Area Forecast Discussion
Issued by NWS Missoula, MT

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FXUS65 KMSO 262023

Area Forecast Discussion
National Weather Service Missoula MT
223 PM MDT Mon Jul 26 2021

.DISCUSSION...Radar returns, and even some lightning, have been
observed in northeast Oregon today, which is where the beginning
of our influx of monsoon moisture resides. Cloud cover will
continue to increase during this afternoon from the southwest in
association with incoming moisture.

Dry air currently in place, cloud cover, and smoke will limit any
convective activity today, and radar projections show that any
thunderstorms will develop on either side of a line about from
Lost Trail Pass to Anaconda into this evening. Showers then become
possible in north central Idaho late this evening and in
northwest Montana overnight. Confidence is low, but an isolated
thunderstorm could develop within the area of showers.

Model guidance is in good agreement for well above normal
moisture to be over Idaho and western Montana beginning Tuesday
and remaining for most of the week. Thunderstorms are expected
each afternoon, especially south of I-90, but thunderstorms will
also be possible Wednesday night in northwest Montana.


.AVIATION...Decreased visibility due to wildfire smoke across the
Northern Rockies airspace will continue this afternoon through
Tuesday. Smoke will be an issue at terminal locations and will
obscure terrain over all mountain ranges in the region. KSMN and
KBTM will see a slight chance for thunderstorms this afternoon,
although confidence is low. On Tuesday, monsoonal moisture arrives
by the afternoon, bringing a better chance for afternoon and
evening thunderstorms to KSMN and KBTM.



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