-- Discussion containing changed information from previous version are highlighted. --
765
FXUS61 KPBZ 261623
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1223 PM EDT Thu Jun 26 2025

.SYNOPSIS...
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Hot and humid through the end of the week with daily afternoon
storm, isolated flooding, and severe wind chances. Rain chances
decrease Sunday, followed by another active period Monday to
Tuesday before temperatures return to near normal and conditions
trend slightly drier mid-week.
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&&

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

- Heat concerns continue through the afternoon for most of the
  area, with indices approaching 100F, hottest for valley and
  urban locations.
- A marginal chance of severe wind and flooding into the
  afternoon and evening with downburst potential.
---------------------------------------------------------------

Heat concerns linger through the period with mostly the effects
of cumulative heat stress. While we anticipate that heat will
not be as warm as days prior (40% to 80% chance of heat
indices >95F in the Heat Advisory Area). Impacts will be
highest for valley and urban locations given anticipated highest
heat indices and stresses on existing infrastructure.
Additionally, the impacts may be higher for areas that do not
receive rain and are not impacted by a cold pool, though the
exact locations remain low confidence up to a couple hours
before occurrence. In areas impacted by rain or cooler
temperatures, there may be some relief this afternoon.

As for the severe threat, the 12Z morning sounding has shown a
mostly saturated profile with weak, generally westerly, flow.
DCAPE is not as stark as the day prior, but SPC mesoanalysis
shows pockets of 800 J/kg to 1000 J/kg moving overhead with
roughly 1500 J/kg to 2000 J/kg of MLCAPE. A mature cell in this
environment will be capable of producing downburst wind
threats. RAP analysis indicates a freezing level of roughly
13kft as of noon and the -10C to -30C layer between 19kft and
28kft. A developed cell ingesting liquid water in an updraft
into this level would be most opportune to develop an icy core.
The higher the cell develops and the broader the cell is, the
moore likely severe criteria may be met at the surface when the
core falls out.

In tandem with the wind threat will come the flooding threat.
The morning sounding still has an anomalously high 1.68" PWAT
reading. With weak westerly flow, we would expect storms that
develop on the west side of cold pools (up-shear) to be mostly
stationary. Unlike yesterday, flow aloft is westerly, so anvils
may blow east and leave this side of developed cells in
comparatively clearer skies, and potentially more instability.
These reasons are all supportive of an afternoon/evening flood
threat that slightly lags the severe threats.

Development is generally expected in the 1pm to 3pm timeframe as
the convective temperature in the upper 80s are reached. The
most likely area for development today may be along the rugged
cumulus between Cleveland and Pittsburgh, perhaps aggravated by
an inland penetrating lake boundary.

Into tonight, convective coverage is expected to drop off,
though elevated instability may keep a very isolated shower or
two. Nonetheless, threat chances would be lower should any rain
develop. Dew points in the upper 60s and low 70s will keep
temperatures anomalously warm, with a 30% to 70% chance of
staying above 70F overnight, highest for the urban and valley
areas. This has justified the continuation of the heat advisory
with cumulative heat stress.
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&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
KEY MESSAGES:

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

On Friday, chances of >90F are again highest for valley and
urban locations, with NBM showing a 20% to 40% 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.

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.

&&

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

- Potential for storms and locally heavy rainfall through at
  least Tuesday and possibly on Wednesday.
-------------------------------------------------------------------

Sunday night will feature the potential of some lingering
showers and thunderstorms but the overall convection should
weaken with sunset and loss of daytime heating. This is
especially the case since temperatures have cooled off a tad.
Expect 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. The threat of
unsettled weather will likely continue.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
Patchy fog has plagued a few sites this morning, mostly those
that saw rain yesterday, with restrictions ranging from MVFR
down to LIFR with light wind and clear skies. Expect that as we
heat this morning, mixing will quickly commence and allow for
any restrictions to diminish within an hour to two after
sunrise.

Scattered thunderstorms are expected to develop this afternoon
and evening in a similar manner to Wednesday as convection
fires in the vicinity of a quasi-stationary front across the
region. Included a prob30 for thunder, variable wind gusts, and
associated restrictions at all airports during the most likely
time of occurrence.

Convection should wane again this evening with the loss of
daytime heating and diurnal instability. Mid-level clouds
should linger into the evening with VFR expected.

Outlook...
Patchy MVFR/IFR in fog/stratus is expected Friday morning with
low level moisture in place. More numerous showers and
thunderstorms are expected Friday and Saturday afternoon and
evening as the front wavers across the region.

There is a lesser potential for afternoon showers/storms on
Sunday as high pressure briefly brushes by to the north.
Showers/storms return again Monday with an approaching cold
front.

&&

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

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 8 PM EDT Friday for PAZ013-014-020>022-029-
     031-073-075.
OH...Heat Advisory until 8 PM EDT Friday for OHZ039>041-048>050-
     057>059-068-069.
WV...Heat Advisory until 8 PM EDT Friday for WVZ001>004-012-021-509-
     510.

&&

$$

SYNOPSIS...Milcarek
NEAR TERM...Milcarek
SHORT TERM...Milcarek/Shallenberger
LONG TERM...Milcarek/Shallenberger
AVIATION...WM/MLB
CLIMATE...MLB