Area Forecast Discussion
Issued by NWS Missoula, MT

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FXUS65 KMSO 182037

Area Forecast Discussion
National Weather Service Missoula MT
237 PM MDT Wed May 18 2022

...Strong gusty winds to develop later this afternoon and through
the overnight hours...

.DISCUSSION...A strong cold front has begun to move through the
Northern Rockies this morning, that has brought an increase in
southwesterly winds. Later this evening, as the trough of lower
pressure deepens over the region, a strong upper-level jet stream
will traverse over the Pacific NW. This will bring even stronger
winds, with gusts potentially exceeding 40 mph over widespread
areas of western Montana. Locations with the highest probability
with seeing damaging winds, will be SW Montana in the
Butte/Blackfoot Region. As such, a High Wind Warning has been
issued for this location, that goes into effect at 9 PM this
evening until 6 AM tomorrow morning. All other locations in
western Montana and Lemhi County of Idaho, are, or will be under a
Wind Advisory over night through tomorrow afternoon.

The strong gusty winds are expected to greatly diminish after the
noon hour Thursday, but will remain breezy through the rest of the

Late Thursday and Thursday night a weather disturbance will move
into the region from Alberta Canada. This system is cold and wet.
Most precip will be along the continental divide. Snow levels
will crash to the valley floors by Friday morning. Several inches
of snow will occur at higher elevations with up to 4 inches of
snow over Marias and MacDonald passes. Road temperatures are
fairly warm so snow that does occur may be on the slushy side,
especially when daylight occurs. Snow, cold and wind will make
things miserable for back country hikers and campers. Prepare for
raw conditions.

Gusty winds will shift to the north to northeast Thursday
evening and overnight.

The expansive low pressure trough will maintain
its grip across much of the west, including the Northern Rockies,
through the weekend. Several pieces of energy or weather
disturbances will move through this trough resulting in numerous
showers each day. There will be a brief pause with the active
showery precipitation Monday with high temps returning to near
normal in the upper 60s.

Unfortunately a return to an active weather pattern will occur
Tuesday through much of next week.


.AVIATION...A cold front is approaching the Northern Rockies.
tightening pressure gradients and a strong jet will produce gusty
winds at the surface from the west to northwest. In fact 10kft
winds of 40-50kts will occur through 19/0600z. West to Northwest
winds will impact all terminals through Thursday afternoon. Peak
wind gusts are expected between 18/2300z and 19/0500z at all
terminals with gusts to 40 mph possible at KBTM. Rain showers will
be in the vicinity of all terminals from this afternoon through


MT...High Wind Warning from 9 PM this evening to 6 AM MDT Thursday
     Butte/Blackfoot Region.

     Wind Advisory from 6 PM to 9 PM MDT this evening Butte/Blackfoot

     Wind Advisory from 6 AM to 3 PM MDT Thursday Butte/Blackfoot

     Wind Advisory from 6 PM this evening to 3 PM MDT Thursday
     Bitterroot/Sapphire Mountains...Missoula/Bitterroot
     Valleys...Potomac/Seeley Lake Region.

     Wind Advisory from 6 PM this evening to midnight MDT tonight
     Lower Clark Fork Region.

     Lake Wind Advisory until 6 PM MDT this evening for Flathead Lake
     in the Flathead/Mission Valleys.

     Wind Advisory from 6 PM this evening to 3 PM MDT Thursday
     Flathead/Mission Valleys...West Glacier Region.

     Wind Advisory from 6 PM this evening to midnight MDT tonight
     Kootenai/Cabinet Region.

ID...Wind Advisory from midnight tonight to 3 PM MDT Thursday Eastern
     Lemhi County...Western Lemhi County.


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