Weather for business

Improved icing and turbulence hazard forecasts in medium level SIGWX charts

 MetService is providing airlines with improved icing and turbulence hazard forecasts in its aviation significant weather (SIGWX) charts.

The new charts provide airlines with forecasts of the location and severity of icing and turbulence using a new hazard datasets issued by World Area Forecast Centres (WAFCs) in the USA and UK. The changes result in the SIGWX charts now in full-colour to aid usability.

Aircraft icing is a serious aviation hazard. The possible range of effects on an aircraft include a reduction in aerodynamic and flight performance, an increase in weight, and in severe icing situations, a loss of control.

The new icing and turbulence hazard forecasts will contribute to enhanced safety by allowing airlines to use this information during flight planning to assess the risk of icing and turbulence to aircraft flying domestic and international routes in much greater detail than before.

 

To following link has examples and more details behind the SIGWX changes.

 

What’s changed:

Chart presentation

  • SIGWX charts provided in full-colour

Three versions of medium level charts to cater for a range of user requirements

  • Medium level SIGWX -– showing significant weather, icing and turbulence on a single chart

  • Medium level SIGWX – CB & Icing

  • Medium level Turbulence

Icing hazard areas

  • New icing index data provided as part of the medium level SIGWX. 

  • Severity of the icing is indicated as moderate or severe (with the ‘worst in layer’ conditions represented on the chart).

Turbulence hazard areas

  • New turbulence hazard forecast data provided as part of the medium-level SIGWX chart.

  • Severity of the turbulence is indicated as moderate or severe (with the ‘worst in layer’ conditions represented on the chart).

     

Labelling of phenomena heights

  • Medium-level SIGWX charts will only show heights for phenomena between FL100 (10,000ft) and FL250 (25,000ft). Phenomena that extend below FL100 or above FL250 (eg cumulonimbus clouds) will be labelled on the chart with XXX for the lower or upper level indicating that it extends beyond the levels of the chart.

  • High-level SIGWX charts will only show heights for phenomena between FL250 and FL630, with phenomena extending below FL250 labelled with XXX for the lower level.

 Isolated cumulonimbus clouds (ISOL CBs)

  • Following user consultation, and due to advances in the technological capabilities of on-board weather radar, ISOL CBs will no longer be included in SIGWX charts.

MetService will continue to issue SIGWX charts every six hours (00, 06, 12, 18).  In addition to the new icing and turbulence hazard areas, SIGWX charts will continue to show other phenomena including: embedded cumulonimbus clouds, jet stream locations and heights, volcanic eruptions, tropical cyclones, radioactive events, widespread dust and sandstorms, and the flight level of the tropopause.

 

Need more information?


For further technical information, and examples of the SIGWX changes, please read the Changes to Aviation Significant Weather Charts document.

Alternatively, please contact our aviation sales team.