Documentatie actuele 10-minuten geautomatiseerde grondgebaseerde in-situ meteorologische oppervlaktewaarnemingen in Nederland
KNMI verzamelt meteorologische oppervlaktewaarnemingen van automatische weerstations (in-situ) in Nederland en de BES-eilanden. Het netwerk bestaat uit locaties op zee en land, waaronder windpalen en locaties op luchthavens. De weerstations rapporteren elke 10 minuten meteorologische variabelen zoals temperatuur, relatieve vochtigheid, wind, luchtdruk, zicht, neerslag en bewolking.
Het aantal beschikbare variabelen verschilt per station. De data van de afgelopen 10 minuten is enkele minuten later beschikbaar en bevat een tijdsaanduiding dat het einde van het waarnemingsinterval in UTC aangeeft. Het is mogelijk dat de waarnemingen van een station niet direct beschikbaar zijn. Bestanden kunnen tot zeven dagen later worden bijgewerkt met ontbrekende waarnemingen.
Doel
Deze near real-time dataset stelt het KNMI in staat om ongevalideerde meteorologische waarnemingen zo snel mogelijk beschikbaar te stellen. Andere datasets zijn gevalideerd en streven naar maximale volledigheid, zoals de gegevens van daggegevens.knmi.nl.
Deze dataset bevat een historisch archief sinds 1 januari 2012. Dit archief is een geschiedenis van het near real-time product. De dataset is niet handmatig gevalideerd en is mogelijk onvolledig.
De tijden in het bestand en de bestandsnaam worden weergegeven in UTC. De tijdsaanduiding in de bestandsnaam verwijst naar het interval van 10 minuten voorafgaand aan die tijdsaanduiding. De bestandsnaam KMDS__OPER_P___10M_OBS_L2_202301010900.nc komt bijvoorbeeld overeen met het interval van 10 minuten 08:50-09:00 UTC. Voor Nederland is de lokale tijd UTC+1 (CET) en tijdens de zomertijd is de lokale tijd UTC+2 (CEST).
Individuele variabelen kunnen worden gemeten en geaggregeerd over een ander tijdsinterval. Dit kan korter of langer zijn dan het interval van 10 minuten van het bestand. Dit wordt aangegeven in de beschrijving van de variabele. De variabelen rh10, t10 en td10 hebben hun tijdsaanduiding in het midden van het tijdsinterval. In het bestand 'KMDS__OPER_P___10M_OBS_L2_202301010900.nc' is het tijdsinterval bijvoorbeeld 08:55-09:05.
Het bestand met de gegevens voor het laatste interval van 10 minuten is een paar minuten later beschikbaar. Het is mogelijk dat de waarnemingen van sommige stations niet direct beschikbaar zijn. Stations op Noordzeeplatforms worden doorgaans tijdens het volgende interval bijgewerkt. Bestanden kunnen tot 7 dagen later worden bijgewerkt met ontbrekende waarnemingen.
Het wordt sterk aangeraden om de MQTT notification service te gebruiken om op de hoogte te worden gesteld wanneer de dataset nieuwe of bijgewerkte bestanden ontvangt, zodat u altijd het nieuwste bestand ontvangt zonder onnodig te pollen of opnieuw te downloaden.
De gegevens zijn beschikbaar vanaf 1 januari 2012 tot en met het meest recente interval van 10 minuten.
De dataset is beschikbaar in NetCDF-bestanden. De bestanden kunnen worden gedownload via de Open Data API. De dataset is ook beschikbaar als de ‘10-minuten-in-situ-meteorologische-observaties' via de Environmental Data Retrieval (EDR) API. Met de EDR API is het mogelijk om de dataset op spatio-temporele wijze te bevragen op specifieke variabelen, zonder dat de gebruiker volledige datasets hoeft te downloaden.
De stations in deze dataset maken deel uit van het WMO Integrated Global Observing System (WIGOS). De dataset bevat de locatie, naam en WIGOS-identificatie van elk station.
Een historisch overzicht van een deel van de metadata van de stations wordt bewaard in de dataset van weerstations op het Data Platform. Meer metadata en informatie over de stations is te vinden in de WMO OSCAR-database.
Sommige automatische weerstations bestaan uit meerdere sublocaties waar sensoren zijn geïnstalleerd. Dit is met name het geval op luchthavens met meerdere sensoren voor luchtvaartdoeleinden. Deze dataset bevat metingen van die sensoren die zijn geïnstalleerd met minimale lokale effecten, om representatieve synoptische waarnemingen op elk station te garanderen.
