Moist processes involved in IOP13 and IOP16. Fanny DUFFOURG Olivier NUISSIER Christine LAC CNRM-GAME / Météo-France & CNRS HyMeX ST-WV meeting, Toulouse, France, 15 May 2014

2/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May Objectives and methodology Two objectives:  Understanding the moist processes involved in the triggering and organisation of the precipitating systems and their interactions with the ambient flow.  Evaluation of their representation in the numerical simulations. Analysis of the precipitating systems observed during HyMeX SOP1 IOPs 13 and 16:  Numerical simulations with Meso-NH  Identification of the moist processes  Validation of the simulation and the processes identified against the extended HyMeX observational dataset

3/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May IOPs studied: IOP13 & IOP16 IOP13 – 14/10/2012:  Heavy precipitation over PACA: ~75mm in 6h inland and ~150mm a few kilometers off-shore the Var department in the afternoon  2 distinct precipitating systems: a supercell and a convective line IOP16 – 26/10/2012:  Heavy precipitation: up to 100mm in 6h and ~45mm in 1h  2 precipitating systems : a MCS crossing the Gulf of Lion in the morning and a MCS reaching the Var department in the afternoon IOP13 – 14/10, 18 UTCIOP16 – 26/10, 18 UTC6h-accumulation (1/10mm)

4/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May Numerical simulation set-up Simulations with the non-hydrostatic research model Meso-NH:  Initialisation and forcing at lateral boundaries with AROME-WMED analyses, forecasts and reanalyses  Domain size  Resolution of the simulations – 2.5km and 500m in progress  Advection scheme, turbulence Very sensitive to all settings Meso-NH simulation domains

5/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May First assessment of the quality of the simulations  IOP13: oSupercell between 13:00 and 15:30 UTC not reproduced oOther convective systems quite well simulated  IOP16: oMCS over the Gulf of Lion not reproduced oMCS moving towards the Var quite well simulated until it reaches the coast IOP13 – 14/10, 17 UTC IOP16 – 26/10, 12 UTC

6/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May Comparison with HyMeX observations – IOP13 Levant wind profiler Water vapour mixing ratio from BASIL lidar Simulated radar reflectivities – 14/10, 17 UTC Simulated θ e and horizontal wind at 925hPa – 14/10, 17 UTC OBSERVATIONSOBSERVATIONS SIMULATIONSSIMULATIONS 324 K

7/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May Comparison with HyMeX observations – IOP16 Levant wind profiler RASTA cloud radar Simulated radar reflectivities – 26/10, 12 UTC Simulated θ e and horizontal wind at 925hPa – 26/10, 12 UTC OBSERVATIONSOBSERVATIONS SIMULATIONSSIMULATIONS 326 K

8/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May Further work Additional Meso-NH simulations with a 500m horizontal resolution : more accurate description of the precipitating systems. Identification of the processes triggering the convection and organising the precipitating systems: sensitivity and impact on the ambient flow, interactions between dynamics and microphysics. Building of the moisture feeding: origin of the water vapour and evolution of the air masses. Comparison with all available observations:  In-cloud measurements (RASTA, F20) and 3D radar composites of reflectivity, doppler winds and hydrometeor classification.  Ambient flow measurements from lidars, GPS, profilers, radiosoundings, balloons, ATR flights, surface observations,...

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