Met Service: Rainy season starts after heavy showers

The Meteorological Service (TTMS) has officially declared the start of the 2024 wet season on May 25.

This follows the recording of rainfall accumulations on both islands over several hours on May 25.

In a release, the Met Service said the start of the wet season is marked by measurable rainfall (greater than or equal to 0.1 mm) produced by a tropical wave and/or the InterTropical Convergence Zone (ITCZ).

It said as of 2 pm on May 25, the Met Service automatic weather stations at Mayaro and Paramin recorded 7.4 mm and 19.8 mm of rainfall respectively, with higher accumulations observed in other areas.

It said a very active tropical wave which moved off the west coast of Africa and crossed the tropical Atlantic Sea affected Trinidad and Tobago with scattered, light to moderate showers and isolated thunderstorms, mainly over Trinidad, on May 25.

The Met Service said as the weekend progresses, the tropical wave will continue to move across Trinidad and Tobago producing occasional moderate showers and a medium chance (60 per cent) of isolated heavier showers or thunderstorms with accompanying gusty winds. Seas are expected to become choppy in the event of gusty winds.

A moderate concentration of Sahara dust is forecast to follow the wave from the evening on May 26.

The ITCZ, which is currently near latitude 4.0 N, will continue to slowly migrate northwards and is expected to bring increased rainfall and potentially more frequent weather disturbances as the wet season advances.

The Met Service said The El Niño Southern Oscillation (ENSO) is currently in a weak El Niño phase, but a transition to a La Niña phase is expected by the middle of the wet season, which will influence the weather patterns throughout the season.

It said for the first half of the wet season (June-August), rainfall is expected to range from near-normal to above-normal amounts. Wetter-than-normal conditions are particularly anticipated in western Trinidad and over most of Tobago. During the latter half of the wet season (September-November), rainfall is likely to be near-normal.

Overall, the 2024 wet season is expected to be mostly near-normal in terms of rainfall, with some regions experiencing above-average precipitation early in the season. The potential for floods is moderately increased for established flood-prone areas and slightly higher for locations that are becoming flood-prone.

The Met Service said the Atlantic Hurricane Season, which runs from June 1-November 30, coincides with Trinidad and Tobago’s wet season.

“For 2024, our region faces another potentially active hurricane season with heightened tropical cyclone activity expected during the peak months of August-October, with the greatest likelihood of tropical cyclones in August and September.”

It noted that Trinidad and Tobago usually experienced peak Sahara dust concentrations in June. These dense dust plumes can suppress deep convection and limit significant rainfall while causing hazy conditions and poor air quality. Residents with respiratory conditions should take precautions during high dust periods. Nevertheless, under the presence of Sahara dust, impactful rainfall can still occur given the right atmospheric conditions.

“The Met Service wishes to assure the national community that we continue to closely monitor weather conditions over land sea and air within our area of responsibility and will continue to advise the general public in a timely manner, about impending adverse weather-related hazards. The public, relevant agencies and ministries are advised to adopt measures to mitigate the potential impacts of the wet season.”

For further information, follow updates from the Met Service and other relevant authorities. Access daily forecasts at 6 am, 10 am and 4 pm, as well as monthly seasonal outlooks on the TTMS website at www.metoffice.gov.tt, social media platforms and the TT Met weather app.