A major winter storm continues to develop this morning and will impact much of our region throughout the weekend. A Winter Storm Warning has been issued for much of South Dakota and parts of Minnesota and Iowa along and south of I-90.
We are starting today with areas of dense fog. Visibility has dropped to less than one-quarter mile in many places and a dense fog advisory is in effect through mid to late morning. With temperature is hanging around the freezing mark this morning, the fog will frost the roads making them slippery at times. Don’t get caught off guard. This afternoon will be cloudy with lingering fog and high temps in the mid to upper 30s.
Areas of light rain will develop this evening and change to freezing rain and sleet as temperatures fall during the night. Roads and sidewalks will become very slippery. Generally, ice accumulation will be around 0.10″ but there could will a few places – Northwestern Iowa, especially – that get between 0.10″ and 0.25″ of ice. By tomorrow morning precipitation will change to snow with snow continuing through tomorrow, tomorrow night and into Sunday. In addition to the snow, strong northeasterly wind gusts from 30 to 40 mph will create blowing snow from late tomorrow afternoon through tomorrow night and well into Sunday.
The heaviest snow will fall along and south of I-90. Accumulation amounts will range from about 3 to 6 inches in Sioux Falls, 6 to 12 inches further south along the Nebraska state line. As of right now, I think the heaviest amounts will be across South Central South Dakota and North Central Nebraska from Gregory to Winner to Valentine. Up to a foot or more of snow is possible there. Amounts will be lighter further north with 2 to 4 inches possible along US Highway 14 with an inch or less likely along and north of US Highway 212.