Alert archive / New Jersey / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 274, NWS Philadelphia/Mount Holly

August 28, 2020Cumberland County, Gloucester County, Salem County, New Jersey; New Castle County, Delaware; Chester County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 28, 2020, 3:52 PM EDT for Cumberland County, Gloucester County, Salem County, New Jersey; New Castle County, Delaware; Chester County, Delaware County, Pennsylvania. It was in force for 53 min. 9 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 28, 2020, 3:52 PM EDT (19:52 UTC)
Expired
Aug 28, 2020, 4:45 PM EDT
In force
53 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties New Castle County, DE, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 94 km from the middle of the area, began a volume at 19:53 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 28, 3:55 PM EDTTSTM WND GST 60Avondale, PA
Aug 28, 3:55 PM EDTHAIL 0.25Avondale, PA
Aug 28, 4:10 PM EDTHAIL 0.88Chadds Ford Twp, PA
Aug 28, 4:20 PM EDTTSTM WND DMGMedia, PATREE AND UTILITY WIRES DOWN ON FARNUM ROAD.
Aug 28, 4:29 PM EDTTSTM WND DMG1 S Avondale, PADOWNED TREES AND WIRES NEAR MCMILLAN DRIVE IN AVONDALE. TIME ESTIMATED FROM RADAR.
Aug 28, 4:30 PM EDTHAIL 0.25Springfield, PA
Aug 28, 4:39 PM EDTTSTM WND DMG1 W Lima, PAA FEW REPORTS OF DOWNED TREES AND WIRES NEAR AND WEST OF LIMA. TIME ESTIMATED FROM RADAR.
Aug 28, 4:39 PM EDTTSTM WND DMG2 Ssw Pennsbury Twp, PADOWNED POWER LINES NEAR WEDGEWOOD DRIVE IN FAIRVILLE. TIME ESTIMATED FROM RADAR.
Aug 28, 4:45 PM EDTTSTM WND DMG1 Ese Chester Heights, PAA FEW REPORTS OF DOWNED TREES AND WIRES IN THE CHESTER HEIGHTS AND ASTON MILLS AREAS. 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
Aug 28, 1:37 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.9 hours before the alert went out and 186 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 2020-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 511 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 2020-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 square meters per square second.19395878Sfc1 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
511 J/kg
Mixed-layer CIN
-119 J/kg
Mixed-layer LCL
1109 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

000 
WUUS51 KPHI 281952
SVRPHI
DEC003-NJC011-015-033-PAC029-045-282045-
/O.NEW.KPHI.SV.W.0274.200828T1952Z-200828T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
352 PM EDT Fri Aug 28 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northern New Castle County in northern Delaware...
  Northwestern Cumberland County in southern New Jersey...
  Salem County in southern New Jersey...
  Northwestern Gloucester County in southern New Jersey...
  South central Chester County in southeastern Pennsylvania...
  Southern Delaware County in southeastern Pennsylvania...

* Until 445 PM EDT.

* At 352 PM EDT, severe thunderstorms were located along a line
  extending from Kennett Square to near Bear to Hope Creek, moving
  east at 30 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...
  Wilmington, Newark, Chester, Pennsville, Carneys Point, Folcroft,
  Swarthmore, Elsmere, Paulsboro, Kennett Square, New Castle, Penns
  Grove, Salem, Woodstown, Alloway, Quinton, Swedesboro, Delaware
  City, Elmer and Newport.

This includes the following highways...
 New Jersey Turnpike between exits 1 and 2.
 Interstate 95 in Pennsylvania between mile markers 0 and 10.
 Interstate 95 in Delaware between mile markers 2 and 23.
 Interstate 295 in New Jersey between mile markers 0 and 18.
 Interstate 476 in Pennsylvania between mile markers 0 and 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 3994 7528 3948 7514 3944 7558 3958 7573
      3988 7583
TIME...MOT...LOC 1952Z 262DEG 28KT 3982 7573 3960 7565 3949 7555 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann
1 follow-up statement
610 
WWUS51 KPHI 282010
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
410 PM EDT Fri Aug 28 2020

DEC003-NJC011-015-033-PAC029-045-282045-
/O.CON.KPHI.SV.W.0274.000000T0000Z-200828T2045Z/
New Castle DE-Cumberland NJ-Salem NJ-Gloucester NJ-Chester PA-
Delaware PA-
410 PM EDT Fri Aug 28 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR NORTHEASTERN NEW CASTLE...NORTHWESTERN CUMBERLAND...SALEM...
NORTHWESTERN GLOUCESTER...SOUTH CENTRAL CHESTER AND SOUTHERN DELAWARE
COUNTIES...

