018
FXUS63 KABR 131831
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
131 PM CDT Thu Aug 13 2026

.KEY MESSAGES...

-Isolated showers and weak storms will continue to pop up over
portions of south central and east central SD this afternoon into
the evening. If a storm does pop up, it is expected to remain sub-
severe and short in duration.

-20-30% chance for some scattered non-severe storms and showers to
develop or move into portions of central SD late Friday afternoon
into the evening.

&&

.DISCUSSION...
Issued at 131 PM CDT Thu Aug 13 2026

As of 18z, there are currently some isolated showers lingering over
portions of south central and east central SD. These showers are
slowly moving around and then dissipating after not too long. The
environment has a touch of instability, with between 250-500 J/kg
over south central and east central SD. This could help with the
development of occasional showers and weak & non-severe storms over
portions of central and east central SD this afternoon and evening.
Otherwise, central and northeastern SD will stay dry as showers and
storms stay to the south and west through the overnight hours.

The upper-level ridge that had kept northwest flow over SD through
the past week has finally shifted to the east over the southeastern
US. With this ridge moving east, the upper-level flow has switched
to be from the southwest through the weekend. This southwest flow
will start to push the wildfire smoke aloft and at the surface out
of central and northeastern SD today and into Friday. There could be
a bit of smoke aloft over northern SD through the evening before it
moves out. Temperatures today and into the weekend will be about 5-
10 degrees below normal, with highs in the 70s.

The lee of the Rockies surface trough will slowly be pushed to the
east by the southwest flow Friday. This surface boundary is forecast
to move over central SD late Friday afternoon and into the evening.
This will provide support for the next chance for showers and storms
to develop, as the boundary will move into an environment with lots
of moisture and some weak instability. The NAM and RAP show CAPE
values in western SD getting up into the 1000s J/kg while central SD
will see values around 500 J/kg. While the values are a bit weaker,
it could still be enough to help storms develop in central SD or
have storms develop in western SD and then move into central SD.
There does look to be lower lapse rates and shear values, which
helps to increase the confidence that if any storms develop, then
they will stay non-severe. These storms could have some stronger
wind gusts at times. As the surface boundary shifts east over
northeastern SD during the overnight hours, the storms look to
dissipate. This is because the environment is even weaker and there
is nothing to support the storm, such as a low level jet which will
develop in ND. A cold front along the back side of this surface
boundary looks to move through central and northeastern SD Saturday
morning. This could cause an isolated shower or two to pop up
through the day Saturday.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1225 PM CDT Thu Aug 13 2026

Terminals KABR,KATY,KPIR,KMBG

There are scattered showers over and around KATY early this
afternoon with some isolated rain showers possible through the
overnight over central South Dakota, which could affect KMBG and
KPIR. While there is a higher cloud deck over KATY, KABR, and KMBG,
KPIR will be dealing with lower ceilings for a few more hours before
the cloud deck rises. VFR and MVFR conditions are expected into
Friday. Winds will be from the east through the night, with gusts up
around 25 mph possible over KPIR, KATY, and KMBG through the
afternoon and over KABR, KATY, and KMBG during Friday morning.

&&

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

&&

$$

DISCUSSION...12
AVIATION...12