ST. LOUIS (KMOV.com) -- A plume of dust from the Sahara Desert in Africa will impact the St. Louis region this weekend. The dust gets picked up by the strong trade winds in the mid and upper levels of the atmosphere that move from east to west across the Atlantic.
Saharan dust plumes are not unusual, especially during the summer months in the Caribbean and sometimes southern United States. But this plume is large and the current forecast has it spreading up into the central and southeastern United States this Weekend. However, the thickest part of this dust plume and thus the bigger impacts, will be in the southern and southeastern United States.
While St. Louis will not get the thickest part of the dust plume, some impacts are possible. Watch for more hazy skies, but also this dust can produce more colorful sunrise and sunsets. We have some rain and storms in the forecast this weekend which can "clean" the air, so we'll see if any rain looks brownish, in which case it is taking dust out of the air. This dust can drift lower, making for poor air quality and impacting sensitive groups like those with respiratory issues. However, since St. Louis is not in the path of the thickest dust concentrations, this impact is uncertain and something to monitor.
Experts did say anyone with lung issues should remain indoors this weekend and run their air conditional on the "fan" setting to help filter the air.
"All the air in your house, which is only changed about 15 percent per hour, will be going through your filter," said Dr. H. James Wedner with Washington University. "The cost of that is very, very small. What costs a lot is not running the fan, it's the air conditioning. So running a fan is no different than a 60 watt light bulb. So that's going to keep most of those particles out of the air in the home."