A potent shortwave trough was moving from the eastern Great Lakes towards upstate New York during the afternoon on Thursday, May 22nd.  A complex frontal system was moving from west to east during the mid afternoon hours, with the triple point of where the occluded, cold and warm fronts meet situated over the Mohawk Valley.  There was a significant gradient along the warm front, between warm and unstable air over the Mohawk Valley and cooler, more stable air over far eastern New York that originated off the western Atlantic Ocean.
As a result, a large supercell thunderstorm developed along this boundary over the southern Adirondacks and eastern Mohawk Valley and it quickly strengthened.  It produced very large hail as large as 4 inches in diameter in the Amsterdam area.  As this storm continued to strengthen even further, it moved south to southeast towards the Helderbergs and western parts of the Capital Region, where it produced a tornado.  The tornado was on the ground for 7 miles and reached EF3 strength with maximum winds of 140 MPH, as it passed through the town of Duanesburg. The tornado dissipated once it reached western Albany County, and the more stable air in place allowed thunderstorms to weaken as they reached the Hudson Valley. Aside from one additional report of large hail in the mid-Hudson valley, no other thunderstorms reached severe levels and the threat for storms diminished by the evening with passage of the occluded boundary.

Hail in MONTGOMERY, NEW YORK
From 22-MAY-14 14:05:00 to 22-MAY-14 14:20:00 (EST-5)
Location: AMSTERDAM
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A member of the public reported baseball size hail falling on Frederick Street in Amsterdam during a thunderstorm.

Hail in MONTGOMERY, NEW YORK
From 22-MAY-14 14:32:00 to 22-MAY-14 14:36:00 (EST-5)
Location: SCOTCH BUSH
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter size hail was reported during a thunderstorm one mile south-southwest of Scotch Bush.

Funnel Cloud in ALBANY, NEW YORK
From 22-MAY-14 15:15:00 to 22-MAY-14 15:15:00 (EST-5)
Location: BERNE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A funnel cloud was reported during a thunderstorm in East Berne via Facebook.

Hail in MONTGOMERY, NEW YORK
From 22-MAY-14 14:05:00 to 22-MAY-14 14:15:00 (EST-5)
Location: HAGAMAN
Magnitude: 1.00 
Reported by: Public

Quarter size hail was reported by a student at Amsterdam High School in Amsterdam during a thunderstorm.

Hail in MONTGOMERY, NEW YORK
From 22-MAY-14 14:05:00 to 22-MAY-14 14:10:00 (EST-5)
Location: FT JOHNSON
Magnitude: 1.75 
Reported by: Trained Spotter

A trained spotter reported golf ball sized hail occurring during a thunderstorm in Fort Johnson.

Hail in FULTON, NEW YORK
From 22-MAY-14 13:55:00 to 22-MAY-14 14:10:00 (EST-5)
Location: HILL CORNERS
Magnitude: 2.75 
Reported by: Trained Spotter

A trained spotter reported baseball size hail falling during a thunderstorm two miles south of Perth.

Hail in MONTGOMERY, NEW YORK
From 22-MAY-14 14:05:00 to 22-MAY-14 14:20:00 (EST-5)
Location: AMSTERDAM
Magnitude: 1.00 
Reported by: Social Media

Quarter sized hail was reported during a thunderstorm on Julia Street in Amsterdam by a member of the public on Facebook.

Hail in FULTON, NEW YORK
From 22-MAY-14 13:35:00 to 22-MAY-14 13:50:00 (EST-5)
Location: BROADALBIN
Magnitude: 2.00 
Reported by: NWS Employee

Both trained spotters and an NWS employee reported hail measuring up to two inches in diameter occurring in Broadalbin during a thunderstorm.  Video footage showed golf ball sized hail impacting cars on State Route 29.  Hail lasted up to fifteen minutes in duration.

Hail in FULTON, NEW YORK
From 22-MAY-14 13:50:00 to 22-MAY-14 14:05:00 (EST-5)
Location: PERTH
Magnitude: 2.25 
Reported by: Public

Several members of the public reported hail measuring as large as 2.25 inches in diameter in Perth during a thunderstorm.

Hail in MONTGOMERY, NEW YORK
From 22-MAY-14 14:05:00 to 22-MAY-14 14:20:00 (EST-5)
Location: AMSTERDAM
Magnitude: 4.00 
Reported by: Trained Spotter

A trained spotter reported hail measuring 4 inches in diameter during a thunderstorm in Amsterdam. Photos confirmed the size of the hailstones.

