textproduct: Sioux Falls

KEY MESSAGES

- Scattered showers with isolated thunderstorms will be possible this afternoon mainly along the Missouri River Valley. While severe weather is not expected, small hail and an occasional strong wind gust up to 45 mph will be possible.

- Additional chances for showers and thunderstorms will continue through Monday with the potential for some stronger storms by Sunday.

- After more seasonable temperatures today, conditions will continue to trend above normal into the new week with daily highs in the 80s and potentially 90s at times.

UPDATE

Issued at 258 AM CDT Sat May 23 2026

Taking a look across the area, we're continuing to monitor an area of low stratus along and south of the U.S. Highway-14 corridor this morning. While no significant impacts are expected, expect these lower clouds to continue to track eastwards into southwestern MN through daybreak this morning before exiting our area. Otherwise, a more seasonable day is ahead as west-northwest winds and increasing warm air advection aloft help temperatures rebound to the upper 60s to mid 70s for the day. Looking aloft, scattered showers with isolated thunderstorms could develop by early afternoon mainly along the Missouri River Valley as increasing dPVA interacts with an approaching shortwave. With only a couple hundred (300-500 J/kg) of instability to work with, severe weather is not expected. However, can't completely rule out some smaller hail and strong wind gust up to 45 mph. Lastly, most of this activity should exit our area by late evening with temperatures expected to fall into the mid 40s to low 50s for the night.

DISCUSSION

Issued at 238 PM CDT Fri May 22 2026

Rain is tapering off this afternoon from the southwest to the northeast. The remaining areas of precipitation along and north of I- 90 will continue to taper off and move northeast over the next few hours. An additional line of weak showers is forming along the leading edge of an occluding front just west of the James River Valley. No severe weather is expected from this line. However, the southern portion as it passes through areas south of Highway 18 may produce some thunder and gusty winds to 45 mph. As far as rainfall totals are concerned, an additional tenth or two is possible along and north of I-90.

Early Saturday morning patchy fog is possible as low temperatures approach dew points in the 40s. Fog is expected to burn off by mid- morning. Clouds will scatter out through the day becoming mostly sunny by afternoon. Winds will be light out of the west and highs are expected to climb into the upper 60s and 70s. Modest mid-level moisture advection and weak elevated instability may result in isolated to scattered light showers and thunderstorms Sunday. Sunday will be warm with highs in the upper 70s and 80s. Late Sunday night into early Monday morning better dynamic parameters may allow for a few isolated strong to severe thunderstorms for areas along and south of Highway 18. This area is currently under an SPC Day 3 Marginal outlook (level 1 of 5). Monday is expected to be even warmer with highs in the mid 80s to low 90s, with the warmest temperatures expected along and west of the James River Valley. Monday will also be on the muggy side with dewpoints in the mid 50s to low 60s. Periodic rain chances remain in the forecast for the remainder of next week. The next best chance for stronger thunderstorms looks to be Thursday, however details at this time are lacking. Highs for Tuesday will once again be in the mid 80s to low 90s. The rest of the week highs will generally be in the 80s.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1244 AM CDT Sat May 23 2026

An area of MVFR to locally IFR stratus is developing over portions of eastern South Dakota north of I-90 as moisture wraps around a departing low pressure system. This may bring at least temporary drops to MVFR CIGS at KHON for an hour or so towards the start of the period. This stratus likely stays north of KFSD, with low (10-20%) chance of brief impacts there early this morning. Can't rule out some patchy fog as well this morning outside of this stratus, but widespread issues are not expected. The aforementioned stratus will erode and push northeast out of the area by mid morning today, leaving VFR conditions in place through the remainder of the TAF period. A few isolated showers and maybe a thunderstorm are possible along the Missouri River Valley west of I-29 late this afternoon/early evening, but chances of TS impacts at KSUX is quite low (<15%) at this time.

Winds will tend to be on the lighter side of things through the period, mainly westerly this morning and then northwesterly this afternoon before turning light and variable this evening. Strongest winds this afternoon will generally be located over the higher elevations of the Coteau des Prairies, where gusts up to 20 kts are possible. Otherwise, an isolated gust to 30 kts will be possible if a shower or storm can develop south of I-90.

FSD WATCHES/WARNINGS/ADVISORIES

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