662
FXUS61 KPBZ 162158
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
558 PM EDT Fri May 16 2025

.SYNOPSIS...
There is potential for strong to severe storms tonight as a
cold front approaches. Drier and cooler conditions return Sunday
through early next week.

&&

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

- A decaying MCS is likely tonight somewhere in the Ohio Valley
  tonight, but confidence in location is low.
-------------------------------------------------------------------

Afternoon convective development along a convergence zone and
remnant outflow boundaries has now dissipated and exited our
area to the east. A few showers remain north of Pittsburgh, but
these too should exit within the next hour or two and give way
to a brief quiet period this evening.

Satellite imagery shows a pocket of much drier air and clearer
skies working in from the west. Some atmospheric recovery has
been noted across a good portion of Ohio where some cu have
developed and temperatures have touched the low 80s. This has
allowed for destabilization of up to 2000 J/kg of uncapped
MLCAPE. Lack of forcing is likely going to preclude any
additional development for the next couple hours despite the
ripe environment, but uncertainty increases into later tonight.

An ongoing MCS is pushing through southern IL and IN this
evening. This will be the focus for another round of storms
locally later on tonight, but confidence in how it evolves here
is still low. CAMs aren`t too bullish on the MCS extending far
enough north to reach much into SW PA as they mostly favor it to
dive south along the best CAPE gradient south of I-70. Given
the ample recovery that`s been achieved across Ohio and upstream
radar observations showing storms developing into central IL
and strong conglomerating cold pools propagating additional
development north, we could see impacts reaching up to I-70.
This is the "most probable" solution at this point.

Another possible, but lower confidence, solution is that
development can extend farther north. This would be reliant on
convection across the southern tip of Lake Michigan developing
and congealing cold pools with the southern dominant MCS. There
is ongoing agitated cu development over that way suggesting
convective initiation attempts may be imminent. This
afternoon`s storms have also left behind remnant outflow north
of Pittsburgh as well locally, and this could act as a trigger
for additional development later on. So, the CAMs still favor a
southward sprint of the MCS as it gets into our eastern Ohio
counties after 10pm or so, and the best chances of severe
tonight increasing the farther south of Pittsburgh you go. But,
will have to watch over the next couple hours to see how the
upstream stuff evolves to get a better idea of what it may look
like here.

&&

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

- A cold front will cross the area, bringing gusty winds and a
  cooldown.

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

Irrespective of prior weather, there is high confidence of a
cold frontal passage in the late morning and early afternoon.
With this and the upper low pulling across the northern Great
Lakes. This will pack the pressure gradient. Pre-frontally,
there is some indication that there may be a shallow cap as a
bit of pre-frontal warm advection rides up the axis of the
front. Should this exist, winds will not start the day gusty.
Should this be absent, gusts of 30-40 mph may develop in the
morning.

Into the afternoon, winds are expected to peak along the cold
front. Gusts could be heightened in showers/storms along the
front, mostly in the 40-50mph range, but the chance of severe
could not be ruled out completely. After the cold front, low
level cold-advection settles in, destabilizing profiles with the
potential to mix into 40kt 850mb winds. Winds behind the front
will be more likely than ahead of the front.

With daytime gusts a bit higher in the ridges of eastern Tucker
County, a wind advisory is in effect from 10am Saturday to 2am
Sunday, where gusts up to 50mph are possible. Winds die down a
bit overnight with decoupling

&&

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

- Cooler and drier pattern returns Sunday through Tuesday.
- Precipitation chances return Tuesday into Wednesday with
  another low pressure system
- Potential for heavy rain mid-week that warrants monitoring
-------------------------------------------------------------------

Models have been consistent that troughing over the Great Lakes
and northeast CONUS will maintain northwest flow over the local
area Sunday into Monday, keeping temperatures seasonable and the
weather dry through that time.

Probability of precipitation increases again late Tuesday into
Wednesday with a new low ejecting out of the Rockies and
tracking east across the Plains. A few model scenarios note a
stationary boundary straddling south of Pittsburgh with this
passing low. If that scenario plays out, heavy rain could pose
a threat for portions of the region around mid-week.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
A tough and uncertain forecast lies ahead. At this time it looks
likely that much of the TAF period can be VFR. The possible
interruptions to this are two separate periods of thunderstorms: one
this afternoon and another during the overnight hours.

Latest satellite shows a broad expanse of cirrus overspreading the
region originating from convection to our south. This cirrus will
act to limit heating across the southern portion of our region and
could mitigate some risk to see thunderstorms fire near MGW/ZZV/HLG.
Farther north along a BVI/IDI line there remains a boundary left
over from last nights convection, which will likely be the focus for
afternoon convection. This boundary has shuffled southward through
the day and poses a low threat to allow thunderstorms near
PIT/AGC/LBE, this has been included as a PROB30 through the
afternoon. BVI/FKL/DUJ have a slightly higher chance to see
thunderstorms this afternoon. Any of these storms can bring gusty
winds, and briefly lower VIS and CIG.

Storms overnight remain more uncertain as the complex that they are
associated with has not yet formed in the MO/IL region. This complex
is expected to move NE`ward towards us but models diverge on the
exact track as some favor a dive southward along the CAPE gradient
and some favor somewhat of a split where storms miss much of our
region. At this time I have moved our TEMPO groups back to PROB30
for the overnight period with growing uncertainty in track. A period
of MVFR showers may trail behind any MCS-like system tonight.

Outlook... Patchy restrictions in scattered showers are expected
Saturday and Saturday night under a crossing upper trough. VFR
returns Monday under high pressure. Restriction and rain potential
returns with a Tuesday warm front.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...Wind Advisory from 10 AM Saturday to 2 AM EDT Sunday for
     WVZ514.

&&

$$

SYNOPSIS...Cermak/Hefferan
NEAR TERM...MLB/Milcarek
SHORT TERM...Milcarek
LONG TERM...Cermak/Hefferan
AVIATION...AK