Overall the snowpack structure has improved, its strength has increased and its overall energy (reactivity) has decreased. Most new avalanche problems will be near the new/old snow interface and above. Warm temperatures have created crusts on sun exposed slopes which may act as bed surfaces with new precipitation.
With new snow and wind, human triggered storm and wind slab avalanches will be possible and may become likely near and above treeline. Natural avalanches may become possible as wind transports new precipitation above treeline. Another storm is expected Monday, March 11th and may keep avalanche hazard elevated.
Avoid convex pillows of wind-drifted snow, watch for new wind slab development and avoid overhanging cornices that have formed on leeward sides of ridgelines. Cornices on February 25th.
With cool and windy weather in the forecast, we have removed the potential for wet avalanche problems. But do watch for post storm rapid warming affecting new storm/wind slabs. We are getting close to the spring equinox and it is time to think about spring travel strategies.
No significant avalanches or unstable snow reported since February.
Near and Above Treeline:Watch for new wind slab development and growing cornices on leeward slopes. Expect to find wind scoured zones and hard icy snow above treeline - especially on south , southwest, west and northwest slopes. Crampons and ice axes will help prevent falls on steep icy slopes.
Sunshine after storms may destabilize new storm/wind slabs; primarily on southerly slopes.
Below Treeline:Tree wells are getting deep and tree well immersion suffocation is a real possibility. Coverage is good on most slopes above 9,500', with plenty of safer low angle (<30°) touring.
New storm slabs and wind slabs will be your primary problem near and above treeline this weekend and next week.
Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Avoid slabs and convex pillows of wind-drifted snow on lee and cross-loaded terrain features.
Forecast calls for new snow and southwest and west winds this weekend, so watch for northeast and easterly wind slab formation. Also, chutes and gullies on other aspects may cross load.
Keep an eye on the ASBTP weather station. Readings between 15 and 35 mph indicate the potential for snow transport and formation of wind slabs. Look for various links under the weather menu above. Note that this station may get rimed during storms and report erroneously.
Waiting at least 48 hours after wind events will decrease your chances of finding unstable storm/wind slabs.
Avoid standing on overhung cornices, as they may collapse unpredictably and send you downslope. They can sometimes break far back on flat ridge-top terrain. Sunny warm weather can naturally release cornices.
Logging work will start in the near future along the first 1/4 mile of Freidlein Prairie Road (FR-522). Loggers will plow that stretch of road and need gate access. This is part of the Chimney Springs thinning project.
Backcountry permits are required for travel in the Kachina Peaks Wilderness and available at local USFS locations, as well as, at the Agassiz Lodge on Saturday and Sunday 8:30 -11:30.
For information on uphill travel within the Arizona Snowbowl ski area, please refer to www.flagstaffuphill.com and https://www.snowbowl.ski/the-mountain/uphill-access/ for details. Access to the Kachina Peaks Wilderness is available from the lower lots at Snowbowl via the Humphreys Trail and Kachina Trail.
Weather update Thursday March 7th.
3" of dense snow fell today at treeline, with more snow expected this evening, with 20-25 mph south, southwest wind. 5" of dense snow and rime accumulated Saturday, March 2, at elevations above 10,000'. Warmer weather with moderate to strong southwest winds characterized Sunday - Wednesday, while Thursday and Friday have been a return to winter conditions and precipitation.
For Friday, March 8th, a storm system is expected to deliver 5 - 10" of snow near treeline. Expect continued cool, windy and unsettled weather through midweek, as another system enters the area on Monday, March 11th.
On Friday, March 8th, the Inner Basin SNOTEL site (Snowslide) reported a snow depth of 61” (155cm) at 9,730'. Arizona Snowbowl reported a settled base of 91” (231 cm) at 10,800'. So far this winter, 285" (719 cm) of snow has fallen at the mid-mountain study site. Since March 1st, SNOTEL temperatures have ranged between 19° F on March 6th, and 51° F also on March 6th. For the same period, ASBTP (11,555') reported temperatures between 15° F on March 4th, and 40° F on March 5th.