The weather is one of the great concerns of our day to day. If it’s sunny, no problem. But as soon as the rains, snow or fog come; problems also come. Therefore, looking at today’s or weekend’s weather when we have outdoor plans is essential. This is without counting the people who, due to their work – such as fishermen or farmers – need to know what the weather is going to be like every day. But, How are weather forecasts made? And why do predictions sometimes fail?
You don’t have to go far back to see problems related to weather forecasting. This same Holy Week, in many areas of Spain it has rained almost without warning. And, unfortunately, the weather this weekend is presented with rain and storms in a part of the Iberian Peninsula. Many people will be wishing the predictions were wrong, but that remains to be seen.
In addition, last January there was a historic snowfall in Madrid; Despite the warnings, neither the Community nor the City Council were prepared for what came upon them. This was not a failure by predictions, it was a human error: many people thought that it was not going to be such a big deal. Among the citizens it is normal not to give so much importance to the weather, after all they are not used to snow in the urban area of the capital. However, the experts warned. They gave the alarm to political leaders and also to citizens. Despite everything, the snow caught many people with their asses in the air.
This is how the weather works
But we have not come to talk about Madrid or human failures. Let’s talk about the science behind the predictions: the meteorology.
weather forecast based first on observation. That is, to know what the weather will be like, all the variables that we know lead to one time or another are controlled. For this we have the weather stationssatellites and other technology that allow us to measure humidity, wind, temperature, pressure, precipitation and other variables.
Then we need mathematical models and computers to analyze them. With the observation data, we can predict what the weather will be like in the next few days. “Weather forecasts are getting better and better: today, a five-day weather forecast is as reliable as a two-day forecast was twenty years ago,” he explains in his Web the World Meteorological Organization (WMO).
Weather and climate forecasting “produce much more than just weather forecasting,” says the WMO. Supercomputers “use mathematical models (numerical weather prediction models) based on the laws of physics to produce graphics, digital products, weather and air quality forecasts, climate forecasts; risk assessments and early warnings. Weather satellites broadcast this weather information in real time, several times a day.”
Failures in the forecasts
But does the weather fail? Sometimes yes. In fact, when the weather forecast is consulted, it is usually accompanied by a percentage. This percentage tells us how confident the experts are, with the data they handle, that the forecast is correct. Ultimately, this indicates probability that the weather phenomenon will occur. If the percentage is large, for example there is a 70 or 80% forecast of rain, this indicates that it is more likely to rain. But there is always the possibility that no water will fall from the sky. However, with more than a 50% chance of rain, it is always better to leave the house with an umbrella.
In fact, airplanes are also an important part of the study of time. We already talked in hypertextual of it during the lockdown. And it is that airplanes help make better weather forecastsespecially as far as the winds are concerned.
Beyond that sometimes the predictions can be wrong, especially when they exceed five days; these are usually quite accurate. Meteorology is not an exact science, but neither is it wrong forever. Only you have to take into account the odds of rain, wind or any other factor that can spoil the weather at the weekend picnic.
This is an updated version of an article previously published in Hipertextual.