Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 113, NWS Pittsburgh, PA

August 16, 2026Clarion County, Jefferson County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Aug 16, 2026, 7:17 PM EDT for Clarion County, Jefferson County, Pennsylvania. It was in force for 3 hr. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 16, 2026, 7:17 PM EDT (23:17 UTC)
Expired
Aug 16, 2026, 10:15 PM EDT
In force
3 hr
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon
Flood severity
None

Counties Clarion County, PA, Jefferson County, PA

The radar

The State College radar (KCCX), 83 km from the middle of the area, began a volume at 23:20 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 16, 7:42 PM EDTFLASH FLOOD2 Ese Brookville, PAReports of roadway flooding along US322 near Sulgar Rd.
Aug 16, 8:00 PM EDTFLASH FLOOD5 Wnw Reynoldsville, PAReport of a flooded roadway along US322 near the intersection with Fuller Rd.
Aug 16, 8:37 PM EDTRAIN 2.31Brookville, PAtwo inches came in the last two hours. 24 hour rainfall total.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this flash flood warning; the first came 25 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 11.3 hours before the alert went out and 126 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2026-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 51 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 12:00Z on 2026-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
51 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
636 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

191 
WGUS51 KPBZ 162317
FFWPBZ
PAC031-065-170215-
/O.NEW.KPBZ.FF.W.0113.260816T2317Z-260817T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pittsburgh PA
717 PM EDT Sun Aug 16 2026

The National Weather Service in Pittsburgh has issued a

* Flash Flood Warning for...
  East Central Clarion County in west central Pennsylvania...
  Central Jefferson PA County in west central Pennsylvania...

* Until 1015 PM EDT.

* At 717 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to 0.5 inches of rain have
  fallen. The expected rainfall rate is 1 to 2 inches in 1 hour.
  Additional rainfall amounts of 1 to 3 inches are possible in the
  warned area. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flash flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other poor
           drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Brookville, Reynoldsville, Sykesville, Falls Creek, Summerville,
  Corsica and Knox-Dale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 4105 7923 4125 7922 4124 7874 4123 7874
      4123 7871 4120 7871 4120 7877 4113 7880
      4100 7880 4104 7921 4105 7921

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

AK
2 follow-up statements
515 
WGUS71 KPBZ 170004
FFSPBZ

Flash Flood Statement
National Weather Service Pittsburgh PA
804 PM EDT Sun Aug 16 2026

PAC031-065-170215-
/O.CON.KPBZ.FF.W.0113.000000T0000Z-260817T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clarion PA-Jefferson PA-
804 PM EDT Sun Aug 16 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM EDT THIS
EVENING FOR EAST CENTRAL CLARION AND CENTRAL JEFFERSON PA COUNTIES...

At 804 PM EDT, local law enforcement reported flooded roadways along
US322 near Brookville. Between 0.5 and 1.5 inches of rain have
fallen. The expected rainfall rate is 1 inch in 1 hour. Additional
rainfall amounts up to 1 inch are possible in the warned area. Flash
flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Brookville, Reynoldsville, Sykesville, Falls Creek, Summerville,
  Corsica and Knox-Dale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4105 7923 4125 7922 4124 7874 4123 7874
      4123 7871 4120 7871 4120 7877 4113 7880
      4100 7880 4104 7921 4105 7921

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL RATE...1 INCH IN 1 HOUR

$$

AK
633 
WGUS71 KPBZ 170206
FFSPBZ

Flash Flood Statement
National Weather Service Pittsburgh PA
1006 PM EDT Sun Aug 16 2026

PAC031-065-170216-
/O.EXP.KPBZ.FF.W.0113.000000T0000Z-260817T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clarion PA-Jefferson PA-
1006 PM EDT Sun Aug 16 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 1015 PM EDT THIS EVENING FOR
EAST CENTRAL CLARION AND CENTRAL JEFFERSON PA COUNTIES...

