WESTERN MONTANA - Thunderstorms this evening are the beginning of a more active weather pattern across Montana in the week ahead.
Warm air ahead of an approaching storm system today will send temperatures into the upper 70s and low 80s. This will provide energy for thunderstorm development. Increasing moisture this afternoon will help kick off storms in the late afternoon. Storms will likely begin developing during the afternoon just to the east of Spokane, Washington and Lewiston, Idaho as the mountains there provide extra lift.
Storms will move across Idaho and into Montana during the evening hours. Most of these storms will be on the weak side, but a few will produce gusty winds and hail in addition to lightning and localized heavy rain. Forecast models are showing the most energy for these storm to tap into will be north of Butte and west of the Continental Divide. This area is where the strongest storms will form. The greatest impact will be between 5 pm and 10 pm today.
Those overnight hours leading into Friday morning are the best chance we have for rainfall in the near term. Northwest Montana, especially around Glacier National Park, has a good chance to pick up around a quarter of an inch by Saturday morning.
Cool air arrives Friday morning which will limit highs to the mid 60s through the weekend. Higher elevations will see highs only in the 50s on Saturday with scattered showers expected into next week.