NBIC-ACS Stage 2 Canadian Forest Fire Weather Index - baseline scenario, 5%, 2% and 1% annual exceedance probabilities

The Canadian Forest Fire Weather Index (FWI) is a fire weather potential index that describes how current weather conditions and recent precipitation patterns could support a landscape fire. FWI calculations are based on Van Wagner & Pickett (1985) and Van Wagner (1987), and dependent on air temperature, relative humidity, wind speed and precipitation. The metric was developed with the worst conditions believed possible in Canada corresponding to a value of 200, although in Australia values above 200 are regularly reported. This metric was also originally developed for boreal forests, although was later generalised to different climate and vegetations. Here we provide predicted upper-bound FWI values across the Australian landscape, defined for a set of Annual Exceedance Probabilities. We calculate FWI based on the latest Bureau of Meteorology historical weather reanalysis BARRA-R2, reporting modelled hourly weather conditions from 1979 to current at a spatial resolution of approximately 11 kilometres. More than 400,000 data points at every location are then processed using the National Bushfire Intelligence Capability (NBIC) Extreme Values Analysis to predict extreme daily maximums and their likelihood. FWI is not used routinely in Australia, however it is the reference fire weather metric for other national and international contexts. As such it can play an important role in reporting the evolution of Australian bushfire hazard in international forums. All these characteristics result in datasets that are a significant advancement in defining extreme fire weather, surpassing previous approaches and offering a robust foundation for informed decision-making in managing and mitigating Australia’s growing bushfire risks in a changing climate.\nLineage: The Canadian Forest Fire Weather Index (FWI) - baseline scenario is calculated using the historical weather reanalysis dataset BARRA-R2 by Bureau of Meteorology (https://dx.doi.org/10.25914/90rq-d839). Variables used are near surface air temperature, near surface relative humidity, precipitation and near surface wind speed.\n\nHourly weather variables are sampled or accumulated to 12PM (used as reference hour of the day), then combined using the equations developed by Van Wagner & Pickett. (1985) [1] and Van Wagner (1987) [2]. FWI is calculated for more than 43 years of daily weather data and then processed using extreme values analysis to model the expected FWI values at annual exceedance probabilities.\n\n[1] Van Wagner, C.E.; Pickett, T.L. 1985. Equations and FORTRAN program for the Canadian Forest Fire Weather Index System. Canadian Forestry Service, Petawawa National Forestry Institute, Chalk River, Ontario. Forestry Technical Report 33. 18 p.\n[2] Van Wagner, C.E. 1987. Development and structure of the Canadian Forest Fire Weather Index System. Canadian Forestry Service, Headquarters, Ottawa. Forestry Technical Report 35. 35 p.\n\n\nImportant Disclaimer:\nCSIRO advises that the information contained in this dataset comprises general statements and information based on scientific research. The user is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it.

加拿大森林火险天气指数（Canadian Forest Fire Weather Index, FWI）是一类火险天气潜力指数，用于表征当前气象条件与近期降水格局对林火发生的支撑潜力。FWI的计算基于Van Wagner与Pickett（1985）及Van Wagner（1987）提出的方法，依赖于气温、相对湿度、风速与降水数据。该指数最初以加拿大境内可观测到的极端条件对应数值200为基准，但在澳大利亚，数值超过200的情况时有报道。其研发初衷为适配北方针叶林（boreal forests），后续被推广应用于不同气候与植被类型。
本数据集提供澳大利亚全境的预测上限FWI数值，针对一组年超越概率（Annual Exceedance Probabilities）进行定义。我们基于澳大利亚气象局最新发布的历史气象再分析数据集BARRA-R2计算FWI，该数据集还原了1979年至今的逐小时气象条件，空间分辨率约为11千米。随后，通过国家丛林火灾智能能力（National Bushfire Intelligence Capability, NBIC）极端值分析工具，对每个点位超过40万个数据点进行处理，以预测极端日最大值及其发生概率。
FWI在澳大利亚并未得到常规应用，但却是其他国家及国际语境下的参考火险天气指数。因此，该指数可用于在国际论坛中汇报澳大利亚丛林火灾风险的演变态势。上述特性使得本数据集在定义极端火险天气方面取得了重要进展，超越了此前的研究方法，可为气候变化背景下管理、减缓日益严峻的澳大利亚丛林火灾风险提供稳健的决策依据。
数据集溯源：加拿大森林火险天气指数（FWI）基准情景的计算，采用澳大利亚气象局发布的历史气象再分析数据集BARRA-R2（https://dx.doi.org/10.25914/90rq-d839）。所用变量为近地表气温、近地表相对湿度、降水与近地表风速。
逐小时气象变量会被采样或累加至当日12时（作为当日参考时刻），随后通过Van Wagner与Pickett（1985）[1]及Van Wagner（1987）[2]提出的公式进行整合计算。本数据集针对43年以上的逐日气象数据计算FWI，随后通过极端值分析建模得到不同年超越概率下的预期FWI数值。
[1] Van Wagner, C.E.; Pickett, T.L. 1985. Equations and FORTRAN program for the Canadian Forest Fire Weather Index System. Canadian Forestry Service, Petawawa National Forestry Institute, Chalk River, Ontario. Forestry Technical Report 33. 18 p.
[2] Van Wagner, C.E. 1987. Development and structure of the Canadian Forest Fire Weather Index System. Canadian Forestry Service, Headquarters, Ottawa. Forestry Technical Report 35. 35 p.
重要声明：
澳大利亚联邦科学与工业研究组织（Commonwealth Scientific and Industrial Research Organisation, CSIRO）提示，本数据集所载信息均为基于科学研究的一般性陈述与内容。使用者应知悉，此类信息可能存在不完整性，或无法适配特定应用场景。因此，在未获取事前专业、科学与技术咨询之前，不得依赖该信息或据此采取行动。在法律允许的最大范围内，CSIRO（包括其雇员与顾问）不对任何因直接或间接使用本出版物（全部或部分）及其所载任何信息或材料而产生的任何后果承担责任，包括但不限于所有损失、损害、费用、开支及其他任何形式的赔偿。