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Castle Lake Basin

Location Name: 
Castle Lake
Castle Lake
Date and time of observation: 
Thu, 01/07/2021 - 11:30am
Observation made by: 
Red Flags:
Recent loading by new snow, wind, or rain

Location Map

96067 Mount Shasta , CA
United States
41° 13' 23.2176" N, 122° 23' 13.9056" W
California US

Snowpack Observations


Castle Lake tour, the first of winter with skis on the feet. Finally, a (barely) usable snowpack up there with an average snow depth of 30-35 inches. A mostly clear day with scattered, high clouds and light S/SW wind with moderate gusts, near and above treeline. Winds were strongest only on the highest ridges. New snow observed 1 to 3 inches. 

  • Observation Location: Castle Lake Basin
  • Elevation: 5,600 feet average
  • Date: 20210107
  • Time: 1000 to 1400 hours
  • Observer: N Meyers
  • Sky Conditions: Scattered (SCT) 
  • Current Precipitation: NO 
  • Air Temperature: 43 °F at 1300
  • Surface Penetration: Variable, .5 to 6 inches
  • Total Snow Depth (HS): 30-35 inches
  • 24-hour New Snow Depth (HN24): 1-3 inches
  • 24-hour New Snow Water Equivalent (HN24W): n/a
  • Wind Direction: S/SW
  • Wind Speed: Calm to light - Calm (C), 0 mi/hr | Light (L), 1-16 mi/hr, twigs in motion 
  • Column & Block Tests: n/a

Overall stable conditions at Castle Lake. I took a circuitous route to Heart Lake and continued up to Middle Peak, stomping around on many, small test slopes. Small wind slabs and cornices near ridge lines were easily triggered. Larger avalanches on a slope scale not likely. Wind slabs varied from 6 inches to 1 foot deep. Wind transport was minimal today, though previous wind was evident, a lot of westerlies moving snow toward NE/E/SE facing slopes. Windward NW/W/SW facing ridge lines are scoured to rock and ice. Where snow exists and exposed to wind, expect firm wind packed powder. Shady and/or protected slopes still hold soft powder.  Snow surfaces are generally smooth. For those sunny slopes, warm temps today (43° F at 1300) are likely to create a crust for tomorrow. The days are getting longer! Castle Lake is frozen and supportable. Right Peak has a good bit of Manzanita still showing. Middle Peak offers the best skiing. Left Peak is marginal at best. Definitely watch for rocks, bushes, stumps and other assorted goods. The road is plowed, bathrooms are open. 


  • Below treeline along the trail to Heart Lake
  • Middle Peak viewed from below treeline along the Heart Lake trail
  • 1-3 inches of new snow
  • Looking through to Right Peak, still pretty thin with a lot of manzo showing.
  • Some minor cracking along ridgelines, small cornices and wind slabs.
  • One of the bigger cracks along ridgeline, NE facing
  • Scoured rock and hard ice/old snow over exposed ridges, this ridge running north/south, winds have been primarily west.
  • Ah yes, the view of Mount Shasta from Castle Lake is an eye-brow raiser...every time.
  • Snow eroded by the wind looks like topographic lines on a map. This area just above Heart Lake. The bowl seen here faces easterly. The ascending ridgeline to the left leads to Middle Peak.

Weather Observations


Mostly clear, warm, high of 43°F at 1300 hours. Windy again on Mount Shasta itself, blowing out of the NW/W/SW, but not as much on the west side of I-5/Castle Area. A lenticular formed late in the day on the mountain, a classic sign of high wind. 


Cloud Cover: 
50% of the sky covered by clouds
Blowing Snow: 
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Above Freezing
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