Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 140, NWS Philadelphia/Mount Holly

August 27, 2026Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 27, 2026, 8:16 PM EDT for Berks County, Pennsylvania. It was in force for 4 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
Aug 27, 2026, 8:16 PM EDT (00:16 UTC)
Expired
Aug 28, 2026, 12:15 AM 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), 140 km from the middle of the area, began a volume at 00:16 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, 0.3 hours before the alert went out and 192 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 2026-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1155 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 2026-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.19395878Sfc1 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
1155 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
1287 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

060 
WGUS51 KPHI 280016
FFWPHI
PAC011-280415-
/O.NEW.KPHI.FF.W.0140.260828T0016Z-260828T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
816 PM EDT Thu Aug 27 2026

The National Weather Service in Mount Holly has issued a

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

* Until 1215 AM EDT.

* At 816 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 1 and 2.5 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, Sinking Spring, Wernersville, Spring Ridge,
  Shillington, West Reading, Mount Penn, Mohnton, Kenhorst and St.
  Lawrence.

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.

&&

LAT...LON 4032 7615 4037 7594 4029 7578 4019 7595

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

$$

PHI
1 follow-up statement
880 
WGUS71 KPHI 280407
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
1207 AM EDT Fri Aug 28 2026

PAC011-280417-
/O.EXP.KPHI.FF.W.0140.000000T0000Z-260828T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
1207 AM EDT Fri Aug 28 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 1215 AM EDT EARLY THIS MORNING
FOR SOUTH CENTRAL BERKS COUNTY...

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 400 AM EDT for portions of New
Jersey and Pennsylvania.

&&

LAT...LON 4032 7615 4037 7594 4029 7578 4019 7595

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 8:09 PM EDTAreal Flood WarningPHIBucks, Montgomery5 hr
Aug 27, 8:40 PM EDTSevere Thunderstorm WarningPHIBerks50 min
Aug 27, 9:09 PM EDTAreal Flood WarningPHIBucks, Chester, Montgomery4 hr
Aug 27, 9:21 PM EDTFlash Flood WarningPHIBerks3 hr
Aug 27, 9:32 PM EDTRiver Flood WarningPHIBucks6 hr
Aug 27, 10:22 PM EDTSevere Thunderstorm WarningPHIBerks, Chester38 min
Aug 27, 10:36 PM EDTFlash Flood WarningPHIBerks, Chester, Montgomery3 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.