A mesoscale convective vortex pulled a pair of fronts across the area during the afternoon and evening near the time of peak heating. Due to cloud cover ahead of the MCV, instability was not very strong, however shear was impressive. Helicity values were impressive, and the presence of the MCV likely added to it locally over the western Southern Tier. Precipitable water values were between 1.75 and 2 inches, which resulted in torrential rainfall in concert with severe thunderstorm development.

Flash Flood in CATTARAUGUS, NEW YORK
From 16-JUL-20 18:17:00 to 16-JUL-20 20:00:00 (EST-5)
Location: LITTLE VLY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Route 242 at Dutch Hill Road closed due to flooding.

Flash Flood in CHAUTAUQUA, NEW YORK
From 16-JUL-20 18:22:00 to 16-JUL-20 20:00:00 (EST-5)
Location: ELLINGTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Route 62 was closed between Brainerd Road and South Hill Road.

Flash Flood in CATTARAUGUS, NEW YORK
From 16-JUL-20 19:30:00 to 16-JUL-20 20:00:00 (EST-5)
Location: CONEWANGO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Route 62 was closed in Conewango due to flooding.

Flash Flood in CATTARAUGUS, NEW YORK
From 16-JUL-20 19:30:00 to 16-JUL-20 20:00:00 (EST-5)
Location: NEW ALBION
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Mosher Hollow Road was closed due to flooding.

Flood in ERIE, NEW YORK
From 16-JUL-20 17:23:00 to 16-JUL-20 18:23:00 (EST-5)
Location: SOUTH NEWSTEAD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

South Newstead Road was closed due to flooding in the town of Newstead.

Tornado in ERIE, NEW YORK
From 16-JUL-20 15:15:00 to 16-JUL-20 15:16:00 (EST-5)
Location: BRANT
Tornado F-scale: EF0
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Social Media

Video of a tornado on the ground on the Seneca Nation was relayed to the National Weather Service via Twitter near Milestrip Road and Hammond Road. This was verified via a subsequent drone overfly. No structures were affected, and only a few trees were downed.

Tornado in CHAUTAUQUA, NEW YORK
From 16-JUL-20 15:50:00 to 16-JUL-20 15:52:00 (EST-5)
Location: WEST PORTLAND
Tornado F-scale: EF1
Property damage: 150.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A National Weather Service storm survey confirmed EF-1 damage with 100 mph maximum wind estimate, a path length of 1.5 miles, and a width of 35 yards. The tornado touched down in a wooded area before moving across a property, flattening a 60'x80' garage and lifting and rotating a 53' semi trailer. It then crossed a road and damaged the second story of a barn. It crossed another road and damaged two other barns  along Thayer Road before continuing to tree damage to the east end of Farr Road.

Thunderstorm Wind in MONROE, NEW YORK
From 16-JUL-20 11:41:00 to 16-JUL-20 11:41:00 (EST-5)
Location: ADAMS BASIN
Magnitude: 51.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Multiple trees and wires were reported down on East Avenue.

Thunderstorm Wind in CHAUTAUQUA, NEW YORK
From 16-JUL-20 15:16:00 to 16-JUL-20 15:16:00 (EST-5)
Location: IRVING
Magnitude: 51.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Social Media

Multiple trees were reported down.

Thunderstorm Wind in CHAUTAUQUA, NEW YORK
From 16-JUL-20 15:50:00 to 16-JUL-20 15:50:00 (EST-5)
Location: WEST PORTLAND
Magnitude: 87.00 EG
Property damage: 150.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A barn was destroyed, trees were uprooted, and there was additional damage to a house and shop.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 16-JUL-20 16:25:00 to 16-JUL-20 16:25:00 (EST-5)
Location: GOWANDA
Magnitude: 51.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and wires were reported down.

Thunderstorm Wind in ERIE, NEW YORK
From 16-JUL-20 16:58:00 to 16-JUL-20 16:58:00 (EST-5)
Location: BOSTON
Magnitude: 51.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and wires down on Boston State Road.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 16-JUL-20 17:50:00 to 16-JUL-20 17:50:00 (EST-5)
Location: LITTLE VLY
Magnitude: 51.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and wires were reported down.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 16-JUL-20 18:26:00 to 16-JUL-20 18:26:00 (EST-5)
Location: EAST RANDOLPH
Magnitude: 51.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Trees and wires were reported down on Route 242.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 16-JUL-20 18:28:00 to 16-JUL-20 18:28:00 (EST-5)
Location: RANDOLPH
Magnitude: 51.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A porch was blown off a house.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 16-JUL-20 18:30:00 to 16-JUL-20 18:30:00 (EST-5)
Location: NAPOLI
Magnitude: 51.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A tree was reported downed onto a house.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 16-JUL-20 18:50:00 to 16-JUL-20 18:50:00 (EST-5)
Location: ALLEGANY
Magnitude: 51.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and wires were reported down.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 16-JUL-20 18:53:00 to 16-JUL-20 18:53:00 (EST-5)
Location: SALAMANCA
Magnitude: 51.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and wires were reported down.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 16-JUL-20 19:01:00 to 16-JUL-20 19:01:00 (EST-5)
Location: HINSDALE
Magnitude: 51.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and wires were reported down.