National Weather Service Buffalo, New York
Western New York Weather History
20th-21st…From two to three inches of rain fell over the upper Genesee River Basin on the 20th. The Genesee River crested at Wellsville at 3.3 feet above flood stage at midnight on the 21st. Downstream at Portageville the river reached its peak at 1.6 feet above flood stage at noon on the 21st. In Allegany county portions of County Routes 46, 29, 38, 10, 12 and 19 had to be closed. Some evacuations took place in Wellsville. In the town of Groveland in Livingston county several roads had to be closed.
From 1.5 to 2.5 inches of rain fell over the upper Allegany River basin. The river reached flood stage at Olean on the evening of the 20th. At Salamanca, the river reached flood stage during the early morning on the 21st. Several state and county roads were reported underwater and closed. The heavy rains caused flooding and evacuations of campers at Allegany State Park.
Thunderstorms developed as an upper level disturbance crossed western New York during the late morning and early afternoon hours. Wind damage was reported in Alden, Erie county. Hail, up to an inch in diameter, fell in Wrights corners, Niagara county, and Naples, Ontario county.
Thunderstorms during the early afternoon hours reached severe limits. The thunderstorm winds downed trees and power lines in Chautauqua and Livingston counties. In Wyoming county, the thunderstorms also produced three-quarter inch hail.
Heavy rain, in excess of five inches, fell in two storms on the city of Jamestown, Chautauqua county, The flood waters inundated downtown streets and parking lots with up to two feet of water.
An isolated thunderstorm crossed Allegany county during the early morning hours. Several trees and power lines fell. One tree tipped over a pop-up camper. The teenage girl sleeping inside suffered minor injuries. Another tree which fell nearby caused structural damage to the wall of a house.
A cold front crossing the area during the afternoon hours triggered thunderstorms across the eastern Finger Lakes and eastern Lake Ontario regions. The thunderstorm winds downed trees and wired in Phelps and Geneva. Hail, up to one inch in diameter, was reported in Penfield, Macedon, Geneva, Honeoye Falls and Henderson.