Upper Air Analyses for Europe from 12UTC data ... The available levels are as follows: 925 mb, 850 mb, 700 mb, 500 mb, 300 mb, and 250 mb. These are pressure levels, which equate to height above mean sea level as follows: 925mb = 800m; 850mb = 1,500m; 700mb =3,000m; 500mb = 5,000m; 300mb = 9,000m; and 250mb = 10,000m. The first three levels (925, 850 and 700) are representative of the lower troposphere; 500mb is in the middle troposphere and important because upper air features at 500mb drive the development of storm systems in the lower troposphere through vorticity and vorticity advection; 300mb and 250mb are at the base of the upper troposphere, where the jetstream is found. The only 300mb product I produce is divergence, which refers to positive mass divergence when the winds at this level 'spread out'. Negative divergence occurs when winds converge. Positive 300mb divergence is typically associated with general precipitation areas IF the lower troposphere is moist. Please note: I have expanded the map view and the maps now cover from southernmost Greenland to the northern countries of Africa.
(Click on any image below to enlarge)

925mb (left to right): Temperature (deg C), Height (30 m) & Isotach analysis

850mb (left to right): Temperature (deg C), Dewpoint (deg C), Height (30m) & Isotach analysis

700mb (left to right): Temperature (deg C), Dewpoint (deg C), Height analysis (30 m) & Isotach analysis


500mb (left to right)Relative humidity, Temperature (deg C), Absolute Vorticity, D) Height & Isotach analysis

Other products: (left to right) 1) 1000-500mb Thickness; 2) 300mb divergence analysis1; 3) 250mb isotach analysis
1 Note: Negative divergence = convergence.

This page was updated on August 24, 2018.