ManilaTC StormBasics: Basic Typhoon Facts
Bagyo? Typhoon? What is it?
__Typhoon is a western pacific region-specific name for a strong tropical cyclone.
Word Origins
The word typhoon, which is used today in the Northwest Pacific, may be derived from Hindi/Urdu, Persian and Arabic ţūfān (طوفان), which in turn originates from Greek Typhon (Τυφών), a monster from Greek mythology associated with storms.
The related Portuguese word tufão, used in Portuguese for typhoons, is also derived from Typhon.
The word is also similar to Chinese "taifeng" ("toifung" in Cantonese) (great winds), and also to the Japanese "taifu".
Bagyo is a Philippine local term for a "tropical cyclone".
The term bagyo, a Tagalog word meaning typhoon arose after a 1911 storm in the city of Baguio had a record rainfall of 46 inches within a 24-hour period.
But in any sense its a TROPICAL CYCLONE. Bringing us to its technical definition.
A tropical cyclone is the generic term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection (i.e. thunderstorm activity) and definite cyclonic surface wind circulation.
While tropical cyclones can produce extremely powerful winds and torrential rain, they are also able to produce high waves and damaging storm surge as well as spawning tornadoes. They develop over large bodies of warm water, and lose their strength if they move over land due to increased surface friction and loss of the warm ocean as an energy source. This is why coastal regions can receive significant damage from a tropical cyclone, while inland regions are relatively safe from receiving strong winds.
Heavy rains, however, can produce significant flooding inland, and storm surges can produce extensive coastal flooding up to 40 kilometres (25 mi) from the coastline. Although their effects on human populations can be devastating, tropical cyclones can relieve drought conditions. They also carry heat energy away from the tropics and transport it toward temperate latitudes, which makes them an important part of the global atmospheric circulation mechanism. As a result, tropical cyclones help to maintain equilibrium in the Earth's troposphere, and to maintain a relatively stable and warm temperature worldwide.
Word Origins
The word typhoon, which is used today in the Northwest Pacific, may be derived from Hindi/Urdu, Persian and Arabic ţūfān (طوفان), which in turn originates from Greek Typhon (Τυφών), a monster from Greek mythology associated with storms.
The related Portuguese word tufão, used in Portuguese for typhoons, is also derived from Typhon.
The word is also similar to Chinese "taifeng" ("toifung" in Cantonese) (great winds), and also to the Japanese "taifu".
Bagyo is a Philippine local term for a "tropical cyclone".
The term bagyo, a Tagalog word meaning typhoon arose after a 1911 storm in the city of Baguio had a record rainfall of 46 inches within a 24-hour period.
But in any sense its a TROPICAL CYCLONE. Bringing us to its technical definition.
A tropical cyclone is the generic term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection (i.e. thunderstorm activity) and definite cyclonic surface wind circulation.
While tropical cyclones can produce extremely powerful winds and torrential rain, they are also able to produce high waves and damaging storm surge as well as spawning tornadoes. They develop over large bodies of warm water, and lose their strength if they move over land due to increased surface friction and loss of the warm ocean as an energy source. This is why coastal regions can receive significant damage from a tropical cyclone, while inland regions are relatively safe from receiving strong winds.
Heavy rains, however, can produce significant flooding inland, and storm surges can produce extensive coastal flooding up to 40 kilometres (25 mi) from the coastline. Although their effects on human populations can be devastating, tropical cyclones can relieve drought conditions. They also carry heat energy away from the tropics and transport it toward temperate latitudes, which makes them an important part of the global atmospheric circulation mechanism. As a result, tropical cyclones help to maintain equilibrium in the Earth's troposphere, and to maintain a relatively stable and warm temperature worldwide.
Tropical Cyclone activity in the Philippines
The most active season, since 1945, for tropical cyclone strikes on the island archipelago was 1993 when nineteen tropical cyclones moved through the country. There was only one tropical cyclone which moved through the Philippines in 1958.
The most frequently impacted areas of the Philippines by tropical cyclones are Northern Luzon and Eastern Visayas. A ten year average of satellite determined precipitation showed that at least 30 percent of the annual rainfall in the northern Philippines could be traced to tropical cyclones, while the southern islands receive less than 10 percent of their annual rainfall from tropical cyclones.
But things are a changing. For the last three years including the 2013 season, 4 named storms have crossed the Southern Island of Mindanao including Tropical Storm Washi/Sendong of 2011 and Super Typhoon Bopha/Pablo of 2012, each killing at least 1000 people and causing Billions of Pesos in damage.
A 1972 study by meteorologists of the US Navy/JTWC has shown that in the Philippines, being an island archipelago, tends to affect typhoons differently and according to intensity. In general, typhoons tend to lose on average 33% of their strength after crossing. As the storm approaches, the track tends to dip to the south prior to landfall then have a more northern track until exit. More intense typhoons lose 45%-50%, while weaker ones lose just 10-15% and then return to initial intensity.
A recent 2011 study by Taiwanese meteorologists of typhoons crossing the Philippines in 2000-2010, show that the eyewall diameter of the typhoons tend to increase by 87% upon landfall in the Philippines, then at least half of the typhoons contracted upon exit into the South China Sea. Its a known fact that expanding eyewalls show a weakening storm, and typhoons usually perform an eyewall replacement cycle during a Philippine Crossing.
Sources:
NOAA AOML Hurricane Research Division FAQ
English version Wikipedia - Tropical Cyclones portal
Brand, S. and J. W. Blelloch, 1973: Changes in the characteristics of typhoons crossing the Philippines. J. Appl. Meteorol.,
KH Chou, CC Wu, and YWang, 2011: Eyewall Evolution of Typhoons Crossing the Philippines and Taiwan: An Observational Study
Image credits: Sky-Chaser.com of Chris Collura and NOAA OSEI.