Alert archive / New York / Flash Flood Warnings in 2011

Flash Flood Warning 34, NWS New York, NY

August 21, 2011Kings County, Nassau County, Queens County, New York

NWS New York, NY issued this flash flood warning at Aug 21, 2011, 8:18 PM EDT for Kings County, Nassau County, Queens County, New York. It was in force for 97 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 21, 2011, 8:18 PM EDT (00:18 UTC)
Expired
Aug 21, 2011, 9:55 PM EDT
In force
97 min
Issued by
NWS New York, NY
Area
Storm-based polygon
Flood severity
None

Counties Kings County, NY, Nassau County, NY, Queens County, NY

The radar

The Brookhaven radar (KOKX), 71 km from the middle of the area, began a volume at 00:19 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 21, 8:40 PM EDTFLASH FLOODWoodmere, NYINTERSECTION OF PENNISULA BLVD WOODMERE BLVD CLOSED DUE TO FLOODING
Aug 21, 8:56 PM EDTFLASH FLOODNorth Woodmere, NYCARS STRANDED WITH PEOPLE TRAPPED IN FLOOD WATERS AT 147TH DRIVE AND HOOK CREEK BLVD.

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, 0.3 hours before the alert went out and 71 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 2011-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1559 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 2011-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 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
1559 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
748 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
204 m²/s²
Significant tornado parameter
0.7
Supercell composite
6.1

Open this sounding in Storm Lab

The text

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

097 
WGUS51 KOKX 220018
FFWOKX
NYC047-059-081-220215-
/O.NEW.KOKX.FF.W.0034.110822T0018Z-110822T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW YORK NY
818 PM EDT SUN AUG 21 2011

THE NATIONAL WEATHER SERVICE IN UPTON NY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NASSAU COUNTY IN SOUTHEAST NEW YORK...
  QUEENS COUNTY IN SOUTHEAST NEW YORK...
  KINGS (BROOKLYN) COUNTY IN SOUTHEAST NEW YORK...

* UNTIL 1015 PM EDT...

* AT 812 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THUNDERSTORMS PRODUCING HEAVY RAIN OVER SOUTHERN BROOKLYN...QUEENS 
  AND NASSAU COUNTIES. RAINFALL RATES ARE BETWEEN 1 AND 1 1/2 INCHES 
  PER HOUR AND ARE BACK BUILDING OVER THE SAME AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

&&

LAT...LON 4056 7391 4056 7392 4062 7376 4063 7376
      4064 7391 4058 7393 4058 7394 4081 7381
      4092 7352 4066 7342 4064 7348 4061 7342
      4059 7356 4060 7356 4064 7349 4064 7352
      4061 7364 4059 7356 4058 7358

$$
1 follow-up statement
027 
WGUS71 KOKX 220155
FFSOKX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW YORK NY
955 PM EDT SUN AUG 21 2011

NYC047-059-081-220202-
/O.CAN.KOKX.FF.W.0034.000000T0000Z-110822T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KINGS (BROOKLYN) NY-QUEENS NY-NASSAU NY-
955 PM EDT SUN AUG 21 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NASSAU...QUEENS AND
KINGS (BROOKLYN) COUNTIES...

HEAVY RAIN THAT PRODUCED FLASH FLOODING NEAR THE SOUTHERN QUEENS AND 
NASSAU COUNTY LINE HAS EXITED THE AREA. THE IMMINENT THREAT FOR 
FLASH FLOODING HAS ENDED THEREFORE THE WARNING HAS BEEN CANCELLED.

LAT...LON 4056 7391 4056 7392 4062 7376 4063 7376
      4064 7391 4058 7393 4058 7394 4081 7381
      4092 7352 4066 7342 4064 7348 4061 7342
      4059 7356 4060 7356 4064 7349 4064 7352
      4061 7364 4059 7356 4058 7358

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 8:42 PM EDTSpecial Marine WarningOKX63 min
Aug 21, 9:18 PM EDTSpecial Marine WarningOKX57 min
Aug 21, 9:23 PM EDTSpecial Weather StatementOKXSuffolk37 min
Aug 21, 9:33 PM EDTFlash Flood WarningOKXSuffolk39 min
Aug 21, 9:44 PM EDTSpecial Marine WarningOKX91 min
Aug 21, 10:26 PM EDTSpecial Marine WarningOKX64 min

Nearby

Flash Flood Warnings in New York, 2011Every flash flood 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.