textproduct: Aberdeen

KEY MESSAGES

- Isolated showers and storms will be possible this afternoon into early evening. This activity will remain sub-severe with only small hail and locally heavy downpours the main threats.

- High temperatures through the end of the week will remain in the upper 80s to mid 90s(15 to 20 degrees above normal). Slightly cooler air will filter in this weekend into early next week but still remain above normal.

- Increasing chances(30-70 percent) for showers and thunderstorms will be possible this weekend into early next week.

DISCUSSION

Issued at 250 PM CDT Wed May 27 2026

Early afternoon conditions across the forecast feature a mostly sunny sky across central SD while northeast SD and west central MN are seeing more mid to high level clouds. A relative light to moderate wind has been the going trend today as temperatures have warmed into the mid 80s to low 90s. Upper level ridging is positioned right over the top of the area and has "trapped" this mid level moisture as it continues to wobble around underneath and remains the impetus for future enhancement as instability builds through the afternoon. CAM's continue to hint that more development of isolated showers and thunderstorms this afternoon across northeast SD/west central MN. MLCAPE values of 1000-1200 J/kg are forecast from the RAP13 through late afternoon along with the presence of a stationary frontal boundary draped northwest to southeast across our eastern zones should be enough to focus any convection across these areas. Deep layer shear is rather meager if non-existent, so anything that does get going should be short-lived. Most of the activity will be sub-severe with any of the strongest cells capable of producing small hail and locally heavy downpours.

The upper ridge will remain planted over the eastern Dakotas and western MN tonight through most of Thursday. CAM's hint that the isolated convection may persist into the early to mid evening hours before coming to an end. Dry conditions overall are expected overnight as temperatures only fall to around 60 degrees, which is about 10 degrees above normal. That stationary front will lift north and east toward the Dakotas/MN border area by the end of the day Thursday. Another hot day is expected Thursday as 850mb temps are progged top out around +20C across most of the forecast area. This will give us another day of low to mid 90s for highs which is 15-20 degrees above normal for late May. There are a couple of CAM solutions that want to generate a couple of isolated showers or storms Thursday afternoon across parts of central/northeast SD. However, ML CAPE values are progged to be lower than today's progs and shear will remain rather non-existent plus soundings show quite a deep and dry sub-cloud layer. So for now, we'll keep the forecast dry for Thursday.

A weakness on the western fringe of the upper ridge will lift north into the Northern Plains by late Thursday into Friday. This will begin to introduce low to mid level moisture back into parts of the region by the end of the day Friday and into the upcoming weekend. Model inconsistencies remain in placement and timing of any showers and thunderstorms the latter half of Friday into Saturday, although enough guidance does tend to favor our western zones for seeing precip during this time. A more organized upper trough is progged to shift northeast out of the Great Basin and into the Northern High Plains on Saturday into Sunday. Lee troughing with perhaps a sfc low anchored on said boundary is progged to shift into the western Dakotas during the second half of the weekend. This should provide for more widespread precipitation chances for a larger portion of our forecast area by Sunday into early next week. Questions still remain on the longevity of this more active pattern. The GEFS/GEPS camps reassert upper level ridging across the region by next Tue/Wed while EC ENS maintains upper troughing across the Dakotas during that time frame. In house ensemble approach will continue to broad- brush low end PoPs late in the forecast period.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1224 PM CDT Wed May 27 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will continue to prevail at all TAF sites through this forecast period. Still expecting the development of a few SHRA's/TSRA's late this afternoon into this evening across northeast SD. Coverage of this activity is expected to remain isolated so not confident enough to add mention of this to the KABR/KATY forecasts at this time.

ABR WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None.