Saharan dust in Houston | khou.com

HOUSTON — We’ve been tracking the Saharan dust as it heads toward the Houston area.

According to the KHOU 11 weather team, the dust is expected to hit Houston on Saturday and hang around until Monday.

The main effects of this dust layer are hazy skies, especially on Sunday and Monday, and a reduced chance of rain. Dust can also affect people with allergies.

Our air quality is expected to remain at a moderate level as there is a low concentration of dust that is about to fly over us.

Saharan dust in the atmosphere is not uncommon at this time of year.

Saharan dust comes from the Sahara Desert, but that’s only part of the equation. South of the Sahara Desert is the Sahel, a region of Africa.

The Sahel has a semi-arid climate, meaning it is desert at certain times of the year and at others it receives monsoon rains. It is monsoon rains that create dust that crosses the Atlantic and eventually reaches Texas.

What happens is that thunderstorms develop during the monsoon season, which runs from May to September, and as they do so, storms develop and as they collapse, they create flow limits. These output limits are just a big draft. As this air crosses the Sahel and enters the Sahara Desert, it collects dust. This dust rises into the air and is picked up by the trade winds and carried thousands of kilometers across the Atlantic.

High pressure over Bermuda keeps this dust south and directs it toward the Caribbean and eventually the Gulf of Mexico, which is what gives us these hazy skies.

For those with asthma and allergies, Saharan dust could be distressing. Hazy skies could really affect air quality.

On the other hand, the advantage of having dust in the atmosphere is that it stifles any tropical development due to its layer of dry air in the middle layers of the atmosphere.

In short, when the air is dry, you cannot create clouds.

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