835
FXUS61 KPBZ 171144
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
744 AM EDT Tue Jun 17 2025

.SYNOPSIS...
Showers and thunderstorms continue today, and the ongoing flood
threat has expanded to include areas farther north above the
I-80 corridor as a stalled front currently to our south lifts
north across the region. The ongoing active pattern should
break Friday, followed by drier conditions and area temperatures
climbing into the 90s by the end of the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Moderate Risk of flash flooding for much of the region today
- Flood Watch in effect from 11am until 10pm
- Isolated instances of a damaging wind threat south of I-70
---------------------------------------------------------------

Latest radar imagery shows showers and a few embedded storms
continuing as anomalously high moisture air continues to lift
over a boundary south of the region in southwesterly flow. There
is still concern that showers with moderate to heavy rain rates
could result in localized flooding this morning, particularly
along a line running roughly from Zanesville, OH to Pittsburgh
or Butler in SW PA, where current upstream convection over south
central Ohio is showing rates up to 3" per hour in some spots.
This will be closely monitored.

The aforementioned pseudo-stationary frontal boundary that has
been parked south of the region the past couple days will
finally push north as a warm front today as the associated
surface low cruises northeast up into Ontario. The overall,
environment will be very similar to the past couple days, but
PWATs will rise with increased moisture in strengthening
southwesterly flow, close to record levels. Storm motion will be
slightly quicker than previous days, but in any case the risk of
heavy rain will be high given near record PWATs of 2", warm
cloud depth ~12kft, HREF mean CAPE values up to 1500 J/kg, and
many areas primed for flooding due to previous rainfall.
Ensemble guidance shows good continuity with previous runs,
showing a swath of highest amounts roughly between Pittsburgh
and Dubois. Overnight, the Excessive Rain Outlook was upped to
a Moderate Risk by WPC, which is appropriate given the
environment and antecedent conditions. A Flood Watch was issued

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
KEY MESSAGES:

- Showers and thunderstorms continue into Wednesday, with
  increased potential for strong to severe storms

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

Unsettled southwest flow continues overnight as additional
embedded shortwaves and jet induced ascent support rounds of
showers and isolated thunderstorms, though the focus for
greatest coverage shifts to areas generally south of Pittsburgh.
The flood risk could continue with these into early Wednesday
morning, especially if they impact any locations that have
already experienced flooding issues due to recent rain.

A trough will then advance eastward across the Great Plains and
towards the Great Lakes, resulting in strengthening deep- layer
west- southwesterly flow downstream over the Ohio Valley. Weak
500mb height rises over the local area could provide enough
subsidence aloft to inhibit shower and thunderstorm activity
Wednesday afternoon and evening, with model soundings suggesting
a rather stout capping inversion forming near 700mb. This would
be for the best, as the same soundings also suggest that the
strengthening deep-layer flow, lingering low-level moisture, and
dry air aloft (due to the aforementioned subsidence) would
otherwise support damaging winds (1000+ J/kg DCAPE) and large
hail (2500+ J/kg SBCAPE) in storms.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
KEY MESSAGES:

- Showers and thunderstorms continue Wednesday and Thursday,
  including increasing severe potential
- Hot and dry weather returns this weekend into next week
-------------------------------------------------------------------

The upper trough continues to advance eastward across the Great
Lakes Wednesday night into Thursday. As it approaches, height
falls and strengthening large-scale forcing overspread the
region, leading to showers and thunderstorms forming over Ohio
and moving east across the local area. These storms will still
carry a severe weather threat, primarily for damaging winds and
large hail. The Storm Prediction Center currently has much of
the local area in a Marginal Risk (Level 1 out of 5) during that
period. The heavy rain and flooding threat will likewise
continue with these storms, although faster motions will help
limit residence time in any one location and therefore the
threat will become more isolated to areas that already flooded
due to heavy rains in recent days.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
A wide mix of conditions are ongoing across the area to start
the TAF period as decaying showers and weak overrunning along a
stalled boundary are producing instances of MVFR/IFR at some
terminals while VFR prevails elsewhere. This mix of conditions
continues through the morning until heating and mixing allows
for general improvement to VFR, save for FKL/DUJ where MVFR may
persist into the afternoon. Scattered showers and thunderstorms
develop across the area late morning through the afternoon and
evening as an upper trough approaches from the west. Maintained
TEMPOs to reflect the most likely window for heavier rain,
thunder, and associated restrictions. Outside of convection, low
VFR or potentially high MVFR cigs prevail. Widespread IFR
settles in overnight as shower activity tapers but low-level
moisture lingers. Winds remain light through the period and
generally out of the south or southwest.

Outlook...
Periodic restrictions remain possible through Wednesday as
another upper level wave crosses the region. More widespread
showers/thunderstorms (and associated restrictions) are
expected late Wednesday into Thursday with the approach and
passage of a cold front. Late night/early morning stratus and
fog is also likely. General VFR is expected to return Friday
through the weekend as ridging begins to build in.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch from 11 AM EDT this morning through this evening
     for PAZ007>009-013>016-020>022-029-031-073>078.
OH...Flood Watch from 11 AM EDT this morning through this evening
     for OHZ039>041-048>050-057>059-068-069.
WV...Flood Watch from 11 AM EDT this morning through this evening
     for WVZ001>004-012-021-509>514.

&&

$$

SYNOPSIS...88
NEAR TERM...88
SHORT TERM...88
LONG TERM...Cermak/Frazier/88
AVIATION...Cermak/WM