Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2025
Severe Thunderstorm Warning 173, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 2025, 7:24 PM EDT for New Castle County, Delaware; Chester County, Delaware County, Pennsylvania. It was in force for 51 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jul 9, 2025, 7:24 PM EDT (23:24 UTC)
- Expired
- Jul 9, 2025, 8:15 PM EDT
- In force
- 51 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties New Castle County, DE, Chester County, PA, Delaware County, PA
The radar
The Philadelphia radar (KDIX), 108 km from the middle of the area, began a volume at 23:26 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 9, 5:31 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 11.4 hours before the alert went out and 177 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.
988
WUUS51 KPHI 092324
SVRPHI
DEC003-PAC029-045-100015-
/O.NEW.KPHI.SV.W.0173.250709T2324Z-250710T0015Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
724 PM EDT Wed Jul 9 2025
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Northern New Castle County in northern Delaware...
Southeastern Chester County in southeastern Pennsylvania...
Southwestern Delaware County in southeastern Pennsylvania...
* Until 815 PM EDT.
* At 724 PM EDT, a severe thunderstorm was located over Landenberg,
or 8 miles north of Newark, moving northeast at 15 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
* Locations impacted include...
Wilmington, West Chester, Westtown, Elsmere, Kennett Square, West
Grove, Arden, Cheyney, North Star, Talleyville, Elam, Pike Creek,
Ashland, Greenville, Landenberg, Concordville, Kemblesville,
Hockessin, West Goshen, and Avondale.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4000 7554 3978 7544 3975 7547 3971 7579
3972 7579 3972 7585 3983 7589
TIME...MOT...LOC 2324Z 236DEG 13KT 3980 7579
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Staarmann2 follow-up statements
764
WWUS51 KPHI 092342
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
742 PM EDT Wed Jul 9 2025
DEC003-PAC029-045-100015-
/O.CON.KPHI.SV.W.0173.000000T0000Z-250710T0015Z/
New Castle DE-Chester PA-Delaware PA-
742 PM EDT Wed Jul 9 2025
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM EDT
FOR NORTHERN NEW CASTLE...SOUTHEASTERN CHESTER AND SOUTHWESTERN
DELAWARE COUNTIES...
At 742 PM EDT, a severe thunderstorm was located over Hockessin, or 9
miles north of Newark, moving northeast at 15 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Wilmington, West Chester, Westtown, Elsmere, Kennett Square, Arden,
Greenville, Cheyney, North Star, Talleyville, Landenberg, Elam, Pike
Creek, Concordville, Hockessin, Ashland, West Goshen, Avondale,
Bellefonte, and Ardentown.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Frequent cloud to ground lightning is occurring with this storm. Move
indoors immediately. Lightning is one of nature's leading killers.
Remember, if you can hear thunder, you are close enough to be struck
by lightning.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4000 7554 3978 7544 3975 7547 3971 7579
3972 7579 3982 7581
TIME...MOT...LOC 2342Z 242DEG 13KT 3981 7571
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Staarmann664
WWUS51 KPHI 100006
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
806 PM EDT Wed Jul 9 2025
DEC003-PAC029-045-100015-
/O.EXP.KPHI.SV.W.0173.000000T0000Z-250710T0015Z/
New Castle DE-Chester PA-Delaware PA-
806 PM EDT Wed Jul 9 2025
...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN NEW CASTLE...
SOUTHEASTERN CHESTER AND SOUTHWESTERN DELAWARE COUNTIES WILL EXPIRE
AT 815 PM EDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However heavy
rain is still possible with this thunderstorm. A Flash Flood Warning
remains in effect for this entire area.
A Severe Thunderstorm Watch remains in effect until midnight EDT for
northern Delaware...southern New Jersey...and southeastern
Pennsylvania.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.
LAT...LON 4000 7554 3978 7544 3975 7547 3971 7579
3972 7579 3982 7581
TIME...MOT...LOC 0005Z 236DEG 13KT 3985 7563
$$
StaarmannThe 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, 7:38 PM EDT | Flash Flood Warning | PHI | New Castle | 4 hr |
| 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
Severe Thunderstorm Warnings in Pennsylvania, 2025Severe Thunderstorm Warnings in Delaware, 2025Every severe thunderstorm 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.