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

Wed, May 1, 2019 at 6:29 AM
Issued by: Brian Lazar

Today

 

Tomorrow

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.   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.
  Danger Scale

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

Summary

You can trigger an avalanche large enough to bury you today. The North San Juan zone received about a foot of new snow in the last couple days. You can trigger slabs in the storm snow up to 3 feet deep, and there are sensitive cornices along ridgelines. Slabs are thickest, stiffest, and most dangerous on north to east to southeast facing slopes that are received the most wind-drifted snow. Look for cracking in the new snow as a sign of slab formation. Safer riding options exist on slopes less than about 35 degrees. 

The storm snow could start to shed off the old surface as temperatures warm this afternoon. Look for wet cohesionless snow at lower elevations. Roller balls, and slushy surface conditions more than about 6 inches deep are signs that wet avalanche activity is imminent.   This concern will increase the avalanche danger on Thursday with warmer temperatures and more sunshine. 

This is the last zone forecast of the 2018-19 season. We will issue daily regional forecasts by 3:00 PM through May 31

 

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


Storm Slab avalanches release naturally during snow storms and can be triggered for a few days after a storm. They often release at or below the trigger point. They exist throughout the terrain. Avoid them by waiting for the storm snow to stabilize.

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.

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 Wed, May 1, 2019 at 4:01 AM by Brian Lazar Statewide Weather Forecast
  Wednesday Wednesday Night Thursday
Temperature (ºF) 32 to 37 17 to 22 37 to 42
Wind Speed (mph) 10 to 20 5 to 15 7 to 17
Wind Direction WSW SW WSW
Sky Cover Mostly Cloudy Partly Cloudy Mostly Cloudy
Snow (in) 1 to 3 0 0

Archived Forecasts

  • Select Forecast: Valid

Wed, May 1, 2019 at 6:45 AM
Issued by: Brian Lazar Statewide Weather Forecast  

That was a nice little storm to close out April. The Southern Mountains generally picked up around a foot of dense new snow in the last couple days, with snow water equivalent of around 1 to 2 inches. Wolf Creek picked up 2.7 inches of water with Spud Mountain and Vallecito coming in second with 2.3 inches. 

The new snow is deep enough in itself to create Storm Slab avalanches. Slopes that received more than 8 inches of snow are the most likely areas to trigger one of these fresh slabs. Strong southwest winds drifted snow into thicker and stiffer slabs near and above treeline. Drifts will be more widespread on slopes facing north to east through south and avalanches on theses slopes will be larger and more dangerous. Look for warning signs like surface cracks and avoid lens-shaped pillows or textured snow to reduce your avalanche risk.

There is a lot of new storm snow sitting out there, and it's bound to shed off the old snow surface with wet avalanches. This could start this afternoon at lower elevations. It's the first day of May, and the sun will have a significant impact on the new snow. It won’t take much sun for the new snow to start sluffing down-slope. With snow depths around a foot or more, there will be enough new snow for sluffs to entrain additional snow creating larger piles at the bottoms of slopes or in terrain traps.

This is the last day of 10-zone forecasts for the season.  We will continue to issue daily regiona (Northern, Central, and Southern Mountains) forecasts and danger ratings through May. Get daily updates at our website colorado.gov/avalanche and please continue to send us your observations! 


  • CAIC forecasters provide an end of the season snowpack update for the San Juan Mountains. The CAIC will issue daily weather and regional avalanche forecast through May 31. Please continue to submit observations to our website at colorado.gov/avalanche.
  • Large, overhanging cornices dot the landscape. Be mindful of these monsters as we get deeper into spring. Some are starting to crack along ridge lines and can break farther back than you might expect. Give them a wide berth during periods of prolonged above freezing temperatures. (full)

See more photos & videos

Five Day Trend

Sunday

Monday

Tuesday

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
Report Date # Elevation Aspect Type Trigger SizeR SizeD
View Sat May 25 - >TL NE SS AS R1 D1
View Fri May 24 - - W SS N R3 D2.5

See All Avalanche Observations

Field Reports
Report Date Observer Snowpack Obs Avalanches Media
View Sat May 25 Chris Price No Yes (1) Yes (1)
View Fri May 24 Amy Pertuz No Yes (1) Yes (3)

See All Field Reports

Weather Observations
Station Date Time Temperature Relative Humidity Wind Speed Wind Direction Max Gust 24 Hr Snow
Putney Sun May 26 9:00 PM 28 89 18 173 23 1.0
Swamp Angel Sun May 26 9:00 PM 29 94 2 243 8 0.1
El Diente Peak Sun May 26 8:00 PM - - 2 109 - -

See All Weather Observations