textproduct: Sioux Falls

KEY MESSAGES

- Wintry precipitation expected north of I-90 Wednesday night into Thursday. A bigger threat for sleet and freezing rain than snow. Winter Weather Advisory for Highway 14 corridor and SD Highway 34/MN Highway 30.

- A much needed rainfall will move into the area Wednesday and continue into Thursday morning. Much of the area will see a half an inch to an inch of rain/total liquid precipitation.

- Isolated thunderstorm potential late Thursday night early Friday morning in mainly northwest IA. Severe weather unlikely but some small hail would be possible.

- Friday is a tricky day with the potential for freezing rain and sleet. The better chances for snow should be mostly northwest of the area. Enough of an icing threat that some minor to moderate impacts will be possible.

UPDATE

Issued at 1015 PM CDT Tue Mar 31 2026

Thermal profiles continue to fluctuate for the first wave of our return to winter, with latest NBM and several CAMs coming in 3-5F warmer for highs on Wednesday than previous forecast. Will begin the day with a fairly dry sub-cloud layer below 10kft AGL, but as the wave approaches and lift increases, clouds will thicken and precipitation coverage will likewise increase. Easterly low level winds are not typically favorable for strong boundary layer warming, especially when dynamic wet-bulb cooling will also be working against extensive warming. Thus will stick closer to the previous forecast for highs, ranging from 35-40F for most areas north of I-90 to mid-upper 40s in northwest Iowa. Locations which see precipitation in the morning will more likely be very light snow, but with the dry layer to overcome, only trace amounts should be seen. As precipitation increases in coverage through the day, type should be more predominantly rain with perhaps a very wet snow in our northern areas.

Wednesday night into Thursday continues to be the greatest period of concern with regard to wintry weather impacts with freezing rain and/or sleet remaining more likely across our northern two tiers of counties than substantial snow. Given the latest data, a little concerned about seeing icing expand into the Madison and Flandreau areas, so expanded the Winter Weather Advisory into Lake and Moody counties, but otherwise no headline changes at this time.

DISCUSSION

Issued at 144 PM CDT Tue Mar 31 2026

Cool high pressure moves by to the north tonight which will allow easterly flow at the surface to develop. With winds remaining at about 5 to 15 mph through the night, temperatures should not drop off significantly, falling into the upper 20s to lower 30s in most locations.

Moisture aloft increases through the day on Wednesday while low level moisture lags a bit. By afternoon the low level moisture starts to creep into areas west of I-29. Upper level support moves into the area by late Wednesday afternoon with some weak destabilization which should lead to scattered showers. Given expected surface temperatures, all rain is anticipated although some snow would be possible north of I-90 and maybe a bit of a mix closer to highway 14 towards sunset. At least through sunset amounts north of I-90 will likely be limited by this lower level dry air as the lift and precipitation slowly overcome it.

The strongest lift will be roughly 10 pm Wednesday night through 6 am Thursday morning. Weak instability south of I-90 aids the strong lift as the upper level wave moves from central NE into southwest MN during this time. The biggest challenge during this time will be surface temperatures which will dictate the rain vs. freezing rain, but also the warmest T aloft which will dictate freezing rain vs. sleet. Currently much of southeast MN and nearby locations will see the best chance for the warm layer aloft and surface temperatures creeping down to 30-32 degrees. The latest Nam and HRRR both indicating about 0.25" to 0.50" of freezing rain in these locations. Given the warm ground temperatures, much of the affects may end up on elevated surfaces, which would include power lines. While winds are not excessive, gusts of 15 to 20 mph look likely. Given some confidence that surface temperatures will remain just above 32 with the potential for latent heat release with moderate rainfall and the latest Nam and Consshort all indicating temperatures hovering between 32 to 34 for much of the area most susceptible for icing.

Precipitation chances will linger through Thursday afternoon, but anything that falls Thursday afternoon will be on the lighter side.

A break in activity is expected late Thursday afternoon into the early overnight hours before the effects of the next wave spread into the area. Late Thursday night, elevated instability (CAPE values 500-1000 J/kg) moves into in northwest IA, far southeast SD and northeast NE late Thursday night into Friday morning. While severe weather is not expected, if that amount of instability does come to fruition, some dime sized hail would be possible with the freezing level around 9000 ft.

After the morning elevated convective push, the next trend to keep an eye on will be dry slotting. The models are hinting that areas near and east of I-29 may end up with little in the way of saturation aloft through the afternoon and without much convective help, these locations may remain mainly dry during this time. Will keep the chance for precipitation in however as confidence on a total dry slot shut down of precipitation is not there. The main concern with this system will be the potential again for freezing rain and sleet. Confidence definitely not high enough for any headlines, especially given the Wednesday night/Thursday system, but something to keep an eye on trends. Will also watch the trends of some strong lift in central SD which would likely be mostly snow. This would affect especially the Chamberlain and Huron locations.

Cold and windy on Saturday with a lingering chance for light snow. Generally looking at highs in the 30s to lower 40s and wind chills in the teens.

Northwest flow aloft remains in place Sunday through Tuesday with near seasonal to below normal temperatures expected. The chances for precipitation remain minimal during this time.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1202 AM CDT Wed Apr 1 2026

VFR conditions will begin the period, but conditions will slowly deteriorate after 12-14Z Wednesday as scattered light snow/rain begins to develop. MVFR conditions begin to expand after 18-20Z Wednesday afternoon as rain/snow becomes more widespread, with ceilings lowering to IFR after sunset. Precipitation type looks to be mainly rain through the afternoon/evening, except along the Highway 14 corridor where there is a low (20-30%) chance of a wintry mix after sunset. This would range from rain/snow at KHON, to a potential for light icing from around KBKX eastward toward KMML/KTKC.

North-northeast winds swing to the east late tonight with occasional gusts 20-25kt after daybreak Wednesday through the end of this TAF period..

FSD WATCHES/WARNINGS/ADVISORIES

SD...Winter Weather Advisory from 10 PM Wednesday to 6 PM CDT Thursday for SDZ038>040-055-056. MN...Winter Weather Advisory from 10 PM Wednesday to 6 PM CDT Thursday for MNZ071-072-080-081-097. IA...None. NE...None.