Sunshine to Shivers: The Characteristics and Evolution of Wintertime Temperature Whiplash in the Southern Plains

Rapid extreme temperature swings, termed “temperature whiplashes'', can cause significant socioeconomic impacts on energy, agriculture, and transportation. Few studies have considered temperature whiplashes, however most consider global, continental, or other large domains. These analyses suggest that certain locations within the domain may experience greater temperature swings, one being the United States Southern Plains. By honing in on a specific area and considering temperature whiplashes on a regional scale, more skillful, long-lead prediction and mitigation of these events may be improved. This study focuses on characterizing temperature whiplash events in the Southern Plains region of the United States, specifically during the winter months (December-February). Two types of temperature whiplash events are considered: swings from anomalously warm temperatures to anomalously cold temperatures and vice versa. Using the ERA-5 dataset from 1950-2023, the Temperature Swing Index, defined as the standard deviation of the 24-hour difference filtered 6-hourly 2-meter temperature, is calculated and area-averaged across the Southern Plains. Days where the Temperature Swing Index exceeds the 90th percentile are termed “high swing days” (HSD). Temperature whiplash events are selected by examining each HSD, and considering the longevity and persistence of the overall temperature trend and the signs of the temperature anomalies up to 4 days before and after the HSD. This definition yields 45 anomalously warm to cold whiplash events and 14 anomalously cold to warm whiplash events from 1950-2023. Composites of the geopotential height field at multiple pressure levels and lags illustrate large-scale atmospheric evolutions and key features that could enhance long range predictability. Additionally, links to modes of climate variability like the Madden-Julian Oscillation, the El-Niño Southern Oscillation, and the Pacific/North American pattern are evaluated to determine if there is an increase in frequency or intensity of temperature whiplashes during different phases of these patterns. By establishing the characteristics of temperature whiplash events, their precursors, and connections to climate modes, there is the opportunity to improve predictability of these extreme events and determine how they may change in a changing climate.