541 

FXUS63 KUNR 051728

AFDUNR



Area Forecast Discussion For Western SD and Northeastern WY

National Weather Service Rapid City SD

1128 AM MDT Fri Jun 5 2026



.KEY MESSAGES...



- A slight chance for an afternoon shower or thunderstorm over the

  Black Hills today.



- Hot and dry Saturday.



&&



.UPDATE...

Issued at 1012 PM MDT Thu Jun 4 2026



Made minor changes to pops/weather overnight and Friday morning to 

include better timing for chances of showers and thunderstorms. 

Overall, the forecast remains on track with showers ending early 

Friday morning over the eastern portion of the forecast area and a 

slight chance for a stray shower or storm during the afternoon over 

the Black Hills. 



Temperatures on Saturday will be hot, through NBM highs may be a 

little too warm considering how green the grass is with all the 

recent rain. At the current time, will not make any adjustments but 

will continue to monitor model trends for future adjustments. 

Otherwise, the forecast remains on track with chances for showers

and storms returning again on Sunday.



&&



.DISCUSSION...(This Evening Through Thursday)

Issued at 122 PM MDT Thu Jun 4 2026



Upper level analysis has mostly zonal flow over the Northern Plains 

with a shortwave trof moving through the Rockies in Montana and 

Wyoming. A surface low is currently over the Bighorns with a trough 

extending northward into central Montana and a stationary boundary 

stretching across the South Dakota/Nebraska border into northeastern 

South Dakota. Satellite imagery is showing building cumulus clouds 

over northeastern Wyoming and southeastern Montana. Temperatures at 

18Z were mostly in the 70s with 60s in the Black Hills. 



For this afternoon and evening, convective initiation will likely 

begin over northeastern Wyoming and southeastern Montana as the 

Black Hills and South Dakota Plains remain fairly well capped. Deep 

layer shear around 50kts will support the potential for supercell 

development, with the potential for large hail. The surface

boundary near the state line will drift northward later this 

afternoon. Moisture convergence along the boundary interacting 

with large-scale ascent from the approaching shortwave, will 

combine with deep-layer shear of 35-45kt, supporting potential 

storms with a more outflow dominant storm mode.



Convection will move eastward overnight. lingering into Friday 

morning. Temperatures will warm Friday, with highs in 80s, some 

70s in the Black Hills. Shortwave ridging builds to the west, but 

diurnally driven showers over the Black Hills can't be ruled out 

during the afternoon. The shortwave ridge will move over the 

forecast area on Saturday, resulting in hot and dry conditions. 

Storm chances return Sunday as the upper level trof deepens over 

the western US and places our CWA under unsettled southwest flow.



&&



.AVIATION...(For the 18Z TAFS Through 18Z Saturday)

Issued At 1126 AM MDT Fri Jun 5 2026



VFR conditions are expected through the period. 



&&



.UNR WATCHES/WARNINGS/ADVISORIES...

SD...None.

WY...None.

&&



$$



UPDATE...MLS

DISCUSSION/KEY MESSAGES...MLS 

AVIATION...MLS