High wind / High gust

[Rampe]

We had a first some-what-windy day since I got my WH-1080. The wind broke all the records, but one thing left me wondering: High Wind 10,7 m/s, High Gust 10,5 m/s. Shouldn't the High Gust be atleast the same as High Wind?

[steve]

Shouldn't the High Gust be atleast the same as High Wind?

Yes, normally you would expect the high gust to be higher than the high wind. What settings have you got for wind speed: "Calculate 10 minute average" (and if you have that set, have you changed the 10-minute value via the ini file?), and "Use speed for avg calculation"? And did the peak occur at a time Cumulus was running, or was that data downloaded from the logger? A screenshot of your wind graph at the time may also be useful.

[Rampe]

Shouldn't the High Gust be atleast the same as High Wind?

Yes, normally you would expect the high gust to be higher than the high wind. What settings have you got for wind speed: "Calculate 10 minute average" (and if you have that set, have you changed the 10-minute value via the ini file?), and "Use speed for avg calculation"? And did the peak occur at a time Cumulus was running, or was that data downloaded from the logger? A screenshot of your wind graph at the time may also be useful.

Hi Steve,

I have "Calculate 10 minute average" checked in the configuration, setting done from the GUI. "Use speed for avg calculation" is not checked. Cumulus was running at the time, and I was actually monitoring the values live. I have included two screenshots (48h graph and Select-a-graph).

[steve]

It's possible there's a bug in the average speed calculation, I guess. Your average speed line does look a bit high compared to your gust line in Select-A-Graph. I may have introduced a bug when I added the configurable average period, and no-one has noticed it previously. I'll investigate.

[Rampe]

It's possible there's a bug in the average speed calculation, I guess. Your average speed line does look a bit high compared to your gust line in Select-A-Graph. I may have introduced a bug when I added the configurable average period, and no-one has noticed it previously. I'll investigate.

I forgot to mention, that I have windspeed multiplier of 1.13, if that makes a difference. No multiplier for gusts (as suggested in the Wiki).

[steve]

I forgot to mention, that I have windspeed multiplier of 1.13, if that makes a difference. No multiplier for gusts (as suggested in the Wiki).

Oh, right, that explains it then.

[Rampe]

I forgot to mention, that I have windspeed multiplier of 1.13, if that makes a difference. No multiplier for gusts (as suggested in the Wiki).

Oh, right, that explains it then.

I feel slightly embarrassed. Maybe I'll just add the same multiplier to gust

[steve]

I feel slightly embarrassed.

That's OK, I should have asked. I was about to ask, as my investigations were bringing me to the conclusion that the code was OK.

Maybe I'll just add the same multiplier to gust

It does make it all more logical. The recommendation to not apply a multiplier to gusts comes from the UK met office recording rules. But I guess it depends on the reason for the multiplier in the first place; and when you see the situation you've had, it just makes it confusing.