Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 27, NWS Philadelphia/Mount Holly

June 14, 2024Delaware County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 14, 2024, 5:17 PM EDT for Delaware County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 43 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
Jun 14, 2024, 5:17 PM EDT (21:17 UTC)
Expired
Jun 14, 2024, 6:00 PM EDT
In force
43 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 73 km from the middle of the area, began a volume at 21:18 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
Jun 14, 5:42 PM EDTTSTM WND DMG1 Ssw Gladwyne, PATrees down in Lower Merion Township, PA. Time estimated from radar.
Jun 14, 5:50 PM EDTTSTM WND DMG1 Nne Belmont, PADowned tree on I-76 eastbound between Exit 342: US 13/30 WEST - GIRARD AVE/PHILA ZOO and Exit 343: SPRING GARDEN ST/HAVERFORD AVE. There is a lane restriction. 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
Jun 14, 4:57 PM EDTSevere Thunderstorm WatchSPC3 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.3 hours before the alert went out and 219 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 2024-06-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 50 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 2024-06-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.1939Sfc1 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
50 J/kg
Mixed-layer CIN
-171 J/kg
Mixed-layer LCL
1393 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

070 
WUUS51 KPHI 142117
SVRPHI
PAC045-091-101-142200-
/O.NEW.KPHI.SV.W.0027.240614T2117Z-240614T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
517 PM EDT Fri Jun 14 2024

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Northwestern Philadelphia County in southeastern Pennsylvania...
  Northeastern Delaware County in southeastern Pennsylvania...

* Until 600 PM EDT.

* At 516 PM EDT, a severe thunderstorm was located over Bryn Mawr, or
  8 miles west of Philadelphia, moving east at 10 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, Conshohocken, Narberth, Morris Park, Germantown, Bryn
  Mawr, Roxborough, Chestnut Hill, Trout Lake, Center City, Radnor
  Township, Plymouth Meeting, King Of Prussia, West Conshohocken,
  Penn Wynne, Glenside, Ardmore, Wyndmoor, Wyncote, and Flourtown.

This includes the following highways...
 Interstate 76 in Pennsylvania between mile markers 330 and 343.
 Interstate 476 in Pennsylvania near mile marker 10, and between mile
markers 14 and 17.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3999 7535 4008 7535 4011 7514 3996 7514
TIME...MOT...LOC 2116Z 267DEG 10KT 4003 7530 

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

$$

AKL
1 follow-up statement
930 
WWUS51 KPHI 142130
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
530 PM EDT Fri Jun 14 2024

PAC045-142139-
/O.CAN.KPHI.SV.W.0027.000000T0000Z-240614T2200Z/
Delaware PA-
530 PM EDT Fri Jun 14 2024

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DELAWARE 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 900 PM EDT for
southeastern Pennsylvania.

LAT...LON 4000 7529 4007 7529 4011 7514 3998 7514
TIME...MOT...LOC 2129Z 261DEG 12KT 4004 7523 

$$

PAC091-101-142200-
/O.CON.KPHI.SV.W.0027.000000T0000Z-240614T2200Z/
Montgomery PA-Philadelphia PA-
530 PM EDT Fri Jun 14 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR SOUTHEASTERN MONTGOMERY AND NORTHWESTERN PHILADELPHIA COUNTIES...

At 529 PM EDT, a severe thunderstorm was located over Chestnut Hill,
or near Philadelphia, 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...
Philadelphia, Narberth, Center City, Roxborough, Chestnut Hill,
Germantown, Glenside, Wyndmoor, Wyncote, Ardmore, and Flourtown.

This includes Interstate 76 in Pennsylvania between mile markers 334
and 341.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4000 7529 4007 7529 4011 7514 3998 7514
TIME...MOT...LOC 2129Z 261DEG 12KT 4004 7523 

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

$$

AKL

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 14, 4:14 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton46 min
Jun 14, 4:37 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh38 min
Jun 14, 4:40 PM EDTSevere Thunderstorm WarningPHIBucks, Lehigh, Northampton50 min
Jun 14, 5:07 PM EDTFlash Flood WarningPHIChester4 hr
Jun 14, 5:23 PM EDTSevere Thunderstorm WarningPHIBucks52 min
Jun 14, 5:37 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia38 min
Jun 14, 5:59 PM EDTFlash Flood WarningPHIBucks, Montgomery, Philadelphia4 hr
Jun 14, 6:09 PM EDTSevere Thunderstorm WarningPHIBucks21 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.