Alert archive / New Jersey / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 338, NWS Philadelphia/Mount Holly

September 8, 20235 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 8, 2023, 4:50 PM EDT for 5 counties in New Jersey. It was in force for 40 min. 7 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 8, 2023, 4:50 PM EDT (20:50 UTC)
Expired
Sep 8, 2023, 5:30 PM EDT
In force
40 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Hunterdon County, NJ, Morris County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ

The radar

The Philadelphia radar (KDIX), 84 km from the middle of the area, began a volume at 20:52 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 8, 5:01 PM EDTHAIL 0.75Long Valley, NJReport on social media of penny-sized hail.
Sep 8, 5:02 PM EDTHAIL 0.51 Nw Long Valley, NJReport from mPING: Half-inch (0.50 in.).
Sep 8, 5:05 PM EDTHAIL 1.25Long Valley, NJPhotos from trained spotter showed hail as large as half dollar size in Long Valley. Hail fell for 5 minutes.
Sep 8, 5:06 PM EDTTSTM WND DMG1 Se Hackettstown, NJDowned tree on US 46 westbound East of CR 604/NJ 182/Willow Grove St (Mount Olive Twp) All lanes closed. Time estimated from radar.
Sep 8, 5:07 PM EDTHAIL 11 Nw Long Valley, NJReport from mPING: Quarter (1.00 in.).
Sep 8, 5:20 PM EDTTSTM WND DMGByram Twp, NJReports of trees and power lines down in Byram Twp. Time estimated from radar.
Sep 8, 5:20 PM EDTTSTM WND DMGGreen Twp, NJReports of trees and power lines down in Green Twp. 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 8, 3:11 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.8 hours before the alert went out and 166 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 2023-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2469 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 2023-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 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
2469 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
566 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.0

Open this sounding in Storm Lab

The text

As transmitted.

436 
WUUS51 KPHI 082050
SVRPHI
NJC019-027-035-037-041-082130-
/O.NEW.KPHI.SV.W.0338.230908T2050Z-230908T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
450 PM EDT Fri Sep 8 2023

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Hunterdon County in northwestern New Jersey...
  Southwestern Morris County in northern New Jersey...
  South central Sussex County in northwestern New Jersey...
  Southeastern Warren County in northwestern New Jersey...
  Northwestern Somerset County in northern New Jersey...

* Until 530 PM EDT.

* At 450 PM EDT, a severe thunderstorm was located over Califon, or
  15 miles northwest of Somerville, moving northeast at 20 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...
  Morristown, Bridgewater, Dover, Hopatcong, Hackettstown, Wharton,
  Morris Plains, Mount Arlington, Mendham, Flemington, High Bridge,
  Stanhope, Netcong, Clinton, Peapack And Gladstone, Glen Gardner,
  Chester, Victory Gardens, Hampton and Lebanon.

This includes the following highways...
 Interstate 78 in New Jersey between mile markers 11 and 33.
 Interstate 80 in New Jersey between mile markers 18 and 32.
 Interstate 287 in New Jersey between mile markers 20 and 39.

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 4041 7487 4057 7508 4100 7481 4081 7441
TIME...MOT...LOC 2050Z 216DEG 19KT 4074 7481 

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

$$

MLB
2 follow-up statements
417 
WWUS51 KPHI 082103
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
503 PM EDT Fri Sep 8 2023

NJC019-027-035-037-041-082130-
/O.CON.KPHI.SV.W.0338.000000T0000Z-230908T2130Z/
Hunterdon NJ-Morris NJ-Sussex NJ-Warren NJ-Somerset NJ-
503 PM EDT Fri Sep 8 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR HUNTERDON...SOUTHWESTERN MORRIS...SOUTH CENTRAL SUSSEX...
SOUTHEASTERN WARREN AND NORTHWESTERN SOMERSET COUNTIES...

At 503 PM EDT, a severe thunderstorm was located over Long Valley, or
14 miles west of Morristown, moving northeast at 20 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...
Morristown, Bridgewater, Dover, Hopatcong, Hackettstown, Wharton,
Morris Plains, Mount Arlington, Mendham, Flemington, High Bridge,
Stanhope, Netcong, Clinton, Peapack And Gladstone, Glen Gardner,
Chester, Victory Gardens, Hampton and Lebanon.

