Lentoennusteissa

Lentoennusteissa refers to the set of weather forecasts used in aviation to anticipate weather conditions along flight routes, at airports, and en route. They support flight planning, risk assessment, and operational decision making by airlines, airports, and pilots.

Typical products in lentoennusteissa include TAFs (terminal aerodrome forecasts for airports) and en route forecasts that project wind, temperature, cloud, precipitation, visibility, and significant weather phenomena. Observations such as METARs provide current conditions that complement forecasts. Additionally, forecasts for significant weather events are issued as SIGMETs or AIRMETs to alert about hazards along air routes. In civil aviation, these products are standardized by international aviation meteorology services and use WMO formats.

Forecasts are issued for various time horizons, from nowcasts of the next few hours to en route forecasts covering 6, 12, or 24 hours ahead; many products are updated every 1–6 hours. Forecasts are expressed in terms of flight levels or altitudes, and weather along a route is considered for planning safety margins, fuel efficiency, and airway routing.

In Finland, the Finnish Meteorological Institute (Ilmatieteen laitos) provides aviation weather forecasts, including TAFs for Finnish airports and en route forecast charts, which are used by air traffic control and operators. These services are also available internationally and support pilots and dispatchers worldwide.

Limitations include forecast uncertainty, particularly for convective weather and rapidly changing conditions. To mitigate risk, flight operations typically rely on multiple forecast sources, timely updates, and coordination with meteorological services and air traffic control.