Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 12, NWS Philadelphia/Mount Holly

June 26, 2023Berks County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 26, 2023, 2:32 PM EDT for Berks County, Lehigh County, Pennsylvania. It was in force for 67 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 26, 2023, 2:32 PM EDT (18:32 UTC)
Expired
Jun 26, 2023, 3:39 PM EDT
In force
67 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Berks County, PA, Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 149 km from the middle of the area, began a volume at 18:31 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, 6.5 hours before the alert went out and 222 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 2023-06-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 543 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2023-06-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 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
543 J/kg
Mixed-layer CIN
-138 J/kg
Mixed-layer LCL
1005 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
58 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

384 
WGUS51 KPHI 261832
FFWPHI
PAC011-077-262130-
/O.NEW.KPHI.FF.W.0012.230626T1832Z-230626T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
232 PM EDT Mon Jun 26 2023

The National Weather Service in Mount Holly has issued a

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

* Until 530 PM EDT.

* At 232 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across 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...
  Hamburg, Lenhartsville, and Wanamakers.

This includes the following highways...
	Interstate 78 in Pennsylvania between mile markers 29 and 38.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4069 7586 4070 7583 4069 7582 4064 7577
      4060 7581 4052 7595 4051 7600 4054 7604
      4057 7608 4058 7607 4057 7605 4058 7604
      4057 7602 4064 7599

FLASH FLOOD...RADAR INDICATED

$$

PO
1 follow-up statement
150 
WGUS71 KPHI 261939
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
339 PM EDT Mon Jun 26 2023

PAC011-077-261949-
/O.CAN.KPHI.FF.W.0012.000000T0000Z-230626T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Lehigh PA-
339 PM EDT Mon Jun 26 2023

...FLASH FLOOD WARNING IS CANCELLED FOR NORTH CENTRAL BERKS AND 
WESTERN LEHIGH COUNTIES...

The heavy rains have ended. Flooding is no longer expected to pose a 
threat.

A Flood Watch remains in effect until 1200 AM EDT Tuesday for 
portions of New Jersey...and Pennsylvania.

LAT...LON 4069 7586 4070 7583 4069 7582 4064 7577
      4060 7581 4052 7595 4051 7600 4054 7604
      4057 7608 4058 7607 4057 7605 4058 7604
      4057 7602 4064 7599

$$

PO

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 26, 3:33 AM EDTFlood WatchPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more23 hr
Jun 26, 8:41 AM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton49 min
Jun 26, 9:18 AM EDTSevere Thunderstorm WarningPHICarbon, Monroe, Northampton42 min
Jun 26, 9:47 AM EDTSevere Thunderstorm WarningPHIMonroe, Northampton43 min
Jun 26, 1:13 PM EDTSevere Thunderstorm WarningPHIBerks47 min
Jun 26, 1:35 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh40 min
Jun 26, 2:04 PM EDTSevere Thunderstorm WarningPHIBerks41 min
Jun 26, 2:06 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton39 min
Jun 26, 2:12 PM EDTTornado WarningPHIBerks, Lehigh21 min
Jun 26, 2:21 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh54 min
Jun 26, 2:23 PM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh107 min
Jun 26, 2:31 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton44 min
Jun 26, 2:40 PM EDTSpecial Weather StatementPHIBucks35 min
Jun 26, 2:58 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton47 min
Jun 26, 3:02 PM EDTTornado WarningPHINorthampton28 min
Jun 26, 3:03 PM EDTAreal Flood AdvisoryPHIMonroe104 min
Jun 26, 3:25 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton41 min
Jun 26, 3:56 PM EDTAreal Flood AdvisoryPHIMonroe, Northampton2 hr
Jun 26, 4:04 PM EDTSpecial Weather StatementPHINorthampton41 min
Jun 26, 4:50 PM EDTAreal Flood AdvisoryPHILehigh, Northampton73 min
Jun 26, 5:47 PM EDTSpecial Weather StatementPHILebanon28 min
Jun 26, 5:59 PM EDTSevere Thunderstorm WarningPHIChester, Delaware24 min
Jun 26, 6:00 PM EDTAreal Flood AdvisoryPHIMonroe, Northampton4 hr
Jun 26, 6:03 PM EDTFlash Flood WarningPHILehigh, Northampton6 hr
Jun 26, 6:16 PM EDTSpecial Weather StatementPHIDelaware29 min
Jun 26, 6:26 PM EDTSpecial Weather StatementPHIChester34 min
Jun 26, 6:37 PM EDTFlash Flood WarningPHIChester, Delaware2 hr
Jun 26, 6:50 PM EDTSpecial Weather StatementPHIMontgomery25 min
Jun 26, 6:51 PM EDTSpecial Weather StatementPHINorthampton24 min
Jun 26, 7:13 PM EDTSpecial Weather StatementPHIBucks32 min
Jun 26, 7:26 PM EDTSpecial Weather StatementPHIMontgomery34 min
Jun 26, 7:44 PM EDTSpecial Weather StatementPHIDelaware, Montgomery31 min
Jun 26, 7:59 PM EDTSpecial Weather StatementPHILehigh31 min

Nearby

Flash Flood Warnings in Pennsylvania, 2023Every flash flood warning in 2023

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.