Alert archive / New York / Tornado Warnings in 2021

Tornado Warning 8, NWS New York, NY

August 19, 2021Bergen County, New Jersey; Rockland County, Westchester County, New York

NWS New York, NY issued this tornado warning at Aug 19, 2021, 4:17 AM EDT for Bergen County, New Jersey; Rockland County, Westchester County, New York. It was in force for 28 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
Aug 19, 2021, 4:17 AM EDT (08:17 UTC)
Expired
Aug 19, 2021, 4:45 AM EDT
In force
28 min
Issued by
NWS New York, NY
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Bergen County, NJ, Rockland County, NY, Westchester County, NY

The radar

The Brookhaven radar (KOKX), 102 km from the middle of the area, began a volume at 08:16 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 nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 8.3 hours before the alert went out and 102 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-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2021-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 491 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2021-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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.

018 
WFUS51 KOKX 190817
TOROKX
NJC003-NYC087-119-190845-
/O.NEW.KOKX.TO.W.0008.210819T0817Z-210819T0845Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service New York NY
417 AM EDT Thu Aug 19 2021

The National Weather Service in Upton NY has issued a

* Tornado Warning for...
  Northern Bergen County in northeastern New Jersey...
  Northern Westchester County in southeastern New York...
  Rockland County in southeastern New York...

* Until 445 AM EDT.
    
* At 417 AM EDT, a severe thunderstorm capable of producing a tornado
  was located near Pearl River, or near Ridgewood, moving north at 30
  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.

* This dangerous storm will be near...
  Monsey and Nanuet around 430 AM EDT.
  New City and Upper Nyack around 435 AM EDT.
  Ossining and Haverstraw around 440 AM EDT.
  Peekskill around 445 AM EDT.

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 4127 7375 4094 7406 4098 7417 4099 7419
      4099 7421 4126 7408 4132 7399 4133 7394
TIME...MOT...LOC 0817Z 201DEG 26KT 4103 7407 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

JC
1 follow-up statement
563 
WWUS51 KOKX 190834
SVSOKX

Severe Weather Statement
National Weather Service New York NY
434 AM EDT Thu Aug 19 2021

NJC003-190843-
/O.CAN.KOKX.TO.W.0008.000000T0000Z-210819T0845Z/
Bergen NJ-
434 AM EDT Thu Aug 19 2021

...THE TORNADO WARNING FOR NORTHERN BERGEN COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

LAT...LON 4127 7375 4103 7399 4109 7412 4110 7412
      4124 7405 4132 7399 4133 7393
TIME...MOT...LOC 0833Z 201DEG 26KT 4114 7401 

$$

NYC087-119-190845-
/O.CON.KOKX.TO.W.0008.000000T0000Z-210819T0845Z/
Westchester NY-Rockland NY-
434 AM EDT Thu Aug 19 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 AM EDT FOR NORTHERN
WESTCHESTER AND ROCKLAND COUNTIES...
    
At 433 AM EDT, a severe thunderstorm capable of producing a tornado
was located over New City, moving north at 30 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.

This dangerous storm will be near...
  Ossining and Haverstraw around 440 AM EDT.
  Peekskill around 455 AM EDT.
  Yorktown Heights around 500 AM EDT.

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 4127 7375 4103 7399 4109 7412 4110 7412
      4124 7405 4132 7399 4133 7393
TIME...MOT...LOC 0833Z 201DEG 26KT 4114 7401 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

JC

The office that day

Everything else NWS New York, NY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 19, 2:43 AM EDTSpecial Weather StatementOKXPassaic32 min
Aug 19, 2:53 AM EDTTornado WarningOKXPassaic23 min
Aug 19, 3:30 AM EDTAreal Flood AdvisoryOKXBergen, Essex, Passaic, Union2 hr
Aug 19, 3:48 AM EDTTornado WarningOKXBergen27 min
Aug 19, 3:21 AM EDTSpecial Weather StatementOKXRockland24 min
Aug 19, 4:44 AM EDTTornado WarningOKXPutnam, Rockland, Westchester31 min
Aug 19, 3:00 PM EDTSmall Craft AdvisoryOKX14 hr

Nearby

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