Time series of hourly measurements or modelled values of surface solar irradiation are increasingly available. Currently, no solar zenith and azimuth angles are associated to each measurement whereas such angles are necessary for handling the measured or modelled irradiations. A method is proposed to assess such angles with a great accuracy. It makes use of two modelled time-series that can be computed using the web site www.soda-pro.com for any site in the world.

Three heavy rain events over NE Alps were simulated using a high-resolution model to evaluate the effect of the SST of the Adriatic Sea. These preliminary results show that SST influences the surface heat fluxes over the sea, but does not necessary affect the vertical integrated water vapour flux across the coast. The response of heavy precipitation to a SST change is complex: SST affects the PBL characteristics and thus the flow dynamics and its interaction with orography.

This paper describes the quality control procedures developed at the Royal Meteorological Institute of Belgium (RMI) to ensure the accuracy and reliability of the wind observations performed within the Automatic Weather Stations network operated by RMI.

The new CAMS (Copernicus Atmosphere Monitoring Service) McClear service is a practical easy-to-use tool to estimate the solar direct and global irradiances received at ground level in cloud-free conditions at any place any time. This article presents validation against 1 min measurements made at three very close stations in Israel in desert conditions. The good results demonstrate the accuracy of McClear and its ability to capture the temporal and spatial variability of the irradiance field.

In this study a precipitation nowcasting method is developed which relies on satellite products and automatic weather station data only. It thus omits ground based radar observations which are not readily available in large parts of the world. The system shows improved skill when compared to numerical weather prediction models for analysis and for lead times up to one hour. This type of nowcasting could be valuable in data sparse regions where radar observations are lacking or of poor quality.

Since 1953, the 15 climate stations on the Canadian Prairie have made unique hourly observations of opaque reflective cloud, as well as temperature, humidity, wind, precipitation and snow depth. These observations have shown that snow cover cools the local climate by 10 °C, and transforms how clouds drive the daily cycle of temperature and humidity. The replacement of summer fallow by intensive cropping has cooled and moistened the growing season climate and increased summer precipitation.

For 30 years, a Canadian research team has used an atmospheric research aircraft in measurement campaigns to improve our understanding of the controls on land-surface fluxes. The vertical flux of sensible and latent heat, momentum, and several trace gases were measured, along with supporting data. We document the data collected from 1987 to 2011, provide technical details of the measurement campaigns, present interesting results, and describe our approach to make the data publicly accessible.

The use of seasonal forecast, combined with an impact model, could have a tangible positive effect on long-term decisions. This paper presents such an example for the management of a dam in France, studied in the framework of the FP7 project EUPORIAS. It details the assessment process, lead in collaboration with the stakeholder, especially the evaluation of the decision itself. It demonstrates that the introduction of relevant climate products could significantly improve existing practice.

Mesoscale wind fluctuations lead to high wind fluctuations. Enhanced mesoscale wind variability emerges during cold air outbreaks and resulting convection. If these fluctuation occurs during cellular convection, the question arises if it is possible to estimate the spatial variability of the wind by the solar irradiance variability? Cellular convection leads to simultaneous high solar and wind variability, but the highest solar or wind variability occurs due to other meteorological phenomena.

Numerical weather prediction model forecasts at hectometric resolution are now possible. This range of scales is called the "grey zone of turbulence" as turbulence structures are neither mainly resolved nor entirely subgrid. Turbulence parametrizations have to be adapted, and the adaptations at these scales depend on the existing parametrizations at larger or smaller scales. This study explains the modifications in current Météo France models to the grey zone of turbulence.

The improvement of the Solar and Wind short-term forecasting represents a critical goal for the weather prediction community and is of great importance for a better estimation of power production from solar and wind farms. In this work we analyze the performance of two deterministic models operational at ISAC-CNR for the prediction of short-wave irradiance and wind speed, at two experimental sites in southern Italy.

As an island located in the North Atlantic Ocean with a highly energetic wave and wind climate, Ireland is uniquely placed in terms of its ocean renewable energy resource. The socio-economic importance of this resource makes it a priority to quantify how the wave and wind climate may change in the future. We examine how surface winds in the North Atlantic Ocean may change towards the end of this century due to global climate change, and how these changes may affect Ireland's wave climate.

Several satellite-derived solar surface irradiance databases provide long-term and homogeneously distributed information on the solar potential at ground level. This paper presents the validation results of three of these databases: HelioClim-3 (versions 4 and 5) and the CAMS radiation service, versus the measurements of 42 stations in Brazil. Despite a slight overestimation of the CAMS radiation service, the three databases are suitable for studies of the solar resources in Brazil.

To respond to the challenges of climate change, Angola, Botswana, Germany, Namibia, South Africa and Zambia have initiated the regional competence centre SASSCAL. As part of the initiative, Deutscher Wetterdienst (DWD) cooperates with the meteorological services of Angola, Botswana and Zambia to improve the management of climate data. First results of the cooperation between DWD and the Angolan Meteorological Services (INAMET) are presented in order to provide hints for comparable activities.

Simulated surface winds in atmospheric models depend, among others, on the parameterization of the sea surface roughness. Three parameterizations (variation of Charnock parameter) were tested in the western Mediterranean area during Mistral events with the regional climate model COSMO-CLM. While the whole sea level pressure pattern did not change much, a larger Charnock parameter led to lower wind speeds and a rotation of the wind direction.

Warnings have become a standard product in meteorological centres since they help the public prevent major disasters and minimize costs or losses. They happen rarely and add a new temporal dimension, namely the time window of the forecasted event. Thus, specific verification methods are required to verify warnings. This paper analyses the warning verification issues and includes a real life example, the verification of wind gust warnings at the German Meteorological Centre (Deutscher Wetterdienst).

The continuous wavelet (CWT) and the Hilbert–Huang transforms (HHT) are compared for the analysis of the temporal variability on ten years of daily means of the surface solar irradiance. In both cases, the variability exhibits a plateau between scales of two days and three months that has decreasing power with increasing scale, a spectral peak corresponding to the annual cycle, and a low power regime in-between. The HHT is shown to be suitable for inspecting the variability of the measurements.

HelioClim-3 (version 4) is a satellite-derived solar surface irradiance database available at d-1 until 2015. To fulfill the requirements of numerous users, a new service based on the principle of persistence has been developed; it provides solar data in real time and forecasts until the end of the current day. The service exhibits good performances for 15 min and 1 h ahead forecasts, and degrades as the temporal horizon increases. Several customers have so far purchased this service.

Facebook is one of the most used social networks and it represents a perfect virtual platform to share information and to promote active and immediate interaction amongst users. This is why many NMSs develop new communication strategies and incorporate this tool for different purposes. In this paper we investigate how Facebook was introduced in different NMSs worldwide as an additional tool for the diffusion of meteorological information and interction with users.

Wind speeds derived from the regional reanalysis COSMO-REA6 and from two global reanalyses of ECMWF (ERA-Interim and ERA-20C) have been compared to tower measurements covering heights from 10 m up to 140 m, located in the North Sea, in The Netherlands, and in Northeast Germany. In general, the monthly and hourly mean values of COSMO-REA6 are at least as close to the measurements as the global reanalyses, and in the correlation of daily means an added value of COSMO-REA6 is found.

Germany's national meteorological service (DWD) operates a network of so-called climate reference stations. At these stations parallel measurements are performed in order to allow the comparison of manual and automatic observations. We present an analysis of parallel measurements of temperature at 2 m height. It is shown that the automation of stations did not cause an artificial increase in the series of daily mean temperature. A bias occurs for maximum temperature in specific configurations.