At 410 PM EDT, severe thunderstorms were located along a line
extending from near Elam to near Salem to near Hancocks Bridge,
moving east at 30 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...
Wilmington, Chester, Pennsville, Carneys Point, Folcroft, Swarthmore,
Elsmere, Paulsboro, New Castle, Penns Grove, Salem, Woodstown,
Alloway, Quinton, Swedesboro, Delaware City, Elmer, Newport, Arden
and Darby Township.

This includes the following highways...
 New Jersey Turnpike between exits 1 and 2.
 Interstate 95 in Pennsylvania between mile markers 0 and 10.
 Interstate 95 in Delaware between mile markers 9 and 23.
 Interstate 295 in New Jersey between mile markers 0 and 17.
 Interstate 476 in Pennsylvania between mile markers 0 and 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 3994 7528 3948 7515 3945 7547 3956 7560
      3990 7568
TIME...MOT...LOC 2010Z 266DEG 26KT 3985 7559 3957 7552 3949 7542 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 8:13 PM EDTSevere Thunderstorm WarningPHIHunterdon, Somerset, Warren47 min
Aug 27, 8:24 PM EDTSpecial Weather StatementPHIMiddlesex, Somerset51 min
Aug 27, 8:29 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset46 min
Aug 27, 8:55 PM EDTSpecial Marine WarningPHI95 min
Aug 27, 9:13 PM EDTSpecial Weather StatementPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset47 min
Aug 27, 9:28 PM EDTSevere Thunderstorm WarningPHIMercer, Middlesex, Monmouth, Ocean, Somerset47 min
Aug 28, 3:05 PM EDTSpecial Marine WarningPHI85 min
Aug 28, 3:41 PM EDTSpecial Weather StatementPHISalem34 min
Aug 28, 3:53 PM EDTSpecial Marine WarningPHI67 min
Aug 28, 4:07 PM EDTSpecial Marine WarningPHI53 min
Aug 28, 4:17 PM EDTSevere Thunderstorm WarningPHICape May43 min
Aug 28, 4:29 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Mercer61 min
Aug 28, 4:39 PM EDTSevere Thunderstorm WarningPHICamden, Cumberland, Gloucester, Salem66 min
Aug 28, 4:49 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean56 min
Aug 28, 4:55 PM EDTSpecial Marine WarningPHI95 min
Aug 28, 5:13 PM EDTSpecial Marine WarningPHI92 min
Aug 28, 5:28 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more47 min
Aug 28, 5:37 PM EDTSpecial Marine WarningPHI83 min
Aug 28, 5:51 PM EDTSpecial Marine WarningPHI84 min
Aug 28, 6:53 PM EDTSpecial Marine WarningPHI64 min
Aug 28, 7:55 PM EDTSpecial Marine WarningPHI65 min
Aug 28, 1:53 PM EDTSevere Thunderstorm WarningPHINew Castle52 min
Aug 28, 2:40 PM EDTSevere Thunderstorm WarningPHIKent, New Castle50 min
Aug 28, 3:15 PM EDTSpecial Weather StatementPHINew Castle30 min
Aug 28, 3:21 PM EDTSevere Thunderstorm WarningPHIKent, New Castle24 min
Aug 28, 4:01 PM EDTSevere Thunderstorm WarningPHINew Castle44 min
Aug 28, 5:40 PM EDTSpecial Weather StatementPHIKent35 min
Aug 28, 6:17 PM EDTSevere Thunderstorm WarningPHIKent, Sussex43 min
Aug 28, 7:53 PM EDTSpecial Weather StatementPHISussex37 min
Aug 27, 8:26 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery26 min
Aug 28, 3:22 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery53 min
Aug 28, 3:33 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Chester, Lehigh, Montgomery101 min
Aug 28, 3:36 PM EDTSevere Thunderstorm WarningPHIBerks, Chester54 min
Aug 28, 3:56 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia49 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2020Severe Thunderstorm Warnings in Pennsylvania, 2020Severe Thunderstorm Warnings in Delaware, 2020Every severe thunderstorm warning in 2020

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.