2005 Atlantic hurricane season

A season far above normal

Pre-season outlooks expected an active year, but not this one. NOAA's May forecast called for 12 to 15 named storms, against a 1950 to 2004 average of about 10 named storms, 6 hurricanes and 2 to 3 major hurricanes. The season's accumulated cyclone energy, a measure that combines storm strength and duration, came to 245.3 in the site's archive calculation. The National Hurricane Center's season summary put the season's energy at roughly two and a half times the long-term mean.

The ocean was unusually warm. Sea surface temperatures across the Caribbean and tropical Atlantic were the warmest observed there, with anomalies above 1°C in the western tropical Atlantic and warm water extending through the Gulf of Mexico. ENSO was neutral, and an active phase of the Atlantic multidecadal oscillation, together with suppressed convection over the tropical Pacific, helped weaken the wind shear that normally limits development.

Steering shaped where the storms went. A persistent mid-level ridge over the eastern United States sat a little farther south and west than in 2004 and pushed hurricanes west into the Gulf of Mexico. The deep tropics between Africa and the Lesser Antilles produced several storms but only two hurricanes, Emily and Philippe, both weak there. Most of the season's power was concentrated closer to North America.

How the season unfolded

Tropical Storm Arlene formed near Honduras on June 8, crossed western Cuba and came ashore just west of Pensacola, Florida, on June 11. Tropical Storm Bret followed at the end of June over the Bay of Campeche. July then brought five named storms, a record for the month, and seven named storms had formed before August began. Hurricane Cindy became the season's first hurricane on July 6 near its landfall in southeastern Louisiana, while Hurricane Dennis and Hurricane Emily both became major hurricanes in the Caribbean.

The first half of August was comparatively quiet, as Tropical Storm Harvey and Hurricane Irene stayed over open water. The pace picked up late in the month with Tropical Storm Jose in Mexico and then Hurricane Katrina, which formed over the Bahamas on August 23. September produced five hurricanes, including Hurricane Maria, Hurricane Nate, Hurricane Philippe and Hurricane Ophelia, whose slow, erratic track off the North Carolina coast made it the longest-lived system in the site's records. Hurricane Rita closed the month in the Gulf of Mexico.

October stayed busy. Hurricane Stan struck Mexico early in the month, an unnamed subtropical storm passed near the Azores, and Tropical Storm Tammy moved up the southeastern U.S. coast. Hurricane Vince formed far to the east near Madeira, Hurricane Wilma became the season's strongest storm, and Tropical Storm Alpha and Hurricane Beta took the first Greek-letter names. Tropical Storm Gamma and Tropical Storm Delta followed in November, Hurricane Epsilon lasted into December, and Tropical Storm Zeta formed on December 30 and survived until January 6, 2006.

Four Category 5 hurricanes

2005 was the first season known to produce four Category 5 hurricanes. Hurricane Emily peaked first, at 140 kt and 929 hPa southwest of Jamaica on July 17, making it the first Category 5 hurricane on record in July. Hurricane Katrina reached 150 kt and 902 hPa over the Gulf of Mexico on August 28. Less than a month later, Hurricane Rita peaked at 155 kt and 895 hPa on September 22, also over the Gulf.

Hurricane Wilma outdid them all. Over the northwestern Caribbean it strengthened from a 60 kt tropical storm to a 150 kt Category 5 hurricane in about 24 hours, and aircraft measured a pressure fall of 88 hPa in roughly 12 hours. Its eye shrank to about 2 nautical miles across, the smallest known to NHC forecasters. At its peak on October 19, Wilma had one-minute winds of 160 kt and a central pressure of 882 hPa, below the 888 hPa of Hurricane Gilbert in 1988 and the lowest known in an Atlantic hurricane.

The other three major hurricanes were Hurricane Dennis, which reached 130 kt south of Cuba on July 8, and Hurricane Maria and Hurricane Beta, which each peaked at 100 kt. Rapid strengthening was a recurring feature: Rita's pressure fell 70 hPa in about 24 hours, Katrina's fell 46 hPa, and Dennis went through two bursts of rapid deepening.

