Model: Global weather forecast model from the UK MetOffice
Update: 7:00 GMT und 19:00 GMT
Greenwich Mean Time: 12:00 GMT = 13:00 BST
Variable: Geopotential Height and Temperature at 500 hPa
Description: The maps show the predominant tropospheric waves (trough or ridge). They virtually control the "weather" (wet, cold / dry, warm) and the long waves drive the smaller synoptic waves. Thus, this upper-level chart illustrates the dynamics of our atmosphere.