A vast cloud of Sahara dust blanketing Havana, Cuba, as people fish on Wednesday. Photo: Yamil Lage/AFP via Getty Images

A giant, dense plume of Saharan dust is shrouding much of the Caribbean as it heads westward toward Central America and the southern U.S. this week.

Why it matters: The dust cloud blanketing Puerto Rico, Jamaica, Hispaniola, and eastern Cuba on Tuesday prompted authorities to issue health warnings across the region as air quality plummeted to unhealthy levels, per Reuters.

  • Pablo Méndez Lázaro, from the University of Puerto Rico's School of Public Health, told AP, "This is the most significant event in the past 50 years. Conditions are dangerous in many Caribbean islands."
  • Aallergist and American College of Allergy, Asthma and Immunology president J. Allen Meadows said in a statement on Tuesday that dust storms and air pollution "can make asthma symptoms worse and make breathing more difficult."

The big picture: Per the NOAA, the Saharan Air Layer (SAL) is a mass of "very dry, dusty air" that forms over the Sahara Desert in northern Africa.

  • SAL outbreaks usually occupy a two- to 2.5-mile-thick layer of the atmosphere with the base starting about one mile above the surface. It reduced visibility in some areas to five miles when it reached the eastern Caribbean over the weekend, per a NOAA statement.
  • "The main impacts of the Saharan dust are a whitening of the sky during daylight hours, redder sunsets, and decreased air quality," NOAA said in a statement on Tuesday.

What to expect The Saharan dust layer is due to hit the Florida Peninsula and Gulf Coast "in the coming days," according to NOAA's Storm Prediction Center.

  • In a statement posted to Twitter, Sonoma Tech meteorologist Jeff Beamish pointed to modeling showing SAL impacts for Texas and Louisiana by Thursday, "potentially spreading" into the central and eastern US by Saturday.

Go deeper

The 2010s were officially the hottest decade on record

Residents defend a property from a bushfire at Hillsville near Taree, north of Sydney in Australia on Nov. 12. Photo: Peter Parks/AFP via Getty Images

It's official: Last year was the world's second hottest on record, and 2010-2019 was the hottest decade ever recorded.

Why it matters: The findings, published in two separate reports by NOAA and the British weather service the Met Office Wednesday, are in line with those of research group Berkeley Earth, revealed at the start of the year. It's yet more evidence of the long-term warming trend that stems from human-induced greenhouse gas emissions.

Updated 1 hour ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 12 p.m. ET: 12,772,755 — Total deaths: 566,036 — Total recoveries — 7,030,749Map.
  2. U.S.: Total confirmed cases as of 12 p.m. ET: 3,269,531 — Total deaths: 134,898 — Total recoveries: 995,576 — Total tested: 39,553,395Map.
  3. Politics: Trump wears face mask in public for first time.
  4. States: Florida smashes single-day record for new coronavirus cases with over 15,000.
  5. Public health: Trump's coronavirus testing czar says lockdowns in hotspots "should be on the table" — We're losing the war on the coronavirus.
  6. Education: Betsy DeVos says schools that don't reopen shouldn't get federal funds — Pelosi accuses Trump of "messing with the health of our children."
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Florida smashes single-day record for new coronavirus cases

Data: Covid Tracking Project; Chart: Axios Visuals

Florida reported 15,299 confirmed coronavirus cases on Sunday — a new single-day record for any state, according to its health department.

The big picture: The figure shatters both Florida's previous record of 11,458 new cases and the single-state record of 11,694 set by California last week, according to AP. It also surpasses New York's daily peak of 11,571 new cases in April, and comes just a day after Disney World reopened in Orlando.