815
FXUS65 KMSO 021000
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
400 AM MDT Thu May 2 2024

.DISCUSSION...The Northern Rockies will be under northerly flow
aloft today keeping cool temperatures and lingering scattered
showers. The exiting low pressure system continues to cause
upslope precipitation along the Continental Divide around Glacier
National Park this morning, so a winter weather highlights remain
in effect from snow impacts.

A ridge of high pressure will slide over the Northern Rockies
Friday into Saturday causing a warming and drying trend.
Temperatures should be around 5 degrees above seasonal averages by
Saturday afternoon. This ridge will be short lived as another
significant low pressure system settles back over the western
United States by Sunday through much of next week. All models are
showing this broad trough over the region once again causing
temperatures to drop to around 10 degrees below average with
widespread shower activity throughout the week. The two periods
that the models are showing the best potential for impacts is
Sunday night into Monday then Tuesday night into Wednesday. The
Sunday night event will be widespread precipitation with snow
impacting the higher terrain of north central Idaho into southwest
Montana. Lolo Pass, Georgetown Lake and Lost Trail pass have a
20-40% chance of receiving over 2 inches of snow by Noon MDT on
Monday. Then Tuesday night another round of upslope precipitation
will impact the Continental Divide, where Marias Pass has a 50%
chance of receiving over 2 inches of snow by Noon MDT on
Wednesday.

All the models are trending towards some form of a ridge of high
pressure moving over the region by next weekend.



&&

.AVIATION...An exiting low pressure system will keep northerly
upper level flow over the Northern Rockies today. This flow will
cause lingering showers with the most prevalent being across
northwest Montana near Glacier National Park. Snow levels will
remain quite low for this time of year, so showers during the
morning hours will be primarily producing snow. These snow showers
will cause low visibility for periods of time.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until 9 AM MDT this morning for West
     Glacier Region.

ID...None.
&&

$$