A large, complex winter storm moved across the Great Lakes on December 29th and eventually stalled on December 30th and 31st. Meanwhile, secondary low pressure developed near Pennsylvania on December 30th and moved across southern New England on the 31st.
A wintry mix of freezing rain, sleet and some snow moved into New York by the evening of December 29th and continued steadily until midday on December 30th before tapering to showers of mixed precipitation and snow on the afternoon of the 30th.
Predominantly freezing rain and sleet fell across the southern Adirondacks and St. Lawrence valley. Ice accumulations ranged from 1/3 to 1 inch in the St. Lawrence valley, greater amounts in the north toward Massena (3/4-1 inch). In the southern Adirondacks of SE St. Lawrence, southern Franklin and western Essex, ice accumulations were 1/3 to 1/2 inch along with some sleet, snow and rain.
Main impacts were hazardous road conditions Sunday night (29th) and Monday morning (30th) along with thoiusands without power in St. Lawrence county.

Winter Storm in WESTERN ESSEX, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Several ground truth reports of around 1/2 inch of ice accretion on many objects as well as being mixed with sleet and snow at times. Hazardous travel and power outages were the main impacts.

Winter Weather in EASTERN ESSEX, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: COOP Observer

A wintry mix of snow, sleet and freezing rain fell across the area with generally less than 1/4 inch of ice and 2-4 inches of a combination of snow and sleet.

Winter Weather in WESTERN CLINTON, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: COOP Observer

A wintry mix of snow, sleet and freezing rain fell across the area with 1/4 to 1/3 ice accumulation and 2-4 inches of a combination of snow and sleet.

Winter Storm in NORTHERN FRANKLIN, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 50.00K
Crop damage: 0.00K
Reported by: ASOS

Massena ASOS reported 0.92 inches of freezing rain. In addition several ground truth reports of 1/3 to 3/4 inch of ice accretion on many objects.
Hazardous travel and power outages were the main impacts.

Winter Weather in EASTERN CLINTON, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: COOP Observer

A wintry mix of snow, sleet and freezing rain fell across the area with generally less than 1/4 inch of ice and 2-4 inches of a combination of snow and sleet.

Winter Weather in SOUTHEASTERN ST. LAWRENCE, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: COOP Observer

A wintry mix of snow, sleet and freezing rain fell across the area with generally less than 1/4 inch of ice and 1-3 inches of a combination of snow and sleet.

Winter Weather in SOUTHERN FRANKLIN, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: COOP Observer

A wintry mix of snow, sleet and freezing rain fell across the area with generally less than 1/4 inch of ice and 1-3 inches of a combination of snow and sleet.

Winter Storm in NORTHERN ST. LAWRENCE, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 50.00K
Crop damage: 0.00K
Reported by: ASOS

Massena ASOS reported 0.92 inches of freezing rain. In addition several ground truth reports of 1/2 to 3/4 inch of ice accretion on many objects. At times, precipitation mixed with sleet and brisk northeast winds of 20 to 30 mph accompanied the wintry mix.
Hazardous travel and power outages were the main impacts.

Winter Storm in SOUTHWESTERN ST. LAWRENCE, NEW YORK
From 29-DEC-19 18:00:00 to 30-DEC-19 15:00:00 (EST-5)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several ground truth reports around 1/2 inch of ice accretion on many objects. At times, precipitation mixed with sleet and brisk northeast winds of 15 to 25 mph accompanied the wintry mix.
Hazardous travel and scattered power outages were the main impacts.