585
FXUS61 KPBZ 150525
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
125 AM EDT Wed Oct 15 2025

.SYNOPSIS...
Dry conditions and near normal temperatures are expected through
Friday. Morning frost and localized freeze conditions are
possible both Thursday and Friday. Rain may return for portions
of the region Saturday before more widespread rain with a cold
front Saturday night and Sunday.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
KEY MESSAGES:

- A dry cold front will cross overnight and increase cloud
  cover.
---------------------------------------------------------------

Latest surface analysis shows a weak/dry cold front already
through the forecast area. Cold advection behind this feature
should allow an increase in stratocu this morning. This cloud
cover and delayed arrival of cooler air means overnight low
temperature remains near to slightly above the daily average.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
KEY MESSAGES:

- High confidence in dry conditions
- Frost/freeze conditions appear increasingly likely Wednesday night
and Thursday night
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There is high confidence in dry conditions persisting Wednesday and
Thursday as the local area remains under an area of northwest flow,
sandwiched between a broad upper ridge over the central CONUS and a
deepening longwave trough over the western Atlantic. Cooler air will
filter into the area in response to the amplifying pattern, with
high temperatures each afternoon returning to near seasonal levels
(low 60s for the Pittsburgh area). As the surface high shifts
eastward and centers more over the lower Great Lakes, we will see
drier air and calming winds which should result in very efficient
nighttime radiational cooling.

A frost/freeze remains possible both Wednesday and Thursday nights.
The most likely areas to experience frost will be north and east of
Pittsburgh, where NBM probabilities are near 100 percent for low
temperatures dropping to 36F or lower (a decent proxy for frost
formation in situations like this). Elsewhere across eastern OH,
northern WV, and southwestern PA, locations outside of the immediate
Ohio River valley generally see frost probabilities ranging from 40
to 60 percent. With respect to freeze conditions, NBM probabilities
for low temperatures at or below 32F are as much as 60-90% for areas
north and east of Pittsburgh and the Laurel Highlands. Therefore,
expect some combination of frost/freeze headlines Wednesday night.

There are higher probabilities for frost/freeze conditions across a
larger portion of the area Thursday night, but any headlines for
that period will be dictated by the expanse and magnitude of
frost/freeze conditions Wednesday night, as the growing season may
end for many locations on Thursday.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
KEY MESSAGES:

- Above average temperatures return Friday into the weekend
- Rain chances increasing late this weekend

-------------------------------------------------------------------

The central CONUS ridge shifts eastward Friday through the weekend,
centering over the local area early Saturday and over the eastern
seaboard on Sunday as an upstream trough deepens over the upper
Midwest and Great Lakes. Mostly dry conditions can be expected to
start the period, though guidance does suggest a low chance for
decaying rain showers to make their way across mainly the northern
half of the area Friday night into early Saturday morning. However,
confidence in this occuring remains low as ensembles are currently
in a rather significant disagreement regarding the magnitude of dry
air below 700mb and thus the amount of sub-cloud evaporation. The
current NBM mean maintains low (20-30%) PoPs north of I-70 which
seems reasonable at this time given the uncertainty. Regardless, if
precipitation occurs it would be very light, with even the LREF 90th
percentile topping out at only a tenth of an inch of total rainfall
during that period (and primarily focused north of Pittsburgh).

As the central CONUS trough continues to advance eastward, it pushes
the upper ridge out over the western Atlantic, returning the local
area to unsettled weather and increasing chances for showers and
thunderstorms Saturday night through Sunday night. Current ensemble
guidance indicates 24-hour totals generally ranging from 0.25" to
0.75" across the region within the 25th to 75th percentile range.
However, there continues to be some outlying members that indicate a
non-zero chance for higher amounts approaching 1.0 to 1.25 inches in
some locations.

Temperatures trend warmer Friday through Sunday, climbing back above
seasonal normals with the warmest day looking to be Saturday as
highs climb into the low to mid 70s. A cold front on Sunday brings
temperatures back down to near seasonal levels to start next week.

&&

.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
Much of the area through dawn will be dealing with just some
upper level cloud cover. However, conditions at FKL and DUJ and
to some extent, LBE, will be dealing with some IFR/MVFR cigs
through dawn. Expect much of this to lift by late morning. The
rest of the terminals should be VFR through the period. Light
and variable winds will continue as well.

Dry advection and subsidence will erode any MVFR stratus by
Wednesday afternoon (80-90% confidence of VFR by 18z).

.OUTLOOK...
Surface high pressure with height rises aloft favor VFR into
Saturday morning before a series of shortwaves ahead of the next
cold front bring increased rain and restriction chances.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Frost Advisory from midnight tonight to 9 AM EDT Thursday for
     PAZ007>009-013>016-020>022-029-031-073>078.
OH...Frost Advisory from midnight tonight to 9 AM EDT Thursday for
     OHZ039>041-049-050.
WV...Frost Advisory from midnight tonight to 9 AM EDT Thursday for
     WVZ001-002-509>514.

&&

$$

SYNOPSIS...Frazier/88
NEAR TERM...Rackley/Frazier/88
SHORT TERM...Cermak
LONG TERM...Cermak
AVIATION...Shallenberger