A large dust cloud from the Sahara Desert has traveled over the Caribbean. This is the biggest event of its kind this year, and it is now moving towards the US. The dust cloud covers 3,200 km from Jamaica to Barbados and 1,200 km from the Turks and Caicos Islands to Trinidad and Tobago. Because there is a lot of dust, health warnings have been issued, as it can cause sneezing, coughing, and watery eyes. This Saharan Air Layer forms over the Sahara Desert and moves west across the Atlantic from April to October. It can also prevent tropical storms from forming during hurricane season. The dust cloud is expected to reach Florida, Louisiana, Alabama, and Mississippi later this week. Last June, a very large Saharan dust cloud covered the Caribbean. This was the biggest event in fifty years.