* Tropical storms are formed through a process called Tropical Storm Genesis
* For TSG to occur certain factors need to be met
* The ocean must be at the temperature of 26o or above for 50m depth from the surface this means areas within the trade wind belt, where warm winds heat up the surface, are more likely to experience the formation of tropical storms. Also the ocean temperatures are the highest at the start of autumn as they’ve been heated up for the duration of the summer meaning tropical storms are likely to occur around this time.
* They usually start between 5-20o north or south of the equator and travel in a westerly direction.
* After the pass onto land from the sea (landfall) they more towards the nearest poles, however away from the oceans they lose power due to the lack of a heat source and eventually become storms before being classified as depressions.
* Atlantic Hurricanes are generally formed in the gulf of Mexico as the enclosed area means it can be heated up quicker and looses less heat
* Tropical storms are first seen as Tropical Depression and then once they become stronger they become Tropical Storms they then go up the categories from 1 to 5.
* The name differs depending on where the storm formed. If it is formed in the Atlantic then it is a hurricane, if it is formed in the pacific it is called a Typhoon’s, if they’re formed in South East Asia they are cyclones and of the coast of Australia they are called Willy Willies.
Minimal: Unanchored mobile homes,
vegetation and signs.
Moderate: All mobile homes, roofs,
small crafts, flooding.
Extensive: Small buildings, low-lying
roads cut off.
Extreme: Roofs destroyed, trees down, roads cut off, mobile homes destroyed. Beach homes flooded.
More than 155
Catastrophic: Most buildings
destroyed. Vegetation destroyed. Major roads cut off. Homes flooded.
Greater than 18 feet
August 25th 2005
August 30th 2005
Maximum Wind Speed
Lowest Sea-Level Pressure
Maximum Size Reached
Hurricane Katrina passed over south Florida and north of Cuba into the Gulf o Mexico, it then made landfall going north on Louisiana. Most of these areas are very developed with high population density. New Orleans is an area which is under sea level.
Hurricane Katrina formed as a Tropical Depression 12 over the Bahamas on the 23rd of August 2005 from the remains of Tropical Depression 10. This was then upgraded to a Tropical Storm on the 25th. It only reached a hurricane status 2 hours before landfall on Florida. As it travelled across Florida it lost power and hurricane status but the warm waters of the Gulf of Mexico caused it to become much more prominent and regain hurricane status within an hour. In a period of 9 hours it then reached category 5 status.
On the 27th the storm almost doubled in size and on the 28th reached its maximum recorded strength of 175mph winds. It was then that Katrina also became the fourth strongest Atlantic hurricane on record and was the strongest hurricane experienced in the Gulf of Mexico.
On the 29th it made landfall on Louisiana with wind speeds at 125mph. It then started to move north east over America. It wasn’t until 150 miles inland that it lost hurricane status but the tropical depression continued to cause problems as far as eastern Canada.
The impact of hurricane Katrina affected most of America, the main states it affected were; South Florida where it made landfall on the 25th, Louisiana where it made landfall on the 29th , New Orleans was the most affected area and there was also some problems caused in Mississippi and Canada. The strength of the hurricane reduced throughout this time so there was generally less damage in the places it reached later on. $81.2 billion of damage was done in total with 1836 deaths, and still today some debris remains in some coastal areas.
* 35cm rainfall and waves reaching 1.5m caused flooding
* Electricity was cut off leaving 1,000,000 people powerless
* $1-2 billion dollars of damage caused by falling trees and high water levels.
* 14 deaths
* To the south of Florida Cuba was flooded and electricity and phones were cut off causing the evacuation of 9000 people and an estimated 90% of Surgidero de Batabano, a coastal city, being submerged.
* Wind speeds of 125mph caused surges of up to 4.3m an average 25cm rainfall with the highest recorded being 38cm, this lead to the flooding of Venice
* Lake levels rose causing flooding and the risen river levels caused bridges to break
* Around 900000 people lost electricity
* At St. Tammany Parish surges reached 4.9m not including waves, 70% of the housing was damaged
* St. Bernard Parish was flooded after its levees broke and 81% of the houses were damaged
* 1577 people were killed in Louisiana in total
* With New Orleans being based under sea level the 53 breaches of the levees, with almost every levee area experiencing at least 1 breach, caused 80% of the city to become flooded.
* What made things worse was the disruption of roads meaning help could not be sent into the city and some roads being shut down to carry just emergency vehicles
* The Hyatt hotel was probably the worst affected building with almost every window being smashed and furniture coming out of windows. The same sort of things happened to other buildings as well especially windows being blown out.
* The Superdome was used to shelter people from the storm however the roof was broken and there was no order to the inside and high tension caused violence. 6 deaths were reported here 2 from possible suicide.
* 700 people were found dead most of which were found floating in the flood water.
* As Hurricane Katrina subsided it caused 62 tornadoes to form
* There was little damage here and it was caused mostly by falling trees
October 4th 1979
October 19th 1979
Maximum Wind Speed
Lowest Sea-Level Pressure
870mbar world record
Maximum Size Reached
2,220km world record
The main area affected was Japan which relied mainly on fishing and agriculture for its economy. At the time the country was relatively wealthy. However other areas affected were small islands to the south of Japan including, Guam and Chuuk.
