Tornado Formation and Intensity Prediction Using Polarimetric Radar Estimates of Updraft Area
Tornado Formation and Intensity Prediction Using Polarimetric Radar Estimates of Updraft Area
复制标题
使用极化雷达估计上升气流区域来预测龙卷风的形成和强度
DOI：
10.1175/waf-d-21-0087.1
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发表时间：
2021
影响因子：
2.9
通讯作者：
Kingfield, Darrel M.
中科院分区：
文献类型：
--
作者：
French, Michael M.;Kingfield, Darrel M.
一个样本的198个超级单体的调查，以确定是否雷达代理的风暴中层上升气流的区域可能是一个熟练的预测即将到来的龙卷风形成和/或龙卷风强度峰值。一种新的算法，一个改进的版本的雷暴风险估计从临近预报发展通过大小排序（TRENDSS）算法被用来估计的面积的增强差分雷达反射率因子（ZDR）列在天气监视雷达-1988多普勒资料，theZDR列面积被用作代理的中层上升气流的面积。比较了154个龙卷风超级单体和44个非龙卷风超级单体的ZDR柱面积，其中包括30个具有EF 1、EF 2和EF 3级龙卷风的超级单体;还分析了8个具有EF 4+龙卷风的超级单体。结果发现：（i）在0-1 km方位角切变峰值时，非龙卷风超级单体的ZDR柱面积始终很小（<20 km 2），而龙卷风的情况下，表现出更大的变化面积;和（ii）在龙卷风发生时，EF 3+龙卷风的情况下有较大的ZDR柱面积比龙卷风的情况下额定EF 1/2。此外，所有8个强龙卷风样本在龙卷风发生时的ZDR柱面积均大于30 km 2。然而，ZDR柱面积与雷达估计的最大龙卷风强度和最大龙卷风路径宽度之间只有弱的正相关关系。计划未来的工作，重点是机制连接上升气流的大小和龙卷风的形成和强度进行了总结和使用的修改后的TRENDSS算法，这是免疫toZDR偏见，从而理想的实时操作使用，强调。
A sample of 198 supercells are investigated to determine if a radar proxy for the area of the storm midlevel updraft may be a skillful predictor of imminent tornado formation and/or peak tornado intensity. A novel algorithm, a modified version of the Thunderstorm Risk Estimation from Nowcasting Development via Size Sorting (TRENDSS) algorithm is used to estimate the area of the enhanced differential radar reflectivity factor (ZDR) column in Weather Surveillance Radar–1988 Doppler data; theZDRcolumn area is used as a proxy for the area of the midlevel updraft. The areas ofZDRcolumns are compared for 154 tornadic supercells and 44 nontornadic supercells, including 30+ supercells with tornadoes rated EF1, EF2, and EF3; 8 supercells with EF4+ tornadoes also are analyzed. It is found that (i) at the time of their peak 0–1-km azimuthal shear, nontornadic supercells have consistently small (<20 km2)ZDRcolumn areas, while tornadic cases exhibit much greater variability in areas; and (ii) at the time of tornadogenesis, EF3+ tornadic cases have largerZDRcolumn areas than tornadic cases rated EF1/2. In addition, all eight violent tornadoes sampled haveZDRcolumn areas > 30 km2at the time of tornadogenesis. However, only weak positive correlation is found betweenZDRcolumn area and both radar-estimated peak tornado intensity and maximum tornado path width. Planned future work that focuses on mechanisms linking updraft size and tornado formation and intensity is summarized and the use of the modified TRENDSS algorithm, which is immune toZDRbias and thus ideal for real-time operational use, is emphasized.