May 18 was the second straight day of widespread 90 degree weather across eastern New York. The hot airmass, despite not being overly humid, provided an unstable environment conducive for thunderstorm development.  Thunderstorms began to form in the early afternoon over western New York along a lake breeze boundary.  These storms pushed into the Mohawk Valley by mid-afternoon.  The storms were isolated with large hail initially, but a stronger cluster of storms approached from the west after 6 pm.  The main hazard with these storms was wind damage as they moved from the Mohawk Valley through the Capital District and into the Lake George Saratoga region by the evening hours.  Numerous reports of downed trees and powerlines occurred in this area.  The worst damage occurred from Queensbury in Warren County to Kingsbury in Washington County.  These storms produced a macroburst, or concentrated area of straight line wind damage.  These winds were measured at 68 mph at the Glens Falls New York State Mesonet site, and were estimated to be as high as 90 mph, resulting in widespread tree damage, destroying a barn, and damaging the roofs of a couple of other buildings.  Another cluster of storms resulted in wind damage over portions of Dutchess County toward midnight.

Lightning in ALBANY, NEW YORK
From 18-MAY-17 19:45:00 to 18-MAY-17 19:45:00 (EST-5)
Location: SLINGERLANDS
Property damage: 30.00K
Reported by: Newspaper

A house was damaged when it was struck by lightning and caught fire. The home's roof collapsed and the third floor was damaged by fire. The first and second floors had extensive water damage.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-MAY-17 22:50:00 to 18-MAY-17 22:50:00 (EST-5)
Location: ONIONTOWN
Magnitude: 50.00 EG
Reported by: Emergency Manager

Trees and wires were downed on Old Route 22.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-MAY-17 18:35:00 to 18-MAY-17 18:40:00 (EST-5)
Location: VAUGHNS CORNERS
Magnitude: 78.00 EG
Reported by: Emergency Manager

The National Weather Service confirmed a macroburst (straight line wind damage) from Queensbury in Warren County to Kingsbury in Washington County. Confirmation was based on maps and pictures provided by Washington County Emergency Management, newspaper photos, storm damage reports from Warren County Emergency Management and trained spotter reports.
Winds from the macroburst brought down hundreds of trees, flattened a barn and threw its roof a quarter mile, and tore part of a roof off a building. Power outages, damage to homes from falling trees, and road closures were widespread in this area. The worst part of the damage swath passed just north of the Glens Falls New York State Mesonet observation site, which recorded a gust of 68 mph.

Thunderstorm Wind in WARREN, NEW YORK
From 18-MAY-17 18:30:00 to 18-MAY-17 18:35:00 (EST-5)
Location: (GFL)GLENS FALLS ARP
Magnitude: 78.00 EG
Reported by: Emergency Manager

The National Weather Service confirmed a macroburst (straight line wind damage) from Queensbury in Warren County to Kingsbury in Washington County. Confirmation was based on maps and pictures provided by Washington County Emergency Management, newspaper photos, storm damage reports from Warren County Emergency Management and trained spotter reports.
Winds from the macroburst brought down hundreds of trees, flattened a barn and threw its roof a quarter mile, and tore part of a roof off a building. Power outages, damage to homes from falling trees, and road closures were widespread in this area. The worst part of the damage swath passed just north of the Glens Falls New York State Mesonet observation site, which recorded a gust of 68 mph.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-MAY-17 18:52:00 to 18-MAY-17 18:52:00 (EST-5)
Location: SARATOGA SPGS
Magnitude: 50.00 EG
Reported by: Public

Large tree limbs reported down.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-MAY-17 18:52:00 to 18-MAY-17 18:52:00 (EST-5)
Location: CLIFTON PARK
Magnitude: 50.00 EG
Reported by: Trained Spotter

Tree limbs were downed on Route 9.

