User:Cyclonebiskit/2009 Atlantic hurricane season

The 2009 Atlantic hurricane season was a below-average year, unlike the 2009 Pacific hurricane season, which was above average, both due to a moderate El Niño. During this year, nine tropical storms formed, the fewest since the 1997 season. Although Tropical Depression One formed on May 28, the season officially began on June 1, 2009 and ended on November 30. The season's last storm, Hurricane Ida dissipated on November 10. The season had eleven tropical depressions, of which nine intensified into tropical storms, three became hurricanes, and two became major hurricanes. The inactivity throughout the basin was linked to the formation of an El Niño, which increased wind shear. The two most significant storms of the season, in terms of loss of life and damage, were Hurricanes Bill and Ida. Hurricane Bill was an unusually large storm and was also the season's strongest, attaining winds of 135 mph (215 km/h).

Throughout the basin, six people were killed in tropical cyclone-related incidents and total losses reached roughly $77 million. Of the season's eleven cyclones, five made landfall during their existence. Hurricane Bill caused moderate coastal damage across the eastern United States before brushing Nova Scotia and making landfall in Newfoundland. Significant damage took place in Atlantic Canada as a result of Bill as well. The only storm to make landfall as a tropical cyclone in the United States, Tropical Storm Claudette, caused minor wind and water damage during its brief life in the eastern Gulf of Mexico. In combination with a stronger extratropical system, Tropical Storm Danny caused roughly $25 million in damage throughout Nova Scotia and Newfoundland. In early September, Tropical Storm Erika passed over the island of Guadeloupe, producing moderate rainfall but little damage. Hurricane Ida was the only storm of the season to make landfall at hurricane intensity, crossing the Nicaraguan coastline with winds of 80 mph (130 km/h).

Seasonal forecasts
Forecasts of hurricane activity are issued before each hurricane season by noted hurricane experts Philip J. Klotzbach, William M. Gray, and their associates at Colorado State University; and separately by NOAA forecasters.

Klotzbach's team (formerly led by Gray) defined the average number of storms per season (1950 to 2000) as 9.6 tropical storms, 5.9 hurricanes, 2.3 major hurricanes (storms reaching at least Category 3 strength in the Saffir-Simpson Hurricane Scale) and ACE Index 96.1. NOAA defines a season as above-normal, near-normal or below-normal by a combination of the number of named storms, the number reaching hurricane strength, the number reaching major hurricane strength and ACE Index.

Pre-season forecasts
On December 10, 2008, Klotzbach's team issued its first extended-range forecast for the 2009 season, predicting above-average activity (14 named storms, 7 hurricanes, 3 of Category 3 or higher and ACE Index of 125). On April 7, 2009, Klotzbach's team issued an updated forecast for the 2009 season, predicting near-average activity (12 named storms, 6 hurricanes, 2 of Category 3 or higher and ACE Index of 100), citing the possible cause as the high probability of a weak El Niño forming during the season. On May 21, 2009, NOAA issued their forecast for the season, predicting near or slightly above average activity, (9 to 14 named storms, 4 to 7 hurricanes, and 1 to 3 of Category 3 or higher).

Midseason outlooks
On June 2, 2009, Klotzbach's team issued another updated forecast for the 2009 season, predicting slightly below average activity (11 named storms, 5 hurricanes, 2 of Category 3 or higher and ACE Index of 85). On June 18, 2009, the UK Met Office (UKMO) issued a forecast of 6 tropical storms in the July to November period with a 70% chance that the number would be in the range 3 to 9. They also predicted an ACE Index of 60 with a 70% chance that the index would be in the range 40 to 80. On August 4, 2009, Klotzbach's team updated their forecast for the 2009 season, again predicting slightly below average activity (10 named storms, 4 hurricanes, and 2 major hurricanes). On August 6, 2009, the NOAA also updated their forecast for the 2009 season, predicting below average activity (7–11 named storms, 3–6 hurricanes, and 1–2 major hurricanes).

May–July
In mid-May, a tropical disturbance developed over the Caribbean Sea. The system initially tracked north before turning westward into the Gulf of Mexico. On May 22, a Hurricane Hunter reconnaissance aircraft flew into the system to determine whether or not it had developed into a tropical depression. Hours before moving over the United States Gulf Coast, the NHC stated that the system was likely to become a tropical cyclone; however, this development did not take place, although sustained winds reached 35 mph (55 km/h) at its strongest. The low made landfall near the Alabama-Mississippi border midday on May 22 before dissipating over land.

