Avalanche Forecast

Light to moderate snow showers at cool temperatures are expected overnight and early Sunday before tapering through the day. Winds should be light, except light to moderate in the alpine.

Only light accumulations of new snow are expected and with cold temperatures and light winds this should not affect the current avalanche danger significantly. The avalanche danger should gradually decrease on Sunday. However, cold temperatures may help maintain older wind slab and isolated storm slab layers.

Heightened avalanche conditions are expected on specific terrain features, such as steep wind loaded slopes and steep unsupported slopes, or cross loaded features. Avalanche conditions are expected to gradually improve, however, evaluate snow and terrain carefully and avoid features or slopes of concern Sunday.

Recent moderate to strong S-SW winds will make wind slab most likely on northwest to southeast slopes, but keep an eye out on all aspects in areas of more complex terrain. Watch for firmer wind transported snow from Friday and possible deeper wind transported layers. Older wind slabs may be masked by shallow fresh snow.

Cornices won't be listed as an avalanche problem in this area, but avoid travel on ridges, where recent cornices may have formed and avoid slopes below cornices.

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. 

A stronger than forecast storm late Monday through Tuesday deposited 2 - 2.5 ft of snow by Tuesday evening. The heavy snowfall arrived with very strong westerly alpine winds which gradually decreased on Wednesday.

Thursday began mostly sunny but increasing clouds were seen in the afternoon. SW winds above treeline increased and become were very strong Thursday afternoon, with a gust above 100 mph at 6 PM recorded at the Cascade Express weather station at Mt. Hood Meadows.

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. Cooling by early Saturday deposited about 6-8 inches of new snow. Alpine winds remained very strong early Saturday with many hours of gusts over 100 mph!

Recent Observations

Several contacts were made with the Mt Hood Meadows patrol through the day Tuesday and they reported widespread natural and triggered wind and storm slabs especially near and above treeline. Avalanches were occurring even on relatively low angled terrain. Low visibility limited additional observations but by Tuesday afternoon large hard wind slabs were developing above treeline and several sympathetic avalanches were triggered. The recent relatively stable snowpack had quickly turned into very dangerous avalanche conditions.

By Wednesday conditions had improved and the Mt Hood Meadows patrol reported sunny but windy conditions with windward slopes getting scoured and local size-able wind slab building on lee slopes. The lower mountain was showing signs of spring with rollerballs and small triggered loose wet avalanches.

OnThursday NWAC observer Laura Green reported that a sun crust had formed on solar slopes. She passed along that several natural hard wind slab avalanches had occurred in White River Canyon above treeline on E-NE aspects with crown depths up to several feet. She also saw a 2-4 ft crown in Newton Canyon on a NE slope at about 6400 ft. These hard slab wind avalanches likely occurred on Wednesday.

Laura was out in Heather Canyon on Friday morning and found a reactive wind slab layer giving moderate RP results at about 25-28 cm 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 25 cm down. Loose wet snow and pinwheels were seen below about 4000 ft.