A 2,000 Mile Saharan Dust Cloud Is Approaching Texas and Florida

Mint

6 days ago

(Bloomberg) -- A swirling gray haze forced Claribel Ramirez to shut her house to block out the fine grit that settled on every flat surface in Puerto Rico. The culprit? A 2,000-mile dust plume blown off Africa's Saharan Desert and sent across the Atlantic where it will reach Florida and possibly even Texas later this week.
There, it will turn the sky a dull gray during the day and possibly provide some dazzling sunsets. And if the winds mix it down to the surface, the grit will make people sneeze, wheeze and plead for relief from the allergens and grime.
That's been Ramirez's experience: 'My nose is running like a garden hose. I can't take this too much longer.'
Thunderstorms and the jostling position of a weather pattern known as the Bermuda-Azores high have helped lift tons of dust and dirt from the Sahara and sent it swirling across the Atlantic. The process plays out every year, though some years see more dramatic plumes than others. The billowing clouds tend to peak between June and July, and NASA said 100 million tons of dust can be sent around the globe each year, reaching parts of Europe in addition to the US.
When the dust reaches the surface, as is happening on Puerto Rico, it can be a health hazard for people who inhale it, according to the US Centers for Disease Control and Prevention. Fine particles enter the bloodstream, triggering asthma attacks and 'aggravating other respiratory conditions,'' such as those plaguing Ramirez.
There are some upsides to the dust, though. For one, it can help fertilize the Amazon rainforest by transporting minerals such as iron and phosphorus, research shows. The sunsets can also be spectacular if enough dust stays aloft because it scatters blue light, leaving more dazzling oranges and reds, according to the National Weather Service.
For those living in hurricane-prone areas, the dust also holds another benefit. The plumes — and the dry Saharan air that transports them — make it hard for storms to form. Hurricanes are born from moist air and draw power from the ocean itself. But the arid air cuts off would-be storms' fuel and shrivels thunderstorms that are the building blocks of tropical systems.
The central Atlantic is particularly susceptible to the impacts of Saharan dust. That stretch of ocean, which meteorologists call the main development region, is where some of history's worst hurricanes have spun up. Yet it's typically quiet early in hurricane season, which begins on June 1, thanks in part to the dry air.
Saharan dust eruptions can come every three to five days and typically peak in June to mid-August, according to NOAA. Even so, some storms find gaps in the dust and manage to tap into the warm Atlantic water and burst onto the scene. That happened a year ago when Hurricane Beryl, which killed at least 69 people, formed in late June and became the earliest storm to reach Category 5 strength in the Atlantic. Once the dust starts to die down in mid-August, the main development region becomes much more conducive to spinning up monster storms.
At this time of year, storms in the Atlantic tend to cluster around the shores of North America and the western Caribbean Sea. The US National Hurricane Center is tracking a potential storm that may grow out of a weather front off the coast of South Carolina in the coming week. The odds of it forming into a tropical system remain low, though. For now, the brakes are on across the central Atlantic as the 750-mile-wide plume pulses across the hemisphere.
'It is pretty impressive,' Alex DaSilva, a meteorologist with commercial forecaster AccuWeather Inc., said of the dust. 'It is the strongest one of the year so far.'
The dust is a sign summer is arriving in North America, and it comes as another harbinger of seasonal change has also arrived — Canadian smoke. While the dust will impact the Southeast, smoke from massive Canadian wildfires has drifted across the US border, leading to air quality alerts in Wisconsin, Minnesota and parts of Michigan.
The clouds of smoke high in the atmosphere have also reached the US East Coast, according to FireSmoke.ca, a Canadian academic and government website. By this coming weekend, the mainland US will be bracketed by smoke to the north, dust to the south and thunderstorms stuck in the middle.
More stories like this are available on bloomberg.com