As a Meteorologist and a boater who has crossed the Atlantic twice on my own 42 ft bottom, I think Uricanejack and KC are both right.
There is no skill in a 10-day forecast over the middle of the ocean. In fact, I think probably 5 days is the max one could expect.
Simply put, a lot more effort is put into a forecast for the 100 million people living on the east coast USA than the ocean where nobody lives and even fewer are going to complain about a bad forecast.
In practice, I’ve found it best to just worry about my departure wx, a go, no go decision, but once underway, I don’t even listen to NOAA wx radio while in range because it makes no difference.
At my boat speed of 150 nm/day, lows ate moving 3 times my speed. Thus even a slight error in forecast can make a significant difference. And perfect forecasts don’t exist on the open ocean.