Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 182, NWS Philadelphia/Mount Holly

July 17, 2021Middlesex County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2021, 2:56 PM EDT for Middlesex County, Somerset County, New Jersey. It was in force for 49 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 17, 2021, 2:56 PM EDT (18:56 UTC)
Expired: Jul 17, 2021, 3:45 PM EDT
In force: 49 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 18:56 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

Time	Report	Where	Remark
Jul 17, 3:07 PM EDT	FUNNEL CLOUD	Woodbridge, NJ	SPOTTER REPORTED A FUNNEL CLOUD AT 3:07 PM. FROM HIS VANTAGE POINT, IT DID NOT APPEAR TO MAKE CONTACT WITH THE GROUND.
Jul 17, 3:31 PM EDT	HAIL 0.88	Hopelawn, NJ
Jul 17, 3:37 PM EDT	MARINE TSTM WIND 54	2 Sw Tottenville, NY
Jul 17, 3:37 PM EDT	TSTM WND GST 54	Hopelawn, NJ

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.

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, 6.9 hours before the alert went out and 127 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.

192 
WUUS51 KPHI 171856
SVRPHI
NJC023-035-171945-
/O.NEW.KPHI.SV.W.0182.210717T1856Z-210717T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
256 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  East central Somerset County in northern New Jersey...
  Northeastern Middlesex County in northern New Jersey...

* Until 345 PM EDT.

* At 256 PM EDT, a severe thunderstorm was located over Society Hill,
  or over New Brunswick, moving east at 25 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...
  New Brunswick, Perth Amboy, Somerset, Edison, East Brunswick,
  Sayreville, Carteret, Middlesex, Bound Brook, Colonia, Society
  Hill, North Brunswick Township, Woodbridge, South Plainfield,
  Highland Park, Metuchen, Dunellen, South Bound Brook, Iselin and
  Sewaren.

This includes the following highways...
 New Jersey Turnpike between exits 10 and 13.
 Interstate 287 in New Jersey between mile markers 0 and 12.
 Garden State Parkway between mile markers 123 and 134.

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.

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

&&

LAT...LON 4055 7425 4050 7426 4050 7428 4046 7426
      4045 7423 4048 7457 4060 7453 4060 7441
      4061 7434 4059 7428 4060 7421 4056 7421
TIME...MOT...LOC 1856Z 256DEG 20KT 4052 7445 

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

Davis

1 follow-up statement

445 
WWUS51 KPHI 171916
SVSPHI

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

NJC035-171925-
/O.CAN.KPHI.SV.W.0182.000000T0000Z-210717T1945Z/
Somerset NJ-
316 PM EDT Sat Jul 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL SOMERSET 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 1100 PM EDT for
northern New Jersey.

LAT...LON 4055 7425 4050 7426 4050 7428 4046 7426
      4045 7423 4047 7442 4060 7439 4061 7434
      4059 7428 4060 7421 4056 7421
TIME...MOT...LOC 1915Z 256DEG 20KT 4055 7431 

$$

NJC023-171945-
/O.CON.KPHI.SV.W.0182.000000T0000Z-210717T1945Z/
Middlesex NJ-
316 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR NORTHEASTERN MIDDLESEX COUNTY...

At 315 PM EDT, a severe thunderstorm was located over Perth Amboy,
moving east at 25 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...
New Brunswick, Perth Amboy, Edison, East Brunswick, Sayreville,
Carteret, Colonia, Woodbridge, Highland Park, Metuchen, Iselin,
Sewaren, Port Reading, Fords and Avenel.

This includes the following highways...
 New Jersey Turnpike between exits 10 and 13.
 Interstate 287 in New Jersey between mile markers 0 and 3.
 Garden State Parkway between mile markers 123 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4055 7425 4050 7426 4050 7428 4046 7426
      4045 7423 4047 7442 4060 7439 4061 7434
      4059 7428 4060 7421 4056 7421
TIME...MOT...LOC 1915Z 256DEG 20KT 4055 7431 

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

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, 3:06 PM EDT	Severe Thunderstorm Warning	PHI	Warren	39 min
Jul 17, 3:09 PM EDT	Tornado Warning	PHI	Middlesex	21 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

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.