Silverton La Nina Email
- Thread starter ChrisC
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I got to discuss the Silverton snow issue again with Knox Williams, whom I met personally for the first time at ISSW. The Colorado Avalanche Information Center in fact has a regional satellite office in the town of Silverton. For several years CAIC measured snow where the base of the current lift is now. They found snowfall there to be almost identical to Red Mt. Pass. That site is 700 feet lower than the pass, so at comparable elevation Silverton ski area probably gets more snow but not a lot more. I've been crediting them with 10% more and Knox thinks that's a reasonable guess. No one in CAIC thinks Silverton is a freak microclimate like Wolf Creek or Buffalo Pass.
With respect to El Nino/La Nina I have preferred to correlate the monthly snowfall to the MEI index, which is maintained by Klaus Wolter, who was mentioned in the above article. The correlation of Red Mt. Pass snowfall to the MEI index is a meaningless -1% over 150 months and -14% on a seasonal basis of 29 years. However, due to the oft-theorized "on/off switch" impact of La Nina in particular, I've also tracked the months when MEI > 0.75 or < -0.75. While there is not as much data as one would like to see, the picture by this analysis is different. Red Mt. Pass has received 96% of normal snowfall in 45 El Nino months and 125% of normal snowfall in 22 La Nina months. FYI Telluride has received 92% of normal snowfall in 40 El Nino months and 117% of normal snowfall in 22 La Nina months. This data conforms to a recent statement by ChrisC that "Telluride is favored by a NW flow."
It is very rare for the latter analysis to exceed 100% for both El Nino and La Nina with much data. One of those noteworthy exceptions is the Whistler Roundhouse at 110% in 44 El Nino months and 119% in 26 La Nina months.
With respect to El Nino/La Nina I have preferred to correlate the monthly snowfall to the MEI index, which is maintained by Klaus Wolter, who was mentioned in the above article. The correlation of Red Mt. Pass snowfall to the MEI index is a meaningless -1% over 150 months and -14% on a seasonal basis of 29 years. However, due to the oft-theorized "on/off switch" impact of La Nina in particular, I've also tracked the months when MEI > 0.75 or < -0.75. While there is not as much data as one would like to see, the picture by this analysis is different. Red Mt. Pass has received 96% of normal snowfall in 45 El Nino months and 125% of normal snowfall in 22 La Nina months. FYI Telluride has received 92% of normal snowfall in 40 El Nino months and 117% of normal snowfall in 22 La Nina months. This data conforms to a recent statement by ChrisC that "Telluride is favored by a NW flow."
It is very rare for the latter analysis to exceed 100% for both El Nino and La Nina with much data. One of those noteworthy exceptions is the Whistler Roundhouse at 110% in 44 El Nino months and 119% in 26 La Nina months.
Glad you posted this! I got this a few days ago and have been to busy to post.
Tony-please report back to us after you discuss this again. Also please clarify whether you are talking about snow at the base or mid mountain or top. Mid mountain is generally where most resorts report correct (not Jackson). Also discuss that Silverton has a lot of terrain above top of lift and how snow depths are factored up there.
Tony-please report back to us after you discuss this again. Also please clarify whether you are talking about snow at the base or mid mountain or top. Mid mountain is generally where most resorts report correct (not Jackson). Also discuss that Silverton has a lot of terrain above top of lift and how snow depths are factored up there.
In my regional tables I always post elevation where snow is measured. As to where ski areas measure, that's highly variable. Ski patrol/snow safety people do want to measure accurately, so that constrains some ski areas where upper terrain is too wind exposed, like Mammoth, Bachelor and Snowbird. In Colorado the tree line is very high and most areas measure close to 11,000 feet, which can be 2/3 or 3/4 of the way up the lift served elevation range.
There are areas where base elevation snowfall is much less than typical ski terrain. I doubt Silverton is one of them as its base is 10,400. Data is nearly always more limited than we would like. Within an area it's best to observe the mid-season snowpack to see if it's radically different from top to mid to bottom. Just because snowfall increases significantly going from 9,000 to 11,000 does not mean it continues to increase at the same rate going from 11,000 to 13,000. Looking at snow depth at many places in Colorado one might question whether snowfall increases much at all above 11,000.
it's also illuminating to observe snowpack vs. different areas within a similar overall climate zone. In Silverton's region that would be Wolf Creek. If you compare Wolf Creek's snowpack to Silverton's it's hard not to conclude that Silverton's snow average is significantly less. That's not to say it's bad, but it's not 400 inches either, even up high.
Snowfall and snow conditions can be separate issues. Low skier density and high, steep, north-facing terrain at Silverton probably yields far superior conditions to Colorado's lift service much of the time.
There are areas where base elevation snowfall is much less than typical ski terrain. I doubt Silverton is one of them as its base is 10,400. Data is nearly always more limited than we would like. Within an area it's best to observe the mid-season snowpack to see if it's radically different from top to mid to bottom. Just because snowfall increases significantly going from 9,000 to 11,000 does not mean it continues to increase at the same rate going from 11,000 to 13,000. Looking at snow depth at many places in Colorado one might question whether snowfall increases much at all above 11,000.
it's also illuminating to observe snowpack vs. different areas within a similar overall climate zone. In Silverton's region that would be Wolf Creek. If you compare Wolf Creek's snowpack to Silverton's it's hard not to conclude that Silverton's snow average is significantly less. That's not to say it's bad, but it's not 400 inches either, even up high.
Snowfall and snow conditions can be separate issues. Low skier density and high, steep, north-facing terrain at Silverton probably yields far superior conditions to Colorado's lift service much of the time.