Dr Jeff Masters: Super Typhoon Neoguri Lashing Okinawa, Headed for Japan

(Wunderground) The outer spiral bands of Super Typhoon Neoguri are pounding the Japanese Ryukyu Islands, which include Okinawa, as the mighty storm heads north-northwest at 12 mph towards Japan. 

At 11:30 pm local time (13:30 UTC) Monday, Naha City in southern Okinawa was reporting heavy rain and wind gusts of 43 mph. At 8 pm local time Monday, Miyako-jima reported sustained winds of 33 mph, gusting to 53 mph. On Sunday, Neoguri strengthened to 155 mph winds, crossing the 150 mph threshold needed to be labeled a Super Typhoon.

As of 8 am EDT on Monday, the typhoon had weaker slightly to 150 mph winds, and infrared satellite images showed a reduction in the intensity and areal coverage of Neoguri's heavy thunderstorms.

Recent microwave satellite images showed that the weakening may be due to the onset of an eyewall replacement cycle, a common occurrence in intense tropical cyclones. In an eyewall replacement cycle, the inner eyewall shrinks to the point of instability, collapses, and is replaced by a larger-diameter outer eyewall that forms from a spiral band. This process can take several days, and typically reduces the peak winds by 10 - 20 mph.

With wind shear light, 5 - 10 knots, sea surface temperatures a very warm 30 - 31°C, and very warm waters extending to great depth along the storm's path, the typhoon will have the opportunity to re-strengthen once the eyewall replacement cycle is done.