Case Study: 29 - 30 January 1998

• I. Introduction and Short Description of the Case
• Introduction
• The situation over the Arctic Sea before the development
• II. Analysis for 29 January 1998 06.00 UTC - Early Wave Stage
• 06.00 UTC - Satellite Overview
• 06.00 UTC - Frontal, Wave and Jet Streak diagnosis
• 06.00 UTC - Cross sections
• III. Analysis for 29 January 1998 12.00 UTC - Developing Wave Stage
• 12.00 UTC - Satellite Overview
• 12.00 UTC - Frontal and Wave diagnosis
• 12.00 UTC - Cross sections
• IV. Analysis for 29 January 1998 18.00 UTC - 30 January 1998 06.00 UTC - Rapid Development
• Rapid Development - Introduction
• Rapid Development - Satellite Overview
• Diagnosis of surface and Upper Level Lows
• Diagnosis of frontal parameters
• PVA and jet streak diagnosis
• Rapid Development - Cross sections
• Diagnosis of precipitation patterns with help of relative streams and NORDRAD radar
• V. Overview of Period 30 January 06.00 UTC - 18.00 UTC - Further Development of the Occlusion and ECMWF - HIRLAM Model Comparison
• Further development of the Occlusion
• Additional invesstigation: Comparison of HIRLAM fields vs. ECMWF fields of isotachs and PVA at 300 hPa

06.00 UTC - Satellite Overview

29 January 1998/06.00 UTC - Meteosat IR image; SatRep overlay: names of conceptual models	29 January 1998/06.24 UTC - NOAA CH4 image

An overview of the satellite features together with the SatRep conceptual models show two Baroclinic Boundaries. The south-western one extends from Iceland to south Norway, while the north-eastern one is located over north Norway and Sweden. A possible development area over 71N/18E is not mentioned here. The NOAA image of the same time reveals much more details, especially of the northern cloud system. The notable cloud streets generated by the outbreak of arctic air over the open sea are clearly seen. The north-eastern cloud system is beginning to have a Wave - like appearance; this essential development is impossible to see if only data from a geostationary satellite are used.