553
FXUS63 KUNR 062341
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
541 PM MDT Mon Oct 6 2025

.KEY MESSAGES...

- Cold tonight with areas of frost.

- Warming trend the rest of the week with mostly dry conditions.

&&

.DISCUSSION...(This Evening Through Monday)
Issued at 215 PM MDT Mon Oct 6 2025

Current upper air models show upper trough that has affected us
the last couple of days shifting eastward today with northwest
flow over the FA as upper ridge builds over the PAC NW. Surface
analysis shows high pressure shifting over the region. Winds are
currently light out of the south, with temperatures in the low 40s
to high 50s.

Surface high will allow for strong radiational cooling tonight.
Light winds and mostly clear skies will likely bring areas of
frost Tuesday morning. Frost warning continues over the
northeastern Wyoming plains, but have added some areas of the
western SD plains into a frost advisory, where lows dipping into
the 32 to 36 degree range will be possible Tuesday morning. Upper
ridge will shift over the Rockies on Tuesday and into the
northern/central plains by mid-week, as upper trough begins moves
over the PAC NW. This will usher in a warming trend along with dry
conditions at least through the work week.

Next notable disturbance looks to affect the area this weekend.
Upper ridge axis shifts east of the FA on Friday, setting up
southwest flow as the upper trough deepens over the western CONUS.
Models do diverge on timing and strength this far out, but we do
see a wave out ahead of the main trough could spark some
precipitation over the weekend as well as a shift back to cooler
temperatures.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Tuesday Evening)
Issued At 536 PM MDT Mon Oct 6 2025

Isolated showers may persist across NW SD this evening. MVFR/low
VFR CIGS are also possible...down to the Black Hills and northeast
WY. Clouds will scatter out overnight. The exception will be
over portions of the NE WY plains, where IFR CIGS/fog are
possible late tonight through Tuesday morning.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Frost Advisory from midnight tonight to 8 AM MDT Tuesday for
     SDZ001-002-030-031-041-042-075-076-078.
WY...Freeze Warning from midnight tonight to 8 AM MDT Tuesday for
     WYZ054>056-058>060.
&&

$$

DISCUSSION/KEY MESSAGES...Dye
AVIATION...13