textproduct: Aberdeen

KEY MESSAGES

- A Marginal Risk (level 1 of 5) for severe weather remains posted mainly for tonight into early Sunday. Large to very large hail of 1- 2+ inches and damaging wind gusts of 60 mph will be the main threats.

- A Marginal Risk (level 1 of 5) to a Slight Risk (level 2 of 5) for severe weather has been posted for Sunday and Sunday night. Large hail up to golfball size and damaging winds of 60-70 mph will be the main threats.

- Wildfire smoke aloft is expected to persist the next several days, however there is little potential for the smoke at the surface.

DISCUSSION

Issued at 251 PM CDT Sat Aug 8 2026

Sfc high pressure remains centered across southern MN/northern IA this afternoon while an expansive area of low pressure sits over the Dakotas/MT/WY border region. Southerly flow has returned a warm and more moist air mass into our region today with afternoon dew point temperatures in the upper 50s to mid 60s. An ACCAS field continues to drift northeast across parts of central and northeast SD this afternoon but so far it remains dry underneath this feature. There were some hints that this warm advection regime setting up would touch off an isolated shower or storm this afternoon across northeast SD, particularly the Big Sioux Valley area. It remains a minor mention in the forecast but confidence it low as most CAMs are not showing anything occurring.

Conditions more favorable for convection will become more evident later tonight into early Sunday as the sfc low drifts southeast and meets up with a southward sagging frontal boundary coming out of ND into northern SD. Broad northwest flow aloft will remain persistent that could include passage of some mid level energy. A nocturnal low level jet will interact with moderate to strong CAPE and steep low- mid level lapse rates along with strong deep layer shear to kick off thunderstorm activity. CAMs seem to focus initiation ND tonight and then track the activity south and east through our CWA. This could occur as early as mid to late evening but our better window for severe weather looks to be after midnight. Given the favorable parameters, very large hail up to 2 inches will be the main threat along with damaging wind gusts of 60 mph. For now, a Marginal Risk (1 of 5) for severe weather remains posted for most of the CWA. Whatever comes of the overnight convection, guidance progs it to shift out of our area by mid morning leaving us with a mainly dry, warm and humid day with highs expected to reach the low to mid 80s.

We'll repeat the same setup again by Sunday night into Monday. Northwest flow aloft will persist as sfc winds veer east to southeast heading into Monday. Warm advection returning should help recover the atmosphere back into a favorable environment for convection by the end of the day through Sunday night. Moderate to strong instability and strong deep layer shear will help contribute to the development of convection Sunday evening into early Monday morning. A nocturnal low level jet across western/central SD will help to maintain activity through the overnight. Initial threats will be large hail perhaps up to golfball size. However, with time a damaging wind threat could become the main threat if an MCS is able to develop and track southeast across parts of the forecast area. A Marginal Risk (1 of 5) for severe weather covers most of the area with a Slight Risk (2 of 5) for severe weather has been posted for parts of central/northeast SD.

An active pattern is expected to spill over into the early portion of the new week. More convection will be possible by late Monday into early Tuesday as the set up remains mostly unchanged with a disturbance working into the western Dakotas. Some storms could be strong to severe across mainly western and central SD Monday night. Wildfire smoke will remain prevalent across the region for the next couple days. HRRR vertically integrated smoke product shows moderate to high concentrations of smoke in the upper layers of the atmosphere will persist into Monday. Some good news on this front is that it appear most of this smoke will stay aloft and not affect sfc conditions.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1241 PM CDT Sat Aug 8 2026

Terminals KABR,KATY,KPIR,KMBG

Expecting VFR conditions to prevail at all TAF sites through this forecast cycle. Low confidence in timing/placement of an isolated shower/storm around KATY this afternoon, so forecast remains dry for now. More scattered storms are expected late tonight into early Sunday for KABR/KATY. MVFR conditions could be possible with any convective activity.

ABR WATCHES/WARNINGS/ADVISORIES

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