Guam in COR 3; Sinlaku anticipated to bring damaging winds within 48 hours

By Jayvee Vallejera

Gov. Lou Leon Guerrero placed Guam in Condition of Readiness 3 at 5 p.m. today in anticipation of Tropical Storm Sinlaku.

Damaging winds of 39 mph from Tropical Storm Sinlaku are expected within 48 hours. 

 "The latest forecast track shows an intensifying system, with potential to reach Category 3 or 4 status, around 120 mph, at its center as it makes a very close approach, passing near Guam Monday night into Tuesday,” the governor said.

“This storm has the potential to be very dangerous.  Residents should start to prepare now," Lt. Gov. Josh Tenorio said.

The Joint Region Marianas hoisted a Tropical Cyclone Condition of Readiness Storm Watch on Guam.

The latest forecast shows an intensifying system with potential to reach Category 3 or 4 strength, with winds around 104 knots (120 mph), near Guam.

Currently tracked is located in Chuuk, Sinlaku is predicted turn toward the Marianas in the next two days has already prompted

Brandon Aydlett, meteorologist at the National Weather Service, said in a news briefing today that Tropical Storm Sinlaku, formerly known as Tropical Depression 04W, is tracking toward the Marianas region and could pass near Guam between Monday and Wednesday next week.

“While we'll be breezy with trade winds into Sunday, the more notable winds don't arrive until Sunday night with tropical storm winds or greater anticipated between Monday morning and Wednesday morning. The typhoon conditions, based on the current forecast track, will arrive on Tuesday,” he said.

Damaging winds of 34 knots (39 mph) or more are possible as early as Monday morning, with destructive typhoon-force winds of 64 knots (74 mph) or more possible for Guam Monday night or early Tuesday morning, according to JRM.

As of the latest forecast, Tropical Storm Sinlaku is approximately 500 nautical miles east-southeast of Guam, moving slowly northwest.

Rainfall forecasts predict 15 to 20 inches of rain between Monday and Wednesday, Aydlett said during a Facebook Live briefing.

“As currently forecast, a typhoon-force Sinlaku will move slowly over or near Guam Monday to Wednesday, bringing a prolonged event of at least tropical storm force winds and heavy rains. A direct passage would threaten significant flood concerns,” Aydlett said.

Based on current models, NWS is looking at Sinlaku as having a potential to become a 120mph Category 3 typhoon, Aydlett said.

The last significant storm to pummel Guam was Typhoon Mawar, which hit the territory in 2023 as a Category 4 typhoon at 130 mph.

“A prudent precaution would be to plan for slightly stronger typhoon, in case of faster intensification,” Aydlett said during a briefing at the Guam Homeland Security Office of Civil Defense.

JRM said in a news release that its Tropical Cyclone Condition of Readiness Storm Watch was declared in order for its base commanders to take preparatory actions. This storm watch will be upgraded as sustained winds from Sinlaku become stronger.

The U.S. Coast Guard cautions residents and mariners to monitor official guidance from the National Weather Service and local emergency management authorities and take protective action now, before conditions deteriorate.

The Joint Typhoon Warning Center is tracking Sinlaku as an intensifying system with potential to reach typhoon strength by Saturday.

The National Weather Service Guam Weather Forecast Office warns that damaging tropical storm force winds of 39 miles per hour or greater are possible for Guam as early as Sunday, with destructive typhoon force winds possible Monday night or early Tuesday morning.

Track and intensity forecasts carry uncertainty; conditions may change rapidly in either direction.