Is it a fancy name for avalanche? If so, we have those here too. I don't imagine the word 'avalanche' grabs peoples fancy quite as much as 'tsunami' following what happened at Christmas.
Kinda like how after 9/11/01, every criminal was labelled a terrorist. I even remember reading an article about some politician calling vandals 'terrorists' because they tagged neighborhoods, or something equally asinine.
Want to get your bill passed? Say it fights terrorism. Wanna get your byline published by the AP? Refer to an avalanche or blizzard as a 'snow tsunami'.