Gotta love all the great info you get on Frank's BS (Bay Store) Outdoor Reports forum. Here's my hackers 2 cents worth.

Predictability is always a tough subject. But... In the early part of the year it goes without saying that for the most part, weeds play probably the most important role in finding fish.
When it comes to weeds one thing I notice that does come into play quite a bit and varies from year to year, spot to spot, hour by hour is how current effects them. Not only where the weeds are growing and how fast, but what they're like under the surface. How you'll fish a spot and notice the weeds that were so thick and up near the surface last night you could barely get through them with your 300# of thrust trolling mtr, yet this AM they are now lying down so much you don't even know they are there.

The problem is there are so many things that effect current. The weather, not only where you are but several miles away. Wind direction, and even wether or not they're letting in or out water, etc. etc. I hate to admit it but Dick's right. Probably one of the best ways to predict current is "Syzygy".