Aviation Weather Center routinely provides a Mid Level Significant Weather chart, between FL100 and FL450, for the North Atlantic Ocean Region (NAT). The NAT chart implementation is scheduled for Sept 15, 2003 with 0600Z forecast.
The presentation of significant weather on the mid level significant weather chart is similar in many respects to that on High Level Significant Weather charts. The detail required however is more extensive because the bottom of the chart is now at FL100 instead of FL250. Aircraft flying at these lower levels in the atmosphere, below FL250, will more likely encounter larger areas of icing and turbulence.
The North Atlantic Mid Level Significant Weather chart will be transmitted along with the High Level Significant Weather charts. Transmission times for forecast packages are:
|24 hour forecast package valid at 00Z||08Z|
|24 hour forecast package valid at 06Z||14Z|
|24 hour forecast package valid at 12Z||20Z|
|24 hour forecast package valid at 18Z||02Z|
The information placed on the Mid Level Significant Weather chart will be the combination of information imported from the corresponding High Level Significant Weather chart and additional information generated by the meteorologist specifically for the Mid Level chart.
This document has been prepared by the World Area Forecast Centres (WAFCs) for the purpose of providing guidance to software developers who have the task of constructing WAFS SIGWX BUFR visualisation software. The document is designed to assist developers in the construction of compliant visualisation software that receives its data input from text files obtained from BUFR decoding software.