Below are Synoptic pressure charts for the UK and Europe.

These Charts plot the air pressure at sea level, and also show fronts. The lines are called Isobars and join places of equal pressure. The closer the isobars the stronger the wind is.
Areas of high pressure have lower numbers around them, and areas of low pressure have higher numbers around them.

  High pressure systems normally bring settled and fair weather.
Low pressure systems normally bring cloud, wind and rain.

The are three main types of weather front:
Warm Fronts - These are shown as a red line with semi-circles pointing towards the colder air and in the direction of movement. Warmer air is moving in. Rain usually falls along the line of the front.
Cold Fronts - These are shown as a blue line with triangles pointing towards the warmer air and in the direction of movement. Colder air is moving in. Usually a band of rain will form, often followed by showers.
Occluded front - These are shown as a line both red semicircles and blue triangles or purple on some charts. These bring changeable weather conditions.

Latest UK Synoptic chart