682
FXUS61 KPBZ 190557
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
157 AM EDT Tue Aug 19 2025

.SYNOPSIS...
High pressure will maintain dry weather today. Scattered shower
and thunderstorm chances will return tonight and Wednesday with
a weak cold front. After seasonable temperatures Wednesday,
highs will gradually warm into the weekend.

&&

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

- Dry weather through today
- Gusty southeasterly flow across the ridges
---------------------------------------------------------------

Dry weather continues as high pressure remains anchored to the
northeast. Despite mostly clear skies and efficient radiational
cooling, dry boundary layer conditions (dew points in the 50s to
lower 60s) should limit widespread fog potential. Overnight
lows are expected to be near seasonable values. Weak low
pressure to our west and high pressure to the northeast wedging
down the Appalachians will tighten the pressure gradient early
this morning, leading to some gusty southeasterly conditions
across the ridges and foothills.

After sunrise, warm advection, dry conditions, and mostly to
partly sunny skies will push high temperatures back into the
upper 80s... lower 80s across the I-80 corridor and higher
terrain. Otherwise, quiet weather continues.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
KEY MESSAGES:

- Scattered shower/storm chances return tonight and Wednesday
- A few higher terrain showers possible Thursday afternoon
- Rainfall amounts remain low
----------------------------------------------------------------

Weak low pressure will cross the eastern Great Lakes by this
evening as the previously stalled front to our south lifts north
as a warm front. Scattered rain chances will increase overnight
ahead of the trailing cold front, dissipating in the wake of the
front by Wednesday afternoon/evening. Upslope showers across the
ridges may linger through the afternoon.

All indications are that precipitation will be widely
scattered, with some locations receiving very little rainfall.
Probability for >0.25" remains at 60% or lower, with highest
values north of Pittsburgh. Still, modeled PWATs for Wednesday
morning are anomalously high and range from 1.8 to 2.0". Though
unlikely, if deeper convection is able to develop, localized
flash flooding can`t be ruled out.

Renewed high pressure across the Great Lakes and Ohio Valley should
keep most of the area dry overnight into Thursday. However, weak
troughing could help to initiate stray diurnal showers
primarily over the ridges Thursday afternoon. With Hurricane
Erin to our east, flow will be out of the northeast on Thursday.

Near to just below average high temperatures are expected
through mid-week. Overnight lows remain a few degrees above
average.

&&

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

- Above average temperatures expected into the weekend
- Precipitation chances return Saturday into Sunday with a
  passing cold front
- Cooler weather begins next week
-------------------------------------------------------------------

Extended forecasts indicate that a ridge of high pressure over
the Ohio River Valley will be present into Friday, bringing
mostly dry conditions and temperatures that are near to above
average.

A passing cold front and an upper-level trough will likely
increase the chances of precipitation over the weekend, but
rainfall amounts this far out look paltry at best. NBM
PQPF for >0.25" range from just 20% west of Pittsburgh to 50%
east. Of note, machine learning does indicate a 5 to 15% chance
of severe weather with this passing front on Sunday, so this
will need to be monitored in the coming days.

Generally high confidence exists in persistent eastern CONUS
troughing by early next week. This should keep temperatures
below average through at least early week.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Passing clouds with a light gradient wind prevailing out of the
east/southeast can be expected as high pressure slides off to
the east. Afternoon cu will be favored with bases around
5-7kft. The gradient will tighten a bit ahead of approaching
weak low pressure with winds  veering more southerly around
5-10 mph.

Outlook...
Overnight into Wednesday, a weakening upper-level trough
approaching from the northwest will increase shower/thunderstorm
chances, which could result in temporary cig restrictions.
Thursday, VFR conditions will return with ensembles strongly
favoring high pressure and dry weather through the end the week.

&&

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

&&

$$

SYNOPSIS...Rackley
NEAR TERM...Rackley
SHORT TERM...Rackley
LONG TERM...Hefferan/Rackley
AVIATION...MLB/88