Aspen ===== Current Keywords: LOW, MODERATE, avalanche danger, entrained, explosive, faceted, high pressure, lee , paths, slab, slabs, sluff, sluffs, trough, weak layer, wind transported, windloaded, Mountain Weather and Avalanche Forecast for the Aspen Zone Forecast Issued on 12/19/2007 3:13:32 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 9-14 21-26 5-10 Wind Speed(mph) 10-20 15-25 G 30s 10-20 Wind Direction W W WSW Sky Cover Mostly Cloudy Mostly Cloudy Overcast Snow(in) 0-2 1-3 2-4 Snowpack Discussion Observers in the Ashcroft area over the weekend and Monday found some cracking but the slab would not move . This cracking was found on a steep ENE chute at about 11,600 feet on a sub peak of Green Mountain. A few sluffs of near surface faceted snow were noted on some short steep paths near the Markly Hut. It only entrained the top 3-4 inches of snow, but built up to about 3 feet deep at the bottom of the slope. The higher elevations continue to see some wind transported snow onto lee aspects, but there is not a whole lot left to move from the westerly aspects anymore. The last avalanches reported from the Aspen zone were on the 17th and were explosive triggered slabs. I do not have details, but I would suspect they were on lee aspects to the westerly winds we've had recently. One wet slab was triggered from a sluff off a cliff band near Montezuma Basin above Ashcroft on the 16th, Sunday. This was also a a small slide on a southerly aspect below treeline. Avalanche Danger Above treeline the avalanche danger is MODERATE on all aspects. Near and below treeline, danger is MODERATE on slopes facing west, northwest, north, northeast, and east. The danger is LOW on other aspects. Unstable windloaded slabs are possible eon most steep slopes. High elevation, shady slopes may have a weak layer at the bottom of the snowpack at a perfect depth for human-triggering. Your backcountry observations are very helpful to our forecasts. If you are traveling around Aspen Zone, we would love to know what you're seeing. Drop us a quick [57]e-mail with your observations from this area or any other. Front Range =========== Current Keywords: CONSIDERABLE, MODERATE, avalanche danger, cross loaded, denser, drifted, drifts, high pressure, human triggered, human triggered avalanches, lee , natural, natural avalanches, path, powder. , slab, slabs, trough, weak layers, wind loaded, wind slabs, Mountain Weather and Avalanche Forecast for the Front Range Zone Forecast Issued on 12/19/2007 2:53:22 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 9-14 17-22 8-13 Wind Speed(mph) 22-32 G 50 22-32 G 50 13-23 G 30 Wind Direction W W W Sky Cover Mostly Cloudy Increasing Mostly Cloudy Snow(in) 0-2 Tr-3 1-3 Snowpack Discussion Next door in the Vail/Summit County zone a skier triggered a slide on the Little Professor slide path off Loveland Pass Monday. The slide initiated on a wind loaded south aspect just below the ridge, cracking 1 to 2 feet deep. Several more triggered and natural slides occurred near Loveland Pass over the weekend as well. They primarily slid on heavily wind loaded north and easterly aspects above treeline. Backcountry travelers also noted both human triggered and natural avalanches in the Cameron Pass area over the weekend. Two separate parties remotely triggered slides on northerly aspects near and below treeline, one on Seven Utes Mountain, the other off Clark Peak. Observers noted natural avalanches above treeline on the NE aspects of the Diamond Peaks and the W aspect of Clark Peak as well. On the lower angle terrain below treeline people in general enjoyed a non-reactive snowpack Strong and steady winds have drifted and transported snow onto a variety of aspects above treeline. Expect to find fresh wind slabs, sensitive drifts, and cross loaded terrain features on higher elevation slopes as well as on exposed areas below treeline. Many of the new slabs formed on top of the older powder. This strong over weak configuration can be triggered with the additional weight of a backcountry traveler in the wrong spot. Some recent reports from around the state hint that these wrong spots might be further down slope where the denser hard slab softens up. They wrong spot might also be in a thinner area of snow cover, like rock outcrops, or shallow covered cliff bands. The last rreported slide in the Front Range zone was on the 16th, Sunday. We have seen little new snow now since Sunday. Winds however continue to deposit snow snow onto lee aspect terrain. Generally it would be easy for me to lower the danger after a long