Super Typhoon Mawar forecast trail: Guam could be hit by strongest storm in decades

CNN
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Typhoon Mawar was heading into Guam early Wednesday, threatening to smash into US territory as the strongest storm in decades.

The typhoon, which has strengthened rapidly in recent days, poses a ‘triple threat’ of devastation, including deadly winds equivalent to at least a Category 4 hurricane, exceptional storm surge and torrential rain, according to the office of the National Weather Service in Guam.

Mawar has been described as “one who will be remembered for decades,” said Landon Aydlett, the meteorologist in charge of coordinating Guam weather service warnings. It is expected to hit the island – and possibly make landfall directly – on Wednesday afternoon local time. (late Tuesday or early Wednesday, Eastern Time).

As of Wednesday morning local time, the center of Mawar was 80 miles from Guam, and conditions were rapidly deteriorating as the storm’s outer bands moved through the region and the storm’s core approached.

Mawar’s maximum sustained winds were 140 mph early Wednesday, the equivalent of a Category 4 hurricane, according to the Joint Typhoon Warning Center. That’s down from 155 mph earlier, giving it super typhoon status at the time (sustained winds of at least 150 mph).

Forecasters had warned that Mawar could reach the equivalent of a Category 5 hurricane – sustained winds exceeding 157 mph – before making landfall. Fluctuations in strength were still possible Wednesday morning, and the storm is expected to remain very intense as it moves west and northwest over Guam over the next few days.

The storm’s forward motion slowed to 6 mph on Wednesday morning. Such a slow pace would result in prolonged wind impacts and greater amounts of precipitation.

“Guam will see the devastating effects of Typhoon Mawar,” the Guam National Weather Service said.

If the typhoon makes direct landfall, the island would be buffeted by the storm’s strongest winds and strongest storm surge.

Although Guam is located in the western Pacific Ocean – an area subject to the most powerful tropical cyclones in the world – a direct hit from a storm, this force is extremely rare and has only occurred about eight times over the past of the past 75 years. The island is only 30 miles long, so moving the center of a storm would be like threading a small needle.

Mawar may be the strongest storm to directly impact Guam since at least 1976, when Typhoon Pamela hit with sustained winds of 140 mph. If Mawar hits with higher sustained winds, it would be the strongest since Super Typhoon Karen, widely considered the worst storm to ever hit the island, hit in 1962 with sustained winds of 172 mph.

Human-caused climate change stacks the deck in favor of more intense storms like Typhoon Mawar. Not only do these systems generate more precipitation and larger storm surges, but they are also more likely to be stronger and intensify faster.

Mawar underwent an extremely rapid intensification from Monday to Tuesday, with peak wind speeds increasing by 50 mph in just 18 hours. Scientists have warned that the rapid intensification of tropical cyclones – like typhoons and hurricanes – is more likely as ocean temperatures climb and set the stage for the cyclones to explode into killer storms at a breakneck pace.

As winds sway near Category 5 force, considerable damage is likely to be caused to buildings that are not reinforced with concrete, forecasters have warned. Significant damage to the roof is possible, as well as flying projectiles that are thrown through the air by the powerful winds.

“Power and water may be unavailable for days or even weeks after the storm passes” and “most trees will be snapped or uprooted,” the Guam Weather Service warned. Up to 70% of the island’s foliage could be torn off by the strong Mawar winds.

An exceptional storm surge of up to 25 feet will pose a significant risk to life and property on the island, especially in the most vulnerable coastal areas near the eyewall.

Storm surge-related deaths are historically the leading cause of hurricane-related deaths in the United States, according to the National Weather Service. This level of storm surge will likely cause severe coastal erosion and “large boats could be torn from the moorings” according to the weather service.

In addition to coastal flooding from storm surges, flash flooding is possible as the storm is expected to bring 10 to 15 inches of rain, with locally higher amounts up to 20 inches possible.

A flood watch is currently in effect for the entire area as rain will intensify as the storm approaches. Even “higher precipitation totals” are possible if the storm slows its forward speed, the weather service warned.

Landslides will also become likely as the ground becomes saturated and the ground along hilly terrain becomes unstable.