Friday April 2, 2021
Cornice Fall, Loose Wet, Wind Slab
Travel & Terrain Advice
Caution when transitioning into freshly wind loaded slopes.
Avoid travelling both above and below cornices.
As you descend in elevation , the loose wet avalanche problem is likely to present.
During a flight check of the island alpine southern zone a widespread natural loose wet cycle in the Alpine and tree line on steep solar features up to size 2.5 was observed. Loose and wet snow in steep terrain was observed gaining mass in gulley features and running to mid and lower paths.
Cornices are widespread and large. Previous warming and cooling may have added some temporary strength, This problem will persist through the remainder of the season and can be both a trigger for slopes below as well are large enough to create an avalanche hazard alone.
Location: Predominantly north aspects at ridge top in the Alpine and Tree line.
Possibility: Triggering of this avalanche problem is unlikely to possible from light loads such as skiers/snowmobilers. Natural avalanches are unlikely to possible.
Size: If triggered expect these avalanches to be large size 2, on isolated terrain features very large, size 3
Precipitation and above zero temps below 800 meters are possible during this forecast period. Loose wet is likely to continue to persist at the lower elevations.
Location: Below 800 meters on all aspects.
Possibility: Triggering of this avalanche problem is possible from light loads such as skiers. Natural avalanches are unlikely.
Size: If triggered expect these avalanches to be small size 1, and on isolated terrain features they may be able to gain mass and could be large, up to size 2 .
This new avalanche problem is likely to form during periods of snow fall and moderate to strong south west winds.
Location: North East thru to North West aspects and found in both the Alpine and Tree line.
Possibility: Triggering of this avalanche problem is unlikely to possible from light loads such as skiers. Natural avalanches are very unlikely.
Size: If triggered expect these avalanches to be large size 2.
Past warm and sunny conditions followed with periods of overnight cooling have continued to slowly settle and strengthen the entire snowpack. All snow surfaces including north aspects became moist, with solar aspects becoming unconsolidated down 10-15cm. A cooling trend is expected to refreeze the upper snowpack and proved a new surface for incoming precipitation to slide on.
|Surface||Moist, expected to refreeze into a meltfreeze crust|
|Upper||Well settled with a number of unreactive laminated crusts|
|Mid||Well settled and dense.|
|Lower||Well settled and dense.|
A series of cool nights and warm and sunny days with no precipitation.
A south west flow will deliver this forecast period overcast sky and periods of flurries for most days, Forecast models indicate that increased precipitation amounts are likely in the northern half of the forecast area.
Friday: Trace amounts of snow. Winds Light to Moderate from the Southwest, Freezing levels 200 meters rising to 800 meters. Temps at 1500 meters -6
Saturday: 5 to 15 cm of snow, Winds Moderate to Strong from the South West , Freezing level 700 meters rising to 1000 meters. Temps at 1500 meters -4
Sunday: Trace amounts of snow. Winds Moderate to Strong from the North West, Freezing levels 400 to 1000 meters. Temps at 1500 meters -4
Posted on Friday April 2, 2021 by Jesse Percival