Aspen ===== Current Keywords: CONSIDERABLE, avalanche cycle, avalanche danger, crowns, dense, drifted, natural, paths, slab, slabs, trough, windslab, windslabs, Mountain Weather and Avalanche Forecast for the Aspen Zone Forecast Issued on 1/30/2008 3:25:48 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -10 to -5 10-15 -2 to 3 Wind Speed(mph) 10-20 10-20 15-25 Wind Direction NW WSW WSW Sky Cover Decreasing Partly Cloudy Mostly Cloudy Snow(in) 1-3 0-1 0-3 Snowpack Discussion New snow did not add up to more than a couple inches in most of the Aspen Zone, with the exception of the Schofield Pass area where up to 9 inches fell over the past day and a half, as of 3 pm on Wednesday. Because this comes so quickly after our last storm, the new snow with moderate to strong westerly winds may be enough to kick us into another natural cycle on favored easterly aspects in the south western part of the zone. New snow has fallen on a snowpack that is still trying to adjust to the previous storm's load. A widespread avalanche cycle resulted from the last rapid load, with slides reported on most aspects and elevations. The majority of the slides ran on easterly aspects and many had crowns a meter to a meter and a half deep. Several slides ran as far as 2500 vertical feet. Very strong winds in the previous storm drifted snow further down slopes than usual, forming slabs lower in paths. Below treeline areas have some slab formation as well, as only the deepest darkest corners were spared in the last wind storm. Once initiated, fractures on stiff, dense windslabs have the potential to travel long distances. The new snow will disguise the slabs left behind from last weekend's windstorm. Remember that just because you cannot see the buried windslab, doesn't mean you cannot trigger it. Dig down and inspect what you are traveling on before committing to slopes steep enough to slide. Backcountry travel at this time will require advanced avalanche skills to stay safe. Stay off of and out from under steep slopes today. Large full depth avalanches remain possible in the backcountry today. Yet another layer has been added to the already touchy snowpack. Be especially aware of freshly loaded easterly aspects in near and above treeline areas. It may not take much new load to make these aspects reactive once again. Avalanche Danger The avalanche danger in the Aspen zone is CONSIDERABLE on all aspects and elevations. Look for locally higher danger in the southwest part of the zone, where more snow accumulated on Wednesday. The CAIC Aspen office needs your backcountry avalanche, weather, and snowpack observations! During storm cycles like this, these observations are very valuable and our forecaster's legs and eyes can only cover so much terrain in one day! You can help out by emailing us at caic@qwest.net with anything you see out there today. Front Range =========== Current Keywords: CONSIDERABLE, Human triggered, MODERATE, avalanche danger, collapsing , cross loaded, drifted, drifting, drifts, slab, slabs, trough, weak layers, wind loaded, windslabs, Mountain Weather and Avalanche Forecast for the Front Range Zone Forecast Issued on 1/30/2008 3:15:13 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -10 to -5 5-10 -5 to 0 Wind Speed(mph) 15-25 G/40s 15-25 20-30 G/60 Wind Direction WNW WNW W Sky Cover Overcast Partly Cloudy Mostly Cloudy Snow(in) 1-3 0 0-2 Snowpack Discussion New snow overnight Tuesday and into Wednesday only added up to added up to 3 to 5 inches as of 3 pm on Wednesday. The fresh snow will disguise the slabs left behind from last weekend's windstorm. Remember that just because you cannot see the buried windslabs, doesn't mean you cannot trigger them. Heavily loaded, cross loaded and drifted lee areas on north, through east, through south facing aspects abound. Strong winds drifted snow further down slopes than usual as well as into below treeline areas. New slabs may be sensitive to human triggering. Be especially aware of freshly loaded easterly aspects in near and above treeline areas as yet another layer has been added to the snowpack. Slides triggered over the weekend remind us that we have both deep and hard slab problems, neither of which will go away any time soon. The most recent avalanche reported occurred on Tuesday when highway crews triggered slides with mitigation work. At least one very hard slab released well below treeline on a north facing aspect. Forecasters noted that it came down largely in one big piece. Remember that hard slabs have a nasty habit of luring unwary backcountry