textproduct: Aberdeen

KEY MESSAGES

- Mainly dry conditions will continue through next Wednesday. However, there is a 30-60% chance for showers and thunderstorms during the day Sunday over central SD, and Sunday night across much of central to northeastern SD.

UPDATE

Issued at 1235 AM CDT Fri Aug 21 2026

Updated for 06Z Aviation Discussion below.

UPDATE Issued at 738 PM CDT Thu Aug 20 2026

Severe convection threat is done. Cold front cleared the CWA about an hour and a half ago. Now waiting to see how long it will take surface high pressure up north to work its way down into the northern plains. Current gridded forecast package is in fine shape. No changes planned to the tonight period.

UPDATE Issued at 616 PM CDT Thu Aug 20 2026

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

DISCUSSION

Issued at 215 PM CDT Thu Aug 20 2026

Low pressure centered over northwestern MN at 18Z today is draping a cold front across southeastern ND and from around Aberdeen to just east of Pierre. While winds are light and variable near the boundary, they have been out of the west to southwest with gusts 25-37mph over portions of east central SD (mainly near the east of I-29) early this afternoon, and gusting out of the northwest 20-25kts behind the front. We'll continue to watch this front as it shifts east, with the potential for thunderstorm initiation over east central SD and east mid to late afternoon. The highest potential for showers and storms over our eastern most counties still looks to be around 5-8 PM (22-01Z). We'll continue to monitor the latest trends for this afternoon as these storms could quickly produce hail or strong winds. The highest potential for development remains to our south and east.

A milky sky remains from smoke streaming in from the northwest. The EPA/USFS fire.airnow.gov site has shown degrading air quality over portions of central SD. While most upstream locations over MT have improved to over 6SM visibility, we still have about a 2-3 hour period over portions of central SD where vis may briefly fall to around 6SM before improving.

The cold front will sink to our southeast by 03Z as the surface low shifts across central to northeastern MN. 1020mb high pressure currently over southwestern Canada will shift across Manitoba Friday as a weak surface trough/secondary cold front clips our north and northeastern counties. While the forecast is currently dry, we will need to monitor the latest trends as a 20% chance of showers or an isolated thunderstorm isn't completely out of the question. An hour or showers or thunderstorms may also move across our far southern counties as a weak wave/cold front move across mainly northern NE.

Expect the slow moving surface high to push across Manitoba and ND Saturday with the trough in place across SD, before moving into MN Saturday evening into Sunday. The main result for our area, with a lee trough setting up to our west will be increasing winds out of the southeast. There is a 40-60% chance of wind gusts over 35 mph Sunday mainly west of the MO River (highest chances west of Mobridge and south of Pierre). Wet weather returns Sunday, with a 30-60% chance of showers and thunderstorms Sunday into Sunday night. Some of the NCAR Medium-range Real-time AI NWP convective hazard forecasts continue to highlight 12Z Monday-12Z Tuesday as our next potential for strong to severe storms aligning with the next surface low crossing southern Canada and dragging a cold front across our area. There's enough differences in the solutions to only have around a 20% chance of showers/storms at this time, but it will be another time period to watch. There are some significant differences in the overall 500mb pattern as we move into Thursday of next week, with a 33% chance of the dominant ridge to our west moving overhead. However, more of a northwesterly flow pattern looks to be more likely with the ridge staying west. No large-scale pattern changes are anticipated.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1235 AM CDT Fri Aug 21 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will prevail at all sites, but there are a few items of note. First, could see a little bit of fog at KATY early this morning, but HREF probs of MVFR vsby are only 15%, so didn't mention and will monitor. Second, expect 7-12kft clouds this afternoon/evening at KATY/KABR and potentially a shower brushing the sits between 21Z-03Z today. At this time, confidence is too low to mention (only 15% chance and would expect conditions to remain VFR). Finally, smoke upstream in Canada will push through the area today, leading to a potential smoke layer between 9-15kft.

ABR WATCHES/WARNINGS/ADVISORIES

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