We often use "wish + that clause" to express a past/present counterfactual statement or a future unlikely event (i.e. remote possibility):
I wish I hadn't quit my job. (But I quit my job.)
I wish I had two million dollars. (But I don't.)
I wish I wouldn't have to work tomorrow. (But I have to. I will be working tomorrow.)
My question is, is it possible to use wish + that clause to express open possibilities for the future?
Note: Open possibility/condition means the fulfillment of the event is not determined but there is a chance of it happening, as opposed to remote possibility/condition, where the speaker knows that the chance of occurrence is remote/unlikely.
For example:
(?) I wish the weather would be nice this weekend. [future time reference]
(Intended gloss: I really don't know
what the weather will be like this weekend, and I haven't checked the
weather forecast, but I hope it will be nice.)
I tried to find the answer from the web and in a few grammar books. The only answers I got so far are negative. But the sentence above, about the weather, seems rather natural to me. I even found this example sentence from a grammar book, but the book doesn't say whether it carries the connotation of unlikelihood:
I wish the weather would get better. I am tired of being inside all
the time.
To me, that sentence simply expresses the hope that the weather will clear up, i.e. an open possibility.
Best Answer
"Wish" is used to express regret and that something isn't as you would like it to be.
Even the example that you found in the book:
implies that the speaker would like it to be, but the speaker doesn't expect this to happen.
Especially,
tells us that the speaker wants something to change, but it is unlikely to happen.
There is one instance though when the use of "wish" can mean "open possibility," to borrow the OP's words.
But you cannot wish that something happens. You still need to use "hope":