Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 246, NWS Philadelphia/Mount Holly

August 10, 2021Delaware County, Philadelphia County, Pennsylvania; Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 10, 2021, 8:02 PM EDT for Delaware County, Philadelphia County, Pennsylvania; Camden County, Gloucester County, New Jersey. It was in force for 43 min. 8 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
Aug 10, 2021, 8:02 PM EDT (00:02 UTC)
Expired
Aug 10, 2021, 8:45 PM EDT
In force
43 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Camden County, NJ, Gloucester County, NJ, Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 79 km from the middle of the area, began a volume at 00:05 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
Aug 10, 8:03 PM EDTTSTM WND DMG1 Wsw Parkside, PATREE AND WIRES DOWN ON SUSAN LN NEAR ARLINGTON AVE. TIME ESTIMATED FROM RADAR.
Aug 10, 8:05 PM EDTTSTM WND DMG1 Sse Ridley Park, PATREE AND WIRES DOWN NEAR SELLERS AVE AT INDUSTRIAL HIGHWAY. TIME ESTIMATED FROM RADAR.
Aug 10, 8:13 PM EDTTSTM WND DMGMorton, PATREES AND WIRES DOWN ON SPRINGHILL RD. TIME ESTIMATED FROM RADAR.
Aug 10, 8:25 PM EDTTSTM WND DMGSwarthmore, PATREE AND WIRES DOWN NEAR THE INTERSECTION OF RUTGERS AVE AT HARVARD AVE. TIME ESTIMATED FROM RADAR.
Aug 10, 8:26 PM EDTTSTM WND DMGDarby Twp, PAWIRES DOWN ON ACADEMY AVE NEAR GLEN CIRCLE. TIME ESTIMATED FROM RADAR.
Aug 10, 8:27 PM EDTTSTM WND DMG1 Nne Woodlyn, PADOWNED TREE AND WIRES NEAR EISENHOWER AVE AT CATHERINE AVE. TIME ESTIMATED FROM RADAR.
Aug 10, 8:30 PM EDTTSTM WND DMGPrimos, PATREE AND WIRES DOWN NEAR THE INTERSECTION OF BISHOP AVE AND BROADWAY AVE. TIME ESTIMATED FROM RADAR.
Aug 10, 8:35 PM EDTTSTM WND GST 561 Wsw Philadelphia Inte, PAITWS SENSOR AT PHILADELPHIA INTERNATIONAL AIRPORT.

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 00:00Z, 0.0 hours before the alert went out and 204 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 00:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 00:00Z on 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 142 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1735 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
142 m²/s²
0-3 km storm-relative helicity
210 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

488 
WUUS51 KPHI 110002
SVRPHI
NJC007-015-PAC045-101-110045-
/O.NEW.KPHI.SV.W.0246.210811T0002Z-210811T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
802 PM EDT Tue Aug 10 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Camden County in southern New Jersey...
  Northwestern Gloucester County in southern New Jersey...
  Southwestern Philadelphia County in southeastern Pennsylvania...
  Southeastern Delaware County in southeastern Pennsylvania...

* Until 845 PM EDT.

* At 801 PM EDT, a severe thunderstorm was located over Gibbstown, or
  12 miles northeast of Wilmington, moving northeast at 20 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Philadelphia, Camden, Gloucester City, Chester, Deptford, Voorhees,
  West Deptford, Lindenwold, Bellmawr, Yeadon, Woodbury, Folcroft,
  Swarthmore, Paulsboro, Magnolia, Westville, Woodbury Heights,
  National Park, East Lansdowne and Swedesboro.

This includes the following highways...
 New Jersey Turnpike between exits 2 and 3.
 Interstate 95 in Pennsylvania between mile markers 1 and 25.
 Interstate 76 in Pennsylvania between mile markers 340 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 9 and 33.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 676 in New Jersey between mile markers 0 and 4.
 Interstate 476 in Pennsylvania between mile markers 0 and 1.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3973 7537 3979 7542 3980 7541 3981 7544
      3983 7545 4005 7514 3983 7494
TIME...MOT...LOC 0001Z 237DEG 18KT 3981 7532 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 8:18 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery42 min
Aug 10, 8:36 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Montgomery, Philadelphia39 min
Aug 10, 8:43 PM EDTAreal Flood AdvisoryPHIDelaware, Montgomery, Philadelphia2 hr
Aug 11, 2:56 PM EDTExcessive Heat WatchPHIBerks, Bucks, Chester, Lehigh, Montgomery, Northampton12 hr
Aug 11, 4:46 PM EDTSpecial Weather StatementPHIMonroe44 min
Aug 11, 4:58 PM EDTSpecial Weather StatementPHIBerks47 min
Aug 11, 5:20 PM EDTAreal Flood AdvisoryPHICarbon, Monroe57 min
Aug 11, 5:48 PM EDTSevere Thunderstorm WarningPHIBerks57 min
Aug 11, 6:16 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh, Montgomery44 min
Aug 11, 6:26 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Delaware, Montgomery49 min
Aug 11, 6:48 PM EDTSevere Thunderstorm WarningPHIBucks, Lehigh, Montgomery, Northampton42 min
Aug 11, 6:50 PM EDTAreal Flood AdvisoryPHIMonroe, Northampton3 hr
Aug 11, 7:04 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more2 hr
Aug 11, 7:11 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia49 min
Aug 10, 8:23 PM EDTSpecial Marine WarningPHI79 min
Aug 10, 9:07 PM EDTSpecial Weather StatementPHIBurlington, Camden, Cumberland23 min
Aug 11, 5:57 PM EDTSpecial Weather StatementPHISussex48 min
Aug 11, 6:32 PM EDTSpecial Weather StatementPHIMorris, Sussex, Warren28 min
Aug 11, 7:04 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren41 min
Aug 11, 7:28 PM EDTFlash Flood WarningPHIMorris, Warren3 hr
Aug 11, 7:45 PM EDTSpecial Weather StatementPHIMorris45 min
Aug 11, 7:52 PM EDTSpecial Weather StatementPHIAtlantic, Burlington, Camden, Gloucester, Mercer53 min
Aug 11, 7:57 PM EDTSpecial Weather StatementPHIHunterdon, Middlesex, Somerset48 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021Severe Thunderstorm Warnings in New Jersey, 2021Every severe thunderstorm warning in 2021

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.