Alert archive / Pennsylvania / Flash Flood Warnings in 2025

Flash Flood Warning 48, NWS Philadelphia/Mount Holly

July 9, 2025New Castle County, Delaware; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 9, 2025, 8:00 PM EDT for New Castle County, Delaware; 4 counties in Pennsylvania. It was in force for 4 hr. 22 reports 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 9, 2025, 8:00 PM EDT (00:00 UTC)
Expired: Jul 10, 2025, 12:00 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties New Castle County, DE, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 81 km from the middle of the area, began a volume at 00:03 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 9, 8:00 PM EDT	FLASH FLOOD	Concord Twp, PA	Road flooding with car stranded at Spring Valley Rd and Brinton Lake Rd.
Jul 9, 8:00 PM EDT	FLASH FLOOD	Elam, PA	US 202 flooded in Elam.
Jul 9, 8:00 PM EDT	FLASH FLOOD	Fairfax, DE	Roadway flooding ongoing in Fairfax. Several roads underwater. Time given in report.
Jul 9, 8:05 PM EDT	FLASH FLOOD	Glen Mills, PA	Roadway flooded and vehicles stranded at Baltimore Pike and Brinton Lake Rd.
Jul 9, 8:10 PM EDT	FLASH FLOOD	1 N Wooddale, DE	Creek Rd. at Snuff Mill Rd. closed due to flooding.
Jul 9, 8:24 PM EDT	FLASH FLOOD	Wilmington, DE	Buildings and street flooding in Wilmington. People stranded.
Jul 9, 8:34 PM EDT	FLASH FLOOD	1 Wsw Bridesburg, PA	Flooding on I-95 southbound between Exit 30: COTTMAN AVE/RHAWN ST and Exit 26: BETSY ROSS BR/ARAMINGO AVE. There is a lane restriction.
Jul 9, 8:38 PM EDT	FLASH FLOOD	Glen Mills, PA	Several public reports of water rescues ongoing in Glens Mills.
Jul 9, 8:45 PM EDT	FLASH FLOOD	2 Ese London Britain Tw, PA	The White Clay Creek at Strickersville rapidly went into flood stage.
Jul 9, 8:52 PM EDT	FLASH FLOOD	Lansdowne, PA	Road flooding at Union Ave and Bartram Ave with a vehicle stranded.
Jul 9, 8:53 PM EDT	FLASH FLOOD	Chester, PA	Road flooding at W 2nd St. and Central Ave. Vehicle stranded.
Jul 9, 8:57 PM EDT	FLASH FLOOD	1 Wnw Tinicum Twp, PA	Flooding on I-95 southbound between Exit 9B/9A: PA 420 - PROSPECT PARK / ESSINGTON and Exit 8: RIDLEY PARK. There is a lane restriction.
Jul 9, 8:58 PM EDT	FLASH FLOOD	1 Ssw Summerdale, PA	The Frankford Creek went rapidly into flood stage.
Jul 9, 8:58 PM EDT	FLASH FLOOD	1 W Tinicum Twp, PA	Flooding on I-95 southbound between Exit 9B/9A: PA 420 - PROSPECT PARK / ESSINGTON and Exit 8: RIDLEY PARK. There is a lane restriction.
Jul 9, 9:00 PM EDT	FLASH FLOOD	1 Nw New Castle County, DE	Flooding reported on Airport Rd near the Christiana River.
Jul 9, 9:00 PM EDT	FLASH FLOOD	Hockessin, DE	Hockessin Park is underwater from Mill Creek as shown in video and pictures sent in.
Jul 9, 9:25 PM EDT	FLASH FLOOD	1 Sw Shawmont - Philade, PA	Flooding on I-76 eastbound between 1 miles WEST of Exit 338: GREEN LANE/BELMONT AVE and Exit 338: GREEN LANE/BELMONT AVE. There is a lane restriction.
Jul 9, 9:25 PM EDT	FLASH FLOOD	1 W Manayunk, PA	Flooding on I-76 eastbound between 1 miles WEST of Exit 338: GREEN LANE/BELMONT AVE and Exit 338: GREEN LANE/BELMONT AVE. There is a lane restriction.
Jul 9, 9:28 PM EDT	FLASH FLOOD	Trainer, PA	Flooded roadway with vehicle stranded at Post Rd. and Price St.
Jul 9, 9:30 PM EDT	FLASH FLOOD	Tybrook, DE	The Red Clay Creek at Woodale rose rapidly into flood stage.
Jul 9, 10:30 PM EDT	FLASH FLOOD	2 Ese London Britain Tw, PA	The White Clay Creek at Strickersville went into Major Flood stage.
Jul 9, 10:44 PM EDT	FLASH FLOOD	Ridley Park, PA	Live news broadcast showed video of water covering roadways in the Ridley Park area.

