Alert archive / Pennsylvania / Flash Flood Warnings in 2022

Flash Flood Warning 7, NWS Philadelphia/Mount Holly

July 28, 2022Bucks County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 28, 2022, 9:20 PM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 92 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
Jul 28, 2022, 9:20 PM EDT (01:20 UTC)
Expired
Jul 28, 2022, 10:52 PM EDT
In force
92 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Bucks County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 57 km from the middle of the area, began a volume at 01:19 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.3 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 00:00Z on 2022-07-29Temperature 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, Washington/Dulle, VA at 00:00Z on 2022-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 square meters per square second.19395878Sfc1 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
0 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted.

455 
WGUS51 KPHI 290120
FFWPHI
PAC017-091-101-290530-
/O.NEW.KPHI.FF.W.0007.220729T0120Z-220729T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
920 PM EDT Thu Jul 28 2022

The National Weather Service in Mount Holly has issued a

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

* Until 130 AM EDT.

* At 920 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 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...
  Philadelphia, Bensalem, Burlington, Bristol, Conshohocken, 
  Palmyra, Beverly, Wissinoming, Tacony, Holmesburg, Germantown, and 
  Andalusia.

This includes the following highways...
	Interstate 95 in Pennsylvania between mile markers 27 and 39.
	Interstate 76 in Pennsylvania between mile markers 333 and 338.

This includes the following streams and drainages...
  Crosswicks-Neshaminy, Schuylkill, and Lower Delaware.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4003 7533 4008 7530 4008 7523 4006 7507
      4009 7500 4013 7490 4010 7484 4008 7486
      4006 7494 4005 7498 4002 7501 4000 7508

FLASH FLOOD...RADAR INDICATED

$$

RCM
1 follow-up statement
132 
WGUS71 KPHI 290252
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1052 PM EDT Thu Jul 28 2022

PAC017-091-101-290302-
/O.CAN.KPHI.FF.W.0007.000000T0000Z-220729T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-Philadelphia PA-
1052 PM EDT Thu Jul 28 2022

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN BUCKS, SOUTHEASTERN 
MONTGOMERY, AND CENTRAL PHILADELPHIA COUNTIES...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat.

LAT...LON 4003 7533 4008 7530 4008 7523 4006 7507
      4013 7490 4010 7484 4008 7486 4007 7493
      4005 7498 4002 7501 4000 7508

$$

RCM

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 8:07 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia53 min
Jul 28, 8:44 PM EDTAreal Flood AdvisoryPHIBucks, Delaware, Montgomery, Philadelphia2 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2022Every flash flood warning in 2022

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.