On the Significance of Multiple Consecutive Days of Tornado Activity
On the Significance of Multiple Consecutive Days of Tornado Activity
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DOI：
10.1175/mwr-d-13-00347.1
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发表时间：
2014-03
影响因子：
3.2
通讯作者：
R. Trapp
中科院分区：
文献类型：
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作者：
R. Trapp
摘要受近期高端龙卷风事件的时间行为的启发，对美国30年的龙卷风历史记录进行了为期多日的龙卷风活动研究。1983年至2012年期间的3129个龙卷风日是1406个独特的，不重叠的时期。其中只有24%的周期为3天或以上。然而，给定一个爆发日（OB;一个有20个或更多龙卷风报告的日），这种多日期的条件概率为74%，给定一个显著龙卷风日[SIGTOR;一个等级为Fujita/增强Fujita（F/EF）≥ 3]的条件概率为60%。表达这些条件概率的其他方法都导致这样的结论，即SIGTOR和/或OB更有可能包含在龙卷风的多日周期内，而不是1-2天周期内。另外还得到了两个结论：1）SIGTOR和OB在多日周期的后半部分有相对较高的发生可能性，2）多日周期有相对较高的发生可能性。
AbstractMotivated by the temporal behavior of recent high-end tornado events, a 30-yr historical record of tornadoes in the United States is examined for multiple-day periods of tornado activity. Comprising the 3129 tornado days during 1983–2012 are 1406 unique, nonoverlapping periods. Only 24% of these periods have lengths of 3 or more days. However, the conditional probability of such a multiday period given an outbreak day (OB; one with 20 or more tornado reports) is 74%, and given a significant tornado day [SIGTOR; one rated Fujita/enhanced Fujita (F/EF) ≥ 3] is 60%. Alternative ways of expressing these conditional probabilities all lead to the conclusion that SIGTORs and/or OBs are more likely to be contained within multiday periods of tornadoes than within 1–2-day periods. Two additional conclusions are offered: 1) SIGTORs and OBs have a relatively higher likelihood of occurrence during the latter half of the multiday periods, and 2) multiday periods have a relatively higher likelihood of occurrence...