textproduct: Sioux Falls

KEY MESSAGES

- Rain expands tonight into early Thursday morning, tapering off from west to east Thursday afternoon. Rain totals increase from north to south from around a tenth of an inch near US Highway 14 to around 0.75" near US Highway 20. Isolated higher amounts possible along/south of US Highway 20.

- Strong northwest wind gusts 30 to 45 mph behind the rain Thursday afternoon into Friday morning. Gusts around 50 mph expected across south central South Dakota and possible (30- 40% chance) along the Buffalo Ridge.

- Moderate to high (50% or greater) chances of frost for most of the area Friday night into Saturday morning, highest near and east of Interstate 29 with temperatures around or below 36 degrees F. Low to moderate (40% or less) chances of a freeze (temperatures near 32 degrees F) east of I-29.

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

UPDATE

Issued at 922 PM CDT Wed Oct 14 2026

No significant chances to the precipitation chances and coverage this evening into Thursday afternoon, with minor adjustments to the timing and coverage. Soundings show a bit less instability, so expect thunderstorms south of I-90 to be more isolated and infrequent than previous forecast.

Hi-res models and other guidance this afternoon/evening has trended up with strong winds behind the rain and surface cold front moving east tomorrow afternoon and evening. Duration of gusts may continue through daybreak Friday as strong lower level CAA and stronger LLJ track east. Soundings show gusts of 30 to 50 mph mixing down, strongest west of the James River Valley and also along the higher elevations of the Buffalo Ridge. RAP/HRRR/GFS have the strongest winds - due to mixing a bit deeper and showing stronger winds at the top of the mixed layer than the NAM. Latest NBM reflects this increase, but still may be too low. Further adjustments may be needed as more of the 15.00z and later guidance comes in. Have issued a Wind Advisory for south central SD Thursday afternoon and night, where confidence is highest in gusts 45-50 mph at this time. Winds still look to taper down during the afternoon and evening.

Looking ahead, ensemble probabilities for a frost (temperatures near and below 36 degrees F) and a freeze (temperatures near 32 degrees F) are increasing for Friday night into Saturday morning. Probability remains highest near/east of I-29.

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 /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1036 PM CDT Wed Oct 14 2026

Initial push of rain is moving northeast from between KHON/K9v9 to KFSD/KYKN and to just north of KSUX. Additional development is on-going across NE and is expected to fill in as it lifts north overnight. Very isolated storms remain possible closer to and south of the US Hwy 20 corridor through Thursday morning. Rain tapers off through the late morning into the afternoon hours from west to east.

Lower VFR conditions and MVFR conditions into tonight will give way to MVFR and IFR conditions with rain and lower stratus. Conditions improve back to VFR toward Thursday afternoon through the rest of the period.

Main focus after precipitation will be the increasing northwesterly winds Thursday afternoon and continuing into Friday morning. Gusts of 25 to 35 knots are expected by the mid to late afternoon hours, with gusts to 40 knots for south central SD. Could see some locally stronger gusts for the higher elevations of the Buffalo Ridge as well.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory from 3 PM Thursday to midnight CDT Thursday night for SDZ050-052-057-058-063-064. MN...None. IA...None. NE...None.