Londoners advised to stockpile three days of food as fears grow over polar vortex

“Through the latter part of the winter, following a peak in El Niño, the stratospheric polar vortex (SPV) can become weaker, leading to an increased chance of Sudden Stratospheric Warming (SSW) events unfurling, increasing the potential for cold weather. However, significant as El Niño is, it is important to emphasise that it alone does not determine precise weather patterns and other outcomes remain possible.”