Trinidad, Tobago, and most of the Southern Windwards will see mostly good air quality through the weekend as back-to-back tropical waves and the Intertropical Convergence Zone keep Saharan Dust levels at bay. One of these tropical waves is being monitored by the National Hurricane Center for tropical cyclone development.
By the start of the upcoming week, a moderate to high concentration surge of dust is forecast to arrive across the Lesser Antilles, reducing air quality.
What you need to know
— Saharan Dust Surges: While no major or significant surges are forecast to affect T&T through the weekend, a moderate to high concentration surge of Saharan Dust is forecast to arrive across T&T on Monday, August 29th, 2022, with fluctuating concentrations through the upcoming week.
— Impacts: Air quality levels across Trinidad and Tobago will vary between good and moderate through the forecast period. Rainfall will also lead to air quality improvements in localized areas next week.
— What Should You Do: From Monday, August 29th, 2022, sensitive groups should take the necessary precautions. The general population will remain unaffected.
Current AQI Levels Across T&T
The Environmental Management Agency (EMA) air quality monitoring stations at San Fernando, Signal Hill, and Port of Spain have recorded good to moderate air quality levels over the last 24 hours. No data was reported at Point Lisas.
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 near or above ten kilometers at the Piarco International Airport and A.N.R. Robinson International Airport at Crown Point, Tobago, outside of shower and thunderstorm activity.
Saharan Dust Forecast
Next Surge: Monday, August 29th, 2022
Following the passage of Tropical Waves 32 and 33 over the weekend, a moderate to high concentration surge of dust is set to arrive on Monday, August 29th, 2022. Peak dust levels across the region are forecast on Wednesday, August 31st, 2022, with higher concentrations north of Trinidad and Tobago. Concentrations are forecast to gradually diminish during the latter half of the upcoming week, with isolated showers and thunderstorms providing localized air quality improvement.
Air quality levels will vary from good to moderate across T&T, at times dipping to levels that are unhealthy for sensitive groups by Wednesday, August 31st, 2022, with visibility generally remaining near or above eight kilometers outside of shower or thunderstorm activity.
Dust levels are forecast to return to minimal levels by next weekend.
What does this mean for you?
The air quality will be degraded from Monday, August 29th, 2022. During high traffic periods, particularly between 6:00 AM and 9:00 AM, and again from 3:00 PM through 6:30 PM, air quality may be further reduced in localized areas.
According to the Trinidad and Tobago Meteorological Service, “the 2022 Saharan Dust Haze Season is likely to peak from June to August with the number of Saharan dust haze days expected to increase significantly. The duration of the plumes of Saharan dust haze visiting both islands is also likely to be more prolonged than earlier in the year, with increased odds for higher dust haze concentration during plumes visitation.”
We’re in a period where the Intertropical Convergence Zone and tropical waves may 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 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.