By all accounts, Mount Kelud eruption was big

Though Sinabung's pyroclastic flows have been garnering media attention for several weeks, that particular eruption got overshadowed (almost literally) by an unexpected and large blast from Mount Kelud.  The satellite picture was really impressive:

Satellite picture of Mount Kelud eruption cloud

The pictures from the ground are pretty impressive, too.

What it looks like when a volcano sends ash 55,000 feet into the air

Big enough for climate effects (which would be cooling)?  Only time will tell. 

Impressive night picture of eruption cloud with lightning