In August 1997 the tropics are almost uniformly warm, over both land and ocean. The warm anomaly over the eastern equatorial Pacific Ocean is known as the El Nino phenomenom. The anomaly is upwards of 4.25 degrees Celcius at the equator, making this one of the strongest El Ninos observed. Sea surface temperature anomalies in September are very similar globally to those in August. The El Nino remains essentially unchanged, but the warm anomaly in the north tropical Atlantic Ocean and the Bay of Bengal is increasing in September.
Most tropical land is anomalously warm.
October Sea surface temperature anomaly patterns remain similar. The magnitude of the El Nino signal is slightly reduced from September, and the peak continues to shift westward. A signifigant cold anomaly is beginning to form in the south tropical Atlantic Ocean and the warm anomaly in the Arabian Sea has strengthened considerably.