Climate Variability and Drought Analytics in North America

Climate variability across North America encompasses a complex interplay of natural oscillations and anthropogenic warming, leading to shifts in precipitation patterns, soil moisture and extreme events such as droughts and wildfires. Recent advances in observational networks, remote sensing and high-resolution modelling have enabled more detailed characterisation of drought onset, persistence and severity. Studies reveal that multi-year fluctuations in sea surface temperatures and atmospheric circulation patterns exert a dominant influence on the frequency and clustering of droughts, particularly in the western United States and the Colorado River basin. Analytical frameworks now integrate statistical decomposition of climate indices with dynamical prediction systems, yielding skillful forecasts on seasonal to decadal timescales. Coupled with machine-learning approaches and improved process understanding, drought analytics are informing water resource management, agricultural planning and wildfire mitigation. The global significance of these developments lies in their potential to guide adaptation strategies under a warming climate, where even modest improvements in forecast skill can translate into substantial socio-economic benefits.

Research from Nature Portfolio

State-of-the-art decadal prediction systems have demonstrated skill in forecasting water supply for the Colorado River several years in advance by exploiting the long-term memory of ocean conditions. Drift-free coupled models driven by observed sea surface temperature precursors (tropical Pacific cooling, North Pacific warming and Atlantic warming) reproduce historical water deficits and forecast future shortages, offering early indicators for agricultural and wildfire risk. A complementary modelling effort has extended drought and wildfire probability forecasts to lead times of up to 45 months by assimilating three-dimensional ocean data and prescribing external radiative forcings. This approach captures low-frequency variability of precipitation and soil moisture in close agreement with observations. Parallel analyses of atmospheric teleconnections have applied advanced correlation techniques to isolate the intrinsic links between Pacific–North American pattern and East Pacific wave-train variability and winter drought over the western United States, revealing significant multi-year and interdecadal relationships once the influences of major oscillations are removed.

Climate Variability and Drought Analytics in North America publication trend

The graph below shows the total number of articles in climate variability and drought analytics in north america across all publications each year (not limited to Nature Index journals).

Technical terms

Decadal variability: Climate fluctuations on timescales of 10–30 years, often driven by ocean–atmosphere interactions.

Ocean memory: The persistence of sea surface temperature anomalies that influence atmospheric conditions over multiple seasons or years.

Dynamical prediction system: A forecasting framework based on numerical simulation of physical processes in the coupled climate system.

Teleconnection: A linkage between climate anomalies in geographically distant regions mediated by large-scale atmospheric waves.

Sea surface temperature (SST): The temperature of the uppermost layer of the ocean, a key driver of atmospheric circulation and moisture supply.

References

1. Colorado River water supply is predictable on multi-year timescales owing to long-term ocean memory. Communications Earth & Environment (2020).
2. Multi-year predictability of climate, drought, and wildfire in southwestern North America. Scientific Reports (2017).
3. “Intrinsic” correlations and their temporal evolutions between winter-time PNA/EPW and winter drought in the west United States. Scientific Reports (2016).
4. Ocean-forcing of cool season precipitation drives ongoing and future decadal drought in southwestern North America. npj Climate and Atmospheric Science (2023).
5. Imprint of the Atlantic multi-decadal oscillation and Pacific decadal oscillation on southwestern US climate: past, present, and future. Climate Dynamics (2013).
6. California margin temperatures modulate regional circulation and extreme summer precipitation in the desert Southwest. Environmental Research Letters (2023).