California Winter Precipitation Predictability: Insights From the Anomalous 2015–2016 and 2016–2017 Seasons ...
The unexpected dry 2015–2016 El Niño winter and extremely wet 2016–2017 La Niña winter in California challenged current seasonal prediction systems. Using the Met Office GloSea5 forecast ensemble, we study the precipitation and circulation differences between these seasons and identify processes rel...
Main Authors: | , , , |
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Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Columbia University
2018
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Subjects: | |
Online Access: | https://dx.doi.org/10.7916/d8k08n7b https://academiccommons.columbia.edu/doi/10.7916/D8K08N7B |
Summary: | The unexpected dry 2015–2016 El Niño winter and extremely wet 2016–2017 La Niña winter in California challenged current seasonal prediction systems. Using the Met Office GloSea5 forecast ensemble, we study the precipitation and circulation differences between these seasons and identify processes relevant to California precipitation predictions. The ensemble mean accurately predicts the midlatitude atmospheric circulation differences between these years, indicating that these differences were predictable responses to the strong oceanic forcing differences. The substantial California precipitation differences were poorly predicted with large uncertainty. Notable differences in high-latitude circulation anomalies associated with internal variability distinguish the ensemble members that successfully simulate precipitation from those that do not. Specifically, accurate representation of the Arctic Oscillation phase differences improves the accuracy of simulated precipitation differences but these differences ... |
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