889
FXUS65 KMSO 131003
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
403 AM MDT Tue Aug 13 2024

.DISCUSSION...Another weak disturbance is moving through northwest
Montana early this morning causing a few scattered showers and
isolated thunderstorms. This round of convection will move off
into Canada by late morning. A more significant disturbance is
currently over southern Idaho and will move up into north central
Idaho, west central and southwest Montana today. Then this
afternoon stronger storms are anticipated to develop across west
central and southwest Montana with the capability of heavy rain.
Temperatures today are expected to be 5 to 10 degrees cooler
compared to yesterday.

A weak ridge of high pressure slides over the Northern Rockies on
Wednesday allowing for a decrease in the potential for convection.
This respite in convection will be short-lived as another
disturbance makes its way through the Northern Rockies on
Thursday into Friday. This feature will once again bring
scattered to widespread showers and thunderstorms to the region.

After the passage of this disturbance, a ridge of high pressure
appears to develop over the Northern Rockies as a significant low
pressure system digs along the Pacific coast. This ridge will
cause some warming and drying over the region. The models start to
diverge on their solutions for the low pressure system off the
coast. Around 60% of the models have the low move slightly inland
causing the upper level flow to become southwesterly by Sunday which
is conducive to the development of stronger thunderstorms over the
Northern Rockies. While around 25% keep the low off the coast
more, meaning a ridge of high pressure for the Northern Rockies.


&&

.AVIATION...A disturbance is causing a line of showers to move
through northwest Montana early this morning. A larger disturbance
over southern Idaho will move into the region by mid morning
causing widespread showers and thunderstorm. This afternoon
portions of west central and southwest Montana could be affect by
stronger thunderstorm with the potential of heavy rain and some
hail. All terminals will be affected by convection throughout the
day.


&&

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

&&

$$