spell of no activity. With the hard slab overlying weak layers, I would have trouble center punching wind loaded bowls and gullies. It's easy to get lured out into these areas if we are not seeing avalanche activity. Hard slabs are an insidious beast. They love to lure us further onto avalanche slopes and just when we think we have dodged the monster, boom, we are off on Mr Toads wild ride. I will leave the danger as is and re-evaluate Thursday. Avalanche Danger The avalanche danger for the Front Range zone is CONSIDERABLE on northwest, north, northeast, east, and southeast aspects near and above treeline. Human triggered avalanches are probable on steep wind loaded slopes. On south, southwest, and west aspects and all aspects below treeline, the danger is MODERATE. Unstable slabs are possible on steep slopes. Grand Mesa ========== Current Keywords: avalanche danger, crusts, high pressure, melt-freeze, settled, shear, stabilized, surface hoar, trough, Mountain Weather and Avalanche Forecast for the Grand Mesa Zone Forecast Issued on 12/19/2007 2:32:29 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 21-26 27-32 11-16 Wind Speed(mph) 5-15 5-15 5-15 Wind Direction WSW SW SW Sky Cover Mostly Cloudy Mostly Cloudy Overcast Snow(in) 0-2 0-2 3-5 Snowpack Discussion The snowpack in the Grand Mesa Zone has settled and stabilized since the last storm. Our forecaster in the area noted widespread 2mm surface hoar covering the snow on Tuesday. In places, this surface hoar is sitting on stiff wind crusts. This is a bad combination with a new load of snow in the forecast. Surface hoar is notoriously weak in shear and will not support a very large load before failing. Lower elevation sunny slopes likely have melt-freeze crusts, which will not bond well with new snow either. The bottom line: as the snow piles up, the avalanche danger is likely to rise as these surfaces become reactive with new load. Avalanches will likely be limited to surface snow and are not expected to step down. Be aware of changing conditions during the incoming storms. Avalanche Danger We have insufficient data to rate the avalanche danger in the Grand Mesa Zone. Please send observations from this or any other zone to [57]caic@qwest.net San Juan North ============== Current Keywords: LOW, MODERATE, avalanche danger, consolidated, cross loaded, crusts, density, drifts, faceted, facets, graupel, high pressure, powder , settled, slab, slabs, stabilizing, surface hoar, trough, wind slabs, windslab, Mountain Weather and Avalanche Forecast for the Northern San Juan Mountain Zone Forecast Issued on 12/19/2007 2:38:26 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 14-19 23-28 11-16 Wind Speed(mph) 15-25 G 30s 15-25 G 30s 15-25 G 30s Wind Direction W WSW SW Sky Cover Decreasing Increasing Overcast Snow(in) 0-2 0-2 1-3 Snowpack Discussion Reports of fresh avalanche activity in the NSJ Zone have stopped but the snow safety team at Telluride had some results on Tuesday. Their efforts pulled out a significant hard slab from north-northeast terrain above treeline that was 4' deep, 250' wide and ran 900' vertical. Local winds have been busy in the high country lately, stiffening the upper snowpack that in many areas is sitting on a well-consolidated midpack slab. Knowing that deep hard slabs are possible is a good reason to take extra caution when venturing out into high alpine terrain. Hard slab releases can be very challenging to predict: the snow underfoot can feel firm and "bomber," giving you a sense of security. However, because these slabs are so cohesive, and in many areas are sitting on top of weak faceted snow, they have the potential to be triggered from afar and often fracture above the point of initiation. Recent winds have worked around the compass and changed the upper snowpack, particularly near and above treeline. Ridgetop winds are now settled into a south-southwest flow and speeds are strong enough to transport snow on to high northerly aspects and to continue firming up the snow surface on all exposed slopes. This means that you can expect to find fresh wind slabs, drifts, and cross loaded terrain features on a variety of aspects on higher elevation slopes, as well as on exposed areas below treeline. These slabs may be reactive on steep slopes where they are sitting on low-density powder or facets. Though persistent slabs and weaknesses do exist, particularly on high northerly terrain, observers report a generally stabilizing snowpack. Backcountry travelers are tracking up a variety of aspects and slope angles without reported incidents. This