Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 81, NWS Philadelphia/Mount Holly

June 30, 20244 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 30, 2024, 3:52 PM EDT for 4 counties in Pennsylvania. It was in force for 38 min. 1 report 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: Jun 30, 2024, 3:52 PM EDT (19:52 UTC)
Expired: Jun 30, 2024, 4:30 PM EDT
In force: 38 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Berks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 96 km from the middle of the area, began a volume at 19:52 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
Jun 30, 4:20 PM EDT	TSTM WND DMG	Phoenixville, PA	tree down on State Rd. time est. by 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.

Issued	Product	Office	Lasted
Jun 30, 11:09 AM EDT	Severe Thunderstorm Watch	SPC	10 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.9 hours before the alert went out and 207 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 958 J/kg
Mixed-layer CIN: -163 J/kg
Mixed-layer LCL: 1517 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

021 
WUUS51 KPHI 301952
SVRPHI
PAC011-029-045-091-302030-
/O.NEW.KPHI.SV.W.0081.240630T1952Z-240630T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
352 PM EDT Sun Jun 30 2024

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Berks County in eastern Pennsylvania...
  Montgomery County in southeastern Pennsylvania...
  Northeastern Chester County in southeastern Pennsylvania...
  Northeastern Delaware County in southeastern Pennsylvania...

* Until 430 PM EDT.

* At 352 PM EDT, a severe thunderstorm was located over Pughtown, or
  15 miles north of West Chester, moving east at 30 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Philadelphia, West Chester, Norristown, Pottstown, Phoenixville,
  Lansdale, West Norriton, East Norriton, Coatesville, Yeadon,
  Downingtown, Conshohocken, Hatboro, Ambler, Birdsboro,
  Collegeville, Royersford, Jenkintown, Narberth, and Trappe.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 296 and 343.
 Northeast Extension between mile markers 21 and 30.
 Interstate 76 in Pennsylvania between mile markers 327 and 338.
 Interstate 476 in Pennsylvania between mile markers 5 and 19.
 Interstate 176 in Pennsylvania between mile markers 1 and 9.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

In addition to 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.

&&

LAT...LON 4027 7604 4029 7557 4022 7515 4019 7511
      4007 7514 4009 7522 4006 7526 4001 7521
      3997 7528 3996 7525 3992 7525 4002 7595
      4011 7594 4014 7588 4024 7603
TIME...MOT...LOC 1952Z 282DEG 27KT 4017 7569 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Hoeflich

3 follow-up statements

011 
WWUS51 KPHI 302005
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
405 PM EDT Sun Jun 30 2024

PAC011-302014-
/O.CAN.KPHI.SV.W.0081.000000T0000Z-240630T2030Z/
Berks PA-
405 PM EDT Sun Jun 30 2024

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BERKS 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 700 PM EDT for
southeastern Pennsylvania.

LAT...LON 4002 7595 4029 7562 4029 7557 4022 7515
      4019 7511 4007 7514 4009 7522 4006 7526
      4001 7521 3997 7528 3996 7525 3992 7525
TIME...MOT...LOC 2004Z 289DEG 23KT 4013 7561 

$$

PAC029-045-091-302030-
/O.CON.KPHI.SV.W.0081.000000T0000Z-240630T2030Z/
Montgomery PA-Chester PA-Delaware PA-
405 PM EDT Sun Jun 30 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR MONTGOMERY...NORTHEASTERN CHESTER AND NORTHEASTERN DELAWARE
COUNTIES...

