Weather experts: Sahara dust diminishing cyclone activity

Yellow, orange and red indicate dust movement from Africa towards the Caribbean as of 15 Aug. - Image: University of Wisconsin-Madison

Movement of dry air and dust from the Sahara desert is keeping the Caribbean hurricane season at bay – for now.

Drought conditions in the Sahara have produced a significant plume of dust in recent days that has extended to much of the eastern Caribbean, including Cuba, Haiti and the Dominican Republic.

For the time being, the dry air appears to be suppressing hurricane activity, explained climate scientist Jhordanne Jones of Colorado State University’s Tropical Meteorology Project.

“There is a huge plume of Saharan dust that’s directly over the Caribbean. It hasn’t extended as far as Cayman, although you may be impacted as well,” Jones said, adding that the flow of winds around Cayman and Jamaica is currently counteracting the westward movement of the dust.

The Saharan dust and air have a drying effect on the environment, Jones said, diminishing the moisture necessary for cyclone formation.

Dust and wind shear conditions are expected to stifle cyclone activity through the weekend. Forecasters anticipate conditions to change around 18 Aug., however.

“Indications are that inhibiting factors for tropical development, such as dry air, dust and strong wind shear over the Atlantic basin will start to relax during the week of Aug. 18‑25,” said AccuWeather hurricane expert Dan Kottlowski.

AccuWeather advised that during mid-summer, moist air in the region tends to become more plentiful while dust and wind shear tend to diminish.

“How fast these inhibiting factors relax next week will determine if and when a particular disturbance develops,” Kottlowski said in an AccuWeather post.

CSU meteorologist Phil Klotzbach posted on Twitter Thursday that the Atlantic has only had one named storm, Hurricane Barry, since 1 June – the fewest number of named storms between 1 June and 15 Aug. since 1999.

“The Atlantic has had no named storm activity since Barry on July 14, and the National Hurricane Center forecasts no new named storms in next 5 days. The last time that the Atlantic went from July 15 through August 19 with 0 named storms was 1982,” Klotzbach posted on Wednesday.

The National Hurricane Center is forecasting 10 to 17 named storms, including five to nine hurricanes, this season. CSU forecasters are predicting 12 named storms, including six hurricanes. So far, the season has produced two named storms – Subtropical Storm Andrea and Hurricane Barry.

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