East Slopes South

Although the danger is low, small avalanches remain possible to trigger in isolated areas. Increasing winds may drift dry snow on shaded aspects into the lee of ridgelines where you can trigger a shallow slab.  Firm or breakable crusts make for challenging travel at lower elevations and on sun-exposed slopes.

The East South zone has experienced mostly cloudy skies with calm or light winds in the last 24 hours, allowing older wind slabs additional time to settle and improve their bond to the underlying crust. A few snow showers may have made it over to the east slopes in the southern part of the zone, where Signal Peak reported 0.15" of snow water equivalent (perhaps 1.5" of snowfall) in the afternoon. Most areas have up to 6" or so of snow above the Early February Crust. Down-sloping winds warmed temperatures at lower elevations while enough sun energy made it through to moisten snow surfaces on SW-S-SE aspects. In these areas, you can expect surface crusts on Thursday. In some wind-exposed areas and at lower elevations, the Early February Crust may be at the surface. It could be slick and difficult to arrest a fall on a steep slope.

We're not expecting much in the way of snow accumulation through Thursday, but increased light to moderate W and WNW winds on Thursday may start moving dry snow near ridgelines. The winds could build fresh, shallow slabs that you can trigger. Most of these will be little more than a nuisance. Winds could drift snow onto weakening snow surfaces, creating the potential for wider propagation than you expect. You can also trigger an older slab above the Early February Crust. Last Friday, in nearby East Central, Katie Warren found widespread surface hoar and an inch of weak, faceted snow above 5700ft on the Early February Crust. Slabs sitting on such a crust-facet interface would have extended reactivity. It's a good idea to keep tabs on the thickness of these potential layers of snow deposition and monitor their interfaces. You can trigger a slab large enough to take you for a ride on steep slopes where either of these layers is thicker than 6".  You're most likely to trigger a wind drift on the N or E sides of ridgelines. Visual clues such as textured surfaces, corniced ridges, and drift formations around rocks or trees can all point you to wind-loaded terrain. Slopes below corniced ridges and confined alpine features like steep couloirs and sharp ridgelines are likely spots for wind slabs. Consider the consequences of even a small avalanche in very steep rocky terrain. 

Crusts may or may not soften on Thursday. If the sun comes out, it will have to break down surface crusts and overcome the cooling associated with increasing winds.  If you encounter moist, sticky snow or rollerball activity, consider moving to shady slopes or lower-angle terrain. An avalanche may become large enough to bury you in a terrain trap such as a creek or gully.

The snowpack endured a beating last week with several inches of rain and warm temperatures. You'll see evidence of very large avalanches that released in the January 21st through February 1st time frame. Fortunately, since February 1st, middle and upper elevations have stayed below freezing, creating a new ground for potential avalanche activity (the early February Crust). If you head out, please help us improve your forecast by submitting a public observation!