Bollettino valanghe

Mt Hood

Jan 17 – 18, 2015Northwest Avalanche Center
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Archiviato · scaduto 12 years ago

Pericolo valanghe

Mon
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato

In sintesi

Sunday should be fairly stormy day at Mt Hood. New storm and wind slab layers are likely.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1
  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1

Detailed Forecast

A wet cold front will cross the Northwest Saturday night. Snow levels will be highest on Saturday night. A good period of southwest-west flow, moderate to heavy orographic snow showers, and cooling with lowering snow levels should be seen on Sunday. New snow by the end of the day Sunday at Mt Hood should vary a lot from lower to higher elevations with 10 inches or more at higher elevations.

Building storm slab is likely mainly near and above treeline on Sunday. Watch for cracking and releases on steep sheltered slopes where snowfall exceeds an inch an hour for more than a few hours.

Building wind slab is also likely mainly near and above treeline on Sunday. Watch for firmer wind transported snow on lee slopes.

The cooling should cause some good snow conditions on other slopes. Don't let powder starvation change plans to stick to safe slopes on Sunday. It is always a good plan to give new snow layers a day to stabilize before venturing to steeper slopes after a storm.

Snowpack Discussion

A front late Thursday was followed by showers Friday. At NWAC stations at Mt Hood  this gave about 4-8 inches of storm snow.

While the Mt Hood Meadows patrol on Friday morning at 6600 feet reported a weak bond of new storm snow to the old crust, subsequent observations in the afternoon indicated there were very few avalanche releases with explosive control. Shallow storm snow, rough underlying crust surfaces and non-uniformed loading were some contributing factors.

The underlying mid and lower snowpack at Mt Hood should mainly consist of melt-freeze crusts and stabilized rounded grain layers. This is due in great part to the warm and dry period from about 6-15 January and previous similar periods so far this winter. Persistent weak layers are not expected at Mt Hood.

The overall snowpack remains well below normal for this time of year and some windward or southerly aspects may have little if any snow cover.

Regioni coperte