Slang for the province of Manitoba, Canada. A portmanteau of 'Manitoba' and 'snow', as Manitoba has a reputation for long, cold winters (as do the other Prairie provinces). Often heard together with 'Winterpeg', the slang word for its capital city (Winnipeg).
A: Where are you from?
B: Winnipeg, Manitoba.
A: Oh, Winterpeg Manisnowba? Cold enough for ya there?