For GA flying, 24 hours in advance I tend to use the forecast to either say, definitely dont go, or it may be OK, so keep planning.
Then on the day itself I can make a reasonably informed decision. Very early starts are difficult though because you may find not enough METARS are available to tell you if things are actually doing what the forecast says.
Sounds like you're planning a flight for a business meeting? Tempting to fly. But maybe not such a great idea because it introduces pressures and constraints that you could do without. Once flew with a very experienced ATPL holder to a meeting, and we spent the whole time looking out the widow at the worsening weather, not giving the meeting our full attention. Needless to say we didnt get the sale.