Dust and sand storms

Meteorological dynamics for dust storm initiation over the Arabian Gulf are attributed to upper-air short wave movements from the eastern Mediterranean. The surface thickness layer of the entrained dust depends on the vertical motion of the two pressure systems near the region. It normally takes about 12 to 24 hours for air-suspended dust to spread over the Arabian Gulf, with the timing primarily dependent on wind flow strength and the upper air jet streams. The dust reaches the United Arab Emirates coast with slight effects on horizontal visibility, which falls below 5000 meters for hours.

Dust and sand storms prevailing over the area primarily originate from south western Iraq. In satellite images, certain points in the Iraqi desert and west of the Euphrates River can be identified as main sources of dust storms. Shamal velocities greater than 20 knots (about 10 m/s) are required to entrain dust and transport it southward. Soil and air dryness, strong winds, and high surface temperatures are key factors for initiating dust storms.

Thunderstorms and rainfall

Little precipitation falls on the Arabian Gulf region during the summer. However, upper level troughs may contribute to the production of light to moderate thunderstorms in the northern parts. An average of three strong surface troughs enter the Arabian Gulf region in November, and rainfall amounts increase due to the strength and frequency of cyclonic activity across its northern parts.

Precipitation is more frequent during the winter. Rainfall is normally associated with the presence of a subtropical jet stream over Arabia. Isolated thunderstorms near surface low-pressure centers along the cold front may develop between December and March. This effect is pronounced when Mediterranean Sea depressions are associated with a mid-or upper-level trough which dictates the strength of the system. In spring, cyclonic activities are more frequent, and isolated thunderstorms are produced by the surface-low passages over the Arabian Gulf. Surface heating reaches a maximum in April and May, when thunderstorms reach their annual peak, and can be exceptionally strong along an active cold front.