As we head into November, we’re approaching the time of year when Saharan Dust levels are typically at their lowest across the Atlantic Ocean. While dust levels are forecast to be fairly low to none at all over the next ten days, a short-lived surge is forecast from Thursday into this weekend, trailing Tropical Wave 48.
What you need to know
— Saharan Dust Surges: A brief surge of dust is forecast to move across T&T starting Thursday, but higher dust levels are forecast to remain north across the remainder of the Lesser Antilles. From Monday, October 28th, little to no dust is forecast through the first week of November.
— Impacts: Air quality is forecast to remain good to moderate throughout the forecast period.
— What Should You Do: Throughout the forecast period, sensitive groups are advised to take the necessary precautions, particularly during high traffic.
Current AQI Levels Across T&T
As of 1:00 PM Wednesday, October 23rd, 2024, the official air quality monitoring stations from the Environmental Management Agency (EMA) at San Fernando and Arima report good air quality, while Beetham and Point Lisas report moderate air quality. Signal Hill, Tobago, and Toco stations are not currently transmitting PM2.5 or PM10 data.
Unofficial air quality monitoring stations at Longdenville and Woodbrook report 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.
Outside of rainfall, visibility has remained 10 kilometers at the A.N.R. Robinson International Airport at Crown Point, Tobago, and the Piarco International Airport, Trinidad, over the last 24 hours.
Saharan Dust Forecast For T&T
Thursday (October 24th) until Monday (October 28th): Mild to moderate concentrations of Saharan Dust with air quality between good and moderate levels.
Monday (October 28th) through Saturday (November 2nd): Little to no Saharan Dust forecast across the country with generally good air quality.
What does this mean for you?
Mild to moderate concentrations of Saharan Dust periodically over the next seven to ten days are likely to bring air quality to moderate levels, chiefly affecting the most sensitive groups of the population. The general public is not required to take action.
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 are notable 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.
