A high concentration surge of Saharan Dust moved across Trinidad and Tobago on Sunday, with peak concentrations now moving through the Caribbean Sea. However, elevated dust levels are forecast to remain across the country through the forecast period, with brief improvements during the passages of tropical waves.
What you need to know
— Saharan Dust Surges: Concentrations of Saharan Dust are forecast to decrease across the region into Tuesday as Tropical Wave 22 moves across the Lesser Antilles by midweek. Another moderate to high concentration surge of dust is forecast by late Wednesday, July 12th, 2023, with subsequent surges on July 15th and 19th. Generally, higher dust levels are forecast north of T&T.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels.
— What Should You Do: Sensitive groups may need to take the necessary precautions, particularly during high-traffic periods and in the vicinity of bushfires.
Current AQI Levels Across T&T
The official air quality monitoring stations from the Environmental Management Agency (EMA) at Point Lisas, Arima, and San Fernando are reporting moderate air quality levels. Stations at Beetham, and Signal Hill, Tobago, are not reporting PM2.5 or PM10 data as of Monday afternoon.
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 remained unaffected by Saharan Dust and smoke at the A.N.R. Robinson International Airport at Crown Point, Tobago, and at the Piarco International Airport, Trinidad. Passing showers and thunderstorms, however, have briefly dropped visibility.
Saharan Dust Forecast
Surges continue to follow tropical waves
A moderate to high concentration surge of Saharan Dust continues to move across the region, with the higher concentrations now moving into the Caribbean Sea and overall concentrations decreasing across the Lesser Antilles through Tuesday.
As Tropical Wave 22 moves across the region on Tuesday into Wednesday, another moderate concentration surge of dust is forecast to begin moving across the Lesser Antilles from mid to late Wednesday, July 12th, 2023. For Trinidad and Tobago, the Intertropical Convergence Zone is forecast to be nearby, shielding the country from the highest dust levels that will move across the Leewards and northern Windwards.
Across T&T, mild to moderate dust levels are still forecast across the country through this week into the weekend, with additional moderate surges moving across the region, mainly north of T&T, on Saturday, July 15th, 2023 and Wednesday, July 19th, 2023.
Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels.
What does this mean for you?
The air quality is forecast to be lowered primarily during high traffic periods, particularly between 6:00 AM and 9:00 AM and again from 3:00 PM through 6:30 PM.
We’re in a period where the Intertropical Convergence Zone and tropical waves and occasional tropical cyclones may shield Trinidad and Tobago from the Saharan Dust events. While Tropical Waves play a notable role 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.
