Meet Michael Cammalleri, the unofficial meteorologist in the Canadiens' dressing room.

So as not to confuse his comrades, Cammalleri shies away from technical explanations. The weather phenomenon known as a chinook is best illustrated in practical terms.

"Let me put it to you like this," Cammalleri says. "If you're going to go for a walk downtown, you could start in a scarf, toque, gloves, five layers and a winter coat. By the end of your walk, you might just have that first-layer shirt."

Such insight could prove invaluable for the Canadiens in their preparations for the Heritage Classic Sunday at McMahon Stadium (6 p.m., CBC, RDS). The long-range forecast calls for light snow and temperatures around minus-8 Celsius.

Based on his time in Calgary during the 2008-09 hockey season, Cammalleri realizes that forecast is merely a guide. Give it an hour, give it a period, and the mercury just might rise or fall by 20 degrees.

"We could be skating through snow drifts or skating through slush," he says. "Could be cold. Might be a chinook. Who knows?"

When it comes to outdoor hockey, Cammalleri is a literal fountain of knowledge. The 28-year-old is actually one of the founding fathers of hockey in the outdoor stadium.

Some folks mistakenly believe the Edmonton Oilers pioneered the concept at the inaugural 2003 Heritage Classic against the Canadiens. In fact, they borrowed the idea from the University of Michigan-Michigan State Cold War clash in 2001.