Weather and Avalanche Log for Thu Apr 17, 2025
East wind Bridgers
East wind Bridgers
Toured out Deep Creek to Zeppo’s. Summer trail was largely melted out in the drainage. Despite warm temps and sticky, wet snow on E-S-W aspects, we still found about 4-10 inches of dry new snow over a MF crust on N aspects above 8500 feet. Snow in the Zeppo’s burn was holding up surprisingly well from the previous night’s freeze and was supportable through the afternoon. Large cornice formation on E aspects.
<p><span><span><span><span><span><span>The main avalanche concern today is </span></span></span></span></span></span><span><span><span><strong><span><span>wet loose avalanches</span></span></strong></span></span></span><span><span><span><span><span><span>. Temperatures did not drop to freezing in many areas overnight, so the snowpack will have a thin refrozen crust only an inch or two thick at most, if at all. Any crusts will melt quickly with sunshine and warm temperatures before clouds move in this afternoon, and it will be possible to trigger wet loose avalanches on steep slopes, especially those that receive direct sunshine. Natural avalanches might initiate near rock outcrops</span></span></span></span></span></span><span><span><span><strong><span><span> </span></span></strong></span></span></span><span><span><span><span><span><span>on steep, sunny slopes.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Without a good refreeze overnight there is potential for some larger wet loose avalanches. Even small avalanches will pose a threat where they can push you over cliffs, into rocks, or carry you down a long steep slope.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Assess the snow surface for wet snow instabilities, and plan to be off and out from under steep, sunny slopes before the sunshine further weakens the snow surface. Any rain this afternoon could also further weaken the snow surface. If you plan to travel on steep slopes, look for shadier slopes with a thicker refrozen crust or dry snow. Sinking past your ankle in wet snow, or seeing rollerballs, pinwheels or natural avalanches means it is time to find lower angle terrain or slopes with a colder, dry or refrozen snow surface.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Near Cooke City, you may encounter isolated unstable wind drifts on upper elevation slopes where snow surfaces remain soft and dry. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Also, be cautious on slopes below </span></span></span></span></span></span><span><span><span><strong><span><span>large overhanging cornices</span></span></strong></span></span></span><span><span><span><span><span><span> and give cornices space while traveling on ridgelines above, as they have become weak and easier to break from the heat and sunshine.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The main concern are wet snow avalanches on sun-exposed slopes where a few large avalanches are possible. Assess the snow surface for wet snow instabilities and isolated drifts, especially in steep consequential terrain. The avalanche danger is MODERATE.</span></span></span></span></span></span></p>
The Hyalite Canyon Road is closed to ALL MOTORIZED VEHICLES until May 16. This is a regular annual road closure to reduce road damage during the spring thaw. Bicycle and foot traffic are allowed.
Temps @0400 are 30-39 F
Yesterday's highs: 40-55 F,
We went through Flanders' Creek to the Flanders Weather Station to pull it for the season. We descended to the Grotto Falls TH via the Winter Dance Route. The surface snow got wet as the day progressed, but we saw no wet snow avalanche activity. I wouldn't be surprised if there was limited activity as the day progressed.
We went through Flanders' Creek to the Flanders Weather Station to pull it for the season. We descended to the Grotto Falls TH via the Winter Dance Route. The surface snow got wet as the day progressed, but we saw no wet snow avalanche activity. I wouldn't be surprised if there was limited activity as the day progressed.
Recent warm temperatures have almost universally affected snow surfaces. North-facing slopes above 9500' elevation remain dry, and pockets of dry snow exist at lower elevations on shaded slopes. South-facing slopes have cycled a few times, and the corn snow is coming in reasonably well.
There were no signs of dry snow instability.