217
FXUS65 KMSO 190719
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
119 AM MDT Sun May 19 2024

.DISCUSSION...Precipitation has begun to increase across north
central Idaho and western Montana very early this morning.
Dewpoint spreads are still significant enough in portions of
western Montana to keep rainfall from hitting the ground just yet,
but light rain has been reported in central Idaho. As the
atmosphere moistens and destabilizes through this afternoon,
the probability for widespread thundershowers will increase.

As the trough moves further south on Monday, central Idaho and
western Montana will have continued below-average high
temperatures and another round of showers and isolated
thunderstorms by Monday afternoon. During this period, snow levels
are expected to drop to around 5,000 feet, with light
accumulations mainly occurring above around 6,000 feet.

Model clusters and ensemble mean guidance show good agreement for
the Northern Rockies to be between weather systems on Tuesday,
indicating near-normal temperatures and isolated afternoon
showers.

The forecast for Wednesday to Friday (22nd-24th) is trending
wetter, dominated by a broad trough. Eighty percent of model
clusters maintain a closed low weather pattern with cool
temperatures and widespread precipitation. However, there are
still timing and strength differences regarding the potential low-
pressure system, making it difficult to pinpoint specific details.

&&

.AVIATION...Shower activity has begun to increase across western
Montana and north central Idaho early this morning. As the
atmosphere destabilizes through the day, the probability for
thunderstorms will increase, impacting most terminals through
roughly 20/0200Z. Snow levels will begin to lower, causing snow in
terrain above 6000 feet, with mountain obscurations becoming more
prevalent late this evening and overnight.

&&

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

$$