Daily Bulletin

The Conversation

  • Written by The Conversation
imageNowcasting is a system using satellite images to obtain real-time information before bad weather arrives. REUTERS/Mike Hutchings

Weather forecasters can save lives. Based on information from weather prediction models, an advisory warning can be sent a few days before a possible severe weather event such as heavy rainfall or strong winds. Closer to the time, further warnings are issued when forecasters have more certainty.

To do this, weather forecasters rely on nowcasting. This forecasting relies heavily on remote-sensing tools such as satellite or radar systems.

In countries where radar systems are available and well maintained the data gathered form a crucial part of real-time forecasting systems. But in developing countries radar systems are too expensive to obtain and maintain.

Real time warning

In many African countries, basic ground-based observation systems are not adequate to provide a real-time feed of the weather. This lack of data means that the public cannot be warned of severe weather events that could lead to loss of life and property.

But satellite data can provide very useful information in regions where there is no or limited access to expensive observation systems.

Numerical weather prediction data, together with geostationary satellite data, can help nowcasting. This is why the World Meteorological Organisation has thrown its weight behind providing nowcasting in countries where advanced observation data is unavailable. It has launched severe weather forecasting demonstration projects to improve nowcasting in data sparse regions around the world.

Blanket satellite coverage

The Meteosat Second Generation satellite was launched in 2002 by the European Space Agency and the European Organisation for the Exploitation of Meteorological Satellites.

This satellite provides full coverage of the African continent with a time resolution of 15 minutes. The numerous visible, infrared and water vapour channels, as well as colour (red-green-blue) combinations of these channels provide reliable data for nowcasting.

When the satellite was launched, an initiative to get experts in Europe to develop applications for various purposes using the 12 channels provided by the satellite also started. Eight satellite application facilities were established each with an area of focus. These include nowcasting and short range forecasting, climate monitoring, numerical weather prediction, and land surface analysis.

The Nowcasting Satellite Application facility uses data from the geostationary satellite to provide information on clouds related to significant convective systems. By tracking rapidly developing thunderstorms it is possible to identify, monitor and track intense convective system clouds and to detect rapidly developing convective cells.

Warnings saves lives

The rapidly developing thunderstorms software distinguishes different phases of the thunderstorm. It does this by using the different satellite channels to determine cloud depth, vertical extent, cloud top temperature, cooling rate and possible convective activity. Using the images of the past hour, it determines direction and speed of movement. This is then estimated for the next 30 minutes.

With knowledge of the phase of the storm and its intended direction, a forecaster can use the information to issue a weather warning.

A satellite based tool, such as the thunderstorms software, should be used with other data sources such as radar systems and surface observations where possible.

The identification and tracking of thunderstorms is a bigger challenge in data sparse regions than in areas in which expensive and extensive ground and remote observation networks exist. Warning the public about pending severe weather events is the mandate of all operational weather services. They have the power to save lives as well as protect property.

This article is based on an article published in the South African Journal of Science in July 2015.

Estelle de Coning receives funding from WRC and works for SA Weather Service.

Authors: The Conversation

Read more http://theconversation.com/how-satellites-are-helping-africa-improve-weather-forecasts-45548

Writers Wanted

No Barnaby, 2050 isn't far away. Next week's intergenerational report deals with 2061


Tips For Good SEO In The Law Sector


The Conversation


Prime Minister interview with Karl Stefanovic and Allison Langdon

Karl Stefanovic: PM, good morning to you. Do you have blood on your hands?   PRIME MINISTER: No, it's obviously absurd. What we're doing here is we've got a temporary pause in place because we'v...

Karl Stefanovic and Allison Langdon - avatar Karl Stefanovic and Allison Langdon

Prime Minister Scott Morrison delivered Keynote Address at AFR Business Summit

Well, thank you all for the opportunity to come and be with you here today. Can I also acknowledge the Gadigal people, the Eora Nation, the elders past and present and future. Can I also acknowled...

Scott Morrison - avatar Scott Morrison

Morrison Government commits record $9B to social security safety net

The Morrison Government is enhancing our social security safety net by increasing support for unemployed Australians while strengthening their obligations to search for work.   From March the ...

Scott Morrison - avatar Scott Morrison

Business News

Victorian businesses can claim a rebate on COVID-19 deep cleans until 30 June - but many remain unaware

With exposure sites on the rise and financial stresses already on most Victorian businesses, the recent Business Victoria announcement of a substantial 80% COVIDSafe Deep cleaning rebate is a time...

Article by Damien Smith, CEO of Prime Group - avatar Article by Damien Smith, CEO of Prime Group

Six Tips to Get your Business Known on Social Media

Social media is one of the most effective ways to market your brand to the masses. With the meteoric rise in popularity of various social media platforms over the past decade, millions of brands h...

NewsServices.com - avatar NewsServices.com

Boom in Aussies buying up restaurants, pubs, hotels and bars in regional centres

With international borders closed, regional Australia is seeing a dramatic surge in popularity as people move out of the cities and into their quaint communities. City slickers are looking for new...

Tess Sanders Lazarus - avatar Tess Sanders Lazarus