Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Missoula Montana
249 PM MDT Thursday Oct 8 2015
Discussion...high pressure will slowly build back into western
Montana and central Idaho tonight into Friday. Under the ridge,
drier air will slowly work its way into the region. Low and mid
level cloud cover currently in place will slowly dissipate through
the night, leaving clearing skies come Friday morning. Fog and
low stratus may form once again in the valley locations due to the
clearing skies and light winds. However, this will be short-
lived, as generally sunny and warm conditions will prevail come
Friday afternoon, with many locations reaching well above normal
for this time of year.
Saturday will be another warm day initially, but during the
afternoon and evening the next weather system will begin moving in
from the northwest. Showers will spread to the southwest
Saturday evening, but the bigger impact will likely be winds. The
strong jet stream will cause surface winds to become substantial
Saturday afternoon, with breezy conditions continuing overnight.
Although mountains will be the most windy, gusts could be into the
30s for many valleys by Sunday morning. Choppy lake conditions are
a concern for those with recreation plans. Showers will taper off
Sunday afternoon, but winds will remain breezy until Monday
morning. With this system, temperatures will decrease to near or
below normal values, with 50s for valley highs on Sunday. Many
valleys will again receive around a tenth of an inch of rain.
Higher rain totals are expected in the terrain. Freezing levels
are expected to remain above Mountain Pass level, so snow will
not likely be an impact for most.
A ridge of high pressure is expected to build back into the region
early next week. One of our forecast models is currently showing a
weak disturbance moving through the top of the ridge into
northwest Montana on Monday/Tuesday, which could bring some
increased clouds and showers. However, confidence in this system
is currently fairly low. Beyond Tuesday, warmer and drier
conditions are expected.
Aviation...low and mid level clouds will continue to obscure the
higher terrain through the rest of this afternoon and early
evening. As high pressure builds back into the region, drier air
aloft should help decrease the cloud cover overnight. Fog and low
stratus will be possible in the valleys Friday morning, but will
likely be short-lived.