Category Archives: Weather forecasting

How can a hurricane near the USA affect the weather in Europe?

By John Methven It may seem bizarre that processes occurring within clouds near the USA, involving tiny ice crystals and water droplets, can have an influence on high-impact weather events thousands of kilometres away in Europe, and our ability to predict them … Continue reading

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Where is the high probability?

By Peter Jan van Leeuwen To determine the uncertainty in weather and climate forecasts an ensemble of model runs is used, see Figure 1. Each model run represents a plausible scenario of what the atmosphere or the climate system will do, … Continue reading

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Why does it always rain on me?

By Helen Dacre Last Monday morning I got so wet on my cycle to work that I had to spend 10 minutes under the hand dryer in the toilets to stop myself looking like a drowned rat. Being the keen … Continue reading

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Predictions and errors

By Javier Amezcua Predicting is one of the most ambitious goals of science. It goes beyond describing and explaining, and it attempts to “tell the future”. The prediction process has the following basic steps: We have an estimate of the … Continue reading

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A Random Blog

By Peter Clark As a young scientist I was introduced to turbulent flow in the traditional way – we consider an ‘infinite ensemble of realisations’ of a random flow, and split each realisation into the average over the ensemble and … Continue reading

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Improving jet stream forecasts through observational experiment

By John Methven Weather systems developing over the North Atlantic and hitting Europe are intimately related to large-amplitude meanders of the jet stream, known as Rossby waves. Characteristic weather patterns grow in concert with the waves, and the jet stream … Continue reading

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What will the weather be like in 3 weeks time?

By Steve Woolnough This may seem like a silly question, and whilst weather forecasts can’t tell you if it will be raining at lunchtime three weeks from today, they may be able to tell you whether in 3 weeks it’s … Continue reading

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Disentangling forecast errors

By Oscar Martínez-Alvarado In a previous blog entry I discussed the factors contributing to errors in weather forecasts. These factors were sensitivity to initial conditions, incomplete knowledge of the atmosphere’s state and incomplete representation of the laws of physics governing the … Continue reading

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The hard task of understanding forecast errors

By Oscar Martínez-Alvarado For the past few months I have been thinking about differences between what the forecasts predict and what happens in reality and trying to understand how and why forecast errors develop. These questions might seem simple, but are … Continue reading

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I blame Spain and France!

By Ross Reynolds I was concerned to read this warning published recently in a national newspaper, partly because to roast me would require perhaps 200 °C for quite a few hours, but to boil the air (see lower down the … Continue reading

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