Loose Wet
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 1
Clear skies last night and overnight air temperatures in the low to mid 30s are expected to have allowed for a decent to very good snow surface refreeze to have occurred again last night. As is often the case in this area, radiational cooling is the major driving factor in creating snow surface refreeze in locations where overnight air temperatures were above freezing. With yesterdays surface melt not thawing all the way through the surface melt-freeze crust, a thick surface melt-freeze layer is expected this morning.
Supportable conditions are expected through the morning hours today. Snow surface melt will occur more rapidly today than yesterday, but ongoing light to moderate speed E to NE winds will aid in slowing the rate of snow surface melt. Sometime during the mid day to afternoon hours conditions will eventually become less supportable and loose wet snowpack instability will increase. Human triggered loose wet avalanche activity could occur this afternoon in isolated areas on E-SE-S-SW aspects.
Once several inches of wet snow form on the snow surface and body weight boot penetration approaches 1 foot deep or more into surface wet snow, it is time to take active measures to avoid avalanches. Change to a more northerly or westerly aspect and/or move to slopes less than 35 degrees in slope angle without steeper terrain above. Planned timing of travel in avalanche terrain is critical for the preferred mix of frozen to melting, but still supportable snow surface conditions.