textproduct: Aberdeen

KEY MESSAGES

- Northwest wind 15 to 25 mph with gusts of 30 to 40 mph, low relative humidity, and dry cured fuels will create elevated fire weather conditions mainly over north central SD today.

- Temperatures closer to normal (highs mid 70s to mid 80s) are forecast for Today and Wednesday, with below normal temperatures, in the 60s to low 70s, forecast Sunday and Monday.

DISCUSSION

Issued at 122 AM CDT Tue Sep 8 2026

As an upper-level trough continues to push east today, it will be suppressing the upper-level ridge that has be stuck over SD. This upper-level trough will continue to help a cold front at the surface finish moving through northeastern SD during the morning. There is a little bit of warm air and moisture trying to advect into portions of south central and northeastern SD in front of the the cold front early this morning. The warm air and moisture advecting in as well as a weak low level jet sitting over the area again is creating some more of the elevated scattered showers and storms, similar to what has been happening the past few mornings. These showers and storms will have a little bit of shear and some lapse rates, around 5-6 C/km, to strengthen a bit, though they should stay below severe criteria. As the cold front moves through this morning, these showers and storms should dissipate as dry air moves in.

Behind the cold front, some high surface pressure will move through southwestern SD while a low pressure sits over Manitoba and Saskatchewan, which will help to create a tight pressure gradient over ND and northern SD. This tight pressure gradient will cause stronger winds to develop aloft, and with stronger lapse rates and cold air advection occurring, there will be a fair bit of mixing in the atmosphere to get these winds down to the surface over north central SD. The ensembles have a 30-50% chance for the northwest winds to gust around and greater than 40 mph, and 50-80% chance for 35+ mph wind gusts over mainly Corson and Dewey counties. The HREF models has slightly weaker winds chances over north central SD, with a 40-80% chance for winds to gust greater than 30 mph. While these winds are weaker than wind advisory criteria, they are a big point of concern for fire weather in portions of north central SD. There is a 20-40% chance that conditions mainly in Dewey county but also other portions of north central SD will reach Red Flag criteria, which is wind gusts greater than 25 mph and relative humidity values less than 20% in addition to dry fuels. The main cause for these lower chances is because the humidity values will be slightly above 20%. When checking the models for wind gusts greater than 25 mph and humidity less than 25%, then the chances shoot up to 50-80% over Dewey county and slightly lower over other portions of north central SD. While the conditions do not reach Red Flag criteria, there is still Very High to High Grassland Fire Danger Index Values and some fire weather concerns for Dewey, Corson, and other portions of north central SD this afternoon. With the dry fuels in these areas in combination with the weather conditions, if a fire were to ignite, it would become difficult to suppress or control.

Temperatures today behind the cold front will be around to just slightly above normal for this time of the year, in the upper 70s to mid 80s. Another surface cold front is forecast to move through SD again tonight into early Wednesday morning. The RAP model shows there to be a little bit of instability over portions of northern SD tonight, with CAPE values less than 1000 J/kg, as well as a little bit of lingering moisture aloft. The cold front could interact with this environment during the overnight hours into Wednesday morning to create some isolated to scattered showers and storms over portions of central and northeastern SD. While there will be a fair bit of shear from the frontal boundaries, the lapse rates will be a bit weaker. This will help the showers and storms from becoming severe. However, with the stronger shear, around 45-60 kts, even some weaker lapse rates could get strong winds to the surface and the storms could have gusts up around 50 mph.

The second cold front will help to cool temperatures even more on Wednesday, with highs in the 70s possible. A weak upper-level ridge will be moving over SD Thursday and Friday, which will help to move some warm, drier air in again, with highs these day in the low 80s to low 90s. A surface high pressure moving in Wednesday afternoon through Thursday night along with the drier air aloft will help to keep showers and storms from developing for a couple of days. The next chances for precipitation will be during the day and evening Friday as another frontal boundary moves through.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1210 AM CDT Tue Sep 8 2026

Terminals KABR,KATY,KPIR,KMBG

Prevailing VFR conditions can be expected for all terminals through the valid TAF period. KABR and KATY could see low level wind shear early in the TAF period. A frontal boundary sliding across the area will shift the winds to a northwesterly direction and become gusty at times, especially for KMBG.

ABR WATCHES/WARNINGS/ADVISORIES

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