Cyclone Gonu is going to pass the Omani capital of Musqat at fairly close quarters tonight, with winds at hurricane force (65 to 75 knots) near the centre, and up to 50 knots in the city itself. The cyclone has been extra-ordinary in its strength, a category 5 hurricane, and the rate at which it LOST its strength as well. There are four reasons for it to degrade so rapidly.
Hurricanes feed of heat and moisture in the ocean, which needs to have water temperatures of 26C / 79F or warmer. Gonu was in waters of up to 31C / 88F until yesterday. However, the rot set in when it approached the Arabian peninsula, which is of course extremely dry, and the air entrained from there was very dry. The ocean became quite shallow, meaning that any heat sucked up by the cyclone was rapidly used up. Winds are hampered by land, as well. Another reason is a disparity in windspeeds at different heights in the atmosphere, a phenomenon called windshear. When this happens, the vertical circulation in the cyclone is disrupted, and shear of more than 20 knots means the system gets ripped apart.
Gonu will track northwest through the Gulf of Oman and slip ashore in southern Iran late on Friday - as little more than a depression with barely galeforce winds.
My TC blog attracted 3,187 viewers yesterday, and had 955 up to now today.
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I'm so thankful I live where we don't have to worry about hurricanes. Although sometimes there are heavy winds (like last Dec 14th) that make you think you're living in a hurricane zone. Linda in Washington
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