By using the data in Hubei automatic rainfall station and NCEP 1°×1° global reanalysis data,the vertical helicity analysis on the rainstorm weather process which happened in Hubei Province during June 2...By using the data in Hubei automatic rainfall station and NCEP 1°×1° global reanalysis data,the vertical helicity analysis on the rainstorm weather process which happened in Hubei Province during June 28-30 in 2009 was done.The results showed that the spatial and temporal evolution characteristic of vertical helicity could reflect well the occurrence time and the falling zone of strong precipitation in the situation that the strong vertical ascent movement in the whole layer stably maintained.The distribution of 700 hPa vertical helicity gradient big value area which was 6 h interval and the ∑θse(500+700+850) horizontal energy frontal zone superposition area both had the good directive significance for the falling zone of 6 h heavy precipitation.The zone where the heavy precipitation appeared had the configuration of positive vertical helicity in the low layer and the negative vertical helicity in the high layer.When the positive vertical helicity in the low layer was slightly higher than the negative vertical helicity in the high layer,it favored the generation of heavy rainstorm center.展开更多
[Objective]The aim was to analyze the first fit of rainstorm in southeast Hubei on June 9,2011.[Method]GFS reanalysis data with resolution 0.5°×0.5°,routine-observational data,the intensive observations...[Objective]The aim was to analyze the first fit of rainstorm in southeast Hubei on June 9,2011.[Method]GFS reanalysis data with resolution 0.5°×0.5°,routine-observational data,the intensive observations of automatic weather station data,satellite image as well as satellite image were used in the analysis for the process of a heavy rain on June 9-10,2011 during Meiyu in Hubei province.[Result]The heavy rainfall occurred under the favorable environmental conditions,but the single-obstruction situation during Meiyu was different from the typical double-obstruction one.The affecting systems were the trough at 45° N on 500 hPa caused the systems moving slowly in the middle and low troposphere.The strong convergence of water vapor and conditional convective instability were provided from the shear line on 700 and 850 hPa,the southwest jet flow and dry lines in the middle and low troposphere for heavy rainfall.Three rain clusters which brought heavy rainfall had the features of meso-scale β system,which came from warm and humid airflow,the tail of shear line on 700 hPa and the head of shear line on 850 hPa.Through convergence and strengthening in southeast region of Hubei Province,the ribbon structure from northeast to southwest was formed to maintain the meso-scale β system.The cloud was the direct producer of precipitation.Heavy rainfall occurred in strengthening phase of strong convection zone on Tongcheng city.[Conclusion]The study provided theoretical reference for the report of rainstorm during Meiyu period.展开更多
文摘By using the data in Hubei automatic rainfall station and NCEP 1°×1° global reanalysis data,the vertical helicity analysis on the rainstorm weather process which happened in Hubei Province during June 28-30 in 2009 was done.The results showed that the spatial and temporal evolution characteristic of vertical helicity could reflect well the occurrence time and the falling zone of strong precipitation in the situation that the strong vertical ascent movement in the whole layer stably maintained.The distribution of 700 hPa vertical helicity gradient big value area which was 6 h interval and the ∑θse(500+700+850) horizontal energy frontal zone superposition area both had the good directive significance for the falling zone of 6 h heavy precipitation.The zone where the heavy precipitation appeared had the configuration of positive vertical helicity in the low layer and the negative vertical helicity in the high layer.When the positive vertical helicity in the low layer was slightly higher than the negative vertical helicity in the high layer,it favored the generation of heavy rainstorm center.
文摘[Objective]The aim was to analyze the first fit of rainstorm in southeast Hubei on June 9,2011.[Method]GFS reanalysis data with resolution 0.5°×0.5°,routine-observational data,the intensive observations of automatic weather station data,satellite image as well as satellite image were used in the analysis for the process of a heavy rain on June 9-10,2011 during Meiyu in Hubei province.[Result]The heavy rainfall occurred under the favorable environmental conditions,but the single-obstruction situation during Meiyu was different from the typical double-obstruction one.The affecting systems were the trough at 45° N on 500 hPa caused the systems moving slowly in the middle and low troposphere.The strong convergence of water vapor and conditional convective instability were provided from the shear line on 700 and 850 hPa,the southwest jet flow and dry lines in the middle and low troposphere for heavy rainfall.Three rain clusters which brought heavy rainfall had the features of meso-scale β system,which came from warm and humid airflow,the tail of shear line on 700 hPa and the head of shear line on 850 hPa.Through convergence and strengthening in southeast region of Hubei Province,the ribbon structure from northeast to southwest was formed to maintain the meso-scale β system.The cloud was the direct producer of precipitation.Heavy rainfall occurred in strengthening phase of strong convection zone on Tongcheng city.[Conclusion]The study provided theoretical reference for the report of rainstorm during Meiyu period.
