MISSOULA — A soaking early-week storm system will bring rounds of thunderstorms, heavy rain, and possible flooding concerns to parts of western Montana before a gradual return to warmer and drier weather. The pattern remains active, however, with another potentially significant system looming next weekend.
SUNDAY NIGHT
Showers and thunderstorms will continue across western Montana through the evening, with a few storms capable of producing intense rainfall, small hail, and gusty winds. Storms may briefly diminish late tonight, but another round of thunderstorms is expected to redevelop around midnight and spread into southwest and west-central Montana toward daybreak Monday. Localized heavy rainfall could create problems in flood-prone areas and recent burn scars.
MONDAY
Widespread precipitation will spread across the region, becoming especially heavy across northwestern Montana and areas near the Continental Divide. Many locations have an 80 to 100 percent chance of receiving at least one-half inch of rainfall, while portions of northwest Montana could pick up 1 to 3 inches, with isolated higher amounts possible. Flooding of poor-drainage areas, rapid rises on streams and creeks, and debris on roads will be concerns through the day and night.
MONDAY NIGHT
Steady rain continues across much of western Montana, with the heaviest totals focused over northwest Montana and the higher terrain along the Divide. Flooding concerns remain in effect where the heaviest rainfall develops. Travel may be impacted by periods of heavy rain and ponding of water on roadways.
TUESDAY
The storm system begins pulling east, but showers will linger, especially across northwest Montana. Rainfall intensity will decrease compared to Monday, though damp and cool conditions will persist. Elsewhere, gradual improvement will begin as precipitation becomes more scattered.
WEDNESDAY
A drying trend develops across western Montana. Lingering moisture near the ground may lead to areas of morning fog and low clouds in valleys before sunshine gradually returns. Temperatures will begin recovering toward seasonal averages.
THURSDAY
Milder and generally drier conditions continue. Morning valley fog remains possible in some locations, but afternoon weather should be pleasant with temperatures climbing back toward the 70s and lower 80s in lower elevations.
FRIDAY
Late-summer weather remains in place with warmer afternoons, light winds, and mainly dry conditions. Outdoor plans should enjoy the best stretch of weather of the week.
SATURDAY
Forecast confidence decreases, but attention turns to another potentially impactful weather system approaching the Northern Rockies. Current ensemble guidance shows roughly a 70 percent chance of another round of unsettled weather arriving during the weekend. Cooler temperatures, showers, and mountain snow at the highest elevations are all possible, with a 20 to 30 percent chance of snow above 7,000 feet along the Continental Divide.
SUNDAY
Unsettled weather may continue into the latter part of the weekend depending on the track and strength of the next storm system. Residents should monitor forecast updates as confidence improves regarding rainfall amounts, temperatures, and any early-season mountain snow potential.
