Avalanche Forecast

Over the past week the snowpack at Hurricane Ridge has consolidated 18 inches as a result of both rain last weekend and mild temperatures much of this past week. A clear and cold night Thursday allowed for a very strong surface crust to form by early Friday. The strong crust to all elevation bands is limiting the potential for avalanches in this zone.The mid and lower snowpack in this area is a few months ahead of schedule and already resembles mid-spring snow conditions as a result of extended warm temperatures or rain to high elevations. Melt water has now drained through uniformed snowpack that ranges fairly dramatically from about 3-4 ft on solar aspects to 7-10 ft in the deepest shaded slopes.The recent warm and wet weather has also allowed glide cracks to open on several slopes with smooth ground surfaces. Some of these glide cracks produced large Glide Avalanches over the past week in common locations such as Steeple, and the Steep-and-Icy avalanche paths.Cornices have reduced in size significantly over the past week of mild and periodically wet weather. 

NWAC pro-observer Matt Schonwald and NPS Rangers traveled in the Mt Angeles areas Thursday, 2/8. The snowpack was described as a fairly uniform, well drained late spring snowpack, lacking any distinctive layering. The recent warm weather, rain and winds have melted or stripped significant snow from the southerly facing terrain and even shaded terrain near large rocky features. There were a few glide avalanches observed, likely releasing last Saturday during a rain event. Cornices had been trimmed greatly over the past weeks mild and wet weather.

Avalanches are unlikely today. No significant avalanche problems exist in this region as a result of a very strong surface crust and uniform well consolidated snowpack.  Continue to use normal caution. Always carry a beacon, shovel, and probe and use travel practices that minimize your exposure to avalanche terrain.There are however other travel hazards outside of avalanches to be considered to stay safe in the mountains under the current conditions.A hard smooth surface crust has formed as of Friday and should persist Saturday following a clear cold night. A slip and fall in steep terrain above rocks or cliffs could be today’s biggest hazard in the mountains.Several glide cracks have been reported so watch for these potential travel hazards. With the cool expected weather, these cracks are more of a danger if you fall in them than an avalanche problem.

A strong upper ridge of high pressure remains will remain far enough offshore that the Pacific Northwest will experience low freezing/snow levels through the weekend. Although temperatures at most NWAC stations were in the 10's and 20's, the influence of the offshore high pressure ridge has enabled temperatures to warm up substantially, particularly west of the Cascade Crest. Hurricane Ridge saw temperatures rise 20F over the course of 5 hours on Saturday morning. The flow in most locations has shifted  to westerly as a moisture-starved upper-level and surface closed low will approach from the northwest. The approaching low will bring a another shot of cooler air into the Pacific Northwest, but without a significant frontal feature. Westerly winds will increase into the moderate range at crest level over the north and central Cascades as the low approaches.This fast-moving low will approach the near-shore waters late Saturday night and by Sunday morning it will make landfall on the central Oregon coast.The compact low will bring a chance of some very light snow showers to the Olympics, central and south Cascades, and Mt. Hood, but it doesn't look like much moisture will make it onshore, so mostly expect clouds and cooling from this system.Sunday night, expect clearing skies and with colder temperatures due to radiational cooling along with colder air moving in from the interior on weak NE flow as a high pressure builds offshore once again. Snow levels will fall to very close to sea level.

A northeasterly flow will keep cool air in place on Monday as fair weather prevails. Monday night the flow aloft  will switch to northerly as an E-W oriented high pressure bulges into the Pacific Northwest with a deeper trough to the north and the departed closed low to the south over California. Light to moderate easterly flow can be expected at the passes Monday and Monday night. Tuesday will feature high pressure with light winds and warming for many locations as an approaching system from the N-NW shifts the flow to allow warmer air from the Pacific high to come onshore. Expect more spring-like conditions on Tuesday.Tuesday night will see the onset of a broad trough and a weakening storm system on N-NW flow. Temperatures will cool significantly as the storm approaches and arrives with low snow levels on Wednesday. Snow showers can be expected in the mountains Tuesday night and Wednesday on a cool N-NW flow.