travelers a ways onto slopes before releasing. Dig down and inspect what you are traveling on before committing to slopes steep enough to slide. Recent winds have also deposited some very thick slabs. One such slab was triggered over the weekend on Berthoud Pass, measuring 20 feet deep. It may be difficult to trigger one, but once initiated, these slides can be very large, dangerous and destructive. Remember that deep slides are often triggered from shallower, weaker areas on the slope. Smaller slides may step down, triggering older weak layers as well. New snow combined with blowing and drifting snow over the past days has added new layers to the already questionable stack. Look for obvious signs of instability including recent avalanching, shooting cracks, collapsing and strong over weak stratigraphy. Expect to find increasingly sensitive windslabs and drifts and approach all exposed slopes steeper than 30 degrees with caution. Avalanche Danger The avalanche danger in the Front Range is CONSIDERABLE on north, northeast, east, southeast and south aspects at all elevations. Otherwise the danger is MODERATE. Human triggered avalanches are probable on steep wind loaded slopes. Reactive wind slabs in the upper snowpack and deep slab instabilities continue to be our two main concerns. Grand Mesa ========== Current Keywords: cross loaded, drifts, lee , trough, windloaded, windslabs, Mountain Weather and Avalanche Forecast for the Grand Mesa Zone Forecast Issued on 1/30/2008 3:30:28 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -2 to 3 8-13 3-8 Wind Speed(mph) 0-10 0-10 10-20 Wind Direction NW NW->SW SW Sky Cover Decreasing Partly Cloudy Mostly Cloudy Snow(in) 0-2 0-1 0-2 Snowpack Discussion Our forecaster on Grand Mesa reported several slides from avalanche mitigation work on highway 65, though releases were not widespread. All slides failed only in the upper layers of the snowpack and did not step down to lower weaknesses. Eight to 10 inches of storm snow fell on Grand Mesa. Although snowfall totals did not reach anticipated amounts, wind speeds exceeded expectations. Strong south to west winds have moved snow onto exposed lee slopes where windslabs have formed on north to east to southeast aspects. Look for sensitive drifts and cross loaded areas. Weak layers existed at the old snow surface prior to the storm, so slides will likely continue to occur at the old/new snow interface. Look for changing conditions in the backcountry today as yet another layer is added to the snowpack. Be especially aware of freshly loaded easterly aspects in exposed area. Use caution on or under windloaded terrain in the backcountry today. Avalanche Danger We have insufficient data to make a danger rating for the Grand Mesa Zone. Please send observations from this or any other zone to [57]caic@qwest.net San Juan North ============== Current Keywords: CONSIDERABLE, HIGH, avalanche danger, collapsing , crown, crowns, dense, drifting, human triggered, natural, natural avalanche, slab, trough, wind drifted, wind slabs, windslabs, Mountain Weather and Avalanche Forecast for the Northern San Juan Mountain Zone Forecast Issued on 1/30/2008 4:10:40 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -10 to -5 7-12 0-5 Wind Speed(mph) 10-20 5-15 15-25 Wind Direction NW->NE variable SW Sky Cover Decreasing Partly Cloudy Increasing Snow(in) 1-3 0-1 0-3 Snowpack Discussion Six to eight inches of new snow has fallen in the San Juan as of 3 pm on Wednesday. Winds veered from southwest to northwest midday, contributing to loading and dross loading on a variety of aspects. Because we received the high end of forecasted snow amounts combined with winds speeds favorable for snow transport, we have bumped the avalanche danger to HIGH on north, northeast, east, southeast and south aspects in near and above treeline areas. New load may be enough to kick us into another natural shallow slab cycle on favored slopes. The snowpack recently took on a significant new load from the last storm, which left over 2" of water accompanied by ferocious winds. Clearing skies on Tuesday allowed observers to survey the aftermath. Avalanches ran on a variety of aspects throughout the range, though observers covering lots of terrain via helicopter on Tuesday were surprised that activity was not more widespread. However, it is likely that much of the evidence of the natural avalanche activity was covered by redistributed snow from strong winds. In any case, all reports agree on this: alpine areas have been hammered by recent winds. Several large triggered