A strong low pressure system over the Great Lakes drew in moisture across southern New England, where cold air remained in place at the higher elevations.  This led to ice storm conditions on the 30th in a narrow region along the immediate east slopes of the Berkshires, where 0.5 to 0.75 inches of ice was observed.  Lesser amounts occurred in northern Worcester County. There was also some light snow and sleet, mainly north of the Mass Pike.  Weaker low pressure developed south of Long Island on the 31st, which prolonged light precipitation.
Elevated instability during the afternoon of the 30th led to thunderstorms tracking across the Poconos, eastern NY, and into northern CT and western and central MA. One of these storms became severe, producing quarter-size hail in Southwick and Westfield, MA (Hampden County) - very unusual for the end of December.

Hail in HAMPDEN, MASSACHUSETTS
From 30-DEC-19 15:34:00 to 30-DEC-19 15:34:00 (EST-5)
Location: SOUTHWICK
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Quarter size hail fell in Southwick, MA at 334 PM EST from an isolated severe thunderstorm.  This was a very unusual event for late December.  It was definitely bona fide hail, not related to the ongoing sleet/freezing rain event.

Hail in HAMPDEN, MASSACHUSETTS
From 30-DEC-19 15:40:00 to 30-DEC-19 15:44:00 (EST-5)
Location: WESTFIELD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Quarter size hail fell in Westfield, MA at from 340 through 344 PM EST from an isolated severe thunderstorm.  This was a very unusual event for late December.  It was definitely bona fide hail, not related to the ongoing sleet/freezing rain event.  Prior to the quarter size hail, dime size hail fell at this location starting at 338 PM EST.

Hail in HAMPDEN, MASSACHUSETTS
From 30-DEC-19 16:55:00 to 30-DEC-19 16:55:00 (EST-5)
Location: HIGHLANDS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Dime size hail from a thunderstorm was reported in Holyoke.

Hail in HAMPDEN, MASSACHUSETTS
From 30-DEC-19 17:16:00 to 30-DEC-19 17:16:00 (EST-5)
Location: NORTH WILBRAHAM
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Dime size hail from a thunderstorm was reported in Wilbraham.

Ice Storm in WESTERN FRANKLIN, MASSACHUSETTS
From 30-DEC-19 06:00:00 to 31-DEC-19 01:00:00 (EST-5)
Property damage: 0.30K
Crop damage: 0.00K
Reported by: Amateur Radio

One-half inch of ice accretion was reported in Rowe.  At 1044 AM in Ashfield, amateur radio operators reported wires downed and sparking on Hawley Road across from the Water Department shed.

Ice Storm in WESTERN HAMPSHIRE, MASSACHUSETTS
From 30-DEC-19 06:00:00 to 31-DEC-19 01:00:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Amateur Radio

One-half to three-quarters of an inch of ice accretion was reported throughout western Hampshire County.  In Goshen, 0.75 of ice was reported via amateur radio.  In Worthington, 0.50 of ice was reported by a utility company.  In Chesterfield, 0.50 of ice was reported via amateur radio.  An observer in Plainfield reported 0.40 of ice accretion.  In Goshen, at 754 AM a tree was reported down on wires on Ball Road and at 844 AM a tree was down on wires on Chesterfield Road and Spruce Corner Road.  In Huntington, at 754 AM a tree was down on wires on Searle Road and at 755 AM a tree was down on wires on County Road.  In Worthington, at 928 AM wires were down on Lindsey Hill Road and at 956 AM a tree was down on wires on Kinnebrook Road. At 948 AM in Plainfield, a large tree limb was down on wires...and burning on Gloyd Street at South Street.  In Chesterfield, at 1000 AM trees were down on Willcutt Road and Damon Pond Road and at 1038 AM wires were down on Don Emerson Road.  At 1152 AM in Cummington, tree limbs and wires were down on West Cummington Road by Luther Shaw Road. At 1252 PM in Worthington, a tree and wires were down on Old Post Road.

Ice Storm in WESTERN HAMPDEN, MASSACHUSETTS
From 30-DEC-19 06:00:00 to 31-DEC-19 01:00:00 (EST-5)
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Utility Company

In Blandford, a utility company reported 0.50 of ice accretion.  In Montgomery, at 754 AM amateur radio operators reported a tree down on wires on North Road and at 759 AM a tree was reported down on wires on Reservoir Road.  At 951 AM in Blandford, amateur radio operators reported multiple trees down on North Street.  At 1223 PM in Granville, a tree was down on wires on North Lane.  At 424 PM in Blandford, a report was received of a wire down.

Winter Weather in NORTHERN WORCESTER, MASSACHUSETTS
From 30-DEC-19 07:44:00 to 30-DEC-19 18:00:00 (EST-5)
Property damage: 7.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Approximately 0.10 to 0.25 of ice accretion occurred in northern Worcester County.
At 744 AM in Barre, a pine tree fell onto wires on Pleasant Street.  At 750 AM in Princeton, a tree was down on wires on Bigelow Road.  At 756 AM in Petersham, wires were down on Nichewaug Road at Gay Drive. At 800 AM in Westminster, power lines and cable wires were down on Partridge Hill Road. At 820 AM in Gardner, wires were down on Chatham Street and at 832 AM, part of a tree fell on a house and blocked part of the doorway on Champagne Road.  In Petersham again at 838 AM, wires were reported down on Choate Drive. At 1128 AM in Phillipston, a tree was reported down.  At 1152 AM in Warren, a tree was down on Coy Road.  At 122 PM in Rutland, a wire was down on a driveway on Sawyer Street.  At 122 PM in Holden, a tree was down at Manning Street and General Hobbs Road. At 149 PM in Westminster, a tree was down on wires.  At 452 PM in Gardner, a tree was reported down on wires. At 600 PM in Fitchburg, wires were reported down.

Winter Weather in EASTERN FRANKLIN, MASSACHUSETTS
From 30-DEC-19 06:00:00 to 30-DEC-19 23:00:00 (EST-5)
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Amateur Radio

Approximately 0.25 of ice accretion occurred in eastern Franklin County.  A trained spotter reported 0.50 of ice in New Salem, but that was considerably higher than immediate surrounding areas, such as Leyden, which reported only 0.12 of ice.  At 1001 AM in New Salem, amateur radio reported a tree down on wires on Wendell Road.

Winter Weather in NORTHWEST MIDDLESEX COUNTY, MASSACHUSETTS
From 30-DEC-19 06:00:00 to 31-DEC-19 01:00:00 (EST-5)
Property damage: 0.30K
Crop damage: 0.00K
Reported by: Amateur Radio

Approximately 0.10 to 0.25 of ice accretion occurred in northwesternmost Middlesex County.  At 855 AM in Ashby, a portion of a tree was reported down between Piper and Mayo Roads.

Winter Weather in SOUTHERN WORCESTER, MASSACHUSETTS
From 30-DEC-19 08:00:00 to 30-DEC-19 18:00:00 (EST-5)
Property damage: 0.70K
Crop damage: 0.00K
Reported by: Amateur Radio

Approximately 0.10 to 0.20 inches of ice accretion was reported in southern Worcester County.  At 308 PM in Charlton, wires were reported down.  At 458 PM in Westborough, an amateur radio operator reported a tree down.