Shartalanche 

Severe "brown snow" weather incident. Usually accompanied by gale force winds, and heavy precipitation.

(1) James warned Chris : "If you drink any more real ale and have to visit the toilet, you will have a shartalanche on your hands ..."

(2) Pierre had eaten some bad mussels for lunch. His decision to go off-piste skiing carried a high risk of starting a shartalanche ...

Shartalanche by Fubby May 18, 2006

Shavalanche 

The act of one's rectum muscles relaxing so completely that feces flows out without any effort or control devastating all in its path like an avalanche.

ohhhh bro after eating that taco I was hit with a series of shavalanches all night long.

I got so pitted I shavalanched my pants.

Shavalanche by Shiavo August 19, 2009

scatalanche 

A powerful explosion of greasy, runny shit from your ass, such as you might have after eating 10 White Castle hamburgers.

Mikey barely made it home from White Castle, sprinting to the toilet for the scatalanche from hell.

scatalanche by VelvetB August 14, 2009

skatalanche 

like chavalanche, an attack of skateboards and baggy pants.

"aaahhh, the skateboards are coming to get me!SKATALANCHE!!!!

skatalanche by alice dude May 13, 2005