Is the word nuvens the same in Brazilian and European Portuguese?

Yes

The word nuvens is identical in spelling, meaning, and grammar in both Brazilian and Continental Portuguese. The only differences are found in pronunciation:

• Vowel Reduction: In Brazilian Portuguese, the unstressed "e" is usually more audible and open. In Continental Portuguese, unstressed vowels are often highly reduced or almost silent, making the word sound more like "nuvns."
• Sibilance: In most Brazilian dialects, the final "s" is pronounced as a soft [s]. In Portugal, the final "s" is typically pronounced as a "sh" sound [ʃ].

Brazilian Portuguese Examples:

1. As nuvens estão muito brancas hoje. (The clouds are very white today.)
2. Olha para aquelas nuvens escuras! (Look at those dark clouds!)
3. As nuvens estão passando rápido. (The clouds are passing by quickly.)
4. Tem muitas nuvens no céu. (There are many clouds in the sky.)
5. As nuvens cobriram o sol. (The clouds covered the sun.)

Continental Portuguese Examples:

1. As nuvens estão muito brancas hoje. (The clouds are very white today.)
2. Vê aquelas nuvens escuras! (Look at those dark clouds!)
3. As nuvens estão a passar rapidamente. (The clouds are passing by quickly.)
4. Há muitas nuvens no céu. (There are many clouds in the sky.)
5. As nuvens taparam o sol. (The clouds covered the sun.)