Effects of complex underlying surfaces on a severe convection weather event in dry conditions in central part of Shandong Province
ZHENG Lina
YU Shuting
JIAO Yang
CHU Yingjia
SUN Changzheng
Abstract：Using the data of intensive automatic meteorological observing stations,lightning location system,Doppler weather radar and wind profile radar,as well as ERA5 data,the severe convection weather event in dry conditions that occurred in the central part of Shandong Province on 7 June 2023 is analyzed with a focus on the role of complex underlying surfaces.The results are shown below.(1)Due to the consideration of the relative humidity in the lower troposphere which is less than 40％,the larger convective inhibition and the weaker low-level system,the forecasters do not place enough attention on the environmental conditions,which are similar to the typical dry downburst in this area,and the role of complex underlying surfaces(the Yellow River surface,the big city and Mount Tai).Therefore,there is misjudgment in the prediction of the convection weather.(2)The convection cells first appear in the area of higher dew point temperature near the Yellow River west of Jinan City,and then move eastward into the city,where they are triggered by the dew point front and the ground mesoscale convergence line.The energy accumulated by the urban heat island effect is released,causing the convection cells to develop,intensify and eventually form a northwest-southeast echo band.(3)A gust front appears ahead of the echo band(i.e.,on the east side),and the convection cells triggered by the interaction of the gust front and the ground convergence line are continuously merged into the echo band,maintaining and strengthening the intensity of the echo band.After reaching the foot of Mount Tai,the echo band climbs up under topographic uplift effect,and the elevation enhances the echo intensity.As the ground convergence line disappears,the echo band weakens after crossing the mountain range,and the severe convection weather ends.(4)There are two local flow fields near Mount Tai,namely a zonal flow field on the west side of the mountain that rises near the mountain but sinks farther west,and a meridional flow field on the north side of the mountain that rises farther north but sinks near the mountain.The existence of these two flow fields,together with the triggering of the ground mesoscale system,makes the convection cells first develop and strengthen on the northwest side of the mountain.The south side of the mountain is not conducive to the development of convective clouds,resulting in the weakening of echoes after reaching the south side of the mountain.
Keywords：underlying surfacesevere convectionMount Taithe Yellow River surface
Publication Date：2025-08-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：10( 10-19 )