769
FXUS65 KMSO 171008
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
408 AM MDT Tue Sep 17 2024

.DISCUSSION...Last evening showers and thunderstorms occurred
across Idaho County and portions of southwest Montana. The highest
observed, one hour total was 0.56" from the Moose Creek RAWS
located across the southwestern tip of the Wye Wildfire. One hour
radar estimated rainfall of around 0.60" occurred over the
Elkhorn Ridge fire, located well south of Red River Hot Spring.

Some clearing is expected from eastern Clearwater County, Idaho
north and east into northwest Montana this afternoon. This warming
combined with elevated moisture will bring more scattered showers
and thunderstorms capable of heavy rain from mid-afternoon through
late this evening. High resolution models depict the potential
for 0.50" to 0.75" an hour rates with the heaviest cores. Two
known areas that could be susceptible to flash flooding would be
the River Road East Fire burn area southeast of Plains(15% chance)
and also the upper portions of the Going-To-The-Sun road(30%
chance of occurrence). Of course there could be the potential for
mudslide issues near the current wildfire burn scars in these
areas.

The main upper level low will track into Wyoming tonight, then
east and north into eastern Montana on Wednesday. The heaviest
wrap-around light to moderate showers will mainly be concentrated
along and east of the Divide. Despite this, western Montana will
continue to experience persistent showers through Wednesday
morning, tapering off west to east into the afternoon hours.

Some clearing is expected Wednesday night with high valley
locations cooling down into the 30s, and upper 20s in the Dixie,
Idaho area. Patchy fog Thursday morning will give way to a
gorgeous day across the Northern Rockies with temperatures warming
into the 60s and 70s. Breezy westerly winds 10 to 20 mph will
develop in the afternoon and evening.

Ensemble guidance continue to trend away from the colder system
for over the weekend. Looking upstream, the polar jet is quite
strong and active, bringing wet systems into southeastern Alaska.
Our area may just get clipped by a weather system on Sunday, then
there is a chance for a warm-up thereafter with southwest flow.



&&

.AVIATION...Shower and thunderstorm activity will increase in
coverage by 17/2100Z(mid-afternoon) and continue through 18/0500Z
(10 pm MDT this evening). Locally heavy rain, lower visibility,
lightning and gusty winds to 30 knots are possible, especially
from Clearwater County, Idaho to areas north and east into
northwest Montana. A departing low pressure area will keep
persistent showers going through Wednesday.


&&

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

$$