Seasonal Precipitation Variability and Its Association with Atmospheric Teleconnections in the Fez-Meknes Region, Morocco: NAO, EAP and WeMO

This study investigated seasonal precipitation variability in the economically and agriculturally important Fez-Meknes region and its relationship with major atmospheric circulation patterns, namely the North Atlantic Oscillation (NAO), Western Mediterranean Oscillation (WeMO), and East Atlantic Pattern (EAP), using data from 1961–2019. Results showed strong seasonal associations between precipitation and the three teleconnection indices. The NAO showed the strongest relationships with autumn and winter precipitation, the EAP with spring precipitation and, to a lesser extent, summer precipitation, while the WeMO was primarily associated with autumn rainfall. Correlations were generally negative, indicating that positive phases of these indices tend to reduce precipitation, whereas negative phases favor wetter conditions. During negative NAO phases, autumn precipitation increased by 7–13% and winter precipitation by 34–57%, while positive phases produced decreases of 17–32% and 26–37%, respectively. EAP-related spring precipitation anomalies ranged from −16% to −33% during positive phases and +12% to +24% during negative phases, while WeMO affected autumn rainfall by 9–17%. Wavelet analysis further highlighted the temporal variability of these relationships, revealing significant annual-scale coherence and multiyear periodicities, including approximately 2-, 6–8-, and 12-year bands for NAO-related variability, as well as lower-frequency 7–10-year and >16-year signals for WeMO at selected stations. The results improve understanding of regional precipitation variability and provide useful information for drought assessment and water-resource planning.