Alert archive / Montana / Winter Storm Warnings in 2021

Winter Storm Warning 8, NWS Missoula, MT

February 21, 2021Flathead County, Lake County, Montana

NWS Missoula, MT issued this winter storm warning at Feb 21, 2021, 7:30 PM MST for Flathead County, Lake County, Montana. It took effect at Feb 22, 2021, 5:00 AM MST. It was in force for 23 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Feb 21, 2021, 7:30 PM MST (02:30 UTC)
In effect from
Feb 22, 2021, 5:00 AM MST
Expired
Feb 23, 2021, 3:42 AM MST
In force
23 hr
Issued by
NWS Missoula, MT

Counties Flathead County, MT, Lake County, MT

The radar

The Missoula radar (KMSX), 104 km from the middle of the area, began a volume at 02:36 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Spokane, WA (KOTX), launched 00:00Z, 2.5 hours before the alert went out and 177 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Spokane, WA at 00:00Z on 2021-02-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Spokane, WA at 00:00Z on 2021-02-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 354 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
769 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
354 m²/s²
0-3 km storm-relative helicity
455 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

079 
WWUS45 KMSO 220230
WSWMSO

URGENT - WINTER WEATHER MESSAGE
National Weather Service Missoula MT
730 PM MST Sun Feb 21 2021

MTZ002-230230-
/O.CAN.KMSO.WS.W.0007.000000T0000Z-210222T1800Z/
/O.NEW.KMSO.WS.W.0008.210222T1200Z-210223T1200Z/
West Glacier Region-
730 PM MST Sun Feb 21 2021

...WINTER STORM WARNING IN EFFECT FROM 5 AM MONDAY TO 5 AM MST
TUESDAY...

* WHAT...Heavy snow and blowing snow expected. Total snow
  accumulations of 5 to 10 inches between Essex and Marias Pass.
  Total snow accumulations of 1 to 3 inches at lower elevations.
  Winds gusting as high as 55 mph.

* WHERE...Essex, Swan Lake, Marias Pass, and Polebridge.

* WHEN...From 5 AM Monday to 5 AM MST Tuesday.

* IMPACTS...Travel could be very difficult to impossible.
  Widespread blowing snow could significantly reduce visibility.
  Strong winds could cause tree damage.

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.

&&

$$

MTZ006-230230-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T0600Z/
Bitterroot/Sapphire Mountains-
730 PM MST Sun Feb 21 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 PM MST
MONDAY...

* WHAT...Snow. Total snow accumulations of 4 to 8 inches for 
  Lost Trail Pass and the Sapphire Mountains, with 1 to 2 feet 
  expected above 4,500 feet in the Bitterroot Mountains. Winds 
  gusting as high as 50 mph.

* WHERE...Bitterroot/Sapphire Mountains.

* WHEN...Until 11 PM MST Monday.

* IMPACTS...Travel could be affected. The combination of heavy 
  snow and strong winds will create dangerous backcountry travel 
  conditions, particularly in the Bitterroot Mountains.

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.

&&

$$

IDZ005-006-230230-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T0600Z/
Northern Clearwater Mountains-Southern Clearwater Mountains-
630 PM PST Sun Feb 21 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST
MONDAY ABOVE 4000 FEET...

* WHAT...Snow above 4000 feet. Total snow accumulations 6 to 12 
  inches between 4,000 and 4,500 feet, with 1 to 2 feet expected 
  above 4,500 feet. Winds gusting as high as 45 mph.

* WHERE...Northern Clearwater Mountains and Southern Clearwater 
  Mountains.

* WHEN...Until 10 PM PST Monday.

* IMPACTS...Travel could be affected. The combination of heavy 
  snow and strong winds will create dangerous backcountry travel 
  conditions.

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.

&&

$$

MTZ004-230230-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T0600Z/
Lower Clark Fork Region-
730 PM MST Sun Feb 21 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 PM MST
MONDAY ABOVE 4000 FEET...

