Analysis of the Predictability of the May 10-14,2022 Short-range Intense Rain in Guangdong Province
Using observational data from automatic weather stations and radiosonde as well as the EC ERA 0.25 ×0.25 reanalysis,this paper ran a synoptic analysis of an intense rain that took place in the prov-ince of Guangdong on May 10 to 14,2022.On the basis of that,three physical quantities of 500 hPa relative vorticity,925 hPa divergence and 200 hPa divergence were abstracted to investigate their correlation with the short-range intense rain.Then,combinations of related physical quantities and the KNN classification algo-rithm(a kind of machine learning)were introduced to discuss the feasibility of predicting the area and in-tensity of the short-range intense rain.The results are shown as follows.With 500 hPa relative vorticity-5 × 10-5 s-1,925 hPa divergence≤5 ×10-5 s-1 and 200 hPa divergence in the range of(-10～20)× 10-5 s-1,the area where the short-range intense rain took place can be indicated to some degree,and when the combined condition is met for which 925 hPa divergence≤0 s-1,200 hPa divergence≥0 s-1 and 500 hPa relative vorticity≥0 s-1,the area receiving the short-range intense rain can be well indicated.The KNN algorithm,which is based on distance weight,did a good job in predicting the rainfall amount of the process of interest.
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