2004 North Indian Ocean cyclone season
Encyclopedia
The 2004 North Indian Ocean cyclone season had no bounds, but cyclones tend to form between April and December, with peaks in May and November. These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean
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The Arabian sea severe cyclone “Agni” in November formed very close to the equator near latitude 1.5N. Cyclogenesis over the north Indian Ocean at such low latitudes has not occurred in the past. The coexistence of cyclonic disturbances over the Arabian sea and the Bay of Bengal as occurred in June 2004 is also not common. This had however helped the progress of the southwest monsoon across the country during the onset phase.
This was the first North Indian season that featured the naming of storms, though only two storms received names.
Since the storm remained over water throughout its existence, the heaviest rainfall produced by the cyclone fell over water. However, in parts of Gujarat, upwards of 225 mm (8.9 in) of rain fell, triggering flash flooding. At least five people were killed in relation to ARB 01 in India.
, and dissipated later that day. Within hours of making landfall, the IMD reported that the system rapidly intensified, attaining peak winds of 165 km/h (105 mph) and a minimum pressure of 952 mbar as it moved onshore. The storm caused heavy flooding and damage, amounting to 220 casualties.
In the post-analysis by RSMC New Delhi, the system weakened into a depression over Gujarat-Kutch coast in the evening of 3 October without crossing the coast.
. Under an area of moderate vertical shear, it moved west-southwestward and slowly organized. It nearly dissipated on the 24th, but redeveloped on the 26th under an area of favorable upper level winds and good diffluence aloft. On November 27, it became Tropical Depression 5A, and after moving to the west-southwest, became Tropical Storm Agni on the 28th only 50 miles (80.5 km) from the equator
(about 0.7°N). In its developmental stages, its circulation crossed the equator briefly into the southern hemisphere, while retaining its counter-clockwise spin. Under unusually favorable conditions so close to the equator, Agni strengthened and turned to the northwest. The convection concentrated, and quickly became a cyclone on November 29. A pinhole eye briefly developed, but dry air and vertical wind shear weakened Agni back to a tropical storm. The effects were temporary, and Agni re-attained cyclone status on the 30th. On December 1, the shear and dry air returned, and Agni again weakened back to a tropical storm. After moving to the northwest for much of its lifetime, the storm turned to the west towards northeastern Africa
, under the influence of the subtropical ridge
to its north. Late on December 3, the storm weakened to a tropical depression, and made landfall on eastern Somalia
on the 4th. It turned to the south, and dissipated after reaching the Arabian Sea
on December 5.
When Tropical Storm Agni reached a position of 50 miles (80.5 km) north of the equator, it became the nearest a tropical cyclone has ever approached to the equator, less than half of Typhoon Vamei
's previous record distance of 103 miles (165.8 km). However, because Agni formed more to the north and tracked southwestward, Vamei retains the record for the southernmost formation. RSMC New Delhi also admitted that cyclogenesis over the north Indian Ocean at such low latitudes has not occurred in the past. Because the storm was weak and the convection disorganized when it hit Somalia, no damage or deaths were reported from the storm.
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
.
Season summary
In 2004, RSMC New Delhi identified one Very Severe Cyclonic Storm and three Severe Cyclonic Storms. Out of the four cyclonic storms, three developed over the Arabian Sea and only one formed over the Bay of Bengal. Joint Typhoon Warning Center identified one more tropical cyclones(4A) in Arabian sea. The notable features is that the Arabian sea was more active than the Bay of Bengal during 2004.The Arabian sea severe cyclone “Agni” in November formed very close to the equator near latitude 1.5N. Cyclogenesis over the north Indian Ocean at such low latitudes has not occurred in the past. The coexistence of cyclonic disturbances over the Arabian sea and the Bay of Bengal as occurred in June 2004 is also not common. This had however helped the progress of the southwest monsoon across the country during the onset phase.
This was the first North Indian season that featured the naming of storms, though only two storms received names.
