2011 Atlantic hurricane season in review

The forecasts for the 2011 Atlantic hurricane season were fairly  accurate. 2011 will go down as one of the most active seasons in recorded history.  

The 2011 Atlantic hurricane season provided us a total of 19 named storms of which seven became hurricanes, including three major hurricanes.  The season officially ended on November 30, 2011, and will go down as one of the most active seasons in recorded history.  The 2011 season is actually tied for the third most-active hurricane season since 1851, when record keeping began.  2011 was tied with 1887, 1995, and 2010. Meanwhile, 2005 and 1933 are the most active hurricane seasons on record.

Here’s a 4.5 minute recap of the 2011 Atlantic Hurricane Season:

The National Oceanic and Atmospheric Administration (NOAA) and Colorado State University forecasts for the 2011 Atlantic hurricane season were fairly  accurate. Every year around May and early June, these two main contributors release their thoughts on the upcoming season.  They calculate named storms (tropical storms), hurricanes, and major hurricanes (Category 3+).  They also include an index called ACE, or accumulated cyclone energy.  ACE measures the intensity and duration of named storms and hurricanes during the season.  An average ACE index typically falls between 71-111. An above normal ACE value lies between 111-165, and any value over 165 indicates a hyperactive season.

The 2011 Atlantic hurricane season weighed more on quantity than quality of storms.  In other words, many of the storms that formed were rather weak and never developed into significant storms due to dry air, wind shear, or other inhibiting factors.  In the beginning of the season, dry air was a huge issue for systems to develop.  If you asked anyone around you about this hurricane season, they would likely tell you that it was quiet.  We could see five storms form with one major hurricane hitting the United States and it makes the entire season go from quiet to active.

Let’s take a look at all of the named storms that developed in the Atlantic ocean in 2011:

Tropical Storm Arlene on June 30, 2011. Image Credit: NOAA GOES Project

Tropical Storm Arlene
Arlene formed on June 29, 2011 and dissipated on July 1, 2011.  It had a slim shot at hitting hurricane strength, but interaction with land prevented it.  Arlene had maximum wind speed of 65 miles per hour, 9 mph below hurricane strength (74 mph).  Arlene hit the northeast coast of Mexico south of Tampico.  Brownsville, Texas received some beneficial rain from this system,  but most of the rains were confined in Mexico where some areas saw four to six inches of rain.

Bret and Cindy on July 21, 2011. Image Credit: NASA/NOAA GOES Project

Tropical Storm Bret and Cindy
Bret formed on July 17, 2011, with tropical storm Cindy forming three days later on July 20, 2011.  Bret peaked as a 65 mph storm with a pressure of 996 millibars (mb).  Cindy peaked at 60 mph with a pressure reading of 1000 mb.  Bret formed over the northern Bahamas and eventually moved out to sea as a trough pushed it away from the United States.  Cindy formed 600 miles east of Bermuda and did not affect anyone as it moved out to sea.

Tropical storm Don on July 28, 2011. Image Credit: NASA/NOAA GOES

Tropical Storm Don
Don formed in the Gulf of Mexico on July 27, 2011.  Don was the best shot for Texas to see beneficial rain, however, the drought got the best of Don.  As Don made landfall in Baffin Bay, Texas as a weak and disorganized tropical storm.  Don had maximum wind speeds of 50 mph with a pressure of 998 mb.  Dry air from Texas disrupted the storm completely as it made landfall. Dry air was so significant that it actually destroyed the system in a blink of an eye! The National Hurricane Center actually joked about Don and stated:

THE DON IS DEAD. THE CYCLONE LITERALLY EVAPORATED OVER TEXAS ABOUT AS FAST AS I HAVE EVER SEEN WITHOUT MOUNTAINS INVOLVED. DON HAS NO CONVECTION…MEAGER RAINFALL…AND ONLY A SLIGHT SIGNATURE IN SURFACE OBSERVATIONS AND RADAR DATA. THEREFORE…THIS IS THE LAST ADVISORY ON THIS SYSTEM.

People from Texas are not too fond with Don, needless to say!

Tropical storm Emily on August 6, 2011. Image Credit: NASA Goddard MODIS Rapid Response Team

Tropical Storm Emily
Emily formed on August 6, 2011 and became a minimum tropical storm.  Emily affected parts of Hispaniola and produced heavy rain in the area.  The storm was not severe, and was eventually steered to the north from an incoming trough moving off the east coast of the United States.  The biggest threat was heavy rain across Haiti with estimates of 4-8 inches across the area. Emily did not impact the United States.

 

Tropical storm Franklin on August 13, 2011. Image Credit: NASA/NOAA GOES Project

Tropical Storm Franklin
Franklin formed on August 12, 2011 north of Bermuda in the open Atlantic waters. Franklin did not last long because it was over open waters that were cooling below the threshold to maintain a tropical system.  If satellites did not exist, this storm would have easily been forgotten and never seen.