The origin of Typhoon Tip was when three circulations formed in the monsoon trough between the Philippines and the Marshall islands. To the southwest of Guam, an island in the southwest of the Pacific, on October 3rd one of these circulations formed into Typhoon Roger. On the same day, south on Pohnpei, another circulation formed into a depression. Typhoon Roger moved west-wards and caused the depression to move erratically to the south-east of Chuuk a state in the FSM. On October 5th the depression prompted a warning from the Joint Typhoon warning center and it was named Tropical Depression 23.
During a cyclonic loop of Chuuk the depression turned into Tropical storm Tip however is was still not at its full potential due to Typhoon Roger creating conflicting air currents. On October 8th Tropical storm Tip steadied and started to move northwest. Around the same time Typhoon Roger was now an extra tropical cyclone and moved south to join Typhoon Tip. Also at the same time an outflow channel was formed to the north of Tip.
The storm was predicted to move northwest however on the 9th it started moving west and this prolonged period over the sea let it strengthen and later that day it was upgraded to Typhoon status. On October 11th it was regarded as a Super Typhoon and reached the world record for largest tropical storm. It continued to intensify and by the 12th the pressure was a record low of 870mbar. On this day it reached its peak strength and the eye of the storm was 15km wide. It then weakened to 145 mph and maintained this speed for several days moving North West. It wasn’t until the 17th that the storm began to weaken drastically and its size reduced. By the 19th when it made landfall on Honshu winds were 80mph and moved through the country forming into an extratropical cyclone. This depression was last seen near Alaska where it finally dispersed.
The first major impact of Typhoon Tip was the heavy rainfall of 23.1cm on Guam. Causing some flooding of the air base.
This major rain also caused a retaining wall to be breached at a United States Marine Corps on the south of Japan. This meant that marines then had to take shelter in huts at the base of a hill. The water led to two fuel pipes becoming dislodged causing a large amount of fuel to spill. The fuel storage was at the top of the hill and the fuel spill flowed down the hill to the huts in which the marines were sheltering. The heating apparatus for one of the huts caused the fuel to ignite causing a fire to spread over the area. This led to the death of 13 marines and 68 injuries. The fire also caused moderate damage to the area with the barracks and 15 huts being completely destroyed. The strong weather also meant fire fighters could not arrive until 2 hours after the fire had started. However there was no long lasting damage and the barracks were rebuilt in short time.
During the crossing of Japan winds were at about 44mph with the strongest blows reaching 69mph. As this sort of wind speed had not been seen in Japan before they were not well equipped to deal with it. The high wind speeds therefore caused large amounts of damage to the area. Millions of dollars of damage was done to the industry which revolved mainly around fishing and agriculture. A large amount of the fishing damage was due to ships being destroyed, eight ships were destroyed killing 44 men and a freight ship broke in half.
The main damage caused however was by the rainfall. Across the entire country 600 separate mudslides were caused and flooding resulted in 22000 homes being destroyed. 42 people were killed by the slides, 283 injured and 71 missing. Flood management was also destroyed with river banks breaking in 70 places.
After the storm 11000 people were left homeless and for a period after it trains and planes could not travel.
Hurricane Katrina Vs Typhoon Tip
Both the tropical storms caused deaths and both were category 5 at some point in their life but the extent of the damage done varied drastically as did the size. The large difference in size however did not necessarily affect the amount of damage. Typhoon Tip was 1410km bigger than Hurricane Katrina yet Tip only caused 86 deaths which is tiny in comparison to Katrina’s 1836. Some of the deaths in Japan were not 100% due to the Typhoon either the Marine Corps incidence could of happened at any time the fuel had become unattached.
The extent of the damage was also much greater in America compared to Japan. In Japan there were $millions of damage compared to America’s billions. Many more homes were destroyed in America meaning many more people were displaced. This could be the result of a higher population density in America however looking at the stats Louisiana has roughly 104 people per square mile and Japan had 122 people per square mile at the time meaning Japan had higher density. This would suggest that Japan was a lot better coped for the storms or that they have better placed cities, which aren’t in giant craters.
One aspect which may of lead to the problems in America was the large amount of flooding; Japan had much less problems with flooding which may be because of the mountainous areas. Japan had also had a very dry season before so a lot of the water would just move straight into ground storage. The flooding spread much quicker in America due to areas being below sea level meaning they would fill much more naturally and not just experience water flowing through the area. The mountains in Japan also meant mud slides were a much larger problem.
The strength of Tip when it reached Japan was much weaker than Katrina. Wind speeds were only at 80mph at landfall compared to Katrina at 125mph. This meant the storm was much weaker. Japan was also exposed to the storm for a much shorter time with the storm passing over Japan within a day and out to sea meaning the tropical depression would have no more affect on the country. Hurricane Katrina was at hurricane status for almost 2 days after landfall and it also weakened on land causing ore problems as it headed north.