textproduct: Sioux Falls

KEY MESSAGES

- Scattered showers and non-severe thunderstorms will move north across the area today. A stronger storm may produce pea sized hail, but patchy lightning will be the main risk.

- Isolated strong to severe storms are possible from about 11 pm to 4 am with the better chances near the Missouri River and possibly as far north as near and west of the James River. The main threats will be small hail and wind gusts to 50 mph, but an isolated storm could produce quarter sized hail and wind gusts to 60 mph.

- The second chance for severe storms is Sunday afternoon and evening. However, confidence is low in development. If storms can develop, large hail up to ping pong balls and damaging winds to 65 mph would be the main hazards. Continue to monitor the latest forecast for the most up to date information.

- Moderate chances (30-60%) for rain will persist through the bulk of next week. However, severe storm chances continue to look low (near 5% or less) through next week. The better chances for rainfall appear to be Wednesday and Wednesday night.

DISCUSSION

Issued at 1256 PM CDT Sat May 30 2026

The latest runs of the models are more consistent on bringing a wave northward tonight with a broken line of convection. With very weak shear and CAPE values likely limited to 1000 J/kg or less, severe weather is very unlikely. An isolated storm could produce wind gusts to 60 mph or hail to the size of quarters, with the better chances near the Missouri River, possibly as far north as the James River. A few locations could pick up a little heavy rain, but for now storm motion looks quick enough that this heavy rain will likely last an hour or less at any one location. The better chances for this will be late evening into the overnight hours, generally from about 11 pm to 4 am for the stronger storms.

This wave should lift north of the area by late Sunday morning to early afternoon. Some showery activity will be possible through the morning, possibly lingering into the afternoon in southwest MN.

The next chance for showers and thunderstorms will be late Sunday afternoon into Sunday evening. This is a much lower confidence potential as the area could be muddled by cloud cover and even when the cloud cover clears, the latest models are hinting at a decent capping inversion. For now with only weak mid and upper level support, this cap may hold. There could be a slightly better wave move through Nebraska during this time which would bring a bit better chance closer to the Missouri River into parts of northwest IA. Also of note will be some low to mid level warm air advection moving across the area Sunday late afternoon into the night, starting in central SD late afternoon, which might be enough to spark some isolated activity and aid in breaking the cap. All-in-all a very low confidence set up during this time. In fact SPC just downgraded the area from a Slight Risk to Marginal.

Upper level ridging will be in place on Monday and Tuesday and limit any precipitation chances. Upper level troughing does spread into North Dakota Tuesday night through Thursday and could bring some showers and thunderstorms. The best chances should be Wednesday and Wednesday night. Faster westerly flow remains in place through the end of next week and this will likely support periodic chances for showers and storms as well.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1224 PM CDT Sat May 30 2026

An abundance of challenges ahead with scattered showers and very isolated thunderstorms moving northward through the afternoon. From late afternoon through about 10 pm much of the area will see a break from any precipitation. However from about 10 pm through 4 am a broken line of thunderstorms is expected to move northeast through the area, possibly bringing some wind gusts to 40 mph and patchy heavy rain. Late tonight into Sunday morning we should see most activity transition to mostly showers and very little thunder again. As for ceilings, patchy MVFR ceilings are expected today, then they should gradually deteriorate in most locations later tonight into Sunday morning, likely to IFR.

FSD WATCHES/WARNINGS/ADVISORIES

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