It is important for predictions of heavy rainfall to include radar data to provide better reflection of moisture. Numerical experiments were carried out with real cases of heavy rains in the Changjiang (Yangtze)-Huaih...It is important for predictions of heavy rainfall to include radar data to provide better reflection of moisture. Numerical experiments were carried out with real cases of heavy rains in the Changjiang (Yangtze)-Huaihe River Basin using a PSU/NCAR mesoscale model that incorporated radar data. Processed radar data were added to the model to change the analysis of initial humidity field before 24-h numerical simulations were made and the results compared with a control experiment. It is suggested that the radar-data-incorporated numerical predictions could produce locations of precipitation areas and maximum rainfall that are closer to reality than the control, due to the fact that moisture and converging updraft are strengthened in the middle and lower levels of the troposphere in the area of heavy rains and areas nearby. The work is expected to improve numerical modeling and forecasts of heavy rains in middle and lower latitudes of China.展开更多
[Objective] The research aimed to analyze a turning weather process in Binzhou City of Shandong Province in midsummer of 2010.[Method] Started from the short-term forecast ideas,the formation reason of heavy or torren...[Objective] The research aimed to analyze a turning weather process in Binzhou City of Shandong Province in midsummer of 2010.[Method] Started from the short-term forecast ideas,the formation reason of heavy or torrential rain and local heavy rainstorm in Binzhou City during 4-5 August,2010 was analyzed from the circulation situation,physical quantity field,radar echo and so on.[Result] The westerly trough and cold air were the trigger mechanisms of precipitation.The warm wet air flow at the edge of subtropical high and the high-altitude low trough were the main systems of precipitation.It was the typical precipitation process that the northwest of subtropical high overlapped with the westerly trough.In the prior period,the high temperature continued.The cold air at 500 hPa made the convection strengthen.It was the main reason that the local precipitation was strong.In the forecast of rainstorm,the specific humidity,K index and SI index were the good physical quantities and reference indexes.In the formation process of rainstorm,K index had the increasing process.When the rainstorm finished,or the rain intensity weakened,K index decreased obviously.SI index indicated the development of convective precipitation.The radar echo analysis found that the mesocyclone appeared in the process for a short time.For it weakened quickly and disappeared in the shift process,the strong precipitation and gale were formed in the west of Binzou,but the hail wasn’t generated.[Conclusion] The research provided the experience for the forecast of such weather in future.展开更多
[Objective] The aim was to analyze radar echo characteristic of a heavy rainstorm in central Guangxi in June, 2010. [Method] Using conventional observations and automatic stations, Doppler radar and other data, a seve...[Objective] The aim was to analyze radar echo characteristic of a heavy rainstorm in central Guangxi in June, 2010. [Method] Using conventional observations and automatic stations, Doppler radar and other data, a severe rainstorm in central of Guangxi which occurred on 31 May to 1 June 2010 was analyzed. The characteristics of weather radar data were analyzed to reveal the characteristics of radar echo during the heavy precipitation process. [ Result] The heavy rainstorm had gone through many singular wind storms towards MCS variation. The existence of ultra-sin- gular and ＂train effect＂ was the main reason of the heavy rainstorm. The results showed that during the heavy rainfall experienced an evolution process from multi-cell storm to MCS, and found that super cell and the ＂train effect＂ was the major reason which caused this torrential rain. The echo centroid of multi-cell storm stretching along its moving reverse order was the key factor which maintained the heavy rain. Analysis also found that the average echo intensity had a good relationship with rainfall. Strong echoes were in quasi-stationary state for a long time and was favorable heavy rain. In the diameter velocity diagram, mesoscale convergence line, the adverse wind regions and the mid-cyclone were the important basis to determine producing and keeping heavy rainfall. Radar wind profile can reflect the configuration of layers of wind conditions, and it was an effective tool to determine whether the trough was in transition or not. [ Conclusion] The study provided reference for the short-term and nowcasting report.展开更多
基金A project of the Natural Science Foundation of China (49794030)
文摘It is important for predictions of heavy rainfall to include radar data to provide better reflection of moisture. Numerical experiments were carried out with real cases of heavy rains in the Changjiang (Yangtze)-Huaihe River Basin using a PSU/NCAR mesoscale model that incorporated radar data. Processed radar data were added to the model to change the analysis of initial humidity field before 24-h numerical simulations were made and the results compared with a control experiment. It is suggested that the radar-data-incorporated numerical predictions could produce locations of precipitation areas and maximum rainfall that are closer to reality than the control, due to the fact that moisture and converging updraft are strengthened in the middle and lower levels of the troposphere in the area of heavy rains and areas nearby. The work is expected to improve numerical modeling and forecasts of heavy rains in middle and lower latitudes of China.
文摘[Objective] The research aimed to analyze a turning weather process in Binzhou City of Shandong Province in midsummer of 2010.[Method] Started from the short-term forecast ideas,the formation reason of heavy or torrential rain and local heavy rainstorm in Binzhou City during 4-5 August,2010 was analyzed from the circulation situation,physical quantity field,radar echo and so on.[Result] The westerly trough and cold air were the trigger mechanisms of precipitation.The warm wet air flow at the edge of subtropical high and the high-altitude low trough were the main systems of precipitation.It was the typical precipitation process that the northwest of subtropical high overlapped with the westerly trough.In the prior period,the high temperature continued.The cold air at 500 hPa made the convection strengthen.It was the main reason that the local precipitation was strong.In the forecast of rainstorm,the specific humidity,K index and SI index were the good physical quantities and reference indexes.In the formation process of rainstorm,K index had the increasing process.When the rainstorm finished,or the rain intensity weakened,K index decreased obviously.SI index indicated the development of convective precipitation.The radar echo analysis found that the mesocyclone appeared in the process for a short time.For it weakened quickly and disappeared in the shift process,the strong precipitation and gale were formed in the west of Binzou,but the hail wasn’t generated.[Conclusion] The research provided the experience for the forecast of such weather in future.
文摘[Objective] The aim was to analyze radar echo characteristic of a heavy rainstorm in central Guangxi in June, 2010. [Method] Using conventional observations and automatic stations, Doppler radar and other data, a severe rainstorm in central of Guangxi which occurred on 31 May to 1 June 2010 was analyzed. The characteristics of weather radar data were analyzed to reveal the characteristics of radar echo during the heavy precipitation process. [ Result] The heavy rainstorm had gone through many singular wind storms towards MCS variation. The existence of ultra-sin- gular and ＂train effect＂ was the main reason of the heavy rainstorm. The results showed that during the heavy rainfall experienced an evolution process from multi-cell storm to MCS, and found that super cell and the ＂train effect＂ was the major reason which caused this torrential rain. The echo centroid of multi-cell storm stretching along its moving reverse order was the key factor which maintained the heavy rain. Analysis also found that the average echo intensity had a good relationship with rainfall. Strong echoes were in quasi-stationary state for a long time and was favorable heavy rain. In the diameter velocity diagram, mesoscale convergence line, the adverse wind regions and the mid-cyclone were the important basis to determine producing and keeping heavy rainfall. Radar wind profile can reflect the configuration of layers of wind conditions, and it was an effective tool to determine whether the trough was in transition or not. [ Conclusion] The study provided reference for the short-term and nowcasting report.
