The power of observation

Rupert Holmes explains why, despite the advances in forecasting, your own observations on the weather are still vitally important

- Rupert Holmes

Despite the improvements in weather forecasting over the past few decades, it can still be enormously beneficial to compare your own observations with predictions. Forecasting is pretty good at telling you what’s going to happen, but predicting the exact timing, or location of events can still be a challenge.

There are a couple of reasons for this – firstly forecasts often cover a huge geographical area, which means there’s little scope for detail. Secondly a weather feature may move a little faster or slower than predicted. Alternatively cloud cover might be slightly heavier than forecast, which prevents the sun from breaking through, or even creates a little light rain.

A further problem for forecasters is that it’s very difficult to pin down exactly what the wind strength will be – a small change in the location of weather systems may result in the gradient wind changing by up to two points on the Beaufort scale.

Our own observations are hard data, rather than predictions, that can help to fine-tune our understanding of the forecast and build a more accurate picture of the likely weather for our location.

For instance, if the sun doesn’t burn through a thin layer of cloud on a summer’s morning we know that we’re less likely to see thermal enhancement of the wind during the afternoon. Or if the wind is stronger than forecast in the morning, observing the sky and keeping tabs on changes in atmospheric pressure may be able to tell you whether a system is moving across sooner than predicted, or whether the low has become deeper and more intense than expected.

Observing frontal progress