Tropical Cyclone Programme
Cyclone Programme RA IV Hurricane Committee
At the kind invitation
of the Government of Bolivarian Republic of Venezuela, the twenty-third
session of the RA IV Hurricane Committee was held in Maracay from 23 to
27 March 2001. There were 36 participants at the session from 23 Members
of the Association and six of regional and international organizations.
Highlights of the
outcome of the session:
operational aspects of the hurricane warning system and related matters
and headings of subtropical depressions
The Committee discussed the submission by France concerning difficulties
being experienced with the numbering system and the heading for subtropical
depressions (WWNT) when compared to that for tropical depressions (WTNT),
as indicated in the Hurricane Operational Plan. The Chairman pointed out
that there was an error in the Plan and that the heading had been changed
some time ago. WTNT is the heading now used for both subtropical and tropical
depressions. The Chairman alluded to the difficulties in determining the
true tropical or extratropical characteristics of many systems which might
end up being classified as subtropical. However, the Committee decided
that one numbering system should be used for both systems.
over land areas
The Committee recalled its discussions at the previous session about the
making of hurricane reconnaissance flights over land. The RSMC pointed
out that pilots would not take the responsibility of releasing dropwindsondes
over land because of the possibility of injury on the ground, and therefore
emphasized the importance of the upper-air soundings from the land stations,
including the making of special soundings.
Attachment of hurricane
forecasters to RSMC Miami
The Chairman expressed his pleasure with the programme of assigning bilingual
(English/Spanish) forecasters from NMHSs in the Region to the RSMC. He
felt that the assignments had helped both the RSMC and the individual
NMHS and urged others to make their bilingual forecasters available during
hurricane season whenever possible.
Post tropical cyclone
The Committee discussed the use in connection with tropical cyclones,
of the guide to report on heavy rainfall events, which had been devised
by the RA IV Working Group on Hydrology. The guide had been presented
to the Committee in its full detail at its last session. The Committee
decided that the Chairman and the two Vice-Chairmen would work on producing
a format based on the guide for post tropical cyclone report for inclusion
in the Operational Plan. The modified version would be prepared as a document
for consideration and adoption by the twenty-fourth session of the Committee
in 2002. NMHSs were urged to consult with the hydrological community in
their countries when compiling the rainfall information.
The Committee made
amendments and changes to the RA IV Hurricane Operational Plan. It recommended
to XIII-RA IV the approval of the amendments to the text of the Plan.
The Committee urged WMO to publish a new 2001 edition in English and Spanish,
as soon as possible.
A detailed review
of all components of the Technical Plan and its Implementation Programme
was carried out, taking into account the development and progress made
by Members since the twenty-second session of the Committee. The Committee
recommended to XIII-RA IV the approval of the updated RA IV Hurricane
Committees Technical Plan and its Implementation Programme.
The USA offered to
host the twenty-fourth session of the RA IV Hurricane Committee in Orlando,
Florida from Wednesday, 3 April to Wednesday, 10 April 2002, in conjunction
and concurrently with the US National Hurricane Conference, which is to
be held from 1 to 5 April 2002.
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