A wintry mix of precipitation affected northwest New Jersey as well as the Raritan Basin in central New Jersey from the afternoon and early evening of the 16th into the morning of the 17th. In spite of nearly twenty-four hours of precipitation, the intensity was mainly light. About 1 to 3 inches of snow accumulated before precipitation changed to freezing rain with ice accretions that averaged around two-tenths of an inch.
Precipitation started as snow during the late afternoon of the 16th in the Raritan Basin and spread north into Sussex County by early evening. As warmer air moved in aloft, the snow changed over to freezing rain during the late evening of the 16th and continued overnight. Precipitation changed over to plain rain just as it was ending in the Raritan Basin, but ended as freezing rain in places farther to the north around sunrise on the 17th.
The wintry mix caused numerous accidents and made traveling home difficult during the evening commute. Vehicles slid off roads, into each other and into ditches. About 15 accidents alone were reported in and around Sayreville (Middlesex County) on the Garden State Parkway. After school classes, sports activities and concerts were cancelled in Hunterdon, Somerset and Middlesex Counties.
Actual snow accumulations included 4.2 inches on Hell Mountain in Hunterdon County, 3.0 inches in Whitehouse (Hunterdon County), 2.8 inches in Morris Township and Roxbury Township (Morris County), 2.5 inches in Independence Township (Warren County), 2.4 inches in North Brunswick (Middlesex County), 2.2 inches in Franklin Township (Somerset County), 2.0 inches in Hopewell (Mercer County), Stewartsville (Warren County), Marcella (Morris County) and Bridgewater Township (Somerset County) and 1.0 inch in Holmdel (Monmouth County) and Sparta Township (Sussex County)
The wintry mix of precipitation was caused by a low pressure system that developed on a cold front in the Gulf Coast States on the morning of the 16th. It moved northnortheast and reached the Tennessee Valley early in the evening on the 16th and northeast Ohio at 1 a.m. EST on the 17th. The low pressure system then moved into the Great Lakes around sunrise on the 17th as a secondary low pressure system was forming off the New Jersey coast. The secondary low slowly intensified as it moved toward Cape Cod on the 17th as the primary low weakened over the Great Lakes. An arctic high pressure system moved across New York and New England on the 16th and provided a fresh supply of cold air near the surface that prevented temperatures from rising above freezing during this event across much of central and northwest New Jersey.

Winter Weather in MERCER, NEW JERSEY
From 16-DEC-08 15:00:00 to 17-DEC-08 05:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MIDDLESEX, NEW JERSEY
From 16-DEC-08 16:00:00 to 17-DEC-08 05:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in SOMERSET, NEW JERSEY
From 16-DEC-08 16:00:00 to 17-DEC-08 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in HUNTERDON, NEW JERSEY
From 16-DEC-08 16:00:00 to 17-DEC-08 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MORRIS, NEW JERSEY
From 16-DEC-08 16:00:00 to 17-DEC-08 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WARREN, NEW JERSEY
From 16-DEC-08 17:00:00 to 17-DEC-08 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in SUSSEX, NEW JERSEY
From 16-DEC-08 19:00:00 to 17-DEC-08 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter