FXUS63 KUNR 012327

AFDUNR



Area Forecast Discussion For Western SD and Northeastern WY

National Weather Service Rapid City SD

427 PM MST Sun Nov 1 2026



.KEY MESSAGES...



- Widespread rain tonight through early Tuesday, with the heaviest

  totals over central South Dakota and northern Black Hills.



- Strong northwest winds Monday and Monday night. Gusts of 45-55

  mph expected, with localized gusts to 60 mph possible.

 

- Rain changing to snow over the higher northern Black Hills

  Monday evening, with light accumulations.



- Drier weather returns later Tuesday and remains for the rest of

  the work week.



&&



.DISCUSSION...(This Evening Through Sunday)

Issued at 234 PM MST Sun Nov 1 2026



Satellite/WV imagery shows a deep upper trough crossing the western 

CONUS, centered across the Great Basin, with very moist 

southwesterly flow increasing across the northern High Plains. 

Surface obs show low pressure strengthening across eastern WY into 

the CO Front Range. Southerly winds extending from TX to the Dakotas 

are pushing in plenty of moisture in the low levels. Still looks 

like the entire CWA will see precip from early this evening to early 

Tue morning as this large system crosses the north central CONUS. 

The three aspects of this storm we are resolving are QPF amounts, 

snow accumulation, and wind gusts. There is very good model 

agreement with widespread totals of 0.50" or more across the entire 

CWA. Models over the last 24 hours have settled on central SD 

receiving the most QPF, which could reach over an inch and a half or 

even 2 inches. Also, the northern Black Hills could see upslope-

enhanced QPF exceeding two inches (some models suggest near 3 

inches). Most other locations have a good chance of over an inch. 

This is an impressive system for early November bringing in PWATs 

over an inch...and approaching 1-1.5 inches over the eastern half of 

SD, which would be considered decently moist for the summer months. 

Given how dry early November is, that is 2-3 times higher than 

average. Upcoming soundings will show how well that verifies. Either 

way, the moisture is there for these high QPFs. Colder air will move 

in on the backside of the low during the day tomorrow. While the 

system will remain too warm for widespread accumulating snow, the 

higher elevations of the northern Black Hills should see minor 

accumulations (~2") after rain switches to snow Monday evening. 

Temps will be marginally cold enough in the evening for snow across 

the NE WY plains, but overall accumulation will be greatly 

limited by precip ending before sufficiently cold air arrives. 

However, minor accumulations along higher ridges can't be ruled 

out. Winds will increase behind the system as well, as the low 

closes up Mon afternoon with gusts of 45-55 mph or more expected 

across the NE WY plains and the western SD plains. The question 

remains just how strong the gusts will end up being. CAMs have 

been showing well above 50kt wind gusts across western SD. 

Interestingly, the 18z HRRR has dropped max gusts to 45-55mph, 

which is what prior shifts have been settling on. The exception is

+50kt winds just east of the Black Hills into Fall River County. 

This lines up nicely with ensemble guidance. A High Wind Watch has

been issued for most of the western SD plains given the potential

for warning-level gusts, although portions of the watch area may 

ultimately warrant a Wind Advisory instead. Precip ends Tuesday 

morning, with drier and cooler (but near average) temps through 

mid week. Winds will be gusty early Tuesday but taper off through 

the day. Quiet weather is expected through the second half of the 

week.



&&



.AVIATION...(For the 00Z TAFS Through 00Z Monday Evening)

Issued At 424 PM MST Sun Nov 1 2026



Widespread MVFR/IFR with local LIFR conditions will continue 

through the forecast period due to low clouds/fog/precipitation. 

Rain will pass through the area from southwest to northeast, 

especially after 02/06z. Some snow will mix with the rain over 

northeastern WY/higher Black Hills after 02/12z. Strong gusty 

northwest winds will develop Monday (especially after 02/18z) 

with gusts from 40-55kts possible on the open plains, particularly

just east of the Black hills.



&&



.UNR WATCHES/WARNINGS/ADVISORIES...

SD...High Wind Watch from Monday morning through late Monday night 

     for SDZ001-002-012>014-025-026-030>032-041>043-072>075-077-

     078.

WY...None.

&&



$$



DISCUSSION...13

AVIATION...Helgeson