How typhoons are formed
1. Typhoons start off as tropical thunderstorms. The strong winds pull in moisture from the oceans.
2. The thunderstorms convert the moisture into heat. The heat causes more air to flow to the centre of the storm causing evaporation.
3. All the heat and air flow toward the eye creating the typhoon.
Typhoon Haiyan's path and speed
The following map shows the typhoon's path through the Philippines and into China.
Typhoon Haiyan reached wind speeds of 314 km/h at landfall and gusts up to 378 km/h, stronger than hurricane Camille, the next strongest tropical cyclone, that had winds of 306 km/h.
The numbers correspond to:
1. Tuesday, 6 a.m.
2. Monday, 6 p.m.
3. Monday, 6 a.m.
4. Sunday, 6 p.m.
*Current as of Nov. 10 at 6 p.m. ET
Sources: Washington Post; NOAA; Central Weather Bureau; wiki.answers.com