Trinidad and Tobago is forecast to experience a much-welcome break from Saharan Dust over the next 72 hours with decreasing concentrations due to Tropical Wave 08 and Tropical Wave 09. However, during the second half of the week, another prolonged dust surge is set to arrive.
What you need to know
— Saharan Dust Surges: A high-concentration dust surge remains across the region, with peak concentrations ending tonight (late Thursday). Reinforcing moderate to high concentration surges are forecast to arrive on late Saturday, June 11th, 2022, and late Wednesday, June 15th, 2022, following tropical waves.
— Impacts: Air quality levels across Trinidad and Tobago will vary between good to unhealthy for sensitive groups through the forecast period.
— What Should You Do: Sensitive groups should continue taking the necessary precautions, while the general population would be able to continue activities with minimal Saharan Dust safety measures.
Current AQI Levels Across T&T
The Environmental Management Agency (EMA) air quality monitoring stations at San Fernando, Port of Spain, Point Lisas, and Signal Hill are all not reporting AQI values as of 6:00 PM Sunday, June 12th, 2022. However, other air quality monitoring stations have been reporting moderate AQI values, gradually improving as Tropical Wave 08 nears.
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 between five and ten kilometers at the Piarco International Airport and A.N.R. Robinson International Airport at Crown Point, Tobago due to Saharan Dust.
Saharan Dust Forecast
Ongoing Surge: Through Early Monday, June 13th, 2022
The ongoing surge of Saharan Dust is forecast to subside by early Monday morning as deep, tropical moisture and southeasterly winds associated with Tropical Wave 08 and Tropical Wave 09 move across T&T.
Air quality levels improve to good from moderate, with the visibility outside of showers and thunderstorms remaining generally above nine to ten kilometers.
Generally, mild concentrations to no Saharan Dust are forecast across T&T through late Tuesday, with a gradual increase in dust haze on Wednesday, June 15th, 2022.
Next Dust Surge: Late Wednesday, June 15th, 2022
Forecast models indicate Tropical Wave 09 clearing the area on Tuesday, June 14th, 2022. Following the wave axis will be a moderate to high-concentration dust surge, with higher concentrations well north of T&T. Concentrations are forecast to gradually increase from early Wednesday, with peak concentrations beginning Wednesday night through Sunday, June 19th, 2022.
Air quality levels will vary from good and unhealthy for sensitive groups, with the visibility dropping as low as six to eight kilometers outside of shower or thunderstorm activity.
Longer Range: Fluctuating Dust Levels
Tropical Wave 10 (yet to be analyzed by the National Hurricane Center’s Tropical Analysis and Forecast Branch) is forecast to move across the region sometime between June 20th and 21st.
Even with this tropical wave present, Saharan Dust levels are forecast to remain at mild to moderate levels, with improvement expected in the vicinity of showers or thunderstorms. Following the passage of this wave, another moderate dust surge is forecast to move across the region by late Wednesday, June 22nd, 2022.
What does this mean for you?
The air quality will be degraded, mainly from late Wednesday, June 15th, 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.
Sensitive groups, such as children, the elderly, and persons who suffer from respiratory ailments and allergies, should avoid prolonged or heavy exertion and keep medication nearby.
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 to occur in April and continue through November.