The first official tropical cyclone of the 2009 Atlantic season formed out of a low pressure system off the coast of South Carolina on May 26. Slowly turning northeastward, the system steadily gained tropical characteristics, developing deep convection during this time. During the afternoon of May 28, the low had become sufficiently organized for the NHC to designate it as Tropical Depression One. Upon becoming a tropical depression, it marked the furthest north a tropical cyclone had developed during the month of May. Increasing wind shear eventually caused the depression to weaken, resulting in it degenerating into a remnant low pressure area on May 30. The remnants were absorbed by a warm front several hours later.

Several hours after Tropical Depression One formed, satellites began monitoring a new low pressure system over the central-north Atlantic. Initially extratropical, the storm gradually became better organized as it tracked westward. Late on June 1, the cyclone had begun to acquire subtropical characteristics, and sustained winds reached 40 mph (65 km/h). The following day, the low attained an intensity with winds of 50 mph (85 km/h) and a barometric pressure of 995 mbar (hPa; 29.38 inHg). Shortly thereafter, the system turned eastward and weakened. It eventually lost its hybrid characteristics on June 4 before losing its identity north of the Azores on June 5. Although the NHC classified the system as a non-tropical low, there was a possibility for the cyclone to be reclassified as a subtropical storm during post-season analysis; however, this did not occur.

August
After over two months without tropical cyclone development, the season's second tropical depression developed out of a tropical wave on August 11 over the extreme eastern Atlantic, near the Cape Verde Islands. The following day, the system briefly reached tropical storm status, although the storm was not operationally named at this point as it was initially thought to have remained a tropical depression. The post-season upgrade was based on sustained deep convection which was initially overlooked. However, this convection diminished shortly thereafter before the system degenerated into a remnant low on August 13. The next day, convection redeveloped around the cyclone and the system regenerated into a tropical depression. Several hours later, the depression intensified into Tropical Storm Ana, attaining its peak intensity at this time. Rapidly tracking westward, the storm began to weaken once more. On August 16, Ana was downgraded to a tropical depression before degenerating into a tropical wave east of the Lesser Antilles. Operationally, Ana was maintained as a tropical storm as it moved into the Caribbean Sea, with the final advisory from the NHC being issued on August 18 when the system was situated south of Puerto Rico.

As Ana regenerated into a tropical depression, a new tropical depression developed early on August 15 southwest of the Cape Verde Islands. Light wind shear and warm waters allowed the depression to steadily intensify, becoming Tropical Storm Bill later that day. By August 17, Bill attained hurricane-status about midway between the Cape Verde Islands and the Lesser Antilles. Eventually the hurricane attained its peak intensity as a Category 4 storm roughly 345 mi (555 km) east-northeast of the Leeward Islands. The storm attained maximum winds of 135 mph (215 km/h), the highest of any storm during the season, before weakening slightly as it turned north. The large storm passed roughly 175 mi (280 km) west of Bermuda as a Category 2 hurricane. Further weakening took place as Bill brushed the southern coast of Nova Scotia the following day. Shortly before making landfall in Newfoundland, Bill weakened to a tropical storm and accelerated. The storm eventually transitioned into an extratropical cyclone after moving over the north Atlantic before being absorbed by a larger non-tropical low on August 24.

In addition to Tropical Storms Ana and Bill tracking through the Atlantic Ocean on August 16, a new tropical depression formed over the eastern Gulf of Mexico. This depression quickly intensified into Tropical Storm Claudette as it neared the Florida Panhandle. The storm attained a peak intensity of 60 mph (95 km/h) offshore but quickly weakened as it neared land. Claudette made landfall early on August 17 near Fort Walton Beach, Florida and weakened to a tropical depression shortly thereafter. The system dissipated over Mississippi later that day.

Around the same time the remnants of Hurricane Bill dissipated over the northern Atlantic,, a new tropical storm developed near the Bahamas on August 26. The system, immediately declared Tropical Storm Danny on its first advisory, erratically moved in a general northwestward direction. Danny attained peak winds of 60 mph (95 km/h) before succumbing to high wind shear. After turning northward, the storm weakened and was eventually absorbed by another low pressure system off the east coast of the United States early on August 29.

