588
FXUS63 KFSD 251746
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1246 PM CDT Tue Aug 25 2026

.KEY MESSAGES...

- Seasonable temperatures and dry weather prevails through
  Thursday with highs in the upper 70s and 80s, and lows in the
  50s to lower 60s.

- Warmer and more humid air returns Friday through the weekend
  with moderate (40-60%) chances for storms late Friday into
  Friday night.

- Periodic shower and storm chances continue this weekend into
  early next week. Confidence on any details is low.

&&

.DISCUSSION...
Issued at 1244 PM CDT Tue Aug 25 2026

Wednesday and Thursday both look dry and seasonally warm as surface
pressure noses in and slowly drifts east. With relatively light
northerly flow in place both days, lows will generally be in the
50s, a few 60s on Wednesday morning, with highs in the lower to mid
80s.

Thursday night into Friday weaker upper level ridging moves through
as a trough of low pressure deepens over the Northern Rockies. This
trough will continue to dig into the weekend, then expected to
spread across the Canadian border later Sunday into Monday.

This pattern change to southwest flow aloft continues into next
week and will likely bring period of showers and thunderstorms. The
best chance for now looks to be Friday night as the upper level
ridge is shoved east and warmer and more moist airs builds in.
Initially Friday the area looks too capped to produce showers and
thunderstorms. Maybe some ACCAS activity on Friday morning but even
that looks like a low probability.

The main piece of energy with this initial push moves through Friday
night and should bring scattered showers and thunderstorms. For now
the severe weather threat appears to be fairly low. Another wave
moves into the Western High Plains on Saturday which should bring
enhanced heating ahead of a weak front. This could be a brief period
of thunderstorms and isolated severe, but too far out to determine
just yet. Moderate shear and minor to moderate instability are
possible.

Sunday into Monday gets a bit messier with some timing difference on
the exiting and lifting northeast of the main upper level jet. The
models suggest that the right entrance region will exit to the
northeast sometime Sunday night into Monday afternoon which could
serve as our next better chance for showers and thunderstorms.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1208 PM CDT Tue Aug 25 2026

A weak cool front will turn winds to the northwest early this
afternoon. Winds could gust to around 15-20 mph briefly.
Otherwise VFR conditions are expected.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...08
AVIATION...08