ORLANDO, Fla. – The tropics remain active with Grace and Henri churning in the Caribbean and Atlantic respectively. A late-season ejection of dust from the Sahara Desert, however, could help to calm the tropics down in the short term.
The dust will spread west into the Caribbean and southwest Atlantic along a strong area of high pressure, the same weather feature that pushed Grace south, keeping it away from Florida. This could be the most significant plume of dust of the season for Florida and the southwest Atlantic.
You may notice the dust’s presence by more vibrant sunrises and sunsets when it arrives early next week. The most prolific round of dust looks to arrive late Tuesday into Wednesday. The dust hangs out thousands of feet in the air, but its arrival may also bring poor air quality for extremely sensitive groups and enhanced allergy symptoms.
The dust will also help to keep rain and storm chances on the lower side next week which will also keep temperatures high.
Typically the dust is most prolific in June and July and is one reason the tropics are relatively tame in those months.
Most of the storms that have originated from Africa this season have come off the continent farther south than the current plume of dust, so developing storms from Africa may escape the dry, dusty air initially.
However, if any systems that try and make the trans-Atlantic journey west stay on the weaker side as they approach the U.S., the dust could make it harder for those systems to get stronger.
The steering currents transporting the dust to Florida will have to be monitored closely as storms will have a higher-than-normal chance to impact the U.S. with the aforementioned setup. There are long-range indications that higher-than-normal pressure will build in the northeast U.S. and southern Canada which could steer tropical systems uncomfortably close to the U.S. mainland.