Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 72, NWS Philadelphia/Mount Holly

July 25, 2023Delaware County, Pennsylvania; New Castle County, Delaware; Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 25, 2023, 1:38 PM EDT for Delaware County, Pennsylvania; New Castle County, Delaware; Gloucester County, New Jersey. It was in force for 4 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: Jul 25, 2023, 1:38 PM EDT (17:38 UTC)
Expired: Jul 25, 2023, 5:45 PM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties New Castle County, DE, Gloucester County, NJ, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 89 km from the middle of the area, began a volume at 17:40 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
Jul 25, 1:47 PM EDT	FLASH FLOOD	Chester, PA	Trained Spotter relays report of street flooding on Route 201 with ongoing water rescues and people stuck in cars.

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 12:00Z, 5.6 hours before the alert went out and 193 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: 591 J/kg
Mixed-layer CIN: -87 J/kg
Mixed-layer LCL: 1068 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 52 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

826 
WGUS51 KPHI 251738
FFWPHI
DEC003-NJC015-PAC045-252145-
/O.NEW.KPHI.FF.W.0072.230725T1738Z-230725T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
138 PM EDT Tue Jul 25 2023

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northeastern New Castle County in northern Delaware...
  Northwestern Gloucester County in southern New Jersey...
  South Central Delaware County in southeastern Pennsylvania...

* Until 545 PM EDT.

* At 138 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 2 inches 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...
  Wilmington, Chester, Arden, Chester Township, Nether Providence 
  Township, Brookhaven, Upland, Eddystone, Marcus Hook, Parkside, 
  Trainer, and Bellefonte.

This includes the following highways...
	Interstate 95 in Pennsylvania between mile markers 0 and 6.
	Interstate 95 in Delaware between mile markers 18 and 23.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3982 7554 3989 7538 3985 7532 3983 7530
      3978 7541 3978 7542 3978 7543 3978 7544
      3977 7545 3977 7546 3976 7546 3974 7550

FLASH FLOOD...RADAR INDICATED

$$

RCM

2 follow-up statements

097 
WGUS71 KPHI 251803
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
203 PM EDT Tue Jul 25 2023

NJC015-251813-
/O.CAN.KPHI.FF.W.0072.000000T0000Z-230725T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gloucester NJ-
203 PM EDT Tue Jul 25 2023

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN GLOUCESTER 
COUNTY...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

LAT...LON 3982 7554 3989 7538 3985 7532 3985 7534
      3984 7535 3980 7542 3980 7541 3978 7544
      3977 7545 3977 7546 3976 7546 3974 7550

$$

DEC003-PAC045-252145-
/O.CON.KPHI.FF.W.0072.000000T0000Z-230725T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Delaware PA-
203 PM EDT Tue Jul 25 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM EDT THIS 
AFTERNOON FOR NORTHEASTERN NEW CASTLE AND SOUTH CENTRAL DELAWARE 
COUNTIES...

At 203 PM EDT, trained weather spotters reported thunderstorms 
producing heavy rain in Chester. Between 1 and 2.5 inches of rain 
have fallen. Additional rainfall amounts of 1 to 2 inches are 
possible in the warned area. Flash flooding is already occurring.

HAZARD...Life threatening flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets, and underpasses.

Some locations that may experience flash flooding include...
  Wilmington, Chester, Arden, Chester Township, Nether Providence 
  Township, Brookhaven, Upland, Eddystone, Marcus Hook, Parkside, 
  Trainer, and Bellefonte.

This includes the following highways...
	Interstate 95 in Pennsylvania between mile markers 0 and 6.
	Interstate 95 in Delaware between mile markers 18 and 23.

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.

&&

LAT...LON 3982 7554 3989 7538 3985 7532 3985 7534
      3984 7535 3980 7542 3980 7541 3978 7544
      3977 7545 3977 7546 3976 7546 3974 7550

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

RCM

514 
WGUS71 KPHI 252152
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
552 PM EDT Tue Jul 25 2023

DEC003-252202-
/O.EXP.KPHI.FF.W.0072.000000T0000Z-230725T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-
552 PM EDT Tue Jul 25 2023

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTHEASTERN NEW CASTLE AND 
SOUTH CENTRAL DELAWARE COUNTIES...

