Initiallyplaned in Toulouse (France), the conference will be completely remote unless the improvement situation allows for some small local hubs.

The goal of this workshop is to discuss and share the latest improvements of atmospheric parameterizations for the representation of clouds with a large attention given to the use of LES. This concerns any type of models: regional or global models with numerical weather prediction or climate applications. The presentations will be organized along the 5 following themes :

•	observationsand LES for parameterization developments: systematic comparison of single-column model simulations to observations and LES on an ensemble of cases; parameterization-oriented diagnostics;
•	recentprogresses in parameterizations of cloud, turbulence, convection, microphysics including coupling between parameterizations;
•	cloudradiative effects: reference computation, cloud overlap and heterogeneity issues, new development in parameterization, coupling between radiation and other parameterizations;
•	machinelearning approaches for the tuning of free parameters and model improvement; in particular theuse of statistical tools to provide a process-oriented calibration of parameterizations;
•	thefuture for the representation of clouds in models.

It will be organized as 3 hours session per day switching from morning to afternoon session to at bestaccommodate for time difference and allow a participation from both the US or America and Asia orAustralia. This 3-hour session will include a 30-min invited talk, a 2-hour session with 10-min individual presentations and a 30-min discussion. There will be no poster session.

Please submit your abstract before 28 February 2021.
People that already submitted an abstract need to check, modify their abstract if wanted and confirm themaintenance of their submission.

Practical:
The workshop, in the spirit of the 2017 Delft meeting on the future of cumulus convection and the 2019Paracon conference, is organized in the framework of the High-Tune project (http://www.umr-cnrm.fr/high-tune/). It will be organized around with only one plenary session with a mixture of invited and contributedpresentations. The registration is free but mandatory.

Tutorials:
Two tutorials will be organized on recently developed tools within the framework of High-Tune:
i) a high-tune renderer: to allow for Monte-Carlo radiative computation on cloud scenes
from LES;
ii/ high-tuneexplorer: a process-based calibration tool will be proposed during the rest of
the time available during theweek.
Moreinformation given soon.

Side meetings:
A side meeting on the Grey-zone intercomparison will be organized (email to rachel.honnert@meteo.fr and lorenzo.tomassini@metoffice.gov.uk for interest). Other side meetings are welcome. The workshop organizing committee may help in spreading the information among the participants, if necessary.