Voor sommige weerstations in deze dataset geldt dat zij mogelijk nog niet volledig operationeel zijn. De gegevens zijn representatief en geldig voor de gemeten weersomstandigheden, maar zijn nog niet opgenomen in de klimatologisch gevalideerde datasets.
Niet alle stations zijn beschikbaar tijdens de volledige looptijd van de dataset. Sommige stations zijn na 2012 operationeel geworden of sindsdien uitgeschakeld. De start- en einddatums van een station kunnen teruggevonden worden in de dataset van weerstations.
In de onderstaande tabel vindt u een lijst met alle variabelen die beschikbaar zijn op een of meer stations, met hun beschrijving en eenheden. Naast sommige variabelen vindt u mogelijk opmerkingen, deze staan in de onderstaande tabel.
| Parameter | Description | Unit | Observed property | Comment |
|---|---|---|---|---|
| D1H | Past hour rainfall duration in minutes | min | Precipitation Duration | |
| dd | Past 10 minute mean wind direction in degrees, measured at sensor height, with Marked Discontinuity (MD) | ° | Wind from direction | *1 |
| dn | Past 10 minute minimum wind direction in degrees, measured at sensor height, with Marked Discontinuity (MD) | ° | Wind from direction | *1 |
| dr | Past 10 minute duration of precipitation in seconds, measured by rain gauge | s | Precipitation Duration | |
| dsd | Past 10 minute standard deviation of wind direction in degrees, measured at sensor height, with Marked Discontinuity (MD) | ° | Wind from direction | *1 |
| dx | Past 10 minute maximum wind direction in degrees, measured at sensor height, with Marked Discontinuity (MD) | ° | Wind from direction | *1 |
| ff | Past 10 minute mean wind speed, representative for 10 meters, in meters per second, with Marked Discontinuity (MD) | m/s | Wind speed | *1 |
| ffs | Past 10 minute mean wind speed, measured at sensor height, in meters per second, with Marked Discontinuity (MD) | m/s | Wind speed | *1 |
| fsd | Past 10 minute standard deviation of wind speed, measured at sensor height, in meters per second, with Marked Discontinuity (MD) | m/s | Wind speed | *1 |
| fx | Past 19 minute maximum wind gust, representative for 10 meters, in meters per second | m/s | Wind speed of gust | *1 |
| fxs | Past 19 minute maximum wind gust, measured at sensor height, in meters per second | m/s | Wind speed of gust | *1 |
| gff | Past 10 minute maximum wind gust, representative for 10 meters, in meters per second, with Marked Discontinuity (MD) | m/s | Wind speed of gust | *1 |
| gffs | Past 10 minute maximum wind gust, measured at sensor height, in meters per second, with Marked Discontinuity (MD) | m/s | Wind speed of gust | *1 |
| h | Past 10 minute cloud base altitude, in feet | ft | Cloud base altitude | *2 |
| h1 | Past 10 minute first layer cloud base altitude, in feet | ft | Cloud base altitude | *2 |
| h2 | Past 10 minute second layer cloud base altitude, in feet | ft | Cloud base altitude | *2 |
| h3 | Past 10 minute third layer cloud base altitude, in feet | ft | Cloud base altitude | *2 |
| hc | Past 10 minute cloud base ceilometer, in feet | ft | Cloud base altitude | *2 |
| hc1 | Past 10 minute first layer cloud base ceilometer, in feet | ft | Cloud base altitude | *2 |
| hc2 | Past 10 minute second layer cloud base ceilometer, in feet | ft | Cloud base altitude | *2 |
| hc3 | Past 10 minute third layer cloud base ceilometer, in feet | ft | Cloud base altitude | *2 |
| n | Past 10 minute total cloud cover, in okta | okta | Cloud area fraction | |
| n1 | Past 10 minute first layer cloud amount, in okta | okta | Cloud area fraction | |
| n2 | Past 10 minute second layer cloud amount, in okta | okta | Cloud area fraction | |
| n3 | Past 10 minute third layer cloud amount, in okta | okta | Cloud area fraction | |
| nc | Past 10 minute total cloud cover ceilometer, in okta | okta | Cloud area fraction | |
