Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 9, NWS Philadelphia/Mount Holly

April 21, 2021Sussex County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 21, 2021, 12:51 PM EDT for Sussex County, Warren County, New Jersey. It was in force for 21 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 21, 2021, 12:51 PM EDT (16:51 UTC)
Expired: Apr 21, 2021, 1:12 PM EDT
In force: 21 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Sussex County, NJ, Warren County, NJ

The radar

The Philadelphia radar (KDIX), 137 km from the middle of the area, began a volume at 16:51 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 21, 12:28 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 4.9 hours before the alert went out and 169 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1427 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 206 m²/s²
0-3 km storm-relative helicity: 201 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

318 
WUUS51 KPHI 211651
SVRPHI
NJC037-041-211730-
/O.NEW.KPHI.SV.W.0009.210421T1651Z-210421T1730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1251 PM EDT Wed Apr 21 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Sussex County in northwestern New Jersey...
  Northern Warren County in northwestern New Jersey...

* Until 130 PM EDT.

* At 1251 PM EDT, a severe thunderstorm was located over
  Flatbrookville, or 9 miles west of Newton, moving northeast at 35
  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...
  Newton, Montague, Hopatcong, Blairstown, Franklin, Hamburg,
  Ogdensburg, Sussex, Branchville, Andover, Flatbrookville, High
  Point, Lake Mohawk, Greendell, Millbrook, Five Points, Pellettown,
  Crandon Lakes and Hainesville.

This includes Interstate 80 in New Jersey near mile marker 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 4129 7454 4103 7457 4096 7464 4093 7510
      4099 7513 4104 7503 4106 7501 4109 7497
      4109 7499 4110 7498 4116 7490 4127 7484
      4135 7475 4136 7469
TIME...MOT...LOC 1651Z 234DEG 32KT 4110 7493 

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

Davis

1 follow-up statement

214 
WWUS51 KPHI 211712
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
112 PM EDT Wed Apr 21 2021

NJC037-041-211722-
/O.CAN.KPHI.SV.W.0009.000000T0000Z-210421T1730Z/
Sussex NJ-Warren NJ-
112 PM EDT Wed Apr 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR SUSSEX AND NORTHERN WARREN
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 small hail and
gusty winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
northern and northwestern New Jersey.

LAT...LON 4129 7454 4103 7457 4096 7464 4093 7510
      4099 7513 4104 7503 4106 7501 4109 7497
      4109 7499 4110 7498 4116 7490 4127 7484
      4135 7475 4136 7469
TIME...MOT...LOC 1708Z 234DEG 32KT 4121 7473 

$$

Davis

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 8:48 PM EDT	Freeze Watch	PHI	Hunterdon, Morris, Somerset, Sussex, Warren	7 hr
Apr 21, 3:26 AM EDT	Freeze Warning	PHI	Hunterdon, Morris, Somerset, Sussex, Warren	30 hr
Apr 21, 12:25 PM EDT	Severe Thunderstorm Warning	PHI	Warren	50 min
Apr 21, 12:55 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	27 min
Apr 21, 1:10 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Mercer, Salem	50 min
Apr 21, 1:17 PM EDT	Special Weather Statement	PHI	Hunterdon, Morris, Somerset, Sussex	58 min
Apr 21, 1:28 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester	36 min
Apr 21, 1:30 PM EDT	Special Marine Warning	PHI		60 min
Apr 21, 1:43 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Morris, Somerset	33 min
Apr 21, 1:58 PM EDT	Special Weather Statement	PHI	Burlington, Camden, Monmouth, Ocean	62 min
Apr 21, 2:02 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Monmouth, Ocean	43 min
Apr 21, 2:03 PM EDT	Special Weather Statement	PHI	Cumberland	27 min
Apr 21, 2:17 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Cumberland, Gloucester, Salem	43 min
Apr 21, 2:28 PM EDT	Special Weather Statement	PHI	Middlesex, Monmouth	47 min
Apr 21, 2:30 PM EDT	Special Marine Warning	PHI		60 min
Apr 21, 2:38 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth, Ocean	37 min
Apr 21, 2:40 PM EDT	Special Marine Warning	PHI		55 min
Apr 21, 2:43 PM EDT	Special Weather Statement	PHI	Cape May	32 min
Apr 21, 2:50 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Ocean	40 min
Apr 21, 3:02 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic	28 min
Apr 21, 3:07 PM EDT	Special Marine Warning	PHI		53 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2021 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.