Published on: December 24, 2009 at 9:36 PM

A gravity wave, or actually a big one followed by several smaller ones, is moving over central Alabama now. It is associated with the band of heavy rain on radar,and the sudden wind speed decrease. It seems that the pressure associated with the wave is pushing the air eastward, while the big storm is pulling in westward, so the winds cancel each other out! Check out the wave in the pressure trace from Tuscaloosa…