Decoding tire size information can be a PITA. There's a veritable cacophony of letters and numbers on each one and, depending on what type of tire we're talking about, the letters and numbers can mean different things.
The wikipedia page on the subject is pretty good.
I'm a big fan of Micheline tires in general but I've recently started using Nokian
tires on all my vehicles. The Rotiva is a great A/T tire that comes in many sizes, often has an XL rating for weight and carries the severe service emblem for snow.
They can be harder to find and a little more expensive but they can also be a true all-season tire.