A complex storm system will give us plenty of forecasting challenges the next 24 to 48 hours. First, snow has accumulated in much of western SD with over 6” around Rapid City and points south and west. The first wave of snow extended overnight north to Aberdeen where an inch or two has been reported as of 7am.
The main challenges today will be watching a band of t-storms with rain and sleet in eastern Nebraska and western Iowa. Rain mixed with sleet will be possible in Sioux Falls today. Heavy rain is possible in northwest Iowa (over .50”). The snow and precipitation will expand to the west and north of Sioux Falls through the afternoon.
There may be a lull in the activity late this evening before another round of snow develops tonight and tomorrow across eastern KELOLAND. Sioux Falls and much of the southeast will be under a winter weather advisory and could get more than 6” of sloppy wet snow with this storm. Even northeast KELOLAND will have a chance of 6” of snow tonight, and that’s why a winter storm watch is in effect.
Part of the problem with snow forecasting with this storm will be the t-storm activity in the warm sector of the storm across Iowa, Missouri, Kansas, and Oklahoma. Since the nature of those storms will be volatile, so will the moisture return to KELOLAND. Also, the snow that falls will be very heavy and wet, difficult to measure, and compacting during the day. The other issue is the strong wind. Northwest winds will gust over 40mph tomorrow in much of eastern and southeastern SD, NW IA, and SW MN.
Stay tuned to the latest forecasts through the day. No signs of sustained warmth yet in the 7 day forecast.