textproduct: Sioux Falls

KEY MESSAGES

- Despite light winds, wind chills -20 to -30F will be common over the area through mid-morning, coldest north of I-90.

- Another night of dangerous cold is likely Sunday night, with a moderate to high (40-90%) chance of wind chills of -25 or colder mainly northeast of a Huron to Sioux Falls to Storm Lake line.

- Less cold temperatures for Monday onward, though still below normal for the last week of January. Light snow chances late tonight-Sunday, and again Tuesday night-Wednesday. Low (<20%) probability of snowfall reaching 1 inch in either period.

UPDATE

Issued at 535 AM CST Sat Jan 24 2026

Advisory-level wind chills of -25F or colder looked to become a little more widespread and persistent over our western counties as light southerly flow develops this morning, so expanded the Cold Weather Advisory near/west of a Mitchell to Wagner line through 9 AM. Conditions remaining marginal over the remainder of southeast South Dakota and additional expansions are not anticipated.

DISCUSSION

Issued at 258 AM CST Sat Jan 24 2026

TODAY-SUNDAY NIGHT: Arctic high pressure moving through the Upper Mississippi Valley and into the western Great Lakes today, allowing a modest southerly flow to develop through the morning. Winds may begin to increase just enough ahead of the rise in temperatures to see advisory level wind chills (-25F or colder) persist through 9-10 AM. Cannot rule out a brief dip to colder wind chills toward south central South Dakota as the winds begin to pick up prior to daybreak, or lingering an hour beyond the current expiration, but overall the advisory remains on track.

Weak warm advection will help temperatures recover above zero in most areas by this afternoon, with readings dropping back into the single digits below zero tonight. A compact surface low looks to develop in southwest-south central South Dakota tonight in response to a mid-upper level wave dropping southeast across the Dakotas. NBM maintains a dry forecast with this feature, but deterministic models in fairly good agreement in producing some light QPF across our South Dakota counties late tonight through midday Sunday. Coordinated with neighboring offices to introduce some low-moderate (20-40%) pops and light snow accumulation to areas mainly west of I-29. While ensemble probabilities support these chances for measurable snow, probabilities are generally very low (<10%) that amounts will reach 1 inch. May have to watch northwest portions of the forecast area, however, as the HREF does indicate a small pocket of higher probabilities for near/west of the James River Valley (Huron/Mitchell).

Another shot of colder air builds in behind this wave for Sunday night, bringing our next period of advisory level wind chills for later Sunday night into Monday morning. Probabilities remain moderate to high (40-90%) that areas northeast of a line from Huron-Sioux Falls-Storm Lake will see wind chills below -25F Monday morning, with a low (~20%) probability of wind chills reaching -35F in portions of southwest Minnesota.

MONDAY-WEDNESDAY: After bottoming out in the single digits and teens below zero Monday morning, temperatures quickly recover through the day Monday. This could be the warmest day of the week ahead with highs from the teens in southwest Minnesota to near/just above freezing in south central South Dakota. A dry cool front moves through Monday night, followed by another weak wave later Tuesday night into Wednesday. This latter wave will have a bit more moisture to work with, but model differences in the track of the wave are keeping pops on the low side for now. The broader ensembles showing 30-50% chance of measurable snow occurring on Wednesday, with low (~20%) probability of amounts nearing an inch in portions of southwest Minnesota.

THURSDAY-FRIDAY: Low confidence in temperatures as we head into the final days of January 2026, with NBM temperature spreads climbing to as much as 30-40 degrees between the 10th and 90th percentiles by Thursday and Friday. Somewhat higher confidence that this period remains dry with <20% probabilities of seeing measurable precipitation.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 535 AM CST Sat Jan 24 2026

VFR conditions and relatively light winds will prevail through this period, with a couple of exceptions.

First, areas west of I-29 will see occasional southerly gusts 15-20kt during the late morning through sunset today.

Second, an approaching wave will begin to produce MVFR level clouds late in this period. At this time, confidence is not high enough to include MVFR ceilings, but did include SCT020 at KHON and KFSD to indicate potential timing. Eventually spotty -SN may accompany these lower ceilings, but this should hold off until after this TAF period.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Cold Weather Advisory until 9 AM CST this morning for SDZ038>040-050-052>059-063-064. MN...Cold Weather Advisory until 9 AM CST this morning for MNZ071- 072-080-081-089-090-097. IA...None. NE...None.