Winter Storm and Heavy Rain in Delaware, January 13 to 15, 1999

A very protracted precipitation event affected the Delmarva Peninsula on the 14th and 15th. The region escaped the worst conditions as enough warm air came in before the heavy rain arrived. Nevertheless about a quarter inch of ice accrued on power lines and limbs in extreme northern New Castle County. About 1,400 homes lost power. Less ice fell farther south. Little if any frozen precipitation fell in Sussex County.A cold front moved through the peninsula the evening of the 13th. Extremely cold air moved south behind it. Unlike the usual pattern with cold frontal passages, precipitation fell behind the front and slowly worked its way south during the early morning hours of the 14th. A weak low pressure system developed on the cold front in the Tennessee Valley on the 14th, but weakened as it moved east off the Delmarva Peninsula during the evening of the 14th. A very strong high pressure system built into northern New England on the 14th. The high moved offshore the evening of the 14th and the flow across the Middle Atlantic States became more easterly. This permitted warmer air to start moving back quicker into the region during the late afternoon and evening of the 14th just as a second and stronger low pressure system was getting organized over the Tennessee Valley. A secondary low formed near Norfolk during the early morning of the 15th and this not only accelerated the increase of warmer air, but also produced some heavy rain across the peninsula.A mixture of sleet, snow and freezing rain fell across New Castle County from around midnight on the 14th through the evening of the 14th. Freezing rain prevailed the rest of that night until air temperatures climbed above freezing during the early morning of the 15th. Ice accretions were nearly two tenths of an inch in Wilmington. A shorter version of this occurred in Kent County where only some light freezing rain and sleet fell into the afternoon of the 14th. Heavy rain moved across the region during the morning of the 15th just as all temperatures rose above the freezing mark. Storm total amounts averaged between 1.5 inches for the event, most of which fell during the morning of the 15th. There was some poor drainage flooding, but no serious problems were reported. The worst affects of this storm were felt in New Castle County. Schools were closed for two days (the 14th and 15th) above the Chesapeake and Delaware Canal. The triple AAA responded to over 150 calls for assistance. About 1,400 homes lost power in the county. Even after temperatures rose above freezing, the problems did not stop. Falling ice shattered four cars' windshields on the Delaware Memorial and Delaware State Route 1 Bridges. Lanes were closed on the bridges until all the ice either melted or fell.Storm precipitation totals (most of which fell the morning of the 15th) included 1.93 inches in Georgetown, 1.80 inches in Milford, 1.63 inches in Greenwood, 1.42 inches in Wilmington and 1.15 inches at the New Castle County Airport. Snow and sleet accumulations were mostly under half an inch.