Hail in MONTGOMERY, NEW YORK
From 22-MAY-14 14:00:00 to 22-MAY-14 14:10:00 (EST-5)
Location: HAGAMAN
Magnitude: 1.00 
Reported by: Social Media

A member of the public reported via Facebook quarter size hail falling in Hagaman during a thunderstorm.

Thunderstorm Wind in ALBANY, NEW YORK
From 22-MAY-14 15:00:00 to 22-MAY-14 15:00:00 (EST-5)
Location: ALTAMONT
Magnitude: 50.00 EG
Reported by: Trained Spotter

A home was damaged and a barn collapsed as a result of thunderstorm wind damage near Altamont.

Tornado in SCHENECTADY, NEW YORK
From 22-MAY-14 14:33:00 to 22-MAY-14 14:54:00 (EST-5)
Location: BRAMAN CORNERS
Tornado F-scale: EF3
Reported by: NWS Storm Survey

A severe thunderstorm produced a tornado near the intersection of State Route 30 and Churches Road in Duanesburg, producing damage to trees. The tornado continued in a south-southeast direction and caused damage to a roof at the corner of Hardin and Knight Roads in Duanesburg.  At the corner of Hardin and Gross Roads, several trees were sheared off.
The tornado strengthened as it reached 1885 Mudge Road in Duanesburg.  It caused damage to the roof of a home, where debris was wedged under the eaves of the house.  Numerous trees were downed at this location as well.  As the storm continued to near Old Dane Road, numerous trees were downed as well.
The tornado reached it's maximum strength at the intersection of US Route 20 and Mudge Road.  A well-built house (one story ranch) built in 1973 was nearly destroyed, with most of the walls gone.  The tornado was determined to be an EF3 strength at this point with maximum winds of 140 MPH.  A tractor trailed was also blown over on Route 20 as a result of the tornado winds as well.
On nearby Cole Road, the tornado caused damage to an Ambulance Garage with damage to the roof and doors.  A side wall of the building was completely blown out and a dumpster was tossed. Another house on Cole Road had siding shingles ripped off and windows blown out of the house as well.  Numerous trees and power lines were downed as well.
The tornado crossed Interstate 88 in Princetown.  Strong winds associated with the tornado caused two tractor trailer trucks to flip over on the highway.  Trees along the highway were sheared off as well.
The tornado continued south and affected homes in Delanson.  Shingles were blown off a house and damaged a greenhouse at 4155 Schoharie Turnpike and another home at Crow Hill Road had damage to siding and a garage, which was lifted off its foundation and collapsed.
The tornado weakened, but continued to move south towards the Albany County line.

Tornado in ALBANY, NEW YORK
From 22-MAY-14 14:54:00 to 22-MAY-14 14:55:00 (EST-5)
Location: KNOX
Tornado F-scale: EF1
Reported by: NWS Storm Survey

A tornado continued into northwestern Albany County after a long path across Schenectady County.  The tornado produced damage to trees and a roof on Bozenkill Road before dissipating. Although the entire path of the tornado was nearly 7 miles, it was only on the ground in Albany County for about a half of a mile.

Thunderstorm Wind in ALBANY, NEW YORK
From 22-MAY-14 14:55:00 to 22-MAY-14 14:55:00 (EST-5)
Location: ALTAMONT
Magnitude: 50.00 EG
Reported by: Trained Spotter

Windows were blown out of a house near Altamont as a result of thunderstorm wind damage.

Hail in SCHENECTADY, NEW YORK
From 22-MAY-14 15:00:00 to 22-MAY-14 15:05:00 (EST-5)
Location: DUANESBURG
Magnitude: 3.00 
Reported by: Trained Spotter

Large apple size hail was reported during a thunderstorm in Duanesburg.

Hail in ALBANY, NEW YORK
From 22-MAY-14 14:57:00 to 22-MAY-14 15:10:00 (EST-5)
Location: ALTAMONT
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter size hail was reported during a thunderstorm in the town of Knox on Bozenkill Road.

Hail in ULSTER, NEW YORK
From 22-MAY-14 15:52:00 to 22-MAY-14 15:55:00 (EST-5)
Location: NEW PALTZ
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter size hail was reported during a thunderstorm in New Paltz by a trained spotter on the campus of the State University of New York at New Paltz.

Hail in MONTGOMERY, NEW YORK
From 22-MAY-14 14:10:00 to 22-MAY-14 14:20:00 (EST-5)
Location: SOUTH AMSTERDAM
Magnitude: 1.50 
Reported by: Social Media

A member of the public reported via Facebook ping pong ball sized hail during a thunderstorm in the Town of Florida, one mile south of Amsterdam.