Over many decades, the regular transition from El Nino to La Nina events with a neutral intermediate period has occurred over three-to-seven-year cycles. More recently, for conditions that are not fully understood, transitions are occurring over shorter periods and the intensity of drought associated with La Nina and floods and hurricanes concurrent with an El Nino are becoming more intense.
The International Research Center for the El Nino Phenomenon noted, “A year ago we came out of a La Nina and in March there were signs of a transition to El Nino. Rapid changes in the cycle will undoubtedly impact crop production with corresponding economic effects”.
It is noted that the intense La Nina over the past three years was responsible for drought-reated low yields for crops in Chile and Peru. Reduced water flow through the Panama Canal, has restricted passage of vessels and has raised the cost of ocean transport. The ongoing El Nino was expected to restore water levels in the Canal but with an unexpected and abrupt return to a La Nina the unfavorable situation may persist.