The heavy rain has ended. Flood waters have receded. Flooding is no
longer expected to pose a threat. Please continue to heed remaining
road closures.

&&

LAT...LON 4105 7923 4125 7922 4124 7874 4123 7874
      4123 7871 4120 7871 4120 7877 4113 7880
      4100 7880 4104 7921 4105 7921

$$

AK

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Pittsburgh, PA wrote its last area forecast discussion before this flash flood warning went out at Aug 16, 12:50 PM EDT, 6 hours 27 minutes earlier. Its key messages:

  • 1)Severe weather and flash flooding risks continue this afternoon and evening with renewed thunderstorm development. 2) After lingering showers dissipate Monday, there is fairly high confidence in dry weather until Wednesday/Thursday, when the next front arrives.
Area forecast discussion, Aug 16, 12:50 PM EDT, 6 hours 27 minutes before
Area Forecast Discussion
National Weather Service Pittsburgh PA
1250 PM EDT Sun Aug 16 2026

.WHAT HAS CHANGED...
There is higher confidence in the potential for severe
thunderstorms this afternoon, given clearing skies to the west
allowing for increased instability. Beyond this evening, little
change was made to the forecast.

&&

.KEY MESSAGES...
1)Severe weather and flash flooding risks continue this
afternoon and evening with renewed thunderstorm development.

2) After lingering showers dissipate Monday, there is fairly
high confidence in dry weather until Wednesday/Thursday, when
the next front arrives.

&&

.DISCUSSION...
KEY MESSAGE 1...
The region remains in a relative lull of activity between
overnight/early morning activity and developing convection to
the west, where a couple of Severe Thunderstorm Warnings are
already in effect. The new activity is associated with a vort
max/MCV over northwest Ohio. Ahead of this, a good deal of
sunshine is allowing for a buildup of instability, and the HREF
suggests that 1500-2500 J/kg of surface-based CAPE is likely by
18Z, mainly south of I-80. Other convective parameters look best
from I-80 on south, roughly matching with the SPC Slight Risk
area. In particular, a pocket of 25-30 knots of 0-6km shear is
most likely in this region, supporting multicells with mainly a
damaging gust potential where cold pools help consolidate into
short lines. Lengthening low-level hodographs and sufficient
0-1km SRH continue to suggest a low-end tornado threat for any
ESE-moving storms.

Along with this the threat of flash flooding will continue to be
monitored, especially in areas that got heavier rain overnight.
This includes areas in eastern Ohio south of I-70, as well as a
strip extending from New Philadelphia ENE towards Butler County.
Although storms should be fairly progressive overall, the
environment remains highly supportive for efficient rainfall
production. The 12Z KPIT sounding recorded a precipitable water
measurement of 2.15 inches, which is the 9th-highest recorded
at the site since 1952. 2+ inch values remain in place through
this evening, along with 11k to 13k warm-cloud depths. The Flood
Watch will be maintained through tonight.

KEY MESSAGE 2...
Most of the convection should pull off to the east by 02Z-03Z,
although a few showers/storms may linger behind the main line as
another shortwave trough crosses in the mid-level zonal flow.
One last ripple in that flow crosses on Monday, leading to
showers and storms mainly south of Pittsburgh. Convective
parameters are unfavorable for severe weather with this
activity. Also, declining precipitable water values point to a
decreasing risk for heavy rainfall. The Flood Watch expires at 8
AM Monday, and an extension may not be needed.

High pressure building in from the Great Lakes should end
precipitation by Mon evening. Dry weather is then favored until
Wednesday, when the next front could potentially arrive,
although this timing could change. At this time, severe weather
and flooding risks appear low with this system, as supported by
longer-range machine learning guidance.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Mainly MVFR cigs continue this afternoon ahead of an approaching
prefrontal trough. A broken line of thunderstorms is expected to
track east across the region this afternoon and evening along
the prefrontal trough, with IFR restrictions. Some storms could
contain damaging wind and heavy rainfall. Included a tempo
mention in the tafs for the most likely time of arrival. Expect
a gradual deterioration back to IFR tonight with low level
moisture in place.

