Super Typhoon Hagupit
has exploded into mighty Category 5 storm with 175 mph winds and a central pressure of 905 mb,
and is threatening the same portion of the Philippine Islands devastated by Super Typhoon Haiyan in November 2013. The spiral bands of the massive storm are already bringing gusty winds and heavy rain showers to Samar and Leyte Islands, which bore the brunt of Haiyan’s massive storm surge and incredible winds--rated at 190 mph at landfall on November 7, 2013 by the Joint Typhoon Warning Center. Haiyan killed over 7,000 people in the Philippines, with Tacloban (population 200,000) suffering the greatest casualties, thanks to a 20+’ storm surge. Thousands of people still live in tents in Tacloban in the wake of Haiyan, and mass evacuations have begun to get these vulnerable people to safety.Figure 1.
An infrared VIIRS image of Super Typhoon Hagupit from the Suomi satellite at 15:55 UTC December 3, 2014, revealed a structure very similar to that of the standard hurricane symbol (lower right.) At the time, Hagupit was an intensifying Category 4 storm with 150 mph winds. Image credit: Dan Lindsey, NOAA/NESDIS/CIRA/Colorado State.Forecast for Hagupit
Hagupit is over very warm ocean waters of 29 - 30°C (84 - 86°F) and is under moderate wind shear of 15 - 20 knots. Satellite loops
show that Hagupit has a prominent 14-mile diameter eye, and a large area of very intense eyewall thunderstorms with cold cloud tops. The eyewall is lopsided, due to winds on the east side of the storm causing wind shear of 15 - 20 knots and and interfering with development of the thunderstorms on the east side of the storm. Thursday morning microwave images indicate that Hagupit is likely undergoing an eyewall replacement cycle, where the inner eyewall shrinks, collapses, and is replaced by an outer eyewall with larger diameter. This process will likely cause a modest weakening of Hagupit, to perhaps 150 mph winds, by Friday. But with warm waters and moderate wind shear expected until landfall, Hagupit should be able to make landfall as a very dangerous Category 4 typhoon in the Central Philippines. The ridge of high pressure steering Hagupit has weakened since Wednesday, forcing the storm to slow its forward speed from 21 mph to 14 mph. The trough of low pressure passing to the north that is weakening the ridge will move eastwards past the Philippines on Friday, which will potentially allow the ridge to build back in stronger than before, and force Hagupit on a more westerly path—or even west-southwesterly path—as it approaches landfall on Samar or Leyte Island near 12 UTC Saturday. Most of the models that had shown Hagupit recurving to the north and missing the Philippines have now followed the lead of the reliable European model, which has been consistently showing landfall in the Central Philippines. The latest 12Z Thursday runs of our two most reliable models, the GFS and European, are now very close, showing a landfall in southern Samar Island, just north of where Haiyan hit in November 2013. If this track hold true, it would avoid a major storm surge disaster in Tacolban like Haiyan brought. Extreme winds, a large and deadly storm surge, and torrential rains causing massive flooding and dangerous mudslides are all of great concern for where Hagupit makes landfall.Figure 2.
MODIS satellite image of Typhoon Hagupit at 02:10 UTC on Thursday December 4, 2014. At the time, Hagupit was a Category 5 storm with 180 mph winds. Image credit: NASA.Hagupit is Earth's seventh Category 5 storm of 2014
Hagupit is Earth's seventh Category 5 storm of the year, making it the busiest year for these most extreme of tropical cyclones since 2005. In that year, eleven Category 5s were recorded (4 in the Atlantic, 2 in the Western Pacific, 3 in the South Indian, and 2 in the South Pacific.) Hagupit is the fifth Category 5 in the Western Pacific in 2014, and the fourth with a pressure of 915 mb or lower, as rated by the Japan Meteorological Agency.
The last time four or more typhoons reached that intensity was 1997, when five did so. The other Category 5 storms of 2014:Super Typhoon Nuri
hit 180 mph winds east of Japan on November 3. The Japan Meteorological Agency
put Nuri's lowest central pressure at 910 mb. The extratropical remounts of Nuri went on to bomb into one of the most intense extratropical storms ever observed in the waters near Alaska, with a central pressure of 924 mb. Super Typhoon Vongfong
also had 180 mph winds south of Japan. Vongfong battered Japan's Okinawa Island on October 9 - 10, killing 11 and doing $58 million in damage. The Japan Meteorological Agency
put Vonfong's central pressure at 900 mb at the storm's peak intensity, the lowest pressure it has given to a storm since Super Typhoon Haiyan's 895 mb pressure in November 2013.Super Typhoon Halong
topped out at 160 mph winds with a central pressure of 920 mb on August 3, eventually making landfall in Japan on August 10 as a tropical storm. Halong killed 12 and did $4 million in damage.Super Typhoon Genevieve
(160 mph winds, 915 mb pressure) did not affect land.
Another Western Pacific Super Typhoon, Rammasun,
was only rated a Cat 4 when it hit China's Hainan Island on July 17, killing 195 people and causing over $7 billion in damage. However, a pressure characteristic of a Category 5 storm, 899.2 mb, was recorded at Qizhou Island just before Rammasun hit Hainan Island. If this pressure is verified, it is likely that the storm will be upgraded to be 2014’s eighth Category 5 storm in post-season reanalysis.
The Eastern Pacific had one Cat 5 in 2014 that did not affect land: Marie (160 mph winds). The South Indian Ocean has had one Cat 5 this year, Tropical Cyclone Gillian in March (160 mph winds.) Gillian did not affect any land areas. Between 2000 - 2013, Earth averaged five Category 5 storms per year, with 51% of these occurring in the Western Pacific. Since 1996, only two years have had more than eight Category 5 storms in one year: 1997 (thirteen) and 2005 (eleven.)
Our database of these most extreme of tropical cyclones is of poor quality and there are not enough of them to say if they are showing climate-related trends yet or not, but the forecast is for more of these high-end tropical cyclones to occur in a warmer climate. The 2013 IPCC report
predicts that there is a greater than 50% chance (more likely than not) that we will see a human-caused increase in intense hurricanes by 2100 in some regions, and the 2014 U.S. National Climate Assessment
said “Hurricane-associated storm intensity and rainfall rates are projected to increase as the climate continues to warm.”