Small boat - Merryfisher 625, I dont think so!!! Depends what you are comparing it with!!!
We had Free Boys come over to Alderney in some snotty weather and I think she is a Merryfisher 600 Marlin.
Like Charlie says, we cant tell you whether it will be ok - that is your call and your call alone being the skipper.
However, on that forecast I would probably take my boat, don't be afraid to get to the harbour entrance and turn back! Also, it can be worse in the harbour than it is outside, though that is the exception rather than the rule!
Use Easy tide for online prediction of tides and look at the chart, there is also a tide chart book for Poole available, I find that excellent and it shows the double IOW tides we get.
hth
Rob