💧 Revolutionizing Brazil’s weather forecasts

There is a common perception in Brazil, particularly in the country’s more populous Southeast, that weather forecasting available to the public is frequently imprecise or wildly incorrect — more so than in other parts of the world.

A dry forecast can sometimes be debunked by heavy rain, while alert systems are frequently ridiculed for warning of incoming hailstorms minutes after they have already started. In its most severe cases, forecasts have failed to capture the intensity of extreme weather events that have claimed lives and homes.

While forecasts will never be 100% precise — and weather in large parts of Brazil is naturally harder to predict — there is some backing to the common-sense perception that the country’s weather reports are not up to scratch.

News reports from last May showed that 88.1% of the 564 automatic weather stations dotted around Brazil are more than 10 years old and have a failure rate of over 20%, effectively meaning they do not capture any data for one hour out of every five.

And it’s not just the frontline equipment that is aging. For the last 15 years, the heart of Brazil’s weather forecasting has been the supercomputer Tupã, named after the Tupi-Guarani god of thunder and maintained by the National Institute of Space Research (INPE), a federal agency linked to the Science and Technology Ministry.

Purchased for USD 23 million in 2010 and regarded at the time to be one of the most powerful machines of its kind, Tupã had an expected lifespan of six years — but it was kept in use for nearly 16. In 2021, INPE warned that a lack of investment in maintenance could cause Tupã to stop operations completely, which would have led to a Brazil-wide meteorological blackout.

In its technologically obsolete state, Tupã permits forecasts with a range of 20 kilometers — potentially yielding a single result for an area the size of São Paulo, a city big enough for its eastern reaches to be hit with severe floods while its western zone remains bone dry.

But there is also a meteorological explanation for the difficulties in Brazil’s weather forecasting, particularly regarding the country’s tropical regions in the Center-West and Southeast…

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