Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 43, NWS Philadelphia/Mount Holly

May 16, 20254 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 16, 2025, 11:22 AM EDT for 4 counties in Pennsylvania. It was in force for 53 min. 2 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
May 16, 2025, 11:22 AM EDT (15:22 UTC)
Expired
May 16, 2025, 12:15 PM EDT
In force
53 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Bucks County, PA, Chester County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 77 km from the middle of the area, began a volume at 15:21 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

TimeReportWhereRemark
May 16, 12:05 PM EDTTSTM WND DMG1 N Shawmont - Philadel, PASeveral large trees down in the Andorra part of Philadelphia. Time estimated from radar.
May 16, 12:06 PM EDTTSTM WND DMGPhiladelphia, PATelephone pole into a roof. Time estimated from radar.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 16, 10:06 AM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 3.4 hours before the alert went out and 210 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.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2025-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2025-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
572 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

742 
WUUS51 KPHI 161522
SVRPHI
PAC017-029-091-101-161615-
/O.NEW.KPHI.SV.W.0043.250516T1522Z-250516T1615Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1122 AM EDT Fri May 16 2025

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Montgomery County in southeastern Pennsylvania...
  Central Bucks County in southeastern Pennsylvania...
  Northeastern Chester County in southeastern Pennsylvania...
  Northern Philadelphia County in southeastern Pennsylvania...

* Until 1215 PM EDT.

* At 1122 AM EDT, a severe thunderstorm was located near Spring 
  Mount, or 21 miles east of Reading, moving east at 35 mph. This 
  storm has a history of producing wind damage in Berks County.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Philadelphia, Bensalem, Norristown, Pottstown, Phoenixville,
  Lansdale, West Norriton, East Norriton, Perkasie, Doylestown,
  Conshohocken, Palmyra, Hatboro, Souderton, Ambler, Collegeville,
  Royersford, Jenkintown, Chalfont, and Trappe.

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 4027 7568 4043 7554 4035 7494 4033 7494
      4032 7490 4027 7485 4014 7486 3998 7508
      4022 7570
TIME...MOT...LOC 1522Z 284DEG 31KT 4028 7553 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

Staarmann
3 follow-up statements
132 
WWUS51 KPHI 161539
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1139 AM EDT Fri May 16 2025

PAC029-161549-
/O.CAN.KPHI.SV.W.0043.000000T0000Z-250516T1615Z/
Chester PA-
1139 AM EDT Fri May 16 2025

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CHESTER COUNTY IS
CANCELLED...

The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 500 PM EDT for
southern and central New Jersey...and southeastern Pennsylvania.

LAT...LON 4026 7547 4036 7542 4033 7494 4032 7490
      4027 7485 4014 7486 3998 7508 4015 7550
TIME...MOT...LOC 1539Z 284DEG 31KT 4025 7536 

$$

PAC017-091-101-161615-
/O.CON.KPHI.SV.W.0043.000000T0000Z-250516T1615Z/
Montgomery PA-Bucks PA-Philadelphia PA-
1139 AM EDT Fri May 16 2025

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1215 PM EDT
FOR MONTGOMERY...SOUTHERN BUCKS AND NORTHERN PHILADELPHIA COUNTIES...

At 1139 AM EDT, a severe thunderstorm was located near Hatfield, or
20 miles northwest of Philadelphia, moving east at 35 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Philadelphia, Bensalem, Norristown, Lansdale, West Norriton, East
Norriton, Doylestown, Conshohocken, Palmyra, Hatboro, Souderton,
Ambler, Collegeville, Jenkintown, Chalfont, Trappe, Hatfield,
Rockledge, Newtown, and Abington.

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 4026 7547 4036 7542 4033 7494 4032 7490
      4027 7485 4014 7486 3998 7508 4015 7550
TIME...MOT...LOC 1539Z 284DEG 31KT 4025 7536 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Staarmann
502 
WWUS51 KPHI 161555
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1155 AM EDT Fri May 16 2025

PAC017-091-101-161615-
/O.CON.KPHI.SV.W.0043.000000T0000Z-250516T1615Z/
Montgomery PA-Bucks PA-Philadelphia PA-
1155 AM EDT Fri May 16 2025

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1215 PM EDT
FOR SOUTHEASTERN MONTGOMERY...SOUTHEASTERN BUCKS AND NORTHERN
PHILADELPHIA COUNTIES...

At 1154 AM EDT, a severe thunderstorm was located near Lansdale, or
14 miles northwest of Philadelphia, moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Philadelphia, Bensalem, Norristown, Lansdale, West Norriton, East
Norriton, Doylestown, Conshohocken, Palmyra, Hatboro, Ambler,
Collegeville, Jenkintown, Chalfont, Hatfield, Rockledge, Newtown,
Abington, Langhorne, and Bryn Athyn.

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 4024 7535 4034 7527 4032 7490 4027 7485
      4014 7486 3998 7508 4015 7550
TIME...MOT...LOC 1554Z 287DEG 28KT 4020 7525 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Staarmann
332 
WWUS51 KPHI 161608
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1208 PM EDT Fri May 16 2025

PAC017-091-101-161617-
/O.EXP.KPHI.SV.W.0043.000000T0000Z-250516T1615Z/
Montgomery PA-Bucks PA-Philadelphia PA-
1208 PM EDT Fri May 16 2025

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MONTGOMERY...
SOUTHEASTERN BUCKS AND NORTHERN PHILADELPHIA COUNTIES WILL EXPIRE AT
1215 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 gusty 
winds and heavy rainfall leading to flash flooding are still 
possible with this thunderstorm. A Flash Flood Warning remains in 
effect until 330 PM EDT for portions of this area.

A Severe Thunderstorm Watch remains in effect until 500 PM EDT for
southern and central 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 4024 7535 4034 7527 4032 7490 4027 7485
      4014 7486 3998 7508 4015 7550
TIME...MOT...LOC 1607Z 284DEG 31KT 4018 7513 

$$

Staarmann

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 9:34 PM EDTDense Fog AdvisoryPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more12 hr
May 16, 10:24 AM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Carbon, Chester, Lehigh, Monroe and 2 more66 min
May 16, 11:16 AM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia59 min
May 16, 11:32 AM EDTFlash Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia4 hr
May 16, 11:41 AM EDTFlash Flood WarningPHIChester, Delaware4 hr
May 16, 12:20 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia40 min
May 16, 12:21 PM EDTFlash Flood WarningPHIBucks, Montgomery4 hr
May 16, 2:02 PM EDTRiver Flood WarningPHIChester5 hr
May 16, 3:29 PM EDTAreal Flood WarningPHIBerks6 hr
May 16, 3:53 PM EDTAreal Flood WarningPHIMontgomery100 min
May 16, 4:42 PM EDTAreal Flood WarningPHIMontgomery, Philadelphia4 hr
May 16, 5:15 PM EDTAreal Flood WarningPHIBucks112 min
May 16, 6:43 PM EDTAreal Flood WarningPHIPhiladelphia113 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.