Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Missoula Montana
301 PM MDT Friday Oct 24 2014
Discussion...cloudy skies and light rain showers over the region
will slowly move north through the night as high pressure and
warmer air develop into the region. Saturday will be a spectacular
day for this late in October, a great day for outdoor activities.
It will be very warm with many areas reaching the mid 60s, even
higher in some areas. Enjoy it because another strong weather
disturbance will quickly move into the region late Saturday
through Monday. A couple of big impacts from this system.
1. Strong winds in mountains and in Grangeville and the Camas
Tightening pressure gradients Sunday in conjunction with a strong
south to north jet will be the ingredients for windy conditions.
First, downsloping conditions will produce 20-30 mph winds with
gusts in the 40s in Grangeville and the Camas Prairie. Second,
open areas and ridgetops of central Idaho and the Bitterroot
Mountains may experience gusts to 60 mph.
2. Mountain snow Sunday and Sunday night. Mountain passes may
receive a few inches of accumulating snows.
Plenty of moisture and westerly winds will produce favorable
conditions for mountain rain and snow (orographic lift). Snow
levels will lower during the day Sunday to around 4000-4500 feet
through Monday. Mountainous areas above 4500 feet could receive
2-4 inches (more at the highest elevations) of snow during this
period. People with outdoor activities or hunters take precaution
as confidence is increasing for accumulating snows.
Unsettled weather looks to continue for at least the first part of
next week. Showers will likely continue into early Monday,
especially over the mountains. Snow levels will bottom out Monday
morning, with a few Bitterroot valley flakes not out of the
question. Showers should taper off by the afternoon with some
partial clearing as the trough exits.
Another wet weather disturbance takes aim at the Pacific northwest around
Tuesday. Gusty southwest winds will develop once again, and snow
levels look to rise as warmer air moves in. Central Idaho will
have the best chance of heavier rain, with lesser chances further
East. Pass-level snow is not expected as snow levels look to rise
Drier weather is possible for the latter half of the week with
some ridging building in. Models are trending towards a more
amplified pattern overall, which would result in a longer break
in the active weather lasting through around Halloween.
Aviation...a warm front is moving south to north across the
northern rockies. Winds will be light with this front. The
expected impacts at area terminals are lower ceilings with light
rain and mountain obscurations. Kbtm will see shower chances
diminish this afternoon, with kmso and kgpi being affected this
afternoon and evening. Clearing skies from south to north will
occur tonight into tomorrow.
Idaho...Wind Advisory from 1 PM Saturday to 5 am PDT Sunday