© Crown copyright Met Office Developing and Communicating Warnings Sarah Davies UK Met Office Wednesday 17 th April 2013

© Crown copyright Met Office In this session Using the UK Met Office National Severe Weather Warning Service (NSWWS) as an example Understand what makes a weather warning effective Essential elements of an effective warning Communicating warnings Communicating uncertainty Verifying warnings

© Crown copyright Met Office What makes a weather warning effective Essential Elements Easy to understand Variety of access points Easy to access Change behaviour Help people decide what to do Help Emergency Responders plan Help Emergency Responders respond Effective

© Crown copyright Met Office Criteria for issuing a warning Need to find out what types of weather affect the general public and emergency/disaster responders If it doesn't affect them, do you need a warning? Establish and research which types of weather need a warning and why how much rain has to fall or how strong does the wind need to be to warrant a warning? if thresholds or potential impacts are the best measure for issuing a warning

© Crown copyright Met Office Criteria for issuing a warning Thresholds 20mm/hr 30mm/hr 40mm/hr 10mm/24hr 50mm/24hr 50mph gusts 60 mph gusts 2m tidal surge Impacts Saturated ground/Large puddles Flooding of agricultural land from rainfall/ from river bursting banks/coastal Flooding of road networks from rainfall/ river bursting banks/coastal Flooding of towns/cities from rainfall/ river bursting banks/coastal Trees blown down/boats overturned/ power cables brought down Which is more important?

© Crown copyright Met Office History of NSWWS Great Storm 1987

© Crown copyright Met Office UK Severe weather Severe Gales Heavy Snow Heavy Rain Dense Fog Freezing rain/widespread icy roads Heat wave Exceptionally severe when: Severe gales/storms Very heavy snowfall, blizzards, drifting snow All based on meteorological thresholds

© Crown copyright Met Office National Severe Weather Warning Service Warns community of severe or hazardous weather Widespread disruption of communications Transport difficulties Threat to lives, welfare, property

© Crown copyright Met Office National Severe Weather Warning Service THREE TIERS ADVISORY Issued daily at around11am EARLY WARNING Issued several days in advance of the severe weather (typically 3-5 days) FLASH Issued when the severe weather is imminent (up to 6 hours in advance)

© Crown copyright Met Office Severe/Extreme Severe weather – these events are not unusual and are experienced on a number of occasions throughout the year, but more commonly winter months. They will impact on individual areas, but often not significantly. Extreme weather – these events are unusual and only happen around 3 or 4 times per year. They have a significant impact on infrastructure and may lead to casualties.

© Crown copyright Met Office Early Warnings Issued in advance of the expected severe weather (typically 3-5 days) Assessment of the risk of disruption when it is above 60% Each region is assigned percentage risk of disruption (impact based) Disruption map published on website Allows time for preparations to be made Once issued, updated daily until the event

© Crown copyright Met Office Early Warning on the web 1/2/09

© Crown copyright Met Office Flash Warnings Issued when the severe weather is imminent (target of 2 hours, up to 6 hours in advance) Issued if certain critical meteorological thresholds are likely to be met with an 80% probability Issued on county/local authority basis React to rather than prepare for

© Crown copyright Met Office An evolving process In 2009, we asked our stakeholders about: Usefulness of warnings Timeliness Clarity

© Crown copyright Met Office We worked with partner agencies to develop a risk matrix The alert/warning will provide a combination of The potential impact the weather will have The likelihood of the weather happening NSWWS since 2011

© Crown copyright Met Office Likelihood Allows us to communicate uncertainty In general uncertainty is greater at longer lead times Most alerts at 3 to 4 day lead time will be assigned a low/very low likelihood

© Crown copyright Met Office Generic Impacts

© Crown copyright Met Office Impacts Very LowLowMediumHigh Impact and advice associated with SNOW Small amounts of snow lying on roads and pavements so some slippery road surfaces possible. Traffic may move generally slower than normal. Take extra care when walking, cycling or driving in affected areas. More widespread snow lying on roads and pavements but road networks generally open. Care needed with only localised travel disruption. Problems mostly confined to usual prone areas. Take extra care when walking, cycling or driving in affected areas. Journeys through affected areas may take longer than usual. Widespread snow with a number of road closures, others passable only with care. BE PREPARED for some disruption to road, rail and air transport with difficult driving conditions likely and longer journey times. Widespread deep snow with many roads closed or impassable. Roads likely to become impassable with high risk of drivers becoming stranded. Significant disruption to road, rail and air transport. Risk to personal safety. Expect significant disruption to normal day to day life as a result of transport issues, school closures etc. Avoid making unnecessary journeys. Other impacts specific to rain, wind, ice and fog also listed.

