Tropical Cyclones - 13 July

Tropical Storm Bilis is going to hit Taipei within the next 12 hours, packing winds of 55 knots (force 11), gusting to near hurricane force. The storm will pass to the northwest, hitting mainland China before fizzling out. Tropical storms do not survive long over land, as they are deprived of their prime source of energy: warm seawater.

On the eastern side of the Pacific, Hurricanes Bud is at its peak, blowing at speeds of 100 knots (125 mph), with gusts to 120 knots (150 mph). Bud is in the middle of nowhere, at position 17.5N 120.5W and moving west at 15 knots, 20 mph. Yesterday's picture showed a distinct eye.

Further east, Hurricane Carlotta is building up to its full strength, which is likely to be equal that of Bud. Carlotta is at position 16.4N 109.4W , and heading west at 13 knots, 15 mph. Carlotta too is in the middle of the open ocean.

Tropical cyclones are devastating if over land and typhoon Ewiniar (now disappeared) generated waves at sea of 39 ft, 12 m. They are necessary safety-valves for the earth's atmosphere, to transfer the energy from the sun from the tropics to more northerly latitudes. They need seawater temperatures of 27 C / 80 F or more to be generated and sustained. Off Mexico, the sea is at 30C.

There are at present no cyclones over the Atlantic, as the atmospheric conditions are not right. For a start, a layer of dust from the Sahara is blocking the sun's rays. Another reason lies in the position of a pattern of circulation which carries the water vapor from the oceans around; for cyclones to be born, it needs to be over open water. Currently, it lies over continental South America.

Parts of this information courtesy www.bajainsider.com and www.nhc.noaa.gov.

An in-depth explanation of these phenomena can be found on the Jetstream webpage, which I recommend for all interested in and/or affected by tropical hurricanes.