Island Climate Update 234 - March 2020

El Niño Southern Oscillation (ENSO) neutral conditions continued during February 2020. The Southern Oscillation Index (SOI) was 0.2.

The NINO3.4 Index anomaly (in the central Pacific) for February was +0.30˚C, slightly cooler than January. The warmest ocean waters with respect to average continued to be located in the west central Pacific. Upper oceanic heat content remained above average near the Dateline, as it has for much of the past year. While the current ENSO status remains neutral, the system leans slightly in the direction of El Niño.

Rainfall and convection was well above normal in the vicinity of the Dateline and across the Southwest Pacific, caused by four tropical cyclones ( Uesi , Vicky, Wasi , Esther). Over the next several months, a warm pool of water in the west central Pacific is expected to regularly be a focal point for rain, thunderstorms, and tropical cyclone development; this may encompass the Coral Sea at times as well.

Trade winds were weaker than normal near and west of the Dateline during February, allowing the west central Pacific warm pool of ocean water to persist. During March, weaker than normal trade winds are expected to persist in the west central Pacific while enhanced trade winds are possible in the east central part of the basin. This should lead to persistence of the current SST pattern (warmer west, cooler east).

According to the consensus from international models, ENSO neutral conditions are most likely (70% chance) for the March May period. For the June August period, the probability for ENSO neutral conditions is 57%. The probability of El Niño increases to 37% in September November although ENSO neutral remains the most likely outcome (39% chance).

Download the full report: Island Climate Update - March 2020

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Meteorologist/Forecaster
Research subject: Climate