textproduct: Sioux Falls

KEY MESSAGES

- Showers are moving off to the northeast this afternoon. Lingering light showers and isolated thunderstorms are possible through this evening. Brief funnels will be possible mainly over northwest Iowa through 8 pm.

- Periodic chances for rain remain in the forecast for much of the upcoming week. However, details are uncertain at this time.

- Below normal temperatures will continue through Saturday before warmer conditions return from Sunday onwards.

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 /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 639 PM CDT Fri May 22 2026

A few showers and storms will continue primarily east of I-29 early this evening before exiting off to our north and east. As these showers push out of the area, it will take the MVFR/IFR ceilings along with it, leaving mainly VFR conditions through the period. The exception will be an area of clouds wrapping around a low pressure system as moves across the area mainly north of I-90, where brief MVFR ceilings will be possible through tonight. These lower clouds could briefly impact KHON and KFSD towards the middle of the night, but are more likely to stay north and east of those sites.

Patchy fog can't be ruled out tonight due to all the moisture left behind from today's rain and as winds turn lighter. Confidence was not high in the overall coverage and longevity of this fog to include in the TAFs, but perhaps the best chance of this occurring would be at KSUX (around 25-35% chance). Winds will turn more easterly through tonight, but stay on the lighter side through the period.

FSD WATCHES/WARNINGS/ADVISORIES

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