Saharan Dust levels remain elevated across the Windward Islands, including Trinidad and Tobago, following a major surge that moved across the area last week. Forecast models indicate another moderate to high concentration surge is set to move across the southern half of the Lesser Antilles this week with elevated dust levels through mid-month.
It should be noted that the upcoming dust surges are not forecast to be as intense as the one that affected T&T between January 30th through February 2nd, where air quality remained unhealthy for nearly 24 hours.
What you need to know
— Saharan Dust Surges: A moderate to high concentration surge of Saharan Dust is forecast to move across Trinidad and Tobago, spreading across the Lesser Antilles from Thursday, February 8th, 2024. Another reinforcing moderate to high dust surge will move across T&T from Saturday night, February 10th, 2024.
— Impacts: Over the next ten days, air quality across T&T will range between moderate and unhealthy for sensitive groups. During peak concentrations, mainly from Saturday night, and in the vicinity of blowing smoke near fires, air quality is likely to be reduced to unhealthy.
— What Should You Do: In times of unhealthy air quality, everyone should take the necessary precautions. Throughout the forecast period, unusually sensitive groups are advised to take the necessary precautions, particularly during high traffic and in the vicinity of fires.
Current AQI Levels Across T&T
The official air quality monitoring stations from the Environmental Management Agency (EMA) at Beetham, Port of Spain, and San Fernando are reporting moderate air quality levels, while at Mayaro, Toco, and Point Lisas, good air quality is being reported, but these readings are on the border of becoming moderate. As of Monday afternoon, the stations at Signal Hill, Tobago, and Arima are not reporting PM2.5 or PM10 data.
Unofficial air quality monitoring stations at St. Augustine and Woodbrook are reporting moderate air quality, while at Longdenville, air quality is unhealthy for sensitive groups.
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 has remained at 10 kilometers at both the A.N.R. Robinson International Airport at Crown Point, Tobago, and the Piarco International Airport, Trinidad.
Saharan Dust Forecast
Monday (Feb. 05) through Wednesday (Feb. 07): Mild to moderate Saharan Dust concentrations present across T&T and the Lesser Antilles, increasing from Tuesday night. Air quality: Good to moderate, dipping to unhealthy for sensitive groups to unhealthy in high traffic and near fires/blowing smoke.
Thursday (Feb. 08) through Wednesday (Feb 14th): Moderate to high concentrations of Saharan Dust across T&T and the southern half of the Lesser Antilles. Air quality: moderate to occasionally unhealthy for sensitive groups, dipping to unhealthy in high traffic and near fires/blowing smoke.
Over the next ten days, air quality across T&T will range between moderate and unhealthy for sensitive groups. During peak concentrations, mainly from Saturday night, and in the vicinity of blowing smoke near fires, air quality is likely to be reduced to unhealthy.
What does this mean for you?
Everyone may begin to experience health effects, and members of sensitive groups may experience more serious health effects. Everyone should take the necessary precautions, particularly when peak concentrations are forecast.
From February 2nd, air quality is forecast to gradually improve across Trinidad and Tobago as higher concentrations of Saharan Dust move westward. However, with elevated concentrations still present and drier conditions bringing the risk of fires, air quality is still forecast to be reduced, with further reductions in localized areas of fires, blowing smoke and dust, and high traffic.
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.
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.
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.
