Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2025
Severe Thunderstorm Warning 202, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 31, 2025, 12:53 PM EDT for Chester County, Delaware County, Montgomery County, Pennsylvania. It was in force for 67 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 31, 2025, 12:53 PM EDT (16:53 UTC)
- Expired
- Jul 31, 2025, 2:00 PM EDT
- In force
- 67 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Chester County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 109 km from the middle of the area, began a volume at 16:54 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 nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 4.9 hours before the alert went out and 199 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.
411
WUUS51 KPHI 311653
SVRPHI
PAC029-045-091-311800-
/O.NEW.KPHI.SV.W.0202.250731T1653Z-250731T1800Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1253 PM EDT Thu Jul 31 2025
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Central Montgomery County in southeastern Pennsylvania...
Northeastern Chester County in southeastern Pennsylvania...
Northern Delaware County in southeastern Pennsylvania...
* Until 200 PM EDT.
* At 1253 PM EDT, a severe thunderstorm was located over Glenmoore,
or 12 miles northwest of West Chester, moving east at 20 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
* Locations impacted include...
Norristown, Pottstown, Phoenixville, West Norriton, East Norriton,
Downingtown, Collegeville, Royersford, Trappe, Schwenksville,
Elverson, Pughtown, Bryn Mawr, Radnor Township, Spring Mount,
Lionville-Marchwood, Valley Forge, Glenmoore, Paoli, and Chester
Springs.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4017 7582 4034 7535 4002 7531 4000 7582
4014 7587
TIME...MOT...LOC 1653Z 249DEG 17KT 4010 7574
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Deal2 follow-up statements
170
WWUS51 KPHI 311733
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
133 PM EDT Thu Jul 31 2025
PAC029-045-091-311800-
/O.CON.KPHI.SV.W.0202.000000T0000Z-250731T1800Z/
Montgomery PA-Chester PA-Delaware PA-
133 PM EDT Thu Jul 31 2025
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR CENTRAL MONTGOMERY...NORTHEASTERN CHESTER AND NORTHERN DELAWARE
COUNTIES...
At 133 PM EDT, a severe thunderstorm was located over Royersford, or
15 miles north of West Chester, moving east at 15 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Norristown, Pottstown, Phoenixville, West Norriton, East Norriton,
Collegeville, Royersford, Trappe, Schwenksville, Pughtown, Bryn Mawr,
Radnor Township, Spring Mount, Lionville-Marchwood, Valley Forge,
Paoli, Chester Springs, Lionville, King Of Prussia, and Skippack.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4034 7535 4002 7531 4001 7567 4010 7570
4019 7576
TIME...MOT...LOC 1733Z 262DEG 15KT 4018 7553
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Deal344
WWUS51 KPHI 311801
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
201 PM EDT Thu Jul 31 2025
PAC029-045-091-311810-
/O.EXP.KPHI.SV.W.0202.000000T0000Z-250731T1800Z/
Montgomery PA-Chester PA-Delaware PA-
201 PM EDT Thu Jul 31 2025
...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY...
NORTHEASTERN CHESTER AND NORTHERN DELAWARE COUNTIES HAS EXPIRED...
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been allowed to expire. However heavy
rain is still possible with this thunderstorm.
A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
southeastern Pennsylvania.
Remember, a Severe Thunderstorm Warning still remains in effect for
Montgomery County until 300pm.
LAT...LON 4034 7535 4002 7531 4001 7567 4010 7570
4019 7576
TIME...MOT...LOC 1800Z 249DEG 17KT 4022 7538
$$
DealThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| 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, 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, 2:05 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 40 min |
| Jul 31, 2:09 PM EDT | Flash Flood Warning | PHI | Delaware | 4 hr |
| Jul 31, 2:27 PM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 4 hr |
| Jul 31, 2:46 PM EDT | Flash Flood Warning | PHI | Delaware | 4 hr |
| Jul 31, 2:55 PM EDT | Severe Thunderstorm Warning | PHI | Philadelphia | 50 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 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.