Forecast Bulletins

Forecast Bulletins: Bulletins with weather forecasts and warnings for the FIR in plain language :

General forecast

The General Forecast is a bulletin with a general weather prediction that is drawn up twice a day. The bulletin describes the synoptic situation and gives a forecast for wind, weather, visibility, clouds, the height of the 0° level, minimum QNH, soaring capabilities and in conclusion the minimum and maximum temperature. This forecast also comprises a section "Warnings" that, if the circumstances require it, draw special attention to well-defined phenomena that can be hazardous to flight activities at lower levels. The section "Outlook" is valid for a minimum period of +12 hours.


Issue time Validity Period Outlook
05.30 Z 06-18 Z + 12 h minimum
17.30 Z 18-06 Z + 12 h minimum

General Warning

The General Warning is drawn up and distributed when one or more of the following phenomena occur and when these are not included in the "Warnings" part of the General Forecast in force at that moment.

- Ice deposit with intensity details (MOD or SEV), position and level
- Turbulence with intensity details (MOD of SEV), position and level
- Strong wind, i.e. minimum 30 knots at average and/or 40 knots squalls
- Heavy showers or thunderstorms
- Snowfall or melting of snow within 24 hours
- Night frost or continuous frost
- Temporary or definitive thaw
- Black ice
- Mist or very low stratus

Medium range bulletin

The "Medium Range Bulletin" is a meteorological forecast product. It is written in English and gives, amongst others, a short description of the evolution of the synoptic situation and the expected frontal zones, trough line and the development of areas of atmospheric pressure for the four following days. This "meteorological" description is also "translated" to a more "understandable weather picture" with a general forecast containing information about wind, maximum and minimum temperatures, precipitation and cloud cover.

The "Medium Range Bulletin" is updated daily around midnight. You can find this bulletin in AIS Meteo Briefing, on the Meteo information pages, under the tab "Forecast Bulletins".

Ballooning Bulletin

The Ballooning Bulletin is a forecast bulletin in plain language containing specific meteorological information destined for ballooning activities in Belgium: expected surface and upper-air wind, temperature inversions and an outlook. This local forecast bulletin is issued according to the following time table:


Issue time Validity Period Outlook
02.30 Z (*) 1H before and 2H after Sunrise 12.00 Z - Sunset
05.30 Z (**) 1H before and 2H after Sunrise 12.00 Z - Sunset
10.30 Z 2H before and 1H after Sunset Next day
15.00 Z (update) (*) 2H before and 1H after Sunset Next day

(*) Summertime period
(**) Wintertime period