Avalanche Forecast

A weakening front should move over the Northwest Tuesday afternoon and night. This may cause some mostly light amounts of snow at Mt Hood but probably not as much as earlier expected.

The bigger story is the incoming atmospheric river on Wednesday. A warm front should south to north over the Olympics and Cascades Wednesday morning to afternoon. This should bring stormy wet weather with rising snow levels to Mt Hood starting Wednesday morning.

Mainly in the above treeline new wind slab of increasing density due to warming is very likely to form on lee slopes. Watch for firmer wind transported snow as the storm develops.

Also mainly in the above treeline new storm slab of increasing density is also very likely due to warming. Watch for snowfall that begins to accumulate at more than an inch an hour.

Rain in the below and possibly in the near tree line is also likely to create loose wet avalanche conditions. Watch for pinwheels and natural loose wet avalanches.

The rain where  heavy enough may activate previous layers and cause releases of previous wind slab layers or wet slab avalanches mainly in the near and below treeline.

Weather and Snowpack

Last week was wet and relatively mild with a series of active fronts transiting the region resulting in fluctuating freezing levels and periods of very strong winds (100+ mph gusts were not uncommon at the Mt Hood Meadows Cascade Express station).

The latter half of last week and the weekend featured more rain than snow at NWAC sites on Mt. Hood. For perspective, the averaged freezing level measured in March thus far has been 6600 feet at Salem; more akin to spring than late winter. 

A front Sunday and a cooler upper trough Monday brought some snow with 2 day storm totals of about 8-9 inches at Mt Hood ending Tuesday morning.

The mid and lower snow pack at Mt Hood should be a stable mix of crusts and layers of moist and rounded snow crystals.

Recent Observations

On Saturday the Mt. Hood Meadows pro-patrol reported wet snow up to about 6600 feet with a thin crust above and a well consolidated snowpack in their area. Following the cool down Saturday night, pockets of shallow new wind slab were seen above treeline by Sunday morning. 

On Monday there was about 5 inches of new snow and the Mt Hood Meadows pro-patrol reported a variety of conditions including isolated hard 12-18 inch wind slab on ENE slopes above treeline, wide spread sensitive 4-8 inch storm slab near treeline and small ski triggered loose wet avalanches below treeline on solar slopes.

The Mt Hood Meadows pro-patrol found that new and recent storm snow layers were less sensitive on Tuesday and that cooling had stabilized previous loose wet snow. Direct back country observations were not made on Tuesday but areas of 4-6 inch wind slab were still expected there.