textproduct: Aberdeen

KEY MESSAGES

- There is a Slight Risk (level 2 of 5) for isolated to scattered storms for the Missouri valley in the late afternoon and evening, and then for the northeast during the overnight hours. Main threats include 1 to 2 inch diameter hail and wind gusts of 60 to 70 mph.

UPDATE

Issued at 724 AM CDT Tue Aug 11 2026

Webcams and satellites have shown some areas of locally dense fog affecting portions of central and northeastern SD this morning. An SPS was issued to warn of this fog as visibilities could cause visibilities to drop to 1/4 mile at times. The fog is expected to start dissipating in a few hours.

UPDATE Issued at 613 AM CDT Tue Aug 11 2026

See below for an aviation forecast discussion for the 12Z TAFs.

DISCUSSION

Issued at 1245 AM CDT Tue Aug 11 2026

Storms haven't really panned out very well considering the consensus among CAMS for the last 24 hours. Warn on forecast still indicates some development along and southeast of highway 14 over the next hour or two so we could still be dealing with warnable storms through the early morning hours. Again, large hail and high winds as outlined in the previous discussions/updates are the chief concern.

And we'll try to do it all again later today. Flow remains northwesterly aloft, with a subtle trough going across the Dakotas 03-09Z. Not much different, with strong unidirectional shear overall, but weak mid level warm advection and light low level flow at/off the surface. 1/2km winds are only about 15-20kts out of the southeast. CAMS are much less organized and more inconsistent in placement of individual convection. Thus, much lower confidence in regards to POPs (ie timing & coverage).

Still looks to be a nice shift into cooler temperatures for the latter half of the work week though overall the upper level flow regime remains northwesterly. A ridge builds in from the west Friday as an upper high shifts from 4-corners centric to southeast CONUS, which may then retrograde back to the west next week. Overall, flow remains active and its hard to support the elimination of NBM spammed POPs for any one specific period.

In regards to smoke, not much overall change. Flow aloft will continue to support high smoke streaming across the region and helping to suppress temperatures slightly. Low level flow around the cooler high pressure system mid-week may present a risk but smoke would have to take a circuitous route as boreal/northern Canada doesn't appear to be a source region anymore.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 613 AM CDT Tue Aug 11 2026

Terminals KABR,KATY,KPIR,KMBG

After some sub-VFR low clouds and fog over the region burn off this morning, VFR conditions are forecast for the rest of the TAF valid period. Guidance for convection suggests much of the next 12 hours should be quiet/dry. But, later this evening into the early overnight hours, there could be a handful of strong to severe storms around, especially out across and west of the Missouri River valley region (KPIR and KMBG?). Kept the PROB30s going for later this evening, and will amend/adjust as needed.

ABR WATCHES/WARNINGS/ADVISORIES

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