596
FXUS61 KPBZ 251734
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
134 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/...
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 and flooding threats in scattered storms this
  afternoon/evening.
---------------------------------------------------------------

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.

&&

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

- Heat concerns continue through Friday; heat advisory will be
  in effect through 8pm Friday.
- Daily downburst wind and flooding threats in the afternoon
  and evening.

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

Continued heat concerns linger through the period, though it is
anticipated to not be quite as intense as early this week, and
some areas may not attain forecasted highs should they be
affected by convection. So far for Thursday, HREF chances of
>90F are generally around or >50% for urban and valley
locations, and 20% to 40% likely for the lowlands south and west
of Pittsburgh.

HREF 25th to 75th MLCAPE is 1000J/kg to 1500 J/kg and DCAPE is
800 J/kg to 1200 J/kg, creating yet another day with confidence
in downburst potential should storms fully utilize their
environment. Environmental shear will be weak, with flow
generally from the west, so again, flooding potential will need
to be monitored on the up-shear, westerly side of any cold
pools that develop into the day. Afternoon HREF PWATS for
Thursday sit between 1.7 and 1.8 between the 25th and 75th
percentile, which is toward the 90th percentile of climatology.
So training in warm rain processes remains a threat.

Convective coverage may wain overnight with the loss of the best
heating and mixing, though elevated instability will again have
the low chances of a shower/storm. Again, NBM shows a 80% to
100% chance of lows >70F south and east of, and including
Pittsburgh, with chances a bit lower north of US-422. This will
again, provide little relief.

On Friday, chances of >90F are again highest for valley and
urban locations, with NBM showing a 30% to 50% chance. Heat
indices could push 100F in these areas yet again. This will
justify the continuation of the heat advisory through 8pm
Friday. Environmental parameters will be similar as days prior,
with LREF showing 1000 J/kg to 1500 J/kg MLCAPE, 600 J/kg to
800 J/kg DCAPE, and weak shear from the southwest with up-shear
flooding potential. Chances again taper off at night. Low
temperatures have a >50% chance of lows >70F again south and
west of Pittsburgh Friday night.

&&

.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
-------------------------------------------------------------------

Daily thunderstorm, downburst wind, and flooding threats
continue for the weekend during the afternoon/evening hours.
Initiation may be a bit more likely on Saturday as a front sags
south across the the center of the forecast area, and the front
may be a bit more likely south of I-70 Sunday as the front
continues its southward sag.

Both the southward sagging front and increased cloud cover
potential may keep temperatures a few degrees cooler into the
weekend. Most spread in temperatures is between the mid-to-
upper 80s. This will still be climatologically warm, but cooler
in perspective, which may allow heat risks to temporarily
reduce.

After a brief warmup Monday, there is some indication of a
brief troughing pattern by the middle of next week, though there
are some uncertainties in exactly how strong the trough will
be, as indicated by clustered variability.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Diurnal destabilization under impressive heating has already begun
to pop scattered convection across the region. The most favored
corridor remains near I-70 and MGW/ZZV have begun the TAF period
with VCTS prevailing. The environment continues to support storm
development region-wide and thus all ports have TEMPOs for
storms this afternoon. PROB30s for evening storms expanded as
well with continued chances for storms to into this evening
especially BVI on south. Any thunderstorm could support 30-40KT
outflow winds and rainfall rates between 1-2"/hr that could
drop VIS as low as 1SM.

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. HREF probabilities for VIS less than 4 miles are between
40-60% for all ports between 06-12z.

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...Milcarek
LONG TERM...Milcarek
AVIATION...Frazier/AK
CLIMATE...