At 404 PM EDT, a severe thunderstorm was located over Chester
Springs, or 11 miles north of West Chester, moving east at 25 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Philadelphia, West Chester, Norristown, Pottstown, Phoenixville,
Lansdale, West Norriton, East Norriton, Coatesville, Yeadon,
Downingtown, Conshohocken, Hatboro, Ambler, Collegeville, Royersford,
Jenkintown, Narberth, Trappe, and East Lansdowne.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 303 and 343.
 Northeast Extension between mile markers 21 and 30.
 Interstate 76 in Pennsylvania between mile markers 327 and 338.
 Interstate 476 in Pennsylvania between mile markers 5 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4002 7595 4029 7562 4029 7557 4022 7515
      4019 7511 4007 7514 4009 7522 4006 7526
      4001 7521 3997 7528 3996 7525 3992 7525
TIME...MOT...LOC 2004Z 289DEG 23KT 4013 7561 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Hoeflich

238 
WWUS51 KPHI 302021
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
421 PM EDT Sun Jun 30 2024

PAC029-045-091-302030-
/O.CON.KPHI.SV.W.0081.000000T0000Z-240630T2030Z/
Montgomery PA-Chester PA-Delaware PA-
421 PM EDT Sun Jun 30 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR SOUTHEASTERN MONTGOMERY...NORTHEASTERN CHESTER AND NORTHEASTERN
DELAWARE COUNTIES...

At 421 PM EDT, a severe thunderstorm was located over King Of
Prussia, or 12 miles northeast of West Chester, moving east at 35
mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Norristown, Lansdale, West Norriton, East Norriton, Yeadon,
Conshohocken, Ambler, Collegeville, Narberth, East Lansdowne, Bryn
Mawr, Trout Lake, Radnor Township, Broomall, Newtown Square, King Of
Prussia, Drexel Hill, Valley Forge, Plymouth Meeting, and Paoli.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 321 and 341.
 Northeast Extension between mile markers 21 and 30.
 Interstate 76 in Pennsylvania between mile markers 327 and 338.
 Interstate 476 in Pennsylvania between mile markers 6 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4000 7554 4027 7543 4022 7515 4020 7512
      4008 7518 4009 7522 4006 7526 4001 7521
      4001 7522 3997 7528 3996 7525 3994 7525
      3992 7526 3992 7527
TIME...MOT...LOC 2021Z 289DEG 32KT 4006 7541 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Hoeflich

501 
WWUS51 KPHI 302027
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
427 PM EDT Sun Jun 30 2024

PAC029-045-091-302036-
/O.EXP.KPHI.SV.W.0081.000000T0000Z-240630T2030Z/
Montgomery PA-Chester PA-Delaware PA-
427 PM EDT Sun Jun 30 2024

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MONTGOMERY...
NORTHEASTERN CHESTER AND NORTHEASTERN DELAWARE COUNTIES WILL EXPIRE
AT 430 PM EDT...

The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 700 PM EDT for
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.

A new Severe Thunderstorm Warning was issued for southeastern 
Montgomery County, east central Chester County, and Delaware County. 
Refer to that bulletin for the updated information. 

LAT...LON 4000 7554 4027 7543 4022 7515 4020 7512
      4008 7518 4009 7522 4006 7526 4001 7521
      4001 7522 3997 7528 3996 7525 3994 7525
      3992 7526 3992 7527
TIME...MOT...LOC 2026Z 282DEG 27KT 4006 7538 

$$

Hoeflich

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 29, 8:22 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	53 min
Jun 29, 10:23 PM EDT	Flash Flood Warning	PHI	Chester	4 hr
Jun 30, 1:18 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	42 min
Jun 30, 1:57 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	48 min
Jun 30, 2:10 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	50 min
Jun 30, 2:42 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	63 min
Jun 30, 2:45 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Monroe, Northampton	45 min
Jun 30, 3:01 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	59 min
Jun 30, 3:26 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	49 min
Jun 30, 3:46 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Montgomery	44 min
Jun 30, 4:25 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	50 min
Jun 30, 4:37 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Northampton	53 min
Jun 30, 4:54 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	51 min
Jun 30, 5:19 PM EDT	Flash Flood Warning	PHI	Chester, Delaware, Philadelphia	3 hr
Jun 30, 5:20 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	40 min
Jun 30, 5:51 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	39 min
Jun 30, 5:54 PM EDT	Flash Flood Warning	PHI	Delaware, Philadelphia	3 hr
Jun 30, 7:31 PM EDT	Severe Thunderstorm Warning	PHI	Chester	44 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2024 Every severe thunderstorm warning in 2024

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.