Thunderstorm Wind in WARREN, NEW YORK
From 18-MAY-17 19:00:00 to 18-MAY-17 19:00:00 (EST-5)
Location: GLENS FALLS
Magnitude: 50.00 EG
Reported by: Trained Spotter

Wires were downed, resulting in a structure fire.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-MAY-17 18:45:00 to 18-MAY-17 18:45:00 (EST-5)
Location: SARATOGA SPGS
Magnitude: 50.00 EG
Reported by: Public

A large oak tree was uprooted.

Hail in MONTGOMERY, NEW YORK
From 18-MAY-17 16:38:00 to 18-MAY-17 16:38:00 (EST-5)
Location: ST JOHNSVILLE
Magnitude: 1.50 
Reported by: Public

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-MAY-17 19:00:00 to 18-MAY-17 19:00:00 (EST-5)
Location: SARATOGA LAKE
Magnitude: 50.00 EG
Reported by: Amateur Radio

Multiple trees were downed, blocking two lanes of Interstate 87.

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-MAY-17 18:57:00 to 18-MAY-17 18:57:00 (EST-5)
Location: ALBIA
Magnitude: 50.00 EG
Reported by: Public

A tree was reported down.

Thunderstorm Wind in MONTGOMERY, NEW YORK
From 18-MAY-17 18:32:00 to 18-MAY-17 18:32:00 (EST-5)
Location: SOUTH AMSTERDAM
Magnitude: 50.00 EG
Reported by: Public

A tree was blown down, blocking the intersection of Verbraska Avenue and Route 5S.

Thunderstorm Wind in MONTGOMERY, NEW YORK
From 18-MAY-17 18:35:00 to 18-MAY-17 18:35:00 (EST-5)
Location: HAGAMAN
Magnitude: 50.00 EG
Reported by: Public

A tree was blown onto a trailer.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-MAY-17 18:35:00 to 18-MAY-17 18:35:00 (EST-5)
Location: HUDSON FALLS
Magnitude: 59.00 MG
Reported by: Mesonet

Gust measured at Glens Falls New York State Mesonet site.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-MAY-17 18:37:00 to 18-MAY-17 18:37:00 (EST-5)
Location: EAST GALWAY
Magnitude: 50.00 EG
Reported by: Trained Spotter

Large tree limbs were reported down.

Thunderstorm Wind in SCHENECTADY, NEW YORK
From 18-MAY-17 18:40:00 to 18-MAY-17 18:40:00 (EST-5)
Location: HAWTHORNE HILL
Magnitude: 50.00 EG
Reported by: Newspaper

A tree was blown onto a house on Pearse Road.

Thunderstorm Wind in SCHENECTADY, NEW YORK
From 18-MAY-17 18:56:00 to 18-MAY-17 18:56:00 (EST-5)
Location: AQUEDUCT
Magnitude: 50.00 EG
Reported by: Public

Trees and wires were downed just west of Balltown Road.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-MAY-17 18:47:00 to 18-MAY-17 18:47:00 (EST-5)
Location: SARATOGA LAKE
Magnitude: 50.00 EG
Reported by: Public

Trees were downed between Lake Lonely and Saratoga Lake.

Hail in FULTON, NEW YORK
From 18-MAY-17 17:02:00 to 18-MAY-17 17:02:00 (EST-5)
Location: BLEECKER
Magnitude: 1.00 
Reported by: Public

Hail in FULTON, NEW YORK
From 18-MAY-17 17:07:00 to 18-MAY-17 17:07:00 (EST-5)
Location: MAYFIELD
Magnitude: 0.88 
Reported by: Public

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-MAY-17 18:45:00 to 18-MAY-17 18:45:00 (EST-5)
Location: SARATOGA LAKE
Magnitude: 50.00 EG
Reported by: Broadcast Media

A tree was downed on an unoccupied van.

Thunderstorm Wind in ALBANY, NEW YORK
From 18-MAY-17 19:25:00 to 18-MAY-17 19:25:00 (EST-5)
Location: NEWTONVILLE
Magnitude: 50.00 EG
Reported by: Trained Spotter

A tree was downed.

