Are hurricane, typhoon and cyclones different?
Hurricanes, typhoons and cyclones are the same weather system called different names depending on what part of the world they develop. In the Atlantic Ocean and north Pacific Ocean tropical storms are referred to as Hurricanes, in the Indian Ocean and south Pacific Ocean they are Tropical Cyclones and in the northwest Pacific Ocean they are Typhoons.
Hazards associated with tropical cyclones
Heavy rainfall, strong and damaging winds, storm surge, large waves, lightning and even tornadoes are associated with tropical cyclones. Heavy rainfall can lead to cascading hazards such as floods and landslides. Further devastating floods can be caused by a storm surge, which is a rise in the sea level caused by strong winds and atmospheric pressure during a tropical cyclone.
What's with the name?
One of the many questions and comments I come across on social media is related to the name of cyclones, hurricanes or typhoons. So why name tropical storms and where do the names come from?
Naming tropical cyclones makes them easier to be identified and communicate warnings to the media and communities at risk. Not many of us would remember technical names and numbers if they were used to name tropical cyclones!
A rotating list of tropical cyclones is maintained by the World Meteorological Organization for each tropical cyclone basin. A storm name is retired if it is deadly and has caused fatalities and widespread destruction. One such name is Hurricane Katrina, a Category 5 hurricane which affected the Bahamas, Cuba, Eastern United States and Eastern Canada resulting in over 1,800 fatalities and widespread destruction in 2005.
The names for the southwest Indian Ocean including the east coast of Africa, contains three lists validated by the Tropical Cyclone Committee (TCC). During each cyclone season, the first tropical storm begins with the letter 'A' from the list. The only exception is when a tropical storm develops over the southeast Indian Ocean and moves to the southwest Indian Ocean.
Southwest Indian Ocean Tropical Cyclone Names (Source: World Meteorological Organization)
To find out more about more about tropical cyclone names including the list for other tropical storm basins, visit the World Meteorological Organization website.
Tropical Cyclone Classification
Each cyclone basin uses a different classification. The image below shows these classifications.
Tropical cyclone classifications (Source: World Meteorological Organization)
Tropical Cyclones in Tanzania
Tropical cyclones are rare in Tanzania. By now you have probably heard of the two significant cyclones to affect the country. The Lindi Cyclone resulted in 34 fatalities after it made landfall in Lindi on 15 April 1952 with estimated wind speeds of 117km/h (110mph) (Stephen M. Blumel, The Tanzania hurricane of 14-16 April 1952, National Weather Digest). This cyclone was equivalent to a Category 3 hurricane.
The Zanzibar Cyclone made landfall over Zanzibar on 14 April 1872. Both cyclones caused devastating impacts including damage or destruction of houses, hospitals, the harbour, boats, infrastructure including bridges, roads, electricity, telephone and telegraph services and agriculture crops and plantations (Hellen E. Msemo, Declan L. Finney and Samwel I. Mbuya, Weather – Month 9999, Vol. 99, No. 99, Forgotten accounts of tropical cyclones making landfall in Tanzania).
In April 2016 heavy rainfall from the remnants of Cyclone Fantala resulted in floods which caused 2 fatalities in Zanzibar and 12 fatalities in the Kilimanjaro and Arusha regions. In addition, 420 people were displaced and 3,330 houses were destroyed in Zanzibar. 13,933 people were displaced and 315 houses were destroyed in the Kilimanjaro and Arusha regions (Kai, K.H., Ngwali,
M.K. and Faki, M.M. (2021) Assessment of
the Impacts of Tropical Cyclone Fantala to
Tanzania Coastal Line: Case Study of Zanzibar. Atmospheric and Climate Sciences,
11, 245-266).
Cyclone Jobo
Tropical Cyclone Jobo formed on 21 April over the southwest Indian Ocean. The maximum sustained wind speed recorded was 111km/h (69mph) on 21 April, making it a Tropical Cyclone (weak Category 1 Hurricane on the Saffir-Simpson Scale). Jobo weakened over the next few days to become a Severe Tropical Storm (Tropical Storm on the Saffir-Simpson Scale).
