GEN 3.5 METEOROLOGICAL SERVICES
1 RESPONSIBLE SERVICE
1.1 KNMI Aviation Services
The Royal Netherlands Meteorological Institute (KNMI) is designated as the meteorological authority for the provision of meteorological service for (international) air navigation in the Netherlands.
KNMI Aviation Services is the subdivision of the Institute charged with the provision of meteorological information.
KNMI Aviation Services
P.O. Box 201
3730 AE De Bilt
Tel: +31 (0)30 220 6721
Fax: +31 (0)30 221 1371
Email: aviation@knmi.nl
AFS: EHDBYZYX
URL: http://www.knmi.nl
1.2 Applicable ICAO documents
The international Standards, Recommended Practices and Procedures contained in the following ICAO documents are applicable:
| Annex 3 | Meteorological Service for International Air Navigation |
| DOC 7030 Part 3 | Regional Supplementary Procedures |
| Air Navigation Plan | EUR BANP, WD, Part VI-MET EUR FASID, WD, Part VI-MET, Tables EUR FASID, WD, Part VI-MET, Text |
Differences to these provisions are detailed in GEN 1.7.
2 AREA OF RESPONSIBILITY
KNMI Aviation Services at De Bilt is the meteorological watch office (MWO, tel: +31 (0)30 220 6581, watch only) designated to maintain the meteorological watch in the flight information region Amsterdam (see ENR 6-3.1 and ENR 6-3.2).
3 METEOROLOGICAL OBSERVATIONS AND REPORTS
| Name of station Location indicator | Type & frequency of observation/ automatic observing system | Types of MET reports & supplementary information included | Observation system & sites | Hours of operation | Climatological information |
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 |
| |||||
| AMSTERDAM/ Schiphol EHAM | Half-hourly | METAR MTI VWS TREND 1) 4) RWY state message |
| H24 | AVBL5) |
| GRONINGEN/ Eelde EHGG | Half-hourly | AUTO METAR TREND 1) 2) RWY state message |
| 6) | AVBL5) |
| MAASTRICHT/ Maastricht Aachen EHBK | Half-hourly | AUTO METAR TREND 1) 3) RWY state message |
| 6) | AVBL5) |
| ROTTERDAM/ Rotterdam EHRD | Half-hourly | AUTO METAR TREND 1) 4) RWY state message |
| 6) | AVBL5) |
3.1 Observing systems and operating procedures
Surface wind speed is measured by cup anemometers and wind direction by wind vanes at 33 ft/10 m above ground.
The unit knot (KT) is used to indicate surface wind speeds.
Reported visibility is lowest visibility. In METAR, TREND and TAF prevailing visibility is also available.
Runway visual range (RVR) assessments are made by using forward scattermeters. Forward scattermeters measure the back scatter of the atmosphere in terms of a back scatter factor for a distinct volume of air. The back scatter factor is converted to runway visual range taking into account background luminance and intensity of runway lights. The forward scattermeters are calibrated using a standard transmissometer set. The background luminance is determined by measurements; the intensity setting of the runway lights is assumed to be 100 percent.
The reporting scale consists of increments of 25 m for RVR up to 400 m, increments of 50 m for RVR from 400 m up to 800 m and increments of 100 m for RVR above 800 m. For all main landing runways at AMSTERDAM/Schiphol RVR readings from three locations along the runway are available. For each landing (take-off) runway the RVR values are designated A, B and C in accordance with the direction of landing (take-off). RVR values are provided in alphabetical order; A for touchdown and take-off area (TDZ), B for the midpoint (MID) and C for the stop-end or lift-off area of the runway (END). For RWY 18R the A reflects the TDZ reading, the B reflects the MID and C reflects the END area of the runway (TDZ east and TDZ west will be compared and the lowest value shall be the TDZ reading, MID 1 and MID 2 will be compared and the lowest value shall be the MID reading).
Remote reading thermometers (thermistors) are used to measure the air temperature at 5 ft/1.50 m above the ground. Height of cloud base and cloud cover are obtained by measurement (ceilometers) and at AMSTERDAM/Schiphol also by visual estimation. The instruments are located in such way as to obtain observations that are representative for the take-off and landing areas (see paragraph 3).
