Trend Analysis of Extreme Precipitation Indices and Climate Oscillations Over the Yucatan Peninsula for the Period 1980–2010

Abstract

Using daily precipitation data from 69 weather stations across the Yucatan Peninsula (YP), we analysed trends in extreme precipitation over 30 years at annual and seasonal scales. The analysis included total precipitation (PRCPTOT), intensity indices (R95p, R99p, SDII and Rx1day), frequency indices (R10mm, R20mm and R30mm), and persistence indices (consecutive dry days [CDD] and consecutive wet days [CWD]). Characterising rainfall distribution is crucial, as southeastern Mexico's YP lacks surface water bodies and relies solely on rainfall to recharge its aquifer. Our findings reveal significant spatial and temporal variability in precipitation across the region. Yucatan and northern Campeche exhibit positive trends in total precipitation and extreme rainfall, while Quintana Roo and southern Campeche show negative trends. Notably, Yucatan experiences more intense rainfall during spring and summer, whereas Quintana Roo shows a marked reduction in winter precipitation. In terms of persistence indices, the CDD index shows a significant positive trend, indicating an extension of dry periods in the region, especially in Quintana Roo. Conversely, the CWD index shows a negative trend, highlighting that rainfall is concentrated over fewer days each year. This study also examines the influence of four climate oscillations on YP rainfall. We found that La Niña particularly affects both winter and summer precipitation. Moreover, the positive phase of the North Atlantic Oscillation (NAO) increases the frequency of intense rainfall events in Yucatan during winter. These results highlight the complexity of regional climate dynamics. Additionally, we analysed intensity–duration–frequency (IDF) curves for three tropical cyclones that impacted the YP in 2020. These events caused flooding, infrastructure damage, and crop losses. Some extreme rainfall associated with these cyclones exceeded the 100-year return period, emphasising the urgent need for adaptive strategies to address changing precipitation patterns and mitigate the worst impacts of such events.