What is a blocking high?

We've been stuck in a pretty stagnant set-up thanks to high pressure, with this system overhead known as a blocking high. But what does that mean?

A blocking high is a persistent area of high pressure that can lead to stagnant weather conditions, often referred to as "anticyclonic gloom."

This phenomenon typically occurs when the high pressure becomes stationary, preventing the usual movement of weather systems.

As a blocking high establishes itself over the UK and Ireland, it can sometimes creates clear skies and dry weather in the short term, though for us currently we're seeing a lot of cloud trapped inside.

The stability of this system can lead to several days or even weeks of unchanging conditions as we have experienced.

The lack of wind associated with the high pressure means that any moisture in the air remains trapped near the surface, resulting in low cloud cover and persistent mist or fog, particularly in the mornings.

It can also exacerbate air quality issues, as pollution becomes trapped under the stable atmosphere. Poor conditions are expected across some parts of the UK on our app's Air Quality Index (AQI).