Alert archive / New York / Flash Flood Warnings in 2009

Flash Flood Warning 26, NWS Buffalo, NY

August 12, 2009Allegany County, New York

NWS Buffalo, NY issued this flash flood warning at Aug 12, 2009, 4:00 PM EDT for Allegany County, New York. It was in force for 3 hr. 1 report 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 12, 2009, 4:00 PM EDT (20:00 UTC)
Expired: Aug 12, 2009, 6:51 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 20:00 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

Time	Report	Where	Remark
Aug 12, 4:45 PM EDT	FLASH FLOOD	Andover, NY	MUD SLIDE CLOSED ROUTE 21 JUST NORTH OF ANDOVER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 8.0 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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 122000
FFWBUF
NYC003-122300-
/O.NEW.KBUF.FF.W.0026.090812T2000Z-090812T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN BUFFALO HAS ISSUED A

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

* UNTIL 700 PM EDT

* AT 356 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A VERY SLOW MOVING THUNDERSTORM WITH HEAVY RAINFALL OVER EAST      
  CENTRAL ALLEGANY COUNTY BETWEEN ALFRED AND ANDOVER. RADAR          
  ESTIMATES THAT 2 TO 3 INCHES OF RAIN HAS FALLEN IN THE PAST HOUR.  
  ADDITIONAL RAINFALL OF AROUND AN INCH IS POSSIBLE IN THIS AREA.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL RESULT IN RAPID RISES ON 
SMALL STREAMS. FLOODING OF LOW LYING AREAS IS ALSO LIKELY. 
SIGNIFICANT RISES ARE EXPECTED ALONG RAILROAD CREEK...INCLUDING THE 
PORTION OF THE CREEK THAT FLOWS THROUGH ANDOVER POND AND THE VILLAGE 
OF ANDOVER.

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.

&&

LAT...LON 4219 7797 4227 7774 4211 7774 4207 7795

$$

HITCHCOCK

2 follow-up statements

000 
WGUS71 KBUF 122139
FFSBUF

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

NYC003-122300-
/O.CON.KBUF.FF.W.0026.000000T0000Z-090812T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALLEGANY NY-
539 PM EDT WED AUG 12 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 PM EDT FOR EAST
CENTRAL ALLEGANY COUNTY...

AT 536 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT THE THUNDERSTORMS WHICH CAUSED THE FLASH FLOODING IN THE AREA 
HAVE DISSIPATED. HOWEVER...FLOODING IS STILL OCCURRING DUE TO THE 
EXCESSIVE RUNOFF OVER SOME AREAS...PARTICULARLY NEAR ROUTE 21 JUST 
NORTH OF ANDOVER...SO THE WARNING WILL BE CONTINUED UNTIL 7 PM.

&&

LAT...LON 4219 7797 4227 7774 4211 7774 4207 7795

$$

SFM

000 
WGUS71 KBUF 122251
FFSBUF

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

NYC003-122300-
/O.CAN.KBUF.FF.W.0026.000000T0000Z-090812T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALLEGANY NY-
651 PM EDT WED AUG 12 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL
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 4219 7797 4227 7774 4211 7774 4207 7795

$$

JJR

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 8:02 PM EDT	Special Marine Warning	BUF		88 min
Aug 12, 2:03 PM EDT	Areal Flood Advisory	BUF	Wyoming	3 hr
Aug 12, 3:29 PM EDT	Flash Flood Warning	BUF	Livingston	98 min
Aug 12, 4:23 PM EDT	Flash Flood Warning	BUF	Allegany	3 hr
Aug 12, 4:34 PM EDT	Flash Flood Warning	BUF	Cattaraugus	3 hr
Aug 12, 5:30 PM EDT	Flash Flood Warning	BUF	Ontario	3 hr

Nearby

Flash Flood Warnings in New York, 2009 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.