Alert archive / New York / Flash Flood Warnings in 2009

Flash Flood Warning 25, NWS Buffalo, NY

August 12, 2009Livingston County, New York

NWS Buffalo, NY issued this flash flood warning at Aug 12, 2009, 3:29 PM EDT for Livingston County, New York. It was in force for 98 min. 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, 3:29 PM EDT (19:29 UTC)
Expired: Aug 12, 2009, 5:07 PM EDT
In force: 98 min
Issued by: NWS Buffalo, NY
Area: Storm-based polygon
Flood severity: None

County Livingston County, NY

The radar

The Buffalo radar (KBUF), 97 km from the middle of the area, began a volume at 19:32 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, 4:15 PM EDT	FLASH FLOOD	Dansville, NY	LARGE AMOUNT OF WATER OVER ROADS AND A NUMBER OF BASEMENTS FLOODED.

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, 7.5 hours before the alert went out and 93 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 121929
FFWBUF
NYC051-122230-
/O.NEW.KBUF.FF.W.0025.090812T1929Z-090812T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN BUFFALO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN LIVINGSTON COUNTY IN WESTERN NEW YORK...
  THIS INCLUDES THE CITY OF DANSVILLE...

* UNTIL 630 PM EDT

* AT 325 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A VERY SLOW MOVING THUNDERSTORM WITH HEAVY RAINFALL NEAR THE CITY  
  OF DANSVILLE. ANOTHER SLOW MOVING THUNDERSTORM WAS LOCATED NEAR    
  SPRINGWATER. DOPPLER RADAR ESTIMATES THAT 2 TO 3 INCHES OF RAIN    
  HAS FALLEN IN THE PAST HOUR. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 
  INCHES ARE POSSIBLE IN SOME AREAS. 

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL RESULT IN RAPID RISES ON 
AREA STREAMS AND CREEKS. FLOODING OF LOW LYING AREAS IS ALSO LIKELY. 
TRIBUTARIES OF CANASERAGA CREEK THAT FLOW THROUGH THE CITY OF 
DANSVILLE ARE LIKELY TO SEE RAPID AND POTENTIALLY DANGEROUS RISES. 
SPRINGWATER CREEK WILL ALSO SEE SIGNIFICANT RISES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

NEVER DRIVE THROUGH FLOODED ROADWAYS...REMEMBER TURN AROUND DONT 
DROWN. NEVER ALLOW CHILDREN TO PLAY IN OR NEAR FLOOD WATERS.

&&

LAT...LON 4248 7783 4263 7778 4267 7766 4268 7751
      4267 7748 4258 7750 4258 7765 4254 7765
      4254 7766 4253 7771 4247 7772

$$

HITCHCOCK

1 follow-up statement

000 
WGUS71 KBUF 122107
FFSBUF

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

NYC051-122117-
/O.CAN.KBUF.FF.W.0025.000000T0000Z-090812T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LIVINGSTON NY-
507 PM EDT WED AUG 12 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHEASTERN
LIVINGSTON COUNTY...

THE HEAVY THUNDERSTORMS WHICH PROMPTED THE FLOODING HAVE MOVED OUT 
OF THE REGION. 

PONDING OF LOW LYING AND POOR DRAINAGE AREAS WILL BE POSSIBLE FOR
AWHILE UNTIL THE WATER HAS TIME TO RUN OFF.

LAT...LON 4248 7783 4263 7778 4267 7766 4268 7751
      4267 7748 4258 7750 4258 7765 4254 7765
      4254 7766 4253 7771 4247 7772

$$

SFM

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, 4:00 PM EDT	Flash Flood Warning	BUF	Allegany	3 hr
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.