Identifying and interpreting extreme rainfall events using image classification

This study presents the first attempt to identify extreme rainfall events based on surrounding sea-level pressure anomalies, using neural network-based classification. Sensitivity analysis was also performed to identify the spatial importance of sea-level pressure anomalies. Three classification models were generated: the first classifies the patterns between extreme and regular rainfall events in the north west of England, the second classifies the patterns between extreme and regular rainfall events in the south east of England, and the third classifies between the patterns of extreme events in the north west and south east of England. All classifiers obtain accuracies between 60-65%, with precision and recall metrics showing that extreme events are easier to identify than regular event. Finally, a sensitivity analysis is performed to identify the spatial importance of the patterns across the North Atlantic, highlighting for all three classifiers the local anomaly sea-level pressure patterns around the British Isles is key in determining the difference between extreme and regular rainfall events. In contrast the pattern across the mid and western North Atlantic shows no contribution to the overall classifications.