They’re all model derived unlike the snow clowns. They’re ok, but they’re a product of the synoptics. At this range it’s a crapshoot. I find they tend to be overly pessimistic with the OVC and optimistic with the SKC..ie more SCT/BKN than depicted. If you’re under a storm or a big high, obviously confidence goes up. Dirty ridging, convection, mesoscale nuances, etc and the error goes up. The euro has them as well…free on weather.us