996
FXUS63 KABR 050640
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
140 AM CDT Sat Sep 5 2026

.KEY MESSAGES...

- There is a Marginal risk (level 1 out of 5) for severe storms over
central and northeastern SD and west central MN this afternoon into
tonight. The primary hazards will be 1 inch in diameter hail and 60
mph wind gusts.

- There is a Marginal risk (level 1 out of 5) for severe storms over
portions of north central SD and northeast SD into west central MN
Sunday afternoon into the evening hours. Main hazards will be 1 inch
diameter hail and 60 mph wind gusts.

- Our warming trend continues into the weekend, peaking at 15 to 20
degrees above normal today. Highs in the low 80s over northeastern
SD to upper 90s over central SD are expected. Higher humidity values
over central SD will lead to heat index values in some places to get
into the triple digits.

&&

.DISCUSSION...
Issued at 140 AM CDT Sat Sep 5 2026

As an upper-level shortwave has moved over SD last night into this
morning, scattered showers and storms continue to pop up and move
over areas east of the Missouri River. The low level jet has set up
over the area and has been helping to develop and support these
showers and storms and it will continue to support them into the
morning. Confidence in the timing of showers and storms is a bit low
this morning, as the high-res models have had a harder time
correctly showing what is actually happening when they initialize,
which makes a person have a harder time trusting what the models
have happening later on in the run. With warm, moist air continuing
to move into central and northeastern SD, the environment is primed
for showers and storms to continue to develop early this morning.
CAPE values this morning are between 1000-2000 J/kg over central and
northeastern SD. There are mid-level lapse rates of 7-8 C/km and
about 30-40 kts of shear in the environment. While so far the
scattered pulsy showers and storms haven`t become severe, if they
are able to get strong enough to tap into the environment and the
support of the low level jet, then they could become severe. If that
happens, then the storms could have hail up around 1 inch in
diameter and wind gusts of 60 mph. After the low level jet dies back
this morning, the showers and storms will likely back off for a few
hours.

More warm, moist air will be pushing into central and northeastern
SD today. Temperatures will be getting up into the low 80s over far
northeastern SD and increase to the west with highs in the upper
90s. The higher humidity values will cause the heat index values
over central SD to increase and get into the triple digits in some
areas. After the showers and storms move through this morning, the
heat and humidity will help to increase CAPE values back up to 1000-
3000 J/kg this afternoon and tonight. 850mb temperatures will also
be warmer today, with models showing temperatures between 20-28
degrees C. These temperatures will help to place a pretty decent cap
over central and northeastern SD. This will likely be a similar
situation to yesterday, where there will be scattered junky and
pulsy showers and storms that start to pop up in the afternoon along
the surface trough in the Rockies and the attached frontal boundary
that stretches from northwestern to southeastern SD and showers and
storms will continue this pattern through the night. However, with
the potential for an upper-level shortwave to provide support to the
storms at some point as well as an environment conducive to severe
storms if they can break through the cap, some storms could become
severe. Lapse rates late this afternoon into tonight will be between
7-8 C/km and bulk shear will be between 35-45 kts. With this
environment in place, there is a Marginal risk (level 1 of 5) for
storms to become severe, with hail up around 1 inch and wind gusts
of 60 mph possible. Confidence in timing for these storms is low due
to the cap that will be in place and not knowing where and when
something might be able to break through a weak point.

While moisture will continue to move in over central and
northeastern SD Sunday and Monday, the surface temperatures will
cool slightly. High temperatures these days will be in the low 80s
to low 90s. Instability will start to increase again over central SD
Sunday, with CAPE values in the afternoon into the nighttime hours
between 1000-2000 J/kg. As more upper-level shortwaves move over SD,
they will be able to provide support for showers and storms to
continue to develop along the surface trough and frontal boundary
that have parked themselves over the state. Slightly cooler
temperatures aloft will help to weaken the cap slightly, however
with 850 temperatures still looking to be between 18-24 degrees C,
there will still be a cap to limit storm development. As with
yesterday and today, there could be junky, pulsy scattered showers
and storms through the afternoon and night in this environment.
Lapse rates look to be slightly weaker Sunday, between 6-7 C/km, as
well as a bit weaker shear over the area compared to today. If a
storm is able to break through the cap, there is a marginal chance
(level 1 of 5) it could become severe Sunday afternoon through the
overnight. The primary hazards will be hail up to 1 inch and wind
gusts of 60 mph. While the start of Monday looks to have similar
conditions, an upper-level trough will be pushing the ridge that
sits over the area out, while also providing support for a cold
front to push through overnight Monday into Tuesday. This will have
more storms along it, but once the front pushes out of central and
northeastern SD, we will finally get a little break from the pattern
we have been stuck in as well as some cooler temperatures.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1236 AM CDT Sat Sep 5 2026

Terminals KABR,KATY,KPIR,KMBG

Widely scattered -SHRA/SHRA and -TSRA/TSRA will continue across
the region through the wee hours of Saturday morning, and
perhaps beyond sunrise. KABR/KATY stand the best chance to see
activity near/over the terminals, so have included VC (vicinity)
and TEMPO to account for this. Could see brief MVFR VSBY under
heavier showers. Cannot rule out some BR/FG and patches of IFR
CIGs near KATY up through sunrise as well, but confidence is
fairly low now and will leave mention out of TAFs at this time.
Additional shower/thunderstorm chances later Saturday afternoon
and evening across the region, but confidence is low on location
and areal coverage.

&&

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

&&

$$

DISCUSSION...12
AVIATION...TMT