avalanches have been reported in the past two days as the result of mitigation at ski areas, local state highways and county roads. As the incoming information continues to pile up, there doesn't seem to be a particular trend in elevation or aspect. Triggered slides have run on virtually all aspects from below, near and above treeline. A majority of the avalanches ran within the upper snowpack, with crowns around 2-feet deep, but more than one avalanche was reported with a crown depth of 6 feet. Also of note, several avalanches were reported that ran full track, with one traveling up to 3000 vertical feet. Blowing and drifting snow continues to add new layers to our already tender and stacked snowpack. New snow combined with southwest to northwest winds, will load high northerly and easterly aspects. Be aware that new snow will disguise recently deposited wind slabs, so dig down to get a feel for what you are traveling on before committing to slopes steep enough to slide. Once initiated, fractures on stiff, dense windslabs have the potential to travel long distances. As you travel in the backcountry, look for obvious signs of instability including recent avalanching, shooting cracks, collapsing and hollow sounds. Use particular caution on and near firm, wind drifted convex pillows and keep in mind the possibility of releasing deep, hard slab avalanches in mind. Choose your terrain very wisely, only expose one rider at a time and have escape routes planned. Avalanche Danger The avalanche danger is HIGH on north, northeast, east, southeast and south aspects near and above treeline. It is CONSIDERABLE otherwise. Natural slides remain possible and human triggered slides are probable today. [57]Please let us know if you see any avalanche activity or experienced signs of instability. San Juan South ============== Current Keywords: CONSIDERABLE, MODERATE, avalanche cycle, avalanche danger, collapse , crown, crusts, dense, drifting, explosive, facets, human triggered, lee , slab, slabs, sluffs, surface hoar, trough, whumpfs, Mountain Weather and Avalanche Forecast for the Southern San Juan Mountain Zone Forecast Issued on 1/30/2008 4:20:49 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -5 to 0 10-15 2-7 Wind Speed(mph) 10-20 5-15 10-20 Wind Direction N variable WSW Sky Cover Decreasing Partly Cloudy Increasing Snow(in) 0-2 0 0-1 Snowpack Discussion New snow only added up to 3 to 5 inches as of 3 pm on Wednesday in the Southern San Juan Zone. Fresh snow has added yet another layer to the snowpack, especially at higher elevations where winds have transported snow onto lee slopes. The snowpack is still trying to adjust to the new load from our most recent storm, when lots of drifting, and slab formation occurred, even below treeline. Beware of recently loaded slopes, particularly on north and easterly aspects. Remember that fresh snow may disguise older hard slabs so be sure to dig down and check the bonding between layers before committing to steep slopes. Several snowcat triggered slides occurred on Tuesday north of Durango Mountain Resort. Of particular note is that the cat remotely triggered an east facing slope from a half a mile away. Our forecaster on Wolf Creek Pass noted several explosive triggered slides on easterly aspects on Tuesday though, overall surprisingly little activity given the amount of snow and wind over the past several days. One triggered slide had a section of crown that measured up to 10 feet deep, though the average crown depth was around 3 feet. This is a reminder of how quickly and deeply wind can load. Warming temperatures caused some loose sluffs and small slabs on Tuesday, though nothing very large. An observer in the La Platas noted an impressive avalanche cycle from the last storm. He noted widespread activity on all aspects below, near and above treeline with slides running even in dense trees. He also heard large "rolling whumpfs" while traveling in the backcountry today, a clear indication of collapse within the snowpack. New slabs sit atop buried surface hoar, facets or crusts in many locations. These layers serve as a poor foundation for the latest snowfall. Our main avalanche concern lies in the upper snowpack so check the bond between the old snow surface and new snow. It will take some time for the snowpack to fully adjust to the weight of the new load. Approach avalanche terrain with caution as human triggered slides remain probable. Avalanche Danger The avalanche danger is CONSIDERABLE on all aspects and elevations except for southwest, west and northwest