High concentrations of Saharan Dust are still affecting T&T, but with the forecast movement of tropical waves and the Intertropical Convergence Zone (ITCZ) across the country, dust levels are set to decrease across T&T, but remain high across the remainder of the region.
What you need to know
— Saharan Dust Surges: A high to significant concentration Saharan Dust surge is forecast to move across the area tonight (Tuesday) through Thursday morning. Thereafter, moderate to high dust levels are forecast to remain across T&T through Tuesday, July 2nd, where T&T will see a brief 24-hour window of good air quality, before moderate to high dust levels return from Thursday, July 4th.
— Impacts: Air quality is forecast to generally remain moderate, occasionally reaching levels that are unhealthy for sensitive groups through the next 48 hours, and in the vicinity of smoke, fires, or high traffic.
— What Should You Do: In times of unhealthy air quality, everyone should take the necessary precautions. Throughout the forecast period, sensitive groups are advised to take the necessary precautions, particularly during high traffic and in the vicinity of fires.
Current AQI Levels Across T&T
The official air quality monitoring station from the Environmental Management Agency (EMA) at Signal Hill reports moderate levels, while Arima, Point Lisas, Toco, and San Fernando all report good air quality. As of 2:00 PM Tuesday, June 25th, 2024, there is no data from Mayaro and Beetham, Port of Spain.
Unofficial air quality monitoring stations at Longdenville, St. Augustine, and Woodbrook are reporting good air quality.
These measurements are based on PM2.5 (particulates the size of 2.5 micrometers and smaller, usually associated with increases in Saharan Dust, vehicle exhaust, and smoke) and PM10 particulates.
Over the last 24 hours, visibility has remained at 10 kilometers at the A.N.R. Robinson International Airport at Crown Point, Tobago, and at the Piarco International Airport, Trinidad, outside of rainfall activity.
Saharan Dust Forecast
Tuesday night (June 25th) through Thursday afternoon (June 27th): High to significant levels of Saharan Dust trailing Tropical Wave 14. Air quality at moderate to unhealthy for sensitive groups.
Thursday afternoon (June 27th) through Tuesday night (July 2nd): Moderate to high concentrations of Saharan Dust across both islands, with generally moderate air quality. A well-defined tropical wave (Tropical Wave 15) set to approach the region on July 2nd.
Wednesday (July 3rd): Little to no Saharan Dust as a result of the passage of Tropical Wave 15. Air quality good.
Thursday (July 4th) through Saturday (July 6th): Moderate to high concentrations of Saharan Dust across both islands, with generally moderate air quality.
What does this mean for you?
With elevated concentrations present and drier and breezier conditions bringing the risk of fires, air quality is still forecast to be reduced, with further reductions in localized areas of fires, blowing smoke and dust, and high traffic.
We’re in a period where the Intertropical Convergence Zone, tropical waves, and occasional tropical cyclones may shield Trinidad and Tobago from the Saharan Dust events. While tropical waves are notable in moving dust across the Atlantic and the Eastern Caribbean, these periodic tropical waves also improve air quality.
The concentration of the dust that follows the wave depends on its strength as it moves off the West African Coast. This is because of stronger thunderstorms across Central Africa. As strong winds move downward and outward from these thunderstorms, the wind kicks up dust as it moves across parts of the Saharan Desert and transports it into the upper atmosphere. This “plume” of dust follows the axis of the wave as it progresses westward into the Atlantic.
Dust that makes it into the upper levels of the atmosphere can then get transported across the Atlantic Ocean. The plumes of dust eventually affect the Eastern Caribbean.
Larger, more concentrated plumes of Saharan dust begin in April and continue through November.
