Welcome to the new home of the Cumulus Support forum.

Latest Cumulus release v1.9.4 (build 1099) - Nov 28 2014
Latest Cumulus MX release - v3.0.0 build 3043 Jan 20 2017. See the Wiki for download

Pressure readings CumulusMX and wxnow.txt

Discussion of version 3 of Cumulus, which runs on Windows, Linux, and OS X. All Cumulus MX queries in here, please.
Post Reply
falkunmalti
Posts: 39
Joined: Thu Oct 09, 2014 4:19 pm
Weather Station: Oregon Scientific WMR200
Operating System: Windows 8.1
Location: Ontario, Canada

Pressure readings CumulusMX and wxnow.txt

Post by falkunmalti » Thu Nov 09, 2017 5:23 pm

Hi

I wonder if someone can help. I have noticed a large difference in the pressure readings displayed in the CumulusMX gauges and the number copied into the wxnow.txt. For example right now, the reading on the gauge is 1008, which does agree with the Oregon Scientific Weather display, but the number copied into the wxnow.txt is 1017.5. Is there any reason why the two numbers should differ? The other numbers seem to be ok.

Thanks in advance.

Joe
VA3JLF

User avatar
steve
Cumulus Author
Posts: 26713
Joined: Mon Jun 02, 2008 6:49 pm
Weather Station: None
Operating System: None
Location: Vienne, France
Contact:

Re: Pressure readings CumulusMX and wxnow.txt

Post by steve » Thu Nov 09, 2017 6:06 pm

As noted in the wiki page about the wxnow.txt file, the pressure in wxnow.txt is altimeter pressure rather than MSLP (as that’s the way CWOP want it). Altimeter pressure is calculated from the absolute pressure from your station and your configured altitude.
Steve

falkunmalti
Posts: 39
Joined: Thu Oct 09, 2014 4:19 pm
Weather Station: Oregon Scientific WMR200
Operating System: Windows 8.1
Location: Ontario, Canada

Re: Pressure readings CumulusMX and wxnow.txt

Post by falkunmalti » Thu Nov 09, 2017 10:00 pm

steve wrote:As noted in the wiki page about the wxnow.txt file, the pressure in wxnow.txt is altimeter pressure rather than MSLP (as that’s the way CWOP want it). Altimeter pressure is calculated from the absolute pressure from your station and your configured altitude.
Thanks Steve, I knew there had to be a reason for that.

Post Reply