Winter Storm Warning 8, NWS Missoula, MT

617 
WWUS45 KMSO 170949
WSWMSO

URGENT - WINTER WEATHER MESSAGE
National Weather Service Missoula MT
349 AM MDT Wed Jun 17 2020

MTZ043-171100-
/O.CAN.KMSO.WW.Y.0045.000000T0000Z-200617T1500Z/
Potomac/Seeley Lake Region-
349 AM MDT Wed Jun 17 2020

...WINTER WEATHER ADVISORY IS CANCELLED...

Snow levels will not come down far enough so any snow
accumulations will be in the higher terrain.

$$

MTZ007-171800-
/O.CON.KMSO.WS.W.0008.000000T0000Z-200617T1800Z/
Butte/Blackfoot Region-
349 AM MDT Wed Jun 17 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL NOON MDT TODAY...

* WHAT...Heavy snow. For elevations 6000 feet and higher: total
  snow accumulations of up to 8 inches possible. Locally higher
  amounts of 12 to 15 inches possible in the highest terrain
  (above roughly 7000 feet). For elevations below 6000 feet: snow
  accumulations of up to two inches with isolated higher amounts.

* WHERE...Butte, Georgetown Lake, Highway 12 Garrison to 
  Elliston, Homestake Pass, and MacDonald Pass.

* WHEN...Until noon MDT today.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

MTZ006-171800-
/O.CON.KMSO.WS.W.0008.000000T0000Z-200617T1800Z/
Bitterroot/Sapphire Mountains-
349 AM MDT Wed Jun 17 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL NOON MDT TODAY...

* WHAT...Heavy snow. Additional snow accumulations of up to 4 
  inches.

* WHERE...Bitterroot/Sapphire Mountains.

* WHEN...Until noon MDT today.

* IMPACTS...Travel could be affected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IDZ009-010-171800-
/O.CON.KMSO.WS.W.0008.000000T0000Z-200617T1800Z/
Western Lemhi County-Eastern Lemhi County-
349 AM MDT Wed Jun 17 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL NOON MDT TODAY...

* WHAT...Heavy snow. For elevations 6000 feet and higher: total
  snow accumulations of up to 6 inches possible. Locally higher
  amounts of 10 to 12 inches possible in the highest terrain. For
  elevations below 6000 feet: snow accumulations of up to two 
  inches with isolated higher amounts.

* WHERE...Shoup, Bannock Pass, Highway 28 Tendoy to Lone Pine, 
  Highway 93 Lost Trail Pass to Gibbonsville, Lemhi Pass, and 
  Salmon.

* WHEN...Until noon MDT today.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IDZ006-171500-
/O.CON.KMSO.WW.Y.0045.000000T0000Z-200617T1500Z/
Southern Clearwater Mountains-
249 AM PDT Wed Jun 17 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS
MORNING...

* WHAT...Snow. Additional snow accumulations of up to two inches.

* WHERE...Dixie and Highway 12 over Lolo Pass.

* WHEN...Until 8 AM PDT this morning.

* IMPACTS...Travel could be affected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

328 
WWUS45 KMSO 171432
WSWMSO

URGENT - WINTER WEATHER MESSAGE
National Weather Service Missoula MT
832 AM MDT Wed Jun 17 2020

IDZ009-010-MTZ006-007-171545-
/O.CAN.KMSO.WS.W.0008.000000T0000Z-200617T1800Z/
Western Lemhi County-Eastern Lemhi County-
Bitterroot/Sapphire Mountains-Butte/Blackfoot Region-
832 AM MDT Wed Jun 17 2020

...WINTER STORM WARNING IS CANCELLED...

Snow continues above 6000 feet but impacts are waning. 

$$

IDZ006-171545-
/O.CAN.KMSO.WW.Y.0045.000000T0000Z-200617T1500Z/
Southern Clearwater Mountains-
732 AM PDT Wed Jun 17 2020

...WINTER WEATHER ADVISORY IS CANCELLED...

Snow continues above 6000 feet but impacts are waning. 

$$

Area Forecast Discussion...CORRECTED
National Weather Service Missoula MT
607 AM MDT Tue Jun 16 2020

...Significant Mountain Snow Tonight into Wednesday for North
Central Idaho into Southwest Montana...

.DISCUSSION...Another abnormally cold trough of low pressure will
continue to impact the Northern Rockies for the next couple of
days. This trough will keep temperatures well below normal for
this time of year while bringing widespread precipitation.
Scattered to numerous showers will traverse the region throughout
the day.

Tonight a mid level circulation will make its way across the
Northern Rockies. The circulation wraps a plume of moisture across
portions of north central Idaho into west central and southwest
Montana. The models diverge slightly on the exact placement of
the heaviest band of precipitation. The general consensus appears
to have the heaviest precipitation over Idaho and Lemhi counties
stretching into western Montana south of the Highway 200 corridor.
The cold air associated with this feature will cause snow levels
to drop dramatically by Wednesday morning being around 5000 to
5500 feet. It would not be surprising if snow levels lower even
further under the heaviest precipitation band, maybe even down to
4000 feet. Currently the most impactful snow appears to be across
the higher terrain of Lemhi county into southwest Montana by
Wednesday morning, as several winter storm watches have been
issued. An area that could be impacted is the higher elevations of
Idaho county, especially over Whitebird Grade and the community of
Dixie. This system appears to have similar snow accumulations to
the previous snow event from a week ago, where high elevations
communities of southwest Montana received 2 to 6 inches with local
areas getting over a foot of new snow. This type of snow during
this time of year will have a major impact on trees potentially
creating power outages.

The trough of low pressure shifts off to the east during the day
Wednesday leaving the Northern Rockies under northwester flow
aloft. This flow pattern is conducive to lingering showers and a
cooler airmass. The mountains along the Continental Divide should
anticipate continued snow, especially in the Glacier National
Park region through Thursday.

A low amplitude ridge of high pressure builds over the region
Friday into the weekend. This ridge will bring temperatures back
to seasonal readings by Saturday. Subtle features traversing the
region in this flow pattern could cause scattered showers,
especially during the afternoon and evening hours.

&&

.AVIATION...Scattered to numerous showers will traverse the
Northern Rockies today causing periods of reduced visibilities and
ceilings across all terminals. This evening, a mid level
circulation will make its way into Lemhi county and southwest
Montana. This feature will bring a plume of significant
precipitation to the region. Snow levels will drop dramatically
throughout the night causing the precipitation to change over to
snow around 5000 feet. This snow level could be even lower under
the heaviest precipitation. KBTM appears to transition over to
steady rain around 16/23z and then change over to snow around
17/12z. KSMN experiences the steady rain around 17/10z and could
experience a rain/snow mix by 17/15z. Steady rain is expected for
KMSO between 17/03z to 17/12z, but not anticipating snow.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Watch from this evening through Wednesday morning
     Butte/Blackfoot Region.

     Winter Storm Watch from this evening through Wednesday morning
     Bitterroot/Sapphire Mountains.

ID...Winter Storm Watch from this evening through Wednesday morning
     Eastern Lemhi County...Western Lemhi County.

&&