Wunderground.com by Dr. Jeff Masters - 9 November 2013
Figure 1. Super Typhoon Haiyan approaching the Philippines, as seen by the Japan Meteorological Agency's MTSAT at 0630Z on November 7, 2013. At the time, Haiyan had maximum sustained winds of 175 mph. Image credit: NOAA Environmental Visualization Laboratory.
After spending 48 hours at Category 5 strength, the strongest landfalling tropical cyclone in world history, Super Typhoon Haiyan, has finally weakened to a Category 4 storm. With top sustained winds of 155 mph, Haiyan is still an incredibly powerful super typhoon, but has now finished its rampage through the Central Philippine Islands, and is headed across the South China Sea towards Vietnam. Satellite loops show that Haiyan no longer has a well-defined eye, but the typhoon still has a huge area of intense thunderstorms which are bringing heavy rains to the Central Philippines. I've never witnessed a Category 5 storm that made landfall and stayed at Category 5 strength after spending so many hours over land, and there are very few storms that have stayed at Category 5 strength for so long.
Haiyan's place in history
Haiyan hit Guiuan, on the Philippine island of Samar, at 4:40 am local time (20:40 UTC) November 7, 2013. Three hours before landfall, the Joint Typhoon Warning Center (JTWC) assessed Haiyan’s sustained winds at 195 mph, gusting to 235 mph, making it the 4th strongest tropical cyclone in world history. Satellite loops show that Haiyan weakened only slightly, if at all, in the two hours after JTWC’s advisory, so the super typhoon likely made landfall with winds near 195 mph. The next JTWC intensity estimate, for 00Z UTC November 8, about three hours after landfall, put the top winds at 185 mph. Averaging together these estimates gives a strength of 190 mph an hour after landfall. Thus, Haiyan had winds of 190 - 195 mph at landfall, making it the strongest tropical cyclone on record to make landfall in world history. The previous record was held by the Atlantic's Hurricane Camille of 1969, which made landfall in Mississippi with 190 mph winds.