查看文章

Comparisons are made between the characteristics of several types of rainbands observed in an extratropical cyclone and dynamical mechanisms relevant on the mesoscale.

The warm-sector flow ahead of the cold front and above the cold-frontal zone aloft was unstable to conditional symmetric instability, and theoretical predictions for this mechanism am consistent with several aspects of the warm-sector and wide cold-frontal rainbands. In the case of the warm-sector rainbands, other mechanisms (e.g., wave-CISK and mixed dynamic/convective instabilities) may have also played a role.

The core structure of the narrow cold-frontal rainbands appeared to be affected by an instability that derived its energy from the horizontal shear across the surface front. Also, many aspects of the narrow cold-frontal rainband were similar to a density current. Shear-induced gravity waves appeared to be …