 

Tropical storm Gert on August 14, 2011. Image Credit: NOAA

Tropical Storm Gert
Gert formed on August 14, 2011 and had maximum sustained winds of 60 mph with a pressure of 1000 mb.  Gert formed near Bermuda, but did not have any significant impacts on the island as it pushed north away from land and into the deep Atlantic ocean.  Once again, another tropical storm had formed in the Atlantic Ocean, but not a single hurricane developed within this time span.

 

Tropical storm Harvey on August 19, 2011. Image Credit: NASA/NOAA GOES Project

Tropical Storm Harvey
Harvey formed on August 19, 2011 and had maximum sustain winds of 60 mph with a pressure of 994 mb.  Harvey made landfall into Belize and produced heavy rains across the area.  Northern Guatemala and Honduras received heavy rain as well with rainfall estimates around six to eight inches. The formation of Harvey made 2011 the first hurricane season since record keeping began in 1851 to have more than six consecutive tropical storms that did not reach hurricane strength. All of that ended when the “I” storm formed: Hurricane Irene.

Hurricane Irene on August 24, 2011. Image Credit: NASA Goddard MODIS Rapid Response

Major Hurricane Irene
Irene formed on August 20, 2011 in the middle of the Atlantic ocean.  Irene eventually became the first hurricane and first major hurricane of the 2011 Atlantic hurricane season with maximum sustain winds of 120 mph and a pressure of 942 mb. Irene was a Cape Verde storm, meaning it formed off the coast of Africa and pushed westward toward the United States.  Irene was a very large storm, with a barometric pressure typical for a Category 4 storm at it’s peak strength.  Irene pushed into the Bahamas and brought heavy rain and flooding across the region. The National Hurricane Center did a fantastic job with the track of Irene.  They knew the system would impact parts of the United States, and many feared Irene would hit New York City.  Fortunately, Irene weakened into a tropical storm by the time it hit parts of New England.  Forecasting the intensity of Irene was rather difficult, as the original forecasts were showing a hurricane hitting New England.  However, dry air, wind shear, and cooler sea surface temperatures slowly weakened the system.  Irene ultimately left over three million people without power, and killed 55 people.  Hurricane Irene became the 10th billion dollar disaster for the United States, with total estimates around 7.2 billion dollars in damage.  For more information regarding Irene, check out EarthSky’s post on the history of Irene. 

Tropical storm Jose on August 28, 2011. Image Credit: NASA/NOAA GOES Project

Tropical Storm Jose
Jose formed on August 28, 2011 and had maximum sustain winds of 45 mph with a pressure of 1007 mb.  Jose formed behind Irene and passed west of Bermuda.  The interaction of Irene resulted in high wind shear that disrupted the organization of Jose. Jose dissipated on August 29, 2011 as wind shear was too much for the system.  Jose is another storm that was classified, but if satellites were not around, we would have ignored this system.  2011 was becoming quantity over quality, which is a good thing for the United States.

Major Hurricane Katia, Tropical Storm Lee, Hurricane Maria, and Tropical Storm Nate
Katia formed on August 29, 2011 in the eastern Atlantic around the Cape Verde Islands. Katia eventually strengthened as a major hurricane with sustain maximum winds of 135 mph with a pressure of 946 mb. Katia moved in between Bermuda and the eastern United States, but it never impacted anyone. Kata eventually recurved to the northeast and dissipated on September 10, 2011.

Tropical Storm Lee
Lee formed on September 2, 2011 in the northern Gulf of Mexico. It made landfall on the southern coast of Louisiana on September 4, 2011. It had a fairly low pressure reading of 986 mb for a tropical storm, and had maximum sustain winds of 60 mph. Lee produced two extremes across the United States. It brought very gusty winds across the drought stricken areas of Texas, resulting in wildfires across the state. To the east of the system, it was producing heavy, flooding rains with chances of isolated tornadoes. Lee produced around 10 inches of rain across portions of Louisiana and Mississippi as it moved to the northeast. Tropical storm Lee produced heavy rains across Pennsylvania as it pushed into New England with totals over 10 inches in some areas. For more information regarding Tropical Storm Lee, check out our post on EarthSky!

Hurricane Maria
Maria formed on September 6, 2011 and peaked as a 80 mph hurricane with a pressure of 979 mb. Maria formed in the central Atlantic ocean, and pushed towards the west-northwest as a tropical storm for most its life. Maria brushed through the Lesser Antilles and began to pull further north. Once again, another trough was moving off the eastern coast, which pushed the storm away from the United States. It eventually moved west of Bermuda, but it did produce a few bands of storms across the island. Maria actually strengthened into a hurricane when it was north of Bermuda, and transitioned away from tropical characteristics (warm-core) to become extratropical.

