There is more RF noise on the VHF bands, especially the low VHF band (channels 2 through 6).
However, in your situation, there are two stations transmitting on channel 12, WKRC and WYMT. The GS1100 has little if any ability reject the signal from WYMT when it is aimed to receive WKRC. It has a front to back ratio of virtually 0 dB.
A Winegard
YA-1713 or an Antennacraft
Y10713 would have much better forward gain and rejection of signals from the rear. Your TVF report predicts a noise margin of 5.1 dB for WKRC, add the 10.0 dB forward gain of the YA1713 and you are at 15dB NM... that's pretty good if there was no co-channel interference. The predicted receive power for WKRC is -85.8 dBm vs. -103.2 dBm for WYMT, a difference of 17.4 dB. Given the published F/B ratio of the YA1713, I expect the YA1713 should provide you with a difference of 36 dB between the desired signal and the interfering signal.
If you really want to see WKRC... the YA-1713 should do the job. For situations were even more rejection of signals from the rear is needed,
stagger stacking is a useful technique.