Evaluating South African Weather Service information on Idai tropical cyclone and KwaZulu-Natal flood events

Severe weather events associated with strong winds and flooding can cause fatalities, injuries and damage to property. Detailed and accurate weather forecasts that are issued and communicated timeously, and actioned upon, can reduce the impact of these events. The responsibility to provide such forecasts usually lies with government departments or state-owned entities; in South Africa that responsibility lies with the South African Weather Service (SAWS). SAWS is also a regional specialised meteorological centre and therefore provides weather information to meteorological services within the Southern African Development Community (SADC). We evaluated SAWS weather information using near real-time observations and models on the nowcasting to short-range forecasting timescales during two extreme events. These are the Idai tropical cyclone in March 2019 which impacted Mozambique, Zimbabwe and Malawi resulting in over 1000 deaths, and the floods over the KwaZulu-Natal (KZN) province in April 2019 that caused over 70 deaths. Our results show that weather models gave an indication of these systems in advance, with warnings issued at least 2 days in advance in the case of Idai and 1 day in advance for the KZN floods. Nowcasting systems were also in place for detailed warnings to be provided as events progressed. Shortcomings in model simulations were shown, in particular on locating the KZN flood event properly and over/-underestimation of the event. The impacts experienced during the two events indicate that more needs to be done to increase weather awareness, and build disaster risk management systems, including disaster preparedness and risk reduction.Significance: This paper is relevant for all South Africans and the SADC region at large because it provides information on: the weather forecasting processes followed at the South African Weather Service, available early warning products in South Africa and for the SADC region made possible through the public purse, the performance of nowcasting and modelling systems in the case of predicting two extreme weather events that had adverse impacts on southern African society, and the dissemination of warnings of future extreme weather events

Using remarkability to define coastal flooding thresholds.

Coastal flooding is increasingly common in many areas. However, the degree of inundation and associated disruption depend on local topography as well as the distribution of people, infrastructure and economic activity along the coast. Local measures of flooding that are comparable over large areas are difficult to obtain. Here we use the remarkability of flood events, measured by flood-related posts on social media, to estimate county-specific flood thresholds for shoreline counties along the east coast of the United States. While thresholds in most counties are statistically-indistinguishable from minor flood thresholds of nearby tide gauges, we find evidence that several areas experience noticeable flooding at tide heights lower than existing flood thresholds. These 22 counties include several major cities such as Miami, New York, and Boston, with a total population over 13 million. Our analysis implies that large populations might currently be exposed to nuisance flooding not identified via standard measures

Recommender Thermometer for Measuring the Preparedness for Flood Resilience Management

A range of various thermometers and similar scales are employed in different human and resilience management activities: Distress Thermometer, Panic Thermometer, Fear Thermometer, fire danger rating, hurricane scales, earthquake scales (Richter Magnitude Scale, Mercalli Scale), Anxiety Thermometer, Help Thermometer, Problem Thermometer, Emotion Thermometer, Depression Thermometer, the Torino scale (assessing asteroid/comet impact prediction), Excessive Heat Watch, etc. Extensive financing of the preparedness for flood resilience management with overheated full-scale resilience management might be compared to someone ill running a fever of 41°C. As the financial crisis hits and resilience management financing cools down it reminds a sick person whose body temperature is too low. The degree indicated by the Recommender Thermometer for Measuring the Preparedness for Flood Resilience Management with a scale between Tmin=34,0° and Tmax=42,0° shows either cool or overheated preparedness for flood resilience management. The formalized presentation of this research shows how changes in the micro, meso and macro environment of resilience management and the extent to which the goals pursued by various interested parties are met cause corresponding changes in the “temperature” of the preparedness for resilience management. Global innovative aspects of the Recommender Thermometer developed by the authors of this paper are, primarily, its capacity to measure the “temperature” of the preparedness for flood resilience management automatically, to compile multiple alternative recommendations (preparedness for floods, including preparing your home for floods, taking precautions against a threat of floods, retrofitting for flood-prone areas, checking your house insurance; preparedness for bushfires, preparedness for cyclones, preparedness for severe storms, preparedness for heat waves, etc.) customised for a specific user, to perform multiple criteria analysis of the recommendations, and to select the ten most rational ones for that user. Across the world, no other system offers these functions yet. The Recommender Thermometer was developed and fine-tuned in the course of the Android (Academic Network for Disaster Resilience to Optimise educational Development) project

Design and evaluation of a community and impact-based site-specific early warning system (SS-EWS): the SS-EWS framework

The recent extreme rainfall events in Spain such as the storm Gloria have highlighted the gaps in emergency communication, particularly the disconnect between the available impact-based early warning systems (IBEWSs) and the steps communities take during emergencies. This paper presents a community-centred framework named ‘site-specific early warning system’ (SS-EWS) to co-design and co-evaluate with communities an IBEWS for vulnerable locations within high-risk areas. The components of the framework guide communities in identifying and evaluating local impacts; establishing impact and advisory tables; deriving impact-based rainfall thresholds and warning levels; and configuring the SS-EWS with radar-based nowcasting and numerical weather prediction (NWP) models. A first implementation and evaluation of the SS-EWS have been done for a public school, two ford crossings and the city of Terrassa, Spain. The SS-EWS shows promising results in triggering location-based or site-specific warnings compatible with the reported impacts and proposing actions to reduce the local risk. Furthermore, the combination of NWP and radar-based nowcasting improved the capacity of the SS-EWS to monitor the evolution of the precipitation and capture highly intense rainfall. The SS-EWS can be a straightforward and cost-efficient complement for regional EWS to increase the preparedness of communities.The study has been carried out mainly in the H2020 project ANYWHERE (H2020-DRS-1-2015-700099). The authors extend their gratitude to the municipality of Terrassa and Vicenta Villar, the Civil Protection of Catalonia, the Consorcio de Compensación de Seguros (CCS) and Josep Maria Gibert for kindly providing data.Peer ReviewedPostprint (published version

