A weak surface low tracked across western NY to the northeast of Lake Ontario from the afternoon to the late evening hours. Building instability and increased wind shear ahead of the low supported clusters of severe thunderstorms beginning late in the afternoon across the northern Finger Lakes. Additional northward moving severe storms that exhibited low-level rotation formed early in the evening in a narrow corridor from central New York to areas east of Lake Ontario. In addition to wind damage and large hail, two tornadoes occurred over northeast portions of Oswego County and southern portions of Lewis County during the evening. Eventually, storm surveys confirmed that one of these tornadoes near West Leyden New York to Turin New York tracked 16 miles with observed damage indicating peak winds up to of 140 mph or EF-3 strength. After the tornadic storms diminished, additional storms with very heavy rain tracked over portions of Oswego and Lewis counties from late evening into the overnight hours. These storms which trained over similar areas produced 3 to 4 inches of rain with multiple roads flooded and a few roads entirely washed out.

Tornado in LEWIS, NEW YORK
From 07-AUG-23 18:27:00 to 07-AUG-23 18:30:00 (EST-5)
Location: NORTH OSCEOLA
Tornado F-scale: EFU
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

The National Weather Service in Buffalo used Sentinel-2 satellite
imagery and found tornadic damage in Lewis County. A damage scar
was found using difference techniques of satellite imagery. The
scar was found in a wooded area east of North Osceola Road in the
Town of Osceola. A damage survey could not be conducted due to
limited access into the wooded area. The tornado is thus rated
EF-Unknown.

Thunderstorm Wind in OSWEGO, NEW YORK
From 07-AUG-23 17:48:00 to 07-AUG-23 17:48:00 (EST-5)
Location: CONSTANTIA
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires were downed.

Thunderstorm Wind in OSWEGO, NEW YORK
From 07-AUG-23 17:56:00 to 07-AUG-23 17:56:00 (EST-5)
Location: WILLIAMSTOWN
Magnitude: 51.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: NWS Employee

A tree was downed.

Thunderstorm Wind in ONTARIO, NEW YORK
From 07-AUG-23 14:15:00 to 07-AUG-23 14:15:00 (EST-5)
Location: MANCHESTER
Magnitude: 51.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Multiple trees and wires were downed.

Thunderstorm Wind in WAYNE, NEW YORK
From 07-AUG-23 14:24:00 to 07-AUG-23 14:24:00 (EST-5)
Location: MACEDON
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires were downed.

Thunderstorm Wind in OSWEGO, NEW YORK
From 07-AUG-23 17:59:00 to 07-AUG-23 17:59:00 (EST-5)
Location: PARISH
Magnitude: 51.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: NWS Employee

A tree was downed on State Route 69 just to the east of Interstate 81.

Thunderstorm Wind in LEWIS, NEW YORK
From 07-AUG-23 18:28:00 to 07-AUG-23 18:28:00 (EST-5)
Location: NORTH OSCEOLA
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were downed on wires along North Osceola Road.

Thunderstorm Wind in WAYNE, NEW YORK
From 07-AUG-23 14:42:00 to 07-AUG-23 14:42:00 (EST-5)
Location: WILLIAMSON
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires were downed.

Thunderstorm Wind in OSWEGO, NEW YORK
From 07-AUG-23 15:05:00 to 07-AUG-23 15:05:00 (EST-5)
Location: ALBION CENTER
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Wires were downed.

Thunderstorm Wind in LEWIS, NEW YORK
From 07-AUG-23 18:38:00 to 07-AUG-23 18:38:00 (EST-5)
Location: WEST LEYDEN
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Multiple trees were downed.

Flash Flood in OSWEGO, NEW YORK
From 07-AUG-23 22:00:00 to 08-AUG-23 00:00:00 (EST-5)
Location: WILLIAMSTOWN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Road was flooded due to heavy rain.

Thunderstorm Wind in WAYNE, NEW YORK
From 07-AUG-23 16:12:00 to 07-AUG-23 16:12:00 (EST-5)
Location: NEWARK
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires were downed.

Thunderstorm Wind in WAYNE, NEW YORK
From 07-AUG-23 16:12:00 to 07-AUG-23 16:12:00 (EST-5)
Location: MUD MILLS
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires were downed.

Flash Flood in LEWIS, NEW YORK
From 07-AUG-23 23:00:00 to 08-AUG-23 00:10:00 (EST-5)
Location: CONSTABLEVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Parts of Highmarket Road were washed out.

Flash Flood in OSWEGO, NEW YORK
From 07-AUG-23 23:00:00 to 08-AUG-23 00:10:00 (EST-5)
Location: REDFIELD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A culvert was washed out and a road was closed due to flooding.

Thunderstorm Wind in WAYNE, NEW YORK
From 07-AUG-23 16:20:00 to 07-AUG-23 16:20:00 (EST-5)
Location: LYONS
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires were downed.

Thunderstorm Wind in JEFFERSON, NEW YORK
From 07-AUG-23 17:12:00 to 07-AUG-23 17:12:00 (EST-5)
Location: CARTHAGE
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Multiple trees were snapped and felled.

Tornado in LEWIS, NEW YORK
From 07-AUG-23 18:42:00 to 07-AUG-23 19:14:00 (EST-5)
Location: WEST LEYDEN
Tornado F-scale: EF3
Property damage: 1.50M
Crop damage: 0.00K
Reported by: NWS Storm Survey

The National Weather Service in Buffalo completed a storm survey in Lewis County for damage that is confirmed to be tornadic from Monday evening. Initial damage from the tornado occurred in the Town of Lewis to the west of West Leyden along Mud Lake Road that included uprooted and snapped hardwood trees, significant damage to two homes that included roof uplift and near total removal, a wall blowout of a garage, and the complete destruction and shift from the foundation of a barn. Damage in the initial portion of the track generally peaked at EF-2. The tornado then continued northward and crossed Fish Creek Road with damage to another home that removed the roof and caused significant damage in the walls of the second level of the home. It also did significant damage to a second barn and snapped many hardwood trees.
After moving north of Fish Creek Road, the tornado crossed a large swamp with evidence of full defoliation of a few hardwood trees in the swamp. Tornadic damage become less continuous north of this point without good road access to the track through swampy land.  Convergent track damage again resumed well southwest of the Town of Turin, hitting the town water tower. The tornado then continued northward as it paralleled West Road. Continuous uprooting, snapping, and occasional defoliation of hard and softwood trees was evident for a long portion of the track until it reached Snow Ridge Ski Resort. Upon reaching Snow Ridge Ski Resort, tree damage increased to snapping of hardwood trees at the rootline and some defoliation. On the ski resort land, all of the chair lift metal cables failed, some chair lift structures were overturned or damaged, and the track of damage greatly widened as the storm continued north-
northeastward. The greatest damage along the entire track of the tornado was from Snow Ridge Ski Resort to the West Wind Motel in Turin. Several structures saw completed roof failures, interior wall failures, window failures, and a one multi-story building was shifted from its foundation with its entire roof removed. The tornado lifted after affecting the West Wind Motel with damage ceasing from this point as it crossed State Route 26.