Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 67, NWS Philadelphia/Mount Holly

July 27, 2026Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 27, 2026, 5:25 PM EDT for Lehigh County, Pennsylvania. It was in force for 2 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
Jul 27, 2026, 5:25 PM EDT (21:25 UTC)
Expired
Jul 27, 2026, 7:28 PM EDT
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 125 km from the middle of the area, began a volume at 21:25 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 12:00Z, 9.4 hours before the alert went out and 235 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 2026-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 87 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 2026-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
87 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
1233 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

181 
WGUS51 KPHI 272125
FFWPHI
PAC077-280130-
/O.NEW.KPHI.FF.W.0067.260727T2125Z-260728T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
525 PM EDT Mon Jul 27 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Central Lehigh County in eastern Pennsylvania...

* Until 930 PM EDT.

* At 525 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. 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...
  Claussville and Ancient Oaks.

This includes the following highways...
	Northeast Extension between mile markers 57 and 58.
	Interstate 78 in Pennsylvania between mile markers 45 and 54.

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.

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 4058 7574 4062 7567 4062 7561
      4060 7555

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

$$

MJL
1 follow-up statement
147 
WGUS71 KPHI 272328 RRA
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
728 PM EDT Mon Jul 27 2026

PAC077-272338-
/O.CAN.KPHI.FF.W.0067.000000T0000Z-260728T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lehigh PA-
728 PM EDT Mon Jul 27 2026

...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL LEHIGH COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

&&

LAT...LON 4051 7563 4058 7574 4062 7567 4062 7561
      4060 7555

$$

MJL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 2:15 PM EDTFlood WatchPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more38 hr
Jul 27, 2:57 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia48 min
Jul 27, 3:01 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery44 min
Jul 27, 3:41 PM EDTSevere Thunderstorm WarningPHIMontgomery, Philadelphia49 min
Jul 27, 3:50 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton40 min
Jul 27, 3:58 PM EDTFlash Flood WarningPHIDelaware, Montgomery, Philadelphia3 hr
Jul 27, 5:51 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh23 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.