Tag Archives: typhoon

In the path of a hurricane

Hurricanes are one of the planet’s most destructive natural weather phenomenons. With Hurricane Matthew currently making it’s way through the Caribbean, it’s important that communities adhere to local emergency services and action plans.

Hurricane Genesis

Hurricanes are very large storm whose birth originates in the tropical oceans. They rotate about a central axis commonly called ‘the eye’. The oceans are a massive source of heat energy. Variations in sea surface temperature result in pressure differences in the atmosphere which cause storms to build up.

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Tropical storms are characterised by their geographic origins. Image: NASA

To be classified as a hurricane a storm must reach wind speeds of at least 74 miles per hour. The rotation of the Earth gives these storm their characteristic spiral shape. Cyclonic storms in the northern hemisphere rotate anticlockwise while those in the southern hemisphere rotate clockwise.

Hazards

The main hazards from hurricanes are strong winds (up to 150 miles per hour for the very large storms) and high volumes of rain. Hurricane winds can uproot trees and destroy houses. Large amounts of rainfall in a short period of time can cause floods and rising groundwater tables.

The water-clogged landscape remains unstable, with increased risk of landslides and surface failures, for many years after a particularly large event. For example, there were increased number of landslides in Taiwan for 6 years after Cyclone Bhola.

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Extensive damage after the 2005 hurricane Katrina. Total damage > $100 billion USD. Image: Mark Wolfe

Historically significant hurricanes

The effect hurricanes have on people’s lives is illustrated by the word hurricane itself; after the Caribbean god of evil, Hurrican. They are a devastating force of nature.

  • Cyclone Bhola (1970) is historically the worst event for deaths with reported numbers as high as 500,000 people dead, mostly in Bangladesh.
  • Hurricane Katrina, which struck the east coast of the U.S. in 2005 is the most costliest hurricane with overall damage exceeding $100 billion.
  • The 1979 Cyclone Tip was the most intense hurricane ever recorded with wind speeds around 190 miles per hour. It was also the largest hurricane with a diameter around 2,170 kilometres.
  • Hurricane Sandy (U.S. east coast, 2010) was an abnormally large event due to the fusion of a tropical hurricane and a winter storm. With rising temperatures due to global warming these hybrid-storms are expected to become more frequent.

What can we do?

Cyclone Mahasen hit Sri Lanka, Bangladesh and Burma last season in May and resulted in far less deaths than expected thanks to swift action from the local governments. This shows that rapid response can save lives.

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Proper preparation and sufficient warning can save thousands of lives every year.

Houses with appropriate shelters (as in the U.S.) need to be built in hurricane prone regions. Proper training should be given from early school level onwards on the appropriate actions to take before and after such events: e.g. having enough clean drinking water, tinned food, spare batteries for lights, mobile phone chargers, first aid kits etc.

Have a rapid response system in place from the national governmental level to manage pre-event evacuation (if needed) and post disaster recovery.

There is no clear agreement on what sort of effects climate change and global warming will have on hurricanes. However most scientists agree that the change will be for the worse whether it is in the form of increased number of hurricanes each year, increased size of the hurricanes or changes to the length of the hurricane season .  We need to invest more into understanding the science behind these storms and the effects global warming will have on their magnitude and frequency of occurrence.

More information
[1] National Hurricane Centre
[2] George M. Dunnavan & John W. Dierks (1980). An Analysis of Super Typhoon Tip (October 1979), Joint Typhoon Warning Center,1980
[3] www.weather.com/maps/news/atlstorm18/gulfofmexicosatellite_large.html

Typhoon Soudelor rages across Western Pacific

Key News:

  • Typhoon Soudelor has been underdoing rapid growth and intensification during the last few days over the Western Pacific ocean.
  • Winds of 170 kph (105 mph) were reported on Saipan as the eye of the storm passed over the island late Sunday night.
  • The typhoon is currently heading west towards the southern tip of the large island nations Japan and Taiwan.
  • There are tens of smaller populous islands in the wake of the storm.
  • Soudelor will continue to strengthen while it crosses the northern Philippines Sea on its way towards eastern Asia.
  • This year’s record-breaking North Pacific typhoon season has been strongly influenced by the strengthening El-Nino conditions.
Projected trajectory of typhoon Soudelor. Source: AccuWeather.com
Projected trajectory of typhoon Soudelor. Source: AccuWeather.com

More information:
[1] http://www.ssd.noaa.gov/PS/TROP/storms/SOUDELOR.html
[2] http://www.accuweather.com/en/weather-news/tropical-storm-soudelor-to-thr/51154058
[3] http://www.weather.com/storms/typhoon/news/typhoon-soudelor-forecast-west-pacific-taiwan-japan
[4] http://www.rms.com/blog/2015/07/21/the-2015-northwest-pacific-typhoon-season-already-a-record-breaker