SIOUX CITY -- It appears snow may be in store for Northwest Iowa, and conditions could be much worse in South Dakota, where a blizzard warning has been issued for areas just outside of Siouxland.
The National Weather Service in Sioux Falls is tracking a major storm that appears bound for the area Thursday and Friday. The blizzard area runs just north of Yankton, South Dakota, with a chance of 18 inches of snow in South Dakota and Minnesota, with 55 mph winds to follow.
With the precipitation that is coming, additional flooding could plague the area, to follow the flooding that started March 14 and lasted several days in Siouxland, NWS Meteorologist Brad Temeyer said Tuesday.
"We are expecting additional rises on area streams, creeks and rivers," Temeyer said.
He said it is too early to pinpoint the range of flooding ahead, since one factor is how much precipitation comes in snow or rain. Additionally, Temeyer said the April flooding will be less than the events in March, since the ground is no longer frozen and can more readily absorb water.
Snow is expected to start the latter half of Wednesday in western South Dakota, then move east. Vermillion, South Dakota, 30 miles northwest of Sioux City, isn't in the blizzard warning area, but is in a winter storm watch region.
For Sioux City, the weather service forecasts that initial rain will turn into snow late Thursday, then continue into early Friday, for up to 1 inch of accumulation.
Friday has projected high of 37 degrees in Sioux City, with patchy blowing snow, due to the heavy winds. The system should move on by later in the day, and the Saturday city forecast is for sunny skies, with a high of 47.
That's a big change from the last five days, which had daily temperatures high above 60 degrees in Sioux City, including 76 on Monday.
More northerly in Northwest Iowa, the forecast for Spencer shows the potential for 2 inches of snow in the event into Friday morning. The potential area for 2 inches of snow locally runs in a diagonal from Vermillion to Le Mars, Sheldon, Spencer and the Minnesota border.
"Even April can be snowy," National Weather Service Observing Program Leader Brad Adams said, citing a 2.5-inch snow on April 18, 2018, in Sioux City.
There was snow in Sioux City already once this month, on April 1. April 6 has been historically shown as the average last day for snow in Sioux City. The latest day for measurable snow ever in Sioux City came on May 28, 1947.
In a release, South Dakota Department of Transportation Cabinet Secretary Darin Bergquist says crews are preparing to keep highways open as much as possible.
“Motorists need to keep updated with the latest weather and road conditions," Bergquist said.