Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 253, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 2021, 7:04 PM EDT for Morris County, Sussex County, Warren County, New Jersey. It was in force for 41 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
- Aug 11, 2021, 7:04 PM EDT (23:04 UTC)
- Expired
- Aug 11, 2021, 7:45 PM EDT
- In force
- 41 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Morris County, NJ, Sussex County, NJ, Warren County, NJ
The radar
The Philadelphia radar (KDIX), 104 km from the middle of the area, began a volume at 23:07 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 11, 7:05 PM EDT | TSTM WND DMG | 1 Ne Hackettstown, NJ | MULTIPLE TREES SNAPPED AND WIRES BLOWN DOWN NEAR THE INTERSECTION OF BILBY ROAD AND WILLOW GROVE STREET. TIME ESTIMATED FROM RADAR. |
| Aug 11, 7:15 PM EDT | TSTM WND DMG | Long Valley, NJ | SEVERAL DOWNED TREE AND WIRE CALLS IN AND NEAR LONG VALLEY. TIME ESTIMATED FROM RADAR. |
| Aug 11, 7:25 PM EDT | TSTM WND DMG | 1 Nw Randolph, NJ | DOWNED WIRES ON NJ 10 EASTBOUND NEAR DOVER CHESTER ROAD. TIME ESTIMATED FROM RADAR. |
| Aug 11, 7:25 PM EDT | TSTM WND DMG | 1 Nw Randolph, NJ | WIRES WERE DOWNED ON NJ-10 EASTBOUND NEAR DOVER CHESTER RD, WITH LANE RESTRICTIONS. TIME ESTIMATED FROM RADAR. |
| Aug 11, 7:25 PM EDT | TSTM WND DMG | Randolph, NJ | SEVERAL DOWNED TREE AND WIRE CALLS IN AND NEAR RANDOLPH. TIME ESTIMATED FROM RADAR. |
| Aug 11, 7:40 PM EDT | TSTM WND DMG | Morristown, NJ | SEVERAL DOWNED TREE AND WIRE CALLS IN AND NEAR MORRISTOWN. TIME ESTIMATED FROM RADAR. |
| Aug 11, 7:52 PM EDT | TSTM WND DMG | Hackettstown, NJ | CORRECTS PREVIOUS NON-TSTM WND DMG REPORT FROM HACKETTSTOWN. VIDEO OF A TREE DOWN ON POWER LINES. TIME ESTIMATED FROM RADAR. REPORT VIA SOCIAL MEDIA. |
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.
| 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 12:00Z, 11.1 hours before the alert went out and 141 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
- 977 J/kg
- Mixed-layer CIN
- -44 J/kg
- Mixed-layer LCL
- 711 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 29 m²/s²
- 0-3 km storm-relative helicity
- 18 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
213
WUUS51 KPHI 112304
SVRPHI
NJC027-037-041-112345-
/O.NEW.KPHI.SV.W.0253.210811T2304Z-210811T2345Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
704 PM EDT Wed Aug 11 2021
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Morris County in northern New Jersey...
Southeastern Sussex County in northwestern New Jersey...
Central Warren County in northwestern New Jersey...
* Until 745 PM EDT.
* At 704 PM EDT, a severe thunderstorm was located over Budd Lake, or
14 miles south of Newton, moving east at 20 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...
Morristown, Dover, Madison, Hopatcong, Florham Park, East Hanover,
Lincoln Park, Kinnelon, Hackettstown, Boonton, Butler, Wharton,
Washington, Rockaway, Morris Plains, Mount Arlington, Mendham,
Mountain Lakes, Stanhope and Riverdale.
This includes the following highways...
Interstate 80 in New Jersey between mile markers 12 and 48.
Interstate 287 in New Jersey between mile markers 31 and 54.
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 4090 7429 4091 7434 4084 7433 4078 7437
4075 7445 4074 7455 4076 7456 4072 7472
4078 7488 4076 7492 4076 7505 4090 7506
4109 7450 4104 7450 4105 7445 4102 7443
4100 7430 4097 7428
TIME...MOT...LOC 2304Z 255DEG 19KT 4085 7475
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JEO3 follow-up statements
636
WWUS51 KPHI 112321
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
721 PM EDT Wed Aug 11 2021
NJC027-037-041-112345-
/O.CON.KPHI.SV.W.0253.000000T0000Z-210811T2345Z/
Morris NJ-Sussex NJ-Warren NJ-
721 PM EDT Wed Aug 11 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR MORRIS...SOUTH CENTRAL SUSSEX AND EAST CENTRAL WARREN COUNTIES...
At 721 PM EDT, a severe thunderstorm was located over
Succasunna-Kenvil, or 9 miles northwest of Morristown, moving east at
20 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Morristown, Dover, Madison, Hopatcong, Florham Park, East Hanover,
Lincoln Park, Kinnelon, Hackettstown, Boonton, Butler, Wharton,
Rockaway, Morris Plains, Mount Arlington, Mendham, Mountain Lakes,
Stanhope, Riverdale and Netcong.
This includes the following highways...
Interstate 80 in New Jersey between mile markers 17 and 48.
Interstate 287 in New Jersey between mile markers 31 and 54.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Frequent cloud to ground lightning is occurring with this storm. Move
indoors immediately. Lightning is one of nature's leading killers.
