Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 223, NWS Philadelphia/Mount Holly

July 21, 2021Cape May County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 21, 2021, 5:31 PM EDT for Cape May County, New Jersey. It was in force for 29 min. 4 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 21, 2021, 5:31 PM EDT (21:31 UTC)
Expired
Jul 21, 2021, 6:00 PM EDT
In force
29 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Cape May County, NJ

The radar

The Dover AFB radar (KDOX), 48 km from the middle of the area, began a volume at 21:35 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 21, 5:32 PM EDTTSTM WND DMGLower Township, NJTREE DOWN IN CAPE ROAD ROAD IN LOWER TOWNSHIP. TIME ESTIMATED FROM RADAR.
Jul 21, 5:33 PM EDTTSTM WND GST 581 Ssw North Cape May, NJNOS SITE AT NORTH CAPE MAY MEASURES 58MPH GUST (TIME BETWEEN 5:30 AND 5:35 PM).
Jul 21, 5:36 PM EDTTSTM WND DMG1 Nnw Cape May Harbor, NJWIRES DOWN ON OCEAN DRIVE IN CAPE MAY. TIME ESTIMATED FROM RADAR.
Jul 21, 5:36 PM EDTTSTM WND DMG1 Sw Wildwood Crest, NJTELEPHONE POLE SNAPPED IN HALF ON W PRESTON AVE IN WILDWOOD CREST. PHOTO RELAYED ON SOCIAL MEDIA. 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
Jul 21, 11:56 AM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 9.5 hours before the alert went out and 123 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 2021-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 728 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 2021-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
728 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
1221 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
-10 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

610 
WUUS51 KPHI 212131
SVRPHI
NJC009-212200-
/O.NEW.KPHI.SV.W.0223.210721T2131Z-210721T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
531 PM EDT Wed Jul 21 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Cape May County in southern New Jersey...

* Until 600 PM EDT.

* At 531 PM EDT, a severe thunderstorm was located over North Cape
  May, or near Cape May, moving east at 25 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...
  Cape May, North Wildwood, Wildwood Crest, Sea Isle City, Avalon,
  West Cape May, Stone Harbor, Cape May Court House, Scotch Bonnet,
  Diamond Beach, Green Creek, Rio Grande, North Cape May, Villas,
  West Wildwood, Erma and Whitesboro-Burleigh.

This includes Garden State Parkway between mile markers 0 and 14.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Mount Holly NJ.

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 3888 7503 3906 7507 3916 7465 3889 7483
TIME...MOT...LOC 2131Z 260DEG 22KT 3899 7496 

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

MPS
1 follow-up statement
138 
WWUS51 KPHI 212151
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
551 PM EDT Wed Jul 21 2021

NJC009-212201-
/O.EXP.KPHI.SV.W.0223.000000T0000Z-210721T2200Z/
Cape May NJ-
551 PM EDT Wed Jul 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CAPE MAY COUNTY
WILL EXPIRE AT 600 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 and heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
southern New Jersey.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 3888 7503 3906 7507 3916 7465 3889 7483
TIME...MOT...LOC 2151Z 260DEG 22KT 3903 7465 

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 11:09 AM EDTSpecial Weather StatementPHIMorris36 min
Jul 21, 12:41 PM EDTSpecial Weather StatementPHIOcean34 min
Jul 21, 12:46 PM EDTSpecial Marine WarningPHI89 min
Jul 21, 12:51 PM EDTSevere Thunderstorm WarningPHIAtlantic, Ocean39 min
Jul 21, 12:53 PM EDTSevere Thunderstorm WarningPHIOcean67 min
Jul 21, 1:28 PM EDTSevere Thunderstorm WarningPHIAtlantic47 min
Jul 21, 1:43 PM EDTSevere Thunderstorm WarningPHIOcean49 min
Jul 21, 2:10 PM EDTSpecial Marine WarningPHI95 min
Jul 21, 2:13 PM EDTSevere Thunderstorm WarningPHIBurlington47 min
Jul 21, 2:35 PM EDTSpecial Marine WarningPHI55 min
Jul 21, 2:52 PM EDTSevere Thunderstorm WarningPHIOcean26 min
Jul 21, 3:04 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester56 min
Jul 21, 3:16 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden44 min
Jul 21, 3:27 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester33 min
Jul 21, 3:43 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean47 min
Jul 21, 3:48 PM EDTSpecial Marine WarningPHI57 min
Jul 21, 3:48 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden42 min
Jul 21, 3:57 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Gloucester, Salem33 min
Jul 21, 4:04 PM EDTSpecial Marine WarningPHI56 min
Jul 21, 4:17 PM EDTSpecial Marine WarningPHI58 min
Jul 21, 4:50 PM EDTSpecial Marine WarningPHI55 min
Jul 21, 5:07 PM EDTSpecial Marine WarningPHI23 min
Jul 21, 5:09 PM EDTSpecial Marine WarningPHI66 min
Jul 21, 5:24 PM EDTSpecial Marine WarningPHI46 min
Jul 21, 5:52 PM EDTSpecial Marine WarningPHI53 min

Nearby

Severe 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.