What is the relationship between tropical intraseasonal oscillations and El Nio/ La Nia?
Intraseasonal oscillations often exhibit a strong relationship to the phase of the ENSO cycle. Overall, there tends to be weak or absent MJO activity during moderate or strong El Nio episodes. In contrast, MJO activity is often substantial during ENSO-neutral years and during weak La Nia episodes. What are the impacts of intraseasonal oscillations on the U.S.? When do they occur? The strongest impacts of intraseasonal variability on the U.S. occur during the winter months over the western U.S. During the winter this region receives the bulk of its annual precipitation. Storms in this region can last for several days or more and are often accompanied by persistent atmospheric circulation features. Of particular concern are the extreme precipitation events which are linked to flooding. There is strong evidence for a linkage between weather and climate in this region from studies that have related the El Nio-Southern Oscillation (ENSO) to regional precipitation variability. From these stu
