The air quality measurements are interpolated on a 4x4 km² grid using Corine Land Cover.

Weather model INCA. Available parameters : 2m Temperature, 2m Dewpoint, 2m Relative Humidity, Snowfall level, Freezing level, 3D Temperature, 3D Humidity, 3D Wind, 10m Wind, 10m Gusts, Ground temperature, Wind chill, Precipitation, Precipitation type, Lightning, Collection of convective analysis fields:CAPE, CIN, LCL, Level of free convection,Lifted Index, Showalter Index, Deep ConvectionIndex, Trigger temperature, Trigger temperaturedeficit, Equivalent Pot. temperature, Moistureconvergence, Flow divergence, Precipitable water, Cloudiness, Visibility. This product is not publicly available yet

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.

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.

A climate normal is an average over a 30-years period. The period 1981-2010 is the current reference period recommended by the World Meteorological Organization (WMO). Recent climate normals are available for any locations in Belgium and several parameters including air temperature, precipitations and solar radiation. Climate normals for the reference period 1981-2010 are available for air temperature, precipitation and derived parameters (e.g., annual number of summer days, annual number of precipitation days, etc.). For solar radiation, the reference period had to be adjusted to 1984-2013 because of data availability. These climate normals are available as maps and as table for each Belgian municipality.

Hourly forecasts for each belgian commune, from current hour up to the next 5 days. This product is not publically available.

Weather Model 'Alaro' A numerical forecast model is a computer program that simulates the evolution of the atmosphere. Available parameters : Temperature, Max. temperature, Min. temperature, Dewpoint temperature, Wet-bulb potential temperature, Cloud cover (low, medium, high, tot.), U and V wind component, U, V and vertical velocity, Stationary boundary layer (SBL) Gust, Total precipitation, Large scale rain, Convective rain, Large scale snow, Convective snow, Relative Humidity, Specific humidity, Geopotential, Mean sea level pressure, Orography, freezing level / 0°C isotherm, Convective available potential energy (CAPE)

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 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.

RMI operates a network of 17 automatic weather stations in Belgium. These weather stations report meteorological paramaters such as air pressure, temperature, relative humidity, precipitation (quantity, duration), wind (speed, gust, direction), sunshine duration, shortwave solar radiation and infrared radiation every 10 minutes. Daily AWS data are computed from the 10-min observations.