Winds, seas and surf are anticipated to build across Guam and the Commonwealth of the Northern Mariana Islands throughout Thursday, possibly becoming hazardous by Friday as the National Weather Service Guam tracks Tropical Depression 26W, which is forecast to pass north of Saipan.

The Joint Typhoon Warning Center upgraded 93W to Tropical Depression 26W on Wednesday. The upgrade makes this weather event the 26th tropical cyclone in the western North Pacific in 2026.

"Located within the NWS Guam Area of Responsibility near 15.7N 151.6E, NWS Guam is now issuing Public Advisories every 6 hours on TD 26W. Additionally, tropical storm watches are now in effect for Alamagan, Pagan and Agrihan Islands in the Northern Mariana Islands," Warning Coordination Meteorologist Landon Aydlett said as of 1:30 p.m. Wednesday.

By 5:13 a.m. Thursday, NWS reported 26W moving west-northwest toward Alamagan. In addition to the Tropical Storm Warning, a Typhoon Watch for Alamagan and Pagan had also been issued.

"A Tropical Storm Watch means that tropical storm conditions, including winds of 39 to 73 mph, are possible within 48 hours. A Typhoon Watch means that typhoon conditions, including winds of 74 mph or more, are possible within 48 hours. A Tropical Storm Warning means that tropical storm conditions are expected within 24 hours," NWS Public Tropical Cyclone Advisory 3A states.

As of 5 a.m. Thursday, 26W was located 395 miles east-northeast of Guam, with maximum sustained winds of 40 mph, moving west-northwest at 5 mph.

"At 500 AM CHST...1900 UTC...the center of Tropical Storm 26W was located near Latitude 16.2 degrees North and Longitude 150.0 degrees East. 26W is moving west-northwest at 5 mph. It is expected to make a slight turn toward the west, then north-northwest, with a slight increase in forward speed through Friday. The latest forecast shows an intensifying 26W will move into the CNMI on Friday, curving north-northeast as it nears Alamagan Friday night as a Category 1 typhoon, then pass near Pagan and east of Agrihan Saturday," Advisory 3A states.

Forecasters said 26W has the potential to become a typhoon late Friday morning.

"Tropical storm force winds extend outward from the center up to 100 miles to the northwest," NWS Guam said.

An updated advisory will be issued at 7 a.m. Thursday, followed by another at 11 a.m.