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Avalanche Forecast

Feb 23rd, 2025–Feb 24th, 2025
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

The hits keep coming! It's another day to investigate new snow amounts and reactivity before committing to avalanche terrain. Expect the greatest hazard on lee slopes at high elevations.

Confidence

Moderate

Avalanche Summary

Heavy rain Saturday night likely produced a natural wet avalanche cycle. Before the rain took over, ski cutting in the Mt Washington area was yielding wind slab releases up to 20 cm deep in immediate lees on north and east aspects, as well as small dry loose avalanches. Similar conditions can be expected for Monday, minus the high elevation rain.

Snowpack Summary

15 - 30 cm of heavy new snow should accumulate by Monday morning, burying a rain-saturated surface in most areas or 5 - 10 cm of similarly wet snow in the alpine and upper treeline. The new snow should produce short-lived surface instabilities.

A sandwich of surface hoar and faceted snow overlying the late January crust 40 cm deep produced concerning snowpack test results thoughout last week. Crust formation on Sunday should cap this problem almost everywhere, although its status in the alpine is uncertain.

The lower snowpack is well settled.

Weather Summary

Sunday Night

Cloudy with wet snow showers bringing 15 - 30 cm of new snow, increasing with elevation, rain below 1000 m. 60 to 80 km/h southwest ridgetop wind. Freezing level 1300 m.

Monday

Partly cloudy with scattered wet flurries in the afternoon, minimal accumulation. 30 to 70 km/h southwest ridgetop wind shifting southeast. Freezing level reaching 1400 m.

Tuesday

A mix of sun and cloud with 5 - 25 cm of heavy new snow from overnight, increasing with elevation and proximity to the west coast. 20 - 30 km/h variable ridgetop wind. Freezing level reaching 1500 m.

Wednesday

Mainly sunny. 50 - 70 km/h southeast ridgetop wind. Freezing level shooting to 2500+ m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Make observations and continually assess conditions as you travel.
  • Investigate the bond of the recent snow before committing to your line.
  • Be alert to conditions that change with elevation, aspect, and exposure to wind.
  • Avalanche activity is unlikely when a thick melt-freeze crust is present on the snow surface.

Avalanche Problems

Storm Slabs

15 - 30 cm of overnight snow should produce a reactive storm slab problem still needing to be managed on Monday. Expect the greatest hazard at higher elevations toward the west Island and where wind has formed deeper accumulations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2

Persistent Slabs

A 40 cm-deep combo of surface hoar, facets, and crust saw a big test with Saturday's storm. Until we know it's either been cleaned out or capped by crust, be wary of larger triggers like falling cornices or machines in north-facing alpine.

Aspects: North, North East, East, West, North West.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1.5 - 2.5