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Publication Date
20 November 2018

Future Changes of Subseasonal Precipitation Variability in North America During Winter Under Global Warming



Changes in subseasonal precipitation variability have important implications for predictability of weather and climate extreme. Here we explore the mechanisms that lead to future changes in subseasonal precipitation variability in North America during winter based on 20 state‐of‐the‐art climate models. Modeling evidences indicate that in a warmer climate, the subseasonal precipitation variability consistently increases over most of North America, with intensified swing between the wet and dry extremes, but declines over Mexico. Using a moisture budget decomposition framework, two opposing mechanisms are established: the thermodynamic component from increasing moisture due to global warming intensifies the subseasonal precipitation variability, while the dynamic component from the projected reduction in subseasonal rainfall‐related circulation variability has an opposite effect. Overall, the thermodynamic effect wins the tug of war at the mid‐to‐high latitudes over most of North America, while the dynamic effect overwhelms the thermodynamic effect in Mexico, creating distinct changes in subseasonal precipitation variability.

“Future Changes Of Subseasonal Precipitation Variability In North America During Winter Under Global Warming”. 2018. Geophysical Research Letters 45: 12,467-12,476. doi:10.1029/2018gl079900.
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