Friday, October 11, 2013

Now THAT's a Storm!



Tropical Cyclone Phailin, currently in the Bay of Bengal, will make landfall in northeast India tomorrow. Dr. Jeff Masters' WunderBlog tells the story:
Very dangerous Tropical Cyclone Phailin, in the North Indian Ocean's Bay of Bengal, has put on an impressive burst of rapid intensification, going from a tropical storm with 65 mph winds to a formidable Category 3 storm with 115 mph winds in just twelve hours. Satellite estimates of Phailin's strength at 8 am EDT ranged as high as 135 mph. Satellite images show that Phailin, whose name means "a sapphire" in Thai, continues to intensify. The cloud tops of the very intense thunderstorms in the eyewall are expanding and cooling, showing that their updrafts are growing stronger and pushing the clouds higher into the atmosphere. Water temperatures are warm, 28 - 29°C, and the ocean heat content is very high, 80 - 100 kJ/cm^2--a level often associated with rapid intensification. With wind shear low, Phailin should be able to continue to intensify until an eyewall replacement cycle begins. It is very difficult for a tropical cyclone to maintain an eye diameter less than ten miles across before the inner core grows unstable and the eyewall collapses, with a new, larger-diameter eyewall forming from an outer spiral band. This process typically weakens the top winds of a tropical cyclone by 5 - 15 mph, but spreads hurricane-force winds over a larger area of ocean, resulting a larger storm surge, but less wind damage. With Phailin's eye diameter already down to a tiny 9 miles, an eyewall replacement cycle is likely to occur by Friday morning.

The models are in tight agreement that Phailin will track northwest into the northeast coast of India, with landfall expected to occur between 06 - 12 UTC on Saturday. The 11 am EDT Thursday forecast from the Joint Typhoon Warning Center predicts that Phailin will peak as a top-end Category 4 storm with 155 mph winds 12 hours before landfall
Dr. Masters provides a list of the 35 Deadliest Tropical Cyclones in World History.  So far, only one has been in the 21st century.

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