The surface cold front is progged to track across the region
Monday. Expect a gradual improvement in cig heights through the
day with mixing and some dry advection after FROPA. Airports
from near PIT and south could see a few afternoon showers or a
thunderstorm as this front crosses.

Outlook...
Other than early morning fog, VFR is then expected through
early Wednesday under high pressure. Restriction and
shower/thunderstorm chances return Wednesday and Wednesday night
with the approach and passage of a cold front. VFR returns
Thursday and Friday under high pressure.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch through Monday morning for PAZ020-021-029-031-
     073>076.
OH...Flood Watch through Monday morning for OHZ039>041-048>050-
     057>059-068-069.
WV...Flood Watch through Monday morning for WVZ001>004-012-021-
     509>514.

&&

DISCUSSION...CL
AVIATION...WM
Hazardous weather outlook, Aug 16, 6:11 PM EDT, 1 hour 6 minutes before
Hazardous Weather Outlook
National Weather Service Pittsburgh PA
611 PM EDT Sun Aug 16 2026

OHZ039>041-048>050-057>059-068-069-PAZ020-021-029-031-073>076-
WVZ001>004-012-021-509>514-172215-
Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH-
Muskingum-Guernsey-Belmont-Noble-Monroe-Beaver-Allegheny-Washington-
Greene-Westmoreland-Higher Elevations of Westmoreland-Fayette-
Higher Elevations of Fayette-Hancock-Brooke-Ohio-Marshall-Wetzel-
Marion-Monongalia-
Ridges of Eastern Monongalia and Northwestern Preston-Preston-
Eastern Preston-Western Tucker-Eastern Tucker-
611 PM EDT Sun Aug 16 2026

...FLOOD WATCH IN EFFECT THROUGH MONDAY MORNING...

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

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

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

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PAZ007>009-013>016-022-077-078-172215-
Mercer-Venango-Forest-Lawrence-Butler-Clarion-Jefferson PA-Armstrong-
Indiana-Higher Elevations of Indiana-
611 PM EDT Sun Aug 16 2026

This Hazardous Weather Outlook is for western Pennsylvania.

.DAY ONE...Tonight.

There is still some potential for isolated instances of heavy
rainfall through the night with additional thunderstorms, along with
a few strong wind gusts.

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

A few showers and thunderstorms could produce some heavy rainfall on
Monday morning.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

In the hours before

Local storm report, Aug 16, 6:03 PM EDT, 1 hour 14 minutes before
Preliminary Local Storm Report
National Weather Service Pittsburgh PA
603 PM EDT Sun Aug 16 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0259 PM     Tstm Wnd Dmg     Cadiz                   40.27N 80.99W
08/16/2026                   Harrison           OH   Public

            Branches down.

&&

Kramar
Local storm report, Aug 16, 6:17 PM EDT, 1 hour before
Preliminary Local Storm Report
National Weather Service Pittsburgh PA
617 PM EDT Sun Aug 16 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0359 PM     Tstm Wnd Dmg     3 SSE Lower Burrell     40.54N 79.68W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0408 PM     Tstm Wnd Dmg     2 WSW Municipality of M 40.43N 79.68W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0410 PM     Tstm Wnd Dmg     3 SSW Delmont           40.38N 79.59W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0414 PM     Tstm Wnd Dmg     East Vandergrift        40.60N 79.57W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0415 PM     Tstm Wnd Dmg     1 E Jeannette           40.33N 79.59W
08/16/2026                   Westmoreland       PA   911 Call Center

            down wires.

