Analysis on the Forecast Characteristics of K Index and Low-altitude Jet Stream in the Rainstorm Process

By using the durative rainstorm data in the South China during May-early June in 2010,the forecast characteristics of K index and low-altitude jet stream were analyzed.The results found that K2 had the good indication,advancement and relativity on the intensity and falling zone forecast of regional rainstorm in 24 h in the future,and the positive relative coefficient reached 0.987.The low-altitude jet stream also had the good advancement and indication significance on the intensity and influence scope of regional rainstorm in 24 h in the future,and the relative coefficient reached above 0.8.K2 and the low-altitude jet stream were selected as the main factors,and the basic conceptual model of rainstorm falling zone was established.The conceptual model had passed the computer program and realized the business automation.K2 provided the important basis for the forecast of rainstorm intensity and falling zone.