4 TYPES OF SERVICE
MWO-De Bilt provides landing forecasts, aerodrome forecasts, forecasts for take-off and aerodrome warnings. Briefing and consultation may be obtained on request (after self-briefing) from MWO-De Bilt (all flights).
The meteorological office at the international airport AMSTERDAM/Schiphol only provides the required meteorological information for AMSTERDAM/Schiphol (routine and special observations).
Particulars of the aeronautical meteorological offices and the meteorological information available are given in GEN 3.5, paragraph 3 and 7 and in Part 3 - Aerodromes, AD 2.11.
4.1 Information for pre-flight planning
4.1.1 Aerodromes with a self-briefing unit
Meteorological information for flights from aerodromes in the Netherlands where meteorological self-briefing units are established (AMSTERDAM/Schiphol, EINDHOVEN/Eindhoven, GRONINGEN/Eelde, MAASTRICHT/Maastricht Aachen and ROTTERDAM/Rotterdam) will be supplied to operators and flight crew according to the following:
Domestic flights
- Self-briefing with GLLFC (see paragraph 4.2.2), aerodrome reports and/or aerodrome forecasts for aerodrome of departure, destination and alternates.
- Briefing and consultation (on request) from MWO-De Bilt (see AD 2.11 for telephone numbers).
International flights
- Self-briefing with:
- significant weather chart (SWC)
- prognostic upper air charts
- aerodrome reports and/or aerodrome forecasts for aerodrome of departure, destination and alternates.
- Briefing and consultation (on request) from MWO-De Bilt (see AD 2.11 for telephone numbers). In order to compile data and prepare further analysis, briefing requests should preferably be done at least 1 HR prior to requested briefing time.
4.1.2 Aerodromes without a self-briefing unit
For flights from aerodromes in the Netherlands where no self-briefing unit is located, the required meteorological information shall initially be obtained from the internet (see paragraph 9.1), or by using 'Teletekst' (paragraph 9.2). Consultation with MWO-De Bilt by telephone is advisable when reduced conditions are expected along any route to be flown:
| Tel: 0900 202 3341 | Briefing low level flights (IFR/VFR). |
| Tel: 0900 202 3343 | Briefing IFR flights above FL 100. |
| Tel: 0900 202 3340 | Briefing balloon flights within Amsterdam FIR. |
4.2 Meteorological information for general aviation
4.2.1 General
Pre-flight planning shall always be started by collecting the required meteorological information (see paragraph 9). When a flight has been delayed, or when a long interval occurs between pre-flight planning and departure, it should be checked that the meteorological data used for the planning is still valid.
Especially when weather conditions are marginal, or when details of the forecasted flight conditions are doubtful, the pilot shall contact MWO De Bilt as close to the departure time as possible.
For flights from locations outside the Netherlands the necessary briefing and consultation shall be obtained from the national Air Navigation Service Provider for aeronautical meteorological information in the state of departure. Details of these services can be found in the respective AIPs.
4.2.2 GA forecast: graphical low level forecast (GLLFC)
For the entire FIR, including North Sea area Amsterdam and North Sea area V, a GLLFC is produced and made available on the website: www.aviationweather.nl (see paragraph 9).
The validity periods are 03-12 UTC, 09-18 UTC and 15-24 UTC. The GLLFC is available approximately one hour before the start of the validity period.
The GLLFC will be amended when significant changes occur or are forecast.
4.2.3 GA forecast: weerbulletin (Dutch only)
A weather bulletin (text, Dutch only) covering the Amsterdam FIR land area up to FL 100 will be produced and made available on the website: www.aviationweather.nl (see paragraph 9).
The weather bulletin will be amended when significant changes occur or are forecast.
4.2.4 GA forecast: North Sea Area Forecast (NAF)
A NAF contains a forecast of the predominant weather in a specific area over the North Sea. The NAF area in the forecast is identified by the ICAO 4-letter location indicator of the offshore platform on which the automatic weather station is installed.
NAFs are published daily 0600-2000 (0500-1900). During this period a minimum of 5 NAFs is published per NAF area. This number can change during the forecast period. NAFs are valid for a 9-hour period and are scheduled every three hours. A NAF has the same layout out as a TAF, but has an additional remark field (RMK) that can be used to describe local weather in the NAF area in abbreviated plain language. The NAF contains more detailed information than the graphical low level forecast (GLLFC). |  |
4.2.5 Meteorological pre-flight planning
At the airports AMSTERDAM/Schiphol, EINDHOVEN/Eindhoven, GRONINGEN/Eelde, MAASTRICHT/Maastricht Aachen and ROTTERDAM/Rotterdam detailed information for pre-flight planning will be provided by self-briefing. Briefing by telephone (after self-briefing) can be obtained from MWO-De Bilt (see paragraph 4.1.1 and 4.1.2).
