Northern San Juan
AvalancheKrista Beyer · Apr 9, 2024 · Northern San Juan
Weather
Temperatures around 11,000 feet climbed to 39 degrees at 3:00pm. Temperatures around 12,300ft remained below freezing. Winds measured between 5 and 10 degrees out of the north. Temperatures the previous couple nights hit a low of 10 degrees around 11,000 ft and below freezing temps were maintained for the duration of 4/8. This weather is the baseline freeze for a series of increasingly warmer days with increasingly weaker freezes. Thursday and Friday are setting up to be days to watch for changing conditions, particularly at lower elevations.
Snowpack
2-3 inches of light, rapidly warming snow sits on a variety of firm surfaces. Southerly slopes carry a firm melt freeze crust at the interface, while northerly and easterly slopes above treeline carry a firm wind effected interface from th 4/5-4/6 wind event. Near and below treeline north and northeast slopes, there is eveidence of wind effected snow, but the interface is softer and observed wind transport is limited to unreactive soft slabs. We dug on a SE and NE slope at 11,700 ft. Height of snow on SE was 140cm. Water has moved through the snowpack at this elevation during previous warming cycles. The snowpack can be described as layers of melt-freeze crusts and clustered melt forms. The basal layer was wet and comprised 2mm rounded grains. I identified 3 layers of ice within the snowpack Ice may correspond with periods of pooling as water has moved through the pack. Pit tests resulted in non-notable results. Moderate broken failures in the top 20cm of the snowpack above and below melt-freeze crusts. The NE pit was dug at the same elevation. Height of snow local to the slope was around 280cm and is a location that sees drifting. I dug to the March 3rd dust layer which has been rleiebly knife-hard in recent northerly pits. This snowpack can be described as generally strong, deep, and right-side-up. A crust layer sits beneath new snow and a knife-hard layer is stacked between a finger and a pencil-hard slab. The only test results observed where in the new snow (CT12 (BRK) and at the new/old interface (CT14 (RP)).
Avalanche
A handfull of small loose activity isolated to the most recent snow from 4/8 and on steep slopes out of rocky areas. Dry Loose on Northerly aspects, Wet Loose on easterly aspects. Southerly aspects were suprisingly quiet prior to 2 pm.