The findings show that location of hail embryo lies in front of the main updraft, at the turning of updraft to divergence downdraft, and above the largest ascending velocity in the vertical direction.

• 结果表明：雹胚源区出现在主上升气流前侧上升气流向辐散下沉气流的转向处，在垂直方向上位于最大上升速度上方；