The ceilometer CL51 employs a pulsed diode laser LIDAR technology, where short, powerful laser pulses are sent out in a vertical or near-vertical direction. The reflection of light (backscatter) caused by clouds, precipitation or other obscuration is analysed and used to determine the cloud base height, the cloud layer height and the amount of clouds (in octas) in different layers.

Since August 2019, users of the RMI smartphone app are able to send an observation of the meteorological conditions at a certain place and a certain time. The observations provide information about the weather conditions and potentially severe weather to the other users and to RMI. The collection of citizen weather reports is a valuable complement to the information obtained with the classical instruments like stations, radar and satellite. The data can be exploited for nowcasting, warnings and model verification, and eventually in assimilation. A general introduction of the data and their characteristics can be found in Reyniers et al. (2023). A basic quality control is implemented on the received observations via a plausibility check. This plausibility check determines whether an observation is plausible, suspicious or false, by comparing it to the INCA-BE nowcasting system using a simple thresholding scheme. INCA-BE is RMI's operational nowcasting system described in Reyniers et al. (2021). There is no strict spatial extent since there is no restriction at the input side: users can send observations from all over the globe. The bulk of the observations are received from within Belgium. Note that the plausibility check is not available for reports from outside Belgium.

The composite is produced every 5 minutes using the reflectivity data from the Wideumont and Jabbeke weather radars. This product is not publicly available yet.

View Service (WMS) for Networks of automatic lidar-ceilometer systems The data are updated each 10 minutes. Only the archives of the last 30 days are available.

From multiple observations during the day with UV spectrophotometers a daily value of the ozone column is calculated. This product is not publically available yet.

View Service (WMS) for Automatic weather station (AWS) observations

Hail products are derived from the observed vertical profiles of radar reflectivity and the NWP vertical profiles of temperature. Three types of products are generated. poh : probability of hail of any size (larger than 0.5 cm diameter)expressed in %. posh : probability of severe hail(larger than 2cm)expressed in %. mesh : maximum expected size of hailexpressed in mm of hailstone diameter. All products are generated every 5 minutes. This product is not publically available yet.

View Service (WMS) for Synoptic observations

The climatological network contains about 200 stations spread over the whole country. It consists of voluntary observers recruited by the RMI, professional observers of Skeyes (civil aviation) or the Air Force (military aviation) and civil servants of the state, communities or private companies. The observers measure the amount of rain fallen in the last 24 hours in the pluviometer of the RMI every morning at 8 o‘clock. In more than half of the stations the extreme air temperatures are also recorded by reading the maximum and minimum temperature in a standardized weather shelter. The observers send their observations either on a  daily or on a monthly basis to RMI. This product is not publicly available yet.