These mechanisms can largely explain occurring of abnormal circulation in the stratosphere and troposphere during stratospheric sudden warming and returning then to normal regime.

这些机制可以大致说明一些爆发性增温期间平流层和对流层大气环流出现异常以及随后又恢复到正常冬季环流的过程。

youdao

The cold spell is being caused by a sudden stratospheric warming, forecasters explained.

BBC: Freezing weather forecast for weekend