Alert archive / New York / Flash Flood Warnings in 2015

Flash Flood Warning 4, NWS Buffalo, NY

May 18, 2015Allegany County, Livingston County, Ontario County, New York

NWS Buffalo, NY issued this flash flood warning at May 18, 2015, 8:40 PM EDT for Allegany County, Livingston County, Ontario 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
May 18, 2015, 8:40 PM EDT (00:40 UTC)
Expired
May 18, 2015, 11:45 PM EDT
In force
3 hr
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

Counties Allegany County, NY, Livingston County, NY, Ontario County, NY

The radar

The Buffalo radar (KBUF), 98 km from the middle of the area, began a volume at 00:39 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

TimeReportWhereRemark
May 18, 9:11 PM EDTFLASH FLOOD1 Nw Reed Corners, NYRT 63 FLOODED AT PARKER HILL RD.

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 00:00Z, 0.7 hours before the alert went out and 94 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 00:00Z on 2015-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 113 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, Buffalo Intl Airport, NY at 00:00Z on 2015-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
113 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
1013 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

310 
WGUS51 KBUF 190040
FFWBUF
NYC003-051-069-190345-
/O.NEW.KBUF.FF.W.0004.150519T0040Z-150519T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BUFFALO NY
840 PM EDT MON MAY 18 2015

THE NATIONAL WEATHER SERVICE IN BUFFALO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN ONTARIO COUNTY IN WESTERN NEW YORK...
  SOUTHEASTERN LIVINGSTON COUNTY IN WESTERN NEW YORK...
  NORTHEASTERN ALLEGANY COUNTY IN WESTERN NEW YORK...

* UNTIL 1145 PM EDT
    
* AT 839 PM EDT...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING 
  VERY HEAVY RAIN ACROSS THE WARNED AREA. DUAL POL DOPPLER RADAR 
  INDICATES THAT AN INCH AND A HALF OF RAIN HAS FALLEN IN THE WARNED 
  AREA THROUGH 8:30 PM EDT...WITH AN ADDITIONAL HALF TO ONE INCH OF 
  RAIN POSSIBLE. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

&&

LAT...LON 4243 7793 4270 7793 4274 7734 4267 7737
      4258 7737 4258 7766 4253 7766 4253 7772
      4243 7773

$$

RSH
3 follow-up statements
824 
WGUS71 KBUF 190053
FFSBUF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BUFFALO NY
853 PM EDT MON MAY 18 2015

NYC003-051-069-190345-
/O.CON.KBUF.FF.W.0004.000000T0000Z-150519T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ONTARIO NY-LIVINGSTON NY-ALLEGANY NY-
853 PM EDT MON MAY 18 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1145 PM EDT FOR
SOUTHWESTERN ONTARIO...SOUTHEASTERN LIVINGSTON AND NORTHEASTERN
ALLEGANY COUNTIES...

AT 851 PM EDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING 
HEAVY RAIN ACROSS THE WARNED AREA. DUAL POL DOPPLER RADAR INDICATES 
THAT OVER AN INCH AND A HALF OF RAIN HAS ALREADY FALLEN OVER THIS 
AREA...AND ANOTHER HALF TO ONE INCH OF RAIN IS EXPECTED. FLASH 
FLOODING IS EXPECTED TO BEGIN SHORTLY.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
DANSVILLE...LETCHWORTH STATE PARK...NAPLES...GROVELAND...
SPRINGWATER...NUNDA...OSSIAN AND CANASERAGA.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...BRADNER CREEK... 
STONY BROOK...ALLENS CREEK...HEMLOCK OUTLET...SLADER CREEK...FRY 
CREEK...NEWVILLE CREEK...SPRINGWATER CREEK...BENNETT CREEK...TWO 
MILE CREEK...CONESUS CREEK...BUCK RUN CREEK...MUD CREEK...CANASERAGA 
CREEK...CANADICE OUTLET...HONEOYE CREEK...KESHEQUA CREEK...BLACK 
CREEK...MILL CREEK... LITTLE MILL CREEK AND SUGAR CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

&&

LAT...LON 4243 7793 4270 7793 4274 7734 4267 7737
      4258 7737 4258 7766 4253 7766 4253 7772
      4243 7773

$$

RSH
785 
WGUS71 KBUF 190204
FFSBUF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BUFFALO NY
1004 PM EDT MON MAY 18 2015

NYC003-051-069-190345-
/O.CON.KBUF.FF.W.0004.000000T0000Z-150519T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ONTARIO NY-LIVINGSTON NY-ALLEGANY NY-
1004 PM EDT MON MAY 18 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1145 PM EDT FOR
SOUTHWESTERN ONTARIO...SOUTHEASTERN LIVINGSTON AND NORTHEASTERN
ALLEGANY COUNTIES...

AT 1000 PM EDT...DUAL POL DOPPLER RADAR INDICATED THAT THE LINE OF 
THUNDERSTORMS AND SLOW MOVING DOWNPOURS HAVE PUSHED EAST AWAY FROM 
THE AREA. WHILE THE STORMS HAVE MOVED AWAY...THERE WILL STILL BE 
HIGH AND FAST RUNNING TRIBUTARIES IN THE AREA.

RADAR ESTIMATED THAT WIDESPREAD ONE TO ONE AND HALF INCH RAINFALL 
AMOUNTS WERE FOUND OVER THE WARNED AREA...WITH SOME SPOTS PICKING UP 
IN EXCESS OF TWO INCHES. ONE THE HARDER HIT AREAS INCLUDED CANASERGA 
CREEK WHERE NEARLY TWO AND A HALF INCHES.

WATER LEVELS IN THE AREA SHOULD BEGIN TO RECEDE AT THIS TIME WITH NO 
ADDITIONAL THUNDERSTORMS EXPECTED OVERNIGHT. 

SOME LOCATIONS THAT COULD STILL EXPERIENCE FLOODING INCLUDE... 
DANSVILLE...LETCHWORTH STATE PARK...NAPLES...GROVELAND... 
SPRINGWATER...NUNDA...OSSIAN AND CANASERAGA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

&&

LAT...LON 4243 7793 4270 7793 4274 7734 4267 7737
      4258 7737 4258 7766 4253 7766 4253 7772
      4243 7773

$$

RSH
511 
WGUS71 KBUF 190337
FFSBUF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BUFFALO NY
1137 PM EDT MON MAY 18 2015

NYC003-051-069-190346-
/O.EXP.KBUF.FF.W.0004.000000T0000Z-150519T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ONTARIO NY-LIVINGSTON NY-ALLEGANY NY-
1137 PM EDT MON MAY 18 2015

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN ONTARIO...SOUTHEASTERN
LIVINGSTON AND NORTHEASTERN ALLEGANY COUNTIES WILL EXPIRE AT 1145 PM
EDT...

FLOOD WATERS HAVE RECEDED...AND ARE NO LONGER EXPECTED TO POSE A
THREAT TO LIFE OR PROPERTY. PLEASE CONTINUE TO HEED ANY ROAD
CLOSURES.

LAT...LON 4243 7793 4270 7793 4274 7734 4267 7737
      4258 7737 4258 7766 4253 7766 4253 7772
      4243 7773

$$

RSH

The office that day

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

IssuedProductOfficeCountiesLasted
May 18, 8:11 PM EDTSevere Thunderstorm WarningBUFAllegany22 min
May 18, 8:27 PM EDTSpecial Weather StatementBUFLivingston33 min
May 18, 9:03 PM EDTFlash Flood WarningBUFOntario3 hr

Nearby

Flash Flood Warnings in New York, 2015Every flash flood warning in 2015

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.