No major surges of Saharan Dust are forecast to affect Trinidad and Tobago over the next ten days, with mild to moderate concentrations affecting the entire Lesser Antilles chain by the end of this week. Forecast rainfall from tomorrow (Wednesday) through Friday is expected to maintain mostly good air quality nationwide.
What you need to know
— Saharan Dust Surges: While there are no significant dust surges forecast to move across the region over the next ten days, two mild dust surges are forecast to move across T&T during the afternoon on Wednesday, November 15th, 2023, and again from late Friday, November 17th, 2023.
— Impacts: Over the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain good and moderate.
— What Should You Do: Sensitive groups are advised to take the necessary precautions, particularly during high traffic.
Current AQI Levels Across T&T
The official air quality monitoring stations from the Environmental Management Agency (EMA) at San Fernando, Arima, and Point Lisas report good air quality levels. Stations at Beetham and Signal Hill, Tobago, are not reporting PM2.5 or PM10 data as of Tuesday afternoon.
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
A surge of Saharan Dust is forecast to move across the Lesser Antilles from tomorrow (Wednesday, November 15th, 2023) afternoon, with higher dust concentrations across the northern Windwards and Leewards as rainfall will temper dust impacts across much of the central and southern Windwards.
Some brief improvement is forecast overnight Thursday, November 16th, 2023, into the early morning of Friday, November 17th, 2023, as a trough affects the region. Following this trough, a more prolonged but mild to moderate surge of Saharan Dust is forecast to move across the region from Friday afternoon (November 17th) and remain across the Lesser Antilles, including T&T, through Thursday, November 23rd, 2023.
Air quality levels across Trinidad and Tobago are forecast to remain between good and moderate over the next seven to ten days. Air quality may be further reduced near bush or landfill fires or during high-traffic periods.
What does this mean for you?
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.
