Area Forecast Discussion
Issued by NWS Missoula, MT
FXUS65 KMSO 242024
Area Forecast Discussion
National Weather Service Missoula MT
224 PM MDT Fri Mar 24 2017
.DISCUSSION...A weather system and associated cold front will
sweep across north central Idaho early this evening and western
Montana overnight. Initially, the snow level is above most
mountain passes, but will lower overnight with mainly Lolo, Lost
Trail, William`s Summit, and possibly Homestake seeing some snow.
The impact should be a short period of slush or wet snow on the
roadway later tonight and early Saturday morning. Otherwise, rain
showers should be on the light to moderate side with little or no
A relatively cool and breezy period is expected Saturday as a
moist and unstable atmosphere covers the northern Rockies.
Sunday brings weak high pressure and a dry period with seasonal
high temperatures into the 50s. The ridge aloft could allow for
some patchy fog during the early morning hours, but heating after
sunrise would quickly mix out fog that does form.
Sunday night into Monday morning, another wet system will move
over the region. The main energy with this trough will be to the
south, so precipitation rates and accumulation will again be on
the light side. However, Clearwater and Idaho county could see
another 0.25 to 0.50 inches of moisture over 24 hours, so
saturated soils could again become more prone to isolated mud and
rockslides. Scattered showers, mainly in the terrain, linger on
Tuesday and Wednesday in westerly flow.
A more robust system could bring heavier rain amounts on
Wednesday night. Models advertise a short burst of Pacific
moisture before a shortwave trough moves through Thursday. But
these type of systems have trended south in recent weeks, so the
confidence in precipitation amounts is low at this time.
.AVIATION...The Northern Rockies will see thickening clouds and
lowering ceilings into the evening as the next weather system
approaches. North central Idaho will see light to moderate rain
showers first, into this evening. Western Montana aviation sites
KMSO and KGPI should see showers this evening and overnight. The
frontal/weather system will not impact KBTM with showers until
around or after midnight. The main impacts of the showers should
be lowering of ceilings and visibility in the more moderate
precipitation showers and increasing terrain obscurations.
Southwesterly breezes of 20-30 kts ahead of the showers can be
expected for KBTM into this evening.