Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 255, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 2021, 8:10 PM EDT for 4 counties in New Jersey. It was in force for 35 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
- Aug 11, 2021, 8:10 PM EDT (00:10 UTC)
- Expired
- Aug 11, 2021, 8:45 PM EDT
- In force
- 35 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Hunterdon County, NJ, Morris County, NJ, Sussex County, NJ, Warren County, NJ
The radar
The Philadelphia radar (KDIX), 95 km from the middle of the area, began a volume at 00:11 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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 11, 3:02 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 0.2 hours before the alert went out and 160 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.
- Mixed-layer CAPE
- 1528 J/kg
- Mixed-layer CIN
- -105 J/kg
- Mixed-layer LCL
- 942 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 101 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
303
WUUS51 KPHI 120010
SVRPHI
NJC019-027-037-041-120045-
/O.NEW.KPHI.SV.W.0255.210812T0010Z-210812T0045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
810 PM EDT Wed Aug 11 2021
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Northeastern Hunterdon County in northwestern New Jersey...
Southwestern Morris County in northern New Jersey...
South central Sussex County in northwestern New Jersey...
Central Warren County in northwestern New Jersey...
* Until 845 PM EDT.
* At 810 PM EDT, a severe thunderstorm was located over Glen Gardner,
or 15 miles east of Easton, moving northeast 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...
Dover, Hopatcong, Hackettstown, Wharton, Washington, Rockaway,
Morris Plains, Mount Arlington, Mendham, High Bridge, Stanhope,
Netcong, Clinton, Oxford, Glen Gardner, Chester, Victory Gardens,
Hampton, Califon and Andover.
This includes the following highways...
Interstate 78 in New Jersey between mile markers 9 and 17.
Interstate 80 in New Jersey between mile markers 19 and 36, and
between mile markers 41 and 42.
Interstate 287 in New Jersey near mile marker 41.
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 4072 7470 4071 7473 4059 7499 4073 7512
4101 7471 4085 7441
TIME...MOT...LOC 0010Z 235DEG 31KT 4072 7493
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JEO2 follow-up statements
942
WWUS51 KPHI 120018
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
818 PM EDT Wed Aug 11 2021
NJC019-027-037-041-120045-
/O.CON.KPHI.SV.W.0255.000000T0000Z-210812T0045Z/
Hunterdon NJ-Morris NJ-Sussex NJ-Warren NJ-
818 PM EDT Wed Aug 11 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR NORTHEASTERN HUNTERDON...SOUTHWESTERN MORRIS...SOUTH CENTRAL
SUSSEX AND EAST CENTRAL WARREN COUNTIES...
At 818 PM EDT, a severe thunderstorm was located over Califon, or 18
miles northwest of Somerville, moving northeast at 35 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Dover, Hopatcong, Hackettstown, Wharton, Washington, Rockaway, Morris
Plains, Mount Arlington, Mendham, High Bridge, Stanhope, Netcong,
Oxford, Glen Gardner, Chester, Victory Gardens, Hampton, Califon,
Andover and Brass Castle.
This includes the following highways...
Interstate 80 in New Jersey between mile markers 19 and 36, and
between mile markers 41 and 42.
Interstate 287 in New Jersey near mile marker 41.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4072 7470 4071 7473 4065 7485 4078 7505
4101 7471 4085 7441
TIME...MOT...LOC 0018Z 235DEG 31KT 4076 7485
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JEO782
WWUS51 KPHI 120039
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
839 PM EDT Wed Aug 11 2021
NJC019-027-037-041-120049-
/O.EXP.KPHI.SV.W.0255.000000T0000Z-210812T0045Z/
Hunterdon NJ-Morris NJ-Sussex NJ-Warren NJ-
839 PM EDT Wed Aug 11 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN HUNTERDON...
SOUTHWESTERN MORRIS...SOUTH CENTRAL SUSSEX AND EAST CENTRAL WARREN
COUNTIES WILL EXPIRE AT 845 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 are still possible with this thunderstorm.
A Severe Thunderstorm Watch remains in effect until 900 PM EDT for
northwestern New Jersey.
LAT...LON 4072 7470 4071 7473 4065 7485 4078 7505
4101 7471 4085 7441
TIME...MOT...LOC 0039Z 235DEG 31KT 4085 7468
$$
JEOThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 10:54 PM EDT | Areal Flood Warning | PHI | Morris, Warren | 3 hr |
| Aug 12, 3:33 PM EDT | Severe Thunderstorm Warning | PHI | Sussex, Warren | 57 min |
| Aug 12, 4:11 PM EDT | Severe Thunderstorm Warning | PHI | Morris, Sussex, Warren | 34 min |
Nearby
Severe Thunderstorm Warnings in New Jersey, 2021Every severe thunderstorm warning 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.