On May 9th, a surface low and cold front moved from the Great Lakes across northern New York and Vermont, along a stationary boundary draped across the Adirondacks and central Vermont. This stationary boundary separated the cool, moist and stable air to the north, from the warm, moist and unstable air south. In addition a long-lived, strong mid-level shortwave and associated thunderstorm complex traveled across the Great Lakes and along this boundary across Vermont during the afternoon hours.
Severe thunderstorms and a developing squall line produced large hail up to an inch in diameter as well as damaging winds that knocked down trees and power lines to portions of central Vermont, especially the Middlebury vicinity. In addition, an EF1 tornado developed and briefly touched down in advance of the squall line in the town of Washington (Orange county). Some structural damage occurred to an apartment roof, school awning and destroyed a 60 foot hoop barn made of fabric and steel tubing.

Thunderstorm Wind in ORANGE, VERMONT
From 09-MAY-09 16:20:00 to 09-MAY-09 16:20:00 (EST-5)
Location: EAST RANDOLPH
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

State Police report trees downed by thunderstorm winds.

Hail in ADDISON, VERMONT
From 09-MAY-09 15:22:00 to 09-MAY-09 15:22:00 (EST-5)
Location: BRIDPORT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Nickel size hail reported.

Thunderstorm Wind in ADDISON, VERMONT
From 09-MAY-09 15:32:00 to 09-MAY-09 15:35:00 (EST-5)
Location: MIDDLEBURY
Magnitude: 52.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Numerous reports of trees and power lines down as well as closed roads due to thunderstorm winds across Middlebury as well as scattered reports in Whiting and Cornwall.

Hail in WASHINGTON, VERMONT
From 09-MAY-09 15:45:00 to 09-MAY-09 15:45:00 (EST-5)
Location: NORTHFIELD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

One inch diameter reported.

Hail in WINDSOR, VERMONT
From 09-MAY-09 16:20:00 to 09-MAY-09 16:20:00 (EST-5)
Location: EAST BARNARD
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Penny size hail reported.

Thunderstorm Wind in WINDSOR, VERMONT
From 09-MAY-09 16:10:00 to 09-MAY-09 16:10:00 (EST-5)
Location: BETHEL
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

State Police reported trees down by thunderstorm winds.

Tornado in ORANGE, VERMONT
From 09-MAY-09 16:04:00 to 09-MAY-09 16:05:00 (EST-5)
Location: WASHINGTON
Tornado F-scale: EF1
Property damage: 125.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A brief EF1 tornado touched down in the town of Washington that snapped and uprooted trees, partially ripped off roof from apartment building, damaged school awning and destroyed steel truss and fabric cow barn.

Thunderstorm Wind in ORANGE, VERMONT
From 09-MAY-09 16:15:00 to 09-MAY-09 16:15:00 (EST-5)
Location: SOUTH RANDOLPH
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees reported downed by thunderstorm winds.

Thunderstorm Wind in WINDSOR, VERMONT
From 09-MAY-09 16:20:00 to 09-MAY-09 16:20:00 (EST-5)
Location: EAST BARNARD
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A large maple tree, 15 inches in diameter, fell by thunderstorm winds.

Thunderstorm Wind in ORANGE, VERMONT
From 09-MAY-09 16:25:00 to 09-MAY-09 16:25:00 (EST-5)
Location: WAITS RIVER
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Employee

Several 8-10 inch diameter trees downed by thunderstorm winds along Route 25 between East Corinth and Waits River, reported by retired NWS employee.