ThetaE 850 hPa.

19th June 2006: 00UTC
A second way of describing the stabilty of the atmosphere is by making use of Theta E fields at 850 hPa

Why is Theta-E field chosen at 850 hPa?

Answer

High Theta-E values are an indication for instability. A Theta-E ridge or tongue is often the burstpoint for convective activity.
A pronounced Theta-E maximum is found over Germany. Its instability is reflected in IR10.8 by some Cbs. Further south a secondary maximum gives indication of an unstable atmosphere over Switzerland.

19th June 2006: 03UTC
High values for ThetaE are found over most part of Central Europe. In Germany still some remnant CBs are observed. The cell is situated in a high ThetaE ridge.

19th June 2006: 06UTC
Over the Elzas in France also convection has started. The cells are marked by strong ThetaE ridge of 329K.

19th June 2006: 09UTC
Over the Elzas in France also convection has started. The cells are marked by strong ThetaE ridge of 329K.

20th June 2006: 12UTC
Early signs of convection are now observed over Germany and Austria. This onset is marked by high ThetaE values. Over Germany the cells are all situated in a ridge.

19th June 2006: 15UTC
Convection has started which is reflected by high ThetaE 850 values. Concentrating on Austria we see a large MCS over the Eastern Part. In the ThetaE 850 fields we can clearly see a ridge inidicative on how unstable the atmosphere is in this region.

19th June 2006: 18UTC
Not only the high values are striking but also the tight gradient that well reflects the ridges of the high ThetaE values.

19th June 2006: 21UTC
Not only the high values are striking but also the tight gradient that well reflects the ridges of the high ThetaE values.