Alert archive / Delaware / Flash Flood Warnings in 2025
Flash Flood Warning 46, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 9, 2025, 7:38 PM EDT for New Castle County, Delaware; Delaware County, Pennsylvania. It was in force for 4 hr. 7 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, 7:38 PM EDT (23:38 UTC)
- Expired
- Jul 9, 2025, 11:45 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties New Castle County, DE, Delaware County, PA
The radar
The Philadelphia radar (KDIX), 94 km from the middle of the area, began a volume at 23:42 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, 8:52 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 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, 9:28 PM EDT | FLASH FLOOD | Trainer, PA | Flooded roadway with vehicle stranded at Post Rd. and Price St. |
| 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 12:00Z, 11.6 hours before the alert went out and 189 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.
- Mixed-layer CAPE
- 647 J/kg
- Mixed-layer CIN
- -65 J/kg
- Mixed-layer LCL
- 836 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- -8 m²/s²
- 0-3 km storm-relative helicity
- 42 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.0
The text
As transmitted.
476
WGUS51 KPHI 092338
FFWPHI
DEC003-PAC045-100345-
/O.NEW.KPHI.FF.W.0046.250709T2338Z-250710T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
738 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 Delaware County in southeastern Pennsylvania...
* Until 1145 PM EDT.
* At 738 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1 inch of rain
has 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 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, Newark, Chester, Yeadon, Folcroft, Swarthmore, New
Castle, East Lansdowne, Newport, Wilmington Manor and Chester
Township.
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 3961 7579 3968 7579 3969 7565 3973 7556
3986 7538 3992 7535 3996 7536 3995 7525
3994 7524 3988 7526 3985 7531 3985 7534
3978 7546 3971 7550 3964 7557 3960 7568
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR
$$
HoeflichThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 8, 9:52 PM EDT | Flood Watch | PHI | Kent, New Castle, Sussex | 26 hr |
| Jul 9, 7:18 PM EDT | Flash Flood Warning | PHI | New Castle | 4 hr |
| Jul 9, 7:24 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 51 min |
| Jul 9, 6:39 PM EDT | Flash Flood Warning | PHI | Chester | 4 hr |
| Jul 9, 7:47 PM EDT | Flash Flood Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 4 hr |
Nearby
Flash Flood Warnings in Delaware, 2025Flash Flood Warnings in Pennsylvania, 2025Every 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.