Dense Fog in Delaware, November 23 to 24, 1999

A nearly stationary high pressure system anchored over the nearby Atlantic brought Delaware dense fog for four days from the 21st through the 24th of November. Widespread visibilities of a quarter of a mile or less occurred. Dense fog first formed around daybreak on the 21st. As the high pressure system settled into the region and the light onshore flow became established, the fog began forming earlier and burning off later on successive days. Dense fog formed the evening of the 21st just before midnight and did not burn off until around noon on the 22nd. The next two evenings (the 22nd and 23rd), the dense fog formed around sunset and did not burn off as late as 11 a.m. EST the ensuing days. On the 24th, the winds shifted from the east to the southwest and this prevented widespread dense fog from forming again.The dense fog contributed to accidents across the area. Twelve fog related accidents occurred within one twenty-four hour period in northern Sussex County. One of the worst accidents was a six car crash on northbound Delaware State Route 896 the morning of the 22nd that sent three people to the hospital. A pick-up truck crashed into the back of a minivan while trying to stop at a red light and started a chain reaction crash that involved six vehicles. There were school delay openings on the 22nd throughout Kent and Sussex Counties.