owenel Posted July 8, 2011 Share Posted July 8, 2011 When climbing in the rockies you hear a lot of warnings about lightning danger, and the general advice is to get below treeline before mid-afternoon. I don't see the same warnings when reading about the cascades, or other mountain ranges like the andes or himalayas. So I assume this level of lightning danger above treeline is somewhat unique to the rockies, at least wrt the cascades. Is the main difference snow cover? Quote Link to comment Share on other sites More sharing options...
grandpa Posted July 9, 2011 Share Posted July 9, 2011 When climbing in the rockies you hear a lot of warnings about lightning danger, and the general advice is to get below treeline before mid-afternoon. I don't see the same warnings when reading about the cascades, or other mountain ranges like the andes or himalayas. So I assume this level of lightning danger above treeline is somewhat unique to the rockies, at least wrt the cascades. Is the main difference snow cover? No, it's the (relative) lack of thunderstorms. But "don't ever say never" because there are TSTMS out there, so watch the weather. Quote Link to comment Share on other sites More sharing options...
genepires Posted July 9, 2011 Share Posted July 9, 2011 I believe that a stable warm airmass is needed for a thunderhead to form. Warm air rising (much like the blobs in a lava lamp), leaving electrons on the ground to cause the potential difference and cooling in the upper atmosphere to create the classic thunderhead. I think our on shore air breezes "stirs up" the air so that there is no massive amount of hot air rising but rather lots of small rising columns. Also, I think the trees and urban development have a factor in minimizing the formation of thunderheads. I think they form on the flat grassy plains and then cause trouble when they drift over the mountains. Sierra, colorado and tetons have lots of this terrain and lightning danger. Bugaboos are surrounded by more mountains and rarely has lightning issues. But I ain't no meteorologist. I have run away from cascade summits (both rocky spires) twice with immense static charges building up which usually precursors a lightning strike. Hair standing up and pushing the helmet upwards and hearing ringing sounds. So like grandpa says, "never say never". Quote Link to comment Share on other sites More sharing options...
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