textproduct: Sioux Falls

KEY MESSAGES

- Lingering showers will continue through 8am before dissipating. Severe weather risks continue to shift towards central Iowa.

- Strong northwest winds are expected today with gusts of 45 to 55 mph. A Wind Advisory will be in effect for the entire area from 10 am to 9 pm on Wednesday.

- Isolated to scattered showers Wednesday afternoon could result slightly higher wind gusts (to 60 mph) during the afternoon.

- Strong to severe storms could return on Saturday. Specific details are uncertain, but as of now, the highest probabilities for severe storms remains south and west of the area.

UPDATE

Issued at 305 AM CDT Wed Jun 17 2026

No major changes made to the forecast over the upcoming 12-24 hours. Low-lvl flow continues to increase this morning, with VWP showing 50+ knot winds at FSD/OAX this morning. Instability has been a bit slower to arrive than suggested by the RAP as strong moisture transport has lagged. Soundings from the HRRR/GFS/NAM all showing some minor inhibition lingering over NW Iowa from any parcel lifted at 800 mb where the greatest concentration of low- lvl convergence exists. However, if we can erode this inhibition, then a few stronger storms remain possible through 7am over NW Iowa and southern Minnesota before the wave pushes through the CWA. Large hail remains the greatest risk, but some wind may also be possible. The threat will move east of the CWA by 7am with the passage of the wave and veering of the LLJ.

Strong northwest wind remain on target to arrive into South Central SODAK by 8am and will spread eastward through the day. Soundings show potential for scattered 50+ mph wind gusts, so advisory remains valid. Given dry conditions through the Missouri and James river valley, locally elevated fire danger will be possible this afternoon. It may not take long into the day for scattered showers and thunderstorms to develop over northern South Dakota and track southeast during the day given increasing low-lvl lapse rates.

DISCUSSION

Issued at 226 PM CDT Tue Jun 16 2026

Starting to see some echoes on radar begin to move into the forecast area from central South Dakota this afternoon as we begin to see an upper level wave push into the Northern Plains. With dry air in the low levels, little if any rain will reach the surface. Could see an isolated wind gust up to 30-40 mph as the showers push through. The main forcing from the wave will come during the overnight hours which will increase the coverage of showers and some storms. Latest hi-res guidance shows a strengthening low level jet (LLJ) that will bring a small elevated moist layer northwards. This moist layer will push into locations around highway-60 eastwards. This will be a brief window where weak elevated instability on the order of about 300 to 500 J/kg of CAPE can be generated and support the potential for an isolated severe storm. The timeframe is between 4 am to 7 am. Large hail up to quarter size is possible. These showers will continue to push off to the southeast and begin exiting the area through tomorrow morning.

A cold front will push through the area early Wednesday morning. A strong push of cold air advection (CAA) will accompany the cold front. Despite the CAA, highs look to warm to the 70s and 80s. The main impact from the CAA will be strong northwest winds. Winds will gust up to 45-55 mph Wednesday afternoon across the entire area. As such, a Wind Advisory has been issued for the entire forecast area from 10 am to 9 pm. Another round of isolated to scattered showers is on the table as well for Wednesday afternoon. Isolated higher wind gusts are possible within these showers. Elevated fire danger is possible across south central South Dakota where the humidity will be lowest. The shower activity will be waning through the evening along with the strong wind gusts.

Thursday and Friday will be relatively quieter days with high pressure pushing through the area. High temperatures will warm to the 70s and 80s. A few showers are possible on both days but otherwise the days should largely be dry. Low temperatures will fall to the upper 40s, 50s, and low 60s. The warmest lows will come Friday night.

Upper level troughing will be pushing eastwards on Saturday, putting the right entrance region over the forecast area. This looks to bring a warm front near the Missouri River valley. Medium range guidance has the surface warm front south and west of the forecast area. The ensembles also support this as they also show the surface front residing south and west of the forecast area. The vast majority of machine learning guidance (ML) further supports this conclusion as well. That said, this is the surface front location. Can't rule out the potential for elevated storms though it is too far out to say for sure if the elevated boundary may make it to near the Missouri River Valley. The ensembles also show the highest probabilities (60-80%) for rainfall amounts exceeding a tenth of an inch south and west of the Missouri River as well. Aside from storm chances, Saturday looks to be a near seasonable day with highs in the upper 70s and 80s.

Zonal flow looks to take over for Sunday and Monday. This could result in additional chances for rain but this remains uncertain due to the variance in shortwave troughs evolution among the medium range guidance. The ensembles reflect this uncertainty as they only show a 20-40% chance for rainfall amounts to exceed a tenth of an inch on both days. Otherwise temperatures look to remain near seasonable in the 70s.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 549 AM CDT Wed Jun 17 2026

Scattered showers and few thunderstorms continue to move southeast at daybreak. Ceilings remain VFR, with stratus along highway 20 expected to move away this morning.

A surface front will push though the area this morning, turning winds to the west and northwest, with potential gusts to 50 mph through the afternoon.

Isolated to scattered showers and thunderstorms form quickly by mid-day and drift southeast through the afternoon. This activity could bring brief pockets of MVFR visibility and slightly stronger winds as they pass through. With the loss of heating, this activity should dissipate early this evening.

VFR conditions expected into Thursday morning.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory from 1 PM this afternoon to 9 PM CDT this evening for SDZ040-056-062-067-071. Wind Advisory from 10 AM this morning to 9 PM CDT this evening for SDZ038-039-050-052>055-057>061-063>066-068>070. MN...Wind Advisory from 1 PM this afternoon to 9 PM CDT this evening for MNZ071-072-080-081-089-090-097-098. IA...Wind Advisory from 1 PM this afternoon to 9 PM CDT this evening for IAZ001>003-012>014-020>022-031-032. NE...Wind Advisory from 1 PM this afternoon to 9 PM CDT this evening for NEZ014. Wind Advisory from 10 AM this morning to 9 PM CDT this evening for NEZ013.