Airmass RGB

Airmass RGB, 31 May 2013, 00 UTC - 23 UTC (Source: DWD)

The difference between the high cumulonimbus clouds in white and the lower clouds is easy to see. We can see the change and swirl of the different air masses. Greenish-red warm air moves north from the Black Sea while cold air moves south over France. There was a small area with dry descending stratospheric air in the center of the low in the afternoon, depicted in a reddish color over the Czech Republic.