Three‐dimensional view of snow streamers producing heavy snowfall over southern England obtained from a T + 6h mesoscale model forecast valid at 1200 utc, 1 February 2019, showing a sub‐set of the computational domain 4km high and approximately 240 × 240km as viewed from the west. The 3D isosurface depicts a model reflectivity of 23dBZ, corresponding to a moderate snowfall intensity and has been shaded according to vertical air velocity according to the colour scale. Note the cellular and sloping nature of the streamers within the snow bands and the strong positive vertical velocities consistent with the presence of shallow ‘generating’ cells of upright convection at their top.

中文翻译：

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一场预测不到的暴风雪，伴有小而深的对流层顶凹陷

根据2019年2月1日在1200 utc有效的T + 6h中尺度模型预测获得的在英格兰南部产生大雪的飘雪的三维视图，显示了计算域的子集，高度为4 km，大约为240×240 km西方。3D等值面描绘了23dBZ的模型反射率，对应于中等的降雪强度，并已根据色标根据垂直空气速度进行了阴影处理。请注意，雪带内的拖缆具有蜂窝状和倾斜性，并且强烈的正垂直速度与顶部垂直对流的浅“生成”细胞的存在相一致。