FloodZoneMap.org

Flash Flood — Allegany, NY

Sep 21, 2024

Showers moved into the western New York area on the afternoon of Saturday September 21st. With shortwave trough over the area and within a northwest flow regime, along with around 1,500 J/kg of surface based CAPE thunderstorms developed within the showers. With conditions mostly favorable, thunderstorms became strong to severe at times during the afternoon. The thunderstorms caused damaging wind gusts and large hail to the size of golf balls. Heavy rainfall associated with the thunderstorms caus

Source: NOAA National Weather Service Storm Events Database (event 1215856). Narrative written by NWS staff at the time of the event.

Flood Risk Context for Allegany, NY

This event is one of many recorded floods in Allegany County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.

View Allegany County flood data →

More Flood Stories

Flash Flood

Allegany, NY · Jun 12, 2012

A slow moving cold front was crossing the lower Great Lakes late in the afternoon while a moisture rich airmass sat across Western New York. Thunderstorms developed along what appeared to be a lake breeze boundary ahead of the surface cold front.

Read the full account →
Flash Flood$40K damage

Allegany, NY · Jun 9, 2021

A cold front dropped southward across the region and interacted with modestly moist and unstable conditions. A humid boundary layer was in place as evidenced by surface dewpoints in the upper 60s to lower 70s.

Read the full account →
Flash Flood$10K damage

Allegany, NY · Jun 9, 2021

A cold front dropped southward across the region and interacted with modestly moist and unstable conditions. A humid boundary layer was in place as evidenced by surface dewpoints in the upper 60s to lower 70s.

Read the full account →
Flash Flood$250K damage

Allegany, NY · Jul 14, 2015

A persistent area of showers and thunderstorms associated with a nearly stationary warm front intensified during the afternoon hours. The storms brought flooding to areas already hit by heavy rains in the overnight and morning hours in Chautauqua and Cattaraugus Counties as well…

Read the full account →