Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 28, NWS Philadelphia/Mount Holly

July 5, 2023Delaware County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 5, 2023, 5:45 PM EDT for Delaware County, Philadelphia County, Pennsylvania. It was in force for 107 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 5, 2023, 5:45 PM EDT (21:45 UTC)
Expired: Jul 5, 2023, 7:32 PM EDT
In force: 107 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 68 km from the middle of the area, began a volume at 21:46 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, 9.8 hours before the alert went out and 217 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: 275 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 1031 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -1 m²/s²
0-3 km storm-relative helicity: 26 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

074 
WGUS51 KPHI 052145
FFWPHI
PAC045-101-060115-
/O.NEW.KPHI.FF.W.0028.230705T2145Z-230706T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
545 PM EDT Wed Jul 5 2023

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  East Central Delaware County in southeastern Pennsylvania...
  Southwestern Philadelphia County in southeastern Pennsylvania...

* Until 915 PM EDT.

* At 545 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. Additional rainfall amounts of 0.5 to 1 inch 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...
  Philadelphia, Camden, Gloucester City, Yeadon, Paulsboro, National 
  Park, East Lansdowne, South Philadelphia, Philadelphia 
  International Airport, Darby Township, Tinicum Township, and Darby.

This includes the following highways...
	Interstate 95 in Pennsylvania between mile markers 11 and 21.
	Interstate 76 in Pennsylvania between mile markers 344 and 351.
	Interstate 676 in Pennsylvania between mile markers 0 and 1.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3999 7524 3996 7514 3990 7513 3988 7518
      3988 7519 3988 7520 3987 7520 3985 7526
      3997 7527

FLASH FLOOD...RADAR INDICATED

$$

Fitzsimmons

1 follow-up statement

861 
WGUS71 KPHI 052332
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
732 PM EDT Wed Jul 5 2023

PAC045-101-052342-
/O.CAN.KPHI.FF.W.0028.000000T0000Z-230706T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Delaware PA-Philadelphia PA-
732 PM EDT Wed Jul 5 2023

...FLASH FLOOD WARNING IS CANCELLED FOR EAST CENTRAL DELAWARE AND 
SOUTHWESTERN PHILADELPHIA COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat.

LAT...LON 3999 7524 3996 7514 3990 7513 3988 7518
      3988 7519 3988 7520 3987 7520 3985 7526
      3997 7527

$$

Brudy

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 5:22 PM EDT	Areal Flood Advisory	PHI	Delaware, Philadelphia	3 hr
Jul 5, 5:26 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	34 min
Jul 5, 5:57 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	33 min
Jul 5, 6:30 PM EDT	Severe Thunderstorm Warning	PHI	Delaware	30 min

Nearby

Flash Flood Warnings in Pennsylvania, 2023 Every 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.