textproduct: Sioux Falls

KEY MESSAGES

- Near to below average temperatures will continue for the remainder of the work week, with highs in the 50s to low 60s. - Rain returns late tonight and continues into Thursday afternoon. Rain totals will range from a trace to a couple tenths along Highway 14, to 0.25 to 0.75 inches near and south of I-90. Isolated pockets up to 1 inch are possible along and south of Highway 20.

- Chances for frost Friday night into early Saturday morning as lows fall into the mid to low 30s. Areas east of the James River are most likely to see frost.

- Dry conditions and warmer temperatures return through the weekend into early next week with highs back above normal.

DISCUSSION

Issued at 256 PM CDT Wed Oct 14 2026

Bufkit soundings indicate a persistent, shallow layer of low stratus clouds for the remainder of today. Clouds will likely limit our highs somewhat from what the NBM loaded, adjusted down slightly with a blend of NBM/CONSShort. Overnight lows will fall to the 40s.

Meanwhile a southern stream upper trough located over the central Rockies will work east through the rest of today. Early this evening the trough and associated surface low will eject out onto the central plains and then accelerate northeast. As it does so scattered showers and isolated thunderstorms will form over western Nebraska and Kansas. These will move northeast with the system and begin to impact south central South Dakota between roughly 6 and 8 pm CDT tonight. Scattered showers and storms should be in the Sioux Falls area roughly between 10 pm and midnight. As the surface low skirts just to the south of the CWA early Thursday morning showers and storms become more numerous, especially for areas along and south of I-90 and into northwest Iowa. Here a few stronger storms may produce more frequent lightning and isolated pockets of heavy rain. Severe weather is not anticipated.

Late Thursday morning into the afternoon a northern stream upper trough and surface low will move into central Canada. A cold front will form off of this low and will pass through the region from the northwest to the southeast. Behind the front storms end and clouds begin to break up Thursday afternoon and into the evening. Simultaneously the northern stream wave extends south, eventually phasing into the southern stream wave. This will result in an amplifying effect as the now deep amplitude upper trough tightens and narrows. Thursday evening the LLJ responds to this amplification by ramping quickly up to 50+ mph. These strong winds will mix down resulting in surface gusts of 30 to 40 mph. Occasional gusts as high as 45 mph are also possible over central South Dakota. Our western most counties may briefly approach Wind Advisory criteria late Thursday evening, but guidance is not in good agreement at this time. As such, have opted to wait on a wind headline at this time. Winds generally decrease as you move to the east but will remain gusty at 25-35 mph. The stronger winds gradually move east overnight into Friday morning. Additional wind concerns will be along the lee side of Buffalo Ridge where additional gusts of 40+ mph are possible.

As far as rain totals are concerned the latest guidance has trended down a little. Areas along Highway 14 and north will only see a trace up to a tenth or two. As you move south toward I-90 totals increase to a couple tenths up to 0.30 inches. For areas along and south of I-90 guidance indicates rain totals ranging from 0.25 to 0.75 inches, with highest totals focused over northwest Iowa. Areas along and south of Highway 20 may see isolated pockets up to 1 inch.

Breezy winds continue into early Friday afternoon before gradually tapering off Friday evening. Friday highs will be on the cool side of climatology thanks to strong CAA on northwesterly winds, in the low to mid 50s. Skies clear through the day and remain clear through the overnight. This will allow for maximum radiational cooling, resulting in low temperatures by sunrise Saturday in the low to mid 30s. Area of frost are possible, mainly west of the James River Valley. Clear skies continue for Saturday as winds turn southerly and usher in warmer air. Highs will climb into the low to upper 60s, warmest over central South Dakota. No concerns at this time for frost Saturday night into Sunday morning with lows in the 40s. Sunday will be another mostly clear day with continued WAA. Highs will climb into the mid to upper 60s with lows in the 40s. Dry conditions and highs in the 60s and low 70s continue into the first half of next week.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1253 PM CDT Wed Oct 14 2026

MVFR ceilings are expected to prevail over most of the CWA through the duration of this period. Soundings indicate a persistent, shallow layer of low stratus clouds at or around 1500 to 2000 ft AGL. Scattered showers and isolated thunderstorms move in from the southwest late this afternoon and into the evening. After midnight storms are expected to increase in coverage over the majority of the CWA. Ceilings and visibility may further degrade down to IFR to LIFR as the main upper wave passes through beginning around sunrise. A few isolated storms may be a little stronger producing lightning and brief periods of heavy rain, mainly along and south of I-90. Severe weather is not anticipated. Rain will gradually taper off from northwest to southeast Thursday afternoon.

FSD WATCHES/WARNINGS/ADVISORIES

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