Guam and Northern Marianas: Typhoon Mawar moving over Guam and the Northern Mariana Islands as of late May 24 /update 6

Event

Typhoon Mawar is passing close to Guam and the Northern Mariana Islands late May 24. As of 22:00 ChST, the storm was approximately 102 km (63 miles) southeast of Andersen Air Force Base, Guam. The center of the storm passed through the Rota Channel between Guam and Rota islands late May 24 and is expected to continue to bring severe weather conditions across the island territories through at least May 25.

Forecast models indicate that after passing Guam and the Northern Mariana Islands, the system is likely to strengthen into a super typhoon by late May 25 as it tracks west-northwestward across the Philippine Sea late May 24-late May 27. Mawar is then forecast to weaken back into a typhoon on May 28 as it turns to track northwestward over the western Philippine Sea May 28-29. Some uncertainty remains in the track and intensity forecast; changes could occur in the coming days.

Authorities have issued typhoon warnings for Guam and Rota. Tropical storm warnings and typhoon watches have been issued for Saipan and Tinian. A flash flood warning has been issued for Guam, and flood watches and coastal flood warnings are in place for Guam and the Northern Marianas Islands through the afternoon of May 25. An extreme wind warning was issued for northern parts of Guam on May 24 but has now expired. Heavy rainfall is likely through May 25; 7.5-13 cm (3-5 inches) is possible. Authorities in Guam have warned that torrential rains may result in landslides and flash flooding, while catastrophic wind and life-threatening storm surges are likely, with potentially catastrophic coastal flooding possible for southeastern and southern portions of Guam if the storm makes landfall further south. Officials will likely issue new alerts or update/rescind existing advisories as the storm progresses.

Authorities in Guam ordered residents in all low-lying, flood-prone, and coastal areas to evacuate by 18:00 ChST May 23; all other residents are advised to remain indoors during the passing of the storm. Crews opened 12 emergency shelters in advance of the storm, but the shelter at Harry S. Truman Elementary School was closed due to generator problems. The shelter at Astumbo Elementary School is at capacity. As of early May 24, more than 900 people were evacuated to the emergency shelters.

A state of emergency was declared in Guam on May 22, and President Biden approved an emergency declaration for the Northern Mariana Islands and Guam on May 23 to allow for additional resources and assistance due to the potential impacts of the storms. Officials have suspended all commercial traffic in ports in Guam. Authorities in the Northern Marianas Islands canceled public school classes from May 23. Officials at Antonio B. Won Pat International Airport (GUM) have canceled most flights May 23-24. United Airlines (UA) canceled most flights to and from Guam and the Northern Mariana Islands May 23-24. Further cancelations and delays to other flights are likely as the storm approaches and weather conditions deteriorate.

Most of Guam is without power as of late May 24, and repair operations remain suspended due to adverse weather conditions; repairs are likely to resume when weather conditions improve. Authorities have also implemented precautionary water service interruptions on Rota Island. No casualties associated with the storm have yet been reported; however, it may take some time for the full extent of the storm's impact to be known, as comprehensive damage assessments will likely have to wait until the severe weather has passed.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

The inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at other regional airports and temporary closures of ports are also possible. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a severe health threat.

Advice

Activate contingency plans in areas where officials forecast tropical cyclone conditions. Heed any evacuation orders that may be issued. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the potential for severe flooding and storm surge. Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents and necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil-water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming weeks.

Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.

Resources

Joint Typhoon Warning Center