5 km was controlling for initiating the approach. We never could get an answer from FAA or anybody how they report multiple visibilities in different directions and what was controlling. In the US it is prevailing visibility controlling approach legality which means over half of the directions visibility is 5 km. We would have and have in the past initiated the approach with 2,000 broken conditions as long as we had 5 km reported in at least one direction. TGU had certain landmarks they used to determine visibility but they did not have anything to do with prevailing visibility. The cloud bases were not controlling. You just couldn't continue to a landing unless you had the airport visually in sight reaching MDA.
The only time I couldn't land there and ended up at San Pedro Sula the ceiling was 2300 overcast and never saw the ground. Noone landed that day because of the weather. That day they would not allow any 02 approaches to get below 2700 ft AGL. I complained so the next day they notamed all 02 approaches OTS. My complaint was if they publish an approach they should let you perform it.