UKH

What do people use for a reliable weather report in the Pyrenees? Visiting the Vignemale region for a couple of weeks.

https://meteofrance.com/meteo-montagne/pyrenees and pick a location, e.g. https://meteofrance.com/meteo-montagne/gavarnie-gedre/651881

Rainfall radar: https://meteofrance.com/images-radar

https://www.mountain-forecast.com/peaks/Vignemale/forecasts/3298 and https://www.yr.no/nb/v%C3%A6rvarsel/daglig-tabell/2-6440733/Frankrike/Langu... also worth a look, but I would generally expect better accuracy from Meteo-France. 

Locally (southern French Alps) I find https://www.meteoblue.com/ pretty good & usually better than Meteo France so might be worth trying elsewhere in France. 

I agree about Meteoblue, but my current favourite site is windy.com, as it allows you to compare forecasts from each of the major weather models. Having a range of 5 independent forecasts is really helpful in deciding how much confidence to have in an outcome.

not heard of that site before, looks interesting

As above - Windy.

you can compare and contrast the different models and it doesn't take long to work out what each one is optimised for, and where each is going to be more accurate.  You can then either interpret the collected forecasts, believe one, or just take the one that's offering the best weather......It all depends on how keen you are on your chosen objective

PS - the models are the ones that the various other sites are based on