Avalanche Advisory for Wednesday, January 2, 2008 at 6:30 am By Eric White Special Note: The Avalanche Danger is expected to increase with strong winds and heavy snow fall from Thursday, January 3 through Sunday, January 6. The Details: This Season: We had an early thin snow pack with December bringing near normal precipitation and 3.5 feet of snow along with strong winds above tree line. Our precipitation is around 82% of normal since September 1. We currently have around 2-3 feet of snow below tree line and from 0-6 feet of snow above tree line. We are in a "La Nina" climate condition which often means wetter than normal winters in our area and expectations are for above normal precipitation into the spring of 2008. Weather Observations: We have a thin layer of high clouds overhead this morning with a temperature in town of 34F. Mt. Shasta - We have 33 inches of snow on the ground near tree line with no new snow over the last 72 hours. The snow settled 1 inch in the last 24 hours and temperatures have ranged between 30F and a toasty 43F at 7000 ft. and it is currently 33F. Winds this morning at tree line were estimated at around 45 mph from the SW, and 15 mph from the S below tree line. On the upper mountain winds are estimated this morning at 70 mph from the SW. Castle/Mt. Eddy - Mt. Eddy received no new snow in the last 72 hours with 1 inch of settlement over the last 24 hours. Temperatures were between 34F to 45F over the last 24 hours. We estimate around 2 ft. of snow on the ground with brush showing. Castle Lake is around 26F this morning. Weather Forecast: A low pressure trough from the Gulf of Alaska is poised off our coast today and will bring us our first large winter storm of the season from Thursday through Saturday. Strong winds and heavy snow fall are expected, especially on Friday. Although we will get from 2.5 to 5 feet of snow from this series, the central Sierra looks like it may poised to receive that much or more! Snow levels during this storm will fluctuate around town to 4500 ft. and drop down to 1000 ft. on Saturday after the bulk of the precipitation has fallen. For today we can expect partly cloudy skies with temperatures between 28-40F at mid elevations. Winds below tree line will continue from the S to SE at 15-20mph with winds above tree line at 45-50 mph from the SW. On the upper mountain, winds will be 50-70 mph from the SW. Snow Pack: Variable conditions will be found today with breakable crust in open sunny areas below tree line, stashes of powder on northerly aspects and firm, wind scoured snow and rocks above tree line. Areas of wind slabs still exist, mostly above tree line on S and E aspects and will be a little more sensitive during the warmest parts of the day. This will create pockets of Moderate avalanche danger above tree line and mostly Low avalanche danger elsewhere. Of note for the upcoming dump of snow are potential weak layers on the snow surface. We have surface hoar in many open locations below tree line which are not in direct sunlight. We also received a layer of graupel in our last snowfall. Even without these, the forecast intensity of snow fall and heavy wind loading in the upcoming storm series will create instability and safe route finding and caution will be needed. Remember, the access roads to Castle Lake and Bunny Flat may be closed and remain unplowed for a few days during large winter storms. 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!