Avalanche Forecast

Decreasing light to moderate rain and snow will become showery by Wednesday afternoon, however Tuesday and Tuesday's higher density storm snow and wind loading will have elevated the avalanche danger significantly.

A loose wet avalanche problem will develop during the afternoon hours as snowfall changes to rain at lower elevations. Small natural loose wet avalanches are likely on steep, unsupported, or convex terrain up to about 5000 ft, where enough recent snowfall has accumulated. Be aware of the consequences of a small loose avalanche, particularly where cliffs, rocks, gullies, and creeks magnify the consequences.

Storm slabs developing in many areas Tuesday afternoon will build to 1-2' in the Mt Hood area by Wednesday morning. Storm slabs will remain touchy Wednesday, with the potential to entrain the deeper lower density snow from the past week that exists in all areas, allowing these slabs to run farther and become larger than you expect. Stick to lower-angle terrain that is well-supported or heavily terrain anchored. Step back your travel plans and recognize that this new snow needs significant time to settle.

Strong winds are transporting the new snow, particularly near and above treeline. These will continue to build very touchy and large wind slabs near and above treeline on a variety of aspects. New or recent wind slabs may also produce large avalanches, entraining significant amounts of deeper loose dry snow. Above treeline terrain is not recommended on Wednesday. Elsewhere, avoid wind-loaded terrain and consider any aspect to be fair game for wind slabs on Wednesday. Also avoid avalanche paths with higher elevation start zones.

The avalanche danger will lower slightly during the day on Wednesday, but the potential for triggering a large avalanche remains near and below treeline. Above treeline terrain, where high winds have created very sensitive and deep wind slabs, backcountry travel is not recommended. Recent storm and wind slabs require time to heal, so be patient and match your terrain selection appropriately and avoid avalanche run and stop zones. 

6-12" of new storm snow has fallen on Tuesday at Mt. Hood stations below treeline with 1" of snow water at Mt Hood Meadows and 1.5" of snow water at Timberline. This has created a thick and dense storm slab along with sizeable wind slabs.

An active weather pattern from 1/18 onwards and continuing through Monday has deposited 1.5-2.5' of snow falling at temperatures generally in the upper 20's over the most recent 1/17 crust. Observations indicate the recent snow bonded well to the crust.

Poor visibility and dangerous travel conditions have made observations in above treeline terrain difficult to obtain. A high degree of uncertainty exists regarding the extent and sensitivity of wind slabs above treeline.

Below treeline, lower snowdepths have limited the development of widespread avalanche problems. 

Observations

On Tuesday Mt. Hood Meadows Pro Patrol reported rain to 3800'. Wind slabs were building near and above treeline on top of lower-density snow received over the weekend. The slabs were sensitive to skier triggering down to the crusts from 1/16 or within the storm snow. Slab depth was variable. Winds were moderate near and below treeline and strong above treeline.

On Monday morning, Mt Hood Meadows Pro Patrol reported 6" of new snow at 5300' and 13" at the top of their terrain that fell on Sunday night. Wind slabs up to 1' were found into near treeline terrain, with the larger releases triggered by explosives.