【摘要】 热带风暴"环高"(0311)具有结构浅薄,范围小,移动速度快等特点。对环流形势、云图、观测资料的分析发现,"环高"的云形,其形成、结构、移动和风雨影响都有东风波的特征。通过相关物理量诊断表明,从风暴南面和东南面有大量水汽的涌入体现了东风波的特征,高层没有水汽辐散不利于"环高"充分发展。8月19日08时垂直螺旋度正中心在500 h Pa左右,体现了东风波特征,到了20时,500 h Pa以下垂直螺旋度都是正值,以上是负值,此时的环境螺旋度分布比较有利于风暴的发展,但此时"环高"正接近陆地,导致"环高"发展不充分。更多还原

【Abstract】 Tropical storm Vamco(0311), with the features of shallow vertical structure, small horizontal scale and fast moving speed, was investigated with circulation background, satellite imagery and observational analysis. It is shown that the cloud shape, formation, structure, movement of Vamco and impact of Vamco reflect the features of the easterly wave. By using relevant physical variables, it is found that the large amount of water vapor pouring into the storm from south and southeast reflected the features of easterly waves and the moisture convergence appearing from low to middle levels was unfavorable to the full development of Vamco. The easterly wave’s positive center of vertical helicity at 8:00 August 19 th was at 500 h Pa. However, it should be favorable to Vamco’s development at 20:00 when the value of vertical helicity was positive in the middle and low level while being negative at and above 500 h Pa, but Vamco could not develop completely when it was close to the land.更多还原