Alert archive / New York / Flash Flood Warnings in 2017

Flash Flood Warning 9, NWS Buffalo, NY

August 2, 2017Allegany County, Cattaraugus County, New York

NWS Buffalo, NY issued this flash flood warning at Aug 2, 2017, 5:57 PM EDT for Allegany County, Cattaraugus 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 2, 2017, 5:57 PM EDT (21:57 UTC)
Expired
Aug 2, 2017, 9:00 PM EDT
In force
3 hr
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

Counties Allegany County, NY, Cattaraugus County, NY

The radar

The Buffalo radar (KBUF), 102 km from the middle of the area, began a volume at 22:01 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, 10.0 hours before the alert went out and 99 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 2017-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 37 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 12:00Z on 2017-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -38 square meters per square second.1939Sfc1 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
37 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
1523 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-38 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

503 
WGUS51 KBUF 022157
FFWBUF
NYC003-009-030100-
/O.NEW.KBUF.FF.W.0009.170802T2157Z-170803T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Buffalo NY
557 PM EDT WED AUG 2 2017

The National Weather Service in Buffalo has issued a

* Flash Flood Warning for...
  Southeastern Cattaraugus County in western New York...
  Southwestern Allegany County in western New York...

* Until 900 PM EDT.

* At 556 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to
  begin shortly.

* Some locations that will experience flooding include...
  Olean, Allegany, St. Bonaventure, Weston Mills, Hinsdale,
  Friendship, Bolivar and Portville.

This includes Interstate 86 between exits 25 and 26.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

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.

&&

LAT...LON 4200 7855 4208 7854 4220 7834 4220 7800
      4200 7799

$$

Apffel
2 follow-up statements
500 
WGUS71 KBUF 022323
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
723 PM EDT WED AUG 2 2017

NYC003-009-030100-
/O.CON.KBUF.FF.W.0009.000000T0000Z-170803T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cattaraugus NY-Allegany NY-
723 PM EDT WED AUG 2 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 900 PM EDT FOR
SOUTHEASTERN CATTARAUGUS AND SOUTHWESTERN ALLEGANY COUNTIES...

At 715 PM EDT, Doppler radar indicated heavy thunderstorms have now 
pushed east of the warned area, with lighter showers tapering off 
through 8 pm. Though the heaviest of rain has ended, flash flooding 
in low lying areas is still possible as water runs off the slopes of 
hills.

Some locations that will experience flooding include...
Olean, Allegany, St. Bonaventure, Weston Mills, Hinsdale, Friendship,
Bolivar and Portville.

This includes Interstate 86 between exits 25 and 26.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

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.

&&

LAT...LON 4200 7855 4208 7854 4220 7834 4220 7800
      4200 7799

$$

Thomas
949 
WGUS71 KBUF 030011
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
811 PM EDT WED AUG 2 2017

NYC003-009-030017-
/O.CAN.KBUF.FF.W.0009.000000T0000Z-170803T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cattaraugus NY-Allegany NY-
811 PM EDT WED AUG 2 2017

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN CATTARAUGUS AND
SOUTHWESTERN ALLEGANY COUNTIES IS CANCELLED...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 4200 7855 4208 7854 4220 7834 4220 7800
      4200 7799

$$

Apffel

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 1:37 PM EDTLakeshore Flood WatchBUFCayuga, Jefferson, Monroe, Oswego, Wayne25 hr
Aug 2, 4:10 PM EDTSpecial Weather StatementBUFCattaraugus35 min
Aug 2, 5:29 PM EDTSpecial Weather StatementBUFAllegany31 min
Aug 2, 7:34 PM EDTSpecial Weather StatementBUFOntario41 min

Nearby

Flash Flood Warnings in New York, 2017Every flash flood warning in 2017

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.