National Weather Service Buffalo, New York

Western New York Weather History

MAY 11



11th-12th…Nearly two weeks of consistent rainfall across the western southern tier caused streams and creeks to reach bankful. In Chautauqua county a few low lying roads were barricaded because of high water. In Cattaraugus county at the Onoville Marina on the Allegheny River, ramps to the docks were under two feet of water. Also in Cattaraugus county, a mud slide occurred on one of the ski slopes at the Holiday Valley Resort Area in Ellicottville.


Strong thunderstorms moved across the Genesee Valley , Western Finger Lakes and eastern Lake Ontario region during the afternoon hours. The thunderstorm winds, estimated to 65 mph, downed trees in Stafford , Spencerport, and Oswego . Power lines were downed in Adams . In Spencerport, a NWS survey determined damage to trees and several structures was consistent with straight line winds. In Ontario , Wayne county, the survey team determined the damage was caused by a weak tornado. The tornado touched down around 3:30 PM EDT . The initial touchdown occurred near the intersection of Willits and Lakeside Roads. Two homes, an automobile and a storage shed suffered damage. The tornado then touched down on Slocum Road where three more homes sustained damage and several large trees were felled. The final touchdown occured on Lake Road where the roof of a shed was torn off, trees were downed and a power pole and transformer were sheared off. The tornado winds were estimated between 75 and 100 mph. The path length was 2.25 miles, but the tornado was not on the ground the entire path length. The path width was 50 yards.