Avalanche Advisory for Friday, December 28, 2007 at 6:45 am By Eric White & Nick Meyers The Details: This Season: We had a few early season hints of snow in October, then a dry spell with December starting to show signs of winter. Our precipitation is around 88% of normal. We currently have around 3 feet of recent snow on a thin old snow surface. We are in a "La Nina" climate condition which often means wetter than normal winters in our area and expectations are above normal precipitation into the spring of 2008. Weather Observations: We have thin overcast skies and cool temperatures this morning. Mt. Shasta - We have 34 inches of snow on the ground near tree line with 2 inches of new snow over the last 24 hours. The snow settled 1 inch in the last 24 hours and temperatures have ranged between 11F and 20F at 7000 ft. and it is currently 15F. Winds this morning at tree line were estimated at around 30 mph from the W, and 15-20 mph from the W below tree line. On the upper mountain winds are estimated this morning at 70 mph from the NW. The jet stream is overhead this morning with 130 knot winds from the NNW. Castle/Mt. Eddy - Mt. Eddy received 1 to 2 inches of new snow in the last 24 hours with 1 inches of settlement. Temperatures stayed cool between 13F to 19F over the last 24 hours. We estimate around 2 ft. of snow on the ground with brush showing. Castle Lake is around 19F this morning. Weather Forecast: We are in between storms right now with a warm front and big moisture plume out in the Pacific. We will have light snow showers this morning and increasing snow fall this evening into tomorrow morning as the next front moves in. Although this storm looks good, it will travel in a similar direction as yesterday's storm, from the northwest, which isn't favorable for precipitation on the south side of Mt. Shasta. Areas in the Klamath Mountains and Medicine Lake highlands may see more precipitation, but in our area, accumulations of 2-4 inches is more likely by tomorrow morning. Snow levels will remain low this morning (1500 ft.) and rise slowly today and tonight to around 4500 ft. We will have a break Sunday into the New Year with wet weather in the first week of January. For today we will have cloudy skies with increasing snow fall this evening and temperatures at mid elevations in the upper teens to low 20's. Winds below tree line will be from the W at 10-20 mph, with winds at and above tree line at 30 mph from the NW, increasing tonight to 50-60 mph from the WNW. On the upper mountain today winds will continue at 60+ mph from the NW with a wind chill temperature of -26F. Snow Pack: We have "dust on crust" again today. Concerns for small wind slabs continue on S and E aspects. The crust underneath our recent dusting of snow is poorly bonded to the snow beneath it, with many facets (weak layer) present. The small wind slabs could take you for a ride on the firm snow above tree line. The best conditions will be below tree line, but areas of breakable crust will challenge skiers. Forest Service Ranger examing the snow 12/26/07. Nick examines the crust 12/26/07 after easy failures. Some important thoughts: This advisory does not apply to Ski Areas or Highways and is for the Mt. Shasta, Castle Lake and Mt. Eddy back country. Use this information for guidance only. You may find different conditions in the backcountry and should travel accordingly. This advisory expires at midnight tonight. As always, use safe travel practices: travel with a partner, travel one at a time in suspect areas, go from one island of safety to another, choose safe routes, wear a transceiver, carry a shovel and probe, and know how to use your gear!