Dust storm hovers over Sana’a [Archives:2007/1030/Front Page]

March 5 2007

Nadia Al-Sakkaf
SANA'A, March 4 ) A large-scale dust storm coming from the Arabian desert's Al-Rub Al-Khali (the Empty Quarter) reached Yemen a couple of days ago and is still quite visible today on Sana'a skies according to locals.

The Civil Aviation & Meteorology Authority's Yemen Meteorological Service warned citizens with breathing problems about the current weather, advising them to stay indoors until the storm subsides. Long-distance drivers also should take care on roads, as vision has decreased to less than 500 meters ahead, the authority added.

Abdulqadir Al-Sahli a specialist at the authority explained that the dust storm occurred due to the changing season, often characterized by sustained high winds on the earth's surface, which often are associated with wind storms. He added that dust storms are a natural event in this part of the world.

Although, this storm has been classified by local weather experts as relatively mild, yet it affects people who have asthma or allergies to dust. High change in pressure gradient from the valleys to mountain areas cause the storm to become stronger picking up dirt and small pieces of garbage and plastic bags.

Such dust storms can last three to four hours, or up to two to three days, depending on the situation. Dust storms of this type often occur in late winter to early spring when there's an extreme pressure gradient. They often worsen in late morning and are more intense in the late afternoon. If a dust storm lasts more than a day, its intensity tends to weaken throughout the night.

According to U.S. weather specialist Gene Moore, a dust storm essentially is caused by strong winds traveling over dry, arid land with little vegetation, picking up tiny particles like sand, dust and other debris.

Areas of land become susceptible to erosion by high winds when the ground becomes bare, which can be caused by poor land management either involving agriculture or overgrazing.

Dust and debris carried by the wind form a large cloud or wall of dust that sweeps across the landscape with the wind.