The dry weather continues. There is not enough snow to warrant avalanche danger ratings. Once snow comes, advisories will resume. For updated snowpack conditions, see the text discussion.
With sparse snow cover, there is a high level of variability in snow depths but not in the snow structure. Over the past week, snow depths range from bare to 4” to 24” depending on aspect, elevation, slope configuration and whether slopes are shaded or non-shaded. On Tuesday, we visited some north facing mid elevation terrain in the Minaret Summit area. The snow structure is similar to the snow in Rock Creek and in the Mammoth Basin. The sun crusts at the snow surface and within the “snowpack” assist the faceting process.
It appears that the depth hoar is becoming larger, better developed and increasing in density. Some of the increase in density comes from gravity – the individual grains slip and rotate with their neighboring grains. Snow becomes stronger more by the sintering process. With a temperature gradient of 1.8C from the ground to the snow surface in 34 cm of snow, the faceting process will continue until more snow falls, air temperatures increase or spring comes.
|0600 temperature:||20 deg. F.|
|Max. temperature in the last 24 hours:||47 deg. F.|
|Average wind direction during the last 24 hours:||NE|
|Average wind speed during the last 24 hours:||10-20 mph|
|Maximum wind gust in the last 24 hours:||20 mph|
|New snowfall in the last 24 hours:||0 inches|
|Total snow depth:||15-20 inches|
As we all probably know, the National Weather Service forecast calls for mostly sunny skies for the week. Highs will reach the mid 40’s today at the 8,000 to 10,000 ft elevations, then warm a few degrees to around 50 F on Thursday and Friday. Nights will be cool with lows in the low to mid 20’s.
The latest long range diagnostics continue to point toward high confidence in a blocking ridge of high pressure over California and Nevada through at least mid to late next week. This will shift the storm track well north of the area. This ridge is unusually strong and persistent.
There is a small chance of a weak low pressure storm squeaking in under the ridge and producing some light precipitation in the Sierra and slightly increased winds next week but confidence is low. In general light winds and weak-moderate valley inversions will be the rule.