Following the passage of Invest 91L on Wednesday, a marginal increase in Saharan Dust is forecast across Trinidad and Tobago on Thursday, while higher dust concentrations are forecast to affect islands north of T&T from today (Tuesday). Showers and thunderstorms associated with Tropical Wave 41/Invest 91L and the Intertropical Convergence Zone will also improve dust concentrations across the country.
What you need to know
— Saharan Dust Surges: Across Trinidad and Tobago, Saharan Dust levels are forecast to remain mild to minimal, with surges generally passing north of the country. The next surge is forecast to arrive by Thursday, October 6th, 2022, across Trinidad and Tobago, with peak concentrations occuring during the first half of Thursday, October 6th, 2022. Another moderate surge is forecast to arrive by October 10th with increasing concentrations through Thursday, October 13th, 2022.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago will fluctuate between good and 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
The Environmental Management Agency (EMA) air quality monitoring stations at Port of Spain and San Fernando have recorded good to moderate air quality levels over the last 24 hours, while at Point Lisas, air quality remains at good levels. The station at Signal Hill has not reported data in the last 24 hours.
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 near or above ten kilometers at the Piarco International Airport and A.N.R. Robinson International Airport at Crown Point, Tobago, outside of shower and thunderstorm activity.
Saharan Dust Forecast
Next Surge: Thursday, October 6th, 2022
Dust models show no major surges of Sharan Dust for T&T over the next seven to ten days, with higher dust concentrations remaining north of the country. However, a moderate surge of dust, with higher dust levels north of Trinidad and Tobago, is forecast to move across T&T by early Thursday with fluctuating concentrations through this week, generally at moderate to mild levels.
Air quality levels will vary from good to moderate across T&T, with visibility generally unaffected by Saharan Dust. Visibility is forecast to be affected by showers and thunderstorms, which will also aid in air quality improvement.
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.
