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Forecasting and Warning Systems
fOr Cyc rues —	—	Indian
OvDartmenr
7?oQical cyclones Me a natlonl pl)enomenon, ovn tht globe WF)ICtI C~hhOt 2* prwented but Its ltnQactS Could be minim sea by underStaPWIflg 1(3 reQuist Deftaviovv~ timely prediction and )UstOt7Ca~?y bned damage assessment The
impacts of tropicai tyc~Qnes ars not dependent on strengrh and frequency v( occurance, but are rz-iore specific to
location and time øf occtnnee Ath’ai-rced tecflraogies like remote sensing, compurers nave maoe ~t possible to predict t)~e size, inrens~ty and nEh OF nie cyclones, It is me governments of We ntlons to ~votve efFective, 517o?tanct tono term median/sins to utWse tnese oreaictfons 31d forecasts forminlmtslng toss of life and omperty over tfie oenod of time. India is one of me most- nii squØpetlcounrles in the world in termsofsnpJustlcated recnnorogy ana satellite in placa M that 15 requlrecfls to mobI~se arcs era Ht its tackforce for read (ness and qWckre~onseto Cite forecasting, and communication sysrem
tflfls Wà~4 Sflems ii baa
The Indian Metsoroiouical Deoartxnent (1MW ~as a well establisried otflriFzational set UI) for observing.
detecting, tracking an~ forecastir-ig cyclones and issuing
cyclone warn~n~ wrienevera cycLone develops in the ~ay
Of Bengal v~C (lie Arabian sea. Cycions warnings are
prov(dec througn six cyclone warning centes ~ocated at caKutta. Ehubanesliwar, Visakapatnam. ChennaL Mum baF and Aflrnedabari These centres have dlstPrtct resgons~bIIIties areawlse, covenrig both the east and west
Coasts OF rr-iclla ana thE oceanic areas of the Day of flengai
and tne Anflian Sea, Including Anoaman and Nicocar
IsLands aad takshwacieet.
The cyclone warn in9 btiiietlns are Issued to AR India Radlo
and Doordarshan for broadcast/telecast In cflUerent
languages. on an all India basIs such wriings are Issued
to Al! India radio and Dootdarshan, New Oe%flt f-rum the cyclone Warning Division at HO offIce~ New DelhI. 1MO, througri its 110 office at New Delhi Øi-ovlde cycrone information t~ the controi nioen and Crisis Management Group set up In the Ministry Of Agrlcultwe. Government OF ir)clja, Which Is FJnahy resDol-isible to c ordinate actions
of variot,s other central Covemrnent Agencies lot taking effective disaster mutigation measures. Cyclone Wafn~ PD.rislon at New DethI also caters to the need oi Enternatlonal reauiremeriIs such as issue of Tropical weather Outlook and Cyclone Athflso?leS to its
neighbouring countr]eL con slderJng the cycion.		_____
warning capabilities of India Meteoroio~lcal
*eflrtment. New Delhi has been d,sigllated as
R.Sonal S~ecIaiIr~ct M o#oia~ltal C*~t* CR~CI by
WMO which IS one antong the four such centen In the
world trusted with the cyclone wanltbØ services for	—-
their area of responsibility.
Sotdce. L4MO - No Jfl M Decade aga~nff Natwal DIsatsrsJ
Cydone Tracking Wnre~er there i~ a Cyclone in tile sea areas a4~atenv to rndi& Itis tracked with the help of INsATsateHite, pc~weflu1 cyclone cletectJon radars with a range OF 4(X) km intta lied at 11 Calcutta, liii ParacIlD, illilVIsaKapatnarrt fiw Macililinatanam. Il/I Cha1n~~~ lvi) itaraikal ~, nie east coast and (viii Goa. (viii) Cocflin, (i~ Mijmbai and (XI BfHJJ aiang tfte west coast arid other conventlonai
meteoroIoq~cai otservat~ons irtciu’rllng shic’s report The cyclone detection radar network in India is shown in the
_____________________________________________ figure. FacIlity i~so ex’sU to morrttor cloud patterns from Polar OrbitIng meteorologIcaL sateilitet The present
cyclone Detection Radars
in addition to above, cyclone warnings are disseminated
through teleprinters, telex, facsimile and telephones
cyclone surveillance system in the country is such that no cyclone in the region can escape detection at any time in its life cycle. Three High Windspeed Recorders (HWSR) have been installed along the East Coast to record the wind upto 200 kts. Installation of more such recorders is in progress.
