WS can easily pop up with no forecast. Sounds like circumstances to me.

Landing at a non-121/OPSPEC airport is not inherently dangerous if you have the required length and width of runway for the conditions. Big difference is that it may not have ARFF on-site but odds are low that you'll need them.

If a particular airline made a habit of this sort of thing, then there might something wrong with their dispatch process, ie skimping on fuel to save money.