Colorado State University Review Finds 2005 Hurricane Season ‘Most Active, Destructive’ on Record

A list of the 2005 hurricane season’s most unique characteristics and facts has been released by Colorado State University. A CSU statement said that the just-completed hurricane season was the most active and destructive one on record. Seasonal characteristics and records include:

* 25 named storms formed during the 2005 season. This is the most named storms in a single season, breaking the old record of 21 named storms set in 1933. However, there was no satellite coverage during 1933, and it is quite possible that there may have been one or more storms that were missed during the 1933 season.

* 13 hurricanes formed during the 2005 season. This is the most hurricanes in a single season, breaking the old record of 12 hurricanes set in 1969.

* 7 intense or major (categories 3, 4 or 5) hurricanes formed during the 2005 season. This ties the single-season record for intense hurricanes set in 1950.

* Three Category 5 hurricanes formed during the 2005 season (Katrina, Rita and Wilma). This is the most Category 5 hurricanes recorded in a single season, breaking the old record of two, set in 1960 and 1961. Also, when the 2004-2005 seasons are combined, four Category 5 hurricanes have formed (Ivan, Katrina, Rita and Wilma). This ties the consecutive-year record set in 1960-1961 when four Category 5 hurricanes also formed.

* Seven named storms made U.S. landfall during 2005 (Arlene, Cindy, Dennis, Katrina, Rita, Tammy and Wilma). This puts the 2005 season in a tie for second place for landfalling storms, behind the 1916 and 2004 seasons when eight named storms made landfall.

* The 2005 season was the most damaging in history for U.S. landfalling storms, largely due to Hurricane Katrina. Insured damage estimates for the 2005 season reached nearly $70 billion, which shatters the old records set in 1992 and 2004, which, when adjusted for inflation, were each approximately $25 billion in insured damage.

Monthly characteristics/records

The following is a list of characteristics of the individual months of the 2005 season, along with records that were set. Monthly records for this evaluation began in 1950.

June

* Two named storms formed (Arlene and Bret). Only 1957, 1959, 1968 and 1986 have had two or more named storms form during the month of June.

July

* Five named storms formed (Cindy, Dennis, Emily, Franklin and Gert). This is the most on record for the month.

* Two major hurricanes formed (Dennis and Emily). This is the most on record.

August

* Five named storms formed (Harvey, Irene, Jose, Katrina and Lee). Only 1990, 1995 and 2004 have had more than five named storms form during the month of August.

September

* Five hurricanes formed (Maria, Nate, Ophelia, Philippe and Rita). This ties 1955, 1969, 1981, 1998 and 2000 for the most hurricanes to form during the month of September.

October

* Six named storms formed (Stan, Tammy, Vince, Wilma, Alpha and Beta). This ties 1950 for the most named storm formations during the month of October.

* Four hurricanes formed (Stan, Vince, Wilma and Beta). Only 1950 had more hurricanes develop during the month of October.

* Two intense hurricanes formed (Wilma and Beta). This ties 1950, 1961, 1964 and 1995 for the most intense hurricanes to form during the month of October.

* Five intense hurricane days occurred. Only 1954 and 1961 recorded more intense hurricane days.

November

* Tropical Storm Gamma formed Nov. 18, creating the 24th named storm of the season, and Tropical Storm Delta formed Nov. 23, the 25th storm of the season.

Individual storm characteristics/records

Some notable characteristics/records set by storms occurring during the 2005 season:

* Dennis became the most intense hurricane on record before August, when a central pressure of 930 mb was recorded.

* Emily eclipsed the record previously set by Dennis for lowest pressure recorded for a hurricane before August, when its central pressure reached 929 mb.

* Katrina’s central pressure dropped to 902 mb. At the time, it was the fourth lowest pressure ever measured in the Atlantic basin.

* Katrina’s central pressure at landfall was 918 mb. This is the third lowest pressure recorded at landfall behind the Florida Keys storm of 1935, 892 mb; and Hurricane Camille of 1969, 909 mb.

* Katrina became the most destructive storm on record with an estimated $50 billion dollars in insured damage. This shatters the old record of approximately $25 billion (normalized to 2005 dollars) in insured damage set by Hurricane Andrew (1992).

* Rita’s central pressure dropped to 897 mb. At the time, it was the third lowest pressure ever measured in the Atlantic basin.

* Vince was the furthest north and east that a storm has ever developed in the Atlantic basin.

* Vince was the first tropical cyclone in recorded history to strike the Iberian Peninsula.

* Wilma reached Category 5 intensity. Wilma was the third Category 5 of the season. This is the first time that three Category 5 storms have formed in one year, breaking the record of two Category 5 storms set in 1960 and equaled in 1961.

* Wilma’s central pressure dropped to 882 mb. It was the lowest pressure ever measured in the Atlantic basin, eclipsing the old record of 888 mb set by Hurricane Gilbert (1988).

* Alpha became the 22nd named storm of the 2005 season. This breaks the old record of 21 named storms set in 1933.

* Beta became the 13th hurricane of the 2005 season. This breaks the old record of 12 hurricanes set in 1969.

* Gama became the 13th hurricane of the 2005 season.

* Epsilon became the 14th hurricane of the 2005 season.