Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 112, NWS Philadelphia/Mount Holly

July 14, 2024Chester County, Delaware County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 14, 2024, 2:52 PM EDT for Chester County, Delaware County, Montgomery County, Pennsylvania. It was in force for 38 min. 4 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: Jul 14, 2024, 2:52 PM EDT (18:52 UTC)
Expired: Jul 14, 2024, 3:30 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 Chester County, PA, Delaware County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 82 km from the middle of the area, began a volume at 18:52 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
Jul 14, 2:57 PM EDT	TSTM WND DMG	2 Nne East Brandywine T, PA	Reports of several trees and wires down around East Brandywine Township. Time estimated.
Jul 14, 3:01 PM EDT	HAIL 0.7	2 N East Brandywine Twp, PA	Report from mPING: Dime size hail.
Jul 14, 3:05 PM EDT	TSTM WND DMG	1 Wnw Uwchlan Twp, PA	Multiple large limbs down on route 100 near the turnpike. Time estimated from radar.
Jul 14, 3:07 PM EDT	TSTM WND DMG	Downington, PA	Reports of several trees and wires down around Downingtown. Time estimated.

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, 6.9 hours before the alert went out and 208 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: 940 J/kg
Mixed-layer CIN: -112 J/kg
Mixed-layer LCL: 1366 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 53 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

943 
WUUS51 KPHI 141852
SVRPHI
PAC029-045-091-141930-
/O.NEW.KPHI.SV.W.0112.240714T1852Z-240714T1930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
252 PM EDT Sun Jul 14 2024

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  South central Montgomery County in southeastern Pennsylvania...
  Northeastern Chester County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until 330 PM EDT.

* At 252 PM EDT, a severe thunderstorm was located over Chester
  Springs, or 9 miles north of West Chester, moving southeast 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...
  West Chester, Chester, Phoenixville, Yeadon, Westtown, Downingtown,
  Folcroft, Swarthmore, Narberth, East Lansdowne, Darby Township,
  Cheyney, Pughtown, Bryn Mawr, Trout Lake, Chelsea, Radnor Township,
  Gradyville, Broomall, and Newtown Square.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 308 and 326.
 Interstate 95 in Pennsylvania between mile markers 1 and 11.
 Interstate 76 in Pennsylvania between mile markers 327 and 329.
 Interstate 476 in Pennsylvania between mile markers 0 and 15.

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 4020 7564 4001 7521 3997 7528 3996 7525
      3995 7525 3994 7524 3989 7526 3987 7525
      3985 7527 3985 7533 3980 7541 4004 7578
TIME...MOT...LOC 1852Z 305DEG 21KT 4009 7564 

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

$$

Hoeflich

2 follow-up statements

949 
WWUS51 KPHI 141914
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
314 PM EDT Sun Jul 14 2024

PAC091-141924-
/O.CAN.KPHI.SV.W.0112.000000T0000Z-240714T1930Z/
Montgomery PA-
314 PM EDT Sun Jul 14 2024

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL MONTGOMERY
COUNTY IS CANCELLED...

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

LAT...LON 4015 7556 3998 7528 3997 7528 3996 7525
      3995 7525 3994 7524 3989 7526 3987 7525
      3985 7527 3985 7533 3984 7534 3984 7536
      3980 7541 4004 7578
TIME...MOT...LOC 1914Z 306DEG 13KT 4005 7558 

$$

PAC029-045-141930-
/O.CON.KPHI.SV.W.0112.000000T0000Z-240714T1930Z/
Chester PA-Delaware PA-
314 PM EDT Sun Jul 14 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR NORTHEASTERN CHESTER AND DELAWARE COUNTIES...

At 314 PM EDT, a severe thunderstorm was located near
Lionville-Marchwood, or near West Chester, moving southeast at 15
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...
West Chester, Chester, Phoenixville, Yeadon, Westtown, Downingtown,
Folcroft, Swarthmore, East Lansdowne, Darby Township, Cheyney, Trout
Lake, Chelsea, Radnor Township, Gradyville, Broomall, Newtown Square,
Chester Township, Drexel Hill, and Tinicum Township.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 310 and 324.
 Interstate 95 in Pennsylvania between mile markers 1 and 11.
 Interstate 476 in Pennsylvania between mile markers 0 and 12.

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 4015 7556 3998 7528 3997 7528 3996 7525
      3995 7525 3994 7524 3989 7526 3987 7525
      3985 7527 3985 7533 3984 7534 3984 7536
      3980 7541 4004 7578
TIME...MOT...LOC 1914Z 306DEG 13KT 4005 7558 

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

$$

Hoeflich

771 
WWUS51 KPHI 141921
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
321 PM EDT Sun Jul 14 2024

PAC029-045-141930-
/O.EXP.KPHI.SV.W.0112.000000T0000Z-240714T1930Z/
Chester PA-Delaware PA-
321 PM EDT Sun Jul 14 2024

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CHESTER AND
DELAWARE COUNTIES WILL EXPIRE AT 330 PM EDT...

The severe thunderstorm which prompted the warning has weakened.
Therefore, the warning will be allowed to expire.  However gusty 
winds are still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

Remember, a Severe Thunderstorm Warning still remains in effect for 
portions fo Chester County. Refer to that bulletin with the updated 
information. 

LAT...LON 4015 7556 3998 7528 3997 7528 3996 7525
      3995 7525 3994 7524 3989 7526 3987 7525
      3985 7527 3985 7533 3984 7534 3984 7536
      3980 7541 4004 7578
TIME...MOT...LOC 1920Z 305DEG 21KT 4005 7558 

$$

Hoeflich

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 14, 12:07 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	38 min
Jul 14, 12:44 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh, Montgomery	46 min
Jul 14, 1:23 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	52 min
Jul 14, 2:19 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Montgomery	41 min
Jul 14, 2:24 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	23 min
Jul 14, 2:53 PM EDT	Flash Flood Warning	PHI	Chester	3 hr
Jul 14, 3:03 PM EDT	Excessive Heat Warning	PHI	Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more	3 days
Jul 14, 3:03 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	42 min
Jul 14, 3:35 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	40 min
Jul 14, 3:44 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	46 min
Jul 14, 4:13 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	47 min
Jul 14, 4:22 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	Bucks	32 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.