After dust-free days due to periods of heavy rainfall, Saharan Dust levels are set to increase across Trinidad and Tobago and remain elevated through the next seven to ten days. Note that even with anticipated rainfall today (Wednesday, June 14th, 2023), Saharan Dust concentrations will begin increasing. However, showers and thunderstorms will bring brief air quality improvements.
What you need to know
— Saharan Dust Surges: A mild concentration surge of Saharan Dust is forecast to begin affecting Trinidad and Tobago from Wednesday, June 14th, 2023, becoming moderate by nightfall into Thursday. Mild to moderate concentrations of dust are forecast to linger through the subsequent week. Some improvement is forecast between June 20th and 22nd, with an additional dust surge arriving by late June 23rd, following an amplified Tropical Wave.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels, with occasional improvement during the passages of tropical waves.
— What Should You Do: Sensitive groups may need to take the necessary precautions, particularly during high-traffic periods and in the vicinity of bushfires.
Current AQI Levels Across T&T
The official air quality monitoring stations from the Environmental Management Agency (EMA) at San Fernando and Point Lisas are reporting good air quality levels at this time, while stations at Arima, Beetham, Port of Spain, and Signal Hill, Tobago, are not reporting data at this time. However, unofficial ambient air quality monitoring stations are reporting good air quality levels, in line with current dust modelling.
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 the Piarco International Airport, Trinidad.
Saharan Dust Forecast
Next Surges of Saharan Dust
By Wednesday, June 14th, 2023, a mild to moderate surge of Saharan Dust is forecast to move across the Lesser Antilles, with higher concentrations affecting the region from overnight Wednesday, continuing between June 15th and 19th.
Some improvement is forecast between late Monday, June 19th, 2023, through Wednesday, June 21st, 2023, with a surge of dust arriving afterwards following the passage of what is forecast to be a relatively amplified tropical wave. Longer range models indicate this is also forecast to be a mild to moderate concentration surge with higher dust levels remaining north of Trinidad and Tobago.
Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels, with occasional improvement during the passages of tropical waves.
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, as well as during times of blowing smoke and dust from bushfires.
We’re in a period where the Intertropical Convergence Zone and 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.
