607
FXUS63 KABR 210620
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
120 AM CDT Wed Oct 21 2026

.KEY MESSAGES...

- Temperatures continue to be about 10 to 15 degrees above normal
today, with highs in the upper 60s to low 70s. By the end of the
week temperatures are forecast to be 20 to 25 degrees above normal,
ranging in the 70s to potentially the lower 80s.

- Rain chances return Friday with a 30-50% of showers and a storm or
two Friday and Saturday. The percent chance of rainfall amounts of
0.10 inch or more is 40-60% over eastern SD and a 20-40% chance for
0.25 inch of rainfall.

- Warm and breezy conditions will lead to elevated fire weather
concerns across central South Dakota Thursday with more widespread
concerns Friday.

&&

.DISCUSSION...
Issued at 120 AM CDT Wed Oct 21 2026

A weak cold front has been moving through central and northeastern
SD and west central MN this morning. This cold front will not be
cooling temperatures too much today, as highs in the upper 60s to
low 70s will still be 10-15 degrees warmer than normal. This front
will cause the winds to turn and be from the northeast to easterly
during the day and then turn overnight to be from the south. The
southerly winds will be bringing in warmer temperatures Thursday and
Friday, with highs in the upper 70s to low 80s. These temperatures
will be about 20-25 degrees warmer than normal for this time of the
year, and some areas will get close to and potentially break record
warm temperatures.

While high pressure develops over the Great Lakes to the east, a
surface low pressure will develop over NV and move to the north
northeast over western MN and then into Manitoba Canada Thursday
into Saturday. With these two strong pressure centers on opposite
sides of SD, the pressure gradient over the state will tighten. This
will cause winds to strengthen Thursday through Friday night over
the state, starting in central SD Thursday afternoon and spreading
east overnight into Friday. While Thursday`s winds will be strong,
with gust up to 35 mph possible. Friday will have the strongest
winds. There is a 30-60% chance for winds to be sustained at or
greater than 30 mph and 20-50% chance for gusts to be at or greater
than 45 mph Friday through Saturday morning, mainly over the Coteau
and areas west of the Missouri River. These strong winds will be
increasing the fire weather concerns Thursday and Friday, as ground
fuels are starting to cure and dry out in this fall weather. The
grassland fire danger index values are forecast in the high category
over portions of central SD Thursday and over central and
northeastern SD Friday. The one thing stopping the fire danger from
being greater is higher relative humidity values. Humidity values
will be between 35-50% on Thursday and 35-55% on Friday, which will
help to keep fires from starting. However if a fire were to start,
it could become difficult to control or suppress.

While the low pressure system will not be moving over SD, the fronts
attached to it will be. A warm front will be moving over SD Thursday
and sticking around into Friday, which is what is causing the warmer
temperatures to move in SD during those days. The models are
forecasting the warm front to start moving again on Friday, which
will interact with moisture aloft to cause scattered showers and
potentially even a storm or two. The models however vary where the
warm front will be when rain starts to develop, and some of the
models even have the rain missing the state. The next chance for
rain showers from this system will be when a cold front moves
through central and northeastern SD Friday night through Saturday.
The models vary how long the cold front sticks around over eastern
SD on Saturday, which then varies how much rainfall will occur.
There is a 40-60% chance for 0.10 inch or more of rain over portions
of eastern SD and west central MN from the Friday and Saturday rain,
and a 20-40% chance for 0.25 inch over the same area. There is still
lower confidence in the timing, track, and rainfall amounts due to
the variability in the frontal boundaries in models. This will need
to be watched in upcoming model runs to see if they start to show
similar conditions. The one thing the models do agree on, is that
there will be cold air moving in behind the cold front Saturday,
which will cause temperatures during the weekend to be around normal
for this time of the year.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1230 AM CDT Wed Oct 21 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through the TAF period. Surface winds
will eventually switch to the north or northeast as a frontal
boundary passes through the region.

&&

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

&&

$$

DISCUSSION...12
AVIATION...10