Because sudden stratospheric warmings typically happen every other year or so, the observational is record is limited. Dynamical models are key for predicting the likelihood of these events. But there are precursors that could be used to build predictive models. In addition to the tropospheric weather patterns mentioned in a previous post (https://www.climate.gov/news-features/blogs/polar-vortex/cooking-strato…), we also look at eddy heat fluxes in the stratosphere and troposphere to show how much wave activity is occurring and where it is coming form.