Alert archive / New York / Flash Flood Warnings in 2009

Flash Flood Warning 29, NWS Buffalo, NY

August 12, 2009Ontario County, New York

NWS Buffalo, NY issued this flash flood warning at Aug 12, 2009, 5:30 PM EDT for Ontario County, New York. It was in force for 3 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
Aug 12, 2009, 5:30 PM EDT (21:30 UTC)
Expired
Aug 12, 2009, 8:30 PM EDT
In force
3 hr
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

County Ontario County, NY

The radar

The Buffalo radar (KBUF), 101 km from the middle of the area, began a volume at 21:33 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 9.5 hours before the alert went out and 98 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, Buffalo Intl Airport, NY at 12:00Z on 2009-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 483 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 12:00Z on 2009-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
483 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
745 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
21 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.

000 
WGUS51 KBUF 122130
FFWBUF
NYC069-130030-
/O.NEW.KBUF.FF.W.0029.090812T2130Z-090813T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BUFFALO NY
530 PM EDT WED AUG 12 2009

THE NATIONAL WEATHER SERVICE IN BUFFALO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL ONTARIO COUNTY IN WESTERN NEW YORK...

* UNTIL 830 PM EDT

* AT 526 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
  NEARLY STATIONARY THUNDERSTORM WITH VERY HEAVY RAIN OVER THE       
  WARNED AREA. RADAR ESTIMATES THAT THIS STORM HAS ALREADY PRODUCED  
  AS MUCH AS 1.5 TO 2 INCHES OF RAINFALL...WITH ANY ADDITIONAL       
  RAINFALL LIKELY TO LEAD TO FLASH FLOODING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.

&&

LAT...LON 4274 7760 4286 7757 4286 7755 4288 7755
      4288 7734 4274 7734

$$

JJR
2 follow-up statements
000 
WGUS71 KBUF 122256
FFSBUF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BUFFALO NY
656 PM EDT WED AUG 12 2009

NYC069-130030-
/O.CON.KBUF.FF.W.0029.000000T0000Z-090813T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ONTARIO NY-
656 PM EDT WED AUG 12 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM EDT FOR WEST
CENTRAL ONTARIO COUNTY...

AT 656 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT THE THUNDERSTORMS WHICH PRODUCED THE FLASH FLOODING OVER THE 
REGION HAVE DISSIPATED. HOWEVER...FLASH FLOODING IS STILL POSSIBLE 
FOR AWHILE LONGER UNTIL THE RUNOFF FROM THE STORMS HAS EASED. THE 
WARNING THEREFORE REMAINS IN EFFECT UNTIL 830 PM.

LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...BRISTOL 
AND THE BRISTOL HILLS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.

&&

LAT...LON 4274 7760 4286 7757 4286 7755 4288 7755
      4288 7734 4274 7734

$$

JJR
000 
WGUS71 KBUF 130023
FFSBUF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BUFFALO NY
823 PM EDT WED AUG 12 2009

NYC069-130033-
/O.EXP.KBUF.FF.W.0029.000000T0000Z-090813T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ONTARIO NY-
823 PM EDT WED AUG 12 2009

...THE FLASH FLOOD WARNING WILL EXPIRE AT 830 PM EDT FOR WEST CENTRAL
ONTARIO COUNTY...

AT 823 PM EDT NATIONAL WEATHER SERVICE RADAR SHOWED THAT THE
THUNDERSTORM THAT PROMPTED THE WARNING HAD EXITED THE AREA...THUS THE
FLOOD WARNING HAS BEEN ALLOWED TO EXPIRE.

LAT...LON 4274 7760 4286 7757 4286 7755 4288 7755
      4288 7734 4274 7734

$$

SFM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 8:02 PM EDTSpecial Marine WarningBUF88 min
Aug 12, 2:03 PM EDTAreal Flood AdvisoryBUFWyoming3 hr
Aug 12, 3:29 PM EDTFlash Flood WarningBUFLivingston98 min
Aug 12, 4:00 PM EDTFlash Flood WarningBUFAllegany3 hr
Aug 12, 4:23 PM EDTFlash Flood WarningBUFAllegany3 hr
Aug 12, 4:34 PM EDTFlash Flood WarningBUFCattaraugus3 hr

Nearby

Flash Flood Warnings in New York, 2009Every flash flood warning in 2009

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.