Typhoon Shanshan intensified to the equivalent of a major hurricane near the northern Ryukyu Islands on Monday evening.  At 11:00 p.m. EDT on Monday the center of Typhoon Shanshan was located at latitude 28.3°N and longitude 130.6°E which put the center about 75 miles (120 km) east of Naze, Japan.  Shanshan was moving toward the northwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 943 mb.

Typhoon Shanshan intensified to the equivalent of a major hurricane on Monday evening as it moved slowly near the northern Ryukyu Islands.  A small circular eye with a diameter of 12 miles (19 km) was at the center of Shanshan’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Shanshan.  Storms near the core generated strong upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Shanshan was symmetrical.  Winds to typhoon force extended out 40 miles (65 km) from the center of Shanshan’s circulation.  Winds to tropical storm force extended out 125 miles (200 km) from the center of Typhoon Shanshan.

The Hurricane Intensity Index (HII) for Typhoon Shanshan was 22.1.  The Hurricane Size Index (HSI) was 13.7 and the Hurricane Wind Intensity Size Index (HWISI) was 35.8.  Typhoon Shanshan was similar in size to Hurricane Delta when Delta hit southwest Louisiana in 2020.  Shanshan was stronger than Delta was.

Typhoon Shanshan will move through an environment that will be favorable for intensification during the next 24 hours. Shanshan will move over water where the Sea Surface Temperatures are near 29°C.  It will through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Shanshan is likely to continue to intensify during the next 24 hours.

Typhoon Shanshan will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Shanshan slowly toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Shanshan will move over the northern Ryukyu Islands.  Shanshan could approach southwestern Japan in 48 hours. Shanshan could be a strong typhoon when it approaches Kyushu.

Typhoon Shanshan will bring strong winds and heavy rain to the northern Ryukyu Islands.  Shanshan will be capable of causing major damage.  Heavy rain is likely to cause flash floods in some locations.  Typhoon Shanshan will also cause a storm surge on the northern Ryukyu Islands where the wind blows the water toward the shore.