textproduct: Sioux Falls

KEY MESSAGES

- Locations east of I-29 may see a light wintry mix Thursday morning. Any snow or ice accumulations would be very light. - Mild temperatures and gusty northwest winds Thursday will lead to elevated fire danger near and west of I-29.

- Snow showers and strong winds develop Thursday night into Friday. While snow amounts alone would produce only minor impacts to travel, strong winds in excess of 40-50 MPH with any falling snow could significantly reduce visibility.

- Below normal temperatures are expected this weekend into early next week with the potential for near-advisory level wind chills at times.

DISCUSSION

Issued at 345 AM CST Wed Jan 14 2026

TODAY-THURSDAY: A brief cool-down today in the wake of a broad trough swinging through the Upper Midwest. Strongest winds today should be this morning, decreasing with an approaching surface ridge through the afternoon. As the ridge slides east later in the night, warm advection and an increasing southerly flow will bring an increase in clouds, steady to rising temperatures and perhaps a few flurries before daybreak Thursday.

Low chances (20-30%) for light precipitation will continue near and east of I-29 into Thursday. With surface temperatures still below freezing early in the day, a light wintry mix is possible through the morning. HREF shows less than 20% probability for measurable freezing rain east of Brookings to Sioux Falls, with pockets of 20-30% probability for 0.1" of snow across our far eastern counties through noon Thursday. However, temperatures in these areas are expected to climb above freezing Thursday afternoon, so impacts from any light ice/snow accumulation should be brief.

THURSDAY NIGHT-FRIDAY: This period will bring the greatest impacts to travel across the region, as a couple of waves slide through the northern Plains in northwest flow. The lead wave and associated cold front push south Thursday evening. Saturation is still somewhat lacking with this lead wave, but could see spotty rain/snow showers develop north of I-90. The trailing wave and secondary cold front push southeast during the day Friday, with timing still varying from morning to afternoon among the various models. This cold front will bring the greater travel impacts with better saturation and a weak convective layer bringing an increased potential for snow showers/horizontal convective rolls (HCR). QPF amounts are fairly light, averaging less than 0.05" across the models for most locations. However, even these light amounts could result in up to an inch of fresh snowfall, with areas from the Coteau des Prairies in east central South Dakota into portions of southwest Minnesota seeing moderate (40-60%) probability of exceeding an inch of snowfall.

Of greater concern than the snowfall alone is the increasing northwest winds which will accompany this system. Periods of 40-50+kt winds at 850mb (roughly 3500ft AGL in our region) develop by Thursday afternoon-evening and persist through the day Friday. Could begin to tap into these stronger winds behind the lead cold front Thursday evening, but this appears more likely with the second shot of cold advection later Thursday night into Friday as a weakly unstable layer develops above 850mb. Locations west of the James River show the highest probability of 850mb winds exceeding 50kt, and as a result, confidence is highest that this area could see warning-level gusts as high as 60 to 70 mph at times late Thursday night through Friday. Have issued a High Wind Watch from Jerauld to Douglas/Charles Mix Counties and west. Later shifts will need to further evaluate the risk for warning level winds farther east. The NAM is more robust with the depth of the convective mixed layer and in turn the strength of the winds atop this convective layer. However, this currently seems to be at the extreme and thus confidence in 60+mph gusts along and east of the James is lower.

Regardless of whether winds reach warning level or just higher end advisory, these winds combined with the anticipated snow showers could result in significant visibility reductions in snow squalls or HCRs at times. May need winter headlines as well to cover the reduced visibility potential in blowing snow, but since we are starting off with bare ground or an unblowable snow pack, visibility issues will be directly tied to falling snow. Want to get a better handle on the snow shower timing and location before issuing these headlines.

SATURDAY ONWARDS: Below normal temperatures will dominate the weekend into early next week, with breezy daytime winds over the weekend bringing continued potential for drifting/minor blowing of the fresh snow. Nighttime/early morning wind chills fall into the teens below zero, with a potential for advisory level wind chills in portions of east central SD/southwest MN Saturday into early Monday. A brief shot of weak warm advection Sunday could produce some very light snow/flurries, but otherwise dry conditions are expected to prevail.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1129 AM CST Wed Jan 14 2026

VFR conditions expected to continue through this afternoon and evening. Very spotty rain/snow/wintry mix showers look to swing through the area late tonight into tomorrow morning, but confidence was not high enough to include in the TAFs at this time due to the expected scattered nature of any activity. Should any shower run through your site of interest, there would likely be a brief drop to MVFR conditions.

Northwesterly winds will continue to diminish through this afternoon, with winds becoming light and variable overnight. Winds pick up once again through tomorrow morning as a strong cold front moves across the area. There will also be some LLWS concerns tomorrow morning mainly at KHON before the stronger winds there mix down to the surface just after this TAF period.

FSD WATCHES/WARNINGS/ADVISORIES

SD...High Wind Watch from late Thursday night through Friday afternoon for SDZ050-052-057-058-063-064. MN...None. IA...None. NE...None.