textproduct: Aberdeen

KEY MESSAGES

- Areas of fog to linger and perhaps expand over northeastern South Dakota and western Minnesota later tonight. Some fog may be dense, with visibilities down to a quarter of a mile or lower at times.

- Cooler temperatures will persist this week. Expect highs in the upper 40s to lower 60s. Highly dependent on whether or not the clouds clear off at night, but overnight lows could drop below the freezing mark under clear sky nights.

- Some light showers, possibly with embedded thunder, and more pockets of drizzle are expected across, at least, north central South Dakota again by late tonight, persisting into Tuesday. Generally a few hundredths of an inch are expected. Additional rain chances come late Wednesday into Thursday. - Strong northwest winds 25 to 35 mph with gusts up to 50 mph will be possible Thursday afternoon and evening across central and north central South Dakota. These winds will draw some of the coldest air of the season, to date, into the region Thursday night through Friday. Sub-freezing low temperatures Thursday night and Friday night are a concern.

DISCUSSION

Issued at 140 PM CDT Mon Oct 12 2026

At 1 PM CDT, skies are cloudy. Isolated rain showers (with some embedded thunder) and spotty drizzle continue. Fog is lifting for most areas. Still seeing some dense fog on/east of the Prairie Coteau at this time. Winds are anchored on a northerly direction around 5 to 15 mph. And, temperatures have not budged; sitting in the mid 40s to mid 50s. Temperatures across the extreme east/southeast portion of forecast zones are reading in the low to mid 60s.

Expecting the forcing/lift attached to the current shortwave working through the region to terminate by late afternoon/early evening. And, that should bring a brief end to the showers and drizzle around. However, the set-up in the low levels of the atmosphere is not going to change all that much heading into Tuesday morning. There could be another round of fog (locally dense) in the morning. Also, as additional shortwave energy lifts out of the southwestern CONUS and works up into the northern plains region, the potential for showers and perhaps even more drizzle will increase. Once that shortwave departs Tuesday afternoon, most of the CWA reverts back to a dry forecast through the end of the period. It's the area basically south of a line from Mission Ridge to Milbank that could encounter more light rainfall heading into Wednesday night/lasting into Thursday as low pressure lifts out of the intermountain west and works its way across the plains.

Ensembles clusters analysis shows the pattern de-amplifying and becoming a dry forecast period from Thursday night through the end of the period. Deterministic models are portraying something similar. Cloud cover really holds the keys as far as night time temperatures go. As long as the low clouds are in place, diurnal ranges probably don't swing much more than 5 to 10 degrees over the next couple of days. During this cool stretch, if clouds do dissipate, expect frosty conditions to be possible. Some areas could be flirting with sub-freezing temperatures either Tuesday night or Wednesday night, if skies clear off. The other timeframe of interest is Thursday night through Friday night, when models are blasting a strong cold frontal passage through the region, drawing some of the coldest air of the season down across South Dakota. Sub-freezing readings are possible Thursday night and Friday night. The frontal passage on Thursday into Thursday night could be packing some rather strong post-frontal northwest winds as well. Portions of central and north central South Dakota could be looking at advisory strength winds and/or gusts. The air temperature (925hpa) within the mixing layer on Friday is only in the 3-6C range, so high temperatures on Friday may not make it out of the 40s for some.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1244 PM CDT Mon Oct 12 2026

Terminals KABR,KATY,KPIR,KMBG

Low visbies in FG/BR/DZ, rain showers and low CIGs will continue across the region during the TAF period. MVFR/IFR/LIFR conditions are all possible during the TAF period, but particularly at KABR/KATY. CIGs are bouncing between MVFR and IFR at KPIR/KMBG, and these two terminals hold the highest potential for seeing partial clearing by early this evening. But later tonight, clouds are expected to fill back in at these two terminals. Isolated to scattered -SHRA/-TSRA in the KABR area early this afternoon should clear off by late this afternoon. Rain showers and drizzle are expected to take a break by late afternoon/early evening, and fog should burn off/mix out as well. However, later tonight into Tuesday, there should be more rain showers and areas of drizzle/fog to contend with.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Dense Fog Advisory until 4 PM CDT this afternoon for SDZ007- 008-021-023. MN...None.