textproduct: Aberdeen

KEY MESSAGES

- Scattered rain showers to weak thunderstorms will continue this afternoon. As showers move eastward into northeastern SD and western MN tonight, coverage will become more dense and rain rates will increase. Through Thursday morning, there is a 60-90% chance to see a quarter of an inch of rain or more along and east of the James River.

- Another round of rain arrives Friday afternoon into Saturday morning. There is a 30-60% chance to see a quarter of an inch through more through Saturday morning.

- Expect temperatures near normal for the next few days, with highs in the upper 60s to low 70s. Signs point towards a cooldown next week.

UPDATE

Issued at 832 PM CDT Wed Sep 23 2026

Only changes to the tonight period forecast are minor adjustments to the PoPs, as guidance suggests the convection working toward Corson county will not last much longer, but the night-time showers/embedded thunder that gets going later tonight is still expected to happen, but maybe not beginning until closer to midnight or later/just a little bit delayed for start time and lingering a bit longer into Thursday morning. Updates are out.

UPDATE Issued at 625 PM CDT Wed Sep 23 2026

See below for an aviation forecast discussion for the 00Z TAFs.

DISCUSSION

Issued at 220 PM CDT Wed Sep 23 2026

A low-level jet over the region is the driver behind both scattered rain showers and gusty southerly winds this afternoon. Expectations for the rest of the day are that showers will continue to develop and move slowly eastward through the rest of today and through the overnight period. The vast majority of these showers will have very light rain rates this afternoon, although some higher rain rates and a stray rumble of thunder or two may be possible in the strongest showers. As the low-level jet moves eastward tonight, more widespread development will take place. Stronger rain rates are expected in this development, and around a quarter of an inch will fall along and east of the James River (60-90% chance from the NBM). Perhaps up to a half inch or more may fall through Thursday afternoon, beyond which rain is expected to be out of the area. The other impact of the low-level jet's progression to the east is that gusty winds up to 30-35 miles per hour are expected to persist over northeastern South Dakota and western Minnesota overnight tonight and into early Thursday morning.

An upper-level trough based over the Pacific Northwest will eject a shortwave into the region late Friday into Saturday, bringing about the next chances for rain. Once again the best chances for rain will be during the overnight period. Through Saturday morning, chances to see a quarter of an inch sit at around 30-60%, with the highest located along the James River. There is still a fair degree of spread with this system however, and amounts as high as half an inch to even an inch of rain through Saturday morning are very much in play. This system is expected to exit by Saturday afternoon.

Early next week, another upper-level trough over the Pacific will progress eastward to be over the western CONUS while deepening. This trough will develop a low pressure center that will move into the Northern Great Plains, bringing about additional chances for rain into the region. There is still a bit of uncertainty in the timing of this rain, but best chances are currently Monday afternoon through overnight. Current ensemble medians highlight eastern South Dakota and Western Minnesota for the area of highest rainfall totals, and ensemble medians in that area sit anywhere between 0.5"- 1.5" through Wednesday morning. NBM probability to see 1" total over that same Monday-Wednesday time period peaks at 50-70% along and east of the James River. Mid-to-long-range machine learning models do hint at some severe potential with this system on Monday, so that will be something to keep an eye on as this event draws closer.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 625 PM CDT Wed Sep 23 2026

Terminals KABR,KATY,KPIR,KMBG

MVFR stratus still covers portions of north central and northeast South Dakota early this evening. After 03Z, MVFR/IFR cigs are forecast to fill back in across all four terminals on south-southeasterly breezes. Overnight, showers should develop and steadily increase in coverage into northeast South Dakota and west central Minnesota. The stratus layer should be deep enough to support areas of drizzle, as well. Something to watch for overnight. Rain rates are generally expected to be light, so visibilities should remain VFR/MVFR in showers/drizzle. Covering the precipitation potential with a mix of tempo's, prob30's and prevailing (fm's).

Back to the winds...generated by a low level jet/pressure gradient, that will slowly progress eastward through tonight and Thursday, southeast winds 10 to 20 knots with occasionally higher gusts starts things off tonight. While winds will die down overnight over central South Dakota, expect gusty winds to persist through the TAF period over northeastern South Dakota and western Minnesota.

ABR WATCHES/WARNINGS/ADVISORIES

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