The Disparities Between Locally Developed Warm-sector Short- and
Long-term Heavy Precipitation Events Along the South China Coast:
Circulation Background and Divergence-vorticity Configuration
Abstract
The disparities in circulation backgrounds and divergence-vorticity
configurations of locally developed warm-sector short- and long-term
heavy precipitation events (SHPEs & LHPEs) are compared in this work.
Results show that double LLJs accompany the evolution of both types of
rainstorms but SHPEs are mainly located in the negative relative
vorticity (RV) area to the right of the synoptic-related LLJ, while
LHPEs are located in the positive RV area to the left side of LLJ. When
triggering, both types of rainstorms maintain the structure of bottom
convergence and lower-middle layer (875-700 hPa) divergence. Then, in
the lower-middle layer of the SHPE, the negative RH encourages the
transition from divergence to convergence, which prevents convection
from continuing, but the LHPE always retains its prior structure,
allowing it to endure longer. This work provides new insights into the
evolution of rainstorms with different durations, which can aid in the
accurate forecasting of warm-sector rainstorms.