(Redirected from 2006 Atlantic Hurricane Season)
The '2006 Atlantic hurricane season' was an event in the annual cycle of
tropical cyclone formation. The season was unusual in that no hurricanes made landfall in the United States of America, the first such occurrence since
2001.
[1] It started on
June 1,
2006, and officially ended on
November 30,
2006. These dates conventionally delimit the period of each year when most tropical cyclones form in the
Atlantic basin.
One system,
Tropical Storm Zeta from the
2005 season, continued through early January, only the second time on record that had happened. Tropical Storm Alberto was responsible for 2 indirect deaths when it made
landfall in
Florida.
Hurricane Ernesto caused heavy rainfall in
Haiti, and directly killed at least 7 people in Haiti and the
United States. Four more hurricanes formed after Ernesto, including the strongest storms of the season, Hurricanes
Helene and
Gordon. However, no tropical cyclones formed in the month of October, the first time this had happened since the
1994 season.
[2]
Following the intense activity of the 2005 season, forecasts predicted the 2006 season would be very active, though not as active as 2005. However, in 2006, a rapidly-forming
El Niño event, combined with the pervasive presence of the
Saharan Air Layer over the tropical Atlantic and a steady presence of a robust secondary high related to the
Azores high centered around Bermuda, contributed to a slow season and all tropical cyclone activity ceasing after
October 2.
[3]
Seasonal forecasts
Forecasts of hurricane activity are issued before each hurricane season by noted hurricane experts
Philip J. Klotzbach, Dr.
William M. Gray, and their associates at
Colorado State University; and separately by
NOAA forecasters.
Klotzbach's team (formerly led by Dr. Gray) defined the average number of storms per season (1950 to 2000) as 9.6 tropical storms, 5.9 hurricanes, and 2.3 major hurricanes (storms exceeding Category 3 strength in the
Saffir-Simpson Hurricane Scale). A normal season, as defined by NOAA, has 6 to 14 named storms, with 4 to 8 of those reaching hurricane strength, and 1 to 3 major hurricanes.
[4][5]
Pre-season forecasts
On
December 5,
2005, Klotzbach's team issued its first extended-range forecast for the 2006 season, predicting a well above-average season (17 named storms, 9 hurricanes, 5 of Category 3 or higher).
Similar to the
2005 season, the team predicted a high potential for at least one major hurricane to directly impact the
United States: the forecast indicated an 81% chance of at least one major hurricane striking the U.S. mainland, which included a 64% chance of at least one major hurricane strike on the
East Coast of the United States including the
Florida peninsula, and a 47% chance of at least one major hurricane strike on the
Gulf Coast of the United States from the
Florida Panhandle westward. In addition, the potential for major hurricane activity in the
Caribbean was above average. A few months later, on
April 4,
2006, CSU issued another forecast which reaffirmed the forecast previously made in December.
[7]
On
May 22,
2006,
NOAA released their pre-season forecast for the 2006 season. They predicted 13 to 16 named storms, with 8 to 10 becoming hurricanes, and 4 to 6 becoming major hurricanes.
[8]
On
May 31,
2006, Klotzbach's team released their final pre-season forecast for 2006, reconfirming their previous numbers.
[9]
Midseason outlooks
On
August 3,
2006, Klotzbach's team lowered their season estimate to 15 named storms, with 7 becoming hurricanes and 3 becoming major hurricanes. They noted that conditions had become less favorable for storms than they were earlier in the year. The sea level pressure and trade wind strength in the tropical Atlantic were reported to be above normal, while sea surface temperature anomalies were on a decreasing trend.
[10]
On
August 8,
2006, the
NOAA revised their season estimate to 12–15 named storms, with 7–9 becoming hurricanes and 3–4 becoming major hurricanes. They attributed the reduction to less favorable environmental conditions, a decrease in
La Niña conditions, and the lack of a "very persistent upper-level ridge pattern over the eastern
U.S. and western
Atlantic."
[11]
On
September 1, Klotzbach's team lowered their season estimate to 13 named storms, 5 hurricanes and 2 major hurricanes, citing larger amounts of the
Saharan Air Layer as well as an
El Niño trend in the Pacific.
[12] They again reduced the number of tropical storms expected for the season a month later on
October 3, when they released a new forecast of 11 named storms, 6 hurricanes and 2 major hurricanes, citing the ongoing
El Niño.
