How does Saharan dust affect tropical development?

Dry air added to the atmosphere by dust can impact tropical formation

Saharan dust below Tropical Storm Don in the north-central Atlantic. Credit: NOAA.

While Saharan dust often adds a haze to the sky, can affect air quality, and make for aesthetic sunsets, plumes can also affect tropical development during hurricane season.

Key Points

  • Saharan dust can inhibit tropical development
  • Plumes consist of drier air, which works against tropical cyclone formation
  • Saharan dust is working through South Central Texas over the next few days (7/26 - 7/28)
  • We’ll see a haze in the sky, but major issues to air quality are *not* expected
  • This plume filters out of the area this weekend

The sky will likely look a bit hazy at times this week as another plume of Saharan dust filters across the South Central Texas sky. The good news: major air quality issues are not expected in San Antonio this go around!

More good news: Saharan dust can often work against tropical development during hurricane season, suppressing activity. Here’s how:

Saharan dust vs. the tropics

While the peak of hurricane season isn’t until September, July has been fairly quiet in terms of tropical activity in the Atlantic despite warmer-than-average sea surface temperatures.

Plumes of Saharan dust filtering off the coast of Africa have helped to suppress some of that development, due to the drier layer of air it adds to the atmosphere. We didn’t see a whole lot of dust filter across the Atlantic in June, but bigger concentrations of dust finally started to emerge in July.

Tropical systems need moist, humid air to sustain themselves and strengthen. The dry air that the SAL (Saharan Air Layer) brings to the atmosphere can help inhibit that formation and intensification with a more stable airmass in place.

Tropical Storm Don was the only tropical storm to form in July, and did so well north of a Saharan dust plume where more humid air was in place. That storm has since dissipated, with the next name up for grabs on the list being Emily.

The list of Atlantic tropical cyclone names for the 2023 hurricane season.

Tropical Outlook (As of 7/26)

As of the latest outlook from the National Hurricane Center (NHC), there is one area to watch in the Atlantic as a disturbance emerges off the coast of Africa.

NHC forecasters have given this tropical wave a low (30% chance) of tropical development over the next seven days as it moves northwest over the warm ocean waters just north of the Lesser Antilles.

It looks like another plume of dust will also emerge off the African coastline in the coming days, so we’ll see how that all shakes out.

No concerns are currently in place for us here in South Central Texas when it comes to the tropics, but we’ll continue to monitor things over the next few months!

No concerns for South Central Texas, but the NHC has given a tropical wave in the eastern Atlantic a low chance of development over the next week.

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About the Author:

Meteorologist Mia Montgomery joined the KSAT Weather Authority Team in September 2022. As a Floresville native, Mia grew up in the San Antonio area and always knew that she wanted to return home. She previously worked as a meteorologist at KBTX in Bryan-College Station and is a fourth-generation Aggie.