textproduct: Sioux Falls

KEY MESSAGES

- Lingering pockets of drizzle to light showers continue to wane this evening for most areas. Additional light accumulations are expected in remaining light showers.

- Spotty showers could linger across southcentral SD and portion of the Missouri River Valley through Monday morning. Additional shower and thunderstorm chances (50%-80%) will return by Tuesday with the potential for a few stronger storms. However, uncertainty remains regarding severe storm potential.

- Below normal temperatures will continue through midweek before more seasonable temperatures return from late week into the weekend.

UPDATE

Issued at 904 PM CDT Sun Jun 21 2026

Drizzle to some isolated showers persist across parts of southeast South Dakota this evening. Expect to see these light showers to continue to diminish across the area as forcing for ascent weakens. Perhaps some very light showers may persist across parts of south central South Dakota as suggested by the latest hi-res guidance. Should this happen additional rainfall amounts would remain light at a quarter of an inch or less. Low temperatures look to fall to the 50s overnight.

Monday will be a mostly dry day as surface high pressure slides through the area. That said, some of the hi-res models suggest that a CU field will develop as diurnal mixing deepens tomorrow afternoon. This CU field looks to have just enough moisture to squeak out a spotty light shower. With drier low level air in place, virga is also possible as well. High temperatures look to warm to the 70s while winds stay light, making for a generally pleasant late June day despite the spotty light showers. Things begin to change heading into Monday night as a shortwave trough looks to push into the Northern Plains. While strong to severe storms look to develop across the Black Hills and progress eastwards through the night. These storms look to race out ahead of the elevated instability in place, allowing these storms to weaken to well below severe thresholds by the time they cross east of the Missouri River.

These weak storms will push through the area during the morning hours on Tuesday. At the same time, a cold front will be pushing into the area from the west. This front could result in another round of strong to severe storms. That said, there is uncertainty regarding this severe storm potential due to the morning storms potentially disrupting the environment. The best forcing for ascent looks to push north of the area as well. These factors make for an uncertain severe storm forecast for the day on Tuesday. Continue to monitor the latest forecast for the most up to date information.

DISCUSSION

Issued at 208 PM CDT Sun Jun 21 2026

CURRENTS & TONIGHT: A dreary day continues! Taking a look across the area, we're continuing to watch areas high-based showers and drizzle progress through portions of the area this afternoon. While we're still on track for this intermittent activity to continue through early evening, we're starting to see an influx of drier air via water vapor satellite imagery lift into the area which could gradually erode at this activity over the next few hours. If this continues to hold true, things could taper down rather quickly with most activity becoming focused across southcentral SD into the evening. From here, we'll probably continue to have spotty showers across portions of southcentral SD and the Missouri River Valley through Monday morning as the surface low stalls out across northcentral NE and gradually weakens. Otherwise, another cool night will be on tap as lows decrease into the low to mid 50s.

MONDAY & TUESDAY: Looking into the early week, could still have a few spotty showers to start the day on Monday mainly across southcentral SD. While accumulations will be light, could see coverage expand in the early afternoon as a weak wave moves through the area and a couple hundred Jules of instability develop above the mixed layer. Nonetheless, should see this spotty activity gradually diminish after sunset as we lose diurnal heating. By Tuesday, additional shower and thunderstorm chances (50%-80%) are expected as a cold front progresses through the area. However, the severe weather risk looks more uncertain than yesterday. Still a wide range of solutions as far as how things could evolute during the day. With this in mind, this is probably the reason why our friends at SPC just blanketed most of our area in a Day 3 Marginal (Level 1 of 5). Nonetheless, another high shear/low CAPE environment will make for at least a marginal risk for large hail and damaging winds along and ahead of the surface front. Won't know many additional details up until guidance latches on a solution though. Lastly, temperatures will continue to hover near to just below normal with highs mainly in the low to mid 70s on both Monday and Tuesday.

WEDNESDAY ONWARDS: Heading into the midweek, quieter conditions should return for Wednesday and Thursday as a surface high tracks through our area. From here, the wave train returns by Friday as quasi-zonal flow helps usher in multiple shortwaves increasing the chances from showers and potentially thunderstorms almost daily (every 24-36 hours) into the following week. While the chances for severe weather are still uncertain at this time, this is another period that will need to be monitored closely moving forward. Lastly, we'll start to see temperatures build towards more seasonal conditions with highs increasing from the low to mid 70s on Wednesday to the low to mid 80s by Saturday.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 629 PM CDT Sun Jun 21 2026

VFR conditions are expected for the majority of the period. Light rain is beginning to dissipate across the region. This will continue over the next few hours before ending around midnight for the TAF sites. An few lingering showers over south central South Dakota may hang on into early Monday morning. The remainder of the period should be dry.

Winds will become light and variable overnight. As temperatures fall to or near the dew points patchy fog may develop. Visibility may fall to less than 3 miles at times. Fog is expected to burn off shortly after sunrise. By late morning winds will become southerly but remain light.

FSD WATCHES/WARNINGS/ADVISORIES

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