ManilaTC StormBasics: Effects of Tropical Cyclones over Land areas
Tropical Cyclones do damage to homes, buildings, infrastructures, and livelihoods with strong winds, disastrous flooding and landslides that comes along with the torrential rainfall, coastal flooding and erosion due to the storm surge.
Today we will deal with Wind Damage, the most looked at part in a storm.
Today we will deal with Wind Damage, the most looked at part in a storm.
Wind Damage
"I live on the 9th floor of a building: leaves were blown in by the winds. Flying GI sheets everywhere but mercifully, no shoddy construction in my neck of the woods. Areas with tall buildings create all sorts of funky wind tunnel effects so at particular moments, the different gusts led to raindrops being suspended in midair for moment"
Then I saw roofs flying again and I was scared it’s gonna chop my head off!
|
Strong winds can damage or destroy vehicles, buildings, bridges, and other outside objects, turning loose debris into deadly flying projectiles. Tropical cyclones often knock out power to tens or hundreds of thousands of people, preventing vital communication and hampering rescue efforts. Tropical cyclones often destroy key bridges, overpasses, and roads, complicating efforts to transport food, clean water, and medicine to the areas that need it. Furthermore, the damage caused by tropical cyclones to buildings and dwellings can result in economic damage to a region, and to a diaspora of the population of the region. The extent of damaging winds will vary between cyclones. More importantly, the most severe winds will be confined to a small area around the outside of the eye. Often people will experience the winds in the outer part of a Category 4 or 5. They will believe that they have experienced a major cyclone, yet the winds may have only been Cat 1 or 2 strength. It is important to recognise the structure of a cyclone when assessing past experience. This will make a future direct hit less of a surprise. |
Important Facts
What does Maximum Sustained Winds Mean?
The maximum sustained wind mentioned in the advisories that the PAGASA or JMA or JTWC (or any weather agency for that matter) issues for tropical storms and typhoons are the highest surface winds occurring within the circulation of the system. These "surface" winds are those observed (or, more often, estimated) to occur at the standard meteorological height of 10 m (33 ft) in an unobstructed exposure (i.e., not blocked by buildings or trees). Gusts are a few seconds (3-5 s) wind peak. Typically in a typhoon environment, the value of the maximum 3 second gust over a is on the order of 1.3 times (or 30% higher than) than the sustained wind. Typically gusts over open land will be about 40% greater than the mean wind and gusts over the ocean will be 25 - 30% greater than the mean wind. It is often the stronger gusts that cause the most significant damage to buildings While a storm advice may refer to a certain maximum sustained wind or gust, there will be localized points where the winds will exceed this value, particularly in gullies, about ridges and between buildings where winds can be funneled by the landscape. Note: PAGASA and JMA uses an average wind of 10 minutes sustained wind to provide TC intensity. The JTWC uses the United States standard of 1 minute sustained wind. This is the cause of the discrepancy in TC intensities between agencies. |
The Strongest winds in a Typhoon are in the RIGHT side of the storm.
First, the "right side of the storm" is defined with respect to the storm's motion: if the typhoon is moving to the west, the right side would be to the north of the storm; if the typhoon is moving to the north, the right side would be to the east of the storm, etc.
In general, the strongest winds in a hurricane are found on the right side of the storm because the motion of the hurricane also contributes to its swirling winds. Example: A typhoon packing 160kph is moving west at 20kph. Thus, it would have 180 kph winds on the right side and only 140 kph on the left. Note that forecasting center advisories already take this asymmetry into account and, in this case, would state that the highest winds were 180 kph. |
MTC would like to acknowledge the following sources:
Video courtesy of James Reynolds of Earth Uncut Productions
Wikipedia - Tropical Cyclone Portal
Sky-chaser.com by Chris Collura
The Weather Channel - Tropical Cyclone's Inland Dangers
Weather Underground
Chris Landsea, NOAA Hurricane FAQ
Bureau of Meteorology, Australian Government
Video courtesy of James Reynolds of Earth Uncut Productions
Wikipedia - Tropical Cyclone Portal
Sky-chaser.com by Chris Collura
The Weather Channel - Tropical Cyclone's Inland Dangers
Weather Underground
Chris Landsea, NOAA Hurricane FAQ
Bureau of Meteorology, Australian Government