Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 99, NWS Philadelphia/Mount Holly

August 5, 2026Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 5, 2026, 2:17 PM EDT for Bucks County, Montgomery County, Pennsylvania. 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 5, 2026, 2:17 PM EDT (18:17 UTC)
Expired
Aug 5, 2026, 6:15 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 18:19 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 5, 3:10 PM EDTFLASH FLOOD1 Ssw Warminster, PASeveral areas of flooding on County Line Road.
Aug 5, 3:15 PM EDTFLASH FLOOD2 Nnw Wrightstown Twp, PAPine Lane is flooded and impassable.

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 12:00Z, 6.3 hours before the alert went out and 206 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 12:00Z on 2026-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2026-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1372 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
-42 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

681 
WGUS51 KPHI 051817
FFWPHI
PAC017-091-052215-
/O.NEW.KPHI.FF.W.0099.260805T1817Z-260805T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
217 PM EDT Wed Aug 5 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southeastern Bucks County in southeastern Pennsylvania...
  Southeastern Montgomery County in southeastern Pennsylvania...

* Until 615 PM EDT.

* At 217 PM EDT, Doppler radar indicated heavy rain beginning to 
  move into the warned area. The expected rainfall rate is 0.5 to 1 
  inch in 30 minutes. Rainfall amounts up to 2 inches are possible 
  in the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by heavy rain.

  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...
  Philadelphia, Lansdale, East Norriton, Doylestown, Hatboro, 
  Ambler, Chalfont, New Hope, Yardley, Newtown, Abington and 
  Langhorne.

This includes the following highways...
	Northeast Extension between mile markers 21 and 28.
	Pennsylvania Turnpike between mile markers 333 and 349.

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.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4027 7523 4036 7497 4021 7480 4018 7489
      4009 7522 4009 7523 4007 7528 4022 7534

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...0.5-1 INCH IN 30 MINUTES

$$

Fitzsimmons
2 follow-up statements
238 
WGUS71 KPHI 052013
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
413 PM EDT Wed Aug 5 2026

PAC017-091-052215-
/O.CON.KPHI.FF.W.0099.000000T0000Z-260805T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-
413 PM EDT Wed Aug 5 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM EDT THIS 
EVENING FOR SOUTHEASTERN BUCKS AND SOUTHEASTERN MONTGOMERY 
COUNTIES...

At 413 PM EDT, Doppler radar and automated rain gauges indicated 
rain amounts of 1 to 2 inches have fallen within portions of the 
warned area leading to reports of flash flooding. Additional 
rainfall amounts up to 1 inch are possible in the warned area as 
more heavy rainfall moves through late this afternoon. 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...
  Philadelphia, Lansdale, East Norriton, Doylestown, Hatboro, 
  Ambler, Chalfont, New Hope, Yardley, Newtown, Abington and 
  Langhorne.

This includes the following highways...
	Northeast Extension between mile markers 21 and 28.
	Pennsylvania Turnpike between mile markers 333 and 348.

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.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4027 7523 4036 7497 4021 7480 4018 7489
      4009 7522 4009 7523 4007 7528 4022 7534

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Fitzsimmons
707 
WGUS71 KPHI 052205
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
605 PM EDT Wed Aug 5 2026

PAC017-091-052215-
/O.EXP.KPHI.FF.W.0099.000000T0000Z-260805T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-
605 PM EDT Wed Aug 5 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 615 PM EDT THIS EVENING FOR 
SOUTHEASTERN BUCKS AND SOUTHEASTERN 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.

&&

LAT...LON 4027 7523 4036 7497 4021 7480 4018 7489
      4009 7522 4009 7523 4007 7528 4022 7534

$$

Fitzsimmons

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 12:58 PM EDTFlash Flood WarningPHIBucks, Montgomery, Philadelphia6 hr
Aug 5, 1:13 PM EDTFlash Flood WarningPHIDelaware, Montgomery, Philadelphia5 hr
Aug 5, 1:23 PM EDTFlash Flood WarningPHIBucks4 hr
Aug 5, 1:50 PM EDTHeat AdvisoryPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more3 days
Aug 5, 2:50 PM EDTFlash Flood Warning Considerable damage threatPHIBucks4 hr
Aug 5, 3:33 PM EDTFlash Flood WarningPHIBucks86 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.