324
FXUS63 KABR 061926
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
226 PM CDT Sun Sep 6 2026

.KEY MESSAGES...

- There is a Marginal risk (level 1 out of 5) for severe storms and
heavy rainfall over portions of northeast SD into west central MN
into the evening hours. Main hazards will be 1 inch in diameter hail
and 60 mph wind gusts and an isolated flash-flooding threat.

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

- Hot temperatures for September will persist into Monday. Highs in
the low 80s over northeastern SD to mid 90s over central SD are
expected for the next couple of days.

- Northwest wind 15 to 30 mph and gusts of 30 to 45 mph, low
relative humidity, and dry cured fuels may result in fire weather
concerns on Tuesday.

&&

.DISCUSSION...
Issued at 225 PM CDT Sun Sep 6 2026

At 2 PM CDT, except for portion of the west river counties (edge of
cloud shield, skies are cloudy due to earlier and ongoing
thunderstorms over the region. Temperatures have struggled to warm
up through the cloud-cover, with most of the forecast area
registering temperatures in the 60s and 70s. Those locations across
the far western CWA in sunshine have warmed into the 80s. Outside of
thunderstorms, winds range from the southwest to the southeast
generally in the 10 to 20 mph range with gusts to 30 mph.

The ensembles/deterministic GSM`s all continue to point to the
unfolding of this omega block pattern (a wave pattern change) by mid-
week as western CONUS energy/upper troffing works east across
southern Canada/northern tier states and flattens the flow out to
nearly zonal. This pattern change is forecast to hold into this next
weekend.

A more zonal flow pattern should knock the edge off all the
warmer/more humid than usual conditions of late. Guidance shows a
steady drop in temperatures from 80s/90s to 70s/80s once the first
cold front pushes through the CWA Monday/Monday night.

Showers and thunderstorms are dissipating across north central South
Dakota (at the time of this writing). However, convective coverage
should increase across the far eastern CWA forecast zones from late
this afternoon through late this evening while the best mid/upper
level forcing and lift overlaps the greatest instability/lapse
rates. And the biggest concern/threat through this evening with
convection is heavy rain/flash-flooding potential. With very little
in the way of deep layer shear, and sitting underneath the axis of
the upper level ridge, storm motion is only about 10 to 20 mph. So,
slow-moving heavy rain-capable storms could pose a flooding threat.

Otherwise, convective chances should take a break during the
overnight hours, returning on Monday (potentially as early as Monday
morning in the form of pre-cold-frontal showers/storms) when energy
within the western CONUS upper trof lifts out onto the northern
plains. Storms may be able to form in a pre-frontal surface trof
over the far western Dakotas and race off to the east in the morning
to early afternoon hours. A second round of storms may develop along
the actual cold front, itself, and move eastward into Minnesota
during the afternoon through late evening hours. SPC has the
forecast area in a marginal risk for severe thunderstorm on
Monday/Monday night.

Otherwise, the forecast turns dry and cooler for much of the rest of
the week. PoPs return by the weekend when the next upper trof is set
to work over the region. Still keeping a close eye on Tuesday for
fire weather concerns (low humidity and 15-30 mph northwest winds
with higher gusts).

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1230 PM CDT Sun Sep 6 2026

Terminals KABR,KATY,KPIR,KMBG

A slow moving storm system will produce showers and
thunderstorms through the afternoon and evening hours. The
strongest storm activities will cause IFR/MVFR conditions due to
heavy rainfall. Wind gusts will also be sporadic with
thunderstorms. The storm activity has push east of KPIR with
prevailing VFR conditions expected through tonight.

Another round of showers and storms will progress eastward
across the region on Monday morning, mainly between 12-18Z. Will
add PRO30 to account for some uncertainty with storm track.

&&

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

&&

$$

DISCUSSION...10
AVIATION...17