A winter storm dropped heavy snow across New Castle County and a sleet and snow mixture in the rest of Delaware from the evening of the 21st until around sunrise on the 22nd. Accumulations averaged 4 to 6 inches in New Castle County, 2 to 4 inches in Kent County and around 1 inch in Sussex County. Precipitation started as snow in New Castle County, snow and sleet in Kent County and sleet in Sussex County during the evening of the 21st. Precipitation changed to all snow late in the evening of the 21st in Kent County and just after midnight EST on the 22nd in Sussex County. The snow fell heavy at times around Midnight EST in New Castle County. The snow ended across the state from northwest to southeast between 4 a.m. EST and 7 a.m EST on the 22nd.
Delaware State Police responded to about sixty accidents, ten with injuries. There were also about two dozen disabled vehicles and two abandoned vehicles. The most reported accidents occurred in New Castle County. The most serious reported accident occurred in New Castle County in which a vehicle drove into a pole on the northbound ramp to Delaware State Route 141 from Interstate 95 near the New Castle County Airport. Both women in the vehicle were hospitalized.  In Kent County, the State Department of Education's Collette Education Center in Dover was evacuated for the 22nd after the heavy wet snow started to flex and deflect the center's roof.
Representative snowfall included 5.6 inches in Newark (New Castle County), 4.7 inches at the New Castle County Airport, 4.4 inches in Blackbird (New Castle County), 4.3 inches in Dover (Kent County), 4.0 inches in Claymont (New Castle County), 3.1 inches in Viola (Kent County), 2.0 inches in Harrington (Kent County). 1.6 inches in Ellendale (Sussex County), 1.5 inches in Lewes (Sussex County) and 0.7 inches from Bridgeville (Sussex County). The onshore flow coupled with the higher astronomical tides associated with the recent full moon caused minor tidal flooding in Sussex County with the late evening high tide on the 21st. The high tide reached 6.57 feet above mean lower low water at Breakwater Harbor. Minor tidal flooding starts at 6.0 feet above mean lower low water.
The winter storm was caused by a second in a series of low pressure systems that moved quickly west to east across the United States. This low pressure system moved eastsoutheast from Illinois on the morning of the 21st to near Cincinnati, Ohio at 7 p.m. EST on the 21st, near Raleigh, North Carolina at 1 a.m. EST on the 22nd and then sank south into South Carolina later that morning,  The general fast motion and direction of movement kept snowfall totals in the single numbers.

Winter Weather in KENT, DELAWARE
From 21-FEB-11 20:00:00 to 22-FEB-11 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in INLAND SUSSEX, DELAWARE
From 21-FEB-11 21:00:00 to 22-FEB-11 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in DELAWARE BEACHES, DELAWARE
From 21-FEB-11 22:00:00 to 22-FEB-11 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in NEW CASTLE, DELAWARE
From 21-FEB-11 20:00:00 to 22-FEB-11 05:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter