Aspen ===== Current Keywords: LOW, avalanche hazard, crusts, entrained, faceted, human triggered, trough, wind loading, Mountain Weather and Avalanche Forecast for the Aspen Zone Forecast Issued on 11/25/2007 3:18:52 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 12-17 25-30 12-17 Wind Speed(mph) 5-15 10-20 G30 10-20 G30 Wind Direction W WNW WSW Sky Cover Mostly Cloudy Mostly Cloudy Partly Cloudy Snow(in) 0 0-1 0 Snowpack Discussion Friday's light snow brought ½ to 1 inch of accumulation around the Aspen Zone, not enough to change avalanche conditions. The snowpack can best be described as shallow and highly variable from one slope to the next. There is however enough snow to be thinking about avalanches. Persistent winds from the west on Saturday have created the deepest snowpack on higher elevation slopes facing north through east. On these aspects you will find the recent storm snow in the upper snowpack with older snow from October below. The lower layers in the snowpack are made up of either weak faceted snow or crusts depending on what aspect you are on. If you are traveling on these higher elevation shady aspects, be sure and check the bond between all these layers. At lower elevations and on sunnier slopes, there is only a patchy older snowpack or bare ground under our most recent storm snow. This shallow snowpack with its buried rocks, stumps, and trees will be a bigger hazard than avalanches. It is not too early for avalanches! As [59]an early season avalanche reminder, our first human triggered avalanche occurred on November 14th. New snow during the next 24 hours is not expected to change the avalanche hazard. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger Avalanche danger in the Aspen Zone is rated an overall LOW. Please remember that at a LOW rating it is still possible to see avalanche activity. Keep an eye out for any areas above treeline that have seen recent wind loading. If you are traveling in the backcountry this holiday weekend, we would love to know what you are seeing. Observations for the Aspen Zone, or any other area, can be sent to [60]caic@qwest.net . Front Range =========== Current Keywords: LOW, MODERATE, avalanche danger, avalanche hazard, crown, drifted, entrained, human triggered, natural, slab, slabs, trough, Mountain Weather and Avalanche Forecast for the Front Range Zone Forecast Issued on 11/25/2007 3:16:15 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 12-17 23-28 12-17 Wind Speed(mph) 10-20 G35 15-25 G45 15-25 G40 Wind Direction WNW WNW WSW Sky Cover Mostly Cloudy Mostly Cloudy Partly Cloudy Snow(in) 0 0-1 0 Snowpack Discussion Roughly a half a foot of new snow fell in most areas of the Front Range Zone mid-week. This added up to just enough new snow to freshen up the existing snow patches and hide shallowly buried obstacles. Persistent winds from the west were reported on Saturday that built up some soft slabs on east aspects near and above treeline. An observer on Rollins Pass noted some recent natural activity including an R2-D2 at 11,300' on an ESE aspect and running for 200'. It started on a convex roll near a rocky outcropping with a 30 cm crown and 50 m wide. Similar activity was also reported near Loveland Pass. Further north, another observer near Cameron Pass noted no recent slide activity. Shallow avalanche possibilities remain. Good rideable terrain is still a little tough to find in quantity, but we are slowly building a foundation. The old snow is mostly stable, meaning avalanche problems will be limited to the new snow. Watch for pockets of drifted snow on steep slopes. If the terrain looks well covered in snow, it probably has enough snow to hide a slab. Carefully evaluate the bond between the new and old snow. Look at the consequences of any ride. Rocks hurt. As [59]an early season reminder, our first human triggered avalanche occurred on November 14th. New snow during the next 24 hours is not expected to change the avalanche hazard. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger There are pockets of MODERATE avalanche danger on steep north, northeast, and east aspects above treeline. Otherwise the avalanche danger is LOW. Grand Mesa ========== Current Keywords: LOW, avalanche danger, entrained, trough, Mountain Weather and Avalanche Forecast for the Grand Mesa Zone Forecast Issued on 11/25/2007 3:20:00 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 18-23 27-32 18-23 Wind Speed(mph) 0-10 5-15 0-10 Wind Direction WNW NW SW Sky Cover Increasing Decreasing Mostly Clear Snow(in) 0 0 0 Snowpack Discussion Grand Mesa picked up 6 inches of new snow from the past mid-week storm. Areas of patchy snow could be found prior to the storm though there is still too little snow to pose much of an avalanche danger. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger The avalanche danger for the Grand Mesa zone is LOW. If you have observations from this area, or any other, please send them to [59]caic@qwest.net San Juan North ============== Current Keywords: LOW, MODERATE, avalanche danger, entrained, faceted, slab, slabs, trough, Mountain Weather and Avalanche Forecast for the Northern San Juan Mountain Zone Forecast Issued on 11/25/2007 3:20:36 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 18-23 25-30 15-20 Wind Speed(mph) 0-10 5-15 0-10 Wind Direction N NW SSW Sky Cover Increasing Decreasing Mostly Clear Snow(in) 0 0 0 Snowpack Discussion Snow total reports from Friday's storm ranged from 4"-11" for the Northern San Juan Zone. Most of the snow during this storm fell with winds blowing from the south-southwest that were strong enough to transport new snow. As a result, northerly slopes in the high country got some decent loading. On Saturday, strong winds shifted to the northeast. Drifts up to a meter deep have formed along ridges and have created some soft slab. Near Telluride, an observer noted a small soft slab slide in the Mammoth Fingers on a N aspect near 11,800'. Fresh slabs on a variety of aspects near and above treeline now sit on either faceted, cohesionless snow or fairly slick wind-affected surface snow with which the new slab may struggle to bond. Small human triggered slides are possible are possible on steep slopes with built-up snow. Remember that even a small slide can drag you across rocks and other obstacles. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger The avalanche danger in the Northern San Juan Zone is generally LOW, but on NW-N-NE aspects that are 35 degrees or steeper the hazard is MODERATE. Be careful of tender new slabs on high northerly slopes, as well as thinly covered trees, rocks and other "obstacles." If you have observations from this area, or any other, please [59]Submit an Observation. San Juan South ============== Current Keywords: LOW, avalanche danger, entrained, faceted, trough, Mountain Weather and Avalanche Forecast for the Southern San Juan Mountain Zone Forecast Issued on 11/25/2007 3:21:13 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 20-25 32-37 17-22 Wind Speed(mph) 5-15 5-15 0-10 Wind Direction NW WNW SW Sky Cover Partly Cloudy Partly Cloudy Mostly Clear Snow(in) 0 0 0 Snowpack Discussion There was limited snow cover throughout the Southern San Juan zone before Fridays storm. New snow Friday fell mainly on bare ground. Consequently avalanche danger has not gone up much, if at all yet. We are starting to build that early season base now. If we return to the typical Colorado winter, much of this new snow will alter from the nice stellar snow flake to the weaker faceted sugar like snow. This bears watching as it could be a problem as we work further into winter. Getting into the backcountry will still be a little tricky, with rocks and other hidden treasures lurking just underneath the new snow. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger The avalanche danger in the Southern San Juan zone is LOW. Sangre de Christo ================= Current Keywords: LOW, avalanche danger, crust, drifts, entrained, stabilize, start zones, trough, Mountain Weather and Avalanche Forecast for the Sangre De Cristo Zone Forecast Issued on 11/25/2007 3:22:14 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 20-25 30-35 17-22 Wind Speed(mph) 5-15 10-20 5-15 Wind Direction NW WNW SW Sky Cover Partly Cloudy Partly Cloudy Mostly Clear Snow(in) 0 0 0 Snowpack Discussion 3-4" of new snow was reported from the southern end of the Sangres Saturday morning. For the season so far, there has been limited snow cover throughout the Sangre de Cristo zone. Shaded areas above 11,000' have the most snow. The winds have built some smooth rounded drifts that are a couple of feet deep, but they present little danger at this time. Time and warm temperatures have helped to stabilize the small amounts of snow in avalanche start zones. Most sun-exposed aspects have little or no snow cover, but where this is snow, a hard melt freeze crust has developed. The areas that have some snow cover now will present the greatest danger as the new snow from Friday and Friday night see a little wind re-distribution. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger The avalanche danger in the Sangre de Cristo zone is LOW. Remember, LOW does not mean avalanches are impossible. Sawatch ======= Current Keywords: LOW, avalanche danger, entrained, human triggered, slab, slabs, trough, wind loaded, Mountain Weather and Avalanche Forecast for the Sawatch Range Zone Forecast Issued on 11/25/2007 3:22:54 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 15-20 25-30 13-18 Wind Speed(mph) 5-15 10-20 G30 10-20 G30 Wind Direction WNW W W Sky Cover Increasing Decreasing Mostly Clear Snow(in) 0 0 0 Snowpack Discussion Two or more new inches fell throughout the zone Friday and Friday night. Persistent winds from the west on Saturday moved some of this new snow to fill in gullies on north through east aspects above tree line. Tender slabs can be found in these isolated pockets which for the most part are the areas one would look for to ride. If you choose to ride, be aware of the snow stability in these areas, approaching with caution. Observers have confirmed there are soft slab conditions on east aspects above treeline, and slide activity has been reported above treeline on east aspects in the Vail/Summit and Front Range zones. Our most likely injury with our current snowpack would be bodily or to our equipment. It is not too early for avalanches! As [59]an early season avalanche reminder, our first human triggered avalanche occurred on November 14th. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger The avalanche danger is currently rated as LOW. Be cautious near all wind loaded aspects above tree line facing north through east as well as steep gullies. Steamboat ========= Current Keywords: LOW, avalanche danger, avalanche hazard, drifts, entrained, trough, Mountain Weather and Avalanche Forecast for the Steamboat and Parks Range Zone Forecast Issued on 11/25/2007 3:15:33 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 10-15 27-32 12-17 Wind Speed(mph) 10-20 15-25 15-25 Wind Direction W WNW WSW Sky Cover Mostly Cloudy Mostly Cloudy Partly Cloudy Snow(in) 0-1 0-1 0 Snowpack Discussion No new reports of snowfall reported since Wednesday. Prior to the storm, only patchy areas of older snow persisted in shaded areas above 11,000'. Although new snow from mid-week fell on limited snow cover, the trained eye can probably find fresh shallow drifts on top of the old snow. You might be able to find some isolated spots to trigger the new drifts, though you would have to hunt for them on steep slopes. It is not too early for avalanches! Our season's first reported skier-triggered avalanche is [59]an early season avalanche reminder. New snow during the next 24 hours is not expected to change the avalanche hazard. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger The avalanche danger in the Steamboat zone is LOW. Vail ==== Current Keywords: LOW, MODERATE, avalanche danger, avalanche hazard, crowns, entrained, human triggered, slabs, trough, wind loaded, Mountain Weather and Avalanche Forecast for the Vail and Summit County Zone Forecast Issued on 11/25/2007 3:16:50 PM Forecaster: John Snook Weather Synopsis An approaching trough from the northwest will slide across northern Colorado later tonight into Monday morning. Clouds will increase after midnight over the northern and central mountains. Periods of light snow are expected by daybreak with up to an inch of snow by midday. Clearing skies return for late Monday into Tuesday morning with strong winds east of the Continental Divide. The jet stream continues to slowly sag south on Tuesday ahead of a more significant trough scheduled to arrive late Tuesday. The computers models are still not in agreement, but I am favoring the moister model as the satellite imagery suggests decent moisture available to the southwest that can get entrained into the system. This scenario indicates up to a foot or more of snow by Wednesday afternoon for the southern and central mountains, and lesser amounts for the northern mountains. A broad long-wave trough is suggested for later in the week across the west with another chance for mountain snow on Friday into Saturday, also favoring the southwest mountains. Weather Sunday Night Monday Monday Night Temperature(°F) 12-17 22-27 10-15 Wind Speed(mph) 10-20 G30 10-20 G40 10-20 G30 Wind Direction W WNW WSW Sky Cover Mostly Cloudy Mostly Cloudy Partly Cloudy Snow(in) 0 0-1 0 Snowpack Discussion Persistent winds from the west on Saturday have transported the new snow from mid-week onto east aspects. Several observers noted slide activity above Pass Lake, just south of Loveland Pass. Details are sketchy at this time, but one slide was likely human-triggered and may have caught someone. The noted activity occurred above treeline on steep easterly aspects with crowns of 1-3' deep within the new snow layer. Much of the new snow has been transported to fill in gullies on North through East aspects above tree line. Tender slabs can be found in these isolated pockets. For the most part, these are the areas one would look for to ride. If you choose to ride, be prepared to test the snow stability on the slope in question before jumping in with a full commitment. The most likely injuries if caught in a slide under our current conditions would be from rocks and other terrain features, not to mention what happens to the new toys we're on. It is not too early for avalanches! As [59]an early season avalanche reminder, our first human triggered avalanche occurred on November 14th. New snow during the next 24 hours is not expected to change the avalanche hazard. Now is a good time to be practicing up on your backcountry skills, including safe route selection and evaluating local snowpack stability. With more snow in the long-range forecast, it will not be long before these skills will be essential. Avalanche Danger There are pockets of MODERATE avalanche danger on steep north, northeast, and east aspects above treeline where wind loaded soft slabs may exist. Otherwise the avalanche danger is LOW.