Signals of Sustained, Cold Pattern with Some Below-Zero Lows In Latter JanuaryJanuary 11th, 2013 at 2:30 pm by Chad Evans under Chad's WLFI Weather Blog
Substantial stratospheric warming is a signal of a weakening polar vortex. This will allow the free flow of cold waves to penetrate the central United States over the next few weeks. Strong polar vortex (like last year with very little stratospheric warming) keep the cold locked up in Canada & near the Arctic Circle. Much of latter January looks quite cold with several mornings below zero.
The warming signature usually coincides with the cold wave unleashed in 1-2 weeks.
Alaska has been very, very cold this winter, but will have warmer weather with some upper ridging taking over during the next 1-2 weeks.
This will also point to more snowfall.