A strong upper level disturbance and surface cold front was located over the Great Lakes during the day on Monday, June 20th.   With a warm and humid air mass in place, thunderstorms developed during the evening hours ahead of the storm system over Lake Ontario and southern Canada and moved towards the region for the late evening hours into the early morning hours on Tuesday, June 21st.  Despite being the overnight hours, these thunderstorms were able to maintain themselves due to very strong winds aloft.
Thunderstorms produced damage to trees and power lines across parts of the Adirondacks, Mohawk Valley and Sacandaga Region before heading eastward towards New England for the late night hours.  As a result of the thunderstorms, over 6,000 people lost power in Fulton and Hamilton Counties.  Numerous power outages were also reported in Saratoga, Albany and Schoharie Counties as well.
The threat for thunderstorms ended around daybreak when the cold front moved across the region from west to east.

Thunderstorm Wind in HERKIMER, NEW YORK
From 20-JUN-16 23:26:00 to 20-JUN-16 23:26:00 (EST-5)
Location: EAST HERKIMER
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees and wires were reported down and blocking State Route 28 in Herkimer.

Thunderstorm Wind in HERKIMER, NEW YORK
From 20-JUN-16 23:30:00 to 20-JUN-16 23:30:00 (EST-5)
Location: SALISBURY
Magnitude: 50.00 EG
Reported by: Trained Spotter

A tree was reported down and blocking State Route 29 in Salisbury due to thunderstorm winds.

Hail in FULTON, NEW YORK
From 21-JUN-16 00:00:00 to 21-JUN-16 00:00:00 (EST-5)
Location: HILL CORNERS
Magnitude: 1.00 
Reported by: Trained Spotter

A trained spotter reported quarter size hail during a thunderstorm in Perth.

Thunderstorm Wind in HERKIMER, NEW YORK
From 20-JUN-16 23:21:00 to 20-JUN-16 23:21:00 (EST-5)
Location: JOHNSON CORNERS
Magnitude: 50.00 EG
Reported by: Fire Department/Rescue

A tree and wires were reported down on Paratore Road near State Route 5 in Frankfort due to thunderstorm winds.

Thunderstorm Wind in HERKIMER, NEW YORK
From 20-JUN-16 23:33:00 to 20-JUN-16 23:33:00 (EST-5)
Location: KELHI CORNERS
Magnitude: 50.00 EG
Reported by: Fire Department/Rescue

Wires were reported down and a power pole was snapped at the base and leaning into wires along State Route 169 in Little Falls.

Thunderstorm Wind in FULTON, NEW YORK
From 20-JUN-16 23:58:00 to 20-JUN-16 23:58:00 (EST-5)
Location: GLOVERSVILLE
Magnitude: 50.00 EG
Reported by: Emergency Manager

A tree was reported down and on a house on Bloomingdale Avenue in Gloversville due to thunderstorm winds.

Thunderstorm Wind in FULTON, NEW YORK
From 21-JUN-16 00:06:00 to 21-JUN-16 00:06:00 (EST-5)
Location: GORTHEY CORNERS
Magnitude: 60.00 EG
Reported by: Emergency Manager

Six structures were damaged due to downed trees from thunderstorm winds in Broadalbin on the shore of Great Sacandaga Lake.  The homes were reported to have sustained moderate damage.

Thunderstorm Wind in FULTON, NEW YORK
From 20-JUN-16 23:58:00 to 20-JUN-16 23:58:00 (EST-5)
Location: GLOVERSVILLE
Magnitude: 50.00 EG
Reported by: Emergency Manager

Trees were reported down at the intersection of Forest Street and Montgomery Street in Gloversville due to thunderstorm winds.

Thunderstorm Wind in SCHOHARIE, NEW YORK
From 21-JUN-16 01:27:00 to 21-JUN-16 01:27:00 (EST-5)
Location: NORTH BLENHEIM
Magnitude: 50.00 EG
Reported by: Emergency Manager

Trees and wires were reported down in North Blenheim due to thunderstorm winds.

Thunderstorm Wind in FULTON, NEW YORK
From 21-JUN-16 00:06:00 to 21-JUN-16 00:06:00 (EST-5)
Location: GORTHEY CORNERS
Magnitude: 60.00 EG
Reported by: Trained Spotter

Several trees were downed at Birch Haven Campground on the eastern shore of Great Sacandaga Lake in Broadalbin.  Campers were not able to enter or exit the campground due to the amount of downed trees.

Thunderstorm Wind in FULTON, NEW YORK
From 20-JUN-16 23:59:00 to 20-JUN-16 23:59:00 (EST-5)
Location: GLOVERSVILLE
Magnitude: 50.00 EG
Reported by: Newspaper

Trees were reported down on Lark Street in Gloversville due to thunderstorm winds.  The road was impassable due to the downed trees.

Thunderstorm Wind in FULTON, NEW YORK
From 21-JUN-16 00:03:00 to 21-JUN-16 00:03:00 (EST-5)
Location: SACANDAGA PARK
Magnitude: 50.00 EG
Reported by: Social Media

A tree was downed and across State Route 30 near County Route 123 in Northville due to thunderstorm winds.

Thunderstorm Wind in HERKIMER, NEW YORK
From 20-JUN-16 23:33:00 to 20-JUN-16 23:33:00 (EST-5)
Location: LITTLE FALLS
Magnitude: 50.00 EG
Reported by: Fire Department/Rescue

Large branches were downed and blocking Salisbury Road in Little Falls due to thunderstorm winds.

Thunderstorm Wind in HERKIMER, NEW YORK
From 20-JUN-16 22:26:00 to 20-JUN-16 22:26:00 (EST-5)
Location: EAGLE BAY
Magnitude: 50.00 EG
Reported by: NWS Employee

A tree was down and on a garage on Fourth Lake near Old Forge due to thunderstorm winds.