The Tornadoes That Hit Massachusetts and Connecticut, Explained

At least two tornadoes raced across southwestern New England Sunday night.

One was reported across Litchfield County in Connecticut, two miles south/southwest of Falls Village. Multiple people called 911 to report the tornado at 6:09 p.m.

Another tornado was sighted in Berkshire County in Massachusetts at 6:59 p.m. Specifically, the tornado was sighted on South Main Street in Sandisfield, Massachusetts, with trees and wires down.

This storm originally formed between Poughkeepsie and Newburgh, New York, around 4:20 p.m. and started to strengthen and track northeast. The storm began to rotate seemingly once it came in contact with the Litchfield Hills in Connecticut, just before crossing the state line near Sharon, Connecticut. At 5:50, the storm had lots of cloud to ground lightning strikes -- a sign that it strengthened. On precipitation mode on radar, you could start to see a notch, indicating possible rotation.

At 6:09 p.m., the National Weather Service out of Albany issued the first tornado warning for Litchfield County in Connecticut, and Berkshire County in Massachusetts. In the warning, they listed these towns in the path: Canaan, Ashley Falls, Norfolk, Sandisfield and Otis.

That rotation became clear on velocity mode too. Rotation tracks showed up just after Sharon as the storm headed northeast.

Tornado Timeline: Tracking Sunday's Powerful Storm System

The storm was south of Canaan at 6:16 p.m. and continued to show rotation tracks on radar.

The storm crossed into Massachusetts at approximately 6:45 p.m., around the time the National Weather Service extended another tornado warning. This is where the storm set down another tornado around Sandisfield, Massachusetts. The rotation disappeared just before the storm reached the Massachusetts Turnpike in Berkshire County.

In a 20 year period from 1999 to 2010, each New England state averages one to three tornadoes per year. So these tornadoes are within the average range for a season. New England tornadoes are rare compared to the rest of the country, specifically tornado alley in the Great Plains, where some states there average 50 to 100 tornadoes per year.

The National Weather Service will be out surveying the damage from Sunday night. They will determine just how many tornadoes there were and how strong, using the E-F scale.

PHOTOS: Damage Reported in Mass., Conn. Communities After Tornadoes Touch Down