When a month is graced with two full moons, the second one is called a blue moon. You know, the once in a blue moon blue moon. The blue moon cycle is 2.72 years, making it a special, if not rare or unexpected occasion. The last blue moon month was May 2007 and the next will occur in August 2012.
Blue Moon~ December 2009....this sure looks full to me and tomorrow nights forecast is for precipitation.