ROANOKE, Va. – Saharan dust plumes emerge from Africa frequently. According to NOAA’s Hurricane Research Division, these happen rather frequently late spring through early autumn. In fact, they say that it happens every three-to-five days.
However, for some of you, this is new. Let’s break down what this is not and what it is/what it means for us.
WHAT IT IS NOT
While this plume of Saharan dust is more pronounced than others, it doesn’t warrant some of the hype it’s garnered on social media. I’ve seen phrases like “Godzilla” or “dust storm” attached to this. I’ve seen many iterations of, “Ugh...2020.” Before we panic, let’s understand that this is not a dust storm like you’d see in ‘The Mummy’ or the popular Netflix show, ‘Messiah.'
The technical definition of a dust storm, or haboob, is, “An intense sandstorm or duststorm caused by strong winds, with sand and/or dust often lofted to heights as high as 1500 m (~5000 ft), resulting in a “wall of dust” along the leading edge of the haboob that can be visually stunning. There is commonly a rapid and significant reduction in visibility and an increase in wind speed following the passage of the leading edge of a haboob, which can last for tens of minutes to a few hours.” This is coming straight from the American Meteorological Society.
That is far different from what is happening with the Saharan Air Layer.
WHAT IT IS/WHAT IT MEANS
We’ll split this up into two sections; the pros vs. the cons.
The Saharan Air Layer (SAL) is a layer of dry, dusty air thousands of feet above that travels from east to west into the tropics multiple times a year. This dry air helps to reduce the chance of tropical development, which is good news for the Caribbean and Gulf of Mexico this week. The wind that accompanies this thousands of feet above us is strong enough to limit any tropical storm development too. It also helps to keep the atmosphere mostly stable.
The added particles from the dust can make for a beautiful sunrise or sunset too, as these will scatter the sun’s light around more than what you might see on a typical day.
As Puerto Rico and other islands in the eastern Caribbean have seen, enough of this dust can reduce air quality.
It’s unclear as to whether or not that will be an issue for us this weekend, but we should have a better idea the closer we get to the weekend. If anything, it may be a nuisance for those of us with asthma or other lung/heart problems.
While rain chances are limited this weekend, any pop up storm could drag some dust down to the surface. Otherwise, this mostly stays thousands of feet above us and casts some haze/dimmed sunlight over us.
This may be a new phenomena to you, but it isn’t new at all. It happens frequently, but this is more pronounced than usual. There are positive impacts from this and negative impacts as well. While it is interesting and somewhat impactful, most of us have absolutely no need to be overly concerned, worried or panicked.