Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 4, NWS New York, NY

April 21, 20215 counties in New York; 4 counties in New Jersey

NWS New York, NY issued this severe thunderstorm warning at Apr 21, 2021, 2:12 PM EDT for 5 counties in New York; 4 counties in New Jersey. It was in force for 48 min. 3 reports 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
Apr 21, 2021, 2:12 PM EDT (18:12 UTC)
Expired
Apr 21, 2021, 3:00 PM EDT
In force
48 min
Issued by
NWS New York, NY
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Passaic County, NJ, Bronx County, NY, Nassau County, NY, New York County, NY, Queens County, NY, Westchester County, NY

The radar

The Brookhaven radar (KOKX), 94 km from the middle of the area, began a volume at 18:15 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

TimeReportWhereRemark
Apr 21, 2:18 PM EDTTSTM WND DMG1 Sw Ridgewood, NJCORRECTS TIME PREVIOUS TSTM WND DMG REPORT FROM 1 SW RIDGEWOOD. CORRECTS TIME FROM PREVIOUS TSTM WND DMG REPORT FROM 1 SW RIDGEWOOD. TREE DOWN, BLOCKING BELMONT AVENUE.
Apr 21, 2:25 PM EDTHAIL 0.752 Se Midtown Manhattan, NY
Apr 21, 2:41 PM EDTTSTM WND DMG1 Sw Ridgewood, NJTREE DOWN, BLOCKING BELMONT AVENUE.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 21, 12:28 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 6.2 hours before the alert went out and 94 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 12:00Z on 2021-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 206 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1427 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
206 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

501 
WUUS51 KOKX 211812
SVROKX
NJC003-013-017-031-NYC005-059-061-081-119-211900-
/O.NEW.KOKX.SV.W.0004.210421T1812Z-210421T1900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service New York NY
212 PM EDT Wed Apr 21 2021

The National Weather Service in Upton NY has issued a

* Severe Thunderstorm Warning for...
  Hudson County in northeastern New Jersey...
  Eastern Passaic County in northeastern New Jersey...
  Bergen County in northeastern New Jersey...
  Essex County in northeastern New Jersey...
  Southern Westchester County in southeastern New York...
  Queens County in southeastern New York...
  Bronx County in southeastern New York...
  New York (Manhattan) County in southeastern New York...
  Northwestern Nassau County in southeastern New York...

* Until 300 PM EDT.

* At 211 PM EDT, a severe thunderstorm was located over Passaic,
  moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines.

* This severe thunderstorm will be near...
  Lyndhurst and Rutherford around 215 PM EDT.
  Hoboken and Hackensack around 220 PM EDT.
  Bergenfield and Ridgefield around 225 PM EDT.
  Mott Haven and RFK Bridge around 230 PM EDT.
  Yonkers and Flushing around 235 PM EDT.
  New Rochelle and Throgs Neck Bridge around 240 PM EDT.
  Great Neck and Sands Point around 245 PM EDT.
  Garden City and Mineola around 250 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4071 7392 4074 7395 4071 7397 4074 7437
      4086 7432 4090 7434 4089 7428 4091 7427
      4093 7429 4097 7428 4101 7434 4098 7367
      4094 7367 4090 7374 4086 7375 4088 7372
      4086 7366 4089 7365 4069 7360
TIME...MOT...LOC 1811Z 270DEG 36KT 4084 7416 

HAIL...<.75IN
WIND...60MPH
 
$$
2 follow-up statements
748 
WWUS51 KOKX 211840
SVSOKX

Severe Weather Statement
National Weather Service New York NY
240 PM EDT Wed Apr 21 2021

NJC003-013-017-031-NYC061-119-211850-
/O.CAN.KOKX.SV.W.0004.000000T0000Z-210421T1900Z/
Hudson NJ-Passaic NJ-Bergen NJ-Essex NJ-Westchester NY-
New York (Manhattan) NY-
240 PM EDT Wed Apr 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR HUDSON...EASTERN PASSAIC...
BERGEN...ESSEX...SOUTHERN WESTCHESTER AND NEW YORK (MANHATTAN)
COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
southeastern New York.

