Avalanche Forecast

Strong southwest flow carried a front across the Northwest on Tuesday. This should bring another couple feet of snow to Mt Hood by Wednesday morning with SW-W alpine winds and warming temperatures. Warming temperatures favor denser surface layers and the formation of wind and storm slab avalanches.

There has been a lot of snow the past few days and you cannot use the backcountry in your usual manner. Your usual slopes and routes may not be safe from avalanches. Plan to stay on low angle slopes away from avalanche terrain. There is more uncertainty than usual due to lack of backcountry field reports and the heavy snowfall. Avalanches are likely to be larger and run farther and be more dangerous than usual.

Deep wind slab should be watched for on all aspects but should be found mainly on NW to SE aspects due to recent SW to W winds. Watch for firmer wind transported snow on varied aspects especially in areas of complex terrain.

Most areas will have seen rapidly accumulating snowfall by Wednesday. Previous deep storm slab may not have stabilized. The warming trend will increase the likelihood of new storm slab layers.

We may have had enough snow for avalanches to step to or run on the Valentine's Day crust. Such avalanches would be large and very dangerous.

Cornices won't be listed as an avalanche problem but avoid travel on ridges near where cornices may have formed and avoid steep slopes below cornices that may fail at any time.

There has been enough snow lately that snow immersion accidents seem possible. Travel with a partner and keep them in sight at all times.

Weather and Snowpack

The most recent wet warm storm arrived on Valentines Day 2/14 and formed the uppermost very strong rain crust in our snowpack. 

Strong southwest flow carried a strong front across the Northwest on Friday evening. At Mt Hood this caused strong southwest alpine winds, heavy, moist, dense new snow above about 4000 ft and wet snow or rain below about 4000 ft.

NWAC stations at Mt Hood have had about 2 ft of snow in the past 5 days.

Recent Observations

NWAC observer Laura Green was out in Heather Canyon on Friday morning and found a reactive wind slab layer, giving moderate RP results at about 10 inches down in a pit on a NE slope at about 6450 ft. She was out later Friday on a tour in the East Fork area from 3500-5800 ft and found that the reactive wind slab layer was persisting there as well on a wind loaded slope about 10 inches down.

The Meadows patrol reported large wind sculpted features in the alpine Sunday with large hard wind slabs on exposed lee slopes. Extensive explosive control failed to release these hard slabs. These hard slabs are not likely to release by human trigger but should give caution to those traveling in steep exposed terrain.

A report via the NWAC Observations page for Sunday for the Tom/Dick/Harry Mountain area also indicates stubborn wind slab but with no avalanches.

The Meadows patrol on Tuesday reported strong winds and heavy snowfall but with limited avalanches. Upside down wind slab layers were building with lots of snowpack cracking and whoomping due to wind slab on ridges. Patrollers released 2 sensitive cornices remotely.