Alert archive / New Jersey / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 307, NWS Philadelphia/Mount Holly

November 30, 2020Mercer County, Middlesex County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Nov 30, 2020, 5:29 PM EST for Mercer County, Middlesex County, Somerset County, New Jersey. It was in force for 46 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
Nov 30, 2020, 5:29 PM EST (22:29 UTC)
Expired
Nov 30, 2020, 6:15 PM EST
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Mercer County, NJ, Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 22:30 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.

IssuedProductOfficeLasted
Nov 30, 1:07 PM ESTTornado WatchSPC6 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.5 hours before the alert went out and 149 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 12:00Z on 2020-11-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 12:00Z on 2020-11-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 306 square meters per square second.1939587897Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
958 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
306 m²/s²
0-3 km storm-relative helicity
408 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

882 
WUUS51 KPHI 302229
SVRPHI
NJC021-023-035-302315-
/O.NEW.KPHI.SV.W.0307.201130T2229Z-201130T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
529 PM EST Mon Nov 30 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Central Mercer County in central New Jersey...
  Somerset County in northern New Jersey...
  Northwestern Middlesex County in northern New Jersey...

* Until 615 PM EST.

* At 529 PM EST, a severe thunderstorm was located over
  Lawrenceville, or near Trenton, moving northeast at 50 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Trenton, New Brunswick, Somerville, Somerset, Edison, East
  Brunswick, Bridgewater, South Brunswick, North Brunswick, Ewing,
  Middlesex, Princeton, Bound Brook, Manville, Pennington, Hopewell,
  Far Hills, Rocky Hill, Millstone and Skillman.

This includes the following highways...
 New Jersey Turnpike between exits 10 and 11.
 Interstate 78 in New Jersey between mile markers 32 and 41.
 Interstate 295 in New Jersey between mile markers 63 and 73.
 Interstate 287 in New Jersey between mile markers 0 and 20, and
between mile markers 24 and 27.
 Garden State Parkway between mile markers 130 and 133.

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.

A Tornado Watch remains in effect until 700 PM EST for central,
northern and northwestern New Jersey.

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

&&

LAT...LON 4021 7471 4030 7483 4042 7476 4043 7475
      4072 7460 4069 7453 4065 7452 4067 7448
      4064 7441 4060 7446 4061 7435 4057 7427
TIME...MOT...LOC 2229Z 225DEG 44KT 4030 7470 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

JEO
2 follow-up statements
999 
WWUS51 KPHI 302246
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
546 PM EST Mon Nov 30 2020

NJC021-023-035-302315-
/O.CON.KPHI.SV.W.0307.000000T0000Z-201130T2315Z/
Mercer NJ-Somerset NJ-Middlesex NJ-
546 PM EST Mon Nov 30 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EST
FOR NORTHEASTERN MERCER...SOMERSET AND NORTHWESTERN MIDDLESEX
COUNTIES...

At 545 PM EST, a severe thunderstorm was located over Kendall Park, 
or 8 miles west of New Brunswick, moving northeast at 45 mph. A 
second potentially severe thunderstorm was located just southwest of 
Princeton and also moving northeast.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
New Brunswick, Somerville, Somerset, Edison, East Brunswick,
Bridgewater, South Brunswick, North Brunswick, Middlesex, Princeton,
Bound Brook, Manville, Pennington, Hopewell, Far Hills, Rocky Hill,
Millstone, Skillman, Flagtown and Colonia.

This includes the following highways...
 New Jersey Turnpike between exits 10 and 11.
 Interstate 78 in New Jersey between mile markers 32 and 41.
 Interstate 295 in New Jersey between mile markers 65 and 71.
 Interstate 287 in New Jersey between mile markers 0 and 20, and
between mile markers 24 and 27.
 Garden State Parkway between mile markers 130 and 133.

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.

A Tornado Watch remains in effect until 700 PM EST for central,
northern and northwestern New Jersey.

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

&&

LAT...LON 4023 7469 4031 7480 4042 7476 4043 7475
      4072 7460 4069 7453 4065 7452 4067 7448
      4064 7441 4060 7446 4061 7435 4057 7427
TIME...MOT...LOC 2245Z 219DEG 41KT 4044 7460 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

JEO
530 
WWUS51 KPHI 302309
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
609 PM EST Mon Nov 30 2020

NJC021-023-035-302319-
/O.EXP.KPHI.SV.W.0307.000000T0000Z-201130T2315Z/
Mercer NJ-Somerset NJ-Middlesex NJ-
609 PM EST Mon Nov 30 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MERCER...SOMERSET
AND NORTHWESTERN MIDDLESEX COUNTIES WILL EXPIRE AT 615 PM EST...
                
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 will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

A Tornado Watch remains in effect until 700 PM EST for central,
northern and northwestern New Jersey.

LAT...LON 4023 7469 4031 7480 4042 7476 4043 7475
      4072 7460 4069 7453 4065 7452 4067 7448
      4064 7441 4060 7446 4061 7435 4057 7427
TIME...MOT...LOC 2309Z 225DEG 44KT 4058 7444 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 30, 12:52 PM ESTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 5 more92 min
Nov 30, 1:28 PM ESTAreal Flood AdvisoryPHIHunterdon, Warren2 hr
Nov 30, 2:01 PM ESTCoastal Flood StatementPHIOcean3 hr
Nov 30, 2:01 PM ESTAreal Flood WarningPHIHunterdon, Mercer, Middlesex, Somerset9 hr
Nov 30, 2:18 PM ESTCoastal Flood AdvisoryPHIBurlington, Camden, Gloucester2 hr
Nov 30, 2:34 PM ESTSpecial Weather StatementPHIMorris, Sussex56 min
Nov 30, 2:48 PM ESTAreal Flood WarningPHIGloucester, Salem8 hr
Nov 30, 3:01 PM ESTSevere Thunderstorm WarningPHIGloucester, Salem44 min
Nov 30, 3:26 PM ESTAreal Flood WarningPHIHunterdon, Warren4 hr
Nov 30, 3:37 PM ESTSpecial Marine WarningPHI38 min
Nov 30, 3:43 PM ESTSevere Thunderstorm WarningPHIHunterdon, Warren47 min
Nov 30, 3:47 PM ESTTornado WarningPHICumberland, Salem28 min
Nov 30, 3:53 PM ESTAreal Flood WarningPHIHunterdon, Morris, Somerset, Sussex, Warren16 hr
Nov 30, 3:53 PM ESTTornado WarningPHIHunterdon13 min
Nov 30, 3:58 PM ESTSmall Craft AdvisoryPHI56 hr
Nov 30, 4:17 PM ESTAreal Flood WarningPHICamden, Hunterdon, Mercer, Middlesex10 hr
Nov 30, 4:49 PM ESTSevere Thunderstorm WarningPHICamden, Cumberland, Gloucester, Salem41 min
Nov 30, 5:05 PM ESTSpecial Marine WarningPHI40 min
Nov 30, 5:36 PM ESTRiver Flood WarningPHIHunterdon, Somerset7 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2020Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.