Meteosat 8 IR 10.8 µm and Theta E 850 hPa

High ThetaE values are an indication for instability. The empirically retrieved threshold for severe weather at 850 hPa is the value 320.
A pronounced ThetaE maximum is found over Bulgaria and Greece. Its instability is reflected by bright/white colour in IR 10.8 satellite image showing frontal cloudiness and, even more obvious, a big convective cell at the leading edge of frontal zone. The second two ThetaE maxima can be observed over western and eastern Turkey.

A ThetaE ridge can be observed in front of the front with two maxima, indicating a preferable area for convective development. Also, a pronounced ThetaE maximum exists over the cold front.

The ThetaE maximum over eastern Turkey strengthens. This area is conditionally unstable and should be looked at in the following hours.

The ThetaE values in the frontal area fall under 320. As the result, level of convectivity weakens and the brightness in the IR 10.8 satellite image within the front attenuates. On the other hand, eastern Turkey is still potentially unstable.

Previously discussed unstable area over eastern Turkey with high values of ThetaE becomes brighter in the satellite image as new convective cells develop. The front reaches the highly unstable area and the convection intensifies resulting with an MCSs embedded in the frontal zone.

The cloud systems in the area of pronounced ThetaE maximum over middle and eastern Turkey are developing further.  

The values of ThetaE diminish, hence the atmosphere becomes less unstable and the convective development is weakening.

The situation is similar to the one 6 hours before.