A very warm and humid air mass was in place across eastern New York on Wednesday, September 11th.  With temperatures into the 90s and dewpoints in the 70s, there was a large amount of instability across the region.  A stalled surface frontal boundary remained well north of the region across southern Canada.
As a subtle upper level disturbance moved across Pennsylvania, thunderstorms developed west of the region across central New York and moved eastward into eastern New York for the late afternoon and evening hours.  Some of these thunderstorms produced damaging winds to trees and power lines and large hail.  In addition, these thunderstorms produced a large amount of cloud to ground lightning, which caused damaged to trees and some structures.  A historic church in Ballston Center had a brief fire due to a lightning strike, which damaged the steeple.  Media reported that nearly 20,000 customers lost power as a result of the thunderstorms.
By late in the evening, thunderstorms weakened and moved east of the region, ending the threat for severe weather.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 11-SEP-13 18:10:00 to 11-SEP-13 18:10:00 (EST-5)
Location: HARTFORD
Magnitude: 50.00 EG
Reported by: Newspaper

Trees were reported down in Hartford as a result of thunderstorm winds.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 11-SEP-13 18:15:00 to 11-SEP-13 18:15:00 (EST-5)
Location: GRANVILLE
Magnitude: 50.00 EG
Reported by: Trained Spotter

Several trees were reported down in Granville as a result of thunderstorm winds.  Roads needed to be closed as a result of being blocked from tree damage.

Thunderstorm Wind in SCHOHARIE, NEW YORK
From 11-SEP-13 16:25:00 to 11-SEP-13 16:25:00 (EST-5)
Location: LEESVILLE
Magnitude: 50.00 EG
Reported by: Law Enforcement

Trees were reported down as a result of thunderstorm winds in Sharon Springs.

Thunderstorm Wind in SCHOHARIE, NEW YORK
From 11-SEP-13 16:35:00 to 11-SEP-13 16:35:00 (EST-5)
Location: CARLISLE
Magnitude: 50.00 EG
Reported by: Law Enforcement

Trees were reported down in Carlisle as a result of thunderstorm winds.

Hail in FULTON, NEW YORK
From 11-SEP-13 16:52:00 to 11-SEP-13 16:57:00 (EST-5)
Location: CORK
Magnitude: 1.25 
Reported by: Social Media

A member of the public reported half dollar size hail during a thunderstorm 4 miles south of Caroga Lake via Facebook.

Hail in FULTON, NEW YORK
From 11-SEP-13 17:00:00 to 11-SEP-13 17:05:00 (EST-5)
Location: WEST BUSH
Magnitude: 1.00 
Reported by: COOP Observer

Quarter size hail was reported during a thunderstorm at Peck Lake.  There was enough hail for the ground to be completely covered.

Thunderstorm Wind in FULTON, NEW YORK
From 11-SEP-13 17:00:00 to 11-SEP-13 17:00:00 (EST-5)
Location: WEST BUSH
Magnitude: 50.00 EG
Reported by: COOP Observer

Numerous trees and power poles were knocked over as a result of thunderstorm winds at Peck Lake.

Hail in FULTON, NEW YORK
From 11-SEP-13 17:00:00 to 11-SEP-13 17:03:00 (EST-5)
Location: CAROGA LAKE
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter size hail was reported during a thunderstorm in Caroga Lake.

Thunderstorm Wind in HERKIMER, NEW YORK
From 11-SEP-13 17:00:00 to 11-SEP-13 17:00:00 (EST-5)
Location: POLAND
Magnitude: 50.00 EG
Reported by: Trained Spotter

Trees and wires were downed as a result of thunderstorm winds at the intersection of Routes 8 and 28 in Poland, near the Cold Brook line.

Thunderstorm Wind in GREENE, NEW YORK
From 11-SEP-13 17:10:00 to 11-SEP-13 17:10:00 (EST-5)
Location: PRATTSVILLE
Magnitude: 50.00 EG
Reported by: 911 Call Center

Multiple trees were downed in Prattsville as a result of thunderstorm winds.

Thunderstorm Wind in SARATOGA, NEW YORK
From 11-SEP-13 17:35:00 to 11-SEP-13 17:35:00 (EST-5)
Location: CEDAR BLUFFS
Magnitude: 61.00 MG
Reported by: Trained Spotter

Large trees and a power pole were reported down along Route 9P in Saratoga Lake as a result of thunderstorm winds. The wind was measured at 70 MPH.

Thunderstorm Wind in SARATOGA, NEW YORK
From 11-SEP-13 17:35:00 to 11-SEP-13 17:35:00 (EST-5)
Location: SARATOGA SPGS
Magnitude: 50.00 EG
Reported by: Law Enforcement

Trees were reported down along Union Avenue in Saratoga Springs as a result of thunderstorm winds.

Thunderstorm Wind in WARREN, NEW YORK
From 11-SEP-13 17:55:00 to 11-SEP-13 17:55:00 (EST-5)
Location: FRENCH MTN
Magnitude: 52.00 EG
Reported by: Social Media

A spotter reported via Facebook an estimated thunderstorm wind gust of 60 MPH at the corner of Potter and West Mountain Roads in Queensbury.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 11-SEP-13 18:00:00 to 11-SEP-13 18:00:00 (EST-5)
Location: ARGYLE
Magnitude: 50.00 EG
Reported by: 911 Call Center

Widespread trees and power lines were reported down through Arygle and the surrounding areas as a result of thunderstorm winds.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 11-SEP-13 18:05:00 to 11-SEP-13 18:05:00 (EST-5)
Location: FT ANN
Magnitude: 50.00 EG
Reported by: Newspaper

Trees were reported down in Fort Ann as a result of thunderstorm winds.

Thunderstorm Wind in WARREN, NEW YORK
From 11-SEP-13 17:56:00 to 11-SEP-13 17:56:00 (EST-5)
Location: WEST GLEN FALLS
Magnitude: 50.00 EG
Reported by: Trained Spotter

Trees and branches were reported down on Hidden Hills Drive near Dixon Road in Queensbury as a result of thunderstorm winds.