Yellowstone Up Close and Personal Logo © Copyright Page Makers, LLC
Yellowstone Up Close and Personal Grizzly Logo © Copyright Page Makers, LLC

Daily Winter Weather Report

Date: Tuesday - 20 December 2011

Station Max Temp Min Temp Pres Temp New Snow Depth Sky Present Conditions
Canyon 36 -12 -4 0 14 BC Calm
East Entrance 42 0 4 0 16 OC Calm
Grant Village 28 -4 -1 T 21 OC Calm / Fog
Lake 32 0 1 0 15 SC Calm

Madison 21 -4 0 0 11 OC Calm

Old Faithful 36 -5 2 0 13 C Calm

Snake River 33 0 4 0 21 SC Calm
Soda Butte

Thumb Divide

West Entrance 35 5 14 0 13 - Calm / Fog
T=Trace / BC=Broken Clouds / OC=Overcast / SC=Scattered Clouds
All Temperatures are in °F ~ All Snow Depths are in Inches

* * * Road Conditions * * *
Road Section Status Conditions Public Access / Info
Gardiner to Mammoth YR Good STA
Mammoth to Tower YR Good STA
Tower to NE Entrance YR Good STA
Beartooth Highway CLOSED * CLOSED * CLOSED *
Firehole Canyon Drive CLOSED CLOSED CLOSED
Grant to South Entrance Open   Rubber tracked oversnow concession vehicles
Junction to Chief Joseph Hwy CLOSED * CLOSED * CLOSED *
Lake to East Entrance CLOSED CLOSED CLOSED
Madison to Old Faithful Open   Rubber tracked oversnow concession vehicles
Madison to West Yellowstone Open   Rubber tracked oversnow concession vehicles
Mammoth to Norris Open   Rubber tracked oversnow concession vehicles
Norris to Canyon Open   Rubber tracked oversnow concession vehicles
Norris to Madison Open   Rubber tracked oversnow concession vehicles
Old Faithful to Grant Open   Rubber tracked oversnow concession vehicles
Tower to Canyon CLOSED * CLOSED * CLOSED *

YR=Year Round / NR=No Restrictions / STA=Snow Tires Advised / STR=Snow Tires Required


# Poor road conditions - bare spots and melting snow - Restricted to Snowcoaches Only.

The park service plowing schedule for roads for the spring season.

******** FOR CURRENT ROAD INFORMATION PLEASE CALL 307-344-2117 ********


Yellowstone Forecast on December 20, 2011
by the National Weather Service Riverton, WY

Today: Occasional flurries after 11:00 am. Patchy freezing fog before 11:00 am. Increasing clouds, with a high near 26°F. Wind chill values as low as -15°F.

Tonight: A 50 percent chance of snow. Mostly cloudy, with a low around 7°F. Wind chill values as low as -5°F. New snow accumulation of 1 to 3 inches possible.

Wednesday: Snow likely. Cloudy, with a high near 18°F and a low around -9°F. Night time Wind chill values as low as -25°F. Chance of precipitation is 70%. New daytime snow accumulation of 1 to 3 inches possible, with less than half an inch additional overnight.

Thursday: Occasional flurries before 11:00 am. Mostly sunny, with a high near 14°F and a low around -11°F.

Friday: Mostly sunny, windy, with a high near 17°F and a low around -3°F. Breezy, with a southwest wind 6 to 9 mph increasing to between 18 and 21 mph. Winds could gust as high as 31 mph.

Saturday: A 20 percent chance of snow showers. Partly sunny, with a high near 19°F and a low around 0°F.

Snowflake Hazardous Weather Snowflake Gibbon Falls Forecast Snowflake Mammoth Forecast Snowflake Midway Forecast Snowflake Norris Forecast Snowflake Old Faithful Forecast Snowflake

* * * Snow Depth Totals as reported at SNOTELs * * *
Station Depth (inches) Station Depth (inches)
Black Bear 34 Parker Peak 32
Blackwater 36 Snake River Station 19
Canyon 17 Sylvan Lake 25
Evening Star 33 Sylvan Road 17
Fisher Creek 39 Thumb Divide 20
Grassy Lake 26 Two Ocean Plateau 41
Lewis Lake Divide 26 West Yellowstone 14
Madison Plateau 23 Whiskey Creek 19
Northeast Entrance 10 Wolverine 13

Avalanche Information
from the Gallatin National Forest Avalanche Center - December 20, 2011 - this report is by Doug Chabot. This advisory does not apply to operating ski areas.

Mountain Weather

Mountain temperatures are in the high teens Fahrenheit this morning with west to north winds at 15-30 mph and gusts hitting 40 mph. Today will start sunny, but clouds will increase later this afternoon as a cold front brings snowfall late tonight. Steady 20-40 mph winds will blow ahead of the front with nighttime temperatures dropping into the low teens Fahrenheit. By morning I'm expecting 3 to 4 inches of snow with storm totals of 6 to 8 inches by Wednesday night.

