textproduct: Aberdeen

KEY MESSAGES

- Temperatures near to below normal, in the 60s and 70s, are forecast today, and slightly below normal this weekend. Only on Thursday and Friday are temperatures expected to warm back up to above normal in the 80s to low 90s.

- Low relative humidity values Thursday afternoon in areas west of the Missouri River, between 15-25%, is creating elevated fire weather concerns. Slightly weaker wind gusts, below 25 mph, help to lower the fire weather concern and keep the Grassland Fire Danger values in the high category.

DISCUSSION

Issued at 120 AM CDT Wed Sep 9 2026

As a cold front pushes through central and northeastern SD this morning, it will be interacting will a small bit of moisture and little bit of instability. This will cause some scattered showers, and maybe a thunderstorm or two, to form mainly over northern SD early this morning. There will be some drier air between the surface and the showers aloft, which could cause the rain to evaporated before reaching the surface. So, while there might be some showers that move through, there might not much rain reaching the surface this morning. The colder air moving in behind the cold front will help to cool temperatures to be around normal for this time of the year, with highs in the low 70s to low 80s today. A bit of higher surface pressure will be moving in today into Thursday morning. Southwesterly flow behind the high pressure will stick around over central and northeastern SD Thursday, helping to move some warm, dry air in. With the high pressure today and the dry air Thursday, shower and storm chances will stay out of central and northeastern SD.

The drier air moving in Thursday will cause some elevated fire weather concerns over central and portions of northeastern SD, as the minimum relative humidity over areas west of the Missouri River will be between 15-25%. The one thing keeping things from becoming too concerning is that there will be slightly weaker winds over the areas of lowest humidity Thursday afternoon. There is only a 20-40% chance of winds gusting 25 mph or more in portions of Corson and Lyman counties, with the rest of the counties west of the Missouri River having less than a 10% chance that the winds will be able to gust 25 mph or more. There is high Grassland Fire Danger Index Value covering Corson and Dewey counties because of how dry it will be and how easy it could be for a fire to ignite and spread with all the dry fuels. The winds and the humidity will need to have an eye kept on it over the next couple of model runs to see if the fire weather concerns increase. If it does, a Red Flag warning might be needed. The James River Valley will see the stronger winds Thursday afternoon, with 30-60% chance of wind gusting up to 30+ mph. Though the minimum relative humidity will be between 30-45%, reducing the fire weather concerns to the east of the Missouri River.

As a small upper-level ridge/shortwave moves over SD Thursday night into Friday, another surface front will be moving through central and northeastern SD. A little bit of moisture will be sneaking up over northeastern SD late Thursday night into Friday, which will be able to interact with the front to cause some showers and storms to develop Friday afternoon into the evening over portions of northeastern SD. Models do vary how quickly they move the front through central and northeastern SD, which then varies how much of the area could see showers and storms. The models that move the front through quickly have it out of northeastern SD by the afternoon, keeping precipitation chances to the south and east of northeastern SD. Other models have the front move through slower, which would then give more area in northeastern SD to build up instability and moisture for storm development during the afternoon through the overnight periods. Behind this cold front and into the weekend, temperatures look to drop slightly below normal. The next chance for precipitation will come late Saturday night into Monday with more moisture moves into the area before a surface low and frontal boundaries moves in. While models currently have widespread 50-80% chance for 0.5 inch falling Sunday and Monday, models still vary the timing and location of the surface low and associated fronts as well as the precipitation that comes along with it. This causes more widespread chances further out in the forecast that typically shrink in area and magnitude as it gets closer. This precipitation chances will need to be watched as we get closer to the weekend.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1223 AM CDT Wed Sep 9 2026

Terminals KABR,KATY,KPIR,KMBG

An upper level trough crossing the region may produce showers at KMBG early in the taf period, and perhaps KABR around sunrise. Winds will become northwesterly as the system crosses the area. Overall, flying conditions will remain VFR.

ABR WATCHES/WARNINGS/ADVISORIES

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