575
FXUS63 KUNR 281636
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1036 AM MDT Wed Oct 28 2026

.KEY MESSAGES...

-Mild and dry through the rest of the week

-Unsettled and cooler to start next week with a good chance of
 rain Sunday night into Monday, with high some high elevation snow
 possible as well

&&

.DISCUSSION...(This Afternoon Through Tuesday)
Issued at 1035 AM MDT Wed Oct 28 2026

Mean upper troughing over the PAC NW and western Canada will
support general SW flow through the remainder week with weak/dry
impulses traversing the flow. Departing impulse giving way to
clear skies today as winds shifts NW behind the sfc reflection.
Expect highs in the 50s and 60s. Otherwise, for the rest of the
week highs will generally be in the 60s, although things will cool
down Friday some behind a weak cool front, with highs generally
in the 50s that day. Mild this weekend as WAA and height rises
spread NE ahead of the digging western CONUS upper trough. There
is a low chance for a few showers Friday night toward central SD
as a disturbance skirts the region and forces pos theta-e adv.
Western CONUS upper trough will lift out the Pac NW early next
week, with broad lift spreading into the region starting Sunday
night. The best chance for precip will be Monday when the main
trough passes over the region. Very warm system for early Nov,
with mainly rain expected. However, enough cold air may entrain
into the back of the system Monday to allow for some higher
elevation snow across northeast WY and the Black Hills. This could
some support some light snow accums chances there, esp in the
northern Black Hills.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Thursday Morning)
Issued At 459 AM MDT Wed Oct 28 2026

A very weak disturbance crossing the region will continue to
support low chances of a few showers across northeastern
Wyoming, the Black Hills, and northwestern South Dakota through
about 15z/9am MDT this morning. The low-levels are quite dry west
of the Black Hills, so some of what you may see on radar will
likely present as virga (light rain/snow falling out of somewhat
high cloud bases aloft) and not reach the ground. Cigs will remain
VFR. Meanwhile, better low- level moisture will support some
patchy fog across the plains well south and east of KRAP, with
transient LIFR cigs/vsbys resulting in a few spots. Otherwise, we
return to a mild, dry, and occasionally (modestly) breezy week.
Expect clearing skies from west to east between 14-17z/8-11am MDT
today with no further impacts expected though the end of the TAF
period.

&&

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

$$

DISCUSSION...JC
AVIATION...KSmith