FXUS63 KUNR 051730

AFDUNR



Area Forecast Discussion For Western SD and Northeastern WY

National Weather Service Rapid City SD

1130 AM MDT Tue May 5 2026



.KEY MESSAGES...



- Active northwest flow will persist through the week with 

  unsettled weather.



- Cooler temperatures persist through Wednesday before warming

  trend into the weekend.



&&



.UPDATE...

Issued at 954 PM MDT Mon May 4 2026



No significant forecast changes needed with this evening's update.

Things still looks quite cool and unsettled through Tuesday

evening with CAMs continuing to advertise at least isolated shower

potential, but QPF probabilities are quite low so not much of any

rainfall is expected. Some showers will fall as snow over the 

Black Hills and perhaps northeastern Wyoming, but even at the 

higher elevations of the Black Hills where temperatures will be 

coldest, less than 2 inches are expected where it does snow.

Wednesday will still lean cool (highs in the 50s), before

temperatures noticeably warm from Thursday into the weekend (60s

and low 70s).



&&



.DISCUSSION...(This Evening Through Monday)

Issued at 113 PM MDT Mon May 4 2026



Water vapor imagery shows active northwestern flow across the 

Northern Plains. Closed upper low is centered over western Ontario

with another closed low over central CA coast. The surface cold 

front pushed through the area around 11z this morning and now 

stretches from the surface low in central Ontario southwestward 

through southern NE.



Weak mid-level frontogenesis coupled with steep low-level lapse 

rates have resulted in scattered showers this afternoon, mainly 

south of I-90. Given dry boundary layer and weak forcing, expect 

minimal precipitation amounts.



Well-mixed boundary layer with 35-40 knot winds atop the boundary 

layer will support gusts up to 45-50 MPH this afternoon across 

northwestern SD. A Wind Advisory remains in effect for portions of 

the northwestern SD plains through 6 PM MDT.



Active northwest flow persists through mid-week with cooler than 

average temperatures (5-10F below normal) before warmer air filters 

back into the region with seasonable to above average (~5-10F) 

temperatures for the latter half of the week into the weekend. 

Showers and thunderstorms possible Saturday as upper shortwave 

trough drops into the Northern Plains.



&&



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

Issued At 1127 AM MDT Tue May 5 2026



Isolated showers may be possible this afternoon and evening over

the Black Hills into southwestern SD, potential for low VFR to

MVFR conditions in any showers. VFR conditions are expected

through the period at both TAF sites.





&&



.UNR WATCHES/WARNINGS/ADVISORIES...

SD...None.

WY...None.

&&



$$



UPDATE...KSmith

DISCUSSION/KEY MESSAGES...SE

AVIATION...Dye