* WHAT...Snow above 4000 feet. Total snow accumulations of 7 to 
  12 inches for Lookout Pass. Winds gusting as high as 45 mph.

* WHERE...Lower Clark Fork Region.

* WHEN...Until 11 PM MST Monday.

* IMPACTS...Travel could be affected. Patchy areas of blowing 
  snow could significantly reduce visibility. Gusty winds could 
  bring down tree branches.

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.

&&

$$
3 follow-up statements
847 
WWUS45 KMSO 221012
WSWMSO

URGENT - WINTER WEATHER MESSAGE
National Weather Service Missoula MT
312 AM MST Mon Feb 22 2021

MTZ002-231015-
/O.CON.KMSO.WS.W.0008.210222T1200Z-210223T1200Z/
West Glacier Region-
312 AM MST Mon Feb 22 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
TUESDAY...

* WHAT...Heavy snow and blowing snow expected. Total snow
  accumulations of 5 to 10 inches between Essex and Marias Pass.
  Total snow accumulations of 1 to 3 inches at lower elevations
  occurring along the cold front in the evening. Winds gusting to
  60 mph.

* WHERE...Essex, Swan Lake, Marias Pass, and Polebridge.

* WHEN...From 5 AM Monday to 5 AM MST Tuesday.

* IMPACTS...Travel could be very difficult to impossible. 
  Widespread blowing snow could significantly reduce visibility. 
  Strong winds could cause tree damage.

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.

&&

$$

MTZ005-231015-
/O.EXB.KMSO.WW.Y.0022.210223T0300Z-210223T1400Z/
Missoula/Bitterroot Valleys-
312 AM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO
7 AM MST TUESDAY...

* WHAT...Fast snow accumulation of 1 to 3 inches. Winds gusting 
  to 40 mph. Visibility less than 1 mile at times.

* WHERE...Missoula/Bitterroot Valleys.

* WHEN...From 8 PM this evening to 7 AM MST Tuesday.

* IMPACTS...Travel will be difficult following a cold front this 
  evening. Patchy areas of blowing snow could significantly reduce
  visibility. Gusty winds could bring down tree branches.

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.

&&

$$

MTZ043-231015-
/O.EXB.KMSO.WW.Y.0022.210223T0300Z-210223T1400Z/
Potomac/Seeley Lake Region-
312 AM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO
7 AM MST TUESDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 5 inches.
  Winds gusting as high as 40 mph. Visibility less than 1 mile at
  times.

* WHERE...Highway 200 Bonner to Greenough, Highway 83 Seeley 
  Lake to Condon, and I-90 East Missoula to Bearmouth.

* WHEN...From 8 PM this evening to 7 AM MST Tuesday.

* IMPACTS...Travel will be difficult following a cold front this 
  evening. Patchy areas of blowing snow could significantly reduce
  visibility. Gusty winds could bring down tree branches.

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.

&&

$$

MTZ007-231015-
/O.EXB.KMSO.WW.Y.0022.210223T0300Z-210223T1400Z/
Butte/Blackfoot Region-
312 AM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO
7 AM MST TUESDAY...

* WHAT...Fast snow accumulation of 1 to 3 inches. Winds gusting 
  as high as 40 mph. Visibility less than 1 mile at times.

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

* WHEN...From 8 PM this evening to 7 AM MST Tuesday.

* IMPACTS...Travel will be difficult following a cold front this 
  evening. Patchy areas of blowing snow could significantly reduce
  visibility. Gusty winds could bring down tree branches.

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.

&&

$$

MTZ006-230600-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T0600Z/
Bitterroot/Sapphire Mountains-
312 AM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 PM MST THIS
EVENING...

* WHAT...Snow. Total snow accumulations of 4 to 8 inches for 
  Lost Trail Pass and the Sapphire Mountains, with 1 to 2 feet 
  expected above 4,500 feet in the Bitterroot Mountains. Winds 
  gusting as high as 50 mph.

* WHERE...Bitterroot/Sapphire Mountains.

* WHEN...Until 11 PM MST Monday.

