This study focuses on the relationship between the subtropical jets and the mid-latitude trough/ridge systems. The 1 to 2 week upper-tropospheric subtropical jets have been studied by removing 30 day running means for 200hPa zonal wind at every grid from November 1986 to April 1987. The period has already been known as a typical El Nino year. However, the resultant anomalies seemed to have a similar spectral structure to that of the height field Cross-correlation techniques were then performed to further study the relationship between those two variables. Results show good correlations between the jets and the height field. It is possible these results could be linked to the Rossby wave trains. Moreover, results of this study could also be useful to medium range forecasting