4.2.6 Special meteorological warnings for flights below FL 100
An AIRMET will be issued by MWO-De Bilt when a sudden deterioration in the meteorological conditions occurs, that could endanger the safety of flights below FL 100, also those conducted by visual reference to the ground.
AIRMETs are broadcasted or supplied by direct transmission to aircraft in flight by the Flight Information Centre Amsterdam (callsign 'Amsterdam Information' on 119.175, 124.300 and 136.650). These warnings are provided in the English language and will be identified as 'AIRMET'.
5 NOTIFICATION REQUIRED FROM OPERATORS
Normally meteorological information and flight documentation will be available for non-regular flights, when notification has been received at least 1 hour prior to the expected time of briefing. Notification shall comprise the following:
- required aerodrome(s)
- expected time of departure
- planned route to be flown.
6 AIRCRAFT REPORTS
MWO-De Bilt should be informed as soon as possible through the appropriate ATS unit when the following weather phenomena are encountered during the climb-out, en route or approach phases of the flight:
- severe icing
- moderate and severe turbulence
- hail and/or thunderstorms, if not previously forecasted
- strong low level windshear
- other hazardous phenomena markedly deviating from the forecasted weather.
7 VOLMET SERVICE
| Name of station | CALL SIGN Identification (EM) | Channel | Broadcast period | Hours of service | Aerodromes | Contents & format of REP and FCST | Remarks |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| AMSTERDAM | Amsterdam MET Broadcast (A3E) | 126.200 | H24 | CONS | Amsterdam | MET report & QNH & TREND 1) | Weather reports may be obtained on request on the ATC FREQs.
|
| Rotterdam | MET report & TREND 1) | ||||||
| Brussels | MET report & TREND 1) | ||||||
| Düsseldorf | MET report & TREND 1) | ||||||
| Paris/Charles de Gaulle | MET report & TREND 1) | ||||||
| London/Heathrow | MET report & TREND 1) | ||||||
| London/Gatwick | MET report & TREND 1) | ||||||
| Copenhagen | MET report & TREND 1) | ||||||
| Hamburg | MET report & TREND 1) |
8 SIGMET SERVICE
A meteorological warning (SIGMET) will be issued by MWO-De Bilt when the following weather phenomena are occurring, or expected to occur, in the Amsterdam FIR:
- obscured or embedded thunderstorms (with or without heavy hail)
- frequent thunderstorms (with or without heavy hail)
- thunderstorms in squall line (with or without heavy hail)
- severe turbulence
- severe icing
- freezing rain
- volcanic ash
- radioactive cloud.
SIGMET messages are relayed to aircraft in flight by the appropriate ATS units.
9 OTHER AUTOMATED METEOROLOGICAL SERVICES
9.1 Internet
A dedicated web site (www.aviationweather.nl) is available, requiring username and password. These can be obtained from the following user organisations: KNVvL, AOPA Netherlands, PBN and VNV (Dutch ALPA). Professional users residing in the Netherlands may contact KNMI (preferably through their employer) on aviation@knmi.nl.
This website contains the following information:
- OPMET
- Weather RADAR
- Satellite
- SIGWX
- UWT
- Surface (EUR)
- Time series
- Temp profile.
9.2 Teletekst
For low level flights (including VFR) over the Netherlands, MWO-De Bilt issues daily 5 or 6 weather bulletins in Dutch, with (AUTO)METARs of various reporting stations in the Netherlands.
The weather bulletins are made available via the Dutch public television 'Teletekst', page 707.
The bulletin contains a concise description of the most important weather systems affecting flight conditions over the Netherlands and information about the following elements:
- significant weather (incl. icing and turbulence, except if occurring in convective clouds)
- clouds
- thermals
- height of the zero degree Celsius level if lower than 10 000 ft
- surface wind
- upper winds and temperatures at 500, 1500, 3000, 5000 and 10 000 ft.
An amended weather bulletin will be issued if significant changes in the weather conditions occur.