Island Climate Update 230 - November 2019

ENSO-neutral conditions continued during October 2019, although the Southern Oscillation Index (SOI) and sea surface temperatures (SSTs) were on the El Niño side of neutral.

The NINO3.4 Index (in the central Pacific) for the month of October (to the 27th) was +0.54˚C, a substantial increase compared to September. Above average warmth continued in the NINO4 region (west-central Pacific) with a monthly anomaly of +0.95˚C. The NINO 1+2 Index was cooler than average, with a monthly anomaly of -0.48˚C.

Upper-oceanic heat content anomalies increased across the tropical Pacific during October, in response to weaker than normal trade winds throughout the month as well as a strongly positive Pacific Meridional Mode (well above average SSTs in the sub-tropical northeast Pacific).

While the ENSO status will most likely remain “neutral” over the next season, the atmosphere may respond in an El Niño Modoki-like (i.e. central Pacific) fashion at times.

According to the consensus from international models, oceanic ENSO-neutral conditions are most likely at 68% chance for the November – January period. For the February – April 2020 period, the probability for neutral conditions is 71%. For May – July 2020, the probability for neutral conditions and El Niño is 57% and 33%, respectively.

Download

Download the full report: Island Climate Update - November 2019