279
FXUS63 KUNR 071917
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
117 PM MDT Fri Aug 7 2026

.KEY MESSAGES...

- Wildfire smoke continues at least through Saturday.

- Mostly dry through Saturday, chance for showers/storms over
  south central SD Saturday morning.

- Warmer the remainder of the weekend, then cooler Monday through
  the forecast period.


&&

.DISCUSSION...(This Evening Through Friday)
Issued at 1232 PM MDT Fri Aug 7 2026

Current upper air models show mild ridge over the far western
CONUS, with trough over the Great Lakes region, and northwest flow
over the forecast area. Surface analysis depicts high pressure
over the Dakotas, with a low over south central MT. Winds are
relatively light and variable this afternoon. Skies are clear
with temperatures currently in the 70s to low 80s.

Winds will slowly transition to out of the southeast as we
progress through the afternoon, as the surface high slides east of
the forecast area, with dry and mild conditions continuing the
rest of today. Strengthening Low Level Jet tonight will increase
chances for precipitation in the overnight hours, mainly over
south-central SD. MU CAPE values in the 1500-2000 j/Kg range,
along with steepening lapse rates and shear in the 35-45kt range
will support chances for elevated strong storms with hail
potential between around 09-14Z Saturday morning.

Hotter temperatures return for Saturday and Sunday, with
highs in the 90s to possibly low 100s. Upper ridge flattens out a
bit towards Sunday, bringing more quasi-zonal flow. Expect
temperatures to cool a bit by Monday through the rest of next
week. Low level southeasterly flow will be common next week,
bringing increasing moisture into the region. Expect more active
weather potential next week, with daily chances for at least
isolated showers/storms


&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1114 AM MDT Fri Aug 7 2026

VFR conditions are expected through the TAF period. LLWS is likely
southeast of the Black Hills after 08/06z, but should not affect
the KRAP terminal.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION...Dye
AVIATION...Helgeson