704
FXUS61 KPBZ 090542
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
142 AM EDT Sat May 9 2026

.WHAT HAS CHANGED...
Little change to the forecast since the last update. Key
messages continue to be the marginal risk for severe storms
over northeast OH and northwest PA late this afternoon/evening,
and potential frost/freeze concerns Monday night.

&&

.KEY MESSAGES...
1) There is a marginal risk for damaging winds and large hail
with a decaying line of thunderstorms entering northwest PA
late this afternoon into this evening.

2) Great Lakes and eastern CONUS troughing will maintain below
average temperature and periodic rain chances into next week,
with potential for frost/freeze concerns Monday night.

&&

.DISCUSSION...
KEY MESSAGE 1...
Upper shortwave trough movement across the Great Lakes will
trigger thunderstorm development in the vicinity of Lake Erie
late this afternoon and evening. Clearing during late morning
and early afternoon will favor moderate destabilization across
eastern OH and western PA, with latest HREF interquartile
SBCAPE still ranging from 500-1000 J/kg. Enough wind shear (HREF
probability of 40 knots >90%) should also be present to support
organized storm modes and thus a marginal threat for severe
weather. Investigation of convective-allowing model soundings
suggest the primary threats will be damaging wind gusts and
possibly some large hail, though the latter depends heavily on
how quickly storms grow upscale into a line or line segments as
that would limit hail growth.

The main uncertainty with this threat is tied to timing of the
shortwave and convective initiation. Instability drops rapidly
towards (and following) sunset, with HREF probabilities for even
just 250 J/kg SBCAPE falling below 50% by 8pm and near zero by
10pm. Hi-res models have waffled a bit over the past 24 hours
with timing, ranging generally from 5-8pm on the early end to
7-10pm on the later end. The earlier solution would be the one
that presents the greatest severe threat, while the latter would
more likely feature a decaying line of sub-severe storms or
showers.

The most likely scenario at this time appears to be one that
falls in the middle of the two mentioned above, where
thunderstorms form along the Lake Erie shoreline and present a
low, but non-zero, threat for severe weather during a narrow
window of time (perhaps as short as 2-3 hours) prior to sunset.
This threat would be focused over NE OH and NW PA, mainly
along/north of the I-80 corridor. Rapid decay to sub-severe
storms or showers then occurs after sunset as convection
advances southeastward across eastern OH and western PA before
dissipating entirely overnight.


KEY MESSAGE 2...
Ensembles remain resolute in maintaining Great Lakes troughing
through the latter portion of next week, though some variance
exists in the exact shape/depth plus traversal times of embedded
shortwave troughs. This will maintain recent weather regimes
featuring below average temperature and some period of rain
possible within a 24-hour window while keeping hazardous weather
threats low.

One item of note is a potential of a strong cold advection push
behind a wave Monday that, combined with calming wind and
clearing skies, could result in more frost and freeze concerns
Monday night into Tuesday morning.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A wave is currently moving through, bringing rain and
restrictions from the north. Over the coming hours, rain is
expected to fill in across the area, along with patchy
restrictions north of HLG and MGW. Probability of MVFR peaks at
80% to 100% north of, and including PIT. Chances of IFR cigs in
rain are only >50% at BVI, FKL, and DUJ with rainfall rates a
bit heavier. Occasional drops to LIFR/VLIFR are entirely
possible in rain at DUJ/FKL through morning. Patchy MVFR is
possible south of PIT, but probability is lower at 20% to 60%.

Restriction chances peak before 15Z, with improvements favored
from 15Z to 19Z, with chances of MVFR cigs less than 50%
thereafter as cigs clear out and rain departs to the east.
Scattering to VFR into the day is favored (80% chance). Winds
may occasional gust up to 20kts out of the southwest during the
day.

Saturday evening, a line of storms is favored to drop south from
Lake Erie, with the high chance of lightning at FKL. Storms
advance south between 00Z and 06Z, with decaying lightning
chances as a transition to showers is most likely for now as the
rain approaches PIT. Late Saturday night, patchy drops to MVFR
are favored for AGC and north, with IFR most likely at DUJ.

Outlook...
Rain and restrictions are expected again during the day
on Sunday under the continued series of crossing shortwave troughs.
VFR should return Monday/Tuesday under high pressure.

&&

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

&&

$$

DISCUSSION...Cermak/WM/Frazier
AVIATION...Milcarek