textproduct: Sioux Falls

KEY MESSAGES

- Light snow continues to push southeast tonight. Total snowfall amounts of a dusting to 1.5" possible.

- Additional light snow arrives after daybreak Wednesday, followed by 40 to 60 mph winds through the afternoon. Considerable questions continue on potential blowing snow risks, but expect some travel difficulties.

- Life-threatening cold temperatures move in for the end of the week and start of the weekend. Wind chills as low as -30 to -45 are possible Friday morning. An extreme cold watch has been issued for Friday morning.

DISCUSSION

Issued at 200 PM CST Tue Jan 20 2026

THIS Afternoon: Shortwave energy continues to cross the western Dakota this afternoon. Lift has been weaker than previously expected, with a considerable amount of dry air still to overcome. Only reports of snow thus far as of 1pm have been over western and north central South Dakota. Short term CAMs seem to be picking up on this trend, generally delaying the onset of snow in most areas, and lowering snow amounts.

TONIGHT: The aforementioned wave and associated warm advection shifts east of the CWA by 03Z, leaving accumulations of a dusting to an inch (perhaps very isolated higher totals along I-90 east into Minnesota). A few CAMs indicate very light snow to flurries move into the central South Dakota areas after 03Z, gradually dissipating as they reach I-29. Behind the precipitation winds will remain light and variable with temperatures falling into the single digits to teens.

WEDNESDAY: Models remain in strong agreement pushing another compact shortwave through the Dakotas during the day on Wednesday. As mentioned by the previous discussion, we'll see multiple hazards through the day. First being a narrow band of light to moderate snow tied to the arrival of strong dPVA and focused warm advection that will slide from west to east through the morning hours. This precipitation may produce a quick dusting to 1" of snow along or north of I-90. The biggest concern remains the arrival of a potent arctic front that will move through late in the morning. A strong SPG will form behind the passage of this front pushing sustained winds towards the 30 mph mark, however the strong low-lvl cold advection will further enhance low-lvl lapse rates and make the mechanical transfer of 50+ knot winds at the top of the mixed layer much easier to push to the surface. The result may be occasional gusts between 45 and 65 mph through the afternoon. A high wind warning was considered, but confidence not high enough on this shift to issue given only a handful of models showing this potential.

IMPACTS WEDNESDAY: The most challenging aspect of Wednesday's forecast is the impact of the winds on what snow may fall today, but also falls in the morning. Most blowing snow tools suggest that we'll begin to some impacts with up to 1" of new depth, but more higher end and widespread impacts start at 2". The poor performance of today's snow and then modest impact of Wednesday morning snow, and much less coverage of post frontal convection leaves some doubt in my mind on the overall extend of impact. That said, will issue an advisory for areas where my confidence is higher on additional meaningful snow accumulation and current snow depth remains around 1". Model visibility progs do indicate occasional visibility drops through the afternoon, but anticipating fairly scattered poor conditions. Areas of the ridge of SW MN and northern IA will stand the greatest potential for blizzard conditions if today's snow climbs higher. Wind advisories will be issued further south. The areas near I-90 pose the greatest potential of being switched to winter weather related headlines if we can see a quick 1-2" of snow.

THURSDAY-FRIDAY: The coldest air of the Winter season will begin to move in on Thursday as an arctic front on the leading edge of a 1053 mb high passes through during the day. The passage of this front may bring both occasional flurries, but also 30-35 mph gusts leading to additional blowing snow concerns.

Extremely cold low-lvl temperatures plunge into the Plains into the weekend. Air temperatures at 925 and 850 mb both sit at the edge of climatology centered around late January, which result in overnight lows by Friday morning in the teens to even 20s below zero. Surface winds are likely to remain elevated in Friday morning as the center of the surface high only reaches central South Dakota by mid-day. This results in wind chill values approaching -30 to -45F, coldest along the higher ridge elevations. As a result will issue an extreme cold watch for most of the CWA. Temperatures will rise very slowly Friday, with dew points also plummeting under the surface high.

SATURDAY-TUESDAY: Light winds and clearing skies will allow overnight lows to again drop similarly to Friday morning, however winds will be much lighter in nature. This results in a highly variable wind chill forecast, which has most of the area remaining near advisory criteria and not warning criteria. Mid- lvl clouds increase from the southwest late Saturday into Sunday as a weak wave moves through the Plains, however dry conditions are expected. Quiet and colder than normal temperatures are favored into the new work week as the long wave trough remains centered over the Great Lakes.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1041 PM CST Tue Jan 20 2026

Light snow continues to move southeast late tonight. Still seeing some MVFR to IFR conditions with both the snow and the stratus. Snow tapers off overnight, with some lingering MVFR and lower stratus. Additional snow moves into the James River Valley by 13-14z, trekking east through the morning and early afternoon, mainly along/north of I-90. New snowfall amounts of an inch or less for most, with isolated higher amounts possible. Expect MVFR to possibly IFR conditions with this second area of snow. May see additional categorical restrictions through the afternoon due to blowing snow for areas which have seen an inch or more of new snow.

Winds quickly strengthen through the morning hours from west to east, with gusts by late morning/early afternoon around 40 to 45 knots (or more). Winds remain strong through the afternoon and early evening, tapering down Wednesday night. Direction largely out of the west to northwest.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory from 10 AM to 6 PM CST Wednesday for SDZ062-067- 070-071. Extreme Cold Watch from Thursday evening through Friday afternoon for SDZ038>040-052>056-058>062-065>067-069>071. Winter Weather Advisory from 10 AM to 6 PM CST Wednesday for SDZ056. Winter Weather Advisory from 7 AM to 6 PM CST Wednesday for SDZ038>040-052>055. Wind Advisory from 7 AM to 6 PM CST Wednesday for SDZ050- 057>061-063>066-068-069. Extreme Cold Watch from Thursday evening through Friday afternoon for SDZ064-068. MN...Wind Advisory from 10 AM to 6 PM CST Wednesday for MNZ098. Extreme Cold Watch from Thursday evening through Friday afternoon for MNZ071-072-080-081-089-090-097-098. Winter Weather Advisory from 10 AM to 6 PM CST Wednesday for MNZ071-072-080-081-089-090-097. IA...Wind Advisory from 10 AM to 6 PM CST Wednesday for IAZ001- 012>014-020>022-031-032. Extreme Cold Watch from Thursday evening through Friday afternoon for IAZ001>003-012>014-020>022-031-032. Winter Weather Advisory from 10 AM to 6 PM CST Wednesday for IAZ002-003. NE...Wind Advisory from 10 AM to 6 PM CST Wednesday for NEZ013-014. Extreme Cold Watch from Thursday evening through Friday afternoon for NEZ013-014.