To obtain the full text of WMO - Technical Note No. 203 (now often archived in national meteorological libraries or university earth science departments) is to hold the blueprint of the heavens in your hands.
Disclaimer: This article is a scholarly interpretation of WMO Technical Note No. 203 (1984). Always consult current aviation weather warnings and local regulations before attempting soaring flight. To obtain the full text of WMO - Technical Note No
Specifically for ridge running. A 30-degree wind shift between ridge height and 500m above can create violent rotors. The note recommends aborting the forecast if the Wind Shear Factor exceeds 0.2 (20% change over 500m). 203 (1984)
The "jet fuel" of soaring. Standing atmospheric waves downwind of mountains, allowing altitudes above 30,000 feet. A 30-degree wind shift between ridge height and
Wave soaring allows pilots to reach stratospheric altitudes (records exceed 50,000 feet), but it is fraught with danger. TN-203 outlines the prerequisites for wave formation:
Note No. 203 is not just theory; it is a manual. It outlines a step-by-step methodology for the operational forecaster working with limited data (pre-internet era, yet still valid).