Alert archive / New York / Flash Flood Warnings in 2009

Flash Flood Warning 27, NWS Buffalo, NY

August 12, 2009Allegany County, New York

NWS Buffalo, NY issued this flash flood warning at Aug 12, 2009, 4:23 PM EDT for Allegany 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, 4:23 PM EDT (20:23 UTC)
Expired
Aug 12, 2009, 7:04 PM EDT
In force
3 hr
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

County Allegany County, NY

The radar

The Buffalo radar (KBUF), 112 km from the middle of the area, began a volume at 20:24 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, 8.4 hours before the alert went out and 109 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 122023
FFWBUF
NYC003-122315-
/O.NEW.KBUF.FF.W.0027.090812T2023Z-090812T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN BUFFALO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN ALLEGANY COUNTY IN WESTERN NEW YORK...

* UNTIL 715 PM EDT

* AT 417 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
VERY HEAVY RAIN FROM A NEARLY STATIONARY THUNDERSTORM OVER SOUTHWEST 
ALLEGANY COUNTY...INCLUDING SITES SUCH AS BOLIVAR...LITTLE GENESEE 
AND RICHBURG. RADAR ESTIMATES THAT 2 TO 3 INCHES OF RAIN HAD FALLEN 
OVER THIS AREA BETWEEN 3:30 AND 4:15 PM. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN 
BUFFALO.
&&

LAT...LON 4200 7817 4199 7821 4199 7830 4212 7830
      4212 7808 4199 7808 4199 7817

$$

RSH
2 follow-up statements
000 
WGUS71 KBUF 122148
FFSBUF

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

NYC003-122315-
/O.CON.KBUF.FF.W.0027.000000T0000Z-090812T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALLEGANY NY-
548 PM EDT WED AUG 12 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM EDT FOR
SOUTHWESTERN ALLEGANY COUNTY...

AT 547 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 715 PM. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RICHBURG AND
BOLIVAR

LAT...LON 4200 7817 4199 7821 4199 7830 4212 7830
      4212 7808 4199 7808 4199 7817

$$

SFM
000 
WGUS71 KBUF 122304
FFSBUF

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

NYC003-122319-
/O.CAN.KBUF.FF.W.0027.000000T0000Z-090812T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALLEGANY NY-
704 PM EDT WED AUG 12 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHWESTERN
ALLEGANY COUNTY...

WHILE THE THUNDERSTORMS THAT PROMPTED THE WARNING HAVE LONG SINCE 
DISSIPATED...PONDING OF LOW LYING AND POOR DRAINAGE AREAS WILL BE 
POSSIBLE FOR AWHILE LONGER THIS EVENING UNTIL THE WATER HAS TIME TO 
RUN OFF.

LAT...LON 4200 7817 4199 7821 4199 7830 4212 7830
      4212 7808 4199 7808 4199 7817

$$

JJR

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, 4:34 PM EDTFlash Flood WarningBUFCattaraugus3 hr
Aug 12, 5:30 PM EDTFlash Flood WarningBUFOntario3 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.