Development of a prototype real-time sting-jet precursor tool for forecasters
Development of a prototype real-time sting-jet precursor tool for forecasters
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为预报员开发实时喷射前兆工具原型
作者：
Gray S
一个原型的实时刺喷前兆工具（表2的审查克拉克和格雷（2018）），并怀疑已经发生在更多。在气旋的卫星图像中可见的独特云特征可以指示刺流，但这种识别只有在气旋处于刺流即将发生或实际发生的阶段时才有可能。在较长的提前期内，气象局预报员主观地考虑对流层上部槽和急流的构型及其导致夏皮罗-凯瑟型气旋生成的可能性（Shapiro and凯瑟，1990），以及考虑刺急流威胁时的高分辨率对流允许模式输出。预报员面临的一个挑战是，业务全球预报模型目前在解决sting喷流的能力方面处于边缘，而CCB和WCB喷流则得到了很好的解决。此外，用于灾害概率预报的集合业务全球预报的较粗分辨率根本不足以代表尾喷流。这限制了预报员在几天的提前时间内预测气旋是否可能发展成刺喷流的能力。在这里，我们描述了一个原型的实时工具，气象局预报员可以用来确定在这些集合预报的刺痛射流发生的有利条件的发展。
A prototype real-time sting-jet precursor tool (table 2 of the review by Clark and Gray (2018)), and are suspected to have occurred in many more. Distinctive cloud features visible in satellite imagery of cyclones can indicate a sting jet, but this identification is only possible once the cyclone is at the stage when sting jets are about to occur or actually occurring. At longer lead times, Met Office forecasters subjectively consider upper-tropospheric trough and jet-stream configurations and their potential to lead to Shapiro–Keyser-type cyclogenesis (Shapiro and Keyser, 1990), as well as high-resolution convection-permitting model output, 1 in considering sting-jet threat. A challenge to forecasters is that operational global forecast models are currently borderline in their ability to resolve sting jets, in contrast to the CCB and WCB jets that are well resolved. Furthermore, the coarser resolution of ensemble operational global forecasts, used for probabilistic forecasts of hazards, is not sufficient to represent sting jets at all. This limits the ability of forecasters to predict, at several days lead time, whether a cyclone is likely to develop a sting jet. Here we describe the development of a prototype real-time tool that Met Office forecasters can use to identify favourable conditions for sting jet occurrence in these ensemble forecasts.