Rainfall Patterns and ENSO

Strong El Nino

During strong EL Ninos such as in 1982-83 and 1997-98, storminess is greatly increased over Florida and the Gulf of Mexico leading to well above average rainfall and perhaps widespread flooding. The map below shows rainfall greatly exceeding normal (in red) over Florida and California for the month of February 1998 during a strong El Nino.

The graph below shows accumulated dry season rainfall (green) versus normal for the Florida grid from 1 November 1997 to 30 April 1998 during strong EL Nino conditions. The dry season began with above normal rainfall, and the rainfall surplus continued to build until late in the dry season when a transition to La Nina conditions began.