Model: GFS (Global Forecast System) Global Model from the "National Centers for Environmental Prediction" (NCEP)
Update: 4 times per day, from 3:30, 09:30, 15:30 und 21:30 GMT
Greenwich Mean Time: 12:00 GMT = 13:00 BST
Parameter: Vertical velocity at 700 hPa the British Isles in hPa/h
Description: The vertical movement of air is associated with cloud formation, precipitation, type of precipitation (positive velocity or rising air motion) or the reduction of clouds, dry an sunny weather (negative velocity or falling air motion). The vertical velocity is the result of vorticity advection and temperature advection.