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 2014 -

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

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2 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 UTC IOP16 – 26/10, 18 UTC6h-accumulation(1/10mm)

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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

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First assessment of the quality of the simulations

IOP13:o Supercell between 13:00 and 15:30 UTC not reproducedo Other convective systems quite well simulated

IOP16:o MCS over the Gulf of Lion not reproduced o MCS moving towards the Var quite well simulateduntil it reaches the coast

IOP13 – 14/10, 17 UTC IOP16 – 26/10, 12 UTC

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Comparison with HyMeX observations – IOP13

Levant wind profilerWater vapour mixing ratio from BASIL lidar

Simulated radar reflectivities – 14/10, 17 UTC

Simulated θe and horizontal wind at 925hPa – 14/10, 17 UTC

OBSERVATIONS

SIMULATIONS

324 K

7/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May 2014 -

Comparison with HyMeX observations – IOP16

Levant wind profilerRASTA cloud radarSimulated radar reflectivities – 26/10, 12 UTC

Simulated θe and horizontal wind at 925hPa – 26/10, 12 UTC

OBSERVATIONS

SIMULATIONS

326 K

8/8 - HyMeX ST-WV meeting - F. Duffourg - Toulouse, France, 15 May 2014 -

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, ...

Thank you !