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612
FXUS61 KPBZ 241847
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
247 PM EDT Tue Jun 24 2025

.SYNOPSIS...
Hot and humid conditions will continue today. There is a slight
chance of a late afternoon and evening thunderstorm mainly
north and west of Pittsburgh. Hot and humid weather will
continue Wednesday, with shower and thunderstorm chances
increasing through the day with an approaching cold front.
Unsettled weather is then expected through the weekend as the
front stalls across the region.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --
KEY MESSAGES:

- Extreme Heat Warning/ Heat Advisory in effect.
- Mainly dry and hot again today.
- Conditional potential for an afternoon severe storm.
- Overnight lows in the low to mid 70s.
---------------------------------------------------------------

A 594 dam 500 mb high will remain centered across the Ohio Valley
region today. Low level ridging at 850 mb also remains across the
region. With similar conditions to those seen on Monday, expect high
temperature in the lower to mid 90s for the region outside of the
higher terrain areas. Heat indices will likely be around 105 again
where the Extreme Heat Warning continues, with readings generally
ranging from 95 to 102 in the Heat Advisory area.

Capping warmth aloft should also help to keep the area dry into the
afternoon. The cap does partially erode late this afternoon though
dry and warm air aloft could limit updraft growth, and the potential
for thunderstorm development. A cold front currently located over
southern Quebec extending southwestward to northern Lake Michigan is
expected to move southeastward bringing showers and thunderstorms to
parts of Michigan and northern Ohio. If some of the storms make it
into northwestern PA, they have the dry air aloft will enhance the
DCAPE, resulting in a damaging wind potential, mainly north of I 80.

Any early evening convection north of PIT should quickly wane with
the loss of peak heating. Much of the remainder of the night will be
dry with the upper high in place. Although the high is expected to
remain stationary, it will begin to weaken.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
-- Changed Discussion --
KEY MESSAGES:

- Extreme Heat Warning and Heat Advisories continue through
Wednesday evening.
- Shower/storm chances increase Wednesday afternoon.
- Marginal risk for excessive rainfall Wednesday and Thursday.
- Marginal risk for severe thunderstorms Wednesday.
----------------------------------------------------------------

Another hot and humid day is expected, with the Extreme Heat Warning
and Heat Advisories continuing. The high will begin to drift
southward through the day on Wednesday, as a shortwave trough and an
associated surface cold front track along its northern periphery.
Shower and thunderstorm chances will increase through the day as the
front and shortwave approach. Surface Base CAPE is forecast to range
from 1500-2500 J/kg, though shear is expected to be minimal. Model
soundings indicate dry mid level air should be in place as well,
which will enhance a damaging wind gust potential. Weak flow is
forecast for the low to mid levels which would result in slower
storm motion. Combine this with precipitable water values of 1.8 to
2.0 inches (above the 90th percentile), and localized flash flooding
will be possible.

Convection should begin to wane in the evening as instability begins
to diminish, though showers and thunderstorm chances will continue
overnight as the surface front stalls across the area. On Thursday,
warm and humid weather will continue, though expect heat indices to
be below heat headline criteria. There will be a similar setup to
Wednesday with weak flow aloft, SB CAPE 1500-2000 J/kg, and PWATs
from 1.8-1.9 inches. A lesser potential for severe storms is
expected, however, there is a marginal chance for excessive rain due
to the slow storm motion and high moisture content. Areas that see
heavy rain on Wednesday will be especially more susceptible to flash
flooding.

Expect the showers/storms to diminish somewhat again Thursday night
with the loss of daytime heating, though elevated instability will
maintain shower/storm chances overnight with the quasi stationary
front in the vicinity.
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&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
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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 the upper high will persist over the region
through the weekend. Westerly flow aloft is expected across the
Upper Ohio Valley region. Disturbances embedded in this flow will
maintain daily shower and thunderstorm chances across the region
into early next week. These will likely be strong and diurnally
driven, with probability for precipitation peaking in the afternoon
and evening hours.

Precipitable water values are forecast to remain elevated into early
next week, though increase flow aloft Saturday into Sunday could
begin to result in a faster storm motion which could reduce the
chance for flash flooding. The potential for locally heavy rainfall
is expected to persist into early next week. A trough and surface
cold front is currently forecast to pass through on Tuesday, which
should bring an end to the active pattern.
-- End Changed Discussion --

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
High confidence in VFR through the TAF period with diurnally
driven afternoon cumulus and west wind between 8-12kts
occasionally gusting to 15kts.

There is a non-zero potential for an isolated late day
thunderstorm near FKL along an approaching storm outflow and/or
a Lake Erie breeze. Timing would favor 21z-00z before energy
wanes with sunset; however, confidence is too low of terminal
impact for TAF mention.

The combination of mostly clear skies and moist surface boundary
may allow for patchy river valley fog at terminals like
MGW/ZZV/AGC Wednesday morning near dawn.

Outlook...
Weak shortwave movement and development of a surface boundary
will foster isolated to scattered thunderstorms after 18z
Wednesday that will see activity diminish shortly after 00z.

Daily rounds of showers and thunderstorms, favoring the
afternoon/evening hours, is likely through the weekend as the
airmass remains relatively unchanged day to day. Restrictions
are likely to be limited to thunderstorm occurrence with an
occasional occurrence of patchy low level stratus/fog in
locations previously receiving heavy rain.

&&

.CLIMATE...
Daily record high maximum (left) and daily record high minimum (right)
temperatures will be in jeopardy over the next several days:


Tuesday June 24th
Pittsburgh, PA:         96F (1882)              72F (1884)
Zanesville, OH:         98F (1930)              73F (1937)
Morgantown, WV:         94F (1921, 1949)        76F (1924)
Dubois, PA:             88F (1966)              67F (2013)
Wheeling, WV:           98F (1933, 1943)        73F (1908)
New Philadelphia, OH:   94F (1964)              70F (1975)

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 8 PM EDT Wednesday for PAZ007>009-013-015-
     016-022-031-074-076>078.
     Extreme Heat Warning until 8 PM EDT Wednesday for PAZ014-020-
     021-029-073-075.
OH...Heat Advisory until 8 PM EDT Wednesday for OHZ039>041-048>050-
     057>059-068-069.
WV...Heat Advisory until 8 PM EDT Wednesday for WVZ001>004-012-021-
     509>513.

&&

$$

SYNOPSIS...WM
NEAR TERM...WM/Lupo
SHORT TERM...WM/Lupo
LONG TERM...WM/Lupo
AVIATION...Frazier
CLIMATE...MLB