Buy a size up!
I'm usually a medium in north face, but this jacket is just a little tight and short. I'm 5'6, 140, very athletic. The jacket it tight around the back and shoulders and a little short. Perfect arm length though! Too bad they're sold out of larges.
Even though it's snug, I make it work. It is SOO warm. I love it enough to not return it!
if you decide to buy, simply go up a size!