Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 86, NWS Philadelphia/Mount Holly

August 2, 20265 counties in Pennsylvania; Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 2, 2026, 11:20 PM EDT for 5 counties in Pennsylvania; Warren County, New Jersey. It was in force for 4 hr. 2 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 2, 2026, 11:20 PM EDT (03:20 UTC)
Expired
Aug 3, 2026, 3:30 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Warren County, NJ, Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 118 km from the middle of the area, began a volume at 03:21 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 2, 11:22 PM EDTFLOOD2 Se Allentown, PAReport from mPING: River/Creek overflowing; Cropland/Yard/Basement Flooding.
Aug 2, 11:59 PM EDTRAIN 1.512 E Plainfield Twp, PA

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 3.3 hours before the alert went out and 213 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, Brookhaven, NY at 00:00Z on 2026-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 151 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, Brookhaven, NY at 00:00Z on 2026-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 163 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
151 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
507 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
198 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.7

Open this sounding in Storm Lab

The text

As transmitted.

071 
WGUS51 KPHI 030320
FFWPHI
NJC041-PAC011-017-077-091-095-030730-
/O.NEW.KPHI.FF.W.0086.260803T0320Z-260803T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1120 PM EDT Sun Aug 2 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southwestern Warren County in northwestern New Jersey...
  East Central Berks County in eastern Pennsylvania...
  Eastern Lehigh County in eastern Pennsylvania...
  Northampton County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...

* Until 330 AM EDT.

* At 1120 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  0.5 and 1.5 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 and automated gauges.

  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...
  Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton, 
  Quakertown, Wilson, Hellertown, Nazareth, East Greenville and Wind 
  Gap.

This includes the following highways...
	Northeast Extension between mile markers 32 and 60.
	Interstate 78 in Pennsylvania between mile markers 54 and 76.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4066 7558 4082 7544 4082 7542 4083 7542
      4083 7541 4083 7539 4083 7538 4085 7534
      4086 7532 4086 7530 4086 7529 4082 7514
      4060 7523 4033 7533 4024 7536 4030 7558

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

$$

Cooper
2 follow-up statements
774 
WGUS71 KPHI 030358
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1158 PM EDT Sun Aug 2 2026

PAC011-091-030408-
/O.CAN.KPHI.FF.W.0086.000000T0000Z-260803T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Montgomery PA-
1158 PM EDT Sun Aug 2 2026

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

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

A Flood Watch remains in effect until 1100 PM EDT Monday for 
portions of northern Delaware, New Jersey, and Pennsylvania.

&&

LAT...LON 4082 7544 4083 7538 4086 7530 4082 7514
      4033 7533 4048 7558 4066 7558

$$

NJC041-PAC017-077-095-030730-
/O.CON.KPHI.FF.W.0086.000000T0000Z-260803T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Warren NJ-Bucks PA-Lehigh PA-Northampton PA-
1158 PM EDT Sun Aug 2 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 AM EDT MONDAY FOR 
SOUTHWESTERN WARREN, EASTERN LEHIGH, NORTHAMPTON AND NORTHWESTERN 
BUCKS COUNTIES...

At 1158 PM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 
0.5 and 1.5 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 and automated gauges.

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...
  Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton, 
  Quakertown, Wilson, Hellertown, Nazareth, Wind Gap and Bath.

This includes the following highways...
	Northeast Extension between mile markers 39 and 60.
	Interstate 78 in Pennsylvania between mile markers 54 and 76.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4082 7544 4083 7538 4086 7530 4082 7514
      4033 7533 4048 7558 4066 7558

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

$$

Cooper
581 
WGUS71 KPHI 030721
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
321 AM EDT Mon Aug 3 2026

NJC041-PAC017-077-095-030731-
/O.EXP.KPHI.FF.W.0086.000000T0000Z-260803T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Warren NJ-Bucks PA-Lehigh PA-Northampton PA-
321 AM EDT Mon Aug 3 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 330 AM EDT EARLY THIS MORNING 
FOR SOUTHWESTERN WARREN, EASTERN LEHIGH, NORTHAMPTON AND 
NORTHWESTERN BUCKS 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 1100 PM EDT Monday for 
portions of northern Delaware, New Jersey, and Pennsylvania.

&&

LAT...LON 4082 7544 4083 7538 4086 7530 4082 7514
      4033 7533 4048 7558 4066 7558

$$

Cooper

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 12:05 AM EDTFlash Flood WarningPHIBucks, Monroe, Northampton3 hr
Aug 3, 3:01 AM EDTFlash Flood WarningPHIBucks, Chester, Delaware, Montgomery3 hr
Aug 3, 3:05 AM EDTSevere Thunderstorm WarningPHIBucks, Montgomery40 min
Aug 3, 4:41 AM EDTFlash Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia2 hr
Aug 3, 6:26 AM EDTAreal Flood WarningPHIBucks, Montgomery94 min
Aug 3, 7:02 AM EDTAreal Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia3 hr
Aug 3, 9:08 AM EDTFlash Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia3 hr
Aug 3, 10:36 AM EDTFlash Flood WarningPHIBucks6 hr
Aug 3, 10:44 AM EDTFlash Flood Warning Considerable damage threatPHIBucks, Philadelphia6 hr
Aug 3, 12:01 PM EDTAreal Flood WarningPHIBucks74 min
Aug 3, 1:20 PM EDTAreal Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia4 hr
Aug 3, 12:36 AM EDTSpecial Marine WarningPHI84 min
Aug 3, 2:50 AM EDTFlash Flood WarningPHIHunterdon, Mercer, Morris, Somerset4 hr
Aug 3, 5:59 AM EDTFlash Flood WarningPHIMiddlesex, Somerset4 hr
Aug 3, 8:21 AM EDTSpecial Marine WarningPHI69 min
Aug 3, 10:12 AM EDTFlash Flood WarningPHIAtlantic, Cumberland, Salem86 min
Aug 3, 1:51 PM EDTSpecial Marine WarningPHI24 min
Aug 3, 2:53 PM EDTSpecial Marine WarningPHI97 min
Aug 3, 2:57 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean27 min
Aug 3, 5:15 PM EDTSpecial Marine WarningPHI90 min

Nearby

Flash Flood Warnings in Pennsylvania, 2026Flash Flood Warnings in New Jersey, 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.