People with Chronic Obstructive Pulmonary Disease (COPD) often have periods during the year when their symptoms become worse. These are often due to an infection and are called "exacerbations" by doctors. Exacerbations are more common in the winter and also seem to be related to particular types of weather. As well as forecasting the weather the UK Met Office has developed a system to try to predict when exacerbations are likely to occur. The main purpose of this research study is to find out whether the Met Office forecasting service can predict when exacerbations are more likely to occur and whether the advice given during the predicted higher risk periods leads to fewer patients having an exacerbation or if it reduces the impact of the exacerbation. The study will also assess if there is a link between viral or bacterial infection and breathing problems that occur during the study period. The study will also collect information about possible causes of the breathing problems and what happens to the person afterwards. The results of this study will help us learn more about breathing problems which may lead to new research studies that would aim to improve the care of people with COPD.