023
FXUS63 KABR 090621
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
121 AM CDT Wed Sep 9 2026

.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.

&&

$$

DISCUSSION...12
AVIATION...17