Hoping that someone with a read on current conditions might be able to help with this: my 18 year old will be backpacking in Yosemite next week on a high school trip. The details are not crystal clear about where they will be camping, but the best info is that they will be spending a night or two in Curry Village, then camping at higher elevation (possibly 9000 feet, not sure about that but want him to be prepared). The question is, should he bring a 20 degree down bag (Kelty Cosmic Down) or a 0 degree synthetic bag (EMS Boreal with Primaloft insulation)? He will be using an external frame backpack so bulk is not a problem, he could just lash the big synthetic bag to the pack. The synthetic bag weights at least a couple pounds more than the down bag though; he says he is not too concerned about weight, but I'm sure that he would appreciate carrying the lighter bag if he could get away with a 20 degree bag. He will also have a wool baselayer and insulated synthetic hooded jacket that he could wear while sleeping. Thanks in adance!
