Special Weather Statement, NWS Missoula, MT

Area Forecast Discussion
National Weather Service Missoula MT
236 PM MDT Wed Jul 13 2022

.DISCUSSION...Showers and thunderstorms have been active across
the Northern Rockies since this morning. This trend is expected
to continue through the afternoon with the main threats being
lightning and gusty outflows. We have received a couple reports of
storms being wet as well, so a brief heavy downpour or small hail
cannot be ruled out. Late this afternoon, thunderstorm threat will
shift into Lemhi county, Idaho and southwest Montana. These areas
have the potential to see outflow winds of 35 to 40 mph, with a 5
percent chance of up to 60 to 70 mph.

Above normal heat will persist into Thursday and Friday, with
high temperatures averaging 5-10 degrees above normal. One change
will be a relatively dry airmass working into our area from north
to south beginning this evening. There are still questions in the
models on how far south the dry air will spread by Friday, which
makes the convection forecast difficult. Expect summertime
thunderstorms to pop up each day, with Lemhi County and southwest
Montana having the highest chance to experience one. On Friday,
the models are depicting an open wave moving through the Northern
Rockies, however there is little confidence on the exact position.
If the GFS (Global Forecast System) is correct, then southwest
Montana will experience increased convective activity Friday
afternoon.

This weekend will be hot and dry! Please exercise caution while
recreating or working outside, taking frequent breaks and staying
hydrated when possible. Overnight temperatures will be slow to
cool off as well, so be sure to check on the most vulnerable in
your community.

&&

.AVIATION...Widespread light showers and isolated thunderstorms
will continue to develop over Idaho and slowly move to the east-
northeast across western Montana through the evening. Terminals
with the highest probability for thunderstorms, will be KBTM,
where the strongest thunderstorms are expected to be. The timing
for thunderstorm activity, will be from 13/2000Z to 14/0000Z this
evening. Gusty winds up to 40kts with frequent lightning will be
the primary threats. Brief heavy rain may also lower visibility
for short periods of time. While the chances for convection is
much lower, vicinity thunder is possible for KMSO and KGPI during
the same time as above.

&&

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