Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 148, NWS Philadelphia/Mount Holly

September 1, 2026Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 1, 2026, 6:38 PM EDT for Berks County, Pennsylvania. It was in force for 4 hr. 1 report 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
Sep 1, 2026, 6:38 PM EDT (22:38 UTC)
Expired
Sep 1, 2026, 10:25 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 148 km from the middle of the area, began a volume at 22:40 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
Sep 1, 7:29 PM EDTFLASH FLOOD1 Nnw Reading, PAMultiple vehicles stranded in high water.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.6 hours before the alert went out and 214 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 12:00Z on 2026-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 270 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 12:00Z on 2026-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 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
270 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
1350 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
101 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

390 
WGUS51 KPHI 012238
FFWPHI
PAC011-020245-
/O.NEW.KPHI.FF.W.0148.260901T2238Z-260902T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
638 PM EDT Tue Sep 1 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Berks County in eastern Pennsylvania...

* Until 1045 PM EDT.

* At 638 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 1 and 2 inches of rain
  have fallen. The expected rainfall rate is 1 to 2 inches in 1 hour.
  Additional rainfall amounts of 1 to 2 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...
  Reading, Wyomissing, Kutztown, Hamburg, Fleetwood, Sinking Spring,
  Laureldale, Womelsdorf, Wernersville, Topton, Robesonia and
  Leesport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.

&&

LAT...LON 4051 7563 4025 7604 4050 7641 4054 7617
      4058 7604 4057 7602 4064 7599 4068 7589

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

$$

MPS
3 follow-up statements
285 
WGUS71 KPHI 020018
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
818 PM EDT Tue Sep 1 2026

PAC011-020245-
/O.CON.KPHI.FF.W.0148.000000T0000Z-260902T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
818 PM EDT Tue Sep 1 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT THIS
EVENING FOR BERKS COUNTY...

At 818 PM EDT, Doppler radar indicated thunderstorms produced heavy
rain across the warned area, resulting in between 2 and 3 inches of
rain. While showers and thunderstorms tapered off, another area of
showers and thunderstorms producing rainfall rates over one inch per
hour will move into the warned area over the next hour. 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...
  Reading, Wyomissing, Kutztown, Hamburg, Fleetwood, Sinking Spring,
  Laureldale, Womelsdorf, Wernersville, Topton, Robesonia and
  Leesport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.

&&

LAT...LON 4051 7563 4025 7604 4050 7641 4054 7617
      4058 7604 4057 7602 4064 7599 4068 7589

FLASH FLOOD...RADAR INDICATED

$$

MPS
852 
WGUS71 KPHI 020149
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
949 PM EDT Tue Sep 1 2026

PAC011-020245-
/O.CON.KPHI.FF.W.0148.000000T0000Z-260902T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
949 PM EDT Tue Sep 1 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT THIS
EVENING FOR SOUTHWESTERN BERKS COUNTY...

At 949 PM EDT, Doppler radar indicated thunderstorms produced heavy
rain across the warned area. Between 2 and 3 inches of rain have
fallen. 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...
  Reading, Wyomissing, Sinking Spring, Laureldale, Womelsdorf,
  Wernersville, Robesonia, Leesport, Bernville, Strausstown, Fairview
  Hgts and Spring Ridge.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.

&&

LAT...LON 4037 7587 4025 7604 4050 7641 4050 7639
      4052 7631 4051 7630 4052 7627 4052 7623
      4053 7622 4053 7620 4054 7619 4054 7616
      4055 7612 4053 7605

FLASH FLOOD...RADAR INDICATED

$$

MPS
189 
WGUS71 KPHI 020225
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1025 PM EDT Tue Sep 1 2026

PAC011-020235-
/O.CAN.KPHI.FF.W.0148.000000T0000Z-260902T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
1025 PM EDT Tue Sep 1 2026

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN BERKS COUNTY...

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 4037 7587 4025 7604 4050 7641 4050 7639
      4052 7631 4051 7630 4052 7627 4052 7623
      4053 7622 4053 7620 4054 7619 4054 7616
      4055 7612 4053 7605

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 2:30 AM EDTHeat AdvisoryPHIBucks, Chester, Delaware, Montgomery, Philadelphia18 hr
Sep 1, 5:45 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton45 min
Sep 1, 5:50 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Northampton40 min
Sep 1, 6:09 PM EDTSevere Thunderstorm WarningPHIBerks51 min
Sep 1, 6:21 PM EDTSevere Thunderstorm WarningPHIBerks39 min
Sep 1, 6:29 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Northampton46 min
Sep 1, 6:56 PM EDTSevere Thunderstorm WarningPHIBerks, Chester49 min
Sep 1, 6:58 PM EDTSevere Thunderstorm WarningPHIBerks34 min
Sep 1, 7:13 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Lehigh, Montgomery47 min
Sep 1, 7:43 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Delaware47 min

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.