This includes the following highways...
 Interstate 78 in New Jersey between mile markers 11 and 33.
 Interstate 80 in New Jersey between mile markers 18 and 32.
 Interstate 287 in New Jersey between mile markers 20 and 39.

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.

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

&&

LAT...LON 4041 7487 4057 7508 4100 7481 4081 7441
TIME...MOT...LOC 2103Z 216DEG 19KT 4080 7476 

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

$$

MLB
380 
WWUS51 KPHI 082128
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
528 PM EDT Fri Sep 8 2023

NJC019-027-035-037-041-082137-
/O.EXP.KPHI.SV.W.0338.000000T0000Z-230908T2130Z/
Hunterdon NJ-Morris NJ-Sussex NJ-Warren NJ-Somerset NJ-
528 PM EDT Fri Sep 8 2023

...THE SEVERE THUNDERSTORM WARNING FOR HUNTERDON...SOUTHWESTERN
MORRIS...SOUTH CENTRAL SUSSEX...SOUTHEASTERN WARREN AND NORTHWESTERN
SOMERSET COUNTIES WILL EXPIRE AT 530 PM EDT...
                
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 and heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
northern and northwestern New Jersey.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

Remember, a Severe Thunderstorm Warning still remains in effect for
Southwestern Hunterdon County until 6:00 PM EDT.

LAT...LON 4041 7487 4057 7508 4100 7481 4081 7441
TIME...MOT...LOC 2127Z 216DEG 19KT 4089 7467 

$$

MLB

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 9:46 PM EDTSpecial Weather StatementPHISussex29 min
Sep 8, 6:02 AM EDTSpecial Marine WarningPHI40 min
Sep 8, 1:36 PM EDTSpecial Weather StatementPHIBurlington24 min
Sep 8, 1:37 PM EDTSpecial Weather StatementPHIMonmouth23 min
Sep 8, 1:46 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean44 min
Sep 8, 1:50 PM EDTSpecial Marine WarningPHI115 min
Sep 8, 1:54 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean51 min
Sep 8, 2:27 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth48 min
Sep 8, 2:30 PM EDTSevere Thunderstorm WarningPHIBurlington, Middlesex, Monmouth, Ocean45 min
Sep 8, 2:33 PM EDTAreal Flood AdvisoryPHIBurlington, Monmouth, Ocean3 hr
Sep 8, 2:44 PM EDTSpecial Marine WarningPHI18 min
Sep 8, 2:45 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean45 min
Sep 8, 2:53 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Somerset52 min
Sep 8, 3:17 PM EDTSpecial Marine WarningPHI58 min
Sep 8, 3:27 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Monmouth, Ocean63 min
Sep 8, 3:29 PM EDTFlash Flood WarningPHIBurlington, Ocean4 hr
Sep 8, 3:31 PM EDTSevere Thunderstorm WarningPHICumberland, Salem44 min
Sep 8, 3:36 PM EDTSevere Thunderstorm WarningPHIMorris30 min
Sep 8, 3:43 PM EDTSpecial Weather StatementPHIMiddlesex32 min
Sep 8, 3:58 PM EDTSpecial Weather StatementPHISomerset32 min
Sep 8, 4:24 PM EDTSevere Thunderstorm WarningPHIHunterdon51 min
Sep 8, 4:27 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean51 min
Sep 8, 4:30 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Monmouth, Ocean60 min
Sep 8, 5:12 PM EDTAreal Flood AdvisoryPHIHunterdon3 hr
Sep 8, 5:14 PM EDTSevere Thunderstorm WarningPHIHunterdon46 min
Sep 8, 5:21 PM EDTFlash Flood WarningPHIHunterdon4 hr
Sep 8, 5:34 PM EDTSevere Thunderstorm WarningPHIWarren41 min
Sep 8, 5:49 PM EDTSevere Thunderstorm WarningPHISussex41 min
Sep 8, 6:11 PM EDTSpecial Weather StatementPHIWarren34 min
Sep 8, 6:34 PM EDTAreal Flood AdvisoryPHISussex, Warren3 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2023Every severe thunderstorm warning 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.