Also I think you need 4 hourly obs to get the 3 hours inclusive...not sure. BDR is manned today too, but I’m not sure if they augment vis obs.
Maybe @OceanStWx knows how GYX goes about verifying it.
Criteria has always been under 1/4SM. But with automated ASOS sites without augmentation it’s damn near impossible to get obs of M1/4SM. A lot of the old manned 0SM, 1/16SM, and 1/8SM obs are seen as 1/4SM by the ASOS now.
The CMC suite has been pretty consistent with that and it’s interesting how some of the other models try to regenerate the low down there now. I guess we’ll see, but you have to think the canadians are overdoing it.