Long-Range Forecast for Winter Polar Vortex

Using the Northern Hemisphere 500 hPa altitude data and North Pacific sea temperature data, the forecasting of winter polar vortex area index for I area, which would affect air temperature of China significantly, is conducted. The results show that the intensities of North Atlantic west wind circulation in prior March and North American big trough in May are good indication of the winter polar vortex intensity change. When the polar vortex is anomalous strong or weak the North Pacific sea temperature anomaly patterns are opposited. And, the sea temperature meridional balance in the mid-South Pacific and sea temperature zonal balance in the mid-west of North Pacific would influence the polar vortex area index significantly.