| nc1 | Past 10 minute first layer cloud amount ceilometer, in okta | okta | Cloud area fraction | |
| nc2 | Past 10 minute second layer cloud amount ceilometer, in okta | okta | Cloud area fraction | |
| nc3 | Past 10 minute third layer cloud amount ceilometer, in okta | okta | Cloud area fraction | |
| nhc | Past 10 minute low and middle cloud amount ceilometer, in okta | okta | Cloud area fraction | |
| p0 | Past minute mean air pressure at station level | hPa | Air pressure | |
| pg | Past 10 minute mean precipitation intensity in millimeters per hour, measured by Present Weather Sensor | mm/h | Lwe precipitation rate | *3 |
| pp | Past minute mean air pressure at mean sea level in hectopascal | hPa | Air pressure at mean sea level | |
| pr | Past 10 minute duration of precipitation in seconds, measured by Present Weather Sensor | s | Precipitation Duration | *3 |
| ps | Past 10 minute mean air pressure at sensor level in hectopascal | hPa | Air pressure | |
| pwc | Past 10 minute corrected maximum precipitation type; Handboek waarnemingen. 5.3 PW-code neerslagsoort; https://www.knmi.nl/kennis-en-datacentrum/publicatie/handboek-waarnemingen | 一 | Predominant precipitation type at surface | *3 |
| Q1H | Past hour sum of global radiation in the last hour, in joules per square centimeter | J/cm² | Integral wrt time of surface downwelling shortwave flux in air | |
| Q24H | Past 24 hour sum of global radiation, in joules per square centimeter | J/cm² | Integral wrt time of surface downwelling shortwave flux in air | |
| qg | Past 10 minute mean global solar radiation in watt per square meter | W/m² | Surface downwelling shortwave flux in air | |
| qgn | Past 10 minute minimum global solar radiation, in watt per square meter | W/m² | Surface downwelling shortwave flux in air | |
| qgx | Past 10 minute maximum global solar radiation, in watt per square meter | W/m² | Surface downwelling shortwave flux in air | |
| qnh | Past minute mean QNH, in hectopascal | hPa | Air pressure at mean sea level | |
| R12H | Past 12 hour rainfall, in millimeters | mm | Rainfall amount | |
| R1H | Past hour rainfall, in millimeters | mm | Rainfall amount | |
| R24H | Past 24 hour rainfall, in millimeters | mm | Rainfall amount | |
| R6H | Past 6 hour rainfall, in millimeters | mm | Rainfall amount | |
| rg | Past 10 minute mean precipitation intensity in millimeters per hour, measured by rain gauge | mm/h | Lwe precipitation rate | |
| rh | Past minute mean relative humidity at 1.50 meters, in percentage | % | Relative humidity | *4 |
| rh10 | 10 minute mean relative humidity, in percentage | % | Relative humidity | *5 |
| Sav1H | Past hour mean wind speed, in meters per second | m/s | Wind speed | *6 |
| Sax1H | Past hour maximum wind speed, in meters per second | m/s | Wind speed | *6 |
| Sax3H | Past 3 hour maximum wind speed, in meters per second | m/s | Wind speed | *6 |
| Sax6H | Past 6 hour maximum wind speed, in meters per second | m/s | Wind speed | *6 |
| sq | Past 10 minute squall indicator, 0: no squall, 1: squall, or empty | 一 | squall indicator | |
| ss | Past 10 minute duration of sunshine in minutes | min | Duration of sunshine | |
| Sx1H | Past hour maximum wind gust, in meters per second | m/s | Wind speed of gust | *6 |
| Sx3H | Past 3 hour maximum wind gust, in meters per second | m/s | Wind speed of gust | *6 |
| Sx6H | Past 6 hour maximum wind gust, in meters per second | m/s | Wind speed of gust | *6 |
| t10 | 10 minute mean air temperature, in degrees Celsius | °C | Air temperature | *7 |
| ta | Past minute mean air temperature at 1.50 meters, in degrees Celsius | °C | Air temperature | *8 |
| tb | Past 10 minute mean wet bulb temperature at 1.50 meters, in degrees Celsius | °C | Wet bulb temperature | |
| tb1 | Past 10 minute mean soil temperature at -5 centimeters, in degrees Celsius | °C | Soil temperature | |
