Alert archive / New Jersey / Tornado Warnings in 2023

Tornado Warning 33, NWS Philadelphia/Mount Holly

August 13, 2023Hunterdon County, Middlesex County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 13, 2023, 1:25 AM EDT for Hunterdon County, Middlesex County, Somerset County, New Jersey. It was in force for 35 min. 2 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
Aug 13, 2023, 1:25 AM EDT (05:25 UTC)
Expired
Aug 13, 2023, 2:00 AM EDT
In force
35 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Hunterdon County, NJ, Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 69 km from the middle of the area, began a volume at 05:26 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
Aug 13, 1:41 AM EDTTSTM WND DMG2 S Raritan, NJTrees down on Roycefield Road in Hillsborough Township. Time estimated from radar.
Aug 13, 1:45 AM EDTTSTM WND DMGBridgewater, NJTrees down. Photos received via social media. Time estimated from radar.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 5.4 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-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2023-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 358 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 2023-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 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
358 J/kg
Mixed-layer CIN
-89 J/kg
Mixed-layer LCL
1179 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
113 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

764 
WFUS51 KPHI 130525
TORPHI
NJC019-023-035-130600-
/O.NEW.KPHI.TO.W.0033.230813T0525Z-230813T0600Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
125 AM EDT Sun Aug 13 2023

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  East central Hunterdon County in northwestern New Jersey...
  Central Somerset County in northern New Jersey...
  Northwestern Middlesex County in northern New Jersey...

* Until 200 AM EDT.
    
* At 125 AM EDT, a severe thunderstorm capable of producing a tornado
  was located over Flemington, or 14 miles west of Somerville, moving
  east at 45 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...
  New Brunswick, Somerville, Somerset, East Brunswick, Bridgewater,
  North Brunswick, Middlesex, Bound Brook, Manville, Flemington,
  Millstone, Flagtown, Cloverhill, Belle Mead, Martinsville, North
  Brunswick Township, Sand Brook, Kendall Park, Raritan and South
  Bound Brook.

This includes Interstate 287 in New Jersey between mile markers 10
and 19.
 
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 4047 7493 4054 7494 4064 7452 4042 7446
TIME...MOT...LOC 0525Z 263DEG 39KT 4051 7487 

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

$$

RCM
3 follow-up statements
918 
WWUS51 KPHI 130536
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
136 AM EDT Sun Aug 13 2023

NJC019-023-035-130600-
/O.CON.KPHI.TO.W.0033.000000T0000Z-230813T0600Z/
Hunterdon NJ-Somerset NJ-Middlesex NJ-
136 AM EDT Sun Aug 13 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 200 AM EDT FOR EAST
CENTRAL HUNTERDON...CENTRAL SOMERSET AND NORTH CENTRAL MIDDLESEX
COUNTIES...
    
At 136 AM EDT, a severe thunderstorm capable of producing a tornado
was located near Flagtown, or 7 miles west of Somerville, moving east
at 35 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...
Somerville, Somerset, Bridgewater, Middlesex, Bound Brook, Manville,
Martinsville, Flagtown, Raritan and South Bound Brook.

This includes Interstate 287 in New Jersey between mile markers 9 and
19.
 
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 4052 7478 4057 7481 4058 7479 4064 7452
      4051 7448
TIME...MOT...LOC 0536Z 248DEG 31KT 4055 7476 

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

$$

RCM
474 
WWUS51 KPHI 130546
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
146 AM EDT Sun Aug 13 2023

NJC019-130555-
/O.CAN.KPHI.TO.W.0033.000000T0000Z-230813T0600Z/
Hunterdon NJ-
146 AM EDT Sun Aug 13 2023

...THE TORNADO WARNING FOR EAST CENTRAL HUNTERDON COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

LAT...LON 4053 7466 4058 7469 4060 7468 4064 7452
      4051 7448
TIME...MOT...LOC 0545Z 262DEG 37KT 4056 7463 

$$

NJC023-035-130600-
/O.CON.KPHI.TO.W.0033.000000T0000Z-230813T0600Z/
Somerset NJ-Middlesex NJ-
146 AM EDT Sun Aug 13 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 200 AM EDT FOR CENTRAL
SOMERSET AND NORTH CENTRAL MIDDLESEX COUNTIES...
    
At 145 AM EDT, a severe thunderstorm capable of producing a tornado
was located over Somerville, moving east at 40 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...
Somerville, Somerset, Bridgewater, Middlesex, Bound Brook, Manville,
Martinsville, Raritan and South Bound Brook.

This includes Interstate 287 in New Jersey between mile markers 9 and
18.
 
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 4053 7466 4058 7469 4060 7468 4064 7452
      4051 7448
TIME...MOT...LOC 0545Z 262DEG 37KT 4056 7463 

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

$$

RCM
566 
WWUS51 KPHI 130552
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
152 AM EDT Sun Aug 13 2023

NJC023-130601-
/O.CAN.KPHI.TO.W.0033.000000T0000Z-230813T0600Z/
Middlesex NJ-
152 AM EDT Sun Aug 13 2023

...THE TORNADO WARNING FOR NORTH CENTRAL MIDDLESEX COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved past 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4061 7455 4060 7463 4061 7465 4064 7452
      4062 7451
TIME...MOT...LOC 0551Z 227DEG 33KT 4063 7460 

$$

NJC035-130600-
/O.CON.KPHI.TO.W.0033.000000T0000Z-230813T0600Z/
Somerset NJ-
152 AM EDT Sun Aug 13 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 200 AM EDT FOR CENTRAL
SOMERSET COUNTY...
    
At 151 AM EDT, a severe thunderstorm capable of producing a tornado
was located over Martinsville, or near Somerville, moving northeast
at 40 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.

This tornadic thunderstorm will remain over mainly rural areas of
central Somerset County.

This includes Interstate 287 in New Jersey near mile marker 19.
 
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 4061 7455 4060 7463 4061 7465 4064 7452
      4062 7451
TIME...MOT...LOC 0551Z 227DEG 33KT 4063 7460 

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

$$

RCM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 9:22 PM EDTSpecial Weather StatementPHISussex53 min
Aug 13, 1:10 AM EDTSevere Thunderstorm WarningPHIBurlington, Hunterdon, Mercer, Middlesex, Monmouth, Somerset50 min
Aug 13, 1:41 AM EDTSevere Thunderstorm Warning Considerable damage threatPHIHunterdon, Middlesex, Morris, Somerset33 min
Aug 13, 1:49 AM EDTTornado WarningPHIMorris, Somerset26 min

Nearby

Tornado Warnings in New Jersey, 2023Every tornado warning in 2023Tornadoes in 2023

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.