Personally I think that it would be foolish for anyone to think that they can accurately make weather predictions using OPC charts and gribs alone (no offense Auspicious, just my opinion) on a trip of more than 3 days across an ocean.
No offense taken at all. I fear that my suggestion was not sufficiently clear.
First, gribs are bad. Although US NOAA/NWS is working on it, they don't show fronts or major weather artifacts, where bad things happen. Don't get sucked in to technology. For the digit-heads I'll be happy to share the algorithms and where and why they break down.
OPC charts are good. HOWEVER, you can't launch offshore with a set of synoptics and expect to be okay. You should have the ability to receive weather faxes onboard every day. The full set are transmitted twice each day. If you already have a laptop you can be set up for $100US or less to receive weather fax on board. You should (my opinion) be able to look at a set of wefax and make good, responsible decisions about your tactical routing. You'll be looking at the same material that the weather routers are.
Herb Hilgenberg and Chris Parker do not have academic backgrounds in meteorology. If they can do it you can to. There are some challenges but you can do it, and you SHOULD. Be self-sufficient. Learn this stuff. If you are really sailing offshore your safety may depend on it. It's up to you.
The 3-day threshold is apt. I fully agree, and that defines my definition of sailing offshore. If you're 3 days from a bailout you are offshore. Less than that, you are coastal (or at least near-shore). Even US to Bermuda is offshore and you MUST (my opinion again) have a means to get weather information onboard. A router is better than nothing but cheaper AND better is getting the NWS or UK Met products onto the boat and making your own decisions.