Choosing a Universal Mean Wind for Supercell Motion Prediction
Choosing a Universal Mean Wind for Supercell Motion Prediction
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为 Supercell 运动预测选择通用平均风
DOI：
10.15191/nwajom.2014.0211
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发表时间：
2014
影响因子：
3.1
通讯作者：
J. Garner
中科院分区：
文献类型：
--
作者：
Matthew J. Bunkers;D. A. Barber;Richard L. Thompson;R. edwards;J. Garner
0-6公里AGL平均风已广泛用于预测超级单体运动。然而，当超级单体处于低顶或高位时，使用默认的平均风（其本身可能是基于高度的或压力加权的）可能很难预测其运动。该信息表明单个固定层不适合某些情况，因此本文探讨了各种平均风参数。收集了 583 个观测到的和 829 个快速更新周期超级单体探测的数据集。当使用有效流入层的压力加权作为基础、最不稳定平衡高度的 65% 作为顶部来计算平均风时，结果是对于低顶和升高的超级单元可以获得更好的超级单元运动预测。对于所考虑的整个超级单体案例样本，这种平均风修正的代价是平均绝对误差仅略有增加。
The 06-km AGL mean wind has been used widely in operations to predict supercell motion. However, when a supercell is low-topped or elevated, its motion may be poorly predicted with this default mean wind— which itself could be height-based or pressure-weighted. This information suggests that a single, fixed layer is inappropriate for some situations, and thus various mean-wind parameters are explored herein. A dataset of 583 observed and 829 Rapid Update Cycle supercell soundings was assembled. When the mean wind is computed using pressure weighting for an effective inflow-layer as the base, and 65% of the most-unstable equilibrium level height as the top, the result is that better supercell motion predictions can be obtained for low-topped and elevated supercells. Such a mean-wind modification would come at the cost of only a minor increase in mean absolute error for the entire sample of supercell cases considered.