[13]
Storms
Tropical Storm Zeta (2005)
Tropical Storm Zeta formed on
December 30,
2005 and lasted until
January 6,
2006. Although it spent most of its existence in 2006, it is officially a storm of the
2005 Atlantic hurricane season since it formed during 2005. Zeta joined
Hurricane Alice as only the second
Atlantic tropical cyclone in recorded history to exist during two different calendar years.
Tropical Storm Alberto
On
June 10, an area of disturbed weather associated with a broad low pressure area off the coast of
Belize organized over the warm waters of the
Caribbean Sea and became the first tropical depression of the season. Southwesterly vertical wind shear was a constant companion to this system, but as it moved closer to
Florida, the depression strengthened into a tropical storm on the morning of
June 11. Passing over the warm deep water of the
Loop Current allowed accelerated development, and the cyclone's maximum sustained winds increased to its peak strength of 70 mph (115 km/h), just shy of hurricane strength. Subsequent weakening occurred as it moved over the cooler waters of the
continental shelf.
[14]
Alberto made landfall midday on
June 13, about 50 miles (85 km) southeast of
Tallahassee, Florida, with windspeeds of approximately 45 mph.
[15] Alberto brought a
storm surge of five feet to the
Big Bend area of the Florida coastline, flooding areas of
Cedar Key and
Crystal River. The large system was slow to weaken, moving across
Georgia and
the Carolinas before being downgraded to a tropical depression early on
June 14. Alberto became an
extratropical storm that morning while quickly moving towards the coast. As an extratropical storm, Alberto strengthened rapidly offshore New England and the Canadian Maritimes, becoming an oceanic storm by the afternoon of
June 15.
[16][17] Damage in the
United States totaled to $565,000 (2006 USD).
★ The
National Hurricane Center (NHC)'s
archive on Tropical Storm Alberto.
★ The
Hydrometeorological Prediction Center (HPC)'s
archive on Tropical Storm Alberto.
Unnamed Tropical Storm
In the post-season analysis, an additional tropical storm was identified to have formed out of an extratropical low produced by the same frontal boundary that spawned Tropical Storm Beryl in the
Gulf Stream on
July 17, south of
Nantucket Island. It was briefly a tropical storm before becoming a remnant low on
July 18 southeast of
Nova Scotia. It crossed over
Atlantic Canada with rain and wind, but no damage or fatalities were reported. Had it been discovered operationally, it would have been named Tropical Storm Beryl.
[18] It dissipated northeast of
Cape Race,
Newfoundland.
Tropical Storm Beryl
In mid-July, a front moved off the east coast of the United States and stalled, spawning a series of low pressure areas. Because steering currents were weak, the most southerly disturbance slowly drifted to the south, and gradually became more organized a few hundred miles east of the
North Carolina coast. On the morning of
July 18, the low pressure area was designated the second tropical cyclone of the season. That afternoon, the depression was upgraded to Tropical Storm Beryl.
[19]
Beryl continued moving to the north until it turned to the northeast on
July 20. Beryl paralleled the
East Coast of the United States and made landfall on
Nantucket island before becoming extratropical southwest of
Nova Scotia on
July 21.
★ The
NHC's
archive on Tropical Storm Beryl.
Tropical Storm Chris
On about
July 26, a vigorous tropical wave formed off the coast of
Africa and slowly tracked westward. It slowly developed due to poor environmental conditions and it became a tropical depression late on
July 31 about 160 miles (260 km) east of
Antigua.
[20] The depression soon strengthened further and was named Tropical Storm Chris six hours later.
[21] National Hurricane Center forecasters dismissed some
computer models, which dissipated Chris quickly, as they did not have a handle on the strength of the storm.
[22] Tropical Storm Chris moved to the northwest and gradually strengthened before reaching its peak strength on
August 2 with winds of 65 mph (100 km/h), when it was to the northeast of the
United States Virgin Islands.
[23] The storm was forecast to strengthen further and become a hurricane as it moved into the
Bahamas. However, Chris began to be affected by wind shear and became disorganized. The storm weakened to a tropical depression on
August 4, and dissipated as it approached the
Cuban coast.
