Quote Originally Posted by Rybir View Post
holy
smokes.
Holy smokes WHAT? You'll be 4 weeks into your hike before that first date shown, hopefully you'll be through the Sierra and into lower ground in late October/early November.

I'd go with the layering thing, keep the flash jacket. I currently take a double-layer outer shell in "shoulder seasons" and a lighter down insulating layer than usual. My double layer outer shell is an OR Helium II jacket at 6.5 ounces, coupled with a Dri-Ducks (AKA Frogg Togg) UL rain jacket at 5.5 ounces, total of 12 ounces, the double layer traps an additional layer of air, and those two jackets over a UL down sweater/jacket (and below that, a microfleece over a smartwool base) makes for excellent warmth, down to well below freezing for camp. Very versatile having so many layers.