The world is on edge this afternoon as we await news from Vanuatu's capital city of Port Vila to see how they fared the wrath of Severe Cyclone Pam. The storm had estimated winds of 165 MPH as its eyewall brushed the capital island's 66,000 inhabitants on Friday around 9:00 AM EDT.

Tropical cyclones—also known as "hurricanes" around North America and "typhoons" in Asia—don't get much more intense than Pam. The storm's display on satellite imagery is as close as you can get to perfect, with vast, spiraling bands radiating from a dense donut of angry rain and winds.

Cyclones are reversed in the Southern Hemisphere, with winds flowing clockwise around the circulation. When we deal with hurricanes in the Atlantic Ocean, for example, the most dangerous part of the storm is the right-front quadrant—in the Southern Hemisphere, the most intense winds in a cyclone are in the left-front quadrant, or in this case, on the eastern side of Pam's eyewall. This is a small but important detail when you see that Port Vila wound up just on the western edge of the cyclone's eye:

The fact that Efate was on the western side of the eyewall—and Port Vila is on the western side of Efate—likely spared the city from a worse fate than it may have already suffered. A weather station in Port Vila recorded 76 MPH winds with gusts to 99 MPH before it went offline around 2:00 AM EDT. Australia's Bureau of Meteorology has an excellent resource for keeping track of weather conditions in Port Vila, and the station managed to stay online through the whole storm.

The air pressure in Port Vila dropped to a minimum of 942.2 millibars, which is about what you would expect in the center of a category three hurricane in the Atlantic Ocean, and extremely deep considering that the actual eye of the cyclone was 10 or 20 miles to Port Vila's east. The central minimum pressure of Cyclone Pam probably bottomed-out between 915 and 925 millibars. The station's anemometer only recorded wind gusts up to 59 MPH, which means it's either obstructed (by debris, trees, or a building) or malfunctioning. Winds were likely more than twice that strong in the city.

Reports from residents and visitors to the island nation are few and far between, as one would expect for such an intense cyclone striking a relatively remote location. Several people in and around Port Vila have commented on iCyclone's Facebook posts. Earlier this afternoon, the BBC published unconfirmed reports of "dozens feared dead" on Vanuatu's northern islands as the cyclone pushed through, but initial reports are often speculative or wildly inaccurate; it will be days before we know the true extent of the damage.

Cyclone Pam is the strongest storm to strike Vanuatu since Cyclone Uma tore through the country back in February 1987, and Pam will go down in the books as one of the strongest tropical cyclones ever recorded in the South Pacific.

[Images: Wunderground, Colorado State University, CIMSS, BoM]


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