FXUS63 KUNR 042341

AFDUNR



Area Forecast Discussion For Western SD and Northeastern WY

National Weather Service Rapid City SD

541 PM MDT Mon May 4 2026



.KEY MESSAGES...



- Wind Advisory remains in effect for northwestern South Dakota

  with gusts of 40 to 50 MPH.



- Active northwest flow through will persist through the week with

  unsettled weather.



- Cooler temperatures persist through Wednesday before warming

  trend into the weekend.



&&



.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 00Z TAFS Through 00Z Tuesday Evening)

Issued At 541 PM MDT Mon May 4 2026



Gusty northwest winds are expected to decrease around

02-03z/8-9pm this evening, with a few light showers still running

around as well for a few more hours. Best chance is over the 

Black Hills and southwestern South Dakota plains with MVFR cigs

possible, with just a PROB30 chance into KRAP and KGCC with 

continued VFR cigs/vsbys likely there. Precip potential sinks 

solidly south of KRAP and KGCC overnight. Diurnal wind increase 

will be much more modest Tuesday, with the main question how much 

shower activity may redevelop during the afternoon. CAMs are 50/50

on as much as scattered coverage vs. almost nothing, and 

confidence in direct impacts at any given terminal is certainly 

low. Will hold off on any PROB30s for now, but will continue to 

evaluate this potential with future updates. Any showers 

manifesting over the Black Hills could be snow, which would pose 

some intermittent MVFR to IFR cig/vsby concerns especially 

directly underneath any activity.



&&



.UNR WATCHES/WARNINGS/ADVISORIES...

SD...Wind Advisory until 6 PM MDT this evening for SDZ001-002-012-013-

     073-078.

WY...None.



&&



$$



DISCUSSION/KEY MESSAGES...SE

AVIATION...KSmith