LAT...LON 4071 7387 4088 7389 4089 7382 4088 7379
      4090 7378 4089 7376 4086 7375 4088 7371
      4086 7366 4089 7365 4069 7360
TIME...MOT...LOC 1840Z 265DEG 30KT 4080 7379 

$$

NYC005-059-081-211900-
/O.CON.KOKX.SV.W.0004.000000T0000Z-210421T1900Z/
Queens NY-Bronx NY-Nassau NY-
240 PM EDT Wed Apr 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR QUEENS...BRONX AND NORTHWESTERN NASSAU COUNTIES...

At 240 PM EDT, a severe thunderstorm was located over Bayside, or
over Throgs Neck Bridge, moving east at 35 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and power lines.

This severe storm will be near...
  Great Neck and Elmont around 245 PM EDT.
  Garden City and Port Washington around 250 PM EDT.
  Mineola and Hempstead around 255 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4071 7387 4088 7389 4089 7382 4088 7379
      4090 7378 4089 7376 4086 7375 4088 7371
      4086 7366 4089 7365 4069 7360
TIME...MOT...LOC 1840Z 265DEG 30KT 4080 7379 

HAIL...0.75IN
WIND...60MPH
 
$$
962 
WWUS51 KOKX 211857
SVSOKX

Severe Weather Statement
National Weather Service New York NY
257 PM EDT Wed Apr 21 2021

NYC005-059-081-211906-
/O.EXP.KOKX.SV.W.0004.000000T0000Z-210421T1900Z/
Queens NY-Bronx NY-Nassau NY-
257 PM EDT Wed Apr 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR QUEENS...BRONX AND
NORTHWESTERN NASSAU COUNTIES WILL EXPIRE AT 300 PM EDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
southeastern New York.

LAT...LON 4071 7387 4088 7389 4089 7382 4088 7379
      4090 7378 4089 7376 4086 7375 4088 7371
      4086 7366 4089 7365 4069 7360
TIME...MOT...LOC 1856Z 270DEG 36KT 4080 7360 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 20, 8:48 PM EDTFreeze WatchOKXOrange, Putnam7 hr
Apr 21, 3:41 AM EDTFreeze WarningOKXOrange, Putnam, Rockland, Westchester29 hr
Apr 21, 10:58 AM EDTSpecial Weather StatementOKXNassau47 min
Apr 21, 12:52 PM EDTSpecial Weather StatementOKXSuffolk23 min
Apr 21, 1:23 PM EDTSpecial Weather StatementOKXOrange, Rockland67 min
Apr 21, 1:41 PM EDTSevere Thunderstorm WarningOKXOrange, Rockland64 min
Apr 21, 2:05 PM EDTSpecial Weather StatementOKXBronx, Kings, Nassau, New York, Putnam, Queens and 2 more85 min
Apr 21, 2:10 PM EDTSevere Thunderstorm WarningOKXPutnam50 min
Apr 21, 2:14 PM EDTSpecial Marine WarningOKX61 min
Apr 21, 2:28 PM EDTSevere Thunderstorm WarningOKXWestchester47 min
Apr 21, 2:34 PM EDTSpecial Marine WarningOKX86 min
Apr 21, 2:53 PM EDTSevere Thunderstorm WarningOKXPutnam, Westchester67 min
Apr 21, 3:07 PM EDTSpecial Marine WarningOKX113 min
Apr 21, 3:17 PM EDTSevere Thunderstorm WarningOKXNassau, Suffolk19 min

Nearby

Severe Thunderstorm Warnings in New York, 2021Severe Thunderstorm Warnings in New Jersey, 2021Every severe thunderstorm warning 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.