Towards the “Perfect” Weather Warning

This book is about making weather warnings more effective in saving lives, property, infrastructure and livelihoods, but the underlying theme of the book is partnership. The book represents the warning process as a pathway linking observations to weather forecasts to hazard forecasts to socio-economic impact forecasts to warning messages to the protective decision, via a set of five bridges that cross the divides between the relevant organisations and areas of expertise. Each bridge represents the communication, translation and interpretation of information as it passes from one area of expertise to another and ultimately to the decision maker, who may be a professional or a member of the public. The authors explore the partnerships upon which each bridge is built, assess the expertise and skills that each partner brings and the challenges of communication between them, and discuss the structures and methods of working that build effective partnerships. The book is ordered according to the “first mile” paradigm in which the decision maker comes first, and then the production chain through the warning and forecast to the observations is considered second. This approach emphasizes the importance of co-design and co-production throughout the warning process. The book is targeted at professionals and trainee professionals with a role in the warning chain, i.e. in weather services, emergency management agencies, disaster risk reduction agencies, risk management sections of infrastructure agencies. This is an open access book

Adaptive management of the climate change problem: bridging the gap between research and public policy

There are important differences between adaptation to normal climate and adaptation to climate change. One scientific community is organized to address extreme probabilities in current distributions, and their disaster potential. Another scientific community addresses the longer-term changes in the climate system. There are important differences between natural hazard (extreme and unpredictable events) and disaster as natural hazard with disastrous economic and social consequences as a matter of enormous concern. Finally, disaster management means a forecast for the real disaster events and after these disasters occurred, a post disaster attitude is necessary to ameliorate the situation and to take measures for rapid recovery. In this paper the author tries to address the description, understanding and prediction of extreme events in the weather system and their impact across a range of natural and socio-economic phenomena. Other goals of the paper are to present the weather and climate characteristics, the statistics of extreme events and to evaluate their impact on economy. Thus one major task of the work is to address the management of natural disasters caused by weather: the management of event forecast, risk assessment for various regions, and disaster management after the event occur. At the intersection between Economics, Management and Science of Weather Processes, this interdisciplinary study will provide the reader with insight and tools to address contemporary climate and weather hazard management problems.weather disasters, natural hazard, human vulnerability, extreme events, statistics and impact, management of event forecast, regional risk assessment, post disaster management

Flood Disaster in Pakistan and its Impact on Agriculture Growth (A Review)

The main aim of this paper is to study the flood disaster in Pakistan and its impact on agriculture growth of Pakistan during the flood period of 2010-2014. Pakistan has during the last five consecutive years of 2010, 2011, 2012, 2013 and 2014 faced floods and flash floods. It has been responsible for damages to crops, seeds, households, food grains, livestock and infrastructure. In September 2014, heavy monsoon rains and floods in the catchment areas of India's eastern rivers of Jhelum, Ravi, Sutlej, and Chenab, resulted in flash floods in Punjab, Gilgit Baltistan and Azad Jammu and Kashmir (AJ&K). Over 1 million acres of cropland and 250,000 farmers were affected, in most cases resulting in the loss of standing food, fodder or cash crops. Keywords: Flood disaster, Agricultural Growth, Monsoon, Socio Economic & Infrastructur

Multidisciplinary studies of the social, economic and political impact resulting from recent advances in satellite meteorology, Volume 5

Studies are presented on mesoscale weather monitoring, analysis, and dissemination of weather forecasts for the Wisconsin area

The FLASH project: using lightning data to better understand and predict flash floods

The FLASH project was implemented from 2006 to 2010 underthe EU FP6 framework. The project focused on using lightning observations to better understand and predict convective storms that result in flash floods. As part of the project 23 case studies of flash floods in the Mediterranean region were examined. For the analysis of these storms lightning data from the ZEUS network were used together with satellite derived rainfall estimates in orderto understand the storm development and electrification. In addition, these case studies were simulated using mesoscale meteorological models to better understand the meteorological and synoptic conditions leading up to these intense storms. As part of this project tools for short term predictions (nowcasts) of intenseconvection across the Mediterranean and Europe, and long term forecasts (a few days) of the likelihood of intense convection were developed. The project also focused on educationaloutreach through our website http://flashproject.orgsupplying real time lightning observations, real time experimental nowcasts, forecasts and educational materials. While flash floods and intense thunderstorms cannot be preventedas the climate changes, long-range regional lightning networks can supply valuable data, in realtime, for warningend-users and stakeholders of imminent intense rainfall and possible flash floods