858
FXUS63 KABR 301953
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
253 PM CDT Thu Jul 30 2026

.KEY MESSAGES...

- A Slight Risk (level 2 out of 5) for severe weather is in place
over portions of central and south central SD this afternoon and
tonight. A Marginal Risk (level 1 of 5) for severe weather is in
place for the rest of the forecast area. The main hazard will be
wind gusts of 60-70 mph and hail of one inch in diameter.

- Through Friday morning, much of northeastern South Dakota and
western Minnesota could see around 1.5"-2" of rain. Localized areas
of 3" or more inches could be possible, and Flash Flooding will be
possible in places that see these higher end rainfall totals.

- Temperatures into the upper 90s to low 100s return over parts of
central and north central South Dakota this weekend. Temperatures
are set to cool down to below normal by the middle of next week.

&&

.DISCUSSION...
Issued at 253 PM CDT Thu Jul 30 2026

The main challenges in this forecast package will continue to
revolve around the chances for severe weather and locally heavy
rainfall the remainder of today into tonight and Friday morning. Mid
afternoon satellite/radar imagery indicate ongoing active weather
across this forecast area. Showers and thunderstorms have continued
to evolve across northeast SD/west central MN early this afternoon
while the area of showers/storms the moved across south central SD
through the first half of the day have shifted into southeast SD.
development of more robust convection has taken place over the last
hour or so across parts of far south central SD, south of the I-90
corridor. This activity appears to be shifting east-southeast and
may clip our far south/southwest zones this afternoon where a Severe
Thunderstorm Watch has been issued until 9 PM CDT tonight.

The disturbance partly responsible for this active pattern today is
in the form of a mid level shortwave trough that is working into
western SD this afternoon. The lead shortwave ahead of this feature
was responsible for this mornings activity has shifting east and
southeast. This upper level disturbance is encountering a modestly
unstable air mass with MLCAPE values ranging between 2000-3000 J/kg.
So, there`s enough instability for storms to continue. However, deep
layer shear remains mostly lacking across most of our CWA, outside
of far southern zones and perhaps near the ND/SD border region where
0-6 KM bulk shear values range between 25-30 kts. Weak flow in the
low to mid levels of the atmosphere have played havoc on the
evolution of convection and thus hi-res guidance has had a tough
time discerning what comes of all of this. Also, outflow boundaries
created by existing or earlier convection is also playing or will
play a role in future storms as the latter half of the afternoon and
evening wear on. So, best chances for severe weather for the
remainder of this event the rest of today and tonight will be across
parts of central and south central SD. Initial discrete cells will
be capable of large hail but with time, storms will evolve into more
clusters or linear mode and the threat will become damaging winds.
Perhaps the more widespread threat across most of the forecast area
will be locally heavy rainfall. A Slight Risk for Excessive Rainfall
remains posted for most of the forecast area with our eastern half
of zones having the best chance for seeing 1-2 inches of rainfall.
Some localized amounts of 3 inches or more will be possible,
especially from parts of west central MN into east central SD south
and west into sections of the James Valley and far south central SD.
These area will have the best chance to see localized flash flooding
with any storms. The slow moving nature of this convection will only
help contribute further to the flooding possibilities.

The upper level disturbance shifts south and east of the area on
Friday. Lingering rains across our eastern zones will diminish by
midday leaving drier condition to settle in during the afternoon.
High pressure building in from the north will lead to breezy north
to northeast winds on Friday. Temperatures will remain close to
normal if not slightly below normal(especially eastern zones) on
Friday. Upper ridging is progged to build into the region through
the course of the upcoming weekend. This will bring back the heat to
the region, especially across central SD. Temperature progs indicate
those locations will be back into the 90s to around 100 degrees
Saturday into Sunday and to a certain extent on Monday. Southerly
flow returns and with a tighter gradient developing by late in the
weekend and a drier air mass, elevated fire weather conditions are
expected to develop across parts of central and north central SD.
After another fropa early next week, a cooler than normal air mass
will infiltrate the area by Tuesday through the middle of next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1238 PM CDT Thu Jul 30 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected to prevail at all TAF sites through
this forecast period outside of times when showers and
thunderstorms will be moving through the 4 aerodromes.
Increasing coverage of showers and thunderstorms are expected
this afternoon into tonight. Low confidence remains on timing
and placement of this activity through the period. Tried to
leverage the timing in the direction of best chances for
SHRAs/TSRAs in prevailing groups while using PROB30 groups for
durations where activity could be more widely scattered. MVFR
cigs/vsbys will be possible in the heavier SHRAs/TSRAs with more
widespread MVFR/IFR cigs/vsbys developing overnight at
KABR/KATY due to low stratus and fog. Southerly winds will
eventually become north to northeast late tonight/early Friday
and become gusty by late in this forecast cycle.

&&

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

&&

$$

DISCUSSION...Vipond
AVIATION...Vipond