Flash Droughts Present a New Challenge for Subseasonal-to-Seasonal Prediction
Flash droughts are a recently recognized type of extreme event distinguished by sudden onset and rapid intensification of drought conditions with severe impacts. They unfold on subseasonal to seasonal (S2S) timescales (weeks to months), presenting a new challenge for the surge of interest in improving S2S prediction. We address what is needed to make progress on understanding, predicting, and preparing for them.
The growing awareness that flash droughts involve particular processes and severe impacts, and likely a climate change dimension, make them a compelling frontier for research, monitoring, and prediction. Most needed are improvements in frequency of products for monitoring and prediction, an objective definition to enable research into potential future changes in flash drought, continued work to understand the processes driving the rapid intensification of drought.
In this perspective, we discuss existing prediction capability for flash droughts and what is needed to establish their predictability. We place them in the context of synoptic to centennial phenomena, consider how they could be incorporated into early warning systems and risk management, and propose two definitions.