Implementation of CAP in Hong Kong Observatory

TONG Yu-faiScientific Officer

Hong Kong Observatory Hong Kong, China

Common Alerting Protocol (CAP) Implementation WorkshopWMO Headquarters, Geneva, Switzerland, 23 – 24 April 2013

Presentation Outline

• Weather Warnings Service in Hong Kong• Delivery of Warning Warnings in XML Format• CAP Implementation for Local Warnings• CAP Implementation for TC Warnings for

Shipping• Next Steps

Hong Kong Observatory (HKO)

• A government department of Hong Kong• Responsible for forecasting weather and issuing

warnings on weather-related hazards in HK• Monitor and assess radiation levels in HK, and

provide geophysical services

Weather Warnings in Hong Kong

Very Hot Weather WarningVery Hot Weather Warning

Cold Weather WarningCold Weather Warning

Strong Monsoon SignalStrong Monsoon Signal

Fire Danger WarningFire Danger Warning

Frost WarningFrost Warning

Landslip warningLandslip warning

Special Announcement on Special Announcement on FloodingFlooding

Thunderstorm Thunderstorm WarningWarning

Rainstorm Warning Rainstorm Warning Signals Signals

(colour-coded)(colour-coded)

Tropical Cyclone Tropical Cyclone Warning Signals Warning Signals (number-coded)(number-coded)

Hong Kong Observatory (HKO) is the alerting authority in Hong Kong to issue the following weather warnings:

Mass media (newspaper, radio and television) SMS

Telephone enquiry system

Internet Websitehttp://www.weather.gov.hkhttp://www.hko.gov.hk

Public

Mobile applications

eXtensible Markup Language (XML)

Social NetworkTwitter/Weibo

Delivery via diverse and multiple means to communicate weather information

of different volumes and degrees of details

Dissemination of Weather Warnings

Delivery of Warning Messages in XML format

• Currently, HKO disseminates weather warning messages in its own XML-based format to users with the needs of system automation, facilitating exchange of weather warnings between machines.

• Common Alerting Protocol (CAP) is a XML-based data format for exchanging warning messages.

Why do HKO need to deliver weather warnings in CAP - another XML-based format?

Presentation Outline

• Weather Warnings Service in Hong Kong• Delivery of Warning Warnings in XML Format• CAP Implementation for Local Warnings• CAP Implementation for TC Warnings for

Shipping• Next Steps

HKO’s XML data service

• Provision of weather bulletins (including warnings ) in XML since 2003

• A website was set up to allow users to retrieve the XML bulletins over the Internet

• Wide spectrum of users• Effective means to deliver up-to-the-minute weather

reports/forecasts and warning electronically

Weather Info in XML

Media Transport operators

Utilities

Telecom

Service Industry

Government users

HKO’s XML data service

Limitations of the HKO’s XML Service for Delivery of Weather Warnings

“Proprietary” XML Schema• The schema specifying the HKO’s XML bulletins is

proprietary, not adopted from any open data standard• No open library support. Users have to develop their

tools to retrieve the HKO’s XML bulletins and ingest them into their systems.

• Could not contain reference to additional information in the form of a digital asset

• No geographic information. Messages target to all people in HK even though the incident affects only a specific area.

Multiple messages on same incidentFor certain weather warnings, multiple XML bulletins referring to the same incident are issued to users, but containing different aspects of the information about the incident.

Tropical Cyclone Tropical Cyclone Warning SignalWarning Signal

TC bulletin (TC analysis info)

TC signal bulletin (which TC signal is issued?)

TC warning announcement (event description & actions to be taken)

Multiple messages for same event may cause user confusion and incur extra effort on users to incorporate the XML bulletins into their information systems.

Limitations of the HKO’s XML Service for Delivery of Weather Warnings

Presentation Outline

• Weather Warnings Service in Hong Kong• Delivery of Warning Warnings in XML Format• CAP Implementation for Local Warnings• CAP Implementation for TC Warnings for

Shipping• Next Steps

CAP is an XML-based data format for exchanging public warnings. It has advantages over the HKO’s XML data service:

CAP data format

HKO’s XML data format

Open data standard for exchanging public warnings

Geographic information of target area

Reference to additional information (e.g. image/audio files)

Why do HKO need to deliver weather warnings in CAP?

Tropical Cyclone Tropical Cyclone Warning SignalWarning Signal

Implementation of CAP for Local Weather Warnings

TC analysis & forecast track information

TC warning bulletin (which TC signal is issued?)

TC warning announcement (event description & actions to be taken)

These messages are originally coded in 3 different XML bulletins

CAP

Combine them into a signal CAP message

Combine messages of same event into a single CAP message

Example: TC warning signal

Implementation of CAP for Local Weather Warnings

Combine messages of same event into a single CAP message

Example: TC warning signal

TC warning bulletin (which TC signal is issued?)

