2011 Atlantic hurricane season

2011 Atlantic hurricane season
Season summary map
Seasonal boundaries
First system formed	June 28, 2011
Last system dissipated	November 11, 2011
Strongest storm
Name	Ophelia
• Maximum winds	140 mph (220 km/h) (1-minute sustained)
• Lowest pressure	940 mbar (hPa; 27.76 inHg)
Seasonal statistics
Total depressions	20
Total storms	19
Hurricanes	7
Major hurricanes (Cat. 3+)	4
Total fatalities	118 total
Total damage	$17.39 billion (2011 USD)
Related articles
Timeline of the 2011 Atlantic hurricane season 2011 Pacific hurricane season 2011 Pacific typhoon season 2011 North Indian Ocean cyclone season
Atlantic hurricane seasons 2009, 2010, 2011, 2012, 2013

The 2011 Atlantic hurricane season was the second in a group of three very active Atlantic hurricane seasons, each with 19 named storms, tied with 1887, 1995, 2010, and 2012. The above-average activity was mostly due to a La Niña that persisted during the previous year. Of the season's 19 tropical storms, only seven strengthened into hurricanes, and four of those became major hurricanes: Irene, Katia, Ophelia, and Rina. The season officially began on June 1 and ended on November 30, dates which conventionally delimit the period during each year in which most tropical cyclones develop in the Atlantic Ocean. However, the first tropical storm of the season, Arlene, did not develop until nearly a month later. The final system, Tropical Storm Sean, dissipated over the open Atlantic on November 11.

Due to the presence of a La Niña in the Pacific Ocean, many pre-season forecasts called for an above-average hurricane season. In Colorado State University (CSU)'s spring outlook, the organization called for 16 named storms and 9 hurricanes, of which 4 would intensify further into major hurricanes. On May 19, 2011, the National Oceanic and Atmospheric Administration (NOAA) issued their pre-season forecast, predicting 12–18 named storms, 6–10 hurricanes, and 3–6 major hurricanes. Following a quick start to the season, NOAA subsequently increased their outlook to 14–19 named storms, 7–10 hurricanes, and 3–5 major hurricanes on August 4; CSU made no changes to the number of cyclones forecast throughout the year.

Many tropical cyclones affected land during the 2011 season; most impacts, however, did not result in a significant loss of life or property. On June 29, Arlene made landfall in Mexico near Cabo Rojo, Veracruz, causing over $223 million (2011 USD) damage and killing 22 people.^{[nb 1]} Tropical Storm Harvey moved into the coastline of Central America in mid-August, and three deaths were reported as a result. During the month of September, Tropical Storm Lee and Hurricane Nate moved into the central United States Gulf Coast and central Mexico, respectively; the former led to 18 deaths, and the latter caused 5 fatalities. As an extratropical cyclone, Lee caused significant damage in the form of flooding across the Northeast United States, especially in New York and Pennsylvania. The deadliest and most destructive cyclone of the season developed east of the Lesser Antilles on August 21. Hurricane Irene caused significant impact across some of the Caribbean Islands and United States Eastern Seaboard, leaving about $14.2 billion in damage and resulting in the name's retirement. Overall, the season resulted in 112 deaths and nearly $17.4 billion in damage.
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