I think it varys a lot without a lot of easy to discern pattern.
If its an issue of a stabilized "high" (Bermuda high, with winds from the south), then I think that there is often a better situation for the afternoon being a bit better -- but it varies depending on how early you mean when you say morning. (You don't mean at 6:00 - 9:30 AM?)
Otherwise, I think that the afternoon is usually better. The T-Storms can be an issue, but usually not that big a deal unless you try to "get-in" to a slip in the middle of a blow when you should stay out.
Frankly, so far this year, we've not had that much really strong wind
. (Except for the monsoon of a while ago, when we got a ten days of HEAVY rain.)