Saharan Dust levels are forecast to increase from Wednesday following the passage of Tropical Storm Ernesto over the Leewards. Elevated concentrations are forecast through next week.
What you need to know
— Saharan Dust Surges: Through Wednesday morning, little to no Saharan Dust is forecast. From Wednesday, moderate to occasionally high dust levels are forecast through August 21st.
— Impacts: Air quality is forecast to remain good to moderate throughout the forecast period.
— What Should You Do: In times of unhealthy air quality, everyone should take the necessary precautions. Throughout the forecast period, sensitive groups are advised to take the necessary precautions, particularly during high traffic and in the vicinity of fires.
Current AQI Levels Across T&T
As of 8:00 PM Monday, August 12th, 2024, the official air quality monitoring stations from the Environmental Management Agency (EMA) at Arima, Point Lisas, and Toco all report good air quality, while Signal Hill and Beetham are not currently transmitting PM2.5 or PM10 data. Air quality at San Fernando is at moderate.
Unofficial air quality monitoring stations at Longdenville, St. Augustine, and Woodbrook are reporting good 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.
Over the last 24 hours, visibility has remained at 10 kilometers at the A.N.R. Robinson International Airport at Crown Point, Tobago and at the Piarco International Airport, Trinidad outside of rainfall activity.
Saharan Dust Forecast For T&T
Following Tropical Storm Ernesto, a high-pressure system rebuilds across T&T from Wednesday, leading to an increase in dust for the remainder of the forecast period.
Tuesday (August 13th) through early Wednesday (August 14th): Little to no Saharan Dust present, with air quality at good levels.
Late Wednesday (August 14th) through Wednesday (August 21st): Generally moderate to occasionally high concentrations of Saharan Dust across T&T and the Lesser Antilles, with higher dust levels north of T&T. Air quality levels generally at good to moderate levels.
What does this mean for you?
Elevated 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.
