textproduct: Sioux Falls

KEY MESSAGES

- Mild temperatures and gusty northwest winds today will lead to elevated fire danger this afternoon, highest west of the James River Valley where afternoon gusts 40-50 mph are expected.

- Snow showers and strong winds develop after midnight tonight through Friday. While snow amounts alone would produce only minor impacts to travel, strong winds in excess of 45-55 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 430 AM CST Thu Jan 15 2026

TODAY-THIS EVENING: Early morning temperatures have begun to rebound as south-southwest winds develop in the wake of a departing surface ridge. Today will end up being the warmest of this forecast period as warm advection and increasing southwest to northwest winds help temperatures climb into the mid 30s east to upper 40s west. Strongest winds during the afternoon and evening should reside toward central South Dakota/west of the James River Valley, where gusts 40 to 50+ mph are expected to develop. Have issued a Wind Advisory for noon-midnight to cover this initial uptick in winds. As for precipitation chances, while mid level clouds will be expansive across the area in response to the warm advection, dry air below 10kft AGL will limit potential for precipitation to reach the ground. Cannot rule out spotty flurries/sprinkles (some of which may freeze on contact). However, more than trace amounts are not expected.

LATE TONIGHT-FRIDAY: This remains the primary focus of this forecast period, and the main features of the going forecast remain on track. Looking at a couple of waves and associated cold fronts dropping through the region. The first weaker wave will slide through by later afternoon-evening and will bring the initial increase in wind speeds as mentioned above. The stronger wave and push of cold advection will follow later tonight into Friday. The strong cold advection will support deeper mixing, with pockets of 50+kt winds at 850mb and even stronger winds above that level supportive of at least brief gusts reaching 60+mph. Ensembles continue to support areas west of the James River as more favored to see these stronger gusts, with moderate (40-60%) probabilities of 850mb winds exceeding 50kt, highest in Gregory County. After coordination with neighboring offices, opted to leave the High Wind Watch in place for now, mainly due to lingering uncertainty in how far east of the Missouri River the warning-level winds will extend.

That said, while confidence is high that we will see advisory level winds at least as far east as the I-29 corridor Friday, feel the potential for greater impacts would result from the combination of these winds and narrow snow bands which are expected to develop. Greatest uncertainty remains centered on where these narrow snow bands will set up, and whether they persist over narrow zones or be transient (i.e. will we see narrow bands of 2+ inches of snow or broader coverage of less than an inch).

Ultimately feel a Winter Weather Advisory would better cover the impacts of brief but potentially significant drops in visibility due to falling and blowing snow. However, with lower confidence in snow shower coverage and snowfall amounts atop bare ground, decided to give the day shift another look before issuing any winter headlines.

FRIDAY NIGHT ONWARD: Colder temperatures and periods of near advisory level wind chills will dominate the upcoming weekend, with breezy daytime winds also presenting a potential for patchy drifting/blowing snow if snowfall amounts top an inch or so on Friday. Temperatures may be on a bit of a roller coaster next week, with a brief reprieve from the coldest air Sunday before another arctic front brings a reinforcing push of cold air for Monday. This cycle could repeat again Tuesday-Wednesday, though currently less agreement on the timing of these temperatures fluctuations at this range.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1155 AM CST Thu Jan 15 2026

Scattered rain and snow showers look to develop this afternoon and evening. Activity will be patchy and quick-moving in nature, but there was enough confidence to at least add PROB30 groups to both KFSD and KHON this evening for this potential. A better chance of snow showers arrives late tonight into tomorrow morning, bringing at least MVFR conditions to the terminals whenever snow is falling. However, narrow heavier bands of snow will set up as well, though confidence is low in the exact location of where these bands set-up. If underneath one of these heavier bands, then visibilities could drop lower than 1 mile in blowing snow.

Winds will be picking up through the afternoon especially along and west of the James River, where gusts could exceed 40 kts at times. These stronger winds will spread east through late tonight into the day on Friday. On Friday, look for gusts reaching the 50-55 kt territory mainly in south-central South Dakota.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory until midnight CST tonight for SDZ038-050-052- 053-057>059-063>065-068. High Wind Watch from late tonight through Friday afternoon for SDZ050-052-057-058-063-064. MN...None. IA...None. NE...None.