Skumring covers both requests.
The Third And The Mortal, one of their influences, partly covers both requests - since one song on their debut EP "Sorrow" and two songs on their debut album "Tears Laid In Earth" have got Norwegian lyrics. Please note that while these two releases might be considered atmospheric doom metal, any album released afterwards isn't metal at all. (I like them nevertheless.)
word! the best female vocals out there
I second (or in this case "third") the recommendation of Madder Mortem.
other good bands with great female vocals:
Gåte
Rather folk rock than metal, but Gunnhild Sundli definitely has a clean and powerful voice. In addition to that, all songs are in Norwegian or, to be more precise, different Norwegian dialects.
Other bands with clean female vocals which come to my mind are:
Atrox (Monika Edvardsen-era; it should be added that some of the vocals are really crazy, though - the most moderate are those on "Orgasm")
The Gathering (If you're looking for metal only, try "Mandylion" and "Nighttime Birds"; anything released afterwards can't be considered "metal" anymore - still I like some of it better than "Mandylion" and "Nighttime Birds")
Midnattsol ("Where Twilight Dwells" and "Nordlys" both also feature two songs with Norwegian lyrics)
Dreams Of Sanity (a now defunct band who released 3 albums, out of which I think their debut "Komödia", which featured two female vocalists, is their best)