This figure shows a snapshot on 8 July 1997 of model sea surface height anomaly from a 1/4-degree thermodynamic finite-depth model planned for transition to a Navy nowcast/forecast system.
Anomalously high sea level is depicted by the red/orange colors, and low sea level by the blues. The model successfully depicts the current El Nino. A classic signature of El Nino is anomalously high sea level in the eastern tropical Pacific, as depicted by the figure. The anomalously high sea level in the eastern Pacific is the result of an equatorial Kelvin wave that traveled across the basin approximately 2 months before. The Kelvin wave was driven by a relaxation of trade winds.