Saharan Dust concentrations are forecast to increase following Tropical Waves 19 and 20 during the forecast period.
What you need to know
— Saharan Dust Surges: A moderate to high concentration surge of Saharan Dust is forecast to move across Trinidad and Tobago and the Lesser Antilles following the passage of Tropical Wave 19 by late Tuesday, July 4th, 2023, with some improvement forecast by Friday, July 7th, 2023. An additional surge is forecast to arrive by Sunday, July 9th, 2023, lingering through mid-month while higher dust levels remain north of the country.
— 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 are reporting moderate air quality levels while at San Fernando, air quality is just below moderate levels, remaining at good at this time. Stations at Arima, Beetham, and Signal Hill, Tobago, are not reporting PM2.5 or PM10 data as of Monday 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 continue to follow tropical waves
A mild to moderate surge of Saharan Dust arrived on Sunday, July 2nd, 2023, with some improvement expected today as Tropical Wave 19 moves across the region.
A subsequent surge of dust is forecast to move across the country by late Tuesday, July 4th, 2023, following Tropical Wave 19 and linger at least through Friday, July 7th, 2023, where dust levels improve ahead of Tropical Wave 20 this upcoming weekend.
However, another moderate to high concentration dust surge is forecast to follow Tropical Wave 20 over the weekend, with dust levels increasing by Sunday, July 9th, 2023. While concentrations will fluctuate, forecast models indicate higher levels of dust will remain north of T&T through the forecast period.
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.
