High pressure continues to deflect any storms heading for the California coast. Temperatures have been near 20 degrees above normal for this time of year on occasion. It feels like April and if you time your day right you can ski spring snow on southeasterly slopes. But it isn’t April, it’s February and while the air temperature is mild, the sun is still too low in the sky to create good corn skiing on northerly aspects. The picture in the mountains is one of two snowpacks coexisting just a ridgeline apart. Cold winter snow ranging from surface facets to wind blown has been found on cooler northerly slopes while the melt-freeze process has been transforming and thawing solar aspects. It’s a complicated situation.
Test results targeting persistent weak layers of sugary facet snow on northern slopes still show some potential for failure. We haven’t seen any avalanches on these layers this season, primarily due to the lack of snow. Slope-wide failure would most likely require a heavy slab on top that exceeds the strength of the underlying snowpack. We have been monitoring these layers all season and their strength has waxed and waned. They will continue to be of interest if you want to play on north-facing wintry snow because while triggering these layers is very unlikely the resulting avalanche could be large. We will have to wait and see if we ever get a big enough dump to overpower these persistent weaknesses.
Meanwhile, solar radiation will continue to thaw southerly slopes as the sun climbs from E to S to W throughout the day. Clear skies and below freezing temperatures overnight have allowed the snowpack to get a good re-freeze in most areas. Clear skies and calm winds will allow the snowpack to heat up quickly and the thawing process will begin all over again. No new wet instabilities have been reported in the forecast area, but that does not mean that getting caught in the wrong place at the wrong time is impossible. If you find yourself on steep solar slopes, especially near rock outcrops by midday you may find loose wet avalanche activity. Avoiding slopes that are warm enough for large rollerballs or to sink in past your boot tops is the best way to keep yourself out of trouble.
Coverage remains thin and obstacles abound. Be wary of rocks and logs just below the snow surface.
Early in the day, and as slopes re-freeze in the afternoon, hard and fast conditions could turn a simple fall into a dangerous slide.
