EF1 tornado in Lewis County, New York

EF-1 tornado with maximum wind speeds in the range of 95 to 105 mph. The damage occurred right around 2 pm local time across almost a 3/4 mile stretch of Swiss Road midway between Castorland and Croghan. The track of the tornado almost paralleled the road in this stretch, but did cross at some point as it traveled in a SSE direction. Convergent damage was noted along several points, as well as a generally chaotic nature to tree damage near Widmeyer Creek.

On June 30, 2026, an oppressive tropical airmass fueled by extreme heat warnings collided with a sharp mid-level shortwave across the NWS Buffalo CWA, prompting the Storm Prediction Center to issue a Severe Thunderstorm Watch as strong boundary-layer destabilization produced widespread severe convection across Central New York and the North Country. NWS Buffalo Area Forecast Discussions highlighted surging moisture and extreme instability that unleashed powerful multi-cell clusters and isolated supercells, leading to severe straight-line microbursts with winds up to 100 mph and an EF-1 tornado touchdown in Lewis County. Concurrently, deep warm-cloud processes and precipitable water levels approaching 2.0 inches fueled torrential precipitation efficiency, driving Weather Prediction Center Excessive Rainfall concerns for localized flash flooding in poor-drainage areas. As the pre-frontal convective line swept east toward nightfall, loss of daytime heating and post-frontal drying rapidly stabilized the region, bringing an end to the severe weather threat into the overnight hours.