Discussion
Cold front brings cooler temperatures alongside gusty westerly winds, dry air, and elevated fire weather this afternoon.
Ridge of high pressure rebuilds early this upcoming week with a warming trend.
Thunderstorms expand northward Tuesday and Wednesday afternoons.
A few lingering showers and thunderstorms are expected this afternoon across northwest and southwest Montana, otherwise a cold front will bring a much drier airmass to the region. Gusty afternoon winds will lead to elevate fire weather conditions, particularly in southwest Montana. Skies clear this evening with gusty winds diminishing around sunset.
High pressure ridging builds back in Monday lasting through Wednesday with a gradual warming trend as high temperatures reach 10 degrees above normal by Tuesday and Wednesday. After a few morning showers on Tuesday, thunderstorm chances may expand northward to about the I-90 corridor in western Montana. Much will depend on if morning cloud cover lingers into the afternoon and limits instability and thus thunderstorm coverage. Monsoon moisture spreads over most of the Northern Rockies on Wednesday (potentially Thursday as well), expanding areal coverage of shower/thunderstorm chances. This activity will likely be a mix of dry and wet thunderstorms, thus new fire starts will be a concern.
Nearly all ensemble guidance supports a trough into the Pacific Northwest Friday into Saturday knocking down the ridge. This pattern supports increased afternoon winds and a slight cool down in daytime temperatures, thus fire weather concerns become elevated once again.