* IMPACTS...Travel could be affected. The combination of heavy 
  snow and strong winds will create dangerous backcountry travel 
  conditions, particularly in the Bitterroot Mountains.

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.

&&

$$

IDZ005-006-230600-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T0600Z/
Northern Clearwater Mountains-Southern Clearwater Mountains-
212 AM PST Mon Feb 22 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS
EVENING...

* WHAT...Snow above 4000 feet. Total snow accumulations 6 to 12 
  inches between 4,000 and 4,500 feet, with 1 to 2 feet expected 
  above 4,500 feet. Winds gusting as high as 45 mph.

* WHERE...Northern Clearwater Mountains and Southern Clearwater 
  Mountains.

* WHEN...Until 10 PM PST Monday.

* IMPACTS...Travel could be affected. The combination of heavy 
  snow and strong winds will create dangerous backcountry travel 
  conditions.

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.

&&

$$

MTZ004-230600-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T0600Z/
Lower Clark Fork Region-
312 AM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 PM MST THIS
EVENING ABOVE 4000 FEET...

* WHAT...Snow above 4000 feet. Total snow accumulations of 7 to 
  12 inches for Lookout Pass. Winds gusting as high as 45 mph.

* WHERE...Lower Clark Fork Region.

* WHEN...Until 11 PM MST Monday.

* IMPACTS...Travel could be affected. Patchy areas of blowing 
  snow could significantly reduce visibility. Gusty winds could 
  bring down tree branches.

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.

&&

$$
194 
WWUS45 KMSO 222028
WSWMSO

URGENT - WINTER WEATHER MESSAGE
National Weather Service Missoula MT
128 PM MST Mon Feb 22 2021

MTZ002-231200-
/O.CON.KMSO.WS.W.0008.000000T0000Z-210223T1200Z/
West Glacier Region-
128 PM MST Mon Feb 22 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
TUESDAY...

* WHAT...Heavy snow and blowing snow expected. Total snow 
  accumulations of 5 to 10 inches between Essex and Marias Pass. 
  Total snow accumulations of 1 to 3 inches at lower elevations 
  occurring along the cold front in the evening. Winds gusting 
  to 60 mph.

* WHERE...Bad Rock Canyon, Essex, Highway 83 Bigfork to Swan 
  Lake, Marias Pass, and Polebridge.

* WHEN...Until 5 AM MST Tuesday.

* IMPACTS...Travel could be very difficult to impossible. 
  Widespread blowing snow could significantly reduce visibility. 
  Strong winds could cause tree damage.

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.

&&

$$

MTZ006-231200-
/O.EXT.KMSO.WW.Y.0022.000000T0000Z-210223T1200Z/
Bitterroot/Sapphire Mountains-
128 PM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 5 AM MST TUESDAY...

* WHAT...Snow. Total snow accumulations of 4 to 8 inches for 
  Lost Trail Pass and the Sapphire Mountains, with 1 to 2 feet 
  expected above 4,500 feet in the Bitterroot Mountains. Winds 
  gusting as high as 50 mph.

* WHERE...Bitterroot/Sapphire Mountains.

* WHEN...Until 5 AM MST Tuesday.

* IMPACTS...Travel could be affected. The combination of heavy 
  snow and strong winds will create dangerous backcountry travel 
  conditions, particularly in the Bitterroot Mountains.

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.

&&

$$

IDZ005-006-231200-
/O.EXT.KMSO.WW.Y.0022.000000T0000Z-210223T1200Z/
Northern Clearwater Mountains-Southern Clearwater Mountains-
1228 PM PST Mon Feb 22 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 4 AM PST TUESDAY...

* WHAT...Snow above 4000 feet. Total snow accumulations 6 to 12 
  inches between 4,000 and 4,500 feet, with 1 to 2 feet expected 
  above 4,500 feet. Winds gusting as high as 45 mph.

* WHERE...Southern Clearwater Mountains and Northern Clearwater 
  Mountains.

* WHEN...Until 4 AM PST Tuesday.

