Flash Flood Warning 22, NWS Pittsburgh, PA

Area Forecast Discussion
National Weather Service Pittsburgh PA
123 PM EDT Sun Jun 28 2026

.WHAT HAS CHANGED...
Low but non-zero chance for isolated flash flooding south of
Pittsburgh this afternoon and evening. Increasing confidence in
dangerous heat mid to late this upcoming work week. Updated for
the 18z TAF issuance.

&&

.KEY MESSAGES...
1) Non-zero potential for heavy rain and flooding this
afternoon/evening mainly south of Pittsburgh.

2) Increasing confidence in dangerous heat mid to late week,
followed by potential for strong thunderstorms next weekend.

&&

.DISCUSSION...
KEY MESSAGE 1...
A weak boundary that has been stalled across the southern
portion of the forecast area the past few days lifts north
slightly to around or just north of the I-70 corridor through
this evening. Slow-moving showers and possibly a thunderstorm or
two are already developing along the front. With this activity
expected to stall and then shift back southeastward later this
evening, some locations mainly across extreme SW PA and northern
WV could see prolonged periods of moderate to, at times, heavy
rainfall. As a result, there is some potential for localized
flash flooding issues, especially in areas that have already
received notable rainfall over recent days. Latest 1-hr FFG
is roughly 0.9 to 1.25 inches over that area and 3-hr FFG is
1.5 to 2.25 inches. It is certainly feasible that a location or
two could see these thresholds met if showers become more
convective with additional daytime heating and given PWATs above
the 90th percentile on this morning's 12Z PIT sounding. Still,
coverage of the heavier rain rates is scattered and latest 1-hr
QPE is estimated around 0.5 to 0.75 inches, so opting not to
issue a Flood Watch at this time. This activity should wane
after sunset with the loss of daytime heating.

KEY MESSAGE 2...
The story of the upcoming work week is hot weather areawide. A
mid-level ridge of high pressure builds across the Ohio Valley
and brings the hottest temperatures of the year so far, not
record breaking with respect to afternoon highs but a high
probability of breaking warm overnight lows at several sites
Wednesday - Friday. The hottest weather still looks to be
Wednesday and Thursday where widespread mid and upper 90s will
be common, particularly in urban areas. Heat Advisories are
likely to be issued across much of the area during that time as
apparent temperatures climb to the 100F to 104F range. Guidance
continues to be bullish on moisture and maintains upper 60s to
mid 70s dewpoints even during afternoon hours, leading to heat
indices climbing above 105F in some spots. While that is not out
of the realm of possibility (particularly in urban areas
located right along major rivers), historically speaking it is
difficult for this region to see temperatures climb into the mid
90s with dewpoints that high (e.g., Pittsburgh has seen a
temperature of 95F and dewpoint of 75F or greater only 4 times
since 1952). Thus, the current line of thinking is that the
modeled dewpoints are a tad high and will end up verifying in
perhaps the mid 60s during peak heating each afternoon, which
would help keep widespread apparent temperatures below 105F and
thus preclude the need for Extreme Heat Watches/Warnings.

In addition, heat risk will be in the major category (level 3
out of 4) with an extreme heat risk (level 4 out of 4) for the
lower elevations Wednesday and Thursday. However, since 2005,
Pittsburgh has not verified an extreme heat risk, so we will see
if the dewpoint forecast trends a smidge lower, which will have
an impact on this index. A quick refresher, NWS heat risk is a
color-numeric based index that uses high resolution weather,
climate, and CDC heat-health data to identify potentially
dangerous heat.

It is also good to point out that a big driver of impacts to
people in heat waves are the overnight low temperatures. This is
because people can't cool off at night especially those without
air conditioners. If you have friends or family that are
sensitive to heat, elderly, or without AC, please check on them
throughout the week.

