Wasta, SD 57767 Weather

Key messages

- Dry, mild, and occasionally breezy for the rest of the week.

- Next organized chance of precipitation arrives Sunday night and Monday.

Update

Issued at 928 PM MDT Tue Oct 27 2026

Water vapor imagery shows shortwave trough pushing through northern WY into the forecast area with increasing upper level ascent evident in expanding area of mid and upper level clouds. Light precipitation is possible overnight through Wednesday morning as the shortwave moves through, however the dry boundary layer will preclude widespread measurable precipitation. Moist, upslope southeasterly flow will persist through the evening with patchy fog expected across portions of the western SD plains into south-central SD tonight. Otherwise, the going forecast remains on track. Warmer and generally drier through the end of the week into the weekend.

Discussion

(This Afternoon Through Monday) Issued at 1036 AM MDT Tue Oct 27 2026

Mean upper troughing over the PAC NW and western Canada will support general SW flow through the remainder week with weak impulses traversing the flow. Expect mainly dry weather weather as these systems fight very dry low levels, although a few sprinkles may be possible as each weak shortwave traverses the region. Dry air spreading into the region today, scouring out low level clouds and fog. Expect breezy winds with highs in the 50s and 60s. Weak impulse will traverse the region tonight and may support isolated rain or snow showers from northeast WY into NW SD. Mostly virga expected, but a couple showers may reach the ground. Otherwise, for the rest of the week highs will generally be in the 60s, with high temp potentials depending on the timing of the thermal ridges ahead each system. This could allow slightly warmer or cooler numbers than what the current forecast has. Upper trough will lift out the Pac NW early next week, with unsettled looking more likely coupled better chances for precip.

Aviation

(For the 12Z TAFS Through 12Z Thursday Morning) Issued At 459 AM MDT Wed Oct 28 2026

A very weak disturbance crossing the region will continue to support low chances of a few showers across northeastern Wyoming, the Black Hills, and northwestern South Dakota through about 15z/9am MDT this morning. The low-levels are quite dry west of the Black Hills, so some of what you may see on radar will likely present as virga (light rain/snow falling out of somewhat high cloud bases aloft) and not reach the ground. Cigs will remain VFR. Meanwhile, better low- level moisture will support some patchy fog across the plains well south and east of KRAP, with transient LIFR cigs/vsbys resulting in a few spots. Otherwise, we return to a mild, dry, and occasionally (modestly) breezy week. Expect clearing skies from west to east between 14-17z/8-11am MDT today with no further impacts expected though the end of the TAF period.

Watches, warnings and advisories

SD: None. WY: None.