Strong Wind in Montana, August 14, 2012

Area Forecast Discussion
National Weather Service Missoula MT
255 PM MDT Tue Aug 14 2012

.DISCUSSION...Active weather is in store for the next 24 hours as
a weather system approaches the region from British Columbia.
Ahead of this feature today, high fire danger will continue to be
present due to low humidity and gusty west winds. Red flag
warnings remain in place for portions of southwest and west
central Montana. This evening, the approaching weather system will
move south from Canada and swing a cold front across the
Continental Divide. This will have several impacts across mainly
western Montana. 1) Winds will shift from a westerly direction
this afternoon to northeast or east direction tonight. Winds could
become quite gusty (up to 30 mph) through favored east/west
oriented canyons. Choppy conditions can be expected for boaters on
area lakes through Wednesday. 2) Showers and isolated thunderstorms are
expected to develop with this system tonight, especially across
northwest Montana and along the Continental Divide. Probability
of measurable rain will be high in areas such as Glacier National
Park, but fairly low as you move to the south and west of Glacier
Park. Snow levels will lower in Glacier Park tonight to around
7500 feet which will produce the potential for light snow in the
higher terrain of the park late tonight into early Wednesday
morning. 3) Cooler temperatures will follow the cold front for
tomorrow bringing brief relief from the above normal temperatures
seen in the region of late.

The ridge of high pressure will quickly rebuild into the region
beginning on Thursday and lasting into next weekend. This will
allow temperatures to warm back to above normal for this time of
year with dry conditions continuing.

Forecast models begin to diverge with the timing of breaking down
the ridge of high pressure starting early next week. Models either
have a storm system moving into the northern Rockies for the start
of next week or have the ridge hanging on till the mid part of the
week. Didn't make many changes to the extended forecast, however
western Montana and central Idaho does look to be under a south
westerly flow either way, so did bump up chances for precipitation
to at least climatological values for portions of western Montana.

&&

.AVIATION...Smoke from wildfires will maintain throughout the
region today, especially in the vicinity of KSMN. Winds will
continue to strengthen this afternoon from a westerly direction,
with gusts of 30 to 35 kts possible area wide. This wind should
increase smoke production, so low visibility is again going to
plague KSMN. A weather system will drop out of British Columbia tonight
that will produce an easterly pressure gradient with increased
east winds first at KGPI by early morning and KMSO closer to
sunrise. Cloud cover will also increase with the trough and there
will be chances for showers especially along the Continental Divide.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING until 9 PM MDT this evening Bitterroot/Sapphire
     Mountains...Butte/Blackfoot Region...Missoula/Bitterroot
     Valleys...Potomac/Seeley Lake Region.

ID...RED FLAG WARNING until 9 PM MDT /8 PM PDT/ this evening Eastern
     Lemhi County...Southern Clearwater Mountains...Western
     Lemhi County.

&&