Arlene to Zeta: A 2005 Hurricane Season Recap
May 22, 2005
By WeatherBug Meteorologist, Joe Bartosik and James West
Even though the end of the "regular" season occurred on November 30, the National Hurricane Center wrote the last chapter of the 2005 Atlantic Hurricane Season in early April. This officially closes the history book on a season that shattered record after record over a 6 month period.
A few of the records broken include the most named storms, most hurricanes, strongest hurricanes on record in the Gulf of Mexico (Rita), in the Atlantic Basin (Wilma), and the costliest natural disaster in U.S. history (Katrina).
Even before the season started last year, hurricane experts and forecasters predicted a very busy and likely record-setting year. The forecasters saw several meteorological factors that in past seasons led to active hurricane seasons.
One of the biggest factors included the water in the Atlantic, Gulf of Mexico and Caribbean. Before the season started, water temperatures were running more than 5 degrees warmer than normal. Additional factors that concerned forecasters included: lower than normal surface pressure; lack of shear-inducing westerly winds in the tropics; and strong thunderstorm clusters moving off of the central and western Africa coast. All of these ingredients combined provided the ideal ingredients for an active storm season.
Based on long-term (1950-2000) data, the Atlantic Basin produces an average of 10 named storms a season. Six of these storms become hurricanes and two of the six grow into "major" hurricanes, packing winds of at least 111 mph, or Category 3 on the Saffir-Simpson Hurricane Intensity Scale.
In 2005, a record 28 tropical storms formed, or more than two-and-a-half times the seasonal average. In fact, the number of hurricanes observed this season, a record 15, surpasses the number of named storms in an average season. Seven of which -- Dennis, Emily, Katrina, Maria, Rita, Wilma, and Beta - - grew into major hurricanes.
For the first time since conventional names were applied to storms in the early 1950`s, the National Hurricane Center had to use the Greek Alphabet (Alpha, Beta, Gamma, Delta, and Epsilon) to classify storms. This occurred when the predetermined list of storm names were exhausted when Wilma formed in mid-October.
Before this record-shattering season, the 1933 hurricane season held the distinction of being the most active on record. Early National Weather Service records show that 21 tropical storms formed that year, of which 10 became hurricanes, and 5 of those major hurricanes.
Numerous other individual, monthly and seasonal hurricane records were shattered during the 2005 hurricane season. The following month-by-month review gives a rundown of them:
Tropical Storms Arlene and Bret both formed during the month of June. This was the first time since 1986 that two storm formed in the month. It has only occurred 12 other times since 1851.
July 3, 2005: Cindy lasted only 4 days and reached Category 1 status, producing heavy rainfall and minor wind damage along the Gulf Coast.
July 5, 2005: Dennis forms making this date the earliest in which four tropical storms had developed in the Atlantic Basin.
July 16, 2005: Hurricane Emily, a borderline Category 4 - Category 5 with maximum sustained winds of 155 mph, becomes the strongest July hurricane in the Caribbean: a record set one week earlier on July 8 by 155-mph Hurricane Dennis.
July, 2005 ties the 1916 record of having two major hurricanes develop during the month of July.
July`s five named storms (Cindy, Dennis, Emily, Franklin, and Gert) broke the old record of four named storms for the month.
The seven storms that formed in June and July were the most ever recorded during this period.
August 7, 2005: Irene forms, making this date the earliest in which nine tropical storms had developed in the Atlantic Basin.
August 27, 2005: Hurricane Katrina`s pressure drops to 902 mb (26.61 in. Hg) as wind speeds top out at 175 mph, making Katrina the strongest Gulf of Mexico hurricane on record in terms of pressure and the fourth lowest barometric pressure on record for a hurricane in the Atlantic Basin.
August 29, 2005: Hurricane Katrina makes landfall in Buras, La. -- just south of New Orleans, and again along the Louisiana-Mississippi border, causing a record 30-foot storm surge, devastating much of the immediate Mississippi and Alabama coastlines. Storm surge also caused several New Orleans levees to break, flooding nearly 80 percent of the city.
September 21, 2005: Hurricane Rita surpasses Hurricane Katrina as the Gulf of Mexico`s strongest hurricane on record after a Air Force Reconnaissance plane measures a barometric pressure of 897 mb (26.49 in. Hg). This also makes Rita the third most intense hurricane on record in the Atlantic Basin after Gilbert (1988) and the 1935 Florida Keys Labor Day Hurricane. Katrina`s pressure now ranks as the fifth lowest.
Since naming tropical systems began in the 1950`s, 2005 was the second season to use the "R", "S", and "T" names: Rita, Stan, and Tammy. 1995 was the first with Roxanne, Sebastien, and Tanya.
For the first time, the "V" name was used: Vince. It became the season`s 11 th hurricane on October 9. 2005 ties 1995, 1950, 1916, and 1887 for having the second most number of hurricanes.
October 11, 2005: Vince becomes the first recorded tropical system to make landfall in Spain. Vince came ashore near Huelva as a tropical depression with winds of 35 mph.
October 17, 2005: Wilma becomes the first "W" storm. 2005 ties with 1933 season for the most number of named storms.
October 18, 2005: Wilma becomes the season`s 12`th hurricane, tying the 1969 record for the most number of hurricanes in a season.
October 18-19, 2005: Wilma undergoes "rapid intensification" in the northwest Caribbean. In 17 hours, the barometric pressure drops from 977mb (28.85 in. Hg) to an estimated 882 mb (26.10 in. Hg). Wilma surpasses 1988`s Hurricane Gilbert as having the lowest pressure ever recorded in an Atlantic Basin hurricane. This is also the first time three Category 5 hurricanes have occurred in one season.
October 21-22, 2005: Hurricane Wilma makes landfall on Cozumel island, and then near Cancun, Mexico, respectively, as a Category 4. It was the second time this season both locations directly impacted by a major hurricane.
October 22, 2005: Tropical Depression #25 becomes Tropical Storm Alpha, thus making the 2005 Atlantic Hurricane Season the most active on record.
October 24, 2005: Hurricane Wilma sets a new record for being the fourth major hurricane to make landfall along the U.S. coast in one season as it moved ashore near Cape Romano, Fla., with winds near 125 mph (Category 3).
October 30, 2005: Hurricane Beta becomes the seventh major hurricane of the season, which ties the record originally set in 1950 and most recently in 1961.
The six named storms in October, 2005 ties the monthly record set in 1950.
Zeta forms on December 30, 2005 becoming the latest storm ever to form in the Atlantic Basin.
In April, 2006, upon concluding it`s seasonal report, the NHC adds a record 28`th storm to the season. The report, based on a review of satellite imagery, indicates a tropical storm moved near the Azores between October 3-5, 2006.
History will record the 2005 Atlantic Hurricane Season as the costliest season ever with nearly $110 billion in damage. The season is also the deadliest since 1928 with nearly 1,500 lives lost, 1,200 of which due to Katrina alone.
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