Alert archive / New Jersey / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 175, NWS Philadelphia/Mount Holly

July 23, 2020Mercer County, Middlesex County, Monmouth County, New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 23, 2020, 7:00 PM EDT for Mercer County, Middlesex County, Monmouth County, New Jersey; Bucks County, Pennsylvania. It was in force for 30 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: Jul 23, 2020, 7:00 PM EDT (23:00 UTC)
Expired: Jul 23, 2020, 7:30 PM EDT
In force: 30 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 42 km from the middle of the area, began a volume at 23:03 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 23, 7:40 PM EDT	TSTM WND DMG	1 Ese Perrineville, NJ	SEVERAL REPORTS OF WIRES DOWN IN THE AREA OF SWEETMANS LANE AND MILLSTONE ROAD. 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.

Issued	Product	Office	Lasted
Jul 23, 2:49 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 11.0 hours before the alert went out and 164 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: 579 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 990 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 37 m²/s²
0-3 km storm-relative helicity: 66 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

590 
WUUS51 KPHI 232300
SVRPHI
NJC021-023-025-PAC017-232330-
/O.NEW.KPHI.SV.W.0175.200723T2300Z-200723T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
700 PM EDT Thu Jul 23 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Mercer County in central New Jersey...
  West central Monmouth County in central New Jersey...
  Southwestern Middlesex County in northern New Jersey...
  Southeastern Bucks County in southeastern Pennsylvania...

* Until 730 PM EDT.

* At 700 PM EDT, a severe thunderstorm was located over Trenton,
  moving east at 20 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible.

* Locations impacted include...
  Trenton, South Brunswick, Ewing, Princeton, Hightstown, Cranbury,
  Pennington, Roosevelt, Windsor, Princeton Meadows, Kingston,
  Dayton, Plainsboro Center, Clearbrook Park, Edinburg, White Horse,
  Twin Rivers, Kendall Park, Mercerville-Hamilton Square and
  Lawrenceville.

This includes the following highways...
 New Jersey Turnpike between exits 8 and 8A.
 Interstate 195 in New Jersey near mile marker 0, and between mile
markers 2 and 8.
 Interstate 295 in New Jersey between mile markers 60 and 75.

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.

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 4018 7469 4019 7470 4018 7471 4017 7480
      4030 7484 4039 7463 4037 7461 4040 7459
      4041 7458 4043 7454 4020 7439
TIME...MOT...LOC 2300Z 252DEG 19KT 4025 7475 

HAIL...1.00IN
WIND...<50MPH
 
$$

Robertson

2 follow-up statements

832 
WWUS51 KPHI 232305
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
705 PM EDT Thu Jul 23 2020

NJC021-023-025-PAC017-232330-
/O.CON.KPHI.SV.W.0175.000000T0000Z-200723T2330Z/
Mercer NJ-Monmouth NJ-Middlesex NJ-Bucks PA-
705 PM EDT Thu Jul 23 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR MERCER...WEST CENTRAL MONMOUTH...SOUTHWESTERN MIDDLESEX AND
SOUTHEASTERN BUCKS COUNTIES...

At 704 PM EDT, a severe thunderstorm was located over
Mercerville-Hamilton Square, or near Trenton, moving east at 20 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...
Trenton, South Brunswick, Ewing, Princeton, Hightstown, Cranbury,
Pennington, Roosevelt, Windsor, Princeton Meadows, Kingston, Dayton,
Plainsboro Center, Clearbrook Park, Edinburg, White Horse, Twin
Rivers, Kendall Park, Mercerville-Hamilton Square and Lawrenceville.

This includes the following highways...
 New Jersey Turnpike between exits 8 and 8A.
 Interstate 195 in New Jersey near mile marker 0, and between mile
markers 2 and 8.
 Interstate 295 in New Jersey between mile markers 60 and 75.