© Crown copyright Met Office Colour of warnings (Impact Matrix) Colour determined by combination of likelihood and impact Matrix below shows a high likelihood of a medium impact event produces an AMBER warning

© Crown copyright Met Office Severe Weather Warnings Colour Codes NO SEVERE WEATHER EXPECTED Keep up to date with latest forecast BE AWARE Remain alert and keep up to date with latest forecast BE PREPARED Remain vigilant, keep up to date with latest forecast and take precautions where possible TAKE ACTION Remain extra vigilant, keep up to date with latest forecast. Follow orders and any advice given by authorities and be prepared for extraordinary measures

© Crown copyright Met Office Interpreting the colours ‘Be Aware’‘Be Aware’ means Remain alert and keep up to date with latest forecast ‘Be prepared’ means Remain vigilant, keep up to date with latest forecast and take precautions where possible ‘Take action’ means Remain extra vigilant, keep up to date with latest forecast. Follow orders and any advice given by authorities and be prepared for extraordinary measures

© Crown copyright Met Office Impacts Important to ascertain which impact column is being used Do not get into habit of dismissing yellow warnings/alerts “it’s only a yellow” Yellow could be a very low likelihood of high impacts

© Crown copyright Met Office Access to warnings All warnings/alerts appear on the Met Office website and Hazard Manager Amber and Red Warnings are sent to Category 1 and 2 responders via a self registration scheme - pdf - plain text SMS Can select up to 3 s, 1 sms, and 1 fax

© Crown copyright Met Office Snow Ice Strong Winds Fog Heavy Rain

© Crown copyright Met Office National Severe Weather Warning Service Sent to ~850 organisations Over 2,500 delivery points, including… Blue Lights (Police, Fire and Ambulance) Central, regional and local government NHS Utilities Media Cascaded through individual organisations

© Crown copyright Met Office Warnings on the web Homepage ticker banner

© Crown copyright Met Office UK Warnings

© Crown copyright Met Office Chief Forecasters Assessment

© Crown copyright Met Office Communicating our forecasts and warnings - UK Met Office website Text and alerts Public Weather Service TV and radio You Tube Twitter Facebook Flickr Blog Mobile Phone / Apps

© Crown copyright Met Office Public Appreciation 90% of the public think Met Office weather warnings are useful

© Crown copyright Met Office Communicating our forecasts and warnings Met Office forecasts are broadcast on: BBC TV BBC National Radio BBC Local Radio BBC websites ITV and other commercial TV networks Commercial Radio Newspapers

© Crown copyright Met Office BBC Weather Centre

© Crown copyright Met Office We have two BBC TV studios

© Crown copyright Met Office Verifying warnings Why do we need to? What do we need to know? How can we develop a severe weather database Example from Met Office/UK How could you do it in your country?

© Crown copyright Met Office Why? What happened? Did we forecast it? At the right time In the right place What were the impacts? Was the warning communicated effectively Improve understanding, better warning next time

© Crown copyright Met Office What do we do? Verification Objective verification Did we issue a warning when a threshold was exceeded? Subjective verification Did the warning give good advice What happened? What were the impacts….

© Crown copyright Met Office Subjective verification Verifying the impacts Media reports Twitter feeds Impacts reported by responders Verifying the usefulness Right place? Right time? Enough lead time? Good advice?

© Crown copyright Met Office On Call Log

© Crown copyright Met Office How do we do it? On call log Verification folder

© Crown copyright Met Office

How do we do it? On call log Verification folder Meetings each month All data kept

© Crown copyright Met Office How could you do it? Things to think about How could you develop a severe weather database? What are your issues? How could you collect severe weather information from remote corners of the country?

© Crown copyright Met Office Recap The National Severe Weather Warning Service uses a combination of LIKELIHOOD and IMPACT to give a single colour Easy to understand Aims to change peoples behaviour Use a variety of methods of communication Verification is important to continually improve Work with stakeholders….

© Crown copyright Met Office Questions?