Severe Cyclonic Storm ARB 01
On May 5, Tropical Depression 1A developed in the Arabian Sea, 200 miles (321.9 km) west of the Indian coast. It wandered for the next three days, slowly strengthening to its peak of 50 mi/h winds. The tropical storm turned northwestward, where dry air and moderate shear caused the system to dissipate on the 10th.Since the storm remained over water throughout its existence, the heaviest rainfall produced by the cyclone fell over water. However, in parts of Gujarat, upwards of 225 mm (8.9 in) of rain fell, triggering flash flooding. At least five people were killed in relation to ARB 01 in India.
Very Severe Cyclonic Storm BOB 01
A tropical storm formed on May 17 in the Bay of Bengal, 230 nautical miles (426 km) south of Calcutta. It drifted southwestward initially, followed by a turn to the northeast where it intensified to a 70 mi/h tropical storm. Not long after on the 19th, the tropical storm hit MyanmarMyanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
, and dissipated later that day. Within hours of making landfall, the IMD reported that the system rapidly intensified, attaining peak winds of 165 km/h (105 mph) and a minimum pressure of 952 mbar as it moved onshore. The storm caused heavy flooding and damage, amounting to 220 casualties.
Deep Depression BOB 02
A deep depression existed in the Bay of Bengal on June 11, made landfall on the thirteenth and dissipated on June 14.Depression BOB 03
A depression developed over land near the India-Bangladesh border on September 12, remained nearly stationary for the next few days, and dissipated on September 15.Severe Cyclonic Storm Onil
On October 1, a tropical depression developed in the northeastern Arabian Sea. It moved northeastward, where it strengthened into a tropical storm on the 2nd. The name, "Onil" was the first cyclonic system to ever be named in history of the North Indian Ocean cyclones. Onil later reached a peak with sustained winds of 45 mi/h, though other forecasting agencies estimated a stronger storm. Regardless, the storm entrained dry air and rapidly weakened. Though operationally Onil was said to have made landfall on India, the low level circulation halted just before landfall, drifted southward, and dissipated on the 10th.In the post-analysis by RSMC New Delhi, the system weakened into a depression over Gujarat-Kutch coast in the evening of 3 October without crossing the coast.
Depression BOB 04
A depression existed in the Bay of Bengal between October 2 and October 4 before making landfall on the fourth.Depression BOB 05
A depression developed over land near the India-Bangladesh border on October 7, traveled northeast over Bangladesh, and dissipated on October 8.Deep Depression ARB 04
A tropical storm developed in the central Arabian Sea on November 4. It moved generally westward, where it slowly weakened until dissipating on the 7th.Severe Cyclonic Storm Agni
On November 19, an area of convection developed and persisted about 500 miles (804.7 km) east-southeast of ColomboColombo
Colombo is the largest city of Sri Lanka. It is located on the west coast of the island and adjacent to Sri Jayawardenapura Kotte, the capital of Sri Lanka. Colombo is often referred to as the capital of the country, since Sri Jayawardenapura Kotte is a satellite city of Colombo...
. Under an area of moderate vertical shear, it moved west-southwestward and slowly organized. It nearly dissipated on the 24th, but redeveloped on the 26th under an area of favorable upper level winds and good diffluence aloft. On November 27, it became Tropical Depression 5A, and after moving to the west-southwest, became Tropical Storm Agni on the 28th only 50 miles (80.5 km) from the equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
(about 0.7°N). In its developmental stages, its circulation crossed the equator briefly into the southern hemisphere, while retaining its counter-clockwise spin. Under unusually favorable conditions so close to the equator, Agni strengthened and turned to the northwest. The convection concentrated, and quickly became a cyclone on November 29. A pinhole eye briefly developed, but dry air and vertical wind shear weakened Agni back to a tropical storm. The effects were temporary, and Agni re-attained cyclone status on the 30th. On December 1, the shear and dry air returned, and Agni again weakened back to a tropical storm. After moving to the northwest for much of its lifetime, the storm turned to the west towards northeastern Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, under the influence of the subtropical ridge
Subtropical ridge
The subtropical ridge is a significant belt of high pressure situated around the latitudes of 30°N in the Northern Hemisphere and 30°S in the Southern Hemisphere. It is characterized by mostly calm winds, which acts to reduce air quality under its axis by causing fog overnight, and haze during...
to its north. Late on December 3, the storm weakened to a tropical depression, and made landfall on eastern Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
on the 4th. It turned to the south, and dissipated after reaching the Arabian Sea
Arabian Sea
The Arabian Sea is a region of the Indian Ocean bounded on the east by India, on the north by Pakistan and Iran, on the west by the Arabian Peninsula, on the south, approximately, by a line between Cape Guardafui in northeastern Somalia and Kanyakumari in India...
on December 5.
