621
FXUS61 KPBZ 060554
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
154 AM EDT Fri Jun 6 2025

.SYNOPSIS...
A cold front will slowly move eastward into the Upper Ohio
Valley and stall through Friday. Rounds of showers and
thunderstorms are expected through the weekend, as waves of low
pressure track along the boundary. The main threats to monitor
are instances of damaging wind gusts today and Friday, and
instances of locally heavy rainfall creating flash flooding.

&&

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

- Decreasing coverage and intensity of showers/thunderstorms
  overnight
---------------------------------------------------------------

Update...
Made some adjustments to overnight pops/weather based on the
latest radar, meso analysis, and near term model data. An MCV
continues across the ridges, where thunderstorms with some heavy
rain were located. This is expected to track NE, with the storms
decreasing over the next couple of hours. Elevated instability
will remain overnight, though expect thunderstorm coverage to be
isolated until late tonight, when another shortwave approaches.
Also added some patchy fog, though this will be variable in
location overnight due to cloud cover, and where any brief
partial clearing occurs.

Previous discussion...
Outside of weak convergence along the higher terrain where
storms are continuing to develop (but sitting generally just
east of the forecast area), the loss of diurnal heating and exit
of an MCV has resulted in a downward trend in shower and
thunderstorm activity. However, subtle waves within the quasi-
zonal westerly flow may still allow for isolated
showers/thunderstorms to occur overnight with the warm/moist
environment in place.

Abundant cloud cover should aide overnight temperature to end up
around 5 degrees above the daily average though localized spots
seeing nocturnal rain could see additional cooling. The clouds
also should limit morning fog generation (favored areas would be
locations receiving higher rainfall amounts) despite a nearly
saturated boundary layer.

&&

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

- Showers and thunderstorms continue at times
- Marginal Risk for damaging thunderstorm wind gusts Friday
- Locally heavy rainfall possible through Friday night
----------------------------------------------------------------

The front will linger across the region on Friday as it remains
fairly parallel to westerly flow aloft. Surface-based CAPE once
again increases into the 1000-1500 J/kg range, fueling an
increase in shower and thunderstorm activity during the
afternoon and early evening. Another round of strong to severe
thunderstorms is possible, with isolated damaging wind once
again being the main threat, although DCAPE may be less
favorable. Another round of locally heavy rainfall/isolated
flash flooding is expected as well, as storms potentially train
near the stalled boundary, as PWAT continues to linger in the
1.5 to 1.6 inch range. Marginal Risks for severe thunderstorms
and flash flooding were maintained by SPC and WPC, respectively.

A vort max/shortwave trough crossing Friday night into early
Saturday morning should result in another round of showers and
thunderstorms crossing the region. A flooding potential could
continue with this activity, especially in areas that become
saturated with rainfall through Friday. The wave should push the
front further south with a locally heavy rain potential. This
wave should drive the front further south later on
Saturday,reducing rain chances during the day, especially north
of Pittsburgh. Another shortwave and surface low are expected
to develop and track east along the front Saturday night,
returning the front northward as a warm front. This should
maintain a chance of showers across the region overnight.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
KEY MESSAGES:

- Unsettled weather Sunday through Tuesday
- Dry Wednesday
-------------------------------------------------------------------

Models have trended toward a stronger shortwave trough crossing
the Upper Ohio Valley region on Sunday, as a surface low tracks
along the quasi stationary front to our south. The GFS is an
outlier, developing a stronger surface low and pulling the front
back farther northward than most other guidance. Stayed close to
the ensemble solution, resulting in increasing shower and
thunderstorm chances through the day with the passing wave.

Another trough is progged to tack from the Upper Midwest to the
Great Lakes and Upper Ohio Valley region Monday and Tuesday.
Shower and thunderstorm chances will again increase with the
approach and passage of the trough.

Dry weather is expected to return on Wednesday as the trough
exits, and surface high pressure builds in. Temperatures are
expected to average near seasonable levels through the period.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Iso/Sct light showers continue early this morning. Widespread
fog is not anticipated given cloud cover, though pockets of fog
have been observed. A few terminals (e.g. BVI/FKL) will likely
bounce up and down through the remainder of the overnight.

The next wave will reinvigorate showers near 12z. Cigs will
quickly lower into MVFR/IFR except south and east of PIT
(MGW/LBE). Showers will become spottier again by midday with
gradual cig improvement.

Scattered showers and thunderstorms are likely after 18z Friday
as convective temperatures are reached. Covered this threat with
PROB30s given scattered nature of potential thunderstorms.
Lingering showers/storms will diminish near 00z as cigs lower
into IFR areawide. Restrictions will continue through much of
Saturday morning.

Outlook... Widespread MVFR/IFR ceiling restrictions are expected
into Saturday as a series of shortwaves brings continued shower
and thunderstorm chances. These are likely to lift Saturday
afternoon with brief drying. Crossing low pressure will renew
restriction potential with rain on Sunday, with additional waves
of rain expected Monday into Tuesday.

&&

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

&&

$$

SYNOPSIS...CL
NEAR TERM...WM/Frazier
SHORT TERM...CL
LONG TERM...CL
AVIATION...Rackley