A hot and humid airmass was in place across the region with temperatures in the 90s and dew points in the 60s and 70s.  This resulted in heat index values reaching 100 to 110 degrees during the afternoon hours in valley areas.
This hot and humid air mass also provided an unstable environment for strong to severe thunderstorms to form ahead of a cold front passage during the afternoon and evening hours of June 18th. The storms caused numerous trees and power lines to be knocked down, resulting in over 10,000 customers without power. A vacant historic building in Poughkeepsie, New York partially collapsed onto an occupied building, trapping and injuring one woman.

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-JUN-18 15:04:00 to 18-JUN-18 15:04:00 (EST-5)
Location: GRAFTON
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees and wires were downed.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-JUN-18 15:04:00 to 18-JUN-18 15:04:00 (EST-5)
Location: SARATOGA LAKE
Magnitude: 50.00 EG
Reported by: NWS Employee

Trees were snapped and uprooted along Route 50.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-JUN-18 15:05:00 to 18-JUN-18 15:05:00 (EST-5)
Location: GREENWICH
Magnitude: 50.00 EG
Reported by: COOP Observer

Widespread trees and wires were downed.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-JUN-18 15:06:00 to 18-JUN-18 15:06:00 (EST-5)
Location: HILLS TERRACE
Magnitude: 50.00 EG
Reported by: 911 Call Center

Many trees were downed.

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-JUN-18 15:06:00 to 18-JUN-18 15:06:00 (EST-5)
Location: HOOSICK FALLS
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees were downed.

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-JUN-18 15:06:00 to 18-JUN-18 15:06:00 (EST-5)
Location: NORTH HOOSICK
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees and wires were downed.

Thunderstorm Wind in RENSSELAER, NEW YORK
From 18-JUN-18 15:07:00 to 18-JUN-18 15:07:00 (EST-5)
Location: NORTH HOOSICK
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees were downed.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-JUN-18 15:07:00 to 18-JUN-18 15:07:00 (EST-5)
Location: CAMBRIDGE
Magnitude: 50.00 EG
Reported by: Emergency Manager

Trees and wires were downed on North Union Street.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-JUN-18 15:09:00 to 18-JUN-18 15:09:00 (EST-5)
Location: ARGYLE
Magnitude: 50.00 EG
Reported by: Emergency Manager

Tree and wires downed onto a vehicle on West Road.

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

Several large tree limbs were downed.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-JUN-18 15:13:00 to 18-JUN-18 15:13:00 (EST-5)
Location: COSSAYUNA
Magnitude: 50.00 EG
Reported by: Emergency Manager

Trees were downed on East Lake Road.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-JUN-18 15:15:00 to 18-JUN-18 15:15:00 (EST-5)
Location: HILLS TERRACE
Magnitude: 50.00 EG
Reported by: Trained Spotter

Tree limbs were downed. A very large branch that broke off fell onto power lines.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-JUN-18 15:15:00 to 18-JUN-18 15:15:00 (EST-5)
Location: SPACKENKILL
Magnitude: 50.00 EG
Reported by: Trained Spotter

Uprooted trees and large branches were downed.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-JUN-18 15:16:00 to 18-JUN-18 15:16:00 (EST-5)
Location: SPRAGUETOWN
Magnitude: 50.00 EG
Reported by: Fire Department/Rescue

Multiple wires, poles and trees were downed on County Route 113 and County Route 70 in the town of Greenwich.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-JUN-18 15:16:00 to 18-JUN-18 15:16:00 (EST-5)
Location: WEST HEBRON
Magnitude: 50.00 EG
Reported by: Emergency Manager

A tree was downed onto a residence on Patterson Hill Road.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-JUN-18 15:20:00 to 18-JUN-18 15:20:00 (EST-5)
Location: NORTHUMBERLAND
Magnitude: 50.00 EG
Reported by: Department of Highways

Route 4 at Starks Knob Road in the town of Northumberland was closed in both directions due to downed trees.

Heat in SOUTHERN HERKIMER, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Official NWS Observations

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-JUN-18 15:20:00 to 18-JUN-18 15:20:00 (EST-5)
Location: CHAMBERLAIN MILLS
Magnitude: 50.00 EG
Reported by: Emergency Manager

Tree was downed onto wires along Chamberlin Mills Road.

