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

12.00 UTC - Satellite Overview

29 January 1998/08.24 UTC - NOAA CH5 image	29 January 1998/11.36 UTC - NOAA CH4 image
29 January 1998/12.00 UTC - Meteosat WV image

The evolution of the wave can be followed best with NOAA imagery (left and right images top). In the morning the wavy appearance is becoming clearer, and around noon the classical appearance of a Wave is evident. A structure which can be called a cloud head can be noticed over Sweden and Finland, centred around 65N/23E. The Meteosat water vapour image reveals a distinct higher WV cloud edge extending from 68N/10E - 65N/25E and a lower WV cloud bulge penetrating from below over Sweden and Finland around 66N/22E. A dry Dark Stripe extends from 72N/05E into northern Norway.