Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 82, NWS Philadelphia/Mount Holly

July 28, 2026Berks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 28, 2026, 9:03 PM EDT for Berks County, Montgomery County, Pennsylvania. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 28, 2026, 9:03 PM EDT (01:03 UTC)
Expired
Jul 29, 2026, 12:06 AM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Berks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 108 km from the middle of the area, began a volume at 01:03 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.1 hours before the alert went out and 222 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, Washington/Dulle, VA at 00:00Z on 2026-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 324 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2026-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.193958Sfc1 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
324 J/kg
Mixed-layer CIN
-127 J/kg
Mixed-layer LCL
1059 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

893 
WGUS51 KPHI 290103
FFWPHI
PAC011-091-290500-
/O.NEW.KPHI.FF.W.0082.260729T0103Z-260729T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
903 PM EDT Tue Jul 28 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  East Central Berks County in eastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...

* Until 100 AM EDT.

* At 903 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 2.5 inches of 
  rain have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts up to 1 inch are possible in the 
  warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets, and underpasses as well as other
           drainage and low lying areas.

* Some locations that may experience flash flooding include...
  Collegeville, Trappe, Schwenksville, Bally, Bechtelsville, 
  Gilbertsville, Spring Mount, Skippack, Boyertown, Pottsgrove, 
  Sanatoga and Halfway House.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4049 7560 4044 7552 4039 7557 4024 7536
      4018 7547 4030 7565 4037 7574

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

$$

AKL
2 follow-up statements
540 
WGUS71 KPHI 290256 RRA
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1056 PM EDT Tue Jul 28 2026

PAC011-091-290500-
/O.CON.KPHI.FF.W.0082.000000T0000Z-260729T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Montgomery PA-
1056 PM EDT Tue Jul 28 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1 AM EDT WEDNESDAY 
FOR EAST CENTRAL BERKS AND NORTHWESTERN MONTGOMERY COUNTIES...

At 1056 PM EDT, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Between 2 and 3 inches of rain 
have fallen. Flooding impacts will continue, but no additional 
rainfall is expected. Flash flooding is ongoing or expected to begin 
shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flooding of small creeks and streams, urban areas,
         highways, streets, and underpasses as well as other
         drainage and low lying areas.

Some locations that may experience flash flooding include...
  Collegeville, Trappe, Schwenksville, Bally, Bechtelsville, 
  Gilbertsville, Spring Mount, Skippack, Boyertown, Pottsgrove, 
  Sanatoga and Halfway House.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4049 7560 4044 7552 4039 7557 4024 7536
      4018 7547 4030 7565 4037 7574

FLASH FLOOD...RADAR INDICATED

$$

Hoeflich
752 
WGUS71 KPHI 290406
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1206 AM EDT Wed Jul 29 2026

PAC011-091-290416-
/O.CAN.KPHI.FF.W.0082.000000T0000Z-260729T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Montgomery PA-
1206 AM EDT Wed Jul 29 2026

...FLASH FLOOD WARNING IS CANCELLED FOR EAST CENTRAL BERKS AND 
NORTHWESTERN MONTGOMERY COUNTIES...

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

A Flood Watch remains in effect until 200 PM EDT Wednesday for 
portions of northern Delaware, New Jersey, and Pennsylvania.

&&

LAT...LON 4049 7560 4044 7552 4039 7557 4024 7536
      4018 7547 4030 7565 4037 7574

$$

Hoeflich

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 28, 8:10 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery39 min
Jul 28, 11:36 PM EDTAreal Flood WarningPHIBucks, Lehigh, Northampton4 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.