Tropical Storm Nate
Nate formed in the Bay of Campeche in the southern Gulf of Mexico on September 7, 2011. It slowly pushed to the west into Mexico and had peak winds of 70 mph with a pressure of 994 mb. Nate made landfall north of Barra de Nautla in the Mexican state of Veracruz, as a tropical storm with 45 mph winds. Nate encountered wind shear and dry air from the west, which disrupted the organization of the entire system. It might be possible that the National Hurricane Center could re-classify this storm as a hurricane in the near future, but for now, it remains as a strong tropical storm. Nate weakened considerably as it pushed into Mexico, which resulted in moderate rain across the region, but nothing that caused significant flooding in the area.

Hurricane Ophelia on October 1, 2011. Image Credit: NASA Goddard MODIS Rapid Response Team

Major Hurricane Ophelia
Ophelia formed on September 21, 2011 across the central Atlantic. Ophelia became the strongest hurricane of the season as it reached maximum sustain winds of 140 mph with a pressure of 940 mb on October 2, 2011. Ophelia pushed just east of Bermuda (poor Bermuda!), where it strengthened into a major hurricane. Ophelia eventually pushed north and made landfall in Camp Race, Newfoundland on October 3, 2011 as a weakening tropical storm. Ophelia was accelerating in speed by the time it hit Newfoundland, so rainfall totals were under two inches in many areas. Ophelia dissipated and lost tropical characteristics later that day on October 3, 2011.

 

Hurricane Philippe on October 6, 2011. Image Credit: NASA Goddard MODIS Rapid Response Team

Hurricane Philippe
Philippe formed on September 24, 2011 south of the Cape Verde Islands in the eastern Atlantic ocean. Philippe was never a threat to any land areas, as it stayed out in the open Atlantic waters. Philippe was a relatively small storm, and wind shear and dry air impacted it for most of its lifetime. Late in its life, Philippe became a hurricane with maximum sustain winds of 90 mph with a pressure reading of 976 mb. Once again, another trough absorbed Philippe and the system pushed out to the northeast.

 

Hurricane Rina on October 26, 2011. Image Credit: NASA Goddard MODIS Rapid Response Team

Hurricane Rina
Rina formed on October 23, 2011 in the southwest Caribbean. Heat content in this area was very warm, and it allowed Rina to intensify from a tropical depression to a hurricane in just 21 hours. Rina became the second fastest storm to intensify in the Atlantic since record keeping began in 1851. At maximum strength, Rina was a Category 2 storm with maximum sustained winds of 110 mph and a pressure of 966 mb. Rina pushed to the north and skirted parts of the Yucatan Peninsula. Wind shear from a frontal boundary significantly hindered the storm, and Rina dissipated in the southern Gulf of Mexico. Some of the remnants of Rina were actually picked up from the frontal boundary and parts of the east coast received soaking rains from this sytem. In facts, the moisture from Rina was absorbed in the area of low pressure that brought a huge snowstorm across New England on October 29, 2011.

 

Tropical Storm Sean on November 7, 2011. Image Credit: NASA Goddard MODIS Rapid Response Team

Tropical Storm Sean
Sean, which became the 19th named storm of the 2011 Atlantic hurricane season, formed on November 8, 2011. Sean became a tropical storm with maximum wind speeds of 65 mph with a pressure of 983 mb. Sean formed in the open waters in the western Atlantic between the Lesser Antilles and Bermuda. Sean pushed just west of Bermuda. Bermuda had a few wind gusts over 50 mph from the storm, but wind shear significantly weakened Sean, and rainfall totals were very light across the island. Sean was the last named storm for the 2011 season.

 

 

Unnamed Tropical Storm (recently added)
The National Hurricane Center classified an unnamed storm as a tropical storm back on September 1, 2011. This “Unnamed” tropical storm had maximum wind speeds of 45 mph with a pressure of 1002 mb. The system formed southwest of Bermuda, but eventually pushed northeast towards Nova Scotia.

For more great information on the 2011 Atlantic hurricane season, please visit the National Hurricane Center and Weather Underground.

Overall, the 2011 Atlantic hurricane season was very active producing 19 named storms, seven hurricanes, and three major hurricanes. It was tied for the third most active in the Atlantic ocean, sharing the title with 1887, 1995, and 2010. 2011 brought quantity instead of quality, which was great news for the United States, Mexico, Cuba, Bermuda, and the Lesser Antilles. The strongest storm to impact land was Hurricane Irene, which became the 10th billion-dollar disaster for the United States as it brought extreme flooding to many regions across North Carolina and points north to New England. Hurricane season started on June 1, 2011 and ended on November 30, 2011. Although the season has officially ended, it does not mean we cannot see tropical development in the month of December. It is a rare event if we do, but it is always possible. Honestly, I think this season has really come to an end as ocean temperatures have cooled, and the only areas supportive of tropical development is in the Caribbean. Once again, it might have seemed like we had a “quiet” hurricane season in 2011. But in reality, 2011 was a very active hurricane season, even though the storms were mostly weak and below hurricane status.

Matt Daniel

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