A strong shortwave passed to the north of the area late afternoon into early evening. Winds aloft increased considerably ahead of this shortwave, with 850 mb winds of about 40 knots. A warm and moist air mass was in place ahead of this, and even with considerable cloud cover, the air mass destabilized with up to 1000-1500 J/Kg of CAPE. Storms developed ahead of an associated cold front, then weakened as they approached the Lake Erie shadow. There was just enough momentum for strong winds ahead of a storm to push into downtown Buffalo even with rapidly diminishing reflectivity. A line of storms passed north of Lake Ontario, with a broken line south of it. The most impressive line moved across the St. Lawrence Valley, but despite its appearance, winds only mixed to the surface locally aided by mid-level meso-vortices. There were a few severe storms embedded in storms south of Lake Ontario. Some briefly developed impressive reflectivity cores with severe hail and damaging winds.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 13-JUN-18 17:03:00 to 13-JUN-18 17:03:00 (EST-5)
Location: ALLEGANY
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees down.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 13-JUN-18 17:06:00 to 13-JUN-18 17:06:00 (EST-5)
Location: FARMERSVILLE STN
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees down.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 13-JUN-18 17:10:00 to 13-JUN-18 17:10:00 (EST-5)
Location: WESTONS MILLS
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees down.

Thunderstorm Wind in ALLEGANY, NEW YORK
From 13-JUN-18 17:13:00 to 13-JUN-18 17:13:00 (EST-5)
Location: RUSHFORD
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees down on route 23 in Rushford.

Thunderstorm Wind in ALLEGANY, NEW YORK
From 13-JUN-18 17:28:00 to 13-JUN-18 17:28:00 (EST-5)
Location: VASBURG
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Numerous trees and power lines down along California Hollow Road in the town of Boliva.

Thunderstorm Wind in JEFFERSON, NEW YORK
From 13-JUN-18 17:34:00 to 13-JUN-18 17:34:00 (EST-5)
Location: CLAYTON
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires down.

Thunderstorm Wind in JEFFERSON, NEW YORK
From 13-JUN-18 17:37:00 to 13-JUN-18 17:37:00 (EST-5)
Location: CLAYTON CENTER
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Large tree and wires down.

Thunderstorm Wind in JEFFERSON, NEW YORK
From 13-JUN-18 17:37:00 to 13-JUN-18 17:37:00 (EST-5)
Location: CLAYTON CENTER
Magnitude: 50.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Tree down on Wood Road.

Thunderstorm Wind in JEFFERSON, NEW YORK
From 13-JUN-18 17:38:00 to 13-JUN-18 17:38:00 (EST-5)
Location: DEPAUVILLE
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires down.

Thunderstorm Wind in JEFFERSON, NEW YORK
From 13-JUN-18 17:59:00 to 13-JUN-18 17:59:00 (EST-5)
Location: ANTWERP
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires down.

Thunderstorm Wind in LEWIS, NEW YORK
From 13-JUN-18 18:15:00 to 13-JUN-18 18:15:00 (EST-5)
Location: HARRISVILLE
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Several trees down in the town of Diana.

Thunderstorm Wind in LEWIS, NEW YORK
From 13-JUN-18 18:15:00 to 13-JUN-18 18:15:00 (EST-5)
Location: HARRISVILLE
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Several trees down at the intersection of Main Street and Wilder Drive.

Thunderstorm Wind in LEWIS, NEW YORK
From 13-JUN-18 18:15:00 to 13-JUN-18 18:15:00 (EST-5)
Location: HARRISVILLE
Magnitude: 50.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roof blown off building on Hands Flat Road.

Thunderstorm Wind in LEWIS, NEW YORK
From 13-JUN-18 18:46:00 to 13-JUN-18 18:46:00 (EST-5)
Location: BEAVER FALLS
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires reported down.

Thunderstorm Wind in LEWIS, NEW YORK
From 13-JUN-18 19:18:00 to 13-JUN-18 19:18:00 (EST-5)
Location: LYONSDALE
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Multiple reports of trees down along River Road.

Thunderstorm Wind in ERIE, NEW YORK
From 13-JUN-18 15:38:00 to 13-JUN-18 15:38:00 (EST-5)
Location: BUFFALO
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Tree on car near Prospect and Virginia Avenue in Buffalo.

Thunderstorm Wind in ERIE, NEW YORK
From 13-JUN-18 15:42:00 to 13-JUN-18 15:42:00 (EST-5)
Location: HARRIS HILL
Magnitude: 52.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Employee

Several parked tractor trailers tipped over.

Hail in CATTARAUGUS, NEW YORK
From 13-JUN-18 17:02:00 to 13-JUN-18 17:02:00 (EST-5)
Location: MACHIAS
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in CATTARAUGUS, NEW YORK
From 13-JUN-18 17:07:00 to 13-JUN-18 17:07:00 (EST-5)
Location: FARMERSVILLE STN
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Hail in ALLEGANY, NEW YORK
From 13-JUN-18 17:15:00 to 13-JUN-18 17:15:00 (EST-5)
Location: RUSHFORD
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 13-JUN-18 16:51:00 to 13-JUN-18 16:51:00 (EST-5)
Location: CATTARAUGUS
Magnitude: 50.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Public

Tree down on route 353 between 42nd Street and Broadway.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 13-JUN-18 16:55:00 to 13-JUN-18 16:55:00 (EST-5)
Location: WEST VLY
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees reported down.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 13-JUN-18 16:58:00 to 13-JUN-18 16:58:00 (EST-5)
Location: DELEVAN
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Numerous trees reported down.

Thunderstorm Wind in CATTARAUGUS, NEW YORK
From 13-JUN-18 17:02:00 to 13-JUN-18 17:02:00 (EST-5)
Location: MACHIAS
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees down.