Can't give you a website for forecasts that far out, but I can tell you that the weather in that area of the Med at that time of year is highly variable. We spent 3 days in Rome last year in late Oct and it was very warm with pretty much clear skies. Weather in Livorno was warm with PM thunderstorms. Monte Carlo was very pleasant with temps in the 70s. Seas can also be very variable. I would recommend the layering approach and definitely bring an umbrella no matter what the forecast is. You shouldn't need any winter clothing; just sweater and light jacket type things.