Quick report
- Red Flags
- Poor Snowpack Structure
- Red Flags Comment
- <p>Snowfall from Friday 1/5 preserved the weak snow that was widespread on most snow surfaces at all elevations.</p>
Today's goal was to see how well preserved the old snow surface was underneath the small amounts of new snow from Friday, Jan 5. On Thursday, Jan 4, I was on Rodeo Ridge and was finding weak snow on all snow surfaces facing west, north, and east, from valley bottoms to 8,600' at the top of the Ogden Skyline ridgeline. With light winds, the 5-10 cms of snow from 1/5 preserved the weak snow underneath and it was easy to get sluffing in the new snow on steeper aspects. Additionally, we were finding pockets of wind-drifted snow above 7,000' from the moderate to strong southwest winds. These drifts were shallow - 5-15 cms thick - but very reactive as they formed on top of weak, faceted snow underneath.
Bill Brandt was also on Cutler Ridge today (1/6) and found the same conditions.
With more snow and wind beginning Saturday night and lasting through much of this coming week, the avalanche danger will rise and remain elevated for quite some time.
Photos of wind effects and cracking in fresh wind drifts.
With a rising avalanche danger and a persistent weak layer (PWL) problem, we have to find the slopes that currently do not have a PWL. Most slopes facing south and southeast are essentially bare (I do not have enough data for southwest aspects) and these slopes will be the first to stabilize.
Snowpack
- Instability Comment
- <p>Southwest winds created pockets of wind-drifted snow down to 7,000'.</p> <p>The photo below shows the typical snowpack structure with faceted snow underneath the 1/5 storm snow with facet/crust combinations below that. We currently don't have enough of a load for widespread avalanching, but the snowpack structure is so weak that it won't take much more storm snow or wind-drifting for these layers to become reactive. </p> <p> </p>
5-10 cms storm snow above 6,500'