Date: Thursday 11th of May 2023

A transition from ENSO-neutral to El NiƱo conditions is likely to occur within the next two months.

During April 2023, above-average sea surface temperatures (SST’s) expanded slightly westward into the central equatorial Pacific Ocean. The equatorial Pacific Ocean subsurface temperatures anomalies continue to increase, reflecting widespread positive temperature anomalies. Additionally, the warming of waters along South America's equatorial coastline continues unabated. However, the basin-wide coupled ocean-atmosphere system remains consistent with ENSO-neutral at this time. Climate models indicate that El Niño conditions are likely to form during the May-July season and persist into the December-January-February 2024.

What does this mean for Trinidad and Tobago?

Historically, ENSO-neutral conditions tend to produce near-normal rainfall within Trinidad and Tobago, but not always. There is a moderate probability (68%) that the ENSO-neutral conditions will likely have a positive influence on local rainfall during the months of May to August 2023. Partly cloudy to cloudy skies with warm/hot conditions will be followed by a gradual increase in the frequency of rainfall events from June to August. When El Niño conditions are fully entrenched over the area, there will be more sunny periods and moderate to light rainfall, with a lower probability of torrential rainfall events. This will continue until the end of the year.

Guide: A La Niña (El Niño) is declared when the average SSTs in the central and eastern equatorial Pacific Ocean become at least -0.5oC cooler than average (0.5oC warmer than average) in the preceding month and the cooling (warming) is expected to persist for five consecutive overlapping three-month periods. This must occur together with a corresponding change in the overlying atmospheric circulation. The TTMS’s La Niña/El Niño Watch is activated when the ENSO Outlook indicates a probability of approximately 50% chance or greater for the development of La Niña or El Niño.