But the authorities warned the public not to believe some social media messages that have gone around specifying times when various weather warning signs will go up.
The Observatory said it does not issue such alerts and urged the public not to rely on such information.
Airlines based in Hong Kong meanwhile, have issued a warning that the storm may severely disrupt flights on Friday and Saturday.
Cathay Pacific, Dragonair and Hong Kong airlines have urged passengers booked to fly on these days to check the status of their flights before heading to the airport.
Haima caused flooding, landslides and power outages in the northern Philippines. At least 8 people were killed, but large-scale casualties appeared to have been averted after nearly 100,000 people were moved to safer ground.