Snowpack and Avalanche Discussion:

The Bridger and Madison Ranges, the southern Gallatin Range and the Lionhead area near West Yellowstone:

With the exception of the northern Gallatin Range and mountains around Cooke City our mountain snowpack is weak, thin and not impressive. According to the NRCS we are at 65% of normal. That's giving winter a below average grade of "D" and Mother Nature doesn't grade on a curve. Weak snow is defined as unsupportable, unconsolidated, and faceted. Every time I step out of my skis or off my snowmobile I sink to the ground confirming its presence. This snowpack will have a difficult time supporting future snows.

My partner and I skied into Beehive Basin in the northern Madison Range on Sunday and found two feet (at most) of sugary, weak snow. In order to have an avalanche we need 4 things: a steep slope, a weak layer, a slab of snow sitting on that layer and a trigger. In Beehive, as in many parts of our advisory area, the missing ingredient is the slab. On slopes with deeper snowpacks this slab exists, which is why the ski patrols were able to release a few avalanches this past weekend with explosives.

For today, the avalanche danger is a function of depth. On slopes where the snowpack is greater than two feet deep, mainly on wind-loaded slopes, a slab exists and the Avalanche Danger is rated MODERATE. On slopes with less than two feet of snow the Avalanche Danger is rated LOW.

The northern Gallatin Range and mountains around Cooke City:

Mark and Eric spent the weekend digging snowpits around Cooke City. This trip was on the heels of Mark's tour up Flanders drainage in the northern Gallatin Range. Although miles apart, there were some similarities. Three or more feet of snow was measured in both areas, plus faceted, weaker snow was found near the ground. Stability tests indicated this layer is slowly strengthening and they concluded it would take a large storm to get it to avalanche; however, buried facets are never to be fully trusted. Occasionally the test columns propagated fractures. These results indicate variability within the snowpack as well as the possibility of triggering a slide. A natural avalanche outside Cooke City on Sunday is further evidence of this possibility.

For today the Avalanche Danger is rated MODERATE on all slopes steeper than 35 degrees. All other slopes have a LOW Avalanche Danger.

The next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations, drop us a line at or call us at: 406-587-6984.


1. We've recently uploaded more photos and snowpits to our web site, more than what are linked in the advisory.

2. We're creating a series of "How To…" stability test videos. So far we've got clips on performing a CT and ECT. There are located under Stability Tests on the Resources page.

Information provided by Doug Chabot, Mark Staples, and Eric Knoff from the Gallatin National Forest Avalanche Center. For Photos and Videos, please visit the Avalanche Centers Website!

If you have any snowpack or avalanche observations, drop them a line at or call: 406-587-6984.

For detailed Avalanche Terms utilized here, please see the Avalanche Glossary.

Avalanche Danger Scale

Back to the Yellowstone Daily Winter Reports or the Yellowstone Weather Page

Information provided by Yellowstone National Park, National Weather Service and Gallatin National Forest Avalanche Center

Yellowstone National Park by Page Makers, LLC © Copyright All Rights Reserved
I n d e x
Accessibility Earthquakes Maps Video Page
Address Email Newspaper Visitor Centers
Adult Programs Entrances Old Faithful Live WebCam Visitor Stats
Amphibians Entrance Fees Pets Volcano Observatory
Animals Fall Closure Phone Numbers Waterfalls
Backcountry Fish Picnic Areas Weather
Bear Management Fishing Fees Ranger Led Activities WebCams
Bear Sightings Fishing Regulations Reptiles Wildflowers
Biking Getting Here Reunions Winter Closing
Boating Hiking Rivers, Creeks & Streams Winter Opening
Books History Roads Winter Weather Reports
Butterflies Junior Ranger Program Schedule Wolf Project
Camping Lakes Search Page Wolf Sightings
Campground Maps Location Spring Opening Wolverine Help
Challenges Lodging Star Talks Yellowstone ~ the Name
Chat Page Lynx Help Trip Planner pdf Young Scientist
Clinics / Medical Mammal List Trip Reports Youth Conservation Corps
Not all who wander are lost by John Ronald Reuel Tolkien © Page Makers, LLC
Yellowstone National Park WebCams
Old Faithful Live All Old Faithful Old Faithful Static Old Faithful VC North Entrance Mt Washburn Mammoth YVO WebCam

Rexburg Idaho WebCams
  Rexburg, Idaho WebCams  

Yellowstone Area Highway WebCams
Alpine Junction Hwy 89 (South) Monida Pass I-15 (North)
Bozeman Pass I-90 (North) Osborne Bridge Hwy 20 (West)
Henry's Lake North Hwy 20 (West) Raynolds Pass MT 87 (North or West)
Henry's Lake South Hwy 20 (West) Teton Pass WY 22 (South)
(North) = Closest Entrance to Yellowstone National Park.

State Road Reports
Idaho Utah
Montana Wyoming

Entrance Cities and Gateway Towns
Gardiner, Montana Silver Gate, Montana West Yellowstone, Montana Cooke City, Montana
Livingston, Montana Cody, Wyoming Jackson Hole, Wyoming Yellowstone National Park

The Great Outdoors Net Great Outdoor Recreational Places
Gardiner, Montana World Humanity

Contact Us

by John William Uhler

Back to: Yellowstone Up Close and Personal

Copyright © 1995 - 2014 Page Makers, LLC and Yellowstone Media ~ All Rights Reserved