Alert archive / New Jersey / Tornado Warnings in 2021

Tornado Warning 12, NWS Philadelphia/Mount Holly

July 17, 2021Middlesex County, New Jersey

NWS Philadelphia/Mount Holly issued this tornado warning at Jul 17, 2021, 3:09 PM EDT for Middlesex 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: Jul 17, 2021, 3:09 PM EDT (19:09 UTC)
Expired: Jul 17, 2021, 3:30 PM EDT
In force: 21 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Middlesex County, NJ

The radar

The Philadelphia radar (KDIX), 71 km from the middle of the area, began a volume at 19:09 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
Jul 17, 1:13 PM EDT	Severe Thunderstorm Watch	SPC	10 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 7.2 hours before the alert went out and 121 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: 1203 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 1054 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted.

029 
WFUS51 KPHI 171909
TORPHI
NJC023-171930-
/O.NEW.KPHI.TO.W.0012.210717T1909Z-210717T1930Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
309 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  Northeastern Middlesex County in northern New Jersey...

* Until 330 PM EDT.
    
* At 309 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Carteret, or near Linden, moving east at 55 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* Locations impacted include...
  Carteret, Colonia, Woodbridge, Sewaren, Port Reading, Avenel,
  Iselin and Fords.

This includes New Jersey Turnpike near exit 13.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4056 7421 4054 7425 4054 7430 4060 7432
      4060 7431 4059 7428 4060 7426 4060 7421
      4059 7420
TIME...MOT...LOC 1909Z 255DEG 49KT 4058 7426 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Davis

1 follow-up statement

567 
WWUS51 KPHI 171922
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
322 PM EDT Sat Jul 17 2021

NJC023-171931-
/O.EXP.KPHI.TO.W.0012.000000T0000Z-210717T1930Z/
Middlesex NJ-
322 PM EDT Sat Jul 17 2021

...THE TORNADO WARNING FOR NORTHEASTERN MIDDLESEX COUNTY WILL EXPIRE
AT 330 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
northern New Jersey.

Remember, a Severe Thunderstorm Warning still remains in effect for
eastern Middlesex County. 

LAT...LON 4056 7421 4054 7425 4054 7430 4060 7432
      4060 7431 4059 7428 4060 7426 4060 7421
      4059 7420
TIME...MOT...LOC 1921Z 255DEG 49KT 4061 7410 

$$

Davis

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 12:55 PM EDT	Special Weather Statement	PHI	Hunterdon	50 min
Jul 17, 1:05 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer	40 min
Jul 17, 1:31 PM EDT	Areal Flood Advisory	PHI	Hunterdon	97 min
Jul 17, 1:50 PM EDT	Special Marine Warning	PHI		40 min
Jul 17, 1:56 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Somerset, Warren	36 min
Jul 17, 2:02 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	92 min
Jul 17, 2:56 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Somerset	49 min
Jul 17, 3:06 PM EDT	Severe Thunderstorm Warning	PHI	Warren	39 min
Jul 17, 3:38 PM EDT	Areal Flood Advisory	PHI	Middlesex	40 min
Jul 17, 3:51 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex	24 min
Jul 17, 4:55 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Somerset	50 min
Jul 17, 5:13 PM EDT	Areal Flood Advisory	PHI	Hunterdon	4 hr
Jul 17, 5:19 PM EDT	Tornado Warning	PHI	Hunterdon	14 min
Jul 17, 5:25 PM EDT	Flash Flood Warning	PHI	Hunterdon	6 hr
Jul 17, 5:30 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	19 min
Jul 17, 5:52 PM EDT	Areal Flood Advisory	PHI	Somerset	2 hr
Jul 17, 6:02 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Somerset	43 min
Jul 17, 6:15 PM EDT	Flash Flood Warning	PHI	Morris, Somerset	5 hr
Jul 17, 6:39 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	51 min
Jul 17, 6:51 PM EDT	Severe Thunderstorm Warning	PHI	Burlington	39 min
Jul 17, 6:59 PM EDT	Small Craft Advisory	PHI		7 hr
Jul 17, 7:01 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Somerset	44 min
Jul 17, 7:12 PM EDT	Areal Flood Advisory	PHI	Mercer, Somerset	3 hr
Jul 17, 7:26 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	49 min

Nearby

Tornado Warnings in New Jersey, 2021 Every tornado warning in 2021 Tornadoes 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.