Trinidad and Tobago has had relatively dust-free days for much of this past week, and these conditions are forecast to continue into the weekend. However, by Tuesday, August 1st, 2023, mild concentrations of Saharan Dust are forecast to return across T&T and the Lesser Antilles.
What you need to know
— Saharan Dust Surges: Mild to moderate dust concentrations are forecast from August 1st through August 2nd, with a moderate concentration dust surge moving across the north of T&T from August 4th and across T&T from August 5th, with another moderate surge arriving by August 7th.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels. Islands north of Trinidad and Tobago could see further reductions in air quality and visibility.
— 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 Arima are reporting moderate air quality levels, while at San Fernando and Point Lisas, they are reporting good quality levels. Stations at Beetham, and Signal Hill, Tobago, are not reporting PM2.5 or PM10 data as of Friday 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.
Saharan Dust Forecast
Mild to Moderate Concentration Surges Forecast Over Next 10 Days
A brief mild to a moderate surge of Saharan Dust is forecast to move across the Lesser Antilles through the weekend, mainly north of Trinidad and Tobago, with generally good air quality in the wake of Tropical Wave 27.
The next surge of dust is forecast to move across T&T and the Lesser Antilles from early Tuesday, August 1st, 2023, as Tropical Wave 28 moves through the region, while the tropical disturbance trailing the wave moves northeast of the Leewards. Elevated concentrations of Saharan Dust are forecast to linger through August 3rd, with another surge of Saharan Dust moving across T&T from August 4th through August 6th.
While some brief improvement is forecast on August 7th, a surge of Saharan Dust is forecast yet again on August 8th, lingering into the mid-month.
Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels. Islands north of Trinidad and Tobago could see further reductions in air quality and visibility.
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.
