Marine Weather and Tide Forecast for Finley Point, MT

FXUS65 KMSO 170721 AFDMSO

Area Forecast Discussion National Weather Service Missoula MT 121 AM MDT Thu Jul 17 2025

DISCUSSION

KEY MESSAGES:

- Breezy, warm and dry days are expected through the weekend.

- There's a 75 percent probability that a cool, wet and breezy weather system could impact northwest Montana on Monday.

A west to southwest flow pattern will promote warm, dry and breezy conditions today and through the weekend. The windier locations will be along and south of I-90 in western Montana, including Lemhi County. Southwest Montana and Lemhi County will have a 60 to 70 percent probability for gusts in excess of 25 mph through this evening. Also this evening, a weak shortwave will bring a few thunderstorms to Glacier National Park in the afternoon and evening.

Friday, will be the warmest day this week and the weekend, as highs will reach the 90s across western Montana, and lower 100s in the lower valleys of north-central Idaho. A wave may initiate a few thunderstorms across southwest Montana in the afternoon.
Strong wind gusts, heavy rainfall, small hail and lightning would be the main threats, generally affecting Silver Bow County southwards.

A weak cool and dry front will move through Friday night across the region. Highs Saturday will be 5 to 8 degrees cooler than Friday. But it will kick up the westerlies by the afternoon...generally up to 25 mph in the western Montana valleys, but closer to 30 mph from Lemhi County to Butte. This could make lakes in those regions, like Georgetown Lake, kind of choppy and hazardous for small craft.

By Sunday, an anomalously deep trough will be over the Pacific Northwest. This will cause temperatures to be a few degrees cooler, but keep it breezy.

On Monday, ensemble guidance depicts a cutoff low developing over Washington and Oregon State. This setup is eerily similar to the storm that we just encountered on Monday and Tuesday. There could be a cold front passage from Canada, and it could bring wet conditions across northwest Montana. The latest NBM depicts 50 to 60 percent probability for wetting rains (>0.10) for locations along and north of the Highway 2 corridor in northwest Montana, and 20 to 30 percent for the rest of western Montana and north- central Idaho. Stay Tuned.
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