No, UHF (GMRS frequencies) do not 'skip' like HF (CB frequencies) does.
What you can experience occasionally is tropospheric ducting where a warm air mass gets in overtop a code air mass and creates a tunnel for VHF and UHF frequencies to travel in far beyond normal line of site. This is NOT a common occurence however and shouldn't be relied upon for consistent communications the way it is with HF communications. HF 'skip' is caused by the RF reflecting off the Ionosphere and back down to the ground where it's then reflected back up again, over and over until the path loss of the signal becomes too great for a receiver to hear it.
With ducting, the greatest path distance that can exist only extend slightly past the area covered by the air mass inversion since frequencies above 50 Mhz typically do NOT reflect off either the ground or the ionosphere.
VHF and UHF frequencies also do not have any 'ground wave' propagation like the lower HF and VHF frequencies do. Ground wave is a phenomenon where the RF wave 'hugs' the ground and carries long distances past normal line of site (past the curvature of the earth) by staying on the ground. This only works below 5 Mhz or so in frequency.
There are several web sites and books including the ARRL Amateur Radio Handbook that discuss the propagation of different RF frequencies at length and might be a good source for a better and more detailed explanation than a half away guy posting at 4 in the morning while half awake.
If safe (always like to throw that in there), try taking your hand held up on the roof and see if that improves your position enough. You may get an idea if it’s worth putting an antenna up. Also if you know where the repeater is you can get an idea of line if site using a tool like this.
WRYG609 reacted to WRKC935 in Skip like CB?
