Alert archive / New Jersey / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 219, NWS Philadelphia/Mount Holly

September 6, 20254 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 6, 2025, 2:14 PM EDT for 4 counties in New Jersey. It was in force for 46 min. 8 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
Sep 6, 2025, 2:14 PM EDT (18:14 UTC)
Expired
Sep 6, 2025, 3:00 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

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

The radar

The Philadelphia radar (KDIX), 58 km from the middle of the area, began a volume at 18:16 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
Sep 6, 2:21 PM EDTTSTM WND DMGEast Amwell Twp, NJTrees and wires down. Time estimated from radar.
Sep 6, 2:34 PM EDTTSTM WND DMGHillsborough Twp, NJTrees and wires down. Time estimated from radar.
Sep 6, 2:34 PM EDTTSTM WND DMGMontgomery Twp, NJNumerous trees and wires down. Time estimated from radar.
Sep 6, 2:40 PM EDTHAIL 0.88Hillsborough Twp, NJNickel size hail in Hillsborough.
Sep 6, 2:44 PM EDTTSTM WND DMG1 Ese Millstone, NJSeveral trees down at Amwell Rd and Elizabeth Ave. Time estimated from radar.
Sep 6, 2:46 PM EDTTSTM WND DMG1 Ese Hillsborough Twp, NJDelayed report. Part of a barn roof peeled off and large branches down. Time from report.
Sep 6, 2:46 PM EDTTSTM WND DMGFranklin Township, NJTree down blocking road at South Middlebash Rd near Blackwells Mills Rd. Time estimated from radar.
Sep 6, 2:52 PM EDTTSTM WND DMGNorth Brunswick Twp, NJLarge tree fell, knocking down power poles. Picture relayed on social media. 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.

IssuedProductOfficeLasted
Sep 6, 1:13 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 6.2 hours before the alert went out and 167 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 2025-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 975 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 2025-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 74 square meters per square second.193958Sfc1 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
975 J/kg
Mixed-layer CIN
-68 J/kg
Mixed-layer LCL
816 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
74 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.5

Open this sounding in Storm Lab

The text

As transmitted.

691 
WUUS51 KPHI 061814
SVRPHI
NJC019-021-023-035-061900-
/O.NEW.KPHI.SV.W.0219.250906T1814Z-250906T1900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
214 PM EDT Sat Sep 6 2025

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Hunterdon County in northwestern New Jersey...
  Northwestern Mercer County in central New Jersey...
  Southern Somerset County in northern New Jersey...
  Northwestern Middlesex County in northern New Jersey...

* Until 300 PM EDT.

* At 214 PM EDT, a severe thunderstorm was located over Stockton, or
  16 miles northwest of Trenton, moving east at 35 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  New Brunswick, Somerville, Somerset, Old Bridge, East Brunswick,
  South Brunswick, North Brunswick, Middlesex, Princeton, Bound
  Brook, Manville, Jamesburg, Flemington, Pennington, Hopewell, Rocky
  Hill, Millstone, Skillman, Flagtown, and Kingston.

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.

&&

LAT...LON 4030 7488 4032 7491 4047 7500 4062 7448
      4037 7433
TIME...MOT...LOC 1814Z 259DEG 31KT 4039 7499 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

PO
1 follow-up statement
076 
WWUS51 KPHI 061835
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
235 PM EDT Sat Sep 6 2025

NJC019-021-061844-
/O.CAN.KPHI.SV.W.0219.000000T0000Z-250906T1900Z/
Hunterdon NJ-Mercer NJ-
235 PM EDT Sat Sep 6 2025

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HUNTERDON AND
NORTHWESTERN MERCER COUNTIES 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 800 PM EDT for
central, northern and northwestern New Jersey.

LAT...LON 4033 7463 4038 7462 4039 7467 4038 7472
      4051 7478 4054 7475 4062 7448 4037 7433
TIME...MOT...LOC 1834Z 259DEG 31KT 4042 7476 

$$

NJC023-035-061900-
/O.CON.KPHI.SV.W.0219.000000T0000Z-250906T1900Z/
Somerset NJ-Middlesex NJ-
235 PM EDT Sat Sep 6 2025

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR SOUTHERN SOMERSET AND NORTHWESTERN MIDDLESEX COUNTIES...

At 234 PM EDT, a severe thunderstorm was located over Hopewell, or 12
miles southwest of Somerville, moving east at 35 mph.

HAZARD...60 mph wind gusts and nickel size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
New Brunswick, Somerville, Somerset, Old Bridge, East Brunswick,
South Brunswick, North Brunswick, Middlesex, Bound Brook, Manville,
Jamesburg, Rocky Hill, Millstone, Skillman, Flagtown, Kingston,
Dayton, Belle Mead, North Brunswick Township, and Kendall Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm. Move
indoors immediately. Lightning is one of nature's leading killers.
Remember, if you can hear thunder, you are close enough to be struck
by lightning.

&&

LAT...LON 4033 7463 4038 7462 4039 7467 4038 7472
      4051 7478 4054 7475 4062 7448 4037 7433
TIME...MOT...LOC 1834Z 259DEG 31KT 4042 7476 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

PO

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 2:22 AM EDTSmall Craft AdvisoryPHI19 hr
Sep 6, 2:46 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Somerset23 min
Sep 6, 2:47 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Gloucester43 min
Sep 6, 2:52 PM EDTSpecial Marine WarningPHI23 min
Sep 6, 3:34 PM EDTSpecial Marine WarningPHI56 min
Sep 6, 3:38 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean38 min
Sep 6, 4:23 PM EDTSpecial Marine WarningPHI24 min
Sep 6, 4:57 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden31 min
Sep 6, 5:20 PM EDTSpecial Marine WarningPHI25 min
Sep 6, 5:51 PM EDTSpecial Marine WarningPHI54 min
Sep 6, 6:07 PM EDTSpecial Marine WarningPHI38 min
Sep 6, 6:20 PM EDTFlash Flood WarningPHIMonmouth4 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2025Every severe thunderstorm warning in 2025

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.