I use Winlink 2000 (WL2K) & Airmail 3.8 and my HAM radio/Pactor III modem and get all the same GRIB data for free. Airmail has a good grib viewer that is a standard part of the package. There is also a very easy to use GRIB request generator that allows you to graphically select the area of interest and to control all the time and size parameters. The system can be setup to automatically send you a new GRIB file or set of files on any time interval you wish. FREE!!

You need a General or Extra class HAM license for WL2K but the same software and GRIB services are available through Sailmail which uses non-licensed SSB frequencies.

I looked at the "for pay" weather services before I made this years trip from Seattle to San Diego and found nothing in the "for pay" service that was not available for free from WL2K/Airmail.

I downloaded COAMPS GRIB files every six hours while making the San Diego trip. Those GRIB files generated by the COAMPS model can provide a unique wind estimate for each 14 mile square block (0.2 degrees) in your area of interest. COAMPS was developed and is used by the US Navy for planning inshore maneuvers and landings and takes into account headlands, capes, and shorelines. Once 30 miles offshore I use the standard GFS model for my GRIB data. FREE!!