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For the first time, SIGWX forecasts will be produced for multiple timesteps.  They will be rationalised into a single product spanning FL100 to FL600, and will be updated to a new IWXXM format

The  World Area Forecast Centres (WAFCs) are now able to start providing some test IWXXM format data sets and would like to encourage SADIS and WIFS users to try to visualise this data and provide us with feedback. 

The full IWXXM schema is available here  - please look in the most recent directory to find it.  The schema was approved in November 2021.


Important Information

From November 2023 only the current high level SIGWX chart areas for T+24 will be provided in BUFR and PNG format.  Therefore to take advantage of the new multi-timestep SIGWX forecasts users will need to be able to process and visualise the IWXXM SIGWX data sets.  

BUFR format SIGWX will be retired at the end of 2025, and the T+24 PNG charts will be retired in 2028.

By processing and visualising the IWXXM SIGWX data customised SIGWX charts can be created that more effectively meet the needs of users.  Different layers of data can be toggled on or off, displayed in colour, overlaid with other data (e.g. the flight route, or other meteorological data), and presented for any chosen map area and projection. 


New SIGWX Characteristics

Instead of having separate high and medium level SIGWX, from November 2023 only a single SIGWX spanning FL100 to FL600 will be produced.  

The way in which WAFS SIGWX will be visualised from will also be changing a little, and these changes can be viewed here.   


Test Data

IWXXM will be provided, along with sets of images that can be used to check your visualisations of the different SIGWX features. 

Please note that the images provided are not in their final form (e.g. labelling and colour schemes) but do provide the information that is needed for preliminary testing and using for visualisation comparisons.  Additional test data sets will be released periodically.


Feedback Required

The WAFCs, and the WMO team which developed the IWXXM schema are extremely interested in gaining feedback from users on how they visualise this new data. 

Any information on your visualisations, any challenges that were faced (and hopefully overcome), or useful hints and tips that might benefit other users can be e-mailed to the SADIS Manager

Test Data Sets

Date Files Notes
February 2022



Global Image

This IWXXM file contains one of example of each type of feature, as well as a marker for a volcano, tropical cyclone, nuclear incident and sandstorm.
October 2021



IWXXM Turbulence

IWXXM Tropopause

IWXXM Cumulonimbus


Global Jets Image

Global Icing Image

Global Turbulence Image

Global Tropopause Image

Global Cumulonimbus Image


Individual Area Images

Zip File Part One

Zip File Part Two

Zip File Part Three

24-hour forecast data is provided. 

The IWXXM data for each element making up the SIGWX chart is provided in separate files.  In future they will be combined into a single file.

Volcano, tropical cyclone and nuclear release information is not yet available. 

We are not 100% certain that the end vectors used on the jet stream objects are correct.  Feedback on this would be welcomed. 

    Further information will be posted here when available.


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