is encouraging, but don't take our snowpack for granted! Another round of storms is moving through our region this week and may bring a fresh round of avalanche problems. There is quite a variety of snow surfaces on different aspects and at different elevations. From sun crusts to windslab, from near-surface facets to surface hoar and small amounts of graupel that fell recently, the incoming snow will be falling on and trying to bond with a wide array of surfaces. As snow (hopefully) piles up this week, keep getting out and enjoying the backcountry, but also stay alert to changing snowpack conditions and adhere to strict backcountry protocol - let's keep this season in the Northern San Juan Zone accident free! Avalanche Danger The avalanche danger for the Northern San Juan is MODERATE on all aspects and elevations except SE-S-SW aspects near and below treeline where the danger is LOW. Unstable slabs are possible on steep terrain. San Juan South ============== Current Keywords: LOW, avalanche danger, crown, crusts, faceting, facets, high pressure, settle, stabilize, surface hoar, trough, weak layers, Mountain Weather and Avalanche Forecast for the Southern San Juan Mountain Zone Forecast Issued on 12/19/2007 2:35:45 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 9-14 28-33 9-14 Wind Speed(mph) 5-15 G 30s 5-15 5-15 Wind Direction SW WSW SW Sky Cover Decreasing Increasing Mostly Cloudy Snow(in) 0-2 0-2 Tr-2 Snowpack Discussion Recent mild weather is helping the snowpack to settle and stabilize. However, north and easterly aspects still hold weak layers such as facets and buried surface hoar. Last weekend, a skier or snowboarder triggered a slide in the Hourglass, a NNW facing aspect near Wolf Creek Pass. The crown measured roughly 2 feet deep by 30 feet wide and was triggered under a large rock outcropping. This serves as a reminder that pockets of instability do exist. Now is a great time to enjoy conditions, but do it safely. Work into steeper terrain gradually, reevaluating the snowpack often. Low avalanche danger does not mean no avalanche danger, so make decisions accordingly. Another round of storms are forecast over the next couple of days. They are not looking all that strong. But now is the time to think about what this new snow will be falling on and how it will bond. Observers in the Purgatory area noted widespread surface hoar development on the northern half of the compass while on the southern half, angled slopes have formed surface crusts. Observers have also noted near surface faceting in cool areas. Currently, none of these layers pose a problem. However, they do tend to bond poorly with fresh snow and will become reactive with the addition of new snow load in the future. Keep this in mind as snow piles up this week. Avalanche Danger The avalanche danger is LOW on all aspects and at all elevations. There are isolated areas where you could trigger avalanches on steep slopes. You will want to examine the snowack carefully before committing to steep terrain. Sangre de Christo ================= Current Keywords: avalanche danger, cross loaded, density, drifts, facets, high pressure, powder , settle, slabs, stabilize, trough, wind slabs, Mountain Weather and Avalanche Forecast for the Sangre De Cristo Zone Forecast Issued on 12/19/2007 2:34:36 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 12-17 21-26 10-15 Wind Speed(mph) 15-25 G 30s 25-35 G 50s 25-35 G 50s Wind Direction WNW W WSW Sky Cover Decreasing Increasing Mostly Cloudy Snow(in) 0-2 0-2 0-2 Snowpack Discussion Recent mild weather helped the snowpack to settle and stabilize. Don't let this make you complacent though. Weak layers still lurk on north and easterly aspects. Strong and persistant winds have changed the snowpack, stripping snow from some areas while depositing it in others. Winds have blown from the southwest to west to north and back again. This means that you can expect to find fresh wind slabs, drifts, and cross loaded terrain features on a variety of aspects on higher elevation slopes as well as on exposed areas below treeline. These slabs may be reactive on steep slopes where they are sitting on low-density powder or facets. Work into steeper terrain gradually, reevaluating the snowpack often. Avalanche Danger We have insufficient data to rate the avalanche danger in the Sangre de Cristo Zone. Please send observations from this or any other zone to [57]caic@qwest.net Sawatch ======= Current Keywords: CONSIDERABLE, LOW, MODERATE, avalanche danger, cross loaded, crossloading, drifting, drifts, facets, high