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860
FXUS61 KPBZ 251611
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1211 PM EDT Wed Jun 25 2025

.SYNOPSIS...
Hot and humid through the end of the week with daily afternoon
storm, isolated flooding, and severe wind chances. A slight
cooldown is possible this weekend, though storm and flood
chances may linger during daytime hours through early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
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KEY MESSAGES:

- Extreme Heat Warning through 5pm for Pittsburgh metro.
- Heat advisory will continue for SW PA, north WV, and east OH
  through 8pm Friday.
- Downburst wind threats in scattered storms this afternoon.
---------------------------------------------------------------

Official NWS obs and RAWs sites show heat indices climbing into
the upper 90s as of noon with still a few hours of heating
possible into the day today, which will justify the continuation
of heat headlines through the 5pm timeframe. Given high to
extreme heat risk through at least Friday for parts of the area
with heat indices fringing on 100F during peak heating and lows
struggling to get below 70F, a continuation of heat advisory
will be necessary for most areas in the current products through
8pm Friday.

As for severe potential this afternoon, storm coverage is
expected to begin over the next few hours as convective
temperatures in the upper 80s and low 90s are reached. This will
bring a notable downburst wind threat for areas where storms to
pop up. While it may be difficult to pinpoint exact where storms
will form today, much like bubbles boiling in a pot of water, we
are beginning to see cu coverage increase in ruggedness in
eastern Ohio, the high terrain, and northern WV with perhaps a
weak boundary strewn a just north of Pittsburgh. This might be
the most likely areas for some convection to pop.

Morning MLCAPE was around 1000 J/kg with an astounding 1200
J/kg of DCAPE which, if fully utilized, would be able to realize
downburst wind threats. While moister air dipping down from the
north may be able to reduce DCAPE some, the threat remains
nonetheless. As per normal downburst environments, winds will
remain a primary threat and hail a distant secondary threat.
Additionally, with morning PWATS near 1.83" which may get even
higher into the afternoon, flooding treats are possible, but
strong cold pool development would mean make raining in one area
for an extended period difficult, and flooding may be more
dependent on initiation on the west side of outflow, fighting
the weak environmental shear, and inevitably training. Flooding
concerns increase in the late-afternoon and evening hours before
tapering overnight.

Into tonight, with loss of heating, storm chances drop off with
patchy valley fog possible with dew points as evaluated as they
are. Some patchy convection is possible in elevated instability,
but chances any individual area sees rain will be low. Chances
of lows >70F are generally >50% everywhere, meaning little heat
relief overnight.
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&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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KEY MESSAGES:

- Locally Heavy Rainfall Through Friday
- Daily showers and thunderstorms, especially in the afternoon
  and evening
- Strong storms possible each afternoon and evening

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

The quasi-stationary front is expected to lift northward on
Thursday, as another shortwave tracks along the northern
periphery of the upper high. Expect showers and thunderstorms to
increase in coverage again, peaking in the afternoon and early
evening. The mid levels moisten some over what is expected to be
seen Wednesday, though enough dry air is in place to again
result in some wind gust potential with any more organized
storm. CAPE is progged to range from 1500-2000 j/kg by
afternoon, with little shear in weak flow aloft. An increasing
potential for locally heavy rain and flash flooding is expected.
Will monitor conditions over the next few days for any need of
a flood watch. HREF PWATS are progged at 1.6 to 1.8, with the
weak flow aloft resulting in slow storm motions.

Convection should again wane Thursday evening with the loss of
daytime heating and diurnal instability, and as the surface
front lifts northward, as surface low pressure tracks along the
front into Michigan.

A general lull in the activity is expected Friday morning,
before showers and storms increase again by afternoon as the
surface low tracks across the Lower Great Lakes and southern
Ontario. The low will pull a cold front back to the south,
approaching the Upper Ohio Valley region in the afternoon. More
organized storms are possible. The potential for gusty wind will
continue in some storms with dry mid level air enhancing the
DCAPE. PWATs are expected to lower somewhat on Friday, though
with relatively weak flow aloft a locally heavy rain/flood
potential will continue with slow storm movement. Convection
should again wane in the evening with the loss of diurnal
instability.

