An energetic storm system moved from the Great Lakes across the St. Lawrence Valley into Ontario/Quebec during the afternoon and evening hours of May 4th. Instability was marginal for thunderstorm development during the afternoon and evening hours with thunderstorms ahead of a cold front. However, winds were unseasonably strong in the atmosphere, accounting for some thunderstorms to produce damaging winds and there was some localized damage in non-thunderstorm winds accompanying the arrival of  colder air.

Hail in ST. LAWRENCE, NEW YORK
From 04-MAY-18 15:40:00 to 04-MAY-18 15:40:00 (EST-5)
Location: POTSDAM
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Half dollar sized hail reported.

Thunderstorm Wind in ST. LAWRENCE, NEW YORK
From 04-MAY-18 15:52:00 to 04-MAY-18 15:53:00 (EST-5)
Location: RUSSELL
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

A few trees downed by thunderstorm winds.

Thunderstorm Wind in FRANKLIN, NEW YORK
From 04-MAY-18 16:10:00 to 04-MAY-18 16:11:00 (EST-5)
Location: BRUSHTON
Magnitude: 55.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Trees and utility lines down.

Thunderstorm Wind in FRANKLIN, NEW YORK
From 04-MAY-18 16:20:00 to 04-MAY-18 16:21:00 (EST-5)
Location: MALONE
Magnitude: 55.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Numerous trees and wires downed by thunderstorm winds.

Thunderstorm Wind in CLINTON, NEW YORK
From 04-MAY-18 18:22:00 to 04-MAY-18 18:22:00 (EST-5)
Location: ARNOLD HILL
Magnitude: 50.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Public

Tree and limbs down, including on a parked truck.

Thunderstorm Wind in FRANKLIN, NEW YORK
From 04-MAY-18 16:48:00 to 04-MAY-18 16:50:00 (EST-5)
Location: LAKE CLEAR
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several trees downed by thunderstorm winds.

Thunderstorm Wind in FRANKLIN, NEW YORK
From 04-MAY-18 16:55:00 to 04-MAY-18 16:58:00 (EST-5)
Location: VERMONTVILLE
Magnitude: 55.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Trees and wires downed by thunderstorm winds.

Thunderstorm Wind in FRANKLIN, NEW YORK
From 04-MAY-18 18:00:00 to 04-MAY-18 18:00:00 (EST-5)
Location: DUANE CENTER
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several trees downed by thunderstorms winds.

Thunderstorm Wind in FRANKLIN, NEW YORK
From 04-MAY-18 17:01:00 to 04-MAY-18 17:01:00 (EST-5)
Location: VERMONTVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trees downed by thunderstorm winds.

Hail in ESSEX, NEW YORK
From 04-MAY-18 17:34:00 to 04-MAY-18 17:35:00 (EST-5)
Location: KEESEVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Quarter size diameter hail.

Thunderstorm Wind in ESSEX, NEW YORK
From 04-MAY-18 19:08:00 to 04-MAY-18 19:10:00 (EST-5)
Location: TICONDEROGA
Magnitude: 55.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several trees and utility lines downed by thunderstorm winds.

Thunderstorm Wind in FRANKLIN, NEW YORK
From 04-MAY-18 16:40:00 to 04-MAY-18 16:40:00 (EST-5)
Location: FAUST
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

Large tree and several additional tree limbs downed by thunderstorm winds.