Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 78, NWS Philadelphia/Mount Holly

July 28, 2026Bucks County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 28, 2026, 6:56 PM EDT for Bucks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 5 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: Jul 28, 2026, 6:56 PM EDT (22:56 UTC)
Expired: Jul 29, 2026, 12:00 AM EDT
In force: 5 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 109 km from the middle of the area, began a volume at 22:57 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

Time	Report	Where	Remark
Jul 28, 9:02 PM EDT	FLASH FLOOD	1 Sw Quakertown, PA	Ten residences on the 100 block of Washington Court in Quakertown Borough were evacuated due to basement flooding.

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, 10.9 hours before the alert went out and 219 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1266 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 637 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 63 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

591 
WGUS51 KPHI 282256
FFWPHI
PAC017-077-095-290300-
/O.NEW.KPHI.FF.W.0078.260728T2256Z-260729T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southeastern Lehigh County in eastern Pennsylvania...
  South Central Northampton County in eastern Pennsylvania...
  West Central Bucks County in southeastern Pennsylvania...

* Until 1100 PM EDT.

* At 656 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 1.5 to 2.5 inches 
  in 1 hour. Additional rainfall amounts of 0.5 to 1.5 inches 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...
  Allentown, Bethlehem, Emmaus, Quakertown, Zionsville, Lehigh 
  University, Ancient Oaks, Fountain Hill, Macungie, Coopersburg, 
  Alburtis and Richlandtown.

This includes the following highways...
	Northeast Extension between mile markers 40 and 55.
	Interstate 78 in Pennsylvania between mile markers 56 and 63...and
	near mile marker 65.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4066 7541 4060 7535 4054 7545 4046 7530
      4038 7541 4051 7563

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1.5-2.5 INCHES IN 1 HOUR

$$

AKL

3 follow-up statements

465 
WGUS71 KPHI 290136
FFSPHI

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

PAC017-077-095-290300-
/O.CON.KPHI.FF.W.0078.000000T0000Z-260729T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Lehigh PA-Northampton PA-
936 PM EDT Tue Jul 28 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM EDT THIS 
EVENING FOR SOUTHEASTERN LEHIGH, SOUTH CENTRAL NORTHAMPTON AND WEST 
CENTRAL BUCKS COUNTIES...

At 936 PM EDT, emergency management reported residences along 
Washington Court in Quakertown were evacuated due to basement 
flooding. Between 3 and 5 inches of rain have fallen. Flash flooding 
is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Emergency management reported.

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, Bethlehem, Emmaus, Quakertown, Zionsville, Lehigh 
  University, Ancient Oaks, Fountain Hill, Macungie, Coopersburg, 
  Alburtis and Richlandtown.

This includes the following highways...
	Northeast Extension between mile markers 40 and 55.
	Interstate 78 in Pennsylvania between mile markers 56 and 63...and
	between mile markers 65 and 66.

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 4066 7541 4060 7535 4054 7545 4046 7530
      4038 7541 4051 7563

FLASH FLOOD...OBSERVED

$$

AKL

999 
WGUS51 KPHI 290253
FFWPHI
PAC017-077-095-290400-
/O.EXT.KPHI.FF.W.0078.000000T0000Z-260729T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1053 PM EDT Tue Jul 28 2026

The National Weather Service in Mount Holly has extended the

* Flash Flood Warning for...
  Southeastern Lehigh County in eastern Pennsylvania...
  South Central Northampton County in eastern Pennsylvania...
  West Central Bucks County in southeastern Pennsylvania...

* Until midnight EDT tonight.

* At 1053 PM EDT, Doppler radar indicated earlier thunderstorms 
  produced heavy rain across the warned area. Between 3 and 5 inches 
  of rain have fallen. 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...
  Allentown, Bethlehem, Emmaus, Quakertown, Zionsville, Lehigh 
  University, Ancient Oaks, Fountain Hill, Macungie, Coopersburg, 
  Alburtis and Richlandtown.

This includes the following highways...
	Northeast Extension between mile markers 40 and 55.
	Interstate 78 in Pennsylvania between mile markers 56 and 63...and
	between mile markers 65 and 66.

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 4066 7541 4060 7535 4054 7545 4046 7530
      4038 7541 4051 7563

FLASH FLOOD...RADAR INDICATED

$$

AKL

791 
WGUS71 KPHI 290354
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1154 PM EDT Tue Jul 28 2026

PAC017-077-095-290404-
/O.EXP.KPHI.FF.W.0078.000000T0000Z-260729T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Lehigh PA-Northampton PA-
1154 PM EDT Tue Jul 28 2026

...FLASH FLOOD WARNING WILL EXPIRE AT MIDNIGHT EDT TONIGHT FOR 
SOUTHEASTERN LEHIGH, SOUTH CENTRAL NORTHAMPTON AND WEST CENTRAL 
BUCKS COUNTIES...

The heavy rain has ended. Flash flooding is no longer expected to 
pose a widespread threat. Areas of standing water, flooded creeks, 
and flooded streams will continue through the night. A new Flood 
Warning was issued to cover that threat. Refer to that bulletin for 
the updated information. Please continue to heed remaining road 
closures.

A Flood Watch remains in effect until 800 PM EDT Wednesday for 
portions of New Jersey and Pennsylvania.

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

&&

LAT...LON 4066 7541 4060 7535 4054 7545 4046 7530
      4038 7541 4051 7563

$$

Hoeflich

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 8:01 PM EDT	Severe Thunderstorm Warning	PHI	Chester	23 min
Jul 28, 1:02 PM EDT	Flash Flood Warning	PHI	Lehigh, Monroe, Northampton	4 hr
Jul 28, 1:22 PM EDT	Severe Thunderstorm Warning	PHI	Lehigh, Northampton	38 min
Jul 28, 1:31 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	44 min
Jul 28, 1:49 PM EDT	Tornado Warning	PHI	Monroe, Northampton	26 min
Jul 28, 2:15 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	45 min
Jul 28, 5:08 PM EDT	Severe Thunderstorm Warning	PHI	Lehigh, Northampton	15 min
Jul 28, 5:22 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	34 min
Jul 28, 5:29 PM EDT	Severe Thunderstorm Warning	PHI	Chester	61 min
Jul 28, 5:47 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Northampton	43 min
Jul 28, 5:55 PM EDT	Flash Flood Warning	PHI	Berks	3 hr
Jul 28, 6:16 PM EDT	Tornado Warning	PHI	Chester	29 min
Jul 28, 6:17 PM EDT	Flash Flood Warning	PHI	Bucks, Lehigh, Northampton	6 hr
Jul 28, 6:23 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	67 min
Jul 28, 6:46 PM EDT	Tornado Warning	PHI	Delaware	29 min
Jul 28, 7:06 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	54 min
Jul 28, 7:08 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	35 min
Jul 28, 7:11 PM EDT	Flash Flood Warning	PHI	Delaware, Philadelphia	3 hr
Jul 28, 7:24 PM EDT	Flash Flood Warning	PHI	Chester	4 hr
Jul 28, 7:31 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Northampton	44 min
Jul 28, 7:55 PM EDT	Flash Flood Warning	PHI	Bucks, Montgomery	4 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2026 Every 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.