VARIABILITY OF PRECIPITATION IN BAJA-CALIFORNIA-SUR (MEXICO) IN 1990 - POSSIBLE CAUSES

During 1990, rainfall over Baja California Sur, Mexico, reached very high values, accounting for the third highest record since 1950. The characterization of the seasonal precipitation pattern on that year was intended, by the analysis of some rainfall temporal indicators: relative contribution of the summer and winter precipitation, interannual variation among both coasts and tropical hurricanes occurring over the area; as well as some spatial ones; like the modification of the average previously defined precipitation spatial distribution (regions) over the state. Results are compared with those registered during 1983, a year with high precipitations derived from by a particularly intense ENSO event. The comparative analysis of the selected indicators shows that the conditions originating high rainfall values during 1990 were quite different than the conditions on 1983. The spatial behavior of the precipitation regimes during 1990 is associated with a persisting and high SST warm anomaly occurred over the west coast of Baja California during 1990 and the first part of 1991.