eastern region oil spill disaster contingency plan - Indian Coast Guard

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(b) The frequency of formation of Depressions, Cyclonic Storms and
Severe Cyclonic storm per year are 0.4, .036 and 0.80 respectively. The
tracks of storms in the month of November are very regular and any part
of the Bay of Bengal may be affected. In majority of the cases
Depressions/ Cyclonic storms initially move in WNWly direction, strike
Tamil Nadu South Andhra Coast, Pass across the land and emerge into the
Arabian Sea and re-intensify. During period from 1892 to 1991, 70% of
the Depressions and Cyclonic Storms crossed the East Coast of India
between 10 degrees and 16 degree North. The Storms which form in more
northerly latitudes move in NWly direction graze along the coast and later
recurve north - eastwards.
(c) Life Span: The average life span of the Depression / Cyclonic Storm in
the Bay of Bengal is 4 to 6 days during this month.
(d) Rainfall: Wide spread heavy rain generally occurs close and to the
North of the track of the system. As a general rule, area of heavy rainfall
extends up to 4 to 6 degree to the North form the center of a storm while
in the South it may extend up to only 1 degree. Heavy rainfall also extends
3 to 4 degree to the East and 1 degree to the west.
(e) Storm Surges: In addition to the very strong winds reaching up
to hurricane intensity, storm surges are observed whenever a Cyclonic
/Serve Cyclonic Storm crosses or grazes the coast:. The devastating
effects associated with storm surges depend on many factors such as the
configuration of the coast the topography of the sea bottom, phase of the
Moon etc. the coastal of South Andhra Pradesh North Tamil Nadu and
North Orissa and West Bengal are more prone to high storm surges.
58. Easterly Waves: Waves are observed frequently in the lower troposphere
Easterly wind flow over Bay of Bengal. These are known as Easterly Waves and
they generally form over the west Central and South bay. These waves generally
move in westerly direction and give weather over Tamil Nadu and Andhra
Pradesh coast.
59. Currents in the Bay of Bengal. During the month of November a weak
gyre is seen in south west bay off Tamil Nadu and Sri Lanka coast. The coastal
currents become predominantly strong. Particularly, off Tamil Nadu and Sri
Lanka coast with average rate of currents being more than 01 kts. The currents