Hail in FULTON, NEW YORK
From 18-MAY-17 17:08:00 to 18-MAY-17 17:08:00 (EST-5)
Location: VAIL MILLS
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-MAY-17 18:57:00 to 18-MAY-17 18:57:00 (EST-5)
Location: RENSSELAER
Magnitude: 50.00 EG
Reported by: Public

Trees were reported down.

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-MAY-17 19:13:00 to 18-MAY-17 19:13:00 (EST-5)
Location: NORTH PETERSBURG
Magnitude: 50.00 EG
Reported by: Storm Chaser

Tree limbs were reported down.

Hail in FULTON, NEW YORK
From 18-MAY-17 17:18:00 to 18-MAY-17 17:18:00 (EST-5)
Location: RICEVILLE
Magnitude: 1.25 
Reported by: Trained Spotter

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-MAY-17 22:48:00 to 18-MAY-17 22:48:00 (EST-5)
Location: ONIONTOWN
Magnitude: 50.00 EG
Reported by: State Official

Numerous trees were reported down near Route 22 and East Duncan Hill Road.

Thunderstorm Wind in HERKIMER, NEW YORK
From 18-MAY-17 17:23:00 to 18-MAY-17 17:23:00 (EST-5)
Location: WEST WINFIELD
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees and wires reported down.

Hail in HERKIMER, NEW YORK
From 18-MAY-17 17:33:00 to 18-MAY-17 17:33:00 (EST-5)
Location: EAGLE BAY
Magnitude: 0.88 
Reported by: Public

Thunderstorm Wind in ALBANY, NEW YORK
From 18-MAY-17 18:56:00 to 18-MAY-17 18:56:00 (EST-5)
Location: LATHAM
Magnitude: 50.00 EG
Reported by: Law Enforcement

Numerous trees and wires were downed with power outages reported.

Thunderstorm Wind in COLUMBIA, NEW YORK
From 18-MAY-17 20:10:00 to 18-MAY-17 20:10:00 (EST-5)
Location: COLUMBIAVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Trees were blown onto wires.

Thunderstorm Wind in HERKIMER, NEW YORK
From 18-MAY-17 17:41:00 to 18-MAY-17 17:41:00 (EST-5)
Location: VAN HORNESVILLE
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees and wires reported down.

Thunderstorm Wind in MONTGOMERY, NEW YORK
From 18-MAY-17 18:02:00 to 18-MAY-17 18:02:00 (EST-5)
Location: AMES
Magnitude: 50.00 EG
Reported by: Public

A tree, wires, and transformer were reported down.

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-MAY-17 19:00:00 to 18-MAY-17 19:00:00 (EST-5)
Location: ALBIA
Magnitude: 50.00 EG
Reported by: Public

Trees were downed onto power lines.

Hail in HAMILTON, NEW YORK
From 18-MAY-17 18:09:00 to 18-MAY-17 18:09:00 (EST-5)
Location: INDIAN LAKE
Magnitude: 1.50 
Reported by: Public

Thunderstorm Wind in ALBANY, NEW YORK
From 18-MAY-17 18:52:00 to 18-MAY-17 18:52:00 (EST-5)
Location: COHOES
Magnitude: 50.00 EG
Reported by: Newspaper

A tree was downed onto a house on Mohawk Street.

Hail in HAMILTON, NEW YORK
From 18-MAY-17 18:11:00 to 18-MAY-17 18:11:00 (EST-5)
Location: INDIAN LAKE
Magnitude: 1.00 
Reported by: Trained Spotter

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-MAY-17 19:00:00 to 18-MAY-17 19:00:00 (EST-5)
Location: DEFREESTVILLE
Magnitude: 50.00 EG
Reported by: Newspaper

Trees and wires were downed across Morner Road.

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-MAY-17 19:17:00 to 18-MAY-17 19:17:00 (EST-5)
Location: NORTH HOOSICK
Magnitude: 50.00 EG
Reported by: Fire Department/Rescue

Multiple reports of trees and wires down in the area.