textproduct: Sioux Falls

KEY MESSAGES

- Mild temperatures continue through the week ahead, as much as 15-30 degrees above normal region-wide today. A few record highs may be tied or broken, mainly in areas south of I-90.

- Low afternoon humidity levels and breezy winds in the warmest areas south of today will result in elevated fire danger today.

- Quiet weather will prevail through Wednesday, with light rain and/or snow expected Wednesday night into Thursday.

DISCUSSION

Issued at 245 AM CST Mon Feb 9 2026

A mild start to the day with early morning temperatures in the upper 20s to mid 30s already near to above normal highs for this time of year. Relatively thin high clouds are widespread south of Highway 14, with thicker mid-high clouds along and north of the Highway 14 corridor. Models continue to project the thicker clouds expanding southward with an advancing wave and cool front today, reaching areas as far south as Platte-Sioux Falls-Jackson MN by early afternoon. The clouds will limit warming north of this line with highs expected to top out in the upper 40s-lower 50s, but a very dry sub-cloud layer below 12kft AGL should keep any sprinkles at bay.

Expect to see a fairly tight temperature gradient across the southern edge of the thicker clouds, with much warmer readings toward the lower Missouri River Valley (Pickstown/Fort Randall Dam to Sioux City) where highs could approach 70F. Lowest confidence in high temperatures lies across the aforementioned gradient where faster cloud increase would hold readings cooler, but a slower increase could allow for greater warming. As the forecast stands now, Sioux Falls will be close to tying the existing record high of 58F (1977). The greater chances for breaking existing records looks to be from Vermillion (65F in 1996) to Sioux City (62F in 1954), with a few other COOP sites south of Highway 18 also threatening.

With the cool front sagging south, a slack pressure gradient should keep our winds in check today with peak gusts generally remaining less than 25 mph. That said, locations ahead of the front could still mix some of the drier air aloft to the surface as the temperatures warm into the upper 50s and 60s, leading to minimum relative humidity values as low as 20-35 percent for most areas south of I-90 today. Thus still looking at elevated fire danger, but potential for Red Flag conditions looks low, 20 to locally 30% per latest HREF.

Cooler but still mild temperatures settle in for Tuesday and Wednesday with highs mostly in the 40s and dry conditions expected. Still looking at a broad wave sliding across the region Wednesday night into Thursday which brings a 40-50% chance of light rain or snow, though latest model soundings hold onto drier air even into the evening, so greatest chances are focused on later Wednesday night-Thursday morning, which would include the Thursday morning commute. Temperatures aloft remain cool enough to maintain snowflakes, so rain/snow at the surface will hinge on temperatures within the lowest several hundred feet AGL. With this in mind, better chances for light snow accumulation are across the higher elevations of southwest Minnesota, perhaps as far west/south as Brookings or Madison SD to Worthington/Jackson MN, though even these areas are likely to remain below 1 inch accumulation with ensembles showing a 20-30% probability of exceeding 0.10" liquid. Highs Thursday could depend on how late precipitation lingers through the day, especially across our northeast counties where light snow is more probable. NBM forecast high is several degrees above the 50th percentile in this area, so nudged Thursday highs closer to that 50th percentile across the northeast portions of the forecast area.

Precipitation chances Friday into the upcoming weekend are a bit more murky, though models seem to be trending toward a more dominant southern stream system moving through the central Plains, with perhaps some light precipitation chances brushing southern parts of our forecast area during the first half of the weekend. Greater confidence that temperatures will remain on the warm side of normal with 850mb temperatures above the 70th-80th percentile of climatology into early next week.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 545 AM CST Mon Feb 9 2026

Mid to high level clouds will be abundant through this evening, but conditions remain VFR with clouds mostly at or above 10kft AGL. Some indications of MVFR ceilings sagging into portions of southwest Minnesota late in this TAF period, but low confidence in whether these clouds expand as far west as KBKX/KFSD.

Southwest to west winds ahead of a cool front may gust as high as 20kt. However, better chance for occasional gusts 20-25kt developing in the north-northwest flow behind the cold front after sunset.

FSD WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None. IA...None. NE...None.