Western Dakotas Heat Wave Sets Stage for Montana Storm Gust Clusters — SevereWX

Thunderstorms are ramping up across the high terrain of eastern Montana and northeastern Wyoming, poised to push organized clusters eastward into the western Dakotas this afternoon and evening.

SPC Mesoscale Discussion 1797 highlights a volatile setup: temperatures soaring into the upper 90s to 100°F across the western Dakotas, paired with dewpoints in the upper 50s to 60s°F. Strong MLCIN is eroding under sunny skies, unlocking moderate instability and steep low-to-mid level lapse rates of 7-8°C/km. Dry sub-cloud layers sampled in recent soundings from Bismarck and Rapid City further boost the odds for potent downdrafts.

Expect one or more clusters to develop and spread east, capable of 55-70 mph wind gusts and hail up to 1.25 inches. A thunderstorm cluster in eastern North Dakota has already clocked 57 mph gusts, signaling the threat's potential.

SPC pegs watch issuance odds at 60% for this evening window (roughly 3 PM to 7 PM Moderate). Check the SPC graphic for the latest outlook.

Stay prepared: Monitor local warnings, secure outdoor items, and have a severe weather plan ready. Western Dakotas residents, treat this as a heads-up for rapid storm development.