FXUS65 KMSO 270822 AFDMSO

Area Forecast Discussion National Weather Service Missoula MT 222 AM MDT Sat Jul 27 2024

DISCUSSION
A broad trough of low pressure off the coast of British Columbia will promote a west to southwest flow over the Northern Rockies through the weekend. This will allow for seasonable temperatures and dry conditions to persist. One area where afternoon convection is possible this weekend, will be Lemhi County and southwestern Montana, with a 25% probability for thunderstorms each day. Afternoon westerly winds will also be a common occurrence during this time, with gusts around 15-25 mph for many locations across western Montana and north-central Idaho.

Due to west to southwest flow, smoke from local and regional wildfires will degrade visibility and air quality at times throughout the Northern Rockies this weekend.

The aforementioned trough of low pressure will shift east early this coming week, that will open door for a shortwave trough to traverse the Northern Rockies. Ensemble forecast models are in fairly good agreement for scattered showers and thunderstorms across a majority of the region, that will be capable of gusty erratic winds and occasional lightning. Nothing at this time, points to widespread severe winds or large hail.

Long range ensemble members are in very good agreement with the resurgence of the Four Corners ridge of high pressure by the end of the week and going into next weekend. The National Blend of Models currently has a 50% probability for the valleys in western Montana nearing the century mark, and a 70-90% probability for north-central Idaho.
Show more