textproduct: Aberdeen

KEY MESSAGES

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

- There is an Enhanced Risk, level 3/5, for scattered to numerous severe storms over the western half of Corson County. There is a Slight Risk, level 2/5, for scattered severe storms along and west of the line from Eureka to Murdo. Main threats include large hail, one to two inches in diameter, and wind gusts of 70+ mph. A tornado or two cannot be ruled out or hail over 2 inches in diameter within the Enhanced Risk. Heavy rain that could lead to flooding is also be a concern.

- Highs will range in the upper 80s to the mid 90s again today, warmest over central South Dakota. Brief cooldown for Monday before high temperatures back in the 90s on Tuesday with the potential of a few 100 degree readings.

UPDATE

Issued at 630 AM CDT Sun Jun 7 2026

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

DISCUSSION

Issued at 142 AM CDT Sun Jun 7 2026

Winds will continue to be strong today, similar to yesterday. As of 06Z, a high is to our east (over southern Ontario) and low just to our west (along eastern MT/WY and western Dakotas). We continue with a tightened pressure gradient (~10-12mb across the state) with winds currently between 10-20 mph sustained. By midday into the afternoon Rap soundings indicate dry and steep low level lapse rates to about 750mb with the top of the mixed layer around 20-30kts at KABR/KATY to 30-35kts over KMBG/KPIR. With daytime mixing, winds will increase out of the south to southwest with gusts of 30 to potentially 50 mph. These gustier winds will extend a bit more eastward then yesterday, mainly west of I29, with the highest gusts of 45-50mph over north central SD. NBM Probability of wind gusts>45 mph is 45- 65% over Corson/Dewey and Leola Hills with NBM max gust potential of 50-55mph for this area. A Wind Advisory has been issued for counties in north central SD from 17-01Z.

Return flow at 850mb with speeds between 20-30kts and temps will once again range from ~18 to 25C at peak heating, which runs in the 94-99th percentile range at this height. Mixing with warm southeasterly winds at the surface and highs will be similar to yesterday ranging in the upper 80s to the mid 90s. Add in dewpoints ranging in the 60s and it will feel quite sticky out there!

Our attention then turns this evening through late tonight. By 00Z, the center of the deepening low is forecast to be over ~northwestern ND/Canada with its cold front extending south and southwest through western ND and SD. Aloft a strong shortwave will be over the Northern Rockies within an overall long wave trough with a belt of 45-70kt winds along the southern and eastern side of the low mainly over MT/ND, brushing northwestern SD. With this ongoing low level moisture and synoptic setup, this sets the stage for showers and thunderstorms to fire up once the cap breaks ahead of the front. CAMs show this occurring over the western Dakotas/MT/WY late this afternoon/evening as discrete cells turning more into a linear fashion as it enters north central SD (Mainly Corson/Dewey who get the brunt of it) through ND by ~00-02Z. Little bit uncertain on exact storm mode at this time whether its more discrete, embedded discrete cells turning linear, or all linear. Also low confidence on the southern extent of this potential line as a few of the CAMS show more of an extent into south central SD. This line (or lines) will all track east/northeast through early Monday morning. Looking at parameters, CAPE will range from 1000-2000j/kg with HREF max up to 3000j/kg this evening with values rapidly diminishing with sunset. Bulk shear of 30k-40kts will be over far western Corson County this evening with these values shifting a bit eastward over north central SD through 06Z and to the James River by 12Z. Ongoing steep low level lapse rates with mid level lapse rates between 7-8C/km over central SD supports the threat of large hail if cells are still discrete or embedded within the line at this time.

Only change to the Enhanced Risk is that Dewey County is out of it and now in the slight therefore, there is an Enhanced Risk (level 3/5) for the potential of scattered to numerous severe storms over the western half of Corson County as max 2-5km UH>75m2s2 per HREF indicates organized convection tracking southwest to northeast over western SD/ND and possibly clipping western Corson with the threat of supercells staying mainly to our north and west, however, if cells are still discrete it is not out of the question for a couple to clip Corson. Main threat will be large hail of 1-2" in diameter mainly between 02-05Z with SPC highlighting the tornado threat north and west of us. Again if we can get a couple supercells over this enhanced area, then a tornado or two could be possible as there is a bit of low level SRH but 0-1km shear is very weak as RAP hodographs are curved but small. Any supercell could also have the potential of over 2" hail with these stronger lapse rates. Otherwise if its linear coming into the CWA, wind gusts of 60-75+mph is possible too as DCAPE will be above 1000j/kg. There is a Slight Risk (Level 2/5) along and west of the line from Eureka to just west of Murdo (to the enhanced risk). Main threat for this area will be 1-2" diameter hail (any embedded discrete cells) and wind gusts of 60-70+ mph as storm mode should be linear by this time meaning more of a wind threat then anything. Especially with the help with a LLJ of 30-40kts ahead of the cold front, this could develop into more of an MCS as it tracks across the Dakotas. Lastly, there is a Marginal Risk (level 1/5) along and east of a line from Long Lake to Murdo to just west of I29. As these storms track east of the slight risk, it will lose steam and the better instability as CAMs show it breaking apart and more of a messy line or blob of storms. However, hail up to quarter and 60 mph winds cannot be ruled out. With PWAT being at or above an inch, heavy rain is a threat with these storms that could lead to flooding, especially for areas that have recieved an abundance of rain last week.

By 12Z Monday, the fropa is forecast to be along the James River with any ongoing convection occurring ahead and along the front before the fropa exits the eastern CWA by late Monday evening. There is a Marginal Risk (level 1/5) for ongoing severe storms mainly for the James Valley. This unsettled weather pattern continues as another low (and its shortwave) will track across the Northern Plains Tuesday and Wednesday bringing the return of showers and thunderstorms and the threat of severe weather. The SPC has a 15% risk for the entire CWA Tuesday and James Valley and eastward Wednesday.

Cooler air moves in behind the front Monday into Monday night but that will be short lived as highs will jump right back into 90s to as high as 102 over portions of south central SD. Add in dewpoints in the upper 60s to the lower 70s and heat index could top out at or over 100 degrees for some locations along the James River and south central SD. A Heat Headline may possibly be needed closer to time. Fast forward to the end of next week and weekend as the region will be influenced by an upper level trough with winds west to northwest. Highs are forecast to only range in the 70s to low 80s.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 630 AM CDT Sun Jun 7 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will persist at all terminals through most of today into this evening. Southeast winds will become gusty peaking between 25-35 kts from mid to late morning through this evening. A cold front will sweep west to east across the area late tonight through Monday morning. Scattered thunderstorms are expected to accompany this frontal passage. Some storms could be strong to severe. MVFR cigs/vsbys will be possible at KABR/KMBG terminals in the strongest showers and storms. KATY/KPIR were left dry for now as chances for seeing any precipitation is low.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory from noon CDT /11 AM MDT/ today to 8 PM CDT /7 PM MDT/ this evening for SDZ003>005-009-010-015. MN...None.