In response to the storm's projected path into the
Gulf of Mexico, prices for crude oil rose on the
New York Mercantile Exchange at branch offices in
London.
[24] Natural gas prices rose considerably in New York Mercantile Exchange electronic trading on
August 2. Anticipation of a threat to supply by a potential Hurricane Chris coupled with high demand during an ongoing
heat wave are cited as reasons for the price move.
[25] On
August 2 approximately 600 tourists evacuated the
Puerto Rican islands of
Vieques and
Culebra as tropical storm warnings had been issued.
[26] Cruise lines such as
Royal Caribbean re-routed their ships to avoid the storm.
[27] In
Puerto Rico, rainfall from the storm caused the
Fajardo River to overflow its banks. The overflown waters temporarily closed a highway in the northeastern portion of the island.
[28] Rainfall reached up to 2
inches (50
mm) across portions of
Hispaniola, the
Turks and Caicos, the
Bahamas, and eastern
Cuba, and reached 4 inches (100 mm) in some mountainous areas.
[29]
★ The NHC's
archive on Tropical Storm Chris
Tropical Storm Debby
A system off the coast of
Africa, which the
NHC had monitored for several days, was upgraded to
tropical depression status on
August 21 and designated as Tropical Depression Four. A
tropical storm warning was immediately issued for the
Cape Verde islands as the system threatened to pass over or near the southern part of the
archipelago. However, the system failed to strengthen into a tropical storm before passing the chain of islands, and the warning was discontinued the following morning.
The depression was upgraded to a tropical storm and named Debby late on
August 22. While it had been expected to strengthen into a hurricane, this never occurred, and Debby weakened into a tropical depression on
August 26. It continued to the north and lost tropical characteristics on
August 27.
★ The
NHC's
archive on Tropical Storm Debby.
Hurricane Ernesto
At 3:15 p.m. EDT (1915 UTC) on
August 24, a reconnaissance flight determined that a tropical wave passing through the
Windward Islands had developed a closed tropical circulation, and advisories were commenced on Tropical Depression Five. By 5 p.m. EDT (2100 UTC) on
August 25, a second flight had found sustained tropical-storm force winds, and the system was named Ernesto. Ernesto became a hurricane on the morning of
August 27 just south of
Haiti, before it was downgraded back to a tropical storm in the afternoon. The storm caused 2 deaths in Haiti due to rainfall.
Ernesto made landfall near
Guantanamo Bay,
Cuba, early in the morning on
August 28. At one point the storm was predicted to become a major hurricane in the
Gulf of Mexico and threaten parts of the
Gulf Coast, a grim possibility in light of the one-year anniversary of
Hurricane Katrina's landfall.
[30] However, Ernesto moved much farther east than anticipated, and made landfall as a tropical storm on the southern tip of
Florida on
August 29. Two people died in Florida in road traffic accidents attributed to the weather conditions, as the cyclone slowly moved northward across the southern half of the peninsula. Ernesto regained tropical storm strength as it crossed Florida and emerged from land near
Cape Canaveral, and was just below hurricane strength when it made landfall again in
North Carolina on
August 31.
Damage in Virginia totaled to $104 million (2006
USD),
[31] and in total the storm caused about $500 million (2006 USD) in damage.
[32]
The storm, while extratropical, moved over Southern
Ontario and dissipated over the St. Lawrence river area in
Quebec.
★ The NHC's
archive on Hurricane Ernesto.
★ The HPC's
archive on Tropical Depression Ernesto.
Hurricane Florence
Tropical Depression Six formed from an area of low pressure midway between
Africa and the
Lesser Antilles on
September 3. Initial strengthening of the depression was slow due to shearing wind conditions. Despite the moderate to high
wind shear, it strengthened enough to become Tropical Storm Florence on the morning of
September 5. After becoming a tropical storm, Florence's wind field began to expand greatly; at one point tropical storm-force winds extended outward up to 405 miles from the center. With a disorganized structure and multiple circulation centers, Florence remained a weak tropical storm for several days, even after external conditions became favorable for strengthening. Around the evening of
September 8 it resolved to a single center and steady strengthening resumed - "science had prevailed", as one forecaster remarked.
[33] On the morning of
September 10, Florence reached hurricane strength.
Large
swells,
rip tide, and
undertow were reported on Bermuda, the
Leeward Islands, the
Virgin Islands, and
Hispaniola.
