Alert archive / Delaware / Flash Flood Warnings in 2025
Flash Flood Warning 80, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 31, 2025, 2:09 PM EDT for New Castle County, Delaware; Delaware County, Pennsylvania. It was in force for 4 hr. 4 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 31, 2025, 2:09 PM EDT (18:09 UTC)
- Expired
- Jul 31, 2025, 6:15 PM 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, Delaware County, PA
The radar
The Philadelphia radar (KDIX), 95 km from the middle of the area, began a volume at 18:10 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 31, 2:41 PM EDT | FLASH FLOOD | Claymont, DE | Street flooding occurring along Philadelphia Pike in both directions at Alcott Avenue. |
| Jul 31, 2:41 PM EDT | RAIN 2.8 | Boothwyn, PA | 2.8 inches in under 1 hour. |
| Jul 31, 4:25 PM EDT | RAIN 4.05 | Boothwyn, PA | Updates previous rain report from Boothwyn. 4.05 inches in under 3 hour. |
| Jul 31, 4:56 PM EDT | FLASH FLOOD | Boothwyn, PA | Road flooded at the intersection of Larkin Road & Bethel Road. |
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, 6.2 hours before the alert went out and 190 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
- 1355 J/kg
- Mixed-layer CIN
- -40 J/kg
- Mixed-layer LCL
- 875 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 30 m²/s²
- 0-3 km storm-relative helicity
- 30 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
The text
As transmitted.
719
WGUS51 KPHI 311809
FFWPHI
DEC003-PAC045-312215-
/O.NEW.KPHI.FF.W.0080.250731T1809Z-250731T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
209 PM EDT Thu Jul 31 2025
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Northeastern New Castle County in northern Delaware...
Southwestern Delaware County in southeastern Pennsylvania...
* Until 615 PM EDT.
* At 209 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 1.5 inches of
rain have fallen. The expected rainfall rate is 1.5 to 3 inches in
1 hour. Additional rainfall amounts of 1 to 1.5 inches are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Life threatening flash flooding caused by
thunderstorms.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets, and underpasses.
* Some locations that may experience flash flooding include...
Chester, Swarthmore, Arden, Chelsea, Concordville, Lima, Chester
Township, Elam, Gradyville, Talleyville, Nether Providence
Township and Greenville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 3984 7560 3985 7560 3987 7559 3999 7543
3986 7531 3984 7536 3980 7541 3978 7552
3979 7562 3980 7561
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR
$$
Kruzdlo1 follow-up statement
637
WGUS71 KPHI 312208
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
608 PM EDT Thu Jul 31 2025
DEC003-PAC045-312218-
/O.EXP.KPHI.FF.W.0080.000000T0000Z-250731T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Delaware PA-
608 PM EDT Thu Jul 31 2025
...FLASH FLOOD WARNING WILL EXPIRE AT 615 PM EDT THIS EVENING FOR
NORTHEASTERN NEW CASTLE AND SOUTHWESTERN DELAWARE COUNTIES...
Although the heaviest rain has ended, continue to heed any road
closures that may be in effect due to earlier flooding.
A Flood Watch still remains in effect until 600 AM EDT Friday for
portions of northern Delaware, New Jersey, and southeast
Pennsylvania.
&&
LAT...LON 3984 7560 3985 7560 3987 7559 3999 7543
3986 7531 3984 7536 3980 7541 3978 7552
3979 7562 3980 7561
$$
KruzdloThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 3:56 AM EDT | Rip Current Statement | PHI | Sussex | 4 days |
| Jul 31, 2:05 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 40 min |
| Jul 31, 2:46 PM EDT | Flash Flood Warning | PHI | New Castle | 4 hr |
| Jul 31, 2:55 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 50 min |
| Jul 31, 4:32 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 21 min |
| Jul 31, 12:11 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Lehigh, Montgomery | 64 min |
| Jul 31, 12:19 PM EDT | Flash Flood Warning | PHI | Berks | 4 hr |
| Jul 31, 12:53 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery | 67 min |
| Jul 31, 1:27 PM EDT | Flash Flood Warning | PHI | Berks, Chester, Montgomery | 4 hr |
| Jul 31, 1:55 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 18 min |
| Jul 31, 2:03 PM EDT | Flash Flood Warning | PHI | Berks, Bucks, Lehigh, Montgomery | 2 hr |
| Jul 31, 2:27 PM EDT | Flash Flood Warning | PHI | Bucks, 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.