Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 301, NWS Philadelphia/Mount Holly

September 13, 20214 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 13, 2021, 9:03 PM EDT for 4 counties in New Jersey. It was in force for 57 min. 1 report 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
Sep 13, 2021, 9:03 PM EDT (01:03 UTC)
Expired
Sep 13, 2021, 10:00 PM EDT
In force
57 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Hunterdon County, NJ, Morris County, NJ, Somerset County, NJ, Warren County, NJ

The radar

The Philadelphia radar (KDIX), 99 km from the middle of the area, began a volume at 01:07 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
Sep 13, 9:47 PM EDTTSTM WND DMG1 N Budd Lake, NJDOWNED POLE AND DOWNED WIRES ON US 46 EASTBOUND AREA OF CR 667/MT. OLIVE RD (MOUNT OLIVE TWP). ALL LANES CLOSED.

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
Sep 13, 7:44 PM EDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 1.1 hours before the alert went out and 138 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, Brookhaven, NY at 00:00Z on 2021-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 90 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, Brookhaven, NY at 00:00Z on 2021-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 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
90 J/kg
Mixed-layer CIN
-236 J/kg
Mixed-layer LCL
1411 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

782 
WUUS51 KPHI 140103
SVRPHI
NJC019-027-035-041-140200-
/O.NEW.KPHI.SV.W.0301.210914T0103Z-210914T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
903 PM EDT Mon Sep 13 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northeastern Hunterdon County in northwestern New Jersey...
  Morris County in northern New Jersey...
  East central Warren County in northwestern New Jersey...
  Northwestern Somerset County in northern New Jersey...

* Until 1000 PM EDT.

* At 903 PM EDT, a severe thunderstorm was located over Long Valley,
  or 14 miles west of Morristown, moving east 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...
  Morristown, Dover, Madison, Hopatcong, Florham Park, East Hanover,
  Hackettstown, Chatham, Boonton, Wharton, Rockaway, Morris Plains,
  Mount Arlington, Mendham, Mountain Lakes, High Bridge, Stanhope,
  Netcong, Peapack And Gladstone and Glen Gardner.

This includes the following highways...
 Interstate 80 in New Jersey near mile marker 20, and between mile
markers 22 and 48.
 Interstate 287 in New Jersey between mile markers 25 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 4089 7434 4088 7434 4086 7432 4079 7437
      4076 7438 4075 7436 4067 7446 4068 7500
      4092 7481 4092 7473 4090 7471 4092 7466
      4090 7427
TIME...MOT...LOC 0103Z 271DEG 31KT 4080 7475 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Gorse
3 follow-up statements
922 
WWUS51 KPHI 140131
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
931 PM EDT Mon Sep 13 2021

NJC041-140141-
/O.CAN.KPHI.SV.W.0301.000000T0000Z-210914T0200Z/
Warren NJ-
931 PM EDT Mon Sep 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL WARREN COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 100 AM EDT for
northern and northwestern New Jersey.

LAT...LON 4089 7434 4088 7434 4086 7432 4079 7437
      4076 7438 4075 7436 4067 7446 4068 7500
      4092 7466 4090 7427
TIME...MOT...LOC 0131Z 280DEG 34KT 4074 7443 

$$

NJC019-027-035-140200-
/O.CON.KPHI.SV.W.0301.000000T0000Z-210914T0200Z/
Hunterdon NJ-Morris NJ-Somerset NJ-
931 PM EDT Mon Sep 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT
FOR NORTHEASTERN HUNTERDON...MORRIS AND NORTHWESTERN SOMERSET
COUNTIES...

At 931 PM EDT, a severe thunderstorm was located over Madison, or
near Summit, moving east at 40 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...
Morristown, Dover, Madison, Florham Park, East Hanover, Chatham,
Boonton, Wharton, Rockaway, Morris Plains, Mount Arlington, Mendham,
Mountain Lakes, High Bridge, Netcong, Peapack And Gladstone, Glen
Gardner, Chester, Victory Gardens and Hampton.

This includes the following highways...
 Interstate 80 in New Jersey between mile markers 27 and 48.
 Interstate 287 in New Jersey between mile markers 25 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 4089 7434 4088 7434 4086 7432 4079 7437
      4076 7438 4075 7436 4067 7446 4068 7500
      4092 7466 4090 7427
TIME...MOT...LOC 0131Z 280DEG 34KT 4074 7443 

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

$$

Gorse
087 
WWUS51 KPHI 140140
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
940 PM EDT Mon Sep 13 2021

NJC019-027-035-140200-
/O.CON.KPHI.SV.W.0301.000000T0000Z-210914T0200Z/
Hunterdon NJ-Morris NJ-Somerset NJ-
940 PM EDT Mon Sep 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT
FOR EASTERN HUNTERDON...SOUTHEASTERN MORRIS AND NORTHWESTERN SOMERSET
COUNTIES...

At 940 PM EDT, a severe thunderstorm was located over Millburn,
moving east at 50 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...
Morristown, Madison, Florham Park, East Hanover, Chatham, Boonton,
Morris Plains, Mendham, Mountain Lakes, Peapack And Gladstone, Far
Hills, Parsippany, Millington, Basking Ridge, Bernardsville and
Hanover Township.

This includes the following highways...
 Interstate 80 in New Jersey between mile markers 40 and 48.
 Interstate 287 in New Jersey between mile markers 25 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 4089 7434 4088 7434 4086 7432 4079 7437
      4076 7438 4075 7436 4067 7446 4068 7481
      4091 7445 4090 7427
TIME...MOT...LOC 0140Z 272DEG 43KT 4074 7430 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Gorse
683 
WWUS51 KPHI 140151
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
951 PM EDT Mon Sep 13 2021

NJC019-027-035-140200-
/O.EXP.KPHI.SV.W.0301.000000T0000Z-210914T0200Z/
Hunterdon NJ-Morris NJ-Somerset NJ-
951 PM EDT Mon Sep 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN HUNTERDON...
SOUTHEASTERN MORRIS AND NORTHWESTERN SOMERSET COUNTIES WILL EXPIRE AT
1000 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 100 AM EDT for
northern New Jersey.

LAT...LON 4089 7434 4088 7434 4086 7432 4079 7437
      4076 7438 4075 7436 4067 7446 4068 7481
      4091 7445 4090 7427
TIME...MOT...LOC 0150Z 271DEG 31KT 4074 7419 

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 13, 8:41 PM EDTSevere Thunderstorm WarningPHIHunterdon, Warren49 min
Sep 13, 9:03 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Somerset, Sussex, Warren109 min
Sep 13, 9:12 PM EDTFlash Flood WarningPHIHunterdon, Morris, Warren114 min
Sep 13, 9:21 PM EDTSevere Thunderstorm WarningPHIHunterdon, Somerset, Warren38 min
Sep 13, 9:34 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Morris, Somerset38 min
Sep 13, 9:53 PM EDTSevere Thunderstorm WarningPHIMercer, Middlesex, Monmouth, Somerset52 min
Sep 13, 10:03 PM EDTSpecial Marine WarningPHI57 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.