[34] Florence soon reached its peak as a Category 1 hurricane very near
Bermuda, and became extratropical on
September 12, while still a hurricane.
★ The NHC's
archive on Hurricane Florence.
★ The
CHC's
archive on Hurricane Florence
Hurricane Gordon
As Florence moved away, a low-pressure system gradually became more organized northeast of the
Lesser Antilles. On the evening of
September 10, it developed a closed circulation and was declared Tropical Depression Seven. It continued to intensify, and strengthened into Tropical Storm Gordon on
September 11 and Hurricane Gordon late on
September 12. Gordon attained Category 2 status on the evening of
September 13, and was further upgraded to Category 3 status that same night, making it the first major hurricane of the season.
Around
September 16 it was nearly stationary for some time in the mid-Atlantic about 1000 miles east of
Bermuda, and weakened to be barely a hurricane. However, as it subsequently accelerated eastwards, it restrengthened to category 2. On
September 19 hurricane warnings were issued for the
Azores, as the predicted path passed through the center of that
archipelago. It became extratropical on
September 20 after passing through Azorean waters, but the remnants side-swiped north-western
Spain and then moved rapidly north towards
Ireland and the west of
Britain on
September 21. By the morning of
September 22, it had become absorbed into a large Atlantic low to the west of Ireland.
★ The NHC's
archive on Hurricane Gordon.
Hurricane Helene
On
September 11, a
tropical wave moved off the coast of
Africa. It quickly organized, and on
September 12 was declared Tropical Depression Eight. Continuing to organize, it reached tropical storm strength on
September 13, becoming a hurricane on
September 16 and a major hurricane on
September 17. It moved generally west-northwestward before commencing a northeasterly turn. Large currents from Helene lashed
Bermuda. It became fully extratropical on
September 24. The extratropical storm dissipated over Ireland.
★ The NHC's
archive on Hurricane Helene.
Hurricane Isaac
An area of low pressure in the mid-Atlantic generated active thunderstorms for several days and eventually organized into Tropical Depression Nine on
September 27 and a tropical storm by
September 28. By that time it was about 810 miles east-southeast of
Bermuda. It became a hurricane on
September 30, and passed about 280 miles (450 km) east of Bermuda before swinging northwards towards
Newfoundland. As it was still a strong tropical storm near the
Avalon Peninsula, tropical storm warnings were issued on
October 2 due to the potential for high winds. Isaac passed 45 km (30 miles) to the southeast of
Cape Race late that afternoon. The
Canadian Hurricane Centre reports that if Isaac had tracked just 50 to 100 km (30 to 60 miles) farther north than it did, the
St. John's area would have experienced much higher winds than the peak gust of 54 km/h (34 mph) it received.
[36]
At its closest approach to the Avalon Peninsula, Isaac was still tropical, and had maximum sustained winds of 50 knots and a minimum central pressure of 993
mbar.
Strongest winds on land in Newfoundland were reported at Cape Race, where a maximum gust to 96 km/h (60 mph) with a sustained wind of 74 km/h (46 mph) was recorded. At
Cape Pine, a peak wind was reported at 76 km/h (47 mph).
However, due to Isaac's small size and fast forward speed, winds were lighter over most of the Avalon Peninsula.
Rainfall from Isaac was not reported to be higher than 25 mm (0.98 inches) in most areas due to Isaac's speed and decreasing amount of moisture. The highest measured amount was 26 mm (1.02 inch) at Cape Race, while Cape Pine reported 19 mm (0.75 inches) and
St. John's reported less than 10 mm (0.39 inches).
★ The NHC's
archive on Hurricane Isaac.
Accumulated Cyclone Energy (ACE) rating
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 calculated for full advisories on tropical systems at or exceeding 35 knots (39 mph/63 km/h) or tropical storm strength.
The cumulative ACE for this season was toward the lower end of the official "Near Normal" grading. The number of tropical storms and hurricanes was near the long-term average.
Storm names
The names to the right were used for named storms that form in the North Atlantic in 2006. No names were retired, so this list will be used again in the 2012 season. This is the same list used in the
2000 season except for Kirk, which replaced
Keith. No storm was given a previously unused name, the first time this had happened since the
1993 season.