It was forecast to make landfall over the east coast of Tanzania on 25 April with maximum sustained winds of 65km/h (40mph) and weaken further. The maximum storm surge height forecast for Tanzania was 0.2m. Heavy rainfall, strong winds and storm surges were expected to affect Aldaba (Seychelles), Comoros, Mayotte and Tanzania. In preparation, fisherman in Tanzania were warned to suspend fishing activities and warning advisories were issued by the Tanzania Meteorological Agency.
On 25 April Cyclone Jobo made landfall over at Pwani, Tanzania as a Tropical Disturbance (Tropical Depression on the Saffir-Simpson Scale) with sustained winds of 46km/h (29mph). It weakened further while moving inland and dissipated.
Fortunately, no fatalities or significant damage has been reported.
Cyclone Jobo Track Map on 22 April (Source: JTWC)
Satellite image of Cyclone Jobo on 22 April (Source: JTWC)
Cyclone Jobo Track Map (Source: JTWC)
Satellite image of Cyclone Jobo on 24 April (Source: JTWC)
Satellite image of Cyclone Jobo on 24 April (Source: JTWC)
Final Warning Track Map of Cyclone Jobo (Source: JTWC)
What you should do to prepare for future tropical cyclones?
Below are a few tips to help you prepare for tropical cyclones in the future:
- Tune into reliable and official weather warnings and advisories. Make sure you monitor and keep up to date with the latest information. Forecasts and situations can change.
- Follow advice from official government sources and experts in the field. Remember, at times like these, rumours can be dangerous!
- Be aware of your risk. Are you at risk from flooding, landslides, storm surge or destruction from high wind speeds?
- Create a personal disaster plan (where to go when asked to evacuate, family rendezvous point, essential and useful contacts, actions you will be required to take etc.).
- If you have a business, ensure you have a Business Continuity Plan (BCM).
- Know how to shut off utilities including gas, electricity and water. Remember only turn off utilities if it safe to do so.
- Create a grab bag containing essential items such as regular medication, spare clothes, toiletries, money and cards, keys, mobile phone chargers, a list of useful contacts, first aid kit, torch and batteries, essential documents (passports, property and insurance) and food for your pets. Don't forget a hard copy of your disaster plan!
- Be ready to evacuate. If you are asked to evacuate by officials, do not ignore their advice. Be aware of where the community evacuation centres are located.
- Charge your mobile phones beforehand.
- If you have generators, make sure it works and has enough fuel.
- Stock up on essential items such as food, water and fuel.
- Check on neighbours, particularly the vulnerable.
- Secure items which can become lethal debris during a cyclone.
- Take refuge in an interior room away from windows.
- If you do not feel safe, seek alternative shelter.
- Maintain visual observations of your surroundings to check for hazards such as flooding.
- If flooding has occurred and evacuation is not possible, stay in a high place with a means of an escape.
- Never walk in flood water, just 15cm of fast flowing can knock you off your feet!
- Flood water can also be contaminated, so try to avoid contact with it. Always wash your hands if you do come into contact with it.
- Never drive through flood water. It takes only 30cm of flood water to move a car and 60cm to sweep away most cars.
- Have you taken your pets and livestock welfare into consideration? Make sure you plan ahead to keep them safe.
- Do not put yourself and others at risk!
Final remarks
With increasing technology specifically social media, rumours during disasters are unfortunately unavoidable. It is extremely important to always follow advice from reliable sources such as the government and experts in the field.
In April 2019 Cyclone Kenneth made landfall in Mozambique causing widespread destruction. Kenneth was forecast to make landfall in southeast Tanzania prompting numerous people to evacuate their homes. Tanzania had a lucky escape as a result of the cyclone changing direction. It is unfortunate that rumours and misinformation were being spread over social media. I came across posts claiming 'Tanzanians are scared of a little wind which is why they are evacuating', 'the storm is over exaggerated or a hoax'.
It is extremely dangerous and potentially life threatening to underestimate the power of a cyclone. There are countless examples from around the world of the devastation and fatalities they are capable of causing. Spreading misinformation and mocking a population for making the right decision might cause them to become more reluctant to prepare for hazard in the future. It is important to remember that evacuation may cause inconvenience, but it saves lives!
With the potential impacts of climate change and increasing risk and vulnerability, a cyclone making landfall in Tanzania has a potential to cause fatalities and widespread destruction in coastal cities and towns such as Dar es Salaam.
Always be prepared for disasters!
Useful websites
If you have any questions, feel free to send me a message!
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