摘要
[Objective] The study aims at analyzing a regional rainstorm in Yulin City of northern Shaanxi. [Method] Based on conventional meteorological data, satellite cloud pictures and ncep 1 ° ×1 ° reanalysis products, a regional rainstorm occurring during July 1 -3, 2011 in Yulin City of northern Shaanxi was discussed from the aspects of circulation pattem, mesoscale system, water vapor and dynamical conditions.[Result] There was a small closed high-pressure center near Fujian, around which southwest air flow existed constantly, providing water vapor for rainstorm areas for a long time; plateau trough moved eastwards, which provided dynamical field for rainstorm areas; the convergence between northeast cold air and low-level jet flow triggered this rainstorm; rainstorm areas were closely related to mesoscale low-pressure, and the storm appeared in the lowlevel jet flow in front of mesoscale low pressure; upper-trough cloud system and low-level jet cloud system combined, increased and generated rainstorm cloud cluster, while brightness temperature on the top of clouds was below -90 ℃ [ Conclusion] The research could provide theoretical foundation for forecast of rainstorms in future.
[Objective] The study aims at analyzing a regional rainstorm in Yulin City of northern Shaanxi. [Method] Based on conventional meteorological data, satellite cloud pictures and ncep 1 ° ×1 ° reanalysis products, a regional rainstorm occurring during July 1 -3, 2011 in Yulin City of northern Shaanxi was discussed from the aspects of circulation pattem, mesoscale system, water vapor and dynamical conditions.[Result] There was a small closed high-pressure center near Fujian, around which southwest air flow existed constantly, providing water vapor for rainstorm areas for a long time; plateau trough moved eastwards, which provided dynamical field for rainstorm areas; the convergence between northeast cold air and low-level jet flow triggered this rainstorm; rainstorm areas were closely related to mesoscale low-pressure, and the storm appeared in the lowlevel jet flow in front of mesoscale low pressure; upper-trough cloud system and low-level jet cloud system combined, increased and generated rainstorm cloud cluster, while brightness temperature on the top of clouds was below -90 ℃ [ Conclusion] The research could provide theoretical foundation for forecast of rainstorms in future.
