Scientific Forecaster Discussion
fxus65 kmso 240915
Area forecast discussion
National Weather Service Missoula Montana
315 am MDT sun Sep 24 2017
Discussion...valley temperatures are near or below freezing in
many areas this morning, so the frost advisories and freeze
warnings remain in effect this morning.
Ridging will dominate the weather across the
northern rockies this week. A weak disturbance moving through the
ridge will cause some showers, mainly in the mountains Monday
evening. Temperatures will generally stay below average until
Wednesday. Friday is expected to be the warmest day of the week
with temperatures in the mid and upper 70s.
Aviation... a 1024 millibar high sits over western Montana this
morning and has resulted in cold temperatures with areas of fog in
the valleys. There will be a chance for fog at all the terminals
through 24/1700z, though confidence is low due to atmospheric
moisture being stolen by frost development. Expect mainly VFR
conditions for the remainder of today. Winds will generally be
less than 10 knots Sunday most areas between 24/2100z and
25/0300z, though as you head further south into Lemhi County
northerly surface winds between 10 and 15 knots are possible
thanks to enhanced wind gradient there. High pressure remains
through Monday while a weak disturbance will track into the region
from British Columbia to bring mid to high clouds and maybe a few
light showers in the higher terrain.
Montana...freeze warning until 9 am MDT Sunday Lower Clark Fork region...
Idaho...frost advisory until 8 am PDT Sunday Orofino/Grangeville region.
Freeze warning until 9 am MDT Sunday eastern Lemhi County.