* IMPACTS...Travel could be affected. The combination of heavy 
  snow and strong winds will create dangerous backcountry travel 
  conditions.

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.

&&

$$

MTZ004-231200-
/O.EXT.KMSO.WW.Y.0022.000000T0000Z-210223T1200Z/
Lower Clark Fork Region-
128 PM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 5 AM MST TUESDAY
ABOVE 4000 FEET...

* WHAT...Snow above 4000 feet. Total snow accumulations of 7 to 
  12 inches for Lookout Pass. Winds gusting as high as 45 mph.

* WHERE...Lower Clark Fork Region.

* WHEN...Until 5 AM MST Tuesday.

* IMPACTS...Travel could be affected. Patchy areas of blowing 
  snow could significantly reduce visibility. Gusty winds could 
  bring down tree branches.

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.

&&

$$

MTZ005-231400-
/O.CON.KMSO.WW.Y.0022.210223T0300Z-210223T1400Z/
Missoula/Bitterroot Valleys-
128 PM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 8 PM THIS
EVENING TO 7 AM MST TUESDAY...

* WHAT...Fast snow accumulation of 1 to 3 inches. Winds gusting 
  to 40 mph. Visibility less than 1 mile at times.

* WHERE...Missoula/Bitterroot Valleys.

* WHEN...From 8 PM this evening to 7 AM MST Tuesday.

* IMPACTS...Travel will be difficult following a cold front this 
  evening. Patchy areas of blowing snow could significantly 
  reduce visibility. Gusty winds could bring down tree branches.

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.

&&

$$

MTZ043-231400-
/O.CON.KMSO.WW.Y.0022.210223T0300Z-210223T1400Z/
Potomac/Seeley Lake Region-
128 PM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 8 PM THIS
EVENING TO 7 AM MST TUESDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 5 
  inches. Winds gusting as high as 40 mph. Visibility less than 
  1 mile at times.

* WHERE...Highway 200 Bonner to Greenough, Highway 83 Seeley 
  Lake to Condon, and I-90 East Missoula to Bearmouth.

* WHEN...From 8 PM this evening to 7 AM MST Tuesday.

* IMPACTS...Travel will be difficult following a cold front this 
  evening. Patchy areas of blowing snow could significantly 
  reduce visibility. Gusty winds could bring down tree branches.

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.

&&

$$

MTZ007-231400-
/O.CON.KMSO.WW.Y.0022.210223T0300Z-210223T1400Z/
Butte/Blackfoot Region-
128 PM MST Mon Feb 22 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 8 PM THIS
EVENING TO 7 AM MST TUESDAY...

* WHAT...Fast snow accumulation of 1 to 3 inches. Winds gusting 
  as high as 40 mph. Visibility less than 1 mile at times.

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

* WHEN...From 8 PM this evening to 7 AM MST Tuesday.

* IMPACTS...Travel will be difficult following a cold front this 
  evening. Patchy areas of blowing snow could significantly 
  reduce visibility. Gusty winds could bring down tree branches.

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.

&&

$$
256 
WWUS45 KMSO 231042
WSWMSO

URGENT - WINTER WEATHER MESSAGE
National Weather Service Missoula MT
342 AM MST Tue Feb 23 2021

MTZ002-231700-
/O.CAN.KMSO.WS.W.0008.000000T0000Z-210223T1200Z/
/O.EXB.KMSO.WW.Y.0022.000000T0000Z-210223T1700Z/
West Glacier Region-
342 AM MST Tue Feb 23 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 AM MST THIS
MORNING...
...WINTER STORM WARNING IS CANCELLED...

* WHAT...Snow. Additional snow accumulations of up to two 
  inches. Winds gusting as high as 35 mph.

* WHERE...Bad Rock Canyon, Essex, and Marias Pass.

* WHEN...Until 10 AM MST this morning.

* IMPACTS...Travel could be affected. Widespread blowing snow 
  could significantly reduce visibility.

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.

