Eyeing Super Typhoon Megi
Satellite image of Super Typhoon Megi as it approached the island of Luzon in the Philippines on Oct. 18.
Credit: CIMSS/University of Wisconsin.
Every once in a while an image comes along that perfectly captures an awe-inspiring force of nature, such as a hurricane or tornado, in a way that makes it seem beautiful rather than devastating or terrifying. Today a satellite image came across my Twitter feed (hat tip to Brad Panovich, chief meteorologist at News Channel 36 in Charlotte, N.C.) that immediately grabbed my attention. It comes from NASA's Terra satellite, which carries an instrument called a "Moderate Resolution Imaging Spectroradiometer," or MODIS. The MODIS image above shows cloud-top temperatures in Super Typhoon Megi as it approached the island of Luzon in the Philippines earlier today, packing sustained winds of 165 miles per hour with higher gusts.
Megi caused significant damage across the island, and is now back over ocean waters and heading for a second landfall in mainland China.
The picture shows the storm's extremely well-defined eye and the towering thunderheads surrounding it, which is where the storm's strongest winds can be found. The colors correspond to the coldness of the cloud tops, with the purple regions just to the south of the eye, as well as to the east/southeast, showing an infrared brightness temperature as low as -82°C, which corresponds to an area of especially intense precipitation and strong winds.
According to Weather Underground senior meteorologist Jeff Masters, Megi was more intense — as measured by surface air pressure — than all but two Atlantic Ocean hurricanes in history, Wilma in 2005 and Gilbert in 1988.
The Hurricane Hunters measured winds at flight level of 220 mph, which normally translates to a surface wind speed of 198 mph, using the standard 10% reduction. The SFMR surface wind measurement instrument recorded surface winds of 186 mph in regions where heavy rain was not contaminating the measurement, but found surface winds of 199 mph in one region of heavy rain. Now, this measurement is considered contaminated by rain, but at very high wind speeds, the contamination effect is less important than at lower hurricane wind speeds, and it is possible than Megi's surface winds reached sustained speeds of 200 mph. However, data from a dropsonde in the eyewall at the time supported giving Megi just 180 mph sustained winds. This is still a ridiculously strong wind, equivalent to a violent EF-4 tornado on the Enhanced Fujita Scale.
Update: Wednesday October 20:
According to the Washington Post's Capital Weather Gang blog (disclosure: I am a regular contributor to that blog), Category Four Typhoon Megi is currently forecast to follow a path that could spare Hong Kong from the strongest winds and a major storm surge. However, Hong Kong, along with a large portion of the southeast China coastline, is still going to be affected by high winds and heavy rain. Reports are trickling in from the Philippines, where damage was extensive but the death toll may have been remarkably low for such a powerful storm, due to civil defense efforts.
You can follow the storm's progress on the Hong Kong Observatory radar, as well as via the Joint Typhoon Warning Center. The Christian Science Monitor has put together a photo gallery of Megi's impacts in the Philippines as reports trickle in.
Here is a more recent satellite snapshot, courtesy of NASA's Earth Observatory.
Category Four Typhoon Megi in the South China Sea. Credit: NASA.