Look up at the sky. Its a bird. Its a plane. Its Saharan dust.
While summer thunderstorms pound South Florida, an odd but regular visitor arrives in the Sunshine State this week: dust particles from the African Sahara.
Robert Molleda, a warning coordination meteorologist at the National Weather Services Miami-Dade forecast office, said we should have little to fear from the trans-Atlantic guest. The dust layer typically remains 5,000-6,000 feet above the ground and will paint the sky a milky shade, he said.
Its not a very sharp or well-defined line that will come in, Molleda said. It will be kind of a gradual transition. Wednesday well start noticing that milky or hazy appearance.
He said the most noticeable effects will occur Thursday and Friday.
Every year dust sweeps across the ocean along the trade winds and slips into the skies above Florida and many Caribbean nations. Already this year, Molleda said, there have been several instances of this dust in South Florida.
Back in June weve had a couple of occasions where minor events like this have happened, he said. This one will probably be a little bit more noticeable.
When the dust arrives, it settles into its own layer of Saharan air and stabilizes the atmosphere, reducing the amount of clouds and trapping the surface-based air into the atmospheres lower levels. That can cause irritation to people who are especially sensitive to particles in the air.
Meteorologist Chuck Caracozza said it wont affect people any more than other allergens such as pollen. And it wont cut visibility, he said.
Molleda said people who are sensitive should take precaution just in case.
Its not something where well be issuing any kind of formal alerts but people who are definitely sensitive should be careful, he said.
At the very least, the rain might stop.
A 20 percent chance of rain is expected for Wednesday and Friday, while hazy conditions will stick around Thursday -- without a chance for rain, according to the National Weather Service.
Higher temperatures are predicted as the dense Saharan layer insulates the atmosphere and suspends the mixing associated with South Floridas usual sea breeze. The stabilization will lower rain chances although temperatures will spring up to the low-90s and inland areas may experience the mid-90s.
Its going to be noticeably hotter and more uncomfortable, Molleda said. There wont be a big difference in humidity but with the higher temperatures it will give us a higher heat index.
Despite the rise in mercury, theres still reason to step outside twice a day. During sunrise and sunset hours, the sunlight passes through the extra layer in the atmosphere. This causes sunlight to reflect off the particles and stroke the sky with brilliant red and orange hues.