Hail storm occurs in summer season due to the formation of clouds called ____?

Hail storm occurs in summer season due to the formation of clouds called ____?

اولے کا طوفان گرمیوں کے موسم میں بادلوں کی تشکیل کی وجہ سے آتا ہےاسے کیا کہا جاتا ہے؟
Explanation

Cumulonimbus  is a dense, towering vertical cloud, forming from water vapor carried by powerful upward air currents.