Stop saying that the airport is at the same elevation or at different 
elevation from you. That is extraneous and irrelevant information.

Use this sight to find out your elevation:
https://www.freemaptools.com/elevation-finder.htm

If you don't have the latest firmware then you may not have Loop2 data. Not 
having Loop2 data will inhibit greater Altimeter calculation by WeeWX 
because station pressure will be missing and it will have to work backwards 
and that is less accurate. Better to send the software station pressure 
which is done by having Loop2 data.

Do not attempt to constantly calibrate your station with the airport. It is 
perfectly normal for there to be times when your pressure and the airport 
are experiencing different pressures, meaning you'd both be right by each 
showing what is occurring at each location. If you want to know why then 
study isobars. I wrote this little piece which might introduce the subject, 
but I think you should read more about it to fully grasp the concepts.
https://www.wxforum.net/index.php?topic=36579.0

There are also other reasons than isobars when the pressure could be 
different between your location and the airport and that has to do with 
differences in equipment and how pressure is calculated internally by the 
hardware. Different times of the year when the average temperature is at 
extremes will also cause for more discrepancies. Therefore the best time to 
calibrate your barometer is when:


   - when the METAR indicates the pressure is very near 1013.25 hPa
   - at the top of the hour when METAR data is most current
   - when the pressure is steady
   - when it is midday
   - when it is good weather
   - when the temperature *outside* is close to 15°C (least critical)



On Monday, January 11, 2021 at 6:29:12 PM UTC-5 [email protected] wrote:

> * On 2021 11 Jan 16:09 -0600, Tom Keffer wrote:
> > If you're concerned about the distance to the airport, you can take your
> > console to the airport --- it's battery powered.
>
> Well, that seems like a novel idea! :-)
>
> Wouldn't doing so take a few hours? The Davis literature appears to
> suggest so.
>
> > In addition to my Vantage, I have a precision barometer that I use for
> > sailing (±0.25 hPa precision). I've calibrated it against the Portland
> > airport, which is very close to sea level, then brought it home, and
> > calibrated my Davis consoles.
>
> My guess is that's not cheap. Funny how these rabbit holes seem to
> swallow excess cash!
>
> > The onboard barometer of an iPhone is also surprisingly accurate. Use
> > the Starpath
> > app <https://www.starpath.com/marinebarometer/about.htm> to calibrate it
> > near an airport, then bring it home.
>
> No iPhone, but I have a couple of Android 10 phones.
>
> > There are lots of approaches. Best to do all of the above, then
> > triangulate the results.
>
> Interesting thoughts, Tom.
>
> - Nate
>
> -- 
>
> "The optimist proclaims that we live in the best of all
> possible worlds. The pessimist fears this is true."
>
> Web: https://www.n0nb.us
> Projects: https://github.com/N0NB
> GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819
>
>

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