Trinidad, Tobago, and most of the Southern Windwards will see mostly good air quality through the next ten days as tropical waves, and the Intertropical Convergence Zone are forecast to keep Saharan Dust north and east of the region.
For Trinidad and Tobago, over the next 24 hours, existing dust levels are forecast to decrease substantially.
What you need to know
— Saharan Dust Surges: The ongoing surge is forecast to diminish through the next 24 hours, with no additional major or significant surges forecast to affect T&T through the next ten days. By September 10th, forecast models indicate a moderate-concentration surge to arrive across the region.
— Impacts: Through the next 12-24 hours, air quality levels across Trinidad and Tobago will remain near moderate. By mid-Saturday, through the remainder of the forecast period, air quality is forecast to be mostly at good levels until September 10th.
— What Should You Do: Through Saturday morning, sensitive groups should take the necessary precautions. The general population will remain unaffected.
Current AQI Levels Across T&T
The Environmental Management Agency (EMA) air quality monitoring stations at San Fernando, Point Lisas, Signal Hill, and Port of Spain have recorded good to 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.
Over the last 24 hours, visibility remained near or above ten kilometers at the Piarco International Airport and A.N.R. Robinson International Airport at Crown Point, Tobago, outside of shower and thunderstorm activity.
Saharan Dust Forecast
Ongoing Surge: Ends Early Saturday, September 3rd, 2022
As Tropical Storm Earl moves northwestward, air quality is set to improve across Trinidad, Tobago, and the Lesser Antilles as higher dust concentrations move westward.
Concentrations are forecast to gradually diminish by early Saturday, with showers and thunderstorms providing localized air quality improvement.
Next Surge: Saturday, September 10th, 2022
Long-range forecast models indicate a moderate to a high-concentration surge of Saharan Dust arriving across the Lesser Antilles by late Friday, September 9th through Saturday, September 10th. A supplemental surge of dust is also forecast to arrive by September 12-13th.
What does this mean for you?
The air quality may remain degraded through Saturday, September 3rd, 2022, associated with Saharan Dust. 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.
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 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.