SYNOPTIC-PHYSICAL IMPLICATIONS OF 1.25-CM VERTICAL-BEAM RADAR ECHOES

Abstract

More than 1000 hr of radar records taken with the APS-34 1.25-cm vertical-beam radar during a four-year period have been readily classified into four clearly recognizable types. A limited number of precipitation growth mechanisms are thereby suggested, and the echo types representing them are shown to be well correlated to three basically different classes of synoptic situations. A generalized echo cyclone model is derived. Maximum attainable hourly rates of precipitation are empirically related to the depth of detectable echo. The average vertical distance between the warm-front surface and that of the top of the radar echo above is 12,000 ft with no significant correlation. A marked increase in the frequency of precipitation echoes is found in the temperature interval −11C to −15C.