I'll be doing the Whitney Portal to summit trek in mid-August and have been thinking about my clothing system, particularly a mid-layer. The temps have been 42-57 on the mountain lately, with little threat of inclimate weather. My plan thus far:
1. Ibex wool crew long sleeve baselayer
2. Nylon hiking pants (likely convertible to shorts).
3. Montbell Peak shell (in pack)
My question is what you would recommend as a light, breathable insulation layer should I need it for warmth without rain? Or, would the Peak Shell with its pit zips suffice?
I also have a Montbell UL Thermawrap which I will bring but if the weather stays consistent as it has been think it will be too warm and thus might leave at base camp.
Any advice on the matter would be appreciated.

