Super-typhoon Haiyan, equivalent to a Category 5 hurricane on the U.S. Saffir-Simpson scale, struck the central Philippines municipality of Guiuan at the southern tip of the province of Eastern Samar early Friday morning at 20:45 UTC (4:45 am local time). NASA's TRMM satellite captured visible, microwave and infrared data on the storm.
Pela primeira vez, furacões de categoria quatro na escala Saffir-Simpson, isto é, com ventos entre 210 e 249 km/h, são flagrados ao mesmo tempo no oceano Pacífico, em imagem feita por satélite em 31 de agosto.
The Saffir-Simpson Hurricane Scale (SSHS) classifies hurricanes — Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms — into five categories distinguished by the intensities of their sustained winds. To be classified as a hurricane, a tropical cyclone must have maximum sustained winds of at least 74 mph (119 km/h). The highest classification in the scale, Category 5, is reserved for storms with winds exceeding 156 mph (251 km/h).