Apart from weather.com and it's affilaites, are there any good websites for long range forecast for Portugal, Algarve area?
There is no such thing as a long range forecast that predicts weather anywhere 2 weeks out.
It can only be vague and theres no science to it as the nwp's even are only accurate to about 72 hrs and a shaky guideline past 72hrs up to about 5 days.
Beyond 5 days use the tea leaves to be honest or common sense on the basics.
Heres my stab at it anyway given that nwp's are no good for this type of thing.
It will be warm to hot every day with sea breezes.
There may be afternoon showers or thunderstorms mainly inland.
Repeat to the end of the summer as a general guide.It is possible that the odd low pressure system may come in off the atlantic that far south but theres no way to tell more than a week ahead of the event.