Sunday, April 22, 2012

Summer 2012: A Burning Question

People are always asking me if the summer will be hot.  I tell them that this is Columbia, it is always hot.  I often add that the only thing that separates us from hell in the summertime is a screened door.

After this year’s amazingly mild winter, the obvious question is: will this summer be just as amazingly hot?  This is a question that I am already getting from viewers.  Keep in mind that the past two summers have each been record hot summers.  Common sense might say yes, an unusually warm winter will likely be followed by an unusually warm summer — but in this case, common sense would be wrong.

This chart shows the 10 mildest winters ever recorded at Metropolitan Airport, in blue, along with the summers that followed, in red. (This winter doesn’t appear at all, warm as it was, because the summer hasn’t happened yet.) And the answer is… there’s no pattern at all. A winter that’s warmer than average is sometimes followed by a warm summer, but sometimes it’s followed by a pretty average summer, or even an unusually cool one.

Click on the image to see a larger version, but for an interactive version of the graph click here.  Image Credit: Climate Central.
So what is in store for the Midlands this summer?
The Climate Prediction Center (CPC) issued their outlook for the summer last week.  They believe that the odds favor a warmer than normal summer.  However, it is just marginally so.  The greater odds of a hot summer are in the Southwest.

Temperature outlook for June-July-August 2012.  Image Credit: NOAA\CPC.

Much will depend on whether the drought is ongoing and worse.  Droughts and heat waves tend to reinforce themselves making each one worse.  However, a drought would likely mean lower nighttime temperatures than what we have experienced in the past two summers.  It has been the humidity not just the heat that has made them so unbearable.

Here the CPC could not determine a trend.  Their outlook is for equal chances for a wet or dry summer.  Summer is our wettest time of the year, but the trend has been for drier summers over the past 30 years.  The precipitation is typified by afternoon thunderstorms which means that the rain is spotty.  A general rain usually is associated with tropical systems late in the season.

So what is most likely?  I think that this summer will be hotter than normal, but not a record.  That does not mean that we won't see any 100 degree days.  It will likely be dry with a drought in progress at the start of summer.  Beyond that it is unknown.