If it had been know, the first sign of doom was the change in the weather that had started in the first half of November. Temperatures had started a rapid and steady downward trend all across the northern hemisphere, no matter how the weather service protested about Global Warming. 

Then the snow started, first in the far north, but spread with an uncanny rapidity until all areas north of the equator were having snow. The United States was quickly blanketed with it, and still it came down. Energy prices went up and up, until the federal government stepped in and declared a national emergency.

The sightings started. Reports started trickling in of people seeing the snow swirl into a feminine shape and solidify. They were dismissed as hallucinations caused by the cold and continual cloud cover, until the changing of people started. A panicked survivor told of a group of these Snow Ladies converging on the small town the survivor was from. They had started embracing the people of the town, changing any they embraced, young or old, male or female, well or infirm, into beings like themselves who then changed others yet.

Once enough towns had succumbed to the wintry metamorphosis, Homeland Security was mobilized, and troops recalled from overseas, but to no avail. When the armed forces tried to fire on the Snow Ladies, they just laughingly swirled back into loose snow, and then coalesced into solidity behind the troops and started embracing soldiers.

Reports started coming in on news feeds from other northern hemisphere countries of the same thing happening. But, then the news fell silent. In what seemed like a short time, it was all over. All who had lived north of the equator were now Snow Ladies.

And then, the summer temperatures south of the equator started to cool unusually fast...