Marine Weather and Tide Forecast for Hill City, SD

DISCUSSION
(This Evening Through Thursday)
Issued at 118 PM MDT Thu Jun 19 2025

Current upper air models show broad ridge over the Rockies into the northern and central plains, with troughing over the great lakes region. Surface charts depict weak low over the WY/SD border this afternoon. Temperatures currently sit in the upper 80s and 90s, with breezy southwest to southeast winds.

Upper ridge will support hot and mostly dry conditions through Saturday. A weak impulse may spark a couple shower/storms this evening, mainly across far northeastern WY into northwestern SD, however given modest capping and limited moisture have kept PoPs out of the forecast. If storms are able to fire up near the better forcing, strong to severe storms may be possible given decent CAPE and strong shear over the area today. High based rain showers could develop across the NW third tonight with the passing impulse to the north, but not enough confidence to justify adding pops. Upper ridge will continue to support capping and limit storm potential through Saturday. Hot temperatures will support heat advisory apparent T's Friday and Saturday. Dry southwesterly flow should keep heat index slightly lower than ambient temperatures, with forecasted highs to reach near 105 for parts of the western SD plains. Saturday the upper ridge slides eastward, with troughing settling into the western CONUS and Rockies. Cold frontal boundary moves through the area Saturday night, setting up cooler temperatures for Sunday, as well as unsettled weather early next week.

AVIATION
(For the 06Z TAFS Through 06Z Friday Night)
Issued At 955 PM MDT Thu Jun 19 2025

VFR conditions through the period. Isolated showers/storms are possible overnight across northeastern WY, the Black Hills, and northwestern SD.

UNR WATCHES/WARNINGS/ADVISORIES
SD...Heat Advisory from 1 PM Friday to 9 PM CDT Saturday for SDZ046- 047-049.
WY...None.