Posted: Jan 17, 2013 2:57 PM by Erin Yost - StormTracker Weather Center
Updated: Jan 17, 2013 7:32 PM
MISSOULA - Morning fog, afternoon sunshine, valley inversions and eventually poorer air quality are what we can expect over the next several days as very strong high pressure sits across the Pacific Northwest.
High pressure is sinking air which doesn't allow air to mix or (typically) even form clouds. This is the reason colder air and low clouds will settle into our valleys while the mountains see warmer temps and plenty of sunshine.
A Dense Fog Advisory has been issued for all of west central Montana (including the Flathead, Mission, Missoula and Bitterroot Valleys) from 11 p.m. Thursday until noon Friday. Much like the last couple of mornings, visibilities will be reduced to 1/4 mile or less at times.
Highs will stay in the 20s for our inverted valleys with low to mid 30s elsewhere. Overnight lows will range from the single digits to teens.
It doesn't look like any big pattern changes in the extended forecast, at least until the middle of next week.