936
FXUS65 KMSO 221842
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
1242 PM MDT Sun Sep 22 2024

.DISCUSSION...A ridge of high pressure will build over the
Northern Rockies to start the week, allowing for warm and dry
conditions to prevail. Afternoon temperatures will be running
10-15 degrees above normal, with upper 70s/low 80s in western
Montana and upper 80s in north-central Idaho. The ridge axis will
shift east Wednesday as a shortwave trough approaches from the
west. Temperatures will remain well above normal, but increasing
west-southwest winds will occur, along with isolated showers and
thunderstorms in the evening. Currently, there is a 50-60%
probability for gusts exceeding 20 mph across the Northern
Rockies. Gusts exceeding 30 mph will be possible with any
convection, with northwest Montana having the highest probability
at around 40%.

A west-southwest flow will remain the predominate weather feature
of the region through the rest of the week, until Friday when a
Pacific cold front arrives with a strong jet stream sliding south
out of British Columbia. Scattered showers, along with another
breezy day will be the result. As it stands now, Friday is
expected to be the windier day of the week, with a 40-50%
probability for widespread 25+ mph gusts across western Montana.
North-central Idaho will see much lighter winds during this
period.

25 percent of ensemble cluster models are showing a change to a
cool and wet pattern arriving by the end of next weekend or early
next week.



&&

.AVIATION...VFR conditions continue today under a westerly flow.
A weak disturbance along the Canadian border has brought an
increase in mid-level clouds across northwest Montana, that will
eventually progress south and east across the Northern Rockies
into the evening.





&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$