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

RADQPE provides high resolution radar-based quantitative precipitation estimation in realtime for Belgium and its surroundings. This product is not publically available yet.

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.

Bird density profiles are derived from weather radar volume data in real time, by the vol2bird algorithm as described in Dokter et al. (2011, 2019). The vol2bird algorithm exploits the radar reflectivity characteristics of different scatterers in the atmosphere, in order to distinguish biological from non-biological radar echoes. Once biological scatterers are isolated in the volume files, the reflectivity of these scatterers is converted in an estimate of the bird density per vertical layer of 200m, using a mean cross section of 11 cm2. The vbird profiles are provided for the following radars, with the radar owner in parentheses: Jabbeke (RMI), Wideumont (RMI), Helchteren (VMM), Zaventem (Skeyes), Herwijnen (KNMI), Den Helder (KNMI), Neuheilenbach (DWD), Essen (DWD), Abbeville (Météo-France) and Avesnois (Météo-France). References: - Dokter A.M., Liechti F., Stark H., Delobbe L., Tabary P., Holleman I., Bird migration flight altitudes studied by a network of operational weather radars, J. R. Soc. Interface, 8, 30–43, 2011, DOI 10.1098/rsif.2010.0116 - Dokter A.M., Desmet P., Spaaks J.H., van Hoey S., Veen L., Verlinden L., Nilsson C., Haase G., Leijnse H., Farnsworth A., Bouten W., Shamoun-Baranes J., bioRad: biological analysis and visualization of weather radar data, Ecography, 42, 852-860, 2019, DOI 10.1111/ecog.04028

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.

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.

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. Hourly AWS data are computed from the 10-min observations.

Total lightning observations, i.e., cloud-to-ground (CG) strokes and intra/inter-cloud (IC) pulses, in Belgium. BELLS data is given in Universal Time! (local time winter = UT +1; local time summer = UT + 2). Each record contains following fields: 1. Network type, 0 = LF, 1 = VHF-TOA, 2 = VHF-ITF, 3 = VLF 2. Year, 1970 to 2032. 3. Month, with January as 1 and December as 12. 4. Day of the month, 1 to 31. 5. Hour, 0 to 23. 6. Minute, 0 to 59. 7. Second, 0 to 60. 8. Nanosecond, 0 to 999999999. 9. Latitude of the calculated location in decimal degrees, to 4 decimal places, -90.0 to 90.0. 10. Longitude of the calculated location in decimal degrees, to 4 decimal places, -180.0 to 180.0. 11. Altitude in meters, -4950 to +60535. This field will be 0 if the altitude is not provided in the lightning data. 12. The altitude uncertainty in meters. This field will be 0 if the altitude uncertainty is not provided in the lightning data. 13. Estimated peak current in kiloamps, -9999 to 9999. 14. VHF Range normalized power, -9999.0 to 9999.0 15. Multiplicity for flash data (1 to 99) or 0 for strokes. 16. Cloud pulse count for the lightning record. This field will be -1 if the lightning did not contain the cloud pulse count attribute. 17. Number of sensors participating in the solution, 2 to 99. 18. Degrees of freedom when optimizing location, 0 to 99. 19. The error ellipse angle as a clockwise bearing from 0 degrees north, 0 to 180.0 degrees 20. The error ellipse semi-major axis length in kilometers, 0 to 50.0km. 21. The error ellipse semi-minor axis length in kilometers, 0 to 50.0km. 22. Chi-squared value from location optimization, 0 to 999.99 23. Rise time of the waveform in microseconds, 0 to 99.9 24. Peak-to-zero time of the waveform in microseconds, 0 to 999.9 25. Maximum rate-of-rise of the waveform in kA/usec (will be a negative rate if discharge is negative), -999.9 to 999.9 26. Cloud indicator, 1 if Cloud-to-cloud discharge, 0 for Cloud-to-ground 27. Angle indicator, 1 if sensor angle data used to compute position, 0 otherwise 28. Signal indicator, 1 if sensor signal data used to compute position, 0 otherwise 29. Timing indicator, 1 if sensor timing data used to compute position, 0 otherwise 30. Flash ID, a unique integer value identifying the flash grouping a stroke belongs to or 0 if not set. This product is not publically available yet.

Hourly warnings of dangerous meteorological phenomena (wind, rain, ice or snow, fog, storm surge, thunderstorm) issued by the RMI, based on the estimated impact.

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.