Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Missoula Montana
251 PM MDT Sat Oct 3 2015
Discussion...easterly winds are anticipated to increase this
afternoon and evening as the pressure gradient tightens. As a
result, wind advisories will continue on into the evening. After
midnight, conditions are expected to become favorable for a
downsloping east wind onto Flathead Lake. Thus, the advisory in
that area was extended until Sunday morning. These easterly winds
are causing upslope precipitation along the Continental Divide
with fairly low snow levels. Logan and Marias Pass may still be
impacted by Sunday morning with a bit of snow, with the more
significant accumulations being east of the Continental Divide.
As the trough shifts east of our area Sunday, skies will clear
from west to east. A few lingering snow showers along The
Divide should dissipate by mid morning. Despite a sunny
afternoon, high temperatures will be crisp compared to last week,
with Montana valleys in the 50s and central Idaho valleys in the
60s. Lingering cold air will then make for a chilly Sunday night,
with some Montana valleys possibly seeing the coldest temperatures
of the year. The Missoula and Bitterroot valleys in particular are
looking at temperatures potentially reaching the mid 20s. Any
lingering sensitive plants will likely need protection, and above-
ground sensitive pipes may need attention.
The first half of next week looks quiet weather-wise, with
gradually warming daytime temperatures but continued cool
overnight lows in valleys. By mid-week, highs should reach about 5
degrees above normal. Forecast models are trying to bring in some
mid-level moisture around the middle of the week, but it isn't
clear at this point if this will result in precipitation for the
region, or just increased clouds. For now, we're just mentioning
an outside chance of showers for much of the northern rockies.
Looking ahead towards next week, it appears a strong ridge of high
pressure will build into the western US. This could bring another
few days of abnormally warm temperatures with dry conditions.
Aviation...gusty northeast winds of 15-25 knots will continue
for most terminals. Ksmn will also have increased wind speeds, but
are not expected to be as strong. Wind impacts will decrease by
Sunday morning. The easterly flow will cause upslope precipitation
along the Continental Divide as snow levels drop to around 5000
feet, so mountain passes along The Divide could be obscured at
times by snow and/or low ceilings.
Montana...Wind Advisory until midnight MDT tonight Butte/Blackfoot
region...Missoula/Bitterroot valleys...Potomac/Seeley Lake
Freeze watch from late Sunday night through Monday morning
Wind Advisory until midnight MDT tonight Flathead/mission
valleys...Kootenai/Cabinet region...West Glacier region.
Winter Weather Advisory until noon MDT Sunday above 5000 feet
for the West Glacier region.