The Winter Storm is underway. Snow is falling in the northern half of KELOLAND, and along and south of I-90 there are some rain showers. That trend will continue into overnight. A band of snowfall packing snowfall rates to around an inch per hour is expected to set up from western to central to NE South Dakota toward the midnight hour (yellow circled area on this radar capture). SE South Dakota and NW Iowa could get some rain or freezing rain overnight.
Northerly winds will also pick up steam overnight. Sioux Falls and SE South Dakota were added to the Blizzard Warning. Not because they will get heavy snowfall – we probably won’t – but because any snow that falls will be driven by 50 mph winds,, with whiteout conditions in open areas. We also updated snowfall projections to reflect snow that came down last night and this morning. While snowfall should end Sunday night, blowing snow conditions will continue into early Monday morning because of the lingering strong winds.
A High Wind Warning has also been issued for Sunday for SE KELOLAND.
Overnight the heavier precipitation and strong winds start to kick in. The wild card is that areas along and south of I-90 will get rainfall. As the rain mixes with and changes to snow toward morning, it will be a wet, sloppy mess. Winds will start from the northeast and change to the north, around 40 mph – and gusts to 50 mph or a little more. Any snowfall that occurs will be blown by the wind, creating blizzard conditions.
Tomorrow we’ll be in full winter storm mode. Northerly gusts of 50 mph – and perhaps a little more – will continue to give us blizzard conditions thanks to occasionally heavy snowfall. Temperatures will be significantly colder than we’ve seen lately, with highs only in the 20s to around 30 degrees.
Snowfall totals by Sunday night will be significantly higher north of I-90, and there may be drifting due to the strong winds – and visibility problems in open areas.
As the system passes on Monday, it will leave behind a pool of cold air. Monday morning will start a few degrees either side of zero. Despite sunny skies, it won’t warm up very much. Monday afternoon highs will only be in the teens East River, while Rapid City rebounds to the low 30s.
There could be a few flurries on Tuesday for the real St. Patrick’s Day. Morning lows will again be near zero. With abundant clouds, afternoon highs will again be colder than normal, in the low 30s East River. Rapid City will be breezy, with a high in the 60s.
The rest of the week will be marked by a temperature surge from a massive pool of hot air coming out of the southwestern United States. Temperatures will be much above-normal for the second half of the week. Friday is the first day of Spring, so the warm air will be arriving right on time…