TC analysis & forecast track information

TC warning announcement (event description & actions to be taken)

<headline>TC No. 3 is issued at XX:XX HKT</headline>

<description>…</description><instruction>…</instruction>

<parameter> [analysis/forecast positions & intensities]</parameter>

CAP message for TC warning

Challenge of Applying CAP for Weather Warnings in HK

CAP element Values allowed by CAP Warnings issued by HKO

Urgency Immediate, Expected, Future, Past, Unknown Either Immediate or Expected

SeverityExtreme, Severe, Moderate, Minor, Unknown

Rainstorms: Amber/Red/BlackTC warning: Number-coded systemFire danger warning: Yellow/Red

CertaintyObserved, Likely, Possible, Unlikely, Unknown

Either Observed or Likely

Certain CAP elements could not be directly determined by HKO’s warning messages

Option 1• Develop rules to assign values of CAP <severity> for

each type of weather warnings.

• As HK people already get used of the number- and colour-coded warning systems, the selection of CAP <severity> values must match their perception on the severity of local weather warnings.

• The warning types (e.g. amber/red/black for rainstorms ) will be coded in the <eventCode> element.

CAP <severity>:CAP <severity>:

Extreme, Severe, Moderate, Minor

??

Rainstorm Warning SignalsRainstorm Warning Signals

30 mm/hr30 mm/hr

50 mm/hr50 mm/hr

70 mm/hr70 mm/hr

Option 2

• Extend the value domain of the CAP <severity> element to include the HKO’s number- & colour-coded warning systems

• However, it would NOT conform to the XML Schema of CAP!

Presentation Outline

• Weather Warnings Service in Hong Kong• Delivery of Warning Warnings in XML Format• CAP Implementation for Local Warnings• CAP Implementation for TC Warnings for

Shipping• Next Steps

Tropical Cyclone Warning for Shipping by Hong Kong Observatory

TC Warning Area of Hong Kong

HK

• Tropical cyclone over the South China Sea could pose a threat to mariners and ships at sea over the region

• HKO issues TC warning to ships when a tropical cyclone is located with the area 10o to 30o N and 105o to 125o E

Target users: mariners/ships over the warning area

Tropical Cyclone Warning for Shippingby Hong Kong Observatory

• Contain information about TC analysis and position/intensity forecast up to 72-hour ahead

• Update every 3 hours• Broadcast to ships via NAVTEX

(a radio frequency broadcast system)

TC Shipping Warning: Event focusing

• TC warning for shipping are focusing on the event, moving from one place to another

• For TC shipping warning, defining an area for sending alert is not as straight-forward as other warnings

T+0

T+24 hrs T+48 hrs

22

Affected Area

Issues need to be rectified in adopting CAP for TC shipping warning• Define what kind of alert to be delivered for the CAP

message of the TC shipping warning.• Decide how to determine the alert area of the CAP

message to better meet the needs of the recipients.• Decide whether and how to break message into individual

CAP alerts for different areas that will be affected at different forecast periods, e.g. 0<T<=24; 24<T<=48, etc.

• Design rules for assigning values to elements urgency, severity and certainty

• Decide on how forecast track could be encoded and in what format

23

Provide alert / notification for the presence of TC of a particular strength

• Break the TC shipping warning into different time intervals, e.g. 0-24, 24-48, 48-72, etc.

• Alert area would be the polygon bounding the initial and final positions of the TC including the uncertainty circles

• Provide alerts for the strongest intensity• Forecast track could be encoded in other XML format, e.g.

CXML, KML, etc. and attach to the CAP in the <resource> element

24

Provide alert / notification for the presence of TC of a particular strength

T+0

T+24 hrs T+48 hrs

Area AArea A

25

CAP (0<T<=24)

Urgency: Immediate

Target Area: A

CAP (0<T<=24)

Urgency: Immediate

Target Area: A

CAP (24<T<=48)

Urgency: Expected

Target Area: B

CAP (24<T<=48)

Urgency: Expected

Target Area: B

Area BArea B

Next Steps …

• Develop rules and automatic system to convert all local warnings & TC advisories into CAP format

• Set up a dedicate website to publish the CAP warnings and feeds

• Develop public outreach and promulgate users (media, public utilities, transport operators, government users, etc) to make use of CAP in their information systems

Thank You

Benefits of Applying CAPfor TC Advisories

• CAP is a standard for delivering alerts and notifications• WMO endorsed standard• Messages could be delivered timely for disaster prevention

and mitigation• CAP supports geographic information. Messages could be

delivered to people who need them, and only those who need them

• In adopting the CAP standard, multiple alert system could be activated with single input

• With a standard, it benefits users because applications, e.g. WMO Severe Weather Information Centre (SWIC), could be developed to meet individual needs.

28

Characteristics of CAP

• Ideal for sending alert / notification of hazards for people at some particular area / location

• Convey messages of urgency, severity and certainty

• Prompt action of recipients (in <instruction> element)

29