Prediction models of summer extreme high temperature in Liaoning province

Based on the summer extreme high temperature data in 23 weather stations in Liaoning province and 74 circulation indices information from the climate monitoring department of the National Climate Center (NCC), China Meteorological Administration (CMA), the temporal and spatial distribution features of summer extreme high temperature in Liaoning province were analyzed by a Empirical Orthogonal Function (EOF) decomposition method. The results show that the first EOF vector is characterized by a uniform anomaly over the whole area and the centers are in the northern and northwestern Liaoning province, while the second and third EOF vectors are the reversed phase patterns in the east and west areas and in the south and north areas, respectively. The correlation coefficient between first three time coefficient series and preceding circulation indices are calculated. It is found that the influencing factors are different for the three time coefficients. The optimum subset regressions are chosen as prediction equations using the CSC evaluation method and the fitting rate of past records in the 23 weather stations and each year are tested. It shows that the fitting rate of past records in the 23 weather stations is generally stable, except for in the western Liaoning province. In addition, the fitting rate is unbalanced each year, and it is stable in most years, while it is low in few individual years. While the prediction effect is good for the first year in the future it declines yearly in the following two years. The results can be used as reference in climatic prediction.