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
17 Aug Z
5 Sept Z
“Good” Simulations

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

11. MSLP
17 Aug Z
7 Sept Z
“Good” Simulations

12. MSLP
6 June Z
26 Sept Z
“Bad” Simulations

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

14. 950mb dewpoint and streamlines with 1km reflectivity
Low-level Moist Jet
950mb dewpoint and streamlines with 1km reflectivity
6 June Z
26 Sept Z
“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