Typhoon Maria neared the southern Ryukyu Islands on Monday night. At 11:00 p.m. EDT on Monday night the center of Typhoon Maria was located at latitude 24.3°N and longitude 126.4°E which put it about 130 miles (210 km) east of Ishigaki, Japan. Maria was moving toward the west-northwest at 18 m.p.h. (29 km/h). The maximum sustained wind speed was 125 m.p.h. (205 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 949 mb.
Typhoon Maria weakened slowly on Monday, but it remained a powerful typhoon. Maria moved over some slightly cooler water mixed to the surface by recent Typhoon Prapiroon when it passed near the Ryukyu Islands. Maria was unable to extract enough energy from the upper ocean to maintain the intense wind speeds it produced during the weekend. However, Typhoon Maria was still the equivalent of a major hurricane. There was a circular eye with a diameter of 35 miles (55 km). A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Several bands of thunderstorms were revolving around the core of Typhoon Maria. Storms in the core were generating strong upper level divergence which was pumping mass away from the center of circulation.
Winds to typhoon force extended out about 70 miles (110 km) from the center of circulation. Winds to tropical storm force extended out about 200 miles from the center. The Hurricane Intensity Index (HII) for Typhoon Maria was 23.6. The Hurricane Size Index (HSI) was 23.8 and the Hurricane Wind Intensity Size Index (HWISI) was 47.4. Those indices indicated that Typhoon Maria was capable of causing widespread major damage.
Typhoon Maria will move through an environment capable of sustaining a strong typhoon on Tuesday. Maria will move west of the cooler water mixed to the surface by previous Typhoon Prapiroon and it will move over water where the Sea Surface Temperature is near 29°C. Typhoon Maria will move through a region where the upper level winds are weak and there will be little vertical wind shear. Maria could weaken slowly on Tuesday if it is unable to extract enough energy from the upper ocean to sustain its circulation. It could strengthen a little when it moves over slightly warmer water if it has time to extract more energy from the ocean.
Typhoon Maria was moving south of a subtropical ridge over the Western North Pacific Ocean. The ridge was steering Maria toward the west-northwest and that general motion is expected to continue during the 36 hours. On its anticipated track Typhoon Maria will reach the southern Ryukyu Islands in six to twelve hours. Maria will bring destructive winds, heavy rain and a storm surge. It will be capable of causing major damage to Miyako Jima, Ishigaki Jima, Iriomote Jima and the other islands in the southern Ryukyus. The strongest part of Typhoon Maria will pass south of Okinawa, which could experience rainbands in the outer portion of the circulation. Typhoon Maria will pass near northern Taiwan in about 18 hours. It will bring strong winds and locally heavy rain to that area and flash floods could occur. Maria could be near Fuding on the coast of China in about 24 hours.