Adapted : Thursday, June 20, 2019,
Nearly all islands across the Lesser Antilles are experiencing air quality levels that are unhealthy for sensitive groups, with the most reduced air quality occurring across Barbados and Martinique as of 11:00 AM. Dense Saharan Dust continues to traverse the Atlantic and Caribbean as all islands across the Greater Antilles, stretching as far as Florida into the United States, are experiencing moderate air quality. Across Trinidad and Tobago, air quality is beginning to deteriorate rapidly, but generally still at good to moderate levels. Persons with respiratory ailments, heart disease, the elderly and children need to take the necessary precautions!
Presently, minimal to mild concentrations of Saharan Dust are present across Trinidad and Tobago, with air quality at good levels across Western and Central Trinidad. Across Eastern Trinidad and Tobago however, a combination of model data and ground stations are indicating air quality is beginning to be quickly degraded, presently at moderate levels.
According to the EMA, the national standard for Particulate Matter (PM) of diameter ≤2.5 µm (PM2.5) is 65 µg/m3 and PM of diameter ≤10 µm (PM10) is 75 µg/m3. This has not been exceeded since the March 2019 Saharan Dust Outbreak. Based on present model guidance, this event is expected to become close or just over the PM2.5 threshold at 62-66 µg/m3 at its peak early Friday morning across Trinidad and Tobago.
In addition, with breezy conditions, and gusts to 60 KM/H, a significant reduction in visibility is forecast out at sea. Marine interests are advised to exercise extreme caution as seas still remain moderate, with waves between 2.0 to 2.5 meters in open waters.
All Lesser Antilles Islands are experiencing air quality levels at unhealthy for sensitive groups, with the exception of Trinidad and Tobago. Countries along the Northern coast of Southern America are experiencing good air quality, while all Greater Antilles islands, stretching as far west as the United States, are experiencing moderate air quality.
At moderate air quality levels, unusually sensitive groups should consider reducing prolonged or heavy exertion.
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.
Dust models continue to show, following the passage of tropical waves, moderate concentrations of Saharan Dust moving across Trinidad and Tobago over the next several weeks. Based on the latest model guidance, following this significant surge over the next 24-36 hours, another moderate surge is forecast by June 25 and another by June 30.
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 to unhealthy for sensitive groups.
