Deadline for manuscript submissions: 29 March 2020.

Dear Colleagues,

As global temperature increases, global mean extreme precipitation is predicted to increase at about the same rate as global mean atmospheric water vapor, that is, at about 7.5% per degree Celsius warming, following the Clausius–Clapeyron equation. At the regional scale, changes in extreme precipitation may be quite different from the large-scale average, and the attribution of regional–local extreme precipitation events to the warming climate involves several uncertainties. To understand the effects of climate on extreme events at the local scale is an issue of significant societal importance. The essential need is the understanding of the processes involved in order to establish the connections between the projected climate change and changes in the frequency, intensity and duration of precipitation.

To provide insight into extreme precipitation at regional and local scales global climate models are inadequate because of the coarse resolution of terrain features and other mesoscale effects. Regional climate models (RCMs) represent local-scale weather by refining the spatial resolution over a limited area, providing a better representation of orographic effects, regional variations in land surface characteristics, mesoscale weather systems, and related phenomena. However, as was pointed out by the fifth assessment report of the IPCC, regional modeling requires substantial advancement to improve the confidence of precipitation projections and become a useful decision support tool in climate impacts assessment. A better understanding of the model limitations, model errors and model sensitivity to boundary conditions, parameterizations, and other factors is of main interest to avoid blurred conclusions. Obtaining a more accurate high-resolution representation of intense precipitation, is a necessary prerequisite to develop any reliable assessment of the hydrometeorological risk in future climate change scenarios.

Under these considerations, the aim of this special issue is to document the current state of knowledge of the factors involved in the extreme precipitation by focusing on the problems that RCMs have to represent extreme events in order to improve RCMs. To bring light to these questions, we invite you to submit articles to this special issue that will contribute to advancement in the knowledge of regional climate modeling of extreme precipitation events including heavy rainfall, snow storms, and drought. Solicited contributions include but are not limited to:

Sensitivity to higher spatial resolution paying special attention to convection permitting simulation and, how higher temporal resolution improves the timing and duration of precipitation (e.g. "triggers" and the suppression of convection),
Sensitivity to the physical parameterizations (e.g. cumulus and microphysics),
The role of sources, sinks and transport of moisture at the low atmosphere (e.g. atmospheric rivers),
Feedbacks aerosol-precipitation including aerosol-radiation effects (ARI) and aerosols-cloud effects (ACI)
RCMs sensitivity to the initial and boundary conditions
Uncertainties in extreme precipitation validation when are compared against different observational data bases

Dr. Raquel Lorente-Plazas
Dr. Eric Salathé
Dr. Jorge Eiras-Barca
Guest Editors