aspects below treeline where the danger is MODERATE. Natural slides remain possible and human triggered avalanches are probable. [57]Please let us know if you see any avalanche activity or experienced signs of instability. Sangre de Christo ================= Current Keywords: avalanche danger, dense, drifted, trough, wind loaded, windslabs, Mountain Weather and Avalanche Forecast for the Sangre De Cristo Zone Forecast Issued on 1/30/2008 4:22:24 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -2 to 3 12-17 3-8 Wind Speed(mph) 20-30 15-25 25-35 Wind Direction NNW W WSW Sky Cover Decreasing Mostly Clear Partly Cloudy Snow(in) 0-2 0 0 Snowpack Discussion The Sangres have missed the bulk of the moisture from recent storms, though got more than its share of wind. While we do not know exactly how much snow accumulated in the mountains, we do know that strong winds battered the range, redistributing any snow that did fall. Expect north through east through southerly aspects to be loaded and drifted. The Sangres have a relatively shallow snowpack, capped by a variety of dense windslabs. Carefully examine the structure and stratigraphy of the snowpack before committing to slopes over 30 degrees. As always, we really like to get observations, even if it is just cloud cover and new snow from the valley floors. Avalanche Danger We have insufficient information to issue an avalanche danger for the Sangre De Christo zone. Carefully evaluate steep wind loaded slopes and be very aware of changing conditions. Please send observations from this or any other zone to [57]caic@qwest.net Sawatch ======= Current Keywords: CONSIDERABLE, avalanche danger, cross loaded, drifted, lee , natural, runout zones, slabs, trough, Mountain Weather and Avalanche Forecast for the Sawatch Range Zone Forecast Issued on 1/30/2008 4:28:36 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -8 to -3 5-10 0-5 Wind Speed(mph) 15-25 15-25 20-30 Wind Direction NW WNW W Sky Cover Decreasing Partly Cloudy Mostly Cloudy Snow(in) 0-3 0-1 1-4 Snowpack Discussion Three to five inches of snow fell by 3 pm on Wednesday in the Sawatch Zone, adding another thin layer to the already touchy snowpack. Expect to find heavily loaded, cross loaded and drifted lee areas on north, northeast, east, southeast and south facing aspects. Strong winds have drifted snow further down slopes than usual as well as into below treeline areas, creating fresh slabs, ripe for triggering. We received reports of several fresh natural slides from Friday and Saturday as well as a large snowmobile triggered slide near the summit of Cottonwood Pass on Sunday. We believe a natural cycle ran in the last storm, though have not been able to confirm this. If you venture into the backcountry, we recommend staying on low-angled terrain and avoiding avalanche runout zones. Use conservative decision making and practice strict backcountry protocols. Be especially aware of freshly loaded easterly aspects in near and above treeline areas. It may not take much new load to make these aspects reactive once again. Avalanche Danger The avalanche danger in the Sawatch Zone is CONSIDERABLE on all aspects and elevations. Use caution on freshly loaded slopes, especeially in exposed areas. [57]Please let us know if you see any avalanche activity or experienced signs of instability. Steamboat ========= Current Keywords: CONSIDERABLE, Human triggered, MODERATE, avalanche danger, slab, slabs, sluffing, stress, trough, wind slab, Mountain Weather and Avalanche Forecast for the Steamboat and Parks Range Zone Forecast Issued on 1/30/2008 3:07:21 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -3 to 2 5-10 -3 to 2 Wind Speed(mph) 10-20 15-25 10-20 Wind Direction WNW WSW WSW Sky Cover Mostly Cloudy Mostly Cloudy Mostly Cloudy Snow(in) 1-3 0-2 1-3 Snowpack Discussion While the Steamboat area missed out on the bulk of moisture from the last storm, it is getting quite a bit out of this one, receiving up to 10 to 14 inches since the Sunday. This slow loading is a generally good thing for the snowpack, not stressing it too much at one time. We have not heard of fresh avalanching since the weekend when an observer reported a skier triggered slide on a SSE aspect on Sunday. This soft slab broke 1 foot deep, 100' wide and ran 100'. Observers spotted a handful of slides up to 4 feet deep on Saturday as well. Strong southwest winds during the last storm transported a good deal of snow, especially above 9000 feet. This wind stiffened the surface, creating fresh slabs in exposed areas on north through