What is a typical range for tropospheric duct propagation of microwave signals?

Tropospheric ducting occurs when a temperature inversion creates a specialized 'duct' in the lower atmosphere. This duct traps VHF, UHF, and microwave signals, bending them along the curvature of the Earth rather than letting them escape into space. While exceptional tropospheric openings can sometimes stretch across oceans, the typical, everyday working range for microwave ducting is between 100 and 300 miles. This provides a significant boost over standard line-of-sight propagation. Distances of 1,200 to 2,500 miles are characteristic of HF skywave propagation bouncing off the higher ionospheric layers (like the F layer), not the weather-dependent troposphere.