textproduct: Sioux Falls

KEY MESSAGES

- Scattered light rain showers continue to move through areas mainly east of I-29 into the early morning hours.

- Frost potential looks to be greatest for portions of southeast South Dakota and southwest Minnesota late tonight/early Friday and a Frost Advisory remains in effect from 1 am to 8 am CDT Friday.

- Conditions appear more favorable for widespread frost by early Saturday morning. Additional headlines will likely be needed Friday night-early Saturday.

- After above normal temperatures over the weekend, more seasonable conditions return by midweek as mostly dry conditions persist.

UPDATE

Issued at 939 PM CDT Thu Apr 30 2026

Spotty showers linger mainly east of I-29 and should continue to drift east of the area through the pre-dawn hours. With pockets of surface dew points still well above freezing trailing the light showers, some questions whether temperatures roughly along/east of IA/MN Highway 60 will cool enough to allow for impactful frost development, but opted to leave the current advisory as is.

Potential for spotty afternoon showers toward the Highway 71 corridor has decreased since this time yesterday with Friday looking like a dry but partly sunny day with decent afternoon cumulus development. Friday night to early Saturday looks more favorable for frost development across most of the forecast area with mostly clear skies and light/variable winds within a broader surface high. With current advisory in effect, do not plan to issue any headlines for this period at this time, but anticipate that one will be needed if forecast trends hold.

DISCUSSION

Issued at 154 PM CDT Thu Apr 30 2026

CURRENTS & TONIGHT: A mild day continues! Taking a look across the area, we continue to see a growing cumulus ("Cu") field develop on visible satellite imagery mainly due to about 100 J/kg or less of instability above the mixed layer. As our next wave approaches from the northwest, could see a few diurnally-driven showers develop across the area mainly north of I-90. While accumulations will be minimal, can't rule out a few pockets of moderate showers mainly across southwestern MN. Otherwise, the main concern continues to be the frost potential tonight. While there could be some lingering clouds overnight, decided that the combination of temperatures near to below freezing along with lighter surface winds tonight would be enough to get scattered areas of frost to develop especially south of I-90. With this in mind, decided to issue a Frost Advisory for most areas from 1 am to 8 am on Friday. Make sure to cover/bring in any susceptible plants!

THE WEEKEND: Looking into the weekend, could see some additional spits to very light showers across southcentral SD to start the day on Friday as another quick shortwave swings through. However, any accumulations would be minimal (if any). With lighter winds expected by Friday night with an approaching surface high, we could see our first widespread freeze with lows expected to be just near to just below freezing. With this in mind, make to cover/bring in any susceptible plants from the colder conditions. By Saturday, more northwesterly flow will set up aloft as rising heights over the western CONUS begin to flatten. Temperatures will trend warmer as increasing warm air advection (WAA) and southwesterly surface winds leads to highs in the mid 60s to low 70s. Looking aloft, another dry cold front will swing through the area from Saturday night into Sunday. Otherwise, the above normal conditions will continue into Sunday as highs approach the upper 60s to low 70s for the day. All in all, this weekend looks to be beautiful to say the least especially with the light winds in place.

NEXT WEEK: Heading into the extended period, the warmest conditions of the week will likely occur on Monday ahead of our next cold front with highs mainly in the upper 60s to upper 70s. Otherwise, more seasonable conditions will return through midweek with highs mainly in the upper 50s to mid 60s. Lastly, mostly dry conditions will continue through the end of the week.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1229 AM CDT Fri May 1 2026

Lingering showers/clouds near/east of I-29 are slow to exit, but should continue to drift east-southeast and out of our forecast area prior to daybreak. Localized MVFR ceilings accompany some of the showers, but overall VFR conditions will prevail through this TAF period.

Light and variable winds will favor a northerly direction in most areas by daybreak, with moderate gusts 15-20kt along with scattered diurnal cumulus at 5-7kft AGL range developing Friday afternoon.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Frost Advisory until 8 AM CDT this morning for SDZ038>040-050- 052>071. MN...Frost Advisory until 8 AM CDT this morning for MNZ071-072-080- 081-089-090-097-098. IA...Frost Advisory until 8 AM CDT this morning for IAZ001>003- 012>014-020>022-031-032. NE...Frost Advisory until 8 AM CDT this morning for NEZ013-014.