Severe thunderstorms impacted portions of the eastern Catskills, Mid-Hudson Valley, and Taconics during the afternoon of May 15th. Several supercell thunderstorms developed, with the lead storm resulting in a EF1 tornado near Saugerties and a swath of hail of two inches diameter and greater. Later in the afternoon, an intense thunderstorm with winds up to 105 mph resulted in a widespread area of wind damage along the I-84 corridor in southern Dutchess County.
Over 35,000 customers in Dutchess and Ulster Counties lost power as a result of the storms. Travel restrictions were issued for southern Dutchess County due to downed trees and malfunctioning traffic lights, and Amtrak and Metro North rail service was suspended in the county. The governor deployed 125 members of the National Guard to aid storm recovery efforts.

Hail in ULSTER, NEW YORK
From 15-MAY-18 13:48:00 to 15-MAY-18 13:48:00 (EST-5)
Location: WOODSTOCK
Magnitude: 1.00 
Reported by: Social Media

Quarter sized hail lasted three to four minutes.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:20:00 to 15-MAY-18 15:20:00 (EST-5)
Location: GLENHAM
Magnitude: 68.00 MG
Reported by: Mesonet

A 78 mph gust was measured at the New York State Mesonet site near Beacon. Its webcam also showed a large tree downed.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:19:00 to 15-MAY-18 15:19:00 (EST-5)
Location: MATTEAWAN
Magnitude: 60.00 EG
Reported by: Public

Large tree limbs and branches were downed in the city of Beacon.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:29:00 to 15-MAY-18 15:29:00 (EST-5)
Location: EAST FISHKILL
Magnitude: 50.00 EG
Reported by: Department of Highways

A tree was downed on the Taconic State Parkway blocking the right northbound lane.

Thunderstorm Wind in ULSTER, NEW YORK
From 15-MAY-18 13:54:00 to 15-MAY-18 13:54:00 (EST-5)
Location: CENTERVILLE
Magnitude: 50.00 EG
Reported by: Department of Highways

A tree and wires were downed on Route 212 at Pine Lane blocking both lanes.

Thunderstorm Wind in COLUMBIA, NEW YORK
From 15-MAY-18 13:41:00 to 15-MAY-18 13:41:00 (EST-5)
Location: GERMANTOWN
Magnitude: 50.00 EG
Reported by: Public

A tree and wires were downed on Viewmont Road in the town of Germantown.

Thunderstorm Wind in COLUMBIA, NEW YORK
From 15-MAY-18 13:46:00 to 15-MAY-18 13:46:00 (EST-5)
Location: SNYDERVILLE
Magnitude: 50.00 EG
Reported by: Broadcast Media

A large tree was downed onto a wire.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:29:00 to 15-MAY-18 15:29:00 (EST-5)
Location: STORMVILLE
Magnitude: 50.00 EG
Reported by: Social Media

A tree was reported down.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:29:00 to 15-MAY-18 15:29:00 (EST-5)
Location: SHENANDOAH
Magnitude: 50.00 EG
Reported by: Social Media

One tree was downed on a car, another tree was downed on a house.

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 13:46:00 to 15-MAY-18 13:46:00 (EST-5)
Location: ELIZAVILLE
Magnitude: 2.00 
Reported by: Social Media

Hail estimated at two inches diameter broke windows in a house.

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 13:43:00 to 15-MAY-18 13:43:00 (EST-5)
Location: CLERMONT
Magnitude: 2.75 
Reported by: Trained Spotter

Hail in ULSTER, NEW YORK
From 15-MAY-18 13:26:00 to 15-MAY-18 13:26:00 (EST-5)
Location: CENTERVILLE
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in ULSTER, NEW YORK
From 15-MAY-18 14:36:00 to 15-MAY-18 14:36:00 (EST-5)
Location: WHITEPORT
Magnitude: 0.75 
Reported by: Trained Spotter

Thunderstorm Wind in ULSTER, NEW YORK
From 15-MAY-18 15:05:00 to 15-MAY-18 15:05:00 (EST-5)
Location: GALEVILLE
Magnitude: 60.00 EG
Reported by: Public

Two tall Norway pines were downed on Hoagerburgh Road, one onto a house. Two houses experienced minor roof and flashing damage. Powerlines were down in the area as well.

Thunderstorm Wind in ULSTER, NEW YORK
From 15-MAY-18 15:10:00 to 15-MAY-18 15:10:00 (EST-5)
Location: WALLKILL
Magnitude: 60.00 EG
Reported by: Public

Several large trees were downed, some onto cars. An antenna on a house roof was also toppled.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:21:00 to 15-MAY-18 15:21:00 (EST-5)
Location: WAPPINGERS FALLS
Magnitude: 60.00 EG
Reported by: Newspaper

Route 9D was closed for several hours in Wappingers Falls due to downed trees.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:21:00 to 15-MAY-18 15:21:00 (EST-5)
Location: ONIAD LAKE
Magnitude: 50.00 EG
Reported by: Newspaper

Trees were downed on Tuscany Drive near Wappingers Falls.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:28:00 to 15-MAY-18 15:28:00 (EST-5)
Location: SHENANDOAH
Magnitude: 60.00 EG
Reported by: Newspaper

Several large trees were downed on the Appalachian Trail north of the Taconic State Parkway.

