Manto nevoso

Avalanche Gulch

Christian JordanMount Shasta
Vedi sulla mappa
Foto dell’osservazione 1Foto dell’osservazione 2Foto dell’osservazione 3Foto dell’osservazione 4Foto dell’osservazione 5Foto dell’osservazione 6Foto dell’osservazione 7Foto dell’osservazione 8Foto dell’osservazione 9Foto dell’osservazione 10Foto dell’osservazione 11Foto dell’osservazione 12Foto dell’osservazione 13

Quick report

Cracking
isolated

The April 1st storm provided a welcome refresh to most snow surfaces in Avalanche Gulch - new snow totals ranged from three inches to over a foot in the most heavily wind-drifted locations. Leeeward terrain features held shallow, reactive wind slabs near and below treeline. Northwest winds blew snow across ridgelines on the upper mountain throughout the duration of the tour. No wet snow instabilities were observed. 

Snow surfaces were variable in Avalanche Gulch (see annotated photo) - everything from soft snow to windboard (breakable) to wind-scour (firm and icy). The wind-scoured surfaces were especially slick - crampons were mandatory for traction. It may take a few days for the wind-drifted snow to transition to supportable melt-freeze crusts. Be prepared for challenging conditions in the coming days, including breakable crusts. Shallowly buried obstacles abound, especially below treeline. 

Isolated cracking in wind-drifted features on density changes within the new snow near and below treeline.

Weather

Cloud Cover
few
Wind Loading
light
Recent Snowfall
8
Snow Avail For Transport
small smounts

A cold April day after the storm. Strong to extreme northwest winds blew snow across ridgelines above 9,000 feet as we began at 9am. By mid-morning, wind speeds decreased significantly below Helen Lake (10,400 feet) and shifted to a more southerly direction. Mostly clear skies with periods of obscured visibility due to fog.

Snowpack

Shifting wind directions during and after the storm made for a challenging assessment of the aspects most likely to harbor slabs. 

Cold temperatures limited wet loose concerns during the outing. However, the surface snow below treeline became moist to wet upon our exit around 1245pm.