Thursday, January 31, 2013

Did winter storm "Magnus" result from climate change?


Was this weeks “winter super storm” (Magnus) a sign of climate change?  Probably so. Although "cold-core", it was almost like a winter version of another Sandy, almost like a land tropical storm.  

The damage in Georgia sounds horrible.  In northern Virginia, it got warmer Tuesday than it should have, and didn’t drop much below 60 degrees Tuesday night.  Wednesday, it clouded over quickly, but stayed near 70 degrees (away from the river) all day. 

In the spring, that would be all right.  But in the winter, the air in a cold front coming behind is much colder, creating the likelihood of severe storms. 

Even so, as the front approached northern VA Wednesday afternoon, the line in front of it seemed weaker.  Then it stalled, and a line started overrunning it from the south.  Storm lines that train from south to north can sometimes be much more dangerous than lines that simply move from west to east and go away. 

At 6:30 PM, the NWS issued a “tornado watch” for the DC area.  There was no such watch farther south until you got to the Carolinas.  On the WJLA and Weather.com maps, you could see little hooks in the areas of heavy rain.  That means rotation aloft.  At 5000 feet, the wind speeds were said to be 90 mph. 

Fortunately, the rain wasn’t quite heavy enough to bring any of the rotation down to the ground. 

Finally, at 8 PM, the first “line” arrived in north Arlington, VA.  In the areas below the hilltops (the Trinity Presbyterian Church outdoor chapel is on one of the “protective” high points), a bit sheltered, there wasn’t much wind, and the cold rain was moderate, lasting fifteen minutes.  (This often happens.  In northern VA, areas to the south and east of DC seem more vulnerable to the worst storms, as I found out when I lived in Annandale in the 1990s.)  It took the temperature down ten degrees.  The worst should have been over.
  
But then it warmed back up.  A second line formed and came through about midnight.  Again, not too bad right here.  But reports of outages and downed trees were coming in.  Nothing went out right here. 

But with climate change, it seems as tough the storms are getting more complex, with more moisture, stronger winds, and much higher volumes of water.  Areas never exposed to flood could be,  and long tracking tornadoes could occur even in the mid-Atlantic, where so far they have been rare.

I dread to think of this same setup at the end of March, with outdoor temperatures say in the low 80s, high dew points, and a cold front with temperatures just a little warmer than what we had this time.  There could have been catastrophic tornadoes much further north.  I wonder if the March 1993 "Storm of the Century" could have produced tornadoes had it formed farther west (instead of a blizzard).  The "backside" or "thundersnow" of that storm produced one of the highest per-hour snowfall rates ever seen in northern VA.  
     
And it’s difficult to build your own life, if the infrastructure around you is becoming less stable. You become more dependent on others where you accept it or not.  

Here is some video of the Adairsville GA  tornado


I visited nearby Cartersville GA in 1998, to visit Sharon Harris and “Adovcates for Self-Government”   I remember, “two wrongs don’t make a right”. 

Note, below: My Droid "severe alert" (from the severe thunderstorm warning at 7:30 PM) won't go away. 


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