It’s not everyday that radar actually detects a cold front by air temperature and not by clouds or rain. But that is the case today. If you watch the radar loop above, you’ll notice the area of light reflectivity mainly NW of the radar in Calera. That’s not rain, nor clouds. It’s actually called anomalous propagation, a situation where the shallow cold front is actually bending the radiation from the radar down to the ground, sort of like when you put a pencil in a glass of water and the light rays bend. The radiation is bouncing off the ground, back to the radar, making the radar think there are bugs, raindrops, etc. out there. Neat.
