Alert archive / New Jersey / Tornado Watches in 2020
Tornado Watch 416
The Storm Prediction Center issued this tornado watch at Aug 4, 2020, 7:23 AM EDT for 4 states. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 4, 2020, 7:23 AM EDT (11:23 UTC)
- Expired
- Aug 4, 2020, 4:00 PM EDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 50 kt
All 38 counties
Greater Bridgeport Planning Region, CT, Lower Connecticut River Valley Planning Region, CT, Naugatuck Valley Planning Region, CT, Southeastern Connecticut Planning Region, CT, Atlantic County, NJ, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Suffolk County, NY, Westchester County, NY, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 46 km from the middle of the area, began a volume at 11:26 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 70%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 10%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 20%
Warnings issued inside it
16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 4, 7:23 AM EDT | Tornado Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 20 min |
| Aug 4, 7:28 AM EDT | Flash Flood Warning | PHI | Gloucester, Salem | 3 hr |
| Aug 4, 8:11 AM EDT | Flash Flood Warning | PHI | Bucks, Lehigh, Montgomery, Northampton | 4 hr |
| Aug 4, 8:19 AM EDT | Tornado Warning | PHI | Bucks | 26 min |
| Aug 4, 9:23 AM EDT | Tornado Warning | PHI | Chester | 22 min |
| Aug 4, 9:42 AM EDT | Tornado Warning | PHI | Atlantic, Cape May | 19 min |
| Aug 4, 10:02 AM EDT | Flash Flood Warning | PHI | Gloucester, Salem | 4 hr |
| Aug 4, 10:15 AM EDT | Tornado Warning | PHI | Atlantic, Burlington, Ocean | 14 min |
| Aug 4, 10:20 AM EDT | Flash Flood Warning | PHI | Burlington, Camden, Gloucester | 4 hr |
| Aug 4, 10:51 AM EDT | Tornado Warning | PHI | Montgomery | 24 min |
| Aug 4, 11:00 AM EDT | Tornado Warning | PHI | Monmouth, Ocean | 11 min |
| Aug 4, 11:01 AM EDT | Flash Flood Warning | PHI | Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Ocean and 1 more | 4 hr |
| Aug 4, 11:43 AM EDT | Flash Flood Warning | PHI | Warren | 4 hr |
| Aug 4, 1:38 PM EDT | Tornado Warning | OKX | Greater Bridgeport Planning Region | 37 min |
| Aug 4, 2:05 PM EDT | Tornado Warning | OKX | Lower Connecticut River Valley Planning Region | 25 min |
| Aug 4, 2:49 PM EDT | Tornado Warning | OKX | Lower Connecticut River Valley Planning Region | 15 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 11.4 hours before the alert went out and 147 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
- 560 J/kg
- Mixed-layer CIN
- -65 J/kg
- Mixed-layer LCL
- 1172 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 83 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 4, 6:45 AM EDT | Mesoscale Discussion | SPC | 3 hr | |
| Aug 4, 11:13 AM EDT | Mesoscale Discussion | SPC | 92 min | |
| Aug 4, 11:34 AM EDT | Mesoscale Discussion | SPC | 86 min | |
| Aug 4, 12:43 PM EDT | Tornado Watch | SPC | Capitol Planning Region, Northwest Hills Planning Region, Northeastern Connecticut Planning Region | 6 hr |
| Aug 4, 3:05 PM EDT | Mesoscale Discussion | SPC | 85 min | |
| Aug 4, 2:26 AM EDT | Tornado Watch | SPC | Cape May, Cumberland, Salem | 9 hr |
| Aug 4, 5:15 AM EDT | Mesoscale Discussion | SPC | Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 1 more | 3 hr |
| Aug 4, 8:59 AM EDT | Mesoscale Discussion | SPC | Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 5 more | 91 min |
Nearby
Tornado Watches in New Jersey, 2020Tornado Watches in New York, 2020Tornado Watches in Pennsylvania, 2020Every tornado watch in 2020
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.