0416 PM     Tstm Wnd Dmg     1 SSE Madison           40.23N 79.67W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0418 PM     Tstm Wnd Dmg     3 W Hunker              40.20N 79.67W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0419 PM     Tstm Wnd Dmg     2 NW Calumet-Norvelt    40.22N 79.52W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0422 PM     Tstm Wnd Dmg     2 NNW New Alexandria    40.42N 79.43W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0423 PM     Tstm Wnd Dmg     2 NNE New Alexandria    40.43N 79.41W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0423 PM     Tstm Wnd Dmg     2 NNW New Alexandria    40.42N 79.43W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

0427 PM     Tstm Wnd Dmg     1 NE Youngstown         40.29N 79.36W
08/16/2026                   Westmoreland       PA   911 Call Center

            down trees.

&&

98
Local storm report, Aug 16, 6:19 PM EDT, 58 minutes before
Preliminary Local Storm Report
National Weather Service Pittsburgh PA
619 PM EDT Sun Aug 16 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0341 PM     Tstm Wnd Dmg     2 WNW Reserve Township  40.49N 80.02W
08/16/2026                   Allegheny          PA   Public

            large limbs down on Perrysville ave.

&&

98
Local storm report, Aug 16, 6:53 PM EDT, 24 minutes before
Preliminary Local Storm Report
National Weather Service Pittsburgh PA
653 PM EDT Sun Aug 16 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0433 PM     Tstm Wnd Dmg     3 ENE Brandonville      39.68N 79.57W
08/16/2026                   Preston            WV   911 Call Center

            down trees.

&&

98
Local storm report, Aug 16, 6:55 PM EDT, 22 minutes before
Preliminary Local Storm Report
National Weather Service Pittsburgh PA
655 PM EDT Sun Aug 16 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0435 PM     Tstm Wnd Dmg     8 ESE Fairchance        39.77N 79.63W
08/16/2026                   Fayette            PA   911 Call Center

            trees down.

&&

98
Local storm report, Aug 16, 6:59 PM EDT, 18 minutes before
Preliminary Local Storm Report
National Weather Service Pittsburgh PA
659 PM EDT Sun Aug 16 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0659 PM     Flash Flood      4 WNW Kennerdell        41.30N 79.91W
08/16/2026                   Venango            PA   911 Call Center

            OLD ROUTE 8 FLOODING FROM TWIN OAKS RD S
            DOWN TO THE TWP BUILDINGFLOOD.

&&

98

The office that day

Everything else NWS Pittsburgh, PA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 16, 2:30 PM EDTSevere Thunderstorm WarningPBZBeaver, Lawrence, Washington45 min
Aug 16, 3:00 PM EDTTornado WarningPBZBeaver18 min
Aug 16, 3:05 PM EDTSevere Thunderstorm WarningPBZAllegheny, Beaver, Butler, Lawrence, Washington40 min
Aug 16, 3:22 PM EDTTornado WarningPBZBeaver, Butler23 min
Aug 16, 3:25 PM EDTSevere Thunderstorm WarningPBZGreene, Washington50 min
Aug 16, 3:41 PM EDTSevere Thunderstorm WarningPBZAllegheny, Armstrong, Beaver, Butler, Lawrence, Westmoreland49 min
Aug 16, 4:05 PM EDTSevere Thunderstorm WarningPBZFayette, Greene40 min
Aug 16, 4:15 PM EDTFlash Flood WarningPBZWashington5 hr
Aug 16, 4:15 PM EDTSevere Thunderstorm WarningPBZArmstrong, Butler, Indiana, Westmoreland45 min
Aug 16, 4:34 PM EDTTornado WarningPBZIndiana, Westmoreland26 min
Aug 16, 4:40 PM EDTSevere Thunderstorm WarningPBZFayette, Westmoreland20 min
Aug 16, 4:44 PM EDTSevere Thunderstorm WarningPBZFayette16 min
Aug 16, 6:39 PM EDTFlash Flood WarningPBZClarion, Venango5 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2026Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.