Super Typhoon Mawar poised to slam into Guam today with catastrophic effects

Mawar — an extremely intense typhoon in the tropical Pacific Ocean centered about 5,800 miles west of San Francisco — is on a dangerous collision course with the U.S. territory of Guam. The super typhoon, packing maximum sustained winds of 155 mph, is predicted to slam into the island between this morning and afternoon local time. Forecasters expect the storm to unleash a “triple threat” of destructive winds, a dangerous ocean surge and excessive rainfall that will cause flooding.

The rapidly strengthening storm reached the equivalent of a high-end Category 4 hurricane Tuesday afternoon on approach to the island. Its peak winds of 155 mph are just a few ticks shy of top-tier Category 5 strength and qualify it as “super typhoon,” meaning it has maximum winds of at least 150 mph. Tropical storms with winds of at least 74 mph in the western Pacific Ocean are called typhoons, but they are no different than hurricanes in the Atlantic Ocean with respect to how they form and their effects.

Conditions began to deteriorate Tuesday night over Guam as gusty rain squalls moved in, with progressively more violent storminess anticipated into today.

Ahead of the storm, President Joe Biden approved an emergency declaration that orders federal assistance in response to the typhoon. In addition to civil concerns, the island is home to Andersen Air Force Base and other U.S. military assets.

Winds of 130 to 150 mph or higher are likely to lead to widespread power outages in Guam, as well as the potential for cars to be overturned, poorly constructed buildings ripped apart and foliage stripped from trees, among other effects.

Rainfall of 10 to 15 inches or more is also possible. The National Weather Service forecast office serving Guam notes the potential of up to 7 inches of rain in one hour as the eyewall passes. Serious flooding and landslides are likely. Alex Lamers, a meteorologist with the National Weather Service, noted on Twitter that the storm is progressing at an unusually slow speed of just 7 mph, which will prolong heavy rainfall and increase the flood threat.

Gov. Lou Leon Guerrero ordered mandatory evacuations of low-lying coastal locations of the island early Tuesday.

RICK CRUZ/PACIFIC DAILY VIA AP The Laelae River in Umatac, Guam, becomes swollen with rain runoff Tuesday as Super Typhoon Mawar approaches. Rainfall of 10 to 15 inches or more is possible. Serious flooding and landslides are likely. Winds of 130 to 150 mph or higher are likely to lead to widespread power outages across the island.