By using non-hydrostatic mesoscale WRF (Weather Research Forecast) model, an eastward moving southwest vortex process producing heavy precipitation is simulated in high resolution. The simulation is triple nesting with the highest resolution of 5 km. The results show that the WRF model successfully simulate the area and movement of heavy precipitation caused by the southwest vortex. The southwest vortex establishes on 850 hPa firstly, and then develops upward to 700 hPa after 9 h. There is convergence, positive vorticity, potential vorticity in the lower troposphere both in newborn and mature stages of the Southwest Vortex. And the strong vertical movement, positive vorticity and potential vorticity can significantly strengthen to the upper troposphere (300 hPa). The water vapor flux divergence has good indication to strength and movement of the heavy precipitation. The potential vorticity diagnostic analysis shows that vertical configuration of the diabatic heating term is contrary to that of vertical flux divergence term. The diabatic heating term caused by the release of latent heat is beneficial to the growth of low-level potential vorticity and inhibition of the growth of high-level potential vorticity. The latent heat is in favor of the generation and development of the southwest vortex.
LIU Xiaoran
,
LI Guoping
. Numerical Simulation and Potential Vorticity Diagnosis of an Eastward Moving Southwest Vortex[J]. Plateau Meteorology, 2014
, 33(5)
: 1204
-1216
.
DOI: 10.7522/j.issn.1000-0534.2013.00151
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