The surface hoar monsters lurk in dark and quiet terrain

We chased the biggest storm totals to the Swan Range and found dangerous avalanche conditions resulting from buried surface hoar below the 16" to 24" of storm snow.

• On wind protected, shady aspects at mid elevations, we produced numerous shooting cracks, collapses, slab releases on test slopes, and saw recent natural avalanches. These were consistently failing on the 2/23 surface hoar layer, 16" to 24" deep. 
• Test slopes in previously wind affected terrain or previously sun cooked aspects did not produce results; the surface hoar was not present in hand pits at these locations. 
• We also triggered and observed small natural sluffs that ran today.
• The sun came out this afternoon and was moistening the snow at lower elevations as we were leaving  at 2:30 pm. There were some rollerballs and pinwheels.
• Given the numerous red flags, we kept our terrain choices simple: short, inconsequential pitches and slope angles less than 35 degrees.