Thursday, August 19, 2010

It's been a muggy summer

You're not alone if you've thought this summer has been a little extra sticky when compared to previous summers.  So that got me thinking....how have our dew points so far this summer compared to years past?  Remember that we use dew points as a measure of how much moisture we have in the atmosphere - so the higher the value the more humid it will begin to feel.  I had to do a little digging on this one, but spoke with someone from the Midwestern Regional Climate Center down in Champaign, IL.  I'm sure many of us remember the summer of 2009 as a cool and wet one.  As a result, the average dew point was 58.3° (summer being defined as June, July and August).  The average dew point for the summers of 2005 - 2008 ranged anywhere between 60.4° - 60.8° (so 60­°-61°).  So far this summer our average dew point has been 63.7°!   Now, why is that?  We've had a persistent high pressure system in the south that has shifted the jetstream to the north.  This has allowed flooding rains to move through the heartland and gulf moisture to stream into the Midwest.  A much different pattern than what we had last last year.  Hang in there, summer is almost over and soon the ground will be covered with snow! :) 

1 comment:

  1. I had the same question - you were reading my mind! Thanks for pulling together the data that confirms what we've all been feeling....this summer has been more humid than "average".

    On a geeky side note: Dew points (often abbreviated as Td) are a very important weather/climate variable as it has a direct relationship to human comfort. Plus, in the corn belt, humans have a strong influence on summer Td since corn transpires (or sweats if you will) lots of moisture into the atmosphere. (See recent research out of Northern Illinois University for more info about human's influence on Td).
    I think we need more easily accessible Td climatology information and maps, and more effort to educate the public about Td and how it impacts our daily life. Then again, that means we need to have Td measured at more weather stations, which means more funding for weather/climate observations!

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