Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 31, NWS New York, NY

June 30, 2021Nassau County, Suffolk County, New York

NWS New York, NY issued this severe thunderstorm warning at Jun 30, 2021, 9:24 PM EDT for Nassau County, Suffolk County, New York. It was in force for 29 min. 1 report 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
Jun 30, 2021, 9:24 PM EDT (01:24 UTC)
Expired
Jun 30, 2021, 9:53 PM EDT
In force
29 min
Issued by
NWS New York, NY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Nassau County, NY, Suffolk County, NY

The radar

The Brookhaven radar (KOKX), 45 km from the middle of the area, began a volume at 01:23 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
Jun 30, 9:30 PM EDTTSTM WND DMGGlen Cove, NYGLEN COVE REPORTS NUMEROUS TREES DOWN ACROSS THE AREA.

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 00:00Z, 1.4 hours before the alert went out and 45 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 2021-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1308 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 2021-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 square meters per square second.193958Sfc1 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
1308 J/kg
Mixed-layer CIN
-130 J/kg
Mixed-layer LCL
1402 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

599 
WUUS51 KOKX 010124
SVROKX
NYC059-103-010215-
/O.NEW.KOKX.SV.W.0031.210701T0124Z-210701T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service New York NY
924 PM EDT Wed Jun 30 2021

The National Weather Service in Upton NY has issued a

* Severe Thunderstorm Warning for...
  Western Suffolk County in southeastern New York...
  Northeastern Nassau County in southeastern New York...

* Until 1015 PM EDT.

* At 923 PM EDT, a severe thunderstorm was located over Glen Cove,
  moving east at 30 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor hail damage to vehicles is possible. Expect wind 
           damage to trees and power lines.

* This severe thunderstorm will be near...
  Plainview and Syosset around 935 PM EDT.
  Melville and Cold Spring Harbor around 940 PM EDT.
  Huntington Station and Huntington around 945 PM EDT.
  Northport and Dix Hills around 950 PM EDT.
  Commack around 955 PM EDT.
  Brentwood around 1000 PM EDT.
  Hauppauge and Smithtown around 1005 PM EDT.
  Ronkonkoma and Stony Brook around 1010 PM EDT.
  Centereach and Port Jefferson around 1015 PM EDT.

This includes the following New York State COVID tent site 
SUNY Stony Brook.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4078 7368 4087 7368 4087 7366 4091 7364
      4093 7352 4095 7350 4094 7342 4096 7341
      4096 7338 4094 7334 4095 7329 4092 7322
      4093 7317 4098 7317 4098 7300 4075 7303
TIME...MOT...LOC 0123Z 271DEG 26KT 4086 7359 

HAIL...1.00IN
WIND...60MPH
 
$$

MW
1 follow-up statement
897 
WWUS51 KOKX 010153
SVSOKX

Severe Weather Statement
National Weather Service New York NY
953 PM EDT Wed Jun 30 2021

NYC059-103-010202-
/O.CAN.KOKX.SV.W.0031.000000T0000Z-210701T0215Z/
Suffolk NY-Nassau NY-
953 PM EDT Wed Jun 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN SUFFOLK AND
NORTHEASTERN NASSAU COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds up 
to 40 mph are still possible with this thunderstorm.

LAT...LON 4078 7368 4087 7368 4087 7366 4091 7364
      4093 7352 4095 7350 4094 7342 4096 7341
      4096 7338 4094 7334 4095 7329 4092 7322
      4093 7317 4098 7317 4098 7300 4075 7303
TIME...MOT...LOC 0150Z 271DEG 26KT 4086 7331 

$$

MW

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 8:29 PM EDTSpecial Marine WarningOKX61 min
Jun 30, 8:31 PM EDTSpecial Weather StatementOKXNassau44 min
Jun 30, 8:37 PM EDTSevere Thunderstorm WarningOKXSuffolk38 min
Jun 30, 8:41 PM EDTSpecial Weather StatementOKXBronx, New York49 min
Jun 30, 8:55 PM EDTSpecial Marine WarningOKX35 min
Jun 30, 9:06 PM EDTSpecial Weather StatementOKXNassau39 min
Jun 30, 9:07 PM EDTSpecial Weather StatementOKXRichmond38 min
Jun 30, 9:30 PM EDTSpecial Marine WarningOKX60 min
Jun 30, 9:38 PM EDTSpecial Marine WarningOKX67 min
Jun 30, 9:39 PM EDTSevere Thunderstorm WarningOKXKings, Nassau, New York, Queens, Richmond51 min
Jun 30, 9:57 PM EDTSpecial Weather StatementOKXBronx, New York33 min
Jun 30, 10:00 PM EDTSpecial Marine WarningOKX45 min
Jun 30, 10:22 PM EDTSpecial Weather StatementOKXNassau23 min
Jun 30, 10:45 PM EDTSpecial Weather StatementOKXNassau45 min
Jun 30, 11:27 PM EDTSpecial Weather StatementOKXSuffolk93 min
Jul 1, 10:47 AM EDTFlash Flood WatchOKXBronx, Kings, Nassau, New York, Queens, Richmond and 1 more10 hr
Jul 1, 7:42 PM EDTSpecial Marine WarningOKX50 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.