Remember, if you can hear thunder, you are close enough to be struck
by lightning.
&&
LAT...LON 4090 7429 4091 7434 4084 7433 4078 7437
4075 7445 4074 7455 4076 7456 4072 7472
4078 7488 4076 7492 4089 7504 4095 7476
4093 7467 4100 7460 4102 7449 4100 7430
4097 7428
TIME...MOT...LOC 2321Z 255DEG 19KT 4087 7464
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JEO959
WWUS51 KPHI 112333
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
733 PM EDT Wed Aug 11 2021
NJC037-112343-
/O.CAN.KPHI.SV.W.0253.000000T0000Z-210811T2345Z/
Sussex NJ-
733 PM EDT Wed Aug 11 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL SUSSEX COUNTY 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 900 PM EDT for
northwestern New Jersey.
LAT...LON 4090 7429 4091 7434 4084 7433 4078 7437
4075 7445 4074 7455 4076 7456 4072 7472
4078 7488 4076 7492 4083 7485 4088 7474
4090 7466 4095 7459 4096 7446 4098 7430
4097 7428
TIME...MOT...LOC 2333Z 255DEG 19KT 4089 7455
$$
NJC027-041-112345-
/O.CON.KPHI.SV.W.0253.000000T0000Z-210811T2345Z/
Morris NJ-Warren NJ-
733 PM EDT Wed Aug 11 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR MORRIS AND EAST CENTRAL WARREN COUNTIES...
At 733 PM EDT, a severe thunderstorm was located over Dover, or 7
miles northwest of Morristown, moving east at 20 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Morristown, Dover, Madison, Florham Park, East Hanover, Lincoln Park,
Hackettstown, Boonton, Wharton, Rockaway, Morris Plains, Mount
Arlington, Mendham, Mountain Lakes, Chester, Victory Gardens, Long
Valley, Succasunna, Succasunna-Kenvil and Parsippany.
This includes the following highways...
Interstate 80 in New Jersey between mile markers 28 and 48.
Interstate 287 in New Jersey between mile markers 31 and 52.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4090 7429 4091 7434 4084 7433 4078 7437
4075 7445 4074 7455 4076 7456 4072 7472
4078 7488 4076 7492 4083 7485 4088 7474
4090 7466 4095 7459 4096 7446 4098 7430
4097 7428
TIME...MOT...LOC 2333Z 255DEG 19KT 4089 7455
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JEO519
WWUS51 KPHI 112343
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
743 PM EDT Wed Aug 11 2021
NJC027-041-112353-
/O.EXP.KPHI.SV.W.0253.000000T0000Z-210811T2345Z/
Morris NJ-Warren NJ-
743 PM EDT Wed Aug 11 2021
...THE SEVERE THUNDERSTORM WARNING FOR MORRIS AND EAST CENTRAL WARREN
COUNTIES WILL EXPIRE AT 745 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 4090 7429 4091 7434 4084 7433 4078 7437
4075 7445 4074 7455 4076 7456 4072 7472
4078 7488 4076 7492 4083 7485 4088 7474
4090 7466 4095 7459 4096 7446 4098 7430
4097 7428
TIME...MOT...LOC 2343Z 255DEG 19KT 4090 7449
$$
JEOThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 8:02 PM EDT | Severe Thunderstorm Warning | PHI | Camden, Gloucester | 43 min |
| Aug 10, 8:18 PM EDT | Severe Thunderstorm Warning | PHI | Gloucester, Salem | 42 min |
| Aug 10, 8:23 PM EDT | Special Marine Warning | PHI | 79 min | |
| Aug 10, 8:36 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Burlington, Camden, Cumberland, Gloucester, Salem | 39 min |
| Aug 10, 8:43 PM EDT | Areal Flood Advisory | PHI | Burlington, Camden, Gloucester | 2 hr |
| Aug 10, 9:07 PM EDT | Special Weather Statement | PHI | Burlington, Camden, Cumberland | 23 min |
| Aug 11, 2:56 PM EDT | Excessive Heat Watch | PHI | Hunterdon, Morris, Warren | 12 hr |
| Aug 11, 5:57 PM EDT | Special Weather Statement | PHI | Sussex | 48 min |
| Aug 11, 6:32 PM EDT | Special Weather Statement | PHI | Morris, Sussex, Warren | 28 min |
| Aug 11, 6:50 PM EDT | Areal Flood Advisory | PHI | Hunterdon, Morris, Somerset, Sussex, Warren | 3 hr |
| Aug 11, 7:04 PM EDT | Areal Flood Advisory | PHI | Gloucester, Hunterdon, Salem | 2 hr |
| Aug 11, 7:11 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Camden, Gloucester | 49 min |
| Aug 11, 7:28 PM EDT | Flash Flood Warning | PHI | Morris, Warren | 3 hr |
| Aug 11, 7:45 PM EDT | Special Weather Statement | PHI | Morris | 45 min |
| Aug 11, 7:52 PM EDT | Special Weather Statement | PHI | Atlantic, Burlington, Camden, Gloucester, Mercer | 53 min |
| Aug 11, 7:57 PM EDT | Special Weather Statement | PHI | Hunterdon, Middlesex, Somerset | 48 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.