Alert archive / New Jersey / Tornado Warnings in 2021

Tornado Warning 34, NWS Philadelphia/Mount Holly

August 19, 2021Morris County, New Jersey

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 19, 2021, 2:40 AM EDT for Morris County, New Jersey. It was in force for 24 min. 1 report 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 19, 2021, 2:40 AM EDT (06:40 UTC)
Expired: Aug 19, 2021, 3:04 AM EDT
In force: 24 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Morris County, NJ

The radar

The Philadelphia radar (KDIX), 118 km from the middle of the area, began a volume at 06:39 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 19, 2:40 AM EDT	TSTM WND DMG	1 Nw Rockaway, NJ	PHOTOS OF SEVERAL TREES DOWN IN ROADWAYS AND IN POWER LINES ALONG KATHERINE AND RESERVOIR ROADS. DAMAGE MAY BE TORNADIC BASED ON RADAR SIGNATURES. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 6.7 hours before the alert went out and 135 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: 491 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 580 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 103 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

718 
WFUS51 KPHI 190640
TORPHI
NJC027-190715-
/O.NEW.KPHI.TO.W.0034.210819T0640Z-210819T0715Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
240 AM EDT Thu Aug 19 2021

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  Northeastern Morris County in northern New Jersey...

* Until 315 AM EDT.
    
* At 240 AM EDT, a severe thunderstorm capable of producing a tornado
  was located over Rockaway, or 8 miles north of Morristown, moving
  northeast at 25 mph.

  HAZARD...Tornado.

  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...
  Rockaway, Lake Telemark, Green Pond and White Meadow Lake. 

This includes Interstate 80 in New Jersey between mile markers 35 and
38.
 
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.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4104 7443 4102 7443 4103 7442 4101 7437
      4088 7451 4092 7457 4104 7450 4105 7447
      4105 7445
TIME...MOT...LOC 0640Z 213DEG 22KT 4092 7453 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

Meola

2 follow-up statements

458 
WWUS51 KPHI 190656
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
256 AM EDT Thu Aug 19 2021

NJC027-190715-
/O.CON.KPHI.TO.W.0034.000000T0000Z-210819T0715Z/
Morris NJ-
256 AM EDT Thu Aug 19 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 315 AM EDT FOR
NORTHEASTERN MORRIS COUNTY...
    
At 255 AM EDT, a severe thunderstorm capable of producing a tornado
was located over Green Pond, or 7 miles southwest of West Milford,
moving northeast at 25 mph.

HAZARD...Tornado.

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...
Lake Telemark and Green Pond. 

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.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4104 7443 4102 7443 4103 7442 4101 7437
      4092 7446 4097 7452 4104 7450 4105 7447
      4105 7445
TIME...MOT...LOC 0655Z 213DEG 22KT 4100 7446 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

Meola

991 
WWUS51 KPHI 190704
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
304 AM EDT Thu Aug 19 2021

NJC027-190714-
/O.CAN.KPHI.TO.W.0034.000000T0000Z-210819T0715Z/
Morris NJ-
304 AM EDT Thu Aug 19 2021

...THE TORNADO WARNING FOR NORTHEASTERN MORRIS COUNTY IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

LAT...LON 4104 7443 4102 7443 4103 7442 4101 7437
      4092 7446 4097 7452 4104 7450 4105 7447
      4105 7445
TIME...MOT...LOC 0703Z 213DEG 22KT 4105 7442 

$$

Meola

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 11:19 PM EDT	Areal Flood Advisory	PHI	Warren	3 hr
Aug 19, 12:48 AM EDT	Tornado Warning	PHI	Hunterdon	27 min
Aug 19, 1:32 AM EDT	Small Craft Advisory	PHI		5 hr
Aug 19, 2:05 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Morris, Somerset	3 hr
Aug 19, 2:13 AM EDT	Flash Flood Warning	PHI	Burlington, Camden, Mercer	4 hr
Aug 19, 2:33 AM EDT	Tornado Warning	PHI	Morris	27 min
Aug 19, 3:09 AM EDT	Tornado Warning	PHI	Mercer, Middlesex, Monmouth	36 min
Aug 19, 6:09 AM EDT	Areal Flood Warning	PHI	Mercer	3 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.