A large tropical wave, Tropical Wave 17, has quelled Saharan Dust concentrations across Trinidad, Tobago, and the Eastern Caribbean over the last 48 hours. As this wave moves west, a mild surge of Saharan Dust forecast to move across the region, reducing air quality to moderate levels.
Across Trinidad and Tobago, air quality is at good levels with visibility above 10 kilometers.
After nearly two weeks of reduced air quality, levels have returned to good air quality across the entire Eastern Caribbean as of Wednesday evening.
This mild surge of dust will peak initially on Thursday, with a secondary peak on Saturday. This surge of dust will not be as severe as what we experienced throughout June, with mainly sensitive groups affected.
Note that in localized areas, further reduced air quality will occur in areas with smoke, fires, and high vehicular traffic.
The Environmental Management Agency (EMA) air quality monitoring stations are presently recording AQI values at levels that are good in Trinidad and Tobago 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.
The Saharan Dust Forecast
Based on the latest dust modeling, air quality across Trinidad and Tobago is forecast to reduce overnight tonight (Wednesday into Thursday) and fluctuate over the next two weeks as mild to moderate concentration of dust remain present.
Tropical waves over the next 2 weeks, in addition to the ITCZ, are forecast to improve air quality periodically. Note that higher concentrations are forecast to remain north of Trinidad and Tobago.
What does this mean for you?
For the general population, little to no impacts are forecast beyond reduced visibility. For sensitive groups, such as children, the elderly, and persons who suffer from respiratory ailments and allergies, you may need to avoid prolonged exertion outdoors. See the AQI levels versus the above Saharan Dust forecast for more details
We’re in a period where the ITCZ and tropical waves 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 frequent tropical waves also aid in improving air quality.
The concentration of the dust that follows the wave depends on the strength of the wave 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.
Larger, more concentrated plumes of Saharan dust begin to occur in April and continue through November.
Sensitive groups such as persons with respiratory ailments, children, the elderly and cardiopulmonary disease should take the necessary precautions on days where dust concentrations degrade air quality to moderate and beyond, as there is more Saharan Dust forecast.