769 FXUS65 KMSO 042007 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 207 PM MDT THU SEP 4 2014 ...Colder tonight in most valleys... ...Warmer and sunnier days Friday through the weekend... .DISCUSSION...A colder night is expected across the valleys of western Montana and parts of north central Idaho. The air mass is drying even further, which will allow more heat to escape tonight, resulting in colder valley readings. A few areas could see a hard freeze (for instance: Seeley Lake, Sula, Georgetown Lake, Deerlodge, and Butte, to name a few). Even where temperatures only fall into the mid 30s, the actual temperature below the temperature sensor and next to the ground normally becomes colder and thus frost is likely in those areas as well. Overall, high pressure is expected to build over the Northern Rockies into Saturday and then persist into Monday. This will translate into lots of sun, warmer days, light winds, and cool nights. The next threat of showers or a change of conditions is not expected until Tuesday or Wednesday of next week. Even at that, there is a lot of uncertainty in the exact pattern that may set up, so the threat of showers is relatively low. && .AVIATION...A drier air mass is setting up over the region and will translate into mostly clear skies tonight. Some shallow patchy fog is possible in the valleys of northwest Montana. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...FROST ADVISORY from 3 AM to 8 AM MDT Friday Bitterroot...East Lolo...Flathead/Glacier Park...Flathead/Mission Valleys... Kootenai...Kootenai/Cabinet Region...Lower Clark Fork Region...Missoula/Bitterroot Valleys...Salish and Kootenai Reservation...West Lolo. ID...None. && $$