Saharan Dust concentrations are at their peak on Thursday, June 29th, 2023 with some improvement expected associated with Tropical Wave 18 and 19 through the forecast period.
What you need to know
— Saharan Dust Surges: A moderate to high concentration surge of Saharan Dust is present across Trinidad and Tobago and the Lesser Antilles following the passage of Tropical Wave 17 on Wednesday, with additional surges arriving by Sunday, July 2nd, 2023, and early Wednesday, July 5th, 2023, with longer range models indicate a significant surge of arriving by Sunday, July 9th, 2023.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels, dipping to levels that are unhealthy for sensitive groups on Thursday, June 29th, 2023, through the first half of Friday, June 30th, 2023.
— 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 moderate air quality levels at this time, while stations at Arima, Beetham, and Signal Hill, Tobago, are not reporting PM2.5 or PM10 data as of Thursday 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, while at the Piarco International Airport, Trinidad, visibility ranged between seven and ten kilometers.
Saharan Dust Forecast
Surges continue to follow tropical waves
A moderate to high concentration surge of Saharan Dust is moving across Trinidad and Tobago and the Lesser Antilles following the passage of Tropical Wave 17 late Wednesday. Peak concentrations are forecast on Thursday, June 29th, 2023, into early Friday, June 30th, 2023. Concentrations are forecast to remain at elevated levels, with some decrease on Friday into Saturday as the Intertropical Convergence Zone drifts across T&T and the passage of Tropical Wave 18 by late Saturday.
Another surge is forecast to arrive by Sunday, July 2nd, 2023, with mild to moderate concentrations.
Air quality improvement is forecast on Monday into Tuesday as another tropical wave is forecast to move across the country by late Monday through Tuesday, with a subsequent surge of dust arriving by mid-Wednesday, July 5th, 2023.
Longer range models indicate Saharan Dust levels will decrease substantially by Friday, July 7th, 2023, with a significant surge of dust arriving by Sunday, July 9th, 2023.
Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to remain between good and moderate levels, dipping to levels that are unhealthy for sensitive groups on Thursday, June 29th, 2023, through the first half of Friday, June 30th, 2023, 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.
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.
