Marine Weather and Tide Forecast for Bigfork, MT

FXUS65 KMSO 141825 AFDMSO

Area Forecast Discussion National Weather Service Missoula MT 1225 PM MDT Fri Aug 14 2026

DISCUSSION

KEY MESSAGES:

- Rounds of showers and thunderstorms with locally heavy rain, the potential for flash flooding, and gusty winds (mainly western Montana) through early this evening.

- Warming, overall drying through the weekend with afternoon chances for showers and thunderstorms.

Heavy rainfall and isolated flash flooding remain the primary operational concerns today. Ongoing morning showers and embedded thunderstorms across southwest and west-central Montana have already produced rain rates between 0.25 and 0.50 inches per hour.
As atmospheric instability builds through this afternoon, slow- moving or training thunderstorms will redevelop across north- central Idaho and primarily western Montana. With above-normal precipitable water values and training storm potential, localized flash flooding and subsequent debris flow activity remains a distinct hazard especially in and downstream of burn scars, steep terrain, and poor-drainage urban locations. Activity will peak through late afternoon before diminishing around 7:00 PM MDT.
Downburst outflow winds reaching up to 40-45 mph and small hail will accompany the stronger cells.

An upper-level ridge begins rebuilding over the western US this weekend, initiating a gradual warming and overall drying trend.
However, persistent southwesterly flow aloft will continually transport monsoonal moisture out of the Great Basin and into the region, maintaining daily chances for scattered afternoon showers and thunderstorms through early next week.

Ensemble guidance has indicated a ridge-flatting trough passage out of Canada in the Tuesday to Wednesday time frame, which could promote more widespread shower and thunderstorm chances independent of the diurnal thunderstorm regime. This weather feature will also likely promote an increase in surface westerly wind speeds.

Regional wildfire smoke will begin returning aloft in the coming days, but surface smoke concentrations are expected to remain light at this time.

High amounts of low-level moisture from today's rainfall combined with overnight decoupling and clearing skies will favor fog and low stratus formation in mountain valleys through the overnight period into Saturday morning. Good to excellent overnight relative humidities are expected helping to curb fire activity overnight and shortening burn windows. Daily thunderstorm activity will introduce concerns for new lightning starts over the coming days.
Show more