User Agencies
IMD provides warnings against tropical cyclones to the coastal regions of the country and for the high seas as per assigned area of responsibility. The main user organizations served by the department are commercial Shipping and Indian Navy, (iii port Authorities, (iii) Fisheries Officials, ilvi Officials of the central and State Governments, (vi Special warnees who are registered with IMD (Album page warneesi, ivii commercial Aviation, (vii) Special interest Groups and (viii) General Pubiic.
Preparation of Forecasts
The important components of cyclone warnings are (a) the forecast of the future path, (b) intensity and (C) the associated destructive weather such as strong winds, heavy rainfall and associated storm surge For forecasting the path of cyclone and storm surges, advanced computer technology in addition to conventional techniques have contributed in relatively efficient and alienate results. For forecasting, intensity of disasters, satellite imageries and remote sensing techniques are more appropriate
inspite of advancement in usage of sophisticated equipments errors of prediction of the path of the cyclones for 24,48 and 72 hours have been ranging to an extent of 220 knls, 430 kms and 730 kms, respectively, in India, these errors have ranged to 150 kms for 24 hour prior forecasts Hence, authenticity of the prediction of path of the cyclone Is normally considered only In case of 24 hours prior forecasts. Greater landfall errors due to earlier warnings require massive evacuation from larger areas, which sometimes are very impractical and uneconomical. Therefore, cycione warnings are not issued earlier than 24 hours all over the world. It is, therefore, important that taskforce of Government is well prepared for emerging situation of evacuation, safety and relief from the weather impacts Of cyclones, witnin 24 nours of occurrence of cyclones..
However, the forecasting techniques and equipment In 1110 is equally sophisticated to any other in the world.
TWO- Stage Warning System
The cyclone warnings are provided in two stages. In the first stage, a tyclone Alert’ is issued 48 hr before the commencement of adverse weather along the coast. In the 2nd stage, a ‘cyclone warning” is issued 24 hour before tne anticipated landfaii. The ports ano fisneries warnings start much earlier. Ports are warned day and night with specially designed Port warning Signals. Informatory messages on cyclones are issued for broadcast to AIR as soon as a tropical cyclone is detected in the Bay of Bengal or in the Arabian sea.
Dissemination of Cyclone Warnings
cyclone warnings are disseminated by the following means: (ii Telegrams with the highest priorIty, (iii Telecast through Doordarshan, liii) Broadcast through AIR, iivi Bulletins to tile Press, WI Broadcast tnrougn P&T’s coastal radio stations for shios in the high seas and coastal areas and through INSAT based Disaster warning Systems
1DWS)
wherever such facilities exist with the recipient. The warning bulletins are issued normally at 3 —hourly intervals, but more frequently when needed. Areas threatened by cyclone, heavy rainfall, magnitude of destructive winds and their impact, storm surge elevation and coastal areas likely to be inundated are some of the elements included in the cyclone warning bulletins, on receipt of warnings, the government official and other authorities take appropriate measures to safeguard the life and property of coastai population, which includes evacuation of people from vulnerable areas to safer places.
Disaster Warning Systems (DWS)
Department of Telecommunication (DOT) telecommuni cation systems such as telegrams, telex and telephones are often among the first casualty during a cyclone situation and warning messages get delayed. To overcome this difficulty, a very dependable and unique communication system known as Disasterwarning System iowsi has been developed in India. Through this system, rapid and direct dissemination of cyclone warnings are made through INSAT satellite to designated addresses at isolated places in local languages. Schematically this is shown in figure here below.
Presently, the disaster warning system is working along east and west coast of all maritime states where 250 DWS sets have been installed in small administrative units like Block Development Taluq Offices and Police Stations. Disaster warning sets are also located in the state and district level government headquarters in the above areas. The ows has been successfully operated on occasions of cyclone during the past and has been found very effective.
