125
FXUS63 KABR 121830
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
130 PM CDT Wed Aug 12 2026

.KEY MESSAGES...

- There is a Slight (level 2 of 5) to Marginal (level 1 of 5) risk
for severe storms to develop this afternoon west river, migrating
east through the evening and overnight. Main threats include wind
gusts of 60 to 70 mph and hail up to 1 inch in diameter.
Additionally, heavy rainfall could lead to localized flooding in a
few areas.

-Some wildfire smoke has the ability to make it to the surface this
evening over portions of northeastern SD. This smoke could reduce
air quality slightly and cause some issues to those who are
sensitive.

-Next chance for showers and storms will be Thursday night into
Friday morning over central and northeastern SD. These storms are
forecast to stay below severe criteria.

&&

.DISCUSSION...
Issued at 130 PM CDT Wed Aug 12 2026

Wildfire smoke will continue to move in today. While most of this
smoke will stay above the surface, portions of northeastern SD could
see some of this smoke get to the surface. The concentration of
smoke will not be enough to cause a decrease in visibilities, though
the air quality will drop into the moderate Air Quality Index
category. Those who are sensitive to air pollutants could be
impacted slightly. Temperatures today are on track to be around
normal, with highs in the 80s.

As a weak upper-level shortwave moves over SD this afternoon into
the evening, a surface boundary will be moving into central and
northeastern SD. This shortwave and surface boundary will help to
provide some forcing for shower and storm development today as they
move over an area with some instability. The models are showing CAPE
values of 1000-2000 J/kg over central and portions of northeast SD
this afternoon into the evening, decreasing as the surface boundary
moves in. Mid-level flow from the intermountain west will help to
move in moisture in the mid-levels and create a bit of an inverted-V
sounding. The inverted-V sounding indicates 2 things: that the
convection will likely be elevated, and that strong winds from
microbursts will be possible in the storms. There is a slight (level
2 of 5) to marginal (level 1 of 5) risk that any storms that
develops could become severe, with the highest risk for severe
storms over south central SD. The main hazard will be strong wind
gusts of 60-70 mph. Even though there will be weaker lapse rates, if
any isolated cell does develop in front of the boundary, there is a
risk for hail up around 1 inch. Additionally, with the moisture
moving in from the intermountain west helping to feed the storms,
there could be heavy rainfall at times. If multiple cells were to
move over the same area, that rainfall could add up and create
localized flooding at times. These storms should move out of central
and northeastern SD during the early overnight hours, with the
potential for a few lingering showers into early Thursday morning.

Behind the surface boundary, cooler air will be moving in Thursday.
This will cause temperatures to fall slightly, to be about 5 to 10
degrees below normal through the weekend. High temperatures will be
in the 70s during this time. There is a little bit of variability in
the models as to precipitation chances Thursday. Some models keep
some isolated showers and storms over central and northeastern SD
Thursday morning and afternoon, while other models keep the showers
and storms out of the area. The next larger chance for showers and
storms to move in will be Thursday night into Friday as the Lee of
the Rockies surface trough starts to move over and through SD.
Models show very weak instability over northeastern and central SD
as well as weak lapse rates and shear. Because of this, these
showers and storms will likely stay as weak storms with little
chance to become severe.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1232 PM CDT Wed Aug 12 2026

Terminals KABR,KATY,KPIR,KMBG

Mainly VFR/MVFR conditions will be around this afternoon and
evening, except for some IFR at KPIR due to low clouds for another
hour or so, before some showers and storms start to move in over the
terminals. The storms have a marginal risk (level 1 of 5) to become
severe if they develop, with occasional strong wind gusts of 60-70
mph possible. These showers and storms will be moving out during the
evening and early overnight hours. KATY could see some wildfire
smoke reaching the surface this evening, though this smoke should
not affect visibility and ceilings.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.

&&

$$

DISCUSSION...12
AVIATION...12