| Tb1n6 | Past 6 hour minimum soil temperature at -5 centimeters, in degrees Celsius | °C | Soil temperature | |
| Tb1x6 | Past 6 hour maximum soil temperature at -5 centimeters, in degrees Celsius | °C | Soil temperature | |
| tb2 | Past 10 minute mean soil temperature at -10 centimeters, in degrees Celsius | °C | Soil temperature | |
| Tb2n6 | Past 6 hour maximum soil temperature at -10 centimeters, in degrees Celsius | °C | Soil temperature | |
| Tb2x6 | Past 6 hour maximum soil temperature at -10 centimeters, in degrees Celsius | °C | Soil temperature | |
| tb3 | Past 10 minute mean soil temperature at -20 centimeters, in degrees Celsius | °C | Soil temperature | |
| tb4 | Past 10 minute mean soil temperature at -50 centimeters, in degrees Celsius | °C | Soil temperature | |
| tb5 | Past 10 minute mean soil temperature at -100 centimeters, in degrees Celsius | °C | Soil temperature | |
| td | Past minute mean dew point temperature at 1.50 meters, in degrees Celsius | °C | Dew point temperature | *9 |
| td10 | 10 minute mean dew point temperature, in degrees Celsius | °C | Dew point temperature | *7 |
| tg | Past 10 minute mean air temperature at 10 centimeters, in degrees Celsius | °C | Air temperature | |
| tgn | Past 10 minute minimum air temperature at 10 centimeters, in degrees Celsius | °C | Air temperature | |
| Tgn12 | Past 12 hour minimum air temperature at 10 centimeters, in degrees Celsius | °C | Air temperature | |
| Tgn14 | Past 14 hour minimum air temperature at 10 centimeters, in degrees Celsius | °C | Air temperature | |
| Tgn6 | Past 6 hour minimum air temperature at 10 centimeters, in degrees Celsius | °C | Air temperature | |
| tn | Past 10 minute minimum air temperature at 1.50 meters, in degrees Celsius | °C | Air temperature | |
| Tn12 | Past 12 hour minimum air temperature, in degrees Celsius | °C | Air temperature | |
| Tn14 | Past 14 hour minimum air temperature, in degrees Celsius | °C | Air temperature | |
| Tn6 | Past 6 hour minimum air temperature, in degrees Celsius | °C | Air temperature | |
| tsd | Past 10 minute standard deviation of all air temperature samples, in degrees Celsius | °C | Air temperature | |
| tx | Past 10 minute maximum air temperature at 1.50 meters, in degrees Celsius | °C | Air temperature | |
| Tx12 | Past 12 hour maximum air temperature, in degrees Celsius | °C | Air temperature | |
| Tx24 | Past 24 hour maximum air temperature, in degrees Celsius | °C | Air temperature | |
| Tx6 | Past 6 hour maximum air temperature, in degrees Celsius | °C | Air temperature | |
| vv | Past 10 minute mean horizontal visibility, in meters | m | Visibility in air | *3 |
| W10 | Past 10 minute Past Weather Indicator (W10); Handboek waarnemingen. 5.4 Weercodegenerator. Tabel 6; https://www.knmi.nl/kennis-en-datacentrum/publicatie/handboek-waarnemingen | 一 | Present weather code | *3 |
| W10-10 | Previous 10 minute interval Past Weather Indicator (W10); Handboek waarnemingen. 5.4 Weercodegenerator. Tabel 6; https://www.knmi.nl/kennis-en-datacentrum/publicatie/handboek-waarnemingen | 一 | Present weather code | *3 |
| ww | Past 10 minute WaWa Weather Code; Handboek waarnemingen; 5.4 Weercodegenerator; Tabel 6; https://www.knmi.nl/kennis-en-datacentrum/publicatie/handboek-waarnemingen | 一 | Present weather code | *3 |
| ww-10 | Previous 10 minute interval WaWa Weather Code Handboek waarnemingen; 5.4 Weercodegenerator; Tabel 6; https://www.knmi.nl/kennis-en-datacentrum/publicatie/handboek-waarnemingen | 一 | Present weather code | *3 |
| za | Past 10 minute mean background luminance, in candela per square meter | cd/m² | Background Luminance | *3 |
| zm | Past 10 minute mean meteorological optical range, in meters | m | Meteorological optical range | *3 |
Een aantal variabelen hebben een opmerking om extra context te geven aan de waarnemingen. De opmerkingen komen uit de metadata van de dataset, waardoor de opmerkingen in het Engels zijn.
