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Area forecast discussion 
National Weather Service Missoula Montana
416 am MDT Wednesday Aug 5 2015

Discussion...showers and a few thunderstorms have formed
overnight in the southwest flow ahead of an approaching low
pressure weather system. The bands of showers currently over north
central Idaho and western Montana will continue to expand and
migrate east throughout the day. Locations southeast of a Grangeville,
Idaho to Seeley Lake, Montana line have the best chance for thunderstorms
this afternoon. This includes locations such as Hamilton, Salmon,
Butte, and Anaconda. Brief heavy rain, lightning, and gusty winds
will be the main threats with these storms. Northwest Montana will
miss out on most of the precipitation, but breezy west winds will
be ubiquitous this afternoon, with the whole area experiencing the
effects of a tightening pressure gradient. Thunderstorm activity
will subside after sunset as storms move east into central and
eastern Montana, but winds will remain breezy in the terrain

Relatively dry westerly flow will develop over the northern
rockies on Thursday, transitioning to a ridge of high pressure on
Friday. One exception to dry conditions will be northwest Montana
from Kalispell northward, where some fast moving high-elevation
showers and thunderstorms will be present at times. Gusty winds
are expected to intensify during Thursday afternoon, particularly
across northwest Montana. Gusts will generally be in the 20 to 30
mph range, with the peak wind in the late afternoon. Boaters on
large lakes, such as Flathead Lake, may experience increased wave
activity late Thursday afternoon and evening as well. Winds are
anticipated to be much weaker on Friday, with dry conditions
throughout the region.

Southwesterly flow aloft will return to the northern rockies on
Saturday and continue through at least the middle of next week.
Similar to the current weather scenario, daily shower and
thunderstorm activity peaking during the afternoon and evening
hours appears plausible. Models suggest that daytime temperatures
will be settling near the seasonal average over the long range


Aviation....light showers currently seen on radar will continue
to expand in coverage throughout the morning. Kmso and kgpi both
have a slight chance of seeing a vicinity shower, but the better
location for widespread showers will be ksmn. During the
afternoon, showers will transition into scattered thunderstorms,
with areas near ksmn and kbtm being the most likely to see
lightning strikes. Ceilings around 8 to 10 thousand feet agl with
breezy afternoon winds are expected this afternoon with the
passage of this weather system.


Mso watches/warnings/advisories...


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