Typhoon Sinlaku continued to bring strong winds and heavy rain to the Northern Marianas on Wednesday.  At 5:00 a.m. EDT on Wednesday the center of Typhoon Sinlaku was located at latitude 16.2°N and longitude 144.8°E which put the center about 80 miles (130 km) northwest of Saipan.  Sinlaku was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 944 mb.

Typhoon Warnings remain in effect for Rota, Tinian, Saipan, Pagan, Alamagan, and Agrihan.

A Tropical Storm Warning remains in effect for Guam.

A Typhoon Watch also remains in effect for Guam.

Typhoon Sinlaku completed an eyewall replacement cycle on Wednesday.  A circular eye with a diameter of 35 miles (55 km) was present at the  center of Sinlaku’s circulation.  Bands of showers and thunderstorms were revolving around the core of Typhoon Sinlaku.  Storms near the core of Sinlaku generated upper level divergence that pumped mass away from the typhoon.  The removal of mass in the upper levels of the atmosphere was less than the convergence of mass in the lower levels.  So, the surface pressure was continuing to increase gradually.

The circulation around Typhoon Sinlaku was large.  Winds to typhoon force extended out 75 miles (120 km) from the center of Sinlaku’s circulation.  Winds to tropical storm force extended out 275 miles (445 km) from the center of Typhoon Sinlaku.

The Hurricane Intensity Index (HII) for Typhoon Sinlaku is 23.6.  The Hurricane Size Index (HSI) is 28.3 and the Hurricane Wind Intensity Size Index (HWISI) is 51.9.  Typhoon Sinlaku is similar in size and intensity to Hurricane Wilma when Wilma hit South Florida in 2005.

A weather station at the Guam International Airport recently reported a sustained wind speed of 28 m.p.h. (45 km/h) and a wind gust of 45 m.p.h. (73 km/h).  There were no recent reports from weather stations on Rota, Tinian, or Saipan.

Typhoon Sinlaku was moving slowly west of the Northern Marianas.  The slow movement was prolonging the period destructive wind and rain in Tinian and Saipan.  Sinlaku was capable of causing major damage.  Prolonged heavy rain is likely to cause flash floods.

Flood Watches remain in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Sinlaku could cause a storm surge of up to 10 feet (3 meters).

Typhoon Sinlaku will move around the western part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Sinlaku toward the north-northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Sinlaku will move very slowly away from Tinian and Saipan.  Sinlaku will move parallel of the Northern Marianas on Wednesday.

Typhoon Sinlaku will move through an environment that will be marginally favorable for a strong typhoon during the next 24 hours.  Sinlaku will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the middle of an upper level ridge that is over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Sinlaku will move into a region where the air is drier.  The drier air is likely to inhibit the development of thunderstorms in the northern and western parts of Sinlaku’s circulation.  Typhoon Sinlaku is likely to continue to weaken gradually during the next 24 hours because of the recently completed eyewall replacement cycle and the drier air.