wunderground.com - Dr. Jeff Masters - 11 August 2013
Earth's most dangerous tropical cyclone so far in 2013 is Category 4 Typhoon Utor, which is closing in on the northern Philippine Island of Luzon. Landfall is expected at approximately 20 UTC (4 pm EDT) Sunday near Casigran. Satellite imagery shows a formidable storm with well-organized spiral bands, a prominent eye, and good (but not excellent) upper-level outflow. Ocean temperatures are very warm, about 30°C (86°F), which is approximately 0.5 - 1.0°C above average. These warm waters extend to tremendous depth, giving Utor a huge source of energy to tap into. Wind shear is low, 5 - 10 knots. Theoretically, the Maximum Potential Intensity (MPI) that Utor can achieve under these conditions is sustained winds of 185 mph. However, Utor will not have time to reach that strength before encountering Luzon. The official forecast from the Joint Typhoon Warning Center calls for intensification to 140 mph winds by 18 UTC Sunday, but it is possible that Utor will have time to intensify to a 150 mph super typhoon before landfall. Utor is a very wet storm, and will likely bring a large swath of 8+ inches of rain across Luzon. These rains will cause dangerous flash flooding and mudslides. Utor will likely weaken to a Category 1 storm as it passes over Luzon, but is expected to re-intensify to a Category 2 storm before hitting China a few hundred miles south of Hong Kong about 20 UTC on Tuesday.
Utor is a Marshallese word for squall line, and has been used for three tropical cyclones in the Western Pacific--in 2001, 2006, and 2013. Typhoon Utor is called Typhoon Labuyo in the Philippines. Utor's 135 mph winds make it the 2nd strongest tropical cyclone globally so far in 2013. Earth's most powerful tropical cyclone in 2013 was Typhoon Soulik, which reached Category 4 strength with 145 mph winds on July 10, before weakening to a Category 2 storm that hit Taiwan on July 12.
Figure 1. MODIS satellite image of Typhoon Utor taken at 04:30 UTC on Sunday, August 11. Image credit: NASA.
The Philippines no stranger to powerful typhoons
The Philippines lie in the most tropical cyclone-prone waters on Earth, and rarely escape a year without experiencing a devastating typhoon. Usually, these storms impact the northern Philippine island of Luzon, but last year, Earth's deadliest weather disaster of 2012 occurred on the southern Philippine island of Mindanao, where Super Typhoon Bopha struck as a Category 5 super typhoon with winds of 160 mph (260 km/h), on December 3. Bopha made two additional landfalls in the Philippines, on central Visayas and on Palawan, on December 4. The typhoon left 1901 people dead, mostly on the island of Mindanao, making Bopha the 2nd deadliest typhoon in Philippine history. Bopha affected over 5.4 million people and left over 700,000 people homeless. With damages estimated at $1.7 billion, Bopha was the costliest natural disaster in Philippines history.
Figure 2. December 7, 2012: rescuers and residents look for missing victims amongst toppled tree trunks and coconut shells after flash floods caused by Super Typhoon Bopha hit Compostela Valley on Mindanao Island in the Philippines on December 3 - 4, 2012. (AP Photo/Jay Morales, Malacanang Photo Bureau, HO)
Quiet in the Atlantic
There are no tropical cyclone threat areas in the Atlantic to discuss today. Some of the models are suggesting a strong tropical disturbance capable of becoming a tropical storm could form by Saturday in the Gulf of Mexico near Mexico's Yucatan Peninsula, in association with a stalled cold front expected to push off the Southeast U.S. coast late this week.
Jeff Masters
Source: http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2485