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, 0.0 hours before the alert went out and 205 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: 281 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 860 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: -38 m²/s²
0-3 km storm-relative helicity: -12 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.4

Open this sounding in Storm Lab

The text

As transmitted.

350 
WGUS51 KPHI 100000
FFWPHI
DEC003-PAC029-045-091-101-100400-
/O.NEW.KPHI.FF.W.0048.250710T0000Z-250710T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
800 PM EDT Wed Jul 9 2025

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northern New Castle County in northern Delaware...
  Southeastern Chester County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...

* Until midnight EDT tonight.

* At 800 PM EDT, trained weather spotters reported thunderstorms 
  producing heavy rain with numerous roads flooded in southeast PA. 
  Between 1.5 and 3 inches of rain have fallen. The expected 
  rainfall rate is 1.5 to 3 inches in 1 hour. 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...
  Philadelphia, Camden, Wilmington, Newark, Chester, Pennsville, 
  Yeadon, Carneys Point, Conshohocken, Palmyra, Folcroft and 
  Swarthmore.

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 3983 7566 3986 7559 3993 7553 4006 7557
      4009 7554 4011 7520 4015 7507 4012 7496
      4010 7496 4006 7498 4005 7497 3996 7513
      3991 7513 3988 7515 3984 7535 3977 7546
      3972 7548 3961 7560 3961 7579 3972 7580

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR

$$

Staarmann

1 follow-up statement

855 
WGUS71 KPHI 100351
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1151 PM EDT Wed Jul 9 2025

DEC003-PAC029-045-091-101-100401-
/O.EXP.KPHI.FF.W.0048.000000T0000Z-250710T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Chester PA-Delaware PA-Montgomery PA-Philadelphia
PA-
1151 PM EDT Wed Jul 9 2025

...FLASH FLOOD WARNING WILL EXPIRE AT MIDNIGHT EDT TONIGHT FOR 
NORTHERN NEW CASTLE, SOUTHEASTERN CHESTER, DELAWARE, SOUTHEASTERN 
MONTGOMERY AND PHILADELPHIA COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
widespread threat. With some rivers above flood stage and standing 
water reported on some roadways, more targeted Flood Warnings were 
issued for portions of New Castle County, DE and Delaware County, 
PA. Please refer to those bulletins for updated information. Please 
continue to heed remaining road closures.

&&

LAT...LON 3983 7566 3986 7559 3993 7553 4006 7557
      4009 7554 4011 7520 4015 7507 4012 7496
      4010 7496 4006 7498 4005 7497 3996 7513
      3991 7513 3988 7515 3984 7535 3977 7546
      3972 7548 3961 7560 3961 7579 3972 7580

$$

Hoeflich

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 8:32 PM EDT	Flash Flood Warning Considerable damage threat	PHI	New Castle	4 hr
Jul 9, 8:46 PM EDT	Tornado Warning	PHI	New Castle	29 min
Jul 9, 8:51 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	39 min
Jul 9, 9:13 PM EDT	Tornado Warning	PHI	Sussex	32 min
Jul 9, 9:30 PM EDT	River Flood Warning	PHI	New Castle	7 hr
Jul 9, 11:27 PM EDT	River Flood Warning	PHI	New Castle	8 hr
Jul 9, 11:44 PM EDT	Areal Flood Warning	PHI	New Castle	4 hr
Jul 10, 4:15 PM EDT	Flash Flood Warning	PHI	Kent	117 min
Jul 10, 7:33 PM EDT	Flash Flood Warning	PHI	Sussex	104 min
Jul 9, 8:47 PM EDT	Flash Flood Warning	PHI	Bucks, Philadelphia	2 hr
Jul 9, 9:57 PM EDT	River Flood Warning	PHI	Delaware	7 hr
Jul 9, 10:35 PM EDT	Areal Flood Warning	PHI	Chester	4 hr
Jul 9, 10:46 PM EDT	River Flood Warning	PHI	Chester, Delaware	8 hr
Jul 9, 11:48 PM EDT	Areal Flood Warning	PHI	Delaware	4 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2025 Flash Flood Warnings in Delaware, 2025 Every flash flood warning in 2025

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.