Backcountry Avalanche Forecast for Front Range Issued 01/11/2010 6:52 AM by Spencer Logan Highlights An ugly snowpack is producing some large avalanches. The weak snow at the base continues to plauge us, and you should be suspicious of all steep slopes. Avalanche Danger The avalanche danger in the Front Range zone is CONSIDERABLE on all slopes above treeline and on N-E-S facing slopes near and below treeline. Human triggered avalanches are probable. On other aspects the danger is MODERATE. Human triggered avalanches are possible. Snow & Avalanche Discussion Recent avalanche and instability highlights: Sunday: Two large avalanches on the Second Creek Headwall north of Berthoud Pass. Easterly aspects above treeline, and combined the crowns stretched over 1000 feet. Two small human triggered avalanches in the Berthoud area, below treeline on east and northwest aspects. Whumpf "so loud I thought Winter Park was using explosives" and about 600 square feet of the slope cracked. See the Vail Summit forecast for some more large, human triggered activity. Saturday: Large, remotely triggered avalanche on south Diamond Peak above Cameron Pass. It was on a northeast aspect above treeline, several feet deep, 600 to 800 feet wide, and ran about 600 vertical feet. It covered tracks on the lower-angled bench at treeline. Friday: A snowmobiler near Jones Pass triggered a hard slab on a north aspect above treeline slope that was 6 to 8 feet deep and over 300 feet wide. Explosive triggered avalanche in the Stanley path above US40 on Berthoud Pass. The slide was on southeast aspect above treeline, 2 to 5 feet deep and 900 feet wide. So, what does that activity add up to? A pretty ugly picture. There is a persistent, widespread weak layer of sugary facets and depth hoar at the base of the snowpack. It is a problem that just won't go away. In mid-December the signs of instability were widespread. They are not as common now, but are big when you find them. Some steep slopes are being ridden without consequence, and large avalanches are being triggered on others. Remotely triggered avalanches make the picture even uglier. The snowpack is highly variable, and figuring out if you are poking onto a touchy or stubborn slope is not easy. You will need to evaluate each steep slope seperately. Whumpfs and cracks are clear indicators that you have a weak layer and slab that can avalanche. If you don't feel comfortable evaluating each snow slope, stick to low-angle terrain. Make sure everyone in your group is carrying avalanche rescue equipment and knows how to use it. One-at-a-time on steep slopes, and move well out of the way at the bottom. These travel practices can minimize the consequences if you do trigger an avalanche. Weather Discussion There is a high pressure ridge overhead today. It will keep the weather boring--mild, sunny, light winds. Today will be a few degrees warmer than yesterday, and a few degrees warmer than it will be Tuesday. The light winds will do a full 360 over the next 24 to 36 hours. Organized southwest flow will establish itself Tuesday evening as the ridge shifts east and opens the way for Wednesday's storm. The storm will hit the west coast strongly Monday night. Models have been consistent with the storm developing a closed low over the Great Basin which tracks sharply south. That track does not set us up for much snowfall, and what we get will fall Wednesday night into Thursday.