A complex area of low pressure over the middle Atlantic, which involved several individual centers, slowly consolidated off the Virginia Capes Tuesday morning, March 20th into Wednesday March 21st along a frontal boundary. This primary low, the fourth nor'easter of the month, gradually moved northeast Wednesday night to a position southeast of the 40 North/70 West ���Benchmark��� coordinates on Thursday morning.
Rain developed across southern and central Delaware on Tuesday morning, March 20th. As this precipitation moved northward into a colder air mass, snow and sleet developed across the remainder of northern Delaware during the Tuesday afternoon hours.
Northeast winds increased throughout Tuesday, and gusted 40 to 50 mph along the Atlantic and Delaware Bay Coasts from Tuesday afternoon into Wednesday morning.
Minor coastal flooding occurred along the Delaware oceanfront, as well as Delaware Bay, around the times of high tide Tuesday night, Wednesday morning, and again Wednesday night.
During Tuesday evening, a mixed bag of precipitation developed, with freezing rain, sleet, and snow, except rain closer to the coast.
Freezing rain lead to ice accretion up to 0.20��� across portions of northern Delaware, causing downed trees and limbs, which impacted power lines, and lead to power outages.
The change over to snow progressed southeast across Delaware by late morning on Wednesday, March 21st, with the exception of Sussex County Delaware, where it did not occur until the early to mid-afternoon.
Moderate to heavy snowfall developed, and gradually overspread Delaware from Wednesday morning into the evening. Snowfall rates, particularly outside of southern Delaware, were around one inch per hour at times. The snow gradually ended from west to east around midnight.
Snowfall amounts generally ranged 6 to 9 inches in New Castle County, 3 to 6 inches in Kent County, and 1 to 3 inches in Sussex County.
The weight of the heavy, wet snow brought down trees, limbs, and power lines across portions of Delaware, which lead to power outages.

Winter Weather in INLAND SUSSEX, DELAWARE
From 21-MAR-18 10:00:00 to 22-MAR-18 01:00:00 (EST-5)
Reported by: Mesonet

Precipitation began as rain during the morning hours of Tuesday, March 20th, then continued through the evening hours on March 20th. After a lull during the overnight hours, a drier snow began falling during the afternoon hours on the 21st following some early rain, then a wintry mix of snow, sleet, and freezing rain. Snow became heavy at times during the afternoon and evening hours away from the coast. Some reported snowfall amounts include: 4.0 inches in Dagsboro, 3.2 inches near Sycamore, 2.2 inches in Seaford, 2.1 inches in Ellendale, 2.0 inches in Stockley, 1.7 inches in Seaford and Bridgeville, 1.6 inches in Laurel, 1.5 inches in Milton, and 1.0 inches in Georgetown.
Northeast winds gusted up to 50 MPH at times Tuesday night. Minor coastal flooding was reported along the Delaware Bay shores around the times of high tide Tuesday night, Wednesday morning, and again Wednesday night.

Winter Weather in DELAWARE BEACHES, DELAWARE
From 21-MAR-18 10:00:00 to 22-MAR-18 01:00:00 (EST-5)
Reported by: Mesonet

Precipitation began as rain during the morning hours of Tuesday, March 20th, then continued through the evening hours on March 20th. After a lull during the overnight hours, rain began falling again during the afternoon hours on the 21st. This rain mixed with sleet and freezing rain during the late afternoon hours before changing over to all snow during the evening hours as colder air moved in from the north. Some reported snowfall amounts include: 0.7 inches in Lewes, and 0.6 inches in Bethany Beach.
Northeast winds gusted up to 50 MPH at times Tuesday night. Minor coastal flooding was reported around the times of high tide Tuesday night, Wednesday morning, and again Wednesday night.

Winter Storm in KENT, DELAWARE
From 21-MAR-18 09:00:00 to 22-MAR-18 00:00:00 (EST-5)
Reported by: Trained Spotter

Precipitation began as rain during the morning hours of Tuesday, March 20th, then gradually changed over to a snow-sleet-freezing rain mixture during the late afternoon hours on March 20th, adversely affecting the evening commute. After a lull during the overnight hours, a drier snow began falling by late morning on the 21st following some early sleet and freezing rain. Snow became heavy at times during the afternoon and evening hours in the northern half of the county.  Some reported snowfall amounts include: 7.5 inches in Woodside, 7.0 inchs in Milford, 7.0 inches in Hazlettville, 5.7 inches in Dover, 5.5 inches in Clayton, 5.3 inches in Harrington, 4.8 inches in Smyrna, and 4.0 inches in Frederica.

Winter Storm in NEW CASTLE, DELAWARE
From 21-MAR-18 07:00:00 to 21-MAR-18 23:00:00 (EST-5)
Reported by: Trained Spotter

Precipitation began as rain during the morning hours of Tuesday, March 20th, then gradually changed over to a snow-sleet-freezing rain mixture during the late afternoon hours on March 20th, adversely affecting the evening commute. After a lull during the overnight hours, a drier snow began falling by late morning on the 21st following some early sleet and freezing rain. Snow became heavy at times during the afternoon and evening hours.  Some reported snowfall amounts include: 9.5 inches in Middletown, 9.0 inches in Townsend, 8.1 inches at New Castle County Airport, 7.6 inches in Glasgow, 7.2 inches in Greenville, 7.0 inches at Talley Farms, 6.4 inches in New Castle, 6.2 inches in Prices Corner, 6.0 inches in Bear, 5.9 inches in Newark, 5.8 inches in Claymont, and 5.0 inches in Pike Creek.