Mild Concentrations of Saharan Dust Forecast to Increase Overnight, Lingering Through The Week

Most islands across the Eastern Caribbean are experiencing good air quality levels, based on U.S. standards as of 11:00 AM Monday 19th August 2019. A mild surge of Saharan Dust is nearing the Eastern Caribbean, bringing hazy skies and slightly reduced air quality, mainly north of T&T, beginning overnight tonight. Air quality may briefly dip to moderate levels, through Thursday across T&T, returning to good levels by Friday. Another surge of dust is forecast by the end of the upcoming weekend, with more concentrated dust remaining north of T&T.

Presently, minimal concentrations of Saharan Dust are present across Trinidad and Tobago, as well as the Eastern Caribbean, with air quality between good and moderate levels.

Note that the Environmental Management Agency (EMA) air quality monitoring stations are presently recording AQI values at good and moderate levels, based on T&T’s air quality standards, while other air quality monitoring stations are reporting air quality at good levels, based on United States standards.

Visibility across Trinidad and Tobago remains at 10 Kilometers and above.

Air Quality Index at Environmental Management Agency‘s (EMA) Air Quality Monitoring Stations Across Trinidad. Note these AQI values are to Trinidad and Tobago air quality standards.

What we expect

Based on the latest dust modeling, dust concentrations are forecast to peak on Tuesday and Wednesday across Trinidad, Tobago, and the Lesser Antilles, decreasing in concentrations on Thursday as a weak tropical wave approaches the region.

00Z August 19th, 2019 CAMS Copernicus Atmospheric Monitoring Tropical Atlantic Dust Aerosol Optical Depth showing a surge of Saharan Dust moving across the Eastern Caribbean, mainly across islands north of T&T. Credit:

However, following this wave, a more significant surge of dust is forecast to move across the Lesser Antilles, with the highest dust concentration moving across the Leeward Islands.

5-Day Air Quality Index (based on United States EPA Standards), Saharan Dust Forecast For Trinidad and Tobago. Saharan Dust is forecast to be mild to minimal across Trinidad and Tobago over the next 5 days.

Generally, through the next 5 days, air quality is forecast to fluctuate between good and moderate levels.

What does this mean for you?

For the general population, little to no impacts are forecast. 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. Mild to minimal concentrations of Saharan Dust forecast. See below for more detail.

Good Air Quality

Good Air Quality

AQI – 0 to 50

What does this mean for you?

At this level, air quality is considered satisfactory, and air pollution poses little or no risk to public health. It’s a great day to be active outside.

Who needs to be concerned?

No one.

What should you do?

Sensitive Groups: Sensitive groups, children and the elderly do not need special protection.

Air purification: It is recommended to run an air purifier in auto-mode, so it automatically reacts to changes in air quality.

Ventilation: It is good for ventilation.

Masks: No masks are needed.

Outdoor Activity: Very suitable for outdoor exercise and activities.  

Moderate Air Quality

Moderate Air Quality

AQI – 51 to 100

What does this mean for you?

Air quality is acceptable; however, for some pollutants, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.

Who needs to be concerned?

Unusually sensitive people: Consider reducing prolonged or heavy exertion. Watch for symptoms such as coughing or shortness of breath. These are signs to take it easier.

Everyone else: It’s a good day to be active outside.

What should you do?

Sensitive Groups: Sensitive groups such as those with respiratory ailments, children and the elderly are advised to reduce outdoor physical exertion, and reduce the time of their stay outdoors, especially in areas with heavy traffic.

Air purification: At this level, the air is slightly polluted. It is recommended to turn on your air purifier, running at a low level, at a minimum.

Ventilation: Please close windows, as the air is slightly polluted.

Masks: Wearing a mask during outdoor activity is recommended, particularly in areas with heavy traffic.

Outdoor Activity: It is recommended to stay indoors and avoid outdoor exercise.

The concentration of the dust that follows the wave depends on the strength of the wave 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.

Larger, more concentrated plumes of Saharan dust begin to occur in April and continue through November.

We’re in a period where the ITCZ shields 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, as we move through July into September, these frequent tropical waves also aid in improving air quality.

Sensitive groups such as persons with respiratory ailments, children, the elderly and cardiopulmonary disease should take the necessary precautions on days where dust concentrations degrade air quality to moderate.

Saharan Dust Precautions
Saharan Dust Precautions
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