Moderate concentrations of Saharan Dust are forecast to move across Trinidad and Tobago on Wednesday 3rd March 2021, with concentrations gradually decreasing into the weekend. Forecast rainfall may temper decreased air quality, particularly on Thursday.
The Environmental Management Agency (EMA) air quality monitoring stations are recording AQI values at levels that are good in Trinidad and Tobago as of Tuesday 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.
The Saharan Dust Forecast
From Tuesday night into Wednesday morning, very mild concentrations of Saharan Dust will be present. The air quality will generally be at good levels in areas.
After midday on Wednesday through Thursday morning, peak concentrations will occur with skies becoming hazy and air quality diminishing. Air quality levels are forecast to decrease to moderate during this period.
Dust concentrations will gradually diminish into the weekend, with another moderate surge of dust forecast on Wednesday 10th March 2021. The air quality will fluctuate between levels that are good to moderate during this period, improving during and after rainfall.
What does this mean for you?
For the general population, mainly Wednesday afternoon into the weekend where the highest concentrations are anticipated, little to no impacts are forecast beyond hazy skies. 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.
We’re in a period where a ridge of high pressure stays over the central Sahara Desert, and the Intertropical Convergence Zone (ITCZ) remains over the Gulf of Guinea.
The Harmattan wind accelerates when it blows across the mountain massifs of Northwest Africa. If its speed is high enough and it blows over dust source regions, it lifts the dust and disperses it.
Dust that makes it into the upper levels of the atmosphere can then get transported across the Atlantic Ocean and affect the Eastern Caribbean.
These Saharan Dust outbreaks tend to be milder in the Eastern Caribbean than the dust outbreaks associated with West African thunderstorms driving dust into the upper atmosphere from April through November.