Fast moving and windy spring showers, dropping between 1 and 12+ inches of snow, have been affecting our area for the past two weeks. Between these quick hitters, warm temperatures and sunshine have been returning to heat the new snow and cause wet point releases near rocky areas and in steep terrain. The latest storm, on Sunday, left 1 to 3 inches of snow by Monday morning, primarily in the northern half of the forecast zone. Southwest winds associated with this storm created 6” to 18” thick wind slabs on steep, middle and upper elevation terrain. As showers exited the region early Monday, winds shifted to the north and northwest and temperatures rebounded to the 40s and even the 50s.
Temperatures are forecast to climb even higher on Wednesday. Slopes that did not rise to freezing levels yesterday may warm quickly. Rocky outcrops and trees will trap the heat and reflect in back down onto the snow, elevating the hazard of loose wet avalanches. Large pinwheels or ski penetration of boot top or greater are signs the snow is loosing strength and becoming unstable. Pay attention as you travel, notice conditions changing and trends. Perform your own stability tests and identify potentially hazardous terrain.
On Thursday, a cold front will push through our area bringing some snow showers, possibly some thunder and lightening, and most importantly wind. Winds will be strong and sustained starting Wednesday night and a High Wind Warning will be in effect through 8pm on Thursday. Though precipitation amounts are expected to be 1” or less, remember that wind can deposit new snow onto leeward slopes 3 to 5 times faster than it can fall from the sky. It’s this kind of rapid loading that creates wind slabs sensitive enough for you to trigger. In isolated areas where the most snow accumulates, just under ridge lines, convexities, and the side walls of gullies, you may find hollow-sounding wind slabs. Blowing snow and cornice formation will point to where the avalanche danger is increasing. Use these observations to make terrain choices that keep you out of harms way.
Early in the day Wednesday, and as winds cool the snow surface Thursday, firm, slide-for-life conditions will exist. Be careful of your exposure to a slip and fall on steep terrain where consequences are high.
