Weather Charts

Surface pressure chart - UK Met. Office: Bracknell

Synoptic or Pressure Charts

The pressure chart shows the distribution of atmospheric pressure. Pressure systems - depressions (LOW pressure regions) and anticyclones (HIGH pressure) are marked and Isobars are drawn on the chart to link areas with the same pressure. Isobar lines are drawn at 4mB interval (4 HPa) and weather frontal systems are marked using standard symbols.

Cold front

Warm front

Occluded front

Wind direction and some indication of strength can be deduced from the pressure chart. In the Northern Hemisphere, winds blow in an anti-clockwise direction around a depression (LOW) and in a clockwise direction around an anticyclone (HIGH). The closer the isobars are together, then the greater the pressure gradient and the higher will be the wind strength.

Pressure charts are a useful help in interpreting satellite images. The satellite image shows the pattern of cloud cover and with the help of the pressure chart, frontal systems can be identified and tracked over a period of time. Typically, rain will be associated with the passage of a front - identifying and tracking the fronts can allow the forecast of rain, changes of temperature, wind direction and speed etc.

Surface pressure charts from the UK Met. Office.
	Charts are updated daily services) and show isobars, pressure systems, frontal systems etc. These charts are based on observations and show current weather conditions. Current surface pressure chart Forecast surface pressure chart: T + 24 hr Forecast surface pressure chart: T + 36 hr Forecast surface pressure chart: T + 48 hr Forecast surface pressure chart: T + 60 hr Forecast surface pressure chart: T + 72 hr Forecast surface pressure chart: T + 96 hr Forecast surface pressure chart: T + 120 hr
Visible light satellite image - UK Met. Office
	Download latest visible light images Download latest infra red band light images Latest sequence of images from the Met. Office in Visible light and Infra-Red - animated sequences available. Satellite images - main images page
(Surface pressure and satellite image shown for the same day - June 12th 1997)

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