Northern San Juan
SnowpackMatt Steen · Mar 20, 2013 · Northern San Juan
Weather
The weather deteriorated throughout the day. Strong winds prior to the frontal passage blew the strongest mid morning. Winds calmed as the cloud cover lowered and precipitation began to fall around noon. Overcast skies turned obscured by 12-1pm. Snow accumulations of 1-2 inches were observed above treeline by 4-5pm.
Snowpack
Variable snow surfaces above treeline consisted of supportable melt-freeze crust on southeast through southwest facing slopes and any other slopes that face the sun. Wind damage from the past week was evident as old petrified ski tracks were raised and sastrugi laden most of the terrain. Shadier north facing slopes held dry and faceted surface snow. Wind slabs were located on all terrain catchments, gullies and leeward of ridges. Recent winds built sizable cornices on many leeward ridges and sharp terrain features. Snow depths ranged from scoured exposed rocks to catchments with over 3 meters of snow. Several old loose wet avalanches from last week's warm temperatures were evident from steep rocky outcroppings above treeline. North facing slopes below treeline remained dry.