Reading about them weather instruments made me think about LoadBase allowing us to use DA = Density Altitude, which according to wikipedia it means:
is the altitude in the International Standard Atmosphere at which the air density would be equal to the actual air density at the place of observation. "Density Altitude" is the pressure altitude adjusted for non-standard temperature.
So, where do we get this number which represents an altitude? One way would be your weather instrument.
My BRUNTON ADC-PRO, will give me or display this elevation for me called Density Altitude.
In the two examples down below, I took atmospheric readings at the same physical elevation, 444', but you'll see that my Brunton gave me DA values of 1308 and 38.8 --> 40.0.
Another way would be to get some atmospheric values, go online, find a Density Altitude calculator, input the values and have it tell you the DA value. Since I'm not going to be doing that, I decided to use the values given to me by my Brunton and run the program twice, with the atmospheric values and with just the DA value and see how close the shooting charts would compare to each other.
The pic on the left shows that for the sightin only the DA value can be used; and the pic at the right shows that if you move to anyother conditions you can only input the value for the new DA. In other words, if you decide to use DA instead of ATM, then you have to do it for both, sight in and field conditions.
Here is the comparing of the two, the ATM values and the DA value obtained from my Brunton ADC-PRO. Now you can decide if using DA is close enough for you. There are two ways to calculate DA there is a short way and a long way. The more precise the DA number is calculated the more precise the numbers on the wind-elevation chart will be.
If your weather station calculates DA, do a similar test to see how accurate the numbers you are getting are. Using the ATM values is where you get the most accuracy, but that SINGLE DA VALUE is right up there!!!