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.

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.

The SYNOP data of RMI contain the observations of the synoptic network, currently consisting of 29 stations, 13 of which are owned by RMI. The other stations belong to MeteoWing (8 stations), Skeyes (7 stations). There is also 1 foreign station. All SYNOP data is given in Universal Time! (local time winter = UT +1; local time summer = UT + 2) Parameters: 1. Precipitation: PRECIP_QUANTITY + PRECIP_RANGE 2. Temperature: TEMP + TEMP_MIN + TEMP_MAX + TEMP_GRASS_MIN 3. Wind: WIND_SPEED + WIND_SPEED_UNIT + WIND_DIRECTION + WIND_PEAK_SPEED 4. relative humidity: HUMIDITY_RELATIVE 5. weather type: WEATHER_CURRENT 6. air pressure: PRESSURE of PRESSURE_STATION_LEVEL 7. sunshine duration: SUN_DURATION_24H 8. Global radiation: SHORT_WAVE_FROM_SKY_24HOUR 9. Total cloudiness: CLOUDINESS

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)

Daily forecasts for each Belgian commune, from current day up to the next 14 days. Available parameters are : min temperature, max temperature, weather type, wind speed, wind direction, maximum hust speed, quantity of precipitation. This product is not publicly available.

UV Index derived from spectral measurements with a Brewer UV spectrophotometer. This product is not publically available yet.

Gridded observational data provides an estimate of the spatial distribution of a meteorological variable based on observations. While instrumental measurements are taken at irregularly distributed stations, gridded data represents the meteorological variable on a predefined regular grid. Gridded observational data is of strong benefit in disciplines applying distributed quantitative models to examine the influence of weather and climate. Gridded data are also very convenient to provide estimations for any specific location of interest for the user. Gridded observational data covering Belgium at a spatial resolution of 5 km (= 1360 pixels) are available for several variables (precipitations, air temperature, sunshine duration, solar radiation, relative humidity and wind speed) as well as different temporal resolutions (daily, monthly, seasonal, annual values as well as long-term climate averages). The gridded database starts in 1961 for most variables and is updated each day with the available observations of the previous day. All grids are then updated for archiving as soon as the data quality control is completed. In addition to the 5km x 5km grids, spatial averages for all each Belgian municipality are also available. This product is not publically available yet. The daily gridded climate data are available for academic profiles after registration on our open data website.

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.

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.