Saharan Dust concentrations are forecast to briefly decrease on Friday into the weekend with the passages of Tropical Waves 20 and 21. However, from late Sunday, the dust returns at mild to moderate levels across T&T, with higher concentrations north of the country.
What you need to know
— Saharan Dust Surges: Concentrations of Saharan Dust are forecast to decrease across the region through Friday afternoon, with little to no dust present through Saturday night when the next surge of dust arrives. This moderate concentration surge is forecast to linger through the next ten days, with additional surges moving across the region by July 13th and 15th. 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 and San Fernando are reporting moderate air quality levels. Stations at Arima, Beetham, and Signal Hill, Tobago, are not reporting PM2.5 or PM10 data as of Thursday 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, while at the Piarco International Airport, Trinidad, visibility fluctuated between 8 and 10 kilometers.
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 Friday afternoon.
As Tropical Waves 20 and 21 move across the region this weekend, another moderate concentration surge of dust is forecast to begin moving across the Lesser Antilles from mid-Sunday. 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 next week, with additional moderate surges moving across the region, mainly north of T&T, on Friday, July 14th, 2023, and late Saturday, July 15th, 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.
