A very warm and humid air mass was in place over western Massachusetts during the day on Sunday, May 29th. Although strong upper level ridging was initially in place over the area, an upper level trough started to approach from the west, with a surface cold front moving towards the area from Canada.
During the afternoon hours, bands of slow moving showers and thunderstorms broke out over the Berkshires and slowly moved northeast. Due to the slow movement of these thunderstorms, heavy rainfall repeatedly fell over the same area in the Lee and Stockbridge portions of Berkshire County.  This resulted in flash flooding occurring across the area, as some roads were temporarily closed due to being covered by water and debris.   The flooding was so significant in Stockbridge that town officials declared a state of emergency. Spotters measured up to five inches of rainfall falling in just a few hours.
In addition, the thunderstorms produced gusty winds.  This downed some trees and power lines across the area as well.
With the loss of daytime heating, showers and thunderstorms ended by the evening hours and the weather was quiet into the overnight hours. This allowed water to quickly recede across the region.

Flash Flood in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 14:05:00 to 29-MAY-16 16:45:00 (EST-5)
Location: LEE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy rainfall from slow moving thunderstorms resulted in flash flooding in Lee.  East Center Street was impassable due to high water.

Flash Flood in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 14:20:00 to 29-MAY-16 16:45:00 (EST-5)
Location: EAST LEE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy rainfall from slow moving thunderstorms resulted in flash flooding in Lee.  Forest  Street was impassable due to high water and debris.

Thunderstorm Wind in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 13:40:00 to 29-MAY-16 13:40:00 (EST-5)
Location: STOCKBRIDGE
Magnitude: 50.00 EG
Reported by: Amateur Radio

Trees were reported down at the Stockbridge Cemetary in Stockbridge due to thunderstorm high winds.

Thunderstorm Wind in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 13:35:00 to 29-MAY-16 13:35:00 (EST-5)
Location: GLENDALE
Magnitude: 50.00 EG
Reported by: Amateur Radio

Trees were reported down on wires in Glendale due to thunderstorm high winds.

Thunderstorm Wind in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 14:05:00 to 29-MAY-16 14:05:00 (EST-5)
Location: LENOX DALE
Magnitude: 50.00 EG
Reported by: Amateur Radio

A tree was down on wires in Lenoxdale due to thunderstorm high winds.

Thunderstorm Wind in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 14:00:00 to 29-MAY-16 14:00:00 (EST-5)
Location: LEE
Magnitude: 50.00 EG
Reported by: Newspaper

A tree was downed due to thunderstorm high winds in Lee.  The tree fell on a home resulting in minor damage.

Flash Flood in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 14:00:00 to 29-MAY-16 16:45:00 (EST-5)
Location: SOUTH LEE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy rainfall from slow moving thunderstorms resulted in flash flooding in Lee.  Fairview street was closed due to high water and a car was trapped within the flood waters on Fairview Street beneath the Massachusetts Turnpike overpass.

Flash Flood in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 13:45:00 to 29-MAY-16 16:45:00 (EST-5)
Location: STOCKBRIDGE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy rainfall from slow moving thunderstorms resulted in flash flooding in Stockbridge.  Main street was impassable due to high water.  The bottom floor of the town office building had standing water that was mopped up before it could do any damage to equipment in the offices.  Some nearby homes on Church Street had water in their basements as well.

Flash Flood in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 13:43:00 to 29-MAY-16 16:45:00 (EST-5)
Location: STOCKBRIDGE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Slow moving thunderstorms resulted in flash flooding in Stockbridge at the police station on West Stockbridge Road.  Also, a portion of Route 183 was closed due to flooding in the village of Interlaken, where flooding impacted an ongoing culvert project near the Massachusetts Turnpike overpass.  A portion of Glendale road was closed as well.

Thunderstorm Wind in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 14:00:00 to 29-MAY-16 14:00:00 (EST-5)
Location: LEE
Magnitude: 50.00 EG
Reported by: Amateur Radio

Wires were reported down on Greylock Street in Lee due to thunderstorm high winds.

Flash Flood in BERKSHIRE, MASSACHUSETTS
From 29-MAY-16 14:00:00 to 29-MAY-16 16:45:00 (EST-5)
Location: LEE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy rainfall from slow moving thunderstorms resulted in flash flooding in Lee.  Greylock Street was closed due to high water.