嘩唔好呀
Wow bad

Cantonese Sentence Breakdown

嘩 waa4
crashing sound
to gush forward
rushing sound
noisy
clamorous
clang
wow!
to shout
唔好 m4 hou2
(phrase) don't.
呀 haa1
(particle equivalent to 啊 after a vowel, expressing surprise or doubt)