853 
FXUS65 KMSO 141721
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
1021 AM MST Mon Jan 14 2013

.UPDATE...Snow was increasing across northern Idaho and into
western Montana this morning. Added White Bird Grade in north-
central Idaho to the Winter Weather Advisory mix. Also, a Flood
Watch was issued for the Salmon River near Salmon, Idaho for ice
jam flooding potential.


&&

.AVIATION...A wide area of stratus is lowering this morning in
Idaho and western Montana and will continue to do so through
today. An area of snow to the north and west of the region will
spread through Idaho and western Montana through this morning with
widespread lowered visibilities likely by this morning due to light
snow. Majority of the region will have obscured terrain and snow
accumulations into tonight. Some drier air will arrive on Tuesday
and should help to decrease snow coverage and promote less cloud
cover.



&&

.PREV DISCUSSION... /ISSUED 818 AM MST Mon Jan 14 2013/ 

UPDATE...Snow was advancing across northern Idaho and into
western Montana this morning. The temperature/moisture profile at
the lower levels favorable for snow growth and Winter Weather
Advisories remain in the weather picture for today. Snow falling
on top of already icy/hard-packed snow covered road will make
driving condition very slick.  

AVIATION...A wide area of stratus is lowering this morning in
Idaho and western Montana and will continue to do so through
today. An area of snow to the north and west of the region will
spread through Idaho and western Montana through this morning with
widespread lowered visibilities likely by this morning due to light
snow. Majority of the region will have obscured terrain and snow
accumulations into tonight. Some drier air will arrive on Tuesday
and should help to decrease snow coverage and promote less cloud
cover.

PREV DISCUSSION... /ISSUED 324 AM MST Mon Jan 14 2013/ 

.Snow accumulations are expected through today and into tonight...
.Cold temperatures will continue to lead to ice jam concerns...

DISCUSSION...Radar returns are starting to enhance around Spokane
early this morning in association with the next weather system
moving into the region. Model guidance seem to be doing an okay
job with the moisture placement but there does seem to be some
struggle with the amount of precipitation, which is not uncommon
in a weakly forced/cold environment like the one we have. The
profile continuous to favor snow that is expected to gradually
increase through the morning throughout the region. Current
conditions and model trends maintain that the winter weather
advisories for today and tonight are still relevant with a couple
of inches of low density snow by this evening in most places.
Snow will gradually taper off tonight but there are some
indications that light snow could linger into Tuesday.

Temperatures will remain very cold with valley cold pools
beginning to become more pronounced Tuesday afternoon and
Wednesday morning. Wednesday through Sunday will see a ridge of
high pressure become the dominant weather feature. Stable, dry
conditions are expected with patches of valley fog developing.
Surface based inversions will strengthen during the overnight
periods with little if any mixing. In addition, valleys will
remain colder than normal with a continuation of ice forming on
areas rivers. 

AVIATION...A wide area of stratus is lowering this morning in
Idaho and western Montana and will continue to do so through
today. An area of snow to the north and west of the region will
spread through Idaho and western Montana through this morning with
widespread lowered visibilities likely by this morning due to light
snow. Majority of the region will have obscured terrain and snow
accumulations into tonight. Some drier air will arrive on Tuesday
and should help to decrease snow coverage and promote less cloud
cover.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY until 11 PM MST this evening 
     Missoula/Bitterroot Valleys.

     WINTER WEATHER ADVISORY until 11 PM MST this evening 
     Flathead/Mission Valleys.

     WINTER WEATHER ADVISORY until 11 PM MST this evening 
     Potomac/Seeley Lake Region...West Glacier Region.

     WINTER WEATHER ADVISORY until 5 PM MST this afternoon 
     Kootenai/Cabinet Region...Lower Clark Fork Region.

     WINTER WEATHER ADVISORY until 11 PM MST this evening 
     Bitterroot/Sapphire Mountains.

ID...WINTER WEATHER ADVISORY until 10 PM PST this evening ABOVE 2500 
     FEET FOR THE Lower Hells Canyon/Salmon River Region.

     WINTER WEATHER ADVISORY until 4 PM PST this afternoon Northern 
     Clearwater Mountains...Orofino/Grangeville Region.

     WINTER WEATHER ADVISORY until 10 PM PST this evening Southern 
     Clearwater Mountains.

&&

$$

Follow us on Facebook and Twitter!
https://www.facebook.com/US.NationalWeatherService.Missoula.gov
https://www.twitter.com/NWSMissoula