When Tropical Storm Agni reached a position of 50 miles (80.5 km) north of the equator, it became the nearest a tropical cyclone has ever approached to the equator, less than half of Typhoon Vamei
Tropical Storm Vamei
Tropical Storm Vamei was a Pacific tropical cyclone that formed closer to the equator than any other tropical cyclone worldwide...
's previous record distance of 103 miles (165.8 km). However, because Agni formed more to the north and tracked southwestward, Vamei retains the record for the southernmost formation. RSMC New Delhi also admitted that cyclogenesis over the north Indian Ocean at such low latitudes has not occurred in the past. Because the storm was weak and the convection disorganized when it hit Somalia, no damage or deaths were reported from the storm.
See also
- List of North Indian Ocean cyclone seasons
- List of wettest known tropical cyclones in Pakistan
- 2004 Atlantic hurricane season2004 Atlantic hurricane seasonThe 2004 Atlantic hurricane season officially began on June 1, 2004, and lasted until November 30, 2004. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin...
- 2004 Pacific hurricane season2004 Pacific hurricane seasonThe 2004 Pacific hurricane season officially started on May 15, 2004 in the eastern Pacific, and on June 1, 2004 in the central Pacific, and lasted until November 30, 2004...
- 2004 Pacific typhoon season2004 Pacific typhoon seasonThe 2004 Pacific typhoon season has no official bounds; it ran year-round in 2004, but most tropical cyclones tend to form in the northwestern Pacific Ocean between May and November...
- South-West Indian Ocean cyclone seasons: 2003-042003-04 South-West Indian Ocean cyclone seasonThe 2003-04 South-West Indian Ocean cyclone season was an annual event of tropical cyclone formation. It started on November 15, 2003 and ended on April 30, 2004. For Mauritius and the Seychelles, the season continued until May 15. These dates conventionally delimit the period of each year when...
, 2004-052004-05 South-West Indian Ocean cyclone seasonThe 2004-05 South-West Indian Ocean cyclone season was an annual event of tropical cyclone formation. It started on November 15, 2004 and ended on April 30, 2005. For Mauritius and the Seychelles, the season continued until May 15. These dates conventionally delimit the period of each year when... - Australian region cyclone seasons: 2003-042003-04 Australian region cyclone seasonThe 2003–04 Australian region cyclone season was an event in the ongoing cycle of tropical cyclone formation. It began on 1 November 2003 and ended on 30 April 2004...
, 2004-052004-05 Australian region cyclone seasonThe 2004–05 Australian region cyclone season was an event in the ongoing cycle of tropical cyclone formation. It began on 1 November 2004 and ended on 30 April 2005... - South Pacific cyclone seasons: 2003-042003-04 South Pacific cyclone seasonEarly on December 4, RSMC Nadi reported that Tropical Disturbance 01F had formed 725 km to the north-west of Nadi in Fiji. The disturbance was located within a large area of convection and lied to the north of an anticyclonic circulation. During that day the disturbance gradually organised and...
, 2004-052004-05 South Pacific cyclone seasonLate on October 28, RSMC Nadi reported that a tropical depression had formed about 420 km, to the northeast of Honiara in the Solomon Islands. The depressions low level circulation center at this time was located under the deep convection and lied in a weak monsoonal trough which had a low to...
External links
- Gary Padgett Tropical Cyclone Summary
- Gary Padgett Tropical Cyclone Summary Part 2
- Tropical Cyclone Operational Plan for the Bay of Bengal and the Arabian Sea
- Impact of Cyclonic Storms and Suggested Mitigation Actions (by India Meteorological Department)
- WMO/ESCAP Panel on Tropical Cyclones Final Report