Frontal System across Europe with Wave Development - Case Study 12 - 13 November 1997

• I. Synoptic Situation for 12 November 06.00 UTC
• Overview and frontal diagnosis
• Wave development in the area Sardinia - Corsica
• Intensification of frontal cloudiness and activity by jet streak crossing
• Cloudiness over Italy and the Balkan peninsula in front of the Cold Front: Relative Streams
• II. Development During the next 12 Hours
• Frontal displacement with help of the Thermal Front Parameter
• Displacement of the Wave
• Front Intensification by Jet Crossing
• III. Synoptic Situation for 12 November 12.00 UTC
• Overview and new aspects
• Diagnosis of front and Wave(s)
• Relative streams: Cloudiness over the Balkan peninsula
• IV. Synoptic Situation for 12 November 18.00 UTC
• Comparison of cloud configurations between 12.00 and 18.00 UTC
• Overall situation and frontal diagnosis
• Relative streams
• V. Synoptic Situation for 13 November 00.00 UTC
• Introduction for 13 November 00.00 UTC
• Overview and frontal situation
• Relative streams: Frontal and pre-frontal situation
• VI. Development of Thunderstorms and MCSs During the Whole Period
• Introduction for the diagnosis of conceptual modles for convective developments
• The period 12 November 05.00 - 07.00 UTC
• The period 12 November 11.00 - 12.00 UTC
• The period 12 November 14.00 - 18.30 UTC
• The period 12 November 21.00 UTC - 13 November 00.00 UTC
• Some summarizing ideas

Introduction for 13 November 00.00 UTC

13 November 1997/00.00 UTC - Meteosat IR image	13 November 1997/00.00 UTC - Meteosat IR image

The IR and WV images from 13 November 00.00 UTC (left and right image) show somewhat changed features:

• The former Wave area and spiral structure has moved to north Germany and will no longer be discussed here;
• The Cold Front cloud band extends from Tunisia across Italy, Slovenia and Croatia northward to Hungary and Poland; there are a lot of substructures mentioned below;
• The intensification area released through jetstreak crossing is still recognisable between Tunisia, Sicily and Sardinia. It develops more and more a spiral structure; there is intensive Cb and MCS development at the leading side of the frontal cloud band from Sardinia northward to Croatia which will be discussed in a separate chapter together with the synoptic environment (compare Development of Thunderstorms and MCSs During the Whole Period);
• A fibrous cloud band with cyclonic curvature extending from Tunisia and Syria northward to south Italy has further developed since 18.00 UTC when it was first recognized; there is a very dry area between the two cloud bands there;
• With the eastward approach of the Cold Front cloud band the cloudiness over the Balkan Peninsula becomes less pronounced.