Conclusions

The case study describes a typical summertime development, the western part of Europe may be under an extensive Upper Level Low or trough with unstable and cool weather, while an extensive area of high pressure is centered over Russia giving very warm and dry weather for eastern Europe. A baroclinic zone with considerable temperature gradient and instability may develop between these two air-masses.

In this case study the baroclinic zone extended from the Black Sea up to eastern parts of Scandinavia. A wave disturbance formed within the baroclinic zone. An asssociated low pressure centre moved northwards from the Black Sea. Warm and Cold Fronts brought precipitation, which was more continuous on the western (cooler) side of the Wave, and more convective on the eastern (warmer and more unstable) side of the Wave.

Warm Front cloudiness had a distinct band character, as the air in the warm sector was originally relatively dry. An appreciable amount of potential instability was released as a result of afternoon heating over western Russia, which resulted in very quick development of Cb cells and MCS's over an extensive area. The location of MCS's matched the location of maximum ThetaE at 850 hPa very closely. The mature MCS brought intense thunderstorms, gusty winds and rain to the Baltic States and to southern Finland later in the evening.