Public Awareness Activities in Cyclone Disaster
Prevention and Preparedness
Finally the success of a good cyclone warning system depends on community reaction to the warnings. Individual response to the warnings depends on many factors, such as educational background, cultural background, age, family situation, ownership of assets and previous experience of similar hazardous conditions A good community preparedness committee can, however,
the advanced cyclone warning system
In the world. Due to reliable cyclone warnings and adequate timely steps taken by th~ concerned State and Central Government authorities as well as affected public in general, the loss (specially the human lives) due to tropical cyclones has reduced
Pfeseflt wind measuring instruments available aionq the coast are not capable Of recording hioh wFnd weed generally associated with tropical cyclones, AS SuCh, prs~nc e(Fart of instaatlon of very high Wind speed recorder tiad to be Str8ngthened~ Measurement of storm surges .s another gap area, which needs attention, At present 16 and 72 hour forecast errors of cyclone’s position even Dy most advanced tectrnlques, are quite large ThIs is nowever a problem comrrion to all the nations eFfected by tropical cyclones ana there Is aireaclya very concerted and coordInated efforts continuing throughout tne globe to reduce the forecast errors
significantly during recent times.
pLan and c&r~ out an intenswe educational pro~rarn to ensure that all neopie JiWcQ li~ tydcflE Drone are~5 knciw what to io and how to take protective measures In the case of atnreat from a tropicalcyciorte Permanentcyclcne Preparedness CommIttees (CPC can aPse oreoare model cyclone plans rndlC.attrtg the rIsk areas and suggesting Ouilthn Codes and Strut Wili designs for cycrone shelters For sucn area Scich tornmlttees can also advise on co.P-PstriJction of embankmerits and dykes in vurnerable areas and Creation of coast~i Forestry Iwith specific varIeties Of busfly pFantsj Ifl the rl~k tones to seFw as wrndb~ea1cers
iMO, aiortq wrth tile state governments, evolved a weli orchestrated Information dissemination campaign to enhance giuoilc awareness among Govern merit oFflcla~, voluntary organ isations anti tl~e communIty ~t targe througn sem~nan, worKshoos, noputac talks. publlc]ty rnaterlars etc In Indian languages on characteristics of cyclone hazard, and benefits OF preDaredness and mitigation measures.
Every year to reyFew ti-ie performance of CyC4 one WarnIng patem a Cyclone Review Committee meets in one of the Cyclone WarnIng Centers bY fcutjon, to discuss all the aspects *1 cyclone warning Including its failure and rectFfIc~tIon meawres needed itt tne lutL.lre, These meetings are Chaired by the Director derteral Of Meteorology anti are attended by au the senior officers concerned With the cycinne warrrFrlo worb A~ a paft of pre cyclone exercises pit cyclone c&culars are Sent to ai~ concerned central anti state Government officials before the pre monsoon and post monsoon cyc 1ane season
Keeping pace with the development of
science and technology the cyclone
warning system in India has been
modernised and today, it Is one among
Dnwa For the Fubse I~ovemert
Tror~tcal cyclones mend most of their lire period over the ocean From wnere wind observations are difflti.ilt on the otner hand wInd observations from the cyrione fISd over the ocean by direct measurements or trirough remote
sensing are important in ctec]ding the cyclone’s intensity
as weii as Identifying the oceasMc areas under hIQh wino speed. Such information 15 alsO recluired For provldirtg inltIai Input to track and surge forecasting models, The Shiifl carryrng meteorological Instruments passing
through the cyclone Field t~fl measure surface winds 0½/er
the ocean, Actu~i measurements Of meteorctiogtcal
para meters at different rpelgi,ts over the oceans can also be obtaIned by probing cyclones with me heip of specially
lnstrurnerpted alrcflfts known asCycbne RewnnaicsarPce Alrua+t, F-Iow(ner With the Impro~jement of cyclone warnings the shins started avoiding tne areas affected by tropiC]PC\rdone~ Assucri, presently, Ship obsenratiorts f-ram the Inner core reglorrs oF cyclone are generally not arailsbI& Oue tO high operat~oaai costs the Fjcflit~e~ for cyclone probing I~t reconnaiss~snce aircraft are only avaliable WIth the United States, ocean buoys Lanchored or criftingi are other sources of wind obsentation from die ocean, whose numbers Qv~r the Indian seas are Ensign Want AS such, tfrect wind Observations from the cyclone field are generaky riot available tor the IndIan seas
Si.irface winos over toe ocean ~n 3150 oe ewrnatea Wirn the tiew of remote sensing techniQues USJPO Dorroier radar and sateiiltes with scatterorneter c~n boar4. India Meteoroio’glcal Denartment nas a plan to rejflace the presentcoR network DV Doppler radarina oliaseci manner (first phase starting veiysvonl Ocean SAT currently rnorbut Is carrying the scatterometeron board. it isexoectec that
soon surface wind Observatlorms over the ocean through tnis Enstruriertt would be made available to the meteorological community, Tflesn efforts will finally reduce the gap of rton-avallabiirty 01’ Wind Jiflos-ination from Cht Cyclone field over the ocean Considerably.