The combination of a low pressure system that moved off the Eastern Seaboard and an upper air disturbance that moved across from the Great Lakes, produced snow across New Jersey from the night of the 2nd into the night of the 3rd. Snowfall averaged three to six inches across much of the area, with higher amounts as much as ten inches in Gloucester County.
Precipitation started as light rain and light snow across the region around Midnight EST on the 3rd.  Precipitation changed to snow by dawn on the 3rd. The snow increased in intensity during the afternoon of the 3rd, but air temperatures around freezing kept much snow from accumulating on roadways. This changed as the sun was setting during the evening rush. Across the immediate Philadelphia suburbs, the snow was enhanced by an upper air disturbance that made the air mass more unstable and capable of producing snow at greater rates. The snow was falling at the rate of an inch or two per hour during the late evening. The snow ended from north to south. It ended during the evening of the 3rd in the northern half of New Jersey and by 3 a.m. EST on the 4th across the southern half of the state. It was described as a stealth snowstorm as most of the heaviest snow occurred when it had the relatively least impact on the area.
Snow started to accumulate on untreated roadways during the evening rush and on all roadways as intensity increased later that evening. The accumulating roadway snow led to a slippery and slushy evening commute and when most of the reported accidents occurred. The snow was cited as the reason for canceling many township meetings on the evening of the 3rd. The bands of heavier accumulating snow also caused many schools to have delayed openings on the 4th.
Specific snowfalls included 10.0 inches in Glassboro (Gloucester County), 8.0 inches in West Deptford (Gloucester County), 7.6 inches in Pittsgrove (Salem County), 6.4 inches in Red Bank (Monmouth County), 6.1 inches in Washington Township (Gloucester County), 5.9 inches in Howell (Monmouth County), 5.6 inches in Hillsborough (Somerset County), 5.5 inches in Sicklerville (Camden County) and New Brunswick (Middlesex County), 5.5 inches in Brick (Ocean County), 5.4 inches in Somderdale (Camden County), 5.2 inches in Stockton (Hunterdon County) and Edison (Middlesex County), 5.0 inches in Southampton (Burlington County), Neshanic (Somerset County), Freehold (Monmouth County) and Princeton (Mercer County), 4.8 inches in Denville (Morris County), 4.7 inches in Hammonton (Atlantic County), 4.5 inches in Metuchen (Middlesex County) and Vernon (Sussex County), 4.4 inches in Moorestown (Burlington County), 4.3 inches in Hamilton Township (Atlantic County), 4.0 inches in Vineland (Cumberland County) and Ewing (Mercer County), 3.8 inches in Flemington (Hunterdon County), 3.7 inches in Burlington (Burlington County), Allamuchy (Warren County) and Woodbine (Cape May County), 3.5 inches in Marcella (Morris County), Newton (Sussex County), Bridgewater (Somerset County), Stewartsville (Warren County) and Tuckerton (Ocean County), 3.1 inches in Winslow (Camden County), 2.6 inches in Forked River (Ocean County), 2.3 inches in Boonton (Morris County) and 1.3 inches in Cape May Harbor (Cape May County).

The low pressure system that contributed to the snow formed on a stalled cold front over the southeastern United States on the 2nd. By 7 a.m. EST on the 3rd, it was located about 200 miles east of the Delmarva Peninsula and at 7 p.m. EST that evening it was approaching Nova Scotia. An inverted trough associated with that low pressure system combined with an upper air disturbance to cause enhanced snow across the region, especially the local Philadelphia suburbs during the late evening of the 3rd.

Winter Weather in SUSSEX, NEW JERSEY
From 03-FEB-09 04:00:00 to 03-FEB-09 18:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WARREN, NEW JERSEY
From 03-FEB-09 04:00:00 to 03-FEB-09 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in GLOUCESTER, NEW JERSEY
From 03-FEB-09 01:00:00 to 04-FEB-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in SALEM, NEW JERSEY
From 03-FEB-09 01:00:00 to 04-FEB-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in CUMBERLAND, NEW JERSEY
From 03-FEB-09 01:00:00 to 04-FEB-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MORRIS, NEW JERSEY
From 03-FEB-09 02:00:00 to 03-FEB-09 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in HUNTERDON, NEW JERSEY
From 03-FEB-09 01:00:00 to 03-FEB-09 22:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in SOMERSET, NEW JERSEY
From 03-FEB-09 01:00:00 to 03-FEB-09 22:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MIDDLESEX, NEW JERSEY
From 03-FEB-09 01:00:00 to 03-FEB-09 22:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN MONMOUTH, NEW JERSEY
From 03-FEB-09 01:00:00 to 03-FEB-09 22:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN MONMOUTH, NEW JERSEY
From 03-FEB-09 01:00:00 to 03-FEB-09 22:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN OCEAN, NEW JERSEY
From 03-FEB-09 01:00:00 to 04-FEB-09 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN OCEAN, NEW JERSEY
From 03-FEB-09 01:00:00 to 04-FEB-09 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MERCER, NEW JERSEY
From 03-FEB-09 00:00:00 to 04-FEB-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in SOUTHEASTERN BURLINGTON, NEW JERSEY
From 03-FEB-09 01:00:00 to 04-FEB-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN ATLANTIC, NEW JERSEY
From 03-FEB-09 04:00:00 to 04-FEB-09 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN ATLANTIC, NEW JERSEY
From 03-FEB-09 04:00:00 to 04-FEB-09 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN CAPE MAY, NEW JERSEY
From 03-FEB-09 05:00:00 to 04-FEB-09 01:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN CAPE MAY, NEW JERSEY
From 03-FEB-09 05:00:00 to 04-FEB-09 01:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in NORTHWESTERN BURLINGTON, NEW JERSEY
From 03-FEB-09 01:00:00 to 04-FEB-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in CAMDEN, NEW JERSEY
From 03-FEB-09 01:00:00 to 04-FEB-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter