In February 2021, a widespread cold-air outbreak, with two associated winter storm systems, impacted the South-Central United States. After a comprehensive summary of the synoptic setup and a day-by-day analysis of the event, we assess the significance of the storm from a climatological perspective. Concerning winter precipitation, there were isolated instances of record snowfall accumulations. While freezing rain and freezing drizzle both occurred, total freezing precipitation accumulations did not exceed a one-in-50 year event. The duration of the cold was notable — many stations across the region broke records for the highest number of consecutive days below freezing. When analyzing hourly temperature observations, we found that the February 2021 event was the record longest duration of hours below freezing for 12 stations. Nearly 6,000 daily temperature records were broken by this event. We next summarize significant impacts of this event. While we find that this event was extreme, most aspects of this storm were not unprecedented. Even in the context of a warming climate, cold events such as this should be considered when assessing risk and hazard mitigation planning. The magnitude of impacts associated with this event suggests a lack of preparedness that needs to be addressed. We discuss the importance of using climate services in planning for future extreme events. While there are documented benefits to users engaging with climate service providers and integrating climate information into their decision-making, the February 2021 event serves as an example of the failures that can occur when climate services have not been integrated into planning. We recommend the use of climate services when assessing risk and planning for future climate and weather extremes.

2021 年 2 月，一场大范围的冷空气爆发以及两个相关的冬季风暴系统影响了美国中南部。在对天气情况进行全面总结和对事件进行逐日分析后，我们从气候学角度评估了风暴的重要性。关于冬季降水，有个别情况下出现了创纪录的降雪累积。虽然冻雨和冻毛毛雨都发生了，但总的冻降水累积没有超过 50 年一次的事件。寒冷的持续时间值得注意——该地区的许多车站打破了连续低于冰点的最高天数记录。在分析每小时的温度观测时，我们发现 2021 年 2 月的事件是 12 个站点的记录最长的零下小时持续时间。将近6个，该事件打破了000个每日温度记录。接下来，我们总结了这一事件的重大影响。虽然我们发现这次事件非常极端，但这场风暴的大部分方面并非史无前例。即使在气候变暖的背景下，在评估风险和减灾计划时也应考虑此类寒冷事件。与此事件相关的影响程度表明缺乏需要解决的准备工作。我们讨论了在规划未来极端事件中使用气候服务的重要性。虽然与气候服务提供商合作并将气候信息纳入其决策的用户有记录在案的好处，但 2021 年 2 月的事件是未将气候服务纳入规划时可能发生的失败的一个例子。