Hi Debbie and Rick,
I'd suggest first step is to be able to intepret a weather map. Its not so hard to judge what you are looking at, you'll leanr that from courses and books, but trying to predict how that current weather map will develop for tomorrow and the day after etc is a magic art. Just recall how often a land based TV 'expert' gets it wrong in your home town, and you'll appreciate how tricky it can be.
Suggest next step is learning how to interpret what you see and feel around you. How to read a barometer, the sky, the seaweed. As well as all the old sailors tales, what you see will help you interpret how the weather pattern is progessing, in turn making your predictions more accurate. Again, lots can be gained from books, but a lot more can be gained by experiencing it all whilst at sea.
Just about everyone can get a simple weather forecast.
These are predictions from others who have interpreted the weather maps, and pass it over in a condensed form.
A Navtex is the most common device over this side of the world to recieve both weather forecasts and sea safety bulletins.
EU countries have multiple Navtex stations, some who forecast fairly accurately, and some who get it horribly wrong. Guess they get those forecasts from their local weather men.
You'll also be able pick up weather forecasts close to shore as currently issued by coastal station on VHF. Also from regular radio channels, either commercial shipping forecasts or simply local coastal forecasts. These of course when overseas, are not always in English!
I have absolutely no idea if the subscription radio satellite stations like you mention give weather forecasts. I would have assumed they transmit over such a wide footprint they'd have to be on air with weather 24/7 to do this well.
Also never heard of a facility where they can transmit and you can recieve weather maps.
Somehow I doubt the latter but if someone has told you they can download files to overlay onto a chartplotter - guess you'd better ask them for more info on how.
So essentially - coastal work and you can use forecasts. Offshore - you really need to get and read weather maps.
You could pick yp forecasts for short trips before you depart. They usually show predictions for two / four days ahead.
You could also get them off the web where there are lots of weather forecasting sites - go see www.weatheronline.com
You can indeed download what are called GRIB files (weather files) which can be overlaid onto chart plotting devices so end up only having to look at one screen. But with GRIB displayed, most end up pretty cluttered.
Or if a long way offshore, you can get weather maps via an INMARSAT system, or via a modem attached with your computer and to a HF radio. You could also web access via your computer and a sat phone connection. That is all pretty expensive kit, so you do need to know you'll get value (ie use it) before investing.
Hope this helps you out.
If an expert out there thinks I've missed anything or wishes to correct me for US waters, then guys, please listen to them.