Alert archive / New York / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 39, NWS New York, NY

July 29, 2011Nassau County, Suffolk County, New York

NWS New York, NY issued this severe thunderstorm warning at Jul 29, 2011, 6:42 PM EDT for Nassau County, Suffolk County, New York. It was in force for 48 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
Jul 29, 2011, 6:42 PM EDT (22:42 UTC)
Expired
Jul 29, 2011, 7:30 PM EDT
In force
48 min
Issued by
NWS New York, NY
Area
Storm-based polygon

Counties Nassau County, NY, Suffolk County, NY

The radar

The Brookhaven radar (KOKX), 62 km from the middle of the area, began a volume at 22:44 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 12:00Z, 10.7 hours before the alert went out and 62 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 2011-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 81 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 2011-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
81 J/kg
Mixed-layer CIN
-109 J/kg
Mixed-layer LCL
569 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
19 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

911 
WUUS51 KOKX 292242
SVROKX
NYC059-103-292330-
/O.NEW.KOKX.SV.W.0039.110729T2242Z-110729T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NEW YORK NY
642 PM EDT FRI JUL 29 2011

THE NATIONAL WEATHER SERVICE IN UPTON NY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NASSAU COUNTY IN SOUTHEAST NEW YORK...
  WESTERN SUFFOLK COUNTY IN SOUTHEAST NEW YORK...

* UNTIL 730 PM EDT...

* AT 637 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN      
  EXCESS OF 70 MPH.  THIS STORM WAS LOCATED OVER SOUTHERN            
  WESTCHESTER COUNTY AND MOVING SOUTHEAST AT 30 MPH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS THUNDERSTORM HAS ROTATION AND COULD PRODUCE A TORNADO. IF A 
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A 
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD 
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A 
SHELTER...PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 4084 7374 4087 7373 4088 7371 4085 7366
      4088 7366 4091 7361 4092 7352 4089 7348
      4094 7349 4076 7328 4064 7353 4063 7362
TIME...MOT...LOC 2240Z 318DEG 27KT 4097 7368

$$

JM
3 follow-up statements
340 
WWUS51 KOKX 292305
SVSOKX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW YORK NY
705 PM EDT FRI JUL 29 2011

NYC059-103-292330-
/O.CON.KOKX.SV.W.0039.000000T0000Z-110729T2330Z/
SUFFOLK NY-NASSAU NY-
705 PM EDT FRI JUL 29 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR NORTHEASTERN NASSAU AND WESTERN SUFFOLK COUNTIES...

AT 701 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR EAST NORWICH...OR NEAR OYSTER BAY...MOVING SOUTHEAST AT
30 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO COLD
SPRING HARBOR...JERICHO...SYOSSET...WOODBURY...HICKSVILLE...
HUNTINGTON STATION...WEST HILLS...PLAINVIEW...SOUTH HUNTINGTON...
BETHPAGE...LEVITTOWN...MELVILLE...PLAINEDGE...FARMINGDALE...DIX
HILLS...EAST FARMINGDALE...WYANDANCH AND DEER PARK

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE 
STRUCK BY LIGHTNING.

&&

LAT...LON 4088 7365 4091 7361 4092 7352 4089 7348
      4094 7349 4076 7328 4067 7347
TIME...MOT...LOC 2304Z 318DEG 27KT 4084 7352

$$

JM
566 
WWUS51 KOKX 292320
SVSOKX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW YORK NY
720 PM EDT FRI JUL 29 2011

NYC059-103-292330-
/O.CON.KOKX.SV.W.0039.000000T0000Z-110729T2330Z/
SUFFOLK NY-NASSAU NY-
720 PM EDT FRI JUL 29 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR EAST CENTRAL NASSAU AND WESTERN SUFFOLK COUNTIES...

AT 718 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR PLAINVIEW...MOVING SOUTHEAST AT 30 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
MELVILLE...DIX HILLS...EAST FARMINGDALE...WYANDANCH AND DEER PARK

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

&&

LAT...LON 4071 7342 4085 7357 4089 7343 4076 7328
TIME...MOT...LOC 2320Z 315DEG 26KT 4078 7344

$$

JM
599 
WWUS51 KOKX 292330
SVSOKX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW YORK NY
730 PM EDT FRI JUL 29 2011

NYC059-103-292339-
/O.EXP.KOKX.SV.W.0039.000000T0000Z-110729T2330Z/
SUFFOLK NY-NASSAU NY-
730 PM EDT FRI JUL 29 2011

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL NASSAU AND
WESTERN SUFFOLK COUNTIES WILL EXPIRE AT 730 PM EDT...

THE THUNDERSTORM HAS WEAKENED TO BELOW SEVERE LEVELS BUT GUSTY WINDS 
UP TO 40 MPH AND SMALL HAIL WILL STILL BE POSSIBLE WITH THE 
THUNDERSTORM.


LAT...LON 4071 7342 4085 7357 4089 7343 4076 7328
TIME...MOT...LOC 2329Z 315DEG 26KT 4073 7338

$$

JM

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 4:01 AM EDTSmall Craft AdvisoryOKX19 hr
Jul 29, 4:19 PM EDTSpecial Weather StatementOKXOrange41 min
Jul 29, 4:32 PM EDTSevere Thunderstorm WarningOKXOrange43 min
Jul 29, 4:54 PM EDTTornado WarningOKXOrange36 min
Jul 29, 5:22 PM EDTTornado WarningOKXOrange, Rockland, Westchester38 min
Jul 29, 5:34 PM EDTSevere Thunderstorm WarningOKXOrange41 min
Jul 29, 5:57 PM EDTTornado WarningOKXRockland, Westchester33 min
Jul 29, 6:09 PM EDTSpecial Marine WarningOKX54 min
Jul 29, 6:16 PM EDTSevere Thunderstorm WarningOKXOrange44 min
Jul 29, 6:26 PM EDTTornado WarningOKXWestchester34 min
Jul 29, 6:49 PM EDTSevere Thunderstorm WarningOKXOrange, Rockland, Westchester27 min
Jul 29, 7:13 PM EDTSevere Thunderstorm WarningOKXKings, New York, Queens32 min
Jul 29, 7:32 PM EDTSpecial Weather StatementOKXNassau43 min
Jul 29, 7:39 PM EDTSpecial Marine WarningOKX36 min
Jul 29, 7:47 PM EDTSpecial Weather StatementOKXQueens28 min

Nearby

Severe Thunderstorm Warnings in New York, 2011Every severe thunderstorm warning in 2011

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.