Tree Rings and Observations Suggest No Stable Cycles in Sierra Nevada Cool?Season Precipitation

California’s water resources rely heavily on cool-season (November–March) precipitation in the Sierra Nevada. Interannual variability is highly volatile and seasonal forecasting has little to no skill, making management particularly challenging. Over 1902–2020, Nevada totals exhibited significant 2.2- 13–15-year cycles, accounting for approximately 40% of total perhaps signifying potential as tools. However, underlying climate dynamics are not well understood it unclear whether these cycles stable over long term. We use tree rings reconstruct back 1400. The reconstruction skillful, 55%–74% observed capturing 20th-century cycles. Prior 1900, indicates other century-long periods spectral power or bands. does indicate cyclicity extended several decades longer, however, with dominant periodicities ranges 2.1–2.7 3.5–8 years. late 1700s through 1800s highest-amplitude reconstruction, 2.4 5.7–7.4 should serve caution against extrapolating guide future expectations. On hand, observations suggest that interannual a purely white noise process research aim diagnose dynamical drivers this critical natural resource.