Graph from the paper
Sudden stratospheric warming (SSW) rate (unit: per year) as a function of zonal wind threshold, U(th), (unit: m/s). The standard threshold is U(th)=0 and a more negative U(th) defines stronger SSW events. Blue points use 61 years (1959-2019) of ERA5 reanalysis data and orange points use 20 years (1996-2015) of data. Black and purple are derived from the seasonal-to-subseasonal forecast dataset using flux-correcting and Markov state modeling, respectively. Credit: Finkel et al. [2023], Figure 2a
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: AGU Advances

Assessing the risk of extreme weather events is crucial for our society, but it is incredibly challenging due to their sporadic nature. Although high-resolution weather models are critical for accurately evaluating extreme events, they are typically run only on synoptic timescales. Therefore, long-term climatological risk assessments rely on centennial-scale integrations of cheaper low-resolution or statistical models.

However, Finkel et al. [2023] propose new statistical methods that utilize subseasonal weather forecast ensembles to extract once-in-500-year events, even with only 20 years of 46-day weather forecasts. The method is specifically applied to sudden stratospheric warming (SSW) events, which provide a source of surface weather predictability on the subseasonal-to-seasonal timescale. As a potential next step, one could seek to understand the impact of global warming on extremes by utilizing a high-resolution model in ensemble forecast mode, initialized around a decade at the end of this century, as provided by a climate model.

Citation: Finkel, J., Gerber, E. P., Abbot, D. S., & Weare, J. (2023). Revealing the statistics of extreme events hidden in short weather forecast data. AGU Advances, 4, e2023AV000881.

—Sarah Kang, Editor, AGU Advances

Text © 2023. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.