Machine learning models are all pointing to an uptick in
thunderstorm activity and potential severe weather Friday into
next weekend across the region. Granted this is far down the
road, but when we have a heat wave, typically there is a round
of severe weather that ends it with the ridge flattening and the
westerlies driving a weather system through. As of now, the
probabilities are largely in the 15%-30% range.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Fog has broken across the region and gradual improvements in
CIGs are underway. A line of showers is slowly creeping NE at
this time. Embedded thunderstorms are possible in this line
later this afternoon. These showers and storms will continue to
slowly move NEward before slowing, stalling and then shifting
slowly to the SE this evening and overnight. Isolated heavy
downpours are possible in this activity. Light and variable
winds continue through the afternoon before abating overnight.

Clouds are expected to clear this evening. Areas that see
renewed rainfall likely greatly increase their chance for fog
again tonight into tomorrow but chances of fog impacts look
probable for many ports again already.

Outlook... High pressure builds into the area by Mon, leading to
higher temperatures and what appears most likely to be a dry
forecast through at least the first half of the week. However, there
is some guidance that continues to suggest daily thunderstorm
chances linger, though coverage would be isolated and therefore the
probability of impacts to area terminals remains low (roughly
10%).

&&

.CLIMATE...
Record High Temperatures for 06/30 (Tue):
New Philadelphia OH  Forecast: 95 Record: 93/1964

Record High Minimum Temperatures for 06/30 (Tue):
New Philadelphia OH Forecast: 72 Record: 71/1991
Pittsburgh PA 		Forecast: 71 Record: 74/1933
Zanesville OH       Forecast: 72 Record: 74/1934

Record High Temperatures for 07/01 (Wed):
New Philadelphia OH Forecast: 96 Record: 96/1991

Record High Minimum Temperatures for 07/01 (Wed):
Wheeling WV         Forecast:  75  Record: 75/1901
Morgantown WV       Forecast:  74  Record: 74/1901
New Philadelphia OH Forecast:  76  Record: 71/2014
Zanesville OH       Forecast:  74  Record: 73/1913

Record High Temperatures for 07/02 (Thu):
New Philadelphia    Forecast:  96  Record: 95/1966
Pittsburgh PA       Forecast:  95  Record: 97/1931

Record High Minimum Temperatures for 07/02 (Thu):
Wheeling WV         Forecast:  76  Record: 73/2018
Morgantown WV       Forecast:  74  Record: 74/1901
New Philadelphia OH Forecast:  76  Record: 73/2018
Pittsburgh PA       Forecast:  76  Record: 76/1903
Zanesville OH       Forecast:  75  Record: 71/1903

Record High Minimum Temperatures for 07/03 (Fri):
Wheeling WV         Forecast:  76  Record: 77/1903
Morgantown WV       Forecast:  75  Record: 74/1901
New Philadelphia OH Forecast:  77  Record: 71/1991
Pittsburgh PA       Forecast:  76  Record: 76/1898
Zanesville OH       Forecast:  76  Record: 78/1935

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

DISCUSSION...Cermak/Shallenberger
AVIATION...AK

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
103 PM EDT Sun Jun 28 2026

OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>022-029-
031-073>078-WVZ001>004-012-021-509>514-291715-
Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH-
Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Forest-
Lawrence-Butler-Clarion-Jefferson PA-Beaver-Allegheny-Armstrong-
Washington-Greene-Westmoreland-Higher Elevations of Westmoreland-
Fayette-Higher Elevations of Fayette-Indiana-
Higher Elevations of Indiana-Hancock-Brooke-Ohio-Marshall-Wetzel-
Marion-Monongalia-
Ridges of Eastern Monongalia and Northwestern Preston-Preston-
Eastern Preston-Western Tucker-Eastern Tucker-
103 PM EDT Sun Jun 28 2026

This Hazardous Weather Outlook is for east central Ohio, western
Pennsylvania, and northern West Virginia.

.DAY ONE...This afternoon and tonight.

Isolated flash flooding will be possible primarily south of
Pittsburgh this afternoon and evening as slow-moving showers and
thunderstorms bring brief downpours to already saturated areas.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Heat will begin to build in the lowlands Tuesday through Friday.
Highs will be in the lower to mid 90s and heat indices of 100 to 105
possible. A heat advisory will likely be needed for several days
mid to late week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

TC