Alert archive / New Jersey / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 236, NWS Philadelphia/Mount Holly

August 12, 20205 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 12, 2020, 3:12 PM EDT for 5 counties in New Jersey. It was in force for 29 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
Aug 12, 2020, 3:12 PM EDT (19:12 UTC)
Expired
Aug 12, 2020, 3:41 PM EDT
In force
29 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Salem County, NJ

The radar

The Philadelphia radar (KDIX), 52 km from the middle of the area, began a volume at 19:16 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 12, 3:16 PM EDTTSTM WND DMG2 Se Waterford Works, NJSEVERAL REPORTS OF POWER LINES DOWN NEAR ANCORA AND CHESILHURST. TIME ESTIMATED FROM RADAR.
Aug 12, 3:18 PM EDTTSTM WND DMG2 Ese Winslow Twp, NJDOWNED POWER LINES NORTHWEST OF HAMMONTON. TIME ESTIMATED FROM RADAR.
Aug 12, 3:25 PM EDTTSTM WND DMG1 S Sewell, NJLARGE TREE DOWN ON NEW ST. 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 7.2 hours before the alert went out and 202 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, Wallops Is Stn, VA at 12:00Z on 2020-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1590 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, Wallops Is Stn, VA at 12:00Z on 2020-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 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
1590 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
729 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
17 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

049 
WUUS51 KPHI 121912
SVRPHI
NJC001-005-007-015-033-122000-
/O.NEW.KPHI.SV.W.0236.200812T1912Z-200812T2000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
312 PM EDT Wed Aug 12 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Atlantic County in southern New Jersey...
  Eastern Salem County in southern New Jersey...
  Camden County in southern New Jersey...
  Gloucester County in southern New Jersey...
  Southwestern Burlington County in southern New Jersey...

* Until 400 PM EDT.

* At 312 PM EDT, a severe thunderstorm was located near Chesilhurst,
  or 17 miles northeast of Vineland, and is nearly stationary.

  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...
  Deptford, West Deptford, Glassboro, Lindenwold, Hammonton,
  Woodbury, Pitman, Clayton, Berlin, Shamong, Paulsboro, Westville,
  Egg Harbor City, Woodbury Heights, National Park, Chesilhurst,
  Franklinville, Sicklerville, Elwood-Magnolia and Atsion.

This includes the following highways...
 Interstate 295 in New Jersey between mile markers 19 and 25.
 Atlantic City Expressway between mile markers 24 and 44.

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.

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3957 7460 3958 7512 3976 7524 3986 7523
      3987 7521 3978 7456
TIME...MOT...LOC 1912Z 271DEG 1KT 3968 7485 

HAIL...0.75IN
WIND...60MPH
 
$$

CMS
2 follow-up statements
832 
WWUS51 KPHI 121931
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
331 PM EDT Wed Aug 12 2020

NJC033-121940-
/O.CAN.KPHI.SV.W.0236.000000T0000Z-200812T2000Z/
Salem NJ-
331 PM EDT Wed Aug 12 2020

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN SALEM 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 3957 7460 3958 7508 3961 7511 3980 7506
      3983 7495 3978 7456
TIME...MOT...LOC 1930Z 271DEG 1KT 3968 7484 

$$

NJC001-005-007-015-122000-
/O.CON.KPHI.SV.W.0236.000000T0000Z-200812T2000Z/
Atlantic NJ-Camden NJ-Gloucester NJ-Burlington NJ-
331 PM EDT Wed Aug 12 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM EDT
FOR NORTHWESTERN ATLANTIC...SOUTHERN CAMDEN...SOUTHEASTERN GLOUCESTER
AND SOUTHWESTERN BURLINGTON COUNTIES...

At 330 PM EDT, a severe thunderstorm was located near Chesilhurst, or
16 miles northeast of Vineland, and is nearly stationary.

HAZARD...60 mph wind gusts.

SOURCE...Law enforcement. This storm has produced wind damage in 
         Camden and Gloucester Counties.

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

Locations impacted include...
Glassboro, Lindenwold, Hammonton, Clayton, Berlin, Shamong, Egg
Harbor City, Chesilhurst, Franklinville, Sicklerville,
Elwood-Magnolia, Atsion, Atco, Victory Lakes, Wharton State Forest,
Williamstown, Batsto, Marlton Lakes, Turnersville and Monroe
Township.

This includes Atlantic City Expressway between mile markers 24 and
44.
 
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 this storm. 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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3957 7460 3958 7508 3961 7511 3980 7506
      3983 7495 3978 7456
TIME...MOT...LOC 1930Z 271DEG 1KT 3968 7484 

HAIL...<.75IN
WIND...60MPH
 
$$

CMS
555 
WWUS51 KPHI 121941
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
341 PM EDT Wed Aug 12 2020

NJC001-005-007-015-121951-
/O.CAN.KPHI.SV.W.0236.000000T0000Z-200812T2000Z/
Atlantic NJ-Camden NJ-Gloucester NJ-Burlington NJ-
341 PM EDT Wed Aug 12 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN ATLANTIC...
SOUTHERN CAMDEN...SOUTHEASTERN GLOUCESTER AND SOUTHWESTERN BURLINGTON
COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However, gusty winds and 
heavy rain are still possible with this thunderstorm.

LAT...LON 3957 7460 3958 7508 3961 7511 3980 7506
      3983 7495 3978 7456
TIME...MOT...LOC 1940Z 271DEG 1KT 3968 7484 

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 12:06 PM EDTSpecial Weather StatementPHIMonmouth24 min
Aug 12, 12:16 PM EDTSpecial Weather StatementPHIBurlington29 min
Aug 12, 12:33 PM EDTSevere Thunderstorm WarningPHIBurlington42 min
Aug 12, 12:43 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Mercer, Monmouth, Ocean and 1 more3 hr
Aug 12, 12:45 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean45 min
Aug 12, 1:12 PM EDTFlash Flood WarningPHIBurlington3 hr
Aug 12, 1:12 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Monmouth, Ocean48 min
Aug 12, 1:25 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean50 min
Aug 12, 1:54 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester51 min
Aug 12, 1:57 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Ocean48 min
Aug 12, 2:40 PM EDTFlash Flood WarningPHIBurlington, Camden, Gloucester3 hr
Aug 12, 2:42 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean25 min
Aug 12, 2:44 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester46 min
Aug 12, 3:54 PM EDTSpecial Marine WarningPHI53 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 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.