Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 360, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 2, 2026, 12:40 PM EDT for Chester County, Pennsylvania. It was in force for 65 min. 3 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
- Sep 2, 2026, 12:40 PM EDT (16:40 UTC)
- Expired
- Sep 2, 2026, 1:45 PM EDT
- In force
- 65 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
County Chester County, PA
The radar
The Dover AFB radar (KDOX), 119 km from the middle of the area, began a volume at 16:42 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 |
|---|---|---|---|
| Sep 2, 1:19 PM EDT | TSTM WND DMG | 2 Sw Londonderry Twp, PA | Tree down on wires. Time estimated by radar. |
| Sep 2, 1:22 PM EDT | TSTM WND DMG | 2 Sw Londonderry Twp, PA | Tree and wires down. Time estimated by radar. |
| Sep 2, 1:28 PM EDT | TSTM WND DMG | 1 Se Franklin Twp., PA | Tree on wires. Time estimated by radar. |
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, 4.7 hours before the alert went out and 154 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
- 394 J/kg
- Mixed-layer CIN
- -133 J/kg
- Mixed-layer LCL
- 1089 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 49 m²/s²
- 0-3 km storm-relative helicity
- 35 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.0
The text
As transmitted.
764
WUUS51 KPHI 021640
SVRPHI
PAC029-021745-
/O.NEW.KPHI.SV.W.0360.260902T1640Z-260902T1745Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1240 PM EDT Wed Sep 2 2026
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Southwestern Chester County in southeastern Pennsylvania...
* Until 145 PM EDT.
* At 1240 PM EDT, severe thunderstorms were located along a line
extending from near Strasburg to near Delta to near Cockeysville,
moving southeast at 40 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
* Locations impacted include...
Oxford, Parkesburg, West Grove, Homeville, Glen Roy, Cochranville,
Landenberg, Mount Vernon, Kemblesville, North Star, Atglen,
Avondale, and Toughkenamon.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Mount Holly NJ.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3974 7612 3973 7610 3974 7610 3976 7606
3981 7603 3983 7604 3987 7599 3994 7598
3995 7600 4000 7596 3981 7570 3977 7575
3972 7577 3972 7613
TIME...MOT...LOC 1640Z 319DEG 35KT 3996 7622 3976 7634 3952 7666
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
MJL2 follow-up statements
055
WWUS51 KPHI 021716
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
116 PM EDT Wed Sep 2 2026
PAC029-021745-
/O.CON.KPHI.SV.W.0360.000000T0000Z-260902T1745Z/
Chester PA-
116 PM EDT Wed Sep 2 2026
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM EDT
FOR SOUTHWESTERN CHESTER COUNTY...
At 115 PM EDT, severe thunderstorms were located along a line
extending from Lombard to near Havre De Grace to near Bowleys
Quarters, moving east at 40 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Oxford, Parkesburg, West Grove, Homeville, Glen Roy, Cochranville,
Landenberg, Mount Vernon, Kemblesville, North Star, Atglen, Avondale,
and Toughkenamon.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Mount Holly NJ.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3974 7612 3973 7610 3974 7610 3976 7606
3981 7603 3983 7604 3987 7599 3994 7598
3995 7600 4000 7596 3981 7570 3977 7575
3972 7577 3972 7613
TIME...MOT...LOC 1715Z 270DEG 35KT 3971 7594 3951 7606 3927 7638
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
MJL598
WWUS51 KPHI 021736
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
136 PM EDT Wed Sep 2 2026
PAC029-021746-
/O.EXP.KPHI.SV.W.0360.000000T0000Z-260902T1745Z/
Chester PA-
136 PM EDT Wed Sep 2 2026
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CHESTER COUNTY
WILL EXPIRE AT 145 PM EDT...
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire. However heavy rain is still possible with
these thunderstorms.
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 3974 7612 3973 7610 3974 7610 3976 7606
3981 7603 3983 7604 3987 7599 3994 7598
3995 7600 4000 7596 3981 7570 3977 7575
3972 7577 3972 7613
TIME...MOT...LOC 1736Z 270DEG 35KT 3957 7578 3937 7590 3913 7622
$$
MJLThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 8:17 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 58 min |
| Sep 1, 8:44 PM EDT | Flash Flood Warning | PHI | Chester, Delaware | 3 hr |
| Sep 1, 9:19 PM EDT | Flash Flood Warning | PHI | Bucks | 116 min |
| Sep 2, 3:53 AM EDT | Heat Advisory | PHI | Berks, Bucks, Chester, Delaware, Montgomery, Philadelphia | 40 hr |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2026Every severe thunderstorm warning in 2026
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.