Evaluating the Effectivenessof

Warning Systems

IWTC-6, Costa Rica

Woo-Jin Lee

Korea Meteorological Administration

Working group 5.1

Mr. Peter J. Bowyer (Canadian Hurricane Centre)

Mr. Wenjie Dong (China Meteorological Administration)

Mr. Charles Guard (US National Weather Service)

Mr. Edwin S.T. Lai (Hong Kong Observatory)

Mr. Woo-Jin Lee (Korea Meteorological Administration) Rapporteur

Mr. Nobutaka Mannoji (Japan Meteorological Agency)

Mr. M Alimullah Miyan (SADMC, Bangladesh)

Ms. Rosa Perez (PAGASA, Philippines)

Mr. T. Prasad (Office Of ADGM, India)

Mr. Alan Sharp (Bureau of Meteorology, Australia)

Mr. J. Weyman (US National Weather Service)

Background(1)Total warning systems were discussed at IWTC-5

(2002)

• Forecast accuracy and reliability; encouraging special effort on landfalling TCs

• Warning dissemination and presentation;

• Warning response, public education, disaster management;

• Internation and regional cooperation.

Background(2)WMO Expert Meeting on Effective Early Warnings of

Tropical Cyclones (Kobe, 17- 18 Jan. 2005)• Improved accuracy and quantification of

uncertainty; • Adequate resources for disaster mitigation;

• Qualified personnel;

• Sufficient attention to non-structural (public awareness, information sharing, etc.) mitigation measures;

• Adequate institutional and infrastructure practices for coordination and capacity-building at national, regional and international levels;

• Adequacy of a national disaster management policy;

• Community consciousness.

Forecasting Techniques(1)• Model guidance on intensity need to be improved• Structure analysis for weak TCs to be harmonized

among neighbouring countries.• Analysis of ET varies from center to center

• Much to be learned for the interaction of TC with other circulation systems such as monsoon, topography, mid-latitude troughs

• Application of consensus (and/or EPS) yet challenging from case to case

• Nowcasting tools to be improved for landfalling cyclones

Forecasting Techniques(2)

Availability of dynamical and statistical tools/ model products, and familiarity of the forecasters on those products

Verification to be extended to consider the continuity among different centers, initial conditions (incl. bogusing), times periods

Predictability of track and intensity for 6-12 hours range before landfalling have to be evaluated

Communication channels have to be maintained among forecasters at neighboring countries to exchange views on formation and transition stage in particular

• Continuity and consistency is no less important attribute for operational center

Warning Presentation(1)Actions to take to protect → DISASTER SCALES

• Saffir-Simpson Hurricane Scale• Saffir-Simpson Tropical Cyclone Scale(STiCKs)

Extended use at Southwest Pacific and south east Indian oceanWeakness with storm surge values

• Australian scale5 categories covering weak storms and severe TCs based on max. gust

wind (3sec)

• BangladeshNumbering of signal confusingMaritime bias

Separate warnings may be used for heavy rain, strong wind, storm surges, etc.

• Philippines scaleBoundary issueInteraction with monsoons and slow moving depression

TYPHOON CATEGORIES TYPHOON CATEGORY 1: MINIMAL TYPHOON.Max Sfc Wind 74-95 mph (64-82 kt)Peak Gusts 95-120 mph (82-105 kt) TYPHOON CATEGORY 2: MODERATE TYPHOON.Max Sfc Wind 96-110 mph (83-95 kt)Peak Gusts 121-139 mph (106-120 kt) TYPHOON CATEGORY 3: STRONG TYPHOON.Max Sfc Wind 111-130 mph (96-113 kt)Peak Gusts 140-167 mph (121-144 kt) TYPHOON CATEGORY 4: DEVASTATING TYPHOON.Max Sfc Wind 131-155 mph (114-135 kt)Peak Gusts 168-197 mph (145-170 kt) TYPHOON CATEGORY 5: CATASTROPHIC TYPHOON.Max Sfc Wind 156-194 mph (136-170 kt)Peak Gusts 198-246 mph (171-216 kt).

THE SCALEFrom slide of Mr. C. Guard

Warning Presentation(2)• Heavy rain

Orographically induced rainfall before landfallInteraction with other circulation systems (convergence

line, upper level troughs, etc.)• Strong wind,

Asymmetry under ET• High waves

Swells in front of moving storm

Conduct a survey on existing disaster scales

Understand the needs and interest of users

Extend probabilistic expressions on other TC parameters

• Uncertainties and probabilistic informationPosition error and gust wind

Typhoon Nida13 to 22 May 2004

Source: RSMC Tokyo-Typhoon Center

Warning Dissemination(1)Multiple and diverse approaches

• Internet is limited to access warnings• Satellite communication efficient,

Robust in adverse weather conditionsCustomized warnings to activate loud sirensRANET(RAdio interNET) digital satellite radio broadcast

• New media, Mobile phonesDigital multimedia broadcasting (DMB), internet portal sitesCable TVs

• Other issuesDoor to door notification is most effective (volunteers in

Bangladesh)Commercial sector could play some role Tourists be accessible

Warning Dissemination(2)

Disseminate warnings through multiple and diverse channels with varieties of high and low technology with backup capabilities to facilitate users to respond to the warnings in a timely manner

Public Awareness(1)• Storm surge

Various mixture of tide, surge, wave runup• Specific details

Rain? Wind? Waves?• Parameters

Position and radius of influenceProbabilistic circles and intensity

• Uncertainty of track and intensity forecastsPosition fixTrack errors particularly under landfalling (sensitivity on

approaching angles to the coast line)• Structure or process dependency

TD, TC, ET? Catrina case……

Public Awareness(2)• Various source of information available

Internet access to various centers on position, track, structures (formation, weakening to tropical depression, ET)

• Public confusedParticularly when storm pass between neighbouring

countries of surrounding oceansOften over warning to reduce risk in case of forecast

failure

• Media interest and criticismReasons behind the discrepancy in case of severe

conditions

Conduct research to find out what people understand and not understand

Public Awareness(3)Accuracy and timeliness is not sufficient – false

alarms, rare occurrence, “It won’t happen here”

• Physical vulnerability at locality counts• Curriculum of primary and secondary school

Guam, 45 hours of instruction

• Outreach program Large investment for small audience (Guam)

• Community based approach (Philippines)• Year round activities, campaignsCooperation required among decision makers,

emergency managers, media, stakeholders at community level

Int’l CooperationThe resource and information is limited in the

developing countries for the warning service

• satellite data (some access through Internet only)

• rain gauge obs station

• EPS products and high resolution model output

Regional Cooperation in application of model output and other forecasting guidance, and enhancement of communication capabilities

SummaryStatistical and dynamical guidance need to be

improved particularly for landfalling TCs, weak TCs, for unusual track behaviors, and for ET cyclones

Increased investment is required in public awareness to reap the full benefit of significant progress made in TC forecasting through very large investment of fund and dedicated efforts of scientists on a worldwide scale

International cooperation need to be strengthened to share the information and analysis tools among the research/ operational centers

Thank You