The
World Meteorological Organization determined in their annual meeting in the spring of 2006 to again use names from the
Greek alphabet, starting with Alpha, should the main list have run out.
[37] In addition, the organization determined that storm names with Greek letters would not be retired. In case a storm reached the magnitude that might otherwise have lead to retirement, the storm would be listed with the retired names with a footnote indicating the Greek letter would still be available for future storms.
[38]
Retirement
The
World Meteorological Organization retired no names used in the 2006 season. It was first time since the
1997 season that no Atlantic names were retired.
See also
★
List of notable Atlantic hurricanes
★
List of Atlantic hurricane seasons
★
List of tropical cyclone names
★
2006 Pacific hurricane season
★
2006 Pacific typhoon season
★
2006 North Indian cyclone season
★
2005-06 Southern Hemisphere tropical cyclone season
★
2006-07 Southern Hemisphere tropical cyclone season
References
1. Atlantic hurricane best track NHC Hurricane Research Division
2. Monthly Tropical Weather Summary for October 2006 National Hurricane Center
3. Summary of 2006 Atlantic Tropical Cyclone Activity and Verification of Authors' Seasonal and Monthly Forecasts Philip J. Klotzbach and William M. Gray
4.
5.
6. NOAA Reviews Record-Setting 2005 Atlantic Hurricane Season NOAA
7.
8.
9.
10.
11.
12.
13.
14. Tropical Storm Alberto Forecast Discussion #11, 5 p.m. EDT
15. Tropical Storm Alberto Update, 12:45 p.m. EDT, June 13 2006 National Hurricane Center
16. Tropical Storm Alberto Final Public Advisory #18, 11 a.m. EDT, June 14 2006 National Hurricane Center
17. Tropical Storm Alberto Coastal Watches/Warnings and 5-Day Cone, 11 a.m. EDT, June 14 2006 National Hurricane Center
18. http://www.nhc.noaa.gov/pdf/TCR-AL502006_Unnamed.pdf
19. Tropical Storm Beryl Tropical Cyclone Update, 4:55 p.m. EDT, July 18 2006 National Hurricane Center
20. Discussion for Tropical Depression Three, 11:00 p.m. EDT, July 31 2006 National Hurricane Center
21. Discussion for Tropical Depression Three, 5:00 a.m. EDT, August 1 2006 National Hurricane Center
22. Discussion for Tropical Depression Three, 11:00 a.m. EDT, August 1 2006 National Hurricane Center
23. Discussion for Tropical Storm Chris, 11:00 a.m. EDT, August 2 2005 National Hurricane Center
24. Oil surges as Storm Chris heads toward Gulf of Mexico
25. Natural Gas Surges in New York on Hurricane Threat, Heat Wave
26. Storm prompts tourists' evacuation
27. Tropical Weather Update for August 2 2006 Royal Caribbean
28. Tropical Storm Chris weakens further
29. http://www.zeenews.com/znnew/articles.asp?aid=313893&ssid=26&sid=ENV
30. http://news.yahoo.com/s/nm/20060826/us_nm/weather_hurricanes_louisiana_dc_1
31. ''WAVY'' Kaine seeks disaster declaration for 25 localities URL Accessed: September 11, 2006
32. ftp://ftp.met.fsu.edu/pub/weather/tropical/Monthly/2006120114.ABNT30
33. Discussion for Tropical Storm Florence, 11:00 a.m. EDT, Sept. 8, 2006 National Hurricane Center
34. Bermuda braces as Florence becomes hurricane
35. Tropical Cyclone Report: Hurricane Helene Brown, Daniel P.
36. http://www.atl.ec.gc.ca/weather/hurricane/bulletins/20061003022851.Isaac.txt.en
37. Tropical Weather Outlook National Hurricane Center
38. RA IV Hurricane Committee Twenty-eighth Session report Tropical Cyclone Programme
External links
★
National Hurricane Center (NHC)
★
★
NHC's Atlantic Tropical Weather Outlook - updated four times daily
★
★
NHC's 2006 Advisory Archive
★
HPC's Rainfall Page for tropical cyclones which affected the United States in 2006
★
Unisys' 2006 Season Page – includes map of paths of all storms
★
Flash Hurricane Tracker - track active and archived hurricanes.
★
NRL hurricane page -
Naval Research Laboratory page with extensive archives on individual storms
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