easterly aspects. Releasing a fresh wind slab on a steep, exposed north, northeast, east, or southeast slope is the primary avalanche concern today. Watch for sluffing in the new snow today as well. Avalanche Danger The avalanche danger in the Steamboat Zone is CONSIDERABLE on north, northeast, east, southeast and south aspects near and above treeline and MODERATE otherwise. Human triggered slides are possible to probable today. If you have any observations or data to share, please send them to [57]caic@qwest.net. Vail ==== Current Keywords: CONSIDERABLE, MODERATE, avalanche danger, collapsing , cross loaded, drifted, drifting, human triggered, human triggered avalanches, lee , slab, slabs, trough, wind drifted, wind loaded, windslab, Mountain Weather and Avalanche Forecast for the Vail and Summit County Zone Forecast Issued on 1/30/2008 3:21:05 PM Forecaster: Ann Mellick Weather Synopsis Light to moderate snow has been reported statewide today, favoring the Steamboat area. Snow will continue through this afternoon as a digging trough tracks south and east across the state. Localized areas of convection may cause periods of heavy snow. This system carries good moisture, though its progressive nature will limit accumulations. The trough axis slides to our east tonight, leaving only lingering showers over the Divide. Dry northwest flow on Thursday brings a break in the snow before the next system drops into the state Thursday night into Friday. Models continue to show strong, moisture laden, westerly flow aloft, so expect a snowy weekend as a series of fast moving storms roll through. Weather Wednesday Night Thursday Thursday Night Temperature(°F) -10 to -5 3-8 -3 to 2 Wind Speed(mph) 10-20 15-25 20-30 G/50 Wind Direction NW W W Sky Cover Decreasing Partly Cloudy Mostly Cloudy Snow(in) 1-3 0 0-2 Snowpack Discussion A forecaster in the Montezuma area on Wednesday experienced lots of cracking near and above treeline on all aspects with shooting cracks on loaded south and southeast aspects. Stability tests yielded variable results depending on layering, though clean and planar sheers were found throughout. We have quite a stack of slabs out there. The bottom line is that they will be reactive to the weight of a backcountry traveler in avalanche terrain. The most likely place to trigger a slide today is on wind loaded northeast, east and southeast aspects in near and above treeline areas. The new snow has not added up to more than a few inches as of this printing though it is enough to disguise the slabs left behind from last weekend's windstorm. Remember that just because you cannot see the buried windslab, doesn't mean you cannot trigger it. Heavily loaded, cross loaded and drifted lee areas on north, through east, through south facing aspects abound. Strong winds drifted snow further down slopes than usual as well as into below treeline areas. New slabs will be sensitive to human triggering. Be especially aware of freshly loaded easterly aspects in near and above treeline areas where yet another layer has been added to the snowpack. Recent avalanche activity has involved both the newly wind loaded snow as well as deeper instabilities. Human triggered slides ran over the weekend on north, southeast and west facing slopes. All were close calls, though in the end, no one was hurt. One of the slides ran to the ground while the second person in the party skied. This is a reminder of our continued deep slab concern. This deep slab problem will not go away any time soon. It may be difficult to trigger one, but once initiated, these slides can be very large, dangerous and destructive. Remember that deep slides are often triggered from shallower, weaker areas on the slope. Blowing and drifting snow over the past days have added a new layer to the already questionable stack. Look for obvious signs of instability including recent avalanching, shooting cracks, collapsing and strong over weak stratigraphy. Use caution on and near firm, wind drifted convex pillows while keeping in mind the possibility of releasing deep, hard slab avalanches. Choose your terrain very wisely, only expose one rider at a time and have escape routes planned. Look for changing conditions with more snow and wind in the forecast. Avalanche Danger The avalanche danger in the Vail-Summit Zone is CONSIDERABLE on all aspects near and above treeline. Human triggered avalanches are probable on steep slopes, especially on northeast, east and southeast slopes near and above treeline. The avalanche danger is MODERATE on all slopes below treeline.