EGU21-7411, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Weather regimes in South East Asia: Sub-seasonal predictability of the regimes and the associated high impact weather  

Paula Gonzalez1,2,3, Emma Howard1,2, Simon Thomas4, Thomas Frame2, Oscar Martinez-Alvarado1, John Methven2, and Steven Woolnough1
Paula Gonzalez et al.
  • 1National Centre for Atmospheric Sciences, University of Reading, Reading, UK
  • 2Department of Meteorology, University of Reading, Reading, UK
  • 3International Research Institute for Climate and Society, Earth Institute, Columbia University, Palisades, NY, USA
  • 4L'Institut de Recherche en Astrophysique et Planétologie, 9 Avenue du Colonel Roche, 31400 Toulouse, France

This work considers the sub-seasonal predictability of two sets of weather regimes for South East Asia: a two-tiered assignment, that first considers large-scale patterns and then assigns synoptic-scale regimes, and a flat classification, which only considers the synoptic scale. In the two-tiered approach, the tier 1 large-scale regimes, which capture ENSO and seasonal variations, are each partitioned into South East Asia regional clusters that capture synoptic variability.   

The sub-seasonal predictability of both the standard and tiered regimes is assessed using UKMO GloSea5 hindcasts and forecasts for lead times of up to 5 weeks. We find that the GloSea5 system presents an accurate representation of the regimes’ climatology and a good level of skill for their assignment. Nonetheless, the predictability depends on the specific regimes and some significant forecast drifts are also identified. Additionally, the predictive skill of high impact precipitation events obtained statistically from the prediction of the regimes is assessed and compared with the probabilistic precipitation forecasts of the GloSea5 ensemble.    

A description of the regime classification methodology and their connections to seasonal and synoptic phenomena will be discussed in a separate presentation, titled “Weather regimes in South East Asia: connections with synoptic phenomena and high impact weather” and presented by Emma Howard. 

How to cite: Gonzalez, P., Howard, E., Thomas, S., Frame, T., Martinez-Alvarado, O., Methven, J., and Woolnough, S.: Weather regimes in South East Asia: Sub-seasonal predictability of the regimes and the associated high impact weather  , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7411,, 2021.