Status and Plans for Operational Tropical Cyclone Forecasting and Warning Systems in the North Indian Ocean Region - Monitoring and Prediction of Tropical Cyclones in the Indian Ocean and Climate Change - page 160

is HH+03 hrs. These bulletins contain present location of cyclone in lat./long.,
maximum sustained surface wind (in knots), direction of past movement and
estimated central pressure, forecast position in lat./long. and forecast winds in
knots valid at HH+6, HH+12, HH+18 and HH+24 hrs in coded form. The
tropical cyclone advisories are transmitted on real time basis through GTS and
AFTN channels to designated international airports of the region prescribed
by ICAO.
6.4 Bulletin for India Coast
These bulletins are issued from the stage of depression onwards during the
stage of depression/deep depression; it is issued based on 00, 03, 06, 12 and 18
UTC observations. When the system intensifies into a cyclonic storm over
NIO and likely to affect India, these bulletins are issued at 00, 03, 06, 09, 12,
15, 18 and 21 UTC (every three hourly interval) based on previous observations.
This bulletin contains present status of the system i.e. location, intensity; past
movement and forecast intensity and movement for next 72 hours or till the
system weaken into a low pressure area, likely landfall point and time and
likely adverse weather including heavy rain, gale wind and storm surge.
Expected damage and action suggested are also included in the bulletins. This
bulletin is completely meant for national users and these are disseminated
through various modes of communication including All India Radio, Telephone/
Fax, print and electronic media. It is also posted on cyclone page of IMD
website.
6.5 Wind Forecast for Different Quadrants
The forecast of surface wind in four quadrants of a cyclone commenced with
effect from cyclone, Giri during October 2010. In this forecast, the radius of
34, 50 and 64 knot winds are given for various forecast periods like +06, +12,
+18, +24, +36, +48, +60 and +72 hrs. A typical graphical presentation of this
forecast is shown in Fig. 7. This quadrant wind forecast was issued as bulletin
from the deep depression stage onwards to various users through global
telecommunication system. It was also given to NWP centres like IIT, Delhi
and NCMRWF for their use in creating the synthetic vortex.
6.6 User Specific Bulletins
The ACWCs/CWCs issue warnings to ships in the high seas, ships in coastal
waters, ports, fishermen, government officials and the general public regarding
adverse weather likely to be experienced in their respective areas. The bulletins
and warnings issued by ACWCs/CWCs for their respective areas of
responsibility include (i) Sea area bulletins for ships plying in High Seas, (ii)
Coastal weather bulletins for ships plying in coastal waters, (iii) Bulletins for
Global Marine Distress and Safety System (GMDSS). Broadcast through Indian