"Overall, the easterly winds descending into the lower tropical stratosphere is continually favorable for redirecting tropospheric waves anomalously poleward, which increases the odds of interaction with the stratospheric polar vortex and hence increases the chances of a SSW event this winter. (AER)
First sign of sudden warming at 30 mb
The contour interval is 5 °C. The pink and light blue shadings indicate warming and cooling, respectively. The red shading denotes warming for values higher than 25 °C.