Alert archive / New York / Tornado Warnings in 2021

Tornado Warning 7, NWS New York, NY

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

NWS New York, NY issued this tornado warning at Aug 19, 2021, 3:48 AM EDT for Orange County, Rockland County, Westchester County, New York; Bergen County, New Jersey. It was in force for 27 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, 3:48 AM EDT (07:48 UTC)
Expired
Aug 19, 2021, 4:15 AM EDT
In force
27 min
Issued by
NWS New York, NY
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.0 in

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

The radar

The Brookhaven radar (KOKX), 105 km from the middle of the area, began a volume at 07:50 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, 7.8 hours before the alert went out and 105 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.

013 
WFUS51 KOKX 190748
TOROKX
NJC003-NYC071-087-119-190815-
/O.NEW.KOKX.TO.W.0007.210819T0748Z-210819T0815Z/

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

The National Weather Service in Upton NY has issued a

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

* Until 415 AM EDT.
    
* At 347 AM EDT, a severe thunderstorm capable of producing a tornado
  was located over Monsey, 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.

* This dangerous storm will be near...
  Nanuet around 355 AM EDT.
  Pomona around 400 AM EDT.
  New City and Nyack around 405 AM EDT.
  Haverstraw around 410 AM EDT.
  Ossining and Peekskill around 415 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 4135 7396 4132 7398 4133 7388 4118 7371
      4102 7406 4111 7422 4113 7421 4114 7423
      4139 7395
TIME...MOT...LOC 0747Z 229DEG 21KT 4111 7410 

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

$$
3 follow-up statements
269 
WWUS51 KOKX 190806
SVSOKX

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

NJC003-NYC071-087-119-190815-
/O.CON.KOKX.TO.W.0007.000000T0000Z-210819T0815Z/
Bergen NJ-Westchester NY-Orange NY-Rockland NY-
406 AM EDT Thu Aug 19 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 AM EDT FOR NORTH
CENTRAL BERGEN...NORTHERN WESTCHESTER...SOUTHEASTERN ORANGE AND
ROCKLAND COUNTIES...
    
At 405 AM EDT, a severe thunderstorm capable of producing a tornado
was located over New City, 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.

This dangerous storm will be near...
  Haverstraw and Stony Point around 410 AM EDT.
  Peekskill around 425 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 4135 7396 4132 7398 4133 7388 4118 7371
      4102 7406 4111 7422 4113 7421 4114 7423
      4139 7395
TIME...MOT...LOC 0805Z 229DEG 21KT 4118 7399 

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

$$

JC
875 
WWUS51 KOKX 190806 RRA
SVSOKX

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

NJC003-190816-
/O.CAN.KOKX.TO.W.0007.000000T0000Z-210819T0815Z/
Bergen NJ-
406 AM EDT Thu Aug 19 2021

...THE TORNADO WARNING FOR NORTH CENTRAL 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 4135 7396 4132 7398 4133 7388 4121 7375
      4108 7394 4105 7400 4114 7423 4139 7395
TIME...MOT...LOC 0806Z 224DEG 29KT 4121 7400 

$$

NYC071-087-119-190815-
/O.CON.KOKX.TO.W.0007.000000T0000Z-210819T0815Z/
Westchester NY-Orange NY-Rockland NY-
406 AM EDT Thu Aug 19 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 AM EDT FOR NORTHERN
WESTCHESTER...SOUTHEASTERN ORANGE AND ROCKLAND COUNTIES...
    
At 406 AM EDT, a severe thunderstorm capable of producing a tornado
was located near Pomona, or near Haverstraw, moving northeast at 35
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 around 410 AM EDT.
  Peekskill around 420 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 4135 7396 4132 7398 4133 7388 4121 7375
      4108 7394 4105 7400 4114 7423 4139 7395
TIME...MOT...LOC 0806Z 224DEG 29KT 4121 7400 

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

$$
831 
WWUS51 KOKX 190814
SVSOKX

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

NJC003-NYC071-087-119-190824-
/O.EXP.KOKX.TO.W.0007.000000T0000Z-210819T0815Z/
Bergen NJ-Westchester NY-Orange NY-Rockland NY-
414 AM EDT Thu Aug 19 2021

...THE TORNADO WARNING FOR NORTH CENTRAL BERGEN...NORTHERN
WESTCHESTER...SOUTHEASTERN ORANGE AND ROCKLAND COUNTIES WILL EXPIRE
AT 415 AM EDT...
    
The tornadic thunderstorm which prompted the warning has weakened. 
Therefore, the warning will be allowed to expire.

LAT...LON 4135 7396 4132 7398 4133 7388 4118 7371
      4102 7406 4111 7422 4113 7421 4114 7423
      4139 7395
TIME...MOT...LOC 0814Z 229DEG 21KT 4121 7394 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 3:21 AM EDTSpecial Weather StatementOKXRockland24 min
Aug 19, 3:30 AM EDTAreal Flood AdvisoryOKXRockland2 hr
Aug 19, 4:17 AM EDTTornado WarningOKXRockland, Westchester28 min
Aug 19, 4:44 AM EDTTornado WarningOKXPutnam, Rockland, Westchester31 min
Aug 19, 3:00 PM EDTSmall Craft AdvisoryOKX14 hr
Aug 19, 2:43 AM EDTSpecial Weather StatementOKXPassaic32 min
Aug 19, 2:53 AM EDTTornado WarningOKXPassaic23 min

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.