The avalanche danger remains MODERATE today with several potential problems.
As the day heats up, so will the likelihood for wet avalanches, especially human triggered. This includes loose wet or even wet slab avalanches. Best practice is to stay off of steep slopes that are unsupportable, especially if they are wet and sloppy.
Poor snowpack structure exists with consolidated slabs resting on buried persistent weak layers of loose, sugary, faceted snow on many aspects. The most dangerous areas are on slopes near and above treeline that face NW-N-SE where wind drifted snow has created slabs 1'-3' deep on top of these buried weak layers. These avalanches are becoming harder to trigger but once released, they will be large and destructive. Likely trigger points include shallower areas along slope margins, around sparse trees or rock outcroppings, or on repeat running slide paths.
The pit profile below illustrates the existing poor structure on a NW facing slope near treeline. The farther a layer moves to the left, the stronger or harder it is. We are looking for strong layers over weak layers. Note the strong layer over the weak layer of sugary, faceted snow at about 53 cms.
Strong southerly winds have created fresh deposits of wind drifted snow upper elevations. Look for fresh drifts on the leeward sides of ridge crests and terrain features like sub-ridges and gully walls. On steep, northerly aspects, wind drifted snow has added additional stress to buried persistent weak layers so it isn't merely a question of identifying and testing for wind slab instability. The bottom line is that steep, wind loaded, northerly-facing terrain is where you are most likely to trigger a deep and dangerous avalanche.
The Geyser Pass Roadis down to the dirt on the lower third. The upper third is a sloppy slurry of mud and melted snow.
The Lower Utah Nordic Alliance (LUNA) groomed and set classic track into Gold Basin on Thursday. Traffic over the weekend has roughed up the surface.
24 Hour Snow T" 72 Hour Snow T" Base Depth in Gold Basin 46" Wind S 20-25 G40 Temp 35F
It's going to be a different kind of spring day today as "an aggressive little wave" (NWS quote) moves quickly through bringing clouds, flurries, and yes, wind! Overnight temps remained quite warm and we did not see a refreeze below 10,000'. Temps around 11,000' dipped into the 20's. Southerly winds cranked all night and will continue to do so today. Clouds should clear out later in the day and high temps will again rise into the mid 40's. Tuesday will me mostly sunny, warm, and breezy. A much anticipated cut-off low will begin moving inland and across the Great Basin on Wednesday. We'll see mostly cloudy skies followed by hopefully, some snow on Thursday.
Wind, temperature, humidity on Pre Laurel Peak (11,700')
Snotel site near Geyser Pass Trailhead (9600')
Storm totals at the Gold Basin study plot (10,000')
Snowpack Discussion
In my travels yesterday I found everything from settled "recrystallized powder" on sheltered northerly aspects; to sun and wind crusts; to downright sloppy conditions. Natural signs of wet instability over the past few days have been surprisingly lacking though I did find a few loose snow sluffs on steep, SW facing slopes near and just below treeline. Today will be tricky without a solid refreeze overnight, but with clouds and wind keeping things somewhat cooler for awhile. Best rule today will be to stay off slopes that don't have a supportable crust or that become wet and sloppy when the day heats up.
On the cold snow front, weak, faceted snow can still be found on most aspects and stiff, hard slabs 1'-3' thick exist over this weak layer on slopes facing primarily NW-N-E-SE. These are becoming harder to trigger but shallow areas, along slope margins and near rock outcroppings or sparse trees remain likely trigger points. Also, be wary of steep convexities and blind break overs, and be advised that slopes steeper than 35 degrees are still a gamble.
This forecast is from the U.S. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.
