After six days without Saharan Dust across Trinidad and Tobago, mild concentrations are on the increase across the southern Windward Islands over the weekend. Through the next ten days, no major dust surges are forecast.
What you need to know
— Saharan Dust Surges: A mild surge of Saharan Dust is forecast to move across the Lesser Antilles, including Trinidad and Tobago, from late this evening, Friday, February 3rd, 2022. This surge will linger through the weekend, with a relatively dust-free atmosphere until Wednesday, February 8th, 2023.
— Impacts: Through the next seven to ten days, air quality levels across Trinidad and Tobago are forecast to be between good and moderate.
— 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
All official air quality monitoring stations from the Environmental Management Agency (EMA) at Arima, Port of Spain (Beetham), Point Lisas, and San Fernando are reporting good air quality levels, with the station located at Signal Hill, Tobago, not reporting data.
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 unaffected by Saharan Dust at the Piarco International Airport and the A.N.R. Robinson International Airport at Crown Point, Tobago.
Saharan Dust Forecast
Next Surge: Late Friday, February 3rd, 2023
A mild concentration surge of dust is forecast to move across Trinidad, Tobago, and the remainder of the Lesser Antilles from tonight, Friday, February 3rd, 2023. Decreasing concentrations are forecast through the weekend, with minimal concentrations by late Sunday, February 5th, 2023.
Air quality levels will fluctuate between good and moderate. However, elevated low-level winds will quickly push air pollution westwards.
Surge #2: Wednesday, February 8th, 2023
Another brief and mild Saharan Dust surge is forecast to move across the Lesser Antilles, including Trinidad and Tobago, from Wednesday, February 8th, 2023, through Saturday, February 11th, 2023. Air quality levels will fluctuate between good and moderate.
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.
The surges of dust during this time of year are due to the Harmattan, a season in the West African subcontinent that occurs between the end of November and the middle of March. During this season, a predominant northeasterly trade wind (dubbed the Harmattan Winds) blows from the Sahara Desert over Western Africa into the Gulf of Guinea.
During this period, 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.
