For the second time in 2008 the weather world returns to Galveston, Texas where this past Wednesday, the city ravaged by Hurricane Ike saw snow.
Photo Credit: Chris Paschenko
As surprising as this occurrence may seem, it was the second time this decade that Galveston has observed snow, and the 14th time since records began in 1871. On average, Galveston gets snow every ten years or so.
As the winter storm system that hit the Gulf Coast raced towards the East Coast, the Northeast was clobbered with ice and snow. Tonight, over one million people in New York, New Hampshire, and Massachusetts are without power.
At this time, almost 32% of the contiguous 48 U.S. states is covered by snow or ice.
Snow Depth Observations - December 12, 2008 (Courtesy NOAA)
Now that the weather outside seems frightful (and freezing), how many of you have delightfully, or sarcastically stated, "It must be global warming!"
Well, you might be right! Arctic temperatures this past fall were again running above normal. This year has continued a warming trend in the Arctic that has been observed since the 1960s.
Surface temperature anomalies in the Arctic from NOAA (1900-2007)
Wait, if the Arctic is warmer, then how did Galveston get snow?
It is important to realize that climate is the average of conditions over a long period of time, not just the conditions at any given moment. At this moment, the Arctic is very cold. How cold? Sixteen locations in Siberia are reporting temperatures lower than -50F. Ever been to Tompo, Russia? It is a 'skin freezes on contact' -66F there right now.
Certainly the words "global warming" and "it's -66F outside" are not synonymous. But, what if I told you that even these bone-freezing temperatures in Siberia are not anywhere near record-breaking? In addition, some of the largest increases in surface temperatures over the past several decades have occurred in Siberia. To put it bluntly, warming a -66F day by a few degrees does not get you a nice day at the beach!
Global warming does not mean that tropical conditions will somehow prevail in the dead of winter. And, just because you experience ice and snow, that doesn't mean global warming is a thing of the past. In fact, many scientists believe that some areas might see more snow and ice events in an era of warmer climate. How can that be? Well, what if a cold, dry 23F day decades ago becomes a 28F day with more moisture in the air this year? In this scenario, the warmer air with more moisture might have a better chance of precipitation, and precipitation in this 28F case would be a snow or ice storm. In other words, the warmer temperatures at certain times of year may contribute to getting more snow and ice!
This weekend, a chunk of this Siberian air is forecast to leave its home, cross the North Pole, then Canada, and pour into much of the U.S. We call this "The Siberian Express." Notice that the air doesn't move around the earth from west to east, but over the top of the North Pole instead! It's a bit like pouring chocolate syrup on the top of an ice cream sundae, and watching the syrup slowly roll off the top.
Snow cover (white) and ice cover (yellow) from Siberia across North Pole to the U.S. Bitter arctic air will follow the red arrow from Siberia to the U.S.
This air mass has the potential to make you think a new ice age is coming. Including the chance of more snow and ice in places where these conditions don't happen often.
But, while you shiver, remember that this air could be colder! So whether you are in Galveston or Siberia, and your snowy front yard makes you smirk "yeah, global warming," pat yourself on the back, you may be right!
If you have any questions about the possibility of frigid temperatures in the U.S. next week, or about how these frigid temperatures and global warming might go hand-in-glove, let us know in the comment space below!