&&

$$

MTZ001-003-231700-
/O.EXB.KMSO.WW.Y.0022.000000T0000Z-210223T1700Z/
Kootenai/Cabinet Region-Flathead/Mission Valleys-
342 AM MST Tue Feb 23 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 AM MST THIS
MORNING...

* WHAT...Snow. Additional snow accumulations of up to one inch.

* WHERE...Kootenai/Cabinet Region and Flathead/Mission Valleys.

* WHEN...Until 10 AM MST this morning.

* IMPACTS...Travel could be affected. Patchy blowing snow could 
  significantly reduce visibility.

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.

&&

$$

MTZ005-231700-
/O.EXT.KMSO.WW.Y.0022.000000T0000Z-210223T1700Z/
Missoula/Bitterroot Valleys-
342 AM MST Tue Feb 23 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 10 AM MST THIS
MORNING...

* WHAT...Snow. Additional snow accumulations of up to one inch.

* WHERE...Missoula/Bitterroot Valleys.

* WHEN...Until 10 AM MST 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.

&&

$$

MTZ043-231700-
/O.EXT.KMSO.WW.Y.0022.000000T0000Z-210223T1700Z/
Potomac/Seeley Lake Region-
342 AM MST Tue Feb 23 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 10 AM MST THIS
MORNING...

* WHAT...Snow. Additional snow accumulations of up to two 
  inches. Winds gusting as high as 35 mph.

* WHERE...Highway 200 Bonner to Greenough, Highway 83 Seeley 
  Lake to Condon, and I-90 East Missoula to Bearmouth.

* WHEN...Until 10 AM MST this morning.

* IMPACTS...Travel could be affected. Widespread blowing snow 
  could significantly reduce visibility.

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.

&&

$$

MTZ007-231700-
/O.EXT.KMSO.WW.Y.0022.000000T0000Z-210223T1700Z/
Butte/Blackfoot Region-
342 AM MST Tue Feb 23 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 10 AM MST THIS
MORNING...

* WHAT...Snow. Additional snow accumulations of up to one inch.
  Winds gusting as high as 35 mph.

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

* WHEN...Until 10 AM MST this morning.

* IMPACTS...Travel could be affected. Widespread blowing snow 
  could significantly reduce visibility. The cold wind chills as 
  low as 10 below zero could result in hypothermia if 
  precautions are not taken.

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.

&&

$$

MTZ006-231200-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T1200Z/
Bitterroot/Sapphire Mountains-
342 AM MST Tue Feb 23 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 AM MST EARLY
THIS MORNING...

* WHAT...Blowing snow. Winds gusting as high as 40 mph.

* WHERE...Bitterroot/Sapphire Mountains.

* WHEN...Until 5 AM MST early this morning.

* IMPACTS...Widespread blowing snow could significantly reduce 
  visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling, especially in open areas. 

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

&&

$$

IDZ005-006-231200-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T1200Z/
Northern Clearwater Mountains-Southern Clearwater Mountains-
242 AM PST Tue Feb 23 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST EARLY
THIS MORNING...

* WHAT...Blowing snow. Winds gusting as high as 35 mph.

* WHERE...Southern Clearwater Mountains and Northern Clearwater 
  Mountains.

* WHEN...Until 4 AM PST early this morning.

* IMPACTS...Areas of blowing snow could significantly reduce 
  visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling, especially in open areas. 

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

&&

$$

MTZ004-231200-
/O.CON.KMSO.WW.Y.0022.000000T0000Z-210223T1200Z/
Lower Clark Fork Region-
342 AM MST Tue Feb 23 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 AM MST EARLY
THIS MORNING ABOVE 4000 FEET...

* WHAT...Blowing snow above 4000 feet. Winds gusting as high as 
  35 mph.

* WHERE...Lower Clark Fork Region.

* WHEN...Until 5 AM MST early this morning.

* IMPACTS...Areas of blowing snow could significantly reduce 
  visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling, especially in open areas. 

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

&&

$$

Nearby

Winter Storm Warnings in Montana, 2021Every winter storm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.