AVHRR
– Advanced Very High Resolution Radiometer. Main sensor on U.S. polar orbiting satellites.
AVN
– Aviation Model generated every 12 hours by NCEP.
AWIPS
– Advanced Weather Information Processing System. New NWS computer system integrating graphics, satellite and radar imagery.
B
BACKING WINDS
– A counterclockwise change in wind direction. Backing winds with height are indicative of cold air advection (CAA).
BAROCLINICITY
– A cold air advection/warm air advection couplet that increases atmospheric instability. On analysis and forecast charts it is the isotherms crossing the height contours.
BAROTROPIC
– Homogeneous atmosphere in which there are neither fronts nor any thermal advections.
BAROMETER
An instrument for measuring atmospheric pressure.