Something like this occurred last winter around the latter part of December if memory serves me correctly. The jet stream retrograded back into Canada from Greenland.

There have been many pollen count studies done across the globe for paleoclimate research. During ice age conditions, its been demonstrated that Northern hemisphere wind patterns at the high and mid latitudes reverse.

As an example, NYC now has a prevailing jet stream pattern from West to East, during times of glaciation, this reverses and generally flows from East to West.

What isn't widely known about ice age climate models is that it isn't solely based on temperature. It's also based on precipitation. For the glaciation process to begin, there must be enough snowfall during each winter season to last through the summer. From what I understand, this begins at the higher elevations with seasonal snowfall rates from 70-100 feet. We're beginning to see an increase in precipitation now.

Another thing about precipitation and global warming. Precipitation [edit]isn't[/edit] solely based on temperature. There must be enough source particles in the atmosphere for water to condense around. In laymen terms, dust. It's somewhat of a mystery at this point where the dust is actually coming from. One theory is that it's coming from space.

[link to science.nasa.gov]

From what I can tell, the Earth is heading into a cooler period. And please take note, most of the ground based temperatures for the past 30 years have been taken from less than ideal circumstances, I.E. cities. Cities are known heat islands and do not reflect the larger regional mean temps. On any summer day, just take a drive from any city to the surrounding rural areas. There is a very drastic temperature difference during day and night hours.

[edit]jeez, I goobed up this post lol, shouldn't write posts upon first waking up.[/edit]