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

LAT...LON 3982 7554 3989 7538 3985 7532 3985 7534
      3980 7542 3980 7541 3977 7545 3977 7546
      3976 7546 3974 7550

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 11:58 AM EDT	Special Weather Statement	PHI	Montgomery	32 min
Jul 25, 12:07 PM EDT	Special Weather Statement	PHI	Berks	23 min
Jul 25, 12:16 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Montgomery	44 min
Jul 25, 12:31 PM EDT	Special Weather Statement	PHI	Berks	29 min
Jul 25, 12:33 PM EDT	Special Weather Statement	PHI	Berks	27 min
Jul 25, 12:37 PM EDT	Special Weather Statement	PHI	Carbon	38 min
Jul 25, 12:47 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery	33 min
Jul 25, 12:56 PM EDT	Special Weather Statement	PHI	Northampton	34 min
Jul 25, 1:00 PM EDT	Special Weather Statement	PHI	Berks	30 min
Jul 25, 1:03 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	42 min
Jul 25, 1:06 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe, Northampton	39 min
Jul 25, 1:10 PM EDT	Special Weather Statement	PHI	Delaware	35 min
Jul 25, 1:12 PM EDT	Special Weather Statement	PHI	Monroe	33 min
Jul 25, 1:20 PM EDT	Flash Flood Warning	PHI	Bucks, Montgomery	5 hr
Jul 25, 1:27 PM EDT	Areal Flood Advisory	PHI	Berks	3 hr
Jul 25, 1:27 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	48 min
Jul 25, 1:37 PM EDT	Areal Flood Advisory	PHI	Carbon	3 hr
Jul 25, 1:41 PM EDT	Areal Flood Advisory	PHI	Lehigh, Northampton	3 hr
Jul 25, 1:42 PM EDT	Special Weather Statement	PHI	Philadelphia	33 min
Jul 25, 1:49 PM EDT	Special Weather Statement	PHI	Chester	26 min
Jul 25, 1:54 PM EDT	Flash Flood Warning	PHI	Delaware, Philadelphia	4 hr
Jul 25, 1:55 PM EDT	Areal Flood Advisory	PHI	Monroe	2 hr
Jul 25, 2:06 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	39 min
Jul 25, 2:14 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Montgomery	46 min
Jul 25, 2:21 PM EDT	Areal Flood Advisory	PHI	Berks, Chester, Montgomery	2 hr
Jul 25, 2:36 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Montgomery, Philadelphia	39 min
Jul 25, 2:51 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	3 hr
Jul 25, 2:57 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Jul 25, 3:06 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Montgomery	95 min
Jul 25, 3:13 PM EDT	Flash Flood Warning	PHI	Chester	4 hr
Jul 25, 3:16 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	44 min
Jul 25, 3:21 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	39 min
Jul 25, 3:34 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	3 hr
Jul 25, 3:58 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	30 min
Jul 25, 4:04 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	3 hr
Jul 25, 4:55 PM EDT	Flash Flood Warning	PHI	Chester	118 min
Jul 25, 5:07 PM EDT	River Flood Warning	PHI	Chester	6 hr
Jul 25, 12:26 PM EDT	Special Weather Statement	PHI	Kent	34 min
Jul 25, 12:52 PM EDT	Special Weather Statement	PHI	New Castle	23 min
Jul 25, 1:34 PM EDT	Special Weather Statement	PHI	Kent	26 min
Jul 25, 2:51 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	39 min
Jul 25, 3:21 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	39 min
Jul 25, 4:01 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	44 min
Jul 25, 1:21 PM EDT	Special Weather Statement	PHI	Hunterdon	24 min
Jul 25, 1:52 PM EDT	Special Marine Warning	PHI		38 min
Jul 25, 2:08 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Somerset	52 min
Jul 25, 2:20 PM EDT	Severe Thunderstorm Warning	PHI	Cumberland	55 min
Jul 25, 2:39 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Morris, Somerset, Sussex	51 min
Jul 25, 2:44 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	2 hr
Jul 25, 2:45 PM EDT	Special Marine Warning	PHI		60 min
Jul 25, 2:53 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth, Somerset	52 min
Jul 25, 3:24 PM EDT	Special Marine Warning	PHI		96 min
Jul 25, 3:27 PM EDT	Areal Flood Advisory	PHI	Middlesex, Somerset	81 min
Jul 25, 3:40 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth, Ocean	50 min
Jul 25, 3:45 PM EDT	Special Marine Warning	PHI		60 min
Jul 25, 3:52 PM EDT	Severe Thunderstorm Warning	PHI	Cape May, Cumberland	53 min
Jul 25, 3:57 PM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth	3 hr
Jul 25, 4:12 PM EDT	Flash Flood Warning	PHI	Monmouth	3 hr
Jul 25, 4:17 PM EDT	Special Marine Warning	PHI		58 min
Jul 25, 4:50 PM EDT	Special Marine Warning	PHI		55 min
Jul 25, 4:57 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	2 hr
Jul 25, 5:09 PM EDT	Special Marine Warning	PHI		66 min

Nearby

Flash Flood Warnings in Pennsylvania, 2023 Flash Flood Warnings in Delaware, 2023 Flash Flood Warnings in New Jersey, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.