If Kong-Rey continues moving as forecast, it's due to pass 104 miles west-southwest of Kadena at 2 a.m. Friday, still packing 92-mph sustained winds and 115-mph gusts - a Category 2-equivalent intensity.
The ex-typhoon has been travelling north-northwestward at a speed of 14mph over the past six hours.
The current trajectory of Kong-rey will see it move from Okinawa in a northward direction toward the Korean Peninsula, the JMA said, before reaching coastal areas of the Sea of Japan.More news: Centre challenges non-BJP states to cut Value-Added Tax on fuel
Kong-rey is now packing wind speeds of 69mph with higher gusts of 86mph.
This storm is not forecast to dump almost as much rain, but portions of southern Japan and South Korea could see upwards of 250 mm (6 inches) of rain as Kong-rey passes by - which could lead to flash flooding and the potential for landslides.
The weather has fallen quiet across Japan but in the wake of Typhoon Trami, which left four people dead, the next storm is gathering pace in the northwest Pacific.More news: Trump NYT tax report 'false attack': White House
In late August, Typhoon Soulik hit the country, leaving one person missing and two others injured.
It was the strongest typhoon since Typhoon Yancy hit in 1993. At this stage, it could still be a typhoon but is more likely to be a strong tropical storm with winds down to 115 gusting 140km/h.
Fierce winds and torrential rain from the weather system could trigger mudslides, flash floods and high waves. Now it is 340 kilometers from the southern island of Miyakojima.More news: Tesla shares drop after Musk mocks SEC on Twitter