However, instability may
limited updraft development.

The prolonged passage of the trough may support periods of
moderate to heavy rainfall totals on Thursday, potentially
resulting in isolated flooding near creeks and streams. Some
areas could receive 1 to 1.5 inches of rainfall during this
period.

Drier conditions are expected Friday with the exit of the cold
front and a building ridge.

KEY MESSAGE 2...

Machine-learning models suggest that after a brief period of
ridging, Friday through Saturday, our large-scale weather
pattern will transition to a more zonal flow. As a result, this
will allow disturbances forming upstream (near the Rockies) to
track into our area. This pattern could create a heavy rain
threat and/or a severe weather threat early next week and will
need to be monitored.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Confidence is high that VFR conditions will prevail for a number
of terminals throughout the TAF period. River valley fog may
once again occur in FKL this morning, reducing vis to IFR to
LIFR between 09Z to 12Z.

As a disturbance approaches the Great Lakes, variable winds
will shift to come from the south over the next 24 hours.

Outlook...
Restrictions with showers and thunderstorms return late
Wednesday into Thursday with a crossing cold front.

VFR returns Friday under high pressure, before a crossing
disturbance bring a low chance for restrictions on Saturday.

&&

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

&&

$$

DISCUSSION...Hefferan
AVIATION...Hefferan