Alert archive / New Jersey / Tornado Warnings in 2021

Tornado Warning 13, NWS Philadelphia/Mount Holly

July 17, 2021Hunterdon County, New Jersey

NWS Philadelphia/Mount Holly issued this tornado warning at Jul 17, 2021, 5:19 PM EDT for Hunterdon County, New Jersey. It was in force for 14 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, 5:19 PM EDT (21:19 UTC)
Expired: Jul 17, 2021, 5:33 PM EDT
In force: 14 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

County Hunterdon County, NJ

The radar

The Philadelphia radar (KDIX), 74 km from the middle of the area, began a volume at 21:21 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, 9.3 hours before the alert went out and 175 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 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

Open this sounding in Storm Lab

The text

As transmitted.

811 
WFUS51 KPHI 172119
TORPHI
NJC019-172145-
/O.NEW.KPHI.TO.W.0013.210717T2119Z-210717T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
519 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  East central Hunterdon County in northwestern New Jersey...

* Until 545 PM EDT.
    
* At 518 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Sand Brook, or 17 miles west of Somerville, moving
  northeast at 20 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* Locations impacted include...
  Flemington and Sand Brook. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4045 7492 4048 7497 4061 7488 4055 7475
TIME...MOT...LOC 2118Z 222DEG 15KT 4048 7492 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

JEO

1 follow-up statement

649 
WWUS51 KPHI 172133
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
533 PM EDT Sat Jul 17 2021

NJC019-172142-
/O.CAN.KPHI.TO.W.0013.000000T0000Z-210717T2145Z/
Hunterdon NJ-
533 PM EDT Sat Jul 17 2021

...THE TORNADO WARNING FOR EAST CENTRAL HUNTERDON COUNTY IS
CANCELLED...
                
The rotation which prompted the warning has weakened, and no longer 
appears capable of producing a tornado. Therefore, the Tornado 
Warning has been cancelled. However, a Severe Thunderstorm Warning 
remains in effect for damaging winds in excess of 60 mph.

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

LAT...LON 4045 7492 4048 7497 4061 7488 4055 7475
TIME...MOT...LOC 2131Z 222DEG 15KT 4053 7487 

$$

JEO

The 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, 5:25 PM EDT	Flash Flood Warning	PHI	Hunterdon	6 hr
Jul 17, 5:30 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	19 min
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

Nearby

Tornado Warnings in New Jersey, 2021 Every tornado warning in 2021 Tornadoes 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.