pressure, powder. , settled, slab, slabby, slabs, trough, wind drifting, wind slabs, Mountain Weather and Avalanche Forecast for the Sawatch Range Zone Forecast Issued on 12/19/2007 2:41:04 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 10-15 20-25 8-13 Wind Speed(mph) 15-25 G 40s 20-30 G 50s 15-25 G 40s Wind Direction WNW W W Sky Cover Decreasing Increasing Overcast Snow(in) 0-2 0-2 1-3 Snowpack Discussion Since our last storm over a week ago, there has been lots of drifting and transport of snow above treeline from the strong winds. It remains possible to find fresh wind slabs, sensitive drifts, and cross loaded terrain features on higher elevation slopes as well as on exposed areas near treeline. Many of the new slabs formed on top of the older, recycled powder. This strong over weak configuration can be triggered by the additional weight of a backcountry traveler, especially when you are at the slab edges. A forecaster near Monarch Pass on Monday found settled powder and recycled powder in near and below treeline areas, especially on westerly aspects. He found slabby, wind effected snow near and above treeline. North through east through south aspects were heavily loaded from strong steady winds. New snow from incoming storms will likely not bond well with any of these surfaces. Base layer facets are becoming more pronounced on high elevation, shady slopes. There remains potential to trigger large, deep avalanches in these spots. Avalanches are becoming more difficult to trigger, but the structure of the snowpack still dictates a cautious approach to backcountry travel. Use caution and sound decision making while traveling in the backcountry today. Avalanche Danger The avalanche danger is MODERATE with pockets of CONSIDERABLE on northwest, north, northeast, east, and southeast aspects above treeline. Be cautious near steep slopes that have recent wind drifting and loading. The danger is MODERATE on all aspects at treeline and other aspects above treeline. Again, watch for steep slopes with crossloading or drifting. Below treeline the danger is LOW on all aspects. Steamboat ========= Current Keywords: avalanche danger, collapsing , cross loaded, crossloaded, crusts, drifts, faceted, facets, high pressure, human triggered avalanches, powder , recrystallized, slabs, sugary, trough, whumpfing, windslabs, Mountain Weather and Avalanche Forecast for the Steamboat and Parks Range Zone Forecast Issued on 12/19/2007 2:35:11 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 14-19 22-27 6-11 Wind Speed(mph) 15-25 15-25 9-19 Wind Direction WSW WSW WSW Sky Cover Mostly Cloudy Increasing Overcast Snow(in) 1-3 1-3 2-4 Snowpack Discussion The north to west to southwest winds over the past several days moved quite a bit of snow around. Expect to find fresh windslabs, sensitive drifts, and cross loaded terrain features on exposed higher elevation slopes in the Steamboat Zone. Observers on Buffalo Pass last weekend noted lots of whumpfing as well as a couple recent avalanches. These slid below treeline on steep north facing slopes off the Camel's Hump. Steep slopes that have wind affected slabs sitting on top of sugary facets continue to be the most likely place to trigger a slide today. This combination can be found on higher elevation northwest, north, northeast, and east aspects. Watch for signs of instability, such as collapsing and cracking, while traveling in the backcountry today. Human triggered avalanches remain possible on steep slopes where slabs over lie facets. You can move from relatively stable snow, lacking the faceted basal layer, to unstable snow over a short distance. Re-evaluate the snowpack often, and practice conservative decision making. Another round of storms will move through over the next few days bringing new avalanche problems. Now is the time to think about what this new snow will be falling on and how it will bond. Surface crusts have formed on lower elevation sunny slopes while near-surface facets have formed on cooler aspects. These small, angular, recrystallized surface grains do not currently pose a problem. They are actually what we often refer to as recycled powder and make for great skiing while they remain on the surface. However, these grains tend to bond poorly and will become reactive with the addition of new snow load in the future. Keep this in mind as snow piles up this week. Avalanche Danger We have insufficient data to rate the avalanche danger in the Steamboat Zone. The most problematic areas are probably steep north, northeast, and east facing slopes that have old, weak