textproduct: Sioux Falls

KEY MESSAGES

- Pockets of fog will be possible through 9 am, especially in areas that saw rain yesterday. Locally dense patches could lead to visibility as low as 1 mile or less at times.

- Near to above normal temperatures will continue into the new week with highs mainly in the 80s to mid 90s. Heat indices may approach the upper 90s in spots Monday and Tuesday afternoon.

- A break from severe weather is expected today and Monday, but a few strong to severe storms appear possible again late Tuesday into Tuesday night. Keep up to date with the latest forecast!

UPDATE

Issued at 430 AM CDT Sun Jul 5 2026

Patchy fog, some locally dense, remains possible through about 9 this morning before lifting and leading to a mostly sunny day across the area. Plenty of instability with little CIN is expected by late this afternoon, but no appreciable lift to really get storms going. That is unless there is a lingering outflow boundary around from last night's storms that a new storm can develop on. Chances for this are very low, less than 15%, but will at least be something to watch out for. Otherwise a warm day with light winds is in store for our Sunday with highs ranging from the lower 80s east to around 90 west.

Things get a bit warmer and more humid heading into Monday and Tuesday, when heat indices may reach the middle to upper 90s each afternoon. At this point, it looks like we should remain below heat advisory criteria, but remember to still stay hydrated and take some breaks if playing or working outside. This will also set the stage for additional shower and storm chances as a series of ridge-rider upper waves move across the region. The better chances for this activity becoming severe over our area will be late Tuesday into Tuesday night, where the Storm Prediction Center highlights a Level 2 out of 5 Slight Risk mainly near and north of a Yankton, SD to Sheldon, IA, to Jackson, MN line. This is because a front looks to move into central South Dakota along with an increasing low level jet of 40-45+ kts as shown by the GFS/NAM noses into our area out ahead of it. This is of course still a few days out, so keep up to date with the latest forecast as details and threats become more clear.

DISCUSSION

Issued at 238 PM CDT Sat Jul 4 2026

CURRENTS & TONIGHT: Taking a look across the area, the focus continues to be across portions of northwestern IA as a lifting outflow boundary continues to spur pockets of convection across portions of northwestern IA. While this developing activity continues to stay mostly sub-severe, the enhanced stretching potential and weak flow aloft has led to multiple funnels being reported mainly near Greenville and Sioux Rapids, IA in Clay County. With this developing activity potentially continuing over the next few hours have decided to issue a special weather statement (SPS) for most of northwestern IA, portions of southwestern MN, and portions of southeastern SD through 5 PM.

Otherwise, we're still on track for a few additional isolated to scattered thunderstorms with an approaching wave this evening. Given the modest CAPE and low shear set up, there is still a decent shot for a few stronger storms with up to half dollar sized hail and damaging winds up to 60 mph being the main threats. While there is still some uncertainty as to how things will evolve, most short- range guidance has now settled in on areas east of I-29 and along the Missouri River Valley as the two areas for potential development through the late evening so make sure to have multiple ways to receive warning information! Lastly, can't rule out some additional chances for patchy fog tonight with the higher dew points. Similar to this morning, locally dense patches could lead to visibilities of 1 mile or less at times through mid-morning before dissipating.

SUNDAY-TUESDAY: Looking into Sunday, quieter conditions will temporarily return as ridging begins to build across the Desert Southwest. With weaker flow aloft and increasing warm air advection (WAA), should continue to see temperatures trend above normal through Tuesday with highs mainly in the 80s to 90s each day. Looking aloft, our next precipitation chances could arrive as early as Monday night into Tuesday as an approaching shortwave intersects a stalled surface boundary roughly draped from the Black Hills to northeastern SD. While there is still some uncertainty as to how far east this boundary sets up, there should be just enough lift with the wave to trigger a few scattered showers and thunderstorms during the afternoon to evening hours with the potential for a few stronger storms. Given another modest CAPE/low shear environment, any developing activity will be quite pulsy. However, current thoughts are an isolated severe risk will be possible mainly along and south U.S. Highway-14 heading into the afternoon and evening hours. Otherwise, additional chances for showers and thunderstorms will return from Tuesday into into Wednesday as another shortwave and an a cold front progress through the area. However, some uncertainty remain so make sure to monitor your local forecast as the details are subject to change.

WEDNESDAY-FRIDAY: Heading into the extended period, the previously mentioned ridging begins to flatten giving way to quasi-zonal flow by Wednesday. With the wave train expected to resume aloft, we could see near daily chances for precipitation through Friday. While the severity of these storms is still uncertain, confidence is not high enough to deviate from the NBM at this time. Otherwise, we'll continue to see near to above normal temperatures through Friday with highs mainly in the 80s to low 90s.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 627 AM CDT Sun Jul 5 2026

Patchy MVFR-locally IFR visibility in fog around the area early this morning, but is not expected to impact TAF locations. Aside from this patchy fog, VFR conditions will prevail through the period with light winds, generally east to southeast.

There is a very low chance of a few sprinkles/stray thunderstorm south of I-90 this afternoon, but potential is far too low to include a mention at KSUX at this time.

FSD WATCHES/WARNINGS/ADVISORIES

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