Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 89, NWS Philadelphia/Mount Holly

October 5, 2021Camden County, Gloucester County, New Jersey; Delaware County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Oct 5, 2021, 2:27 AM EDT for Camden County, Gloucester County, New Jersey; Delaware County, Philadelphia County, Pennsylvania. It was in force for 3 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: Oct 5, 2021, 2:27 AM EDT (06:27 UTC)
Expired: Oct 5, 2021, 5:30 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Camden County, NJ, Gloucester County, NJ, Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 68 km from the middle of the area, began a volume at 06:31 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.

What was reported inside it

Time	Report	Where	Remark
Oct 5, 2:40 AM EDT	FLOOD	1 Se South Philadelphia, PA	REPORT OF MINOR FLOODING ALONG INTERSTATE 76 IN PHILADELPHIA.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 6.5 hours before the alert went out and 216 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: 1291 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1228 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 49 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

550 
WGUS51 KPHI 050627
FFWPHI
NJC007-015-PAC045-101-050930-
/O.NEW.KPHI.FF.W.0089.211005T0627Z-211005T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
227 AM EDT Tue Oct 5 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern Camden County in southern New Jersey...
  North Central Gloucester County in southern New Jersey...
  Southeastern Delaware County in southeastern Pennsylvania...
  Southwestern Philadelphia County in southeastern Pennsylvania...

* Until 530 AM EDT.

* At 227 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 2.5 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...
  Philadelphia, Camden, Gloucester City, West Deptford, Bellmawr, 
  Yeadon, Woodbury, Folcroft, Paulsboro, Westville, National Park, 
  and Brooklawn.

This includes the following highways...
	Interstate 95 in Pennsylvania between mile markers 10 and 25.
	Interstate 76 in Pennsylvania between mile markers 344 and 351.
	Interstate 76 in New Jersey between mile markers 1 and 3.
	Interstate 295 in New Jersey between mile markers 20 and 25.
	Interstate 676 in Pennsylvania between mile markers 0 and 1.
	Interstate 676 in New Jersey between mile markers 0 and 4.

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.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3989 7529 3994 7525 3995 7524 3999 7509
      3995 7504 3987 7512 3982 7519 3983 7531

FLASH FLOOD...RADAR INDICATED

$$

PO

2 follow-up statements

172 
WGUS71 KPHI 050811
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
411 AM EDT Tue Oct 5 2021

NJC007-015-PAC045-101-050930-
/O.CON.KPHI.FF.W.0089.000000T0000Z-211005T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Camden NJ-Gloucester NJ-Delaware PA-Philadelphia PA-
411 AM EDT Tue Oct 5 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 AM EDT EARLY THIS 
MORNING FOR NORTHWESTERN CAMDEN, NORTH CENTRAL GLOUCESTER, 
SOUTHEASTERN DELAWARE, AND SOUTHWESTERN PHILADELPHIA COUNTIES...

At 411 AM EDT, Doppler radar indicated that the first area of 
thunderstorms has moved away, but another area is approaching. 
Additional rainfall up to an inch is possible through 500 AM.

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, West Deptford, Bellmawr, 
  Yeadon, Woodbury, Folcroft, Paulsboro, Westville, National Park, 
  and Brooklawn.

This includes the following highways...
	Interstate 95 in Pennsylvania between mile markers 10 and 25.
	Interstate 76 in Pennsylvania between mile markers 344 and 351.
	Interstate 76 in New Jersey between mile markers 1 and 3.
	Interstate 295 in New Jersey between mile markers 19 and 24.
	Interstate 676 in Pennsylvania between mile markers 0 and 1.
	Interstate 676 in New Jersey between mile markers 0 and 4.

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 3989 7529 3994 7525 3995 7524 3999 7509
      3995 7504 3987 7512 3982 7519 3983 7531

FLASH FLOOD...RADAR INDICATED

$$

PO

512 
WGUS71 KPHI 050922
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
522 AM EDT Tue Oct 5 2021

NJC007-015-PAC045-101-050932-
/O.EXP.KPHI.FF.W.0089.000000T0000Z-211005T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Camden NJ-Gloucester NJ-Delaware PA-Philadelphia PA-
522 AM EDT Tue Oct 5 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 530 AM EDT EARLY THIS MORNING 
FOR NORTHWESTERN CAMDEN, NORTH CENTRAL GLOUCESTER, SOUTHEASTERN 
DELAWARE, AND SOUTHWESTERN PHILADELPHIA COUNTIES...

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

LAT...LON 3989 7529 3994 7525 3995 7524 3999 7509
      3995 7504 3987 7512 3982 7519 3983 7531

$$

PO

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 5, 12:49 AM EDT	Special Weather Statement	PHI	Salem	26 min
Oct 5, 2:10 AM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Salem	4 hr
Oct 5, 2:51 AM EDT	Special Weather Statement	PHI	Atlantic	39 min
Oct 5, 3:20 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Ocean	3 hr
Oct 5, 3:33 AM EDT	Special Weather Statement	PHI	Atlantic	57 min
Oct 5, 12:32 AM EDT	Special Weather Statement	PHI	Chester	43 min
Oct 5, 1:24 AM EDT	Special Weather Statement	PHI	Montgomery	36 min

Nearby

Flash Flood Warnings in New Jersey, 2021 Flash Flood Warnings in Pennsylvania, 2021 Every flash flood warning in 2021

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.