Last week, the Nino SSTA regions were warmer. Three of the four Nino SSTA regions remain within the La Nina threshold. The Nino34 SSTA is -0.9C which is moderate strength La Nina but slightly warmer than the previous week.

Forecast confidence is increasing for a significant snowstorm in the East later next week. ECM has an incredible amount of snow across the entire northeast quadrant of the U.S. while GFS focuses heavy snow on Virginia. With snow on the ground and following arctic air, the East will be super cold for Christmas Day and for a few days that follow.

The character of the -AO regime is about to change. The high-latitude high-pressure ridge shifts from Greenland to Alaska and gradually an Alaska “ridge bridge” toward Siberia develops. The result is increasing risk of a cross-polar arctic air surge from Siberia into North America in 7-10 days. The pattern described is often referred to as the “Siberian Express” and the Alaska “ridge bridge” phrase became popular after the North America “polar vortex” winter of 2013-14.

The November 2022 northern hemisphere snow cover was tied for 3rd most in the 1966-2022 record. In North America, November 2022 ranked 3rd most snowy on record while Eurasia was 12th most snowy of the past 57 years.