Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 186, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2021, 5:30 PM EDT for Hunterdon County, Warren County, New Jersey; Bucks County, Pennsylvania. It was in force for 19 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 17, 2021, 5:30 PM EDT (21:30 UTC)
- Expired
- Jul 17, 2021, 5:49 PM EDT
- In force
- 19 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Hunterdon County, NJ, Warren County, NJ, Bucks County, PA
The radar
The Philadelphia radar (KDIX), 85 km from the middle of the area, began a volume at 21:33 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 |
|---|---|---|---|
| Jul 17, 1:13 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
The nearest sounding before it
Brookhaven, NY (KOKX), launched 12:00Z, 9.5 hours before the alert went out and 189 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
- 1203 J/kg
- Mixed-layer CIN
- -55 J/kg
- Mixed-layer LCL
- 1054 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 35 m²/s²
- 0-3 km storm-relative helicity
- 46 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.0
The text
As transmitted.
008
WUUS51 KPHI 172130
SVRPHI
NJC019-041-PAC017-172215-
/O.NEW.KPHI.SV.W.0186.210717T2130Z-210717T2215Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
530 PM EDT Sat Jul 17 2021
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Central Hunterdon County in northwestern New Jersey...
Southwestern Warren County in northwestern New Jersey...
North central Bucks County in southeastern Pennsylvania...
* Until 615 PM EDT.
* At 529 PM EDT, a severe thunderstorm was located over Erwinna, or
14 miles southeast of Easton, moving northeast at 40 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Minor damage to vehicles is possible. Wind damage to
roofs, siding, trees, and power lines is possible.
* Locations impacted include...
Byram, Bedminster, Washington, Tinicum, High Bridge, Clinton,
Alpha, Glen Gardner, Ferndale, Hampton, Frenchtown, Milford,
Bloomsbury, Riegelsville, Pleasant Valley, Revere, Ottsville,
Pipersville, Erwinna and Annandale.
This includes Interstate 78 in New Jersey between mile markers 2 and
19.
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 4035 7507 4044 7528 4079 7509 4069 7482
TIME...MOT...LOC 2129Z 214DEG 36KT 4050 7510
TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
$$
Davis2 follow-up statements
985
WWUS51 KPHI 172139
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
539 PM EDT Sat Jul 17 2021
NJC019-041-PAC017-172215-
/O.CON.KPHI.SV.W.0186.000000T0000Z-210717T2215Z/
Hunterdon NJ-Warren NJ-Bucks PA-
539 PM EDT Sat Jul 17 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR CENTRAL HUNTERDON...SOUTHWESTERN WARREN AND NORTH CENTRAL BUCKS
COUNTIES...
At 538 PM EDT, a severe thunderstorm was located near Milford, or 12
miles southeast of Easton, moving northeast at 40 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Minor damage to vehicles is possible. Wind damage to roofs,
siding, trees, and power lines is possible.
Locations impacted include...
Washington, Tinicum, High Bridge, Clinton, Alpha, Glen Gardner,
Ferndale, Hampton, Frenchtown, Milford, Bloomsbury, Pleasant Valley,
Revere, Ottsville, Erwinna, Annandale and Brass Castle.
This includes Interstate 78 in New Jersey between mile markers 3 and
19.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4043 7502 4046 7524 4079 7509 4069 7482
TIME...MOT...LOC 2138Z 214DEG 36KT 4058 7503
TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
$$
Davis918
WWUS51 KPHI 172149
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
549 PM EDT Sat Jul 17 2021
NJC019-041-PAC017-172159-
/O.CAN.KPHI.SV.W.0186.000000T0000Z-210717T2215Z/
Hunterdon NJ-Warren NJ-Bucks PA-
549 PM EDT Sat Jul 17 2021
...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL HUNTERDON...
SOUTHWESTERN WARREN AND NORTH CENTRAL BUCKS COUNTIES IS CANCELLED...
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 has been cancelled. However gusty winds are
still possible with this thunderstorm.
A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
northwestern New Jersey...and southeastern Pennsylvania.
LAT...LON 4043 7502 4046 7524 4079 7509 4069 7482
TIME...MOT...LOC 2148Z 214DEG 36KT 4068 7495
$$
DavisThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 12:55 PM EDT | Special Weather Statement | PHI | Hunterdon | 50 min |
| Jul 17, 1:05 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer | 40 min |
| Jul 17, 1:31 PM EDT | Areal Flood Advisory | PHI | Hunterdon | 97 min |
| Jul 17, 1:50 PM EDT | Special Marine Warning | PHI | 40 min | |
| Jul 17, 1:56 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Morris, Somerset, Warren | 36 min |
| Jul 17, 2:02 PM EDT | Areal Flood Advisory | PHI | Monmouth, Ocean | 92 min |
| Jul 17, 2:56 PM EDT | Severe Thunderstorm Warning | PHI | Middlesex, Somerset | 49 min |
| Jul 17, 3:06 PM EDT | Severe Thunderstorm Warning | PHI | Warren | 39 min |
| Jul 17, 3:09 PM EDT | Tornado Warning | PHI | Middlesex | 21 min |
| Jul 17, 3:38 PM EDT | Areal Flood Advisory | PHI | Middlesex | 40 min |
| Jul 17, 3:51 PM EDT | Severe Thunderstorm Warning | PHI | Middlesex | 24 min |
| Jul 17, 4:55 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Somerset | 50 min |
| Jul 17, 5:13 PM EDT | Areal Flood Advisory | PHI | Hunterdon | 4 hr |
| Jul 17, 5:19 PM EDT | Tornado Warning | PHI | Hunterdon | 14 min |
| Jul 17, 5:25 PM EDT | Flash Flood Warning | PHI | Hunterdon | 6 hr |
| Jul 17, 5:52 PM EDT | Areal Flood Advisory | PHI | Somerset | 2 hr |
| Jul 17, 6:02 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer, Somerset | 43 min |
| Jul 17, 6:15 PM EDT | Flash Flood Warning | PHI | Morris, Somerset | 5 hr |
| Jul 17, 6:39 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer, Middlesex, Morris, Somerset | 51 min |
| Jul 17, 6:51 PM EDT | Severe Thunderstorm Warning | PHI | Burlington | 39 min |
| Jul 17, 6:59 PM EDT | Small Craft Advisory | PHI | 7 hr | |
| Jul 17, 7:01 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Somerset | 44 min |
| Jul 17, 7:12 PM EDT | Areal Flood Advisory | PHI | Mercer, Somerset | 3 hr |
| Jul 17, 7:26 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer, Middlesex, Morris, Somerset | 49 min |
| Jul 16, 8:14 PM EDT | Special Weather Statement | PHI | Montgomery | 31 min |
| Jul 16, 8:41 PM EDT | Special Weather Statement | PHI | Bucks | 34 min |
| Jul 16, 9:07 PM EDT | Special Weather Statement | PHI | Lehigh | 23 min |
| Jul 16, 9:29 PM EDT | Special Weather Statement | PHI | Lehigh | 31 min |
| Jul 16, 10:21 PM EDT | Special Weather Statement | PHI | Lehigh | 24 min |
| Jul 17, 2:30 PM EDT | Special Weather Statement | PHI | Berks | 45 min |
| Jul 17, 2:36 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 39 min |
| Jul 17, 7:36 PM EDT | Special Weather Statement | PHI | Carbon | 54 min |
Nearby
Severe Thunderstorm Warnings in New Jersey, 2021Severe Thunderstorm Warnings in Pennsylvania, 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.