Chaba is on track to become a powerful typhoon and could threaten lives and property across the Ryukyu Islands and mainland Japan next week.
Chaba is churning in an environment conducive for potential strengthening. The system could become a typhoon early this weekend and the equivalent of a Category 2 hurricane by late Sunday.
Damaging winds, torrential rain and seas will increase around Chaba's center, posing dangers to shipping interests.
Residents of the Ryukyu Islands and southern mainland Japan need to prepare for the future typhoon to make a direct hit or pass dangerously close during the first half of next week.
Chaba is expected to strengthen into the equivalent of a Category 3 hurricane before threatening the Ryukyu Islands.
The Okinawa and Amami islands are at highest risk of being battered by destructive winds and flooding rainfall from Sunday night into Monday local time. Seas will become dangerously rough and pound the coastline which may cause severe flooding, especially north and east of Chaba's center.
If Chaba makes a direct hit on any one of these islands, extensive wind damage and prolonged power outages are likely to result. Residents who venture outside during the height of the storm would be at risk of severe injury or death due to flying debris.
After battering these islands, Chaba is then expected to curve toward mainland Japan or the far northern Ryukyu Islands as a strong typhoon.
All residents from Nagasaki, Kagoshima, Hiroshima, Osaka and Tokyo are urged to closely monitor the progress of Chaba. How quick Chaba makes that turn will determine which areas endure the worst impacts.
"The timeframe for mainland Japan remains Tuesday and Wednesday for damaging winds and flooding rain from Chaba with the worst of the wind expected over southern Japan," AccuWeather Meteorologist Brian Thompson said.
"The tighter turn would bring impacts to Japan earlier, generally from Tuesday to the first half of Wednesday."
This scenario could allow the worst of Chaba's wind and rain to miss or only graze southwestern mainland Japan. Chaba could still move into and track across southern Honshu as a minimal typhoon by midweek.
"A wider turn would take the storm farther west before turning it to the northeast," Thompson said.
This would put the strong typhoon on a path into Kyushu later on Tuesday or Tuesday night before it barrels across mainland Japan at midweek, likely exiting around southeastern Honshu.
Land interaction and disruptive winds above the surface, known as wind shear, will cause Chaba to weaken as it crosses Japan.
"Despite weakening, flooding rain and gusty winds are possible in Tokyo, especially from late Tuesday night through Wednesday night," Thompson said.
It is also possible that the turn is wide enough for "tropical storm conditions to impact southeastern South Korea before impacting Japan on Wednesday," Thompson said.
Confidence is high that Chaba tracks away from northern Taiwan and eastern China.
However, a new tropical threat is brewing in the western Pacific and could bring risks to the northern Philippines, Taiwan and southeastern China during the second half of next week.