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 14:19:00 to 15-MAY-18 14:19:00 (EST-5)
Location: ANCRAM
Magnitude: 1.50 
Reported by: Social Media

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 14:06:00 to 15-MAY-18 14:06:00 (EST-5)
Location: COPAKE FALLS
Magnitude: 0.88 
Reported by: Public

Hail in ULSTER, NEW YORK
From 15-MAY-18 14:30:00 to 15-MAY-18 14:30:00 (EST-5)
Location: BINNEWTER
Magnitude: 0.88 
Reported by: Public

Thunderstorm Wind in ULSTER, NEW YORK
From 15-MAY-18 14:31:00 to 15-MAY-18 14:31:00 (EST-5)
Location: STONE RIDGE
Magnitude: 50.00 EG
Reported by: Trained Spotter

Two trees were downed.

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 13:47:00 to 15-MAY-18 13:47:00 (EST-5)
Location: MANORTON
Magnitude: 1.75 
Reported by: Public

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 13:50:00 to 15-MAY-18 13:50:00 (EST-5)
Location: CHATHAM CENTER
Magnitude: 1.50 
Reported by: Social Media

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 13:49:00 to 15-MAY-18 13:49:00 (EST-5)
Location: LIVINGSTON
Magnitude: 2.00 
Reported by: Social Media

Hail in ULSTER, NEW YORK
From 15-MAY-18 14:39:00 to 15-MAY-18 14:39:00 (EST-5)
Location: BLOOMINGTON
Magnitude: 1.00 
Reported by: Social Media

Thunderstorm Wind in ULSTER, NEW YORK
From 15-MAY-18 15:00:00 to 15-MAY-18 15:00:00 (EST-5)
Location: DWAAR KILL
Magnitude: 50.00 EG
Reported by: Amateur Radio

Trees were reported down.

Hail in ULSTER, NEW YORK
From 15-MAY-18 13:39:00 to 15-MAY-18 13:39:00 (EST-5)
Location: MT PLEASANT
Magnitude: 1.75 
Reported by: Public

Hail in ULSTER, NEW YORK
From 15-MAY-18 13:37:00 to 15-MAY-18 13:37:00 (EST-5)
Location: SAUGERTIES
Magnitude: 1.50 
Reported by: Public

Hail in ULSTER, NEW YORK
From 15-MAY-18 14:05:00 to 15-MAY-18 14:05:00 (EST-5)
Location: LADLETON
Magnitude: 0.75 
Reported by: Trained Spotter

Hail in ULSTER, NEW YORK
From 15-MAY-18 14:23:00 to 15-MAY-18 14:23:00 (EST-5)
Location: OLIVEBRIDGE
Magnitude: 0.88 
Reported by: Social Media

Hail in ULSTER, NEW YORK
From 15-MAY-18 14:30:00 to 15-MAY-18 14:30:00 (EST-5)
Location: WHITEPORT
Magnitude: 0.88 
Reported by: Trained Spotter

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 13:51:00 to 15-MAY-18 13:51:00 (EST-5)
Location: SNYDERVILLE
Magnitude: 2.00 
Reported by: Emergency Manager

Hail shattered windows of two vehicles on the Taconic State Parkway near the Gallatin Overlook.

Hail in ULSTER, NEW YORK
From 15-MAY-18 13:57:00 to 15-MAY-18 13:57:00 (EST-5)
Location: MT MERION PARK
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:19:00 to 15-MAY-18 15:19:00 (EST-5)
Location: CHELSEA
Magnitude: 50.00 EG
Reported by: NWS Storm Survey

Trees were downed along Chelsea Road.

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 14:05:00 to 15-MAY-18 14:05:00 (EST-5)
Location: COPAKE
Magnitude: 1.00 
Reported by: Trained Spotter

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:34:00 to 15-MAY-18 15:34:00 (EST-5)
Location: HOLMES
Magnitude: 75.00 EG
Reported by: Public

Several large pine trees were snapped two feet above the ground.

Hail in COLUMBIA, NEW YORK
From 15-MAY-18 14:06:00 to 15-MAY-18 14:06:00 (EST-5)
Location: NEVIS
Magnitude: 2.00 
Reported by: Trained Spotter

Tornado in DUTCHESS, NEW YORK
From 15-MAY-18 13:34:00 to 15-MAY-18 13:35:00 (EST-5)
Location: VIEWMONTE
Tornado F-scale: EF0
Reported by: NWS Storm Survey

A tornado that touched down between Woodstock and Saugerties in Ulster County crossed the Hudson River into Dutchess County and ended in Tivoli, just south of the Clermont State Historic Site. The damage in Dutchess County was rated EF-0, with several trees damaged or downed.

Thunderstorm Wind in DUTCHESS, NEW YORK
From 15-MAY-18 15:18:00 to 15-MAY-18 15:26:00 (EST-5)
Location: CASTLE PT
Magnitude: 91.00 EG
Reported by: NWS Storm Survey

A National Weather Service team determined that a macroburst occurred along the I-84 corridor roughly between Beacon/Wappingers Falls and East Fishkill/Hopewell Junction. The macroburst toppled and uprooted hundreds of trees. Some trees fell on structures, and a tree was downed onto I-84 blocking a lane. There was limited direct damage from wind to structures. A fallen chimney was noted and some siding was ripped off a few homes. The damage swath was around seven miles long and three miles wide.

Tornado in ULSTER, NEW YORK
From 15-MAY-18 13:29:00 to 15-MAY-18 13:34:00 (EST-5)
Location: CENTERVILLE
Tornado F-scale: EF1
Reported by: NWS Storm Survey

The tornado path started along Route 212 between Woodstock and Saugerties and moved east through the western and southern part of Saugerties before crossing the Hudson River and ending in Tivoli, just south of the Clermont State Historic Site.
The majority of the tornado damage was rated EF-0, but isolated EF-1 damage was noted. Most of the damage was indirect, from trees falling on homes, other structures, and power lines. Downed trees blocked the southbound exit ramp from the New York State Thruway at the Saugerties exit.