Avalanche Forecast

Issued: Mar 6th, 2023 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs.

Avalanche Canada jminifie, Avalanche Canada

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Storm slabs will continue to develop and remain triggerable this week, especially in wind loaded terrain features and where recent snow sits over a slippery crust. Take a conservative approach, ease into terrain cautiously and watch for signs of instability.

Summary

Confidence

Moderate

Avalanche Summary

Small (size 1) natural and explosives triggered avalanches were reported from the Mt Washington area on Monday.

If you head into the backcountry please consider sharing your observations on the Mountain Information Network!

Snowpack Summary

New snow continues to accumulate. 30-60 cm of recent snow sits in an upside-down configuration, with warmer, heavier snow on top of colder, lower density snow. At upper elevations, the recent snow has likely seen some redistribution into lee terrain features by moderate wind.

A thick, widespread crust formed in mid February now sits 50-90 cm deep. Near Mt Cain, the crust is glassy with faceted crystals sitting on top of it, which makes for a poor bond to the overlying slab of snow. For more details, check out this reel from our field team! Elsewhere the crust seems to be bonding well. You can check the bond in your local area by performing a simple hand shear test on an isolated block.

The mid and lower snowpack is well consolidated, containing a series of well-bonded crusts.

Weather Summary

Monday night

Cloudy and stormy. Up to 15 cm of new snow. Wind from the east and southeast at 30 km/h. Temperature -4˚C at treeline elevations.

Tuesday

Cloudy with sunny breaks. Snow ending in the morning. Wind from the southeast at 30 km/h. Temperature -6˚C in the morning rising to -2˚C in the afternoon.

Wednesday

Broken skies in the morning with clouds moving in by the afternoon. Snow beginning in the early afternoon with up to 10 cm by the end of the day. Wind from the southeast at 15 km/h. Temperature -3˚C.

Thursday

Cloudy with flurries bringing 5-10 cm of new snow. Wind from the southeast at 20 km/h. Temperature -3˚C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
  • Start on smaller terrain features and gather information before committing to bigger terrain.
  • Be carefull around freshly wind loaded features.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Recent storm slabs are now 30-60cm deep with more snow in the forecast. Some of these slabs sit on top of a crust. Assess the bond between storm snow and underlying crusts closely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 7th, 2023 4:00PM