The lowdown: What is a complex low pressure system?

We have a complex weather picture over the next few days, but what exactly does that mean?

Over the next few days we have a large, complex low pressure system overhead, affecting the UK and Ireland.

A complex low pressure system by definition, is when a system has multiple, interacting centres. Often there can be around three centres, though there can be several more.

The larger low pressure system spawns off some smaller lows, which can make predicting the weather even trickier than usual.

This is because the smaller-scale detail and specifics are very susceptible to change, with lots going on, so it can become quite a messy picture, with the forecast likely to become changeable.