楼主#更多 发布于：2014-12-02 14:28
By: Dr. Jeff Masters,
The 2014 Atlantic hurricane season is officially in the books, ending up with below average activity--8 named storms, 6 hurricanes, 2 intense hurricanes, and an Accumulated Cyclone Energy (ACE) that was 63% of the 1981 - 2010 median. The 2014 numbers were below the 1981 - 2010 average of 12 named storms, 6 hurricanes, and 3 major hurricanes, and way below the averages from the active hurricane period 1995 - 2013: 15 named storms, 8 hurricanes, and 4 major hurricanes, with an ACE index 151% of the median. The death and damage statistics for the 2014 Atlantic hurricane season were gratifyingly low: there were only five deaths (four from Hurricane Gonzalo in the Lesser Antilles and one from Tropical Storm Dolly in Mexico), and total damages from all storms were less than $500 million. The quiet season was due to an atmospheric circulation that favored dry, sinking air over the tropical Atlantic, and high wind shear over the Caribbean. Sea Surface Temperatures were also near-average--considerably cooler than what we've gotten used to since the active hurricane period that began in 1995.
Figure 1. Tracking chart for the 2014 Atlantic hurricane season. Image credit: NHC.Some notable facts from the 2014 Atlantic hurricane season, as provided by Philip Klotzbach and Bill Gray of Colorado State:- For the ninth consecutive year, no major hurricanes hit the U.S., marking the first time since records began in 1851 the U.S. has gone that long without a Category 3 or stronger hurricane hitting. The previous record was eight years, set in 1861 - 1868. Wilma of 2005 was the last major hurricane to hit the U.S., and was also the last hurricane to hit Florida.- For the ninth consecutive year, Florida went without a hurricane strike. This is Florida's longest hurricane-free stretch since records began in 1851. The previous longest hurricane-free streak in Florida was five years, set in 1980 - 1984.- Arthur was the strongest storm (Category 2 at landfall) to hit the U.S. since Hurricane Ike (also Category 2 at landfall) in 2008.- Strongest hurricane: Hurricane Gonzalo, 145 mph winds, 940 mb pressure.- Most damaging hurricane: Hurricane Gonzalo, $200 - $400 million damage in Bermuda.- Longest-lived named storm: Edouard, 7.75 days as a named storm.- The eight named storms were the fewest since 1997. - Vertical wind shear (200-850-mb) during July-September in the Caribbean (10-20°N, 90-60°W) was 11.3 meters per second, which was the strongest since 1986 (11.6 meters per second).- More ACE was accrued during October (30 units) than during August and September combined (29 units). The last time that this happened was 1963.- The pre-season forecasts made by the major forecast groups at NOAA, Colorado State, TSR, Penn State, Florida State, WSI, the UKMET office, and NC State all did well. These forecasts called for a near-average to below-average Atlantic hurricane season
Figure 2. Hurricane Gonzalo as seen from the International Space Station on October 16, 2014. At the time, Gonzalo was at peak strength, with 145 mph winds. Gonzalo was the first Atlantic hurricane to reach sustained winds of at least 145 mph since Hurricane Igor of 2010, and made it all the way to 50.7°N latitude as a hurricane, which is the farthest north a hurricane has made it since Hurricane Debby of 1982 (50.8N.) Its remnants battered the United Kingdom on October 21 with wind gusts exceeding 100 mph, and killed three people there. Image credit: Alexander Gerst.
Tropical Storm Hagupit forms in the Western Pacific
Over in the Western Pacific, typhoon season is still in swing, as Tropical Storm Hagupit has formed about 1500 miles east of the Philippines. Hagupit is expected to take advantage of very warm waters and low wind shear to intensify into a major Category 3 typhoon later this week. Hagupit may be a threat to the Philippines this weekend, as suggested by the 00Z Monday morning run of the European model, but the GFS model predicts that the storm will recurve to the north and miss the Philippines. Wunderground member CycloneOz has put together a 15-minute YouTube animation of all of the IR satellite imagery from the Atlantic this hurricane season.