| Nummer | Opmerking |
|---|---|
| 1 | MD: Marked Discontinuity is an abrupt change in the 2-minute average wind speed and/or direction. This is defined per WMO and ICAO guidelines as more than 10 knots and/or 30 degrees absolute difference between two successive 2-minute periods when the wind speed > 10 knots in one or both periods. When a MD is detected, all data older than 2 minutes are excluded from calculation. Variables indicated with MD are therefore calculated based on the samples measured within the previous 2 minutes at minimum, up to the full 10-minute period. Note: For wind observations of stations 0-20000-0-06209, 0-20000-0-06285, 0-20000-0-06308, 0-20000-0-06312, 0-20000-0-06313, 0-20000-0-06315, 0-20000-0-06316, 0-20000-0-06324, 0-20000-0-06331 the timestamp indicates the middle of the interval. At other locations the timestamp of the wind observations indicates the end of the interval. The wind sensors at stations 0-20000-0-06225, 0-20000-0-06229, 0-20000-0-06242, 0-20000-0-06258, 0-20000-0-06260, 0-20000-0-06310, 0-20000-0-06330 and 0-20000-0-06343 are located at different heights above the surrounding terrain than the standard 10 m height, and the 10 m wind speeds (ff, fx, gff) are copies of the wind speed measured at the height of the wind sensor (ffs, fxs, gffs respectively). The standard deviation of the wind speed (fsd) is not corrected for non-standard measurement height. At certain wind masts of Rijkswaterstaat (0-20000-0-06209, 0-20000-0-06225, 0-20000-0-06229, 0-20000-0-06285, 0-20000-0-06308, 0-20000-0-06312, 0-20000-0-06313, 0-20000-0-06315, 0-20000-0-06316, 0-20000-0-06324, 0-20000-0-06331) and the platforms on the North Sea (0-20000-0-06201, 0-20000-0-06203, 0-20000-0-06204,0-20000-0-06205, 0-20000-0-06207, 0-20000-0-06208, 0-20000-0-06211, 0-20000-0-06214, 0-20000-0-06239, 0-20000-0-06252, 0-20000-0-06320, 0-20000-0-06321, 0-528-0-06317), the wind speed is also measured at heights above mean sea level differing from 10 m but the 10 m wind speeds are estimates of the wind speed that would have been measured at 10 m height, based on the sensor height measurements. |
| 2 | Note: The cloud base parameters should be evaluated as a set. The absence of clouds measured at a layer is indicated by a cloud layer cover of 0 okta and cloud layer altitude of 0 feet. |
| 3 | Note: The sensor is not installed at equal heights at all types of measurement sites: At 'AWS' sites the device is installed at 1.80m. At 'AWS/Aerodrome' and 'Mistpost' (note that this includes site 0-20000-0-06215 (Voorschoten which is 'AWS/Mistpost') the device is installed at 2.50 m elevation. Exceptions are 0-20000-0-06249 (Berkhout AWS), 0-20000-0-06260 (De Bilt AWS) and 0-20000-0-06290 (Twenthe Airport AWS) where the sensor is installed at 2.50 m. |
| 4 | Note: For some locations only rh10 is provided |
| 5 | Note: For this variable the timestamp indicates the middle of the 10 Min interval |
| 6 | Note: For wind observations of stations 0-20000-0-06209, 0-20000-0-06285, 0-20000-0-06308, 0-20000-0-06312, 0-20000-0-06313, 0-20000-0-06315, 0-20000-0-06316, 0-20000-0-06324, 0-20000-0-06331 the timestamp indicates the middle of the interval. At other locations the timestamp of the wind observations indicates the end of the interval. The wind sensors at stations 0-20000-0-06225, 0-20000-0-06229,0-20000-0-06242, 0-20000-0-06258, 0-20000-0-06260, 0-20000-0-06310, 0-20000-0-06330 and 0-20000-0-06343 are located at different heights above the surrounding terrain than the standard 10 m height, and the 10 m wind speeds (ff, fx, gff) are copies of the wind speed measured at the height of the wind sensor (ffs, fxs, gffs respectively). The standard deviation of the wind speed (fsd) is not corrected for non-standard measurement height. At the wind masts of Rijkswaterstaat (mainly in the region Zeeland) and the platforms on the North Sea, the wind speed is also measured at heights above mean sea level differing from 10 m but the 10 m wind speeds are estimates of the wind speed that would have been measured at 10 m height, based on the sensor height measurements. |
| 7 | Note: for this variable the timestamp indicates the middle of the 10 Min interval |
| 8 | Note: For some locations only t10 is provided |
| 9 | Note: For some locations only td10 is provided |