european storm forecast experiment a close look at a severe mcs during the kyrill winter storm over...
TRANSCRIPT
European Storm Forecast Experiment
A close look at a severe MCS during the „Kyrill“ winter storm over Central Europe
Christoph Gatzen, Pieter Groenemeijer, Oscar van der Velde,
Jan Hoffmann, Angel Dimitrov, Helge Tuschy, Johannes Dahl
European Storm Forecast Experiment
• Ingredients-based theory
18 Jan
12 Z..
15 Z..
18 Z
European Storm Forecast Experiment
• Ingredients-based theory
18 Jan
12 Z..
15 Z..
18 Z
?
European Storm Forecast Experiment
• Estofex discussion: Ahead of the cold front…• Instability
• Neutral/slightly moist-unstable lapse rates and rich low-level moisture• At least minimal, but positive CAPE, even at low levels
• Forcing• Strong QG forcing, low-level convergence, initiation along cold front
• Shear• Strong vertical wind shear, favorable veering (SRH 0-1km ~800 J/kg)
• Expected Scenarios
1. Weak instability: Strongly-forced convective line along the cold front moving eastward. High winds the main threat, tornadoes possible
1. Significant CAPE: Well-developed MCS, cold pool and associated low level jets. Extremely high wind gusts at the leading gust front, tornadoes possible
European Storm Forecast Experiment
• Estofex discussion: Ahead of the cold front…• Instability
• Neutral/slightly moist-unstable lapse rates and rich low-level moisture• At least minimal, but positive CAPE, even at low levels
• Forcing• Strong QG forcing, low-level convergence
• Shear• Strong vertical wind shear, favorable veering (SRH 0-1km ~800 J/kg)
• Expected Scenarios
1. Weak instability: Strongly-forced convective line along the cold front moving eastward. High winds the main threat, tornadoes possible
1. Significant CAPE: Well-developed MCS, cold pool and associated low level jets. Extremely high wind gusts at the leading gust front, tornadoes possible
European Storm Forecast Experiment
• The Kyrill Storm: Satellite view
Hourly images:
18 Jan
08 Z..
19 Jan
00 Z
MSG
WV6.2-WV7.3 IR9.7-IR10.8
WV6.2i
copyright 2007 EUMETSAT
European Storm Forecast Experiment
• Associated MCS: Lightning
copyright 2007 EUMETSAT © DWD/Siemens AG 2007
15, 16, 17, 19 Z
European Storm Forecast Experiment
• Associated MCS: Radar composit
copyright 2007 EUMETSAT © DWD 2007
12 - 20 Z, radar ¼-hourly
European Storm Forecast Experiment
• Associated MCS: Radar composit
copyright 2007 EUMETSAT © DWD 2007
18 Z
European Storm Forecast Experiment
• Associated MCS: Cold pool evolution
LMK, surface observations © DWD 2007
16 - 20 Z
European Storm Forecast Experiment
• How did instability develop?
European Storm Forecast Experiment
• High low-level winds ahead of the front
LMK – Analysis 800 hPa winds at 18 Z WindprofilerBayreuth, 14-23 Z
European Storm Forecast Experiment
• Tornado occurrence over Germany
Berlin
Dresden
Tornados occurred at the eastern flank of the cold pool, where low-level winds likely shifted towards the south
• strengthen of low-level veering
• increase of low-level convergence
• also increase of instability due to cool westerly flow
overspreading the warm air mass as LMK suggests
European Storm Forecast Experiment
• Doppler radar observations: Dresden
European Storm Forecast Experiment
• Vertical cross section
European Storm Forecast Experiment
• The tornadic supercell near Lauchhammer
WER
European Storm Forecast Experiment
• The tornadic supercell near Lauchhammer
European Storm Forecast Experiment
• The tornadic supercell near Lauchhammer
European Storm Forecast Experiment
• The tornadic supercell near Lauchhammer
European Storm Forecast Experiment
• Thanks!
copyright 2007 EUMETSAT © DWD 2007
12 - 20 Z, radar ¼-hourly