Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 67, NWS New York, NY

August 12, 20214 counties in New York

NWS New York, NY issued this severe thunderstorm warning at Aug 12, 2021, 5:04 PM EDT for 4 counties in New York. It was in force for 22 min. 2 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
Aug 12, 2021, 5:04 PM EDT (21:04 UTC)
Expired
Aug 12, 2021, 5:26 PM EDT
In force
22 min
Issued by
NWS New York, NY
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Orange County, NY, Putnam County, NY, Rockland County, NY, Westchester County, NY

The radar

The Brookhaven radar (KOKX), 91 km from the middle of the area, began a volume at 21:06 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
Aug 12, 5:14 PM EDTTSTM WND DMG1 Nnw Buckberg, NYTREES DOWN ACROSS ROAD IN BEAR MOUNTAIN STATE PARK.
Aug 12, 5:14 PM EDTTSTM WND DMG3 Ssw Fort Montgomery, NYTREES DOWN ACROSS ROAD IN BEAR MOUNTAIN STATE PARK.

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 12:00Z, 9.1 hours before the alert went out and 91 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 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 278 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 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -82 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
278 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
1400 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-82 m²/s²
0-3 km storm-relative helicity
-47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

066 
WUUS51 KOKX 122104
SVROKX
NYC071-079-087-119-122145-
/O.NEW.KOKX.SV.W.0067.210812T2104Z-210812T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service New York NY
504 PM EDT Thu Aug 12 2021

The National Weather Service in Upton NY has issued a

* Severe Thunderstorm Warning for...
  Northern Westchester County in southeastern New York...
  Southeastern Orange County in southeastern New York...
  Western Putnam County in southeastern New York...
  Rockland County in southeastern New York...

* Until 545 PM EDT.

* At 504 PM EDT, a severe thunderstorm was located near Peekskill,
  moving east at 25 mph.

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

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Peekskill and Haverstraw around 515 PM EDT.
  Ossining around 525 PM EDT.
  Yorktown Heights around 535 PM EDT.
  Mount Kisco around 540 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4135 7355 4134 7355 4112 7377 4121 7420
      4137 7411
TIME...MOT...LOC 2104Z 279DEG 23KT 4128 7403 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$
1 follow-up statement
220 
WWUS51 KOKX 122126
SVSOKX

Severe Weather Statement
National Weather Service New York NY
526 PM EDT Thu Aug 12 2021

NYC071-079-087-119-122136-
/O.CAN.KOKX.SV.W.0067.000000T0000Z-210812T2145Z/
Westchester NY-Orange NY-Putnam NY-Rockland NY-
526 PM EDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN WESTCHESTER...
SOUTHEASTERN ORANGE...WESTERN PUTNAM AND ROCKLAND COUNTIES IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has weakened.
Therefore, the warning has been cancelled.

LAT...LON 4135 7355 4134 7355 4112 7377 4121 7420
      4137 7411
TIME...MOT...LOC 2125Z 279DEG 23KT 4126 7384 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 8:32 PM EDTSpecial Weather StatementOKXWestchester28 min
Aug 11, 8:39 PM EDTAreal Flood AdvisoryOKXKings, New York, Queens, Richmond2 hr
Aug 11, 9:00 PM EDTSpecial Marine WarningOKX30 min
Aug 11, 9:01 PM EDTSpecial Weather StatementOKXKings, New York, Richmond29 min
Aug 11, 9:25 PM EDTSpecial Weather StatementOKXKings, Queens35 min
Aug 11, 9:27 PM EDTSpecial Marine WarningOKX33 min
Aug 12, 4:07 PM EDTSevere Thunderstorm WarningOKXOrange, Rockland41 min
Aug 12, 4:21 PM EDTSpecial Weather StatementOKXDutchess24 min
Aug 12, 4:39 PM EDTSpecial Weather StatementOKXBronx, New York51 min
Aug 12, 4:45 PM EDTSpecial Marine WarningOKX90 min
Aug 12, 4:53 PM EDTSpecial Weather StatementOKXRockland52 min
Aug 12, 5:20 PM EDTSpecial Weather StatementOKXNassau40 min
Aug 12, 5:53 PM EDTSpecial Weather StatementOKXSuffolk52 min

Nearby

Severe Thunderstorm Warnings in New York, 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.