Alert archive / New Jersey / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

July 9, 2021Morris County, Warren County, New Jersey; Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 9, 2021, 8:09 PM EDT for Morris County, Warren County, New Jersey; Northampton County, Pennsylvania. It was in force for 66 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
Jul 9, 2021, 8:09 PM EDT (00:09 UTC)
Expired
Jul 9, 2021, 9:15 PM EDT
In force
66 min
Issued by
NWS Philadelphia/Mount Holly

Counties Morris County, NJ, Warren County, NJ, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 99 km from the middle of the area, began a volume at 00:09 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 nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.2 hours before the alert went out and 137 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 2021-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 547 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 2021-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 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
547 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
981 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.2
Supercell composite
3.5

Open this sounding in Storm Lab

The text

As transmitted.

088 
WWUS81 KPHI 100009
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
809 PM EDT Fri Jul 9 2021

NJZ001-007>010-PAZ055-062-100115-
Hunterdon-Morris-Sussex-Somerset-Warren-Monroe-Northampton-
809 PM EDT Fri Jul 9 2021

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT NORTHEASTERN
HUNTERDON...MORRIS...SOUTHWESTERN SUSSEX...WARREN...NORTHERN
SOMERSET...SOUTHEASTERN MONROE AND NORTHEASTERN NORTHAMPTON
COUNTIES...

At 809 PM EDT, strong thunderstorms were clustered over Hackettstown,
or 12 miles south of Newton, moving east at 40 mph.

Wind gusts up to 40 mph are possible with this storm.

Locations impacted include...
Easton, Morristown, Newton, Dover, Madison, Hopatcong, Forks, Florham
Park, East Hanover, Kinnelon, East Stroudsburg, Hackettstown,
Chatham, Boonton, Wilson, Butler, Wharton, Washington, Rockaway and
Blairstown.

This includes the following highways...
 Interstate 78 in New Jersey near mile marker 42.
 Interstate 80 in Pennsylvania between mile markers 303 and 314.
 Interstate 80 in New Jersey between mile markers 0 and 48.
 Interstate 287 in New Jersey between mile markers 23 and 54.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 4090 7431 4091 7433 4089 7434 4083 7433
      4079 7437 4076 7438 4075 7436 4068 7445
      4066 7445 4066 7440 4065 7441 4071 7540
      4106 7531 4104 7444 4102 7443 4100 7430
TIME...MOT...LOC 0009Z 260DEG 35KT 4087 7482 

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 8:25 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Ocean65 min
Jul 9, 8:28 PM EDTSpecial Marine WarningPHI2 hr
Jul 9, 9:12 PM EDTAreal Flood AdvisoryPHIMorris, Sussex2 hr
Jul 9, 8:34 PM EDTSpecial Weather StatementPHISussex26 min

Nearby

Special Weather Statements in New Jersey, 2021Special Weather Statements in Pennsylvania, 2021Every special weather statement in 2021

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.