TAIPEI (Taiwan News) — Tropical Storm Koinu is likely to intensify and impact Taiwan the most between Wednesday (Oct. 4) and Friday (Oct. 6), according to one meteorologist.

National Central University professor Wu Der-rong (吳德榮) said the storm will intensify to become a moderate typhoon by Tuesday, after which it will possibly pass Taiwan’s south, per CNA. However, Wu said there is still great uncertainty about what path the storm will take.

Wu said there is a higher chance of the storm moving westward past Taiwan’s south coast. There is a smaller chance it will move north and away from Taiwan to the east, he said.

Wu said the impact of the storm will depend on exactly when it comes and what path it takes. He said that the latest models show localized rain will begin on Oct. 3, and on Oct. 4, heavy rain will begin in Taiwan’s north and east, with localized rain in the west.

Heavy rain is expected to continue until Oct. 7 in some places, Wu said.