A low pressure system that just grazed extreme southeast New Jersey during the morning of the 21st brought a wintry mix of snow, sleet and freezing rain to the state. Snowfall averaged 1 to 3 inches in the southern half of the state and 3 to 6 inches in the northern half of the state. Ice accretions averaged around one tenth of an inch, mainly in the middle and southwestern part of the state. The overall number of accidents were less because this occurred on a Saturday. There were speed reductions on most of the major highways in New Jersey and also along the New Jersey Turnpike.
Snow overspread New Jersey between Midnight EST and 3 a.m. EST on the 21st from southwest to northeast. In southeastern New Jersey, the snow changed to sleet and freezing rain (inland) between 5 and 6 a.m. EST and then changed to plain rain between 6 a.m. EST and 8 a.m. EST.  Some spottier freezing rain persisted well inland. Precipitation ended during the middle of the afternoon on the 21st. In southwest New Jersey, the snow changed to sleet and freezing rain between 6 a.m. EST and 9 a.m. EST. Precipitation was spottier after 9 a.m. EST, but remained a wintry mix until it ended by the middle of the afternoon on the 21st. In northern New Jersey, some sleet mixed in before the snow ended during the early afternoon on the 21st.
Representative snowfall included 6.0 inches in Butler (Morris County), 5.5 inches in Marcella (Morris County) and Wantage (Sussex County), 4.7 inches in Hackettstown (Warren County), 4.5 inches in Lafayette (Sussex County), 4.0 inches in Flemington (Hunterdon County), 3.8 inches in Cheesquake (Middlesex County), 3.5 inches in Belle Mead (Somerset County), 3.0 inches in Swedesboro (Gloucester County), Mendham (Morris County), Phillipsburg (Warren County) and Monroe Township (Middlesex County), 2.9 inches in Freehold (Monmouth County), 2.7 inches in Ewing (Mercer County) and Pottersville (Somerset County), 2.5 inches in Hightstown (Mercer County), Bordentown and Moorestown (Burlington County), 2.3 inches in National Park (Gloucester County), 2.0 inches in Lambertville (Hunterdon County) and Pittsgrove (Salem County), 1.7 inches in Lakewood (Ocean County), 1.6 inches at the Atlantic City International Airport, 1.5 inches in Tabernacle (Burlington County) and Ocean Township (Monmouth County), 1.3 inches in Pennsauken (Camden County), 1.0 inch in Egg Harbor Township (Atlantic County) and Middle Township (Cape May County) and 0.5 inches in Bayville (Ocean County).

The low pressure system responsible for the wintry mix formed on a cold front over the Southern Plains on the 20th. At 7 p.m. EST on the 20th, it reached Arkansas. It moved northeast and reached Kentucky at 1 a.m. EST on the 21st, the lower Chesapeake Bay at 7 a.m. EST on the 21st, just east of Cape May, New Jersey at 10 a.m. EST on the 21st and about 100 miles east of the New Jersey coast at 1 p.m. EST on the 21st. The track of the low pressure system made it difficult for warm air to move in at the surface in most of the state (except southeast), even if it warmed enough aloft to change the snow to either sleet or freezing rain.

Winter Weather in SUSSEX, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WARREN, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MORRIS, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in HUNTERDON, NEW JERSEY
From 21-JAN-12 02:00:00 to 21-JAN-12 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in SOMERSET, NEW JERSEY
From 21-JAN-12 02:30:00 to 21-JAN-12 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MIDDLESEX, NEW JERSEY
From 21-JAN-12 02:30:00 to 21-JAN-12 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN MONMOUTH, NEW JERSEY
From 21-JAN-12 02:30:00 to 21-JAN-12 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN MONMOUTH, NEW JERSEY
From 21-JAN-12 02:30:00 to 21-JAN-12 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MERCER, NEW JERSEY
From 21-JAN-12 02:00:00 to 21-JAN-12 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in SOUTHEASTERN BURLINGTON, NEW JERSEY
From 21-JAN-12 02:00:00 to 21-JAN-12 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN OCEAN, NEW JERSEY
From 21-JAN-12 02:00:00 to 21-JAN-12 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN OCEAN, NEW JERSEY
From 21-JAN-12 02:00:00 to 21-JAN-12 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CAMDEN, NEW JERSEY
From 21-JAN-12 02:00:00 to 21-JAN-12 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in GLOUCESTER, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in SALEM, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CUMBERLAND, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN CAPE MAY, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN CAPE MAY, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN ATLANTIC, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN ATLANTIC, NEW JERSEY
From 21-JAN-12 01:00:00 to 21-JAN-12 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in NORTHWESTERN BURLINGTON, NEW JERSEY
From 21-JAN-12 02:00:00 to 21-JAN-12 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter