Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 113, NWS Philadelphia/Mount Holly

July 14, 2024Chester County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 14, 2024, 3:03 PM EDT for Chester County, Delaware County, Pennsylvania. It was in force for 42 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
Jul 14, 2024, 3:03 PM EDT (19:03 UTC)
Expired
Jul 14, 2024, 3:45 PM EDT
In force
42 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Chester County, PA, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 124 km from the middle of the area, began a volume at 19:02 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
Jul 14, 3:07 PM EDTTSTM WND DMGCoatesville, PAReports of several trees and wires down around Coatesville. Time estimated.
Jul 14, 3:07 PM EDTTSTM WND DMGDownington, PAReports of several trees and wires down around Downingtown. Time estimated.
Jul 14, 3:15 PM EDTHAIL 0.7Caln Twp, PADime size hail in Caln Township. Time estimated from 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, 7.1 hours before the alert went out and 175 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, Washington/Dulle, VA at 12:00Z on 2024-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 940 joules per kilogram.LCLLFCEL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 2024-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 square meters per square second.193958Sfc1 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
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.

904 
WUUS51 KPHI 141903
SVRPHI
PAC029-045-141945-
/O.NEW.KPHI.SV.W.0113.240714T1903Z-240714T1945Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Central Chester County in southeastern Pennsylvania...
  West central Delaware County in southeastern Pennsylvania...

* Until 345 PM EDT.

* At 303 PM EDT, a severe thunderstorm was located over Coatesville,
  or 13 miles west of West Chester, moving east at 15 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...
  West Chester, Coatesville, Downingtown, Kennett Square, Parkesburg,
  Honey Brook, Marshallton, Glenmoore, Atglen, South Coatesville,
  Modena, and Thorndale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4004 7593 4006 7594 4009 7591 4009 7575
      3989 7552 3982 7566 3993 7599 3994 7598
      3995 7600
TIME...MOT...LOC 1903Z 285DEG 14KT 3999 7585 

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

$$

Hoeflich
2 follow-up statements
153 
WWUS51 KPHI 141931
SVSPHI

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

PAC045-141940-
/O.CAN.KPHI.SV.W.0113.000000T0000Z-240714T1945Z/
Delaware PA-
331 PM EDT Sun Jul 14 2024

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL DELAWARE COUNTY
IS CANCELLED...

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

LAT...LON 3996 7599 4006 7577 3991 7556 3983 7570
      3993 7599 3994 7598 3995 7600
TIME...MOT...LOC 1930Z 324DEG 11KT 3995 7581 

$$

PAC029-141945-
/O.CON.KPHI.SV.W.0113.000000T0000Z-240714T1945Z/
Chester PA-
331 PM EDT Sun Jul 14 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR CENTRAL CHESTER COUNTY...

At 330 PM EDT, a severe thunderstorm was located over Coatesville, or
10 miles west of West Chester, moving southeast at 10 mph.

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

SOURCE...Radar indicated. At 3:05, several trees were reported down 
         within western and northern Chester County. 

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

Locations impacted include...
Coatesville, Downingtown, Kennett Square, Parkesburg, Marshallton,
Atglen, South Coatesville, Modena, and Thorndale.

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 3996 7599 4006 7577 3991 7556 3983 7570
      3993 7599 3994 7598 3995 7600
TIME...MOT...LOC 1930Z 324DEG 11KT 3995 7581 

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

$$

Hoeflich
529 
WWUS51 KPHI 141936
SVSPHI

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

PAC029-141946-
/O.EXP.KPHI.SV.W.0113.000000T0000Z-240714T1945Z/
Chester PA-
336 PM EDT Sun Jul 14 2024

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL CHESTER COUNTY WILL
EXPIRE AT 345 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.

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

LAT...LON 3996 7599 4006 7577 3991 7556 3983 7570
      3993 7599 3994 7598 3995 7600
TIME...MOT...LOC 1936Z 285DEG 14KT 3995 7579 

$$

Hoeflich

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 12:07 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh38 min
Jul 14, 12:44 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh, Montgomery46 min
Jul 14, 1:23 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery52 min
Jul 14, 2:19 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery41 min
Jul 14, 2:24 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia23 min
Jul 14, 2:52 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery38 min
Jul 14, 2:53 PM EDTFlash Flood WarningPHIChester3 hr
Jul 14, 3:03 PM EDTExcessive Heat WarningPHIBerks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more3 days
Jul 14, 3:35 PM EDTSevere Thunderstorm WarningPHIChester, Delaware40 min
Jul 14, 3:44 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia46 min
Jul 14, 4:13 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia47 min
Jul 14, 4:22 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIBucks32 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2024Every 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.