Diagnostic Analysis of Rainstorm Causes and Perfect Helicity in the South of Henan on 23 June 2011
Abstract：Based on the conventional meteorological observational data and NCEP 1°×1° reanalysis data, the weather process of regional heavy rain occurred in the south of Henan from 22 to 23 June, 2011 were analyzed. The main conclusions are as follows. The backward-tilting trough in the middle and high levels, cold shear-line in the middle and low level and the west path of cold air in the surface are the mainly influence systems. One of the causes of rainstorm for cold shear-line is the cold pad caused by the north wind in the low level. The main source of water vapor is in the middle-low level. Changes in the horizontal helicity can reflect the movement and development of the mainly influence system ; and changes in the vertical helicity has a good reference value on the forecast of rainfall area and precipitation intensity ; heavy rain areas are in the energy environment of the largest helicity compatible with larger convective available potential energy（hvertical〉 10 × 10-8 hPa · s-2, CAPE 〈 1500 J · kg-1）.
Keywords：backward-tilting troughcold shear-linevertical helicityhorizontal helicityconvective available potential energy
Publication Date：2012-03-14
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：7( 49-55 )