The latest track of Tropical Storm Champi has the system passing just south of Guam as a Category 3 typhoon.
The forecast has the closest point of approach at 7 a.m. Sunday, but damaging winds will arrive around midnight.
As of 4 a.m., Champi was located near 11.9 north latitude and 150.2 east longitude, or about 380 miles east-southeast of Guam. It was moving west at 15 mph.
Champi had winds of 70 mph and was expected to become a typhoon within hours.
The storm was expected to turn slightly toward the west-northwest with little change in forward speed through Sunday.
Tropical storm-force winds extend 105 miles outward from the center of the system.
Paul Stanko of the National Weather Service says showers will begin gradually increasing around noon, and by sunset the winds and rains will pick up. Conditions will deteriorate through the night.
Emergency managers are urging residents to put up shutters if they have them; otherwise, board windows.
Make sure you have food, water and medication for several days, and pick up or secure anything outdoors that could become a projectile in high winds.
What to expect
Guam can expect rainfall of 12 to 20 inches, peak winds of 105 to 120 mph with gusts to 155 mph Sunday morning.
Surf will be up to 35 feet, with significant coastal inundation of 5 to 7 feet.
Rota can expect total rainfall of 10 to 15 inches, peak winds of 60 to 80 mph with gusts to 115 mph Sunday morning and surf up to 25 feet.
Saipan and Tinian will get rainfall of 4 to 6 inches, peak winds of 40 to 60 mph with gusts to 80 mph Sunday morning, surf up to 20 feet and coastal inundation of 1 to 3 feet.
