Marine Weather and Tide Forecast for Hill City, SD

UPDATE
Issued at 1033 PM MDT Sun May 3 2026

No major changes with this evening's forecast update. Slightly expanded coverage of low PoPs for Monday to account for light shower potential over the course of the day. Only minor tweaks made to NBM winds/wind gusts, which continue to support the low- end WIND ADVISORY already issued across the northwestern South Dakota plains. A few other locations across the CWA could briefly gust to 45 MPH along and immediately behind the front, but the advisory area remains favored for 45-50 MPH peak gusts with the primary impact being difficult driving for some high-profile vehicles. Cooler high temperatures compared to today will range from the low 50s to low 60s Monday.

DISCUSSION
(This Evening Through Sunday)
Issued at 1203 PM MDT Sun May 3 2026

17z surface analysis had weak trough from the Big Horns into the NE panhandle. Trough reflection of compact shortwave over the Big Horns per water vapour loop. 0.5km visible satellite matinee depicted agitated CU/TCU field associated with these features.
Few lightning strikes near the Big Horns with slowly increasing radar returns over the Black Hills. ~250J/kg SBCAPE out there, forecast to peak around 500J/kg per SPC HRRR. Result will be scattered shra/isolated TS through early this evening over the southwest half of the CWA Enough 0-6km bulk shear to help a storm if buoyancy were higher, but wouldn't be surprised to see a storm put out a 30-40kt wind gust given the 18z KUNR sounding.

After the precipitation ends early this evening, next upstream shortwave trough careens southward into the northern Plains late tonight/Monday morning pushing a cold front through the CWA
Decent pressure rises behind front with forecast soundings depicting well-mixed boundary layer late Monday morning into the afternoon hours. Result will be gusty northwest winds at times, especially from K2WX-KRCA where NBM probability of >45mph wind gusts is 40-70%. Have hoisted a Wind Advisory to account. Band of 800-600mb frontogenesis will support scattered showers potentially enhancing downward momentum transfer. Temperatures will be cooler/near guidance.

Mean northwest flow aloft continues for Tuesday through next weekend with a parade of shortwaves/surface fronts. Result will be isolated/scattered showers at times. Temperatures will be 5-10F below normal Tuesday/Wednesday, but then rise to 5-10F above normal for the weekend. Confidence is fairly high until next weekend when typical ensemble guidance spreads come into play.

AVIATION
(For the 12Z TAFS Through 12Z Tuesday Morning)
Issued At 513 AM MDT Mon May 4 2026

VFR conditions are expected tonight. A cold front crossing the area at this time will bring gusty winds today. The strongest winds will be during the day across NW SD with gusts up to 45kt.
Light showers (and perhaps MVFR CIGS) are also expected today especially toward the late the afternoon. If the rain showers linger across the Black Hills late enough, it could change to snow, resulting in IFR conditions. VFR conditions will return tonight.

UNR WATCHES/WARNINGS/ADVISORIES
SD...Wind Advisory from 9 AM this morning to 6 PM MDT this evening for SDZ001-002-012-013-073-078.
WY...None.