It should be the second one. When you omit the subject in this pattern, the speaker and/or addressee, as relevant, would normally be assumed. ".
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future332I see what you mean but isn't it clear that I'm talking about the weather for tomorrow? My point is that I would agree with you when the subject is unclear. In the weather case,I think both the speaker and the listener understand the subject."What are the chances of raining tonight?" is intelligible. It is clear what it is intended to mean. However,