Very warm and humid conditions will continue through the period.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
KEY MESSAGES:

- Active weather continues with daily shower and thunderstorm
  chances into the start of next week
- Potential for storms and locally heavy rainfall through the
  period
-------------------------------------------------------------------

Model ensembles indicate westerly flow aloft across the Upper
Ohio Valley region through the weekend. Shortwaves embedded in
this flow will continue to result in daily showers and
thunderstorms, with the greatest coverage in the afternoon and
evening hours. Elevated PWATs will maintain a locally heavy
rainfall potential as well.

A deepening trough is then expected to track from the Upper
Midwest to the Great Lake and Upper Ohio Valley region early
next week. This will maintain showers and thunderstorms in the
forecast. The trough axis, and a surface cold front, is
currently progged for a Tuesday passage. A break from the active
pattern is expected after FROPA.

Temperatures are expected to continue to range from 5 to 10
degrees above average for much of the long term period.

&&

.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
Weak shortwave movement that nudges the upper ridge south
combined with diurnal destabilization will allow isolated to
scattered thunderstorm development aft 18z today, with HREF
modeling favoring the I-70 corridor. The storm environment will
support storms that could produce 1-2"/hr rainfall rates that
quickly lower visibility to 1 mile or less while also generating
erratic gusty outflow winds that could exceed 30kts. Attempted
to provide some wind direction within tempo thunderstorm mention
based on broad atmospheric motion but vastly different
directions can occur.

Loss of diurnal heating should decrease convective activity
after 00z, but the moist/warm environment could allow for
isolated storms to persist or develop through the overnight
hours. Gradual clearing of convective cloud blow off through
Thursday morning may allow for strong radiational cooling that
leads to patchy low stratus/fog, favoring locations that
received higher rainfall totals during the afternoon.

Outlook...
Little pattern change is expected through Tuesday which means
that mainly diurnally driven scattered thunderstorms are
expected during this timeframe. Restrictions will be mainly
tethered to thunderstorm activity and patchy morning stratus/fog
that is dependent on overnight clearing and degree of daytime
saturation (i.e. amount of rainfall received the prior
afternoon).

&&

.CLIMATE...
Daily record high maximum (left) and daily record high minimum (right)
temperatures for Wednesday and Thursday are listed below.


Wednesday June 25th
Pittsburgh, PA:         98F (1988)              75F (1952)
Zanesville, OH:         101F (1988)             72F (1952)
Morgantown, WV:         94F (1921, 1952, 1988)  74F (1952)
Dubois, PA:             91F (1966)              67F (2000)
Wheeling, WV:           97F (1943)              75F (1952)
New Philadelphia, OH:   92F (1966, 2002, 2005)  68F (2013)

Thursday June 26th
Pittsburgh, PA:         95F (1966)              75F (1952)
Zanesville, OH:         97F (1952)              73F (1952)
Morgantown, WV:         96F (1952)              74F (1952)
Dubois, PA:             91F (1966)              66F (2000)
Wheeling, WV:           96F (1943, 1952)        73F (1952)
New Philadelphia, OH:   99F (1988)              71F (2022)

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 5 PM EDT this afternoon for PAZ013-022-031-
     077.
     Extreme Heat Warning until 5 PM EDT this afternoon for PAZ014-
     020-021-029-073-075.
OH...Heat Advisory until 5 PM EDT this afternoon for OHZ039>041-
     048>050-057>059-068-069.
WV...Heat Advisory until 5 PM EDT this afternoon for WVZ001>004-012-
     021-509-510.

&&

$$

SYNOPSIS...Milcarek
NEAR TERM...Milcarek
SHORT TERM...WM
LONG TERM...WM
AVIATION...Frazier
CLIMATE...MLB