<Li> TCWS #2 - Tropical cyclone winds of 61 km / h (38 mph) to 120 km / h (75 mph) are expected within the next 24 hours . </Li> <Li> TCWS #3 - Tropical cyclone winds of 121 km / h (75 mph) to 170 km / h (110 mph) are expected within the next 18 hours . </Li> <Li> TCWS #4 - Tropical cyclone winds of 171 km / h (106 mph) to 220 km / h (140 mph) are expected within 12 hours . </Li> <Li> TCWS #5 - Tropical cyclone winds greater than 220 km / h (140 mph) are expected within 12 hours . </Li>

Where do most of the typhoons that affect the philippines come from