September
On September 1, the season's fifth named storm, Tropical Storm Erika, formed east of the Lesser Antilles. Upon forming, the storm had attained its peak intensity with winds of 50 mph (85 km/h). Persistent wind shear prevented the system from intensifying and resulted in the storm's convection being completely displaced from the center of circulation by the time it passed over Guadeloupe on September 2. After entering the Caribbean Sea, Erika briefly regained strength before fully succumbing to strong shear. The system eventually dissipated on September 4 south of Puerto Rico.

Several days after Erika dissipated, a new tropical depression formed southeast of the Cape Verde Islands on September 7. This depression rapidly intensified within an environment of low wind shear and high sea surface temperatures. Receiving the name Fred on September 8, the storm quickly developed an eye feature and was upgraded to a hurricane roughly 24 hours after being named. Within a 12 hour span, the storm's winds increased by 40 mph (65 km/h) to its peak of 120 mph (195 km/h). Upon reaching this intensity, Fred became the strongest storm on record south of 30°N and east of 35°W in the Atlantic basin. Not long after the intensification ceased, it began to weaken as dry air became entrained within the system. By September 11, the storm nearly stalled northeast of the Cape Verde Islands and weakened to a tropical storm. The following day, Fred degenerated into a remnant low before taking a westward track across the Atlantic. The remnants of Fred persisted for nearly a week, nearly regenerating into a tropical depression several times. The low eventually dissipated on September 19 south of Bermuda.

In late September, a new, well-defined tropical wave moved off the west coast of Africa into the Atlantic Ocean. By September 25, the system had developed sufficient deep convection for the NHC to classify it as Tropical Depression Eight. Shortly thereafter, wind shear and decreasing sea surface temperatures caused the depression to weaken. The system degenerated into a remnant low on September 26 before degenerating into a trough of low pressure.

October–November
Originating from an extratropical cyclone east of Newfoundland on September 27, the precursor to Tropical Storm Grace tracked westward towards the Azores, gaining subtropical characteristics. After executing a counterclockwise loop between October 1 and 3, deep convection wrapped around a small circulation center that had developed within the larger cyclone. On October 4, this smaller low developed into a tropical storm while situated near the Azores Islands, becoming the northeastern-most forming Atlantic tropical cyclone on record. The storm quickly turned northeastward and intensified, attaining peak winds of 65 mph (100 km/h) and a minimum pressure of 986 mbar (hPa; 29.11 inHg) before weakening over increasingly colder waters. Early on October 6, Grace transitioned into an extratropical cyclone before dissipating later that day near Wales.

As Grace became extratropical over the northeastern Atlantic, a new tropical depression developed over the central Atlantic, near the Lesser Antilles on October 6. This depression quickly intensified into Tropical Storm Henri as it tracked west-northwestward. Slow development took place over the following day, with Henri attaining its peak intensity midday on October 7 with winds of 50 mph (85 km/h) before wind shear displaced convection from the center of the storm. Early on October 8, the system weakened to a tropical depression and further degenerated into a remnant low later that day. The remnants of Henri persisted for several days before dissipating just off the northern coast of Hispanola on October 11.

The final storm of the 2009 season formed over the southern Caribbean Sea on November 4. The slow moving system quickly developed into Tropical Storm Ida within a favorable environment as it neared the coastline of Nicaragua. Several hours before moving over land, Ida attained hurricane-status, with winds reaching 80 mph (130 km/h). Hours after moving inland, Ida weakened to a tropical storm and further to a tropical depression as it turned northward. On November 7, the depression re-entered the Caribbean Sea and quickly intensified. Early on November 8, the system re-attained hurricane intensity as it rapidly intensified over warm waters.

Ida attained its peak intensity as a Category 2 hurricane early the next day with winds of 105 mph (165 km/h) as it moved over the Yucatan Channel. Not long after reaching this intensity, Ida quickly weakened to a tropical storm as it entered the Gulf of Mexico. Despite strong wind shear, the storm briefly re-attained hurricane status for a third time near the southeastern Louisiana coastline before quickly weakening to a tropical storm. Shortly before moving inland over the southern United States, Ida transitioned into an extratropical cyclone. The remnants of Ida persisted until November 11, at which time the low dissipated. Remnant energy from Ida provided energy for another system which became a powerful nor'easter, causing significant damage in the Mid-Atlantic States. The resulting storm came to be known as Nor'Ida.

