Saharan dust concentrations are forecast to increase on Sunday evening, with mild to, at times, moderate concentrations through the midweek. Across the country, air quality is at good levels with visibility above 10 kilometers as of 3:00 PM Sunday 23rd August 2020.
Two mild surges of Saharan dust is forecast across the Lesser Antilles over the next 10 days with higher concentrations remaining north of T&T.
The Environmental Management Agency (EMA) air quality monitoring stations are all presently not publicly reporting data, though other air quality monitoring stations are 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 remain at mostly good levels through the forecast period, at times moderate.
One surge of Saharan Dust begins on Sunday afternoon, initially across Tobago and then across Trinidad by nightfall. Mild concentrations will subside by midweek. The other surge of Saharan Dust forecast to arrive by August 27th, following the passage of Tropical Wave 40. During peak surges, air quality may dip to moderate leaves with slightly reduced visibility.
Across Trinidad and Tobago, showers and isolated thunderstorms are forecast to temper air quality impacts, with higher concentrations still remaining north of T&T.
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.