Typhoon Rai brought gusty winds and rain to central Vietnam on Sunday. At 10:00 a.m. EST on Sunday the center of Typhoon Rai was located at latitude 15.5°N and longitude 110.8°E which put it about 185 miles (295 km) east-southeast of Da Nang, Vietnam. Rai was moving toward the north at 11 m.p.h. (17 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 951 mb.

Bands in the western side of Typhoon Rai brought gusty winds and locally heavy rain to central Vietnam on Sunday. Although the core of Typhoon Rai was east of Vietnam, the large size of the circulation resulted in rainbands in the western side of the typhoon moving over central Vietnam. The core of Rai’s circulation where the strongest winds were located remained east of the coast of Vietnam.

Typhoon Rai was weakening over the South China Sea on Sunday. An upper level ridge over the Western North Pacific Ocean was producing southerly winds that were blowing toward the top of Rai’s circulation. A surface high pressure system over Asia was producing northeasterly winds in the lower levels of the atmosphere. The combination of southerly winds in the upper levels and northeasterly winds in the lower levels was causing moderate vertical wind shear. In addition, the northeasterly winds in the lower levels were transporting drier air toward Typhoon Rai.

Some of the drier air was wrapping around the southern side of Typhoon Rai. The strongest thunderstorms were occurring in bands in the western half of Rai’s circulation. Bands in the eastern half of the typhoon consisted primarily of showers and lower clouds. A broken ring of thunderstorms surrounded the eye of Typhoon Rai and the strongest winds were occurring in that ring of storms.

Winds to typhoon force extended out 65 miles (105 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 22.1. The Hurricane Size Index (HSI) was 20.6 and the Hurricane Wind intensity Size Index (HWISI) was 42.7. Rai was capable of causing regional major damage.

Typhoon Rai will move through an environment that will become unfavorable for intensification during the next 36 hours. Rai will move over water where the Sea Surface Temperatures are near 28˚C. However, the upper level ridge and the surface high pressure system will continue to cause moderate vertical wind shear. More dry air will be pulled into Rai’s circulation. Typhoon Rai will continue to weaken during the next 36 hours.

Typhoon Rai will move around the western end of a surface high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Rai toward the north. On its anticipated track the core of Typhoon Rai will remain east of Vietnam. Bands in the western side of Rai’s circulation will continue to produce gusty winds and locally heavy rain along the coast of Vietnam. The center of Rai could be southeast of Hainan in 18 hours.