Brandt Maxwell - NOAA Federal 
To: MAP@LISTSERV.ALBANY.EDU 
Reply-To: Brandt Maxwell - NOAA Federal 
Re: Ridiculously high dew point temperatures in the Northeast

Tony (and MAP),

First of all, I agree that Davis stations read higher than ASOS with dew points.  
Seems like in coastal southern California, the Davis sensors will read about 3 deg F higher than the ASOSes 
(harder to say in the mountains and deserts of SoCal where dew points are a lot lower and more variable than at the coast).

Interesting comments about the baseball game.  
Regarding the "thin air" and home runs--how much of that do you think is 
simply due to the temperature versus dew point?  For example, the comparison of 
densities at sea level (and using 1013 mb pressure and a 15 deg C dew point) with temperature:

20 deg C temperature:  1.196 kg/m3
35 deg C temperature:  1.138 kg/m3

Or approximately 6% between a mild day and a hot day.

Compare that with dew point (using a temperature of 35 deg C, 1013 mb pressure) between a "moderate" and "muggy" day:

15 deg C dew point:  1.138 kg/m3
25 deg C dew point:  1.132 kg/m3

Well less than 1% change in density (due to the small partial pressure of water vapor compare to the total air pressure).

Even if you compare a really dry day vs. humid day:

-5 deg C dew point:  1.143 kg/m3
25 deg C dew point:  1.132 kg/m3

It's about 1%, well less than the 6% density difference between "mild" and "hot".

Could it have been more the heat, or is something else in play (ball handling differently due to humidity)?

Of course, the well-known effects of Denver simply having 15% lower density due to the mile-high 
effect are greater than either temperature (unless comparing sub-freezing with hot) or dew point!

Later...
Brandt
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