Fed up with weather !

[svenks]

that the bad weather stays the same untill you reach ur port and exit the patrol

It is the infamous "no weather change for a long time after reload" bug, combined with the way we use this game.
Consider: You leave port in good wx. You sail to your patrol area or whereever using TC. Lots of virtual time passes, little real time and you don't save.
You reach your destination, and the wx may have turned bad now. But here you spend a lot of your time without TC, listening for and sinking targets - and a lot of real time passes and you have to Save and Exit for real life 'duties'. And when you reload, wx will be 'stuck' for what seems a long time!
Finally you run out of torps (or patience) and head for home, using TC. Now, the wx has many virtual days to change, and it will probably do so... And so you enter port at 5m/s and clear skies.
A workaround is of course to save and reload when the wx is OK. If you keep doing that, you'll always have clear skies - but it would be cheating (in my book, anyway )

BRGDS
Sven