Landfalls and impacts

Hurricane Dennis struck southeastern Cuba as a Category 4 hurricane on July 8, hit Cuba again later that day and crossed much of the island before making landfall on Santa Rosa Island, Florida, at 105 kt on July 10. NHC attributed 42 direct deaths to Dennis, 22 of them in Haiti and 16 in Cuba. Hurricane Emily made two major-hurricane landfalls in Mexico, on the Yucatán Peninsula on July 18 and in Tamaulipas on July 20.

Hurricane Katrina crossed southern Florida as a Category 1 hurricane on August 25, then made landfalls near Buras, Louisiana, and near the Louisiana–Mississippi border on August 29, both at Category 3. Its storm surge flattened much of the Mississippi coast, and levee and floodwall failures left about 80% of New Orleans under water. NHC's 2023 revision counts 1,392 fatalities in the United States: 520 direct, 565 indirect and 307 of undetermined cause. It estimates U.S. damage at $125 billion in 2005 dollars.

Hurricane Rita came ashore just east of Sabine Pass, at the Texas–Louisiana border, on September 24 with 100 kt winds. The threat prompted one of the largest evacuations in U.S. history, possibly more than two million people in Texas alone, and its surge destroyed almost every structure in several Cameron Parish communities. NHC counted seven direct deaths and at least 55 indirect deaths in Texas, including more than 20 evacuees killed in a bus accident near Dallas.

Hurricane Stan made landfall in Mexico in early October, but the worst impacts came from a broader rain-bearing circulation around it. Mexico reported 80 deaths in Veracruz, Oaxaca and Chiapas, which NHC set as Stan's direct toll, while floods across eastern Mexico and Central America killed an estimated 1,000 to 2,000 people, possibly more than 1,000 in Guatemala alone. Late-season storms added to the losses in the region: floods and mudslides with Tropical Storm Alpha killed 26 people in Haiti and the Dominican Republic, and floods linked to Tropical Storm Gamma killed 37 in Honduras and Belize.

Hurricane Wilma struck Cozumel and the northeastern Yucatán Peninsula as a Category 4 hurricane on October 21 and 22, moving slowly enough to batter the area for about a day. It then accelerated northeast and made landfall near Cape Romano, Florida, at 105 kt on October 24, crossing the peninsula in about four and a half hours. NHC attributed 23 direct deaths to Wilma, including 12 in Haiti and 5 in Florida. The damage swath in South Florida was unusually wide, and Wilma caused the largest disruption to electrical service Florida had experienced.

Records, Greek letters and retired names

2005 was the first Atlantic season to use every name on its regular list of 21. Tropical Storm Alpha was the first Atlantic storm named from the Greek alphabet, and the list ran on to Tropical Storm Zeta, the 27th named storm of the year. Zeta and Hurricane Alice of 1954 are the only Atlantic tropical cyclones on record to cross from one calendar year into the next.

The late season was unusually far-flung. Hurricane Vince became a hurricane farther east than any other known Atlantic cyclone and was the first known tropical cyclone to reach the Iberian Peninsula, coming ashore in Spain near Huelva on October 11 as a depression. Hurricane Epsilon spent five days as a hurricane in December, a record for that month. Tropical Storm Delta's extratropical remnants brought damaging winds to the Canary Islands, where seven people died.

In spring 2006 the World Meteorological Organization retired five names from the season, Dennis, Katrina, Rita, Stan and Wilma, the most from any single Atlantic season. The same committee decided the Greek alphabet would be used again if needed, a practice later abandoned after the 2020 season.

NHC's season summary, based on the HURDAT best track, agrees with the totals here: 28 storms, 15 hurricanes and 7 major hurricanes. One of the 28, the unnamed October system near the Azores, was a subtropical storm, which the site counts alongside tropical storms because both use U.S.-agency one-minute winds of at least 34 kt. Two tropical depressions and a subtropical depression never reached that strength; they appear on the map but not in the counts.