great sensation; taking by storm; making a splash
Describes a person, work, or event that causes a huge stir and captivates the public, often in entertainment or sports.
Her debut work caused a great sensation.
The rookie player is taking the professional baseball world by storm.
旋風 alone means 'whirlwind' or a sudden, short-lived trend. 一大旋風 emphasizes a major, sweeping sensation.
大旋風 is a similar compound meaning 'great whirlwind' or 'big sensation', but 一大旋風 is more emphatic and idiomatic.
Compound of 一大 (いちだい, 'one big; a great') and 旋風 (せんぷう, 'whirlwind'), literally 'a great whirlwind', used figuratively for a sweeping sensation.