"When we commit blunders, we look for culprits to bear the responsibility…

… climate change and even less, weather forecasting, cannot be the culprit”

Encounter

Suresh Boodhoo, former Director – Mauritius Meteorological Services

* Recent floodings: ‘Should we blame climate change for that?’

Suresh Boodhoo, former Director, Mauritius Meteorological Services, President, WMO Commission for Climatology (1997-2007), and Consultant on Climate Matters takes a critical look at the complex factors that go into making weather forecasts, with cyclone recent Freddy as the starting point of his analysis. Given the complexity of the exercise and the sophisticated armamentarium required for the purpose, he cautions against reliance on amateur lay forecasters. At the same time he points out that climate change cannot bear the brunt of responsibility for the many problems we see with flooding, etc., on the ground, and that planners and developers too must practise due diligence as regards building projects.

* You retired as director of the Mauritius Meteorological Services in 2010 after a 35-year career, but I presume you would still be keeping track of prevailing weather conditions in this part of the world and their impact on Mauritius. Is it possible to do so with weather/climate data available online – without the local Met services’ technology or the inputs made available to it by foreign partner agencies?

A meteorologist is always a meteorologist. But it is important to understand that a comprehensive analysis of the weather system involves the availability and analysis of data at grid points of one degree apart over a large horizontal expanse. And this exercise is not limited to the surface only but at different levels high up into the atmosphere.

One needs to understand the dynamics of the atmosphere in its three dimensions and its evolution with/over time. At each grid point indices are derived using complex equations of fluid dynamics. All these values are then analysed and a proper “meteorological image” is constituted.

As you may imagine, the human mind cannot process such equations nor imagine this image with accuracy. Powerful computers are essential to work out this massive bulk of data. Only some countries in the world dedicate such computers for the benefit of meteorology. The output is then disseminated to Members of the World Meteorological Organisation (WMO) under a well-defined protocol.

Although satellite imagery is more easily available, its analysis entails a good knowledge of cloud systems and their dynamics. There are numerous features which can be observed on satellite pictures, but we rarely come across them in our weather bulletins. One example of such a feature is a jet stream which can be depicted on satellite pictures but only to the alert eye. Jet streams, although situated at heights of 10km or more, do have their impact on weather pattern at ground level.

So, to answer your question I will only be able to make superfluous conclusions and not as detailed and specific as would the informed meteorologist.

* At this very moment (Sunday 19 Feb), there’s the threat posed by the very intense tropical cyclone Freddy, which according to the Met’s forecast is set to hit Mauritius Monday night. A cyclone warning class II is currently in force.Would you say it would be possible to make an accurate guess of how it will develop over the next 48 hours?

With data from world centres, it is easier to predict the movements of such cyclones. Besides one can see the predicted track that the cyclone is likely to follow with some minor adjustments now and then. But mind you, the judgement of an experienced meteorologist is still imperative.

Why are cyclones analysed to be stronger over the ocean than near or over landmasses? There is more energy in, and less friction over, the ocean waters. Although the computer model output takes such aspects into consideration, yet the meteorologists have to understand these and other assumptions. Hence the adjustments.

An exact prediction is always a challenge if the land is small where a 20-30 km error east or west may make all the difference. While such allowances are tolerable and considered unavoidable for larger landmasses, for Mauritius it’s either a 10/10 or a 0/10.

* There are also weather enthusiasts who somehow manage at times to make reliable forecasts based on online data. Does this mean we should pay heed to local citizen- or backyard-meteorologists, as they are known in other countries where they help ‘by taking real-time weather observations, alerting officials about severe weather occurring where (they) are, and contributing to research using an app on their phones’?

Weather enthusiasts may take up freely available output of large centres from their websites. But from here to the question of accuracy, one has to walk the extra mile.

You would recall in the past even major world weather centres had very mistakenly predicted that a dangerous tsunami was unfurling towards Mauritius. Fortunately, we had the necessary tools which enabled us to make our own conclusions and there was no tsunami as such.

Under the aegis of WMO there is a formal agreement among members that no one state will embarrass the other by forecasting weather on the latter’s behalf unless there are specific requests for same. So, with the advent of technology and the freedom of action, one cannot prevent amateurs from stepping onto the scene. For these latter, it is challenging to be able to excel as a weather forecaster.

Besides, amateurs want to shine in numerous fields. We must all have consulted or sought guidance from YouTube and other fora and must have come across the heaps of information and advices, often unauthenticated, in different fields. This is how even the more dangerous practice of auto-medication has arisen. This renders the practice of medical doctors complex. The same scenario exists in agriculture, mechanics, electronics, etc.

* Is it the view among Met professionals that ‘amateur’ weather forecasters, who are not accountable to any authority, may harm the public interest by creating a state of confusion given that their forecasts may not be based on scientific studies?

Very much so. But mind you, as far as the demand for such amateurism exists, the domain will thrive. If suppressed, the danger may come from beyond our shores.

Accountability yields professional output and response, not only in weather forecasting but in all other domains, whereas amateurism may jeopardise human lives.

* Thousands of Mauritians seem to believe that the local amateur weather forecasterAfzal Goodur’s forecasts are more dependable than the local Met Services’. How do you react to that?

I will refrain from judging others but in this particular case and with a smile I would suggest that amateurs who feel confident open their own business in this free country. This may give greater impetus to our competent bodies to improve if the need arises.I normally refrain from making forecasts for friends and relatives, always arguing that it’s the job of the Meteorological Services.

* The Mauritius Meteorological Services, which is manned by trained meteorologists, and properly equipped, has been criticized recently for some of its forecasts about imminent flood conditions which were not entirely accurate.What could have gone wrong?

Instruments do not lie. They will always provide accurate and reliable data. There have been instances, here and in advanced countries with powerful organisational skills and means, when untimely forecasts outputs have created havoc and even led to the loss of lives. If any wrongdoing is suspected, a proper mechanism should be set up by the authorities to investigate. Late decisions can be a result of red tape as was the case in at least one occasion when I was in office or due to unavailability of adequate information.

But it needs be underlined that information disseminated is often not taken seriously. Have we not, in the past, heard of hurricane parties or people stranded when they were advised not to venture out? During the passage of Freddy, people were out swimming, surfing or watching the phenomenal waves. We have witnessed lives lost and property damaged.In such complex cases the first move is to find faults with the forecast.

* Would you say that climate change, which is having a tremendous impact on weather conditions all over the world, is making it harder to make forecasting less accurate?

The principle and mechanism of atmospheric processes are the same with or without climate change. But the intensity and speed of processes are changing. And this is not always easy to assess.

I remember my old days, as president of the WMO Commission for Climatology, when after a lengthy discussion on the impact of climate change, a very learned colleague volunteered in the following words: “The probable impacts of climate change may be so vast and complex, that we should all go back to our university benches. But who is knowledgeable enough to teach us?”

But we should not always look for a scapegoat in climate change when we are unable to justify our erroneous actions. We often try to compare cyclones that have impacted us in the past. It should be understood that, as it is very rare to have two identical human beings among the 8 billion or so on earth, it is equally rare for two cyclones to be identical in structure or intensity of movement.

In the case of Freddy, we heard of wind speed in excess of 300km/hr near its centre while it was evolving over sea waters where friction is less than near land. Whether this assessment is due to changes in methods of analysis or can in reality be measured remains to be seen. But we should recall that Gervaise in 1975 provoked gusts of 286km/hr and this was measured. Was it then climate change? There are no systematic occurrences of such impacts that can be attributed to climate change only.Read More… Become a Subscriber

Mauritius Times ePaper Friday 24 February 2023