I'm having a rare "where am I living?" moment. It'll pass. On Sunday, it was 20 below; one week later, the atmosphere could be warm enough for heavy rain. Bizarre weather swings.
In spite of a string of 30s this week, Minnesota will experience its first white Christmas in three years. Odds favor the snowiest winter in three years as arctic air regularly seeps south. No El Niño to save us this year.
The "polar vortex" is a counterclockwise-spinning gyre of high-altitude winds howling around a mass of cold, low pressure over the arctic. A stronger vortex means high winds are bottling the coldest air to our north. A weaker vortex? More frequent intrusions of subzero air.
We enjoy a two-three week break from face-peeling cold; into at least the first week of January or so. I see flurries Wednesday; models hinting at a real storm Christmas Day. But enough warm air may wrap into the circulation for snow, ice, even an extended period of heavy rain. Guidance predicts 51 and heavy rain on Christmas Day. That's OK. I hear Santa has rain-deer.
