Alert archive / New York / Flash Flood Warnings in 2012

Flash Flood Warning 1, NWS New York, NY

May 9, 2012Rockland County, Westchester County, New York

NWS New York, NY issued this flash flood warning at May 9, 2012, 5:45 PM EDT for Rockland County, Westchester County, New York. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 9, 2012, 5:45 PM EDT (21:45 UTC)
Expired
May 9, 2012, 9:15 PM EDT
In force
4 hr
Issued by
NWS New York, NY
Area
Storm-based polygon
Flood severity
None

Counties Rockland County, NY, Westchester County, NY

The radar

The Brookhaven radar (KOKX), 100 km from the middle of the area, began a volume at 21:46 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, 9.8 hours before the alert went out and 100 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 2012-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 2012-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 148 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
451 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
217 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.

558 
WGUS51 KOKX 092145
FFWOKX
NYC087-119-092345-
/O.NEW.KOKX.FF.W.0001.120509T2145Z-120509T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW YORK NY
545 PM EDT WED MAY 9 2012

THE NATIONAL WEATHER SERVICE IN UPTON NY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WESTCHESTER COUNTY IN SOUTHEAST NEW YORK...
  ROCKLAND COUNTY IN SOUTHEAST NEW YORK...

* UNTIL 745 PM EDT...

* AT 541 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM A CLUSTER OF SHOWERS AND THUNDERSTORMS THAT 
CONTINUE TO GENERATE OVER THE WARNED AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4126 7405 4131 7384 4117 7379 4113 7407

$$

DSW
3 follow-up statements
443 
WGUS71 KOKX 092250
FFSOKX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW YORK NY
650 PM EDT WED MAY 9 2012

NYC087-119-092345-
/O.CON.KOKX.FF.W.0001.000000T0000Z-120509T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ROCKLAND NY-WESTCHESTER NY-
650 PM EDT WED MAY 9 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM EDT FOR
WESTCHESTER AND ROCKLAND COUNTIES...

AT 646 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE AN AREA OF SHOWERS AND THUNDERSTORMS THAT CONTINUES TO 
DEVELOP AND TRAIN ACROSS THE WARNED AREA. RADAR ESTIMATES 2 TO 3 
INCHES OF RAINFALL ACROSS PARTS OF THE AREA WITH THE POTENTIAL FOR 
AN ADDITIONAL INCH. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4114 7403 4124 7400 4131 7384 4117 7379

$$

DSW
187 
WGUS51 KOKX 092339
FFWOKX
NYC087-119-100115-
/O.EXT.KOKX.FF.W.0001.000000T0000Z-120510T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW YORK NY
739 PM EDT WED MAY 9 2012

THE NATIONAL WEATHER SERVICE IN UPTON NY HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  WESTCHESTER COUNTY IN SOUTHEAST NEW YORK...
  ROCKLAND COUNTY IN SOUTHEAST NEW YORK...

* UNTIL 915 PM EDT...

* AT 734 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  CONTINUOUS DEVELOPMENT OF HEAVY RAIN PRODUCING SHOWERS             
  AND THUNDERSTORMS OVER THE WARNED AREA. RADAR HAS ESTIMATED        
  THAT SEVERAL INCHES OF RAINFALL HAS FALLEN ACROSS THIS AREA WITH   
  THE POTENTIAL FOR UP TO ANOTHER INCH OF RAINFALL.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4114 7403 4124 7400 4131 7384 4117 7379

$$

DSW
261 
WGUS71 KOKX 100108
FFSOKX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW YORK NY
908 PM EDT WED MAY 9 2012

NYC087-119-100117-
/O.EXP.KOKX.FF.W.0001.000000T0000Z-120510T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ROCKLAND NY-WESTCHESTER NY-
908 PM EDT WED MAY 9 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 915 PM EDT FOR WESTCHESTER
AND ROCKLAND COUNTIES...

THE THREAT FOR FLASH FLOODING HAS DIMINISHED AT THIS POINT AND ANY 
ADDITIONAL FLOODING THIS EVENING IS EXPECTED TO BE MINOR.

LAT...LON 4114 7403 4124 7400 4131 7384 4117 7379

$$

JM

The office that day

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

IssuedProductOfficeCountiesLasted
May 9, 5:20 PM EDTAreal Flood AdvisoryOKXRockland, Westchester55 min
May 9, 7:40 PM EDTMarine Dense Fog AdvisoryOKX9 hr

Nearby

Flash Flood Warnings in New York, 2012Every flash flood warning in 2012

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.