textproduct: Sioux Falls

KEY MESSAGES

- Rain coverage expands through mid-morning, then tapers off northwest to southeast through this afternoon. Rain totals range from around a tenth of an inch near US Highway 14 to around 0.75"/locally higher near Sioux City to Storm Lake.

- Strong northwest wind gusts 35 to 45 mph develop behind the rain this afternoon into Friday morning. Gusts around 50 mph are expected across south central South Dakota, and possible (30-40% chance) along the Buffalo Ridge.

- Moderate to high (60% or greater) chances of frost for most of the area Friday night/early Saturday, highest near and east of Interstate 29 with temperatures 36 degrees F or colder. Low to moderate (50% or less) chances of a freeze (temperatures at or below 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 425 AM CDT Thu Oct 15 2026

A more active 24-48 hours ahead, with a couple potential hazard periods for risks not related to precipitation following today's rain.

Before these hazards arrive, periods of rain will continue through this morning as a southern stream low kicking out of the central Rockies opens up and phases with a northern stream trough diving southeast into the northern Plains. It looks as though by late morning-midday, rain will be most widespread across southeast portions of the forecast area, with a dry slot ahead of the northern stream wave working into northwest parts of the CWA. This drying will push southeast and bring an end to rain from northwest to southeast through the afternoon, however additional light wrap-around showers may move across northern and western parts of the forecast area tonight, mainly focused toward southwest Minnesota. Any additional rainfall with this activity would be very light.

The dry push and associated strong cold advection will bring an increase in northwest winds as the rain winds down this afternoon. Strongest winds, with gusts nearing 50 mph at times, are expected in central South Dakota, including a few counties in our far western forecast area. The evening shift issued a Wind Advisory starting at 3 pm today for this area, running through midnight. This end time is on track for Jerauld to Douglas counties. However, the stronger winds look to persist through the Missouri River Valley counties beyond midnight, and have coordinated an extension for our far southwest 3 counties through 4 AM CDT. Some models show a secondary surge of cold advection late tonight into Friday morning, with 850mb winds increasing to 50kt. This could produce a broader area of 45-50 mph wind gusts across southeast SD/southwest MN from prior to sunrise through midday Friday. Neighboring offices coordinated to hold off on this additional advisory until confidence in location/timing increase.

Winds gradually decrease through the day Friday as surface high pressure moves east across the Dakotas. This high pressure will bring clearing skies and decreasing winds Friday evening, which could allow for a quick temperature drop through the 40s, with some areas falling into the 30s already by mid to late evening. Will be a much more fall-like feel to outdoor activities Friday evening, so attendees should plan to dress accordingly!

This leads into what should be the coldest night of the autumn season so far, and models have been trending colder with Friday night low temperatures. Beginning to look more favorable for widespread frost development across much of the forecast area and likely will see Frost Advisories hoisted at some point in the next 24-36 hours. Uncertainty comes in whether some parts of the area will need a Freeze warning for temperatures 32F or below. While probability of temperatures below 32F have been increasing over the past several forecast cycles, especially for portions of southwest Minnesota/northwest Iowa, extent is still uncertain. The high pressure is quick to move east and even northwest Iowa should see an uptick in south winds by late tonight which could support a slight rebound in temperatures prior to sunrise Saturday. All that to say, anyone who still has sensitive vegetation outdoors will want to take action to harvest or protect the plants as needed.

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 /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 640 AM CDT Thu Oct 15 2026

MVFR-IFR ceilings and VFR-MVFR visibility in rain/patchy fog will dominate the morning, with VFR conditions becoming more prevalent from northwest to southeast through the afternoon-early evening as rain comes to an end. However, MVFR ceilings are expected to pivot back into the area from the north later evening through daybreak Friday, with additional light showers possible north through east of Sioux Falls.

As ceilings improve, northwest winds are expected to quickly increase, with frequent gusts 30-40kt expected to spread across the region this afternoon through the end of the TAF period.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory from 3 PM this afternoon to 4 AM CDT Friday for SDZ050-057-063. Wind Advisory from 3 PM this afternoon to midnight CDT tonight for SDZ052-058-064. MN...None. IA...None. NE...None.