textproduct: Sioux Falls

KEY MESSAGES

- Scattered light rain showers move through the region into the overnight hours. Brief 30 to 40 mph winds and graupel will be possible this evening.

- Scattered areas of frost will develop starting tonight and potentially Saturday morning. As a result, a frost advisory will now be in effect for most areas from 1 am to 8 am CDT.

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

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 /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 555 PM CDT Thu Apr 30 2026

Scattered VFR showers will continue to move southeast this evening. Generally minimal impact to aviation interest can be expected, though isolated reports of 30 to 40 mph winds may be possible, along with graupel.

This activity will diminish late this evening leaving VFR skies and light winds through the Tri-State area into Friday morning.

Cool conditions aloft on Friday and reasonable afternoon surface heating will again produce scattered CU in the region as winds turn gusty from the NW in the afternoon.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Frost Advisory from 1 AM to 8 AM CDT Friday for SDZ038>040-050- 052>071. MN...Frost Advisory from 1 AM to 8 AM CDT Friday for MNZ071-072-080- 081-089-090-097-098. IA...Frost Advisory from 1 AM to 8 AM CDT Friday for IAZ001>003- 012>014-020>022-031-032. NE...Frost Advisory from 1 AM to 8 AM CDT Friday for NEZ013-014.