In addition to measurements we also use personal observations to describe the weather. Such observations can be:

• Pictures
• Reports
• Blog posts
• Private weather station measurements

As measurements cover only a very small part of the world, any other way to obtain data and weather information is welcome and useful to validate and improve the meteoblue simulations.

User observations can be employed in the validation process of the model, and for the post-processing to verify if a given weather event actually occurred, and to compare data at a very local scale or for very localised phenomena (such as wind gusts, turbulences, thunderstorms, hail or tornados). This helps improve the description of reality and to validate the models, should systematic differences be occurring. Contrary to measurements, such user observations cannot be used as initial conditions for model runs, as they often are not systematic nor accurate enough and are only reported after the event.