Saharan Dust concentrations are forecast to briefly decrease through the next 72 hours following the passage of Tropical Wave 14 and Tropical Storm Bret, but more dust remains on the horizon.
What you need to know
— Saharan Dust Surges: A mild to moderate concentration surge of Saharan Dust is forecast to move across Trinidad and Tobago and the Lesser Antilles following the passage of Tropical Storm Bret by Friday, with an additional surge arriving by Monday, June 26th, 2023, and linger through the end of the month.
— 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 San Fernando, Arima, and Point Lisas are reporting moderate air quality levels at this time, while stations at Beetham and Port of Spain, and Signal Hill, Tobago, are not reporting PM2.5 or PM10 data as of early Wednesday morning.
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 the Piarco International Airport, Trinidad.
Saharan Dust Forecast
Surges to follow tropical systems
The next surge of Saharan Dust is forecast to arrive across T&T and the Eastern Caribbean region by Friday, June 23rd, 2023, with mild to moderate concentrations. Marginal improvement is forecast through the weekend, with another mild to moderate surge arriving across the region from Monday, June 26th, 2023, and linger through the remainder of the forecast period into June 30th, 2023.
Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels, with occasional improvement during the passages of tropical waves.
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.
