While mild to occasionally moderate dust levels are forecast to take Trinidad, Tobago, and the remainder of the Lesser Antilles through the upcoming weekend, tropical wave activity is forecast to combat any major decrease in air quality. However, by Monday through next week, a prolonged dust surge is forecast to move across the Caribbean.
What you need to know
— Saharan Dust Surges: Mild to moderate dust concentrations are forecast from August 10th and fluctuate into the weekend with some improvement forecast. However, from Monday, August 14th, 2023, through next week, moderate to high concentrations of Saharan Dust are forecast to persist across T&T through the end of the forecast period.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels. From August 14th, 2023, air quality may dip to levels that are unhealthy for sensitive groups.
— 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 good quality levels. Stations at Beetham, Arima, and Signal Hill, Tobago, are not reporting PM2.5 or PM10 data as of 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 at the Piarco International Airport, Trinidad.
Saharan Dust Forecast
Mild dust into the weekend, then a high concentration surge next week
Following the passage of Tropical Wave 32 on Wednesday through Thursday, a mild to moderate surge of Saharan Dust is forecast to move across T&T with higher concentrations remaining north of the country into the weekend, gradually decreasing with Tropical Wave 33 moving across the region on Sunday.
Following the passage of Tropical Wave 33, however, a large dust plume is forecast to move in with moderate to high concentrations of Saharan Dust that is forecast to linger across the Eastern Caribbean, including T&T through the forecast period (August 19th).
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. From August 14th, 2023, air quality may dip to levels that are unhealthy for sensitive groups.
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.
