I always looked at that as "I don't really know what the weather is going to like, but I am required to give you some kind of info"~!
In 2000 the wife and I, along with two other aircraft, were working our way south through Alberta, Canada. Weather was widespread low ceilings and rain, our progress had been slower by airplane than the year before when we drove the route. We were in Grand Praire and walked into the FSS and I asked for a VFB brief to Edmonton and points south….he replied "Fat chance!".
We did get out that day and made it to Lethbridge just after dark.
Another term is WOXOF….