After a fairly dust-free weekend ahead, mild concentrations of Saharan Dust are forecast across Trinidad, Tobago, and the Lesser Antilles from Monday, with higher concentrations generally remaining north and east of Trinidad and Tobago.
What you need to know
— Saharan Dust Surges: A mild surge of Saharan Dust is forecast by late Monday, October 31st, 2022, but the ITCZ is forecast to temper any reduction in air quality. Peak concentrations are forecast to arrive by Wednesday night into early Thursday, with improvement thereafter.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to be mainly at good levels, at times dropping to moderate levels.
— What Should You Do: Sensitive groups may need to take the necessary precautions, particularly during high-traffic periods. The general population will remain unaffected.
Current AQI Levels Across T&T
Though most official air quality monitoring stations from the Environmental Management Agency (EMA) are not reporting data at this time, unofficial stations across the country generally show good air quality, with the sole official site at Beetham, Port of Spain, reporting data showing good to moderate air quality.
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 at the Piarco International Airport and the A.N.R. Robinson International Airport at Crown Point, Tobago.
Saharan Dust Forecast
Next Surge: Late Monday, October 31st, 2022
A mild to moderate-concentration surge of dust is forecast across Trinidad, Tobago, and the remainder of the Lesser Antilles from Monday, October 31st, 2022, with higher concentrations north of T&T.
For Trinidad and Tobago, concentrations are forecast to diminish by late Thursday, November 3rd, 2022.
Longer range modeling shows another surge arriving across the Lesser Antilles by November 5th-6th. However, the ITCZ and southerly surge of winds are forecast to remain near or across T&T through the first week of November, limiting air quality impacts.
Air quality levels will fluctuate between good and moderate. Horizontal visibility may dip as low as 9 kilometers outside of shower and thunderstorm activity.
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, 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.
