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Dynamical causes of Echo Training in The Southern Swiss Alps

Dynamical causes of Echo Training in The Southern Swiss Alps. Austin Wardall ERAU. Maggia Valley Flash Floods. Major Hazard Related to Echo Training Convective cells repeatedly triggering at the same location and following the same storm track. Procedure.

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Dynamical causes of Echo Training in The Southern Swiss Alps

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  1. Dynamical causes of Echo Training in The Southern Swiss Alps Austin Wardall ERAU

  2. Maggia Valley Flash Floods • Major Hazard • Related to Echo Training • Convective cells repeatedly triggering at the same location and following the same storm track

  3. Procedure • Modeled four major echo training events using the WRF-EMS mesoscale atmospheric research and forecasting model • Investigated the four simulations for similar precipitation patterns to those observed by Swiss operational radar data • Proceeded with a graphical study of dynamical conditions supporting orographic convective triggering upwind from the Maggia River

  4. Precipitation Events (Panziera et al., 2014)

  5. Topographic Map of Northern Italy and Switzerland

  6. Modeled Precipitation Events 17-18 Aug. 2006 5-7 Sept. 2008 “Good” Simulations

  7. Modeled Precipitation Events 5-6 June 2009 25-26 Sept. 2012 “Bad” Simulations

  8. Dynamical Findings

  9. Lee Troughing and Cyclogenesis 950mb relative vorticity and streamlines with 1km reflectivity 5 Sept. 2008 1700Z 17 Aug. 2006 1900Z “Good” Simulations

  10. Lee Troughing and Cyclogenesis 950mb relative vorticity and streamlines with 1km reflectivity 26 Sept. 2012 1800Z 6 June 2009 0100Z “Bad” Simulations

  11. MSLP 17 Aug 2006 1900Z 7 Sept. 2008 0200Z “Good” Simulations

  12. MSLP 6 June 2009 1900Z 26 Sept. 2012 2100Z “Bad” Simulations

  13. Low-level Moist Jet 950mb dewpoint and streamlines with 1km reflectivity 7 Sept. 2008 0500Z 17 Aug. 2006 2200Z “Good” Simulations

  14. Low-level Moist Jet 950mb dewpoint and streamlines with 1km reflectivity 26 Sept. 2012 1800Z 6 June 2009 0800Z “Bad” Simulations

  15. Conclusions • The model more accurately simulates the location of convection when it captures lee troughing to the north of the Appennine Range • The lee troughing to the north of the Appennines may contribute to the formation of an easterly barrier jet along the southern slopes of the Alps • The convergence of this barrier jet with moist southerly low-level flow from the Mediterranean over the southeast-facing Alpine slopes seems to be the main trigger leading to flooding in the Maggia Valley

  16. Citations Panziera, L., C. N. James, and U. Germann. "Mesoscale organization and structure of orographic precipitation producing flash floods in the Lago Maggiore region." Quarterly Journal of the Royal Meteorological Society (2014).

  17. Acknowledgements • Dr. Curtis James, ERAU • Luca Panziera, University of Trento • Dr. Gary Yale, ERAU Space Grant

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