Following a major surge of Saharan Dust across T&T this past week, dust levels will be substantially less impactful over the next five to seven days. However, even with forecast rainfall, dust concentrations will remain mild to moderate.
What you need to know
— Saharan Dust Surges: The ongoing surge of dust is forecast to linger, with gradually decreasing concentrations through Friday, May 27th, 2022. Another mild to moderate dust surge is forecast by Monday, May 30th, 2022.
— Impacts: Air quality across Trinidad and Tobago will vary between moderate to unhealthy for sensitive groups through the forecast period, though rainfall will improve air quality levels in localized areas.
— What Should You Do: The air quality will continue to be degraded. Sensitive groups need to take necessary precautions, while the general population would be able to continue activities with minimal Saharan Dust safety measures.
Current AQI Levels Across T&T
The Environmental Management Agency (EMA) air quality monitoring stations at Port of Spain, San Fernando, and Signal Hill have all recorded moderate air quality levels over the last 24 hours.
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.
Visibility has fluctuated over the last day from 5 to 10 kilometers at the Piarco International Airport and 8 to 10 kilometers at the A.N.R. Robinson International Airport at Crown Point, Tobago.
Saharan Dust Forecast
Forecast models indicate that moderate to high Saharan Dust levels will persist across T&T through Friday, May 27th, 2022. During this period across Trinidad and Tobago, air quality will vary between moderate and unhealthy for sensitive groups, with the visibility dropping as low as 7 kilometers outside of shower or thunderstorm activity.
A notable improvement in air quality and dust concentrations is forecast from Saturday, May 28th, 2022, but this will be short-lived as another surge of dust moves in by Monday, May 30th, 2022. However, concentrations are forecast to be mild to moderate.
What does this mean for you?
Over the next ten days, air quality will be degraded, particularly through Friday, May 27th, 2022. During high traffic periods, particularly between 6:00 AM and 9:00 AM, and again from 3:00 PM through 6:30 PM, air quality may be further reduced in localized areas.
Sensitive groups, such as children, the elderly, and persons who suffer from respiratory ailments and allergies, should avoid prolonged or heavy exertion and should keep medication nearby.
We’re in a period where the Intertropical Convergence Zone and tropical waves 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 the strength of the wave 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 to occur in April and continue through November.
