Winter Weather — New Castle, Delaware

2007-01-21 to 2007-01-22 · New Castle, Delaware

Wider weather episode

A low pressure system that passed to the south of Delaware helped produce a wintry mix of precipitation from the late afternoon of the 21st into the early morning of the 22nd. Snowfall accumulations were generally around an inch or less and ice accretions were one-tenth of an inch or less. Untreated roads were very hazardous as air temperatures were below freezing throughout the event except for the immediate coast. Over 100 accidents were reported throughout the state.

Snow began falling during the late afternoon of the 21st. As warmer air moved in aloft, the snow changed to freezing rain and sleet during the middle of the evening on the 21st in Sussex County. Precipitation changed to plain rain along the immediate coast around 1 a.m. EST on the 22nd. The change to sleet and freezing rain occurred around Midnight EST in Kent County, but took until near the end of the precipitation event for the change to occur in northern New Castle County.

In New Castle County, more than 60 accidents occurred between 4 p.m. EST and 930 p.m. EST. The Summit Bridge and a southbound bridge on Delaware State Route 1 were closed because of icy conditions. Many accidents occurred on Delaware State Route 1 between Middletown and Delaware State Route 273. Vehicles were sliding off roadways and into other vehicles. In Kent County, about 20 accidents were reported during the event. There were many reports of black ice forming on untreated roadways overnight. Some schools had delayed openings on the 22nd. The Providence Creek Academy in Clayton was closed. In Sussex County, about 50 accidents were reported. The worst reported accident shut down Delaware State Route 404 near the Maryland border. Some schools had delayed openings on the morning of the 22nd.

Actual snow accumulations included 1.0 inch in Greenwood and Lewes (Sussex County) and 0.4 inches at the New Castle County Airport. The precipitation was caused by a low pressure system that developed along the western Gulf Coast on the 20th. The low pressure system moved northeast (around Noon EST on the 21st, it was located along the Alabama and Mississippi border) and a secondary low pressure system formed on its warm front over eastern North Carolina overnight on the 21st. The secondary low pressure system became the primary low and moved quickly eastnortheast off of the North Carolina coast during the morning of the 22nd. Another low pressure system moved through the Ohio Valley on the 21st before it weakened and dissipated that night. This low though was able to pump in warmer air aloft and help change the precipitation over to sleet and freezing rain.

Source: NOAA Storm Events Database, event_id 12303. Narrative written by the NWS forecast office that issued the report.