689
FXUS61 KPBZ 161650
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1250 PM EDT Sun Aug 16 2026

.WHAT HAS CHANGED...
There is higher confidence in the potential for severe
thunderstorms this afternoon, given clearing skies to the west
allowing for increased instability. Beyond this evening, little
change was made to the forecast.

&&

.KEY MESSAGES...
1)Severe weather and flash flooding risks continue this
afternoon and evening with renewed thunderstorm development.

2) After lingering showers dissipate Monday, there is fairly
high confidence in dry weather until Wednesday/Thursday, when
the next front arrives.

&&

.DISCUSSION...
KEY MESSAGE 1...
The region remains in a relative lull of activity between
overnight/early morning activity and developing convection to
the west, where a couple of Severe Thunderstorm Warnings are
already in effect. The new activity is associated with a vort
max/MCV over northwest Ohio. Ahead of this, a good deal of
sunshine is allowing for a buildup of instability, and the HREF
suggests that 1500-2500 J/kg of surface-based CAPE is likely by
18Z, mainly south of I-80. Other convective parameters look best
from I-80 on south, roughly matching with the SPC Slight Risk
area. In particular, a pocket of 25-30 knots of 0-6km shear is
most likely in this region, supporting multicells with mainly a
damaging gust potential where cold pools help consolidate into
short lines. Lengthening low-level hodographs and sufficient
0-1km SRH continue to suggest a low-end tornado threat for any
ESE-moving storms.

Along with this the threat of flash flooding will continue to be
monitored, especially in areas that got heavier rain overnight.
This includes areas in eastern Ohio south of I-70, as well as a
strip extending from New Philadelphia ENE towards Butler County.
Although storms should be fairly progressive overall, the
environment remains highly supportive for efficient rainfall
production. The 12Z KPIT sounding recorded a precipitable water
measurement of 2.15 inches, which is the 9th-highest recorded
at the site since 1952. 2+ inch values remain in place through
this evening, along with 11k to 13k warm-cloud depths. The Flood
Watch will be maintained through tonight.


KEY MESSAGE 2...
Most of the convection should pull off to the east by 02Z-03Z,
although a few showers/storms may linger behind the main line as
another shortwave trough crosses in the mid-level zonal flow.
One last ripple in that flow crosses on Monday, leading to
showers and storms mainly south of Pittsburgh. Convective
parameters are unfavorable for severe weather with this
activity. Also, declining precipitable water values point to a
decreasing risk for heavy rainfall. The Flood Watch expires at 8
AM Monday, and an extension may not be needed.

High pressure building in from the Great Lakes should end
precipitation by Mon evening. Dry weather is then favored until
Wednesday, when the next front could potentially arrive,
although this timing could change. At this time, severe weather
and flooding risks appear low with this system, as supported by
longer-range machine learning guidance.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Mainly MVFR cigs continue this afternoon ahead of an approaching
prefrontal trough. A broken line of thunderstorms is expected to
track east across the region this afternoon and evening along
the prefrontal trough, with IFR restrictions. Some storms could
contain damaging wind and heavy rainfall. Included a tempo
mention in the tafs for the most likely time of arrival. Expect
a gradual deterioration back to IFR tonight with low level
moisture in place.

The surface cold front is progged to track across the region
Monday. Expect a gradual improvement in cig heights through the
day with mixing and some dry advection after FROPA. Airports
from near PIT and south could see a few afternoon showers or a
thunderstorm as this front crosses.

Outlook...
Other than early morning fog, VFR is then expected through
early Wednesday under high pressure. Restriction and
shower/thunderstorm chances return Wednesday and Wednesday night
with the approach and passage of a cold front. VFR returns
Thursday and Friday under high pressure.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch through Monday morning for PAZ020-021-029-031-
     073>076.
OH...Flood Watch through Monday morning for OHZ039>041-048>050-
     057>059-068-069.
WV...Flood Watch through Monday morning for WVZ001>004-012-021-
     509>514.

&&

$$

DISCUSSION...CL
AVIATION...WM