posted on Apr, 4 2011 @ 05:33 AM
dBZ stands for decibels of Z. It is a meteorological measure of equivalent reflectivity (Z) of a radar signal reflected off a remote object.[1] The
reference level for Z is 1 mm6 m−3, which is equal to 1 μm3. It is related to the number of drops per unit volume and the sixth power of drop
diameter.
Reflectivity of a cloud is dependent on the number and type of hydrometeors, which includes rain, snow, and hail, and the hydrometeors' size. A large
number of small hydrometeors will reflect the same as one large hydrometeor. The signal returned to the radar will be equivalent in both situations,
so a group of small hydrometeors is virtually indistinguishable from one large hydrometeor on the resulting radar image.
Look to the right of the map and you'll see DBZ. And it doesn't stand for Dragon Ball Z.