Prediction of the interannual variations of tropical cyclone movement over regions of the western North Pacific

Correlations are made between the annual number of occurrences of TCs in these prescribed regions and the principal components of the monthly mean 850- and 500-hPa zonal wind patterns over the western North Pacific (for the months of November of the previous year to April of the current year). Westward-moving cyclones are found to correlate well with the 850-hPa zonal wind patterns in January and March. Using the principal components associated with these patterns, prediction equations are then developed using the total (dependent) sample and the jackknife method (simulating an independent sample). The predictions made with both the dependent and "independent' samples are found to be very good. For north-westward moving cyclones, no prediction equation is developed because principal components of the 850- and 500-hPa zonal winds found to be significant can explain less than 30% only of the total variance. -from Author