A storm system currently centered near San Francisco is set to impact Montana later this week, with showers and thunderstorms rotating around it already making their way into southwest Montana. While there's a slight chance that a few of these showers could hold together as they move north, north central Montana can expect an otherwise dry and mild day, with daytime highs reaching the 70s.
The system will drift northeast across Idaho on Tuesday. Clouds will begin to move into the area on Tuesday morning, followed by an increase in shower and thunderstorm activity throughout the day. There is a possibility of severe thunderstorms for the afternoon and evening, some of which may contain damaging wind gusts, hail, or even an isolated tornado.
As the center of low pressure moves into eastern Montana, it will strengthen, leading to widespread showers across central Montana by Wednesday morning. Just northwest of the low, a band of very heavy rain will form as moisture wraps around the low pressure center. The flow will shift out of the north-northwest throughout the day, resulting in strong upsloping on some of the central Montana mountain ranges. These areas are where 2-3 inches or more of rainfall may fall. Elsewhere, 1-2 inches of rainfall will be a good bet.
Areas highlighted in yellow have the highest likelihood of receiving over 2 inches of rain; however, these heavier precipitation amounts will largely depend on the terrain. Snow levels are expected to remain above 7,000 feet throughout the storm.
Wind will also be a significant factor, especially as the low pressure center passes by on Wednesday afternoon and evening, bringing gusts of 40-50 mph across the area. The stronger wind gusts will shift into eastern Montana overnight, with a decrease in wind across central Montana.
Showers may linger into Thursday morning, but most of the rain should taper off by the afternoon. Expect a dry and warm end to the week, with temperatures climbing back into the 70s. The weekend is looking cooler and more unsettled.