Musings: December Marks End to Active 2008 Hurricane Season
December 1st ended the 2008 hurricane season, which marked another year characterized by above-normal activity for tropical storms. The Atlantic Basin experienced 16 named storms during the 2008 season, which included two intense storms -- Gustav and Ike -- that caused significant damage to the U.S. Gulf Coast and its oil production infrastructure. Of the 16 tropical storms this year, eight were hurricanes while five were major hurricanes. This year was the 10th in the past 14 years to produce above-normal storm activity.
People will be anxiously awaiting the early forecasts for tropical storm activity in 2009 as oil industry participants are becoming accustomed to having to plan for the potential of disruption to drilling and production activity in the Gulf of Mexico. The petroleum industry had barely restored all its damaged producing capacity from 2005 hurricanes Katrina and Rita when it was hit by a series of storms this past year from which it has still not fully recovered. The early forecasts for 2009 will be issued by the various prediction centers starting in mid December.
The track of the 16 named storms experienced in 2008 is displayed in Exhibit 1.
The colors of the tracks reflect the level of the storm during that portion of its travel from formation to the ending of its tropical storm level.
Examining what happened during 2008’s hurricane season provides some interesting perspective on where in the tropical storm cycle we are currently operating. This season started early as Arthur formed on May 31. During the years 1944-2005, the average date for formation of the season’s first named tropical storm is July 10th.
This season saw a total of 16 named storms. Since 1995, 13 of the last 14 storm seasons have experienced more than the historic average (1950-2000) of 10 named storms. Since aircraft reconnaissance began in 1944, only 2005 with 28 named storms, 1995 with 19 named storms and 1969 with 18 named storms have had more than the 16 named storms of 2008. The eight hurricanes experienced in 2008 exactly equaled the average number of hurricanes experienced during the period 1995-2007. The five major hurricanes of 2008 have only been exceeded seven times since 1944.
There were 84.75 named storm days during 2008, which was more than twice the number experienced in 2007 despite there being only one additional named storm. This was the seventh highest seasonal total of named storm days since 1944. The 29.50 hurricane days experienced in 2008 was also more than two times the number in 2007. Amazingly, there were no Category 3, 4 or 5 hurricanes making landfall in 2008. This was only the second year since 2002 with no Category 3 or greater storm with the other year devoid of major landfalling hurricanes being 2006.
After having an early start to the 2008 hurricane season, the fall was particularly active, too. There were three named storms in October. There have only been eight years since 1944 that have had more than three named storms in October. Since 1944, there have been only four other years with a major hurricane. Those other four years included 1956 (Greta), 1985 (Kate), 1999 (Lenny) and 2001 (Michelle). Hurricane Paloma (Category 4) was the second strongest November tropical storm ever with a maximum sustained wind speed of 145 miles per hour trailing Hurricane Lenny that attained 155 mph winds.
This year was the first year on record with five consecutive months (July through November) that had a tropical storm that achieved major hurricane intensity. This record reflects just how unique was the 2008 tropical storm season. There were three hurricanes that landed on the U.S. Gulf Coast, which was the most since 2005 when four hurricanes landed.
Prior to 2005, the previous year with three or more hurricanes making U.S. landfall on the Gulf Coast was in 1985 with four storms. Interestingly, there were no hurricanes making landfall along the Florida peninsula and the East Coast of the United States. This marked the third year in a row without a hurricane hitting this region. There were six named storms in row, Dolly through Ike, making landfall on the U.S. coast, matching the record achieved in five prior years -- 1971, 1979, 1985, 2002 and 2004.
Hurricane Bertha, a July tropical storm that reached Category 3 hurricane status, remained a tropical storm or greater for 17 days (July 3-20), which was the longest-lived July tropical storm on record in the Atlantic Basin. Tropical storm Fay in August made landfall on the Florida peninsula four times that also set a record.
One of the better forecasts made for the 2008 season was that of Phil J. Klotzbach and William M. Gray, professors in the Department of Atmospheric Science at Colorado State University. The record of all their 2008 tropical storm forecasts is presented in Exhibit X. As can be seen their forecasts from December 2007 through August 2008 proved fairly accurate. In most cases the forecasts made in April, which were only increased in the August forecast update after part of the season had already been experienced, were pretty close to the actual results for the year. For example, the CSU forecast was upped to 15 named storms, eight hurricanes and four intense hurricanes, which compared with actual results of 16, eight and five. The CSU forecast for named storm days (80) and intense hurricane days (9) were very close to actual results of 84.75 named storm days and 8.50 intense hurricane days. The forecast for the number of hurricane days of 40 was quite wide of the actual total of 29.50 days. But when all the forecasting variables are assessed, one has to tip their hat to the forecasting team at CSU for the accuracy of their efforts. We will be very interested in their December 10th forecast for 2009’s hurricane season.