Multi-Decadal Variations of Durations of Extreme Temperatures in the Southeastern United States

The number of extreme temperature occurrences and their durations in the southeast United States varies during three periods: the Warm Regime subset (WRs), the Cold Regime subset (CRs), and the Modern Record (MR). Multidecadal variations in the regional patterns of the counts and durations of summer-day and winter-day extremes reveal that during the MR, the extreme temperature counts and durations in Florida are more consistent with a WRs setup whereas these parameters for the inland states (Alabama, Georgia, North Carolina, and South Carolina) are more consistent with a CRs setup. We also found that during the CRs (WRs), the majority of stations show a statistically significant increase in the likelihood of exactly one winter-day (summer-day) extreme occurrence. During the MR, both inland and coastal stations show a statistically significant increase in the likelihood of exactly one winter-day occurrence. This increased likelihood is not seen during the MR for a summer-day extreme occurrence. Patterns in the behavior of summer-day and winter-day extremes during the CRs and WRs may provide insight about how extreme temperatures will behave in future periods, if the period is forecasted to have similar setups to that of the CRs or WRs. Insight about the duration and counts of extreme temperatures is useful to the agricultural community, power industries, and health officials.