Impact
During the 2009 season, nine of the eleven tropical cyclones affected land, of which five actually made landfall. The United States experienced one of its quietest years, with no hurricanes making landfall in the country. Throughout the basin, six people were killed in tropical cyclone-related incidents and total losses reached roughly $77 million. Most of the damage resulted from Hurricane Bill, which caused severe beach erosion throughout the east coast of the United States.

In the United States, tropical cyclones killed six people and caused roughly $50 million in damage. Tropical Depression One brought minor rainfall to portions of the North Carolina coastline in late-May, and left no known damage. Two months later, the first storm to make landfall in the United States, Tropical Storm Claudette, produced moderate rainfall across portions of Florida, Georgia, and Alabama between August 16 and 18. Two people were killed offshore amidst rough seas from the storm. Coastal damage from Claudette reached $100,000.

Roughly a week after Claudette, Hurricane Bill produced significant swells along the eastern seaboard, as well as moderate rainfall in parts of New England as it brushed the region. Two people were killed by the storm's large swells, one in Maine and another in Florida. In New York, severe beach erosion caused by the storm resulted in over $35.5 million in losses. Heavy rain fueled by tropical moisture from Bill produced upwards of 5 in in southern New Hampshire during the span of eight hours, resulting in widespread flash flooding that caused $700,000 in damage.

Several days after Bill, Tropical Storm Danny caused further damage from coastal flooding. One person was killed by high waves in North Carolina produced by the storm. The final storm to affect the United States was Hurricane Ida in early/mid November. Although extratropical by the time it made landfall, the storm produced significant rainfall across parts of the southern states, as well as large swells offshore. One person was killed offshore by the storm and left $4 million in beach losses.

In the Lesser Antilles, Tropical Storms Ana and Erika brought moderate rainfall to several islands but resulted in little damage. In the southern Caribbean, Hurricane Ida caused roughly $2.1 million in damage in Nicaragua after destroying numerous homes and leaving an estimated 40,000 people homeless. Ida also produced significant rainfall across portions of western Cuba, with some areas recording up to 12.5 in of rain during the storm's passage. Elsewhere in the Atlantic, the Azores Islands, Atlantic Canada, Bermuda, Cape Verde Islands and Wales were affected by tropical cyclones or their remnants. In Canada, Hurricane Bill produced widespread moderate rainfall in Nova Scotia and Newfoundland, leaving roughly $10 million in losses. The hurricane also produced tropical storm-force winds in Bermuda. Hurricane Fred briefly impacted the southern Cape Verde Islands as it bypassed the islands early in its existence. The Azores and Wales were also affected by Tropical Storm Grace; however, both areas recorded only minor effects.

Accumulated Cyclone Energy
The table on the right shows the ACE for each storm in the season. ACE is, broadly speaking, a measure of the power of the hurricane multiplied by the length of time it existed, so storms that last a long time as well as particularly strong hurricanes have high ACEs. ACE is only officially released for full advisories on tropical systems at or exceeding 34 knots (39 mph, 63 km/h) or tropical storm strength. Due to the low number of storms in the 2009 season, many of which were short-lived, the overall ACE value was ranked as below-average, totaling under 66. More than half of the season's total ACE was from Hurricane Bill, a long-lived Cape Verde-type hurricane which formed during mid-August. The storm was also responsible for the ACE value for August being 30% above average.

Storm names
The following names were used for named storms in the North Atlantic in 2009. Names that were not used are marked in. This is the same list used in the 2003 season with the exception of Fred, Ida, and Joaquin, which replaced Fabian, Isabel, and Juan respectively. The names Fred and Ida were used for Atlantic storms for the first time in 2009. There were no names retired this year; thus, the same list will be used again in the 2015 season.

Season effects
This is a table of the storms in 2009 and their landfall(s), if any. Deaths in parentheses are additional and indirect (an example of an indirect death would be a traffic accident), but are still storm-related. Damage and deaths include totals while the storm was extratropical or a wave or low.