Thunderstorm Wind in WASHINGTON, NEW YORK
From 18-JUN-18 15:38:00 to 18-JUN-18 15:38:00 (EST-5)
Location: SPRAGUETOWN
Magnitude: 50.00 EG
Reported by: Department of Highways

Route 40 at Cottrell Road in the town of Greenwich was closed in both directions due to a downed tree.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-JUN-18 18:00:00 to 18-JUN-18 18:00:00 (EST-5)
Location: MATTEAWAN
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees and wires were downed.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-JUN-18 18:00:00 to 18-JUN-18 18:00:00 (EST-5)
Location: BRINCKERHOFF
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees and wires were downed.

Heat in SOUTHERN FULTON, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in MONTGOMERY, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in NORTHERN WASHINGTON, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in SOUTHERN WASHINGTON, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-JUN-18 18:00:00 to 18-JUN-18 18:00:00 (EST-5)
Location: WAPPINGERS FALLS
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees and wires were downed.

Strong Wind in SOUTHERN HERKIMER, NEW YORK
From 18-JUN-18 13:39:00 to 18-JUN-18 13:39:00 (EST-5)
Magnitude: 47.00 MG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Mesonet

The New York State Mesonet site located near the town of Herkimer recorded a wind gust of 54 mph.

Heat in SOUTHEAST WARREN, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in SOUTHERN SARATOGA, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in NORTHERN SARATOGA, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in EASTERN SCHENECTADY, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in WESTERN SCHENECTADY, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in WESTERN RENSSELAER, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in EASTERN RENSSELAER, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in EASTERN COLUMBIA, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in WESTERN COLUMBIA, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in EASTERN ALBANY, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in EASTERN GREENE, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in EASTERN ULSTER, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in WESTERN DUTCHESS, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in EASTERN DUTCHESS, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Heat in WESTERN ULSTER, NEW YORK
From 18-JUN-18 11:00:00 to 18-JUN-18 19:00:00 (EST-5)
Reported by: Mesonet

Thunderstorm Wind in HERKIMER, NEW YORK
From 18-JUN-18 13:26:00 to 18-JUN-18 13:26:00 (EST-5)
Location: JOHNSON CORNERS
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees were downed.

Thunderstorm Wind in HERKIMER, NEW YORK
From 18-JUN-18 13:39:00 to 18-JUN-18 13:39:00 (EST-5)
Location: DAYS ROCK
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees were downed.

Thunderstorm Wind in HERKIMER, NEW YORK
From 18-JUN-18 13:44:00 to 18-JUN-18 13:44:00 (EST-5)
Location: BURRELL CORNERS
Magnitude: 50.00 EG
Reported by: 911 Call Center

Trees were downed.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-JUN-18 14:20:00 to 18-JUN-18 14:20:00 (EST-5)
Location: CHARLTON
Magnitude: 50.00 EG
Reported by: NWS Employee

Wires were downed on Jockey Street near Charlton Road.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-JUN-18 14:39:00 to 18-JUN-18 14:39:00 (EST-5)
Location: MIDDLE GROVE
Magnitude: 50.00 EG
Reported by: NWS Employee

Trees and wires downed at 16 Young Road.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-JUN-18 14:52:00 to 18-JUN-18 14:52:00 (EST-5)
Location: BACON HILL
Magnitude: 50.00 EG
Reported by: NWS Employee

A tree was downed onto wires north of Dunkin Road.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-JUN-18 14:55:00 to 18-JUN-18 14:55:00 (EST-5)
Location: SARATOGA SPGS
Magnitude: 50.00 EG
Reported by: Trained Spotter

A large tree was downed blocking Hamilton Street.

Thunderstorm Wind in SARATOGA, NEW YORK
From 18-JUN-18 15:00:00 to 18-JUN-18 15:00:00 (EST-5)
Location: SCHUYLERVILLE
Magnitude: 50.00 EG
Reported by: Trained Spotter

One tree was downed along Route 29.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 18-JUN-18 15:04:00 to 18-JUN-18 15:04:00 (EST-5)
Location: SPACKENKILL
Magnitude: 50.00 EG
Reported by: State Official

One person was trapped and injured as a vacant building collapsed onto an occupied building.