436
FXUS65 KMSO 190919
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
319 AM MDT Thu Sep 19 2024

.DISCUSSION...A mostly dry west to northwest flow will develop
over the Northern Rockies for the rest of the week and weekend. A
weak ripple in the flow Friday will aide in an increase in
westerly winds during the afternoon, with a 60-70% probability for
gusts reaching 20 mph throughout western Montana and north-
central Idaho. Those probabilities lower to 30-40% for widespread
gusts of 25 mph. Those planing to recreate on Flathead Lake Friday
afternoon between 3PM and 9PM should keep that in mind.

The increase in wind Friday will also help with drying of the
atmosphere and with partial clearing skies during the overnight
hours, there will be increasing probabilities for areas of frost
both Saturday and Sunday mornings. Frost probabilities range from
30 to 50 percent for the more populated valleys of western
Montana. As for north-central Idaho, those outside of the higher
elevated valleys (Orofino, Kamiah, & Grangeville) the probability
for frost is less than 10%. From Weippe to Pierce, the frost
probability jumps up to 60 to 70 percent.

Around 50 percent of the ensemble clusters depict a weak
shortwave trough by Monday, that will bring a general 20 to 30
percent chance for showers. Temperatures will be seasonable to
start the week, then warming back to the 70s and 80s with dry
conditions by mid- week.


&&

.AVIATION... Patchy fog is possible in the valleys this morning.
Otherwise, VFR conditions will be common both today and Friday with
afternoon gusts of 15-20 kts at terminal sites.


&&

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

$$