snow underneath. Expect some crossloaded soft slabs on high elevation slopes. If you have any observations or data to share, please send them to [57]caic@qwest.net. Vail ==== Current Keywords: CONSIDERABLE, LOW, MODERATE, avalanche danger, collapse , cornice, cross loaded, crowns, density, drifted, drifts, high pressure, human triggered avalanches, natural, path, powder. , shovel, slab, slabs, start zones, trough, weak layers, wind loaded, wind loading, wind slab, wind slabs, Mountain Weather and Avalanche Forecast for the Vail and Summit County Zone Forecast Issued on 12/19/2007 3:26:05 PM Forecaster: Scott Toepfer Weather Synopsis Guess when you are third in line for storms like the Rockies, the Sierra and Wasatch get the plums, and we can sometimes get the pits. Looking at the noon satelitte images, there was a defined dry area over Summit, Eagle, Lake, and Chaffee counties. The clouds were filling in across the rest of the west slope, so still hoping for some accumulations before the end of the day. After todays weak system we'll see weak ridging/high pressure develop with a little dryer air through about mid-day Thursday. The next system seems a little slower to arrive in Colorado, more late day Thursday rather than mid-day. It first comes into the Northern 1/2 of the state on a west-south-west wind flow as the well defined trough drops south out of the Gulf of Alaska Thursday. The trough axis is slow to migrate east, possibly over Colorado Friday night, keeping us in unsettled weather into Saturday. Once again, it remains windy along the Front and Sawatch Ranges. Weather Wednesday Night Thursday Thursday Night Temperature(°F) 9-14 20-25 10-15 Wind Speed(mph) 12-22 G 30s 12-22 G 30s 10-20 G 30s Wind Direction W W WSW Sky Cover Mostly Cloudy Increasing Mostly Cloudy Snow(in) 0-2 Tr-3 2-4 Snowpack Discussion News of triggered avalanche activity continues to come in from the Summit County and Vail zone. On Tuesday a skier triggered a good sized slab on a NE aspect just below treeline near Vail. The gentleman was carried by the slab, which failed about 20 feet above him, for about 800 feet. Escape routes were not present so he had no option but to ride it out which had him buried for most of the trip, but he popped out just as the slide was coming to a stop. This ride took him over at least one 15 foot cliff. He ended up with only some impact bruises to his thigh, lost a ski, one pole, hat and goggles and his shovel was ripped off his pack. Crown was 4 feet deep at the deepest, and about 60 feet wide. This was a wind slab created from recent moderate to sometimes strong westerly winds. Another report filtered in Wednesday morning of a natural slide in the backcountry just outside Breceknridge, east aspect near treeline. We also had an observation of a couple of 1 foot crowns on a NE aspect of Northstar mountain near Hoosier Pass. These were above treeline, and not sure when they may have run. The fractures were still fairly defined, so likely in the recent past. Back on Monday a skier triggered a slide on the Little Professor slide path north of Abasin. The slide initiated on a wind loaded south aspect just below the ridge, cracking 1 to 2 feet deep. Winds have blown from the northeast, north, west, and southwest. Observers note lots of complex wind loading and some cornice collapse at ridgelines. West slopes are largely stripped while wind slabs, sensitive drifts, and cross loaded terrain features pepper most other aspects on higher elevation slopes as well as on exposed areas below treeline. Fresh slabs can be reactive on steep slopes where they are sitting on low-density recycled powder. Observers on Monday noted that fresh wind slabs 20-30cm deep were not bonding well with the underlying wind slab. Strong winds have drifted snow well down on slopes and into start zones. A fairly complex avalanche problem persists across the Vail and Summit County zone. The main ingredient found in recent activity has been the wind. Where it has blown in slab, the slab generally over lays weak layers, which have been triggered once the person has ventured well out onto the slope, a potentially troubling spot to be found as a rider. Hard to escape from these. Avalanche Danger The avalanche danger for the Vail Summit zone is MODERATE with pockets of CONSIDERABLE on north through east through south aspects above treeline. MODERATE on all aspects at treeline and LOW below treeline. Human triggered avalanches are probable above treeline on north through east through south aspects. Unstable slabs are possible on steep slopes.