Avalanche Forecast

A low pressure system is expected to move across the Washington Oregon border area on Tuesday. This is expected to cause the strongest winds, the most snow and possibly the most fluctuation in temperatures in the south Cascades.

With this next unusual and hard to predict incoming storm, so much recent snow, lack of knowledge of stabilizing of recent snow, and lack of knowledge of bonds to the Valentines Day crust, there is GREAT UNCERTAINTY in the avalanche forecasts at this time. This is a time to plan travel on lower angled terrain well away from avalanche paths or run out zones. Avoid large steep open slopes or terrain of consequence. Change your plans if weather and snow conditions are different than expected.

More than the usual zones are in this forecast due to the expected differences from south to north on Tuesday.

Alpine winds have recently been SW to W, with further mostly SW to W winds expected on Tuesday. Hence wind slab should be most likely on northwest to southeast aspects. But watch for firmer wind transported snow on other aspects especially in areas of complex terrain.

Most areas have experienced rapidly accumulating snowfall and temperature fluctuation the past couple days. Storm slab from this weather may not have stabilized. More areas of rapidly accumulating snowfall with fluctuating temperatures are expected on Tuesday.

Cornices won't be listed as an avalanche problem but avoid travel on ridges near where cornices may have formed and avoid steep slopes below cornices that may fail at any time.

Weather and Snowpack

The most recent warm, wet storm arrived on Valentines Day 2/14 forming a strong rain crust, now buried 2-3 feet or more in the Hurricane Ridge area.

Strong southwest flow carried a strong front across the Northwest on Friday evening. This caused strong southwest alpine winds and heavy, moist, dense new snow above about 3-4000 feet.

Between the NWAC station at Hurricane and the ranger reports it looks like there has been about 2-3 feet of snow the past 3 days at Hurricane.

A region wide avalanche cycle was seen late Friday and Saturday, with some more avalanches on Sunday.

Recent Observations

NWAC observer, Matt Schonwald was at Hurricane on Friday and found that ski tests were showing rapidly increasing propagation and increasing sensitivity of the deepening storm slab. Previous winds had loaded various slope aspects while south winds on Friday were loading N aspects.

Reports by NPS rangers early Sunday and a report listed on the NWAC Observations page indicate there were at least three and possibly four separate triggered avalanches in the Hurricane Ridge area Saturday 3/4, including the areas known as Maggies, Hurricane Hill and Sunrise Face.