Structure and Evolution of a Slow-moving Rain-band
Xiao Meng
The three-dimensional structure and evolution of two meso-β-scale slow-
moving rain-bands are studied in detail mainly by using the data of dual Doppler-
radars. The two rain-bands were observed on Sep.16,1994 around Nagoya. Bands
were formed and maintained in the environment in which strong vertical shear
existed at low-level. They had the orientation from southeast to northwest, nearly
parallel to prevailing southeasterly winds from the surface to about 4 km, and
hardly moved in the direction mormal to the band orientation. Rain-bands were
mainly composed of several long-lasting convective-cloud groups which were
maintained by the successive formation of new convective cells at the tail portion of
the group. Most of convective-cloud groups also formed at the tail part of the rain-
band. Both convective-cloud groups and cells moved along the orientation of the
band. Most of new cells were produced at the rear of a traveling pre-existingcell,
not its right or left frank, in spite of the low-level vertical shear of normal wind
component.
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