Area Forecast Discussion

KEY MESSAGES

- Strong winds will be out of the south to southeast, with gusts of 30 to 50 mph over central South Dakota this afternoon and west of Interstate 29 Sunday afternoon. Highest gusts will be over portions of north central South Dakota, with locally higher gusts possible.

- Thunderstorms return to the area Sunday evening through Sunday night. There is a Slight Risk, level 2/5, for severe weather along and west of a line from Eureka to Pierre. There is a Marginal Risk, level 1/5, along and east of a line from Long Lake to Murdo. Main threats include large hail (1"+ in diameter) and 60 mph wind gusts. Heavy rain that could lead to flooding is also be a concern.

- Highs will range in the upper 80s to the mid 90s this weekend, warmest over central South Dakota. This is about 10 to 15 degrees above average for early June.

UPDATE

Issued at 640 AM CDT Sat Jun 6 2026

The aviation discussion has been updated for the 12Z TAFS.

DISCUSSION

Issued at 144 AM CDT Sat Jun 6 2026

Dry conditions expected through much of the weekend before chances of precipitation move back in Sunday evening through Monday. Strong winds are also expected along with above average temperatures. A weak ridge aloft is centered over the Northern Plains into southern Canada with zonal to slight northwest flow aloft under it. The ridge will continue to amplify over the region before it starts to drift eastward on Sunday as our next longwave trough moves in off the Pacific and sets up over the western CONUS. Under this ridge, 850mb winds will be out of the south to southeast with temps ranging from 18-24C this afternoon and again Sunday afternoon (94-99 percentile). Add in daytime mixing with return flow at the surface and highs will be in the mid 80s to the lower 90s this afternoon and upper 80s to the mid/upper 90s on Sunday with temps about 2-5 degrees warmer for any one location on Sunday. This is about 10-15 degrees above average for this time of year. Dewpoints will range in the upper 50s to the lower 60s today and lower to mid 60s Sunday, so this will add a muggy feel to the air as well. Heat indices will stay below 100 (REFS probability less then 10%) so no Heat Headlines are expected at this time. Heat Risk indicates Minor to Moderate Category this weekend with Moderate Category meaning "affects those who are sensitive to heat, especially those without cooling/hydration."

With high pressure over the eastern Dakotas into MN and low pressure over MT, the pressure gradient will steepen this afternoon and evening (~10mb difference across the CWA) with the steepest gradients over central SD. NAM soundings show steep low level lapse rates to about 700mb with the top of the mixing layer around 30kts over central SD. So gusts at the surface are forecast between 30-50 mph, with the highest gusts over Corson/Dewey Counties. As everything shifts a bit east for Sunday, gusts of 30 to 45+ mph are forecast again with these windy conditions extending more eastward, mainly west of I29, with the highest gusts again north central SD. NBM Probability of wind gusts>45 mph is up to 85% over Corson and northern Dewey this afternoon and 55-65% over this area along with the higher elevations of the Leola Hills Sunday afternoon. NBM Max Gusts show the potential of 40-55 mph over central SD this afternoon and west of I29 Sunday afternoon, again highest gusts over north central/Leola Hills. With collab from surrounding offices went ahead and issued a Wind Advisory for Corson/Dewey Counties from 18Z this afternoon through 05Z Sunday.

By Sunday evening, this low (and shortwave) that was over MT will extend over the western Dakotas (center of low over northern ND) with a warm front extending southeastward through north central through southeastern SD and a cold front extending southward over the western Dakotas as a surface trough lies vertically ahead of the cold front. At the same time, a shortwave will be tracking northeastward and over southeastern SD/NE/IA border by the evening. Both of these systems will be the focus of showers and thunderstorms. Storms will be moving in/developing mainly along and west of the Mo River Sunday late afternoon/evening through Sunday night with the cold front tracking east and along the James River by 12Z Monday. Shower and thunderstorms are also possible over east central SD with the shortwave. Showers and thunderstorms chances will continue along and ahead of the front (James Valley and eastward) before the front exits our far eastern CWA by ~late Monday afternoon/evening with cooler air moving in behind the front. NAMNest is the only CAM to go out this far but does indicate broken lines/clusters of storms moving in over central SD with most of this convection west of the James River by 06Z Monday. We will have to wait for more of the HiRes models to come in today. For Sunday evening/night, REFS indicates CAPE between 1000-1500 j/kg, mid level lapse rates of 7-8C/km, and bulk shear of 30-40kts (highest over north central SD) and increasing behind the cold front as it track east with ongoing moist low levels and warm temps. So with this, the SPC has a Slight Risk, level 2/5, for severe weather along and west of a line from Eureka to Pierre. There is a Marginal Risk, level 1/5, along and east of a line from Long Lake to Murdo. Main threats include large hail (1"+ in diameter) and 60 mph wind gusts. Heavy rain that could lead to flooding is also be a concern.

Another low will sweep across the Northern Plains, and shortwave aloft, Tuesday through Thursday bringing the return of shower and thunderstorms and the risk of severe weather both Tuesday and Wednesday afternoon into the night. As of now the SPC has highlighted a 15% chance of severe weather over portions of north central SD Tuesday and mainly east of the James River on Wednesday. As this is several days out, more details and specifics will be nailed down in the upcoming days. With a break in the heat on Monday, temps will rise back up into the 90s Tuesday/Wednesday with a probability of 100 degrees is 35-55% over south central SD Tuesday afternoon and 30-40% over southern Lyman/Buffalo Counties Wednesday afternoon. Heat Risk category is Moderate over most of the CWA Tuesday with Major over portions of east central SD Tuesday and Wednesday meaning "affects anyone without cooling/hydration". Behind the cold front much cooler air moves in with temps in the 70s and 80s for the end of the week.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1219 PM CDT Sat Jun 6 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected through Sunday morning with breezy southeast winds remaining elevated through tonight and into Sunday.

ABR WATCHES / WARNINGS / ADVISORIES

SD...Wind Advisory until 11 PM MDT this evening for SDZ003-015. MN...None.