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 4018 7469 4019 7470 4018 7471 4017 7480
      4030 7484 4039 7463 4037 7461 4040 7459
      4041 7458 4043 7454 4020 7439
TIME...MOT...LOC 2304Z 252DEG 19KT 4026 7471 

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

Robertson

316 
WWUS51 KPHI 232318
SVSPHI

.Severe Weather Statement
National Weather Service Mount Holly NJ
718 PM EDT Thu Jul 23 2020

PAC017-232327-
/O.CAN.KPHI.SV.W.0175.000000T0000Z-200723T2330Z/
Bucks PA-
718 PM EDT Thu Jul 23 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BUCKS 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 1000 PM EDT for
northern New Jersey.

Additional showers and thunderstorms remain possible tonight.

LAT...LON 4021 7468 4031 7471 4040 7452 4023 7441
TIME...MOT...LOC 2317Z 252DEG 19KT 4028 7462 

$$

NJC021-023-025-232330-
/O.CON.KPHI.SV.W.0175.000000T0000Z-200723T2330Z/
Mercer NJ-Monmouth NJ-Middlesex NJ-
718 PM EDT Thu Jul 23 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR EAST CENTRAL MERCER...WESTERN MONMOUTH AND SOUTHWESTERN MIDDLESEX
COUNTIES...

At 717 PM EDT, a severe thunderstorm was located over Edinburg, or 8
miles northeast of Trenton, moving east at 20 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...
Hightstown, Cranbury, Roosevelt, Edinburg, Windsor, Princeton
Meadows, Twin Rivers, Dayton, Mercerville-Hamilton Square, Plainsboro
Center, Clearbrook Park, Princeton Junction, Monmouth Junction,
Rossmoor and Heathcote.

This includes the following highways...
 New Jersey Turnpike near exit 8A.
 Interstate 295 in New Jersey between mile markers 66 and 67.

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 4021 7468 4031 7471 4040 7452 4023 7441
TIME...MOT...LOC 2317Z 252DEG 19KT 4028 7462 

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

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 8:53 PM EDT	Special Marine Warning	PHI		52 min
Jul 23, 9:32 AM EDT	Special Weather Statement	PHI	Mercer	28 min
Jul 23, 5:08 PM EDT	Special Weather Statement	PHI	Warren	37 min
Jul 23, 5:14 PM EDT	Special Weather Statement	PHI	Hunterdon	31 min
Jul 23, 5:23 PM EDT	Special Weather Statement	PHI	Sussex	22 min
Jul 23, 5:48 PM EDT	Special Weather Statement	PHI	Sussex	57 min
Jul 23, 6:11 PM EDT	Special Weather Statement	PHI	Somerset	34 min
Jul 23, 6:13 PM EDT	Special Weather Statement	PHI	Hunterdon	32 min
Jul 23, 6:30 PM EDT	Special Weather Statement	PHI	Mercer	30 min
Jul 23, 6:53 PM EDT	Special Weather Statement	PHI	Mercer	37 min
Jul 23, 7:10 PM EDT	Special Weather Statement	PHI	Middlesex	35 min
Jul 23, 7:29 PM EDT	Special Weather Statement	PHI	Monmouth	31 min
Jul 23, 7:52 PM EDT	Special Weather Statement	PHI	Monmouth	38 min
Jul 23, 7:56 PM EDT	Special Marine Warning	PHI		64 min
Jul 23, 12:58 PM EDT	Special Weather Statement	PHI	Northampton	32 min
Jul 23, 2:43 PM EDT	Areal Flood Advisory	PHI	Carbon, Monroe, Northampton	4 hr
Jul 23, 3:03 PM EDT	Special Weather Statement	PHI	Northampton	27 min
Jul 23, 4:26 PM EDT	Special Weather Statement	PHI	Lehigh	34 min
Jul 23, 7:41 PM EDT	Special Weather Statement	PHI	Montgomery	34 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2020 Severe Thunderstorm Warnings in Pennsylvania, 2020 Every severe thunderstorm warning in 2020

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.