Special Avalanche Advisory Issued: Sunday, February 17, 2019 at 6:00 AM
Expires: Monday, February 18, 2019 at 9:00 AM

A strong storm on Thursday night brought 1 to 2 feet of dense snow with strong winds to the mountains. Avalanche conditions remain dangerous especially in the Central and Southern Mountains. You can trigger avalanches that break in the new and wind drifted snow that will be large enough to bury or kill you. You may even be able to trigger very large very dangerous avalanches that break deeper in the snowpack. If you trigger one of these deeper avalanches it will most likely be inescapable. Consult the Zone Summary for the areas you are planning to travel for specific information and travel advice. Make sure you carry an avalanche transceiver, shovel and probe and know how to use all of your gear. You can always limit the chance of being caught in a dangerous avalanche by sticking to lower angle terrain without steeper connected avalanche slopes above you.

  • Backcountry Avalanche Forecast
  • Forecast Discussion
  • Observations & Weather Data

Sun, Feb 17, 2019 at 7:27 AM
Issued by: Mike Cooperstein

Today

 

Tomorrow

Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.   Moderate (2) Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully.
Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.   Moderate (2) Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully.
Moderate (2) Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully.   Moderate (2) Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully.
  Danger Scale

  • No Rating
  • 1
    Low
  • 2
    Moderate
  • 3
    Considerable
  • 4
    High
  • 5
    Extreme

Summary

Dangerous avalanche conditions exist today particularly in near and above treeline areas. You can easily trigger avalanches in the new and freshly drifted snow. If you trigger an avalanche it can break into deeper weak layers resulting in a very large possibly deadly avalanche. You can trigger avalanche remotely, from the bottom of a slope, and from a distance. Avalanches can break in surprising ways. Wind have been changing direction during the storm period. You may find wind drifts in unusual places. If you trigger an avalanche in a wind drifted area it will be larger and more dangerous. Avoid travel on and under slopes steeper than about 30 degrees in near and above treeline areas where you find more than about 10 inches of new or wind-drifted snow. 

 

Avalanche Problem

 
problem icon
N
S
E
W
NW
NE
SE
SW
Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
Likely
Possible
Unlikely
Historic
Very Large
Large
Small
Avalanche Character Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Wind Slab avalanches release naturally during wind events and can be triggered for up to a week after a wind event. They form in lee and cross-loaded terrain features. Avoid them by sticking to wind sheltered or wind scoured areas.

Avalanche Problem

 
problem icon
N
S
E
W
NW
NE
SE
SW
Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
Likely
Possible
Unlikely
Historic
Very Large
Large
Small
Avalanche Character Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Persistent Slab avalanches can be triggered days to weeks after the last storm. They often propagate across and beyond terrain features that would otherwise confine Wind and Storm Slab avalanches. In some cases they can be triggered remotely, from low-angle terrain or adjacent slopes. Give yourself a wide safety buffer to address the uncertainty.

Avalanche Problem

 
problem icon
N
S
E
W
NW
NE
SE
SW
Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
Likely
Possible
Unlikely
Historic
Very Large
Large
Small
Avalanche Character Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Loose Wet avalanches occur when water is running through the snowpack, and release at or below the trigger point. Avoid very steep slopes and terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.

Weather Forecast for 11,000ft Issued Sun, Feb 17, 2019 at 12:27 PM by Mike Cooperstein Statewide Weather Forecast
  Sunday Night Monday Monday Night
Temperature (ºF) -5 to 0 5 to 10 -4 to 1
Wind Speed (mph) 8 to 18 10 to 20 10 to 20
Wind Direction S SSW S
Sky Cover Overcast Overcast Overcast
Snow (in) 3 to 5 3 to 5 6 to 12

Archived Forecasts

  • Select Forecast: Valid

Sun, Feb 17, 2019 at 7:57 AM
Issued by: Mike Cooperstein Statewide Weather Forecast  

Strong winds since Thursday's storm have moved all available snow to lee-facing slopes. North through east to south-facing slopes near and above treeline are the most dangerous today and should be avoided. We have also received reports of dangerous wind-slabs in open below treeline meadows, so do not blindly jump onto steep slopes in below treeline areas either. 

It may be a few days before we know the extent of the avalanche cycle that this unusual snow event triggered, but from what we can tell it seems like most avalanches broke within or just underneath the storm snow. These avalanches were two to three feet deep and were large and dangerous. As you would expect with a storm with this high of precipitation intensity, we have also received reports of dangerous avalanches breaking near the ground or on mid- to upper-pack layers such as near-surface facets and facets around crust. The crust-facet combos are more prevalent on sunny slopes and could be buried 3 to 5 feet deep at this point. If you trigger an avalanche on one of these persistent weak layers it will most likely be inescapable.

Snow continues today with up to 10 inches possible by Monday afternoon. The new snow will be low density., and will most likely not add enough weight to trigger another natural avalanche cycle. Slopes that continue to receive wind-drifted snow will continue to be dangerous and loading will have to stop before these slopes become more stable.

The bottom line is that this was a very large load in a short period. The general trend of the snowpack is good on a seasonal scale as we are building a deeper and stronger snowpack. For today, very dangerous conditions exist and the snowpack needs some time to adjust to this rapid load.

If you are traveling in the Sangre de Cristo Mountains, these mountains received about a foot of snow with strong winds. Although this a lot less snow than the San Juan Mountains, the snowpack is much, much weaker and avalanches on deeper layers or the ground are more likely. This problem in the Sangre de Cristo zone will be slow to change.


  • CAIC forecasters traveled in the alpine to evaluate sensitivity in persistent weak layers on northwest aspects and extent of recent wind-drifting from strong southwest winds. They found stiff, stubborn slabs sitting above a soft collapsible layer formed during recent dry weather and large facets and depth hoar persisting above the ground.
  • Weak surfaces and weak snow on the ground in the North san Juan zone. As the new snow begins to accumulate on Sunday you may be able to trigger dangerous avalanches just below the new and wind-blown snow or even avalanches that break to the ground. February 2, 2019

See more photos & videos

Five Day Trend

Thursday

Friday

Saturday

Today

Tomorrow

danger icon danger icon danger icon danger icon danger icon
danger icon danger icon danger icon danger icon danger icon
danger icon danger icon danger icon danger icon danger icon

  • No Rating
  • 1
    Low
  • 2
    Moderate
  • 3
    Considerable
  • 4
    High
  • 5
    Extreme
Avalanche Observations
No relevant backcountry observations found for this forecast

See All Avalanche Observations

Field Reports
Report Date Observer Snowpack Obs Avalanches Media

See All Field Reports

Weather Observations
Station Date Time Temperature Relative Humidity Wind Speed Wind Direction Max Gust 24 Hr Snow
La Veta Pass (160w278) Sun Feb 17 6:30 PM 13 41 - 130 1 1.0

See All Weather Observations